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

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    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.

  2. Anthocyanin-rich açai (Euterpe oleracea Mart.) fruit pulp fractions attenuate inflammatory stress signaling in mouse brain BV-2 microglial cells.

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    Poulose, Shibu M; Fisher, Derek R; Larson, Jessica; Bielinski, Donna F; Rimando, Agnes M; Carey, Amanda N; Schauss, Alexander G; Shukitt-Hale, Barbara

    2012-02-01

    Age-related diseases of the brain compromise memory, learning, and movement and are directly linked with increases in oxidative stress and inflammation. Previous research has shown that supplementation with berries can modulate signaling in primary hippocampal neurons or BV-2 mouse microglial cells. Because of their high polyphenolic content, fruit pulp fractions of açai ( Euterpe oleracea Mart.) were explored for their protective effect on BV-2 mouse microglial cells. Freeze-dried açai pulp was fractionated using solvents with different polarities and analyzed using HPLC for major anthocyanins and other phenolics. Fractions extracted using methanol (MEOH) and ethanol (ETOH) were particularly rich in anthocyanins such as cyanidin, delphinidin, malvidin, pelargonidin, and peonidin, whereas the fraction extracted using acetone (ACE) was rich in other phenolics such as catechin, ferulic acid, quercetin, resveratrol, and synergic and vanillic acids. Studies were conducted to investigate the mitigating effects of açai pulp extracts on lipopolysaccharide (LPS, 100 ng/mL) induced oxidative stress and inflammation; treatment of BV-2 cells with acai fractions resulted in significant (p fractions. The protection of microglial cells by açai pulp extracts, particularly that of MEOH, ETOH, and ACE fractions, was also accompanied by a significant concentration-dependent reduction in cyclooxygenase-2 (COX-2), p38 mitogen-activated protein kinase (p38-MAPK), tumor necrosis factor-α (TNFα), and nuclear factor κB (NF-κB). The current study offers valuable insights into the protective effects of açai pulp fractions on brain cells, which could have implications for improved cognitive and motor functions.

  3. Aspirin-triggered lipoxin A4 attenuates LPS-induced pro-inflammatory responses by inhibiting activation of NF-κB and MAPKs in BV-2 microglial cells

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    Yuan Shi-Ying

    2011-08-01

    Full Text Available Abstract Background Microglial activation plays an important role in neurodegenerative diseases through production of nitric oxide (NO and several pro-inflammatory cytokines. Lipoxins (LXs and aspirin-triggered LXs (ATLs are considered to act as 'braking signals' in inflammation. In the present study, we investigated the effect of aspirin-triggered LXA4 (ATL on infiammatory responses induced by lipopolysaccharide (LPS in murine microglial BV-2 cells. Methods BV-2 cells were treated with ATL prior to LPS exposure, and the effects of such treatment production of nitric oxide (NO, inducible nitric oxide synthase (iNOS, interleukin-1β (IL-1β and tumour necrosis factor-α (TNF-α were analysed by Griess reaction, ELISA, western blotting and quantitative RT-PCR. Moreover, we investigated the effects of ATL on LPS-induced nuclear factor-κB (NF-κB activation, phosphorylation of mitogen-activated protein kinases (MAPKs and activator protein-1 (AP-1 activation. Results ATL inhibited LPS-induced production of NO, IL-1β and TNF-α in a concentration-dependent manner. mRNA expressions for iNOS, IL-1β and TNF-α in response to LPS were also decreased by ATL. These effects were inhibited by Boc-2 (a LXA4 receptor antagonist. ATL significantly reduced nuclear translocation of NF-κB p65, degradation of the inhibitor IκB-α, and phosphorylation of extracellular signal-regulated kinase (ERK and p38 MAPK in BV-2 cells activated with LPS. Furthermore, the DNA binding activity of NF-κB and AP-1 was blocked by ATL. Conclusions This study indicates that ATL inhibits NO and pro-inflammatory cytokine production at least in part via NF-κB, ERK, p38 MAPK and AP-1 signaling pathways in LPS-activated microglia. Therefore, ATL may have therapeutic potential for various neurodegenerative diseases.

  4. TGFβ produced by IL-10 re-directed Astrocytes Attenuates Microglial Activation

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    Norden, Diana M.; Fenn, Ashley M.; Dugan, Allison; Godbout, Jonathan P.

    2014-01-01

    While there clearly is an intimate relationship between astrocytes and microglia, few studies have examined these potentially dynamic interactions. In this study, cytokine-mediated communication between microglia and astrocytes under inflammatory conditions was investigated. We have previously shown that activated microglia produce Interleukin (IL)-10, a regulatory cytokine that plays an important role in resolving neuroinflammation. Nonetheless, the mechanism by which IL-10 attenuates pro-inflammatory cytokine expression in the brain is unclear. Here we show that IL-10 re-directed astrocytes regulate the activation of microglia in a Transforming growth factor (TGF)-β dependent manner. In support of this concept, astrocytes in the brain maintained higher IL-10 receptor (IL-10R1) expression and primary astrocytes in culture were markedly more sensitive to the anti-inflammatory effects of IL-10 compared to microglia. Moreover, studies using primary cultures and an astrocyte-microglia co-culture system revealed that astrocytes mediated the anti-inflammatory effects of IL-10 on microglia through the production of TGFβ. For instance, only when astrocytes were present did IL-10 stimulation reduce the expression of IL-1β and increase expression of anti-inflammatory mediators fractalkine receptor (CX3CR1) and interleukin 4 receptor-α (IL-4Rα) in microglia. Importantly, these IL-10-astrocyte dependent effects on microglia were blocked by a TGFβ inhibitor. Furthermore, inhibition of TGFβ signaling in the brain resulted in prolonged sickness behavior and amplified pro-inflammatory cytokine expression in mice challenged with lipopolysaccharide (LPS). Taken together, IL-10 stimulated the production of TGFβ by astrocytes, which in turn, attenuated microglial activation. Overall, these findings provide novel insight into the mechanisms by which astrocytes modulate microglia under inflammatory conditions. PMID:24616125

  5. Idazoxan attenuates spinal cord injury by enhanced astrocytic activation and reduced microglial activation in rat experimental autoimmune encephalomyelitis.

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    Wang, Xin-Shi; Chen, Yan-Yan; Shang, Xiao-Feng; Zhu, Zhen-Guo; Chen, Guo-Qian; Han, Zhao; Shao, Bei; Yang, Hui-Min; Xu, Hui-Qin; Chen, Jiang-Fan; Zheng, Rong-Yuan

    2009-02-09

    Idazoxan, an imidazoline 2 receptor (I(2)R) ligand, has been shown to protect against brain injury in several animal models of neurological disorders. In the present study we investigated the effect of idazoxan on experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. EAE was induced by immunizing Wistar rats with guinea pig spinal cord homogenates emulsified in CFA, followed by daily treatment of idazoxan (0, 0.5 mg/kg, 1.5 mg/kg, 4.5 mg/kg, i.p, bid) for 10 days. The results showed that the treatment of idazoxan (1.5 mg/kg and 4.5 mg/kg) significantly decreased the incidence and alleviated inflammatory cell infiltration and demyelination in spinal cords and cerebral cortex. Furthermore, the protective effect of idazoxan on EAE was associated with the enhanced astrocytic activation and attenuated microglial activation and with the subsequent down-regulated expression of proinflammatory cytokines IL-12p40 and IFN-gamma and up-regulated expression of anti-inflammatory cytokines IL-10 and TGF-beta(1). Thus, the daily treatment of the I(2)R ligand idazoxan for 10 days attenuates EAE pathology by differential modulation of astrocytic and microglial activations, raising a possibility that the I(2)R ligand may be a novel strategy for treating EAE.

  6. Trajectory of inflammatory and microglial activation markers in the postnatal rabbit brain following intrauterine endotoxin exposure.

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    Zhang, Zhi; Jyoti, Amar; Balakrishnan, Bindu; Williams, Monica; Singh, Sarabdeep; Chugani, Diane C; Kannan, Sujatha

    2018-03-01

    Maternal infection is a risk factor for periventricular leukomalacia and cerebral palsy (CP) in neonates. We have previously demonstrated hypomyelination and motor deficits in newborn rabbits, as seen in patients with cerebral palsy, following maternal intrauterine endotoxin administration. This was associated with increased microglial activation, primarily involving the periventricular region (PVR). In this study we hypothesized that maternal intrauterine inflammation leads to a pro-inflammatory environment in the PVR that is associated with microglial activation in the first 2 postnatal weeks. Timed pregnant New Zealand white rabbits underwent laparotomy on gestational day 28 (G28). They were randomly divided to receive lipopolysaccharide (LPS; 20μg/kg in 1mL saline) (Endotoxin group) or saline (1mL) (control saline, CS group), administrated along the wall of the uterus. The PVR from the CS and Endotoxin kits were harvested at G29 (1day post-injury), postnatal day1 (PND1, 3day post-injury) and PND5 (7days post-injury) for real-time PCR, ELISA and immunohistochemistry. Kits from CS and Endotoxin groups underwent longitudinal MicroPET imaging, with [ 11 C]PK11195, a tracer for microglial activation. We found that intrauterine endotoxin exposure resulted in pro-inflammatory microglial activation in the PVR of rabbits in the first postnatal week. This was evidenced by increased TSPO (translocator protein) expression co-localized with microglia/macrophages in the PVR, and changes in the microglial morphology (ameboid soma and retracted processes). In addition, CD11b level significantly increased with a concomitant decline in the CD45 level in the PVR at G29 and PND1. There was a significant elevation of pro-inflammatory cytokines and iNOS, and decreased anti-inflammatory markers in the Endotoxin kits at G29, PND1 and PND5. Increased [ 11 C]PK11195 binding to the TSPO measured in vivo by PET imaging in the brain of Endotoxin kits was present up to PND14-17. Our

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

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    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.

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

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    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.

  9. Naegleria fowleri lysate induces strong cytopathic effects and pro-inflammatory cytokine release in rat microglial cells.

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    Lee, Yang-Jin; Park, Chang-Eun; Kim, Jong-Hyun; Sohn, Hae-Jin; Lee, Jinyoung; Jung, Suk-Yul; Shin, Ho-Joon

    2011-09-01

    Naegleria fowleri, a ubiquitous free-living ameba, causes fatal primary amebic meningoencephalitis in humans. N. fowleri trophozoites are known to induce cytopathic changes upon contact with microglial cells, including necrotic and apoptotic cell death and pro-inflammatory cytokine release. In this study, we treated rat microglial cells with amebic lysate to probe contact-independent mechanisms for cytotoxicity, determining through a combination of light microscopy and scanning and transmission electron microscopy whether N. fowleri lysate could effect on both necrosis and apoptosis on microglia in a time- as well as dose-dependent fashion. A (51)Cr release assay demonstrated pronounced lysate induction of cytotoxicity (71.5%) toward microglial cells by 24 hr after its addition to cultures. In an assay of pro-inflammatory cytokine release, microglial cells treated with N. fowleri lysate produced TNF-α, IL-6, and IL-1β, though generation of the former 2 cytokines was reduced with time, and that of the last increased throughout the experimental period. In summary, N. fowleri lysate exerted strong cytopathic effects on microglial cells, and elicited pro-inflammatory cytokine release as a primary immune response.

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

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    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.

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

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    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.

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

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    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.

  13. Salicornia bigelovii Torr Attenuates Neuro-Inflammatory Responses ...

    African Journals Online (AJOL)

    BV- microglial cells were stimulated with LPS to study the protein expression and production of inflammatory mediators, determined by Western blot analysis. Results: SBE significantly inhibited the DPPH-generated free radicals showing maximum inhibition at 40 μg/mL (p < 0.001). SBE alone did not exhibit any signs of ...

  14. Methane Suppresses Microglial Activation Related to Oxidative, Inflammatory, and Apoptotic Injury during Spinal Cord Injury in Rats

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    WeiHeng Wang

    2017-01-01

    Full Text Available Objective. We investigated the hypothesis that methane-rich saline (MS can be used to repair spinal cord injury (SCI in a rat model through suppressing microglial activation related to oxidative, inflammatory, and apoptotic injury. Methods. MS was injected intraperitoneally in rats after SCI. Hematoxylin-eosin (HE staining, oxidative stress, inflammatory parameters, and cell apoptosis were detected 72 h after SCI to determine the optimal dose. Then, we investigated the protective mechanisms and the long-term effects of MS on SCI. HE and microglial activation were observed. Neurological function was evaluated by the Basso, Beattie, and Bresnahan (BBB scale. Results. MS can significantly decrease infarct area and inhibit oxidative stress, inflammation, and cell apoptosis 72 h following SCI. The MS protective effect at a dose of 20 ml/kg was better. Moreover, MS can significantly suppress microglial activation related to oxidative and inflammatory injury after SCI and improve hind limb neurological function. Conclusion. MS could repair SCI and reduce the release of oxidative stress, inflammatory cytokines, and cell apoptosis produced by activated microglia. MS provides a novel and promising strategy for the treatment of SCI.

  15. Low-power laser irradiation (LPLI) attenuates microglial cytotoxicity through the activation of Src pathway

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    Song, Sheng; Zhou, Feifan; Chen, Wei R.

    2014-02-01

    It has been known for a long time that microglial activation plays an important role in the pathology of neurodegenerative diseases. Once activated, they have macrophage-like capabilities, which can be detrimental by producing proinflammatory and neurotoxic factors including cytokines, reactive oxygen species (ROS) and nitric oxide that directly or indirectly cause neurodegeneration. Therefore, the regulation of microglial-induced neuroinflammation is considered a useful strategy in searching for neuroprotective treatments. In this study, our results showed that low power laser irradiation (LPLI) (20 J/cm2) could suppress microglial-induced neuroinflammation in LPS-activated microglia. We found that LPLI-mediated neuroprotection was achieved by activating tyrosine kinases Src, which led to MyD88 tyrosine phosphorylation, thus impairing MyD88-dependent proinflammatory signaling cascade. Our research may provide a feasible therapeutic approach to control the progression of neurodegenerative diseases.

  16. Excretory and Secretory Proteins of Naegleria fowleri Induce Inflammatory Responses in BV-2 Microglial Cells.

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    Lee, Jinyoung; Kang, Jung-Mi; Kim, Tae Im; Kim, Jong-Hyun; Sohn, Hae-Jin; Na, Byoung-Kuk; Shin, Ho-Joon

    2017-03-01

    Naegleria fowleri, a free-living amoeba that is found in diverse environmental habitats, can cause a type of fulminating hemorrhagic meningoencephalitis, primary amoebic meningoencephalitis (PAM), in humans. The pathogenesis of PAM is not fully understood, but it is likely to be primarily caused by disruption of the host's nervous system via a direct phagocytic mechanism by the amoeba. Naegleria fowleri trophozoites are known to secrete diverse proteins that may indirectly contribute to the pathogenic function of the amoeba, but this factor is not clearly understood. In this study, we analyzed the inflammatory responses in BV-2 microglial cells induced by excretory and secretory proteins of N. fowleri (NfESP). Treatment of BV-2 cells with NfESP induced the expression of various cytokines and chemokines, including the proinflammatory cytokines IL-1α and TNF-α. NfESP-induced IL-1α and TNF-α expression in BV-2 cells were regulated by p38, JNK, and ERK MAPKs. NfESP-induced IL-1α and TNF-α production in BV-2 cells were effectively downregulated by inhibition of NF-kB and AP-1. These results collectively suggest that NfESP stimulates BV-2 cells to release IL-1α and TNF-α via NF-kB- and AP-1-dependent MAPK signaling pathways. The released cytokines may contribute to inflammatory responses in microglia and other cell types in the brain during N. fowleri infection. © 2016 The Author(s) Journal of Eukaryotic Microbiology © 2016 International Society of Protistologists.

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

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    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.

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

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    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

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

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    Yao Linli

    2013-02-01

    Full Text Available Abstract 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

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

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    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.

  1. 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

  2. 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

  3. Roles of Microglial Phagocytosis and Inflammatory Mediators in the Pathophysiology of Sleep Disorders

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    Agnes Nadjar

    2017-08-01

    Full Text Available Sleep serves crucial learning and memory functions in both nervous and immune systems. Microglia are brain immune cells that actively maintain health through their crucial physiological roles exerted across the lifespan, including phagocytosis of cellular debris and orchestration of neuroinflammation. The past decade has witnessed an explosive growth of microglial research. Considering the recent developments in the field of microglia and sleep, we examine their possible impact on various pathological conditions associated with a gain, disruption, or loss of sleep in this focused mini-review. While there are extensive studies of microglial implication in a variety of neuropsychiatric and neurodegenerative diseases, less is known regarding their roles in sleep disorders. It is timely to stimulate new research in this emergent and rapidly growing field of investigation.

  4. Regulatory Effects of Fisetin on Microglial Activation

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    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.

  5. Mu-opioid receptor and delta-opioid receptor differentially regulate microglial inflammatory response to control proopiomelanocortin neuronal apoptosis in the hypothalamus: effects of neonatal alcohol.

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    Shrivastava, Pallavi; Cabrera, Miguel A; Chastain, Lucy G; Boyadjieva, Nadka I; Jabbar, Shaima; Franklin, Tina; Sarkar, Dipak K

    2017-04-14

    Opioid receptors are known to control neurotransmission of various peptidergic neurons, but their potential role in regulation of microglia and neuronal cell communications is unknown. We investigated the role of mu-opioid receptors (MOR) and delta-opioid receptors (DOR) on microglia in the regulation of apoptosis in proopiomelanocortin (POMC) neurons induced by neonatal ethanol in the hypothalamus. Neonatal rat pups were fed a milk formula containing ethanol or control diets between postnatal days 2-6. Some of the alcohol-fed rats additionally received pretreatment of a microglia activation blocker minocycline. Two hours after the last feeding, some of the pups were sacrificed and processed for histochemical detection of microglial cell functions or confocal microscopy for detection of cellular physical interaction or used for gene and protein expression analysis. The rest of the pups were dissected for microglia separation by differential gradient centrifugation and characterization by measuring production of various activation markers and cytokines. In addition, primary cultures of microglial cells were prepared using hypothalamic tissues of neonatal rats and used for determination of cytokine production/secretion and apoptotic activity of neurons. In the hypothalamus, neonatal alcohol feeding elevated cytokine receptor levels, increased the number of microglial cells with amoeboid-type circularity, enhanced POMC and microglial cell physical interaction, and decreased POMC cell numbers. Minocycline reversed these cellular effects of alcohol. Alcohol feeding also increased levels of microglia MOR protein and pro-inflammatory signaling molecules in the hypothalamus, and MOR receptor antagonist naltrexone prevented these effects of alcohol. In primary cultures of hypothalamic microglia, both MOR agonist [D-Ala 2, N-MePhe 4, Gly-ol]-enkephalin (DAMGO) and ethanol increased microglial cellular levels and secretion of pro-inflammatory cell signaling proteins. However

  6. [Zileuton, a 5-lipoxygenase inhibitor, attenuates mouse microglial cell-mediated rotenone toxicity in PC12 cells].

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    Zhang, Xiao-yan; Chen, Lu; Xu, Dong-min; Wang, Xiao-rong; Wang, Yan-fang; Li, Cheng-tan; Wei, Er-qing; Zhang, Li-hui

    2014-05-01

    To examine the effect of a selective inhibitor of 5-lipoxygenase (5-LOX) zileuton on microglia-mediated rotenone neurotoxicity. The supernatant from different concentrations of rotenone-stimulated mouse microglia BV2 cells was used as the conditioned media (CM) for PC12 cells. The viability of PC12 cells was determined by MTT assay and lactate dehydrogenase (LDH) release. Cell death was observed by LDH release and double fluorescence staining with Hoechst/propidiumiodide (PI). The effect of zileuton on microglia-mediated rotenone toxicity was evaluated by the above methods. Rotenone at 1-10 nmol/L was nontoxic to PC12 cells directly. However, the CM from BV2 cells that were treated with rotenone (1-10 nmol/L) resulted in toxicity of PC12 cells. The BV2 CM which stimulated with rotenone (1-10 nmol/L) induced morphological changes, reduced cell viability, and increased LDH release and cell necrosis in PC12 cells. Pretreatment of BV2 cells with the 5-LOX inhibitor zileuton (0.01-1 μmol/L) protected PC12 cells from the microglia-mediated rotenone toxicity. The 5-LOX inhibitor zileuton effectively attenuates microglia-mediated rotenone toxicity in PC12 cells. These results suggest that 5-LOX pathway may be involved in neuronal death induced by microglial inflammation.

  7. 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

  8. 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

  9. Activation of KCNN3/SK3/K(Ca)2.3 channels attenuates enhanced calcium influx and inflammatory cytokine production in activated microglia.

    Science.gov (United States)

    Dolga, Amalia M; Letsche, Till; Gold, Maike; Doti, Nunzianna; Bacher, Michael; Chiamvimonvat, Nipavan; Dodel, Richard; Culmsee, Carsten

    2012-12-01

    In neurons, small-conductance calcium-activated potassium (KCNN/SK/K(Ca)2) channels maintain calcium homeostasis after N-methyl-D-aspartate (NMDA) receptor activation, thereby preventing excitotoxic neuronal death. So far, little is known about the function of KCNN/SK/K(Ca)2 channels in non-neuronal cells, such as microglial cells. In this study, we addressed the question whether KCNN/SK/K(Ca)2 channels activation affected inflammatory responses of primary mouse microglial cells upon lipopolysaccharide (LPS) stimulation. We found that N-cyclohexyl-N-[2-(3,5-dimethyl-pyrazol-1-yl)-6-methyl-4-pyrimidinamine (CyPPA), a positive pharmacological activator of KCNN/SK/K(Ca)2 channels, significantly reduced LPS-stimulated activation of microglia in a concentration-dependent manner. The general KCNN/SK/K(Ca)2 channel blocker apamin reverted these effects of CyPPA on microglial proliferation. Since calcium plays a central role in microglial activation, we further addressed whether KCNN/SK/K(Ca)2 channel activation affected the changes of intracellular calcium levels, [Ca(2+)](i), in microglial cells. Our data show that LPS-induced elevation of [Ca(2+)](i) was attenuated following activation of KCNN2/3/K(Ca)2.2/K(Ca)2.3 channels by CyPPA. Furthermore, CyPPA reduced downstream events including tumor necrosis factor alpha and interleukin 6 cytokine production and nitric oxide release in activated microglia. Further, we applied specific peptide inhibitors of the KCNN/SK/K(Ca)2 channel subtypes to identify which particular channel subtype mediated the observed anti-inflammatory effects. Only inhibitory peptides targeting KCNN3/SK3/K(Ca)2.3 channels, but not KCNN2/SK2/K(Ca)2.2 channel inhibition, reversed the CyPPA-effects on LPS-induced microglial proliferation. These findings revealed that KCNN3/SK3/K(Ca)2.3 channels can modulate the LPS-induced inflammatory responses in microglial cells. Thus, KCNN3/SK3/K(Ca)2.3 channels may serve as a therapeutic target for reducing microglial

  10. Anti-inflammatory role of microglial alpha7 nAChRs and its role in neuroprotection.

    Science.gov (United States)

    Egea, Javier; Buendia, Izaskun; Parada, Esther; Navarro, Elisa; León, Rafael; Lopez, Manuela G

    2015-10-15

    Nicotinic acetylcholine receptors (nAChRs) are widely distributed throughout the central nervous system, being expressed in neurons and non-neuronal cells, where they participate in a variety of physiological responses like memory, learning, locomotion, attention, among others. We will focus on the α7 nAChR subtype, which has been implicated in neuroprotection, synaptic plasticity and neuronal survival, and is considered as a potential therapeutic target for several neurological diseases. Oxidative stress and neuroinflammation are currently considered as two of the most important pathological mechanisms common in neurodegenerative diseases such as Alzheimer, Parkinson or Huntington diseases. In this review, we will first analysed the distribution and expression of nAChR in mammalian brain. Then, we focused on the function of the α7 nAChR subtype in neuronal and non-neuronal cells and its role in immune responses (cholinergic anti-inflammatory pathway). Finally, we will revise the anti-inflammatory pathway promoted via α7 nAChR activation that is related to recruitment and activation of Jak2/STAT3 pathway, which on the one hand inhibits NF-κB nuclear translocation, and on the other hand, activates the master regulator of oxidative stress Nrf2/HO-1. This review provides a profound insight into the role of the α7 nAChR subtype in microglia and point out to microglial α7/HO-1 pathway as an anti-inflammatory therapeutic target. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. 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

  12. 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

  13. Natural Docosahexaenoic Acid in the Triglyceride Form Attenuates In Vitro Microglial Activation and Ameliorates Autoimmune Encephalomyelitis in Mice

    Directory of Open Access Journals (Sweden)

    Pilar Mancera

    2017-06-01

    Full Text Available Many neurodegenerative diseases are associated, at least in part, to an inflammatory process in which microglia plays a major role. The effect of the triglyceride form of the omega-3 polyunsaturated fatty acid docosahexaenoic acid (TG-DHA was assayed in vitro and in vivo to assess the protective and anti-inflammatory activity of this compound. In the in vitro study, BV-2 microglia cells were previously treated with TG-DHA and then activated with Lipopolysaccharide (LPS and Interferon-gamma (IFN-γ. TG-DHA treatment protected BV-2 microglia cells from oxidative stress toxicity attenuating NO production and suppressing the induction of inflammatory cytokines. When compared with DHA in the ethyl-ester form, a significant difference in the ability to inhibit NO production in favor of TG-DHA was observed. TG-DHA inhibited significantly splenocyte proliferation but isolated CD4+ lymphocyte proliferation was unaffected. In a mice model of autoimmune encephalomyelitis (EAE, 250 mg/kg/day oral TG-DHA treatment was associated with a significant amelioration of the course and severity of the disease as compared to untreated animals. TG-DHA-treated EAE mice showed a better weight profile, which is a symptom related to a better course of encephalomyelitis. TG-DHA may be a promising therapeutic agent in neuroinflammatory processes and merit to be more extensively studied in human neurodegenerative disorders.

  14. 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.

  15. Koumine Attenuates Neuroglia Activation and Inflammatory Response to Neuropathic Pain

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    Gui-Lin Jin

    2018-01-01

    Full Text Available Despite decades of studies, the currently available drugs largely fail to control neuropathic pain. Koumine—an alkaloidal constituent derived from the medicinal plant Gelsemium elegans Benth.—has been shown to possess analgesic and anti-inflammatory properties; however, the underlying mechanisms remain unclear. In this study, we aimed to investigate the analgesic and anti-inflammatory effects and the possible underlying mechanisms of koumine. The analgesic and anti-inflammatory effects of koumine were explored by using chronic constriction injury of the sciatic nerve (CCI neuropathic pain model in vivo and LPS-induced injury in microglia BV2 cells in vitro. Immunofluorescence staining and Western blot analysis were used to assess the modulator effect of koumine on microglia and astrocyte activation after CCI surgery. Enzyme-linked immunosorbent assay (ELISA was used to evaluate the levels of proinflammatory cytokines. Western blot analysis and quantitative real-time polymerase chain reaction (qPCR were used to examine the modulator effect of koumine on microglial M1 polarization. We found that single or repeated treatment of koumine can significantly reduce neuropathic pain after nerve injury. Moreover, koumine showed inhibitory effects on CCI-evoked microglia and astrocyte activation and reduced proinflammatory cytokine production in the spinal cord in rat CCI models. In BV2 cells, koumine significantly inhibited microglia M1 polarization. Furthermore, the analgesic effect of koumine was inhibited by a TSPO antagonist PK11195. These findings suggest that the analgesic effects of koumine on CCI-induced neuropathic pain may result from the inhibition of microglia activation and M1 polarization as well as the activation of astrocytes while sparing the anti-inflammatory responses to neuropathic pain.

  16. 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.

  17. 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.

  18. 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

  19. Deletion of the Inflammasome Sensor Aim2 Mitigates Aβ Deposition and Microglial Activation but Increases Inflammatory Cytokine Expression in an Alzheimer Disease Mouse Model.

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    Wu, Pei-Jung; Hung, Yun-Fen; Liu, Hsin-Yu; Hsueh, Yi-Ping

    2017-01-01

    Inflammation is clearly associated with Alzheimer disease (AD). Knockout of Nlrp3, a gene encoding an inflammasome sensor, has been shown to ameliorate AD pathology in a mouse model. Because AIM2 is the most dominant inflammasome sensor expressed in mouse brains, here we investigate whether Aim2 deletion also influences the phenotype of a 5XFAD AD mouse model. Quantitative RT-PCR, immunostaining, immunoblotting, and behavioral analyses were applied to compare wild-type, Aim2-/-, 5XFAD, and Aim2-/-;5XFAD mice. We found that Aim2 knockout mitigates Aβ deposition in the cerebral cortex and hippocampus of 5XFAD mice. The activation of microglial cells is also reduced in Aim2-/-;5XFAD brains compared with 5XFAD brains. However, Aim2 knockout does not improve memory and anxiety phenotypes of 5XFAD mice in an open field, cued Y-maze, or Barnes maze. Compared with 5XFAD mice, Il-1 expression levels are not reduced in Aim2-/-;5XFAD mice. Unexpectedly, Il-6 and Il-18 expression levels in 5XFAD brains were further increased when Aim2 was deleted. Thus, inflammatory cytokine expression in 5XFAD brains is upregulated by Aim2 deletion through an unknown mechanism. Although Aim2 knockout mitigates Aβ deposition and microglial activation, Aim2 deletion does not have a beneficial effect on the spatial memory or cytokine expression of 5XFAD mice. Our findings suggest that Aβ aggregation and microglial activation may not always be correlated with the expression of inflammatory cytokines or cognitive function of 5XFAD mice. Our study also implies that different inflammasomes likely perform distinct roles in different physiological and/or pathological events. © 2017 S. Karger AG, Basel.

  20. 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.

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    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.

  1. 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

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    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

  2. Donepezil Regulates 1-Methyl-4-phenylpyridinium-Induced Microglial Polarization in Parkinson's Disease.

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    Chen, Teng; Hou, Ruihua; Xu, Shujun; Wu, Chengyuan

    2015-10-21

    1-Methyl-4-phenylpyridinium (MPP+) induces microglial activation and degeneration of dopaminergic (DAergic) neurons. Donepezil is a well-known acetylcholinesterase inhibitor used clinically to treat cognitive dysfunction in Alzheimer's disease (AD). In the present study, we tested the hypothesis that MPP+ promotes microglial M1 polarization and suppresses M2 polarization and that this can be restored by donepezil. Results indicate that MPP+ treatment in microglial BV2 cells promotes microglial polarization toward the M1 state. However, pretreatment with donepezil inhibited MPP+-induced M1 polarization in microglia by suppressing the release of interleukin (IL)-6, IL-1β, or tumor necrosis factor (TNF)-α. Importantly, we found that MPP+ inhibited microglial M2 polarization by suppressing expression of Arg-1, Fizz1, and Ym1, which was also rescued by pretreatment with donepezil. In addition, IL-4-mediated induction of anti-inflammatory marker genes IL-10, IL-13, and transforming growth factor-β2 (TGF-β2) were significantly attenuated by MPP+ in BV2 cells, which was restored by pretreatment with donepezil in a concentration-dependent manner. Mechanistically, we found that the addition of MPP+ reduced the intensity of phosphorylated signal transducer and activator of transcription 6 (STAT6) but not total STAT6 in IL-4-stimulated BV2 cells. Importantly, pretreatment of microglial BV2 cells with donepezil 3 h prior to administration of MPP+ rescued the reduction of STAT6 phosphorylation induced by MPP+.

  3. trans-Cinnamaldehyde Inhibits Microglial Activation and Improves Neuronal Survival against Neuroinflammation in BV2 Microglial Cells with Lipopolysaccharide Stimulation

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    Yan Fu

    2017-01-01

    Full Text Available Background. Microglial activation contributes to neuroinflammation and neuronal damage in neurodegenerative disorders including Alzheimer’s and Parkinson’s diseases. It has been suggested that neurodegenerative disorders may be improved if neuroinflammation can be controlled. trans-cinnamaldehyde (TCA isolated from the stem bark of Cinnamomum cassia possesses potent anti-inflammatory capability; we thus tested whether TCA presents neuroprotective effects on improving neuronal survival by inhibiting neuroinflammatory responses in BV2 microglial cells. Results. To determine the molecular mechanism behind TCA-mediated neuroprotective effects, we assessed the effects of TCA on lipopolysaccharide- (LPS- induced proinflammatory responses in BV2 microglial cells. While LPS potently induced the production and expression upregulation of proinflammatory mediators, including NO, iNOS, COX-2, IL-1β, and TNF-α, TCA pretreatment significantly inhibited LPS-induced production of NO and expression of iNOS, COX-2, and IL-1β and recovered the morphological changes in BV2 cells. TCA markedly attenuated microglial activation and neuroinflammation by blocking nuclear factor kappa B (NF-κB signaling pathway. With the aid of microglia and neuron coculture system, we showed that TCA greatly reduced LPS-elicited neuronal death and exerted neuroprotective effects. Conclusions. Our results suggest that TCA, a natural product, has the potential of being used as a therapeutic agent against neuroinflammation for ameliorating neurodegenerative disorders.

  4. Okanin, effective constituent of the flower tea Coreopsis tinctoria, attenuates LPS-induced microglial activation through inhibition of the TLR4/NF-κB signaling pathways

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    Hou, Yue; Li, Guoxun; Wang, Jian; Pan, Yingni; Jiao, Kun; Du, Juan; Chen, Ru; Wang, Bing; Li, Ning

    2017-04-01

    The EtOAc extract of Coreopsis tinctoria Nutt. significantly inhibited LPS-induced nitric oxide (NO) production, as judged by the Griess reaction, and attenuated the LPS-induced elevation in iNOS, COX-2, IL-1β, IL-6 and TNF-α mRNA levels, as determined by quantitative real-time PCR, when incubated with BV-2 microglial cells. Immunohistochemical results showed that the EtOAc extract significantly decreased the number of Iba-1-positive cells in the hippocampal region of LPS-treated mouse brains. The major effective constituent of the EtOAc extract, okanin, was further investigated. Okanin significantly suppressed LPS-induced iNOS expression and also inhibited IL-6 and TNF-α production and mRNA expression in LPS-stimulated BV-2 cells. Western blot analysis indicated that okanin suppressed LPS-induced activation of the NF-κB signaling pathway by inhibiting the phosphorylation of IκBα and decreasing the level of nuclear NF-κB p65 after LPS treatment. Immunofluorescence staining results showed that okanin inhibited the translocation of the NF-κB p65 subunit from the cytosol to the nucleus. Moreover, okanin significantly inhibited LPS-induced TLR4 expression in BV-2 cells. In summary, okanin attenuates LPS-induced activation of microglia. This effect may be associated with its capacity to inhibit the TLR4/NF-κB signaling pathways. These results suggest that okanin may have potential as a nutritional preventive strategy for neurodegenerative disorders.

  5. Pilose antler peptide attenuates LPS-induced inflammatory reaction.

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    Dong, Yu; Liu, Li; Shan, Xin; Tang, Juanjuan; Xia, Baomei; Cheng, Xiaolan; Chen, Yanyan; Tao, Weiwei

    2018-03-01

    The present study was designed to study the effects of pilose antler peptide (PAP) on primary culture of nucleus pulposus cells in intervertebral disc. We demonstrated that PAP significantly inhibited lipopolysaccharides (LPS) induced over-production of inflammatory factors including interleukin-1β (IL-1β), tumor necrosis Factor-α (TNF-α) and interleukin-6 (IL-6) in nucleus pulposus cells. PAP also attenuated increase of malondialdehyde (MDA) and decrease of superoxide dismutase (SOD) induced by LPS challenge in a concentration-dependent manner. Moreover, the expression of the protein levels of mitogen-activated protein kinase (MAPK)/nuclear transcription factor-κB(NF-κB) were increased accompanying with the LPS challenge, which were significantly reversed after PAP treatment. Our results demonstrated the ability of PAP to antagonize LPS-mediated inflammation in primary culture of nucleus pulposus in intervertebral disc, suggesting a beneficial potential for its clinical application. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. 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

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    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

  7. Activation of microglial NADPH oxidase is synergistic with glial iNOS expression in inducing neuronal death: a dual-key mechanism of inflammatory neurodegeneration

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    Brown Guy C

    2005-09-01

    Full Text Available Abstract Background Inflammation-activated glia are seen in many CNS pathologies and may kill neurons through the release of cytotoxic mediators, such as nitric oxide from inducible NO synthase (iNOS, and possibly superoxide from NADPH oxidase (NOX. We set out to determine the relative role of these species in inducing neuronal death, and to test the dual-key hypothesis that the production of both species simultaneously is required for significant neuronal death. Methods Primary co-cultures of cerebellar granule neurons and glia from rats were used to investigate the effect of NO (from iNOS, following lipopolysaccharide (LPS and/or cytokine addition or superoxide/hydrogen peroxide (from NOX, following phorbol 12-myristate 13-acetate (PMA, ATP analogue (BzATP, interleukin-1β (IL-1β or arachidonic acid (AA addition on neuronal survival. Results Induction of glial iNOS caused little neuronal death. Similarly, activation of NOX alone resulted in little or no neuronal death. However, if NOX was activated (by PMA or BzATP in the presence of iNOS (induced by LPS and interferon-γ then substantial delayed neuronal death occurred over 48 hours, which was prevented by inhibitors of iNOS (1400W, NOX (apocynin or a peroxynitrite decomposer (FeTPPS. Neurons and glia were also found to stain positive for nitrotyrosine (a putative marker of peroxynitrite only when both iNOS and NOX were simultaneously active. If NOX was activated by weak stimulators (IL-1β, AA or the fibrillogenic prion peptide PrP106-126 in the presence of iNOS, it caused microglial proliferation and delayed neurodegeneration over 6 days, which was prevented by iNOS or NOX inhibitors, a peroxynitrite decomposer or a NMDA-receptor antagonist (MK-801. Conclusion These results suggest a dual-key mechanism, whereby glial iNOS or microglial NOX activation alone is relatively benign, but if activated simultaneously are synergistic in killing neurons, through generating peroxynitrite. This

  8. Omega-3 polyunsaturated fatty acid attenuates the inflammatory response by modulating microglia polarization through SIRT1-mediated deacetylation of the HMGB1/NF-κB pathway following experimental traumatic brain injury.

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    Chen, Xiangrong; Chen, Chunnuan; Fan, Sining; Wu, Shukai; Yang, Fuxing; Fang, Zhongning; Fu, Huangde; Li, Yasong

    2018-04-20

    development of the neuroinflammatory response after TBI. The results of our study showed that ω-3 PUFA supplementation promoted a shift from the M1 microglial phenotype to the M2 microglial phenotype and inhibited microglial activation, thus reducing TBI-induced inflammatory factors. In addition, ω-3 PUFA-mediated downregulation of HMGB1 acetylation and its extracellular secretion was found to be likely due to increased SIRT1 activity. We also found that treatment with ω-3 PUFA inhibited HMGB1 acetylation and induced direct interactions between SIRT1 and HMGB1 by elevating SIRT1 activity following TBI. These events lead to inhibition of HMGB1 nucleocytoplasmic translocation/extracellular secretion and alleviated HMGB1-mediated activation of the NF-κB pathway following TBI-induced microglial activation, thus inhibiting the subsequent inflammatory response. The results of this study suggest that ω-3 PUFA supplementation attenuates the inflammatory response by modulating microglial polarization through SIRT1-mediated deacetylation of the HMGB1/NF-κB pathway, leading to neuroprotective effects following experimental traumatic brain injury.

  9. Opioid Self-Administration is Attenuated by Early-Life Experience and Gene Therapy for Anti-Inflammatory IL-10 in the Nucleus Accumbens of Male Rats.

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    Lacagnina, Michael J; Kopec, Ashley M; Cox, Stewart S; Hanamsagar, Richa; Wells, Corinne; Slade, Susan; Grace, Peter M; Watkins, Linda R; Levin, Edward D; Bilbo, Staci D

    2017-10-01

    Early-life conditions can contribute to the propensity for developing neuropsychiatric disease, including substance abuse disorders. However, the long-lasting mechanisms that shape risk or resilience for drug addiction remain unclear. Previous work has shown that a neonatal handling procedure in rats (which promotes enriched maternal care) attenuates morphine conditioning, reduces morphine-induced glial activation, and increases microglial expression of the anti-inflammatory cytokine interleukin-10 (IL-10). We thus hypothesized that anti-inflammatory signaling may underlie the effects of early-life experience on later-life opioid drug-taking. Here we demonstrate that neonatal handling attenuates intravenous self-administration of the opioid remifentanil in a drug-concentration-dependent manner. Transcriptional profiling of the nucleus accumbens (NAc) from handled rats following repeated exposure to remifentanil reveals a suppression of pro-inflammatory cytokine and chemokine gene expression, consistent with an anti-inflammatory phenotype. To determine if anti-inflammatory signaling alters drug-taking behavior, we administered intracranial injections of plasmid DNA encoding IL-10 (pDNA-IL-10) into the NAc of non-handled rats. We discovered that pDNA-IL-10 treatment reduces remifentanil self-administration in a drug-concentration-dependent manner, similar to the effect of handling. In contrast, neither handling nor pDNA-IL-10 treatment alters self-administration of food or sucrose rewards. These collective observations suggest that neuroimmune signaling mechanisms in the NAc are shaped by early-life experience and may modify motivated behaviors for opioid drugs. Moreover, manipulation of the IL-10 signaling pathway represents a novel approach for influencing opioid reinforcement.

  10. Contemporary views on inflammatory pain mechanisms: TRPing over innate and microglial pathways [version 1; referees: 3 approved

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    Zhonghui Guan

    2016-09-01

    Full Text Available Tissue injury, whether by trauma, surgical intervention, metabolic dysfunction, ischemia, or infection, evokes a complex cellular response (inflammation that is associated with painful hyperalgesic states. Although in the acute stages it is necessary for protective reflexes and wound healing, inflammation may persist well beyond the need for tissue repair or survival. Prolonged inflammation may well represent the greatest challenge mammalian organisms face, as it can lead to chronic painful conditions, organ dysfunction, morbidity, and death. The complexity of the inflammatory response reflects not only the inciting event (infection, trauma, surgery, cancer, or autoimmune but also the involvement of heterogeneous cell types including neuronal (primary afferents, sensory ganglion, and spinal cord, non-neuronal (endothelial, keratinocytes, epithelial, and fibroblasts, and immune cells. In this commentary, we will examine 1. the expression and regulation of two members of the transient receptor potential family in primary afferent nociceptors and their activation/regulation by products of inflammation, 2. the role of innate immune pathways that drive inflammation, and 3. the central nervous system’s response to injury with a focus on the activation of spinal microglia driving painful hyperalgesic states.

  11. Mineralocorticoid and glucocorticoid receptors differentially regulate NF-kappaB activity and pro-inflammatory cytokine production in murine BV-2 microglial cells

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    Chantong Boonrat

    2012-11-01

    Full Text Available Abstract Background Microglia, the resident macrophage-like cells in the brain, regulate innate immune responses in the CNS to protect neurons. However, excessive activation of microglia contributes to neurodegenerative diseases. Corticosteroids are potent modulators of inflammation and mediate their effects by binding to mineralocorticoid receptors (MR and glucocorticoid receptors (GR. Here, the coordinated activities of GR and MR on the modulation of the nuclear factor-κB (NF-κB pathway in murine BV-2 microglial cells were studied. Methods BV-2 cells were treated with different corticosteroids in the presence or absence of MR and GR antagonists. The impact of the glucocorticoid-activating enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1 was determined by incubating cells with 11-dehydrocorticosterone, with or without selective inhibitors. Expression of interleukin-6 (IL-6, tumor necrosis factor receptor 2 (TNFR2, and 11β-HSD1 mRNA was analyzed by RT-PCR and IL-6 protein expression by ELISA. NF-κB activation and translocation upon treatment with various corticosteroids were visualized by western blotting, immunofluorescence microscopy, and translocation assays. Results GR and MR differentially regulate NF-κB activation and neuroinflammatory parameters in BV-2 cells. By converting inactive 11-dehydrocorticosterone to active corticosterone, 11β-HSD1 essentially modulates the coordinated action of GR and MR. Biphasic effects were observed for 11-dehydrocorticosterone and corticosterone, with an MR-dependent potentiation of IL-6 and tumor necrosis factor-α (TNF-α expression and NF-κB activation at low/moderate concentrations and a GR-dependent suppression at high concentrations. The respective effects were confirmed using the MR ligand aldosterone and the antagonist spironolactone as well as the GR ligand dexamethasone and the antagonist RU-486. NF-κB activation could be blocked by spironolactone and the inhibitor of NF

  12. Hypoxia attenuates purinergic P2X receptor-induced inflammatory gene expression in brainstem microglia

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    Smith SMC

    2013-08-01

    Full Text Available Stephanie MC Smith,1,2 Gordon S Mitchell,1,2 Scott A Friedle,3 Christine M Sibigtroth,1 Stéphane Vinit,1 Jyoti J Watters1–31Department of Comparative Biosciences, 2Comparative Biomedical Sciences Training Program, 3Program in Cellular and Molecular Biology, University of Wisconsin, Madison, WI, USAAbstract: Hypoxia and increased extracellular nucleotides are frequently coincident in the brainstem. Extracellular nucleotides are potent modulators of microglial inflammatory gene expression via P2X purinergic receptor activation. Although hypoxia is also known to modulate inflammatory gene expression, little is known about how hypoxia or P2X receptor activation alone affects inflammatory molecule production in brainstem microglia, nor how hypoxia and P2X receptor signaling interact when they occur together. In the study reported here, we investigated the ability of a brief episode of hypoxia (2 hours in the presence and absence of the nonselective P2X receptor agonist 2′(3′-O-(4-benzoylbenzoyladenosine-5′-triphosphate (BzATP to promote inflammatory gene expression in brainstem microglia in adult rats. We evaluated inducible nitric oxide synthase (iNOS, tumor necrosis factor alpha (TNFα, and interleukin (IL-6 messenger RNA levels in immunomagnetically isolated brainstem microglia. While iNOS and IL-6 gene expression increased with hypoxia and BzATP alone, TNFα expression was unaffected. Surprisingly, BzATP-induced inflammatory effects were lost after hypoxia, suggesting that hypoxia impairs proinflammatory P2X-receptor signaling. We also evaluated the expression of key P2X receptors activated by BzATP, namely P2X1, P2X4, and P2X7. While hypoxia did not alter their expression, BzATP upregulated P2X4 and P2X7 mRNAs; these effects were ablated in hypoxia. Although both P2X4 and P2X7 receptor expression correlated with increased microglial iNOS and IL-6 levels in microglia from normoxic rats, in hypoxia, P2X7 only correlated with IL-6, and P2X

  13. Cortistatin attenuates inflammatory pain via spinal and peripheral actions.

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    Morell, María; Camprubí-Robles, María; Culler, Michael D; de Lecea, Luis; Delgado, Mario

    2014-03-01

    Clinical pain, as a consequence of inflammation or injury of peripheral organs (inflammatory pain) or nerve injury (neuropathic pain), represents a serious public health issue. Treatment of pain-related suffering requires knowledge of how pain signals are initially interpreted and subsequently transmitted and perpetuated. To limit duration and intensity of pain, inhibitory signals participate in pain perception. Cortistatin is a cyclic-neuropeptide that exerts potent inhibitory actions on cortical neurons and immune cells. Here, we found that cortistatin is a natural analgesic component of the peripheral nociceptive system produced by peptidergic nociceptive neurons of the dorsal root ganglia in response to inflammatory and noxious stimuli. Moreover, cortistatin is produced by GABAergic interneurons of deep layers of dorsal horn of spinal cord. By using cortistatin-deficient mice, we demonstrated that endogenous cortistatin critically tunes pain perception in physiological and pathological states. Furthermore, peripheral and spinal injection of cortistatin potently reduced nocifensive behavior, heat hyperalgesia and tactile allodynia in experimental models of clinical pain evoked by chronic inflammation, surgery and arthritis. The analgesic effects of cortistatin were independent of its anti-inflammatory activity and directly exerted on peripheral and central nociceptive terminals via Gαi-coupled somatostatin-receptors (mainly sstr2) and blocking intracellular signaling that drives neuronal plasticity including protein kinase A-, calcium- and Akt/ERK-mediated release of nociceptive peptides. Moreover, cortistatin could modulate, through its binding to ghrelin-receptor (GHSR1), pain-induced sensitization of secondary neurons in spinal cord. Therefore, cortistatin emerges as an anti-inflammatory factor with potent analgesic effects that offers a new approach to clinical pain therapy, especially in inflammatory states. Copyright © 2013 Elsevier Inc. All rights

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

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    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

  15. Microglial interleukin-1β in the ipsilateral dorsal horn inhibits the development of mirror-image contralateral mechanical allodynia through astrocyte activation in a rat model of inflammatory pain.

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    Choi, Hoon-Seong; Roh, Dae-Hyun; Yoon, Seo-Yeon; Moon, Ji-Young; Choi, Sheu-Ran; Kwon, Soon-Gu; Kang, Suk-Yun; Han, Ho-Jae; Kim, Hyun-Woo; Beitz, Alvin J; Oh, Seog-Bae; Lee, Jang-Hern

    2015-06-01

    Damage on one side of the body can also result in pain on the contralateral unaffected side, called mirror-image pain (MIP). Currently, the mechanisms responsible for the development of MIP are unknown. In this study, we investigated the involvement of spinal microglia and interleukin-1β (IL-1β) in the development of MIP using a peripheral inflammatory pain model. After unilateral carrageenan injection, mechanical allodynia (MA) in both hind paws and the expression levels of spinal Iba-1, IL-1β, and GFAP were evaluated. Ipsilateral MA was induced beginning at 3 hours after carrageenan injection, whereas contralateral MA showed a delayed onset occurring 5 days after injection. A single intrathecal (i.t.) injection of minocycline, a tetracycline derivative that displays selective inhibition of microglial activation, or an interleukin-1 receptor antagonist (IL-1ra) on the day of carrageenan injection caused an early temporary induction of contralateral MA, whereas repeated i.t. treatment with these drugs from days 0 to 3 resulted in a long-lasting contralateral MA, which was evident in its advanced development. We further showed that IL-1β was localized to microglia and that minocycline inhibited the carrageenan-induced increases in spinal Iba-1 and IL-1β expression. Conversely, minocycline or IL-1ra pretreatment increased GFAP expression as compared with that of control rats. However, i.t. pretreatment with fluorocitrate, an astrocyte inhibitor, restored minocycline- or IL-1ra-induced contralateral MA. These results suggest that spinal IL-1β derived from activated microglia temporarily suppresses astrocyte activation, which can ultimately prevent the development of contralateral MA under inflammatory conditions. These findings imply that microglial IL-1β plays an important role in regulating the induction of inflammatory MIP.

  16. Inflammatory arthritis and systemic bone loss are attenuated by gastrointestinal helminth parasites.

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    Sarter, Kerstin; Kulagin, Manuel; Schett, Georg; Harris, Nicola L; Zaiss, Mario M

    2017-05-01

    Infections with different helminth species have been observed to ameliorate a variety of chronic inflammatory diseases. Herein, we show that the natural murine helminth species, Heligmosomoides polygyrus bakeri (Hp) is capable of attenuating disease severity in two different inflammatory arthritis models. Furthermore, we show that excretory-secretory (ES) products from Hp directly suppress osteoclast differentiation in vitro. Taken together, these results demonstrate that helminth infections can dampen autoimmune diseases and highlight a previously unrecognized and important role for ES products, by directly impacting on bone destruction.

  17. Neonatal overfeeding attenuates acute central pro-inflammatory effects of short-term high fat diet

    Directory of Open Access Journals (Sweden)

    Guohui eCai

    2015-01-01

    Full Text Available Neonatal obesity predisposes individuals to obesity throughout life. In rats, neonatal overfeeding also leads to early accelerated weight gain that persists into adulthood. The phenotype is associated with dysfunction in a number of systems including paraventricular nucleus of the hypothalamus (PVN responses to psychological and immune stressors. However, in many cases weight gain in neonatally overfed rats stabilizes in early adulthood so the animal does not become more obese as it ages. Here we examined if neonatal overfeeding by suckling rats in small litters predisposes them to exacerbated metabolic and central inflammatory disturbances if they are also given a high fat diet in later life. In adulthood we gave the rats normal chow, 3 days, or 3 weeks high fat diet (45% kcal from fat and measured peripheral indices of metabolic disturbance. We also investigated hypothalamic microglial changes, as an index of central inflammation, as well as PVN responses to lipopolysaccharide (LPS. Surprisingly, neonatal overfeeding did not predispose rats to the metabolic effects of a high fat diet. Weight changes and glucose metabolism were unaffected by the early life experience. However, short term (3 day high fat diet was associated with more microglia in the hypothalamus and a markedly exacerbated PVN response to LPS in control rats; effects not seen in the neonatally overfed. Our findings indicate neonatally overfed animals are not more susceptible to the adverse metabolic effects of a short-term high fat diet but may be less able to respond to the central effects.

  18. Early-life experience decreases drug-induced reinstatement of morphine CPP in adulthood via microglial-specific epigenetic programming of anti-inflammatory IL-10 expression.

    Science.gov (United States)

    Schwarz, Jaclyn M; Hutchinson, Mark R; Bilbo, Staci D

    2011-12-07

    A critical component of drug addiction research involves identifying novel biological mechanisms and environmental predictors of risk or resilience to drug addiction and associated relapse. Increasing evidence suggests microglia and astrocytes can profoundly affect the physiological and addictive properties of drugs of abuse, including morphine. We report that glia within the rat nucleus accumbens (NAcc) respond to morphine with an increase in cytokine/chemokine expression, which predicts future reinstatement of morphine conditioned place preference (CPP) following a priming dose of morphine. This glial response to morphine is influenced by early-life experience. A neonatal handling paradigm that increases the quantity and quality of maternal care significantly increases baseline expression of the anti-inflammatory cytokine IL-10 within the NAcc, attenuates morphine-induced glial activation, and prevents the subsequent reinstatement of morphine CPP in adulthood. IL-10 expression within the NAcc and reinstatement of CPP are negatively correlated, suggesting a protective role for this specific cytokine against morphine-induced glial reactivity and drug-induced reinstatement of morphine CPP. Neonatal handling programs the expression of IL-10 within the NAcc early in development, and this is maintained into adulthood via decreased methylation of the IL-10 gene specifically within microglia. The effect of neonatal handling is mimicked by pharmacological modulation of glia in adulthood with ibudilast, which increases IL-10 expression, inhibits morphine-induced glial activation within the NAcc, and prevents reinstatement of morphine CPP. Taken together, we have identified a novel gene × early-life environment interaction on morphine-induced glial activation and a specific role for glial activation in drug-induced reinstatement of drug-seeking behavior.

  19. Wound trauma mediated inflammatory signaling attenuates a tissue regenerative response in MRL/MpJ mice

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    Elster Eric A

    2010-05-01

    Full Text Available Abstract Background Severe trauma can induce pathophysiological responses that have marked inflammatory components. The development of systemic inflammation following severe thermal injury has been implicated in immune dysfunction, delayed wound healing, multi-system organ failure and increased mortality. Methods In this study, we examined the impact of thermal injury-induced systemic inflammation on the healing response of a secondary wound in the MRL/MpJ mouse model, which was anatomically remote from the primary site of trauma, a wound that typically undergoes scarless healing in this specific strain. Ear-hole wounds in MRL/MpJ mice have previously displayed accelerated healing and tissue regeneration in the absence of a secondary insult. Results Severe thermal injury in addition to distal ear-hole wounds induced marked local and systemic inflammatory responses in the lungs and significantly augmented the expression of inflammatory mediators in the ear tissue. By day 14, 61% of the ear-hole wounds from thermally injured mice demonstrated extensive inflammation with marked inflammatory cell infiltration, extensive ulceration, and various level of necrosis to the point where a large percentage (38% had to be euthanized early during the study due to extensive necrosis, inflammation and ear deformation. By day 35, ear-hole wounds in mice not subjected to thermal injury were completely closed, while the ear-hole wounds in thermally injured mice exhibited less inflammation and necrosis and only closed partially (62%. Thermal injury resulted in marked increases in serum levels of IL-6, TNFα, KC (CXCL1, and MIP-2α (CXCL2. Interestingly, attenuated early ear wound healing in the thermally injured mouse resulted in incomplete tissue regeneration in addition to a marked inflammatory response, as evidenced by the histological appearance of the wound and increased transcription of potent inflammatory mediators. Conclusion These findings suggest that the

  20. LXW7 ameliorates focal cerebral ischemia injury and attenuates inflammatory responses in activated microglia in rats

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    Fang, T.; Zhou, D.; Lu, L.; Tong, X.; Wu, J.; Yi, L. [Department of Neurology, Shenzhen Hospital, Peking University, Shenzhen (China)

    2016-08-01

    Inflammation plays a pivotal role in ischemic stroke, when activated microglia release excessive pro-inflammatory mediators. The inhibition of integrin αvβ3 improves outcomes in rat focal cerebral ischemia models. However, the mechanisms by which microglia are neuroprotective remain unclear. This study evaluated whether post-ischemic treatment with another integrin αvβ3 inhibitor, the cyclic arginine-glycine-aspartic acid (RGD) peptide-cGRGDdvc (LXW7), alleviates cerebral ischemic injury. The anti-inflammatory effect of LXW7 in activated microglia within rat focal cerebral ischemia models was examined. A total of 108 Sprague-Dawley rats (250–280 g) were subjected to middle cerebral artery occlusion (MCAO). After 2 h, the rats were given an intravenous injection of LXW7 (100 μg/kg) or phosphate-buffered saline (PBS). Neurological scores, infarct volumes, brain water content (BWC) and histology alterations were determined. The expressions of pro-inflammatory cytokines [tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β)], and Iba1-positive activated microglia, within peri-ischemic brain tissue, were assessed with ELISA, western blot and immunofluorescence staining. Infarct volumes and BWC were significantly lower in LXW7-treated rats compared to those in the MCAO + PBS (control) group. The LXW7 treatment lowered the expression of pro-inflammatory cytokines. There was a reduction of Iba1-positive activated microglia, and the TNF-α and IL-1β expressions were attenuated. However, there was no difference in the Zea Longa scores between the ischemia and LXW7 groups. The results suggest that LXW7 protected against focal cerebral ischemia and attenuated inflammation in activated microglia. LXW7 may be neuroprotective during acute MCAO-induced brain damage and microglia-related neurodegenerative diseases.

  1. LXW7 ameliorates focal cerebral ischemia injury and attenuates inflammatory responses in activated microglia in rats

    International Nuclear Information System (INIS)

    Fang, T.; Zhou, D.; Lu, L.; Tong, X.; Wu, J.; Yi, L.

    2016-01-01

    Inflammation plays a pivotal role in ischemic stroke, when activated microglia release excessive pro-inflammatory mediators. The inhibition of integrin αvβ3 improves outcomes in rat focal cerebral ischemia models. However, the mechanisms by which microglia are neuroprotective remain unclear. This study evaluated whether post-ischemic treatment with another integrin αvβ3 inhibitor, the cyclic arginine-glycine-aspartic acid (RGD) peptide-cGRGDdvc (LXW7), alleviates cerebral ischemic injury. The anti-inflammatory effect of LXW7 in activated microglia within rat focal cerebral ischemia models was examined. A total of 108 Sprague-Dawley rats (250–280 g) were subjected to middle cerebral artery occlusion (MCAO). After 2 h, the rats were given an intravenous injection of LXW7 (100 μg/kg) or phosphate-buffered saline (PBS). Neurological scores, infarct volumes, brain water content (BWC) and histology alterations were determined. The expressions of pro-inflammatory cytokines [tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β)], and Iba1-positive activated microglia, within peri-ischemic brain tissue, were assessed with ELISA, western blot and immunofluorescence staining. Infarct volumes and BWC were significantly lower in LXW7-treated rats compared to those in the MCAO + PBS (control) group. The LXW7 treatment lowered the expression of pro-inflammatory cytokines. There was a reduction of Iba1-positive activated microglia, and the TNF-α and IL-1β expressions were attenuated. However, there was no difference in the Zea Longa scores between the ischemia and LXW7 groups. The results suggest that LXW7 protected against focal cerebral ischemia and attenuated inflammation in activated microglia. LXW7 may be neuroprotective during acute MCAO-induced brain damage and microglia-related neurodegenerative diseases

  2. Melatonin attenuates oxidative stress and modulates inflammatory response after experimental burn trauma

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    Minka Hristova

    2018-04-01

    Full Text Available Introduction. Thermal injury activates an inflammatory response. Melatonin possesses anti-oxidant and anti-inflammatory properties. The objective of the present work was to study melatonin effects on the inflammatory response under conditions of oxidative stress during the early stage of thermal injury. Materials and methods. We used 24 white male rats of Wistar breed, randomly divided into three experimental groups. Group one was the control, group two was inflicted with burn trauma, and group three was inflicted with burn trauma, with melatonin application following the thermal injury. Melatonin was applied twice in doses of 10 g/kg b.m. immediately after the burn trauma and again at 12 hours. Plasma levels of tumor necrosis-factor-α (TNF-α, a pro-inflammatory mediator, and of interleukin-10 (Il-10, an anti-inflammatory mediator, were examined and their ratio was calculated. The levels of malondialdehyde (MDA, an oxidative stress marker, were also estimated. Results. Thermal trauma significantly increased plasma TNF-α levels (ð<0.01 and TNF-α /IL10 ratio but did not change IL-10 ones. Plasma MDA concentrations were significantly elevated as well (ð<0.0001. Melatonin application significantly reduced TNF-α (ð<0.05, increased IL-10 (ð<0.05, down-regulated TNF-α/IL-10 ratio and changed MDA concentrations (ð<0.01. In conclusion, our results show that local alteration induces oxidative stress and inflammatory response with TNF-α /IL-10 disbalance. Melatonin modulates this response and attenuates oxidative stress in experimental burn injury.

  3. Microglial activation - tuning and pruning adult neurogenesis

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    Christine T eEkdahl

    2012-03-01

    Full Text Available Adult born neurons are encountering numerous choices during their development from neural stem cells to mature functionally integrated neurons in the brain. Microglia are part of the microenvironment within the neurogenic niches and possibly involved during the entire decision process. Mounting evidence suggest that microglia act as local equalizers capable of amplifying as well as filtering homeostatic signals. Depending on their state of activation, they may induce or facilitate different fundamental decisions in neurogenesis, such as proliferation or quiescence, cell survival or death, migration or establishment, growth or retraction of dendrites and axons, synaptic assembly or pruning, or tuning of synaptic transmission. Microglia are activated as a first line of defence against infections and participate in transforming the innate immunity into an adaptive immune response by recruiting systemic immune cells. So far, most studies have reported an acute decrease in the survival of new neurons following this classically activated microglial reaction. However, the long-term effects are more complex. In several neurodegenerative diseases the microglial activation is also evident, including a heterogeneous population of microglial phenotypes and a plethora of immune mediators, where the initiating agent may be protein deposits or cell debris. The transformation from a pro- to an anti-inflammatory cytokine profile and the de-activation of microglia is not clearly defined, or even dysregulated, and the adaptive response is often sparse. The diverse role of microglial activation in neurodegenerative diseases is reflected by the numerous studies reporting both beneficial and detrimental effects on the different steps of neurogenesis. This review will highlight the most recent findings on how microglial activation modulates adult neurogenesis, and specifically discuss the role of microglia in synaptic integration, currently a fast expanding research

  4. A synthetic NCAM-derived mimetic peptide, FGL, exerts anti-inflammatory properties via IGF-1 and interferon-gamma modulation

    DEFF Research Database (Denmark)

    Downer, Eric J; Cowley, Thelma R; Cox, Fionnuala

    2009-01-01

    Microglial cell activity increases in the rat hippocampus during normal brain aging. The neural cell adhesion molecule (NCAM)-derived mimetic peptide, FG loop (FGL), acts as an anti-inflammatory agent in the hippocampus of the aged rat, promoting CD200 ligand expression while attenuating glial cell...

