WorldWideScience

Sample records for amoeboid microglial cells

  1. Transcriptome analysis of amoeboid and ramified microglia isolated from the corpus callosum of rat brain

    Directory of Open Access Journals (Sweden)

    Parakalan Rangarajan

    2012-06-01

    Full Text Available Abstract Background Microglia, the resident immune cells of the central nervous system (CNS, have two distinct phenotypes in the developing brain: amoeboid form, known to be amoeboid microglial cells (AMC and ramified form, known to be ramified microglial cells (RMC. The AMC are characterized by being proliferative, phagocytic and migratory whereas the RMC are quiescent and exhibit a slow turnover rate. The AMC transform into RMC with advancing age, and this transformation is indicative of the gradual shift in the microglial functions. Both AMC and RMC respond to CNS inflammation, and they become hypertrophic when activated by trauma, infection or neurodegenerative stimuli. The molecular mechanisms and functional significance of morphological transformation of microglia during normal development and in disease conditions is not clear. It is hypothesized that AMC and RMC are functionally regulated by a specific set of genes encoding various signaling molecules and transcription factors. Results To address this, we carried out cDNA microarray analysis using lectin-labeled AMC and RMC isolated from frozen tissue sections of the corpus callosum of 5-day and 4-week old rat brain respectively, by laser capture microdissection. The global gene expression profiles of both microglial phenotypes were compared and the differentially expressed genes in AMC and RMC were clustered based on their functional annotations. This genome wide comparative analysis identified genes that are specific to AMC and RMC. Conclusions The novel and specific molecules identified from the trancriptome explains the quiescent state functioning of microglia in its two distinct morphological states.

  2. Interstitial flows promote an amoeboid cell phenotype and motility of breast cancer cells

    Science.gov (United States)

    Tung, Chih-Kuan; Huang, Yu Ling; Zheng, Angela; Wu, Mingming

    2015-03-01

    Lymph nodes, the drainage systems for interstitial flows, are clinically known to be the first metastatic sites of many cancer types including breast and prostate cancers. Here, we demonstrate that breast cancer cell morphology and motility is modulated by interstitial flows in a cell-ECM adhesion dependent manner. The average aspect ratios of the cells are significantly lower (or are more amoeboid like) in the presence of the flow in comparison to the case when the flow is absent. The addition of exogenous adhesion molecules within the extracellular matrix (type I collagen) enhances the overall aspect ratio (or are more mesenchymal like) of the cell population. Using measured cell trajectories, we find that the persistence of the amoeboid cells (aspect ratio less than 2.0) is shorter than that of mesenchymal cells. However, the maximum speed of the amoeboid cells is larger than that of mesenchymal cells. Together these findings provide the novel insight that interstitial flows promote amoeboid cell morphology and motility and highlight the plasticity of tumor cell motility in response to its biophysical environment. Supported by NIH Grant R21CA138366.

  3. Mature and progenitor endothelial cells perform angiogenesis also under protease inhibition: the amoeboid angiogenesis.

    Science.gov (United States)

    Chillà, Anastasia; Margheri, Francesca; Biagioni, Alessio; Del Rosso, Mario; Fibbi, Gabriella; Laurenzana, Anna

    2018-04-03

    Controlling vascular growth is a challenging aim for the inhibition of tumor growth and metastasis. The amoeboid and mesenchymal types of invasiveness are two modes of migration interchangeable in cancer cells: the Rac-dependent mesenchymal migration requires the activity of proteases; the Rho-ROCK-dependent amoeboid motility is protease-independent and has never been described in endothelial cells. A cocktail of physiologic inhibitors (Ph-C) of serine-proteases, metallo-proteases and cysteine-proteases, mimicking the physiological environment that cells encounter during their migration within the angiogenesis sites was used to induce amoeboid style migration of Endothelial colony forming cells (ECFCs) and mature endothelial cells (ECs). To evaluate the mesenchymal-ameboid transition RhoA and Rac1 activation assays were performed along with immunofluorescence analysis of proteins involved in cytoskeleton organization. Cell invasion was studied in Boyden chambers and Matrigel plug assay for the in vivo angiogenesis. In the present study we showed in both ECFCs and ECs, a decrease of activated Rac1 and an increase of activated RhoA upon shifting of cells to the amoeboid conditions. In presence of Ph-C inhibitors both cell lines acquired a round morphology and Matrigel invasion was greatly enhanced with respect to that observed in the absence of protease inhibition. We also observed that the urokinase-plasminogen-activator (uPAR) receptor silencing and uPAR-integrin uncoupling with the M25 peptide abolished both mesenchymal and amoeboid angiogenesis of ECFCs and ECs in vitro and in vivo, indicating a role of the uPAR-integrin-actin axis in the regulation of amoeboid angiogenesis. Furthermore, under amoeboid conditions endothelial cells seem to be indifferent to VEGF stimulation, which induces an amoeboid signaling pattern also in mesenchymal conditions. Here we first provide a data set disclosing that endothelial cells can move and differentiate into vascular

  4. Microglial migration and interactions with dendrimer nanoparticles are altered in the presence of neuroinflammation.

    Science.gov (United States)

    Zhang, Fan; Nance, Elizabeth; Alnasser, Yossef; Kannan, Rangaramanujam; Kannan, Sujatha

    2016-03-22

    Microglial cells have been implicated in neuroinflammation-mediated injury in the brain, including neurodevelopmental disorders such as cerebral palsy (CP) and autism. Pro-inflammatory activation of microglial cells results in the impairment of their neuroprotective functions, leading to an exaggerated, ongoing immune dysregulation that can persist long after the initial insult. We have previously shown that dendrimer-mediated delivery of an anti-inflammatory agent can attenuate inflammation in a rabbit model of maternal inflammation-induced CP and significantly improve the motor phenotype, due to the ability of the dendrimer to selectively localize in activated microglia. To elucidate the interactions between dendrimers and microglia, we created an organotypic whole-hemisphere brain slice culture model from newborn rabbits with and without exposure to inflammation in utero. We then used this model to analyze the dynamics of microglial migration and their interactions with dendrimers in the presence of neuroinflammation. Microglial cells in animals with CP had an amoeboid morphology and impaired cell migration, demonstrated by decreased migration distance and velocity when compared to cells in healthy, age-matched controls. However, this decreased migration was associated with a greater, more rapid dendrimer uptake compared to microglial cells from healthy controls. This study demonstrates that maternal intrauterine inflammation is associated with impaired microglial function and movement in the newborn brain. This microglial impairment may play a role in the development of ongoing brain injury and CP in the offspring. Increased uptake of dendrimers by the "impaired" microglia can be exploited to deliver drugs specifically to these cells and modulate their functions. Host tissue and target cell characteristics are important aspects to be considered in the design and evaluation of targeted dendrimer-based nanotherapeutics for improved and sustained efficacy. This ex

  5. New physical concepts for cell amoeboid motion.

    Science.gov (United States)

    Evans, E

    1993-04-01

    Amoeboid motion of cells is an essential mechanism in the function of many biological organisms (e.g., the regiment of scavenger cells in the immune defense system of animals). This process involves rapid chemical polymerization (with numerous protein constituents) to create a musclelike contractile network that advances the cell over the surface. Significant progress has been made in the biology and biochemistry of motile cells, but the physical dynamics of cell spreading and contraction are not well understood. The reason is that general approaches are formulated from complex mass, momentum, and chemical reaction equations for multiphase-multicomponent flow with the nontrivial difficulty of moving boundaries. However, there are strong clues to the dynamics that allow bold steps to be taken in simplifying the physics of motion. First, amoeboid cells often exhibit exceptional kinematics, i.e., steady advance and retraction of local fixed-shape patterns. Second, recent evidence has shown that cell projections "grow" by polymerization along the advancing boundary of the cell. Together, these characteristics represent a local growth process pinned to the interfacial contour of a contractile network. As such, the moving boundary becomes tractable, but subtle features of the motion lead to specific requirements for the chemical nature of the boundary polymerization process. To demonstrate these features, simple examples for limiting conditions of substrate interaction (i.e., "strong" and "weak" adhesion) are compared with data from experimental studies of yeast particle engulfment by blood granulocytes and actin network dynamics in fishscale keratocytes.

  6. Trading in your spindles for blebs: the amoeboid tumor cell phenotype in prostate cancer

    Directory of Open Access Journals (Sweden)

    Samantha Morley

    2014-08-01

    Full Text Available Prostate cancer (PCa remains a principal cause of mortality in developed countries. Because no clinical interventions overcome resistance to androgen ablation therapy, management of castration resistance and metastatic disease remains largely untreatable. Metastasis is a multistep process in which tumor cells lose cell-cell contacts, egress from the primary tumor, intravasate, survive shear stress within the vasculature and extravasate into tissues to colonize ectopic sites. Tumor cells reestablish migratory behaviors employed during nonneoplastic processes such as embryonic development, leukocyte trafficking and wound healing. While mesenchymal motility is an established paradigm of dissemination, an alternate, 'amoeboid' phenotype is increasingly appreciated as relevant to human cancer. Here we discuss characteristics and pathways underlying the phenotype, and highlight our findings that the cytoskeletal regulator DIAPH3 governs the mesenchymal-amoeboid transition. We also describe our identification of a new class of tumor-derived microvesicles, large oncosomes, produced by amoeboid cells and with potential clinical utility in prostate and other cancers.

  7. An ezrin-rich, rigid uropod-like structure directs movement of amoeboid blebbing cells.

    Science.gov (United States)

    Lorentzen, Anna; Bamber, Jeffrey; Sadok, Amine; Elson-Schwab, Ilan; Marshall, Christopher J

    2011-04-15

    Melanoma cells can switch between an elongated mesenchymal-type and a rounded amoeboid-type migration mode. The rounded 'amoeboid' form of cell movement is driven by actomyosin contractility resulting in membrane blebbing. Unlike elongated A375 melanoma cells, rounded A375 cells do not display any obvious morphological front-back polarisation, although polarisation is thought to be a prerequisite for cell movement. We show that blebbing A375 cells are polarised, with ezrin (a linker between the plasma membrane and actin cytoskeleton), F-actin, myosin light chain, plasma membrane, phosphatidylinositol (4,5)-bisphosphate and β1-integrin accumulating at the cell rear in a uropod-like structure. This structure does not have the typical protruding shape of classical leukocyte uropods, but, as for those structures, it is regulated by protein kinase C. We show that the ezrin-rich uropod-like structure (ERULS) is an inherent feature of polarised A375 cells and not a consequence of cell migration, and is necessary for cell invasion. Furthermore, we demonstrate that membrane blebbing is reduced at this site, leading to a model in which the rigid ezrin-containing structure determines the direction of a moving cell through localised inhibition of membrane blebbing.

  8. A computational model of amoeboid cell swimming in unbounded medium and through obstacles

    Science.gov (United States)

    Campbell, Eric; Bagchi, Prosenjit

    2017-11-01

    Pseudopod-driven motility is commonly observed in eukaryotic cells. Pseudopodia are actin-rich protrusions of the cellular membrane which extend, bifurcate, and retract in cycles resulting in amoeboid locomotion. While actin-myosin interactions are responsible for pseudopod generation, cell deformability is crucial concerning pseudopod dynamics. Because pseudopodia are highly dynamic, cells are capable of deforming into complex shapes over time. Pseudopod-driven motility represents a multiscale and complex process, coupling cell deformation, protein biochemistry, and cytoplasmic and extracellular fluid motion. In this work, we present a 3D computational model of amoeboid cell swimming in an extracellular medium (ECM). The ECM is represented as a fluid medium with or without obstacles. The model integrates full cell deformation, a coarse-grain reaction-diffusion system for protein dynamics, and fluid interaction. Our model generates pseudopodia which bifurcate and retract, showing remarkable similarity to experimental observations. Influence of cell deformation, protein diffusivity and cytoplasmic viscosity on the swimming speed is analyzed in terms of altered pseudopod dynamics. Insights into the role of matrix porosity and obstacle size on cell motility are also provided. Funded by NSF CBET 1438255.

  9. Microglial Cells Prevent Hemorrhage in Neonatal Focal Arterial Stroke

    OpenAIRE

    Fernández-López, David; Faustino, Joel; Klibanov, Alexander L.; Derugin, Nikita; Blanchard, Elodie; Simon, Franziska; Leib, Stephen L.; Vexler, Zinaida S.

    2016-01-01

    Perinatal stroke leads to significant morbidity and long-term neurological and cognitive deficits. The pathophysiological mechanisms of brain damage depend on brain maturation at the time of stroke. To understand whether microglial cells limit injury after neonatal stroke by preserving neurovascular integrity, we subjected postnatal day 7 (P7) rats depleted of microglial cells, rats with inhibited microglial TGFbr2/ALK5 signaling, and corresponding controls, to transient middle cerebral arter...

  10. Peripheral viral infection induced microglial sensome genes and enhanced microglial cell activity in the hippocampus of neonatal piglets

    NARCIS (Netherlands)

    Ji, Peng; Schachtschneider, Kyle M.; Schook, Lawrence B.; Walker, Frederick R.; Johnson, Rodney W.

    2016-01-01

    Although poorly understood, early-life infection is predicted to affect brain microglial cells, making them hypersensitive to subsequent stimuli. To investigate this, we assessed gene expression in hippocampal tissue obtained from a previously published study reporting increased microglial cell

  11. Anti-inflammatory Effects of Curcumin in Microglial Cells

    Directory of Open Access Journals (Sweden)

    Yangyang Yu

    2018-04-01

    Full Text Available Lipoteichoic acid (LTA induces neuroinflammatory molecules, contributing to the pathogenesis of neurodegenerative diseases. Therefore, suppression of neuroinflammatory molecules could be developed as a therapeutic method. Although previous data supports an immune-modulating effect of curcumin, the underlying signaling pathways are largely unidentified. Here, we investigated curcumin’s anti-neuroinflammatory properties in LTA-stimulated BV-2 microglial cells. Inflammatory cytokine tumor necrosis factor-α [TNF-α, prostaglandin E2 (PGE2, and Nitric Oxide (NO] secretion in LTA-induced microglial cells were inhibited by curcumin. Curcumin also inhibited LTA-induced inducible NO synthases (iNOS and cyclooxygenase-2 (COX-2 expression. Subsequently, our mechanistic studies revealed that curcumin inhibited LTA-induced phosphorylation of mitogen-activated protein kinase (MAPK including ERK, p38, Akt and translocation of NF-κB. Furthermore, curcumin induced hemeoxygenase (HO-1HO-1 and nuclear factor erythroid 2-related factor 2 (Nrf-2 expression in microglial cells. Inhibition of HO-1 reversed the inhibition effect of HO-1 on inflammatory mediators release in LTA-stimulated microglial cells. Taken together, our results suggest that curcumin could be a potential therapeutic agent for the treatment of neurodegenerative disorders via suppressing neuroinflammatory responses.

  12. X-ray irradiation and Rho-kinase inhibitor additively induce invasiveness of the cells of the pancreatic cancer line, MIAPaCa-2, which exhibits mesenchymal and amoeboid motility

    International Nuclear Information System (INIS)

    Fujita, Mayumi; Otsuka, Yoshimi; Yamada, Shigeru; Iwakawa, Mayumi; Imai, Takashi

    2011-01-01

    Tumor cells can migrate and invade tissue by two modes of motility: mesenchymal and amoeboid. X-ray or γ-ray irradiation increases the invasiveness of tumor cells with mesenchymal motility through the induction of matrix metalloproteinases (MMP), and this increase is suppressed by MMP inhibitors (MMPI). However, the effects of X-ray or γ-ray irradiation on the invasiveness of tumor cells with amoeboid motility remain unclear. We investigated the effect of irradiation on amoeboid motility by using cells of the human pancreatic cancer line, MIAPaCa-2, which exhibits both modes of motility. The X-ray-induced invasiveness of MIAPaCa-2 cells was associated with the upregulation of MMP2 at both the RNA and protein levels and was inhibited by MMPI treatment. Amoeboid-mesenchymal transition was slightly induced after irradiation. The MMPI treatment caused mesenchymal-amoeboid transition without significant increase in invasiveness, while the ROCK inhibitor (ROCKI) stimulated amoeboid-mesenchymal transition and enhanced invasiveness under both non-irradiated and irradiated conditions. This ROCKI-induced transition was accompanied by the upregulation of MMP2 mRNA and protein. Exposure to both irradiation and ROCKI further enhanced MMP2 expression and had an additive effect on the invasiveness of MIAPaCa-2 cells. Additionally, exposure to MMPI led to significant suppression of both radiation-induced and the basal invasiveness of MIAPaCa-2 cells. This suggests that ROCKI treatment, especially with concomitant X-ray irradiation, can induce invasion of cancer cells and should be used only for certain types of cancer cells. Simultaneous use of inhibitors, ROCKI and MMPI may be effective in suppressing invasiveness under both X-ray-irradiated and non-irradiated conditions. (author)

  13. Microglial Cells Prevent Hemorrhage in Neonatal Focal Arterial Stroke.

    Science.gov (United States)

    Fernández-López, David; Faustino, Joel; Klibanov, Alexander L; Derugin, Nikita; Blanchard, Elodie; Simon, Franziska; Leib, Stephen L; Vexler, Zinaida S

    2016-03-09

    Perinatal stroke leads to significant morbidity and long-term neurological and cognitive deficits. The pathophysiological mechanisms of brain damage depend on brain maturation at the time of stroke. To understand whether microglial cells limit injury after neonatal stroke by preserving neurovascular integrity, we subjected postnatal day 7 (P7) rats depleted of microglial cells, rats with inhibited microglial TGFbr2/ALK5 signaling, and corresponding controls, to transient middle cerebral artery occlusion (tMCAO). Microglial depletion by intracerebral injection of liposome-encapsulated clodronate at P5 significantly reduced vessel coverage and triggered hemorrhages in injured regions 24 h after tMCAO. Lack of microglia did not alter expression or intracellular redistribution of several tight junction proteins, did not affect degradation of collagen IV induced by the tMCAO, but altered cell types producing TGFβ1 and the phosphorylation and intracellular distribution of SMAD2/3. Selective inhibition of TGFbr2/ALK5 signaling in microglia via intracerebral liposome-encapsulated SB-431542 delivery triggered hemorrhages after tMCAO, demonstrating that TGFβ1/TGFbr2/ALK5 signaling in microglia protects from hemorrhages. Consistent with observations in neonatal rats, depletion of microglia before tMCAO in P9 Cx3cr1(GFP/+)/Ccr2(RFP/+) mice exacerbated injury and induced hemorrhages at 24 h. The effects were independent of infiltration of Ccr2(RFP/+) monocytes into injured regions. Cumulatively, in two species, we show that microglial cells protect neonatal brain from hemorrhage after acute ischemic stroke. Copyright © 2016 the authors 0270-6474/16/362881-13$15.00/0.

  14. [Facial nerve injuries cause changes in central nervous system microglial cells].

    Science.gov (United States)

    Cerón, Jeimmy; Troncoso, Julieta

    2016-12-01

    Our research group has described both morphological and electrophysiological changes in motor cortex pyramidal neurons associated with contralateral facial nerve injury in rats. However, little is known about those neural changes, which occur together with changes in surrounding glial cells. To characterize the effect of the unilateral facial nerve injury on microglial proliferation and activation in the primary motor cortex. We performed immunohistochemical experiments in order to detect microglial cells in brain tissue of rats with unilateral facial nerve lesion sacrificed at different times after the injury. We caused two types of lesions: reversible (by crushing, which allows functional recovery), and irreversible (by section, which produces permanent paralysis). We compared the brain tissues of control animals (without surgical intervention) and sham-operated animals with animals with lesions sacrificed at 1, 3, 7, 21 or 35 days after the injury. In primary motor cortex, the microglial cells of irreversibly injured animals showed proliferation and activation between three and seven days post-lesion. The proliferation of microglial cells in reversibly injured animals was significant only three days after the lesion. Facial nerve injury causes changes in microglial cells in the primary motor cortex. These modifications could be involved in the generation of morphological and electrophysiological changes previously described in the pyramidal neurons of primary motor cortex that command facial movements.

  15. Microglial pathology

    OpenAIRE

    Streit, Wolfgang J; Xue, Qing-Shan; Tischer, Jasmin; Bechmann, Ingo

    2014-01-01

    This paper summarizes pathological changes that affect microglial cells in the human brain during aging and in aging-related neurodegenerative diseases, primarily Alzheimer’s disease (AD). It also provides examples of microglial changes that have been observed in laboratory animals during aging and in some experimentally induced lesions and disease models. Dissimilarities and similarities between humans and rodents are discussed in an attempt to generate a current understanding of microglial ...

  16. Establishment of mouse neuron and microglial cell co-cultured models and its action mechanism.

    Science.gov (United States)

    Zhang, Bo; Yang, Yunfeng; Tang, Jun; Tao, Yihao; Jiang, Bing; Chen, Zhi; Feng, Hua; Yang, Liming; Zhu, Gang

    2017-06-27

    The objective of this study is to establish a co-culture model of mouse neurons and microglial cells, and to analyze the mechanism of action of oxygen glucose deprivation (OGD) and transient oxygen glucose deprivation (tOGD) preconditioning cell models. Mouse primary neurons and BV2 microglial cells were successfully cultured, and the OGD and tOGD models were also established. In the co-culture of mouse primary neurons and microglial cells, the cell number of tOGD mouse neurons and microglial cells was larger than the OGD cell number, observed by a microscope. CCK-8 assay result showed that at 1h after treatment, the OD value in the control group is lower compared to all the other three groups (P control group compared to other three groups (P neurons cells were cultured. In the meantime mouse BV2 microglia cells were cultured. Two types of cells were co-cultured, and OGD and tOGD cell models were established. There were four groups in the experiment: control group (OGD), treatment group (tOGD+OGD), placebo group (tOGD+OGD+saline) and minocycline intervention group (tOGD+OGD+minocycline). CCK-8 kit was used to detect cell viability and flow cytometry was used to detect apoptosis. In this study, mouse primary neurons and microglial cells were co-cultured. The OGD and tOGD models were established successfully. tOGD was able to effectively protect neurons and microglial cells from damage, and inhibit the apoptosis caused by oxygen glucose deprivation.

  17. Exosomes from metastatic cancer cells transfer amoeboid phenotype to non-metastatic cells and increase endothelial permeability: their emerging role in tumor heterogeneity.

    Science.gov (United States)

    Schillaci, Odessa; Fontana, Simona; Monteleone, Francesca; Taverna, Simona; Di Bella, Maria Antonietta; Di Vizio, Dolores; Alessandro, Riccardo

    2017-07-05

    The goal of this study was to understand if exosomes derived from high-metastatic cells may influence the behavior of less aggressive cancer cells and the properties of the endothelium. We found that metastatic colon cancer cells are able to transfer their amoeboid phenotype to isogenic primary cancer cells through exosomes, and that this morphological transition is associated with the acquisition of a more aggressive behavior. Moreover, exosomes from the metastatic line (SW620Exos) exhibited higher ability to cause endothelial hyperpermeability than exosomes from the non metastatic line (SW480Exos). SWATH-based quantitative proteomic analysis highlighted that SW620Exos are significantly enriched in cytoskeletal-associated proteins including proteins activating the RhoA/ROCK pathway, known to induce amoeboid properties and destabilization of endothelial junctions. In particular, thrombin was identified as a key mediator of the effects induced by SW620Exos in target cells, in which we also found a significant increase of RhoA activity. Overall, our results demonstrate that in a heterogeneous context exosomes released by aggressive sub-clones can contribute to accelerate tumor progression by spreading malignant properties that affect both the tumor cell plasticity and the endothelial cell behavior.

  18. Immortalized sheep microglial cells are permissive to a diverse range of ruminant viruses.

    Science.gov (United States)

    Stanton, James B; Swanson, Beryl; Orozco, Edith; Muñoz-Gutiérrez, Juan F; Evermann, James F; Ridpath, Julia F

    2017-12-01

    Ruminants, including sheep and goats (small ruminants), are key agricultural animals in many parts of the world. Infectious diseases, including many viral diseases, are significant problems to efficient production of ruminants. Unfortunately, reagents tailored to viruses of ruminants, and especially small ruminants, are lacking compared to other animals more typically used for biomedical research. The purpose of this study was to determine the permissibility of a stably immortalized, sheep microglial cell line to viruses that are reported to infect ruminants: bovine viral diarrhea virus (BVDV), bovine herpesvirus 1 (BoHV-1), small ruminant lentiviruses (SRLV), and bovine respiratory syncytial virus (BRSV). Sublines A and H of previously isolated, immortalized, and characterized (CD14-positive) ovine microglial cells were used. Bovine turbinate cells and goat synovial membrane cells were used for comparison. Cytopathic changes were used to confirm infection of individual wells, which were then counted and used to calculate the 50% tissue culture infectious dose. Uninoculated cells served as negative controls and confirmed that the cells were not previously infected with these viruses using polymerase chain reaction (PCR). Inoculation of the two microglial cell sublines with laboratory and field isolates of BVDV, BoHV-1, and BRSV resulted in viral infection in a manner similar to bovine turbinate cells. Immortalized microglia cells are also permissive to SRLV, similar to goat synovial membrane cells. These immortalized sheep microglial cells provide a new tool for the study of ruminant viruses in ruminant microglial cell line.

  19. HMEC-1 adopt the mixed amoeboid-mesenchymal migration type during EndMT.

    Science.gov (United States)

    Kryczka, Jakub; Przygodzka, Patrycja; Bogusz, Helena; Boncela, Joanna

    2017-06-01

    The contribution of endothelial cells to scar and fibrotic tissue formation is undisputedly connected to their ability to undergo the endothelial-to-mesenchymal transition (EndMT) towards fibroblast phenotype-resembling cells. The migration model of fibroblasts and fibroblast-resembling cells is still not fully understood. It may be either a Rho/ROCK-independent, an integrin- and MMP-correlated ECM degradation-dependent, a mesenchymal model or Rho/ROCK-dependent, integrin adhesion- and MMP activity-independent, an amoeboid model. Here, we hypothesized that microvascular endothelial cells (HMEC-1) undergoing EndMT adopt an intermediate state of drifting migration model between the mesenchymal and amoeboid protrusive types in the early stages of fibrosis. We characterized the response of HMEC-1 to TGF-β2, a well-known mediator of EndMT within the microvasculature. We observed that TGF-β2 induces up to an intermediate mesenchymal phenotype in HMEC-1. In parallel, MMP-2 is upregulated and is responsible for most proteolytic activity. Interestingly, the migration of HMEC-1 undergoing EndMT is dependent on both ECM degradation and invadosome formation associated with MMP-2 proteolytic activity and Rho/ROCK cytoskeleton contraction. In conclusion, the transition from mesenchymal towards amoeboid movement highlights a molecular plasticity mechanism in endothelial cell migration in skin fibrosis. Copyright © 2017 Elsevier GmbH. All rights reserved.

  20. Three-dimensional simulation of pseudopod-driven swimming of amoeboid cells

    Science.gov (United States)

    Campbell, Eric; Bagchi, Prosenjit

    2016-11-01

    Pseudopod-driven locomotion is common in eukaryotic cells, such as amoeba, neutrophils, and cancer cells. Pseudopods are protrusions of the cell body that grow, bifurcate, and retract. Due to the dynamic nature of pseudopods, the shape of a motile cell constantly changes. The actin-myosin protein dynamics is a likely mechanism for pseudopod growth. Existing theoretical models often focus on the acto-myosin dynamics, and not the whole cell shape dynamics. Here we present a full 3D simulation of pseudopod-driven motility by coupling a surface-bound reaction-diffusion (RD) model for the acto-myosin dynamics, a continuum model for the cell membrane deformation, and flow of the cytoplasmic and extracellular fluids. The whole cell is represented as a viscous fluid surrounded by a membrane. A finite-element method is used to solve the membrane deformation, and the RD model on the deforming membrane, while a finite-difference/spectral method is used to solve the flow fields inside and outside the cell. The fluid flow and cell deformation are coupled by the immersed-boundary method. The model predicts pseudopod growth, bifurcation, and retraction as observed for a swimming amoeba. The work provides insights on the role of membrane stiffness and cytoplasmic viscosity on amoeboid swimming. Funded by NSF CBET 1438255.

  1. Induction of Microglial Activation by Mediators Released from Mast Cells

    Directory of Open Access Journals (Sweden)

    Xiang Zhang

    2016-04-01

    Full Text Available Background/Aims: Microglia are the resident immune cells in the brain and play a pivotal role in immune surveillance in the central nervous system (CNS. Brain mast cells are activated in CNS disorders and induce the release of several mediators. Thus, brain mast cells, rather than microglia, are the “first responders” due to injury. However, the functional aspects of mast cell-microglia interactions remain uninvestigated. Methods: Conditioned medium from activated HMC-1 cells induces microglial activation similar to co-culture of microglia with HMC-1 cells. Primary cultured microglia were examined by flow cytometry analysis and confocal microscopy. TNF- alpha and IL-6 were measured with commercial ELISA kits. Cell signalling was analysed by Western blotting. Results: In the present study, we found that the conditioned medium from activated HMC-1 cells stimulated microglial activation and the subsequent production of the pro-inflammatory factors TNF-α and IL-6. Co-culture of microglia and HMC-1 cells with corticotropin-releasing hormone (CRH for 24, 48 and 72 hours increased TNF-α and IL-6 production. Antagonists of histamine receptor 1 (H1R, H4R, proteinase-activated receptor 2 (PAR2 or Toll-like receptor 4 (TLR4 reduced HMC-1-induced pro-inflammatory factor production and MAPK and PI3K/AKT pathway activation. Conclusions: These results imply that activated mast cells trigger microglial activation. Interactions between mast cells and microglia could constitute a new and unique therapeutic target for CNS inflammation-related diseases.

  2. Microglial pathology.

    Science.gov (United States)

    Streit, Wolfgang J; Xue, Qing-Shan; Tischer, Jasmin; Bechmann, Ingo

    2014-09-26

    This paper summarizes pathological changes that affect microglial cells in the human brain during aging and in aging-related neurodegenerative diseases, primarily Alzheimer's disease (AD). It also provides examples of microglial changes that have been observed in laboratory animals during aging and in some experimentally induced lesions and disease models. Dissimilarities and similarities between humans and rodents are discussed in an attempt to generate a current understanding of microglial pathology and its significance during aging and in the pathogenesis of Alzheimer dementia (AD). The identification of dystrophic (senescent) microglia has created an ostensible conflict with prior work claiming a role for activated microglia and neuroinflammation during normal aging and in AD, and this has raised a basic question: does the brain's immune system become hyperactive (inflamed) or does it become weakened (senescent) in elderly and demented people, and what is the impact on neuronal function and cognition? Here we strive to reconcile these seemingly contradictory notions by arguing that both low-grade neuroinflammation and microglial senescence are the result of aging-associated free radical injury. Both processes are damaging for microglia as they synergistically exhaust this essential cell population to the point where the brain's immune system is effete and unable to support neuronal function.

  3. Immunological Demyelination Triggers Macrophage/Microglial Cells Activation without Inducing Astrogliosis

    Directory of Open Access Journals (Sweden)

    Frank Cloutier

    2013-01-01

    Full Text Available The glial scar formed by reactive astrocytes and axon growth inhibitors associated with myelin play important roles in the failure of axonal regeneration following central nervous system (CNS injury. Our laboratory has previously demonstrated that immunological demyelination of the CNS facilitates regeneration of severed axons following spinal cord injury. In the present study, we evaluate whether immunological demyelination is accompanied with astrogliosis. We compared the astrogliosis and macrophage/microglial cell responses 7 days after either immunological demyelination or a stab injury to the dorsal funiculus. Both lesions induced a strong activated macrophage/microglial cells response which was significantly higher within regions of immunological demyelination. However, immunological demyelination regions were not accompanied by astrogliosis compared to stab injury that induced astrogliosis which extended several millimeters above and below the lesions, evidenced by astroglial hypertrophy, formation of a glial scar, and upregulation of intermediate filaments glial fibrillary acidic protein (GFAP. Moreover, a stab or a hemisection lesion directly within immunological demyelination regions did not induced astrogliosis within the immunological demyelination region. These results suggest that immunological demyelination creates a unique environment in which astrocytes do not form a glial scar and provides a unique model to understand the putative interaction between astrocytes and activated macrophage/microglial cells.

  4. Salidroside Reduces Cell Mobility via NF-κB and MAPK Signaling in LPS-Induced BV2 Microglial Cells

    Directory of Open Access Journals (Sweden)

    Haixia Hu

    2014-01-01

    Full Text Available The unregulated activation of microglia following stroke results in the production of toxic factors that propagate secondary neuronal injury. Salidroside has been shown to exhibit protective effects against neuronal death induced by different insults. However, the molecular mechanisms responsible for the anti-inflammatory activity of salidroside have not been elucidated clearly in microglia. In the present study, we investigated the molecular mechanism underlying inhibiting LPS-stimulated BV2 microglial cell mobility of salidroside. The protective effect of salidroside was investigated in microglial BV2 cell, subjected to stretch injury. Moreover, transwell migration assay demonstrated that salidroside significantly reduced cell motility. Our results also indicated that salidroside suppressed LPS-induced chemokines production in a dose-dependent manner, without causing cytotoxicity in BV2 microglial cells. Moreover, salidroside suppressed LPS-induced activation of nuclear factor kappa B (NF-κB by blocking degradation of IκBα and phosphorylation of MAPK (p38, JNK, ERK1/2, which resulted in inhibition of chemokine expression. These results suggest that salidroside possesses a potent suppressive effect on cell migration of BV2 microglia and this compound may offer substantial therapeutic potential for treatment of ischemic strokes that are accompanied by microglial activation.

  5. Dextromethorphan inhibition of voltage-gated proton currents in BV2 microglial cells.

    Science.gov (United States)

    Song, Jin-Ho; Yeh, Jay Z

    2012-05-10

    Dextromethorphan, an antitussive drug, has a neuroprotective property as evidenced by its inhibition of microglial production of pro-inflammatory cytokines and reactive oxygen species. The microglial activation requires NADPH oxidase activity, which is sustained by voltage-gated proton channels in microglia as they dissipate an intracellular acid buildup. In the present study, we examined the effect of dextromethorphan on proton currents in microglial BV2 cells. Dextromethorphan reversibly inhibited proton currents with an IC(50) value of 51.7 μM at an intracellular/extracellular pH gradient of 5.5/7.3. Dextromethorphan did not change the reversal potential or the voltage dependence of the gating. Dextrorphan and 3-hydroxymorphinan, major metabolites of dextromethorphan, and dextromethorphan methiodide were ineffective in inhibiting proton currents. The results indicate that dextromethorphan inhibition of proton currents would suppress NADPH oxidase activity and, eventually, microglial activation. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  6. mDia2 and CXCL12/CXCR4 chemokine signaling intersect to drive tumor cell amoeboid morphological transitions.

    Science.gov (United States)

    Wyse, Meghan M; Goicoechea, Silvia; Garcia-Mata, Rafael; Nestor-Kalinoski, Andrea L; Eisenmann, Kathryn M

    2017-03-04

    Morphological plasticity in response to environmental cues in migrating cancer cells requires F-actin cytoskeletal rearrangements. Conserved formin family proteins play critical roles in cell shape, tumor cell motility, invasion and metastasis, in part, through assembly of non-branched actin filaments. Diaphanous-related formin-2 (mDia2/Diaph3/Drf3/Dia) regulates mesenchymal-to-amoeboid morphological conversions and non-apoptotic blebbing in tumor cells by interacting with its inhibitor diaphanous-interacting protein (DIP), and disrupting cortical F-actin assembly and bundling. F-actin disruption is initiated by a CXCL12-dependent mechanism. Downstream CXCL12 signaling partners inducing mDia2-dependent amoeboid conversions remain enigmatic. We found in MDA-MB-231 tumor cells CXCL12 induces DIP and mDia2 interaction in blebs, and engages its receptor CXCR4 to induce RhoA-dependent blebbing. mDia2 and CXCR4 associate in blebs upon CXCL12 stimulation. Both CXCR4 and RhoA are required for CXCL12-induced blebbing. Neither CXCR7 nor other Rho GTPases that activate mDia2 are required for CXCL12-induced blebbing. The Rho Guanine Nucleotide Exchange Factor (GEF) Net1 is required for CXCL12-driven RhoA activation and subsequent blebbing. These results reveal CXCL12 signaling, through CXCR4, directs a Net1/RhoA/mDia-dependent signaling hub to drive cytoskeleton rearrangements to regulate morphological plasticity in tumor cells. These signaling hubs may be conserved during normal and cancer cells responding to chemotactic cues. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Antipsychotics, chlorpromazine and haloperidol inhibit voltage-gated proton currents in BV2 microglial cells.

    Science.gov (United States)

    Shin, Hyewon; Song, Jin-Ho

    2014-09-05

    Microglial dysfunction and neuroinflammation are thought to contribute to the pathogenesis of schizophrenia. Some antipsychotic drugs have anti-inflammatory activity and can reduce the secretion of pro-inflammatory cytokines and reactive oxygen species from activated microglial cells. Voltage-gated proton channels on the microglial cells participate in the generation of reactive oxygen species and neuronal toxicity by supporting NADPH oxidase activity. In the present study, we examined the effects of two typical antipsychotics, chlorpromazine and haloperidol, on proton currents in microglial BV2 cells using the whole-cell patch clamp method. Chlorpromazine and haloperidol potently inhibited proton currents with IC50 values of 2.2 μM and 8.4 μM, respectively. Chlorpromazine and haloperidol are weak bases that can increase the intracellular pH, whereby they reduce the proton gradient and affect channel gating. Although the drugs caused a marginal positive shift of the activation voltage, they did not change the reversal potential. This suggested that proton current inhibition was not due to an alteration of the intracellular pH. Chlorpromazine and haloperidol are strong blockers of dopamine receptors. While dopamine itself did not affect proton currents, it also did not alter proton current inhibition by the two antipsychotics, indicating dopamine receptors are not likely to mediate the proton current inhibition. Given that proton channels are important for the production of reactive oxygen species and possibly pro-inflammatory cytokines, the anti-inflammatory and antipsychotic activities of chlorpromazine and haloperidol may be partly derived from their ability to inhibit microglial proton currents. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Levo-Tetrahydropalmatine Attenuates Bone Cancer Pain by Inhibiting Microglial Cells Activation

    Directory of Open Access Journals (Sweden)

    Mao-yin Zhang

    2015-01-01

    Full Text Available Objective. The present study is to investigate the analgesic roles of L-THP in rats with bone cancer pain caused by tumor cell implantation (TCI. Methods. Thermal hyperalgesia and mechanical allodynia were measured at different time points before and after operation. L-THP (20, 40, and 60 mg/kg were administrated intragastrically at early phase of postoperation (before pain appearance and later phase of postoperation (after pain appearance, respectively. The concentrations of TNF-α, IL-1β, and IL-18 in spinal cord were measured by enzyme-linked immunosorbent assay. Western blot was used to test the activation of astrocytes and microglial cells in spinal cord after TCI treatment. Results. TCI treatment induced significant thermal hyperalgesia and mechanical allodynia. Administration of L-THP at high doses significantly prevented and/or reversed bone cancer-related pain behaviors. Besides, TCI-induced activation of microglial cells and the increased levels of TNF-α and IL-18 were inhibited by L-THP administration. However, L-THP failed to affect TCI-induced astrocytes activation and IL-1β increase. Conclusion. This study suggests the possible clinical utility of L-THP in the treatment of bone cancer pain. The analgesic effects of L-THP on bone cancer pain maybe underlying the inhibition of microglial cells activation and proinflammatory cytokines increase.

  9. TAM receptors regulate multiple features of microglial physiology.

    Science.gov (United States)

    Fourgeaud, Lawrence; Través, Paqui G; Tufail, Yusuf; Leal-Bailey, Humberto; Lew, Erin D; Burrola, Patrick G; Callaway, Perri; Zagórska, Anna; Rothlin, Carla V; Nimmerjahn, Axel; Lemke, Greg

    2016-04-14

    Microglia are damage sensors for the central nervous system (CNS), and the phagocytes responsible for routine non-inflammatory clearance of dead brain cells. Here we show that the TAM receptor tyrosine kinases Mer and Axl regulate these microglial functions. We find that adult mice deficient in microglial Mer and Axl exhibit a marked accumulation of apoptotic cells specifically in neurogenic regions of the CNS, and that microglial phagocytosis of the apoptotic cells generated during adult neurogenesis is normally driven by both TAM receptor ligands Gas6 and protein S. Using live two-photon imaging, we demonstrate that the microglial response to brain damage is also TAM-regulated, as TAM-deficient microglia display reduced process motility and delayed convergence to sites of injury. Finally, we show that microglial expression of Axl is prominently upregulated in the inflammatory environment that develops in a mouse model of Parkinson's disease. Together, these results establish TAM receptors as both controllers of microglial physiology and potential targets for therapeutic intervention in CNS disease.

  10. Anti-inflammatory effects of rhynchophylline and isorhynchophylline in mouse N9 microglial cells and the molecular mechanism.

    Science.gov (United States)

    Yuan, Dan; Ma, Bin; Yang, Jing-yu; Xie, Yuan-yuan; Wang, Li; Zhang, Li-jia; Kano, Yoshihiro; Wu, Chun-fu

    2009-12-01

    Excessive production of nitric oxide (NO) and proinflammatory cytokines from activated microglia contributes to human neurodegenerative disorders. Our previous study demonstrated the potent inhibition of lipopolysaccharide (LPS)-induced NO production in rat primary microglial cells by rhynchophylline (RIN) and isorhynchophylline (IRN), a pair of isomeric alkaloids of Uncaria rhynchophylla (Miq.) Jacks. that has been used in China for centuries as a "cognitive enhancer" as well as to treat strokes. We further investigated whether RIN and IRN effectively suppress release of proinflammatory cytokines in LPS-activated microglial cells and the underling molecular mechanism for the inhibition of microglial activation. RIN and IRN concentration-dependently attenuated LPS-induced production of proinflammatory cytokines such as TNF-alpha and IL-1beta as well as NO in mouse N9 microglial cells, with IRN showing more potent inhibition of microglial activation. The western blotting analysis indicated that the potential molecular mechanism for RIN or IRN-mediated attenuation was implicated in suppressions of iNOS protein level, phosphorylation of ERK and p38 MAPKs, and degradation of IkappaBalpha. In addition, the differential regulation of the three signaling pathways by two isomers was shown. Our results suggest that RIN and IRN may be effective therapeutic candidates for use in the treatment of neurodegenerative diseases accompanied by microglial activation.

  11. Phenotypic clustering: a novel method for microglial morphology analysis.

    Science.gov (United States)

    Verdonk, Franck; Roux, Pascal; Flamant, Patricia; Fiette, Laurence; Bozza, Fernando A; Simard, Sébastien; Lemaire, Marc; Plaud, Benoit; Shorte, Spencer L; Sharshar, Tarek; Chrétien, Fabrice; Danckaert, Anne

    2016-06-17

    Microglial cells are tissue-resident macrophages of the central nervous system. They are extremely dynamic, sensitive to their microenvironment and present a characteristic complex and heterogeneous morphology and distribution within the brain tissue. Many experimental clues highlight a strong link between their morphology and their function in response to aggression. However, due to their complex "dendritic-like" aspect that constitutes the major pool of murine microglial cells and their dense network, precise and powerful morphological studies are not easy to realize and complicate correlation with molecular or clinical parameters. Using the knock-in mouse model CX3CR1(GFP/+), we developed a 3D automated confocal tissue imaging system coupled with morphological modelling of many thousands of microglial cells revealing precise and quantitative assessment of major cell features: cell density, cell body area, cytoplasm area and number of primary, secondary and tertiary processes. We determined two morphological criteria that are the complexity index (CI) and the covered environment area (CEA) allowing an innovative approach lying in (i) an accurate and objective study of morphological changes in healthy or pathological condition, (ii) an in situ mapping of the microglial distribution in different neuroanatomical regions and (iii) a study of the clustering of numerous cells, allowing us to discriminate different sub-populations. Our results on more than 20,000 cells by condition confirm at baseline a regional heterogeneity of the microglial distribution and phenotype that persists after induction of neuroinflammation by systemic injection of lipopolysaccharide (LPS). Using clustering analysis, we highlight that, at resting state, microglial cells are distributed in four microglial sub-populations defined by their CI and CEA with a regional pattern and a specific behaviour after challenge. Our results counteract the classical view of a homogenous regional resting

  12. Data from SILAC-based quantitative analysis of lysates from mouse microglial cells treated with Withaferin A (WA).

    Science.gov (United States)

    Narayan, Malathi; Seeley, Kent W; Jinwal, Umesh K

    2016-06-01

    Mass spectrometry data collected in a study analyzing the effect of withaferin A (WA) on a mouse microglial (N9) cell line is presented in this article. Data was collected from SILAC-based quantitative analysis of lysates from mouse microglial cells treated with either WA or DMSO vehicle control. This article reports all the proteins that were identified in this analysis. The data presented here is related to the published research article on the effect of WA on the differential regulation of proteins in mouse microglial cells [1]. Mass spectrometry data has also been deposited in the ProteomeXchange with the identifier PXD003032.

  13. Data from SILAC-based quantitative analysis of lysates from mouse microglial cells treated with Withaferin A (WA

    Directory of Open Access Journals (Sweden)

    Malathi Narayan

    2016-06-01

    Full Text Available Mass spectrometry data collected in a study analyzing the effect of withaferin A (WA on a mouse microglial (N9 cell line is presented in this article. Data was collected from SILAC-based quantitative analysis of lysates from mouse microglial cells treated with either WA or DMSO vehicle control. This article reports all the proteins that were identified in this analysis. The data presented here is related to the published research article on the effect of WA on the differential regulation of proteins in mouse microglial cells [1]. Mass spectrometry data has also been deposited in the ProteomeXchange with the identifier http://www.ebi.ac.uk/pride/archive/projects/PXD003032.

  14. Tubulin cofactor B regulates microtubule densities during microglia transition to the reactive states

    International Nuclear Information System (INIS)

    Fanarraga, M.L.; Villegas, J.C.; Carranza, G.; Castano, R.; Zabala, J.C.

    2009-01-01

    Microglia are highly dynamic cells of the CNS that continuously survey the welfare of the neural parenchyma and play key roles modulating neurogenesis and neuronal cell death. In response to injury or pathogen invasion parenchymal microglia transforms into a more active cell that proliferates, migrates and behaves as a macrophage. The acquisition of these extra skills implicates enormous modifications of the microtubule and actin cytoskeletons. Here we show that tubulin cofactor B (TBCB), which has been found to contribute to various aspects of microtubule dynamics in vivo, is also implicated in microglial cytoskeletal changes. We find that TBCB is upregulated in post-lesion reactive parenchymal microglia/macrophages, in interferon treated BV-2 microglial cells, and in neonate amoeboid microglia where the microtubule densities are remarkably low. Our data demonstrate that upon TBCB downregulation both, after microglia differentiation to the ramified phenotype in vivo and in vitro, or after TBCB gene silencing, microtubule densities are restored in these cells. Taken together these observations support the view that TBCB functions as a microtubule density regulator in microglia during activation, and provide an insight into the understanding of the complex mechanisms controlling microtubule reorganization during microglial transition between the amoeboid, ramified, and reactive phenotypes

  15. Dystrophic (senescent) rather than activated microglial cells are associated with tau pathology and likely precede neurodegeneration in Alzheimer's disease.

    Science.gov (United States)

    Streit, Wolfgang J; Braak, Heiko; Xue, Qing-Shan; Bechmann, Ingo

    2009-10-01

    The role of microglial cells in the pathogenesis of Alzheimer's disease (AD) neurodegeneration is unknown. Although several works suggest that chronic neuroinflammation caused by activated microglia contributes to neurofibrillary degeneration, anti-inflammatory drugs do not prevent or reverse neuronal tau pathology. This raises the question if indeed microglial activation occurs in the human brain at sites of neurofibrillary degeneration. In view of the recent work demonstrating presence of dystrophic (senescent) microglia in aged human brain, the purpose of this study was to investigate microglial cells in situ and at high resolution in the immediate vicinity of tau-positive structures in order to determine conclusively whether degenerating neuronal structures are associated with activated or with dystrophic microglia. We used a newly optimized immunohistochemical method for visualizing microglial cells in human archival brain together with Braak staging of neurofibrillary pathology to ascertain the morphology of microglia in the vicinity of tau-positive structures. We now report histopathological findings from 19 humans covering the spectrum from none to severe AD pathology, including patients with Down's syndrome, showing that degenerating neuronal structures positive for tau (neuropil threads, neurofibrillary tangles, neuritic plaques) are invariably colocalized with severely dystrophic (fragmented) rather than with activated microglial cells. Using Braak staging of Alzheimer neuropathology we demonstrate that microglial dystrophy precedes the spread of tau pathology. Deposits of amyloid-beta protein (Abeta) devoid of tau-positive structures were found to be colocalized with non-activated, ramified microglia, suggesting that Abeta does not trigger microglial activation. Our findings also indicate that when microglial activation does occur in the absence of an identifiable acute central nervous system insult, it is likely to be the result of systemic infectious

  16. Zinc triggers microglial activation.

    Science.gov (United States)

    Kauppinen, Tiina M; Higashi, Youichirou; Suh, Sang Won; Escartin, Carole; Nagasawa, Kazuki; Swanson, Raymond A

    2008-05-28

    Microglia are resident immune cells of the CNS. When stimulated by infection, tissue injury, or other signals, microglia assume an activated, "ameboid" morphology and release matrix metalloproteinases, reactive oxygen species, and other proinflammatory factors. This innate immune response augments host defenses, but it can also contribute to neuronal death. Zinc is released by neurons under several conditions in which microglial activation occurs, and zinc chelators can reduce neuronal death in animal models of cerebral ischemia and neurodegenerative disorders. Here, we show that zinc directly triggers microglial activation. Microglia transfected with a nuclear factor-kappaB (NF-kappaB) reporter gene showed a severalfold increase in NF-kappaB activity in response to 30 microm zinc. Cultured mouse microglia exposed to 15-30 microm zinc increased nitric oxide production, increased F4/80 expression, altered cytokine expression, and assumed the activated morphology. Zinc-induced microglial activation was blocked by inhibiting NADPH oxidase, poly(ADP-ribose) polymerase-1 (PARP-1), or NF-kappaB activation. Zinc injected directly into mouse brain induced microglial activation in wild-type mice, but not in mice genetically lacking PARP-1 or NADPH oxidase activity. Endogenous zinc release, induced by cerebral ischemia-reperfusion, likewise induced a robust microglial reaction, and this reaction was suppressed by the zinc chelator CaEDTA. Together, these results suggest that extracellular zinc triggers microglial activation through the sequential activation of NADPH oxidase, PARP-1, and NF-kappaB. These findings identify a novel trigger for microglial activation and a previously unrecognized mechanism by which zinc may contribute to neurological disorders.

  17. Metastasis of aggressive amoeboid sarcoma cells is dependent on Rho/ROCK/MLC signaling

    Czech Academy of Sciences Publication Activity Database

    Kosla, Jan; Paňková, D.; Plachý, Jiří; Tolde, O.; Bicanova, K.; Dvořák, Michal; Rosel, D.; Brabek, J.

    2013-01-01

    Roč. 11, č. 1 (2013), s. 51 ISSN 1478-811X R&D Projects: GA MŠk(CZ) LC06061 Institutional support: RVO:68378050 Keywords : metastasis * sarcoma * rhoA * ROCK * MLC * amoeboid invasiveness * 3D environment * chicken model Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.672, year: 2013

  18. Inhibition of CD200R1 expression by C/EBP beta in reactive microglial cells

    Directory of Open Access Journals (Sweden)

    Dentesano Guido

    2012-07-01

    Full Text Available Abstract Background In physiological conditions, it is postulated that neurons control microglial reactivity through a series of inhibitory mechanisms, involving either cell contact-dependent, soluble-factor-dependent or neurotransmitter-associated pathways. In the current study, we focus on CD200R1, a microglial receptor involved in one of these cell contact-dependent mechanisms. CD200R1 activation by its ligand, CD200 (mainly expressed by neurons in the central nervous system,is postulated to inhibit the pro-inflammatory phenotype of microglial cells, while alterations in CD200-CD200R1 signalling potentiate this phenotype. Little is known about the regulation of CD200R1 expression in microglia or possible alterations in the presence of pro-inflammatory stimuli. Methods Murine primary microglial cultures, mixed glial cultures from wild-type and CCAAT/enhancer binding protein β (C/EBPβ-deficient mice, and the BV2 murine cell line overexpressing C/EBPβ were used to study the involvement of C/EBPβ transcription factor in the regulation of CD200R1 expression in response to a proinflammatory stimulus (lipopolysaccharide (LPS. Binding of C/EBPβ to the CD200R1 promoter was determined by quantitative chromatin immunoprecipitation (qChIP. The involvement of histone deacetylase 1 in the control of CD200R1 expression by C/EBPβ was also determined by co-immunoprecipitation and qChIP. Results LPS treatment induced a decrease in CD200R1 mRNA and protein expression in microglial cells, an effect that was not observed in the absence of C/EBPβ. C/EBPβ overexpression in BV2 cells resulted in a decrease in basal CD200R1 mRNA and protein expression. In addition, C/EBPβ binding to the CD200R1 promoter was observed in LPS-treated but not in control glial cells, and also in control BV2 cells overexpressing C/EBPβ. Finally, we observed that histone deacetylase 1 co-immunoprecipitated with C/EBPβ and showed binding to a C/EBPβ consensus sequence of the CD

  19. Automatic counting of microglial cell activation and its applications

    Directory of Open Access Journals (Sweden)

    Beatriz I Gallego

    2016-01-01

    Full Text Available Glaucoma is a multifactorial optic neuropathy characterized by the damage and death of the retinal ganglion cells. This disease results in vision loss and blindness. Any vision loss resulting from the disease cannot be restored and nowadays there is no available cure for glaucoma; however an early detection and treatment, could offer neuronal protection and avoid later serious damages to the visual function. A full understanding of the etiology of the disease will still require the contribution of many scientific efforts. Glial activation has been observed in glaucoma, being microglial proliferation a hallmark in this neurodegenerative disease. A typical project studying these cellular changes involved in glaucoma often needs thousands of images - from several animals - covering different layers and regions of the retina. The gold standard to evaluate them is the manual count. This method requires a large amount of time from specialized personnel. It is a tedious process and prone to human error. We present here a new method to count microglial cells by using a computer algorithm. It counts in one hour the same number of images that a researcher counts in four weeks, with no loss of reliability.

  20. Differential effects of lipopolysaccharide on energy metabolism in murine microglial N9 and cholinergic SN56 neuronal cells.

    Science.gov (United States)

    Klimaszewska-Łata, Joanna; Gul-Hinc, Sylwia; Bielarczyk, Hanna; Ronowska, Anna; Zyśk, Marlena; Grużewska, Katarzyna; Pawełczyk, Tadeusz; Szutowicz, Andrzej

    2015-04-01

    There are significant differences between acetyl-CoA and ATP levels, enzymes of acetyl-CoA metabolism, and toll-like receptor 4 contents in non-activated microglial N9 and non-differentiated cholinergic SN56 neuroblastoma cells. Exposition of N9 cells to lipopolysaccharide caused concentration-dependent several-fold increases of nitrogen oxide synthesis, accompanied by inhibition of pyruvate dehydrogenase complex, aconitase, and α-ketoglutarate dehydrogenase complex activities, and by nearly proportional depletion of acetyl-CoA, but by relatively smaller losses in ATP content and cell viability (about 5%). On the contrary, SN56 cells appeared to be insensitive to direct exposition to high concentration of lipopolysaccharide. However, exogenous nitric oxide resulted in marked inhibition pyruvate dehydrogenase and aconitase activities, depletion of acetyl-CoA, along with respective loss of SN56 cells viability. These data indicate that these two common neurodegenerative signals may differentially affect energy-acetyl-CoA metabolism in microglial and cholinergic neuronal cell compartments in the brain. Moreover, microglial cells appeared to be more resistant than neuronal cells to acetyl-CoA and ATP depletion evoked by these neurodegenerative conditions. Together, these data indicate that differential susceptibility of microglia and cholinergic neuronal cells to neurotoxic signals may result from differences in densities of toll-like receptors and degree of disequilibrium between acetyl-CoA provision in mitochondria and its utilization for energy production and acetylation reactions in each particular group of cells. There are significant differences between acetyl-CoA and ATP levels and enzymes of acetyl-CoA metabolism in non-activated microglial N9 and non-differentiated cholinergic SN56 neuroblastoma cells. Pathological stimulation of microglial toll-like receptors (TLRs) triggered excessive synthesis of microglia-derived nitric oxide (NO)/NOO radicals that

  1. Inhibitors of Microglial Neurotoxicity: Focus on Natural Products

    Directory of Open Access Journals (Sweden)

    Kyoungho Suk

    2011-01-01

    Full Text Available Microglial cells play a dual role in the central nervous system as they have both neurotoxic and neuroprotective effects. Uncontrolled and excessive activation of microglia often contributes to inflammation-mediated neurodegeneration. Recently, much attention has been paid to therapeutic strategies aimed at inhibiting neurotoxic microglial activation. Pharmacological inhibitors of microglial activation are emerging as a result of such endeavors. In this review, natural products-based inhibitors of microglial activation will be reviewed. Potential neuroprotective activity of these compounds will also be discussed. Future works should focus on the discovery of novel drug targets that specifically mediate microglial neurotoxicity rather than neuroprotection. Development of new drugs based on these targets may require a better understanding of microglial biology and neuroinflammation at the molecular, cellular, and systems levels.

  2. Zinc is released by cultured astrocytes as a gliotransmitter under hypoosmotic stress-loaded conditions and regulates microglial activity.

    Science.gov (United States)

    Segawa, Shohei; Nishiura, Takeshi; Furuta, Takahiro; Ohsato, Yuki; Tani, Misaki; Nishida, Kentaro; Nagasawa, Kazuki

    2014-01-17

    Astrocytes contribute to the maintenance of brain homeostasis via the release of gliotransmitters such as ATP and glutamate. Here we examined whether zinc was released from astrocytes under stress-loaded conditions, and was involved in the regulation of microglial activity as a gliotransmitter. Hypoosmotic stress was loaded to astrocytes using balanced salt solution prepared to 214-314 mOsmol/L, and then intra- and extra-cellular zinc levels were assessed using Newport Green DCF diacetate (NG) and ICP-MS, respectively. Microglial activation by the astrocytic supernatant was assessed by their morphological changes and poly(ADP-ribose) (PAR) polymer accumulation. Exposure of astrocytes to hypoosmotic buffer, increased the extracellular ATP level in osmolarity-dependent manners, indicating a load of hypoosmotic stress. In hypoosmotic stress-loaded astrocytes, there were apparent increases in the intra- and extra-cellular zinc levels. Incubation of microglia in the astrocytic conditioned medium transformed them into the activated "amoeboid" form and induced PAR formation. Administration of an extracellular zinc chelator, CaEDTA, to the astrocytic conditioned medium almost completely prevented the microglial activation. Treatment of astrocytes with an intracellular zinc chelator, TPEN, suppressed the hypoosmotic stress-increased intracellular, but not the extracellular, zinc level, and the increase in the intracellular zinc level was blocked partially by a nitric oxide synthase inhibitor, but not by CaEDTA, indicating that the mechanisms underlying the increases in the intra- and extra-cellular zinc levels might be different. These findings suggest that under hypoosmotic stress-loaded conditions, zinc is released from astrocytes and then plays a primary role in microglial activation as a gliotransmitter. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Estimation of absolute microglial cell numbers in mouse fascia dentata using unbiased and efficient stereological cell counting principles

    DEFF Research Database (Denmark)

    Wirenfeldt, Martin; Dalmau, Ishar; Finsen, Bente

    2003-01-01

    Stereology offers a set of unbiased principles to obtain precise estimates of total cell numbers in a defined region. In terms of microglia, which in the traumatized and diseased CNS is an extremely dynamic cell population, the strength of stereology is that the resultant estimate is unaffected...... of microglia, although with this thickness, the intensity of the staining is too high to distinguish single cells. Lectin histochemistry does not visualize microglia throughout the section and, accordingly, is not suited for the optical fractionator. The mean total number of Mac-1+ microglial cells...... in the unilateral dentate gyrus of the normal young adult male C57BL/6 mouse was estimated to be 12,300 (coefficient of variation (CV)=0.13) with a mean coefficient of error (CE) of 0.06. The perspective of estimating microglial cell numbers using stereology is to establish a solid basis for studying the dynamics...

  4. Formation of multinucleated giant cells and microglial degeneration in rats expressing a mutant Cu/Zn superoxide dismutase gene

    Directory of Open Access Journals (Sweden)

    Streit Wolfgang J

    2007-02-01

    Full Text Available Abstract Background Microglial neuroinflammation is thought to play a role in the pathogenesis of amyotrophic lateral sclerosis (ALS. The purpose of this study was to provide a histopathological evaluation of the microglial neuroinflammatory response in a rodent model of ALS, the SOD1G93A transgenic rat. Methods Multiple levels of the CNS from spinal cord to cerebral cortex were studied in SOD1G93A transgenic rats during three stages of natural disease progression, including presymptomatic, early symptomatic (onset, and late symptomatic (end stage, using immuno- and lectin histochemical markers for microglia, such as OX-42, OX-6, and Griffonia simplicifolia isolectin B4. Results Our studies revealed abnormal aggregates of microglia forming in the spinal cord as early as the presymptomatic stage. During the symptomatic stages there was prominent formation of multinucleated giant cells through fusion of microglial cells in the spinal cord, brainstem, and red nucleus of the midbrain. Other brain regions, including substantia nigra, cranial nerve nuclei, hippocampus and cortex showed normal appearing microglia. In animals during end stage disease at 4–5 months of age virtually all microglia in the spinal cord gray matter showed extensive fragmentation of their cytoplasm (cytorrhexis, indicative of widespread microglial degeneration. Few microglia exhibiting nuclear fragmentation (karyorrhexis indicative of apoptosis were identified at any stage. Conclusion The current findings demonstrate the occurrence of severe abnormalities in microglia, such as cell fusions and cytorrhexis, which may be the result of expression of mutant SOD1 in these cells. The microglial changes observed are different from those that accompany normal microglial activation, and they demonstrate that aberrant activation and degeneration of microglia is part of the pathogenesis of motor neuron disease.

  5. Stimulation of cannabinoid receptor 2 (CB2 suppresses microglial activation

    Directory of Open Access Journals (Sweden)

    Fernandez Francisco

    2005-12-01

    Full Text Available Abstract Background Activated microglial cells have been implicated in a number of neurodegenerative disorders, including Alzheimer's disease (AD, multiple sclerosis (MS, and HIV dementia. It is well known that inflammatory mediators such as nitric oxide (NO, cytokines, and chemokines play an important role in microglial cell-associated neuron cell damage. Our previous studies have shown that CD40 signaling is involved in pathological activation of microglial cells. Many data reveal that cannabinoids mediate suppression of inflammation in vitro and in vivo through stimulation of cannabinoid receptor 2 (CB2. Methods In this study, we investigated the effects of a cannabinoid agonist on CD40 expression and function by cultured microglial cells activated by IFN-γ using RT-PCR, Western immunoblotting, flow cytometry, and anti-CB2 small interfering RNA (siRNA analyses. Furthermore, we examined if the stimulation of CB2 could modulate the capacity of microglial cells to phagocytise Aβ1–42 peptide using a phagocytosis assay. Results We found that the selective stimulation of cannabinoid receptor CB2 by JWH-015 suppressed IFN-γ-induced CD40 expression. In addition, this CB2 agonist markedly inhibited IFN-γ-induced phosphorylation of JAK/STAT1. Further, this stimulation was also able to suppress microglial TNF-α and nitric oxide production induced either by IFN-γ or Aβ peptide challenge in the presence of CD40 ligation. Finally, we showed that CB2 activation by JWH-015 markedly attenuated CD40-mediated inhibition of microglial phagocytosis of Aβ1–42 peptide. Taken together, these results provide mechanistic insight into beneficial effects provided by cannabinoid receptor CB2 modulation in neurodegenerative diseases, particularly AD.

  6. LncRNA FIRRE/NF-kB feedback loop contributes to OGD/R injury of cerebral microglial cells.

    Science.gov (United States)

    Zang, Yunhua; Zhou, Xiyan; Wang, Qun; Li, Xia; Huang, Hailiang

    2018-04-28

    Stroke is one of the leading causes for serious long-term neurological disability. LncRNAs have been investigated to be dysregulated in ischemic stroke. However, the underlying mechanisms of some specific lncRNAs have not been clearly clarified. To determine lncRNA-mediated regulatory mechanism in ischemic stroke, we constructed OGD/R injury model of cerebral microglial cells. Microarray analysis was carried out and analyzed that lncRNA functional intergenic repeating RNA element (FIRRE) was associated with OGD/R injury. Based on the molecular biotechnology, we demonstrated that FIRRE could activate NF-kB signal pathway. Meanwhile, the activated NF-kB promoted FIRRE expression in OGD/R-treated cerebral microglial cells. Therefore, FIRRE and NF-kB formed a positive feedback loop to promote the transcription of NLRP3 inflammasome, thus contributed to the OGD/R injury of cerebral microglial cells. All findings in this study may help to explore novel and specific therapeutic target for ischemic stroke. Copyright © 2018. Published by Elsevier Inc.

  7. Curcumin is a potent modulator of microglial gene expression and migration

    Directory of Open Access Journals (Sweden)

    Aslanidis Alexander

    2011-09-01

    Full Text Available Abstract Background Microglial cells are important effectors of the neuronal innate immune system with a major role in chronic neurodegenerative diseases. Curcumin, a major component of tumeric, alleviates pro-inflammatory activities of these cells by inhibiting nuclear factor kappa B (NFkB signaling. To study the immuno-modulatory effects of curcumin on a transcriptomic level, DNA-microarray analyses were performed with resting and LPS-challenged microglial cells after short-term treatment with curcumin. Methods Resting and LPS-activated BV-2 cells were stimulated with curcumin and genome-wide mRNA expression patterns were determined using DNA-microarrays. Selected qRT-PCR analyses were performed to confirm newly identified curcumin-regulated genes. The migration potential of microglial cells was determined with wound healing assays and transwell migration assays. Microglial neurotoxicity was estimated by morphological analyses and quantification of caspase 3/7 levels in 661W photoreceptors cultured in the presence of microglia-conditioned medium. Results Curcumin treatment markedly changed the microglial transcriptome with 49 differentially expressed transcripts in a combined analysis of resting and activated microglial cells. Curcumin effectively triggered anti-inflammatory signals as shown by induced expression of Interleukin 4 and Peroxisome proliferator activated receptor α. Several novel curcumin-induced genes including Netrin G1, Delta-like 1, Platelet endothelial cell adhesion molecule 1, and Plasma cell endoplasmic reticulum protein 1, have been previously associated with adhesion and cell migration. Consequently, curcumin treatment significantly inhibited basal and activation-induced migration of BV-2 microglia. Curcumin also potently blocked gene expression related to pro-inflammatory activation of resting cells including Toll-like receptor 2 and Prostaglandin-endoperoxide synthase 2. Moreover, transcription of NO synthase 2 and

  8. Curcumin is a potent modulator of microglial gene expression and migration

    Science.gov (United States)

    2011-01-01

    Background Microglial cells are important effectors of the neuronal innate immune system with a major role in chronic neurodegenerative diseases. Curcumin, a major component of tumeric, alleviates pro-inflammatory activities of these cells by inhibiting nuclear factor kappa B (NFkB) signaling. To study the immuno-modulatory effects of curcumin on a transcriptomic level, DNA-microarray analyses were performed with resting and LPS-challenged microglial cells after short-term treatment with curcumin. Methods Resting and LPS-activated BV-2 cells were stimulated with curcumin and genome-wide mRNA expression patterns were determined using DNA-microarrays. Selected qRT-PCR analyses were performed to confirm newly identified curcumin-regulated genes. The migration potential of microglial cells was determined with wound healing assays and transwell migration assays. Microglial neurotoxicity was estimated by morphological analyses and quantification of caspase 3/7 levels in 661W photoreceptors cultured in the presence of microglia-conditioned medium. Results Curcumin treatment markedly changed the microglial transcriptome with 49 differentially expressed transcripts in a combined analysis of resting and activated microglial cells. Curcumin effectively triggered anti-inflammatory signals as shown by induced expression of Interleukin 4 and Peroxisome proliferator activated receptor α. Several novel curcumin-induced genes including Netrin G1, Delta-like 1, Platelet endothelial cell adhesion molecule 1, and Plasma cell endoplasmic reticulum protein 1, have been previously associated with adhesion and cell migration. Consequently, curcumin treatment significantly inhibited basal and activation-induced migration of BV-2 microglia. Curcumin also potently blocked gene expression related to pro-inflammatory activation of resting cells including Toll-like receptor 2 and Prostaglandin-endoperoxide synthase 2. Moreover, transcription of NO synthase 2 and Signal transducer and activator

  9. Fractalkine Attenuates Microglial Cell Activation Induced by Prenatal Stress

    Directory of Open Access Journals (Sweden)

    Joanna Ślusarczyk

    2016-01-01

    Full Text Available The potential contribution of inflammation to the development of neuropsychiatric diseases has recently received substantial attention. In the brain, the main immune cells are the microglia. As they are the main source of inflammatory factors, it is plausible that the regulation of their activation may be a potential therapeutic target. Fractalkine (CX3CL1 and its receptor CX3CR1 play a crucial role in the control of the biological activity of the microglia. In the present study, using microglial cultures we investigated whether fractalkine is able to reverse changes in microglia caused by a prenatal stress procedure. Our study found that the microglia do not express fractalkine. Prenatal stress decreases the expression of the fractalkine receptor, which in turn is enhanced by the administration of exogenous fractalkine. Moreover, treatment with fractalkine diminishes the prenatal stress-induced overproduction of proinflammatory factors such as IL-1β, IL-18, IL-6, TNF-α, CCL2, or NO in the microglial cells derived from prenatally stressed newborns. In conclusion, the present results revealed that the pathological activation of microglia in prenatally stressed newborns may be attenuated by fractalkine administration. Therefore, understanding of the role of the CX3CL1-CX3CR1 system may help to elucidate the mechanisms underlying the neuron-microglia interaction and its role in pathological conditions in the brain.

  10. P2Y12R-Dependent Translocation Mechanisms Gate the Changing Microglial Landscape

    Directory of Open Access Journals (Sweden)

    Ukpong B. Eyo

    2018-04-01

    Full Text Available Summary: Microglia are an exquisitely tiled and self-contained population in the CNS that do not receive contributions from circulating monocytes in the periphery. While microglia are long-lived cells, the extent to which their cell bodies are fixed and the molecular mechanisms by which the microglial landscape is regulated have not been determined. Using chronic in vivo two-photon imaging to follow the microglial population in young adult mice, we document a daily rearrangement of the microglial landscape. Furthermore, we show that the microglial landscape can be modulated by severe seizures, acute injury, and sensory deprivation. Finally, we demonstrate a critical role for microglial P2Y12Rs in regulating the microglial landscape through cellular translocation independent of proliferation. These findings suggest that microglial patrol the CNS through both process motility and soma translocation. : Using a chronic in vivo imaging approach, Eyo et al. show that the physical positions of brain microglia change daily and that these changes increase following certain experimental manipulations. The mechanism underlying these changes involves cell translocation controlled by microglial-specific P2Y12 receptors. Keywords: microglia, P2Y12, seizures, epilepsy, whisker trimming, microglial landscape, two photon chronic imaging

  11. Minocycline causes widespread cell death and increases microglial labeling in the neonatal mouse brain.

    Science.gov (United States)

    Strahan, J Alex; Walker, William H; Montgomery, Taylor R; Forger, Nancy G

    2017-06-01

    Minocycline, an antibiotic of the tetracycline family, inhibits microglia in many paradigms and is among the most commonly used tools for examining the role of microglia in physiological processes. Microglia may play an active role in triggering developmental neuronal cell death, although findings have been contradictory. To determine whether microglia influence developmental cell death, we treated perinatal mice with minocycline (45 mg/kg) and quantified effects on dying cells and microglial labeling using immunohistochemistry for activated caspase-3 (AC3) and ionized calcium-binding adapter molecule 1 (Iba1), respectively. Contrary to our expectations, minocycline treatment from embryonic day 18 to postnatal day (P)1 caused a > tenfold increase in cell death 8 h after the last injection in all brain regions examined, including the primary sensory cortex, septum, hippocampus and hypothalamus. Iba1 labeling was also increased in most regions. Similar effects, although of smaller magnitude, were seen when treatment was delayed to P3-P5. Minocycline treatment from P3 to P5 also decreased overall cell number in the septum at weaning, suggesting lasting effects of the neonatal exposure. When administered at lower doses (4.5 or 22.5 mg/kg), or at the same dose 1 week later (P10-P12), minocycline no longer increased microglial markers or cell death. Taken together, the most commonly used microglial "inhibitor" increases cell death and Iba1 labeling in the neonatal mouse brain. Minocycline is used clinically in infant and pediatric populations; caution is warrented when using minocycline in developing animals, or extrapolating the effects of this drug across ages. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 753-766, 2017. © 2016 Wiley Periodicals, Inc.

  12. Organization of hyperactive microglial cells in trigeminal spinal subnucleus caudalis and upper cervical spinal cord associated with orofacial neuropathic pain.

    Science.gov (United States)

    Shibuta, Kazuo; Suzuki, Ikuko; Shinoda, Masamichi; Tsuboi, Yoshiyuki; Honda, Kuniya; Shimizu, Noriyoshi; Sessle, Barry J; Iwata, Koichi

    2012-04-27

    The aim of this study was to evaluate spatial organization of hyperactive microglial cells in trigeminal spinal subnucleus caudalis (Vc) and upper cervical spinal cord (C1), and to clarify the involvement in mechanisms underlying orofacial secondary hyperalgesia following infraorbital nerve injury. We found that the head-withdrawal threshold to non-noxious mechanical stimulation of the maxillary whisker pad skin was significantly reduced in chronic constriction injury of the infraorbital nerve (ION-CCI) rats from day 1 to day 14 after ION-CCI. On day 3 after ION-CCI, mechanical allodynia was obvious in the orofacial skin areas innervated by the 1st and 3rd branches of the trigeminal nerve as well as the 2nd branch area. Hyperactive microglial cells in Vc and C1 were observed on days 3 and 7 after ION-CCI. On day 3 after ION-CCI, a large number of phosphorylated extracellular signal-regulated kinase (pERK)-immunoreactive (IR) cells were observed in Vc and C1. Many hyperactive microglial cells were also distributed over a wide area of Vc and C1 innervated by the trigeminal nerve. The intraperitoneal administration of minocycline significantly reduced the activation of microglial cells and the number of pERK-IR cells in Vc and C1, and also significantly attenuated the development of mechanical allodynia. Furthermore, enhanced background activity and mechanical evoked responses of Vc wide dynamic range neurons in ION-CCI rats were significantly reversed following minocycline administration. These findings suggest that activation of microglial cells over a wide area of Vc and C1 is involved in the enhancement of Vc and C1 neuronal excitability in the early period after ION-CCI, resulting in the neuropathic pain in orofacial areas innervated by the injured as well as uninjured nerves. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Plasminogen activator inhibitor type 1 regulates microglial motility and phagocytic activity

    Directory of Open Access Journals (Sweden)

    Jeon Hyejin

    2012-06-01

    Full Text Available Abstract Background Plasminogen activator inhibitor type 1 (PAI-1 is the primary inhibitor of urokinase type plasminogen activators (uPA and tissue type plasminogen activators (tPA, which mediate fibrinolysis. PAI-1 is also involved in the innate immunity by regulating cell migration and phagocytosis. However, little is known about the role of PAI-1 in the central nervous system. Methods In this study, we identified PAI-1 in the culture medium of mouse mixed glial cells by liquid chromatography and tandem mass spectrometry. Secretion of PAI-1 from glial cultures was detected by ELISA and western blotting analysis. Cell migration was evaluated by in vitro scratch-wound healing assay or Boyden chamber assay and an in vivo stab wound injury model. Phagocytic activity was measured by uptake of zymosan particles. Results The levels of PAI-1 mRNA and protein expression were increased by lipopolysaccharide and interferon-γ stimulation in both microglia and astrocytes. PAI-1 promoted the migration of microglial cells in culture via the low-density lipoprotein receptor-related protein (LRP 1/Janus kinase (JAK/signal transducer and activator of transcription (STAT1 axis. PAI-1 also increased microglial migration in vivo when injected into mouse brain. PAI-1-mediated microglial migration was independent of protease inhibition, because an R346A mutant of PAI-1 with impaired PA inhibitory activity also promoted microglial migration. Moreover, PAI-1 was able to modulate microglial phagocytic activity. PAI-1 inhibited microglial engulfment of zymosan particles in a vitronectin- and Toll-like receptor 2/6-dependent manner. Conclusion Our results indicate that glia-derived PAI-1 may regulate microglial migration and phagocytosis in an autocrine or paracrine manner. This may have important implications in the regulation of brain microglial activities in health and disease.

  14. Protective Effects of Curcumin on Manganese-Induced BV-2 Microglial Cell Death.

    Science.gov (United States)

    Park, Euteum; Chun, Hong Sung

    2017-08-01

    Curcumin, a bioactive component in tumeric, has been shown to exert antioxidant, anti-inflammatory, anticarcinogenic, hepatoprotective, and neuroprotective effects, but the effects of curcumin against manganese (Mn)-mediated neurotoxicity have not been studied. This study examined the protective effects of curcumin on Mn-induced cytotoxicity in BV-2 microglial cells. Curcumin (0.1-10 µM) dose-dependently prevented Mn (250 µM)-induced cell death. Mn-induced mitochondria-related apoptotic characteristics, such as caspase-3 and -9 activation, cytochrome c release, Bax increase, and Bcl-2 decrease, were significantly suppressed by curcumin. In addition, curcumin significantly increased intracellular glutathione (GSH) and moderately potentiated superoxide dismutase (SOD), both which were diminished by Mn treatment. Curcumin pretreatment effectively suppressed Mn-induced upregulation of malondialdehyde (MDA), total reactive oxygen species (ROS). Moreover, curcumin markedly inhibited the Mn-induced mitochondrial membrane potential (MMP) loss. Furthermore, curcumin was able to induce heme oxygenase (HO)-1 expression. Curcumin-mediated inhibition of ROS, down-regulation of caspases, restoration of MMP, and recovery of cell viability were partially reversed by HO-1 inhibitor (SnPP). These results suggest the first evidence that curcumin can prevent Mn-induced microglial cell death through the induction of HO-1 and regulation of oxidative stress, mitochondrial dysfunction, and apoptotic events.

  15. Exposure of cultured astroglial and microglial brain cells to 900 MHz microwave radiation.

    Science.gov (United States)

    Thorlin, Thorleif; Rouquette, Jean-Michel; Hamnerius, Yngve; Hansson, Elisabeth; Persson, Mikael; Björklund, Ulrika; Rosengren, Lars; Rönnbäck, Lars; Persson, Mikael

    2006-08-01

    The rapid rise in the use of mobile communications has raised concerns about health issues related to low-level microwave radiation. The head and brain are usually the most exposed targets in mobile phone users. In the brain, two types of glial cells, the astroglial and the microglial cells, are interesting in the context of biological effects from microwave exposure. These cells are widely distributed in the brain and are directly involved in the response to brain damage as well as in the development of brain cancer. The aim of the present study was to investigate whether 900 MHz radiation could affect these two different glial cell types in culture by studying markers for damage-related processes in the cells. Primary cultures enriched in astroglial cells were exposed to 900 MHz microwave radiation in a temperature-controlled exposure system at specific absorption rates (SARs) of 3 W/kg GSM modulated wave (mw) for 4, 8 and 24 h or 27 W/kg continuous wave (cw) for 24 h, and the release into the extracellular medium of the two pro-inflammatory cytokines interleukin 6 (Il6) and tumor necrosis factor-alpha (Tnfa) was analyzed. In addition, levels of the astroglial cell-specific reactive marker glial fibrillary acidic protein (Gfap), whose expression dynamics is different from that of cytokines, were measured in astroglial cultures and in astroglial cell-conditioned cell culture medium at SARs of 27 and 54 W/kg (cw) for 4 or 24 h. No significant differences could be detected for any of the parameters studied at any time and for any of the radiation characteristics. Total protein levels remained constant during the experiments. Microglial cell cultures were exposed to 900 MHz radiation at an SAR of 3 W/kg (mw) for 8 h, and I16, Tnfa, total protein and the microglial reactivity marker ED-1 (a macrophage activation antigen) were measured. No significant differences were found. The morphology of the cultured astroglial cells and microglia was studied and appeared to be

  16. Regulatory effects of fisetin on microglial activation.

    Science.gov (United States)

    Chuang, Jing-Yuan; Chang, Pei-Chun; Shen, Yi-Chun; Lin, Chingju; Tsai, Cheng-Fang; Chen, Jia-Hong; Yeh, Wei-Lan; Wu, Ling-Hsuan; Lin, Hsiao-Yun; Liu, Yu-Shu; Lu, Dah-Yuu

    2014-06-26

    Increasing evidence suggests that inflammatory processes in the central nervous system that are mediated by microglial activation play a key role in neurodegeneration. Fisetin, a plant flavonol commonly found in fruits and vegetables, is frequently added to nutritional supplements due to its antioxidant properties. In the present study, treatment with fisetin inhibited microglial cell migration and ROS (reactive oxygen species) production. Treatment with fisetin also effectively inhibited LPS plus IFN-γ-induced nitric oxide (NO) production, and inducible nitric oxide synthase (iNOS) expression in microglial cells. Furthermore, fisetin also reduced expressions of iNOS and NO by stimulation of peptidoglycan, the major component of the Gram-positive bacterium cell wall. Fisetin also inhibited the enhancement of LPS/IFN-γ- or peptidoglycan-induced inflammatory mediator IL (interlukin)-1 β expression. Besides the antioxidative and anti-inflammatory effects of fisetin, our study also elucidates the manner in fisetin-induced an endogenous anti-oxidative enzyme HO (heme oxygenase)-1 expression. Moreover, the regulatory molecular mechanism of fisetin-induced HO-1 expression operates through the PI-3 kinase/AKT and p38 signaling pathways in microglia. Notably, fisetin also significantly attenuated inflammation-related microglial activation and coordination deficit in mice in vivo. These findings suggest that fisetin may be a candidate agent for the development of therapies for inflammation-related neurodegenerative diseases.

  17. Regulatory Effects of Fisetin on Microglial Activation

    Directory of Open Access Journals (Sweden)

    Jing-Yuan Chuang

    2014-06-01

    Full Text Available Increasing evidence suggests that inflammatory processes in the central nervous system that are mediated by microglial activation play a key role in neurodegeneration. Fisetin, a plant flavonol commonly found in fruits and vegetables, is frequently added to nutritional supplements due to its antioxidant properties. In the present study, treatment with fisetin inhibited microglial cell migration and ROS (reactive oxygen species production. Treatment with fisetin also effectively inhibited LPS plus IFN-γ-induced nitric oxide (NO production, and inducible nitric oxide synthase (iNOS expression in microglial cells. Furthermore, fisetin also reduced expressions of iNOS and NO by stimulation of peptidoglycan, the major component of the Gram-positive bacterium cell wall. Fisetin also inhibited the enhancement of LPS/IFN-γ- or peptidoglycan-induced inflammatory mediator IL (interlukin-1 β expression. Besides the antioxidative and anti-inflammatory effects of fisetin, our study also elucidates the manner in fisetin-induced an endogenous anti-oxidative enzyme HO (heme oxygenase-1 expression. Moreover, the regulatory molecular mechanism of fisetin-induced HO-1 expression operates through the PI-3 kinase/AKT and p38 signaling pathways in microglia. Notably, fisetin also significantly attenuated inflammation-related microglial activation and coordination deficit in mice in vivo. These findings suggest that fisetin may be a candidate agent for the development of therapies for inflammation-related neurodegenerative diseases.

  18. The non-psychoactive plant cannabinoid, cannabidiol affects cholesterol metabolism-related genes in microglial cells.

    Science.gov (United States)

    Rimmerman, Neta; Juknat, Ana; Kozela, Ewa; Levy, Rivka; Bradshaw, Heather B; Vogel, Zvi

    2011-08-01

    Cannabidiol (CBD) is a non-psychoactive plant cannabinoid that is clinically used in a 1:1 mixture with the psychoactive cannabinoid Δ(9)-tetrahydrocannabinol (THC) for the treatment of neuropathic pain and spasticity in multiple sclerosis. Our group previously reported that CBD exerts anti-inflammatory effects on microglial cells. In addition, we found that CBD treatment increases the accumulation of the endocannabinoid N-arachidonoyl ethanolamine (AEA), thus enhancing endocannabinoid signaling. Here we proceeded to investigate the effects of CBD on the modulation of lipid-related genes in microglial cells. Cell viability was tested using FACS analysis, AEA levels were measured using LC/MS/MS, gene array analysis was validated with real-time qPCR, and cytokine release was measured using ELISA. We report that CBD significantly upregulated the mRNAs of the enzymes sterol-O-acyl transferase (Soat2), which synthesizes cholesteryl esters, and of sterol 27-hydroxylase (Cyp27a1). In addition, CBD increased the mRNA of the lipid droplet-associated protein, perilipin2 (Plin2). Moreover, we found that pretreatment of the cells with the cholesterol chelating agent, methyl-β-cyclodextrin (MBCD), reversed the CBD-induced increase in Soat2 mRNA but not in Plin2 mRNA. Incubation with AEA increased the level of Plin2, but not of Soat2 mRNA. Furthermore, MBCD treatment did not affect the reduction by CBD of the LPS-induced release of the proinflammatory cytokine IL-1β. CBD treatment modulates cholesterol homeostasis in microglial cells, and pretreatment with MBCD reverses this effect without interfering with CBD's anti-inflammatory effects. The effects of the CBD-induced increase in AEA accumulation on lipid-gene expression are discussed.

  19. Vaccinium bracteatum Thunb. Exerts Anti-Inflammatory Activity by Inhibiting NF-κB Activation in BV-2 Microglial Cells.

    Science.gov (United States)

    Kwon, Seung-Hwan; Ma, Shi-Xun; Ko, Yong-Hyun; Seo, Jee-Yeon; Lee, Bo-Ram; Lee, Taek Hwan; Kim, Sun Yeou; Lee, Seok-Yong; Jang, Choon-Gon

    2016-09-01

    This study was designed to evaluate the pharmacological effects of Vaccinium bracteatum Thunb. methanol extract (VBME) on microglial activation and to identify the underlying mechanisms of action of these effects. The anti-inflammatory properties of VBME were studied using lipopolysaccharide (LPS)-stimulated BV-2 microglial cells. We measured the production of nitric oxide (NO), inducible NO synthase (iNOS), cyclooxygenase (COX)-2, prostaglandin E₂ (PGE₂), tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), and interleukin-6 (IL-6) as inflammatory parameters. We also examined the effect of VBME on intracellular reactive oxygen species (ROS) production and the activity of nuclear factor-kappa B p65 (NF-κB p65). VBME significantly inhibited LPS-induced production of NO and PGE2 and LPS-mediated upregulation of iNOS and COX-2 expression in a dose-dependent manner; importantly, VBME was not cytotoxic. VBME also significantly reduced the generation of the pro-inflammatory cytokines TNF-α, IL-1β, and IL-6. In addition, VBME significantly dampened intracellular ROS production and suppressed NF-κB p65 translocation by blocking IκB-α phosphorylation and degradation in LPS-stimulated BV2 cells. Our findings indicate that VBME inhibits the production of inflammatory mediators in BV-2 microglial cells by suppressing NF-κB signaling. Thus, VBME may be useful in the treatment of neurodegenerative diseases due to its ability to inhibit inflammatory mediator production in activated BV-2 microglial cells.

  20. Myelin-specific T cells induce interleukin-1beta expression in lesion-reactive microglial-like cells in zones of axonal degeneration

    DEFF Research Database (Denmark)

    Grebing, Manuela; Nielsen, Helle H; Fenger, Christina D

    2016-01-01

    lesion-reactive CD11b(+) ramified microglia. These results suggest that myelin-specific T cells stimulate lesion-reactive microglial-like cells to produce IL-1β. These findings are relevant to understand the consequences of T-cell infiltration in white and gray matter lesions in patients with MS. GLIA...

  1. A novel pleiotropic effect of aspirin: Beneficial regulation of pro- and anti-inflammatory mechanisms in microglial cells.

    Science.gov (United States)

    Kata, Diana; Földesi, Imre; Feher, Liliana Z; Hackler, Laszlo; Puskas, Laszlo G; Gulya, Karoly

    2017-06-01

    Aspirin, one of the most widely used non-steroidal anti-inflammatory drugs, has extensively studied effects on the cardiovascular system. To reveal further pleiotropic, beneficial effects of aspirin on a number of pro- and anti-inflammatory microglial mechanisms, we performed morphometric and functional studies relating to phagocytosis, pro- and anti-inflammatory cytokine production (IL-1β, tumor necrosis factor-α (TNF-α) and IL-10, respectively) and analyzed the expression of a number of inflammation-related genes, including those related to the above functions, in pure microglial cells. We examined the effects of aspirin (0.1mM and 1mM) in unchallenged (control) and bacterial lipopolysaccharide (LPS)-challenged secondary microglial cultures. Aspirin affected microglial morphology and functions in a dose-dependent manner as it inhibited LPS-elicited microglial activation by promoting ramification and the inhibition of phagocytosis in both concentrations. Remarkably, aspirin strongly reduced the pro-inflammatory IL-1β and TNF-α production, while it increased the anti-inflammatory IL-10 level in LPS-challenged cells. Moreover, aspirin differentially regulated the expression of a number of inflammation-related genes as it downregulated such pro-inflammatory genes as Nos2, Kng1, IL1β, Ptgs2 or Ccr1, while it upregulated some anti-inflammatory genes such as IL10, Csf2, Cxcl1, Ccl5 or Tgfb1. Thus, the use of aspirin could be beneficial for the prophylaxis of certain neurodegenerative disorders as it effectively ameliorates inflammation in the brain. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Vaccinium bracteatum Thunb. Exerts Anti-Inflammatory Activity by Inhibiting NF-?B Activation in BV-2 Microglial Cells

    OpenAIRE

    Kwon, Seung-Hwan; Ma, Shi-Xun; Ko, Yong-Hyun; Seo, Jee-Yeon; Lee, Bo-Ram; Lee, Taek Hwan; Kim, Sun Yeou; Lee, Seok-Yong; Jang, Choon-Gon

    2016-01-01

    This study was designed to evaluate the pharmacological effects of Vaccinium bracteatum Thunb. methanol extract (VBME) on microglial activation and to identify the underlying mechanisms of action of these effects. The anti-inflammatory properties of VBME were studied using lipopolysaccharide (LPS)-stimulated BV-2 microglial cells. We measured the production of nitric oxide (NO), inducible NO synthase (iNOS), cyclooxygenase (COX)-2, prostaglandin E2 (PGE2), tumor necrosis factor-alpha (TNF-?),...

  3. Deciphering resting microglial morphology and process motility from a synaptic prospect

    Directory of Open Access Journals (Sweden)

    Ines eHristovska

    2016-01-01

    Full Text Available Microglia, the resident immune cells of the central nervous system (CNS, were traditionally believed to be set into action only in case of injury or disease. Accordingly, microglia were assumed to be inactive or resting in the healthy brain. However, recent studies revealed that microglia carry out active tissue sampling in the intact brain by extending and retracting their ramified processes while periodically contacting synapses. Microglial morphology and motility as well as the frequency and duration of physical contacts with synaptic elements were found to be modulated by neuronal activity, sensory experience and neurotransmission; however findings have not been straightforward. Microglial cells are the most morphologically plastic element of the CNS. This unique feature confers them the possibility to locally sense activity, and to respond adequately by establishing synaptic contacts to regulate synaptic inputs by the secretion of signaling molecules. Indeed, microglial cells can hold new roles as critical players in maintaining brain homeostasis and regulating synaptic number, maturation and plasticity. For this reason, a better characterization of microglial cells and cues mediating neuron-to-microglia communication under physiological conditions may help advance our understanding of the microglial behavior and its regulation in the healthy brain. This review highlights recent findings on the instructive role of neuronal activity on microglial motility and microglia-synapse interactions, focusing on the main transmitters involved in this communication and including newly described communication at the tripartite synapse.

  4. Regulatory Effects of Fisetin on Microglial Activation

    OpenAIRE

    Chuang, Jing-Yuan; Chang, Pei-Chun; Shen, Yi-Chun; Lin, Chingju; Tsai, Cheng-Fang; Chen, Jia-Hong; Yeh, Wei-Lan; Wu, Ling-Hsuan; Lin, Hsiao-Yun; Liu, Yu-Shu; Lu, Dah-Yuu

    2014-01-01

    Increasing evidence suggests that inflammatory processes in the central nervous system that are mediated by microglial activation play a key role in neurodegeneration. Fisetin, a plant flavonol commonly found in fruits and vegetables, is frequently added to nutritional supplements due to its antioxidant properties. In the present study, treatment with fisetin inhibited microglial cell migration and ROS (reactive oxygen species) production. Treatment with fisetin also effectively inhibited LPS...

  5. Neuroimmune regulation of microglial activity involved in neuroinflammation and neurodegenerative diseases.

    Science.gov (United States)

    González, Hugo; Elgueta, Daniela; Montoya, Andro; Pacheco, Rodrigo

    2014-09-15

    Neuroinflammation constitutes a fundamental process involved in the progression of several neurodegenerative disorders, such as Parkinson's disease, Alzheimer's disease, amyotrophic lateral sclerosis and multiple sclerosis. Microglial cells play a central role in neuroinflammation, promoting neuroprotective or neurotoxic microenvironments, thus controlling neuronal fate. Acquisition of different microglial functions is regulated by intercellular interactions with neurons, astrocytes, the blood-brain barrier, and T-cells infiltrating the central nervous system. In this study, an overview of the regulation of microglial function mediated by different intercellular communications is summarised and discussed. Afterward, we focus in T-cell-mediated regulation of neuroinflammation involved in neurodegenerative disorders. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Axonal lesion-induced microglial proliferation and microglial cluster formation in the mouse

    DEFF Research Database (Denmark)

    Dissing-Olesen, L; Ladeby, R; Nielsen, Helle Hvilsted

    2007-01-01

    Microglia are innate immune cells and form the first line of defense of the CNS. Proliferation is a key event in the activation of microglia in acute pathology, and has been extensively characterized in rats, but not in mice. In this study we investigated axonal-lesion-induced microglial prolifer...

