Age-Related Injury Responses of Human Oligodendrocytes to Metabolic Insults: Link to BCL-2 and Autophagy Pathways [Microarray]
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE160811 | GEO | 2020/12/31
REPOSITORIES: GEO
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Project description:Myelin destruction and oligodendrocyte (OL) death consequent to metabolic stress is a feature of CNS disorders across the age spectrum. Using cells derived from surgically resected tissue, we demonstrate that young (<age 5) pediatric-aged sample OLs are more resistant to in-vitro metabolic injury than fetal O4+ progenitor cells, but more susceptible to cell death and apoptosis than adult-derived OLs. Pediatric but not adult OLs show measurable levels of TUNEL+ cells, a feature of the fetal cell response. The ratio of anti- versus pro-apoptotic BCL-2 family genes are increased in adult versus pediatric (<age 5) mature OLs and in more mature OL lineage cells. Lysosomal gene expression was increased in adult and pediatric compared to fetal OL lineage cells. Cell death of OLs was increased by inhibiting pro-apoptotic BCL-2 gene and autophagy activity. These distinct age-related injury responses should be considered in designing therapies aimed at reducing myelin injury.
2020-12-31 | GSE160810 | GEO
Project description:Metformin restores myelination potential of aged rat A2B5+ oligodendroglia (OL) progenitor cells and may enhance recovery in children with post-radiation brain injury. Human late progenitor cells (O4+A2B5+) have superior capacity to ensheath nanofibers compared to mature OLs, with cells from pediatric sources exceeding adults. In this study we assessed effects of metformin on ensheathment capacity of human adult and pediatric progenitors and mature OLs and relate differences to transcriptional changes. A2B5+ progenitors and mature OLs, derived from surgical tissues by immune-magnetic separation, were assessed for ensheathment capacity in nanofiber plates over 2 weeks. Metformin (10µM every other day) was added to selected cultures. RNA was extracted from treated and control cultures after 2 days. For all ages, ensheathment by progenitors exceeded mature OLs. Metformin enhanced ensheathment by adult donor cells but reduced ensheathment by pediatric cells. Metformin marginally increased cell death in pediatric progenitors. Metformin induced changes in gene expression distinct for each cell type. Adult progenitors showed up-regulation of pathways involved in process outgrowth and promoting lipid biosynthesis. Pediatric progenitors showed a relatively greater proportion of down- versus up-regulated pathways, these involved cell morphology, development, and synaptic transmission. Metformin induced AMPK activation in all cell types; AMPK inhibitor BML-275 reduced functional metformin effects only with adult cells. Our results indicate age and differentiation stage related differences of human OL lineage cells in response to metformin. Clinical trials for demyelinating conditions will indicate how these differences translate in vivo.
2023-11-11 | GSE247159 | GEO
Project description:Arrest of oligodendrocyte (OL) differentiation and remyelination following myelin damage in Multiple Sclerosis (MS) are associated with disease progression but the underlying mechanism are elusive. We show that Glutathione S-transferase 4α (Gsta4) is highly expressed during adult OL differentiation and that its loss prevents differentiation into myelinating OLs. Also, Gsta4 appeared to be a novel target for Clemastine, in clinical trial for MS. Over-expression of Gsta4 reduced the expression of Fas and activity along the mitochondria-associated Casp8/Bid-axis in adult pre-OLs from the corpus callosum, together promoting enhanced pre-OL survival during differentiation. The Gsta4-mediated input on apoptosis during adult OL differentiation was further verified in the LPC and EAE model, where Casp8 were reduced in pre-OLs with high Gsta4 expression in an immune response-independent fashion. Our results place Gsta4 as a key regulator of intrinsic mechanisms beneficial for OL differentiation and remyelination, and as a possible target for future MS therapies.