  5. Curcumin Ameliorates the Reduction Effect of PGE2 on Fibrillar β-Amyloid Peptide (1-42)-Induced Microglial Phagocytosis through the Inhibition of EP2-PKA Signaling in N9 Microglial Cells

    Science.gov (United States)

    Yang, Ju; Shen, Ting-ting; Chen, Yi; Yang, Xue-Sen

    2016-01-01

    Inflammatory activation of microglia and β amyloid (Aβ) deposition are considered to work both independently and synergistically to contribute to the increased risk of Alzheimer’s disease (AD). Recent studies indicate that long-term use of phenolic compounds provides protection against AD, primarily due to their anti-inflammatory actions. We previously suggested that phenolic compound curcumin ameliorated phagocytosis possibly through its anti-inflammatory effects rather than direct regulation of phagocytic function in electromagnetic field-exposed N9 microglial cells (N9 cells). Here, we explored the prostaglandin-E2 (PGE2)-related signaling pathway that involved in curcumin-mediated phagocytosis in fibrillar β-amyloid peptide (1–42) (fAβ42)-stimulated N9 cells. Treatment with fAβ42 increased phagocytosis of fluorescent-labeled latex beads in N9 cells. This increase was attenuated in a dose-dependent manner by endogenous and exogenous PGE2, as well as a selective EP2 or protein kinase A (PKA) agonist, but not by an EP4 agonist. We also found that an antagonist of EP2, but not EP4, abolished the reduction effect of PGE2 on fAβ42-induced microglial phagocytosis. Additionally, the increased expression of endogenous PGE2, EP2, and cyclic adenosine monophosphate (AMP), and activation of vasodilator-stimulated phosphoprotein, cyclic AMP responsive element-binding protein, and PKA were depressed by curcumin administration. This reduction led to the amelioration of the phagocytic abilities of PGE2-stimulated N9 cells. Taken together, these data suggested that curcumin restored the attenuating effect of PGE2 on fAβ42-induced microglial phagocytosis via a signaling mechanism involving EP2 and PKA. Moreover, due to its immune modulatory effects, curcumin may be a promising pharmacological candidate for neurodegenerative diseases. PMID:26824354

  6. Agmatine attenuates intestinal ischemia and reperfusion injury by reducing oxidative stress and inflammatory reaction in rats.

    Science.gov (United States)

    Turan, Inci; Ozacmak, Hale Sayan; Ozacmak, V Haktan; Barut, Figen; Araslı, Mehmet

    2017-11-15

    Oxidative stress and inflammatory response are major factors causing several tissue injuries in intestinal ischemia and reperfusion (I/R). Agmatine has been reported to attenuate I/R injury of various organs. The present study aims to analyze the possible protective effects of agmatine on intestinal I/R injury in rats. Four groups were designed: sham control, agmatine-treated control, I/R control, and agmatine-treated I/R groups. IR injury of small intestine was induced by the occlusion of the superior mesenteric artery for half an hour to be followed by a 3-hour-long reperfusion. Agmatine (10mg/kg) was administered intraperitoneally before reperfusion period. After 180min of reperfusion period, the contractile responses to both carbachol and potassium chloride (KCl) were subsequently examined in an isolated-organ bath. Malondialdehyde (MDA), reduced glutathione (GSH), and the activity of myeloperoxidase (MPO) were measured in intestinal tissue. Plasma cytokine levels were determined. The expression of the intestinal inducible nitric oxide synthase (iNOS) was also assessed by immunohistochemistry. The treatment with agmatine appeared to be significantly effective in reducing the MDA content and MPO activity besides restoring the content of GSH. The treatment also attenuated the histological injury. The increases in the I/R induced expressions of iNOS, IFN-γ, and IL-1α were brought back to the sham control levels by the treatment as well. Our findings indicate that the agmatine pretreatment may ameliorate reperfusion induced injury in small intestine mainly due to reducing inflammatory response and oxidative stress. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. A novel inhibitor of active protein kinase G attenuates chronic inflammatory and osteoarthritic pain.

    Science.gov (United States)

    Sung, Ying-Ju; Sofoluke, Nelson; Nkamany, Mary; Deng, Shixian; Xie, Yuli; Greenwood, Jeremy; Farid, Ramy; Landry, Donald W; Ambron, Richard T

    2017-05-01

    Activating PKG-1α induces a long-term hyperexcitability (LTH) in nociceptive neurons. Since the LTH correlates directly with chronic pain in many animal models, we tested the hypothesis that inhibiting PKG-1α would attenuate LTH-mediated pain. We first synthesized and characterized compound N46 (N-((3R,4R)-4-(4-(2-fluoro-3-methoxy-6-propoxybenzoyl)benzamido)pyrrolidin-3-yl)-1H-indazole-5-carboxamide). N46 inhibits PKG-1α with an IC50 of 7.5 nmol, was highly selective when tested against a panel of 274 kinases, and tissue distribution studies indicate that it does not enter the CNS. To evaluate its antinociceptive potential, we used 2 animal models in which the pain involves both activated PKG-1α and LTH. Injecting complete Freund's adjuvant (CFA) into the rat hind paw causes a thermal hyperalgesia that was significantly attenuated 24 hours after a single intravenous injection of N46. Next, we used a rat model of osteoarthritic knee joint pain and found that a single intra-articular injection of N46 alleviated the pain 14 days after the pain was established and the relief lasted for 7 days. Thermal hyperalgesia and osteoarthritic pain are also associated with the activation of the capsaicin-activated transient receptor protein vanilloid-1 (TRPV1) channel. We show that capsaicin activates PKG-1α in nerves and that a subcutaneous delivery of N46 attenuated the mechanical and thermal hypersensitivity elicited by exposure to capsaicin. Thus, PKG-1α appears to be downstream of the transient receptor protein vanilloid-1. Our studies provide proof of concept in animal models that a PKG-1α antagonist has a powerful antinociceptive effect on persistent, already existing inflammatory pain. They further suggest that N46 is a valid chemotype for the further development of such antagonists.

  8. trans-Lycopene from tomato juice attenuates inflammatory biomarkers in human plasma samples: An intervention trial.

    Science.gov (United States)

    Colmán-Martínez, Mariel; Martínez-Huélamo, Miriam; Valderas-Martínez, Palmira; Arranz-Martínez, Sara; Almanza-Aguilera, Enrique; Corella, Dolores; Estruch, Ramón; Lamuela-Raventós, Rosa M

    2017-11-01

    The effect of carotenoids from tomato juice (TJ) on inflammatory biomarkers was evaluated by performing a 4-week dose-response nutritional trial in a population at high cardiovascular risk. An open, prospective, randomized, cross-over, and controlled clinical trial was carried out with 28 volunteers (mean age 69.7 ± 3.1 years; mean BMI 31.5 ± 3.6 kg/m 2 ) at high cardiovascular risk, which were assigned to consume daily for 4 weeks in random order: 200 mL (LD) or 400 mL (HD) of TJ, or water as a control (C), with a 21-day wash-out period between each intervention. Blood samples were collected at baseline (B) and after each intervention. Endpoints included significant changes in plasmatic carotenoids, and adhesion molecules ICAM-1, and VCAM-1, as well as a tendency to decrease the chemokine IL-8. Compared to C, concentration of ICAM-1, and VCAM-1 were significantly lower (p ˂ 0.001), after each TJ intervention. Decreases were correlated remarkably with the trans-lycopene, while the other carotenoids present in TJ have presented a minor association or no association with changes in these molecules. trans-Lycopene from TJ may attenuate the risk of cardiovascular disease by reducing the concentration of important inflammatory molecules related to atherosclerosis. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Dietary L-arginine supplementation attenuates lipopolysaccharide-induced inflammatory response in broiler chickens.

    Science.gov (United States)

    Tan, Jianzhuang; Liu, Shasha; Guo, Yuming; Applegate, Todd J; Eicher, Susan D

    2014-04-28

    In the present study, two experiments were conducted to investigate the effect of dietary L-arginine (Arg) supplementation on the inflammatory response and innate immunity of broiler chickens. Expt 1 was designed as a 2 × 3 factorial arrangement (n 8 cages/treatment; n 6 birds/cage) with three dietary Arg concentrations (1.05, 1.42 and 1.90%) and two immune treatments (injection of lipopolysaccharide (LPS) or saline) given at an interval of 48 h between 14 and 21 d of age. In Expt 2, correlation between dietary Arg concentration (0.99, 1.39, 1.76, 2.13 or 2.53%) and percentage of circulating B cells (percentage of circulating lymphocytes) was determined. In Expt 1, LPS injection decreased body-weight gain and feed intake and increased feed conversion ratio of the challenged broilers (14-21 d; Psupplementation linearly decreased the percentages of CD11+, CD14+ and B cells in the spleen (Psupplementation decreased (Psupplementation attenuated the overexpression of pro-inflammatory cytokines probably through the suppression of the TLR4 pathway and CD14+ cell percentage. Furthermore, excessive Arg supplementation (1.76%) suppressed the percentages of circulating and splenic B cells.

  10. Repeated Excessive Exercise Attenuates the Anti-Inflammatory Effects of Exercise in Older Men

    Directory of Open Access Journals (Sweden)

    Ronni E. Sahl

    2017-06-01

    increased insulin resistance as estimated by the Quicki Index.Conclusion: The regular prolonged exercise did not influence abdominal adipose tissue inflammation, but the higher plasma IL-6 concentration concurrent with a trend toward higher insulin resistance and decreased VO2peak implies that the excessive amount of exercise probably attenuated the possible potential anti-inflammatory effects of exercise.

  11. Retinal microglial activation and inflammation induced by amadori-glycated albumin in a rat model of diabetes.

    Science.gov (United States)

    Ibrahim, Ahmed S; El-Remessy, Azza B; Matragoon, Suraporn; Zhang, Wenbo; Patel, Yogin; Khan, Sohail; Al-Gayyar, Mohammed M; El-Shishtawy, Mamdouh M; Liou, Gregory I

    2011-04-01

    During diabetes, retinal microglial cells are activated to release inflammatory cytokines that initiate neuronal loss and blood-retinal barrier breakdown seen in diabetic retinopathy (DR). The mechanism by which diabetes activates microglia to release those inflammatory mediators is unclear and was therefore elucidated. Microglia activation was characterized in streptozocin-injected rats and in isolated microglial cells using immunofluorescence, enzyme-linked immunosorbent assay, RT-PCR, and Western blot analyses. In 8-week diabetic retina, phospho-extracellular signal-related kinase (ERK) and P38 mitogen-activated protein kinases were localized in microglia, but not in Mueller cells or astrocytes. At the same time, Amadori-glycated albumin (AGA)-like epitopes were featured in the regions of microglia distribution, implicating a pathogenic effect on microglial activation. To test this, diabetic rats were treated intravitreally with A717, a specific AGA-neutralizing antibody, or murine IgG. Relative to nondiabetic rats, diabetic rats (IgG-treated) manifested 3.9- and 7.9-fold increases in Iba-1 and tumor necrosis factor (TNF)-α mRNAs, respectively. Treatment of diabetic rats with A717 significantly attenuated overexpression of these mRNAs. Intravitreal injection of AGA per se in normal rats resulted in increases of Iba-1 expression and TNF-α release. Guided by these results, a cultured retinal microglia model was developed to study microglial response after AGA treatment and the mechanistic basis behind this response. The results showed that formation of reactive oxygen species and subsequent activation of ERK and P38, but not Jun NH2-terminal kinase, are molecular events underpinning retinal microglial TNF-α release during AGA treatment. These results provide new insights in understanding the pathogenesis of early DR, showing that the accumulated AGA within the diabetic retina elicits the microglial activation and secretion of TNF-α. Thus, intervention trials

  12. Betahistine attenuates murine collagen-induced arthritis by suppressing both inflammatory and Th17 cell responses.

    Science.gov (United States)

    Tang, Kuo-Tung; Chao, Ya-Hsuan; Chen, Der-Yuan; Lim, Yun-Ping; Chen, Yi-Ming; Li, Yi-Rong; Yang, Deng-Ho; Lin, Chi-Chen

    2016-10-01

    The objective of this study was to evaluate the potential therapeutic effects of betahistine dihydrochloride (betahistine) in a collagen-induced arthritis (CIA) mouse model. CIA was induced in DBA/1 male mice by primary immunization with 100μl of emulsion containing 2mg/ml chicken type II collagen (CII) mixed with complete Freund's adjuvant (CFA) in an 1:1 ratio, and booster immunization with 100μl of emulsion containing 2mg/ml CII mixed with incomplete Freund's adjuvant (IFA) in an 1:1 ratio. Immunization was performed subcutaneously at the base of the tail. After being boosted on day 21, betahistine (1 and 5mg/kg) was orally administered daily for 2weeks. The severity of CIA was determined by arthritic scores and assessment of histopathological joint destruction. Expression of cytokines in the paw and anti-CII antibodies in the serum was evaluated by ELISA. The proliferative response against CII in the lymph node cells was measured by (3)H-thymidine incorporation assay. The frequencies of different CII specific CD4(+) T cell subsets in the lymph node were determined by flow-cytometric analysis. Betahistine treatment attenuated the severity of arthritis and reduced the levels of pro-inflammatory cytokines, including TNF-α, IL-6, IL-23 and IL-17A, in the paw tissues of CIA mice. Lymph node cells from betahistine-treated mice showed a decrease in proliferation, as well as a lower frequency of Th17 cells. In vitro, betahistine suppressed CD4(+) T cell differentiation into Th17 cells. These results indicate that betahistine is effective in suppressing both inflammatory and Th17 responses in mouse CIA and that it may have therapeutic value as an adjunct treatment for rheumatoid arthritis. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Redox Control of Microglial Function: Molecular Mechanisms and Functional Significance

    Science.gov (United States)

    McBean, Gethin; Cindric, Marina; Egea, Javier; López, Manuela G.; Rada, Patricia; Zarkovic, Neven

    2014-01-01

    Abstract Neurodegenerative diseases are characterized by chronic microglial over-activation and oxidative stress. It is now beginning to be recognized that reactive oxygen species (ROS) produced by either microglia or the surrounding environment not only impact neurons but also modulate microglial activity. In this review, we first analyze the hallmarks of pro-inflammatory and anti-inflammatory phenotypes of microglia and their regulation by ROS. Then, we consider the production of reactive oxygen and nitrogen species by NADPH oxidases and nitric oxide synthases and the new findings that also indicate an essential role of glutathione (γ-glutamyl-l-cysteinylglycine) in redox homeostasis of microglia. The effect of oxidant modification of macromolecules on signaling is analyzed at the level of oxidized lipid by-products and sulfhydryl modification of microglial proteins. Redox signaling has a profound impact on two transcription factors that modulate microglial fate, nuclear factor kappa-light-chain-enhancer of activated B cells, and nuclear factor (erythroid-derived 2)-like 2, master regulators of the pro-inflammatory and antioxidant responses of microglia, respectively. The relevance of these proteins in the modulation of microglial activity and the interplay between them will be evaluated. Finally, the relevance of ROS in altering blood brain barrier permeability is discussed. Recent examples of the importance of these findings in the onset or progression of neurodegenerative diseases are also discussed. This review should provide a profound insight into the role of redox homeostasis in microglial activity and help in the identification of new promising targets to control neuroinflammation through redox control of the brain. Antioxid. Redox Signal. 21, 1766–1801. PMID:24597893

  14. Cannabidiol attenuates high glucose-induced endothelial cell inflammatory response and barrier disruption

    Science.gov (United States)

    Rajesh, Mohanraj; Mukhopadhyay, Partha; Bátkai, Sándor; Haskó, György; Liaudet, Lucas; Drel, Viktor R.; Obrosova, Irina G.; Pacher, Pál

    2008-01-01

    A nonpsychoactive cannabinoid cannabidiol (CBD) has been shown to exert potent anti-inflammatory and antioxidant effects and has recently been reported to lower the incidence of diabetes in nonobese diabetic mice and to preserve the blood-retinal barrier in experimental diabetes. In this study we have investigated the effects of CBD on high glucose (HG)-induced, mitochondrial superoxide generation, NF-κB activation, nitrotyrosine formation, inducible nitric oxide synthase (iNOS) and adhesion molecules ICAM-1 and VCAM-1 expression, monocyte-endothelial adhesion, transendothelial migration of monocytes, and disruption of endothelial barrier function in human coronary artery endothelial cells (HCAECs). HG markedly increased mitochondrial superoxide generation (measured by flow cytometry using MitoSOX), NF-κB activation, nitrotyrosine formation, upregulation of iNOS and adhesion molecules ICAM-1 and VCAM-1, transendothelial migration of monocytes, and monocyte-endothelial adhesion in HCAECs. HG also decreased endothelial barrier function measured by increased permeability and diminished expression of vascular endothelial cadherin in HCAECs. Remarkably, all the above mentioned effects of HG were attenuated by CBD pretreatment. Since a disruption of the endothelial function and integrity by HG is a crucial early event underlying the development of various diabetic complications, our results suggest that CBD, which has recently been approved for the treatment of inflammation, pain, and spasticity associated with multiple sclerosis in humans, may have significant therapeutic benefits against diabetic complications and atherosclerosis. PMID:17384130

  15. Simvastatin attenuates the cerebral vascular endothelial inflammatory response in a rat traumatic brain injury.

    Science.gov (United States)

    Wang, Kuo-Wei; Chen, Han-Jung; Lu, Kang; Liliang, Po-Chou; Liang, Cheng-Loong; Tsai, Yu-Duan; Cho, Chung-Lung

    2014-01-01

    Traumatic brain injury (TBI) leads to important and deleterious inflammation, as evidenced by edema, cytokine production, induction of nitric oxide synthase, and leukocyte infiltration. After TBI, the activation of cerebral vascular endothelial cells plays a crucial role in the pathogenesis of inflammation. In this study, we hypothesized that the activation of cerebral vascular endothelial cells plays a crucial role in the pathogenesis of inflammation and outcome after TBI. It may represent a key cellular target for statin therapy. In our study, cortical contusions were induced, and the effect of continuous treatment of simvastatin on behavior and inflammation in adult rats following experimental TBI was evaluated. The treatment group received 15 mg/kg of simvastatin daily for 3 days. Neurological function was assessed with the grip test. The results showed that the non-treatment control group had a significantly greater increase in ICAM-1 expression from pre-injury to the post-injury 72 h time point as compared to the expression in treatment group. The treatment group had better neurological function as evidenced in a grip test performed from baseline to 72 h. The analysis of a western blot test and pathology also demonstrated reduced ICAM-1 expression and a smaller area of damage and tissue loss. Our findings suggest that simvastatin could attenuate the activation of cerebral vascular endothelial inflammatory response and decrease the loss of neurological function and brain tissue.

  16. Licochalcone A Prevents the Loss of Dopaminergic Neurons by Inhibiting Microglial Activation in Lipopolysaccharide (LPS-Induced Parkinson’s Disease Models

    Directory of Open Access Journals (Sweden)

    Bingxu Huang

    2017-09-01

    Full Text Available The neuroprotective effects of Licochalcone A (Lico.A, a flavonoid isolated from the herb licorice, in Parkinson’s disease (PD have not been elucidated. The prominent pathological feature of PD is the loss of dopaminergic neurons. The crucial role of neuroinflammation induced by activated microglia in dopaminergic neurodegeneration has been validated. In this study, we explore the therapeutic effects of Lico.A in lipopolysaccharide (LPS-induced PD models in vivo and in vitro. We find that Lico.A significantly inhibits LPS-stimulated production of pro-inflammatory mediators and microglial activation by blocking the phosphorylation of extracellular signal-regulated kinase (ERK1/2 and nuclear factor κB (NF-κB p65 in BV-2 cells. In addition, through cultured primary mesencephalic neuron-glia cell experiments, we illustrate that Lico.A attenuates the decrease in [3H] dopamine (DA uptake and the loss of tyrosine hydroxylase-immunoreactive (TH-ir neurons in LPS-induced PD models in vitro. Furthermore, LPS intoxication in rats results in microglial activation, dopaminergic neurodegeneration and significant behavioral deficits in vivo. Lico.A treatment prevents microglial activation and reduction of dopaminergic neuron and ameliorates PD-like behavioral impairments. Thus, these results demonstrate for the first time that the neuroprotective effects of Lico.A are associated with microglia and anti-inflammatory effects in PD models.

  17. Oxidation of HMGB1 causes attenuation of its pro-inflammatory activity and occurs during liver ischemia and reperfusion.

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    Anding Liu

    Full Text Available High mobility group box 1 (HMGB1 is a nuclear transcription factor. Once HMGB1 is released by damaged cells or activated immune cells, it acts as danger molecule and triggers the inflammatory signaling cascade. Currently, evidence is accumulating that posttranslational modifications such as oxidation may modulate the pro-inflammatory potential of danger signals. We hypothesized that oxidation of HMGB1 may reduce its pro-inflammatory potential and could take place during prolonged ischemia and upon reperfusion.Liver grafts were cold preserved for 24 h and flushed with saline in hourly intervals to collect the effluent. Liver grafts, cold-preserved for 6 h, were transplanted into syngeneic recipients to obtain serum and liver samples 24 h after initiation of reperfusion. Addition of the effluent to a macrophage culture induced the synthesis of tumor necrosis factor-alpha (TNF-α and interleukin (IL-6. The stimulatory activity of graft effluent was reduced after depletion of HMGB1 via immunoprecipitation. Oxidation of the effluent HMGB1 using H(2O(2 attenuated its stimulatory activity as well. Liver transplantation of cold preserved grafts caused HMGB1 translocation and release as determined by immunohistochemistry and ELISA-assay, respectively. Using Western blot with non-reducing conditions revealed the presence of oxidized HMGB1 in liver samples obtained after 12 h and in effluent samples after 16 h of cold preservation as well as in liver and serum samples obtained 24 h after reperfusion.These observations confirm that post-translational oxidation of HMGB1 attenuates its pro-inflammatory activity. Oxidation of HMGB1 as induced during prolonged ischemia and by reoxygenation during reperfusion in vivo might also attenuate its pro-inflammatory activity. Our findings also call for future studies to investigate the mechanism of the inhibitory effect of oxidized HMGB1 on the pro-inflammatory potential.

  18. Inhibition of EGFR/MAPK signaling reduces microglial inflammatory response and the associated secondary damage in rats after spinal cord injury

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    Qu Wen-sheng

    2012-07-01

    Full Text Available Abstract Background Emerging evidence indicates that reactive microglia-initiated inflammatory responses are responsible for secondary damage after primary traumatic spinal cord injury (SCI; epidermal growth factor receptor (EGFR signaling may be involved in cell activation. In this report, we investigate the influence of EGFR signaling inhibition on microglia activation, proinflammatory cytokine production, and the neuronal microenvironment after SCI. Methods Lipopolysaccharide-treated primary microglia/BV2 line cells and SCI rats were used as model systems. Both C225 and AG1478 were used to inhibit EGFR signaling activation. Cell activation and EGFR phosphorylation were observed after fluorescent staining and western blot. Production of interleukin-1beta (IL-1β and tumor necrosis factor alpha (TNFα was tested by reverse transcription PCR and ELISA. Western blot was performed to semi-quantify the expression of EGFR/phospho-EGFR, and phosphorylation of Erk, JNK and p38 mitogen-activated protein kinases (MAPK. Wet-dry weight was compared to show tissue edema. Finally, axonal tracing and functional scoring were performed to show recovery of rats. Results EGFR phosphorylation was found to parallel microglia activation, while EGFR blockade inhibited activation-associated cell morphological changes and production of IL-1β and TNFα. EGFR blockade significantly downregulated the elevated MAPK activation after cell activation; selective MAPK inhibitors depressed production of cytokines to a certain degree, suggesting that MAPK mediates the depression of microglia activation brought about by EGFR inhibitors. Subsequently, seven-day continual infusion of C225 or AG1478 in rats: reduced the expression of phospho-EGFR, phosphorylation of Erk and p38 MAPK, and production of IL-1β and TNFα; lessened neuroinflammation-associated secondary damage, like microglia/astrocyte activation, tissue edema and glial scar/cavity formation; and enhanced axonal

  19. Pyrroloquinoline quinone (PQQ inhibits lipopolysaccharide induced inflammation in part via downregulated NF-κB and p38/JNK activation in microglial and attenuates microglia activation in lipopolysaccharide treatment mice.

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    Chongfei Yang

    Full Text Available Therapeutic strategies designed to inhibit the activation of microglia may lead to significant advancement in the treatment of most neurodegenerative diseases. Pyrroloquinoline quinone (PQQ is a naturally occurring redox cofactor that acts as an essential nutrient, antioxidant, and has been reported to exert potent immunosuppressive effects. In the present study, the anti-inflammatory effects of PQQ was investigated in LPS treated primary microglia cells. Our observations showed that pretreatment with PQQ significantly inhibited the production of NO and PGE2 and suppressed the expression of pro-inflammatory mediators such as iNOS, COX-2, TNF-a, IL-1b, IL-6, MCP-1 and MIP-1a in LPS treated primary microglia cells. The nuclear translocation of NF-κB and the phosphorylation level of p65, p38 and JNK MAP kinase pathways were also inhibited by PQQ in LPS stimulated primary microglia cells. Further a systemic LPS treatment acute inflammation murine brain model was used to study the suppressive effects of PQQ against neuroinflammation in vivo. Mice treated with PQQ demonstrated marked attenuation of neuroinflammation based on Western blotting and immunohistochemistry analysis of Iba1-against antibody in the brain tissue. Indicated that PQQ protected primary cortical neurons against microglia-mediated neurotoxicity. These results collectively suggested that PQQ might be a promising therapeutic agent for alleviating the progress of neurodegenerative diseases associated with microglia activation.

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

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    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.

  1. Attenuation of TRPV1 and TRPV4 Expression and Function in Mouse Inflammatory Pain Models Using Electroacupuncture

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    Wei-Hsin Chen

    2012-01-01

    Full Text Available Although pain is a major human affliction, our understanding of pain mechanisms is limited. TRPV1 (transient receptor potential vanilloid subtype 1 and TRPV4 are two crucial receptors involved in inflammatory pain, but their roles in EA- (electroacupuncture- mediated analgesia are unknown. We injected mice with carrageenan (carra or a complete Freund’s adjuvant (CFA to model inflammatory pain and investigated the analgesic effect of EA using animal behavior tests, immunostaining, Western blotting, and a whole-cell recording technique. The inflammatory pain model mice developed both mechanical and thermal hyperalgesia. Notably, EA at the ST36 acupoint reversed these phenomena, indicating its curative effect in inflammatory pain. The protein levels of TRPV1 and TRPV4 in DRG (dorsal root ganglion neurons were both increased at day 4 after the initiation of inflammatory pain and were attenuated by EA, as demonstrated by immunostaining and Western blot analysis. We verified DRG electrophysiological properties to confirm that EA ameliorated peripheral nerve hyperexcitation. Our results indicated that the AP (action potential threshold, rise time, and fall time, and the percentage and amplitude of TRPV1 and TRPV4 were altered by EA, indicating that EA has an antinociceptive role in inflammatory pain. Our results demonstrate a novel role for EA in regulating TRPV1 and TRPV4 protein expression and nerve excitation in mouse inflammatory pain models.

  2. Inducible nitric oxide synthase is key to peroxynitrite-mediated, LPS-induced protein radical formation in murine microglial BV2 cells.

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    Kumar, Ashutosh; Chen, Shih-Heng; Kadiiska, Maria B; Hong, Jau-Shyong; Zielonka, Jacek; Kalyanaraman, Balaraman; Mason, Ronald P

    2014-08-01

    Microglia are the resident immune cells in the brain. Microglial activation is characteristic of several inflammatory and neurodegenerative diseases including Alzheimer's disease, multiple sclerosis, and Parkinson's disease. Though lipopolysaccharide (LPS)-induced microglial activation in models of Parkinson's disease is well documented, the free radical-mediated protein radical formation and its underlying mechanism during LPS-induced microglial activation are not known. Here we have used immuno-spin trapping and RNA interference to investigate the role of inducible nitric oxide synthase (iNOS) in peroxynitrite-mediated protein radical formation in murine microglial BV2 cells treated with LPS. Treatment of BV2 cells with LPS resulted in morphological changes, induction of iNOS, and increased protein radical formation. Pretreatments with FeTPPS (a peroxynitrite decomposition catalyst), L-NAME (total NOS inhibitor), 1400W (iNOS inhibitor), and apocynin significantly attenuated LPS-induced protein radical formation and tyrosine nitration. Results obtained with coumarin-7-boronic acid, a highly specific probe for peroxynitrite detection, correlated with LPS-induced tyrosine nitration, which demonstrated involvement of peroxynitrite in protein radical formation. A similar degree of protection conferred by 1400W and L-NAME led us to conclude that only iNOS, and no other forms of NOS, is involved in LPS-induced peroxynitrite formation. Subsequently, siRNA for iNOS, the iNOS-specific inhibitor 1400W, the NF-κB inhibitor PDTC, and the p38 MAPK inhibitor SB202190 was used to inhibit iNOS directly or indirectly. Inhibition of iNOS precisely correlated with decreased protein radical formation in LPS-treated BV2 cells. The time course of protein radical formation also matched the time course of iNOS expression. Taken together, these results prove the role of iNOS in peroxynitrite-mediated protein radical formation in LPS-treated microglial BV2 cells. Copyright © 2014

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

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    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.

  4. Neuropeptides and Microglial Activation in Inflammation, Pain, and Neurodegenerative Diseases.

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    Carniglia, Lila; Ramírez, Delia; Durand, Daniela; Saba, Julieta; Turati, Juan; Caruso, Carla; Scimonelli, Teresa N; Lasaga, Mercedes

    2017-01-01

    Microglial cells are responsible for immune surveillance within the CNS. They respond to noxious stimuli by releasing inflammatory mediators and mounting an effective inflammatory response. This is followed by release of anti-inflammatory mediators and resolution of the inflammatory response. Alterations to this delicate process may lead to tissue damage, neuroinflammation, and neurodegeneration. Chronic pain, such as inflammatory or neuropathic pain, is accompanied by neuroimmune activation, and the role of glial cells in the initiation and maintenance of chronic pain has been the subject of increasing research over the last two decades. Neuropeptides are small amino acidic molecules with the ability to regulate neuronal activity and thereby affect various functions such as thermoregulation, reproductive behavior, food and water intake, and circadian rhythms. Neuropeptides can also affect inflammatory responses and pain sensitivity by modulating the activity of glial cells. The last decade has witnessed growing interest in the study of microglial activation and its modulation by neuropeptides in the hope of developing new therapeutics for treating neurodegenerative diseases and chronic pain. This review summarizes the current literature on the way in which several neuropeptides modulate microglial activity and response to tissue damage and how this modulation may affect pain sensitivity.

  5. Neuropeptides and Microglial Activation in Inflammation, Pain, and Neurodegenerative Diseases

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    Lila Carniglia

    2017-01-01

    Full Text Available Microglial cells are responsible for immune surveillance within the CNS. They respond to noxious stimuli by releasing inflammatory mediators and mounting an effective inflammatory response. This is followed by release of anti-inflammatory mediators and resolution of the inflammatory response. Alterations to this delicate process may lead to tissue damage, neuroinflammation, and neurodegeneration. Chronic pain, such as inflammatory or neuropathic pain, is accompanied by neuroimmune activation, and the role of glial cells in the initiation and maintenance of chronic pain has been the subject of increasing research over the last two decades. Neuropeptides are small amino acidic molecules with the ability to regulate neuronal activity and thereby affect various functions such as thermoregulation, reproductive behavior, food and water intake, and circadian rhythms. Neuropeptides can also affect inflammatory responses and pain sensitivity by modulating the activity of glial cells. The last decade has witnessed growing interest in the study of microglial activation and its modulation by neuropeptides in the hope of developing new therapeutics for treating neurodegenerative diseases and chronic pain. This review summarizes the current literature on the way in which several neuropeptides modulate microglial activity and response to tissue damage and how this modulation may affect pain sensitivity.

  6. Microglial Dysregulation in Psychiatric Disease

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    Luciana Romina Frick

    2013-01-01

    Full Text Available Microglia, the brain's resident immune cells, are phagocytes of the macrophage lineage that have a key role in responding to inflammation and immune challenge in the brain. More recently, they have been shown to have a number of important roles beyond immune surveillance and response, including synaptic pruning during development and the support of adult neurogenesis. Microglial abnormalities have been found in several neuropsychiatric conditions, though in most cases it remains unclear whether these are causative or are a reaction to some other underlying pathophysiology. Here we summarize postmortem, animal, neuroimaging, and other evidence for microglial pathology in major depression, schizophrenia, autism, obsessive-compulsive disorder, and Tourette syndrome. We identify gaps in the existing literature and important areas for future research. If microglial pathology proves to be an important causative factor in these or other neuropsychiatric diseases, modulators of microglial function may represent a novel therapeutic strategy.

  7. Microglial Priming and Alzheimer's Disease: A Possible Role for (Early) Immune Challenges and Epigenetics?

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    Hoeijmakers, Lianne; Heinen, Yvonne; van Dam, Anne-Marie; Lucassen, Paul J; Korosi, Aniko

    2016-01-01

    Neuroinflammation is thought to contribute to Alzheimer's disease (AD) pathogenesis that is, to a large extent, mediated by microglia. Given the tight interaction between the immune system and the brain, peripheral immune challenges can profoundly affect brain function. Indeed, both preclinical and clinical studies have indicated that an aberrant inflammatory response can elicit behavioral impairments and cognitive deficits, especially when the brain is in a vulnerable state, e.g., during early development, as a result of aging, or under disease conditions like AD. However, how exactly peripheral immune challenges affect brain function and whether this is mediated by aberrant microglial functioning remains largely elusive. In this review, we hypothesize that: (1) systemic immune challenges occurring during vulnerable periods of life can increase the propensity to induce later cognitive dysfunction and accelerate AD pathology; and (2) that "priming" of microglial cells is instrumental in mediating this vulnerability. We highlight how microglia can be primed by both neonatal infections as well as by aging, two periods of life during which microglial activity is known to be specifically upregulated. Lasting changes in (the ratios of) specific microglial phenotypes can result in an exaggerated pro-inflammatory cytokine response to subsequent inflammatory challenges. While the resulting changes in brain function are initially transient, a continued and/or excess release of such pro-inflammatory cytokines can activate various downstream cellular cascades known to be relevant for AD. Finally, we discuss microglial priming and the aberrant microglial response as potential target for treatment strategies for AD.

  8. Hypoxia attenuates inflammatory mediators production induced by Acanthamoeba via Toll-like receptor 4 signaling in human corneal epithelial cells

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    Pan, Hong [Department of Ophthalmology, Qilu Hospital, Shandong University, 107, Wenhua Xi Road, Jinan 250012 (China); The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Public Health, Qilu Hospital, Shandong University, 107, Wenhua Xi Road, Jinan 250012 (China); Wu, Xinyi, E-mail: xywu8868@163.com [Department of Ophthalmology, Qilu Hospital, Shandong University, 107, Wenhua Xi Road, Jinan 250012 (China)

    2012-04-13

    Highlights: Black-Right-Pointing-Pointer Hypoxia attenuates Acanthamoeba-induced the production of IL-8 and IFN-{beta}. Black-Right-Pointing-Pointer Hypoxia inhibits TLR4 expression in a time-dependent manner in HCECs. Black-Right-Pointing-Pointer Hypoxia inhibits Acanthamoeba-induced the activation of NF-{kappa}B and ERK1/2 in HCECs. Black-Right-Pointing-Pointer Hypoxia decreases Acanthamoeba-induced inflammatory response via TLR4 signaling. Black-Right-Pointing-Pointer LPS-induced the secretion of IL-6 and IL-8 is abated by hypoxia via TLR4 signaling. -- Abstract: Acanthamoeba keratitis (AK) is a vision-threatening corneal infection that is intimately associated with contact lens use which leads to hypoxic conditions on the corneal surface. However, the effect of hypoxia on the Acanthamoeba-induced host inflammatory response of corneal epithelial cells has not been studied. In the present study, we investigated the effect of hypoxia on the Acanthamoeba-induced production of inflammatory mediators interleukin-8 (IL-8) and interferon-{beta} (IFN-{beta}) in human corneal epithelial cells and then evaluated its effects on the Toll-like receptor 4 (TLR4) signaling, including TLR4 and myeloid differentiation primary response gene (88) (MyD88) expression as well as the activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-{kappa}B) and extracellular signal-regulated kinases 1/2 (ERK1/2). We then studied the effect of hypoxia on a TLR4-specific inflammatory response triggered by the TLR4 ligand lipopolysaccharide (LPS). Our data showed that hypoxia significantly decreased the production of IL-8 and IFN-{beta}. Furthermore, hypoxia attenuated Acanthamoeba-triggered TLR4 expression as well as the activation of NF-{kappa}B and ERK1/2, indicating that hypoxia abated Acanthamoeba-induced inflammatory responses by affecting TLR4 signaling. Hypoxia also inhibited LPS-induced IL-6 and IL-8 secretion, myeloid differentiation primary response gene (88

  9. Hypoxia attenuates inflammatory mediators production induced by Acanthamoeba via Toll-like receptor 4 signaling in human corneal epithelial cells

    International Nuclear Information System (INIS)

    Pan, Hong; Wu, Xinyi

    2012-01-01

    Highlights: ► Hypoxia attenuates Acanthamoeba-induced the production of IL-8 and IFN-β. ► Hypoxia inhibits TLR4 expression in a time-dependent manner in HCECs. ► Hypoxia inhibits Acanthamoeba-induced the activation of NF-κB and ERK1/2 in HCECs. ► Hypoxia decreases Acanthamoeba-induced inflammatory response via TLR4 signaling. ► LPS-induced the secretion of IL-6 and IL-8 is abated by hypoxia via TLR4 signaling. -- Abstract: Acanthamoeba keratitis (AK) is a vision-threatening corneal infection that is intimately associated with contact lens use which leads to hypoxic conditions on the corneal surface. However, the effect of hypoxia on the Acanthamoeba-induced host inflammatory response of corneal epithelial cells has not been studied. In the present study, we investigated the effect of hypoxia on the Acanthamoeba-induced production of inflammatory mediators interleukin-8 (IL-8) and interferon-β (IFN-β) in human corneal epithelial cells and then evaluated its effects on the Toll-like receptor 4 (TLR4) signaling, including TLR4 and myeloid differentiation primary response gene (88) (MyD88) expression as well as the activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and extracellular signal-regulated kinases 1/2 (ERK1/2). We then studied the effect of hypoxia on a TLR4-specific inflammatory response triggered by the TLR4 ligand lipopolysaccharide (LPS). Our data showed that hypoxia significantly decreased the production of IL-8 and IFN-β. Furthermore, hypoxia attenuated Acanthamoeba-triggered TLR4 expression as well as the activation of NF-κB and ERK1/2, indicating that hypoxia abated Acanthamoeba-induced inflammatory responses by affecting TLR4 signaling. Hypoxia also inhibited LPS-induced IL-6 and IL-8 secretion, myeloid differentiation primary response gene (88) MyD88 expression and NF-κB activation, confirming that hypoxia suppressed the LPS-induced inflammatory response by affecting TLR4 signaling. In conclusion

  10. Ginsenoside Rc from Korean Red Ginseng (Panax ginseng C.A. Meyer) Attenuates Inflammatory Symptoms of Gastritis, Hepatitis and Arthritis.

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    Yu, Tao; Rhee, Man Hee; Lee, Jongsung; Kim, Seung Hyung; Yang, Yanyan; Kim, Han Gyung; Kim, Yong; Kim, Chaekyun; Kwak, Yi-Seong; Kim, Jong-Hoon; Cho, Jae Youl

    2016-01-01

    Korean Red Ginseng (KRG) is an herbal medicine prescribed worldwide that is prepared from Panax ginseng C.A. Meyer (Araliaceae). Out of ginseng's various components, ginsenosides are regarded as the major ingredients, exhibiting anticancer and anti-inflammatory activities. Although recent studies have focused on understanding the anti-inflammatory activities of KRG, compounds that are major anti-inflammatory components, precisely how these can suppress various inflammatory processes has not been fully elucidated yet. In this study, we aimed to identify inhibitory saponins, to evaluate the in vivo efficacy of the saponins, and to understand the inhibitory mechanisms. To do this, we employed in vitro lipopolysaccharide-treated macrophages and in vivo inflammatory mouse conditions, such as collagen (type II)-induced arthritis (CIA), EtOH/HCl-induced gastritis, and lipopolysaccharide (LPS)/D-galactosamine (D-GalN)-triggered hepatitis. Molecular mechanisms were also verified by real-time PCR, immunoblotting analysis, and reporter gene assays. Out of all the ginsenosides, ginsenoside Rc (G-Rc) showed the highest inhibitory activity against the expression of tumor necrosis factor (TNF)-[Formula: see text], interleukin (IL)-1[Formula: see text], and interferons (IFNs). Similarly, this compound attenuated inflammatory symptoms in CIA, EtOH/HCl-mediated gastritis, and LPS/D-galactosamine (D-GalN)-triggered hepatitis without altering toxicological parameters, and without inducing gastric irritation. These anti-inflammatory effects were accompanied by the suppression of TNF-[Formula: see text] and IL-6 production and the induction of anti-inflammatory cytokine IL-10 in mice with CIA. G-Rc also attenuated the increased levels of luciferase activity by IRF-3 and AP-1 but not NF-[Formula: see text]B. In support of this phenomenon, G-Rc reduced TBK1, IRF-3, and ATF2 phosphorylation in the joint and liver tissues of mice with hepatitis. Therefore, our results strongly suggest that

  11. Microglial depletion alters the brain neuroimmune response to acute binge ethanol withdrawal.

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    Walter, T Jordan; Crews, Fulton T

    2017-04-20

    Recent studies have implicated microglia-the resident immune cells of the brain-in the pathophysiology of alcoholism. Indeed, post-mortem alcoholic brains show increased microglial markers and increased immune gene expression; however, the effects of ethanol on microglial functioning and how this impacts the brain remain unclear. In this present study, we investigate the effects of acute binge ethanol on microglia and how microglial depletion changes the brain neuroimmune response to acute binge ethanol withdrawal. C57BL/6J mice were treated intragastrically with acute binge ethanol for time course and dose-response studies. Cultured mouse BV2 microglia-like cells were treated with ethanol in vitro for time course studies. Mice were also administered the colony stimulating factor 1 receptor (CSF1R) inhibitor PLX5622 to deplete microglia from the brain. These mice were subsequently treated with acute binge ethanol and sacrificed during withdrawal. Brain and BV2 mRNA were isolated and assessed using RT-PCR to examine expression of microglial and neuroimmune genes. Acute binge ethanol biphasically changed microglial (e.g., Iba1, CD68) gene expression, with initial decreases during intoxication and subsequent increases during withdrawal. Acute ethanol withdrawal dose dependently increased neuroimmune gene (e.g., TNFα, Ccl2, IL-1ra, IL-4) expression beginning at high doses. BV2 cells showed biphasic changes in pro-inflammatory (e.g., TNFα, Ccl2) gene expression following ethanol treatment in vitro. Administration of PLX5622 depleted microglia from the brains of mice. Although some neuroimmune genes were reduced by microglial depletion, many others were unchanged. Microglial depletion blunted pro-inflammatory (e.g., TNFα, Ccl2) gene expression and enhanced anti-inflammatory (e.g., IL-1ra, IL-4) gene expression during acute binge ethanol withdrawal. These studies find acute binge ethanol withdrawal increases microglial and neuroimmune gene expression. Ethanol exposure

  12. Epigallocatechin-3-gallate attenuates lipopolysaccharide-induced mastitis in rats via suppressing MAPK mediated inflammatory responses and oxidative stress.

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    Chen, Jinglou; Xu, Jun; Li, Jingjing; Du, Lifen; Chen, Tao; Liu, Ping; Peng, Sisi; Wang, Mingwei; Song, Hongping

    2015-05-01

    Green tea (Camellia sinensis) is an extremely popular beverage worldwide. Epigallocatechin-3-gallate (EGCG) is one of the major catechins isolated from green tea and contributes to its beneficial therapeutic functions including antioxidant, anti-inflammatory and anti-cancer effects. However, the effect of EGCG on mastitis is not yet known. This study was to investigate the protective potential of EGCG against mastitis in rats. The rat mastitis model was induced by injecting lipopolysaccharide (LPS) into the duct of mammary gland. The mammary gland was collected after the experimental period. The levels of mammary oxidative stress and inflammatory responses were assessed by measuring the local activities of antioxidant enzymes and the levels of inflammatory cytokines. The mammary expressions of mitogen-activated protein kinases (MAPKs), nuclear factor κB-p65 (NFκB-p65) and hypoxia-inducible factor-1α (HIF-1α) were evaluated by western blot analysis. It was found that EGCG obviously normalized LPS-induced low activities of antioxidant enzymes as well as decreased the high levels of inflammatory cytokines. Additionally, EGCG inhibited the mammary over-expression of MAPKs, NFκB-p65 and HIF-1α. These results indicated that EGCG was able to attenuate LPS-induced mastitis in rats by suppressing MAPK related oxidative stress and inflammatory responses. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Anti-inflammatory effects of sargachromenol-rich ethanolic extract of Myagropsis myagroides on lipopolysaccharide-stimulated BV-2 cells

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    Kim, Sunghee; Lee, Min-Sup; Lee, Bonggi; Gwon, Wi-Gyeong; Joung, Eun-Ji; Yoon, Na-Young; Kim, Hyeung-Rak

    2014-01-01

    Background Excessive pro-inflammatory cytokine production from activated microglia contributes to neurodegenerative diseases, thus, microglial inactivation may delay the progress of neurodegeneration by attenuating the neuroinflammation. Among 5 selected brown algae, we found the highest antioxidant and anti-neuroinflammatory activities from Myagropsis myagroides ethanolic extract (MME) in lipopolysaccharide (LPS)-stimulated BV-2 cells. Methods The levels of nitric oxide (NO), prostaglandin E...

  14. Inhibition of soluble epoxide hydrolase attenuates high-fat-diet-induced hepatic steatosis by reduced systemic inflammatory status in mice.

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    Yan Liu

    Full Text Available Non-alcoholic fatty liver disease is associated with obesity and considered an inflammatory disease. Soluble epoxide hydrolase (sEH is a major enzyme hydrolyzing epoxyeicosatrienoic acids and attenuates their cardiovascular protective and anti-inflammatory effects. We examined whether sEH inhibition can protect against high-fat (HF-diet-induced fatty liver in mice and the underlying mechanism. Compared with wild-type littermates, sEH-null mice showed lower diet-induced lipid accumulation in liver, as seen by Oil-red O staining and triglycerides levels. We studied the effect of sEH inhibition on diet-induced fatty liver by feeding C57BL/6 mice an HF diet for 8 weeks (short-term or 16 weeks (long-term and administering t-AUCB, a selective sEH inhibitor. sEH inhibition had no effect on the HF-diet-increased body and adipose tissue weight or impaired glucose tolerance but alleviated the diet-induced hepatic steatosis. Adenovirus-mediated overexpression of sEH in liver increased the level of triglycerides in liver and the hepatic inflammatory response. Surprisingly, the induced expression of sEH in liver occurred only with the long-term but not short-term HF diet, which suggests a secondary effect of HF diet on regulating sEH expression. Furthermore, sEH inhibition attenuated the HF-diet-induced increase in plasma levels of proinflammatory cytokines and their mRNA upregulation in adipose tissue, which was accompanied by increased macrophage infiltration. Therefore, sEH inhibition could alleviate HF-diet-induced hepatic steatosis, which might involve its anti-inflammatory effect in adipose tissue and direct inhibition in liver. sEH may be a therapeutic target for HF-diet-induced hepatic steatosis in inhibiting systemic inflammation.

  15. The AMPAR Antagonist Perampanel Attenuates Traumatic Brain Injury Through Anti-Oxidative and Anti-Inflammatory Activity.

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    Chen, Tao; Dai, Shu-Hui; Jiang, Zhi-Quan; Luo, Peng; Jiang, Xiao-Fan; Fei, Zhou; Gui, Song-Bai; Qi, Yi-Long

    2017-01-01

    Perampanel is a novel α-amino-3-hydroxy-5-methyl-4-isoxazole propionate receptor (AMPAR) antagonist, approved in over 35 countries as an adjunctive therapy for the treatment of seizures. Recently, it was found to exert protective effects against ischemic neuronal injury in vitro. In the present study, we investigated the potential protective effects of perampanel in a traumatic brain injury (TBI) model in rats. Oral administration with perampanel at a dose of 5 mg/kg exerted no major organ-related toxicities. We found that perampanel significantly attenuated TBI-induced brain edema, brain contusion volume, and gross motor dysfunction. The results of Morris water maze test demonstrated that perampanel treatment also improved cognitive function after TBI. These neuroprotective effects were accompanied by reduced neuronal apoptosis, as evidenced by decreased TUNEL-positive cells in brain sections. Moreover, perampanel markedly inhibited lipid peroxidation and obviously preserved the endogenous antioxidant system after TBI. In addition, enzyme-linked immunosorbent assay (ELISA) was performed at 4 and 24 h after TBI to evaluate the expression of inflammatory cytokines. The results showed that perampanel suppressed the expression of pro-inflammatory cytokines TNF-α and IL-1β, whereas increased the levels of anti-inflammatory cytokines IL-10 and TGF-β1. These data show that the orally active AMPAR antagonist perampanel affords protection against TBI-induced neuronal damage and neurological dysfunction through anti-oxidative and anti-inflammatory activity.

  16. JMJD2A attenuation affects cell cycle and tumourigenic inflammatory gene regulation in lipopolysaccharide stimulated neuroectodermal stem cells

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    Das, Amitabh, E-mail: amitabhdas.kn@gmail.com [Department of Bionanotechnology, Hanyang University, Seoul 133-791 (Korea, Republic of); Chai, Jin Choul, E-mail: jincchai@gmail.com [Department of Molecular and Life Science, Hanyang University, 1271 Sa 3-dong, Ansan 426-791, Gyeonggi-do (Korea, Republic of); Jung, Kyoung Hwa, E-mail: khjung2@gmail.com [Department of Molecular and Life Science, Hanyang University, 1271 Sa 3-dong, Ansan 426-791, Gyeonggi-do (Korea, Republic of); Das, Nando Dulal, E-mail: nando.hu@gmail.com [Clinical Research Centre, Inha University School of Medicine, Incheon 400-711 (Korea, Republic of); Kang, Sung Chul, E-mail: gujiju11@gmail.com [Department of Molecular and Life Science, Hanyang University, 1271 Sa 3-dong, Ansan 426-791, Gyeonggi-do (Korea, Republic of); Lee, Young Seek, E-mail: yslee@hanyang.ac.kr [Department of Molecular and Life Science, Hanyang University, 1271 Sa 3-dong, Ansan 426-791, Gyeonggi-do (Korea, Republic of); Seo, Hyemyung, E-mail: hseo@hanyang.ac.kr [Department of Molecular and Life Science, Hanyang University, 1271 Sa 3-dong, Ansan 426-791, Gyeonggi-do (Korea, Republic of); Chai, Young Gyu, E-mail: ygchai@hanyang.ac.kr [Department of Bionanotechnology, Hanyang University, Seoul 133-791 (Korea, Republic of); Department of Molecular and Life Science, Hanyang University, 1271 Sa 3-dong, Ansan 426-791, Gyeonggi-do (Korea, Republic of)

    2014-11-01

    JMJD2A is a lysine trimethyl-specific histone demethylase that is highly expressed in a variety of tumours. The role of JMJD2A in tumour progression remains unclear. The objectives of this study were to identify JMJD2A-regulated genes and understand the function of JMJD2A in p53-null neuroectodermal stem cells (p53{sup −/−} NE-4Cs). We determined the effect of LPS as a model of inflammation in p53{sup −/−} NE-4Cs and investigated whether the epigenetic modifier JMJD2A alter the expression of tumourigenic inflammatory genes. Global gene expression was measured in JMJD2A knockdown (kd) p53{sup −/−} NE-4Cs and in LPS-stimulated JMJD2A-kd p53{sup −/−} NE-4C cells. JMJD2A attenuation significantly down-regulated genes were Cdca2, Ccnd2, Ccnd1, Crebbp, IL6rα, and Stat3 related with cell cycle, proliferation, and inflammatory-disease responses. Importantly, some tumour-suppressor genes including Dapk3, Timp2 and TFPI were significantly up-regulated but were not affected by silencing of the JMJD2B. Furthermore, we confirmed the attenuation of JMJD2A also down-regulated Cdca2, Ccnd2, Crebbp, and Rest in primary NSCs isolated from the forebrains of E15 embryos of C57/BL6J mice with effective p53 inhibitor pifithrin-α (PFT-α). Transcription factor (TF) motif analysis revealed known binding patterns for CDC5, MYC, and CREB, as well as three novel motifs in JMJD2A-regulated genes. IPA established molecular networks. The molecular network signatures and functional gene-expression profiling data from this study warrants further investigation as an effective therapeutic target, and studies to elucidate the molecular mechanism of JMJD2A-kd-dependent effects in neuroectodermal stem cells should be performed. - Highlights: • Significant up-regulation of epigenetic modifier JMJD2A mRNA upon LPS treatment. • Inhibition of JMJD2A attenuated key inflammatory and tumourigenic genes. • Establishing IPA based functional genomics in JMJD2A-attenuated p53{sup

  17. Dark chocolate attenuates intracellular pro-inflammatory reactivity to acute psychosocial stress in men: A randomized controlled trial.

    Science.gov (United States)

    Kuebler, Ulrike; Arpagaus, Angela; Meister, Rebecca E; von Känel, Roland; Huber, Susanne; Ehlert, Ulrike; Wirtz, Petra H

    2016-10-01

    Flavanol-rich dark chocolate consumption relates to lower risk of cardiovascular mortality, but underlying mechanisms are elusive. We investigated the effect of acute dark chocolate consumption on inflammatory measures before and after stress. Healthy men, aged 20-50years, were randomly assigned to a single intake of either 50g of flavanol-rich dark chocolate (n=31) or 50g of optically identical flavanol-free placebo-chocolate (n=34). Two hours after chocolate intake, both groups underwent the 15-min Trier Social Stress Test. We measured DNA-binding-activity of the pro-inflammatory transcription factor NF-κB (NF-κB-BA) in peripheral blood mononuclear cells, as well as plasma and whole blood mRNA levels of the pro-inflammatory cytokines IL-1β and IL-6, and the anti-inflammatory cytokine IL-10, prior to chocolate intake as well as before and several times after stress. We also repeatedly measured the flavanol epicatechin and the stress hormones epinephrine and cortisol in plasma and saliva, respectively. Compared to the placebo-chocolate-group, the dark-chocolate-group revealed a marginal increase in IL-10 mRNA prior to stress (p=0.065), and a significantly blunted stress reactivity of NF-κB-BA, IL-1β mRNA, and IL-6 mRNA (p's⩽0.036) with higher epicatechin levels relating to lower pro-inflammatory stress reactivity (p's⩽0.033). Stress hormone changes to stress were controlled. None of the other measures showed a significant chocolate effect (p's⩾0.19). Our findings indicate that acute flavanol-rich dark chocolate exerts anti-inflammatory effects both by increasing mRNA expression of the anti-inflammatory cytokine IL-10 and by attenuating the intracellular pro-inflammatory stress response. This mechanism may add to beneficial effects of dark chocolate on cardiovascular health. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Sirtuin inhibition attenuates the production of inflammatory cytokines in lipopolysaccharide-stimulated macrophages

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Claudia A. [Universite catholique de Louvain, Louvain Drug Research Institute (LDRI), Pharmaceutics and Drug Delivery Research Group, Brussels B-1200 (Belgium); Fievez, Laurence [University of Liege, GIGA-Research, Laboratory of Cellular and Molecular Immunology, Liege B-4000 (Belgium); Neyrinck, Audrey M.; Delzenne, Nathalie M. [Universite catholique de Louvain, LDRI, Metabolism and Nutrition Research Group, Brussels B-1200 (Belgium); Bureau, Fabrice [University of Liege, GIGA-Research, Laboratory of Cellular and Molecular Immunology, Liege B-4000 (Belgium); Vanbever, Rita, E-mail: rita.vanbever@uclouvain.be [Universite catholique de Louvain, Louvain Drug Research Institute (LDRI), Pharmaceutics and Drug Delivery Research Group, Brussels B-1200 (Belgium)

    2012-04-20

    Highlights: Black-Right-Pointing-Pointer Lipopolysaccharide-stimulated macrophages were treated with cambinol and sirtinol. Black-Right-Pointing-Pointer Cambinol and sirtinol decreased lipopolysaccharide-induced cytokines. Black-Right-Pointing-Pointer Cambinol decreased NF-{kappa}B activity but had no impact on p38 MAPK activation. Black-Right-Pointing-Pointer Sirtuins are an interesting target for the treatment of inflammatory diseases. -- Abstract: In several inflammatory conditions such as rheumatoid arthritis or sepsis, the regulatory mechanisms of inflammation are inefficient and the excessive inflammatory response leads to damage to the host. Sirtuins are class III histone deacetylases that modulate the activity of several transcription factors that are implicated in immune responses. In this study, we evaluated the impact of sirtuin inhibition on the activation of lipopolysaccharide (LPS)-stimulated J774 macrophages by assessing the production of inflammatory cytokines. The pharmacologic inhibition of sirtuins decreased the production of tumour necrosis factor-alpha (TNF-{alpha}) interleukin 6 (IL-6) and Rantes. The reduction of cytokine production was associated with decreased nuclear factor kappa B (NF-{kappa}B) activity and inhibitor kappa B alpha (I{kappa}B{alpha}) phosphorylation while no impact was observed on the phosphorylation status of p38 mitogen-activated kinase (p38 MAPK). This work shows that sirtuin pharmacologic inhibitors are a promising tool for the treatment of inflammatory conditions.

  19. Telmisartan attenuates colon inflammation, oxidative perturbations and apoptosis in a rat model of experimental inflammatory bowel disease.

    Directory of Open Access Journals (Sweden)

    Hany H Arab

    Full Text Available Accumulating evidence has indicated the implication of angiotensin II in the pathogenesis of inflammatory bowel diseases (IBD via its proinflammatory features. Telmisartan (TLM is an angiotensin II receptor antagonist with marked anti-inflammatory and antioxidant actions that mediated its cardio-, reno- and hepatoprotective actions. However, its impact on IBD has not been previously explored. Thus, we aimed to investigate the potential alleviating effects of TLM in tri-nitrobenezene sulphonic acid (TNBS-induced colitis in rats. Pretreatment with TLM (10 mg/kg p.o. attenuated the severity of colitis as evidenced by decrease of disease activity index (DAI, colon weight/length ratio, macroscopic damage, histopathological findings and leukocyte migration. TLM suppressed the inflammatory response via attenuation of tumor necrosis factor-α (TNF-α, prostaglandin E2 (PGE2 and myeloperoxidase (MPO activity as a marker of neutrophil infiltration besides restoration of interleukin-10 (IL-10. TLM also suppressed mRNA and protein expression of nuclear factor kappa B (NF-κB p65 and mRNA of cyclo-oxygenase-2 (COX-2 and inducible nitric oxide synthase (iNOS proinflammatory genes with concomitant upregulation of PPAR-γ. The alleviation of TLM to colon injury was also associated with inhibition of oxidative stress as evidenced by suppression of lipid peroxides and nitric oxide (NO besides boosting glutathione (GSH, total anti-oxidant capacity (TAC and the activities of superoxide dismutase (SOD and glutathione peroxidase (GPx. With respect to apoptosis, TLM downregulated the increased mRNA, protein expression and activity of caspase-3. It also suppressed the elevation of cytochrome c and Bax mRNA besides the upregulation of Bcl-2. Together, these findings highlight evidences for the beneficial effects of TLM in IBD which are mediated through modulation of colonic inflammation, oxidative stress and apoptosis.

  20. Maternal obesity attenuates predelivery inflammatory reaction in C57BL/6N mice.

    Science.gov (United States)

    Appel, Sarah; Schulze-Edinghausen, Merle; Kretschmer, Tobias; Storck, Sarah; Janoschek, Ruth; Bae-Gartz, Inga; Handwerk, Marion; Wohlfarth, Maria; Nüsken, Kai-Dietrich; Hucklenbruch-Rother, Eva; Heykants, Malte; Mahabir, Esther; Dötsch, Jörg

    2017-08-01

    Inflammation and oxidative stress are known to increase before labour. Whether gonadal white adipose tissue (gWAT) participates in this process and whether labour-related processes in placental and adipose tissue are altered in obese women is unknown. In our mouse model, lean mice display elevated placental inflammation and oxidative stress towards the end of pregnancy, accompanied by an increased expression of pro-inflammatory factors in gWAT. Obese mice also display elevated levels of pro-inflammatory factors and oxidative stress in placentas shortly before birth. However, placental infiltration with leukocytes and an increase in gWAT pro-inflammatory factor expression in obese dams are lacking. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Ischemic preconditioning attenuates remote pulmonary inflammatory infiltration of diabetic rats with an intestinal and hepatic ischemia-reperfusion injury

    Directory of Open Access Journals (Sweden)

    Farid José Thomaz Neto

    2013-03-01

    Full Text Available PURPOSE: To assess ischemic preconditioning (IPC effects in pulmonary lesion in intestinal and hepatic ischemia-reperfusion (IR injury models using diabetic rats. METHODS: Diabetes (DM was induced in 28 male Wistar rats by alloxan (42 mg/kg, IV. After 28 days, severe DM rats were submitted to intestinal or hepatic IR injury with or without IPC. Intestinal IR (30 min of mesenteric artery occlusion and 30 min of reperfusion; n=6 and IPC groups (10 min ischemia, 10 min reperfusion, followed by intestinal IR; n=6, and Hepatic IR (30 min of hepatic pedicle occlusion and 30 min of reperfusion; n=5 and IPC groups (10 min ischemia, 10 min reperfusion, followed by hepatic IR; n=5, were compared to DM rats group (n=6. Plasmatic lactate, glycemia were measured before and after IR injury. Histomorphology of lung was performed counting inflammatory cells. Data was expressed in mean± SE. P<0.05. RESULTS: Glycemia and lactate were similar among groups. IPC did not interfere in these parameters. On histological evaluation, IR increased inflammatory cells infiltration in pulmonary parenchyma compared to control in both IR injury models. IPC attenuated inflammatory infiltration in lungs. CONCLUSION: Ischemic preconditioning protects against remote ischemia-reperfusion injury in lung on intestinal or hepatic ischemia-reperfusion model with acute diabetes.

  2. Schinus terebinthifolius Raddi ( Aroeira) leaves oil attenuates inflammatory responses in cutaneous wound healing in mice 1.

    Science.gov (United States)

    Estevão, Lígia Reis Moura; Simões, Ricardo Santos; Cassini-Vieira, Puebla; Canesso, Maria Cecilia Campos; Barcelos, Lucíola da Silva; Rachid, Milene Alvarenga; Câmara, Cláudio Augusto Gomes da; Evêncio-Neto, Joaquim

    2017-09-01

    To investigated the inflammatory, angiogenic and fibrogenic activities of the Schinus terebinthifolius Raddi leaves oil (STRO) on wound healing. The excisional wound healing model was used to evaluate the effects of STRO. The mice were divided into two groups: Control, subjected to vehicle solution (ointment lanolin/vaseline base), or STRO- treated group, administered topically once a day for 3, 7 and 14 days post-excision. We evaluated the macroscopic wound closure rate; the inflammation was evaluated by leukocytes accumulation and cytokine levels in the wounds. The accumulation of neutrophil and macrophages in the wounds were determined by assaying myeloperoxidase and N-acetyl-β-D-glucosaminidase activities. The levels of TNF-α, CXCL-1 and CCL-2 in wound were evaluated by ELISA assay. Angiogenesis and collagen fibers deposition were evaluated histologically. We observed that macroscopic wound closure rate was improved in wounds from STRO-group than Control-group. The wounds treated with STRO promoted a reduction in leucocyte accumulation and in pro-inflammatory cytokine. Moreover, STRO treatment increased significantly the number of blood vessels and collagen fibers deposition, as compared to control group. Topical application of STRO display anti-inflammatory and angiogenic effects, as well as improvement in collagen replacement, suggesting a putative use of this herb for the development of phytomedicines to treat inflammatory diseases, including wound healing.

  3. Salsalate attenuates diet induced non-alcoholic steatohepatitis in mice by decreasing lipogenic and inflammatory processes

    NARCIS (Netherlands)

    Liang, W.; Verschuren, L.; Mulder, P.; Hoorn, J.W.A. van der; Verheij, J.; Dam, A.D. van; Boon, M.R.; Princen, H.M.G.; Havekes, L.M.; Kleemann, R.; Hoek, A.M. van den

    2015-01-01

    BACKGROUND AND PURPOSE: Salsalate (salicylsalicylic acid) is an anti-inflammatory drug that was recently found to exert beneficial metabolic effects on glucose and lipid metabolism. Although its utility in the prevention and management of a wide range of vascular disorders, including type 2 diabetes

  4. Dietary L-arginine supplementation attenuates lipopolysaccharide-induced inflammatory response in broiler chickens

    Science.gov (United States)

    Two experiments were conducted to investigate the effect of dietary L-arginine (Arg) supplementation on inflammatory response and innate immunity of broilers. Experiment 1 was designed as a 2 × 3 factorial arrangement (n = 8 cages/treatment; 6 birds/cage) with 3 dietary Arg concentrations (1.05, 1.4...