  7. Herpes simplex virus induces neural oxidative damage via microglial cell Toll-like receptor-2

    Directory of Open Access Journals (Sweden)

    Little Morgan R

    2010-06-01

    Full Text Available Abstract Background Using a murine model of herpes simplex virus (HSV-1 encephalitis, our laboratory has determined that induction of proinflammatory mediators in response to viral infection is largely mediated through a Toll-like receptor-2 (TLR2-dependent mechanism. Published studies have shown that, like other inflammatory mediators, reactive oxygen species (ROS are generated during viral brain infection. It is increasingly clear that ROS are responsible for facilitating secondary tissue damage during central nervous system infection and may contribute to neurotoxicity associated with herpes encephalitis. Methods Purified microglial cell and mixed neural cell cultures were prepared from C57B/6 and TLR2-/- mice. Intracellular ROS production in cultured murine microglia was measured via 2', 7'-Dichlorofluorescin diacetate (DCFH-DA oxidation. An assay for 8-isoprostane, a marker of lipid peroxidation, was utilized to measure free radical-associated cellular damage. Mixed neural cultures obtained from β-actin promoter-luciferase transgenic mice were used to detect neurotoxicity induced by HSV-infected microglia. Results Stimulation with HSV-1 elevated intracellular ROS in wild-type microglial cell cultures, while TLR2-/- microglia displayed delayed and attenuated ROS production following viral infection. HSV-infected TLR2-/- microglia produced less neuronal oxidative damage to mixed neural cell cultures in comparison to HSV-infected wild-type microglia. Further, HSV-infected TLR2-/- microglia were found to be less cytotoxic to cultured neurons compared to HSV-infected wild-type microglia. These effects were associated with decreased activation of p38 MAPK and p42/p44 ERK in TLR2-/- mice. Conclusions These studies demonstrate the importance of microglial cell TLR2 in inducing oxidative stress and neuronal damage in response to viral infection.

  8. Microglial cell dysregulation in Brain Aging and Neurodegeneration.

    Directory of Open Access Journals (Sweden)

    Rommy eVon Bernhardi

    2015-07-01

    Full Text Available Aging is the main risk factor for neurodegenerative diseases. In aging, microglia undergo phenotypic changes compatible with their activation. Glial activation can lead to neuroinflammation, which is increasingly accepted as part of the pathogenesis of neurodegenerative diseases, including Alzheimer’s disease (AD. We hypothesize that in aging, aberrant microglia activation leads to a deleterious environment and neurodegeneration. In aged mice, microglia exhibit an increased expression of cytokines and an exacerbated inflammatory response to pathological changes. Whereas LPS increases nitric oxide secretion in microglia from young mice, induction of reactive oxygen species (ROS predominates in older mice. Furthermore, there is accumulation of DNA oxidative damage in mitochondria of microglia during aging, and also an increased intracellular ROS production. Increased ROS activates the redox-sensitive nuclear factor kappa B, which promotes more neuroinflammation, and can be translated in functional deficits, such as cognitive impairment. Mitochondria-derived ROS and cathepsin B, are also necessary for the microglial cell production of interleukin-1β, a key inflammatory cytokine. Interestingly, whereas the regulatory cytokine TGFβ1 is also increased in the aged brain, neuroinflammation persists. Assessing this apparent contradiction, we have reported that TGFβ1 induction and activation of Smad3 signaling after inflammatory stimulation are reduced in adult mice. Other protective functions, such as phagocytosis, although observed in aged animals, become not inducible by inflammatory stimuli and TGFβ1. Here, we discuss data suggesting that mitochondrial and endolysosomal dysfunction could at least partially mediate age-associated microglial cell changes, and, together with the impairment of the TGFβ1-Smad3 pathway, could result in a reduction of protective activation and a facilitation of cytotoxic activation of microglia, resulting in the

  9. Microglial involvement in neuroplastic changes following focal brain ischemia in rats.

    Directory of Open Access Journals (Sweden)

    Alexandre Madinier

    2009-12-01

    Full Text Available The pathogenesis of ischemic stroke is a complex sequence of events including inflammatory reaction, for which the microglia appears to be a major cellular contributor. However, whether post-ischemic activation of microglial cells has beneficial or detrimental effects remains to be elucidated, in particular on long term brain plasticity events. The objective of our study was to determine, through modulation of post-stroke inflammatory response, to what extent microglial cells are involved in some specific events of neuronal plasticity, neurite outgrowth and synaptogenesis. Since microglia is a source of neurotrophic factors, the identification of the brain-derived neurophic factor (BDNF as possible molecular actor involved in these events was also attempted. As a means of down-regulating the microglial response induced by ischemia, 3-aminobenzamide (3-AB, 90 mg/kg, i.p. was used to inhibit the poly(ADP-ribose polymerase-1 (PARP-1. Indeed, PARP-1 contributes to the activation of the transcription factor NF-kB, which is essential to the upregulation of proinflammatory genes, in particular responsible for microglial activation/proliferation. Experiments were conducted in rats subjected to photothrombotic ischemia which leads to a strong and early microglial cells activation/proliferation followed by an infiltration of macrophages within the cortical lesion, events evaluated at serial time points up to 1 month post-ictus by immunostaining for OX-42 and ED-1. Our most striking finding was that the decrease in acute microglial activation induced by 3-AB was associated with a long term down-regulation of two neuronal plasticity proteins expression, synaptophysin (marker of synaptogenesis and GAP-43 (marker of neuritogenesis as well as to a significant decrease in tissue BDNF production. Thus, our data argue in favour of a supportive role for microglia in brain neuroplasticity stimulation possibly through BDNF production, suggesting that a targeted

  10. stimulated BV2 Microglial

    African Journals Online (AJOL)

    2012-03-26

    Mar 26, 2012 ... 2), in LPS-stimulated BV2 microglial cells. The level of NO production was analyzed using Griess reaction. The release of PGE2 was determined using sandwich enzyme-linked immunosorbent assay. The DNA-binding activity of nuclear factor-κB (NF-κB) was measured by electrophoretic mobility shift assay ...

  11. Epigallocatechin gallate protects dopaminergic neurons against 1-methyl-4- phenyl-1,2,3,6-tetrahydropyridine-induced neurotoxicity by inhibiting microglial cell activation.

    Science.gov (United States)

    Li, Rui; Peng, Ning; Du, Fang; Li, Xu-ping; Le, Wei-dong

    2006-04-01

    To observe whether the dopaminergic neuroprotective effect of (-)-epigallocatechin gallate (EGCG) is associated with its inhibition of microglial cell activation in vivo. The effects of EGCG at different doses on dopaminergic neuronal survival were tested in a methyl-4-phenyl-pyridinium (MPP+)-induced dopaminergic neuronal injury model in the primary mesencephalic cell cultures. With unbiased stereological method, tyrosine hydroxylase-immunoreactive (TH-ir) cells were counted in the A8, A9 and A10 regions of the substantia nigra (SN) in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated C57BL/6 mice. The effect of EGCG on microglial activation in the SN was also investigated. Pretreatment with EGCG (1 to 100 micromol/L) significantly attenuated MPP+-induced TH-ir cell loss by 22.2% to 80.5% in the mesencephalic cell cultures. In MPTP-treated C57BL/6 mice, EGCG at a low concentration (1 mg/kg) provided significant protection against MPTP-induced TH-ir cell loss by 50.9% in the whole nigral area and by 71.7% in the A9 region. EGCG at 5 mg/kg showed more prominent protective effect than at 1 or 10 mg/kg. EGCG pretreatment significantly inhibited microglial activation and CD11b expression induced by MPTP. EGCG exerts potent dopaminergic neuroprotective activity by means of microglial inhibition, which shed light on the potential use of EGCG in treatment of Parkinson's disease.

  12. Effects of 3,3',5-triiodothyronine on microglial functions.

    Science.gov (United States)

    Mori, Yuki; Tomonaga, Daichi; Kalashnikova, Anastasia; Furuya, Fumihiko; Akimoto, Nozomi; Ifuku, Masataka; Okuno, Yuko; Beppu, Kaoru; Fujita, Kyota; Katafuchi, Toshihiko; Shimura, Hiroki; Churilov, Leonid P; Noda, Mami

    2015-05-01

    L-tri-iodothyronine (3, 3', 5-triiodothyronine; T3) is an active form of the thyroid hormone (TH) essential for the development and function of the CNS. Though nongenomic effect of TH, its plasma membrane-bound receptor, and its signaling has been identified, precise function in each cell type of the CNS remained to be investigated. Clearance of cell debris and apoptotic cells by microglia phagocytosis is a critical step for the restoration of damaged neuron-glia networks. Here we report nongenomic effects of T3 on microglial functions. Exposure to T3 increased migration, membrane ruffling and phagocytosis of primary cultured mouse microglia. Injection of T3 together with stab wound attracted more microglia to the lesion site in vivo. Blocking TH transporters and receptors (TRs) or TRα-knock-out (KO) suppressed T3-induced microglial migration and morphological change. The T3-induced microglial migration or membrane ruffling was attenuated by inhibiting Gi /o -protein as well as NO synthase, and subsequent signaling such as phosphoinositide 3-kinase (PI3K), mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK). Inhibitors for Na(+) /K(+) -ATPase, reverse mode of Na(+) /Ca(2+) exchanger (NCX), and small-conductance Ca(2+) -dependent K(+) (SK) channel also attenuated microglial migration or phagocytosis. Interestingly, T3-induced microglial migration, but not phagocytosis, was dependent on GABAA and GABAB receptors, though GABA itself did not affect migratory aptitude. Our results demonstrate that T3 modulates multiple functional responses of microglia via multiple complex mechanisms, which may contribute to physiological and/or pathophysiological functions of the CNS. © 2015 Wiley Periodicals, Inc.

  13. Dystrophic (senescent) rather than activated microglial cells are associated with tau pathology and likely precede neurodegeneration in Alzheimer?s disease

    OpenAIRE

    Streit, Wolfgang J.; Braak, Heiko; Xue, Qing-Shan; Bechmann, Ingo

    2009-01-01

    The role of microglial cells in the pathogenesis of Alzheimer’s disease (AD) neurodegeneration is unknown. Although several works suggest that chronic neuroinflammation caused by activated microglia contributes to neurofibrillary degeneration, anti-inflammatory drugs do not prevent or reverse neuronal tau pathology. This raises the question if indeed microglial activation occurs in the human brain at sites of neurofibrillary degeneration. In view of the recent work demonstrating presence of d...

  14. Poly(ADP-ribosepolymerase-1 modulates microglial responses to amyloid β

    Directory of Open Access Journals (Sweden)

    Kauppinen Tiina M

    2011-11-01

    Full Text Available Abstract Background Amyloid β (Aβ accumulates in Alzheimer's disease (AD brain. Microglial activation also occurs in AD, and this inflammatory response may contribute to disease progression. Microglial activation can be induced by Aβ, but the mechanisms by which this occurs have not been defined. The nuclear enzyme poly(ADP-ribose polymerase-1 (PARP-1 regulates microglial activation in response to several stimuli through its interactions with the transcription factor, NF-κB. The purpose of this study was to evaluate whether PARP-1 activation is involved in Aβ-induced microglial activation, and whether PARP-1 inhibition can modify microglial responses to Aβ. Methods hAPPJ20 mice, which accumulate Aβ with ageing, were crossed with PARP-1-/- mice to assess the effects of PARP-1 depletion on microglial activation, hippocampal synaptic integrity, and cognitive function. Aβ peptide was also injected into brain of wt and PARP-1-/- mice to directly determine the effects of PARP-1 on Aβ-induced microglial activation. The effect of PARP-1 on Aβ-induced microglial cytokine production and neurotoxicity was evaluated in primary microglia cultures and in microglia-neuron co-cultures, utilizing PARP-1-/- cells and a PARP-1 inhibitor. NF-κB activation was evaluated in microglia infected with a lentivirus reporter gene. Results The hAPPJ20 mice developed microglial activation, reduced hippocampal CA1 calbindin expression, and impaired novel object recognition by age 6 months. All of these features were attenuated in hAPPJ20/PARP-1-/- mice. Similarly, Aβ1-42 injected into mouse brain produced a robust microglial response in wild-type mice, and this was blocked in mice lacking PARP-1 expression or activity. Studies using microglial cultures showed that PARP-1 activity was required for Aβ-induced NF-κB activation, morphological transformation, NO release, TNFα release, and neurotoxicity. Conversely, PARP-1 inhibition increased release of the

  15. P2X7 receptor mediates activation of microglial cells in prostate of chemically irritated rats

    Directory of Open Access Journals (Sweden)

    Heng Zhang

    2013-04-01

    Full Text Available Purpose Evidence shows that adenosine triphosphate (ATP is involved in the transmission of multiple chronic pain via P2X7 receptor. This study was to investigate the P2X7 and microglial cells in the chronic prostatitis pain. Materials and Methods Rats were divided into control group and chronic prostatitis group (n = 24 per group. A chronic prostatitis animal model was established by injecting complete Freund's adjuvant (CFA to the prostate of rats, and the thermal withdrawal latency (TWL was detected on days 0, 4, 12 and 24 (n = 6 at each time point in each group. Animals were sacrificed and the pathological examination of the prostate, detection of mRNA expression of P2X7 and ionized calcium binding adaptor molecule 1 (IBA-1 and measurement of content of tumor necrosis factor-α (TNF-α and interleukin-1β (IL-1β in the dorsal horn of L5-S2 spinal cord were performed on days 0, 4, 12 and 24. In addition, the content of TNF-α and IL-1β in the dorsal horn of L5-S2 spinal cord was measured after intrathecal injection of inhibitors of microglial cells and/or P2X7 for 5 days. Results The chronic prostatitis was confirmed by pathological examination. The expression of P2X7 and IBA-1 and the content of TNF-α and IL-1β in rats with chronic prostatitis were significantly higher than those in the control group. On day 4, the expressions of pro-inflammatory cytokines became to increase, reaching a maximal level on day 12 and started to reduce on day 24, but remained higher than that in the control group. Following suppression of microglial cells and P2X7 receptor, the secretion of TNF-α and IL-1β was markedly reduced. Conclusion In chronic prostatitis pain, the microglial cells and P2X7 receptor are activated resulting in the increased expression of TNF-α and IL-1β in the L5-S2 spinal cord, which might attribute to the maintenance and intensification of pain in chronic prostatitis.

  16. Microglial dystrophy in the aged and Alzheimer's disease brain is associated with ferritin immunoreactivity.

    Science.gov (United States)

    Lopes, Kryslaine O; Sparks, D Larry; Streit, Wolfgang J

    2008-08-01

    Degeneration of microglial cells may be important for understanding the pathogenesis of aging-related neurodegeneration and neurodegenerative diseases. In this study, we analyzed the morphological characteristics of microglial cells in the nondemented and Alzheimer's disease (AD) human brain using ferritin immunohistochemistry. The central hypothesis was that expression of the iron storage protein ferritin increases the susceptibility of microglia to degeneration, particularly in the aged brain since senescent microglia might become less efficient in maintaining iron homeostasis and free iron can promote oxidative damage. In a primary set of 24 subjects (age range 34-97 years) examined, microglial cells immunoreactive for ferritin were found to constitute a subpopulation of the larger microglial pool labeled with an antibody for HLA-DR antigens. The majority of these ferritin-positive microglia exhibited aberrant morphological (dystrophic) changes in the aged and particularly in the AD brain. No spatial correlation was found between ferritin-positive dystrophic microglia and senile plaques in AD tissues. Analysis of a secondary set of human postmortem brain tissues with a wide range of postmortem intervals (PMI, average 10.94 +/- 5.69 h) showed that the occurrence of microglial dystrophy was independent of PMI and consequently not a product of tissue autolysis. Collectively, these results suggest that microglial involvement in iron storage and metabolism contributes to their degeneration, possibly through increased exposure of the cells to oxidative stress. We conclude that ferritin immunohistochemistry may be a useful method for detecting degenerating microglia in the human brain. (c) 2008 Wiley-Liss, Inc.

  17. Regulatory Effects of Caffeic Acid Phenethyl Ester on Neuroinflammation in Microglial Cells

    Directory of Open Access Journals (Sweden)

    Cheng-Fang Tsai

    2015-03-01

    Full Text Available Microglial activation has been widely demonstrated to mediate inflammatory processes that are crucial in several neurodegenerative disorders. Pharmaceuticals that can deliver direct inhibitory effects on microglia are therefore considered as a potential strategy to counter balance neurodegenerative progression. Caffeic acid phenethyl ester (CAPE, a natural phenol in honeybee propolis, is known to possess antioxidant, anti-inflammatory and anti-microbial properties. Accordingly, the current study intended to probe the effects of CAPE on microglia activation by using in vitro and in vivo models. Western blot and Griess reaction assay revealed CAPE significantly inhibited the expressions of inducible nitric oxide synthase (NOS, cyclooxygenase (COX-2 and the production of nitric oxide (NO. Administration of CAPE resulted in increased expressions of hemeoxygenase (HO-1and erythropoietin (EPO in microglia. The phosphorylated adenosine monophosphate-activated protein kinase (AMPK-α was further found to regulate the anti-inflammatory effects of caffeic acid. In vivo results from immunohistochemistry along with rotarod test also revealed the anti-neuroinflammatory effects of CAPE in microglia activation. The current study has evidenced several possible molecular determinants, AMPKα, EPO, and HO-1, in mediating anti-neuroinflammatory responses in microglial cells.

  18. Protective Effect of Cactus Cladode Extracts on Peroxisomal Functions in Microglial BV-2 Cells Activated by Different Lipopolysaccharides.

    Science.gov (United States)

    Saih, Fatima-Ezzahra; Andreoletti, Pierre; Mandard, Stéphane; Latruffe, Norbert; El Kebbaj, M'Hammed Saïd; Lizard, Gérard; Nasser, Boubker; Cherkaoui-Malki, Mustapha

    2017-01-07

    In this study, we aimed to evaluate the antioxidant and anti-inflammatory properties of Opuntia ficus-indica cactus cladode extracts in microglia BV-2 cells. Inflammation associated with microglia activation in neuronal injury can be achieved by LPS exposure. Using four different structurally and biologically well-characterized LPS serotypes, we revealed a structure-related differential effect of LPS on fatty acid β-oxidation and antioxidant enzymes in peroxisomes: Escherichia coli -LPS decreased ACOX1 activity while Salmonella minnesota -LPS reduced only catalase activity. Different cactus cladode extracts showed an antioxidant effect through microglial catalase activity activation and an anti-inflammatory effect by reducing nitric oxide (NO) LPS-dependent production. These results suggest that cactus extracts may possess a neuroprotective activity through the induction of peroxisomal antioxidant activity and the inhibition of NO production by activated microglial cells.

  19. Protective Effect of Cactus Cladode Extracts on Peroxisomal Functions in Microglial BV-2 Cells Activated by Different Lipopolysaccharides

    Directory of Open Access Journals (Sweden)

    Fatima-Ezzahra Saih

    2017-01-01

    Full Text Available In this study, we aimed to evaluate the antioxidant and anti-inflammatory properties of Opuntia ficus-indica cactus cladode extracts in microglia BV-2 cells. Inflammation associated with microglia activation in neuronal injury can be achieved by LPS exposure. Using four different structurally and biologically well-characterized LPS serotypes, we revealed a structure-related differential effect of LPS on fatty acid β-oxidation and antioxidant enzymes in peroxisomes: Escherichia coli-LPS decreased ACOX1 activity while Salmonella minnesota-LPS reduced only catalase activity. Different cactus cladode extracts showed an antioxidant effect through microglial catalase activity activation and an anti-inflammatory effect by reducing nitric oxide (NO LPS-dependent production. These results suggest that cactus extracts may possess a neuroprotective activity through the induction of peroxisomal antioxidant activity and the inhibition of NO production by activated microglial cells.

  20. Fingolimod modulates microglial activation to augment markers of remyelination

    Directory of Open Access Journals (Sweden)

    Baker David

    2011-07-01

    Full Text Available Abstract Introduction Microglial activation in multiple sclerosis has been postulated to contribute to long-term neurodegeneration during disease. Fingolimod has been shown to impact on the relapsing remitting phase of disease by modulating autoreactive T-cell egress from lymph organs. In addition, it is brain penetrant and has been shown to exert multiple effects on nervous system cells. Methods In this study, the impact of fingolimod and other sphingosine-1-phosphate receptor active molecules following lysophosphotidyl choline-induced demyelination was examined in the rat telencephalon reaggregate, spheroid cell culture system. The lack of immune system components allowed elucidation of the direct effects of fingolimod on CNS cell types in an organotypic situation. Results Following demyelination, fingolimod significantly augmented expression of myelin basic protein in the remyelination phase. This increase was not associated with changes in neurofilament levels, indicating de novo myelin protein expression not associated with axonal branching. Myelin wrapping was confirmed morphologically using confocal and electron microscopy. Increased remyelination was associated with down-regulation of microglial ferritin, tumor necrosis factor alpha and interleukin 1 during demyelination when fingolimod was present. In addition, nitric oxide metabolites and apoptotic effectors caspase 3 and caspase 7 were reduced during demyelination in the presence of fingolimod. The sphingosine-1-phosphate receptor 1 and 5 agonist BAF312 also increased myelin basic protein levels, whereas the sphingosine-1-phosphate receptor 1 agonist AUY954 failed to replicate this effect on remyelination. Conclusions The results presented indicate that modulation of S1P receptors can ameliorate pathological effectors associated with microglial activation leading to a subsequent increase in protein and morphological markers of remyelination. In addition, sphingosine-1-phosphate

  1. Astrocyte galectin-9 potentiates microglial TNF secretion.

    Science.gov (United States)

    Steelman, Andrew J; Li, Jianrong

    2014-08-27

    Aberrant neuroinflammation is suspected to contribute to the pathogenesis of myriad neurological diseases. As such, determining the pathways that promote or inhibit glial activation is of interest. Activation of the surface glycoprotein T-cell immunoglobulin and mucin-domain containing protein 3 (Tim-3) by the lectin galectin-9 has been implicated in promoting innate immune cell activation by potentiating or synergizing toll-like receptor (TLR) signaling. In the present study we examined the role of the Tim-3/galectin-9 pathway in glial activation in vitro. Primary monocultures of microglia or astrocytes, co-cultures containing microglia and astrocytes, and mixed glial cultures consisting of microglia, astrocytes and oligodendrocytes were stimulated with poly(I:C) or LPS, and galectin-9 up-regulation was determined. The effect of endogenous galectin-9 production on microglial activation was examined using cultures from wild-type and Lgals9 null mice. The ability for recombinant galectin-9 to promote microglia activation was also assessed. Tim-3 expression on microglia and BV2 cells was examined by qPCR and flow cytometry and its necessity in transducing the galectin-9 signal was determined using a Tim-3 specific neutralizing antibody or recombinant soluble Tim-3. Astrocytes potentiated TNF production from microglia following TLR stimulation. Poly(I:C) stimulation increased galectin-9 expression in microglia and microglial-derived factors promoted galectin-9 up-regulation in astrocytes. Astrocyte-derived galectin-9 in turn enhanced microglial TNF production. Similarly, recombinant galectin-9 enhanced poly(I:C)-induced microglial TNF and IL-6 production. Inhibition of Tim-3 did not alter TNF production in mixed glial cultures stimulated with poly(I:C). Galectin-9 functions as an astrocyte-microglia communication signal and promotes cytokine production from microglia in a Tim-3 independent manner. Activation of CNS galectin-9 likely modulates neuroinflammatory

  2. Microglial AGE-albumin is critical for neuronal death in Parkinson's disease: a possible implication for theranostics.

    Science.gov (United States)

    Bayarsaikhan, Enkhjargal; Bayarsaikhan, Delger; Lee, Jaesuk; Son, Myeongjoo; Oh, Seyeon; Moon, Jeongsik; Park, Hye-Jeong; Roshini, Arivazhagan; Kim, Seung U; Song, Byoung-Joon; Jo, Seung-Mook; Byun, Kyunghee; Lee, Bonghee

    2015-01-01

    Advanced glycation end products (AGEs) are known to play an important role in the pathogenesis of neurodegenerative diseases, including Parkinson's disease (PD), by inducing protein aggregation and cross-link, formation of Lewy body, and neuronal death. In this study, we observed that AGE-albumin, the most abundant AGE product in the human PD brain, is synthesized in activated microglial cells and accumulates in the extracellular space. AGE-albumin synthesis in human-activated microglial cells is distinctly inhibited by ascorbic acid and cytochalasin treatment. Accumulated AGE-albumin upregulates the receptor to AGE, leading to apoptosis of human primary dopamine (DA) neurons. In animal experiments, we observed reduced DA neuronal cell death by treatment with soluble receptor to AGE. Our study provides evidence that activated microglial cells are one of the main contributors in AGE-albumin accumulation, deleterious to DA neurons in human and animal PD brains. Finally, activated microglial AGE-albumin could be used as a diagnostic and therapeutic biomarker with high sensitivity for neurodegenerative disorders, including PD.

  3. A new synthetic chalcone derivative, 2-hydroxy-3',5,5'-trimethoxychalcone (DK-139), suppresses the Toll-like receptor 4-mediated inflammatory response through inhibition of the Akt/NF-κB pathway in BV2 microglial cells.

    Science.gov (United States)

    Lee, Young Han; Jeon, Seung-Hyun; Kim, Se Hyun; Kim, Changyoun; Lee, Seung-Jae; Koh, Dongsoo; Lim, Yoongho; Ha, Kyooseob; Shin, Soon Young

    2012-06-30

    Microglial cells are the resident innate immune cells that sense pathogens and tissue injury in the central nervous system (CNS). Microglial activation is critical for neuroinflammatory responses. The synthetic compound 2-hydroxy-3',5,5'-trimethoxychalcone (DK-139) is a novel chalcone-derived compound. In this study, we investigated the effects of DK-139 on Toll-like receptor 4 (TLR4)-mediated inflammatory responses in BV2 microglial cells. DK-139 inhibited lipopolysaccharide (LPS)-induced TLR4 activity, as determined using a cell-based assay. DK-139 blocked LPS-induced phosphorylation of IκB and p65/RelA NF-κB, resulting in inhibition of the nuclear translocation and trans-acting activity of NF-κB in BV2 microglial cells. We also found that DK-139 reduced the expression of NF-κB target genes, such as those for COX-2, iNOS, and IL-1β, in LPS-stimulated BV2 microglial cells. Interestingly, DK-139 blocked LPS-induced Akt phosphorylation. Inhibition of Akt abrogated LPS-induced phosphorylation of p65/RelA, while overexpression of dominant- active p110CAAX enhanced p65/RelA phosphorylation as well as iNOS and COX2 expression. These results suggest that DK-139 exerts an anti-inflammatory effect on microglial cells by inhibiting the Akt/IκB kinase (IKK)/NF-κB signaling pathway.

  4. HIV-1 Myristoylated Nef Treatment of Murine Microglial Cells Activates Inducible Nitric Oxide Synthase, NO2 Production and Neurotoxic Activity.

    Directory of Open Access Journals (Sweden)

    Giorgio Mangino

    Full Text Available The potential role of the human immunodeficiency virus-1 (HIV-1 accessory protein Nef in the pathogenesis of neuroAIDS is still poorly understood. Nef is a molecular adapter that influences several cellular signal transduction events and membrane trafficking. In human macrophages, Nef expression induces the production of extracellular factors (e.g. pro-inflammatory chemokines and cytokines and the recruitment of T cells, thus favoring their infection and its own transfer to uninfected cells via exosomes, cellular protrusions or cell-to-cell contacts. Murine cells are normally not permissive for HIV-1 but, in transgenic mice, Nef is a major disease determinant. Both in human and murine macrophages, myristoylated Nef (myr+Nef treatment has been shown to activate NF-κB, MAP kinases and interferon responsive factor 3 (IRF-3, thereby inducing tyrosine phosphorylation of signal transducers and activator of transcription (STAT-1, STAT-2 and STAT-3 through the production of proinflammatory factors.We report that treatment of BV-2 murine microglial cells with myr+Nef leads to STAT-1, -2 and -3 tyrosine phosphorylation and upregulates the expression of inducible nitric oxide synthase (iNOS with production of nitric oxide. We provide evidence that extracellular Nef regulates iNOS expression through NF-κB activation and, at least in part, interferon-β (IFNβ release that acts in concert with Nef. All of these effects require both myristoylation and a highly conserved acidic cluster in the viral protein. Finally, we report that Nef induces the release of neurotoxic factors in the supernatants of microglial cells.These results suggest a potential role of extracellular Nef in promoting neuronal injury in the murine model. They also indicate a possible interplay between Nef and host factors in the pathogenesis of neuroAIDS through the production of reactive nitrogen species in microglial cells.

  5. Large A-fiber activity is required for microglial proliferation and p38 MAPK activation in the spinal cord: different effects of resiniferatoxin and bupivacaine on spinal microglial changes after spared nerve injury

    Directory of Open Access Journals (Sweden)

    Decosterd Isabelle

    2009-09-01

    Full Text Available Abstract Background After peripheral nerve injury, spontaneous ectopic activity arising from the peripheral axons plays an important role in inducing central sensitization and neuropathic pain. Recent evidence indicates that activation of spinal cord microglia also contributes to the development of neuropathic pain. In particular, activation of p38 mitogen-activated protein kinase (MAPK in spinal microglia is required for the development of mechanical allodynia. However, activity-dependent activation of microglia after nerve injury has not been fully addressed. To determine whether spontaneous activity from C- or A-fibers is required for microglial activation, we used resiniferatoxin (RTX to block the conduction of transient receptor potential vanilloid subtype 1 (TRPV1 positive fibers (mostly C- and Aδ-fibers and bupivacaine microspheres to block all fibers of the sciatic nerve in rats before spared nerve injury (SNI, and observed spinal microglial changes 2 days later. Results SNI induced robust mechanical allodynia and p38 activation in spinal microglia. SNI also induced marked cell proliferation in the spinal cord, and all the proliferating cells (BrdU+ were microglia (Iba1+. Bupivacaine induced a complete sensory and motor blockade and also significantly inhibited p38 activation and microglial proliferation in the spinal cord. In contrast, and although it produced an efficient nociceptive block, RTX failed to inhibit p38 activation and microglial proliferation in the spinal cord. Conclusion (1 Blocking peripheral input in TRPV1-positive fibers (presumably C-fibers is not enough to prevent nerve injury-induced spinal microglial activation. (2 Peripheral input from large myelinated fibers is important for microglial activation. (3 Microglial activation is associated with mechanical allodynia.

  6. Microglial cells (BV-2) internalize titanium dioxide (TiO2) nanoparticles: toxicity and cellular responses.

    Science.gov (United States)

    Rihane, Naima; Nury, Thomas; M'rad, Imen; El Mir, Lassaad; Sakly, Mohsen; Amara, Salem; Lizard, Gérard

    2016-05-01

    Because of their whitening and photocatalytic effects, titanium dioxide nanoparticles (TiO2-NPs) are widely used in daily life. These NPs can be found in paints, plastics, papers, sunscreens, foods, medicines (pills), toothpastes, and cosmetics. However, the biological effect of TiO2-NPs on the human body, especially on the central nervous system, is still unclear. Many studies have demonstrated that the brain is one of the target organs in acute or chronic TiO2-NPs toxicity. The present study aimed to investigate the effect of TiO2-NPs at different concentrations (0.1 to 200 μg/mL) on murine microglial cells (BV-2) to assess their activity on cell growth and viability, as well as their neurotoxicity. Different parameters were measured: cell viability, cell proliferation and DNA content (SubG1 peak), mitochondrial depolarization, overproduction of reactive oxygen species (especially superoxide anions), and ultrastructural changes. Results showed that TiO2-NPs induced some cytotoxic effects with a slight inhibition of cell growth. Thus, at high concentrations, TiO2-NPs were not only able to inhibit cell adhesion but also enhanced cytoplasmic membrane permeability to propidium iodide associated with a loss of mitochondrial transmembrane potential and an overproduction of superoxide anions. No induction of apoptosis based on the presence of a SubG1 peak was detected. The microscopic observations also indicated that small groups of nanosized particles and micron-sized aggregates were engulfed by the BV-2 cells and sequestered as intracytoplasmic aggregates after 24-h exposure to TiO2-NPs. Altogether, our data show that the accumulation TiO2-NPs in microglial BV-2 cells favors mitochondrial dysfunctions and oxidative stress.

  7. Microglial Dysregulation in OCD, Tourette Syndrome, and PANDAS

    Directory of Open Access Journals (Sweden)

    Luciana Frick

    2016-01-01

    Full Text Available There is accumulating evidence that immune dysregulation contributes to the pathophysiology of obsessive-compulsive disorder (OCD, Tourette syndrome, and Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS. The mechanistic details of this pathophysiology, however, remain unclear. Here we focus on one particular component of the immune system: microglia, the brain’s resident immune cells. The role of microglia in neurodegenerative diseases has been understood in terms of classic, inflammatory activation, which may be both a consequence and a cause of neuronal damage. In OCD and Tourette syndrome, which are not characterized by frank neural degeneration, the potential role of microglial dysregulation is much less clear. Here we review the evidence for a neuroinflammatory etiology and microglial dysregulation in OCD, Tourette syndrome, and PANDAS. We also explore new hypotheses as to the potential contributions of microglial abnormalities to pathophysiology, beyond neuroinflammation, including failures in neuroprotection, lack of support for neuronal survival, and abnormalities in synaptic pruning. Recent advances in neuroimaging and animal model work are creating new opportunities to elucidate these issues.

  8. Microglial Dysregulation in OCD, Tourette Syndrome, and PANDAS

    Science.gov (United States)

    2016-01-01

    There is accumulating evidence that immune dysregulation contributes to the pathophysiology of obsessive-compulsive disorder (OCD), Tourette syndrome, and Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS). The mechanistic details of this pathophysiology, however, remain unclear. Here we focus on one particular component of the immune system: microglia, the brain's resident immune cells. The role of microglia in neurodegenerative diseases has been understood in terms of classic, inflammatory activation, which may be both a consequence and a cause of neuronal damage. In OCD and Tourette syndrome, which are not characterized by frank neural degeneration, the potential role of microglial dysregulation is much less clear. Here we review the evidence for a neuroinflammatory etiology and microglial dysregulation in OCD, Tourette syndrome, and PANDAS. We also explore new hypotheses as to the potential contributions of microglial abnormalities to pathophysiology, beyond neuroinflammation, including failures in neuroprotection, lack of support for neuronal survival, and abnormalities in synaptic pruning. Recent advances in neuroimaging and animal model work are creating new opportunities to elucidate these issues. PMID:28053994

  9. Toxoplasma gondii infection shifts dendritic cells into an amoeboid rapid migration mode encompassing podosome dissolution, secretion of TIMP-1, and reduced proteolysis of extracellular matrix.

    Science.gov (United States)

    Ólafsson, Einar B; Varas-Godoy, Manuel; Barragan, Antonio

    2018-03-01

    Dendritic cells (DCs) infected by Toxoplasma gondii rapidly acquire a hypermigratory phenotype that promotes systemic parasite dissemination by a "Trojan horse" mechanism in mice. Recent paradigms of leukocyte migration have identified the amoeboid migration mode of DCs as particularly suited for rapid locomotion in extracellular matrix and tissues. Here, we have developed a microscopy-based high-throughput approach to assess motility and matrix degradation by Toxoplasma-challenged murine and human DCs. DCs challenged with T. gondii exhibited dependency on metalloproteinase activity for hypermotility and transmigration but, strikingly, also dramatically reduced pericellular proteolysis. Toxoplasma-challenged DCs up-regulated expression and secretion of tissue inhibitor of metalloproteinases-1 (TIMP-1) and their supernatants impaired matrix degradation by naïve DCs and by-stander DCs dose dependently. Gene silencing of TIMP-1 by short hairpin RNA restored matrix degradation activity in Toxoplasma-infected DCs. Additionally, dissolution of podosome structures in parasitised DCs coincided with abrogated matrix degradation. Toxoplasma lysates inhibited pericellular proteolysis in a MyD88-dependent fashion whereas abrogated proteolysis persevered in Toxoplasma-infected MyD88-deficient DCs. This indicated that both TLR/MyD88-dependent and TLR/MyD88-independent signalling pathways mediated podosome dissolution and the abrogated matrix degradation. We report that increased TIMP-1 secretion and cytoskeletal rearrangements encompassing podosome dissolution are features of Toxoplasma-induced hypermigration of DCs with an impact on matrix degradation. Jointly, the data highlight how an obligate intracellular parasite orchestrates key regulatory cellular processes consistent with non-proteolytic amoeboid migration of the vehicle cells that facilitate its dissemination. © 2017 John Wiley & Sons Ltd.

  10. Microglial responses to amyloid β peptide opsonization and indomethacin treatment

    Directory of Open Access Journals (Sweden)

    Leonard Brian

    2005-08-01

    Full Text Available Abstract Background Recent studies have suggested that passive or active immunization with anti-amyloid β peptide (Aβ antibodies may enhance microglial clearance of Aβ deposits from the brain. However, in a human clinical trial, several patients developed secondary inflammatory responses in brain that were sufficient to halt the study. Methods We have used an in vitro culture system to model the responses of microglia, derived from rapid autopsies of Alzheimer's disease patients, to Aβ deposits. Results Opsonization of the deposits with anti-Aβ IgG 6E10 enhanced microglial chemotaxis to and phagocytosis of Aβ, as well as exacerbated microglial secretion of the pro-inflammatory cytokines TNF-α and IL-6. Indomethacin, a common nonsteroidal anti-inflammatory drug (NSAID, had no effect on microglial chemotaxis or phagocytosis, but did significantly inhibit the enhanced production of IL-6 after Aβ opsonization. Conclusion These results are consistent with well known, differential NSAID actions on immune cell functions, and suggest that concurrent NSAID administration might serve as a useful adjunct to Aβ immunization, permitting unfettered clearance of Aβ while dampening secondary, inflammation-related adverse events.

  11. Macrophage colony-stimulating factor and its receptor signaling augment glycated albumin-induced retinal microglial inflammation in vitro

    Directory of Open Access Journals (Sweden)

    Jiang Chun H

    2011-01-01

    Full Text Available Abstract Background Microglial activation and the proinflammatory response are controlled by a complex regulatory network. Among the various candidates, macrophage colony-stimulating factor (M-CSF is considered an important cytokine. The up-regulation of M-CSF and its receptor CSF-1R has been reported in brain disease, as well as in diabetic complications; however, the mechanism is unclear. An elevated level of glycated albumin (GA is a characteristic of diabetes; thus, it may be involved in monocyte/macrophage-associated diabetic complications. Results The basal level of expression of M-CSF/CSF-1R was examined in retinal microglial cells in vitro. Immunofluorescence, real-time PCR, immunoprecipitation, and Western blot analyses revealed the up-regulation of CSF-1R in GA-treated microglial cells. We also detected increased expression and release of M-CSF, suggesting that the cytokine is produced by activated microglia via autocrine signaling. Using an enzyme-linked immunosorbent assay, we found that GA affects microglial activation by stimulating the release of tumor necrosis factor-α and interleukin-1β. Furthermore, the neutralization of M-CSF or CSF-1R with antibodies suppressed the proinflammatory response. Conversely, this proinflammatory response was augmented by the administration of M-CSF. Conclusions We conclude that GA induces microglial activation via the release of proinflammatory cytokines, which may contribute to the inflammatory pathogenesis of diabetic retinopathy. The increased microglial expression of M-CSF/CSF-1R not only is a response to microglial activation in diabetic retinopathy but also augments the microglial inflammation responsible for the diabetic microenvironment.

  12. Hirsutine, an indole alkaloid of Uncaria rhynchophylla, inhibits inflammation-mediated neurotoxicity and microglial activation.

    Science.gov (United States)

    Jung, Hwan Yong; Nam, Kyong Nyon; Woo, Byung-Choel; Kim, Kyoo-Pil; Kim, Sung-Ok; Lee, Eunjoo H

    2013-01-01

    Chronic microglial activation endangers neuronal survival through the release of various pro-inflammatory and neurotoxic factors. As such, negative regulators of microglial activation have been considered as potential therapeutic candidates to reduce the risk of neurodegeneration associated with inflammation. Uncaria rhynchophylla (U. rhynchophylla) is a traditional oriental herb that has been used for treatment of disorders of the cardiovascular and central nervous systems. Hirsutine (HS), one of the major indole alkaloids of U. rhynchophylla, has demonstrated neuroprotective potential. The aim of the present study was to examine the efficacy of HS in the repression of inflammation-induced neurotoxicity and microglial cell activation. In organotypic hippocampal slice cultures, HS blocked lipopolysaccharide (LPS)-related hippocampal cell death and production of nitric oxide (NO), prostaglandin (PG) E2 and interleukin-1β. HS was demonstrated to effectively inhibit LPS-induced NO release from cultured rat brain microglia. The compound reduced the LPS-stimulated production of PGE2 and intracellular reactive oxygen species. HS significantly decreased LPS-induced phosphorylation of the mitogen-activated protein kinases and Akt signaling proteins. In conclusion, HS reduces the production of various neurotoxic factors in activated microglial cells and possesses neuroprotective activity in a model of inflammation-induced neurotoxicity.

  13. Atorvastatin prevents age-related and amyloid-β-induced microglial activation by blocking interferon-γ release from natural killer cells in the brain

    Directory of Open Access Journals (Sweden)

    Clarke Rachael

    2011-03-01

    Full Text Available Abstract Background Microglial function is modulated by several factors reflecting the numerous receptors expressed on the cell surface, however endogenous factors which contribute to the age-related increase in microglial activation remain largely unknown. One possible factor which may contribute is interferon-γ (IFNγ. IFNγ has been shown to increase in the aged brain and potently activates microglia, although its endogenous cell source in the brain remains unidentified. Methods Male Wistar rats were used to assess the effect of age and amyloid-β (Aβ on NK cell infiltration into the brain. The effect of the anti-inflammatory compound, atorvastatin was also assessed under these conditions. We measured cytokine and chemokine (IFNγ, IL-2, monocyte chemoattractant protein-1 (MCP-1 and IFNγ-induced protein 10 kDa (IP-10, expression in the brain by appropriate methods. We also looked at NK cell markers, CD161, NKp30 and NKp46 using flow cytometry and western blot. Results Natural killer (NK cells are a major source of IFNγ in the periphery and here we report the presence of CD161+ NKp30+ cells and expression of CD161 and NKp46 in the brain of aged and Aβ-treated rats. Furthermore, we demonstrate that isolated CD161+ cells respond to interleukin-2 (IL-2 by releasing IFNγ. Atorvastatin, the HMG-CoA reductase inhibitor, attenuates the increase in CD161 and NKp46 observed in hippocampus of aged and Aβ-treated rats. This was paralleled by a decrease in IFNγ, markers of microglial activation and the chemokines, MCP-1 and IP-10 which are chemotactic for NK cells. Conclusions We propose that NK cells contribute to the age-related and Aβ-induced neuroinflammatory changes and demonstrate that these changes can be modulated by atorvastatin treatment.

  14. Atorvastatin prevents age-related and amyloid-beta-induced microglial activation by blocking interferon-gamma release from natural killer cells in the brain

    LENUS (Irish Health Repository)

    Lyons, Anthony

    2011-03-31

    Abstract Background Microglial function is modulated by several factors reflecting the numerous receptors expressed on the cell surface, however endogenous factors which contribute to the age-related increase in microglial activation remain largely unknown. One possible factor which may contribute is interferon-γ (IFNγ). IFNγ has been shown to increase in the aged brain and potently activates microglia, although its endogenous cell source in the brain remains unidentified. Methods Male Wistar rats were used to assess the effect of age and amyloid-β (Aβ) on NK cell infiltration into the brain. The effect of the anti-inflammatory compound, atorvastatin was also assessed under these conditions. We measured cytokine and chemokine (IFNγ, IL-2, monocyte chemoattractant protein-1 (MCP-1) and IFNγ-induced protein 10 kDa (IP-10)), expression in the brain by appropriate methods. We also looked at NK cell markers, CD161, NKp30 and NKp46 using flow cytometry and western blot. Results Natural killer (NK) cells are a major source of IFNγ in the periphery and here we report the presence of CD161+ NKp30+ cells and expression of CD161 and NKp46 in the brain of aged and Aβ-treated rats. Furthermore, we demonstrate that isolated CD161+ cells respond to interleukin-2 (IL-2) by releasing IFNγ. Atorvastatin, the HMG-CoA reductase inhibitor, attenuates the increase in CD161 and NKp46 observed in hippocampus of aged and Aβ-treated rats. This was paralleled by a decrease in IFNγ, markers of microglial activation and the chemokines, MCP-1 and IP-10 which are chemotactic for NK cells. Conclusions We propose that NK cells contribute to the age-related and Aβ-induced neuroinflammatory changes and demonstrate that these changes can be modulated by atorvastatin treatment.

  15. WIP regulates persistence of cell migration and ruffle formation in both mesenchymal and amoeboid modes of motility.

    Directory of Open Access Journals (Sweden)

    Inmaculada Banon-Rodriguez

    Full Text Available The spatial distribution of signals downstream from receptor tyrosine kinases (RTKs or G-protein coupled receptors (GPCR regulates fundamental cellular processes that control cell migration and growth. Both pathways rely significantly on actin cytoskeleton reorganization mediated by nucleation-promoting factors such as the WASP-(Wiskott-Aldrich Syndrome Protein family. WIP (WASP Interacting Protein is essential for the formation of a class of polarised actin microdomain, namely dorsal ruffles, downstream of the RTK for PDGF (platelet-derived growth factor but the underlying mechanism is poorly understood. Using lentivirally-reconstituted WIP-deficient murine fibroblasts we define the requirement for WIP interaction with N-WASP (neural WASP and Nck for efficient dorsal ruffle formation and of WIP-Nck binding for fibroblast chemotaxis towards PDGF-AA. The formation of both circular dorsal ruffles in PDGF-AA-stimulated primary fibroblasts and lamellipodia in CXCL13-treated B lymphocytes are also compromised by WIP-deficiency. We provide data to show that a WIP-Nck signalling complex interacts with RTK to promote polarised actin remodelling in fibroblasts and provide the first evidence for WIP involvement in the control of migratory persistence in both mesenchymal (fibroblast and amoeboid (B lymphocytes motility.

  16. A novel method for evaluating microglial activation using ionized calcium-binding adaptor protein-1 staining : cell body to cell size ratio

    NARCIS (Netherlands)

    Hovens, Iris; Nyakas, Csaba; Schoemaker, Regina

    2014-01-01

    Aim: The aim was to validate a newly developed methodology of semi-automatic image analysis to analyze microglial morphology as marker for microglial activation in ionized calcium-binding adaptor protein-1 (IBA-1) stained brain sections. Methods: The novel method was compared to currently used

  17. Two problems in multiphase biological flows: Blood flow and particulate transport in microvascular network, and pseudopod-driven motility of amoeboid cells

    Science.gov (United States)

    Bagchi, Prosenjit

    2016-11-01

    In this talk, two problems in multiphase biological flows will be discussed. The first is the direct numerical simulation of whole blood and drug particulates in microvascular networks. Blood in microcirculation behaves as a dense suspension of heterogeneous cells. The erythrocytes are extremely deformable, while inactivated platelets and leukocytes are nearly rigid. A significant progress has been made in recent years in modeling blood as a dense cellular suspension. However, many of these studies considered the blood flow in simple geometry, e.g., straight tubes of uniform cross-section. In contrast, the architecture of a microvascular network is very complex with bifurcating, merging and winding vessels, posing a further challenge to numerical modeling. We have developed an immersed-boundary-based method that can consider blood cell flow in physiologically realistic and complex microvascular network. In addition to addressing many physiological issues related to network hemodynamics, this tool can be used to optimize the transport properties of drug particulates for effective organ-specific delivery. Our second problem is pseudopod-driven motility as often observed in metastatic cancer cells and other amoeboid cells. We have developed a multiscale hydrodynamic model to simulate such motility. We study the effect of cell stiffness on motility as the former has been considered as a biomarker for metastatic potential. Funded by the National Science Foundation.

  18. Microglial response to Alzheimer's disease is differentially modulated by voluntary wheel running and enriched environments.

    Science.gov (United States)

    Rodríguez, J J; Noristani, H N; Verkhratsky, A

    2015-03-01

    Alzheimer's disease (AD) is an untreatable neurodegenerative disease that deteriorates memory. Increased physical/cognitive activity reduces dementia risk by promoting neuronal and glial response. Although few studies have investigated microglial response in wild-type rodents following exposure to physical/cognitive stimulation, environmental-induced changes of microglia response to AD have been neglected. We investigated effects of running (RUN) and enriched (ENR) environments on numerical density (N v, #/mm(3)) and morphology of microglia in a triple transgenic (3×Tg-AD) mouse model of AD that closely mimics AD pathology in humans. We used immunohistochemical approach to characterise microglial domain by measuring their overall cell surface, volume and somata volume. 3×Tg-AD mice housed in standard control (STD) environment showed significant increase in microglial N v (11.7 %) in CA1 stratum lacunosum moleculare (S.Mol) of the hippocampus at 12 months compared to non-transgenic (non-Tg) animals. Exposure to combined RUN and ENR environments prevented an increase in microglial N v in 3×Tg-AD and reduced microglial numbers to non-Tg control levels. Interestingly, 3×Tg-AD mice housed solely in ENR environment displayed significant decrease in microglial N v in CA1 subfield (9.3 % decrease), stratum oriens (11.5 % decrease) and S.Mol (7.6 % decrease) of the hippocampus compared to 3×Tg-AD mice housed in STD environment. Morphological analysis revealed microglial hypertrophy due to pronounced increase in microglia surface, volume and somata volume (61, 78 and 41 %) in 3×Tg-AD mice housed in RUN (but not in ENR) compared to STD environment. These results indicate that exposure to RUN and ENR environments have differential effects on microglial density and activation-associated changes in microglial morphology.

  19. Lipoprotein Lipase Maintains Microglial Innate Immunity in Obesity

    Directory of Open Access Journals (Sweden)

    Yuanqing Gao

    2017-09-01

    Full Text Available Consumption of a hypercaloric diet upregulates microglial innate immune reactivity along with a higher expression of lipoprotein lipase (Lpl within the reactive microglia in the mouse brain. Here, we show that knockdown of the Lpl gene specifically in microglia resulted in deficient microglial uptake of lipid, mitochondrial fuel utilization shifting to glutamine, and significantly decreased immune reactivity. Mice with knockdown of the Lpl gene in microglia gained more body weight than control mice on a high-carbohydrate high-fat (HCHF diet. In these mice, microglial reactivity was significantly decreased in the mediobasal hypothalamus, accompanied by downregulation of phagocytic capacity and increased mitochondrial dysmorphologies. Furthermore, HCHF-diet-induced POMC neuronal loss was accelerated. These results show that LPL-governed microglial immunometabolism is essential to maintain microglial function upon exposure to an HCHF diet. In a hypercaloric environment, lack of such an adaptive immunometabolic response has detrimental effects on CNS regulation of energy metabolism.

  20. Microglial Over-Activation by Social Defeat Stress Contributes to Anxiety- and Depressive-Like Behaviors

    Directory of Open Access Journals (Sweden)

    Dirson J. Stein

    2017-10-01

    Full Text Available Hyper activation of the neuroimmune system is strongly related to the development of neuropsychiatric disorders. Psychosocial stress has been postulated to play an important role in triggering anxiety and major depression. In preclinical models, there is mounting evidence that social defeat stress activates microglial cells in the central nervous system. This type of stress could be one of the major factors in the development of these psychopathologies. Here, we reviewed the most recent literature on social defeat and the associated immunological reactions. We focused our attention on microglial cells and kept the effect of social defeat over microglia separate from the effect of this stressor on other immune cells and the influence of peripheral immune components in priming central immune reactions. Furthermore, we considered how social defeat stress affects microglial cells and the consequent development of anxiety- and depressive-like states in preclinical studies. We highlighted evidence for the negative impact of the over-activation of the neuroimmune system, especially by the overproduction of pro-inflammatory mediators and cytotoxins. Overproduction of these molecules may cause cellular damage and loss or decreased function of neuronal activity by excessively pruning synaptic connections that ultimately contribute to the development of anxiety- and depressive-like states.

  1. Time-dependent retinal ganglion cell loss, microglial activation and blood-retina-barrier tightness in an acute model of ocular hypertension.

    Science.gov (United States)

    Trost, A; Motloch, K; Bruckner, D; Schroedl, F; Bogner, B; Kaser-Eichberger, A; Runge, C; Strohmaier, C; Klein, B; Aigner, L; Reitsamer, H A

    2015-07-01

    Glaucoma is a group of neurodegenerative diseases characterized by the progressive loss of retinal ganglion cells (RGCs) and their axons, and is the second leading cause of blindness worldwide. Elevated intraocular pressure is a well known risk factor for the development of glaucomatous optic neuropathy and pharmacological or surgical lowering of intraocular pressure represents a standard procedure in glaucoma treatment. However, the treatment options are limited and although lowering of intraocular pressure impedes disease progression, glaucoma cannot be cured by the currently available therapy concepts. In an acute short-term ocular hypertension model in rat, we characterize RGC loss, but also microglial cell activation and vascular alterations of the retina at certain time points. The combination of these three parameters might facilitate a better evaluation of the disease progression, and could further serve as a new model to test novel treatment strategies at certain time points. Acute ocular hypertension (OHT) was induced by the injection of magnetic microbeads into the rat anterior chamber angle (n = 22) with magnetic position control, leading to constant elevation of IOP. At certain time points post injection (4d, 7d, 10d, 14d and 21d), RGC loss, microglial activation, and microvascular pericyte (PC) coverage was analyzed using immunohistochemistry with corresponding specific markers (Brn3a, Iba1, NG2). Additionally, the tightness of the retinal vasculature was determined via injections of Texas Red labeled dextran (10 kDa) and subsequently analyzed for vascular leakage. For documentation, confocal laser-scanning microscopy was used, followed by cell counts, capillary length measurements and morphological and statistical analysis. The injection of magnetic microbeads led to a progressive loss of RGCs at the five time points investigated (20.07%, 29.52%, 41.80%, 61.40% and 76.57%). Microglial cells increased in number and displayed an activated morphology

  2. Targeting Microglial Activation States as a Therapeutic Avenue in Parkinson’s Disease

    Directory of Open Access Journals (Sweden)

    Sudhakar R. Subramaniam

    2017-06-01

    Full Text Available Parkinson’s disease (PD is a chronic and progressive disorder characterized neuropathologically by loss of dopamine neurons in the substantia nigra, intracellular proteinaceous inclusions, reduction of dopaminergic terminals in the striatum, and increased neuroinflammatory cells. The consequent reduction of dopamine in the basal ganglia results in the classical parkinsonian motor phenotype. A growing body of evidence suggest that neuroinflammation mediated by microglia, the resident macrophage-like immune cells in the brain, play a contributory role in PD pathogenesis. Microglia participate in both physiological and pathological conditions. In the former, microglia restore the integrity of the central nervous system and, in the latter, they promote disease progression. Microglia acquire different activation states to modulate these cellular functions. Upon activation to the M1 phenotype, microglia elaborate pro-inflammatory cytokines and neurotoxic molecules promoting inflammation and cytotoxic responses. In contrast, when adopting the M2 phenotype microglia secrete anti-inflammatory gene products and trophic factors that promote repair, regeneration, and restore homeostasis. Relatively little is known about the different microglial activation states in PD and a better understanding is essential for developing putative neuroprotective agents. Targeting microglial activation states by suppressing their deleterious pro-inflammatory neurotoxicity and/or simultaneously enhancing their beneficial anti-inflammatory protective functions appear as a valid therapeutic approach for PD treatment. In this review, we summarize microglial functions and, their dual neurotoxic and neuroprotective role in PD. We also review molecules that modulate microglial activation states as a therapeutic option for PD treatment.

  3. Interaction of HmC1q with leech microglial cells: involvement of C1qBP-related molecule in the induction of cell chemotaxis

    Directory of Open Access Journals (Sweden)

    Tahtouh Muriel

    2012-02-01

    Full Text Available Abstract Background In invertebrates, the medicinal leech is considered to be an interesting and appropriate model to study neuroimmune mechanisms. Indeed, this non-vertebrate animal can restore normal function of its central nervous system (CNS after injury. Microglia accumulation at the damage site has been shown to be required for axon sprouting and for efficient regeneration. We characterized HmC1q as a novel chemotactic factor for leech microglial cell recruitment. In mammals, a C1q-binding protein (C1qBP alias gC1qR, which interacts with the globular head of C1q, has been reported to participate in C1q-mediated chemotaxis of blood immune cells. In this study, we evaluated the chemotactic activities of a recombinant form of HmC1q and its interaction with a newly characterized leech C1qBP that acts as its potential ligand. Methods Recombinant HmC1q (rHmC1q was produced in the yeast Pichia pastoris. Chemotaxis assays were performed to investigate rHmC1q-dependent microglia migration. The involvement of a C1qBP-related molecule in this chemotaxis mechanism was assessed by flow cytometry and with affinity purification experiments. The cellular localization of C1qBP mRNA and protein in leech was investigated using immunohistochemistry and in situ hybridization techniques. Results rHmC1q-stimulated microglia migrate in a dose-dependent manner. This rHmC1q-induced chemotaxis was reduced when cells were preincubated with either anti-HmC1q or anti-human C1qBP antibodies. A C1qBP-related molecule was characterized in leech microglia. Conclusions A previous study showed that recruitment of microglia is observed after HmC1q release at the cut end of axons. Here, we demonstrate that rHmC1q-dependent chemotaxis might be driven via a HmC1q-binding protein located on the microglial cell surface. Taken together, these results highlight the importance of the interaction between C1q and C1qBP in microglial activation leading to nerve repair in the medicinal

  4. Interaction of HmC1q with leech microglial cells: involvement of C1qBP-related molecule in the induction of cell chemotaxis.

    Science.gov (United States)

    Tahtouh, Muriel; Garçon-Bocquet, Annelise; Croq, Françoise; Vizioli, Jacopo; Sautière, Pierre-Eric; Van Camp, Christelle; Salzet, Michel; Nagnan-le Meillour, Patricia; Pestel, Joël; Lefebvre, Christophe

    2012-02-22

    In invertebrates, the medicinal leech is considered to be an interesting and appropriate model to study neuroimmune mechanisms. Indeed, this non-vertebrate animal can restore normal function of its central nervous system (CNS) after injury. Microglia accumulation at the damage site has been shown to be required for axon sprouting and for efficient regeneration. We characterized HmC1q as a novel chemotactic factor for leech microglial cell recruitment. In mammals, a C1q-binding protein (C1qBP alias gC1qR), which interacts with the globular head of C1q, has been reported to participate in C1q-mediated chemotaxis of blood immune cells. In this study, we evaluated the chemotactic activities of a recombinant form of HmC1q and its interaction with a newly characterized leech C1qBP that acts as its potential ligand. Recombinant HmC1q (rHmC1q) was produced in the yeast Pichia pastoris. Chemotaxis assays were performed to investigate rHmC1q-dependent microglia migration. The involvement of a C1qBP-related molecule in this chemotaxis mechanism was assessed by flow cytometry and with affinity purification experiments. The cellular localization of C1qBP mRNA and protein in leech was investigated using immunohistochemistry and in situ hybridization techniques. rHmC1q-stimulated microglia migrate in a dose-dependent manner. This rHmC1q-induced chemotaxis was reduced when cells were preincubated with either anti-HmC1q or anti-human C1qBP antibodies. A C1qBP-related molecule was characterized in leech microglia. A previous study showed that recruitment of microglia is observed after HmC1q release at the cut end of axons. Here, we demonstrate that rHmC1q-dependent chemotaxis might be driven via a HmC1q-binding protein located on the microglial cell surface. Taken together, these results highlight the importance of the interaction between C1q and C1qBP in microglial activation leading to nerve repair in the medicinal leech.

  5. Andrographolide Activates Keap1/Nrf2/ARE/HO-1 Pathway in HT22 Cells and Suppresses Microglial Activation by Aβ42 through Nrf2-Related Inflammatory Response.

    Science.gov (United States)

    Seo, Ji Yeon; Pyo, Euisun; An, Jin-Pyo; Kim, Jinwoong; Sung, Sang Hyun; Oh, Won Keun

    2017-01-01

    Therapeutic approach of Alzheimer's disease (AD) has been gradually diversified. We examined the therapeutic and preventive potential of andrographolide, which is a lactone diterpenoid from Andrographis paniculata , and focused on the Kelch-like ECH-associated protein 1 (Keap1)/nuclear factor (erythroid-derived 2)-like 2 (Nrf2)-mediated heme oxygenase (HO)-1-inducing effects and the inhibitory activity of amyloid beta (A β ) 42 -induced microglial activation related to Nrf2 and nuclear factor κ B (NF- κ B)-mediated inflammatory responses. Andrographolide induced the expression and translocation of Nrf2 from the cytoplasm to the nucleus, thereby activating antioxidant response element (ARE) gene transcription and HO-1 expression in murine hippocampal HT22 cells. Andrographolide eliminated intracellular A β 42 in BV-2 cells and decreased the production of interleukin (IL)-6, IL-1 β , prostaglandin (PG)E 2 , and nitric oxide (NO) because of artificial phagocytic A β 42 . It decreased pNF- κ B accumulation in the nucleus and the expression of inducible nitric oxide synthase (i-NOS) and cyclooxygenase II (COX-II) in the microglial BV-2 cell line. In summary, andrographolide activates Nrf2-mediated HO-1 expression and inhibits A β 42 -overexpressed microglial BV-2 cell activation. These results suggested that andrographolide might have the potential for further examination of the therapeutics of AD.

  6. Andrographolide Activates Keap1/Nrf2/ARE/HO-1 Pathway in HT22 Cells and Suppresses Microglial Activation by Aβ42 through Nrf2-Related Inflammatory Response

    Directory of Open Access Journals (Sweden)

    Ji Yeon Seo

    2017-01-01

    Full Text Available Therapeutic approach of Alzheimer’s disease (AD has been gradually diversified. We examined the therapeutic and preventive potential of andrographolide, which is a lactone diterpenoid from Andrographis paniculata, and focused on the Kelch-like ECH-associated protein 1 (Keap1/nuclear factor (erythroid-derived 2-like 2 (Nrf2-mediated heme oxygenase (HO-1-inducing effects and the inhibitory activity of amyloid beta (Aβ42-induced microglial activation related to Nrf2 and nuclear factor κB (NF-κB-mediated inflammatory responses. Andrographolide induced the expression and translocation of Nrf2 from the cytoplasm to the nucleus, thereby activating antioxidant response element (ARE gene transcription and HO-1 expression in murine hippocampal HT22 cells. Andrographolide eliminated intracellular Aβ42 in BV-2 cells and decreased the production of interleukin (IL-6, IL-1β, prostaglandin (PGE2, and nitric oxide (NO because of artificial phagocytic Aβ42. It decreased pNF-κB accumulation in the nucleus and the expression of inducible nitric oxide synthase (i-NOS and cyclooxygenase II (COX-II in the microglial BV-2 cell line. In summary, andrographolide activates Nrf2-mediated HO-1 expression and inhibits Aβ42-overexpressed microglial BV-2 cell activation. These results suggested that andrographolide might have the potential for further examination of the therapeutics of AD.

  7. Lipoprotein Lipase Maintains Microglial Innate Immunity in Obesity

    NARCIS (Netherlands)

    Gao, Yuanqing; Vidal-Itriago, Andrés; Kalsbeek, Martin J; Layritz, Clarita; García-Cáceres, Cristina; Tom, Robby Zachariah; Eichmann, Thomas O; Vaz, Frédéric M; Houtkooper, Riekelt H; van der Wel, Nicole; Verhoeven, Arthur J; Yan, Jie; Kalsbeek, A.; Eckel, Robert H; Hofmann, Susanna M; Yi, Chun-Xia

    2017-01-01

    Consumption of a hypercaloric diet upregulates microglial innate immune reactivity along with a higher expression of lipoprotein lipase (Lpl) within the reactive microglia in the mouse brain. Here, we show that knockdown of the Lpl gene specifically in microglia resulted in deficient microglial

  8. Quantitative Proteomics Reveals Temporal Proteomic Changes in Signaling Pathways during BV2 Mouse Microglial Cell Activation.

    Science.gov (United States)

    Woo, Jongmin; Han, Dohyun; Wang, Joseph Injae; Park, Joonho; Kim, Hyunsoo; Kim, Youngsoo

    2017-09-01

    The development of systematic proteomic quantification techniques in systems biology research has enabled one to perform an in-depth analysis of cellular systems. We have developed a systematic proteomic approach that encompasses the spectrum from global to targeted analysis on a single platform. We have applied this technique to an activated microglia cell system to examine changes in the intracellular and extracellular proteomes. Microglia become activated when their homeostatic microenvironment is disrupted. There are varying degrees of microglial activation, and we chose to focus on the proinflammatory reactive state that is induced by exposure to such stimuli as lipopolysaccharide (LPS) and interferon-gamma (IFN-γ). Using an improved shotgun proteomics approach, we identified 5497 proteins in the whole-cell proteome and 4938 proteins in the secretome that were associated with the activation of BV2 mouse microglia by LPS or IFN-γ. Of the differentially expressed proteins in stimulated microglia, we classified pathways that were related to immune-inflammatory responses and metabolism. Our label-free parallel reaction monitoring (PRM) approach made it possible to comprehensively measure the hyper-multiplex quantitative value of each protein by high-resolution mass spectrometry. Over 450 peptides that corresponded to pathway proteins and direct or indirect interactors via the STRING database were quantified by label-free PRM in a single run. Moreover, we performed a longitudinal quantification of secreted proteins during microglial activation, in which neurotoxic molecules that mediate neuronal cell loss in the brain are released. These data suggest that latent pathways that are associated with neurodegenerative diseases can be discovered by constructing and analyzing a pathway network model of proteins. Furthermore, this systematic quantification platform has tremendous potential for applications in large-scale targeted analyses. The proteomics data for

  9. Polysaccharides from Ganoderma lucidum attenuate microglia-mediated neuroinflammation and modulate microglial phagocytosis and behavioural response.

    Science.gov (United States)

    Cai, Qing; Li, Yuanyuan; Pei, Gang

    2017-03-24

    Ganoderma lucidum (GL) has been widely used in Asian countries for hundreds of years to promote health and longevity. The pharmacological functions of which had been classified, including the activation of innate immune responses, suppression of tumour and modulation of cell proliferations. Effective fractions of Ganoderma lucidum polysaccharides (GLP) had already been reported to regulate the immune system. Nevertheless, the role of GLP in the microglia-mediated neuroinflammation has not been sufficiently elucidated. Further, GLP effect on microglial behavioural modulations in correlation with the inflammatory responses remains to be unravelled. The aim of this work was to quantitatively analyse the contributions of GLP on microglia. The BV2 microglia and primary mouse microglia were stimulated by lipopolysaccharides (LPS) and amyloid beta 42 (Aβ 42 ) oligomer, respectively. Investigation on the effect of GLP was carried by quantitative determination of the microglial pro- and anti-inflammatory cytokine expressions and behavioural modulations including migration, morphology and phagocytosis. Analysis of microglial morphology and phagocytosis modulations was confirmed in the zebrafish brain. Quantitative results revealed that GLP down-regulates LPS- or Aβ-induced pro-inflammatory cytokines and promotes anti-inflammatory cytokine expressions in BV-2 and primary microglia. In addition, GLP attenuates inflammation-related microglial migration, morphological alterations and phagocytosis probabilities. We also showed that modulations of microglial behavioural responses were associated with MCP-1 and C1q expressions. Overall, our study provides an insight into the GLP regulation of LPS- and Aβ-induced neuroinflammation and serves an implication that the neuroprotective function of GLP might be achieved through modulation of microglial inflammatory and behavioural responses.

  10. Neuroprotection of Scutellarin is mediated by inhibition of microglial inflammatory activation.

    Science.gov (United States)

    Wang, S; Wang, H; Guo, H; Kang, L; Gao, X; Hu, L

    2011-06-30

    Inhibition of microglial over-reaction and the inflammatory processes may represent a therapeutic target to alleviate the progression of neurological diseases, such as neurodegenerative diseases and stroke. Scutellarin is the major active component of Erigeron breviscapus (Vant.) Hand-Mazz, a herbal medicine in treatment of cerebrovascular diseases for a long time in the Orient. In this study, we explored the mechanisms of neuroprotection by Scutellarin, particularly its anti-inflammatory effects in microglia. We observed that Scutellarin inhibited lipopolysaccharide (LPS)-induced production of proinflammatory mediators such as nitric oxide (NO), tumor necrosis factor α (TNFα), interleukin-1β (IL-1β) and reactive oxygen species (ROS), suppressed LPS-stimulated inducible nitric oxide synthase (iNOS), TNFα, and IL-1β mRNA expression in rat primary microglia or BV-2 mouse microglial cell line. Scutellarin inhibited LPS-induced nuclear translocation and DNA binding activity of nuclear factor κB (NF-κB). It repressed the LPS-induced c-Jun N-terminal kinase (JNK) and p38 phosphorylation without affecting the activity of extracellular signal regulated kinase (ERK) mitogen-activated protein kinase. Moreover, Scutellarin also inhibited interferon-γ (IFN-γ)-induced NO production, iNOS mRNA expression and transcription factor signal transducer and activator of transcription 1α (STAT1α) activation. Concomitantly, conditioned media from Scutellarin pretreated BV-2 cells significantly reduced neurotoxicity compared with conditioned media from LPS treated alone. Together, the present study reported the anti-inflammatory activity of Scutellarin in microglial cells along with their underlying molecular mechanisms, and suggested Scutellarin might have therapeutic potential for various microglia mediated neuroinflammation. Copyright © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

  11. Clearing the corpses: regulatory mechanisms, novel tools, and therapeutic potential of harnessing microglial phagocytosis in the diseased brain

    Directory of Open Access Journals (Sweden)

    Irune Diaz-Aparicio

    2016-01-01

    Full Text Available Apoptosis is a widespread phenomenon that occurs in the brain in both physiological and pathological conditions. Dead cells must be quickly removed to avoid the further toxic effects they exert in the parenchyma, a process executed by microglia, the brain professional phagocytes. Although phagocytosis is critical to maintain tissue homeostasis, it has long been either overlooked or indirectly assessed based on microglial morphology, expression of classical activation markers, or engulfment of artificial phagocytic targets in vitro. Nevertheless, these indirect methods present several limitations and, thus, direct observation and quantification of microglial phagocytosis is still necessary to fully grasp its relevance in the diseased brain. To overcome these caveats and obtain a comprehensive, quantitative picture of microglial phagocytosis we have developed a novel set of parameters. These parameters have allowed us to identify the different strategies utilized by microglia to cope with apoptotic challenges induced by excitotoxicity or inflammation. In contrast, we discovered that in mouse and human epilepsy microglia failed to find and engulf apoptotic cells, resulting in accumulation of debris and inflammation. Herein, we advocate that the efficiency of microglial phagocytosis should be routinely tested in neurodegenerative and neurological disorders, in order to determine the extent to which it contributes to apoptosis and inflammation found in these conditions. Finally, our findings point towards enhancing microglial phagocytosis as a novel therapeutic strategy to control tissue damage and inflammation, and accelerate recovery in brain diseases.

  12. Annexin-1 Mediates Microglial Activation and Migration via the CK2 Pathway during Oxygen–Glucose Deprivation/Reperfusion

    Directory of Open Access Journals (Sweden)

    Shuangxi Liu

    2016-10-01

    Full Text Available Annexin-1 (ANXA1 has shown neuroprotective effects and microglia play significant roles during central nervous system injury, yet the underlying mechanisms remain unclear. This study sought to determine whether ANXA1 regulates microglial response to oxygen–glucose deprivation/reperfusion (OGD/R treatment and to clarify the downstream molecular mechanism. In rat hippocampal slices, OGD/R treatment enhanced the ANXA1 expression in neuron, the formyl peptide receptor (FPRs expression in microglia, and the microglial activation in the CA1 region (cornu ammonis 1. These effects were reversed by the FPRs antagonist Boc1. The cell membrane currents amplitude of BV-2 microglia (the microglial like cell-line was increased when treated with Ac2-26, the N-terminal peptide of ANXA1. Ac2-26 treatment enhanced BV-2 microglial migration whereas Boc1 treatment inhibited the migration. In BV-2 microglia, both the expression of the CK2 target phosphorylated α-E-catenin and the binding of casein kinase II (CK2 with α-E-catenin were elevated by Ac2-26, these effects were counteracted by the CK2 inhibitor TBB and small interfering (si RNA directed against transcripts of CK2 and FPRs. Moreover, both TBB and siRNA-mediated inhibition of CK2 blocked Ac2-26-mediated BV-2 microglia migration. Our findings indicate that ANXA1 promotes microglial activation and migration during OGD/R via FPRs, and CK2 target α-E-catenin phosphorylation is involved in this process.

  13. Enhanced detection and study of murine norovirus-1 using a more efficient microglial cell line

    Directory of Open Access Journals (Sweden)

    Lu Yuanan

    2009-11-01

    Full Text Available Abstract Background Human Noroviruses are the predominant cause of non-bacterial gastroenteritis worldwide. To facilitate prevention and control, a norovirus isolated from mice can provide a model to understand human noroviruses. To establish optimal viral infectivity conditions for murine noroviruses, several cell lines of hematopoietic lineage, including murine BV-2, RAW 264.7, and TIB, as well as human CHME-5, were tested comparatively for their sensitivity to murine norovirus-1. Results Except for CHME-5, all three murine-derived cell lines were susceptible to MNV infection. Viral infection of these cells was confirmed by RT-PCR. Using both viral plaque and replication assays, BV-2 and RAW 264.7 cells were determined to have comparable sensitivities to MNV-1 infection. Comparisons of cell growth characteristics, general laboratory handling and potential in-field applications suggest the use of BV-2 to be more advantageous. Conclusion Results obtained from these studies demonstrate that an immortalized microglial cell line can support MNV-1 replication and provides a more efficient method to detect and study murine noroviruses, facilitating future investigations using MNV-1 as a model to study, detect, and control Human Norovirus.

  14. A common carcinogen benzo[a]pyrene causes neuronal death in mouse via microglial activation.

    Directory of Open Access Journals (Sweden)

    Kallol Dutta

    Full Text Available BACKGROUND: Benzo[a]pyrene (B[a]P belongs to a class of polycyclic aromatic hydrocarbons that serve as micropollutants in the environment. B[a]P has been reported as a probable carcinogen in humans. Exposure to B[a]P can take place by ingestion of contaminated (especially grilled, roasted or smoked food or water, or inhalation of polluted air. There are reports available that also suggests neurotoxicity as a result of B[a]P exposure, but the exact mechanism of action is unknown. METHODOLOGY/PRINCIPAL FINDINGS: Using neuroblastoma cell line and primary cortical neuron culture, we demonstrated that B[a]P has no direct neurotoxic effect. We utilized both in vivo and in vitro systems to demonstrate that B[a]P causes microglial activation. Using microglial cell line and primary microglial culture, we showed for the first time that B[a]P administration results in elevation of reactive oxygen species within the microglia thereby causing depression of antioxidant protein levels; enhanced expression of inducible nitric oxide synthase, that results in increased production of NO from the cells. Synthesis and secretion of proinflammatory cytokines were also elevated within the microglia, possibly via the p38MAP kinase pathway. All these factors contributed to bystander death of neurons, in vitro. When administered to animals, B[a]P was found to cause microglial activation and astrogliosis in the brain with subsequent increase in proinflammatory cytokine levels. CONCLUSIONS/SIGNIFICANCE: Contrary to earlier published reports we found that B[a]P has no direct neurotoxic activity. However, it kills neurons in a bystander mechanism by activating the immune cells of the brain viz the microglia. For the first time, we have provided conclusive evidence regarding the mechanism by which the micropollutant B[a]P may actually cause damage to the central nervous system. In today's perspective, where rising pollution levels globally are a matter of grave concern, our

  15. Headmasters: Microglial regulation of learning and memory in health and disease

    Directory of Open Access Journals (Sweden)

    Laetitia Weinhard

    2018-03-01

    Full Text Available Microglia are mononuclear phagocytes that reside throughout the lifetime of the animal in the central nervous system (CNS. Originating from the yolk sac, microglial progenitors infiltrate the developing brain anlage even before the formation of the neural network. Mature microglial cells persist by slow rates of self-renewal that vary across brain regions. Eminent studies in the recent decade have highlighted a role for steady state microglia in neurogenesis, synaptic pruning, and formation and maintenance of connectivity within the CNS, which are critical to learning and memory functions. Activity- and learning-dependent synaptic remodeling by microglia has been described in various contexts. Molecular pathways, including signaling through fractalkine CX3CL1 and its receptor CX3CR1, transforming growth factor-beta, classical complement system, colony-stimulating factor 1 receptor, adaptor protein DAP12, and brain-derived neurotropic factor, have been proposed to be important mediators of synaptic plasticity regulated by microglia. Reactive, dysfunctional, or aged microglia are thought to impact learning and memory, and are implicated in human neurodegenerative disorders in which dementia is a hallmark. These disorders include Nasu-Hakola disease, hereditary diffuse leukoencephaly with spheroids, Alzheimer’s disease, frontotemporal dementia, and Parkinson’s disease. Focusing on microglia, here we discuss the potential detrimental effects and risks presented by microglia-specific genetic variants, the environmental factors that target microglia, and microglial aging that likely lead to progressive memory loss in neurodegenerative diseases. Finally, we consider some caveats of the animal model systems that to date have advanced our understanding of microglial regulation of learning and memory.

  16. Botanical Polyphenols Mitigate Microglial Activation and Microglia-Induced Neurotoxicity: Role of Cytosolic Phospholipase A2.

    Science.gov (United States)

    Chuang, Dennis Y; Simonyi, Agnes; Cui, Jiankun; Lubahn, Dennis B; Gu, Zezong; Sun, Grace Y

    2016-09-01

    Microglia play a significant role in the generation and propagation of oxidative/nitrosative stress, and are the basis of neuroinflammatory responses in the central nervous system. Upon stimulation by endotoxins such as lipopolysaccharides (LPS), these cells release pro-inflammatory factors which can exert harmful effects on surrounding neurons, leading to secondary neuronal damage and cell death. Our previous studies demonstrated the effects of botanical polyphenols to mitigate inflammatory responses induced by LPS, and highlighted an important role for cytosolic phospholipase A2 (cPLA2) upstream of the pro-inflammatory pathways (Chuang et al. in J Neuroinflammation 12(1):199, 2015. doi: 10.1186/s12974-015-0419-0 ). In this study, we investigate the action of botanical compounds and assess whether suppression of cPLA2 in microglia is involved in the neurotoxic effects on neurons. Differentiated SH-SY5Y neuroblastoma cells were used to test the neurotoxicity of conditioned medium from stimulated microglial cells, and WST-1 assay was used to assess for the cell viability of SH-SY5Y cells. Botanicals such as quercetin and honokiol (but not cyanidin-3-O-glucoside, 3CG) were effective in inhibiting LPS-induced nitric oxide (NO) production and phosphorylation of cPLA2. Conditioned medium from BV-2 cells stimulated with LPS or IFNγ caused neurotoxicity to SH-SY5Y cells. Decrease in cell viability could be ameliorated by pharmacological inhibitors for cPLA2 as well as by down-regulating cPLA2 with siRNA. Botanicals effective in inhibition of LPS-induced NO and cPLA2 phosphorylation were also effective in ameliorating microglial-induced neurotoxicity. Results demonstrated cytotoxic factors from activated microglial cells to cause damaging effects to neurons and potential use of botanical polyphenols to ameliorate the neurotoxic effects.

  17. Effects of Low Phytanic Acid-Concentrated DHA on Activated Microglial Cells: Comparison with a Standard Phytanic Acid-Concentrated DHA.

    Science.gov (United States)

    Ruiz-Roso, María Belén; Olivares-Álvaro, Elena; Quintela, José Carlos; Ballesteros, Sandra; Espinosa-Parrilla, Juan F; Ruiz-Roso, Baltasar; Lahera, Vicente; de Las Heras, Natalia; Martín-Fernández, Beatriz

    2018-05-30

    Docosahexaenoic acid (DHA, 22:6 n-3) is an essential omega-3 (ω-3) long chain polyunsaturated fatty acid of neuronal membranes involved in normal growth, development, and function. DHA has been proposed to reduce deleterious effects in neurodegenerative processes. Even though, some inconsistencies in findings from clinical and pre-clinical studies with DHA could be attributed to the presence of phytanic acid (PhA) in standard DHA treatments. Thus, the aim of our study was to analyze and compare the effects of a low PhA-concentrated DHA with a standard PhA-concentrated DHA under different neurotoxic conditions in BV-2 activated microglial cells. To this end, mouse microglial BV-2 cells were stimulated with either lipopolysaccharide (LPS) or hydrogen peroxide (H 2 O 2 ) and co-incubated with DHA 50 ppm of PhA (DHA (PhA:50)) or DHA 500 ppm of PhA (DHA (PhA:500)). Cell viability, superoxide anion (O 2 - ) production, Interleukin 6 (L-6), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), glutathione peroxidase (GtPx), glutathione reductase (GtRd), Caspase-3, and the brain-derived neurotrophic factor (BDNF) protein expression were explored. Low PhA-concentrated DHA protected against LPS or H 2 O 2 -induced cell viability reduction in BV-2 activated cells and O 2 - production reduction compared to DHA (PhA:500). Low PhA-concentrated DHA also decreased COX-2, IL-6, iNOS, GtPx, GtRd, and SOD-1 protein expression when compared to DHA (PhA:500). Furthermore, low PhA-concentrated DHA increased BDNF protein expression in comparison to DHA (PhA:500). The study provides data supporting the beneficial effect of low PhA-concentrated DHA in neurotoxic injury when compared to a standard PhA-concentrated DHA in activated microglia.

  18. Delta-opioid receptor analgesia is independent of microglial activation in a rat model of neuropathic pain.

    Directory of Open Access Journals (Sweden)

    Joanna Mika

    Full Text Available The analgesic effect of delta-opioid receptor (DOR ligands in neuropathic pain is not diminished in contrast to other opioid receptor ligands, which lose their effectiveness as analgesics. In this study, we examine whether this effect is related to nerve injury-induced microglial activation. We therefore investigated the influence of minocycline-induced inhibition of microglial activation on the analgesic effects of opioid receptor agonists: morphine, DAMGO, U50,488H, DPDPE, Deltorphin II and SNC80 after chronic constriction injury (CCI to the sciatic nerve in rats. Pre-emptive and repeated administration of minocycline (30 mg/kg, i.p. over 7 days significantly reduced allodynia and hyperalgesia as measured on day 7 after CCI. The antiallodynic and antihyperalgesic effects of intrathecally (i.t. administered morphine (10-20 µg, DAMGO (1-2 µg and U50,488H (25-50 µg were significantly potentiated in rats after minocycline, but no such changes were observed after DPDPE (10-20 µg, deltorphin II (1.5-15 µg and SNC80 (10-20 µg administration. Additionally, nerve injury-induced down-regulation of all types of opioid receptors in the spinal cord and dorsal root ganglia was not influenced by minocycline, which indicates that the effects of opioid ligands are dependent on other changes, presumably neuroimmune interactions. Our study of rat primary microglial cell culture using qRT-PCR, Western blotting and immunocytochemistry confirmed the presence of mu-opioid receptors (MOR and kappa-opioid receptors (KOR, further we provide the first evidence for the lack of DOR on microglial cells. In summary, DOR analgesia is different from analgesia induced by MOR and KOR receptors because it does not dependent on injury-induced microglial activation. DOR agonists appear to be the best candidates for new drugs to treat neuropathic pain.

  19. Aspirin down Regulates Hepcidin by Inhibiting NF-κB and IL6/JAK2/STAT3 Pathways in BV-2 Microglial Cells Treated with Lipopolysaccharide

    Directory of Open Access Journals (Sweden)

    Wan-Ying Li

    2016-12-01

    Full Text Available Aspirin down regulates transferrin receptor 1 (TfR1 and up regulates ferroportin 1 (Fpn1 and ferritin expression in BV-2 microglial cells treated without lipopolysaccharides (LPS, as well as down regulates hepcidin and interleukin 6 (IL-6 in cells treated with LPS. However, the relevant mechanisms are unknown. Here, we investigate the effects of aspirin on expression of hepcidin and iron regulatory protein 1 (IRP1, phosphorylation of Janus kinase 2 (JAK2, signal transducer and activator of transcription 3 (STAT3 and P65 (nuclear factor-κB, and the production of nitric oxide (NO in BV-2 microglial cells treated with and without LPS. We demonstrated that aspirin inhibited hepcidin mRNA as well as NO production in cells treated with LPS, but not in cells without LPS, suppresses IL-6, JAK2, STAT3, and P65 (nuclear factor-κB phosphorylation and has no effect on IRP1 in cells treated with or without LPS. These findings provide evidence that aspirin down regulates hepcidin by inhibiting IL6/JAK2/STAT3 and P65 (nuclear factor-κB pathways in the cells under inflammatory conditions, and imply that an aspirin-induced reduction in TfR1 and an increase in ferritin are not associated with IRP1 and NO.

  20. Cannabinoid effects on β amyloid fibril and aggregate formation, neuronal and microglial-activated neurotoxicity in vitro.

    Science.gov (United States)

    Janefjord, Emelie; Mååg, Jesper L V; Harvey, Benjamin S; Smid, Scott D

    2014-01-01

    Cannabinoid (CB) ligands have demonstrated neuroprotective properties. In this study we compared the effects of a diverse set of CB ligands against β amyloid-mediated neuronal toxicity and activated microglial-conditioned media-based neurotoxicity in vitro, and compared this with a capacity to directly alter β amyloid (Aβ) fibril or aggregate formation. Neuroblastoma (SH-SY5Y) cells were exposed to Aβ1-42 directly or microglial (BV-2 cells) conditioned media activated with lipopolysaccharide (LPS) in the presence of the CB1 receptor-selective agonist ACEA, CB2 receptor-selective agonist JWH-015, phytocannabinoids Δ(9)-THC and cannabidiol (CBD), the endocannabinoids 2-arachidonoyl glycerol (2-AG) and anandamide or putative GPR18/GPR55 ligands O-1602 and abnormal-cannabidiol (Abn-CBD). TNF-α and nitrite production was measured in BV-2 cells to compare activation via LPS or albumin with Aβ1-42. Aβ1-42 evoked a concentration-dependent loss of cell viability in SH-SY5Y cells but negligible TNF-α and nitrite production in BV-2 cells compared to albumin or LPS. Both albumin and LPS-activated BV-2 conditioned media significantly reduced neuronal cell viability but were directly innocuous to SH-SY5Y cells. Of those CB ligands tested, only 2-AG and CBD were directly protective against Aβ-evoked SH-SY5Y cell viability, whereas JWH-015, THC, CBD, Abn-CBD and O-1602 all protected SH-SY5Y cells from BV-2 conditioned media activated via LPS. While CB ligands variably altered the morphology of Aβ fibrils and aggregates, there was no clear correlation between effects on Aβ morphology and neuroprotective actions. These findings indicate a neuroprotective action of CB ligands via actions at microglial and neuronal cells.

  1. Telomere dysfunction reduces microglial numbers without fully inducing an aging phenotype

    DEFF Research Database (Denmark)

    Khan, Asif Manzoor; Babcock, Alicia; Saeed, Hamid

    2015-01-01

    The susceptibility of the aging brain to neurodegenerative disease may in part be attributed to cellular aging of the microglial cells that survey it. We investigated the effect of cellular aging induced by telomere shortening on microglia by the use of mice lacking the telomerase RNA component...... (TERC) and design-based stereology. TERC knockout (KO) mice had a significantly reduced number of CD11b(+) microglia in the dentate gyrus. Because of an even greater reduction in dentate gyrus volume, microglial density was, however, increased. Microglia in TERC KO mice maintained a homogenous...... distribution and normal expression of CD45 and CD68 and the aging marker, ferritin, but were morphologically distinct from microglia in both adult and old wild-type mice. TERC KO mice also showed increased cellular apoptosis and impaired spatial learning. Our results suggest that individual microglia...

  2. Anti-inflammatory effects of sodium alginate/gelatine porous scaffolds merged with fucoidan in murine microglial BV2 cells.

    Science.gov (United States)

    Nguyen, Van-Tinh; Ko, Seok-Chun; Oh, Gun-Woo; Heo, Seong-Yeong; Jeon, You-Jin; Park, Won Sun; Choi, Il-Whan; Choi, Sung-Wook; Jung, Won-Kyo

    2016-12-01

    Microglia are the immune cells of the central nervous system (CNS). Overexpression of inflammatory mediators by microglia can induce several neurological diseases. Thus, the underlying basic requirement for neural tissue engineering is to develop materials that exhibit little or no neuro-inflammatory effects. In this study, we have developed a method to create porous scaffolds by adding fucoidan (Fu) into porous sodium alginate (Sa)/gelatine (G) (SaGFu). For mechanical characterization, in vitro degradation, stress/strain, swelling, and pore size were measured. Furthermore, the biocompatibility was evaluated by assessing the adhesion and proliferation of BV2 microglial cells on the SaGFu porous scaffolds using scanning electron microscopy (SEM) and lactate dehydrogenase (LDH) assay, respectively. Moreover, we studied the neuro-inflammatory effects of SaGFu on BV2 microglial cells. The effect of gelatine and fucoidan content on the various properties of the scaffold was investigated and the results showed that mechanical properties increased porosity and swelling ratio with an increase in the gelatine and fucoidan, while the in vitro biodegradability decreased. The average SaGFu diameter attained by fabrication of SaGFu ranged from 60 to 120μm with high porosity (74.44%-88.30%). Cell culture using gelatine 2.0% (SaG2Fu) and 4.0% (SaG4Fu), showed good cell proliferation; more than 60-80% that with Sa alone. Following stimulation with 0.5μg/mL LPS, microglia cultured in porous SaGFu decreased their expression of nitric oxide (NO), prostaglandin E2 (PGE2), and reactive oxygen species (ROS). SaG2Fu and SaG4Fu also inhibited the activation and translocation of p65 NF-κB protein levels, resulting in reduction of NO, ROS, and PGE2 production. These results provide insights into the diverse biological effects and opens new avenues for the applications of SaGFu in neuroscience. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Anti-Inflammatory Activity of Bee Venom in BV2 Microglial Cells: Mediation of MyD88-Dependent NF-κB Signaling Pathway.

    Science.gov (United States)

    Im, Eun Ju; Kim, Su Jung; Hong, Seung Bok; Park, Jin-Kyu; Rhee, Man Hee

    2016-01-01

    Bee venom has long been used as a traditional folk medicine in Korea. It has been reportedly used for the treatment of arthritis, cancer, and inflammation. Although its anti-inflammatory activity in lipopolysaccharide- (LPS-) stimulated inflammatory cells has been reported, the exact mechanism of its anti-inflammatory action has not been fully elucidated. Therefore, the aim of this study was to investigate the anti-inflammatory mechanism of bee venom in BV2 microglial cells. We first investigated whether NO production in LPS-activated BV2 cells was inhibited by bee venom, and further iNOS mRNA and protein expressions were determined. The mRNA and protein levels of proinflammatory cytokines were examined using semiquantitative RT-PCR and immunoblotting, respectively. Moreover, modulation of the transcription factor NF-κB by bee venom was also investigated using a luciferase assay. LPS-induced NO production in BV2 microglial cells was significantly inhibited in a concentration-dependent manner upon pretreatment with bee venom. Bee venom markedly reduced the mRNA expression of COX-2, TNF-α, IL-1β, and IL-6 and suppressed LPS-induced activation of MyD88 and IRAK1 and phosphorylation of TAK1. Moreover, NF-κB translocation by IKKα/β phosphorylation and subsequent IκB-α degradation were also attenuated. Thus, collectively, these results indicate that bee venom exerts its anti-inflammatory activity via the IRAK1/TAK1/NF-κB signaling pathway.

  4. Alzheimer's disease risk gene CD33 inhibits microglial uptake of amyloid beta.

    Science.gov (United States)

    Griciuc, Ana; Serrano-Pozo, Alberto; Parrado, Antonio R; Lesinski, Andrea N; Asselin, Caroline N; Mullin, Kristina; Hooli, Basavaraj; Choi, Se Hoon; Hyman, Bradley T; Tanzi, Rudolph E

    2013-05-22

    The transmembrane protein CD33 is a sialic acid-binding immunoglobulin-like lectin that regulates innate immunity but has no known functions in the brain. We have previously shown that the CD33 gene is a risk factor for Alzheimer's disease (AD). Here, we observed increased expression of CD33 in microglial cells in AD brain. The minor allele of the CD33 SNP rs3865444, which confers protection against AD, was associated with reductions in both CD33 expression and insoluble amyloid beta 42 (Aβ42) levels in AD brain. Furthermore, the numbers of CD33-immunoreactive microglia were positively correlated with insoluble Aβ42 levels and plaque burden in AD brain. CD33 inhibited uptake and clearance of Aβ42 in microglial cell cultures. Finally, brain levels of insoluble Aβ42 as well as amyloid plaque burden were markedly reduced in APP(Swe)/PS1(ΔE9)/CD33(-/-) mice. Therefore, CD33 inactivation mitigates Aβ pathology and CD33 inhibition could represent a novel therapy for AD. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Microglial TNF and IL-1 as early disease-modifiers in Alzheimer's-like disease in mice

    DEFF Research Database (Denmark)

    Ilkjær, Laura; Babcock, Alicia; Finsen, Bente

    2015-01-01

    In Alzheimer's disease (AD) signs of microglial activation is evident already in prodromal and early AD. This and other evidence suggest that neuroinflammation contributes to the progression of the early disease development in AD. Microglial cells have the capacity to produce cytokines such as TNF...... in the APPswe/PS1DE9 mouse model of AD. In these mice, cortical As plaque load shows a sigmoidal trajectory with age, as it does in AD. At 12 months of age, when As pathology is welldeveloped, TNF and IL-1s are produced in significantly higher proportions of microglia in the APPswe/PS1DE9 mice, than in wildtype...

  6. Age-specific function of α5β1 integrin in microglial migration during early colonization of the developing mouse cortex.

    Science.gov (United States)

    Smolders, Sophie Marie-Thérèse; Swinnen, Nina; Kessels, Sofie; Arnauts, Kaline; Smolders, Silke; Le Bras, Barbara; Rigo, Jean-Michel; Legendre, Pascal; Brône, Bert

    2017-07-01

    Microglia, the immune cells of the central nervous system, take part in brain development and homeostasis. They derive from primitive myeloid progenitors that originate in the yolk sac and colonize the brain mainly through intensive migration. During development, microglial migration speed declines which suggests that their interaction with the microenvironment changes. However, the matrix-cell interactions allowing dispersion within the parenchyma are unknown. Therefore, we aimed to better characterize the migration behavior and to assess the role of matrix-integrin interactions during microglial migration in the embryonic brain ex vivo. We focused on microglia-fibronectin interactions mediated through the fibronectin receptor α5β1 integrin because in vitro work indirectly suggested a role for this ligand-receptor pair. Using 2-photon time-lapse microscopy on acute ex vivo embryonic brain slices, we found that migration occurs in a saltatory pattern and is developmentally regulated. Most importantly, there is an age-specific function of the α5β1 integrin during microglial cortex colonization. At embryonic day (E) 13.5, α5β1 facilitates migration while from E15.5, it inhibits migration. These results indicate a developmentally regulated function of α5β1 integrin in microglial migration during colonization of the embryonic brain. © 2017 Wiley Periodicals, Inc.

