Glial Cells Modulate Retinal Cell Survival in Rotenone-Induced Neural Degeneration

Abstract Administration of the mitochondrial complex I inhibitor rotenone provides an excellent model to study the pathomechanism of oxidative stress-related neural degeneration diseases. In this study, we examined the glial roles in retinal cell survival and degeneration under the rotenone-induced oxidative stress condition. Mouse-derived Müller, microglial (BV-2), and dissociated retinal cells were used for in vitro experiments. Gene expression levels and cell viability were determined using quantitative reverse transcription-polymerase chain reaction and the alamarBlue assay, respectively. Conditioned media were prepared by stimulating glial cells with rotenone. Retinal ganglion cells (RGCs) and inner nuclear layer (INL) were visualized on rat retinal sections by immunohistochemistry and eosin/hematoxylin, respectively. Rotenone dose-dependently induced glial cell death. Treatment with rotenone or rotenone-stimulated glial cell-conditioned media altered gene expression of growth factors and inflammatory cytokines in glial cells. The viability of dissociated retinal cells significantly increased upon culturing in media conditioned with rotenone-stimulated or Müller cell-conditioned media-stimulated BV-2 cells. Furthermore, intravitreal neurotrophin-5 administration prevented the rotenone-induced reduction of RGC number and INL thickness in rats. Thus, glial cells exerted both positive and negative effects on retinal cell survival in rotenone-induced neural degeneration via altered expression of growth factors, especially upregulation of microglia-derived Ntf5, and proinflammatory cytokines.

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Glial cells modulate retinal cell survival in rotenone-induced neural degeneration

Scientific Reports ◽

10.1038/s41598-021-90604-w ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Hiroshi Tawarayama ◽

Maki Inoue-Yanagimachi ◽

Noriko Himori ◽

Toru Nakazawa

Keyword(s):

Oxidative Stress ◽

Gene Expression ◽

Growth Factors ◽

Cell Survival ◽

Glial Cell ◽

Glial Cells ◽

Conditioned Media ◽

Retinal Cell ◽

Retinal Cells ◽

Neural Degeneration

AbstractAdministration of the mitochondrial complex I inhibitor rotenone provides an excellent model to study the pathomechanism of oxidative stress-related neural degeneration diseases. In this study, we examined the glial roles in retinal cell survival and degeneration under the rotenone-induced oxidative stress condition. Mouse-derived Müller, microglial (BV-2), and dissociated retinal cells were used for in vitro experiments. Gene expression levels and cell viability were determined using quantitative reverse transcription-polymerase chain reaction and the alamarBlue assay, respectively. Conditioned media were prepared by stimulating glial cells with rotenone. Retinal ganglion cells (RGCs) and inner nuclear layer (INL) were visualized on rat retinal sections by immunohistochemistry and eosin/hematoxylin, respectively. Rotenone dose-dependently induced glial cell death. Treatment with rotenone or rotenone-stimulated glial cell-conditioned media altered gene expression of growth factors and inflammatory cytokines in glial cells. The viability of dissociated retinal cells significantly increased upon culturing in media conditioned with rotenone-stimulated or Müller cell-conditioned media-stimulated BV-2 cells. Furthermore, intravitreal neurotrophin-5 administration prevented the rotenone-induced reduction of RGC number and INL thickness in rats. Thus, glial cells exerted both positive and negative effects on retinal cell survival in rotenone-induced neural degeneration via altered expression of growth factors, especially upregulation of microglia-derived Ntf5, and proinflammatory cytokines.

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Co-Culture of Myeloma and Endothelial Cells: Defibrotide Downregulates Heparanase and Pro-Angiogenic Growth Factors.

Blood ◽

10.1182/blood.v110.11.2513.2513 ◽

2007 ◽

Vol 110 (11) ◽

pp. 2513-2513 ◽

Cited By ~ 1

Author(s):

Cinara Echart ◽

Maria Distaso ◽

Laura Ferro ◽

Mario Boccadoro ◽

Antonio Palumbo ◽

...