2020-07-23 | GSE154922 | GEO
Project description:Multiple sclerosis (MS) is characterized by the loss of myelin and of myelin-producing oligodendrocytes (OLs) in the central nervous system (CNS). Pro-inflammatory CD4+ Th17 cells are considered pathogenic in MS and are harmful to OLs. We investigated the mechanisms driving human CD4+ T cell-mediated OL cell death. Using single cell RNA sequencing, we assessed the transcriptomic profile of primary human OLs and Th17 cells in direct contact or separated by an insert. We showed that upon close interaction, OLs upregulate the expression of mRNA coding for chemokines and antioxidant/anti-apoptotic molecules, while Th17 cells upregulate the expression of mRNA coding for chemokines and pro-inflammatory cytokines such as IL-17A, IFN-γ and granzyme B. We found that secretion of CCL3, CXCL10, IFN-γ, TNFα and granzyme B is induced upon direct contact in co-cultures of human Th17 cells with human OLs. In addition, we validated by flow cytometry and immunofluorescence that granzyme B levels are upregulated in Th17 compared to Th2 cells, and are even higher in Th17 cells upon direct contact with OLs or MO3.13 cells compared to Th17 cells separated from OLs by an insert.
2022-02-28 | GSE196953 | GEO
Project description:Oligodendrocytes (OLs) and myelin are critical for normal brain function and they have been implicated in neurodegeneration. Human neuroimaging studies have demonstrated that alterations in axons and myelin occur early in Alzheimer’s Disease (AD) course. However, the molecular mechanism underlying the role of OLs in AD remains largely unknown. In this study, we systematically interrogated OL-enriched gene networks constructed from large-scale genomic, transcriptomic, and proteomic data in human AD postmortem brain samples. These robust OL networks were highly enriched for genes associated with AD risk variants, including BIN1. We corroborated the structure of the AD OL coexpression and gene-gene interaction networks through ablation of genes identified as key drivers of the networks, including UGT8, CNP, MYRF, PLP1, NPC1, and NDGR1. Perturbations of these key drivers not only caused dysregulation in their associated network neighborhoods, but also mimicked pathways of gene expression dysregulation seen in human AD postmortem brain samples. In particular, the OL subnetwork controlled by the AD risk gene PSEN1 was strongly dysregulated in AD, suggesting a potential role of PSEN1 in disrupting the myelination pathway towards the onset of AD. In summary, this study built and systematically validated the first comprehensive molecular blueprint of OL dysregulation in AD, and identified key OL- and myelination-related genes and networks as potential candidate targets for the future development of AD therapies.
2018-02-23 | GSE80437 | GEO
Project description:Characterizing the developmental trajectory of oligodendrocyte progenitor cells (OPC) is of great interest given the importance of these cells in the remyelination process. However, studiescof human OPC development remain limited by the availability of whole cell samples and material that encompasses a wide age range, including time of peak myelination. In this study, we apply single cell RNA sequencing to viable whole cells across the age span and link transcriptomic signatures of oligodendrocyte-lineage cells with stage-specific functional properties. Cells were isolated from surgical tissue samples of second-trimester fetal, 2 year old pediatric, 13 year old adolescent, and adult donors by mechanical and enzymatic digestion, followed by percoll gradient centrifugation. Gene expression was analyzed using droplet-based RNA sequencing (10X Chromium). Louvain clustering analysis identified 3 distinct cellular subpopulations based on 5613 genes, comprised of an early OL precursor cell (e-OPC) group, a late OPC group (l-OPC), and a mature OL (MOL) group. Gene ontology terms enriched for e-OPCs were cell cycle and development, for l-OPCs were extracellular matrix and cell adhesion, and for MOLs were myelination and cytoskeleton. The e-OPCs were mostly confined to the premyelinating fetal group, and the l-OPCs were most highly represented in the pediatric age group, corresponding to the peak age of myelination. Cells expressing a signature characteristic of l-OPCs were identified in the adult brain in situ using RNAScope. These findings highlight the transcriptomic variability in OL-lineage cells before, during, and after peak myelination and contribute to identifying novel pathways required to achieve remyelination.
2021-01-12 | GSE155488 | GEO
Project description:Single-cell RNA-seq of a mouse model of MS uncovers new oligodendrocyte populations, putative disease markers and suggests new mechanisms underlying the pathogenesis of disease. In Multiple Sclerosis (MS), oligodendrocytes (OLs) are damaged during an immune system attack targeting myelin. It remains unclear how different OL lineage cells respond to inflammatory autoimmune demyelination in MS. We performed single-cell transcriptomics analysis of OL lineage cells from the spinal cord of mice induced with experimental autoimmune encephalomyelitis (EAE), which mimics certain aspects of MS. We found unique OLs and OL precursor cells (OPCs) in EAE, including populations expressing genes involved in antigen processing and presentation via major histocompatibility complex (MHC) Class I and II, but also in immunoprotection. We further uncovered several genes specifically alternatively spliced in OL lineage cells in EAE, including Mbp, Mobp and Pdgfa. Strikingly, we identified a substantial number of genes known to be susceptibility genes for MS, so far mainly associated with immune cells in the context of this disease, to be expressed in the OL lineage cells. Finally, we found that disease-specific oligodendroglia are present in human MS brains. Our results suggest that OL and OPCs are not passive targets but instead active immunomodulators in MS. The disease-specific OL lineage cells, for which we identify several biomarkers, may represent novel direct targets for immunomodulatory therapeutic approaches in MS.