  7. Brain Renin-Angiotensin System and Microglial Polarization: Implications for Aging and Neurodegeneration

    Directory of Open Access Journals (Sweden)

    Jose L. Labandeira-Garcia

    2017-05-01

    Full Text Available Microglia can transform into proinflammatory/classically activated (M1 or anti-inflammatory/alternatively activated (M2 phenotypes following environmental signals related to physiological conditions or brain lesions. An adequate transition from the M1 (proinflammatory to M2 (immunoregulatory phenotype is necessary to counteract brain damage. Several factors involved in microglial polarization have already been identified. However, the effects of the brain renin-angiotensin system (RAS on microglial polarization are less known. It is well known that there is a “classical” circulating RAS; however, a second RAS (local or tissue RAS has been observed in many tissues, including brain. The locally formed angiotensin is involved in local pathological changes of these tissues and modulates immune cells, which are equipped with all the components of the RAS. There are also recent data showing that brain RAS plays a major role in microglial polarization. Level of microglial NADPH-oxidase (Nox activation is a major regulator of the shift between M1/proinflammatory and M2/immunoregulatory microglial phenotypes so that Nox activation promotes the proinflammatory and inhibits the immunoregulatory phenotype. Angiotensin II (Ang II, via its type 1 receptor (AT1, is a major activator of the NADPH-oxidase complex, leading to pro-oxidative and pro-inflammatory effects. However, these effects are counteracted by a RAS opposite arm constituted by Angiotensin II/AT2 receptor signaling and Angiotensin 1–7/Mas receptor (MasR signaling. In addition, activation of prorenin-renin receptors may contribute to activation of the proinflammatory phenotype. Aged brains showed upregulation of AT1 and downregulation of AT2 receptor expression, which may contribute to a pro-oxidative pro-inflammatory state and the increase in neuron vulnerability. Several recent studies have shown interactions between the brain RAS and different factors involved in microglial polarization

  8. Anthocyanins Downregulate Lipopolysaccharide-Induced Inflammatory Responses in BV2 Microglial Cells by Suppressing the NF-κB and Akt/MAPKs Signaling Pathways

    Directory of Open Access Journals (Sweden)

    Yung Hyun Choi

    2013-01-01

    Full Text Available Anthocyanins are naturally occurring polyphenols that impart bright color to fruits, vegetables and plants and have a variety of protective properties, which have generally been attributed to their antioxidant capacity. However, little is known about the molecular mechanisms underlying anti-inflammatory effects of anthocyanins related to neurodegenerative diseases. Therefore, we determined whether anthocyanins isolated from black soybean seed coats would inhibit pro-inflammatory mediators and cytokines in lipopolysaccharide (LPS-stimulated murine BV2 microglial cells. Our results showed that anthocyanins significantly inhibited LPS-induced pro-inflammatory mediators, such as nitric oxide (NO and prostaglandin E2, and pro-inflammatory cytokines including tumor necrosis factor (TNF-α and interleukin (IL-1β, without significant cytotoxicity. Anthocyanins also downregulated excessive expression of inducible NO synthase, cyclooxygenase-2, TNF-α, and IL-1β in LPS-stimulated BV2 cells. Moreover, anthocyanins inhibited nuclear translocation of nuclear factor-kappa B (NF-κB by reducing inhibitor of NF-κB alpha degradation as well as phosphorylating extracellular signal-regulated kinase, c-Jun N-terminal kinase, p38 mitogen-activated protein kinase, and Akt. These findings suggest that anthocyanins may offer substantial therapeutic potential for treating inflammatory and neurodegenerative diseases accompanied by microglial activation.

  9. LRRK2 kinase inhibition prevents pathological microglial phagocytosis in response to HIV-1 Tat protein

    Directory of Open Access Journals (Sweden)

    Marker Daniel F

    2012-11-01

    Full Text Available Abstract Background Human Immunodeficiency Virus-1 (HIV-1 associated neurocognitive disorders (HANDs are accompanied by significant morbidity, which persists despite the use of combined antiretroviral therapy (cART. While activated microglia play a role in pathogenesis, changes in their immune effector functions, including phagocytosis and proinflammatory signaling pathways, are not well understood. We have identified leucine-rich repeat kinase 2 (LRRK2 as a novel regulator of microglial phagocytosis and activation in an in vitro model of HANDs, and hypothesize that LRRK2 kinase inhibition will attenuate microglial activation during HANDs. Methods We treated BV-2 immortalized mouse microglia cells with the HIV-1 trans activator of transcription (Tat protein in the absence or presence of LRRK2 kinase inhibitor (LRRK2i. We used Western blot, qRT-PCR, immunocytochemistry and latex bead engulfment assays to analyze LRRK2 protein levels, proinflammatory cytokine and phagocytosis receptor expression, LRRK2 cellular distribution and phagocytosis, respectively. Finally, we utilized ex vivo microfluidic chambers containing primary hippocampal neurons and BV-2 microglia cells to investigate microglial phagocytosis of neuronal axons. Results We found that Tat-treatment of BV-2 cells induced kinase activity associated phosphorylation of serine 935 on LRRK2 and caused the formation of cytoplasmic LRRK2 inclusions. LRRK2i decreased Tat-induced phosphorylation of serine 935 on LRRK2 and inhibited the formation of Tat-induced cytoplasmic LRRK2 inclusions. LRRK2i also decreased Tat-induced process extension in BV-2 cells. Furthermore, LRRK2i attenuated Tat-induced cytokine expression and latex bead engulfment. We examined relevant cellular targets in microfluidic chambers and found that Tat-treated BV-2 microglia cells cleared axonal arbor and engulfed neuronal elements, whereas saline treated controls did not. LRRK2i was found to protect axons in the presence

  10. Cromolyn Reduces Levels of the Alzheimer's Disease-Associated Amyloid β-Protein by Promoting Microglial Phagocytosis.

    Science.gov (United States)

    Zhang, Can; Griciuc, Ana; Hudry, Eloise; Wan, Yu; Quinti, Luisa; Ward, Joseph; Forte, Angela M; Shen, Xunuo; Ran, ChongZhao; Elmaleh, David R; Tanzi, Rudolph E

    2018-01-18

    Amyloid-beta protein (Aβ) deposition is a pathological hallmark of Alzheimer's disease (AD). Aβ deposition triggers both pro-neuroinflammatory microglial activation and neurofibrillary tangle formation. Cromolyn sodium is an asthma therapeutic agent previously shown to reduce Aβ levels in transgenic AD mouse brains after one-week of treatment. Here, we further explored these effects as well as the mechanism of action of cromolyn, alone, and in combination with ibuprofen in APP Swedish -expressing Tg2576 mice. Mice were treated for 3 months starting at 5 months of age, when the earliest stages of β-amyloid deposition begin. Cromolyn, alone, or in combination with ibuprofen, almost completely abolished longer insoluble Aβ species, i.e. Aβ40 and Aβ42, but increased insoluble Aβ38 levels. In addition to its anti-aggregation effects on Aβ, cromolyn, alone, or plus ibuprofen, but not ibuprofen alone, increased microglial recruitment to, and phagocytosis of β-amyloid deposits in AD mice. Cromolyn also promoted Aβ42 uptake in microglial cell-based assays. Collectively, our data reveal robust effects of cromolyn, alone, or in combination with ibuprofen, in reducing aggregation-prone Aβ levels and inducing a neuroprotective microglial activation state favoring Aβ phagocytosis versus a pro-neuroinflammatory state. These findings support the use of cromolyn, alone, or with ibuprofen, as a potential AD therapeutic.

  11. Activation of microglial cells triggers a release of brain-derived neurotrophic factor (BDNF) inducing their proliferation in an adenosine A2A receptor-dependent manner: A2A receptor blockade prevents BDNF release and proliferation of microglia

    Science.gov (United States)

    2013-01-01

    Background Brain-derived neurotrophic factor (BDNF) has been shown to control microglial responses in neuropathic pain. Since adenosine A2A receptors (A2ARs) control neuroinflammation, as well as the production and function of BDNF, we tested to see if A2AR controls the microglia-dependent secretion of BDNF and the proliferation of microglial cells, a crucial event in neuroinflammation. Methods Murine N9 microglial cells were challenged with lipopolysaccharide (LPS, 100 ng/mL) in the absence or in the presence of the A2AR antagonist, SCH58261 (50 nM), as well as other modulators of A2AR signaling. The BDNF cellular content and secretion were quantified by Western blotting and ELISA, A2AR density was probed by Western blotting and immunocytochemistry and cell proliferation was assessed by BrdU incorporation. Additionally, the A2AR modulation of LPS-driven cell proliferation was also tested in primary cultures of mouse microglia. Results LPS induced time-dependent changes of the intra- and extracellular levels of BDNF and increased microglial proliferation. The maximal LPS-induced BDNF release was time-coincident with an LPS-induced increase of the A2AR density. Notably, removing endogenous extracellular adenosine or blocking A2AR prevented the LPS-mediated increase of both BDNF secretion and proliferation, as well as exogenous BDNF-induced proliferation. Conclusions We conclude that A2AR activation plays a mandatory role controlling the release of BDNF from activated microglia, as well as the autocrine/paracrine proliferative role of BDNF. PMID:23363775

  12. Anti-Inflammatory Strategy for M2 Microglial Polarization Using Retinoic Acid-Loaded Nanoparticles

    Directory of Open Access Journals (Sweden)

    Marta Machado-Pereira

    2017-01-01

    Full Text Available Inflammatory mechanisms triggered by microglial cells are involved in the pathophysiology of several brain disorders, hindering repair. Herein, we propose the use of retinoic acid-loaded polymeric nanoparticles (RA-NP as a means to modulate microglia response towards an anti-inflammatory and neuroprotective phenotype (M2. RA-NP were first confirmed to be internalized by N9 microglial cells; nanoparticles did not affect cell survival at concentrations below 100 μg/mL. Then, immunocytochemical studies were performed to assess the expression of pro- and anti-inflammatory mediators. Our results show that RA-NP inhibited LPS-induced release of nitric oxide and the expression of inducible nitric oxide synthase and promoted arginase-1 and interleukin-4 production. Additionally, RA-NP induced a ramified microglia morphology (indicative of M2 state, promoting tissue viability, particularly neuronal survival, and restored the expression of postsynaptic protein-95 in organotypic hippocampal slice cultures exposed to an inflammatory challenge. RA-NP also proved to be more efficient than the free equivalent RA concentration. Altogether, our data indicate that RA-NP may be envisioned as a promising therapeutic agent for brain inflammatory diseases.

  13. Connexins and pannexins: New insights into microglial functions and dysfunctions

    Directory of Open Access Journals (Sweden)

    Rosario Gajardo-Gómez

    2016-09-01

    Full Text Available In a physiological context, microglia adopt a resting phenotype that is associated with the production of anti-inflammatory and neurotrophic factors. In response to a wide variety of insults, they shift to the activated phenotype that is necessary for the proper restoration of brain homeostasis. When the intensity of the threat is relatively high, microglial activation can worsen the damage progression instead of providing protection, with potentially significant consequences for neuronal survival. Coordinated interactions among microglia and with other brain cells, including astrocytes and neurons, is critical for the development of timely and optimal inflammatory responses in the brain parenchyma. Tissue synchronization is in part mediated by connexins and pannexins, which are protein families that form different plasma membrane channels to communicate with neighboring cells. At one end, the gap junction channels (which are exclusively formed by connexins in vertebrates connect the cytoplasm of contacting cells to coordinate electrical and metabolic coupling. At the other end, hemichannels and pannexons (which are formed by connexins and pannexins, respectively communicate via intra- and extracellular compartments and serve as diffusion pathways for the exchange of ions and small molecules. In this review, we discuss the evidence available concerning the functional expression and regulation of connexin- and pannexin-based channels in microglia and their contribution to microglial function and dysfunction. We focus on the possible implications of these channels in microglia-to-microglia, microglia-to-astrocyte and neuron-to-microglia interactions in the inflamed brain.

  14. Alzheimer’s Disease Risk Gene CD33 Inhibits Microglial Uptake of Amyloid Beta

    Science.gov (United States)

    Griciuc, Ana; Serrano-Pozo, Alberto; Parrado, Antonio R.; Lesinski, Andrea N.; Asselin, Caroline N.; Mullin, Kristina; Hooli, Basavaraj; Choi, Se Hoon; Hyman, Bradley T.; Tanzi, Rudolph E.

    2013-01-01

    SUMMARY The transmembrane protein CD33 is a sialic acid-binding immunoglobulin-like lectin that regulates innate immunity but has no known functions in the brain. We have previously shown that the CD33 gene is a risk factor for Alzheimer’s disease (AD). Here, we observed increased expression of CD33 in microglial cells in AD brain. The minor allele of the CD33 SNP rs3865444, which confers protection against AD, was associated with reductions in both CD33 expression and insoluble amyloid beta 42 (Aβ42) levels in AD brain. Furthermore, the numbers of CD33-immunoreactive microglia were positively correlated with insoluble Aβ42 levels and plaque burden in AD brain. CD33 inhibited uptake and clearance of Aβ42 in microglial cell cultures. Finally, brain levels of insoluble Aβ42 as well as amyloid plaque burden were markedly reduced in APPSwe/PS1ΔE9/CD33−/− mice. Therefore, CD33 inactivation mitigates Aβ pathology and CD33 inhibition could represent a novel therapy for AD. PMID:23623698

  15. C3-dependent mechanism of microglial priming relevant to multiple sclerosis

    NARCIS (Netherlands)

    Ramaglia, Valeria; Hughes, Timothy R.; Donev, Rossen M.; Ruseva, Marieta M.; Wu, Xiaobo; Huitinga, Inge; Baas, Frank; Neal, James W.; Morgan, B. Paul

    2012-01-01

    Microglial priming predisposes the brain to neurodegeneration and affects disease progression. The signal to switch from the quiescent to the primed state is unknown. We show that deleting the C3 convertase regulator complement receptor 1-related protein y (Crry) induces microglial priming. Mice

  16. Involvement of PKA and HO-1 signaling in anti-inflammatory effects of surfactin in BV-2 microglial cells

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sun Young; Kim, Ji-Hee [Department of Molecular Biology, College of Natural Sciences, Pusan National University, Jangjeon-dong, Keumjeong-gu, Busan 609-735 (Korea, Republic of); Lee, Sang Joon [Department of Microbiology, College of Natural Sciences, Pusan National University, Jangjeon-dong, Keumjeong-gu, Busan 609-735 (Korea, Republic of); Kim, YoungHee, E-mail: yheekim@pusan.ac.kr [Department of Molecular Biology, College of Natural Sciences, Pusan National University, Jangjeon-dong, Keumjeong-gu, Busan 609-735 (Korea, Republic of)

    2013-04-01

    Surfactin, one of the most powerful biosurfactants, is a bacterial cyclic lipopeptide. Here, we investigated the anti-neuroinflammatory properties of surfactin in lipoteichoic acid (LTA)-stimulated BV-2 microglial cells. Surfactin significantly inhibited excessive production of the pro-inflammatory mediators TNF-α, IL-1β, IL-6, monocyte chemoattractant protein-1 (MCP-1), prostaglandin E{sub 2} (PGE{sub 2}), nitric oxide (NO) and reactive oxygen species (ROS), and suppressed the expression of matrix metalloproteinase-9 (MMP-9), inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2). Subsequent mechanistic studies revealed that surfactin inhibited LTA-induced nuclear factor-kappaB (NF-κB) and signal transducer and activator of transcription-1 (STAT-1) activation. However, surfactin increases the phosphorylation of the STAT-3, a component of the homeostatic mechanism causing anti-inflammatory events. We also demonstrated that surfactin induces heme oxygenase-1 (HO-1) expression and nuclear factor-regulated factor-2 (Nrf-2) activation, and that the anti-inflammatory effects of surfactin are abrogated by small interfering RNA-mediated knock-down of HO-1 or Nrf-2. Interestingly, we found that surfactin increased the level of cAMP and induced phosphorylation of cAMP responsive element binding protein (CREB) in microglial cells. Furthermore, treatment with the protein kinase A (PKA) inhibitor, H-89, blocked HO-1 induction by surfactin and abolished surfactin's suppressive effects on ROS and NO production. These results indicate that HO-1 and its upstream effector, PKA, play a pivotal role in the anti-neuroinflammatory response of surfactin in LTA-stimulated microglia. Therefore, surfactin might have therapeutic potential for neuroprotective agents to treat inflammatory and neurodegenerative diseases. - Highlights: ► Surfactin inhibits proinflammatory mediator synthesis in LTA-activated BV-2 cells. ► Surfactin suppresses NF-κB and STAT-1, but potentiates

  17. Involvement of PKA and HO-1 signaling in anti-inflammatory effects of surfactin in BV-2 microglial cells

    International Nuclear Information System (INIS)

    Park, Sun Young; Kim, Ji-Hee; Lee, Sang Joon; Kim, YoungHee

    2013-01-01

    Surfactin, one of the most powerful biosurfactants, is a bacterial cyclic lipopeptide. Here, we investigated the anti-neuroinflammatory properties of surfactin in lipoteichoic acid (LTA)-stimulated BV-2 microglial cells. Surfactin significantly inhibited excessive production of the pro-inflammatory mediators TNF-α, IL-1β, IL-6, monocyte chemoattractant protein-1 (MCP-1), prostaglandin E 2 (PGE 2 ), nitric oxide (NO) and reactive oxygen species (ROS), and suppressed the expression of matrix metalloproteinase-9 (MMP-9), inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2). Subsequent mechanistic studies revealed that surfactin inhibited LTA-induced nuclear factor-kappaB (NF-κB) and signal transducer and activator of transcription-1 (STAT-1) activation. However, surfactin increases the phosphorylation of the STAT-3, a component of the homeostatic mechanism causing anti-inflammatory events. We also demonstrated that surfactin induces heme oxygenase-1 (HO-1) expression and nuclear factor-regulated factor-2 (Nrf-2) activation, and that the anti-inflammatory effects of surfactin are abrogated by small interfering RNA-mediated knock-down of HO-1 or Nrf-2. Interestingly, we found that surfactin increased the level of cAMP and induced phosphorylation of cAMP responsive element binding protein (CREB) in microglial cells. Furthermore, treatment with the protein kinase A (PKA) inhibitor, H-89, blocked HO-1 induction by surfactin and abolished surfactin's suppressive effects on ROS and NO production. These results indicate that HO-1 and its upstream effector, PKA, play a pivotal role in the anti-neuroinflammatory response of surfactin in LTA-stimulated microglia. Therefore, surfactin might have therapeutic potential for neuroprotective agents to treat inflammatory and neurodegenerative diseases. - Highlights: ► Surfactin inhibits proinflammatory mediator synthesis in LTA-activated BV-2 cells. ► Surfactin suppresses NF-κB and STAT-1, but potentiates phosphorylation

  18. System xC- is a mediator of microglial function and its deletion slows symptoms in amyotrophic lateral sclerosis mice.

    Science.gov (United States)

    Mesci, Pinar; Zaïdi, Sakina; Lobsiger, Christian S; Millecamps, Stéphanie; Escartin, Carole; Seilhean, Danielle; Sato, Hideyo; Mallat, Michel; Boillée, Séverine

    2015-01-01

    Amyotrophic lateral sclerosis is the most common adult-onset motor neuron disease and evidence from mice expressing amyotrophic lateral sclerosis-causing SOD1 mutations suggest that neurodegeneration is a non-cell autonomous process where microglial cells influence disease progression. However, microglial-derived neurotoxic factors still remain largely unidentified in amyotrophic lateral sclerosis. With excitotoxicity being a major mechanism proposed to cause motor neuron death in amyotrophic lateral sclerosis, our hypothesis was that excessive glutamate release by activated microglia through their system [Formula: see text] (a cystine/glutamate antiporter with the specific subunit xCT/Slc7a11) could contribute to neurodegeneration. Here we show that xCT expression is enriched in microglia compared to total mouse spinal cord and absent from motor neurons. Activated microglia induced xCT expression and during disease, xCT levels were increased in both spinal cord and isolated microglia from mutant SOD1 amyotrophic lateral sclerosis mice. Expression of xCT was also detectable in spinal cord post-mortem tissues of patients with amyotrophic lateral sclerosis and correlated with increased inflammation. Genetic deletion of xCT in mice demonstrated that activated microglia released glutamate mainly through system [Formula: see text]. Interestingly, xCT deletion also led to decreased production of specific microglial pro-inflammatory/neurotoxic factors including nitric oxide, TNFa and IL6, whereas expression of anti-inflammatory/neuroprotective markers such as Ym1/Chil3 were increased, indicating that xCT regulates microglial functions. In amyotrophic lateral sclerosis mice, xCT deletion surprisingly led to earlier symptom onset but, importantly, this was followed by a significantly slowed progressive disease phase, which resulted in more surviving motor neurons. These results are consistent with a deleterious contribution of microglial-derived glutamate during symptomatic

  19. Zinc Oxide Nanoparticle Induces Microglial Death by NADPH-Oxidase-Independent Reactive Oxygen Species as well as Energy Depletion.

    Science.gov (United States)

    Sharma, Anuj Kumar; Singh, Vikas; Gera, Ruchi; Purohit, Mahaveer Prasad; Ghosh, Debabrata

    2017-10-01

    Zinc oxide nanoparticle (ZnO-NP) is one of the most widely used engineered nanoparticles. Upon exposure, nanoparticle can eventually reach the brain through various routes, interact with different brain cells, and alter their activity. Microglia is the fastest glial cell to respond to any toxic insult. Nanoparticle exposure can activate microglia and induce neuroinflammation. Simultaneous to activation, microglial death can exacerbate the scenario. Therefore, we focused on studying the effect of ZnO-NP on microglia and finding out the pathway involved in the microglial death. The present study showed that the 24 h inhibitory concentration 50 (IC 50 ) of ZnO-NP for microglia is 6.6 μg/ml. Early events following ZnO-NP exposure involved increase in intracellular calcium level as well as reactive oxygen species (ROS). Neither of NADPH oxidase inhibitors, apocynin, (APO) and diphenyleneiodonium chloride (DPIC) were able to reduce the ROS level and rescue microglia from ZnO-NP toxicity. In contrary, N-acetyl cysteine (NAC) showed opposite effect. Exogenous supplementation of superoxide dismutase (SOD) reduced ROS significantly even beyond control level but partially rescued microglial viability. Interestingly, pyruvate supplementation rescued microglia near to control level. Following 10 h of ZnO-NP exposure, intracellular ATP level was measured to be almost 50 % to the control. ZnO-NP-induced ROS as well as ATP depletion both disturbed mitochondrial membrane potential and subsequently triggered the apoptotic pathway. The level of apoptosis-inducing proteins was measured by western blot analysis and found to be upregulated. Taken together, we have deciphered that ZnO-NP induced microglial apoptosis by NADPH oxidase-independent ROS as well as ATP depletion.

  20. Plasticity of cell migration: a multiscale tuning model.

    NARCIS (Netherlands)

    Friedl, P.H.A.; Wolf, K. van der

    2010-01-01

    Cell migration underlies tissue formation, maintenance, and regeneration as well as pathological conditions such as cancer invasion. Structural and molecular determinants of both tissue environment and cell behavior define whether cells migrate individually (through amoeboid or mesenchymal modes) or

  1. Complexity of the Microglial Activation Pathways that Drive Innate Host Responses During Lethal Alphavirus Encephalitis in Mice

    Directory of Open Access Journals (Sweden)

    Nilufer Esen

    2012-04-01

    Full Text Available Microglia express multiple TLRs (Toll-like receptors and provide important host defence against viruses that invade the CNS (central nervous system. Although prior studies show these cells become activated during experimental alphavirus encephalitis in mice to generate cytokines and chemokines that influence virus replication, tissue inflammation and neuronal survival, the specific PRRs (pattern recognition receptors and signalling intermediates controlling microglial activation in this setting remain unknown. To investigate these questions directly in vivo, mice ablated of specific TLR signalling molecules were challenged with NSV (neuroadapted Sindbis virus and CNS viral titres, inflammatory responses and clinical outcomes followed over time. To approach this problem specifically in microglia, the effects of NSV on primary cells derived from the brains of wild-type and mutant animals were characterized in vitro. From the standpoint of the virus, microglial activation required viral uncoating and an intact viral genome; inactivated virus particles did not elicit measurable microglial responses. At the level of the target cell, NSV triggered multiple PRRs in microglia to produce a broad range of inflammatory mediators via non-overlapping signalling pathways. In vivo, disease survival was surprisingly independent of TLR-driven responses, but still required production of type-I IFN (interferon to control CNS virus replication. Interestingly, the ER (endoplasmic reticulum protein UNC93b1 facilitated host survival independent of its known effects on endosomal TLR signalling. Taken together, these data show that alphaviruses activate microglia via multiple PRRs, highlighting the complexity of the signalling networks by which CNS host responses are elicited by these infections.

  2. Dia-Interacting Protein (DIP) Imposes Migratory Plasticity in mDia2-Dependent Tumor Cells in Three-Dimensional Matrices

    Science.gov (United States)

    Wyse, Meghan M.; Lei, Jun; Nestor-Kalinoski, Andrea L.; Eisenmann, Kathryn M.

    2012-01-01

    Tumor cells rely upon membrane pliancy to escape primary lesions and invade secondary metastatic sites. This process relies upon localized assembly and disassembly cycles of F-actin that support and underlie the plasma membrane. Dynamic actin generates both spear-like and bleb structures respectively characterizing mesenchymal and amoeboid motility programs utilized by metastatic cells in three-dimensional matrices. The molecular mechanism and physiological trigger(s) driving membrane plasticity are poorly understood. mDia formins are F-actin assembly factors directing membrane pliancy in motile cells. mDia2 is functionally coupled with its binding partner DIP, regulating cortical actin and inducing membrane blebbing in amoeboid cells. Here we show that mDia2 and DIP co-tether to nascent blebs and this linkage is required for bleb formation. DIP controls mesenchymal/amoeboid cell interconvertability, while CXCL12 induces assembly of mDia2:DIP complexes to bleb cortices in 3D matrices. These results demonstrate how DIP-directed mDia2-dependent F-actin dynamics regulate morphological plasticity in motile cancer cells. PMID:23024796

  3. Dia-interacting protein (DIP imposes migratory plasticity in mDia2-dependent tumor cells in three-dimensional matrices.

    Directory of Open Access Journals (Sweden)

    Meghan M Wyse

    Full Text Available Tumor cells rely upon membrane pliancy to escape primary lesions and invade secondary metastatic sites. This process relies upon localized assembly and disassembly cycles of F-actin that support and underlie the plasma membrane. Dynamic actin generates both spear-like and bleb structures respectively characterizing mesenchymal and amoeboid motility programs utilized by metastatic cells in three-dimensional matrices. The molecular mechanism and physiological trigger(s driving membrane plasticity are poorly understood. mDia formins are F-actin assembly factors directing membrane pliancy in motile cells. mDia2 is functionally coupled with its binding partner DIP, regulating cortical actin and inducing membrane blebbing in amoeboid cells. Here we show that mDia2 and DIP co-tether to nascent blebs and this linkage is required for bleb formation. DIP controls mesenchymal/amoeboid cell interconvertability, while CXCL12 induces assembly of mDia2:DIP complexes to bleb cortices in 3D matrices. These results demonstrate how DIP-directed mDia2-dependent F-actin dynamics regulate morphological plasticity in motile cancer cells.

  4. What the Spectrum of Microglial Functions Can Teach us About Fetal Alcohol Spectrum Disorder

    Directory of Open Access Journals (Sweden)

    Elissa L. Wong

    2017-06-01

    Full Text Available Alcohol exposure during gestation can lead to severe defects in brain development and lifelong physical, behavioral and learning deficits that are classified under the umbrella term fetal alcohol spectrum disorder (FASD. Sadly, FASD is diagnosed at an alarmingly high rate, affecting 2%–5% of live births in the United States, making it the most common non-heritable cause of mental disability. Currently, no standard therapies exist that are effective at battling FASD symptoms, highlighting a pressing need to better understand the underlying mechanisms by which alcohol affects the developing brain. While it is clear that sensory and cognitive deficits are driven by inappropriate development and remodeling of the neural circuits that mediate these processes, alcohol’s actions acutely and long-term on the brain milieu are diverse and complex. Microglia, the brain’s immune cells, have been thought to be a target for alcohol during development because of their exquisite ability to rapidly detect and respond to perturbations affecting the brain. Additionally, our view of these immune cells is rapidly changing, and recent studies have revealed a myriad of microglial physiological functions critical for normal brain development and long-term function. A clear and complete understanding of how microglial roles on this end of the spectrum may be altered in FASD is currently lacking. Such information could provide important insights toward novel therapeutic targets for FASD treatment. Here we review the literature that links microglia to neural circuit remodeling and provide a discussion of the current understanding of how developmental alcohol exposure affects microglial behavior in the context of developing brain circuits.

  5. Diverse Requirements for Microglial Survival, Specification, and Function Revealed by Defined-Medium Cultures.

    Science.gov (United States)

    Bohlen, Christopher J; Bennett, F Chris; Tucker, Andrew F; Collins, Hannah Y; Mulinyawe, Sara B; Barres, Ben A

    2017-05-17

    Microglia, the resident macrophages of the CNS, engage in various CNS-specific functions that are critical for development and health. To better study microglia and the properties that distinguish them from other tissue macrophage populations, we have optimized serum-free culture conditions to permit robust survival of highly ramified adult microglia under defined-medium conditions. We find that astrocyte-derived factors prevent microglial death ex vivo and that this activity results from three primary components, CSF-1/IL-34, TGF-β2, and cholesterol. Using microglial cultures that have never been exposed to serum, we demonstrate a dramatic and lasting change in phagocytic capacity after serum exposure. Finally, we find that mature microglia rapidly lose signature gene expression after isolation, and that this loss can be reversed by engrafting cells back into an intact CNS environment. These data indicate that the specialized gene expression profile of mature microglia requires continuous instructive signaling from the intact CNS. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Microglial phagocytosis induced by fibrillar β-amyloid is attenuated by oligomeric β-amyloid: implications for Alzheimer's disease

    Directory of Open Access Journals (Sweden)

    Lin Nan

    2011-06-01

    Full Text Available Abstract Background Reactive microglia are associated with β-amyloid (Aβ deposit and clearance in Alzhiemer's Disease (AD. Paradoxically, entocranial resident microglia fail to trigger an effective phagocytic response to clear Aβ deposits although they mainly exist in an "activated" state. Oligomeric Aβ (oAβ, a recent target in the pathogenesis of AD, can induce more potent neurotoxicity when compared with fibrillar Aβ (fAβ. However, the role of the different Aβ forms in microglial phagocytosis, induction of inflammation and oxidation, and subsequent regulation of phagocytic receptor system, remain unclear. Results We demonstrated that Aβ(1-42 fibrils, not Aβ(1-42 oligomers, increased the microglial phagocytosis. Intriguingly, the pretreatment of microglia with oAβ(1-42 not only attenuated fAβ(1-42-triggered classical phagocytic response to fluorescent microspheres but also significantly inhibited phagocytosis of fluorescent labeled fAβ(1-42. Compared with the fAβ(1-42 treatment, the oAβ(1-42 treatment resulted in a rapid and transient increase in interleukin 1β (IL-1β level and produced higher levels of tumor necrosis factor-α (TNF-α, nitric oxide (NO, prostaglandin E2 (PGE2 and intracellular superoxide anion (SOA. The further results demonstrated that microglial phagocytosis was negatively correlated with inflammatory mediators in this process and that the capacity of phagocytosis in fAβ(1-42-induced microglia was decreased by IL-1β, lippolysaccharide (LPS and tert-butyl hydroperoxide (t-BHP. The decreased phagocytosis could be relieved by pyrrolidone dithiocarbamate (PDTC, a nuclear factor-κB (NF-κB inhibitor, and N-acetyl-L-cysteine (NAC, a free radical scavenger. These results suggest that the oAβ-impaired phagocytosis is mediated through inflammation and oxidative stress-mediated mechanism in microglial cells. Furthermore, oAβ(1-42 stimulation reduced the mRNA expression of CD36, integrin β1 (Itgb1, and Ig

  7. A novel microglial subset plays a key role in myelinogenesis in developing brain

    DEFF Research Database (Denmark)

    Wlodarczyk, Agnieszka; Holtman, Inge; Krueger, Martin

    2017-01-01

    Microglia are resident macrophages of the central nervous system that contribute to homeostasis and neuroinflammation. Although known to play an important role in brain development, their exact function has not been fully described. Here we show that in contrast to healthy adult and inflammation......-activated cells, neonatal microglia show a unique myelinogenic and neurogenic phenotype. A CD11c+ microglial subset that predominates in primary myelinating areas of the developing brain expresses genes for neuronal and glial survival, migration and differentiation. These cells are the major source of insulin...

  8. Glioma-secreted soluble factors stimulate microglial activation: The role of interleukin-1β and tumor necrosis factor-α.

    Science.gov (United States)

    Hwang, Ji-Sun; Jung, Eun-Hye; Kwon, Mi-Youn; Han, Inn-Oc

    2016-09-15

    We aimed to elucidate the effect of soluble factors secreted by glioma on microglial activation. Conditioned medium (CM) from glioma cells, CRT-MG and C6, significantly induced nitric oxide (NO) production and stimulated the mRNA expression of inducible NO synthase (iNOS), interleukin (IL)-1beta, IL-6, tumor necrosis factor-alpha (TNF-α) and cyclooxygenase 2 (COX-2) in BV2 cells. Glioma CM stimulated p38 mitogen-activated protein kinase (MAPK) phosphorylation, and a p38 MAPK inhibitor, SB203580, suppressed CM-induced NO production in BV2 cells. In addition, CM stimulated nuclear factor-kappaB (NF-κB) DNA binding and transcriptional activity, which was repressed by SB203580. Gliomas displayed higher mRNA expression and release of TNF-α and IL-1β than primary astrocyte cells. Neutralization of TNF-α and IL-1β in C6-CM using a neutralizing antibody inhibited NO/iNOS expression in BV-2 cells. These results indicate potential contribution of diffusible tumor-derived factors to regulate microglial activation and subsequent tumor microenvironment. Copyright © 2016. Published by Elsevier B.V.

  9. microRNA-34a-Mediated Down-Regulation of the Microglial-Enriched Triggering Receptor and Phagocytosis-Sensor TREM2 in Age-Related Macular Degeneration.

    Directory of Open Access Journals (Sweden)

    Surjyadipta Bhattacharjee

    Full Text Available The aggregation of Aβ42-peptides and the formation of drusen in age-related macular degeneration (AMD are due in part to the inability of homeostatic phagocytic mechanisms to clear self-aggregating Aβ42-peptides from the extracellular space. The triggering receptor expressed in myeloid/microglial cells-2 (TREM2, a trans-membrane-spanning, sensor-receptor of the immune-globulin/lectin-like gene superfamily is a critical component of Aβ42-peptide clearance. Here we report a significant deficit in TREM2 in AMD retina and in cytokine- or oxidatively-stressed microglial (MG cells. RT-PCR, miRNA-array, LED-Northern and Western blot studies indicated up-regulation of a microglial-enriched NF-кB-sensitive miRNA-34a coupled to a down-regulation of TREM2 in the same samples. Bioinformatics/transfection-luciferase reporter assays indicated that miRNA-34a targets the 299 nucleotide TREM2-mRNA-3'UTR, resulting in TREM2 down-regulation. C8B4-microglial cells challenged with Aβ42 were able to phagocytose these peptides, while miRNA-34a down-regulated both TREM2 and the ability of microglial-cells to phagocytose. Treatment of TNFα-stressed MG cells with phenyl-butyl nitrone (PBN, caffeic-acid phenethyl ester (CAPE, the NF-kB - [corrected] inhibitor/resveratrol analog CAY10512 or curcumin abrogated these responses. Incubation of anti-miRNA-34a (AM-34a normalized miRNA-34a abundance and restored TREM2 back to homeostatic levels. These data support five novel observations: (i that a ROS- and NF-kB - [corrected] sensitive, miRNA-34a-mediated modulation of TREM2 may in part regulate the phagocytic response; (ii that gene products encoded on two different chromosomes (miRNA-34a at chr1q36.22 and TREM2 at chr6p21.1 orchestrate a phagocytic-Aβ42-peptide clearance-system; (iii that this NF-kB-mediated-miRNA-34a-TREM2 mechanism is inducible from outside of the cell; (iv that when operating normally, this pathway can clear Aβ42 peptide monomers from the

  10. CCL2/MCP-1 modulation of microglial activation and proliferation

    Directory of Open Access Journals (Sweden)

    Garcia-Bueno Borja

    2011-07-01

    Full Text Available Abstract Background Monocyte chemoattractant protein (CCL2/MCP-1 is a chemokine that attracts cells involved in the immune/inflammatory response. As microglia are one of the main cell types sustaining inflammation in brain, we proposed here to analyze the direct effects of MCP-1 on cultured primary microglia. Methods Primary microglia and neuronal cultures were obtained from neonatal and embryonic Wistar rats, respectively. Microglia were incubated with different concentrations of recombinant MCP-1 and LPS. Cell proliferation was quantified by measuring incorporation of bromodeoxyuridine (BrdU. Nitrite accumulation was measured using the Griess assay. The expression and synthesis of different proteins was measured by RT-PCR and ELISA. Cell death was quantified by measuring release of LDH into the culture medium. Results MCP-1 treatment (50 ng/ml, 24 h did not induce morphological changes in microglial cultures. Protein and mRNA levels of different cytokines were measured, showing that MCP-1 was not able to induce proinflammatory cytokines (IL-1β, IL6, MIP-1α, either by itself or in combination with LPS. A similar lack of effect was observed when measuring inducible nitric oxide synthase (NOS2 expression or accumulation of nitrites in the culture media as a different indicator of microglial activation. MCP-1 was also unable to alter the expression of different trophic factors that were reduced by LPS treatment. In order to explore the possible release of other products by microglia and their potential neurotoxicity, neurons were co-cultured with microglia: no death of neurons could be detected when treated with MCP-1. However, the presence of MCP-1 induced proliferation of microglia, an effect opposite to that observed with LPS. Conclusion These data indicate that, while causing migration and proliferation of microglia, MCP-1 does not appear to directly activate an inflammatory response in this cell type, and therefore, other factors may be

  11. The ROCK isoforms differentially regulate the morphological characteristics of carcinoma cells.

    Science.gov (United States)

    Jerrell, Rachel J; Leih, Mitchell J; Parekh, Aron

    2017-06-26

    Rho-associated kinase (ROCK) activity drives cell migration via actomyosin contractility. During invasion, individual cancer cells can transition between 2 modes of migration, mesenchymal and amoeboid. Changes in ROCK activity can cause a switch between these migration phenotypes which are defined by distinct morphologies. However, recent studies have shown that the ROCK isoforms are not functionally redundant as previously thought. Therefore, it is unclear whether the ROCK isoforms play different roles in regulating migration phenotypes. Here, we found that ROCK1 and ROCK2 differentially regulate carcinoma cell morphology resulting in intermediate phenotypes that share some mesenchymal and amoeboid characteristics. These findings suggest that the ROCK isoforms play unique roles in the phenotypic plasticity of mesenchymal carcinoma cells which may have therapeutic implications.

  12. Activation of glucocorticoid receptors in Müller glia is protective to retinal neurons and suppresses microglial reactivity.

    Science.gov (United States)

    Gallina, Donika; Zelinka, Christopher Paul; Cebulla, Colleen M; Fischer, Andy J

    2015-11-01

    Reactive microglia and macrophages are prevalent in damaged retinas. Glucocorticoid signaling is known to suppress inflammation and the reactivity of microglia and macrophages. In the vertebrate retina, the glucocorticoid receptor (GCR) is known to be activated and localized to the nuclei of Müller glia (Gallina et al., 2014). Accordingly, we investigated how signaling through GCR influences the survival of neurons using the chick retina in vivo as a model system. We applied intraocular injections of GCR agonist or antagonist, assessed microglial reactivity, and the survival of retinal neurons following different damage paradigms. Microglial reactivity was increased in retinas from eyes that were injected with vehicle, and this reactivity was decreased by GCR-agonist dexamethasone (Dex) and increased by GCR-antagonist RU486. We found that activation of GCR suppresses the reactivity of microglia and inhibited the loss of retinal neurons resulting from excitotoxicity. We provide evidence that the protection-promoting effects of Dex were maintained when the microglia were selectively ablated. Similarly, intraocular injections of Dex protected ganglion cells from colchicine-treatment and protected photoreceptors from damage caused by retinal detachment. We conclude that activation of GCR promotes the survival of ganglion cells in colchicine-damaged retinas, promotes the survival of amacrine and bipolar cells in excitotoxin-damaged retinas, and promotes the survival of photoreceptors in detached retinas. We propose that suppression of microglial reactivity is secondary to activation of GCR in Müller glia, and this mode of signaling is an effective means to lessen the damage and vision loss resulting from different types of retinal damage. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Sulforaphane Inhibits Lipopolysaccharide-Induced Inflammation, Cytotoxicity, Oxidative Stress, and miR-155 Expression and Switches to Mox Phenotype through Activating Extracellular Signal-Regulated Kinase 1/2-Nuclear Factor Erythroid 2-Related Factor 2/Antioxidant Response Element Pathway in Murine Microglial Cells.

    Science.gov (United States)

    Eren, Erden; Tufekci, Kemal Ugur; Isci, Kamer Burak; Tastan, Bora; Genc, Kursad; Genc, Sermin

    2018-01-01

    Sulforaphane (SFN) is a natural product with cytoprotective, anti-inflammatory, and antioxidant effects. In this study, we evaluated the mechanisms of its effects on lipopolysaccharide (LPS)-induced cell death, inflammation, oxidative stress, and polarization in murine microglia. We found that SFN protects N9 microglial cells upon LPS-induced cell death and suppresses LPS-induced levels of secreted pro-inflammatory cytokines, tumor necrosis factor-alpha, interleukin-1 beta, and interleukin-6. SFN is also a potent inducer of redox sensitive transcription factor, nuclear factor erythroid 2-related factor 2 (Nrf2), which is responsible for the transcription of antioxidant, cytoprotective, and anti-inflammatory genes. SFN induced translocation of Nrf2 to the nucleus via extracellular signal-regulated kinase 1/2 (ERK1/2) pathway activation. siRNA-mediated knockdown study showed that the effects of SFN on LPS-induced reactive oxygen species, reactive nitrogen species, and pro-inflammatory cytokine production and cell death are partly Nrf2 dependent. Mox phenotype is a novel microglial phenotype that has roles in oxidative stress responses. Our results suggested that SFN induced the Mox phenotype in murine microglia through Nrf2 pathway. SFN also alleviated LPS-induced expression of inflammatory microRNA, miR-155. Finally, SFN inhibits microglia-mediated neurotoxicity as demonstrated by conditioned medium and co-culture experiments. In conclusion, SFN exerts protective effects on microglia and modulates the microglial activation state.

  14. The PPARα Agonist Fenofibrate Preserves Hippocampal Neurogenesis and Inhibits Microglial Activation After Whole-Brain Irradiation

    International Nuclear Information System (INIS)

    Ramanan, Sriram; Kooshki, Mitra; Zhao Weiling; Hsu, F.-C.; Riddle, David R.; Robbins, Mike E.

    2009-01-01

    Purpose: Whole-brain irradiation (WBI) leads to cognitive impairment months to years after radiation. Numerous studies suggest that decreased hippocampal neurogenesis and microglial activation are involved in the pathogenesis of WBI-induced brain injury. The goal of this study was to investigate whether administration of the peroxisomal proliferator-activated receptor (PPAR) α agonist fenofibrate would prevent the detrimental effect of WBI on hippocampal neurogenesis. Methods and Materials: For this study, 129S1/SvImJ wild-type and PPARα knockout mice that were fed either regular or 0.2% wt/wt fenofibrate-containing chow received either sham irradiation or WBI (10-Gy single dose of 137 Cs γ-rays). Mice were injected intraperitoneally with bromodeoxyuridine to label the surviving cells at 1 month after WBI, and the newborn neurons were counted at 2 months after WBI by use of bromodeoxyuridine/neuronal nuclei double immunofluorescence. Proliferation in the subgranular zone and microglial activation were measured at 1 week and 2 months after WBI by use of Ki-67 and CD68 immunohistochemistry, respectively. Results: Whole-brain irradiation led to a significant decrease in the number of newborn hippocampal neurons 2 months after it was performed. Fenofibrate prevented this decrease by promoting the survival of newborn cells in the dentate gyrus. In addition, fenofibrate treatment was associated with decreased microglial activation in the dentate gyrus after WBI. The neuroprotective effects of fenofibrate were abolished in the knockout mice, indicating a PPARα-dependent mechanism or mechanisms. Conclusions: These data highlight a novel role for PPARα ligands in improving neurogenesis after WBI and offer the promise of improving the quality of life for brain cancer patients receiving radiotherapy.

  15. Spinal Microgliosis Due to Resident Microglial Proliferation Is Required for Pain Hypersensitivity after Peripheral Nerve Injury

    Directory of Open Access Journals (Sweden)

    Nan Gu

    2016-07-01

    Full Text Available Peripheral nerve injury causes neuropathic pain accompanied by remarkable microgliosis in the spinal cord dorsal horn. However, it is still debated whether infiltrated monocytes contribute to injury-induced expansion of the microglial population. Here, we found that spinal microgliosis predominantly results from local proliferation of resident microglia but not from infiltrating monocytes after spinal nerve transection (SNT by using two genetic mouse models (CCR2RFP/+:CX3CR1GFP/+ and CX3CR1creER/+:R26tdTomato/+ mice as well as specific staining of microglia and macrophages. Pharmacological inhibition of SNT-induced microglial proliferation correlated with attenuated neuropathic pain hypersensitivities. Microglial proliferation is partially controlled by purinergic and fractalkine signaling, as CX3CR1−/− and P2Y12−/− mice show reduced spinal microglial proliferation and neuropathic pain. These results suggest that local microglial proliferation is the sole source of spinal microgliosis, which represents a potential therapeutic target for neuropathic pain management.

  16. Aging increases microglial proliferation, delays cell migration, and decreases cortical neurogenesis after focal cerebral ischemia.

    Science.gov (United States)

    Moraga, Ana; Pradillo, Jesús M; García-Culebras, Alicia; Palma-Tortosa, Sara; Ballesteros, Ivan; Hernández-Jiménez, Macarena; Moro, María A; Lizasoain, Ignacio

    2015-05-10

    Aging is not just a risk factor of stroke, but it has also been associated with poor recovery. It is known that stroke-induced neurogenesis is reduced but maintained in the aged brain. However, there is no consensus on how neurogenesis is affected after stroke in aged animals. Our objective is to determine the role of aging on the process of neurogenesis after stroke. We have studied neurogenesis by analyzing proliferation, migration, and formation of new neurons, as well as inflammatory parameters, in a model of cerebral ischemia induced by permanent occlusion of the middle cerebral artery in young- (2 to 3 months) and middle-aged mice (13 to 14 months). Aging increased both microglial proliferation, as shown by a higher number of BrdU(+) cells and BrdU/Iba1(+) cells in the ischemic boundary and neutrophil infiltration. Interestingly, aging increased the number of M1 monocytes and N1 neutrophils, consistent with pro-inflammatory phenotypes when compared with the alternative M2 and N2 phenotypes. Aging also inhibited (subventricular zone) SVZ cell proliferation by decreasing both the number of astrocyte-like type-B (prominin-1(+)/epidermal growth factor receptor (EGFR)(+)/nestin(+)/glial fibrillary acidic protein (GFAP)(+) cells) and type-C cells (prominin-1(+)/EGFR(+)/nestin(-)/Mash1(+) cells), and not affecting apoptosis, 1 day after stroke. Aging also inhibited migration of neuroblasts (DCX(+) cells), as indicated by an accumulation of neuroblasts at migratory zones 14 days after injury; consistently, aged mice presented a smaller number of differentiated interneurons (NeuN(+)/BrdU(+) and GAD67(+) cells) in the peri-infarct cortical area 14 days after stroke. Our data confirm that stroke-induced neurogenesis is maintained but reduced in aged animals. Importantly, we now demonstrate that aging not only inhibits proliferation of specific SVZ cell subtypes but also blocks migration of neuroblasts to the damaged area and decreases the number of new interneurons in

  17. Disruption of Fractalkine Signaling Leads to Microglial Activation and Neuronal Damage in the Diabetic Retina

    Directory of Open Access Journals (Sweden)

    Sandra M. Cardona

    2015-10-01

    Full Text Available Fractalkine (CX3CL1 or FKN is a membrane-bound chemokine expressed on neuronal membranes and is proteolytically cleaved to shed a soluble chemoattractant domain. FKN signals via its unique receptor CX3CR1 expressed on microglia and other peripheral leukocytes. The aim of this study is to determine the role of CX3CR1 in inflammatory-mediated damage to retinal neurons using a model of diabetic retinopathy. For this, we compared neuronal, microglial, and astroglial densities and inflammatory response in nondiabetic and diabetic (Ins2Akita CX3CR1-wild-type and CX3CR1-deficient mice at 10 and 20 weeks of age. Our results show that Ins2Akita CX3CR1-knockout mice exhibited (a decreased neuronal cell counts in the retinal ganglion cell layer, (b increased microglial cell numbers, and (c decreased astrocyte responses comparable with Ins2Akita CX3CR1-Wild-type mice at 20 weeks of age. Analyses of the inflammatory response using PCR arrays showed several inflammatory genes differentially regulated in diabetic tissues. From those, the response in Ins2Akita CX3CR1-deficient mice at 10 weeks of age revealed a significant upregulation of IL-1β at the transcript level that was confirmed by enzyme-linked immunosorbent assay in soluble retinal extracts. Overall, IL-1β, VEGF, and nitrite levels as a read out of nitric oxide production were abundant in Ins2Akita CX3CR1-deficient retina. Notably, double immunofluorescence staining shows that astrocytes act as a source of IL-1β in the Ins2Akita retina, and CX3CR1-deficient microglia potentiate the inflammatory response via IL-1β release. Collectively, these data demonstrate that dysregulated microglial responses in absence of CX3CR1 contribute to inflammatory-mediated damage of neurons in the diabetic retina.

  18. Alginate-Derived Oligosaccharide Inhibits Neuroinflammation and Promotes Microglial Phagocytosis of β-Amyloid

    Directory of Open Access Journals (Sweden)

    Rui Zhou

    2015-09-01

    Full Text Available Alginate from marine brown algae has been widely applied in biotechnology. In this work, the effects of alginate-derived oligosaccharide (AdO on lipopolysaccharide (LPS/β-amyloid (Aβ-induced neuroinflammation and microglial phagocytosis of Aβ were studied. We found that pretreatment of BV2 microglia with AdO prior to LPS/Aβ stimulation led to a significant inhibition of production of nitric oxide (NO and prostaglandin E2 (PGE2, expression of inducible nitric oxide synthase (iNOS and cyclooxygenase-2 (COX-2 and secretion of proinflammatory cytokines. We further demonstrated that AdO remarkably attenuated the LPS-activated overexpression of toll-like receptor 4 (TLR4 and nuclear factor (NF-κB in BV2 cells. In addition to the impressive inhibitory effect on neuroinflammation, we also found that AdO promoted the phagocytosis of Aβ through its interaction with TLR4 in microglia. Our results suggested that AdO exerted the inhibitory effect on neuroinflammation and the promotion effect on microglial phagocytosis, indicating its potential as a nutraceutical or therapeutic agent for neurodegenerative diseases, particularly Alzheimer’s disease (AD.

  19. TMEM16F Regulates Spinal Microglial Function in Neuropathic Pain States

    Directory of Open Access Journals (Sweden)

    Laura Batti

    2016-06-01

    Full Text Available Neuropathic pain is a widespread chronic pain state that results from injury to the nervous system. Spinal microglia play a causative role in the pathogenesis of neuropathic pain through secretion of growth factors and cytokines. Here, we investigated the contribution of TMEM16F, a protein that functions as a Ca2+-dependent ion channel and a phospholipid scramblase, to microglial activity during neuropathic pain. We demonstrate that mice with a conditional ablation of TMEM16F in microglia do not develop mechanical hypersensitivity upon nerve injury. In the absence of TMEM16F, microglia display deficits in process motility and phagocytosis. Moreover, loss of GABA immunoreactivity upon injury is spared in TMEM16F conditional knockout mice. Collectively, these data indicate that TMEM16F is an essential component of the microglial response to injury and suggest the importance of microglial phagocytosis in the pathogenesis of neuropathic pain.

  20. Ingression-type cell migration drives vegetal endoderm internalisation in the Xenopus gastrula.

    Science.gov (United States)

    Wen, Jason Wh; Winklbauer, Rudolf

    2017-08-10

    During amphibian gastrulation, presumptive endoderm is internalised as part of vegetal rotation, a large-scale movement that encompasses the whole vegetal half of the embryo. It has been considered a gastrulation process unique to amphibians, but we show that at the cell level, endoderm internalisation exhibits characteristics reminiscent of bottle cell formation and ingression, known mechanisms of germ layer internalisation. During ingression proper, cells leave a single-layered epithelium. In vegetal rotation, the process occurs in a multilayered cell mass; we refer to it as ingression-type cell migration. Endoderm cells move by amoeboid shape changes, but in contrast to other instances of amoeboid migration, trailing edge retraction involves ephrinB1-dependent macropinocytosis and trans -endocytosis. Moreover, although cells are separated by wide gaps, they are connected by filiform protrusions, and their migration depends on C-cadherin and the matrix protein fibronectin. Cells move in the same direction but at different velocities, to rearrange by differential migration.

  1. Inhibition of lipopolysaccharide-induced proinflammatory responses by Buddleja officinalis extract in BV-2 microglial cells via negative regulation of NF-kB and ERK1/2 signaling.

    Science.gov (United States)

    Oh, Won-Jun; Jung, Uhee; Eom, Hyun-Soo; Shin, Hee-June; Park, Hae-Ran

    2013-07-31

    Buddleja officinalis has been traditionally used in the supportive treatment of inflammatory and neuronal diseases in Korea and China. Although several reports have shown the anti-inflammatory effects of Buddleja officinalis, the anti-neuroinflammatory effect has remained unclear. In this study, we aimed to investigate the inhibitory effects of flower buds of B. officinalis Maximowicz water extract (BOWE) on LPS-induced inflammatory processes in BV-2 microglial cells. BOWE dose-dependently inhibited the production of nitric oxide as well as iNOS mRNA expression. Moreover, BOWE prevented IL-1β and IL-6 mRNA expression. However, BOWE had no effect on LPS-induced COX-2 or TNF-a mRNA expression. The extract also had no effect on LPS-stimulated p38 MAPK, JNK, and c-Jun phosphorylation, whereas ERK1/2 phosphorylation was strongly inhibited by BOWE. BOWE also inhibited the LPS-induced degradation of IkB-α, and LPS-induced phosphorylation of p65 NF-kB protein. These data indicate that BOWE inhibited the nitric oxide production and pro-inflammatory gene expression in BV-2 microglial cells, possibly through a negative regulation of the NF-kB and ERK1/2 pathways. Further identification of the direct target molecule(s) of BOWE is required to support its use as an anti-neuroinflammatory agent against the neurodegenerative disorders.

  2. Inhibition of Lipopolysaccharide-Induced Proinflammatory Responses by Buddleja officinalis Extract in BV-2 Microglial Cells via Negative Regulation of NF-kB and ERK1/2 Signaling

    Directory of Open Access Journals (Sweden)

    Hae-Ran Park

    2013-07-01

    Full Text Available Buddleja officinalis has been traditionally used in the supportive treatment of inflammatory and neuronal diseases in Korea and China. Although several reports have shown the anti-inflammatory effects of Buddleja officinalis, the anti-neuroinflammatory effect has remained unclear. In this study, we aimed to investigate the inhibitory effects of flower buds of B. officinalis Maximowicz water extract (BOWE on LPS-induced inflammatory processes in BV-2 microglial cells. BOWE dose-dependently inhibited the production of nitric oxide as well as iNOS mRNA expression. Moreover, BOWE prevented IL-1β and IL-6 mRNA expression. However, BOWE had no effect on LPS-induced COX-2 or TNF-a mRNA expression. The extract also had no effect on LPS-stimulated p38 MAPK, JNK, and c-Jun phosphorylation, whereas ERK1/2 phosphorylation was strongly inhibited by BOWE. BOWE also inhibited the LPS-induced degradation of IkB-α, and LPS-induced phosphorylation of p65 NF-kB protein. These data indicate that BOWE inhibited the nitric oxide production and pro-inflammatory gene expression in BV-2 microglial cells, possibly through a negative regulation of the NF-kB and ERK1/2 pathways. Further identification of the direct target molecule(s of BOWE is required to support its use as an anti-neuroinflammatory agent against the neurodegenerative disorders.

  3. IFNgamma enhances microglial reactions to hippocampal axonal degeneration

    DEFF Research Database (Denmark)

    Jensen, M B; Hegelund, I V; Lomholt, N D

    2000-01-01

    periods. Message for the immune cytokine interferon-gamma (IFNgamma) was undetectable, and glial reactivity to axonal lesions occurred as normal in IFNgamma-deficient mice. Microglial responses to lesion-induced neuronal injury were markedly enhanced in myelin basic protein promoter-driven transgenic mice...

  4. Evaluation of the Effect of Fingolimod Treatment on Microglial Activation Using Serial PET Imaging in Multiple Sclerosis.

    Science.gov (United States)

    Sucksdorff, Marcus; Rissanen, Eero; Tuisku, Jouni; Nuutinen, Salla; Paavilainen, Teemu; Rokka, Johanna; Rinne, Juha; Airas, Laura

    2017-10-01

    Traditionally, multiple sclerosis (MS) has been considered a white matter disease with focal inflammatory lesions. It is, however, becoming clear that significant pathology, such as microglial activation, also takes place outside the plaque areas, that is, in areas of normal-appearing white matter (NAWM) and gray matter (GM). Microglial activation can be detected in vivo using 18-kDa translocator protein (TSPO)-binding radioligands and PET. It is unknown whether fingolimod affects microglial activation in MS. The aim of this study was to investigate whether serial PET can be used to evaluate the effect of fingolimod treatment on microglial activation. Methods: Ten relapsing-remitting MS patients were studied using the TSPO radioligand 11 C-( R )-PK11195. Imaging was performed at baseline and after 8 and 24 wk of fingolimod treatment. Eight healthy individuals were imaged for comparison. Microglial activation was evaluated as distribution volume ratio of 11 C-( R )-PK11195. Results: The patients had MS for an average of 7.9 ± 4.3 y (mean ± SD), their total relapses averaged 4 ± 2.4, and their Expanded Disability Status Scale was 2.7 ± 0.5. The patients were switched to fingolimod because of safety reasons or therapy escalation. The mean washout period before the initiation of fingolimod was 2.3 ± 1.1 mo. The patients were clinically stable on fingolimod. At baseline, microglial activation was significantly higher in the combined NAWM and GM areas of MS patients than in healthy controls ( P = 0.021). 11 C-( R )-PK11195 binding was reduced (-12.31%) within the combined T2 lesion area after 6 mo of fingolimod treatment ( P = 0.040) but not in the areas of NAWM or GM. Conclusion: Fingolimod treatment reduced microglial/macrophage activation at the site of focal inflammatory lesions, presumably by preventing leukocyte trafficking from the periphery. It did not affect the widespread, diffuse microglial activation in the NAWM and GM. The study opens new vistas for

  5. Minocycline Effects on IL-6 Concentration in Macrophage and Microglial Cells in a Rat Model of Neuropathic Pain.

    Science.gov (United States)

    Moini-Zanjani, Taraneh; Ostad, Seyed-Nasser; Labibi, Farzaneh; Ameli, Haleh; Mosaffa, Nariman; Sabetkasaei, Masoumeh

    2016-11-01

    Evidence indicates that neuropathic pain pathogenesis is not confined to changes in the activity of neuronal systems but involves interactions between neurons, inflammatory immune and immune-like glial cells. Substances released from immune cells during inflammation play an important role in development and maintenance of neuropathic pain. It has been found that minocycline suppresses the development of neuropathic pain. Here, we evaluated the analgesic effect of minocycline in a chronic constriction injury (CCI) model of neuropathic pain in rat and assessed IL-6 concentration from cultured macrophage and microglia cells. Male Wistar rat (n=6, 150-200 g) were divided into three different groups: 1) CCI+vehicle, 2) sham+vehicle, and 3) CCI+drug. Minocycline (10, 20, and 40 mg/kg) was injected one hour before surgery and continued daily to day 14 post ligation. Von Frey filaments and acetone, as pain behavioral tests, were used for mechanical allodynia and cold allodynia, respectively. Experiments were performed on day 0 (before surgery) and days 1, 3, 5, 7, 10, and 14 post -injury. At day 14, rats were killed and monocyte-derived macrophage from right ventricle and microglia from lumbar part of the spinal cord were isolated and cultured in RPMI and Leibovitz's media, respectively. IL-6 concentration was evaluated in cell culture supernatant after 24 h. Minocycline (10, 20, and 40 mg/kg) attenuated pain behavior, and a decrease in IL-6 concentration was observed in immune cells compared to CCI vehicle-treated animals. Minocycline reduced pain behavior and decreased IL-6 concentration in macrophage and microglial cells.

  6. HSP60 mediates the neuroprotective effects of curcumin by suppressing microglial activation.

    Science.gov (United States)

    Ding, Feijia; Li, Fan; Li, Yunhong; Hou, Xiaolin; Ma, Yi; Zhang, Nan; Ma, Jiao; Zhang, Rui; Lang, Bing; Wang, Hongyan; Wang, Yin

    2016-08-01

    Curcumin has anti-inflammatory and antioxidant properties and has been widely used to treat or prevent neurodegenerative diseases. However, the mechanisms underlying the neuroprotective effects of curcumin are not well known. In the present study, the effect of curcumin on lipopolysaccharide (LPS)-stimulated BV2 mouse microglia cells was investigated using enzyme-linked immunosorbent assays of the culture medium and western blotting of cell lysates. The results showed that curcumin significantly inhibited the LPS-induced expression and release of heat shock protein 60 (HSP60) in the BV2 cells. The level of heat shock factor (HSF)-1 was upregulated in LPS-activated BV2 microglia, indicating that the increased expression of HSP60 was driven by HSF-1 activation. However, the increased HSF-1 level was downregulated by curcumin. Extracellular HSP60 is a ligand of Toll-like receptor 4 (TLR-4), and the level of the latter was increased in the LPS-activated BV2 microglia and inhibited by curcumin. The activation of TLR-4 is known to be associated with the activation of myeloid differentiation primary response 88 (MyD88) and nuclear factor (NF)-κB, with the subsequent production of proinflammatory and neurotoxic factors. In the present study, curcumin demonstrated marked suppression of the LPS-induced expression of MyD88, NF-κB, caspase-3, inducible nitric oxide synthase, tumor necrosis factor-α, interleukin (IL)-1β and IL-6 in the microglia. These results indicate that curcumin may exert its neuroprotective and anti-inflammatory effects by inhibiting microglial activation through the HSP60/TLR-4/MyD88/NF-κB signaling wpathway. Therefore, curcumin may be useful for the treatment of neurodegenerative diseases that are associated with microglial activation.

  7. Kaempferol acts through mitogen-activated protein kinases and protein kinase B/AKT to elicit protection in a model of neuroinflammation in BV2 microglial cells

    Science.gov (United States)

    Park, SE; Sapkota, K; Kim, S; Kim, H; Kim, SJ

    2011-01-01

    BACKGROUND AND PURPOSE Kaempferol, a dietary flavonoid and phyto-oestrogen, is known to have anti-inflammatory properties. Microglial activation has been implicated in various neurodegenerative diseases. Anti-inflammatory effects of kaempferol and the underlying mechanisms were investigated by using LPS-stimulated microglial BV2 cells. EXPERIMENTAL APPROACH Cell viability was measured using MTT and neutral red assays. elisa, Western blot, immunocytochemistry and electrophoretic mobility-shift assay were used to analyse NO, PGE2, TNF-α and IL-1β production, inducible NOS (iNOS), COX-2 expression and the involvement of signalling pathways such as toll-like receptor-4 (TLR4), MAPK cascades, PKB (AKT) and NF-κB. Accumulation of reaction oxygen species (ROS) was measured by nitroblue tetrazolium and 2′7′-dichlorofluorescein diacetate assay. Matrix metalloproteinase activity was investigated by zymography and immunoblot assay. Phagocytotic activity was assessed by use of latex beads. KEY RESULTS Kaempferol significantly attenuated LPS-induced NO, PGE2, TNF-α, IL-1β and ROS production and phagocytosis in a concentration-dependent manner. Kaempferol suppressed the expression of iNOS, COX-2, MMP-3 and blocked the TLR4 activation. Moreover, kaempferol inhibited LPS-induced NF-κB activation and p38 MAPK, JNK and AKT phosphorylation. CONCLUSION AND IMPLICATIONS Kaempferol was able to reduce LPS-induced inflammatory mediators through the down-regulation of TLR4, NF-κB, p38 MAPK, JNK and AKT suggesting that kaempferol has therapeutic potential for the treatment of neuroinflammatory diseases. PMID:21449918

  8. Genetic deletion of P-glycoprotein alters stress responsivity and increases depression-like behavior, social withdrawal and microglial activation in the hippocampus of female mice.

    Science.gov (United States)

    Brzozowska, Natalia I; Smith, Kristie L; Zhou, Cilla; Waters, Peter M; Cavalcante, Ligia Menezes; Abelev, Sarah V; Kuligowski, Michael; Clarke, David J; Todd, Stephanie M; Arnold, Jonathon C

    2017-10-01

    P-glycoprotein (P-gp) is an ABC transporter expressed at the blood brain barrier and regulates the brain uptake of various xenobiotics and endogenous mediators including glucocorticoid hormones which are critically important to the stress response. Moreover, P-gp is expressed on microglia, the brain's immune cells, which are activated by stressors and have an emerging role in psychiatric disorders. We therefore hypothesised that germline P-gp deletion in mice might alter the behavioral and microglial response to stressors. Female P-gp knockout mice displayed an unusual, frantic anxiety response to intraperitoneal injection stress in the light-dark test. They also tended to display reduced conditioned fear responses compared to wild-type (WT) mice in a paradigm where a single electric foot-shock stressor was paired to a context. Foot-shock stress reduced social interaction and decreased microglia cell density in the amygdala which was not varied by P-gp genotype. Independently of stressor exposure, female P-gp deficient mice displayed increased depression-like behavior, idiosyncratic darting behavior, age-related social withdrawal and hyperactivity, facilitated sensorimotor gating and altered startle reactivity. In addition, P-gp deletion increased microglia cell density in the CA3 region of the hippocampus, and the microglial cells exhibited a reactive, hypo-ramified morphology. Further, female P-gp KO mice displayed increased glucocorticoid receptor (GR) expression in the hippocampus. In conclusion, this research shows that germline P-gp deletion affected various behaviors of relevance to psychiatric conditions, and that altered microglial cell activity and enhanced GR expression in the hippocampus may play a role in mediating these behaviors. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Chronic intermittent hypoxia exerts CNS region-specific effects on rat microglial inflammatory and TLR4 gene expression.

    Directory of Open Access Journals (Sweden)

    Stephanie M C Smith

    Full Text Available Intermittent hypoxia (IH during sleep is a hallmark of sleep apnea, causing significant neuronal apoptosis, and cognitive and behavioral deficits in CNS regions underlying memory processing and executive functions. IH-induced neuroinflammation is thought to contribute to cognitive deficits after IH. In the present studies, we tested the hypothesis that IH would differentially induce inflammatory factor gene expression in microglia in a CNS region-dependent manner, and that the effects of IH would differ temporally. To test this hypothesis, adult rats were exposed to intermittent hypoxia (2 min intervals of 10.5% O2 for 8 hours/day during their respective sleep cycles for 1, 3 or 14 days. Cortex, medulla and spinal cord tissues were dissected, microglia were immunomagnetically isolated and mRNA levels of the inflammatory genes iNOS, COX-2, TNFα, IL-1β and IL-6 and the innate immune receptor TLR4 were compared to levels in normoxia. Inflammatory gene expression was also assessed in tissue homogenates (containing all CNS cells. We found that microglia from different CNS regions responded to IH differently. Cortical microglia had longer lasting inflammatory gene expression whereas spinal microglial gene expression was rapid and transient. We also observed that inflammatory gene expression in microglia frequently differed from that in tissue homogenates from the same region, indicating that cells other than microglia also contribute to IH-induced neuroinflammation. Lastly, microglial TLR4 mRNA levels were strongly upregulated by IH in a region- and time-dependent manner, and the increase in TLR4 expression appeared to coincide with timing of peak inflammatory gene expression, suggesting that TLR4 may play a role in IH-induced neuroinflammation. Together, these data indicate that microglial-specific neuroinflammation may play distinct roles in the effects of intermittent hypoxia in different CNS regions.

  10. Human neural progenitor cell engraftment increases neurogenesis and microglial recruitment in the brain of rats with stroke.

    Directory of Open Access Journals (Sweden)

    Zahra Hassani

    Full Text Available Stem cell transplantation is to date one of the most promising therapies for chronic ischemic stroke. The human conditionally immortalised neural stem cell line, CTX0E03, has demonstrable efficacy in a rodent model of stroke and is currently in clinical trials. Nonetheless, the mechanisms by which it promotes brain repair are not fully characterised. This study investigated the cellular events occurring after CTX0E03 transplantation in the brains of rats that underwent ischemic stroke.We focused on the endogenous proliferative activity of the host brain in response to cell transplantation and determined the identity of the proliferating cells using markers for young neurons (doublecortin, Dcx and microglia (CD11b. So as to determine the chronology of events occurring post-transplantation, we analysed the engrafted brains one week and four weeks post-transplantation.We observed a significantly greater endogenous proliferation in the striatum of ischemic brains receiving a CTX0E03 graft compared to vehicle-treated ischemic brains. A significant proportion of these proliferative cells were found to be Dcx+ striatal neuroblasts. Further, we describe an enhanced immune response after CTX0E03 engraftment, as shown by a significant increase of proliferating CD11b+ microglial cells.Our study demonstrates that few Dcx+ neuroblasts are proliferative in normal conditions, and that this population of proliferative neuroblasts is increased in response to stroke. We further show that CTX0E03 transplantation after stroke leads to the maintenance of this proliferative activity. Interestingly, the preservation of neuronal proliferative activity upon CTX0E03 transplantation is preceded and accompanied by a high rate of proliferating microglia. Our study suggests that microglia might mediate in part the effect of CTX0E03 transplantation on neuronal proliferation in ischemic stroke conditions.

  11. Influence of CSN1S2 protein from Caprine milk Etawah Breed (EB) on histology of microglial cells in rat (Rattus norvegicus) Type-2 diabetes mellitus (T2DM)

    Science.gov (United States)

    Rika, Margareth; Fatchiyah

    2017-11-01

    Type-2 diabetes mellitus (T2DM) is a degenerative disease that causes an imbalance in the metabolism. The aim of this research is to determine the influences of CSN1S2 on the structure of microglial cells in T2DM. Rats (Rattus norvegicus) were divided into eight groups of treatment with looping three times each between treatment groups (CM) Control. The control is given a milk treatment with doses of 375 mg/kg (CM375), 750 mg/kg (CM750), and 1500 mg/kg (CM1500), T2DM (DMK), and T2DM with CSN1S2 375 mg/kg dose (DM375), 750mg/kg (DM750), and 1500 mg/kg (DM1500). The animal model T2DM was induced by a high-fat diet in the form of feed followed by injection of STZ (dose of 25 mg/kg of animal treatment) and treatment of CSN1S2 for 28 days. Brain organs were taken and analysed in histopathology stained by Hematoxylin-eosin (HE) and observed using Olympus BX53. Based on the results, it was concluded that CSN1S2 protein is influential for induction of microglial cell proliferation in animal models of T2DM, as immunity responds to the inflammatory condition in T2DM.

  12. Trans-caryophyllene inhibits amyloid β (Aβ) oligomer-induced neuroinflammation in BV-2 microglial cells.

    Science.gov (United States)

    Hu, Yawei; Zeng, Ziling; Wang, Baojie; Guo, Shougang

    2017-10-01

    Amyloid β (Aβ) is the major component of senile plaques (SP) in the brains of Alzheimer's disease (AD) patients, and serves as an inflammatory stimulus for microglia. Trans-caryophyllene (TC), a major component in the essential oils derived from various species of medicinal plants, has displayed its neuro-protective effects in previous studies. However, whether TC has a protective role in AD remains unknown. In this study, the effects of TC on Aβ 1-42 -induced neuro-inflammation were investigated. We found that TC reduced the release of LDH in BV-2 microglial cells treated with Aβ 1-42 . In addition, pretreatment of BV2 microglia with TC at concentrations of 10, 25, and 50μM prior to Aβ stimulation led to significant inhibition of nitric oxide (NO) and prostaglandin E2 (PGE2) production, expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), and secretion of pro-inflammatory cytokines. Notably, our results indicate that TC remarkably attenuated Aβ 1-42 -activated overexpression of toll-like receptor 4 (TLR4). We further demonstrated that TC markedly reversed Aβ 1-42 -induced phosphorylation and degradation of IκBα, nuclear translocation of p65, and NF-κB transcriptional activity. These findings suggest that TC may have therapeutic potential for the treatment of AD. Copyright © 2017. Published by Elsevier B.V.

  13. Identification of a novel dehydroergosterol enhancing microglial anti-inflammatory activity in a dairy product fermented with Penicillium candidum.

    Directory of Open Access Journals (Sweden)

    Yasuhisa Ano

    Full Text Available Despite the ever-increasing number of dementia patients worldwide, fundamental therapeutic approaches to treat this disease remain to be established. Preventive approaches such as diet, exercise and learning attract attention. Several epidemiological studies suggest that ingestion of fermented dairy products prevents cognitive decline in the elderly. These reports indicate that specific ingredients in the fermented dairy products elicit an anti-inflammatory or anti-oxidative activity that facilitates neuroprotection. The responsible components remain to be investigated. A number of studies have shown that inflammation caused by microglia is closely related to exaggeration of the pathology and cognitive decline seen in the elderly. Many researchers have proposed that controlling microglial activities could be effective in preventing and possibly curing dementia. In the present study, to elucidate specific compounds that regulate microglial activity from dairy products, repeated purification by HPLC, combined with evaluation using primary microglia, facilitated the identification of dehydroergosterol (DHE as a novel component of the extract that enhances microglial anti-inflammatory activity. DHE contains three conjugated double bonds in a steroid ring system and is an analogue of ergosterol. Despite their related chemical structures, the anti-inflammatory activity of DHE is markedly stronger than that of ergosterol. P. candidum for camembert cheese produces DHE, but P. Roqueforti for blue cheese and Aspergillus do not. DHE also induces CD11b-positive microglia cells into CD206-positive M2 type microglia. Neurotoxicity and neuronal cell death induced by excessively activated microglia is suppressed by treatment with DHE. Thus, this is the first report to demonstrate that DHE, identified as a responsible compound in dairy products, can induce microglia into a preferable phenotype for our brain environment and can be safely introduced into the body

  14. Identification of a novel dehydroergosterol enhancing microglial anti-inflammatory activity in a dairy product fermented with Penicillium candidum.

    Science.gov (United States)

    Ano, Yasuhisa; Kutsukake, Toshiko; Hoshi, Ayaka; Yoshida, Aruto; Nakayama, Hiroyuki

    2015-01-01

    Despite the ever-increasing number of dementia patients worldwide, fundamental therapeutic approaches to treat this disease remain to be established. Preventive approaches such as diet, exercise and learning attract attention. Several epidemiological studies suggest that ingestion of fermented dairy products prevents cognitive decline in the elderly. These reports indicate that specific ingredients in the fermented dairy products elicit an anti-inflammatory or anti-oxidative activity that facilitates neuroprotection. The responsible components remain to be investigated. A number of studies have shown that inflammation caused by microglia is closely related to exaggeration of the pathology and cognitive decline seen in the elderly. Many researchers have proposed that controlling microglial activities could be effective in preventing and possibly curing dementia. In the present study, to elucidate specific compounds that regulate microglial activity from dairy products, repeated purification by HPLC, combined with evaluation using primary microglia, facilitated the identification of dehydroergosterol (DHE) as a novel component of the extract that enhances microglial anti-inflammatory activity. DHE contains three conjugated double bonds in a steroid ring system and is an analogue of ergosterol. Despite their related chemical structures, the anti-inflammatory activity of DHE is markedly stronger than that of ergosterol. P. candidum for camembert cheese produces DHE, but P. Roqueforti for blue cheese and Aspergillus do not. DHE also induces CD11b-positive microglia cells into CD206-positive M2 type microglia. Neurotoxicity and neuronal cell death induced by excessively activated microglia is suppressed by treatment with DHE. Thus, this is the first report to demonstrate that DHE, identified as a responsible compound in dairy products, can induce microglia into a preferable phenotype for our brain environment and can be safely introduced into the body by consumption of

  15. Microglial activation induced by brain trauma is suppressed by post-injury treatment with a PARP inhibitor

    Directory of Open Access Journals (Sweden)

    d'Avila Joana C

    2012-02-01

    Full Text Available Abstract Background Traumatic brain injury (TBI induces activation of microglia. Activated microglia can in turn increase secondary injury and impair recovery. This innate immune response requires hours to days to become fully manifest, thus providing a clinically relevant window of opportunity for therapeutic intervention. Microglial activation is regulated in part by poly(ADP-ribose polymerase-1 (PARP-1. Inhibition of PARP-1 activity suppresses NF-kB-dependent gene transcription and thereby blocks several aspects of microglial activation. Here we evaluated the efficacy of a PARP inhibitor, INO-1001, in suppressing microglial activation after cortical impact in the rat. Methods Rats were subjected to controlled cortical impact and subsequently treated with 10 mg/kg of INO-1001 (or vehicle alone beginning 20 - 24 hours after the TBI. Brains were harvested at several time points for histological evaluation of inflammation and neuronal survival, using markers for microglial activation (morphology and CD11b expression, astrocyte activation (GFAP, and neuronal survival (NeuN. Rats were also evaluated at 8 weeks after TBI using measures of forelimb dexterity: the sticky tape test, cylinder test, and vermicelli test. Results Peak microglial and astrocyte activation was observed 5 to 7 days after this injury. INO-1001 significantly reduced microglial activation in the peri-lesion cortex and ipsilateral hippocampus. No rebound inflammation was observed in rats that were treated with INO-1001 or vehicle for 12 days followed by 4 days without drug. The reduced inflammation was associated with increased neuronal survival in the peri-lesion cortex and improved performance on tests of forelimb dexterity conducted 8 weeks after TBI. Conclusions Treatment with a PARP inhibitor for 12 days after TBI, with the first dose given as long as 20 hours after injury, can reduce inflammation and improve histological and functional outcomes.

  16. Mir143-BBC3 cascade reduces microglial survival via interplay between apoptosis and autophagy: Implications for methamphetamine-mediated neurotoxicity

    Science.gov (United States)

    Zhang, Yuan; Shen, Kai; Bai, Ying; Lv, Xuan; Huang, Rongrong; Zhang, Wei; Chao, Jie; Nguyen, Lan K.; Hua, Jun; Gan, Guangming; Hu, Gang; Yao, Honghong

    2016-01-01

    ABSTRACT BBC3 (BCL2 binding component 3) is a known apoptosis inducer; however, its role in microglial survival remains poorly understood. In addition to the classical transcription factor TRP53, Mir143 is involved in BBC3 expression at the post-transcriptional level. Here, we identify unique roles of Mir143-BBC3 in mediating microglial survival via the regulation of the interplay between apoptosis and autophagy. Autophagy inhibition accelerated methamphetamine-induced apoptosis, whereas autophagy induction attenuated the decrease in microglial survival. Moreover, anti-Mir143-dependent BBC3 upregulation reversed the methamphetamine-induced decrease in microglial survival via the regulation of apoptosis and autophagy. The in vivo relevance of these findings was confirmed in mouse models, which demonstrated that the microinjection of anti-Mir143 into the hippocampus ameliorated the methamphetamine-induced decrease in microglia as well as that observed in heterozygous Mir143+/− mice. These findings provide new insight regarding the specific contributions of Mir143-BBC3 to microglial survival in the context of drug abuse. PMID:27464000

  17. Inhibition of microglial activation protects hippocampal neurogenesis and improves cognitive deficits in a transgenic mouse model for Alzheimer's disease.

    Science.gov (United States)

    Biscaro, Barbara; Lindvall, Olle; Tesco, Giuseppina; Ekdahl, Christine T; Nitsch, Roger M

    2012-01-01

    Activated microglia with macrophage-like functions invade and surround β-amyloid (Aβ) plaques in Alzheimer's disease (AD), possibly contributing to the turnover of Aβ, but they can also secrete proinflammatory factors that may be involved in the pathogenesis of AD. Microglia are known to modulate adult hippocampal neurogenesis. To determine the role of microglia on neurogenesis in brains with Aβ pathology, we inhibited microglial activation with the tetracycline derivative minocycline in doubly transgenic mice expressing mutant human amyloid precursor protein (APP) and mutant human presenilin-1 (PS1). Minocycline increased the survival of new dentate granule cells in APP/PS1 mice indicated by more BrdU+/NeuN+ cells as compared to vehicle-treated transgenic littermates, accompanied by improved behavioral performance in a hippocampus-dependent learning task. Both brain levels of Aβ and Aβ-related morphological deficits in the new neurons labeled with GFP-expressing retrovirus were unaffected in minocycline-treated mice. These results suggest a role for microglia in Aβ-related functional deficits and in suppressing the survival of new neurons, and show that modulation of microglial function with minocycline can protect hippocampal neurogenesis in the presence of Aβ pathology. Copyright © 2012 S. Karger AG, Basel.

  18. Essential roles of mitochondrial depolarization in neuron loss through microglial activation and attraction toward neurons.

    Science.gov (United States)

    Nam, Min-Kyung; Shin, Hyun-Ah; Han, Ji-Hye; Park, Dae-Wook; Rhim, Hyangshuk

    2013-04-10

    As life spans increased, neurodegenerative disorders that affect aging populations have also increased. Progressive neuronal loss in specific brain regions is the most common cause of neurodegenerative disease; however, key determinants mediating neuron loss are not fully understood. Using a model of mitochondrial membrane potential (ΔΨm) loss, we found only 25% cell loss in SH-SY5Y (SH) neuronal mono-cultures, but interestingly, 85% neuronal loss occurred when neurons were co-cultured with BV2 microglia. SH neurons overexpressing uncoupling protein 2 exhibited an increase in neuron-microglia interactions, which represent an early step in microglial phagocytosis of neurons. This result indicates that ΔΨm loss in SH neurons is an important contributor to recruitment of BV2 microglia. Notably, we show that ΔΨm loss in BV2 microglia plays a crucial role in microglial activation and phagocytosis of damaged SH neurons. Thus, our study demonstrates that ΔΨm loss in both neurons and microglia is a critical determinant of neuron loss. These findings also offer new insights into neuroimmunological and bioenergetical aspects of neurodegenerative disease. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Expression of Eag1 K+ channel and ErbBs in human pituitary adenomas: cytoskeleton arrangement patterns in cultured cells.

    Science.gov (United States)

    del Pliego, Margarita González; Aguirre-Benítez, Elsa; Paisano-Cerón, Karina; Valdovinos-Ramírez, Irene; Rangel-Morales, Carlos; Rodríguez-Mata, Verónica; Solano-Agama, Carmen; Martín-Tapia, Dolores; de la Vega, María Teresa; Saldoval-Balanzario, Miguel; Camacho, Javier; Mendoza-Garrido, María Eugenia

    2013-01-01

    Pituitary adenomas can invade surrounded tissue, but the mechanism remains elusive. Ether à go-go-1 (Eag1) potassium channel and epidermal growth factor receptors (ErbB1 and ErbB2) have been associated to invasive phenotypes or poor prognosis in cancer patients. However, cells arrange their cytoskeleton in order to acquire a successful migration pattern. We have studied ErbBs and Eag1 expression, and cytoskeleton arrangements in 11 human pituitary adenomas. Eag1, ErbB1 and ErbB2 expression were studied by immunochemistry in tissue and cultured cells. The cytoskeleton arrangement was analyzed in cultured cells by immunofluorescence. Normal pituitary tissue showed ErbB2 expression and Eag1 only in few cells. However, Eag1 and ErbB2 were expressed in all the tumors analyzed. ErbB1 expression was observed variable and did not show specificity for a tumor characteristic. Cultured cells from micro- and macro-adenomas clinically functional organize their cytoskeleton suggesting a mesenchymal pattern, and a round leucocyte/amoeboid pattern from invasive clinically silent adenoma. Pituitary tumors over-express EGF receptors and the ErbB2 repeated expression suggests is a characteristic of adenomas. Eag 1 was express, in different extent, and could be a therapeutic target. The cytoskeleton arrangements observed suggest that pituitary tumor cells acquire different patterns: mesenchymal, and leucocyte/amoeboid, the last observed in the invasive adenomas. Amoeboid migration pattern has been associated with high invasion capacity.

  20. Experimental autoimmune prostatitis induces microglial activation in the spinal cord.

    Science.gov (United States)

    Wong, Larry; Done, Joseph D; Schaeffer, Anthony J; Thumbikat, Praveen

    2015-01-01

    The pathogenesis of chronic prostatitis/chronic pelvic pain syndrome is unknown and factors including the host's immune response and the nervous system have been attributed to the development of CP/CPPS. We previously demonstrated that mast cells and chemokines such as CCL2 and CCL3 play an important role in mediating prostatitis. Here, we examined the role of neuroinflammation and microglia in the CNS in the development of chronic pelvic pain. Experimental autoimmune prostatitis (EAP) was induced using a subcutaneous injection of rat prostate antigen. Sacral spinal cord tissue (segments S14-S5) was isolated and utilized for immunofluorescence or QRT-PCR analysis. Tactile allodynia was measured at baseline and at various points during EAP using Von Frey fibers as a function for pelvic pain. EAP mice were treated with minocycline after 30 days of prostatitis to test the efficacy of microglial inhibition on pelvic pain. Prostatitis induced the expansion and activation of microglia and the development of inflammation in the spinal cord as determined by increased expression levels of CCL3, IL-1β, Iba1, and ERK1/2 phosphorylation. Microglial activation in mice with prostatitis resulted in increased expression of P2X4R and elevated levels of BDNF, two molecular markers associated with chronic pain. Pharmacological inhibition of microglia alleviated pain in mice with prostatitis and resulted in decreased expression of IL-1β, P2X4R, and BDNF. Our data show that prostatitis leads to inflammation in the spinal cord and the activation and expansion of microglia, mechanisms that may contribute to the development and maintenance of chronic pelvic pain. © 2014 Wiley Periodicals, Inc.

  1. Targeting Microglial KATP Channels to Treat Neurodegenerative Diseases: A Mitochondrial Issue

    Directory of Open Access Journals (Sweden)

    Manuel J. Rodríguez

    2013-01-01

    Full Text Available Neurodegeneration is a complex process involving different cell types and neurotransmitters. A common characteristic of neurodegenerative disorders is the occurrence of a neuroinflammatory reaction in which cellular processes involving glial cells, mainly microglia and astrocytes, are activated in response to neuronal death. Microglia do not constitute a unique cell population but rather present a range of phenotypes closely related to the evolution of neurodegeneration. In a dynamic equilibrium with the lesion microenvironment, microglia phenotypes cover from a proinflammatory activation state to a neurotrophic one directly involved in cell repair and extracellular matrix remodeling. At each moment, the microglial phenotype is likely to depend on the diversity of signals from the environment and of its response capacity. As a consequence, microglia present a high energy demand, for which the mitochondria activity determines the microglia participation in the neurodegenerative process. As such, modulation of microglia activity by controlling microglia mitochondrial activity constitutes an innovative approach to interfere in the neurodegenerative process. In this review, we discuss the mitochondrial KATP channel as a new target to control microglia activity, avoid its toxic phenotype, and facilitate a positive disease outcome.

  2. Increased microglial catalase activity in multiple sclerosis grey matter.

    Science.gov (United States)

    Gray, Elizabeth; Kemp, Kevin; Hares, Kelly; Redondo, Julianna; Rice, Claire; Scolding, Neil; Wilkins, Alastair

    2014-04-22

    Chronic demyelination, on-going inflammation, axonal loss and grey matter neuronal injury are likely pathological processes that contribute to disease progression in multiple sclerosis (MS). Although the precise contribution of each process and their aetiological substrates is not fully known, recent evidence has implicated oxidative damage as a major cause of tissue injury in MS. The degree of tissue injury caused by oxidative molecules, such as reactive oxygen species (ROS), is balanced by endogenous anti-oxidant enzymes which detoxify ROS. Understanding endogenous mechanisms which protect the brain against oxidative injury in MS is important, since enhancing anti-oxidant responses is a major therapeutic strategy for preventing irreversible tissue injury in the disease. Our aims were to determine expression and activity levels of the hydrogen peroxide-reducing enzyme catalase in MS grey matter (GM). In MS GM, a catalase enzyme activity was elevated compared to control GM. We measured catalase protein expression by immune dot-blotting and catalase mRNA by a real-time polymerase chain reaction (RT-PCR). Protein analysis studies showed a strong positive correlation between catalase and microglial marker IBA-1 in MS GM. In addition, calibration of catalase mRNA level with reference to the microglial-specific transcript AIF-1 revealed an increase in this transcript in MS. This was reflected by the extent of HLA-DR immunolabeling in MS GM which was significantly elevated compared to control GM. Collectively, these observations provide evidence that microglial catalase activity is elevated in MS grey matter and may be an important endogenous anti-oxidant defence mechanism in MS. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Characteristic microglial features in patients with hereditary diffuse leukoencephalopathy with spheroids.

    Science.gov (United States)

    Tada, Mari; Konno, Takuya; Tada, Masayoshi; Tezuka, Toshiyuki; Miura, Takeshi; Mezaki, Naomi; Okazaki, Ken-Ichi; Arakawa, Musashi; Itoh, Kyoko; Yamamoto, Toru; Yokoo, Hideaki; Yoshikura, Nobuaki; Ishihara, Kenji; Horie, Masao; Takebayashi, Hirohide; Toyoshima, Yasuko; Naito, Makoto; Onodera, Osamu; Nishizawa, Masatoyo; Takahashi, Hitoshi; Ikeuchi, Takeshi; Kakita, Akiyoshi

    2016-10-01

    To clarify the histopathological alterations of microglia in the brains of patients with hereditary diffuse leukoencephalopathy with spheroids (HDLS) caused by mutations of the gene encoding the colony stimulating factor-1 receptor (CSF-1R). We examined 5 autopsied brains and 1 biopsy specimen from a total of 6 patients with CSF-1R mutations. Detailed immunohistochemical, biochemical, and ultrastructural features of microglia were examined, and quantitative analyses were performed. In layers 3 to 4 of the frontal cortex in HDLS brains, microglia showed relatively uniform and delicate morphology, with thin and winding processes accompanying knotlike structures, and significantly smaller areas of Iba1 immunoreactivity and lower numbers of Iba1-positive cells were evident in comparison with control brains. On the other hand, in layers 5 to 6 and the underlying white matter, microglia were distributed unevenly; that is, in some areas they had accumulated densely, whereas in others they were scattered. Immunoblot analyses of microglia-associated proteins, including CD11b and DAP12, revealed that HDLS brains had significantly lower amounts of these proteins than diseased controls, although Ki-67-positive proliferative microglia were not reduced. Ultrastructurally, the microglial cytoplasm and processes in HDLS showed vesiculation of the rough endoplasmic reticulum and disaggregated polyribosomes, indicating depression of protein synthesis. On the other hand, macrophages were immunonegative for GLUT-5 or P2ry12, indicating that they were derived from bone marrow. The pathogenesis of HDLS seems to be associated with microglial vulnerability and morphological alterations. Ann Neurol 2016;80:554-565. © 2016 American Neurological Association.

  4. Microglial activation and neuroinflammation in Alzheimer's disease: a critical examination of recent history

    Directory of Open Access Journals (Sweden)

    Wolfgang J Streit

    2010-06-01

    Full Text Available The neurofibrillary degeneration that occurs in Alzheimer’s disease (AD is thought to be the result of a chronic and damaging neuroinflammatory response mediated by neurotoxic substances produced by activated microglial cells. This neuroinflammation hypothesis of AD pathogenesis has led to numerous clinical trials with anti-inflammatory drugs, none of which have shown clear benefits for slowing or preventing disease onset and progression. In this paper, I make the point that AD is not an inflammatory condition, and reconstruct the sequence of events during the 1980s and 1990s that I believe led to the development of this faulty theory.

  5. Relationships between selective neuronal loss and microglial activation after ischaemic stroke in man.

    Science.gov (United States)

    Morris, Rhiannon S; Simon Jones, P; Alawneh, Josef A; Hong, Young T; Fryer, Tim D; Aigbirhio, Franklin I; Warburton, Elizabeth A; Baron, Jean-Claude

    2018-05-09

    Modern ischaemic stroke management involves intravenous thrombolysis followed by mechanical thrombectomy, which allows markedly higher rates of recanalization and penumbral salvage than thrombolysis alone. However, <50% of treated patients eventually enjoy independent life. It is therefore important to identify complementary therapeutic targets. In rodent models, the salvaged penumbra is consistently affected by selective neuronal loss, which may hinder recovery by interfering with plastic processes, as well as by microglial activation, which may exacerbate neuronal death. However, whether the salvaged penumbra in man is similarly affected is still unclear. Here we determined whether these two processes affect the non-infarcted penumbra in man and, if so, whether they are inter-related. We prospectively recruited patients with (i) acute middle-cerebral artery stroke; (ii) penumbra present on CT perfusion obtained <4.5 h of stroke onset; and (iii) early neurological recovery as a marker of penumbral salvage. PET with 11C-flumazenil and 11C-PK11195, as well as MRI to map the final infarct, were obtained at predefined follow-up times. The presence of selective neuronal loss and microglial activation was determined voxel-wise within the MRI normal-appearing ipsilateral non-infarcted zone and surviving penumbra masks, and their inter-relationship was assessed both across and within patients. Dilated infarct contours were consistently excluded to control for partial volume effects. Across the 16 recruited patients, there was reduced 11C-flumazenil and increased 11C-PK11195 binding in the whole ipsilateral non-infarcted zone (P = 0.04 and 0.02, respectively). Within the non-infarcted penumbra, 11C-flumazenil was also reduced (P = 0.001), but without clear increase in 11C-PK11195 (P = 0.18). There was no significant correlation between 11C-flumazenil and 11C-PK11195 in either compartment. This mechanistic study provides direct evidence for the presence of both neuronal

  6. Role of fractalkine/CX3CR1 interaction in light-induced photoreceptor degeneration through regulating retinal microglial activation and migration.