  5. Induction of MicroRNA-21 with Exogenous Hydrogen Sulfide Attenuates Myocardial Ischemic and Inflammatory Injury in Mice

    Science.gov (United States)

    Toldo, Stefano; Das, Anindita; Mezzaroma, Eleonora; Chau, Vinh Q.; Marchetti, Carlo; Durrant, David; Samidurai, Arun; Van Tassell, Benjamin W.; Yin, Chang; Ockaili, Ramzi A.; Vigneshwar, Navin; Mukhopadhyay, Nitai D.; Kukreja, Rakesh C.; Abbate, Antonio; Salloum, Fadi N.

    2014-01-01

    Background Maintaining physiological levels of hydrogen sulfide (H2S) during ischemia is necessary to limit injury to the heart. Due to the anti-inflammatory effects of H2S, we proposed that the H2S donor, Na2S, would attenuate myocardial injury through upregulation of ‘protective’ microRNA (miR)-21 and suppression of the inflammasome, a macromolecular structure that amplifies inflammation and mediates further injury. Methods and Results Na2S-induced miR-21 expression was measured by qPCR in adult primary rat cardiomyocytes and in the mouse heart. We measured inflammasome formation and activity in cardiomyocytes challenged with lipopolysaccharide (LPS) and adenosine-tri-phosphate (ATP) or simulated ischemia/reoxygenation; and in the heart following regional myocardial ischemia/reperfusion (I/R), in the presence or absence of Na2S. To assess the direct anti-inflammatory effects of H2S in vivo, we utilized a peritonitis model by way of intraperitoneal injection of zymosan A. Na2S attenuated inflammasome formation and activity - measured by counting cytoplasmic aggregates of the scaffold protein Apoptosis Speck-like protein containing a Caspase-recruitment domain (ASC; −57%) and caspase-1 activity (−50%) in isolated cardiomyocytes and in the mouse heart (all P<0.05). Na2S also inhibited apoptosis (−38%) and necrosis (−43%) in cardiomyocytes in vitro and reduced myocardial infarct size (−63%) following I/R injury in vivo (all P<0.05). These protective effects were absent in cells treated with antagomiR-21 and in miR-21 KO mice. Na2S also limited the severity of inflammasome-dependent inflammation in the model of peritonitis (P<0.05) in wild-type but not in miR-21 KO mice. Conclusions Na2S induces cardioprotective effects through miR-21-dependent attenuation of ischemic and inflammatory injury in cardiomyocytes. PMID:24825878

  6. Peritoneal administration of Met-RANTES attenuates inflammatory and nociceptive responses in a murine neuropathic pain model.

    Science.gov (United States)

    Liou, Jiin-Tarng; Mao, Chih-Chieh; Ching-Wah Sum, Daniel; Liu, Fu-Chao; Lai, Ying-Shu; Li, Jui-Chin; Day, Yuan-Ji

    2013-01-01

    The C-C motif chemokine ligand 5 (CCL5; also known as regulated on activation, normal T expressed and secreted, or RANTES) is a member of the CC family of chemokines that specifically attract and activate leukocytes to sites of inflammation. Although CCL5 has been implicated in the processing of pain, its detailed mechanisms of action are still unknown. In this study, we investigated the potential of the Met-RANTES, a selective CCL5 receptor antagonist, via peritoneal administration to modulate the recruitment of inflammatory cells in injured sites and attenuate nociceptive responses in a neuropathic pain model in mice. Nociceptive sensitization, immune cell infiltration, multiple cytokine secretion, and opioid peptide expression in damaged nerves were studied. Our results indicated that Met-RANTES-treated mice had less behavioral hypersensitivity after partial sciatic nerve ligation. Macrophage infiltration, pro-inflammatory cytokine (TNFα, IL-1β, IL-6, and IFNγ) protein secretion, and enkephalin, β-endorphin, and dynorphin mRNA expression in damaged nerves following partial sciatic nerve ligation were significantly decreased, and anti-inflammatory cytokine (IL-10) protein was significantly increased in Met-RANTES-treated mice. These results suggest that CCL5 is capable of regulating the microenvironment that controls behavioral hypersensitivity at the level of the peripheral injured site in a murine chronic neuropathic pain model. The present study identifies the potent pro-inflammatory potential of CCL5 and verifies the possible role of selective CCL5 receptor inhibitor in a murine neuropathic pain model. Copyright © 2013 American Pain Society. Published by Elsevier Inc. All rights reserved.

  7. Myeloid-specific Acat1 ablation attenuates inflammatory responses in macrophages, improves insulin sensitivity, and suppresses diet-induced obesity.

    Science.gov (United States)

    Huang, Li-Hao; Melton, Elaina M; Li, Haibo; Sohn, Paul; Jung, DaeYoung; Tsai, Ching-Yi; Ma, Tian; Sano, Hiroyuki; Ha, HyeKyung; Friedline, Randall H; Kim, Jason K; Usherwood, Edward; Chang, Catherine Cy; Chang, Ta-Yuan

    2018-03-13

    Macrophages are phagocytes that play important roles in health and diseases. Acyl-CoA:cholesterol acyltransferase 1 [ACAT1] converts cellular cholesterol to cholesteryl esters, and is expressed in many cell types. Unlike global Acat1 knockout [KO], myeloid-specific Acat1 KO [Acat1 -M/-M ] does not cause overt abnormalities in mice. Here we performed analyses in age and sex matched Acat1 -M/-M and wild-type mice on chow or Western diet, and discovered that Acat1 -M/-M mice exhibit resistance to Western diet-induced obesity. On both chow and Western diets, Acat1 -M/-M mice display decreased adipocyte size and increased insulin sensitivity. When.fed with Western diet, Acat1 -M/-M mice contain fewer infiltrating macrophages in white adipose tissue (WAT), with significantly diminished inflammatory phenotype. Without Acat1, the [Ly6C hi ] monocytes express reduced levels of integrin beta 1, which plays a key role in the interaction between monocytes and the inflamed endothelium. Adoptive transfer experiment showed that the appearance of leukocytes from Acat1 -M/-M mice to the inflamed WAT of WT mice is significantly diminished. Under Western diet, Acat1 -M/-M causes suppression of multiple pro-inflammatory genes in WAT. Cell culture experiments show that in Raw 264.7 macrophages, inhibiting ACAT1 with a small molecule ACAT1-specific inhibitor reduces inflammatory responses to lipopolysaccharide. We conclude that under Western diet, blocking ACAT1 in macrophages attenuates inflammation in WAT. Other results show that Acat1 -M/-M does not compromise anti-viral immune response. Our work reveals that blocking ACAT1 -M/-M suppresses diet-induced obesity in part by slowing down monocyte infiltration to WAT, as well as by reducing the inflammatory responses of adipose tissue macrophages.

  8. Blueberry polyphenols attenuate kainic acid-induced decrements in cognition and alter inflammatory gene expression in rat hippocampus

    Science.gov (United States)

    Shukitt-Hale, Barbara; Lau, Francis C.; Carey, Amanda N.; Galli, Rachel L.; Spangler, Edward L.; Ingram, Donald K.; Joseph, James A.

    2016-01-01

    Cognitive impairment in age-related neurodegenerative diseases such as Alzheimer's disease may be partly due to long-term exposure and increased susceptibility to inflammatory insults. In the current study, we investigated whether polyphenols in blueberries can reduce the deleterious effects of inflammation induced by central administration of kainic acid by altering the expression of genes associated with inflammation. To this end, 4-month-old male Fischer-344 (F344) rats were fed a control, 0.015% piroxicam (an NSAID) or 2% blueberry diet for 8 weeks before either Ringer's buffer or kainic acid was bilaterally micro-infused into the hippocampus. Two weeks later, following behavioral evaluation, the rats were killed and total RNA from the hippocampus was extracted and used in real-time quantitative RT-PCR (qRT-PCR) to analyze the expression of inflammation-related genes. Kainic acid had deleterious effects on cognitive behavior as kainic acid-injected rats on the control diet exhibited increased latencies to find a hidden platform in the Morris water maze compared to Ringer's buffer-injected rats and utilized non-spatial strategies during probe trials. The blueberry diet, and to a lesser degree the piroxicam diet, was able to improve cognitive performance. Immunohistochemical analyses of OX-6 expression revealed that kainic acid produced an inflammatory response by increasing the OX-6 positive areas in the hippocampus of kainic acid-injected rats. Kainic acid up-regulated the expression of the inflammatory cytokines IL-1β and TNF-α, the neurotrophic factor IGF-1, and the transcription factor NF-κB. Blueberry and piroxicam supplementations were found to attenuate the kainic acid-induced increase in the expression of IL-1β, TNF-α, and NF-κB, while only blueberry was able to augment the increased IGF-1 expression. These results indicate that blueberry polyphenols attenuate learning impairments following neurotoxic insult and exert anti-inflammatory actions

  9. Flavonoids of Polygonum hydropiper L. attenuates lipopolysaccharide-induced inflammatory injury via suppressing phosphorylation in MAPKs pathways.

    Science.gov (United States)

    Tao, Junyu; Wei, Yingyi; Hu, Tingjun

    2016-01-22

    Polygonum hydropiper L. is widely used as a traditional remedy for the treatment of dysentery, gastroenteritis. It has been used to relieve swelling and pain, dispel wind and remove dampness, eliminate abundant phlegm and inflammatory for a long time. Previous study showed that antioxidants especially flavonoids pretreatment alleviated sepsis-induced injury in vitro and in vivo. In the present study, the possible anti-inflammatory effect of flavonoids from normal butanol fraction of Polygonum hydropiper L. extract (FNP) against inflammation induced by lipopolysaccharide (LPS) was evaluated in vivo and in vitro. The content of total flavonoid of FNP was determined by the aluminum colorimetric method. The content of rutin, quercetin and quercitrin was determined by HPLC method. Mice received FNP orally 3 days before an intra-peritoneal (i.p.) injection of lipopolysaccharide (LPS). Total superoxidase dismutase (T-SOD), total antioxidant capacity (T-AOC), glutathione peroxidase (GSH-PX), glutathione (GSH), myeloperoxidase (MPO) and malondialdehyde (MDA) levels were measured. Tumor necrosis factor-α levels in serum and tissue was measured. mRNA expressions of pro-inflammatory cytokines in lung were assessed by Real-Time PCR. Histopathological changes were evaluated in lung, ileum and colon. We also investigated FNP on reactive oxygen species (ROS), nitric oxide (NO) and pro-inflammatory cytokines (TNF-α, IL-1β, IL-6 and IL-8) production, inducible nitric oxide synthase (iNOS), Cyclooxygenase-2 (COX-2) protein expression, phosphorylation of MAPKs and AMPK in LPS-stimulated RAW264.7 cells. FNP increased the levels of T-SOD, T-AOC, GSH-PX and GSH, decreased the levels of TNF-α, MPO and MDA, attenuate the histopathological lesion in LPS-stimulated mice. FNP inhibited production of inflammatory cytokines, ROS and NO, protein expressions of iNOS and COX-2, phosphorylation of ERK, JNK and c-JUN in MAPKs, promoted phosphorylation of AMPKα suppressed by LPS. These results

  10. MicroRNA-132 attenuates LPS-induced inflammatory injury by targeting TRAF6 in neuronal cell line HT-22.

    Science.gov (United States)

    Ji, Yang-Fei; Wang, Dan; Liu, Yan-Ru; Ma, Xing-Rong; Lu, Hong; Zhang, Bo-Ai

    2018-01-29

    Epilepsy is a common neurological disorder in the central nervous system. Inflammation disrupts the blood-brain barrier, which is responsible for maintaining brain homeostasis. This study was aimed to investigate the functional role of microRNA (miR)-132 in hippocampal HT-22 cells under lipopolysaccharide (LPS) stimulation. In vitro cell inflammatory model was constructed by LPS stimulation. Inflammatory cell injury was evaluated according to the alterations of cell viability, apoptosis and expression of inflammatory cytokines. Then, miR-132 level after LPS treatment was assessed. Subsequently, miR-132 was abnormally expressed after cell transfection and the effects of miR-132 on LPS-induced cell inflammatory injury as well as phosphorylated levels of key kinases in the NF-κB and MAPK kinase (MEK)/ERK pathways were determined. The target gene was virtually screened and verified, and whether miR-132 affected HT-22 cells under LPS stimulation through regulating the target gene was verified. The results showed that the level of miR-132 was down-regulated by LPS in HT-22 cells, and the LPS-induced inflammatory injury could be reduced by miR-132 overexpression. Then, the phosphorylated levels of kinases in the NF-κB and MEK/ERK pathways were inhibited by miR-132 overexpression. Necrosis factor receptor-associated factor 6 (TRAF6) was predicted and verified to be a target of miR-132. Moreover, the alterations induced by miR-132 overexpression in the LPS-treated HT-22 cells were abrogated by TRAF6 overexpression. Therefore, we drew the conclusion that LPS down-regulated miR-132 and miR-132 attenuated LPS-induced inflammatory cell injury by targeting TRAF6, along with the inhibition of the NF-κB and MEK/ERK pathways. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  11. Nutrition and exercise can attenuate inflammatory and psychobiological changes in hypoxia?

    Directory of Open Access Journals (Sweden)

    Aline Venticinque Caris

    2017-01-01

    Full Text Available Exposure to hypoxia causes damage in several physiological systems, whose tissues are dependent on the O2 supply. Recently, there has been growing attention on the immunosuppressive and inflammatory potential of the hypoxia, including stimulation, nuclear factor kappa B pathway in macrophages and Th2 response from lymphocytes. These changes may result in transient immunosuppression and happen at the same time to worsening of cognition and other psychobiological aspects. Furthermore, exercise and nutrition, especially glutamine supplementation may provide important role, not pharmacological partially reversing the effects of hypoxia. In fact, recent studies show that moderate exercise can improve cognition in people exposed to hypoxia while the exercise associated with glutamine supplementation can reverse the increase in inflammatory markers and the Th1/Th2 balance. This review aims to bring the light of the discussion about nonpharmacological ways to prevent the effects of hypoxia on the connection between the immune system and the central nervous system.

  12. Repeated Excessive Exercise Attenuates the Anti-Inflammatory Effects of Exercise in Older Men

    DEFF Research Database (Denmark)

    Sahl, Ronni E.; Andersen, Peter R.; Gronbaek, Katja

    2017-01-01

    Introduction/Purpose: A number of studies have investigated the effect of training with a moderate exercise dose (3–6 h/weekly) on the inflammatory profile in blood, and the data are inconsistent. Cross-sectional studies indicate a positive effect of physical activity level on inflammation levels...... and risk of metabolic disease. However, it is not clear whether this may be dose dependent and if very prolonged repeated exercise therefore may be beneficial for low-grade inflammation. Based on this we studied how excessive repeated prolonged exercise influenced low-grade inflammation and adipose tissue...... anti-inflammatory macrophage content in six older male recreationally trained cyclists. Low-grade inflammation and adipose tissue macrophage content were investigated in six older trained men (age: 61 ± 4 years; VO2peak: 48 ± 2 mL kg−1 min−1) following repeated prolonged exercise. Methods: Cycling...

  13. Schinus terebinthifolius Raddi ( Aroeira) leaves oil attenuates inflammatory responses in cutaneous wound healing in mice

    OpenAIRE

    Estevão, Lígia Reis Moura; Simões, Ricardo Santos; Cassini-Vieira, Puebla; Canesso, Maria Cecilia Campos; Barcelos, Lucíola da Silva; Rachid, Milene Alvarenga; Câmara, Cláudio Augusto Gomes da; Evêncio-Neto, Joaquim

    2017-01-01

    Abstract Purpose: To investigated the inflammatory, angiogenic and fibrogenic activities of the Schinus terebinthifolius Raddi leaves oil (STRO) on wound healing. Methods: The excisional wound healing model was used to evaluate the effects of STRO. The mice were divided into two groups: Control, subjected to vehicle solution (ointment lanolin/vaseline base), or STRO- treated group, administered topically once a day for 3, 7 and 14 days post-excision. We evaluated the macroscopic wound clo...

  14. Amitriptyline, clomipramine, and maprotiline attenuate the inflammatory response by inhibiting neutrophil migration and mast cell degranulation

    Directory of Open Access Journals (Sweden)

    José Alves Gurgel

    2013-12-01

    Full Text Available Objective: Despite the recognized anti-inflammatory potential of heterocyclic antidepressants, the mechanisms concerning their modulating effects are not completely known. Thus, we evaluated the anti-inflammatory effect of amitriptyline, clomipramine, and maprotiline and the possible modulating properties of these drugs on neutrophil migration and mast cell degranulation. Methods: The hind paw edema and air-pouch models of inflammation were used. Male Wistar rats were treated with saline, amitriptyline, clomipramine or maprotiline (10, 30, or 90 mg/kg, per os [p.o.] 1 h before the injection of carrageenan (300 μg/0.1 mL/paw or dextran (500 μg/0.1 mL/paw. Then, edema formation was measured hourly. Neutrophil migration to carrageenan (500 μg/pouch and N-formyl-methionyl-leucyl-phenylalanine (fMLP (10-6 M/mL/pouch was also investigated in 6-day-old air-pouch cavities. Compound 48/80-induced mast cell degranulation was assessed in the mesenteric tissues of antidepressant-treated rats. Results: All tested antidepressants prevented both carrageenan- and dextran-induced edema. The anti-inflammatory effect of these drugs partially depends on the modulation of neutrophil migration, since they significantly counteracted the chemotactic response of both carrageenan and fMLP (p < 0.01. Furthermore, amitriptyline, clomipramine and maprotiline inhibited compound 48/80-induced mast cell degranulation (p < 0.001. Conclusions: These results suggest an important anti-inflammatory role of heterocyclic antidepressants, which is dependent on the modulation of neutrophil migration and mast cell stabilization.

  15. Attenuated age-impact on systemic inflammatory markers in the presence of a metabolic burden.

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    Anuurad Erdembileg

    Full Text Available The overall burden of chronic disease, inflammation and cardiovascular risk increases with age. Whether the relationship between age and inflammation is impacted by presence of an adverse metabolic burden is not known.We determined inflammatory markers in humans (336 Caucasians and 224 African Americans and in mice, representing a spectrum of age, weight and metabolic burden.In humans, levels of inflammatory markers increased significantly with age in subjects without the metabolic syndrome, (P=0.009 and P=0.037 for C-reactive protein, P<0.001 and P=0.001 for fibrinogen, P<0.001 and P=0.005 for serum amyloid-A, for Caucasians and African Americans, respectively. In contrast, trend patterns of inflammatory markers did not change significantly with age in subjects with metabolic syndrome in either ethnic group, except for fibrinogen in Caucasians. A composite z-score for systemic inflammation increased significantly with age in subjects without metabolic syndrome (P=0.004 and P<0.006 for Caucasians and African Americans, respectively but not in subjects with metabolic syndrome (P=0.009 for difference in age trend between metabolic syndrome and non-metabolic syndrome. In contrast, no similar age trend was found in vascular inflammation. The findings in humans were paralleled by results in mice as serum amyloid-A levels increased across age (range 2-15 months, P<0.01 and were higher in ob/ob mice compared to control mice (P<0.001.Presence of a metabolic challenge in mice and humans influences levels of inflammatory markers over a wide age range. Our results underscore that already at a young age, presence of a metabolic burden enhances inflammation to a level that appears to be similar to that of decades older people without metabolic syndrome.

  16. Bensal HP Attenuates the Inflammatory Response in Hair Shaving Associated Dermatitis.

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    Ray, Anjana; Mordorski, Breanne; Landriscina, Angelo; Rosen, Jamie; Nosanchuk, Joshua; Friedman, Adam

    2016-07-01

    Shaving is an ubiquitous practice, and cutaneous irritation and inflammation are common sequelae, which may be worsened by underlying skin conditions or poor hair removal techniques. Moisturizing shaving creams and aftershaves are available to help maintain or restore the epidermal barrier; however, many continue to suffer from post-shave redness, itching, and pain. To reduce post-shave inflammation, some products have included botanical and other natural ingredients, which are often favored by consumers. We evaluated Bensal HP, an ointment containing 3% oak bark extract, 3% salicylic acid, and 6% benzoic acid, which has documented anti-inflammatory and antimicrobial properties, in a murine model of shave irritation to determine whether it would be useful in this clinical setting. Shaving dermatitis was simulated using a depilatory agent and electric clippers, and the shaved area was photographed and treated with Bensal HP daily for four days. Compared to untreated controls, mice treated with Bensal HP experienced a visible reduction in skin irritation and inflammation. These findings were mirrored on histology, as Bensal HP-treated areas demonstrated increased epidermal integrity and decreased dermal inflammatory infiltrate compared to untreated skin. Using immunohistochemistry, fewer neutrophils and macrophages were noted, and cytokine analysis also revealed decreased IL-6 in Bensal HP-treated skin at 24 and 96 hours after shaving. These results highlight the potential of Bensal HP as an anti-inflammatory treatment for shave irritation. Given the product's application against a variety of inflammatory and infectious skin disorders, its use against shave irritation may also improve comorbid skin conditions, such as pseudofolliculitis barbae. J Drugs Dermatol. 2016;15(7):836-840.

  17. Annatto carotenoids attenuate oxidative stress and inflammatory response after high-calorie meal in healthy subjects.

    Science.gov (United States)

    Roehrs, Miguel; Conte, Lisiane; da Silva, Dariane Trivisiol; Duarte, Thiago; Maurer, Luana Haselein; de Carvalho, José Antonio Mainardi; Moresco, Rafael Noal; Somacal, Sabrina; Emanuelli, Tatiana

    2017-10-01

    The aim of this study was to evaluate the effect of annatto carotenoids intake associated to a single high-calorie meal (high fat and high carbohydrate) in postprandial biochemical, inflammatory and oxidative stress markers. Twelve healthy subjects (6 men, 6 women) were included in this randomised, controlled crossover study. Baseline blood samples were collected from fasting subjects that immediately received high-calorie meal without carotenoid (placebo) or containing 1.2mg/kg bixin (BIX) or 0.06mg/kg norbixin (NBIX). Blood samples were taken 60, 120 and 240min after meal intake. NBIX intake did not affect biochemical blood markers but reduced the postprandial levels of inflammatory cytokines (IL-1, IL-6 and TNF-α) and lipid oxidation 60-120min after meal. BIX only partially prevented postprandial-induced lipid oxidation. Results indicate that the intake of NBIX may be an alternative to reduce the postprandial inflammatory and oxidative stress responses to high-calorie meals. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. CETP Lowers TLR4 Expression Which Attenuates the Inflammatory Response Induced by LPS and Polymicrobial Sepsis

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    Tatiana Martins Venancio

    2016-01-01

    Full Text Available Sepsis is a systemic inflammatory response to infection eliciting high mortality rate which is a serious health problem. Despite numerous studies seeking for therapeutic alternatives, the mechanisms involved in this disease remain elusive. In this study we evaluated the influence of cholesteryl ester transfer protein (CETP, a glycoprotein that promotes the transfer of lipids between lipoproteins, on the inflammatory response in mice. Human CETP transgenic mice were compared to control mice (wild type, WT after polymicrobial sepsis induced by cecal ligation and puncture (CLP, aiming at investigating their survival rate and inflammatory profiles. Macrophages from the peritoneal cavity were stimulated with LPS in the presence or absence of recombinant CETP for phenotypic and functional studies. In comparison to WT mice, CETP mice showed higher survival rate, lower IL-6 plasma concentration, and decreased liver toll-like receptor 4 (TLR4 and acyloxyacyl hydrolase (AOAH protein. Moreover, macrophages from WT mice to which recombinant human CETP was added decreased LPS uptake, TLR4 expression, NF-κB activation and IL-6 secretion. This raises the possibility for new therapeutic tools in sepsis while suggesting that lowering CETP by pharmacological inhibitors should be inconvenient in the context of sepsis and infectious diseases.

  19. Donepezil inhibits the amyloid-beta oligomer-induced microglial activation in vitro and in vivo.

    Science.gov (United States)

    Kim, Hyo Geun; Moon, Minho; Choi, Jin Gyu; Park, Gunhyuk; Kim, Ae-Jung; Hur, Jinyoung; Lee, Kyung-Tae; Oh, Myung Sook

    2014-01-01

    Recent studies on Alzheimer's disease (AD) have focused on soluble oligomeric forms of amyloid-beta (Aβ oligomer, AβO) that are directly associated with AD-related pathologies, such as cognitive decline, neurodegeneration, and neuroinflammation. Donepezil is a well-known anti-dementia agent that increases acetylcholine levels through inhibition of acetylcholinesterase. However, a growing body of experimental and clinical studies indicates that donepezil may also provide neuroprotective and disease-modifying effects in AD. Additionally, donepezil has recently been demonstrated to have anti-inflammatory effects against lipopolysaccharides and tau pathology. However, it remains unknown whether donepezil has anti-inflammatory effects against AβO in cultured microglial cells and the brain in animals. Further, the effects of donepezil against AβO-mediated neuronal death, astrogliosis, and memory impairment have also not yet been investigated. Thus, in the present study, we examined the anti-inflammatory effect of donepezil against AβO and its neuroinflammatory mechanisms. Donepezil significantly attenuated the release of inflammatory mediators (prostaglandin E2, interleukin-1 beta, tumor necrosis factor-α, and nitric oxide) from microglia. Donepezil also decreased AβO-induced up-regulation of inducible nitric oxide synthase and cyclooxygenase-2 protein and phosphorylation of p38 mitogen-activated protein kinase as well as translocation of nuclear factor-kappa B. We next showed that donepezil suppresses activated microglia-mediated toxicity in primary hippocampal cells using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. In intrahippocampal AβO-injected mice, donepezil significantly inhibited microgliosis and astrogliosis. Furthermore, behavioral tests revealed that donepezil (2 mg/kg/day, 5 days, p.o.) significantly ameliorated AβO-induced memory impairment. These results suggest that donepezil directly inhibits microglial activation

  20. Pyrrolidinedithiocarbamate attenuates bleomycin-induced pulmonary fibrosis in rats: Modulation of oxidative stress, fibrosis, and inflammatory parameters.

    Science.gov (United States)

    Zaafan, Mai A; Zaki, Hala F; El-Brairy, Amany I; Kenawy, Sanaa A

    The current study aimed to investigate the modulatory effects of pyrrolidinedithiocarbamate (PDTC; 100 mg/kg) on bleomycin-induced pulmonary fibrosis (5 mg/kg; intratracheal) in rats. Rats were randomly assigned to three groups: normal control, bleomycin control, and PDTC-treated groups. Lung injury was evaluated through histological examination, immunohistochemical detection of inducible nitric oxide synthase (iNOS) in lung tissue and evaluating the total and differential leucocytes count in bronchoalveolar lavage fluid. Lung tissue was used for biochemical assessment of lung content of hydroxyproline, transforming growth factor beta-1 (TGF-β1), tumor necrosis factor-alpha (TNF-α) as well as analysis of lipid peroxides, reduced glutathione (GSH), and total nitrite contents. PDTC attenuated bleomycin-induced pulmonary fibrosis as evidenced by histological observations, decreased iNOS expression and prevention of bleomycin-induced altered total and differential leukocytes count. Additionally, PDTC caused a significant decrease in lung contents of hydroxyproline, TGF-β1, TNF-α, lipid peroxides, and total nitrite coupled with increase in lung GSH content as compared to bleomycin control group. PDTC attenuated bleomycin-induced pulmonary fibrosis in rats via its anti-inflammatory, antioxidant, and antifibrotic activities.

  1. Spinal injection of docosahexaenoic acid attenuates carrageenan-induced inflammatory pain through inhibition of microglia-mediated neuroinflammation in the spinal cord.

    Science.gov (United States)

    Lu, Y; Zhao, L-X; Cao, D-L; Gao, Y-J

    2013-06-25

    Neuroinflammation in the spinal cord plays a critical role in the processing of inflammatory pain. Docosahexaenoic acid (DHA), a predominant omega-3 polyunsaturated fatty acid in the central nervous system, is known to modulate inflammatory responses in various neurodegenerative disorders. In this study, we investigated whether DHA could reduce inflammatory pain and inhibit neuroinflammation in the spinal cord following carrageenan injection in mice. Intrathecal (i.t.) injection of DHA at 15min before carrageenan injection blocked carrageenan-induced pain hypersensitivity for more than 6h. In addition, i.t. injection of DHA at 3h after carrageenan transiently reversed carrageenan-induced heat hyperalgesia and mechanical allodynia. Furthermore, DHA treatment reduced carrageenan-induced activation of microglia, phosphorylation of p38 mitogen-activated protein kinase (MAPK), and production of proinflammatory cytokines (tumor necrosisfactor-α - TNF-α and interleukin-1β - IL-1β) in the L4-5 spinal cord. In cultured microglial cells, DHA dose-dependently reduced lipopolysaccharide (LPS)-induced phosphorylation of p38, production of proinflammatory cytokines (TNF-α, IL-1β, IL-6) and chemokines (CCL2, CCL3 and CXCL10). p38 inhibitor SB203580 inhibited LPS-induced expression of proinflammatory cytokines and chemokines in a dose-dependent manner. Taken together, these results provide evidence that DHA has antinociceptive effect in inflammatory pain, which may be attributed to, at least partially, suppressing a microglia-mediated inflammatory response through inhibition of p38 MAPK activation. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

  2. Sulforaphane improves oxidative status without attenuating the inflammatory response or cardiac impairment induced by ischemia-reperfusion in rats.

    Science.gov (United States)

    Bonetto, Jéssica Hellen Poletto; Fernandes, Rafael Oliveira; Seolin, Bruna Gazzi de Lima; Müller, Dalvana Daneliza; Teixeira, Rayane Brinck; Araujo, Alex Sander; Vassallo, Dalton; Schenkel, Paulo Cavalheiro; Belló-Klein, Adriane

    2016-05-01

    Sulforaphane, a natural isothiocyanate, demonstrates cardioprotection associated with its capacity to stimulate endogenous antioxidants and to inhibit inflammation. The aim of this study was to investigate whether sulforaphane is capable of attenuating oxidative stress and inflammatory responses through the TLR4/MyD88/NFκB pathway, and thereby could modulate post-ischemic ventricular function in isolated rat hearts submitted to ischemia and reperfusion. Male Wistar rats received sulforaphane (10 mg·kg(-1)·day(-1)) or vehicle i.p. for 3 days. Global ischemia was performed using isolated hearts, 24 h after the last injection, by interruption of the perfusion flow. The protocol included a 20 min pre-ischemic period followed by 20 min of ischemia and a 20 min reperfusion. Although no changes in mechanical function were observed, sulforaphane induced a significant increase in superoxide dismutase and heme oxygenase-1 expression (both 66%) and significantly reduced reactive oxygen species levels (7%). No differences were observed for catalase and glutathione peroxidase expression or their activities, nor for thioredoxin reductase, glutaredoxin reductase and glutathione-S-transferase. No differences were found in lipid peroxidation or TLR4, MyD88, and NF-κB expression. In conclusion, although sulforaphane was able to stimulate endogenous antioxidants modestly, this result did not impact inflammatory signaling or cardiac function of hearts submitted to ischemia and reperfusion.

  3. Carrot juice ingestion attenuates high fructose-induced circulatory pro-inflammatory mediators in weanling Wistar rats.

    Science.gov (United States)

    Mahesh, Malleswarapu; Bharathi, Munugala; Raja Gopal Reddy, Mooli; Pappu, Pranati; Putcha, Uday Kumar; Vajreswari, Ayyalasomayajula; Jeyakumar, Shanmugam M

    2017-03-01

    Adipose tissue, an endocrine organ, plays a vital role not only in energy homeostasis, but also in the development and/or progression of various metabolic diseases, such as insulin resistance, type 2 diabetes and non-alcoholic fatty liver disease (NAFLD), via several factors and mechanisms, including inflammation. This study tested, whether carrot juice administration affected the adipose tissue development and its inflammatory status in a high fructose diet-induced rat model. For this purpose, male weanling Wistar rats were divided into four groups and fed either control or high fructose diet of AIN-93G composition with or without carrot juice ingestion for an 8 week period. Administration of carrot juice did not affect the adiposity and cell size of visceral fat depot; retroperitoneal white adipose tissue (RPWAT), which was corroborated with unaltered expression of genes involved in adipogenic and lipogenic pathways. However, it significantly reduced the high fructose diet-induced elevation of plasma free fatty acid (FFA) (P ≤ 0.05), macrophage chemoattractant protein 1 (MCP1) (P ≤ 0.01) and high sensitive C-reactive protein (hsCRP) (P ≤ 0.05) levels. Carrot juice administration attenuated the high fructose diet-induced elevation of levels of circulatory FFA and pro-inflammatory mediators; MCP1 and hsCRP without affecting the adiposity and cell size of visceral fat depot; RPWAT. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  4. α-Asarone attenuates microglia-mediated neuroinflammation by inhibiting NF kappa B activation and mitigates MPTP-induced behavioral deficits in a mouse model of Parkinson's disease.

    Science.gov (United States)

    Kim, Byung-Wook; Koppula, Sushruta; Kumar, Hemant; Park, Ju-Young; Kim, Il-Woung; More, Sandeep V; Kim, In-Su; Han, Sang-Don; Kim, Si-Kwan; Yoon, Sung-Hwa; Choi, Dong-Kug

    2015-10-01

    The selective loss of dopaminergic neurons in Parkinson's disease (PD) is associated with microglial activation. Therefore, the importance of early therapeutic intervention to inhibit microglial activation would be an effective strategy to alleviate the progression of PD. α-Asarone, an active compound found in Araceae and Annonaceae plant species has been used to improve various disease conditions including central nervous system disorders. In the present study the in vitro and in vivo therapeutic effects of α-asarone isolated from the rhizome of Acorus gramineus Solander was evaluated on microglia-mediated neuroinflammation and neuroprotection. Lipopolysaccharide (LPS)-stimulated BV-2 microglial cells were used to evaluate in vitro effects. 1-methyl-4 phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP)-induced mouse model of PD was developed to study the neuroprotective effects of α-asarone in vivo. The results indicated that α-asarone significantly attenuated the LPS-stimulated increase in neuroinflammatory responses and suppressed pro-inflammatory cytokine production in BV-2 cells. Mechanistic study revealed that α-asarone inhibited the LPS-stimulated activation via regulation of nuclear factor kappa-B by blocking degradation of inhibitor kappa B-alpha signaling in BV-2 microglial cells. In in vivo studies, MPTP intoxication to mice resulted in brain microglial activation and significant behavioral deficits. Prophylactic treatment with α-asarone suppressed microglial activation and attenuated PD-like behavioral impairments as assessed by the Y-maze and pole tests. Taken together, these data demonstrate that α-asarone is a promising neuroprotective agent that should be further evaluated and developed for future prevention and treatment of microglia-mediated neuroinflammatory conditions including PD. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Celastrol Attenuates Inflammatory and Neuropathic Pain Mediated by Cannabinoid Receptor Type 2

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    Longhe Yang

    2014-08-01

    Full Text Available Celastrol, a major active ingredient of Chinese herb Tripterygium wilfordii Hook. f. (thunder god vine, has exhibited a broad spectrum of pharmacological activities, including anti-inflammation, anti-cancer and immunosuppression. In the present study, we used animal models of inflammatory pain and neuropathic pain, generated by carrageenan injection and spared nerve injury (SNI, respectively, to evaluate the effect of celastrol and to address the mechanisms underlying pain processing. Intraperitoneal (i.p. injection of celastrol produced a dose-dependent inhibition of carrageenan-induced edema and allodynia. Real-time PCR analysis showed that celastrol (0.3 mg/kg, i.p. significantly reduced mRNA expressions of inflammatory cytokines, TNF-α, IL-6, IL-1β, in carrageenan-injected mice. In SNI mice, pain behavior studies showed that celastrol (1 mg/kg, i.p. effectively prevented the hypersensitivity of mechanical nociceptive response on the third day post-surgery and the seventh day post-surgery. Furthermore, the anti-hyperalgesic effects of celastrol in carrageenan-injected mice and SNI mice were reversed by SR144528 (1 mg/kg, i.p., a specific cannabinoid receptor-2 (CB2 receptor antagonist, but not by SR141716 (1 mg/kg, i.p., a specific cannabinoid receptor-1 (CB1 receptor antagonist. Taken together, our results demonstrate the analgesia effects of celastrol through CB2 signaling and propose the potential of exploiting celastrol as a novel candidate for pain relief.

  6. Methoxsalen supplementation attenuates bone loss and inflammatory response in ovariectomized mice.

    Science.gov (United States)

    Ham, Ju Ri; Choi, Ra-Yeong; Yee, Sung-Tae; Hwang, Yun-Ho; Kim, Myung-Joo; Lee, Mi-Kyung

    2017-12-25

    Methoxsalen (MTS) is a natural bioactive compound found in a variety of plants that has many known biofunctions; however, its effects on osteoporosis and related mechanisms are not clear. This study examined whether MTS exhibited preventive effects against postmenopausal osteoporosis. Female C3H/HeN mice were divided into four groups: Sham, ovariectomy (OVX), OVX with MTS (0.02% in diet), and OVX with estradiol (0.03 μg/day, s.c). After 6 weeks, MTS supplementation significantly increased femur bone mineral density and bone surface along with bone surface/total volume. MTS significantly elevated the levels of serum formation markers (estradiol, osteocalcin and bone-alkaline phosphatase) such as estradiol in OVX mice. Tartrate resistant acid phosphatase staining revealed that MTS suppressed osteoclast numbers and formation in femur tissues compared with the OVX group. Supplementation of MTS slightly up-regulated osteoblastogenesis-related genes (Runx-2, osterix, osteocalcin, and Alp) expression, whereas it significantly down-regulated inflammatory genes (Nfκb and Il6) expression in femur tissue compared with the OVX group. These results indicate that MTS supplementation effectively prevented OVX-induced osteoporosis via enhancement of bone formation and suppression of inflammatory response in OVX mice. Our study provides valid scientific information regarding the development and application of MTS as a food ingredient, a food supplement or an alternative agent for preventing postmenopausal osteoporosis. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Psoralidin suppresses osteoclastogenesis in BMMs and attenuates LPS-mediated osteolysis by inhibiting inflammatory cytokines.

    Science.gov (United States)

    Kong, Lingbo; Ma, Rui; Yang, Xiaobin; Zhu, Ziqi; Guo, Hua; He, Baorong; Wang, Biao; Hao, Dingjun

    2017-10-01

    Psoralidin is a metabolic product from the seed of psoraleacorylifolia, possessed anti-inflammatory and immunomodulatory effects. We speculated that psoralidin might impact osteoclastogenesis and bone loss. By using both in vitro and in vivo studies, we observed psoralidin strongly inhibited RANKL induced osteoclast formation during preosteoclast cultures, suggesting that it acts on osteoclast precursors to inhibit RANKL/RANK signaling. At the molecular level, by using MAPKs specific inhibitors (U-0126, SB-203580 and SP-600125) we demonstrated that psoralidin markedly abrogated the phosphorylation of p38, ERK, JNK. Moreover, the RANKL induced NF-κB/p65 phosphorylation and I-κB degradation were significantly inhibited by psoralidin. Further, psoralidin significantly suppressed osteoclastogenesis marker genes of TRAP, Cathepsin K and OSCAR. These were accompanied by the decreased expression of c-Fos and NFATc1 transcription factors. Consistent with in vitro results, our in vivo and serologic studies showed psoralidin inhibited lipopolysaccharide induced bone resorption by suppressing the inflammatory cytokines: TNF-α and IL-6 expression, as well as the ratio of RNAKL : OPG. These results collectively suggested that psoralidin could represent a novel therapeutic strategy for osteoclast-related disorders, such as rheumatoid arthritis and postmenopausal osteoporosis. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Apoptosis induction and attenuation of inflammatory gene expression in murine macrophages via multitherapeutic nanomembranes

    International Nuclear Information System (INIS)

    Pierstorff, Erik; Krucoff, Max; Ho, Dean

    2008-01-01

    The realization of optimized therapeutic delivery is impaired by the challenge of localized drug activity and by the dangers of systemic cytotoxicity which often contribute to patient treatment complications. Here we demonstrate the block copolymer-mediated deposition and release of multiple therapeutics which include an LXRα/β agonist 3-((4-methoxyphenyl)amino)-4-phenyl-1-(phenylmethyl)-1H-pyrrole-2,5-dione (LXRa) and doxorubicin hydrochloride (Dox) at the air-water interface via Langmuir-Blodgett deposition, as well as copolymer-mediated potent drug elution toward the Raw 264.7 murine macrophage cell line. The resultant copolymer-therapeutic hybrid serves as a localized platform that can be functionalized with virtually any drug due to the integrated hydrophilic and hydrophobic components of the polymer structure. In addition, the sequestering function of the copolymer to anchor the drugs to implant surfaces can enhance delivery specificity when compared to systemic drug administration. Confirmation of drug functionality was confirmed via suppression of the interleukin 6 (Il-6) and tumor necrosis factor alpha (TNFα) inflammatory cytokines (LXRa), as well as DNA fragmentation analysis (Dox). Furthermore, the fragmentation assays and gene expression analysis demonstrated the innate biocompatibility of the copolymeric material at the gene expression level via the confirmed absence of material-induced apoptosis and a lack of inflammatory gene expression. This modality enables layer-by-layer control of agonist and chemotherapeutic functionalization at the nanoscale for the localization of drug dosage, while simultaneously utilizing the copolymer platform as an anchoring mechanism for drug sequestering, all with an innate material thickness of 4 nm per layer, which is orders of magnitude thinner than existing commercial technologies. Furthermore, these studies comprehensively confirmed the potential translational applicability of copolymeric nanomaterials as

  9. Lactobacillus rhamnosus GG and Bifidobacterium longum attenuate lung injury and inflammatory response in experimental sepsis.

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    Ludmila Khailova

    Full Text Available Probiotic use to prevent nosocomial gastrointestinal and potentially respiratory tract infections in critical care has shown great promise in recent clinical trials of adult and pediatric patients. Despite well-documented benefits of probiotic use in intestinal disorders, the potential for probiotic treatment to reduce lung injury following infection and shock has not been well explored.Evaluate if Lactobacillus rhamnosus GG (LGG or Bifidobacterium longum (BL treatment in a weanling mouse model of cecal ligation and puncture (CLP peritonitis will protect against lung injury.3 week-old FVB/N mice were orally gavaged with 200 µl of either LGG, BL or sterile water (vehicle immediately prior to CLP. Mice were euthanized at 24 h. Lung injury was evaluated via histology and lung neutrophil infiltration was evaluated by myeloperoxidase (MPO staining. mRNA levels of IL-6, TNF-α, MyD88, TLR-4, TLR-2, NFΚB (p50/p105 and Cox-2 in the lung analyzed via real-time PCR. TNF-α and IL-6 in lung was analyzed via ELISA.LGG and BL treatment significantly improved lung injury following experimental infection and sepsis and lung neutrophil infiltration was significantly lower than in untreated septic mice. Lung mRNA and protein levels of IL-6 and TNF-α and gene expression of Cox-2 were also significantly reduced in mice receiving LGG or BL treatment. Gene expression of TLR-2, MyD88 and NFΚB (p50/p105 was significantly increased in septic mice compared to shams and decreased in the lung of mice receiving LGG or BL while TLR-4 levels remained unchanged.Treatment with LGG and BL can reduce lung injury following experimental infection and sepsis and is associated with reduced lung inflammatory cell infiltrate and decreased markers of lung inflammatory response. Probiotic therapy may be a promising intervention to improve clinical lung injury following systemic infection and sepsis.

  10. Electroacupuncture Attenuates CFA-induced Inflammatory Pain by suppressing Nav1.8 through S100B, TRPV1, Opioid, and Adenosine Pathways in Mice.

    Science.gov (United States)

    Liao, Hsien-Yin; Hsieh, Ching-Liang; Huang, Chun-Ping; Lin, Yi-Wen

    2017-02-13

    Pain is associated with several conditions, such as inflammation, that result from altered peripheral nerve properties. Electroacupuncture (EA) is a common Chinese clinical medical technology used for pain management. Using an inflammatory pain mouse model, we investigated the effects of EA on the regulation of neurons, microglia, and related molecules. Complete Freund's adjuvant (CFA) injections produced a significant mechanical and thermal hyperalgesia that was reversed by EA or a transient receptor potential V1 (TRPV1) gene deletion. The expression of the astrocytic marker glial fibrillary acidic protein (GFAP), the microglial marker Iba-1, S100B, receptor for advanced glycation end-products (RAGE), TRPV1, and other related molecules was dramatically increased in the dorsal root ganglion (DRG) and spinal cord dorsal horn (SCDH) of CFA-treated mice. This effect was reversed by EA and TRPV1 gene deletion. In addition, endomorphin (EM) and N 6 -cyclopentyladenosine (CPA) administration reliably reduced mechanical and thermal hyperalgesia, thereby suggesting the involvement of opioid and adenosine receptors. Furthermore, blocking of opioid and adenosine A1 receptors reversed the analgesic effects of EA. Our study illustrates the substantial therapeutic effects of EA against inflammatory pain and provides a novel and detailed mechanism underlying EA-mediated analgesia via neuronal and non-neuronal pathways.

  11. Angelica Sinensis attenuates inflammatory reaction in experimental rat models having spinal cord injury.

    Science.gov (United States)

    Xu, Jun; E, Xiao-Qiang; Liu, Hui-Yong; Tian, Jun; Yan, Jing-Long

    2015-01-01

    This study was aimed to evaluate the effect of Angelica Sinensis on experimental rat models in which spinal cord injury was induced by studying different factors. Different factors causing inflammation play a key role in pathophysiology of SCI. Here three groups of rats (n=15, each was used). These included a sham control group where only laminectomy was performed, SCI group where SCI was induced and AS/SCI group where although SCI was induced but Angelica Sinensis was also administered to study its effect and draw a comparison with control. The expression of I-kBα and NF-kB p65 was also studied using western blotting and after recording optical density (OD) values of western blots. MPO activity was used to measure the effect of 20 mg/kg Angelica Sinensis. The levels of proinflammatory cytokines TNF-α, IL-1β and IL-6 were also studied. As compared with SCI group and sham control it was observed that Angelica Sinensis significantly reduced the expression of I-kBα and NF-kB p65, (PSinensis in rat models can attenuate the secondary damage caused by SCI and thus help in controlling the pathology of SCI in rats.

  12. Astrocytic Orosomucoid-2 Modulates Microglial Activation and Neuroinflammation.

    Science.gov (United States)

    Jo, Myungjin; Kim, Jong-Heon; Song, Gyun Jee; Seo, Minchul; Hwang, Eun Mi; Suk, Kyoungho

    2017-03-15

    Orosomucoid (ORM) is an acute-phase protein that belongs to the immunocalin subfamily, a group of small-molecule-binding proteins with immunomodulatory functions. Little is known about the role of ORM proteins in the CNS. The aim of the present study was to investigate the brain expression of ORM and its role in neuroinflammation. Expression of Orm2, but not Orm1 or Orm3, was highly induced in the mouse brain after systemic injection of lipopolysaccharide (LPS). Plasma levels of ORM2 were also significantly higher in patients with cognitive impairment than in normal subjects. RT-PCR, Western blot, and immunofluorescence analyses revealed that astrocytes are the major cellular sources of ORM2 in the inflamed mouse brain. Recombinant ORM2 protein treatment decreased microglial production of proinflammatory mediators and reduced microglia-mediated neurotoxicity in vitro LPS-induced microglial activation, proinflammatory cytokines in hippocampus, and neuroinflammation-associated cognitive deficits also decreased as a result of intracerebroventricular injection of recombinant ORM2 protein in vivo Moreover, lentiviral shRNA-mediated Orm2 knockdown enhanced LPS-induced proinflammatory cytokine gene expression and microglial activation in the hippocampus. Mechanistically, ORM2 inhibited C-C chemokine ligand 4 (CCL4)-induced microglial migration and activation by blocking the interaction of CCL4 with C-C chemokine receptor type 5. Together, the results from our cultured glial cells, mouse neuroinflammation model, and patient studies suggest that ORM2 is a novel mediator of astrocyte-microglial interaction. We also report that ORM2 exerts anti-inflammatory effects by modulating microglial activation and migration during brain inflammation. ORM2 can be exploited therapeutically for the treatment of neuroinflammatory diseases. SIGNIFICANCE STATEMENT Neural cell interactions are important for brain physiology and pathology. Particularly, the interaction between non

  13. 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

  14. Resistance Training with Co-ingestion of Anti-inflammatory Drugs Attenuates Mitochondrial Function

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    Daniele A. Cardinale

    2017-12-01

    Full Text Available Aim: The current study aimed to examine the effects of resistance exercise with concomitant consumption of high vs. low daily doses of non-steroidal anti-inflammatory drugs (NSAIDs on mitochondrial oxidative phosphorylation in skeletal muscle. As a secondary aim, we compared the effects of eccentric overload with conventional training.Methods: Twenty participants were randomized to either a group taking high doses (3 × 400 mg/day of ibuprofen (IBU; 27 ± 5 year; n = 11 or a group ingesting a low dose (1 × 75 mg/day of acetylsalicylic acid (ASA; 26 ± 4 year; n = 9 during 8 weeks of supervised knee extensor resistance training. Each of the subject's legs were randomized to complete the training program using either a flywheel (FW device emphasizing eccentric overload, or a traditional weight stack machine (WS. Maximal mitochondrial oxidative phosphorylation (CI+IIP from permeabilized skeletal muscle bundles was assessed using high-resolution respirometry. Citrate synthase (CS activity was assessed using spectrophotometric techniques and mitochondrial protein content using western blotting.Results: After training, CI+IIP decreased (P < 0.05 in both IBU (23% and ASA (29% with no difference across medical treatments. Although CI+IIP decreased in both legs, the decrease was greater (interaction p = 0.015 in WS (33%, p = 0.001 compared with FW (19%, p = 0.078. CS activity increased (p = 0.027 with resistance training, with no interactions with medical treatment or training modality. Protein expression of ULK1 increased with training in both groups (p < 0.001. The increase in quadriceps muscle volume was not correlated with changes in CI+IIP (R = 0.16.Conclusion: These results suggest that 8 weeks of resistance training with co-ingestion of anti-inflammatory drugs reduces mitochondrial function but increases mitochondrial content. The observed changes were not affected by higher doses of NSAIDs consumption, suggesting that the resistance training

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

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    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.

  16. Curcumin attenuates collagen-induced inflammatory response through the "gut-brain axis".

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    Dou, Yannong; Luo, Jinque; Wu, Xin; Wei, Zhifeng; Tong, Bei; Yu, Juntao; Wang, Ting; Zhang, Xinyu; Yang, Yan; Yuan, Xusheng; Zhao, Peng; Xia, Yufeng; Hu, Huijuan; Dai, Yue

    2018-01-06

    Previous studies have demonstrated that oral administration of curcumin exhibited an anti-arthritic effect despite its poor bioavailability. The present study aimed to explore whether the gut-brain axis is involved in the therapeutic effect of curcumin. The collagen-induced arthritis (CIA) rat model was induced by immunization with an emulsion of collagen II and complete Freund's adjuvant. Sympathetic and parasympathetic tones were measured by electrocardiographic recordings. Unilateral cervical vagotomy (VGX) was performed before the induction of CIA. The ChAT, AChE activities, and serum cytokine levels were determined by ELISA. The expression of the high-affinity choline transporter 1 (CHT1), ChAT, and vesicular acetylcholine transporter (VAChT) were determined by real-time PCR and immunohistochemical staining. The neuronal excitability of the vagus nerve was determined by whole-cell patch clamp recording. Oral administration of curcumin restored the imbalance between the sympathetic and parasympathetic tones in CIA rats and increased ChAT activity and expression of ChAT and VAChT in the gut, brain, and synovium. Additionally, VGX eliminated the effects of curcumin on arthritis and ACh biosynthesis and transport. Electrophysiological data showed that curcumin markedly increased neuronal excitability of the vagus nerve. Furthermore, selective α7 nAChR antagonists abolished the effects of curcumin on CIA. Our results demonstrate that curcumin attenuates CIA through the "gut-brain axis" by modulating the function of the cholinergic system. These findings provide a novel approach for mechanistic studies of anti-arthritic compounds with low oral absorption and bioavailability.

  17. Glycyrrhiza uralensis flavonoids inhibit brain microglial cell TNF-α secretion, p-IκB expression, and increase brain-derived neurotropic factor (BDNF secretion

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    Sangita P. Patil

    2014-07-01

    Conclusion: ASHMI and its effective flavonoid, isoliquiritigenin, inhibited TNF-α production by LPS stimulated microglial cells and elevated BDNF levels, which may prove to have anti-CNS inflammatory and anti-anxiety effects.

  18. Disruption of δ-opioid receptor phosphorylation at threonine 161 attenuates morphine tolerance in rats with CFA-induced inflammatory hypersensitivity.

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    Chen, Hai-Jing; Xie, Wei-Yan; Hu, Fang; Zhang, Ying; Wang, Jun; Wang, Yun

    2012-04-01

    Our previous study identified Threonine 161 (Thr-161), located in the second intracellular loop of the δ-opioid receptor (DOR), as the only consensus phosphorylation site for cyclin-dependent kinase 5 (Cdk5). The aim of this study was to assess the function of DOR phosphorylation by Cdk5 in complete Freund's adjuvant (CFA)-induced inflammatory pain and morphine tolerance. Dorsal root ganglion (DRG) neurons of rats with CFA-induced inflammatory pain were acutely dissociated and the biotinylation method was used to explore the membrane localization of phosphorylated DOR at Thr-161 (pThr-161-DOR), and paw withdrawal latency was measured after intrathecal delivery of drugs or Tat-peptide, using a radiant heat stimulator in rats with CFA-induced inflammatory pain. Both the total amount and the surface localization of pThr-161-DOR were significantly enhanced in the ipsilateral DRG following CFA injection. Intrathecal delivery of the engineered Tat fusion-interefering peptide corresponding to the second intracellular loop of DOR (Tat-DOR-2L) increased inflammatory hypersensitivity, and inhibited DOR- but not µ-opioid receptor-mediated spinal analgesia in CFA-treated rats. However, intrathecal delivery of Tat-DOR-2L postponed morphine antinociceptive tolerance in rats with CFA-induced inflammatory pain. Phosphorylation of DOR at Thr-161 by Cdk5 attenuates hypersensitivity and potentiates morphine tolerance in rats with CFA-induced inflammatory pain, while disruption of the phosphorylation of DOR at Thr-161 attenuates morphine tolerance.

  19. High Omega-3 Polyunsaturated Fatty Acids in fat-1 Mice Reduce Inflammatory Pain.

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    Zhang, Enji; Kim, Jwa-Jin; Shin, Nara; Yin, Yuhua; Nan, Yongshan; Xu, Yinshi; Hong, Jinpyo; Hsu, Tzung Min; Chung, Woosuk; Ko, Youngkwon; Lee, Wonhyung; Lim, Kyu; Kim, Dong Woon; Lee, Sun Yeul

    2017-06-01

    Omega-3 and omega-6 polyunsaturated fatty acids (PUFAs), such as α-linolenic and linoleic acids, are essential fatty acids in mammals, because they cannot be synthesized de novo. However, fat-1 transgenic mice can synthesize omega-3 PUFAs from omega-6 PUFAs without dietary supplementation of omega-3, leading to abundant omega-3 PUFA accumulation in various tissues. In this study, we used fat-1 transgenic mice to investigate the role of omega-3 PUFAs in response to inflammatory pain. A high omega-3 PUFA tissue content attenuated formalin-induced pain sensitivity, microglial activation, inducible nitric oxide synthase expression, and the phosphorylation of NR2B, a subunit of the N-methyl-d-aspartate (NMDA) receptor. Our findings suggest that elevated omega-3 PUFA levels inhibit NMDA receptor activity in the spinal dorsal horn and modulate inflammatory pain transmission by regulating signal transmission at the spinal dorsal horn, leading to the attenuation of chemically induced inflammatory pain.

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

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    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.

  1. Dopamine attenuates the chemoattractant effect of interleukin-8: a novel role in the systemic inflammatory response syndrome.

    LENUS (Irish Health Repository)

    Sookhai, S

    2012-02-03

    Activated neutrophil (PMN) adherence to vascular endothelium comprises a key step for both transendothelial migration and initiation of potentially deleterious release of PMN products. The biogenic amine, dopamine (DA), has been used for several decades in patients to maintain hemodynamic stability. The effect of dopamine on PMN transendothelial migration and adhesion receptor expression and on the endothelial molecules, E-selectin and ICAM-1, was evaluated. PMN were isolated from healthy controls, stimulated with lipopolysaccharide (LPS), and tumor necrosis factor-alpha (TNF-alpha) and treated with dopamine. CD 11b and CD 18 PMN adhesion receptor expression were assessed flow cytometrically. In a separate experiment, the chemoattractant peptide, IL-8, was placed in the lower chamber of transwells, and PMN migration was assessed. Human umbilical vein endothelial cells (HUVEC) were stimulated with LPS\\/TNF-alpha and incubated with dopamine. ICAM-1 and E-selectin endothelial molecule expression were assessed flow cytometrically. There was a significant increase in transendothelial migration in stimulated PMN compared with normal PMN (40 vs. 14%, P < 0.001). In addition, PMN CD11b\\/CD18 was significantly upregulated in stimulated PMN compared with normal PMN (252.4\\/352.4 vs. 76.7\\/139.4, P < 0.001) as were endothelial E-selectin\\/ICAM-1 expression compared with normal EC (8.1\\/9 vs. 3.9\\/3.8, P < 0.05). After treatment with dopamine, PMN transmigration was significantly decreased compared with stimulated PMN (8% vs. 40%, P < 0.001). Furthermore, dopamine also attenuated PMN CD11b\\/CD18 and the endothelial molecules E-selectin and ICAM-1 compared with stimulated PMN\\/EC that were not treated dopamine (174\\/240 vs. 252\\/352, P < 0.05 and 4\\/4.4 vs. 8.1\\/9, P < 0.05. respectively). The chemoattractant effect of IL-8 was also attenuated. These results identify for the first time that dopamine attenuates the initial interaction between PMN and the endothelium

  2. 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

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    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.

  3. Repetitive Hyperbaric Oxygenation Attenuates Reactive Astrogliosis and Suppresses Expression of Inflammatory Mediators in the Rat Model of Brain Injury

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    Irena Lavrnja

    2015-01-01

    Full Text Available The exact mechanisms by which treatment with hyperbaric oxygen (HBOT exerts its beneficial effects on recovery after brain injury are still unrevealed. Therefore, in this study we investigated the influence of repetitive HBOT on the reactive astrogliosis and expression of mediators of inflammation after cortical stab injury (CSI. CSI was performed on male Wistar rats, divided into control, sham, and lesioned groups with appropriate HBO. The HBOT protocol was as follows: 10 minutes of slow compression, 2.5 atmospheres absolute (ATA for 60 minutes, and 10 minutes of slow decompression, once a day for 10 consecutive days. Data obtained using real-time polymerase chain reaction, Western blot, and immunohistochemical and immunofluorescence analyses revealed that repetitive HBOT applied after the CSI attenuates reactive astrogliosis and glial scarring, and reduces expression of GFAP (glial fibrillary acidic protein, vimentin, and ICAM-1 (intercellular adhesion molecule-1 both at gene and tissue levels. In addition, HBOT prevents expression of CD40 and its ligand CD40L on microglia, neutrophils, cortical neurons, and reactive astrocytes. Accordingly, repetitive HBOT, by prevention of glial scarring and limiting of expression of inflammatory mediators, supports formation of more permissive environment for repair and regeneration.

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

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    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.

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

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    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.

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

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    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.

  7. 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.

  8. Ulinastatin Protects Against LPS-Induced Acute Lung Injury by Attenuating TLR4/NF-κB Pathway Activation and Reducing Inflammatory Mediators.

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    Cao, Chao; Yin, Chengfen; Shou, Songtao; Wang, Jun; Yu, Lechang; Li, Xuening; Chai, Yanfen

    2018-01-10

    Acute lung injury (ALI) and its severe form, acute respiratory distress syndrome (ARDS), remain the leading causes of morbidity and mortality in intensive care units. Ulinastatin (UTI), a serine protease inhibitor, possesses anti-inflammatory properties and has been suggested to modulate lipopolysaccharide (LPS)-induced sepsis; thus, it is now widely used in the treatment of pancreatitis, sepsis, and septic shock. Toll-like receptor 4 (TLR4), an essential LPS signaling receptor, plays a critical role in the activation of innate immunity. The aim of this study was to investigate whether UTI alleviates ALI by attenuating TLR4 expression and to explore the underlying molecular mechanisms involved. Male C56BL/6 mice were administered UTI intravenously 1 h before and 6 h after exposure to LPS by intra-tracheal instillation. Human lung epithelial (BEAS-2B) cells were incubated with LPS in the presence or absence of UTI. An enzyme-linked immunosorbent assay was used to detect levels of inflammatory cytokines. Western blot analysis was performed to detect changes in TLR4 expression and nuclear factor-κB (NF-κB) activation. UTI significantly protected animals from LPS-induced ALI, decreasing the lung wet/dry weight ratio, ALI score, total cells, neutrophils, macrophages, myeloperoxidase activity, and malondialdehyde content, factors associated with lung histological damage. UTI treatment also markedly attenuated levels of TLR4 and other pro-inflammatory cytokines. Furthermore, UTI significantly attenuated LPS-induced increases in TLR4 protein expression and NF-κB activation in lung tissues. Similarly, UTI markedly attenuated TLR4 expression and NF-κB activation in LPS-stimulated BEAS-2B cells. These findings indicate that UTI ameliorates LPS-induced ALI by attenuating the TLR4/NF-κB pathway activation.

  9. Attenuation of mouse somatic and emotional inflammatory pain by hydralazine through scavenging acrolein and inhibiting neuronal activation.

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    Bai, Lu; Wang, Wen; Dong, Yu-Lin; Wang, Wei; Huang, Jing; Wang, Xue-Ying; Wang, Li-Ying; Li, Yun-Qing; Wu, Sheng-Xi

    2012-01-01

    Acrolein signaling is important during spinal cord injury; whether it is involved in somatic and emotional pain is not clear. Hydralazine is a potent antihypertensive drug and can scavenge acrolein efficiently. We hypothesized that hydralazine decreases spinal level acrolein and renders analgesic effects with some side effects, which was tested in the current study. Subcutaneous injection of formalin was used to induce somatic and emotional pain responses. The spinal neuronal activation (FOS expression) and acrolein expression were evaluated at 2 hours after subcutaneous formalin injection. The possible side effects of hydralazine on the murine central nervous system or cardiovascular system were evaluated at one hour after hydralazine injection with open field, elevated plus maze and rotarod tests, or telemetrical measurement of mean artery blood pressure and heart rate. The subcutanous injection of formalin into the left hind paw induced significant somatic and emotional pain responses, evaluated by the biphasic spontaneous flinch/licking of the injected hind paw and interphase ultrasonic vocalizations during the one hour window after formalin injection. The spinal acrolein level was significantly increased and neurons were activated at 2 hours after formalin injection. Intraperitoneal injection of hydralazine (at 0.1, 1 or 10 mg/kg of body weight) at one hour before formalin challenging dose-dependently attenuated the formalin induced pain responses with an analgesic 50% effect dose ranging from 0.2 to 1 mg/kg of body weight. Furthermore, the neuronal activation and elevated acrolein expression were dose-dependently inhibited by hydralazine pretreatment. The side effects of intraperitoneal hydralazine on locomotion, anxiety, and motor coordination at one hour after hydralazine administration had negative results. The main side effects of hydralazine were an insignificant decrease of blood pressure and a significant increase of heart rates at high dose (10 mg

  10. Ganoderma lucidum ethanol extract inhibits the inflammatory response by suppressing the NF-κB and toll-like receptor pathways in lipopolysaccharide-stimulated BV2 microglial cells.

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    Yoon, Hyun-Min; Jang, Kyung-Jun; Han, Min Seok; Jeong, Jin-Woo; Kim, Gi Young; Lee, Jai-Heon; Choi, Yung Hyun

    2013-03-01

    Ganoderma lucidum is a traditional Oriental medicine that has been widely used as a tonic to promote longevity and health in Korea and other Asian countries. Although a great deal of work has been carried out on the therapeutic potential of this mushroom, the pharmacological mechanisms of its anti-inflammatory actions remain unclear. In this study, we evaluated the inhibitory effects of G. lucidum ethanol extract (EGL) on the production of inflammatory mediators and cytokines in lipopolysaccharide (LPS)-stimulated murine BV2 microglia. We also investigated the effects of EGL on the LPS-induced activation of nuclear factor kappaB (NF-κB) and upregulation of toll-like receptor 4 (TLR4) and myeloid differentiation factor 88 (MyD88). Elevated levels of nitric oxide (NO), prostaglandin E(2) (PGE(2)) and pro-inflammatory cytokine production were detected in BV2 microglia following LPS stimulation. We identifed that EGL significantly inhibits the excessive production of NO, PGE(2) and pro-inflammatory cytokines, including interleukin (IL)-1β and tumor necrosis factor-α in a concentration-dependent manner without causing cytotoxicity. In addition, EGL suppressed NF-κB translocation and transcriptional activity by blocking IκB degradation and inhibiting TLR4 and MyD88 expression in LPS-stimulated BV2 cells. Our results indicate that the inhibitory effects of EGL on LPS-stimulated inflammatory responses in BV2 microglia are associated with the suppression of the NF-κB and TLR signaling pathways. Therefore, EGL may be useful in the treatment of neurodegenerative diseases by inhibiting inflammatory mediator responses in activated microglia.

