WorldWideScience

Sample records for astrocytic cancer cells

  1. Astrocytes derived from trisomic human embryonic stem cells express markers of astrocytic cancer cells and premalignant stem-like progenitors

    Directory of Open Access Journals (Sweden)

    Iverson Linda E

    2010-04-01

    Full Text Available Abstract Background Trisomic variants of human embryonic stem cells (hESCs arise spontaneously in culture. Although trisomic hESCs share many properties with diploid hESCs, they also exhibit features of cancer stem cells. Since most hESC-based therapies will utilize differentiated derivatives, it is imperative to investigate the potential of trisomic hESCs to undergo malignant transformation during differentiation prior to their use in the clinical setting. Methods Diploid and trisomic hESCs were differentiated into astrocytic progenitors cells (APCs, RNA extracted and hybridized to human exon-specific microarrays. Global gene expression profiles of diploid and trisomic APCs were compared to that of an astrocytoma cell line and glioblastoma samples, analyzed by others, using the same microarray platform. Results Bioinformatic analysis of microarray data indicates that differentiated trisomic APCs exhibit global expression profiles with similarities to the malignant astrocytoma cell line. An analogous trend is observed in comparison to glioblastoma samples indicating that trisomic APCs express markers of astrocytic cancer cells. The analysis also allowed identification of transcripts predicted to be differentially expressed in brain tumor stem cells. These data indicate that in vitro differentiation of trisomic hESCs along astrocytic pathways give rise to cells exhibiting properties of premalignant astrocytic stem/progenitor cells. Conclusions Given their occult nature, opportunities to study premalignant stem/progenitor cells in human have been few. The ability to propagate and direct the differentiation of aneuploid hESCs provides a powerful in vitro system for investigating biological properties of human cells exhibiting features of premalignant stem cells. This in vitro culture system can be used to elucidate changes in gene expression occurring enroute to malignant transformation and to identify molecular markers of cancer stem

  2. Reactive astrocytes promote the metastatic growth of breast cancer stem-like cells by activating Notch signalling in brain.

    Science.gov (United States)

    Xing, Fei; Kobayashi, Aya; Okuda, Hiroshi; Watabe, Misako; Pai, Sudha K; Pandey, Puspa R; Hirota, Shigeru; Wilber, Andrew; Mo, Yin-Yuan; Moore, Brian E; Liu, Wen; Fukuda, Koji; Iiizumi, Megumi; Sharma, Sambad; Liu, Yin; Wu, Kerui; Peralta, Elizabeth; Watabe, Kounosuke

    2013-03-01

    Brain metastasis of breast cancer profoundly affects the cognitive and sensory functions as well as morbidity of patients, and the 1 year survival rate among these patients remains less than 20%. However, the pathological mechanism of brain metastasis is as yet poorly understood. In this report, we found that metastatic breast tumour cells in the brain highly expressed IL-1β which then 'activated' surrounding astrocytes. This activation significantly augmented the expression of JAG1 in the astrocytes, and the direct interaction of the reactivated astrocytes and cancer stem-like cells (CSCs) significantly stimulated Notch signalling in CSCs. We also found that the activated Notch signalling in CSCs up-regulated HES5 followed by promoting self-renewal of CSCs. Furthermore, we have shown that the blood-brain barrier permeable Notch inhibitor, Compound E, can significantly suppress the brain metastasis in vivo. These results represent a novel paradigm for the understanding of how metastatic breast CSCs re-establish their niche for their self-renewal in a totally different microenvironment, which opens a new avenue to identify a novel and specific target for the brain metastatic disease.

  3. From stem cell to astrocyte: Decoding the regulation of GFAP

    NARCIS (Netherlands)

    R. Kanski

    2014-01-01

    The research presented in this thesis focuses on glial fibrillary acidic protein (GFAP), the main intermediate filament (IF) in astrocytes and astrocyte subpopulations such as neural stem cells (NSCs). In neurodegenerative diseases or upon brain damage, astrocytes respond to an injury with an upregu

  4. Knockdown of astrocyte elevated gene-1 inhibits tumor growth and modifies microRNAs expression profiles in human colorectal cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Sujun [East Department of Gastroenterology, Institute of Geriatrics, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080 (China); Southern Medical University, Guangzhou, Guangdong 510515 (China); Wu, Binwen, E-mail: wubinwengd@aliyun.com [East Department of Gastroenterology, Institute of Geriatrics, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080 (China); Li, Dongfeng; Zhou, Weihong; Deng, Gang; Zhang, Kaijun; Li, Youjia [East Department of Gastroenterology, Institute of Geriatrics, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080 (China)

    2014-02-14

    Highlights: • AEG-1 expression in CRC cell lines and down-regulation or upregulation of AEG-1 in vitro. • Knockdown of AEG-1 inhibits cell proliferation, colony formation and invasion. • Upregulation of AEG-1 enhances proliferation, invasion and colony formation. • Knockdown of AEG-1 accumulates G0/G1-phase cells and promotes apoptosis in CRC cells. • AEG-1 knockdown increases 5-FU cytotoxicity. - Abstract: Astrocyte elevated gene-1 (AEG-1), upregulated in various types of malignancies including colorectal cancer (CRC), has been reported to be associated with the carcinogenesis. MicroRNAs (miRNAs) are widely involved in the initiation and progression of cancer. However, the functional significance of AEG-1 and the relationship between AEG-1 and microRNAs in human CRC remains unclear. The aim of this study was to investigate whether AEG-1 could serve as a potential therapeutic target of human CRC and its possible mechanism. We adopted a strategy of ectopic overexpression or RNA interference to upregulate or downregulate expression of AEG-1 in CRC models. Their phenotypic changes were analyzed by Western blot, MTT and transwell matrix penetration assays. MicroRNAs expression profiles were performed using microarray analysis followed by validation using qRT-PCR. Knockdown of AEG-1 could significantly inhibit colon cancer cell proliferation, colony formation, invasion and promotes apoptosis. Conversely, upregulation of AEG-1 could significantly enhance cell proliferation, invasion and reduced apoptisis. AEG-1 directly contributes to resistance to chemotherapeutic drug. Targeted downregulation of AEG-1 might improve the expression of miR-181a-2{sup ∗}, -193b and -193a, and inversely inhibit miR-31 and -9{sup ∗}. Targeted inhibition of AEG-1 can lead to modification of key elemental characteristics, such as miRNAs, which may become a potential effective therapeutic strategy for CRC.

  5. Exposure to cadmium chloride influences astrocyte-elevated gene-1 (AEG-1) expression in MDA-MB231 human breast cancer cells.

    Science.gov (United States)

    Luparello, Claudio; Longo, Alessandra; Vetrano, Marco

    2012-01-01

    It is known that cadmium (Cd) is able to regulate gene expression, drastically affecting the pattern of transcriptional activity and intracellular signalization in normal and pathological human cells. We have already shown that Cd exerts a cytotoxic effect on neoplastic MDA-MB231 cells from the human breast, which is characterized by the onset of a "non-classical" apoptotic kind of death, impairment of mitochondrial activity and drastic changes in gene expression pattern. In the present study, employing a combination of conventional and differential display-PCR techniques, immunocytochemical, ELISA and Western analyses, we extended the knowledge on the transcriptional modulation exerted by the metal demonstrating that in MDA-MB231 cells 5 μM CdCl(2) treatment for 96 h selectively down-regulates astrocyte-elevated gene-1 (AEG-1) and reduces the accumulation of its protein product which appears to be associated with the internal cytomembranes and also present in the nucleoplasm. In addition, due to the acknowledged role of AEG-1 in the intranuclear shuttling of NF-κB p65 subunit, we also showed that CdCl(2) treatment determines the decrease of p65 amount in nuclear extracts and the down-regulation of the NF-κB downstream genes c-fos and c-jun, thus providing a new contribution to the comprehension of the intracellular molecular mechanisms implicated in Cd-breast cancer cell interactions.

  6. Astrocytes Enhance Streptococcus suis-Glial Cell Interaction in Primary Astrocyte-Microglial Cell Co-Cultures.

    Science.gov (United States)

    Seele, Jana; Nau, Roland; Prajeeth, Chittappen K; Stangel, Martin; Valentin-Weigand, Peter; Seitz, Maren

    2016-06-13

    Streptococcus (S.) suis infections are the most common cause of meningitis in pigs. Moreover, S. suis is a zoonotic pathogen, which can lead to meningitis in humans, mainly in adults. We assume that glial cells may play a crucial role in host-pathogen interactions during S. suis infection of the central nervous system. Glial cells are considered to possess important functions during inflammation and injury of the brain in bacterial meningitis. In the present study, we established primary astrocyte-microglial cell co-cultures to investigate interactions of S. suis with glial cells. For this purpose, microglial cells and astrocytes were isolated from new-born mouse brains and characterized by flow cytometry, followed by the establishment of astrocyte and microglial cell mono-cultures as well as astrocyte-microglial cell co-cultures. In addition, we prepared microglial cell mono-cultures co-incubated with uninfected astrocyte mono-culture supernatants and astrocyte mono-cultures co-incubated with uninfected microglial cell mono-culture supernatants. After infection of the different cell cultures with S. suis, bacteria-cell association was mainly observed with microglial cells and most prominently with a non-encapsulated mutant of S. suis. A time-dependent induction of NO release was found only in the co-cultures and after co-incubation of microglial cells with uninfected supernatants of astrocyte mono-cultures mainly after infection with the capsular mutant. Only moderate cytotoxic effects were found in co-cultured glial cells after infection with S. suis. Taken together, astrocytes and astrocyte supernatants increased interaction of microglial cells with S. suis. Astrocyte-microglial cell co-cultures are suitable to study S. suis infections and bacteria-cell association as well as NO release by microglial cells was enhanced in the presence of astrocytes.

  7. Comparison of the gene expression profiles of human fetal cortical astrocytes with pluripotent stem cell derived neural stem cells identifies human astrocyte markers and signaling pathways and transcription factors active in human astrocytes.

    Science.gov (United States)

    Malik, Nasir; Wang, Xiantao; Shah, Sonia; Efthymiou, Anastasia G; Yan, Bin; Heman-Ackah, Sabrina; Zhan, Ming; Rao, Mahendra

    2014-01-01

    Astrocytes are the most abundant cell type in the central nervous system (CNS) and have a multitude of functions that include maintenance of CNS homeostasis, trophic support of neurons, detoxification, and immune surveillance. It has only recently been appreciated that astrocyte dysfunction is a primary cause of many neurological disorders. Despite their importance in disease very little is known about global gene expression for human astrocytes. We have performed a microarray expression analysis of human fetal astrocytes to identify genes and signaling pathways that are important for astrocyte development and maintenance. Our analysis confirmed that the fetal astrocytes express high levels of the core astrocyte marker GFAP and the transcription factors from the NFI family which have been shown to play important roles in astrocyte development. A group of novel markers were identified that distinguish fetal astrocytes from pluripotent stem cell-derived neural stem cells (NSCs) and NSC-derived neurons. As in murine astrocytes, the Notch signaling pathway appears to be particularly important for cell fate decisions between the astrocyte and neuronal lineages in human astrocytes. These findings unveil the repertoire of genes expressed in human astrocytes and serve as a basis for further studies to better understand astrocyte biology, especially as it relates to disease.

  8. Astrocytes Upregulate Survival Genes in Tumor Cells and Induce Protection from Chemotherapy

    Directory of Open Access Journals (Sweden)

    Sun-Jin Kim

    2011-03-01

    Full Text Available In the United States, more than 40% of cancer patients develop brain metastasis. The median survival for untreated patients is 1 to 2 months, which may be extended to 6 months with conventional radiotherapy and chemotherapy. The growth and survival of metastasis depend on the interaction of tumor cells with host factors in the organ microenvironment. Brain metastases are surrounded and infiltrated by activated astrocytes and are highly resistant to chemotherapy. We report here that coculture of human breast cancer cells or lung cancer cells with murine astrocytes (but not murine fibroblasts led to the up-regulation of survival genes, including GSTA5, BCL2L1, and TWIST1, in the tumor cells. The degree of up-regulation directly correlated with increased resistance to all tested chemotherapeutic agents. We further show that the up-regulation of the survival genes and consequent resistance are dependent on the direct contact between the astrocytes and tumor cells through gap junctions and are therefore transient. Knocking down these genes with specific small interfering RNA rendered the tumor cells sensitive to chemotherapeutic agents. These data clearly demonstrate that host cells in the microenvironment influence the biologic behavior of tumor cells and reinforce the contention that the organ microenvironment must be taken into consideration during the design of therapy.

  9. Evidence for heterogeneity of astrocyte de-differentiation in vitro: astrocytes transform into intermediate precursor cells following induction of ACM from scratch-insulted astrocytes.

    Science.gov (United States)

    Yang, Hao; Qian, Xin-Hong; Cong, Rui; Li, Jing-wen; Yao, Qin; Jiao, Xi-Ying; Ju, Gong; You, Si-Wei

    2010-04-01

    Our previous study definitely demonstrated that the mature astrocytes could undergo a de-differentiation process and further transform into pluripotential neural stem cells (NSCs), which might well arise from the effect of diffusible factors released from scratch-insulted astrocytes. However, these neurospheres passaged from one neurosphere-derived from de-differentiated astrocytes possessed a completely distinct characteristic in the differentiation behavior, namely heterogeneity of differentiation. The heterogeneity in cell differentiation has become a crucial but elusive issue. In this study, we show that purified astrocytes could de-differentiate into intermediate precursor cells (IPCs) with addition of scratch-insulted astrocyte-conditioned medium (ACM) to the culture, which can express NG2 and A2B5, the IPCs markers. Apart from the number of NG2(+) and A2B5(+) cells, the percentage of proliferative cells as labeled with BrdU progressively increased with prolonged culture period ranging from 1 to 10 days. Meanwhile, the protein level of A2B5 in cells also increased significantly. These results revealed that not all astrocytes could de-differentiate fully into NSCs directly when induced by ACM, rather they generated intermediate or more restricted precursor cells that might undergo progressive de-differentiation to generate NSCs.

  10. Direct Signaling from Astrocytes to Neurons in Cultures of Mammalian Brain Cells

    Science.gov (United States)

    Nedergaard, Maiken

    1994-03-01

    Although astrocytes have been considered to be supportive, rather than transmissive, in the adult nervous system, recent studies have challenged this assumption by demonstrating that astrocytes possess functional neurotransmitter receptors. Astrocytes are now shown to directly modulate the free cytosolic calcium, and hence transmission characteristics, of neighboring neurons. When a focal electric field potential was applied to single astrocytes in mixed cultures of rat forebrain astrocytes and neurons, a prompt elevation of calcium occurred in the target cell. This in turn triggered a wave of calcium increase, which propagated from astrocyte to astrocyte. Neurons resting on these astrocytes responded with large increases in their concentration of cytosolic calcium. The gap junction blocker octanol attenuated the neuronal response, which suggests that the astrocytic-neuronal signaling is mediated through intercellular connections rather than synaptically. This neuronal response to local astrocytic stimulation may mediate local intercellular communication within the brain.

  11. Are astrocytes executive cells within the central nervous system?

    Science.gov (United States)

    Sica, Roberto E; Caccuri, Roberto; Quarracino, Cecilia; Capani, Francisco

    2016-08-01

    Experimental evidence suggests that astrocytes play a crucial role in the physiology of the central nervous system (CNS) by modulating synaptic activity and plasticity. Based on what is currently known we postulate that astrocytes are fundamental, along with neurons, for the information processing that takes place within the CNS. On the other hand, experimental findings and human observations signal that some of the primary degenerative diseases of the CNS, like frontotemporal dementia, Parkinson's disease, Alzheimer's dementia, Huntington's dementia, primary cerebellar ataxias and amyotrophic lateral sclerosis, all of which affect the human species exclusively, may be due to astroglial dysfunction. This hypothesis is supported by observations that demonstrated that the killing of neurons by non-neural cells plays a major role in the pathogenesis of those diseases, at both their onset and their progression. Furthermore, recent findings suggest that astrocytes might be involved in the pathogenesis of some psychiatric disorders as well.

  12. Astrocyte elevated gene-1 induces breast cancer proliferation and invasion through upregulating HER2/neu expression

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xin; ZHANG Ning; ZHANG Mei-xin

    2011-01-01

    Background Astrocyte elevated gene-1 (AEG-1),primarily identified as a late response gene induced by HIV-1 infection,plays multiple roles in the process of oncogenesis.This novel gene has been demonstrated to be involved in the several potent carcinogenic pathways,including PI3K/Akt pathway,nuclear factor (NF)-KB pathway,and Wnt/β-catenin pathway.Although the function of AEG-1 has been intensively investigated in recent years,the molecular mechanism underlying its oncogenic role is largely unknown.The aim of this research was to explore the potential function of AEG-1 in breast cancer development and progression.Methods AEG-1 was ectopically overexpressed in breast cancer MCF-7 cells and its biological effects on the proliferation and invasion of MCF-7 cells were studied by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and invasion assays.The expression of HER2/neu,a crucial oncogene involving in breast cancer carcinogenesis,was also determined.Results Overexpression of the AEG-1 promoted the proliferation and invasion ability of breast cancer cells,and upregulated the expression of HER2/neu,a crucial oncogene involving in breast cancer carcinogenesis.Conclusion AEG-1 might facilitate the proliferation and invasion of breast cancer cells by upregulating HER2/neu expression,which provides a potential target for breast cancer therapy.

  13. Novel cell separation method for molecular analysis of neuron-astrocyte cocultures

    Directory of Open Access Journals (Sweden)

    Andrea eGoudriaan

    2014-01-01

    Full Text Available Over the last decade, the importance of astrocyte-neuron communication in neuronal development and synaptic plasticity has become increasingly clear. Since neuron-astrocyte interactions represent highly dynamic and reciprocal processes, we hypothesized that many astrocyte genes may be regulated as a consequence of their interactions with maturing neurons. In order to identify such neuron-responsive astrocyte genes in vitro, we sought to establish an expedite technique for separation of neurons from co-cultured astrocytes. Our newly established method makes use of cold jet, which exploits different adhesion characteristics of subpopulations of cells (Jirsova et al., 1997, and is rapid, performed under ice-cold conditions and avoids protease-mediated isolation of astrocytes or time-consuming centrifugation, yielding intact astrocyte mRNA with approximately 90% of neuronal RNA removed. Using this purification method, we executed genome-wide profiling in which RNA derived from astrocyte-only cultures was compared with astrocyte RNA derived from differentiating neuron-astrocyte co-cultures. Data analysis determined that many astrocytic mRNAs and biological processes are regulated by neuronal interaction. Our results validate the cold jet as an efficient method to separate astrocytes from neurons in co-culture, and reveals that neurons induce robust gene-expression changes in co-cultured astrocytes.

  14. In vitro differentiation of cultured human CD34+ cells into astrocytes

    Directory of Open Access Journals (Sweden)

    Katari Venkatesh

    2013-01-01

    Full Text Available Background: Astrocytes are abundantly present as glial cells in the brain and play an important role in the regenerative processes. The possible role of stem cell derived astrocytes in the spinal cord injuries is possible related to their influence at the synaptic junctions. Aim: The present study is focused on in vitro differentiation of cultured human CD34+ cells into astrocytes. Materials and Methods: Granulocyte-colony stimulating factor mobilized human CD34+ cells were isolated from peripheral blood using apheresis method from a donor. These cells were further purified by fluorescence-activated cell sorting and cultured in Dulbecco′s modified eagle′s medium. Thus, cultured cells were induced with astrocyte defined medium (ADM and in the differentiated astrocytes serine/threonine protein kinases (STPK and glutamine synthetase (GLUL activities were estimated. The expression of glial fibrillary acidic protein (GFAP and GLUL were confirmed by reverse transcriptase-polymerase chain reaction (RT-PCR. Results: The cultured human CD34+ cells differentiated into astrocytes after 11 h of incubation in ADM. The RT-PCR experiment showed the expression of GLUL (1.5 kb and GFAP (2.9 kb in differentiated astrocytes. The high enzyme activities of GLUL and STPK in differentiated astrocytes compared with cultured human CD34+ cells confirmed astrocyte formation. Conclusion: In the present study, in vitro differentiation of stem cells with retinoic acid induction may result in the formation of astrocytes.

  15. "Cell therapy for stroke: use of local astrocytes"

    Directory of Open Access Journals (Sweden)

    Melek eChouchane

    2012-10-01

    Full Text Available Stroke refers to a variety of conditions caused by the occlusion or hemorrhage of blood vessels supplying the brain, which is one of the main causes of death and the leading cause of disability worldwide. In the last years, cell-based therapies have been proposed as a new approach to ameliorate post stroke deficits. However, the most appropriate type of cell to be used in such therapies, as well as their sources, remains a matter of intense research. A good candidate cell should, in principle, display high plasticity to generate diverse types of neurons and, at the same type, low risk to cause undesired outcomes, such as malignant transformation. Recently, a new approach grounded on the reprogramming of endogenous astrocytes towards neuronal fates emerged as an alternative to restore neurological functions in several central nervous system diseases. In this perspective, we review data about the potential of astrocytes to become functional neurons following expression of neurogenic genes and discuss the potential benefits and risks of reprogramming astrocytes in the glial scar to replace neurons lost after stroke.

  16. Extracellular signal-regulated kinase activation in spinal astrocytes and microglia contributes to cancer-induced bone pain in rats.

    Science.gov (United States)

    Wang, X-W; Li, T-T; Zhao, J; Mao-Ying, Q-L; Zhang, H; Hu, S; Li, Q; Mi, W-L; Wu, G-C; Zhang, Y-Q; Wang, Y-Q

    2012-08-16

    Cancer pain, especially cancer-induced bone pain, affects the quality of life of cancer patients, and current treatments for this pain are limited. The present study demonstrates that spinal extracellular signal-regulated kinase (ERK) activation in glial cells plays a crucial role in cancer-induced bone pain. From day 4 to day 21 after the intra-tibia inoculation with Walker 256 mammary gland carcinoma cells, significant mechanical allodynia was observed as indicated by the decrease of mechanical withdrawal thresholds in the von Frey hair test. Intra-tibia inoculation with carcinoma cells induced a vast and persistent (>21 D) activation of ERK in the bilateral L2-L3 and L4-L5 spinal dorsal horn. The increased pERK1/2-immunoreactivity was observed in both Iba-1-expressing microglia and GFAP-expressing astrocytes but not in NeuN-expressing neurons. A single intrathecal injection of the selective MEK (ERK kinase) inhibitors PD98059 (10 μg) on day 12 and U0126 (1.25 and 3 μg) on day 14, attenuated the bilateral mechanical allodynia in the von Frey hair test. Altogether, our results suggest that ERK activation in spinal microglia and astrocytes is correlated with the onset of allodynia and is important for allodynia maintenance in the cancer pain model. This study indicated that inhibition of the ERK pathway may provide a new therapy for cancer-induced bone pain.

  17. Astrocytes in Migration.

    Science.gov (United States)

    Zhan, Jiang Shan; Gao, Kai; Chai, Rui Chao; Jia, Xi Hua; Luo, Dao Peng; Ge, Guo; Jiang, Yu Wu; Fung, Yin-Wan Wendy; Li, Lina; Yu, Albert Cheung Hoi

    2017-01-01

    Cell migration is a fundamental phenomenon that underlies tissue morphogenesis, wound healing, immune response, and cancer metastasis. Great progresses have been made in research methodologies, with cell migration identified as a highly orchestrated process. Brain is considered the most complex organ in the human body, containing many types of neural cells with astrocytes playing crucial roles in monitoring normal functions of the central nervous system. Astrocytes are mostly quiescent under normal physiological conditions in the adult brain but become migratory after injury. Under most known pathological conditions in the brain, spinal cord and retina, astrocytes are activated and become hypertrophic, hyperplastic, and up-regulating GFAP based on the grades of severity. These three observations are the hallmark in glia scar formation-astrogliosis. The reactivation process is initiated with structural changes involving cell process migration and ended with cell migration. Detailed mechanisms in astrocyte migration have not been studied extensively and remain largely unknown. Here, we therefore attempt to review the mechanisms in migration of astrocytes.

  18. Nanoscale Properties of Neural Cell Prosthetic and Astrocyte Response

    Science.gov (United States)

    Flowers, D. A.; Ayres, V. M.; Delgado-Rivera, R.; Ahmed, I.; Meiners, S. A.

    2009-03-01

    Preliminary data from in-vivo investigations (rat model) suggest that a nanofiber prosthetic device of fibroblast growth factor-2 (FGF-2)-modified nanofibers can correctly guide regenerating axons across an injury gap with aligned functional recovery. Scanning Probe Recognition Microscopy (SPRM) with auto-tracking of individual nanofibers is used for investigation of the key nanoscale properties of the nanofiber prosthetic device for central nervous system tissue engineering and repair. The key properties under SPRM investigation include nanofiber stiffness and surface roughness, nanofiber curvature, nanofiber mesh density and porosity, and growth factor presentation and distribution. Each of these factors has been demonstrated to have global effects on cell morphology, function, proliferation, morphogenesis, migration, and differentiation. The effect of FGF-2 modification on the key nanoscale properties is investigated. Results from the nanofiber prosthetic properties investigations are correlated with astrocyte response to unmodified and FGF-2 modified scaffolds, using 2D planar substrates as a control.

  19. Evaluation of the importance of astrocytes when screening for acute toxicity in neuronal cell systems.

    Science.gov (United States)

    Woehrling, E K; Hill, E J; Coleman, M D

    2010-02-01

    Reliable, high throughput, in vitro preliminary screening batteries have the potential to greatly accelerate the rate at which regulatory neurotoxicity data is generated. This study evaluated the importance of astrocytes when predicting acute toxic potential using a neuronal screening battery of pure neuronal (NT2.N) and astrocytic (NT2.A) and integrated neuronal/astrocytic (NT2.N/A) cell systems derived from the human NT2.D1 cell line, using biochemical endpoints (mitochondrial membrane potential (MMP) depolarisation and ATP and GSH depletion). Following exposure for 72 h, the known acute human neurotoxicants trimethyltin-chloride, chloroquine and 6-hydroxydopamine were frequently capable of disrupting biochemical processes in all of the cell systems at non-cytotoxic concentrations. Astrocytes provide key metabolic and protective support to neurons during toxic challenge in vivo and generally the astrocyte containing cell systems showed increased tolerance to toxicant insult compared with the NT2.N mono-culture in vitro. Whilst there was no consistent relationship between MMP, ATP and GSH log IC(50) values for the NT2.N/A and NT2.A cell systems, these data did provide preliminary evidence of modulation of the acute neuronal toxic response by astrocytes. In conclusion, the suitability of NT2 neurons and astrocytes as cell systems for acute toxicity screening deserves further investigation.

  20. [Amyotrophic lateral sclerosis: is the astrocyte the cell primarily involved?].

    Science.gov (United States)

    Sica, Roberto E

    2013-01-01

    So far, amyotrophic lateral sclerosis (ALS) is thought as due to a primary insult of the motor neurons. None of its pathogenic processes proved to be the cause of the illness, nor can be blamed environmental agents. Motor neurons die by apoptosis, leaving the possibility that their death might be due to an unfriendly environment, unable to sustain their health, rather than being directly targeted themselves. These reasons justify an examination of the astrocytes, because they have the most important role controlling the neurons' environment. It is known that astrocytes are plastic, enslaving their functions to the requirements of the neurons to which they are related. Each population of astrocytes is unique, and if it were affected the consequences would reach the neurons that it normally sustains. In regard to the motor neurons, this situation would lead to a disturbed production and release of astrocytic neurotransmitters and transporters, impairing nutritional and trophic support as well. For explaining the spreading of muscle symptoms in ALS, correlated with the type of spreading observed at the cortical and spinal motor neurons pools, the present hypotheses suggests that the illness-causing process is spreading among astrocytes, through their gap junctions, depriving the motor neurons of their support. Also it is postulated that a normal astrocytic protein becomes misfolded and infectious, inducing the misfolding of its wild type, travelling from one protoplasmatic astrocyte to another and to the fibrous astrocytes encircling the pyramidal pathway which joints the upper and lower motoneurones.

  1. A Cellular Star Atlas: Using Astrocytes from Human Pluripotent Stem Cells for Disease Studies

    Directory of Open Access Journals (Sweden)

    Robert eKrencik

    2013-03-01

    Full Text Available What roles do astrocytes play in human disease? This question remains unanswered for nearly every human neurological disorder. Yet, because of their abundance and complexity astrocytes can impact neurological function in many ways. The differentiation of human pluripotent stem cells (hPSCs into neuronal and glial subtypes, including astrocytes, is becoming routine, thus their use as tools for modeling neurodevelopment and disease will provide one important approach to answer this question. When designing experiments, careful consideration must be given to choosing paradigms for differentiation, maturation, and functional analysis of these temporally asynchronous cellular populations in culture. In the case of astrocytes, they display heterogeneous characteristics depending upon species of origin, brain region, developmental stage, environmental factors, and disease states, all of which may render experimental results highly variable. In this review, challenges and future directions are discussed for using hPSC-derived astroglial progenitors and mature astrocytes for neurodevelopmental studies with a focus on exploring human astrocyte effects upon neuronal function. As new technologies emerge to measure the functions of astrocytes in vitro and in vivo, there is also a need for a standardized source of human astrocytes that are most relevant to the diseases of interest.

  2. Astrocyte-like glial cells physiologically regulate olfactory processing through the modification of ORN-PN synaptic strength in Drosophila.

    Science.gov (United States)

    Liu, He; Zhou, Bangyu; Yan, Wenjun; Lei, Zhengchang; Zhao, Xiaoliang; Zhang, Ke; Guo, Aike

    2014-09-01

    Astrocyte-like glial cells are abundant in the central nervous system of adult Drosophila and exhibit morphology similar to astrocytes of mammals. Previous evidence has shown that astrocyte-like glial cells are strongly associated with synapses in the antennal lobe (AL), the first relay of the olfactory system, where olfactory receptor neurons (ORNs) transmit information into projection neurons (PNs). However, the function of astrocyte-like glia in the AL remains obscure. In this study, using in vivo calcium imaging, we found that astrocyte-like glial cells exhibited spontaneous microdomain calcium elevations. Using simultaneous manipulation of glial activity and monitoring of neuronal function, we found that the astrocyte-like glial activation, but not ensheathing glial activation, could inhibit odor-evoked responses of PNs. Ensheathing glial cells are another subtype of glia, and are of functional importance in the AL. Electrophysiological experiments indicated that astrocyte-like glial activation decreased the amplitude and slope of excitatory postsynaptic potentials evoked through electrical stimulation of the antennal nerve. These results suggest that astrocyte-like glial cells may regulate olfactory processing through negative regulation of ORN-PN synaptic strength. Beyond the antennal lobe we observed astrocyte-like glial spontaneous calcium activities in the ventromedial protocerebrum, indicating that astrocyte-like glial spontaneous calcium elevations might be general in the adult fly brain. Overall, our study demonstrates a new function for astrocyte-like glial cells in the physiological modulation of olfactory information transmission, possibly through regulating ORN-PN synapse strength.

  3. Transplantation of stem cell-derived astrocytes for thetreatment of amyotrophic lateral sclerosis and spinal cordinjury

    Institute of Scientific and Technical Information of China (English)

    Charles Nicaise; Dinko Mitrecic; Aditi Falnikar; Angelo C Lepore

    2015-01-01

    Neglected for years, astrocytes are now recognized tofulfill and support many, if not all, homeostatic functionsof the healthy central nervous system (CNS). Duringneurodegenerative diseases such as amyotrophiclateral sclerosis (ALS) and spinal cord injury (SCI),astrocytes in the vicinity of degenerating areasundergo both morphological and functional changesthat might compromise their intrinsic properties.Evidence from human and animal studies show thatdeficient astrocyte functions or loss-of-astrocytes largelycontribute to increased susceptibility to cell death forneurons, oligodendrocytes and axons during ALS andSCI disease progression. Despite exciting advances inexperimental CNS repair, most of current approachesthat are translated into clinical trials focus on thereplacement or support of spinal neurons throughstem cell transplantation, while none focus on thespecific replacement of astroglial populations. Knowingthe important functions carried out by astrocytesin the CNS, astrocyte replacement-based therapiesmight be a promising approach to alleviate overallastrocyte dysfunction, deliver neurotrophic support todegenerating spinal tissue and stimulate endogenousCNS repair abilities. Enclosed in this review, we gatheredexperimental evidence that argue in favor of astrocytetransplantation during ALS and SCI. Based on theirintrinsic properties and according to the cell typetransplanted, astrocyte precursors or stem cell-derivedastrocytes promote axonal growth, support mechanismsand cells involved in myelination, are able to modulatethe host immune response, deliver neurotrophic factorsand provide protective molecules against oxidative orexcitotoxic insults, amongst many possible benefits.Embryonic or adult stem cells can even be geneticallyengineered in order to deliver missing gene productsand therefore maximize the chance of neuroprotectionand functional recovery. However, before broad clinicaltranslation, further preclinical data on safety

  4. Astrocyte differentiation of human pluripotent stem cells: new tools for neurological disorder research

    Directory of Open Access Journals (Sweden)

    Abinaya Chandrasekaran

    2016-09-01

    Full Text Available Astrocytes have a central role in brain development and function, and so have gained increasing attention over the past two decades. Consequently, our knowledge about their origin, differentiation and function has increased significantly, with new research showing that astrocytes cultured alone or co-cultured with neurons have the potential to improve our understanding of various central nervous system (CNS diseases, such as Amyotrophic lateral sclerosis, Alzheimer’s disease or Alexander disease. The generation of astrocytes derived from pluripotent stem cells (PSCs opens up a new area for studying neurologic diseases in vitro; these models could be exploited to identify and validate potential drugs by detecting adverse effects in the early stages of drug development. However, as it is now known that a range of astrocyte populations exist in the brain, it will be important in vitro to develop standardized protocols for the in vitro generation of astrocyte subsets with defined maturity status and phenotypic properties. This will then open new possibilities for co-cultures with neurons and the generation of neural organoids for research purposes. The aim of this review article is to compare and summarize the currently available protocols and their strategies to generate human astrocytes from PSCs. Furthermore, we discuss the potential role of human-induced PSCs derived astrocytes in disease modeling.

  5. Heterogeneity of astrocytes: from development to injury - single cell gene expression.

    Directory of Open Access Journals (Sweden)

    Vendula Rusnakova

    Full Text Available Astrocytes perform control and regulatory functions in the central nervous system; heterogeneity among them is still a matter of debate due to limited knowledge of their gene expression profiles and functional diversity. To unravel astrocyte heterogeneity during postnatal development and after focal cerebral ischemia, we employed single-cell gene expression profiling in acutely isolated cortical GFAP/EGFP-positive cells. Using a microfluidic qPCR platform, we profiled 47 genes encoding glial markers and ion channels/transporters/receptors participating in maintaining K(+ and glutamate homeostasis per cell. Self-organizing maps and principal component analyses revealed three subpopulations within 10-50 days of postnatal development (P10-P50. The first subpopulation, mainly immature glia from P10, was characterized by high transcriptional activity of all studied genes, including polydendrocytic markers. The second subpopulation (mostly from P20 was characterized by low gene transcript levels, while the third subpopulation encompassed mature astrocytes (mainly from P30, P50. Within 14 days after ischemia (D3, D7, D14, additional astrocytic subpopulations were identified: resting glia (mostly from P50 and D3, transcriptionally active early reactive glia (mainly from D7 and permanent reactive glia (solely from D14. Following focal cerebral ischemia, reactive astrocytes underwent pronounced changes in the expression of aquaporins, nonspecific cationic and potassium channels, glutamate receptors and reactive astrocyte markers.

  6. Globular adiponectin induces a pro-inflammatory response in human astrocytic cells

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Zhongxiao; Mah, Dorrian; Simtchouk, Svetlana [School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, BC (Canada); Klegeris, Andis [Department of Biology, University of British Columbia Okanagan, Kelowna, BC (Canada); Little, Jonathan P., E-mail: jonathan.little@ubc.ca [School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, BC (Canada)

    2014-03-28

    Highlights: • Adiponectin receptors are expressed in human astrocytes. • Globular adiponectin induces secretion of IL-6 and MCP-1 from cultured astrocytes. • Adiponectin may play a pro-inflammatory role in astrocytes. - Abstract: Neuroinflammation, mediated in part by activated brain astrocytes, plays a critical role in the development of neurodegenerative disorders, including Alzheimer’s disease (AD). Adiponectin is the most abundant adipokine secreted from adipose tissue and has been reported to exert both anti- and pro-inflammatory effects in peripheral tissues; however, the effects of adiponectin on astrocytes remain unknown. Shifts in peripheral concentrations of adipokines, including adiponectin, could contribute to the observed link between midlife adiposity and increased AD risk. The aim of the present study was to characterize the effects of globular adiponectin (gAd) on pro-inflammatory cytokine mRNA expression and secretion in human U373 MG astrocytic cells and to explore the potential involvement of nuclear factor (NF)-κB, p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase (ERK)1/2, c-Jun N-terminal kinase (JNK) and phosphatidylinositide 3-kinases (PI3 K) signaling pathways in these processes. We demonstrated expression of adiponectin receptor 1 (adipoR1) and adipoR2 in U373 MG cells and primary human astrocytes. gAd induced secretion of interleukin (IL)-6 and monocyte chemoattractant protein (MCP)-1, and gene expression of IL-6, MCP-1, IL-1β and IL-8 in U373 MG cells. Using specific inhibitors, we found that NF-κB, p38MAPK and ERK1/2 pathways are involved in gAd-induced induction of cytokines with ERK1/2 contributing the most. These findings provide evidence that gAd may induce a pro-inflammatory phenotype in human astrocytes.

  7. Effects of lipopolysaccharide on oligodendrocyte progenitor cells are mediated by astrocytes and microglia.

    Science.gov (United States)

    Pang, Y; Cai, Z; Rhodes, P G

    2000-11-15

    Oligodendrocytes are the primary cells injured in periventricular leukomalacia (PVL), a predominant form of brain white matter lesion in preterm infants. To explore the possible linkage between white matter injury and maternal infection, purified rat O-2A progenitor (Oligodendrocyte-type 2 astrocyte progenitor) cell cultures were used as a model in studying the effects of lipopolysaccharide (LPS), an endotoxin, on survival and differentiation of oligodendrocytes and the involvement of other glial cells in the effects of LPS. O-2A progenitor cells were cultured from optic nerves of 7-day-old rat pups in a chemically defined medium (CDM). Astrocyte and microglia cell cultures were prepared from the cortex of 1-day-old rat brains in the CDM. Direct treatment of LPS (1 microg/ml) to O-2A cells had no effect on viability or differentiation of these cells. When O-2A progenitor cells were cultured in the conditioned medium obtained from either astrocyte or microglial cell cultures for 48 hr, survival rate and differentiation of O-2A cells into mature oligodendrocytes were greatly enhanced as measured by the MTT assay and immunocytochemistry. The conditioned medium obtained from astrocytes or microglia treated with LPS for 48 hr, however, failed to show such a promotional effect on viability and differentiation of O-2A cells. When 5 microg/ml LPS was used to stimulate astrocytes or microglia, the conditioned medium from these glial cell cultures caused O-2A cell injury. The overall results indicate that astrocytes and microglia may promote viability and differentiation of O-2A progenitor cells under physiological conditions, but they may also mediate cytotoxic effects of LPS on oligodendrocytes under an infectious disease biochemical environment.

  8. Construction and identification of immortalized rat astrocyte cell line expressing enkephalin

    Institute of Scientific and Technical Information of China (English)

    XU Ying; TIAN Yu-ke; TIAN Xue-bi; AN Ke; YANG Hui

    2007-01-01

    Objective: To provide a sound cell source for further ex-vivo gene therapy for chronic pain, we attempt to develop an immortalized rat astrocyte cell line that expresses enkephalin regulated by doxycycline.Methods: Retrovirus infection method was employed to develop an immortalized rat astrocyte cell line that could express enkephalin regulated by doxycycline. The hPPE gene expression level of immoralized astroyte cells (IAC)/hPPE was detected by RT-PCR, indirect immunofiuorescence staining and radioimmunoassay.Results: IAC carrying Tet-on system transfected with preproenkephalin gene could secrete enkephalin that was regulated by doxycycline in a dose-dependent manner and hPPE gene activation could be repeated in on-off-on cycles through administration or removal of doxycycline.Conclusion: An immortalized rat astrocyte cell line that secrete enkephalin under the control of doxycycline is established successfully, which provides a research basis for transgenic cell transplantation for analgesia.

  9. Antidepressant imipramine induces human astrocytes to differentiate into cells with neuronal phenotype.

    Science.gov (United States)

    Cabras, Stefano; Saba, Francesca; Reali, Camilla; Scorciapino, Maria Laura; Sirigu, Annarita; Talani, Giuseppe; Biggio, Giovanni; Sogos, Valeria

    2010-06-01

    Several recent studies have expanded our conception of the role of astrocytes in neurogenesis, proposing that these cells may contribute to this phenomenon not only as a source of trophic substances, but also as stem cells themselves. We recently observed in vitro that human mature astrocytes can be induced to differentiate into cells with a neuronal phenotype. Antidepressant drugs have been shown to increase neurogenesis in the adult rodent hippocampus. In order to better understand the role of astroglia in antidepressant-induced neurogenesis, primary astrocyte cultures were treated with the antidepressant imipramine. Cell morphology was rapidly modified by treatment. In fact, whereas untreated astrocytes showed large, flat morphology, after a few hours of treatment cells exhibited a round-shaped cell body with long, thin processes. The expression of neuronal markers was analysed by immunocytochemistry, Western Blot and RT-PCR at different treatment times. Results showed an increase in neuronal markers such as neurofilament and neuron-specific enolase (NSE), whereas glial fibrillary acidic protein (GFAP) and nestin expression were not significantly modified by treatment. Similar results were obtained with fluoxetine and venlafaxine. Hes1 mRNA significantly increased after 2 h of treatment, suggesting involvement of this transcription factor in this process. These results confirm the role of astrocytes in neurogenesis and suggest that these cells may represent one of the targets of antidepressants.

  10. Non-cell autonomous influence of the astrocyte system xc− on hypoglycaemic neuronal cell death

    Directory of Open Access Journals (Sweden)

    Sandra J Hewett

    2012-02-01

    Full Text Available Despite longstanding evidence that hypoglycaemic neuronal injury is mediated by glutamate excitotoxicity, the cellular and molecular mechanisms involved remain incompletely defined. Here, we demonstrate that the excitotoxic neuronal death that follows GD (glucose deprivation is initiated by glutamate extruded from astrocytes via system xc− – an amino acid transporter that imports l-cystine and exports l-glutamate. Specifically, we find that depriving mixed cortical cell cultures of glucose for up to 8 h injures neurons, but not astrocytes. Neuronal death is prevented by ionotropic glutamate receptor antagonism and is partially sensitive to tetanus toxin. Removal of amino acids during the deprivation period prevents – whereas addition of l-cystine restores – GD-induced neuronal death, implicating the cystine/glutamate antiporter, system xc−. Indeed, drugs known to inhibit system xc− ameliorate GD-induced neuronal death. Further, a dramatic reduction in neuronal death is observed in chimaeric cultures consisting of neurons derived from WT (wild-type mice plated on top of astrocytes derived from sut mice, which harbour a naturally occurring null mutation in the gene (Slc7a11 that encodes the substrate-specific light chain of system xc− (xCT. Finally, enhancement of astrocytic system xc− expression and function via IL-1β (interleukin-1β exposure potentiates hypoglycaemic neuronal death, the process of which is prevented by removal of l-cystine and/or addition of system xc− inhibitors. Thus, under the conditions of GD, our studies demonstrate that astrocytes, via system xc−, have a direct, non-cell autonomous effect on cortical neuron survival.

  11. Non-cell autonomous influence of the astrocyte system xc- on hypoglycaemic neuronal cell death.

    Science.gov (United States)

    Jackman, Nicole A; Melchior, Shannon E; Hewett, James A; Hewett, Sandra J

    2012-02-08

    Despite longstanding evidence that hypoglycaemic neuronal injury is mediated by glutamate excitotoxicity, the cellular and molecular mechanisms involved remain incompletely defined. Here, we demonstrate that the excitotoxic neuronal death that follows GD (glucose deprivation) is initiated by glutamate extruded from astrocytes via system xc---an amino acid transporter that imports L-cystine and exports L-glutamate. Specifically, we find that depriving mixed cortical cell cultures of glucose for up to 8 h injures neurons, but not astrocytes. Neuronal death is prevented by ionotropic glutamate receptor antagonism and is partially sensitive to tetanus toxin. Removal of amino acids during the deprivation period prevents--whereas addition of L-cystine restores--GD-induced neuronal death, implicating the cystine/glutamate antiporter, system xc-. Indeed, drugs known to inhibit system xc- ameliorate GD-induced neuronal death. Further, a dramatic reduction in neuronal death is observed in chimaeric cultures consisting of neurons derived from WT (wild-type) mice plated on top of astrocytes derived from sut mice, which harbour a naturally occurring null mutation in the gene (Slc7a11) that encodes the substrate-specific light chain of system xc- (xCT). Finally, enhancement of astrocytic system xc- expression and function via IL-1β (interleukin-1β) exposure potentiates hypoglycaemic neuronal death, the process of which is prevented by removal of l-cystine and/or addition of system xc- inhibitors. Thus, under the conditions of GD, our studies demonstrate that astrocytes, via system xc-, have a direct, non-cell autonomous effect on cortical neuron survival.

  12. Non-Cell Autonomous Influence of the Astrocyte System xc − on Hypoglycaemic Neuronal Cell Death

    Directory of Open Access Journals (Sweden)

    Nicole A Jackman

    2012-01-01

    Full Text Available Despite longstanding evidence that hypoglycaemic neuronal injury is mediated by glutamate excitotoxicity, the cellular and molecular mechanisms involved remain incompletely defined. Here, we demonstrate that the excitotoxic neuronal death that follows GD (glucose deprivation is initiated by glutamate extruded from astrocytes via system xc −– – an amino acid transporter that imports L-cystine and exports L-glutamate. Specifically, we find that depriving mixed cortical cell cultures of glucose for up to 8 h injures neurons, but not astrocytes. Neuronal death is prevented by ionotropic glutamate receptor antagonism and is partially sensitive to tetanus toxin. Removal of amino acids during the deprivation period prevents – whereas addition of L-cystine restores – GD-induced neuronal death, implicating the cystine/glutamate antiporter, system xc−–. Indeed, drugs known to inhibit system xc −– ameliorate GD-induced neuronal death. Further, a dramatic reduction in neuronal death is observed in chimaeric cultures consisting of neurons derived from WT (wild-type mice plated on top of astrocytes derived from sut mice, which harbour a naturally occurring null mutation in the gene (Slc7a11 that encodes the substrate-specific light chain of system xc −– (xCT. Finally, enhancement of astrocytic system xc −– expression and function via IL-1β (interleukin-1β exposure potentiates hypoglycaemic neuronal death, the process of which is prevented by removal of L-cystine and/or addition of system xc −– inhibitors. Thus, under the conditions of GD, our studies demonstrate that astrocytes, via system xc −–, have a direct, non-cell autonomous effect on cortical neuron survival.

  13. Quantification of Metabolic Rearrangements During Neural Stem Cells Differentiation into Astrocytes by Metabolic Flux Analysis.

    Science.gov (United States)

    Sá, João V; Kleiderman, Susanne; Brito, Catarina; Sonnewald, Ursula; Leist, Marcel; Teixeira, Ana P; Alves, Paula M

    2017-01-01

    Proliferation and differentiation of neural stem cells (NSCs) have a crucial role to ensure neurogenesis and gliogenesis in the mammalian brain throughout life. As there is growing evidence for the significance of metabolism in regulating cell fate, knowledge on the metabolic programs in NSCs and how they evolve during differentiation into somatic cells may provide novel therapeutic approaches to address brain diseases. In this work, we applied a quantitative analysis to assess how the central carbon metabolism evolves upon differentiation of NSCs into astrocytes. Murine embryonic stem cell (mESC)-derived NSCs and astrocytes were incubated with labelled [1-(13)C]glucose and the label incorporation into intracellular metabolites was followed by GC-MS. The obtained (13)C labelling patterns, together with uptake/secretion rates determined from supernatant analysis, were integrated into an isotopic non-stationary metabolic flux analysis ((13)C-MFA) model to estimate intracellular flux maps. Significant metabolic differences between NSCs and astrocytes were identified, with a general downregulation of central carbon metabolism during astrocytic differentiation. While glucose uptake was 1.7-fold higher in NSCs (on a per cell basis), a high lactate-secreting phenotype was common to both cell types. Furthermore, NSCs consumed glutamine from the medium; the highly active reductive carboxylation of alpha-ketoglutarate indicates that this was converted to citrate and used for biosynthetic purposes. In astrocytes, pyruvate entered the TCA cycle mostly through pyruvate carboxylase (81%). This pathway supported glutamine and citrate secretion, recapitulating well described metabolic features of these cells in vivo. Overall, this fluxomics study allowed us to quantify the metabolic rewiring accompanying astrocytic lineage specification from NSCs.

  14. Cell death pathways in astrocytes with a modified model of oxygen-glucose deprivation.

    Directory of Open Access Journals (Sweden)

    Qiaoying Huang

    Full Text Available Traditional oxygen-glucose deprivation (OGD models do not produce sufficiently stable and continuous deprivation to induce cell death in the ischemic core. Therefore, we modified the OGD model to mimic the observed damage in the ischemic core following stroke and utilized this new model to study cell death pathways in astrocytes. The PO2 and pH levels in the astrocyte culture medium were compared between a physical OGD group, a chemical OGD group and a mixed OGD group. The mixed OGD group was able to maintain anaerobic conditions in astrocyte culture medium for 6 h, while the physical and the chemical groups failed to maintain such conditions. Astrocyte viability decreased and LDH release into in the medium increased as a function of exposure to OGD. Compared to the control group, the expression of active caspase-3 in the mixed OGD group increased within 2 h after OGD, but decreased after 2 h of OGD. Additionally, porimin mRNA levels did not significantly increase during the first 2 h of OGD, while bcl-2 mRNA levels decreased at 1 h. However, both porimin and bcl-2 mRNA levels increased after 2 h of OGD; interestingly, they both suddenly decreased at 4 h of OGD. Taken together, these results indicate that apoptosis and oncosis are the two cell death pathways responsible for astrocyte death in the ischemic core. However, the main death pathway varies depending on the OGD period.

  15. Insulin promotes glycogen storage and cell proliferation in primary human astrocytes.

    Directory of Open Access Journals (Sweden)

    Martin Heni

    Full Text Available INTRODUCTION: In the human brain, there are at least as many astrocytes as neurons. Astrocytes are known to modulate neuronal function in several ways. Thus, they may also contribute to cerebral insulin actions. Therefore, we examined whether primary human astrocytes are insulin-responsive and whether their metabolic functions are affected by the hormone. METHODS: Commercially available Normal Human Astrocytes were grown in the recommended medium. Major players in the insulin signaling pathway were detected by real-time RT-PCR and Western blotting. Phosphorylation events were detected by phospho-specific antibodies. Glucose uptake and glycogen synthesis were assessed using radio-labeled glucose. Glycogen content was assessed by histochemistry. Lactate levels were measured enzymatically. Cell proliferation was assessed by WST-1 assay. RESULTS: We detected expression of key proteins for insulin signaling, such as insulin receptor β-subunit, insulin receptor substrat-1, Akt/protein kinase B and glycogen synthase kinase 3, in human astrocytes. Akt was phosphorylated and PI-3 kinase activity increased following insulin stimulation in a dose-dependent manner. Neither increased glucose uptake nor lactate secretion after insulin stimulation could be evidenced in this cell type. However, we found increased insulin-dependent glucose incorporation into glycogen. Furthermore, cell numbers increased dose-dependently upon insulin treatment. DISCUSSION: This study demonstrated that human astrocytes are insulin-responsive at the molecular level. We identified glycogen synthesis and cell proliferation as biological responses of insulin signaling in these brain cells. Hence, this cell type may contribute to the effects of insulin in the human brain.

  16. Death and survival of neuronal and astrocytic cells in ischemic brain injury: a role of autophagy

    Institute of Scientific and Technical Information of China (English)

    Min XU; Hui-ling ZHANG

    2011-01-01

    Autophagy is a highly regulated cellular mechanism that leads to degradation of long-lived proteins and dysfunctional organelles. The process has been implicated in a variety of physiological and pathological conditions relevant to neurological diseases. Recent studies show the existence of autophagy in cerebral ischemia, but no consensus has yet been reached regarding the functions of autophagy in this condition. This article highlights the activation of autophagy during cerebral ischemia and/or reperfusion, especially in neurons and astrocytes, as well as the role of autophagy in neuronal or astrocytic cell death and survival. We propose that physiological levels of autophagy, presumably caused by mild to modest hypoxia or ischemia, appear to be protective. However, high levels of autophagy caused by severe hypoxia or ischemia and/or reperfusion may cause self-digestion and eventual neuronal and astrocytic cell death. We also discuss that oxidative and endoplasmic reticulum (ER) stresses in cerebral hypoxia or ischemia and/or reperfusion are potent stimuli of autophagy in neurons and astrocytes. In addition, we review the evidence suggesting a considerable overlap between autophagy on one hand, and apoptosis, necrosis and necroptosis on the other hand, in determining the outcomes and final morphology of damaged neurons and astrocytes.

  17. Reactive Astrocytes: Phenotypic and Functional Characteristics and Astrocytes as Neural Stem Cells

    Science.gov (United States)

    2006-01-01

    proteins, and contained inclusion bodies identical both histologically and antigenically to the Rosenthal fibers of Alexander’s disease (Messing et al...observations. The most notable were from Koelliker, His, and Ramón y Cajal (Koelliker, 1896; His, 1904; Ramón y Cajal , 1999; Gross, 2000). Using...layer and into the molecular layer with the cell body generally located in the granule cell layer. EM evaluation of type 1 cells showed vascular end

  18. Purinergic P2X7 receptors mediate cell death in mouse cerebellar astrocytes in culture.

    Science.gov (United States)

    Salas, Elvira; Carrasquero, Luz María G; Olivos-Oré, Luis A; Bustillo, Diego; Artalejo, Antonio R; Miras-Portugal, Maria Teresa; Delicado, Esmerilda G

    2013-12-01

    The brain distribution and functional role of glial P2X7 receptors are broader and more complex than initially anticipated. We characterized P2X7 receptors from cerebellar astrocytes at the molecular, immunocytochemical, biophysical, and cell physiologic levels. Mouse cerebellar astrocytes in culture express mRNA coding for P2X7 receptors, which is translated into P2X7 receptor protein as proven by Western blot analysis and immunocytochemistry. Fura-2 imaging showed cytosolic calcium responses to ATP and the synthetic analog 3'-O-(4-benzoyl)benzoyl-ATP (BzATP) exhibited two components, namely an initial transient and metabotropic component followed by a sustained one that depended on extracellular calcium. This latter component, which was absent in astrocytes from P2X7 receptor knockout mice (P2X7 KO), was modulated by extracellular Mg(2+), and was sensitive to Brilliant Blue G (BBG) and 3-(5-(2,3-dichlorophenyl)-1H-tetrazol-1-yl)methyl pyridine (A438079) antagonism. BzATP also elicited inwardly directed nondesensitizing whole-cell ionic currents that were reduced by extracellular Mg(2+) and P2X7 antagonists (BBG and calmidazolium). In contrast to that previously reported in rat cerebellar astrocytes, sustained BzATP application induced a gradual increase in membrane permeability to large cations, such as N-methyl-d-glucamine and 4-[3-methyl-2(3H)-benzoxazolylidene)-methyl]-1-[3-(triethylammonio)propyl]diiodide, which ultimately led to the death of mouse astrocytes. Cerebellar astrocyte cell death was prevented by BBG but not by calmidazolium, removal of extracellular calcium, or treatment with the caspase-3 inhibitor, benzyloxycarbonyl-Asp(OMe)-Glu(OMe)-Val-Asp(OMe)-fluoromethylketone, thus suggesting a necrotic-type mechanism of cell death. Since this cellular response was not observed in astrocytes from P2X7 KO mice, this study suggests that stimulation of P2X7 receptor may convey a cell death signal to cerebellar astrocytes in a species-specific manner.

  19. Cerebellar stem cells do not produce neurons and astrocytes in adult mouse

    Energy Technology Data Exchange (ETDEWEB)

    Su, Xin; Guan, Wuqiang; Yu, Yong-Chun; Fu, Yinghui, E-mail: fuyh@fudan.edu.cn

    2014-07-18

    Highlights: • No new neurons and astrocytes are generated in adult mouse cerebellum. • Very few mash1{sup +} or nestin{sup +} stem cells exist, and most of them are quiescent. • Cell proliferation rate is diversified among cerebellar regions and decreases over time. - Abstract: Although previous studies implied that cerebellar stem cells exist in some adult mammals, little is known about whether these stem cells can produce new neurons and astrocytes. In this study by bromodeoxyuridine (BrdU) intraperitoneal (i.p.) injection, we found that there are abundant BrdU{sup +} cells in adult mouse cerebellum, and their quantity and density decreases significantly over time. We also found cell proliferation rate is diversified in different cerebellar regions. Among these BrdU{sup +} cells, very few are mash1{sup +} or nestin{sup +} stem cells, and the vast majority of cerebellar stem cells are quiescent. Data obtained by in vivo retrovirus injection indicate that stem cells do not produce neurons and astrocytes in adult mouse cerebellum. Instead, some cells labeled by retrovirus are Iba1{sup +} microglia. These results indicate that very few stem cells exist in adult mouse cerebellum, and none of these stem cells contribute to neurogenesis and astrogenesis under physiological condition.

  20. An experimental study on astrocytes promoting production of neural stem cells derived from mouse embryonic stem cells

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yu-feng; FANG Feng; FU Jin-rong; DONG Yong-sui; YE Du-yun; SHU Sai-nan; ZHEN Hong; LI Ge

    2005-01-01

    Background The production of neural stem cells (NSCs) derived from embryonic stem (ES) cells was usually very low according to previous studies, which was a major obstacle for meeting the needs of clinical application. This study aimed at investigating whether astrocytes could promote production of NSCs derived from ES cells in vitro.Methods Mouse ES cells line-D3 was used to differentiate into NSCs with astrocytes as inducing stromal cells by means of three-stage differentiation procedure. Another group without astrocytes served as control. The totipotency of ES cells was identified by observation of cells' morphology and formation of teratoma in severe combined immunodeficiency disease (SCID) mice. The quantity and purity of NSCs derived from ES cells were analyzed using clonogenic assay, immunohistochemical staining and flow cytometry assay. The plasticity of NSCs was detected by differentiating test. Octamer-binding transcription factor 4 (Oct-4) and nestin, the specific marker genes of ES cells and NSCs respectively, were detected continuously using reverse transcription-polymerase chain reaction (RT-PCR) method to monitor the process of cell differentiation. Results The ES cells of D3 line could maintain the ability of differentiating into cellular derivations of all three primary germ layers after continuous passage culture. At the end of two-stage of inducing process, 23.2±3.5 neurospheres per plate formed in astrocyte-induced group and only 0.8±0.3 per plate in the control group (clonogenic assay, P<0.01), and the ratio of nestin positive cells was (50.2±2.8)% in astrocyte-induced group and only (1.4±0.5)% in the control group (flow cytometry, P<0.01). With the induction undergoing, the expression of Oct-4 gradually decreased and then disappeared, while the expression of nestin was increased step by step, and the ratio of nestin positive cells was up to 91.4% by the three-stage differentiation. The nestin positive cells could be further induced into

  1. Lauric Acid Stimulates Ketone Body Production in the KT-5 Astrocyte Cell Line.

    Science.gov (United States)

    Nonaka, Yudai; Takagi, Tetsuo; Inai, Makoto; Nishimura, Shuhei; Urashima, Shogo; Honda, Kazumitsu; Aoyama, Toshiaki; Terada, Shin

    2016-08-01

    Coconut oil has recently attracted considerable attention as a potential Alzheimer's disease therapy because it contains large amounts of medium-chain fatty acids (MCFAs) and its consumption is thought to stimulate hepatic ketogenesis, supplying an alternative energy source for brains with impaired glucose metabolism. In this study, we first reevaluated the responses of plasma ketone bodies to oral administration of coconut oil to rats. We found that the coconut oil-induced increase in plasma ketone body concentration was negligible and did not significantly differ from that observed after high-oleic sunflower oil administration. In contrast, the administration of coconut oil substantially increased the plasma free fatty acid concentration and lauric acid content, which is the major MCFA in coconut oil. Next, to elucidate whether lauric acid can activate ketogenesis in astrocytes with the capacity to generate ketone bodies from fatty acids, we treated the KT-5 astrocyte cell line with 50 and 100 μM lauric acid for 4 h. The lauric acid treatments increased the total ketone body concentration in the cell culture supernatant to a greater extent than oleic acid, suggesting that lauric acid can directly and potently activate ketogenesis in KT-5 astrocytes. These results suggest that coconut oil intake may improve brain health by directly activating ketogenesis in astrocytes and thereby by providing fuel to neighboring neurons.

  2. Generation of GFAP::GFP astrocyte reporter lines from human adult fibroblast-derived iPS cells using zinc-finger nuclease technology.

    Science.gov (United States)

    Zhang, Ping-Wu; Haidet-Phillips, Amanda M; Pham, Jacqueline T; Lee, Youngjin; Huo, Yuqing; Tienari, Pentti J; Maragakis, Nicholas J; Sattler, Rita; Rothstein, Jeffrey D

    2016-01-01

    Astrocytes are instrumental to major brain functions, including metabolic support, extracellular ion regulation, the shaping of excitatory signaling events and maintenance of synaptic glutamate homeostasis. Astrocyte dysfunction contributes to numerous developmental, psychiatric and neurodegenerative disorders. The generation of adult human fibroblast-derived induced pluripotent stem cells (iPSCs) has provided novel opportunities to study mechanisms of astrocyte dysfunction in human-derived cells. To overcome the difficulties of cell type heterogeneity during the differentiation process from iPSCs to astroglial cells (iPS astrocytes), we generated homogenous populations of iPS astrocytes using zinc-finger nuclease (ZFN) technology. Enhanced green fluorescent protein (eGFP) driven by the astrocyte-specific glial fibrillary acidic protein (GFAP) promoter was inserted into the safe harbor adeno-associated virus integration site 1 (AAVS1) locus in disease and control-derived iPSCs. Astrocyte populations were enriched using Fluorescence Activated Cell Sorting (FACS) and after enrichment more than 99% of iPS astrocytes expressed mature astrocyte markers including GFAP, S100β, NFIA and ALDH1L1. In addition, mature pure GFP-iPS astrocytes exhibited a well-described functional astrocytic activity in vitro characterized by neuron-dependent regulation of glutamate transporters to regulate extracellular glutamate concentrations. Engraftment of GFP-iPS astrocytes into rat spinal cord grey matter confirmed in vivo cell survival and continued astrocytic maturation. In conclusion, the generation of GFAP::GFP-iPS astrocytes provides a powerful in vitro and in vivo tool for studying astrocyte biology and astrocyte-driven disease pathogenesis and therapy.

  3. Gene expression profiling of human neural progenitor cells following the serum-induced astrocyte differentiation.

    Science.gov (United States)

    Obayashi, Shinya; Tabunoki, Hiroko; Kim, Seung U; Satoh, Jun-ichi

    2009-05-01

    Neural stem cells (NSC) with self-renewal and multipotent properties could provide an ideal cell source for transplantation to treat spinal cord injury, stroke, and neurodegenerative diseases. However, the majority of transplanted NSC and neural progenitor cells (NPC) differentiate into astrocytes in vivo under pathological environments in the central nervous system, which potentially cause reactive gliosis. Because the serum is a potent inducer of astrocyte differentiation of rodent NPC in culture, we studied the effect of the serum on gene expression profile of cultured human NPC to identify the gene signature of astrocyte differentiation of human NPC. Human NPC spheres maintained in the serum-free culture medium were exposed to 10% fetal bovine serum (FBS) for 72 h, and processed for analyzing on a Whole Human Genome Microarray of 41,000 genes, and the microarray data were validated by real-time RT-PCR. The serum elevated the levels of expression of 45 genes, including ID1, ID2, ID3, CTGF, TGFA, METRN, GFAP, CRYAB and CSPG3, whereas it reduced the expression of 23 genes, such as DLL1, DLL3, PDGFRA, SOX4, CSPG4, GAS1 and HES5. Thus, the serum-induced astrocyte differentiation of human NPC is characterized by a counteraction of ID family genes on Delta family genes. Coimmunoprecipitation analysis identified ID1 as a direct binding partner of a proneural basic helix-loop-helix (bHLH) transcription factor MASH1. Luciferase assay indicated that activation of the DLL1 promoter by MASH1 was counteracted by ID1. Bone morphogenetic protein 4 (BMP4) elevated the levels of ID1 and GFAP expression in NPC under the serum-free culture conditions. Because the serum contains BMP4, these results suggest that the serum factor(s), most probably BMP4, induces astrocyte differentiation by upregulating the expression of ID family genes that repress the proneural bHLH protein-mediated Delta expression in human NPC.

  4. Ceramide in primary astrocytes from cerebellum: metabolism and role in cell proliferation.

    Science.gov (United States)

    Riboni, Laura; Tettamanti, Guido; Viani, Paola

    2002-04-01

    Cerebellar astrocytes are equipped with an efficient molecular machinery able to control the levels, and possibly the subcellular location, of ceramide. The major metabolic routes that contribute to the maintenance and variation of the cellular ceramide include ceramide biosynthesis, by de novo pathway or sphingosine recycling, ceramide formation from complex sphingolipids degradation and ceramide catabolism. In cerebellar astrocytes from rat cerebellum a peculiar metabolism of sphingomyelin occurs. This includes the preponderance of acidic sphingomyelinase, paralleled by a deficiency of the neutral Mg2+-dependent enzyme, as well as the presence of an extra-Golgi form of sphingomyelin synthase, which shares many characteristics with PC-PLC. Moreover these cells are characterized by a high efficiency in converting sphingosine to ceramide, possibly functional to the role played by astrocytes in the prevention of neuronal damage by high sphingosine concentration. Recent evidence demonstrates that a change of ceramide level is one of the key steps in the chain of reactions elicited by mitogenic stimuli. In fact, low cellular levels of ceramide characterize, and appear to be required for, the proliferation of cerebellar astrocytes. In particular mitogenic stimuli, such as basic fibroblast growth factor (bFGF), rapidly down regulate the cellular levels of ceramide by stimulating sphingomyelin synthase. Ceramide acts as an intracellular physiological inhibitor of cell growth, being able to counteract the effect of bFGF by inhibiting the MAP kinase pathway. Although many questions remain in this field, the present knowledge strongly supports that ceramide represents a crucial member within lipid mediators, involved in the signaling pathways underlying cell proliferation in cerebellar astrocytes.

  5. Hippocalcin Is Required for Astrocytic Differentiation through Activation of Stat3 in Hippocampal Neural Precursor Cells.

    Directory of Open Access Journals (Sweden)

    Min-Jeong Kang

    2016-10-01

    Full Text Available Hippocalcin (Hpca is a neuronal calcium sensor protein expressed in the mammalian brain. However, its function in neural stem/precursor cells has not yet been studied. Here, we clarify the function of Hpca in astrocytic differentiation in hippocampal neural precursor cells (HNPCs. When we overexpressed Hpca in HNPCs in the presence or absence of bFGF, expression levels of nerve-growth factors such as neurotrophin-3 (NT-3, neurotrophin-4/5 (NT-4/5 and brain-derived neurotrophic factor (BDNF, together with the proneural basic helix loop helix (bHLH transcription factors neuroD and neurogenin 1 (ngn1, increased significantly. In addition, there was an increase in the number of cells expressing glial fibrillary acidic protein (GFAP, an astrocyte marker, and in dendrite outgrowth, indicating astrocytic differentiation of the HNPCs. Downregulation of Hpca by transfection with Hpca siRNA reduced expression of NT-3, NT-4/5, BDNF, neuroD and ngn1 as well as levels of GFAP protein. Furthermore, overexpression of Hpca increased the phosphorylation of STAT3 (Ser727, and this effect was abolished by treatment with a STAT3 inhibitor (S3I-201, suggesting that STAT3 (Ser727 activation is involved in Hpca-mediated astrocytic differentiation. As expected, treatment with Stat3 siRNA or STAT3 inhibitor caused a complete inhibition of astrogliogenesis induced by Hpca overexpression. Taken together, this is the first report to show that Hpca, acting through Stat3, has an important role in the expression of neurotrophins and proneural bHLH transcription factors, and that it is an essential regulator of astrocytic differentiation and dendrite outgrowth in HNPCs.

  6. Oligodendroglioma cells shed microvesicles which contain TRAIL as well as molecular chaperones and induce cell death in astrocytes.

    Science.gov (United States)

    Lo Cicero, Alessandra; Schiera, Gabriella; Proia, Patrizia; Saladino, Patrizia; Savettieri, Giovanni; Di Liegro, Carlo Maria; Di Liegro, Italia

    2011-12-01

    Microvesicles (MVs) shed from G26/24 oligodendroglioma cells were previously reported to cause a reproducible, dose-dependent, inhibitory effect on neurite outgrowth, and eventually neuronal apoptosis, when added to primary cultures of rat cortical neurons. These effects were reduced but not abolished by functional monoclonal antibodies against Fas-L. In order to investigate whether MVs contain other factors able to induce cell death, we tested them for TRAIL and found clear evidence of its presence in the vesicles. This finding suggests the possibility that Fas-L and TRAIL cooperate in inducing brain cell death. Aimed at understanding the route through which the vesicles deliver their messages to the target cells, we labeled oligodendroglioma cells with radioactive methionine and then added the labeled vesicles shed from tumor cells to unlabeled astrocytes in culture. Here we report that labeled proteins were delivered to the test cells. In order to investigate whether astrocytes, like neurons, are sensitive to oligodendroglioma-derived vesicles, MVs were prepared from media conditioned by G26/24 oligodendroglioma cells and added to primary cultures of rat cortical astrocytes. These cells were clearly more resistant than neurons to microvesicle-induced damage: a high dose (40 µg) of shed MVs induced cell death in only about 40% of astrocytes. Finally, we demonstrated that Hsp70 is specifically enriched in MVs which also contain, even if at lower level, the Hsc70 constitutive chaperone.

  7. Testosterone Protects Mitochondrial Function and Regulates Neuroglobin Expression in Astrocytic Cells Exposed to Glucose Deprivation

    OpenAIRE

    Toro-Urrego, Nicolas; Garcia-Segura, Luis M.; Echeverria, Valentina; Barreto, George E.

    2016-01-01

    Testosterone is a hormone that has been shown to confer neuroprotection from different insults affecting the central nervous system (CNS). Testosterone induces this protection by different mechanisms that include the activation of anti-apoptotic pathways that are directly implicated in neuronal survival. However, little attention has been devoted to its actions on glial cells. In the present study, we have assessed whether testosterone exerts protection in a human astrocyte cell model, the T9...

  8. Human iPS cell-derived astrocyte transplants preserve respiratory function after spinal cord injury.

    Science.gov (United States)

    Li, Ke; Javed, Elham; Scura, Daniel; Hala, Tamara J; Seetharam, Suneil; Falnikar, Aditi; Richard, Jean-Philippe; Chorath, Ashley; Maragakis, Nicholas J; Wright, Megan C; Lepore, Angelo C

    2015-09-01

    Transplantation-based replacement of lost and/or dysfunctional astrocytes is a promising therapy for spinal cord injury (SCI) that has not been extensively explored, despite the integral roles played by astrocytes in the central nervous system (CNS). Induced pluripotent stem (iPS) cells are a clinically-relevant source of pluripotent cells that both avoid ethical issues of embryonic stem cells and allow for homogeneous derivation of mature cell types in large quantities, potentially in an autologous fashion. Despite their promise, the iPS cell field is in its infancy with respect to evaluating in vivo graft integration and therapeutic efficacy in SCI models. Astrocytes express the major glutamate transporter, GLT1, which is responsible for the vast majority of glutamate uptake in spinal cord. Following SCI, compromised GLT1 expression/function can increase susceptibility to excitotoxicity. We therefore evaluated intraspinal transplantation of human iPS cell-derived astrocytes (hIPSAs) following cervical contusion SCI as a novel strategy for reconstituting GLT1 expression and for protecting diaphragmatic respiratory neural circuitry. Transplant-derived cells showed robust long-term survival post-injection and efficiently differentiated into astrocytes in injured spinal cord of both immunesuppressed mice and rats. However, the majority of transplant-derived astrocytes did not express high levels of GLT1, particularly at early times post-injection. To enhance their ability to modulate extracellular glutamate levels, we engineered hIPSAs with lentivirus to constitutively express GLT1. Overexpression significantly increased GLT1 protein and functional GLT1-mediated glutamate uptake levels in hIPSAs both in vitro and in vivo post-transplantation. Compared to human fibroblast control and unmodified hIPSA transplantation, GLT1-overexpressing hIPSAs reduced (1) lesion size within the injured cervical spinal cord, (2) morphological denervation by respiratory phrenic motor

  9. Extracellular Microvesicles from Astrocytes Contain Functional Glutamate Transporters: Regulation by Protein Kinase C and Cell Activation

    Directory of Open Access Journals (Sweden)

    Romain-Daniel eGosselin

    2013-12-01

    Full Text Available Glutamate transport through astrocytic excitatory amino-acid transporters (EAAT-1 and EAAT-2 is paramount for neural homeostasis. EAAT-1 has been reported in secreted extracellular microvesicles (eMV, such as exosomes and because the Protein Kinase C (PKC family controls the sub-cellular distribution of EAATs, we have explored whether PKCs drive EAATs into eMV. Using rat primary astrocytes, confocal immunofluorescence and ultracentrifugation on sucrose gradient we here report that PKC activation by phorbol myristate acetate (PMA reorganizes EAAT-1 distribution and reduces functional [3H]-aspartate reuptake. Western-blots show that EAAT-1 is present in eMV from astrocyte conditioned medium, together with NaK ATPase and glutamine synthetase all being further increased after PMA treatment. However, nanoparticle tracking analysis reveals that PKC activation did not change particle concentration. Functional analysis indicates that eMV have the capacity to reuptake [3H]-aspartate. In vivo, we demonstrate that spinal astrocytic reaction induced by peripheral nerve lesion (spared nerve injury, SNI is associated with a phosphorylation of PKC δ together with a shift of EAAT distribution ipsilaterally. Ex vivo, spinal explants from SNI rats release eMV with an increased content of NaK ATPase, EAAT-1 and EAAT-2. These data indicate PKC and cell activation as important regulators of EAAT-1 incorporation in eMV, and raise the possibility that microvesicular EAAT-1 may exert extracellular functions. Beyond a putative role in neuropathic pain, this phenomenon may be important for understanding neural homeostasis and a wide range of neurological diseases associated with astrocytic reaction as well as non-neurological diseases linked to eMV release.

