Transcriptomic analyses of astrocyte heterogeneity within white matter tracts
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE211515 | GEO | 2022/11/29
REPOSITORIES: GEO
Similar Datasets
Project description:The optic nerve is an important tissue in glaucoma and the unmyelinated nerve head region remains an important site of many early neurodegenerative changes. In humans and mice, astrocytes constitute the major glial cell type in the region, and in glaucoma they become reactive, influencing the optic nerve head (ONH) microenvironment and disease outcome. To determine the response of ONH astrocytes in glaucoma, we studied their transcriptional response to an elevation in intraocular pressure (IOP) induced by the microbead occlusion model. We also assessed the response of astrocytes in the more distal myelinated optic nerve proper (ONP). In this experimental model, astrocytes of the optic nerve exhibited a region-specific and temporally distinct response: ONH astrocytes showed very few early transcriptional changes and ONP astrocytes demonstrated substantially larger changes over the course of the experiment.
2023-10-01 | GSE237073 | GEO
Project description:A major risk factor for glaucomatous optic neuropathy is the level of intraocular pressure (IOP), which can lead to retinal ganglion cell axon injury and cell death. The optic nerve has a rostral unmyelinated portion at the optic nerve head followed by a caudal myelinated region. The unmyelinated region is differentially susceptible to IOP-induced damage in rodent models and in human glaucoma. While several studies have analyzed gene expression changes in the mouse optic nerve following optic nerve injury, few were designed to consider the regional gene expression differences that exist between these distinct areas. We performed bulk RNA-sequencing on the retina and on separately micro-dissected unmyelinated and myelinated optic nerve regions from naïve C57BL/6 mice, mice after optic nerve crush, and mice with microbead-induced experimental glaucoma (total = 36). Gene expression patterns in the naïve unmyelinated optic nerve showed significant enrichment of the Wnt, Hippo, PI3K-Akt, and transforming growth factor β pathways, as well as extracellular matrix–receptor and cell membrane signaling pathways, compared to the myelinated optic nerve and retina. Gene expression changes induced by both injuries were more extensive in the myelinated optic nerve than the unmyelinated region, and greater after nerve crush than glaucoma. Changes present three and fourteen days after injury largely subsided by six weeks. Gene markers of reactive astrocytes did not consistently differ between injury states. Overall, the transcriptomic phenotype of the mouse unmyelinated optic nerve was significantly different from immediately adjacent tissues, likely dominated by expression in astrocytes, whose junctional complexes are inherently important in responding to IOP elevation.
2023-09-06 | GSE241782 | GEO
Project description:Optic nerves are an accessible part of the CNS, providing a source of glia without the presence of neuronal cell bodies. Therefore, an analysis was carried out of gene expression in optic nerves at P4, before myelination begins and at P10, when myelination is very actively proceeding. The goal was to obtain a profile of the changing gene expression that accompanies this transition from unmyelinated CNS nerve to myelinated nerve.
2011-05-16 | GSE24513 | GEO
Project description:Optic nerves are an accessible part of the CNS, providing a source of glia without the presence of neuronal cell bodies. Therefore, an analysis was carried out of gene expression in optic nerves at P4, before myelination begins and at P10, when myelination is very actively proceeding. The goal was to obtain a profile of the changing gene expression that accompanies this transition from unmyelinated CNS nerve to myelinated nerve. Two microarray experiments were combined here. In the first, RNA was prepared from the optic nerves of 75 P4 C57BL/6J mice and 70 P10 C57BL/6J mice. In the second experiment, RNA was prepared from the optic nerves of 55 P4 C57BL/6J mice and two groups of 50 P10 C57Bl/6J mice. In total, there are 2 P4 RNA samples and 3 P10 RNA samples being hybridized to Affymetrix GeneChip 430A for Mouse Expression.