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

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    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.

  12. Donepezil, an acetylcholinesterase inhibitor, attenuates LPS-induced inflammatory response in murine macrophage cell line RAW 264.7 through inhibition of nuclear factor kappa B translocation.

    Science.gov (United States)

    Arikawa, Mikihiko; Kakinuma, Yoshihiko; Noguchi, Tatsuya; Todaka, Hiroshi; Sato, Takayuki

    2016-10-15

    We have previously demonstrated that the pharmacotherapy with donepezil, an acetylcholinesterase inhibitor, suppresses cardiac remodeling in a mouse model of ischemic heart failure after myocardial infarction (MI). However, the precise mechanisms of the cardioprotective effect of donepezil have not been completely delineated. Because post-ischemic inflammation is a pathological key event in the cardiac remodeling process following MI, we investigated the hypothesis that donepezil acts as an inhibitor of inflammatory mediators. RAW 264.7 murine macrophage cells were pretreated with donepezil (100µM) prior to a pro-inflammatory stimulation by administration of lipopolysaccharide (LPS, 10ng/ml). Donepezil significantly reduced intra- and extracellular levels of various kinds of inflammatory mediators such as TNF-α, IL-1β, IL-2, IL-6 and IL-18 after the LPS stimulation, and attenuated LPS-induced nuclear translocation of nuclear factor-kappa B (NF-κB). These results indicate that donepezil possesses an anti-inflammatory property. However, the inhibitory effect of donepezil on the macrophage inflammatory responses was never reproduced by ACh, nor was disrupted by ACh receptor blockers. Moreover, other kinds of acetylcholinesterase inhibitors failed to inhibit the inflammatory responses in LPS-stimulated macrophage cells. These results suggest that a cholinergic anti-inflammatory pathway would not be involved in the anti-inflammatory effect of donepezil and that the specific characteristics of donepezil in suppressing the LPS-induced cytokine release and the NF-κB activation would be independent of its acetylcholinesterase inhibition. The present study showed that donepezil exerts an anti-inflammatory effect independently of acetylcholinesterase inhibitory action, thereby donepezil may contribute to cardioprotection during cardiac remodeling process in an ischemic heart failure after MI. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Quercetin inhibits expression of inflammatory cytokines through attenuation of NF-kappaB and p38 MAPK in HMC-1 human mast cell line.

    Science.gov (United States)

    Min, Y-D; Choi, C-H; Bark, H; Son, H-Y; Park, H-H; Lee, S; Park, J-W; Park, E-K; Shin, H-I; Kim, S-H

    2007-05-01

    Mast cell-mediated allergic inflammation is involved in many diseases such as asthma, sinusitis, and rheumatoid arthritis. Mast cells induce production of pro-inflammatory cytokines with immune regulatory properties. We investigated the effect of quercetin on the expression of pro-inflammatory cytokines in human mast cell line, HMC-1. HMC-1 cells were stimulated with phorbol 12-myristate 13-acetate (PMA) and calcium ionophore A23187 (PMACI). Quercetin decreased the gene expression and production of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, IL-6, and IL-8 in PMACI-stimulated HMC-1 cells. Quercetin attenuated PMACI-induced activation of NF-kappaB and p38 mitogen-activated protein kinase. Our study provides evidence that quercetin may suitable for the treatment of mast cell-derived allergic inflammatory diseases.

  14. 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

  15. Attenuation of meal-induced inflammatory and thrombotic responses in overweight men and women after 6-week daily strawberry (Fragaria) intake. A randomized placebo-controlled trial.

    Science.gov (United States)

    Ellis, Collin L; Edirisinghe, Indika; Kappagoda, Tissa; Burton-Freeman, Britt

    2011-01-01

    A pro-thrombotic, pro-inflammatory diet can play a causative role in atherosclerotic-cardiovascular diseases. Dietary intervention studies provide insight into their pathophysiological manifestations and opportunities for prevention and management. We previously showed in an acute-meal setting that a beverage containing polyphenolic- and antioxidant-rich strawberry (Fragaria) vs placebo attenuated postprandial (fed-state) increases in biomarkers of oxidative and inflammatory stress, and insulin concentrations, induced by a high carbohydrate/fat (HCF) meal. In the present study, we aimed to extend our findings and investigate hypotheses related to the effects of chronic/6-week (wk) strawberry consumption on HCF meal-induced increases in glucose, insulin, and indicators of inflammation and hemostasis. In a crossover design, 14 women and 10 men (mean age, BMI: 50.9±15 years, 29.2±2.3 kg/m(2), respectively), were randomized to a 6-wk strawberry or placebo beverage followed by an HCF meal with assessments for 6-hours (h) postprandially. HCF meal responses after 6-wk strawberry beverage showed significantly attenuated postprandial PAI-1 concentrations compared to the placebo (p =0.002); the difference was most notable at 6 h. The IL-1 β response was attenuated with strawberry compared to the placebo (p =0.05). IL-6 attenuation was apparent but non-significant; IL-6 rose significantly from baseline to 6 h after the HCF meal following a placebo (p ≤0.01), although it remained relatively flat following the strawberry beverage from fasting to 6 h. No significant treatment-related differences were apparent for platelet aggregation, hsCRP, TNF-α, insulin, or glucose. These data are the first to suggest that regular consumption of strawberry, a polyphenolic- and antioxidant-rich fruit, may provide protection from HCF meal-induced increases in fibrinolytic and inflammatory factors in at-risk men and women.

  16. Insensitivity of Astrocytes to Interleukin-10 Signaling following Peripheral Immune Challenge Results in Prolonged Microglial Activation in the Aged Brain

    Science.gov (United States)

    Norden, Diana M.; Trojanowski, Paige J.; Walker, Frederick R.; Godbout, Jonathan P.

    2017-01-01

    Immune-activated microglia from aged mice produce exaggerated levels of cytokines. Despite high levels of microglial IL-10 in the aged brain, neuroinflammation was prolonged and associated with depressive-like deficits. Because astrocytes respond to IL-10 and, in turn, attenuate microglial activation, we investigated if astrocyte-mediated resolution of microglial activation was impaired with age. Here, aged astrocytes had a dysfunctional profile with higher GFAP, lower glutamate transporter expression, and significant cytoskeletal re-arrangement. Moreover, aged astrocytes had reduced expression of growth factors and IL-10 Receptor-1 (IL-10R1). Following in vivo LPS immune challenge, aged astrocytes had a molecular signature associated with reduced responsiveness to IL-10. This IL-10 insensitivity of aged astrocytes resulted in a failure to induce IL-10R1 and TGFβ and resolve microglial activation. Additionally, adult astrocytes reduced microglial activation when co-cultured ex vivo, while aged astrocytes did not. Consistent with the aging studies, IL-10RKO astrocytes did not augment TGFβ after immune challenge and failed to resolve microglial activation. Collectively, a major cytokine-regulatory loop between activated microglia and astrocytes is impaired in the aged brain. PMID:27318131

  17. Natural product HTP screening for antibacterial (E.coli 0157:H7) and anti-inflammatory agents in (LPS from E. coli O111:B4) activated macrophages and microglial cells; focus on sepsis.

    Science.gov (United States)

    Mazzio, Elizabeth A; Li, Nan; Bauer, David; Mendonca, Patricia; Taka, Equar; Darb, Mohammed; Thomas, Leeshawn; Williams, Henry; Soliman, Karam F A

    2016-11-15

    Acute systemic inflammatory response syndrome arising from infection can lead to multiple organ failure and death, with greater susceptibility occurring in immunocompromised individuals. Moreover, sub-acute chronic inflammation is a contributor to the pathology of diverse degenerative diseases (Parkinson's disease, Alzheimer's disease and arthritis). Given the known limitations in Western medicine to treat a broad range of inflammatory related illness as well as the emergence of antibiotic resistance, there is a renewed interest in complementary and alternative medicines (CAMs) to achieve these means. A high throughput (HTP) screening of >1400 commonly sold natural products (bulk herbs, cooking spices, teas, leaves, supplement components, nutraceutical food components, fruit and vegetables, rinds, seeds, polyphenolics etc.) was conducted to elucidate anti-inflammatory substances in lipopolysaccharide (LPS) (E. coli serotype O111:B4) monocytes: RAW 264.7 macrophages [peripheral], BV-2 microglia [brain]) relative to hydrocortisone, dexamethasone and L-N6-(1Iminoethyl)lysine (L-NIL). HTP evaluation was also carried out for lethal kill curves against E.coli 0157:H7 1x10 6 CFU/mL relative to penicillin. Validation studies were performed to assess cytokine profiling using antibody arrays. Findings were corroborated by independent ELISAs and NO2-/iNOS expression quantified using the Griess Reagent and immunocytochemistry, respectively. For robust screening, we developed an in-vitro efficacy paradigm to ensure anti-inflammatory parameters were observed independent of cytotoxicity. This caution was taken given that many plants exert tumoricidal and anti-inflammatory effects at close range through similar signaling pathways, which could lead to false positives. The data show that activated BV-2 microglia cells (+ LPS 1μg/ml) release >10-fold greater IL-6, MIP1/2, RANTES and nitric oxide (NO2-), where RAW 264.7 macrophages (+ LPS 1μg/ml) produced > 10-fold rise in sTNFR2

  18. Interleukin-22 ameliorates liver fibrogenesis by attenuating hepatic stellate cell activation and downregulating the levels of inflammatory cytokines

    Science.gov (United States)

    Lu, Dong-Hong; Guo, Xiao-Yun; Qin, Shan-Yu; Luo, Wei; Huang, Xiao-Li; Chen, Mei; Wang, Jia-Xu; Ma, Shi-Jia; Yang, Xian-Wen; Jiang, Hai-Xing

    2015-01-01

    AIM: To investigate the effect of interleukin (IL)-22 on hepatic fibrosis in mice and the possible mechanism involved. METHODS: Liver fibrosis was induced in male BALB/c mice by CCl4. Recombinant IL-22 (rmIL-22) was administered intraperitoneally in CCl4-treated mice. Fibrosis was assessed by histology and Masson staining. The activation of hepatic stellate cells (HSCs) was investigated by analysis of α-smooth muscle actin expression. The frequencies of T helper (Th) 22 cells, Th17 cells and Th1 cells, the expression of inflammatory cytokines [IL-22, IL-17A, interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), IL-6, IL-1β] and transcription factors [aryl hydrocarbon receptor (AHR), RAR-related orphan receptor (RORγt), T-bet] mRNA in the liver were investigated. In addition, the plasma levels of IL-22, IL-17A, IFN-γ, TNF-α, IL-6 and IL-1β were evaluated. RESULTS: Significant elevations in circulating Th22 cells, Th17 cells, Th1 cells, IL-22, IL-17A, and IFN-γ were observed in the hepatic fibrosis group compared with the control group (P < 0.01). Treatment with rmIL-22 in mice with hepatic fibrosis ameliorated the severity of hepatic fibrosis, which was confirmed by lower hepatic fibrosis pathological scores (P < 0.01). RmIL-22 decreased the frequencies of Th22 cells (6.71% ± 0.97% vs 8.09% ± 0.74%, P < 0.01), Th17 cells (4.34% ± 0.37% vs 5.71% ± 0.24%, P < 0.01), Th1 cells (3.09% ± 0.49% vs 4.91% ± 0.73%, P < 0.01), and the levels of IL-22 (56.23 ± 3.08 vs 70.29 ± 3.01, P < 0.01), IL-17A (30.74 ± 2.77 vs 45.68 ± 2.71, P < 0.01), and IFN-γ (74.78 ± 2.61 vs 124.89 ± 2.82, P < 0.01). Down-regulation of IL-22, IL-17A, IFN-γ, TNF-α, IL-6, IL-1β, AHR RORγt, and T-bet gene expression in the liver was observed in the rmIL-22 group (P < 0.01). CONCLUSION: The frequencies of Th22, Th17 and Th1 cells are elevated in hepatic fibrosis. RmIL-22 can attenuate HSC activation and down-regulate the levels of inflammatory cytokines, thereby ameliorating

  19. A novel imidazopyridine derivative, X22, attenuates sepsis-induced lung and liver injury by inhibiting the inflammatory response in vitro and in vivo.

    Science.gov (United States)

    Ge, Xiangting; Feng, Zhiguo; Xu, Tingting; Wu, Beibei; Chen, Hongjin; Xu, Fengli; Fu, Lili; Shan, Xiaoou; Dai, Yuanrong; Zhang, Yali; Liang, Guang

    2016-01-01

    Sepsis remains a leading cause of death worldwide. Despite years of extensive research, effective drugs to treat sepsis in the clinic are lacking. In this study, we found a novel imidazopyridine derivative, X22, which has powerful anti-inflammatory activity. X22 dose-dependently inhibited lipopolysaccharide (LPS)-induced proinflammatory cytokine production in mouse primary peritoneal macrophages and RAW 264.7 macrophages. X22 also downregulated the LPS-induced proinflammatory gene expression in vitro. In vivo, X22 exhibited a significant protection against LPS-induced death. Pretreatment or treatment with X22 attenuated the sepsis-induced lung and liver injury by inhibiting the inflammatory response. In addition, X22 showed protection against LPS-induced acute lung injury. We additionally found that pretreatment with X22 reduced the inflammatory pain in the acetic acid and formalin models and reduced the dimethylbenzene-induced ear swelling and acetic acid-increased vascular permeability. Together, these data confirmed that X22 has multiple anti-inflammatory effects and may be a potential therapeutic option in the treatment of inflammatory diseases.

  20. Dexmedetomidine attenuates pancreatic injury and inflammatory response in mice with pancreatitis by possible reduction of NLRP3 activation and up-regulation of NET expression.

    Science.gov (United States)

    Li, Yong; Pan, Yiyuan; Gao, Lin; Lu, Guotao; Zhang, Jingzhu; Xie, Xiaochun; Tong, Zhihui; Li, Baiqiang; Li, Gang; Li, Weiqin

    2018-01-22

    Previous studies have shown that acute inflammation is associated with increased sympathetic activity, which in turn increases the inflammatory response and leads to organ damage. The present study aimed to investigate whether dexmedetomidine administration during acute pancreatitis (AP) lessens pancreatic pathological and functional injury and the inflammatory response, and to explore the underlying mechanisms. Mild pancreatitis was induced in mice with caerulein, and severe pancreatitis was induced with caerulein plus lipopolysaccharide (LPS). After pancreatitis induction, dexmedetomidine at 10 or 20 μg/kg was injected via the tail vein. Pancreatic pathological and functional injury was assessed by histology and serum levels of amylase and lipase, respectively. The inflammatory response was evaluated by determining serum levels of inflammatory factors. The expression of myeloperoxidase (MPO) was examined by immunohistochemistry. The expression of norepinephrine transporter (NET), NLRP3, pro-IL-1β, and interleukin (IL)-1β in pancreatic tissue was detected by Western blot and real-time PCR. Dexmedetomidine at 20 μg/kg significantly attenuated pancreatic pathological injury, reduced serum levels of amylase, lipase, IL-1β, IL-6, and tumor necrosis factor (TNF)-α, and decreased the expression of MPO in pancreatic tissue in both mouse models of pancreatitis. In addition, dexmedetomidine at 20 μg/kg significantly down-regulated the expression of NLRP3, pro-IL-1β, and IL-1β in pancreatic tissue, but up-regulated the expression of NET in both mouse models. Dexmedetomidine attenuates pancreatic injury and inflammatory response in mice with pancreatitis possibly by reducing NLRP3 activation and up-regulating NET expression. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. A novel chalcone derivative attenuates the diabetes-induced renal injury via inhibition of high glucose-mediated inflammatory response and macrophage infiltration

    International Nuclear Information System (INIS)

    Fang, Qilu; Zhao, Leping; Wang, Yi; Zhang, Yali; Li, Zhaoyu; Pan, Yong; Kanchana, Karvannan; Wang, Jingying; Tong, Chao; Li, Dan; Liang, Guang

    2015-01-01

    Inflammation plays a central role in the development and progression of diabetic nephropathy (DN). Researches on novel anti-inflammatory agents may offer new opportunities for the treatment of DN. We previously found a chalcone derivative L6H21 could inhibit LPS-induced cytokine release from macrophages. The aim of this study was to investigate whether L6H21 could ameliorate the high glucose-mediated inflammation in NRK-52E cells and attenuate the inflammation-mediated renal injury. According to the results, L6H21 showed a great inhibitory effect on the expression of pro-inflammatory cytokines, cell adhesion molecules, chemokines, and macrophage adhesion via down-regulation of NF-κB/MAPKs activity in high glucose-stimulated renal NRK-52E cells. Further, in vivo oral administration with L6H21 at a dosage of 20 mg/kg/2 days showed a decreased expression of pro-inflammatory cytokines, cell adhesion molecules, which subsequently contributed to the inhibition on renal macrophage infiltration, the reduction of serum creatinine and BUN levels, and the improvement on the fibrosis and pathological changes in the renal tissues of diabetic mice. These findings provided that chalcone derived L6H21 may be a promising anti-inflammatory agent and have the potential in the therapy of diabetic nephropathy, and importantly, MAPK/NF-κB signaling system may be a novel therapeutic target for human DN in the future. - Highlights: • Inflammation plays a central role in the development of diabetic nephropathy. • Compound L6H21 reduced the high glucose-mediated inflammation in NRK-52E cells. • Compound L6H21 attenuated the inflammation-mediated renal injury. • L6H21 exhibited anti-inflammatory effects via inactivation of NF-κB/MAPKs. • MAPKs/NF-κB may be a novel therapeutic target in diabetic nephropathy treatment

  2. A novel chalcone derivative attenuates the diabetes-induced renal injury via inhibition of high glucose-mediated inflammatory response and macrophage infiltration

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Qilu [Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang (China); Zhao, Leping [Department of Pharmacy, the Affiliated Yueqing Hospital, Wenzhou Medical University, Wenzhou, Zhejiang (China); Wang, Yi; Zhang, Yali [Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang (China); Li, Zhaoyu [Department of International High School, Shanghai Jiaotong University Nanyang Affiliated (Kunshan) School, Minhang District, Shanghai (China); Pan, Yong; Kanchana, Karvannan; Wang, Jingying; Tong, Chao [Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang (China); Li, Dan, E-mail: yqyyld@163.com [Department of Nephrology, the Affiliated Yueqing Hospital, Wenzhou Medical University, Wenzhou, Zhejiang (China); Liang, Guang, E-mail: wzmcliangguang@163.com [Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang (China)

    2015-01-15

    Inflammation plays a central role in the development and progression of diabetic nephropathy (DN). Researches on novel anti-inflammatory agents may offer new opportunities for the treatment of DN. We previously found a chalcone derivative L6H21 could inhibit LPS-induced cytokine release from macrophages. The aim of this study was to investigate whether L6H21 could ameliorate the high glucose-mediated inflammation in NRK-52E cells and attenuate the inflammation-mediated renal injury. According to the results, L6H21 showed a great inhibitory effect on the expression of pro-inflammatory cytokines, cell adhesion molecules, chemokines, and macrophage adhesion via down-regulation of NF-κB/MAPKs activity in high glucose-stimulated renal NRK-52E cells. Further, in vivo oral administration with L6H21 at a dosage of 20 mg/kg/2 days showed a decreased expression of pro-inflammatory cytokines, cell adhesion molecules, which subsequently contributed to the inhibition on renal macrophage infiltration, the reduction of serum creatinine and BUN levels, and the improvement on the fibrosis and pathological changes in the renal tissues of diabetic mice. These findings provided that chalcone derived L6H21 may be a promising anti-inflammatory agent and have the potential in the therapy of diabetic nephropathy, and importantly, MAPK/NF-κB signaling system may be a novel therapeutic target for human DN in the future. - Highlights: • Inflammation plays a central role in the development of diabetic nephropathy. • Compound L6H21 reduced the high glucose-mediated inflammation in NRK-52E cells. • Compound L6H21 attenuated the inflammation-mediated renal injury. • L6H21 exhibited anti-inflammatory effects via inactivation of NF-κB/MAPKs. • MAPKs/NF-κB may be a novel therapeutic target in diabetic nephropathy treatment.

  3. The pro-resolving lipid mediator maresin 1 (MaR1 attenuates inflammatory signaling pathways in vascular smooth muscle and endothelial cells.

    Directory of Open Access Journals (Sweden)

    Anuran Chatterjee

    Full Text Available Inflammation and its resolution are central to vascular injury and repair. Maresins comprise a new family of bioactive lipid mediators synthesized from docosahexaenoic acid, an ω-3 polyunsaturated fatty acid. They have been found to exert anti-inflammatory and pro-resolving responses in macrophages, neutrophils and bronchial epithelial cells and impart beneficial actions in murine models of peritonitis and colitis. We investigated the impact of maresin-1 (MaR1 on tumor necrosis factor alpha (TNF-α induced inflammatory responses in human vascular endothelial (EC and smooth muscle cells (VSMC.Primary cultures of human saphenous vein EC and VSMC were employed. We tested the naturally occurring MaR1 as modulator of TNF-α effects, with examination of monocyte adhesion, oxidant stress, and intracellular inflammatory signaling pathways.MaR1 attenuated TNF-α induced monocyte adhesion and reactive oxygen species (ROS generation in both EC and VSMC, associated with down-regulated expression (cell surface of the adhesion molecule E-selectin (in EC and NADPH-oxidases (NOX4, NOX1, NOX2. MaR1 attenuated TNF-α induced release of pro-inflammatory mediators by EC and VSMC. MaR1 caused an attenuation of TNF-α induced NF-κB activation in both cell types associated with inhibition of I-κ Kinase (IKK phosphorylation, IκB-α degradation and nuclear translocation of the NF- κB p65 subunit. MaR1 also caused a time-dependent increase in intracellular cyclic AMP (cAMP in both naive and TNF-α stimulated VSMC and EC.MaR1 has broad anti-inflammatory actions on EC and VSMC, which may be partly mediated through up-regulation of cAMP and down-regulation of the transcription factor NF-κB. The results suggest that the pro-resolving lipid mediator MaR1 exerts homeostatic actions on vascular cells that counteract pro-inflammatory signals. These findings may have direct relevance for acute and chronic states of vascular inflammation.

  4. 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.

  5. Enhancement of LPS-Induced Microglial Inflammation Response via TLR4 Under High Glucose Conditions

    Directory of Open Access Journals (Sweden)

    Xiang Zhang

    2015-03-01

    Full Text Available Background: Microglia activation mediated by toll-like receptor 4 (TLR4 plays an important role in neuroinflammation and postoperative cognitive dysfunction (POCD. Diabetes mellitus (DM has been recently suggested as an independent risk factor for POCD. In this study, we investigate the potential exacerbation of the inflammatory response in primary microglia due to high glucose conditions. Methods: Primary microglial cells were exposed to normal glucose (25 mmol/L and high glucose (35 mmol/L levels alone or with lipopolyscaccharide (LPS 0, 2, 5, 10 ng/mL. The pro-inflammatory response of the cells was assessed by measuring changes in cytokine levels and the evaluation of associated signaling pathways. Results: Neither high glucose nor low LPS (≤5ng/ml alone had an effect on TNF-a and IL-6 levels, but the combination of low LPS and high glucose stimulated the inflammatory response. Analyses of the associated signaling pathways demonstrated that high glucose enhanced the LPS-induced microglial activation via the TLR4/JAK2/STAT3 pathway. Conclusion: This study demonstrates that high glucose, one of the key abnormalities characteristic of DM, can augment LPS-induced microglial activation and inflammatory cytokine levels through the TLR4/JAK2/STAT3 pathway, offering new insight into the pathophysiological relationship between DM and POCD.

  6. The classification of microglial activation phenotypes on neurodegeneration and regeneration in Alzheimer's disease brain.

    Science.gov (United States)

    Varnum, Megan M; Ikezu, Tsuneya

    2012-08-01

    Alzheimer's disease (AD) is a neurodegenerative disease characterized by progressive decline of cognitive function. There is no therapy that can halt or reverse its progression. Contemporary research suggests that age-dependent neuroinflammatory changes may play a significant role in the decreased neurogenesis and cognitive impairments in AD. The innate immune response is characterized by pro-inflammatory (M1) activation of macrophages and subsequent production of specific cytokines, chemokines, and reactive intermediates, followed by resolution and alternative activation for anti-inflammatory signaling (M2a) and wound healing (M2c). We propose that microglial activation phenotypes are analogous to those of macrophages and that their activation plays a significant role in regulating neurogenesis in the brain. Microglia undergo a switch from an M2- to an M1-skewed activation phenotype during aging. This review will assess the neuroimmunological studies that led to characterization of the different microglial activation states in AD mouse models. It will also discuss the roles of microglial activation on neurogenesis in AD and propose anti-inflammatory molecules as exciting therapeutic targets for research. Molecules such as interleukin-4 and CD200 have proven to be important anti-inflammatory mediators in the regulation of neuroinflammation in the brain, which will be discussed in detail for their therapeutic potential.

  7. Epicatechin attenuates atherosclerosis and exerts anti-inflammatory effects on diet-induced human-CRP and NFκB in vivo.

    Science.gov (United States)

    Morrison, Martine; van der Heijden, Roel; Heeringa, Peter; Kaijzel, Eric; Verschuren, Lars; Blomhoff, Rune; Kooistra, Teake; Kleemann, Robert

    2014-03-01

    Previous studies investigating flavanol-rich foods provide indications for potential cardioprotective effects of these foods, but the effects of individual flavanols remain unclear. We investigated whether the flavanol epicatechin can reduce diet-induced atherosclerosis, with particular emphasis on the cardiovascular risk factors dyslipidaemia and inflammation. ApoE*3-Leiden mice were fed a cholesterol-containing atherogenic diet with or without epicatechin (0.1% w/w) to study effects on early- and late-stage atherosclerosis (8 w and 20 w). In vivo effects of epicatechin on diet-induced inflammation were studied in human-CRP transgenic mice and NFκB-luciferase reporter mice. Epicatechin attenuated atherosclerotic lesion area in ApoE*3-Leiden mice by 27%, without affecting plasma lipids. This anti-atherogenic effect of epicatechin was specific to the severe lesion types, with no effect on mild lesions. Epicatechin mitigated diet-induced increases in plasma SAA (in ApoE*3-Leiden mice) and plasma human-CRP (in human-CRP transgenic mice). Microarray analysis of aortic gene expression revealed an attenuating effect of epicatechin on several diet-induced pro-atherogenic inflammatory processes in the aorta (e.g. chemotaxis of cells, matrix remodelling), regulated by NFκB. These findings were confirmed immunohistochemically by reduced lesional neutrophil content in HCE, and by inhibition of diet-induced NFκB activity in epicatechin-treated NFκB-luciferase reporter mice. Epicatechin attenuates development of atherosclerosis and impairs lesion progression from mild to severe lesions in absence of an effect on dyslipidaemia. The observed reduction of circulating inflammatory risk factors by epicatechin (e.g. SAA, human-CRP), as well as its local anti-inflammatory activity in the vessel wall, provide a rationale for epicatechin's anti-atherogenic effects. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  8. Anandamide, Acting via CB2 Receptors, Alleviates LPS-Induced Neuroinflammation in Rat Primary Microglial Cultures

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    Natalia Malek

    2015-01-01

    Full Text Available Microglial activation is a polarized process divided into potentially neuroprotective phenotype M2 and neurotoxic phenotype M1, predominant during chronic neuroinflammation. Endocannabinoid system provides an attractive target to control the balance between microglial phenotypes. Anandamide as an immune modulator in the central nervous system acts via not only cannabinoid receptors (CB1 and CB2 but also other targets (e.g., GPR18/GPR55. We studied the effect of anandamide on lipopolysaccharide-induced changes in rat primary microglial cultures. Microglial activation was assessed based on nitric oxide (NO production. Analysis of mRNA was conducted for M1 and M2 phenotype markers possibly affected by the treatment. Our results showed that lipopolysaccharide-induced NO release in microglia was significantly attenuated, with concomitant downregulation of M1 phenotypic markers, after pretreatment with anandamide. This effect was not sensitive to CB1 or GPR18/GPR55 antagonism. Administration of CB2 antagonist partially abolished the effects of anandamide on microglia. Interestingly, administration of a GPR18/GPR55 antagonist by itself suppressed NO release. In summary, we showed that the endocannabinoid system plays a crucial role in the management of neuroinflammation by dampening the activation of an M1 phenotype. This effect was primarily controlled by the CB2 receptor, although functional cross talk with GPR18/GPR55 may occur.

  9. Resistance exercise attenuates skeletal muscle oxidative stress, systemic pro-inflammatory state, and cachexia in Walker-256 tumor-bearing rats.

    Science.gov (United States)

    Padilha, Camila Souza; Borges, Fernando Henrique; Costa Mendes da Silva, Lilian Eslaine; Frajacomo, Fernando Tadeu Trevisan; Jordao, Alceu Afonso; Duarte, José Alberto; Cecchini, Rubens; Guarnier, Flávia Alessandra; Deminice, Rafael

    2017-09-01

    The aim of this study was to investigate the effects of resistance exercise training (RET) on oxidative stress, systemic inflammatory markers, and muscle wasting in Walker-256 tumor-bearing rats. Male (Wistar) rats were divided into 4 groups: sedentary controls (n = 9), tumor-bearing (n = 9), exercised (n = 9), and tumor-bearing exercised (n = 10). Exercised and tumor-bearing exercised rats were exposed to resistance exercise of climbing a ladder apparatus with weights tied to their tails for 6 weeks. The physical activity of control and tumor-bearing rats was confined to the space of the cage. After this period, tumor-bearing and tumor-bearing exercised animals were inoculated subcutaneously with Walker-256 tumor cells (11.0 × 10 7 cells in 0.5 mL of phosphate-buffered saline) while control and exercised rats were injected with vehicle. Following inoculation, rats maintained resistance exercise training (exercised and tumor-bearing exercised) or sedentary behavior (control and tumor-bearing) for 12 more days, after which they were euthanized. Results showed muscle wasting in the tumor-bearing group, with body weight loss, increased systemic leukocytes, and inflammatory interleukins as well as muscular oxidative stress and reduced mTOR signaling. In contrast, RET in the tumor-bearing exercised group was able to mitigate the reduced body weight and muscle wasting with the attenuation of muscle oxidative stress and systemic inflammatory markers. RET also prevented loss of muscle strength associated with tumor development. RET, however, did not prevent the muscle proteolysis signaling via FBXO32 gene messenger RNA expression in the tumor-bearing group. In conclusion, RET performed prior tumor implantation prevents cachexia development by attenuating tumor-induced systemic pro-inflammatory condition with muscle oxidative stress and muscle damage.

  10. Protein from Hevea brasiliensis “Hev b 13” latex attenuates systemic inflammatory response and lung lesions in rats with sepsis

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    L. A. Araújo

    2017-07-01

    Full Text Available Abstract Sepsis induces a severe systemic inflammatory response that may result in multiple organ dysfunction and death. Studies using a protein derived from natural Hevea brasiliensis (rubber tree latex, denominated Hev b 13, have demonstrated important anti-inflammatory effects, but no data have been published regarding its effects on sepsis. The aim of this study was to investigate the effects of Hev b 13 on the inflammatory response and lung lesions of septal rats. Male Wistar rats were submitted to cecal ligation and puncture (CLP, randomized into groups and treated with subcutaneously administered doses of 0.5/2.0/3.0 mg/Kg of Hev b 13. Next, animals were subdivided into three different points in time (1, 6 and 24 hours after treatments for collection of blood samples and euthanasia accompanied by organ removal. Total and differential leukocyte counts, cytokine dosage and histological assessment were analyzed. Treatment with Hev b 13 resulted in a significant decline in total and differential leukocytes as well as suppression of TNF-α and IL-6 production, associated with the increase in IL-10 and IL-4 in plasma and lung tissue. Moreover, it reduced morphological and pathological changes found in the lungs, including neutrophil infiltration, edema and alveolar thickening. The present study concluded that Hev b 13 exerts anti-inflammatory effects and attenuates lung lesions in septal rats, showing potential for clinical application.

  11. Date syrup-derived polyphenols attenuate angiogenic responses and exhibits anti-inflammatory activity mediated by vascular endothelial growth factor and cyclooxygenase-2 expression in endothelial cells.

    Science.gov (United States)

    Taleb, Hajer; Morris, R Keith; Withycombe, Cathryn E; Maddocks, Sarah E; Kanekanian, Ara D

    2016-07-01

    Bioactive components such as polyphenols, present in many plants, are purported to have anti-inflammatory and antiangiogenic properties. Date syrup, produced from date fruit of the date palm tree, has traditionally been used to treat a wide range of diseases with etiologies involving angiogenesis and inflammation. It was hypothesized that polyphenols in date syrup reduce angiogenic responses such as cell migration, tube formation, and matrix metalloproteinase activity in an inflammatory model by exhibiting anti-inflammatory activity mediated by vascular endothelial growth factor (VEGF) and the prostaglandin enzyme cyclooxygenase-2 (COX-2) in endothelial cells. Date syrup polyphenols at 60 and 600μg/mL reduced inflammation and suppressed several stages of angiogenesis, including endothelial cell migration, invasion, matrix metalloproteinase activity, and tube formation, without evidence of cytotoxicity. VEGF and COX-2 expression induced by tumor necrosis factor-alpha at both gene expression and protein level was significantly reduced by date syrup polyphenols in comparison to untreated cells. In conclusion, polyphenols in date syrup attenuated angiogenic responses and exhibited anti-inflammatory activity mediated by VEGF and COX-2 expression in endothelial cells. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Zhen-wu-tang attenuates cationic bovine serum albumin-induced inflammatory response in membranous glomerulonephritis rat through inhibiting AGEs/RAGE/NF-κB pathway activation.

    Science.gov (United States)

    Wu, Junbiao; Liu, Bihao; Liang, Chunling; Ouyang, Hui; Lin, Jin; Zhong, Yanchun; He, Yu; Zhou, Jie; Zhou, Yuan; Zhou, Jiuyao

    2016-04-01

    Zhen-wu-tang (ZWT), a traditional Chinese compound formula recorded in the Treatise on Febrile Diseases, has significant inhibitory effects on inflammatory damage and oxidative lesions in rats, but its mechanism of action remains unclear. The aim of the present study was to explore whether the anti-inflammatory and anti-oxidative effects of ZWT were mediated by the AGEs/RAGE/NF-κB signaling pathway in rats with cationic bovine serum albumin (C-BSA)-induced membranous glomerulonephritis (MGN). We found that ZWT significantly reduced the production of malondialdehyde (MDA), but enhanced the superoxide dismutase (SOD) activity. The ELISA results showed that ZWT not only reduced the serum levels of AGEs but also decreased the release of inflammatory mediators (TNF-α, IL-1β, and IL-6). Meanwhile, HE staining showed that pathological kidney injury was alleviated by ZWT. In addition, ZWT suppressed the expression of RAGE1 and NF-κB p65, as well as the nuclear translocation of NF-κB p65. The accumulation of AGEs, oxidative lesions and inflammation damage were reduced by an AGE inhibitor. Thus, the present study demonstrates that AGEs play a role in the pathogenesis of MGN and that AGE inhibition could reduce the inflammatory reactions and oxidative lesions in MGN. In general, ZWT attenuated MGN, in part, by inhibiting the AGEs/RAGE/NF-κB pathway. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. α-Asarone Attenuates Cognitive Deficit in a Pilocarpine-Induced Status Epilepticus Rat Modelviaa Decrease in the Nuclear Factor-κB Activation and Reduction in Microglia Neuroinflammation.

    Science.gov (United States)

    Liu, Hui-Juan; Lai, Xin; Xu, Yan; Miao, Jing-Kun; Li, Chun; Liu, Jing-Ying; Hua, Yuan-Yuan; Ma, Qian; Chen, Qixiong

    2017-01-01

    Temporal 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. The 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. The 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 the degradation pathway of kappa B

  14. Microglial-derived microparticles mediate neuroinflammation after traumatic brain injury.

    Science.gov (United States)

    Kumar, Alok; Stoica, Bogdan A; Loane, David J; Yang, Ming; Abulwerdi, Gelareh; Khan, Niaz; Kumar, Asit; Thom, Stephen R; Faden, Alan I

    2017-03-15

    Local and systemic inflammatory responses are initiated early after traumatic brain injury (TBI), and may play a key role in the secondary injury processes resulting in neuronal loss and neurological deficits. However, the mechanisms responsible for the rapid expansion of neuroinflammation and its long-term progression have yet to be elucidated. Here, we investigate the role of microparticles (MP), a member of the extracellular vesicle family, in the exchange of pro-inflammatory molecules between brain immune cells, as well as their transfer to the systemic circulation, as key pathways of inflammation propagation following brain trauma. Adult male C57BL/6 mice were subjected to controlled cortical impact TBI for 24 h, and enriched MP were isolated in the blood, while neuroinflammation was assessed in the TBI cortex. MP were characterized by flow cytometry, and MP content was assayed using gene and protein markers for pro-inflammatory mediators. Enriched MP co-cultured with BV2 or primary microglial cells were used for immune propagation assays. Enriched MP from BV2 microglia or CD11b-positive microglia from the TBI brain were stereotactically injected into the cortex of uninjured mice to evaluate MP-related seeding of neuroinflammation in vivo. As the neuroinflammatory response is developing in the brain after TBI, microglial-derived MP are released into the circulation. Circulating enriched MP from the TBI animals can activate microglia in vitro. Lipopolysaccharide stimulation increases MP release from microglia in vitro and enhances their content of pro-inflammatory mediators, interleukin-1β and microRNA-155. Enriched MP from activated microglia in vitro or CD11b-isolated microglia/macrophage from the TBI brain ex vivo are sufficient to initiate neuroinflammation following their injection into the cortex of naïve (uninjured) animals. These data provide further insights into the mechanisms underlying the development and dissemination of neuroinflammation after

  15. Nebulized Recombinant Human Tissue Factor Pathway Inhibitor Attenuates Coagulation and Exerts Modest Anti-inflammatory Effects in Rat Models of Lung Injury.

    Science.gov (United States)

    van den Boogaard, Florry E; Hofstra, Jorrit J; Brands, Xanthe; Levi, Marcel M; Roelofs, Joris J T H; Zaat, Sebastiaan A J; Van't Veer, Cornelis; van der Poll, Tom; Schultz, Marcus J

    2017-04-01

    Critically ill patients are at a constant risk of direct (e.g., by pneumonia) or indirect lung injury (e.g., by sepsis). Excessive alveolar fibrin deposition is a prominent feature of lung injury, undermining pulmonary integrity and function. We examined the effect of local administration of recombinant human tissue factor pathway inhibitor (rh-TFPI), a natural anticoagulant, in two well-established models of lung injury in rats. Rats received intratracheal instillation of Pseudomonas aeruginosa, causing direct lung injury, or they received an intravenous injection of Escherichia coli lipopolysaccharide (LPS), causing indirect lung injury. Rats were randomized to local treatment with rh-TFPI or placebo through repeated nebulization. Challenge with P. aeruginosa or LPS was associated with increased coagulation and decreased fibrinolysis in bronchoalveolar lavage fluid (BALF) and plasma. Rh-TFPI levels in BALF increased after nebulization, whereas plasma rh-TFPI levels remained low and systemic TFPI activity was not affected. Nebulization of rh-TFPI attenuated pulmonary and systemic coagulation in both models, without affecting fibrinolysis. Nebulization of rh-TFPI modestly reduced the inflammatory response and bacterial growth of P. aeruginosa in the alveolar compartment. Local treatment with rh-TFPI does not alter systemic TFPI activity; however, it attenuates both pulmonary and systemic coagulopathy. Furthermore, nebulized rh-TFPI modestly reduces the pulmonary inflammatory response and allows increased bacterial clearance in rats with direct lung injury caused by P. aeruginosa.

  16. Dok2 mediates the CD200Fc attenuation of Aβ-induced changes in glia

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    Lyons Anthony

    2012-05-01

    Full Text Available Abstract Background The interaction between the membrane glycoprotein, CD200 and its cognate receptor CD200 receptor (CD200R, has been shown to play a role in maintaining microglia in a quiescent state. There is evidence of increased activation under resting and stimulated conditions in microglia prepared from CD200-deficient mice compared with wild-type mice, whereas activation of the receptor by CD200 fusion protein (CD200Fc ameliorates inflammatory changes which are evident in the central nervous system (CNS of the mouse model of multiple sclerosis (MS, experimental autoimmune encephalomyelitis (EAE and also in the hippocampus of aged rats. Additionally, an inverse relationship between microglial activation and expression of CD200 has been observed in animals treated with lipopolysaccharide (LPS or amyloid-β (Aβ. Methods We assessed the effect of CD200R activation by CD200Fc on Aβ-induced production of the pro-inflammatory cytokines, interleukin-1β (IL-1β and tumor necrosis factor-α (TNFα and the expression of microglial activation markers, CD68 and CD40 in cultured glia. The role played by downstream of tyrosine kinase 2 (Dok2 phosphorylation in mediating the effects of CD200R activation was evaluated by siRNA knockdown of Dok2. To further examine the impact of inflammatory changes on synaptic plasticity, the effect of CD200Fc on Aβ-induced impairment of long-term potentiation (LTP in the CA1 region of hippocampal slices was also investigated. Results We demonstrate that Aβ-induced increases in IL-1β, TNFα, CD68 and CD40 were inhibited by CD200Fc. The evidence suggests that Dok2 phosphorylation is a key factor in mediating the effect of CD200Fc, since Dok2 knockdown by siRNA abrogated its effects on microglial activation and inflammatory cytokine production. Consistent with evidence that inflammatory changes negatively impact on LTP, we show that the Aβ-induced impairment of LTP was attenuated by CD200Fc. Conclusions The findings

  17. 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-inflammatory

  18. Importance of TLR2 on hepatic immune and non-immune cells to attenuate the strong inflammatory liver response during Trypanosoma cruzi acute infection.

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    Eugenio Antonio Carrera-Silva

    Full Text Available BACKGROUND: Toll-like receptors (TLR and cytokines play a central role in the pathogen clearance as well as in pathological processes. Recently, we reported that TLR2, TLR4 and TLR9 are differentially modulated in injured livers from BALB/c and C57BL/6 (B6 mice during Trypanosoma cruzi infection. However, the molecular and cellular mechanisms involved in local immune response remain unclear. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we demonstrate that hepatic leukocytes from infected B6 mice produced higher amounts of pro-inflammatory cytokines than BALB/c mice, whereas IL10 and TGFβ were only released by hepatic leukocytes from BALB/c. Strikingly, a higher expression of TLR2 and TLR4 was observed in hepatocytes of infected BALB/c mice. However, in infected B6 mice, the strong pro-inflammatory response was associated with a high and sustained expression of TLR9 and iNOS in leukocytes and hepatic tissue respectively. Additionally, co-expression of gp91- and p47-phox NADPH oxidase subunits were detected in liver tissue of infected B6 mice. Notably, the pre-treatment previous to infection with Pam3CSK4, TLR2-agonist, induced a significant reduction of transaminase activity levels and inflammatory foci number in livers of infected B6 mice. Moreover, lower pro-inflammatory cytokines and increased TGFβ levels were detected in purified hepatic leukocytes from TLR2-agonist pre-treated B6 mice. CONCLUSIONS/SIGNIFICANCE: Our results describe some of the main injurious signals involved in liver immune response during the T. cruzi acute infection. Additionally we show that the administration of Pam3CSk4, previous to infection, can attenuate the exacerbated inflammatory response of livers in B6 mice. These results could be useful to understand and design novel immune strategies in controlling liver pathologies.

  19. Necrotic neurons enhance microglial neurotoxicity through induction of glutaminase by a MyD88-dependent pathway

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    Braz Maria H

    2008-10-01

    Full Text Available Abstract Background Microglia are macrophage-like cells that constantly sense the microenvironment within the central nervous system (CNS. In the event of neuronal stress or injury, microglial cells rapidly react and change their phenotype. This response may lead to a deleterious type of microglial activation, which is often associated with neuroinflammation and neurotoxicity in several neuropathological conditions. We investigated the molecular mechanisms underlying triggering of microglial activation by necrotic neuronal damage. Methods Primary cultures of microglia were used to study the effect of necrotic neurons on microglial inflammatory responses and toxicity towards cerebellar granule neurons (CGN. The mouse hippocampal cell line, HT22, was used in this study as the main source of necrotic neurons to stimulate microglia. To identify the signal transduction pathways activated in microglia, primary microglial cultures were obtained from mice deficient in Toll-like receptor (TLR -2, -4, or in the TLR adapter protein MyD88. Results Necrotic neurons, but not other necrotic cell types, induced microglial activation which was characterized by up-regulation of: i MHC class II; ii co-stimulatory molecules, i.e. CD40 and CD24; iii β2 integrin CD11b; iii pro-inflammatory cytokines, i.e. interleukin 6 (IL-6, IL-12p40 and tumor-necrosis factor (TNF; iv pro-inflammatory enzymes such as nitric oxide synthase (iNOS, type II NOS, indoleamine 2,3-dioxygenase (IDO and cyclooxygenase-2 (COX-2 and increased microglial motility. Moreover, microglia-conditioned medium (MCM obtained from cultures of activated microglia showed increased neurotoxicity mediated through the N-methyl-D-aspartate receptor (NMDAR. The activation of microglia by necrotic neurons was shown to be dependent on the TLR-associated adapter molecule myeloid differentiation primary response gene (MyD88. Furthermore, MyD88 mediated enhanced neurotoxicity by activated microglia through up

  20. Low-methoxyl lemon pectin attenuates inflammatory responses and improves intestinal barrier integrity in caerulein-induced experimental acute pancreatitis

    NARCIS (Netherlands)

    Sun, Yajun; He, Yue; Wang, Fei; Zhang, Hao; de Vos, Paul; Sun, Jia

    Scope: Acute pancreatitis (AP) is a common clinical acute abdominal disease. The intestinal injury associated with AP will aggravate the condition retroactively. This study investigates whether the low-methoxyl pectin (LMP) isolated from lemon could attenuate AP and associated intestinal injury.

  1. 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

  2. UVB promotes the initiation of uveitic inflammatory injury in vivo and is attenuated by UV-blocking protection.

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    Shao, Yi-Ching; Liou, Jyh-Cheng; Kuo, Chan-Yen; Tsai, Yun-Shan; Lin, En-Chieh; Hsieh, Ching-Ju; Lin, Si-Ping; Chen, Bo-Yie

    2017-01-01

    Uveitic inflammatory injury can cause irreversible visual loss; however, no single animal model recapitulates all the characteristics of human uveitis. Ultraviolet radiation (UVR) is one of the risk factors for uveitis, but the role of UVR in the pathogenesis of uveitic injury is unclear. The aim of this study was to elucidate whether UVB promotes the initiation of, and subsequently contributes to, uveitic inflammatory injury. Mice were assigned to either a blank control group or one of three UVB treatment groups: no protection, protection with Nelfilcon A contact lens (Food and Drug Administration [FDA] class II, about 46.8% UVB transmittance), or protection with Etafilcon A contact lens (FDA class IV, about 0.55% UVB transmittance). The contact lenses acted as blocking barriers against UVR. After the application of UVR, pathologic injuries were determined with slit-lamp microscopy and histologic examination. Compared with the intact status of the controls, the anterior eyes of the UVB groups showed pathologic alterations in physiologic properties and tissue integrity. UVR promoted anterior uveitic inflammatory injury, with expansion of the hyperemic iris vessels, over-production of aqueous humor protein, disruption of the blood-aqueous barrier, and embedding of infiltrative leukocytes inside the iridocorneal angle. However, blockage of UVR in vivo retarded the progression of uveitic inflammatory injury. The highest level of UV protection in the Etafilcon A group resulted in greater inhibition of uveitic inflammatory injury than that in the Nelfilcon A group. This study demonstrates that UVB initiated and promoted uveitic inflammatory injury. UV protection is needed for the clinical management of anterior uveitis. The Etafilcon A lenses provide better protection of the anterior segment of the eye against UVB damage compared with the Nelfilcon A lenses.

  3. Hydrogen sulfide in paraventricular nucleus attenuates blood pressure by regulating oxidative stress and inflammatory cytokines in high salt-induced hypertension.

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    Liang, Yan-Feng; Zhang, Dong-Dong; Yu, Xiao-Jing; Gao, Hong-Li; Liu, Kai-Li; Qi, Jie; Li, Hong-Bao; Yi, Qiu-Yue; Chen, Wen-Sheng; Cui, Wei; Zhu, Guo-Qing; Kang, Yu-Ming

    2017-03-15

    Hydrogen sulfide (H 2 S) is an important gaseous signaling molecule in neuro-modulation, anti-inflammatory, anti-oxidant and anti-hypertensive effects. The paraventricular nucleus (PVN) is a major integrative nucleus in regulating BP and SNA. The aim of this study is to explore whether endogenous or exogenous H 2 S changed by hydroxylamine hydrochloride (HA) or GYY4137 infused in the PVN affects RSNA and MAP by regulating oxidative stress or the balance between pro-inflammatory cytokines (PICs) and anti-inflammatory cytokines in high salt-induced hypertensive rats. Male Dahl rats were fed by high-salt or normal-salt diet. At the end of the 4th week, GYY4137, HA or vehicle was microinjected into bilateral PVN for 6 weeks. The levels of MAP, HR, plasma norepinephrine (NE), reactive oxygen species (ROS), NOX2, NOX4 and IL-1β were increased significantly in high salt-induced hypertensive rats. Higher levels of these parameters were detected in the group treated by HA, but lower levels in the GYY4137 group. The trends of H 2 S, CBS, IL-10 and Cu/Zn SOD were opposite to the parameters described above. These findings suggest that endogenous or exogenous H 2 S in the PVN attenuates sympathetic activity and hypertensive response, which are partly due to decrease of ROS and PICs within the PVN in high salt-induced hypertension. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Curcumin attenuates inflammatory responses by suppressing TLR4-mediated NF-κB signaling pathway in lipopolysaccharide-induced mastitis in mice.

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    Fu, Yunhe; Gao, Ruifeng; Cao, Yongguo; Guo, Mengyao; Wei, Zhengkai; Zhou, Ershun; Li, Yimeng; Yao, Minjun; Yang, Zhengtao; Zhang, Naisheng

    2014-05-01

    Curcumin, the main constituent of the spice turmeric, has been reported to have potent anti-inflammatory properties. However, the effect of curcumin on lipopolysaccharide (LPS)-induced mice mastitis has not been investigated. The aim of this study was to investigate whether curcumin could ameliorate the inflammation response in LPS-induced mice mastitis and to clarify the possible mechanism. The mouse model of mastitis was induced by injection of LPS through the duct of the mammary gland. Curcumin was applied 1h before and 12h after LPS treatment. The results showed that curcumin attenuated the infiltration of inflammatory cells, the activity of myeloperoxidase (MPO), and the expression of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) in a dose-dependent manner. Additionally, Western blotting results showed that curcumin inhibited the phosphorylation of IκB-α and NF-κB p65 and the expression of TLR4. These results indicated that curcumin has protective effect on mice mastitis and the anti-inflammatory mechanism of curcumin on LPS-induced mastitis in mice may be due to its ability to inhibit TLR4-mediated NF-κB signaling pathways. Curcumin may be a potential therapeutic agent against mastitis. Copyright © 2014 Elsevier B.V. All rights reserved.

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

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    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.

  6. Resveratrol Attenuates Acute Inflammatory Injury in Experimental Subarachnoid Hemorrhage in Rats via Inhibition of TLR4 Pathway

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    Xiang-Sheng Zhang

    2016-08-01

    Full Text Available Toll-like receptor 4 (TLR4 has been proven to play a critical role in neuroinflammation and to represent an important therapeutic target following subarachnoid hemorrhage (SAH. Resveratrol (RSV, a natural occurring polyphenolic compound, has a powerful anti-inflammatory property. However, the underlying molecular mechanisms of RSV in protecting against early brain injury (EBI after SAH remain obscure. The purpose of this study was to investigate the effects of RSV on the TLR4-related inflammatory signaling pathway and EBI in rats after SAH. A prechiasmatic cistern SAH model was used in our experiment. The expressions of TLR4, high-mobility group box 1 (HMGB1, myeloid differentiation factor 88 (MyD88, and nuclear factor-κB (NF-κB were evaluated by Western blot and immunohistochemistry. The expressions of Iba-1 and pro-inflammatory cytokines in brain cortex were determined by Western blot, immunofluorescence staining, or enzyme-linked immunosorbent assay. Neural apoptosis, brain edema, and neurological function were further evaluated to investigate the development of EBI. We found that post-SAH treatment with RSV could markedly inhibit the expressions of TLR4, HMGB1, MyD88, and NF-κB. Meanwhile, RSV significantly reduced microglia activation, as well as inflammatory cytokines leading to the amelioration of neural apoptosis, brain edema, and neurological behavior impairment at 24 h after SAH. However, RSV treatment failed to alleviate brain edema and neurological deficits at 72 h after SAH. These results indicated that RSV treatment could alleviate EBI after SAH, at least in part, via inhibition of TLR4-mediated inflammatory signaling pathway.

  7. Tanshinone IIA attenuates the inflammatory response and apoptosis after traumatic injury of the spinal cord in adult rats.

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    Xin Yin

    Full Text Available BACKGROUND: Spinal cord injury (SCI, including immediate mechanical injury and secondary injury, is associated with the inflammatory response, apoptosis and oxidative stress in response to traumatic injury. Tanshinone IIA (TIIA is one of the major extracts obtained from Salvia miltiorrhiza BUNGE, which has anti-inflammatory and anti-apoptotic effects on many diseases. However, little is known about the effects of TIIA treatment on SCI. Therefore, the aim of the present study is to evaluate the pharmacological action of TIIA on secondary damage and the underlying mechanisms of experimental SCI in rats. METHODOLOGY/PRINCIPAL FINDINGS: SCI was generated using a weight drop device on the dorsal spinal cord via a two-level T9-T11 laminectomy. SCI in rats resulted in severe trauma, characterized by locomotor disturbance, edema, neutrophil infiltration, the production of astrocytes and inflammatory mediators, apoptosis and oxidative stress. TIIA treatment (20 mg/kg, i.p. after SCI induced significant effects: (1 improved motor function (Basso, Beattie and Bresnahan scores, (2 reduced the degree of tissue injury (histological score, neutrophil infiltration (myeloperoxidase activity and the expression of astrocytes, (3 inhibited the activation of SCI-related pathways, such as NF-κB and MAPK signaling pathways, (4 decreased the production of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6 and iNOS, (5 reduced apoptosis (TUNEL staining, and Bcl-2 and caspase-3 expression and (6 reversed the redox state imbalance. CONCLUSIONS/SIGNIFICANCE: The results clearly show that TIIA has a prominent protective effect against SCI through inhibiting the inflammatory response and apoptosis in the spinal cord tissue after SCI.

  8. Tanshinone IIA attenuates the inflammatory response and apoptosis after traumatic injury of the spinal cord in adult rats.

    Science.gov (United States)

    Yin, Xin; Yin, Yue; Cao, Fa-Le; Chen, Yu-Fei; Peng, Ye; Hou, Wu-Gang; Sun, Shu-Kai; Luo, Zhuo-Jing

    2012-01-01

    Spinal cord injury (SCI), including immediate mechanical injury and secondary injury, is associated with the inflammatory response, apoptosis and oxidative stress in response to traumatic injury. Tanshinone IIA (TIIA) is one of the major extracts obtained from Salvia miltiorrhiza BUNGE, which has anti-inflammatory and anti-apoptotic effects on many diseases. However, little is known about the effects of TIIA treatment on SCI. Therefore, the aim of the present study is to evaluate the pharmacological action of TIIA on secondary damage and the underlying mechanisms of experimental SCI in rats. SCI was generated using a weight drop device on the dorsal spinal cord via a two-level T9-T11 laminectomy. SCI in rats resulted in severe trauma, characterized by locomotor disturbance, edema, neutrophil infiltration, the production of astrocytes and inflammatory mediators, apoptosis and oxidative stress. TIIA treatment (20 mg/kg, i.p.) after SCI induced significant effects: (1) improved motor function (Basso, Beattie and Bresnahan scores), (2) reduced the degree of tissue injury (histological score), neutrophil infiltration (myeloperoxidase activity) and the expression of astrocytes, (3) inhibited the activation of SCI-related pathways, such as NF-κB and MAPK signaling pathways, (4) decreased the production of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) and iNOS, (5) reduced apoptosis (TUNEL staining, and Bcl-2 and caspase-3 expression) and (6) reversed the redox state imbalance. The results clearly show that TIIA has a prominent protective effect against SCI through inhibiting the inflammatory response and apoptosis in the spinal cord tissue after SCI.

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

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    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.

  10. Bisphenol A exposure induces increased microglia and microglial related factors in the murine embryonic dorsal telencephalon and hypothalamus.

    Science.gov (United States)

    Takahashi, Mifumi; Komada, Munekazu; Miyazawa, Ken; Goto, Shigemi; Ikeda, Yayoi

    2018-03-01

    Bisphenol A (BPA) is a widely used compound in the food packaging industry. Prenatal exposure to BPA induces histological abnormalities in the neocortex and hypothalamus in association with abnormal behaviors. Yet, the molecular and cellular neurodevelopmental toxicological mechanisms of BPA are incompletely characterized on neuroinflammatory-related endopoints. To evaluate the neurodevelopmental effects of BPA exposure in mouse embryos, we examined microglial numbers as well as the expression of microglial-related factors in the E15.5 embryonic brain. BPA-exposed embryos exhibited significant increases in Iba1-immunoreactive microglial numbers in the dorsal telencephalon and the hypothalamus compared to control embryos. Further, the expression levels of microglial markers (Iba1, CD16, iNOS, and CD206), inflammatory factors (TNFα and IL4), signal transducing molecules (Cx3Cr1 and Cx3Cl1), and neurotrophic factor (IGF1) were altered in BPA-exposed embryos. These findings suggest that BPA exposure increases microglial numbers in the brain and alters the neuroinflammatory status at a transcriptional level. Together, these changes may represent a novel target for neurodevelopmental toxicity assessment after BPA exposure. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Escin attenuates cognitive deficits and hippocampal injury after transient global cerebral ischemia in mice via regulating certain inflammatory genes.

    Science.gov (United States)

    Zhang, Leiming; Fu, Fenghua; Zhang, Xiumei; Zhu, Mei; Wang, Tian; Fan, Huaying

    2010-09-01

    Considerable evidence has been accumulated demonstrating an important role for inflammation in ischemic brain injury and its contribution to greater cerebral damage after ischemia. Blocking the inflammatory reaction promotes neuroprotection and shows therapeutic potential for clinical treatment of ischemic brain injury. Escin, a natural mixture of triterpenoid saponin isolated from the seed of the horse chestnut, demonstrates antiedematous and anti-inflammatory effects. Here we assessed neuroprotective effects of escin with a transient global cerebral ischemia model. Global cerebral ischemia was induced by occluding both common carotid arteries and withdrawing 0.3ml of blood from the tail vein in mice. Treatment with escin was initiated 0.5h after ischemia induction and given once a day for three consecutive days. Then animals were assessed using the Morris water-maze test and step-down passive avoidance test. Acetylcholinesterase (AChE) activity, histological pathology, and expression of inflammatory genes in the hippocampus were determined. The results showed escin significantly improved learning and memory recovery and reduced hippocampal damage in the cerebral ischemic mice. However, donepezil merely improved learning and memory recovery but did not ameliorate hippocampal damage in the cerebral ischemic mice. Furthermore, we found escin significantly downregulated certain inflammatory gene expression and upregulated expression of granulocyte-macrophage colony-stimulating factor (GM-CSF), which was recently reported as a neuroprotective protein in the brain. Our results indicate that inhibition of inflammation and protection of hippocampal neurons by escin may be a potentially useful therapy for ischemic brain injury. Copyright 2010 Elsevier Ltd. All rights reserved.

  12. Low-level laser therapy regulates microglial function through Src-mediated signaling pathways: implications for neurodegenerative diseases

    Directory of Open Access Journals (Sweden)

    Song Sheng

    2012-09-01

    Full Text Available Abstract Background Activated microglial cells are an important pathological component in brains of patients with neurodegenerative diseases. The purpose of this study was to investigate the effect of He-Ne (632.8 nm, 64.6 mW/cm2 low-level laser therapy (LLLT, a non-damaging physical therapy, on activated microglia, and the subsequent signaling events of LLLT-induced neuroprotective effects and phagocytic responses. Methods To model microglial activation, we treated the microglial BV2 cells with lipopolysaccharide (LPS. For the LLLT-induced neuroprotective study, neuronal cells with activated microglial cells in a Transwell™ cell-culture system were used. For the phagocytosis study, fluorescence-labeled microspheres were added into the treated microglial cells to confirm the role of LLLT. Results Our results showed that LLLT (20 J/cm2 could attenuate toll-like receptor (TLR-mediated proinflammatory responses in microglia, characterized by down-regulation of proinflammatory cytokine expression and nitric oxide (NO production. LLLT-triggered TLR signaling inhibition was achieved by activating tyrosine kinases Src and Syk, which led to MyD88 tyrosine phosphorylation, thus impairing MyD88-dependent proinflammatory signaling cascade. In addition, we found that Src activation could enhance Rac1 activity and F-actin accumulation that typify microglial phagocytic activity. We also found that Src/PI3K/Akt inhibitors prevented LLLT-stimulated Akt (Ser473 and Thr308 phosphorylation and blocked Rac1 activity and actin-based microglial phagocytosis, indicating the activation of Src/PI3K/Akt/Rac1 signaling pathway. Conclusions The present study underlines the importance of Src in suppressing inflammation and enhancing microglial phagocytic function in activated microglia during LLLT stimulation. We have identified a new and important neuroprotective signaling pathway that consists of regulation of microglial phagocytosis and inflammation under LLLT

  13. Cannabidiol protects against hepatic ischemia/reperfusion injury by attenuating inflammatory signaling and response, oxidative/nitrative stress, and cell death

    Science.gov (United States)

    Mukhopadhyay, Partha; Rajesh, Mohanraj; Horváth, Béla; Bátkai, Sándor; Park, Ogyi; Tanashian, Galin; Gao, Rachel Y; Patel, Vivek; Wink, David A.; Liaudet, Lucas; Haskó, György; Mechoulam, Raphael; Pacher, Pál

    2011-01-01

    Ischemia-reperfusion (I/R) is a pivotal mechanism of liver damage following liver transplantation or hepatic surgery. We have investigated the effects of cannabidiol(CBD), the non-psychotropic constituent of marijuana, in a mouse model of hepatic I/R injury. I/R triggered time-dependent increases/changes in markers of liver injury (serum transaminases), hepatic oxidative/nitrative stress (4-hydroxy-2-nonenal, nitrotyrosine content/staining, gp91phox and inducible nitric oxide synthase mRNA), mitochondrial dysfunction (decreased complex I activity), inflammation (tumor necrosis factor alpha (TNF-α), cyclooxygenase 2, macrophage inflammatory protein-1α/2, inter-cellular adhesion molecule 1 mRNA levels, tissue neutrophil infiltration, nuclear factor kappa B (NF-KB) activation), stress signaling (p38MAPK and JNK) and cell death (DNA fragmentation, PARP activity, and TUNEL). CBD significantly reduced the extent of liver inflammation, oxidative/nitrative stress and cell death, and also attenuated the bacterial endotoxin-triggered NF-KB activation and TNF-α production in isolated Kupffer cells, likewise the adhesion molecules expression in primary human liver sinusoidal endothelial cells stimulated with TNF-α, and attachment of human neutrophils to the activated endothelium. These protective effects were preserved in CB2 knockout mice and were not prevented by CB1/2 antagonists in vitro. Thus, CBD may represent a novel, protective strategy against I/R injury by attenuating key inflammatory pathways and oxidative/nitrative tissue injury, independent from classical CB1/2 receptors. PMID:21362471

  14. A Novel Combination of Wheat Peptides and Fucoidan Attenuates Ethanol-Induced Gastric Mucosal Damage through Anti-Oxidant, Anti-Inflammatory, and Pro-Survival Mechanisms

    Directory of Open Access Journals (Sweden)

    Juntao Kan

    2017-09-01

    Full Text Available Gastritis or peptic ulcer is believed to affect about half of people worldwide. Traditional medications can lead to adverse effects, therefore, alternative nutritional strategies are needed to prevent the development of gastric mucosal damage. A novel combination of two food-grade ingredients, wheat peptides and fucoidan (WPF, was prepared to treat male Sprague Dawley rats for 30 days before gastric mucosal damage was induced by oral administration of ethanol. The serum levels of biomarkers were determined by enzyme-linked immunosorbent assay. Biomarkers in stomach tissue were analyzed using immunohistochemistry. In addition, human gastric epithelial cell line (GES-1 was used to investigate protein expression by Western blot. WPF could attenuate ethanol-induced gastric mucosal damage in an inverse dose-dependent manner, with both ulcer index and pathological index improved. WPF increased superoxide dismutase level and decreased malondialdehyde level. WPF also decreased the levels of interleukin-8, platelet-activating factor, and Caspase 3, while increasing the levels of prostaglandin E-2, epidermal growth factor (EGF, and EGF receptor (EGFR. Furthermore, phosphorylation of EGFR and extracellular signal–regulated kinases was induced by WPF in GES-1 cells. In conclusion, the novel combination of wheat peptides and fucoidan attenuated ethanol-induced gastric mucosal damage in rats through anti-oxidant, anti-inflammatory, and pro-survival mechanisms.

