Expression data from reactive astrocytes acutely purified from young adult mouse brains
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE35338 | GEO | 2012/05/02
SECONDARY ACCESSION(S): PRJNA152707
REPOSITORIES: GEO
Similar Datasets
Project description:Reactive astrogliosis is characterized by a profound change in astrocyte phenotype in response to all CNS injuries and diseases. To better understand the reactive astrocyte state, we used Affymetrix GeneChip arrays to profile gene expression in populations of reactive astrocytes isolated at various time points after induction using two different mouse injury models, ischemic stroke and neuroinflammation. Young adult male mice underwent middle cerebral artery occlusion (MCAO) to produce ischemic stroke or control sham surgery. Young adult mice were injected intraperitoneally with 5 mg/kg lipopolysaccharide (LPS) to produce neuroinflammation or saline for control. Astrocytes were acutely purified from control and injured brains at 1 day after injury for LPS/saline injection and 1, 3 days and 7 days after MCAO/sham surgeries.
2012-05-01 | E-GEOD-35338 | biostudies-arrayexpress
Project description:Astrogliosis is a hallmark of the response to brain ischemia, comprised of changes in gene expression and morphology. Hsp72 protects from cerebral ischemia, and although several mechanisms of protection have been investigated, effects on astrocyte activation are unknown. To identify potential mechanisms of protection, gene expression was assessed in mice subjected to middle cerebral artery (MCAO) or sham surgery, of either wildtype (WT) or Hsp72-overexpressing (Hsp72Tg) mice. After stroke, both genotypes exhibited genes related to cell death, stress response, and immune response. Furthermore, genes indicative of astrocyte activation, including cytoskeletal proteins and cytokines, were upregulated. To measure astrocyte activation after stroke, detailed histological and morphological analyses were performed in the cortical penumbra after stroke using unbiased stereology. Consistent with other reports, we observed a marked and persistent increase in glial fibrillary acidic protein (GFAP ) as soon as 3 hours after MCAO. In contrast, vimentin immunoreactivity appeared 12-24 hours after stroke, peaked at 72 hours, and returned to baseline after 30 days. Surprisingly, no change in overall astrocyte number was observed based on glutamine synthetase (GS) immunoreactivity. To determine if Hsp72Tg mice exhibited altered astrocyte activation compared to WT controls, morphological evaluation by fractal analysis was used. Overexpression of Hsp72 reduced astrocyte cell area, arbor area, and to a lesser extent fractal dimension, 72 hours following stroke. In conclusion, in vivo overexpression of Hsp72 alters gene expression following stroke, including genes involved in astrocyte activation, and decreases astrocyte activation acutely following MCAO. Thus, modulation of astrogliosis may be a neuroprotective mechanism exerted by Hsp72 after ischemia. A total of 10 samples were analyzed, with 5 of each genotype, wildtype (WT) and Hsp72-overexpressing (Hsp72Tg) mice. Of the 5 in each group, 3 received middle cerebral artery occlusion (MCAO) and 2 received a sham surgery. The sham samples serve as the controls for the MCAO samples in each genotype. All samples were taken from the ischemic or control hemisphere 24 hours after surgery.
2013-01-11 | E-GEOD-28731 | biostudies-arrayexpress
Project description:Reactive astrogliosis is a well-known and recognised marker of Alzheimer's Disease (AD). The aim of this study is to functionally visualise reactive astrocyte-mediated neuronal hypometabolism in the brains that is associated with AD and neuroinflammation. To investigate alterations of acetate and glucose metabolism and the effect thereof in AD-like astrocytes, primary astrocyte cultures were treated with acetate in the presence or absence of amyloid beta (Aβ) oligomers. On comparison, we found that acetate treatment upregulated the expression of acetate transporter MCT1 (Slc16a1) as well as that of enzymes involved in the urea cycle and subsequent GABA synthesis. We could, therefore, conclude that MCT1-mediated uptake of acetate into astrocytes triggered GABA synthesis by upregulating enzymes involved in putrescine production and degradation.
2023-04-03 | GSE228468 | GEO
Project description:Astrogliosis is a hallmark of the response to brain ischemia, comprised of changes in gene expression and morphology. Hsp72 protects from cerebral ischemia, and although several mechanisms of protection have been investigated, effects on astrocyte activation are unknown. To identify potential mechanisms of protection, gene expression was assessed in mice subjected to middle cerebral artery (MCAO) or sham surgery, of either wildtype (WT) or Hsp72-overexpressing (Hsp72Tg) mice. After stroke, both genotypes exhibited genes related to cell death, stress response, and immune response. Furthermore, genes indicative of astrocyte activation, including cytoskeletal proteins and cytokines, were upregulated. To measure astrocyte activation after stroke, detailed histological and morphological analyses were performed in the cortical penumbra after stroke using unbiased stereology. Consistent with other reports, we observed a marked and persistent increase in glial fibrillary acidic protein (GFAP ) as soon as 3 hours after MCAO. In contrast, vimentin immunoreactivity appeared 12-24 hours after stroke, peaked at 72 hours, and returned to baseline after 30 days. Surprisingly, no change in overall astrocyte number was observed based on glutamine synthetase (GS) immunoreactivity. To determine if Hsp72Tg mice exhibited altered astrocyte activation compared to WT controls, morphological evaluation by fractal analysis was used. Overexpression of Hsp72 reduced astrocyte cell area, arbor area, and to a lesser extent fractal dimension, 72 hours following stroke. In conclusion, in vivo overexpression of Hsp72 alters gene expression following stroke, including genes involved in astrocyte activation, and decreases astrocyte activation acutely following MCAO. Thus, modulation of astrogliosis may be a neuroprotective mechanism exerted by Hsp72 after ischemia.