  10. Effect of down-regulation of voltage-gated sodium channel Nav1.7 on activation of astrocytes and microglia in DRG in rats with cancer pain

    Institute of Scientific and Technical Information of China (English)

    Jun Pan; Xiang-Jin Lin; Zhi-Heng Ling; You-Zhi Cai

    2015-01-01

    Objective:To evaluate the effect of down-regulation of Nav1.7 on the activation of astrocytes and microglia in DRG of rats with cancer pain, and explore the transmission of the nociceptive information.Methods:Lentiviral vector harboring RNAi sequence targeting theNav1.7gene was constructed, and Walker 256 breast cancer cell and morphine was injected to build the bone cancer pain model and morphine tolerance model in rats. Lentiviral vector was injected. Rats in each model were divided into 4 groups: model group, PBS group, vehicle group and LV-Nav1.7 group. The expression levels of GFAP and OX42 in dorsal root ganglia (DRG) were measured.Results: After the animal model was built,the level of Nav1.7, GFAP and OX42 was improved obviously with the time prolonged, which was statistically significant (P<0.05). The expression level of GFAP and OX42 in the DRG in the LV-Nav1.7 group declined obviously compared to the model group, PBS group and vehicle group (P<0.05).Conclusions:Intrathecal injection of Navl.7 shRNA lentiviral vector can reduce the expression of Nav1.7 and inhibit the activation of astrocytes and microglia in DRG. The effort is also effective in morphine tolerance bone cancer pain model rats.

  11. Endothelial Cells and Astrocytes: A Concerto en Duo in Ischemic Pathophysiology

    Directory of Open Access Journals (Sweden)

    Vincent Berezowski

    2012-01-01

    Full Text Available The neurovascular/gliovascular unit has recently gained increased attention in cerebral ischemic research, especially regarding the cellular and molecular changes that occur in astrocytes and endothelial cells. In this paper we summarize the recent knowledge of these changes in association with edema formation, interactions with the basal lamina, and blood-brain barrier dysfunctions. We also review the involvement of astrocytes and endothelial cells with recombinant tissue plasminogen activator, which is the only FDA-approved thrombolytic drug after stroke. However, it has a narrow therapeutic time window and serious clinical side effects. Lastly, we provide alternative therapeutic targets for future ischemia drug developments such as peroxisome proliferator- activated receptors and inhibitors of the c-Jun N-terminal kinase pathway. Targeting the neurovascular unit to protect the blood-brain barrier instead of a classical neuron-centric approach in the development of neuroprotective drugs may result in improved clinical outcomes after stroke.

  12. Intervention timing and effect of PJ34 on astrocytes during oxygen-glucose deprivation/reperfusion and cell death pathways.

    Science.gov (United States)

    Cai, Chuan; Zhang, Rui; Huang, Qiao-Ying; Cao, Xu; Zou, Liang-Yu; Chu, Xiao-Fan

    2015-06-01

    Poly (ADP-ribose) polymerase-1 (PARP-1) plays as a double edged sword in cerebral ischemia-reperfusion, hinging on its effect on the intracellular energy storage and injury severity, and the prognosis has relationship with intervention timing. During ischemia injury, apoptosis and oncosis are the two main cell death pathway sin the ischemic core. The participation of astrocytes in ischemia-reperfusion induced cell death has triggered more and more attention. Here, we examined the protective effects and intervention timing of the PARP-1 inhibitor PJ34, by using a mixed oxygen-glucose deprivation/reperfusion (OGDR) model of primary rat astrocytes in vitro, which could mimic the ischemia-reperfusion damage in the "ischemic core". Meanwhile, cell death pathways of various PJ34 treated astrocytes were also investigated. Our results showed that PJ34 incubation (10 μmol/L) did not affect release of lactate dehydrogenase (LDH) from astrocytes and cell viability or survival 1 h after OGDR. Interestingly, after 3 or 5 h OGDR, PJ34 significantly reduced LDH release and percentage of PI-positive cells and increased cell viability, and simultaneously increased the caspase-dependent apoptotic rate. The intervention timing study demonstrated that an earlier and longer PJ34 intervention during reperfusion was associated with more apparent protective effects. In conclusion, earlier and longer PJ34 intervention provides remarkable protective effects for astrocytes in the "ischaemic core" mainly by reducing oncosis of the astrocytes, especially following serious OGDR damage.

  13. Exposure to cell phone radiation up-regulates apoptosis genes in primary cultures of neurons and astrocytes.

    Science.gov (United States)

    Zhao, Tian-Yong; Zou, Shi-Ping; Knapp, Pamela E

    2007-01-22

    The health effects of cell phone radiation exposure are a growing public concern. This study investigated whether expression of genes related to cell death pathways are dysregulated in primary cultured neurons and astrocytes by exposure to a working Global System for Mobile Communication (GSM) cell phone rated at a frequency of 1900MHz. Primary cultures were exposed to cell phone emissions for 2h. We used array analysis and real-time RT-PCR to show up-regulation of caspase-2, caspase-6 and Asc (apoptosis associated speck-like protein containing a card) gene expression in neurons and astrocytes. Up-regulation occurred in both "on" and "stand-by" modes in neurons, but only in "on" mode in astrocytes. Additionally, astrocytes showed up-regulation of the Bax gene. The effects are specific since up-regulation was not seen for other genes associated with apoptosis, such as caspase-9 in either neurons or astrocytes, or Bax in neurons. The results show that even relatively short-term exposure to cell phone radiofrequency emissions can up-regulate elements of apoptotic pathways in cells derived from the brain, and that neurons appear to be more sensitive to this effect than astrocytes.

  14. Preclinical Studies of Induced Pluripotent Stem Cell-Derived Astrocyte Transplantation in ALS

    Science.gov (United States)

    2013-10-01

    to neuralize the cultures. This was considered day 1 of differentiation. At day 3, retinoic acid (RA, 1 μM, Sigma-Aldrich) and ascorbic acid (0.4...whether these iPSC-derived cells may in fact harbor ALS-specific abnormalities that may lack benefit or, potentially exacerbate disease. By comparing...mature properties in vivo which may be essential for their potential therapeutic benefits in patients. In evaluation of the hiPSC-derived astrocyte

  15. Generation of reactive astrocytes from NG2 cells is regulated by sonic hedgehog.

    Science.gov (United States)

    Honsa, Pavel; Valny, Martin; Kriska, Jan; Matuskova, Hana; Harantova, Lenka; Kirdajova, Denisa; Valihrach, Lukas; Androvic, Peter; Kubista, Mikael; Anderova, Miroslava

    2016-09-01

    NG2 cells, a fourth glial cell type in the adult mammalian central nervous system, produce oligodendrocytes in the healthy nervous tissue, and display wide differentiation potential under pathological conditions, where they could give rise to reactive astrocytes. The factors that control the differentiation of NG2 cells after focal cerebral ischemia (FCI) are largely unknown. Here, we used transgenic Cspg4-cre/Esr1/ROSA26Sortm14(CAG-tdTomato) mice, in which tamoxifen administration triggers the expression of red fluorescent protein (tomato) specifically in NG2 cells and cells derived therefrom. Differentiation potential (in vitro and in vivo) of tomato-positive NG2 cells from control or postischemic brains was determined using the immunohistochemistry, single cell RT-qPCR and patch-clamp method. The ischemic injury was induced by middle cerebral artery occlusion, a model of FCI. Using genetic fate-mapping method, we identified sonic hedgehog (Shh) as an important factor that influences differentiation of NG2 cells into astrocytes in vitro. We also manipulated Shh signaling in the adult mouse brain after FCI. Shh signaling activation significantly increased the number of astrocytes derived from NG2 cells in the glial scar around the ischemic lesion, while Shh signaling inhibition caused the opposite effect. Since Shh signaling modifications did not change the proliferation rate of NG2 cells, we can conclude that Shh has a direct influence on the differentiation of NG2 cells and therefore, on the formation and composition of a glial scar, which consequently affects the degree of the brain damage. GLIA 2016;64:1518-1531.

  16. Activated astrocytes enhance the dopaminergic differentiation of stem cells and promote brain repair through bFGF.

    Science.gov (United States)

    Yang, Fan; Liu, Yunhui; Tu, Jie; Wan, Jun; Zhang, Jie; Wu, Bifeng; Chen, Shanping; Zhou, Jiawei; Mu, Yangling; Wang, Liping

    2014-12-17

    Astrocytes provide neuroprotective effects against degeneration of dopaminergic (DA) neurons and play a fundamental role in DA differentiation of neural stem cells. Here we show that light illumination of astrocytes expressing engineered channelrhodopsin variant (ChETA) can remarkably enhance the release of basic fibroblast growth factor (bFGF) and significantly promote the DA differentiation of human embryonic stem cells (hESCs) in vitro. Light activation of transplanted astrocytes in the substantia nigra (SN) also upregulates bFGF levels in vivo and promotes the regenerative effects of co-transplanted stem cells. Importantly, upregulation of bFGF levels, by specific light activation of endogenous astrocytes in the SN, enhances the DA differentiation of transplanted stem cells and promotes brain repair in a mouse model of Parkinson's disease (PD). Our study indicates that astrocyte-derived bFGF is required for regulation of DA differentiation of the stem cells and may provide a strategy targeting astrocytes for treatment of PD.

  17. Astrocyte pathology in a human neural stem cell model of frontotemporal dementia caused by mutant TAU protein

    Science.gov (United States)

    Hallmann, Anna-Lena; Araúzo-Bravo, Marcos J.; Mavrommatis, Lampros; Ehrlich, Marc; Röpke, Albrecht; Brockhaus, Johannes; Missler, Markus; Sterneckert, Jared; Schöler, Hans R.; Kuhlmann, Tanja; Zaehres, Holm; Hargus, Gunnar

    2017-01-01

    Astroglial pathology is seen in various neurodegenerative diseases including frontotemporal dementia (FTD), which can be caused by mutations in the gene encoding the microtubule-associated protein TAU (MAPT). Here, we applied a stem cell model of FTD to examine if FTD astrocytes carry an intrinsic propensity to degeneration and to determine if they can induce non-cell-autonomous effects in neighboring neurons. We utilized CRISPR/Cas9 genome editing in human induced pluripotent stem (iPS) cell-derived neural progenitor cells (NPCs) to repair the FTD-associated N279K MAPT mutation. While astrocytic differentiation was not impaired in FTD NPCs derived from one patient carrying the N279K MAPT mutation, FTD astrocytes appeared larger, expressed increased levels of 4R-TAU isoforms, demonstrated increased vulnerability to oxidative stress and elevated protein ubiquitination and exhibited disease-associated changes in transcriptome profiles when compared to astrocytes derived from one control individual and to the isogenic control. Interestingly, co-culture experiments with FTD astrocytes revealed increased oxidative stress and robust changes in whole genome expression in previously healthy neurons. Our study highlights the utility of iPS cell-derived NPCs to elucidate the role of astrocytes in the pathogenesis of FTD. PMID:28256506

  18. QKI-7 regulates expression of interferon-related genes in human astrocyte glioma cells.

    Directory of Open Access Journals (Sweden)

    Lin Jiang

    Full Text Available BACKGROUND: The human QKI gene, called quaking homolog, KH domain RNA binding (mouse, is a candidate gene for schizophrenia encoding an RNA-binding protein. This gene was shown to be essential for myelination in oligodendrocytes. QKI is also highly expressed in astrocytes, but its function in these cells is not known. METHODS/PRINCIPAL FINDINGS: We studied the effect of small interference RNA (siRNA-mediated QKI depletion on global gene expression in human astrocyte glioma cells. Microarray measurements were confirmed with real-time quantitative polymerase chain reaction (qPCR. The presence of QKI binding sites (QRE was assessed by a bioinformatic approach. Viability and cell morphology were also studied. The most significant alteration after QKI silencing was the decreased expression of genes involved in interferon (IFN induction (P = 6.3E-10, including IFIT1, IFIT2, MX1, MX2, G1P2, G1P3, GBP1 and IFIH1. All eight genes were down-regulated after silencing of the splice variant QKI-7, but were not affected by QKI-5 silencing. Interestingly, four of them were up-regulated after treatment with the antipsychotic agent haloperidol that also resulted in increased QKI-7 mRNA levels. CONCLUSIONS/SIGNIFICANCE: The coordinated expression of QKI-7 splice variant and IFN-related genes supports the idea that this particular splice variant has specific functions in astrocytes. Furthermore, a role of QKI-7 as a regulator of an inflammatory gene pathway in astrocytes is suggested. This hypothesis is well in line with growing experimental evidence on the role of inflammatory components in schizophrenia.

  19. The development of blood-retinal barrier during the interaction of astrocytes with vascular wall cells

    Institute of Scientific and Technical Information of China (English)

    Huanling Yao; Tianshi Wang; Jiexin Deng; Ding Liu; Xiaofei Li; Jinbo Deng

    2014-01-01

    Astrocytes are intimately involved in the formation and development of retinal vessels. Astrocyte dysfunction is a major cause of blood-retinal barrier injury and other retinal vascular diseases. In this study, the development of the retinal vascular system and the formation of the blood-ret-inal barrier in mice were investigated using immunolfuorescence staining, gelatin-ink perfusion, and transmission electron microscopy. The results showed that the retinal vascular system of mice develops from the optic disc after birth, and radiates out gradually to cover the entire retina, taking the papilla optica as the center. First, the superifcial vasculature is formed on the inner retinal layer;then, the vasculature extends into the inner and outer edges of the retinal inner nuclear layer, forming the deep vasculature that is parallel to the superifcial vasculature. The blood-retinal barrier is mainly composed of endothelium, basal lamina and the end-feet of astrocytes, which become mature during mouse development. Initially, the naive endothelial cells were immature with few organelles and many microvilli. The basal lamina was uniform in thickness, and the glial end-feet surrounded the outer basal lamina incompletely. In the end, the blood-retinal barrier matures with smooth endothelia connected through tight junctions, rela-tively thin and even basal lamina, and relatively thin glial cell end-feet. These ifndings indicate that the development of the vasculature in the retina follows the rules of“center to periphery”and“superifcial layer to deep layers”. Its development and maturation are spatially and tempo-rally consistent with the functional performance of retinal neurons and photosensitivity. The blood-retinal barrier gradually becomes mature via the process of interactions between astro-cytes and blood vessel cells.

  20. Ischemic brain cell-derived conditioned medium protects astrocytes against ischemia through GDNF/ERK/NF-kB signaling pathway.

    Science.gov (United States)

    Chu, Lan-Feng; Wang, Wei-Ti; Ghanta, Vithal K; Lin, Chi-Hsin; Chiang, Yung-Yen; Hsueh, Chi-Mei

    2008-11-06

    Conditioned medium (CM) collected from cultures of ischemic microglia, astrocytes, and neurons were protective to astrocytes under the in vitro ischemic condition (deprivation of oxygen, glucose and serum). Molecular and signaling pathway(s) responsible for the CMs protective activity were investigated. Results showed that CMs from the ischemic microglia (MCM), astrocytes (ACM) and neurons (NCM) contained glial cell line-derived neurotrophic factor (GDNF), which protects astrocytes against the in vitro ischemia. Expression of extra cellular signal-regulated kinase (ERK1/2) and nuclear factor-kappa B (NF-kB) by GDNF led to the inhibition of apoptosis of the ischemic astrocytes in a caspase 3-independent manner. However, CMs- and GDNF-mediated protection of the ischemic astrocytes was protein kinase B (Akt) independent. These results provided mechanistic data regarding how GDNF- and CMs-mediated protection of the ischemic astrocytes is taking place. These observations provide information for the use of GDNF and GDNF containing CMs in the control of cerebral ischemia.

  1. Cell-type-specific and differentiation-status-dependent variations in cytotoxicity of tributyltin in cultured rat cerebral neurons and astrocytes.

    Science.gov (United States)

    Oyanagi, Koshi; Tashiro, Tomoko; Negishi, Takayuki

    2015-08-01

    Tributyltin (TBT) is an organotin used as an anti-fouling agent for fishing nets and ships and it is a widespread environmental contaminant at present. There is an increasing concern about imperceptible but serious adverse effect(s) of exposure to chemicals existing in the environment on various organs and their physiological functions, e.g. brain and mental function. Here, so as to contribute to improvement of and/or advances in in vitro cell-based assay systems for evaluating brain-targeted adverse effect of chemicals, we tried to evaluate cell-type-specific and differentiation-status-dependent variations in the cytotoxicity of TBT towards neurons and astrocytes using the four culture systems differing in the relative abundance of these two types of cells; primary neuron culture (> 95% neurons), primary neuron-astrocyte (2 : 1) mix culture, primary astrocyte culture (> 95% astrocytes), and passaged astrocyte culture (100% proliferative astrocytes). Cell viability was measured at 48 hr after exposure to TBT in serum-free medium. IC50's of TBT were 198 nM in primary neuron culture, 288 nM in primary neuron-astrocyte mix culture, 2001 nM in primary astrocyte culture, and 1989 nM in passaged astrocyte culture. Furthermore, in primary neuron-astrocyte mix culture, vulnerability of neurons cultured along with astrocytes to TBT toxicity was lower than that of neurons cultured purely in primary neuron culture. On the other hand, astrocytes in primary neuron-astrocyte mix culture were considered to be more vulnerable to TBT than those in primary or passaged astrocyte culture. The present study demonstrated variable cytotoxicity of TBT in neural cells depending on the culture condition.

  2. Effect of diclofenac and antidepressants on the inflammatory response in astrocyte cell culture.

    Science.gov (United States)

    Al-Amin, Md Mamun; Uddin, Mir Muhammad Nasir; Rahman, Md Mahbubur; Reza, Hasan Mahmud; Rana, Md Sohel

    2013-12-01

    Central nervous system (CNS) has a completely separate immune system that communicates with the neurons by small molecules called cytokines. Cytokines are involved in many crucial processes in neuron including cell metabolism and neurotransmitter synthesis. It has been reported that cytokine imbalance is involved in the progression of many CNS diseases such as neuropsychiatric disorders (depression, schizophrenia, autism, and bipolar disorder) and neurodegenerative disorders (Parkinson's and Alzheimer's disease). Here, the effects of diclofenac, different antidepressants (sertraline, venlafaxine, and fluvoxamine), and vitamin B₆ (pyridoxine) on IL-10 and tumor necrosis factor-α (TNF-α) change with and without immune challenges with lipopolysaccharide (LPS) were investigated in in vitro culture of astrocytes from 2-day-old Swiss-Albino mice. Diclofenac and Sertraline significantly (p 0.05) TNF-α in the astrocyte culture. Antidepressant (sertraline) showed positive effects (increased IL-10 and reduced TNF-α level) possibly through the suppression of Th1 lymphocytes and monocytes and stimulation of Th2 lymphocytes and monocytes/macrophages. NSAID (diclofenac) showed positive immune regulation effect possibly through the inhibition of cyclo-oxygenase enzyme. Based on these findings, it may conclude that, diclofenac and antidepressants (sertraline) may positively contribute in the cytokine production in astrocyte cell culture.

  3. Lung cancer - small cell

    Science.gov (United States)

    Cancer - lung - small cell; Small cell lung cancer; SCLC ... About 15% of all lung cancer cases are SCLC. Small cell lung cancer is slightly more common in men than women. Almost all cases of SCLC are ...

  4. Hypoxic regulation of Ca2+ signalling in astrocytes and endothelial cells.

    Science.gov (United States)

    Peers, C; Kang, P; Boyle, J P; Porter, K E; Pearson, H A; Smith, I F; Kemp, P J

    2006-01-01

    Acute hypoxia is well known to modulate plasmalemmal ion channels in specific tissue types, thereby modulating [Ca2+]i. Alternative mechanisms by which acute hypoxia could modulate [Ca2+]i are less well explored, particularly in non-excitable cells. Here, we describe experiments employing microfluorimetric recordings from Fura-2-loaded rat cortical astrocytes and human saphenous vein endothelial cells designed to explore any effects of hypoxia (pO2 20-30 mmHg) on [Ca2+]i. In both cell types, hypoxia evoked small rises of [Ca2+]i in the majority of cells during perfusion with a Ca(2+)-free solution, indicating hypoxia can release Ca2+ from an intracellular pool. Capacitative Ca2+ entry was observed when Ca2+ was subsequently restored to the extracellular solution. These effects were abolished by pre-treatment of cells with thapsigargin or prior application of inositol 1,4,5-trisphosphate (IP3)-generating agonists. Antioxidants fully prevented this effect of hypoxia in both cell types. Mitochondrial uncoupling significantly enhanced the effects of hypoxia in astrocytes, yet markedly suppressed the effects of hypoxia in endothelial cells. Our findings indicate that hypoxia can modulate [Ca2+]i in non-excitable cells; most importantly, it can evoke Ca2+ release from intracellular stores via a mechanism which involves reactive oxygen species. The involvement of mitochondria in this effect appears to be tissue specific.

  5. The analgesic effect of rolipram is associated with the inhibition of the activation of the spinal astrocytic JNK/CCL2 pathway in bone cancer pain

    Science.gov (United States)

    Guo, Chi-Hua; Bai, Lu; Wu, Huang-Hui; Yang, Jing; Cai, Guo-Hong; Wang, Xin; Wu, Sheng-Xi; Ma, Wei

    2016-01-01

    Bone cancer pain (BCP) is one of the most difficult and intractable tasks for pain management, which is associated with spinal 'neuron-astrocytic' activation. The activation of the c-Jun N-terminal kinase (JNK)/chemokine (C-C motif) ligand (CCL2) signaling pathway has been reported to be critical for neuropathic pain. Rolipram (ROL), a selective phosphodiesterase 4 inhibitor, possesses potent anti-inflammatory and anti-nociceptive activities. The present study aimed to investigate whether the intrathecal administration of ROL has an analgesic effect on BCP in rats, and to assess whether the inhibition of spinal JNK/CCL2 pathway and astrocytic activation are involved in the analgesic effects of ROL. The analgesic effects of ROL were evaluated using the Von Frey and Hargreaves tests. Immunofluorescence staining was used to determine the number of c-Fos immunoreactive neurons, and the expression of spinal astrocytes and microglial activation on day 14 after tumor cell inoculation. Enzyme-linked immunosorbent assay (ELISA) was used to detect the expression of pro-inflammatory cytokines [interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α] and chemokines (CCL2), and western blot analysis was then used to examine the spinal phosphodiesterase 4 (PDE4), ionized calcium binding adapter molecule-1 (IBA-1) and JNK levels on day 14 after tumor cell inoculation. The results revealed that ROL exerted a short-term analgesic effect in a dose-dependent manner, and consecutive daily injections of ROL exerted continuous analgesic effects. In addition, spinal 'neuron-astrocytic' activation was suppressed and was associated with the downregulation of spinal IL-1β, IL-6 and TNF-α expression, and the inhibition of PDE4B and JNK levels in the spine was also observed. In addition, the level of CCL2 was decreased in the rats with BCP. The JNK inhibitor, SP600125, decreased CCL2 expression and attenuated pain behavior. Following co-treatment with ROL and SP600125, no significant

  6. Targeting astrocytes in major depression

    OpenAIRE

    2015-01-01

    Astrocytes represent a highly heterogeneous population of neural cells primarily responsible for the homeostasis of the central nervous system. Astrocytes express multiple receptors for neurotransmitters, including the serotonin 5-HT2B receptors and interact with neurones at the synapse. Astroglia contribute to neurological diseases through homeostatic response, neuroprotection and reactivity. In major depression, astrocytes show signs of degeneration and are decreased in numbe...

  7. Immune Privilege as an Intrinsic CNS Property: Astrocytes Protect the CNS against T-Cell-Mediated Neuroinflammation

    Directory of Open Access Journals (Sweden)

    Ulrike Gimsa

    2013-01-01

    Full Text Available Astrocytes have many functions in the central nervous system (CNS. They support differentiation and homeostasis of neurons and influence synaptic activity. They are responsible for formation of the blood-brain barrier (BBB and make up the glia limitans. Here, we review their contribution to neuroimmune interactions and in particular to those induced by the invasion of activated T cells. We discuss the mechanisms by which astrocytes regulate pro- and anti-inflammatory aspects of T-cell responses within the CNS. Depending on the microenvironment, they may become potent antigen-presenting cells for T cells and they may contribute to inflammatory processes. They are also able to abrogate or reprogram T-cell responses by inducing apoptosis or secreting inhibitory mediators. We consider apparently contradictory functions of astrocytes in health and disease, particularly in their interaction with lymphocytes, which may either aggravate or suppress neuroinflammation.

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

    Directory of Open Access Journals (Sweden)

    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.

  9. Group B Streptococcus interactions with human meningeal cells and astrocytes in vitro.

    Directory of Open Access Journals (Sweden)

    Khalil Alkuwaity

    Full Text Available BACKGROUND: Streptococcus agalactiae (Group B Streptococcus, GBS is a leading cause of life-threatening neonatal meningitis and survivors often suffer permanent neurological damage. How this organism interacts with the meninges and subsequently with astrocytes that constitute the underlying cortical glia limitans superficialis is not known. METHODOLOGY/PRINCIPAL FINDINGS: In this paper, we demonstrate dose-dependent adherence of GBS over time to human meningioma cells and fetal astrocytes in vitro, which was not influenced by expression of either β-haemolysin/cytolysin (β-h/c toxin, different capsule serotypes or by absence of capsule (p>0.05. Internalization of GBS by both cell types was, however, a slow and an infrequent event (only 0.02-0.4% of associated bacteria were internalised by 9 h. Expression of β-h/c toxin did not play a role in invasion (p>0.05, whereas capsule expression lead to a reduction (p<0.05 in the numbers of intracellular bacteria recovered. GBS strains induced cytotoxicity as demonstrated by the measurement of lactate dehydrogenase (LDH enzyme release by 9 h and by viable staining. Increasing levels of meningioma cell death correlated with bacterial growth and the phenotype of β-h/c toxin production, i.e. from weakly, to normo- to hyper-haemolytic. However, cytotoxicity was significantly greater (p<0.05 towards astrocytes, and infection with initial MOI≥0.003 induced 70-100% LDH release. By comparing wild-type (β-h/c(+ and mutant (ΔcylE β-h/c(- strains and β-h/c toxin extracts and by using the surfactant dipalmitoylphosphatidylcholine in cytotoxicity inhibition experiments, β-h/c toxin was demonstrated as principally responsible for cell death. CONCLUSIONS/SIGNIFICANCE: This study has described key events in the interactions of GBS with meningeal cells and astrocytes in vitro and a major virulence role for β-h/c toxin. Understanding the mechanisms involved will help to identify potential therapies for improving

  10. A hit and run approach to inducible direct reprogramming of astrocytes to neural stem cells

    Directory of Open Access Journals (Sweden)

    Maria ePoulou

    2016-04-01

    Full Text Available Temporal and spatial control of gene expression can be achieved using an inducible system as a fundamental tool for regulated transcription in basic, applied and eventually in clinical research. We describe a novel hit and run inducible direct reprogramming approach. In a single step, two days post-transfection, transiently transfected Sox2FLAG under the Leu3p-αIPM inducible control (iSox2 triggers the activation of endogenous Sox2, redirecting primary astrocytes into abundant distinct nestin-positive radial glia cells. This technique introduces a unique novel tool for safe, rapid and efficient reprogramming amendable to regenerative medicine.

  11. Generation of primary cultures of bovine brain endothelial cells and setup of cocultures with rat astrocytes

    DEFF Research Database (Denmark)

    Helms, Hans C; Brodin, Birger

    2014-01-01

    In vitro models of the blood-brain barrier are useful tools to study blood-brain barrier function as well as drug permeation from the systemic circulation to the brain parenchyma. However, a large number of the available in vitro models fail to reflect the tightness of the in vivo blood-brain...... barrier. The present protocol describes the setup of an in vitro coculture model based on primary cultures of endothelial cells from bovine brain microvessels and primary cultures of rat astrocytes. The model displays a high electrical tightness and expresses blood-brain barrier marker proteins....

  12. Acceleration of astrocytic differentiation in neural stem cells surviving X-irradiation.

    Science.gov (United States)

    Ozeki, Ayumi; Suzuki, Keiji; Suzuki, Masatoshi; Ozawa, Hiroki; Yamashita, Shunichi

    2012-03-28

    Neural stem cells (NSCs) are highly susceptible to DNA double-strand breaks; however, little is known about the effects of radiation in cells surviving radiation. Although the nestin-positive NSCs predominantly became glial fibrillary acidic protein (GFAP)-positive in differentiation-permissive medium, little or no cells were GFAP positive in proliferation-permissive medium. We found that more than half of the cells surviving X-rays became GFAP positive in proliferation-permissive medium. Moreover, localized irradiation stimulated differentiation of cells outside the irradiated area. These results indicate for the first time that ionizing radiation is able to stimulate astrocyte-specific differentiation of surviving NSCs, whose process is mediated both by the direct activation of nuclear factor-κB and by the indirect bystander effect induced by X-irradiation.

  13. GABA(A) Increases Calcium in Subventricular Zone Astrocyte-Like Cells Through L- and T-Type Voltage-Gated Calcium Channels

    DEFF Research Database (Denmark)

    Young, Stephanie Z; Platel, Jean-Claude; Nielsen, Jakob V;

    2010-01-01

    intracellular Ca(2+) dynamics in SVZ astrocytes. To monitor Ca(2+) activity selectively in astrocyte-like cells, we used two lines of transgenic mice expressing either GFP fused to a Gq-coupled receptor or DsRed under the human glial fibrillary acidic protein (hGFAP) promoter. GABA(A) receptor activation......-like cells to 75%, suggesting that the majority of SVZ astrocytes express functional VGCCs. SVZ astrocytes also displayed spontaneous Ca(2+) activity, the frequency of which was regulated by tonic GABA(A) receptor activation. These data support a role for ambient GABA in tonically regulating intracellular Ca...

  14. Phenotypic transition of microglia into astrocyte-like cells associated with disease onset in a model of inherited ALS

    Directory of Open Access Journals (Sweden)

    Emiliano eTrias

    2013-12-01

    Full Text Available Microglia and reactive astrocytes accumulate in the spinal cord of rats expressing the ALS-linked SOD1G93A mutation. We previously reported that the rapid progression of paralysis in ALS rats is associated with the appearance of proliferative astrocyte-like cells thatsurroundmotor neurons. These cells, designated as Aberrant Astrocytes (AbA cells because of their atypical astrocytic phenotype, exhibit high toxicity to motor neurons. However, the cellular origin of AbA cells remains unknown. Because AbA cells are labeled with the proliferation marker Ki67, we analyzed the phenotypic makers of proliferating glial cells that surround motor neurons by immunohistochemistry. The number of Ki67+AbA cells sharply increased in symptomatic rats, displaying large cell bodies with processes embracing motor neurons. Most were co-labeled with astrocytic marker GFAP concurrently with the microglial markers Iba1 and CD163. Cultures of spinal cord prepared from symptomatic SOD1G93A rats yielded large numbers of microglia expressing Iba1, CD11b and CD68. Cells sortedfor CD11b expression by flow cytometry transformed into AbA cells within two weeks. During these two weeks, the expression of microglial markers largely disappeared, while GFAP and S100β expression increased. The phenotypic transition to AbA cells was stimulated by forskolin. These findings provide evidence for a subpopulation of proliferating microglial cells in SOD1G93A rats that undergo a phenotypic transition into AbA cells after onset of paralysis that may promote the fulminant disease progression. These cells could be a therapeutic target for slowing paralysis progression in ALS.

  15. Microglia-derived interleukin-6 and leukaemia inhibitory factor promote astrocytic differentiation of neural stem/progenitor cells.

    Science.gov (United States)

    Nakanishi, Masaya; Niidome, Tetsuhiro; Matsuda, Satoru; Akaike, Akinori; Kihara, Takeshi; Sugimoto, Hachiro

    2007-02-01

    Neural stem/progenitor cells (NSPCs) proliferate and differentiate depending on their intrinsic properties and local environment. It has been recognized that astrocytes promote neurogenic differentiation of NSPCs, suggesting the importance of cell-cell interactions between glial cells and NSPCs. Recent studies have demonstrated that microglia, one type of glial cells, play an important role in neurogenesis. However, little is known about how activated microglia control the proliferation and differentiation of NSPCs. In this study, we investigated the possibility that microglia-derived soluble factors regulate the behaviour of NSPCs. To this end, NSPCs and microglial cultures were obtained from rat embryonic day 16 subventricular zone (SVZ) and rat postnatal 1 day cortex, respectively, and the conditioned medium from microglia was prepared. Microglial-conditioned medium had no significant effect on the proliferation of NSPCs. In contrast, it increased the percentage of cells positive for a marker of astrocytes, glial fibrillary acidic protein (GFAP) during differentiation. The induction of astrocytic differentiation by microglial-conditioned medium was reduced by the inhibition of the Janus kinase/signal transducer and activation of transcription (JAK/STAT) and mitogen-activated protein kinase (MAPK) pathways. Furthermore, microglia-derived interleukin (IL)-6 and leukaemia inhibitory factor (LIF) were identified as essential molecules for this astrocytic differentiation using neutralizing antibodies and recombinant cytokines. Our results suggest that microglia as well as astrocytes contribute to the integrity of the local environment of NSPCs, and at least IL-6 and LIF released by activated microglia promote astrocytic differentiation of NSPCs via the activation of the JAK/STAT and MAPK pathways.

  16. Porosome in astrocytes.

    Science.gov (United States)

    Lee, Jin-Sook; Cho, Won Jin; Jeftinija, Ksenija; Jeftinija, Srdija; Jena, Bhanu P

    2009-02-01

    Secretion is a universal cellular process occurring in bakers yeast, to the complex multicellular organisms, to humans beings. Neurotransmission, digestion, immune response or the release of hormones occur as a result of cell secretion. Secretory defects result in numerous diseases and hence a molecular understanding of the process is critical. Cell secretion involves the transport of vesicular products from within cells to the outside. Porosomes are permanent cup-shaped supramolecular structures at the cell plasma membrane, where secretory vesicles transiently dock and transiently fuse to release intravesicular contents to the outside. In the past decade, porosomes have been determined to be the universal secretory machinery in cells, present in the exocrine pancreas, endocrine and neuroendocrine cells, and in neurons. In this study, we report for the first time the presence of porosomes in rat brain astrocytes. Using atomic force microscopy on live astrocytes, cup-shaped porosomes measuring 10-15 nm are observed at the cell plasma membrane. Further studies using electron microscopy confirm the presence of porosomes in astrocytes. Analogous to neuronal porosomes, there is a central plug in the astrocyte porosome complex. Immunoisolation and reconstitution of the astrocyte porosome in lipid membrane, demonstrates a structure similar to what is observed in live cells. These studies demonstrate that in astrocytes, the secretory apparatus at the cell plasma membrane is similar to what is found in neurons.

  17. Loss of Sparc in p53-null Astrocytes Promotes Macrophage Activation and Phagocytosis Resulting in Decreased Tumor Size and Tumor Cell Survival.

    Science.gov (United States)

    Thomas, Stacey L; Schultz, Chad R; Mouzon, Ezekiell; Golembieski, William A; El Naili, Reima; Radakrishnan, Archanna; Lemke, Nancy; Poisson, Laila M; Gutiérrez, Jorge A; Cottingham, Sandra; Rempel, Sandra A

    2015-07-01

    Both the induction of SPARC expression and the loss of the p53 tumor suppressor gene are changes that occur early in glioma development. Both SPARC and p53 regulate glioma cell survival by inverse effects on apoptotic signaling. Therefore, during glioma formation, the upregulation of SPARC may cooperate with the loss of p53 to enhance cell survival. This study determined whether the loss of Sparc in astrocytes that are null for p53 would result in reduced cell survival and tumor formation and increased tumor immunogenicity in an in vivo xenograft brain tumor model. In vitro, the loss of Sparc in p53-null astrocytes resulted in an increase in cell proliferation, but a loss of tumorigenicity. At 7 days after intracranial implantation, Sparc-null tumors had decreased tumor cell survival, proliferation and reduced tumor size. The loss of Sparc promoted microglia/macrophage activation and phagocytosis of tumor cells. Our results indicate that the loss of p53 by deletion/mutation in the early stages of glioma formation may cooperate with the induction of SPARC to potentiate cancer cell survival and escape from immune surveillance.

  18. Impaired APP activity and altered Tau splicing in embryonic stem cell-derived astrocytes obtained from an APPsw transgenic minipig

    DEFF Research Database (Denmark)

    Hall, Vanessa Jane; Lindblad, Maiken Marie; Jakobsen, Jannik E.;

    2015-01-01

    onset mechanisms related to cell renewal and function in familial AD astrocytes. These outcomes also highlight that radial glia could be a potentially useful population of cells for drug discovery, and that altered APP expression and altered tau phosphorylation can be detected in an in vitro model...

  19. Squamous cell skin cancer

    Science.gov (United States)

    ... that reflect light more, such as water, sand, concrete, and areas that are painted white. The higher ... - skin - squamous cell; Skin cancer - squamous cell; Nonmelanoma skin cancer - squamous ...

  20. Brain Cancer Stem Cells: Current Status on Glioblastoma Multiforme

    OpenAIRE

    2011-01-01

    Glioblastoma multiforme (GBM), an aggressive brain tumor of astrocytic/neural stem cell origin, represents one of the most incurable cancers. GBM tumors are highly heterogeneous. However, most tumors contain a subpopulation of cells that display neural stem cell characteristics in vitro and that can generate a new brain tumor upon transplantation in mice. Hence, previously identified molecular pathways regulating neural stem cell biology were found to represent the cornerstone of GBM stem cel...

  1. RNA Localization in Astrocytes

    DEFF Research Database (Denmark)

    Thomsen, Rune

    2012-01-01

    Messenger RNA (mRNA) localization is a mechanism by which polarized cells can regulate protein synthesis to specific subcellular compartments in a spatial and temporal manner, and plays a pivotal role in multiple physiological processes from embryonic development to cell differentiation......, regulation of the blood brain barrier and glial scar tissue formation. Despite the involvement in various CNS functions only a limited number of studies have addressed mRNA localization in astrocytes. This PhD project was initially focused on developing and implementing methods that could be used to asses mRNA...... localization in astrocyte protrusions, and following look into the subcellular localization pattern of specific mRNA species of both primary astrocytes isolated from cortical hemispheres of newborn mice, and the mouse astrocyte cell line, C8S. The Boyden chamber cell fractionation assay was optimized, in a way...

  2. GDNF facilitates differentiation of the adult dentate gyrus-derived neural precursor cells into astrocytes via STAT3

    Energy Technology Data Exchange (ETDEWEB)

    Boku, Shuken, E-mail: shuboku@med.hokudai.ac.jp [Department of Psychiatry, Hokkaido University Graduate School of Medicine, Sapporo (Japan); Nakagawa, Shin [Department of Psychiatry, Hokkaido University Graduate School of Medicine, Sapporo (Japan); Takamura, Naoki [Pharmaceutical Laboratories, Dainippon Sumitomo Pharma Co. Ltd., Osaka (Japan); Kato, Akiko [Department of Psychiatry, Hokkaido University Graduate School of Medicine, Sapporo (Japan); Takebayashi, Minoru [Department of Psychiatry, National Hospital Organization Kure Medical Center, Kure (Japan); Hisaoka-Nakashima, Kazue [Department of Pharmacology, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima (Japan); Omiya, Yuki; Inoue, Takeshi; Kusumi, Ichiro [Department of Psychiatry, Hokkaido University Graduate School of Medicine, Sapporo (Japan)

    2013-05-17

    Highlights: •GDNF has no effect on ADP proliferation and apoptosis. •GDNF increases ADP differentiation into astrocyte. •A specific inhibitor of STAT3 decreases the astrogliogenic effect of GDNF. •STAT3 knockdown by lentiviral shRNA vector also decreases the astrogliogenic effect of GDNF. •GDNF increases the phosphorylation of STAT3. -- Abstract: While the pro-neurogenic actions of antidepressants in the adult hippocampal dentate gyrus (DG) are thought to be one of the mechanisms through which antidepressants exert their therapeutic actions, antidepressants do not increase proliferation of neural precursor cells derived from the adult DG. Because previous studies showed that antidepressants increase the expression and secretion of glial cell line-derived neurotrophic factor (GDNF) in C6 glioma cells derived from rat astrocytes and GDNF increases neurogenesis in adult DG in vivo, we investigated the effects of GDNF on the proliferation, differentiation and apoptosis of cultured neural precursor cells derived from the adult DG. Data showed that GDNF facilitated the differentiation of neural precursor cells into astrocytes but had no effect on their proliferation or apoptosis. Moreover, GDNF increased the phosphorylation of STAT3, and both a specific inhibitor of STAT3 and lentiviral shRNA for STAT3 decreased their differentiation into astrocytes. Taken together, our findings suggest that GDNF facilitates astrogliogenesis from neural precursor cells in adult DG through activating STAT3 and that this action might indirectly affect neurogenesis.

  3. Influence of basement membrane proteins and endothelial cell-derived factors on the morphology of human fetal-derived astrocytes in 2D.

    Directory of Open Access Journals (Sweden)

    Amanda F Levy

    Full Text Available Astrocytes are the most prevalent type of glial cell in the brain, participating in a variety of diverse functions from regulating cerebral blood flow to controlling synapse formation. Astrocytes and astrocyte-conditioned media are widely used in models of the blood-brain barrier (BBB, however, very little is known about astrocyte culture in 2D. To test the hypothesis that surface coating and soluble factors influence astrocyte morphology in 2D, we quantitatively analyzed the morphology of human fetal derived astrocytes on glass, matrigel, fibronectin, collagen IV, and collagen I, and after the addition soluble factors including platelet-derived growth factor (PDGF, laminin, basic fibroblast growth factor (bFGF, and leukemia inhibitory factor (LIF. Matrigel surface coatings, as well as addition of leukemia inhibitory factor (LIF to the media, were found to have the strongest effects on 2D astrocyte morphology, and may be important in improving existing BBB models. In addition, the novel set of quantitative parameters proposed in this paper provide a test for determining the influence of compounds on astrocyte morphology, both to screen for new endothelial cell-secreted factors that influence astrocytes, and to determine in a high-throughput way which factors are important for translation to more complex, 3D BBB models.

  4. Manipulation of Schwann cell migration across the astrocyte boundary by polysialyltransferase-loaded superparamagnetic nanoparticles under magnetic field

    Directory of Open Access Journals (Sweden)

    Xia B

    2016-12-01

    Full Text Available Bing Xia,* Liangliang Huang,* Lei Zhu, Zhongyang Liu, Teng Ma, Shu Zhu, Jinghui Huang, Zhuojing Luo Department of Orthopaedics, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi, People’s Republic of China *These authors contributed equally to this work Abstract: Schwann cell (SC transplantation is an attractive strategy for spinal cord injury (SCI. However, the efficacy of SC transplantation has been limited by the poor migratory ability of SCs in the astrocyte-rich central nervous system (CNS environment and the inability to intermingle with the host astrocyte. In this study, we first magnetofected SCs by polysialyltransferase-functionalized superparamagnetic iron oxide nanoparticles (PST/SPIONs to induce overexpression of polysialylation of neural cell adhesion molecule (PSA-NCAM to enhance SC migration ability, before manipulating the direction of SC migration with the assistance of an applied magnetic field (MF. It was found that magnetofection with PST/SPIONs significantly upregulated the expression of PSA-NCAM in SCs, which significantly enhanced the migration ability of SCs, but without preferential direction in the absence of MF. The number and averaged maximum distance of SCs with PST/SPIONs migrating into the astrocyte domain were significantly enhanced by an applied MF. In a 300 µm row along the astrocyte boundary, the number of SCs with PST/SPIONs migrating into the astrocyte domain under an MF was 2.95 and 6.71 times higher than that in the absence of MF and the intact control SCs, respectively. More interestingly, a confrontation assay demonstrated that SCs with PST/SPIONs were in close contact with astrocytes and no longer formed boundaries in the presence of MF. In conclusion, SCs with PST/SPIONs showed enhanced preferential migration along the axis of a magnetic force, which might be beneficial for the formation of Büngner bands in the CNS. These findings raise the possibilities of enhancing the

  5. Astrocytes and Microglia as Non-cell Autonomous Players in the Pathogenesis of ALS

    Science.gov (United States)

    Hyeon, Seung Jae; Im, Hyeonjoo; Ryu, Hyun; Kim, Yunha

    2016-01-01

    Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disorder that leads to a progressive muscle wasting and paralysis. The pathological phenotypes are featured by severe motor neuron death and glial activation in the lumbar spinal cord. Proposed ALS pathogenic mechanisms include glutamate cytotoxicity, inflammatory pathway, oxidative stress, and protein aggregation. However, the exact mechanisms of ALS pathogenesis are not fully understood yet. Recently, a growing body of evidence provides a novel insight on the importance of glial cells in relation to the motor neuronal damage via the non-cell autonomous pathway. Accordingly, the aim of the current paper is to overview the role of astrocytes and microglia in the pathogenesis of ALS and to better understand the disease mechanism of ALS. PMID:27790057

  6. Astrocytes and Müller cells changes during retinal degeneration in a transgenic rat model of retinitis pigmentosa.

    Directory of Open Access Journals (Sweden)

    Laura eFernández-Sánchez

    2015-12-01

    Full Text Available Purpose: Retinitis pigmentosa includes a group of progressive retinal degenerative diseases that affect the structure and function of photoreceptors. Secondarily to the loss of photoreceptors, there is a reduction in retinal vascularization, which seems to influence the cellular degenerative process. Retinal macroglial cells, astrocytes and Müller cells provide support for retinal neurons and are fundamental for maintaining normal retinal function. The aim of this study was to investigate the evolution of macroglial changes during retinal degeneration in P23H rats. Methods: Homozygous P23H line-3 rats aged from P18 to 18 months were used to study the evolution of the disease, and SD rats were used as controls. Immunolabeling with antibodies against GFAP, vimentin, and transducin were used to visualize macroglial cells and cone photoreceptors. Results: In P23H rats, increased GFAP labeling in Müller cells was observed as an early indicator of retinal gliosis. At 4 and 12 months of age, the apical processes of Müller cells in P23H rats clustered in firework-like structures, which were associated with ring-like shaped areas of cone degeneration in the outer nuclear layer. These structures were not observed at 16 months of age. The number of astrocytes was higher in P23H rats than in the SD matched controls at 4 and 12 months of age, supporting the idea of astrocyte proliferation. As the disease progressed, astrocytes exhibited a deteriorated morphology and marked hypertrophy. The increase in the complexity of the astrocytic processes correlated with greater connexin 43 expression and higher density of connexin 43 immunoreactive puncta within the ganglion cell layer of P23H versus SD rat retinas. Conclusions: In the P23H rat model of retinitis pigmentosa, the loss of photoreceptors triggers major changes in the number and morphology of glial cells affecting the inner retina.

  7. GABAA increases calcium in subventricular zone astrocyte-like cells through L- and T-type voltage-gated calcium channels

    Directory of Open Access Journals (Sweden)

    Stephanie Z Young

    2010-04-01

    Full Text Available In the adult neurogenic subventricular zone (SVZ, the behavior of astrocyte-like cells and some of their functions depend on changes in intracellular Ca2+ levels and tonic GABAA receptor activation. However, it is unknown whether, and if so how, GABAA receptor activity regulates intracellular Ca2+ dynamics in SVZ astrocytes. To monitor Ca2+ activity selectively in astrocyte-like cells, we used two lines of transgenic mice expressing either GFP fused to a Gq-coupled receptor or DsRed under the human glial fibrillary acidic protein (hGFAP promoter. GABAA receptor activation induced Ca2+ increases in 40-50% of SVZ astrocytes. GABAA-induced Ca2+ increases were prevented with nifedipine and mibefradil, blockers of L- and T-type voltage-gated calcium channels (VGCC. The L-type Ca2+ channel activator BayK 8644 increased the percentage of GABAA-responding astrocyte-like cells to 75%, suggesting that the majority of SVZ astrocytes express functional VGCCs. SVZ astrocytes also displayed spontaneous Ca2+ activity, the frequency of which was regulated by tonic GABAA receptor activation. These data support a role for ambient GABA in tonically regulating intracellular Ca2+ dynamics through GABAA receptors and VGCC in a subpopulation of astrocyte-like cells in the postnatal SVZ.

  8. Imipramine activates glial cell line-derived neurotrophic factor via early growth response gene 1 in astrocytes.

    Science.gov (United States)

    Kim, Yeni; Kim, Se Hyun; Kim, Yong Sik; Lee, Young Han; Ha, Kyooseob; Shin, Soon Young

    2011-06-01

    Recent evidence has suggested that deficits in glial plasticity contribute to the pathophysiology of depressive disorders. The present study explored early growth response 1 (EGR-1) transcriptional regulation of imipramine-induced glial cell line-derived neurotrophic factor (GDNF) expression in astrocytes. After we observed the induction of GDNF mRNA expression in rat astrocytes in response to imipramine, deletion mutant studies showed that the proximal region between -493 and -114 of the GDNF promoter, which contains three binding sites for EGR-1, was essential for maximal imipramine-induced activation of GDNF promoter. The dose-dependent upregulation of EGR-1 by imipramine, the activation of GDNF by the over-expression of EGR-1 without imipramine and the reduction in the imipramine-induced GDNF mRNA expression after silencing of endogenous EGR-1 demonstrated that EGR-1 is upregulated by imipramine to activate the GDNF promoter. Furthermore, imipramine-induced GDNF mRNA expression was strongly attenuated in primary astrocytes from Egr-1(-/-) mice, and the immunoreactivity to an anti-GDNF antibody in glial fibrillary acidic protein-positive cells was lower in imipramine-treated astrocytes from Egr-1(-/-) mice than in those from Egr-1(+/-) mice. To determine whether mitogen-activated protein kinases (MAPKs) were associated with imipramine-induced EGR-1 expression, we examined the induction of MAPK phosphorylation in response to imipramine. Pretreatment of rat primary astrocytes with the MAPK kinase inhibitor U0126 or the JNK inhibitor SP600125 strongly inhibited imipramine-stimulated EGR-1 expression. In conclusion, we found that imipramine induction of EGR-1 upregulated GDNF in astrocytes in a dose-dependent manner. This upregulation may occur through the MEK/ERK and JNK MAPK pathways, which suggests a new therapeutic mechanism of action for depressive disorders.

  9. Light and electron microscopic localization of GABAA-receptors on cultured cerebellar granule cells and astrocytes using immunohistochemical techniques

    DEFF Research Database (Denmark)

    Hansen, G H; Hösli, E; Belhage, B;

    1991-01-01

    GABAA-receptors were localized in explant cultures of rat cerebellum and in dissociated primary cultures of rat cerebellar granule cells and rat cerebellar astrocytes using the monoclonal antibody bd-17 directed against the beta-subunit of the GABAA/benzodiazepine/chloride channel complex. At the...

  10. High-efficient generation of induced pluripotent stem cells from human astrocytes.

    Science.gov (United States)

    Ruiz, Sergio; Brennand, Kristen; Panopoulos, Athanasia D; Herrerías, Aída; Gage, Fred H; Izpisua-Belmonte, Juan Carlos

    2010-12-09

    The reprogramming of human somatic cells to induced pluripotent stem (hiPS) cells enables the possibility of generating patient-specific autologous cells for regenerative medicine. A number of human somatic cell types have been reported to generate hiPS cells, including fibroblasts, keratinocytes and peripheral blood cells, with variable reprogramming efficiencies and kinetics. Here, we show that human astrocytes can also be reprogrammed into hiPS (ASThiPS) cells, with similar efficiencies to keratinocytes, which are currently reported to have one of the highest somatic reprogramming efficiencies. ASThiPS lines were indistinguishable from human embryonic stem (ES) cells based on the expression of pluripotent markers and the ability to differentiate into the three embryonic germ layers in vitro by embryoid body generation and in vivo by teratoma formation after injection into immunodeficient mice. Our data demonstrates that a human differentiated neural cell type can be reprogrammed to pluripotency and is consistent with the universality of the somatic reprogramming procedure.

  11. High-efficient generation of induced pluripotent stem cells from human astrocytes.

    Directory of Open Access Journals (Sweden)

    Sergio Ruiz

    Full Text Available The reprogramming of human somatic cells to induced pluripotent stem (hiPS cells enables the possibility of generating patient-specific autologous cells for regenerative medicine. A number of human somatic cell types have been reported to generate hiPS cells, including fibroblasts, keratinocytes and peripheral blood cells, with variable reprogramming efficiencies and kinetics. Here, we show that human astrocytes can also be reprogrammed into hiPS (ASThiPS cells, with similar efficiencies to keratinocytes, which are currently reported to have one of the highest somatic reprogramming efficiencies. ASThiPS lines were indistinguishable from human embryonic stem (ES cells based on the expression of pluripotent markers and the ability to differentiate into the three embryonic germ layers in vitro by embryoid body generation and in vivo by teratoma formation after injection into immunodeficient mice. Our data demonstrates that a human differentiated neural cell type can be reprogrammed to pluripotency and is consistent with the universality of the somatic reprogramming procedure.

  12. Mesoporous silica nanoparticles enhance MTT formazan exocytosis in HeLa cells and astrocytes.

    Science.gov (United States)

    Fisichella, Matthieu; Dabboue, Hinda; Bhattacharyya, Sanjib; Saboungi, Marie-Louise; Salvetat, Jean-Paul; Hevor, Tobias; Guerin, Martine

    2009-06-01

    We report on the observation that mesoporous silica nanoparticles (MSNs), after being endocytosed, interfere with the MTT test in HeLa cells and astrocytes by accelerating the exocytosis of formazan crystals. The stimulation of MTT formazan exocytosis is probably related to perturbation of intracellular vesicle trafficking by MSN uptake as revealed by experiments in presence of chloroquine and genistein. Similar effect has been previously observed with a number of chemicals, especially with neurotoxic beta amyloid peptides, but not with nanoparticles. We showed also that MTT reduction test gives an overestimation of the cytotoxicity of mesoporous silica nanoparticles compared to other tests such as LDH activity, WST-1 test and flow cytometry. These findings show that MTT assay should not be used for the study of MSN toxicity, and that perturbation of intracellular trafficking has to be taken into account in evaluating biocompatibility of MSNs.

  13. Generation of human pluripotent stem cell reporter lines for the isolation of and reporting on astrocytes generated from ventral midbrain and ventral spinal cord neural progenitors

    Directory of Open Access Journals (Sweden)

    Staffan Holmqvist

    2015-07-01

    Full Text Available Astrocytes play a critical role during the development and the maintenance of the CNS in health and disease. Yet, their lack of accessibility from fetuses and from the brain of diseased patients has hindered our understanding of their full implication in developmental and pathogenic processes. Human pluripotent stem cells (PSCs are an alternative source to obtain large quantities of astrocytes in vitro, for mechanistic studies of development and disease. However, these studies often require highly pure populations of astrocytes, which are not always achieved, depending on the PSC lines and protocols used. Here, we describe the generation and characterization of human PSC reporter lines expressing TagRFP driven by the ABC1D region of the human GFAP promoter, as new cellular model for generating homogenous population of astrocytes generated from CNS regionally defined PSC-derived neural progenitors. GFAABC1D::TagRFP-expressing astrocytes can be purified by fluorescent-activated cell sorting and maintain a bright expression for several additional weeks. These express canonical astrocyte markers NF1A, S100β, CX43, GLAST, GS and CD44. These new cellular models, from which highly pure populations of fluorescence-expressing astrocytes can be obtained, provide a new platform for studies where pure or fluorescently labeled astrocyte populations are necessary, for example to assess pro-inflammatory cytokine and chemokine release in response to specific treatment, and uptake and degradation of fluorescently labeled pathogenic proteins, as reported in this study.

  14. Determining the Oxidation States of Manganese in NT2 Cells and Cultured Astrocytes

    Energy Technology Data Exchange (ETDEWEB)

    Gunter,K.; Aschner, M.; Miller, L.; Eliseev, R.; Salter, J.; Andersen, K.; Gunter, T.

    2006-01-01

    Excessive brain manganese (Mn) can produce a syndrome called 'manganism', which correlates with loss of striatal dopamine and cell death in the striatum and globus pallidus. The prevalent hypothesis for the cause of this syndrome has been oxidation of cell components by the strong oxidizing agent, Mn{sup 3+}, either formed by oxidation of intracellular Mn{sup 2+} or transported into the cell as Mn{sup 3+}. We have recently used X-ray absorption near edge structure spectroscopy (XANES) to determine the oxidation states of manganese complexes in brain and liver mitochondria and in nerve growth factor (NGF)-induced and non-induced PC12 cells. No evidence was found for stabilization or accumulation of Mn{sup 3+} complexes because of oxidation of Mn{sup 2+} by reactive oxygen species in these tissues. Here we extend these studies of manganese oxidation state to cells of brain origin, human neuroteratocarcinoma (NT2) cells and primary cultures of rat astrocytes. Again we find no evidence for stabilization or accumulation of any Mn{sup 3+} complex derived from oxidation of Mn{sup 2+} under a range of conditions.

  15. Culturing of PC12 Cells, Neuronal Cells, Astrocytes Cultures and Brain Slices in an Open Microfluidic System

    DEFF Research Database (Denmark)

    Al Atraktchi, Fatima Al-Zahraa; Bakmand, Tanya; Rømer Sørensen, Ane

    cells, neuronal cells, astrocytes cultures and brain slices. The microfluidic system provides efficient nutrient delivery, waste removal, access to oxygen, fine control over the neurochemical environment and access to modern microscopy. Additionally, the setup consists of an in vitro culturing......The brain is the center of the nervous system, where serious neurodegenerative diseases such as Parkinson’s, Alzheimer’s and Huntington’s are products of functional loss in the neural cells (1). Typical techniques used to investigate these diseases lack precise control of the cellular surroundings...... and electrochemical sensor system that enables real time detection of metabolites, e.g. dopamine from cell cultures and brain slices. In summary we present results on culturing of brain slices and cells in the microfluidic system as well as on the incorporation of an electrochemical sensor system for characterization...

  16. Immunochemical expression of proliferative cell nuclear antigen in aging cultured astrocytes

    Directory of Open Access Journals (Sweden)

    M. C. Vanzani

    2003-08-01

    Full Text Available Cell differentiation degree and mitotic activity were sequentially assessed by immunoperoxidase labeling of glial fibrillary acidic protein (GFAP and proliferative cell nuclear antigen (PCNA, respectively, in rat brain cultured astrocytes maintained up to 60 days in vitro (DIV of first subculture, or weekly passaged until their 12th subculture. Cell count was performed through a 0.01 mm2 section reticule and morphometric analysis with a stereological grid. The number of double immunoreactive cells peaked by 2 DIV to achieve its lowest value at 60 DIV. At 24 hs of cell seeding of successive passages, such values peaked by the 6th subculture to gradually decrease thereafter. Increasing cell hypertrophy was found during the long-term first subculture but not after passaging. At the end of the observation period, doubly immunolabeled astrocytes were still recorded, thus evidencing retention of proliferative potential despite aging.El grado de diferenciación celular y la actividad mitótica fueron secuencialmente determinados mediante marcación por inmunoperoxidasa de la proteína gliofibrilar ácida (GFAP y del antígeno nuclear de proliferación celular (PCNA, respectivamente, en cultivos astrocitarios obtenidos de encéfalo de rata y mantenidos hasta 60 días in vitro (DIV de su primer subcultivo, o mediante pasajes semanales hasta el 12do subcultivo. El conteo celular se realizó mediante una retícula de 0.01-mm2 de sección y el análisis morfométrico con una grilla estereológica. El número de células doblemente inmunorreactivas alcanzó valores máximos a los 2 DIV para descender a los menores a los 60 DIV. A las 24 hs de sembrado celular de los sucesivos pasajes, esos valores ascendieron hacia el 6to subcultivo para luego declinar. En cuanto a la hipertrofia celular, se observó en todo el curso del primer subcultivo, pero no durante los posteriores pasajes. Al final del período de observación, todavía se continuaban detectando

  17. Neural Stem Cell Transplantation Induces Stroke Recovery by Upregulating Glutamate Transporter GLT-1 in Astrocytes

    Science.gov (United States)

    Russo, Gianluca Luigi; Peruzzotti-Jametti, Luca; Rossi, Silvia; Sandrone, Stefano; Butti, Erica; De Ceglia, Roberta; Bergamaschi, Andrea; Motta, Caterina; Gallizioli, Mattia; Studer, Valeria; Colombo, Emanuela; Farina, Cinthia; Comi, Giancarlo; Politi, Letterio Salvatore; Muzio, Luca; Villani, Claudia; Invernizzi, Roberto William; Hermann, Dirk Matthias; Centonze, Diego

    2016-01-01

    Ischemic stroke is the leading cause of disability, but effective therapies are currently widely lacking. Recovery from stroke is very much dependent on the possibility to develop treatments able to both halt the neurodegenerative process as well as to foster adaptive tissue plasticity. Here we show that ischemic mice treated with neural precursor cell (NPC) transplantation had on neurophysiological analysis, early after treatment, reduced presynaptic release of glutamate within the ipsilesional corticospinal tract (CST), and an enhanced NMDA-mediated excitatory transmission in the contralesional CST. Concurrently, NPC-treated mice displayed a reduced CST degeneration, increased axonal rewiring, and augmented dendritic arborization, resulting in long-term functional amelioration persisting up to 60 d after ischemia. The enhanced functional and structural plasticity relied on the capacity of transplanted NPCs to localize in the peri-ischemic and ischemic area, to promote the upregulation of the glial glutamate transporter 1 (GLT-1) on astrocytes and to reduce peri-ischemic extracellular glutamate. The upregulation of GLT-1 induced by transplanted NPCs was found to rely on the secretion of VEGF by NPCs. Blocking VEGF during the first week after stroke reduced GLT-1 upregulation as well as long-term behavioral recovery in NPC-treated mice. Our results show that NPC transplantation, by modulating the excitatory–inhibitory balance and stroke microenvironment, is a promising therapy to ameliorate disability, to promote tissue recovery and plasticity processes after stroke. SIGNIFICANCE STATEMENT Tissue damage and loss of function occurring after stroke can be constrained by fostering plasticity processes of the brain. Over the past years, stem cell transplantation for repair of the CNS has received increasing interest, although underlying mechanism remain elusive. We here show that neural stem/precursor cell transplantation after ischemic stroke is able to foster

  18. Testosterone Protects Mitochondrial Function and Regulates Neuroglobin Expression in Astrocytic Cells Exposed to Glucose Deprivation

    Science.gov (United States)

    Toro-Urrego, Nicolas; Garcia-Segura, Luis M.; Echeverria, Valentina; Barreto, George E.

    2016-01-01

    Testosterone is a hormone that has been shown to confer neuroprotection from different insults affecting the central nervous system (CNS). Testosterone induces this protection by different mechanisms that include the activation of anti-apoptotic pathways that are directly implicated in neuronal survival. However, little attention has been devoted to its actions on glial cells. In the present study, we have assessed whether testosterone exerts protection in a human astrocyte cell model, the T98G cells. Our results indicate that testosterone improves cell survival and mitochondrial membrane potential and reduces nuclear fragmentation and reactive oxygen species (ROS) generation. These effects were accompanied by a positive regulation of neuroglobin, an oxygen-binding and sensor protein, which may serve as a regulator of ROS and nitrogen reactive species (NOS), and these protective effects of testosterone may be at least in part mediated by estradiol and DHT. In conclusion, these findings suggest that astroglia may mediate some of the protective actions of testosterone in the brain upon pathological conditions. PMID:27445795

  19. Neural Crest Cells Contribute an Astrocyte-like Glial Population to the Spleen

    Science.gov (United States)

    Barlow-Anacker, Amanda J.; Fu, Ming; Erickson, Christopher S.; Bertocchini, Federica; Gosain, Ankush

    2017-01-01

    Neural crest cells (NCC) are multi-potent cells of ectodermal origin that colonize diverse organs, including the gastrointestinal tract to form the enteric nervous system (ENS) and hematopoietic organs (bone marrow, thymus) where they participate in lymphocyte trafficking. Recent studies have implicated the spleen as an anatomic site for integration of inflammatory signals from the intestine with efferent neural inputs. We have previously observed alterations in splenic lymphocyte subsets in animals with defective migration of NCC that model Hirschsprung’s disease, leading us to hypothesize that there may be a direct cellular contribution of NCC to the spleen. Here, we demonstrate that NCC colonize the spleen during embryogenesis and persist into adulthood. Splenic NCC display markers indicating a glial lineage and are arranged anatomically adjacent to blood vessels, pericytes and nerves, suggesting an astrocyte-like phenotype. Finally, we identify similar neural-crest derived cells in both the avian and non-human primate spleen, showing evolutionary conservation of these cells. PMID:28349968

  20. Modeling astrocytoma pathogenesis in vitro and in vivo using cortical astrocytes or neural stem cells from conditional, genetically engineered mice.

    Science.gov (United States)

    McNeill, Robert S; Schmid, Ralf S; Bash, Ryan E; Vitucci, Mark; White, Kristen K; Werneke, Andrea M; Constance, Brian H; Huff, Byron; Miller, C Ryan

    2014-08-12

    Current astrocytoma models are limited in their ability to define the roles of oncogenic mutations in specific brain cell types during disease pathogenesis and their utility for preclinical drug development. In order to design a better model system for these applications, phenotypically wild-type cortical astrocytes and neural stem cells (NSC) from conditional, genetically engineered mice (GEM) that harbor various combinations of floxed oncogenic alleles were harvested and grown in culture. Genetic recombination was induced in vitro using adenoviral Cre-mediated recombination, resulting in expression of mutated oncogenes and deletion of tumor suppressor genes. The phenotypic consequences of these mutations were defined by measuring proliferation, transformation, and drug response in vitro. Orthotopic allograft models, whereby transformed cells are stereotactically injected into the brains of immune-competent, syngeneic littermates, were developed to define the role of oncogenic mutations and cell type on tumorigenesis in vivo. Unlike most established human glioblastoma cell line xenografts, injection of transformed GEM-derived cortical astrocytes into the brains of immune-competent littermates produced astrocytomas, including the most aggressive subtype, glioblastoma, that recapitulated the histopathological hallmarks of human astrocytomas, including diffuse invasion of normal brain parenchyma. Bioluminescence imaging of orthotopic allografts from transformed astrocytes engineered to express luciferase was utilized to monitor in vivo tumor growth over time. Thus, astrocytoma models using astrocytes and NSC harvested from GEM with conditional oncogenic alleles provide an integrated system to study the genetics and cell biology of astrocytoma pathogenesis in vitro and in vivo and may be useful in preclinical drug development for these devastating diseases.

  1. Cell phones and cancer

    Science.gov (United States)

    Cancer and cell phones; Do cell phones cause cancer? ... Several major studies show no link between cell phones and cancer at this time. However, since the information available is based on short-term studies, the impact of many years of ...

  2. Lung Cancer Stem Cells

    Directory of Open Access Journals (Sweden)

    Sharon R. Pine

    2008-01-01

    Full Text Available Lung cancer remains a major cause of cancer-related lethality because of high incidence and recurrence in spite of significant advances in staging and therapies. Recent data indicates that stem cells situated throughout the airways may initiate cancer formation. These putative stem cells maintain protumorigenic characteristics including high proliferative capacity, multipotent differentiation, drug resistance and long lifespan relative to other cells. Stem cell signaling and differentiation pathways are maintained within distinct cancer types, and destabilization of this machinery may participate in maintenance of cancer stem cells. Characterization of lung cancer stem cells is an area of active research and is critical for developing novel therapies. This review summarizes the current knowledge on stem cell signaling pathways and cell markers used to identify the lung cancer stem cells.

  3. GDNF reverses the inhibitory properties of reactive astrocytes allowing robust axonal regeneration through Schwann cell-seeded guidance channels after spinal cord injury

    OpenAIRE

    Deng, Ling-Xiao; Hu, Jianguo; Liu, Naikui; Wang, Xiaofei; Smith, George M.; Wen, Xuejun; Xu, Xiao-Ming

    2011-01-01

    Reactive astrogliosis has been considered as a major impediment for axonal regeneration after injuries in the mammalian central nervous system (CNS). Here we report that glial cell line-derived neurotrophic factor (GDNF), combined with transplanted Schwann cells (SCs), effectively reversed the inhibitory properties of astrocytes at graft-host interfaces allowing robust axonal regeneration, concomitant with vigorous migration of host astrocytes, into SC-seeded semi-permeable guidance channels ...

  4. Effects of Kynurenine Pathway Metabolites on Intracellular NAD+ Synthesis and Cell Death in Human Primary Astrocytes and Neurons

    Directory of Open Access Journals (Sweden)

    Nady Braidy

    2009-01-01

    Full Text Available The kynurenine pathway (KP is a major route of L-tryptophan catabolism resulting in the production of the essential pyridine nucleotide nicotinamide adenine dinucleotide, (NAD+. Up-regulation of the KP during inflammation leads to the release of a number of biologically active metabolites into the brain. We hypothesised that while some of the extracellular KP metabolites may be beneficial for intracellular NAD+ synthesis and cell survival at physiological concentrations, they may contribute to neuronal and astroglial dysfunction and cell death at pathophysiological concentrations. In this study, we found that treatment of human primary neurons and astrocytes with 3-hydroxyanthranilic acid (3-HAA, 3-hydroxykynurenine (3-HK, quinolinic acid (QUIN, and picolinic acid (PIC at concentrations below 100 nM significantly increased intracellular NAD+ levels compared to non-treated cells. However, a dose dependent decrease in intracellular NAD+ levels and increased extracellular LDH activity was observed in human astrocytes and neurons treated with 3-HAA, 3-HK, QUIN and PIC at concentrations 100 nM and kynurenine (KYN, at concentrations above 1 μM. Intracellular NAD+ levels were unchanged in the presence of the neuroprotectant, kynurenic acid (KYNA, and a dose dependent increase in intracellular NAD+ levels was observed for TRP up to 1 mM. While anthranilic acid (AA increased intracellular NAD+ levels at concentration below 10 μM in astrocytes. NAD+ depletion and cell death was observed in AA treated neurons at concentrations above 500 nM. Therefore, the differing responses of astrocytes and neurons to an increase in KP metabolites should be considered when assessing KP toxicity during neuroinflammation.

  5. Exposure to Cell Phone Radiation Up-Regulates Apoptosis Genes in Primary Cultures of Neurons and Astrocytes

    OpenAIRE

    Zhao, Tian-Yong; Zou, Shi-Ping; Pamela E Knapp

    2006-01-01

    The health effects of cell phone radiation exposure are a growing public concern. This study investigated whether expression of genes related to cell death pathways are dysregulated in primary cultured neurons and astrocytes by exposure to a working GSM (Global System for Mobile Communication) cell phone rated at a frequency of 1900 MHz. Primary cultures were exposed to cell phone emissions for 2 hrs. We used array analysis and real-time RT-PCR to show up-regulation of caspase-2, caspase-6 an...

  6. Xanthohumol induces different cytotoxicity and apoptotic pathways in malignant and normal astrocytes.

    Science.gov (United States)

    Zajc, I; Filipič, M; Lah, T T

    2012-11-01

    Cytotoxicity and the mechanisms of cell death induced by xanthohumol (XN) were compared in normal and cancerous human cells as the differences may be relevant for the potential use of XN in cancer therapy. The cancer cells seemed to be more susceptible to the cytotoxicity of XN than normal cells, but a significant difference was observed only in astrocytic cells. XN induced a higher rate of apoptosis in glioblastoma cells than in normal astrocytes, which was associated with activation of p53 and an elevated Bax/Bcl-2 ratio in glioblastoma cells, indicating an intrinsic caspase-dependent apoptotic pathway. In contrast, a reduced Bax/Bcl-2 ratio was observed in normal human astrocytes. This was also associated with higher expression of the cell cycle inhibitor, p21, in glioblastoma cells than in normal astrocytes. In addition, at a lower, non-cytotoxic concentration, XN partially inhibited the invasiveness of glioblastoma cells. Due to the selective sensitivity of astrocytic cells to XN, this compound should be studied further as a candidate for adjuvant therapy in the treatment of glioma.