    Directory of Open Access Journals (Sweden)

    Meng Zhang

    Full Text Available BACKGROUND: Excessive exposure to light enhances the progression and severity of some human retinal degenerative diseases. While retinal microglia are likely to be important in neuron damage associated with these diseases, the relationship between photoreceptor damage and microglial activation remains poorly understood. Some recent studies have indicated that the chemokine fractalkine is involved in the pathogenesis of many neurodegenerative diseases. The present study was performed to investigate the cross-talk between injured photoreceptors and activated retinal microglia, focusing on the role of fractalkine and its receptor CX3CR1 in light-induced photoreceptor degeneration. METHODOLOGY/PRINCIPAL FINDINGS: Both in vivo and in vitro experiments were involved in the research. In vivo, Sprague-Dawley rats were exposed to blue light for 24 hours. In vitro, the co-culture of primary retinal microglia and a photoreceptor cell line (661W cell was exposed to blue light for five hours. Some cultures were pretreated by the addition of anti-CX3CR1 neutralizing antibody or recombinant fractalkine. Expression of fractalkine/CX3CR1 and inflammatory cytokines was detected by immunofluorescence, real-time PCR, Western immunoblot analysis, and ELISA assay. TUNEL method was used to detect cell apoptosis. In addition, chemotaxis assay was performed to evaluate the impact of soluble fractalkine on microglial migration. Our results showed that the expression of fractalkine that was significantly upregulated after exposure to light, located mainly at the photoreceptors. The extent of photoreceptor degeneration and microglial migration paralleled the increased level of fractalkine/CX3CR1. Compared with the control, the expression of inflammatory cytokines was significantly downregulated in the anti-CX3CR1 neutralizing antibody-treated group, and the number of photoreceptors was also well preserved. The addition of recombinant full-length fractalkine or soluble

  7. Cell-substrate impedance fluctuations of single amoeboid cells encode cell-shape and adhesion dynamics.

    Science.gov (United States)

    Leonhardt, Helmar; Gerhardt, Matthias; Höppner, Nadine; Krüger, Kirsten; Tarantola, Marco; Beta, Carsten

    2016-01-01

    We show systematic electrical impedance measurements of single motile cells on microelectrodes. Wild-type cells and mutant strains were studied that differ in their cell-substrate adhesion strength. We recorded the projected cell area by time-lapse microscopy and observed irregular oscillations of the cell shape. These oscillations were correlated with long-term variations in the impedance signal. Superposed to these long-term trends, we observed fluctuations in the impedance signal. Their magnitude clearly correlated with the adhesion strength, suggesting that strongly adherent cells display more dynamic cell-substrate interactions.

  8. Cell-substrate impedance fluctuations of single amoeboid cells encode cell-shape and adhesion dynamics

    Science.gov (United States)

    Leonhardt, Helmar; Gerhardt, Matthias; Höppner, Nadine; Krüger, Kirsten; Tarantola, Marco; Beta, Carsten

    2016-01-01

    We show systematic electrical impedance measurements of single motile cells on microelectrodes. Wild-type cells and mutant strains were studied that differ in their cell-substrate adhesion strength. We recorded the projected cell area by time-lapse microscopy and observed irregular oscillations of the cell shape. These oscillations were correlated with long-term variations in the impedance signal. Superposed to these long-term trends, we observed fluctuations in the impedance signal. Their magnitude clearly correlated with the adhesion strength, suggesting that strongly adherent cells display more dynamic cell-substrate interactions.

  9. Prenatal Immune Challenge in Mice Leads to Partly Sex-Dependent Behavioral, Microglial, and Molecular Abnormalities Associated with Schizophrenia

    Directory of Open Access Journals (Sweden)

    Chin W. Hui

    2018-02-01

    Full Text Available Epidemiological studies revealed that environmental factors comprising prenatal infection are strongly linked to risk for later development of neuropsychiatric disorders such as schizophrenia. Considering strong sex differences in schizophrenia and its increased prevalence in males, we designed a methodological approach to investigate possible sex differences in pathophysiological mechanisms. Prenatal immune challenge was modeled by systemic administration of the viral mimic polyinosinic-polycytidylic acid (Poly I:C to C57BL/6 mice at embryonic day 9.5. The consequences on behavior, gene expression, and microglia—brain immune cells that are critical for normal development—were characterized in male vs. female offspring at adulthood. The cerebral cortex, hippocampus, and cerebellum, regions where structural and functional alterations were mainly described in schizophrenia patients, were selected for cellular and molecular analyses. Confocal and electron microscopy revealed most pronounced differences in microglial distribution, arborization, cellular stress, and synaptic interactions in the hippocampus of male vs. female offspring exposed to Poly I:C. Sex differences in microglia were also measured under both steady-state and Poly I:C conditions. These microglial alterations were accompanied by behavioral impairment, affecting for instance sensorimotor gating, in males. Consistent with these results, increased expression of genes related to inflammation was measured in cerebral cortex and hippocampus of males challenged with Poly I:C. Overall, these findings suggest that schizophrenia's higher incidence in males might be associated, among other mechanisms, with an increased microglial reactivity to prenatal immune challenges, hence determining disease outcomes into adulthood.

  10. Cytomegalovirus Infection of the Rat Developing Brain In Utero Prominently Targets Immune Cells and Promotes Early Microglial Activation.

    Directory of Open Access Journals (Sweden)

    Robin Cloarec

    Full Text Available Congenital cytomegalovirus infections are a leading cause of neurodevelopmental disorders in human and represent a major health care and socio-economical burden. In contrast with this medical importance, the pathophysiological events remain poorly known. Murine models of brain cytomegalovirus infection, mostly neonatal, have brought recent insights into the possible pathogenesis, with convergent evidence for the alteration and possible involvement of brain immune cells.In order to confirm and expand those findings, particularly concerning the early developmental stages following infection of the fetal brain, we have created a model of in utero cytomegalovirus infection in the developing rat brain. Rat cytomegalovirus was injected intraventricularly at embryonic day 15 (E15 and the brains analyzed at various stages until the first postnatal day, using a combination of gene expression analysis, immunohistochemistry and multicolor flow cytometry experiments.Rat cytomegalovirus infection was increasingly seen in various brain areas including the choroid plexi and the ventricular and subventricular areas and was prominently detected in CD45low/int, CD11b+ microglial cells, in CD45high, CD11b+ cells of the myeloid lineage including macrophages, and in CD45+, CD11b- lymphocytes and non-B non-T cells. In parallel, rat cytomegalovirus infection of the developing rat brain rapidly triggered a cascade of pathophysiological events comprising: chemokines upregulation, including CCL2-4, 7 and 12; infiltration by peripheral cells including B-cells and monocytes at E17 and P1, and T-cells at P1; and microglia activation at E17 and P1.In line with previous findings in neonatal murine models and in human specimen, our study further suggests that neuroimmune alterations might play critical roles in the early stages following cytomegalovirus infection of the brain in utero. Further studies are now needed to determine which role, whether favorable or detrimental

  11. Severe depression is associated with increased microglial quinolinic acid in subregions of the anterior cingulate gyrus: Evidence for an immune-modulated glutamatergic neurotransmission?

    Directory of Open Access Journals (Sweden)

    Mawrin Christian

    2011-08-01

    Full Text Available Abstract Background Immune dysfunction, including monocytosis and increased blood levels of interleukin-1, interleukin-6 and tumour necrosis factor α has been observed during acute episodes of major depression. These peripheral immune processes may be accompanied by microglial activation in subregions of the anterior cingulate cortex where depression-associated alterations of glutamatergic neurotransmission have been described. Methods Microglial immunoreactivity of the N-methyl-D-aspartate (NMDA glutamate receptor agonist quinolinic acid (QUIN in the subgenual anterior cingulate cortex (sACC, anterior midcingulate cortex (aMCC and pregenual anterior cingulate cortex (pACC of 12 acutely depressed suicidal patients (major depressive disorder/MDD, n = 7; bipolar disorder/BD, n = 5 was analyzed using immunohistochemistry and compared with its expression in 10 healthy control subjects. Results Depressed patients had a significantly increased density of QUIN-positive cells in the sACC (P = 0.003 and the aMCC (P = 0.015 compared to controls. In contrast, counts of QUIN-positive cells in the pACC did not differ between the groups (P = 0.558. Post-hoc tests showed that significant findings were attributed to MDD and were absent in BD. Conclusions These results add a novel link to the immune hypothesis of depression by providing evidence for an upregulation of microglial QUIN in brain regions known to be responsive to infusion of NMDA antagonists such as ketamine. Further work in this area could lead to a greater understanding of the pathophysiology of depressive disorders and pave the way for novel NMDA receptor therapies or immune-modulating strategies.

  12. Variability and Order in Cytoskeletal Dynamics of Motile Amoeboid Cells

    Science.gov (United States)

    Hsu, Hsin-Fang; Bodenschatz, Eberhard; Westendorf, Christian; Gholami, Azam; Pumir, Alain; Tarantola, Marco; Beta, Carsten

    2017-10-01

    The chemotactic motion of eukaryotic cells such as leukocytes or metastatic cancer cells relies on membrane protrusions driven by the polymerization and depolymerization of actin. Here we show that the response of the actin system to a receptor stimulus is subject to a threshold value that varies strongly from cell to cell. Above the threshold, we observe pronounced cell-to-cell variability in the response amplitude. The polymerization time, however, is almost constant over the entire range of response amplitudes, while the depolymerization time increases with increasing amplitude. We show that cell-to-cell variability in the response amplitude correlates with the amount of Arp2 /3 , a protein that enhances actin polymerization. A time-delayed feedback model for the cortical actin concentration is consistent with all our observations and confirms the role of Arp2 /3 in the observed cell-to-cell variability. Taken together, our observations highlight robust regulation of the actin response that enables a reliable timing of cell movement.

  13. Delayed xenon post-conditioning mitigates spinal cord ischemia/reperfusion injury in rabbits by regulating microglial activation and inflammatory factors.

    Science.gov (United States)

    Yang, Yan-Wei; Wang, Yun-Lu; Lu, Jia-Kai; Tian, Lei; Jin, Mu; Cheng, Wei-Ping

    2018-03-01

    The neuroprotective effect against spinal cord ischemia/reperfusion injury in rats exerted by delayed xenon post-conditioning is stronger than that produced by immediate xenon post-conditioning. However, the mechanisms underlying this process remain unclear. Activated microglia are the main inflammatory cell type in the nervous system. The release of pro-inflammatory factors following microglial activation can lead to spinal cord damage, and inhibition of microglial activation can relieve spinal cord ischemia/reperfusion injury. To investigate how xenon regulates microglial activation and the release of inflammatory factors, a rabbit model of spinal cord ischemia/reperfusion injury was induced by balloon occlusion of the infrarenal aorta. After establishment of the model, two interventions were given: (1) immediate xenon post-conditioning-after reperfusion, inhalation of 50% xenon for 1 hour, 50% N 2 /50%O 2 for 2 hours; (2) delayed xenon post-conditioning-after reperfusion, inhalation of 50% N 2 /50%O 2 for 2 hours, 50% xenon for 1 hour. At 4, 8, 24, 48 and 72 hours after reperfusion, hindlimb locomotor function was scored using the Jacobs locomotor scale. At 72 hours after reperfusion, interleukin 6 and interleukin 10 levels in the spinal cord of each group were measured using western blot assays. Iba1 levels were determined using immunohistochemistry and a western blot assay. The number of normal neurons at the injury site was quantified using hematoxylin-eosin staining. At 72 hours after reperfusion, delayed xenon post-conditioning remarkably enhanced hindlimb motor function, increased the number of normal neurons at the injury site, decreased Iba1 levels, and inhibited interleukin-6 and interleukin-10 levels in the spinal cord. Immediate xenon post-conditioning did not noticeably affect the above-mentioned indexes. These findings indicate that delayed xenon post-conditioning after spinal cord injury improves the recovery of neurological function by reducing

  14. Podosomes, But Not the Maturation Status, Determine the Protease-Dependent 3D Migration in Human Dendritic Cells.

    Science.gov (United States)

    Cougoule, Céline; Lastrucci, Claire; Guiet, Romain; Mascarau, Rémi; Meunier, Etienne; Lugo-Villarino, Geanncarlo; Neyrolles, Olivier; Poincloux, Renaud; Maridonneau-Parini, Isabelle

    2018-01-01

    Dendritic cells (DC) are professional Antigen-Presenting Cells scattered throughout antigen-exposed tissues and draining lymph nodes, and survey the body for pathogens. Their ability to migrate through tissues, a 3D environment, is essential for an effective immune response. Upon infection, recognition of Pathogen-Associated Molecular Patterns (PAMP) by Toll-like receptors (TLR) triggers DC maturation. Mature DC (mDC) essentially use the protease-independent, ROCK-dependent amoeboid mode in vivo , or in collagen matrices in vitro . However, the mechanisms of 3D migration used by human immature DC (iDC) are still poorly characterized. Here, we reveal that human monocyte-derived DC are able to use two migration modes in 3D. In porous matrices of fibrillar collagen I, iDC adopted the amoeboid migration mode. In dense matrices of gelled collagen I or Matrigel, iDC used the protease-dependent, ROCK-independent mesenchymal migration mode. Upon TLR4 activation by LPS, mDC-LPS lose the capacity to form podosomes and degrade the matrix along with impaired mesenchymal migration. TLR2 activation by Pam 3 CSK 4 resulted in DC maturation, podosome maintenance, and efficient mesenchymal migration. Under all these conditions, when DC used the mesenchymal mode in dense matrices, they formed 3D podosomes at the tip of cell protrusions. Using PGE 2 , known to disrupt podosomes in DC, we observed that the cells remained in an immature status and the mesenchymal migration mode was abolished. We also observed that, while CCL5 (attractant of iDC) enhanced both amoeboid and mesenchymal migration of iDC, CCL19 and CCL21 (attractants of mDC) only enhanced mDC-LPS amoeboid migration without triggering mesenchymal migration. Finally, we examined the migration of iDC in tumor cell spheroids, a tissue-like 3D environment. We observed that iDC infiltrated spheroids of tumor cells using both migration modes. Altogether, these results demonstrate that human DC adopt the mesenchymal mode to

  15. Microglial Lectins in Health and Neurological Diseases

    Directory of Open Access Journals (Sweden)

    Jian Jing Siew

    2018-05-01

    Full Text Available Microglia are the innate sentinels of the central nervous system (CNS and are responsible for the homeostasis and immune defense of the CNS. Under the influence of the local environment and cell-cell interaction, microglia exhibit a multidimensional and context-dependent phenotypes that can be cytotoxic and neuroprotective. Recent studies suggest that microglia express multitudinous types of lectins, including galectins, Siglecs, mannose-binding lectins (MBLs and other glycan binding proteins. Because most studies that examine lectins focus on the peripheral system, the functions of lectins have not been critically investigated in the CNS. In addition, the types of brain cells that contribute to the altered levels of lectins present in diseases are often unclear. In this review, we will discuss how galectins, Siglecs, selectins and MBLs contribute to the dynamic functions of microglia. The interacting ligands of these lectins are complex glycoconjugates, which consist of glycoproteins and glycolipids that are expressed on microglia or surrounding cells. The current understanding of the heterogeneity and functions of glycans in the brain is limited. Galectins are a group of pleotropic proteins that recognize both β-galactoside-containing glycans and non- β-galactoside-containing proteins. The function and regulation of galectins have been implicated in immunomodulation, neuroinflammation, apoptosis, phagocytosis and oxidative bursts. Most Siglecs are expressed at a low level on the plasma membrane and bind to sialic acid residues for immunosurveillance and cell-cell communication. Siglecs are classified based on their inhibitory and activatory downstream signaling properties. Inhibitory Siglecs negatively regulate microglia activation upon recognizing the intact sialic acid patterns and vice versa. MBLs are expressed upon infection in cytoplasm and can be secreted in order to recognize molecules containing terminal mannose as an innate immune

  16. Chronic apocynin treatment attenuates beta amyloid plaque size and microglial number in hAPP(751(SL mice.

    Directory of Open Access Journals (Sweden)

    Melinda E Lull

    Full Text Available NADPH oxidase is implicated in neurotoxic microglial activation and the progressive nature of Alzheimer's Disease (AD. Here, we test the ability of two NADPH oxidase inhibitors, apocynin and dextromethorphan (DM, to reduce learning deficits and neuropathology in transgenic mice overexpressing human amyloid precursor protein with the Swedish and London mutations (hAPP(751(SL.Four month old hAPP(751(SL mice were treated daily with saline, 15 mg/kg DM, 7.5 mg/kg DM, or 10 mg/kg apocynin by gavage for four months.Only hAPP(751(SL mice treated with apocynin showed reduced plaque size and a reduction in the number of cortical microglia, when compared to the saline treated group. Analysis of whole brain homogenates from all treatments tested (saline, DM, and apocynin demonstrated low levels of TNFα, protein nitration, lipid peroxidation, and NADPH oxidase activation, indicating a low level of neuroinflammation and oxidative stress in hAPP(751(SL mice at 8 months of age that was not significantly affected by any drug treatment. Despite in vitro analyses demonstrating that apocynin and DM ameliorate Aβ-induced extracellular superoxide production and neurotoxicity, both DM and apocynin failed to significantly affect learning and memory tasks or synaptic density in hAPP(751(SL mice. To discern how apocynin was affecting plaque levels (plaque load and microglial number in vivo, in vitro analysis of microglia was performed, revealing no apocynin effects on beta-amyloid (Aβ phagocytosis, microglial proliferation, or microglial survival.Together, this study suggests that while hAPP(751(SL mice show increases in microglial number and plaque load, they fail to exhibit elevated markers of neuroinflammation consistent with AD at 8 months of age, which may be a limitation of this animal model. Despite absence of clear neuroinflammation, apocynin was still able to reduce both plaque size and microglial number, suggesting that apocynin may have additional

  17. Cellular demise and inflammatory microglial activation during beta-amyloid toxicity are governed by Wnt1 and canonical signaling pathways.

    Science.gov (United States)

    Chong, Zhao Zhong; Li, Faqi; Maiese, Kenneth

    2007-06-01

    Initially described as a modulator of embryogenesis for a number of organ systems, Wnt1 has recently been linked to the development of several neurodegenerative disorders, none being of greater significance than Alzheimer's disease. We therefore examined the ability of Wnt1 to oversee vital pathways responsible for cell survival during beta-amyloid (Abeta1-42) exposure. Here we show that Wnt1 is critical for protection in the SH-SY5Y neuronal cell line against genomic DNA degradation, membrane phosphatidylserine (PS) exposure, and microglial activation, since these neuroprotective attributes of Wnt1 are lost during gene silencing of Wnt1 protein expression. Intimately tied to Wnt1 protection is the presence and activation of Akt1. Pharmacological inhibition of the PI 3-K pathway or gene silencing of Akt1 expression can abrogate the protective capacity of Wnt1. Closely aligned with Wnt1 and Akt1 are the integrated canonical pathways of synthase kinase-3beta (GSK-3beta) and beta-catenin. Through Akt1 dependent pathways, Wnt1 phosphorylates GSK-3beta and maintains beta-catenin integrity to insure its translocation from the cytoplasm to the nucleus to block apoptosis. Our work outlines a highly novel role for Wnt1 and its integration with Akt1, GSK-3beta, and beta-catenin to foster neuronal cell survival and repress inflammatory microglial activation that can identify new avenues of therapy against neurodegenerative disorders.

  18. Cdc42-dependent leading edge coordination is essential for interstitial dendritic cell migration

    DEFF Research Database (Denmark)

    Lammermann, Tim; Renkawitz, Jorg; Wu, Xunwei

    2009-01-01

    Mature dendritic cells (DCs) moving from the skin to the lymph node are a prototypic example of rapidly migrating amoeboid leukocytes. Interstitial DC migration is directionally guided by chemokines, but independent of specific adhesive interactions with the tissue as well as pericellular proteol...

  19. Two-dimensional zymography differentiates gelatinase isoforms in stimulated microglial cells and in brain tissues of acute brain injuries.

    Science.gov (United States)

    Chen, Shanyan; Meng, Fanjun; Chen, Zhenzhou; Tomlinson, Brittany N; Wesley, Jennifer M; Sun, Grace Y; Whaley-Connell, Adam T; Sowers, James R; Cui, Jiankun; Gu, Zezong

    2015-01-01

    Excessive activation of gelatinases (MMP-2/-9) is a key cause of detrimental outcomes in neurodegenerative diseases. A single-dimension zymography has been widely used to determine gelatinase expression and activity, but this method is inadequate in resolving complex enzyme isoforms, because gelatinase expression and activity could be modified at transcriptional and posttranslational levels. In this study, we investigated gelatinase isoforms under in vitro and in vivo conditions using two-dimensional (2D) gelatin zymography electrophoresis, a protocol allowing separation of proteins based on isoelectric points (pI) and molecular weights. We observed organomercuric chemical 4-aminophenylmercuric acetate-induced activation of MMP-2 isoforms with variant pI values in the conditioned medium of human fibrosarcoma HT1080 cells. Studies with murine BV-2 microglial cells indicated a series of proform MMP-9 spots separated by variant pI values due to stimulation with lipopolysaccharide (LPS). The MMP-9 pI values were shifted after treatment with alkaline phosphatase, suggesting presence of phosphorylated isoforms due to the proinflammatory stimulation. Similar MMP-9 isoforms with variant pI values in the same molecular weight were also found in mouse brains after ischemic and traumatic brain injuries. In contrast, there was no detectable pI differentiation of MMP-9 in the brains of chronic Zucker obese rats. These results demonstrated effective use of 2D zymography to separate modified MMP isoforms with variant pI values and to detect posttranslational modifications under different pathological conditions.

  20. Pathological histone acetylation in Parkinson's disease: Neuroprotection and inhibition of microglial activation through SIRT 2 inhibition.

    Science.gov (United States)

    Harrison, Ian F; Smith, Andrew D; Dexter, David T

    2018-02-14

    dopaminergic neurons and reduced activation of microglial cells. Taken together, here we demonstrate that histone acetylation is disease-dependently altered in PD, likely due the effects of dopaminergic neurodegeneration and microglial infiltration; yet SIRT 2 remains relatively unaltered with disease. Given the stable nature of SIRT 2 expression with disease and the effects of SIRT 2 inhibitor treatment on degenerating dopaminergic neurons and activated microglia detected in vitro, SIRT 2 inhibitors warrant further investigation as potential therapeutics for the treatment of the PD. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

  1. Rac and Rho GTPases in cancer cell motility control

    Directory of Open Access Journals (Sweden)

    Parri Matteo

    2010-09-01

    Full Text Available Abstract Rho GTPases represent a family of small GTP-binding proteins involved in cell cytoskeleton organization, migration, transcription, and proliferation. A common theme of these processes is a dynamic reorganization of actin cytoskeleton which has now emerged as a major switch control mainly carried out by Rho and Rac GTPase subfamilies, playing an acknowledged role in adaptation of cell motility to the microenvironment. Cells exhibit three distinct modes of migration when invading the 3 D environment. Collective motility leads to movement of cohorts of cells which maintain the adherens junctions and move by photolytic degradation of matrix barriers. Single cell mesenchymal-type movement is characterized by an elongated cellular shape and again requires extracellular proteolysis and integrin engagement. In addition it depends on Rac1-mediated cell polarization and lamellipodia formation. Conversely, in amoeboid movement cells have a rounded morphology, the movement is independent from proteases but requires high Rho GTPase to drive elevated levels of actomyosin contractility. These two modes of cell movement are interconvertible and several moving cells, including tumor cells, show an high degree of plasticity in motility styles shifting ad hoc between mesenchymal or amoeboid movements. This review will focus on the role of Rac and Rho small GTPases in cell motility and in the complex relationship driving the reciprocal control between Rac and Rho granting for the opportunistic motile behaviour of aggressive cancer cells. In addition we analyse the role of these GTPases in cancer progression and metastatic dissemination.

  2. Gestational Exposure to Air Pollution Alters Cortical Volume, Microglial Morphology, and Microglia-Neuron Interactions in a Sex-Specific Manner

    Directory of Open Access Journals (Sweden)

    Jessica L. Bolton

    2017-05-01

    Full Text Available Microglia are the resident immune cells of the brain, important for normal neural development in addition to host defense in response to inflammatory stimuli. Air pollution is one of the most pervasive and harmful environmental toxicants in the modern world, and several large scale epidemiological studies have recently linked prenatal air pollution exposure with an increased risk of neurodevelopmental disorders such as autism spectrum disorder (ASD. Diesel exhaust particles (DEP are a primary toxic component of air pollution, and markedly activate microglia in vitro and in vivo in adult rodents. We have demonstrated that prenatal exposure to DEP in mice, i.e., to the pregnant dams throughout gestation, results in a persistent vulnerability to behavioral deficits in adult offspring, especially in males, which is intriguing given the greater incidence of ASD in males to females (∼4:1. Moreover, there is a striking upregulation of toll-like receptor (TLR 4 gene expression within the brains of the same mice, and this expression is primarily in microglia. Here we explored the impact of gestational exposure to DEP or vehicle on microglial morphology in the developing brains of male and female mice. DEP exposure increased inflammatory cytokine protein and altered the morphology of microglia, consistent with activation or a delay in maturation, only within the embryonic brains of male mice; and these effects were dependent on TLR4. DEP exposure also increased cortical volume at embryonic day (E18, which switched to decreased volume by post-natal day (P30 in males, suggesting an impact on the developing neural stem cell niche. Consistent with this hypothesis, we found increased microglial-neuronal interactions in male offspring that received DEP compared to all other groups. Taken together, these data suggest a mechanism by which prenatal exposure to environmental toxins may affect microglial development and long-term function, and thereby contribute

  3. Layer 5 Pyramidal Neurons’ Dendritic Remodeling and Increased Microglial Density in Primary Motor Cortex in a Murine Model of Facial Paralysis

    Directory of Open Access Journals (Sweden)

    Diana Urrego

    2015-01-01

    Full Text Available This work was aimed at characterizing structural changes in primary motor cortex layer 5 pyramidal neurons and their relationship with microglial density induced by facial nerve lesion using a murine facial paralysis model. Adult transgenic mice, expressing green fluorescent protein in microglia and yellow fluorescent protein in projecting neurons, were submitted to either unilateral section of the facial nerve or sham surgery. Injured animals were sacrificed either 1 or 3weeks after surgery. Two-photon excitation microscopy was then used for evaluating both layer 5 pyramidal neurons and microglia in vibrissal primary motor cortex (vM1. It was found that facial nerve lesion induced long-lasting changes in the dendritic morphology of vM1 layer 5 pyramidal neurons and in their surrounding microglia. Dendritic arborization of the pyramidal cells underwent overall shrinkage. Apical dendrites suffered transient shortening while basal dendrites displayed sustained shortening. Moreover, dendrites suffered transient spine pruning. Significantly higher microglial cell density was found surrounding vM1 layer 5 pyramidal neurons after facial nerve lesion with morphological bias towards the activated phenotype. These results suggest that facial nerve lesions elicit active dendrite remodeling due to pyramidal neuron and microglia interaction, which could be the pathophysiological underpinning of some neuropathic motor sequelae in humans.

  4. Layer 5 Pyramidal Neurons' Dendritic Remodeling and Increased Microglial Density in Primary Motor Cortex in a Murine Model of Facial Paralysis

    Science.gov (United States)

    Urrego, Diana; Troncoso, Julieta; Múnera, Alejandro

    2015-01-01

    This work was aimed at characterizing structural changes in primary motor cortex layer 5 pyramidal neurons and their relationship with microglial density induced by facial nerve lesion using a murine facial paralysis model. Adult transgenic mice, expressing green fluorescent protein in microglia and yellow fluorescent protein in projecting neurons, were submitted to either unilateral section of the facial nerve or sham surgery. Injured animals were sacrificed either 1 or 3weeks after surgery. Two-photon excitation microscopy was then used for evaluating both layer 5 pyramidal neurons and microglia in vibrissal primary motor cortex (vM1). It was found that facial nerve lesion induced long-lasting changes in the dendritic morphology of vM1 layer 5 pyramidal neurons and in their surrounding microglia. Dendritic arborization of the pyramidal cells underwent overall shrinkage. Apical dendrites suffered transient shortening while basal dendrites displayed sustained shortening. Moreover, dendrites suffered transient spine pruning. Significantly higher microglial cell density was found surrounding vM1 layer 5 pyramidal neurons after facial nerve lesion with morphological bias towards the activated phenotype. These results suggest that facial nerve lesions elicit active dendrite remodeling due to pyramidal neuron and microglia interaction, which could be the pathophysiological underpinning of some neuropathic motor sequelae in humans. PMID:26064916

  5. Non-toxic engineered carbon nanodiamond concentrations induce oxidative/nitrosative stress, imbalance of energy metabolism, and mitochondrial dysfunction in microglial and alveolar basal epithelial cells.

    Science.gov (United States)

    Fresta, Claudia G; Chakraborty, Aishik; Wijesinghe, Manjula B; Amorini, Angela M; Lazzarino, Giacomo; Lazzarino, Giuseppe; Tavazzi, Barbara; Lunte, Susan M; Caraci, Filippo; Dhar, Prajnaparamita; Caruso, Giuseppe

    2018-02-14

    Engineered nanoparticles are finding a wide spectrum of biomedical applications, including drug delivery and capacity to trigger cytotoxic phenomena, potentially useful against tumor cells. The full understanding of their biosafety and interactions with cell processes is mandatory. Using microglial (BV-2) and alveolar basal epithelial (A549) cells, in this study we determined the effects of engineered carbon nanodiamonds (ECNs) on cell viability, nitric oxide (NO) and reactive oxygen species (ROS) production, as well as on energy metabolism. Particularly, we initially measured decrease in cell viability as a function of increasing ECNs doses, finding similar cytotoxic ECN effects in the two cell lines. Subsequently, using apparently non-cytotoxic ECN concentrations (2 µg/mL causing decrease in cell number < 5%) we determined NO and ROS production, and measured the concentrations of compounds related to energy metabolism, mitochondrial functions, oxido-reductive reactions, and antioxidant defences. We found that in both cell lines non-cytotoxic ECN concentrations increased NO and ROS production with sustained oxidative/nitrosative stress, and caused energy metabolism imbalance (decrease in high energy phosphates and nicotinic coenzymes) and mitochondrial malfunctioning (decrease in ATP/ADP ratio).These results underline the importance to deeply investigate the molecular and biochemical changes occurring upon the interaction of ECNs (and nanoparticles in general) with living cells, even at apparently non-toxic concentration. Since the use of ECNs in biomedical field is attracting increasing attention the complete evaluation of their biosafety, toxicity and/or possible side effects both in vitro and in vivo is mandatory before these highly promising tools might find the correct application.

  6. High content analysis of phagocytic activity and cell morphology with PuntoMorph

    DEFF Research Database (Denmark)

    Al-Ali, Hassan; Gao, Han; Dalby-Hansen, Camilla

    2017-01-01

    methods for quantifying phagocytic activity in multiple dimensions including speed, accuracy, and resolution. Conclusions We provide a framework to facilitate the development of high content assays suitable for drug screening. For convenience, we implemented our algorithm in a standalone software package...... with image-based quantification of phagocytic activity. New method We present a robust algorithm and cell-based assay system for high content analysis of phagocytic activity. The method utilizes fluorescently labeled beads as a phagocytic substrate with defined physical properties. The algorithm employs...... content screening. Results We tested our assay system using microglial cultures. Our results recapitulated previous findings on the effects of microglial stimulation on cell morphology and phagocytic activity. Moreover, our cell-level analysis revealed that the two phenotypes associated with microglial...

  7. Krüppel-like factor 4, a novel transcription factor regulates microglial activation and subsequent neuroinflammation

    Directory of Open Access Journals (Sweden)

    Das Sulagna

    2010-10-01

    Full Text Available Abstract Background Activation of microglia, the resident macrophages of the central nervous system (CNS, is the hallmark of neuroinflammation in neurodegenerative diseases and other pathological conditions associated with CNS infection. The activation of microglia is often associated with bystander neuronal death. Nuclear factor-κB (NF-κB is one of the important transcription factors known to be associated with microglial activation which upregulates the expression of inducible nitric oxide synthase (iNOS, cyclooxygenase-2 (Cox-2 and other pro-inflammatory cytokines. Recent studies have focused on the role of Krüppel-like factor 4 (Klf4, one of the zinc-finger transcription factors, in mediating inflammation. However, these studies were limited to peripheral system and its role in CNS is not understood. Our studies focused on the possible role of Klf4 in mediating CNS inflammation. Methods For in vitro studies, mouse microglial BV-2 cell lines were treated with 500 ng/ml Salmonella enterica lipopolysacchride (LPS. Brain tissues were isolated from BALB/c mice administered with 5 mg/kg body weight of LPS. Expressions of Klf4, Cox-2, iNOS and pNF-κB were evaluated using western blotting, quantitative real time PCR, and reverse transcriptase polymerase chain reactions (RT-PCRs. Klf4 knockdown was carried out using SiRNA specific for Klf4 mRNA and luciferase assays and electromobility shift assay (EMSA were performed to study the interaction of Klf4 to iNOS promoter elements in vitro. Co-immunoprecipitation of Klf4 and pNF-κB was done in order to study a possible interaction between the two transcription factors. Results LPS stimulation increased Klf4 expression in microglial cells in a time- and dose-dependent manner. Knockdown of Klf4 resulted in decreased levels of the pro-inflammatory cytokines TNF-α, MCP-1 and IL-6, along with a significant decrease in iNOS and Cox-2 expression. NO production also decreased as a result of Klf4 knockdown

  8. Microglial and macrophage reactions mark progressive changes and define the penumbra in the rat neocortex and striatum after transient middle cerebral artery occlusion

    DEFF Research Database (Denmark)

    Lehrmann, E; Christensen, Thomas; Zimmer, J

    1997-01-01

    Transient middle cerebral artery occlusion in rats leads to infarction of the lateral part of the striatum and adjacent neocortex, with selective neuronal necrosis in the bordering penumbral zones. Administration of glutamate, cytokine, and leukocyte antagonists have rescued mainly neocortical....../macrophages in the adjacent penumbra. Within the neocortex, a later onset of degeneration along the insular-parietal axis was marked by neuronal expression of heat shock protein and a progressive microglial activation with induction of the full repertoire of microglial activation markers, including a widespread microglial...

  9. Recurrent hypoinsulinemic hyperglycemia in neonatal rats increases PARP-1 and NF-κB expression and leads to microglial activation in the cerebral cortex.

    Science.gov (United States)

    Gisslen, Tate; Ennis, Kathleen; Bhandari, Vineet; Rao, Raghavendra

    2015-11-01

    Hyperglycemia is a common metabolic problem in extremely low-birth-weight preterm infants. Neonatal hyperglycemia is associated with increased mortality and brain injury. Glucose-mediated oxidative injury may be responsible. Poly(ADP-ribose) polymerase-1 (PARP-1) is a nuclear enzyme involved in DNA repair and cell survival. However, PARP-1 overactivation leads to cell death. NF-κB is coactivated with PARP-1 and regulates microglial activation. The effects of recurrent hyperglycemia on PARP-1/NF-κB expression and microglial activation are not well understood. Rat pups were subjected to recurrent hypoinsulinemic hyperglycemia of 2 h duration twice daily from postnatal (P) day 3-P12 and killed on P13. mRNA and protein expression of PARP-1/NF-κB and their downstream effectors were determined in the cerebral cortex. Microgliosis was determined using CD11 immunohistochemistry. Recurrent hyperglycemia increased PARP-1 expression confined to the nucleus and without causing PARP-1 overactivation and cell death. NF-κB mRNA expression was increased, while IκB mRNA expression was decreased. inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS), and neuronal nitric oxide synthase (nNOS) mRNA expressions were decreased. Hyperglycemia significantly increased the number of microglia. Recurrent hyperglycemia in neonatal rats is associated with upregulation of PARP-1 and NF-κB expression and subsequent microgliosis but not neuronal cell death in the cerebral cortex.

  10. Xenon Reduces Neuronal Hippocampal Damage and Alters the Pattern of Microglial Activation after Experimental Subarachnoid Hemorrhage: A Randomized Controlled Animal Trial

    Directory of Open Access Journals (Sweden)

    Michael Veldeman

    2017-09-01

    Full Text Available ObjectiveThe neuroprotective properties of the noble gas xenon have already been demonstrated using a variety of injury models. Here, we examine for the first time xenon’s possible effect in attenuating early brain injury (EBI and its influence on posthemorrhagic microglial neuroinflammation in an in vivo rat model of subarachnoid hemorrhage (SAH.MethodsSprague-Dawley rats (n = 22 were randomly assigned to receive either Sham surgery (n = 9; divided into two groups or SAH induction via endovascular perforation (n = 13, divided into two groups. Of those randomized for SAH, 7 animals were postoperatively ventilated with 50 vol% oxygen/50 vol% xenon for 1 h and 6 received 50 vol% oxygen/50 vol% nitrogen (control. The animals were sacrificed 24 h after SAH. Of each animal, a cerebral coronal section (−3.60 mm from bregma was selected for assessment of histological damage 24 h after SAH. A 5-point neurohistopathological severity score was applied to assess neuronal cell damage in H&E and NeuN stained sections in a total of four predefined anatomical regions of interest. Microglial activation was evaluated by a software-assisted cell count of Iba-1 stained slices in three cortical regions of interest.ResultsA diffuse cellular damage was apparent in all regions of the ipsilateral hippocampus 24 h after SAH. Xenon-treated animals presented with a milder damage after SAH. This effect was found to be particularly pronounced in the medial regions of the hippocampus, CA3 (p = 0.040, and dentate gyrus (DG p = 0.040. However, for the CA1 and CA2 regions, there were no statistical differences in neuronal damage according to our histological scoring. A cell count of activated microglia was lower in the cortex of xenon-treated animals. This difference was especially apparent in the left piriform cortex (p = 0.017.ConclusionIn animals treated with 50 vol% xenon (for 1 h after SAH, a less pronounced neuronal damage was

  11. miR-146a negatively regulates the induction of proinflammatory cytokines in response to Japanese encephalitis virus infection in microglial cells.

    Science.gov (United States)

    Deng, Minnan; Du, Ganqin; Zhao, Jiegang; Du, Xiaowei

    2017-06-01

    Increasing evidence confirms the involvement of virus infection and miRNA, such as miR-146a, in neuroinflammation-associated epilepsy. In the present study, we investigated the upregulation of miR-146a with RT-qPCR and in situ hybridization methods in a mice infection model of Japanese encephalitis virus (JEV) and in vitro. Subsequently we investigated the involvement of miR-146a in modulating JEV-induced neuroinflammation. It was demonstrated that JEV infection promoted miR-146a production in BALB/c mice brain and in cultured mouse microglial C8-B4 cells, along with pro-inflammatory cytokines, such as IL-1β, IL-6, TNF-α, IFN-β and IFN-α. We also found that miR-146a exerted negative regulatory effects upon IL-1β, IL-6, TNF-α, IFN-β and IFN-α in C8-B4 cells. Accordingly, miR-146a downregulation with a miR-146a inhibitor promoted the upregulation of IL-1β, IL-6, TNF-α, IFN-β and IFN-α, whereas miR-146a upregulation with miR-146a mimics reduced the upregulation of these cytokines. Moreover, miR-146a exerted no regulation upon JEV growth in C8-B4 cells. In conclusion, JEV infection upregulated miR-146a and pro-inflammatory cytokine production, in mice brain and in cultured C8-B4 cells. Furthermore, miR-146a negatively regulated the production of JEV-induced pro-inflammatory cytokines, in virus growth independent fashion, identifying miR-146a as a negative feedback regulator in JEV-induced neuroinflammation, and possibly in epilepsy.

  12. Protective Effects of α-Tocopherol, γ-Tocopherol and Oleic Acid, Three Compounds of Olive Oils, and No Effect of Trolox, on 7-Ketocholesterol-Induced Mitochondrial and Peroxisomal Dysfunction in Microglial BV-2 Cells

    Directory of Open Access Journals (Sweden)

    Meryam Debbabi

    2016-11-01

    Full Text Available Lipid peroxidation products, such as 7-ketocholesterol (7KC, may be increased in the body fluids and tissues of patients with neurodegenerative diseases and trigger microglial dysfunction involved in neurodegeneration. It is therefore important to identify synthetic and natural molecules able to impair the toxic effects of 7KC. We determined the impact of 7KC on murine microglial BV-2 cells, especially its ability to trigger mitochondrial and peroxisomal dysfunction, and evaluated the protective effects of α- and γ-tocopherol, Trolox, and oleic acid (OA. Multiple complementary chemical assays, flow cytometric and biochemical methods were used to evaluate the antioxidant and cytoprotective properties of these molecules. According to various complementary assays to estimate antioxidant activity, only α-, and γ-tocopherol, and Trolox had antioxidant properties. However, only α-tocopherol, γ-tocopherol and OA were able to impair 7KC-induced loss of mitochondrial transmembrane potential, which is associated with increased permeability to propidium iodide, an indicator of cell death. In addition, α-and γ-tocopherol, and OA were able to prevent the decrease in Abcd3 protein levels, which allows the measurement of peroxisomal mass, and in mRNA levels of Abcd1 and Abcd2, which encode for two transporters involved in peroxisomal β-oxidation. Thus, 7KC-induced side effects are associated with mitochondrial and peroxisomal dysfunction which can be inversed by natural compounds, thus supporting the hypothesis that the composition of the diet can act on the function of organelles involved in neurodegenerative diseases.

  13. T117

    Directory of Open Access Journals (Sweden)

    A. Alexandrova

    2015-11-01

    Full Text Available During cancer development, tumor cells gain the ability to invade and metastasize. Individual cells use alternative migration modes based on different cellular mechanisms. One of them is mesenchymal motility mode which is driven by leading edge protrusion in the form of filopodia or/and lamellipodia based on Arp2/3 dependent actin polymerization. Mesenchymal motility depends on formation of cell-substrate adhesions, activity of matrix metalloproteases (MMPs and on activity of small GTPaseRac. Another mode is amoeboid motility, which involves formation of blebs – hollow membrane protrusions extruded from the cell surface by actin-myosin contraction. Amoeboid motility does not need both pronounced cell-substrate adhesions and MMPs activity and required increase of activity of small GTPase Rho. Fibroblasts and scattered epithelial cells migrate by mesenchymal mode, while blood cells – lymphocytes or macrophages mainly use amoeboid mode for migration. It was shown that some treatments cause transition from one motility mode to another. Switches from mesenchymal to amoeboid motility and opposite are called mesenchymal-amoeboid transition (MAT and amoeboid -mesenchymal transition (AMT respectively. The ability of cells for such transitions was named as plasticity of migration. We compared the plasticity of migration of normal and tumor cells. To study plasticity of mesenchymally migrated cells (MAT we choose fibrosarcoma cells HT1080 as tumor and non-transformed subcutaneous fibroblasts 1036 as normal counterpart. To study AMT we choose a few lines of myeloid leukemia THP1, K562, KG1 in contrast to normal leukocytes obtained from healthy donors. We showed that fibrosarcoma cells in opposite to non-transformed fibroblasts could undergo MAT under treatments, which limited mesenchymal migration. Two approaches to limit mesenchymal motility of cells were used. One was decrease of substrate adhesiveness by treatment of coverslips with Poly

  14. Lipoxin A4 inhibits microglial activation and reduces neuroinflammation and neuropathic pain after spinal cord hemisection.

    Science.gov (United States)

    Martini, Alessandra Cadete; Berta, Temugin; Forner, Stefânia; Chen, Gang; Bento, Allisson Freire; Ji, Ru-Rong; Rae, Giles Alexander

    2016-04-08

    Spinal cord injury (SCI) is a severe neurological disorder with many disabling consequences, including persistent neuropathic pain, which develops in about 40 % of SCI patients and is induced and sustained by excessive and uncontrolled spinal neuroinflammation. Here, we have evaluated the effects of lipoxin A4 (LXA4), a member of a unique class of endogenous lipid mediators with both anti-inflammatory and analgesic properties, on spinal neuroinflammation and chronic pain in an experimental model of SCI. Spinal hemisection at T10 was carried out in adult male CD1 mice and Wistar rats. To test if LXA4 can reduce neuroinflammation and neuropathic pain, each animal received two intrathecal injections of LXA4 (300 pmol) or vehicle at 4 and 24 h after SCI. Sensitivity to mechanical stimulation of the hind paws was evaluated using von Frey monofilaments, and neuroinflammation was tested by measuring the mRNA and/or protein expression levels of glial markers and cytokines in the spinal cord samples after SCI. Also, microglia cultures prepared from murine cortical tissue were used to assess the direct effects of LXA4 on microglial activation and release of pro-inflammatory TNF-α. LXA4 treatment caused significant reductions in the intensity of mechanical pain hypersensitivity and spinal expression levels of microglial markers and pro-inflammatory cytokines induced by SCI, when compared to rodents receiving control vehicle injections. Notably, the increased expressions of the microglial marker IBA-1 and of the pro-inflammatory cytokine TNF-α were the most affected by the LXA4 treatment. Furthermore, cortical microglial cultures expressed ALX/FPR2 receptors for LXA4 and displayed potentially anti-inflammatory responses upon challenge with LXA4. Collectively, our results suggest that LXA4 can effectively modulate microglial activation and TNF-α release through ALX/FPR2 receptors, ultimately reducing neuropathic pain in rodents after spinal cord hemisection. The dual anti

  15. Peripheral formalin injection induces unique spinal cord microglial phenotypic changes

    Science.gov (United States)

    Fu, Kai-Yuan; Tan, Yong-Hui; Sung, Backil; Mao, Jianren

    2014-01-01

    Microglia are resident immune cells of brain and activated by peripheral tissue injury. In the present study, we investigated the possible induction of several microglial surface immunomolecules in the spinal cord, including leukocyte common antigen (LCA/CD45), MHC class I antigen, MHC class II antigen, Fc receptor, and CD11c following formalin injection into the rat’s hind paw. CD45 and MHC class I were upregulated in the activated microglia, which was evident on day 3 with the peak expression on day 7 following peripheral formalin injection. There was a very low basal expression of MHC class II, CD11c, and the Fc receptor, which did not change after the formalin injection. These results, for the first time, indicate that peripheral formalin injection can induce phenotypic changes of microglia with distinct upregulation of CD45 and MHC class I antigen. The data suggest that phenotypic changes of the activated microglia may be a unique pattern of central changes following peripheral tissue injury. PMID:19015000

  16. Huperzine A protects neural stem cells against Aβ-induced apoptosis in a neural stem cells and microglia co-culture system

    Science.gov (United States)

    Zhu, Ning; Lin, Jizong; Wang, Kewan; Wei, Meidan; Chen, Qingzhuang; Wang, Yong

    2015-01-01

    Objectives: This study aims to explore whether Huperzine A (HupA) could protect neural stem cells against amyloid beta-peptide Aβ induced apoptosis in a neural stem cells (NSCs) and microglia co-culture system. Methods: Rat NSCs and microglial cells were isolated, cultured and identified with immunofluorescence Assays (IFA). Co-culture systems of NSCs and microglial cells were employed using Transwell Permeable Supports. The effects of Aβ1-42 on NSCs were studied in 4 groups using co-culture systems: NSCs, Aβ+NSCs, co-culture and Aβ+co-culture groups. Bromodeoxyuridine (BrdU) incorporation and flow cytometry were utilized to assess the differences of proliferation, differentiation and apoptosis of NSCs between the groups. LQ test was performed to assess the amounts of IL-6, TNF-α and MIP-α secreted, and flow cytometry and Western blotting were used to assess apoptosis of NSCs and the expressions of Bcl-2 and Bax in each group. Results: IFA results showed that isolated rat NSCs were nestin-positive and microglial cells were CD11b/c-positive. Among all the groups, the Aβ+co-culture group has the lowest BrdU expression level, the lowest MAP2-positive, ChAT-positive cell counts and the highest NSC apoptosis rate. Smaller amounts of IL-6, TNF-α and MIP-α were being secreted by microglial cells in the HupA+Aβ+co-culture group compared with those in the Aβ+ co-culture group. Also the Bcl-2: Bax ratio was much higher in the HupA+Aβ+co-culture group than in the Aβ+co-culture group. Conclusions: HupA inhibits cell apoptosis through restraining microglia’s inflammatory response induced by Aβ1-42. PMID:26261518

  17. Hydroxychloroquine reduces microglial activity and attenuates experimental autoimmune encephalomyelitis.

    Science.gov (United States)

    Koch, Marcus W; Zabad, Rana; Giuliani, Fabrizio; Hader, Walter; Lewkonia, Ray; Metz, Luanne; Wee Yong, V

    2015-11-15

    Microglial activation is thought to be a key pathophysiological mechanism underlying disease activity in all forms of MS. Hydroxychloroquine (HCQ) is an antimalarial drug with immunomodulatory properties that is widely used in the treatment of rheumatological diseases. In this series of experiments, we explore the effect of HCQ on human microglial activation in vitro and on the development of experimental autoimmune encephalitis (EAE) in vivo. We activated human microglia with lipopolysaccharide (LPS), and measured concentrations of several pro- and anti-inflammatory cytokines in untreated and HCQ pretreated cultures. We investigated the effect of HCQ pretreatment at two doses on the development of EAE and spinal cord histology. HCQ pretreatment reduced the production of pro-inflammatory (TNF-alpha, IL-6, and IL-12) and anti-inflammatory (IL-10 and IL-1 receptor antagonist) cytokines in LPS-stimulated human microglia. HCQ pretreatment delayed the onset of EAE, and reduced the number of Iba-1 positive microglia/macrophages and signs of demyelination in the spinal cords of HCQ treated animals. HCQ treatment reduces the activation of human microglia in vitro, delays the onset of EAE, and decreases the representation of activated macrophages/microglia and demyelination in the spinal cord of treated mice. HCQ is a plausible candidate for further clinical studies in MS. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Human neuromelanin: an endogenous microglial activator for dopaminergic neuron death

    OpenAIRE

    Zhang, Wei; Zecca, Luigi; Wilson, Belinda; Ren, RW; Wang, Yong-jun; Wang, Xiao-min; Hong, Jau-Shyong

    2013-01-01

    Substantial evidence indicates that neuroinflammation caused by over-activation of microglial in the substantia nigra is critical in the pathogenesis of dopaminergic neurodegeneration in Parkinson’s disease (PD). Increasing data demonstrates that environmental factors such as rotenone, paraquat play pivotal roles in the death of dopaminergic neurons. Here, potential role and mechanism of neuromelanin (NM), a major endogenous component in dopaminergic neurons of the substantia nigra, on microg...

  19. Influence of extracellular zinc on M1 microglial activation.

    Science.gov (United States)

    Higashi, Youichirou; Aratake, Takaaki; Shimizu, Shogo; Shimizu, Takahiro; Nakamura, Kumiko; Tsuda, Masayuki; Yawata, Toshio; Ueba, Tetuya; Saito, Motoaki

    2017-02-27

    Extracellular zinc, which is released from hippocampal neurons in response to brain ischaemia, triggers morphological changes in microglia. Under ischaemic conditions, microglia exhibit two opposite activation states (M1 and M2 activation), which may be further regulated by the microenvironment. We examined the role of extracellular zinc on M1 activation of microglia. Pre-treatment of microglia with 30-60 μM ZnCl 2 resulted in dose-dependent increases in interleukin-1 beta (IL-1β), interleukin-6 (IL-6), and tumour necrosis factor-alpha (TNFα) secretion when M1 activation was induced by lipopolysaccharide administration. In contrast, the cell-permeable zinc chelator TPEN, the radical scavenger Trolox, and the P2X7 receptor antagonist A438079 suppressed the effects of zinc pre-treatment on microglia. Furthermore, endogenous zinc release was induced by cerebral ischaemia-reperfusion, resulting in increased expression of IL-1β, IL-6, TNFα, and the microglial M1 surface marker CD16/32, without hippocampal neuronal cell loss, in addition to impairments in object recognition memory. However, these effects were suppressed by the zinc chelator CaEDTA. These findings suggest that extracellular zinc may prime microglia to enhance production of pro-inflammatory cytokines via P2X7 receptor activation followed by reactive oxygen species generation in response to stimuli that trigger M1 activation, and that these inflammatory processes may result in deficits in object recognition memory.

  20. Microglial reactivity correlates to the density and the myelination of the anterogradely degenerating axons and terminals following perforant path denervation of the mouse fascia dentata

    DEFF Research Database (Denmark)

    Jensen, M B; Hegelund, I V; Rom Poulsen, Frantz

    1999-01-01

    Transection of the entorhino-dentate perforant path is a well known model for lesion-induced axonal sprouting and glial reactions in the rat. In this study, we have characterized the microglial reaction in the dentate molecular layer of the SJL/J and C57Bl/6 mouse. The morphological transformatio...... in the individual cases. The finding of a potentiated or accelerated microglial activation in the medial as compared to the lateral perforant path zone suggests different kinetics of microglial activation in areas with degenerating myelinated and unmyelinated fibers....

  1. Paeoniflorin Attenuates Inflammatory Pain by Inhibiting Microglial Activation and Akt-NF-κB Signaling in the Central Nervous System

    Directory of Open Access Journals (Sweden)

    Bo Hu

    2018-05-01

    Full Text Available Background/Aims: Paeoniflorin (PF is known to have anti-inflammatory and paregoric effects, but the mechanism underlying its analgesic effect remains unclear. The aim of this study was to clarify the effect of PF on Freund’s complete adjuvant (CFA-induced inflammatory pain and explore the underlying molecular mechanism. Methods: An inflammatory pain model was established by intraplantar injection of CFA in C57BL/6J mice. After intrathecal injection of PF daily for 8 consecutive days, thermal and mechanical withdrawal thresholds, the levels of inflammatory factors TNF-α, IL-1β and IL-6, microglial activity, and the expression of Akt-NF-κB signaling pathway in the spinal cord tissue were detected by animal ethological test, cell culture, enzyme-linked immunosorbent assay, immunofluorescence histochemistry, and western blot. Results: PF inhibited the spinal microglial activation in the CFA-induced pain model. The production of proinflammatory cytokines was decreased in the central nervous system after PF treatment both in vivo and in vitro. PF further displayed a remarkable effect on inhibiting the activation of Akt-NF-κB signaling pathway in vivo and in vitro. Conclusion: These results suggest that PF is a potential therapeutic agent for inflammatory pain and merits further investigation.

  2. Arachidonic acid containing phosphatidylcholine increases due to microglial activation in ipsilateral spinal dorsal horn following spared sciatic nerve injury.

    Directory of Open Access Journals (Sweden)

    Tomohiro Banno

    Full Text Available Peripheral nerve injury induces substantial molecular changes in the somatosensory system that leads to maladaptive plasticity and cause neuropathic pain. Understanding the molecular pathways responsible for the development of neuropathic pain is essential to the development of novel rationally designed therapeutics. Although lipids make up to half of the dry weight of the spinal cord, their relation with the development of neuropathic pain is poorly understood. We aimed to elucidate the regulation of spinal lipids in response to neuropathic peripheral nerve injury in mice by utilizing matrix-assisted laser desorption/ionization imaging mass spectrometry, which allows visualization of lipid distribution within the cord. We found that arachidonic acid (AA containing [PC(diacyl-16:0/20:4+K]+ was increased temporarily at superficial ipsilateral dorsal horn seven days after spared nerve injury (SNI. The spatiotemporal changes in lipid concentration resembled microglia activation as defined by ionized calcium binding adaptor molecule 1 (Iba1 immunohistochemistry. Suppression of microglial function through minocycline administration resulted in attenuation of hypersensitivity and reduces [PC(diacyl-16:0/20:4+K]+ elevation in the spinal dorsal horn. These data suggested that AA containing [PC(diacyl-16:0/20:4+K]+ is related to hypersensitivity evoked by SNI and implicate microglial cell activation in this lipid production.

  3. Paraquat and maneb co-exposure induces noradrenergic locus coeruleus neurodegeneration through NADPH oxidase-mediated microglial activation

    International Nuclear Information System (INIS)

    Hou, Liyan; Zhang, Cong; Wang, Ke; Liu, Xiaofang; Wang, Hongwei; Che, Yuning; Sun, Fuqiang; Zhou, Xueying; Zhao, Xiulan; Wang, Qingshan

    2017-01-01

    Highlights: • Microglial activation induced by paraquat and maneb precedes noradrenergic neurodegeneration in locus coeruleus. • NADPH oxidase activation contributes to microglia-mediated neuroinflammation and related noradrenergic neurodegeneration. • Inhibition of NADPH oxidase by apocynin protects noradrenergic neurons against paraquat and maneb-induced toxicity. - Abstract: Co-exposure to paraquat (PQ) and maneb (Mb) has been shown to increase the risk of Parkinson’s disease (PD) and dopaminergic (DA) neurodegeneration in the substantia nigra pars compacta (SNpc) is observed in PQ and Mb-treated experimental animals. The loss of noradrenergic locus coeruleus (LC/NE) neurons in brainstem is a common feature shared by multiple neurodegenerative diseases, including PD. However, whether PQ and Mb is able to damage LC/NE neurons remains undefined. In this study, mice treated with combined PQ and Mb displayed progressive LC/NE neurodegeneration. Time course studies revealed that the activation of microglia preceded LC/NE neurodegeneration. Mechanistically, the activation of NADPH oxidase contributed to microglial activation and subsequent LC/NE neurodegeneration. We found that PQ and Mb co-exposure induced activation of NADPH oxidase as shown by increased superoxide production and membrane translocation of p47 phox , a cytosolic subunit of NADPH oxidase. Inhibition of NADPH oxidase by apocynin, a widely used NADPH oxidase inhibitor, suppressed microglial activation and gene expressions of proinflammatory factors. Furthermore, reduced activation of nuclear factor-κB (NF-κB) pathway was observed in apocynin-treated mice. More importantly, inhibition of NADPH oxidase by apocynin afforded LC/NE neuroprotection against PQ and Mb-induced neurotoxicity. Thus, our findings revealed the critical role NADPH oxidase-mediated microglial activation in driving LC/NE neurodegeneration induced by PQ and Mb, providing new insights into the pathogenesis of environmental

  4. Proteomic analysis of the effects of aged garlic extract and its FruArg component on lipopolysaccharide-induced neuroinflammatory response in microglial cells.

    Directory of Open Access Journals (Sweden)

    Hui Zhou

    Full Text Available Aged garlic extract (AGE is widely used as a dietary supplement, and is claimed to promote human health through anti-oxidant/anti-inflammatory activities with hypolipidemic, antiplatelet and neuroprotective effects. Prior studies of AGE have mainly focused on its organosulfur compounds, with little attention paid to its carbohydrate derivatives, such as N-α-(1-deoxy-D-fructos-1-yl-L-arginine (FruArg. The goal of this study is to investigate actions of AGE and FruArg on antioxidative and neuroinflammatory responses in lipopolysaccharide (LPS-activated murine BV-2 microglial cells using a proteomic approach. Our data show that both AGE and FruArg can significantly inhibit LPS-induced nitric oxide (NO production in BV-2 cells. Quantitative proteomic analysis by combining two dimensional differential in-gel electrophoresis (2D-DIGE with mass spectrometry revealed that expressions of 26 proteins were significantly altered upon LPS exposure, while levels of 20 and 21 proteins exhibited significant changes in response to AGE and FruArg treatments, respectively, in LPS-stimulated BV-2 cells. Notably, approximate 78% of the proteins responding to AGE and FruArg treatments are in common, suggesting that FruArg is a major active component of AGE. MULTICOM-PDCN and Ingenuity Pathway Analyses indicate that the proteins differentially affected by treatment with AGE and FruArg are involved in inflammatory responses and the Nrf2-mediated oxidative stress response. Collectively, these results suggest that AGE and FruArg attenuate neuroinflammatory responses and promote resilience in LPS-activated BV-2 cells by suppressing NO production and by regulating expression of multiple protein targets associated with oxidative stress.

  5. Progressive retinal degeneration and glial activation in the CLN6 (nclf mouse model of neuronal ceroid lipofuscinosis: a beneficial effect of DHA and curcumin supplementation.

    Directory of Open Access Journals (Sweden)

    Myriam Mirza

    Full Text Available Neuronal ceroid lipofuscinosis (NCL is a group of neurodegenerative lysosomal storage disorders characterized by vision loss, mental and motor deficits, and spontaneous seizures. Neuropathological analyses of autopsy material from NCL patients and animal models revealed brain atrophy closely associated with glial activity. Earlier reports also noticed loss of retinal cells and reactive gliosis in some forms of NCL. To study this phenomenon in detail, we analyzed the ocular phenotype of CLN6 (nclf mice, an established mouse model for variant-late infantile NCL. Retinal morphometry, immunohistochemistry, optokinetic tracking, electroretinography, and mRNA expression were used to characterize retinal morphology and function as well as the responses of Müller cells and microglia. Our histological data showed a severe and progressive degeneration in the CLN6 (nclf retina co-inciding with reactive Müller glia. Furthermore, a prominent phenotypic transformation of ramified microglia to phagocytic, bloated, and mislocalized microglial cells was identified in CLN6 (nclf retinas. These events overlapped with a rapid loss of visual perception and retinal function. Based on the strong microglia reactivity we hypothesized that dietary supplementation with immuno-regulatory compounds, curcumin and docosahexaenoic acid (DHA, could ameliorate microgliosis and reduce retinal degeneration. Our analyses showed that treatment of three-week-old CLN6 (nclf mice with either 5% DHA or 0.6% curcumin for 30 weeks resulted in a reduced number of amoeboid reactive microglia and partially improved retinal function. DHA-treatment also improved the morphology of CLN6 (nclf retinas with a preserved thickness of the photoreceptor layer in most regions of the retina. Our results suggest that microglial reactivity closely accompanies disease progression in the CLN6 (nclf retina and both processes can be attenuated with dietary supplemented immuno-modulating compounds.

  6. Electroacupuncture ameliorating post-stroke cognitive impairments via inhibition of peri-infarct astroglial and microglial/macrophage P2 purinoceptors-mediated neuroinflammation and hyperplasia.

    Science.gov (United States)

    Huang, Jia; You, Xiaofang; Liu, Weilin; Song, Changming; Lin, Xiaomin; Zhang, Xiufeng; Tao, Jing; Chen, Lidian

    2017-10-10

    During ischemic stroke (IS), adenosine 5'-triphosphate (ATP) is released from damaged nerve cells of the infract core region to the extracellular space, invoking peri-infarct glial cellular P2 purinoceptors singling, and causing pro-inflammatory cytokine secretion, which is likely to initiate or aggravate motor and cognitive impairment. It has been proved that electroacupuncture (EA) is an effective and safe strategy used in anti-inflammation. However, EA for the role of purine receptors in the central nervous system has not yet been reported. Ischemia-reperfusion injured rat model was induced by middle cerebral artery occlusion and reperfusion (MCAO/R). EA treatment at the DU 20 and DU 24 acupoints treatment were conducted to rats from the 12 h after MCAO/R injury for consecutive 7 days. The neurological outcomes, infarction volumes and the level of astroglial and microglial/macrophage hyperplasia, inflammatory cytokine and P2X7R and P2Y1R expression in the peri-infarct hippocampal CA1and sensorimotor cortex were investigated after IS to evaluate the MCAO/R model and therapeutic mechanism of EA treatment. EA effectively reduced the level of pro-inflammatory cytokine interleukin-1β (IL-1β) as evidenced by reduction in astroglial and microglial/macrophage hyperplasia and the levels of P2X7R and ED1, P2X7R and GFAP, P2Y1R and ED1, P2Y1R and GFAP co-expression in peri-infarct hippocampal CA1 and sensorimotor cortex compared with that of MCAO/R model and Non-EA treatment, accompanied by the improved neurological deficit and the motor and memory impairment outcomes. Therefore, our data support the hypothesis that EA could exert its anti-inflammatory effect via inhibiting the astroglial and microglial/macrophage P2 purinoceptors (P2X7R and P2Y1R)-mediated neuroinflammation after MCAO/R injury. Astroglial and microglial/macrophage P2 purinoceptors-mediated neuroinflammation and hyperplasia in peri-infarct hippocampal CA1 and sensorimotor cortex were attenuated by EA

  7. Sinomenine, a natural dextrorotatory morphinan analog, is anti-inflammatory and neuroprotective through inhibition of microglial NADPH oxidase

    Directory of Open Access Journals (Sweden)

    Wilson Belinda

    2007-09-01

    Full Text Available Abstract Background The mechanisms involved in the induction and regulation of inflammation resulting in dopaminergic (DA neurotoxicity in Parkinson's disease (PD are complex and incompletely understood. Microglia-mediated inflammation has recently been implicated as a critical mechanism responsible for progressive neurodegeneration. Methods Mesencephalic neuron-glia cultures and reconstituted cultures were used to investigate the molecular mechanisms of sinomenine (SN-mediated anti-inflammatory and neuroprotective effects in both the lipopolysaccharide (LPS- and the 1-methyl-4-phenylpyridinium (MPP+-mediated models of PD. Results SN showed equivalent efficacy in protecting against DA neuron death in rat midbrain neuron-glial cultures at both micro- and sub-picomolar concentrations, but no protection was seen at nanomolar concentrations. The neuroprotective effect of SN was attributed to inhibition of microglial activation, since SN significantly decreased tumor necrosis factor-α (TNF-α, prostaglandin E2 (PGE2 and reactive oxygen species (ROS production by microglia. In addition, from the therapeutic point of view, we focused on sub-picomolar concentration of SN for further mechanistic studies. We found that 10-14 M of SN failed to protect DA neurons against MPP+-induced toxicity in the absence of microglia. More importantly, SN failed to show a protective effect in neuron-glia cultures from mice lacking functional NADPH oxidase (PHOX, a key enzyme for extracellular superoxide production in immune cells. Furthermore, we demonstrated that SN reduced LPS-induced extracellular ROS production through the inhibition of the PHOX cytosolic subunit p47phoxtranslocation to the cell membrane. Conclusion Our findings strongly suggest that the protective effects of SN are most likely mediated through the inhibition of microglial PHOX activity. These findings suggest a novel therapy to treat inflammation-mediated neurodegenerative diseases.

  8. Accelerated microglial pathology is associated with Aβ plaques in mouse models of Alzheimer's disease

    DEFF Research Database (Denmark)

    Baron, Rona; Babcock, Alicia A; Nemirovsky, Anna

    2014-01-01

    Microglia integrate within the neural tissue with a distinct ramified morphology through which they scan the surrounding neuronal network. Here, we used a digital tool for the quantitative morphometric characterization of fine cortical microglial structures in mice, and the changes they undergo w...

  9. Imaging Microglial Activation in Untreated First-Episode Psychosis: A PET Study With [18F]FEPPA.

    Science.gov (United States)

    Hafizi, Sina; Tseng, Huai-Hsuan; Rao, Naren; Selvanathan, Thiviya; Kenk, Miran; Bazinet, Richard P; Suridjan, Ivonne; Wilson, Alan A; Meyer, Jeffrey H; Remington, Gary; Houle, Sylvain; Rusjan, Pablo M; Mizrahi, Romina

    2017-02-01

    Neuroinflammation and abnormal immune responses are increasingly implicated in the pathophysiology of schizophrenia. Previous positron emission tomography (PET) studies targeting the translocator protein 18 kDa (TSPO) have been limited by high nonspecific binding of the first-generation radioligand, low-resolution scanners, small sample sizes, and psychotic patients being on antipsychotics or not being in the first episode of their illness. The present study uses the novel second-generation TSPO PET radioligand [ 18 F]FEPPA to evaluate whether microglial activation is elevated in the dorsolateral prefrontal cortex and hippocampus of untreated patients with first-episode psychosis. Nineteen untreated patients with first-episode psychosis (14 of them antipsychotic naive) and 20 healthy volunteers underwent a high-resolution [ 18 F]FEPPA PET scan and MRI. Dynamic PET data were analyzed using the validated two-tissue compartment model with arterial plasma input function with total volume of distribution (V T ) as outcome measure. All analyses were corrected for TSPO rs6971 polymorphism (which is implicated in differential binding affinity). No significant differences were observed between patients and healthy volunteers in microglial activation, as indexed by [ 18 F]FEPPA V T , in either the dorsolateral prefrontal cortex or the hippocampus. There were no significant correlations between [ 18 F]FEPPA V T and duration of illness, clinical presentation, or neuropsychological measures after adjusting for multiple testing. The lack of significant differences in [ 18 F]FEPPA V T between groups suggests that microglial activation is not present in first-episode psychosis.

  10. Does microglial dysfunction play a role in autism and Rett syndrome?

    Science.gov (United States)

    Maezawa, Izumi; Calafiore, Marco; Wulff, Heike; Jin, Lee-Way

    2011-02-01

    Autism spectrum disorders (ASDs) including classic autism is a group of complex developmental disabilities with core deficits of impaired social interactions, communication difficulties and repetitive behaviors. Although the neurobiology of ASDs has attracted much attention in the last two decades, the role of microglia has been ignored. Existing data are focused on their recognized role in neuroinflammation, which only covers a small part of the pathological repertoire of microglia. This review highlights recent findings on the broader roles of microglia, including their active surveillance of brain microenvironments and regulation of synaptic connectivity, maturation of brain circuitry and neurogenesis. Emerging evidence suggests that microglia respond to pre- and postnatal environmental stimuli through epigenetic interface to change gene expression, thus acting as effectors of experience-dependent synaptic plasticity. Impairments of these microglial functions could substantially contribute to several major etiological factors of autism, such as environmental toxins and cortical underconnectivity. Our recent study on Rett syndrome, a syndromic autistic disorder, provides an example that intrinsic microglial dysfunction due to genetic and epigenetic aberrations could detrimentally affect the developmental trajectory without evoking neuroinflammation. We propose that ASDs provide excellent opportunities to study the influence of microglia on neurodevelopment, and this knowledge could lead to novel therapies.

  11. Inhibitory effect of a tyrosine-fructose Maillard reaction product, 2,4-bis(p-hydroxyphenyl-2-butenal on amyloid-β generation and inflammatory reactions via inhibition of NF-κB and STAT3 activation in cultured astrocytes and microglial BV-2 cells

    Directory of Open Access Journals (Sweden)

    Choi Im Seup

    2011-10-01

    Full Text Available Abstract Background Amyloidogenesis is linked to neuroinflammation. The tyrosine-fructose Maillard reaction product, 2,4-bis(p-hydroxyphenyl-2-butenal, possesses anti-inflammatory properties in cultured macrophages, and in an arthritis animal model. Because astrocytes and microglia are responsible for amyloidogenesis and inflammatory reactions in the brain, we investigated the anti-inflammatory and anti-amyloidogenic effects of 2,4-bis(p-hydroxyphenyl-2-butenal in lipopolysaccharide (LPS-stimulated astrocytes and microglial BV-2 cells. Methods Cultured astrocytes and microglial BV-2 cells were treated with LPS (1 μg/ml for 24 h, in the presence (1, 2, 5 μM or absence of 2,4-bis(p-hydroxyphenyl-2-butenal, and harvested. We performed molecular biological analyses to determine the levels of inflammatory and amyloid-related proteins and molecules, cytokines, Aβ, and secretases activity. Nuclear factor-kappa B (NF-κB DNA binding activity was determined using gel mobility shift assays. Results We found that 2,4-bis(p-hydroxyphenyl-2-butenal (1, 2, 5 μM suppresses the expression of inducible nitric oxide synthase (iNOS and cyclooxygenase-2 (COX-2 as well as the production of nitric oxide (NO, reactive oxygen species (ROS, tumor necrosis factor-α (TNF-α, and interleukin-1β (IL-1β in LPS (1 μg/ml-stimulated astrocytes and microglial BV-2 cells. Further, 2,4-bis(p-hydroxyphenyl-2-butenal inhibited the transcriptional and DNA binding activity of NF-κB--a transcription factor that regulates genes involved in neuroinflammation and amyloidogenesis via inhibition of IκB degradation as well as nuclear translocation of p50 and p65. Consistent with the inhibitory effect on inflammatory reactions, 2,4-bis(p-hydroxyphenyl-2-butenal inhibited LPS-elevated Aβ42 levels through attenuation of β- and γ-secretase activities. Moreover, studies using signal transducer and activator of transcription 3 (STAT3 siRNA and a pharmacological inhibitor showed that 2

  12. Ultrafine carbon particles promote rotenone-induced dopamine neuronal loss through activating microglial NADPH oxidase

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yinxi; Liu, Dan; Zhang, Huifeng; Wang, Yixin [Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, 100191 (China); Wei, Ling [Beijing Center for Physical & Chemical Analysis, Beijing 100089 (China); Liu, Yutong [School of Life Science, Beijing Normal University, Beijing 100875 (China); Liao, Jieying [Department of Translational Medicine, Xiamen Institute of Rare Earth Materials, Chinese Academy of Sciences, Xiamen 361024 (China); Gao, Hui-Ming [Model Animal Research Center of Nanjing University, Nanjing 211800 (China); Zhou, Hui, E-mail: hardhui@gmail.com [Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, 100191 (China)

    2017-05-01

    Background: Atmospheric ultrafine particles (UFPs) and pesticide rotenone were considered as potential environmental risk factors for Parkinson's disease (PD). However, whether and how UFPs alone and in combination with rotenone affect the pathogenesis of PD remains largely unknown. Methods: Ultrafine carbon black (ufCB, a surrogate of UFPs) and rotenone were used individually or in combination to determine their roles in chronic dopaminergic (DA) loss in neuron-glia, and neuron-enriched, mix-glia cultures. Immunochemistry using antibody against tyrosine hydroxylase was performed to detect DA neuronal loss. Measurement of extracellular superoxide and intracellular reactive oxygen species (ROS) were performed to examine activation of NADPH oxidase. Genetic deletion and pharmacological inhibition of NADPH oxidase and MAC-1 receptor in microglia were employed to examine their role in DA neuronal loss triggered by ufCB and rotenone. Results: In rodent midbrain neuron-glia cultures, ufCB and rotenone alone caused neuronal death in a dose-dependent manner. In particularly, ufCB at doses of 50 and 100 μg/cm{sup 2} induced significant loss of DA neurons. More importantly, nontoxic doses of ufCB (10 μg/cm{sup 2}) and rotenone (2 nM) induced synergistic toxicity to DA neurons. Microglial activation was essential in this process. Furthermore, superoxide production from microglial NADPH oxidase was critical in ufCB/rotenone-induced neurotoxicity. Studies in mix-glia cultures showed that ufCB treatment activated microglial NADPH oxidase to induce superoxide production. Firstly, ufCB enhanced the expression of NADPH oxidase subunits (gp91{sup phox}, p47{sup phox} and p40{sup phox}); secondly, ufCB was recognized by microglial surface MAC-1 receptor and consequently promoted rotenone-induced p47{sup phox} and p67{sup phox} translocation assembling active NADPH oxidase. Conclusion: ufCB and rotenone worked in synergy to activate NADPH oxidase in microglia, leading to

  13. Ultrafine carbon particles promote rotenone-induced dopamine neuronal loss through activating microglial NADPH oxidase

    International Nuclear Information System (INIS)

    Wang, Yinxi; Liu, Dan; Zhang, Huifeng; Wang, Yixin; Wei, Ling; Liu, Yutong; Liao, Jieying; Gao, Hui-Ming; Zhou, Hui

    2017-01-01

    Background: Atmospheric ultrafine particles (UFPs) and pesticide rotenone were considered as potential environmental risk factors for Parkinson's disease (PD). However, whether and how UFPs alone and in combination with rotenone affect the pathogenesis of PD remains largely unknown. Methods: Ultrafine carbon black (ufCB, a surrogate of UFPs) and rotenone were used individually or in combination to determine their roles in chronic dopaminergic (DA) loss in neuron-glia, and neuron-enriched, mix-glia cultures. Immunochemistry using antibody against tyrosine hydroxylase was performed to detect DA neuronal loss. Measurement of extracellular superoxide and intracellular reactive oxygen species (ROS) were performed to examine activation of NADPH oxidase. Genetic deletion and pharmacological inhibition of NADPH oxidase and MAC-1 receptor in microglia were employed to examine their role in DA neuronal loss triggered by ufCB and rotenone. Results: In rodent midbrain neuron-glia cultures, ufCB and rotenone alone caused neuronal death in a dose-dependent manner. In particularly, ufCB at doses of 50 and 100 μg/cm 2 induced significant loss of DA neurons. More importantly, nontoxic doses of ufCB (10 μg/cm 2 ) and rotenone (2 nM) induced synergistic toxicity to DA neurons. Microglial activation was essential in this process. Furthermore, superoxide production from microglial NADPH oxidase was critical in ufCB/rotenone-induced neurotoxicity. Studies in mix-glia cultures showed that ufCB treatment activated microglial NADPH oxidase to induce superoxide production. Firstly, ufCB enhanced the expression of NADPH oxidase subunits (gp91 phox , p47 phox and p40 phox ); secondly, ufCB was recognized by microglial surface MAC-1 receptor and consequently promoted rotenone-induced p47 phox and p67 phox translocation assembling active NADPH oxidase. Conclusion: ufCB and rotenone worked in synergy to activate NADPH oxidase in microglia, leading to oxidative damage to DA neurons. Our

  14. Protective effects of geniposide and ginsenoside Rg1 combination treatment on rats following cerebral ischemia are mediated via microglial microRNA‑155‑5p inhibition.

    Science.gov (United States)

    Wang, Jun; Li, Dan; Hou, Jincai; Lei, Hongtao

    2018-02-01

    Geniposide, an active component of Gardenia, has been reported to protect against cerebral ischemia in animals. Ginsenoside Rg1, a component of Panax notoginseng, is usually administered in combination with Gardenia for the treatment of acute ischemic stroke; however, there are unknown effects of ginsenoside Rg1 that require further investigation. In the present study, the effects of geniposide and ginsensoide Rg1 combination treatment on focal cerebral ischemic stroke were investigated. For in vivo analysis, male rats were separated into three groups, including the (control), model and geniposide + ginsenoside Rg1 groups (n=8 per group). A middle cerebral artery occlusion model was established as the model group. The treatment group was treated with geniposide (30 mg/kg, tail vein injection) + ginsenoside Rg1 (6 mg/kg, tail vein injection), and the model group received saline instead. Neurobehavioral deficits, infarct volume, brain edema, and the expression of microRNA (miR)‑155‑5p and CD11b by reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) and immunohistochemistry, were assessed following 24 h of ischemia. For in vitro analysis, BV2 mouse microglial cells were cultured and exposed to geniposide (40 µg/ml) + ginsenoside Rg1 (8 µg/ml) during various durations of oxygen‑glucose deprivation (OGD). The expression levels of miR‑155‑5p, pri‑miR‑155 and pre‑miR‑155 were detected by RT‑qPCR. The results demonstrated that increases in brain infarct volume, edema volume, CD11b‑positive cells and miR‑155‑5p levels were alleviated following geniposide + ginsenoside administration in rats exposed to ischemia. Furthermore, geniposide + ginsenoside Rg1 treatment suppressed the miR‑155‑5p, pri‑miR‑155 and pre‑miR‑155 expression levels in OGD‑injured BV2 microglial cells. The results of the present study demonstrated that tail vein administration of geniposide in combination with ginsenoside Rg1

  15. The role of MAC1 in diesel exhaust particle-induced microglial activation and loss of dopaminergic neuron function.

    Science.gov (United States)

    Levesque, Shannon; Taetzsch, Thomas; Lull, Melinda E; Johnson, Jo Anne; McGraw, Constance; Block, Michelle L

    2013-06-01

    Increasing reports support that air pollution causes neuroinflammation and is linked to central nervous system (CNS) disease/damage. Diesel exhaust particles (DEP) are a major component of urban air pollution, which has been linked to microglial activation and Parkinson's disease-like pathology. To begin to address how DEP may exert CNS effects, microglia and neuron-glia cultures were treated with either nanometer-sized DEP (neuron function was assessed. All three treatments showed enhanced ameboid microglia morphology, increased H2 O2 production, and decreased DA uptake. Mechanistic inquiry revealed that the scavenger receptor inhibitor fucoidan blocked DEP internalization in microglia, but failed to alter DEP-induced H2 O2 production in microglia. However, pre-treatment with the MAC1/CD11b inhibitor antibody blocked microglial H2 O2 production in response to DEP. MAC1(-/-) mesencephalic neuron-glia cultures were protected from DEP-induced loss of DA neuron function, as measured by DA uptake. These findings support that DEP may activate microglia through multiple mechanisms, where scavenger receptors regulate internalization of DEP and the MAC1 receptor is mandatory for both DEP-induced microglial H2 O2 production and loss of DA neuron function. © 2013 International Society for Neurochemistry.

  16. Naringenin is a novel inhibitor of Dictyostelium cell proliferation and cell migration

    International Nuclear Information System (INIS)

    Russ, Misty; Martinez, Raquel; Ali, Hind; Steimle, Paul A.

    2006-01-01

    Naringenin is a flavanone compound that alters critical cellular processes such as cell multiplication, glucose uptake, and mitochondrial activity. In this study, we used the social amoeba, Dictyostelium discoideum, as a model system for examining the cellular processes and signaling pathways affected by naringenin. We found that naringenin inhibited Dictyostelium cell division in a dose-dependent manner (IC 5 ∼ 20 μM). Assays of Dictyostelium chemotaxis and multicellular development revealed that naringenin possesses a previously unrecognized ability to suppress amoeboid cell motility. We also found that naringenin, which is known to inhibit phosphatidylinositol 3-kinase activity, had no apparent effect on phosphatidylinositol 3,4,5-trisphosphate synthesis in live Dictyostelium cells; suggesting that this compound suppresses cell growth and migration via alternative signaling pathways. In another context, the discoveries described here highlight the value of using the Dictyostelium model system for identifying and characterizing the mechanisms by which naringenin, and related compounds, exert their effects on eukaryotic cells

  17. Antibody-Mediated Targeting of Tau In Vivo Does Not Require Effector Function and Microglial Engagement

    Directory of Open Access Journals (Sweden)

    Seung-Hye Lee

    2016-08-01

    Full Text Available The spread of tau pathology correlates with cognitive decline in Alzheimer’s disease. In vitro, tau antibodies can block cell-to-cell tau spreading. Although mechanisms of anti-tau function in vivo are unknown, effector function might promote microglia-mediated clearance. In this study, we investigated whether antibody effector function is required for targeting tau. We compared efficacy in vivo and in vitro of two versions of the same tau antibody, with and without effector function, measuring tau pathology, neuron health, and microglial function. Both antibodies reduced accumulation of tau pathology in Tau-P301L transgenic mice and protected cultured neurons against extracellular tau-induced toxicity. Only the full-effector antibody enhanced tau uptake in cultured microglia, which promoted release of proinflammatory cytokines. In neuron-microglia co-cultures, only effectorless anti-tau protected neurons, suggesting full-effector tau antibodies can induce indirect toxicity via microglia. We conclude that effector function is not required for efficacy, and effectorless tau antibodies may represent a safer approach to targeting tau.

  18. Studies of the phase gradient at the boundary of the phase diffusion equation, motivated by peculiar wave patterns of rhythmic contraction in the amoeboid movement of Physarum polycephalum

    Science.gov (United States)

    Iima, Makoto; Kori, Hiroshi; Nakagaki, Toshiyuki

    2017-04-01

    The boundary of a cell is the interface with its surroundings and plays a key role in controlling the cell movement adaptations to different environments. We propose a study of the boundary effects on the patterns and waves of the rhythmic contractions in plasmodia of Physarum polycephalum, a tractable model organism of the amoeboid type. Boundary effects are defined as the effects of both the boundary conditions and the boundary shape. The rhythmicity of contraction can be modulated by local stimulation of temperature, light and chemicals, and by local deformation of cell shape via mechanosensitive ion channels as well. First, we examined the effects of boundary cell shapes in the case of a special shape resembling a tadpole, while requiring that the natural frequency in the proximity of the boundary is slightly higher and uniform. The simulation model reproduced the approximate propagated wave, from the tail to the head, while the inward waves were observed only near the periphery of the head section of the tadpole-shape. A key finding was that the frequency of the rhythmic contractions depended on the local shape of cell boundary. This implies that the boundary conditions of the phase were not always homogeneous. To understand the dependency, we reduced the two-dimensional model into a one-dimensional continuum model with Neumann boundary conditions. Here, the boundary conditions reflect the frequency distribution at the boundary. We described the analytic solutions and calculated the relationship between the boundary conditions and the wave propagation for a one-dimensional model of the continuous oscillatory field and a discrete coupled oscillator system. The results obtained may not be limited to cell movement of Physarum, but may be applicable to the other physical systems since the analysis used a generic phase diffusion equation.

  19. Studies of the phase gradient at the boundary of the phase diffusion equation, motivated by peculiar wave patterns of rhythmic contraction in the amoeboid movement of Physarum polycephalum

    International Nuclear Information System (INIS)

    Iima, Makoto; Kori, Hiroshi; Nakagaki, Toshiyuki

    2017-01-01

    The boundary of a cell is the interface with its surroundings and plays a key role in controlling the cell movement adaptations to different environments. We propose a study of the boundary effects on the patterns and waves of the rhythmic contractions in plasmodia of Physarum polycephalum , a tractable model organism of the amoeboid type. Boundary effects are defined as the effects of both the boundary conditions and the boundary shape. The rhythmicity of contraction can be modulated by local stimulation of temperature, light and chemicals, and by local deformation of cell shape via mechanosensitive ion channels as well. First, we examined the effects of boundary cell shapes in the case of a special shape resembling a tadpole, while requiring that the natural frequency in the proximity of the boundary is slightly higher and uniform. The simulation model reproduced the approximate propagated wave, from the tail to the head, while the inward waves were observed only near the periphery of the head section of the tadpole-shape. A key finding was that the frequency of the rhythmic contractions depended on the local shape of cell boundary. This implies that the boundary conditions of the phase were not always homogeneous. To understand the dependency, we reduced the two-dimensional model into a one-dimensional continuum model with Neumann boundary conditions. Here, the boundary conditions reflect the frequency distribution at the boundary. We described the analytic solutions and calculated the relationship between the boundary conditions and the wave propagation for a one-dimensional model of the continuous oscillatory field and a discrete coupled oscillator system. The results obtained may not be limited to cell movement of Physarum , but may be applicable to the other physical systems since the analysis used a generic phase diffusion equation. (paper)

  20. Distinctive response of CNS glial cells in oro-facial pain associated with injury, infection and inflammation

    Directory of Open Access Journals (Sweden)

    Ribeiro-da-Silva Alfredo

    2010-11-01

    Full Text Available Abstract Oro-facial pain following injury and infection is frequently observed in dental clinics. While neuropathic pain evoked by injury associated with nerve lesion has an involvement of glia/immune cells, inflammatory hyperalgesia has an exaggerated sensitization mediated by local and circulating immune mediators. To better understand the contribution of central nervous system (CNS glial cells in these different pathological conditions, in this study we sought to characterize functional phenotypes of glial cells in response to trigeminal nerve injury (loose ligation of the mental branch, infection (subcutaneous injection of lipopolysaccharide-LPS and to sterile inflammation (subcutaneous injection of complete Freund's adjuvant-CFA on the lower lip. Each of the three insults triggered a specific pattern of mechanical allodynia. In parallel with changes in sensory response, CNS glial cells reacted distinctively to the challenges. Following ligation of the mental nerve, both microglia and astrocytes in the trigeminal nuclear complex were highly activated, more prominent in the principal sensory nucleus (Pr5 and subnucleus caudalis (Sp5C area. Microglial response was initiated early (days 3-14, followed by delayed astrocytes activation (days 7-28. Although the temporal profile of microglial and astrocyte reaction corresponded respectively to the initiation and chronic stage of neuropathic pain, these activated glial cells exhibited a low profile of cytokine expression. Local injection of LPS in the lower lip skin also triggered a microglial reaction in the brain, which started in the circumventricular organs (CVOs at 5 hours post-injection and diffused progressively into the brain parenchyma at 48 hours. This LPS-induced microglial reaction was accompanied by a robust induction of IκB-α mRNA and pro-inflammatory cytokines within the CVOs. However, LPS induced microglial activation did not specifically occur along the pain signaling pathway. In

  1. Equol, a Dietary Daidzein Gut Metabolite Attenuates Microglial Activation and Potentiates Neuroprotection In Vitro

    Directory of Open Access Journals (Sweden)

    Lalita Subedi

    2017-02-01

    Full Text Available Estrogen deficiency has been well characterized in inflammatory disorders including neuroinflammation. Daidzein, a dietary alternative phytoestrogen found in soy (Glycine max as primary isoflavones, possess anti‐inflammatory activity, but the effect of its active metabolite Equol (7‐hydroxy‐3‐(4′‐hydroxyphenyl‐chroman has not been well established. In this study, we investigated the anti‐neuroinflammatory and neuroprotective effect of Equol in vitro. To evaluate the potential effects of Equol, three major types of central nervous system (CNS cells, including microglia (BV‐2, astrocytes (C6, and neurons (N2a, were used. Effects of Equol on the expression of inducible nitric oxide synthase (iNOS, cyclooxygenase (COX‐2, Mitogen activated protein kinase (MAPK signaling proteins, and apoptosis‐related proteins were measured by western blot analysis. Equol inhibited the lipopolysaccharide (LPS‐induced TLR4 activation, MAPK activation, NF‐kB‐mediated transcription of inflammatory mediators, production of nitric oxide (NO, release of prostaglandin E2 (PGE‐2, secretion of tumor necrosis factor‐α (TNF‐α and interleukin 6 (IL‐6, in Lipopolysaccharide (LPS‐activated murine microglia cells. Additionally, Equol protects neurons from neuroinflammatory injury mediated by LPS‐activated microglia through downregulation of neuronal apoptosis, increased neurite outgrowth in N2a cell and neurotrophins like nerve growth factor (NGF production through astrocytes further supporting its neuroprotective potential. These findings provide novel insight into the anti‐neuroinflammatory effects of Equol on microglial cells, which may have clinical significance in cases of neurodegeneration.

  2. Computational Identification of Potential Multi-drug Combinations for Reduction of Microglial Inflammation in Alzheimer Disease

    Directory of Open Access Journals (Sweden)

    Thomas J. Anastasio

    2015-06-01

    Full Text Available Like other neurodegenerative diseases, Alzheimer Disease (AD has a prominent inflammatory component mediated by brain microglia. Reducing microglial inflammation could potentially halt or at least slow the neurodegenerative process. A major challenge in the development of treatments targeting brain inflammation is the sheer complexity of the molecular mechanisms that determine whether microglia become inflammatory or take on a more neuroprotective phenotype. The process is highly multifactorial, raising the possibility that a multi-target/multi-drug strategy could be more effective than conventional monotherapy. This study takes a computational approach in finding combinations of approved drugs that are potentially more effective than single drugs in reducing microglial inflammation in AD. This novel approach exploits the distinct advantages of two different computer programming languages, one imperative and the other declarative. Existing programs written in both languages implement the same model of microglial behavior, and the input/output relationships of both programs agree with each other and with data on microglia over an extensive test battery. Here the imperative program is used efficiently to screen the model for the most efficacious combinations of 10 drugs, while the declarative program is used to analyze in detail the mechanisms of action of the most efficacious combinations. Of the 1024 possible drug combinations, the simulated screen identifies only 7 that are able to move simulated microglia at least 50% of the way from a neurotoxic to a neuroprotective phenotype. Subsequent analysis shows that of the 7 most efficacious combinations, 2 stand out as superior both in strength and reliability. The model offers many experimentally testable and therapeutically relevant predictions concerning effective drug combinations and their mechanisms of action.

  3. Computational identification of potential multi-drug combinations for reduction of microglial inflammation in Alzheimer disease.

    Science.gov (United States)

    Anastasio, Thomas J

    2015-01-01

    Like other neurodegenerative diseases, Alzheimer Disease (AD) has a prominent inflammatory component mediated by brain microglia. Reducing microglial inflammation could potentially halt or at least slow the neurodegenerative process. A major challenge in the development of treatments targeting brain inflammation is the sheer complexity of the molecular mechanisms that determine whether microglia become inflammatory or take on a more neuroprotective phenotype. The process is highly multifactorial, raising the possibility that a multi-target/multi-drug strategy could be more effective than conventional monotherapy. This study takes a computational approach in finding combinations of approved drugs that are potentially more effective than single drugs in reducing microglial inflammation in AD. This novel approach exploits the distinct advantages of two different computer programming languages, one imperative and the other declarative. Existing programs written in both languages implement the same model of microglial behavior, and the input/output relationships of both programs agree with each other and with data on microglia over an extensive test battery. Here the imperative program is used efficiently to screen the model for the most efficacious combinations of 10 drugs, while the declarative program is used to analyze in detail the mechanisms of action of the most efficacious combinations. Of the 1024 possible drug combinations, the simulated screen identifies only 7 that are able to move simulated microglia at least 50% of the way from a neurotoxic to a neuroprotective phenotype. Subsequent analysis shows that of the 7 most efficacious combinations, 2 stand out as superior both in strength and reliability. The model offers many experimentally testable and therapeutically relevant predictions concerning effective drug combinations and their mechanisms of action.

  4. Anti-Inflammatory and Cytoprotective Effects of TMC-256C1 from Marine-Derived Fungus Aspergillus sp. SF-6354 via up-Regulation of Heme Oxygenase-1 in Murine Hippocampal and Microglial Cell Lines

    Directory of Open Access Journals (Sweden)

    Dong-Cheol Kim

    2016-04-01

    Full Text Available In the course of searching for bioactive secondary metabolites from marine fungi, TMC-256C1 was isolated from an ethyl acetate extract of the marine-derived fungus Aspergillus sp. SF6354. TMC-256C1 displayed anti-neuroinflammatory effect in BV2 microglial cells induced by lipopolysaccharides (LPS as well as neuroprotective effect against glutamate-stimulated neurotoxicity in mouse hippocampal HT22 cells. TMC-256C1 was shown to develop a cellular resistance to oxidative damage caused by glutamate-induced cytotoxicity and reactive oxygen species (ROS generation in HT22 cells, and suppress the inflammation process in LPS-stimulated BV2 cells. Furthermore, the neuroprotective and anti-neuroinflammatory activities of TMC-256C1 were associated with upregulated expression of heme oxygenase (HO-1 and nuclear translocation of nuclear factor-E2-related factor 2 (Nrf2 in HT22 and BV2 cells. We also found that TMC-256C1 activated p38 mitogen-activated protein kinases (MAPK and phosphatidylinositol 3-kinase (PI3K/Akt signaling pathways in HT22 and BV2 cells. These results demonstrated that TMC-256C1 activates HO-1 protein expression, probably by increasing nuclear Nrf2 levels via the activation of the p38 MAPK and PI3K/Akt pathways.