2013-01-11 | GSE28731 | GEO
Project description:Neuroinflammation is a hallmark of ischemic stroke, which is a leading cause of death and longterm disability. Understanding the exact cellular signaling pathways that initiate and propagate neuroinflammation after stroke will be critical for developing immunomodulatory stroke therapies. In particular, the precise mechanisms of inflammatory signaling in the clinically relevant hyperacute period, hours after stroke, have not been elucidated. We used the RiboTag technique to obtain Astrocyte IP and microglia-derived mRNA transcripts in a hyperacute (4 hours) and acute (3 days) period after stroke, as these two cell types are key modulators of acute neuroinflammation. Microglia initiated a rapid response to stroke at 4 hours by adopting an inflammatory profile associated with the recruitment of immune cells. The hyperacute Astrocyte IP profile was marked by stress response genes and transcription factors, such as Fos and Jun, involved in pro-inflammatory pathways such as TNF-α. By 3 days, microglia shift to a proliferative state and Astrocyte IPs strengthen their inflammatory response. The Astrocyte IP pro-inflammatory response at 3 days is partially driven by the upregulation of the transcription factors C/EBPβ, Spi1, and Rel, which comprise 25% of upregulated transcription factor-target interactions. Surprisingly, few sex differences across all groups were observed. Expression and log2 fold data for all sequenced genes are available on a user-friendly website for researchers to examine gene changes and generate hypotheses for stroke targets. Taken together our data comprehensively describe the Astrocyte IP and microglia-specific translatome response in the hyperacute and acute period after stroke and identify pathways critical for initiating neuroinflammation.
2023-02-14 | GSE225110 | GEO
Project description:Neuroinflammation is a common feature of neurodegenerative disorders such as Alzheimer's disease (AD). Neuroinflammation is induced by dysregulated glial activation, and astrocytes, the most abundant glial cells, become reactive upon neuroinflammatory cytokines released from microglia, and actively contribute to neuronal loss. Therefore, blocking reactive astrocyte functions is a viable strategy to manage neurodegenerative disorders. However, factors or therapeutics directly regulating astrocyte subtype remain unexplored. Here, we identified transcription factor NF-E2-related factor 2 (Nrf2) as a therapeutic target in neurotoxic reactive astrocytes upon neuroinflammation. We found that the absence of Nrf2 promoted the activation of reactive astrocytes in the brain tissue samples obtained from AD model 5xFAD mice, whereas enhanced Nrf2 expression blocked the induction of reactive astrocyte gene expression by counteracting NF-kB subunit p65 recruitment. Neuroinflammatory astrocytes robustly upregulated genes associated with type I interferon and the antigen-presenting pathway, which were suppressed by Nrf2 pathway activation. Moreover, impaired cognitive behaviors observed in AD mice were rescued upon ALGERNON2 treatment, which potentiated Nrf2 pathway and reduced the induction of neurotoxic reactive astrocytes. Thus, we highlight the potential of astrocyte-targeting therapy by promoting the Nrf2 pathway signaling for neuroinflammation-triggered neurodegeneration.
2023-08-07 | GSE237423 | GEO
Project description:Neuroinflammation is a common feature of neurodegenerative disorders such as Alzheimer's disease (AD). Neuroinflammation is induced by dysregulated glial activation, and astrocytes, the most abundant glial cells, become reactive upon neuroinflammatory cytokines released from microglia, and actively contribute to neuronal loss. Therefore, blocking reactive astrocyte functions is a viable strategy to manage neurodegenerative disorders. However, factors or therapeutics directly regulating astrocyte subtype remain unexplored. Here, we identified transcription factor NF-E2-related factor 2 (Nrf2) as a therapeutic target in neurotoxic reactive astrocytes upon neuroinflammation. We found that the absence of Nrf2 promoted the activation of reactive astrocytes in the brain tissue samples obtained from AD model 5xFAD mice, whereas enhanced Nrf2 expression blocked the induction of reactive astrocyte gene expression by counteracting NF-kB subunit p65 recruitment. Neuroinflammatory astrocytes robustly upregulated genes associated with type I interferon and the antigen-presenting pathway, which were suppressed by Nrf2 pathway activation. Moreover, impaired cognitive behaviors observed in AD mice were rescued upon ALGERNON2 treatment, which potentiated Nrf2 pathway and reduced the induction of neurotoxic reactive astrocytes. Thus, we highlight the potential of astrocyte-targeting therapy by promoting the Nrf2 pathway signaling for neuroinflammation-triggered neurodegeneration.