  7. Orexin-A promotes cell migration in cultured rat astrocytes via Ca2+-dependent PKCα and ERK1/2 signals.

    Directory of Open Access Journals (Sweden)

    Qing Shu

    Full Text Available Orexin-A is an important neuropeptide involved in the regulation of feeding, arousal, energy consuming, and reward seeking in the body. The effects of orexin-A have widely studied in neurons but not in astrocytes. Here, we report that OX1R and OX2R are expressed in cultured rat astrocytes. Orexin-A stimulated the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2, and then induced the migration of astrocytes via its receptor OX1R but not OX2R. Orexin-A-induced ERK1/2 phosphorylation and astrocytes migration are Ca2+-dependent, since they could be inhibited by either chelating the extracellular Ca2+ or blocking the pathway of store-operated calcium entry (SOCE. Furthermore, both non-selective protein kinase C (PKC inhibitor and PKCα selective inhibitor, but not PKCδ inhibitor, prevented the increase in ERK1/2 phosphorylation and the migration of astrocytes, indicating that the Ca2+-dependent PKCα acts as the downstream of the OX1R activation and mediates the orexin-A-induced increase in ERK1/2 phosphorylation and cell migration. In conclusion, these results suggest that orexin-A can stimulate ERK1/2 phosphorylation and then facilitate the migration of astrocytes via PLC-PKCα signal pathway, providing new knowledge about the functions of the OX1R in astrocytes.

  8. Impaired APP activity and altered Tau splicing in embryonic stem cell-derived astrocytes obtained from an APPsw transgenic minipig

    Directory of Open Access Journals (Sweden)

    Vanessa J. Hall

    2015-10-01

    Full Text Available Animal models of familial juvenile onset of Alzheimer's disease (AD often fail to produce diverse pathological features of the disease by modification of single gene mutations that are responsible for the disease. They can hence be poor models for testing and development of novel drugs. Here, we analyze in vitro-produced stem cells and their derivatives from a large mammalian model of the disease created by overexpression of a single mutant human gene (APPsw. We produced hemizygous and homozygous radial glial-like cells following culture and differentiation of embryonic stem cells (ESCs isolated from embryos obtained from mated hemizygous minipigs. These cells were confirmed to co-express varying neural markers, including NES, GFAP and BLBP, typical of type one radial glial cells (RGs from the subgranular zone. These cells had altered expression of CCND1 and NOTCH1 and decreased expression of several ribosomal RNA genes. We found that these cells were able to differentiate into astrocytes upon directed differentiation. The astrocytes produced had decreased α- and β-secretase activity, increased γ-secretase activity and altered splicing of tau. This indicates novel aspects of early onset mechanisms related to cell renewal and function in familial AD astrocytes. These outcomes also highlight that radial glia could be a potentially useful population of cells for drug discovery, and that altered APP expression and altered tau phosphorylation can be detected in an in vitro model of the disease. Finally, it might be possible to use large mammal models to model familial AD by insertion of only a single mutation.

  9. A co-culture model of the hippocampal neurogenic niche reveals differential effects of astrocytes, endothelial cells and pericytes on proliferation and differentiation of adult murine precursor cells

    Directory of Open Access Journals (Sweden)

    Fanny Ehret

    2015-11-01

    Full Text Available The niche concept of stem cell biology proposes a functional unit between the precursor cells and their local microenvironment, to which several cell types might contribute by cell–cell contacts, extracellular matrix, and humoral factors. We here established three co-culture models (with cell types separated by membrane for both adherent monolayers and neurospheres to address the potential influence of different niche cell types in the neurogenic zone of the adult hippocampus of mice. Astrocytes and endothelial cells enhanced precursor cell proliferation and neurosphere formation. Endothelial factors also led to a prolonged increase in proliferation after growth factor withdrawal, which otherwise induces differentiation. All niche cell types enhanced cell survival in monolayer cultures, endothelial cells also stimulated neuronal differentiation. A parallel trend elicited by astrocytes did not reach conventional statistical significance. Pericytes had variable effects here. We did not observe changes in differentiation in neurosphere co-cultures. In summary, our data indicate that in precursor cell culture protocols survival could be improved by adding as yet unknown factors physiologically contributed by astrocytes and endothelial cells. Our findings also underscore the complexity of the niche and the differential impact of factors from the different sources on distinct aspects of neuronal development. With the help of the models presented here, identification of these factors and their specific biological activity can now be initiated.

  10. Stages of Renal Cell Cancer

    Science.gov (United States)

    ... cell cancer is a disease in which malignant (cancer) cells form in tubules of the kidney. Renal cell ... diagnosed, tests are done to find out if cancer cells have spread within the kidney or to other ...

  11. Osteopontin is induced by TGF-β2 and regulates metabolic cell activity in cultured human optic nerve head astrocytes.

    Directory of Open Access Journals (Sweden)

    Carolin Neumann

    Full Text Available The aqueous humor (AH component transforming growth factor (TGF-β2 is strongly correlated to primary open-angle glaucoma (POAG, and was shown to up-regulate glaucoma-associated extracellular matrix (ECM components, members of the ECM degradation system and heat shock proteins (HSP in primary ocular cells. Here we present osteopontin (OPN as a new TGF-β2 responsive factor in cultured human optic nerve head (ONH astrocytes. Activation was initially demonstrated by Oligo GEArray microarray and confirmed by semiquantitative (sq RT-PCR, realtime RT-PCR and western blot. Expressions of most prevalent OPN receptors CD44 and integrin receptor subunits αV, α4, α 5, α6, α9, β1, β3 and β5 by ONH astrocytes were shown by sqRT-PCR and immunofluorescence labeling. TGF-β2 treatment did not affect their expression levels. OPN did not regulate gene expression of described TGF-β2 targets shown by sqRT-PCR. In MTS-assays, OPN had a time- and dose-dependent stimulating effect on the metabolic activity of ONH astrocytes, whereas TGF-β2 significantly reduced metabolism. OPN signaling via CD44 mediated a repressive outcome on metabolic activity, whereas signaling via integrin receptors resulted in a pro-metabolic effect. In summary, our findings characterize OPN as a TGF-β2 responsive factor that is not involved in TGF-β2 mediated ECM and HSP modulation, but affects the metabolic activity of astrocytes. A potential involvement in a protective response to TGF-β2 triggered damage is indicated, but requires further investigation.

  12. MK-801 treatment affects glycolysis in oligodendrocytes more than in astrocytes and neuronal cells: insights for schizophrenia

    Directory of Open Access Journals (Sweden)

    Paul C Guest

    2015-05-01

    Full Text Available As a multifactorial disease, the underlying causes of schizophrenia require analysis by multiplex methods such as proteomics to allow identification of whole protein networks. Previous post-mortem proteomic studies on brain tissues from schizophrenia patients have demonstrated changes in activation of glycolytic and energy metabolism pathways. However, it is not known whether these changes occur in neurons or in glial cells. To address this question, we treated neuronal, astrocyte and oligodendrocyte cell lines with the NMDA receptor antagonist MK-801 and measured the levels of six glycolytic enzymes by Western blot analysis. MK-801 acts on the glutamatergic system and has been proposed as a pharmacological means of modeling schizophrenia. Treatment with MK-801 resulted in significant changes in the levels of glycolytic enzymes in all cell types. Most of the differences were found in oligodendrocytes, which had altered levels of hexokinase 1 (HK1, enolase 2 (ENO2, phosphoglycerate kinase (PGK and phosphoglycerate mutase 1 (PGAM1 after acute MK-801 treatment (8 hours, and HK1, ENO2, PGK and triosphosphate isomerase (TPI following long term treatment (72 hours. Addition of the antipsychotic clozapine to the cultures resulted in counter-regulatory effects to the MK-801 treatment by normalizing the levels of ENO2 and PGK in both the acute and long term cultures. In astrocytes, MK-801 affected only aldolase C (ALDOC under both acute conditions and HK1 and ALDOC following long term treatment, and TPI was the only enzyme affected under long term conditions in the neuronal cells. In conclusion, MK-801 affects glycolysis in oligodendrocytes to a larger extent than neuronal cells and this may be modulated by antipsychotic treatment. Although cell culture studies do not necessarily reflect the in vivo pathophysiology and drug effects within the brain, these results suggest that neurons, astrocytes and oligodendrocytes are affected differently in

  13. Regional Susceptibility to Domoic Acid in Primary Astrocyte Cells Cultured from the Brain Stem and Hippocampus

    Directory of Open Access Journals (Sweden)

    Olga M. Pulido

    2008-02-01

    Full Text Available Domoic acid is a marine biotoxin associated with harmful algal blooms and is the causative agent of amnesic shellfish poisoning in marine animals and humans. It is also an excitatory amino acid analog to glutamate and kainic acid which acts through glutamate receptors eliciting a very rapid and potent neurotoxic response. The hippocampus, among other brain regions, has been identified as a specific target site having high sensitivity to DOM toxicity. Histopathology evidence indicates that in addition to neurons, the astrocytes were also injured. Electron microscopy data reported in this study further supports the light microscopy findings. Furthermore, the effect of DOM was confirmed by culturing primary astrocytes from the hippocampus and the brain stem and subsequently exposing them to domoic acid. The RNA was extracted and used for biomarker analysis. The biomarker analysis was done for the early response genes including c-fos, c-jun, c-myc, Hsp-72; specific marker for the astrocytes- GFAP and the glutamate receptors including GluR 2, NMDAR 1, NMDAR 2A and B. Although, the astrocyte-GFAP and c-fos were not affected, c-jun and GluR 2 were down-regulated. The microarray analysis revealed that the chemokines / cytokines, tyrosine kinases (Trk, and apoptotic genes were altered. The chemokines that were up-regulated included - IL1-a, IL-1B, IL-6, the small inducible cytokine, interferon protein IP-10, CXC chemokine LIX, and IGF binding proteins. The Bax, Bcl-2, Trk A and Trk B were all downregulated. Interestingly, only the hippocampal astrocytes were affected. Our findings suggest that astrocytes may present a possible target for pharmacological interventions for the prevention and treatment of amnesic shellfish poisoning and for other brain pathologies involving excitotoxicity

  14. Increased toll-like receptor 4 in cerebral endothelial cells contributes to the astrocyte swelling and brain edema in acute hepatic encephalopathy.

    Science.gov (United States)

    Jayakumar, Arumugam R; Tong, Xiao Y; Curtis, Kevin M; Ruiz-Cordero, Roberto; Abreu, Maria T; Norenberg, Michael D

    2014-03-01

    Astrocyte swelling and the subsequent increase in intracranial pressure and brain herniation are major clinical consequences in patients with acute hepatic encephalopathy. We recently reported that conditioned media from brain endothelial cells (ECs) exposed to ammonia, a mixture of cytokines (CKs) or lipopolysaccharide (LPS), when added to astrocytes caused cell swelling. In this study, we investigated the possibility that ammonia and inflammatory agents activate the toll-like receptor 4 (TLR4) in ECs, resulting in the release of factors that ultimately cause astrocyte swelling. We found a significant increase in TLR4 protein expression when ECs were exposed to ammonia, CKs or LPS alone, while exposure of ECs to a combination of these agents potentiate such effects. In addition, astrocytes exposed to conditioned media from TLR4-silenced ECs that were treated with ammonia, CKs or LPS, resulted in a significant reduction in astrocyte swelling. TLR4 protein up-regulation was also detected in rat brain ECs after treatment with the liver toxin thioacetamide, and that thioacetamide-treated TLR4 knock-out mice exhibited a reduction in brain edema. These studies strongly suggest that ECs significantly contribute to the astrocyte swelling/brain edema in acute hepatic encephalopathy, likely as a consequence of increased TLR4 protein expression by blood-borne noxious agents.

  15. P2X7 receptor-deficient mice are susceptible to bone cancer pain

    DEFF Research Database (Denmark)

    Hansen, Rikke Rie; Nielsen, Christian K.; Nasser, Arafat;

    2011-01-01

    with and without astrocyte activation (BALB/cJ or C3H mice inoculated with 4T1 mammary cancer cells or NCTC 2472 osteosarcoma cells, respectively), suggesting that astrocytic P2X7 receptors play a negligible role in bone cancer pain. The results support the hypothesis that bone cancer pain is a separate pain state...

  16. PrP{sup C} displays an essential protective role from oxidative stress in an astrocyte cell line derived from PrP{sup C} knockout mice

    Energy Technology Data Exchange (ETDEWEB)

    Bertuchi, Fernanda R. [Center for Natural Sciences and Humanities, Federal University of ABC - UFABC, Avenida dos Estados, 5001, Bloco B, 09210-170, Santo Andre, SP (Brazil); Bourgeon, Dominique M.G.; Landemberger, Michele C.; Martins, Vilma R. [International Center for Research and Education, A.C. Camargo Hospital, Rua Tagua 440, 01505-010 Sao Paulo, SP (Brazil); Cerchiaro, Giselle, E-mail: giselle.cerchiaro@ufabc.edu.br [Center for Natural Sciences and Humanities, Federal University of ABC - UFABC, Avenida dos Estados, 5001, Bloco B, 09210-170, Santo Andre, SP (Brazil)

    2012-02-03

    Highlights: Black-Right-Pointing-Pointer PrP{sup C} in solution acts as a radical scavenger. Black-Right-Pointing-Pointer PrP{sup C} reduces hydrogen peroxide toxicity in astrocytes. Black-Right-Pointing-Pointer Increase in ROS disrupted the cell cycle in the PrP{sup C}-knockout astrocytes. Black-Right-Pointing-Pointer PrP{sup C} prevents the cell death independently of an SOD-like activity. -- Abstract: The PrP{sup C} protein, which is especially present in the cellular membrane of nervous system cells, has been extensively studied for its controversial antioxidant activity. In this study, we elucidated the free radical scavenger activity of purified murine PrP{sup C} in solution and its participation as a cell protector in astrocytes that were subjected to treatment with an oxidant. In vitro and using an EPR spin-trapping technique, we observed that PrP{sup C} decreased the oxidation of the DMPO trap in a Fenton reaction system (Cu{sup 2+}/ascorbate/H{sub 2}O{sub 2}), which was demonstrated by approximately 70% less DMPO/OH{sup {center_dot}}. In cultured PrP{sup C}-knockout astrocytes from mice, the absence of PrP{sup C} caused an increase in intracellular ROS (reactive oxygen species) generation during the first 3 h of H{sub 2}O{sub 2} treatment. This rapid increase in ROS disrupted the cell cycle in the PrP{sup C}-knockout astrocytes, which increased the population of cells in the sub-G1 phase when compared with cultured wild-type astrocytes. We conclude that PrP{sup C} in solution acts as a radical scavenger, and in astrocytes, it is essential for protection from oxidative stress caused by an external chemical agent, which is a likely condition in human neurodegenerative CNS disorders and pathological conditions such as ischemia.

  17. Knockdown of astrocyte elevated gene-1 inhibits proliferation and enhancing chemo-sensitivity to cisplatin or doxorubicin in neuroblastoma cells

    Directory of Open Access Journals (Sweden)

    Xie Li

    2009-02-01

    Full Text Available Abstract Background Astrocyte elevated gene-1 (AEG-1 was originally characterized as a HIV-1-inducible gene in primary human fetal astrocyte. Recent studies highlight a potential role of AEG-1 in promoting tumor progression and metastasis. The aim of this study was to investigate if AEG-1 serves as a potential therapeutic target of human neuroblastoma. Methods We employed RNA interference to reduce AEG-1 expression in human neuroblastoma cell lines and analyzed their phenotypic changes. Results We found that the knockdown of AEG-1 expression in human neuroblastoma cells significantly inhibited cell proliferation and apoptosis. The specific downregulation induced cell arrest in the G0/G1 phase of cell cycle. In the present study, we also observed a significant enhancement of chemo-sensitivity to cisplatin and doxorubicin by knockdown of AEG-1. Conclusion Our study suggests that overexpressed AEG-1 enhance the tumorogenic properties of neuroblastoma cells. The inhibition of AEG-1 expression could be a new adjuvant therapy for neuroblastoma.

  18. Welcoming Treat: Astrocyte-Derived Exosomes Induce PTEN Suppression to Foster Brain Metastasis.

    Science.gov (United States)

    Alečković, Maša; Kang, Yibin

    2015-11-09

    Metastasis to distant organs depends on pathological crosstalk between tumor cells and various tissue-specific stromal components. Zhang and colleagues recently demonstrated that astrocyte-derived exosomal miR-19a reversibly downregulated PTEN expression in cancer cells, thereby increasing their CCL2 secretion and recruitment of myeloid cell to promote brain metastasis.

  19. PUMA is invovled in ischemia/reperfusion-induced apoptosis of mouse cerebral astrocytes.

    Science.gov (United States)

    Chen, H; Tian, M; Jin, L; Jia, H; Jin, Y

    2015-01-22

    PUMA (p53-upregulated modulator of apoptosis), a BH3-only member of the Bcl-2 protein family, is required for p53-dependent and p53-independent forms of apoptosis. PUMA has been invovled in the onset and progress of several diseases, including cancer, acquired immunodeficiency syndrome, and ischemic brain disease. Although many studies have shown that ischemia and reperfusion (I/R) can induce the apoptosis of astrocytes, the role of PUMA in I/R-mediated apoptosis of cerebral astrocyte apoptosis remains unclear. To mimic in vivo I/R conditions, primary mouse cerebral astrocytes were incubated in a combinational cultural condition of oxygen, glucose, and serum deprivation (OSGD) for 1 h followed by reperfusion (OSGD/R). Cell death determination assays and cell viability assays indicated that OSGD and OSGD/R induce the apoptosis of primary cerebral astrocytes. The expression of PUMA was significantly elevated in primary cerebral astrocytes during OSGD/R. Moreover, targeted down-regulation of PUMA by siRNA transfection significantly decreased the OSGD/R-induced apoptosis of primary cerebral astrocytes. We also found that OSGD and OSGD/R triggered the release of cytochrome c in astrocytes, indicating the dependence on a mitochondrial apoptotic pathway. Reactive oxygen species (ROS) was extremely generated during OSGD and OSGD/R, and the elimination of ROS by treated with N-acetyl-L-cysteine (NAC) remarkably inhibited the expression of PUMA and the apoptosis of primary cerebral astrocytes. The activation of Caspase 3 and Caspase 9 was extremely elevated in primary cerebral astrocytes during OSGD. In addition, we found that knockdown of PUMA led to the depressed expression of Bax, cleaved caspase-9 and caspase-3 during OSGD/R. These results indicate that PUMA is invovled in the apoptosis of cerebral astrocytes upon I/R injury.

  20. Effects of folic acid on in vitro astrocytic differentiation of neural stem cells from neonatal rats

    Institute of Scientific and Technical Information of China (English)

    Xumei Zhang; Guowei Huang; Zhihong Tian; Guanglei Wang; Dalin Ren

    2009-01-01

    ary acidic protein/BrdU-positive ceils (P<0.05), and significantly decreased Ngn1 protein expression (P<0.05).CONCLUSION: Folic acid promotes astrocytic differentiation of NSCs, which might be related to downregulation of Ngnl protein expression.

  1. Activation of the intrinsic cell death pathway, increased apoptosis and modulation of astrocytes in the cerebellum of diabetic rats.

    Science.gov (United States)

    Lechuga-Sancho, Alfonso M; Arroba, Ana I; Frago, Laura M; Pañeda, Covadonga; García-Cáceres, Cristina; Delgado Rubín de Célix, Arancha; Argente, Jesús; Chowen, Julie A

    2006-08-01

    Poorly controlled diabetes mellitus results in structural and functional changes in many brain regions. We demonstrate that in streptozotocin-induced diabetic rats cell death is increased and proliferation decreased in the cerebellum, indicating overall cell loss. Levels of both the proform and cleaved forms of caspases 3, 6 and 9 are increased, with no change in caspases 7, 8 or 12. Colocalization of glial fibrillary acidic protein (GFAP) and cleaved caspase 3 and GFAP in TUNEL-positive cells increased in diabetic rats. Changes in GFAP levels paralleled modifications in proliferating cell nuclear antigen (PCNA), increasing at 1 week of diabetes and decreasing thereafter, and proliferating GFAP-positive cells were decreased in the cerebellum of diabetic rats. These results suggest that astrocytes are dramatically affected in the cerebellum, including an increase in cell death and a decrease in proliferation, and this could play a role in the structural and functional changes in this brain area in diabetes.

  2. Why are astrocytes important?

    Science.gov (United States)

    Verkhratsky, Alexei; Nedergaard, Maiken; Hertz, Leif

    2015-02-01

    Astrocytes, which populate the grey and white mater of the brain and the spinal cord are highly heterogeneous in their morphology and function. These cells are primarily responsible for homeostasis of the central nervous system (CNS). Most central synapses are surrounded by exceedingly thin astroglial perisynaptic processes, which act as "astroglial cradle" critical for genesis, maturation and maintenance of synaptic connectivity. The perisynaptic glial processes are densely packed with numerous transporters, which provide for homeostasis of ions and neurotransmitters in the synaptic cleft, for local metabolic support and for release of astroglial derived scavengers of reactive oxygen species. Through perivascular processes astrocytes contribute to blood-brain barrier and form "glymphatic" drainage system of the CNS. Furthermore astrocytes are indispensible for glutamatergic and γ-aminobutyrate-ergic synaptic transmission being the supplier of neurotransmitters precursor glutamine via an astrocytic/neuronal cycle. Pathogenesis of many neurological disorders, including neuropsychiatric and neurodegenerative diseases is defined by loss of homeostatic function (astroglial asthenia) or remodelling of astroglial homoeostatic capabilities. Astroglial cells further contribute to neuropathologies through mounting complex defensive programme generally known as reactive astrogliosis.

  3. Ornithine and Homocitrulline Impair Mitochondrial Function, Decrease Antioxidant Defenses and Induce Cell Death in Menadione-Stressed Rat Cortical Astrocytes: Potential Mechanisms of Neurological Dysfunction in HHH Syndrome.

    Science.gov (United States)

    Zanatta, Ângela; Rodrigues, Marília Danyelle Nunes; Amaral, Alexandre Umpierrez; Souza, Débora Guerini; Quincozes-Santos, André; Wajner, Moacir

    2016-09-01

    Hyperornithinemia-hyperammonemia-homocitrullinuria (HHH) syndrome is caused by deficiency of ornithine translocase leading to predominant tissue accumulation and high urinary excretion of ornithine (Orn), homocitrulline (Hcit) and ammonia. Although affected patients commonly present neurological dysfunction manifested by cognitive deficit, spastic paraplegia, pyramidal and extrapyramidal signs, stroke-like episodes, hypotonia and ataxia, its pathogenesis is still poorly known. Although astrocytes are necessary for neuronal protection. Therefore, in the present study we investigated the effects of Orn and Hcit on cell viability (propidium iodide incorporation), mitochondrial function (thiazolyl blue tetrazolium bromide-MTT-reduction and mitochondrial membrane potential-ΔΨm), antioxidant defenses (GSH) and pro-inflammatory response (NFkB, IL-1β, IL-6 and TNF-α) in unstimulated and menadione-stressed cortical astrocytes that were previously shown to be susceptible to damage by neurotoxins. We first observed that Orn decreased MTT reduction, whereas both amino acids decreased GSH levels, without altering cell viability and the pro-inflammatory factors in unstimulated astrocytes. Furthermore, Orn and Hcit decreased cell viability and ΔΨm in menadione-treated astrocytes. The present data indicate that the major compounds accumulating in HHH syndrome impair mitochondrial function and reduce cell viability and the antioxidant defenses in cultured astrocytes especially when stressed by menadione. It is presumed that these mechanisms may be involved in the neuropathology of this disease.

  4. Serpins promote cancer cell survival and vascular co-option in brain metastasis.

    Science.gov (United States)

    Valiente, Manuel; Obenauf, Anna C; Jin, Xin; Chen, Qing; Zhang, Xiang H-F; Lee, Derek J; Chaft, Jamie E; Kris, Mark G; Huse, Jason T; Brogi, Edi; Massagué, Joan

    2014-02-27

    Brain metastasis is an ominous complication of cancer, yet most cancer cells that infiltrate the brain die of unknown causes. Here, we identify plasmin from the reactive brain stroma as a defense against metastatic invasion, and plasminogen activator (PA) inhibitory serpins in cancer cells as a shield against this defense. Plasmin suppresses brain metastasis in two ways: by converting membrane-bound astrocytic FasL into a paracrine death signal for cancer cells, and by inactivating the axon pathfinding molecule L1CAM, which metastatic cells express for spreading along brain capillaries and for metastatic outgrowth. Brain metastatic cells from lung cancer and breast cancer express high levels of anti-PA serpins, including neuroserpin and serpin B2, to prevent plasmin generation and its metastasis-suppressive effects. By protecting cancer cells from death signals and fostering vascular co-option, anti-PA serpins provide a unifying mechanism for the initiation of brain metastasis in lung and breast cancers.

  5. A “Hit and Run” Approach to Inducible Direct Reprogramming of Astrocytes to Neural Stem Cells

    Science.gov (United States)

    Poulou, Maria; Mandalos, Nikolaos P.; Karnavas, Theodoros; Saridaki, Marannia; McKay, Ronald D. G.; Remboutsika, Eumorphia

    2016-01-01

    Temporal and spatial control of gene expression can be achieved using an inducible system as a fundamental tool for regulated transcription in basic, applied and eventually in clinical research. We describe a novel “hit and run” inducible direct reprogramming approach. In a single step, 2 days post-transfection, transiently transfected Sox2FLAG under the Leu3p-αIPM inducible control (iSox2) triggers the activation of endogenous Sox2, redirecting primary astrocytes into abundant distinct nestin-positive radial glia cells. This technique introduces a unique novel tool for safe, rapid and efficient reprogramming amendable to regenerative medicine. PMID:27148066

  6. Id4 and FABP7 are preferentially expressed in cells with astrocytic features in oligodendrogliomas and oligoastrocytomas

    Directory of Open Access Journals (Sweden)

    Nicholas M Kelly

    2005-07-01

    Full Text Available Abstract Background Oligodendroglioma (ODG and oligoastrocytoma (OAC are diffusely infiltrating primary brain tumors whose pathogenesis remains unclear. We previously identified a group of genes whose expression was inversely correlated with survival in a cohort of patients with glioblastoma (GBM, and some of these genes are also reportedly expressed in ODG and OAC. We examined the expression patterns and localization of these survival-associated genes in ODG and OAC in order to analyze their possible roles in the oncogenesis of these two tumor types. Methods We used UniGene libraries derived from GBM and ODG specimens to examine the expression levels of the transcripts for each of the 50 GBM survival-associated genes. We used immunohistochemistry and cDNA microarrays to examine expression of selected survival-associated genes and Id4, a gene believed to control the timing of oligodendrocyte development. The expression of FABP7 and Id4 and the survival of patients with ODG and OAC were also analyzed. Results Transcripts of most survival-associated genes as well as Id4 were present in both GBM and ODG tumors, whereas protein expression of Id4 and one of the survival-associated genes, brain-type fatty acid-binding protein (FABP7, was present in cells with astrocytic features, including reactive and neoplastic astrocytes, but not in neoplastic oligodendrocytes. Id4 was co-expressed with FABP7 in microgemistocytes in ODG and in neoplastic astrocytes in OAC. Id4 and FABP7 expression, however, did not correlate with the clinical outcome of patients with ODG or OAC tumors. Conclusion Expression of Id4 and some of our previously identified GBM survival-associated genes is present in developing or mature oligodendrocytes. However, protein expression of Id4 and FABP7 in GBM, ODG, and OAC suggests that this group of functionally important genes might demonstrate two patterns of expression in these glioma subtypes: one group is universally expressed in

  7. Connexin43 recruits PTEN and Csk to inhibit c-Src activity in glioma cells and astrocytes

    Science.gov (United States)

    González-Sánchez, Ana; Jaraíz-Rodríguez, Myriam; Domínguez-Prieto, Marta; Herrero-González, Sandra; Medina, José M.; Tabernero, Arantxa

    2016-01-01

    Connexin43 (Cx43), the major protein forming gap junctions in astrocytes, is reduced in high-grade gliomas, where its ectopic expression exerts important effects, including the inhibition of the proto-oncogene tyrosine-protein kinase Src (c-Src). In this work we aimed to investigate the mechanism responsible for this effect. The inhibition of c-Src requires phosphorylation at tyrosine 527 mediated by C-terminal Src kinase (Csk) and dephosphorylation at tyrosine 416 mediated by phosphatases, such as phosphatase and tensin homolog (PTEN). Our results showed that the antiproliferative effect of Cx43 is reduced when Csk and PTEN are silenced in glioma cells, suggesting the involvement of both enzymes. Confocal microscopy and immunoprecipitation assays confirmed that Cx43, in addition to c-Src, binds to PTEN and Csk in glioma cells transfected with Cx43 and in astrocytes. Pull-down assays showed that region 266–283 in Cx43 is sufficient to recruit c-Src, PTEN and Csk and to inhibit the oncogenic activity of c-Src. As a result of c-Src inhibition, PTEN was increased with subsequent inactivation of Akt and reduction of proliferation of human glioblastoma stem cells. We conclude that the recruitment of Csk and PTEN to the region between residues 266 and 283 within the C-terminus of Cx43 leads to c-Src inhibition. PMID:27391443

  8. Preclinical Studies of Induced Pluripotent Stem Cell-Derived Astrocyte Transplantation in ALS

    Science.gov (United States)

    2014-12-01

    a second trial testing transplantation of hESC-derived retinal pigment epithelium for macular degeneration has reported no safety concerns involving...ALS Association Investigator Meeting. Investigating Astrocyte-Mediated Degeneration of Upper Motor Neurons in ALS. Philadelphia, PA, USA 10/24/14...evident that aDepartment of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; bDepartments of Rehabilitation and

  9. Dynamic reactive astrocytes after focal ischemia

    Institute of Scientific and Technical Information of China (English)

    Shinghua Ding

    2014-01-01

    Astrocytes are specialized and most numerous glial cell type in the central nervous system and play important roles in physiology. Astrocytes are also critically involved in many neural disor-ders including focal ischemic stroke, a leading cause of brain injury and human death. One of the prominent pathological features of focal ischemic stroke is reactive astrogliosis and glial scar for-mation associated with morphological changes and proliferation. This review paper discusses the recent advances in spatial and temporal dynamics of morphology and proliferation of reactive astrocytes after ischemic stroke based on results from experimental animal studies. As reactive astrocytes exhibit stem cell-like properties, knowledge of dynamics of reactive astrocytes and glial scar formation will provide important insights for astrocyte-based cell therapy in stroke.

  10. Light and electron microscopic localization of GABAA-receptors on cultured cerebellar granule cells and astrocytes using immunohistochemical techniques

    DEFF Research Database (Denmark)

    Hansen, Gert Helge; Hösli, E; Belhage, B;

    1991-01-01

    . At the light microscope level specific staining of GABAA-receptors was localized in various types of neurones in explant cultures of rat cerebellum using the indirect peroxidase-antiperoxidase (PAP) technique, whereas no specific staining was found in astrocytes. At the electron microscope level labeling...... of GABAA-receptors was observed in the plasma membrane of both the cell bodies and processes in dissociated primary cultures of cerebellar granule cells using an indirect preembedding immunogold staining technique which in contrast to the classical PAP technique allows quantitative estimations...... to be performed. Quantification of the labeling intensity revealed a higher concentration of GABAA-receptors per microns plasma membrane in the cell bodies than in the processes. In discrete areas an extremely high density of the GABAA-receptors was observed. No specific labeling of GABAA-receptors was observed...

  11. Increasing tPA activity in astrocytes induced by multipotent mesenchymal stromal cells facilitate neurite outgrowth after stroke in the mouse.

    Directory of Open Access Journals (Sweden)

    Hongqi Xin

    Full Text Available We demonstrate that tissue plasminogen activator (tPA and its inhibitors contribute to neurite outgrowth in the central nervous system (CNS after treatment of stroke with multipotent mesenchymal stromal cells (MSCs. In vivo, administration of MSCs to mice subjected to middle cerebral artery occlusion (MCAo significantly increased activation of tPA and downregulated PAI-1 levels in the ischemic boundary zone (IBZ compared with control PBS treated mice, concurrently with increases of myelinated axons and synaptophysin. In vitro, MSCs significantly increased tPA levels and concomitantly reduced plasminogen activator inhibitor 1 (PAI-1 expression in astrocytes under normal and oxygen and glucose deprivation (OGD conditions. ELISA analysis of conditioned medium revealed that MSCs stimulated astrocytes to secrete tPA. When primary cortical neurons were cultured in the conditioned medium from MSC co-cultured astrocytes, these neurons exhibited a significant increase in neurite outgrowth compared to conditioned medium from astrocytes alone. Blockage of tPA with a neutralizing antibody or knock-down of tPA with siRNA significantly attenuated the effect of the conditioned medium on neurite outgrowth. Addition of recombinant human tPA into cortical neuronal cultures also substantially enhanced neurite outgrowth. Collectively, these in vivo and in vitro data suggest that the MSC mediated increased activation of tPA in astrocytes promotes neurite outgrowth after stroke.

  12. Sphingosine 1 Phosphate at the Blood Brain Barrier: Can the Modulation of S1P Receptor 1 Influence the Response of Endothelial Cells and Astrocytes to Inflammatory Stimuli?

    Directory of Open Access Journals (Sweden)

    Simona F Spampinato

    Full Text Available The ability of the Blood Brain Barrier (BBB to maintain proper barrier functions, keeping an optimal environment for central nervous system (CNS activity and regulating leukocytes' access, can be affected in CNS diseases. Endothelial cells and astrocytes are the principal BBB cellular constituents and their interaction is essential to maintain its function. Both endothelial cells and astrocytes express the receptors for the bioactive sphingolipid S1P. Fingolimod, an immune modulatory drug whose structure is similar to S1P, has been approved for treatment in multiple sclerosis (MS: fingolimod reduces the rate of MS relapses by preventing leukocyte egress from the lymph nodes. Here, we examined the ability of S1P and fingolimod to act on the BBB, using an in vitro co-culture model that allowed us to investigate the effects of S1P on endothelial cells, astrocytes, and interactions between the two. Acting selectively on endothelial cells, S1P receptor signaling reduced cell death induced by inflammatory cytokines. When acting on astrocytes, fingolimod treatment induced the release of a factor, granulocyte macrophage colony-stimulating factor (GM-CSF that reduced the effects of cytokines on endothelium. In an in vitro BBB model incorporating shear stress, S1P receptor modulation reduced leukocyte migration across the endothelial barrier, indicating a novel mechanism that might contribute to fingolimod efficacy in MS treatment.

  13. Adenosine Receptors Differentially Regulate the Expression of Regulators of G-Protein Signalling (RGS 2, 3 and 4 in Astrocyte-Like Cells.

    Directory of Open Access Journals (Sweden)

    Till Nicolas Eusemann

    Full Text Available The "regulators of g-protein signalling" (RGS comprise a large family of proteins that limit by virtue of their GTPase accelerating protein domain the signal transduction of G-protein coupled receptors. RGS proteins have been implicated in various neuropsychiatric diseases such as schizophrenia, drug abuse, depression and anxiety and aggressive behaviour. Since conditions associated with a large increase of adenosine in the brain such as seizures or ischemia were reported to modify the expression of some RGS proteins we hypothesized that adenosine might regulate RGS expression in neural cells. We measured the expression of RGS-2,-3, and -4 in both transformed glia cells (human U373 MG astrocytoma cells and in primary rat astrocyte cultures stimulated with adenosine agonists. Expression of RGS-2 mRNA as well as RGS2 protein was increased up to 30-fold by adenosine agonists in astrocytes. The order of potency of agonists and the blockade by the adenosine A2B-antagonist MRS1706 indicated that this effect was largely mediated by adenosine A2B receptors. However, a smaller effect was observed due to activation of adenosine A2A receptors. In astrocytoma cells adenosine agonists elicited an increase in RGS-2 expression solely mediated by A2B receptors. Expression of RGS-3 was inhibited by adenosine agonists in both astrocytoma cells and astrocytes. However while this effect was mediated by A2B receptors in astrocytoma cells it was mediated by A2A receptors in astrocytes as assessed by the order of potency of agonists and selective blockade by the specific antagonists MRS1706 and ZM241385 respectively. RGS-4 expression was inhibited in astrocytoma cells but enhanced in astrocytes by adenosine agonists.

  14. Identification of soluble CD14 as an endogenous agonist for toll-like receptor 2 on human astrocytes by genome-scale functional screening of glial cell derived proteins

    NARCIS (Netherlands)

    Bsibsi, M.; Bajramovic, J.J.; Duijvenvoorden, E. van; Persoon, C.; Ravid, R.; Noort, J.M. van; Vogt, M.H.J.

    2007-01-01

    Human astrocytes express a limited repertoire of Toll-like receptor (TLR) family members including TLR1-4, which are expressed on the cell surface. Also, TLR3 but not TLR4 activation on astrocytes induces expression of several factors involved in neuroprotection and down-regulation of inflammation r

  15. Development of a method for the purification and culture of rodent astrocytes.

    Science.gov (United States)

    Foo, Lynette C; Allen, Nicola J; Bushong, Eric A; Ventura, P Britten; Chung, Won-Suk; Zhou, Lu; Cahoy, John D; Daneman, Richard; Zong, Hui; Ellisman, Mark H; Barres, Ben A

    2011-09-08

    The inability to purify and culture astrocytes has long hindered studies of their function. Whereas astrocyte progenitor cells can be cultured from neonatal brain, culture of mature astrocytes from postnatal brain has not been possible. Here, we report a new method to prospectively purify astrocytes by immunopanning. These astrocytes undergo apoptosis in culture, but vascular cells and HBEGF promote their survival in serum-free culture. We found that some developing astrocytes normally undergo apoptosis in vivo and that the vast majority of astrocytes contact blood vessels, suggesting that astrocytes are matched to blood vessels by competing for vascular-derived trophic factors such as HBEGF. Compared to traditional astrocyte cultures, the gene profiles of the cultured purified postnatal astrocytes much more closely resemble those of in vivo astrocytes. Although these astrocytes strongly promote synapse formation and function, they do not secrete glutamate in response to stimulation.

  16. Primary cultures of astrocytes

    DEFF Research Database (Denmark)

    Lange, Sofie C; Bak, Lasse Kristoffer; Waagepetersen, Helle S;

    2012-01-01

    During the past few decades of astrocyte research it has become increasingly clear that astrocytes have taken a central position in all central nervous system activities. Much of our new understanding of astrocytes has been derived from studies conducted with primary cultures of astrocytes. Such ...

  17. Redefining the concept of reactive astrocytes as cells that remain within their unique domains upon reaction to injury

    OpenAIRE

    2006-01-01

    Reactive astrocytes in neurotrauma, stroke, or neurodegeneration are thought to undergo cellular hypertrophy, based on their morphological appearance revealed by immunohistochemical detection of glial fibrillary acidic protein, vimentin, or nestin, all of them forming intermediate filaments, a part of the cytoskeleton. Here, we used a recently established dye-filling method to reveal the full three-dimensional shape of astrocytes assessing the morphology of reactive astrocytes in two neurotra...

  18. Inflammation and cancer stem cells.

    Science.gov (United States)

    Shigdar, Sarah; Li, Yong; Bhattacharya, Santanu; O'Connor, Michael; Pu, Chunwen; Lin, Jia; Wang, Tao; Xiang, Dongxi; Kong, Lingxue; Wei, Ming Q; Zhu, Yimin; Zhou, Shufeng; Duan, Wei

    2014-04-10

    Cancer stem cells are becoming recognised as being responsible for metastasis and treatment resistance. The complex cellular and molecular network that regulates cancer stem cells and the role that inflammation plays in cancer progression are slowly being elucidated. Cytokines, secreted by tumour associated immune cells, activate the necessary pathways required by cancer stem cells to facilitate cancer stem cells progressing through the epithelial-mesenchymal transition and migrating to distant sites. Once in situ, these cancer stem cells can secrete their own attractants, thus providing an environment whereby these cells can continue to propagate the tumour in a secondary niche.

  19. Cancer stem cells, cancer cell plasticity and radiation therapy.

    Science.gov (United States)

    Vlashi, Erina; Pajonk, Frank

    2015-04-01

    Since the first prospective identification of cancer stem cells in solid cancers the cancer stem cell hypothesis has reemerged as a research topic of increasing interest. It postulates that solid cancers are organized hierarchically with a small number of cancer stem cells driving tumor growth, repopulation after injury and metastasis. They give rise to differentiated progeny, which lack these features. The model predicts that for any therapy to provide cure, all cancer stem cells have to be eliminated while the survival of differentiated progeny is less critical. In this review we discuss recent reports challenging the idea of a unidirectional differentiation of cancer cells. These reports provide evidence supporting the idea that non-stem cancer cells exhibit a remarkable degree of plasticity that allows them to re-acquire cancer stem cell traits, especially in the context of radiation therapy. We summarize conditions under which differentiation is reversed and discuss the current knowledge of the underlying mechanisms.

  20. Molecular scaffolds underpinning macroglial polarization: an analysis of retinal Müller cells and brain astrocytes in mouse.

    Science.gov (United States)

    Enger, Rune; Gundersen, Georg Andreas; Haj-Yasein, Nadia Nabil; Eilert-Olsen, Martine; Thoren, Anna Elisabeth; Vindedal, Gry Fluge; Petersen, Pétur Henry; Skare, Øivind; Nedergaard, Maiken; Ottersen, Ole Petter; Nagelhus, Erlend A

    2012-12-01

    Key roles of macroglia are inextricably coupled to specialized membrane domains. The perivascular endfoot membrane has drawn particular attention, as this domain contains a unique complement of aquaporin-4 (AQP4) and other channel proteins that distinguishes it from perisynaptic membranes. Recent studies indicate that the polarization of macroglia is lost in a number of diseases, including temporal lobe epilepsy and Alzheimer's disease. A better understanding is required of the molecular underpinning of astroglial polarization, particularly when it comes to the significance of the dystrophin associated protein complex (DAPC). Here, we employ immunofluorescence and immunogold cytochemistry to analyze the molecular scaffolding in perivascular endfeet in macroglia of retina and three regions of brain (cortex, dentate gyrus, and cerebellum), using AQP4 as a marker. Compared with brain astrocytes, Müller cells (a class of retinal macroglia) exhibit lower densities of the scaffold proteins dystrophin and α-syntrophin (a DAPC protein), but higher levels of AQP4. In agreement, depletion of dystrophin or α-syntrophin--while causing a dramatic loss of AQP4 from endfoot membranes of brain astrocytes--had only modest or insignificant effect, respectively, on the AQP4 pool in endfoot membranes of Müller cells. In addition, while polarization of brain macroglia was less affected by dystrophin depletion than by targeted deletion of α-syntrophin, the reverse was true for retinal macroglia. These data indicate that the molecular scaffolding in perivascular endfeet is more complex than previously assumed and that macroglia are heterogeneous with respect to the mechanisms that dictate their polarization.

  1. A phosphatase-independent gain-of-function mutation in PTEN triggers aberrant cell growth in astrocytes through an autocrine IGF-1 loop.

    Science.gov (United States)

    Fernández, S; Genis, L; Torres-Alemán, I

    2014-08-07

    Loss-of-function mutations in the phosphatase PTEN (phosphatase and tensin homolog deleted on chromosome10) contribute to aberrant cell growth in part through upregulation of the mitogenic IGF-1/PI3K/Akt pathway. In turn, this pathway exerts a homeostatic feedback over PTEN. Using mutagenesis analysis to explore a possible impact of this mutual control on astrocyte growth, we found that truncation of the C-terminal region of PTEN (Δ51) associates with a marked increase in NFκB activity, a transcription factor overactivated in astrocyte tumors. Whereas mutations of PTEN are considered to lead to a loss-of-function, PTENΔ51, a truncation that comprises a region frequently mutated in human gliomas, displayed a neomorphic (gain-of-function) activity that was independent of its phosphatase activity. This gain-of-function of PTENΔ51 includes stimulation of IGF-1 synthesis through protein kinase A activation of the IGF-1 promoter. Increased IGF-1 originates an autocrine loop that activates Akt and NFκB. Constitutive activation of NFκB in PTENΔ51-expressing astrocytes leads to aberrant cell growth; astrocytes expressing this mutant PTEN generate colonies in vitro and tumors in vivo. Mutations converting a tumor suppressor such as PTEN into a tumor promoter through a gain-of-function involving IGF-1 production may further our understanding of the role played by this growth factor in glioma growth and help us define druggable targets for personalized therapy.

  2. The speed of swelling kinetics modulates cell volume regulation and calcium signaling in astrocytes: A different point of view on the role of aquaporins.

    Science.gov (United States)

    Mola, Maria Grazia; Sparaneo, Angelo; Gargano, Concetta Domenica; Spray, David C; Svelto, Maria; Frigeri, Antonio; Scemes, Eliana; Nicchia, Grazia Paola

    2016-01-01

    Regulatory volume decrease (RVD) is a process by which cells restore their original volume in response to swelling. In this study, we have focused on the role played by two different Aquaporins (AQPs), Aquaporin-4 (AQP4), and Aquaporin-1 (AQP1), in triggering RVD and in mediating calcium signaling in astrocytes under hypotonic stimulus. Using biophysical techniques to measure water flux through the plasma membrane of wild-type (WT) and AQP4 knockout (KO) astrocytes and of an astrocyte cell line (DI TNC1) transfected with AQP4 or AQP1, we here show that AQP-mediated fast swelling kinetics play a key role in triggering and accelerating RVD. Using calcium imaging, we show that AQP-mediated fast swelling kinetics also significantly increases the amplitude of calcium transients inhibited by Gadolinium and Ruthenium Red, two inhibitors of the transient receptor potential vanilloid 4 (TRPV4) channels, and prevented by removing extracellular calcium. Finally, inhibition of TRPV4 or removal of extracellular calcium does not affect RVD. All together our study provides evidence that (1) AQP influenced swelling kinetics is the main trigger for RVD and in mediating calcium signaling after hypotonic stimulus together with TRPV4, and (2) calcium influx from the extracellular space and/or TRPV4 are not essential for RVD to occur in astrocytes.

  3. Therapeutic potential of mesenchymal stromal cells and MSC conditioned medium in Amyotrophic Lateral Sclerosis (ALS--in vitro evidence from primary motor neuron cultures, NSC-34 cells, astrocytes and microglia.

    Directory of Open Access Journals (Sweden)

    Hui Sun

    Full Text Available Administration of mesenchymal stromal cells (MSC improves functional outcome in the SOD1G93A mouse model of the degenerative motor neuron disorder amyotrophic lateral sclerosis (ALS as well as in models of other neurological disorders. We have now investigated the effect of the interaction between MSC and motor neurons (derived from both non-transgenic and mutant SOD1G93A transgenic mice, NSC-34 cells and glial cells (astrocytes, microglia (derived again from both non-transgenic and mutant SOD1G93A ALS transgenic mice in vitro. In primary motor neurons, NSC-34 cells and astrocytes, MSC conditioned medium (MSC CM attenuated staurosporine (STS - induced apoptosis in a concentration-dependent manner. Studying MSC CM-induced expression of neurotrophic factors in astrocytes and NSC-34 cells, we found that glial cell line-derived neurotrophic factor (GDNF and ciliary neurotrophic factor (CNTF gene expression in astrocytes were significantly enhanced by MSC CM, with differential responses of non-transgenic and mutant astrocytes. Expression of Vascular Endothelial Growth Factor (VEGF in NSC-34 cells was significantly upregulated upon MSC CM-treatment. MSC CM significantly reduced the expression of the cytokines TNFα and IL-6 and iNOS both in transgenic and non-transgenic astrocytes. Gene expression of the neuroprotective chemokine Fractalkine (CX3CL1 was also upregulated in mutant SOD1G93A transgenic astrocytes by MSC CM treatment. Correspondingly, MSC CM increased the respective receptor, CX3CR1, in mutant SOD1G93A transgenic microglia. Our data demonstrate that MSC modulate motor neuronal and glial response to apoptosis and inflammation. MSC therefore represent an interesting candidate for further preclinical and clinical evaluation in ALS.

  4. Astrocyte, the star avatar: redefined

    Indian Academy of Sciences (India)

    Pankaj Seth; Nitin Koul

    2008-09-01

    Until recently, the neuroscience community held the belief that glial cells such as astrocytes and oligodendrocytes functioned solely as “support” cells of the brain. In this role, glial cells simply provide physical support and housekeeping functions for the more important cells of the brain, the neurons. However, this view has changed radically in recent years with the discovery of previously unrecognized and surprising functions for this underappreciated cell type. In the past decade or so, emerging evidence has provided new insights into novel glial cell activities such as control of synapse formation and function, communication, cerebrovascular tone regulation, immune regulation and adult neurogenesis. Such advances in knowledge have effectively elevated the role of the astrocyte to one that is more important than previously realized. This review summarizes the past and present knowledge of glial cell functions that has evolved over the years, and has resulted in a new appreciation of astrocytes and their value in studying the neurobiology of human brain cells and their functions. In this review, we highlight recent advances in the role of glial cells in physiology, pathophysiology and, most importantly, in adult neurogenesis and “stemness”, with special emphasis on astrocytes.

  5. Astrocyte loss and astrogliosis in neuroinflammatory disorders

    NARCIS (Netherlands)

    Hostenbach, Stephanie; Cambron, Melissa; D'haeseleer, Miguel; Kooijman, Ron; De Keyser, Jacques

    2014-01-01

    Neuroinflammation can lead to either damage of astrocytes or astrogliosis. Astrocyte loss may be caused by cytotoxic T cells as seen in Rasmussen encephalitis, auto-antibodies such as in neuromyelitis optica (aquaporin-4 antibodies), or cytokines such as TNF-alpha in major depressive disorder. Inter

  6. Relaxin protects astrocytes from hypoxia in vitro.

    Directory of Open Access Journals (Sweden)

    Jordan M Willcox

    Full Text Available The peptide relaxin has recently been shown to protect brain tissues from the detrimental effects of ischemia. To date, the mechanisms for this remain unclear. In order to investigate the neuroprotective mechanisms by which relaxin may protect the brain, we investigated the possibility that relaxin protects astrocytes from hypoxia or oxygen/glucose deprivation (OGD. Cultured astrocytes were pre-treated with either relaxin-2 or relaxin-3 and exposed to OGD for 24 or 48 hours. Following OGD exposure, viability assays showed that relaxin-treated cells exhibited a higher viability when compared to astrocytes that experienced OGD-alone. Next, to test whether relaxin reduced the production of reactive oxygen species (ROS astrocytes were exposed to the same conditions as the previous experiment and a commercially available ROS detection kit was used to detect ROS production. Astrocytes that were treated with relaxin-2 and relaxin-3 showed a marked decrease in ROS production when compared to control astrocytes that were exposed only to OGD. Finally, experiments were performed to determine whether or not the mitochondrial membrane potential was affected by relaxin treatment during 24 hour OGD. Mitochondrial membrane potential was higher in astrocytes that were treated with relaxin-2 and relaxin-3 compared to untreated OGD-alone astrocytes. Taken together, these data present novel findings that show relaxin protects astrocytes from ischemic conditions through the reduction of ROS production and the maintenance of mitochondrial membrane potential.

  7. Comparative effects on rat primary astrocytes and C6 rat glioma cells cultures after 24-h exposure to silver nanoparticles (AgNPs)

    Energy Technology Data Exchange (ETDEWEB)

    Salazar-García, Samuel; Silva-Ramírez, Ana Sonia; Ramirez-Lee, Manuel A.; Rosas-Hernandez, Hector [Universidad Autonoma de San Luis Potosi, Facultad de Ciencias Quimicas (Mexico); Rangel-López, Edgar [Instituto Nacional de Neurologia y Neurocirugia Manuel Velasco Suárez, Laboratorio de Aminoacidos Excitadores (Mexico); Castillo, Claudia G. [Facultad de Medicina, Universidad Autonoma de San Luis Potosi (Mexico); Santamaría, Abel [Instituto Nacional de Neurologia y Neurocirugia Manuel Velasco Suárez, Laboratorio de Aminoacidos Excitadores (Mexico); Martinez-Castañon, Gabriel A. [Universidad Autonoma de San Luis Potosi, Facultad de Estomatologia (Mexico); Gonzalez, Carmen, E-mail: cgonzalez.uaslp@gmail.com, E-mail: gonzalez.castillocarmen@fcq.uaslp.mx [Universidad Autonoma de San Luis Potosi, Facultad de Ciencias Quimicas (Mexico)

    2015-11-15

    The aim of this work was to compare the effects of 24-h exposure of rat primary astrocytes and C6 rat glioma cells to 7.8 nm AgNPs. Glioblastoma multiforme (GBM) is the most aggressive primary brain tumor and current treatments lead to diverse side-effects; for this reason, it is imperative to investigate new approaches, including those alternatives provided by nanotechnology, like nanomaterials (NMs) such as silver nanoparticles. Herein, we found that C6 rat glioma cells, but no primary astrocytes, decreased cell viability after AgNPs treatment; however, both cell types diminished their proliferation. The decrease of glioma C6 cells proliferation was related with necrosis, while in primary astrocytes, the decreased proliferation was associated with the induction of apoptosis. The ionic control (AgNO{sub 3}) exerted a different profile than AgNPs; the bulk form did not modify the basal effect in each determination, whereas cisplatin, a well-known antitumoral drug used as a comparative control, promoted cytotoxicity in both cell types at specific concentrations. Our findings prompt the need to determine the fine molecular and cellular mechanisms involved in the differential biological responses to AgNPs in order to develop new tools or alternatives based on nanotechnology that may contribute to the understanding, impact and use of NMs in specific targets, like glioblastoma cells.

  8. Cell-type-specific expression and regulation of a c-fos-NGF fusion gene in neurons and astrocytes of transgenic mice.

    Science.gov (United States)

    Onténiente, B; Horellou, P; Neveu, I; Makeh, I; Suzuki, F; Bourdet, C; Grimber, G; Colin, P; Brachet, P; Mallet, J

    1994-02-01

    A mouse line transgenic for nerve growth factor (NGF) was developed using the mouse prepro-NGF cDNA inserted within a plasmid containing the proximal region (-10 to -550 bp) of the c-fos promoter and the transcription termination and polyadenylation signals of the rabbit beta-globin gene. No significant modification of gross behavior or central nervous system anatomy was detected in adult animals as assessed by immunohistochemistry and in situ hybridization for NGF and choline acetyltransferase. The expression of the transgene and the possible regulation of its expression by agents acting on the promoter were investigated in vitro. Despite the presence of an additional pool of NGF mRNA specific to the transgene, basal levels of NGF in the supernatant of transgenic astrocytes were similar to normal ones. On the other hand, transgenic neurons spontaneously synthesized and released levels of NGF two to three times higher than normal neurons, while mRNA levels were barely detectable by conventional Northern blotting. The tissue-specificity of NGF expression was respected, with higher levels in hippocampal than neocortical neurons. Increases of NGF mRNA by agents acting on the promoter could be observed in normal and transgenic astrocytes only after inhibition of the protein synthesis by cycloheximide, suggesting a similar rapid turnover of normal and transgenic transcripts. Cyclic AMP agonists specifically increased the secretion of NGF protein by transgenic astrocytes and neurons, while activators of the protein kinase C had a similar effect on transgenic and normal cells. Differences between amounts of NGF secreted by neurons and astrocytes with regards to their respective content in mRNA suggest that transgenic transcripts are subject to normal cell- and tissue-specific post-transcriptional regulations. Agents acting on the c-fos promoter through the protein kinase C or cyclic AMP routes differentially increased the secretion of NGF by transgenic astrocytes or

  9. Effects of intrathecal injection of glial cell inhibitor on spinal cord astrocytes following chronic compression of dorsal root ganglia in rats

    Institute of Scientific and Technical Information of China (English)

    Xianhong Zhang; Wen Shen; Mingde Wang; Yinming Zeng

    2009-01-01

    obtained to count astrocytes under an inverted microscope. RESULTS: No significant differences in astrocyte count were detected between the fluorocitrate and model groups. Cell bodies were small with a few processes in the fluorocitrate group, compared with the model group. The astrocyte count decreased significantly in the minocycline group and the minocycline and fluorocitrate group compared with the sham operation, model, PBS and fluorocitrate groups (P < 0.01). The decrease in astrocyte count was mainly found in layers Ⅲ-Ⅳ of the spinal dorsal horn. Cell body volume was smaller and process numbers were fewer in the minocycline group and the minocycline and fluorocitrate group, compared with the model and PBS groups. CONCLUSION: Fluorocitrate can inhibit astrocyte activation, but does not affect astrocyte proliferation. However, minocycline can inhibit the activation and proliferation of astrocytes.

  10. BMPs as Therapeutic Targets and Biomarkers in Astrocytic Glioma

    Directory of Open Access Journals (Sweden)

    Pilar González-Gómez

    2014-01-01

    Full Text Available Astrocytic glioma is the most common brain tumor. The glioma initiating cell (GIC fraction of the tumor is considered as highly chemoresistant, suggesting that GICs are responsible for glioma relapse. A potential treatment for glioma is to induce differentiation of GICs to a more benign and/or druggable cell type. Given BMPs are among the most potent inducers of GIC differentiation, they have been considered as noncytotoxic therapeutic compounds that may be of use to prevent growth and recurrence of glioma. We herein summarize advances made in the understanding of the role of BMP signaling in astrocytic glioma, with a particular emphasis on the effects exerted on GICs. We discuss the prognostic value of BMP signaling components and the implications of BMPs in the differentiation of GICs and in their sensitization to alkylating drugs and oncolytic therapy/chemotherapy. This mechanistic insight may provide new opportunities for therapeutic intervention of brain cancer.

  11. Profilin isoforms modulate astrocytic morphology and the motility of astrocytic processes.

    Directory of Open Access Journals (Sweden)

    Stefanie K Schweinhuber

    Full Text Available The morphology of astrocytic processes determines their close structural association with synapses referred to as the 'tripartite synapse'. Concerted morphological plasticity processes at tripartite synapses are supposed to shape neuronal communication. Morphological changes in astrocytes as well as the motility of astrocytic processes require remodeling of the actin cytoskeleton. Among the regulators of fast timescale actin-based motility, the actin binding protein profilin 1 has recently been shown to control the activity-dependent outgrowth of astrocytic processes. Here, we demonstrate that cultured murine astrocytes in addition to the ubiquitous profilin 1 also express the neuronal isoform profilin 2a. To analyze the cellular function of both profilins in astrocytes, we took advantage of a shRNA mediated isoform-specific downregulation. Interestingly, consistent with earlier results in neurons, we found redundant as well as isoform-specific functions of both profilins in modulating cellular physiology. The knockdown of either profilin 1 or profilin 2a led to a significant decrease in cell spreading of astrocytes. In contrast, solely the knockdown of profilin 2a resulted in a significantly reduced morphological complexity of astrocytes in both dissociated and slice culture astrocytes. Moreover, both isoforms proved to be crucial for forskolin-induced astrocytic stellation. Furthermore, forskolin treatment resulted in isoform-specific changes in the phosphorylation level of profilin 1 and profilin 2a, leading to a PKA-dependent phosphorylation of profilin 2a. In addition, transwell assays revealed an involvement of both isoforms in the motility of astrocytic processes, while FRAP analysis displayed an isoform-specific role of profilin 1 in the regulation of actin dynamics in peripheral astrocytic processes. Taken together, we suggest profilin isoforms to be important modulators of astrocytic morphology and motility with overlapping as well as

  12. Effects of triptolide on hippocampal microglial cells and astrocytes in the APP/PS1 double transgenic mouse model of Alzheimer’s disease

    Institute of Scientific and Technical Information of China (English)

    Jian-ming Li; Yan Zhang; Liang Tang; Yong-heng Chen; Qian Gao; Mei-hua Bao; Ju Xiang; De-liang Lei

    2016-01-01

    The principal pathology of Alzheimer’s disease includes neuronal extracellular deposition of amyloid-beta peptides and formation of senile pl aques, which in turn induce neuroinlfammation in the brain. Triptolide, a natural extract from the vine-like herb Tripterygium wilfordiiHook F, has potent anti-inlfammatory and immunosuppressive efifcacy. Therefore, we determined if triptolide can inhibit activation and proliferation of microglial cells and astrocytes in the APP/PS1 double transgenic mouse model of Alzheimer’s disease. We used 1 or 5 μg/kg/d triptolide to treat APP/PS1 double transgenic mice (aged 4–4.5 months) for 45 days. Unbiased stereology analysis found that triptolide dose-dependent-ly reduced the total number of microglial cells, and transformed microglial cells into the resting state. Further, triptolide (5 μg/kg/d) also reduced the total number of hippocampal astrocytes. Our in vivo test results indicate that triptolide suppresses activation and proliferation of microglial cells and astrocytes in the hippocampus of APP/PS1 double transgenic mice with Alzheimer’s disease.

  13. Neuron-glia interactions through the Heartless FGF receptor signaling pathway mediate morphogenesis of Drosophila astrocytes.

    Science.gov (United States)

    Stork, Tobias; Sheehan, Amy; Tasdemir-Yilmaz, Ozge E; Freeman, Marc R

    2014-07-16

    Astrocytes are critically important for neuronal circuit assembly and function. Mammalian protoplasmic astrocytes develop a dense ramified meshwork of cellular processes to form intimate contacts with neuronal cell bodies, neurites, and synapses. This close neuron-glia morphological relationship is essential for astrocyte function, but it remains unclear how astrocytes establish their intricate morphology, organize spatial domains, and associate with neurons and synapses in vivo. Here we characterize a Drosophila glial subtype that shows striking morphological and functional similarities to mammalian astrocytes. We demonstrate that the Fibroblast growth factor (FGF) receptor Heartless autonomously controls astrocyte membrane growth, and the FGFs Pyramus and Thisbe direct astrocyte processes to ramify specifically in CNS synaptic regions. We further show that the shape and size of individual astrocytes are dynamically sculpted through inhibitory or competitive astrocyte-astrocyte interactions and Heartless FGF signaling. Our data identify FGF signaling through Heartless as a key regulator of astrocyte morphological elaboration in vivo.

  14. Differentiation-Dependent Energy Production and Metabolite Utilization: A Comparative Study on Neural Stem Cells, Neurons, and Astrocytes

    Science.gov (United States)

    Jády, Attila Gy.; Nagy, Ádám M.; Kőhidi, Tímea; Ferenczi, Szilamér; Tretter, László

    2016-01-01

    While it is evident that the metabolic machinery of stem cells should be fairly different from that of differentiated neurons, the basic energy production pathways in neural stem cells (NSCs) or in neurons are far from clear. Using the model of in vitro neuron production by NE-4C NSCs, this study focused on the metabolic changes taking place during the in vitro neuronal differentiation. O2 consumption, H+ production, and metabolic responses to single metabolites were measured in cultures of NSCs and in their neuronal derivatives, as well as in primary neuronal and astroglial cultures. In metabolite-free solutions, NSCs consumed little O2 and displayed a higher level of mitochondrial proton leak than neurons. In stem cells, glycolysis was the main source of energy for the survival of a 2.5-h period of metabolite deprivation. In contrast, stem cell-derived or primary neurons sustained a high-level oxidative phosphorylation during metabolite deprivation, indicating the consumption of own cellular material for energy production. The stem cells increased O2 consumption and mitochondrial ATP production in response to single metabolites (with the exception of glucose), showing rapid adaptation of the metabolic machinery to the available resources. In contrast, single metabolites did not increase the O2 consumption of neurons or astrocytes. In “starving” neurons, neither lactate nor pyruvate was utilized for mitochondrial ATP production. Gene expression studies also suggested that aerobic glycolysis and rapid metabolic adaptation characterize the NE-4C NSCs, while autophagy and alternative glucose utilization play important roles in the metabolism of stem cell-derived neurons. PMID:27116891

  15. Cancer stem cells and personalized cancer nanomedicine.

    Science.gov (United States)

    Gener, Petra; Rafael, Diana Fernandes de Sousa; Fernández, Yolanda; Ortega, Joan Sayós; Arango, Diego; Abasolo, Ibane; Videira, Mafalda; Schwartz, Simo

    2016-02-01

    Despite the progress in cancer treatment over the past years advanced cancer is still an incurable disease. Special attention is pointed toward cancer stem cell (CSC)-targeted therapies, because this minor cell population is responsible for the treatment resistance, metastatic growth and tumor recurrence. The recently described CSC dynamic phenotype and interconversion model of cancer growth hamper even more the possible success of current cancer treatments in advanced cancer stages. Accordingly, CSCs can be generated through dedifferentiation processes from non-CSCs, in particular, when CSC populations are depleted after treatment. In this context, the use of targeted CSC nanomedicines should be considered as a promising tool to increase CSC sensitivity and efficacy of specific anti-CSC therapies.

  16. In situ probing of cholesterol in astrocytes at the single-cell level using laser desorption ionization mass spectrometric imaging with colloidal silver.

    Science.gov (United States)

    Perdian, D C; Cha, Sangwon; Oh, Jisun; Sakaguchi, Donald S; Yeung, Edward S; Lee, Young Jin

    2010-04-30

    Mass spectrometric imaging has been utilized to localize individual astrocytes and to obtain cholesterol populations at the single-cell level in laser desorption ionization (LDI) with colloidal silver. The silver ion adduct of membrane-bound cholesterol was monitored to detect individual cells. Good correlation between mass spectrometric and optical images at different cell densities indicates the ability to perform single-cell studies of cholesterol abundance. The feasibility of quantification is confirmed by the agreement between the LDI-MS ion signals and the results from a traditional enzymatic fluorometric assay. We propose that this approach could be an effective tool to study chemical populations at the cellular level.

  17. Laryngeal cancer stem cells

    Directory of Open Access Journals (Sweden)

    Antonio Greco

    2016-03-01

    Full Text Available Laryngeal squamous cell carcinoma (LSCC is one of the most commonly diagnosed malignancies in the head and neck region with an increased incidence rate worldwide. Cancer stem cells (CSCs are a group of cells with eternal life or infinite self-renewal ability, which have high migrating, infiltrative, and metastatic abilities. Though CSCs only account for a small proportion in tumors, the high resistance to traditional therapy exempts them from therapy killing and thus they can reconstruct tumors. Our current knowledge, about CSCs in the LSCC, largely depends on head and neck studies with a lack of systematic data about the evidences of CSCs in tumorigenesis of LSCC. Certainly, the combination of therapies aimed at debulking the tumour (e.g. surgery, conventional chemotherapy, radiotherapy together with targeted therapies aimed at the elimination of the CSCs might have a positive impact on the long-term outcome of patients with laryngeal cancer (LC in the future and may cast a new light on the cancer treatment.

  18. The microRNA and messengerRNA profile of the RNA-induced silencing complex in human primary astrocyte and astrocytoma cells.

    Directory of Open Access Journals (Sweden)

    Joanna J Moser

    Full Text Available BACKGROUND: GW/P bodies are cytoplasmic ribonucleoprotein-rich foci involved in microRNA (miRNA-mediated messenger RNA (mRNA silencing and degradation. The mRNA regulatory functions within GW/P bodies are mediated by GW182 and its binding partner hAgo2 that bind miRNA in the RNA-induced silencing complex (RISC. To date there are no published reports of the profile of miRNA and mRNA targeted to the RISC or a comparison of the RISC-specific miRNA/mRNA profile differences in malignant and non-malignant cells. METHODOLOGY/PRINCIPAL FINDINGS: RISC mRNA and miRNA components were profiled by microarray analysis of malignant human U-87 astrocytoma cells and its non-malignant counterpart, primary human astrocytes. Total cell RNA as well as RNA from immunoprecipitated RISC was analyzed. The novel findings were fourfold: (1 miRNAs were highly enriched in astrocyte RISC compared to U-87 astrocytoma RISC, (2 astrocytoma and primary astrocyte cells each contained unique RISC miRNA profiles as compared to their respective cellular miRNA profiles, (3 miR-195, 10b, 29b, 19b, 34a and 455-3p levels were increased and the miR-181b level was decreased in U-87 astrocytoma RISC as compared to astrocyte RISC, and (4 the RISC contained decreased levels of mRNAs in primary astrocyte and U-87 astrocytoma cells. CONCLUSIONS/SIGNIFICANCE: The observation that miR-34a and miR-195 levels were increased in the RISC of U-87 astrocytoma cells suggests an oncogenic role for these miRNAs. Differential regulation of mRNAs by specific miRNAs is evidenced by the observation that three miR34a-targeted mRNAs and two miR-195-targeted mRNAs were downregulated while one miR-195-targeted mRNA was upregulated. Biological pathway analysis of RISC mRNA components suggests that the RISC plays a pivotal role in malignancy and other conditions. This study points to the importance of the RISC and ultimately GW/P body composition and function in miRNA and mRNA deregulation in astrocytoma cells and

  19. Fisetin regulates astrocyte migration and proliferation in vitro.

    Science.gov (United States)

    Wang, Nan; Yao, Fang; Li, Ke; Zhang, Lanlan; Yin, Guo; Du, Mingjun; Wu, Bingyi

    2017-02-15

    Fisetin (3,3',4',7-tetrahydroxyflavone) is a plant flavonol found in fruits and vegetables that has been reported to inhibit migration and proliferation in several types of cancer. Reactive astrogliosis involves astrocyte migration and proliferation, and contributes to the formation of glial scars in central nervous system (CNS) disorders. However, the effect of fisetin on the migration and proliferation of astrocytes remains unclear. In this study, we found that fisetin inhibited astrocyte migration in a scratch-wound assay and diminished the phosphorylation of focal adhesion kinase (FAK; Tyr576/577 and paxillin (Tyr118). It also suppressed cell proliferation, as indicated by the decreased number of 5-ethynyl-2'-deoxyuridine (EdU)-positive cells, induced cell cycle arrest in the G1 phase, reduced the percentage of cells in the G2 and S phase (as measured by flow cytometry), and decreased cyclin D1 expression, but had no effect on apoptosis. Fisetin also decreased the phosphorylation levels of Akt and extracellular signal-regulated kinase (Erk)1/2, but had no effect on the phosphorylation of p38 mitogen-activated protein kinase (MAPK). These results indicate that fisetin inhibits aggressive cell phenotypes by suppressing cell migration and proliferation via the Akt/Erk signaling pathway. Fisetin may thus have potential for use as a therapeutic strategy targeting reactive astrocytes, which may lead to the inhibition of glial scar formation in vitro.

  20. Mash1 efifciently reprograms rat astrocytes into neurons

    Institute of Scientific and Technical Information of China (English)

    Daofang Ding; Leqin Xu; Hao Xu; Xiaofeng Li; Qianqian Liang; Yongjian Zhao; Yongjun Wang

    2014-01-01

    To date, it remains poorly understood whether astrocytes can be easily reprogrammed into neurons. Mash1 and Brn2 have been previously shown to cooperate to reprogram fibroblasts into neurons. In this study, we examined astrocytes from 2-month-old Sprague-Dawley rats, and found that Brn2 was expressed, but Mash1 was not detectable. Thus, we hypothesized that Mash1 alone could be used to reprogram astrocytes into neurons. We transfected a recombinant MSCV-MASH1 plasmid into astrocytes for 72 hours, and saw that all cells expressed Mash1. One week later, we observed the changes in morphology of astrocytes, which showed typical neuro-nal characteristics. Moreover,β-tubulin expression levels were signiifcantly higher in astrocytes expressing Mash1 than in control cells. These results indicate that Mash1 alone can reprogram astrocytes into neurons.

  1. PEA-15 Induces Autophagy in Human Ovarian Cancer Cells and is Associated with Prolonged Overall Survival

    OpenAIRE

    Bartholomeusz, Chandra; Rosen, Daniel; Wei, Caimiao; Kazansky, Anna; Yamasaki, Fumiyuki; Takahashi, Takeshi; Itamochi, Hiroaki; KONDO, Seiji; Liu, Jinsong; Ueno, Naoto T

    2008-01-01

    Phospho-enriched protein in astrocytes (PEA-15) is a 15-kDa phosphoprotein that slows cell proliferation by binding to and sequestering extracellular signal-regulated kinase (ERK) in the cytoplasm, thereby inhibiting ERK-dependent transcription and proliferation. In previous studies of E1A human gene therapy for ovarian cancer, we discovered that PEA-15 induced the antitumor effect of E1A by sequestering activated ERK in the cytoplasm of cancer cells. Here, we investigated the role of PEA-15 ...

  2. Delayed transplantation of precursor cell-derived astrocytes provides multiple benefits in a rat model of Parkinsons.

    Science.gov (United States)

    Proschel, Christoph; Stripay, Jennifer L; Shih, Chung-Hsuan; Munger, Joshua C; Noble, Mark D

    2014-04-01

    In addition to dopaminergic neuron loss, it is clear that Parkinson disease includes other pathological changes, including loss of additional neuronal populations. As a means of addressing multiple pathological changes with a single therapeutically-relevant approach, we employed delayed transplantation of a unique class of astrocytes, GDAs(BMP), that are generated in vitro by directed differentiation of glial precursors. GDAs(BMP) produce multiple agents of interest as treatments for PD and other neurodegenerative disorders, including BDNF, GDNF, neurturin and IGF1. GDAs(BMP) also exhibit increased levels of antioxidant pathway components, including levels of NADPH and glutathione. Delayed GDA(BMP) transplantation into the 6-hydroxydopamine lesioned rat striatum restored tyrosine hydroxylase expression and promoted behavioral recovery. GDA(BMP) transplantation also rescued pathological changes not prevented in other studies, such as the rescue of parvalbumin(+) GABAergic interneurons. Consistent with expression of the synaptic modulatory proteins thrombospondin-1 and 2 by GDAs(BMP), increased expression of the synaptic protein synaptophysin was also observed. Thus, GDAs(BMP) offer a multimodal support cell therapy that provides multiple benefits without requiring prior genetic manipulation.

  3. A new prospect in cancer therapy: targeting cancer stem cells to eradicate cancer

    Institute of Scientific and Technical Information of China (English)

    Li-Sha Chen; An-Xin Wang; Bing Dong; Ke-Feng Pu; Li-Hua Yuan; Yi-Min Zhu

    2012-01-01

    According to the cancer stem cell theory,cancers can be initiated by cancer stem cells.This makes cancer stem cells prime targets for therapeutic intervention.Eradicating cancer stem cells by efficient targeting agents may have the potential to cure cancer.In this review,we summarize recent breakthroughs that have improved our understanding of cancer stem cells,and we discuss the therapeutic strategy of targeting cancer stem cells,a promising future direction for cancer stem cell research.