  5. Key role for spinal dorsal horn microglial kinin B1 receptor in early diabetic pain neuropathy

    Directory of Open Access Journals (Sweden)

    Couture Réjean

    2010-06-01

    Full Text Available Abstract Background The pro-nociceptive kinin B1 receptor (B1R is upregulated on sensory C-fibres, astrocytes and microglia in the spinal cord of streptozotocin (STZ-diabetic rat. This study aims at defining the role of microglial kinin B1R in diabetic pain neuropathy. Methods Sprague-Dawley rats were made diabetic with STZ (65 mg/kg, i.p., and 4 days later, two specific inhibitors of microglial cells (fluorocitrate, 1 nmol, i.t.; minocycline, 10 mg/kg, i.p. were administered to assess the impact on thermal hyperalgesia, allodynia and mRNA expression (qRT-PCR of B1R and pro-inflammatory markers. Spinal B1R binding sites ((125I-HPP-desArg10-Hoe 140 were also measured by quantitative autoradiography. Inhibition of microglia was confirmed by confocal microscopy with the specific marker Iba-1. Effects of intrathecal and/or systemic administration of B1R agonist (des-Arg9-BK and antagonists (SSR240612 and R-715 were measured on neuropathic pain manifestations. Results STZ-diabetic rats displayed significant tactile and cold allodynia compared with control rats. Intrathecal or peripheral blockade of B1R or inhibition of microglia reversed time-dependently tactile and cold allodynia in diabetic rats without affecting basal values in control rats. Microglia inhibition also abolished thermal hyperalgesia and the enhanced allodynia induced by intrathecal des-Arg9-BK without affecting hyperglycemia in STZ rats. The enhanced mRNA expression (B1R, IL-1β, TNF-α, TRPV1 and Iba-1 immunoreactivity in the STZ spinal cord were normalized by fluorocitrate or minocycline, yet B1R binding sites were reduced by 38%. Conclusion The upregulation of kinin B1R in spinal dorsal horn microglia by pro-inflammatory cytokines is proposed as a crucial mechanism in early pain neuropathy in STZ-diabetic rats.

  6. Chronic ethanol intake induces partial microglial activation that is not reversed by long-term ethanol withdrawal in the rat hippocampal formation.

    Science.gov (United States)

    Cruz, Catarina; Meireles, Manuela; Silva, Susana M

    2017-05-01

    Neuroinflammation has been implicated in the pathogenesis of several disorders. Activation of microglia leads to the release of pro-inflammatory mediators and microglial-mediated neuroinflammation has been proposed as one of the alcohol-induced neuropathological mechanisms. The present study aimed to examine the effect of chronic ethanol exposure and long-term withdrawal on microglial activation and neuroinflammation in the hippocampal formation. Male rats were submitted to 6 months of ethanol treatment followed by a 2-month withdrawal period. Stereological methods were applied to estimate the total number of microglia and activated microglia detected by CD11b immunohistochemistry in the hippocampal formation. The expression levels of the pro-inflammatory cytokines TNF-α, COX-2 and IL-15 were measured by qRT-PCR. Alcohol consumption was associated with an increase in the total number of activated microglia but morphological assessment indicated that microglia did not exhibit a full activation phenotype. These data were supported by functional evidence since chronic alcohol consumption produced no changes in the expression of TNF-α or COX-2. The levels of IL-15 a cytokine whose expression is increased upon activation of both astrocytes and microglia, was induced by chronic alcohol treatment. Importantly, the partial activation of microglia induced by ethanol was not reversed by long-term withdrawal. This study suggests that chronic alcohol exposure induces a microglial phenotype consistent with partial activation without significant increase in classical cytokine markers of neuroinflammation in the hippocampal formation. Furthermore, long-term cessation of alcohol intake is not sufficient to alter the microglial partial activation phenotype induced by ethanol. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Non-cell autonomous impairment of oligodendrocyte differentiation precedes CNS degeneration in the Zitter rat: Implications of macrophage/microglial activation in the pathogenesis

    Directory of Open Access Journals (Sweden)

    Ookawara Shigeo

    2008-04-01

    Full Text Available Abstract Background The zitter (zi/zi rat, a loss-of-function mutant of the glycosylated transmembrane protein attractin (atrn, exhibits widespread age-dependent spongiform degeneration, hypomyelination, and abnormal metabolism of reactive oxygen species (ROS in the brain. To date, the mechanisms underlying these phenotypes have remained unclear. Results Here, we show differentiation defects in zi/zi oligodendrocytes, accompanied by aberrant extension of cell-processes and hypomyelination. Axonal bundles were relatively preserved during postnatal development. With increasing in age, the injured oligodendrocytes in zi/zi rats become pathological, as evidenced by the accumulation of iron in their cell bodies. Immunohistochemical analysis revealed that atrn expression was absent from an oligodendrocyte lineage, including A2B5-positive progenitors and CNPase-positive differentiated cells. The number and distribution of Olig2-positive oligodendrocyte progenitors was unchanged in the zi/zi brain. Furthermore, an in vitro differentiation assay of cultured oligodendrocyte progenitors prepared from zi/zi brains revealed their normal competence for proliferation and differentiation into mature oligodendrocytes. Interestingly, we demonstrated the accelerated recruitment of ED1-positive macrophages/microglia to the developing zi/zi brain parenchyma prior to the onset of hypomyelination. Semiquantitative RT-PCR analysis revealed a significant up-regulation of CD26 and IL1-β in the zi/zi brain during this early postnatal stage. Conclusion We demonstrated that the onset of the impairment of oligodendrocyte differentiation occurs in a non-cell autonomous manner in zi/zi rats. Hypomyelination of oligodendrocytes was not due to a failure of the intrinsic program of oligodendrocytes, but rather, was caused by extrinsic factors that interrupt oligodendrocyte development. It is likely that macrophage/microglial activation in the zi/zi CNS leads to disturbances in

  8. Diverse Brain Myeloid Expression Profiles Reveal Distinct Microglial Activation States and Aspects of Alzheimer’s Disease Not Evident in Mouse Models

    Directory of Open Access Journals (Sweden)

    Brad A. Friedman

    2018-01-01

    Full Text Available Microglia, the CNS-resident immune cells, play important roles in disease, but the spectrum of their possible activation states is not well understood. We derived co-regulated gene modules from transcriptional profiles of CNS myeloid cells of diverse mouse models, including new tauopathy model datasets. Using these modules to interpret single-cell data from an Alzheimer’s disease (AD model, we identified microglial subsets—distinct from previously reported “disease-associated microglia”—expressing interferon-related or proliferation modules. We then analyzed whole-tissue RNA profiles from human neurodegenerative diseases, including a new AD dataset. Correcting for altered cellular composition of AD tissue, we observed elevated expression of the neurodegeneration-related modules, but also modules not implicated using expression profiles from mouse models alone. We provide a searchable, interactive database for exploring gene expression in all these datasets (http://research-pub.gene.com/BrainMyeloidLandscape. Understanding the dimensions of CNS myeloid cell activation in human disease may reveal opportunities for therapeutic intervention.

  9. Neonatal L-glutamine modulates anxiety-like behavior, cortical spreading depression, and microglial immunoreactivity: analysis in developing rats suckled on normal size- and large size litters.

    Science.gov (United States)

    de Lima, Denise Sandrelly Cavalcanti; Francisco, Elian da Silva; Lima, Cássia Borges; Guedes, Rubem Carlos Araújo

    2017-02-01

    In mammals, L-glutamine (Gln) can alter the glutamate-Gln cycle and consequently brain excitability. Here, we investigated in developing rats the effect of treatment with different doses of Gln on anxiety-like behavior, cortical spreading depression (CSD), and microglial activation expressed as Iba1-immunoreactivity. Wistar rats were suckled in litters with 9 and 15 pups (groups L 9 and L 15 ; respectively, normal size- and large size litters). From postnatal days (P) 7-27, the animals received Gln per gavage (250, 500 or 750 mg/kg/day), or vehicle (water), or no treatment (naive). At P28 and P30, we tested the animals, respectively, in the elevated plus maze and open field. At P30-35, we measured CSD parameters (velocity of propagation, amplitude, and duration). Fixative-perfused brains were processed for microglial immunolabeling with anti-IBA-1 antibodies to analyze cortical microglia. Rats treated with Gln presented an anxiolytic behavior and accelerated CSD propagation when compared to the water- and naive control groups. Furthermore, CSD velocity was higher (p litter sizes, and for microglial activation in the L 15 groups. Besides confirming previous electrophysiological findings (CSD acceleration after Gln), our data demonstrate for the first time a behavioral and microglial activation that is associated with early Gln treatment in developing animals, and that is possibly operated via changes in brain excitability.

  10. Cocaine promotes oxidative stress and microglial-macrophage activation in rat cerebellum

    Directory of Open Access Journals (Sweden)

    Rosa M López-Pedrajas

    2015-07-01

    Full Text Available Different mechanisms have been suggested for cocaine neurotoxicity, including oxidative stress alterations. Nuclear factor kappa B (NF-κB, considered a sensor of oxidative stress and inflammation, is involved in drug toxicity and addiction. NF-κB is a key mediator for immune responses that induces microglial/macrophage activation under inflammatory processes and neuronal injury/degeneration. Although cerebellum is commonly associated to motor control, muscular tone and balance. Its relation with addiction is getting relevance, being associated to compulsive and perseverative behaviors. Some reports indicate that cerebellar microglial activation induced by cannabis or ethanol, promote cerebellar alterations and these alterations could be associated to addictive-related behaviors. After considering the effects of some drugs on cerebellum, the aim of the present work analyzes pro-inflammatory changes after cocaine exposure. Rats received daily 15 mg/kg cocaine i.p. for 18 days. Reduced and oxidized forms of glutathione (GSH and GSSG, glutathione peroxidase (GPx activity and glutamate were determined in cerebellar homogenates. NF-κB activity, CD68 and GFAP expression were determined.Cerebellar GPx activity and GSH/GSSG ratio are significantly decreased after cocaine exposure. A significant increase of glutamate concentration is also observed. Interestingly, increased NF-κB activity is also accompanied by an increased expression of the lysosomal mononuclear phagocytic marker ED1 without GFAP alterations.Current trends in addiction biology are focusing on the role of cerebellum on addictive behaviors. Cocaine-induced cerebellar changes described herein fit with previosus data showing cerebellar alterations on addict subjects and support the proposed role of cerebelum in addiction.

  11. Effects of chemokine (C–C motif) ligand 1 on microglial function

    International Nuclear Information System (INIS)

    Akimoto, Nozomi; Ifuku, Masataka; Mori, Yuki; Noda, Mami

    2013-01-01

    Highlights: •CCR8, a specific receptor for CCL-1, was expressed on primary cultured microglia. •Expression of CCR-8 in microglia was upregulated in the presence of CCL-1. •CCL-1 increased motility, proliferation and phagocytosis of cultured microglia. •CCL-1promoted BDNF and IL-6 mRNA, and the release of NO from microglia. •CCL-1 activates microglia and may contribute to the development of neuropathic pain. -- Abstract: Microglia, which constitute the resident macrophages of the central nervous system (CNS), are generally considered as the primary immune cells in the brain and spinal cord. Microglial cells respond to various factors which are produced following nerve injury of multiple aetiologies and contribute to the development of neuronal disease. Chemokine (C–C motif) ligand 1 (CCL-1), a well-characterized chemokine secreted by activated T cells, has been shown to play an important role in neuropathic pain induced by nerve injury and is also produced in various cell types in the CNS, especially in dorsal root ganglia (DRG). However, the role of CCL-1 in the CNS and the effects on microglia remains unclear. Here we showed the multiple effects of CCL-1 on microglia. We first showed that CCR-8, a specific receptor for CCL-1, was expressed on primary cultured microglia, as well as on astrocytes and neurons, and was upregulated in the presence of CCL-1. CCL-1 at concentration of 1 ng/ml induced chemotaxis, increased motility at a higher concentration (100 ng/ml), and increased proliferation and phagocytosis of cultured microglia. CCL-1 also activated microglia morphologically, promoted mRNA levels for brain-derived neurotrophic factor (BDNF) and IL-6, and increased the release of nitrite from microglia. These indicate that CCL-1 has a role as a mediator in neuron-glia interaction, which may contribute to the development of neurological diseases, especially in neuropathic pain

  12. Effects of chemokine (C–C motif) ligand 1 on microglial function

    Energy Technology Data Exchange (ETDEWEB)

    Akimoto, Nozomi [Laboratory of Pathophysiology, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Ifuku, Masataka [Laboratory of Integrative Physiology, Graduate School of Medicine, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Mori, Yuki [Laboratory of Pathophysiology, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Noda, Mami, E-mail: noda@phar.kyushu-u.ac.jp [Laboratory of Pathophysiology, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan)

    2013-07-05

    Highlights: •CCR8, a specific receptor for CCL-1, was expressed on primary cultured microglia. •Expression of CCR-8 in microglia was upregulated in the presence of CCL-1. •CCL-1 increased motility, proliferation and phagocytosis of cultured microglia. •CCL-1promoted BDNF and IL-6 mRNA, and the release of NO from microglia. •CCL-1 activates microglia and may contribute to the development of neuropathic pain. -- Abstract: Microglia, which constitute the resident macrophages of the central nervous system (CNS), are generally considered as the primary immune cells in the brain and spinal cord. Microglial cells respond to various factors which are produced following nerve injury of multiple aetiologies and contribute to the development of neuronal disease. Chemokine (C–C motif) ligand 1 (CCL-1), a well-characterized chemokine secreted by activated T cells, has been shown to play an important role in neuropathic pain induced by nerve injury and is also produced in various cell types in the CNS, especially in dorsal root ganglia (DRG). However, the role of CCL-1 in the CNS and the effects on microglia remains unclear. Here we showed the multiple effects of CCL-1 on microglia. We first showed that CCR-8, a specific receptor for CCL-1, was expressed on primary cultured microglia, as well as on astrocytes and neurons, and was upregulated in the presence of CCL-1. CCL-1 at concentration of 1 ng/ml induced chemotaxis, increased motility at a higher concentration (100 ng/ml), and increased proliferation and phagocytosis of cultured microglia. CCL-1 also activated microglia morphologically, promoted mRNA levels for brain-derived neurotrophic factor (BDNF) and IL-6, and increased the release of nitrite from microglia. These indicate that CCL-1 has a role as a mediator in neuron-glia interaction, which may contribute to the development of neurological diseases, especially in neuropathic pain.

  13. PET imaging of putative microglial activation in individuals at ultra-high risk for psychosis, recently diagnosed and chronically ill with schizophrenia.

    Science.gov (United States)

    Di Biase, M A; Zalesky, A; O'keefe, G; Laskaris, L; Baune, B T; Weickert, C S; Olver, J; McGorry, P D; Amminger, G P; Nelson, B; Scott, A M; Hickie, I; Banati, R; Turkheimer, F; Yaqub, M; Everall, I P; Pantelis, C; Cropley, V

    2017-08-29

    We examined putative microglial activation as a function of illness course in schizophrenia. Microglial activity was quantified using [ 11 C](R)-(1-[2-chrorophynyl]-N-methyl-N-[1-methylpropyl]-3 isoquinoline carboxamide ( 11 C-(R)-PK11195) positron emission tomography (PET) in: (i) 10 individuals at ultra-high risk (UHR) of psychosis; (ii) 18 patients recently diagnosed with schizophrenia; (iii) 15 patients chronically ill with schizophrenia; and, (iv) 27 age-matched healthy controls. Regional-binding potential (BP ND ) was calculated using the simplified reference-tissue model with four alternative reference inputs. The UHR, recent-onset and chronic patient groups were compared to age-matched healthy control groups to examine between-group BP ND differences in 6 regions: dorsal frontal, orbital frontal, anterior cingulate, medial temporal, thalamus and insula. Correlation analysis tested for BP ND associations with gray matter volume, peripheral cytokines and clinical variables. The null hypothesis of equality in BP ND between patients (UHR, recent-onset and chronic) and respective healthy control groups (younger and older) was not rejected for any group comparison or region. Across all subjects, BP ND was positively correlated to age in the thalamus (r=0.43, P=0.008, false discovery rate). No correlations with regional gray matter, peripheral cytokine levels or clinical symptoms were detected. We therefore found no evidence of microglial activation in groups of individuals at high risk, recently diagnosed or chronically ill with schizophrenia. While the possibility of 11 C-(R)-PK11195-binding differences in certain patient subgroups remains, the patient cohorts in our study, who also displayed normal peripheral cytokine profiles, do not substantiate the assumption of microglial activation in schizophrenia as a regular and defining feature, as measured by 11 C-(R)-PK11195 BP ND .

  14. Directed Differentiation of Human Pluripotent Stem Cells to Microglia

    Directory of Open Access Journals (Sweden)

    Panagiotis Douvaras

    2017-06-01

    Full Text Available Microglia, the immune cells of the brain, are crucial to proper development and maintenance of the CNS, and their involvement in numerous neurological disorders is increasingly being recognized. To improve our understanding of human microglial biology, we devised a chemically defined protocol to generate human microglia from pluripotent stem cells. Myeloid progenitors expressing CD14/CX3CR1 were generated within 30 days of differentiation from both embryonic and induced pluripotent stem cells (iPSCs. Further differentiation of the progenitors resulted in ramified microglia with highly motile processes, expressing typical microglial markers. Analyses of gene expression and cytokine release showed close similarities between iPSC-derived (iPSC-MG and human primary microglia as well as clear distinctions from macrophages. iPSC-MG were able to phagocytose and responded to ADP by producing intracellular Ca2+ transients, whereas macrophages lacked such response. The differentiation protocol was highly reproducible across several pluripotent stem cell lines.

  15. Microarray and pathway analysis reveal distinct mechanisms underlying cannabinoid-mediated modulation of LPS-induced activation of BV-2 microglial cells.

    Directory of Open Access Journals (Sweden)

    Ana Juknat

    Full Text Available Cannabinoids are known to exert immunosuppressive activities. However, the mechanisms which contribute to these effects are unknown. Using lipopolysaccharide (LPS to activate BV-2 microglial cells, we examined how Δ(9-tetrahydrocannabinol (THC, the major psychoactive component of marijuana, and cannabidiol (CBD the non-psychoactive component, modulate the inflammatory response. Microarray analysis of genome-wide mRNA levels was performed using Illumina platform and the resulting expression patterns analyzed using the Ingenuity Pathway Analysis to identify functional subsets of genes, and the Ingenuity System Database to denote the gene networks regulated by CBD and THC. From the 5338 transcripts that were differentially expressed across treatments, 400 transcripts were found to be upregulated by LPS, 502 by CBD+LPS and 424 by THC+LPS, while 145 were downregulated by LPS, 297 by CBD+LPS and 149 by THC+LPS, by 2-fold or more (p≤0.005. Results clearly link the effects of CBD and THC to inflammatory signaling pathways and identify new cannabinoid targets in the MAPK pathway (Dusp1, Dusp8, Dusp2, cell cycle related (Cdkn2b, Gadd45a as well as JAK/STAT regulatory molecules (Socs3, Cish, Stat1. The impact of CBD on LPS-stimulated gene expression was greater than that of THC. We attribute this difference to the fact that CBD highly upregulated several genes encoding negative regulators of both NFκB and AP-1 transcriptional activities, such as Trib3 and Dusp1 known to be modulated through Nrf2 activation. The CBD-specific expression profile reflected changes associated with oxidative stress and glutathione depletion via Trib3 and expression of ATF4 target genes. Furthermore, the CBD affected genes were shown to be controlled by nuclear factors usually involved in regulation of stress response and inflammation, mainly via Nrf2/Hmox1 axis and the Nrf2/ATF4-Trib3 pathway. These observations indicate that CBD, and less so THC, induce a cellular stress

  16. Minocycline counter-regulates pro-inflammatory microglia responses in the retina and protects from degeneration.

    Science.gov (United States)

    Scholz, Rebecca; Sobotka, Markus; Caramoy, Albert; Stempfl, Thomas; Moehle, Christoph; Langmann, Thomas

    2015-11-17

    Microglia reactivity is a hallmark of retinal degenerations and overwhelming microglial responses contribute to photoreceptor death. Minocycline, a semi-synthetic tetracycline analog, has potent anti-inflammatory and neuroprotective effects. Here, we investigated how minocycline affects microglia in vitro and studied its immuno-modulatory properties in a mouse model of acute retinal degeneration using bright white light exposure. LPS-treated BV-2 microglia were stimulated with 50 μg/ml minocycline for 6 or 24 h, respectively. Pro-inflammatory gene transcription was determined by real-time RT-PCR and nitric oxide (NO) secretion was assessed using the Griess reagent. Caspase 3/7 levels were determined in 661W photoreceptors cultured with microglia-conditioned medium in the absence or presence of minocycline supplementation. BALB/cJ mice received daily intraperitoneal injections of 45 mg/kg minocycline, starting 1 day before exposure to 15.000 lux white light for 1 hour. The effect of minocycline treatment on microglial reactivity was analyzed by immunohistochemical stainings of retinal sections and flat-mounts, and messenger RNA (mRNA) expression of microglia markers was determined using real-time RT-PCR and RNA-sequencing. Optical coherence tomography (OCT) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) stainings were used to measure the extent of retinal degeneration and photoreceptor apoptosis. Stimulation of LPS-activated BV-2 microglia with minocycline significantly diminished the transcription of the pro-inflammatory markers CCL2, IL6, and inducible nitric oxide synthase (iNOS). Minocycline also reduced the production of NO and dampened microglial neurotoxicity on 661W photoreceptors. Furthermore, minocycline had direct protective effects on 661W photoreceptors by decreasing caspase 3/7 activity. In mice challenged with white light, injections of minocycline strongly decreased the number of amoeboid alerted microglia in the outer

  17. Transduced PEP-1-PON1 proteins regulate microglial activation and dopaminergic neuronal death in a Parkinson's disease model.

    Science.gov (United States)

    Kim, Mi Jin; Park, Meeyoung; Kim, Dae Won; Shin, Min Jea; Son, Ora; Jo, Hyo Sang; Yeo, Hyeon Ji; Cho, Su Bin; Park, Jung Hwan; Lee, Chi Hern; Kim, Duk-Soo; Kwon, Oh-Shin; Kim, Joon; Han, Kyu Hyung; Park, Jinseu; Eum, Won Sik; Choi, Soo Young

    2015-09-01

    Parkinson's disease (PD) is an oxidative stress-mediated neurodegenerative disorder caused by selective dopaminergic neuronal death in the midbrain substantia nigra. Paraoxonase 1 (PON1) is a potent inhibitor of low-density lipoprotein (LDL) and high-density lipoprotein (HDL) against oxidation by destroying biologically active phospholipids with potential protective effects against oxidative stress-induced inflammatory disorders. In a previous study, we constructed protein transduction domain (PTD) fusion PEP-1-PON1 protein to transduce PON1 into cells and tissue. In this study, we examined the role of transduced PEP-1-PON1 protein in repressing oxidative stress-mediated inflammatory response in microglial BV2 cells after exposure to lipopolysaccharide (LPS). Moreover, we identified the functions of transduced PEP-1-PON1 proteins which include, mitigating mitochondrial damage, decreasing reactive oxidative species (ROS) production, matrix metalloproteinase-9 (MMP-9) expression and protecting against 1-methyl-4-phenylpyridinium (MPP(+))-induced neurotoxicity in SH-SY5Y cells. Furthermore, transduced PEP-1-PON1 protein reduced MMP-9 expression and protected against dopaminergic neuronal cell death in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mice model. Taken together, these results suggest a promising therapeutic application of PEP-1-PON1 proteins against PD and other inflammation and oxidative stress-related neuronal diseases. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Dopamine inhibits lipopolysaccharide-induced nitric oxide production through the formation of dopamine quinone in murine microglia BV-2 cells

    Directory of Open Access Journals (Sweden)

    Yasuhiro Yoshioka

    2016-02-01

    Full Text Available Dopamine (DA has been suggested to modulate functions of glial cells including microglial cells. To reveal the regulatory role of DA in microglial function, in the present study, we investigated the effect of DA on lipopolysaccharide (LPS-induced nitric oxide (NO production in murine microglial cell line BV-2. Pretreatment with DA for 24 h concentration-dependently attenuated LPS-induced NO production in BV-2 cells. The inhibitory effect of DA on LPS-induced NO production was not inhibited by SCH-23390 and sulpiride, D1-like and D2-like DA receptor antagonists, respectively. In addition, pretreatment with (−-(6aR,12bR-4,6,6a,7,8,12b-Hexahydro-7-methylindolo[4,3-a]phenanthridin (CY 208–243 and bromocriptine, D1-like and D2-like DA receptor agonists, respectively, did not affect the LPS-induced NO production. N-Acetylcysteine, which inhibits DA oxidation, completely inhibited the effect of DA. Tyrosinase, which catalyzes the oxidation of DA to DA quionone (DAQ, accelerated the inhibitory effect of DA on LPS-induced NO production. These results suggest that DA attenuates LPS-induced NO production through the formation of DAQ in BV-2 cells.

  19. Effects of a Standardized Phenolic-Enriched Maple Syrup Extract on β-Amyloid Aggregation, Neuroinflammation in Microglial and Neuronal Cells, and β-Amyloid Induced Neurotoxicity in Caenorhabditis elegans.

    Science.gov (United States)

    Ma, Hang; DaSilva, Nicholas A; Liu, Weixi; Nahar, Pragati P; Wei, Zhengxi; Liu, Yongqiang; Pham, Priscilla T; Crews, Rebecca; Vattem, Dhiraj A; Slitt, Angela L; Shaikh, Zahir A; Seeram, Navindra P

    2016-11-01

    Published data supports the neuroprotective effects of several phenolic-containing natural products, including certain fruit, berries, spices, nuts, green tea, and olive oil. However, limited data are available for phenolic-containing plant-derived natural sweeteners including maple syrup. Herein, we investigated the neuroprotective effects of a chemically standardized phenolic-enriched maple syrup extract (MSX) using a combination of biophysical, in vitro, and in vivo studies. Based on biophysical data (Thioflavin T assay, transmission electron microscopy, circular dichroism, dynamic light scattering, and zeta potential), MSX reduced amyloid β 1-42 peptide (Aβ 1-42 ) fibrillation in a concentration-dependent manner (50-500 μg/mL) with similar effects as the neuroprotective polyphenol, resveratrol, at its highest test concentration (63.5 % at 500 μg/mL vs. 77.3 % at 50 μg/mL, respectively). MSX (100 μg/mL) decreased H 2 O 2 -induced oxidative stress (16.1 % decrease in ROS levels compared to control), and down-regulated the production of lipopolysaccharide (LPS)-stimulated inflammatory markers (22.1, 19.9, 74.8, and 87.6 % decrease in NOS, IL-6, PGE 2 , and TNFα levels, respectively, compared to control) in murine BV-2 microglial cells. Moreover, in a non-contact co-culture cell model, differentiated human SH-SY5Y neuronal cells were exposed to conditioned media from BV-2 cells treated with MSX (100 μg/mL) and LPS or LPS alone. MSX-BV-2 media increased SH-SY5Y cell viability by 13.8 % compared to media collected from LPS-BV-2 treated cells. Also, MSX (10 μg/mL) showed protective effects against Aβ 1-42 induced neurotoxicity and paralysis in Caenorhabditis elegans in vivo. These data support the potential neuroprotective effects of MSX warranting further studies on this natural product.

  20. Time Courses of Cortical Glucose Metabolism and Microglial Activity Across the Life Span of Wild-Type Mice: A PET Study.

    Science.gov (United States)

    Brendel, Matthias; Focke, Carola; Blume, Tanja; Peters, Finn; Deussing, Maximilian; Probst, Federico; Jaworska, Anna; Overhoff, Felix; Albert, Nathalie; Lindner, Simon; von Ungern-Sternberg, Barbara; Bartenstein, Peter; Haass, Christian; Kleinberger, Gernot; Herms, Jochen; Rominger, Axel

    2017-12-01

    Contrary to findings in the human brain, 18 F-FDG PET shows cerebral hypermetabolism of aged wild-type (WT) mice relative to younger animals, supposedly due to microglial activation. Therefore, we used dual-tracer small-animal PET to examine directly the link between neuroinflammation and hypermetabolism in aged mice. Methods: WT mice (5-20 mo) were investigated in a cross-sectional design using 18 F-FDG ( n = 43) and translocator protein (TSPO) ( 18 F-GE180; n = 58) small-animal PET, with volume-of-interest and voxelwise analyses. Biochemical analysis of plasma cytokine levels and immunohistochemical confirmation of microglial activity were also performed. Results: Age-dependent cortical hypermetabolism in WT mice relative to young animals aged 5 mo peaked at 14.5 mo (+16%, P mice. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

  1. Early Events in Retinal Degeneration Caused by Rhodopsin Mutation or Pigment Epithelium Malfunction: Differences and Similarities

    Science.gov (United States)

    Di Pierdomenico, Johnny; García-Ayuso, Diego; Pinilla, Isabel; Cuenca, Nicolás; Vidal-Sanz, Manuel; Agudo-Barriuso, Marta; Villegas-Pérez, María P.

    2017-01-01

    To study the course of photoreceptor cell death and macro and microglial reactivity in two rat models of retinal degeneration with different etiologies. Retinas from P23H-1 (rhodopsin mutation) and Royal College of Surgeon (RCS, pigment epithelium malfunction) rats and age-matched control animals (Sprague-Dawley and Pievald Viro Glaxo, respectively) were cross-sectioned at different postnatal ages (from P10 to P60) and rhodopsin, L/M- and S-opsin, ionized calcium-binding adapter molecule 1 (Iba1), glial fibrillary acid protein (GFAP), and proliferating cell nuclear antigen (PCNA) proteins were immunodetected. Photoreceptor nuclei rows and microglial cells in the different retinal layers were quantified. Photoreceptor degeneration starts earlier and progresses quicker in P23H-1 than in RCS rats. In both models, microglial cell activation occurs simultaneously with the initiation of photoreceptor death while GFAP over-expression starts later. As degeneration progresses, the numbers of microglial cells increase in the retina, but decreasing in the inner retina and increasing in the outer retina, more markedly in RCS rats. Interestingly, and in contrast with healthy animals, microglial cells reach the outer nuclei and outer segment layers. The higher number of microglial cells in dystrophic retinas cannot be fully accounted by intraretinal migration and PCNA immunodetection revealed microglial proliferation in both models but more importantly in RCS rats. The etiology of retinal degeneration determines the initiation and pattern of photoreceptor cell death and simultaneously there is microglial activation and migration, while the macroglial response is delayed. The actions of microglial cells in the degeneration cannot be explained only in the basis of photoreceptor death because they participate more actively in the RCS model. Thus, the retinal degeneration caused by pigment epithelium malfunction is more inflammatory and would probably respond better to interventions

  2. Antimycobacterial drug discovery using Mycobacteria-infected amoebae identifies anti-infectives and new molecular targets.

    Science.gov (United States)

    Trofimov, Valentin; Kicka, Sébastien; Mucaria, Sabrina; Hanna, Nabil; Ramon-Olayo, Fernando; Del Peral, Laura Vela-Gonzalez; Lelièvre, Joël; Ballell, Lluís; Scapozza, Leonardo; Besra, Gurdyal S; Cox, Jonathan A G; Soldati, Thierry

    2018-03-02

    Tuberculosis remains a serious threat to human health world-wide, and improved efficiency of medical treatment requires a better understanding of the pathogenesis and the discovery of new drugs. In the present study, we performed a whole-cell based screen in order to complete the characterization of 168 compounds from the GlaxoSmithKline TB-set. We have established and utilized novel previously unexplored host-model systems to characterize the GSK compounds, i.e. the amoeboid organisms D. discoideum and A. castellanii, as well as a microglial phagocytic cell line, BV2. We infected these host cells with Mycobacterium marinum to monitor and characterize the anti-infective activity of the compounds with quantitative fluorescence measurements and high-content microscopy. In summary, 88.1% of the compounds were confirmed as antibiotics against M. marinum, 11.3% and 4.8% displayed strong anti-infective activity in, respectively, the mammalian and protozoan infection models. Additionally, in the two systems, 13-14% of the compounds displayed pro-infective activity. Our studies underline the relevance of using evolutionarily distant pathogen and host models in order to reveal conserved mechanisms of virulence and defence, respectively, which are potential "universal" targets for intervention. Subsequent mechanism of action studies based on generation of over-expresser M. bovis BCG strains, generation of spontaneous resistant mutants and whole genome sequencing revealed four new molecular targets, including FbpA, MurC, MmpL3 and GlpK.

  3. Maternal immune activation results in complex microglial transcriptome signature in the adult offspring that is reversed by minocycline treatment

    NARCIS (Netherlands)

    Mattei, D.; Ivanov, A.; Ferrai, C.; Jordan, P.; Guneykaya, D.; Buonfiglioli, A.; Schaafsma, W.; Przanowski, P.; Deuther-Conrad, W.; Brust, P.; Hesse, S.; Patt, M.; Sabri, O.; Ross, T. L.; Eggen, B. J. L.; Boddeke, E. W. G. M.; Kaminska, B.; Beule, D.; Pombo, A.; Kettenmann, H.; Wolf, S. A.

    2017-01-01

    Maternal immune activation (MIA) during pregnancy has been linked to an increased risk of developing psychiatric pathologies in later life. This link may be bridged by a defective microglial phenotype in the offspring induced by MIA, as microglia have key roles in the development and maintenance of

  4. The microglial NADPH oxidase complex as a source of oxidative stress in Alzheimer's disease

    Directory of Open Access Journals (Sweden)

    Landreth Gary E

    2006-11-01

    Full Text Available Abstract Alzheimer's disease is the most common cause of dementia in the elderly, and manifests as progressive cognitive decline and profound neuronal loss. The principal neuropathological hallmarks of Alzheimer's disease are the senile plaques and the neurofibrillary tangles. The senile plaques are surrounded by activated microglia, which are largely responsible for the proinflammatory environment within the diseased brain. Microglia are the resident innate immune cells in the brain. In response to contact with fibrillar beta-amyloid, microglia secrete a diverse array of proinflammatory molecules. Evidence suggests that oxidative stress emanating from activated microglia contribute to the neuronal loss characteristic of this disease. The source of fibrillar beta-amyloid induced reactive oxygen species is primarily the microglial nicotinamide adenine dinucleotide phosphate (NADPH oxidase. The NADPH oxidase is a multicomponent enzyme complex that, upon activation, produces the highly reactive free radical superoxide. The cascade of intracellular signaling events leading to NADPH oxidase assembly and the subsequent release of superoxide in fibrillar beta-amyloid stimulated microglia has recently been elucidated. The induction of reactive oxygen species, as well as nitric oxide, from activated microglia can enhance the production of more potent free radicals such as peroxynitrite. The formation of peroxynitrite causes protein oxidation, lipid peroxidation and DNA damage, which ultimately lead to neuronal cell death. The elimination of beta-amyloid-induced oxidative damage through the inhibition of the NADPH oxidase represents an attractive therapeutic target for the treatment of Alzheimer's disease.

  5. Carbon-ion radiation enhances migration ability and invasiveness of the pancreatic cancer cell, PANC-1, in vitro.

    Science.gov (United States)

    Fujita, Mayumi; Otsuka, Yoshimi; Imadome, Kaori; Endo, Satoshi; Yamada, Shigeru; Imai, Takashi

    2012-04-01

    Pancreatic cancer is an aggressive disease that responds poorly to conventional photon radiotherapy. Carbon-ion (C-ion) radiation has advantages compared with conventional radiotherapy, because it enables more accurate dose distribution and more efficient tumor cell killing. To elucidate the effects of local radiotherapy on the characteristics of metastatic tumors, it is necessary to understand the nature of motility in irradiated tumor cells; this will, in turn, facilitate the development of effective strategies to counter tumor cell motility, which can be used in combination with radiotherapy. The aim of the present study was to examine the invasiveness of pancreatic cancer cells exposed to C-ion irradiation. We found that C-ion irradiation suppressed the migration of MIAPaCa-2, BxPC-3 and AsPC-1; diminished the invasiveness of MIAPaCa-2; and tended to reduce the invasion of BxPC-3 and AsPC-1. However, C-ion irradiation increased the invasiveness of PANC-1 through the activation of plasmin and urokinase-type plasiminogen activator. Administration of serine protease inhibitor (SerPI) alone failed to reduce C-ion-induced PANC-1 invasiveness, whereas the combination of SerPI and Rho-associated coiled-coil forming protein kinase (ROCK) inhibitor suppressed it. Furthermore, PANC-1 showed mesenchymal-amoeboid transition when we treated with SerPI alone. In conclusion, C-ion irradiation is effective in suppressing the invasive potential of several pancreatic tumor cell lines, but not PANC-1; this is the first study showing that C-ion irradiation induces the invasive potential of a tumor cell line. Further in vivo studies are required to examine the therapeutic effectiveness of radiotherapy combined with inhibitors of both mesenchymal and amoeboid modes of tumor cell motility. © 2011 Japanese Cancer Association.

  6. Polarization of migrating monocytic cells is independent of PI 3-kinase activity.

    Directory of Open Access Journals (Sweden)

    Silvia Volpe

    Full Text Available BACKGROUND: Migration of mammalian cells is a complex cell type and environment specific process. Migrating hematopoietic cells assume a rapid amoeboid like movement when exposed to gradients of chemoattractants. The underlying signaling mechanisms remain controversial with respect to localization and distribution of chemotactic receptors within the plasma membrane and the role of PI 3-kinase activity in cell polarization. METHODOLOGY/PRINCIPAL FINDINGS: We present a novel model for the investigation of human leukocyte migration. Monocytic THP-1 cells transfected with the alpha(2A-adrenoceptor (alpha(2AAR display comparable signal transduction responses, such as calcium mobilization, MAP-kinase activation and chemotaxis, to the noradrenaline homologue UK 14'304 as when stimulated with CCL2, which binds to the endogenous chemokine receptor CCR2. Time-lapse video microscopy reveals that chemotactic receptors remain evenly distributed over the plasma membrane and that their internalization is not required for migration. Measurements of intramolecular fluorescence resonance energy transfer (FRET of alpha(2AAR-YFP/CFP suggest a uniform activation of the receptors over the entire plasma membrane. Nevertheless, PI 3-kinase activation is confined to the leading edge. When reverting the gradient of chemoattractant by moving the dispensing micropipette, polarized monocytes--in contrast to neutrophils--rapidly flip their polarization axis by developing a new leading edge at the previous posterior side. Flipping of the polarization axis is accompanied by re-localization of PI-3-kinase activity to the new leading edge. However, reversal of the polarization axis occurs in the absence of PI 3-kinase activation. CONCLUSIONS/SIGNIFICANCE: Accumulation and internalization of chemotactic receptors at the leading edge is dispensable for cell migration. Furthermore, uniformly distributed receptors allow the cells to rapidly reorient and adapt to changes in the

  7. Effects of Bee Venom on Glutamate-Induced Toxicity in Neuronal and Glial Cells

    Directory of Open Access Journals (Sweden)

    Sang Min Lee

    2012-01-01

    Full Text Available Bee venom (BV, which is extracted from honeybees, is used in traditional Korean medical therapy. Several groups have demonstrated the anti-inflammatory effects of BV in osteoarthritis both in vivo and in vitro. Glutamate is the predominant excitatory neurotransmitter in the central nervous system (CNS. Changes in glutamate release and uptake due to alterations in the activity of glutamate transporters have been reported in many neurodegenerative diseases, including Parkinson's disease, Alzheimer's disease, and amyotrophic lateral sclerosis. To assess if BV can prevent glutamate-mediated neurotoxicity, we examined cell viability and signal transduction in glutamate-treated neuronal and microglial cells in the presence and absence of BV. We induced glutamatergic toxicity in neuronal cells and microglial cells and found that BV protected against cell death. Furthermore, BV significantly inhibited the cellular toxicity of glutamate, and pretreatment with BV altered MAP kinase activation (e.g., JNK, ERK, and p38 following exposure to glutamate. These findings suggest that treatment with BV may be helpful in reducing glutamatergic cell toxicity in neurodegenerative diseases.

  8. Effects of caffeine on DNA repair of UV-irradiated Dictyostelium discoideum

    International Nuclear Information System (INIS)

    Ohnishi, T.; Okaichi, K.; Ohashi, Y.; Nozu, K.

    1981-01-01

    Caffeine enhances the UV-killing of amoeboid cells of NC-4, but UV-irradiated γs-13 is insensitive to caffeine. UV-irradiated NC-4 becomes insensitive to the effect of caffeine during a postirradiation incubation in buffer for about 90 min, but γs-13 remains unchanged in the sensitivity to caffeine throughout the incubation for 180 min. Amoeboid cells of γs-13 can remove pyrimidine dimers as well as NC-4 even in the presence of caffeine. Caffeine inhibits rejoining of strand-breaks of DNA in UV-irradiated NC-4, but the rejoining in γs-13 is insensitive to caffeine. (author)

  9. High content analysis of phagocytic activity and cell morphology with PuntoMorph.

    Science.gov (United States)

    Al-Ali, Hassan; Gao, Han; Dalby-Hansen, Camilla; Peters, Vanessa Ann; Shi, Yan; Brambilla, Roberta

    2017-11-01

    Phagocytosis is essential for maintenance of normal homeostasis and healthy tissue. As such, it is a therapeutic target for a wide range of clinical applications. The development of phenotypic screens targeting phagocytosis has lagged behind, however, due to the difficulties associated with image-based quantification of phagocytic activity. We present a robust algorithm and cell-based assay system for high content analysis of phagocytic activity. The method utilizes fluorescently labeled beads as a phagocytic substrate with defined physical properties. The algorithm employs statistical modeling to determine the mean fluorescence of individual beads within each image, and uses the information to conduct an accurate count of phagocytosed beads. In addition, the algorithm conducts detailed and sophisticated analysis of cellular morphology, making it a standalone tool for high content screening. We tested our assay system using microglial cultures. Our results recapitulated previous findings on the effects of microglial stimulation on cell morphology and phagocytic activity. Moreover, our cell-level analysis revealed that the two phenotypes associated with microglial activation, specifically cell body hypertrophy and increased phagocytic activity, are not highly correlated. This novel finding suggests the two phenotypes may be under the control of distinct signaling pathways. We demonstrate that our assay system outperforms preexisting methods for quantifying phagocytic activity in multiple dimensions including speed, accuracy, and resolution. We provide a framework to facilitate the development of high content assays suitable for drug screening. For convenience, we implemented our algorithm in a standalone software package, PuntoMorph. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Omega-3 polyunsaturated fatty acid supplementation attenuates microglial-induced inflammation by inhibiting the HMGB1/TLR4/NF-κB pathway following experimental traumatic brain injury.

    Science.gov (United States)

    Chen, Xiangrong; Wu, Shukai; Chen, Chunnuan; Xie, Baoyuan; Fang, Zhongning; Hu, Weipeng; Chen, Junyan; Fu, Huangde; He, Hefan

    2017-07-24

    Microglial activation and the subsequent inflammatory response in the central nervous system play important roles in secondary damage after traumatic brain injury (TBI). High-mobility group box 1 (HMGB1) protein, an important mediator in late inflammatory responses, interacts with transmembrane receptor for advanced glycation end products (RAGE) and toll-like receptors (TLRs) to activate downstream signaling pathways, such as the nuclear factor (NF)-κB signaling pathway, leading to a cascade amplification of inflammatory responses, which are related to neuronal damage after TBI. Omega-3 polyunsaturated fatty acid (ω-3 PUFA) is a commonly used clinical immunonutrient, which has antioxidative and anti-inflammatory effects. However, the effects of ω-3 PUFA on HMGB1 expression and HMGB1-mediated activation of the TLR4/NF-κB signaling pathway are not clear. The Feeney DM TBI model was adopted to induce brain injury in rats. Modified neurological severity scores, brain water content, and Nissl staining were employed to determine the neuroprotective effects of ω-3 PUFA supplementation. Assessment of microglial activation in lesioned sites and protein markers for proinflammatory, such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, interferon (IFN)-γ, and HMGB1 were used to evaluate neuroinflammatory responses and anti-inflammation effects of ω-3 PUFA supplementation. Immunofluorescent staining and western blot analysis were used to detect HMGB1 nuclear translocation, secretion, and HMGB1-mediated activation of the TLR4/NF-κB signaling pathway to evaluate the effects of ω-3 PUFA supplementation and gain further insight into the mechanisms underlying the development of the neuroinflammatory response after TBI. It was found that ω-3 PUFA supplementation inhibited TBI-induced microglial activation and expression of inflammatory factors (TNF-α, IL-1β, IL-6, and IFN-γ), reduced brain edema, decreased neuronal apoptosis, and improved neurological

  11. Synergistic Effects of Psychosocial Stress and Mild Peripheral Infection on Inducing Microglial Activation in the Hippocampal Dentate Gyrus and Long-Lasting Deficits in Hippocampus-Related Memory.

    Science.gov (United States)

    Tzeng, Wen-Yu; Su, Chien-Chou; Sun, Li-Han; Cherng, Chianfang G.; Yu, Lung

    2018-04-30

    Lipopolysaccharide (LPS) treatment and stress may cause immune activation in the brain, an event which has been thought to play a role in mediating stress-induced cognitive dysfunction. However, the enduring impact of psychosocial stress on brain immune activation or cognitive deficits has not been well investigated. Likewise, it remains unexplored whether there exist synergistic effects of psychosocial stress and a weak systemic LPS treatment on brain immune activation and/or cognitive function. In this work, a 10-day social defeat regimen was used to model psychosocial stress and the number and density of ionized calcium-binding adaptor molecule 1 (Iba1)-stained microglia was used to reveal brain immune activation in male Balb/C mice. The social defeat regimen did not cause observable microglial activation in dentate gyrus (DG) 24 h after the conclusion of the regimen. Microglial activation peaked in DG 24 h following a single 1 mg/kg intra-peritoneal LPS injection. At this time point, DG microglial activation was not evident providing 0.125 mg/kg or lower of LPS was used, this dose of LPS was, thus, regarded as the “sub-threshold” in this study. Twenty-four h after the conclusion of the defeat regimen, mice received a social interaction test to determine their defeat stress susceptibility and a “sub-threshold” LPS injection. DG microglial activation was observed in the defeat-stress susceptible, but not in the resilient, mice. Furthermore, the stress-susceptible mice showed impairment in object location and Y maze tasks 24 and 72 h after the “sub-threshold” LPS injection. These results suggest that psychosocial stress, when combined with a negligible peripheral infection, may induce long-lasting hippocampus-related memory deficits exclusively in subjects susceptible to psychosocial stresses.

  12. An oscillating dynamic model of collective cells in a monolayer

    Science.gov (United States)

    Lin, Shao-Zhen; Xue, Shi-Lei; Li, Bo; Feng, Xi-Qiao

    2018-03-01

    Periodic oscillations of collective cells occur in the morphogenesis and organogenesis of various tissues and organs. In this paper, an oscillating cytodynamic model is presented by integrating the chemomechanical interplay between the RhoA effector signaling pathway and cell deformation. We show that both an isolated cell and a cell aggregate can undergo spontaneous oscillations as a result of Hopf bifurcation, upon which the system evolves into a limit cycle of chemomechanical oscillations. The dynamic characteristics are tailored by the mechanical properties of cells (e.g., elasticity, contractility, and intercellular tension) and the chemical reactions involved in the RhoA effector signaling pathway. External forces are found to modulate the oscillation intensity of collective cells in the monolayer and to polarize their oscillations along the direction of external tension. The proposed cytodynamic model can recapitulate the prominent features of cell oscillations observed in a variety of experiments, including both isolated cells (e.g., spreading mouse embryonic fibroblasts, migrating amoeboid cells, and suspending 3T3 fibroblasts) and multicellular systems (e.g., Drosophila embryogenesis and oogenesis).

  13. From Individual to Collective Behavior of Unicellular Organisms: Recent Results and Open Problems

    KAUST Repository

    Xue, Chuan

    2009-09-23

    The collective movements of unicellular organisms such as bacteria or amoeboid (crawling) cells are often modeled by partial differential equations (PDEs) that describe the time evolution of cell density. In particular, chemotaxis equations have been used to model the movement towards various kinds of extracellular cues. Well‐developed analytical and numerical methods for analyzing the time‐dependent and time‐independent properties of solutions make this approach attractive. However, these models are often based on phenomenological descriptions of cell fluxes with no direct correspondence to individual cell processes such signal transduction and cell movement. This leads to the question of how to justify these macroscopic PDEs from microscopic descriptions of cells, and how to relate the macroscopic quantities in these PDEs to individual‐level parameters. Here we summarize recent progress on this question in the context of bacterial and amoeboid chemotaxis, and formulate several open problems.

  14. From Individual to Collective Behavior of Unicellular Organisms: Recent Results and Open Problems

    KAUST Repository

    Xue, Chuan; Othmer, Hans G.; Erban, Radek

    2009-01-01

    The collective movements of unicellular organisms such as bacteria or amoeboid (crawling) cells are often modeled by partial differential equations (PDEs) that describe the time evolution of cell density. In particular, chemotaxis equations have been used to model the movement towards various kinds of extracellular cues. Well‐developed analytical and numerical methods for analyzing the time‐dependent and time‐independent properties of solutions make this approach attractive. However, these models are often based on phenomenological descriptions of cell fluxes with no direct correspondence to individual cell processes such signal transduction and cell movement. This leads to the question of how to justify these macroscopic PDEs from microscopic descriptions of cells, and how to relate the macroscopic quantities in these PDEs to individual‐level parameters. Here we summarize recent progress on this question in the context of bacterial and amoeboid chemotaxis, and formulate several open problems.

  15. Dopamine receptor D3 expressed on CD4+ T cells favors neurodegeneration of dopaminergic neurons during Parkinson's disease.

    Science.gov (United States)

    González, Hugo; Contreras, Francisco; Prado, Carolina; Elgueta, Daniela; Franz, Dafne; Bernales, Sebastián; Pacheco, Rodrigo

    2013-05-15

    Emerging evidence has demonstrated that CD4(+) T cells infiltrate into the substantia nigra (SN) in Parkinson's disease (PD) patients and in animal models of PD. SN-infiltrated CD4(+) T cells bearing inflammatory phenotypes promote microglial activation and strongly contribute to neurodegeneration of dopaminergic neurons. Importantly, altered expression of dopamine receptor D3 (D3R) in PBLs from PD patients has been correlated with disease severity. Moreover, pharmacological evidence has suggested that D3R is involved in IFN-γ production by human CD4(+) T cells. In this study, we examined the role of D3R expressed on CD4(+) T cells in neurodegeneration of dopaminergic neurons in the SN using a mouse model of PD. Our results show that D3R-deficient mice are strongly protected against loss of dopaminergic neurons and microglial activation during 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD. Notably, D3R-deficient mice become susceptible to MPTP-induced neurodegeneration and microglial activation upon transfer of wild-type (WT) CD4(+) T cells. Furthermore, RAG1 knockout mice, which are devoid of T cells and are resistant to MPTP-induced neurodegeneration, become susceptible to MPTP-induced loss of dopaminergic neurons when reconstituted with WT CD4(+) T cells but not when transferred with D3R-deficient CD4(+) T cells. In agreement, experiments analyzing activation and differentiation of CD4(+) T cells revealed that D3R favors both T cell activation and acquisition of the Th1 inflammatory phenotype. These findings indicate that D3R expressed on CD4(+) T cells plays a fundamental role in the physiopathology of MPTP-induced PD in a mouse model.

  16. The Role of MAC1 in Diesel Exhaust Particle-induced Microglial Activation and Loss of Dopaminergic Neuron Function

    OpenAIRE

    Levesque, Shannon; Taetzsch, Thomas; Lull, Melinda E.; Johnson, Jo Anne; McGraw, Constance; Block, Michelle L.

    2013-01-01

    Increasing reports support that air pollution causes neuroinflammation and is linked to central nervous system (CNS) disease/damage. Diesel exhaust particles (DEP) are a major component of urban air pollution, which has been linked to microglial activation and Parkinson’s disease-like pathology. To begin to address how DEP may exert CNS effects, microglia and neuron-glia cultures were treated with either nanometer-sized DEP (

  17. Glatiramer Acetate administration does not reduce damage after cerebral ischemia in mice.

    Science.gov (United States)

    Poittevin, Marine; Deroide, Nicolas; Azibani, Feriel; Delcayre, Claude; Giannesini, Claire; Levy, Bernard I; Pocard, Marc; Kubis, Nathalie

    2013-01-15

    Inflammation plays a key role in ischemic stroke pathophysiology: microglial/macrophage cells and type-1 helper cells (Th1) seem deleterious, while type-2 helper cells (Th2) and regulatory T cells (Treg) seem protective. CD4 Th0 differentiation is modulated by microglial cytokine secretion. Glatiramer Acetate (GA) is an immunomodulatory drug that has been approved for the treatment of human multiple sclerosis by means of a number of mechanisms: reduced microglial activation and pro-inflammatory cytokine production, Th0 differentiation shifting from Th2 to Th2 and Treg with anti-inflammatory cytokine production and increased neurogenesis. We induced permanent (pMCAo) or transient middle cerebral artery occlusion (tMCAo) and GA (2 mg) or vehicle was injected subcutaneously immediately after cerebral ischemia. Mice were sacrificed at D3 to measure neurological deficit, infarct volume, microglial cell density and qPCR of TNFα and IL-1β (pro-inflammatory microglial cytokines), IFNγ (Th2 cytokine), IL-4 (Th2 cytokine), TGFβ and IL-10 (Treg cytokines), and at D7 to evaluate neurological deficit, infarct volume and neurogenesis assessment. We showed that in GA-treated pMCAo mice, infarct volume, microglial cell density and cytokine secretion were not significantly modified at D3, while neurogenesis was enhanced at D7 without significant infarct volume reduction. In GA-treated tMCAo mice, microglial pro-inflammatory cytokines IL-1β and TNFα were significantly decreased without modification of microglial/macrophage cell density, cytokine secretion, neurological deficit or infarct volume at D3, or modification of neurological deficit, neurogenesis or infarct volume at D7. In conclusion, Glatiramer Acetate administered after cerebral ischemia does not reduce infarct volume or improve neurological deficit in mice despite a significant increase in neurogenesis in pMCAo and a microglial pro-inflammatory cytokine reduction in tMCAo. Copyright © 2012 Elsevier B.V. All rights

  18. Bidirectional Microglia-Neuron Communication in the Healthy Brain

    Directory of Open Access Journals (Sweden)

    Ukpong B. Eyo

    2013-01-01

    Full Text Available Unlike other resident neural cells that are of neuroectodermal origin, microglia are resident neural cells of mesodermal origin. Traditionally recognized for their immune functions during disease, new roles are being attributed to these cells in the development and maintenance of the central nervous system (CNS including specific communication with neurons. In this review, we highlight some of the recent findings on the bidirectional interaction between neurons and microglia. We discuss these interactions along two lines. First, we review data that suggest that microglial activity is modulated by neuronal signals, focusing on evidence that (i neurons are capable of regulating microglial activation state and influence basal microglial activities; (ii classic neurotransmitters affect microglial behavior; (iii chemotactic signals attract microglia during acute neuronal injury. Next, we discuss some of the recent data on how microglia signal to neurons. Signaling mechanisms include (i direct physical contact of microglial processes with neuronal elements; (ii microglial regulation of neuronal synapse and circuit by fractalkine, complement, and DAP12 signaling. In addition, we discuss the use of microglial depletion strategies in studying the role of microglia in neuronal development and synaptic physiology. Deciphering the mechanisms of bidirectional microglial-neuronal communication provides novel insights in understanding microglial function in both the healthy and diseased brain.

  19. Docosahexaenoic acid accumulation in hraustochytrids: Search for the rationale

    Digital Repository Service at National Institute of Oceanography (India)

    Jain, R.; Raghukumar, S.; Sambaiah, K.; Kumon, Y.; Nakahara, T.

    development was studied by staining lipids of vegetative cells with the fluorescent vital stain for lipids, namely Nile blue, following the growth of the cells. The fluorescent lipid bodies decreased in abundance in freshly formed motile limaciform amoeboid...

  20. Glial cell morphological and density changes through the lifespan of rhesus macaques.

    Science.gov (United States)

    Robillard, Katelyn N; Lee, Kim M; Chiu, Kevin B; MacLean, Andrew G

    2016-07-01

    How aging impacts the central nervous system (CNS) is an area of intense interest. Glial morphology is known to affect neuronal and immune function as well as metabolic and homeostatic balance. Activation of glia, both astrocytes and microglia, occurs at several stages during development and aging. The present study analyzed changes in glial morphology and density through the entire lifespan of rhesus macaques, which are physiologically and anatomically similar to humans. We observed apparent increases in gray matter astrocytic process length and process complexity as rhesus macaques matured from juveniles through adulthood. These changes were not attributed to cell enlargement because they were not accompanied by proportional changes in soma or process volume. There was a decrease in white matter microglial process length as rhesus macaques aged. Aging was shown to have a significant effect on gray matter microglial density, with a significant increase in aged macaques compared with adults. Overall, we observed significant changes in glial morphology as macaques age indicative of astrocytic activation with subsequent increase in microglial density in aged macaques. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Deficiency of leptin receptor in myeloid cells disrupts hypothalamic metabolic circuits and causes body weight increase

    Directory of Open Access Journals (Sweden)

    Yuanqing Gao

    2018-01-01

    Conclusions: Myeloid cell leptin receptor deficient mice partially replicate the db/db phenotype. Leptin signaling in hypothalamic microglia is important for microglial function and a correct formation of the hypothalamic neuronal circuit regulating metabolism.

  2. Inhibitory Effects of Ketamine on Lipopolysaccharide-Induced Microglial Activation

    Directory of Open Access Journals (Sweden)

    Yi Chang

    2009-01-01

    Full Text Available Microglia activated in response to brain injury release neurotoxic factors including nitric oxide (NO and proinflammatory cytokines such as tumor necrosis factor-α (TNF-α and interleukin-1β (IL-1β. Ketamine, an anesthetic induction agent, is generally reserved for use in patients with severe hypotension or respiratory depression. In this study, we found that ketamine (100 and 250 μM concentration-dependently inhibited lipopolysaccharide (LPS-induced NO and IL-1β release in primary cultured microglia. However, ketamine (100 and 250 μM did not significantly inhibit the LPS-induced TNF-α production in microglia, except at the higher concentration (500 μM. Further study of the molecular mechanisms revealed that ketamine markedly inhibited extracellular signal-regulated kinase (ERK1/2 phosphorylation but not c-Jun N-terminal kinase or p38 mitogen-activated protein kinase stimulated by LPS in microglia. These results suggest that microglial inactivation by ketamine is at least partially due to inhibition of ERK1/2 phosphorylation.

  3. Protection against RAGE-mediated neuronal cell death by sRAGE-secreting human mesenchymal stem cells in 5xFAD transgenic mouse model.

    Science.gov (United States)

    Son, Myeongjoo; Oh, Seyeon; Park, Hyunjin; Ahn, Hyosang; Choi, Junwon; Kim, Hyungho; Lee, Hye Sun; Lee, Sojung; Park, Hye-Jeong; Kim, Seung U; Lee, Bonghee; Byun, Kyunghee

    2017-11-01

    Alzheimer's disease (AD), which is the most commonly encountered neurodegenerative disease, causes synaptic dysfunction and neuronal loss due to various pathological processes that include tau abnormality and amyloid beta (Aβ) accumulation. Aβ stimulates the secretion and the synthesis of Receptor for Advanced Glycation End products (RAGE) ligand by activating microglial cells, and has been reported to cause neuronal cell death in Aβ 1-42 treated rats and in mice with neurotoxin-induced Parkinson's disease. The soluble form of RAGE (sRAGE) is known to reduce inflammation, and to decrease microglial cell activation and Aβ deposition, and thus, it protects from neuronal cell death in AD. However, sRAGE protein has too a short half-life for therapeutic purposes. We developed sRAGE-secreting umbilical cord derived mesenchymal stem cells (sRAGE-MSCs) to enhance the inhibitory effects of sRAGE on Aβ deposition and to reduce the secretion and synthesis of RAGE ligands in 5xFAD mice. In addition, these cells improved the viability of injected MSCs, and enhanced the protective effects of sRAGE by inhibiting the binding of RAGE and RAGE ligands in 5xFAD mice. These findings suggest sRAGE protein from sRAGE-MSCs has better protection against neuronal cell death than sRAGE protein or single MSC treatment by inhibiting the RAGE cell death cascade and RAGE-induce inflammation. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Age-related memory decline is associated with vascular and microglial degeneration in aged rats.

    Science.gov (United States)

    Zhang, Rong; Kadar, Tamar; Sirimanne, Ernest; MacGibbon, Alastair; Guan, Jian

    2012-12-01

    The hippocampus processes memory is an early target of aging-related biological and structural lesions, leading to memory decline. With absent neurodegeneration in the hippocampus, which identified in rodent model of normal aging the pathology underlying age-related memory impairment is not complete. The effective glial-vascular networks are the key for maintaining neuronal functions. The changes of glial cells and cerebral capillaries with age may contribute to memory decline. Thus we examined age associated changes in neurons, glial phenotypes and microvasculature in the hippocampus of aged rats with memory decline. Young adult (6 months) and aged (35 months) male rats (Fisher/Norway-Brown) were used. To evaluate memory, four days of acquisition phase of Morris water maze tasks were carried out in both age groups and followed by a probe trial 2 h after the acquisition. The brains were then collected for analysis using immunochemistry. The aged rats showed a delayed latency (pvascular and microglial degeneration with reduced vascular endothelial growth factor and elevated GFAP expression in the hippocampus. The data indicate the memory decline with age is associated with neuronal dysfunction, possibly due to impaired glial-vascular-neuronal networks, but not neuronal degeneration. Glial and vascular degeneration found in aged rats may represent early event of aging pathology prior to neuronal degeneration. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Activation of Microglial Cells: the Bridge between the Immune System and Pain in Central Nervous System

    Directory of Open Access Journals (Sweden)

    Ali Dabbagh

    2016-08-01

    Full Text Available Background: Pain is one of the main protests of inflammatory diseases, hence, understanding the mechanisms which involved in the induction and persistence of pain is essential. Microglia is a contributing factor in the onset and maintenance of inflammation. Increased microglial   activation increases the level of central pro-inflammatory cytokines and the development of central sensitization following inflammation. The aim of this study was evaluate the relation of spinal microglia activity with pain related behaviors during Complete Freund’s adjuvant (CFA-induced inflammation.Materials and Methods: Inflammation caused by subcutaneous injection of Complete Freund’s adjuvant (CFA in a single dose to the animals right hind paw. The edema and hyperalgesia caused by inflammation, respectively are measured by Plethysmometer and Radiant Heat, on days 0,7,14 and 21. Spinal Iba-1 protein expression was detected by Western blotting. Minocycline hydrochloride (Sigma, U.S.A was administered i.p. at a dose of 40mg/kg daily.Results: Our study findings indicated that CFA injection to right hindpaw of rats increased paw volume and hyperalgesia significantly during different stages of study, while Minocycline treatment significantly reduced paw volume and hyperalgesia. CFA injection into the right hindpaw of the rat increases the expression of molecules Ionized calcium binding adaptor molecule -1 (Iba-1 on different days of study, while Minocycline administration reduced spinal Iba-1 expression significantly compared to the CFA group.Conclusion: The results of this study indicated the significant roles of microglia activation in deterioration of pain related behaviors during different stages of CFA-induced inflammation. The steady injection of Minocycline (as a microglia inhibitor could reduce the inflammatory symptoms.

  6. Microglia and neuroprotection: implications for Alzheimer's disease.

    Science.gov (United States)

    Streit, Wolfgang J

    2005-04-01

    The first part of this paper summarizes some of the key observations from experimental work in animals that support a role of microglia as neuroprotective cells after acute neuronal injury. These studies point towards an important role of neuronal-microglial crosstalk in the facilitation of neuroprotection. Conceptually, injured neurons are thought to generate rescue signals that trigger microglial activation and, in turn, activated microglia produce trophic or other factors that help damaged neurons recover from injury. Against this background, the second part of this paper summarizes recent work from postmortem studies conducted in humans that have revealed the occurrence of senescent, or dystrophic, microglial cells in the aged and Alzheimer's disease brain. These findings suggest that microglial cells become increasingly dysfunctional with advancing age and that a loss of microglial cell function may involve a loss of neuroprotective properties that could contribute to the development of aging-related neurodegeneration.

  7. Cell shape dynamics: from waves to migration.

    Directory of Open Access Journals (Sweden)

    Meghan K Driscoll

    Full Text Available We observe and quantify wave-like characteristics of amoeboid migration. Using the amoeba Dictyostelium discoideum, a model system for the study of chemotaxis, we demonstrate that cell shape changes in a wave-like manner. Cells have regions of high boundary curvature that propagate from the leading edge toward the back, usually along alternating sides of the cell. Curvature waves are easily seen in cells that do not adhere to a surface, such as cells that are electrostatically repelled from surfaces or cells that extend over the edge of micro-fabricated cliffs. Without surface contact, curvature waves travel from the leading edge to the back of a cell at -35 µm/min. Non-adherent myosin II null cells do not exhibit these curvature waves. At the leading edge of adherent cells, curvature waves are associated with protrusive activity. Like regions of high curvature, protrusive activity travels along the boundary in a wave-like manner. Upon contact with a surface, the protrusions stop moving relative to the surface, and the boundary shape thus reflects the history of protrusive motion. The wave-like character of protrusions provides a plausible mechanism for the zig-zagging of pseudopods and for the ability of cells both to swim in viscous fluids and to navigate complex three dimensional topography.

  8. Toll-like receptor 4 mediates microglial activation and production of inflammatory mediators in neonatal rat brain following hypoxia: role of TLR4 in hypoxic microglia

    Science.gov (United States)

    2013-01-01

    Background Hypoxia induces microglial activation which causes damage to the developing brain. Microglia derived inflammatory mediators may contribute to this process. Toll-like receptor 4 (TLR4) has been reported to induce microglial activation and cytokines production in brain injuries; however, its role in hypoxic injury remains uncertain. We investigate here TLR4 expression and its roles in neuroinflammation in neonatal rats following hypoxic injury. Methods One day old Wistar rats were subjected to hypoxia for 2 h. Primary cultured microglia and BV-2 cells were subjected to hypoxia for different durations. TLR4 expression in microglia was determined by RT-PCR, western blot and immunofluorescence staining. Small interfering RNA (siRNA) transfection and antibody neutralization were employed to downregulate TLR4 in BV-2 and primary culture. mRNA and protein expression of tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β) and inducible nitric oxide synthase (iNOS) was assessed. Reactive oxygen species (ROS), nitric oxide (NO) and NF-κB levels were determined by flow cytometry, colorimetric and ELISA assays respectively. Hypoxia-inducible factor-1 alpha (HIF-1α) mRNA and protein expression was quantified and where necessary, the protein expression was depleted by antibody neutralization. In vivo inhibition of TLR4 with CLI-095 injection was carried out followed by investigation of inflammatory mediators expression via double immunofluorescence staining. Results TLR4 immunofluorescence and protein expression in the corpus callosum and cerebellum in neonatal microglia were markedly enhanced post-hypoxia. In vitro, TLR4 protein expression was significantly increased in both primary microglia and BV-2 cells post-hypoxia. TLR4 neutralization in primary cultured microglia attenuated the hypoxia-induced expression of TNF-α, IL-1β and iNOS. siRNA knockdown of TLR4 reduced hypoxia-induced upregulation of TNF-α, IL-1β, iNOS, ROS and NO in BV-2 cells. TLR4

  9. The perivascular phagocyte of the mouse pineal gland: An antigen-presenting cell

    DEFF Research Database (Denmark)

    Møller, Morten; Rath, Martin F; Klein, David C

    2006-01-01

    The perivascular space of the rat pineal gland is known to contain phagocytic cells that are immunoreactive for leukocyte antigens, and thus they appear to belong to the macrophage/microglial cell line. These cells also contain MHC class II proteins. We investigated this cell type in the pineal g...... for MHC class II protein and for CD68, a marker of monocytes/phagocytes. This study verifies that perivascular phagocytes with antigen-presenting properties are present in the mouse pineal gland....

  10. Rod-like microglia are restricted to eyes with laser-induced ocular hypertension but absent from the microglial changes in the contralateral untreated eye.

    Directory of Open Access Journals (Sweden)

    Rosa de Hoz

    Full Text Available In the mouse model of unilateral laser-induced ocular hypertension (OHT the microglia in both the treated and the normotensive untreated contralateral eye have morphological signs of activation and up-regulation of MHC-II expression in comparison with naïve. In the brain, rod-like microglia align to less-injured neurons in an effort to limit damage. We investigate whether: i microglial activation is secondary to laser injury or to a higher IOP and; ii the presence of rod-like microglia is related to OHT. Three groups of mice were used: age-matched control (naïve, n=15; and two lasered: limbal (OHT, n=15; and non-draining portion of the sclera (scleral, n=3. In the lasered animals, treated eyes as well as contralateral eyes were analysed. Retinal whole-mounts were immunostained with antibodies against, Iba-1, NF-200, MHC-II, CD86, CD68 and Ym1. In the scleral group (normal ocular pressure no microglial signs of activation were found. Similarly to naïve eyes, OHT-eyes and their contralateral eyes had ramified microglia in the nerve-fibre layer related to the blood vessel. However, only eyes with OHT had rod-like microglia that aligned end-to-end, coupling to form trains of multiple cells running parallel to axons in the retinal surface. Rod-like microglia were CD68+ and were related to retinal ganglion cells (RGCs showing signs of degeneration (NF-200+RGCs. Although MHC-II expression was up-regulated in the microglia of the NFL both in OHT-eyes and their contralateral eyes, no expression of CD86 and Ym1 was detected in ramified or in rod-like microglia. After 15 days of unilateral lasering of the limbal and the non-draining portion of the sclera, activated microglia was restricted to OHT-eyes and their contralateral eyes. However, rod-like microglia were restricted to eyes with OHT and degenerated NF-200+RGCs and were absent from their contralateral eyes. Thus, rod-like microglia seem be related to the neurodegeneration associated with HTO.

  11. Preventive effects of a fermented dairy product against Alzheimer's disease and identification of a novel oleamide with enhanced microglial phagocytosis and anti-inflammatory activity.

    Directory of Open Access Journals (Sweden)

    Yasuhisa Ano

    Full Text Available Despite the ever-increasing number of patients with dementia worldwide, fundamental therapeutic approaches to this condition have not been established. Epidemiological studies suggest that intake of fermented dairy products prevents cognitive decline in the elderly. However, the active compounds responsible for the effect remain to be elucidated. The present study aims to elucidate the preventive effects of dairy products on Alzheimer's disease and to identify the responsible component. Here, in a mouse model of Alzheimer's disease (5xFAD, intake of a dairy product fermented with Penicillium candidum had preventive effects on the disease by reducing the accumulation of amyloid β (Aβ and hippocampal inflammation (TNF-α and MIP-1α production, and enhancing hippocampal neurotrophic factors (BDNF and GDNF. A search for preventive substances in the fermented dairy product identified oleamide as a novel dual-active component that enhanced microglial Aβ phagocytosis and anti-inflammatory activity towards LPS stimulation in vitro and in vivo. During the fermentation, oleamide was synthesized from oleic acid, which is an abundant component of general dairy products owing to lipase enzymatic amidation. The present study has demonstrated the preventive effect of dairy products on Alzheimer's disease, which was previously reported only epidemiologically. Moreover, oleamide has been identified as an active component of dairy products that is considered to reduce Aβ accumulation via enhanced microglial phagocytosis, and to suppress microglial inflammation after Aβ deposition. Because fermented dairy products such as camembert cheese are easy to ingest safely as a daily meal, their consumption might represent a preventive strategy for dementia.

  12. Preventive effects of a fermented dairy product against Alzheimer's disease and identification of a novel oleamide with enhanced microglial phagocytosis and anti-inflammatory activity.

    Science.gov (United States)

    Ano, Yasuhisa; Ozawa, Makiko; Kutsukake, Toshiko; Sugiyama, Shinya; Uchida, Kazuyuki; Yoshida, Aruto; Nakayama, Hiroyuki

    2015-01-01

    Despite the ever-increasing number of patients with dementia worldwide, fundamental therapeutic approaches to this condition have not been established. Epidemiological studies suggest that intake of fermented dairy products prevents cognitive decline in the elderly. However, the active compounds responsible for the effect remain to be elucidated. The present study aims to elucidate the preventive effects of dairy products on Alzheimer's disease and to identify the responsible component. Here, in a mouse model of Alzheimer's disease (5xFAD), intake of a dairy product fermented with Penicillium candidum had preventive effects on the disease by reducing the accumulation of amyloid β (Aβ) and hippocampal inflammation (TNF-α and MIP-1α production), and enhancing hippocampal neurotrophic factors (BDNF and GDNF). A search for preventive substances in the fermented dairy product identified oleamide as a novel dual-active component that enhanced microglial Aβ phagocytosis and anti-inflammatory activity towards LPS stimulation in vitro and in vivo. During the fermentation, oleamide was synthesized from oleic acid, which is an abundant component of general dairy products owing to lipase enzymatic amidation. The present study has demonstrated the preventive effect of dairy products on Alzheimer's disease, which was previously reported only epidemiologically. Moreover, oleamide has been identified as an active component of dairy products that is considered to reduce Aβ accumulation via enhanced microglial phagocytosis, and to suppress microglial inflammation after Aβ deposition. Because fermented dairy products such as camembert cheese are easy to ingest safely as a daily meal, their consumption might represent a preventive strategy for dementia.

  13. Temporomandibular joint inflammation activates glial and immune cells in both the trigeminal ganglia and in the spinal trigeminal nucleus

    Directory of Open Access Journals (Sweden)

    Jasmin Luc

    2010-12-01

    Full Text Available Abstract Background Glial cells have been shown to directly participate to the genesis and maintenance of chronic pain in both the sensory ganglia and the central nervous system (CNS. Indeed, glial cell activation has been reported in both the dorsal root ganglia and the spinal cord following injury or inflammation of the sciatic nerve, but no data are currently available in animal models of trigeminal sensitization. Therefore, in the present study, we evaluated glial cell activation in the trigeminal-spinal system following injection of the Complete Freund's Adjuvant (CFA into the temporomandibular joint, which generates inflammatory pain and trigeminal hypersensitivity. Results CFA-injected animals showed ipsilateral mechanical allodynia and temporomandibular joint edema, accompanied in the trigeminal ganglion by a strong increase in the number of GFAP-positive satellite glial cells encircling neurons and by the activation of resident macrophages. Seventy-two hours after CFA injection, activated microglial cells were observed in the ipsilateral trigeminal subnucleus caudalis and in the cervical dorsal horn, with a significant up-regulation of Iba1 immunoreactivity, but no signs of reactive astrogliosis were detected in the same areas. Since the purinergic system has been implicated in the activation of microglial cells during neuropathic pain, we have also evaluated the expression of the microglial-specific P2Y12 receptor subtype. No upregulation of this receptor was detected following induction of TMJ inflammation, suggesting that any possible role of P2Y12 in this paradigm of inflammatory pain does not involve changes in receptor expression. Conclusions Our data indicate that specific glial cell populations become activated in both the trigeminal ganglia and the CNS following induction of temporomandibular joint inflammation, and suggest that they might represent innovative targets for controlling pain during trigeminal nerve sensitization.

  14. The organotin compounds trimethyltin (TMT) and triethyltin (TET) but not tributyltin (TBT) induce activation of microglia co-cultivated with astrocytes.

    Science.gov (United States)

    Röhl, C; Grell, M; Maser, E

    2009-12-01

    The organotin compounds trimethyltin (TMT), triethyltin (TET) and tributyltin (TBT) show different organotoxicities in vivo. While TMT and TET induce a strong neurotoxicity accompanied by microglial and astroglial activation, TBT rather effects the immune system. Previously, we have shown in an in vitro co-culture model that microglial cells can be activated by TMT in the presence of astrocytes. In this study, we wanted to investigate (a) if the neurotoxic organotin compound TET can also activate microglial cells in vitro similar to TMT and (b) if differences between the neurotoxicants TMT and TET on the one side and TBT on the other exist concerning microglial activation. Therefore, purified microglial and astroglial cell cultures from neonatal rat brains were treated either alone or in co-cultures for 24h with different concentrations of TMT, TET or TBT and the basal cytotoxicity and nitric oxide formation was determined. Furthermore, morphological changes of astrocytes were examined. Our results show that microglial activation can be increased in subcytolethal concentrations, but only in the presence of astrocytes and not in microglial cell cultures alone. This increase was induced by the neurotoxicants TMT and TET but not by TBT. Taken together, the differing microglia activating effect of the organotin compounds may contribute to the differing neurotoxic potential of this group of chemicals in vivo. In addition, our results emphasize the need for co-culture systems when studying interactions between different cell types for toxicity assessment.

  15. The NALP3 inflammasome is involved in neurotoxic prion peptide-induced microglial activation

    Directory of Open Access Journals (Sweden)

    Shi Fushan

    2012-07-01

    Full Text Available Abstract Background Prion diseases are neurodegenerative disorders characterized by the accumulation of an abnormal disease-associated prion protein, PrPSc. In prion-infected brains, activated microglia are often present in the vicinity of PrPSc aggregates, and microglial activation is thought to play a key role in the pathogenesis of prion diseases. Although interleukin (IL-1β release by prion-induced microglia has been widely reported, the mechanism by which primed microglia become activated and secrete IL-1β in prion diseases has not yet been elucidated. In this study, we investigated the role of the NACHT, LRR and PYD domains-containing protein (NALP3 inflammasome in IL-1β release from lipopolysaccharide (LPS-primed microglia after exposure to a synthetic neurotoxic prion fragment (PrP106-126. Methods The inflammasome components NALP3 and apoptosis-associated speck-like protein (ASC were knocked down by gene silencing. IL-1β production was assessed using ELISA. The mRNA expression of NALP3, ASC, and pro-inflammatory factors was measured by quantitative PCR. Western blot analysis was used to detect the protein level of NALP3, ASC, caspase-1 and nuclear factor-κB. Results We found that that PrP106-126-induced IL-1β release depends on NALP3 inflammasome activation, that inflammasome activation is required for the synthesis of pro-inflammatory and chemotactic factors by PrP106-126-activated microglia, that inhibition of NF-κB activation abrogated PrP106-126-induced NALP3 upregulation, and that potassium efflux and production of reactive oxygen species were implicated in PrP106-126-induced NALP3 inflammasome activation in microglia. Conclusions We conclude that the NALP3 inflammasome is involved in neurotoxic prion peptide-induced microglial activation. To our knowledge, this is the first time that strong evidence for the involvement of NALP3 inflammasome in prion-associated inflammation has been found.

  16. Preventive Effects of a Fermented Dairy Product against Alzheimer’s Disease and Identification of a Novel Oleamide with Enhanced Microglial Phagocytosis and Anti-Inflammatory Activity

    Science.gov (United States)

    Ano, Yasuhisa; Ozawa, Makiko; Kutsukake, Toshiko; Sugiyama, Shinya; Uchida, Kazuyuki; Yoshida, Aruto; Nakayama, Hiroyuki

    2015-01-01

    Despite the ever-increasing number of patients with dementia worldwide, fundamental therapeutic approaches to this condition have not been established. Epidemiological studies suggest that intake of fermented dairy products prevents cognitive decline in the elderly. However, the active compounds responsible for the effect remain to be elucidated. The present study aims to elucidate the preventive effects of dairy products on Alzheimer’s disease and to identify the responsible component. Here, in a mouse model of Alzheimer’s disease (5xFAD), intake of a dairy product fermented with Penicillium candidum had preventive effects on the disease by reducing the accumulation of amyloid β (Aβ) and hippocampal inflammation (TNF-α and MIP-1α production), and enhancing hippocampal neurotrophic factors (BDNF and GDNF). A search for preventive substances in the fermented dairy product identified oleamide as a novel dual-active component that enhanced microglial Aβ phagocytosis and anti-inflammatory activity towards LPS stimulation in vitro and in vivo. During the fermentation, oleamide was synthesized from oleic acid, which is an abundant component of general dairy products owing to lipase enzymatic amidation. The present study has demonstrated the preventive effect of dairy products on Alzheimer’s disease, which was previously reported only epidemiologically. Moreover, oleamide has been identified as an active component of dairy products that is considered to reduce Aβ accumulation via enhanced microglial phagocytosis, and to suppress microglial inflammation after Aβ deposition. Because fermented dairy products such as camembert cheese are easy to ingest safely as a daily meal, their consumption might represent a preventive strategy for dementia. PMID:25760987

  17. Zigzag turning preference of freely crawling cells.

    Directory of Open Access Journals (Sweden)

    Taeseok Daniel Yang

    Full Text Available The coordinated motion of a cell is fundamental to many important biological processes such as development, wound healing, and phagocytosis. For eukaryotic cells, such as amoebae or animal cells, the cell motility is based on crawling and involves a complex set of internal biochemical events. A recent study reported very interesting crawling behavior of single cell amoeba: in the absence of an external cue, free amoebae move randomly with a noisy, yet, discernible sequence of 'run-and-turns' analogous to the 'run-and-tumbles' of swimming bacteria. Interestingly, amoeboid trajectories favor zigzag turns. In other words, the cells bias their crawling by making a turn in the opposite direction to a previous turn. This property enhances the long range directional persistence of the moving trajectories. This study proposes that such a zigzag crawling behavior can be a general property of any crawling cells by demonstrating that 1 microglia, which are the immune cells of the brain, and 2 a simple rule-based model cell, which incorporates the actual biochemistry and mechanics behind cell crawling, both exhibit similar type of crawling behavior. Almost all legged animals walk by alternating their feet. Similarly, all crawling cells appear to move forward by alternating the direction of their movement, even though the regularity and degree of zigzag preference vary from one type to the other.

  18. c-Src activity is differentially required by cancer cell motility modes.

    Science.gov (United States)

    Logue, Jeremy S; Cartagena-Rivera, Alexander X; Chadwick, Richard S

    2018-04-01

    Cancer cell migration requires that cells respond and adapt to their surroundings. In the absence of extracellular matrix cues, cancer cells will undergo a mesenchymal to ameboid transition, whereas a highly confining space will trigger a switch to "leader bleb-based" migration. To identify oncogenic signaling pathways mediating these transitions, we undertook a targeted screen using clinically useful inhibitors. Elevated Src activity was found to change actin and focal adhesion dynamics, whereas inhibiting Src triggered focal adhesion disassembly and blebbing. On non-adherent substrates and in collagen matrices, amoeboid-like, blebbing cells having high Src activity formed protrusions of the plasma membrane. To evaluate the role of Src in confined cells, we use a novel approach that places cells under a slab of polydimethylsiloxane (PDMS), which is held at a defined height. Using this method, we find that leader bleb-based migration is resistant to Src inhibition. High Src activity was found to markedly change the architecture of cortical actomyosin, reduce cell mechanical properties, and the percentage of cells that undergo leader bleb-based migration. Thus, Src is a signal transducer that can potently influence transitions between migration modes with implications for the rational development of metastasis inhibitors.

  19. Gabapentin reduces CX3CL1 signaling and blocks spinal microglial activation in monoarthritic rats

    Directory of Open Access Journals (Sweden)

    Yang Jia-Le

    2012-05-01

    Full Text Available Abstract Background Spinal glia, particularly microglia and astrocytes, are of the utmost importance in the development and maintenance of chronic pain. A recent study from our laboratory revealed that gabapentin, a recommended first-line treatment for multiple neuropathic conditions, could also efficiently antagonize thermal hyperalgesia evoked by complete Freund's adjuvant (CFA-induced monoarthritis (MA. In the present study, we investigated whether the spinal glia are involved in the anti-hyperalgesic effect of gabapentin and how this event occurs. Results Unilateral intra-articular injection of CFA produced a robust activation of microglia and astrocytes. These cells exhibited large cell bodies, thick processes and increases in the ionized calcium binding adapter molecule 1 (Iba-1, a microglial marker or the glia fibrillary acidic protein (GFAP, an astrocytic marker. These cells also displayed immunoreactive signals, and an upregulation of the voltage-gated calcium channels (VGCCs α2/δ-1 subunit, CX3CL1 and CX3CR1 expression levels in the spinal cord. These changes were associated with the development of thermal hyperalgesia. Immunofluorescence staining showed that VGCC α2/δ-1 subunit, a proposed gabapentin target of action, was widely distributed in primary afferent fibers terminals and dorsal horn neurons. CX3CL1, a potential trigger to activate microglia, colocalized with VGCC α2/δ-1 subunits in the spinal dorsal horn. However, its receptor CX3CR1 was mainly expressed in the spinal microglia. Multiple intraperitoneal (i.p. gabapentin injections (100 mg/kg, once daily for 4 days with the first injection 60 min before intra-articular CFA suppressed the activation of spinal microglia, downregulated spinal VGCC α2/δ-1 subunits decreased CX3CL1 levels and blocked the development of thermal hyperalgesia in MA rats. Conclusions Here we provide the first evidence that gabapentin diminishes CX3CL1 signaling and spinal microglia

  20. Vanillin Protects Dopaminergic Neurons against Inflammation-Mediated Cell Death by Inhibiting ERK1/2, P38 and the NF-κB Signaling Pathway.

    Science.gov (United States)

    Yan, Xuan; Liu, Dian-Feng; Zhang, Xiang-Yang; Liu, Dong; Xu, Shi-Yao; Chen, Guang-Xin; Huang, Bing-Xu; Ren, Wen-Zhi; Wang, Wei; Fu, Shou-Peng; Liu, Ju-Xiong

    2017-02-12

    Neuroinflammation plays a very important role in the pathogenesis of Parkinson's disease (PD). After activation, microglia produce pro-inflammatory mediators that damage surrounding neurons. Consequently, the inhibition of microglial activation might represent a new therapeutic approach of PD. Vanillin has been shown to protect dopaminergic neurons, but the mechanism is still unclear. Herein, we further study the underlying mechanisms in lipopolysaccharide (LPS)-induced PD models. In vivo, we firstly established rat models of PD by unilateral injection of LPS into substantia nigra (SN), and then examined the role of vanillin in motor dysfunction, microglial activation and degeneration of dopaminergic neurons. In vitro, murine microglial BV-2 cells were treated with vanillin prior to the incubation of LPS, and then the inflammatory responses and the related signaling pathways were analyzed. The in vivo results showed that vanillin markedly improved the motor dysfunction, suppressed degeneration of dopaminergic neurons and inhibited microglial over-activation induced by LPS intranigral injection. The in vitro studies demonstrated that vanillin reduces LPS-induced expression of inducible nitric oxide (iNOS), cyclooxygenase-2 (COX-2), IL-1β, and IL-6 through regulating ERK1/2, p38 and NF-κB signaling. Collectively, these data indicated that vanillin has a role in protecting dopaminergic neurons via inhibiting inflammatory activation.

  1. Interleukin-1 exerts distinct actions on different cell types of the brain in vitro

    Directory of Open Access Journals (Sweden)

    Ying An

    2011-01-01

    Full Text Available Ying An, Qun Chen, Ning QuanDepartment of Oral Biology, Ohio State University, Columbus, OH, USAAbstract: Interleukin-1 (IL-1 is a critical neuroinflammatory mediator in the central nervous system (CNS. In this study, we investigated the effect of IL-1 on inducing inflammation-related gene expression in three astrocyte, two microglial, and one brain endothelial cell line. Interleukin-1 beta (IL-1β is found to be produced by the two microglial cell lines constitutively, but these cells do not respond to IL-1β stimulation. The three astrocyte cell lines responded to IL-1ß stimulation by expressing MCP-1, CXCL-1, and VCAM-1, but different subtypes of astrocytes exhibited different expression profiles after IL-1β stimulation. The brain endothelial cells showed strongest response to IL-1β by producing MCP-1, CXCL-1, VCAM-1, ICAM-1, IL-6, and COX-2 mRNA. The induction of endothelial COX-2 mRNA is shown to be mediated by p38 MAPK pathway, whereas the induction of other genes is mediated by the NF-κB pathway. These results demonstrate that IL-1 exerts distinct cell type-specific action in CNS cells and suggest that IL-1-mediated neuroinflammation is the result of the summation of multiple responses from different cell types in the CNS to IL-1.Keywords: astrocyte, microglia, endothelial cells, signal transduction pathways, gene expression 

  2. Neuronal precursor cell proliferation in the hippocampus after transient cerebral ischemia: a comparative study of two rat strains using stereological tools

    DEFF Research Database (Denmark)

    Kelsen, Jesper; Larsen, Marianne; Sørensen, Jens Christian H.

    2010-01-01

    We are currently investigating microglial activation and neuronal precursor cell (NPC) proliferation after transient middle cerebral artery occlusion (tMCAo) in rats. This study aimed: (1) to investigate differences in hippocampal NPC proliferation in outbred male spontaneously hypertensive rats ...

  3. Dystrophic microglia in the aging human brain.

    Science.gov (United States)

    Streit, Wolfgang J; Sammons, Nicole W; Kuhns, Amanda J; Sparks, D Larry

    2004-01-15

    We have studied microglial morphology in the human cerebral cortex of two nondemented subjects using high-resolution LN-3 immunohistochemistry. Several abnormalities in microglial cytoplasmic structure, including deramification, spheroid formation, gnarling, and fragmentation of processes, were identified. These changes were determined to be different from the morphological changes that occur during microglial activation and they were designated collectively as microglial dystrophy. Quantitative evaluation of dystrophic changes in microglia revealed that these were much more prevalent in the older subject (68-year-old) than in the younger one (38-year-old). Thus, we conclude that microglial dystrophy is a sign of microglial cell senescence. We hypothesize that microglial senescence could be important for understanding age-related declines in cognitive function. Copyright 2003 Wiley-Liss, Inc.

  4. Hepatitis C Virus NS3 Mediated Microglial Inflammation via TLR2/TLR6 MyD88/NF-κB Pathway and Toll Like Receptor Ligand Treatment Furnished Immune Tolerance.

    Directory of Open Access Journals (Sweden)

    Ayilam Ramachandran Rajalakshmy

    Full Text Available Recent evidence suggests the neurotrophic potential of hepatitis C virus (HCV. HCV NS3 protein is one of the potent antigens of this virus mediating inflammatory response in different cell types. Microglia being the immune surveillance cells in the central nervous system (CNS, the inflammatory potential of NS3 on microglia was studied. Role of toll like receptor (TLR ligands Pam2CSK3 and Pam3CSK4 in controlling the NS3 mediated microglial inflammation was studied using microglial cell line CHME3.IL (Interleukin-8, IL-6, TNF-α (Tumor nicrosis factor alpha and IL-1β gene expressions were measured by semi quantitative RT-PCR (reverse transcription-PCR. ELISA was performed to detect IL-8, IL-6, TNF-α, IL-1β and IL-10 secretion. FACS (Flourescent activated cell sorting was performed to quantify TLR1, TLR2, TLR6, MyD88 (Myeloid differntiation factor 88, IkB-α (I kappaB alpha and pNF-κB (phosphorylated nuclear factor kappaB expression. Immunofluorescence staining was performed for MyD88, TLR6 and NF-κB (Nuclear factor kappaB. Student's t-test or One way analysis of variance with Bonferoni post hoc test was performed and p < 0.05 was considered significant.Microglia responded to NS3 by secreting IL-8, IL-6, TNF-α and IL-1β via TLR2 or TLR6 mediated MyD88/NF-κB pathway. Transcription factor NF-κB was involved in activating the cytokine gene expression and the resultant inflammatory response was controlled by NF-κB inhibitor, Ro106-9920, which is known to down regulate pro-inflammatory cytokine secretion. Activation of the microglia by TLR agonists Pam3CSK4 and Pam2CSK4 induced immune tolerance against NS3. TLR ligand treatment significantly down regulated pro-inflammatory cytokine secretion in the microglia. IL-10 secretion was suggested as the possible mechanism by which TLR agonists induced immune tolerance. NS3 as such was not capable of self-inducing immune tolerance in microglia.In conclusion, NS3 protein was capable of activating

  5. Anti-inflammatory actions of a taurine analogue, ethane β-sultam, in phagocytic cells, in vivo and in vitro.

    Science.gov (United States)

    Ward, Roberta J; Lallemand, Frederic; de Witte, Philippe; Crichton, Robert R; Piette, Jacques; Tipton, Keith; Hemmings, Karl; Pitard, Arnaud; Page, Mike; Della Corte, Laura; Taylor, Deanna; Dexter, David

    2011-03-15

    The ability of a taurine prodrug, ethane β-sultam, to reduce cellular inflammation has been investigated, in vitro, in primary cultures of alveolar macrophages and an immortilised N9 microglial cell line and in vivo in an animal model of inflammation and control rats. Ethane β-sultam showed enhanced ability to reduce the inflammatory response in alveolar macrophages, as assayed by the lipopolysaccharide-stimulated-nitric oxide release, (LPS stimulated-NO), in comparison to taurine both in vitro (10 nM, 50 nM) and in vivo (0.15 mmol/kg/day by gavage). In addition, ethane β-sultam, (50, 100 and 1000 nM) significantly reduced LPS-stimulated glutamate release from N9 microglial cells to a greater extent than taurine. The anti-inflammatory response of taurine was shown to be mediated via stabilisation of IkBα. The use of a taurine prodrug as therapeutic agents, for the treatment of neurological conditions, such as Parkinson's and Alzheimer's disease and alcoholic brain damage, where activated phagocytic cells contribute to the pathogenesis, may be of great potential. Copyright © 2011 Elsevier Inc. All rights reserved.

  6. SCM-198 inhibits microglial overactivation and attenuates Aβ(1-40)-induced cognitive impairments in rats via JNK and NF-кB pathways.

    Science.gov (United States)

    Hong, Zhen-Yi; Shi, Xue-Ru; Zhu, Kai; Wu, Ting-Ting; Zhu, Yi-Zhun

    2014-08-19

    Neuroinflammation mediated by overactivated microglia plays a key role in many neurodegenerative diseases, including Alzheimer's disease (AD). In this study, we investigated for the first time the anti-neuroinflammatory effects and possible mechanisms of SCM-198 (an alkaloid extracted from Herbaleonuri), which was previously found highly cardioprotective, both in vitro and in vivo. For in vitro experiments, lipopolysaccharide (LPS) or β-amyloid(1-40) (Aβ(1-40)) was applied to induce microglial overactivation. Proinflammatory mediators were measured and activations of NF-κB and mitogen-activated protein kinases' (MAPKs) pathways were investigated. Further protective effect of SCM-198 was evaluated in microglia-neuron co-culture assay and Sprague-Dawley (SD) rats intrahippocampally-injected with Aβ(1-40). SCM-198 reduced expressions of nitric oxide (NO), TNF-α, IL-1β and IL-6 possibly via, at least partially, inhibiting c-Jun N-terminal kinase (JNK) and NF-κB signaling pathways in microglia. Co-culture assay showed that activated microglia pretreated with SCM-198 led to less neuron loss and decreased phosphorylation of tau and extracellular signal-regulated kinase (ERK) in neurons. Besides, SCM-198 also directly protected against Aβ(1-40)-induced neuronal death and lactate dehydrogenase (LDH) release in primary cortical neurons. For in vivo studies, SCM-198 significantly enhanced cognitive performances of rats 12 days after intrahippocampal injections of aged Aβ(1-40) peptides in the Morris water maze (MWM), accompanied by less hippocampal microglial activation, decreased synaptophysin loss and phosphorylation of ERK and tau. Co-administration of donepezil and SCM-198 resulted in a slight cognitive improvement in SD rats 50 days after intrahippocampal injections of aged Aβ(1-40) peptides as compared to only donepezil or SCM-198 treated group. Our findings are the first to report that SCM-198 has considerable anti-neuroinflammatory effects on inhibiting

  7. Functional Studies of Missense TREM2 Mutations in Human Stem Cell-Derived Microglia

    Directory of Open Access Journals (Sweden)

    Philip W. Brownjohn

    2018-04-01

    Full Text Available Summary: The derivation of microglia from human stem cells provides systems for understanding microglial biology and enables functional studies of disease-causing mutations. We describe a robust method for the derivation of human microglia from stem cells, which are phenotypically and functionally comparable with primary microglia. We used stem cell-derived microglia to study the consequences of missense mutations in the microglial-expressed protein triggering receptor expressed on myeloid cells 2 (TREM2, which are causal for frontotemporal dementia-like syndrome and Nasu-Hakola disease. We find that mutant TREM2 accumulates in its immature form, does not undergo typical proteolysis, and is not trafficked to the plasma membrane. However, in the absence of plasma membrane TREM2, microglia differentiate normally, respond to stimulation with lipopolysaccharide, and are phagocytically competent. These data indicate that dementia-associated TREM2 mutations have subtle effects on microglia biology, consistent with the adult onset of disease in individuals with these mutations. : Brownjohn and colleagues report methods to generate microglia from induced pluripotent human stem cells, which they demonstrate are highly similar to cultured primary human microglia. Microglia differentiated from patient-derived stem cells carrying neurological disease-causing mutations in the TREM2 receptor differentiate normally and respond appropriately to pathogenic stimuli, despite the absence of functional TREM2 receptor on the plasma membrane. Keywords: dementia, microglia, TREM2, Nasu-Hakola disease, frontotemporal dementia, iPSC-microglia, neuroinflammation

  8. Method to investigate temporal dynamics of ganglion and other retinal cells in the living human eye

    Science.gov (United States)

    Kurokawa, Kazuhiro; Liu, Zhuolin; Crowell, James; Zhang, Furu; Miller, Donald T.