Keyword(s):

Gene Expression ◽

Endothelial Cells ◽

Growth Factors ◽

Growth Factor ◽

Conditioned Media ◽

Angiogenic Growth Factors ◽

Factor Expression ◽

Key Factor ◽

Growth Factor Expression ◽

Rpmi 8226

Abstract Introduction: Heparanase (HPSE) expression in humans has been associated with advanced progression and metastasis of many tumor types, including multiple myeloma (MM), where its activity is correlated with altered gene expression that may promote an aggressive tumor phenotype with high microvessel density (ref). These findings indicate an important role of HPSE in regulating metastasis, angiogenesis and progression of MM. Defibrotide (DF) is an orally bio-available polydisperse oligonucleotide with anti-thrombotic, pro-fibrinolytic, anti-adhesive and anti-angiogenic properties. Recently, we have shown that DF is able to downregulate HPSE gene expression and activity in MM cell lines (International myeloma workshop, Greece, 2007). Methods: We investigated whether the expression of HPSE and angiogenic growth factors (FGF-2 and VEGF) in human microvascular endothelial cells (HMEC) are modified by co-culture with MM cells or by growing in the media of MM cells. In addition, we evaluated whether DF has activity in regulating the expression of HPSE, FGF-2 and VEGF in HMEC co-cultured with MM cells. We then tested the effect of DF on the invasiveness of MM cells activated with HPSE. HMEC cells were co-cultured with RPMI 8226 MM cells for 48h in the presence and absence of DF (at dose of 150μg/ml). HMEC was also grown alone for 48h in MM cell-conditioned media. The expression of HPSE and angiogenic growth factors (FGF-2 and VEGF) present in endothelial cells were examined through real time polymerase chain reaction (RT-PCR) of cDNA prepared from HMEC. Tumor invasion was evaluated using the BD BioCoat MatrigelTM invasion system (BD Bioscience). Results: Coculture with RPMI 8226 cells substantially induced the expression of HPSE (7.2 fold) and angiogenic growth factors (3-5 fold) in HMEC compared with endothelial cells growing alone. DF was able to downregulate HPSE, FGF-2 and VEGF gene expression in HMEC co-cultured with RPMI 8226 cells (4.0; 6.0-8.0 fold, respectively). Surprisingly, addition of conditioned media in absence of MM cells resulted in 6.5 fold of elevation of HPSE but not growth factors expression in HMEC. These results show that components released by MM cells are sufficient to modulate HPSE. However, to alter growth factor expression, HMEC needed to be culture in the presence of RPMI 8226 cells. Additionally, HPSE increased the invasiveness of RPMI 8226 cells and DF was able to significantly decrease MM invasiveness in the Matrigel assay by 50% (p<0.05). Conclusion: Taken together, these results suggest that cross-talk between MM and endothelial cells leads to enhanced angiogenesis. HPSE is a key factor in this process, correlating with both angiogenic stimulus and MM progression. Moreover, DF is able to downregulate HSPE and growth factor expression in activated HMEC induced by MM, as well as reducing the invasiveness of MM in this system. These observations suggest a potent potential anti-tumor effect of DF and support further preclinical evaluation in MM models as well as ongoing clinical studies in this setting.

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Oxytocin Promotes C6 Glial Cell Death and Aggravates Hydrogen Peroxide-induced Oxidative Stress

10.36922/itps.v3i1.939 ◽

2020 ◽

pp. 27-33

Author(s):

Ahmet Sevki Taskiran ◽

Merve Ergul

Keyword(s):