  4. Treatment Options for Renal Cell Cancer

    Science.gov (United States)

    ... cell cancer is a disease in which malignant (cancer) cells form in tubules of the kidney. Renal cell ... diagnosed, tests are done to find out if cancer cells have spread within the kidney or to other ...

  5. General Information about Renal Cell Cancer

    Science.gov (United States)

    ... cell cancer is a disease in which malignant (cancer) cells form in tubules of the kidney. Renal cell ... diagnosed, tests are done to find out if cancer cells have spread within the kidney or to other ...

  6. Treatment Option Overview (Renal Cell Cancer)

    Science.gov (United States)

    ... cell cancer is a disease in which malignant (cancer) cells form in tubules of the kidney. Renal cell ... diagnosed, tests are done to find out if cancer cells have spread within the kidney or to other ...

  7. Lung cancer - non-small cell

    Science.gov (United States)

    Cancer - lung - non-small cell; Non-small cell lung cancer; NSCLC; Adenocarcinoma - lung; Squamous cell carcinoma - lung ... Research shows that smoking marijuana may help cancer cells grow. But there is no direct link between ...

  8. Nitric Oxide in Astrocyte-Neuron Signaling

    Energy Technology Data Exchange (ETDEWEB)

    Nianzhen Li

    2002-06-27

    Astrocytes, a subtype of glial cell, have recently been shown to exhibit Ca{sup 2+} elevations in response to neurotransmitters. A Ca{sup 2+} elevation can propagate to adjacent astrocytes as a Ca{sup 2+} wave, which allows an astrocyte to communicate with its neighbors. Additionally, glutamate can be released from astrocytes via a Ca{sup 2+}-dependent mechanism, thus modulating neuronal activity and synaptic transmission. In this dissertation, the author investigated the roles of another endogenous signal, nitric oxide (NO), in astrocyte-neuron signaling. First the author tested if NO is generated during astrocytic Ca{sup 2+} signaling by imaging NO in purified murine cortical astrocyte cultures. Physiological concentrations of a natural messenger, ATP, caused a Ca{sup 2+}-dependent NO production. To test the roles of NO in astrocytic Ca{sup 2+} signaling, the author applied NO to astrocyte cultures via addition of a NO donor, S-nitrosol-N-acetylpenicillamine (SNAP). NO induced an influx of external Ca{sup 2+}, possibly through store-operated Ca{sup 2+} channels. The NO-induced Ca{sup 2+} signaling is cGMP-independent since 8-Br-cGMP, an agonistic analog of cGMP, did not induce a detectable Ca{sup 2+} change. The consequence of this NO-induced Ca{sup 2+} influx was assessed by simultaneously monitoring of cytosolic and internal store Ca{sup 2+} using fluorescent Ca{sup 2+} indicators x-rhod-1 and mag-fluo-4. Blockage of NO signaling with the NO scavenger PTIO significantly reduced the refilling percentage of internal stores following ATP-induced Ca{sup 2+} release, suggesting that NO modulates internal store refilling. Furthermore, locally photo-release of NO to a single astrocyte led to a Ca{sup 2+} elevation in the stimulated astrocyte and a subsequent Ca{sup 2+} wave to neighbors. Finally, the author tested the role of NO inglutamate-mediated astrocyte-neuron signaling by recording the astrocyte-evoked glutamate-dependent neuronal slow inward current (SIC

  9. Nitric Oxide in Astrocyte-Neuron Signaling

    Energy Technology Data Exchange (ETDEWEB)

    Li, Nianzhen [Iowa State Univ., Ames, IA (United States)

    2002-01-01

    Astrocytes, a subtype of glial cell, have recently been shown to exhibit Ca2+ elevations in response to neurotransmitters. A Ca2+ elevation can propagate to adjacent astrocytes as a Ca2+ wave, which allows an astrocyte to communicate with its neighbors. Additionally, glutamate can be released from astrocytes via a Ca2+-dependent mechanism, thus modulating neuronal activity and synaptic transmission. In this dissertation, the author investigated the roles of another endogenous signal, nitric oxide (NO), in astrocyte-neuron signaling. First the author tested if NO is generated during astrocytic Ca2+ signaling by imaging NO in purified murine cortical astrocyte cultures. Physiological concentrations of a natural messenger, ATP, caused a Ca2+-dependent NO production. To test the roles of NO in astrocytic Ca2+ signaling, the author applied NO to astrocyte cultures via addition of a NO donor, S-nitrosol-N-acetylpenicillamine (SNAP). NO induced an influx of external Ca2+, possibly through store-operated Ca2+ channels. The NO-induced Ca2+ signaling is cGMP-independent since 8-Br-cGMP, an agonistic analog of cGMP, did not induce a detectable Ca2+ change. The consequence of this NO-induced Ca2+ influx was assessed by simultaneously monitoring of cytosolic and internal store Ca2+ using fluorescent Ca2+ indicators x-rhod-1 and mag-fluo-4. Blockage of NO signaling with the NO scavenger PTIO significantly reduced the refilling percentage of internal stores following ATP-induced Ca2+ release, suggesting that NO modulates internal store refilling. Furthermore, locally photo-release of NO to a single astrocyte led to a Ca2+ elevation in the stimulated astrocyte and a subsequent Ca2+ wave to neighbors. Finally, the author tested the role of NO inglutamate-mediated astrocyte-neuron signaling by

  10. Reprogramming of HUVECs into Induced Pluripotent Stem Cells (HiPSCs), Generation and Characterization of HiPSC-Derived Neurons and Astrocytes

    Science.gov (United States)

    Boakye, Paul A.; Baker, Glen; Smith, Peter A.; Murray, Allan G.; Giuliani, Fabrizio; Jahroudi, Nadia

    2015-01-01

    Neurodegenerative diseases are characterized by chronic and progressive structural or functional loss of neurons. Limitations related to the animal models of these human diseases have impeded the development of effective drugs. This emphasizes the need to establish disease models using human-derived cells. The discovery of induced pluripotent stem cell (iPSC) technology has provided novel opportunities in disease modeling, drug development, screening, and the potential for “patient-matched” cellular therapies in neurodegenerative diseases. In this study, with the objective of establishing reliable tools to study neurodegenerative diseases, we reprogrammed human umbilical vein endothelial cells (HUVECs) into iPSCs (HiPSCs). Using a novel and direct approach, HiPSCs were differentiated into cells of central nervous system (CNS) lineage, including neuronal, astrocyte and glial cells, with high efficiency. HiPSCs expressed embryonic genes such as nanog, sox2 and Oct-3/4, and formed embryoid bodies that expressed markers of the 3 germ layers. Expression of endothelial-specific genes was not detected in HiPSCs at RNA or protein levels. HiPSC-derived neurons possess similar morphology but significantly longer neurites compared to primary human fetal neurons. These stem cell-derived neurons are susceptible to inflammatory cell-mediated neuronal injury. HiPSC-derived neurons express various amino acids that are important for normal function in the CNS. They have functional receptors for a variety of neurotransmitters such as glutamate and acetylcholine. HiPSC-derived astrocytes respond to ATP and acetylcholine by elevating cytosolic Ca2+ concentrations. In summary, this study presents a novel technique to generate differentiated and functional HiPSC-derived neurons and astrocytes. These cells are appropriate tools for studying the development of the nervous system, the pathophysiology of various neurodegenerative diseases and the development of potential drugs for their

  11. Extensive astrocyte infection is prominent in human immunodeficiency virus-associated dementia.

    Science.gov (United States)

    Churchill, Melissa J; Wesselingh, Steven L; Cowley, Daniel; Pardo, Carlos A; McArthur, Justin C; Brew, Bruce J; Gorry, Paul R

    2009-08-01

    Astrocyte infection with human immunodeficiency virus (HIV) is considered rare, so astrocytes are thought to play a secondary role in HIV neuropathogenesis. By combining double immunohistochemistry, laser capture microdissection, and highly sensitive multiplexed polymerase chain reaction to detect HIV DNA in single astrocytes in vivo, we showed that astrocyte infection is extensive in subjects with HIV-associated dementia, occurring in up to 19% of GFAP+ cells. In addition, astrocyte infection frequency correlated with the severity of neuropathological changes and proximity to perivascular macrophages. Our data indicate that astrocytes can be extensively infected with HIV, and suggest an important role for HIV-infected astrocytes in HIV neuropathogenesis.

  12. Implications of astrocytes in mediating the protective effects of Selective Estrogen Receptor Modulators upon brain damage

    Directory of Open Access Journals (Sweden)

    George E. Barreto

    2015-04-01

    Full Text Available Selective Estrogen Receptor Modulators (SERMs are steroidal or non-steroidal compounds that are already used in clinical practice for the treatment of breast cancer, osteoporosis and menopausal symptoms. While SERMs actions in the breast, bone, and uterus have been well characterized, their actions in the brain are less well understood. Previous works have demonstrated the beneficial effects of SERMs in different chronic neurodegenerative diseases like Alzheimer, Parkinson’s disease and Multiple sclerosis, as well as acute degeneration as stroke and traumatic brain injury. Moreover, these compounds exhibit similar protective actions as those of estradiol in the Central Nervous System, overt any secondary effect. For these reasons, in the past few years, there has been a growing interest in the neuroprotective effects exerted directly or indirectly by SERMs in the SNC. In this context, astrocytes play an important role in the maintenance of brain metabolism, and antioxidant support to neurons, thus indicating that better protection of astrocytes are an important asset targeting neuronal protection. Moreover, various clinical and experimental studies have reported that astrocytes are essential for the neuroprotective effects of SERMs during neuronal injuries, as these cells express different estrogen receptors in cell membrane, demonstrating that part of SERMs effects upon injury may be mediated by astrocytes. The present work highlights the current evidence on the protective mechanisms of SERMs, such as tamoxifen and raloxifene, in the SNC, and their modulation of astrocytic properties as promising therapeutic targets during brain damage.

  13. Furin mediates brain-derived neurotrophic factor upregulation in cultured rat astrocytes exposed to oxygen-glucose deprivation.

    Science.gov (United States)

    Chen, Yan; Zhang, Junjian; Deng, Min

    2015-01-01

    This study investigated the changes in brain-derived neurotrophic factor (BDNF) expression and the role of furin in BDNF maturation in reactive astrocytes from rats exposed to oxygen-glucose deprivation (OGD). Furin, a proprotein convertase, is upregulated and cleaves certain substrates during hypoxia in cancer cells. In addition, during hypoxia in the central nervous system, astrocytes become reactive and release BDNF to protect neurons. Maturation of BDNF in astrocytes requires furin-mediated endoproteolytic processing of the precursor protein pro-BDNF to BDNF. To expand our knowledge about the role of furin in BDNF maturation in astrocytes, these cells were exposed to OGD, and expression of furin and BDNF was detected by Western blot analysis. Changes in BDNF expression were observed when furin activity was inhibited by furin prosegment. We found that protein expression of BDNF and furin was upregulated, and this upregulation correlated with OGD stimulation. Furin inhibition reduced BDNF maturation and secretion. These results indicate that furin mediates the upregulation of BDNF in reactive astrocytes exposed to OGD and that furin may impact the biological effect of reactive astrocytes.

  14. Astrocyte-Synapse Structural Plasticity

    Directory of Open Access Journals (Sweden)

    Yann Bernardinelli

    2014-01-01

    Full Text Available The function and efficacy of synaptic transmission are determined not only by the composition and activity of pre- and postsynaptic components but also by the environment in which a synapse is embedded. Glial cells constitute an important part of this environment and participate in several aspects of synaptic functions. Among the glial cell family, the roles played by astrocytes at the synaptic level are particularly important, ranging from the trophic support to the fine-tuning of transmission. Astrocytic structures are frequently observed in close association with glutamatergic synapses, providing a morphological entity for bidirectional interactions with synapses. Experimental evidence indicates that astrocytes sense neuronal activity by elevating their intracellular calcium in response to neurotransmitters and may communicate with neurons. The precise role of astrocytes in regulating synaptic properties, function, and plasticity remains however a subject of intense debate and many aspects of their interactions with neurons remain to be investigated. A particularly intriguing aspect is their ability to rapidly restructure their processes and modify their coverage of the synaptic elements. The present review summarizes some of these findings with a particular focus on the mechanisms driving this form of structural plasticity and its possible impact on synaptic structure and function.

  15. Mutant ubiquitin attenuates interleukin-1β- and tumor necrosis factor-α-induced pro-inflammatory signaling in human astrocytic cells.

    Directory of Open Access Journals (Sweden)

    Kyungsun Choi

    Full Text Available A frameshift mutation of ubiquitin called ubiquitin(+1 (UBB(+1 was found in the aging and Alzheimer's disease brains and thought to be associated with neuronal dysfuction and degeneration. Even though ubiquitylation has been known to regulate vital cellular functions mainly through proteasome-dependent degradation of polyubiquitinated substrates, proteolysis-independent roles of ubiquitylation have emerged as key mechanisms in various signaling cascades. In this study, we have investigated the effect of UBB(+1 on proinflammatory signaling such as interleukin-1β (IL-1β and tumor necrosis factor-α (TNF-α in human astrocytes. Treatment with TNF-α and IL-1β induced expression of CCL2 and CXCL8 by human astrocytic cells; while ectopic expression of UBB(+1 significantly abrogated the proinflammatory cytokine-induced expression of chemokines. Ectopic expression of UBB(+1 suppressed TNF-α- and IL-1β-induced activation of NF-κB and JNK signaling pathway. Furthermore, we have demonstrated that polyubiquitylation of TRAFs and subsequent phosphorylation of TAK1 were significantly inhibited by stable expression of UBB(+1. Collectively, these results suggest that UBB(+1 may affect proinflammatory signaling in the central nervous system via inhibitory mechanisms of ubiquitin-dependent signaling in human astrocytes.

  16. Astrocyte-Synapse Structural Plasticity

    OpenAIRE

    2014-01-01

    The function and efficacy of synaptic transmission are determined not only by the composition and activity of pre- and postsynaptic components but also by the environment in which a synapse is embedded. Glial cells constitute an important part of this environment and participate in several aspects of synaptic functions. Among the glial cell family, the roles played by astrocytes at the synaptic level are particularly important, ranging from the trophic support to the fine-tuning of transmissi...

  17. Astrocyte Elevated Gene-1 as a Novel Clinicopathological and Prognostic Biomarker for Gastrointestinal Cancers: A Meta-Analysis with 2999 Patients.

    Directory of Open Access Journals (Sweden)

    Yihuan Luo

    Full Text Available There have been numerous articles as to whether the staining index (SI of astrocyte elevated gene-1 (AEG-1 adversely affects clinical progression and prognosis of gastrointestinal cancers. Nevertheless, controversy still exists in terms of correlations between AEG-1 SI and clinicopathological parameters including survival data. Consequently, we conducted a comprehensive meta-analysis to confirm the role of AEG-1 in clinical outcomes of gastrointestinal carcinoma patients.We performed a comprehensive search in PubMed, ISI Web of Science, Cochrane Central Register of Controlled Trials, EMBASE, Science Direct, Wiley Online Library, China National Knowledge Infrastructure (CNKI, WanFang and Chinese VIP databases. STATA 12.0 (STATA Corp., College, TX was used to analyze the data extracted from suitable studies and Newcastle-Ottawa Scale was applied to assess the quality of included articles.The current meta-analysis included 2999 patients and our results suggested that strong associations emerged between AEG-1 SI and histological differentiation (OR = 2.129, 95%CI: 1.377-3.290, P = 0.001, tumor (T classification (OR = 2.272, 95%CI: 1.147-4.502, P = 0.019, lymph node (N classification (OR = 2.696, 95%CI: 2.178-3.337, P<0.001 and metastasis (M classification (OR = 3.731, 95%CI: 2.167-6.426, P<0.001. Furthermore, high AEG-1 SI was significantly associated with poor overall survival (OS (HR = 2.369, 95%CI: 2.005-2.800, P<0.001 and deteriorated disease-free survival (DFS (HR = 1.538, 95%CI: 1.171-2.020, P = 0.002. For disease-specific survival (DSS and relapse-free survival (RFS, no statistically significant results were observed (HR = 1.573, 95%CI: 0.761-3.250, P = 0.222; HR = 1.432, 95%CI: 0.108-19.085, P = 0.786. Subgroup analysis demonstrated that high AEG-1 SI was significantly related to poor prognosis in esophageal squamous cell carcinoma (ESCC (HR = 1.715, 95%CI: 1.211-2.410, P = 0.002, gastric carcinoma (GC (HR = 2.255, 95%CI: 1.547-3.288, P<0

  18. Modulation of polymorphonuclear neutrophil functions by astrocytes

    Directory of Open Access Journals (Sweden)

    Xie Luokun

    2010-09-01

    Full Text Available Abstract Background Neuroinflammation is a complex process involving cells from the immune system and the central nerve system (CNS. Polymorphonuclear neutrophils (PMN are the most abundant class of white blood cells, and typically the first type of leukocyte recruited to sites of inflammation. In the CNS, astrocytes are the most abundant glial cell population and participate in the local innate immune response triggered by a variety of insults. In the present study, we investigated the impacts of astrocytes on PMN function. Methods Primary astrocyte cultures were derived from postnatal C57BL/6 mice and primary neutrophils were isolated from 8 to 12 weeks old C57BL/6 mice. PMNs respiratory burst was analyzed by H2DCFDA assay. For phagocytosis assay, neutrophils were incubated with FITC-labeled E. coli and the phagocytosis of E coli was determined by flow cytometer. PMNs degranulation was determined by myeloperoxidase assay. Cytokine expression was determined by real-time PCR. To determine the involvement of different signaling pathway, protein lysates were prepared and western blots were conducted to assess the activation of Akt, Erk1/2, and p38. Results Using ex vivo neutrophils and primary astrocyte cultures, our study demonstrated that astrocytes differentially regulate neutrophil functions, depending upon whether the interactions between the two cell types are direct or indirect. Upon direct cell-cell contact, astrocytes attenuate neutrophil apoptosis, respiratory bust, and degranulation, while enhancing neutrophil phagocytic capability and pro-inflammatory cytokine expression. Through indirect interaction with neutrophils, astrocytes attenuate apoptosis and enhance necrosis in neutrophils, augment neutrophil phagocytosis and respiratory burst, and inhibit neutrophil degranulation. In addition, astrocytes could augment Akt, Erk1/2, and p38 activation in neutrophils. Conclusions Astrocytes differentially regulate neutrophil functions through

  19. Anions Govern Cell Volume: A Case Study of Relative Astrocytic and Neuronal Swelling in Spreading Depolarization.

    Directory of Open Access Journals (Sweden)

    Niklas Hübel

    Full Text Available Cell volume changes are ubiquitous in normal and pathological activity of the brain. Nevertheless, we know little about the dynamics of cell and tissue swelling, and the differential changes in the volumes of neurons and glia during pathological states such as spreading depolarizations (SD under ischemic and non-ischemic conditions, and epileptic seizures. By combining the Hodgkin-Huxley type spiking dynamics, dynamic ion concentrations, and simultaneous neuronal and astroglial volume changes into a comprehensive model, we elucidate why glial cells swell more than neurons in SD and the special case of anoxic depolarization (AD, and explore the relative contributions of the two cell types to tissue swelling. Our results demonstrate that anion channels, particularly Cl-, are intrinsically connected to cell swelling and blocking these currents prevents changes in cell volume. The model is based on a simple and physiologically realistic description. We introduce model extensions that are either derived purely from first physical principles of electroneutrality, osmosis, and conservation of particles, or by a phenomenological combination of these principles and known physiological facts. This work provides insights into numerous studies related to neuronal and glial volume changes in SD that otherwise seem contradictory, and is broadly applicable to swelling in other cell types and conditions.

  20. Astrocytic glycogenolysis: mechanisms and functions.

    Science.gov (United States)

    Hertz, Leif; Xu, Junnan; Song, Dan; Du, Ting; Li, Baoman; Yan, Enzhi; Peng, Liang

    2015-02-01

    Until the demonstration little more than 20 years ago that glycogenolysis occurs during normal whisker stimulation glycogenolysis was regarded as a relatively uninteresting emergency procedure. Since then, a series of important astrocytic functions has been shown to be critically dependent on glycogenolytic activity to support the signaling mechanisms necessary for these functions to operate. This applies to glutamate formation and uptake and to release of ATP as a transmitter, stimulated by other transmitters or elevated K(+) concentrations and affecting not only other astrocytes but also most other brain cells. It is also relevant for astrocytic K(+) uptake both during the period when the extracellular K(+) concentration is still elevated after neuronal excitation, and capable of stimulating glycogenolytic activity, and during the subsequent undershoot after intense neuronal activity, when glycogenolysis may be stimulated by noradrenaline. Both elevated K(+) concentrations and several transmitters, including the β-adrenergic agonist isoproterenol and vasopressin increase free cytosolic Ca(2+) concentration in astrocytes, which stimulates phosphorylase kinase so that it activates the transformation of the inactive glycogen phosphorylase a to the active phosphorylase b. Contrary to common belief cyclic AMP plays at most a facilitatory role, and only when free cytosolic Ca(2+) concentration is also increased. Cyclic AMP is not increased during activation of glycogenolysis by either elevated K(+) concentrations or the stimulation of the serotonergic 5-HT(2B) receptor. Not all agents that stimulate glycogenolysis do so by directly activating phophorylase kinase--some do so by activating processes requiring glycogenolysis, e.g. for synthesis of glutamate.

  1. Isolation and Characterization of Ischemia-Derived Astrocytes (IDAs) with Ability to Transactivate Quiescent Astrocytes

    Science.gov (United States)

    Villarreal, Alejandro; Rosciszewski, Gerardo; Murta, Veronica; Cadena, Vanesa; Usach, Vanina; Dodes-Traian, Martin M.; Setton-Avruj, Patricia; Barbeito, Luis H.; Ramos, Alberto J.

    2016-01-01

    Reactive gliosis involving activation and proliferation of astrocytes and microglia, is a widespread but largely complex and graded glial response to brain injury. Astroglial population has a previously underestimated high heterogeneity with cells differing in their morphology, gene expression profile, and response to injury. Here, we identified a subset of reactive astrocytes isolated from brain focal ischemic lesions that show several atypical characteristics. Ischemia-derived astrocytes (IDAs) were isolated from early ischemic penumbra and core. IDA did not originate from myeloid precursors, but rather from pre-existing local progenitors. Isolated IDA markedly differ from primary astrocytes, as they proliferate in vitro with high cell division rate, show increased migratory ability, have reduced replicative senescence and grow in the presence of macrophages within the limits imposed by the glial scar. Remarkably, IDA produce a conditioned medium that strongly induced activation on quiescent primary astrocytes and potentiated the neuronal death triggered by oxygen-glucose deprivation. When re-implanted into normal rat brains, eGFP-IDA migrated around the injection site and induced focal reactive gliosis. Inhibition of gamma secretases or culture on quiescent primary astrocytes monolayers facilitated IDA differentiation to astrocytes. We propose that IDA represent an undifferentiated, pro-inflammatory, highly replicative and migratory astroglial subtype emerging from the ischemic microenvironment that may contribute to the expansion of reactive gliosis. Main Points: Ischemia-derived astrocytes (IDA) were isolated from brain ischemic tissue IDA show reduced replicative senescence, increased cell division and spontaneous migration IDA potentiate death of oxygen-glucose deprived cortical neurons IDA propagate reactive gliosis on quiescent astrocytes in vitro and in vivo Inhibition of gamma secretases facilitates IDA differentiation to astrocytes PMID:27313509

  2. Cancer stem cell markers in common cancers - therapeutic implications

    DEFF Research Database (Denmark)

    Klonisch, Thomas; Wiechec, Emilia; Hombach-Klonisch, Sabine

    2008-01-01

    Rapid advance in the cancer stem cell field warrants optimism for the development of more reliable cancer therapies within the next 2-3 decades. Below, we characterize and compare the specific markers that are present on stem cells, cancer cells and cancer stem cells (CSC) in selected tissues...

  3. 3-bromopyruvate inhibits glycolysis, depletes cellular glutathione, and compromises the viability of cultured primary rat astrocytes.

    Science.gov (United States)

    Ehrke, Eric; Arend, Christian; Dringen, Ralf

    2015-07-01

    The pyruvate analogue 3-bromopyruvate (3-BP) is an electrophilic alkylator that is considered a promising anticancer drug because it has been shown to kill cancer cells efficiently while having little toxic effect on nontumor cells. To test for potential adverse effects of 3-BP on brain cells, we exposed cultured primary rat astrocytes to 3-BP and investigated the effects of this compound on cell viability, glucose metabolism, and glutathione (GSH) content. The presence of 3-BP severely compromised cell viability and slowed cellular glucose consumption and lactate production in a time- and concentration-dependent manner, with half-maximal effects observed at about 100 µM 3-BP after 4 hr of incubation. The cellular hexokinase activity was not affected in 3-BP-treated astrocytes, whereas within 30 min after application of 3-BP the activity of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was inhibited, and cellular GSH content was depleted in a concentration-dependent manner, with half-maximal effects observed at about 30 µM 3-BP. The depletion of cellular GSH after exposure to 100 µM 3-BP was not prevented by the presence of 10 mM of the monocarboxylates lactate or pyruvate, suggesting that 3-BP is not taken up into astrocytes predominantly by monocarboxylate transporters. The data suggest that inhibition of glycolysis by inactivation of GAPDH and GSH depletion contributes to the toxicity that was observed for 3-BP-treated cultured astrocytes.

  4. Inflammatory cytokines IL-1β and TNF-α regulate p75NTR expression in CNS neurons and astrocytes by distinct cell-type-specific signalling mechanisms

    Directory of Open Access Journals (Sweden)

    Wilma J Friedman

    2009-05-01

    Full Text Available The p75NTR (where NTR is neurotrophin receptor can mediate many distinct cellular functions, including cell survival and apoptosis, axonal growth and cell proliferation, depending on the cellular context. This multifunctional receptor is widely expressed in the CNS (central nervous system during development, but its expression is restricted in the adult brain. However, p75NTR is induced by a variety of pathophysiological insults, including seizures, lesions and degenerative disease. We have demonstrated previously that p75NTR is induced by seizures in neurons, where it induces apoptosis, and in astrocytes, where it may regulate proliferation. In the present study, we have investigated whether the inflammatory cytokines IL (interleukin-1β and TNF-α (tumour necrosis factor-α, that are commonly elevated in these pathological conditions, mediate the regulation of p75NTR in neurons and astrocytes. We have further analysed the signal transduction pathways by which these cytokines induce p75NTR expression in the different cell types, specifically investigating the roles of the NF-κB (nuclear factor κB and p38 MAPK (mitogen-activated protein kinase pathways. We have demonstrated that both cytokines regulate p75NTR expression; however, the mechanisms governing this regulation are cytokine- and cell-type specific. The distinct mechanisms of cytokine-mediated p75NTR regulation that we demonstrate in the present study may facilitate therapeutic intervention in regulation of this receptor in a cell-selective manner.

  5. Achillolide A Protects Astrocytes against Oxidative Stress by Reducing Intracellular Reactive Oxygen Species and Interfering with Cell Signaling

    Directory of Open Access Journals (Sweden)

    Anat Elmann

    2016-03-01

    Full Text Available Achillolide A is a natural sesquiterpene lactone that we have previously shown can inhibit microglial activation. In this study we present evidence for its beneficial effects on astrocytes under oxidative stress, a situation relevant to neurodegenerative diseases and brain injuries. Viability of brain astrocytes (primary cultures was determined by lactate dehydrogenase (LDH activity, intracellular ROS levels were detected using 2′,7′-dichlorofluorescein diacetate, in vitro antioxidant activity was measured by differential pulse voltammetry, and protein phosphorylation was determined using specific ELISA kits. We have found that achillolide A prevented the H2O2-induced death of astrocytes, and attenuated the induced intracellular accumulation of reactive oxygen species (ROS. These activities could be attributed to the inhibition of the H2O2-induced phosphorylation of MAP/ERK kinase 1 (MEK1 and p44/42 mitogen-activated protein kinases (MAPK, and to the antioxidant activity of achillolide A, but not to H2O2 scavenging. This is the first study that demonstrates its protective effects on brain astrocytes, and its ability to interfere with MAPK activation. We propose that achillolide A deserves further evaluation for its potential to be developed as a drug for the prevention/treatment of neurodegenerative diseases and brain injuries where oxidative stress is part of the pathophysiology.

  6. Cancer stem cells in human gastrointestinal cancer.

    Science.gov (United States)

    Taniguchi, Hiroaki; Moriya, Chiharu; Igarashi, Hisayoshi; Saitoh, Anri; Yamamoto, Hiroyuki; Adachi, Yasushi; Imai, Kohzoh

    2016-11-01

    Cancer stem cells (CSCs) are thought to be responsible for tumor initiation, drug and radiation resistance, invasive growth, metastasis, and tumor relapse, which are the main causes of cancer-related deaths. Gastrointestinal cancers are the most common malignancies and still the most frequent cause of cancer-related mortality worldwide. Because gastrointestinal CSCs are also thought to be resistant to conventional therapies, an effective and novel cancer treatment is imperative. The first reported CSCs in a gastrointestinal tumor were found in colorectal cancer in 2007. Subsequently, CSCs were reported in other gastrointestinal cancers, such as esophagus, stomach, liver, and pancreas. Specific phenotypes could be used to distinguish CSCs from non-CSCs. For example, gastrointestinal CSCs express unique surface markers, exist in a side-population fraction, show high aldehyde dehydrogenase-1 activity, form tumorspheres when cultured in non-adherent conditions, and demonstrate high tumorigenic potential in immunocompromised mice. The signal transduction pathways in gastrointestinal CSCs are similar to those involved in normal embryonic development. Moreover, CSCs are modified by the aberrant expression of several microRNAs. Thus, it is very difficult to target gastrointestinal CSCs. This review focuses on the current research on gastrointestinal CSCs and future strategies to abolish the gastrointestinal CSC phenotype.

  7. Ecdysterone protects gerbil brain from temporal global cerebral ischemia/reperfusion injury via preventing neuron apoptosis and deactivating astrocytes and microglia cells.

    Science.gov (United States)

    Wang, Wei; Wang, Tao; Feng, Wan-Yu; Wang, Zhan-You; Cheng, Mao-Sheng; Wang, Yun-Jie

    2014-01-01

    Ecdysterone (EDS), a common derivative of ecdysteroid, has shown its effects on alleviating cognitive impairment and improving the cognition and memory. However, the mechanisms remain unknown. Using temporal global forebrain ischemia and reperfusion-induced brain injury as a model system, we investigated the roles of EDS in improving cognitive impairment in gerbil. Our results demonstrated that intraperitoneal injection of EDS obviously increased the number of surviving neuron cells by Nissl and neuronal nuclei (NeuN) staining. Indeed, the protecting effects of EDS are because of its ability to prevent the apoptosis of neuron cells as evidenced by TUNEL staining and caspase-3 deactivation in the brain of temporal global forebrain ischemia/reperfusion-treated gerbil. Moreover, EDS administration suppressed the ischemia stimulated activity of astrocytes and microglia cells by inhibiting the production of tumor necrosis alpha (TNF-α) in the brain of gerbil. More importantly, these actions of neurons and astrocytes/microglia cells in response to EDS treatment played pivotal roles in ameliorating the cognitive impairment in the ischemia/reperfusion-injured gerbil. In view of these observations, we not only decipher the mechanisms of EDS in reducing the syndrome of ischemia, but also provide novel perspectives to combat ischemic stroke.

  8. Co-culture with microglia promotes neural stem cells differentiation into astrocytes

    Institute of Scientific and Technical Information of China (English)

    GU Feng; WANG Juan; FU Li; MA Yong-jie

    2011-01-01

    Background Neural stem cells (NSCs) are a self-renewing and multipotent population of the central nervous system (CNS),which are active during development and maintain homeostasis and tissue integrity throughout life.Microglias are an immune cell population resident in the CNS,which have crucial physiological functions in the developing and adult CNS.This study aimed to investigate that whether microglia co-cultured with NSCs could promote astrogliogenesis from NSCs.Methods Microglia and NSCs were co-cultured in 24-well insert plates.NSCs were plated in the bottom of the well and microglia in the insert.Fluorescent staining,Western blotting and RT-PCR were used to determine the effect of microglia on NSCs differentiation.Results Co-culture of microglia and NSCs promoted astrogliogenesis from NSCs.Several key genes,such as Notch 1,Notch 2,Notch 3,Hes 5,and NRSFwera downregulated,while the critical genes Id1 and Id2 were upregulated.BMP2 and FGF2 were upregulated.Conclusion Microglias act as a regulator of NSCs astrogliogenesis.

  9. Astrocytic Vesicle Mobility in Health and Disease

    Directory of Open Access Journals (Sweden)

    Robert Zorec

    2013-05-01

    Full Text Available Astrocytes are no longer considered subservient to neurons, and are, instead, now understood to play an active role in brain signaling. The intercellular communication of astrocytes with neurons and other non-neuronal cells involves the exchange of molecules by exocytotic and endocytotic processes through the trafficking of intracellular vesicles. Recent studies of single vesicle mobility in astrocytes have prompted new views of how astrocytes contribute to information processing in nervous tissue. Here, we review the trafficking of several types of membrane-bound vesicles that are specifically involved in the processes of (i intercellular communication by gliotransmitters (glutamate, adenosine 5'-triphosphate, atrial natriuretic peptide, (ii plasma membrane exchange of transporters and receptors (EAAT2, MHC-II, and (iii the involvement of vesicle mobility carrying aquaporins (AQP4 in water homeostasis. The properties of vesicle traffic in astrocytes are discussed in respect to networking with neighboring cells in physiologic and pathologic conditions, such as amyotrophic lateral sclerosis, multiple sclerosis, and states in which astrocytes contribute to neuroinflammatory conditions.

  10. Astrocytic vesicle mobility in health and disease.

    Science.gov (United States)

    Potokar, Maja; Vardjan, Nina; Stenovec, Matjaž; Gabrijel, Mateja; Trkov, Saša; Jorgačevski, Jernej; Kreft, Marko; Zorec, Robert

    2013-01-01

    Astrocytes are no longer considered subservient to neurons, and are, instead, now understood to play an active role in brain signaling. The intercellular communication of astrocytes with neurons and other non-neuronal cells involves the exchange of molecules by exocytotic and endocytotic processes through the trafficking of intracellular vesicles. Recent studies of single vesicle mobility in astrocytes have prompted new views of how astrocytes contribute to information processing in nervous tissue. Here, we review the trafficking of several types of membrane-bound vesicles that are specifically involved in the processes of (i) intercellular communication by gliotransmitters (glutamate, adenosine 5'-triphosphate, atrial natriuretic peptide), (ii) plasma membrane exchange of transporters and receptors (EAAT2, MHC-II), and (iii) the involvement of vesicle mobility carrying aquaporins (AQP4) in water homeostasis. The properties of vesicle traffic in astrocytes are discussed in respect to networking with neighboring cells in physiologic and pathologic conditions, such as amyotrophic lateral sclerosis, multiple sclerosis, and states in which astrocytes contribute to neuroinflammatory conditions.

  11. Handling of Copper and Copper Oxide Nanoparticles by Astrocytes.

    Science.gov (United States)

    Bulcke, Felix; Dringen, Ralf

    2016-02-01

    Copper is an essential trace element for many important cellular functions. However, excess of copper can impair cellular functions by copper-induced oxidative stress. In brain, astrocytes are considered to play a prominent role in the copper homeostasis. In this short review we summarise the current knowledge on the molecular mechanisms which are involved in the handling of copper by astrocytes. Cultured astrocytes efficiently take up copper ions predominantly by the copper transporter Ctr1 and the divalent metal transporter DMT1. In addition, copper oxide nanoparticles are rapidly accumulated by astrocytes via endocytosis. Cultured astrocytes tolerate moderate increases in intracellular copper contents very well. However, if a given threshold of cellular copper content is exceeded after exposure to copper, accelerated production of reactive oxygen species and compromised cell viability are observed. Upon exposure to sub-toxic concentrations of copper ions or copper oxide nanoparticles, astrocytes increase their copper storage capacity by upregulating the cellular contents of glutathione and metallothioneins. In addition, cultured astrocytes have the capacity to export copper ions which is likely to involve the copper ATPase 7A. The ability of astrocytes to efficiently accumulate, store and export copper ions suggests that astrocytes have a key role in the distribution of copper in brain. Impairment of this astrocytic function may be involved in diseases which are connected with disturbances in brain copper metabolism.

  12. Motor neuron death in ALS – programmed by astrocytes?

    Science.gov (United States)

    Pirooznia, Sheila K.; Dawson, Valina L.; Dawson, Ted M.

    2014-01-01

    Motor neurons in ALS die via cell-autonomous and non-cell autonomous mechanisms. Using adult human astrocytes and motor neurons, Re et al (2014) discover that familial and sporadic ALS derived human adult astrocytes secrete neurotoxic factors that selectively kill motor neurons through necroptosis, suggesting a new therapeutic avenue. PMID:24607221

  13. General Information about Small Cell Lung Cancer

    Science.gov (United States)

    ... lung cancer is a disease in which malignant (cancer) cells form in the tissues of the lung. The ... diagnosed, tests are done to find out if cancer cells have spread within the chest or to other ...

  14. Treatment Option Overview (Small Cell Lung Cancer)

    Science.gov (United States)

    ... lung cancer is a disease in which malignant (cancer) cells form in the tissues of the lung. The ... diagnosed, tests are done to find out if cancer cells have spread within the chest or to other ...

  15. Stages of Small Cell Lung Cancer

    Science.gov (United States)

    ... lung cancer is a disease in which malignant (cancer) cells form in the tissues of the lung. The ... diagnosed, tests are done to find out if cancer cells have spread within the chest or to other ...

  16. Impact of flattening-filter-free radiation on the clonogenic survival of astrocytic cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Steenken, Caroline; Fleckenstein, Jens; Kegel, Stefan; Jahnke, Lennart; Simeonova, Anna; Hartmann, Linda; Kuebler, Jens; Veldwijk, Marlon R.; Wenz, Frederik; Herskind, Carsten; Giordano, Frank Anton [Universitaetsmedizin Mannheim (UMM), Medical Faculty Mannheim, Heidelberg University, Department of Radiation Oncology, Mannheim (Germany)

    2015-07-15

    Flattening-filter-free (FFF) beams are increasingly used in radiotherapy as delivery times can be substantially reduced. However, the relative biologic effectiveness (RBE) of FFF may be increased relative to conventional flattened (FLAT) beams due to differences in energy spectra. Therefore, we investigated the effects of FFF and FLAT beams on the clonogenic survival of astrocytoma cells. Three cell lines (U251, U251-MGMT, and U87) were irradiated with 6-MV and 10-MV X-rays from a linear accelerator in FFF- or FLAT-beam modes at dose rates in the range of 0.5-24 Gy/min. The surviving fraction (SF) as function of dose (2-12 Gy) was determined by the colony formation assay and fitted by the linear-quadratic model. For both beams (FFF or FLAT), the cells were pelleted in conical 15-ml centrifuge tubes and irradiated at 2-cm depth in a 1 x 1-cm{sup 2} area on the central axis of a 30 x 30-cm{sup 2} field. Dosimetry was performed with a 0.3-cm{sup 3} rigid ionization chamber. RBE was determined for FFF versus FLAT irradiation. The RBE of FFF at 7.3-11.3 Gy was 1.027 ± 0.013 and 1.063 ± 0.018 relative to FLAT beams for 6- and 10-MV beams, respectively, and was only significantly higher than 1 for 10 MV. Significantly increased survival rates were seen for lower dose rates (0.5 Gy/min FLAT vs. 5 Gy/min FLAT) at higher doses (11.9 Gy), while no differences were seen at dose rates ≥ 1.4 Gy/min (1.4 Gy/min FFF vs. 14 Gy/min FFF and 2.4 Gy/min FFF vs. 24 Gy/min FFF). FFF beams showed only a slightly increased RBE relative to FLAT beams in this experimental set-up, which is unlikely to result in clinically relevant differences in outcome. (orig.) [German] Die Flattening-Filter-freie (FFF) Bestrahlungstechnik findet zunehmend Verwendung, da sich die Applikationsdauer der einzelnen Fraktionen deutlich verkuerzen laesst. Aufgrund der Unterschiede im Spektrum koennte die relative biologische Wirksamkeit (RBW) von FFF jedoch hoeher sein als bei konventioneller Technik (d.h. bei

  17. Isolation and characterization of ischemia-derived astrocytes (IDA with ability to transactivate quiescent astrocytes

    Directory of Open Access Journals (Sweden)

    Alejandro eVillarreal

    2016-06-01

    Full Text Available Reactive gliosis involving activation and proliferation of astrocytes and microglia, is a widespread but largely complex and graded glial response to brain injury. Astroglial population has a previously underestimated high heterogeneity with cells differing in their morphology, gene expression profile and response to injury. Here, we identified a subset of reactive astrocytes isolated from brain focal ischemic lesions that show several atypical characteristics. Ischemia-derived astrocytes (IDA were isolated from early ischemic penumbra and core. IDA did not originate from myeloid precursors, but rather from pre-existing local progenitors. Isolated IDA markedly differ from primary astrocytes, as they proliferate in vitro with high cell division rate, show increased migratory ability, have reduced replicative senescence and grow in the presence of macrophages within the limits imposed by the glial scar. Remarkably, IDA produce a conditioned medium that strongly induced activation on quiescent primary astrocytes and potentiated the neuronal death triggered by oxygen-glucose deprivation (OGD. When re-implanted into normal rat brains, eGFP-IDA migrated around the injection site and induced focal reactive gliosis. Inhibition of gamma secretases or culture on quiescent primary astrocytes monolayers facilitated IDA differentiation to astrocytes. We propose that IDA represent an undifferentiated, pro-inflammatory, highly replicative and migratory astroglial subtype emerging from the ischemic microenvironment that may contribute to the expansion of reactive gliosis.

  18. Therapeutic implications of colon cancer stem cells

    Institute of Scientific and Technical Information of China (English)

    Eros; Fabrizi; Simona; di; Martino; Federica; Pelacchi; Lucia; Ricci-Vitiani

    2010-01-01

    Colorectal cancer is the second most common cause of cancer-related death in many industrialized countries and is characterized by a heterogenic pool of cells with distinct differentiation patterns. Recently, the concept that cancer might arise from a rare population of cells with stem cell-like properties has received support with regard to several solid tumors, including colorectal cancer. According to the cancer stem cell hypothesis, cancer can be considered a disease in which mutations either convert no...

  19. Astrocyte Hypertrophy Contributes to Aberrant Neurogenesis after Traumatic Brain Injury

    Directory of Open Access Journals (Sweden)

    Clark Robinson

    2016-01-01

    Full Text Available Traumatic brain injury (TBI is a widespread epidemic with severe cognitive, affective, and behavioral consequences. TBIs typically result in a relatively rapid inflammatory and neuroinflammatory response. A major component of the neuroinflammatory response is astrocytes, a type of glial cell in the brain. Astrocytes are important in maintaining the integrity of neuronal functioning, and it is possible that astrocyte hypertrophy after TBIs might contribute to pathogenesis. The hippocampus is a unique brain region, because neurogenesis persists in adults. Accumulating evidence supports the functional importance of these newborn neurons and their associated astrocytes. Alterations to either of these cell types can influence neuronal functioning. To determine if hypertrophied astrocytes might negatively influence immature neurons in the dentate gyrus, astrocyte and newborn neurons were analyzed at 30 days following a TBI in mice. The results demonstrate a loss of radial glial-like processes extending through the granule cell layer after TBI, as well as ectopic growth and migration of immature dentate neurons. The results further show newborn neurons in close association with hypertrophied astrocytes, suggesting a role for the astrocytes in aberrant neurogenesis. Future studies are needed to determine the functional significance of these alterations to the astrocyte/immature neurons after TBI.

  20. Expression and activation by Epstein Barr virus of human endogenous retroviruses-W in blood cells and astrocytes: inference for multiple sclerosis.

    Directory of Open Access Journals (Sweden)

    Giuseppe Mameli

    Full Text Available BACKGROUND: Proposed co-factors triggering the pathogenesis of multiple sclerosis (MS are the Epstein Barr virus (EBV, and the potentially neuropathogenic MSRV (MS-associated retrovirus and syncytin-1, of the W family of human endogenous retroviruses. METHODOLOGY/PRINCIPAL FINDINGS: In search of links, the expression of HERV-W/MSRV/syncytin-1, with/without exposure to EBV or to EBV glycoprotein350 (EBVgp350, was studied on peripheral blood mononuclear cells (PBMC from healthy volunteers and MS patients, and on astrocytes, by discriminatory env-specific RT-PCR assays, and by flow cytometry. Basal expression of HERV-W/MSRV/syncytin-1 occurs in astrocytes and in monocytes, NK, and B, but not in T cells. This uneven expression is amplified in untreated MS patients, and dramatically reduced during therapy. In astrocytes, EBVgp350 stimulates the expression of HERV-W/MSRV/syncytin-1, with requirement of the NF-κB pathway. In EBVgp350-treated PBMC, MSRVenv and syncytin-1 transcription is activated in B cells and monocytes, but not in T cells, nor in the highly expressing NK cells. The latter cells, but not the T cells, are activated by proinflammatory cytokines. CONCLUSIONS/SIGNIFICANCE: In vitro EBV activates the potentially immunopathogenic and neuropathogenic HERV-W/MSRV/syncytin-1, in cells deriving from blood and brain. In vivo, pathogenic outcomes would depend on abnormal situations, as in late EBV primary infection, that is often symptomatic, or/and in the presence of particular host genetic backgrounds. In the blood, HERV-Wenv activation might induce immunopathogenic phenomena linked to its superantigenic properties. In the brain, toxic mechanisms against oligodendrocytes could be established, inducing inflammation, demyelination and axonal damage. Local stimulation by proinflammatory cytokines and other factors might activate further HERV-Ws, contributing to the neuropathogenity. In MS pathogenesis, a possible model could include EBV as

  1. Cell Phones and Cancer Risk

    Science.gov (United States)

    ... have the potential of accumulating more years of cell phone exposure than adults do. Thus far, the data from studies in children with cancer do not support this theory. The first published analysis came from a large ...

  2. An astrocyte regenerative response from vimentin-containing cells in the spinal cord of amyotrophic lateral sclerosis's disease-like transgenic (G93A SOD1) mice.

    Science.gov (United States)

    Zhou, Yiyi; Lu, Yi; Fang, Xin; Zhang, Jie; Li, Jiao; Li, Shujuan; Deng, Xia; Yu, Yaqing; Xu, Renshi

    2015-01-01

    The reason for regeneration in the adult spinal cord during motor neuron degeneration in amyotrophic lateral sclerosis (ALS) remains largely unknown. To this end, we studied the alteration of vimentin (a neural precursor cells marker in CNS)-containing cells (VCCs) in spinal cord during different stages of ALS used C57BL/6J G93A SOD1 transgenic mice mimicking ALS. Results showed that VCCs were mostly distributed in the ependymal zone (EZ) surrounding the central canal of spinal cord in SOD1 wild type mice; a few of VCCs were sparsely distributed in other regions. However, the number of VCCs significantly increased in the spinal cord during the onset and progression stages of ALS. They were extensively distributed in the EZ, the anterior, the lateral and the posterior horn of grey matter, particularly in the posterior horn region at the progression stage. A majority of VCCs in the anterior, the lateral and the posterior horn of grey matter (outside of EZ) generated astrocytes, but no neurons, oligodendrocytes and microgliocytes. Our results suggested that there was a potential astrocyte regenerative response to motor neuron degeneration in motor neurons-degenerated regions in the adult spinal cord during the onset and progression stages of ALS-like disease. The regenerative responses in the adult spinal cord of ALS-like mice may be a potential pathway in attempting to repair the degenerated motor neurons and restore the dysfunctional neural circuitry.

  3. New roles for astrocytes: the nightlife of an 'astrocyte'. La vida loca!

    Science.gov (United States)

    Horner, Philip J; Palmer, Theo D

    2003-11-01

    Like a newly popular nightspot, the biology of adult stem cells has emerged from obscurity to become one of the most lively new disciplines of the decade. The neurosciences have not escaped this trendy pastime and, from amid the noise and excitement, the astrocyte emerges as a beguiling companion to the adult neural stem cell. A once receding partner to neurons and oligodendrocytes, the astrocyte even takes on an alter ego of the stem cell itself (S. Goldman, this issue of TINS). Putting ego aside, the 'astrocyte' is also (and perhaps more importantly) an integral component of neural progenitor hotspots, where the craziness or 'la vida loca' of the nightlife might not be so wild when compared with our traditional understanding of the astrocyte. Here, astrocytes contribute to the instructive confluence of location, atmosphere and cellular neighbors that define the daily 'vida local' or everyday local life of an adult stem cell. This review discusses astrocytes as influential components in the local stem cell niche.

  4. Cancer Stem Cells in Osteosarcoma

    OpenAIRE

    Heymann, D; Brown, H K; Tellez-Gabriel, M.

    2017-01-01

    Osteosarcoma is the most common primary bone tumour in children and adolescents and advanced osteosarcoma patients with evidence of metastasis share a poor prognosis. Osteosarcoma frequently gains resistance to standard therapies highlighting the need for improved treatment regimens and identification of novel therapeutic targets. Cancer stem cells (CSC) represent a sub-type of tumour cells attributed to critical steps in cancer including tumour propagation, therapy resistance, recurrence and...

  5. Isolation of rare cancer cells from blood cells using dielectrophoresis.

    Science.gov (United States)

    Salmanzadeh, Alireza; Sano, Michael B; Shafiee, Hadi; Stremler, Mark A; Davalos, Rafael V

    2012-01-01

    In this study, we investigate the application of contactless dielectrophoresis (cDEP) for isolating cancer cells from blood cells. Devices with throughput of 0.2 mL/hr (equivalent to sorting 3×10(6) cells per minute) were used to trap breast cancer cells while allowing blood cells through. We have shown that this technique is able to isolate cancer cells in concentration as low as 1 cancer cell per 10(6) hematologic cells (equivalent to 1000 cancer cells in 1 mL of blood). We achieved 96% trapping of the cancer cells at 600 kHz and 300 V(RMS).

  6. Oxidative phosphorylation in cancer cells.

    Science.gov (United States)

    Solaini, Giancarlo; Sgarbi, Gianluca; Baracca, Alessandra

    2011-06-01

    Evidence suggests that mitochondrial metabolism may play a key role in controlling cancer cells life and proliferation. Recent evidence also indicates how the altered contribution of these organelles to metabolism and the resistance of cancer mitochondria against apoptosis-associated permeabilization are closely related. The hallmarks of cancer growth, increased glycolysis and lactate production in tumours, have raised attention due to recent observations suggesting a wide spectrum of oxidative phosphorylation deficit and decreased availability of ATP associated with malignancies and tumour cell expansion. More specifically, alteration in signal transduction pathways directly affects mitochondrial proteins playing critical roles in controlling the membrane potential as UCP2 and components of both MPTP and oxphos complexes, or in controlling cells life and death as the Bcl-2 proteins family. Moreover, since mitochondrial bioenergetics and dynamics, are also involved in processes of cells life and death, proper regulation of these mitochondrial functions is crucial for tumours to grow. Therefore a better understanding of the key pathophysiological differences between mitochondria in cancer cells and in their non-cancer surrounding tissue is crucial to the finding of tools interfering with these peculiar tumour mitochondrial functions and will disclose novel approaches for the prevention and treatment of malignant diseases. Here, we review the peculiarity of tumour mitochondrial bioenergetics and the mode it is linked to the cell metabolism, providing a short overview of the evidence accumulated so far, but highlighting the more recent advances.

  7. Innate Lymphoid Cells in Cancer.

    Science.gov (United States)

    Vallentin, Blandine; Barlogis, Vincent; Piperoglou, Christelle; Cypowyj, Sophie; Zucchini, Nicolas; Chéné, Matthieu; Navarro, Florent; Farnarier, Catherine; Vivier, Eric; Vély, Frédéric

    2015-10-01

    The world of lymphocytes has recently expanded. A group of cells, innate lymphoid cells (ILC), has been defined. It includes lymphoid cells that have been known for decades, such as natural killer (NK) cells and lymphoid tissue-inducer (LTi) cells. NK cells recognize a vast array of tumor cells, which they help to eliminate through cytotoxicity and the production of cytokines, such as IFNγ. Advances in our understanding of NK-cell biology have led to a growing interest in the clinical manipulation of these cells in cancer. The other ILCs are found mostly in the mucosae and mucosal-associated lymphoid tissues, where they rapidly initiate immune responses to pathogens without the need for specific sensitization. Here, we outline the basic features of ILCs and review the role of ILCs other than NK cells in cancer. Much of the role of these ILCs in cancer remains unknown, but several findings should lead to further efforts to dissect the contribution of different ILC subsets to the promotion, maintenance, or elimination of tumors at various anatomic sites. This will require the development of standardized reagents and protocols for monitoring the presence and function of ILCs in human blood and tissue samples.

  8. Peptide gH625 enters into neuron and astrocyte cell lines and crosses the blood–brain barrier in rats

    Directory of Open Access Journals (Sweden)

    Valiante S

    2015-03-01

    Full Text Available Salvatore Valiante,1,* Annarita Falanga,2,3,* Luisa Cigliano,1 Giuseppina Iachetta,1 Rosa Anna Busiello,1 Valeria La Marca,1 Massimiliano Galdiero,4 Assunta Lombardi,1 Stefania Galdiero1,2 1Department of Biology, 2Department of Pharmacy, 3DFM Scarl, University of Naples Federico II, 4Department of Experimental Medicine, II University of Naples, Naples, Italy *These authors contributed equally to this paper and are considered joint first authors Abstract: Peptide gH625, derived from glycoprotein H of herpes simplex virus type 1, can enter cells efficiently and deliver a cargo. Nanoparticles armed with gH625 are able to cross an in vitro model of the blood–brain barrier (BBB. In the present study, in vitro experiments were performed to investigate whether gH625 can enter and accumulate in neuron and astrocyte cell lines. The ability of gH625 to cross the BBB in vivo was also evaluated. gH625 was administered in vivo to rats and its presence in the liver and in the brain was detected. Within 3.5 hours of intravenous administration, gH625 can be found beyond the BBB in proximity to cell neurites. gH625 has no toxic effects in vivo, since it does not affect the maximal oxidative capacity of the brain or the mitochondrial respiration rate. Our data suggest that gH625, with its ability to cross the BBB, represents a novel nanocarrier system for drug delivery to the central nervous system. These results open up new possibilities for direct delivery of drugs into patients in the field of theranostics and might address the treatment of several human diseases. Keywords: drug delivery, neurons, astrocytes, blood–brain barrier, peptide

  9. Astrocyte Cultures Mimicking Brain Astrocytes in Gene Expression, Signaling, Metabolism and K(+) Uptake and Showing Astrocytic Gene Expression Overlooked by Immunohistochemistry and In Situ Hybridization.

    Science.gov (United States)

    Hertz, Leif; Chen, Ye; Song, Dan

    2017-01-01

    Based on differences in gene expression between cultured astrocytes and freshly isolated brain astrocytes it has been claimed that cultured astrocytes poorly reflect the characteristics of their in vivo counterparts. This paper shows that this is not the case with the cultures of mouse astrocytes we have used since 1978. The culture is prepared following guidelines provided by Drs. Monique Sensenbrenner and John Booher, with the difference that dibutyryl cyclic AMP is added to the culture medium from the beginning of the third week. This addition has only minor effects on glucose and glutamate metabolism, but it is crucial for effects by elevated K(+) concentrations and for Ca(2+) homeostasis, important aspects of astrocyte function. Work by Liang Peng and her colleagues has shown identity between not only gene expression but also drug-induced gene upregulations and editings in astrocytes cultured by this method and astrocytes freshly isolated from brains of drug-treated animals. Dr. Norenberg's laboratory has demonstrated identical upregulation of the cotransporter NKCC1 in ammonia-exposed astrocytes and rats with liver failure. Similarity between cultured and freshly isolated astrocytes has also been shown in metabolism, K(+) uptake and several aspects of signaling. However, others have shown that the gene for the glutamate transporter GLT1 is not expressed, and rat cultures show some abnormalities in K(+) effects. Nevertheless, the overall reliability of the cultured cells is important because immunohistochemistry and in situ hybridization poorly demonstrate many astrocytic genes, e.g., those of nucleoside transporters, and even microarray analysis of isolated cells can be misleading.

  10. In vitro differentiation of human adipose-derived adult stromal cells into neuron-like cells in hippocampal astrocyte conditioned medium

    Institute of Scientific and Technical Information of China (English)

    Xinchun Ye; Hongjun He; Feng Yang; Kepeng Zhao; Jun Yao; Bin Liu

    2006-01-01

    BACKGROUND: At present, researches on differentiating from human adipose-derived adult stromal cells (hADASC) to neuron-like cells are focus on inducing by artificial-synthetic compound solution;however,hippocampal astrocyte conditioned medium(HCAM)can induce in vitro differentiation from hADASC to neuron-like cells is still unclear.OBJECTIVE:To observe whether HCAM can induce in vitro differentiation from hADASC to neuron-like cells.DESIGN:Randomized control study.SETTING:Department of Neurology,Taixing People's Hospital;Central Laboratory,North China Coal Medical College.MATERIALS:Donor of adipose tissue was donated by female volunteers suffering from caesarean section in the department of obstetrics & gynecology in our hospital and aged 20-35 years. Adipose tissue was collected from subcutaneous tissue of abdomen during the operation.In addition.8 male newborn Wistar rats within 24 hours with average body mass of 20 g were provided by Animal Institute of Chinese Academy of Medical Sciences.Rabbit-anti-human Nestin polyclonal antibody.Rabbit-anti-human glial fibriliary acidic protein (GFAP)polyclonal antibody, rabbit-anti-human neuro-specific enolase polyclonal antibody and mouse-anti-human microtubal associated protein 2(MAP-2)polyclonal antibody were provided by Wuhan Boster Company.METHODS:The experiment was carried out in the Central Laboratory of North China Coal Medical College from October 2004 to June 2005.hADASC was cultured with HCAM and its growth and morphological changes were observed under inverted phase contrast microscope.Immunocytochemistry.immunofluorescence and Western blotting were used to evaluate the expressions of Nestin,which was a specific sign of nerve precursor,neuro-specific enolase and MAP-2,which was a specific sign of nerve cell,and GFAP,which was a specific sign of neuroglial cells.MAIN OUTCOME MEASURES:Nestin,which was a specific sign of nerve precursor,neuro-specific enolase and MAP-2,which was a specific sign of nerve cell

  11. Do Cell Phones Cause Cancer?

    CERN Document Server

    Leikind, Bernard

    2010-01-01

    Do cell phones, household electrical power wiring or appliance, or high voltage power lines cause cancer? Fuggedaboudit! No way! When pigs fly! When I'm the Pope! Don't text while you're driving, however, or eat your cell phone. All organisms absorb microwave radiation directly as thermal energy. In living organisms, the organisms' thermal control systems, including the blood flow, and various cooling mechanisms, such as sweating in humans, that work to maintain a stable body temperature rapidly transfer the absorbed energy to the environment. Any temperature rise is small or even unobserved. Any proposed mechanism by which cell phone radiation might cause cancer must begin with this fact. But the amount of radiation absorbed from a cell phone is less than that produced by normal metabolic processes, and much less than that produced by, for example, exercise. None of these normal metabolic processes cause cancer. Therefore, the much smaller amounts of energy from cell phones doesn't cause cancer either. All f...

  12. Sodium signaling and astrocyte energy metabolism.

    Science.gov (United States)

    Chatton, Jean-Yves; Magistretti, Pierre J; Barros, L Felipe

    2016-10-01

    The Na(+) gradient across the plasma membrane is constantly exploited by astrocytes as a secondary energy source to regulate the intracellular and extracellular milieu, and discard waste products. One of the most prominent roles of astrocytes in the brain is the Na(+) -dependent clearance of glutamate released by neurons during synaptic transmission. The intracellular Na(+) load collectively generated by these processes converges at the Na,K-ATPase pump, responsible for Na(+) extrusion from the cell, which is achieved at the expense of cellular ATP. These processes represent pivotal mechanisms enabling astrocytes to increase the local availability of metabolic substrates in response to neuronal activity. This review presents basic principles linking the intracellular handling of Na(+) following activity-related transmembrane fluxes in astrocytes and the energy metabolic pathways involved. We propose a role of Na(+) as an energy currency and as a mediator of metabolic signals in the context of neuron-glia interactions. We further discuss the possible impact of the astrocytic syncytium for the distribution and coordination of the metabolic response, and the compartmentation of these processes in cellular microdomains and subcellular organelles. Finally, we illustrate future avenues of investigation into signaling mechanisms aimed at bridging the gap between Na(+) and the metabolic machinery. GLIA 2016;64:1667-1676.

  13. Sodium signaling and astrocyte energy metabolism

    KAUST Repository

    Chatton, Jean-Yves

    2016-03-31

    The Na+ gradient across the plasma membrane is constantly exploited by astrocytes as a secondary energy source to regulate the intracellular and extracellular milieu, and discard waste products. One of the most prominent roles of astrocytes in the brain is the Na+-dependent clearance of glutamate released by neurons during synaptic transmission. The intracellular Na+ load collectively generated by these processes converges at the Na,K-ATPase pump, responsible for Na+ extrusion from the cell, which is achieved at the expense of cellular ATP. These processes represent pivotal mechanisms enabling astrocytes to increase the local availability of metabolic substrates in response to neuronal activity. This review presents basic principles linking the intracellular handling of Na+ following activity-related transmembrane fluxes in astrocytes and the energy metabolic pathways involved. We propose a role of Na+ as an energy currency and as a mediator of metabolic signals in the context of neuron-glia interactions. We further discuss the possible impact of the astrocytic syncytium for the distribution and coordination of the metabolic response, and the compartmentation of these processes in cellular microdomains and subcellular organelles. Finally, we illustrate future avenues of investigation into signaling mechanisms aimed at bridging the gap between Na+ and the metabolic machinery. © 2016 Wiley Periodicals, Inc.

  14. Cancer stem cells and metastasis.

    Science.gov (United States)

    Sampieri, Katia; Fodde, Riccardo

    2012-06-01

    Cancer stem cells (CSCs) represent a subpopulation of tumour cells endowed with self-renewal and multi-lineage differentiation capacity but also with an innate resistance to cytotoxic agents, a feature likely to pose major clinical challenges towards the complete eradication of minimal residual disease in cancer patients. Operationally, CSCs are defined by their tumour-propagating ability when serially transplanted into immune-compromised mice and by their capacity to fully recapitulate the original heterogeneity of cell types observed in the primary lesions they are derived from. CSCs were first identified in haematopoietic malignancies and later in a broad spectrum of solid tumours including those of the breast, colon and brain. Notably, several CSC characteristics are relevant to metastasis, such as motility, invasiveness and, as mentioned above, resistance to DNA damage-induced apoptosis. Here, we have reviewed the current literature on the relation between CSCs and metastasis formation. Preliminary studies on cancer cell lines and patient-derived material suggest a rate-limiting role for stem-like cells in the processes of tumour cell dissemination and metastasis formation. However, additional studies are needed to deliver formal proof of their identity as the cell of origin of recurrences at distant organ sites. Nevertheless, several studies have already provided pre-clinical evidence of the efficacy of novel therapies directed against disseminated CSCs.

  15. Invasive cancer cells and metastasis

    Science.gov (United States)

    Mierke, Claudia Tanja

    2013-12-01

    The physics of cancer is a relatively new emerging field of cancer research. In the last decade it has become a focus of biophysical research as well as becoming a novel focus for classical cancer research. This special section of Physical Biology focusing on invasive cancer cells and metastasis (physical oncology) will give greater insight into the different subfields where physical approaches are being applied to cancer research. This focus on the physical aspects of cancer is necessary because novel approaches in the field of genomics and proteomics have not altered the field of cancer research dramatically, due to the fact that few breakthroughs have been made. It is still not understood why some primary tumors metastasize and thus have a worse outcome compared to others that do not metastasize. As biophysicists, we and others suggest that the mechanical properties of the cancer cells, which possess the ability to transmigrate, are quite different compared to non-metastatic and non-invasive cancer cells. Furthermore, we hypothesize that these cancer cells undergo a selection process within the primary tumor that enables them to weaken their cell-cell adhesions and to alter their cell-matrix adhesions in order to be able to cross the outermost boundary of the primary tumor, as well as the surrounding basement membrane, and to invade the connective tissue. This prerequisite may also help the cancer cells to enter blood or lymph vessels, get transported with the vessel flow and form secondary tumors either within the vessel, directly on the endothelium, or in a different organ after crossing the endothelial lining a second time. This special section begins with a paper by Mark F Coughlin and Jeffrey J Fredberg on the changes in cytoskeletal dynamics and nonlinear rheology due to the metastatic capability of cancer cells from different cancer tissue types such as skin, bladder, prostate and kidney [1]. The hypothesis was that the metastatic outcome is impacted by

  16. In vitro study of uptake and synthesis of creatine and its precursors by cerebellar granule cells and astrocytes suggests some hypotheses on the physiopathology of the inherited disorders of creatine metabolism

    Directory of Open Access Journals (Sweden)

    Carducci Claudia

    2012-04-01

    Full Text Available Abstract Background The discovery of the inherited disorders of creatine (Cr synthesis and transport in the last few years disclosed the importance of blood Cr supply for the normal functioning of the brain. These putatively rare diseases share a common pathogenetic mechanism (the depletion of brain Cr and similar phenotypes characterized by mental retardation, language disturbances, seizures and movement disorders. In the effort to improve our knowledge on the mechanisms regulating Cr pool inside the nervous tissue, Cr transport and synthesis and related gene transcripts were explored in primary cultures of rat cerebellar granule cells and astrocytes. Methods Cr uptake and synthesis were explored in vitro by incubating monotypic primary cultures of rat type I astrocytes and cerebellar granule cells with: a D3-Creatine (D3Cr and D3Cr plus β-guanidinopropionate (GPA, an inhibitor of Cr transporter, and b labelled precursors of Guanidinoacetate (GAA and Cr (Arginine, Arg; Glycine, Gly. Intracellular D3Cr and labelled GAA and Cr were assessed by ESI-MS/MS. Creatine transporter (CT1, L-arginine:glycine amidinotransferase (AGAT, and S-adenosylmethionine:guanidinoacetate N-methyltransferase (GAMT gene expression was assessed in the same cells by real time PCR. Results D3Cr signal was extremely high in cells incubated with this isotope (labelled/unlabelled Cr ratio reached about 10 and 122, respectively in cerebellar granule cells and astrocytes and was reduced by GPA. Labelled Arg and Gly were taken up by the cells and incorporated in GAA, whose concentration paralleled that of these precursors both in the extracellular medium and inside the cells (astrocytes. In contrast, the increase of labelled Cr was relatively much more limited since labelled Cr after precursors' supplementation did not exceed 2,7% (cerebellar granule cells and 21% (astrocytes of unlabelled Cr. Finally, AGAT, GAMT and SLC6A8 were expressed in both kind of cells. Conclusions Our

  17. Cancer stem cells: therapeutic implications and perspectives in cancer therapy

    Directory of Open Access Journals (Sweden)

    Lu Han

    2013-04-01

    Full Text Available The cancer stem cell (CSC theory is gaining increasing attention from researchers and has become an important focus of cancer research. According to the theory, a minority population of cancer cells is capable of self-renewal and generation of differentiated progeny, termed cancer stem cells (CSCs. Understanding the properties and characteristics of CSCs is key to future study on cancer research, such as the isolation and identification of CSCs, the cancer diagnosis, and the cancer therapy. Standard oncology treatments, such as chemotherapy, radiotherapy and surgical resection, can only shrink the bulk tumor and the tumor tends to relapse. Thus, therapeutic strategies that focus on targeting CSCs and their microenvironmental niche address the ineffectiveness of traditional cancer therapies to eradicate the CSCs that otherwise result in therapy resistance. The combined use of traditional therapies with targeted CSC-specific agents may target the whole cancer and offer a promising strategy for lasting treatment and even cure.

  18. Notch signaling in cancer stem cells.

    Science.gov (United States)

    Wang, Jialiang; Sullenger, Bruce A; Rich, Jeremy N

    2012-01-01

    Subpopulations of cancer cells with stem cell-like characteristics, termed cancer stem cells, have been identified in a wide range of human cancers. Cancer stem cells are defined by their ability to self-renew as well as recapitulate the original heterogeneity of cancer cells in culture and in serial xenotransplants. Not only are cancer stem cells highly tumorigenic, but these cells are implicated in tumor resistance to conventional chemotherapy and radiotherapy, thus highlighting their significance as therapeutic targets. Considerable similarities have been found between cancer stem cells and normal stem cells on their dependence on certain signaling pathways. More specifically, the core stem cell signaling pathways, such as the Wnt, Notch and Hedgehog pathways, also critically regulate the self-renewal and survival of cancer stem cells. While the oncogenic functions of Notch pathway have been well documented, its role in cancer stem cells is just emerging. In this chapter, we will discuss recent advances in cancer stem cell research and highlight the therapeutic potential of targeting Notch in cancer stem cells.

  19. The role of dendritic cells in cancer

    DEFF Research Database (Denmark)

    Hansen, Morten; Andersen, Mads Hald

    2017-01-01

    Though present in low numbers, dendritic cells (DCs) are recognized as major players in the control of cancer by adaptive immunity. The roles of cytotoxic CD8+ T-cells and Th1 helper CD4+ T-cells are well-documented in murine models of cancer and associated with a profound prognostic impact when...... treatment regimens against cancer....

  20. Down-Regulation of Neurocan Expression in Reactive Astrocytes Promotes Axonal Regeneration and Facilitates the Neurorestorative Effects of Bone Marrow Stromal Cells in the Ischemic Rat Brain

    Institute of Scientific and Technical Information of China (English)

    LI HONG SHEN; YI LI; QI GAO; SMITA SAVANT-BHONSALE; MICHAEL CHOPP

    2008-01-01

    脑卒中后缺血组织边界形成胶质疤痕,抑制轴突再生.神经蛋白聚糖是一种轴突延长抑制分子,在卒中后胶质疤痕中表达上调.骨髓基质干细胞(BMSCs)可降低胶质疤痕壁的厚度,加速缺血周边区的轴突重塑.为了进一步明确BMSCs在轴突再生中的作用及机制,本文重点研究脑缺血组织中BMSCs对神经蛋白聚糖表达的作用.31只成年雄性Wistar大鼠大脑中动脉阻塞(MCAo)2 h,24 h后从中选择16只给予尾静脉注射3 × 106鼠BMSCs(BMSCs组),15只注射磷酸盐缓冲生理盐水(对照组).缺血后8 d处死实验大鼠,免疫染色表明反应性星形胶质细胞是神经蛋白聚糖的原始来源,且BMSCs组缺血半暗带脑组织的神经聚糖表达明显低于对照组,生长相关蛋白43表达高于对照组,这在蛋白印迹分析中得到确认.为了进一步检测BMSCs在星形胶质细胞神经蛋白聚糖表达中的作用,用激光捕获显微切割法从缺血周边区收集单纯的反应性星形胶质细胞.BMSCs组的神经蛋白聚糖基因表达明显下调(n=4/组).原代培养的星形胶质细胞也表现出相同改变,糖氧剥离的星形胶质细胞再给氧时与BMSCs共培养会抑制神经蛋白聚糖基因的表达上调(n=3/组).本研究表明BMSCs通过下调梗死周边星形胶质细胞中神经蛋白聚糖的表达来促进轴突再生.%The glial scar, a primarily astrocytic structure bordering the infarct tissue inhibits axonal regeneration after stroke. Neurocan, an axonal extension inhibitory molecule, is upregulated in the scar region after stroke. Bone marrow stromal cells (BMSCs) reduce the thickness of glial scar wall and facilitate axonal remodeling in the ischemic boundary zone. To further clarify the role of BMSCs in axonal regeneration and its underlying mechanism, the current study focused on the effect of BMSCs on neurocan expression in the ischemic brain. Thirty-one adult male Wistar rats were subjected to 2 h of middle

  1. A stereological analysis of NPY, POMC, Orexin, GFAP astrocyte, and Iba1 microglia cell number and volume in diet-induced obese male mice.

    Science.gov (United States)

    Lemus, Moyra B; Bayliss, Jacqueline A; Lockie, Sarah H; Santos, Vanessa V; Reichenbach, Alex; Stark, Romana; Andrews, Zane B

    2015-05-01

    The hypothalamic arcuate nucleus (ARC) contains 2 key neural populations, neuropeptide Y (NPY) and proopiomelanocortin (POMC), and, together with orexin neurons in the lateral hypothalamus, plays an integral role in energy homeostasis. However, no studies have examined total neuronal number and volume after high-fat diet (HFD) exposure using sophisticated stereology. We used design-based stereology to estimate NPY and POMC neuronal number and volume, as well as glial fibrillary acidic protein (astrocyte marker) and ionized calcium-binding adapter molecule 1 (microglia marker) cell number in the ARC; as well as orexin neurons in the lateral hypothalamus. Stereological analysis indicated approximately 8000 NPY and approximately 9000 POMC neurons in the ARC, and approximately 7500 orexin neurons in the lateral hypothalamus. HFD exposure did not affect total neuronal number in any population. However, HFD significantly increased average NPY cell volume and affected NPY and POMC cell volume distribution. HFD reduced orexin cell volume but had a bimodal effect on volume distribution with increased cells at relatively small volumes and decreased cells with relatively large volumes. ARC glial fibrillary acidic protein cells increased after 2 months on a HFD, although no significant difference after 6 months on chow diet or HFD was observed. No differences in ARC ionized calcium-binding adapter molecule 1 cell number were observed in any group. Thus, HFD affects ARC NPY or POMC neuronal cell volume number not cell number. Our results demonstrate the importance of stereology to perform robust unbiased analysis of cell number and volume. These data should be an empirical baseline reference to which future studies are compared.