    2018-02-01

    The inner retina is critical for visual processing, but much remains unknown about its neural circuitry and vulnerability to disease. A major bottleneck has been our inability to observe the structure and function of the cells composing these retinal layers in the living human eye. Here, we present a noninvasive method to observe both structural and functional information. Adaptive optics optical coherence tomography (AO-OCT) is used to resolve the inner retinal cells in all three dimensions and novel post processing algorithms are applied to extract structure and physiology down to the cellular level. AO-OCT captured the 3D mosaic of individual ganglion cell somas, retinal nerve fiber bundles of micron caliber, and microglial cells, all in exquisite detail. Time correlation analysis of the AO-OCT videos revealed notable temporal differences between the principal layers of the inner retina. The GC layer was more dynamic than the nerve fiber and inner plexiform layers. At the cellular level, we applied a customized correlation method to individual GCL somas, and found a mean time constant of activity of 0.57 s and spread of +/-0.1 s suggesting a range of physiological dynamics even in the same cell type. Extending our method to slower dynamics (from minutes to one year), time-lapse imaging and temporal speckle contrast revealed appendage and soma motion of resting microglial cells at the retinal surface.

  9. In vivo changes in microglial activation and amyloid deposits in brain regions with hypometabolism in Alzheimer's disease

    International Nuclear Information System (INIS)

    Yokokura, Masamichi; Mori, Norio; Yoshihara, Yujiro; Wakuda, Tomoyasu; Takebayashi, Kiyokazu; Iwata, Yasuhide; Nakamura, Kazuhiko; Yagi, Shunsuke; Ouchi, Yasuomi; Yoshikawa, Etsuji; Kikuchi, Mitsuru; Sugihara, Genichi; Suda, Shiro; Tsuchiya, Kenji J.; Suzuki, Katsuaki; Ueki, Takatoshi

    2011-01-01

    Amyloid β protein (Aβ) is known as a pathological substance in Alzheimer's disease (AD) and is assumed to coexist with a degree of activated microglia in the brain. However, it remains unclear whether these two events occur in parallel with characteristic hypometabolism in AD in vivo. The purpose of the present study was to clarify the in vivo relationship between Aβ accumulation and neuroinflammation in those specific brain regions in early AD. Eleven nootropic drug-naive AD patients underwent a series of positron emission tomography (PET) measurements with [ 11 C](R)PK11195, [ 11 C]PIB and [ 18 F]FDG and a battery of cognitive tests within the same day. The binding potentials (BPs) of [ 11 C](R)PK11195 were directly compared with those of [ 11 C]PIB in the brain regions with reduced glucose metabolism. BPs of [ 11 C](R)PK11195 and [ 11 C]PIB were significantly higher in the parietotemporal regions of AD patients than in ten healthy controls. In AD patients, there was a negative correlation between dementia score and [ 11 C](R)PK11195 BPs, but not [ 11 C]PIB, in the limbic, precuneus and prefrontal regions. Direct comparisons showed a significant negative correlation between [ 11 C](R)PK11195 and [ 11 C]PIB BPs in the posterior cingulate cortex (PCC) (p 18 F]FDG uptake. A lack of coupling between microglial activation and amyloid deposits may indicate that Aβ accumulation shown by [ 11 C]PIB is not always the primary cause of microglial activation, but rather the negative correlation present in the PCC suggests that microglia can show higher activation during the production of Aβ in early AD. (orig.)

  10. Fluoxetine treatment affects the inflammatory response and microglial function according to the quality of the living environment.

    Science.gov (United States)

    Alboni, Silvia; Poggini, Silvia; Garofalo, Stefano; Milior, Giampaolo; El Hajj, Hassan; Lecours, Cynthia; Girard, Isabelle; Gagnon, Steven; Boisjoly-Villeneuve, Samuel; Brunello, Nicoletta; Wolfer, David P; Limatola, Cristina; Tremblay, Marie-Ève; Maggi, Laura; Branchi, Igor

    2016-11-01

    It has been hypothesized that selective serotonin reuptake inhibitors (SSRIs), the most common treatment for major depression, affect mood through changes in immune function. However, the effects of SSRIs on inflammatory response are contradictory since these act either as anti- or pro-inflammatory drugs. Previous experimental and clinical studies showed that the quality of the living environment moderates the outcome of antidepressant treatment. Therefore, we hypothesized that the interplay between SSRIs and the environment may, at least partially, explain the apparent incongruence regarding the effects of SSRI treatment on the inflammatory response. In order to investigate such interplay, we exposed C57BL/6 mice to chronic stress to induce a depression-like phenotype and, subsequently, to fluoxetine treatment or vehicle (21days) while being exposed to either an enriched or a stressful condition. At the end of treatment, we measured the expression levels of several anti- and pro-inflammatory cytokines and inflammatory mediators in the whole hippocampus and in isolated microglia. We also determined microglial density, distribution, and morphology to investigate their surveillance state. Results show that the effects of fluoxetine treatment on inflammation and microglial function, as compared to vehicle, were dependent on the quality of the living environment. In particular, fluoxetine administered in the enriched condition increased the expression of pro-inflammatory markers compared to vehicle, while treatment in a stressful condition produced anti-inflammatory effects. These findings provide new insights regarding the effects of SSRIs on inflammation, which may be crucial to devise pharmacological strategies aimed at enhancing antidepressant efficacy by means of controlling environmental conditions. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Sleep deprivation aggravates median nerve injury-induced neuropathic pain and enhances microglial activation by suppressing melatonin secretion.

    Science.gov (United States)

    Huang, Chun-Ta; Chiang, Rayleigh Ping-Ying; Chen, Chih-Li; Tsai, Yi-Ju

    2014-09-01

    Sleep deprivation is common in patients with neuropathic pain, but the effect of sleep deprivation on pathological pain remains uncertain. This study investigated whether sleep deprivation aggravates neuropathic symptoms and enhances microglial activation in the cuneate nucleus (CN) in a median nerve chronic constriction injury (CCI) model. Also, we assessed if melatonin supplements during the sleep deprived period attenuates these effects. Rats were subjected to sleep deprivation for 3 days by the disc-on-water method either before or after CCI. In the melatonin treatment group, CCI rats received melatonin supplements at doses of 37.5, 75, 150, or 300 mg/kg during sleep deprivation. Melatonin was administered at 23:00 once a day. Male Sprague-Dawley rats, weighing 180-250 g (n = 190), were used. Seven days after CCI, behavioral testing was conducted, and immunohistochemistry, immunoblotting, and enzyme-linked immunosorbent assay were used for qualitative and quantitative analyses of microglial activation and measurements of proinflammatory cytokines. In rats who underwent post-CCI sleep deprivation, microglia were more profoundly activated and neuropathic pain was worse than those receiving pre-CCI sleep deprivation. During the sleep deprived period, serum melatonin levels were low over the 24-h period. Administration of melatonin to CCI rats with sleep deprivation significantly attenuated activation of microglia and development of neuropathic pain, and markedly decreased concentrations of proinflammatory cytokines. Sleep deprivation makes rats more vulnerable to nerve injury-induced neuropathic pain, probably because of associated lower melatonin levels. Melatonin supplements to restore a circadian variation in melatonin concentrations during the sleep deprived period could alleviate nerve injury-induced behavioral hypersensitivity. © 2014 Associated Professional Sleep Societies, LLC.

  12. Comparison of microglia and infiltrating CD11c+ cells as antigen presenting cells for T cell proliferation and cytokine response

    DEFF Research Database (Denmark)

    Wlodarczyk, Agnieszka; Løbner, Morten; Cédile, Oriane

    2014-01-01

    BACKGROUND: Tissue-resident antigen-presenting cells (APC) exert a major influence on the local immune environment. Microglia are resident myeloid cells in the central nervous system (CNS), deriving from early post-embryonic precursors, distinct from adult hematopoietic lineages. Dendritic cells...... (DC) and macrophages infiltrate the CNS during experimental autoimmune encephalomyelitis (EAE). Microglia are not considered to be as effective APC as DC or macrophages. METHODS: In this work we compared the antigen presenting capacity of CD11c+ and CD11c- microglia subsets with infiltrating CD11c......+ APC, which include DC. The microglial subpopulations (CD11c- CD45dim CD11b+ and CD11c+ CD45dim CD11b+) as well as infiltrating CD11c+ CD45high cells were sorted from CNS of C57BL/6 mice with EAE. Sorted cells were characterised by flow cytometry for surface phenotype and by quantitative real-time PCR...

  13. Amoeboid swimming: a generic self-propulsion of cells in fluids by means of membrane deformations.

    Science.gov (United States)

    Farutin, Alexander; Rafaï, Salima; Dysthe, Dag Kristian; Duperray, Alain; Peyla, Philippe; Misbah, Chaouqi

    2013-11-27

    Microorganisms, such as bacteria, algae, or spermatozoa, are able to propel themselves forward thanks to flagella or cilia activity. By contrast, other organisms employ pronounced changes of the membrane shape to achieve propulsion, a prototypical example being the Eutreptiella gymnastica. Cells of the immune system as well as dictyostelium amoebas, traditionally believed to crawl on a substratum, can also swim in a similar way. We develop a model for these organisms: the swimmer is mimicked by a closed incompressible membrane with force density distribution (with zero total force and torque). It is shown that fast propulsion can be achieved with adequate shape adaptations. This swimming is found to consist of an entangled pusher-puller state. The autopropulsion distance over one cycle is a universal linear function of a simple geometrical dimensionless quantity A/V(2/3) (V and A are the cell volume and its membrane area). This study captures the peculiar motion of Eutreptiella gymnastica with simple force distribution.

  14. Vanillin Protects Dopaminergic Neurons against Inflammation-Mediated Cell Death by Inhibiting ERK1/2, P38 and the NF-κB Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Xuan Yan

    2017-02-01

    Full Text Available Neuroinflammation plays a very important role in the pathogenesis of Parkinson’s disease (PD. After activation, microglia produce pro-inflammatory mediators that damage surrounding neurons. Consequently, the inhibition of microglial activation might represent a new therapeutic approach of PD. Vanillin has been shown to protect dopaminergic neurons, but the mechanism is still unclear. Herein, we further study the underlying mechanisms in lipopolysaccharide (LPS-induced PD models. In vivo, we firstly established rat models of PD by unilateral injection of LPS into substantia nigra (SN, and then examined the role of vanillin in motor dysfunction, microglial activation and degeneration of dopaminergic neurons. In vitro, murine microglial BV-2 cells were treated with vanillin prior to the incubation of LPS, and then the inflammatory responses and the related signaling pathways were analyzed. The in vivo results showed that vanillin markedly improved the motor dysfunction, suppressed degeneration of dopaminergic neurons and inhibited microglial over-activation induced by LPS intranigral injection. The in vitro studies demonstrated that vanillin reduces LPS-induced expression of inducible nitric oxide (iNOS, cyclooxygenase-2 (COX-2, IL-1β, and IL-6 through regulating ERK1/2, p38 and NF-κB signaling. Collectively, these data indicated that vanillin has a role in protecting dopaminergic neurons via inhibiting inflammatory activation.

  15. Evidence for a novel chemotactic C1q domain-containing factor in the leech nerve cord.

    Science.gov (United States)

    Tahtouh, Muriel; Croq, Françoise; Vizioli, Jacopo; Sautiere, Pierre-Eric; Van Camp, Christelle; Salzet, Michel; Daha, Mohamed R; Pestel, Joël; Lefebvre, Christophe

    2009-02-01

    In vertebrates, central nervous system (CNS) protection is dependent on many immune cells including microglial cells. Indeed, activated microglial cells are involved in neuroinflammation mechanisms by interacting with numerous immune factors. Unlike vertebrates, some lophotrochozoan invertebrates can fully repair their CNS following injury. In the medicinal leech Hirudo medicinalis, the recruitment of microglial cells at the lesion site is essential for sprouting of injured axons. Interestingly, a new molecule homologous to vertebrate C1q was characterized in leech, named HmC1q (for H. medicinalis) and detected in neurons and glial cells. In chemotaxis assays, leech microglial cells were demonstrated to respond to human C1q. The chemotactic activity was reduced when microglia was preincubated with signaling pathway inhibitors (Pertussis Toxin or wortmannin) or anti-human gC1qR antibody suggesting the involvement of gC1qR in C1q-mediated migration in leech. Assays using cells preincubated with NO chelator (cPTIO) showed that C1q-mediated migration was associated to NO production. Of interest, by using anti-HmC1q antibodies, HmC1q released in the culture medium was shown to exhibit a similar chemotactic effect on microglial cells as human C1q. In summary, we have identified, for the first time, a molecule homologous to mammalian C1q in leech CNS. Its chemoattractant activity on microglia highlights a new investigation field leading to better understand leech CNS repair mechanisms.

  16. Over-expression of Oct4 and Sox2 transcription factors enhances differentiation of human umbilical cord blood cells in vivo

    International Nuclear Information System (INIS)

    Guseva, Daria; Rizvanov, Albert A.; Salafutdinov, Ilnur I.; Kudryashova, Nezhdana V.; Palotás, András; Islamov, Rustem R.

    2014-01-01

    Highlights: • Gene and cell-based therapies comprise innovative aspects of regenerative medicine. • Genetically modified hUCB-MCs enhanced differentiation of cells in a mouse model of ALS. • Stem cells successfully transformed into micro-glial and endothelial lines in spinal cords. • Over-expressing oct4 and sox2 also induced production of neural marker PGP9.5. • Formation of new nerve cells, secreting trophic factors and neo-vascularisation could improve symptoms in ALS. - Abstract: Gene and cell-based therapies comprise innovative aspects of regenerative medicine. Even though stem cells represent a highly potential therapeutic strategy, their wide-spread exploitation is marred by ethical concerns, potential for malignant transformation and a plethora of other technical issues, largely restricting their use to experimental studies. Utilizing genetically modified human umbilical cord blood mono-nuclear cells (hUCB-MCs), this communication reports enhanced differentiation of transplants in a mouse model of amyotrophic lateral sclerosis (ALS). Over-expressing Oct4 and Sox2 induced production of neural marker PGP9.5, as well as transformation of hUCB-MCs into micro-glial and endothelial lines in ALS spinal cords. In addition to producing new nerve cells, providing degenerated areas with trophic factors and neo-vascularisation might prevent and even reverse progressive loss of moto-neurons and skeletal muscle paralysis

  17. Over-expression of Oct4 and Sox2 transcription factors enhances differentiation of human umbilical cord blood cells in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Guseva, Daria [Kazan State Medical University, Kazan, Republic of Tatarstan (Russian Federation); Hannover Medical School, Hannover (Germany); Rizvanov, Albert A.; Salafutdinov, Ilnur I.; Kudryashova, Nezhdana V. [Kazan Federal University, Kazan, Republic of Tatarstan (Russian Federation); Palotás, András, E-mail: palotas@asklepios-med.eu [Kazan Federal University, Kazan, Republic of Tatarstan (Russian Federation); Asklepios-Med (Private Medical Practice and Research Center), Szeged (Hungary); Islamov, Rustem R., E-mail: islamru@yahoo.com [Kazan State Medical University, Kazan, Republic of Tatarstan (Russian Federation)

    2014-09-05

    Highlights: • Gene and cell-based therapies comprise innovative aspects of regenerative medicine. • Genetically modified hUCB-MCs enhanced differentiation of cells in a mouse model of ALS. • Stem cells successfully transformed into micro-glial and endothelial lines in spinal cords. • Over-expressing oct4 and sox2 also induced production of neural marker PGP9.5. • Formation of new nerve cells, secreting trophic factors and neo-vascularisation could improve symptoms in ALS. - Abstract: Gene and cell-based therapies comprise innovative aspects of regenerative medicine. Even though stem cells represent a highly potential therapeutic strategy, their wide-spread exploitation is marred by ethical concerns, potential for malignant transformation and a plethora of other technical issues, largely restricting their use to experimental studies. Utilizing genetically modified human umbilical cord blood mono-nuclear cells (hUCB-MCs), this communication reports enhanced differentiation of transplants in a mouse model of amyotrophic lateral sclerosis (ALS). Over-expressing Oct4 and Sox2 induced production of neural marker PGP9.5, as well as transformation of hUCB-MCs into micro-glial and endothelial lines in ALS spinal cords. In addition to producing new nerve cells, providing degenerated areas with trophic factors and neo-vascularisation might prevent and even reverse progressive loss of moto-neurons and skeletal muscle paralysis.

  18. Functional neurological symptom disorder (conversion disorder): A role for microglial-based plasticity mechanisms?

    Science.gov (United States)

    Stephenson, Chris P; Baguley, Ian J

    2018-02-01

    Functional Neurological Symptom Disorder (FND) is a relatively common neurological condition, accounting for approximately 3-6% of neurologist referrals. FND is considered a transient disorder of neuronal function, sometimes linked to physical trauma and psychological stress. Despite this, chronic disability is common, for example, around 40% of adults with motor FND have permanent disability. Building on current theoretical models, this paper proposes that microglial dysfunction could perpetuate functional changes within acute motor FND, thus providing a pathophysiological mechanism underlying the chronic stage of the motor FND phenotypes seen clinically. Core to our argument is microglia's dual role in modulating neuroimmunity and their control of synaptic plasticity, which places them at a pathophysiological nexus wherein coincident physical trauma and psychological stress could cause long-term change in neuronal networks without producing macroscopic structural abnormality. This model proposes a range of hypotheses that are testable with current technologies. Copyright © 2017. Published by Elsevier Ltd.

  19. Population control of resident and immigrant microglia by mitosis and apoptosis.

    Science.gov (United States)

    Wirenfeldt, Martin; Dissing-Olesen, Lasse; Anne Babcock, Alicia; Nielsen, Marianne; Meldgaard, Michael; Zimmer, Jens; Azcoitia, Iñigo; Leslie, Robert Graham Quinton; Dagnaes-Hansen, Frederik; Finsen, Bente

    2007-08-01

    Microglial population expansion occurs in response to neural damage via processes that involve mitosis and immigration of bone marrow-derived cells. However, little is known of the mechanisms that regulate clearance of reactive microglia, when microgliosis diminishes days to weeks later. We have investigated the mechanisms of microglial population control in a well-defined model of reactive microgliosis in the mouse dentate gyrus after perforant pathway axonal lesion. Unbiased stereological methods and flow cytometry demonstrate significant lesion-induced increases in microglial numbers. Reactive microglia often occurred in clusters, some having recently incorporated bromodeoxyuridine, showing that proliferation had occurred. Annexin V labeling and staining for activated caspase-3 and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling showed that apoptotic mechanisms participate in dissolution of the microglial response. Using bone marrow chimeric mice, we found that the lesion-induced proliferative capacity of resident microglia superseded that of immigrant microglia, whereas lesion-induced kinetics of apoptosis were comparable. Microglial numbers and responses were severely reduced in bone marrow chimeric mice. These results broaden our understanding of the microglial response to neural damage by demonstrating that simultaneously occurring mitosis and apoptosis regulate expansion and reduction of both resident and immigrant microglial cell populations.

  20. Microglia show altered morphology and reduced arborization in human brain during aging and Alzheimer's disease.

    Science.gov (United States)

    Davies, Danielle S; Ma, Jolande; Jegathees, Thuvarahan; Goldsbury, Claire

    2017-11-01

    Changes in microglia function are involved in Alzheimer's disease (AD) for which ageing is the major risk factor. We evaluated microglial cell process morphologies and their gray matter coverage (arborized area) during ageing and in the presence and absence of AD pathology in autopsied human neocortex. Microglial cell processes were reduced in length, showed less branching and reduced arborized area with aging (case range 52-98 years). This occurred during normal ageing and without microglia dystrophy or changes in cell density. There was a larger reduction in process length and arborized area in AD compared to aged-matched control microglia. In AD cases, on average, 49%-64% of microglia had discontinuous and/or punctate Iba1 labeled processes instead of continuous Iba1 distribution. Up to 16% of aged-matched control microglia displayed discontinuous or punctate features. There was no change in the density of microglial cell bodies in gray matter during ageing or AD. This demonstrates that human microglia show progressive cell process retraction without cell loss during ageing. Additional changes in microglia occur with AD including Iba1 protein puncta and discontinuity. We suggest that reduced microglial arborized area may be an aging-related correlate of AD in humans. These variations in microglial cells during ageing and in AD could reflect changes in neural-glial interactions which are emerging as key to mechanisms involved in ageing and neurodegenerative disease. © 2016 International Society of Neuropathology.

  1. Astrocytic and microglial response and histopathological changes in the brain of horses with experimental chronic Trypanosoma evansi infection Resposta astrocítica e microglial e alterações histopatológicas no sistema nervoso central de eqüinos infectados cronicamente com Trypanosoma evansi

    Directory of Open Access Journals (Sweden)

    Karen Regina Lemos

    2008-08-01

    Full Text Available This study aimed to characterize astrocytic and microglial response in the central nervous system (CNS of equines experimentally infected with T. evansi. The experimental group comprised males and females with various degrees of crossbreeding, ages between four and seven years. The animals were inoculated intravenously with 10(6 trypomastigotes of T. evansi originally isolated from a naturally infected dog. All equines inoculated with T. evansi were observed until they presented symptoms of CNS disturbance, characterized by motor incoordination of the pelvic limbs, which occurred 67 days after inoculation (DAI and 124 DAI. The animals in the control group did not present any clinical symptom and were observed up to the 125th DAI. For this purpose the HE histochemical stain and the avidin biotin peroxidase method was used. Lesions in the CNS of experimentally infected horses were those of a wide spread non suppurative meningoencephalomyelitis.The severity of lesions varied in different parts of the nervous system, reflecting an irregular distribution of inflammatory vascular changes. The infiltration of mononuclear cells was associated with anisomorphic gliosis and reactive microglia was identified. The intensity of the astrocytic response in the CNS of the equines infected by T. evansi characterizes the importance of the performance of these cells in this trypanosomiasis. The characteristic gliosis observed in the animals in this experiment suggests the ability of these cells as mediators of immune response. The parasite, T. evansi, was not identified in the nervous tissues.Este estudo objetivou caracterizar a participação astrocítica e microglial no sistema nervoso central (SNC de eqüinos experimentalmente infectados com T. evansi. O grupo experimental foi formado por machos e fêmeas com vários graus de cruzamentos e idade variando entre quatro e sete anos. Os animais foram inoculados com 10(6 tripomastigotas de T. evansi, originalmente

  2. TLR4 mutation reduces microglial activation, increases Aβ deposits and exacerbates cognitive deficits in a mouse model of Alzheimer's disease

    Directory of Open Access Journals (Sweden)

    Song Min

    2011-08-01

    Full Text Available Abstract Background Amyloid plaques, a pathological hallmark of Alzheimer's disease (AD, are accompanied by activated microglia. The role of activated microglia in the pathogenesis of AD remains controversial: either clearing Aβ deposits by phagocytosis or releasing proinflammatory cytokines and cytotoxic substances. Microglia can be activated via toll-like receptors (TLRs, a class of pattern-recognition receptors in the innate immune system. We previously demonstrated that an AD mouse model homozygous for a loss-of-function mutation of TLR4 had increases in Aβ deposits and buffer-soluble Aβ in the brain as compared with a TLR4 wild-type AD mouse model at 14-16 months of age. However, it is unknown if TLR4 signaling is involved in initiation of Aβ deposition as well as activation and recruitment of microglia at the early stage of AD. Here, we investigated the role of TLR4 signaling and microglial activation in early stages using 5-month-old AD mouse models when Aβ deposits start. Methods Microglial activation and amyloid deposition in the brain were determined by immunohistochemistry in the AD models. Levels of cerebral soluble Aβ were determined by ELISA. mRNA levels of cytokines and chemokines in the brain and Aβ-stimulated monocytes were quantified by real-time PCR. Cognitive functions were assessed by the Morris water maze. Results While no difference was found in cerebral Aβ load between AD mouse models at 5 months with and without TLR4 mutation, microglial activation in a TLR4 mutant AD model (TLR4M Tg was less than that in a TLR4 wild-type AD model (TLR4W Tg. At 9 months, TLR4M Tg mice had increased Aβ deposition and soluble Aβ42 in the brain, which were associated with decrements in cognitive functions and expression levels of IL-1β, CCL3, and CCL4 in the hippocampus compared to TLR4W Tg mice. TLR4 mutation diminished Aβ-induced IL-1β, CCL3, and CCL4 expression in monocytes. Conclusion This is the first demonstration of TLR4

  3. Fenofibrate dose not protect glioma cells from irradiation

    International Nuclear Information System (INIS)

    Ro, Jae Lim; Kim, Won Dong; Park, Woo Yoon

    2012-01-01

    Fenofibrate(FF) is a ligand for peroxisome proliferator-activated receptor (PPAR) α and used clinically as a hypolipidemic drug. FF has been reported to have a radioprotective effect of newborn cells in the dentate gyrus 1) and inhibit radiation-induced microglial pro-inflammatory response 2). However, if FF also protect tumor cells, it can not be used clinically during radiotherapy. Thus, we're interested in whether FF has an radioprotective effect of brain tumor cells or not Although the radiosensitive G0/G1 phase cells were increased, radiosensitization by FF was not observed in three human glioma cells. This may be due to counterbalance of radiosensitizing and radioprotecting proteins increased by FF. Taken together, FF neither radiosensitize nor radioprotect glioma cells, so it can be used to protect normal neural cells from radiation damage

  4. Strategies to increase the activity of microglia as efficient protectors of the brain against infections

    Directory of Open Access Journals (Sweden)

    Roland eNau

    2014-05-01

    Full Text Available In healthy individuals, infections of the CNS are comparatively rare. Based on the ability of microglial cells to phagocytose and kill pathogens and on clinical findings in immunocompromized patients with CNS infections, we hypothesize that an intact microglial function is crucial to protect the brain from infections. Phagocytosis of pathogens by microglial cells can be stimulated by agonists of receptors of the innate immune system. Enhancing this pathway to increase the resistance of the brain to infections entails the risk of inducing collateral damage to the nervous tissue. The diversity of microglial cells opens avenue to selectively stimulate sub-populations responsible for the defence against pathogens without stimulating sub-populations which are responsible for collateral damage to the nervous tissue. Palmitoylethanolamide (PEA, an endogenous lipid, increased phagocytosis of bacteria by microglial cells in vitro without a measurable proinflammatory effect. It was tested clinically apparently without severe side effects. Glatiramer acetate increased phagocytosis of latex beads by microglia and monocytes, and dimethyl fumarate enhanced elimination of human immunodeficiency virus from infected macrophages without inducing a release of proinflammatory compounds. Therefore, the discovery of compounds which stimulate the elimination of pathogens without collateral damage of neuronal structures appears an achievable goal. PEA and, with limitations, glatiramer acetate and dimethyl fumarate appear promising candidates.

  5. A dual role for microglia in promoting tissue inhibitor of metalloproteinase (TIMP expression in glial cells in response to neuroinflammatory stimuli

    Directory of Open Access Journals (Sweden)

    Milner Richard

    2011-06-01

    Full Text Available Abstract Background By neutralizing the effect of the matrix metalloproteinases (MMPs, the tissue inhibitors of matrix metalloproteinases (TIMPs play a critical role in maintaining tissue proteolysis in balance. As the major reactive glial cell types in the central nervous system (CNS, microglia and astrocytes play fundamental roles in mediating tissue breakdown and repair. As such, it is important to define the TIMP expression profile in these cells, as well as the mechanisms of regulation by neuroinflammatory stimuli. Methods Primary mixed glial cultures (MGC, pure microglia, and pure astrocytes were used in this study. To study astrocytes, we employed a recently described pure astrocyte culture system, which has the major advantage of totally lacking microglia. The three different types of culture were treated with lipopolysaccharide (LPS or individual cytokines, and cell culture supernatants assayed for TIMP-1 or TIMP-2 protein expression by western blot. Results LPS induced TIMP-1 expression in MGC, but not in pure astrocyte or microglial cultures. When pure astrocytes were treated with the cytokines IL-1β, IFN-γ, TNF or TGF-β1, only IL-1β induced TIMP-1 expression. Significantly, astrocyte TIMP-1 expression was restored in LPS-treated astrocyte cultures after the addition of microglia, or conditioned medium taken from LPS-activated microglia (MG-CM. Furthermore, this effect was lost after depletion of IL-1β from MG-CM. By contrast, TIMP-2 was constitutively expressed by astrocytes, whereas microglia expressed TIMP-2 only after exposure to serum. Conclusions Taken together, these results demonstrate an important concept in glial interactions, by showing that microglia play a central role in regulating glial cell expression of TIMPs, and identify microglial IL-1β as playing a key role in mediating microglial-astrocyte communication.

  6. Synergistic Use of Geniposide and Ginsenoside Rg1 Balance Microglial TNF-α and TGF-β1 following Oxygen-Glucose Deprivation In Vitro: A Genome-Wide Survey

    Directory of Open Access Journals (Sweden)

    Jun Wang

    2015-01-01

    Full Text Available Ischemia-activated microglia are like a double-edged sword, characterized by both neurotoxic and neuroprotective effects. The aim of this study was to reveal the synergistic effect of geniposide and ginsenoside Rg1 based on tumor necrosis factor- (TNF- α and transforming growth factor- (TGF- β1 balance of microglia. BV2 microglial cells were divided into 5 groups: control, model (oxygen-glucose deprivation (OGD, geniposide-treated, ginsenoside-Rg1-treated, and combination-treated. A series of assays were used to detect on (i cell viability; (ii NO content; (iii expression (content of TNF-α and TGF-β1; and (iv gene expression profiles. The results showed that integrated use of geniposide and ginsenoside Rg1 significantly inhibited NO level and protected cell viability, improved the content and expression of TGF-β1, and reduced the content and expression of TNF-α. Separated use of geniposide or ginsenoside Rg1 showed different effects at different emphases. Next-generation sequencing showed that Fcγ-receptor-mediated phagocytosis pathway played a key regulatory role in the balance of TNF-α and TGF-β1 when cotreated with geniposide and ginsenoside Rg1. These findings suggest that synergistic drug combination of geniposide and ginsenoside Rg1 in the treatment of stroke is a feasible avenue for the application.

  7. Minocycline Rescues from Zinc-Induced Nigrostriatal Dopaminergic Neurodegeneration: Biochemical and Molecular Interventions.

    Science.gov (United States)

    Kumar, Vinod; Singh, Brajesh Kumar; Chauhan, Amit Kumar; Singh, Deepali; Patel, Devendra Kumar; Singh, Chetna

    2016-07-01

    Accumulation of zinc (Zn) in dopaminergic neurons is implicated in Parkinson's disease (PD), and microglial activation plays a critical role in toxin-induced Parkinsonism. Oxidative stress is accused in Zn-induced dopaminergic neurodegeneration; however, its connection with microglial activation is still not known. This study was undertaken to elucidate the role and underlying mechanism of microglial activation in Zn-induced nigrostriatal dopaminergic neurodegeneration. Male Wistar rats were treated intraperitoneally with/without zinc sulphate (20 mg/kg) in the presence/absence of minocycline (30 mg/kg), a microglial activation inhibitor, for 2-12 weeks. While neurobehavioral and biochemical indexes of PD and number of dopaminergic neurons were reduced, the number of microglial cells was increased in the substantia nigra of the Zn-exposed animals. Similarly, Zn elevated lipid peroxidation (LPO) and activities of superoxide dismutase (SOD) and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase; however, catalase activity was reduced. Besides, Zn increased an association of NADPH oxidase subunit p67(phox) with membrane, cytochrome c release from the mitochondria and cleavage of pro-caspase 3. Zn attenuated the expression of tyrosine hydroxylase (TH) and vesicular monoamine transporter-2 (VMAT-2) while augmented the expression of dopamine transporter (DAT) and heme oxygenase-1 (HO-1). Minocycline alleviated Zn-induced behavioural impairments, loss of TH-positive neurons, activated microglial cells and biochemical indexes and modulated the expression of studied genes/proteins towards normalcy. The results demonstrate that minocycline reduces the number of activated microglial cells and oxidative stress, which rescue from Zn-induced changes in the expression of monoamine transporter and nigrostriatal dopaminergic neurodegeneration.

  8. Glial cell biology in the Great Lakes region.

    Science.gov (United States)

    Feinstein, Douglas L; Skoff, Robert P

    2016-03-31

    We report on the tenth bi-annual Great Lakes Glial meeting, held in Traverse City, Michigan, USA, September 27-29 2015. The GLG meeting is a small conference that focuses on current research in glial cell biology. The array of functions that glial cells (astrocytes, microglia, oligodendrocytes, Schwann cells) play in health and disease is constantly increasing. Despite this diversity, GLG meetings bring together scientists with common interests, leading to a better understanding of these cells. This year's meeting included two keynote speakers who presented talks on the regulation of CNS myelination and the consequences of stress on Schwann cell biology. Twenty-two other talks were presented along with two poster sessions. Sessions covered recent findings in the areas of microglial and astrocyte activation; age-dependent changes to glial cells, Schwann cell development and pathology, and the role of stem cells in glioma and neural regeneration.

  9. Evaluation of C.L.I.N.D.E. as potent peripheral-type benzodiazepine receptor tracer in a rat model of micro-glial activation

    Energy Technology Data Exchange (ETDEWEB)

    Arlicot, N.; Guilloteau, D.; Chalon, S. [Institut National de la Sante et de la Recherche Medicale (INSERM), U619, 37 - Tours (France); Universite Francois Rabelais de Tours, 37 (France); Katsifis, A.; Mattner, F. [ANSTO, Sydney (Australia)

    2008-02-15

    The peripheral-type benzodiazepine receptors (P.B.R.) are localized in mitochondria of glial cells and are very low expressed in normal brain. Their expression rises after micro-glial activation consecutive to brain injury. Accordingly, P.B.R. are potential targets to evaluate neuro inflammatory changes in a variety of C.N.S. disorders. To date no effective tool is available to explore P.B.R. by SPECT. We characterized here 6-chloro-2-(4 iodophenyl)-3-(N,N-diethyl)-imidazo[1,2-a]pyridine- 3-acetamide, C.L.I.N.D.E., in a rat model of excitotoxic lesion. Excitotoxicity was induced in male Wistar rats by unilateral intra striatal injection of different amounts of quinolinic acid (Q.A.: 75, 150 or 300 nmol). One week later, 2 groups of rats (n = 5-6/group) were i.v. injected with [{sup 125}I]-C.L.I.N.D.E. (0.4 MBq), one group being pre-injected with P.K.11195 (5 mg/kg). Brains were removed 30 min after tracer injection and the radioactivity of cerebral areas measured. Complementary ex vivo autoradiography and immunohistochemical studies using O.X.-42 were performed on brain sections In the control group, [{sup 125}I]-C.L.I.N.D.E. binding was significantly higher ( p < 0.001) in lesioned than that in intact side (striatum: 0.552 {+-} 0.109 vs. 0.123 {+-} 0.012% I.D./g tissue; cortex: 0.385 {+-} 0.126 vs. 0.131 {+-} 0.007% with 300 nmol Q.A.). This binding disappeared in rats pretreated with P.K.11195 ( p < 0.001), showing specific binding of C.L.I.N.D.E. to P.B.R.. Ex vivo autoradiography and immunohistochemistry were consistent with this, revealing a spatial correspondence between radioactivity signal and activated micro-glia. Regression analysis yielded a significant correlation ( p < 0.001) between the ligand binding and the dose of Q.A.. These results demonstrate that C.L.I.N.D.E. is suitable for P.B.R. in vivo SPECT imaging to explore their involvement in neuro degenerative disorders associated with micro-glial activation. (authors)

  10. Microglia in Alzheimer’s Disease: Activated, Dysfunctional or Degenerative

    Directory of Open Access Journals (Sweden)

    Victoria Navarro

    2018-05-01

    Full Text Available Microglial activation has been considered a crucial player in the pathological process of multiple human neurodegenerative diseases. In some of these pathologies, such as Amyotrophic Lateral Sclerosis or Multiple Sclerosis, the immune system and microglial cells (as part of the cerebral immunity play a central role. In other degenerative processes, such as Alzheimer’s disease (AD, the role of microglia is far to be elucidated. In this “mini-review” article, we briefly highlight our recent data comparing the microglial response between amyloidogenic transgenic models, such as APP/PS1 and AD patients. Since the AD pathology could display regional heterogeneity, we focus our work at the hippocampal formation. In APP based models a prominent microglial response is triggered around amyloid-beta (Aβ plaques. These strongly activated microglial cells could drive the AD pathology and, in consequence, could be implicated in the neurodegenerative process observed in models. On the contrary, the microglial response in human samples is, at least, partial or attenuated. This patent difference could simply reflect the lower and probably slower Aβ production observed in human hippocampal samples, in comparison with models, or could reflect the consequence of a chronic long-standing microglial activation. Beside this differential response, we also observed microglial degeneration in Braak V–VI individuals that, indeed, could compromise their normal role of surveying the brain environment and respond to the damage. This microglial degeneration, particularly relevant at the dentate gyrus, might be mediated by the accumulation of toxic soluble phospho-tau species. The consequences of this probably deficient immunological protection, observed in AD patients, are unknown.

  11. Inhibition of the kynurenine pathway protects against reactive microglial-associated reductions in the complexity of primary cortical neurons.

    Science.gov (United States)

    O'Farrell, Katherine; Fagan, Eimear; Connor, Thomas J; Harkin, Andrew

    2017-09-05

    Brain glia possess the rate limiting enzyme indoleamine 2, 3-dioxygenase (IDO) which catalyses the conversion of tryptophan to kynurenine. Microglia also express kynurenine monooxygenase (KMO) and kynureninase (KYNU) which lead to the production of the free radical producing metabolites, 3-hydroxykynurenine and 3-hydroxyanthranillic acid respectively and subsequently production of the NMDA receptor agonist quinolinic acid. The aim of this study was to examine the effect of IFNγ-stimulated kynurenine pathway (KP) induction in microglia on neurite outgrowth and complexity, and to determine whether alterations could be abrogated using pharmacological inhibitors of the KP. BV-2 microglia were treated with IFNγ (5ng/ml) for 24h and conditioned media (CM) was placed on primary cortical neurons 3 days in vitro (DIV) for 48h. Neurons were fixed and neurite outgrowth and complexity was assessed using fluorescent immunocytochemistry followed by Sholl analysis. Results show increased mRNA expression of IDO, KMO and KYNU, and increased concentrations of tryptophan, kynurenine, and 3-hydroxykynurenine in the CM of IFNγ-stimulated BV-2 microglia. The IFNγ-stimulated BV-2 microglial CM reduced neurite outgrowth and complexity with reductions in various parameters of neurite outgrowth prevented when BV-2 microglia were pre-treated with either the IDO inhibitor, 1-methyltryptophan (1-MT) (L) (0.5mM; 30min), the KMO inhibitor, Ro 61-8048 (1μM; 30min), the synthetic glucocorticoid, dexamethasone (1μM; 2h) -which suppresses IFNγ-induced IDO - and the N-methyl-D-aspartate (NMDA) receptor antagonist, MK801 (0.1μM; 30min). Overall this study indicates that inhibition of the KP in microglia may be targeted to protect against reactive microglial-associated neuronal atrophy. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Microglial Phagocytosis and Its Regulation: A Therapeutic Target in Parkinson’s Disease?

    Directory of Open Access Journals (Sweden)

    Elzbieta Janda

    2018-04-01

    Full Text Available The role of phagocytosis in the neuroprotective function of microglia has been appreciated for a long time, but only more recently a dysregulation of this process has been recognized in Parkinson’s disease (PD. Indeed, microglia play several critical roles in central nervous system (CNS, such as clearance of dying neurons and pathogens as well as immunomodulation, and to fulfill these complex tasks they engage distinct phenotypes. Regulation of phenotypic plasticity and phagocytosis in microglia can be impaired by defects in molecular machinery regulating critical homeostatic mechanisms, including autophagy. Here, we briefly summarize current knowledge on molecular mechanisms of microglia phagocytosis, and the neuro-pathological role of microglia in PD. Then we focus more in detail on the possible functional role of microglial phagocytosis in the pathogenesis and progression of PD. Evidence in support of either a beneficial or deleterious role of phagocytosis in dopaminergic degeneration is reported. Altered expression of target-recognizing receptors and lysosomal receptor CD68, as well as the emerging determinant role of α-synuclein (α-SYN in phagocytic function is discussed. We finally discuss the rationale to consider phagocytic processes as a therapeutic target to prevent or slow down dopaminergic degeneration.

  13. Microglial Scavenger Receptors and Their Roles in the Pathogenesis of Alzheimer's Disease

    Directory of Open Access Journals (Sweden)

    Kim Wilkinson

    2012-01-01

    Full Text Available Alzheimer’s disease (AD is increasing in prevalence with the aging population. Deposition of amyloid-β (Aβ in the brain of AD patients is a hallmark of the disease and is associated with increased microglial numbers and activation state. The interaction of microglia with Aβ appears to play a dichotomous role in AD pathogenesis. On one hand, microglia can phagocytose and clear Aβ, but binding of microglia to Aβ also increases their ability to produce inflammatory cytokines, chemokines, and neurotoxic reactive oxygen species (ROS. Scavenger receptors, a group of evolutionally conserved proteins expressed on the surface of microglia act as receptors for Aβ. Of particular interest are SCARA-1 (scavenger receptor A-1, CD36, and RAGE (receptor for advanced glycation end products. SCARA-1 appears to be involved in the clearance of Aβ, while CD36 and RAGE are involved in activation of microglia by Aβ. In this review, we discuss the roles of various scavenger receptors in the interaction of microglia with Aβ and propose that these receptors play complementary, nonredundant functions in the development of AD pathology. We also discuss potential therapeutic applications for these receptors in AD.

  14. A homologous form of human interleukin 16 is implicated in microglia recruitment following nervous system injury in leech Hirudo medicinalis.

    Science.gov (United States)

    Croq, Françoise; Vizioli, Jacopo; Tuzova, Marina; Tahtouh, Muriel; Sautiere, Pierre-Eric; Van Camp, Christelle; Salzet, Michel; Cruikshank, William W; Pestel, Joel; Lefebvre, Christophe

    2010-11-01

    In contrast to mammals, the medicinal leech Hirudo medicinalis can completely repair its central nervous system (CNS) after injury. This invertebrate model offers unique opportunities to study the molecular and cellular basis of the CNS repair processes. When the leech CNS is injured, microglial cells migrate and accumulate at the site of lesion, a phenomenon known to be essential for the usual sprouting of injured axons. In the present study, we demonstrate that a new molecule, designated HmIL-16, having functional homologies with human interleukin-16 (IL-16), has chemotactic activity on leech microglial cells as observed using a gradient of human IL-16. Preincubation of microglial cells either with an anti-human IL-16 antibody or with anti-HmIL-16 antibody significantly reduced microglia migration induced by leech-conditioned medium. Functional homology was demonstrated further by the ability of HmIL-16 to promote human CD4+ T cell migration which was inhibited by antibody against human IL-16, an IL-16 antagonist peptide or soluble CD4. Immunohistochemistry of leech CNS indicates that HmIL-16 protein present in the neurons is rapidly transported and stored along the axonal processes to promote the recruitment of microglial cells to the injured axons. To our knowledge, this is the first identification of a functional interleukin-16 homologue in invertebrate CNS. The ability of HmIL-16 to recruit microglial cells to sites of CNS injury suggests a role for HmIL-16 in the crosstalk between neurons and microglia in the leech CNS repair.

  15. Enhanced microglial clearance of myelin debris in T cell-infiltrated central nervous system

    DEFF Research Database (Denmark)

    Nielsen, Helle Hvilsted; Ladeby, Rune; Fenger, Christina

    2009-01-01

    Acute multiple sclerosis lesions are characterized by accumulation of T cells and macrophages, destruction of myelin and oligodendrocytes, and axonal damage. There is, however, limited information on neuroimmune interactions distal to sites of axonal damage in the T cell-infiltrated central nervo...

  16. Isolation of murine postnatal brain microglia for phenotypic characterization using magnetic cell separation technology.

    Science.gov (United States)

    Harms, Ashley S; Tansey, Malú G

    2013-01-01

    To shorten the time between brain harvesting and microglia isolation, and characterization, we utilized the MACS(®) neural dissociation kit followed by OctoMACS(®) CD11b magnetic bead isolation technique to positively select for brain microglia expressing the pan-microglial marker CD11b, a key subunit of the membrane attack complex (MAC). This protocol yields a viable and highly pure (>95%) microglial population of approximately 500,000 cells per pup that is amenable for in vitro characterization within hours or days after being harvested from brain tissue. Primary microglia from C57Bl/6 mice were plated for next-day analyses of morphology and cellular markers by immunocytochemistry or for analysis of gene expression under resting or LPS-stimulated conditions. The ease of isolation enables investigators to perform molecular and cellular analyses without having to wait 1-2 weeks to isolate microglia by conventional methods involving mechanical agitation to dislodge these from astrocyte beds.

  17. The leech nervous system: a valuable model to study the microglia involvement in regenerative processes.

    Science.gov (United States)

    Le Marrec-Croq, Françoise; Drago, Francesco; Vizioli, Jacopo; Sautière, Pierre-Eric; Lefebvre, Christophe

    2013-01-01

    Microglia are intrinsic components of the central nervous system (CNS). During pathologies in mammals, inflammatory processes implicate the resident microglia and the infiltration of blood cells including macrophages. Functions of microglia appear to be complex as they exhibit both neuroprotective and neurotoxic effects during neuropathological conditions in vivo and in vitro. The medicinal leech Hirudo medicinalis is a well-known model in neurobiology due to its ability to naturally repair its CNS following injury. Considering the low infiltration of blood cells in this process, the leech CNS is studied to specify the activation mechanisms of only resident microglial cells. The microglia recruitment is known to be essential for the usual sprouting of injured axons and does not require any other glial cells. The present review will describe the questions which are addressed to understand the nerve repair. They will discuss the implication of leech factors in the microglial accumulation, the identification of nerve cells producing these molecules, and the study of different microglial subsets. Those questions aim to better understand the mechanisms of microglial cell recruitment and their crosstalk with damaged neurons. The study of this dialog is necessary to elucidate the balance of the inflammation leading to the leech CNS repair.

  18. The Leech Nervous System: A Valuable Model to Study the Microglia Involvement in Regenerative Processes

    Directory of Open Access Journals (Sweden)

    Françoise Le Marrec-Croq

    2013-01-01

    Full Text Available Microglia are intrinsic components of the central nervous system (CNS. During pathologies in mammals, inflammatory processes implicate the resident microglia and the infiltration of blood cells including macrophages. Functions of microglia appear to be complex as they exhibit both neuroprotective and neurotoxic effects during neuropathological conditions in vivo and in vitro. The medicinal leech Hirudo medicinalis is a well-known model in neurobiology due to its ability to naturally repair its CNS following injury. Considering the low infiltration of blood cells in this process, the leech CNS is studied to specify the activation mechanisms of only resident microglial cells. The microglia recruitment is known to be essential for the usual sprouting of injured axons and does not require any other glial cells. The present review will describe the questions which are addressed to understand the nerve repair. They will discuss the implication of leech factors in the microglial accumulation, the identification of nerve cells producing these molecules, and the study of different microglial subsets. Those questions aim to better understand the mechanisms of microglial cell recruitment and their crosstalk with damaged neurons. The study of this dialog is necessary to elucidate the balance of the inflammation leading to the leech CNS repair.

  19. Parvalbumin-expressing ependymal cells in rostral lateral ventricle wall adhesions contribute to aging-related ventricle stenosis in mice.

    Science.gov (United States)

    Filice, Federica; Celio, Marco R; Babalian, Alexandre; Blum, Walter; Szabolcsi, Viktoria

    2017-10-15

    Aging-associated ependymal-cell pathologies can manifest as ventricular gliosis, ventricle enlargement, or ventricle stenosis. Ventricle stenosis and fusion of the lateral ventricle (LV) walls is associated with a massive decline of the proliferative capacities of the stem cell niche in the affected subventricular zone (SVZ) in aging mice. We examined the brains of adult C57BL/6 mice and found that ependymal cells located in the adhesions of the medial and lateral walls of the rostral LVs upregulated parvalbumin (PV) and displayed reactive phenotype, similarly to injury-reactive ependymal cells. However, PV+ ependymal cells in the LV-wall adhesions, unlike injury-reactive ones, did not express glial fibrillary acidic protein. S100B+/PV+ ependymal cells found in younger mice diminished in the LV-wall adhesions throughout aging. We found that periventricular PV-immunofluorescence showed positive correlation to the grade of LV stenosis in nonaged mice (wall adhesions and LV stenosis was significantly lower in mid-aged (>10-month-old) PV-knock out (PV-KO) mice. This suggests an involvement of PV+ ependymal cells in aging-associated ventricle stenosis. Additionally, we observed a time-shift in microglial activation in the LV-wall adhesions between age-grouped PV-KO and wild-type mice, suggesting a delay in microglial activation when PV is absent from ependymal cells. Our findings implicate that compromised ependymal cells of the adhering ependymal layers upregulate PV and display phenotype shift to "reactive" ependymal cells in aging-related ventricle stenosis; moreover, they also contribute to the progression of LV-wall fusion associated with a decline of the affected SVZ-stem cell niche in aged mice. © 2017 Wiley Periodicals, Inc.

  20. The in vitro GcMAF effects on endocannabinoid system transcriptionomics, receptor formation, and cell activity of autism-derived macrophages

    OpenAIRE

    Siniscalco, Dario; Bradstreet, James Jeffrey; Cirillo, Alessandra; Antonucci, Nicola

    2014-01-01

    Background Immune system dysregulation is well-recognized in autism and thought to be part of the etiology of this disorder. The endocannabinoid system is a key regulator of the immune system via the cannabinoid receptor type 2 (CB2R) which is highly expressed on macrophages and microglial cells. We have previously published significant differences in peripheral blood mononuclear cell CB2R gene expression in the autism population. The use of the Gc protein-derived Macrophage Activating Factor...

  1. Virus Infections on Prion Diseased Mice Exacerbate Inflammatory Microglial Response

    Science.gov (United States)

    Lins, Nara; Mourão, Luiz; Trévia, Nonata; Passos, Aline; Farias, José Augusto; Assunção, Jarila; Bento-Torres, João; Consentino Kronka Sosthenes, Marcia; Diniz, José Antonio Picanço; Vasconcelos, Pedro Fernando da Costa

    2016-01-01

    We investigated possible interaction between an arbovirus infection and the ME7 induced mice prion disease. C57BL/6, females, 6-week-old, were submitted to a bilateral intrahippocampal injection of ME7 prion strain (ME7) or normal brain homogenate (NBH). After injections, animals were organized into two groups: NBH (n = 26) and ME7 (n = 29). At 15th week after injections (wpi), animals were challenged intranasally with a suspension of Piry arbovirus 0.001% or with NBH. Behavioral changes in ME7 animals appeared in burrowing activity at 14 wpi. Hyperactivity on open field test, errors on rod bridge, and time reduction in inverted screen were detected at 15th, 19th, and 20th wpi respectively. Burrowing was more sensitive to earlier hippocampus dysfunction. However, Piry-infection did not significantly affect the already ongoing burrowing decline in the ME7-treated mice. After behavioral tests, brains were processed for IBA1, protease-resistant form of PrP, and Piry virus antigens. Although virus infection in isolation did not change the number of microglia in CA1, virus infection in prion diseased mice (at 17th wpi) induced changes in number and morphology of microglia in a laminar-dependent way. We suggest that virus infection exacerbates microglial inflammatory response to a greater degree in prion-infected mice, and this is not necessarily correlated with hippocampal-dependent behavioral deficits. PMID:28003864

  2. In vivo changes in microglial activation and amyloid deposits in brain regions with hypometabolism in Alzheimer's disease

    Energy Technology Data Exchange (ETDEWEB)

    Yokokura, Masamichi; Mori, Norio; Yoshihara, Yujiro; Wakuda, Tomoyasu; Takebayashi, Kiyokazu; Iwata, Yasuhide; Nakamura, Kazuhiko [Hamamatsu University School of Medicine, Department of Psychiatry and Neurology, Hamamatsu (Japan); Yagi, Shunsuke; Ouchi, Yasuomi [Hamamatsu University School of Medicine, Laboratory of Human Imaging Research, Molecular Imaging Frontier Research Center, Hamamatsu (Japan); Yoshikawa, Etsuji [Hamamatsu Photonics K.K., Central Research Laboratory, Hamamatsu (Japan); Kikuchi, Mitsuru [Kanazawa University, Department of Psychiatry and Neurobiology, Graduate School of Medical Science, Kanazawa (Japan); Sugihara, Genichi; Suda, Shiro; Tsuchiya, Kenji J.; Suzuki, Katsuaki [Hamamatsu University School of Medicine, Research Center for Child Mental Development, Hamamatsu (Japan); Ueki, Takatoshi [Hamamatsu University School of Medicine, Department of Anatomy, Hamamatsu (Japan)

    2011-02-15

    Amyloid {beta} protein (A{beta}) is known as a pathological substance in Alzheimer's disease (AD) and is assumed to coexist with a degree of activated microglia in the brain. However, it remains unclear whether these two events occur in parallel with characteristic hypometabolism in AD in vivo. The purpose of the present study was to clarify the in vivo relationship between A{beta} accumulation and neuroinflammation in those specific brain regions in early AD. Eleven nootropic drug-naive AD patients underwent a series of positron emission tomography (PET) measurements with [{sup 11}C](R)PK11195, [{sup 11}C]PIB and [{sup 18}F]FDG and a battery of cognitive tests within the same day. The binding potentials (BPs) of [{sup 11}C](R)PK11195 were directly compared with those of [{sup 11}C]PIB in the brain regions with reduced glucose metabolism. BPs of [{sup 11}C](R)PK11195 and [{sup 11}C]PIB were significantly higher in the parietotemporal regions of AD patients than in ten healthy controls. In AD patients, there was a negative correlation between dementia score and [{sup 11}C](R)PK11195 BPs, but not [{sup 11}C]PIB, in the limbic, precuneus and prefrontal regions. Direct comparisons showed a significant negative correlation between [{sup 11}C](R)PK11195 and [{sup 11}C]PIB BPs in the posterior cingulate cortex (PCC) (p < 0.05, corrected) that manifested the most severe reduction in [{sup 18}F]FDG uptake. A lack of coupling between microglial activation and amyloid deposits may indicate that A{beta} accumulation shown by [{sup 11}C]PIB is not always the primary cause of microglial activation, but rather the negative correlation present in the PCC suggests that microglia can show higher activation during the production of A{beta} in early AD. (orig.)

  3. Effectors of Th1 and Th17 cells act on astrocytes and augment their neuroinflammatory properties.

    Science.gov (United States)

    Prajeeth, Chittappen K; Kronisch, Julius; Khorooshi, Reza; Knier, Benjamin; Toft-Hansen, Henrik; Gudi, Viktoria; Floess, Stefan; Huehn, Jochen; Owens, Trevor; Korn, Thomas; Stangel, Martin

    2017-10-16

    Autoreactive Th1 and Th17 cells are believed to mediate the pathology of multiple sclerosis in the central nervous system (CNS). Their interaction with microglia and astrocytes in the CNS is crucial for the regulation of the neuroinflammation. Previously, we have shown that only Th1 but not Th17 effectors activate microglia. However, it is not clear which cells are targets of Th17 effectors in the CNS. To understand the effects driven by Th17 cells in the CNS, we induced experimental autoimmune encephalomyelitis in wild-type mice and CD4 + T cell-specific integrin α4-deficient mice where trafficking of Th1 cells into the CNS was affected. We compared microglial and astrocyte response in the brain and spinal cord of these mice. We further treated astrocytes with supernatants from highly pure Th1 and Th17 cultures and assessed the messenger RNA expression of neurotrophic factors, cytokines and chemokines, using real-time PCR. Data obtained was analyzed using the Kruskal-Wallis test. We observed in α4-deficient mice weak microglial activation but comparable astrogliosis to that of wild-type mice in the regions of the brain populated with Th17 infiltrates, suggesting that Th17 cells target astrocytes and not microglia. In vitro, in response to supernatants from Th1 and Th17 cultures, astrocytes showed altered expression of neurotrophic factors, pro-inflammatory cytokines and chemokines. Furthermore, increased expression of chemokines in Th1- and Th17-treated astrocytes enhanced recruitment of microglia and transendothelial migration of Th17 cells in vitro. Our results demonstrate the delicate interaction between T cell subsets and glial cells and how they communicate to mediate their effects. Effectors of Th1 act on both microglia and astrocytes whereas Th17 effectors preferentially target astrocytes to promote neuroinflammation.

  4. Microglia change from a reactive to an age-like phenotype with the time in culture

    Science.gov (United States)

    Caldeira, Cláudia; Oliveira, Ana F.; Cunha, Carolina; Vaz, Ana R.; Falcão, Ana S.; Fernandes, Adelaide; Brites, Dora

    2014-01-01

    Age-related neurodegenerative diseases have been associated with chronic neuroinflammation and microglia activation. However, cumulative evidence supports that inflammation only occurs at an early stage once microglia change the endogenous characteristics with aging and switch to irresponsive/senescent and dystrophic phenotypes with disease progression. Thus, it will be important to have the means to assess the role of reactive and aged microglia when studying advanced brain neurodegeneration processes and age-associated related disorders. Yet, most studies are done with microglia from neonates since there are no adequate means to isolate degenerating microglia for experimentation. Indeed, only a few studies report microglia isolation from aged animals, using either short-term cultures or high concentrations of mitogens in the medium, which trigger microglia reactivity. The purpose of this study was to develop an experimental process to naturally age microglia after isolation from neonatal mice and to characterize the cultured cells at 2 days in vitro (DIV), 10 DIV, and 16 DIV. We found that 2 DIV (young) microglia had predominant amoeboid morphology and markers of stressed/reactive phenotype. In contrast, 16 DIV (aged) microglia evidenced ramified morphology and increased matrix metalloproteinase (MMP)-2 activation, as well as reduced MMP-9, glutamate release and nuclear factor kappa-B activation, in parallel with decreased expression of Toll-like receptor (TLR)-2 and TLR-4, capacity to migrate and phagocytose. These findings together with the reduced expression of microRNA (miR)-124, and miR-155, decreased autophagy, enhanced senescence associated beta-galactosidase activity and elevated miR-146a expression, are suggestive that 16 DIV cells mainly correspond to irresponsive/senescent microglia. Data indicate that the model represent an opportunity to understand and control microglial aging, as well as to explore strategies to recover microglia surveillance

  5. Etiogenic factors present in the cerebrospinal fluid from amyotrophic lateral sclerosis patients induce predominantly pro-inflammatory responses in microglia.

    Science.gov (United States)

    Mishra, Pooja-Shree; Vijayalakshmi, K; Nalini, A; Sathyaprabha, T N; Kramer, B W; Alladi, Phalguni Anand; Raju, T R

    2017-12-16

    Microglial cell-associated neuroinflammation is considered as a potential contributor to the pathophysiology of sporadic amyotrophic lateral sclerosis. However, the specific role of microglia in the disease pathogenesis remains to be elucidated. We studied the activation profiles of the microglial cultures exposed to the cerebrospinal fluid from these patients which recapitulates the neurodegeneration seen in sporadic amyotrophic lateral sclerosis. This was done by investigating the morphological and functional changes including the expression levels of prostaglandin E2 (PGE2), cyclooxygenase-2 (COX-2), TNF-α, IL-6, IFN-γ, IL-10, inducible nitric oxide synthase (iNOS), arginase, and trophic factors. We also studied the effect of chitotriosidase, the inflammatory protein found upregulated in the cerebrospinal fluid from amyotrophic lateral sclerosis patients, on these cultures. We report that the cerebrospinal fluid from amyotrophic lateral sclerosis patients could induce an early and potent response in the form of microglial activation, skewed primarily towards a pro-inflammatory profile. It was seen in the form of upregulation of the pro-inflammatory cytokines and factors including IL-6, TNF-α, iNOS, COX-2, and PGE2. Concomitantly, a downregulation of beneficial trophic factors and anti-inflammatory markers including VEGF, glial cell line-derived neurotrophic factor, and IFN-γ was seen. In addition, chitotriosidase-1 appeared to act specifically via the microglial cells. Our findings demonstrate that the cerebrospinal fluid from amyotrophic lateral sclerosis patients holds enough cues to induce microglial inflammatory processes as an early event, which may contribute to the neurodegeneration seen in the sporadic amyotrophic lateral sclerosis. These findings highlight the dynamic role of microglial cells in the pathogenesis of the disease, thus suggesting the need for a multidimensional and temporally guarded therapeutic approach targeting the inflammatory

  6. Genetic variation in the cellular response of Daphnia magna (Crustacea: Cladocera) to its bacterial parasite.

    Science.gov (United States)

    Auld, Stuart K J R; Scholefield, Jennifer A; Little, Tom J

    2010-11-07

    Linking measures of immune function with infection, and ultimately, host and parasite fitness is a major goal in the field of ecological immunology. In this study, we tested for the presence and timing of a cellular immune response in the crustacean Daphnia magna following exposure to its sterilizing endoparasite Pasteuria ramosa. We found that D. magna possesses two cell types circulating in the haemolymph: a spherical one, which we call a granulocyte and an irregular-shaped amoeboid cell first described by Metchnikoff over 125 years ago. Daphnia magna mounts a strong cellular response (of the amoeboid cells) just a few hours after parasite exposure. We further tested for, and found, considerable genetic variation for the magnitude of this cellular response. These data fostered a heuristic model of resistance in this naturally coevolving host-parasite interaction. Specifically, the strongest cellular responses were found in the most susceptible hosts, indicating resistance is not always borne from a response that destroys invading parasites, but rather stems from mechanisms that prevent their initial entry. Thus, D. magna may have a two-stage defence--a genetically determined barrier to parasite establishment and a cellular response once establishment has begun.

  7. The spider effect: morphological and orienting classification of microglia in response to stimuli in vivo.

    Directory of Open Access Journals (Sweden)

    Rahul A Jonas

    Full Text Available The different morphological stages of microglial activation have not yet been described in detail. We transected the olfactory bulb of rats and examined the activation of the microglial system histologically. Six stages of bidirectional microglial activation (A and deactivation (R were observed: from stage 1A to 6A, the cell body size increased, the cell process number decreased, and the cell processes retracted and thickened, orienting toward the direction of the injury site; until stage 6A, when all processes disappeared. In contrast, in deactivation stages 6R to 1R, the microglia returned to the original site exhibiting a stepwise retransformation to the original morphology. Thin highly branched processes re-formed in stage 1R, similar to those in stage 1A. This reverse transformation mirrored the forward transformation except in stages 6R to 1R: cells showed multiple nuclei which were slowly absorbed. Our findings support a morphologically defined stepwise activation and deactivation of microglia cells.

  8. Population control of resident and immigrant microglia by mitosis and apoptosis

    DEFF Research Database (Denmark)

    Wirenfeldt, Martin; Dissing-Olesen, Lasse; Babcock, Alicia

    2007-01-01

    microglia often occurred in clusters, some having recently incorporated bromodeoxyuridine, showing that proliferation had occurred. Annexin V labeling and staining for activated caspase-3 and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling showed that apoptotic mechanisms participate...... in dissolution of the microglial response. Using bone marrow chimeric mice, we found that the lesion-induced proliferative capacity of resident microglia superseded that of immigrant microglia, whereas lesion-induced kinetics of apoptosis were comparable. Microglial numbers and responses were severely reduced...... in bone marrow chimeric mice. These results broaden our understanding of the microglial response to neural damage by demonstrating that simultaneously occurring mitosis and apoptosis regulate expansion and reduction of both resident and immigrant microglial cell populations....

  9. microRNA-21a-5p/PDCD4 axis regulates mesenchymal stem cell-induced neuroprotection in acute glaucoma.

    Science.gov (United States)

    Su, Wenru; Li, Zuohong; Jia, Y; Zhu, Yingting; Cai, Wenjia; Wan, Peixing; Zhang, Yingying; Zheng, Song Guo; Zhuo, Yehong

    2017-08-01

    Mesenchymal stem cells (MSCs) have been demonstrated to have promising therapeutic benefits for a variety of neurological diseases; however, the underlying mechanisms are poorly understood. Here, we showed that intravitreal infusion of MSCs promoted retinal ganglion cell (RGC) survival in a mouse model of acute glaucoma, with significant inhibition of microglial activation, production of TNF-α, IL-1β, and reactive oxygen species, as well as caspase-8 and caspase-3 activation. In vitro, MSCs inhibited both caspase-8-mediated RGC apoptosis and microglial activation, partly via the action of stanniocalcin 1 (STC1). Furthermore, we found that microRNA-21a-5p (miR-21) and its target, PDCD4, were essential for STC1 production and the neuroprotective property of MSCs in vitro and in vivo. Importantly, miR-21 overexpression or PDCD4 knockdown augmented MSC-mediated neuroprotective effects on acute glaucoma. These data highlight a previously unrecognized neuroprotective mechanism by which the miR-21/PDCD4 axis induces MSCs to secrete STC1 and other factors that exert neuroprotective effects. Therefore, modulating the miR-21/PDCD4 axis might be a promising strategy for clinical treatment of acute glaucoma and other neurological diseases. © The Author (2017). Published by Oxford University Press on behalf of Journal of Molecular Cell Biology, IBCB, SIBS, CAS. All rights reserved.

  10. Geographic variability in amoeboid protists and other microbial groups in the water column of the lower Hudson River Estuary (New York, USA)

    Science.gov (United States)

    Juhl, Andrew R.; Anderson, O. Roger

    2014-12-01

    In comparison to other groups of planktonic microorganisms, relatively little is known about the role of amoeboid protists (amebas) in planktonic ecosystems. This study describes the first geographic survey of the abundance and biomass of amebas in an estuarine water column. Samples collected in the lower Hudson River Estuary were used to investigate relationships between ameba abundance and biomass and hydrographic variables (temperature, salinity, and turbidity), water depth (surface and near bottom), distance from mid-channel to shore, phytoplankton biomass (chlorophyll fluorescence) and the occurrence of other heterotrophic microbial groups (heterotrophic bacteria, nanoflagellates, and ciliates) in the plankton. Although salinity increased significantly towards the mouth of the estuary, there were no significant differences in the abundance or biomass of any microbial group in surface samples collected at three stations separated by 44 km along the estuary's mid-channel. Peak biomass values for all microbial groups were found at the station closest to shore, however, cross-channel trends in microbial abundance and biomass were not statistically significant. Although ameba abundance and biomass in most samples were low compared to other microbial groups, clear patterns in ameba distribution were nevertheless found. Unlike other microbial groups examined, ameba numbers and biomass greatly increased in near bottom water compared to surface samples. Ameba abundance and biomass (in surface samples) were also strongly related to increasing turbidity. The different relationships of ameba abundance and biomass with turbidity suggest a rising contribution of large amebas in microbial communities of the Hudson estuary when turbidity increases. These results, emphasizing the importance of particle concentration as attachment and feeding surfaces for amebas, will help identify the environmental conditions when amebas are most likely to contribute significantly to estuarine

  11. Microglial-derived miRNA let-7 and HMGB1 contribute to ethanol-induced neurotoxicity via TLR7.

    Science.gov (United States)

    Coleman, Leon G; Zou, Jian; Crews, Fulton T

    2017-01-25

    Toll-like receptor (TLR) signaling is emerging as an important component of neurodegeneration. TLR7 senses viral RNA and certain endogenous miRNAs to initiate innate immune responses leading to neurodegeneration. Alcoholism is associated with hippocampal degeneration, with preclinical studies linking ethanol-induced neurodegeneration with central innate immune induction and TLR activation. The endogenous miRNA let-7b binds TLR7 to cause neurodegeneration. TLR7 and other immune markers were assessed in postmortem human hippocampal tissue that was obtained from the New South Wales Tissue Bank. Rat hippocampal-entorhinal cortex (HEC) slice culture was used to assess specific effects of ethanol on TLR7, let-7b, and microvesicles. We report here that hippocampal tissue from postmortem human alcoholic brains shows increased expression of TLR7 and increased microglial activation. Using HEC slice culture, we found that ethanol induces TLR7 and let-7b expression. Ethanol caused TLR7-associated neuroimmune gene induction and initiated the release let-7b in microvesicles (MVs), enhancing TLR7-mediated neurotoxicity. Further, ethanol increased let-7b binding to the danger signaling molecule high mobility group box-1 (HMGB1) in MVs, while reducing let-7 binding to classical chaperone protein argonaute (Ago2). Flow cytometric analysis of MVs from HEC media and analysis of MVs from brain cell culture lines found that microglia were the primary source of let-7b and HMGB1-containing MVs. Our results identify that ethanol induces neuroimmune pathology involving the release of let-7b/HMGB1 complexes in microglia-derived microvesicles. This contributes to hippocampal neurodegeneration and may play a role in the pathology of alcoholism.

  12. Inhibition of Allograft Inflammatory Factor-1 in Dendritic Cells Restrains CD4+ T Cell Effector Responses and Induces CD25+Foxp3+ T Regulatory Subsets

    Directory of Open Access Journals (Sweden)

    Diana M. Elizondo

    2017-11-01

    Full Text Available Allograft inflammatory factor-1 (AIF1 is a cytoplasmic scaffold protein shown to influence immune responses in macrophages and microglial cells. The protein contains Ca2+ binding EF-hand and PDZ interaction domains important for mediating intracellular signaling complexes. This study now reports that AIF1 is expressed in CD11c+ dendritic cells (DC and silencing of expression restrains induction of antigen-specific CD4+ T cell effector responses. AIF1 knockdown in murine DC resulted in impaired T cell proliferation and skewed polarization away from T helper type 1 and 17 fates. In turn, there was a parallel expansion of IL-10-producing and CD25+Foxp3+ T regulatory subsets. These studies are the first to demonstrate that AIF1 expression in DC serves as a potent governor of cognate T cell responses and presents a novel target for engineering tolerogenic DC-based immunotherapies.

  13. Targeted Delivery of siRNA to Macrophages for Anti-inflammatory Treatment

    OpenAIRE

    Kim, Sang-Soo; Ye, Chunting; Kumar, Priti; Chiu, Isaac; Subramanya, Sandesh; Wu, Haoquan; Shankar, Premlata; Manjunath, N

    2010-01-01

    Inflammation mediated by tumor necrosis factor-α (TNF-α) and the associated neuronal apoptosis characterizes a number of neurologic disorders. Macrophages and microglial cells are believed to be the major source of TNF-α in the central nervous system (CNS). Here, we show that suppression of TNF-α by targeted delivery of small interfering RNA (siRNA) to macrophage/microglial cells dramatically reduces lipopolysaccharide (LPS)-induced neuroinflammation and neuronal apoptosis in vivo. Because ma...

  14. Involvement of Phosphatidylinositol 3-Kinase-Mediated Up-Regulation of IκBα in Anti-Inflammatory Effect of Gemfibrozil in Microglia1

    OpenAIRE

    Jana, Malabendu; Jana, Arundhati; Liu, Xiaojuan; Ghosh, Sankar; Pahan, Kalipada

    2007-01-01

    The present study underlines the importance of PI3K in mediating the anti-inflammatory effect of gemfibrozil, a prescribed lipid-lowering drug for humans, in mouse microglia. Gemfibrozil inhibited LPS-induced expression of inducible NO synthase (iNOS) and proinflammatory cytokines in mouse BV-2 microglial cells and primary microglia. By overexpressing wild-type and dominant-negative constructs of peroxisome proliferator-activated receptor-α (PPAR-α) in microglial cells and isolating primary m...

  15. Chemokines in neuron-glial cell interaction and pathogenesis of neuropathic pain.

    Science.gov (United States)

    Zhang, Zhi-Jun; Jiang, Bao-Chun; Gao, Yong-Jing

    2017-09-01

    Neuropathic pain resulting from damage or dysfunction of the nervous system is a highly debilitating chronic pain state and is often resistant to currently available treatments. It has become clear that neuroinflammation, mainly mediated by proinflammatory cytokines and chemokines, plays an important role in the establishment and maintenance of neuropathic pain. Chemokines were originally identified as regulators of peripheral immune cell trafficking and were also expressed in neurons and glial cells in the central nervous system. In recent years, accumulating studies have revealed the expression, distribution and function of chemokines in the spinal cord under chronic pain conditions. In this review, we provide evidence showing that several chemokines are upregulated after peripheral nerve injury and contribute to the pathogenesis of neuropathic pain via different forms of neuron-glia interaction in the spinal cord. First, chemokine CX3CL1 is expressed in primary afferents and spinal neurons and induces microglial activation via its microglial receptor CX3CR1 (neuron-to-microglia signaling). Second, CCL2 and CXCL1 are expressed in spinal astrocytes and act on CCR2 and CXCR2 in spinal neurons to increase excitatory synaptic transmission (astrocyte-to-neuron signaling). Third, we recently identified that CXCL13 is highly upregulated in spinal neurons after spinal nerve ligation and induces spinal astrocyte activation via receptor CXCR5 (neuron-to-astrocyte signaling). Strategies that target chemokine-mediated neuron-glia interactions may lead to novel therapies for the treatment of neuropathic pain.

  16. Histamine induces microglia activation and dopaminergic neuronal toxicity via H1 receptor activation.

    Science.gov (United States)

    Rocha, Sandra M; Saraiva, Tatiana; Cristóvão, Ana C; Ferreira, Raquel; Santos, Tiago; Esteves, Marta; Saraiva, Cláudia; Je, Goun; Cortes, Luísa; Valero, Jorge; Alves, Gilberto; Klibanov, Alexander; Kim, Yoon-Seong; Bernardino, Liliana

    2016-06-04

    Histamine is an amine widely known as a peripheral inflammatory mediator and as a neurotransmitter in the central nervous system. Recently, it has been suggested that histamine acts as an innate modulator of microglial activity. Herein, we aimed to disclose the role of histamine in microglial phagocytic activity and reactive oxygen species (ROS) production and to explore the consequences of histamine-induced neuroinflammation in dopaminergic (DA) neuronal survival. The effect of histamine on phagocytosis was assessed both in vitro by using a murine N9 microglial cell line and primary microglial cell cultures and in vivo. Cells were exposed to IgG-opsonized latex beads or phosphatidylserine (PS) liposomes to evaluate Fcγ or PS receptor-mediated microglial phagocytosis, respectively. ROS production and protein levels of NADPH oxidases and Rac1 were assessed as a measure of oxidative stress. DA neuronal survival was evaluated in vivo by counting the number of tyrosine hydroxylase-positive neurons in the substantia nigra (SN) of mice. We found that histamine triggers microglial phagocytosis via histamine receptor 1 (H1R) activation and ROS production via H1R and H4R activation. By using apocynin, a broad NADPH oxidase (Nox) inhibitor, and Nox1 knockout mice, we found that the Nox1 signaling pathway is involved in both phagocytosis and ROS production induced by histamine in vitro. Interestingly, both apocynin and annexin V (used as inhibitor of PS-induced phagocytosis) fully abolished the DA neurotoxicity induced by the injection of histamine in the SN of adult mice in vivo. Blockade of H1R protected against histamine-induced Nox1 expression and death of DA neurons in vivo. Overall, our results highlight the relevance of histamine in the modulation of microglial activity that ultimately may interfere with neuronal survival in the context of Parkinson's disease (PD) and, eventually, other neurodegenerative diseases which are accompanied by microglia

  17. Myoferlin depletion in breast cancer cells promotes mesenchymal to epithelial shape change and stalls invasion.

    Directory of Open Access Journals (Sweden)

    Ruth Li

    Full Text Available Myoferlin (MYOF is a mammalian ferlin protein with homology to ancestral Fer-1, a nematode protein that regulates spermatic membrane fusion, which underlies the amoeboid-like movements of its sperm. Studies in muscle and endothelial cells have reported on the role of myoferlin in membrane repair, endocytosis, myoblast fusion, and the proper expression of various plasma membrane receptors. In this study, using an in vitro human breast cancer cell model, we demonstrate that myoferlin is abundantly expressed in invasive breast tumor cells. Depletion of MYOF using lentiviral-driven shRNA expression revealed that MDA-MB-231 cells reverted to an epithelial morphology, suggesting at least some features of mesenchymal to epithelial transition (MET. These observations were confirmed by the down-regulation of some mesenchymal cell markers (e.g., fibronectin and vimentin and coordinate up-regulation of the E-cadherin epithelial marker. Cell invasion assays using Boyden chambers showed that loss of MYOF led to a significant diminution in invasion through Matrigel or type I collagen, while cell migration was unaffected. PCR array and screening of serum-free culture supernatants from shRNA(MYOF transduced MDA-MB-231 cells indicated a significant reduction in the steady-state levels of several matrix metalloproteinases. These data when considered in toto suggest a novel role of MYOF in breast tumor cell invasion and a potential reversion to an epithelial phenotype upon loss of MYOF.

  18. Crosstalk between insulin-like growth factor-1 and angiotensin-II in dopaminergic neurons and glial cells: role in neuroinflammation and aging

    Science.gov (United States)

    Rodriguez-Perez, Ana I.; Borrajo, Ana; Diaz-Ruiz, Carmen; Garrido-Gil, Pablo; Labandeira-Garcia, Jose L.

    2016-01-01

    The local renin-angiotensin system (RAS) and insulin-like growth factor 1 (IGF-1) have been involved in longevity, neurodegeneration and aging-related dopaminergic degeneration. However, it is not known whether IGF-1 and angiotensin-II (AII) activate each other. In the present study, AII, via type 1 (AT1) receptors, exacerbated neuroinflammation and dopaminergic cell death. AII, via AT1 receptors, also increased the levels of IGF-1 and IGF-1 receptors in microglial cells. IGF-1 inhibited RAS activity in dopaminergic neurons and glial cells, and also inhibited the AII-induced increase in markers of the M1 microglial phenotype. Consistent with this, IGF-1 decreased dopaminergic neuron death induced by the neurotoxin MPP+ both in the presence and in the absence of glia. Intraventricular administration of AII to young rats induced a significant increase in IGF-1 expression in the nigral region. However, aged rats showed decreased levels of IGF-1 relative to young controls, even though RAS activity is known to be enhanced in aged animals. The study findings show that IGF-1 and the local RAS interact to inhibit or activate neuroinflammation (i.e. transition from the M1 to the M2 phenotype), oxidative stress and dopaminergic degeneration. The findings also show that this mechanism is impaired in aged animals. PMID:27167199

  19. The Plant-Derived Chalcone 2,2′,5′-Trihydroxychalcone Provides Neuroprotection against Toll-Like Receptor 4 Triggered Inflammation in Microglia

    Directory of Open Access Journals (Sweden)

    Manasi Jiwrajka

    2016-01-01

    Full Text Available Chalcones are plant metabolites with potential for therapeutic exploitation as antioxidant, anti-inflammatory, and antiproliferative agents. Here we explored the neuroprotective effects of 2,2′,5′-trihydroxychalcone (225THC, a potent antioxidant with radical-scavenging properties. 225THC was found to be a potent inhibitor of apoptosis in stimulated primary rat neuronal cultures. This was likely mediated by an anti-inflammatory effect on microglial cells since 225THC inhibited LPS-stimulated TNF-α and IL-6 secretion from primary rat microglia and modulated the cytokine/chemokine profile of BV2 microglial cells. Additionally, 225THC inhibited LPS-evoked inducible nitric oxide synthase expression but did not influence endogenous superoxide generation. Microglial flow cytometric analyses indicated the 225THC treatment induced a shift from an M1-like phenotype to a more downregulated microglial profile. Taken together these data suggest that the chalcone 2,2′,5′-trihydroxychalcone can modulate neuroinflammatory activation in brain-derived microglia and holds promise as a therapeutic in neuroinflammatory conditions.

  20. Feeding the beast: can microglia in the senescent brain be regulated by diet?

    Science.gov (United States)

    Johnson, Rodney W

    2015-01-01

    Microglial cells, resident macrophages in the central nervous system (CNS), are relatively quiescent but can respond to signals from the peripheral immune system and induce neuroinflammation. In aging, microglia tend to transition to the M1 pro-inflammatory state and become hypersensitive to messages emerging from immune-to-brain signaling pathways. Thus, whereas in younger individuals where microglia respond to signals from the peripheral immune system and induce a well-controlled neuroinflammatory response that is adaptive (e.g., when well controlled, fever and sickness behavior facilitate recovery from infection), in older individuals with an infection, microglia overreact and produce excessive levels of inflammatory cytokines causing behavioral pathology including cognitive dysfunction. Importantly, recent studies indicate a number of naturally occurring bioactive compounds present in certain foods have anti-inflammatory properties and are capable of mitigating brain microglial cells. These include, e.g., flavonoid and non-flavonoid compounds in fruits and vegetables, and n-3 polyunsaturated fatty acids (PUFA) in oily fish. Thus, dietary bioactives have potential to restore the population of microglial cells in the senescent brain to a more quiescent state. The pragmatic concept to constrain microglia through dietary intervention is significant because neuroinflammation and cognitive deficits are co-morbid factors in many chronic inflammatory diseases. Controlling microglial cell reactivity has important consequences for preserving adult neurogenesis, neuronal structure and function, and cognition. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Nitric oxide from inflammatory origin impairs neural stem cell proliferation by inhibiting epidermal growth factor receptor signaling

    Directory of Open Access Journals (Sweden)

    Bruno Pereira Carreira

    2014-10-01

    Full Text Available Neuroinflammation is characterized by activation of microglial cells, followed by production of nitric oxide (NO, which may have different outcomes on neurogenesis, favoring or inhibiting this process. In the present study, we investigated how the inflammatory mediator NO can affect proliferation of neural stem cells (NSC, and explored possible mechanisms underlying this effect. We investigated which mechanisms are involved in the regulation of NSC proliferation following treatment with an inflammatory stimulus (LPS plus IFN-γ, using a culture system of subventricular zone (SVZ-derived NSC mixed with microglia cells obtained from wild-type mice (iNOS+/+ or from iNOS knockout mice (iNOS-/-. We found an impairment of NSC cell proliferation in iNOS+/+ mixed cultures, which was not observed in iNOS-/- mixed cultures. Furthermore, the increased release of NO by activated iNOS+/+ microglial cells decreased the activation of the ERK/MAPK signaling pathway, which was concomitant with an enhanced nitration of the EGF receptor. Preventing nitrogen reactive species formation with MnTBAP, a scavenger of peroxynitrite, or using the peroxynitrite degradation catalyst FeTMPyP, cell proliferation and ERK signaling were restored to basal levels in iNOS+/+ mixed cultures. Moreover, exposure to the NO donor NOC-18 (100 µM, for 48 h, inhibited SVZ-derived NSC proliferation. Regarding the antiproliferative effect of NO, we found that NOC-18 caused the impairment of signaling through the ERK/MAPK pathway, which may be related to increased nitration of the EGF receptor in NSC. Using MnTBAP nitration was prevented, maintaining ERK signaling, rescuing NSC proliferation. We show that NO from inflammatory origin leads to a decreased function of the EGF receptor, which compromised proliferation of NSC. We also demonstrated that NO-mediated nitration of the EGF receptor caused a decrease in its phosphorylation, thus preventing regular proliferation signaling through the

  2. Progranulin Gene Therapy Improves Lysosomal Dysfunction and Microglial Pathology Associated with Frontotemporal Dementia and Neuronal Ceroid Lipofuscinosis.

    Science.gov (United States)

    Arrant, Andrew E; Onyilo, Vincent C; Unger, Daniel E; Roberson, Erik D

    2018-02-28

    Loss-of-function mutations in progranulin, a lysosomal glycoprotein, cause neurodegenerative disease. Progranulin haploinsufficiency causes frontotemporal dementia (FTD) and complete progranulin deficiency causes CLN11 neuronal ceroid lipofuscinosis (NCL). Progranulin replacement is a rational therapeutic strategy for these disorders, but there are critical unresolved mechanistic questions about a progranulin gene therapy approach, including its potential to reverse existing pathology. Here, we address these issues using an AAV vector (AAV- Grn ) to deliver progranulin in Grn -/- mice (both male and female), which model aspects of NCL and FTD pathology, developing lysosomal dysfunction, lipofuscinosis, and microgliosis. We first tested whether AAV- Grn could improve preexisting pathology. Even with treatment after onset of pathology, AAV- Grn reduced lipofuscinosis in several brain regions of Grn -/- mice. AAV- Grn also reduced microgliosis in brain regions distant from the injection site. AAV-expressed progranulin was only detected in neurons, not in microglia, indicating that the microglial activation in progranulin deficiency can be improved by targeting neurons and thus may be driven at least in part by neuronal dysfunction. Even areas with sparse transduction and almost undetectable progranulin showed improvement, indicating that low-level replacement may be sufficiently effective. The beneficial effects of AAV- Grn did not require progranulin binding to sortilin. Finally, we tested whether AAV- Grn improved lysosomal function. AAV-derived progranulin was delivered to the lysosome, ameliorated the accumulation of LAMP-1 in Grn -/- mice, and corrected abnormal cathepsin D activity. These data shed light on progranulin biology and support progranulin-boosting therapies for NCL and FTD due to GRN mutations. SIGNIFICANCE STATEMENT Heterozygous loss-of-function progranulin ( GRN ) mutations cause frontotemporal dementia (FTD) and homozygous mutations cause neuronal

  3. Cofilin Knockdown Attenuates Hemorrhagic Brain Injury-induced Oxidative Stress and Microglial Activation in Mice.

    Science.gov (United States)

    Alhadidi, Qasim; Nash, Kevin M; Alaqel, Saleh; Sayeed, Muhammad Shahdaat Bin; Shah, Zahoor A

    2018-05-08

    Intracerebral hemorrhage (ICH) resulting from the rupture of the blood vessels in the brain is associated with significantly higher mortality and morbidity. Clinical studies focused on alleviating the primary injury, hematoma formation and expansion, were largely ineffective, suggesting that secondary injury-induced inflammation and the formation of reactive species also contribute to the overall injury process. In this study, we explored the effects of cofilin knockdown in a mouse model of ICH. Animals given stereotaxic injections of cofilin siRNA, 72-h prior to induction of ICH by collagenase injection within the area of siRNA administration showed significantly decreased cofilin expression levels and lower hemorrhage volume and edema, and the animals performed significantly better in neurobehavioral tasks i.e., rotarod, grip strength and neurologic deficit scores. Cofilin siRNA knocked-down mice had reduced ICH-induced DNA fragmentation, blood-brain barrier disruption and microglial activation, with a concomitant increase in astrocyte activation. Increased expression of pro-survival proteins and decreased markers of oxidative stress were also observed in cofilin siRNA-treated mice possibly due to the reduced levels of cofilin. Our results suggest that cofilin plays a major role in ICH-induced secondary injury, and could become a potential therapeutic target. Copyright © 2018 IBRO. Published by Elsevier Ltd. All rights reserved.

  4. Microglial KCa3.1 Channels as a Potential Therapeutic Target for Alzheimer’s Disease

    Directory of Open Access Journals (Sweden)

    Izumi Maezawa

    2012-01-01

    Full Text Available There exists an urgent need for new target discovery to treat Alzheimer’s disease (AD; however, recent clinical trials based on anti-Aβ and anti-inflammatory strategies have yielded disappointing results. To expedite new drug discovery, we propose reposition targets which have been previously pursued by both industry and academia for indications other than AD. One such target is the calcium-activated potassium channel KCa3.1 (KCNN4, which in the brain is primarily expressed in microglia and is significantly upregulated when microglia are activated. We here review the existing evidence supporting that KCa3.1 inhibition could block microglial neurotoxicity without affecting their neuroprotective phagocytosis activity and without being broadly immunosuppressive. The anti-inflammatory and neuroprotective effects of KCa3.1 blockade would be suitable for treating AD as well as cerebrovascular and traumatic brain injuries, two well-known risk factors contributing to the dementia in AD patients presenting with mixed pathologies. Importantly, the pharmacokinetics and pharmacodynamics of several KCa3.1 blockers are well known, and a KCa3.1 blocker has been proven safe in clinical trials. It is therefore promising to reposition old or new KCa3.1 blockers for AD preclinical and clinical trials.

  5. α-Asarone Attenuates Cognitive Deficit in a Pilocarpine-Induced Status Epilepticus Rat Model via a Decrease in the Nuclear Factor-κB Activation and Reduction in Microglia Neuroinflammation

    Directory of Open Access Journals (Sweden)

    Hui-juan Liu

    2017-12-01

    Full Text Available BackgroundTemporal lobe epilepsy (TLE is one of the most drug-resistant types of epilepsy with about 80% of TLE patients falling into this category. Increasing evidence suggests that neuroinflammation, which has a critical role in the epileptogenesis of TLE, is associated with microglial activation. Therefore, agents that act toward the alleviation in microglial activation and the attenuation of neuroinflammation are promising candidates to treat TLE. α-Asarone is a major active ingredient of the Acori Graminei Rhizoma used in Traditional Chinese Medicine, which has been used to improve various disease conditions including stroke and convulsions. In addition, an increasing number of studies suggested that α-asarone can attenuate microglia-mediated neuroinflammation. Thus, we hypothesized that α-asarone is a promising neuroprotective agent for the treatment of the TLE.MethodsThe present study evaluated the therapeutic effects of α-asarone on microglia-mediated neuroinflammation and neuroprotection in vitro and in vivo, using an untreated control group, a status epilepticus (SE-induced group, and an SE-induced α-asarone pretreated group. A pilocarpine-induced rat model of TLE was established to investigate the neuroprotective effects of α-asarone in vivo. For the in vitro study, lipopolysaccharide (LPS-stimulated primary cultured microglial cells were used.ResultsThe results indicated that the brain microglial activation in the rats of the SE rat model led to important learning and memory deficit. Preventive treatment with α-asarone restrained microglial activation and reduced learning and memory deficit. In the in vitro studies, α-asarone significantly suppressed proinflammatory cytokine production in primary cultured microglial cells and attenuated the LPS-stimulated neuroinflammatory responses. Our mechanistic study revealed that α-asarone inhibited inflammatory processes by regulation the transcription levels of kappa-B, by blocking

  6. Regulation of microglia activity by glaucocalyxin-A: attenuation of lipopolysaccharide-stimulated neuroinflammation through NF-κB and p38 MAPK signaling pathways.

    Directory of Open Access Journals (Sweden)

    Byung-Wook Kim

    Full Text Available Microglial cells are the resident macrophages and intrinsic arm of the central nervous system innate immune defense. Microglial cells become activated in response to injury, infection, environmental toxins, and other stimuli that threaten neuronal survival. Therefore, regulating microglial activation may have therapeutic benefits that lead to alleviating the progression of inflammatory-mediated neurodegeneration. In the present study, we investigated the effect of glaucocalyxin A (GLA isolated from Rabdosia japonica on the production of pro-inflammatory mediators in lipopolysaccharide (LPS-stimulated primary microglia and BV-2 cells. GLA significantly inhibited LPS-induced production of nitric oxide and reversed the morphological changes in primary microglia. Further, GLA suppressed expression of inducible nitric oxide synthase and cyclooxygenase-2 dose-dependently at the mRNA and protein levels. The production of proinflammatory cytokines such as tumor necrosis factor-α, interleukin-1β (IL-1β, and IL-6 were inhibited by suppressing their transcriptional activity. Furthermore, GLA suppressed nuclear factor-κB activation by blocking degradation of IκB-α and inhibited the induction of lipocalin-2 expression in LPS-stimulated BV-2 cells. Mechanistic study revealed that the inhibitory effects of GLA were accompanied by blocking the p38 mitogen activated protein kinase signaling pathway in activated microglia. In conclusion, given that microglial activation contributes to the pathogenesis of neurodegenerative diseases, GLA could be developed as a potential therapeutic agent for treating microglia-mediated neuroinflammatory diseases.

  7. Glucose pathways adaptation supports acquisition of activated microglia phenotype.

    Science.gov (United States)

    Gimeno-Bayón, J; López-López, A; Rodríguez, M J; Mahy, N

    2014-06-01

    With its capacity to survey the environment and phagocyte debris, microglia assume a diversity of phenotypes to respond specifically through neurotrophic and toxic effects. Although these roles are well accepted, the underlying energetic mechanisms associated with microglial activation remain largely unclear. This study investigates microglia metabolic adaptation to ATP, NADPH, H(+) , and reactive oxygen species production. To this end, in vitro studies were performed with BV-2 cells before and after activation with lipopolysaccharide + interferon-γ. Nitric oxide (NO) was measured as a marker of cell activation. Our results show that microglial activation triggers a metabolic reprogramming based on an increased glucose uptake and a strengthening of anaerobic glycolysis, as well as of the pentose pathway oxidative branch, while retaining the mitochondrial activity. Based on this energy commitment, microglial defense capacity increases rapidly as well as ribose-5-phosphate and nucleic acid formation for gene transcription, essential to ensure the newly acquired functions demanded by central nervous system signaling. We also review the role of NO in this microglial energy commitment that positions cytotoxic microglia within the energetics of the astrocyte-neuron lactate shuttle. Copyright © 2014 Wiley Periodicals, Inc.

  8. Anti-Neuroinflammatory Effects of Houttuynia cordata Extract on LPS ...

    African Journals Online (AJOL)

    lipopolysaccharide (LPS)-stimulated BV-2 microglial cells, and its anti-oxidant properties. ... Keywords: Houttuynia cordata, DPPH radicals, antioxidant, neuroinflammation, BV-2 cells, iNOS, ..... extracts on anaphylactic reaction and mast cell.