Oxidative Stress ◽

Hydrogen Peroxide ◽

Cell Death ◽

Cell Viability ◽

Glial Cell ◽

Glial Cells ◽

Control Group ◽

C6 Cells ◽

Cox 2 ◽

Cox 1

Background. Recent studies have shown that oxytocin plays a vital role in neurons and glial cells. However, its effect on hydrogen peroxide (H2O2)-induced oxidative stress as well as cyclooxygenase-1 (COX-1) and COX-2 in glial cells are still unclear. Objective. This study aims to examine the effect of oxytocin on glial cell viability, oxidative stress, COX-1, and COX-2 in C6 glial cells after exposure to H2O2. Methods. In this study, C6 glioma cell line was used to study the effect of oxytocin on the glial cell in four cell groups. The control group was untreated. Cells in the H2O2 group were treated with 0.5 mM H2O2 for 24 h. Cells in the oxytocin group were treated with various concentrations (0.25, 0.5, 1, and 2 μg/mL) of oxytocin for 24 h. Cells in the oxytocin+H2O2 group were pre-treated with various concentrations (0.25, 0.5, 1, and 2 μg/mL) of oxytocin for 1 h before 24-h exposure to 0.5 mM H2O2. Cell viability was evaluated using XTT assay. Total antioxidant status and total oxidant status (TOS), COX-1, and COX-2 levels in the cells were measured by commercial kits. Results. Oxytocin with various concentrations significantly decreased the viability of C6 cells after H2O2-induced oxidative stress (P < 0.01). It also significantly increased the levels of TOS, COX-1, and COX-2 in C6 cells after H2O2-induced oxidative stress (P < 0.001). Conclusion. Oxytocin increases glial cell death after H2O2-induced oxidative damage in C6 cells, along with upregulation of COX-1 and COX-2 levels.

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Celastrol and Melatonin Modify SIRT1, SIRT6 and SIRT7 Gene Expression and Improve the Response of Human Granulosa-Lutein Cells to Oxidative Stress

Antioxidants ◽

10.3390/antiox10121871 ◽

2021 ◽

Vol 10 (12) ◽

pp. 1871

Author(s):

Rita Martín-Ramírez ◽

Rebeca González-Fernández ◽

Jairo Hernández ◽

Pablo Martín-Vasallo ◽

Angela Palumbo ◽

...

Keyword(s):

Oxidative Stress ◽

Gene Expression ◽

Free Radical ◽

Cell Survival ◽

Direct Effect ◽

Free Radical Scavenger ◽

Radical Scavenger ◽

Protective Agent ◽

Physiological Processes

An excess of oxidative stress (OS) may affect several physiological processes fundamental to reproduction. SIRT1, SIRT6 and SIRT7 are involved in protection stress systems caused by OS, and they can be activated by antioxidants such as celastrol or melatonin. In this study, we evaluate SIRT1, SIRT6 and SIRT7 gene expression in cultured human granulosa-lutein (hGL) cells in response to OS inductors (glucose or peroxynitrite) and/or antioxidants. Our results show that celastrol and melatonin improve cell survival in the presence and absence of OS inductors. In addition, melatonin induced SIRT1, SIRT6 and SIRT7 gene expression while celastrol only induced SIRT7 gene expression. This response was not altered by the addition of OS inductors. Our previous data for cultured hGL cells showed a dual role of celastrol as a free radical scavenger and as a protective agent by regulating gene expression. This study shows a direct effect of celastrol on SIRT7 gene expression. Melatonin may protect from OS in a receptor-mediated manner rather than as a scavenger. In conclusion, our results show increased hGL cells survival with melatonin or celastrol treatment under OS conditions, probably through the regulation of nuclear sirtuins’ gene expression.