2018-08-25 | GSE113973 | GEO
Project description:The differentiation of oligodendroglia from oligodendrocyte precursor cells (OPCs) to complex and extensive myelinating oligodendrocytes (OLs) is a multistep process that involves largescale morphological changes with significant strain on the cytoskeleton. While key chromatin and transcriptional regulators of differentiation have been identified, their target genes responsible for the morphological changes occurring during OL myelination are still largely unknown. Here, we show that the regulator of focal adhesion, Tensin3 (Tns3), is a direct target gene of Olig2, Chd7, and Chd8, transcriptional regulators of OL differentiation. Tns3 is transiently upregulated and localized to cell processes of immature OLs, together with integrin-b1, a key mediator of survival at this transient stage. Constitutive Tns3 loss-of-function leads to reduced viability in mouse and humans, with surviving knockout mice still expressing Tns3 in oligodendroglia. Acute deletion of Tns3 in vivo, either in postnatal neural stem cells (NSCs) or in OPCs, leads to a two-fold reduction in OL numbers. We find that the transient upregulation of Tns3 is required to protect differentiating OPCs and immature OLs from cell death by preventing the upregulation of p53, a key regulator of apoptosis. Altogether, our findings reveal a specific time window during which transcriptional upregulation of Tns3 in immature OLs is required for OL differentiation likely by mediating integrin-b1 survival signaling to the actin cytoskeleton as OL undergo the large morphological changes required for their terminal differentiation.
2022-09-01 | GSE203294 | GEO
Project description:The differentiation of oligodendroglia from oligodendrocyte precursor cells (OPCs) to complex and extensive myelinating oligodendrocytes (OLs) is a multistep process that involves largescale morphological changes with significant strain on the cytoskeleton. While key chromatin and transcriptional regulators of differentiation have been identified, their target genes responsible for the morphological changes occurring during OL myelination are still largely unknown. Here, we show that the regulator of focal adhesion, Tensin3 (Tns3), is a direct target gene of Olig2, Chd7, and Chd8, transcriptional regulators of OL differentiation. Tns3 is transiently upregulated and localized to cell processes of immature OLs, together with integrin-b1, a key mediator of survival at this transient stage. Constitutive Tns3 loss-of-function leads to reduced viability in mouse and humans, with surviving knockout mice still expressing Tns3 in oligodendroglia. Acute deletion of Tns3 in vivo, either in postnatal neural stem cells (NSCs) or in OPCs, leads to a two-fold reduction in OL numbers. We find that the transient upregulation of Tns3 is required to protect differentiating OPCs and immature OLs from cell death by preventing the upregulation of p53, a key regulator of apoptosis. Altogether, our findings reveal a specific time window during which transcriptional upregulation of Tns3 in immature OLs is required for OL differentiation likely by mediating integrin-b1 survival signaling to the actin cytoskeleton as OL undergo the large morphological changes required for their terminal differentiation.
2022-09-01 | GSE203293 | GEO
Project description:Olig2 is a crucial factor in the specification and differentiation of oligodendrocyte precursor cells that give rise to mature, myelin-producing OLs in the developing and postnatal CNS; however, its role in adulthood is less well understood. To investigate the role Olig2 plays in regulating gene expression in the adult oligodendrocyte lineage in a physiologically-relevant context, we performed chromatin immunoprecipitation followed by next generation sequencing analysis using whole spinal cord tissue harvested from adult mice. We found that many of the Olig2-bound sites were associated with genes with biological processes corresponding to myelination and ensheathment, as well as cell cycle and cytoskeletal regulation, suggesting Olig2 continues to play a critical role in processes related to OL differentiation and myelination well into adulthood.
2017-10-20 | GSE103324 | GEO