  9. Microglia and Aging: The Role of the TREM2–DAP12 and CX3CL1-CX3CR1 Axes

    Directory of Open Access Journals (Sweden)

    Carmen Mecca

    2018-01-01

    Full Text Available Depending on the species, microglial cells represent 5–20% of glial cells in the adult brain. As the innate immune effector of the brain, microglia are involved in several functions: regulation of inflammation, synaptic connectivity, programmed cell death, wiring and circuitry formation, phagocytosis of cell debris, and synaptic pruning and sculpting of postnatal neural circuits. Moreover, microglia contribute to some neurodevelopmental disorders such as Nasu-Hakola disease (NHD, and to aged-associated neurodegenerative diseases, such as Alzheimer’s disease (AD, Parkinson’s disease (PD, and others. There is evidence that human and rodent microglia may become senescent. This event determines alterations in the microglia activation status, associated with a chronic inflammation phenotype and with the loss of neuroprotective functions that lead to a greater susceptibility to the neurodegenerative diseases of aging. In the central nervous system (CNS, Triggering Receptor Expressed on Myeloid Cells 2-DNAX activation protein 12 (TREM2-DAP12 is a signaling complex expressed exclusively in microglia. As a microglial surface receptor, TREM2 interacts with DAP12 to initiate signal transduction pathways that promote microglial cell activation, phagocytosis, and microglial cell survival. Defective TREM2-DAP12 functions play a central role in the pathogenesis of several diseases. The CX3CL1 (fractalkine-CX3CR1 signaling represents the most important communication channel between neurons and microglia. The expression of CX3CL1 in neurons and of its receptor CX3CR1 in microglia determines a specific interaction, playing fundamental roles in the regulation of the maturation and function of these cells. Here, we review the role of the TREM2-DAP12 and CX3CL1-CX3CR1 axes in aged microglia and the involvement of these pathways in physiological CNS aging and in age-associated neurodegenerative diseases.

  10. Microglial Phenotype and Adaptation

    NARCIS (Netherlands)

    Eggen, B. J. L.; Raj, D.; Hanisch, U-K.; Boddeke, H. W. G. M.

    Microglia are the prime innate immune cells of the central nervous system. They can transit from a (so-called) resting state under homeostatic conditions towards a pro-inflammatory activation state upon homeostatic disturbances. Under neurodegenerative conditions, microglia have been largely

  11. Evidence for an amoeba-like infectious stage of ichthyophonus sp. and description of a circulating blood stage: a probable mechanism for dispersal within the fish host

    Science.gov (United States)

    Kocan, Richard; LaPatra, Scott; Hershberger, Paul

    2013-01-01

    Small amoeboid cells, believed to be the infectious stage of Ichthyophonus sp., were observed in the bolus (stomach contents) and tunica propria (stomach wall) of Pacific staghorn sculpins and rainbow trout shortly after they ingested Ichthyophonus sp.–infected tissues. By 24–48 hr post-exposure (PE) the parasite morphed from the classically reported multinucleate thick walled schizonts to 2 distinct cell types, i.e., a larger multinucleate amoeboid cell surrounded by a narrow translucent zone and a smaller spherical cell surrounded by a “halo” and resembling a small schizont. Both cell types also appeared in the tunica propria, indicating that they had recently penetrated the columnar epithelium of the stomach. No Ichthyophonus sp. pseudo-hyphae (“germination tubes”) were observed in the bolus or penetrating the stomach wall. Simultaneously, Ichthyophonus sp. was isolated in vitro from aortic blood, which was consistently positive from 6 to 144 hr PE, then only intermittently for the next 4 wk. Small PAS-positive cells observed in blood cultures grew into colonies consisting of non-septate tubules (pseudo-hyphae) terminating in multinucleated knob-like apices similar to those seen in organ explant cultures. Organ explants were culture positive every day; however, typical Ichthyophonus sp. schizonts were not observed histologically until 20–25 days PE. From 20 to 60 days PE, schizont diameter increased from ≤25 μm to ≥82 μm. Based on the data presented herein, we are confident that we have resolved the life cycle of Ichthyophonus sp. within the piscivorous host.

  12. Evidence for an amoeba-like infectious stage of Ichthyophonus sp. and description of a circulating blood stage: a probable mechanism for dispersal within the fish host.

    Science.gov (United States)

    Kocan, Richard; LaPatra, Scott; Hershberger, Paul

    2013-04-01

    Small amoeboid cells, believed to be the infectious stage of Ichthyophonus sp., were observed in the bolus (stomach contents) and tunica propria (stomach wall) of Pacific staghorn sculpins and rainbow trout shortly after they ingested Ichthyophonus sp.-infected tissues. By 24-48 hr post-exposure (PE) the parasite morphed from the classically reported multinucleate thick walled schizonts to 2 distinct cell types, i.e., a larger multinucleate amoeboid cell surrounded by a narrow translucent zone and a smaller spherical cell surrounded by a "halo" and resembling a small schizont. Both cell types also appeared in the tunica propria, indicating that they had recently penetrated the columnar epithelium of the stomach. No Ichthyophonus sp. pseudo-hyphae ("germination tubes") were observed in the bolus or penetrating the stomach wall. Simultaneously, Ichthyophonus sp. was isolated in vitro from aortic blood, which was consistently positive from 6 to 144 hr PE, then only intermittently for the next 4 wk. Small PAS-positive cells observed in blood cultures grew into colonies consisting of non-septate tubules (pseudo-hyphae) terminating in multinucleated knob-like apices similar to those seen in organ explant cultures. Organ explants were culture positive every day; however, typical Ichthyophonus sp. schizonts were not observed histologically until 20-25 days PE. From 20 to 60 days PE, schizont diameter increased from ≤ 25 μm to ≥ 82 μm. Based on the data presented herein, we are confident that we have resolved the life cycle of Ichthyophonus sp. within the piscivorous host.

  13. TAM receptors affect adult brain neurogenesis by negative regulation of microglial cell activation.

    Science.gov (United States)

    Ji, Rui; Tian, Shifu; Lu, Helen J; Lu, Qingjun; Zheng, Yan; Wang, Xiaomin; Ding, Jixiang; Li, Qiutang; Lu, Qingxian

    2013-12-15

    TAM tyrosine kinases play multiple functional roles, including regulation of the target genes important in homeostatic regulation of cytokine receptors or TLR-mediated signal transduction pathways. In this study, we show that TAM receptors affect adult hippocampal neurogenesis and loss of TAM receptors impairs hippocampal neurogenesis, largely attributed to exaggerated inflammatory responses by microglia characterized by increased MAPK and NF-κB activation and elevated production of proinflammatory cytokines that are detrimental to neuron stem cell proliferation and neuronal differentiation. Injection of LPS causes even more severe inhibition of BrdU incorporation in the Tyro3(-/-)Axl(-/-)Mertk(-/-) triple-knockout (TKO) brains, consistent with the LPS-elicited enhanced expression of proinflammatory mediators, for example, IL-1β, IL-6, TNF-α, and inducible NO synthase, and this effect is antagonized by coinjection of the anti-inflammatory drug indomethacin in wild-type but not TKO brains. Conditioned medium from TKO microglia cultures inhibits neuron stem cell proliferation and neuronal differentiation. IL-6 knockout in Axl(-/-)Mertk(-/-) double-knockout mice overcomes the inflammatory inhibition of neurogenesis, suggesting that IL-6 is a major downstream neurotoxic mediator under homeostatic regulation by TAM receptors in microglia. Additionally, autonomous trophic function of the TAM receptors on the proliferating neuronal progenitors may also promote progenitor differentiation into immature neurons.

  14. Fetal microglial in vitro phenotype depends on prior in vivo inflammation

    Directory of Open Access Journals (Sweden)

    Mingju eCao

    2015-08-01

    Full Text Available Objective. Neuroinflammation in utero may result in life-long neurological disabilities. The molecular mechanisms whereby microglia contribute to this response remain incompletely understood. Methods. Lipopolysaccharide (LPS or saline were administered intravenously to non-anesthetized chronically instrumented near-term fetal sheep to model fetal inflammation in vivo. Microglia were then isolated from in vivo LPS and saline (naïve exposed animals. To mimic the second hit of neuroinflammation, these microglia were then re-exposed to LPS in vitro. Cytokine responses were measured in vivo and subsequently in vitro in the primary microglia cultures derived from these animals. We sequenced the whole transcriptome of naïve and second hit microglia and profiled their genetic expression to define molecular pathways disrupted during neuroinflammation.Results. In vivo LPS exposure resulted in IL-6 increase in fetal plasma 3 h post LPS exposure. Even though not histologically apparent, microglia acquired a pro-inflammatory phenotype in vivo that was sustained and amplified in vitro upon second hit LPS exposure as measured by IL-1β response in vitro and RNAseq analyses. While NFKB and Jak-Stat inflammatory pathways were up regulated in naïve microglia, heme oxygenase 1 (HMOX1 and Fructose-1,6-bisphosphatase (FBP genes were uniquely differentially expressed in the second hit microglia. Microglial calreticulin/LRP genes implicated in microglia-neuronal communication relevant for the neuronal development were up regulated in second hit microglia.Discussion. We identified a unique HMOX1down and FBPup phenotype of microglia exposed to the double-hit suggesting interplay of inflammatory and metabolic pathways as a memory of prior inflammatory insult. These findings suggest new therapeutic targets for early postnatal intervention to prevent brain injury.

  15. Dominant Expression of DCLK1 in Human Pancreatic Cancer Stem Cells Accelerates Tumor Invasion and Metastasis.

    Directory of Open Access Journals (Sweden)

    Hiromitsu Ito

    Full Text Available Patients with pancreatic cancer typically develop tumor invasion and metastasis in the early stage. These malignant behaviors might be originated from cancer stem cells (CSCs, but the responsible target is less known about invisible CSCs especially for invasion and metastasis. We previously examined the proteasome activity of CSCs and constructed a real-time visualization system for human pancreatic CSCs. In the present study, we found that CSCs were highly metastatic and dominantly localized at the invading tumor margins in a liver metastasis model. Microarray and siRNA screening assays showed that doublecortin-like kinase 1 (DCLK1 was predominantly expressed with histone modification in pancreatic CSCs with invasive and metastatic potential. Overexpression of DCLK1 led to amoeboid morphology, which promotes the migration of pancreatic cancer cells. Knockdown of DCLK1 profoundly suppressed in vivo liver metastasis of pancreatic CSCs. Clinically, DCLK1 was overexpressed in the metastatic tumors in patients with pancreatic cancer. Our studies revealed that DCLK1 is essential for the invasive and metastatic properties of CSCs and may be a promising epigenetic and therapeutic target in human pancreatic cancer.

  16. Imaging of glial cell morphology, SOD1 distribution and elemental composition in the brainstem and hippocampus of the ALS hSOD1G93A rat.

    Science.gov (United States)

    Stamenković, Stefan; Dučić, Tanja; Stamenković, Vera; Kranz, Alexander; Andjus, Pavle R

    2017-08-15

    Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder affecting motor and cognitive domains of the CNS. Mutations in the Cu,Zn-superoxide dismutase (SOD1) cause 20% of familial ALS and provoke formation of intracellular aggregates and copper and zinc unbinding, leading to glial activation and neurodegeneration. Therefore, we investigated glial cell morphology, intracellular SOD1 distribution, and elemental composition in the brainstem and hippocampus of the hSOD1 G93A transgenic rat model of ALS. Immunostaining for astrocytes, microglia and SOD1 revealed glial proliferation and progressive tissue accumulation of SOD1 in both brain regions of ALS rats starting already at the presymptomatic stage. Glial cell morphology analysis in the brainstem of ALS rats revealed astrocyte activation occurring before disease symptoms onset, followed by activation of microglia. Hippocampal ALS astrocytes exhibited an identical reactive profile, while microglial morphology was unchanged. Additionally, ALS brainstem astrocytes demonstrated progressive SOD1 accumulation in the cell body and processes, while microglial SOD1 levels were reduced and its distribution limited to distal cell processes. In the hippocampus both glial cell types exhibited SOD1 accumulation in the cell body. X-ray fluorescence imaging revealed decreased P and increased Ca, Cl, K, Ni, Cu and Zn in the brainstem, and higher levels of Cl, Ni and Cu, but lower levels of Zn in the hippocampus of symptomatic ALS rats. These results bring new insights into the glial response during disease development and progression in motor as well as in non-motor CNS structures, and indicate disturbed tissue elemental homeostasis as a prominent hallmark of disease pathology. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

  17. Unicellular eukaryotes as models in cell and molecular biology: critical appraisal of their past and future value.

    Science.gov (United States)

    Simon, Martin; Plattner, Helmut

    2014-01-01

    Unicellular eukaryotes have been appreciated as model systems for the analysis of crucial questions in cell and molecular biology. This includes Dictyostelium (chemotaxis, amoeboid movement, phagocytosis), Tetrahymena (telomere structure, telomerase function), Paramecium (variant surface antigens, exocytosis, phagocytosis cycle) or both ciliates (ciliary beat regulation, surface pattern formation), Chlamydomonas (flagellar biogenesis and beat), and yeast (S. cerevisiae) for innumerable aspects. Nowadays many problems may be tackled with "higher" eukaryotic/metazoan cells for which full genomic information as well as domain databases, etc., were available long before protozoa. Established molecular tools, commercial antibodies, and established pharmacology are additional advantages available for higher eukaryotic cells. Moreover, an increasing number of inherited genetic disturbances in humans have become elucidated and can serve as new models. Among lower eukaryotes, yeast will remain a standard model because of its peculiarities, including its reduced genome and availability in the haploid form. But do protists still have a future as models? This touches not only the basic understanding of biology but also practical aspects of research, such as fund raising. As we try to scrutinize, due to specific advantages some protozoa should and will remain favorable models for analyzing novel genes or specific aspects of cell structure and function. Outstanding examples are epigenetic phenomena-a field of rising interest. © 2014 Elsevier Inc. All rights reserved.

  18. Stroke and the Cell Therapy Saga: Towards a Safe, Swift and Efficient Utilization of cells.

    Science.gov (United States)

    Kubis, Nathalie

    2017-01-01

    The first clinical trials of cell therapy in stroke were first published in the 2000s and consisted of neural stems cells transplanted via the intracerebral pathway. Since mesenchymal stem cells showed similar capacities to differentiate into neural cells and allowed autologous cell transplantation, they were then preferentially studied, including diabetes and hypertension. More recently, bone marrow derived mononuclear cells were successfully transplanted in stroke with no need of culture processing, and simple collection by density gradient centrifugation rendering them immediately ready for use. They improve post-stroke neurological deficit in rodents and clinical trials have shown the feasibility of intra-arterial or intravenous administration. The underlying mechanisms are not yet understood. We investigated the therapeutic potential of peripheral blood derived mononuclear cells (PB-MNC) harvested from diabetic patients and stimulated by ephrin-B2 (PB-MNC+). We showed that intravenously injected PB-MNC+ after cerebral ischemia reduced infarct volume at day 3, increased cell proliferation in the peri-infarct area and the subventricular zone, decreased microglial cell density, and upregulated TGF-β expression. At D14, microvessel density was increased and functional recovery enhanced, whereas plasma levels of BDNF were increased in treated mice. Ephrin-B2 induced phenotype switching of PB-MNC by upregulating genes controlling cell proliferation, inflammation and angiogenesis, as confirmed by adhesion and Matrigel assays. PB-MNC+ transplantation in stroke is a promising approach and should be investigated for the development of rapid, non-invasive bedside cell therapy strategies in stroke.(Presented at the 1944th Meeting, July 19, 2017).

  19. Modeling the Excess Cell Surface Stored in a Complex Morphology of Bleb-Like Protrusions.

    Directory of Open Access Journals (Sweden)

    Maryna Kapustina

    2016-03-01

    Full Text Available Cells transition from spread to rounded morphologies in diverse physiological contexts including mitosis and mesenchymal-to-amoeboid transitions. When these drastic shape changes occur rapidly, cell volume and surface area are approximately conserved. Consequently, the rounded cells are suddenly presented with a several-fold excess of cell surface whose area far exceeds that of a smooth sphere enclosing the cell volume. This excess is stored in a population of bleb-like protrusions (BLiPs, whose size distribution is shown by electron micrographs to be skewed. We introduce three complementary models of rounded cell morphologies with a prescribed excess surface area. A 2D Hamiltonian model provides a mechanistic description of how discrete attachment points between the cell surface and cortex together with surface bending energy can generate a morphology that satisfies a prescribed excess area and BLiP number density. A 3D random seed-and-growth model simulates efficient packing of BLiPs over a primary rounded shape, demonstrating a pathway for skewed BLiP size distributions that recapitulate 3D morphologies. Finally, a phase field model (2D and 3D posits energy-based constitutive laws for the cell membrane, nematic F-actin cortex, interior cytosol, and external aqueous medium. The cell surface is equipped with a spontaneous curvature function, a proxy for the cell surface-cortex couple, that is a priori unknown, which the model "learns" from the thin section transmission electron micrograph image (2D or the "seed and growth" model image (3D. Converged phase field simulations predict self-consistent amplitudes and spatial localization of pressure and stress throughout the cell for any posited stationary morphology target and cell compartment constitutive properties. The models form a general framework for future studies of cell morphological dynamics in a variety of biological contexts.

  20. Morphology, biology and phylogeny of Phalansterium arcticum sp. n. (Amoebozoa, Variosea), isolated from ancient Arctic permafrost.

    Science.gov (United States)

    Shmakova, Lyubov A; Karpov, Sergey A; Malavin, Stanislav A; Smirnov, Alexey V

    2018-04-01

    A new species, Phalansterium arcticum sp. n., was isolated from an 8580-year-old Arctic permafrost layer. This organism typically lives as a sedentary uniflagellated cell enclosed in a thin flexible mucilaginous sheath, but can form naked swimming cells and amoeboid cells with eruptive pseudopodia accompanied with the formation of short, filopodia-like projections. In an SSU rDNA phylogenetic tree, it robustly groups with other species of this genus. Along with a description of the species, we also add new details to the description of the cell division of Phalansterium and the feeding process in this organism. Copyright © 2018 Elsevier GmbH. All rights reserved.

  1. Progranulin regulates neurogenesis in the developing vertebrate retina.

    Science.gov (United States)

    Walsh, Caroline E; Hitchcock, Peter F

    2017-09-01

    We evaluated the expression and function of the microglia-specific growth factor, Progranulin-a (Pgrn-a) during developmental neurogenesis in the embryonic retina of zebrafish. At 24 hpf pgrn-a is expressed throughout the forebrain, but by 48 hpf pgrn-a is exclusively expressed by microglia and/or microglial precursors within the brain and retina. Knockdown of Pgrn-a does not alter the onset of neurogenic programs or increase cell death, however, in its absence, neurogenesis is significantly delayed-retinal progenitors fail to exit the cell cycle at the appropriate developmental time and postmitotic cells do not acquire markers of terminal differentiation, and microglial precursors do not colonize the retina. Given the link between Progranulin and cell cycle regulation in peripheral tissues and transformed cells, we analyzed cell cycle kinetics among retinal progenitors following Pgrn-a knockdown. Depleting Pgrn-a results in a significant lengthening of the cell cycle. These data suggest that Pgrn-a plays a dual role during nervous system development by governing the rate at which progenitors progress through the cell cycle and attracting microglial progenitors into the embryonic brain and retina. Collectively, these data show that Pgrn-a governs neurogenesis by regulating cell cycle kinetics and the transition from proliferation to cell cycle exit and differentiation. © 2017 The Authors. Developmental Neurobiology Published by Wiley Periodicals, Inc. Develop Neurobiol 77: 1114-1129, 2017. © 2017 The Authors. Developmental Neurobiology Published by Wiley Periodicals, Inc.

  2. Biological activities of Schottenol and Spinasterol, two natural phytosterols present in argan oil and in cactus pear seed oil, on murine miroglial BV2 cells

    Energy Technology Data Exchange (ETDEWEB)

    El Kharrassi, Youssef [Université de Bourgogne, Laboratoire Bio-PeroxIL, EA7270, Dijon F-21000 (France); Laboratoire de Biochimie et Neurosciences, Faculté des Sciences et Techniques, Université Hassan I, BP 577, 26000 Settat (Morocco); Samadi, Mohammad [LCPMC-A2, ICPM, Department of Chemistry, Université de Lorraine, Metz (France); Lopez, Tatiana [CRINSERM 866, Dijon (France); Nury, Thomas [Université de Bourgogne, Laboratoire Bio-PeroxIL, EA7270, Dijon F-21000 (France); El Kebbaj, Riad [Université de Bourgogne, Laboratoire Bio-PeroxIL, EA7270, Dijon F-21000 (France); Laboratoire de Biochimie et Neurosciences, Faculté des Sciences et Techniques, Université Hassan I, BP 577, 26000 Settat (Morocco); Andreoletti, Pierre; El Hajj, Hammam I. [Université de Bourgogne, Laboratoire Bio-PeroxIL, EA7270, Dijon F-21000 (France); Vamecq, Joseph [INSERM and HMNO, CBP, CHRU Lille, 59037 Lille (France); Moustaid, Khadija [Laboratoire de Biochimie et Neurosciences, Faculté des Sciences et Techniques, Université Hassan I, BP 577, 26000 Settat (Morocco); Latruffe, Norbert [Université de Bourgogne, Laboratoire Bio-PeroxIL, EA7270, Dijon F-21000 (France); El Kebbaj, M’Hammed Saïd [Laboratoire de recherche sur les Lipoprotéines et l’Athérosclérose, Faculté des Sciences Ben M’sik, Avenue Cdt Driss El Harti BP. 7955, Université Hassan II-Mohammedia-Casablanca (Morocco); Masson, David [CRINSERM 866, Dijon (France); and others

    2014-04-11

    Highlights: • Sterol composition in argan oil and in cactus seed oil. • Chemical synthesis of two sterols: Schottenol and Spinasterol. • Sterols from argan oil or from cactus seed oil show no toxicity on BV2 cells. • Schottenol and Spinasterol modulate the activation and the expression of two nuclear receptors, LXRα and LXRβ. - Abstract: The objective of this study was to evaluate the biological activities of the major phytosterols present in argan oil (AO) and in cactus seed oil (CSO) in BV2 microglial cells. Accordingly, we first determined the sterol composition of AO and CSO, showing the presence of Schottenol and Spinasterol as major sterols in AO. While in CSO, in addition to these two sterols, we found mainly another sterol, the Sitosterol. The chemical synthesis of Schottenol and Spinasterol was performed. Our results showed that these two phytosterols, as well as sterol extracts from AO or CSO, are not toxic to microglial BV2 cells. However, treatments by these phytosterols impact the mitochondrial membrane potential. Furthermore, both Schottenol and Spinasterol can modulate the gene expression of two nuclear receptors, liver X receptor (LXR)-α and LXRβ, their target genes ABCA1 and ABCG1. Nonetheless, only Schottenol exhibited a differential activation vis-à-vis the nuclear receptor LXRβ. Thus Schottenol and Spinasterol can be considered as new LXR agonists, which may play protective roles by the modulation of cholesterol metabolism.

  3. Biological activities of Schottenol and Spinasterol, two natural phytosterols present in argan oil and in cactus pear seed oil, on murine miroglial BV2 cells

    International Nuclear Information System (INIS)

    El Kharrassi, Youssef; Samadi, Mohammad; Lopez, Tatiana; Nury, Thomas; El Kebbaj, Riad; Andreoletti, Pierre; El Hajj, Hammam I.; Vamecq, Joseph; Moustaid, Khadija; Latruffe, Norbert; El Kebbaj, M’Hammed Saïd; Masson, David

    2014-01-01

    Highlights: • Sterol composition in argan oil and in cactus seed oil. • Chemical synthesis of two sterols: Schottenol and Spinasterol. • Sterols from argan oil or from cactus seed oil show no toxicity on BV2 cells. • Schottenol and Spinasterol modulate the activation and the expression of two nuclear receptors, LXRα and LXRβ. - Abstract: The objective of this study was to evaluate the biological activities of the major phytosterols present in argan oil (AO) and in cactus seed oil (CSO) in BV2 microglial cells. Accordingly, we first determined the sterol composition of AO and CSO, showing the presence of Schottenol and Spinasterol as major sterols in AO. While in CSO, in addition to these two sterols, we found mainly another sterol, the Sitosterol. The chemical synthesis of Schottenol and Spinasterol was performed. Our results showed that these two phytosterols, as well as sterol extracts from AO or CSO, are not toxic to microglial BV2 cells. However, treatments by these phytosterols impact the mitochondrial membrane potential. Furthermore, both Schottenol and Spinasterol can modulate the gene expression of two nuclear receptors, liver X receptor (LXR)-α and LXRβ, their target genes ABCA1 and ABCG1. Nonetheless, only Schottenol exhibited a differential activation vis-à-vis the nuclear receptor LXRβ. Thus Schottenol and Spinasterol can be considered as new LXR agonists, which may play protective roles by the modulation of cholesterol metabolism

  4. Histological Architecture Underlying Brain-Immune Cell-Cell Interactions and the Cerebral Response to Systemic Inflammation.

    Science.gov (United States)

    Shimada, Atsuyoshi; Hasegawa-Ishii, Sanae

    2017-01-01

    Although the brain is now known to actively interact with the immune system under non-inflammatory conditions, the site of cell-cell interactions between brain parenchymal cells and immune cells has been an open question until recently. Studies by our and other groups have indicated that brain structures such as the leptomeninges, choroid plexus stroma and epithelium, attachments of choroid plexus, vascular endothelial cells, cells of the perivascular space, circumventricular organs, and astrocytic endfeet construct the histological architecture that provides a location for intercellular interactions between bone marrow-derived myeloid lineage cells and brain parenchymal cells under non-inflammatory conditions. This architecture also functions as the interface between the brain and the immune system, through which systemic inflammation-induced molecular events can be relayed to the brain parenchyma at early stages of systemic inflammation during which the blood-brain barrier is relatively preserved. Although brain microglia are well known to be activated by systemic inflammation, the mechanism by which systemic inflammatory challenge and microglial activation are connected has not been well documented. Perturbed brain-immune interaction underlies a wide variety of neurological and psychiatric disorders including ischemic brain injury, status epilepticus, repeated social defeat, and neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. Proinflammatory status associated with cytokine imbalance is involved in autism spectrum disorders, schizophrenia, and depression. In this article, we propose a mechanism connecting systemic inflammation, brain-immune interface cells, and brain parenchymal cells and discuss the relevance of basic studies of the mechanism to neurological disorders with a special emphasis on sepsis-associated encephalopathy and preterm brain injury.

  5. Microglia in Glia-Neuron Co-cultures Exhibit Robust Phagocytic Activity Without Concomitant Inflammation or Cytotoxicity.

    Science.gov (United States)

    Adams, Alexandra C; Kyle, Michele; Beaman-Hall, Carol M; Monaco, Edward A; Cullen, Matthew; Vallano, Mary Lou

    2015-10-01

    A simple method to co-culture granule neurons and glia from a single brain region is described, and microglia activation profiles are assessed in response to naturally occurring neuronal apoptosis, excitotoxin-induced neuronal death, and lipopolysaccharide (LPS) addition. Using neonatal rat cerebellar cortex as a tissue source, glial proliferation is regulated by omission or addition of the mitotic inhibitor cytosine arabinoside (AraC). After 7-8 days in vitro, microglia in AraC(-) cultures are abundant and activated based on their amoeboid morphology, expressions of ED1 and Iba1, and ability to phagocytose polystyrene beads and the majority of neurons undergoing spontaneous apoptosis. Microglia and phagocytic activities are sparse in AraC(+) cultures. Following exposure to excitotoxic kainate concentrations, microglia in AraC(-) cultures phagocytose most dead neurons within 24 h without exacerbating neuronal loss or mounting a strong or sustained inflammatory response. LPS addition induces a robust inflammatory response, based on microglial expressions of TNF-α, COX-2 and iNOS proteins, and mRNAs, whereas these markers are essentially undetectable in control cultures. Thus, the functional effector state of microglia is primed for phagocytosis but not inflammation or cytotoxicity even after kainate exposure that triggers death in the majority of neurons. This model should prove useful in studying the progressive activation states of microglia and factors that promote their conversion to inflammatory and cytotoxic phenotypes.

  6. The effect of minocycline on the masticatory movements following the inferior alveolar nerve transection in freely moving rats

    Directory of Open Access Journals (Sweden)

    Mostafeezur Rahman

    2012-04-01

    Full Text Available Abstract Background To determine the effects of inferior alveolar nerve transection (IAN-X on masticatory movements in freely moving rats and to test if microglial cells in the trigeminal principal sensory nucleus (prV or motor nucleus (motV may be involved in modulation of mastication, the effects of microglial cell inhibitor minocycline (MC on masticatory jaw movements, microglia (Iba1 immunohistochemistry and the masticatory jaw movements and related masticatory muscle EMG activities were studied in IAN-X rats. Results The number of Iba1-immunoreactive (IR cells both in prV and motV was significantly larger in IAN-X rats compared with sham rats on day 3 after IAN-X. The intraperitoneal (i.p. administration of MC caused a significant reduction of the number of Iba1-IR cells both in prV and motV that was evident on day 14 after IAN-X. Furthermore, a significant reduction of the number of Iba1-IR cells could be observed in motV but not in prV after microinjection (m.i. of MC into the motV of IAN-X rats. The rats also exhibited a significant decrease in the head-withdrawal threshold on the side ipsilateral to the IAN-X compared to the threshold before IAN-X and it lasted to day 14. In addition, IAN-X markedly affected the ability to rat to carry out mastication. The number of complete masticatory sequences was significantly decreased. Furthermore, the total masticatory sequence time and food preparatory (PP period duration was significantly elongated in compared to sham rats. Although IAN-X significantly affected the total number of chewing cycles within the RC period of a masticatory sequence, it had no effect on the duration of the chewing cycles. On the other hand, systemic administration of MC (both i.p. and m.i. in IAN-X rats significantly improved decreased head-withdrawal threshold and the impaired masticatory jaw movements. Conclusions The present findings reveal that the strong modulation of masticatory jaw movements occurs following

  7. Characterizing newly repopulated microglia in the adult mouse: impacts on animal behavior, cell morphology, and neuroinflammation.

    Directory of Open Access Journals (Sweden)

    Monica R P Elmore

    Full Text Available Microglia are the primary immune cell in the brain and are postulated to play important roles outside of immunity. Administration of the dual colony-stimulating factor 1 receptor (CSF1R/c-Kit kinase inhibitor, PLX3397, to adult mice results in the elimination of ~99% of microglia, which remain eliminated for as long as treatment continues. Upon removal of the inhibitor, microglia rapidly repopulate the entire adult brain, stemming from a central nervous system (CNS resident progenitor cell. Using this method of microglial elimination and repopulation, the role of microglia in both healthy and diseased states can be explored. Here, we examine the responsiveness of newly repopulated microglia to an inflammatory stimulus, as well as determine the impact of these cells on behavior, cognition, and neuroinflammation. Two month-old wild-type mice were placed on either control or PLX3397 diet for 21 d to eliminate microglia. PLX3397 diet was then removed in a subset of animals to allow microglia to repopulate and behavioral testing conducted beginning at 14 d repopulation. Finally, inflammatory profiling of the microglia-repopulated brain in response to lipopolysaccharide (LPS; 0.25 mg/kg or phosphate buffered saline (PBS was determined 21 d after inhibitor removal using quantitative real time polymerase chain reaction (RT-PCR, as well as detailed analyses of microglial morphologies. We find mice with repopulated microglia to perform similarly to controls by measures of behavior, cognition, and motor function. Compared to control/resident microglia, repopulated microglia had larger cell bodies and less complex branching in their processes, which resolved over time after inhibitor removal. Inflammatory profiling revealed that the mRNA gene expression of repopulated microglia was similar to normal resident microglia and that these new cells appear functional and responsive to LPS. Overall, these data demonstrate that newly repopulated microglia function

  8. Mycobacterium tuberculosis-infected human monocytes down-regulate microglial MMP-2 secretion in CNS tuberculosis via TNFα, NFκB, p38 and caspase 8 dependent pathways

    Directory of Open Access Journals (Sweden)

    Elkington Paul T

    2011-05-01

    Full Text Available Abstract Tuberculosis (TB of the central nervous system (CNS is a deadly disease characterized by extensive tissue destruction, driven by molecules such as Matrix Metalloproteinase-2 (MMP-2 which targets CNS-specific substrates. In a simplified cellular model of CNS TB, we demonstrated that conditioned medium from Mycobacterium tuberculosis-infected primary human monocytes (CoMTb, but not direct infection, unexpectedly down-regulates constitutive microglial MMP-2 gene expression and secretion by 72.8% at 24 hours, sustained up to 96 hours (P M.tb-infected monocyte-dependent networks paradoxically involves the pro-inflammatory mediators TNF-α, p38 MAP kinase and NFκB in addition to a novel caspase 8-dependent pathway.

  9. Atuoradiographic detection of multiple sclerosis plaques with an ω3 (peripheral type benzodiazepine) binding site radiogland

    International Nuclear Information System (INIS)

    HAUW, J.J.; Sazdovitch, V.; Cornu, P.; Dubois, A.; Benavides, J.; Mac Kenzie, E.; Scatton, B.

    1989-01-01

    In Multiple Sclerosis (MS), the presence of monocyte-macrophages and microglial cells in active plaques is a constant feature. They are numerous at the border of active lesions where they constiture, with other cell types such as lymphocytes and oligodendrocytes the so-called flial wall. Monocyte-macrophages and microglial cells are thought to be directly involved in the process of demyelination. Some macrophages laden with meylin degradation products are also seen in the center of the plaqie, often located in the perivascular cuffs. In addition, astrocytic gliosis occurs in the center of the plaques. As all these cell types are richly endowed with ω3 sites, the feasibility of using ω3 site autoradiagraphy to detect the demyelination plaques in the brain of post-mortem cases of Multiple Sclerosis has been investigated. (Author). 8 refs

  10. Kinetic analysis of thymocyte attachment to thymus stromal cells in culture by using phase-contrast and scanning electron microscopy

    International Nuclear Information System (INIS)

    LaRochelle, G.G.; Jones, K.H.

    1989-01-01

    Direct cellular contact between thymocytes and thymus stromal cells within the thymus appears to contribute to the maturation of thymocytes. Thymocyte-stromal cell complexes, formed in vivo, have been isolated by others and postulated to play a role in T-cell differentiation. These previous studies have been hampered, however, by a time-consuming isolation procedure from which only small numbers of these complexes are recovered. We have examined a model to study thymocyte-stromal cell complexes in vitro in which thymocytes are added to primary cultures of thymus stromal cells. In the present study, we found that thymocytes were histotypically selective in their attachment to thymus stromal cells. We also investigated the kinetics of thymocyte attachment to these thymus stromal cells. Cultures were examined at selected time intervals from 5 min through 3 days of incubation. Thymocyte attachment to stromal cells was a biphasic interaction, with maximum surface attachment at 15 min of cocultivation, followed by migration of thymocytes into the cultures. Morphological studies were confirmed by using 3 H-leucine-labeled thymocytes and liquid scintigraphy. With increased time in culture, thymocytes became amoeboid and migrated between the layers of stromal cells where thymocyte mitotic figures were seen at 4 and 8 hr. In some cases it appeared that stromal cells, which often grew two to three cell layers deep, played an active role in enclosing thymocytes within the cultures. Large numbers of viable thymocytes were observed in the cultures at 24 hr. The number of thymocytes then decreased progressively on days 2 and 3, when relatively few were found within the layers of the culture

  11. Minocycline Transiently Reduces Microglia/Macrophage Activation but Exacerbates Cognitive Deficits Following Repetitive Traumatic Brain Injury in the Neonatal Rat

    Science.gov (United States)

    Hanlon, Lauren A.; Huh, Jimmy W.

    2016-01-01

    Elevated microglial/macrophage-associated biomarkers in the cerebrospinal fluid of infant victims of abusive head trauma (AHT) suggest that these cells play a role in the pathophysiology of the injury. In a model of AHT in 11-day-old rats, 3 impacts (24 hours apart) resulted in spatial learning and memory deficits and increased brain microglial/macrophage reactivity, traumatic axonal injury, neuronal degeneration, and cortical and white-matter atrophy. The antibiotic minocycline has been effective in decreasing injury-induced microglial/macrophage activation while simultaneously attenuating cellular and functional deficits in models of neonatal hypoxic ischemia, but the potential for this compound to rescue deficits after impact-based trauma to the immature brain remains unexplored. Acute minocycline administration in this model of AHT decreased microglial/macrophage reactivity in the corpus callosum of brain-injured animals at 3 days postinjury, but this effect was lost by 7 days postinjury. Additionally, minocycline treatment had no effect on traumatic axonal injury, neurodegeneration, tissue atrophy, or spatial learning deficits. Interestingly, minocycline-treated animals demonstrated exacerbated injury-induced spatial memory deficits. These results contrast with previous findings in other models of brain injury and suggest that minocycline is ineffective in reducing microglial/macrophage activation and ameliorating injury-induced deficits following repetitive neonatal traumatic brain injury. PMID:26825312

  12. Effect of GSM-1800 and U.M.T.S. exposures on micro-glial activation and heat shock proteins induction in brain: a study on young adult and elderly rats

    Energy Technology Data Exchange (ETDEWEB)

    Laclau, M; Billaudel, B; Taxil, M; Haro, E; Ruffie, G; Sanchez, S; Poulletier De Gannes, F; Lagroye, I; Veyret, B [PIOM/Bioelecromagnetics Lab., ENSCPB/EPHE, 33 - Pessac (France)

    2006-07-01

    Contradictory results have emerged from recent studies describing low -level radiofrequency radiation (R.F.R.) as a hazardous factor for the central nervous system while others described such type of exposure as totally safe. In the brain, heat shock proteins (H.s.p.) are often induced under harmful conditions such as ischemia, traumatic injury, epilepsy, hyperthermia, drug administration, and neuro-degenerative diseases. Under those conditions, activation of the micro-glial cell population is often observed. In this work we studied the effect of two types of mobile phone signals, GSM-1800 and U.M.T.S. on the expression of two major H.s.p., induced in the brain under harmful conditions, H.s.p. 70 and H.s.p. 25. We also studied micro-glial activation in young adult (8 weeks) and elderly (17 months) Wistar rats. Height animals by group were exposed. Exposures were performed using a brain-averaged S.A.R. of 2 W/kg following two types of protocols: an acute exposure, with exposure lasting only two hours, and a sub chronic exposure in which the animals were exposed for two hours per day, five days per week, during four weeks. In all cases, rats were progressively habituated to the exposure setup (rockets) over two weeks to avoid stress and a sham group was exposed for each condition. Positive controls were performed by induction of a status epilepticus using a subcutaneous injection kainic acid (10 mg/kg). At the end of exposure, rats were anesthetized with isofluran and perfused from the heart with P.B.S. then paraformaldehyde prior to removing of the brain. Sections (10 m m thick) were prepared on slides for immunohistochemistry. Brain samples were coded and the analysis was performed in a blind manner. The sections were immuno-histo-chemically stained with antibodies raised in rabbits against H.s.p.25 and against the inducible form of H.s.p.70. The whole glial cell population was detected by its common cell surface glyco conjugates, which bind the plant Griffonia

  13. Effect of GSM-1800 and U.M.T.S. exposures on micro-glial activation and heat shock proteins induction in brain: a study on young adult and elderly rats

    International Nuclear Information System (INIS)

    Laclau, M.; Billaudel, B.; Taxil, M.; Haro, E.; Ruffie, G.; Sanchez, S.; Poulletier De Gannes, F.; Lagroye, I.; Veyret, B.

    2006-01-01

    Contradictory results have emerged from recent studies describing low -level radiofrequency radiation (R.F.R.) as a hazardous factor for the central nervous system while others described such type of exposure as totally safe. In the brain, heat shock proteins (H.s.p.) are often induced under harmful conditions such as ischemia, traumatic injury, epilepsy, hyperthermia, drug administration, and neuro-degenerative diseases. Under those conditions, activation of the micro-glial cell population is often observed. In this work we studied the effect of two types of mobile phone signals, GSM-1800 and U.M.T.S. on the expression of two major H.s.p., induced in the brain under harmful conditions, H.s.p. 70 and H.s.p. 25. We also studied micro-glial activation in young adult (8 weeks) and elderly (17 months) Wistar rats. Height animals by group were exposed. Exposures were performed using a brain-averaged S.A.R. of 2 W/kg following two types of protocols: an acute exposure, with exposure lasting only two hours, and a sub chronic exposure in which the animals were exposed for two hours per day, five days per week, during four weeks. In all cases, rats were progressively habituated to the exposure setup (rockets) over two weeks to avoid stress and a sham group was exposed for each condition. Positive controls were performed by induction of a status epilepticus using a subcutaneous injection kainic acid (10 mg/kg). At the end of exposure, rats were anesthetized with isofluran and perfused from the heart with P.B.S. then paraformaldehyde prior to removing of the brain. Sections (10 m m thick) were prepared on slides for immunohistochemistry. Brain samples were coded and the analysis was performed in a blind manner. The sections were immuno-histo-chemically stained with antibodies raised in rabbits against H.s.p.25 and against the inducible form of H.s.p.70. The whole glial cell population was detected by its common cell surface glyco conjugates, which bind the plant Griffonia

  14. Tumour cells expressing single VEGF isoforms display distinct growth, survival and migration characteristics.

    Directory of Open Access Journals (Sweden)

    Chryso Kanthou

    Full Text Available Vascular endothelial growth factor-A (VEGF is produced by most cancer cells as multiple isoforms, which display distinct biological activities. VEGF plays an undisputed role in tumour growth, vascularisation and metastasis; nevertheless the functions of individual isoforms in these processes remain poorly understood. We investigated the effects of three main murine isoforms (VEGF188, 164 and 120 on tumour cell behaviour, using a panel of fibrosarcoma cells we developed that express them individually under endogenous promoter control. Fibrosarcomas expressing only VEGF188 (fs188 or wild type controls (fswt were typically mesenchymal, formed ruffles and displayed strong matrix-binding activity. VEGF164- and VEGF120-producing cells (fs164 and fs120 respectively were less typically mesenchymal, lacked ruffles but formed abundant cell-cell contacts. On 3D collagen, fs188 cells remained mesenchymal while fs164 and fs120 cells adopted rounded/amoeboid and a mix of rounded and elongated morphologies respectively. Consistent with their mesenchymal characteristics, fs188 cells migrated significantly faster than fs164 or fs120 cells on 2D surfaces while contractility inhibitors accelerated fs164 and fs120 cell migration. VEGF164/VEGF120 expression correlated with faster proliferation rates and lower levels of spontaneous apoptosis than VEGF188 expression. Nevertheless, VEGF188 was associated with constitutively active/phosphorylated AKT, ERK1/2 and Stat3 proteins. Differences in proliferation rates and apoptosis could be explained by defective signalling downstream of pAKT to FOXO and GSK3 in fs188 and fswt cells, which also correlated with p27/p21 cyclin-dependent kinase inhibitor over-expression. All cells expressed tyrosine kinase VEGF receptors, but these were not active/activatable suggesting that inherent differences between the cell lines are governed by endogenous VEGF isoform expression through complex interactions that are independent of tyrosine

  15. Evaluation of Antioxidant and Anti-neuroinflammatory Activities of ...

    African Journals Online (AJOL)

    in activated microglial cells has not been studied. Microglia are ... modulation frequency, 100 kHz; modulation amplitude, 2 G ... with 5 % non‐fat milk, the membranes were ..... reactive nitrogen oxides mediate neuronal cell death. Brain Res ...

  16. An Efficient Platform for Astrocyte Differentiation from Human Induced Pluripotent Stem Cells

    Directory of Open Access Journals (Sweden)

    Julia TCW

    2017-08-01

    Full Text Available Growing evidence implicates the importance of glia, particularly astrocytes, in neurological and psychiatric diseases. Here, we describe a rapid and robust method for the differentiation of highly pure populations of replicative astrocytes from human induced pluripotent stem cells (hiPSCs, via a neural progenitor cell (NPC intermediate. We evaluated this protocol across 42 NPC lines (derived from 30 individuals. Transcriptomic analysis demonstrated that hiPSC-astrocytes from four individuals are highly similar to primary human fetal astrocytes and characteristic of a non-reactive state. hiPSC-astrocytes respond to inflammatory stimulants, display phagocytic capacity, and enhance microglial phagocytosis. hiPSC-astrocytes also possess spontaneous calcium transient activity. Our protocol is a reproducible, straightforward (single medium, and rapid (<30 days method to generate populations of hiPSC-astrocytes that can be used for neuron-astrocyte and microglia-astrocyte co-cultures for the study of neuropsychiatric disorders.

  17. Seizure progression and inflammatory mediators promote pericytosis and pericyte-microglia clustering at the cerebrovasculature.

    Science.gov (United States)

    Klement, Wendy; Garbelli, Rita; Zub, Emma; Rossini, Laura; Tassi, Laura; Girard, Benoit; Blaquiere, Marine; Bertaso, Federica; Perroy, Julie; de Bock, Frederic; Marchi, Nicola

    2018-05-01

    Cerebrovascular dysfunction and inflammation occur in epilepsy. Here we asked whether pericytes, a pivotal cellular component of brain capillaries, undergo pathological modifications during experimental epileptogenesis and in human epilepsy. We evaluated whether pro-inflammatory cytokines, present in the brain during seizures, contribute to pericyte morphological modifications. In vivo, unilateral intra-hippocampal kainic acid (KA) injections were performed in NG2DsRed/C57BL6 mice to induce status epilepticus (SE), epileptogenesis, and spontaneous recurrent seizures (SRS). NG2DsRed mice were used to visualize pericytes during seizure progression. The effect triggered by recombinant IL-1β, TNFα, or IL-6 on pericytes was evaluated in NG2DsRed hippocampal slices and in human-derived cell culture. Human brain specimens obtained from temporal lobe epilepsy (TLE) with or without sclerosis (HS) and focal cortical dysplasia (FCD-IIb) were evaluated for pericyte-microglial cerebrovascular assembly. A disarray of NG2DsRed + pericyte soma and ramifications was found 72 h post-SE and 1 week post-SE (epileptogenesis) in the hippocampus. Pericyte modifications topographically overlapped with IBA1 + microglia clustering around the capillaries with cases of pericytes lodged within the microglial cells. Microglial clustering around the NG2DsRed pericytes lingered at SRS. Pericyte proliferation (Ki67 + ) occurred 72 h post-SE and during epileptogenesis and returned towards control levels at SRS. Human epileptic brain tissues showed pericyte-microglia assemblies with IBA1/HLA microglial cells outlining the capillary wall in TLE-HS and FCD-IIb specimens. Inflammatory mediators contributed to pericyte modifications, in particular IL-1β elicited pericyte morphological changes and pericyte-microglia clustering in NG2DsRed hippocampal slices. Modifications also occurred when pro-inflammatory cytokines were added to an in vitro culture of pericytes. These results indicate the

  18. Gc-protein-derived macrophage activating factor counteracts the neuronal damage induced by oxaliplatin.

    Science.gov (United States)

    Morucci, Gabriele; Branca, Jacopo J V; Gulisano, Massimo; Ruggiero, Marco; Paternostro, Ferdinando; Pacini, Alessandra; Di Cesare Mannelli, Lorenzo; Pacini, Stefania

    2015-02-01

    Oxaliplatin-based regimens are effective in metastasized advanced cancers. However, a major limitation to their widespread use is represented by neurotoxicity that leads to peripheral neuropathy. In this study we evaluated the roles of a proven immunotherapeutic agent [Gc-protein-derived macrophage activating factor (GcMAF)] in preventing or decreasing oxaliplatin-induced neuronal damage and in modulating microglia activation following oxaliplatin-induced damage. The effects of oxaliplatin and of a commercially available formula of GcMAF [oleic acid-GcMAF (OA-GcMAF)] were studied in human neurons (SH-SY5Y cells) and in human microglial cells (C13NJ). Cell density, morphology and viability, as well as production of cAMP and expression of vascular endothelial growth factor (VEGF), markers of neuron regeneration [neuromodulin or growth associated protein-43 (Gap-43)] and markers of microglia activation [ionized calcium binding adaptor molecule 1 (Iba1) and B7-2], were determined. OA-GcMAF reverted the damage inflicted by oxaliplatin on human neurons and preserved their viability. The neuroprotective effect was accompanied by increased intracellular cAMP production, as well as by increased expression of VEGF and neuromodulin. OA-GcMAF did not revert the effects of oxaliplatin on microglial cell viability. However, it increased microglial activation following oxaliplatin-induced damage, resulting in an increased expression of the markers Iba1 and B7-2 without any concomitant increase in cell number. When neurons and microglial cells were co-cultured, the presence of OA-GcMAF significantly counteracted the toxic effects of oxaliplatin. Our results demonstrate that OA-GcMAF, already used in the immunotherapy of advanced cancers, may significantly contribute to neutralizing the neurotoxicity induced by oxaliplatin, at the same time possibly concurring to an integrated anticancer effect. The association between these two powerful anticancer molecules would probably produce

  19. Different distribution patterns of lymphocytes and microglia in the hippocampus of patients with residual versus paranoid schizophrenia: further evidence for disease course-related immune alterations?

    Science.gov (United States)

    Busse, Stefan; Busse, Mandy; Schiltz, Kolja; Bielau, Hendrik; Gos, Tomasz; Brisch, Ralf; Mawrin, Christian; Schmitt, Andrea; Jordan, Wolfgang; Müller, Ulf J; Bernstein, Hans-Gert; Bogerts, Bernhard; Steiner, Johann

    2012-11-01

    Certain cytokines have been identified in the peripheral blood as trait markers of schizophrenia, while others are considered relapse-related state markers. Furthermore, data from peripheral blood, cerebrospinal fluid (CSF) and nuclear imaging studies suggest that (1) blood-brain barrier (BBB) dysfunction (e.g., immigration of lymphocytes into brain tissue and intrathecal antibody production) correlates with the development of negative symptoms, while (2) the brain's mononuclear phagocyte system (microglial cells) is activated during acute psychosis. Based on these neuroinflammatory hypotheses, we have quantified the numerical density of immunostained CD3+ T-lymphocytes, CD20+ B-lymphocytes, and HLA-DR+ microglial cells in the posterior hippocampus of 17 schizophrenia patients and 11 matched controls. Disease course-related immune alterations were considered by a separate analysis of residual (prevailing negative symptoms, n=7) and paranoid (prominent positive symptoms, n=10) schizophrenia cases. Higher densities of CD3+ and CD20+ lymphocytes were observed in residual versus paranoid schizophrenia (CD 3: left: P=0.047, right: P=0.038; CD20: left: P=0.020, right: P=0.010) and controls (CD3: left: P=0.057, right: P=0.069; CD20: left: P=0.008, right: P=0.006). In contrast, HLA-DR+ microglia were increased in paranoid schizophrenia versus residual schizophrenia (left: P=0.030, right: P=0.012). A similar trend emerged when this group was compared to controls (left: P=0.090, right: P=0.090). BBB impairment and infiltration of T cells and B cells may contribute to the pathophysiology of residual schizophrenia, while microglial activation seems to play a role in paranoid schizophrenia. The identification of diverse immune endophenotypes may facilitate the development of distinct anti-inflammatory schizophrenia therapies to normalize BBB function, (auto)antibody production or microglial activity. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. Anti-neuroinflammatory effect of 6,8,1'-tri-O-methylaverantin, a metabolite from a marine-derived fungal strain Aspergillus sp., via upregulation of heme oxygenase-1 in lipopolysaccharide-activated microglia.

    Science.gov (United States)

    Kim, Kwan-Woo; Kim, Hye Jin; Sohn, Jae Hak; Yim, Joung Han; Kim, Youn-Chul; Oh, Hyuncheol

    2018-02-01

    In the course of searching for anti-neuroinflammatory metabolites from marine-derived fungi, three fungal metabolites, 6,8,1'-tri-O-methylaverantin, 6,8-di-O-methylaverufin, and 5-methoxysterigmatocystin were isolated from a marine-derived fungal strain Aspergillus sp. SF-6796. Among these, 6,8,1'-tri-O-methylaverantin induced the expression of heme oxygenase (HO)-1 protein in BV2 microglial cells. The induction of HO-1 protein was mediated by the activation of nuclear transcription factor erythroid-2 related factor 2 (Nrf2), and was regulated by the p38 mitogen-activated protein kinase and phosphatidylinositol 3-kinase/protein kinase B signaling pathways. Furthermore, 6,8,1'-tri-O-methylaverantin suppressed the overproduction of pro-inflammatory mediators, such as nitric oxide, prostaglandin E 2 , inducible nitric oxide synthase, and cyclooxygenase-2 in lipopolysaccharide (LPS)-stimulated BV2 microglial cells. These anti-neuroinflammatory effects were mediated through the negative regulation of the nuclear factor kappa B pathway, repressing the phosphorylation and degradation of inhibitor kappa B-α, translocation into the nucleus of p65/p50 heterodimer, and DNA-binding activity of p65 subunit. The anti-neuroinflammatory effect of 6,8,1'-tri-O-methylaverantin was partially blocked by a selective HO-1 inhibitor, suggesting that its anti-neuroinflammatory effect is at least partly mediated by HO-1 induction. In this study, 6,8,1'-tri-O-methylaverantin also induced HO-1 protein expression in primary microglial cells, and this correlated with anti-neuroinflammatory effects observed in LPS-stimulated primary microglial cells. In conclusion, 6,8,1'-tri-O-methylaverantin represents a potential candidate for use in the development of therapeutic agents for the regulation of neuroinflammation in neurodegenerative diseases. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Methamphetamine abuse affects gene expression in brain-derived microglia of SIV-infected macaques to enhance inflammation and promote virus targets

    KAUST Repository

    Najera, Julia A.; Bustamante, Eduardo A.; Bortell, Nikki; Morsey, Brenda; Fox, Howard S.; Ravasi, Timothy; Marcondes, Maria Cecilia Garibaldi

    2016-01-01

    /function of innate immune cells and increase brain viral loads. Here, we examined changes in the gene expression profile of neuron-free microglial cell preparations isolated from the brain of macaques infected with the Simian Immunodeficiency Virus (SIV), a model

  2. Supplementary Material for: Methamphetamine abuse affects gene expression in brain-derived microglia of SIV-infected macaques to enhance inflammation and promote virus targets

    KAUST Repository

    Najera, Julia; Bustamante, Eduardo; Bortell, Nikki; Morsey, Brenda; Fox, Howard; Ravasi, Timothy; Marcondes, Maria

    2016-01-01

    /function of innate immune cells and increase brain viral loads. Here, we examined changes in the gene expression profile of neuron-free microglial cell preparations isolated from the brain of macaques infected with the Simian Immunodeficiency Virus (SIV), a model

  3. Enhanced biocompatibility of neural probes by integrating microstructures and delivering anti-inflammatory agents via microfluidic channels

    Science.gov (United States)

    Liu, Bin; Kim, Eric; Meggo, Anika; Gandhi, Sachin; Luo, Hao; Kallakuri, Srinivas; Xu, Yong; Zhang, Jinsheng

    2017-04-01

    Objective. Biocompatibility is a major issue for chronic neural implants, involving inflammatory and wound healing responses of neurons and glial cells. To enhance biocompatibility, we developed silicon-parylene hybrid neural probes with open architecture electrodes, microfluidic channels and a reservoir for drug delivery to suppress tissue responses. Approach. We chronically implanted our neural probes in the rat auditory cortex and investigated (1) whether open architecture electrode reduces inflammatory reaction by measuring glial responses; and (2) whether delivery of antibiotic minocycline reduces inflammatory and tissue reaction. Four weeks after implantation, immunostaining for glial fibrillary acid protein (astrocyte marker) and ionizing calcium-binding adaptor molecule 1 (macrophages/microglia cell marker) were conducted to identify immunoreactive astrocyte and microglial cells, and to determine the extent of astrocytes and microglial cell reaction/activation. A comparison was made between using traditional solid-surface electrodes and newly-designed electrodes with open architecture, as well as between deliveries of minocycline and artificial cerebral-spinal fluid diffused through microfluidic channels. Main results. The new probes with integrated micro-structures induced minimal tissue reaction compared to traditional electrodes at 4 weeks after implantation. Microcycline delivered through integrated microfluidic channels reduced tissue response as indicated by decreased microglial reaction around the neural probes implanted. Significance. The new design will help enhance the long-term stability of the implantable devices.

  4. Methanol Extract of Myelophycus caespitosus Inhibits the ...

    African Journals Online (AJOL)

    Methanol Extract of Myelophycus caespitosus Inhibits the Inflammatory Response in Lipopolysaccharidestimulated BV2 Microglial Cells by Downregulating NF-kB via Inhibition of the Akt Signaling Pathway.

  5. Microglia: An Interface between the Loss of Neuroplasticity and Depression

    Directory of Open Access Journals (Sweden)

    Gaurav Singhal

    2017-09-01

    Full Text Available Depression has been widely accepted as a major psychiatric disease affecting nearly 350 million people worldwide. Research focus is now shifting from studying the extrinsic and social factors of depression to the underlying molecular causes. Microglial activity is shown to be associated with pathological conditions, such as psychological stress, pathological aging, and chronic infections. These are primary immune effector cells in the CNS and regulate the extensive dialogue between the nervous and the immune systems in response to different immunological, physiological, and psychological stressors. Studies have suggested that during stress and pathologies, microglia play a significant role in the disruption of neuroplasticity and have detrimental effects on neuroprotection causing neuroinflammation and exacerbation of depression. After a systematic search of literature databases, relevant articles on the microglial regulation of bidirectional neuroimmune pathways affecting neuroplasticity and leading to depression were reviewed. Although, several hypotheses have been proposed for the microglial role in the onset of depression, it is clear that all molecular pathways to depression are linked through microglia-associated neuroinflammation and hippocampal degeneration. Molecular factors such as an excess of glucocorticoids and changes in gene expression of neurotrophic factors, as well as neuro active substances secreted by gut microbiota have also been shown to affect microglial morphology and phenotype resulting in depression. This review aims to critically analyze the various molecular pathways associated with the microglial role in depression.

  6. Silver nanoparticles reduce brain inflammation and related neurotoxicity through induction of H2S-synthesizing enzymes

    Science.gov (United States)

    Gonzalez-Carter, Daniel A.; Leo, Bey Fen; Ruenraroengsak, Pakatip; Chen, Shu; Goode, Angela E.; Theodorou, Ioannis G.; Chung, Kian Fan; Carzaniga, Raffaella; Shaffer, Milo S. P.; Dexter, David T.; Ryan, Mary P.; Porter, Alexandra E.

    2017-03-01

    Silver nanoparticles (AgNP) are known to penetrate into the brain and cause neuronal death. However, there is a paucity in studies examining the effect of AgNP on the resident immune cells of the brain, microglia. Given microglia are implicated in neurodegenerative disorders such as Parkinson’s disease (PD), it is important to examine how AgNPs affect microglial inflammation to fully assess AgNP neurotoxicity. In addition, understanding AgNP processing by microglia will allow better prediction of their long term bioreactivity. In the present study, the in vitro uptake and intracellular transformation of citrate-capped AgNPs by microglia, as well as their effects on microglial inflammation and related neurotoxicity were examined. Analytical microscopy demonstrated internalization and dissolution of AgNPs within microglia and formation of non-reactive silver sulphide (Ag2S) on the surface of AgNPs. Furthermore, AgNP-treatment up-regulated microglial expression of the hydrogen sulphide (H2S)-synthesizing enzyme cystathionine-γ-lyase (CSE). In addition, AgNPs showed significant anti-inflammatory effects, reducing lipopolysaccharide (LPS)-stimulated ROS, nitric oxide and TNFα production, which translated into reduced microglial toxicity towards dopaminergic neurons. Hence, the present results indicate that intracellular Ag2S formation, resulting from CSE-mediated H2S production in microglia, sequesters Ag+ ions released from AgNPs, significantly limiting their toxicity, concomitantly reducing microglial inflammation and related neurotoxicity.

  7. Involvement of Phosphatidylinositol 3-Kinase-Mediated Up-Regulation of IκBα in Anti-Inflammatory Effect of Gemfibrozil in Microglia1

    Science.gov (United States)

    Jana, Malabendu; Jana, Arundhati; Liu, Xiaojuan; Ghosh, Sankar; Pahan, Kalipada

    2008-01-01

    The present study underlines the importance of PI3K in mediating the anti-inflammatory effect of gemfibrozil, a prescribed lipid-lowering drug for humans, in mouse microglia. Gemfibrozil inhibited LPS-induced expression of inducible NO synthase (iNOS) and proinflammatory cytokines in mouse BV-2 microglial cells and primary microglia. By overexpressing wild-type and dominant-negative constructs of peroxisome proliferator-activated receptor-α (PPAR-α) in microglial cells and isolating primary microglia from PPAR-α−/− mice, we have demonstrated that gemfibrozil inhibits the activation of microglia independent of PPAR-α. Interestingly, gemfibrozil induced the activation of p85α-associated PI3K (p110β but not p110α) and inhibition of that PI3K by either chemical inhibitors or dominant-negative mutants abrogated the inhibitory effect of gemfibrozil. Conversely, overexpression of the constitutively active mutant of p110 enhanced the inhibitory effect of gemfibrozil on LPS-induced expression of proinflammatory molecules. Similarly, gemfibrozil also inhibited fibrillar amyloid β (Aβ)-, prion peptide (PrP)-, dsRNA (poly IC)-, HIV-1 Tat-, and 1-methyl-4-phenylpyridinium (MPP+)-, but not IFN-γ-, induced microglial expression of iNOS. Inhibition of PI3K also abolished the inhibitory effect of gemfibrozil on Aβ-, PrP-, poly IC-, Tat-, and MPP+-induced microglial expression of iNOS. Involvement of NF-κB activation in LPS-, Aβ-, PrP-, poly IC-, Tat-, and MPP+-, but not IFN-γ-, induced microglial expression of iNOS and stimulation of IκBα expression and inhibition of NF-κB activation by gemfibrozil via the PI3K pathway suggests that gemfibrozil inhibits the activation of NF-κB and the expression of proinflammatory molecules in microglia via PI3K-mediated up-regulation of IκBα. PMID:17785853

  8. Diagnosis of Oral Lesions associated with HIV/AIDS | Hamza ...

    African Journals Online (AJOL)

    HIV has a lipid envelope that has specific glycoproteins that attach to CD4 protein on cell surface. Cells which express CD4 protein are at risk of infection with HIV including CD4 lymphocytes, monocytes, macrophages, microglial cells, and langerhan's cells in skin. Disturbances in number and function of CD4 cells lead to ...

  9. Anti-inflammatory effects of glaucocalyxin B in microglia cells

    Directory of Open Access Journals (Sweden)

    Ping Gan

    2015-05-01

    Full Text Available Over-activated microglia is involved in various kinds of neurodegenerative process including Parkinson, Alzheimer and HIV dementia. Suppression of microglial over activation has emerged as a novel strategy for treatment of neuroinflammation-based neurodegeneration. In the current study, anti-inflammatory and neuroprotective effects of the ent-kauranoid diterpenoids, which were isolated from the aerial parts of Rabdosia japonica (Burm. f. var. glaucocalyx (Maxim. Hara, were investigated in cultured microglia cells. Glaucocalyxin B (GLB, one of five ent-kauranoid diterpenoids, significantly decreased the generation of nitric oxide (NO, tumor necrosis factor (TNF-α, interleukin (IL-1β, cyclooxygenase (COX-2 and inducible nitric oxide synthase (iNOS in the lipopolysaccharide (LPS-activated microglia cells. In addition, GLB inhibited activation of nuclear factor-κB (NF-κB, p38 mitogen-activated protein kinase (MAPK and generation of reactive oxygen species (ROS in LPS-activated microglia cells. Furthermore, GLB strongly induced the expression of heme oxygenase (HO-1 in BV-2 microglia cells. Finally, GLB exhibited neuroprotective effect by preventing over-activated microglia induced neurotoxicity in a microglia/neuron co-culture model. Taken together, the present study demonstrated that the GLB possesses anti-nueroinflammatory activity, and might serve as a potential therapeutic agent for treating neuroinflammatory diseases.

  10. Biomarkers of delirium as a clue to diagnosis and pathogenesis of Wernicke-Korsakoff syndrome.

    Science.gov (United States)

    Wijnia, J W; Oudman, E

    2013-12-01

    Wernicke's encephalopathy (WE) and Korsakoff's syndrome are considered to be different stages of the same disorder due to thiamine deficiency, which is called Wernicke-Korsakoff syndrome (WKS). The earliest biochemical change is the decrease of α-ketoglutarate-dehydrogenase activity in astrocytes. According to autopsy-based series, mental status changes are present in 82% of WE cases. The objective of the present review is to identify possible underlying mechanisms relating the occurrence of delirium to WKS. Studies involving delirium in WKS, however, are rare. Therefore, first, a search was done for candidate biomarkers of delirium irrespective of the clinical setting. Secondly, the results were focused on identification of these biomarkers in reports on WKS. In various settings, 10 biochemical and/or genetic biomarkers showed strong associations with the occurrence of delirium. For WKS three of these candidate biomarkers were identified, namely brain tissue cell counts of CD68 positive cells as a marker of microglial activation, high cerebrospinal fluid lactate levels, and MHPG, a metabolite of norepinephrine. Based on current literature, markers of microglial activation may present an interesting patho-etiological relationship between thiamine deficiency and delirium in WKS. In WKS cases, changes in astroglia and microglial proliferation were reported. The possible loss-of-function mechanisms following thiamine deficiency in WKS are proposed to come from microglial activation, resulting in a delirium in the initial phase of WKS. © 2013 The Author(s) European Journal of Neurology © 2013 EFNS.

  11. Altered Loyalties of Neuronal Markers in Cultured Slices of Resected Human Brain Tissue

    NARCIS (Netherlands)

    Verwer, Ronald W. H.; Sluiter, Arja A.; Balesar, Rawien A.; Baayen, Johannes C.; Speijer, Dave; Idema, Sander; Swaab, Dick F.

    2016-01-01

    Organotypic cultures from normal neocortical tissue obtained at epilepsy surgery show a severe injury response. This response involves both neuronal degeneration and the proliferation of reactive cells. A salient feature of the reactive cells is the co-expression of microglial and astrocytic

  12. Regulation of ICAM-1 in Cells of the Monocyte/Macrophage System in Microgravity

    Directory of Open Access Journals (Sweden)

    Katrin Paulsen

    2015-01-01

    Full Text Available Cells of the immune system are highly sensitive to altered gravity, and the monocyte as well as the macrophage function is proven to be impaired under microgravity conditions. In our study, we investigated the surface expression of ICAM-1 protein and expression of ICAM-1 mRNA in cells of the monocyte/macrophage system in microgravity during clinostat, parabolic flight, sounding rocket, and orbital experiments. In murine BV-2 microglial cells, we detected a downregulation of ICAM-1 expression in clinorotation experiments and a rapid and reversible downregulation in the microgravity phase of parabolic flight experiments. In contrast, ICAM-1 expression increased in macrophage-like differentiated human U937 cells during the microgravity phase of parabolic flights and in long-term microgravity provided by a 2D clinostat or during the orbital SIMBOX/Shenzhou-8 mission. In nondifferentiated U937 cells, no effect of microgravity on ICAM-1 expression could be observed during parabolic flight experiments. We conclude that disturbed immune function in microgravity could be a consequence of ICAM-1 modulation in the monocyte/macrophage system, which in turn could have a strong impact on the interaction with T lymphocytes and cell migration. Thus, ICAM-1 can be considered as a rapid-reacting and sustained gravity-regulated molecule in mammalian cells.

  13. Effects of oxaliplatin and oleic acid Gc-protein-derived macrophage-activating factor on murine and human microglia.

    Science.gov (United States)

    Branca, Jacopo J V; Morucci, Gabriele; Malentacchi, Francesca; Gelmini, Stefania; Ruggiero, Marco; Pacini, Stefania

    2015-09-01

    The biological properties and characteristics of microglia in rodents have been widely described, but little is known about these features in human microglia. Several murine microglial cell lines are used to investigate neurodegenerative and neuroinflammatory conditions; however, the extrapolation of the results to human conditions is frequently met with criticism because of the possibility of species-specific differences. This study compares the effects of oxaliplatin and of oleic acid Gc-protein-derived macrophage-activating factor (OA-GcMAF) on two microglial cell lines, murine BV-2 cells and human C13NJ cells. Cell viability, cAMP levels, microglial activation, and vascular endothelial growth factor (VEGF) expression were evaluated. Our data demonstrate that oxaliplatin induced a significant decrease in cell viability in BV-2 and in C13NJ cells and that this effect was not reversed with OA-GcMAF treatment. The signal transduction pathway involving cAMP/VEGF was activated after treatment with oxaliplatin and/or OA-GcMAF in both cell lines. OA-GcMAF induced a significant increase in microglia activation, as evidenced by the expression of the B7-2 protein, in BV-2 as well as in C13NJ cells that was not associated with a concomitant increase in cell number. Furthermore, the effects of oxaliplatin and OA-GcMAF on coculture morphology and apoptosis were evaluated. Oxaliplatin-induced cell damage and apoptosis were nearly completely reversed by OA-GcMAF treatment in both BV-2/SH-SY5Y and C13NJ/SH-SY5Y cocultures. Our data show that murine and human microglia share common signal transduction pathways and activation mechanisms, suggesting that the murine BV-2 cell line may represent an excellent model for studying human microglia. © 2015 Wiley Periodicals, Inc.

  14. Persistent Increase in Microglial RAGE Contributes to Chronic Stress-Induced Priming of Depressive-like Behavior.

    Science.gov (United States)

    Franklin, Tina C; Wohleb, Eric S; Zhang, Yi; Fogaça, Manoela; Hare, Brendan; Duman, Ronald S

    2018-01-01

    Chronic stress-induced inflammatory responses occur in part via danger-associated molecular pattern (DAMP) molecules, such as high mobility group box 1 protein (HMGB1), but the receptor(s) underlying DAMP signaling have not been identified. Microglia morphology and DAMP signaling in enriched rat hippocampal microglia were examined during the development and expression of chronic unpredictable stress (CUS)-induced behavioral deficits, including long-term, persistent changes after CUS. The results show that CUS promotes significant morphological changes and causes robust upregulation of HMGB1 messenger RNA in enriched hippocampal microglia, an effect that persists for up to 6 weeks after CUS exposure. This coincides with robust and persistent upregulation of receptor for advanced glycation end products (RAGE) messenger RNA, but not toll-like receptor 4 in hippocampal microglia. CUS also increased surface expression of RAGE protein on hippocampal microglia as determined by flow cytometry and returned to basal levels 5 weeks after CUS. Importantly, exposure to short-term stress was sufficient to increase RAGE surface expression as well as anhedonic behavior, reflecting a primed state that results from a persistent increase in RAGE messenger RNA expression. Further evidence for DAMP signaling in behavioral responses is provided by evidence that HMGB1 infusion into the hippocampus was sufficient to cause anhedonic behavior and by evidence that RAGE knockout mice were resilient to stress-induced anhedonia. Together, the results provide evidence of persistent microglial HMGB1-RAGE expression that increases vulnerability to depressive-like behaviors long after chronic stress exposure. Copyright © 2017 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  15. Microglia Responses in Acute and Chronic Neurological Diseases: What Microglia-Specific Transcriptomic Studies Taught (and did Not Teach Us

    Directory of Open Access Journals (Sweden)

    Hélène E. Hirbec

    2017-07-01

    Full Text Available Over the last decade, microglia have been acknowledged to be key players in central nervous system (CNS under both physiological and pathological conditions. They constantly survey the CNS environment and as immune cells, in pathological contexts, they provide the first host defense and orchestrate the immune response. It is well recognized that under pathological conditions microglia have both sequential and simultaneous, beneficial and detrimental effects. Cell-specific transcriptomics recently became popular in Neuroscience field allowing concurrent monitoring of the expression of numerous genes in a given cell population. Moreover, by comparing two or more conditions, these approaches permit to unbiasedly identify deregulated genes and pathways. A growing number of studies have thus investigated microglial transcriptome remodeling over the course of neuropathological conditions and highlighted the molecular diversity of microglial response to different diseases. In the present work, we restrict our review to microglia obtained directly from in vivo samples and not cell culture, and to studies using whole-genome strategies. We first critically review the different methods developed to decipher microglia transcriptome. In particular, we compare advantages and drawbacks of flow cytometry and laser microdissection to isolate pure microglia population as well as identification of deregulated microglial genes obtained via RNA sequencing (RNA-Seq vs. microarrays approaches. Second, we summarize insights obtained from microglia transcriptomes in traumatic brain and spinal cord injuries, pain and more chronic neurological conditions including Amyotrophic lateral sclerosis (ALS, Alzheimer disease (AD and Multiple sclerosis (MS. Transcriptomic responses of microglia in other non-neurodegenerative CNS disorders such as gliomas and sepsis are also addressed. Third, we present a comparison of the most activated pathways in each neuropathological condition

  16. An Efficient Platform for Astrocyte Differentiation from Human Induced Pluripotent Stem Cells.

    Science.gov (United States)

    Tcw, Julia; Wang, Minghui; Pimenova, Anna A; Bowles, Kathryn R; Hartley, Brigham J; Lacin, Emre; Machlovi, Saima I; Abdelaal, Rawan; Karch, Celeste M; Phatnani, Hemali; Slesinger, Paul A; Zhang, Bin; Goate, Alison M; Brennand, Kristen J

    2017-08-08

    Growing evidence implicates the importance of glia, particularly astrocytes, in neurological and psychiatric diseases. Here, we describe a rapid and robust method for the differentiation of highly pure populations of replicative astrocytes from human induced pluripotent stem cells (hiPSCs), via a neural progenitor cell (NPC) intermediate. We evaluated this protocol across 42 NPC lines (derived from 30 individuals). Transcriptomic analysis demonstrated that hiPSC-astrocytes from four individuals are highly similar to primary human fetal astrocytes and characteristic of a non-reactive state. hiPSC-astrocytes respond to inflammatory stimulants, display phagocytic capacity, and enhance microglial phagocytosis. hiPSC-astrocytes also possess spontaneous calcium transient activity. Our protocol is a reproducible, straightforward (single medium), and rapid (method to generate populations of hiPSC-astrocytes that can be used for neuron-astrocyte and microglia-astrocyte co-cultures for the study of neuropsychiatric disorders. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  17. Kynurenic Acid Prevents Cytoskeletal Disorganization Induced by Quinolinic Acid in Mixed Cultures of Rat Striatum.

    Science.gov (United States)

    Pierozan, Paula; Biasibetti-Brendler, Helena; Schmitz, Felipe; Ferreira, Fernanda; Pessoa-Pureur, Regina; Wyse, Angela T S

    2018-06-01

    Kynurenic acid (KYNA) is a neuroactive metabolite of tryptophan known to modulate a number of mechanisms involved in neural dysfunction. Although its activity in the brain has been widely studied, the effect of KYNA counteracting the actions of quinolinic acid (QUIN) remains unknown. The present study aims at describing the ability of 100 μM KYNA preventing cytoskeletal disruption provoked by QUIN in astrocyte/neuron/microglia mixed culture. KYNA totally preserved cytoskeletal organization, cell morphology, and redox imbalance in mixed cultures exposed to QUIN. However, KYNA partially prevented morphological alteration in isolated primary astrocytes and failed to protect the morphological alterations of neurons caused by QUIN exposure. Moreover, KYNA prevented QUIN-induced microglial activation and upregulation of ionized calcium-binding adapter molecule 1 (Iba-1) and partially preserved tumor necrosis factor-α (TNF-α) level in mixed cultures. TNF-α level was also partially preserved in astrocytes. In addition to the mechanisms dependent on redox imbalance and microglial activation, KYNA prevented downregulation of connexin-43 and the loss of functionality of gap junctions (GJs), preserving cell-cell contact, cytoskeletal organization, and cell morphology in QUIN-treated cells. Furthermore, the toxicity of QUIN targeting the cytoskeleton of mixed cultures was not prevented by the N-methyl-D-aspartate (NMDA) antagonist MK-801. We suggest that KYNA protects the integrity of the cytoskeleton of mixed cultures by complex mechanisms including modulating microglial activation preventing oxidative imbalance and misregulated GJs leading to disrupted cytoskeleton in QUIN-treated cells. This study contributed to elucidate the molecular basis of KYNA protection against QUIN toxicity.

  18. Coupled Proliferation and Apoptosis Maintain the Rapid Turnover of Microglia in the Adult Brain

    Directory of Open Access Journals (Sweden)

    Katharine Askew

    2017-01-01

    Full Text Available Summary: Microglia play key roles in brain development, homeostasis, and function, and it is widely assumed that the adult population is long lived and maintained by self-renewal. However, the precise temporal and spatial dynamics of the microglial population are unknown. We show in mice and humans that the turnover of microglia is remarkably fast, allowing the whole population to be renewed several times during a lifetime. The number of microglial cells remains steady from late postnatal stages until aging and is maintained by the spatial and temporal coupling of proliferation and apoptosis, as shown by pulse-chase studies, chronic in vivo imaging of microglia, and the use of mouse models of dysregulated apoptosis. Our results reveal that the microglial population is constantly and rapidly remodeled, expanding our understanding of its role in the maintenance of brain homeostasis. : The mechanism or mechanisms underlying microglial homeostasis are unknown. Askew et al. show that microglia self-renewal is maintained by coupled proliferation and apoptosis, resulting in a stable microglia number over a mouse or human lifetime. Keywords: self-renewal, BrdU, CSF1R, CX3CR1, Macgreen, Vav-Bcl2, RNA-seq

  19. CpG-ODNs induces up-regulated expression of chemokine CCL9 in mouse macrophages and microglia

    Digital Repository Service at National Institute of Oceanography (India)

    Ravindran, C.; Cheng, Y.-C.; Liang, S.-M.

    G-ODNs on macrophage/microglial cells are investigated. CpG-ODNs enhanced the expression of TLR9 mRNA of RAW264.7 macrophage and BV2 microglia cells time dependently. The expression of CCL9 of macrophages/microglia showed different responsiveness upon stimulation...

  20. The Ayurvedic plant Bacopa monnieri inhibits inflammatory pathways in the brain.

    Science.gov (United States)

    Nemetchek, Michelle D; Stierle, Andrea A; Stierle, Donald B; Lurie, Diana I

    2017-02-02

    Bacopa monnieri (L) Wettst (common name, bacopa) is a medicinal plant used in Ayurveda, the traditional system of medicine of India, as a nootropic. It is considered to be a "medhya rasayana", an herb that sharpens the mind and the intellect. Bacopa is an important ingredient in many Ayurvedic herbal formulations designed to treat conditions such as memory loss, anxiety, poor cognition and loss of concentration. It has also been used in Ayurveda to treat inflammatory conditions such as arthritis. In modern biomedical studies, bacopa has been shown in animal models to inhibit the release of the pro-inflammatory cytokines TNF-α and IL-6. However, less is known regarding the anti-inflammatory activity of Bacopa in the brain. The current study examines the ability of Bacopa to inhibit the release of pro-inflammatory cytokines from microglial cells, the immune cells of the brain that participate in inflammation in the CNS. The effect of Bacopa on signaling enzymes associated with CNS inflammatory pathways was also studied. Various extracts of Bacopa were prepared and examined in the N9 microglial cell line in order to determine if they inhibited the release of the proinflammatory cytokines TNF-α and IL-6. Extracts were also tested in cell free assays as inhibitors of caspase-1 and matrix metalloproteinase-3 (enzymes associated with inflammation) and caspase-3, which has been shown to cleave protein Tau, an early event in the development of Alzheimer's disease. The tea, infusion, and alkaloid extracts of bacopa, as well as Bacoside A significantly inhibited the release of TNF-α and IL-6 from activated N9 microglial cells in vitro. In addition, the tea, infusion, and alkaloid extracts of Bacopa effectively inhibited caspase 1 and 3, and matrix metalloproteinase-3 in the cell free assay. Bacopa inhibits the release of inflammatory cytokines from microglial cells and inhibits enzymes associated with inflammation in the brain. Thus, Bacopa can limit inflammation in the

  1. The Ayurvedic plant Bacopa Monnieri inhibits inflammatory pathways in the brain

    Science.gov (United States)

    Nemetchek, Michelle D.; Stierle, Andrea A.; Stierle, Donald B.; Lurie, Diana I.

    2016-01-01

    Ethnopharmacological Relevance Bacopa monnieri (L) Wettst (common name, bacopa) is a medicinal plant used in Ayurveda, the traditional system of medicine of India, as a nootropic. It is considered to be a “medhya rasayana”, an herb that sharpens the mind and the intellect. Bacopa is an important ingredient in many Ayurvedic herbal formulations designed to treat conditions such as memory loss, anxiety, poor cognition and loss of concentration. It has also been used in Ayurveda to treat inflammatory conditions such as arthritis. In modern biomedical studies, bacopa has been shown in animal models to inhibit the release of the pro-inflammatory cytokines TNF-α and IL-6. However, less is known regarding the anti-inflammatory activity of Bacopa in the brain. Aim Of The Study The current study examines the ability of Bacopa to inhibit the release of pro-inflammatory cytokines from microglial cells, the immune cells of the brain that participate in inflammation in the CNS. The effect of Bacopa on signaling enzymes associated with CNS inflammatory pathways was also studied. Materials And Methods Various extracts of Bacopa were prepared and examined in the N9 microglial cell line in order to determine if they inhibited the release of the proinflammatory cytokines TNF-α and IL-6. Extracts were also tested in cell free assays as inhibitors of caspase-1 and matrix metalloproteinase-3 (enzymes associated with inflammation) and caspase-3, which has been shown to cleave protein Tau, an early event in the development of Alzheimer's disease. Results The tea, infusion, and alkaloid extracts of bacopa, as well as Bacoside A significantly inhibited the release of TNF-α and IL-6 from activated N9 microglial cells in vitro. In addition, the tea, infusion, and alkaloid extracts of Bacopa effectively inhibited caspase 1 and 3, and matrix metalloproteinase-3 in the cell free assay. Conclusions Bacopa inhibits the release of inflammatory cytokines from microglial cells and inhibits

  2. Rod microglia: elongation, alignment, and coupling to form trains across the somatosensory cortex after experimental diffuse brain injury

    Directory of Open Access Journals (Sweden)

    Ziebell Jenna M

    2012-10-01

    Full Text Available Abstract Background Since their discovery, the morphology of microglia has been interpreted to mirror their function, with ramified microglia constantly surveying the micro-environment and rapidly activating when changes occur. In 1899, Franz Nissl discovered what we now recognize as a distinct microglial activation state, microglial rod cells (Stäbchenzellen, which he observed adjacent to neurons. These rod-shaped microglia are typically found in human autopsy cases of paralysis of the insane, a disease of the pre-penicillin era, and best known today from HIV-1-infected brains. Microglial rod cells have been implicated in cortical ‘synaptic stripping’ but their exact role has remained unclear. This is due at least in part to a scarcity of experimental models. Now we have noted these rod microglia after experimental diffuse brain injury in brain regions that have an associated sensory sensitivity. Here, we describe the time course, location, and surrounding architecture associated with rod microglia following experimental diffuse traumatic brain injury (TBI. Methods Rats were subjected to a moderate midline fluid percussion injury (mFPI, which resulted in transient suppression of their righting reflex (6 to 10 min. Multiple immunohistochemistry protocols targeting microglia with Iba1 and other known microglia markers were undertaken to identify the morphological activation of microglia. Additionally, labeling with Iba1 and cell markers for neurons and astrocytes identified the architecture that surrounds these rod cells. Results We identified an abundance of Iba1-positive microglia with rod morphology in the primary sensory barrel fields (S1BF. Although present for at least 4 weeks post mFPI, they developed over the first week, peaking at 7 days post-injury. In the absence of contusion, Iba1-positive microglia appear to elongate with their processes extending from the apical and basal ends. These cells then abut one another and lay adjacent

  3. Andrographolide - A promising therapeutic agent, negatively regulates glial cell derived neurodegeneration of prefrontal cortex, hippocampus and working memory impairment.

    Science.gov (United States)

    Das, Sudeshna; Mishra, K P; Ganju, Lilly; Singh, S B

    2017-12-15

    Over activation of glial cell derived innate immune factors induces neuro-inflammation that results in neurodegenerative disease, like working memory impairment. In this study, we have investigated the role of andrographolide, a major constituent of Andrographis paniculata plant, in reduction of reactive glial cell derived working memory impairment. Real time PCR, Western bloting, flow cytometric and immunofluorescence studies demonstrated that andrographolide inhibited lipopolysaccharide (LPS)-induced overexpression of HMGB1, TLR4, NFκB, COX-2, iNOS, and release of inflammatory mediators in primary mix glial culture, adult mice prefrontal cortex and hippocampus region. Active microglial and reactive astrocytic makers were also downregulated after andrographolide treatment. Andrographolide suppressed overexpression of microglial MIP-1α, P2X7 receptor and its downstream signaling mediators including-inflammasome NLRP3, caspase1 and mature IL-1β. Furthermore, in vivo maze studies suggested that andrographolide treatment reversed LPS-induced behavioural and working memory disturbances including regulation of expression of protein markers like PKC, p-CREB, amyloid beta, APP, p-tau, synapsin and PSD-95. Andrographolide, by lowering expression of pro apoptotic genes and enhancing the expression of anti-apoptotic gene showed its anti-apoptotic nature that in turn reduces neurodegeneration. Morphology studies using Nissl and FJB staining also showed the neuroprotective effect of andrographolide in the prefrontal cortex region. The above studies indicated that andrographolide prevented neuroinflammation-associated neurodegeneration and improved synaptic plasticity markers in cortical as well as hippocampal region which suggests that andrographolide could be a novel pharmacological countermeasure for the treatment of neuroinflammation and neurological disorders related to memory impairment. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Pathologic and Protective Roles for Microglial Subsets and Bone Marrow- and Blood-Derived Myeloid Cells in Central Nervous System Inflammation

    DEFF Research Database (Denmark)

    Wlodarczyk, Agnieszka; Cédile, Oriane; Jensen, Kirstine Nolling

    2015-01-01

    Inflammation is a series of processes designed for eventual clearance of pathogens and repair of damaged tissue. In the context of autoimmune recognition, inflammatory processes are usually considered to be pathological. This is also true for inflammatory responses in the central nervous system...... (CNS). However, as in other tissues, neuroinflammation can have beneficial as well as pathological outcomes. The complex role of encephalitogenic T cells in multiple sclerosis and its animal model experimental autoimmune encephalomyelitis (EAE) may derive from heterogeneity of the myeloid cells...... with which these T cells interact within the CNS. Myeloid cells, including resident microglia and infiltrating bone marrow-derived cells, such as dendritic cells (DC) and monocytes/macrophages [bone marrow-derived macrophages (BMDM)], are highly heterogeneous populations that may be involved in neurotoxicity...

  5. Liposomal clodronate selectively eliminates microglia from primary astrocyte cultures

    Directory of Open Access Journals (Sweden)

    Kumamaru Hiromi

    2012-05-01

    Full Text Available Abstract Background There is increasing interest in astrocyte biology because astrocytes have been demonstrated to play prominent roles in physiological and pathological conditions of the central nervous system, including neuroinflammation. To understand astrocyte biology, primary astrocyte cultures are most commonly used because of the direct accessibility of astrocytes in this system. However, this advantage can be hindered by microglial contamination. Although several authors have warned regarding microglial contamination in this system, complete microglial elimination has never been achieved. Methods The number and proliferative potential of contaminating microglia in primary astrocyte cultures were quantitatively assessed by immunocytologic and flow cytometric analyses. To examine the utility of clodronate for microglial elimination, primary astrocyte cultures or MG-5 cells were exposed to liposomal or free clodronate, and then immunocytologic, flow cytometric, and gene expression analyses were performed. The gene expression profiles of microglia-eliminated and microglia-contaminated cultures were compared after interleukin-6 (IL-6 stimulation. Results The percentage of contaminating microglia exceeded 15% and continued to increase because of their high proliferative activity in conventional primary astrocyte cultures. These contaminating microglia were selectively eliminated low concentration of liposomal clodronate. Although primary microglia and MG-5 cells were killed by both liposomal and free clodronate, free clodronate significantly affected the viability of astrocytes. In contrast, liposomal clodronate selectively eliminated microglia without affecting the viability, proliferation or activation of astrocytes. The efficacy of liposomal clodronate was much higher than that of previously reported methods used for decreasing microglial contamination. Furthermore, we observed rapid tumor necrosis factor-α and IL-1b gene induction in

  6. A Highly Efficient Human Pluripotent Stem Cell Microglia Model Displays a Neuronal-Co-culture-Specific Expression Profile and Inflammatory Response

    Directory of Open Access Journals (Sweden)

    Walther Haenseler

    2017-06-01

    Full Text Available Microglia are increasingly implicated in brain pathology, particularly neurodegenerative disease, with many genes implicated in Alzheimer's, Parkinson's, and motor neuron disease expressed in microglia. There is, therefore, a need for authentic, efficient in vitro models to study human microglial pathological mechanisms. Microglia originate from the yolk sac as MYB-independent macrophages, migrating into the developing brain to complete differentiation. Here, we recapitulate microglial ontogeny by highly efficient differentiation of embryonic MYB-independent iPSC-derived macrophages then co-culture them with iPSC-derived cortical neurons. Co-cultures retain neuronal maturity and functionality for many weeks. Co-culture microglia express key microglia-specific markers and neurodegenerative disease-relevant genes, develop highly dynamic ramifications, and are phagocytic. Upon activation they become more ameboid, releasing multiple microglia-relevant cytokines. Importantly, co-culture microglia downregulate pathogen-response pathways, upregulate homeostatic function pathways, and promote a more anti-inflammatory and pro-remodeling cytokine response than corresponding monocultures, demonstrating that co-cultures are preferable for modeling authentic microglial physiology.

  7. Protective Effect of Purple Sweet Potato (Ipomoea batatas Linn ...

    African Journals Online (AJOL)

    Purpose: To evaluate the protective effects of purple sweet potato (Ipomoea batatas Linn, Convolvulaceae) extract (IBE) in stimulated BV-2 microglial cells and its anti-oxidant properties. Methods: Cell viability assessment was performed by 3-(4, 5-dimethylthiazol-2-yl)-2, 5- diphenyltetrazolium bromide (MTT) assay.

  8. Recent Advances in the Study of Bipolar/Rod-Shaped Microglia and their Roles in Neurodegeneration

    Directory of Open Access Journals (Sweden)

    Ngan Pan Bennett Au

    2017-05-01

    Full Text Available Microglia are the resident immune cells of the central nervous system (CNS and they contribute to primary inflammatory responses following CNS injuries. The morphology of microglia is closely associated with their functional activities. Most previous research efforts have attempted to delineate the role of ramified and amoeboid microglia in the pathogenesis of neurodegenerative diseases. In addition to ramified and amoeboid microglia, bipolar/rod-shaped microglia were first described by Franz Nissl in 1899 and their presence in the brain was closely associated with the pathology of infectious diseases and sleeping disorders. However, studies relating to bipolar/rod-shaped microglia are very limited, largely due to the lack of appropriate in vitro and in vivo experimental models. Recent studies have reported the formation of bipolar/rod-shaped microglia trains in in vivo models of CNS injury, including diffuse brain injury, focal transient ischemia, optic nerve transection and laser-induced ocular hypertension (OHT. These bipolar/rod-shaped microglia formed end-to-end alignments in close proximity to the adjacent injured axons, but they showed no interactions with blood vessels or other types of glial cell. Recent studies have also reported on a highly reproducible in vitro culture model system to enrich bipolar/rod-shaped microglia that acts as a powerful tool with which to characterize this form of microglia. The molecular aspects of bipolar/rod-shaped microglia are of great interest in the field of CNS repair. This review article focuses on studies relating to the morphology and transformation of microglia into the bipolar/rod-shaped form, along with the differential gene expression and spatial distribution of bipolar/rod-shaped microglia in normal and pathological CNSs. The spatial arrangement of bipolar/rod-shaped microglia is crucial in the reorganization and remodeling of neuronal and synaptic circuitry following CNS injuries. Finally, we

  9. HIV-1 gp120 Upregulates Brain-Derived Neurotrophic Factor (BDNF) Expression in BV2 Cells via the Wnt/β-Catenin Signaling Pathway.

    Science.gov (United States)

    Wang, Yongdi; Liao, Jinxu; Tang, Shao-Jun; Shu, Jianhong; Zhang, Wenping

    2017-06-01

    HIV-1 gp120 plays a critical role in the pathogenesis of HIV-associated pain, but the underlying molecular mechanisms are incompletely understood. This study aims to determine the effect and possible mechanism of HIV-1 gp120 on BDNF expression in BV2 cells (a murine-derived microglial cell line). We observed that gp120 (10 ng/ml) activated BV2 cells in cultures and upregulated proBDNF/mBDNF. Furthermore, gp120-treated BV2 also accumulated Wnt3a and β-catenin, suggesting the activation of the Wnt/β-catenin pathway. We demonstrated that activation of the pathway by Wnt3a upregulated BDNF expression. In contrast, inhibition of the Wnt/β-catenin pathway by either DKK1 or IWR-1 attenuated BDNF upregulation induced by gp120 or Wnt3a. These findings collectively suggest that gp120 stimulates BDNF expression in BV2 cells via the Wnt/β-catenin signaling pathway.

  10. Brain-derived neurotrophic factor (BDNF) induces sustained intracellular Ca2+ elevation through the up-regulation of surface transient receptor potential 3 (TRPC3) channels in rodent microglia.

