Bulk RNA-seq of FACS sorted astrocytes upon microglial depletion
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE171321 | GEO | 2022/09/01
REPOSITORIES: GEO
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2018-06-07 | GSE107635 | GEO
Project description:Multiple Sclerosis (MS) is a leading cause of incurable progressive disability in young adults caused by inflammation in the central nervous system (CNS) that triggers demyelination, glial cell dysfunction and irreversible neuro-axonal damage1. While considerable progress has been made in treating early inflammatory relapsing-remitting MS, the mechanisms underpinning the progressive stage remain largely unknown. The capacity of microglia, the CNS-resident phagocytes, to clear tissue debris is essential for both maintaining and restoring CNS homeostasis2,3 and this capacity diminishes with age4-6. Age strongly associates with the risk of developing progressive MS7,8. Herein we demonstrate that the recovery from inflammation is dependent on the ability of microglia to clear tissue debris and that blocking this process leads to development of progressive disease in a murine model of MS. Microglia-specific deletion of the general autophagy regulator Atg7, but not the canonical macroautophagy protein Ulk1, led to increased intracellular accumulation of phagocytosed myelin. This further associated with the alteration of the microglial phenotype towards that previously described in other neurodegenerative diseases2,3,9. Moreover, Atg7 deficient microglia showed striking similarities with microglia from aged wild type mice, which also demonstrated accumulation of myelin debris and inability to recover from MS-like disease. In contrast, the induction of autophagy using the disaccharide Trehalose in aged mice led to functional myelin clearance and remission from MS-like disease. Our results demonstrate that a non-canonical form of autophagy in microglia is responsible for myelin clearance and that impairment of this pathway markedly changes microglial phenotype and prevents recovery from MS-like disease. Importantly, we show that using a disaccharide ubiquitously found in plant-derived foods to boost autophagy in cells in which this process is naturally diminished can be utilized for therapeutic purposes.Project was run on 4 lanes with a 10M sequencing depth
2020-10-15 | GSE154920 | GEO
Project description:Microglia are macrophages-like cells in the central nervous system (CNS) harboring important roles such as synaptic organization, phagocytosis of debris and apoptotic cells, and repairing damaged tissue. Microglial function is tightly controlled, but under certain pathological conditions, activated microglia can induce excess inflammation which injure live cells in the CNS. Therefore, suppression of microglia is a fundamental strategy to treat CNS disorders. We have previously shown that the antiepileptic drug levetiracetam (LEV) inhibits microglia activation, but mechanism remains unclear. The purpose of this study is to identify a target of LEV to suppress microglial activity.
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Project description:An animal’s ability to cope with or succumb to deleterious effects of chronic psychological stress may be rooted in the brain’s immune responses manifested in microglial activity. Mice subjected to chronic social defeat (CSD) were categorized as susceptible (CSD-S) or resilient (CSD-R) based on behavioral phenotyping, and their microglial RNAs were isolated and analyzed by global gene expression microarrays. Microglia transcriptome from CSD-S mice was enriched for pathways that describe phases of CNS healing to sterile injury including, inflammation, oxidative stress, debris clearance, and wound resolution. Histochemical experiments confirmed the array predictions: CSD-S microglia showed elevated phagocytosis and oxidative stress, and the brains of CSD-S but not CSD-R or HC mice showed vascular leakage of intravenously injected fluorescent tracers. The results suggest that the inflammatory profile of CSD-S microglia may be precipitated by leakage of blood-born substances into brain parenchyma. We hypothesize that these CNS-centric responses contribute to the stress-susceptible behavioral phenotype.
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Project description:Microglia are myeloid cells of the central nervous system (CNS) that participate both in normal CNS function and disease. We investigated the molecular signature of microglia and identified 239 genes and 8 microRNAs that were uniquely or highly expressed in microglia vs. myeloid and other immune cells. Out of 239 genes, 106 were enriched in microglia as compared to astrocytes, oligodendrocytes and neurons. This microglia signature was not observed in microglial lines or in monocytes recruited to the CNS and was also observed in human microglia. Based on this signature, we found a crucial role for TGF-β in microglial biology that included: 1) the requirement of TGF-β for the in vitro development of microglia that express the microglial molecular signature characteristic of adult microglia; and 2) the absence of microglia in CNS TGF-β1 deficient mice. Our results identify a unique microglial signature that is dependent on TGF-β signaling which provides insights into microglial biology and the possibility of targeting microglia for the treatment of CNS disease.
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Project description:While TGF-β signaling is essential for microglial function, the cellular source of TGF-β ligand and its spatial regulation remains unclear in adult CNS. Our data supports that microglia but not astrocytes or neurons are the primary producers of TGF-β1 ligands needed for microglial homeostasis. Microglia-Tgfb1 KO leads to activation of microglia featuring a dyshomeostatic transcriptomic profile that resembles disease-associated microglia (DAMs), injury-associated microglia, and aged microglia, suggesting that microglial self-produced TGF-β1 ligands are important in the adult CNS. Interestingly, astrocytes in the MG-tgfb1 iKO mice show a transcriptome profile that is closely aligned with A1-like astrocytes. Additionally, using sparse mosaic single cell microglia KO of TGF-β1 ligand we established an autocrine mechanism for TGF-β signaling. Importantly MG-Tgfb1 inducible KO mice show cognitive deficits, supporting that precise spatial regulation of TGF-β1 ligand derived from microglia is critical for the maintenance of brain homeostasis and normal cognitive function in the adult brain.