2023-08-07 | GSE237422 | GEO
Project description:Astroglia, the star-shaped cells found throughout the central nervous system are the most numerous cell type in the brain. The astroglial response to injury, generically termed reactive astrogliosis, is classically defined by cellular hypertrophy and process extension, increased glial filament production, and some degree of proliferation. Astrogliosis and its functional outcomes, glial scar formation and neuroinflammation, are often viewed as detrimental to recovery. However, increasing evidence points to neuroprotective roles of reactive astroglia in the setting of brain injury. Therapeutic modulation of this double-edged sword will require detailed knowledge of mechanisms by which specific signals induce detrimental and beneficial phenotypes. This proposal is is a logical extension of a published, peer reviewed study (Heffron DS and Mandell JW, Opposing roles of ERK and p38 MAP kinases in FGF2-induced astroglial process extension. Mol Cell Neurosci 2005, 28:779-90). The downstream gene expression changes underlying these pathway-specific responses are largely unknown. The data generated from the proposed project will delineate pathway-specific gene expression responses of astroglia to fibroblast growth factors. This information will allow a rational approach to pharmacological approaches to modulate reactive astrogliosis in brain and spinal cord injury. Determine the astroglial gene expression program elicited by fibroblast growth factor-2, and dissect specific contributions of the ERK and p38 MAP kinase pathways using highly specific pharmacological inhibitors. FGF2, acting via two distinct intracellular signaling pathways, ERK- and p38 MAPK, leads to pathway-specific gene expression changes in astrocytes which promote the morphological plasticity (ERK-dependent) and pro-inflammatory properties (p38-dependent) of reactive astroglia. Cell culture; Neonatal primary astrocyte cultures are prepared exactly as previously described (Heffron and Mandell, 2005), using slight modifications of established protocols (McCarthy and de Vellis, 1980). Astrocytes prepared with these methods comprised greater than 95% of cell cultures as determined by GFAP staining. Microglia are present as a contaminating cell type at a percentage of 3.6 ± 0.9% as determined by CD11B staining. For process induction experiments, cells are trypsinized and replated in DMEM with 1% fetal bovine serum. This low serum concentration is necessary for good adhesion of the cells. Pharmacological inhibitors are dissolved in DMSO and added 2 h later. P38 MAP kinase inhibitors SB202190 (Calbiochem) and the MEK inhibitor U0126 (Promega) are used at 20 µM. We previously determined that the inactive analog of SB 202190, SB202474 (Calbiochem) had no effects on pathway activation or astrocyte morphology. Therefore, the inactive drug analog will not be used in the array experiments. Final DMSO concentration in the drug treatments and vehicle controls is 0.2%. Human recombinant FGF2 (obtained from the National Cancer Institute Preclinical Repository) is used at 25 ng/ml, based on extensive dose/response analyses in our published work.
2008-06-15 | E-GEOD-6675 | biostudies-arrayexpress
Project description:Bulk RNA-sequencing of astrocytes in the APP NL-F and APP PS1 models of ß-amyloidopathy, in which aspects of AD-related pathology progress at different speed, shows age-dependent gene expression changes. However, bulk RNA-seq does not provide insight into the heterogeneity of expression within this cell type, particularly relevant for such models, where reactive astrogliosis is most prominent in the vicinity of plaques. To investigate astrocyte heterogeneity in ß-amyloidopathy models, we thus performed single cell RNA-sequencing on astrocytes separated by FACS.
2024-03-21 | E-MTAB-13937 | biostudies-arrayexpress
Project description:Isolation of glia from Alzheimer's mice reveals inflammation and dysfunction. Reactive astrocytes and microglia are associated with amyloid plaques in Alzheimer's disease (AD). Yet, not much is known about the molecular alterations underlying this reactive phenotype. To get an insight into the molecular changes underlying AD induced astrocyte and microglia reactivity, we performed a transcriptional analysis on acutely isolated astrocytes and microglia from the cortex of aged controls and APPswe/PS1dE9 AD mice. As expected, both cell types acquired a proinflammatory phenotype, which confirms the validity of our approach. Interestingly, we observed that the immune alteration in astrocytes was relatively more pronounced than in microglia. Concurrently, our data reveal that astrocytes display a reduced expression of neuronal support genes and genes involved in neuronal communication. The microglia showed a reduced expression of phagocytosis and/or endocytosis genes. Co-expression analysis of a human AD expression data set and the astrocyte and microglia data sets revealed that the inflammatory changes in astrocytes were remarkably comparable in mouse and human AD, whereas the microglia changes showed less similarity. Based on these findings we argue that chronically proinflammatory astrocyte and microglia phenotypes, showing a reduction of genes involved in neuronal support and neuronal signaling, are likely to contribute to the neuronal dysfunction and cognitive decline in AD. 2 cell types from 2 conditions: cortical microglia and cortical astrocytes from 15-18 month old APPswe/PS1dE9 mice compared to wildtype littermates. Biological replicates: microglia from APPswe/PS1dE9, N=7, microglia from WT, N=7, astrocytes from APPswe/PS1dE9, N=4, microglia from WT, N=4
2015-11-04 | E-GEOD-74615 | biostudies-arrayexpress