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In Vivo Induction of Glial Cell Proliferation and Axonal Outgrowth and Myelination by Brain-Derived Neurotrophic Factor

Molecular Endocrinology ◽

10.1210/me.2006-0168 ◽

2006 ◽

Vol 20 (11) ◽

pp. 2987-2998 ◽

Cited By ~ 19

Author(s):

Dorien M. de Groot ◽

Anton J. M. Coenen ◽

Albert Verhofstad ◽

François van Herp ◽

Gerard J. M. Martens

Keyword(s):

Cell Proliferation ◽

Cell Survival ◽

Glial Cell ◽

Glial Cells ◽

Neurotrophic Factor ◽

Transgene Expression ◽

Neuronal Cell ◽

Axonal Outgrowth ◽

Glial Cell Proliferation

Abstract Brain-derived neurotrophic factor (BDNF) belongs to the neurotrophin family of neuronal cell survival and differentiation factors but is thought to be involved in neuronal cell proliferation and myelination as well. To explore the role of BDNF in vivo, we employed the intermediate pituitary melanotrope cells of the amphibian Xenopus laevis as a model system. These cells mediate background adaptation of the animal by producing high levels of the prohormone proopiomelanocortin (POMC) when the animal is black adapted. We used stable X. transgenesis in combination with the POMC gene promoter to generate transgenic frogs overexpressing BDNF specifically and physiologically inducible in the melanotrope cells. Intriguingly, an approximately 25-fold overexpression of BDNF resulted in hyperplastic glial cells and myelinated axons infiltrating the pituitary, whereby the transgenic melanotrope cells became located dispersed among the induced tissue. The infiltrating glial cells and axons originated from both peripheral and central nervous system sources. The formation of the phenotype started around tadpole stage 50 and was induced by placing white-adapted transgenics on a black background, i.e. after activation of transgene expression. The severity of the phenotype depended on the level of transgene expression, because the intermediate pituitaries from transgenic animals raised on a white background or from transgenics with only an approximately 5-fold BDNF overexpression were essentially not affected. In conclusion, we show in a physiological context that, besides its classical role as neuronal cell survival and differentiation factor, in vivo BDNF can also induce glial cell proliferation as well as axonal outgrowth and myelination.

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Heme Oxygenase-1 at the Nexus of Endothelial Cell Fate Decision Under Oxidative Stress

Frontiers in Cell and Developmental Biology ◽

10.3389/fcell.2021.702974 ◽

2021 ◽

Vol 9 ◽

Author(s):

Sindhushree Raghunandan ◽

Srinivasan Ramachandran ◽

Eugene Ke ◽

Yifei Miao ◽

Ratnesh Lal ◽

...

Keyword(s):

Oxidative Stress ◽

Gene Expression ◽

Stress Response ◽

Cell Surface ◽

Cell Survival ◽

Cell Fate ◽

Heme Oxygenase ◽

Molecular Mechanisms ◽

Heme Oxygenase 1 ◽

Cell Fate Decisions

Endothelial cells (ECs) form the inner lining of blood vessels and are central to sensing chemical perturbations that can lead to oxidative stress. The degree of stress is correlated with divergent phenotypes such as quiescence, cell death, or senescence. Each possible cell fate is relevant for a different aspect of endothelial function, and hence, the regulation of cell fate decisions is critically important in maintaining vascular health. This study examined the oxidative stress response (OSR) in human ECs at the boundary of cell survival and death through longitudinal measurements, including cellular, gene expression, and perturbation measurements. 0.5 mM hydrogen peroxide (HP) produced significant oxidative stress, placed the cell at this junction, and provided a model to study the effectors of cell fate. The use of systematic perturbations and high-throughput measurements provide insights into multiple regimes of the stress response. Using a systems approach, we decipher molecular mechanisms across these regimes. Significantly, our study shows that heme oxygenase-1 (HMOX1) acts as a gatekeeper of cell fate decisions. Specifically, HP treatment of HMOX1 knockdown cells reversed the gene expression of about 51% of 2,892 differentially expressed genes when treated with HP alone, affecting a variety of cellular processes, including anti-oxidant response, inflammation, DNA injury and repair, cell cycle and growth, mitochondrial stress, metabolic stress, and autophagy. Further analysis revealed that these switched genes were highly enriched in three spatial locations viz., cell surface, mitochondria, and nucleus. In particular, it revealed the novel roles of HMOX1 on cell surface receptors EGFR and IGFR, mitochondrial ETCs (MTND3, MTATP6), and epigenetic regulation through chromatin modifiers (KDM6A, RBBP5, and PPM1D) and long non-coding RNA (lncRNAs) in orchestrating the cell fate at the boundary of cell survival and death. These novel aspects suggest that HMOX1 can influence transcriptional and epigenetic modulations to orchestrate OSR affecting cell fate decisions.