  2. Astrocytes Control Neuronal Excitability in the Nucleus Accumbens

    Directory of Open Access Journals (Sweden)

    Tommaso Fellin

    2007-01-01

    Full Text Available Though accumulating evidence shows that the metabotropic glutamate receptor 5 (mGluR5 mediates some of the actions of extracellular glutamate after cocaine use, the cellular events underlying this action are poorly understood. In this review, we will discuss recent results showing that mGluR5 receptors are key regulators of astrocyte activity. Synaptic release of glutamate activates mGluR5 expressed in perisynaptic astrocytes and generates intense Ca2+ signaling in these cells. Ca2+ oscillations, in turn, trigger the release from astrocytes of the gliotransmitter glutamate, which modulates neuronal excitability by activating NMDA receptors. By integrating these results with the most recent evidence demonstrating the importance of astrocytes in the regulation of neuronal excitability, we propose that astrocytes are involved in mediating some of the mGluR5-dependent drug-induced behaviors.

  3. Superantigen presenting capacity of human astrocytes

    DEFF Research Database (Denmark)

    Hassan-Zahraee, M; Ladiwala, U; Lavoie, P M;

    2000-01-01

    We found that human fetal astrocytes (HFA) are able to support superantigen (SAG) staphylococcal enterotoxin B (SEB) and toxic shock syndrome toxin-1 (TSST-1)-induced activation of immediately ex vivo allogenic human CD4 T cells. Using radiolabelled toxins, we demonstrate that both SEB and TSST-1...

  4. The relationship of cancer stem cells in urological cancers

    Directory of Open Access Journals (Sweden)

    Marta Pokrywczyńska

    2013-08-01

    Full Text Available Numerous studies are ongoing to identify and isolate cancer stem cells from cancers of genito-urinary tracts. Better understanding of their role in prostate, urothelial and kidney cancer origin, growth and progression opens new pathways in development of more effective treatment methods. However there are still many issues before advances in this field can be introduced for clinical application. This review addresses current achievements in cancer stem cells research in uro-oncology.

  5. Synaptic modulation by astrocytes via Ca2+-dependent glutamate release.

    Science.gov (United States)

    Santello, M; Volterra, A

    2009-01-12

    In the past 15 years the classical view that astrocytes play a relatively passive role in brain function has been overturned and it has become increasingly clear that signaling between neurons and astrocytes may play a crucial role in the information processing that the brain carries out. This new view stems from two seminal observations made in the early 1990s: 1. astrocytes respond to neurotransmitters released during synaptic activity with elevation of their intracellular Ca2+ concentration ([Ca2+]i); 2. astrocytes release chemical transmitters, including glutamate, in response to [Ca2+]i elevations. The simultaneous recognition that astrocytes sense neuronal activity and release neuroactive agents has been instrumental for understanding previously unknown roles of these cells in the control of synapse formation, function and plasticity. These findings open a conceptual revolution, leading to rethink how brain communication works, as they imply that information travels (and is processed) not just in the neuronal circuitry but in an expanded neuron-glia network. In this review we critically discuss the available information concerning: 1. the characteristics of the astrocytic Ca2+ responses to synaptic activity; 2. the basis of Ca2+-dependent glutamate exocytosis from astrocytes; 3. the modes of action of astrocytic glutamate on synaptic function.

  6. Simultaneous neuron- and astrocyte-specific fluorescent marking

    Energy Technology Data Exchange (ETDEWEB)

    Schulze, Wiebke [Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Hayata-Takano, Atsuko [Molecular Research Center for Children' s Mental Development, United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University and University of Fukui, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Kamo, Toshihiko [Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Nakazawa, Takanobu, E-mail: takanobunakazawa-tky@umin.ac.jp [iPS Cell-based Research Project on Brain Neuropharmacology and Toxicology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Nagayasu, Kazuki [iPS Cell-based Research Project on Brain Neuropharmacology and Toxicology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Kasai, Atsushi; Seiriki, Kaoru [Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Interdisciplinary Program for Biomedical Sciences, Institute for Academic Initiatives, Osaka University, 1-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Shintani, Norihito [Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Ago, Yukio [Laboratory of Medicinal Pharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Farfan, Camille [Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); and others

    2015-03-27

    Systematic and simultaneous analysis of multiple cell types in the brain is becoming important, but such tools have not yet been adequately developed. Here, we aimed to generate a method for the specific fluorescent labeling of neurons and astrocytes, two major cell types in the brain, and we have developed lentiviral vectors to express the red fluorescent protein tdTomato in neurons and the enhanced green fluorescent protein (EGFP) in astrocytes. Importantly, both fluorescent proteins are fused to histone 2B protein (H2B) to confer nuclear localization to distinguish between single cells. We also constructed several expression constructs, including a tandem alignment of the neuron- and astrocyte-expression cassettes for simultaneous labeling. Introducing these vectors and constructs in vitro and in vivo resulted in cell type-specific and nuclear-localized fluorescence signals enabling easy detection and distinguishability of neurons and astrocytes. This tool is expected to be utilized for the simultaneous analysis of changes in neurons and astrocytes in healthy and diseased brains. - Highlights: • We develop a method for the specific fluorescent labeling of neurons and astrocytes. • Neuron-specific labeling is achieved using Scg10 and synapsin promoters. • Astrocyte-specific labeling is generated using the minimal GFAP promoter. • Nuclear localization of fluorescent proteins is achieved with histone 2B protein.

  7. Curcumin alleviates oxidative stress and mitochondrial dysfunction in astrocytes.

    Science.gov (United States)

    Daverey, Amita; Agrawal, Sandeep K

    2016-10-01

    Oxidative stress plays a critical role in various neurodegenerative diseases, thus alleviating oxidative stress is a potential strategy for therapeutic intervention and/or prevention of neurodegenerative diseases. In the present study, alleviation of oxidative stress through curcumin is investigated in A172 (human glioblastoma cell line) and HA-sp (human astrocytes cell line derived from the spinal cord) astrocytes. H2O2 was used to induce oxidative stress in astrocytes (A172 and HA-sp). Data show that H2O2 induces activation of astrocytes in dose- and time-dependent manner as evident by increased expression of GFAP in A172 and HA-sp cells after 24 and 12h respectively. An upregulation of Prdx6 was also observed in A172 and HA-sp cells after 24h of H2O2 treatment as compared to untreated control. Our data also showed that curcumin inhibits oxidative stress-induced cytoskeleton disarrangement, and impedes the activation of astrocytes by inhibiting upregulation of GFAP, vimentin and Prdx6. In addition, we observed an inhibition of oxidative stress-induced inflammation, apoptosis and mitochondria fragmentation after curcumin treatment. Therefore, our results suggest that curcumin not only protects astrocytes from H2O2-induced oxidative stress but also reverses the mitochondrial damage and dysfunction induced by oxidative stress. This study also provides evidence for protective role of curcumin on astrocytes by showing its effects on attenuating reactive astrogliosis and inhibiting apoptosis.

  8. Maternal diet and risk of astrocytic glioma in children: a report from the Childrens Cancer Group (United States and Canada)

    Science.gov (United States)

    Bunin, G R; Kuijten, R R; Boesel, C P; Buckley, J D; Meadows, A T

    1994-03-01

    N-nitroso compounds and their precursors, nitrites and nitrates, have been hypothesized as risk factors, and vitamins C and E, which inhibit N-nitroso formation, as protective factors for brain tumors. A case-control study of maternal diet during pregnancy and risk of astrocytoma, the most common childhood brain tumor, was conducted by the Childrens Cancer Group. The study included 155 cases under age six at diagnosis and the same number of matched controls selected by random-digit dialing. A trend was observed for consumption of cured meats, which contain preformed nitrosamines (a class of N-nitroso compounds) and their precursors (adjusted odds ratio [OR] for highest quartile of intake relative to lowest = 1.7, P trend = 0.10). However, no strong trends were observed for nitrosamine (OR = 0.8, P = 0.60); nitrite (OR = 1.3, P = 0.54); nitrate (OR = 0.7, P = 0.43); vitamin C (OR = 0.7, P = 0.37); or vitamin E (OR = 0.7, P = 0.48). Iron supplements were associated with a significant decrease in risk (OR = 0.5, 95 percent confidence interval = 0.3-0.8). The effect of several dietary factors differed by income level, making interpretation of the results difficult. Future research should investigate the effect of dietary components not assessed in this study, as these may explain the disparate effects by income level. The results of this study provide limited support for the nitrosamine hypothesis.

  9. Colorectal Cancer Stem Cells and Cell Death

    Energy Technology Data Exchange (ETDEWEB)

    Catalano, Veronica [Department of Surgical and Oncological Sciences, University of Palermo, Via Liborio Giuffrè 5, 90127 Palermo, PA (Italy); Gaggianesi, Miriam [Department of Surgical and Oncological Sciences, University of Palermo, Via Liborio Giuffrè 5, 90127 Palermo, PA (Italy); Department of Cellular and Molecular Oncology, IRCCS Fondazione Salvatore Maugeri, Via Salvatore Maugeri, 27100 Pavia, PV (Italy); Spina, Valentina; Iovino, Flora [Department of Surgical and Oncological Sciences, University of Palermo, Via Liborio Giuffrè 5, 90127 Palermo, PA (Italy); Dieli, Francesco [Departement of Biopathology and Medicine Biotechnologies, University of Palermo, Via Liborio Giuffrè 5, 90127 Palermo, PA (Italy); Stassi, Giorgio, E-mail: giorgio.stassi@unipa.it [Department of Surgical and Oncological Sciences, University of Palermo, Via Liborio Giuffrè 5, 90127 Palermo, PA (Italy); Department of Cellular and Molecular Oncology, IRCCS Fondazione Salvatore Maugeri, Via Salvatore Maugeri, 27100 Pavia, PV (Italy); Todaro, Matilde [Department of Surgical and Oncological Sciences, University of Palermo, Via Liborio Giuffrè 5, 90127 Palermo, PA (Italy)

    2011-04-11

    Nowadays it is reported that, similarly to other solid tumors, colorectal cancer is sustained by a rare subset of cancer stem–like cells (CSCs), which survive conventional anticancer treatments, thanks to efficient mechanisms allowing escape from apoptosis, triggering tumor recurrence. To improve patient outcomes, conventional anticancer therapies have to be replaced with specific approaches targeting CSCs. In this review we provide strong support that BMP4 is an innovative therapeutic approach to prevent colon cancer growth increasing differentiation markers expression and apoptosis. Recent data suggest that in colorectal CSCs, protection from apoptosis is achieved by interleukin-4 (IL-4) autocrine production through upregulation of antiapoptotic mediators, including survivin. Consequently, IL-4 neutralization could deregulate survivin expression and localization inducing chemosensitivity of the colon CSCs pool.

  10. Glutathione in Cancer Cell Death

    Directory of Open Access Journals (Sweden)

    Jose M. Estrela

    2011-03-01

    Full Text Available Glutathione (L-γ-glutamyl-L-cysteinyl-glycine; GSH in cancer cells is particularly relevant in the regulation of carcinogenic mechanisms; sensitivity against cytotoxic drugs, ionizing radiations, and some cytokines; DNA synthesis; and cell proliferation and death. The intracellular thiol redox state (controlled by GSH is one of the endogenous effectors involved in regulating the mitochondrial permeability transition pore complex and, in consequence, thiol oxidation can be a causal factor in the mitochondrion-based mechanism that leads to cell death. Nevertheless GSH depletion is a common feature not only of apoptosis but also of other types of cell death. Indeed rates of GSH synthesis and fluxes regulate its levels in cellular compartments, and potentially influence switches among different mechanisms of death. How changes in gene expression, post-translational modifications of proteins, and signaling cascades are implicated will be discussed. Furthermore, this review will finally analyze whether GSH depletion may facilitate cancer cell death under in vivo conditions, and how this can be applied to cancer therapy.

  11. Glutathione in Cancer Cell Death

    Energy Technology Data Exchange (ETDEWEB)

    Ortega, Angel L. [Department of Physiology, Faculty of Medicine and Odontology, University of Valencia, 17 Av. Blasco Ibanez, 46010 Valencia (Spain); Mena, Salvador [Green Molecular SL, Pol. Ind. La Coma-Parc Cientific, 46190 Paterna, Valencia (Spain); Estrela, Jose M., E-mail: jose.m.estrela@uv.es [Department of Physiology, Faculty of Medicine and Odontology, University of Valencia, 17 Av. Blasco Ibanez, 46010 Valencia (Spain)

    2011-03-11

    Glutathione (L-γ-glutamyl-L-cysteinyl-glycine; GSH) in cancer cells is particularly relevant in the regulation of carcinogenic mechanisms; sensitivity against cytotoxic drugs, ionizing radiations, and some cytokines; DNA synthesis; and cell proliferation and death. The intracellular thiol redox state (controlled by GSH) is one of the endogenous effectors involved in regulating the mitochondrial permeability transition pore complex and, in consequence, thiol oxidation can be a causal factor in the mitochondrion-based mechanism that leads to cell death. Nevertheless GSH depletion is a common feature not only of apoptosis but also of other types of cell death. Indeed rates of GSH synthesis and fluxes regulate its levels in cellular compartments, and potentially influence switches among different mechanisms of death. How changes in gene expression, post-translational modifications of proteins, and signaling cascades are implicated will be discussed. Furthermore, this review will finally analyze whether GSH depletion may facilitate cancer cell death under in vivo conditions, and how this can be applied to cancer therapy.

  12. Prostate Cancer Stem Cells: Research Advances.

    Science.gov (United States)

    Jaworska, Dagmara; Król, Wojciech; Szliszka, Ewelina

    2015-01-01

    Cancer stem cells have been defined as cells within a tumor that possesses the capacity to self-renew and to cause the heterogeneous lineages of cancer cells that comprise the tumor. Experimental evidence showed that these highly tumorigenic cells might be responsible for initiation and progression of cancer into invasive and metastatic disease. Eradicating prostate cancer stem cells, the root of the problem, has been considered as a promising target in prostate cancer treatment to improve the prognosis for patients with advanced stages of the disease.

  13. Prostate Cancer Stem Cells: Research Advances

    Directory of Open Access Journals (Sweden)

    Dagmara Jaworska

    2015-11-01

    Full Text Available Cancer stem cells have been defined as cells within a tumor that possesses the capacity to self-renew and to cause the heterogeneous lineages of cancer cells that comprise the tumor. Experimental evidence showed that these highly tumorigenic cells might be responsible for initiation and progression of cancer into invasive and metastatic disease. Eradicating prostate cancer stem cells, the root of the problem, has been considered as a promising target in prostate cancer treatment to improve the prognosis for patients with advanced stages of the disease.

  14. Astrocyte proliferation following stroke in the mouse depends on distance from the infarct.

    Directory of Open Access Journals (Sweden)

    George E Barreto

    Full Text Available Reactive gliosis is a hallmark of brain pathology and the injury response, yet the extent to which astrocytes proliferate, and whether this is central to astrogliosis is still controversial. We determined the fraction of mature astrocytes that proliferate in a mouse stroke model using unbiased stereology as a function of distance from the infarct edge. Cumulatively 11.1±1.2% of Aldh1l1(+ astrocytes within 400 µm in the cortical penumbra incorporate BrdU in the first week following stroke, while the overall number of astrocytes does not change. The number of astrocytes proliferating fell sharply with distance with more than half of all proliferating astrocytes found within 100 µm of the edge of the infarct. Despite extensive cell proliferation primarily of microglia and neutrophils/monocytes in the week following stroke, few mature astrocytes re-enter cell cycle, and these are concentrated close to the infarct boundary.

  15. Astrocyte proliferation following stroke in the mouse depends on distance from the infarct.

    Science.gov (United States)

    Barreto, George E; Sun, Xiaoyun; Xu, Lijun; Giffard, Rona G

    2011-01-01

    Reactive gliosis is a hallmark of brain pathology and the injury response, yet the extent to which astrocytes proliferate, and whether this is central to astrogliosis is still controversial. We determined the fraction of mature astrocytes that proliferate in a mouse stroke model using unbiased stereology as a function of distance from the infarct edge. Cumulatively 11.1±1.2% of Aldh1l1(+) astrocytes within 400 µm in the cortical penumbra incorporate BrdU in the first week following stroke, while the overall number of astrocytes does not change. The number of astrocytes proliferating fell sharply with distance with more than half of all proliferating astrocytes found within 100 µm of the edge of the infarct. Despite extensive cell proliferation primarily of microglia and neutrophils/monocytes in the week following stroke, few mature astrocytes re-enter cell cycle, and these are concentrated close to the infarct boundary.

  16. [In vitro co-cultivation of Toxoplasma gondii tachyzoites with rat brain astrocytes].

    Science.gov (United States)

    Li, Dong-na; Liang, You-sheng; Zhou, Yong-hua; Zhang, Huan-xiang; Sheng, Hai-ying; Luo, Wei; Gong, Wei; Zhuge, Hong-xiang

    2010-08-01

    Purified astrocytes were cultured in plates. When astrocytes grew over 80% of the plate, tachyzoites of Toxoplasma gondii RH strain were added for co-culture. In the period of 0-72 h, change of the astrocytes and tachyzoites was observed after Giemsa staining. In 0-48 h, monodansylcadaverine (MDC) was used to study the action of autophagy in the process of tachyzoites invading astrocytes. At 1 h co-culture, tachyzoites had entered in astrocytes and the autophagosomes appeared. At 4 h, the autophagosomes increased pronouncedly. However, after 12 h, number of autophagosomes considerably decreased and damage of the cells occurred. 48 h later, autophagosomes disappeared and more astrocytes were destroyed. At 72 h most cells destroyed and tachyzoites were released. The result showed that autophagy is inhibited when the astrocytes were in vitro infected by tachyzoites.

  17. Colocalization of aromatase in spinal cord astrocytes: differences in expression and relationship to mechanical and thermal hyperalgesia in murine models of a painful and a non-painful bone tumor.

    Science.gov (United States)

    O'Brien, E E; Smeester, B A; Michlitsch, K S; Lee, J-H; Beitz, A J

    2015-08-20

    While spinal cord astrocytes play a key role in the generation of cancer pain, there have been no studies that have examined the relationship of tumor-induced astrocyte activation and aromatase expression during the development of cancer pain. Here, we examined tumor-induced mechanical hyperalgesia and cold allodynia, and changes in Glial fibrillary acid protein (GFAP) and aromatase expression in murine models of painful and non-painful bone cancer. We demonstrate that implantation of fibrosarcoma cells, but not melanoma cells, produces robust mechanical hyperalgesia and cold allodynia in tumor-bearing mice compared to saline-injected controls. Secondly, this increase in mechanical hyperalgesia and cold allodynia is mirrored by significant increases in both spinal astrocyte activity and aromatase expression in the dorsal horn of fibrosarcoma-bearing mice. Importantly, we show that aromatase is only found within a subset of astrocytes and not in neurons in the lumbar spinal cord. Finally, administration of an aromatase inhibitor reduced tumor-induced hyperalgesia in fibrosarcoma-bearing animals. We conclude that a painful fibrosarcoma tumor induces a significant increase in spinal astrocyte activation and aromatase expression and that the up-regulation of aromatase plays a role in the development of bone tumor-induced hyperalgesia. Since spinal aromatase is also upregulated, but to a lesser extent, in non-painful melanoma bone tumors, it may also be neuroprotective and responsive to the changing tumor environment.

  18. Astrocytes Mediate In Vivo Cholinergic-Induced Synaptic Plasticity

    OpenAIRE

    2012-01-01

    In vivo and in vitro studies reveal that astrocytes, classically considered supportive cells for neurons, regulate synaptic plasticity in the mouse hippocampus and are directly involved in information storage.

  19. The effect of gallic acid on cytotoxicity, Ca(2+) homeostasis and ROS production in DBTRG-05MG human glioblastoma cells and CTX TNA2 rat astrocytes.

    Science.gov (United States)

    Hsu, Shu-Shong; Chou, Chiang-Ting; Liao, Wei-Chuan; Shieh, Pochuen; Kuo, Daih-Huang; Kuo, Chun-Chi; Jan, Chung-Ren; Liang, Wei-Zhe

    2016-05-25

    Gallic acid, a polyhydroxylphenolic compound, is widely distributed in various plants, fruits and foods. It has been shown that gallic acid passes into blood brain barrier and reaches the brain tissue of middle cerebral artery occlusion rats. However, the effect of gallic acid on Ca(2+) signaling in glia cells is unknown. This study explored whether gallic acid affected Ca(2+) homeostasis and induced Ca(2+)-associated cytotoxicity in DBTRG-05MG human glioblastoma cells and CTX TNA2 rat astrocytes. Gallic acid (20-40 μM) concentration-dependently induced cytotoxicity and intracellular Ca(2+) level ([Ca(2+)]i) increases in DBTRG-05MG cells but not in CTX TNA2 cells. In DBTRG-05MG cells, the Ca(2+) response was decreased by half by removal of extracellular Ca(2+). In Ca(2+)-containing medium, gallic acid-induced Ca(2+) entry was inhibited by store-operated Ca(2+) channel inhibitors (2-APB, econazole and SKF96365). In Ca(2+)-free medium, pretreatment with the endoplasmic reticulum Ca(2+) pump inhibitor thapsigargin abolished gallic acid-induced [Ca(2+)]i increases. Conversely, incubation with gallic acid also abolished thapsigargin-induced [Ca(2+)]i increases. Inhibition of phospholipase C with U73122 abolished gallic acid-induced [Ca(2+)]i increases. Gallic acid significantly caused cytotoxicity in DBTRG-05MG cells, which was partially prevented by prechelating cytosolic Ca(2+) with BAPTA-AM. Moreover, gallic acid activated mitochondrial apoptotic pathways that involved ROS production. Together, in DBTRG-05MG cells but not in CTX TNA2 cells, gallic acid induced [Ca(2+)]i increases by causing Ca(2+) entry via 2-APB, econazole and SKF96365-sensitive store-operated Ca(2+) entry, and phospholipase C-dependent release from the endoplasmic reticulum. This Ca(2+) signal subsequently evoked mitochondrial pathways of apoptosis that involved ROS production.

  20. Characterisation of the expression of NMDA receptors in human astrocytes.

    Directory of Open Access Journals (Sweden)

    Ming-Chak Lee

    Full Text Available Astrocytes have long been perceived only as structural and supporting cells within the central nervous system (CNS. However, the discovery that these glial cells may potentially express receptors capable of responding to endogenous neurotransmitters has resulted in the need to reassess astrocytic physiology. The aim of the current study was to characterise the expression of NMDA receptors (NMDARs in primary human astrocytes, and investigate their response to physiological and excitotoxic concentrations of the known endogenous NMDAR agonists, glutamate and quinolinic acid (QUIN. Primary cultures of human astrocytes were used to examine expression of these receptors at the mRNA level using RT-PCR and qPCR, and at the protein level using immunocytochemistry. The functionality role of the receptors was assessed using intracellular calcium influx experiments and measuring extracellular lactate dehydrogenase (LDH activity in primary cultures of human astrocytes treated with glutamate and QUIN. We found that all seven currently known NMDAR subunits (NR1, NR2A, NR2B, NR2C, NR2D, NR3A and NR3B are expressed in astrocytes, but at different levels. Calcium influx studies revealed that both glutamate and QUIN could activate astrocytic NMDARs, which stimulates Ca2+ influx into the cell and can result in dysfunction and death of astrocytes. Our data also show that the NMDAR ion channel blockers, MK801, and memantine can attenuate glutamate and QUIN mediated cell excitotoxicity. This suggests that the mechanism of glutamate and QUIN gliotoxicity is at least partially mediated by excessive stimulation of NMDARs. The present study is the first to provide definitive evidence for the existence of functional NMDAR expression in human primary astrocytes. This discovery has significant implications for redefining the cellular interaction between glia and neurons in both physiological processes and pathological conditions.

  1. Road for understanding cancer stem cells

    DEFF Research Database (Denmark)

    Serakinci, Nedime; Erzik, Can

    2007-01-01

    There is increasing evidence suggesting that stem cells are susceptive to carcinogenesis and, consequently, can be the origin of many cancers. Recently, the neoplastic potential of stem cells has been supported by many groups showing the existence of subpopulations with stem cell characteristics...... in tumor biopsies such as brain and breast. Evidence supporting the cancer stem cell hypothesis has gained impact due to progress in stem cell biology and development of new models to validate the self-renewal potential of stem cells. Recent evidence on the possible identification of cancer stem cells may...... offer an opportunity to use these cells as future therapeutic targets. Therefore, model systems in this field have become very important and useful. This review will focus on the state of knowledge on cancer stem cell research, including cell line models for cancer stem cells. The latter will, as models...

  2. Peptide gH625 enters into neuron and astrocyte cell lines and crosses the blood–brain barrier in rats

    Science.gov (United States)

    Valiante, Salvatore; Falanga, Annarita; Cigliano, Luisa; Iachetta, Giuseppina; Busiello, Rosa Anna; La Marca, Valeria; Galdiero, Massimiliano; Lombardi, Assunta; Galdiero, Stefania

    2015-01-01

    Peptide gH625, derived from glycoprotein H of herpes simplex virus type 1, can enter cells efficiently and deliver a cargo. Nanoparticles armed with gH625 are able to cross an in vitro model of the blood–brain barrier (BBB). In the present study, in vitro experiments were performed to investigate whether gH625 can enter and accumulate in neuron and astrocyte cell lines. The ability of gH625 to cross the BBB in vivo was also evaluated. gH625 was administered in vivo to rats and its presence in the liver and in the brain was detected. Within 3.5 hours of intravenous administration, gH625 can be found beyond the BBB in proximity to cell neurites. gH625 has no toxic effects in vivo, since it does not affect the maximal oxidative capacity of the brain or the mitochondrial respiration rate. Our data suggest that gH625, with its ability to cross the BBB, represents a novel nanocarrier system for drug delivery to the central nervous system. These results open up new possibilities for direct delivery of drugs into patients in the field of theranostics and might address the treatment of several human diseases. PMID:25792823

  3. Peptide gH625 enters into neuron and astrocyte cell lines and crosses the blood-brain barrier in rats.

    Science.gov (United States)

    Valiante, Salvatore; Falanga, Annarita; Cigliano, Luisa; Iachetta, Giuseppina; Busiello, Rosa Anna; La Marca, Valeria; Galdiero, Massimiliano; Lombardi, Assunta; Galdiero, Stefania

    2015-01-01

    Peptide gH625, derived from glycoprotein H of herpes simplex virus type 1, can enter cells efficiently and deliver a cargo. Nanoparticles armed with gH625 are able to cross an in vitro model of the blood-brain barrier (BBB). In the present study, in vitro experiments were performed to investigate whether gH625 can enter and accumulate in neuron and astrocyte cell lines. The ability of gH625 to cross the BBB in vivo was also evaluated. gH625 was administered in vivo to rats and its presence in the liver and in the brain was detected. Within 3.5 hours of intravenous administration, gH625 can be found beyond the BBB in proximity to cell neurites. gH625 has no toxic effects in vivo, since it does not affect the maximal oxidative capacity of the brain or the mitochondrial respiration rate. Our data suggest that gH625, with its ability to cross the BBB, represents a novel nanocarrier system for drug delivery to the central nervous system. These results open up new possibilities for direct delivery of drugs into patients in the field of theranostics and might address the treatment of several human diseases.

  4. Transplantation of specific human astrocytes promotes functional recovery after spinal cord injury.

    Directory of Open Access Journals (Sweden)

    Stephen J A Davies

    Full Text Available Repairing trauma to the central nervous system by replacement of glial support cells is an increasingly attractive therapeutic strategy. We have focused on the less-studied replacement of astrocytes, the major support cell in the central nervous system, by generating astrocytes from embryonic human glial precursor cells using two different astrocyte differentiation inducing factors. The resulting astrocytes differed in expression of multiple proteins thought to either promote or inhibit central nervous system homeostasis and regeneration. When transplanted into acute transection injuries of the adult rat spinal cord, astrocytes generated by exposing human glial precursor cells to bone morphogenetic protein promoted significant recovery of volitional foot placement, axonal growth and notably robust increases in neuronal survival in multiple spinal cord laminae. In marked contrast, human glial precursor cells and astrocytes generated from these cells by exposure to ciliary neurotrophic factor both failed to promote significant behavioral recovery or similarly robust neuronal survival and support of axon growth at sites of injury. Our studies thus demonstrate functional differences between human astrocyte populations and suggest that pre-differentiation of precursor cells into a specific astrocyte subtype is required to optimize astrocyte replacement therapies. To our knowledge, this study is the first to show functional differences in ability to promote repair of the injured adult central nervous system between two distinct subtypes of human astrocytes derived from a common fetal glial precursor population. These findings are consistent with our previous studies of transplanting specific subtypes of rodent glial precursor derived astrocytes into sites of spinal cord injury, and indicate a remarkable conservation from rat to human of functional differences between astrocyte subtypes. In addition, our studies provide a specific population of human

  5. Transplantation of specific human astrocytes promotes functional recovery after spinal cord injury.

    Science.gov (United States)

    Davies, Stephen J A; Shih, Chung-Hsuan; Noble, Mark; Mayer-Proschel, Margot; Davies, Jeannette E; Proschel, Christoph

    2011-03-02

    Repairing trauma to the central nervous system by replacement of glial support cells is an increasingly attractive therapeutic strategy. We have focused on the less-studied replacement of astrocytes, the major support cell in the central nervous system, by generating astrocytes from embryonic human glial precursor cells using two different astrocyte differentiation inducing factors. The resulting astrocytes differed in expression of multiple proteins thought to either promote or inhibit central nervous system homeostasis and regeneration. When transplanted into acute transection injuries of the adult rat spinal cord, astrocytes generated by exposing human glial precursor cells to bone morphogenetic protein promoted significant recovery of volitional foot placement, axonal growth and notably robust increases in neuronal survival in multiple spinal cord laminae. In marked contrast, human glial precursor cells and astrocytes generated from these cells by exposure to ciliary neurotrophic factor both failed to promote significant behavioral recovery or similarly robust neuronal survival and support of axon growth at sites of injury. Our studies thus demonstrate functional differences between human astrocyte populations and suggest that pre-differentiation of precursor cells into a specific astrocyte subtype is required to optimize astrocyte replacement therapies. To our knowledge, this study is the first to show functional differences in ability to promote repair of the injured adult central nervous system between two distinct subtypes of human astrocytes derived from a common fetal glial precursor population. These findings are consistent with our previous studies of transplanting specific subtypes of rodent glial precursor derived astrocytes into sites of spinal cord injury, and indicate a remarkable conservation from rat to human of functional differences between astrocyte subtypes. In addition, our studies provide a specific population of human astrocytes that

  6. Stem cell divisions, somatic mutations, cancer etiology, and cancer prevention.

    Science.gov (United States)

    Tomasetti, Cristian; Li, Lu; Vogelstein, Bert

    2017-03-24

    Cancers are caused by mutations that may be inherited, induced by environmental factors, or result from DNA replication errors (R). We studied the relationship between the number of normal stem cell divisions and the risk of 17 cancer types in 69 countries throughout the world. The data revealed a strong correlation (median = 0.80) between cancer incidence and normal stem cell divisions in all countries, regardless of their environment. The major role of R mutations in cancer etiology was supported by an independent approach, based solely on cancer genome sequencing and epidemiological data, which suggested that R mutations are responsible for two-thirds of the mutations in human cancers. All of these results are consistent with epidemiological estimates of the fraction of cancers that can be prevented by changes in the environment. Moreover, they accentuate the importance of early detection and intervention to reduce deaths from the many cancers arising from unavoidable R mutations.

  7. Nanomaterials in Targeting Cancer Stem Cells for Cancer Therapy

    Science.gov (United States)

    Qin, Weiwei; Huang, Guan; Chen, Zuanguang; Zhang, Yuanqing

    2017-01-01

    Cancer stem cells (CSCs) have been identified in almost all cancers and give rise to metastases and can also act as a reservoir of cancer cells that may cause a relapse after surgery, radiation, or chemotherapy. Thus they are obvious targets in therapeutic approaches and also a great challenge in cancer treatment. The threat presented by CSCs lies in their unlimited proliferative ability and multidrug resistance. These findings have necessitated an effective novel strategy to target CSCs for cancer treatment. Nanomaterials are on the route to providing novel methods in cancer therapies. Although, there have been a large number of excellent work in the field of targeted cancer therapy, it remains an open question how nanomaterials can meet future demands for targeting and eradicating of CSCs. In this review, we summarized recent and highlighted future prospects for targeting CSCs for cancer therapies by using a variety of nanomaterials.

  8. Transfer of mitochondria from astrocytes to neurons after stroke

    Science.gov (United States)

    Hayakawa, Kazuhide; Esposito, Elga; Wang, Xiaohua; Terasaki, Yasukazu; Liu, Yi; Xing, Changhong; Ji, Xunming; Lo, Eng H.

    2016-01-01

    Recently, it was suggested that neurons can release and transfer damaged mitochondria to astrocytes for disposal and recycling 1. This ability to exchange mitochondria may represent a potential mode of cell-cell signaling in the central nervous system (CNS). Here, we show that astrocytes can also release functional mitochondria that enter into neurons. Astrocytic release of extracellular mitochondria particles was mediated by a calcium-dependent mechanism involving CD38/cyclic ADP ribose signaling. Transient focal cerebral ischemia in mice induced astrocytic mitochondria entry to adjacent neurons that amplified cell survival signals. Suppression of CD38 signaling with siRNA reduced extracellular mitochondria transfer and worsened neurological outcomes. These findings suggest a new mitochondrial mechanism of neuroglial crosstalk that may contribute to endogenous neuroprotective and neurorecovery mechanisms after stroke. PMID:27466127

  9. Versatile and simple approach to determine astrocyte territories in mouse neocortex and hippocampus.

    Directory of Open Access Journals (Sweden)

    Antje Grosche

    Full Text Available BACKGROUND: Besides their neuronal support functions, astrocytes are active partners in neuronal information processing. The typical territorial structure of astrocytes (the volume of neuropil occupied by a single astrocyte is pivotal for many aspects of glia-neuron interactions. METHODS: Individual astrocyte territorial volumes are measured by Golgi impregnation, and astrocyte densities are determined by S100β immunolabeling. These data are compared with results from conventionally applied methods such as dye filling and determination of the density of astrocyte networks by biocytin loading. Finally, we implemented our new approach to investigate age-related changes in astrocyte territories in the cortex and hippocampus of 5- and 21-month-old mice. RESULTS: The data obtained by our simplified approach based on Golgi impregnation were compared to previously published dye filling experiments, and yielded remarkably comparable results regarding astrocyte territorial volumes. Moreover, we found that almost all coupled astrocytes (as indicated by biocytin loading were immunopositive for S100β. A first application of this new experimental approach gives insight in age-dependent changes in astrocyte territorial volumes. They increased with age, while cell densities remained stable. In 5-month-old mice, the overlap factor was close to 1, revealing little or no interdigitation of astrocyte territories. However, in 21-month-old mice, the overlap factor was more than 2, suggesting that processes of adjacent astrocytes interdigitate. CONCLUSION: Here we verified the usability of a simple, versatile method for assessing astrocyte territories and the overlap factor between adjacent territories. Second, we found that there is an age-related increase in territorial volumes of astrocytes that leads to loss of the strict organization in non-overlapping territories. Future studies should elucidate the physiological relevance of this adaptive reaction of

  10. Drugs Approved for Kidney (Renal Cell) Cancer

    Science.gov (United States)

    ... 2015 2014 2013 2012 Media Resources Media Contacts Multicultural Media ... This page lists cancer drugs approved by the Food and Drug Administration (FDA) for kidney (renal cell) cancer. The list ...

  11. Implications of Stem Cells and Cancer Stem Cells for Understanding Fomation and Therapy of Cancer

    Institute of Scientific and Technical Information of China (English)

    Guanghui Li; Donglin Wang

    2005-01-01

    Most cancers are heterogeneous with respect to proliferation and differentiation. There is increasing evidence suggesting that only a minority of cancer cells, tumorigenic or tumor initiating cells, possess the capacity to proliferate extensively and form new hematopoietic cancer or solid tumors. Tumor initiating cells share characteristics required for normal stem cells. The dysregulation of self-renewal and proliferation of stem cells is a likely requirement for cancer development. This review formulates a model for the origin of cancer stem cells and regulating self-renewal which influences the way we study and treat cancer.

  12. Enterovirus 71 VP1 activates calmodulin-dependent protein kinase II and results in the rearrangement of vimentin in human astrocyte cells.

    Directory of Open Access Journals (Sweden)

    Cong Haolong

    Full Text Available Enterovirus 71 (EV71 is one of the main causative agents of foot, hand and mouth disease. Its infection usually causes severe central nervous system diseases and complications in infected infants and young children. In the present study, we demonstrated that EV71 infection caused the rearrangement of vimentin in human astrocytoma cells. The rearranged vimentin, together with various EV71 components, formed aggresomes-like structures in the perinuclear region. Electron microscopy and viral RNA labeling indicated that the aggresomes were virus replication sites since most of the EV71 particles and the newly synthesized viral RNA were concentrated here. Further analysis revealed that the vimentin in the virus factories was serine-82 phosphorylated. More importantly, EV71 VP1 protein is responsible for the activation of calmodulin-dependent protein kinase II (CaMK-II which phosphorylated the N-terminal domain of vimentin on serine 82. Phosphorylation of vimentin and the formation of aggresomes were required for the replication of EV71 since the latter was decreased markedly after phosphorylation was blocked by KN93, a CaMK-II inhibitor. Thus, as one of the consequences of CaMK-II activation, vimentin phosphorylation and rearrangement may support virus replication by playing a structural role for the formation of the replication factories. Collectively, this study identified the replication centers of EV71 in human astrocyte cells. This may help us understand the replication mechanism and pathogenesis of EV71 in human.

  13. The Refsum disease marker phytanic acid, a branched chain fatty acid, affects Ca2+ homeostasis and mitochondria, and reduces cell viability in rat hippocampal astrocytes.

    Science.gov (United States)

    Kahlert, Stefan; Schönfeld, Peter; Reiser, Georg

    2005-02-01

    The saturated branched chain fatty acid, phytanic acid, a degradation product of chlorophyll, accumulates in Refsum disease, an inherited peroxisomal disorder with neurological clinical features. To elucidate the pathogenic mechanism, we investigated the influence of phytanic acid on cellular physiology of rat hippocampal astrocytes. Phytanic acid (100 microM) induced an immediate transient increase in cytosolic Ca2+ concentration, followed by a plateau. The peak of this biphasic Ca2+ response was largely independent of extracellular Ca2+, indicating activation of cellular Ca2+ stores by phytanic acid. Phytanic acid depolarized mitochondria without causing in situ swelling of mitochondria. The slow decrease of mitochondrial potential is not consistent with fast and simultaneous opening of the mitochondrial permeability transition pore. However, phytanic acid induced substantial generation of reactive oxygen species. Phytanic acid caused astroglia cell death after a few hours of exposure. We suggest that the cytotoxic effect of phytanic acid seems to be due to a combined action on Ca2+ regulation, mitochondrial depolarization, and increased ROS generation in brain cells.

  14. Colon Cancer Cell Separation by Dielectrophoresis

    Science.gov (United States)

    Yang, Fang; Yang, Xiaoming; Jiang, H.; Wood, P.; Hrushesky, W.; Wang, Guiren

    2009-11-01

    Separation of cancer cells from the other biological cells can be useful for clinical cancer diagnosis and cancer treatment. In this presentation, conventional dielectrophoresis (c-DEP) is used in a microfluidic chip to manipulate and collect colorectal cancer HCT116 cell, which is doped with Human Embryonic Kidney 293 cells (HEK 293). It is noticed that, the HCT116 cell are deflected to a side channel from a main channel clearly by apply electric field at particular AC frequency band. This motion caused by negative DEP can be used to separate the cancer cell from others. In this manuscript, chip design, flow condition, the DEP spectrum of the cancer cell are reported respectively, and the separation and collection efficiency are investigated as well. The sorter is microfabricated using plastic laminate technology. -/abstract- This work has been financially supported by the NSF RII funding (EP

  15. Imaging of mitochondrial Ca2+ dynamics in astrocytes using cell-specific mitochondria-targeted GCaMP5G/6s: mitochondrial Ca2+ uptake and cytosolic Ca2+ availability via the endoplasmic reticulum store.

    Science.gov (United States)

    Li, Hailong; Wang, Xiaowan; Zhang, Nannan; Gottipati, Manoj K; Parpura, Vladimir; Ding, Shinghua

    2014-12-01

    Mitochondrial Ca(2+) plays a critical physiological role in cellular energy metabolism and signaling, and its overload contributes to various pathological conditions including neuronal apoptotic death in neurological diseases. Live cell mitochondrial Ca(2+) imaging is an important approach to understand mitochondrial Ca(2+) dynamics. Recently developed GCaMP genetically-encoded Ca(2+) indicators provide unique opportunity for high sensitivity/resolution and cell type-specific mitochondrial Ca(2+) imaging. In the current study, we implemented cell-specific mitochondrial targeting of GCaMP5G/6s (mito-GCaMP5G/6s) and used two-photon microscopy to image astrocytic and neuronal mitochondrial Ca(2+) dynamics in culture, revealing Ca(2+) uptake mechanism by these organelles in response to cell stimulation. Using these mitochondrial Ca(2+) indicators, our results show that mitochondrial Ca(2+) uptake in individual mitochondria in cultured astrocytes and neurons can be seen after stimulations by ATP and glutamate, respectively. We further studied the dependence of mitochondrial Ca(2+) dynamics on cytosolic Ca(2+) changes following ATP stimulation in cultured astrocytes by simultaneously imaging mitochondrial and cytosolic Ca(2+) increase using mito-GCaMP5G and a synthetic organic Ca(2+) indicator, x-Rhod-1, respectively. Combined with molecular intervention in Ca(2+) signaling pathway, our results demonstrated that the mitochondrial Ca(2+) uptake is tightly coupled with inositol 1,4,5-trisphosphate receptor-mediated Ca(2+) release from the endoplasmic reticulum and the activation of G protein-coupled receptors. The current study provides a novel approach to image mitochondrial Ca(2+) dynamics as well as Ca(2+) interplay between the endoplasmic reticulum and mitochondria, which is relevant for neuronal and astrocytic functions in health and disease.

  16. Significance of Cancer Stem Cells in Anti-Cancer Therapies

    Science.gov (United States)

    Botelho, Mónica; Alves, Helena

    2017-01-01

    Stem cells are the focus of cutting edge research interest because of their competence both to self-renew and proliferate, and to differentiate into a variety of tissues, offering enticing prospects of growing replacement organs in vitro, among other possible therapeutic implications. It is conceivable that cancer stem cells share a number of biological hallmarks that are different from their normal-tissue counterparts and that these might be taken advantage of for therapeutic benefits. In this review we discuss the significance of cancer stem cells in diagnosis and prognosis of cancer as well as in the development of new strategies for anti-cancer drug design.

  17. Purification and Characterization of Progenitor and Mature Human Astrocytes Reveals Transcriptional and Functional Differences with Mouse.

    Science.gov (United States)

    Zhang, Ye; Sloan, Steven A; Clarke, Laura E; Caneda, Christine; Plaza, Colton A; Blumenthal, Paul D; Vogel, Hannes; Steinberg, Gary K; Edwards, Michael S B; Li, Gordon; Duncan, John A; Cheshier, Samuel H; Shuer, Lawrence M; Chang, Edward F; Grant, Gerald A; Gephart, Melanie G Hayden; Barres, Ben A

    2016-01-01

    The functional and molecular similarities and distinctions between human and murine astrocytes are poorly understood. Here, we report the development of an immunopanning method to acutely purify astrocytes from fetal, juvenile, and adult human brains and to maintain these cells in serum-free cultures. We found that human astrocytes have abilities similar to those of murine astrocytes in promoting neuronal survival, inducing functional synapse formation, and engulfing synaptosomes. In contrast to existing observations in mice, we found that mature human astrocytes respond robustly to glutamate. Next, we performed RNA sequencing of healthy human astrocytes along with astrocytes from epileptic and tumor foci and compared these to human neurons, oligodendrocytes, microglia, and endothelial cells (available at http://www.brainrnaseq.org). With these profiles, we identified novel human-specific astrocyte genes and discovered a transcriptome-wide transformation between astrocyte precursor cells and mature post-mitotic astrocytes. These data represent some of the first cell-type-specific molecular profiles of the healthy and diseased human brain.

  18. Targetless T cells in cancer immunotherapy

    DEFF Research Database (Denmark)

    thor Straten, Eivind Per; Garrido, Federico

    2016-01-01

    Attention has recently focused on new cancer immunotherapy protocols aiming to activate T cell mediated anti-tumor responses. To this end, administration of antibodies that target inhibitory molecules regulating T-cell cytotoxicity has achieved impressive clinical responses, as has adoptive cell...... infiltrate tumor tissues and destroy HLA class I positive tumor cells expressing the specific antigen. In fact, current progress in the field of cancer immune therapy is based on the capacity of T cells to kill cancer cells that present tumor antigen in the context on an HLA class I molecule. However......, it is also well established that cancer cells are often characterized by loss or down regulation of HLA class I molecules, documented in a variety of human tumors. Consequently, immune therapy building on CD8 T cells will be futile in patients harboring HLA class-I negative or deficient cancer cells...

  19. Pancreatic cancer stem cells: fact or fiction?

    Science.gov (United States)

    Bhagwandin, Vikash J; Shay, Jerry W

    2009-04-01

    The terms cancer-initiating or cancer stem cells have been the subject of great interest in recent years. In this review we will use pancreatic cancer as an overall theme to draw parallels with historical findings to compare to recent reports of stem-like characteristics in pancreatic cancer. We will cover such topics as label-retaining cells (side-population), ABC transporter pumps, telomerase, quiescence, cell surface stem cell markers, and epithelial-mesenchymal transitions. Finally we will integrate the available findings into a pancreatic stem cell model that also includes metastatic disease.

  20. Effects of huperzine A on secretion of nerve growth factor in cultured rat cortical astrocytes and neurite outgrowth in rat PC12 cells

    Institute of Scientific and Technical Information of China (English)

    Li-li TANG; Rui WANG; Xi-can TANG

    2005-01-01

    Aim: To study the effects of huperzine A (HupA) on neuritogenic activity and the expression of nerve growth factor (NGF). Methods: After being treated with 10 μmol/L HupA, neurite outgrowth of PC12 cells was observed and counted under phase-contrast microscopy. Mitogenic activity was assayed by [3H]thymidine incorporation. Cell cytotoxicity was evaluated by lactate dehydrogenase (LDH)release. AChE activity, mRNA and protein expression were measured by the Ellman's method, RT-PCR, and Western blot, respectively. NGF mRNA and protein levels were determined by RT-PCR and ELISA assays. Results: Treatment of PC 12 cells with 10 μmol/L HupA for 48 h markedly increased the number of neuritebearing cells, but caused no significant alteration in cell viability or other signs of cytotoxicity. In addition to inhibiting AChE activity, 10 μmol/L HupA also increased the mRNA and protein levels of this enzyme. In addition, following 2 h exposure of the astrocytes to 10 μmol/L HupA, there was a significant up-regulation of mRNA for NGF and P75 low-affinity NGF receptor. The protein level of NGF was also increased after 24 h treatment with HupA. Conclusion: Our findings demonstrate for the first time that HupA has a direct or indirect neurotrophic activity, which might be beneficial in treatment of neurodegenerative disorders such as Alzheimer disease.

  1. Small ubiquitin-like modifier 1-3 conjugation [corrected] is activated in human astrocytic brain tumors and is required for glioblastoma cell survival.

    Science.gov (United States)

    Yang, Wei; Wang, Liangli; Roehn, Gabriele; Pearlstein, Robert D; Ali-Osman, Francis; Pan, Hongjie; Goldbrunner, Roland; Krantz, Matthew; Harms, Christoph; Paschen, Wulf

    2013-01-01

    Small ubiquitin-like modifier (SUMO1-3) constitutes a group of proteins that conjugate to lysine residues of target proteins thereby modifying their activity, stability, and subcellular localization. A large number of SUMO target proteins are transcription factors and other nuclear proteins involved in gene expression. Furthermore, SUMO conjugation plays key roles in genome stability, quality control of newly synthesized proteins, proteasomal degradation of proteins, and DNA damage repair. Any marked increase in levels of SUMO-conjugated proteins is therefore expected to have a major impact on the fate of cells. We show here that SUMO conjugation is activated in human astrocytic brain tumors. Levels of both SUMO1- and SUMO2/3-conjugated proteins were markedly increased in tumor samples. The effect was least pronounced in low-grade astrocytoma (WHO Grade II) and most pronounced in glioblastoma multiforme (WHO Grade IV). We also found a marked rise in levels of Ubc9, the only SUMO conjugation enzyme identified so far. Blocking SUMO1-3 conjugation in glioblastoma cells by silencing their expression blocked DNA synthesis, cell growth, and clonogenic survival of cells. It also resulted in DNA-dependent protein kinase-induced phosphorylation of H2AX, indicative of DNA double-strand damage, and G(2) /M cell cycle arrest. Collectively, these findings highlight the pivotal role of SUMO conjugation in DNA damage repair processes and imply that the SUMO conjugation pathway could be a new target of therapeutic intervention aimed at increasing the sensitivity of glioblastomas to radiotherapy and chemotherapy.

  2. Lentivirus-Mediated Knockdown of Astrocyte Elevated Gene-1 Inhibits Growth and Induces Apoptosis through MAPK Pathways in Human Retinoblastoma Cells.

    Directory of Open Access Journals (Sweden)

    Ying Chang

    Full Text Available To explore expression and function of astrocyte elevated gene-1 (AEG-1 in human retinoblastoma (RB.The expression of AEG-1 in histological sections of human RBs and in RB cell lines was examined using immunohistochemical staining and RT-PCR and Western blotting respectively. We knocked down AEG-1 gene levels by AEG-1-siRNA lentivirus transfection of human RB cell lines SO-RB50 and Y79, and using an MTT assay, we assessed the role of AEG-1 on RB cell proliferation. The biological significance of lentivirus transfection induced AEG-1 down-regulation was examined by assessing the apoptosis rate in the transfected RB cells by Annexin V-APC staining and flow cytometry. We additionally measured the expression of Bcl-2, Bax, cleaved-caspase-3 and caspase-3, and the phosphorylation and non-phosphorylation alternation of MAPKs.AEG-1 expression was detected to be strongly positive in the histological slides of 35 out of 54 (65% patients with RB. AEG-1 expression increased significantly (P<0.05 with tumor stage. In the RB cell lines SO-RB50, Y79 and WERI-RB1 as compared with retinal pigment epithelium cells, expression of AEG-1 mRNA and AEG-1 protein was significantly higher. In AEG-1-siRNA lentivirus transfected cell cultures as compared with negative control lentivirus transfected cell cultures, levels of AEG-1 mRNA and of AEG-1 protein (P<0.05 and cell growth rates (P<0.01 were significantly lower, and apoptosis rate (P<0.001, Bax/Bcl-2 ratio and cleaved-caspase-3 protein level were significantly increased. The P-ERK/ERK ratio was significantly decreased in the AEG-1-siRNA lentivirus transfected cell lines.Expression of AEG-1 was associated with RB, in histological slides of patients and in cell culture experiments. Lentivirus transfection induced knockdown of AEG-1 had a tumor suppressive effect, potentially by tumor cell apoptosis induction through inhibition of ERK.

  3. YAP stabilizes SMAD1 and promotes BMP2-induced neocortical astrocytic differentiation.

    Science.gov (United States)

    Huang, Zhihui; Hu, Jinxia; Pan, Jinxiu; Wang, Ying; Hu, Guoqing; Zhou, Jiliang; Mei, Lin; Xiong, Wen-Cheng

    2016-07-01

    ‪YAP (yes-associated protein), a key transcriptional co-factor that is negatively regulated by the Hippo pathway, is crucial for the development and size control of multiple organs, including the liver. However, its role in the brain remains unclear. Here, we provide evidence for YAP regulation of mouse neocortical astrocytic differentiation and proliferation. YAP was undetectable in neurons, but selectively expressed in neural stem cells (NSCs) and astrocytes. YAP in NSCs was required for neocortical astrocytic differentiation, with no apparent role in self-renewal or neural differentiation. However, YAP in astrocytes was necessary for astrocytic proliferation. Yap (Yap1) knockout, Yap(nestin) conditional knockout and Yap(GFAP) conditional knockout mice displayed fewer neocortical astrocytes and impaired astrocytic proliferation and, consequently, death of neocortical neurons. Mechanistically, YAP was activated by BMP2, and the active/nuclear YAP was crucial for BMP2 induction and stabilization of SMAD1 and astrocytic differentiation. Expression of SMAD1 in YAP-deficient NSCs partially rescued the astrocytic differentiation deficit in response to BMP2. Taken together, these results identify a novel function of YAP in neocortical astrocytic differentiation and proliferation, and reveal a BMP2-YAP-SMAD1 pathway underlying astrocytic differentiation in the developing mouse neocortex.

  4. Lrp4 in astrocytes modulates glutamatergic transmission.

    Science.gov (United States)

    Sun, Xiang-Dong; Li, Lei; Liu, Fang; Huang, Zhi-Hui; Bean, Jonathan C; Jiao, Hui-Feng; Barik, Arnab; Kim, Seon-Myung; Wu, Haitao; Shen, Chengyong; Tian, Yun; Lin, Thiri W; Bates, Ryan; Sathyamurthy, Anupama; Chen, Yong-Jun; Yin, Dong-Min; Xiong, Lei; Lin, Hui-Ping; Hu, Jin-Xia; Li, Bao-Ming; Gao, Tian-Ming; Xiong, Wen-Cheng; Mei, Lin

    2016-08-01

    Neurotransmission requires precise control of neurotransmitter release from axon terminals. This process is regulated by glial cells; however, the underlying mechanisms are not fully understood. We found that glutamate release in the brain was impaired in mice lacking low-density lipoprotein receptor-related protein 4 (Lrp4), a protein that is critical for neuromuscular junction formation. Electrophysiological studies revealed compromised release probability in astrocyte-specific Lrp4 knockout mice. Lrp4 mutant astrocytes suppressed glutamatergic transmission by enhancing the release of ATP, whose level was elevated in the hippocampus of Lrp4 mutant mice. Consequently, the mutant mice were impaired in locomotor activity and spatial memory and were resistant to seizure induction. These impairments could be ameliorated by blocking the adenosine A1 receptor. The results reveal a critical role for Lrp4, in response to agrin, in modulating astrocytic ATP release and synaptic transmission. Our findings provide insight into the interaction between neurons and astrocytes for synaptic homeostasis and/or plasticity.

  5. The biology of cancer stem cells.

    Science.gov (United States)

    Lobo, Neethan A; Shimono, Yohei; Qian, Dalong; Clarke, Michael F

    2007-01-01

    Cancers originally develop from normal cells that gain the ability to proliferate aberrantly and eventually turn malignant. These cancerous cells then grow clonally into tumors and eventually have the potential to metastasize. A central question in cancer biology is, which cells can be transformed to form tumors? Recent studies elucidated the presence of cancer stem cells that have the exclusive ability to regenerate tumors. These cancer stem cells share many characteristics with normal stem cells, including self-renewal and differentiation. With the growing evidence that cancer stem cells exist in a wide array of tumors, it is becoming increasingly important to understand the molecular mechanisms that regulate self-renewal and differentiation because corruption of genes involved in these pathways likely participates in tumor growth. This new paradigm of oncogenesis has been validated in a growing list of tumors. Studies of normal and cancer stem cells from the same tissue have shed light on the ontogeny of tumors. That signaling pathways such as Bmi1 and Wnt have similar effects in normal and cancer stem cell self-renewal suggests that common molecular pathways regulate both populations. Understanding the biology of cancer stem cells will contribute to the identification of molecular targets important for future therapies.

  6. Characterizing cancer cells with cancer stem cell-like features in 293T human embryonic kidney cells

    OpenAIRE

    Buchholz Thomas A; Lacerda Lara; Xu Wei; Robertson Fredika; Ueno Naoto T; Lucci Anthony; Landis Melissa D; Rodriguez Angel A; Li Li; Cohen Evan; Gao Hui; Krishnamurthy Savitri; Zhang Xiaomei; Debeb Bisrat G; Cristofanilli Massimo

    2010-01-01

    Abstract Background Since the first suggestion of prospectively identifiable cancer stem cells in solid tumors, efforts have been made to characterize reported cancer stem cell surrogates in existing cancer cell lines, and cell lines rich with these surrogates have been used to screen for cancer stem cell targeted agents. Although 293T cells were derived from human embryonic kidney, transplantation of these cells into the mammary fat pad yields aggressive tumors that self-renew as evidenced b...

  7. HIV-1-infected and immune-activated macrophages induce astrocytic differentiation of human cortical neural progenitor cells via the STAT3 pathway.

    Directory of Open Access Journals (Sweden)

    Hui Peng

    Full Text Available Diminished adult neurogenesis is considered a potential mechanism in the pathogenesis of HIV-1-associated dementia (HAD. In HAD, HIV-1-infected and immune-activated brain mononuclear phagocytes (MP; perivascular macrophages and microglia drive central nervous system (CNS inflammation and may alter normal neurogenesis. We previously demonstrated HIV-1-infected and lipopolysaccharide (LPS activated monocyte-derived macrophages (MDM inhibit human neural progenitor cell (NPC neurogenesis, while enhancing astrogliogenesis through the secretion of the inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α, in vitro and in vivo. Here we further test the hypothesis that HIV-1-infected/activated MDM promote NPC astrogliogenesis via activation of the transcription factor signal transducer and activator of transcription 3 (STAT3, a critical factor for astrogliogenesis. Our results show that LPS-activated MDM-conditioned medium (LPS-MCM and HIV-infected/LPS-activated MDM-conditioned medium (LPS+HIV-MCM induced Janus kinase 1 (Jak1 and STAT3 activation. Induction of the Jak-STAT3 activation correlated with increased glia fibrillary acidic protein (GFAP expression, demonstrating an induction of astrogliogenesis. Moreover, STAT3-targeting siRNA (siSTAT3 decreased MCM-induced STAT3 activation and NPC astrogliogenesis. Furthermore, inflammatory cytokines (including IL-6, IL-1β and TNF-α produced by LPS-activated and/or HIV-1-infected MDM may contribute to MCM-induced STAT3 activation and astrocytic differentiation. These observations were confirmed in severe combined immunodeficient (SCID mice with HIV-1 encephalitis (HIVE. In HIVE mice, siRNA control (without target sequence, sicon pre-transfected NPCs injected with HIV-1-infected MDM showed more astrocytic differentiation and less neuronal differentiation of NPCs as compared to NPC injection alone. siSTAT3 abrogated HIV-1-infected MDM-induced astrogliogenesis of injected NPCs. Collectively, these

  8. The Implications of Cancer Stem Cells for Cancer Therapy

    Directory of Open Access Journals (Sweden)

    Wenjing Jiang

    2012-12-01

    Full Text Available Surgery, radiotherapy and chemotherapy are universally recognized as the most effective anti-cancer therapies. Despite significant advances directed towards elucidating molecular mechanisms and developing clinical trials, cancer still remains a major public health issue. Recent studies have showed that cancer stem cells (CSCs, a small subpopulation of tumor cells, can generate bulk populations of nontumorigenic cancer cell progeny through the self-renewal and differentiation processes. As CSCs are proposed to persist in tumors as a distinct population and cause relapse and metastasis by giving rise to new tumors, development of CSC-targeted therapeutic strategies holds new hope for improving survival and quality of life in patients with cancer. Therapeutic innovations will emerge from a better understanding of the biology and environment of CSCs, which, however, are largely unexplored. This review summarizes the characteristics, evidences and development of CSCs, as well as implications and challenges for cancer treatment.

  9. Mild brain ischemia induces unique physiological properties in striatal astrocytes.

    Science.gov (United States)

    Wang, Li-Ping; Cheung, Giselle; Kronenberg, Golo; Gertz, Karen; Ji, Shengbo; Kempermann, Gerd; Endres, Matthias; Kettenmann, Helmut

    2008-07-01

    We studied the properties of GFAP-expressing cells in adult mouse striatum using acute brain slices from transgenic animals expressing EGFP under GFAP promoter. Under physiological conditions, two distinct populations of GFAP-EGFP cells could be identified: (1) brightly fluorescent cells had bushy processes, passive membrane properties, glutamate transporter activity, and high gap junction coupling rate typical for classical astrocytes; (2) weakly fluorescent cells were characterized by thin, clearly distinguishable processes, voltage-gated currents, complex responses to kainate, and low coupling rate reminiscent of an astrocyte subtype recently described in the hippocampus. Mild focal cerebral ischemia confers delayed neuronal cell death and astrogliosis in the striatum. Following middle cerebral artery occlusion and reperfusion, brightly fluorescent cells were the dominant GFAP-EGFP population observed within the ischemic lesion. Interestingly, the majority of these cells expressed voltage-gated channels, showed complex responses to kainate, and a high coupling rate exceeding that of brightly fluorescent control cells. A minority of cells had passive membrane properties and was coupled less compared with passive control cells. We conclude that, in the adult striatum, astrocytes undergo distinct pathophysiological changes after ischemic insults. The dominant population in the ischemic lesion constitutes a novel physiological phenotype unlike any normal astrocyte and generates a large syncytium which might be a neuroprotective response of reactive astrocytes.

  10. Breast cancer stem-like cells and breast cancer therapy

    Institute of Scientific and Technical Information of China (English)

    Niansong Qian; Nobuko Kawaguchi-Sakita; Masakazu Toi

    2010-01-01

    @@ Until the early 1990s, human cancers were considered a morphologically heterogeneous population of cells. In 1997, Bonnet et al[1] demonstrated that a small population of leukemia cells was able to differentiate in vivo into leukemic blasts, indicating that the leukemic clone was organized as a hierarchy; this was subsequently denoted as cancer stem like cells (CSCs). CSCs are cancer cells that possess characteristics associated with normal stem cells and have the specific ability to give rise to all cell types found in a particular cancer. One reason for the failure of traditional anti tumor therapies might be their inability to eradicate CSCs. Therefore, therapies must identify and destroy CSCs in both primary and metastatic tumors.

  11. Adipocyte activation of cancer stem cell signaling in breast cancer

    Institute of Scientific and Technical Information of China (English)

    Benjamin; Wolfson; Gabriel; Eades; Qun; Zhou

    2015-01-01

    Signaling within the tumor microenvironment has a critical role in cancer initiation and progression. Adipocytes, one of the major components of the breast microenvironment,have been shown to provide pro-tumorigenic signals that promote cancer cell proliferation and invasiveness in vitro and tumorigenicity in vivo. Adipocyte secreted factors such as leptin and interleukin-6(IL-6) have a paracrine effect on breast cancer cells. In adipocyte-adjacent breast cancer cells, the leptin and IL-6 signaling pathways activate janus kinase 2/signal transducer and activatorof transcription 5, promoting the epithelial-mesenchymal transition, and upregulating stemness regulators such as Notch, Wnt and the Sex determining region Y-box 2/octamer binding transcription factor 4/Nanog signaling axis. In this review we will summarize the major signaling pathways that regulate cancer stem cells in breast cancer and describe the effects that adipocyte secreted IL-6 and leptin have on breast cancer stem cell signaling. Finally we will introduce a new potential treatment paradigm of inhibiting the adipocyte-breast cancer cell signaling via targeting the IL-6 or leptin pathways.

  12. Targeting Strategies for Renal Cell Carcinoma: From Renal Cancer Cells to Renal Cancer Stem Cells

    OpenAIRE

    Zhi-xiang Yuan; Jingxin Mo; Guixian Zhao; Gang Shu; Hua-lin Fu; Wei Zhao

    2016-01-01

    Renal cell carcinoma (RCC) is a common form of urologic tumor that originates from the highly heterogeneous epithelium of renal tubules. Over the last decade, targeting therapies to renal cancer cells have transformed clinical care for RCC. Recently, it was proposed that renal cancer stem cells (CSCs) isolated from renal carcinomas were responsible for driving tumor growth and resistance to conventional chemotherapy and radiotherapy, according to the theory of CSCs; this has provided the rati...

  13. Dynamic volume changes in astrocytes are an intrinsic phenomenon mediated by bicarbonate ion flux.

    Directory of Open Access Journals (Sweden)

    Clare M Florence

    Full Text Available Astrocytes, the major type of non-neuronal cells in the brain, play an important functional role in extracellular potassium ([K(+](o and pH homeostasis. Pathological brain states that result in [K(+](o and pH dysregulation have been shown to cause astrocyte swelling. However, whether astrocyte volume changes occur under physiological conditions is not known. In this study we used two-photon imaging to visualize real-time astrocyte volume changes in the stratum radiatum of the hippocampus CA1 region. Astrocytes were observed to swell by 19.0±0.9% in response to a small physiological increase in the concentration of [K(+](o (3 mM. Astrocyte swelling was mediated by the influx of bicarbonate (HCO(3- ions as swelling was significantly decreased when the influx of HCO(3- was reduced. We found: 1 in HCO(3- free extracellular solution astrocytes swelled by 5.4±0.7%, 2 when the activity of the sodium-bicarbonate cotransporter (NBC was blocked the astrocytes swelled by 8.3±0.7%, and 3 in the presence of an extracellular carbonic anhydrase (CA inhibitor astrocytes swelled by 11.4±0.6%. Because a significant HCO(3- efflux is known to occur through the γ-amino-butyric acid (GABA channel, we performed a series of experiments to determine if astrocytes were capable of HCO(3- mediated volume shrinkage with GABA channel activation. Astrocytes were found to shrink -7.7±0.5% of control in response to the GABA(A channel agonist muscimol. Astrocyte shrinkage from GABA(A channel activation was significantly decreased to -5.0±0.6% of control in the presence of the membrane-permeant CA inhibitor acetazolamide (ACTZ. These dynamic astrocyte volume changes may represent a previously unappreciated yet fundamental mechanism by which astrocytes regulate physiological brain functioning.

  14. Breathless cancer cells get fat on glutamine

    Institute of Scientific and Technical Information of China (English)

    Dimitrios Anastasiou; Lewis C Cantley

    2012-01-01

    Many cancer cells depend on glutamine as a fuel for proliferation,yet the mechanisms by which glutamine supports cancer metabolism are not fully understood.Two recent studies highlight an important role for glutamine in the synthesis of lipids and provide novel insights into how glutamine metabolism could be targeted for cancer therapy.

  15. Radiofrequency treatment alters cancer cell phenotype

    Science.gov (United States)

    Ware, Matthew J.; Tinger, Sophia; Colbert, Kevin L.; Corr, Stuart J.; Rees, Paul; Koshkina, Nadezhda; Curley, Steven; Summers, H. D.; Godin, Biana

    2015-07-01

    The importance of evaluating physical cues in cancer research is gradually being realized. Assessment of cancer cell physical appearance, or phenotype, may provide information on changes in cellular behavior, including migratory or communicative changes. These characteristics are intrinsically different between malignant and non-malignant cells and change in response to therapy or in the progression of the disease. Here, we report that pancreatic cancer cell phenotype was altered in response to a physical method for cancer therapy, a non-invasive radiofrequency (RF) treatment, which is currently being developed for human trials. We provide a battery of tests to explore these phenotype characteristics. Our data show that cell topography, morphology, motility, adhesion and division change as a result of the treatment. These may have consequences for tissue architecture, for diffusion of anti-cancer therapeutics and cancer cell susceptibility within the tumor. Clear phenotypical differences were observed between cancerous and normal cells in both their untreated states and in their response to RF therapy. We also report, for the first time, a transfer of microsized particles through tunneling nanotubes, which were produced by cancer cells in response to RF therapy. Additionally, we provide evidence that various sub-populations of cancer cells heterogeneously respond to RF treatment.

  16. Astrocytes, Synapses and Brain Function: A Computational Approach

    Science.gov (United States)

    Nadkarni, Suhita

    2006-03-01

    Modulation of synaptic reliability is one of the leading mechanisms involved in long- term potentiation (LTP) and long-term depression (LTD) and therefore has implications in information processing in the brain. A recently discovered mechanism for modulating synaptic reliability critically involves recruitments of astrocytes - star- shaped cells that outnumber the neurons in most parts of the central nervous system. Astrocytes until recently were thought to be subordinate cells merely participating in supporting neuronal functions. New evidence, however, made available by advances in imaging technology has changed the way we envision the role of these cells in synaptic transmission and as modulator of neuronal excitability. We put forward a novel mathematical framework based on the biophysics of the bidirectional neuron-astrocyte interactions that quantitatively accounts for two distinct experimental manifestation of recruitment of astrocytes in synaptic transmission: a) transformation of a low fidelity synapse transforms into a high fidelity synapse and b) enhanced postsynaptic spontaneous currents when astrocytes are activated. Such a framework is not only useful for modeling neuronal dynamics in a realistic environment but also provides a conceptual basis for interpreting experiments. Based on this modeling framework, we explore the role of astrocytes for neuronal network behavior such as synchrony and correlations and compare with experimental data from cultured networks.

  17. Unperturbed posttranscriptional regulatory Rev protein function and HIV-1 replication in astrocytes.

    Directory of Open Access Journals (Sweden)

    Ashok Chauhan

    Full Text Available Astrocytes protect neurons, but also evoke proinflammatory responses to injury and viral infections, including HIV. There is a prevailing notion that HIV-1 Rev protein function in astrocytes is perturbed, leading to restricted viral replication. In earlier studies, our finding of restricted viral entry into astrocytes led us to investigate whether there are any intracellular restrictions, including crippled Rev function, in astrocytes. Despite barely detectable levels of DDX3 (Rev-supporting RNA helicase and TRBP (anti-PKR in primary astrocytes compared to astrocytic cells, Rev function was unperturbed in wild-type, but not DDX3-ablated astrocytes. As in permissive cells, after HIV-1 entry bypass in astrocytes, viral-encoded Tat and Rev proteins had robust regulatory activities, leading to efficient viral replication. Productive HIV-1 infection in astrocytes persisted for several weeks. Our findings on HIV-1 entry bypass in astrocytes demonstrated that the intracellular environment is conducive to viral replication and that Tat and Rev functions are unperturbed.

  18. Physiopathologic dynamics of vesicle traffic in astrocytes.

    Science.gov (United States)

    Potokar, Maja; Stenovec, Matjaž; Kreft, Marko; Gabrijel, Mateja; Zorec, Robert

    2011-02-01

    The view of how astrocytes, a type of glial cells, contribute to the functioning of the central nervous system (CNS) has changed greatly in the last decade. Although glial cells outnumber neurons in the mammalian brain, it was considered for over a century that they played a subservient role to neurons. This view changed. Functions thought to be exclusively present in neurons, i.e. excitability mediated release of chemical messengers, has also been demonstrated in astrocytes. In this process, following an increase in cytosolic calcium activity, membrane bound vesicles, storing chemical messengers (gliotransmitters), fuse with the plasma membrane, a process known as exocytosis, permitting the exit of vesicle cargo into the extracellular space. Vesicles are delivered to and are removed from the site of exocytosis by an amazingly complex set of processes that we have only started to learn about recently. In this paper we review vesicle traffic, which is subject to physiological regulation and may be changed under pathological conditions.

  19. Multiple oxygen tension environments reveal diverse patterns of transcriptional regulation in primary astrocytes.

    Directory of Open Access Journals (Sweden)

    Wayne Chadwick

    Full Text Available The central nervous system normally functions at O(2 levels which would be regarded as hypoxic by most other tissues. However, most in vitro studies of neurons and astrocytes are conducted under hyperoxic conditions without consideration of O(2-dependent cellular adaptation. We analyzed the reactivity of astrocytes to 1, 4 and 9% O(2 tensions compared to the cell culture standard of 20% O(2, to investigate their ability to sense and translate this O(2 information to transcriptional activity. Variance of ambient O(2 tension for rat astrocytes resulted in profound changes in ribosomal activity, cytoskeletal and energy-regulatory mechanisms and cytokine-related signaling. Clustering of transcriptional regulation patterns revealed four distinct response pattern groups that directionally pivoted around the 4% O(2 tension, or demonstrated coherent ascending/decreasing gene expression patterns in response to diverse oxygen tensions. Immune response and cell cycle/cancer-related signaling pathway transcriptomic subsets were significantly activated with increasing hypoxia, whilst hemostatic and cardiovascular signaling mechanisms were attenuated with increasing hypoxia. Our data indicate that variant O(2 tensions induce specific and physiologically-focused transcript regulation patterns that may underpin important physiological mechanisms that connect higher neurological activity to astrocytic function and ambient oxygen environments. These strongly defined patterns demonstrate a strong bias for physiological transcript programs to pivot around the 4% O(2 tension, while uni-modal programs that do not, appear more related to pathological actions. The functional interaction of these transcriptional 'programs' may serve to regulate the dynamic vascular responsivity of the central nervous system during periods of stress or heightened activity.

  20. Resveratrol induces apoptosis in pancreatic cancer cells

    Institute of Scientific and Technical Information of China (English)

    ZHOU Jia-hua; CHENG Hai-yan; YU Ze-qian; HE Dao-wei; PAN Zheng; YANG De-tong

    2011-01-01

    Background Pancreatic cancer is one of the most lethal human cancers with a very low survival rate of 5 years.Conventional cancer treatments including surgery, radiation, chemotherapy or combinations of these show little effect on this disease. Several proteins have been proved critical to the development and the progression of pancreatic cancer.The aim of this study was to investigate the effect of resveratrol on apoptosis in pancreatic cancer cells.Methods Several pancreatic cancer cell lines were screened by resveratrol, and its toxicity was tested by normal pancreatic cells. Western blotting was then performed to analyze the molecular mechanism of resveratrol induced apoptosis of pancreatic cancer cell lines.Results In the screened pancreatic cancer cell lines, capan-2 and colo357 showed high sensitivity to resveratrol induced apoptosis. Resveratrol exhibited insignificant toxicity to normal pancreatic cells. In resveratrol sensitive cells,capan-2 and colo357, the activation of caspase-3 was detected and showed significant caspase-3 activation upon resveratrol treatment; p53 and p21 were also detected up-regulated upon resveratrol treatment.Conclusion Resveratrol provides a promising anti-tumor stratagy to fight against pancreatic cancer.