  15. Mechanisms of microglial activation in models of inflammation and hypoxia: Implications for chronic intermittent hypoxia.

    Science.gov (United States)

    Kiernan, Elizabeth A; Smith, Stephanie M C; Mitchell, Gordon S; Watters, Jyoti J

    2016-03-15

    Chronic intermittent hypoxia (CIH) is a hallmark of sleep apnoea, a condition associated with diverse clinical disorders. CIH and sleep apnoea are characterized by increased reactive oxygen species formation, peripheral and CNS inflammation, neuronal death and neurocognitive deficits. Few studies have examined the role of microglia, the resident CNS immune cells, in models of CIH. Thus, little is known concerning their direct contributions to neuropathology or the cellular mechanisms regulating their activities during or following pathological CIH. In this review, we identify gaps in knowledge regarding CIH-induced microglial activation, and propose mechanisms based on data from related models of hypoxia and/or hypoxia-reoxygenation. CIH may directly affect microglia, or may have indirect effects via the periphery or other CNS cells. Peripheral inflammation may indirectly activate microglia via entry of pro-inflammatory molecules into the CNS, and/or activation of vagal afferents that trigger CNS inflammation. CIH-induced release of damage-associated molecular patterns from injured CNS cells may also activate microglia via interactions with pattern recognition receptors expressed on microglia. For example, Toll-like receptors activate mitogen-activated protein kinase/transcription factor pathways required for microglial inflammatory gene expression. Although epigenetic effects from CIH have not yet been studied in microglia, potential epigenetic mechanisms in microglial regulation are discussed, including microRNAs, histone modifications and DNA methylation. Epigenetic effects can occur during CIH, or long after it has ended. A better understanding of CIH effects on microglial activities may be important to reverse CIH-induced neuropathology in patients with sleep disordered breathing. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

  16. 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

  17. Inflammatory Renin-Angiotensin System Disruption Attenuates Sensory Hyperinnervation and Mechanical Hypersensitivity in a Rat Model of Provoked Vestibulodynia.

    Science.gov (United States)

    Chakrabarty, Anuradha; Liao, Zhaohui; Mu, Ying; Smith, Peter G

    2018-03-01

    Vestibulodynia is characterized by perivaginal mechanical hypersensitivity, hyperinnervation, and abundant inflammatory cells expressing renin-angiotensin system proteins. We developed a tractable rat model of vestibulodynia to further assess the contributions of the renin-angiotensin system. Complete Freund's adjuvant injected into the posterior vestibule induced marked vestibular hypersensitivity throughout a 7-day test period. Numbers of axons immunoreactive for PGP9.5, calcitonin gene-related peptide, and GFRα2 were increased. Numbers of macrophages and T cells were also increased whereas B cells were not. Renin-angiotensin-associated proteins were abundant, with T cells as well as macrophages contributing to increased renin and angiotensinogen. Media conditioned with inflamed vestibular tissue promoted neurite sprouting by rat dorsal root ganglion neurons in vitro, and this was blocked by the angiotensin II receptor type 2 receptor antagonist PD123319 or by an angiotensin II function blocking antibody. Sensory axon sprouting induced by inflamed tissue was dependent on activity of angiotensin-converting enzyme or chymase, but not cathepsin G. Thus, vestibular Complete Freund's adjuvant injection substantially recapitulates changes seen in patients with provoked vestibulodynia, and shows that manipulation of the local inflammatory renin-angiotensin system may be a useful therapeutic strategy. This study provides evidence that inflammation of the rat vestibule induces a phenotype recapitulating behavioral and cytological features of human vestibulodynia. The model confirms a crucial role of the local inflammatory renin-angiotensin system in hypersensitivity and hyperinnervation. Targeting this system holds promise for developing new nonopioid analgesic treatment strategies. Copyright © 2017 The American Pain Society. Published by Elsevier Inc. All rights reserved.

  18. sGC(alpha)1(beta)1 attenuates cardiac dysfunction and mortality in murine inflammatory shock models.

    Science.gov (United States)

    Buys, Emmanuel S; Cauwels, Anje; Raher, Michael J; Passeri, Jonathan J; Hobai, Ion; Cawley, Sharon M; Rauwerdink, Kristen M; Thibault, Helene; Sips, Patrick Y; Thoonen, Robrecht; Scherrer-Crosbie, Marielle; Ichinose, Fumito; Brouckaert, Peter; Bloch, Kenneth D

    2009-08-01

    Altered cGMP signaling has been implicated in myocardial depression, morbidity, and mortality associated with sepsis. Previous studies, using inhibitors of soluble guanylate cyclase (sGC), suggested that cGMP generated by sGC contributed to the cardiac dysfunction and mortality associated with sepsis. We used sGC(alpha)(1)-deficient (sGC(alpha)(1)(-/-)) mice to unequivocally determine the role of sGC(alpha)(1)beta(1) in the development of cardiac dysfunction and death associated with two models of inflammatory shock: endotoxin- and TNF-induced shock. At baseline, echocardiographic assessment and invasive hemodynamic measurements of left ventricular (LV) dimensions and function did not differ between wild-type (WT) mice and sGC(alpha)(1)(-/-) mice on the C57BL/6 background (sGC(alpha)(1)(-/-B6) mice). At 14 h after endotoxin challenge, cardiac dysfunction was more pronounced in sGC(alpha)(1)(-/-B6) than WT mice, as assessed using echocardiographic and hemodynamic indexes of LV function. Similarly, Ca(2+) handling and cell shortening were impaired to a greater extent in cardiomyocytes isolated from sGC(alpha)(1)(-/-B6) than WT mice after endotoxin challenge. Importantly, morbidity and mortality associated with inflammatory shock induced by endotoxin or TNF were increased in sGC(alpha)(1)(-/-B6) compared with WT mice. Together, these findings suggest that cGMP generated by sGC(alpha)(1)beta(1) protects against cardiac dysfunction and mortality in murine inflammatory shock models.

  19. 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.

  20. The Sirt1 activator SRT1720 attenuates angiotensin II-induced atherosclerosis in apoE−/− mice through inhibiting vascular inflammatory response

    International Nuclear Information System (INIS)

    Chen, Yi xi; Zhang, Man; Cai, Yuehua; Zhao, Qihui; Dai, Wenjian

    2015-01-01

    Activation of the silent mating type information regulation 2 homolog 1 (SIRT1) has been shown consistent antiinflammatory function. However, little information is available on the function of SIRT1 during Angiotensin II (AngII)-induced atherosclerosis. Here we report atheroprotective effects of sirt1 activation in a model of AngII-accelerated atherosclerosis, characterized by suppression pro-inflammatory transcription factors Nuclear transcription factor (NF)-κB and Signal Transducers and Activators of Transcription. (STAT) signaling pathway, and atherosclerotic lesion macrophage content. In this model, administration of the SIRT1 agonist SRT1720 substantially attenuated AngII-accelerated atherosclerosis with decreasing blood pressure and inhibited NF-κB and STAT3 activation, which was associated with suppression of inflammatory factor and atherogenic gene expression in the artery. In vitro studies demonstrated similar changes in AngII-treated VSMCs and macrophages: SIRT1 activation inhibited the expression levels of proinflammatory factor. These studies uncover crucial proinflammatory mechanisms of AngII and highlight actions of SIRT1 activation to inhibit AngII signaling, which is atheroprotective. - Highlights: • SRT1720 reduced atherosclerotic lesion size in aortic arches and atherosclerotic lesion macrophage content. • SRT1720 could inhibit the phosphorylation of STAT3 and p65 phosphorylation and translocation. • SRT1720 could inhibit the expression of proinflammatory factor.

  1. The Sirt1 activator SRT1720 attenuates angiotensin II-induced atherosclerosis in apoE{sup −/−} mice through inhibiting vascular inflammatory response

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yi xi; Zhang, Man; Cai, Yuehua; Zhao, Qihui; Dai, Wenjian, E-mail: wjdai@126.com

    2015-10-02

    Activation of the silent mating type information regulation 2 homolog 1 (SIRT1) has been shown consistent antiinflammatory function. However, little information is available on the function of SIRT1 during Angiotensin II (AngII)-induced atherosclerosis. Here we report atheroprotective effects of sirt1 activation in a model of AngII-accelerated atherosclerosis, characterized by suppression pro-inflammatory transcription factors Nuclear transcription factor (NF)-κB and Signal Transducers and Activators of Transcription. (STAT) signaling pathway, and atherosclerotic lesion macrophage content. In this model, administration of the SIRT1 agonist SRT1720 substantially attenuated AngII-accelerated atherosclerosis with decreasing blood pressure and inhibited NF-κB and STAT3 activation, which was associated with suppression of inflammatory factor and atherogenic gene expression in the artery. In vitro studies demonstrated similar changes in AngII-treated VSMCs and macrophages: SIRT1 activation inhibited the expression levels of proinflammatory factor. These studies uncover crucial proinflammatory mechanisms of AngII and highlight actions of SIRT1 activation to inhibit AngII signaling, which is atheroprotective. - Highlights: • SRT1720 reduced atherosclerotic lesion size in aortic arches and atherosclerotic lesion macrophage content. • SRT1720 could inhibit the phosphorylation of STAT3 and p65 phosphorylation and translocation. • SRT1720 could inhibit the expression of proinflammatory factor.

  2. Salidroside attenuates inflammatory responses by suppressing nuclear factor-κB and mitogen activated protein kinases activation in lipopolysaccharide-induced mastitis in mice.

    Science.gov (United States)

    Li, Depeng; Fu, Yunhe; Zhang, Wen; Su, Gaoli; Liu, Bo; Guo, Mengyao; Li, Fengyang; Liang, Dejie; Liu, Zhicheng; Zhang, Xichen; Cao, Yongguo; Zhang, Naisheng; Yang, Zhengtao

    2013-01-01

    Mastitis is defined as inflammation of the mammary gland in domestic dairy animals and humans. Salidroside, a major component isolated from Rhodiola rosea L., has potent anti-inflammatory properties, but whether it can be used in mastitis treatment has not yet been investigated. The aim of this study was to assess the protective effects of salidroside against lipopolysaccharide (LPS)-induced mastitis in mice and the mechanism of action. We used a mouse mastitis model in which mammary gland inflammation was induced by LPS challenge. Salidroside administered 1 h before LPS infusion significantly attenuated inflammatory cell infiltration, reduced the activity of myeloperoxidase in mammary tissue, and decreased the concentration of tumor necrosis factor-α, interleukin (IL)-1β, and IL-6 in a dose-dependent manner. Further studies revealed that salidroside down-regulated phosphorylation of LPS-induced nuclear transcription factor-kappaB (NF-κB) p65 and inhibitor of NF-κB α (IκBα) in the NF-κB signal pathway, and suppressed phosphorylation of p38, extracellular signal-regulated kinase (ERK) and c-jun NH(2)-terminal kinase (JNK) in MAPKs signal pathways. This study demonstrates that salidroside is an effective suppressor of inflammation and may be a candidate for the prophylaxis of mastitis.

  3. Ethanol extract of Cordyceps militaris grown on germinated soybeans attenuates dextran-sodium-sulfate- (DSS-) induced colitis by suppressing the expression of matrix metalloproteinases and inflammatory mediators.

    Science.gov (United States)

    Park, Dong Ki; Park, Hye-Jin

    2013-01-01

    The effect of Cordyceps militaris (CM) grown on germinated soybeans (GSC) in the inflammatory bowel disease (IBD) model was studied. To demonstrate the preventive effect of GSC extract in a dextran-sodium-sulfate- (DSS-) induced acute colitis mouse model, GSC was administered 2 days before DSS coadministration. GSC significantly suppressed DSS-induced disease activity index (DAI) as well as histopathological scores, compared to control or CM-treated group. To elucidate the anti-IBD activity of GSC, we checked the level of matrix metalloproteinases (MMPs) and inflammatory mediators. GSC extract decreased the level of MMP-3 and -9 mRNAs and p53 proteins. The level and activity of LPS-induced MMP-9 were reduced in GSC-treated RAW264.7 cells. It also attenuated the level of inducible nitric oxide synthase (iNOS) and tumor necrosis factor- (TNF-) α mRNAs both in colon tissue and in macrophage cells. These results suggest that GSC can be applied as a protective agent against IBDs.

  4. Phenotypic dysregulation of microglial activation in young offspring rats with maternal sleep deprivation-induced cognitive impairment.

    Science.gov (United States)

    Zhao, Qiuying; Xie, Xiaofang; Fan, Yonghua; Zhang, Jinqiang; Jiang, Wei; Wu, Xiaohui; Yan, Shuo; Chen, Yubo; Peng, Cheng; You, Zili

    2015-04-01

    Despite the potential adverse effects of maternal sleep deprivation (MSD) on physiological and behavioral aspects of offspring, the mechanisms remain poorly understood. The present study was intended to investigate the roles of microglia on neurodevelopment and cognition in young offspring rats with prenatal sleep deprivation. Pregnant Wistar rats received 72 h sleep deprivation in the last trimester of gestation, and their prepuberty male offspring were given the intraperitoneal injection with or without minocycline. The results showed the number of Iba1(+) microglia increased, that of hippocampal neurogenesis decreased, and the hippocampus-dependent spatial learning and memory were impaired in MSD offspring. The classical microglial activation markers (M1 phenotype) IL-1β, IL-6, TNF-α, CD68 and iNOS were increased, while the alternative microglial activation markers (M2 phenotype) Arg1, Ym1, IL-4, IL-10 and CD206 were reduced in hippocampus of MSD offspring. After minocycline administration, the MSD offspring showed improvement in MWM behaviors and increase in BrdU(+)/DCX(+) cells. Minocycline reduced Iba1(+) cells, suppressed the production of pro-inflammatory molecules, and reversed the reduction of M2 microglial markers in the MSD prepuberty offspring. These results indicate that dysregulation in microglial pro- and anti-inflammatory activation is involved in MSD-induced inhibition of neurogenesis and impairment of spatial learning and memory.

  5. 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...

  6. Methanol Extract of Artemisia apiacea Hance Attenuates the Expression of Inflammatory Mediators via NF-κB Inactivation

    Directory of Open Access Journals (Sweden)

    Ji Choul Ryu

    2013-01-01

    Full Text Available Artemisia apiacea Hance is one of the most widely used herbs for the treatment of malaria, jaundice, and dyspeptic complaint in oriental medicine. This study investigated the effects of methanol extracts of A. apiacea Hance (MEAH on the induction of inducible nitric oxide synthase (iNOS and proinflammatory mediators by lipopolysaccharide (LPS in Raw264.7 macrophage cells and also evaluated the in vivo effect of MEAH on carrageenan-induced paw edema in rats. MEAH treatment in Raw264.7 cells significantly decreased LPS-inducible nitric oxide production and the expression of iNOS in a concentration-dependent manner, while MEAH (up to 100 μg/mL had no cytotoxic activity. Results from immunoblot analyses and ELISA revealed that MEAH significantly inhibited the expression of cyclooxygenase-2, tumor necrosis factor-α, interleukin-1β, and interleukin-6 in LPS-activated cells. As a plausible molecular mechanism, increased degradation and phosphorylation of inhibitory-κBα and nuclear factor-κB accumulation in the nucleus by LPS were partly blocked by MEAH treatment. Finally, MEAH treatment decreased the carrageenan-induced formation of paw edema and infiltration of inflammatory cells in rats. These results demonstrate that MEAH has an anti-inflammatory therapeutic potential that may result from the inhibition of nuclear factor-κB activation, subsequently decreasing the expression of proinflammatory mediators.

  7. G protein-coupled receptor kinase-3-deficient mice exhibit WHIM syndrome features and attenuated inflammatory responses

    Science.gov (United States)

    Tarrant, Teresa K.; Billard, Matthew J.; Timoshchenko, Roman G.; McGinnis, Marcus W.; Serafin, D. Stephen; Foreman, Oded; Esserman, Denise A.; Chao, Nelson J.; Lento, William E.; Lee, David M.; Patel, Dhavalkumar; Siderovski, David P.

    2013-01-01

    Chemokine receptor interactions coordinate leukocyte migration in inflammation. Chemokine receptors are GPCRs that when activated, are phosphorylated by GRKs to turn off G protein-mediated signaling yet recruit additional signaling machinery. Recently, GRK3 was identified as a negative regulator of CXCL12/CXCR4 signaling that is defective in human WHIM syndrome. Here, we report that GRK3−/− mice exhibit numerous features of human WHIM, such as impaired CXCL12-mediated desensitization, enhanced CXCR4 signaling to ERK activation, altered granulocyte migration, and a mild myelokathexis. Moreover, GRK3−/− protects mice from two acute models of inflammatory arthritis (K/BxN serum transfer and CAIA). In these granulocyte-dependent disease models, protection of GRK3−/− mice is mediated by retention of cells in the marrow, fewer circulating granulocytes in the peripheral blood, and reduced granulocytes in the joints during active inflammation. In contrast to WHIM, GRK3−/− mice have minimal hypogammaglobulinemia and a peripheral leukocytosis with increased lymphocytes and absent neutropenia. Thus, we conclude that the loss of GRK3-mediated regulation of CXCL12/CXCR4 signaling contributes to some, but not all, of the complete WHIM phenotype and that GRK3 inhibition may be beneficial in the treatment of inflammatory arthritis. PMID:23935208

  8. Attenuation of stress induced memory deficits by nonsteroidal anti-inflammatory drugs (NSAIDs) in rats: Role of antioxidant enzymes.

    Science.gov (United States)

    Emad, Shaista; Qadeer, Sara; Sadaf, Sana; Batool, Zehra; Haider, Saida; Perveen, Tahira

    2017-04-01

    Repeated stress paradigms have been shown to cause devastating alterations on memory functions. Stress is linked with inflammation. Psychological and certain physical stressors could lead to neuroinflammation. Inflammatory process may occur by release of mediators and stimulate the production of prostaglandins through cyclooxygenase (COX). Treatment with COX inhibitors, which restrain prostaglandin production, has enhanced memory in a number of neuroinflammatory states showing a potential function for raised prostaglandins in these memory shortfalls. In the present study, potential therapeutic effects of indomethacin and diclofenac sodium on memory in both unrestraint and restraint rats were observed. Two components, long term memory and short term memory were examined by Morris water maze (MWM) and elevated plus maze (EPM) respectively. The present study also demonstrated the effect of nonsteroidal anti-inflammatory drugs (NSAIDs) on lipid peroxidation (LPO) and activities of antioxidant enzymes along with the activity of acetylcholinesterase (AChE). Results of MWM and EPM showed significant effects of drugs in both unrestraint and restraint rats as escape latency and transfer latency, in respective behavioral models were decreased as compared to that of control. This study also showed NSAIDs administration decreased LPO and increased antioxidant enzymes activity and decreased AChE activity in rats exposed to repeated stress. In conclusion this study suggests a therapeutic potential of indomethacin and diclofenac against repeated stress-induced memory deficits. Copyright © 2016. Published by Elsevier Urban & Partner Sp. z o.o.

  9. Nitric oxide-induced activation of the AMP-activated protein kinase α2 subunit attenuates IκB kinase activity and inflammatory responses in endothelial cells.

    Directory of Open Access Journals (Sweden)

    Elke Bess

    Full Text Available BACKGROUND: In endothelial cells, activation of the AMP-activated protein kinase (AMPK has been linked with anti-inflammatory actions but the events downstream of kinase activation are not well understood. Here, we addressed the effects of AMPK activation/deletion on the activation of NFκB and determined whether the AMPK could contribute to the anti-inflammatory actions of nitric oxide (NO. METHODOLOGY/PRINCIPAL FINDINGS: Overexpression of a dominant negative AMPKα2 mutant in tumor necrosis factor-α-stimulated human endothelial cells resulted in increased NFκB activity, E-selectin expression and monocyte adhesion. In endothelial cells from AMPKα2(-/- mice the interleukin (IL-1β induced expression of E-selectin was significantly increased. DETA-NO activated the AMPK and attenuated NFκB activation/E-selectin expression, effects not observed in human endothelial cells in the presence of the dominant negative AMPK, or in endothelial cells from AMPKα2(-/- mice. Mechanistically, overexpression of constitutively active AMPK decreased the phosphorylation of IκB and p65, indicating a link between AMPK and the IκB kinase (IKK. Indeed, IKK (more specifically residues Ser177 and Ser181 was found to be a direct substrate of AMPKα2 in vitro. The hyper-phosphorylation of the IKK, which is known to result in its inhibition, was also apparent in endothelial cells from AMPKα2(+/+ versus AMPKα2(-/- mice. CONCLUSIONS: These results demonstrate that the IKK is a direct substrate of AMPKα2 and that its phosphorylation on Ser177 and Ser181 results in the inhibition of the kinase and decreased NFκB activation. Moreover, as NO potently activates AMPK in endothelial cells, a portion of the anti-inflammatory effects of NO are mediated by AMPK.

  10. Alpinetin attenuates inflammatory responses by interfering toll-like receptor 4/nuclear factor kappa B signaling pathway in lipopolysaccharide-induced mastitis in mice.

    Science.gov (United States)

    Chen, Haijin; Mo, Xiaodong; Yu, Jinlong; Huang, Zonghai

    2013-09-01

    Alpinetin, a novel plant flavonoid derived from Alpinia katsumadai Hayata, has been reported to exhibit anti-inflammatory properties. However, the effect of alpinetin on mastitis has not been investigated. The aim of this study was to investigate the protective effect of alpinetin against lipopolysaccharide (LPS)-induced mastitis and to clarify the possible mechanism. In the present study, primary mouse mammary epithelial cells and an LPS-induced mouse mastitis model were used to investigate the effect of alpinetin on mastitis and the possible mechanism. In vivo, we observed that alpinetin significantly attenuated the infiltration of neutrophilic granulocytes, and the activation of myeloperoxidase; down-regulated the level of pro-inflammatory cytokines, including TNF-α, IL-1β and IL-6; inhibited the phosphorylation of IκB-α, NF-κB p65 and the expression of TLR4, caused by LPS. In vitro, we also observed that alpinetin inhibited the expression of TLR4 and the production of TNF-α, IL-1β and IL-6 in LPS-stimulated primary mouse mammary epithelial cells. However, alpinetin could not inhibit the production of IL-1β and IL-6 in TNF-α-stimulated primary mouse mammary epithelial cells. In conclusion, our results suggest that the anti-inflammatory effects of alpinetin against LPS-induced mastitis may be due to its ability to inhibit TLR4-mediated NF-κB signaling pathways. Alpinetin may be a promising potential therapeutic reagent for mastitis treatment. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Lignans From Forsythia x Intermedia Leaves and Flowers Attenuate the Pro-inflammatory Function of Leukocytes and Their Interaction With Endothelial Cells

    Directory of Open Access Journals (Sweden)

    Barbara Michalak

    2018-04-01

    Full Text Available Aim of the study: Taking into account that overactivated leukocytes are an important factor in the development of many chronic diseases, we investigated the activity of phytochemically characterized (HPLC-DAD-MSn extracts from forsythia leaves and flowers on the pro- and anti-inflammatory functions of leukocytes (effects on IL-1β, IL-8, TNF-α, and TGFβ release and their adherence to endothelial cells. Using bio-guided fractionation, we isolated the active compounds and determined their biological activity, and we included the positive control quercetin.Methods: The effect on IL-1β, TNF-α, IL-8, and TGF-α production by leukocytes was measured by enzyme-linked immunosorbent assay (ELISA. The surface expression of adhesion molecules was analyzed with flow cytometry, and the neutrophil attachment to the endothelial cells was assessed fluorimetrically. The effects on p38MAPK, ERK1/2 and JNK phosphorylation were determined using western blots.Results: Leaf extracts had the effect of decreasing TNF-α production in neutrophils and monocyte/macrophage cells. The bio-guided fractionation led to the isolation of the following lignan aglycones: (+-pinoresinol, (+-epipinoresinol, (−-matairesinol, (+-phillygenin, and (−-arctigenin. Only phillygenin was able to stimulate the anti-inflammatory function of macrophages by inducing TGF-β release and IL-10 receptor surface expression. Arctigenin, phillygenin, and a metabolite produced by the gut microbiota, enterolactone, decreased TNF-α and IL-1β production and neutrophil adhesion to endothelial cells, probably by attenuating the p38 and ERK kinase pathways.Conclusion:Forsythia x intermedia is a valuable source of active lignans, which may be potential candidates for treating inflammatory diseases that are associated with the excessive production of cytokines such as TNF-α and IL-1β.

  12. Suaeda japonica Makino Attenuates Lipopolysaccharide- Induced ...

    African Journals Online (AJOL)

    ... kappa-B (NF-êB)-dependent. Conclusion: Our findings imply that SJE may be a potential therapeutic agent in regulating microgliamediated neuroinflammatory responses observed in several neurodegenerative diseases. Keywords: Suaeda japonica, Antioxidant activity, Anti-inflammatory activity, Microglial Cells, iNOS, ...

  13. Cocaine-mediated induction of microglial activation involves the ER stress-TLR2 axis.

    Science.gov (United States)

    Liao, Ke; Guo, Minglei; Niu, Fang; Yang, Lu; Callen, Shannon E; Buch, Shilpa

    2016-02-09

    Neuroinflammation associated with advanced human immunodeficiency virus (HIV)-1 infection is often exacerbated by chronic cocaine abuse. Cocaine exposure has been demonstrated to mediate up-regulation of inflammatory mediators in in vitro cultures of microglia. The molecular mechanisms involved in this process, however, remain poorly understood. In this study, we sought to explore the underlying signaling pathways involved in cocaine-mediated activation of microglial cells. BV2 microglial cells were exposed to cocaine and assessed for toll-like receptor (TLR2) expression by quantitative polymerase chain reaction (qPCR), western blot, flow cytometry, and immunofluorescence staining. The mRNA and protein levels of cytokines (TNFα, IL-6, MCP-1) were detected by qPCR and ELISA, respectively; level of reactive oxygen species (ROS) production was examined by the Image-iT LIVE Green ROS detection kit; activation of endoplasmic reticulum (ER)-stress pathways were detected by western blot. Chromatin immunoprecipitation (ChIP) assay was employed to discern the binding of activating transcription factor 4 (ATF4) with the TLR2 promoter. Immunoprecipitation followed by western blotting with tyrosine antibody was used to determine phosphorylation of TLR2. Cocaine-mediated up-regulation of TLR2 expression and microglial activation was validated in cocaine-injected mice. Exposure of microglial cells to cocaine resulted in increased expression of TLR2 with a concomitant induction of microglial activation. Furthermore, this effect was mediated by NADPH oxidase-mediated rapid accumulation of ROS with downstream activation of the ER-stress pathways as evidenced by the fact that cocaine exposure led to up-regulation of pPERK/peIF2α/ATF4 and TLR2. The novel role of ATF4 in the regulation of TLR2 expression was confirmed using genetic and pharmacological approaches. xThe current study demonstrates that cocaine-mediated activation of microglia involves up-regulation of TLR2 through the

  14. 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

  15. Objectively measured physical activity and inflammatory markers among US adults with diabetes: implications for attenuating disease progression.

    Science.gov (United States)

    Loprinzi, Paul D; Ramulu, Pradeep Y

    2013-09-01

    To examine the association between objectively measured physical activity and markers of inflammation (ie, white blood cell count, neutrophil count, and C-reactive protein level) among a national sample of adults with diabetes. Data from the 2003-2006 National Health and Nutrition Examination Survey cycles were used. The data were evaluated from November 25, 2012, to May 3, 2013. Participants wore an accelerometer for 4 days or longer to assess physical activity, with blood samples obtained to assess the aforementioned inflammatory markers. Accelerometer-derived light physical activity and moderate to vigorous physical activity were inversely associated with white blood cell and neutrophil counts, whereas time spent in moderate to vigorous physical activity was inversely associated with C-reactive protein levels. Adults with diabetes engaging in more physical activity have lower degrees of inflammation, suggesting that physical activity may reduce disease progression through mitigating inflammation, which is an important finding because increased inflammation among those with diabetes can worsen disease progression, including diabetic end-organ damage. Copyright © 2013 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

  16. Polydatin attenuates d-galactose-induced liver and brain damage through its anti-oxidative, anti-inflammatory and anti-apoptotic effects in mice.

    Science.gov (United States)

    Xu, Lie-Qiang; Xie, You-Liang; Gui, Shu-Hua; Zhang, Xie; Mo, Zhi-Zhun; Sun, Chao-Yue; Li, Cai-Lan; Luo, Dan-Dan; Zhang, Zhen-Biao; Su, Zi-Ren; Xie, Jian-Hui

    2016-11-09

    Accumulating evidence has shown that chronic injection of d-galactose (d-gal) can mimic natural aging, with accompanying liver and brain injury. Oxidative stress and apoptosis play a vital role in the aging process. In this study, the antioxidant ability of polydatin (PD) was investigated using four established in vitro systems. An in vivo study was also conducted to investigate the possible protective effect of PD on d-gal-induced liver and brain damage. The results showed that PD had remarkable in vitro free radical scavenging activity on 2,2-diphenyl-1-picryl-hydrazyl (DPPH˙), 2,2'-azino-bis(3-ethylbenzo-thiazoline-6-sulfonic acid) (ABTS + ˙) radical ions, and hydroxyl and superoxide anions. Results in vivo indicated that, in a group treated with d-gal plus PD, PD remarkably decreased the depression of body weight and organ indexes, reduced the levels of the serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST), and alleviated alterations in liver and brain histopathology. PD also significantly decreased the level of MDA and elevated SOD, GSH-Px, CAT activity and T-AOC levels in the liver and brain. In addition, the levels of inflammatory mediators, such as TNF-α, IL-1β and IL-6 in serum were markedly reduced after PD treatment. Western blotting results revealed that PD treatment noticeably attenuated the d-gal-induced elevation of Bcl-2/Bax ratio and caspase-3 protein expression in liver and brain. Overall, our findings indicate that PD treatment could effectively attenuate d-gal-induced liver and brain damage, and the mechanism might be associated with decreasing the oxidative stress, inflammation and apoptosis caused by d-gal. PD holds good potential for further development into a promising pharmaceutical candidate for the treatment of age-associated diseases.

  17. Modulation of neuro-inflammatory condition, acetylcholinesterase and antioxidant levels by genistein attenuates diabetes associated cognitive decline in mice.

    Science.gov (United States)

    Rajput, Mithun Singh; Sarkar, Purnima Dey

    2017-04-25

    The association of diabetes and cognitive decline may indicate that high sugar level might be a risk factor for Alzheimer's disease. A collective term 'diabetes associated cognitive decline' (DACD) has been coined for the patients with type 2 diabetes mellitus showing decline in their cognitive function, especially weak episodic memory, cognitive inflexibility and poor psychomotor performance leading towards Alzheimer's disease. However, at present, no specific treatment exists for the prevention and/or treatment of DACD. Genistein, an isoflavone phytoestrogen, reveals neuroprotective effects in many experimental murine models, though its role on DACD with probable mechanistic approach has still been scope for research. The motive behind the present study is to investigate the outcome of genistein treatment against DACD in streptozotocin-induced diabetic mice with Morris water maze paradigm followed by open field trial to rule out the possibility of impairment in locomotor performance. Chronic (30 days) genistein treatment (2.5, 5.0 and 10.0 mg/kg, i.p. once daily) in diabetic mice significantly lowered hyperglycemia, recovered cognitive performance by affecting acetylcholinesterase activity and oxidative stress and ameliorated neuro-inflammatory condition by varying TNF-α, IL-1β and nitrite levels as impaired in diabetic mice. Thirty days treatment with vitamin C or metformin also improved diabetes-induced memory impairment and significantly dragged these biochemical parameters towards respective controls. Locomotor performance was not influenced by diabetic condition or any associated treatment. It is concluded that genistein supplementation might be a prospective therapeutic approach for the treatment and/or avoidance of diabetic linked learning and memory dysfunction. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. 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

  19. Ginkgo biloba extracts attenuate lipopolysaccharide-induced inflammatory responses in acute lung injury by inhibiting the COX-2 and NF-κB pathways.

    Science.gov (United States)

    Yao, Xin; Chen, Nan; Ma, Chun-Hua; Tao, Jing; Bao, Jian-An; Zong-Qi, Cheng; Chen, Zu-Tao; Miao, Li-Yan

    2015-01-01

    In the present study, we analyzed the role of Ginkgo biloba extract in lipopolysaccharide(LPS)-induced acute lung injury (ALI). ALI was induced in mice by intratracheal instillation of LPS. G. biloba extract (12 and 24 mg·kg(-1)) and dexamethasone (2 mg·kg(-1)), as a positive control, were given by i.p. injection. The cells in the bronchoalveolar lavage fluid (BALF) were counted. The degree of animal lung edema was evaluated by measuring the wet/dry weight ratio. The superoxidase dismutase (SOD) and myeloperoxidase (MPO) activities were assayed by SOD and MPO kits, respectively. The levels of inflammatory mediators, tumor necrosis factor-a, interleukin-1b, and interleukin-6, were assayed by enzyme-linked immunosorbent assay. Pathological changes of lung tissues were observed by H&E staining. The levels of NF-κB p65 and COX-2 expression were detected by Western blotting. Compared to the LPS group, the treatment with the G. biloba extract at 12 and 24 mg·kg(-1) markedly attenuated the inflammatory cell numbers in the BALF, decreased NF-κB p65 and COX-2 expression, and improved SOD activity, and inhibited MPO activity. The histological changes of the lungs were also significantly improved. The results indicated that G. biloba extract has a protective effect on LPS-induced acute lung injury in mice. The protective mechanism of G. biloba extract may be partly attributed to the inhibition of NF-κB p65 and COX-2 activation. Copyright © 2015 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

  20. S-Propargyl-cysteine (SPRC) attenuated lipopolysaccharide-induced inflammatory response in H9c2 cells involved in a hydrogen sulfide-dependent mechanism.

    Science.gov (United States)

    Pan, Li-Long; Liu, Xin-Hua; Gong, Qi-Hai; Zhu, Yi-Zhun

    2011-06-01

    The present study attempts to investigate the effects of S-propargyl-cysteine (SPRC), a sulfur-containing amino acid, on lipopolysaccharide (LPS)-induced inflammatory response in H9c2 cardiac myocytes. We found that SPRC prevented nuclear factor-κB (NF-κB) activation assessed by NF-κB p65 phosphorylation and IκBα degradation, suppressed LPS-induced extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation and intracellular reactive oxygen species (ROS) production. Furthermore, incubation of H9c2 cells with SPRC induced phosphorylation of Akt in a time- and concentration-dependent manner. In addition, SPRC attenuated LPS-induced mRNA and protein expression of tumor necrosis factor-α (TNF-α), and mRNA expression of intercellular adhesion molecule-1 (ICAM-1) and inducible nitric oxide synthase (iNOS). The effects of SPRC were abolished by cystathionine γ-lyase [CSE-an enzyme that synthesizes hydrogen sulfide (H(2)S)] inhibitor, DL: -propargylglycine (PAG), SPRC-induced Akt phosphorylation and TNF-α release was also abolished by the phosphoinositide 3-kinase (PI3K) inhibitor LY294002. Furthermore, SPRC also increased LPS-induced down-regulation expression of CSE and H(2)S level in H9c2 cells. PAG abolished SPRC-induced up-regulation of H(2)S level. Therefore, we concluded that SPRC produced an anti-inflammatory effect in LPS-stimulated H9c2 cells partly through the CSE/H(2)S pathway by impairing IκBα/NF-κB signaling and by activating PI3K/Akt signaling pathway.

  1. Passive therapy with humanized anti-staphylococcal enterotoxin B antibodies attenuates systemic inflammatory response and protects from lethal pneumonia caused by staphylococcal enterotoxin B-producing Staphylococcus aureus.

    Science.gov (United States)

    Karau, Melissa J; Tilahun, Mulualem E; Krogman, Ashton; Osborne, Barbara A; Goldsby, Richard A; David, Chella S; Mandrekar, Jayawant N; Patel, Robin; Rajagopalan, Govindarajan

    2017-10-03

    Drugs such as linezolid that inhibit bacterial protein synthesis may be beneficial in treating infections caused by toxigenic Staphylococcus aureus. As protein synthesis inhibitors have no effect on preformed toxins, neutralization of pathogenic exotoxins with anti-toxin antibodies may be beneficial in conjunction with antibacterial therapy. Herein, we evaluated the efficacy of human-mouse chimeric high-affinity neutralizing anti-staphylococcal enterotoxin B (SEB) antibodies in the treatment of experimental pneumonia caused by SEB-producing S. aureus. Since HLA class II transgenic mice mount a stronger systemic immune response following challenge with SEB and are more susceptible to SEB-induced lethal toxic shock than conventional mice strains, HLA-DR3 transgenic mice were used. Lethal pneumonia caused by SEB-producing S. aureus in HLA-DR3 transgenic mice was characterized by robust T cell activation and elevated systemic levels of several pro-inflammatory cytokines and chemokines. Prophylactic administration of a single dose of linezolid 30 min prior to the onset of infection attenuated the systemic inflammatory response and protected from mortality whereas linezolid administered 60 min after the onset of infection failed to confer significant protection. Human-mouse chimeric high-affinity neutralizing anti-SEB antibodies alone, but not polyclonal human IgG, mitigated this response and protected from death when administered immediately after initiation of infection. Further, anti-SEB antibodies as well as intact polyclonal human IgG, but not its Fab or Fc fragments, protected from lethal pneumonia when followed with linezolid therapy 60 min later. In conclusion, neutralization of superantigens with high-affinity antibodies may have beneficial effects in pneumonia.

  2. Benznidazole, the trypanocidal drug used for Chagas disease, induces hepatic NRF2 activation and attenuates the inflammatory response in a murine model of sepsis

    International Nuclear Information System (INIS)

    Lambertucci, Flavia; Motiño, Omar; Villar, Silvina; Rigalli, Juan Pablo; Luján Alvarez, María de; Catania, Viviana A; Martín-Sanz, Paloma; Carnovale, Cristina Ester; Quiroga, Ariel Darío; Francés, Daniel Eleazar; Ronco, María Teresa

    2017-01-01

    Molecular mechanisms on sepsis progression are linked to the imbalance between reactive oxygen species (ROS) production and cellular antioxidant capacity. Previous studies demonstrated that benznidazole (BZL), known for its antiparasitic action on Trypanosoma cruzi, has immunomodulatory effects, increasing survival in C57BL/6 mice in a model of polymicrobial sepsis induced by cecal ligation and puncture (CLP). The mechanism by which BZL inhibits inflammatory response in sepsis is poorly understood. Also, our group recently reported that BZL is able to activate the nuclear factor erytroide-derived 2-Like 2 (NRF2) in vitro. The aim of the present work was to delineate the beneficial role of BZL during sepsis, analyzing its effects on the cellular redox status and the possible link to the innate immunity receptor TLR4. Specifically, we analyzed the effect of BZL on Nrf2 regulation and TLR4 expression in liver of mice 24 hours post-CLP. BZL was able to induce NRF2 nuclear protein localization in CLP mice. Also, we found that protein kinase C (PKC) is involved in the NRF2 nuclear accumulation and induction of its target genes. In addition, BZL prompted a reduction in hepatic CLP-induced TLR4 protein membrane localization, evidencing its immunomodulatory effects. Together, our results demonstrate that BZL induces hepatic NRF2 activation with the concomitant increase in the antioxidant defenses, and the attenuation of inflammatory response, in part, by inhibiting TLR4 expression in a murine model of sepsis. - Highlights: • BZL improves survival rate after polymicrobial sepsis • BZL enhances hepatic NRF2 nuclear accumulation in a model of sepsis, in part, by a mechanism dependent on PKC activation • BZL-enhanced NRF2 induction regulates antioxidant enzymes and increases antioxidant cellular defenses in sepsis • BZL blocks liver ROS production and ROS-induced TLR4 plasma membrane expression in septic mice

  3. 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.

  4. APP Regulates Microglial Phenotype in a Mouse Model of Alzheimer's Disease

    Science.gov (United States)

    Manocha, Gunjan D.; Floden, Angela M.; Rausch, Keiko; Kulas, Joshua A.; McGregor, Brett A.; Rojanathammanee, Lalida; Puig, Kelley R.; Puig, Kendra L.; Karki, Sanjib; Nichols, Michael R.; Darland, Diane C.; Porter, James E.

    2016-01-01

    Prior work suggests that amyloid precursor protein (APP) can function as a proinflammatory receptor on immune cells, such as monocytes and microglia. Therefore, we hypothesized that APP serves this function in microglia during Alzheimer's disease. Although fibrillar amyloid β (Aβ)-stimulated cytokine secretion from both wild-type and APP knock-out (mAPP−/−) microglial cultures, oligomeric Aβ was unable to stimulate increased secretion from mAPP−/− cells. This was consistent with an ability of oligomeric Aβ to bind APP. Similarly, intracerebroventricular infusions of oligomeric Aβ produced less microgliosis in mAPP−/− mice compared with wild-type mice. The mAPP−/− mice crossed to an APP/PS1 transgenic mouse line demonstrated reduced microgliosis and cytokine levels and improved memory compared with wild-type mice despite robust fibrillar Aβ plaque deposition. These data define a novel function for microglial APP in regulating their ability to acquire a proinflammatory phenotype during disease. SIGNIFICANCE STATEMENT A hallmark of Alzheimer's disease (AD) brains is the accumulation of amyloid β (Aβ) peptide within plaques robustly invested with reactive microglia. This supports the notion that Aβ stimulation of microglial activation is one source of brain inflammatory changes during disease. Aβ is a cleavage product of the ubiquitously expressed amyloid precursor protein (APP) and is able to self-associate into a wide variety of differently sized and structurally distinct multimers. In this study, we demonstrate both in vitro and in vivo that nonfibrillar, oligomeric forms of Aβ are able to interact with the parent APP protein to stimulate microglial activation. This provides a mechanism by which metabolism of APP results in possible autocrine or paracrine Aβ production to drive the microgliosis associated with AD brains. PMID:27511018

  5. 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.

  6. 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.

  7. SCM-198 attenuates early atherosclerotic lesions in hypercholesterolemic rabbits via modulation of the inflammatory and oxidative stress pathways.

    Science.gov (United States)

    Zhang, Yanfei; Guo, Wei; Wen, Yadan; Xiong, Qinghui; Liu, Hongrui; Wu, Jian; Zou, Yunzeng; Zhu, Yizhun

    2012-09-01

    GPx in the aorta. In a rabbit atherosclerotic model, SCM-198 dose-dependently ameliorated the progression of atherosclerotic lesions and vascular dysfunction accompanied by the suppression of inflammatory factors and oxidative stress. These findings suggested that SCM-198 might be a potential agent for the treatment of atherosclerosis. Crown Copyright © 2012. Published by Elsevier Ireland Ltd. All rights reserved.

  8. Therapeutic targeting of Krüppel-like factor 4 abrogates microglial activation

    Directory of Open Access Journals (Sweden)

    Kaushik Deepak

    2012-03-01

    Full Text Available Abstract Background Neuroinflammation occurs as a result of microglial activation in response to invading micro-organisms or other inflammatory stimuli within the central nervous system. According to our earlier findings, Krüppel-like factor 4 (Klf4, a zinc finger transcription factor, is involved in microglial activation and subsequent release of proinflammatory cytokines, tumor necrosis factor alpha, macrophage chemoattractant protein-1 and interleukin-6 as well as proinflammatory enzymes, inducible nitric oxide synthase and cyclooxygenase-2 in lipopolysaccharide-treated microglial cells. Our current study focuses on finding the molecular mechanism of the anti-inflammatory activities of honokiol in lipopolysaccharide-treated microglia with emphasis on the regulation of Klf4. Methods For in vitro studies, mouse microglial BV-2 cell lines as well as primary microglia were treated with 500 ng/mL lipopolysaccharide as well as 1 μM and 10 μM of honokiol. We cloned full-length Klf4 cDNA in pcDNA3.1 expression vector and transfected BV-2 cells with this construct using lipofectamine for overexpression studies. For in vivo studies, brain tissues were isolated from BALB/c mice treated with 5 mg/kg body weight of lipopolysaccharide either with or without 2.5 or 5 mg/kg body weight of honokiol. Expression of Klf4, cyclooxygenase-2, inducible nitric oxide synthase and phospho-nuclear factor-kappa B was measured using immunoblotting. We also measured the levels of cytokines, reactive oxygen species and nitric oxide in different conditions. Results Our findings suggest that honokiol can substantially downregulate the production of proinflammatory cytokines and inflammatory enzymes in lipopolysaccharide-stimulated microglia. In addition, honokiol downregulates lipopolysaccharide-induced upregulation of both Klf4 and phospho-nuclear factor-kappa B in these cells. We also found that overexpression of Klf4 in BV-2 cells suppresses the anti-inflammatory

  9. 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.

  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. Exogenous heat shock cognate protein 70 pretreatment attenuates cardiac and hepatic dysfunction with associated anti-inflammatory responses in experimental septic shock.

    Science.gov (United States)

    Hsu, Jong-Hau; Yang, Rei-Cheng; Lin, Shih-Jen; Liou, Shu-Fen; Dai, Zen-Kong; Yeh, Jwu-Lai; Wu, Jiunn-Ren

    2014-12-01

    It has been recently demonstrated that intracellular heat shock cognate protein 70 (HSC70) can be released into extracellular space with physiologic effects. However, its extracellular function in sepsis is not clear. In this study, we hypothesize that extracellular HSC70 can protect against lipopolysaccharide (LPS)-induced myocardial and hepatic dysfunction because of its anti-inflammatory actions. In Wistar rats, septic shock developed with hypotension, tachycardia, and myocardial and hepatic dysfunction at 4 h following LPS administration (10 mg/kg, i.v.). Pretreatment with recombinant bovine HSC70 (20 μg/kg, i.v.) attenuated LPS-induced hypotension and tachycardia by 21% and 23%, respectively (P shock cognate protein 70 also prevented LPS-induced hypoglycemia (217 vs. 59 mg/dL, P shock, extracellular HSC70 conveys pleiotropic protection on myocardial, hepatic, and systemic derangements, with associated inhibition of proinflammatory mediators including tumor necrosis factor α, nitric oxide, cyclooxygenase 2, and matrix metalloproteinase 9, through mitogen-activated protein kinase/nuclear factor κB signaling pathways. Therefore, extracellular HSC70 may have a promising role in the prophylactic treatment of sepsis.

  12. Baicalein attenuates inflammatory responses by suppressing TLR4 mediated NF-κB and MAPK signaling pathways in LPS-induced mastitis in mice.

    Science.gov (United States)

    He, Xuexiu; Wei, Zhengkai; Zhou, Ershun; Chen, Libin; Kou, Jinhua; Wang, Jingjing; Yang, Zhengtao

    2015-09-01

    Baicalein is a phenolic flavonoid presented in the dry roots of Scutellaria baicalensis Georgi. It has been reported that baicalein possesses a number of biological properties, such as antiviral, antioxidative, anti-inflammatory, antithrombotic, and anticancer properties. However, the effect of baicalein on mastitis has not yet been reported. This research aims to detect the effect of baicalein on lipopolysaccharide (LPS)-induced mastitis in mice and to investigate the molecular mechanisms. Baicalein was administered intraperitoneally 1h before and 12h after LPS treatment. The results indicated that baicalein treatment markedly attenuated the damage of the mammary gland induced by LPS, suppressed the activity of myeloperoxidase (MPO) and the levels of tumor necrosis factor (TNF-α) and interleukin (IL-1β) in mice with LPS-induced mastitis. Besides, baicalein blocked the expression of Toll-like receptor 4 (TLR4) and then suppressed the phosphorylation of nuclear transcription factor-kappaB (NF-κB) p65 and degradation inhibitor of NF-κBα (IκBα) and, and inhibited the phosphorylation of p38, extracellular signal-regulated kinase (ERK) and c-jun NH2-terminal kinase (JNK) in mitogen-activated protein kinase (MAPK) signal pathway. These findings suggested that baicalein may have a potential prospect against mastitis. Copyright © 2015. Published by Elsevier B.V.

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

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    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.

  14. Microglial neuroinflammation contributes to tau accumulation in chronic traumatic encephalopathy.

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    Cherry, Jonathan D; Tripodis, Yorghos; Alvarez, Victor E; Huber, Bertrand; Kiernan, Patrick T; Daneshvar, Daniel H; Mez, Jesse; Montenigro, Philip H; Solomon, Todd M; Alosco, Michael L; Stern, Robert A; McKee, Ann C; Stein, Thor D

    2016-10-28

    The chronic effects of repetitive head impacts (RHI) on the development of neuroinflammation and its relationship to chronic traumatic encephalopathy (CTE) are unknown. Here we set out to determine the relationship between RHI exposure, neuroinflammation, and the development of hyperphosphorylated tau (ptau) pathology and dementia risk in CTE. We studied a cohort of 66 deceased American football athletes from the Boston University-Veteran's Affairs-Concussion Legacy Foundation Brain Bank as well as 16 non-athlete controls. Subjects with a neurodegenerative disease other than CTE were excluded. Counts of total and activated microglia, astrocytes, and ptau pathology were performed in the dorsolateral frontal cortex (DLF). Binary logistic and simultaneous equation regression models were used to test associations between RHI exposure, microglia, ptau pathology, and dementia. Duration of RHI exposure and the development and severity of CTE were associated with reactive microglial morphology and increased numbers of CD68 immunoreactive microglia in the DLF. A simultaneous equation regression model demonstrated that RHI exposure had a significant direct effect on CD68 cell density (p CTE. Inflammatory molecules may be important diagnostic or predictive biomarkers as well as promising therapeutic targets in CTE.

  15. Inhibition of Src kinase activity attenuates amyloid associated microgliosis in a murine model of Alzheimer’s disease

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    Dhawan Gunjan

    2012-07-01

    Full Text Available Abstract Background Microglial activation is an important histologic characteristic of the pathology of Alzheimer’s disease (AD. One hypothesis is that amyloid beta (Aβ peptide serves as a specific stimulus for tyrosine kinase-based microglial activation leading to pro-inflammatory changes that contribute to disease. Therefore, inhibiting Aβ stimulation of microglia may prove to be an important therapeutic strategy for AD. Methods Primary murine microglia cultures and the murine microglia cell line, BV2, were used for stimulation with fibrillar Aβ1-42. The non-receptor tyrosine kinase inhibitor, dasatinib, was used to treat the cells to determine whether Src family kinase activity was required for the Aβ stimulated signaling response and subsequent increase in TNFα secretion using Western blot analysis and enzyme-linked immunosorbent assay (ELISA, respectively. A histologic longitudinal analysis was performed using an AD transgenic mouse model, APP/PS1, to determine an age at which microglial protein tyrosine kinase levels increased in order to administer dasatinib via mini osmotic pump diffusion. Effects of dasatinib administration on microglial and astroglial activation, protein phosphotyrosine levels, active Src kinase levels, Aβ plaque deposition, and spatial working memory were assessed via immunohistochemistry, Western blot, and T maze analysis. Results Aβ fibrils stimulated primary murine microglia via a tyrosine kinase pathway involving Src kinase that was attenuated by dasatinib. Dasatinib administration to APP/PS1 mice decreased protein phosphotyrosine, active Src, reactive microglia, and TNFα levels in the hippocampus and temporal cortex. The drug had no effect on GFAP levels, Aβ plaque load, or the related tyrosine kinase, Lyn. These anti-inflammatory changes correlated with improved performance on the T maze test in dasatinib infused animals compared to control animals. Conclusions These data suggest that amyloid

  16. Tissue plasminogen activator induces microglial inflammation via a noncatalytic molecular mechanism involving activation of mitogen-activated protein kinases and Akt signaling pathways and AnnexinA2 and Galectin-1 receptors.

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    Pineda, David; Ampurdanés, Coral; Medina, Manel G; Serratosa, Joan; Tusell, Josep Maria; Saura, Josep; Planas, Anna M; Navarro, Pilar

    2012-04-01

    Inflammatory responses mediated by glial cells play a critical role in many pathological situations related to neurodegeneration such as Alzheimer's disease. Tissue plasminogen activator (tPA) is a serine protease which best-known function is fibrinolysis, but it is also involved in many other physiological and pathological events as microglial activation. Here, we found that tPA is required for Aβ-mediated microglial inflammatory response and tumor necrosis factor-α release. We further investigated the molecular mechanism responsible for tPA-mediated microglial activation. We found that tPA induces a catalytic-independent rapid and sustained activation of extracellular signal-regulated kinase (ERK)1/2, Jun N-terminal kinase (JNK), Akt, and p38 signaling pathways. Inhibition of ERK1/2 and JNK resulted in a strong inhibition of microglial activation, whereas Akt inhibition led to increased inflammatory response, suggesting specific functions for each signaling pathway in the regulation of microglial activation. Furthermore, we demonstrated that AnnexinA2 and Galectin-1 receptors are involved in tPA signaling and inflammatory response in glial cells. This study provides new evidences supporting that tPA plays a cytokine-like role in glial activation by triggering receptor-mediated intracellular signaling circuits and opens new therapeutic strategies for the treatment of neurological disorders in which neuroinflammation plays a pathogenic role. Copyright © 2011 Wiley-Liss, Inc.

  17. Donepezil improves learning and memory deficits in APP/PS1 mice by inhibition of microglial activation.

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    Guo, H B; Cheng, Y F; Wu, J G; Wang, C M; Wang, H T; Zhang, C; Qiu, Z K; Xu, J P

    2015-04-02

    Donepezil, a cholinesterase inhibitor, is a representative symptomatic therapy for Alzheimer's disease (AD). Recent studies have reported the anti-inflammatory effects of donepezil. However, limited studies that investigate its anti-inflammatory effect in AD have been reported. Considering the role of proinflammatory molecules and microglial activation in the pathogenesis of AD, the current study aimed to elucidate the effects of donepezil on microglial activation induced by amyloid deposition in transgenic mice. Our results showed that chronic treatment with donepezil significantly improved the cognitive function in the novel object recognition test and Morris water maze test in amyloid precursor protein (APP)/presenilin-1 (PS1) transgenic mice. We further demonstrated that these cognitive enhancements were related to the anti-inflammatory effect of donepezil. We found that donepezil could inhibit the expression of CD68, a specific marker of microglial activation, and reduce the release of proinflammatory cytokines including tumor necrosis factor-α and interleukin-1β. Immunohistochemistry and Congo red co-staining revealed that congophilic amyloid and activated microglia around plaques were also reduced by donepezil treatment. Enzyme-linked immunosorbent assay (ELISA) analysis showed that donepezil decreased insoluble Aβ40/Aβ42 and soluble Aβ40 levels. Moreover, donepezil reversed the impaired expression of insulin-degrading enzyme in the hippocampus of APP/PS1 mice. Our findings indicated that donepezil improves cognitive deficits in APP/PS1 mice by a mechanism that may be associated with its inhibition of microglial activation and release of proinflammatory cytokines. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

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

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    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.

  19. 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.

  20. Inhibition of microglial activation by elderberry extracts and its phenolic components

    Science.gov (United States)

    Simonyi, Agnes; Chen, Zihong; Jiang, Jinghua; Zong, Yijia; Chuang, Dennis Y.; Gu, Zezong; Lu, Chi-Hua; Fritsche, Kevin L.; Greenlief, C. Michael; Rottinghaus, George E.; Thomas, Andrew L.; Lubahn, Dennis B.; Sun, Grace Y.

    2015-01-01

    Aims Elderberry (Sambucus spp.) is one of the oldest medicinal plants noted for its cardiovascular, anti-inflammatory, and immune-stimulatory properties. In this study, we investigated the anti-inflammatory and anti-oxidant effects of the American elderberry (Sambucus nigra subsp. canadensis) pomace as well as some of the anthocyanins (cyanidin chloride and cyanidin 3-O-glucoside) and flavonols (quercetin and rutin) in bv-2 mouse microglial cells. Main methods The bv-2 cells were pretreated with elderberry pomace (extracted with ethanol or ethyl acetate) or its anthocyanins and flavonols and stimulated by either lipopolysaccharide (LPS) or interferon-γ (IFNγ). Reactive oxygen species (ROS) and nitric oxide (NO) production (indicating oxidative stress and inflammatory response) were measured using the ROS detection reagent DCF-DA and the Griess reaction, respectively. Key findings Analysis of total monomeric anthocyanin (as cyanidin 3-O-glucoside equivalents) indicated five-fold higher amount in the freeze-dried ethanol extract as compared to that of the oven-dried extract; anthocyanin was not detected in the ethyl acetate extracts. Elderberry ethanol extracts (freeze-dried or oven-dried) showed higher anti-oxidant activities and better ability to inhibit LPS or IFNγ-induced NO production as compared with the ethyl acetate extracts. The phenolic compounds strongly inhibited LPS or IFNγ-induced ROS production, but except for quercetin, they were relatively poor in inhibiting NO production. Significance These results demonstrated difference in anti-oxidative and anti-inflammatory effects of elderberry extracts depending on solvents used. Results further identified quercetin as the most active component in suppressing oxidative stress and inflammatory responses on microglial cells. PMID:25744406

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

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    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

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

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    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

  3. 12-oxo-phytodienoic acid, a plant-derived oxylipin, attenuates lipopolysaccharide-induced inflammation in microglia

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    Taki-Nakano, Nozomi; Kotera, Jun; Ohta, Hiroyuki

    2016-01-01

    Jasmonates are plant lipid–derived oxylipins that act as key signaling compounds in plant immunity, germination, and development. Although some physiological activities of natural jasmonates in mammalian cells have been investigated, their anti-inflammatory actions in mammalian cells remain unclear. Here, we investigated whether jasmonates protect mouse microglial MG5 cells against lipopolysaccharide (LPS)–induced inflammation. Among the jasmonates tested, only 12-oxo-phytodienoic acid (OPDA) suppressed LPS-induced expression of the typical inflammatory cytokines interleukin-6 and tumor necrosis factor α. In addition, only OPDA reduced LPS-induced nitric oxide production through a decrease in the level of inducible nitric oxide synthase. Further mechanistic studies showed that OPDA suppressed neuroinflammation by inhibiting nuclear factor κB and p38 mitogen-activated protein kinase signaling in LPS-activated MG5 cells. In addition, OPDA induced expression of suppressor of cytokine signaling-1 (SOCS-1), a negative regulator of inflammation, in MG5 cells. Finally, we found that the nuclear factor erythroid 2-related factor 2 signaling cascade induced by OPDA is not involved in the anti-inflammatory effects of OPDA. These results demonstrate that OPDA inhibited LPS-induced cell inflammation in mouse microglial cells via multiple pathways, including suppression of nuclear factor κB, inhibition of p38, and activation of SOCS-1 signaling. -- Highlights: •OPDA attenuates LPS-induced inflammatory cytokines such as IL-6 and TNF-α. •OPDA reduces LPS-induced iNOS expression and NO production. •OPDA suppresses NF-κB and p38 pathways and activates SOCS-1 signaling.

  4. 12-oxo-phytodienoic acid, a plant-derived oxylipin, attenuates lipopolysaccharide-induced inflammation in microglia

    Energy Technology Data Exchange (ETDEWEB)

    Taki-Nakano, Nozomi [Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259-B-65 Nagatsuta-cho, Midori-ku, Yokohama 226-8501 (Japan); Advanced Drug Research Laboratories, Sohyaku. Innovative Research Division, Mitsubishi Tanabe Pharma Corporation, 2-2-50, Kawagishi, Toda, Saitama 335-8505 (Japan); Kotera, Jun [Advanced Drug Research Laboratories, Sohyaku. Innovative Research Division, Mitsubishi Tanabe Pharma Corporation, 2-2-50, Kawagishi, Toda, Saitama 335-8505 (Japan); Ohta, Hiroyuki, E-mail: ohta.h.ab@m.titech.ac.jp [Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259-B-65 Nagatsuta-cho, Midori-ku, Yokohama 226-8501 (Japan); School of Life Science and Technology, Tokyo Institute of Technology, 4259-B-65 Nagatsuta-cho, Midori-ku, Yokohama 226-8501 (Japan)

    2016-05-13

    Jasmonates are plant lipid–derived oxylipins that act as key signaling compounds in plant immunity, germination, and development. Although some physiological activities of natural jasmonates in mammalian cells have been investigated, their anti-inflammatory actions in mammalian cells remain unclear. Here, we investigated whether jasmonates protect mouse microglial MG5 cells against lipopolysaccharide (LPS)–induced inflammation. Among the jasmonates tested, only 12-oxo-phytodienoic acid (OPDA) suppressed LPS-induced expression of the typical inflammatory cytokines interleukin-6 and tumor necrosis factor α. In addition, only OPDA reduced LPS-induced nitric oxide production through a decrease in the level of inducible nitric oxide synthase. Further mechanistic studies showed that OPDA suppressed neuroinflammation by inhibiting nuclear factor κB and p38 mitogen-activated protein kinase signaling in LPS-activated MG5 cells. In addition, OPDA induced expression of suppressor of cytokine signaling-1 (SOCS-1), a negative regulator of inflammation, in MG5 cells. Finally, we found that the nuclear factor erythroid 2-related factor 2 signaling cascade induced by OPDA is not involved in the anti-inflammatory effects of OPDA. These results demonstrate that OPDA inhibited LPS-induced cell inflammation in mouse microglial cells via multiple pathways, including suppression of nuclear factor κB, inhibition of p38, and activation of SOCS-1 signaling. -- Highlights: •OPDA attenuates LPS-induced inflammatory cytokines such as IL-6 and TNF-α. •OPDA reduces LPS-induced iNOS expression and NO production. •OPDA suppresses NF-κB and p38 pathways and activates SOCS-1 signaling.

  5. Blue Light Modulates Murine Microglial Gene Expression in the Absence of Optogenetic Protein Expression.

    Science.gov (United States)

    Cheng, Kevin P; Kiernan, Elizabeth A; Eliceiri, Kevin W; Williams, Justin C; Watters, Jyoti J

    2016-02-17

    Neural optogenetic applications over the past decade have steadily increased; however the effects of commonly used blue light paradigms on surrounding, non-optogenetic protein-expressing CNS cells are rarely considered, despite their simultaneous exposure. Here we report that blue light (450 nm) repetitively delivered in both long-duration boluses and rapid optogenetic bursts gene-specifically altered basal expression of inflammatory and neurotrophic genes in immortalized and primary murine wild type microglial cultures. In addition, blue light reduced pro-inflammatory gene expression in microglia activated with lipopolysaccharide. These results demonstrate previously unreported, off-target effects of blue light in cells not expressing optogenetic constructs. The unexpected gene modulatory effects of blue light on wild type CNS resident immune cells have novel and important implications for the neuro-optogenetic field. Further studies are needed to elucidate the molecular mechanisms and potential therapeutic utility of blue light modulation of the wild type CNS.

  6. Blue Light Modulates Murine Microglial Gene Expression in the Absence of Optogenetic Protein Expression

    Science.gov (United States)

    Cheng, Kevin P.; Kiernan, Elizabeth A.; Eliceiri, Kevin W.; Williams, Justin C.; Watters, Jyoti J.

    2016-01-01

    Neural optogenetic applications over the past decade have steadily increased; however the effects of commonly used blue light paradigms on surrounding, non-optogenetic protein-expressing CNS cells are rarely considered, despite their simultaneous exposure. Here we report that blue light (450 nm) repetitively delivered in both long-duration boluses and rapid optogenetic bursts gene-specifically altered basal expression of inflammatory and neurotrophic genes in immortalized and primary murine wild type microglial cultures. In addition, blue light reduced pro-inflammatory gene expression in microglia activated with lipopolysaccharide. These results demonstrate previously unreported, off-target effects of blue light in cells not expressing optogenetic constructs. The unexpected gene modulatory effects of blue light on wild type CNS resident immune cells have novel and important implications for the neuro-optogenetic field. Further studies are needed to elucidate the molecular mechanisms and potential therapeutic utility of blue light modulation of the wild type CNS. PMID:26883795

  7. Dual RNA sequencing reveals the expression of unique transcriptomic signatures in lipopolysaccharide-induced BV-2 microglial cells.