2011-05-16 | E-GEOD-24513 | biostudies-arrayexpress
Project description:Gene expression in human optic nerve head (ONH) astrocytes
| PRJNA87709 | ENA
Project description:This SuperSeries is composed of the following subset Series:; GSE9939: Gene expression data on human optic nerve head astrocytes in normal Caucasian and African americans; GSE9944: Gene expression data on human optic nerve head astrocytes in Caucasian and African americans with or without glaucoma Experiment Overall Design: Refer to individual Series
2008-04-07 | E-GEOD-9963 | biostudies-arrayexpress
Project description:Glaucoma, a multifactorial neurodegenerative disease characterized by progressive loss of retinal ganglion cells and their axons in the optic nerve, is a leading cause of irreversible vision loss. Intraocular pressure (IOP) is a risk factor for axonal damage, which initially occurs at the optic nerve head (ONH). Complex cellular and molecular mechanisms involved in the pathogenesis of glaucomatous optic neuropathy remain unclear. Here we define early molecular events in the ONH in an inherited large animal glaucoma model in which ONH structure resembles that of humans. Gene expression profiling of ONH tissues from rigorously phenotyped feline subjects with early-stage glaucoma and precisely age-matched controls was performed by RNA-sequencing (RNA-seq) analysis and complementary bioinformatic approaches applied to identify molecular processes and pathways of interest. Immunolabeling supported RNA-seq findings while providing cell-, region-, and disease stage–specific context in the ONH in situ. Transcriptomic evidence for cell proliferation and immune/inflammatory responses is identifiable in early glaucoma, soon after IOP elevation and prior to morphologically detectable axon loss, in this large animal model. In particular, proliferation of microglia and oligodendrocyte precursor cells is a prominent feature of early-stage, but not chronic, glaucoma. ONH microgliosis is a consistent hallmark in both early and chronic stages of glaucoma. Molecular pathways and cell type–specific responses strongly implicate toll-like receptor and NF-κB signaling in early glaucoma pathophysiology. The current study provides critical insights into molecular pathways, highly dependent on cell type and sub-region in the ONH even prior to irreversible axon degeneration in glaucoma.
2020-04-07 | GSE110019 | GEO
Project description:The normal gene expression profiles of the tissues in the eye are a valuable resource for considering genes likely to be involved with disease processes. This is based on the assumption that transcript abundances in healthy tissue are correlated to the continued health of that tissue. Expression values were compared with publically available EST and RNA-sequencing resources. The estimated gene and exon level abundances are available online on the Ocular Tissue Database. Ten different tissues were obtained from 6 different individuals and RNA was pooled. The tissues included: retina, optic nerve head (ONH), optic nerve (ON), ciliary body (CB), trabecular meshwork (TM), sclera, lens, cornea, choroid/RPE and iris.
2013-04-17 | E-GEOD-41102 | biostudies-arrayexpress
Project description:Astrocytes from optic nerve head from donors with and without glaucoma
2007-08-21 | E-GEOD-2378 | biostudies-arrayexpress
Project description:The resident astrocytes-retinal ganglion cell lipoxin circuit is impaired during retinal stress that include exocytotoxic- and ocular hypertension-induced neuropathy. Two endogenous lipoxins (Lipoxin A4 and Lipoxin B4) produced by homeostatic astrocytes directly act on RGCs. LXB4 is the most potent lipoxin in the retina and directly increases RGC survival and function in ocular hypertension-induced neuropathy. Homeostatic roles and cellular targets of LXB4 in the retina and optic nerve are a critical gap in knowledge. Single-cell RNA sequencing was used to define cellular targets and signaling of LXB4 in the retina. For modeling neurodegeneration, sustained ocular hypertension was induced by silicone-oil injection in the anterior chamber of mouse eyes. For morphological characterization of microglia populations in the retina and optic nerve, we used MorphOMICs and pseudotime trajectory analysis. Bulk RNA sequencing of optic nerves was performed to characterize pathways and mechanism of action for LXB4. qPCR and immunohistochemistry were used for validation of transcriptomics data. Student’s t-test and one-way ANOVA were used to determine differences between experimental groups. Single Cell transcriptomic identified microglia as a primary target for LXB4 in the healthy retina. LXB4 downregulated genes that drive microglia environmental sensing and reactivity responses. Analysis of microglia function uncovered that ocular hypertension induces distinct, temporally defined and dynamic phenotypes in the retina and, unexpectedly, in the distal myelinated optic nerve. Microglial expression of CD74, a marker of disease-associated microglia (DAM) in the brain, was only induced in a unique population of optic nerve microglia but not the retina. Genetic deletion of lipoxin formation correlated with presence of a CD74 optic nerve microglia population in normotensive eyes optic, while LXB4 treatment during ocular hypertension shifted optic nerve microglia toward a homeostatic morphology and non-reactive state and downregulated expression of CD74. Furthermore, we identified a correlation between CD74 and phospho-PI3K (p-PI3K) expression levels in the optic nerve, that was reduced by LXB4 treatment. Results identify distal optic nerve microglial dynamic and reactive responses as a key feature of ocular hypertension induce neurodegeneration. Our findings establish microglia regulation as a new LXB4 cell target in the retina and optic nerve. LXB4 maintenance of optic nerve microglia homeostatic phenotype and inhibition of a disease-associated phenotype are potential mechanisms for LXB4 neuroprotection.
2024-04-10 | GSE251716 | GEO