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Antioxidative Capacity of Liver- and Adipose-Derived Mesenchymal Stem Cell-Conditioned Media and Their Applicability in Treatment of Type 2 Diabetic Rats

Oxidative Medicine and Cellular Longevity ◽

10.1155/2021/8833467 ◽

2021 ◽

Vol 2021 ◽

pp. 1-11

Author(s):

Mohamed M. Elshemy ◽

Medhat Asem ◽

Khaled S. Allemailem ◽

Koichiro Uto ◽

Mitsuhiro Ebara ◽

...

Keyword(s):

Oxidative Stress ◽

Insulin Resistance ◽

Stem Cell ◽

Growth Factors ◽

Mesenchymal Stem Cell ◽

Angiogenic Factors ◽

Conditioned Media ◽

Therapeutic Effects ◽

Differentiation Potential

Type 2 diabetes mellitus (T2DM) is mainly characterized by insulin resistance and impaired insulin secretion, which cannot be reversed with existing therapeutic strategies. Using mesenchymal stem cells (MSCs), cell-based therapy has been demonstrated in displaying therapeutic effects in T2DM for their self-renewable, differentiation potential, and immunosuppressive properties and higher levels of angiogenic factors. Stem cell therapies are complicated and have a serious adverse effect including tumor formation and immunogenicity, while using mesenchymal stem cell-conditioned media (MSC-CM) significantly reduces stem cell risk, maintaining efficacy and showing significantly higher levels of growth factors, cytokines, and angiogenic factors that stimulate angiogenesis and promote fracture healing in diabetes. In the present study, we investigated the therapeutic potential of the liver and adipose MSC-CM in diabetic endothelial dysfunction compared with standard insulin therapy. Fifty adult male Sprague Dawley rats were divided equally into 5 groups as follows: control, diabetic, diabetic+insulin, diabetic+liver MSC-CM, and diabetic+adipose MSC-CM; all treatments continued for 4 weeks. Finally, we observed that liver MSC-CM therapy had the most apparent improvement in levels of blood glucose; HbA1c; AGEs; lipid panel (cholesterol, TG, LDL, HDL, and total lipids); renal function (urea, uric acid, creatinine, and total protein); liver function (AST, ALT, ALP, bilirubin, and albumin); CPK; C-peptide; HO-1; inflammatory markers including IL-6, TNF-α, and CRP; growth factors (liver and serum IGF-1); amylase; histopathological changes; pancreatic cell oxidative stress; and antioxidant markers (MDA, GSH, ROS, CAT, SOD, HO-1, and XO) toward the normal levels compared with insulin and adipose MSCs-CM. Moreover, both the liver and adipose MSC-CM relieved the hyperglycemic status by improving pancreatic islet β cell regeneration, promoting the conversion of alpha cells to beta cells, reducing insulin resistance, and protecting pancreatic tissues against oxidative stress-induced injury as well as possessing the ability to modulate immunity and angiogenesis. These results indicated that MSC-CM infusion has therapeutic effects in T2DM rats and may be a promising novel therapeutic target.