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    Amitabh Das

    Full Text Available Microglial cells become rapidly activated through interactions with pathogens, and the persistent activation of these cells is associated with various neurodegenerative diseases. Previous studies have investigated the transcriptomic signatures in microglia or macrophages using microarray technologies. However, this method has numerous restrictions, such as spatial biases, uneven probe properties, low sensitivity, and dependency on the probes spotted. To overcome this limitation and identify novel transcribed genes in response to LPS, we used RNA Sequencing (RNA-Seq to determine the novel transcriptomic signatures in BV-2 microglial cells. Sequencing assessment and quality evaluation showed that approximately 263 and 319 genes (≥ 1.5 log2-fold, such as cytokines and chemokines, were strongly induced after 2 and 4 h, respectively, and the induction of several genes with unknown immunological functions was also observed. Importantly, we observed that previously unidentified transcription factors (TFs (irf1, irf7, and irf9, histone demethylases (kdm4a and DNA methyltransferases (dnmt3l were significantly and selectively expressed in BV-2 microglial cells. The gene expression levels, transcription start sites (TSS, isoforms, and differential promoter usage revealed a complex pattern of transcriptional and post-transcriptional gene regulation upon infection with LPS. In addition, gene ontology, molecular networks and pathway analyses identified the top significantly regulated functional classification, canonical pathways and network functions at each activation status. Moreover, we further analyzed differentially expressed genes to identify transcription factor (TF motifs (-950 to +50 bp of the 5' upstream promoters and epigenetic mechanisms. Furthermore, we confirmed that the expressions of key inflammatory genes as well as pro-inflammatory mediators in the supernatants were significantly induced in LPS treated primary microglial cells. This

  8. Characterization of Macrophage/Microglial Activation and Effect of Photobiomodulation in the Spared Nerve Injury Model of Neuropathic Pain.

    Science.gov (United States)

    Kobiela Ketz, Ann; Byrnes, Kimberly R; Grunberg, Neil E; Kasper, Christine E; Osborne, Lisa; Pryor, Brian; Tosini, Nicholas L; Wu, Xingjia; Anders, Juanita J

    2017-05-01

    Neuropathic pain is common and debilitating with limited effective treatments. Macrophage/microglial activation along ascending somatosensory pathways following peripheral nerve injury facilitates neuropathic pain. However, polarization of macrophages/microglia in neuropathic pain is not well understood. Photobiomodulation treatment has been used to decrease neuropathic pain, has anti-inflammatory effects in spinal injury and wound healing models, and modulates microglial polarization in vitro. Our aim was to characterize macrophage/microglia response after peripheral nerve injury and modulate the response with photobiomodulation. Adult male Sprague-Dawley rats were randomly assigned to sham (N = 13), spared nerve injury (N = 13), or injury + photobiomodulation treatment groups (N = 7). Mechanical hypersensitivity was assessed with electronic von Frey. Photobiomodulation (980 nm) was applied to affected hind paw (output power 1 W, 20 s, 41cm above skin, power density 43.25 mW/cm 2 , dose 20 J), dorsal root ganglia (output power 4.5W, 19s, in skin contact, power density 43.25 mW/cm 2 , dose 85.5 J), and spinal cord regions (output power 1.5 W, 19s, in skin contact, power density 43.25 mW/cm 2 , dose 28.5 J) every other day from day 7-30 post-operatively. Immunohistochemistry characterized macrophage/microglial activation. Injured groups demonstrated mechanical hypersensitivity 1-30 days post-operatively. Photobiomodulation-treated animals began to recover after two treatments; at day 26, mechanical sensitivity reached baseline. Peripheral nerve injury caused region-specific macrophages/microglia activation along spinothalamic and dorsal-column medial lemniscus pathways. A pro-inflammatory microglial marker was expressed in the spinal cord of injured rats compared to photobiomodulation-treated and sham group. Photobiomodulation-treated dorsal root ganglion macrophages expressed anti-inflammatory markers. Photobiomodulation effectively reduced

  9. N(6)-(2-Hydroxyethyl)adenosine in the Medicinal Mushroom Cordyceps cicadae Attenuates Lipopolysaccharide-Stimulated Pro-inflammatory Responses by Suppressing TLR4-Mediated NF-κB Signaling Pathways.

    Science.gov (United States)

    Lu, Meng-Ying; Chen, Chin-Chu; Lee, Li-Ya; Lin, Ting-Wei; Kuo, Chia-Feng

    2015-10-23

    Natural products play an important role in promoting health with relation to the prevention of chronic inflammation. N(6)-(2-Hydroxyethyl)adenosine (HEA), a physiologically active compound in the medicinal mushroom Cordyceps cicadae, has been identified as a Ca(2+) antagonist and shown to control circulation and possess sedative activity in pharmacological tests. The fruiting body of C. cicadae has been widely applied in Chinese medicine. However, neither the anti-inflammatory activities of HEA nor the fruiting bodies of C. cicadae have been carefully examined. In this study, we first cultured the fruiting bodies of C. cicadae and then investigated the anti-inflammatory activities of water and methanol extracts of wild and artificially cultured C. cicadae fruiting bodies. Next, we determined the amount of three bioactive compounds, adenosine, cordycepin, and HEA, in the extracts and evaluated their synergistic anti-inflammatory effects. Moreover, the possible mechanism involved in anti-inflammatory action of HEA isolated from C. cicadae was investigated. The results indicate that cordycepin is more potent than adenosine and HEA in suppressing the lipopolysaccharide (LPS)-stimulated release of pro-inflammatory cytokines by RAW 264.7 macrophages; however, no synergistic effect was observed with these three compounds. HEA attenuated the LPS-induced pro-inflammatory responses by suppressing the toll-like receptor (TLR)4-mediated nuclear factor-κB (NF-κB) signaling pathway. This result will support the use of HEA as an anti-inflammatory agent and C. cicadae fruiting bodies as an anti-inflammatory mushroom.

  10. 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.

  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. Consumption of dairy yogurt with the polysaccharide rhamnogalacturonan from the peel of the Korean citrus hallabong enhances immune function and attenuates the inflammatory response.

    Science.gov (United States)

    Lee, Mi-Hyang; Kim, Minjoo; Kim, Minkyung; Kwak, Jung Hyun; Chang, Dong Hoon; Yu, Won Kyu; Lee, Sang-Hyun; Lee, Jong Ho

    2016-06-15

    The aim of this study was to investigate the impact of consuming dairy yogurt supplemented with rhamnogalacturonan (RG), a polysaccharide from the peel of the Korean citrus hallabong, on natural killer (NK) cell activity and circulating cytokine levels. A randomized, double-blind, placebo-controlled study was conducted on 120 nondiabetic and nonobese subjects. Over an eight-week period, the test group consumed one pack (150 mL) of dairy yogurt containing 50 mg of probiotics and 100 mg of hallabong peel polysaccharide (60% RG) each day, whereas the placebo group consumed the same product without the hallabong peel supplement. NK cell activity (%) was measured based on the ratios of the effector cells (E; peripheral blood mononuclear cells, PBMCs) from each participant relative to the target cells (T; K562 cells) at E : T ratios of 10 : 1, 5 : 1, 2.5 : 1, or 1.25 : 1. NK cell activities under all assay conditions and interleukin (IL)-12 and interferon (IFN)-γ levels were significantly increased in the test group at eight weeks compared to the baseline values, whereas the placebo group showed a significant increase only in NK cell activity at E : T = 1.25 : 1. The test group had significantly greater increases in the changes in serum NK cell activity at the E : T ratios of 10 : 1, 5 : 1, and 2.5 : 1 and in the increases in IL-12 and IFN-γ levels than were observed in the placebo group, after adjusting for baseline values. After eight weeks of treatment, significant reductions were found in IL-6 and IL-1β levels in both the placebo and test groups. The daily consumption of dairy yogurt supplemented with RG, a polysaccharide from the peel of the Korean citrus hallabong, enhanced NK cell function and attenuated pro-inflammatory cytokine levels (ClinicalTrials.gov: NCT02535663).

  13. Comparison of the Expression Changes after Botulinum Toxin Type A and Minocycline Administration in Lipopolysaccharide-Stimulated Rat Microglial and Astroglial Cultures

    Directory of Open Access Journals (Sweden)

    Joanna Mika

    2017-04-01

    Full Text Available Botulinum neurotoxin type A (BoNT/A and minocycline are potent drugs used in clinical therapies. The primary molecular mechanism of BoNT/A is the cleavage of SNARE proteins, which prevents cells from releasing neurotransmitters from vesicles, while the effects of minocycline are related to the inhibition of p38 activation. Both BoNT/A and minocycline exhibit analgesic effects, however, their direct impact on glial cells is not fully known. Therefore, the aim of the present study was to determine the effects of those drugs on microglial and astroglial activity after lipopolysaccharide (LPS stimulation and their potential synergistic action. Our results show that BoNT/A and minocycline influenced primary microglial cells by inhibiting intracellular signaling pathways, such as p38, ERK1/2, NF-κB, and the release of pro-inflammatory factors, including IL-1β, IL-18, IL-6, and NOS2. We have revealed that, in contrast to minocycline, BoNT/A treatment did not decrease LPS-induced release of pro-inflammatory factors in the astroglia. In addition, BoNT/A decreased SNAP-23 in both types of glial cells and also SNAP-25 expressed only in astrocytes. Moreover, BoNT/A increased TLR2 and its adaptor protein MyD88, but not TLR4 exclusively in microglial cells. Furthermore, we have shown the impact of BoNT/A on microglial and astroglial cells, with a particular emphasis on its molecular target, TLR2. In contrast, minocycline did not affect any of those factors. We have revealed that despite of different molecular targets, minocycline, and BoNT/A reduced the release of microglia-derived pro-inflammatory factors. In conclusion, we have shown that BoNT/A and minocycline are effective drugs for the management of neuroinflammation by dampening the activation of microglial cells, with minocycline also affecting astroglial activity.

  14. Hypothermia Reduces Toll-Like Receptor 3-Activated Microglial Interferon-β and Nitric Oxide Production

    Directory of Open Access Journals (Sweden)

    Tomohiro Matsui

    2013-01-01

    Full Text Available Therapeutic hypothermia protects neurons after injury to the central nervous system (CNS. Microglia express toll-like receptors (TLRs that play significant roles in the pathogenesis of sterile CNS injury. To elucidate the possible mechanisms involved in the neuroprotective effect of therapeutic hypothermia, we examined the effects of hypothermic culture on TLR3-activated microglial release of interferon (IFN-β and nitric oxide (NO, which are known to be associated with neuronal cell death. When rat or mouse microglia were cultured under conditions of hypothermia (33°C and normothermia (37°C with a TLR3 agonist, polyinosinic-polycytidylic acid, the production of IFN-β and NO in TLR3-activated microglia at 48 h was decreased by hypothermia compared with that by normothermia. In addition, exposure to recombinant IFN-β and sodium nitroprusside, an NO donor, caused death of rat neuronal pheochromocytoma PC12 cells in a concentration-dependent manner after 24 h. Taken together, these results suggest that the attenuation of microglial production of IFN-β and NO by therapeutic hypothermia leads to the inhibition of neuronal cell death.

  15. 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.

  16. Guizhi-jia-houpu-xingzi decoction attenuates ovalbumin- induced ...

    African Journals Online (AJOL)

    Methods: An animal model of allergic asthma (AA) in rats was established by intraperitoneal injection .... All the animal experimental protocols were according to the. International Principles of Laboratory Animal. Care [13] and approved by the Ethics Committee ..... Inflammatory Activity of Bee Venom in BV2 Microglial.

  17. Quantitating the subtleties of microglial morphology with fractal analysis

    Science.gov (United States)

    Karperien, Audrey; Ahammer, Helmut; Jelinek, Herbert F.

    2013-01-01

    It is well established that microglial form and function are inextricably linked. In recent years, the traditional view that microglial form ranges between “ramified resting” and “activated amoeboid” has been emphasized through advancing imaging techniques that point to microglial form being highly dynamic even within the currently accepted morphological categories. Moreover, microglia adopt meaningful intermediate forms between categories, with considerable crossover in function and varying morphologies as they cycle, migrate, wave, phagocytose, and extend and retract fine and gross processes. From a quantitative perspective, it is problematic to measure such variability using traditional methods, but one way of quantitating such detail is through fractal analysis. The techniques of fractal analysis have been used for quantitating microglial morphology, to categorize gross differences but also to differentiate subtle differences (e.g., amongst ramified cells). Multifractal analysis in particular is one technique of fractal analysis that may be useful for identifying intermediate forms. Here we review current trends and methods of fractal analysis, focusing on box counting analysis, including lacunarity and multifractal analysis, as applied to microglial morphology. PMID:23386810

  18. 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.

  19. Attenuation of inflammatory response by a novel chalcone protects kidney and heart from hyperglycemia-induced injuries in type 1 diabetic mice

    International Nuclear Information System (INIS)

    Fang, Qilu; Wang, Jingying; Wang, Lintao; Zhang, Yali; Yin, Haimin; Li, Yunzhou; Tong, Chao; Liang, Guang; Zheng, Chao

    2015-01-01

    High glucose-induced inflammatory response in diabetic complications plays an important role in disease occurrence and development. With inflammatory cytokines and signaling pathways as important mediators, targeting inflammation may be a new avenue for treating diabetic complications. Chalcones are a class of natural products with various pharmacological activities. Previously, we identified L2H17 as a chalcone with good anti-inflammatory activity, inhibiting LPS-induced inflammatory response in macrophages. In this study, we examined L2H17's effect on hyperglycemia-induced inflammation both in mouse peritoneal macrophages and a streptozotocin-induced T1D mouse model. Our results indicate that L2H17 exhibits a strong inhibitory effect on the expression of pro-inflammatory cytokines, cell adhesion molecules, chemokines and macrophage adhesion via modulation of the MAPK/NF-κB pathway. Furthermore, in vivo oral administration of L2H17 resulted in a significant decrease in the expression of pro-inflammatory cytokines and cell adhesion molecules, contributing to a reduction of key markers for renal and cardiac dysfunction and improvements in fibrosis and pathological changes in both renal and cardiac tissues of diabetic mice. These findings provide the evidence supporting targeting MAPK/NF-κB pathway may be effective therapeutic strategy for diabetic complications, and suggest that L2H17 may be a promising anti-inflammatory agent with potential as a therapeutic agent in the treatment of renal and cardiac diabetic complications. - Highlights: • Chalcones are a class of natural products with various pharmacological activities. • We identified L2H17 a chalcone with good anti-inflammatory activity. • L2H17 improved histological abnormalities both in diabetic heart and kidney. • L2H17 reduced inflammatory responses in HG-stimulated mouse peritoneal macrophages. • MAPKs/NF-κB pathway may be a promising therapeutic target for diabetic complications.

  20. Microglial interactions with synapses are modulated by visual experience.

    Directory of Open Access Journals (Sweden)

    Marie-Ève Tremblay

    2010-11-01

    Full Text Available Microglia are the immune cells of the brain. In the absence of pathological insult, their highly motile processes continually survey the brain parenchyma and transiently contact synaptic elements. Aside from monitoring, their physiological roles at synapses are not known. To gain insight into possible roles of microglia in the modification of synaptic structures, we used immunocytochemical electron microscopy, serial section electron microscopy with three-dimensional reconstructions, and two-photon in vivo imaging to characterize microglial interactions with synapses during normal and altered sensory experience, in the visual cortex of juvenile mice. During normal visual experience, most microglial processes displayed direct apposition with multiple synapse-associated elements, including synaptic clefts. Microglial processes were also distinctively surrounded by pockets of extracellular space. In terms of dynamics, microglial processes localized to the vicinity of small and transiently growing dendritic spines, which were typically lost over 2 d. When experience was manipulated through light deprivation and reexposure, microglial processes changed their morphology, showed altered distributions of extracellular space, displayed phagocytic structures, apposed synaptic clefts more frequently, and enveloped synapse-associated elements more extensively. While light deprivation induced microglia to become less motile and changed their preference of localization to the vicinity of a subset of larger dendritic spines that persistently shrank, light reexposure reversed these behaviors. Taken together, these findings reveal different modalities of microglial interactions with synapses that are subtly altered by sensory experience. These findings suggest that microglia may actively contribute to the experience-dependent modification or elimination of a specific subset of synapses in the healthy brain.

  1. Versatility of microglial bioenergetic machinery under starving conditions.

    Science.gov (United States)

    Nagy, Adam M; Fekete, Rebeka; Horvath, Gergo; Koncsos, Gabor; Kriston, Csilla; Sebestyen, Anna; Giricz, Zoltan; Kornyei, Zsuzsanna; Madarasz, Emilia; Tretter, Laszlo

    2018-03-01

    Microglia are highly dynamic cells in the brain. Their functional diversity and phenotypic versatility brought microglial energy metabolism into the focus of research. Although it is known that microenvironmental cues shape microglial phenotype, their bioenergetic response to local nutrient availability remains unclear. In the present study effects of energy substrates on the oxidative and glycolytic metabolism of primary - and BV-2 microglial cells were investigated. Cellular oxygen consumption, glycolytic activity, the levels of intracellular ATP/ADP, autophagy, mTOR phosphorylation, apoptosis and cell viability were measured in the absence of nutrients or in the presence of physiological energy substrates: glutamine, glucose, lactate, pyruvate or ketone bodies. All of the oxidative energy metabolites increased the rate of basal and maximal respiration. However, the addition of glucose decreased microglial oxidative metabolism and glycolytic activity was enhanced. Increased ATP/ADP ratio and cell viability, activation of the mTOR and reduction of autophagic activity were observed in glutamine-supplemented media. Moreover, moderate and transient oxidation of ketone bodies was highly enhanced by glutamine, suggesting that anaplerosis of the TCA-cycle could stimulate ketone body oxidation. It is concluded that microglia show high metabolic plasticity and utilize a wide range of substrates. Among them glutamine is the most efficient metabolite. To our knowledge these data provide the first account of microglial direct metabolic response to nutrients under short-term starvation and demonstrate that microglia exhibit versatile metabolic machinery. Our finding that microglia have a distinct bioenergetic profile provides a critical foundation for specifying microglial contributions to brain energy metabolism. Copyright © 2017. Published by Elsevier B.V.

  2. Vitamin D Treatment Attenuates Neuroinflammation and Dopaminergic Neurodegeneration in an Animal Model of Parkinson's Disease, Shifting M1 to M2 Microglia Responses.

    Science.gov (United States)

    Calvello, Rosa; Cianciulli, Antonia; Nicolardi, Giuseppe; De Nuccio, Francesco; Giannotti, Laura; Salvatore, Rosaria; Porro, Chiara; Trotta, Teresa; Panaro, Maria Antonietta; Lofrumento, Dario Domenico

    2017-06-01

    Microglia-mediated neuroinflammation has been described as a common hallmark of Parkinson's disease (PD) and is believed to further exacerbate the progressive degeneration of dopaminergic neurons. Current therapies are unable to prevent the disease progression. A significant association has been demonstrated between PD and low levels of vitamin D in patients serum, and vitamin D supplement appears to have a beneficial clinical effect. Herein, we investigated whether vitamin D administered orally in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced preclinical animal model of PD protects against glia-mediated inflammation and nigrostriatal neurodegeneration. Vitamin D significantly attenuated the MPTP-induced loss of tyrosine hydrlase (TH)-positive neuronal cells, microglial cell activation (Iba1-immunoreactive), inducible nitric oxide synthase (iNOS) and TLR-4 expression, typical hallmarks of the pro-inflammatory (M1) activation of microglia. Additionally, Vitamin D was able to decrease pro-inflammatory cytokines mRNA expression in distinct brain areas of the MPTP mouse. Importantly, we also assessed the anti-inflammatory property of vitamin D in the MPTP mouse, in which it upregulated the anti-inflammatory cytokines (IL-10, IL-4 and TGF-β) mRNA expression as well as increasing the expression of CD163, CD206 and CD204, typical hallmarks of alternative activation of microglia for anti-inflammatory signalling (M2). Collectively, these results demonstrate that vitamin D exhibits substantial neuroprotective effects in this PD animal model, by attenuating pro-inflammatory and up-regulating anti-inflammatory processes.

  3. 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

    2014-01-01

    Study Objectives: 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. Design: 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. Participants: Male Sprague-Dawley rats, weighing 180-250 g (n = 190), were used. Measurements: 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. Results: 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. Conclusions: 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. Citation: Huang CT, Chiang RP, Chen CL, Tsai YJ. Sleep

  4. 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.

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

    Science.gov (United States)

    Talbot, Sébastien; Chahmi, Emna; Dias, Jenny Pena; Couture, Réjean

    2010-06-29

    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. 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. 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-1beta, TNF-alpha, TRPV1) and Iba-1 immunoreactivity in the STZ spinal cord were normalized by fluorocitrate or minocycline, yet B1R binding sites were reduced by 38%. 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. Cinnamon extract attenuates TNF-alpha-induced intestinal lipoprotein ApoB48 overproduction by regulating inflammatory, insulin, and lipoprotein pathways in enterocytes

    Science.gov (United States)

    We evaluated whether a water extract of cinnamon (CE = Cinnulin PF®) attenuates the dyslipidemia induced by TNF-alpha in Triton WR-1339-treated hamsters, and whether CE inhibited the over-secretion of apoB48-induced by TNF-alpha in enterocytes in a 35S-labelling study. In vivo, oral treatment with C...

  7. Parenteral MCT/ω-3 Polyunsaturated Fatty Acid-Enriched Intravenous Fat Emulsion Is Associated With Cytokine and Fatty Acid Profiles Consistent With Attenuated Inflammatory Response in Preterm Neonates: A Randomized, Double-Blind Clinical Trial.

    Science.gov (United States)

    Skouroliakou, Maria; Konstantinou, Dimitris; Agakidis, Charalampos; Kaliora, Andriana; Kalogeropoulos, Nick; Massara, Paraskevi; Antoniadi, Marina; Panagiotakos, Demosthenes; Karagiozoglou-Lampoudi, Thomais

    2016-04-01

    Soybean oil-based intravenous fat emulsion (IVFE) administered to preterm neonates can induce oxidative stress and inflammatory response, which are associated with severe complications of prematurity. This study aimed to test the hypothesis that administration of medium-chain triglyceride (MCT)/ω-3 polyunsaturated fatty acid (PUFA)-enriched IVFE in preterm neonates is associated with a cytokine and fatty acid (FA) profile consistent with attenuated inflammatory response. In a double-blind randomized study, 60 preterm neonates (gestational age 26-32 weeks) were randomized to receive either MCT/ω-3 PUFA-enriched IVFE (intervention group) or soybean oil-based IVFE (control group). Serum biochemistry, tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-8, α-tocopherol, and FAs were assessed at baseline, on day of life 15, and day of life 30 or at the end of intervention. All cytokine levels changed significantly across the 3 time points, whereas the type of IVFE had a significant effect on final IL-6 and IL-8 levels, which were lower in the intervention group. The difference in final IL-6 and IL-8 levels remained significant after controlling for bronchopulmonary dysplasia and/or infection. α-Tocopherol and FA values changed significantly over time. MCT/ω-3 PUFA-enriched IVFE administration was associated with significantly higher α-tocopherol, eicosapentaenoic acid, docosahexaenoic acid, and ω-3 PUFAs and lower linolenic acid, total PUFA, and ω-6/ω-3 PUFA values compared with soybean oil-based IVFE. Both IVFEs were well tolerated. Compared with the soybean oil-based IVFE, the MCT/ω-3 PUFA-enriched IVFE is associated with a more favorable cytokine and FA profile consistent with attenuated inflammatory response in preterm neonates. © 2015 American Society for Parenteral and Enteral Nutrition.

  8. Microglial recruitment, activation, and proliferation in response to primary demyelination

    DEFF Research Database (Denmark)

    Remington, Leah T; Babcock, Alicia A; Zehntner, Simone P

    2007-01-01

    microglial numbers. Microglia adopted an activated phenotype during demyelination, up-regulating major histocompatibility class I and B7.2/CD86. A subpopulation of CD45(dim-high) microglia that expressed reduced levels of CD11b emerged during demyelination. These microglia expressed CD11c and were potent...

  9. 5-aminoimidazole-4-carboxamide-1-beta-4-ribofuranoside (AICAR attenuates the expression of LPS- and Aβ peptide-induced inflammatory mediators in astroglia

    Directory of Open Access Journals (Sweden)

    Giri Shailendra

    2005-09-01

    Full Text Available Abstract Background Alzheimer's disease (AD pathology shows characteristic 'plaques' rich in amyloid beta (Aβ peptide deposits. Inflammatory process-related proteins such as pro-inflammatory cytokines have been detected in AD brain suggesting that an inflammatory immune reaction also plays a role in the pathogenesis of AD. Glial cells in culture respond to LPS and Aβ stimuli by upregulating the expression of cytokines TNF-α, IL-1β, and IL-6, and also the expression of proinflammatory genes iNOS and COX-2. We have earlier reported that LPS/Aβ stimulation-induced ceramide and ROS generation leads to iNOS expression and nitric oxide production in glial cells. The present study was undertaken to investigate the neuroprotective function of AICAR (a potent activator of AMP-activated protein kinase in blocking the pro-oxidant/proinflammatory responses induced in primary glial cultures treated with LPS and Aβ peptide. Methods To test the anti-inflammatory/anti-oxidant functions of AICAR, we tested its inhibitory potential in blocking the expression of pro-inflammatory cytokines and iNOS, expression of COX-2, generation of ROS, and associated signaling following treatment of glial cells with LPS and Aβ peptide. We also investigated the neuroprotective effects of AICAR against the effects of cytokines and inflammatory mediators (released by the glia, in blocking neurite outgrowth inhibition, and in nerve growth factor-(NGF induced neurite extension by PC-12 cells. Results AICAR blocked LPS/Aβ-induced inflammatory processes by blocking the expression of proinflammatory cytokine, iNOS, COX-2 and MnSOD genes, and by inhibition of ROS generation and depletion of glutathione in astroglial cells. AICAR also inhibited down-stream signaling leading to the regulation of transcriptional factors such as NFκB and C/EBP which are critical for the expression of iNOS, COX-2, MnSOD and cytokines (TNF-α/IL-1β and IL-6. AICAR promoted NGF-induced neurite growth

  10. 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.

  11. Turkish Scorzonera Species Extracts Attenuate Cytokine Secretion via Inhibition of NF-kappa B Activation, Showing Anti-Inflammatory Effect in Vitro

    Czech Academy of Sciences Publication Activity Database

    Acikara, O. B.; Hošek, J.; Babula, P.; Cvačka, Josef; Buděšínský, Miloš; Dračínský, Martin; Iscan, G. S.; Kadlecová, D.; Ballová, L.; Šmejkal, K.

    2016-01-01

    Roč. 21, č. 1 (2016), č. článku 43. ISSN 1420-3049 Institutional support: RVO:61388963 Keywords : anti-inflammatory activity * IL-1 beta * NF-kappa B * Scorzonera * phenolic * TNF-alpha * triterpen Subject RIV: CC - Organic Chemistry Impact factor: 2.861, year: 2016 http://www.mdpi.com/1420-3049/21/1/43/htm

  12. The pro-resolving lipid mediator Maresin 1 protects against cerebral ischemia/reperfusion injury by attenuating the pro-inflammatory response

    Energy Technology Data Exchange (ETDEWEB)

    Xian, Wenjing [Department of Anesthesiology, Institute of Anesthesiology and Critical Care Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); Wu, Yan [Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); Xiong, Wei [Department of Anesthesiology, Institute of Anesthesiology and Critical Care Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); Department of Critical Care Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); Li, Longyan [Department of Critical Care Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); Li, Tong [Department of Hepatobiliary Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); Pan, Shangwen [Department of Critical Care Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); Song, Limin [Department of Anesthesiology, Institute of Anesthesiology and Critical Care Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); Department of Critical Care Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); Hu, Lisha [Department of Critical Care Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); Pei, Lei [Department of Neurobiology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); Yao, Shanglong, E-mail: ysltian@163.com [Department of Anesthesiology, Institute of Anesthesiology and Critical Care Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); and others

    2016-03-25

    Inflammation plays a crucial role in acute ischemic stroke pathogenesis. Macrophage-derived Maresin 1 (MaR1) is a newly uncovered mediator with potent anti-inflammatory abilities. Here, we investigated the effect of MaR1 on acute inflammation and neuroprotection in a mouse brain ischemia reperfusion (I/R) model. Male C57 mice were subjected to 1-h middle cerebral artery occlusion (MCAO) and reperfusion. By the methods of 2,3,5-triphenyltetrazolium chloride, haematoxylin and eosin or Fluoro-Jade B staining, neurological deficits scoring, ELISA detection, immunofluorescence assay and western blot analysis, we found that intracerebroventricular injection of MaR1 significantly reduced the infarct volume and neurological defects, essentially protected the brain tissue and neurons from injury, alleviated pro-inflammatory reactions and NF-κB p65 activation and nuclear translocation. Taken together, our results suggest that MaR1 significantly protects against I/R injury probably by inhibiting pro-inflammatory reactions. - Highlights: • MaR1 significantly protects against ischemia reperfusion injury. • MaR1 inhibits pro-inflammatory cytokines and chemokines and reducing glial activation and neutrophil infiltration. • These effects at least partially occurred via suppression of the NF-κB p65 signalling pathway.

  13. Low-dose benznidazole treatment results in parasite clearance and attenuates heart inflammatory reaction in an experimental model of infection with a highly virulent Trypanosoma cruzi strain.

    Science.gov (United States)

    Cevey, Ágata Carolina; Mirkin, Gerardo Ariel; Penas, Federico Nicolás; Goren, Nora Beatriz

    2016-04-01

    Chagas disease, caused by Trypanosoma cruzi, is the main cause of dilated cardiomyopathy in the Americas. Antiparasitic treatment mostly relies on benznidazole (Bzl) due to Nifurtimox shortage or unavailability. Both induce adverse drug effects (ADE) of varied severity in many patients, leading to treatment discontinuation or abandonment. Since dosage may influence ADE, we aimed to assess Bzl efficacy in terms of parasiticidal and anti-inflammatory activity, using doses lower than those previously reported. BALB/c mice infected with the T. cruzi RA strain were treated with different doses of Bzl. Parasitaemia, mortality and weight change were assessed. Parasite load, tissue infiltrates and inflammatory mediators were studied in the heart. Serum creatine kinase (CK) activity was determined as a marker of heart damage. The infection-independent anti-inflammatory properties of Bzl were studied in an in vitro model of LPS-treated cardiomyocyte culture. Treatment with 25 mg/kg/day Bzl turned negative the parasitological parameters, induced a significant decrease in IL-1β, IL-6 and NOS2 in the heart and CK activity in serum, to normal levels. No mortality was observed in infected treated mice. Primary cultured cardiomyocytes treated with Bzl showed that inflammatory mediators were reduced via inhibition of the NF-κB pathway. A Bzl dose lower than that previously reported for treatment of experimental Chagas disease exerts adequate antiparasitic and anti-inflammatory effects leading to parasite clearance and tissue healing. This may be relevant to reassess the dose currently used for the treatment of human Chagas disease, aiming to minimize ADE.

  14. Low-dose benznidazole treatment results in parasite clearance and attenuates heart inflammatory reaction in an experimental model of infection with a highly virulent Trypanosoma cruzi strain

    Directory of Open Access Journals (Sweden)

    Ágata Carolina Cevey

    2016-04-01

    Full Text Available Chagas disease, caused by Trypanosoma cruzi, is the main cause of dilated cardiomyopathy in the Americas. Antiparasitic treatment mostly relies on benznidazole (Bzl due to Nifurtimox shortage or unavailability. Both induce adverse drug effects (ADE of varied severity in many patients, leading to treatment discontinuation or abandonment. Since dosage may influence ADE, we aimed to assess Bzl efficacy in terms of parasiticidal and anti-inflammatory activity, using doses lower than those previously reported. BALB/c mice infected with the T. cruzi RA strain were treated with different doses of Bzl. Parasitaemia, mortality and weight change were assessed. Parasite load, tissue infiltrates and inflammatory mediators were studied in the heart. Serum creatine kinase (CK activity was determined as a marker of heart damage. The infection-independent anti-inflammatory properties of Bzl were studied in an in vitro model of LPS-treated cardiomyocyte culture. Treatment with 25 mg/kg/day Bzl turned negative the parasitological parameters, induced a significant decrease in IL-1β, IL-6 and NOS2 in the heart and CK activity in serum, to normal levels. No mortality was observed in infected treated mice. Primary cultured cardiomyocytes treated with Bzl showed that inflammatory mediators were reduced via inhibition of the NF-κB pathway. A Bzl dose lower than that previously reported for treatment of experimental Chagas disease exerts adequate antiparasitic and anti-inflammatory effects leading to parasite clearance and tissue healing. This may be relevant to reassess the dose currently used for the treatment of human Chagas disease, aiming to minimize ADE.

  15. Riboflavin Reduces Pro-Inflammatory Activation of Adipocyte-Macrophage Co-culture. Potential Application of Vitamin B2 Enrichment for Attenuation of Insulin Resistance and Metabolic Syndrome Development.

    Science.gov (United States)

    Mazur-Bialy, Agnieszka Irena; Pocheć, Ewa

    2016-12-15

    Due to the progressive increase in the incidence of obese and overweight individuals, cardiometabolic syndrome has become a worldwide pandemic in recent years. Given the immunomodulatory properties of riboflavin, the current study was performed to investigate the potency of riboflavin in reducing obesity-related inflammation, which is the main cause of insulin resistance, diabetes mellitus 2 or arteriosclerosis. We determined whether pretreatment with a low dose of riboflavin (10.4-1000 nM) affected the pro-inflammatory activity of adipocyte-macrophage co-culture (3T3 L1-RAW 264.7) following lipopolysaccharide stimulation (LPS; 100 ng/mL) which mimics obesity-related inflammation. The apoptosis of adipocytes and macrophages as well as tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), interleukin 1beta (IL-1β), monocyte chemotactic protein 1 (MCP-1), high-mobility group box 1 (HMGB1), transforming growth factor-beta 1 (TGFβ), interleukin 10 (IL-10), inducible nitric oxide synthase (iNOS), nitric oxide (NO), matrix metalloproteinase 9 (MMP-9), tissue inhibitor of metalloproteinases-1 (TIMP-1) expression and release, macrophage migration and adipokines (adiponectin and leptin) were determined. Our results indicated an efficient reduction in pro-inflammatory factors (TNFα, IL-6, MCP-1, HMGB1) upon culture with riboflavin supplementation (500-1000 nM), accompanied by elevation in anti-inflammatory adiponectin and IL-10. Moreover, macrophage migration was reduced by the attenuation of chemotactic MCP-1 release and degradation of the extracellular matrix by MMP-9. In conclusion, riboflavin effectively inhibits the pro-inflammatory activity of adipocyte and macrophage co-cultures, and therefore we can assume that its supplementation may reduce the likelihood of conditions associated with the mild inflammation linked to obesity.

  16. Relationship between fluid-attenuated inversion-recovery (FLAIR) signal intensity and inflammatory mediator's levels in the hippocampus of patients with temporal lobe epilepsy and mesial temporal sclerosis.

    Science.gov (United States)

    Varella, Pedro Paulo Vasconcellos; Santiago, Joselita Ferreira Carvalho; Carrete, Henrique; Higa, Elisa Mieko Suemitsu; Yacubian, Elza Márcia Targas; Centeno, Ricardo Silva; Caboclo, Luís Otávio Sales Ferreira; Castro Neto, Eduardo Ferreira de; Canzian, Mauro; Amado, Débora; Cavalheiro, Esper Abrão; Naffah-Mazzacoratti, Maria da Graça

    2011-02-01

    We investigated a relationship between the FLAIR signal found in mesial temporal sclerosis (MTS) and inflammation. Twenty nine patients were selected through clinical and MRI analysis and submitted to cortico-amygdalo-hippocampectomy to seizure control. Glutamate, TNFα, IL1, nitric oxide (NO) levels and immunostaining against IL1β and CD45 was performed. Control tissues (n=10) were obtained after autopsy of patients without neurological disorders. The glutamate was decreased in the temporal lobe epilepsy (TLE) -MTS group (p<0.001), suggesting increased release of this neurotransmitter. The IL1β and TNFα were increased in the hippocampus (p<0.05) demonstrating an active inflammatory process. A positive linear correlation between FLAIR signal and NO and IL1β levels and a negative linear correlation between FLAIR signal and glutamate concentration was found. Lymphocytes infiltrates were present in hippocampi of TLE patients. These data showed an association between hippocampal signal alteration and increased inflammatory markers in TLE-MTS.

  17. Pro-Inflammatory Cytokine TNF-α Attenuates BMP9-Induced Osteo/ Odontoblastic Differentiation of the Stem Cells of Dental Apical Papilla (SCAPs

    Directory of Open Access Journals (Sweden)

    Feilong Wang

    2017-03-01

    Full Text Available Background/Aims: Periapical periodontitis is a common oral disease caused by bacterial invasion of the tooth pulp, which usually leads to local release of pro-inflammatory cytokines and osteolytic lesion. This study is intended to examine the effect of TNF-α on BMP9-induced osteogenic differentiation of the stem cells of dental apical papilla (SCAPs. Methods: Rat model of periapical periodontitis was established. TNF-α expression was assessed. Osteogenic markers and ectopic bone formation in iSCAPs were analyzed upon BMP9 and TNF-α treatment. Results: Periapical periodontitis was successfully established in rat immature permanent teeth with periapical lesions, in which TNF-α was shown to release during the inflammatory phase. BMP9-induced alkaline phosphatase activity, the expression of osteocalcin and osteopontin, and matrix mineralization in iSCAPs were inhibited by TNF-α in a dose-dependent fashion, although increased AdBMP9 partially overcame TNF-α inhibition. Furthermore, high concentration of TNF-α effectively inhibited BMP9-induced ectopic bone formation in vivo. Conclusion: TNF-α plays an important role in periapical bone defect during the inflammatory phase and inhibits BMP9-induced osteoblastic differentiation of iSCAPs, which can be partially reversed by high levels of BMP9. Therefore, BMP9 may be further explored as a potent osteogenic factor to improve osteo/odontogenic differentiation in tooth regeneration in chronic inflammation conditions.

  18. Plectranthus amboinicus attenuates inflammatory bone erosion in mice with collagen-induced arthritis by downregulation of RANKL-induced NFATc1 expression.

    Science.gov (United States)

    Hsu, Yu-Chieh; Cheng, Chia-Pi; Chang, Deh-Ming

    2011-09-01

    Plectranthus amboinicus has been known to treat inflammatory diseases or swelling symptoms. We investigated whether P. amboinicus exhibited an inhibitory effect on osteoclastogenesis in vitro and inflammatory bone erosion in collagen-induced arthritis (CIA) mice, an animal model of rheumatoid arthritis. We attempted to identify the active component of P. amboinicus involved in regulation of osteoclastogenesis. We treated M-CSF- and RANKL-stimulated murine bone marrow-derived macrophages (BMM) and RANKL-induced RAW264.7 cells with different concentrations of P. amboinicus or rosmarinic acid, a phytopolyphenol purified from P. amboinicus, to monitor osteoclast formation by TRAP staining. The mechanism of the inhibition was studied by biochemical analysis such as RT-PCR and immunoblotting. CIA mice were administered gavages of P. amboinicus (375 mg/kg) or placebo. Then clinical, histological, and biochemical measures were assessed to determine the effects of P. amboinicus on synovial inflammation and bone erosion by H&E staining of the inflamed joints and ELISA. Rosmarinic acid strongly inhibited RANKL-induced NF-κB activation and nuclear factor of activated T cells c1 (NFATc1) nuclear translocation in BMM, and also inhibited RANKL-induced formation of TRAP-positive multinucleated cells. A pit formation assay and the CIA animal model showed that P. amboinicus significantly inhibited the bone-resorbing activity of mature osteoclasts. We postulated that rosmarinic acid conferred the inhibitory activity on P. amboinicus for inhibition of osteoclastogenesis via downregulation of RANKL-induced NFATc1 expression. Our results indicated the possibility of P. amboinicus as a new remedy against inflammatory bone destruction.

  19. Bioassay-guided fractionation of ethyl acetate extract from Armillaria mellea attenuates inflammatory response in lipopolysaccharide (LPS) stimulated BV-2 microglia.

    Science.gov (United States)

    Geng, Yan; Zhu, Shuiling; Cheng, Peng; Lu, Zhen-Ming; Xu, Hong-Yu; Shi, Jin-Song; Xu, Zheng-Hong

    2017-03-15

    Armillaria mellea (A. mellea) is a traditional Chinese medicinal and edible mushroom, which is proved to possess a lot of biological activities, including anti-oxidation, immunopotentiation, anti-vertigo and anti-aging activities. However, little information is available in regard to its neuroprotection activity in inflammation-mediated neurodegenerative diseases. We have found that A. mellea has an anti-inflammatory activity in LPS-induced RAW264.7 cells in our previous study. The objective of this study is to investigate the anti-neuroinflammatory mechanism of a bioassay-guided fractionation (Fr.2) and its active components/compounds. Compounds were isolated by preparative high performance liquid chromatography (pre-HPLC) and their structures were established by mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopic analyses. The anti-neuroinflammatory effect of Fr.2 and each compounds were investigated in lipopolysaccharide (LPS)-stimulated murine microglia cell lineBV-2. We demonstrated that Fr.2 significantly decreased the production of inflammation mediator nitric oxide (NO) and inflammatory cytokines tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6) and interleukin-1beta (IL-1β) in a dose-dependent manner (10, 30, 100µg/ml). In addition, Fr.2 markedly down-regulated the phosphorylation levels of nuclear factor kappa B p65 (NF-κB p65), inhibitory κB-α (IκB-α) and c-Jun N-terminal kinases (JNKs) pathways. Sevens compounds were isolated from Fr.2, among them, three compounds, 5-hydroxymethylfurfural (CP1), vanillic acid (CP4) and syringate (CP5) were reported for the first time in A. mellea. NO and inflammatory cytokines (TNF-α, IL-6, IL-1β) secretion indicated that daidzein (CP6) and genistein (CP7) showed a more outstanding anti-inflammation potential at non-toxic concentrations (10, 30, 100µM) than the other five compounds. In conclusion, Fr.2 may have therapeutic potential for neurodegenerative diseases by inhibiting

  20. Sex differences in microglial phagocytosis in the neonatal hippocampus.

    Science.gov (United States)

    Nelson, Lars H; Warden, Spencer; Lenz, Kathryn M

    2017-08-01

    Microglia regulate brain development through many processes, such as promoting neurogenesis, supporting cell survival, and phagocytizing progenitor, newly-born, and dying cells. Many of these same developmental processes show robust sex differences, yet very few studies have assessed sex differences in microglia function during development. Hormonally-induced sexual differentiation of the brain occurs during the perinatal period, thus we examined sex differences in microglial morphology, phagocytosis, and proliferation in the hippocampus during the early postnatal period. We found that the neonatal female hippocampus had significantly more microglia with phagocytic cups than the male hippocampus. We subsequently found that female microglia phagocytized more neural progenitor cells and healthy cells compared to males, but there were no sex differences in the number of newly-born or dying cells targeted by microglial phagocytosis. We found that the number of phagocytic microglia in females was reduced to male-typical levels by treatment with estradiol, the hormone responsible for masculinizing the rodent brain. Females also had higher expression of several phagocytic pathway genes in the hippocampus compared to males. In contrast to robust sex differences in phagocytic microglia, we found no sex differences in the number of microglia with amoeboid, transitioning, or ramified morphologies or differences in three-dimensional reconstructions of microglial morphology. While we did not find a baseline sex difference in microglial proliferation during or following the prenatal gonadal hormone surge in males, we found that estradiol treatment increased microglia proliferation in females. Overall, these data show that there are important sex differences in microglia function in the hippocampus during the early neonatal period. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. A histochemical study of the microglial cells in the brain of Salamandra salamandra by lectin binding.

    Science.gov (United States)

    Franceschini, V; Ciani, F

    1992-01-01

    Seven biotinylated lectins were utilized as histochemical markers for the study of microglial cells in the brain of Salamandra salamandra. It has been demonstrated that SBA, BSA-I, BSA-I-B4 and RCA120 label the microglial cells and, on the basis of the binding selectivity of the single lectins for specific carbohydrates, it was found that alpha-galactosyl residues are present in high density on the microglial membrane of S. salamandra. The reaction was localized not only to the ramified microglial cells, but also to other round cells without extensions, interpreted as ameboid microglial cells. The results show that lectin binding is a reliable molecular probe for identifying microglial cells in urodels.

  2. Microglial Dysfunction in Brain Aging and Alzheimer’s Disease

    Science.gov (United States)

    Mosher, Kira Irving; Wyss-Coray, Tony

    2014-01-01

    Microglia, the immune cells of the central nervous system, have long been a subject of study in the Alzheimer’s disease (AD) field due to their dramatic responses to the pathophysiology of the disease. With several large-scale genetic studies in the past year implicating microglial molecules in AD, the potential significance of these cells has become more prominent than ever before. As a disease that is tightly linked to aging, it is perhaps not entirely surprising that microglia of the AD brain share some phenotypes with aging microglia. Yet the relative impacts of both conditions on microglia are less frequently considered in concert. Furthermore, microglial “activation” and “neuroinflammation” are commonly analyzed in studies of neurodegeneration but are somewhat ill-defined concepts that in fact encompass multiple cellular processes. In this review, we have enumerated six distinct functions of microglia and discuss the specific effects of both aging and AD. By calling attention to the commonalities of these two states, we hope to inspire new approaches for dissecting microglial mechanisms. PMID:24445162

  3. Relationship between fluid-attenuated inversion-recovery (FLAIR signal intensity and inflammatory mediator's levels in the hippocampus of patients with temporal lobe epilepsy and mesial temporal sclerosis

    Directory of Open Access Journals (Sweden)

    Pedro Paulo Vasconcellos Varella

    2011-02-01

    Full Text Available We investigated a relationship between the FLAIR signal found in mesial temporal sclerosis (MTS and inflammation. Twenty nine patients were selected through clinical and MRI analysis and submitted to cortico-amygdalo-hippocampectomy to seizure control. Glutamate, TNFα, IL1, nitric oxide (NO levels and immunostaining against IL1β and CD45 was performed. Control tissues (n=10 were obtained after autopsy of patients without neurological disorders. The glutamate was decreased in the temporal lobe epilepsy (TLE -MTS group (p<0.001, suggesting increased release of this neurotransmitter. The IL1β and TNFα were increased in the hippocampus (p<0.05 demonstrating an active inflammatory process. A positive linear correlation between FLAIR signal and NO and IL1β levels and a negative linear correlation between FLAIR signal and glutamate concentration was found. Lymphocytes infiltrates were present in hippocampi of TLE patients. These data showed an association between hippocampal signal alteration and increased inflammatory markers in TLE-MTS.

  4. The potential role of suppressors of cytokine signaling in the attenuation of inflammatory reaction and alveolar bone loss associated with apical periodontitis.

    Science.gov (United States)

    Menezes, Renato; Garlet, Thiago Pompermaier; Trombone, Ana Paula Fávaro; Repeke, Carlos Eduardo; Letra, Ariadne; Granjeiro, José Mauro; Campanelli, Ana Paula; Garlet, Gustavo Pompermaier

    2008-12-01

    Inflammatory cytokines contribute to periapical tissue destruction. Their activity is potentially regulated by suppressors of cytokine signaling (SOCS), which downregulate signal transduction as part of an inhibitory feedback loop. We investigated the expression of the cytokines tumor necrosis factor alpha (TNF-alpha); interleukin (IL)-10 and RANKL; and SOCS-1, -2, and -3 by real-time polymerase chain reaction in 57 periapical granulomas and 38 healthy periapical tissues. Periapical granulomas exhibited significantly higher SOCS-1, -2, and -3, TNF-alpha, IL-10, and RANKL messenger RNA levels when compared with healthy controls. Significant positive correlations were found between SOCS1 and IL-10 and between SOCS3 and IL-10. Significant inverse correlations were observed between SOCS1 and TNF-alpha, SOCS1 and RANKL, and SOCS3 and TNF-alpha. Increased SOCS-1, -2, and -3 messenger RNA levels in periapical granulomas may be related to the downregulation of inflammatory cytokines in these lesions; therefore, SOCS molecules may play a role in the dynamics of periapical granulomas development.

  5. Actin filament-associated protein 1 (AFAP-1) is a key mediator in inflammatory signaling-induced rapid attenuation of intrinsic P-gp function in human brain capillary endothelial cells.

    Science.gov (United States)

    Hoshi, Yutaro; Uchida, Yasuo; Tachikawa, Masanori; Ohtsuki, Sumio; Terasaki, Tetsuya

    2017-04-01

    The purpose of this study was to identify regulatory molecule(s) involved in the inflammatory signaling-induced decrease in P-glycoprotein (P-gp) efflux function at the blood-brain barrier (BBB) that may occur in brain diseases. We confirmed that in vivo P-gp efflux activity at the BBB was decreased without any change in P-gp protein expression level in a mouse model of acute inflammation induced by 3 mg/kg lipopolysaccharide. In a human BBB model cell line (human brain capillary endothelial cells; hCMEC/D3), 1-h treatment with 10 ng/mL tumor necrosis factor-α (TNF-α; an inflammatory mediator) rapidly reduced P-gp efflux activity, but had no effect on P-gp protein expression level. To clarify the non-transcriptional mechanism that causes the decrease in intrinsic efflux activity of P-gp in acute inflammation, we applied comprehensive quantitative phosphoproteomics to compare hCMEC/D3 cells treated with TNF-α and vehicle (control). Actin filament-associated protein-1 (AFAP-1), MAPK1, and transcription factor AP-1 (AP-1) were significantly phosphorylated in TNF-α-treated cells, and were selected as candidate proteins. In validation experiments, knockdown of AFAP-1 expression blocked the reduction in P-gp efflux activity by TNF-α treatment, whereas inhibition of MAPK function or knockdown of AP-1 expression did not. Quantitative targeted absolute proteomics revealed that the reduction in P-gp activity by TNF-α did not require any change in P-gp protein expression levels in the plasma membrane. Our results demonstrate that AFAP-1 is a key mediator in the inflammatory signaling-induced, translocation-independent rapid attenuation of P-gp efflux activity in human brain capillary endothelial cells. © 2017 International Society for Neurochemistry.

  6. YY-1224, a terpene trilactone-strengthened Ginkgo biloba, attenuates neurodegenerative changes induced by β-amyloid (1-42) or double transgenic overexpression of APP and PS1 via inhibition of cyclooxygenase-2.

    Science.gov (United States)

    Li, Zheng-Yi; Chung, Yoon Hee; Shin, Eun-Joo; Dang, Duy-Khanh; Jeong, Ji Hoon; Ko, Sung Kwon; Nah, Seung-Yeol; Baik, Tae Gon; Jhoo, Jin Hyeong; Ong, Wei-Yi; Nabeshima, Toshitaka; Kim, Hyoung-Chun

    2017-04-27

    Ginkgo biloba has been reported to possess free radical-scavenging antioxidant activity and anti-inflammatory properties. In our pilot study, YY-1224, a terpene trilactone-strengthened extract of G. biloba, showed anti-inflammatory, neurotrophic, and antioxidant effects. We investigated the pharmacological potential of YY-1224 in β-amyloid (Aβ) (1-42)-induced memory impairment using cyclooxygenase-2 (COX-2) knockout (-/-) and APPswe/PS1dE9 transgenic (APP/PS1 Tg) mice. Repeated treatment with YY-1224 significantly attenuated Aβ (1-42)-induced memory impairment in COX-2 (+/+) mice, but not in COX-2 (-/-) mice. YY-1224 significantly attenuated Aβ (1-42)-induced upregulation of platelet-activating factor (PAF) receptor gene expression, reactive oxygen species, and pro-inflammatory factors. In addition, YY-1224 significantly inhibited Aβ (1-42)-induced downregulation of PAF-acetylhydrolase-1 (PAF-AH-1) and peroxisome proliferator-activated receptor γ (PPARγ) gene expression. These changes were more pronounced in COX-2 (+/+) mice than in COX-2 (-/-) mice. YY-1224 significantly attenuated learning impairment, Aβ deposition, and pro-inflammatory microglial activation in APP/PS1 Tg mice, whereas it significantly enhanced PAF-AH and PPARγ expression. A preferential COX-2 inhibitor, meloxicam, did not affect the pharmacological activity by YY-1224, suggesting that the COX-2 gene is a critical mediator of the neuroprotective effects of YY-1224. The protective activity of YY-1224 appeared to be more efficacious than a standard G. biloba extract (Gb) against Aβ insult. Our results suggest that the protective effects of YY-1224 against Aβ toxicity may be associated with its PAF antagonistic- and PPARγ agonistic-potential as well as inhibition of the Aβ-mediated pro-inflammatory switch of microglia phenotypes through suppression of COX-2 expression.

  7. Arctigenin but not arctiin acts as the major effective constituent of Arctium lappa L. fruit for attenuating colonic inflammatory response induced by dextran sulfate sodium in mice.

    Science.gov (United States)

    Wu, Xin; Yang, Yan; Dou, Yannong; Ye, Jun; Bian, Difei; Wei, Zhifeng; Tong, Bei; Kong, Lingyi; Xia, Yufeng; Dai, Yue

    2014-12-01

    The crude powder of the fruit of Arctium lappa L. (ALF) has previously been reported to attenuate experimental colitis in mice. But, its main effective ingredient and underlying mechanisms remain to be identified. In this study, ALF was extracted with ethanol, and then successively fractionated into petroleum ether, ethyl acetate, n-butanol and water fraction. Experimental colitis was induced by dextran sulfate sodium (DSS) in mice. Among the four fractions of ALF, the ethyl acetate fraction showed the most significant inhibition of DSS-induced colitis in mice. The comparative studies of arctigenin and arctiin (the two main ingredients of ethyl acetate fraction) indicated that arctigenin rather than arctiin could reduce the loss of body weight, disease activity index and histological damage in the colon. Arctigenin markedly recovered the loss of intestinal epithelial cells (E-cadherin-positive cells) and decreased the infiltration of neutrophils (MPO-positive cells) and macrophages (CD68-positive cells). Arctigenin could down-regulate the expressions of TNF-α, IL-6, MIP-2, MCP-1, MAdCAM-1, ICAM-1 and VCAM-1 at both protein and mRNA levels in colonic tissues. Also, it markedly decreased the MDA level, but increased SOD activity and the GSH level. Of note, the efficacy of arctigenin was comparable or even superior to that of the positive control mesalazine. Moreover, it significantly suppressed the phosphorylation of MAPKs and the activation of NF-κB, including phosphorylation of IκBα and p65, p65 translocation and DNA binding activity. In conclusion, arctigenin but not arctiin is the main active ingredient of ALF for attenuating colitis via down-regulating the activation of MAPK and NF-κB pathways. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. 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.

  9. 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.

  10. Targeting beta- and alpha-adrenergic receptors differentially shifts Th1, Th2, and inflammatory cytokine profiles in immune organs to attenuate adjuvant arthritis

    Directory of Open Access Journals (Sweden)

    Dianne eLorton

    2014-08-01

    Full Text Available The sympathetic nervous system (SNS regulates host defense responses and restores homeostasis. SNS-immune regulation is altered in rheumatoid arthritis (RA and rodent models of RA, characterized by nerve remodeling in immune organs and defective adrenergic receptor (AR signaling to immune cell targets that typically promotes or suppresses inflammation via α- and β2-AR activation, respectively, and indirectly drives humoral immunity by blocking Th1 cytokine secretion. Here, we investigate how β2-AR stimulation and/or α-AR blockade at disease onset affects disease pathology and cytokine profiles in relevant immune organs from male Lewis rats with adjuvant-induced arthritis (AA. Rats challenged to induce AA were treated with terbutaline (TERB, a β2-AR agonist (600 μg/kg/day and/or phentolamine (PHEN, an α-AR antagonist (5.0 mg/kg/day or vehicle from disease onset through severe disease. We report that in spleen, mesenteric (MLN and draining lymph node (DLN cells, TERB reduces proliferation, an effect independent of IL-2. TERB also fails to shift Th cytokines from a Th1 to Th2 profile in spleen and MLN (no effect on IFN-γ and DLN (greater IFN-γ cells. In splenocytes, TERB, PHEN and co-treatment (PT promotes an anti-inflammatory profile (greater IL-10 and lowers TNF-α (PT only. In DLN cells, drug treatments do not affect inflammatory profiles, except PT, which raised IL-10. In MLN cells, TERB or PHEN lowers MLN cell secretion of TNF-α or IL-10, respectively. Collectively, our findings indicate disrupted β2-AR, but not α-AR signaling in AA. Aberrant β2-AR signaling consequently derails the sympathetic regulation of lymphocyte expansion, Th cell differentiation, and inflammation in the spleen, DLNs and MLNs that is required for immune system homeostasis. Importantly, this study provides potential mechanisms through which reestablished balance between α- and β2-AR function in the immune system ameliorates inflammation and joint

  11. Athero-inflammatory nanotherapeutics: Ferulic acid-based poly(anhydride-ester) nanoparticles attenuate foam cell formation by regulating macrophage lipogenesis and reactive oxygen species generation.

    Science.gov (United States)

    Chmielowski, Rebecca A; Abdelhamid, Dalia S; Faig, Jonathan J; Petersen, Latrisha K; Gardner, Carol R; Uhrich, Kathryn E; Joseph, Laurie B; Moghe, Prabhas V

    2017-07-15

    Enhanced bioactive anti-oxidant formulations are critical for treatment of inflammatory diseases, such as atherosclerosis. A hallmark of early atherosclerosis is the uptake of oxidized low density lipoprotein (oxLDL) by macrophages, which results in foam cell and plaque formation in the arterial wall. The hypolipidemic, anti-inflammatory, and antioxidative properties of polyphenol compounds make them attractive targets for treatment of atherosclerosis. However, high concentrations of antioxidants can reverse their anti-atheroprotective properties and cause oxidative stress within the artery. Here, we designed a new class of nanoparticles with anti-oxidant polymer cores and shells comprised of scavenger receptor targeting amphiphilic macromolecules (AMs). Specifically, we designed ferulic acid-based poly(anhydride-ester) nanoparticles to counteract the uptake of high levels of oxLDL and regulate reactive oxygen species generation (ROS) in human monocyte derived macrophages (HMDMs). Compared to all compositions examined, nanoparticles with core ferulic acid-based polymers linked by diglycolic acid (PFAG) showed the greatest inhibition of oxLDL uptake. At high oxLDL concentrations, the ferulic acid diacids and polymer nanoparticles displayed similar oxLDL uptake. Treatment with the PFAG nanoparticles downregulated the expression of macrophage scavenger receptors, CD-36, MSR-1, and LOX-1 by about 20-50%, one of the causal factors for the decrease in oxLDL uptake. The PFAG nanoparticle lowered ROS production by HMDMs, which is important for maintaining macrophage growth and prevention of apoptosis. Based on these results, we propose that ferulic acid-based poly(anhydride ester) nanoparticles may offer an integrative strategy for the localized passivation of the early stages of the atheroinflammatory cascade in cardiovascular disease. Future development of anti-oxidant formulations for atherosclerosis applications is essential to deliver an efficacious dose while

  12. Inhibitory effects of diallyl disulfide on the production of inflammatory mediators and cytokines in lipopolysaccharide-activated BV2 microglia

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hye Young [Department of Biochemistry, Dongeui University College of Oriental Medicine, Busan 614-714 (Korea, Republic of); Department of Pharmacy, Pusan National University, Busan 609-735 (Korea, Republic of); Kim, Nam Deuk [Department of Pharmacy, Pusan National University, Busan 609-735 (Korea, Republic of); Kim, Gi-Young [Department of Marine Life Sciences, Jeju National University, Jeju 690-756 (Korea, Republic of); Hwang, Hye Jin [Anti-Aging Research Center and Blue-Bio Industry RIC, Dongeui University, Busan 614-714 (Korea, Republic of); Department of Food and Nutrition, College of Human Ecology, Dongeui University, Busan 614-714 (Korea, Republic of); Kim, Byung-Woo [Anti-Aging Research Center and Blue-Bio Industry RIC, Dongeui University, Busan 614-714 (Korea, Republic of); Department of Life Science and Biotechnology, College of Natural Science, Dongeui University, Busan 614-714 (Korea, Republic of); Department of Biomaterial Control, Graduate School, Dongeui University, Busan 614-714 (Korea, Republic of); Kim, Wun Jae [Department of Urology, College of Medicine, Chungbuk National University, Cheongju, Chungbuk 361-763 (Korea, Republic of); Choi, Yung Hyun, E-mail: choiyh@deu.ac.kr [Department of Biochemistry, Dongeui University College of Oriental Medicine, Busan 614-714 (Korea, Republic of); Anti-Aging Research Center and Blue-Bio Industry RIC, Dongeui University, Busan 614-714 (Korea, Republic of); Department of Biomaterial Control, Graduate School, Dongeui University, Busan 614-714 (Korea, Republic of)

    2012-07-15

    Diallyl disulfide (DADS), a main organosulfur component responsible for the diverse biological effects of garlic, displays a wide variety of internal biological activities. However, the cellular and molecular mechanisms underlying DADS' anti-inflammatory activity remain poorly understood. In this study, therefore, the anti-inflammatory effects of DADS were studied to investigate its potential therapeutic effects in lipopolysaccharide (LPS)-stimulated BV2 microglia. We found that pretreatment with DADS prior to treatment with LPS significantly inhibited excessive production of nitric oxide (NO) and prostaglandin E{sub 2} (PGE{sub 2}) in a dose-dependent manner. The inhibition was associated with down-regulation of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression. DADS also attenuated the production of pro-inflammatory cytokines and chemokines, including interleukin-1β (IL-1β), tumor necrosis factor (TNF)-α, and monocyte chemoattractant protein-1 (MCP-1) by suppressing the expression of mRNAs for these proteins. The mechanism underlying this protective effect might be related to the inhibition of nuclear factor-kappaB, Akt and mitogen-activated protein kinase signaling pathway activation in LPS-stimulated microglial cells. These findings indicated that DADS is potentially a novel therapeutic candidate for the treatment of various neurodegenerative diseases. -- Highlights: ► DADS attenuates production of NO and PGE2 in LPS-activated BV2 microglia. ► DADS downregulates levels of iNOS and COX-2. ► DADS inhibits production and expression of inflammatory cytokines and chemokine. ► DADS exhibits these effects by suppression of NF-κB, PI3K/Akt and MAPKs pathways.

  13. Human Neural Stem Cell Transplantation-Mediated Alteration of Microglial/Macrophage Phenotypes after Traumatic Brain Injury.

    Science.gov (United States)

    Gao, Junling; Grill, Raymond J; Dunn, Tiffany J; Bedi, Supinder; Labastida, Javier Allende; Hetz, Robert A; Xue, Hasen; Thonhoff, Jason R; DeWitt, Douglas S; Prough, Donald S; Cox, Charles S; Wu, Ping

    2016-10-01

    Neural stem cells (NSCs) promote recovery from brain trauma, but neuronal replacement is unlikely the sole underlying mechanism. We hypothesize that grafted NSCs enhance neural repair at least partially through modulating the host immune response after traumatic brain injury (TBI). C57BL/6 mice were intracerebrally injected with primed human NSCs (hNSCs) or vehicle 24 h after a severe controlled cortical impact injury. Six days after transplantation, brain tissues were collected for Western blot and immunohistochemical analyses. Observations included indicators of microglia/macrophage activation, M1 and M2 phenotypes, axonal injury detected by amyloid precursor protein (APP), lesion size, and the fate of grafted hNSCs. Animals receiving hNSC transplantation did not show significant decreases of brain lesion volumes compared to transplantation procedures with vehicle alone, but did show significantly reduced injury-dependent accumulation of APP. Furthermore, intracerebral transplantation of hNSCs reduced microglial activation as shown by a diminished intensity of Iba1 immunostaining and a transition of microglia/macrophages toward the M2 anti-inflammatory phenotype. The latter was represented by an increase in the brain M2/M1 ratio and increases of M2 microglial proteins. These phenotypic switches were accompanied by the increased expression of anti-inflammatory interleukin-4 receptor α and decreased proinflammatory interferon-γ receptor β. Finally, grafted hNSCs mainly differentiated into neurons and were phagocytized by either M1 or M2 microglia/macrophages. Thus, intracerebral transplantation of primed hNSCs efficiently leads host microglia/macrophages toward an anti-inflammatory phenotype that presumably contributes to stem cell-mediated neuroprotective effects after severe TBI in mice.