2023-08-08 | GSE236032 | GEO
Project description:Microglia are considered both pathogenic and protective during recovery from demyelination, but their precise role remains ill-defined. Here, using an inhibitor of colony stimulating factor 1 receptor (CSF1R), PLX5622, and mice infected with a neurotropic coronavirus (mouse hepatitis virus, strain JHMV), we show that depletion of microglia after clearance of virus infection resulted in impaired myelin repair and prolonged clinical disease. Microglia were required only during the early stages of remyelination. Notably, large deposits of extracellular vesiculated myelin and cellular debris were detected in the spinal cords of PLX5622-treated and not control mice, which correlated with decreased numbers of oligodendrocytes in demyelinating lesions in drug-treated mice. Further, gene expression analyses demonstrated differential expression of genes involved in myelin debris clearance, lipid and cholesterol recycling, and promotion of oligodendrocyte function. The results also demonstrate that microglial function could not be compensated by infiltrating macrophages. Together, these results demonstrate key roles for microglia in debris clearance and the initiation of remyelination following infection with a neurotropic coronavirus but are not necessary during later stages of remyelination.
2020-02-07 | GSE144911 | GEO
Project description:Traumatic brain injury (TBI) triggers neuroinflammatory cascades mediated by microglia, which promotes tissue repair in the short-term. These cascades may exacerbate TBI-induced tissue damage and symptoms in the months to years post-injury. However, the progression of the microglial function across time post-injury and whether this differs between biological sexes is not well understood. In this study, we examined the microglial proteome in the days (3- and 7-days) to 1 month (28 days) after a midline fluid percussion injury (mFPI) in male and female mice using label-free quantitative proteomics. We identified a reduction in microglial proteins involved with clearance of neuronal debris via phagocytosis at 3- and 7-days post-injury. At 28 days post-injury pro-inflammatory proteins were decreased and anti-inflammatory proteins were increased in microglia. These results indicate a reduction in microglial clearance of neuronal debris in the days post-injury with a shift to anti-inflammatory function by 1 month. The changes in the microglial proteome that occurred across time post-injury did not differ between biological sexes. However, we did identify an increase in microglial proteins related to pro-inflammation as well as insulin and estrogen signalling in males compared with female mice that occurred with or without a brain injury. Although microglial response was similar between males and females up to 1 month following TBI, biological sex differences in the basal microglial proteome has implications for the efficacy of treatment strategies targeting the microglial response post-injury.
2023-03-11 | PXD033628 | Pride
Project description:Microglia are resident CNS immune cells that are active sensors in healthy brain and versatile effectors under pathological conditions. Cerebral ischemia induces a robust neuroinflammatory response that includes marked changes in the gene expression and phenotypic profile of a variety of endogenous CNS cell types (astrocytes, neurons, microglia) as well as an influx of leukocytic cells (neutrophils, macrophages, T-cells) from the periphery. Many molecules and conditions can trigger a transformation of ârestingâ (or surveying) microglia to an âactivatedâ (alerted/reactive) state. Here we review recent developments in the literature that relate to microglial activation in the experimental setting of in vitro and in vivo ischemia. We also present new data from our own laboratory demonstrating the direct effects of in vitro ischemic conditions on the microglial phenotype and genomic profile. Emphasis is placed on the role of specific molecular signaling systems such as hypoxia inducible factor-1 (HIF-1) and toll-like receptor-4 (TLR4) in regulating the microglial response in this setting. We then review histological and recent novel radiological data that confirms a key role for microglial activation in the setting of ischemic stroke in humans. We discuss recent progress in the pharmacological and molecular targeting of microglia in acute ischemic stroke. Finally, we explore how recent studies on ischemic preconditioning have increased interest in preemptively targeting microglial activation in order to reduce stroke severity. 12 arrays, 4 experimental groups, 3 replicates in each group, CN is control normoxia, CH is control hypoxia, TN is TLR4 knockout normoxia, TH is TLR4 knockout hypoxia.
2010-10-05 | E-GEOD-18602 | biostudies-arrayexpress
Project description:GFAP and vimentin deficiency alters gene expression in astrocytes and microglia in wild-type mice and changes the transcriptional response of reactive glia in mouse model for Alzheimer's disease. Reactive astrocytes with an increased expression of intermediate filament (IF) proteins Glial Fibrillary Acidic Protein (GFAP) and Vimentin (VIM) surround amyloid plaques in Alzheimer's disease (AD). The functional consequences of this upregulation are unclear. To identify molecular pathways coupled to IF regulation in reactive astrocytes, and to study the interaction with microglia, we examined WT and APPswe/PS1dE9 (AD) mice lacking either GFAP, or both VIM and GFAP, and determined the transcriptome of cortical astrocytes and microglia from 15- to 18-month-old mice. Genes involved in lysosomal degradation (including several cathepsins) and in inflammatory response (including Cxcl5, Tlr6, Tnf, Il1b) exhibited a higher AD-induced increase when GFAP, or VIM and GFAP, were absent. The expression of Aqp4 and Gja1 displayed the same pattern. The downregulation of neuronal support genes in astrocytes from AD mice was absent in GFAP/VIM null mice. In contrast, the absence of IFs did not affect the transcriptional alterations induced by AD in microglia, nor was the cortical plaque load altered. Visualizing astrocyte morphology in GFAP-eGFP mice showed no clear structural differences in GFAP/VIM null mice, but did show diminished interaction of astrocyte processes with plaques. Microglial proliferation increased similarly in all AD groups. In conclusion, absence of GFAP, or both GFAP and VIM, alters AD-induced changes in gene expression profile of astrocytes, showing a compensation of the decrease of neuronal support genes and a trend for a slightly higher inflammatory expression profile. However, this has no consequences for the development of plaque load, microglial proliferation, or microglial activation. 2 cell types from 6 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-74614 | biostudies-arrayexpress