  1. Stem cell characteristics in prostate cancer cell lines.

    NARCIS (Netherlands)

    Pfeiffer, M.J.; Schalken, J.A.

    2010-01-01

    BACKGROUND: Recent studies indicate the presence of a small, stem-like cell population in several human cancers that is crucial for the tumour (re)population. OBJECTIVE: Six established prostate cancer (PCa) cell lines-DU145, DuCaP, LAPC-4, 22Rv1, LNCaP, and PC-3-were examined for their stem cell pr

  2. Astrocyte morphology, heterogeneity and density in the developing African Giant Rat (Cricetomys gambianus

    Directory of Open Access Journals (Sweden)

    James Olukayode Olopade

    2015-05-01

    Full Text Available Astrocyte morphologies and heterogeneity were described in male African giant rats (AGR (Cricetomys gambianus, Waterhouse across three age groups (5 neonates, 5 juveniles and 5 adults using Silver impregnation method and immunohistochemistry against glia fibrillary acidic protein (GFAP. Immunopositive cell signaling, cell size and population were least in neonates, followed by adults and juveniles respectively. In neonates, astrocyte processes were mostly detected within the glia limitans of the mid and hind brain; their cell bodies measuring 32±4.8 µm in diameter against 91±5.4µm and 75± 1.9µm in juveniles and adults respectively. Astrocyte heterogeneity in juvenile and adult groups revealed eight subtypes to include fibrous astrocytes chiefly in the corpus callosum and brain stem, protoplasmic astrocytes in the cortex and dentate gyrus (DG; radial glia were found along the olfactory bulb (OB and subventricular zone (SVZ; velate astrocytes were mainly found in the cerebellum and hippocampus; marginal astrocytes close to the pia mater; Bergmann glia in the molecular layer of the cerebellum; perivascular and periventricular astrocytes in the cortex and third ventricle respectively. Cell counts from twelve anatomical regions of the brain were significantly higher in juveniles than in adults (p≤0.01 using unpaired student t-test in the cerebral cortex, pia, corpus callosum, rostral migratory stream (RMS, DG and cerebellum. Highest astrocyte count was found in the DG, while the least count was in the brain stem and sub cortex. Astrocytes along the periventricular layer of the OB are believed to be part of the radial glia system that transport newly formed cells towards the hippocampus and play roles in neurogenesis migration and homeostasis in the AGR. Therefore, astrocyte heterogeneity was examined across age groups in the AGR to determine whether age influences astrocytes population in different regions of the AGR brain and discuss

  3. Interfacial geometry dictates cancer cell tumorigenicity

    Science.gov (United States)

    Lee, Junmin; Abdeen, Amr A.; Wycislo, Kathryn L.; Fan, Timothy M.; Kilian, Kristopher A.

    2016-08-01

    Within the heterogeneous architecture of tumour tissue there exists an elusive population of stem-like cells that are implicated in both recurrence and metastasis. Here, by using engineered extracellular matrices, we show that geometric features at the perimeter of tumour tissue will prime a population of cells with a stem-cell-like phenotype. These cells show characteristics of cancer stem cells in vitro, as well as enhanced tumorigenicity in murine models of primary tumour growth and pulmonary metastases. We also show that interfacial geometry modulates cell shape, adhesion through integrin α5β1, MAPK and STAT activity, and initiation of pluripotency signalling. Our results for several human cancer cell lines suggest that interfacial geometry triggers a general mechanism for the regulation of cancer-cell state. Similar to how a growing tumour can co-opt normal soluble signalling pathways, our findings demonstrate how cancer can also exploit geometry to orchestrate oncogenesis.

  4. Copper handling by astrocytes: insights into neurodegenerative diseases.

    Science.gov (United States)

    Tiffany-Castiglioni, Evelyn; Hong, Sandra; Qian, Yongchang

    2011-12-01

    Copper (Cu) is an essential trace element in the brain that can be toxic at elevated levels. Cu accumulation is a suspected etiology in several neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, and prion-induced disorders. Astrocytes are a proposed depot in the brain for Cu and other metals, including lead (Pb). This article describes the physiological roles of Cu in the central nervous system and in selected neurodegenerative diseases, and reviews evidence that astrocytes accumulate Cu and protect neurons from Cu toxicity. Findings from murine genetic models of Menkes disease and from cell culture models concerning the molecular mechanisms by which astrocytes take up, store, and buffer Cu intracellularly are discussed, as well as potential mechanistic linkages between astrocyte functions in Cu handling and neurodegenerative diseases.

  5. Targeting the osteosarcoma cancer stem cell

    Directory of Open Access Journals (Sweden)

    Qin Ling

    2010-10-01

    Full Text Available Abstract Osteosarcoma is the most common type of solid bone cancer and the second leading cause of cancer-related death in pediatric patients. Many patients are not cured by the current osteosarcoma therapy consisting of combination chemotherapy along with surgery and thus new treatments are urgently needed. In the last decade, cancer stem cells have been identified in many tumors such as leukemia, brain, breast, head and neck, colon, skin, pancreatic, and prostate cancers and these cells are proposed to play major roles in drug resistance, tumor recurrence, and metastasis. Recent studies have shown evidence that osteosarcoma also possesses cancer stem cells. This review summarizes the current knowledge about the osteosarcoma cancer stem cell including the methods used for its isolation, its properties, and its potential as a new target for osteosarcoma treatment.

  6. Extracellular Molecules Involved in Cancer Cell Invasion

    Energy Technology Data Exchange (ETDEWEB)

    Stivarou, Theodora; Patsavoudi, Evangelia, E-mail: epatsavoudi@pasteur.gr [Department of Biochemistry, Hellenic Pasteur Institute, Athens 11521 (Greece); Technological Educational Institute of Athens, Egaleo, Athens 12210 (Greece)

    2015-01-26

    Nowadays it is perfectly clear that understanding and eradicating cancer cell invasion and metastasis represent the crucial, definitive points in cancer therapeutics. During the last two decades there has been a great interest in the understanding of the extracellular molecular mechanisms involved in cancer cell invasion. In this review, we highlight the findings concerning these processes, focusing in particular on extracellular molecules, including extracellular matrix proteins and their receptors, growth factors and their receptors, matrix metalloproteinases and extracellular chaperones. We report the molecular mechanisms underlying the important contribution of this pool of molecules to the complex, multi-step phenomenon of cancer cell invasion.

  7. Extracellular Molecules Involved in Cancer Cell Invasion

    Directory of Open Access Journals (Sweden)

    Theodora Stivarou

    2015-01-01

    Full Text Available Nowadays it is perfectly clear that understanding and eradicating cancer cell invasion and metastasis represent the crucial, definitive points in cancer therapeutics. During the last two decades there has been a great interest in the understanding of the extracellular molecular mechanisms involved in cancer cell invasion. In this review, we highlight the findings concerning these processes, focusing in particular on extracellular molecules, including extracellular matrix proteins and their receptors, growth factors and their receptors, matrix metalloproteinases and extracellular chaperones. We report the molecular mechanisms underlying the important contribution of this pool of molecules to the complex, multi-step phenomenon of cancer cell invasion.

  8. Single-cell analysis in cancer genomics

    Science.gov (United States)

    Saadatpour, Assieh; Lai, Shujing; Guo, Guoji; Yuan, Guo-Cheng

    2017-01-01

    Genetic changes and environmental differences result in cellular heterogeneity among cancer cells within the same tumor, thereby complicating treatment outcomes. Recent advances in single-cell technologies have opened new avenues to characterize the intra-tumor cellular heterogeneity, identify rare cell types, measure mutation rates, and, ultimately, guide diagnosis and treatment. In this paper, we review the recent single-cell technological and computational advances at the genomic, transcriptomic, and proteomic levels, and discuss their applications in cancer research. PMID:26450340

  9. Astrocytic modulation of blood brain barrier: perspectives on Parkinson's disease.

    Science.gov (United States)

    Cabezas, Ricardo; Avila, Marcos; Gonzalez, Janneth; El-Bachá, Ramon Santos; Báez, Eliana; García-Segura, Luis Miguel; Jurado Coronel, Juan Camilo; Capani, Francisco; Cardona-Gomez, Gloria Patricia; Barreto, George E

    2014-01-01

    The blood-brain barrier (BBB) is a tightly regulated interface in the Central Nervous System (CNS) that regulates the exchange of molecules in and out from the brain thus maintaining the CNS homeostasis. It is mainly composed of endothelial cells (ECs), pericytes and astrocytes that create a neurovascular unit (NVU) with the adjacent neurons. Astrocytes are essential for the formation and maintenance of the BBB by providing secreted factors that lead to the adequate association between the cells of the BBB and the formation of strong tight junctions. Under neurological disorders, such as chronic cerebral ischemia, brain trauma, Epilepsy, Alzheimer and Parkinson's Diseases, a disruption of the BBB takes place, involving a lost in the permeability of the barrier and phenotypical changes in both the ECs and astrocytes. In this aspect, it has been established that the process of reactive gliosis is a common feature of astrocytes during BBB disruption, which has a detrimental effect on the barrier function and a subsequent damage in neuronal survival. In this review we discuss the implications of astrocyte functions in the protection of the BBB, and in the development of Parkinson's disease (PD) and related disorders. Additionally, we highlight the current and future strategies in astrocyte protection aimed at the development of restorative therapies for the BBB in pathological conditions.

  10. Astrocytic Insulin Signaling Couples Brain Glucose Uptake with Nutrient Availability.

    Science.gov (United States)

    García-Cáceres, Cristina; Quarta, Carmelo; Varela, Luis; Gao, Yuanqing; Gruber, Tim; Legutko, Beata; Jastroch, Martin; Johansson, Pia; Ninkovic, Jovica; Yi, Chun-Xia; Le Thuc, Ophelia; Szigeti-Buck, Klara; Cai, Weikang; Meyer, Carola W; Pfluger, Paul T; Fernandez, Ana M; Luquet, Serge; Woods, Stephen C; Torres-Alemán, Ignacio; Kahn, C Ronald; Götz, Magdalena; Horvath, Tamas L; Tschöp, Matthias H

    2016-08-11

    We report that astrocytic insulin signaling co-regulates hypothalamic glucose sensing and systemic glucose metabolism. Postnatal ablation of insulin receptors (IRs) in glial fibrillary acidic protein (GFAP)-expressing cells affects hypothalamic astrocyte morphology, mitochondrial function, and circuit connectivity. Accordingly, astrocytic IR ablation reduces glucose-induced activation of hypothalamic pro-opio-melanocortin (POMC) neurons and impairs physiological responses to changes in glucose availability. Hypothalamus-specific knockout of astrocytic IRs, as well as postnatal ablation by targeting glutamate aspartate transporter (GLAST)-expressing cells, replicates such alterations. A normal response to altering directly CNS glucose levels in mice lacking astrocytic IRs indicates a role in glucose transport across the blood-brain barrier (BBB). This was confirmed in vivo in GFAP-IR KO mice by using positron emission tomography and glucose monitoring in cerebral spinal fluid. We conclude that insulin signaling in hypothalamic astrocytes co-controls CNS glucose sensing and systemic glucose metabolism via regulation of glucose uptake across the BBB.

  11. Unveiling astrocytic control of cerebral blood flow with optogenetics.

    Science.gov (United States)

    Masamoto, Kazuto; Unekawa, Miyuki; Watanabe, Tatsushi; Toriumi, Haruki; Takuwa, Hiroyuki; Kawaguchi, Hiroshi; Kanno, Iwao; Matsui, Ko; Tanaka, Kenji F; Tomita, Yutaka; Suzuki, Norihiro

    2015-06-16

    Cortical neural activities lead to changes in the cerebral blood flow (CBF), which involves astrocytic control of cerebrovascular tone. However, the manner in which astrocytic activity specifically leads to vasodilation or vasoconstriction is difficult to determine. Here, cortical astrocytes genetically expressing a light-sensitive cation channel, channelrhodopsin-2 (ChR2), were transcranially activated with a blue laser while the spatiotemporal changes in CBF were noninvasively monitored with laser speckle flowgraphy in the anesthetised mouse cortex. A brief photostimulation induced a fast transient increase in CBF. The average response onset time was 0.7 ± 0.7 sec at the activation foci, and this CBF increase spread widely from the irradiation spot with an apparent propagation speed of 0.8-1.1 mm/sec. The broad increase in the CBF could be due to a propagation of diffusible vasoactive signals derived from the stimulated astrocytes. Pharmacological manipulation showed that topical administration of a K(+) channel inhibitor (BaCl2; 0.1-0.5 mM) significantly reduced the photostimulation-induced CBF responses, which indicates that the ChR2-evoked astrocytic activity involves K(+) signalling to the vascular smooth muscle cells. These findings demonstrate a unique model for exploring the role of the astrocytes in gliovascular coupling using non-invasive, time-controlled, cell-type specific perturbations.

  12. Engineered metal nanoparticles in the sub-nanomolar levels kill cancer cells

    Directory of Open Access Journals (Sweden)

    Vodyanoy V

    2016-04-01

    Full Text Available Vitaly Vodyanoy,1 Yasmine Daniels,2 Oleg Pustovyy,1 William A MacCrehan,2 Shin Muramoto,2 Gheorghe Stan21Department of Anatomy, Physiology and Pharmacology, Auburn University College of Veterinary Medicine, Auburn, AL, 2Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MA, USA Background: Small metal nanoparticles obtained from animal blood were observed to be toxic to cultured cancer cells, whereas noncancerous cells were much less affected. In this work, engineered zinc and copper metal nanoparticles were produced from bulk metal rods by an underwater high-voltage discharge method. The metal nanoparticles were characterized by atomic force microscopy and X-ray photoelectron spectroscopy. The metal nanoparticles, with estimated diameters of 1 nm–2 nm, were determined to be more than 85% nonoxidized. A cell viability assay and high-resolution light microscopy showed that exposure of RG2, cultured rat brain glioma cancer cells, to the zinc and copper nanoparticles resulted in cell morphological changes, including decreased cell adherence, shrinking/rounding, nuclear condensation, and budding from cell bodies. The metal-induced cell injuries were similar to the effects of staurosporine, an active apoptotic reagent. The viability experiments conducted for zinc and copper yielded values of dissociation constants of 0.22±0.08 nmol/L (standard error [SE] and 0.12±0.02 nmol/L (SE, respectively. The noncancerous astrocytes were not affected at the same conditions. Because metal nanoparticles were lethal to the cancer cells at sub-nanomolar concentrations, they are potentially important as nanomedicine.Purpose: Lethal concentrations of synthetic metal nanoparticles reported in the literature are a few orders of magnitude higher than the natural, blood-isolated metal nanoparticles; therefore, in this work, engineered metal nanoparticles were examined to mimic the properties of endogenous metal

  13. Cell type-specific dependency on the PI3K/Akt signaling pathway for the endogenous Epo and VEGF induction by baicalein in neurons versus astrocytes.

    Directory of Open Access Journals (Sweden)

    Yu-Yo Sun

    Full Text Available The neuroprotective effect of baicalein is generally attributed to inhibition of 12/15-lipoxygenase (12/15-LOX and suppression of oxidative stress, but recent studies showed that baicalein also activates hypoxia-inducible factor-α (HIF1α through inhibition of prolyl hydrolase 2 (PHD2 and activation of the phosphatidylinositide-3 kinase (PI3K/Akt signaling pathway. Yet, the significance and regulation of prosurvival cytokines erythropoietin (Epo and vascular endothelial growth factor (VEGF, two transcriptional targets of HIF1α, in baicalein-mediated neuroprotection in neurons and astrocytes remains unknown. Here we investigated the causal relationship between the PI3K/Akt signaling pathway and Epo/VEGF expression in baicalein-mediated neuroprotection in primary rat cortical neurons and astrocytes. Our results show that baicalein induced Epo and VEGF expression in a HIF1α- and PI3K/Akt-dependent manner in neurons. Baicalein also protected neurons against excitotoxicity in a PI3K- and Epo/VEGF-dependent manner without affecting neuronal excitability. In contrast, at least a 10-fold higher concentration of baicalein was needed to induce Epo/VEGF production and PI3K/Akt activity in astrocytes for protection of neurons. Moreover, only baicalein-induced astrocytic VEGF, but not Epo expression requires HIF1α, while PI3K/Akt signaling had little role in baicalein-induced astrocytic Epo/VEGF expression. These results suggest distinct mechanisms of baicalein-mediated Epo/VEGF production in neurons and astrocytes for neuroprotection, and provide new insights into the mechanisms and potential of baicalein in treating brain injury in vivo.

  14. Cell type-specific dependency on the PI3K/Akt signaling pathway for the endogenous Epo and VEGF induction by baicalein in neurons versus astrocytes.

    Science.gov (United States)

    Sun, Yu-Yo; Lin, Shang-Hsuan; Lin, Hung-Cheng; Hung, Chia-Chi; Wang, Chen-Yu; Lin, Yen-Chu; Hung, Kuo-Sheng; Lien, Cheng-Chang; Kuan, Chia-Yi; Lee, Yi-Hsuan

    2013-01-01

    The neuroprotective effect of baicalein is generally attributed to inhibition of 12/15-lipoxygenase (12/15-LOX) and suppression of oxidative stress, but recent studies showed that baicalein also activates hypoxia-inducible factor-α (HIF1α) through inhibition of prolyl hydrolase 2 (PHD2) and activation of the phosphatidylinositide-3 kinase (PI3K)/Akt signaling pathway. Yet, the significance and regulation of prosurvival cytokines erythropoietin (Epo) and vascular endothelial growth factor (VEGF), two transcriptional targets of HIF1α, in baicalein-mediated neuroprotection in neurons and astrocytes remains unknown. Here we investigated the causal relationship between the PI3K/Akt signaling pathway and Epo/VEGF expression in baicalein-mediated neuroprotection in primary rat cortical neurons and astrocytes. Our results show that baicalein induced Epo and VEGF expression in a HIF1α- and PI3K/Akt-dependent manner in neurons. Baicalein also protected neurons against excitotoxicity in a PI3K- and Epo/VEGF-dependent manner without affecting neuronal excitability. In contrast, at least a 10-fold higher concentration of baicalein was needed to induce Epo/VEGF production and PI3K/Akt activity in astrocytes for protection of neurons. Moreover, only baicalein-induced astrocytic VEGF, but not Epo expression requires HIF1α, while PI3K/Akt signaling had little role in baicalein-induced astrocytic Epo/VEGF expression. These results suggest distinct mechanisms of baicalein-mediated Epo/VEGF production in neurons and astrocytes for neuroprotection, and provide new insights into the mechanisms and potential of baicalein in treating brain injury in vivo.

  15. Regulation of neurotrophic factors and energy metabolism by antidepressants in astrocytes

    KAUST Repository

    Martin, Jean Luc

    2013-09-01

    There is growing evidence that astrocytes are involved in the neuropathology of major depression. In particular, decreases in glial cell density observed in the cerebral cortex of individuals with major depressive disorder are accompanied by a reduction of several astrocytic markers suggesting that astrocyte dysfunction may contribute to the pathophysiology of major depression. In rodents, glial loss in the prefrontal cortex is sufficient to induce depressive-like behaviors and antidepressant treatment prevents the stress-induced reduction of astrocyte number in the hippocampus. Collectively, these data support the existence of a link between astrocyte loss or dysfunction, depressive-like behavior and antidepressant treatment. Astrocytes are increasingly recognized to play important roles in neuronal development, neurotransmission, synaptic plasticity and maintenance of brain homeostasis. It is also well established that astrocytes provide trophic, structural, and metabolic support to neurons. In this article, we review evidence that antidepressants regulate energy metabolism and neurotrophic factor expression with particular emphasis on studies in astrocytes. These observations support a role for astrocytes as new targets for antidepressants. The contribution of changes in astrocyte glucose metabolism and neurotrophic factor expression to the therapeutic effects of antidepressants remains to be established. © 2013 Bentham Science Publishers.

  16. Calcium Imaging of Living Astrocytes in the Mouse Spinal Cord following Sensory Stimulation

    Directory of Open Access Journals (Sweden)

    Giovanni Cirillo

    2012-01-01

    Full Text Available Astrocytic Ca2+ dynamics have been extensively studied in ex vivo models; however, the recent development of two-photon microscopy and astrocyte-specific labeling has allowed the study of Ca2+ signaling in living central nervous system. Ca2+ waves in astrocytes have been described in cultured cells and slice preparations, but evidence for astrocytic activation during sensory activity is lacking. There are currently few methods to image living spinal cord: breathing and heart-beating artifacts have impeded the widespread application of this technique. We here imaged the living spinal cord by two-photon microscopy in C57BL6/J mice. Through pressurized injection, we specifically loaded spinal astrocytes using the red fluorescent dye sulforhodamine 101 (SR101 and imaged astrocytic Ca2+ levels with Oregon-Green BAPTA-1 (OGB. Then, we studied astrocytic Ca2+ levels at rest and after right electrical hind paw stimulation. Sensory stimulation significantly increased astrocytic Ca2+ levels within the superficial dorsal horn of the spinal cord compared to rest. In conclusion, in vivo morphofunctional imaging of living astrocytes in spinal cord revealed that astrocytes actively participate to sensory stimulation.

  17. Fibrous and protoplasmic astrocytes express GABAA receptors that differ in benzodiazepine pharmacology.

    Science.gov (United States)

    Rosewater, K; Sontheimer, H

    1994-02-04

    Astrocytes cultured from spinal cord contain two morphologically distinguishable types of astrocytes: fibrous and protoplasmic cells. Both astrocyte subtypes, in culture, are able to express GABAA receptors, and their activation results in inward currents at the resting potential. Using patch-clamp electrophysiology we characterized their basic receptor pharmacology and compared it to spinal cord neurons that were also present in small numbers in these cultures. As in neuronal GABAA receptors, the local anesthetic pentobarbital effectively potentiated GABA-induced currents in both astrocyte subtypes. Similarly, the benzodiazepine diazepam, on average doubled GABA-induced currents in both astrocytes subtypes. In contrast to these effects that were similar in both astrocytes types and similar to spinal cord neurons, the response to the convulsant methyl-4-ethyl-6,7-dimethoxy-beta-carboline-3-carboxylate (DMCM), which is an inverse benzodiazepine agonist differs between astrocyte subtypes. DMCM reduced GABA-induced currents by about 50% in fibrous astrocytes as we also observed with spinal cord neurons. In contrast, DMCM increased GABA currents in protoplasmic astrocytes by up to 150%, an effect never observed in neurons. DMCM potentiations of GABA currents have recently been attributed to differences in receptor subunit composition. Our results thus indicate that subtypes of astrocytes express GABAA receptors that differ pharmacologically and likely differ also in subunit composition.

  18. An immunosurveillance mechanism controls cancer cell ploidy.

    Science.gov (United States)

    Senovilla, Laura; Vitale, Ilio; Martins, Isabelle; Tailler, Maximilien; Pailleret, Claire; Michaud, Mickaël; Galluzzi, Lorenzo; Adjemian, Sandy; Kepp, Oliver; Niso-Santano, Mireia; Shen, Shensi; Mariño, Guillermo; Criollo, Alfredo; Boilève, Alice; Job, Bastien; Ladoire, Sylvain; Ghiringhelli, François; Sistigu, Antonella; Yamazaki, Takahiro; Rello-Varona, Santiago; Locher, Clara; Poirier-Colame, Vichnou; Talbot, Monique; Valent, Alexander; Berardinelli, Francesco; Antoccia, Antonio; Ciccosanti, Fabiola; Fimia, Gian Maria; Piacentini, Mauro; Fueyo, Antonio; Messina, Nicole L; Li, Ming; Chan, Christopher J; Sigl, Verena; Pourcher, Guillaume; Ruckenstuhl, Christoph; Carmona-Gutierrez, Didac; Lazar, Vladimir; Penninger, Josef M; Madeo, Frank; López-Otín, Carlos; Smyth, Mark J; Zitvogel, Laurence; Castedo, Maria; Kroemer, Guido

    2012-09-28

    Cancer cells accommodate multiple genetic and epigenetic alterations that initially activate intrinsic (cell-autonomous) and extrinsic (immune-mediated) oncosuppressive mechanisms. Only once these barriers to oncogenesis have been overcome can malignant growth proceed unrestrained. Tetraploidization can contribute to oncogenesis because hyperploid cells are genomically unstable. We report that hyperploid cancer cells become immunogenic because of a constitutive endoplasmic reticulum stress response resulting in the aberrant cell surface exposure of calreticulin. Hyperploid, calreticulin-exposing cancer cells readily proliferated in immunodeficient mice and conserved their increased DNA content. In contrast, hyperploid cells injected into immunocompetent mice generated tumors only after a delay, and such tumors exhibited reduced DNA content, endoplasmic reticulum stress, and calreticulin exposure. Our results unveil an immunosurveillance system that imposes immunoselection against hyperploidy in carcinogen- and oncogene-induced cancers.

  19. Ionizing radiation induces stemness in cancer cells.

    Directory of Open Access Journals (Sweden)

    Laura Ghisolfi

    Full Text Available The cancer stem cell (CSC model posits the presence of a small number of CSCs in the heterogeneous cancer cell population that are ultimately responsible for tumor initiation, as well as cancer recurrence and metastasis. CSCs have been isolated from a variety of human cancers and are able to generate a hierarchical and heterogeneous cancer cell population. CSCs are also resistant to conventional chemo- and radio-therapies. Here we report that ionizing radiation can induce stem cell-like properties in heterogeneous cancer cells. Exposure of non-stem cancer cells to ionizing radiation enhanced spherogenesis, and this was accompanied by upregulation of the pluripotency genes Sox2 and Oct3/4. Knockdown of Sox2 or Oct3/4 inhibited radiation-induced spherogenesis and increased cellular sensitivity to radiation. These data demonstrate that ionizing radiation can activate stemness pathways in heterogeneous cancer cells, resulting in the enrichment of a CSC subpopulation with higher resistance to radiotherapy.

  20. Cancer Stem Cells and Side Population Cells in Breast Cancer and Metastasis

    Energy Technology Data Exchange (ETDEWEB)

    Britton, Kelly M. [Institute of Genetic Medicine, Newcastle University, International Centre for Life, Central Parkway, Newcastle-upon-Tyne, NE1 3BZ (United Kingdom); Kirby, John A. [Institute of Cellular Medicine, Newcastle University, 3rd Floor William Leech Building, Framlington Place, Newcastle-upon-Tyne, NE2 4HH (United Kingdom); Lennard, Thomas W.J. [Faculty of Medical Sciences, Newcastle University, 3rd Floor William Leech Building, Framlington Place, Newcastle-upon-Tyne, NE2 4HH (United Kingdom); Meeson, Annette P., E-mail: annette.meeson@ncl.ac.uk [Institute of Genetic Medicine, Newcastle University, International Centre for Life, Central Parkway, Newcastle-upon-Tyne, NE1 3BZ (United Kingdom); North East England Stem Cell Institute, Bioscience Centre, International Centre for Life, Central Parkway, Newcastle-upon-Tyne, NE1 3BZ (United Kingdom)

    2011-04-19

    In breast cancer it is never the primary tumour that is fatal; instead it is the development of metastatic disease which is the major cause of cancer related mortality. There is accumulating evidence that suggests that Cancer Stem Cells (CSC) may play a role in breast cancer development and progression. Breast cancer stem cell populations, including side population cells (SP), have been shown to be primitive stem cell-like populations, being long-lived, self-renewing and highly proliferative. SP cells are identified using dual wavelength flow cytometry combined with Hoechst 33342 dye efflux, this ability is due to expression of one or more members of the ABC transporter family. They have increased resistance to chemotherapeutic agents and apoptotic stimuli and have increased migratory potential above that of the bulk tumour cells making them strong candidates for the metastatic spread of breast cancer. Treatment of nearly all cancers usually involves one first-line agent known to be a substrate of an ABC transporter thereby increasing the risk of developing drug resistant tumours. At present there is no marker available to identify SP cells using immunohistochemistry on breast cancer patient samples. If SP cells do play a role in breast cancer progression/Metastatic Breast Cancer (MBC), combining chemotherapy with ABC inhibitors may be able to destroy both the cells making up the bulk tumour and the cancer stem cell population thus preventing the risk of drug resistant disease, recurrence or metastasis.

  1. Mast cells and cancer: enemies or allies?

    Science.gov (United States)

    Dyduch, Grzegorz; Kaczmarczyk, Karolina; Okoń, Krzysztof

    2012-03-01

    Mast cells are a component of cancer microenvironment the role of which is complex and poorly understood. Mast cells promote cancer growth by stimulation of neoangiogenesis, tissue remodeling and by modulation of the host immune response. The mediators of cancer promotion include protease-activated receptors, mitogen activated protein kinases, prostaglandins and histamine. Histamine may induce tumor proliferation and immunosuppression through H1 and H2 receptors, respectively. The mast cell-derived modulators of immune response include also interleukin 10 (IL-10), tumor necrosis factor α (TNF-α) and CD30L. Possibly stimulation of angiogenesis is the most important. Mast cells release potent proangiogenic factors such as vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), transforming growth factor β (TGF-β), TNF- α and IL-8, and mast cells' enzymes, like metaloproteinases (MMPs), tryptase and chymase participate in vessels' formation. The anti-cancer actions of mast cells include direct growth inhibition, immunologic stimulation, inhibition of apoptosis and decreased cell mobility; the mediators of these processes include chymase, tryptase, TNF-α, IL-1 and IL-6. The very same mediators may exert both pro- or anti-cancer effects depending on concentration, presence of cofactors or location of secreting cells. In fact, peri- and intra-tumoral mast cells may have dissimilar effects. Understanding of the role of mast cells in cancer could lead to improved prognostication and development of therapeutic methods targeting the mast cells.

  2. Astrocytes as a source for Extracellular matrix molecules and cytokines

    Directory of Open Access Journals (Sweden)

    Stefan eWiese

    2012-06-01

    Full Text Available Research of the past 25 years has shown that astrocytes do more than participating and building up the blood brain barrier and detoxify the active synapse by reuptake of neurotransmitters and ions. Indeed, astrocytes express neurotransmitter receptors and, as a consequence, respond to stimuli. Deeper knowledge of the differentiation processes during development of the central nervous system (CNS might help explaining and even help treating neurological diseases like Alzheimer’s disease, Amyotrophic lateral sclerosis (ALS and psychiatric disorders in which astrocytes have been shown to play a role. Astrocytes and oligodendrocytes develop from a multipotent stem cell that prior to this has produced primarily neuronal precursor cells. This switch towards the more astroglial differentiation is regulated by a change in receptor composition on the cell surface and responsiveness of the respective trophic factors Fibroblast growth factor (FGF and Epidermal growth factor (EGF. The glial precursor cell is driven into the astroglial direction by signaling molecules like Ciliary neurotrophic factor (CNTF, Bone Morphogenetic Proteins (BMPs, and EGF. However, the early astrocytes influence their environment not only by releasing and responding to diverse soluble factors but also express a wide range of extracellular matrix (ECM molecules, in particular proteoglycans of the lectican family and tenascins. Lately these ECM molecules have been shown to participate in glial development. In this regard, especially the matrix protein Tenascin C (Tnc proved to be an important regulator of astrocyte precursor cell proliferation and migration during spinal cord development. On the other hand, ECM molecules expressed by reactive astrocytes are also known to act mostly in an inhibitory fashion under pathophysiological conditions. In this regard, we further summarize recent data concerning the role of chondroitin sulfate proteoglycans and Tnc under pathological

  3. Dendritic cell-based cancer immunotherapy for colorectal cancer.

    Science.gov (United States)

    Kajihara, Mikio; Takakura, Kazuki; Kanai, Tomoya; Ito, Zensho; Saito, Keisuke; Takami, Shinichiro; Shimodaira, Shigetaka; Okamoto, Masato; Ohkusa, Toshifumi; Koido, Shigeo

    2016-05-01

    Colorectal cancer (CRC) is one of the most common cancers and a leading cause of cancer-related mortality worldwide. Although systemic therapy is the standard care for patients with recurrent or metastatic CRC, the prognosis is extremely poor. The optimal sequence of therapy remains unknown. Therefore, alternative strategies, such as immunotherapy, are needed for patients with advanced CRC. This review summarizes evidence from dendritic cell-based cancer immunotherapy strategies that are currently in clinical trials. In addition, we discuss the possibility of antitumor immune responses through immunoinhibitory PD-1/PD-L1 pathway blockade in CRC patients.

  4. Wnt Signaling in Cancer Stem Cell Biology.

    Science.gov (United States)

    de Sousa E Melo, Felipe; Vermeulen, Louis

    2016-06-27

    Aberrant regulation of Wnt signaling is a common theme seen across many tumor types. Decades of research have unraveled the epigenetic and genetic alterations that result in elevated Wnt pathway activity. More recently, it has become apparent that Wnt signaling levels identify stem-like tumor cells that are responsible for fueling tumor growth. As therapeutic targeting of these tumor stem cells is an intense area of investigation, a concise understanding on how Wnt activity relates to cancer stem cell traits is needed. This review attempts at summarizing the intricacies between Wnt signaling and cancer stem cell biology with a special emphasis on colorectal cancer.

  5. Breast cancer stem cells and radiation

    Science.gov (United States)

    Phillips, Tiffany Marie

    2007-12-01

    The present studies explore the response of breast cancer stem cells (BCSC's) to radiation and the implications for clinical cancer treatment. Current cancer therapy eliminates bulky tumor mass but may fail to eradicate a critical tumor initiating cell population termed "cancer stem cells". These cells are potentially responsible for tumor formation, metastasis, and recurrence. Recently cancer stem cells have been prospectively identified in various malignancies, including breast cancer. The breast cancer stem cell has been identified by the surface markers CD44+/CD24 -(low). In vitro mammosphere cultures allow for the enrichment of the cancer stem cell population and were utilized in order to study differential characteristics of BCSC's. Initial studies found that BCSC's display increased radiation resistance as compared to other non-stem tumor cells. This resistance was accompanied by decreased H2AX phosphorylation, decreased reactive oxygen species formation, and increased phosphorylation of the checkpoint protein Chk1. These studies suggest differential DNA damage and repair within the BCSC population. Studies then examined the consequences of fractionated radiation on the BCSC population and found a two-fold increase in BCSC's following 5 x 3Gy. This observation begins to tie cancer stem cell self-renewal to the clinical stem cell phenomenon of accelerated repopulation. Accelerated repopulation is observed when treatment gaps increase between sequential fractions of radiotherapy and may be due to cancer stem cell symmetric self-renewal. The balance between asymmetric and symmetric stem cell division is vital for proper maintenance; deregulation is likely linked to cancer initiation and progression. The developmental Notch-1 pathway was found to regulate BCSC division. Over-expressing the constitutively active Notch-1-ICD in MCF7 cells produced an increase in the BCSC population. Additionally, radiation was observed to increase the expression of the Notch-1

  6. Laminins containing the β2 and γ3 chains regulate astrocyte migration and angiogenesis in the retina.

    Science.gov (United States)

    Gnanaguru, Gopalan; Bachay, Galina; Biswas, Saptarshi; Pinzón-Duarte, Germán; Hunter, Dale D; Brunken, William J

    2013-05-01

    Pathologies of retinal blood vessels are among the major causes of blindness worldwide. A key cell type that regulates retinal vascular development is the astrocyte. Generated extrinsically to the retina, astrocytes migrate into the retina through the optic nerve head. Even though there is a strong correlation between astrocyte distribution and retinal vascular development, the factors that guide astrocytes into the retina remain unclear. In this study, we show that astrocytes migrate within a laminin-containing basement membrane - the inner limiting membrane. Genetic deletion of the laminin β2 and γ3 chains affects astrocyte migration and spatial distribution. We show that laminins act as haptotactic factors in vitro in an isoform-specific manner, inducing astrocyte migration and promoting astrocyte differentiation. The addition of exogenous laminins to laminin-null retinal explants rescues astrocyte migration and spatial patterning. Furthermore, we show that the loss of laminins reduces β1 integrin expression in astrocytes. Culturing laminin-null retinal astrocytes on laminin substrates restores focal localization of β1 integrin. Finally, we show that laminins containing β2 and γ3 chains regulate subsequent retinal blood vessel growth and maintain vascular integrity. These in vivo and in vitro studies demonstrate clearly that laminins containing β2 and γ3 chains are indispensable for migration and spatial organization of astrocytes and that they play a crucial role during retinal angiogenesis in vivo.

  7. Relevance of mortalin to cancer cell stemness and cancer therapy.

    Science.gov (United States)

    Yun, Chae-Ok; Bhargava, Priyanshu; Na, Youjin; Lee, Jung-Sun; Ryu, Jihoon; Kaul, Sunil C; Wadhwa, Renu

    2017-02-06

    Mortalin/mtHsp70 is a member of Hsp70 family of proteins. Enriched in a large variety of cancers, it has been shown to contribute to the process of carcinogenesis by multiple ways including inactivation of tumor suppressor p53 protein, deregulation of apoptosis and activation of EMT signaling. In this study, we report that upregulation of mortalin contributes to cancer cell stemness. Several cancer cell stemness markers, such as ABCG2, OCT-4, CD133, ALDH1, CD9, MRP1 and connexin were upregulated in mortalin-overexpressing cells that showed higher ability to form spheroids. These cells also showed higher migration, and were less responsive to a variety of cancer chemotherapeutic drugs. Of note, knockdown of mortalin by specific shRNA sensitized these cells to all the drugs used in this study. We report that low doses of anti-mortalin molecules, MKT-077 and CAPE, also caused similar sensitization of cancer cells to chemotherapeutic drugs and hence are potential candidates for effective cancer chemotherapy.

  8. Relevance of mortalin to cancer cell stemness and cancer therapy

    Science.gov (United States)

    Yun, Chae-Ok; Bhargava, Priyanshu; Na, Youjin; Lee, Jung-Sun; Ryu, Jihoon; Kaul, Sunil C.; Wadhwa, Renu

    2017-01-01

    Mortalin/mtHsp70 is a member of Hsp70 family of proteins. Enriched in a large variety of cancers, it has been shown to contribute to the process of carcinogenesis by multiple ways including inactivation of tumor suppressor p53 protein, deregulation of apoptosis and activation of EMT signaling. In this study, we report that upregulation of mortalin contributes to cancer cell stemness. Several cancer cell stemness markers, such as ABCG2, OCT-4, CD133, ALDH1, CD9, MRP1 and connexin were upregulated in mortalin-overexpressing cells that showed higher ability to form spheroids. These cells also showed higher migration, and were less responsive to a variety of cancer chemotherapeutic drugs. Of note, knockdown of mortalin by specific shRNA sensitized these cells to all the drugs used in this study. We report that low doses of anti-mortalin molecules, MKT-077 and CAPE, also caused similar sensitization of cancer cells to chemotherapeutic drugs and hence are potential candidates for effective cancer chemotherapy. PMID:28165047

  9. The similarity of astrocytes number in dentate gyrus and CA3 subfield of rats hippocampus.

    Science.gov (United States)

    Jahanshahi, Mehrdad; Sadeghi, Y; Hosseini, A; Naghdi, N

    2007-01-01

    The dentate gyrus is a part of hippocampal formation that it contains granule cells, which project to the pyramidal cells and interneurons of the CA3 subfield of the hippocampus. Astrocytes play a more active role in neuronal activity, including regulating ion flux currents, energy production, neurotransmitter release and synaptogenesis. Astrocytes are the only cells in the brain that contain the energy molecule glycogen. The close relationship between dentate gyrus and CA3 area can cause the similarity of the number of astrocytes in these areas. In this study 5 male albino wistar rats were used. Rats were housed in large plastic cage in animal house and were maintained under standard conditions, after histological processing, The 7 microm slides of the brains were stained with PTAH staining for showing the astrocytes. This staining is specialized for astrocytes. We showed that the number of astrocytes in different (ant., mid., post) parts of dentate gyrus and CA3 of hippocampus is the same. For example, the anterior parts of two area have the most number of astrocytes and the middle parts of two area have the least number of astrocytes. We concluded that dentate gyrus and CA3 area of hippocampus have the same group of astrocytes.

  10. Repression of cancer cell senescence by PKCι.

    Science.gov (United States)

    Paget, J A; Restall, I J; Daneshmand, M; Mersereau, J A; Simard, M A; Parolin, D A E; Lavictoire, S J; Amin, M S; Islam, S; Lorimer, I A J

    2012-08-02

    Senescence is an irreversible growth arrest phenotype adopted by cells that has a key role in protecting organisms from cancer. There is now considerable interest in therapeutic strategies that reactivate this process to control the growth of cancer cells. Protein kinase-Cι (PKCι) is a member of the atypical PKC family and an important downstream mediator in the phosphoinositide-3-kinase (PI-3-kinase) pathway. PKCι expression was found to be upregulated in a subset of breast cancers and breast cancer cell lines. Activation of the PI-3-kinase pathway by introduction of mutant, oncogenic PIK3CA into breast mammary epithelial cells increased both the expression and activation of PKCι. In breast cancer cells lines overexpressing PKCι, depletion of PKCι increased the number of senescent cells, as assessed by senescence-associated β-galactosidase, morphology and bromodeoxyuridine incorporation. This phenomenon was not restricted to breast cancer cells, as it was also seen in glioblastoma cells in which PKCι is activated by loss of PTEN. Senescence occurred in the absence of a detectable DNA-damage response, was dependent on p21 and was enhanced by the aurora kinase inhibitor VX-680, suggesting that senescence is triggered by defects in mitosis. Depletion of PKCι had no effect on senescence in normal mammary epithelial cell lines. We conclude that PKCι is overexpressed in a subset of cancers where it functions to suppress premature senescence. This function appears to be restricted to cancer cells and inhibition of PKCι may therefore be an effective way to selectively activate premature senescence in cancer cells.

  11. Astrocyte-neuron co-culture on microchips based on the model of SOD mutation to mimic ALS.

    Science.gov (United States)

    Kunze, Anja; Lengacher, Sylvain; Dirren, Elisabeth; Aebischer, Patrick; Magistretti, Pierre J; Renaud, Philippe

    2013-07-24

    Amyotrophic lateral sclerosis (ALS) is the most common motor neuron disease. ALS is believed to be a non-cell autonomous condition, as other cell types, including astrocytes, have been implicated in disease pathogenesis. Hence, to facilitate the development of therapeutics against ALS, it is crucial to better understand the interactions between astrocytes and neural cells. Furthermore, cell culture assays are needed that mimic the complexity of cell to cell communication at the same time as they provide control over the different microenvironmental parameters. Here, we aim to validate a previously developed microfluidic system for an astrocyte-neuron cell culture platform, in which astrocytes have been genetically modified to overexpress either a human wild-type (WT) or a mutated form of the super oxide dismutase enzyme 1 (SOD1). Cortical neural cells were co-cultured with infected astrocytes and studied for up to two weeks. Using our microfluidic device that prevents direct cell to cell contact, we could evaluate neural cell response in the vicinity of astrocytes. We showed that neuronal cell density was reduced by about 45% when neurons were co-cultured with SOD-mutant astrocytes. Moreover, we demonstrated that SOD-WT overexpressing astrocytes reduced oxidative stress on cortical neurons that were in close metabolic contact. In contrast, cortical neurons in metabolic contact with SOD-mutant astrocytes lost their synapsin protein expression after severe glutamate treatment, an indication of the toxicity potentiating effect of the SOD-mutant enzyme.

  12. Redox Regulation in Cancer Stem Cells

    Directory of Open Access Journals (Sweden)

    Shijie Ding

    2015-01-01

    Full Text Available Reactive oxygen species (ROS and ROS-dependent (redox regulation signaling pathways and transcriptional activities are thought to be critical in stem cell self-renewal and differentiation during growth and organogenesis. Aberrant ROS burst and dysregulation of those ROS-dependent cellular processes are strongly associated with human diseases including many cancers. ROS levels are elevated in cancer cells partially due to their higher metabolism rate. In the past 15 years, the concept of cancer stem cells (CSCs has been gaining ground as the subpopulation of cancer cells with stem cell-like properties and characteristics have been identified in various cancers. CSCs possess low levels of ROS and are responsible for cancer recurrence after chemotherapy or radiotherapy. Unfortunately, how CSCs control ROS production and scavenging and how ROS-dependent signaling pathways contribute to CSCs function remain poorly understood. This review focuses on the role of redox balance, especially in ROS-dependent cellular processes in cancer stem cells (CSCs. We updated recent advances in our understanding of ROS generation and elimination in CSCs and their effects on CSC self-renewal and differentiation through modulating signaling pathways and transcriptional activities. The review concludes that targeting CSCs by manipulating ROS metabolism/dependent pathways may be an effective approach for improving cancer treatment.

  13. [Novel function of astrocytes revealed by optogenetics].

    Science.gov (United States)

    Beppu, Kaoru; Matsui, Ko

    2014-12-01

    Astrocytes respond to neuronal activity. However, whether astrocytic activity has any significance in brain function is unknown. Signaling pathway leading from astrocytes to neurons would be required for astrocytes to participate in neuronal functions and, here, we investigated the presence of such pathway. Optogenetics was used to manipulate astrocytic activity. A light-sensitive protein, channelrhodopsin-2 (ChR2), was selectively expressed in astrocytes. Photostimulation of these astrocytes induced glutamate release which modulated neuronal activity and animal behavior. Such glutamate release was triggered by intracellular acidification produced by ChR2 photoactivation. Astrocytic acidification occurs upon brain ischemia, and we found that another optogenetic tool, archaerhodopsin (ArchT), could counter the acidification and suppress astrocytic glutamate release. Controlling of astrocytic pH may become a therapeutic strategy upon ischemia.

  14. Astrocytes from familial and sporadic ALS patients are toxic to motor neurons.

    Science.gov (United States)

    Haidet-Phillips, Amanda M; Hester, Mark E; Miranda, Carlos J; Meyer, Kathrin; Braun, Lyndsey; Frakes, Ashley; Song, SungWon; Likhite, Shibi; Murtha, Matthew J; Foust, Kevin D; Rao, Meghan; Eagle, Amy; Kammesheidt, Anja; Christensen, Ashley; Mendell, Jerry R; Burghes, Arthur H M; Kaspar, Brian K

    2011-08-10

    Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron disease, with astrocytes implicated as contributing substantially to motor neuron death in familial (F)ALS. However, the proposed role of astrocytes in the pathology of ALS derives in part from rodent models of FALS based upon dominant mutations within the superoxide dismutase 1 (SOD1) gene, which account for 90% of ALS patients, remains to be established. Using astrocytes generated from postmortem tissue from both FALS and SALS patients, we show that astrocytes derived from both patient groups are similarly toxic to motor neurons. We also demonstrate that SOD1 is a viable target for SALS, as its knockdown significantly attenuates astrocyte-mediated toxicity toward motor neurons. Our data highlight astrocytes as a non-cell autonomous component in SALS and provide an in vitro model system to investigate common disease mechanisms and evaluate potential therapies for SALS and FALS.

  15. Metabolic aspects of Neuronal – Oligodendrocytic - Astrocytic (NOA interactions

    Directory of Open Access Journals (Sweden)

    Ana I Amaral

    2013-05-01

    Full Text Available Whereas astrocytes have been in the limelight on the metabolic glucose interaction scene for a while, oligodendrocytes are still waiting for a place. We would like to call oligodendrocyte interaction with astrocytes and neurons: NOA (neuron – oligodendrocyte – astrocyte interactions. One of the reasons to find out more about oligodendrocyte interaction with neurons and astrocytes is to detect markers of healthy oligodendrocyte metabolism, to be used in diagnosis and treatment assessment in diseases such as Perinatal hypoxic-ischemic encephalopathy and multiple sclerosis in which oligodendrocyte function is impaired, possibly due to glutamate toxicity. Glutamate receptors are expressed in oligodendrocytes and also vesicular glutamate release in the white matter has received considerable attention. It is also important to establish if the glial precursor cells recruited to damaged areas are developing oligodendrocyte characteristics or those of astrocytes. Thus, it is important to study astrocytes and oligodendrocytes separately to be able to differentiate between them. This is of particular importance in the white matter where the number of oligodendrocytes is considerable. The present review summarizes the not very extensive information published on glucose metabolism in oligodendrocytes in an attempt to stimulate research into this important field.

  16. Are astrocytes central players in the pathophysiology of multiple sclerosis?

    NARCIS (Netherlands)

    De Keyser, J; Zeinstra, E; Frohman, E

    2003-01-01

    An interaction between antimyelin T cells and antigen-presenting glial cells is a crucial step in the cascade of immune events that lead to the inflammatory lesions in multiple sclerosis (MS). One of the most debated and controversial issues is whether microglial cells or astrocytes are the key play

  17. Nucleolar function and size in cancer cells.

    OpenAIRE

    Derenzini, M; Trerè, D; Pession, A; Montanaro, L; Sirri, V.; Ochs, R. L.

    1998-01-01

    We have have studied the relationship between nucleolar function and size and cell doubling time in cancer cells. Seven human cancer cell lines characterized by different proliferation rates were used. Nucleolar functional activity was evaluated by measuring RNA polymerase I activity and expression of RNA polymerase I upstream binding factor (UBF), DNA topoisomerase I, and fibrillarin, three proteins involved in synthesis and processing of rRNA. Transcriptional activity of RNA polymerase I wa...

  18. Regulatory T Cells in Human Ovarian Cancer

    Directory of Open Access Journals (Sweden)

    Dong-Jun Peng

    2012-01-01

    Full Text Available Multiple layers of suppressive components including regulatory T (TReg cells, suppressive antigen-presenting cells, and inhibitory cytokines form suppressive networks in the ovarian cancer microenvironment. It has been demonstrated that as a major suppressive element, TReg cells infiltrate tumor, interact with several types of immune cells, and mediate immune suppression through different molecular and cellular mechanisms. In this paper, we focus on human ovarian cancer and will discuss the nature of TReg cells including their subsets, trafficking, expansion, and function. We will briefly review the development of manipulation of TReg cells in preclinical and clinical settings.

  19. Triiodothyronine regulates cell growth and survival in renal cell cancer.

    Science.gov (United States)

    Czarnecka, Anna M; Matak, Damian; Szymanski, Lukasz; Czarnecka, Karolina H; Lewicki, Slawomir; Zdanowski, Robert; Brzezianska-Lasota, Ewa; Szczylik, Cezary

    2016-10-01

    Triiodothyronine plays an important role in the regulation of kidney cell growth, differentiation and metabolism. Patients with renal cell cancer who develop hypothyreosis during tyrosine kinase inhibitor (TKI) treatment have statistically longer survival. In this study, we developed cell based model of triiodothyronine (T3) analysis in RCC and we show the different effects of T3 on renal cell cancer (RCC) cell growth response and expression of the thyroid hormone receptor in human renal cell cancer cell lines from primary and metastatic tumors along with human kidney cancer stem cells. Wild-type thyroid hormone receptor is ubiquitously expressed in human renal cancer cell lines, but normalized against healthy renal proximal tube cell expression its level is upregulated in Caki-2, RCC6, SKRC-42, SKRC-45 cell lines. On the contrary the mRNA level in the 769-P, ACHN, HKCSC, and HEK293 cells is significantly decreased. The TRβ protein was abundant in the cytoplasm of the 786-O, Caki-2, RCC6, and SKRC-45 cells and in the nucleus of SKRC-42, ACHN, 769-P and cancer stem cells. T3 has promoting effect on the cell proliferation of HKCSC, Caki-2, ASE, ACHN, SK-RC-42, SMKT-R2, Caki-1, 786-0, and SK-RC-45 cells. Tyrosine kinase inhibitor, sunitinib, directly inhibits proliferation of RCC cells, while thyroid hormone receptor antagonist 1-850 (CAS 251310‑57-3) has less significant inhibitory impact. T3 stimulation does not abrogate inhibitory effect of sunitinib. Renal cancer tumor cells hypostimulated with T3 may be more responsive to tyrosine kinase inhibition. Moreover, some tumors may be considered as T3-independent and present aggressive phenotype with thyroid hormone receptor activated independently from the ligand. On the contrary proliferation induced by deregulated VHL and or c-Met pathways may transgress normal T3 mediated regulation of the cell cycle.

  20. Markers of murine embryonic and neural stem cells, neurons and astrocytes: reference points for developmental neurotoxicity testing

    Science.gov (United States)

    Developmental neurotoxicity (DNT) is a significant concern for environmental chemicals, as well as for food and drug constituents. The sensitivity of animal-based DNT models is unclear, and they are expensive and time consuming. Murine embryonic stem cells (mESC) recapitulate sev...

  1. Simvastatin suppresses breast cancer cell proliferation induced by senescent cells

    NARCIS (Netherlands)

    Liu, Su; Uppal, Harpreet; Demaria, Marco; Desprez, Pierre-Yves; Campisi, Judith; Kapahi, Pankaj

    2015-01-01

    Cellular senescence suppresses cancer by preventing the proliferation of damaged cells, but senescent cells can also promote cancer though the pro-inflammatory senescence-associated secretory phenotype (SASP). Simvastatin, an HMG-coA reductase inhibitor, is known to attenuate inflammation and preven

  2. Tyrosine kinase inhibitors target cancer stem cells in renal cell cancer.

    Science.gov (United States)

    Czarnecka, Anna M; Solarek, Wojciech; Kornakiewicz, Anna; Szczylik, Cezary

    2016-03-01

    This study was designed to analyze the impact of multi-targeted tyrosine kinase inhibitors on the cancer stem cell subpopulation in renal cell cancer. The second objective was to evaluate the effect of tumor growth inhibition related to a tumor niche factor - oxygen deprivation - as hypoxia develops along with the anti-angiogenic activity of tyrosine kinase inhibitors in renal tumors. Cells were treated with tyrosine kinase inhibitors, sunitinib, sorafenib and axitinib, in 2D and 3D culture conditions. Cell proliferation along with drug toxicity were evaluated. It was shown that the proliferation rate of cancer stem cells was decreased by the tyrosine kinase inhibitors. The efficacy of the growth inhibition was limited by hypoxic conditions and 3D intratumoral cell-cell interactions. We conclude that understanding the complex molecular interaction feedback loops between differentiated cancer cells, cancer stem cells and the tumor microenvironment in 3D culture should aid the identification of novel treatment targets and to evalute the efficacy of renal cancer therapies. Cell-cell interaction may represent a critical microenvironmental factor regulating cancer stem cell self-renewal potential, enhancing the stem cell phenotype and limiting drug toxicity. At the same time the role of hypoxia in renal cancer stem cell biology is also significant.

  3. Simultaneous neuron- and astrocyte-specific fluorescent marking.

    Science.gov (United States)

    Schulze, Wiebke; Hayata-Takano, Atsuko; Kamo, Toshihiko; Nakazawa, Takanobu; Nagayasu, Kazuki; Kasai, Atsushi; Seiriki, Kaoru; Shintani, Norihito; Ago, Yukio; Farfan, Camille; Hashimoto, Ryota; Baba, Akemichi; Hashimoto, Hitoshi

    2015-03-27

    Systematic and simultaneous analysis of multiple cell types in the brain is becoming important, but such tools have not yet been adequately developed. Here, we aimed to generate a method for the specific fluorescent labeling of neurons and astrocytes, two major cell types in the brain, and we have developed lentiviral vectors to express the red fluorescent protein tdTomato in neurons and the enhanced green fluorescent protein (EGFP) in astrocytes. Importantly, both fluorescent proteins are fused to histone 2B protein (H2B) to confer nuclear localization to distinguish between single cells. We also constructed several expression constructs, including a tandem alignment of the neuron- and astrocyte-expression cassettes for simultaneous labeling. Introducing these vectors and constructs in vitro and in vivo resulted in cell type-specific and nuclear-localized fluorescence signals enabling easy detection and distinguishability of neurons and astrocytes. This tool is expected to be utilized for the simultaneous analysis of changes in neurons and astrocytes in healthy and diseased brains.

  4. Stem cell concepts renew cancer research.

    Science.gov (United States)

    Dick, John E

    2008-12-15

    Although uncontrolled proliferation is a distinguishing property of a tumor as a whole, the individual cells that make up the tumor exhibit considerable variation in many properties, including morphology, proliferation kinetics, and the ability to initiate tumor growth in transplant assays. Understanding the molecular and cellular basis of this heterogeneity has important implications in the design of therapeutic strategies. The mechanistic basis of tumor heterogeneity has been uncertain; however, there is now strong evidence that cancer is a cellular hierarchy with cancer stem cells at the apex. This review provides a historical overview of the influence of hematology on the development of stem cell concepts and their linkage to cancer.

  5. Updates in colorectal cancer stem cell research

    Directory of Open Access Journals (Sweden)

    Chun-Jie Li

    2014-01-01

    Full Text Available Colorectal cancer (CRC is one of the world most common malignant tumors, also is the main disease, which cause tumor-associated death. Surgery and chemotherapy are the most used treatment of CRC. Recent research reported that, cancer stem cells (CSCs are considered as the origin of tumor genesis, development, metastasis and recurrence in theory. At present, it has been proved that, CSCs existed in many tumors including CRC. In this review, we summary the identification of CSCs according to the cell surface markers, and the development of drugs that target colorectal cancer stem cells.

  6. Prostate cancer and metastasis initiating stem cells

    Institute of Scientific and Technical Information of China (English)

    Kathleen Kelly; Juan Juan Yin

    2008-01-01

    Androgen refractory prostate cancer metastasis is a major clinical challenge.Mechanism-based approaches to treating prostate cancer metastasis require an understanding of the developmental origin of the metastasis-initiating cell.Properties of prostate cancer metastases such as plasticity with respect to differentiated phenotype and androgen independence are consistent with the transformation of a prostate epithelial progenitor or stem cell leading to metastasis.This review focuses upon current evidence and concepts addressing the identification and properties of normal prostate stem or progenitor cells and their transformed counterparts.

  7. Influence of rat substrain and growth conditions on the characteristics of primary cultures of adult rat spinal cord astrocytes.

    Science.gov (United States)

    Codeluppi, Simone; Gregory, Ebba Norsted; Kjell, Jacob; Wigerblad, Gustaf; Olson, Lars; Svensson, Camilla I

    2011-04-15

    Primary astrocyte cell cultures have become a valuable tool for studies of signaling pathways that regulate astrocyte physiology, reactivity, and function; however, differences in culture preparation affect data reproducibility. The aim of this work was to define optimal conditions for obtaining primary astrocytes from adult rat spinal cord with an expression profile most similar to adult human spinal cord astrocytes. Hence, we examined whether different Sprague-Dawley substrains and culture conditions affect astrocyte culture quality. Medium supplemented with fetal bovine serum from three sources (Sigma, Gibco, Hyclone) or a medium with defined composition (AM medium) was used to culture astrocytes isolated from spinal cords of adult Harlan and Charles River Spraque-Dawley rats. Purity was significantly different between cultures established in media with different sera. No microglia were detected in AM or Hyclone cultures. Gene expression was also affected, with AM cultures expressing the highest level of glutamine synthetase, connexin-43, and glutamate transporter-1. Interestingly, cell response to starvation was substrain dependent. Charles River-derived cultures responded the least, while astrocytes derived from Harlan rats showed a greater decrease in Gfap and glutamine synthetase, suggesting a more quiescent phenotype. Human and Harlan astrocytes cultured in AM media responded similarly to starvation. Taken together, this study shows that rat substrain and growth medium composition affect purity, expression profile and response to starvation of primary astrocytes suggesting that cultures of Harlan rats in AM media have optimal astrocyte characteristics, purity, and similarity to human astrocytes.

  8. Risk factors for astrocytic glioma and primitive neuroectodermal tumor of the brain in young children: a report from the Children's Cancer Group.

    Science.gov (United States)

    Bunin, G R; Buckley, J D; Boesel, C P; Rorke, L B; Meadows, A T

    1994-01-01

    We conducted a matched case-control study to investigate risk factors for the two most common types of brain tumors in children, astrocytic glioma and primitive neuroectodermal tumor (PNET). Since the study focused on gestational exposures, we restricted it to young children because these exposures would be expected to act early in life. Parents of 155 astrocytic glioma cases, 166 PNET cases, and controls identified by random digit dialing completed telephone interviews. Few associations occurred with the hypothesized risk factors, which were gestational exposure to alcohol, hair coloring products, farms, and substances containing N-nitroso compounds (passive smoking, makeup, incense, new cars, pacifiers, baby bottles, beer). Of the products studied that contain N-nitroso compounds, only beer was associated with a significantly increased risk of either tumor type [odds ratio (OR) for PNET = 4.0; 95% confidence interval (CI), 1.1-22.1; P = 0.04]. Elevated ORs for PNET were observed for farm residence of the mother during the pregnancy (OR = 3.7; 95% CI, 0.8-23.9; P = 0.06) and of the child for at least a year (OR = 5.0; 95% CI, 1.1-46.8; P = 0.04). Significant associations with astrocytoma were observed for mother's use of kerosene (OR = 8.9; 95% CI, 1.1-71.1; P = 0.04) and birth by Caesarean section (OR = 1.8; 95% CI, 1.1-3.2; P = 0.03). History of miscarriage was associated with a lower risk of PNET (OR = 0.5; 95% CI, 0.3-0.9; P = 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

  9. Metformin induces apoptosis of pancreatic cancer cells

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    AIM: To assess the role and mechanism of mefformin in inducing apoptosis of pancreatic cancer cells. METHODS: The human pancreatic cancer cell lines ASPC-1, BxPc-3, PANC-1 and SW1990 were exposed to mefformin. The inhibition of cell proliferation and colony formation via apoptosis induction and S phase arrest in pancreatic cancer cell lines of mefformin was tested.RESULTS: In each pancreatic cancer cell line tested, metformin inhibited cell proliferation in a dose dependent manner in MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assays). Flow cytometric analysis showed that metformin reduced the number of cells in G1 and increased the percentage of cells in S phase as well as the apoptotic fraction. Enzymelinked immunosorbent assay (EUSA) showed that metformin induced apaptosis in all pancreatic cancer cell lines. In Western blot studies, metformin induced oly-ADP-ribose polymerase(PARP) cleavage (an indicator of aspase activation) in all pancreatic cancer cell lines. The general caspase inhibitor (VAD-fmk) completely abolished metformin-induced PARP cleavage and apoptosis in ASPC-1 BxPc-3 and PANC-1, the caspase-8 specific inhibitor (IETD-fmk) and the caspase-9 specific inhibitor (LEHD-fmk) only partially abrogated metformin-induced apoptosis and PARP cleavage in BxPc-3 and PANC-1 cells. We also observed that metformin treatment ramatically reduced epidermal growth factor receptor (EGFR) and phosphorylated mitogen activated protein kinase (P-MAPK) in both a time- and dose-dependent manner in all cell lines tested.CONCLUSION: Metformin significantly inhibits cell proliferation and apoptosis in all pancreatic cell lines. And the metformin-induced apoptosis is associated with PARP leavage, activation of caspase-3, -8, and -9 in a time- and dose-dependent manner. Hence, both caspase-8 and -9-initiated apoptotic signaling pathways contribute to metforrnin-induced apoptosis in pancreatic cell lines.

  10. Effect of type-2 astrocytes on the viability of dorsal root ganglion neurons and length of neuronal processes

    Institute of Scientific and Technical Information of China (English)

    Chunling Fan; Hui Wang; Dan Chen; Xiaoxin Cheng; Kun Xiong; Xuegang Luo; Qilin Cao

    2014-01-01

    The role of type-2 astrocytes in the repair of central nervous system injury remains poorly un-derstood. In this study, using a relatively simple culture condition in vitro, type-2 astrocytes, differentiated from oligodendrocyte precursor cells by induction with bone morphogenetic pro-tein-4, were co-cultured with dorsal root ganglion neurons. We examined the effects of type-2 astrocytes differentiated from oligodendrocyte precursor cells on the survival and growth of dorsal root ganglion neurons. Results demonstrated that the number of dorsal root ganglion neurons was higher following co-culture of oligodendrocyte precursor cells and type-2 astrocytes than when cultured alone, but lower than that of neurons co-cultured with type-1 astrocytes. The length of the longest process and the length of all processes of a single neuron were shortest in neurons cultured alone, followed by neurons co-cultured with type-2 astrocytes, then neurons co-cultured with oligodendrocyte precursor cells, and longest in neurons co-cultured with type-1 astrocytes. These results indicate that co-culture with type-2 astrocytes can increase neuronal survival rate and process length. However, compared with type-1 astrocytes and oligodendrocyte precursor cells, the promotion effects of type-2 astrocytes on the growth of dorsal root ganglion neurons were weaker.

  11. Treatment Options by Stage (Small Cell Lung Cancer)

    Science.gov (United States)

    ... lung cancer is a disease in which malignant (cancer) cells form in the tissues of the lung. The ... diagnosed, tests are done to find out if cancer cells have spread within the chest or to other ...

  12. Stem Cells and Cancer; Celulas madre y cancer

    Energy Technology Data Exchange (ETDEWEB)

    Segrelles, C.; Paraminio, J. M.; Lorz, C.

    2014-04-01

    Stem cell research has thrived over the last years due to their therapeutic and regenerative potential. Scientific breakthroughs in the field are immediately translated from the scientific journals to the mass media, which is not surprising as the characterisation of the molecular mechanisms that regulate the biology of stem cells is crucial for the treatment of degenerative and cardiovascular diseases, as well as cancer. In the Molecular Oncology Unit at Ciemat we work to unravel the role of cancer stem cells in tumour development, and to find new antitumor therapies. (Author)

  13. Induction of cancer cell stemness by chemotherapy.

    Science.gov (United States)

    Hu, Xingwang; Ghisolfi, Laura; Keates, Andrew C; Zhang, Jian; Xiang, Shuanglin; Lee, Dong-ki; Li, Chiang J

    2012-07-15

    Recent studies indicate that cancer stem cells (CSCs) exist in most hematological and solid tumors. CSCs are characterized by their ability to self-renew and their capacity to differentiate into the multitude of cells that comprise the tumor mass. Moreover, these cells have been shown to be intrinsically resistant to conventional anticancer therapies. Despite their fundamental role in cancer pathogenesis, the cellular origin of CSCs remains highly controversial. The aim of this study was to examine whether heterogeneous cancer cells can acquire stem cell-like properties in response to chemotherapy. We demonstrate that carboplatin can induce the self-renewal (spherogenesis) and pluripotency (Sox2 and Oct3/4 expression) of hepatocellular carcinoma (HCC) cells grown under stem cell culture conditions. Moreover, we show that non-CSC cells, obtained by side population flow cytometric sorting using Hoechst 33342, can acquire stem-like properties after exposure to carboplatin. Finally, we show that knockdown of Sox2 and Oct3/4 gene expression in HCC cells can reduce carboplatin-mediated increases in sphere formation and increase cellular sensitivity to chemotherapy. Taken together, our data indicate that bulk cancer cells may be an important source of CSCs during tumor development, and that targeting Sox2 and/or Oct3/4 may be a promising approach for targeting CSCs in clinical cancer treatment.

  14. Cell Polarity Proteins in Breast Cancer Progression.

    Science.gov (United States)

    Rejon, Carlis; Al-Masri, Maia; McCaffrey, Luke

    2016-10-01

    Breast cancer, one of the leading causes of cancer related death in women worldwide, is a heterogeneous disease with diverse subtypes that have different properties and prognoses. The developing mammary gland is a highly proliferative and invasive tissue, and some of the developmental programs may be aberrantly activated to promote breast cancer progression. In the breast, luminal epithelial cells exhibit apical-basal polarity, and the failure to maintain this organizational structure, due to disruption of polarity complexes, is implicated in promoting hyperplasia and tumors. Therefore, understanding the mechanisms underlying loss of polarity will contribute to our knowledge of the early stages leading to the pathogenesis of the disease. In this review, we will discuss recent findings that support the idea that loss of apical-basal cell polarity is a crucial step in the acquisition of the malignant phenotype. Oncogene induced loss of tissue organization shares a conserved cellular mechanism with developmental process, we will further describe the role of the individual polarity complexes, the Par, Crumbs, and Scribble, to couple cell division orientation and cell growth. We will examine symmetric or asymmetric cell divisions in mammary stem cell and their contribution to the development of breast cancer subtypes and cancer stem cells. Finally, we will highlight some of the recent advances in our understanding of the molecular mechanisms by which changes in epithelial polarity programs promote invasion and metastasis through single cell and collective cell modes. J. Cell. Biochem. 117: 2215-2223, 2016. © 2016 Wiley Periodicals, Inc.

  15. Redox state alteration modulates astrocyte glucuronidation.

    Science.gov (United States)

    Heurtaux, T; Benani, A; Bianchi, A; Moindrot, A; Gradinaru, D; Magdalou, J; Netter, P; Minn, A

    2004-10-01

    We have investigated the effects of mild oxidative conditions on drug-metabolizing enzyme activity in rat cultured astrocytes. These experimental conditions promoting an oxidative environment were obtained by short exposure to a low concentration of menadione (5 microM) for a short duration (15 min). This resulted in the rapid and transient production of reactive oxygen species (+130%), associated with a decrease in GSH cellular content (-24%), and an increase in total protein oxidation (+26%), but promoted neither PGE(2) nor NO production. This treatment induced a rapid and persistent decrease in astrocyte glucuronidation activities, which was totally prevented by N-acetyl-l-cysteine. These oxidative conditions also affected the specific UGT1A6 activity measured in transfected V79-1A6 cells. Finally, the subsequent recovery of astrocyte glucuronidation activity may result from upregulation of UGT1A6 expression (+62%) as shown by RT-PCR and gene reporter assay. These results show that the catalytic properties and expression of cerebral UGT1A6 are highly sensitive to the redox environment. The protective effect of N-acetyl-l-cysteine suggests both a direct action of reactive oxygen species on the protein and a more delayed action on the transcriptional regulation of UGT1A6. These results suggest that cerebral metabolism can be altered by physiological or pathological redox modifications.

  16. Pituitary Adenylate cyclase-activating polypeptide orchestrates neuronal regulation of the astrocytic glutamate-releasing mechanism system xc (.).

    Science.gov (United States)

    Kong, Linghai; Albano, Rebecca; Madayag, Aric; Raddatz, Nicholas; Mantsch, John R; Choi, SuJean; Lobner, Doug; Baker, David A

    2016-05-01

    Glutamate signaling is achieved by an elaborate network involving neurons and astrocytes. Hence, it is critical to better understand how neurons and astrocytes interact to coordinate the cellular regulation of glutamate signaling. In these studies, we used rat cortical cell cultures to examine whether neurons or releasable neuronal factors were capable of regulating system xc (-) (Sxc), a glutamate-releasing mechanism that is expressed primarily by astrocytes and has been shown to regulate synaptic transmission. We found that astrocytes cultured with neurons or exposed to neuronal-conditioned media displayed significantly higher levels of Sxc activity. Next, we demonstrated that the pituitary adenylate cyclase-activating polypeptide (PACAP) may be a neuronal factor capable of regulating astrocytes. In support, we found that PACAP expression was restricted to neurons, and that PACAP receptors were expressed in astrocytes. Interestingly, blockade of PACAP receptors in cultures comprised of astrocytes and neurons significantly decreased Sxc activity to the level observed in purified astrocytes, whereas application of PACAP to purified astrocytes increased Sxc activity to the level observed in cultures comprised of neurons and astrocytes. Collectively, these data reveal that neurons coordinate the actions of glutamate-related mechanisms expressed by astrocytes, such as Sxc, a process that likely involves PACAP. A critical gap in modeling excitatory signaling is how distinct components of the glutamate system expressed by neurons and astrocytes are coordinated. In these studies, we found that system xc (-) (Sxc), a glutamate release mechanism expressed by astrocytes, is regulated by releasable neuronal factors including PACAP. This represents a novel form of neuron-astrocyte communication, and highlights the possibility that pathological changes involving astrocytic Sxc may stem from altered neuronal activity.

  17. Reactive astrocytes express NADPH diaphorase in vivo after transient ischemia.

    Science.gov (United States)

    Endoh, M; Maiese, K; Pulsinelli, W A; Wagner, J A

    1993-05-14

    In the hippocampus, ten minutes of transient global ischemia results in the death of CA1 pyramidal cells after a period of one to three days. The neurons in the CA1 region constitutively express NADPH-D (NADPH diaphorase activity). In contrast, astrocytes in the hippocampus do not normally express NADPH-D; but a population of reactive astrocytes (GFAP+ cells) begin to express of NADPH-D one day after transient global ischemia. NADPH-D is thought to be a histological marker for Nitric Oxide Synthase (NOS), the enzyme that is responsible for the synthesis of NO, a potent neurotoxin. We suggest that this increase in NADPH-D/NOS expression is an important element in the sequence of changes that occurs after ischemia, and that NO derived from reactive astrocytes or from neurons may play a causal role in neural cell death after ischemia in the hippocampus.

  18. Medium-chain fatty acids inhibit mitochondrial metabolism in astrocytes promoting astrocyte-neuron lactate and ketone body shuttle systems.