  14. Role of Microglial M1/M2 Polarization in Relapse and Remission of Psychiatric Disorders and Diseases

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    Yutaka Nakagawa

    2014-11-01

    Full Text Available Psychiatric disorders such as schizophrenia and major depressive disorder were thought to be caused by neurotransmitter abnormalities. Patients with these disorders often experience relapse and remission; however the underlying molecular mechanisms of relapse and remission still remain unclear. Recent advanced immunological analyses have revealed that M1/M2 polarization of macrophages plays an important role in controlling the balance between promotion and suppression in inflammation. Microglial cells share certain characteristics with macrophages and contribute to immune-surveillance in the central nervous system (CNS. In this review, we summarize immunoregulatory functions of microglia and discuss a possible role of microglial M1/M2 polarization in relapse and remission of psychiatric disorders and diseases. M1 polarized microglia can produce pro-inflammatory cytokines, reactive oxygen species, and nitric oxide, suggesting that these molecules contribute to dysfunction of neural network in the CNS. Alternatively, M2 polarized microglia express cytokines and receptors that are implicated in inhibiting inflammation and restoring homeostasis. Based on these aspects, we propose a possibility that M1 and M2 microglia are related to relapse and remission, respectively in psychiatric disorders and diseases. Consequently, a target molecule skewing M2 polarization of microglia may provide beneficial therapies for these disorders and diseases in the CNS.

  15. Genistein suppresses Prevotella intermedia lipopolysaccharide-induced inflammatory response in macrophages and attenuates alveolar bone loss in ligature-induced periodontitis.

    Science.gov (United States)

    Choi, Eun-Young; Bae, Seung Han; Ha, Min Hee; Choe, So-Hui; Hyeon, Jin-Yi; Choi, Jeom-Il; Choi, In Soon; Kim, Sung-Jo

    2016-02-01

    Genistein is a major isoflavone subclass of flavonoids found in soybean and a potent tyrosine kinase inhibitor. The present study aimed to assess the effect of genistein on the production of proinflammatory mediators in murine macrophages stimulated with lipopolysaccharide (LPS) isolated from Prevotella intermedia, a pathogen associated with different forms of periodontal disease, and to evaluate its possible influence on alveolar bone loss in ligature-induced periodontitis using micro-computed tomography (micro-CT) analysis as well. LPS was isolated from P. intermedia ATCC 25611 by using the standard hot phenol-water method. Culture supernatants were analyzed for nitric oxide (NO) and interleukin-6 (IL-6). Inducible NO synthase (iNOS) protein expression was evaluated by immunoblot analysis. Real-time PCR was carried out to measure iNOS and IL-6 mRNA expression. In addition, effect of genistein on alveolar bone loss was evaluated in a rat model of experimental periodontitis using micro-CT analysis. Genistein significantly attenuated P. intermedia LPS-induced production of iNOS-derived NO and IL-6 with attendant decrease in their mRNA expression in RAW264.7 cells. In addition, when genistein was administered to rats, decreases in alveolar bone height and bone volume fraction induced by ligature placement were significantly inhibited. Genistein administration also prevented ligature-induced alterations in the microstructural parameters of trabecular bone, including trabecular thickness, trabecular separation, bone mineral density and structure model index. While additional studies are required, we suggest that genistein could be utilized for the therapy of human periodontitis in the future. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Histone Demethylase JMJD2A Inhibition Attenuates Neointimal Hyperplasia in the Carotid Arteries of Balloon-Injured Diabetic Rats via Transcriptional Silencing: Inflammatory Gene Expression in Vascular Smooth Muscle Cells

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    Hu Qi

    2015-09-01

    Full Text Available Background/Aims: Diabetic patients suffer from severe neointimal hyperplasia following angioplasty. The epigenetic abnormalities are increasingly considered to be relevant to the pathogenesis of diabetic cardiovascular complications. But the epigenetic mechanisms linking diabetes and coronary restenosis have not been fully elucidated. In this study, we explored the protective effect and underlying mechanisms of demethylases JMJD2A inhibition in balloon-injury induced neointimal formation in diabetic rats. Methods: JMJD2A inhibition was achieved by the chemical inhibitor 2,4-pyridinedicarboxylic acid (2,4-PDCA and small interfering RNA (siRNA. In vitro, we investigated the proliferation, migration and inflammation of rat vascular smooth muscle cells (VSMCs in response to high glucose (HG. In vivo, diabetic rats induced using high-fat diet and low-dose streptozotocin (35mg/kg underwent carotid artery balloon injury. Morphometric analysis was performed using hematein eosin and immumohistochemical staining. Chromatin Immunoprecipitation (ChIP was conducted to detect modification of H3K9me3 at inflammatory genes promoters. Results: The global JMJD2A was increased in HG-stimulated VSMCs and balloon-injured arteries of diabetic rats, accompanied by decreased H3K9me3. The inhibition of JMJD2A suppressed VSMCs proliferation, migration and inflammation induced by high glucose (HG in vitro. And JMJDA2A inhibition attenuated neointimal formation in balloon-injured diabetic rats. The underlying mechanisms were relevant to the restoration of H3K9me3 levels at the promoters of MCP-1 and IL-6, and then the suppressed expression of MCP-1 and IL-6. Conclusion: The JMJD2A inhibition significantly attenuated neointimal formation in balloon injured diabetic rats via the suppression of VSMCs proliferation, migration, and inflammation by restoring H3K9me3.

  17. 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

  18. 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.

  19. IFNgamma enhances microglial reactions to hippocampal axonal degeneration

    DEFF Research Database (Denmark)

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

    2000-01-01

    Glial reactivity is implicated in CNS repair and regenerative responses. Microglia, the cells responding earliest to axonal injury, produce tumor necrosis factor-alpha (TNFalpha), a cytokine with both cytopathic and neuroprotective effects. We have studied activation of hippocampal microglia...... 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...

  20. CP-25 attenuates the inflammatory response of fibroblast-like synoviocytes co-cultured with BAFF-activated CD4(+) T cells.

    Science.gov (United States)

    Jia, Xiaoyi; Wei, Fang; Sun, Xiaojing; Chang, Yan; Xu, Shu; Yang, Xuezhi; Wang, Chun; Wei, Wei

    2016-08-02

    Total glucosides of paeony (TGP) is the first anti-inflammatory immune regulatory drug approved for the treatment of rheumatoid arthritis in China. A novel compound, paeoniflorin-6'-O-benzene sulfonate (code CP-25), comes from the structural modification of paeoniflorin (Pae), which is the effective active ingredient of TGP. The aim of the present study is to investigate the effect of CP-25 on adjuvant arthritis (AA) fibroblast-like synoviocytes (FLS) co-cultured with BAFF-activated CD4(+) T cells and the expression of BAFF-R in CD4(+) T cells. The mRNA expression of BAFF and its receptors was assessed by qPCR. The expression of BAFF receptors in CD4(+) T cells was analyzed by flow cytometry. The effect of CP-25 on AA rats was evaluated by their joint histopathology. The cell culture growth of thymocytes and FLS was detected by cell counting kit (CCK-8). The concentrations of IL-1β, TNF-α, and IL-6 were measured by Enzyme-linked immunosorbent assay (ELISA). The mRNA expression levels of BAFF and BAFF-R were enhanced in the mesenteric lymph nodes of AA rats, TACI expression was reduced, and BCMA had no change. The expression of BAFF-R in CD4(+) T cells was also enhanced. CP-25 alleviated the joint histopathology and decreased the expression of BAFF-R in CD4(+) T cells from AA rats in vivo. In vitro, CP-25 inhibited the abnormal cell culture growth of BAFF-stimulated thymocytes and FLS. In the co-culture system, IL-1β, IL-6 and TNF-α production was enhanced by FLS co-cultured with BAFF-activated CD4(+) T cells. Moreover, BAFF-stimulated CD4(+) T cells promoted the cell culture growth of FLS. The addition of CP-25 decreased the expression of BAFF-R in CD4(+) T cells and inhibited the cell culture growth and cytokine secretion ability of FLS co-cultured with BAFF-activated CD4(+) T cells. The present study indicates that CP-25 may repress the cell culture growth and cytokine secretion ability of FLS, and its inhibitory effects might be associated with its ability

  1. LED enhances anti-inflammatory effect ofluteolin (3',4',5,7-tetrahydroxyflavone) in vitro.

    Science.gov (United States)

    Fan, Shengnuo; Habib, Ahsan; Liu, Jun; Tan, Jun

    2018-01-01

    Neuroinflammation is a complex pathological process usually results from abnormal microglial activation, thus, intervention in a microglial stimulation pathway could be a promising approach for the treatment of neurodegenerative diseases. Luteolin is an important bioflavonoid possesses anti-inflammatory properties, which is widely studied over these years. Light emitting diode (LED) therapy is reported to be a potential therapeutic strategy for many diseases including neurodegenerative diseases. However, little is known about the anti-inflammatory effect of LED therapy on activated microglial cells, even less is known whether there is a synergistic anti-inflammatory effect exist in LED and luteolin therapy. In this study, we aimed to confirm the anti-inflammatory effect of luteolin and LED combination therapy in lipopolysaccharide (LPS)-stimulated BV2 microglial cells. We showed that luteolin inhibited LPS-induced cytotoxicity, tumor necrosis factor alpha (TNFα) and interleukin-6 (IL-6) production through modulation of p38 and extracellular signal-regulated kinase (ERK) signaling in BV2 cells. In addition, LED therapy enhanced the anti-inflammatory effect of luteolin. These results suggest that a synergistic effect between luteolin and LED could be a new effective therapy in relieving neuroinflammation.

  2. Microglial priming and enhanced reactivity to secondary insult in aging, and traumatic CNS injury, and neurodegenerative disease.

    Science.gov (United States)

    Norden, Diana M; Muccigrosso, Megan M; Godbout, Jonathan P

    2015-09-01

    Glia of the central nervous system (CNS) help to maintain homeostasis in the brain and support efficient neuronal function. Microglia are innate immune cells of the brain that mediate responses to pathogens and injury. They have key roles in phagocytic clearing, surveying the local microenvironment and propagating inflammatory signals. An interruption in homeostasis induces a cascade of conserved adaptive responses in glia. This response involves biochemical, physiological and morphological changes and is associated with the production of cytokines and secondary mediators that influence synaptic plasticity, cognition and behavior. This reorganization of host priorities represents a beneficial response that is normally adaptive but may become maladaptive when the profile of microglia is compromised. For instance, microglia can develop a primed or pro-inflammatory mRNA, protein and morphological profile with aging, traumatic brain injury and neurodegenerative disease. As a result, primed microglia exhibit an exaggerated inflammatory response to secondary and sub-threshold challenges. Consequences of exaggerated inflammatory responses by microglia include the development of cognitive deficits, impaired synaptic plasticity and accelerated neurodegeneration. Moreover, impairments in regulatory systems in these circumstances may make microglia more resistant to negative feedback and important functions of glia can become compromised and dysfunctional. Overall, the purpose of this review is to discuss key concepts of microglial priming and immune-reactivity in the context of aging, traumatic CNS injury and neurodegenerative disease. This article is part of a Special Issue entitled 'Neuroimmunology and Synaptic Function'. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Microglial dysfunction as a key pathological change in adrenomyeloneuropathy.

    Science.gov (United States)

    Gong, Yi; Sasidharan, Nikhil; Laheji, Fiza; Frosch, Matthew; Musolino, Patricia; Tanzi, Rudy; Kim, Doo Yeon; Biffi, Alessandra; El Khoury, Joseph; Eichler, Florian

    2017-11-01

    Mutations in ABCD1 cause the neurodegenerative disease, adrenoleukodystrophy, which manifests as the spinal cord axonopathy adrenomyeloneuropathy (AMN) in nearly all males surviving into adulthood. Microglial dysfunction has long been implicated in pathogenesis of brain disease, but its role in the spinal cord is unclear. We assessed spinal cord microglia in humans and mice with AMN and investigated the role of ABCD1 in microglial activity toward neuronal phagocytosis in cell culture. Because mutations in ABCD1 lead to incorporation of very-long-chain fatty acids into phospholipids, we separately examined the effects of lysophosphatidylcholine (LPC) upon microglia. Within the spinal cord of humans and mice with AMN, upregulation of several phagocytosis-related markers, such as MFGE8 and TREM2, precedes complement activation and synapse loss. Unexpectedly, this occurs in the absence of overt inflammation. LPC C26:0 added to ABCD1-deficient microglia in culture further enhances MFGE8 expression, aggravates phagocytosis, and leads to neuronal injury. Furthermore, exposure to a MFGE8-blocking antibody reduces phagocytic activity. Spinal cord microglia lacking ABCD1 are primed for phagocytosis, affecting neurons within an altered metabolic milieu. Blocking phagocytosis or specific phagocytic receptors may alleviate synapse loss and axonal degeneration. Ann Neurol 2017;82:813-827. © 2017 The Authors Annals of Neurology published by Wiley Periodicals, Inc. on behalf of American Neurological Association.

  4. 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.

  5. Tff3 is Expressed in Neurons and Microglial Cells

    Directory of Open Access Journals (Sweden)

    Ting Fu

    2014-11-01

    Full Text Available Background/Aims: The trefoil factor family (TFF peptide TFF3 is typically secreted by mucous epithelia, but is also expressed in the immune system and the brain. It was the aim of this study to determine the cerebral cell types which express Tff3. Methods: Primary cultures from rat embryonic or neonatal cerebral cortex and hippocampus, respectively, were studied by means of RT-PCR and immunofluorescence. Moreover, Tff3 expression was localized by immunocytochemistry in sections of adult rat cerebellum. Results: Tff3 transcripts were detectable in neural cultures of both the cortex and the hippocampus as well as in glial cell-enriched cultures. Tff3 peptide co-localized with Map2 indicating an expression in neurons in vitro. The neuronal expression was confirmed by immunofluorescence studies of adult rat cerebellum. Furthermore, Tff3 peptide showed also a clear co-localization with Iba-1 in vitro typical of activated microglial cells. Conclusion: The neuronal expression of Tff3 is in line with a function of a typical neuropeptide influencing, e.g., fear, memory, depression and motoric skills. The expression in activated microglial cells, which is demonstrated here for the first time, points towards a possible function for Tff3 in immune reactions in the CNS. This opens a plethora of additional possible functions for Tff3 including synaptic plasticity and cognition as well as during neuroinflammatory diseases and psychiatric disorders.

  6. Microglial activation underlies cerebellar deficits produced by repeated cannabis exposure.

    Science.gov (United States)

    Cutando, Laura; Busquets-Garcia, Arnau; Puighermanal, Emma; Gomis-González, Maria; Delgado-García, José María; Gruart, Agnès; Maldonado, Rafael; Ozaita, Andrés

    2013-07-01

    Chronic cannabis exposure can lead to cerebellar dysfunction in humans, but the neurobiological mechanisms involved remain incompletely understood. Here, we found that in mice, subchronic administration of the psychoactive component of cannabis, delta9-tetrahydrocannabinol (THC), activated cerebellar microglia and increased the expression of neuroinflammatory markers, including IL-1β. This neuroinflammatory phenotype correlated with deficits in cerebellar conditioned learning and fine motor coordination. The neuroinflammatory phenotype was readily detectable in the cerebellum of mice with global loss of the CB1 cannabinoid receptor (CB1R, Cb1(-/-) mice) and in mice lacking CB1R in the cerebellar parallel fibers, suggesting that CB1R downregulation in the cerebellar molecular layer plays a key role in THC-induced cerebellar deficits. Expression of CB2 cannabinoid receptor (CB2R) and Il1b mRNA was increased under neuroinflammatory conditions in activated CD11b-positive microglial cells. Furthermore, administration of the immunosuppressant minocycline or an inhibitor of IL-1β receptor signaling prevented the deficits in cerebellar function in Cb1(-/-) and THC-withdrawn mice. Our results suggest that cerebellar microglial activation plays a crucial role in the cerebellar deficits induced by repeated cannabis exposure.

  7. Carvedilol abrogates hypoxia-induced oxidative stress and neuroinflammation in microglial BV2 cells.

    Science.gov (United States)

    Gao, Xiujuan; Wu, Bin; Fu, Zhijian; Zhang, Zongwang; Xu, Guangjun

    2017-11-05

    Microglia initially undergo rapid activation in response to injury and stressful stimuli, such as hypoxia. Oxidative stress and the inflammatory response play critical roles in hypoxic-ischemic brain injury. Carvedilol is a β-blocker used to treat high blood pressure and heart failure. In this study, we investigated whether carvedilol had a protective effect against hypoxia-induced oxidative stress and inflammation in microglial BV2 cells. Our results indicate that hypoxic exposure significantly reduced mean cell viability of BV2 microglia, which was significantly restored by carvedilol (10 and 50μM). In addition, carvedilol treatment significantly inhibited the hypoxia-induced increase in reactive oxygen species (ROS) and 4-hydroxy-2-nonenal (4-HNE). Administration of carvedilol significantly inhibited expression of IL-1β, TNF-α, and IL-6 at both the mRNA and protein levels. Mechanistically, we found that hypoxia significantly increased phosphorylation of IKK, IκBα, and NF-κB p65. However, treatment with carvedilol inhibited phosphorylation of these molecules. Notably, hypoxia resulted in a significant nuclear translocation of NF-κB p65, which was inhibited by administration of carvedilol. Luciferase reporter assay results demonstrate that treatment with carvedilol inhibited the hypoxia-induced increase in NF-κB binding activity. These data suggest that carvedilol may be of potential use as a novel therapy against hypoxia or ischemia. Copyright © 2017. Published by Elsevier B.V.

  8. 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.

  9. Interaction of inflammatory and anti-inflammatory responses in microglia by Staphylococcus aureus-derived lipoteichoic acid

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    Huang, Bor-Ren [Department of Neurosurgery, Buddhist Tzu Chi General Hospital, Taichung Branch, Taichung, Taiwan (China); Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan (China); Tsai, Cheng-Fang [Department of Biotechnology, Asia University, Taichung, Taiwan (China); Lin, Hsiao-Yun [Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan (China); Tseng, Wen-Pei [Graduate Institute of Sports and Health, National Changhua University of Education, Changhua County, Taiwan (China); Huang, Shiang-Suo [Department of Pharmacology and Institute of Medicine, College of Medicine, Chung Shan Medical University, Taiwan (China); Wu, Chi-Rei [Graduate Institute of Chinese Pharmaceutical Sciences, College of Pharmacy, China Medical University, Taiwan (China); Lin, Chingju [Department of Physiology, School of Medicine, China Medical University, Taichung, Taiwan (China); Yeh, Wei-Lan [Cancer Research Center, Department of Medical Research, Changhua Christian Hospital, Changhua, Taiwan (China); Lu, Dah-Yuu, E-mail: dahyuu@mail.cmu.edu.tw [Graduate Institute of Neural and Cognitive Sciences, China Medical University, Taichung, Taiwan (China)

    2013-05-15

    We investigated the interaction between proinflammatory and inflammatory responses caused by Staphylococcus aureus-derived lipoteichoic acid (LTA) in primary cultured microglial cells and BV-2 microglia. LTA induced inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein levels increase in a concentration- and time-dependent manner. Meanwhile, LTA also increased nitric oxide (NO) and PGE{sub 2} production in microglia. Administration of TLR2 antagonist effectively inhibited LTA-induced NO, iNOS, and COX-2 expression. Moreover, treatment of cells with LTA caused a time-dependent activation of ERK, p38, JNK, as well as AKT. We also found that LTA-induced iNOS and COX-2 up-regulation were attenuated by p38, JNK, and PI3-kinase inhibitors. On the other hand, LTA-enhanced HO-1 expression was attenuated by p38 and PI3-kinase inhibitors. Treatment of cells with NF-κB and AP-1 inhibitors antagonized LTA-induced iNOS and COX-2 expression. However, only NF-κB inhibitors reduced LTA-induced HO-1 expression in microglia. Furthermore, stimulation of cells with LTA also activated IκBα phosphorylation, p65 phosphorylation at Ser{sup 536}, and c-Jun phosphorylation. Moreover, LTA-induced increases of κB-DNA and AP-1-DNA binding activity were inhibited by p38, JNK, and PI3-kinase inhibitors. HO-1 activator CoPP IX dramatically reversed LTA-induced iNOS expression. Our results provided mechanisms linking LTA and inflammation/anti-inflammation, and indicated that LTA plays a regulatory role in microglia activation. - Highlights: • LTA causes an increase in iNOS, COX-2, and HO-1 expression in microglia. • LTA induces iNOS and COX-2 expression through TLR-2/NF-κB and AP-1 pathways. • HO-1 expression is regulated through p38, JNK, PI3K/AKT and AP-1 pathways. • Induced HO-1 reduces LTA-induced iNOS expression. • LTA plays a regulatory role on inflammatory/anti-inflammatory responses.

  10. Early systemic granulocyte-colony stimulating factor treatment attenuates neuropathic pain after peripheral nerve injury.

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    Po-Kuan Chao

    Full Text Available Recent studies have shown that opioid treatment can reduce pro-inflammatory cytokine production and counteract various neuropathic pain syndromes. Granulocyte colony-stimulating factor (G-CSF can promote immune cell differentiation by increasing leukocytes (mainly opioid-containing polymorphonuclear (PMN cells, suggesting a potential beneficial role in treating chronic pain. This study shows the effectiveness of exogenous G-CSF treatment (200 µg/kg for alleviating thermal hyperalgesia and mechanical allodynia in rats with chronic constriction injury (CCI, during post-operative days 1-25, compared to that of vehicle treatment. G-CSF also increases the recruitment of opioid-containing PMN cells into the injured nerve. After CCI, single administration of G-CSF on days 0, 1, and 2, but not on day 3, relieved thermal hyperalgesia, which indicated that its effect on neuropathic pain had a therapeutic window of 0-48 h after nerve injury. CCI led to an increase in the levels of interleukin-6 (IL-6 mRNA and tumor necrosis factor-α (TNF-α protein in the dorsal root ganglia (DRG. These high levels of IL-6 mRNA and TNF-α were suppressed by a single administration of G-CSF 48-144 h and 72-144 h after CCI, respectively. Furthermore, G-CSF administered 72-144 h after CCI suppressed the CCI-induced upregulation of microglial activation in the ipsilateral spinal dorsal horn, which is essential for sensing neuropathic pain. Moreover, the opioid receptor antagonist naloxone methiodide (NLXM reversed G-CSF-induced antinociception 3 days after CCI, suggesting that G-CSF alleviates hyperalgesia via opioid/opioid receptor interactions. These results suggest that an early single systemic injection of G-CSF alleviates neuropathic pain via activation of PMN cell-derived endogenous opioid secretion to activate opioid receptors in the injured nerve, downregulate IL-6 and TNF-α inflammatory cytokines, and attenuate microglial activation in the spinal dorsal horn. This

  11. Microglial activation is not equivalent to neuroinflammation in alcohol-induced neurodegeneration: The importance of microglia phenotype.

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    Marshall, S Alex; McClain, Justin A; Kelso, Matthew L; Hopkins, Deann M; Pauly, James R; Nixon, Kimberly

    2013-06-01

    Excessive alcohol intake, a defining characteristic of an alcohol use disorder (AUD), results in neurodegeneration in the hippocampus and entorhinal cortex that has been linked to a variety of cognitive deficits. Neuroinflammation is thought to be a factor in alcohol-induced neurodegeneration, and microglia activation is a key but not sole component of an inflammatory response. These experiments investigate the effects of ethanol exposure in a well-accepted model of an AUD on both microglial activation and blood brain barrier disruption (BBB) in order to understand their relationship to classical definitions of inflammation and alcohol-induced neurodegeneration. Following a four-day binge ethanol paradigm, rat hippocampal and entorhinal cortex tissue was examined using three distinct approaches to determine microglia phenotype and BBB disruption: immunohistochemistry, autoradiography, and ELISA. After ethanol exposure, there was an increase in [(3)H]-PK-11195 binding and OX-42 immunoreactivity indicative of microglial activation; however, microglia were not fully activated since both OX-6 and ED-1 immunoreactive microglia were absent. This data was supported by functional evidence as there was no increase in the proinflammatory cytokines IL-6 or TNF-α, but a 26% increase in the anti-inflammatory cytokine, IL-10, and a 38% increase in the growth factor, TGF-β, seven days after exposure. Furthermore, there was no evidence of a disruption of the BBB. These data suggest that the four-day binge model of an AUD, which produces neurodegeneration in corticolimbic regions, does not elicit classical neuroinflammation but instead produces partially activated microglia. Partial activation of microglia following binge ethanol exposure suggest that microglia in this model have beneficial or homeostatic roles rather than directly contributing to neurodegeneration and are a consequence of alcohol-induced-damage instead of the source of damage. Copyright © 2013 Elsevier Inc. All

  12. The induction of neuronal death by up-regulated microglial cathepsin H in LPS-induced neuroinflammation.

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    Fan, Kai; Li, Daobo; Zhang, Yanli; Han, Chao; Liang, Junjie; Hou, Changyi; Xiao, Hongliang; Ikenaka, Kazuhiro; Ma, Jianmei

    2015-03-19

    Neuroinflammation is a hallmark that leads to selective neuronal loss and/or dysfunction in neurodegenerative disorders. Microglia-derived lysosomal cathepsins are increasingly recognized as important inflammatory mediators to trigger signaling pathways that aggravate neuroinflammation. However, cathepsin H (Cat H), a cysteine protease, has been far less studied in neuroinflammation, compared to cathepsins B, D, L, and S. The expression patterns and functional roles of Cat H in the brain in neuroinflammation remain unknown. C57BL/6J mice were intraperitoneally injected with either 0.9% saline or lipopolysaccharide (LPS, 5 mg/kg). Immunohistochemistry (IHC) and in situ hybridization (ISH) were used to analyze expression and localization of Cat H in the brain. Nitrite assay was used to examine microglial activation in vitro; ELISA was used to determine the release of Cat H and proinflammatory cytokines (TNF-α, IL-1β, IL-6, IFN-γ). Cat H activity was analyzed by cellular Cat H assay kit. Flow cytometry and in situ cell death detection were used to investigate neuronal death. Data were evaluated for statistical significance with one-way ANOVA and t test. Cat H mRNA was only present in perivascular microglia and non-parenchymal sites under normal conditions. After LPS injection, Cat H mRNA expression in activated microglia in different brain regions was increased. Twenty-four hours after LPS injection, Cat H mRNA expression was maximal in SNr; 72 h later, it peaked in cerebral cortex and hippocampus then decreased and maintained at a low level. The expression of Cat H protein exhibited the similar alterations after LPS injection. In vitro, inflammatory stimulation (LPS, TNF-α, IL-1β, IL-6, and IFN-γ) increased the release and activity of Cat H in microglia. Conversely, addition of Cat H to microglia promoted the production and release of NO, IL-1β, and IFN-γ which could be prevented by neutralizing antibody. Further, addition of Cat H to Neuro2a cells induced

  13. Anti-inflammatory effects of sargachromenol-rich ethanolic extract of Myagropsis myagroides on lipopolysaccharide-stimulated BV-2 cells.

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    Kim, Sunghee; Lee, Min-Sup; Lee, Bonggi; Gwon, Wi-Gyeong; Joung, Eun-Ji; Yoon, Na-Young; Kim, Hyeung-Rak

    2014-07-09

    Excessive pro-inflammatory cytokine production from activated microglia contributes to neurodegenerative diseases, thus, microglial inactivation may delay the progress of neurodegeneration by attenuating the neuroinflammation. Among 5 selected brown algae, we found the highest antioxidant and anti-neuroinflammatory activities from Myagropsis myagroides ethanolic extract (MME) in lipopolysaccharide (LPS)-stimulated BV-2 cells. The levels of nitric oxide (NO), prostaglandin E2 (PGE2), and pro-inflammatory cytokines were measured by Griess assay and enzyme linked immunesorbent assay. The levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), mitogen-activated protein kinases (MAPKs), and Akt were measured using Western blot. Nuclear translocation and transcriptional activation of nuclear factor-κB (NF-κB) were determined by immunefluorescence and reporter gene assay, respectively. MME inhibited the expression of iNOS and COX-2 at mRNA and protein levels, resulting in reduction of NO and PGE2 production. As a result, pro-inflammatory cytokines were reduced by MME. MME also inhibited the activation and translocation of NF-κB by preventing inhibitor κB-α (IκB-α) degradation. Moreover, MME inhibited the phosphorylation of extracellular signal regulated kinases (ERKs) and c-Jun N-terminal kinases (JNKs). Main anti-inflammatory compound in MME was identified as sargachromenol by NMR spectroscopy. These results indicate that the anti-inflammatory effect of sargachromenol-rich MME on LPS-stimulated microglia is mainly regulated by the inhibition of IκB-α/NF-κB and ERK/JNK pathways.

  14. Anti-inflammatory and anti-amyloidogenic effects of a small molecule, 2,4-bis(p-hydroxyphenyl-2-butenal in Tg2576 Alzheimer’s disease mice model

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    Jin Peng

    2013-01-01

    Full Text Available Abstract Background Alzheimer’s disease (AD is pathologically characterized by excessive accumulation of amyloid-beta (Aβ fibrils within the brain and activation of astrocytes and microglial cells. In this study, we examined anti-inflammatory and anti-amyloidogenic effects of 2,4-bis(p-hydroxyphenyl-2-butenal (HPB242, an anti-inflammatory compound produced by the tyrosine-fructose Maillard reaction. Methods 12-month-old Tg2576 mice were treated with HPB242 (5 mg/kg for 1 month and then cognitive function was assessed by the Morris water maze test and passive avoidance test. In addition, western blot analysis, Gel electromobility shift assay, immunostaining, immunofluorescence staining, ELISA and enzyme activity assays were used to examine the degree of Aβ deposition in the brains of Tg2576 mice. The Morris water maze task was analyzed using two-way ANOVA with repeated measures. Otherwise were analyzed by one-way ANOVA followed by Dunnett’s post hoc test. Results Treatment of HPB242 (5 mg/kg for 1 month significantly attenuated cognitive impairments in Tg2576 transgenic mice. HPB242 also prevented amyloidogenesis in Tg2576 transgenic mice brains. This can be evidenced by Aβ accumulation, BACE1, APP and C99 expression and β-secretase activity. In addition, HPB242 suppresses the expression of inducible nitric oxide synthase (iNOS and cyclooxygenase-2 (COX-2 as well as activation of astrocytes and microglial cells. Furthermore, activation of nuclear factor-kappaB (NF-κB and signal transducer and activator of transcription 1/3 (STAT1/3 in the brain was potently inhibited by HPB242. Conclusions Thus, these results suggest that HPB242 might be useful to intervene in development or progression of neurodegeneration in AD through its anti-inflammatory and anti-amyloidogenic effects.

  15. Deep brain stimulation during early adolescence prevents microglial alterations in a model of maternal immune activation.

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    Hadar, Ravit; Dong, Le; Del-Valle-Anton, Lucia; Guneykaya, Dilansu; Voget, Mareike; Edemann-Callesen, Henriette; Schweibold, Regina; Djodari-Irani, Anais; Goetz, Thomas; Ewing, Samuel; Kettenmann, Helmut; Wolf, Susanne A; Winter, Christine

    2017-07-01

    In recent years schizophrenia has been recognized as a neurodevelopmental disorder likely involving a perinatal insult progressively affecting brain development. The poly I:C maternal immune activation (MIA) rodent model is considered as a neurodevelopmental model of schizophrenia. Using this model we and others demonstrated the association between neuroinflammation in the form of altered microglia and a schizophrenia-like endophenotype. Therapeutic intervention using the anti-inflammatory drug minocycline affected altered microglia activation and was successful in the adult offspring. However, less is known about the effect of preventive therapeutic strategies on microglia properties. Previously we found that deep brain stimulation of the medial prefrontal cortex applied pre-symptomatically to adolescence MIA rats prevented the manifestation of behavioral and structural deficits in adult rats. We here studied the effects of deep brain stimulation during adolescence on microglia properties in adulthood. We found that in the hippocampus and nucleus accumbens, but not in the medial prefrontal cortex, microglial density and soma size were increased in MIA rats. Pro-inflammatory cytokine mRNA was unchanged in all brain areas before and after implantation and stimulation. Stimulation of either the medial prefrontal cortex or the nucleus accumbens normalized microglia density and soma size in main projection areas including the hippocampus and in the area around the electrode implantation. We conclude that in parallel to an alleviation of the symptoms in the rat MIA model, deep brain stimulation has the potential to prevent the neuroinflammatory component in this disease. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Cannabinoid-mediated modulation of neuropathic pain and microglial accumulation in a model of murine type I diabetic peripheral neuropathic pain

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    Ellis Connie L

    2010-03-01

    Full Text Available Abstract Background Despite the frequency of diabetes mellitus and its relationship to diabetic peripheral neuropathy (DPN and neuropathic pain (NeP, our understanding of underlying mechanisms leading to chronic pain in diabetes remains poor. Recent evidence has demonstated a prominent role of microglial cells in neuropathic pain states. One potential therapeutic option gaining clinical acceptance is the cannabinoids, for which cannabinoid receptors (CB are expressed on neurons and microglia. We studied the accumulation and activation of spinal and thalamic microglia in streptozotocin (STZ-diabetic CD1 mice and the impact of cannabinoid receptor agonism/antagonism during the development of a chronic NeP state. We provided either intranasal or intraperitoneal cannabinoid agonists/antagonists at multiple doses both at the initiation of diabetes as well as after establishment of diabetes and its related NeP state. Results Tactile allodynia and thermal hypersensitivity were observed over 8 months in diabetic mice without intervention. Microglial density increases were seen in the dorsal spinal cord and in thalamic nuclei and were accompanied by elevation of phosphorylated p38 MAPK, a marker of microglial activation. When initiated coincidentally with diabetes, moderate-high doses of intranasal cannabidiol (cannaboid receptor 2 agonist and intraperitoneal cannabidiol attenuated the development of an NeP state, even after their discontinuation and without modification of the diabetic state. Cannabidiol was also associated with restriction in elevation of microglial density in the dorsal spinal cord and elevation in phosphorylated p38 MAPK. When initiated in an established DPN NeP state, both CB1 and CB2 agonists demonstrated an antinociceptive effect until their discontinuation. There were no pronociceptive effects demonstated for either CB1 or CB2 antagonists. Conclusions The prevention of microglial accumulation and activation in the dorsal spinal

  17. Mechanisms Underlying Interferon-γ-Induced Priming of Microglial Reactive Oxygen Species Production.

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    Nicholas G Spencer

    Full Text Available Microglial priming and enhanced reactivity to secondary insults cause substantial neuronal damage and are hallmarks of brain aging, traumatic brain injury and neurodegenerative diseases. It is, thus, of particular interest to identify mechanisms involved in microglial priming. Here, we demonstrate that priming of microglia with interferon-γ (IFN γ substantially enhanced production of reactive oxygen species (ROS following stimulation of microglia with ATP. Priming of microglial ROS production was substantially reduced by inhibition of p38 MAPK activity with SB203580, by increases in intracellular glutathione levels with N-Acetyl-L-cysteine, by blockade of NADPH oxidase subunit NOX2 activity with gp91ds-tat or by inhibition of nitric oxide production with L-NAME. Together, our data indicate that priming of microglial ROS production involves reduction of intracellular glutathione levels, upregulation of NADPH oxidase subunit NOX2 and increases in nitric oxide production, and suggest that these simultaneously occurring processes result in enhanced production of neurotoxic peroxynitrite. Furthermore, IFNγ-induced priming of microglial ROS production was reduced upon blockade of Kir2.1 inward rectifier K+ channels with ML133. Inhibitory effects of ML133 on microglial priming were mediated via regulation of intracellular glutathione levels and nitric oxide production. These data suggest that microglial Kir2.1 channels may represent novel therapeutic targets to inhibit excessive ROS production by primed microglia in brain pathology.

  18. Patterns of Microglial Cell Activation in Alzheimer Disease and Frontotemporal Lobar Degeneration.

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    Taipa, Ricardo; Brochado, Paulo; Robinson, Andrew; Reis, Inês; Costa, Patrício; Mann, David M; Melo Pires, Manuel; Sousa, Nuno

    2017-01-01

    Microglia-driven neuroinflammation can play an important role in the pathophysiology of neurodegenerative disorders. In this study, we sought to characterize the distribution of microglial cell activation in 2 neurodegenerative dementias with distinct protein signatures, Alzheimer disease (AD) and frontotemporal lobar degeneration (FTLD) of the TDP subtype, and to determine if there was an anatomical correlation with the phenotypes most commonly associated with these conditions. The distribution and extent of microglial cell activation was assessed semiquantitatively in the hippocampal formation, cortical gray matter, and subcortical white matter of CD68-immunostained sections of the frontal, temporal, parietal, and occipital cortices from 15 pathologically confirmed cases of AD, 13 cases of FTLD, and 18 controls. Significantly higher levels of microglial cell activation occurred in the subiculum in AD and FTLD than in controls. Additionally, AD had higher microglial activation in the CA1 and FTLD in the hippocampal white matter than the controls. Microglial activation was greater in the dentate gyrus molecular layer in AD than in FTLD. In the cortical regions, the 2 pathological groups differed only in frontal white matter, with the FTLD group showing higher microglial scores. FTLD showed higher microglial activation in the white matter compared to the respective gray matter in the entorhinal, temporal, and frontal regions. Our work expands the knowledge of the distribution and magnitude of microglial activation in these disorders. Additionally, we found some microglial circuit-specific patterns that could help to explain some of the clinical overlap between AD and FTLD-TDP, namely in memory deficits. © 2017 S. Karger AG, Basel.

  19. Minocycline attenuates mechanical allodynia and central sensitization following peripheral second-degree burn injury.

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    Chang, Yu-Wen; Waxman, Stephen G

    2010-11-01

    Burn injury induces severe pain that can be refractory to existing pharmacotherapies. The underlying mechanism of burn pain remains unclear. We previously established an animal model and reported that unilateral burn injury induces chronic and bilateral mechanical allodynia, which is associated with central sensitization and microglial activation in the spinal cord dorsal horn. Modulation of the activity of microglia and p38 mitogen-activated protein kinase (MAPK) has been shown to ameliorate neuropathic pain in several nerve-injury pain models. In the present study, we show in this rat model that daily treatment with the microglial inhibitor minocycline (10 mg/kg), administered at the time of burn injury and for 7 days thereafter, significantly attenuates ipsilateral and contralateral allodynia as assessed up to 1 month following burn injury. These sensory changes are paralleled by significant suppression of evoked hyperexcitability of dorsal-horn neurons and of the expression of phosphorylated p38 (phospho-p38) in OX42+ microglial cells within the dorsal horn. Our results suggest that modulation of inflammation at early times after burn injury may have long-lasting effects, attenuating central neuropathic mechanisms which contribute to pain after burn injury. We demonstrate, in a rodent model of burn-associated pain, that the microglial inhibitor minocycline, delivered at the time of burn injury and for 1 week thereafter, has long-lasting effects, attenuating microglial activation and neuronal hyperresponsiveness in the dorsal horns, and ameliorating allodynia for at least 1 month. Copyright © 2010 American Pain Society. Published by Elsevier Inc. All rights reserved.

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

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    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

  1. Cannabidiol inhibits pathogenic T cells, decreases spinal microglial activation and ameliorates multiple sclerosis-like disease in C57BL/6 mice

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    Kozela, Ewa; Lev, Nirit; Kaushansky, Nathali; Eilam, Raya; Rimmerman, Neta; Levy, Rivka; Ben-Nun, Avraham; Juknat, Ana; Vogel, Zvi

    2011-01-01

    BACKGROUND AND PURPOSE Cannabis extracts and several cannabinoids have been shown to exert broad anti-inflammatory activities in experimental models of inflammatory CNS degenerative diseases. Clinical use of many cannabinoids is limited by their psychotropic effects. However, phytocannabinoids like cannabidiol (CBD), devoid of psychoactive activity, are, potentially, safe and effective alternatives for alleviating neuroinflammation and neurodegeneration. EXPERIMENTAL APPROACH We used experimental autoimmune encephalomyelitis (EAE) induced by myelin oligodendrocyte glycoprotein (MOG) in C57BL/6 mice, as a model of multiple sclerosis. Using immunocytochemistry and cell proliferation assays we evaluated the effects of CBD on microglial activation in MOG-immunized animals and on MOG-specific T-cell proliferation. KEY RESULTS Treatment with CBD during disease onset ameliorated the severity of the clinical signs of EAE. This effect of CBD was accompanied by diminished axonal damage and inflammation as well as microglial activation and T-cell recruitment in the spinal cord of MOG-injected mice. Moreover, CBD inhibited MOG-induced T-cell proliferation in vitro at both low and high concentrations of the myelin antigen. This effect was not mediated via the known cannabinoid CB1 and CB2 receptors. CONCLUSIONS AND IMPLICATIONS CBD, a non-psychoactive cannabinoid, ameliorates clinical signs of EAE in mice, immunized against MOG. Suppression of microglial activity and T-cell proliferation by CBD appeared to contribute to these beneficial effects. LINKED ARTICLES This article is part of a themed issue on Cannabinoids in Biology and Medicine. To view the other articles in this issue visit http://dx.doi.org/10.1111/bph.2011.163.issue-7 PMID:21449980

  2. ISSLS PRIZE IN BASIC SCIENCE 2018: Growth differentiation factor-6 attenuated pro-inflammatory molecular changes in the rabbit anular-puncture model and degenerated disc-induced pain generation in the rat xenograft radiculopathy model.

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    Miyazaki, Shingo; Diwan, Ashish D; Kato, Kenji; Cheng, Kevin; Bae, Won C; Sun, Yang; Yamada, Junichi; Muehleman, Carol; Lenz, Mary E; Inoue, Nozomu; Sah, Robert L; Kawakami, Mamoru; Masuda, Koichi

    2018-04-01

    To elucidate the effects of growth differentiation factor-6 (GDF6) on: (i) gene expression of inflammatory/pain-related molecules and structural integrity in the rabbit intervertebral disc (IVD) degeneration model, and (ii) sensory dysfunction and changes in pain-marker expression in dorsal nerve ganglia (DRGs) in the rat xenograft radiculopathy model. Forty-six adolescent rabbits received anular-puncture in two non-consecutive lumbar IVDs. Four weeks later, phosphate-buffered saline (PBS) or GDF6 (1, 10 or 100 µg) was injected into the nucleus pulposus (NP) of punctured discs and followed for 4 weeks for gene expression analysis and 12 weeks for structural analyses. For pain assessment, eight rabbits were sacrificed at 4 weeks post-injection and NP tissues of injected discs were transplanted onto L5 DRGs of 16 nude rats to examine mechanical allodynia. The rat DRGs were analyzed immunohistochemically. In GDF6-treated rabbit NPs, gene expressions of interleukin-6, tumor necrosis factor-α, vascular endothelial growth factor, prostaglandin-endoperoxide synthase 2, and nerve growth factor were significantly lower than those in the PBS group. GDF6 injections resulted in partial restoration of disc height and improvement of MRI disc degeneration grades with statistical significance in rabbit structural analyses. Allodynia induced by xenograft transplantation of rabbit degenerated NPs onto rat DRGs was significantly reduced by GDF6 injection. Staining intensities for ionized calcium-binding adaptor molecule-1 and calcitonin gene-related peptide in rat DRGs of the GDF6 group were significantly lower than those of the PBS group. GDF6 injection may change the pathological status of degenerative discs and attenuate degenerated IVD-induced pain.

  3. Rosiglitazone attenuates inflammation and CA3 neuronal loss following traumatic brain injury in rats

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    Liu, Hao; Rose, Marie E. [Geriatric Research Educational and Clinical Center, V.A. Pittsburgh Healthcare System, PA (United States); Department of Neurology, University of Pittsburgh School of Medicine, PA (United States); Culver, Sherman; Ma, Xiecheng; Dixon, C. Edward [Geriatric Research Educational and Clinical Center, V.A. Pittsburgh Healthcare System, PA (United States); Department of Neurosurgery, University of Pittsburgh, PA 15216 (United States); Department of Critical Care Medicine, University of Pittsburgh, PA 15216 (United States); Graham, Steven H., E-mail: Steven.Graham@va.gov [Geriatric Research Educational and Clinical Center, V.A. Pittsburgh Healthcare System, PA (United States); Department of Neurology, University of Pittsburgh School of Medicine, PA (United States)

    2016-04-15

    Rosiglitazone, a potent peroxisome proliferator-activated receptor (PPAR)-γ agonist, has been shown to confer neuroprotective effects in stroke and spinal cord injury, but its role in the traumatic brain injury (TBI) is still controversial. Using a controlled cortical impact model in rats, the current study was designed to determine the effects of rosiglitazone treatment (6 mg/kg at 5 min, 6 h and 24 h post injury) upon inflammation and histological outcome at 21 d after TBI. In addition, the effects of rosiglitazone upon inflammatory cytokine transcription, vestibulomotor behavior and spatial memory function were determined at earlier time points (24 h, 1–5 d, 14–20 d post injury, respectively). Compared with the vehicle-treated group, rosiglitazone treatment suppressed production of TNFα at 24 h after TBI, attenuated activation of microglia/macrophages and increased survival of CA3 neurons but had no effect on lesion volume at 21 d after TBI. Rosiglitazone-treated animals had improved performance on beam balance testing, but there was no difference in spatial memory function as determined by Morris water maze. In summary, this study indicates that rosiglitazone treatment in the first 24 h after TBI has limited anti-inflammatory and neuroprotective effects in rat traumatic injury. Further study using an alternative dosage paradigm and more sensitive behavioral testing may be warranted. - Highlights: • Effects of rosiglitazone after CCI were evaluated using a rat TBI model. • Rosiglitazone suppressed production of TNFα at 24 h after CCI. • Rosiglitazone inhibited microglial activation at 21 d after CCI. • Rosiglitazone increased survival of CA3 neurons at 21 d after CCI. • Rosiglitazone-treated animals had improved performance in beam balance testing.

  4. Rosiglitazone attenuates inflammation and CA3 neuronal loss following traumatic brain injury in rats

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    Liu, Hao; Rose, Marie E.; Culver, Sherman; Ma, Xiecheng; Dixon, C. Edward; Graham, Steven H.

    2016-01-01

    Rosiglitazone, a potent peroxisome proliferator-activated receptor (PPAR)-γ agonist, has been shown to confer neuroprotective effects in stroke and spinal cord injury, but its role in the traumatic brain injury (TBI) is still controversial. Using a controlled cortical impact model in rats, the current study was designed to determine the effects of rosiglitazone treatment (6 mg/kg at 5 min, 6 h and 24 h post injury) upon inflammation and histological outcome at 21 d after TBI. In addition, the effects of rosiglitazone upon inflammatory cytokine transcription, vestibulomotor behavior and spatial memory function were determined at earlier time points (24 h, 1–5 d, 14–20 d post injury, respectively). Compared with the vehicle-treated group, rosiglitazone treatment suppressed production of TNFα at 24 h after TBI, attenuated activation of microglia/macrophages and increased survival of CA3 neurons but had no effect on lesion volume at 21 d after TBI. Rosiglitazone-treated animals had improved performance on beam balance testing, but there was no difference in spatial memory function as determined by Morris water maze. In summary, this study indicates that rosiglitazone treatment in the first 24 h after TBI has limited anti-inflammatory and neuroprotective effects in rat traumatic injury. Further study using an alternative dosage paradigm and more sensitive behavioral testing may be warranted. - Highlights: • Effects of rosiglitazone after CCI were evaluated using a rat TBI model. • Rosiglitazone suppressed production of TNFα at 24 h after CCI. • Rosiglitazone inhibited microglial activation at 21 d after CCI. • Rosiglitazone increased survival of CA3 neurons at 21 d after CCI. • Rosiglitazone-treated animals had improved performance in beam balance testing.

  5. The microglial system in the eye and brain in response to stimuli in vivo.

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    Ellis-Behnke, Rutledge G; Jonas, Rahul A; Jonas, Jost B

    2013-01-01

    Microglial cells function as first responders to signal inflammation, react to injuries by creating a wall to block invaders, and clear debris from the site. To better understand the modulation of microglia in inflammation and injury of eye and brain, we developed a morphological and orienting classification system of each stage of microglia, calling it the 'Spider Effect'. 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. Our findings support a morphologically defined stepwise activation and deactivation of microglia cells. This relates to inflammation in the eye due to noxious stimuli, injury, or increase in pressure. Future studies may address the reported modulation of the microglial system in retina and optic nerve head in acute and chronic glaucoma.

  6. LED enhances anti-inflammatory effect of luteolin (3’,4’,5,7-tetrahydroxyflavone) in vitro

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    Fan, Shengnuo; Habib, Ahsan; Liu, Jun; Tan, Jun

    2018-01-01

    Neuroinflammation is a complex pathological process usually results from abnormal microglial activation, thus, intervention in a microglial stimulation pathway could be a promising approach for the treatment of neurodegenerative diseases. Luteolin is an important bioflavonoid possesses anti-inflammatory properties, which is widely studied over these years. Light emitting diode (LED) therapy is reported to be a potential therapeutic strategy for many diseases including neurodegenerative diseases. However, little is known about the anti-inflammatory effect of LED therapy on activated microglial cells, even less is known whether there is a synergistic anti-inflammatory effect exist in LED and luteolin therapy. In this study, we aimed to confirm the anti-inflammatory effect of luteolin and LED combination therapy in lipopolysaccharide (LPS)-stimulated BV2 microglial cells. We showed that luteolin inhibited LPS-induced cytotoxicity, tumor necrosis factor alpha (TNFα) and interleukin-6 (IL-6) production through modulation of p38 and extracellular signal-regulated kinase (ERK) signaling in BV2 cells. In addition, LED therapy enhanced the anti-inflammatory effect of luteolin. These results suggest that a synergistic effect between luteolin and LED could be a new effective therapy in relieving neuroinflammation. PMID:29423013

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

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    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.

  8. Tart cherry extracts reduce inflammatory and oxidative stress signaling in microglial cells

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    Tart cherries contain an array of polyphenols that can decrease inflammation and oxidative stress (OS), which contribute to cognitive declines seen in aging populations. Previous studies have shown that polyphenols from dark-colored fruits can reduce stress-mediated signaling in BV-2 mouse microglia...

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

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    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.

  10. Chronic Psychological Distress as an Inducer of Microglial Activation and Leukocyte Recruitment into the Area Postrema.

    Science.gov (United States)

    Vargas-Caraveo, Alejandra; Pérez-Ishiwara, David Guillermo; Martínez-Martínez, Alejandro

    2015-01-01

    Chronic psychological distress can cause neuroinflammation, but the involvement of leukocytes in this inflammatory response remains unclear. The area postrema (AP) is considered a neural-immune interface because it lacks a blood-brain barrier and a site for leukocyte recruitment in neuroinflammatory conditions induced by immunological insults, but its role in chronic psychological distress has not been explored. To determine leukocyte recruitment to the AP after chronic psychological distress. Rats were exposed to cat odor for 5 consecutive days to induce distress, and, on the 6th day, their brains were dissected to perform immunohistofluorescence studies of the AP. Immune cells were identified and quantified with CD45 and CD11b markers. The distribution of neurons and immune cells was determined using TrkA and CD45 markers, respectively. Distress induced a significant increase in CD45(+) and CD11b(+) cells in the AP. Three immunophenotypes were determined in the control and distress groups: CD45(+)/CD11b(-), CD45(+)/CD11b(+) and CD45(-)/CD11b(+). CD expression, morphology and fluorescence intensity enabled the identification of different immune cell types: starting from longitudinal ramified microglia (mainly in the control group) to amoeboid microglia, monocytes and lymphocytes (mostly in the distressed group). TrkA and CD45 expression in the AP revealed the proximity between soma neurons and leukocytes. Interestingly, some CD45(+) cells expressed TrkA, with increased expression in the distressed group. The identification of microglial activation, leukocyte recruitment and the close proximity between neurons and leukocytes in the AP after chronic psychological distress exposure suggests the AP as a site for distress-induced immune responses and engraftment of leukocytes infiltrating the CNS. © 2015 S. Karger AG, Basel.

  11. 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.

  12. Roles of TLR3 and RIG-I in Mediating the Inflammatory Response in Mouse Microglia following Japanese Encephalitis Virus Infection

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    Rong Jiang

    2014-01-01

    Full Text Available Japanese encephalitis virus (JEV infection can cause central nervous system disease with irreversible neurological damage in humans and animals. Evidence suggests that overactivation of microglia leads to greatly increased neuronal damage during JEV infection. However, the mechanism by which JEV induces the activation of microglia remains unclear. Toll-like receptor 3 (TLR3 and retinoic acid-inducible gene I (RIG-I can recognize double-stranded RNA, and their downstream signaling results in production of proinflammatory mediators. In this study, we investigated the roles of TLR3 and RIG-I in the inflammatory response caused by JEV infection in the mouse microglial cell line. JEV infection induced the expression of TLR3 and RIG-I and the activation of extracellular signal-regulated kinase (ERK and p38 mitogen-activated protein kinase (p38MAPK. Knockdown of TLR3 and RIG-I attenuated activation of ERK, p38MAPK, activator protein 1 (AP-1, and nuclear factor κB (NF-κB. Secretion of TNF-α, IL-6, and CCL-2, which was induced by JEV, was reduced by TLR3 and RIG-I knockdown and inhibitors of phosphorylated ERK and p38MAPK. Furthermore, viral proliferation was increased following knockdown of TLR3 and RIG-I. Our findings suggest that the signaling pathways of TLR3 and RIG-I play important roles in the JEV-induced inflammatory response of microglia.

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

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    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.

  14. Inflammatory aspects of Alzheimer disease and other neurodegenerative disorders.

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    Schwab, Claudia; McGeer, Patrick L

    2008-05-01

    Alzheimer and a number of other neurodegenerative diseases are characterized by the presence of reactive microglia and reactive astrocytes in association with the lesions. The classic view that microglia exist primarily in either a resting or activated state needs to be broadened in view of recent results. Resting microglia are in constant activity sampling their surround. Activated microglia may be pro-inflammatory, releasing inflammatory cytokines and other inflammatory mediators, or anti-inflammatory, promoting the healing process. There is evidence that microglial phagocytosis is more powerful in the anti-inflammatory state. Activated astrocytes also have pro-inflammatory and anti-inflammatory properties. In the pro-inflammatory state they release inflammatory cytokines. In the anti-inflammatory state they release various growth factors. In AD and other neurodegenerative diseases, both microglia and astrocytes are in a pro-inflammatory state. From a therapeutic point of view it is desirable to find methods of tipping the balance towards an anti-inflammatory state for both types of glia.

  15. 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.

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    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.

  16. 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

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    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.

  17. Microglial cell death induced by glycated bovine serum albumin: nitric oxide involvement.

    Science.gov (United States)

    Khazaei, Mohammad R; Habibi-Rezaei, Mehran; Karimzadeh, Fereshteh; Moosavi-Movahedi, Ali Akbar; Sarrafnejhad, Abdo Alfattah; Sabouni, Farzaneh; Bakhti, Mostafa

    2008-08-01

    Nonenzymatic glycation results in the formation of advanced glycation end products (AGEs) through a nonenzymatic multistep reaction of reducing sugars with proteins. AGEs have been suspected to be involved in the pathogenesis of several chronic clinical neurodegenerative complications including Alzheimer's disease, which is characterized with the activation of microglial cells in neuritic plaques. To find out the consequence of this activation on microglial cells, we treated the cultured microglial cells with different glycation levels of Bovine Serum Albumin (BSA) which were prepared in vitro. Extent of glycation of protein has been characterized during 16 weeks of incubation with glucose. Treatment of microglial cells with various levels of glycated albumin induced nitric oxide (NO) production and consequently cell death. We also tried to find out the mode of death in AGE-activated microglial cells. Altogether, our results suggest that AGE treatment causes microglia to undergo NO-mediated apoptotic and necrotic cell death in short term and long term, respectively. NO production is a consequence of iNOS expression in a JNK dependent RAGE signalling after activation of RAGE by AGE-BSA.

  18. 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...... 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...... are relatively resistant to telomerase deficiency during steady state conditions, despite an overall reduction in microglial numbers. Furthermore, telomerase deficiency and aging may provide disparate cues leading to distinct changes in microglial morphology and phenotype....

  19. TMEM16F Regulates Spinal Microglial Function in Neuropathic Pain States

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    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. Proinflammatory-Activated Glioma Cells Induce a Switch in Microglial Polarization and Activation Status, From a Predominant M2b Phenotype to a Mixture of M1 and M2a/B Polarized Cells

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    Lucia Lisi

    2014-04-01

    Full Text Available Malignant gliomas are primary brain tumors characterized by morphological and genetic complexities, as well as diffuse infiltration into normal brain parenchyma. Within gliomas, microglia/macrophages represent the largest tumor-infiltrating cell population, contributing by at least one-third to the total tumor mass. Bi-directional interactions between glioma cells and microglia may therefore play an important role on tumor growth and biology. In the present study, we have characterized the influence of glioma-soluble factors on microglial function, comparing the effects of media harvested under basal conditions with those of media obtained after inducing a pro-inflammatory activation state in glioma cells. We found that microglial cells undergo a different pattern of activation depending on the stimulus; in the presence of activated glioma-derived factors, i.e. a condition mimicking the late stage of pathology, microglia presents as a mixture of polarization phenotypes (M1 and M2a/b, with up-regulation of iNOS (inducible nitric oxide synthase, ARG (arginase and IL (interleukine-10. At variance, microglia exposed to basal glioma-derived factors, i.e. a condition resembling the early stage of pathology, shows a more specific pattern of activation, with increased M2b polarization status and up-regulation of IL-10 only. As far as viability and cell proliferation are concerned, both LI-CM [LPS (lipopolysaccharide—IFNγ (interferon γ conditioned media] and C-CM (control-conditioned media induce similar effects on microglial morphology. Finally, in human glioma tissue obtained from surgical resection of patients with IV grade glioblastoma, we detected a significant amount of CD68 positive cells, which is a marker of macrophage/microglial phagocytic activity, suggesting that in vitro findings presented here might have a relevance in the human pathology as well.

  1. Neurogenic exacerbation of microglial and astrocyte responses to Neisseria meningitidis and Borrelia burgdorferi.

    Science.gov (United States)

    Chauhan, Vinita S; Sterka, David G; Gray, David L; Bost, Kenneth L; Marriott, Ian

    2008-06-15

    Although glial cells are recognized for their roles in maintaining neuronal function, there is growing appreciation of the ability of resident CNS cells to initiate and/or augment inflammation following trauma or infection. The tachykinin, substance P (SP), is well known to augment inflammatory responses at peripheral sites and its presence throughout the CNS raises the possibility that this neuropeptide might serve a similar function within the brain. In support of this hypothesis, we have recently demonstrated the expression of high affinity receptors for SP (Neurokinin-1 (NK-1) receptors) on microglia and shown that this tachykinin can significantly elevate bacterially induced inflammatory prostanoid production by isolated cultures of these cells. In the present study, we demonstrate that endogenous SP/NK-1R interactions are an essential component in the initiation and/or progression of CNS inflammation in vivo following exposure to two clinically relevant bacterial CNS pathogens, Neisseria meningitidis and Borrelia burgdorferi. We show that in vivo elevations in inflammatory cytokine production and decreases in the production of an immunosuppressive cytokine are markedly attenuated in mice genetically deficient in the expression of the NK-1R or in mice treated with a specific NK-1R antagonist. Furthermore, we have used isolated cultures of microglia and astrocytes to demonstrate that SP can augment inflammatory cytokine production by these resident CNS cell types following exposure to either of these bacterial pathogens. Taken together, these studies indicate a potentially important role for neurogenic exacerbation of resident glial immune responses in CNS inflammatory diseases, such as bacterial meningitis.

  2. Mycobacterium tuberculosis-infected human monocytes down-regulate microglial MMP-2 secretion in CNS tuberculosis via TNFα, NFκB, p38 and caspase 8 dependent pathways

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    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.

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

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    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

  4. Evidence for increased microglial priming and macrophage recruitment in the dorsal anterior cingulate white matter of depressed suicides.

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    Torres-Platas, Susana G; Cruceanu, Cristiana; Chen, Gary Gang; Turecki, Gustavo; Mechawar, Naguib

    2014-11-01

    Despite increasing evidence supporting the neuroinflammatory theory of depression, little is known about cerebral macrophages in individuals suffering from major depression. In the present study, we investigated the morphology and distribution of cells immunostained for the macrophage-specific marker ionized calcium binding adaptor molecule 1 (IBA1) in the dorsal anterior cingulate cortex (dACC) white matter of middle-aged depressed suicides and matched non-psychiatric controls. This region is known for its implication in mood disorders, and its white matter compartment was previously found to display hypertrophic astrocytes in depressed suicides. Distributions of IBA1-immunoreactive (IBA-IR) microglial phenotypes were assessed using stereology and cell morphometry, and blood vessels were characterized as being intimately associated with either a high or a low density of IBA1-IR amoeboid-like cells. Total densities of IBA1-IR microglia did not differ between depressed suicides and controls. However, a finer analysis examining relative proportions of microglial phenotypes revealed that the ratio of primed over ramified ("resting") microglia was significantly increased in depressed suicides. Strikingly, the proportion of blood vessels surrounded by a high density of macrophages was more than twice higher in depressed suicides than in controls, and this difference was strongly significant. Consistent with these observations, gene expression of IBA1 and MCP-1, a chemokine involved in the recruitment of circulating monocytes, was significantly upregulated in depressed suicides. Furthermore, mRNA for CD45, a marker enriched in perivascular macrophages, was also significantly increased in samples from depressed suicides. An increase compared to controls was also observed in the proportion of blood vessels surrounded by a high density of CD45-IR cells, but this difference did not reach significance. These histological and molecular data suggest the recruitment of monocytes

  5. Sevoflurane preconditioning induced endogenous neurogenesis against ischemic brain injury by promoting microglial activation.

    Science.gov (United States)

    Li, Li; Saiyin, Hexige; Xie, Jingmo; Ma, Lixiang; Xue, Lei; Wang, Wei; Liang, Weimin; Yu, Qiong

    2017-04-25

    Brain ischemia causes irreversible damage to functional neurons in cases of infarct. Promoting endogenous neurogenesis to replace necrotic neurons is a promising therapeutic strategy for ischemia patients. The neuroprotective role of sevoflurane preconditioning implies that it might also enhance endogenous neurogenesis and functional restoration in the infarct region. By using a transient middle cerebral artery occlusion (tMCAO) model, we discovered that endogenous neurogenesis was enhanced by sevoflurane preconditioning. This enhancement process is characterized by the promotion of neuroblast proliferation within the subventricular zone (SVZ), migration and differentiation into neurons, and the presence of astrocytes and oligodendrocytes at the site of infarct. The newborn neurons in the sevoflurane preconditioning group showed miniature excitatory postsynaptic currents (mEPSCs), increased synaptophysin and PSD95 staining density, indicating normal neuronal function. Furthermore, long-term behavioral improvement was observed in the sevoflurane preconditioning group consistent with endogenous neurogenesis. Further histological analyses showed that sevoflurane preconditioning accelerated microglial activation, including migration, phagocytosis and secretion of brain-derived neurotrophic factor (BDNF). Intraperitoneal injection of minocycline, a microglial inhibitor, suppressed microglial activation and reversed neurogenesis. Our data showed that sevoflurane preconditioning promoted microglial activities, created a favorable microenvironment for endogenous neurogenesis and accelerated functional reconstruction in the infarct region.

  6. 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

    with a chronic proinflammatory reaction in the brain, aging causes a significant reduction in the capacity of microglia to scan their environment. This type of pathology is markedly accelerated in mouse models of AD, resulting in a severe microglial process deficiency, and possibly contributing to enhanced...... cognitive decline....

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

    Science.gov (United States)

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

    2012-01-17

    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 that were double-knockout for Crry and either C3 or factor B did not show priming, demonstrating dependence on alternative pathway activation. Colocalization of C3b/iC3b and CR3 implicated the CR3/iC3b interaction in priming. Systemic lipopolysaccharide challenge overactivated primed microglia with florid expression of proinflammatory molecules, which were blocked by complement inhibition. Relevance for neurodegenerative disease is exemplified by human multiple sclerosis (MS) and by experimental autoimmune encephalomyelitis (EAE), a model of MS. In human MS, microglial priming was evident in perilesional white matter, in close proximity to C3b/iC3b deposits. EAE was accelerated and exacerbated in Crry-deficient mice, and was dependent on C activation. In summary, C3-dependent microglial priming confers susceptibility to other challenges. Our observations are relevant to progression in MS and other neurological diseases exacerbated by acute insults.