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Gab1 Is an Integrator of Cell Death versus Cell Survival Signals in Oxidative Stress

Molecular and Cellular Biology ◽

10.1128/mcb.23.13.4471-4484.2003 ◽

2003 ◽

Vol 23 (13) ◽

pp. 4471-4484 ◽

Cited By ~ 39

Author(s):

Marina Holgado-Madruga ◽

Albert J. Wong

Keyword(s):

Oxidative Stress ◽

Growth Factors ◽

Cell Survival ◽

Signaling Pathways ◽

Kinase Inhibitor ◽

Large Body ◽

Wild Type Mouse ◽

Homozygous Deletion ◽

Dependent Manner ◽

Jnk Activation

ABSTRACT Upon the addition of different growth factors and cytokines, the Gab1 docking protein is tyrosine phosphorylated and in turn activates different signaling pathways. On the basis of the large body of evidence concerning cross talk between the signaling pathways activated by growth factors and oxidative stress, we decided to investigate the role of Gab1 in oxidative injury. We stimulated wild-type mouse embryo fibroblasts (MEF) or MEF with a homozygous deletion of the Gab1 gene (−/− MEF) with H2O2. Our results show that Gab1 is phosphorylated in a dose- and time-dependent manner after H2O2 triggering. Gab1 then recruits molecules such as SHP2, phosphatidylinositol 3-kinase (PI3K), and Shc. Gab1 phosphorylation is sensitive to the Src family kinase inhibitor PP2. Furthermore, we demonstrate that Gab1 is required for H2O2-induced c-Jun N-terminal kinase (JNK) activation but not for ERK2 or p38 activation. Reconstitution of Gab1 in −/− MEF rescues JNK activation, and we find that this is dependent on the SHP2 binding site in Gab1. Cell viability assays reveal that Gab1 has a dual role in cell survival: a positive one through its interaction with PI3K and a negative one through its interaction with SHP2. This is the first report identifying Gab1 as a component in oxidative stress signaling and one that is required for JNK activation.

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Gliogenesis inDrosophila: genome-wide analysis of downstream genes ofglial cells missingin the embryonic nervous system

Development ◽

10.1242/dev.129.14.3295 ◽

2002 ◽

Vol 129 (14) ◽

pp. 3295-3309 ◽

Cited By ~ 4

Author(s):

Boris Egger ◽

Ronny Leemans ◽

Thomas Loop ◽

Lars Kammermeier ◽

Yun Fan ◽

...

Keyword(s):

Gene Expression ◽

Transcription Factor ◽

Glial Cell ◽

Cell Fate ◽

Glial Cells ◽

Early Stage ◽

Genome Wide Analysis ◽

Glial Development ◽

Genome Wide

In Drosophila, the glial cells missing (gcm) gene encodes a transcription factor that controls the determination of glial versus neuronal fate. In gcm mutants, presumptive glial cells are transformed into neurons and, conversely, when gcm is ectopically misexpressed, presumptive neurons become glia. Although gcm is thought to initiate glial cell development through its action on downstream genes that execute the glial differentiation program, little is known about the identity of these genes. To identify gcm downstream genes in a comprehensive manner, we used genome-wide oligonucleotide arrays to analyze differential gene expression in wild-type embryos versus embryos in which gcm is misexpressed throughout the neuroectoderm. Transcripts were analyzed at two defined temporal windows during embryogenesis. During the first period of initial gcm action on determination of glial cell precursors, over 400 genes were differentially regulated. Among these are numerous genes that encode other transcription factors, which underscores the master regulatory role of gcm in gliogenesis. During a second later period, when glial cells had already differentiated, over 1200 genes were differentially regulated. Most of these genes, including many genes for chromatin remodeling factors and cell cycle regulators, were not differentially expressed at the early stage, indicating that the genetic control of glial fate determination is largely different from that involved in maintenance of differentiated cells. At both stages, glial-specific genes were upregulated and neuron-specific genes were downregulated, supporting a model whereby gcm promotes glial development by activating glial genes, while simultaneously repressing neuronal genes. In addition, at both stages, numerous genes that were not previously known to be involved in glial development were differentially regulated and, thus, identified as potential new downstream targets of gcm. For a subset of the differentially regulated genes, tissue-specific in vivo expression data were obtained that confirmed the transcript profiling results. This first genome-wide analysis of gene expression events downstream of a key developmental transcription factor presents a novel level of insight into the repertoire of genes that initiate and maintain cell fate choices in CNS development.

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