    Science.gov (United States)

    Thevenet, Jonathan; De Marchi, Umberto; Domingo, Jaime Santo; Christinat, Nicolas; Bultot, Laurent; Lefebvre, Gregory; Sakamoto, Kei; Descombes, Patrick; Masoodi, Mojgan; Wiederkehr, Andreas

    2016-05-01

    Medium-chain triglycerides have been used as part of a ketogenic diet effective in reducing epileptic episodes. The health benefits of the derived medium-chain fatty acids (MCFAs) are thought to result from the stimulation of liver ketogenesis providing fuel for the brain. We tested whether MCFAs have direct effects on energy metabolism in induced pluripotent stem cell-derived human astrocytes and neurons. Using single-cell imaging, we observed an acute pronounced reduction of the mitochondrial electrical potential and a concomitant drop of the NAD(P)H signal in astrocytes, but not in neurons. Despite the observed effects on mitochondrial function, MCFAs did not lower intracellular ATP levels or activate the energy sensor AMP-activated protein kinase. ATP concentrations in astrocytes were unaltered, even when blocking the respiratory chain, suggesting compensation through accelerated glycolysis. The MCFA decanoic acid (300 μM) promoted glycolysis and augmented lactate formation by 49.6%. The shorter fatty acid octanoic acid (300 μM) did not affect glycolysis but increased the rates of astrocyte ketogenesis 2.17-fold compared with that of control cells. MCFAs may have brain health benefits through the modulation of astrocyte metabolism leading to activation of shuttle systems that provide fuel to neighboring neurons in the form of lactate and ketone bodies.-Thevenet, J., De Marchi, U., Santo Domingo, J., Christinat, N., Bultot, L., Lefebvre, G., Sakamoto, K., Descombes, P., Masoodi, M., Wiederkehr, A. Medium-chain fatty acids inhibit mitochondrial metabolism in astrocytes promoting astrocyte-neuron lactate and ketone body shuttle systems.

  19. Channel-Mediated Lactate Release by K+-Stimulated Astrocytes

    KAUST Repository

    Sotelo-Hitschfeld, T.

    2015-03-11

    Excitatory synaptic transmission is accompanied by a local surge in interstitial lactate that occurs despite adequate oxygen availability, a puzzling phenomenon termed aerobic glycolysis. In addition to its role as an energy substrate, recent studies have shown that lactate modulates neuronal excitability acting through various targets, including NMDA receptors and G-protein-coupled receptors specific for lactate, but little is known about the cellular and molecular mechanisms responsible for the increase in interstitial lactate. Using a panel of genetically encoded fluorescence nanosensors for energy metabolites, we show here that mouse astrocytes in culture, in cortical slices, and in vivo maintain a steady-state reservoir of lactate. The reservoir was released to the extracellular space immediately after exposure of astrocytes to a physiological rise in extracellular K+ or cell depolarization. Cell-attached patch-clamp analysis of cultured astrocytes revealed a 37 pS lactate-permeable ion channel activated by cell depolarization. The channel was modulated by lactate itself, resulting in a positive feedback loop for lactate release. A rapid fall in intracellular lactate levels was also observed in cortical astrocytes of anesthetized mice in response to local field stimulation. The existence of an astrocytic lactate reservoir and its quick mobilization via an ion channel in response to a neuronal cue provides fresh support to lactate roles in neuronal fueling and in gliotransmission.

  20. Targetless T cells in cancer immunotherapy

    DEFF Research Database (Denmark)

    Thor Straten, Per; Garrido, Federico

    2016-01-01

    Attention has recently focused on new cancer immunotherapy protocols aiming to activate T cell mediated anti-tumor responses. To this end, administration of antibodies that target inhibitory molecules regulating T-cell cytotoxicity has achieved impressive clinical responses, as has adoptive cell ...

  1. Gene sensitizes cancer cells to chemotherapy drugs

    Science.gov (United States)

    NCI scientists have found that a gene, Schlafen-11 (SLFN11), sensitizes cells to substances known to cause irreparable damage to DNA.  As part of their study, the researchers used a repository of 60 cell types to identify predictors of cancer cell respons

  2. Drosophila astrocytes cover specific territories of the CNS neuropil and are instructed to differentiate by Prospero, a key effector of Notch.

    Science.gov (United States)

    Peco, Emilie; Davla, Sejal; Camp, Darius; Stacey, Stephanie M; Landgraf, Matthias; van Meyel, Don J

    2016-04-01

    Astrocytes are crucial in the formation, fine-tuning, function and plasticity of neural circuits in the central nervous system. However, important questions remain about the mechanisms instructing astrocyte cell fate. We have studied astrogenesis in the ventral nerve cord of Drosophila larvae, where astrocytes exhibit remarkable morphological and molecular similarities to those in mammals. We reveal the births of larval astrocytes from a multipotent glial lineage, their allocation to reproducible positions, and their deployment of ramified arbors to cover specific neuropil territories to form a stereotyped astroglial map. Finally, we unraveled a molecular pathway for astrocyte differentiation in which the Ets protein Pointed and the Notch signaling pathway are required for astrogenesis; however, only Notch is sufficient to direct non-astrocytic progenitors toward astrocytic fate. We found that Prospero is a key effector of Notch in this process. Our data identify an instructive astrogenic program that acts as a binary switch to distinguish astrocytes from other glial cells.

  3. The role of astrocytes in Multiple Sclerosis progression

    Directory of Open Access Journals (Sweden)

    Jorge eCorreale

    2015-08-01

    Full Text Available Multiple sclerosis is an inflammatory disorder causing central nervous system demyelination and axonal injury. Although its etiology remains elusive, several lines of evidence support the concept that autoimmunity plays a major role in disease pathogenesis.The course ofMS is highly variable; nevertheless, the majority of patients initially present a relapsing-remitting clinical course. After 10-15 years of disease, this pattern becomes progressive in up to 50% of untreated patients, during which time clinical symptoms slowly cause constant deterioration over a period of many years. In about 15% of MS patients however, disease progression is relentless from disease onset. Published evidence supports the concept that progressive multiple sclerosis reflects a poorly understood mechanism of insidious axonal degeneration and neuronal loss. Recently, the type of microglial cell and of astrocyte activation and proliferation observed has suggested contribution of resident central nervous system cells may play a critical role in disease progression. Astrocytes could contribute to this process through several mechanisms: a as part of the innate immune system, b as a source of cytotoxic factors, c inhibiting re-myelination and axonal regeneration by forming a glial scar, and d contributing to axonal mitochondrial dysfunction. Furthermore, regulatory mechanisms mediated by astrocytes can be affected by aging. Notably, astrocytes might also limit the detrimental effects of pro-inflammatory factors, while providing support and protection for oligodendrocytes and neurons. Because of the dichotomy observed in astrocytic effects, the design of therapeutic strategies targeting astrocytes becomes a challenging endeavor. Better knowledge of molecular and functional properties of astrocytes therefore, should promote understanding of their specific role in multiple sclerosis pathophysiology, and consequently lead to development of novel and more successful

  4. Effects of aspartame metabolites on astrocytes and neurons.

    Science.gov (United States)

    Rycerz, Karol; Jaworska-Adamu, Jadwiga Elżbieta

    2013-01-01

    Aspartame, a widespread sweetener used in many food products, is considered as a highly hazardous compound. Aspartame was discovered in 1965 and raises a lot of controversy up to date. Astrocytes are glial cells, the presence and functions of which are closely connected with the central nervous system (CNS). The aim of this article is to demonstrate the direct and indirect role of astrocytes participating in the harmful effects of aspartame metabolites on neurons. The artificial sweetener is broken down into phenylalanine (50%), aspartic acid (40%) and methanol (10%) during metabolism in the body. The excess of phenylalanine blocks the transport of important amino acids to the brain contributing to reduced levels of dopamine and serotonin. Astrocytes directly affect the transport of this amino acid and also indirectly by modulation of carriers in the endothelium. Aspartic acid at high concentrations is a toxin that causes hyperexcitability of neurons and is also a precursor of other excitatory amino acid - glutamates. Their excess in quantity and lack of astrocytic uptake induces excitotoxicity and leads to the degeneration of astrocytes and neurons. The methanol metabolites cause CNS depression, vision disorders and other symptoms leading ultimately to metabolic acidosis and coma. Astrocytes do not play a significant role in methanol poisoning due to a permanent consumption of large amounts of aspartame. Despite intense speculations about the carcinogenicity of aspartame, the latest studies show that its metabolite - diketopiperazine - is cancirogenic in the CNS. It contributes to the formation of tumors in the CNS such as gliomas, medulloblastomas and meningiomas. Glial cells are the main source of tumors, which can be caused inter alia by the sweetener in the brain. On the one hand the action of astrocytes during aspartame poisoning may be advantageous for neuro-protection while on the other it may intensify the destruction of neurons. The role of the glia in

  5. Low white blood cell count and cancer

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000675.htm Low white blood cell count and cancer To use ... high blood pressure, or seizures Continue Reading How Low is too Low? When your blood is tested, ...

  6. Noncoding RNAs in cancer and cancer stem cells

    Institute of Scientific and Technical Information of China (English)

    Tianzhi Huang; Angel Alvarez; Bo Hu; Shi-Yuan Cheng

    2013-01-01

    In recent years, it has become increasingly apparent that noncoding RNAs (ncRNA) are of crucial importance for human cancer. The functional relevance of ncRNAs is particularly evident for microRNAs (miRNAs) and long noncoding RNAs (lncRNAs). miRNAs are endogenously expressed small RNA sequences that act as post-transcriptional regulators of gene expression and have been extensively studied for their roles in cancers, whereas lncRNAs are emerging as important players in the cancer paradigm in recent years. These noncoding genes are often aberrantly expressed in a variety of human cancers. However, the biological functions of most ncRNAs remain largely unknown. Recently, evidence has begun to accumulate describing how ncRNAs are dysregulated in cancer and cancer stem cells, a subset of cancer cells harboring self-renewal and differentiation capacities. These studies provide insight into the functional roles that ncRNAs play in tumor initiation, progression, and resistance to therapies, and they suggest ncRNAs as attractive therapeutic targets and potential y useful diagnostic tools.

  7. Cancer Stem Cells in Head and Neck Cancer

    Directory of Open Access Journals (Sweden)

    Xiao-Jing Wang

    2011-01-01

    Full Text Available Head and neck cancer (HNC is the sixth most common malignancy world-wide, however the survival rate has not improved for the past 20 years. In recent years, the cancer stem cell (CSC hypothesis has gained ground in several malignancies and there is mounting evidence suggesting CSCs mediate tumor resistance to chemotherapy and radiation therapy. However, the CSC theory is also challenged at least in certain types of cancer. Here we review the progress of CSC studies in HNC, which suggest that HNC conforms to the CSC model. The identified CSC markers and their tumor initiation properties provide a framework for the development of novel therapeutic strategies for HNC.

  8. PTEN, Stem Cells, and Cancer Stem Cells*S⃞

    OpenAIRE

    Hill, Reginald; Wu, Hong

    2009-01-01

    Like normal stem cells, “cancer stem cells” have the capacity for indefinite proliferation and generation of new cancerous tissues through self-renewal and differentiation. Among the major intracellular signaling pathways, WNT, SHH, and NOTCH are known to be important in regulating normal stem cell activities, and their alterations are associated with tumorigenesis. It has become clear recently that PTEN (phosphatase and tensin homologue) is also critical for stem cell...

  9. Acute isolation and transcriptome characterization of cortical astrocytes and microglia from young and aged mice

    NARCIS (Netherlands)

    Orre, Marie; Kamphuis, W.; Osborn, Lana M; Melief, Jeroen; Kooijman, Lieneke; Huitinga, I.; Klooster, Jan; Bossers, K.; Hol, Elly M

    2014-01-01

    Astrocytes and microglia become reactive in many neurological disorders resulting in phenotypic and functional alterations. Both cell types might also display functional changes during normal aging. To identify gene signatures and changes in basal cellular functions of astrocytes and microglia in re

  10. Synapses lacking astrocyte appear in the amygdala during consolidation of Pavlovian threat conditioning.

    Science.gov (United States)

    Ostroff, Linnaea E; Manzur, Mustfa K; Cain, Christopher K; Ledoux, Joseph E

    2014-06-15

    There is growing evidence that astrocytes, long held to merely provide metabolic support in the adult brain, participate in both synaptic plasticity and learning and memory. Astrocytic processes are sometimes present at the synaptic cleft, suggesting that they might act directly at individual synapses. Associative learning induces synaptic plasticity and morphological changes at synapses in the lateral amygdala (LA). To determine whether astrocytic contacts are involved in these changes, we examined LA synapses after either threat conditioning (also called fear conditioning) or conditioned inhibition in adult rats by using serial section transmission electron microscopy (ssTEM) reconstructions. There was a transient increase in the density of synapses with no astrocytic contact after threat conditioning, especially on enlarged spines containing both polyribosomes and a spine apparatus. In contrast, synapses with astrocytic contacts were smaller after conditioned inhibition. This suggests that during memory consolidation astrocytic processes are absent if synapses are enlarging but present if they are shrinking. We measured the perimeter of each synapse and its degree of astrocyte coverage, and found that only about 20-30% of each synapse was ensheathed. The amount of synapse perimeter surrounded by astrocyte did not scale with synapse size, giving large synapses a disproportionately long astrocyte-free perimeter and resulting in a net increase in astrocyte-free perimeter after threat conditioning. Thus astrocytic processes do not mechanically isolate LA synapses, but may instead interact through local signaling, possibly via cell-surface receptors. Our results suggest that contact with astrocytic processes opposes synapse growth during memory consolidation.

  11. NT2 derived neuronal and astrocytic network signalling.

    Directory of Open Access Journals (Sweden)

    Eric J Hill

    Full Text Available A major focus of stem cell research is the generation of neurons that may then be implanted to treat neurodegenerative diseases. However, a picture is emerging where astrocytes are partners to neurons in sustaining and modulating brain function. We therefore investigated the functional properties of NT2 derived astrocytes and neurons using electrophysiological and calcium imaging approaches. NT2 neurons (NT2Ns expressed sodium dependent action potentials, as well as responses to depolarisation and the neurotransmitter glutamate. NT2Ns exhibited spontaneous and coordinated calcium elevations in clusters and in extended processes, indicating local and long distance signalling. Tetrodotoxin sensitive network activity could also be evoked by electrical stimulation. Similarly, NT2 astrocytes (NT2As exhibited morphology and functional properties consistent with this glial cell type. NT2As responded to neuronal activity and to exogenously applied neurotransmitters with calcium elevations, and in contrast to neurons, also exhibited spontaneous rhythmic calcium oscillations. NT2As also generated propagating calcium waves that were gap junction and purinergic signalling dependent. Our results show that NT2 derived astrocytes exhibit appropriate functionality and that NT2N networks interact with NT2A networks in co-culture. These findings underline the utility of such cultures to investigate human brain cell type signalling under controlled conditions. Furthermore, since stem cell derived neuron function and survival is of great importance therapeutically, our findings suggest that the presence of complementary astrocytes may be valuable in supporting stem cell derived neuronal networks. Indeed, this also supports the intriguing possibility of selective therapeutic replacement of astrocytes in diseases where these cells are either lost or lose functionality.

  12. Cancer Vaccine by Fusions of Dendritic and Cancer Cells

    OpenAIRE

    Shigeo Koido; Eiichi Hara; Sadamu Homma; Yoshihisa Namiki; Toshifumi Ohkusa; Jianlin Gong; Hisao Tajiri

    2010-01-01

    Dendritic cells (DCs) are potent antigen-presenting cells and play a central role in the initiation and regulation of primary immune responses. Therefore, their use for the active immunotherapy against cancers has been studied with considerable interest. The fusion of DCs with whole tumor cells represents in many ways an ideal approach to deliver, process, and subsequently present a broad array of tumor-associated antigens, including those yet to be unidentified, in the context of DCs-derived...

  13. Effects of cultured astrocytes from rat cerebral cortex onthe neurite development of PC12 cells%星形神经胶质细胞对PC12神经元突起生长发育的影响

    Institute of Scientific and Technical Information of China (English)

    莫永炎; 邵紫韫; 陈瑗; 周玫; 张宝

    2004-01-01

    背景:星形细胞对神经元有提供营养、支持及调节突触活性作用,但它对神经元发育的影响还尚不清楚.目的:探讨体外培养的Sprague Dawley大鼠大脑皮质星形细胞对PC12神经元突起生长发育的作用.设计:完全随机设计,对照实验研究.方法:以培养的星形细胞与PC12神经元按不同细胞数目比例(50:1~1:1)共同培养,并用其制备的条件培养液培养PG12细胞.主要观察指标:用快速灵敏的MTT'比色法测定PC12神经元的细胞活力,用光学相差显微镜观察PC12细胞形态学变化.结果:①星形细胞条件培养液可增强PG12细胞活力(MTT测定的A值由0.255±0.012提高到0.510±0.036,P<0.001),却不能促使PC12神经元突起的生出.②当将星形细胞与PC12细胞按30:1~1:1的比例共同培养时,既可提高PC12细胞折光性和光晕又可促使其突起的生长;但按50:1~40:1的比例共同培养时,只观察到提高PC12细胞折光性和光晕,而无促使其突起生长发育的作用.结论:PC12神经元细胞活力的提高与星形细胞分泌到条件培养液中的可溶性因子有关,而PC12神经元突起生长发育可能是和与星形细胞的直接接触以及二者的细胞数目比有关.%BACKGROUND: Although astrocytes are kown to provide structural andtrophic support to neurons and modulate synaptic activity, their role is farfrom being completely understood.OBJECTIVE: To investigate effects of cultured astrocytes fromSprague-Dawley rat cerebral cortex on the neurite development of PC12 cellsderived from rat pheochromocytoma.DESIGN: Completely randomized controlled trial.METHODS: PC12 cells were co-cultured with astrocyte according to dif-ferent astrocytes/neurons ratio(50: 1 -1: 1), or cultured with serum-freeconditioned medium of astrocytes (ACM).MAIN OUTCOME MEASURES: The vitality of PC12 cells was measuredby sensitive MTT method and their morphologic features were observed byOlympus light microscope.RFSULTS: When PC

  14. Neuron-glia signaling: Implications for astrocyte differentiation and synapse formation.

    Science.gov (United States)

    Stipursky, Joice; Romão, Luciana; Tortelli, Vanessa; Neto, Vivaldo Moura; Gomes, Flávia Carvalho Alcantara

    2011-10-10

    Glial cells are currently viewed as active partners of neurons in synapse formation. The close proximity of astrocytes to the synaptic cleft implicates that they strongly influence synapse function as well as suggests that these cells might be potential targets for neuronal-released molecules. In this review, we discuss the signaling pathways of astrocyte generation and the role of astrocyte-derived molecules in synapse formation in the central nervous system. Further, we discuss the role of the excitatory neurotransmitter, glutamate and transforming growth factor beta 1 (TGF-β1) pathway in astrocyte generation and differentiation. We provide evidence that astrocytes surrounding synapses are target of neuronal activity and shed light into the role of astroglial cells into neurological disorders associated with glutamate neurotoxicity.

  15. Neuroimmunological Implications of AQP4 in Astrocytes

    Science.gov (United States)

    Ikeshima-Kataoka, Hiroko

    2016-01-01

    The brain has high-order functions and is composed of several kinds of cells, such as neurons and glial cells. It is becoming clear that many kinds of neurodegenerative diseases are more-or-less influenced by astrocytes, which are a type of glial cell. Aquaporin-4 (AQP4), a membrane-bound protein that regulates water permeability is a member of the aquaporin family of water channel proteins that is expressed in the endfeet of astrocytes in the central nervous system (CNS). Recently, AQP4 has been shown to function, not only as a water channel protein, but also as an adhesion molecule that is involved in cell migration and neuroexcitation, synaptic plasticity, and learning/memory through mechanisms involved in long-term potentiation or long-term depression. The most extensively examined role of AQP4 is its ability to act as a neuroimmunological inducer. Previously, we showed that AQP4 plays an important role in neuroimmunological functions in injured mouse brain in concert with the proinflammatory inducer osteopontin (OPN). The aim of this review is to summarize the functional implication of AQP4, focusing especially on its neuroimmunological roles. This review is a good opportunity to compile recent knowledge and could contribute to the therapeutic treatment of autoimmune diseases through strategies targeting AQP4. Finally, the author would like to hypothesize on AQP4’s role in interaction between reactive astrocytes and reactive microglial cells, which might occur in neurodegenerative diseases. Furthermore, a therapeutic strategy for AQP4-related neurodegenerative diseases is proposed. PMID:27517922

  16. Multiple myeloma cancer stem cells

    Science.gov (United States)

    Gao, Minjie; Kong, Yuanyuan; Yang, Guang; Gao, Lu; Shi, Jumei

    2016-01-01

    Multiple myeloma (MM) remains incurable despite much progress that has been made in the treatment of the disease. MM cancer stem cell (MMSC), a rare subpopulation of MM cells with the capacity for self-renewal and drug resistance, is considered to lead to disease relapse. Several markers such as side population (SP) and ALDH1+ have been used to identify MMSCs. However, ideally and more precisely, the identification of the MMSCs should rely on MMSCs phenotype. Unfortunately the MMSC phenotype has not been properly defined yet. Drug resistance is the most important property of MMSCs and contributes to disease relapse, but the mechanisms of drug resistance have not been fully understood. The major signaling pathways involved in the regulation of self-renewal and differentiation of MMSCs include Hedgehog (Hh), Wingless (Wnt), Notch and PI3K/Akt/mTOR. However, the precise role of these signaling pathways needs to be clarified. It has been reported that the microRNA profile of MMSCs is remarkably different than that of non-MMSCs. Therefore, the search for targeting MMSCs has also been focused on microRNAs. Complex and mutual interactions between the MMSC and the surrounding bone marrow (BM) microenvironment sustain self-renewal and survival of MMSC. However, the required molecules for the interaction of the MMSC and the surrounding BM microenvironment need to be further identified. In this review, we summarize the current state of knowledge of MMSCs regarding their phenotype, mechanisms of drug resistance, signaling pathways that regulate MMSCs self-renewal and differentiation, abnormal microRNAs expression, and their interactions with the BM microenvironment. PMID:27007154

  17. Morphine Protects Spinal Cord Astrocytes from Glutamate-Induced Apoptosis via Reducing Endoplasmic Reticulum Stress

    Directory of Open Access Journals (Sweden)

    Chao Zhang

    2016-10-01

    Full Text Available Glutamate is not only a neurotransmitter but also an important neurotoxin in central nervous system (CNS. Chronic elevation of glutamate induces both neuronal and glial cell apoptosis. However, its effect on astrocytes is complex and still remains unclear. In this study, we investigated whether morphine, a common opioid ligand, could affect glutamate-induced apoptosis in astrocytes. Primary cultured astrocytes were incubated with glutamate in the presence/absence of morphine. It was found that morphine could reduce glutamate-induced apoptosis of astrocytes. Furthermore, glutamate activated Ca2+ release, thereby inducing endoplasmic reticulum (ER stress in astrocytes, while morphine attenuated this deleterious effect. Using siRNA to reduce the expression of κ-opioid receptor, morphine could not effectively inhibit glutamate-stimulated Ca2+ release in astrocytes, the protective effect of morphine on glutamate-injured astrocytes was also suppressed. These results suggested that morphine could protect astrocytes from glutamate-induced apoptosis via reducing Ca2+ overload and ER stress pathways. In conclusion, this study indicated that excitotoxicity participated in the glutamate mediated apoptosis in astrocytes, while morphine attenuated this deleterious effect via regulating Ca2+ release and ER stress.

  18. Trophic and tropic effects of striatal astrocytes on cografted mesencephalic dopamine neurons and their axons.

    Science.gov (United States)

    Pierret, P; Quenneville, N; Vandaele, S; Abbaszadeh, R; Lanctôt, C; Crine, P; Doucet, G

    1998-01-01

    Astrocytes from the ventral mesencephalon and from the striatum respectively promote the dendritic and axonal arborization of dopamine (DA) neurons in vitro. To test this response in vivo, astrocytes in primary cultures from the neonatal cerebral cortex, ventral mesencephalon, or striatum were coimplanted with fetal ventral mesencephalic tissue into the intact or DA-denervated striatum of adult rats and these cografts examined after 3-6 months by tyrosine hydroxylase (TH) immunohistochemistry (intact recipients) or after 5-6 months by in vitro [3H]DA-uptake autoradiography (DA-denervated recipients). In contrast with single ventral mesencephalic grafts, all types of cograft displayed a rather uniform distribution of TH-immunoreactive perikarya. The average size of TH-immunoreactive cell bodies was not significantly different in cografts containing cortical or mesencephalic astrocytes and in single ventral mesencephalic grafts, but it was significantly larger in cografts containing striatal astrocytes. Nevertheless, the number of [3H]DA-labeled terminals in the DA-lesioned host striatum was clearly smaller with cografts of striatal astrocytes than with single mesencephalic grafts or with cografts containing cortical astrocytes. On the other hand, cografts of striatal astrocytes contained much higher numbers of [3H]DA-labeled terminals than the other types of graft or cograft. Thus, while cografted astrocytes in general influence the distribution of DA neurons within the graft, astrocytes from the neonatal striatum have a trophic effect on DA perikarya and a tropic effect on DA axons, keeping the latter within the graft.

  19. Interlukin-18 Is a Pivot Regulatory Factor on Matrix Metalloproteinase-13 Expression and Brain Astrocytic Migration.

    Science.gov (United States)

    Chen, Jia-Hong; Tsai, Chon-Haw; Lin, Hsiao-Yun; Huang, Chien-Fang; Leung, Yuk-Man; Lai, Sheng-Wei; Tsai, Cheng-Fang; Chang, Pei-Chun; Lu, Dah-Yuu; Lin, Chingju

    2016-11-01

    The expression of matrix metalloproteinase-13 (MMP-13) has been shown to be elevated in some pathophysiological conditions and is involved in the degradation of extracellular matrix in astrocytes. In current study, the function of MMP-13 was further investigated. The conditioned medium (CM) collected from activated microglia increased interleukin (IL)-18 production and enhanced MMP-13 expression in astrocytes. Furthermore, treatment with recombinant IL-18 increased MMP-13 protein and mRNA levels in astrocytes. Recombinant IL-18 stimulation also increased the enzymatic activity of MMP-13 and the migratory activity of astrocytes, while administration of MMP-13 or pan-MMP inhibitors antagonized IL-18-induced migratory activity of astrocytes. In addition, administration of recombinant IL-18 to astrocytes led to the phosphorylation of JNK, Akt, or PKCδ, and treatment of astrocytes with JNK, PI3 kinase/Akt, or PKCδ inhibitors significantly decreased the IL-18-induced migratory activity. Taken together, the results suggest that IL-18-induced MMP-13 expression in astrocytes is regulated by JNK, PI3 kinase/Akt, and PKCδ signaling pathways. These findings also indicate that IL-18 is an important regulator leading to MMP-13 expression and cell migration in astrocytes.

  20. Cell of Origin and Cancer Stem Cell Phenotype in Medulloblastomas

    Science.gov (United States)

    2015-07-01

    progenitor cells (NPCs) by expressing an activated form of Notch1 (N1ICD) or oncogenic PIK3CA (PIK3CA*) in the developing mouse cerebellum, using cell...resistance, pediatric cancer, brain tumor, Notch1, PIK3CA, cell of origin, molecular subtypes, neural stem cells, neural progenitor cells, tumor initiation...neural progenitor cells, tumor initiation. 3. ACCOMPLISHMENTS: Major goals of the project: The stated goals of this project are to: 1) test the

  1. Intercellular synchronization of diffusively coupled astrocytes

    CERN Document Server

    Alam, Md Jahoor; Devi, Gurumayum Reenaroy; Singh, Heisnam Dinachandra; Singh, R K Brojen; Sharma, B Indrajit

    2010-01-01

    We examine the synchrony of the dynamics of localized [Ca^{2+}]_i oscillations in internal pool of astrocytes via diffusing coupling of a network of such cells in a certain topology where cytosolic Ca^{2+} and inositol 1,4,5-triphosphate (IP3) are coupling molecules; and possible long range interaction among the cells. Our numerical results claim that the cells exhibit fairly well coordinated behaviour through this coupling mechanism. It is also seen in the results that as the number of coupling molecular species is increased, the rate of synchrony is also increased correspondingly. Apart from the topology of the cells taken, as the number of coupled cells around any one of the cells in the system is increased, the cell process information faster.

  2. The analgesic effect on neuropathic pain of retrogradely transported botulinum neurotoxin A involves Schwann cells and astrocytes.

    Directory of Open Access Journals (Sweden)

    Sara Marinelli

    Full Text Available In recent years a growing debate is about whether botulinum neurotoxins are retrogradely transported from the site of injection. Immunodetection of cleaved SNAP-25 (cl-SNAP-25, the protein of the SNARE complex targeted by botulinum neurotoxin serotype A (BoNT/A, could represent an excellent approach to investigate the mechanism of action on the nociceptive pathways at peripheral and/or central level. After peripheral administration of BoNT/A, we analyzed the expression of cl-SNAP-25, from the hindpaw's nerve endings to the spinal cord, together with the behavioral effects on neuropathic pain. We used the chronic constriction injury of the sciatic nerve in CD1 mice as animal model of neuropathic pain. We evaluated immunostaining of cl-SNAP-25 in the peripheral nerve endings, along the sciatic nerve, in dorsal root ganglia and in spinal dorsal horns after intraplantar injection of saline or BoNT/A, alone or colocalized with either glial fibrillar acidic protein, GFAP, or complement receptor 3/cluster of differentiation 11b, CD11b, or neuronal nuclei, NeuN, depending on the area investigated. Immunofluorescence analysis shows the presence of the cl-SNAP-25 in all tissues examined, from the peripheral endings to the spinal cord, suggesting a retrograde transport of BoNT/A. Moreover, we performed in vitro experiments to ascertain if BoNT/A was able to interact with the proliferative state of Schwann cells (SC. We found that BoNT/A modulates the proliferation of SC and inhibits the acetylcholine release from SC, evidencing a new biological effect of the toxin and further supporting the retrograde transport of the toxin along the nerve and its ability to influence regenerative processes. The present results strongly sustain a combinatorial action at peripheral and central neural levels and encourage the use of BoNT/A for the pathological pain conditions difficult to treat in clinical practice and dramatically impairing patients' quality of life.

  3. The Analgesic Effect on Neuropathic Pain of Retrogradely Transported botulinum Neurotoxin A Involves Schwann Cells and Astrocytes

    Science.gov (United States)

    Ricordy, Ruggero; Uggenti, Carolina; Tata, Ada Maria; Luvisetto, Siro; Pavone, Flaminia

    2012-01-01

    In recent years a growing debate is about whether botulinum neurotoxins are retrogradely transported from the site of injection. Immunodetection of cleaved SNAP-25 (cl-SNAP-25), the protein of the SNARE complex targeted by botulinum neurotoxin serotype A (BoNT/A), could represent an excellent approach to investigate the mechanism of action on the nociceptive pathways at peripheral and/or central level. After peripheral administration of BoNT/A, we analyzed the expression of cl-SNAP-25, from the hindpaw’s nerve endings to the spinal cord, together with the behavioral effects on neuropathic pain. We used the chronic constriction injury of the sciatic nerve in CD1 mice as animal model of neuropathic pain. We evaluated immunostaining of cl-SNAP-25 in the peripheral nerve endings, along the sciatic nerve, in dorsal root ganglia and in spinal dorsal horns after intraplantar injection of saline or BoNT/A, alone or colocalized with either glial fibrillar acidic protein, GFAP, or complement receptor 3/cluster of differentiation 11b, CD11b, or neuronal nuclei, NeuN, depending on the area investigated. Immunofluorescence analysis shows the presence of the cl-SNAP-25 in all tissues examined, from the peripheral endings to the spinal cord, suggesting a retrograde transport of BoNT/A. Moreover, we performed in vitro experiments to ascertain if BoNT/A was able to interact with the proliferative state of Schwann cells (SC). We found that BoNT/A modulates the proliferation of SC and inhibits the acetylcholine release from SC, evidencing a new biological effect of the toxin and further supporting the retrograde transport of the toxin along the nerve and its ability to influence regenerative processes. The present results strongly sustain a combinatorial action at peripheral and central neural levels and encourage the use of BoNT/A for the pathological pain conditions difficult to treat in clinical practice and dramatically impairing patients’ quality of life. PMID:23110146

  4. Exercise regulates breast cancer cell viability

    DEFF Research Database (Denmark)

    Dethlefsen, Christine; Lillelund, Christian; Midtgaard, Julie

    2016-01-01

    Purpose: Exercise decreases breast cancer risk and disease recurrence, but the underlying mechanisms are unknown. Training adaptations in systemic factors have been suggested as mediating causes. We aimed to examine if systemic adaptations to training over time, or acute exercise responses......, in breast cancer survivors could regulate breast cancer cell viability in vitro. Methods: Blood samples were collected from breast cancer survivors, partaking in either a 6-month training intervention or across a 2 h acute exercise session. Changes in training parameters and systemic factors were evaluated...... and pre/post exercise-conditioned sera from both studies were used to stimulate breast cancer cell lines (MCF-7, MDA-MB-231) in vitro. Results: Six months of training increased VO2peak (16.4 %, p

  5. Cancer and deregulation of stem cells pathways

    Directory of Open Access Journals (Sweden)

    Filipe Correia Martins

    2011-12-01

    Full Text Available Stem cells may have an important etiological role in cancer. Their classic regulatory pathways are deregulated in tumors, strengthening the stem cell theory of cancer. In this manuscript, we review Wnt, Notch and Hedhehog pathways, describing which of their factors may be responsible for the neoplastic development. Furthermore, we classify these elements as oncogenes or tumor suppressor genes, demonstrating their mutation implications in cancer. The activation of these pathways is associated with the expression of certain genes which maintain proliferation and apoptosis inhibition. Further work should be carried out in the future in order to control tumor development by controlling these signaling cascades.

  6. Astrocyte Sodium Signalling and Panglial Spread of Sodium Signals in Brain White Matter.

    Science.gov (United States)

    Moshrefi-Ravasdjani, Behrouz; Hammel, Evelyn L; Kafitz, Karl W; Rose, Christine R

    2017-02-18

    In brain grey matter, excitatory synaptic transmission activates glutamate uptake into astrocytes, inducing sodium signals which propagate into neighboring astrocytes through gap junctions. These sodium signals have been suggested to serve an important role in neuro-metabolic coupling. So far, it is unknown if astrocytes in white matter-that is in brain regions devoid of synapses-are also able to undergo such intra- and intercellular sodium signalling. In the present study, we have addressed this question by performing quantitative sodium imaging in acute tissue slices of mouse corpus callosum. Focal application of glutamate induced sodium transients in SR101-positive astrocytes. These were largely unaltered in the presence of ionotropic glutamate receptors blockers, but strongly dampened upon pharmacological inhibition of glutamate uptake. Sodium signals induced in individual astrocytes readily spread into neighboring SR101-positive cells with peak amplitudes decaying monoexponentially with distance from the stimulated cell. In addition, spread of sodium was largely unaltered during pharmacological inhibition of purinergic and glutamate receptors, indicating gap junction-mediated, passive diffusion of sodium between astrocytes. Using cell-type-specific, transgenic reporter mice, we found that sodium signals also propagated, albeit less effectively, from astrocytes to neighboring oligodendrocytes and NG2 cells. Again, panglial spread was unaltered with purinergic and glutamate receptors blocked. Taken together, our results demonstrate that activation of sodium-dependent glutamate transporters induces sodium signals in white matter astrocytes, which spread within the astrocyte syncytium. In addition, we found a panglial passage of sodium signals from astrocytes to NG2 cells and oligodendrocytes, indicating functional coupling between these macroglial cells in white matter.

  7. Astrocytic modulation of neuronal excitability through K(+) spatial buffering.

    Science.gov (United States)

    Bellot-Saez, Alba; Kékesi, Orsolya; Morley, John W; Buskila, Yossi

    2017-03-06

    The human brain contains two major cell populations, neurons and glia. While neurons are electrically excitable and capable of discharging short voltage pulses known as action potentials, glial cells are not. However, astrocytes, the prevailing subtype of glia in the cortex, are highly connected and can modulate the excitability of neurons by changing the concentration of potassium ions in the extracellular environment, a process called K(+) clearance. During the past decade, astrocytes have been the focus of much research, mainly due to their close association with synapses and their modulatory impact on neuronal activity. It has been shown that astrocytes play an essential role in normal brain function including: nitrosative regulation of synaptic release in the neocortex, synaptogenesis, synaptic transmission and plasticity. Here, we discuss the role of astrocytes in network modulation through their K(+) clearance capabilities, a theory that was first raised 50 years ago by Orkand and Kuffler. We will discuss the functional alterations in astrocytic activity that leads to aberrant modulation of network oscillations and synchronous activity.

  8. Overcoming Multidrug Resistance in Cancer Stem Cells

    Directory of Open Access Journals (Sweden)

    Karobi Moitra

    2015-01-01

    Full Text Available The principle mechanism of protection of stem cells is through the expression of ATP-binding cassette (ABC transporters. These transporters serve as the guardians of the stem cell population in the body. Unfortunately these very same ABC efflux pumps afford protection to cancer stem cells in tumors, shielding them from the adverse effects of chemotherapy. A number of strategies to circumvent the function of these transporters in cancer stem cells are currently under investigation. These strategies include the development of competitive and allosteric modulators, nanoparticle mediated delivery of inhibitors, targeted transcriptional regulation of ABC transporters, miRNA mediated inhibition, and targeting of signaling pathways that modulate ABC transporters. The role of ABC transporters in cancer stem cells will be explored in this paper and strategies aimed at overcoming drug resistance caused by these particular transporters will also be discussed.

  9. Neurotrophin signaling in cancer stem cells.

    Science.gov (United States)

    Chopin, Valérie; Lagadec, Chann; Toillon, Robert-Alain; Le Bourhis, Xuefen

    2016-05-01

    Cancer stem cells (CSCs), are thought to be at the origin of tumor development and resistance to therapies. Thus, a better understanding of the molecular mechanisms involved in the control of CSC stemness is essential to the design of more effective therapies for cancer patients. Cancer cell stemness and the subsequent expansion of CSCs are regulated by micro-environmental signals including neurotrophins. Over the years, the roles of neurotrophins in tumor development have been well established and regularly reviewed. Especially, nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) are reported to stimulate tumor cell proliferation, survival, migration and/or invasion, and favors tumor angiogenesis. More recently, neurotrophins have been reported to regulate CSCs. This review briefly presents neurotrophins and their receptors, summarizes their roles in different cancers, and discusses the emerging evidence of neurotrophins-induced enrichment of CSCs as well as the involved signaling pathways.

  10. The effects of trypsin on rat brain astrocyte activation.

    Directory of Open Access Journals (Sweden)

    Masoud Fereidoni

    2013-12-01

    Full Text Available Astrocytes are cells within the central nervous system which are activated in a wide spectrum of infections, and autoimmune and neurodegenerative diseases. In pathologic states, they produce inflammatory cytokines, chemokines, and nitric oxide (NO, and sometimes they induce apoptosis. Their protease-activated receptors (PARs can be activated by proteases, e.g. thrombin and trypsin, which are important in brain inflammation. The current study aimed to investigate the effects of different concentrations of trypsin (1 to 100U/ml on cultured astrocytes.In the present study, two-day rat infants' brains were isolated and homogenized after meninges removal, then cultivated in DMEM + 10% FBS medium. 10 days later, astrocytes were harvested and recultivated for more purification (up to 95%, using Immunocytochemistry method, in order to be employed for tests. They were affected by different concentrations of trypsin (1, 5, 10, 15, 20, 40, 60, 80, and 100 U/ml. To reveal the inflammation progress, NO concentrations (the Griess test were assessed after 24 and 48 hours.The results showed that trypsin concentration up to 20 U/ml caused a significant increase in NO, in a dose-dependent manner, on cultured astrocytes (P < 0.001. Trypsin 20 U/ml increased NO production fivefold the control group (P < 0.001. At higher concentrations than 20 U/ml, NO production diminished (P < 0.001. At 100 U/ml, NO production was less than the control group (P < 0.001.Inflammatory effects of trypsin 5-20 U/ml are probably due to the stimulation of astrocytes' PAR-2 receptors and the increasing of the activation of NF-κB, PKC, MAPKs. Stimulation of astrocytes' PAR-2 receptors causes an increase in iNOS activation which in turn leads to NO production. However, higher trypsin concentration possibly made astrocyte apoptosis; therefore, NO production diminished. These assumptions need to be further investigated.

  11. Isolation of Cancer Stem Cells From Human Prostate Cancer Samples

    Science.gov (United States)

    Vidal, Samuel J.; Quinn, S. Aidan; de la Iglesia-Vicente, Janis; Bonal, Dennis M.; Rodriguez-Bravo, Veronica; Firpo-Betancourt, Adolfo; Cordon-Cardo, Carlos; Domingo-Domenech, Josep

    2014-01-01

    The cancer stem cell (CSC) model has been considerably revisited over the last two decades. During this time CSCs have been identified and directly isolated from human tissues and serially propagated in immunodeficient mice, typically through antibody labeling of subpopulations of cells and fractionation by flow cytometry. However, the unique clinical features of prostate cancer have considerably limited the study of prostate CSCs from fresh human tumor samples. We recently reported the isolation of prostate CSCs directly from human tissues by virtue of their HLA class I (HLAI)-negative phenotype. Prostate cancer cells are harvested from surgical specimens and mechanically dissociated. A cell suspension is generated and labeled with fluorescently conjugated HLAI and stromal antibodies. Subpopulations of HLAI-negative cells are finally isolated using a flow cytometer. The principal limitation of this protocol is the frequently microscopic and multifocal nature of primary cancer in prostatectomy specimens. Nonetheless, isolated live prostate CSCs are suitable for molecular characterization and functional validation by transplantation in immunodeficient mice. PMID:24686446

  12. Effect of 8-bromo-cAMP and dexamethasone on glutamate metabolism in rat astrocytes

    Energy Technology Data Exchange (ETDEWEB)

    Zielke, H.R.; Tildon, J.T.; Landry, M.E.; Max, S.R. (Univ. of Maryland School of Medicine, Baltimore (USA))

    1990-11-01

    Glutamine synthetase (GS) activity in cultured rat astrocytes was measured in extracts and compared to the intracellular rate of glutamine synthesis by intact control astrocytes or astrocytes exposed to 1 mM 8-bromo-cAMP (8Br-cAMP) + 1 microM dexamethasone (DEX) for 4 days. GS activity in extracts of astrocytes treated with 8Br-cAMP + DEX was 7.5 times greater than the activity in extracts of control astrocytes. In contrast, the intracellular rate of glutamine synthesis by intact cells increased only 2-fold, suggesting that additional intracellular effectors regulate the expression of GS activity inside the intact cell. The rate of glutamine synthesis by astrocytes was 4.3 times greater in MEM than in HEPES buffered Hank's salts. Synthesis of glutamine by intact astrocytes cultured in MEM was independent of the external glutamine or ammonia concentrations but was increased by higher extracellular glutamate concentrations. In studies with intact astrocytes 80% of the original (U-{sup 14}C)glutamate was recovered in the medium as radioactive glutamine, 2-3% as aspartate, and 7% as glutamate after 2 hours for both control and treated astrocytes. The results suggest: (1) astrocytes are highly efficient in the conversion of glutamate to glutamine; (2) induction of GS activity increases the rate of glutamate conversion to glutamine by astrocytes and the rate of glutamine release into the medium; (3) endogenous intracellular regulators of GS activity control the flux of glutamate through this enzymatic reaction; and (4) the composition of the medium alters the rate of glutamine synthesis from external glutamate.

  13. Embryonic stem cell factors and pancreatic cancer.

    Science.gov (United States)

    Herreros-Villanueva, Marta; Bujanda, Luis; Billadeau, Daniel D; Zhang, Jin-San

    2014-03-07

    Pancreatic ductal adenocarcinoma (PDAC), the most common type of pancreatic tumor, is a highly aggressive human cancer with the lowest five-year survival rate of any human maligancy primarily due to its early- metastasis and lack of response to chemotherapy and radiation. Recent research suggests that PDAC cells comprise a hierarchy of tumor cells that develop around a population of cancer stem cells (CSCs), a small and distinct population of cancer cells that mediates tumoregenesis, metastasis and resistance to standard treatments. Thus, CSCs could be a target for more effective treatment options. Interestingly, pancreatic CSCs are subject to regulation by some of key embryonic stem cell (ESC) transctiption factors abberently expressed in PDAC, such as SOX2, OCT4 and NANOG. ESC transcription factors are important DNA-binding proteins present in both embryonic and adult somatic cells. The critical role of these factors in reprogramming processes makes them essential not only for embryonic development but also tumorigenesis. Here we provide an overview of stem cell transcription factors, particularly SOX2, OCT4, and NANOG, on their expression and function in pancreatic cancer. In contrast to embryonic stem cells, in which OCT4 and SOX2 are tightly regulated and physically interact to regulate a wide spectrum of target genes, de novo SOX2 expression alone in pancreatic cancer cells is sufficient to promote self-renewal, de-differentiation and imparting stemness characteristics via impacting specific cell cycle regulatory genes and epithelial-mesnechymal transtion driver genes. Thus, targeting ESC factors, particularly SOX2, could be a worthy strategy for pancreatic cancer therapy.

  14. Mitochondrial DNA copy number is regulated by DNA methylation and demethylation of POLGA in stem and cancer cells and their differentiated progeny.

    Science.gov (United States)

    Lee, W; Johnson, J; Gough, D J; Donoghue, J; Cagnone, G L M; Vaghjiani, V; Brown, K A; Johns, T G; St John, J C

    2015-02-26

    Mitochondrial DNA (mtDNA) copy number is strictly regulated during differentiation so that cells with a high requirement for ATP generated through oxidative phosphorylation have high mtDNA copy number, whereas those with a low requirement have few copies. Using immunoprecipitation of DNA methylation on 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC), which distinguish between de novo DNA methylation and demethylation, respectively, we set out to determine whether DNA methylation at exon 2 of the human mtDNA-specific polymerase (DNA polymerase gamma A (POLGA)) regulates cell-specific mtDNA copy number in highly proliferative and terminally differentiated cells. Highly proliferative cancer and pluripotent and multipotent cells possessed low mtDNA copy number and were highly methylated at exon 2 of POLGA in contrast to post-mitotic cells. Unlike neural stem cells, cancer cells were unable to differentiate and remained extensively DNA methylated at exon 2 of POLGA. However, mtDNA depletion of cancer cells reduced DNA methylation at exon 2 of POLGA as they replenished mtDNA to form tumours in mice. Glioblastoma cells treated with the DNA demethylation agent 5-azacytidine over 28 days of astrocyte-induced differentiation demethylated exon 2 of POLGA leading to increased mtDNA copy number and expression of the astrocyte endpoint marker glial fibrillary acidic protein (GFAP). However, the demethylation agent vitamin C (VitC) was unable to sustain increased mtDNA copy number and differentiation, as was the case when VitC was withdrawn after short-term treatment. These data demonstrate that DNA demethylation of POLGA is an essential regulator of mtDNA copy number and cellular fate and that cancer cells are only able to modulate DNA methylation of POLGA and mtDNA copy number in the presence of a DNA demethylation agent that inhibits de novo methyltransferase 1 activity.

  15. Induction of cancer stem cell properties in colon cancer cells by defined factors.

    Directory of Open Access Journals (Sweden)

    Nobu Oshima

    Full Text Available Cancer stem cells (CSCs are considered to be responsible for the dismal prognosis of cancer patients. However, little is known about the molecular mechanisms underlying the acquisition and maintenance of CSC properties in cancer cells because of their rarity in clinical samples. We herein induced CSC properties in cancer cells using defined factors. We retrovirally introduced a set of defined factors (OCT3/4, SOX2 and KLF4 into human colon cancer cells, followed by culture with conventional serum-containing medium, not human embryonic stem cell medium. We then evaluated the CSC properties in the cells. The colon cancer cells transduced with the three factors showed significantly enhanced CSC properties in terms of the marker gene expression, sphere formation, chemoresistance and tumorigenicity. We designated the cells with CSC properties induced by the factors, a subset of the transduced cells, as induced CSCs (iCSCs. Moreover, we established a novel technology to isolate and collect the iCSCs based on the differences in the degree of the dye-effluxing activity enhancement. The xenografts derived from our iCSCs were not teratomas. Notably, in contrast to the tumors from the parental cancer cells, the iCSC-based tumors mimicked actual human colon cancer tissues in terms of their immunohistological findings, which showed colonic lineage differentiation. In addition, we confirmed that the phenotypes of our iCSCs were reproducible in serial transplantation experiments. By introducing defined factors, we generated iCSCs with lineage specificity directly from cancer cells, not via an induced pluripotent stem cell state. The novel method enables us to obtain abundant materials of CSCs that not only have enhanced tumorigenicity, but also the ability to differentiate to recapitulate a specific type of cancer tissues. Our method can be of great value to fully understand CSCs and develop new therapies targeting CSCs.

  16. Metallothionein-3 regulates lysosomal function in cultured astrocytes under both normal and oxidative conditions.

    Science.gov (United States)

    Lee, Sook-Jeong; Park, Mi-Ha; Kim, Hyun-Jae; Koh, Jae-Young

    2010-08-01

    Cellular zinc plays a key role in lysosomal change and cell death in neurons and astrocytes under oxidative stress. Here, using astrocytes lacking metallothionein-3 (MT3), a potential source of labile zinc in the brain, we studied the role of MT3 in oxidative stress responses. H(2)O(2) induced a large increase in labile zinc in wild-type (WT) astrocytes, but stimulated only a modest rise in MT3-null astrocytes. In addition, H(2)O(2)-induced lysosomal membrane permeabilization (LMP) and cell death were comparably attenuated in MT3-null astrocytes. Expression and glycosylation of Lamp1 (lysosome-associated membrane protein 1) and Lamp2 were increased in MT3-null astrocytes, and the activities of several lysosomal enzymes were significantly reduced, indicating an effect of MT3 on lysosomal components. Consistent with lysosomal dysfunction in MT3-null cells, the level of LC3-II (microtubule-associated protein 1 light chain 3), a marker of early autophagy, was increased by oxidative stress in WT astrocytes, but not in MT3-null cells. Similar changes in Lamp1, LC3, and cathepsin-D were induced by the lysosomal inhibitors bafilomycin A1, chloroquine, and monensin, indicating that lysosomal dysfunction may lie upstream of changes observed in MT3-null astrocytes. Consistent with this idea, lysosomal accumulation of cholesterol and lipofuscin were augmented in MT3-null astrocytes. Similar to the results seen in MT3-null cells, MT3 knockdown by siRNA inhibited oxidative stress-induced increases in zinc and LMP. These results indicate that MT3 may play a key role in normal lysosomal function in cultured astrocytes.

  17. Co-culture of astrocytes with neurons from injured brain A time-dependent dichotomy

    Institute of Scientific and Technical Information of China (English)

    Xiaojing Xu; Min Wang; Jing Liu; Jingya Lv; Yanan Hu; Huanxiang Zhang

    2011-01-01

    As supportive cells for neuronal growth and development, much effort has been devoted to the role of astrocytes in the normal state. However, the effect of the astrocytes after injury remains elusive. In the present study, neurons isolated from the subventricular zone of injured neonatal rat brains were co-cultured with astrocytes. After 6 days, these astrocytes showed a mature neuron-like appearance and the number of survivingneurons, primary dendrites and total branches was significantly higher than those at 3 days. The neurons began to shrink at 9 days after co-culture with shorter and thinner processes and the number of primary dendrites and total branches was significantly reduced. These experimental findings indicate that astrocytes in the injured brain promote the development of neurons in the early stages of co-culture while these cells reversely inhibit neuronal growth and development at the later states.

  18. Cancer Cells Hijack Gluconeogenic Enzymes to Fuel Cell Growth.

    Science.gov (United States)

    Balsa-Martinez, Eduardo; Puigserver, Pere

    2015-11-19

    In this issue and the October 15th issue of Molecular Cell, studies by Montal et al. (2015) and Vincent et al. (2015) report that certain types of cancer cells utilize the gluconeogenic enzymes phosphoenolpyruvate carboxykinase (PEPCK) and phosphoenolpyruvate carboxykinase 2 (PCK2) to reprogram anabolic metabolism and support cell growth.

  19. Cell polarity signaling in the plasticity of cancer cell invasiveness.

    Science.gov (United States)

    Gandalovičová, Aneta; Vomastek, Tomáš; Rosel, Daniel; Brábek, Jan

    2016-05-03

    Apico-basal polarity is typical of cells present in differentiated epithelium while front-rear polarity develops in motile cells. In cancer development, the transition from epithelial to migratory polarity may be seen as the hallmark of cancer progression to an invasive and metastatic disease. Despite the morphological and functional dissimilarity, both epithelial and migratory polarity are controlled by a common set of polarity complexes Par, Scribble and Crumbs, phosphoinositides, and small Rho GTPases Rac, Rho and Cdc42. In epithelial tissues, their mutual interplay ensures apico-basal and planar cell polarity. Accordingly, altered functions of these polarity determinants lead to disrupted cell-cell adhesions, cytoskeleton rearrangements and overall loss of epithelial homeostasis. Polarity proteins are further engaged in diverse interactions that promote the establishment of front-rear polarity, and they help cancer cells to adopt different invasion modes. Invading cancer cells can employ either the collective, mesenchymal or amoeboid invasion modes or actively switch between them and gain intermediate phenotypes. Elucidation of the role of polarity proteins during these invasion modes and the associated transitions is a necessary step towards understanding the complex problem of metastasis. In this review we summarize the current knowledge of the role of cell polarity signaling in the plasticity of cancer cell invasiveness.

  20. Cancer cells with irons in the fire.

    Science.gov (United States)

    Bystrom, Laura M; Rivella, Stefano

    2015-02-01

    Iron is essential for the growth and proliferation of cells, as well as for many biological processes that are important for the maintenance and survival of the human body. However, excess iron is associated with the development of cancer and other pathological conditions, due in part to the pro-oxidative nature of iron and its damaging effects on DNA. Current studies suggest that iron depletion may be beneficial for patients that have diseases associated with iron overload or other iron metabolism disorders that may increase the risk for cancer. On the other hand, studies suggest that cancer cells are more vulnerable to the effects of iron depletion and oxidative stress in comparison to normal cells. Therefore, cancer patients might benefit from treatments that alter both iron metabolism and oxidative stress. This review highlights the pro-oxidant effects of iron, the relationship between iron and cancer development, the vulnerabilities of the iron-dependent cancer phenotype, and how these characteristics may be exploited to prevent or treat cancer.

  1. Induction of Cancer Stem Cell Properties in Colon Cancer Cells by Defined Factors

    OpenAIRE

    Oshima, Nobu

    2014-01-01

    Oshima N, Yamada Y, Nagayama S, Kawada K, Hasegawa S, et al. (2014) Induction of Cancer Stem Cell Properties in Colon Cancer Cells by Defined Factors. PLoS ONE 9(7): e101735. doi:10.1371/journal.pone.0101735

  2. Persistent oxygen-glucose deprivation induces astrocytic death through two different pathways and calpain-mediated proteolysis of cytoskeletal proteins during astrocytic oncosis.

    Science.gov (United States)

    Cao, Xu; Zhang, Ying; Zou, Liangyu; Xiao, Haibing; Chu, Yinghao; Chu, Xiaofan

    2010-07-26

    Astrocytes are thought to play a role in the maintenance of homeostasis and the provision of metabolic substrates for neurons as well as the coupling of cerebral blood flow to neuronal activity. Accordingly, astrocytic death due to various types of injury can critically influence neuronal survival. The exact pathway of cell death after brain ischemia is under debate. In the present study, we used astrocytes from rat primary culture treated with persistent oxygen-glucose-deprivation (OGD) as a model of ischemia to examine the pathway of cell death and the relevant mechanisms. We observed changes in the cellular morphology, the energy metabolism of astrocytes, and the percentage of apoptosis or oncosis of the astrocytes induced by OGD. Electron microscopy revealed the co-existence of ultrastructural features in both apoptosis and oncosis in individual cells. The cellular ATP content was gradually decreased and the percentages of apoptotic and oncotic cells were increased during OGD. After 4h of OGD, ATP depletion to less than 35% of the control was observed, and oncosis became the primary pathway for astrocytic death. Increased plasma membrane permeability due to oncosis was associated with increased calpain-mediated degradation of several cytoskeletal proteins, including paxillin, vinculin, vimentin and GFAP. Pre-treatment with the calpain inhibitor 3-(4-iodophenyl)-2-mercapto-(Z)-2-propenoic acid (PD150606) could delay the OGD-induced astrocytic oncosis. These results suggest that there is a narrow range of ATP that determines astrocytic oncotic death induced by persistent OGD and that calpain-mediated hydrolysis of the cytoskeletal-associated proteins may contribute to astrocytes oncosis.

  3. Phenotype heterogeneity in cancer cell populations

    Science.gov (United States)

    Almeida, Luis; Chisholm, Rebecca; Clairambault, Jean; Escargueil, Alexandre; Lorenzi, Tommaso; Lorz, Alexander; Trélat, Emmanuel

    2016-06-01

    Phenotype heterogeneity in cancer cell populations, be it of genetic, epigenetic or stochastic origin, has been identified as a main source of resistance to drug treatments and a major source of therapeutic failures in cancers. The molecular mechanisms of drug resistance are partly understood at the single cell level (e.g., overexpression of ABC transporters or of detoxication enzymes), but poorly predictable in tumours, where they are hypothesised to rely on heterogeneity at the cell population scale, which is thus the right level to describe cancer growth and optimise its control by therapeutic strategies in the clinic. We review a few results from the biological literature on the subject, and from mathematical models that have been published to predict and control evolution towards drug resistance in cancer cell populations. We propose, based on the latter, optimisation strategies of combined treatments to limit emergence of drug resistance to cytotoxic drugs in cancer cell populations, in the monoclonal situation, which limited as it is still retains consistent features of cell population heterogeneity. The polyclonal situation, that may be understood as "bet hedging" of the tumour, thus protecting itself from different sources of drug insults, may lie beyond such strategies and will need further developments. In the monoclonal situation, we have designed an optimised therapeutic strategy relying on a scheduled combination of cytotoxic and cytostatic treatments that can be adapted to different situations of cancer treatments. Finally, we review arguments for biological theoretical frameworks proposed at different time and development scales, the so-called atavistic model (diachronic view relying on Darwinian genotype selection in the coursof billions of years) and the Waddington-like epigenetic landscape endowed with evolutionary quasi-potential (synchronic view relying on Lamarckian phenotype instruction of a given genome by reversible mechanisms), to

  4. Squamous cell cancer of the rectum

    Institute of Scientific and Technical Information of China (English)

    Tara Dyson; Peter V Draganov

    2009-01-01

    Squamous cell carcinoma of the rectum is a rare malignancy. It appears to be associated with chronic inflammatory conditions and infections. The clear association seen between Human Papilloma Virus and various squamous cancers has not been firmly established for the squamous cell cancer of the rectum. The presentation is nonspecific and patients tend to present with advanced stage disease. Diagnosis relies on endoscopic examination with biopsy of the lesion. Distinction from squamous cell cancer of the anus can be difficult, but can be facilitated by immunohistochemical staining for cytokeratins. Staging of the cancer with endoscopic ultrasound and computed tomography provides essential information on prognosis and can guide therapy. At present, surgery remains the main therapeutic option; however recent advances have made chemoradiation a valuable therapeutic addition. Squamous cell carcinoma of the rectum is a distinct entity and it is of crucial importance for the practicing Gastroenterologist to be thoroughly familiar with this disease. Compared to adenocarcinoma of the rectum and squamous cell cancer of the anal canal, squamous cell carcinoma of the rectum has different epidemiology, etiology, pathogenesis, and prognosis but, most importantly, requires a different therapeutic approach. This review will examine and summarize the available information regarding this disease from the perspective of the practicing gastroenterologist.

  5. NSAIDs and Cell Proliferation in Colorectal Cancer

    Directory of Open Access Journals (Sweden)

    Raj Ettarh

    2010-06-01

    Full Text Available Colon cancer is common worldwide and accounts for significant morbidity and mortality in patients. Fortunately, epidemiological studies have demonstrated that continuous therapy with NSAIDs offers real promise of chemoprevention and adjunct therapy for colon cancer patients. Tumour growth is the result of complex regulation that determines the balance between cell proliferation and cell death. How NSAIDs affect this balance is important for understanding and improving treatment strategies and drug effectiveness. NSAIDs inhibit proliferation and impair the growth of colon cancer cell lines when tested in culture in vitro and many NSAIDs also prevent tumorigenesis and reduce tumour growth in animal models and in patients, but the relationship to inhibition of tumour cell proliferation is less convincing, principally due to gaps in the available data. High concentrations of NSAIDs are required in vitro to achieve cancer cell inhibition and growth retardation at varying time-points following treatment. However, the results from studies with colon cancer cell xenografts are promising and, together with better comparative data on anti-proliferative NSAID concentrations and doses (for in vitro and in vivo administration, could provide more information to improve our understanding of the relationships between these agents, dose and dosing regimen, and cellular environment.

  6. Germ cell cancer and disorders of spermatogenesis

    DEFF Research Database (Denmark)

    Skakkebaek, N E; Rajpert-De Meyts, E; Jørgensen, N;

    1998-01-01

    in research in the early stages of testicular cancer (carcinoma in situ testis (CIS)) allows us to begin to answer some of these questions. There is more and more evidence that the CIS cell is a gonocyte with stem cell potential, which explains why an adult man can develop a non-seminoma, which...... is a neoplastic caricature of embryonic growth. We consider the possibility that CIS cells may loose their stem cell potential with ageing. Along these lines, a seminoma is regarded a gonocytoma where the single gonocytes have little or no stem cell potential. The Sertoli and Leydig cells, which are activated......Why is there a small peak of germ cell tumours in the postnatal period and a major peak in young age, starting at puberty? And, paradoxically, small risk in old age, although spermatogenesis is a lifelong process? Why is this type of cancer more common in individuals with maldeveloped gonads...

  7. EFFECTS OF CULTURED ASTROCYTES FROM RAT CEREBRAL CORTEX ON THE DEVELOPMENT OF PC12 CELLS%星形神经胶质细胞对PC12细胞生长发育的影响

    Institute of Scientific and Technical Information of China (English)

    莫永炎; 陈瑗; 周玫; 张宝

    2000-01-01

    在神经系统的生长发育过程中,星形胶质细胞对神经元生长发育的作用是一项重要的研究课题。本文以体外培养的SD大鼠大脑皮质星形胶质细胞与PC12神经元按不同细胞数目比例(50:1~1:1)共同培养,并用其制备的条件培养液培养PC12细胞,用快速灵敏的MTT比色法测定PC12神经元的细胞活力,用光学相差显微镜观察PC12细胞形态学变化。结果显示,星形胶质细胞条件培养液可增强PC12细胞活力(MTT测定的 OD值由0.255±0.012提高到0.510±0.036,P<0.001,且细胞折光性较对照组强),却不能促使PC12神经元突起的生出。将星形胶质细胞与PC12细胞按30:1~1:1的比例共同培养时,既可提高PC12细胞折光性和光晕又可促使其突起的生长;如按50:1~40:1的比例共同培养时,只观察到提高PC12细胞折光性和光晕,而无促使其突起生长发育的作用。本文结果提示,PC12神经元细胞活力的提高与星形胶质细胞分泌到条件培养液中的可溶性因子有关,而PC12神经元突起生长发育可能是和与星形胶质细胞的直接接触以及二者的细胞数且比有关。%To investigate effects of cultured astrocytes from Sprague Dawley rat cerebral cortex on the development of PC12 cellsderived from rat pheochromocytoma, PC12 cells were cocultured with astrocyte according to different astrocytes/neurons ratio(50:1~1:1) , or with serum-free conditioned medium of astrocytes(ACM). The vitality of PC12 cells was measured by sensi-tive MTT method and their morphologic features were observed by Olympus light microscope. The results showed: (1) WhenPC12 cells were cultured with ACM, compared with the control group, the vitality of PC12 cells was increased significantly (0.255+0. 012 vs 0. 510±0. 036, P<0. 001) and the morphological changes were not obvious in the experimental group. (2) WhenPC12 cells were cocultured with astrocyte in the ratio of 30: 1

  8. Cell-of-Origin of Cancer versus Cancer Stem Cells: Assays and Interpretations.

    Science.gov (United States)

    Rycaj, Kiera; Tang, Dean G

    2015-10-01

    A tumor originates from a normal cell that has undergone tumorigenic transformation as a result of genetic mutations. This transformed cell is the cell-of-origin for the tumor. In contrast, an established clinical tumor is sustained by subpopulations of self-renewing cancer cells operationally called cancer stem cells (CSC) that can generate, intraclonally, both tumorigenic and nontumorigenic cells. Identifying and characterizing tumor cell-of-origin and CSCs should help elucidate tumor cell heterogeneity, which, in turn, should help understand tumor cell responses to clinical treatments, drug resistance, tumor relapse, and metastatic spread. Both tumor transplantation and lineage-tracing assays have been helpful in characterizing these cancer cell populations, although each system has its strengths and caveats. In this article, we briefly review and summarize advantages and limitations of both assays in support of a combinatorial approach to accurately define the roles of both cancer-initiating and cancer-propagating cells. As an aside, we also wish to clarify the definitions of cancer cell-of-origin and CSCs, which are often interchangeably used by mistake.

  9. Vitro Culture and Immunohistochemical Identification of Astrocytes of Infantile Optic Nerve

    Institute of Scientific and Technical Information of China (English)

    Jianliang Zheng; Yuqing Lan; Jie Zhang; Yan Guo; Yan Luo

    2000-01-01

    Objective: To culture astrocytes of optic nerve and to establish the cell lines for further study of healing process after optic nerve trauma.Methods: Optic nerve astrocytes of infantile and adults with sudden death were cultured by tissue inoculation or tissue digestion with 0. 25% Trypsin and 0. 06% EDTA. The second and fourth passage cells were stained with HE and anti- GFAP, S-100 protein, Vimentin, and CD34 antibodies.Results: The trypsinized astrocytes of infantile optic nerve reached confluence in 7 days,but the astrocytes of adults weren't successfully cultured. The cultured cells were in polygonal shape with processes; the cytoplasm was abundant and pink; the cells had light-blue nuclei. These cells were positive in GFAP, S-100 protein and vimentin staining, and negative in CD34 staining.Conclusions: The results showed that astrocytes of infantile optic nerve can be successfully cultured and trypsinization is a better method than tissue inoculation. The culture of infantile astrocytes is easier than that of adult astrocytes. Immunohistochemistry were used to determine the source and type of those cultured cells.

  10. Stem Cell Transplants in Cancer Treatment

    Science.gov (United States)

    Stem cell transplants are procedures that restore blood-forming stem cells in cancer patients who have had theirs destroyed by very high doses of chemotherapy or radiation therapy. Learn about the types of transplants and side effects that may occur.

  11. Enteric Bacteria and Cancer Stem Cells

    Directory of Open Access Journals (Sweden)

    Jun Sun

    2011-01-01

    Full Text Available Intestinal bacteria can contribute to cell proliferation and cancer development, particularly in chronic infectious diseases in which bacteria and/or bacterial components might interfere with cell function. The number of microbial cells within the gut lumen is estimated to be 100 trillion, which is about 10-times larger than the number of eukaryotic cells in the human body. Because of the complexity of the gut flora, identifying the specific microbial agents related to human diseases remains challenging. Recent studies have demonstrated that the stemness of colon cancer cells is, in part, orchestrated by the microenvironment and is defined by high Wnt activity. In this review article, we will discuss recent progress with respect to intestinal stem cells, cancer stem cells, and the molecular mechanisms of enteric bacteria in the activation of the Wnt pathway. We will also discuss the roles of other pathways, including JAK-STAT, JNK, and Notch, in regulating stem cell niches during bacterial infections using Drosophila models. Insights gained from understanding how host-bacterial interaction during inflammation and cancer may serve as a paradigm for understanding the nature of self-renewal signals.

  12. Proteomic analysis of astrocytic secretion that regulates neurogenesis using quantitative amine-specific isobaric tagging

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Hu; Zhou, Wenhao [Children' s Hospital of Fudan University, 399 Wanyuan Road, Shanghai 201102 (China); Wei, Liming; Zhong, Fan [Institutes of Biomedical Sciences, Fudan University, 138 Yixueyuan Roda, Shanghai 200032 (China); Yang, Yi, E-mail: yyang@shmu.edu.cn [Children' s Hospital of Fudan University, 399 Wanyuan Road, Shanghai 201102 (China)

    2010-01-08

    Astrocytes are essential components of neurogenic niches that affect neurogenesis through membrane association and/or the release of soluble factors. To identify factors released from astrocytes that could regulate neural stem cell differentiation and proliferation, we used mild oxygen-glucose deprivation (OGD) to inhibit the secretory capacity of astrocytes. Using the Transwell co-culture system, we found that OGD-treated astrocytes could not promote neural stem cell differentiation and proliferation. Next, isobaric tagging for the relative and absolute quantitation (iTRAQ) proteomics techniques was performed to identify the proteins in the supernatants of astrocytes (with or without OGD). Through a multi-step analysis and gene ontology classification, 130 extracellular proteins were identified, most of which were involved in neuronal development, the inflammatory response, extracellular matrix composition and supportive functions. Of these proteins, 44 had never been reported to be produced by astrocytes. Using ProteinPilot software analysis, we found that 60 extracellular proteins were significantly altered (27 upregulated and 33 downregulated) in the supernatant of OGD-treated astrocytes. Among these proteins, 7 have been reported to be able to regulate neurogenesis, while others may have the potential to regulate neurogenesis. This study profiles the major proteins released by astrocytes, which play important roles in the modulation of neurogenesis.

  13. IFN-γ signaling to astrocytes protects from autoimmune mediated neurological disability.

    Directory of Open Access Journals (Sweden)

    Claudia Hindinger

    Full Text Available Demyelination and axonal degeneration are determinants of progressive neurological disability in patients with multiple sclerosis (MS. Cells resident within the central nervous system (CNS are active participants in development, progression and subsequent control of autoimmune disease; however, their individual contributions are not well understood. Astrocytes, the most abundant CNS cell type, are highly sensitive to environmental cues and are implicated in both detrimental and protective outcomes during autoimmune demyelination. Experimental autoimmune encephalomyelitis (EAE was induced in transgenic mice expressing signaling defective dominant-negative interferon gamma (IFN-γ receptors on astrocytes to determine the influence of inflammation on astrocyte activity. Inhibition of IFN-γ signaling to astrocytes did not influence disease incidence, onset, initial progression of symptoms, blood brain barrier (BBB integrity or the composition of the acute CNS inflammatory response. Nevertheless, increased demyelination at peak acute disease in the absence of IFN-γ signaling to astrocytes correlated with sustained clinical symptoms. Following peak disease, diminished clinical remission, increased mortality and sustained astrocyte activation within the gray matter demonstrate a critical role of IFN-γ signaling to astrocytes in neuroprotection. Diminished disease remission was associated with escalating demyelination, axonal degeneration and sustained inflammation. The CNS infiltrating leukocyte composition was not altered; however, decreased IL-10 and IL-27 correlated with sustained disease. These data indicate that astrocytes play a critical role in limiting CNS autoimmune disease dependent upon a neuroprotective signaling pathway mediated by engagement of IFN-γ receptors.

  14. Concurrent loss and proliferation of astrocytes following lateral fluid percussion brain injury in the adult rat.

    Science.gov (United States)

    Hill-Felberg, S J; McIntosh, T K; Oliver, D L; Raghupathi, R; Barbarese, E

    1999-07-15

    Astrocyte populations were analyzed over a period of 1 month in the hippocampus following lateral fluid percussion (FP) brain injury. Rats (n = 23) were subjected either to a brain injury of moderate severity, or to anesthesia and surgery without injury (n = 7). At 3 days, 1, 2, or 4 weeks postinjury, subgroups of animals were sacrificed and the brains removed and sectioned for histochemical analysis. The density of astrocytes, identified with gold sublimate staining, decreased significantly in the ipsilateral hippocampus of injured rats 3 days following injury, eventually falling to 64% of the total astrocyte population present in uninjured animals by 1 week postinjury. One month postinjury, the density of hippocampal astrocytes had returned to 85% of the total number of astrocytes observed in the hippocampus of uninjured animals. In order to characterize the post-traumatic formation of new astrocytes, immunohistochemistry was performed using antibodies to proliferating cell nuclear antigen (PCNA) and to glial fibriallary acidic protein (GFAP). Positive immunolabeling for both PCNA and GFAP was most abundant at 3 days following FP brain injury in regions where the blood brain barrier was compromised, and was not detectable by 1 month postinjury. These results indicate that astrocyte proliferation after injury may be evoked by mitogens released from vascular sources, and may be an attempt to compensate for some of the astrocytic cell loss observed after injury.

  15. Targeting Strategies for Renal Cell Carcinoma: From Renal Cancer Cells to Renal Cancer Stem Cells.

    Science.gov (United States)

    Yuan, Zhi-Xiang; Mo, Jingxin; Zhao, Guixian; Shu, Gang; Fu, Hua-Lin; Zhao, Wei

    2016-01-01

    Renal cell carcinoma (RCC) is a common form of urologic tumor that originates from the highly heterogeneous epithelium of renal tubules. Over the last decade, targeting therapies to renal cancer cells have transformed clinical care for RCC. Recently, it was proposed that renal cancer stem cells (CSCs) isolated from renal carcinomas were responsible for driving tumor growth and resistance to conventional chemotherapy and radiotherapy, according to the theory of CSCs; this has provided the rationale for therapies targeting this aggressive cell population. Precise identification of renal CSC populations and the complete cell hierarchy will accurately inform characterization of disease subtypes. This will ultimately contribute to more personalized and targeted therapies. Here, we summarize potential targeting strategies for renal cancer cells and renal CSCs, including tyrosine kinase inhibitors, mammalian target of rapamycin inhibitors (mTOR), interleukins, CSC marker inhibitors, bone morphogenetic protein-2, antibody drug conjugates, and nanomedicine. In conclusion, targeting therapies for RCC represent new directions for exploration and clinical investigation and they plant a seed of hope for advanced clinical care.