  8. Microglial morphology and dynamic behavior is regulated by ionotropic glutamatergic and GABAergic neurotransmission.

    Directory of Open Access Journals (Sweden)

    Aurora M Fontainhas

    Full Text Available PURPOSE: Microglia represent the primary resident immune cells in the CNS, and have been implicated in the pathology of neurodegenerative diseases. Under basal or "resting" conditions, microglia possess ramified morphologies and exhibit dynamic surveying movements in their processes. Despite the prominence of this phenomenon, the function and regulation of microglial morphology and dynamic behavior are incompletely understood. We investigate here whether and how neurotransmission regulates "resting" microglial morphology and behavior. METHODS: We employed an ex vivo mouse retinal explant system in which endogenous neurotransmission and dynamic microglial behavior are present. We utilized live-cell time-lapse confocal imaging to study the morphology and behavior of GFP-labeled retinal microglia in response to neurotransmitter agonists and antagonists. Patch clamp electrophysiology and immunohistochemical localization of glutamate receptors were also used to investigate direct-versus-indirect effects of neurotransmission by microglia. RESULTS: Retinal microglial morphology and dynamic behavior were not cell-autonomously regulated but are instead modulated by endogenous neurotransmission. Morphological parameters and process motility were differentially regulated by different modes of neurotransmission and were increased by ionotropic glutamatergic neurotransmission and decreased by ionotropic GABAergic neurotransmission. These neurotransmitter influences on retinal microglia were however unlikely to be directly mediated; local applications of neurotransmitters were unable to elicit electrical responses on microglia patch-clamp recordings and ionotropic glutamatergic receptors were not located on microglial cell bodies or processes by immunofluorescent labeling. Instead, these influences were mediated indirectly via extracellular ATP, released in response to glutamatergic neurotransmission through probenecid-sensitive pannexin hemichannels

  9. Distribution of microglial cells in the cerebral hemispheres of embryonic and neonatal chicks

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    Ignácio A.R.

    2005-01-01

    Full Text Available The distribution, morphology and morphometry of microglial cells in the chick cerebral hemispheres from embryonic day 4 (E4 to the first neonatal day (P1 were studied by histochemical labeling with a tomato (Lycopersicon esculentum lectin. The histochemical analysis revealed lectin-reactive cells in the nervous parenchyma on day E4. Between E4 (5.7 ± 1.35 mm length and E17 (8.25 ± 1.2 mm length, the lectin-reactive cells were identified as ameboid microglia and observed starting from the subventricular layer, distributed throughout the mantle layer and in the proximity of the blood vessels. After day E13, the lectin-reactive cells exhibited elongated forms with small branched processes, and were considered primitive ramified microglia. Later, between E18 (5.85 ± 1.5 mm cell body length and P1 (3.25 ± 0.6 mm cell body length, cells with more elongated branched processes were observed, constituting the ramified microglia. Our findings provide additional information on the migration and differentiation of microglial cells, whose ramified form is observed at the end of embryonic development. The present paper focused on the arrangement of microglial cells in developing cerebral hemispheres of embryonic and neonatal chicks, which are little studied in the literature. Details of morphology, morphometry and spatial distribution of microglial cells contributed to the understanding of bird and mammal central nervous system ontogeny. Furthermore, the identification and localization of microglial cells during the normal development could be used as a morphological guide for embryonic brain injury researches.

  10. Luteolin inhibits microglial inflammation and improves neuron survival against inflammation.

    Science.gov (United States)

    Zhu, Li-Hong; Bi, Wei; Qi, Ren-bin; Wang, Hua-dong; Lu, Da-xiang

    2011-06-01

    Microglia activation is one of the causative factors for neuroinflammation, which results in brain damage during neurodegenerative disease. Accumulating evidence has shown that the flavonoid luteolin (Lut) possesses potent anti-inflammatory properties; however, its effect on microglia inhibition is currently unknown. Moreover, it is not clear whether Lut also has indirect neuroprotective effects by reducing inflammatory mediators and suppressing microglia activation. In this study, we examined the effects of Lut on lipopolysaccharide (LPS)-induced proinflammatory mediator production and signaling pathways in murine BV2 microglia. In addition, we cocultured microglia and neurons to observe the indirect neuroprotective effects of Lut. Lut inhibited the LPS-stimulated expression of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor alpha (TNF-α), and interleukin-1β (IL-1β) as well as the production of nitric oxide (NO) and prostaglandin E(2) (PGE(2)). Moreover, Lut blocked LPS-induced nuclear factor kappa B (NF-κB) activation. Preincubation of microglia with Lut diminished the neurotoxic effects, owing to the direct anti-inflammatory effects of the compound. Taken together, our findings suggest that Lut may have a potential therapeutic application in the treatment of neuroinflammatory disorders. Copyright © 2011 Informa Healthcare USA, Inc.

  11. Piper sarmentosum Roxb. confers neuroprotection on beta-amyloid (Aβ)-induced microglia-mediated neuroinflammation and attenuates tau hyperphosphorylation in SH-SY5Y cells.

    Science.gov (United States)

    Yeo, Emilia Tze Ying; Wong, Kelly Wang Ling; See, Mun Ling; Wong, Ka Yan; Gan, Sook Yee; Chan, Elaine Wan Ling

    2018-05-10

    Piper sarmentosum Roxb. (PS), belonging to Piperaceae family, is an edible plant with medicinal properties. It is traditionally used by the Malays to treat headache and boost memory. Pharmacological studies revealed that PS exhibits anti-inflammatory, anti-oxidant, anti-acetylcholinesterase, and anti-depressant-like effects. In view of this, the present study aimed to investigate the anti-inflammatory actions of PS and its potential neuroprotective effects against beta-amyloid (Aβ)-induced microglia-mediated neurotoxicity. The inhibitory effects of hexane (L HXN ), dichloromethane (L DCM ), ethyl acetate (L EA ) and methanol (L MEOH ) extracts from leaves of PS on Aβ-induced production and mRNA expression of pro-inflammatory mediators in BV-2 microglial cells were assessed using colorimetric assay with Griess reagent, ELISA kit and real-time RT-PCR respectively. Subsequently, MTT reduction assay was used to evaluate the neuroprotective effects of PS leaf extracts against Aβ-induced microglia-mediated neurotoxicity in SH-SY5Y neuroblastoma cells. The levels of tau proteins phosphorylated at threonine 231 (pT231) and total tau proteins (T-tau) were determined using ELISA kits. Polar extracts of PS leaves (L EA and L MEOH ) reduced the Aβ-induced secretion of pro-inflammatory cytokines (IL-1β and TNF-α) in BV-2 cells by downregulating the mRNA expressions of pro-inflammatory cytokines. The inhibition of nitric oxide (NO) production could be due to the free radical scavenging activity of the extracts. In addition, conditioned media from Aβ-induced BV-2 cells pre-treated with L EA and L MEOH protected SH-SY5Y cells against microglia-mediated neurotoxicity. Further mechanistic study suggested that the neuroprotective effects were associated with the downregulation of phosphorylated tau proteins. The present study suggests that polar extracts of PS leaves confer neuroprotection against Aβ-induced microglia-mediated neurotoxicity in SH-SY5Y cells by attenuating tau

  12. Differential expression of miR-184 in temporal lobe epilepsy patients with and without hippocampal sclerosis – Influence on microglial function

    Science.gov (United States)

    Danis, Bénédicte; van Rikxoort, Marijke; Kretschmann, Anita; Zhang, Jiong; Godard, Patrice; Andonovic, Lidija; Siegel, Franziska; Niehusmann, Pitt; Hanon, Etienne; Delev, Daniel; von Lehe, Marec; Kaminski, Rafal M.; Pfeifer, Alexander; Foerch, Patrik

    2016-01-01

    Epilepsy is one of the most common neurological disorders characterized by recurrent seizures due to neuronal hyperexcitability. Here we compared miRNA expression patterns in mesial temporal lobe epilepsy with and without hippocampal sclerosis (mTLE + HS and mTLE −HS) to investigate the regulatory mechanisms differentiating both patient groups. Whole genome miRNA sequencing in surgically resected hippocampi did not reveal obvious differences in expression profiles between the two groups of patients. However, one microRNA (miR-184) was significantly dysregulated, which was confirmed by qPCR. We observed that overexpression of miR-184 inhibited cytokine release after LPS stimulation in primary microglial cells, while it did not affect the viability of murine primary neurons and primary astrocytes. Pathway analysis revealed that miR-184 is potentially involved in the regulation of inflammatory signal transduction and apoptosis. Dysregulation of some the potential miR-184 target genes was confirmed by qPCR and 3′UTR luciferase reporter assay. The reduced expression of miR-184 observed in patients with mTLE + HS together with its anti-inflammatory effects indicate that miR-184 might be involved in the modulation of inflammatory processes associated with hippocampal sclerosis which warrants further studies elucidating the role of miR-184 in the pathophysiology of mTLE. PMID:27666871

  13. Deletion of macrophage-inflammatory protein 1 alpha retards neurodegeneration in Sandhoff disease mice.

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    Wu, Yun-Ping; Proia, Richard L

    2004-06-01

    Sandhoff disease is a prototypical lysosomal storage disorder in which a heritable deficiency of a lysosomal enzyme, beta-hexosaminidase, results in the storage of the enzyme's substrates in lysosomes. As with many of the other lysosomal storage diseases, neurodegeneration is a prominent feature. Although the cellular and molecular pathways that underlie the neurodegenerative process are not yet fully understood, macrophage/microglial-mediated inflammation has been suggested as one possible mechanism. We now show that the expanded macrophage/microglial population in the CNS of Sandhoff disease mice is compounded by the infiltration of cells from the periphery. Coincident with the cellular infiltration was an increased expression of macrophage-inflammatory protein 1alpha (MIP-1alpha), a leukocyte chemokine, in astrocytes. Deletion of MIP-1alpha expression resulted in a substantial decrease in infiltration and macrophage/microglial-associated pathology together with neuronal apoptosis in Sandhoff disease mice. These mice without MIP-1alpha showed improved neurologic status and a longer lifespan. The results indicate that the pathogenesis of Sandhoff disease involves an increase in MIP-1alpha that induces monocytes to infiltrate the CNS, expand the activated macrophage/microglial population, and trigger apoptosis of neurons, resulting in a rapid neurodegenerative course.

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

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    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

  15. 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...... and IL-1, and to phagocytose and clear amyloid beta (As), however, the influence of TNF and IL-1, and inflammation in general, on these processes is still poorly understood. We have studied the development of As pathology, and basal and lipopolysaccharide (LPS) stimulated microglial cytokine production...... mice. Microglial expression of TNF and IL-1s can be significantly increased by i.p. injection of LPS, which we find reduces cortical As pathology at 12 months. Results will also be reported on the influence of IL-1 in modulating As pathology during early disease stages in APPswe/PS1DE9 mice. Together...

  16. Developmental alcohol exposure impairs synaptic plasticity without overtly altering microglial function in mouse visual cortex.

    Science.gov (United States)

    Wong, Elissa L; Lutz, Nina M; Hogan, Victoria A; Lamantia, Cassandra E; McMurray, Helene R; Myers, Jason R; Ashton, John M; Majewska, Ania K

    2018-01-01

    Fetal alcohol spectrum disorder (FASD), caused by gestational ethanol (EtOH) exposure, is one of the most common causes of non-heritable and life-long mental disability worldwide, with no standard treatment or therapy available. While EtOH exposure can alter the function of both neurons and glia, it is still unclear how EtOH influences brain development to cause deficits in sensory and cognitive processing later in life. Microglia play an important role in shaping synaptic function and plasticity during neural circuit development and have been shown to mount an acute immunological response to EtOH exposure in certain brain regions. Therefore, we hypothesized that microglial roles in the healthy brain could be permanently altered by early EtOH exposure leading to deficits in experience-dependent plasticity. We used a mouse model of human third trimester high binge EtOH exposure, administering EtOH twice daily by subcutaneous injections from postnatal day 4 through postnatal day 9 (P4-:P9). Using a monocular deprivation model to assess ocular dominance plasticity, we found an EtOH-induced deficit in this type of visually driven experience-dependent plasticity. However, using a combination of immunohistochemistry, confocal microscopy, and in vivo two-photon microscopy to assay microglial morphology and dynamics, as well as fluorescence activated cell sorting (FACS) and RNA-seq to examine the microglial transcriptome, we found no evidence of microglial dysfunction in early adolescence. We also found no evidence of microglial activation in visual cortex acutely after early ethanol exposure, possibly because we also did not observe EtOH-induced neuronal cell death in this brain region. We conclude that early EtOH exposure caused a deficit in experience-dependent synaptic plasticity in the visual cortex that was independent of changes in microglial phenotype or function. This demonstrates that neural plasticity can remain impaired by developmental ethanol exposure even in

  17. Anti-inflammatory mechanisms of sepsis.

    Science.gov (United States)

    Shubin, Nicholas J; Monaghan, Sean F; Ayala, Alfred

    2011-01-01

    Over the past two decades, it has become well accepted that sepsis exhibits two, oftentimes concomitant, inflammatory stages; a pro-inflammatory phase, referred to as the systemic inflammatory response syndrome (SIRS), and an anti-inflammatory phase, called the compensatory anti-inflammatory response syndrome (CARS). Considering that therapeutic interventions designed to attenuate the pro-inflammatory septic response have generally failed, much recent research has gone into understanding how and why septic patients display immunosuppressive characteristics, what the significance of septic immunosuppression may be and if there exists any therapeutic targets within the CARS. Herein, we describe the potential mechanisms of the immunosuppressive/CARS phase of sepsis by discussing what anti-inflammatory agents, receptors and cell populations are currently believed to contribute to CARS. Copyright © 2011 S. Karger AG, Basel.

  18. Astrocyte-Derived CCL2 is Associated with M1 Activation and Recruitment of Cultured Microglial Cells

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    Mingfeng He

    2016-02-01

    Full Text Available Background/Aims: Microglia are an essential player in central nervous system inflammation. Recent studies have demonstrated that the astrocytic chemokine, CCL2, is associated with microglial activation in vivo. However, CCL2-induced microglial activation has not yet been studied in vitro. The purpose of the current study was to understand the role of astrocyte-derived CCL2 in microglial activation and to elucidate the underlying mechanism(s. Methods: Primary astrocytes were pre-treated with CCL2 siRNA and stimulated with TNF-α. The culture medium (CM was collected and added to cultures of microglia, which were incubated with and without CCR2 inhibitor. Microglial cells were analyzed by quantitative RT-PCR to determine whether they polarized to the M1 or M2 state. Microglial migratory ability was assessed by transwell migration assay. Results: TNF-α stimulated the release of CCL2 from astrocytes, even if the culture media containing TNF-α was replaced with fresh media after 3 h. CM from TNF-α-stimulated astrocytes successfully induced microglial activation, which was ascertained by increased activation of M1 and enhanced migration ability. In contrast, CM from astrocytes pretreated with CCL2 siRNA showed no effect on microglial activation, compared to controls. Additionally, microglia pre-treated with RS102895, a CCR2 inhibitor, were resistant to activation by CM from TNF-α-stimulated astrocytes. Conclusion: This study demonstrates that the CCL2/CCR2 pathway of astrocyte-induced microglial activation is associated with M1 polarization and enhanced migration ability, indicating that this pathway could be a useful target to ameliorate inflammation in the central nervous system.

  19. Regulation of microglia activity by glaucocalyxin-A: attenuation of lipopolysaccharide-stimulated neuroinflammation through NF-κB and p38 MAPK signaling pathways.

    Science.gov (United States)

    Kim, Byung-Wook; Koppula, Sushruta; Hong, Seong-Su; Jeon, Sae-Bom; Kwon, Ji-Hye; Hwang, Bang-Yeon; Park, Eun-Jung; Choi, Dong-Kug

    2013-01-01

    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.

  20. 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.

  1. Anti-inflammatory effects of α-galactosylceramide analogs in activated microglia: involvement of the p38 MAPK signaling pathway.

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    Yeon-Hui Jeong

    Full Text Available Microglial activation plays a pivotal role in the development and progression of neurodegenerative diseases. Thus, anti-inflammatory agents that control microglial activation can serve as potential therapeutic agents for neurodegenerative diseases. Here, we designed and synthesized α-galactosylceramide (α-GalCer analogs to exert anti-inflammatory effects in activated microglia. We performed biological evaluations of 25 α-GalCer analogs and observed an interesting preliminary structure-activity relationship in their inhibitory influence on NO release and TNF-α production in LPS-stimulated BV2 microglial cells. After identification of 4d and 4e as hit compounds, we further investigated the underlying mechanism of their anti-inflammatory effects using RT-PCR analysis. We confirmed that 4d and 4e regulate the expression of iNOS, COX-2, IL-1β, and IL-6 at the mRNA level and the expression of TNF-α at the post-transcriptional level. In addition, both 4d and 4e inhibited LPS-induced DNA binding activities of NF-κB and AP-1 and phosphorylation of p38 MAPK without affecting other MAP kinases. When we examined the anti-inflammatory effect of a p38 MAPK-specific inhibitor, SB203580, on microglial activation, we observed an identical inhibitory pattern as that of 4d and 4e, not only on NO and TNF-α production but also on the DNA binding activities of NF-κB and AP-1. Taken together, these results suggest that p38 MAPK plays an important role in the anti-inflammatory effects of 4d and 4e via the modulation of NF-κB and AP-1 activities.

  2. Anti-inflammatory effects of the cannabidiol derivative dimethylheptyl-cannabidiol - studies in BV-2 microglia and encephalitogenic T cells.

    Science.gov (United States)

    Juknat, Ana; Kozela, Ewa; Kaushansky, Nathali; Mechoulam, Raphael; Vogel, Zvi

    2016-05-01

    Dimethylheptyl-cannabidiol (DMH-CBD), a non-psychoactive, synthetic derivative of the phytocannabinoid cannabidiol (CBD), has been reported to be anti-inflammatory in RAW macrophages. Here, we evaluated the effects of DMH-CBD at the transcriptional level in BV-2 microglial cells as well as on the proliferation of encephalitogenic T cells. BV-2 cells were pretreated with DMH-CBD, followed by stimulation with the endotoxin lipopolysaccharide (LPS). The expression levels of selected genes involved in stress regulation and inflammation were determined by quantitative real-time PCR. In addition, MOG35-55-reactive T cells (TMOG) were cultured with antigen-presenting cells in the presence of DMH-CBD and MOG35-55 peptide, and cell proliferation was determined by measuring [3H]thymidine incorporation. DMH-CBD treatment downregulated in a dose-dependent manner the mRNA expression of LPS-upregulated pro-inflammatory genes (Il1b, Il6, and Tnf) in BV-2 microglial cells. The expression of these genes was also downregulated by DMH-CBD in unstimulated cells. In parallel, DMH-CBD upregulated the expression of genes related to oxidative stress and glutathione homeostasis such as Trb3, Slc7a11/xCT, Hmox1, Atf4, Chop, and p8 in both stimulated and unstimulated microglial cells. In addition, DMH-CBD dose-dependently inhibited MOG35-55-induced TMOG proliferation. The results show that DMH-CBD has similar anti-inflammatory properties to those of CBD. DMH-CBD downregulates the expression of inflammatory cytokines and protects the microglial cells by inducing an adaptive cellular response against inflammatory stimuli and oxidative injury. In addition, DMH-CBD decreases the proliferation of pathogenic activated TMOG cells.

  3. Microglial number is related to the number of tyrosine hydroxylase neurons in SHR and normotensive rats.

    Science.gov (United States)

    Kapoor, Komal; Bhandare, Amol M; Mohammed, Suja; Farnham, Melissa M J; Pilowsky, Paul M

    2016-07-01

    Microglia are ubiquitously distributed throughout the central nervous system (CNS) and play a critical role in the maintenance of neuronal homeostasis. Recent advances have shown that microglia, never resting cells of the CNS, continuously monitor and influence neuronal/synaptic activity levels, by communicating with neurons with the aid of their dynamic processes. The brainstem contains many catecholaminergic nuclei that are key to many aspects of brain function. This includes C1 neurons of the ventrolateral medulla that are thought to play a critical role in control of the circulation. Despite the role of catecholaminergic brainstem neurons in normal physiology, the presence of microglia that surrounds them is poorly understood. Here, we investigate the spatial distribution and morphology of microglia in catecholaminergic nuclei of the brainstem in 3 strains of rat: Sprague-Dawley (SD), Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR). Our data reveal that microglia are heterogeneously distributed within and across different strains of rats. Interestingly, intra-strain comparison of tyrosine hydroxylase-immunoreactive (TH-ir) neuronal and microglial number reveals that microglial number varies with the TH-ir neuronal number in the brainstem. Even though microglial spatial distribution varies across brainstem nuclei, microglial morphology (% area covered, number of end point processes and branch length) does not differ significantly. This work provides the first evidence that even though microglia, in their surveilling state, do not vary appreciably in their morphology across brainstem areas, they do have a heterogeneous pattern of distribution that may be influenced by their local environment. Copyright © 2016. Published by Elsevier B.V.

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

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    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.

  5. Methamphetamine alters microglial immune function through P2X7R signaling

    OpenAIRE

    Fernandes, Nicole C.; Sriram, Uma; Gofman, Larisa; Cenna, Jonathan M.; Ramirez, Servio H.; Potula, Raghava

    2016-01-01

    Background Purinoceptors have emerged as mediators of chronic inflammation and neurodegenerative processes. The ionotropic purinoceptor P2X7 (P2X7R) is known to modulate proinflammatory signaling and integrate neuronal-glial circuits. Evidence of P2X7R involvement in neurodegeneration, chronic pain, and chronic inflammation suggests that purinergic signaling plays a major role in microglial activation during neuroinflammation. In this study, we investigated the effects of methamphetamine (MET...

  6. Anti-inflammatory effects of aromatic-turmerone through blocking of NF-κB, JNK, and p38 MAPK signaling pathways in amyloid β-stimulated microglia.

    Science.gov (United States)

    Park, Sun Young; Jin, Mei Ling; Kim, Young Hun; Kim, YoungHee; Lee, Sang Joon

    2012-09-01

    Amyloid β (Aβ) induces the production of neuroinflammatory molecules, which may contribute to the pathogenesis of numerous neurodegenerative diseases. Therefore, suppression of neuroinflammatory molecules could be developed as a therapeutic method. Aromatic (ar)-turmerone, turmeric oil isolated from Curcuma longa, has long been used in Southeast Asia as both a remedy and a food. In this study, we investigated the anti-inflammatory effects of ar-turmerone in BV2 microglial cells. Aβ-stimulated microglial cells were tested for the expression and activation of MMP-9, iNOS, and COX-2, the production of proinflammatory cytokines, chemokines, and ROS, as well as the underlying signaling pathways. Ar-turmerone significantly suppressed Aβ-induced expression and activation of MMP-9, iNOS, and COX-2, but not MMP-2. Ar-turmerone also reduced TNF-α, IL-1β, IL-6, and MCP-1 production in Aβ-stimulated microglial cells. Further, ar-turmerone markedly inhibited the production of ROS. Impaired translocation and activation of NF-κB were observed in Aβ-stimulated microglial cells exposed to ar-turmerone. Furthermore, ar-turmerone inhibited the phosphorylation and degradation of IκB-α as well as the phosphorylation of JNK and p38 MAPK. These results suggest that ar-turmerone impaired the Aβ-induced inflammatory response of microglial cells by inhibiting the NF-κB, JNK, and p38 MAPK signaling pathways. Lastly, ar-turmerone protected hippocampal HT-22 cells from indirect neuronal toxicity induced by activated microglial cells. These novel findings provide new insights into the development of ar-turmerone as a therapeutic agent for the treatment of neurodegenerative disorders. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. Polyamidoamine dendrimer-conjugated triamcinolone acetonide attenuates nerve injury-induced spinal cord microglia activation and mechanical allodynia.

    Science.gov (United States)

    Kim, Hwisung; Choi, Boomin; Lim, Hyoungsub; Min, Hyunjung; Oh, Jae Hoon; Choi, Sunghyun; Cho, Joung Goo; Park, Jong-Sang; Lee, Sung Joong

    2017-01-01

    Background Accumulating evidence on the causal role of spinal cord microglia activation in the development of neuropathic pain after peripheral nerve injury suggests that microglial activation inhibitors might be useful analgesics for neuropathic pain. Studies also have shown that polyamidoamine dendrimer may function as a drug delivery vehicle to microglia in the central nervous system. In this regard, we developed polyamidoamine dendrimer-conjugated triamcinolone acetonide, a previously identified microglial activation inhibitor, and tested its analgesic efficacy in a mouse peripheral nerve injury model. Result Polyamidoamine dendrimer was delivered selectively to spinal cord microglia upon intrathecal administration. Dendrimer-conjugated triamcinolone acetonide inhibited lipoteichoic acid-induced proinflammatory gene expression in primary glial cells. In addition, dendrimer-conjugated triamcinolone acetonide administration (intrathecal) inhibited peripheral nerve injury-induced spinal cord microglial activation and the expression of pain-related genes in the spinal cord, including Nox2, IL-1β, TNF-α, and IL-6. Dendrimer-conjugated triamcinolone acetonide administration right after nerve injury almost completely reversed peripheral nerve injury-induced mechanical allodynia for up to three days. Meanwhile, dendrimer-conjugated triamcinolone acetonide administration 1.5 days post injury significantly attenuated mechanical allodynia. Conclusion Our data demonstrate that dendrimer-conjugated triamcinolone acetonide inhibits spinal cord microglia activation and attenuates neuropathic pain after peripheral nerve injury, which has therapeutic implications for the treatment of neuropathic pain.

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

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    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.

  9. Peripheral nerve injury induces a transitory microglial reaction in the rat infralimbic cortex.

    Science.gov (United States)

    Chu Sin Chung, Paul; Panigada, Tania; Cardis, Romain; Decosterd, Isabelle; Gosselin, Romain-Daniel

    2017-08-10

    Undeniable evidence shows that microglia in the spinal cord undergo marked reactions following peripheral injuries. However, only rare studies have investigated the possible short and long term microglial reaction in brain regions following peripheral nerve injury and its interspecies specificities. In the present study we examined microglia in subdivisions of the prefrontal cortex in mice and rats, 7days and 42days after spared nerve injury (SNI) of the sciatic nerve. We show that a bilateral increase of microglial density takes place in the infralimbic cortex in rats 7days post-injury (sham vs. SNI, n=5: ipsilateral 35.4% increase of the median, p=0.0317; contralateral 24.9% increase of the median, p=0.0079), without any detectable change in the other investigated regions, namely the anterior cingulate, prelimbic and agranular insular cortices. In mice, no observable difference could be found in any region at both time points, neither using Iba-1 immunostaining nor with CX3CR1-eGFP animals. Our results indicate that a transitory, species-specific and highly regionalized microglial reaction takes place in the prefrontal cortex following peripheral nerve injury. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Imaging microglial activation and amyloid burden in amnestic mild cognitive impairment.

    Science.gov (United States)

    Knezevic, Dunja; Verhoeff, Nicolaas Paul Lg; Hafizi, Sina; Strafella, Antonio P; Graff-Guerrero, Ariel; Rajji, Tarek; Pollock, Bruce G; Houle, Sylvain; Rusjan, Pablo M; Mizrahi, Romina

    2017-01-01

    Amnestic mild cognitive impairment (aMCI) is defined as a transitional state between normal aging and Alzheimer's disease (AD). Given the replicated finding of increased microglial activation in AD, we sought to investigate whether microglial activation is also elevated in aMCI and whether it is related to amyloid beta (Aβ) burden in-vivo . Eleven aMCI participants and 14 healthy volunteers completed positron emission tomography (PET) scans with [ 18 F]-FEPPA and [ 11 C]-PIB. Given the known sensitivity in affinity of second-generation TSPO radioligands, participants were genotyped for the TSPO polymorphism and only high-affinity binders were included. Dynamic [ 18 F]-FEPPA PET images were analyzed using the 2-tissue compartment model with arterial plasma input function. Additionally, a supplementary method, the standardized uptake value ratio (SUVR), was explored. [ 11 C]-PIB PET images were analyzed using the Logan graphical method. aMCI participants had significantly higher [ 11 C]-PIB binding in the cortical regions. No significant differences in [ 18 F]-FEPPA binding were observed between aMCI participants and healthy volunteers. In the aMCI group, [ 18 F]-FEPPA and [ 11 C]-PIB bindings were correlated in the hippocampus. There were no correlations between our PET measures and cognition. Our findings demonstrate that while Aβ burden is evident in the aMCI stage, microglial activation may not be present.

  11. Experience-Dependent Synaptic Plasticity in V1 Occurs without Microglial CX3CR1.

    Science.gov (United States)

    Schecter, Rachel W; Maher, Erin E; Welsh, Christina A; Stevens, Beth; Erisir, Alev; Bear, Mark F

    2017-11-01

    Brief monocular deprivation (MD) shifts ocular dominance and reduces the density of thalamic synapses in layer 4 of the mouse primary visual cortex (V1). We found that microglial lysosome content is also increased as a result of MD. Previous studies have shown that the microglial fractalkine receptor CX3CR1 is involved in synaptic development and hippocampal plasticity. We therefore tested the hypothesis that neuron-to-microglial communication via CX3CR1 is an essential component of visual cortical development and plasticity in male mice. Our data show that CX3CR1 is not required for normal development of V1 responses to visual stimulation, multiple forms of experience-dependent plasticity, or the synapse loss that accompanies MD in layer 4. By ruling out an essential role for fractalkine signaling, our study narrows the search for understanding how microglia respond to active synapse modification in the visual cortex. SIGNIFICANCE STATEMENT Microglia in the visual cortex respond to monocular deprivation with increased lysosome content, but signaling through the fractalkine receptor CX3CR1 is not an essential component in the mechanisms of visual cortical development or experience-dependent synaptic plasticity. Copyright © 2017 the authors 0270-6474/17/3710541-13$15.00/0.

  12. Dietary eicosapentaenoic acid normalizes hippocampal omega-3 and 6 polyunsaturated fatty acid profile, attenuates glial activation and regulates BDNF function in a rodent model of neuroinflammation induced by central interleukin-1β administration.

    Science.gov (United States)

    Dong, Yilong; Xu, Min; Kalueff, Allan V; Song, Cai

    2017-05-18

    Interleukin (IL)-1β can activate glial cells to trigger neuroinflammation and neurodegeneration. Lower omega (n)-3 polyunsaturated fatty acids (PUFAs) and lower n-3/n-6 PUFA ratios occur in the brain of patients with Alzheimer's disease (AD). We have previously reported that an n-3 PUFA, eicosapentaenoic acid (EPA), can improve memory and attenuate neurodegeneration-like changes in animal models of AD. However, whether and how EPA modulates glial cell activity and functions remains unclear. The aim of this study was to test the hypothesis that EPA may attenuate neuroinflammation by inhibiting microglial activation and microglia-produced proinflammatory cytokines, and by enhancing the expression of astrocytes-produced neurotrophins and their receptors. Male Long-Evans rats were fed either palm oil supplemented diet or EPA supplemented diet for 42 days. On day 36 of diet feeding, rats received an intracerebroventricular injection of IL-1β or saline for 7 days. The glial activation, the expression of amyloid precursor protein (APP), calcium-dependent phospholipase (cPL) A2, brain-derived neurotrophic factor (BDNF) and its receptor, and PUFA profile in the hippocampus were analyzed. IL-1β elevated biomarkers of microglial CD11b and astrocyte GFAP expression, increased the expression of APP, tumor-necrosis factor (TNF)-α, but reduced BDNF and its receptor (TrKB). IL-1β also lowered n-3 EPA and docosapentaenoic acid concentrations but increased n-6 PUFAs and cPLA2 activity in the hippocampus. EPA supplement normalized the n-3 and n-6 PUFA profiles and cPLA2 levels, inhibited glial activation, reduced APP and TNF-α expression, as well as up-regulated BDNF and TrKB. Supplementation with EPA appear to have potential effects on improving glial over-activation, n3/n6 imbalance and BDNF down-regulation, which contribute to anti-inflammatory and may provide beneficial effects on inflammation-associated disease such as AD.

  13. 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.

  14. 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.

  15. 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.

    Science.gov (United States)

    Suter, Marc R; Berta, Temugin; Gao, Yong-Jing; Decosterd, Isabelle; Ji, Ru-Rong

    2009-09-22

    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 Adelta-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. 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. (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.

  16. Neuroprotective effect of licochalcone A against oxygen-glucose deprivation/reperfusion in rat primary cortical neurons by attenuating oxidative stress injury and inflammatory response via the SIRT1/Nrf2 pathway.

    Science.gov (United States)

    Liu, Xiaohong; Ma, Ying; Wei, Xiaodi; Fan, Ting

    2018-04-01

    Perinatal hypoxic-ischemic encephalopathy (HIE) is a leading cause of neonatal death and neurological disability. Oxidative stress and neuroinflammation are typical pathogenic factors of HIE. Licochalcone A (LCA) exerts various biological properties, including anti-inflammatory and antioxidant activities. However, no data have been reported to elucidate the role of LCA in the development of HIE. In the present study, primary cultured rat cortical neurons were exposed to oxygen-glucose deprivation/reoxygenation (OGD/R) in vitro to simulate the in vivo situation of neonatal HIE. Interestingly, LCA significantly antagonized cell injury under OGD/R by increasing cell survival, inhibiting lactate dehydrogenase (LDH) release and cell apoptosis. Furthermore, treatment with LCA suppressed oxidative stress by decreasing reactive oxygen species (ROS) production and malondialdehyde (MDA) content, and increasing superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities in primary rat cortical neurons after OGD/R. LCA stimulation also restrained OGD/R-triggered increase in pro-inflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) production. Importantly, LCA treatment effectively counteracts OGD/R-mediated downregulation of silent information regulator 1 (SIRT1), nuclear factor erythroid2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1), and upregulation of nuclear factor kappa B p65 (NF-κB p65). Moreover, administration with SIRT1 inhibitor EX527 partly abolished LCA-induced neuroprotective effects on rat cortical neurons exposed to OGD/R. In conclusion, our study indicates that LCA exerts a neuroprotective effect against OGD/R-induced neuronal injury in rat primary cortical neurons, suggesting that LCA might act as a candidate therapeutic target drug used for HIE and related diseases. © 2017 Wiley Periodicals, Inc.

  17. Pressure surge attenuator

    Science.gov (United States)

    Christie, Alan M.; Snyder, Kurt I.

    1985-01-01

    A pressure surge attenuation system for pipes having a fluted region opposite crushable metal foam. As adapted for nuclear reactor vessels and heads, crushable metal foam is disposed to attenuate pressure surges.

  18. Cleome rutidosperma and Euphorbia thymifolia Suppress Inflammatory Response via Upregulation of Phase II Enzymes and Modulation of NF-κB and JNK Activation in LPS-Stimulated BV2 Microglia

    Directory of Open Access Journals (Sweden)

    Hsiou-Yu Ding

    2016-08-01

    Full Text Available Cleome rutidosperma DC. and Euphorbia thymifolia L. are herbal medicines used in traditional Indian and Chinese medicine to treat various illnesses. Reports document that they have antioxidant and anti-inflammatory activities; nonetheless, the molecular mechanisms involved in their anti-inflammatory actions have not yet been elucidated. The anti-neuroinflammatory activities and underlying mechanisms of ethanol extracts of Cleome rutidosperma (CR and Euphorbia thymifolia (ET were studied using lipopolysaccharide (LPS-stimulated microglial cell line BV2. The morphology changes and production of pro-inflammatory mediators were assayed. Gene expression of inflammatory genes such as inducible nitric oxide synthase (iNOS, cyclooxygenase (COX-2, interleukin (IL-1β, and CC chemokine ligand (CCL-2, as well as phase II enzymes such as heme oxygenase (HO-1, the modifier subunit of glutamate cysteine ligase (GCLM and NAD(PH quinone dehydrogenase 1 (NQO1, were further investigated using reverse transcription quantitative-PCR (RT-Q-PCR and Western blotting. The effects of CR and ET on mitogen activated protein kinases (MAPKs and nuclear factor (NF-κB signaling pathways were examined using Western blotting and specific inhibitors. CR and ET suppressed BV2 activation, down-regulated iNOS and COX-2 expression and inhibited nitric oxide (NO overproduction without affecting cell viability. They reduced LPS-mediated tumor necrosis factor (TNF and IL-6 production, attenuated IL-1β and CCL2 expression, but upregulated HO-1, GCLM and NQO1 expression. They also inhibited p65 NF-κB phosphorylation and modulated Jun-N terminal kinase (JNK activation in BV2 cells. SP600125, the JNK inhibitor, significantly augmented the anti-IL-6 activity of ET. NF-κB inhibitor, Bay 11-7082, enhanced the anti-IL-6 effects of both CR and ET. Znpp, a competitive inhibitor of HO-1, attenuated the anti-NO effects of CR and ET. Our results show that CR and ET exhibit anti

  19. 3-Hydroxy-4,7-megastigmadien-9-one, isolated from Ulva pertusa, attenuates TLR9-mediated inflammatory response by down-regulating mitogen-activated protein kinase and NF-κB pathways.

    Science.gov (United States)

    Ali, Irshad; Manzoor, Zahid; Koo, Jung-Eun; Kim, Jung-Eun; Byeon, Sang-Hee; Yoo, Eun-Sook; Kang, Hee-Kyoung; Hyun, Jin-Won; Lee, Nam-Ho; Koh, Young-Sang

    2017-12-01

    Seaweeds are rich in bioactive compounds in the form of vitamins, phycobilins, polyphenols, carotenoids, phycocyanins and polysaccharides; many of these are known to have advantageous applications in human health. 3-Hydroxy-4,7-megastigmadien-9-one (comp) was isolated from Ulva pertusa (U. pertusa) Kjellman (Ulvaceae), which is a familiar edible green seaweed. This study evaluates the anti-inflammatory activity of comp in CpG DNA-stimulated bone marrow-derived dendritic cells (BMDCs). For evaluating the effect of comp on cytokines production, BMDCs were treated with doses of comp (0, 0.5, 1, 2, 5, 10, 25 and 50 μM) for 1 h before stimulation with CpG DNA (1 μM). Cytokine production was measured by ELISA. Western blotting was conducted for evaluating effect of comp (50 μM) on MAPKs and NF-κB pathways. Luciferase reporter gene assay was conducted for effect of comp (0, 5, 10 and 25 μM) on transcriptional activity of AP-1 and NF-κB. Comp exhibited strong inhibition of interleukin (IL)-12 p40, IL-6 and TNF-α cytokine production with IC 50 values of 6.02 ± 0.35, 27.14 ± 0.73, and 7.56 ± 0.21 μM, respectively. It blocked MAPKs and NF-κB pathways by inhibiting the phosphorylation of ERK1/2, JNK1/2, p38 and IκBα. In addition, it strongly inhibited the transcriptional activity of AP-1 and NF-κB with IC 50 values of 8.74 ± 0.31 and 12.08 ± 0.24 μM, respectively. Taken together, these data suggest that comp has a significant anti-inflammatory property and warrants further studies concerning the potential of comp for medicinal use.

  20. 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.

  1. Modulating the inflammatory properties of activated microglia with Docosahexaenoic acid and Aspirin

    Science.gov (United States)

    2013-01-01

    Background Microglia are considered the “resident macrophages” of the brain. When in their resting state, microglia perform routine maintenance and immune surveillance. Once activated, either by injury or an immune stimulus, microglia secrete a variety of pro-inflammatory molecules, such as Nitric Oxide, superoxide, and inflammatory cytokines. Up-regulation of pro-inflammatory molecules is transient, and does not cause neurodegeneration. However, if up-regulation lasts for an extended period of time, neurodegeneration ensues. Many neurodegenerative diseases are characterized by chronic inflammation due to microglial activation. Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) have been proposed as possible preventative treatments for neurodegenerative diseases, due to their anti-inflammatory properties. Docosahexaenoic Acid (DHA) is an omega-3 polyunsaturated fatty acid (PUFA) that has potent anti-inflammatory properties.This research work sought to elucidate whether microglial activation can be modulated by combining Aspirin, a classical NSAID, with Docosahexaenoic Acid, a natural anti-inflammatory agent. The combined ability of Aspirin and DHA to modulate microglial activation was determined in the context of pro-inflammatory cytokines, Nitric Oxide levels, as well as total Glutathione levels. Results Docosahexaenoic Acid increased total Glutathione levels in microglia cells and enhanced their anti-oxidative capacity. It reduced production of the pro-inflammatory cytokines TNF-α and IL-6 induced through TLR-3 and TLR-4 activation. Furthermore, it reduced production of Nitric Oxide. Aspirin showed similar anti-inflammatory effects with respect to TNF-α during TLR-3 and TLR-7 stimulation. Aspirin did not show any redection in terms of Nitric Oxide production. Combination of Aspirin and Docosahexaenoic Acid showed augmentation in total Glutathione production during TLR-7 stimulation as well as a reduction in IL-6, TNF-α and Nitric Oxide. Conclusions

  2. 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.

  3. 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.

  4. Minocycline, a microglial inhibitor, blocks spinal CCL2-induced heat hyperalgesia and augmentation of glutamatergic transmission in substantia gelatinosa neurons.

    Science.gov (United States)

    Huang, Chung-Yu; Chen, Ying-Ling; Li, Allen H; Lu, Juu-Chin; Wang, Hung-Li

    2014-01-10

    Several lines of evidence suggest that CCL2 could initiate the hyperalgesia of neuropathic pain by causing central sensitization of spinal dorsal horn neurons and facilitating nociceptive transmission in the spinal dorsal horn. The cellular and molecular mechanisms by which CCL2 enhances spinal pain transmission and causes hyperalgesia remain unknown. The substantia gelatinosa (lamina II) of the spinal dorsal horn plays a critical role in nociceptive transmission. An activated spinal microglia, which is believed to release pro-inflammatory cytokines including TNF-α, plays an important role in the development of neuropathic pain, and CCL2 is a key mediator for spinal microglia activation. In the present study, we tested the hypothesis that spinal CCL2 causes the central sensitization of substantia gelatinosa neurons and enhances spinal nociceptive transmission by activating the spinal microglia and augmenting glutamatergic transmission in lamina II neurons. CCL2 was intrathecally administered to 2-month-old male rats. An intrathecal injection of CCL2 induced heat hyperalgesia, which was assessed using the hot plate test. Whole-cell voltage-clamp recordings substantia gelatinosa neurons in spinal cord slices were performed to record glutamatergic excitatory postsynaptic currents (EPSCs) and GABAergic inhibitory postsynaptic currents (IPSCs). The hot plate test showed that 1 day after the intrathecal injection of CCL2 (1 μg), the latency of hind-paw withdrawal caused by a heat stimulus was significantly reduced in rats. One day after the intrathecal administration of CCL2, the amplitude of the evoked glutamatergic EPSCs and the frequency of spontaneous glutamatergic miniature EPSCs (mEPSCs) were significantly increased in outer lamina II neurons. Intrathecal co-injection of minocycline, a specific inhibitor of microglial activation, and CCL2 blocked the CCL2-induced reduction in the latency of hind-paw withdrawal and thermal hyperalgesia. Following intrathecal co

  5. Bifunctional role of ephrin A1-Eph system in stimulating cell proliferation and protecting cells from cell death through the attenuation of ER stress and inflammatory responses in bovine mammary epithelial cells.

    Science.gov (United States)

    Kang, Minkyung; Jeong, Wooyoung; Bae, Hyocheol; Lim, Whasun; Bazer, Fuller W; Song, Gwonhwa

    2018-03-01

    Structural and functional development of the mammary gland is constant in the mammary gland life cycle. Eph receptors and their ligands, ephrins, control events through cell-to-cell interactions during embryonic development, and adult tissue homeostasis; however, little information on participation of ephrin A1, a representative ligand of the Eph receptor, in the development and function of normal mammary glands is known. In this study, we demonstrated functional effects of the ephrin A1-Eph system and mechanisms of its action on bovine mammary epithelial (MAC-T) cells. The in vitro cultured MAC-T cells expressed the ephrin A1 ligand and EphA1, A2, A4, A7, and A8 among the eight members of the Eph A family. Our results revealed that ephrin A1 induced MAC-T cell cycle progression and stimulated cell proliferation with abundant expression of nucleic PCNA and cyclin D1 proteins. Additionally, ephrin A1 induced activation of intracellular signaling molecules involved in PI3 K/AKT and MAPK signaling, and the proliferation-stimulating effect of ephrin A1 was mediated by activation of these pathways. Furthermore, ephrin A1 influenced expression and activation of various ER stress-related proteins and protected MAC-T cells from stress-induced cell death. Finally, ephrin A1 alleviated LPS-induced cell death through down-regulation of inflammatory cytokines. In conclusion, the results of this study suggest that the Eph A-ephrin A1 system is a positive factor in the increase and maintenance of epithelial cells in mammary glands of cows; the signaling system contributes to development, remodeling, and functionality of normal mammary glands and could overcome mastitis in cows and other mammals. © 2017 Wiley Periodicals, Inc.

  6. 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.

  7. Pelvic Inflammatory Disease (PID)

    Science.gov (United States)

    ... FAQs Pelvic Inflammatory Disease (PID) Page Navigation ▼ ACOG Pregnancy Book Pelvic Inflammatory Disease (PID) Patient Education FAQs Pelvic Inflammatory Disease (PID) Patient Education Pamphlets - ...

  8. 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.

  9. A dibenzoylmethane derivative inhibits lipopolysaccharide-induced NO production in mouse microglial cell line BV-2.

    Science.gov (United States)

    Takano, Katsura; Ishida, Natsumi; Kawabe, Kenji; Moriyama, Mitsuaki; Hibino, Satoshi; Choshi, Tominari; Hori, Osamu; Nakamura, Yoichi

    2017-04-05

    Microglial activation has been suggested to play important roles in various neurodegenerative diseases by phagocytosis and producing various factors such as nitric oxide (NO), proinflammatory cytokines. Excessive production of NO, as a consequence of increased inducible nitric oxide synthase (iNOS) in microglia, contributes to the neurodegeneration. During a search for compounds that regulate endoplasmic reticulum (ER) stress, a dibenzoylmethane derivative, 2,2'-dimethoxydibenzoylmethane (DBM 14-26) was identified as a novel neuroprotective agent (Takano et al., Am. J. Physiol. Cell Physiol. 293, C1884-1894, 2007). We previously reported in cultured astrocytes that DBM 14-26 protected hydrogen peroxide-induced cell death and inhibited lipopolysaccharide (LPS)-induced NO production (Takano et al., J. Neurosci. Res. 89, 955-965, 2011). In the present study, we assessed the effects of DBM 14-26 on microglia using the mouse cell line BV-2 and found that DBM 14-26 inhibited LPS-induced iNOS expression and NO production also in microglia. DBM 14-26 also suppressed LPS-induced IL-1β expression. Conditioned medium of BV-2 cells stimulated by LPS significantly decreased cell viability of neuron (human neuroblastoma SH-SY5Y cells) compared with the absence of LPS. Conditioned medium of BV-2 cells stimulated by LPS in the presence of DBM 14-26 did not significantly decreased cell viability of neuron. These results indicate that microglial activation by LPS causes neuronal cell death and DBM 14-26 protect neuron through the inhibition of microglial activation. Functional regulation of microglia by DBM 14-26 could be a therapeutic candidate for the treatment of neurodegenerative diseases. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. 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

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

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    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.

  12. Purinergic receptor P2RY12-dependent microglial closure of the injured blood-brain barrier

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    Lou, Nanhong; Takano, Takahiro; Pei, Yong

    2016-01-01

    Microglia are integral functional elements of the central nervous system, but the contribution of these cells to the structural integrity of the neurovascular unit has not hitherto been assessed. We show here that following blood-brain barrier (BBB) breakdown, P2RY12 (purinergic receptor P2Y, G......-protein coupled, 12)-mediated chemotaxis of microglia processes is required for the rapid closure of the BBB. Mice treated with the P2RY12 inhibitor clopidogrel, as well as those in which P2RY12 was genetically ablated, exhibited significantly diminished movement of juxtavascular microglial processes and failed...

  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. 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

    -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......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...

  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 nervous...... system. We investigated T-cell infiltration, myelin clearance, microglial activation, and phagocytic activity distal to sites of axonal transection through analysis of the perforant pathway deafferented dentate gyrus in SJL mice that had received T cells specific for myelin basic protein (TMBP...

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

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    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

  17. Methamphetamine alters microglial immune function through P2X7R signaling.

    Science.gov (United States)

    Fernandes, Nicole C; Sriram, Uma; Gofman, Larisa; Cenna, Jonathan M; Ramirez, Servio H; Potula, Raghava

    2016-04-26

    Purinoceptors have emerged as mediators of chronic inflammation and neurodegenerative processes. The ionotropic purinoceptor P2X7 (P2X7R) is known to modulate proinflammatory signaling and integrate neuronal-glial circuits. Evidence of P2X7R involvement in neurodegeneration, chronic pain, and chronic inflammation suggests that purinergic signaling plays a major role in microglial activation during neuroinflammation. In this study, we investigated the effects of methamphetamine (METH) on microglial P2X7R. ESdMs were used to evaluate changes in METH-induced P2X7R gene expression via Taqman PCR and protein expression via western blot analysis. Migration and phagocytosis assays were used to evaluate functional changes in ESdMs in response to METH treatment. METH-induced proinflammatory cytokine production following siRNA silencing of P2X7R in ESdMs measured P2X7R-dependent functional changes. In vivo expression of P2X7R and tyrosine hydroxylase (TH) was visualized in an escalating METH dose mouse model via immunohistochemical analysis. Stimulation of ESdMs with METH for 48 h significantly increased P2X7R mRNA (*p P2X7R protein in cellular fractionations revealed increases in membrane P2X7R (*p P2X7R-dependent through the use of A 438079, a P2X7R-competitive antagonist, which reversed the METH effects (****p P2X7R antagonist reduced METH-induced phagocytosis (****p P2X7R decreased TNF-α (*p P2X7R and decreased TH expression in the striata of escalating dose METH animal model compared to controls. This study sheds new light on the functional role of P2X7R in the regulation of microglial effector functions during substance abuse. Our findings suggest that P2X7R plays an important role in METH-induced microglial activation responses. P2X7R antagonists may thus constitute a novel target of therapeutic utility in neuroinflammatory conditions by regulating pathologically activated glial cells in stimulant abuse.

  18. Microglial phagocytosis/apoptosis uncoupling in epilepsy: mechanisms and detrimental consequences

    OpenAIRE

    Abiega Etxabe, Oihane

    2017-01-01

    174 p. La microglía es la célula inmune y el fagocito profesional del cerebro. La microglía es la encargada de fagocitar las células que mueren en el cerebro por apoptosis, o muerte programada. La fagocitosis de estas células es un proceso clave para mantener la salud del tejido nervioso. En condiciones fisiológicas, la fagocitosis microglial es un proceso muy rápido y eficaz. No obstante, el proceso fagocítico, sus mecanismos de regulación y sus consecuencias para el tejido siguen siendo ...

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

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    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.

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

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    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.

  1. Subneurotoxic copper(II)-induced NF-κB-dependent microglial activation is associated with mitochondrial ROS

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Zhuqin; Yu, Fengxiang; Gong, Ping; Qiu, Yu; Zhou, Wei; Cui, Yongyao; Li, Juan, E-mail: lijuanpharm@gmail.com; Chen, Hongzhuan, E-mail: yaoli@shsmu.edu.cn

    2014-04-15

    Microglia-mediated neuroinflammation and the associated neuronal damage play critical roles in the pathogenesis of neurodegenerative disorders. Evidence shows an elevated concentration of extracellular copper(II) in the brains of these disorders, which may contribute to neuronal death through direct neurotoxicity. Here we explored whether extracellular copper(II) triggers microglial activation. Primary rat microglia and murine microglial cell line BV-2 cells were cultured and treated with copper(II). The content of tumor necrosis factor-α (TNF-α) and nitric oxide in the medium was determined. Extracellular hydrogen peroxide was quantified by a fluorometric assay with Amplex Red. Mitochondrial superoxide was measured by MitoSOX oxidation. At subneurotoxic concentrations, copper(II) treatment induced a dose- and time-dependent release of TNF-α and nitric oxide from microglial cells, and caused an indirect, microglia-mediated neurotoxicity that was blocked by inhibition of TNF-α and nitric oxide production. Copper(II)-initiated microglial activation was accompanied with reduced IkB-α expression as well as phosphorylation and translocation of nuclear factor-κB (NF-κB) p65 and was blocked by NF-κB inhibitors (BAY11-7082 and SC-514). Moreover, copper(II) treatment evoked a rapid release of hydrogen peroxide from microglial cells, an effect that was not affected by NADPH oxidase inhibitors. N-acetyl-cysteine, a scavenger of reactive oxygen species (ROS), abrogated copper(II)-elicited microglial release of TNF-α and nitric oxide and subsequent neurotoxicity. Importantly, mitochondrial production of superoxide, paralleled to extracellular release of hydrogen peroxide, was induced after copper(II) stimulation. Our findings suggest that extracellular copper(II) at subneurotoxic concentrations could trigger NF-κB-dependent microglial activation and subsequent neurotoxicity. NADPH oxidase-independent, mitochondria-derived ROS may be involved in this activation

  2. L-alanyl-glutamine pretreatment attenuates acute inflammatory response in children submitted to palatoplasty Pré-tratamento com L-alanil-glutamina atenua a resposta inflamatória aguda em crianças submetidas à palatoplastia

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    José Ferreira da Cunha Filho

    2011-01-01

    Full Text Available PURPOSE: To evaluate the effects of L-alanyl-glutamine (L-Ala-Gln pretreatment on oxidative stress, glycemic control and inflammatory response in children submitted to palatoplasty. METHODS: Thirty male children scheduled for routine palatoplasty, age range 2-10 years, were randomly assigned to 2 groups (n=15: Group A (saline, control and Group B (L-Ala-Gln. Group A received normal saline 100 ml, delivered intravenously by infusion pump over 3 hours preceding surgical procedure. Group B was treated with L-Ala-Gln, 20% solution (0.5g/Kg, adding saline to complete 100ml. Peripheral venous blood samples were collected at 5 different time-points: T1- at the beginning of the study, 3 h prior to the surgical procedure; T2- at the end of the infusion (before the surgical procedure, T3- at the end of the surgical procedure, T4- 6 h postoperative and T5- 12 h postoperative. Parameters analyzed included glutathione (GSH, thiobarbituric acid reactive substances (TBARS, glucose, insulin, C-reactive protein (CRP and interleukin-6 (IL-6. RESULTS: No statistically significant differences were found between groups comparing glucose, insulin, TBARS, GSH and IL-6 levels. However, glucose levels increased (P OBJETIVO: Avaliar os efeitos do pré-tratamento com L-alanil-glutamina (L-Ala-Gln sobre o estresse oxidativo, o controle glicêmico e a resposta inflamatória em crianças submetidas à palatoplastia. MÉTODOS: Trinta crianças do sexo masculino, agendadas para palatoplastia, faixa etária 2-10 anos, foram distribuídas aleatoriamente em dois grupos (n = 15: Grupo A (salina, controle e Grupo B (L-Ala-Gln. O grupo A recebeu solução salina 0,9% 100 ml, administrado por via intravenosa utilizando uma bomba de infusão durante 3 horas anteriores ao procedimento cirúrgico. O grupo B foi tratado com L-Ala-Gln, solução a 20% (0,5 g/kg, acrescentando soro fisiológico até completar 100 ml. Amostras de sangue venoso periférico foram coletadas em cinco momentos

  3. Improvements in hippocampal-dependent memory and microglial infiltration with calorie restriction and gastric bypass surgery, but not with vertical sleeve gastrectomy.

    Science.gov (United States)

    Grayson, B E; Fitzgerald, M F; Hakala-Finch, A P; Ferris, V M; Begg, D P; Tong, J; Woods, S C; Seeley, R J; Davidson, T L; Benoit, S C

    2014-03-01

    Much recent evidence suggest that obesity and related comorbidities contribute to cognitive decline, including the development of non age-related dementia and Alzheimer's disease. Obesity is a serious threat to public health, and few treatments offer proven long-term weight loss. In fact, bariatric surgery remains the most effective long-term therapy to reduce weight and alleviate other aspects of the metabolic syndrome (MetS). Unlike the demonstrated benefits of caloric restriction to prevent weight gain, few if any studies have compared various means of weight loss on central nervous system function and hippocampal-dependent cognitive processes. Our studies comprise the first direct comparisons of caloric restriction to two bariatric surgeries (Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG)) on cognitive function. Weight loss following caloric restriction, RYGB and VSG was associated with generalized improvements in metabolic health and hippocampal-dependent learning, as measured in the radial arm maze and spontaneous alternation tests. However, VSG-treated rats exhibited deficits on spatial learning tasks in the Morris water maze. In addition, whereas VSG animals had elevated hippocampal inflammation, comparable to that of obese controls, RYGB and calorie-restricted (pair-fed, PF) controls exhibited an amelioration of inflammation, as measured by the microglial protein ionized calcium binding adaptor molecule 1 (IBA1). We also assessed whether GHR (ghrelin) replacement would attenuate hippocampal inflammation in VSG, as post-surgical GHR levels are significantly reduced in VSG relative to RYGB and PF rats. However, GHR treatment did not attenuate the hippocampal inflammation. Although VSG was comparably effective at reducing body weight and improving glucose regulation as RYGB, VSG did not appear to confer an equal benefit on cognitive function and markers of inflammation.

  4. The redox state of the alarmin HMGB1 is a pivotal factor in neuroinflammatory and microglial priming: A role for the NLRP3 inflammasome.

    Science.gov (United States)

    Frank, Matthew G; Weber, Michael D; Fonken, Laura K; Hershman, Sarah A; Watkins, Linda R; Maier, Steven F

    2016-07-01

    The alarmin high mobility group box-1 (HMGB1) has been implicated as a key factor mediating neuroinflammatory processes. Recent findings suggest that the redox state of HMGB1 is a critical molecular feature of HMGB1 such that the reduced form (fr-HMGB1) is chemotactic, while the disulfide form (ds-HMGB1) is pro-inflammatory. The present study examined the neuroinflammatory effects of these molecular forms as well as the ability of these forms to prime the neuroinflammatory and microglial response to an immune challenge. To examine the neuroinflammatory effects of these molecular forms in vivo, animals were administered intra-cisterna magna (ICM) a single dose of fr-HMGB1 (10μg), ds-HMGB1 (10μg) or vehicle and basal pro-inflammatory effects were measured 2 and 24h post-injection in hippocampus. Results of this initial experiment demonstrated that ds-HMGB1 increased hippocampal pro-inflammatory mediators at 2h (NF-κBIα mRNA, NLRP3 mRNA and IL-1β protein) and 24h (NF-κBIα mRNA, TNFα mRNA, and NLRP3 protein) after injection. fr-HMGB1 had no effect on these mediators. These neuroinflammatory effects of ds-HMGB1 suggested that ds-HMGB1 may function to prime the neuroinflammatory response to a subsequent immune challenge. To assess the neuroinflammatory priming effects of these molecular forms, animals were administered ICM a single dose of fr-HMGB1 (10μg), ds-HMGB1 (10μg) or vehicle and 24h after injection, animals were challenged with LPS (10μg/kg IP) or vehicle. Neuroinflammatory mediators and the sickness response (3, 8 and 24h after injection) were measured 2h after immune challenge. We found that ds-HMGB1 potentiated the neuroinflammatory (NF-κBIα mRNA, TNFα mRNA, IL-1β mRNA, IL-6 mRNA, NLRP3 mRNA and IL-1β protein) and sickness response (reduced social exploration) to LPS challenge. fr-HMGB1 failed to potentiate the neuroinflammatory response to LPS. To examine whether these molecular forms of HMGB1 directly induce neuroinflammatory effects in

  5. Prenylated Flavonoids from Cudrania tricuspidata Suppress Lipopolysaccharide-Induced Neuroinflammatory Activities in BV2 Microglial Cells

    Science.gov (United States)

    Kim, Dong-Cheol; Yoon, Chi-Su; Quang, Tran Hong; Ko, Wonmin; Kim, Jong-Su; Oh, Hyuncheol; Kim, Youn-Chul

    2016-01-01

    In Korea and China, Cudrania tricuspidata Bureau (Moraceae) is an important traditional medicinal plant used to treat lumbago, hemoptysis, and contusions. The C. tricuspidata methanol extract suppressed both production of NO and PGE2 in BV2 microglial cells. Cudraflavanone D (1), isolated from this extract, remarkably suppressed the protein expression of inducible NO synthase and cyclooxygenase-2, and decreased the levels of NO and PGE2 in BV2 microglial cells exposed to lipopolysaccharide. Cudraflavanone D (1) also decreased IL-6, TNF-α, IL-12, and IL-1β production, blocked nuclear translocation of NF-κB heterodimers (p50 and p65) by interrupting the degradation and phosphorylation of inhibitor of IκB-α, and inhibited NF-κB binding. In addition, cudraflavanone D (1) suppressed the phosphorylation of c-Jun N-terminal kinase (JNK) and p38 MAPK pathways. This study indicated that cudraflavanone D (1) can be a potential drug candidate for the cure of neuroinflammation. PMID:26907256

  6. 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.

  7. 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.

  8. In vivo characterization of microglial engulfment of dying neurons in the zebrafish spinal cord

    Science.gov (United States)

    Morsch, Marco; Radford, Rowan; Lee, Albert; Don, Emily K.; Badrock, Andrew P.; Hall, Thomas E.; Cole, Nicholas J.; Chung, Roger

    2015-01-01

    Microglia are specialized phagocytes in the vertebrate central nervous system (CNS). As the resident immune cells of the CNS they play an important role in the removal of dying neurons during both development and in several neuronal pathologies. Microglia have been shown to prevent the diffusion of damaging degradation products of dying neurons by engulfment and ingestion. Here we describe a live imaging approach that uses UV laser ablation to selectively stress and kill spinal neurons and visualize the clearance of neuronal remnants by microglia in the zebrafish spinal cord. In vivo imaging confirmed the motile nature of microglia within the uninjured spinal cord. However, selective neuronal ablation triggered rapid activation of microglia, leading to phagocytic uptake of neuronal debris by microglia within 20–30 min. This process of microglial engulfment is highly dynamic, involving the extension of processes toward the lesion site and consequently the ingestion of the dying neuron. 3D rendering analysis of time-lapse recordings revealed the formation of phagosome-like structures in the activated microglia located at the site of neuronal ablation. This real-time representation of microglial phagocytosis in the living zebrafish spinal cord provides novel opportunities to study the mechanisms of microglia-mediated neuronal clearance. PMID:26379496

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

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    MAEZAWA, IZUMI; CALAFIORE, MARCO; WULFF, HEIKE; JIN, LEE-WAY

    2016-01-01

    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. PMID:22717189

  10. Expression of Tau40 induces activation of cultured rat microglial cells.

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    Lu Wang

    Full Text Available Accumulation of microtubule-associated protein tau has been observed in the brain of aging and tauopathies. Tau was observed in microglia, but its role is not illustrated. By immunofluorescence staining and the fractal dimension value assay in the present study, we observed that microglia were activated in the brains of rats and mice during aging, simultaneously, the immunoreactivities of total tau and the phosphorylated tau were significantly enhanced in the activated microglia. Furtherly by transient transfection of tau40 (human 2N/4R tau into the cultured rat microglia, we demonstrated that expression of tau40 increased the level of Iba1, indicating activation of microglia. Moreover, expression of tau40 significantly enhanced the membranous localization of the phosphorylated tau at Ser396 in microglia possibly by a mechanism involving protein phosphatase 2A, extracellular signal-regulated kinase and glycogen synthase kinase-3β. It was also found that expression of tau40 promoted microglial migration and phagocytosis, but not proliferation. And we observed increased secretion of several cytokines, including interleukin (IL-1β, IL-6, IL-10, tumor necrosis factor-α and nitric oxide after the expression of tau40. These data suggest a novel role of human 2N/4R tau in microglial activation.

  11. Inhibitory effects of antihistamines, diphenhydramine and chlorpheniramine, on proton currents in BV2 microglial cells.

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    Kim, Jiwon; Song, Jin-Ho

    2017-03-05

    Microglial NADPH oxidase is a major source of toxic reactive oxygen species produced during chronic neuroinflammation. Voltage-gated proton channel (H V 1) functions to maintain the intense activity of NADPH oxidase, and channel inhibition alleviates the pathology of neurodegenerative diseases such as ischemic stroke and multiple sclerosis associated with oxidative neuroinflammation. Antagonists of histamine H 1 receptors have beneficial effects against microglia-mediated oxidative stress and neurotoxicity. We examined the effects of the H 1 antihistamines, diphenhydramine and chlorpheniramine, on proton currents in BV2 microglial cells recorded using the whole-cell patch clamp technique. Diphenhydramine and chlorpheniramine reduced the proton currents with almost the same potency, yielding IC 50 values of 42 and 43μM, respectively. Histamine did not affect proton currents, excluding the involvement of histamine receptors in their action. Neither drug shifted the voltage-dependence of activation or the reversal potential of the proton currents, even though diphenhydramine slowed the activation and deactivation kinetics. The inhibitory effects of the two antihistamines on proton currents could be utilized to develop therapeutic agents for neurodegenerative diseases and other diseases associated with H V 1 proton channel abnormalities. Copyright © 2017 Elsevier B.V. All rights reserved.

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

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    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. [A