    Science.gov (United States)

    Mizoguchi, Yoshito; Kato, Takahiro A; Seki, Yoshihiro; Ohgidani, Masahiro; Sagata, Noriaki; Horikawa, Hideki; Yamauchi, Yusuke; Sato-Kasai, Mina; Hayakawa, Kohei; Inoue, Ryuji; Kanba, Shigenobu; Monji, Akira

    2014-06-27

    Microglia are immune cells that release factors, including proinflammatory cytokines, nitric oxide (NO), and neurotrophins, following activation after disturbance in the brain. Elevation of intracellular Ca(2+) concentration ([Ca(2+)]i) is important for microglial functions such as the release of cytokines and NO from activated microglia. There is increasing evidence suggesting that pathophysiology of neuropsychiatric disorders is related to the inflammatory responses mediated by microglia. Brain-derived neurotrophic factor (BDNF) is a neurotrophin well known for its roles in the activation of microglia as well as in pathophysiology and/or treatment of neuropsychiatric disorders. In this study, we sought to examine the underlying mechanism of BDNF-induced sustained increase in [Ca(2+)]i in rodent microglial cells. We observed that canonical transient receptor potential 3 (TRPC3) channels contribute to the maintenance of BDNF-induced sustained intracellular Ca(2+) elevation. Immunocytochemical technique and flow cytometry also revealed that BDNF rapidly up-regulated the surface expression of TRPC3 channels in rodent microglial cells. In addition, pretreatment with BDNF suppressed the production of NO induced by tumor necrosis factor α (TNFα), which was prevented by co-adiministration of a selective TRPC3 inhibitor. These suggest that BDNF induces sustained intracellular Ca(2+) elevation through the up-regulation of surface TRPC3 channels and TRPC3 channels could be important for the BDNF-induced suppression of the NO production in activated microglia. We show that TRPC3 channels could also play important roles in microglial functions, which might be important for the regulation of inflammatory responses and may also be involved in the pathophysiology and/or the treatment of neuropsychiatric disorders. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  11. Bioluminescent system for dynamic imaging of cell and animal behavior

    Energy Technology Data Exchange (ETDEWEB)

    Hara-Miyauchi, Chikako [Department of Physiology, Keio University School of Medicine, Tokyo 160-8582 (Japan); Laboratory for Cell Function Dynamics, Brain Science Institute, RIKEN, Saitama 351-0198 (Japan); Department of Biophysics and Biochemistry, Graduate School of Health Care Sciences, Tokyo Medical and Dental University, Tokyo 113-8510 (Japan); Tsuji, Osahiko [Department of Physiology, Keio University School of Medicine, Tokyo 160-8582 (Japan); Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo 160-8582 (Japan); Hanyu, Aki [Division of Biochemistry, The Cancer Institute of the Japanese Foundation for Cancer Research, Tokyo 135-8550 (Japan); Okada, Seiji [Department of Advanced Medical Initiatives, Faculty of Medical Sciences, Kyushu University, Fukuoka 812-8582 (Japan); Yasuda, Akimasa [Department of Physiology, Keio University School of Medicine, Tokyo 160-8582 (Japan); Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo 160-8582 (Japan); Fukano, Takashi [Laboratory for Cell Function Dynamics, Brain Science Institute, RIKEN, Saitama 351-0198 (Japan); Akazawa, Chihiro [Department of Biophysics and Biochemistry, Graduate School of Health Care Sciences, Tokyo Medical and Dental University, Tokyo 113-8510 (Japan); Nakamura, Masaya [Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo 160-8582 (Japan); Imamura, Takeshi [Department of Molecular Medicine for Pathogenesis, Ehime University Graduate School of Medicine, Toon, Ehime 791-0295 (Japan); Core Research for Evolutional Science and Technology, The Japan Science and Technology Corporation, Tokyo 135-8550 (Japan); Matsuzaki, Yumi [Department of Physiology, Keio University School of Medicine, Tokyo 160-8582 (Japan); Okano, Hirotaka James, E-mail: hjokano@jikei.ac.jp [Department of Physiology, Keio University School of Medicine, Tokyo 160-8582 (Japan); Division of Regenerative Medicine Jikei University School of Medicine, Tokyo 150-8461 (Japan); and others

    2012-03-09

    Highlights: Black-Right-Pointing-Pointer We combined a yellow variant of GFP and firefly luciferase to make ffLuc-cp156. Black-Right-Pointing-Pointer ffLuc-cp156 showed improved photon yield in cultured cells and transgenic mice. Black-Right-Pointing-Pointer ffLuc-cp156 enabled video-rate bioluminescence imaging of freely-moving animals. Black-Right-Pointing-Pointer ffLuc-cp156 mice enabled tracking real-time drug delivery in conscious animals. -- Abstract: The current utility of bioluminescence imaging is constrained by a low photon yield that limits temporal sensitivity. Here, we describe an imaging method that uses a chemiluminescent/fluorescent protein, ffLuc-cp156, which consists of a yellow variant of Aequorea GFP and firefly luciferase. We report an improvement in photon yield by over three orders of magnitude over current bioluminescent systems. We imaged cellular movement at high resolution including neuronal growth cones and microglial cell protrusions. Transgenic ffLuc-cp156 mice enabled video-rate bioluminescence imaging of freely moving animals, which may provide a reliable assay for drug distribution in behaving animals for pre-clinical studies.

  12. Bioluminescent system for dynamic imaging of cell and animal behavior

    International Nuclear Information System (INIS)

    Hara-Miyauchi, Chikako; Tsuji, Osahiko; Hanyu, Aki; Okada, Seiji; Yasuda, Akimasa; Fukano, Takashi; Akazawa, Chihiro; Nakamura, Masaya; Imamura, Takeshi; Matsuzaki, Yumi; Okano, Hirotaka James

    2012-01-01

    Highlights: ► We combined a yellow variant of GFP and firefly luciferase to make ffLuc-cp156. ► ffLuc-cp156 showed improved photon yield in cultured cells and transgenic mice. ► ffLuc-cp156 enabled video-rate bioluminescence imaging of freely-moving animals. ► ffLuc-cp156 mice enabled tracking real-time drug delivery in conscious animals. -- Abstract: The current utility of bioluminescence imaging is constrained by a low photon yield that limits temporal sensitivity. Here, we describe an imaging method that uses a chemiluminescent/fluorescent protein, ffLuc-cp156, which consists of a yellow variant of Aequorea GFP and firefly luciferase. We report an improvement in photon yield by over three orders of magnitude over current bioluminescent systems. We imaged cellular movement at high resolution including neuronal growth cones and microglial cell protrusions. Transgenic ffLuc-cp156 mice enabled video-rate bioluminescence imaging of freely moving animals, which may provide a reliable assay for drug distribution in behaving animals for pre-clinical studies.

  13. Salicornia bigelovii Torr Attenuates Neuro-Inflammatory Responses ...

    African Journals Online (AJOL)

    Konkuk University, 2KuGen Healthcare Institute, Konkuk University Business ... BV- microglial cells were stimulated with LPS to study the protein expression and production of inflammatory mediators, determined by Western blot analysis.

  14. The Interplay between Cyclic AMP, MAPK, and NF-κB Pathways in Response to Proinflammatory Signals in Microglia

    Directory of Open Access Journals (Sweden)

    Mousumi Ghosh

    2015-01-01

    Full Text Available Cyclic AMP is an important intracellular regulator of microglial cell homeostasis and its negative perturbation through proinflammatory signaling results in microglial cell activation. Though cytokines, TNF-α and IL-1β, decrease intracellular cyclic AMP, the mechanism by which this occurs is poorly understood. The current study examined which signaling pathways are responsible for decreasing cyclic AMP in microglia following TNF-α stimulation and sought to identify the role cyclic AMP plays in regulating these pathways. In EOC2 microglia, TNF-α produced a dramatic reduction in cyclic AMP and increased cyclic AMP-dependent PDE activity that could be antagonized by Rolipram, myristoylated-PKI, PD98059, or JSH-23, implicating a role for PDE4, PKA, MEK, and NF-κB in this regulation. Following TNF-α there were significant increases in iNOS and COX-2 immunoreactivity, phosphorylated ERK1/2 and NF-κB-p65, IκB degradation, and NF-κB p65 nuclear translocation, which were reduced in the presence of high levels of cyclic AMP, indicating that reductions in cyclic AMP during cytokine stimulation are important for removing its inhibitory action on NF-κB activation and subsequent proinflammatory gene expression. Further elucidation of the signaling crosstalk involved in decreasing cyclic AMP in response to inflammatory signals may provide novel therapeutic targets for modulating microglial cell activation during neurological injury and disease.

  15. Microglia Polarization, Gene-Environment Interactions and Wnt/β-Catenin Signaling: Emerging Roles of Glia-Neuron and Glia-Stem/Neuroprogenitor Crosstalk for Dopaminergic Neurorestoration in Aged Parkinsonian Brain

    Directory of Open Access Journals (Sweden)

    Francesca L'Episcopo

    2018-02-01

    Full Text Available Neuroinflammatory processes are recognized key contributory factors in Parkinson's disease (PD physiopathology. While the causes responsible for the progressive loss of midbrain dopaminergic (mDA neuronal cell bodies in the subtantia nigra pars compacta are poorly understood, aging, genetics, environmental toxicity, and particularly inflammation, represent prominent etiological factors in PD development. Especially, reactive astrocytes, microglial cells, and infiltrating monocyte-derived macrophages play dual beneficial/harmful effects, via a panel of pro- or anti-inflammatory cytokines, chemokines, neurotrophic and neurogenic transcription factors. Notably, with age, microglia may adopt a potent neurotoxic, pro-inflammatory “primed” (M1 phenotype when challenged with inflammatory or neurotoxic stimuli that hamper brain's own restorative potential and inhibit endogenous neurorepair mechanisms. In the last decade we have provided evidence for a major role of microglial crosstalk with astrocytes, mDA neurons and neural stem progenitor cells (NSCs in the MPTP- (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine- mouse model of PD, and identified Wnt/β-catenin signaling, a pivotal morphogen for mDA neurodevelopment, neuroprotection, and neuroinflammatory modulation, as a critical actor in glia-neuron and glia-NSCs crosstalk. With age however, Wnt signaling and glia-NSC-neuron crosstalk become dysfunctional with harmful consequences for mDA neuron plasticity and repair. These findings are of importance given the deregulation of Wnt signaling in PD and the emerging link between most PD related genes, Wnt signaling and inflammation. Especially, in light of the expanding field of microRNAs and inflammatory PD-related genes as modulators of microglial-proinflammatory status, uncovering the complex molecular circuitry linking PD and neuroinflammation will permit the identification of new druggable targets for the cure of the disease. Here we summarize

  16. Astrocyte-targeted expression of interleukin-3 and interferon-alpha causes region-specific changes in metallothionein expression in the brain

    DEFF Research Database (Denmark)

    Giralt, M; Carrasco, J; Penkowa, M

    2001-01-01

    Transgenic mice expressing IL-3 and IFN-alpha under the regulatory control of the GFAP gene promoter (GFAP-IL3 and GFAP-IFNalpha mice) exhibit a cytokine-specific, late-onset chronic-progressive neurological disorder which resemble many of the features of human diseases such as multiple sclerosis...... was confirmed by immunohistochemistry. MT-III immunoreactivity was present in cells that were mainly round or amoeboid monocytes/macrophages and in astrocytes. MT-I+II induction was more generalized in the GFAP-IFNalpha (GIFN12 and GIFN39 lines) mice, with significant increases in the cerebellum, thalamus...

  17. Effectors of Th1 and Th17 cells act on astrocytes and augment their neuroinflammatory properties

    DEFF Research Database (Denmark)

    Prajeeth, Chittappen K; Kronisch, Julius; Khorooshi, Reza M. H.

    2017-01-01

    Background: Autoreactive Th1 and Th17 cells are believed to mediate the pathology of multiple sclerosis in the central nervous system (CNS). Their interaction with microglia and astrocytes in the CNS is crucial for the regulation of the neuroinflammation. Previously we have shown that only Th1...... mice where trafficking of Th1 cells into the CNS was affected. We compared microglia and astrocyte response in the brain and spinal cord of these mice. We further treated astrocytes with supernatants from highly pure Th1 and Th17 cultures and assessed the mRNA expression of neurotrophic factors......, cytokines and chemokines using real-time PCR. Data obtained was analysed using Kruskal- Wallis test. Results: We observed in α4-deficient mice weak microglial activation but comparable astrogliosis to that of wild-type mice in the regions of the brain populated with Th17 infiltrates suggesting that Th17...

  18. Microglial cell dysregulation in brain aging and neurodegeneration

    OpenAIRE

    von Bernhardi, Rommy; Eugen?n-von Bernhardi, Laura; Eugen?n, Jaime

    2015-01-01

    Aging is the main risk factor for neurodegenerative diseases. In aging, microglia undergoes phenotypic changes compatible with their activation. Glial activation can lead to neuroinflammation, which is increasingly accepted as part of the pathogenesis of neurodegenerative diseases, including Alzheimer’s disease (AD). We hypothesize that in aging, aberrant microglia activation leads to a deleterious environment and neurodegeneration. In aged mice, microglia exhibit an increased expression of c...

  19. A novel anti-inflammatory role of NCAM-derived mimetic peptide, FGL

    DEFF Research Database (Denmark)

    Downer, Eric J; Cowley, Thelma R; Lyons, Anthony

    2010-01-01

    as a novel anti-inflammatory agent. Administration of FGL to aged rats attenuated the increased expression of markers of activated microglia, the increase in pro-inflammatory interleukin-1beta (IL-1beta) and the impairment in long-term potentiation (LTP). We report that the age-related increase in microglial...... activation was accompanied by decreased expression of neuronal CD200, and suggest that the proclivity of FGL to suppress microglial activation is due to its stimulatory effect on neuronal CD200. We demonstrate that FGL enhanced interleukin-4 (IL-4) release from glial cells and IL-4 in turn enhanced neuronal...

  20. Fractalkine/CX3CL1 protects striatal neurons from synergistic morphine and HIV-1 Tat-induced dendritic losses and death

    Directory of Open Access Journals (Sweden)

    Suzuki Masami

    2011-11-01

    Full Text Available Abstract Background Fractalkine/CX3CL1 and its cognate receptor CX3CR1 are abundantly expressed in the CNS. Fractalkine is an unusual C-X3-C motif chemokine that is important in neuron-microglial communication, a co-receptor for HIV infection, and can be neuroprotective. To assess the effects of fractalkine on opiate-HIV interactive neurotoxicity, wild-type murine striatal neurons were co-cultured with mixed glia from the striata of wild-type or Cx3cr1 knockout mice ± HIV-1 Tat and/or morphine. Time-lapse digital images were continuously recorded at 20 min intervals for up to 72 h using computer-aided microscopy to track the same cells repeatedly. Results Co-exposure to Tat and morphine caused synergistic increases in neuron death, dendritic pruning, and microglial motility as previously reported. Exogenous fractalkine prevented synergistic Tat and morphine-induced dendritic losses and neuron death even though the inflammatory mediator TNF-α remained significantly elevated. Antibody blockade of CX3CR1 mimicked the toxic effects of morphine plus Tat, but did not add to their toxicity; while fractalkine failed to protect wild-type neurons co-cultured with Cx3cr1-/--null glia against morphine and Tat toxicity. Exogenous fractalkine also normalized microglial motility, which is elevated by Tat and morphine co-exposure, presumably limiting microglial surveillance that may lead to toxic effects on neurons. Fractalkine immunofluorescence was expressed in neurons and to a lesser extent by other cell types, whereas CX3CR1 immunoreactivity or GFP fluorescence in cells cultured from the striatum of Cx3cr1-/- (Cx3cr1GFP/GFP mice were associated with microglia. Immunoblotting shows that fractalkine levels were unchanged following Tat and/or morphine exposure and there was no increase in released fractalkine as determined by ELISA. By contrast, CX3CR1 protein levels were markedly downregulated. Conclusions The results suggest that deficits in fractalkine

  1. Inhibition of Nitric Oxide and Prostaglandin E 2 Expression by ...

    African Journals Online (AJOL)

    Inhibition of Nitric Oxide and Prostaglandin E 2 Expression by Methanol Extract of Polyopes affinis in Lipopolysaccharide-stimulated BV2 Microglial Cells through Suppression of Akt-dependent NF-kB Activity and MAPK Pathway.

  2. Dendritic cells and anergic type I NKT cells play a crucial role in sulfatide-mediated immune regulation in experimental autoimmune encephalomyelitis.

    Science.gov (United States)

    Maricic, Igor; Halder, Ramesh; Bischof, Felix; Kumar, Vipin

    2014-08-01

    CD1d-restricted NKT cells can be divided into two groups: type I NKT cells use a semi-invariant TCR, whereas type II express a relatively diverse set of TCRs. A major subset of type II NKT cells recognizes myelin-derived sulfatides and is selectively enriched in the CNS tissue during experimental autoimmune encephalomyelitis (EAE). We have shown that activation of sulfatide-reactive type II NKT cells by sulfatide prevents induction of EAE. In this article, we have addressed the mechanism of regulation, as well as whether a single immunodominant form of synthetic sulfatide can treat ongoing chronic and relapsing EAE in SJL/J mice. We have shown that the activation of sulfatide-reactive type II NKT cells leads to a significant reduction in the frequency and effector function of myelin proteolipid proteins 139-151/I-A(s)-tetramer(+) cells in lymphoid and CNS tissues. In addition, type I NKT cells and dendritic cells (DCs) in the periphery, as well as CNS-resident microglia, are inactivated after sulfatide administration, and mice deficient in type I NKT cells are not protected from disease. Moreover, tolerized DCs from sulfatide-treated animals can adoptively transfer protection into naive mice. Treatment of SJL/J mice with a synthetic cis-tetracosenoyl sulfatide, but not α-galactosylceramide, reverses ongoing chronic and relapsing EAE. Our data highlight a novel immune-regulatory pathway involving NKT subset interactions leading to inactivation of type I NKT cells, DCs, and microglial cells in suppression of autoimmunity. Because CD1 molecules are nonpolymorphic, the sulfatide-mediated immune-regulatory pathway can be targeted for development of non-HLA-dependent therapeutic approaches to T cell-mediated autoimmune diseases. Copyright © 2014 by The American Association of Immunologists, Inc.

  3. An mDia2/ROCK signaling axis regulates invasive egress from epithelial ovarian cancer spheroids.

    Science.gov (United States)

    Pettee, Krista M; Dvorak, Kaitlyn M; Nestor-Kalinoski, Andrea L; Eisenmann, Kathryn M

    2014-01-01

    Multi-cellular spheroids are enriched in ascites of epithelial ovarian cancer (OvCa) patients. They represent an invasive and chemoresistant cellular population fundamental to metastatic dissemination. The molecular mechanisms triggering single cell invasive egress from spheroids remain enigmatic. mDia formins are Rho GTPase effectors that are key regulators of F-actin cytoskeletal dynamics. We hypothesized that mDia2-driven F-actin dynamics promote single cell invasive transitions in clinically relevant three-dimensional (3D) OvCa spheroids. The current study is a dissection of the contribution of the F-actin assembly factor mDia2 formin in invasive transitions and using a clinically relevant ovarian cancer spheroid model. We show that RhoA-directed mDia2 activity is required for tight spheroid organization, and enrichment of mDia2 in the invasive cellular protrusions of collagen-embedded OVCA429 spheroids. Depleting mDia2 in ES-2 spheroids enhanced invasive dissemination of single amoeboid-shaped cells. This contrasts with spheroids treated with control siRNA, where a mesenchymal invasion program predominated. Inhibition of another RhoA effector, ROCK, had no impact on ES-2 spheroid formation but dramatically inhibited spheroid invasion through induction of a highly elongated morphology. Concurrent inhibition of ROCK and mDia2 blocked single cell invasion from ES-2 spheroids more effectively than inhibition of either protein alone, indicating that invasive egress of amoeboid cells from mDia2-depleted spheroids is ROCK-dependent. Our findings indicate that multiple GTPase effectors must be suppressed in order to fully block invasive egress from ovarian cancer spheroids. Furthermore, tightly regulated interplay between ROCK and mDia2 signaling pathways dictates the invasive capacities and the type of invasion program utilized by motile spheroid-derived ovarian cancer cells. As loss of the gene encoding mDia2, DRF3, has been linked to cancer progression and

  4. An mDia2/ROCK signaling axis regulates invasive egress from epithelial ovarian cancer spheroids.

    Directory of Open Access Journals (Sweden)

    Krista M Pettee

    Full Text Available Multi-cellular spheroids are enriched in ascites of epithelial ovarian cancer (OvCa patients. They represent an invasive and chemoresistant cellular population fundamental to metastatic dissemination. The molecular mechanisms triggering single cell invasive egress from spheroids remain enigmatic. mDia formins are Rho GTPase effectors that are key regulators of F-actin cytoskeletal dynamics. We hypothesized that mDia2-driven F-actin dynamics promote single cell invasive transitions in clinically relevant three-dimensional (3D OvCa spheroids. The current study is a dissection of the contribution of the F-actin assembly factor mDia2 formin in invasive transitions and using a clinically relevant ovarian cancer spheroid model. We show that RhoA-directed mDia2 activity is required for tight spheroid organization, and enrichment of mDia2 in the invasive cellular protrusions of collagen-embedded OVCA429 spheroids. Depleting mDia2 in ES-2 spheroids enhanced invasive dissemination of single amoeboid-shaped cells. This contrasts with spheroids treated with control siRNA, where a mesenchymal invasion program predominated. Inhibition of another RhoA effector, ROCK, had no impact on ES-2 spheroid formation but dramatically inhibited spheroid invasion through induction of a highly elongated morphology. Concurrent inhibition of ROCK and mDia2 blocked single cell invasion from ES-2 spheroids more effectively than inhibition of either protein alone, indicating that invasive egress of amoeboid cells from mDia2-depleted spheroids is ROCK-dependent. Our findings indicate that multiple GTPase effectors must be suppressed in order to fully block invasive egress from ovarian cancer spheroids. Furthermore, tightly regulated interplay between ROCK and mDia2 signaling pathways dictates the invasive capacities and the type of invasion program utilized by motile spheroid-derived ovarian cancer cells. As loss of the gene encoding mDia2, DRF3, has been linked to cancer

  5. Primary microglia isolation from mixed glial cell cultures of neonatal rat brain tissue.

    Science.gov (United States)

    Tamashiro, Tami T; Dalgard, Clifton Lee; Byrnes, Kimberly R

    2012-08-15

    Microglia account for approximately 12% of the total cellular population in the mammalian brain. While neurons and astrocytes are considered the major cell types of the nervous system, microglia play a significant role in normal brain physiology by monitoring tissue for debris and pathogens and maintaining homeostasis in the parenchyma via phagocytic activity. Microglia are activated during a number of injury and disease conditions, including neurodegenerative disease, traumatic brain injury, and nervous system infection. Under these activating conditions, microglia increase their phagocytic activity, undergo morpohological and proliferative change, and actively secrete reactive oxygen and nitrogen species, pro-inflammatory chemokines and cytokines, often activating a paracrine or autocrine loop. As these microglial responses contribute to disease pathogenesis in neurological conditions, research focused on microglia is warranted. Due to the cellular heterogeneity of the brain, it is technically difficult to obtain sufficient microglial sample material with high purity during in vivo experiments. Current research on the neuroprotective and neurotoxic functions of microglia require a routine technical method to consistently generate pure and healthy microglia with sufficient yield for study. We present, in text and video, a protocol to isolate pure primary microglia from mixed glia cultures for a variety of downstream applications. Briefly, this technique utilizes dissociated brain tissue from neonatal rat pups to produce mixed glial cell cultures. After the mixed glial cultures reach confluency, primary microglia are mechanically isolated from the culture by a brief duration of shaking. The microglia are then plated at high purity for experimental study. The principle and protocol of this methodology have been described in the literature. Additionally, alternate methodologies to isolate primary microglia are well described. Homogenized brain tissue may be separated

  6. Mesenchymal stem cells induce T-cell tolerance and protect the preterm brain after global hypoxia-ischemia.

    Directory of Open Access Journals (Sweden)

    Reint K Jellema

    Full Text Available Hypoxic-ischemic encephalopathy (HIE in preterm infants is a severe disease for which no curative treatment is available. Cerebral inflammation and invasion of activated peripheral immune cells have been shown to play a pivotal role in the etiology of white matter injury, which is the clinical hallmark of HIE in preterm infants. The objective of this study was to assess the neuroprotective and anti-inflammatory effects of intravenously delivered mesenchymal stem cells (MSC in an ovine model of HIE. In this translational animal model, global hypoxia-ischemia (HI was induced in instrumented preterm sheep by transient umbilical cord occlusion, which closely mimics the clinical insult. Intravenous administration of 2 x 10(6 MSC/kg reduced microglial proliferation, diminished loss of oligodendrocytes and reduced demyelination, as determined by histology and Diffusion Tensor Imaging (DTI, in the preterm brain after global HI. These anti-inflammatory and neuroprotective effects of MSC were paralleled by reduced electrographic seizure activity in the ischemic preterm brain. Furthermore, we showed that MSC induced persistent peripheral T-cell tolerance in vivo and reduced invasion of T-cells into the preterm brain following global HI. These findings show in a preclinical animal model that intravenously administered MSC reduced cerebral inflammation, protected against white matter injury and established functional improvement in the preterm brain following global HI. Moreover, we provide evidence that induction of T-cell tolerance by MSC might play an important role in the neuroprotective effects of MSC in HIE. This is the first study to describe a marked neuroprotective effect of MSC in a translational animal model of HIE.

  7. Attenuation of Neuroinflammatory Responses in Lipopolysaccharide ...

    African Journals Online (AJOL)

    Chenopodiaceae) extract on neuroinflammatory responses induced by lipopolysaccharide (LPS) in BV-2 microglial cells and its antioxidant effects. Methods: Biochemical studies carried out include 3-(4, 5-dimethylthiazol-2-yl)-2, 5- diphenyl-tetrazolium ...

  8. Focal Thalamic Degeneration from Ethanol and Thiamine Deficiency is Associated with Neuroimmune Gene Induction, Microglial Activation, and Lack of Monocarboxylic Acid Transporters

    Science.gov (United States)

    Qin, Liya; Crews, Fulton T

    2014-01-01

    Background Wernicke's encephalopathy-Korsakoff syndrome (WE-KS) is common in alcoholics, caused by thiamine deficiency (TD; vitamin B1) and associated with lesions to the thalamus (THAL). Although TD alone can cause WE, the high incidence in alcoholism suggests that TD and ethanol (EtOH) interact. Methods Mice in control, TD, or EtOH groups alone or combined were studied after 5 or 10 days of treatment. THAL and entorhinal cortex (ENT) histochemistry and mRNA were assessed. Results Combined EtOH-TD treatment for 5 days (EtOH-TD5) showed activated microglia, proinflammatory gene induction and THAL neurodegeneration that was greater than that found with TD alone (TD5), whereas 10 days resulted in marked THAL degeneration and microglial-neuroimmune activation in both groups. In contrast, 10 days of TD did not cause ENT degeneration. Interestingly, in ENT, TD10 activated microglia and astrocytes more than EtOH-TD10. In THAL, multiple astrocytic markers were lost consistent with glial cell loss. TD blocks glucose metabolism more than acetate. Acetate derived from hepatic EtOH metabolism is transported by monocarboxylic acid transporters (MCT) into both neurons and astrocytes that use acetyl-CoA synthetase (AcCoAS) to generate cellular energy from acetate. MCT and AcCoAS expression in THAL is lower than ENT prompting the hypothesis that focal THAL degeneration is related to insufficient MCT and AcCoAS in THAL. To test this hypothesis, we administered glycerin triacetate (GTA) to increase blood acetate and found it protected the THAL from TD-induced degeneration. Conclusions Our findings suggest that EtOH potentiates TD-induced THAL degeneration through neuroimmune gene induction. The findings support the hypothesis that TD deficiency inhibits global glucose metabolism and that a reduced ability to process acetate for cellular energy results in THAL focal degeneration in alcoholics contributing to the high incidence of Wernicke-Korsakoff syndrome in alcoholism. PMID

  9. Agonists for G-protein-coupled receptor 84 (GPR84) alter cellular morphology and motility but do not induce pro-inflammatory responses in microglia.

    Science.gov (United States)

    Wei, Li; Tokizane, Kyohei; Konishi, Hiroyuki; Yu, Hua-Rong; Kiyama, Hiroshi

    2017-10-03

    Several G-protein-coupled receptors (GPCRs) have been shown to be important signaling mediators between neurons and glia. In our previous screening for identification of nerve injury-associated GPCRs, G-protein-coupled receptor 84 (GPR84) mRNA showed the highest up-regulation by microglia after nerve injury. GPR84 is a pro-inflammatory receptor of macrophages in a neuropathic pain mouse model, yet its function in resident microglia in the central nervous system is poorly understood. We used endogenous, natural, and surrogate agonists for GPR84 (capric acid, embelin, and 6-OAU, respectively) and examined their effect on mouse primary cultured microglia in vitro. 6-n-Octylaminouracil (6-OAU), embelin, and capric acid rapidly induced membrane ruffling and motility in cultured microglia obtained from C57BL/6 mice, although these agonists failed to promote microglial pro-inflammatory cytokine expression. Concomitantly, 6-OAU suppressed forskolin-induced increase of cAMP in cultured microglia. Pertussis toxin, an inhibitor of Gi-coupled signaling, completely suppressed 6-OAU-induced microglial membrane ruffling and motility. In contrast, no 6-OAU-induced microglial membrane ruffling and motility was observed in microglia from DBA/2 mice, a mouse strain that does not express functional GPR84 protein due to endogenous nonsense mutation of the GPR84 gene. GPR84 mediated signaling causes microglial motility and membrane ruffling but does not promote pro-inflammatory responses. As GPR84 is a known receptor for medium-chain fatty acids, those released from damaged brain cells may be involved in the enhancement of microglial motility through GPR84 after neuronal injury.

  10. Aging-Dependent Changes in the Radiation Response of the Adult Rat Brain

    International Nuclear Information System (INIS)

    Schindler, Matthew K.; Forbes, M. Elizabeth; Robbins, Mike E.; Riddle, David R.

    2008-01-01

    Purpose: To assess the impact of aging on the radiation response in the adult rat brain. Methods and Materials: Male rats 8, 18, or 28 months of age received a single 10-Gy dose of whole-brain irradiation (WBI). The hippocampal dentate gyrus was analyzed 1 and 10 weeks later for sensitive neurobiologic markers associated with radiation-induced damage: changes in density of proliferating cells, immature neurons, total microglia, and activated microglia. Results: A significant decrease in basal levels of proliferating cells and immature neurons and increased microglial activation occurred with normal aging. The WBI induced a transient increase in proliferation that was greater in older animals. This proliferation response did not increase the number of immature neurons, which decreased after WBI in young rats, but not in old rats. Total microglial numbers decreased after WBI at all ages, but microglial activation increased markedly, particularly in older animals. Conclusions: Age is an important factor to consider when investigating the radiation response of the brain. In contrast to young adults, older rats show no sustained decrease in number of immature neurons after WBI, but have a greater inflammatory response. The latter may have an enhanced role in the development of radiation-induced cognitive dysfunction in older individuals

  11. Minocycline Enhances the Effectiveness of Nociceptin/Orphanin FQ during Neuropathic Pain

    Directory of Open Access Journals (Sweden)

    Katarzyna Popiolek-Barczyk

    2014-01-01

    Full Text Available Nociceptin/orphanin FQ (N/OFQ antinociception, which is mediated selectively by the N/OFQ peptide receptor (NOP, was demonstrated in pain models. In this study, we determine the role of activated microglia on the analgesic effects of N/OFQ in a rat model of neuropathic pain induced by chronic constriction injury (CCI to the sciatic nerve. Repeated 7-day administration of minocycline (30 mg/kg i.p., a drug that affects microglial activation, significantly reduced pain in CCI-exposed rats and it potentiates the analgesic effects of administered N/OFQ (2.5–5 μg i.t.. Minocycline also downregulates the nerve injury-induced upregulation of NOP protein in the dorsal lumbar spinal cord. Our in vitro study showed that minocycline reduced NOP mRNA, but not protein, level in rat primary microglial cell cultures. In [35S]GTPγS binding assays we have shown that minocycline increases the spinal N/OFQ-stimulated NOP signaling. We suggest that the modulation of the N/OFQ system by minocycline is due to the potentiation of its neuronal antinociceptive activity and weakening of the microglial cell activation. This effect is beneficial for pain relief, and these results suggest new targets for the development of drugs that are effective against neuropathic pain.

  12. Regulatory T Cells in Post-stroke Immune Homeostasis.

    Science.gov (United States)

    Liesz, Arthur; Kleinschnitz, Christoph

    2016-08-01

    The secondary neuroinflammatory response has come into focus of experimental stroke research. Immunological mechanisms after acute stroke are being investigated in the hope to identify novel and druggable pathways that contribute to secondary infarct growth after stroke. Among a variety of neuroimmunological events after acute brain ischemia, including microglial activation, brain leukocyte invasion, and secretion of pro-inflammatory factors, lymphocytes have been identified as the key leukocyte subpopulation driving the neuroinflammatory response and contributing to stroke outcome. Several studies have shown that pro-inflammatory lymphocyte subpopulations worsen stroke outcome and that inhibiting their invasion to the injured brain is neuroprotective. In contrast to the effector functions of pro-inflammatory lymphocytes, regulatory T cells (Treg) are critically involved in maintaining immune homeostasis and have been characterized as disease-limiting protective cells in several inflammatory conditions, particularly in primary inflammatory diseases of the central nervous system (CNS). However, due to the complex function of regulatory cells in immune homeostasis and disease, divergent findings have been described for the role of Treg in stroke models. Emerging evidence suggests that this discrepancy arises from potentially differing functions of Treg depending on the predominant site of action within the neurovascular unit and the surrounding inflammatory milieu. This article will provide a comprehensive review of current findings on Treg in brain ischemia models and discuss potential reasons for the observed discrepancies.

  13. HIV-1 Tat C-mediated regulation of tumor necrosis factor receptor-associated factor-3 by microRNA 32 in human microglia

    Directory of Open Access Journals (Sweden)

    Mishra Ritu

    2012-06-01

    Full Text Available Abstract Background HIV-1 Tat protein is known to be associated with neuroinflammation, a condition that develops in almost half of patients infected with HIV-1. HIV-1 Tat can alter glial neuroprotective functions, leading to neurotoxicity within the CNS. HIV-1 Tat is known to be secreted from productively infected cells and can affect neighboring uninfected cells by modulating cellular gene expression in a bystander fashion. Methods We were interested to study whether exogenous exposure to HIV-1 Tat-C protein perturbs the microRNA (miRNA expression profile of human microglial cells, leading to altered protein expression. We used protein expression and purification, miRNA overexpression, miRNA knockdown, transfection, site-directed mutagenesis, real-time PCR, luciferase assay and western blotting techniques to perform our study. Results HIV-1 Tat-C treatment of human microglial cells resulted in a dose-dependent increase in miR-32 expression. We found that tumor necrosis factor-receptor–associated factor 3 TRAF3 is a direct target for miR-32, and overexpression of miR-32 in CHME3 cells decreased TRAF3 both at the mRNA and the protein level. Recovery of TRAF3 protein expression after transfection of anti-miR-32 and the results of the luciferase reporter assay provided direct evidence of TRAF3 regulation by miR-32. We found that the regulation of interferon regulatory factor 3 (IRF3 and IRF7 is controlled by cellular levels of TRAF3 protein in microglial cells, as after overexpression of miR-32 and application of anti-miR-32, expression levels of IRF3 and IRF7 were inversely regulated by expression levels of TRAF3. Thus, our results suggest a novel miRNA mediated mechanism for regulation of TRAF3 in human microglial cells exposed to HIV-1 Tat C protein. These results may help to elucidate the detrimental neuroinflammatory consequences of HIV-1 Tat C protein in bystander fashion. Conclusion HIV-1 Tat protein can modulate TRAF3 expression through

  14. Antioxidative defense mechanisms controlled by Nrf2: state-of-the-art and clinical perspectives in neurodegenerative diseases

    NARCIS (Netherlands)

    Lim, J.L.; Wilhelmus, M.M.M.; de Vries, H.E.; Drukarch, B.; Hoozemans, J.J.M.; van Horssen, J.

    2014-01-01

    Activation of microglial cells and impaired mitochondrial function are common pathological characteristics of many neurological diseases and contribute to increased generation of reactive oxygen species (ROS). It is nowadays accepted that oxidative damage and mitochondrial dysfunction are key

  15. FimH adhesin of Escherichia coli K1 type 1 fimbriae activates BV-2 microglia

    International Nuclear Information System (INIS)

    Lee, Jongseok; Shin, Sooan; Teng, C.-H.; Hong, Suk Jin; Kim, Kwang Sik

    2005-01-01

    The generation of intense inflammation in the subarachnoid space in response to meningitis-causing bacteria contributes to brain dysfunction and neuronal injury in bacterial meningitis. Microglia, the major immune effector cells in the central nervous system (CNS), become activated by bacterial components to produce proinflammatory immune mediators. In this study, we showed that FimH adhesin, a tip component of type 1 fimbriae of meningitis-causing Escherichia coli K1, activated the murine microglial cell line, BV-2, which resulted in the production of nitric oxide and the release of tumor necrosis factor-α. Mitogen-activated protein kinases, ERK and p-38, and nuclear factor-κB were involved in FimH adhesin-mediated microglial activation. These findings suggest that FimH adhesin contributes to the CNS inflammatory response by virtue of activating microglia in E. coli meningitis

  16. PK11195 binding to the peripheral benzodiazepine receptor as a marker of microglia activation in multiple sclerosis and experimental autoimmune encephalomyelitis

    DEFF Research Database (Denmark)

    Vowinckel, E; Reutens, D; Becher, B

    1997-01-01

    Activated glial cells are implicated in regulating and effecting the immune response that occurs within the CNS as part of multiple sclerosis (MS) and its animal model experimental autoimmune encephalomyelitis (EAE). The peripheral benzodiazepine receptor (PBR) is expressed in glial cells. We...... examined the utility of using in vitro and in vivo ligand binding to the PBR as a measure of lesion activity in autoimmune CNS demyelinating diseases. Applying a combined autoradiography and immunohistochemical approach to spinal cord and brain tissues from mice with EAE, we found a correlation at sites...... of inflammatory lesions between [3H]-PK11195 binding and immunoreactivity for the activated microglial/macrophage marker Mac-1/CD11b. In MS tissues, [3H]-PK11195 binding correlated with sites of immunoreactivity for the microglial/macrophage marker CD68, at the edges of chronic active plaques. Positron emission...

  17. Cell Therapy for Parkinson's Disease: A Translational Approach to Assess the Role of Local and Systemic Immunosuppression.

    Science.gov (United States)

    Aron Badin, R; Vadori, M; Vanhove, B; Nerriere-Daguin, V; Naveilhan, P; Neveu, I; Jan, C; Lévèque, X; Venturi, E; Mermillod, P; Van Camp, N; Dollé, F; Guillermier, M; Denaro, L; Manara, R; Citton, V; Simioni, P; Zampieri, P; D'avella, D; Rubello, D; Fante, F; Boldrin, M; De Benedictis, G M; Cavicchioli, L; Sgarabotto, D; Plebani, M; Stefani, A L; Brachet, P; Blancho, G; Soulillou, J P; Hantraye, P; Cozzi, E

    2016-07-01

    Neural transplantation is a promising therapeutic approach for neurodegenerative diseases; however, many patients receiving intracerebral fetal allografts exhibit signs of immunization to donor antigens that could compromise the graft. In this context, we intracerebrally transplanted mesencephalic pig xenografts into primates to identify a suitable strategy to enable long-term cell survival, maturation, and differentiation. Parkinsonian primates received WT or CTLA4-Ig transgenic porcine xenografts and different durations of peripheral immunosuppression to test whether systemic plus graft-mediated local immunosuppression might avoid rejection. A striking recovery of spontaneous locomotion was observed in primates receiving systemic plus local immunosuppression for 6 mo. Recovery was associated with restoration of dopaminergic activity detected both by positron emission tomography imaging and histological examination. Local infiltration by T cells and CD80/86+ microglial cells expressing indoleamine 2,3-dioxigenase were observed only in CTLA4-Ig recipients. Results suggest that in this primate neurotransplantation model, peripheral immunosuppression is indispensable to achieve the long-term survival of porcine neuronal xenografts that is required to study the beneficial immunomodulatory effect of local blockade of T cell costimulation. © Copyright 2016 The American Society of Transplantation and the American Society of Transplant Surgeons.

  18. Polyphenols from the stems of Morus alba and their inhibitory activity against nitric oxide production by lipopolysaccharide-activated microglia.

    Science.gov (United States)

    Rivière, Céline; Krisa, Stéphanie; Péchamat, Laurent; Nassra, Merian; Delaunay, Jean-Claude; Marchal, Axel; Badoc, Alain; Waffo-Téguo, Pierre; Mérillon, Jean-Michel

    2014-09-01

    Neuroinflammatory processes are involved in the pathogenesis of many neurodegenerative disorders. Microglial cells, the main immune cells of the central nervous system, represent a target of interest to search for naturally occurring anti-inflammatory products. In this study, we evaluated the anti-inflammatory properties of polyphenols obtained from the stems of Morus alba. This edible species, known as white mulberry, is frequently studied because of its traditional use in Asian medicine and its richness in different types of polyphenols, some of which are known to be phytoalexins. One new coumarin glycoside, isoscopoletin 6-(6-O-β-apiofuranosyl-β-glucopyranoside) (1) was mainly isolated by CPC (centrifugal partition chromatography) from this plant, together with seven known polyphenols (2-8). Their structures were established on the basis of spectroscopic analyses including extensive 2D NMR studies. The eight isolated compounds were evaluated for their inhibitory activities on nitric oxide (NO) production in lipopolysaccharide (LPS)-induced BV-2 microglial cells. The absence of cell toxicity is checked by a MTT assay. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Benfotiamine upregulates antioxidative system in activated BV-2 microglia cells

    Directory of Open Access Journals (Sweden)

    Iva eBozic

    2015-09-01

    Full Text Available Chronic microglial activation and resulting sustained neuroinflammatory reaction are generally associated with neurodegeneration. Activated microglia acquires proinflammatory cellular profile that generates oxidative burst. Their persistent activation exacerbates inflammation, which damages healthy neurons via cytotoxic mediators, such as superoxide radical anion and nitric oxide. In our recent study, we have shown that benfotiamine (S-benzoylthiamine O-monophosphate possesses anti-inflammatory effects. Here, the effects of benfotiamine on the pro-oxidative component of activity of LPS-stimulated BV-2 cells were investigated. The activation of microglia was accompanied by upregulation of intracellular antioxidative defense, which was further promoted in the presence of benfotiamine. Namely, activated microglia exposed to non-cytotoxic doses of benfotiamine showed increased levels and activities of hydrogen peroxide- and superoxide-removing enzymes – catalase and glutathione system, and superoxide dismutase. In addition, benfotiamine showed the capacity to directly scavenge superoxide radical anion. As a consequence, benfotiamine suppressed the activation of microglia and provoked a decrease in NO and •O2- production and lipid peroxidation. In conclusion, benfotiamine might silence pro-oxidative activity of microglia to alleviate/prevent oxidative damage of neighboring CNS cells.

  20. Benfotiamine upregulates antioxidative system in activated BV-2 microglia cells.

    Science.gov (United States)

    Bozic, Iva; Savic, Danijela; Stevanovic, Ivana; Pekovic, Sanja; Nedeljkovic, Nadezda; Lavrnja, Irena

    2015-01-01

    Chronic microglial activation and resulting sustained neuroinflammatory reaction are generally associated with neurodegeneration. Activated microglia acquires proinflammatory cellular profile that generates oxidative burst. Their persistent activation exacerbates inflammation, which damages healthy neurons via cytotoxic mediators, such as superoxide radical anion and nitric oxide. In our recent study, we have shown that benfotiamine (S-benzoylthiamine O-monophosphate) possesses anti-inflammatory effects. Here, the effects of benfotiamine on the pro-oxidative component of activity of LPS-stimulated BV-2 cells were investigated. The activation of microglia was accompanied by upregulation of intracellular antioxidative defense, which was further promoted in the presence of benfotiamine. Namely, activated microglia exposed to non-cytotoxic doses of benfotiamine showed increased levels and activities of hydrogen peroxide- and superoxide-removing enzymes-catalase and glutathione system, and superoxide dismutase. In addition, benfotiamine showed the capacity to directly scavenge superoxide radical anion. As a consequence, benfotiamine suppressed the activation of microglia and provoked a decrease in NO and (·)O(-) 2 production and lipid peroxidation. In conclusion, benfotiamine might silence pro-oxidative activity of microglia to alleviate/prevent oxidative damage of neighboring CNS cells.

  1. Introducing directly induced microglia-like (iMG cells from fresh human monocytes: A novel translational research tool for psychiatric disorders.

    Directory of Open Access Journals (Sweden)

    Masahiro eOhgidani

    2015-05-01

    Full Text Available Microglia, glial cells with immunological functions, have been implicated in various neurological diseases and psychiatric disorders in rodent studies, and human postmortem and PET studies. However, the deeper molecular implications of living human microglia have not been clarified.Here, we introduce a novel translational research approach focusing on human microglia. We have recently developed a new technique for creating induced microglia-like (iMG cells from human peripheral blood. Two cytokines, GM-CSF and IL-34, converted human monocytes into the iMG cells within 14 days, which show various microglial characterizations; expressing markers, forming a ramified morphology, and phagocytic activity with various cytokine releases. We have already confirmed the applicability of this technique by analyzing iMG cells from a patient of Nasu-Hakola disease (Ohgidani et al., Sci Rep 2014. We herein show possible applications of the iMG cells in translational research.We believe that this iMG technique will open the door to explore various unknown dynamic aspects of human microglia in psychiatric disorders. This also opens new routes for psychopharmacological approach such as drug efficacy screening and personalized medicine.

  2. Achillea millefolium Aqueous Extract does not Impair Recognition ...

    African Journals Online (AJOL)

    inflammatory effects on lipopolysaccharide. (LPS)-activated primary cultures of brain microglial cells. Therefore, they concluded that A. millefolium could be beneficial in preventing/ treating neurodegenerative diseases like. Alzheimer and Parkinson [3]. In another study,. Molina- Hernandez et al reported anticonflict-like.

  3. Involvement of PPAR-γ in the neuroprotective and anti-inflammatory effects of angiotensin type 1 receptor inhibition: effects of the receptor antagonist telmisartan and receptor deletion in a mouse MPTP model of Parkinson's disease

    Directory of Open Access Journals (Sweden)

    Garrido-Gil Pablo

    2012-02-01

    Full Text Available Abstract Background Several recent studies have shown that angiotensin type 1 receptor (AT1 antagonists such as candesartan inhibit the microglial inflammatory response and dopaminergic cell loss in animal models of Parkinson's disease. However, the mechanisms involved in the neuroprotective and anti-inflammatory effects of AT1 blockers in the brain have not been clarified. A number of studies have reported that AT1 blockers activate peroxisome proliferator-activated receptor gamma (PPAR γ. PPAR-γ activation inhibits inflammation, and may be responsible for neuroprotective effects, independently of AT1 blocking actions. Methods We have investigated whether oral treatment with telmisartan (the most potent PPAR-γ activator among AT1 blockers provides neuroprotection against dopaminergic cell death and neuroinflammation, and the possible role of PPAR-γ activation in any such neuroprotection. We used a mouse model of parkinsonism induced by the dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP and co-administration of the PPAR-γ antagonist GW9662 to study the role of PPAR-γ activation. In addition, we used AT1a-null mice lesioned with MPTP to study whether deletion of AT1 in the absence of any pharmacological effect of AT1 blockers provides neuroprotection, and investigated whether PPAR-γ activation may also be involved in any such effect of AT1 deletion by co-administration of the PPAR-γ antagonist GW9662. Results We observed that telmisartan protects mouse dopaminergic neurons and inhibits the microglial response induced by administration of MPTP. The protective effects of telmisartan on dopaminergic cell death and microglial activation were inhibited by co-administration of GW9662. Dopaminergic cell death and microglial activation were significantly lower in AT1a-null mice treated with MPTP than in mice not subjected to AT1a deletion. Interestingly, the protective effects of AT1 deletion were also inhibited by co

  4. Lesion of the locus coeruleus aggravates dopaminergic neuron degeneration by modulating microglial function in mouse models of Parkinson׳s disease.

    Science.gov (United States)

    Yao, Ning; Wu, Yanhong; Zhou, Yan; Ju, Lili; Liu, Yujun; Ju, Rongkai; Duan, Deyi; Xu, Qunyuan

    2015-11-02

    The degeneration of noradrenergic neurons in the locus coeruleus (LC) commonly occurs in patients with Parkinson's disease (PD), which is characterized by a selective injury of dopaminergic neurons in the substantia nigra (SN). The pathological impact of the LC on the SN in the disease is unknown. In the present study, we used a noradrenergic toxin, N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP4), to deplete noradrenaline (NA) derived from the LC to explore its influence on degeneration or injury of dopaminergic neurons in the SN in mouse model produced by intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) or lipopolysaccharide (LPS). Our results demonstrated that lesion of the LC could change microglial function in the brain, which led to enhanced or prolonged expression of pro-inflammatory cytokines, diminished neurotrophic factors, and weakened ability of anti-oxidation in the SN. The in vitro experiments further confirmed that NA could reduce the inflammatory reaction of microglia. The selective injury of dopaminergic neurons by inflammation, however, was due to the inflammation in different brain regions rather than the depletion of NA. Our results indicate that the lesion in the LC is an important factor in promoting dopaminergic neuron degeneration by impacting the function of microglia in the midbrain. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Noisy Oscillations in the Actin Cytoskeleton of Chemotactic Amoeba

    Science.gov (United States)

    Negrete, Jose; Pumir, Alain; Hsu, Hsin-Fang; Westendorf, Christian; Tarantola, Marco; Beta, Carsten; Bodenschatz, Eberhard

    2016-09-01

    Biological systems with their complex biochemical networks are known to be intrinsically noisy. Here we investigate the dynamics of actin polymerization of amoeboid cells, which are close to the onset of oscillations. We show that the large phenotypic variability in the polymerization dynamics can be accurately captured by a generic nonlinear oscillator model in the presence of noise. We determine the relative role of the noise with a single dimensionless, experimentally accessible parameter, thus providing a quantitative description of the variability in a population of cells. Our approach, which rests on a generic description of a system close to a Hopf bifurcation and includes the effect of noise, can characterize the dynamics of a large class of noisy systems close to an oscillatory instability.

  6. An ultrastructural study of Paraphysoderma sedebokerense (Blastocladiomycota), an epibiotic parasite of microalgae.

    Science.gov (United States)

    Letcher, Peter M; Lee, Philip A; Lopez, Salvador; Burnett, Micheal; McBride, Robert C; Powell, Martha J

    2016-03-01

    Successful algal cultivation for biofuel production is one path in the transition to a renewable energy economy. The green alga Scenedesmus dimorphus is a candidate for biofuel production, but is subject to parasitism and subsequent population crash when cultivated in open ponds. From an open pond cultivating S. dimorphus for biofuel production in New Mexico, USA, an amoeboid parasite was isolated, designated as isolate FD61, and its rDNA operon sequenced. A BLAST search for nuc 18S rDNA (18S) sequence similarity identified the parasite as Paraphysoderma sedebokerense (Blastocladiomycota). Here, we examine the ultrastructure of P. sedebokerense and compare it with that of a sister taxon, Physoderma maydis. The parasite has thin-walled vegetative sporangia and thick-walled resting sporangia. Our observations indicate that amoeboid swarmers are produced in the vegetative phase, while either amoeboid swarmers or zoospores are the product of meiosis in resting sporangia. Meiosis is confirmed by the presence of synaptonemal complexes in resting sporangia nuclei. Notably, P. sedebokerense has a Golgi apparatus with stacked cisternae, a feature reported for P. maydis, but which is absent in all other examined taxa in Blastocladiomycota. This report furthers our knowledge of the life cycle of P. sedebokerense. Copyright © 2015 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  7. JNK and NADPH Oxidase Involved in Fluoride-Induced Oxidative Stress in BV-2 Microglia Cells

    Directory of Open Access Journals (Sweden)

    Ling Yan

    2013-01-01

    Full Text Available Excessive fluoride may cause central nervous system (CNS dysfunction, and oxidative stress is a recognized mode of action of fluoride toxicity. In CNS, activated microglial cells can release more reactive oxygen species (ROS, and NADPH oxidase (NOX is the major enzyme for the production of extracellular superoxide in microglia. ROS have been characterized as an important secondary messenger and modulator for various mammalian intracellular signaling pathways, including the MAPK pathways. In this study we examined ROS production and TNF-α, IL-1β inflammatory cytokines releasing, and the expression of MAPKs in BV-2 microglia cells treated with fluoride. We found that fluoride increased JNK phosphorylation level of BV-2 cells and pretreatment with JNK inhibitor SP600125 markedly reduced the levels of intracellular and NO. NOX inhibitor apocynin and iNOS inhibitor SMT dramatically decreased NaF-induced ROS and NO generations, respectively. Antioxidant melatonin (MEL resulted in a reduction in JNK phosphorylation in fluoride-stimulated BV-2 microglia. The results confirmed that NOX and iNOS played an important role in fluoride inducing oxidative stress and NO production and JNK took part in the oxidative stress induced by fluoride and meanwhile also could be activated by ROS in fluoride-treated BV-2 cells.

  8. JNK and NADPH Oxidase Involved in Fluoride-Induced Oxidative Stress in BV-2 Microglia Cells

    Science.gov (United States)

    Yan, Ling; Liu, Shengnan; Wang, Chen; Wang, Fei; Song, Yingli; Yan, Nan; Xi, Shuhua; Liu, Ziyou; Sun, Guifan

    2013-01-01

    Excessive fluoride may cause central nervous system (CNS) dysfunction, and oxidative stress is a recognized mode of action of fluoride toxicity. In CNS, activated microglial cells can release more reactive oxygen species (ROS), and NADPH oxidase (NOX) is the major enzyme for the production of extracellular superoxide in microglia. ROS have been characterized as an important secondary messenger and modulator for various mammalian intracellular signaling pathways, including the MAPK pathways. In this study we examined ROS production and TNF-α, IL-1β inflammatory cytokines releasing, and the expression of MAPKs in BV-2 microglia cells treated with fluoride. We found that fluoride increased JNK phosphorylation level of BV-2 cells and pretreatment with JNK inhibitor SP600125 markedly reduced the levels of intracellular O2 ·− and NO. NOX inhibitor apocynin and iNOS inhibitor SMT dramatically decreased NaF-induced ROS and NO generations, respectively. Antioxidant melatonin (MEL) resulted in a reduction in JNK phosphorylation in fluoride-stimulated BV-2 microglia. The results confirmed that NOX and iNOS played an important role in fluoride inducing oxidative stress and NO production and JNK took part in the oxidative stress induced by fluoride and meanwhile also could be activated by ROS in fluoride-treated BV-2 cells. PMID:24072958

  9. The neuroprotective effects of milk fat globule-EGF factor 8 against oligomeric amyloid β toxicity

    Directory of Open Access Journals (Sweden)

    Li Endong

    2012-06-01

    Full Text Available Abstract Background Phosphatidylserine receptor is a key molecule that mediates the phagocytosis of apoptotic cells. Milk fat globule-EGF factor 8 (MFG-E8 is a phosphatidylserine receptor that is expressed on various macrophage lineage cells, including microglia in the central nervous system (CNS. Targeted clearance of degenerated neurons by microglia is essential to maintain healthy neural networks. We previously showed that the CX3C chemokine fractalkine is secreted from degenerated neurons and accelerates microglial clearance of neuronal debris via inducing the release of MFG-E8. However, the mechanisms by which microglia produce MFG-E8 and the precise functions of MFG-E8 are unknown. Methods The release of MFG-E8 from microglia treated with conditioned medium from neurons exposed to neurotoxic substances, glutamate or oligomeric amyloid β (oAβ was measured by ELISA. The neuroprotective effects of MFG-E8 and MFG-E8 − induced microglial phagocytosis of oAβ were assessed by immunocytochemistry. The effects of MFG-E8 on the production of the anti-oxidative enzyme hemeoxygenase-1 (HO-1 were determined by ELISA and immunocytochemisty. Results MFG-E8 was induced in microglia treated with conditioned medium from neurons that had been exposed to neurotoxicants, glutamate or oAβ. MFG-E8 significantly attenuated oAβ-induced neuronal cell death in a primary neuron − microglia coculture system. Microglial phagocytosis of oAβ was accelerated by MFG-E8 treatment due to increased CD47 expression in the absence of neurotoxic molecule production, such as tumor necrosis factor-α, nitric oxide, and glutamate. MFG-E8 − treated microglia induced nuclear factor E(2 − related factor 2 (Nrf2 − mediated HO-1 production, which also contributed to neuroprotection. Conclusions These results suggest that microglia release MFG-E8 in response to signals from degenerated neurons and that MFG-E8 protects oAβ-induced neuronal cell death

  10. Prominent microglial activation in cortical white matter is selectively associated with cortical atrophy in primary progressive aphasia.

    Science.gov (United States)

    Ohm, Daniel T; Kim, Garam; Gefen, Tamar; Rademaker, Alfred; Weintraub, Sandra; Bigio, Eileen; Mesulam, M-Marsel; Rogalski, Emily; Geula, Changiz

    2018-04-21

    Primary progressive aphasia (PPA) is a clinical syndrome characterized by selective language impairments associated with focal cortical atrophy favouring the language dominant hemisphere. PPA is associated with Alzheimer's disease (AD), frontotemporal lobar degeneration (FTLD), and significant accumulation of activated microglia. Activated microglia can initiate an inflammatory cascade that may contribute to neurodegeneration, but their quantitative distribution in cortical white matter and their relationship with cortical atrophy are unknown. We investigated white matter activated microglia and their association with grey matter atrophy in 10 PPA cases with either AD or FTLD-TDP pathology. Activated microglia were quantified with optical density measures of HLA-DR immunoreactivity in two regions with peak cortical atrophy, and one non-atrophied region within the language dominant hemisphere of each PPA case. Non-atrophied contralateral homologues of the language dominant regions were examined for hemispheric asymmetry. Qualitatively, greater densities of activated microglia were observed in cortical white matter when compared to grey matter. Quantitative analyses revealed significantly greater densities of activated microglia in the white matter of atrophied regions compared to non-atrophied regions in the language dominant hemisphere (p<0.05). Atrophied regions of the language dominant hemisphere also showed significantly more activated microglia compared to contralateral homologues (p<0.05). White matter activated microglia accumulate more in atrophied regions in the language dominant hemisphere of PPA. While microglial activation may constitute a response to neurodegenerative processes in white matter, the resultant inflammatory processes may also exacerbate disease progression and contribute to cortical atrophy. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  11. Microglia Gone Rogue: Impacts on Psychiatric Disorders across the Lifespan.

    Science.gov (United States)

    Tay, Tuan Leng; Béchade, Catherine; D'Andrea, Ivana; St-Pierre, Marie-Kim; Henry, Mathilde S; Roumier, Anne; Tremblay, Marie-Eve

    2017-01-01

    Microglia are the predominant immune response cells and professional phagocytes of the central nervous system (CNS) that have been shown to be important for brain development and homeostasis. These cells present a broad spectrum of phenotypes across stages of the lifespan and especially in CNS diseases. Their prevalence in all neurological pathologies makes it pertinent to reexamine their distinct roles during steady-state and disease conditions. A major question in the field is determining whether the clustering and phenotypical transformation of microglial cells are leading causes of pathogenesis, or potentially neuroprotective responses to the onset of disease. The recent explosive growth in our understanding of the origin and homeostasis of microglia, uncovering their roles in shaping of the neural circuitry and synaptic plasticity, allows us to discuss their emerging functions in the contexts of cognitive control and psychiatric disorders. The distinct mesodermal origin and genetic signature of microglia in contrast to other neuroglial cells also make them an interesting target for the development of therapeutics. Here, we review the physiological roles of microglia, their contribution to the effects of environmental risk factors (e.g., maternal infection, early-life stress, dietary imbalance), and their impact on psychiatric disorders initiated during development (e.g., Nasu-Hakola disease (NHD), hereditary diffuse leukoencephaly with spheroids, Rett syndrome, autism spectrum disorders (ASDs), and obsessive-compulsive disorder (OCD)) or adulthood (e.g., alcohol and drug abuse, major depressive disorder (MDD), bipolar disorder (BD), schizophrenia, eating disorders and sleep disorders). Furthermore, we discuss the changes in microglial functions in the context of cognitive aging, and review their implication in neurodegenerative diseases of the aged adult (e.g., Alzheimer's and Parkinson's). Taking into account the recent identification of microglia

  12. Microglia Gone Rogue: Impacts on Psychiatric Disorders across the Lifespan

    Directory of Open Access Journals (Sweden)

    Tuan Leng Tay

    2018-01-01

    Full Text Available Microglia are the predominant immune response cells and professional phagocytes of the central nervous system (CNS that have been shown to be important for brain development and homeostasis. These cells present a broad spectrum of phenotypes across stages of the lifespan and especially in CNS diseases. Their prevalence in all neurological pathologies makes it pertinent to reexamine their distinct roles during steady-state and disease conditions. A major question in the field is determining whether the clustering and phenotypical transformation of microglial cells are leading causes of pathogenesis, or potentially neuroprotective responses to the onset of disease. The recent explosive growth in our understanding of the origin and homeostasis of microglia, uncovering their roles in shaping of the neural circuitry and synaptic plasticity, allows us to discuss their emerging functions in the contexts of cognitive control and psychiatric disorders. The distinct mesodermal origin and genetic signature of microglia in contrast to other neuroglial cells also make them an interesting target for the development of therapeutics. Here, we review the physiological roles of microglia, their contribution to the effects of environmental risk factors (e.g., maternal infection, early-life stress, dietary imbalance, and their impact on psychiatric disorders initiated during development (e.g., Nasu-Hakola disease (NHD, hereditary diffuse leukoencephaly with spheroids, Rett syndrome, autism spectrum disorders (ASDs, and obsessive-compulsive disorder (OCD or adulthood (e.g., alcohol and drug abuse, major depressive disorder (MDD, bipolar disorder (BD, schizophrenia, eating disorders and sleep disorders. Furthermore, we discuss the changes in microglial functions in the context of cognitive aging, and review their implication in neurodegenerative diseases of the aged adult (e.g., Alzheimer’s and Parkinson’s. Taking into account the recent identification of

  13. Does minocycline, an antibiotic with inhibitory effects on microglial activation, sharpen a sense of trust in social interaction?

    Science.gov (United States)

    Watabe, Motoki; Kato, Takahiro A; Monji, Akira; Horikawa, Hideki; Kanba, Shigenobu

    2012-04-01

    Minocycline has long been applied to various infectious diseases as a tetracycline antibiotic and recently has found new application in the treatment of brain diseases such as stroke and multiple sclerosis. In addition, minocycline has also been suggested as an effective drug for psychiatric diseases. These suggestions imply that minocycline may modulate our mental activities, while the underlying mechanism remains to be clarified. To investigate how minocycline influences human mental activity, we experimentally examined how minocycline works on human social decision making in a double-blind randomized trial. Forty-nine healthy volunteers were administered minocycline or placebo over four days, after which they played (1) a trust game, in which they decided how much to trust an anonymous partner, and (2) a dictator game, in which they decided how to divide resources between themselves and an anonymous partner. The minocycline group did not display increased trusting behavior or more altruistic resource allocation. In fact, the minocycline group displayed a slight reduction in trusting behavior. However, the minocycline group did show a strong positive correlation between the degree of risk taking in the trust game and in a separate evaluation of others' trustworthiness, whereas the placebo group showed no such correlation. These results suggest that minocycline led to more rational decision-making strategies, possibly by increasing emotion regulation. Since minocycline is a well-known inhibitor of microglial activation, our findings may open a new optional pathway for treating mental states in which a component of rational decision making is impaired.

  14. Microglia - insights into immune system structure, function, and reactivity in the central nervous system

    DEFF Research Database (Denmark)

    Wirenfeldt, Martin; Babcock, Alicia A; Vinters, Harry V

    2011-01-01

    Microglia are essential cellular components of a well-functioning central nervous system (CNS). The development and establishment of the microglial population differs from the other major cell populations in the CNS i.e. neurons and macroglia (astrocytes and oligodendrocytes). This different onto...

  15. Mesenchymal stem cell transplantation attenuates blood brain barrier damage and neuroinflammation and protects dopaminergic neurons against MPTP toxicity in the substantia nigra in a model of Parkinson's disease.

    Science.gov (United States)

    Chao, Yin Xia; He, Bei Ping; Tay, Samuel Sam Wah

    2009-11-30

    Immunomodulatory effects of transplanted mesenchymal stem cells (MSCs) in the treatment of Parkinson's disease were studied in the MPTP-induced mouse model. MPTP treatment induced a significant loss of dopaminergic neurons, decreased expressions of claudin 1, claudin 5 and occludin in the substantia nigra compacta (SNc), and functional damage of the blood brain barrier (BBB). Our study further discovered that infiltration of MBLs into the brain to bind with microglia was detected in the SNc of MPTP-treated mice, suggesting that the BBB compromise and MBL infiltration might be involved in the pathogenesis of MPTP-induced PD. In addition, MPTP treatment also increased the expression of mannose-binding lectins (MBLs) in the liver tissue. Intravenous transplantation of MSCs into MPTP-treated mice led to recovery of BBB integrity, suppression of MBL infiltration at SNc and MBL expression in the liver, suppression of microglial activation and prevention of dopaminergic neuron death. No transplanted MSCs were observed to differentiate into dopaminergic neurons, while the MSCs migrated into the SNc and released TGF-beta1 there. Therefore, intravenous transplantation of MSCs which protect dopaminergic neurons from MPTP toxicity may be engaged in anyone or a combination of these mechanisms: repair of the BBB, reduction of MBL in the brain, inhibition of microglial cytotoxicity, and direct protection of dopaminergic neurons.

  16. Benfotiamine upregulates antioxidative system in activated BV-2 microglia cells

    OpenAIRE

    Bozic, Iva; Savic, Danijela; Stevanovic, Ivana; Pekovic, Sanja; Nedeljkovic, Nadezda; Lavrnja, Irena

    2015-01-01

    Chronic microglial activation and resulting sustained neuroinflammatory reaction are generally associated with neurodegeneration. Activated microglia acquires proinflammatory cellular profile that generates oxidative burst. Their persistent activation exacerbates inflammation, which damages healthy neurons via cytotoxic mediators, such as superoxide radical anion and nitric oxide. In our recent study, we have shown that benfotiamine (S-benzoylthiamine O-monophosphate) possesses anti-inflammat...

  17. Reactive microglia after taste nerve injury: comparison to nerve injury models of chronic pain [v1; ref status: indexed, http://f1000r.es/wh

    Directory of Open Access Journals (Sweden)

    Dianna L Bartel

    2013-02-01

    Full Text Available The chorda tympani (CT, which innervates taste buds on the anterior portion of the tongue, is susceptible to damage during inner ear surgeries. Injury to the CT causes a disappearance of taste buds, which is concurrent with significant microglial responses at central nerve terminals in the nucleus of the solitary tract (nTS. The resulting taste disturbances that can occur may persist for months or years, long after the nerve and taste buds have regenerated. These persistent changes in taste sensation suggest alterations in central functioning and may be related to the microglial responses. This is reminiscent of nerve injuries that result in chronic pain, where microglial reactivity is essential in maintaining the altered sensation (i.e., pain. In these models, methods that diminish microglial responses also diminish the corresponding pain behavior. Although the CT nerve does not contain nociceptive pain fibers, the microglial reactivity after CT damage is similar to that described in pain models. Therefore, methods that decrease microglial responses in pain models were used here to test if they could also affect microglial reactivity after CT injury. Treatment with minocycline, an antibiotic that dampens pain responsive microglia, was largely ineffective in diminishing microglial responses after CT injury. In addition, signaling through the toll-like 4 receptor (TLR4 does not seem to be required after CT injury as blocking or deleting TLR4 had no effect on microglial reactivity. These results suggest that microglial responses following CT injury rely on different signaling mechanisms than those described in nerve injuries resulting in chronic pain.

  18. Opposite patterns of age-associated changes in neurons and glial cells of the thalamus of human brain.

    Science.gov (United States)

    Guidolin, D; Zunarelli, E; Genedani, S; Trentini, G P; De Gaetani, C; Fuxe, K; Benegiamo, C; Agnati, L F

    2008-06-01

    In an autopsy series of 19 individuals, age-ranged 24-94, a relatively age-spared region, the anterior-ventral thalamus, was analyzed by immunohistochemical techniques to visualize neurons (neurofilament protein), astrocytes (glial fibrillary acidic protein), microglial cells (CD68) and amyloid precursor protein. The pattern of immunoreactivity was determined by surface fractal dimension and lacunarity, the size by the field area (FA) and the spatial uniformity by the uniformity index. From the normalized FA values of immunoreactivity for the four markers studied, a global parameter was defined to give an overall characterization of the age-dependent changes in the glio-neuronal networks. A significant exponential decline of the GP was observed with increasing age. This finding suggests that early in life (ageage>70 years) could be due to the non-trophic reserve still available.

  19. CD36 participates in PrP(106-126-induced activation of microglia.

    Directory of Open Access Journals (Sweden)

    Mohammed Kouadir

    Full Text Available Microglial activation is a characteristic feature of the pathogenesis of prion diseases. The molecular mechanisms that underlie prion-induced microglial activation are not very well understood. In the present study, we investigated the role of the class B scavenger receptor CD36 in microglial activation induced by neurotoxic prion protein (PrP fragment 106-126 (PrP(106-126. We first examined the time course of CD36 mRNA expression upon exposure to PrP(106-126 in BV2 microglia. We then analyzed different parameters of microglial activation in PrP(106-126-treated cells in the presence or not of anti-CD36 monoclonal antibody (mAb. The cells were first incubated for 1 h with CD36 monoclonal antibody to block the CD36 receptor, and were then treated with neurotoxic prion peptides PrP(106-126. The results showed that PrP(106-126 treatment led to a rapid yet transitory increase in the mRNA expression of CD36, upregulated mRNA and protein levels of proinflammatory cytokines (IL-1β, IL-6 and TNF-α, increased iNOS expression and nitric oxide (NO production, stimulated the activation of NF-κB and caspase-1, and elevated Fyn activity. The blockade of CD36 had no effect on PrP(106-126-stimulated NF-κB activation and TNF-α protein release, abrogated the PrP(106-126-induced iNOS stimulation, downregulated IL-1β and IL-6 expression at both mRNA and protein levels as well as TNF-α mRNA expression, decreased NO production and Fyn phosphorylation, reduced caspase-1 cleavage induced by moderate PrP(106-126-treatment, but had no effect on caspase-1 activation after treatment with a high concentration of PrP(106-126. Together, these results suggest that CD36 is involved in PrP(106-126-induced microglial activation and that the participation of CD36 in the interaction between PrP(106-126 and microglia may be mediated by Src tyrosine kinases. Our findings provide new insights into the mechanisms underlying the activation of microglia by neurotoxic prion peptides

  20. Blockade of NMDA receptors decreased spinal microglia activation in bee venom induced acute inflammatory pain in rats.

    Science.gov (United States)

    Li, Li; Wu, Yongfang; Bai, Zhifeng; Hu, Yuyan; Li, Wenbin

    2017-03-01

    Microglial cells in spinal dorsal horn can be activated by nociceptive stimuli and the activated microglial cells release various cytokines enhancing the nociceptive transmission. However, the mechanisms underlying the activation of spinal microglia during nociceptive stimuli have not been well understood. In order to define the role of NMDA receptors in the activation of spinal microglia during nociceptive stimuli, the present study was undertaken to investigate the effect of blockade of NMDA receptors on the spinal microglial activation induced by acute peripheral inflammatory pain in rats. The acute inflammatory pain was induced by subcutaneous bee venom injection to the plantar surface of hind paw of rats. Spontaneous pain behavior, thermal withdrawal latency and mechanical withdrawal threshold were rated. The expression of specific microglia marker CD11b/c was assayed by immunohistochemistry and western blot. After bee venom treatment, it was found that rats produced a monophasic nociception characterized by constantly lifting and licking the injected hind paws, decreased thermal withdrawal latency and mechanical withdrawal threshold; immunohistochemistry displayed microglia with enlarged cell bodies, thickened, extended cellular processes with few ramifications, small spines, and intensive immunostaining; western blot showed upregulated expression level of CD11b/c within the period of hyperalgesia. Prior intrathecal injection of MK-801, a selective antagonist of NMDA receptors, attenuated the pain behaviors and suppressed up-regulation of CD11b/c induced by bee venom. It can be concluded that NMDA receptors take part in the mediation of spinal microglia activation in bee venom induced peripheral inflammatory pain and hyperalgesia in rats.

  1. Neurotoxic effect of 2,5-hexanedione on neural progenitor cells and hippocampal neurogenesis

    International Nuclear Information System (INIS)

    Kim, Min-Sun; Park, Hee Ra; Park, Mikyung; Kim, So Jung; Kwon, Mugil; Yu, Byung Pal; Chung, Hae Young; Kim, Hyung Sik; Kwack, Seung Jun; Kang, Tae Seok; Kim, Seung Hee; Lee, Jaewon

    2009-01-01

    2,5-Hexanedione (HD), a metabolite of n-hexane, causes central and peripheral neuropathy leading to motor neuron deficits. Although chronic exposure to n-hexane is known to cause gradual sensorimotor neuropathy, there are no reports on the effects of low doses of HD on neurogenesis in the central nervous system. In the current study, we explored HD toxicity in murine neural progenitor cells (NPC), primary neuronal culture and young adult mice. HD (500 nM∼50 μM) dose-dependently suppressed NPC proliferation and cell viability, and also increased the production of reactive oxygen species (ROS). HD (10 or 50 mg/kg for 2 weeks) inhibited hippocampal neuronal and NPC proliferation in 6-week-old male ICR mice, as measured by BrdU incorporation in the dentate gyrus, indicating HD impaired hippocampal neurogenesis. In addition, elevated microglial activation was observed in the hippocampal CA3 region and lateral ventricles of HD-treated mice. Lastly, HD dose-dependently decreased the viability of primary cultured neurons. Based on biochemical and histochemical evidence from both cell culture and HD-treated animals, the neurotoxic mechanisms by which HD inhibits NPC proliferation and hippocampal neurogenesis may relate to its ability to elicit an increased generation of deleterious ROS.

  2. Neuroprotective Effect of Sargassum thunbergii (Mertens ex Roth ...

    African Journals Online (AJOL)

    Purpose: To evaluate the anti-oxidant and anti-neuroinflammatory effects of the Sargassum thunbergii extract (Mertens ex Roth) Kuntze (STE) in lipopolysaccharide (LPS)-stimulated BV-2 microglial cells in vitro. Methods: STE antioxidative activity was evaluated with an Electron Spin Resonance (ESR) spectrometer, which ...

  3. Methanol Extract of Hydroclathrus clathratus Inhibits Production of ...

    African Journals Online (AJOL)

    Methanol Extract of Hydroclathrus clathratus Inhibits Production of Nitric Oxide, Prostaglandin E2 and Tumor Necrosis Factor-α in Lipopolysaccharidestimulated BV2 Microglial Cells via Inhibition of NF-κB Activity. RGPT Jayasooriya, D-O Moon, YH Chol, C-H Yoon, G-Y Kim ...

  4. Inflammation and neuronal death in the motor cortex of the wobbler mouse, an ALS animal model

    DEFF Research Database (Denmark)

    Dahlke, Carolin; Saberi, Darius; Ott, Bastian

    2015-01-01

    microscopy, and transmission electron microscopy techniques, we analyze the proliferation behavior of microglial cells and astrocytes. We also investigate possible motor neuron death in the mouse motor cortex at different stages of the wobbler disease, which so far has not received much attention. Results...

  5. Early correlation of microglial activation with enhanced tumor necrosis factor-alpha and monocyte chemoattractant protein-1 expression specifically within the entorhinal cortex of triple transgenic Alzheimer's disease mice

    Directory of Open Access Journals (Sweden)

    LaFerla Frank M

    2005-10-01

    Full Text Available Abstract Background Alzheimer's disease is a complex neurodegenerative disorder characterized pathologically by a temporal and spatial progression of beta-amyloid (Aβ deposition, neurofibrillary tangle formation, and synaptic degeneration. Inflammatory processes have been implicated in initiating and/or propagating AD-associated pathology within the brain, as inflammatory cytokine expression and other markers of inflammation are pronounced in individuals with AD pathology. The current study examines whether inflammatory processes are evident early in the disease process in the 3xTg-AD mouse model and if regional differences in inflammatory profiles exist. Methods Coronal brain sections were used to identify Aβ in 2, 3, and 6-month 3xTg-AD and non-transgenic control mice. Quantitative real-time RT-PCR was performed on microdissected entorhinal cortex and hippocampus tissue of 2, 3, and 6-month 3xTg-AD and non-transgenic mice. Microglial/macrophage cell numbers were quantified using unbiased stereology in 3xTg-AD and non-transgenic entorhinal cortex and hippocampus containing sections. Results We observed human Aβ deposition at 3 months in 3xTg-AD mice which is enhanced by 6 months of age. Interestingly, we observed a 14.8-fold up-regulation of TNF-α and 10.8-fold up-regulation of MCP-1 in the entorhinal cortex of 3xTg-AD mice but no change was detected over time in the hippocampus or in either region of non-transgenic mice. Additionally, this increase correlated with a specific increase in F4/80-positive microglia and macrophages in 3xTg-AD entorhinal cortex. Conclusion Our data provide evidence for early induction of inflammatory processes in a model that develops amyloid and neurofibrillary tangle pathology. Additionally, our results link inflammatory processes within the entorhinal cortex, which represents one of the earliest AD-affected brain regions.

  6. Acute Neuroinflammatory Response in the Substantia Nigra Pars Compacta of Rats after a Local Injection of Lipopolysaccharide

    Science.gov (United States)

    Gonzalez-Barrios, Juan A.; Gutierrez-Castillo, Maria E.

    2018-01-01

    Models of Parkinson's disease with neurotoxins have shown that microglial activation does not evoke a typical inflammatory response in the substantia nigra, questioning whether neuroinflammation leads to neurodegeneration. To address this issue, the archetypal inflammatory stimulus, lipopolysaccharide (LPS), was injected into the rat substantia nigra. LPS induced fever, sickness behavior, and microglial activation (OX42 immunoreactivity), followed by astrocyte activation and leukocyte infiltration (GFAP and CD45 immunoreactivities). During the acute phase of neuroinflammation, pro- and anti-inflammatory cytokines (TNF-α, IL-1β, IL-6, IL-4, and IL-10) responded differentially at mRNA and protein level. Increased NO production and lipid peroxidation occurred at 168 h after LPS injection. At this time, evidence of neurodegeneration could be seen, entailing decreased tyrosine hydroxylase (TH) immunoreactivity, irregular body contour, and prolongation discontinuity of TH+ cells, as well as apparent phagocytosis of TH+ cells by OX42+ cells. Altogether, these results show that LPS evokes a typical inflammatory response in the substantia nigra that is followed by dopaminergic neurodegeneration. PMID:29854828

  7. Acute Neuroinflammatory Response in the Substantia Nigra Pars Compacta of Rats after a Local Injection of Lipopolysaccharide

    Directory of Open Access Journals (Sweden)

    Yazmin M. Flores-Martinez

    2018-01-01

    Full Text Available Models of Parkinson’s disease with neurotoxins have shown that microglial activation does not evoke a typical inflammatory response in the substantia nigra, questioning whether neuroinflammation leads to neurodegeneration. To address this issue, the archetypal inflammatory stimulus, lipopolysaccharide (LPS, was injected into the rat substantia nigra. LPS induced fever, sickness behavior, and microglial activation (OX42 immunoreactivity, followed by astrocyte activation and leukocyte infiltration (GFAP and CD45 immunoreactivities. During the acute phase of neuroinflammation, pro- and anti-inflammatory cytokines (TNF-α, IL-1β, IL-6, IL-4, and IL-10 responded differentially at mRNA and protein level. Increased NO production and lipid peroxidation occurred at 168 h after LPS injection. At this time, evidence of neurodegeneration could be seen, entailing decreased tyrosine hydroxylase (TH immunoreactivity, irregular body contour, and prolongation discontinuity of TH+ cells, as well as apparent phagocytosis of TH+ cells by OX42+ cells. Altogether, these results show that LPS evokes a typical inflammatory response in the substantia nigra that is followed by dopaminergic neurodegeneration.

  8. Upregulation of glycolytic enzymes, mitochondrial dysfunction and increased cytotoxicity in glial cells treated with Alzheimer's disease plasma.

    Directory of Open Access Journals (Sweden)

    Tharusha Jayasena

    Full Text Available Alzheimer's disease (AD is a neurodegenerative disorder associated with increased oxidative stress and neuroinflammation. Markers of increased protein, lipid and nucleic acid oxidation and reduced activities of antioxidant enzymes have been reported in AD plasma. Amyloid plaques in the AD brain elicit a range of reactive inflammatory responses including complement activation and acute phase reactions, which may also be reflected in plasma. Previous studies have shown that human AD plasma may be cytotoxic to cultured cells. We investigated the effect of pooled plasma (n = 20 each from healthy controls, individuals with amnestic mild cognitive impairment (aMCI and Alzheimer's disease (AD on cultured microglial cells. AD plasma and was found to significantly decrease cell viability and increase glycolytic flux in microglia compared to plasma from healthy controls. This effect was prevented by the heat inactivation of complement. Proteomic methods and isobaric tags (iTRAQ found the expression level of complement and other acute phase proteins to be altered in MCI and AD plasma and an upregulation of key enzymes involved in the glycolysis pathway in cells exposed to AD plasma. Altered expression levels of acute phase reactants in AD plasma may alter the energy metabolism of glia.

  9. Neuronal and microglial regulators of cortical wiring: usual and novel guideposts

    Directory of Open Access Journals (Sweden)

    Paola eSquarzoni

    2015-07-01

    Full Text Available Neocortex functioning relies on the formation of complex networks that begins to be assembled during embryogenesis by highly stereotyped processes of cell migration and axonal navigation. The guidance of cells and axons is driven by extracellular cues, released along by final targets or intermediate targets located along specific pathways. In particular, guidepost cells, originally described in the grasshopper, are considered discrete, specialized cell populations located at crucial decision points along axonal trajectories that regulate tract formation. These cells are usually early-born, transient and act at short-range or via cell-cell contact. The vast majority of guidepost cells initially identified were glial cells, which play a role in the formation of important axonal tracts in the forebrain, such as the corpus callosum, anterior and post-optic commissures as well as optic chiasm. In the last decades, tangential migrating neurons have also been found to participate in the guidance of principal axonal tracts in the forebrain. This is the case for several examples such as guideposts for the lateral olfactory tract (LOT, corridor cells, which open an internal path for thalamo-cortical axons and Cajal-Retzius cells that have been involved in the formation of the entorhino-hippocampal connections. More recently, microglia, the resident macrophages of the brain, were specifically observed at the crossroads of important neuronal migratory routes and axonal tract pathways during forebrain development. We furthermore found that microglia participate to the shaping of prenatal forebrain circuits, thereby opening novel perspectives on forebrain development and wiring. Here we will review the last findings on already known guidepost cells populations and will discuss the role of microglia as a potentially new class of atypical guidepost cells.

  10. The flavonoid fisetin attenuates postischemic immune cell infiltration, activation and infarct size after transient cerebral middle artery occlusion in mice

    Science.gov (United States)

    Gelderblom, Mathias; Leypoldt, Frank; Lewerenz, Jan; Birkenmayer, Gabriel; Orozco, Denise; Ludewig, Peter; Thundyil, John; Arumugam, Thiruma V; Gerloff, Christian; Tolosa, Eva; Maher, Pamela; Magnus, Tim

    2012-01-01

    The development of the brain tissue damage in ischemic stroke is composed of an immediate component followed by an inflammatory response with secondary tissue damage after reperfusion. Fisetin, a flavonoid, has multiple biological effects, including neuroprotective and antiinflammatory properties. We analyzed the effects of fisetin on infarct size and the inflammatory response in a mouse model of stroke, temporary middle cerebral artery occlusion, and on the activation of immune cells, murine primary and N9 microglial and Raw264.7 macrophage cells and human macrophages, in an in vitro model of inflammatory immune cell activation by lipopolysaccharide (LPS). Fisetin not only protected brain tissue against ischemic reperfusion injury when given before ischemia but also when applied 3 hours after ischemia. Fisetin also prominently inhibited the infiltration of macrophages and dendritic cells into the ischemic hemisphere and suppressed the intracerebral immune cell activation as measured by intracellular tumor necrosis factor α (TNFα) production. Fisetin also inhibited LPS-induced TNFα production and neurotoxicity of macrophages and microglia in vitro by suppressing nuclear factor κB activation and JNK/Jun phosphorylation. Our findings strongly suggest that the fisetin-mediated inhibition of the inflammatory response after stroke is part of the mechanism through which fisetin is neuroprotective in cerebral ischemia. PMID:22234339

  11. Brucella abortus-activated microglia induce neuronal death through primary phagocytosis.

    Science.gov (United States)

    Rodríguez, Ana M; Delpino, M Victoria; Miraglia, M Cruz; Costa Franco, Miriam M; Barrionuevo, Paula; Dennis, Vida A; Oliveira, Sergio C; Giambartolomei, Guillermo H

    2017-07-01

    Inflammation has long been implicated as a contributor to pathogenesis in neurobrucellosis. Many of the associated neurocognitive symptoms of neurobrucellosis may be the result of neuronal dysfunction resulting from the inflammatory response induced by Brucella abortus infection in the central nervous system. In this manuscript, we describe an immune mechanism for inflammatory activation of microglia that leads to neuronal death upon B. abortus infection. B. abortus was unable to infect or harm primary cultures of mouse neurons. However, when neurons were co-cultured with microglia and infected with B. abortus significant neuronal loss occurred. This phenomenon was dependent on TLR2 activation by Brucella lipoproteins. Neuronal death was not due to apoptosis, but it was dependent on the microglial release of nitric oxide (NO). B. abortus infection stimulated microglial proliferation, phagocytic activity and engulfment of neurons. NO secreted by B. abortus-activated microglia induced neuronal exposure of the "eat-me" signal phosphatidylserine (PS). Blocking of PS-binding to protein milk fat globule epidermal growth factor-8 (MFG-E8) or microglial vitronectin receptor-MFG-E8 interaction was sufficient to prevent neuronal loss by inhibiting microglial phagocytosis without affecting their activation. Taken together, our results indicate that B. abortus is not directly toxic to neurons; rather, these cells become distressed and are killed by phagocytosis in the inflammatory surroundings generated by infected microglia. Neuronal loss induced by B. abortus-activated microglia may explain, in part, the neurological deficits observed during neurobrucellosis. © 2017 Wiley Periodicals, Inc.

  12. Early Postnatal Lipopolysaccharide Exposure Leads to Enhanced Neurogenesis and Impaired Communicative Functions in Rats.

    Directory of Open Access Journals (Sweden)

    Yi Pang

    Full Text Available Perinatal infection is a well-identified risk factor for a number of neurodevelopmental disorders, including brain white matter injury (WMI and Autism Spectrum Disorders (ASD. The underlying mechanisms by which early life inflammatory events cause aberrant neural, cytoarchitectural, and network organization, remain elusive. This study is aimed to investigate how systemic lipopolysaccharide (LPS-induced neuroinflammation affects microglia phenotypes and early neural developmental events in rats. We show here that LPS exposure at early postnatal day 3 leads to a robust microglia activation which is characterized with mixed microglial proinflammatory (M1 and anti-inflammatory (M2 phenotypes. More specifically, we found that microglial M1 markers iNOS and MHC-II were induced at relatively low levels in a regionally restricted manner, whereas M2 markers CD206 and TGFβ were strongly upregulated in a sub-set of activated microglia in multiple white and gray matter structures. This unique microglial response was associated with a marked decrease in naturally occurring apoptosis, but an increase in cell proliferation in the subventricular zone (SVZ and the dentate gyrus (DG of hippocampus. LPS exposure also leads to a significant increase in oligodendrocyte lineage population without causing discernible hypermyelination. Moreover, LPS-exposed rats exhibited significant impairments in communicative and cognitive functions. These findings suggest a possible role of M2-like microglial activation in abnormal neural development that may underlie ASD-like behavioral impairments.

  13. Tropical Journal of Pharmaceutical Research - Vol 12, No 1 (2013)

    African Journals Online (AJOL)

    Inhibition of Nitric Oxide and Prostaglandin E2 Expression by Methanol Extract of Polyopes affinis in Lipopolysaccharide-stimulated BV2 Microglial Cells through Suppression of Akt-dependent NF-kB Activity and MAPK Pathway · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD ...

  14. Ocular Changes in TgF344-AD Rat Model of Alzheimer's Disease

    OpenAIRE

    Tsai, Yuchun; Lu, Bin; Ljubimov, Alexander V.; Girman, Sergey; Ross-Cisneros, Fred N.; Sadun, Alfredo A.; Svendsen, Clive N.; Cohen, Robert M.; Wang, Shaomei

    2014-01-01

    In this study, we observed pathological changes in the choroid and in RPE cells in the TgF344-AD rat model; choroidal thinning was further observed in human AD retina. Along with Aβ deposition, the inflammatory response was manifested by microglial recruitment and complement activation.

  15. Morphology of Ichthyophonus hoferi assessed by light and scanning electron microscopy

    DEFF Research Database (Denmark)

    Spanggaard, Bettina; Huss, Hans Henrik; Bresciani, J.

    1995-01-01

    The morphology of Ichthyophonus hoferi in vitro at pH 3.5 and 7.0 is described using light and scanning electron microscopy. Only vegetative growth was observed. At pH 3.5, hyphal growth was seen. The hyphae of I. hoferi are characterized by evacuated hyphal walls with the cytoplasm migrating......-walled multinucleate spores in the fish stomach as a response to the low pH. The hyphae then penetrate the digestive tract and rupture when they reach a blood vessel (neutral pH), whereby uni- and binucleate bodies and/or amoeboid bodies are released. The small cells are transported in the blood vessels and spread...

  16. Anti-Inflammatory Activities of Licorice Extract and Its Active Compounds, Glycyrrhizic Acid, Liquiritin and Liquiritigenin, in BV2 Cells and Mice Liver

    Directory of Open Access Journals (Sweden)

    Ji-Yeon Yu

    2015-07-01

    Full Text Available This study provides the scientific basis for the anti-inflammatory effects of licorice extract in a t-BHP (tert-butyl hydrogen peroxide-induced liver damage model and the effects of its ingredients, glycyrrhizic acid (GA, liquiritin (LQ and liquiritigenin (LG, in a lipopolysaccharide (LPS-stimulated microglial cell model. The GA, LQ and LG inhibited the LPS-stimulated elevation of pro-inflammatory mediators, such as inducible nitric oxide synthase (iNOS, cyclooxygenase-2 (COX-2, tumor necrosis factor (TNF-alpha, interleukin (IL-1beta and interleukin (IL-6 in BV2 (mouse brain microglia cells. Furthermore, licorice extract inhibited the expression levels of pro-inflammatory cytokines (TNF-α, IL-1β and IL-6 in the livers of t-BHP-treated mice models. This result suggested that mechanistic-based evidence substantiating the traditional claims of licorice extract and its three bioactive components can be applied for the treatment of inflammation-related disorders, such as oxidative liver damage and inflammation diseases.

  17. Microglia Modulate Wiring of the Embryonic Forebrain

    Directory of Open Access Journals (Sweden)

    Paola Squarzoni

    2014-09-01

    Full Text Available Dysfunction of microglia, the tissue macrophages of the brain, has been associated with the etiology of several neuropsychiatric disorders. Consistently, microglia have been shown to regulate neurogenesis and synaptic maturation at perinatal and postnatal stages. However, microglia invade the brain during mid-embryogenesis and thus could play an earlier prenatal role. Here, we show that embryonic microglia, which display a transiently uneven distribution, regulate the wiring of forebrain circuits. Using multiple mouse models, including cell-depletion approaches and cx3cr1−/−, CR3−/−, and DAP12−/− mutants, we find that perturbing microglial activity affects the outgrowth of dopaminergic axons in the forebrain and the laminar positioning of subsets of neocortical interneurons. Since defects in both dopamine innervation and cortical networks have been linked to neuropsychiatric diseases, our study provides insights into how microglial dysfunction can impact forebrain connectivity and reveals roles for immune cells during normal assembly of brain circuits.

  18. Vacuolating encephalitis in mice infected by human coronavirus OC43

    International Nuclear Information System (INIS)

    Jacomy, Helene; Talbot, Pierre J.

    2003-01-01

    Involvement of viruses in human neurodegenerative diseases and the underlying pathologic mechanisms remain generally unclear. Human respiratory coronaviruses (HCoV) can infect neural cells, persist in human brain, and activate myelin-reactive T cells. As a means of understanding the human infection, we characterized in vivo the neurotropic and neuroinvasive properties of HCoV-OC43 through the development of an experimental animal model. Virus inoculation of 21-day postnatal C57BL/6 and BALB/c mice led to a generalized infection of the whole CNS, demonstrating HCoV-OC43 neuroinvasiveness and neurovirulence. This acute infection targeted neurons, which underwent vacuolation and degeneration while infected regions presented strong microglial reactivity and inflammatory reactions. Damage to the CNS was not immunologically mediated and microglial reactivity was instead a consequence of direct virus-mediated neuronal injury. Although this acute encephalitis appears generally similar to that induced by murine coronaviruses, an important difference rests in the prominent spongiform-like degeneration that could trigger neuropathology in surviving animals

  19. Protective Effect of Cactus Cladode Extracts on Peroxisomal Functions in Microglial BV-2 Cells Activated by Different Lipopolysaccharides

    OpenAIRE

    Saih, Fatima-Ezzahra; Andreoletti, Pierre; Mandard, Stéphane; Latruffe, Norbert; El Kebbaj, M'Hammed Saïd; Lizard, Gérard; Nasser, Boubker; Cherkaoui-Malki, Mustapha

    2017-01-01

    International audience; In this study, we aimed to evaluate the antioxidant and anti-inflammatory properties of Opuntia ficus-indica cactus cladode extracts in microglia BV-2 cells. Inflammation associated with microglia activation in neuronal injury can be achieved by LPS exposure. Using four different structurally and biologically well-characterized LPS serotypes, we revealed a structure-related differential effect of LPS on fatty acid β-oxidation and antioxidant enzymes in peroxisomes: Esc...

  20. Receptor-heteromer mediated regulation of endocannabinoid signaling in activated microglia. Role of CB1 and CB2 receptors and relevance for Alzheimer's disease and levodopa-induced dyskinesia.

    Science.gov (United States)

    Navarro, Gemma; Borroto-Escuela, Dasiel; Angelats, Edgar; Etayo, Íñigo; Reyes-Resina, Irene; Pulido-Salgado, Marta; Rodríguez-Pérez, Ana I; Canela, Enric I; Saura, Josep; Lanciego, José Luis; Labandeira-García, José Luis; Saura, Carlos A; Fuxe, Kjell; Franco, Rafael

    2018-01-01

    Endocannabinoids are important regulators of neurotransmission and, acting on activated microglia, they are postulated as neuroprotective agents. Endocannabinoid action is mediated by CB 1 and CB 2 receptors, which may form heteromeric complexes (CB 1 -CB 2 Hets) with unknown function in microglia. We aimed at establishing the expression and signaling properties of cannabinoid receptors in resting and LPS/IFN-γ-activated microglia. In activated microglia mRNA transcripts increased (2 fold for CB 1 and circa 20 fold for CB 2 ), whereas receptor levels were similar for CB 1 and markedly upregulated for CB 2 ; CB 1 -CB 2 Hets were also upregulated. Unlike in resting cells, CB 2 receptors became robustly coupled to G i in activated cells, in which CB 1 -CB 2 Hets mediated a potentiation effect. Hence, resting cells were refractory while activated cells were highly responsive to cannabinoids. Interestingly, similar results were obtained in cultures treated with ß-amyloid (Aß 1-42 ). Microglial activation markers were detected in the striatum of a Parkinson's disease (PD) model and, remarkably, in primary microglia cultures from the hippocampus of mutant β-amyloid precursor protein (APP Sw,Ind ) mice, a transgenic Alzheimer's disease (AD) model. Also of note was the similar cannabinoid receptor signaling found in primary cultures of microglia from APP Sw,Ind and in cells from control animals activated using LPS plus IFN-γ. Expression of CB 1 -CB 2 Hets was increased in the striatum from rats rendered dyskinetic by chronic levodopa treatment. In summary, our results showed sensitivity of activated microglial cells to cannabinoids, increased CB 1 -CB 2 Het expression in activated microglia and in microglia from the hippocampus of an AD model, and a correlation between levodopa-induced dyskinesia and striatal microglial activation in a PD model. Cannabinoid receptors and the CB 1 -CB 2 heteroreceptor complex in activated microglia have potential as targets in the