  16. Astrocytes in oligodendrocyte lineage development and white matter pathology

    Directory of Open Access Journals (Sweden)

    Jiasi eLi

    2016-05-01

    Full Text Available White matter is primarily composed of myelin and myelinated axons. Structural and functional completeness of myelin is critical for the reliable and efficient transmission of information. White matter injury has been associated with the development of many demyelinating diseases. Despite a variety of scientific advances aimed at promoting re-myelination, their benefit has proven at best to be marginal. Research suggests that the failure of the re-myelination process may be the result of an unfavorable microenvironment. Astrocytes, are the most ample and diverse type of glial cells in central nervous system which display multiple functions for the cells of the oligodendrocytes lineage. As such, much attention has recently been drawn to astrocyte function in terms of white matter myelin repair. They are different in white matter from those in grey matter in specific regards to development, morphology, location, protein expression and other supportive functions. During the process of demyelination and re-myelination, the functions of astrocytes are dynamic in that they are able to change functions in accordance to different time points, triggers or reactive pathways resulting in vastly different biologic effects. They have pivotal effects on oligodendrocytes and other cell types in the oligodendrocyte lineage by serving as an energy supplier, a participant of immunological and inflammatory functions, a source of trophic factors and iron and a sustainer of homeostasis. Astrocytic impairment has been shown to be directly linked to the development of neuromyelities optica. In addition, astroctyes have also been implicated in other white matter conditions such as psychiatric disorders and neurodegenerative diseases such as Alzheimer’s disease, multiple sclerosis and amyotrophic lateral sclerosis. Inhibiting specifically detrimental signaling pathways in astrocytes while preserving their beneficial functions may be a promising approach for

  17. Astrocytes in Oligodendrocyte Lineage Development and White Matter Pathology

    Science.gov (United States)

    Li, Jiasi; Zhang, Lei; Chu, Yongxin; Namaka, Michael; Deng, Benqiang; Kong, Jiming; Bi, Xiaoying

    2016-01-01

    White matter is primarily composed of myelin and myelinated axons. Structural and functional completeness of myelin is critical for the reliable and efficient transmission of information. White matter injury has been associated with the development of many demyelinating diseases. Despite a variety of scientific advances aimed at promoting re-myelination, their benefit has proven at best to be marginal. Research suggests that the failure of the re-myelination process may be the result of an unfavorable microenvironment. Astrocytes, are the most ample and diverse type of glial cells in central nervous system (CNS) which display multiple functions for the cells of the oligodendrocytes lineage. As such, much attention has recently been drawn to astrocyte function in terms of white matter myelin repair. They are different in white matter from those in gray matter in specific regards to development, morphology, location, protein expression and other supportive functions. During the process of demyelination and re-myelination, the functions of astrocytes are dynamic in that they are able to change functions in accordance to different time points, triggers or reactive pathways resulting in vastly different biologic effects. They have pivotal effects on oligodendrocytes and other cell types in the oligodendrocyte lineage by serving as an energy supplier, a participant of immunological and inflammatory functions, a source of trophic factors and iron and a sustainer of homeostasis. Astrocytic impairment has been shown to be directly linked to the development of neuromyelities optica (NMO). In addition, astroctyes have also been implicated in other white matter conditions such as psychiatric disorders and neurodegenerative diseases such as Alzheimer’s disease (AD), multiple sclerosis (MS) and amyotrophic lateral sclerosis (ALS). Inhibiting specifically detrimental signaling pathways in astrocytes while preserving their beneficial functions may be a promising approach for

  18. Astrocytes mediate the neuroprotective effects of Tibolone following brain injury

    Directory of Open Access Journals (Sweden)

    Luis Miguel Garcia-Segura

    2015-04-01

    Full Text Available Recently, astrocytes have become a key central player in mediating important functions in the brain. These physiological processes include neurotransmitter recycling, energy management, metabolic shuttle, immune sensing, K+ buffer, antioxidant supply and release of neurotrophic factors and gliotransmitters. These astrocytic roles are somehow altered upon brain injury, therefore strategies aimed at better protecting astrocytes are an essential asset to maintain brain homeostasis. In this context, estrogenic compounds, such as Tibolone, have attracted attention for their beneficial effects in acute and chronic degenerative diseases. Tibolone may act through binding to estrogen, androgen or progesterone receptors and exert protective effects by reducing astrocytes cell death and oxidative stress signaling mechanisms. Although Tibolone has a multifactorial effect in the brain, its mechanisms of action are not completely understood. In this work, we highlight the role of Tibolone in brain protection upon damage, how astrocytes might mediate part of its neuroprotective actions and discuss the effects of Tibolone in diminishing the harmful consequences of a metabolic insult and energy failure in the setting of a pathological event.

  19. Cancer Stem Cells: A Moving Target.

    Science.gov (United States)

    Francipane, Maria Giovanna; Chandler, Julie; Lagasse, Eric

    2013-06-01

    Even though the number of anti-cancer drugs entering clinical trials and approved by the FDA has increased in recent years, many cancer patients still experience poor survival outcome. The main explanation for such a dismal prognosis is that current therapies might leave behind a population of cancer cells with the capacity for long-term self-renewal, so-called cancer stem cells (CSCs), from which most tumors are believed to be derived and fueled. CSCs might favor local and distant recurrence even many years after initial treatment, thus representing a potential target for therapies aimed at improving clinical outcome. In this review, we will address the CSC hypothesis with a particular emphasis on its current paradigms and debates, and discuss several mechanisms of CSC resistance to conventional therapies.

  20. Altered calcium signaling in cancer cells.

    Science.gov (United States)

    Stewart, Teneale A; Yapa, Kunsala T D S; Monteith, Gregory R

    2015-10-01

    It is the nature of the calcium signal, as determined by the coordinated activity of a suite of calcium channels, pumps, exchangers and binding proteins that ultimately guides a cell's fate. Deregulation of the calcium signal is often deleterious and has been linked to each of the 'cancer hallmarks'. Despite this, we do not yet have a full understanding of the remodeling of the calcium signal associated with cancer. Such an understanding could aid in guiding the development of therapies specifically targeting altered calcium signaling in cancer cells during tumorigenic progression. Findings from some of the studies that have assessed the remodeling of the calcium signal associated with tumorigenesis and/or processes important in invasion and metastasis are presented in this review. The potential of new methodologies is also discussed. This article is part of a Special Issue entitled: Membrane channels and transporters in cancers.

  1. Getting to the heart of the matter in cancer: Novel approaches to targeting cancer stem cells.

    Science.gov (United States)

    Colvin, Hugh; Mori, Masaki

    2017-01-01

    Cancer is one of the leading causes of deaths worldwide. While cancers may initially show good response to chemotherapy or radiotherapy, it is not uncommon for them to recur at a later date. This phenomenon may be explained by the existence of a small population of cancer stem cells, which are inherently resistant to anti-cancer treatment as well as being capable of self-renewal. Therefore, while most of the tumour bulk consisting of cells that are not cancer stem cells respond to treatment, the cancer stem cells remain, leading to disease recurrence. Following this logic, the effective targeting of cancer stem cells holds promise for providing long-term cure in individuals with cancer. Cancer stem cells, like normal stem cells are endowed with mechanisms to protect themselves against a wide range of insults including anti-cancer treatments, such as the enhancement of the DNA damage response and the ability to extrude drugs. It is therefore important to develop new strategies if cancer stem cells are to be eradicated. In this review, we describe the strategies that we have developed to target cancer stem cells. These strategies include the targeting of the histone demethylase jumonji, AT rich interactive domain 1B (JARID1B), which we found to be functionally significant in the maintenance of cancer stem cells. Other strategies being pursued include reprogramming of cancer stem cells and the targeting of a functional cell surface marker of liver cancer stem cells, the aminopeptidase CD13.

  2. Identification and pharmacological characterization of the histamine H3 receptor in cultured rat astrocytes.

    Science.gov (United States)

    Mele, Tina; Jurič, Damijana Mojca

    2013-11-15

    Recently we reported that cultured rat cortical astrocytes express histamine H3 receptor that is functionally coupled to Gi/o proteins and participates to the stimulatory effect of histamine. Due to the lack of data on the distribution of histamine H3 receptors on glial cells we further investigated their presence in cultured astrocytes from different brain regions. Real-time PCR was performed to examine the expression of native histamine H3 receptor in cultured rat astrocytes from cortex,cerebellum, hippocampus and striatum.Double-antigen immunofluorescence staining and[3H]N-α-methylhistamine([3H]NαMH) binding studies were utilized to specifically identify and characterize receptor binding sites in astrocytes. Histamine H3 receptor mRNA was detected in rat astrocytes from all the regions under investigation with the highest levels in striatal astrocytes followed by hippocampal astrocytes and approximately equal levels in cerebellar and cortical astrocytes.Double-antigen immunofluorescence confirmed the presence of histamine H3 receptors on the membrane of all examined astroglial populations.[3H]NαMH bound with high affinity and specificity to an apparently single class of saturable sites on cortical astrocytic membranes(KD¼4.5570.46 nM; Bmax¼5.6370.21 fmol/mg protein)and competition assays with selective agonists and antagonists were consistent with labeling of histamine H3 receptor(range of pKi values 7.50–8.87). Our study confirmed the ability of cultured astrocytes from different rat brain regions to express histamine H3 receptors.The observed diverse distribution of the receptors within various astrocytic populations possibly mirrors their heterogeneity in the brain and indicates their active involvement in histamine-mediated effects.

  3. DJ-1 immunoreactivity in human brain astrocytes is dependent on infarct presence and infarct age.

    Science.gov (United States)

    Mullett, Steven J; Hamilton, Ronald L; Hinkle, David A

    2009-04-01

    DJ-1 is a protein with anti-oxidative stress and anti-apoptotic properties that is abundantly expressed in reactive CNS astrocytes in chronic neurodegenerative disorders such as Parkinson's disease (PD), Alzheimer's disease (AD), and Pick's disease. Genetic mutations which eliminate DJ-1 expression in humans are sufficient to produce an early-onset form of familial PD, PARK7, suggesting that DJ-1 is a critical component of the neuroprotective arsenal of the brain. Previous studies in parkinsonism/dementia brain tissues have revealed that reactive astrocytes within and surrounding incidentally identified infarcts were often robustly immunoreactive for DJ-1, especially if the infarcts showed histological features consistent with older age. Given this, we sought to evaluate astrocytic DJ-1 expression in human stroke more extensively, and with a particular emphasis on determining whether immunohistochemical DJ-1 expression in astrocytes correlates with histological infarct age. The studies presented here show that DJ-1 is abundantly expressed in reactive infarct region astrocytes in both gray and white matter, that subacute and chronic infarct region astrocytes are much more robustly DJ-1+ than are acute infarct and non-infarct region astrocytes, and that DJ-1 staining intensity in astrocytes generally correlates with that of the reactive astrocyte marker GFAP. Confocal imaging of DJ-1 and GFAP dual-labelled human brain sections were used to confirm the localization to and expression of DJ-1 in astrocytes. Neuronal DJ-1 staining was minimal under all infarct and non-infarct conditions. Our data support the conclusion that the major cellular DJ-1 response to stroke in the human brain is astrocytic, and that there is a temporal correlation between DJ-1 expression in these cells and advanced infarct age.

  4. Microfluidics and cancer analysis: cell separation, cell/tissue culture, cell mechanics, and integrated analysis systems.

    Science.gov (United States)

    Pappas, Dimitri

    2016-01-21

    Among the growing number of tools available for cancer studies, microfluidic systems have emerged as a promising analytical tool to elucidate cancer cell and tumor function. Microfluidic methods to culture cells have created approaches to provide a range of environments from single-cell analysis to complex three-dimensional devices. In this review we discuss recent advances in tumor cell culture, cancer cell analysis, and advanced studies enabled by microfluidic systems.

  5. Targeting regulatory T cells in cancer.

    LENUS (Irish Health Repository)

    Byrne, William L

    2012-01-31

    Infiltration of tumors by regulatory T cells confers growth and metastatic advantages by inhibiting antitumor immunity and by production of receptor activator of NF-kappaB (RANK) ligand, which may directly stimulate metastatic propagation of RANK-expressing cancer cells. Modulation of regulatory T cells can enhance the efficacy of cancer immunotherapy. Strategies include depletion, interference with function, inhibition of tumoral migration, and exploitation of T-cell plasticity. Problems with these strategies include a lack of specificity, resulting in depletion of antitumor effector T cells or global interruption of regulatory T cells, which may predispose to autoimmune diseases. Emerging technologies, such as RNA interference and tetramer-based targeting, may have the potential to improve selectivity and efficacy.

  6. Glioactive ATP controls BDNF recycling in cortical astrocytes

    Science.gov (United States)

    Vignoli, Beatrice; Canossa, Marco

    2017-01-01

    ABSTRACT We have recently reported that long-term memory retention requires synaptic glia for proBDNF uptake and recycling. Through the recycling course, glial cells release endocytic BDNF, a mechanism that is activated in response to glutamate via AMPA and mGluRI/II receptors. Cortical astrocytes express receptors for many different transmitters suggesting for a complex signaling controlling endocytic BDNF secretion. Here, we demonstrated that the extracellular nucleotide ATP, activating P2X and P2Y receptors, regulates endocytic BDNF secretion in cultured astrocytes. Our data indicate that distinct glioactive molecules can participate in BDNF glial recycling and suggest that cortical astrocytes contributing to neuronal plasticity can be influenced by neurotransmitters in tune with synaptic needs.

  7. The indispensable roles of microglia and astrocytes during brain development

    Directory of Open Access Journals (Sweden)

    Kitty Reemst

    2016-11-01

    Full Text Available Glia are essential for brain functioning during development and in the adult brain. Here, we discuss the various roles of both microglia and astrocytes, and their interactions during brain development. Although both cells are fundamentally different in origin and function, they often affect the same developmental processes such as neuro-/gliogenesis, angiogenesis, axonal outgrowth, synaptogenesis and synaptic pruning. Due to their important instructive roles in these processes, dysfunction of microglia or astrocytes during brain development could contribute to neurodevelopmental disorders and potentially even late-onset neuropathology. A better understanding of the origin, differentiation process and developmental functions of microglia and astrocytes will help to fully appreciate their role both in the developing as well as in the adult brain, in health and disease.

  8. Triptolide upregulates NGF synthesis in rat astrocyte cultures.

    Science.gov (United States)

    Xue, Bing; Jiao, Jian; Zhang, Lei; Li, Kai-Rong; Gong, Yun-Tao; Xie, Jun-Xia; Wang, Xiao-Min

    2007-07-01

    Triptolide (T10), an extract from the traditional Chinese herb, Tripterygium wilfordii Hook F (TWHF), has been shown to attenuate the rotational behavior induced by D: -amphetamine and prevent the loss of dopaminergic neurons in the substantia nigra in rat models of Parkinson's disease. To examine if the neuroprotective effect is mediated by its stimulation of production of neurotrophic factors from astrocytes, we investigated the effect of T10 on synthesis and release of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF) in rat astrocyte cultures. T10 did not affect the synthesis and release of either BDNF or GDNF. However, it significantly increased NGF mRNA expression. It also increased both intracellular NGF and NGF level in culture medium. These results indicate that the neuroprotective effect of T10 might be mediated, at least in part, via a stimulation of the production and release of NGF in astrocytes.

  9. From cell signaling to cancer therapy

    Institute of Scientific and Technical Information of China (English)

    Jin DING; Yun FENG; Hong-yang WANG

    2007-01-01

    Cancer has been seriously threatening the health and life of humans for a long period. Despite the intensive effort put into revealing the underlying mechanisms of cancer, the detailled machinery of carcinogenesis is still far from fully understood.Numerous studies have illustrated that cell signaling is extensively involved in tumor initiation, promotion and progression. Therefore, targeting the key mol-ecules in the oncogenic signaling pathway might be one of the most promising ways to conquer cancer. Some targeted drugs, such as imatinib mesylate (Gleevec),herceptin, gefitinib (Iressa), sorafenib (Nexavar) and sunitinib (Sutent), which evolve from monotarget drug into multitarget ones, have been developed with encouraging effects.

  10. The telomerase inhibitor imetelstat depletes cancer stem cells in breast and pancreatic cancer cell lines.

    Science.gov (United States)

    Joseph, Immanual; Tressler, Robert; Bassett, Ekaterina; Harley, Calvin; Buseman, Christen M; Pattamatta, Preeti; Wright, Woodring E; Shay, Jerry W; Go, Ning F

    2010-11-15

    Cancer stem cells (CSC) are rare drug-resistant cancer cell subsets proposed to be responsible for the maintenance and recurrence of cancer and metastasis. Telomerase is constitutively active in both bulk tumor cell and CSC populations but has only limited expression in normal tissues. Thus, inhibition of telomerase has been shown to be a viable approach in controlling cancer growth in nonclinical studies and is currently in phase II clinical trials. In this study, we investigated the effects of imetelstat (GRN163L), a potent telomerase inhibitor, on both the bulk cancer cells and putative CSCs. When breast and pancreatic cancer cell lines were treated with imetelstat in vitro, telomerase activity in the bulk tumor cells and CSC subpopulations were inhibited. Additionally, imetelstat treatment reduced the CSC fractions present in the breast and pancreatic cell lines. In vitro treatment with imetelstat, but not control oligonucleotides, also reduced the proliferation and self-renewal potential of MCF7 mammospheres and resulted in cell death after imetelstat, suggesting a mechanism of action independent of telomere shortening for the effects of imetelstat on the CSC subpopulations. Our results suggest that imetelstat-mediated depletion of CSCs may offer an alternative mechanism by which telomerase inhibition may be exploited for cancer therapy.

  11. Pre-Conditioning Induces the Precocious Differentiation of Neonatal Astrocytes to Enhance Their Neuroprotective Properties

    Directory of Open Access Journals (Sweden)

    Ellora Sen

    2011-07-01

    Full Text Available Hypoxic preconditioning reprogrammes the brain's response to subsequent H/I (hypoxia-ischaemia injury by enhancing neuroprotective mechanisms. Given that astrocytes normally support neuronal survival and function, the purpose of the present study was to test the hypothesis that a hypoxic preconditioning stimulus would activate an adaptive astrocytic response. We analysed several functional parameters 24 h after exposing rat pups to 3 h of systemic hypoxia (8% O2. Hypoxia increased neocortical astrocyte maturation as evidenced by the loss of GFAP (glial fibrillary acidic proteinpositive cells with radial morphologies and the acquisition of multipolar GFAP-positive cells. Interestingly, many of these astrocytes had nuclear S100B. Accompanying their differentiation, there was increased expression of GFAP, GS (glutamine synthetase, EAAT-1 (excitatory amino acid transporter-1; also known as GLAST, MCT-1 (monocarboxylate transporter-1 and ceruloplasmin. A subsequent H/I insult did not result in any further astrocyte activation. Some responses were cell autonomous, as levels of GS and MCT-1 increased subsequent to hypoxia in cultured forebrain astrocytes. In contrast, the expression of GFAP, GLAST and ceruloplasmin remained unaltered. Additional experiments utilized astrocytes exposed to exogenous dbcAMP (dibutyryl-cAMP, which mimicked several aspects of the preconditioning response, to determine whether activated astrocytes could protect neurons from subsequent excitotoxic injury. dbcAMP treatment increased GS and glutamate transporter expression and function, and as hypothesized, protected neurons from glutamate excitotoxicity. Taken altogether, these results indicate that a preconditioning stimulus causes the precocious differentiation of astrocytes and increases the acquisition of multiple astrocytic functions that will contribute to the neuroprotection conferred by a sublethal preconditioning stress.

  12. Pre-conditioning induces the precocious differentiation of neonatal astrocytes to enhance their neuroprotective properties

    Directory of Open Access Journals (Sweden)

    Sandra J Hewett

    2011-07-01

    Full Text Available Hypoxic preconditioning reprogrammes the brain's response to subsequent H/I (hypoxia–ischaemia injury by enhancing neuroprotective mechanisms. Given that astrocytes normally support neuronal survival and function, the purpose of the present study was to test the hypothesis that a hypoxic preconditioning stimulus would activate an adaptive astrocytic response. We analysed several functional parameters 24 h after exposing rat pups to 3 h of systemic hypoxia (8% O2. Hypoxia increased neocortical astrocyte maturation as evidenced by the loss of GFAP (glial fibrillary acidic protein-positive cells with radial morphologies and the acquisition of multipolar GFAP-positive cells. Interestingly, many of these astrocytes had nuclear S100B. Accompanying their differentiation, there was increased expression of GFAP, GS (glutamine synthetase, EAAT-1 (excitatory amino acid transporter-1; also known as GLAST, MCT-1 (monocarboxylate transporter-1 and ceruloplasmin. A subsequent H/I insult did not result in any further astrocyte activation. Some responses were cell autonomous, as levels of GS and MCT-1 increased subsequent to hypoxia in cultured forebrain astrocytes. In contrast, the expression of GFAP, GLAST and ceruloplasmin remained unaltered. Additional experiments utilized astrocytes exposed to exogenous dbcAMP (dibutyryl-cAMP, which mimicked several aspects of the preconditioning response, to determine whether activated astrocytes could protect neurons from subsequent excitotoxic injury. dbcAMP treatment increased GS and glutamate transporter expression and function, and as hypothesized, protected neurons from glutamate excitotoxicity. Taken altogether, these results indicate that a preconditioning stimulus causes the precocious differentiation of astrocytes and increases the acquisition of multiple astrocytic functions that will contribute to the neuroprotection conferred by a sublethal preconditioning stress.

  13. The cancer stem cell theory: is it correct?

    Science.gov (United States)

    Yoo, Min-Hyuk; Hatfield, Dolph L

    2008-11-30

    The cancer stem cell hypothesis posits that tumor growth is driven by a rare subpopulation of cells, designated cancer stem cells (CSC). Studies supporting this theory are based in large part on xenotransplantation experiments wherein human cancer cells are grown in immunocompromised mice and only CSC, often constituting less than 1% of the malignancy, generate tumors. Herein, we show that all colonies derived from randomly chosen single cells in mouse lung and breast cancer cell lines form tumors following allografting histocompatible mice. Our study suggests that the majority of malignant cells rather than CSC can sustain tumors and that the cancer stem cell theory must be reevaluated.

  14. Cell Membrane Softening in Cancer Cells

    Science.gov (United States)

    Schmidt, Sebastian; Händel, Chris; Käs, Josef

    Biomechanical properties are useful characteristics and regulators of the cell's state. Current research connects mechanical properties of the cytoskeleton to many cellular processes but does not investigate the biomechanics of the plasma membrane. We evaluated thermal fluctuations of giant plasma membrane vesicles, directly derived from the plasma membranes of primary breast and cervical cells and observed a lowered rigidity in the plasma membrane of malignant cells compared to non-malignant cells. To investigate the specific role of membrane rigidity changes, we treated two cell lines with the Acetyl-CoA carboxylase inhibitor Soraphen A. It changed the lipidome of cells and drastically increased membrane stiffness by up regulating short chained membrane lipids. These altered cells had a decreased motility in Boyden chamber assays. Our results indicate that the thermal fluctuations of the membrane, which are much smaller than the fluctuations driven by the cytoskeleton, can be modulated by the cell and have an impact on adhesion and motility.

  15. Sphingosine 1-Phosphate and Cancer: Lessons from Thyroid Cancer Cells

    Directory of Open Access Journals (Sweden)

    Kid Törnquist

    2013-05-01

    Full Text Available Sphingomyelin is found in the cell membrane of all eukaryotic cells, and was for a long time considered merely as a structural component. However, during the last two decades, metabolites of sphingomyelin, especially sphingosine 1-phosphate (S1P, have proven to be physiologically significant regulators of cell function. Through its five different G protein-coupled receptors, S1P regulates a wide array of cellular processes, ranging from stimulating cellular proliferation and migration, to the inhibition of apoptosis and induction of angiogenesis and modulation of cellular calcium homeostasis. Many of the processes regulated by S1P are important for normal cell physiology, but may also induce severe pathological conditions, especially in malignancies like cancer. Thus, understanding S1P signaling mechanisms has been the aim of a multitude of investigations. Great interest has also been shown in understanding the action of sphingosine kinase (SphK, i.e., the kinase phosphorylating sphingosine to S1P, and the interactions between S1P and growth factor signaling. In the present review, we will discuss recent findings regarding the possible importance of S1P and SphK in the etiology of thyroid cancer. Although clinical data is still scarce, our in vitro findings suggest that S1P may function as a “double-edged sword”, as the receptor profile of thyroid cancer cells largely determines whether S1P stimulates or blocks cellular migration. We will also discuss the interactions between S1P- and VEGF-evoked signaling, and the importance of a S1P1-VEGF receptor 2 complex in thyroid cancer cells.

  16. The metabolic landscape of cancer stem cells.

    Science.gov (United States)

    Dando, Ilaria; Dalla Pozza, Elisa; Biondani, Giulia; Cordani, Marco; Palmieri, Marta; Donadelli, Massimo

    2015-09-01

    Cancer stem cells (CSCs) are a sub-population of quiescent cells endowed with self-renewal properties that can sustain the malignant behavior of the tumor mass giving rise to more differentiated cancer cells. For this reason, the specific killing of CSCs represents one of the most important challenges of the modern molecular oncology. However, their particular resistance to traditional chemotherapy and radiotherapy imposes a thorough understanding of their biological and biochemical features. The metabolic peculiarities of CSCs may be a therapeutic and diagnostic opportunity in cancer research. In this review, we summarize the most significant discoveries on the metabolism of CSCs describing and critically analyzing the studies supporting either glycolysis or mitochondrial oxidative phosphorylation as a primary source of energy for CSCs.

  17. GLUL Promotes Cell Proliferation in Breast Cancer.

    Science.gov (United States)

    Wang, Yanyan; Fan, Shaohua; Lu, Jun; Zhang, Zifeng; Wu, Dongmei; Wu, Zhiyong; Zheng, Yuanlin

    2016-10-28

    Glutamate-ammonia ligase (GLUL) belongs to the glutamine synthetase family. It catalyzes the synthesis of glutamine from glutamate and ammonia in an ATP-dependent reaction. Here, we found higher expression of GLUL in the breast cancer patients was associated with larger tumor size and higher level of HER2 expression. In addition, GLUL was heterogeneously expressed in various breast cancer cells. The mRNA and protein expression levels of GLUL in SK-BR-3 cells were obviously higher than that in the other types of breast cancer cells. Results showed GLUL knockdown in SK-BR-3 cells could significantly decrease the proliferation ability. Furthermore, GLUL knockdown markedly inhibited the p38 MAPK and ERK1/ERK2 signaling pathways in SK-BR-3 cells. Thus, GLUL may represent a novel target for selectively inhibiting p38 MAPK and ERK1/ERK2 signaling pathways and the proliferation potential of breast cancer cells. This article is protected by copyright. All rights reserved.

  18. Immunology of Stem Cells and Cancer Stem Cells

    Institute of Scientific and Technical Information of China (English)

    Xiao-Feng Yang

    2007-01-01

    The capacity of pluri-potent stem cells to repair the tissues in which stem cells reside holds great promise in development of novel cell replacement therapeutics for treating chronic and degenerative diseases. However,numerous reports show that stem cell therapy, even in an autologous setting, triggers lymphocyte infiltration and inflammation. Therefore, an important question to be answered is how the host immune system responds to engrafted autologous stem cells or allogeneous stem cells. In this brief review, we summarize the progress in several related areas in this field, including some of our data, in four sections: (1) immunogenicity of stem cells; (2)strategies to inhibit immune rejection to allograft stem cells; (3) immune responses to cancer stem cells; and (4)mesenchymal stem cells in immune regulation. Improvement of our understanding on these and other aspects of immune system-stem cell interplay would greatly facilitate the development of stem cell-based therapeutics for regenerative purposes.

  19. Formaldehyde stimulates Mrp1-mediated glutathione deprivation of cultured astrocytes.

    Science.gov (United States)

    Tulpule, Ketki; Dringen, Ralf

    2011-02-01

    Formaldehyde (Fal) is an environmental neurotoxin that is also endogenously produced in brain. Since the tripeptide glutathione (GSH) plays an important role in detoxification processes in brain cells, we have investigated the consequences of a Fal exposure on the GSH metabolism of brain cells, using astrocyte-rich primary cultures as model system. Treatment of these cultures with Fal resulted in a rapid time- and concentration-dependent depletion of cellular GSH and a matching increase in the extracellular GSH content. Exposure of astrocytes to 1mm Fal for 3h did not compromise cell viability but almost completely deprived the cells of GSH. Half-maximal deprivation of cellular GSH was observed after application of 0.3mm Fal. This effect was rather specific for Fal, since methanol, formate or acetaldehyde did not affect cellular GSH levels. The Fal-stimulated GSH loss from viable astrocytes was completely prevented by semicarbazide-mediated chemical removal of Fal or by the application of MK571, an inhibitor of the multidrug resistance protein 1. These data demonstrate that Fal deprives astrocytes of cellular GSH by a multidrug resistance protein 1-mediated process.

  20. The indispensable roles of microglia and astrocytes during brain development

    NARCIS (Netherlands)

    Reemst, Kitty; Noctor, Stephen C.; Lucassen, Paul J.; Hol, Elly M.

    2016-01-01

    Glia are essential for brain functioning during development and in the adult brain. Here, we discuss the various roles of both microglia and astrocytes, and their interactions during brain development. Although both cells are fundamentally different in origin and function, they often affect the same

  1. Astrocytes and the evolution of the human brain.

    Science.gov (United States)

    Robertson, James M

    2014-02-01

    Cells within the astroglial lineage are proposed as the origin of human brain evolution. It is now widely accepted that they direct mammalian fetal neurogenesis, gliogenesis, laminar cytoarchitectonics, synaptic connectivity and neuronal network formation. Furthermore, genetic, anatomical and functional studies have recently identified multiple astrocyte exaptations that strongly suggest a direct relation to the increased size and complexity of the human brain.

  2. Loss of ATRX, associated with DNA methylation pattern of chromosome end, impacted biological behaviors of astrocytic tumors

    OpenAIRE

    CAI, JINQUAN; Chen, Jing; Zhang, Wei; Yang, Pei; Zhang, Chuanbao; Li, Mingyang; Yao, Kun; Wang, Hongjun; Li, Qingbin; Jiang, Chuanlu; Jiang., Tao

    2015-01-01

    Loss of ATRX leads to epigenetic alterations, including abnormal levels of DNA methylation at repetitive elements such as telomeres in murine cells. We conducted an extensive DNA methylation and mRNA expression profile study on a cohort of 82 patients with astrocytic tumors to study whether ATRX expression was associated with DNA methylation level in astrocytic tumors and in which cellular functions it participated. We observed that astrocytic tumors with lower ATRX expression harbored higher...

  3. Understanding spatial and temporal patterning of astrocyte calcium transients via interactions between network transport and extracellular diffusion

    Science.gov (United States)

    Shtrahman, E.; Maruyama, D.; Olariu, E.; Fink, C. G.; Zochowski, M.

    2017-02-01

    Astrocytes form interconnected networks in the brain and communicate via calcium signaling. We investigate how modes of coupling between astrocytes influence the spatio-temporal patterns of calcium signaling within astrocyte networks and specifically how these network interactions promote coordination within this group of cells. To investigate these complex phenomena, we study reduced cultured networks of astrocytes and neurons. We image the spatial temporal patterns of astrocyte calcium activity and quantify how perturbing the coupling between astrocytes influences astrocyte activity patterns. To gain insight into the pattern formation observed in these cultured networks, we compare the experimentally observed calcium activity patterns to the patterns produced by a reduced computational model, where we represent astrocytes as simple units that integrate input through two mechanisms: gap junction coupling (network transport) and chemical release (extracellular diffusion). We examine the activity patterns in the simulated astrocyte network and their dependence upon these two coupling mechanisms. We find that gap junctions and extracellular chemical release interact in astrocyte networks to modulate the spatiotemporal patterns of their calcium dynamics. We show agreement between the computational and experimental findings, which suggests that the complex global patterns can be understood as a result of simple local coupling mechanisms.

  4. Modulation of Pineal Melatonin Synthesis by Glutamate Involves Paracrine Interactions between Pinealocytes and Astrocytes through NF-κB Activation

    Directory of Open Access Journals (Sweden)

    Darine Villela

    2013-01-01

    Full Text Available The glutamatergic modulation of melatonin synthesis is well known, along with the importance of astrocytes in mediating glutamatergic signaling in the central nervous system. Pinealocytes and astrocytes are the main cell types in the pineal gland. The objective of this work was to investigate the interactions between astrocytes and pinealocytes as a part of the glutamate inhibitory effect on melatonin synthesis. Rat pinealocytes isolated or in coculture with astrocytes were incubated with glutamate in the presence of norepinephrine, and the melatonin content, was quantified. The expression of glutamate receptors, the intracellular calcium content and the NF-κB activation were analyzed in astrocytes and pinealocytes. TNF-α's possible mediation of the effect of glutamate was also investigated. The results showed that glutamate's inhibitory effect on melatonin synthesis involves interactions between astrocytes and pinealocytes, possibly through the release of TNF-α. Moreover, the activation of the astrocytic NF-κB seems to be a necessary step. In astrocytes and pinealocytes, AMPA, NMDA, and group I metabotropic glutamate receptors were observed, as well as the intracellular calcium elevation. In conclusion, there is evidence that the modulation of melatonin synthesis by glutamate involves paracrine interactions between pinealocytes and astrocytes through the activation of the astrocytic NF-κB transcription factor and possibly by subsequent TNF-α release.

  5. An update on the biology of cancer stem cells in breast cancer.

    Science.gov (United States)

    García Bueno, José María; Ocaña, Alberto; Castro-García, Paola; Gil Gas, Carmen; Sánchez-Sánchez, Francisco; Poblet, Enrique; Serrano, Rosario; Calero, Raúl; Ramírez-Castillejo, Carmen

    2008-12-01

    Breast cancer stem cells are defined as cancer cells with self-renewal capacity. These cells represent a small subpopulation endowed with the ability to form new tumours when injected in nude mice. Markers of differentiation have been used to identify these cancer cells. In the case of breast cancer, CD44+/CD24- select a population with stem cell properties. The fact that these cells have self-renewal ability has suggested that this population could be responsible for new tumour formation and cancer relapse. These cells have been shown to be more resistant to chemotherapy and radiotherapy than normal cancer cells. The identification of the molecular druggable alterations responsible for the initiation and maintenance of cancer stem cells is an important goal. In this article we will review all these points with special emphasis on the possible role of new drugs designed to interact with molecular pathways of cancer stem cells.

  6. Cancer stem cells and field cancerization of oral squamous cell carcinoma.

    Science.gov (United States)

    Simple, M; Suresh, Amritha; Das, Debashish; Kuriakose, Moni A

    2015-07-01

    Oral squamous cell carcinoma (OSCC) has a high propensity for local failure, which is attributed to recurrence at the primary site or the development of second primary tumors (SPT). Field cancerization that refers to the existence of transformed cells in areas adjacent to the primary tumor, has been attributed to be one of the probable reasons underlying disease relapse. The carcinogenic process necessitates multiple molecular events for the transformation of a normal cell into a cancer cell. This implies that only the long-time residents of the epithelium, such as the stem cells, might be the candidates capable of accumulating these genetic hits. These transformed stem cells- the 'Cancer stem cells' (CSCs), are further known to be equipped with the properties of tumor initiation and migration, both of which are essential for orchestrating field cancerization. The concept that the CSCs might be responsible for field cancerization in OSCC has not been explored extensively. If the role of CSCs as the primary units of field cancerization process is established, their presence in the mucosa adjacent to the tumor may be an indicator for local recurrence and/or development of second primary tumors. In this review, we examine the available evidence in literature exploring the possibilities of CSCs driving the process of field cancerization and thereby being the underlying mechanism for disease recurrence and development of SPT.

  7. What Is Kidney Cancer (Renal Cell Carcinoma)?

    Science.gov (United States)

    ... Treatment? Kidney Cancer About Kidney Cancer What Is Kidney Cancer? Kidney cancer is a cancer that starts ... and spread, see What Is Cancer? About the kidneys To understand more about kidney cancer, it helps ...

  8. Neuron to astrocyte communication via cannabinoid receptors is necessary for sustained epileptiform activity in rat hippocampus.

    Directory of Open Access Journals (Sweden)

    Guyllaume Coiret

    Full Text Available Astrocytes are integral functional components of synapses, regulating transmission and plasticity. They have also been implicated in the pathogenesis of epilepsy, although their precise roles have not been comprehensively characterized. Astrocytes integrate activity from neighboring synapses by responding to neuronally released neurotransmitters such as glutamate and ATP. Strong activation of astrocytes mediated by these neurotransmitters can promote seizure-like activity by initiating a positive feedback loop that induces excessive neuronal discharge. Recent work has demonstrated that astrocytes express cannabinoid 1 (CB1 receptors, which are sensitive to endocannabinoids released by nearby pyramidal cells. In this study, we tested whether this mechanism also contributes to epileptiform activity. In a model of 4-aminopyridine induced epileptic-like activity in hippocampal slice cultures, we show that pharmacological blockade of astrocyte CB1 receptors did not modify the initiation, but significantly reduced the maintenance of epileptiform discharge. When communication in astrocytic networks was disrupted by chelating astrocytic calcium, this CB1 receptor-mediated modulation of epileptiform activity was no longer observed. Thus, endocannabinoid signaling from neurons to astrocytes represents an additional significant factor in the maintenance of epileptiform activity in the hippocampus.

  9. In Vivo Evidence for a Lactate Gradient from Astrocytes to Neurons

    KAUST Repository

    Mächler, Philipp

    2015-11-19

    Investigating lactate dynamics in brain tissue is challenging, partly because in vivo data at cellular resolution are not available. We monitored lactate in cortical astrocytes and neurons of mice using the genetically encoded FRET sensor Laconic in combination with two-photon microscopy. An intravenous lactate injection rapidly increased the Laconic signal in both astrocytes and neurons, demonstrating high lactate permeability across tissue. The signal increase was significantly smaller in astrocytes, pointing to higher basal lactate levels in these cells, confirmed by a one-point calibration protocol. Trans-acceleration of the monocarboxylate transporter with pyruvate was able to reduce intracellular lactate in astrocytes but not in neurons. Collectively, these data provide in vivo evidence for a lactate gradient from astrocytes to neurons. This gradient is a prerequisite for a carrier-mediated lactate flux from astrocytes to neurons and thus supports the astrocyte-neuron lactate shuttle model, in which astrocyte-derived lactate acts as an energy substrate for neurons. © 2016 Elsevier Inc.

  10. Protein targeting to glycogen is a master regulator of glycogen synthesis in astrocytes

    KAUST Repository

    Ruchti, E.

    2016-10-08

    The storage and use of glycogen, the main energy reserve in the brain, is a metabolic feature of astrocytes. Glycogen synthesis is regulated by Protein Targeting to Glycogen (PTG), a member of specific glycogen-binding subunits of protein phosphatase-1 (PPP1). It positively regulates glycogen synthesis through de-phosphorylation of both glycogen synthase (activation) and glycogen phosphorylase (inactivation). In cultured astrocytes, PTG mRNA levels were previously shown to be enhanced by the neurotransmitter noradrenaline. To achieve further insight into the role of PTG in the regulation of astrocytic glycogen, its levels of expression were manipulated in primary cultures of mouse cortical astrocytes using adenovirus-mediated overexpression of tagged-PTG or siRNA to downregulate its expression. Infection of astrocytes with adenovirus led to a strong increase in PTG expression and was associated with massive glycogen accumulation (>100 fold), demonstrating that increased PTG expression is sufficient to induce glycogen synthesis and accumulation. In contrast, siRNA-mediated downregulation of PTG resulted in a 2-fold decrease in glycogen levels. Interestingly, PTG downregulation strongly impaired long-term astrocytic glycogen synthesis induced by insulin or noradrenaline. Finally, these effects of PTG downregulation on glycogen metabolism could also be observed in cultured astrocytes isolated from PTG-KO mice. Collectively, these observations point to a major role of PTG in the regulation of glycogen synthesis in astrocytes and indicate that conditions leading to changes in PTG expression will directly impact glycogen levels in this cell type.

  11. EF5 and Motexafin Lutetium in Detecting Tumor Cells in Patients With Abdominal or Non-Small Cell Lung Cancer

    Science.gov (United States)

    2013-01-15

    Advanced Adult Primary Liver Cancer; Carcinoma of the Appendix; Fallopian Tube Cancer; Gastrointestinal Stromal Tumor; Localized Extrahepatic Bile Duct Cancer; Localized Gallbladder Cancer; Localized Gastrointestinal Carcinoid Tumor; Localized Resectable Adult Primary Liver Cancer; Localized Unresectable Adult Primary Liver Cancer; Metastatic Gastrointestinal Carcinoid Tumor; Ovarian Sarcoma; Ovarian Stromal Cancer; Primary Peritoneal Cavity Cancer; Recurrent Adult Primary Liver Cancer; Recurrent Adult Soft Tissue Sarcoma; Recurrent Colon Cancer; Recurrent Extrahepatic Bile Duct Cancer; Recurrent Gallbladder Cancer; Recurrent Gastric Cancer; Recurrent Gastrointestinal Carcinoid Tumor; Recurrent Non-small Cell Lung Cancer; Recurrent Ovarian Epithelial Cancer; Recurrent Ovarian Germ Cell Tumor; Recurrent Pancreatic Cancer; Recurrent Rectal Cancer; Recurrent Small Intestine Cancer; Recurrent Uterine Sarcoma; Regional Gastrointestinal Carcinoid Tumor; Small Intestine Adenocarcinoma; Small Intestine Leiomyosarcoma; Small Intestine Lymphoma; Stage 0 Non-small Cell Lung Cancer; Stage I Adult Soft Tissue Sarcoma; Stage I Colon Cancer; Stage I Gastric Cancer; Stage I Non-small Cell Lung Cancer; Stage I Ovarian Epithelial Cancer; Stage I Ovarian Germ Cell Tumor; Stage I Pancreatic Cancer; Stage I Rectal Cancer; Stage I Uterine Sarcoma; Stage II Adult Soft Tissue Sarcoma; Stage II Colon Cancer; Stage II Gastric Cancer; Stage II Non-small Cell Lung Cancer; Stage II Ovarian Epithelial Cancer; Stage II Ovarian Germ Cell Tumor; Stage II Pancreatic Cancer; Stage II Rectal Cancer; Stage II Uterine Sarcoma; Stage III Adult Soft Tissue Sarcoma; Stage III Colon Cancer; Stage III Gastric Cancer; Stage III Ovarian Epithelial Cancer; Stage III Ovarian Germ Cell Tumor; Stage III Pancreatic Cancer; Stage III Rectal Cancer; Stage III Uterine Sarcoma; Stage IIIA Non-small Cell Lung Cancer; Stage IIIB Non-small Cell Lung Cancer; Stage IV Adult Soft Tissue Sarcoma; Stage IV Colon Cancer; Stage

  12. HIV-1 Entry and Trans-Infection of Astrocytes Involves CD81 Vesicles

    Science.gov (United States)

    Gray, Lachlan R.; Turville, Stuart G.; HItchen, Tina L.; Cheng, Wan-Jung; Ellett, Anne M.; Salimi, Hamid; Roche, Michael J.; Wesselingh, Steve L.; Gorry, Paul R.; Churchill, Melissa J.

    2014-01-01

    Astrocytes are extensively infected with HIV-1 in vivo and play a significant role in the development of HIV-1-associated neurocognitive disorders. Despite their extensive infection, little is known about how astrocytes become infected, since they lack cell surface CD4 expression. In the present study, we investigated the fate of HIV-1 upon infection of astrocytes. Astrocytes were found to bind and harbor virus followed by biphasic decay, with HIV-1 detectable out to 72 hours. HIV-1 was observed to associate with CD81-lined vesicle structures. shRNA silencing of CD81 resulted in less cell-associated virus but no loss of co-localization between HIV-1 and CD81. Astrocytes supported trans-infection of HIV-1 to T-cells without de novo virus production, and the virus-containing compartment required 37°C to form, and was trypsin-resistant. The CD81 compartment observed herein, has been shown in other cell types to be a relatively protective compartment. Within astrocytes, this compartment may be actively involved in virus entry and/or spread. The ability of astrocytes to transfer virus, without de novo viral synthesis suggests they are capable of sequestering and protecting virus and thus, they could potentially facilitate viral dissemination in the CNS. PMID:24587404

  13. Cancer Vaccine by Fusions of Dendritic and Cancer Cells

    Directory of Open Access Journals (Sweden)

    Shigeo Koido

    2009-01-01

    Full Text Available Dendritic cells (DCs are potent antigen-presenting cells and play a central role in the initiation and regulation of primary immune responses. Therefore, their use for the active immunotherapy against cancers has been studied with considerable interest. The fusion of DCs with whole tumor cells represents in many ways an ideal approach to deliver, process, and subsequently present a broad array of tumor-associated antigens, including those yet to be unidentified, in the context of DCs-derived costimulatory molecules. DCs/tumor fusion vaccine stimulates potent antitumor immunity in the animal tumor models. In the human studies, T cells stimulated by DC/tumor fusion cells are effective in lysis of tumor cells that are used as the fusion partner. In the clinical trials, clinical and immunological responses were observed in patients with advanced stage of malignant tumors after being vaccinated with DC/tumor fusion cells, although the antitumor effect is not as vigorous as in the animal tumor models. This review summarizes recent advances in concepts and techniques that are providing new impulses to DCs/tumor fusions-based cancer vaccination.

  14. Astrocyte cultures derived from human brain tissue express angiotensinogen mRNA

    Energy Technology Data Exchange (ETDEWEB)

    Milsted, A.; Barna, B.P.; Ransohoff, R.M.; Brosnihan, K.B.; Ferrario, C.M. (Cleveland Clinic Foundation, OH (USA))

    1990-08-01

    The authors have identified human cultured cell lines that are useful for studying angiotensinogen gene expression and its regulation in the central nervous system. A model cell system of human central nervous system origin expressing angiotensinogen has not previously been available. Expression of angiotensinogen mRNA appears to be a basal property of noninduced human astrocytes, since astrocytic cell lines derived from human glioblastomas or nonneoplastic human brain tissue invariably produced angiotensinogen mRNA. In situ hybridization histochemistry revealed that angiotensinogen mRNA production was not limited to a subpopulation of astrocytes because >99% of cells in these cultures contained angiotensinogen mRNA. These cell lines will be useful in studies of the molecular mechanisms controlling angiotensin synthesis and the role of biologically active angiotensin in the human brain by allowing the authors to examine regulation of expression of the renin-angiotensin system in human astrocyte cultures.

  15. Cancer Stem Cells and Pediatric Solid Tumors

    Directory of Open Access Journals (Sweden)

    Gregory K. Friedman

    2011-01-01

    Full Text Available Recently, a subpopulation of cells, termed tumor-initiating cells or tumor stem cells (TSC, has been identified in many different types of solid tumors. These TSC, which are typically more resistant to chemotherapy and radiation compared to other tumor cells, have properties similar to normal stem cells including multipotency and the ability to self-renew, proliferate, and maintain the neoplastic clone. Much of the research on TSC has focused on adult cancers. With considerable differences in tumor biology between adult and pediatric cancers, there may be significant differences in the presence, function and behavior of TSC in pediatric malignancies. We discuss what is currently known about pediatric solid TSC with specific focus on TSC markers, tumor microenvironment, signaling pathways, therapeutic resistance and potential future therapies to target pediatric TSC.

  16. Characterization of cancer stem-like cells in the side population cells of human gastric cancer cell line MKN-45

    Institute of Scientific and Technical Information of China (English)

    Hai-hong ZHANG; Ai-zhen CAI; Xue-ming WEI; Li DING; Feng-zhi LI; Ai-ming ZHENG; Da-jiang DAI

    2013-01-01

    Objective:Side population (SP) cells may play a crucial role in tumorigenesis and the recurrence of cancer.Many kinds of cell lines and tissues have demonstrated the presence of SP cells,including several gastric cancer cell lines.This study is aimed to identify the cancer stem-like cells in the SP of gastric cancer cell line MKN-45.Methods:We used fluorescence activated cell sorting (FACS) to sort SP cells in the human gastric carcinoma cell line MKN-45 (cells labeled with Hoechst 33342) and then characterized the cancer stem-like properties of SP cells.Results:This study found that the SP cells had higher clone formation efficiency than major population (MP) cells.Five stemness-related gene expression profiles,including OCT-4,SOX-2,NANOG,CD44,and adenosine triphosphate (ATP)-binding cassette transporters gene ABCG2,were tested in SP and MP cells using quantitative real-time reverse transcription polymerase chain reaction (RT-PCR).Western blot was used to show the difference of protein expression between SP and MP cells.Both results show that there was significantly higher protein expression in SP cells than in MP cells.When inoculated into non-obese diabetic/severe combined immunodeficiency (NOD/SCID) mice,SP cells show higher tumorigenesis tendency than MP cells.Conclusions:These results indicate that SP cells possess cancer stem cell properties and prove that SP cells from MKN-45 are gastric cancer stem-like cells.

  17. Cellular radiosensitivity of small-cell lung cancer cell lines

    DEFF Research Database (Denmark)

    Krarup, M; Poulsen, H S; Spang-Thomsen, M

    1997-01-01

    PURPOSE: The objective of this study was to determine the radiobiological characteristics of a panel of small-cell lung cancer (SCLC) cell lines by use of a clonogenic assay. In addition, we tested whether comparable results could be obtained by employing a growth extrapolation method based...

  18. Translational potential of cancer stem cells: A review of the detection of cancer stem cells and their roles in cancer recurrence and cancer treatment.

    Science.gov (United States)

    Islam, Farhadul; Gopalan, Vinod; Smith, Robert A; Lam, Alfred K-Y

    2015-07-01

    Cancer stem cells (CSCs) are a subpopulation of cancer cells with many clinical implications in most cancer types. One important clinical implication of CSCs is their role in cancer metastases, as reflected by their ability to initiate and drive micro and macro-metastases. The other important contributing factor for CSCs in cancer management is their function in causing treatment resistance and recurrence in cancer via their activation of different signalling pathways such as Notch, Wnt/β-catenin, TGF-β, Hedgehog, PI3K/Akt/mTOR and JAK/STAT pathways. Thus, many different therapeutic approaches are being tested for prevention and treatment of cancer recurrence. These may include treatment strategies targeting altered genetic signalling pathways by blocking specific cell surface molecules, altering the cancer microenvironments that nurture cancer stem cells, inducing differentiation of CSCs, immunotherapy based on CSCs associated antigens, exploiting metabolites to kill CSCs, and designing small interfering RNA/DNA molecules that especially target CSCs. Because of the huge potential of these approaches to improve cancer management, it is important to identify and isolate cancer stem cells for precise study and application of prior the research on their role in cancer. Commonly used methodologies for detection and isolation of CSCs include functional, image-based, molecular, cytological sorting and filtration approaches, the use of different surface markers and xenotransplantation. Overall, given their significance in cancer biology, refining the isolation and targeting of CSCs will play an important role in future management of cancer.

  19. Molecular Pathways: Reactive Oxygen Species Homeostasis in Cancer Cells and Implications for Cancer Therapy

    OpenAIRE

    Nogueira, Veronique; Hay, Nissim

    2013-01-01

    Reactive oxygen species (ROS) are important in regulating normal cellular processes, but deregulated ROS contribute to the development of various human diseases including cancers. Cancer cells have increased ROS levels compared to normal cells, because of their accelerated metabolism. The high ROS levels in cancer cells, which distinguish them from normal cells, could be pro-tumorigenic, but are also their Achilles’ heel. The high ROS content in cancer cells renders them more susceptible to o...

  20. Cancer Cell Colonisation in the Bone Microenvironment

    Directory of Open Access Journals (Sweden)

    Casina Kan

    2016-10-01

    Full Text Available Bone metastases are a common complication of epithelial cancers, of which breast, prostate and lung carcinomas are the most common. The establishment of cancer cells to distant sites such as the bone microenvironment requires multiple steps. Tumour cells can acquire properties to allow epithelial-to-mesenchymal transition, extravasation and migration. Within the bone metastatic niche, disseminated tumour cells may enter a dormancy stage or proliferate to adapt and survive, interacting with bone cells such as hematopoietic stem cells, osteoblasts and osteoclasts. Cross-talk with the bone may alter tumour cell properties and, conversely, tumour cells may also acquire characteristics of the surrounding microenvironment, in a process known as osteomimicry. Alternatively, these cells may also express osteomimetic genes that allow cell survival or favour seeding to the bone marrow. The seeding of tumour cells in the bone disrupts bone-forming and bone-resorbing activities, which can lead to macrometastasis in bone. At present, bone macrometastases are incurable with only palliative treatment available. A better understanding of how these processes influence the early onset of bone metastasis may give insight into potential therapies. This review will focus on the early steps of bone colonisation, once disseminated tumour cells enter the bone marrow.

  1. Understanding cancer stem cell heterogeneity and plasticity

    Institute of Scientific and Technical Information of China (English)

    Dean G Tang

    2012-01-01

    Heterogeneity is an omnipresent feature of mammalian cells in vitro and in vivo.It has been recently realized that even mouse and human embryonic stem cells under the best culture conditions are heterogeneous containing pluripotent as well as partially committed cells.Somatic stem cells in adult organs are also heterogeneous,containing many subpopulations of self-renewing cells with distinct regenerative capacity.The differentiated progeny of adult stem cells also retain significant developmental plasticity that can be induced by a wide variety of experimental approaches.Like normal stem cells,recent data suggest that cancer stem cells(CSCs)similarly display significant phenotypic and functional heterogeneity,and that the CSC progeny can manifest diverse plasticity.Here,I discuss CSC heterogeneity and plasticity in the context of tumor development and progression,and by comparing with normal stem cell development.Appreciation of cancer cell plasticity entails a revision to the earlier concept that only the tumorigenic subset in the tumor needs to be targeted.By understanding the interrelationship between CSCs and their differentiated progeny,we can hope to develop better therapeutic regimens that can prevent the emergence of tumor cell variants that are able to found a new tumor and distant metastases.

  2. Cancer Cell Colonisation in the Bone Microenvironment

    Science.gov (United States)

    Kan, Casina; Vargas, Geoffrey; Le Pape, François; Clézardin, Philippe

    2016-01-01

    Bone metastases are a common complication of epithelial cancers, of which breast, prostate and lung carcinomas are the most common. The establishment of cancer cells to distant sites such as the bone microenvironment requires multiple steps. Tumour cells can acquire properties to allow epithelial-to-mesenchymal transition, extravasation and migration. Within the bone metastatic niche, disseminated tumour cells may enter a dormancy stage or proliferate to adapt and survive, interacting with bone cells such as hematopoietic stem cells, osteoblasts and osteoclasts. Cross-talk with the bone may alter tumour cell properties and, conversely, tumour cells may also acquire characteristics of the surrounding microenvironment, in a process known as osteomimicry. Alternatively, these cells may also express osteomimetic genes that allow cell survival or favour seeding to the bone marrow. The seeding of tumour cells in the bone disrupts bone-forming and bone-resorbing activities, which can lead to macrometastasis in bone. At present, bone macrometastases are incurable with only palliative treatment available. A better understanding of how these processes influence the early onset of bone metastasis may give insight into potential therapies. This review will focus on the early steps of bone colonisation, once disseminated tumour cells enter the bone marrow. PMID:27782035

  3. Targeting cancer stem cells in hepatocellular carcinoma

    Directory of Open Access Journals (Sweden)

    He AR

    2014-12-01

    Full Text Available Aiwu Ruth He,1 Daniel C Smith,1 Lopa Mishra2 1Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC, 2Department of Gastroenterology, Hepatology, and Nutrition, The University of Texas MD Anderson Cancer Center, Houston, TX, USA Abstract: The poor outcome of patients with hepatocellular carcinoma (HCC is attributed to recurrence of the disease after curative treatment and the resistance of HCC cells to conventional chemotherapy, which may be explained partly by the function of liver cancer stem cells (CSCs. Liver CSCs have emerged as an important therapeutic target against HCC. Numerous surface markers for liver CSCs have been identified, and include CD133, CD90, CD44, CD13, and epithelial cell adhesion molecules. These surface markers serve not only as tools for identifying and isolating liver CSCs but also as therapeutic targets for eradicating these cells. In studies of animal models and large-scale genomic analyses of human HCC samples, many signaling pathways observed in normal stem cells have been found to be altered in liver CSCs, which accounts for the stemness and aggressive behavior of these cells. Antibodies and small molecule inhibitors targeting the signaling pathways have been evaluated at different levels of preclinical and clinical development. Another strategy is to promote the differentiation of liver CSCs to less aggressive HCC that is sensitive to conventional chemotherapy. Disruption of the tumor niche essential for liver CSC homeostasis has become a novel strategy in cancer treatment. To overcome the challenges in developing treatment for liver CSCs, more research into the genetic makeup of patient tumors that respond to treatment may lead to more effective therapy. Standardization of HCC CSC tumor markers would be helpful for measuring the CSC response to these agents. Herein, we review the current strategies for developing treatment to eradicate liver CSCs and to improve the outcome for patients with

  4. Population genetics of cancer cell clones: possible implications of cancer stem cells

    Directory of Open Access Journals (Sweden)

    Naugler Christopher T

    2010-11-01

    Full Text Available Abstract Background The population dynamics of the various clones of cancer cells existing within a tumour is complex and still poorly understood. Cancer cell clones can be conceptualized as sympatric asexual species, and as such, the application of theoretical population genetics as it pertains to asexual species may provide additional insights. Results The number of generations of tumour cells within a cancer has been estimated at a minimum of 40, but high cancer cell mortality rates suggest that the number of cell generations may actually be in the hundreds. Such a large number of generations would easily allow natural selection to drive clonal evolution assuming that selective advantages of individual clones are within the range reported for free-living animal species. Tumour cell clonal evolution could also be driven by variation in the intrinsic rates of increase of different clones or by genetic drift. In every scenario examined, the presence of cancer stem cells would require lower selection pressure or less variation in intrinsic rates of increase. Conclusions The presence of cancer stem cells may result in more rapid clonal evolution. Specific predictions from theoretical population genetics may lead to a greater understanding of this process.

  5. Cell membrane softening in human breast and cervical cancer cells

    Science.gov (United States)

    Händel, Chris; Schmidt, B. U. Sebastian; Schiller, Jürgen; Dietrich, Undine; Möhn, Till; Kießling, Tobias R.; Pawlizak, Steve; Fritsch, Anatol W.; Horn, Lars-Christian; Briest, Susanne; Höckel, Michael; Zink, Mareike; Käs, Josef A.

    2015-08-01

    Biomechanical properties are key to many cellular functions such as cell division and cell motility and thus are crucial in the development and understanding of several diseases, for instance cancer. The mechanics of the cellular cytoskeleton have been extensively characterized in cells and artificial systems. The rigidity of the plasma membrane, with the exception of red blood cells, is unknown and membrane rigidity measurements only exist for vesicles composed of a few synthetic lipids. In this study, thermal fluctuations of giant plasma membrane vesicles (GPMVs) directly derived from the plasma membranes of primary breast and cervical cells, as well as breast cell lines, are analyzed. Cell blebs or GPMVs were studied via thermal membrane fluctuations and mass spectrometry. It will be shown that cancer cell membranes are significantly softer than their non-malignant counterparts. This can be attributed to a loss of fluid raft forming lipids in malignant cells. These results indicate that the reduction of membrane rigidity promotes aggressive blebbing motion in invasive cancer cells.

  6. Drug treatment of cancer cell lines: a way to select for cancer stem cells?

    Science.gov (United States)

    Chiodi, Ilaria; Belgiovine, Cristina; Donà, Francesca; Scovassi, A Ivana; Mondello, Chiara

    2011-03-04

    Tumors are generally composed of different cell types. In recent years, it has been shown that in many types of cancers a subset of cells show peculiar characteristics, such as the ability to induce tumors when engrafted into host animals, self-renew and being immortal, and give rise to a differentiated progeny. These cells have been defined as cancer stem cells (CSCs) or tumor initiating cells. CSCs can be isolated both from tumor specimens and established cancer cell lines on the basis of their ability to exclude fluorescent dyes, express specific cell surface markers or grow in particular culture conditions. A key feature of CSCs is their resistance to chemotherapeutic agents, which could contribute to the remaining of residual cancer cells after therapeutic treatments. It has been shown that CSC-like cells can be isolated after drug treatment of cancer cell lines; in this review, we will describe the strategies so far applied to identify and isolate CSCs. Furthermore, we will discuss the possible use of these selected populations to investigate CSC biology and develop new anticancer drugs.

  7. Drug Treatment of Cancer Cell Lines: A Way to Select for Cancer Stem Cells?

    Directory of Open Access Journals (Sweden)

    Ilaria Chiodi

    2011-03-01

    Full Text Available Tumors are generally composed of different cell types. In recent years, it has been shown that in many types of cancers a subset of cells show peculiar characteristics, such as the ability to induce tumors when engrafted into host animals, self-renew and being immortal, and give rise to a differentiated progeny. These cells have been defined as cancer stem cells (CSCs or tumor initiating cells. CSCs can be isolated both from tumor specimens and established cancer cell lines on the basis of their ability to exclude fluorescent dyes, express specific cell surface markers or grow in particular culture conditions. A key feature of CSCs is their resistance to chemotherapeutic agents, which could contribute to the remaining of residual cancer cells after therapeutic treatments. It has been shown that CSC-like cells can be isolated after drug treatment of cancer cell lines; in this review, we will describe the strategies so far applied to identify and isolate CSCs. Furthermore, we will discuss the possible use of these selected populations to investigate CSC biology and develop new anticancer drugs.

  8. Drug Treatment of Cancer Cell Lines: A Way to Select for Cancer Stem Cells?

    Energy Technology Data Exchange (ETDEWEB)

    Chiodi, Ilaria; Belgiovine, Cristina; Donà, Francesca; Scovassi, A. Ivana; Mondello, Chiara, E-mail: mondello@igm.cnr.it [Institute of Molecular Genetics, CNR, via Abbiategrasso 207, 27100 Pavia (Italy)

    2011-03-04

    Tumors are generally composed of different cell types. In recent years, it has been shown that in many types of cancers a subset of cells show peculiar characteristics, such as the ability to induce tumors when engrafted into host animals, self-renew and being immortal, and give rise to a differentiated progeny. These cells have been defined as cancer stem cells (CSCs) or tumor initiating cells. CSCs can be isolated both from tumor specimens and established cancer cell lines on the basis of their ability to exclude fluorescent dyes, express specific cell surface markers or grow in particular culture conditions. A key feature of CSCs is their resistance to chemotherapeutic agents, which could contribute to the remaining of residual cancer cells after therapeutic treatments. It has been shown that CSC-like cells can be isolated after drug treatment of cancer cell lines; in this review, we will describe the strategies so far applied to identify and isolate CSCs. Furthermore, we will discuss the possible use of these selected populations to investigate CSC biology and develop new anticancer drugs.

  9. Astrocyte signaling in the presence of spatial inhomogeneities

    Science.gov (United States)

    Stamatakis, Michail; Mantzaris, Nikos V.

    2007-09-01

    Astrocytes, a special type of glial cells, were considered to have just a supporting role in information processing in the brain. However, several recent studies have shown that they can be chemically stimulated by various neurotransmitters, such as ATP, and can generate Ca2+ and ATP waves, which can propagate over many cell lengths before being blocked. Although pathological conditions, such as spreading depression and epilepsy, have been linked to abnormal wave propagation in astrocytic cellular networks, a quantitative understanding of the underlying characteristics is still lacking. Astrocytic cellular networks are inhomogeneous, in the sense that the domain they occupy contains passive regions or gaps, which are unable to support wave propagation. Thus, this work focuses on understanding the complex interplay between single-cell signal transduction, domain inhomogeneity, and the characteristics of wave propagation and blocking in astrocytic cellular networks. The single-cell signal transduction model that was employed accounts for ATP-mediated IP3 production, the subsequent Ca2+ release from the ER, and ATP release into the extracellular space. The model is excitable and thus an infinite range of wave propagation is observed if the domain of propagation is homogeneous. This is not always the case for inhomogeneous domains. To model wave propagation in inhomogeneous astrocytic networks, a reaction-diffusion framework was developed and one-gap as well as multiple-gap cases were simulated using an efficient finite-element algorithm. The minimum gap length that blocks the wave was computed as a function of excitability levels and geometric characteristics of the inhomogeneous network, such as the length of the active regions (cells). Complex transient patterns, such as wave reflection, wave trapping, and generation of echo waves, were also predicted by the model, and their relationship to the geometric characteristics of the network was evaluated. Therefore, the

  10. α7 Nicotinic Receptor Promotes the Neuroprotective Functions of Astrocytes against Oxaliplatin Neurotoxicity

    Directory of Open Access Journals (Sweden)

    Lorenzo Di Cesare Mannelli

    2015-01-01

    Full Text Available Neuropathies are characterized by a complex response of the central nervous system to injuries. Glial cells are recruited to maintain neuronal homeostasis but dysregulated activation leads to pain signaling amplification and reduces the glial neuroprotective power. Recently, we highlighted the property of α7 nicotinic-acetylcholine-receptor (nAChR agonists to relieve pain and induce neuroprotection simultaneously with a strong increase in astrocyte density. Aimed to study the role of α7 nAChR in the neuron-glia cross-talk, we treated primary rat neurons and astrocytes with the neurotoxic anticancer drug oxaliplatin evaluating the effect of the α7 nAChR agonist PNU-282987 (PNU. Oxaliplatin (1 μM, 48 h reduced cell viability and increased caspase-3 activity of neuron monocultures without damaging astrocytes. In cocultures, astrocytes were not able to protect neurons by oxaliplatin even if glial cell metabolism was stimulated (pyruvate increase. On the contrary, the coculture incubation with 10 μM PNU improved neuron viability and inhibited apoptosis. In the absence of astrocytes, the protection disappeared. Furthermore, PNU promoted the release of the anti-inflammatory cytokine TGF-β1 and the expression of the glutamate-detoxifying enzyme glutamine synthetase. The α7 nAChR stimulation protects neurons from oxaliplatin toxicity through an astrocyte-mediated mechanism. α7 nAChR is suggested for recovering the homeostatic role of astrocytes.

  11. Ketogenic diet and astrocyte/neuron metabolic interactions

    Directory of Open Access Journals (Sweden)

    Vamecq Joseph

    2007-05-01

    Full Text Available The ketogenic diet is an anticonvulsant diet enriched in fat. It provides the body with a minimal protein requirement and a restricted carbohydrate supply, the vast majority of calories (more than 80-90% being given by fat. Though anticonvulsant activity of ketogenic diet has been well documented by a large number of experimental and clinical studies, underlying mechanisms still remain partially unclear. Astrocyte-neuron interactions, among which metabolic shuttles, may influence synaptic activity and hence anticonvulsant protection. The astrocyte-neuron metabolic shuttles may be themselves influenced by the availability in energetic substrates such as hydrates of carbon and fats. Historically, ketogenic diet had been designed to mimic changes such as ketosis occurring upon starvation, a physiological state already known to exhibit anticonvulsant protection and sometimes referred to as “water diet”. For this reason, a special attention should be paid to metabolic features shared in common by ketogenic diet and starvation and especially those features that might result in anticonvulsant protection. Compared to feeding by usual mixed diet, starvation and ketogenic diet are both characterised by increased fat, lowered glucose and aminoacid supplies to cells. The resulting impact of these changes in energetic substrates on astrocyte/neuron metabolic shuttles might have anticonvulsant and/or neuroprotective properties. This is the aim of this communication to review some important astrocyte/neuron metabolic interactions (astrocyte/neuron lactate shuttle, glutamateinduced astrocytic glycolysis activation, glutamate/glutamine cycle along with the neurovascular coupling and the extent to which the way of their alteration by starvation and/or ketogenic diet might result in seizure and/or brain protection.

  12. Vasculogenic mimicry in small cell lung cancer.

    Science.gov (United States)

    Williamson, Stuart C; Metcalf, Robert L; Trapani, Francesca; Mohan, Sumitra; Antonello, Jenny; Abbott, Benjamin; Leong, Hui Sun; Chester, Christopher P E; Simms, Nicole; Polanski, Radoslaw; Nonaka, Daisuke; Priest, Lynsey; Fusi, Alberto; Carlsson, Fredrika; Carlsson, Anders; Hendrix, Mary J C; Seftor, Richard E B; Seftor, Elisabeth A; Rothwell, Dominic G; Hughes, Andrew; Hicks, James; Miller, Crispin; Kuhn, Peter; Brady, Ged; Simpson, Kathryn L; Blackhall, Fiona H; Dive, Caroline

    2016-11-09

    Small cell lung cancer (SCLC) is characterized by prevalent circulating tumour cells (CTCs), early metastasis and poor prognosis. We show that SCLC patients (37/38) have rare CTC subpopulations co-expressing vascular endothelial-cadherin (VE-cadherin) and cytokeratins consistent with vasculogenic mimicry (VM), a process whereby tumour cells form 'endothelial-like' vessels. Single-cell genomic analysis reveals characteristic SCLC genomic changes in both VE-cadherin-positive and -negative CTCs. Higher levels of VM are associated with worse overall survival in 41 limited-stage patients' biopsies (Pcisplatin efficacy. The functional significance of VM in SCLC suggests VM regulation may provide new targets for therapeutic intervention.

  13. Expression of Cyclooxygenase-2 in Ovarian Cancer Cell Lines

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    To investigate the expression of cyclooxygenase-2 (COX-2) in ovarian cancer cell lines,RT-PCR and immunocytochemistry were used to detect the expression of COX-2 in 5 ovarian cancer cell lines. The expression of COX-2 mRNA and protein was detected in all 5 cell lines. It is suggested that COX-2 is expressed in ovarian cancer cell lines, which provides a basis for the chemoprevention of ovarian cancer.

  14. Circulating Tumor Cells in Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Brian [Institute of Urology, University of Southern California, 1441 Eastlake Avenue, Suite 7416, Los Angeles, CA 90033 (United States); Rochefort, Holly [Department of Surgery, University of Southern California, 1520 San Pablo Street, HCT 4300, Los Angeles, CA 90033 (United States); Goldkorn, Amir, E-mail: agoldkor@usc.edu [Department of Internal Medicine and Norris Comprehensive Cancer Center, University of Southern California Keck School of Medicine, 1441 Eastlake Avenue, Suite 3440, Los Angeles, CA 90033 (United States)

    2013-12-04

    Circulating tumor cells (CTCs) can provide a non-invasive, repeatable snapshot of an individual patient’s tumor. In prostate cancer, CTC enumeration has been extensively studied and validated as a prognostic tool and has received FDA clearance for use in monitoring advanced disease. More recently, CTC analysis has been shifting from enumeration to more sophisticated molecular characterization of captured cells, which serve as a “liquid biopsy” of the tumor, reflecting molecular changes in an individual’s malignancy over time. Here we will review the main CTC studies in advanced and localized prostate cancer, highlighting the important gains as well as the challenges posed by various approaches, and their implications for advancing prostate cancer management.

  15. Circulating Tumor Cells in Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Brian Hu

    2013-12-01

    Full Text Available Circulating tumor cells (CTCs can provide a non-invasive, repeatable snapshot of an individual patient’s tumor. In prostate cancer, CTC enumeration has been extensively studied and validated as a prognostic tool and has received FDA clearance for use in monitoring advanced disease. More recently, CTC analysis has been shifting from enumeration to more sophisticated molecular characterization of captured cells, which serve as a “liquid biopsy” of the tumor, reflecting molecular changes in an individual’s malignancy over time. Here we will review the main CTC studies in advanced and localized prostate cancer, highlighting the important gains as well as the challenges posed by various approaches, and their implications for advancing prostate cancer management.

  16. Antofine-induced connexin43 gap junction disassembly in rat astrocytes involves protein kinase Cβ.

    Science.gov (United States)

    Huang, Yu-Fang; Liao, Chih-Kai; Lin, Jau-Chen; Jow, Guey-Mei; Wang, Hwai-Shi; Wu, Jiahn-Chun

    2013-03-01

    Antofine, a phenanthroindolizidine alkaloid derived from Cryptocaryachinensis and Ficusseptica in the Asclepiadaceae milkweed family, is cytotoxic for various cancer cell lines. In this study, we demonstrated that treatment of rat primary astrocytes with antofine induced dose-dependent inhibition of gap junction intercellular communication (GJIC), as assessed by scrape-loading 6-carboxyfluorescein dye transfer. Levels of Cx43 protein were also decreased in a dose- and time-dependent manner following antofine treatment. Double-labeling immunofluorescence microscopy showed that antofine (10ng/ml) induced endocytosis of surface gap junctions into the cytoplasm, where Cx43 was co-localized with the early endosome marker EEA1. Inhibition of lysosomes or proteasomes by co-treatment with antofine and their respective specific inhibitors, NH4Cl or MG132, partially inhibited the antofine-induced decrease in Cx43 protein levels, but did not inhibit the antofine-induced inhibition of GJIC. After 30min of treatment, antofine induced a rapid increase in the intracellular Ca(2+) concentration and activation of protein kinase C (PKC)α/βII, which was maintained for at least 6h. Co-treatment of astrocytes with antofine and the intracellular Ca(2+) chelator BAPTA-AM prevented downregulation of Cx43 and inhibition of GJIC. Moreover, co-treatment with antofine and a specific PKCβ inhibitor prevented endocytosis of gap junctions, downregulation of Cx43, and inhibition of GJIC. Taken together, these findings indicate that antofine induces Cx43 gap junction disassembly by the PKCβ signaling pathway. Inhibition of GJIC by antofine may undermine the neuroprotective effect of astrocytes in CNS.

  17. Ciprofloxacin mediates cancer stem cell phenotypes in lung cancer cells through caveolin-1-dependent mechanism.

    Science.gov (United States)

    Phiboonchaiyanan, Preeyaporn Plaim