LPS-induced systemic inflammation mediates a protective effect against ischemic injury via microglia
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE244358 | GEO | 2023/12/19
REPOSITORIES: GEO
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Project description:Ischemic stroke is a common acute CNS disorder leading to nearly half a million deaths per year in Europe. The high mortality is primarily owed to the limited treatment options of restoring blood flow in a narrow time window of several hours. Furthermore, inflammatory processes in the days and weeks after ischemic stroke contribute to tissue loss and neurological deficits. The key cells that influence and control this inflammatory cascade are microglia, the innate immune cells of the CNS. Microglia can be influenced and activated by e.g. lipopolysaccharide (LPS),a bacterial cell membrane component. It has been previously shown, that repetitive LPS stimuli prior to infarction (termed immunological preconditioning) lead to reduced infarct volumina in mouse models of ischemic stroke. Furthermore, our laboratory has shown, that phosphoinositide-3 kinase gamma mediates microglial functions after LPS-preconditioning. Hence, the aim of this work was to characterize proteomic alterations in microglia with (I) ischemic stroke in general in the tMCAO (transient middle cerebral artery occlusion) mouse model of ischemic stroke, (II) the influence of LPS-preconditioning on microglial proteomic alterations after tMCAO and (III) the role of PI3Ky in the microglial proteomic changes after tMCAO and preconditioning. This was done by a single LPS injection 3 days before tMCAO in wildtype mice and mice with PI3Ky knockout or knockin of the kinase dead form of PI3Ky.
2024-03-22 | PXD031930 | 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: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 “resting” (or surveying) microglia to an “activated” (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.
2010-10-05 | GSE18602 | GEO
Project description:We subjected old (21-22 month) and young (3-4 month) male C57BL/6 mice to 45 min transient oclusion of the middle cerebral artery and obtained the brain four days later. We obtained bodipy+ microglia from the ischemic brain tissue by FACS.
2022-11-29 | GSE209732 | GEO
Project description:This project investigated responses of microglia in the mouse brain after an ischemic stroke. Mice were subjected to transient focal cerebral ischemia induced by 1 hour of left middle cerebral artery (MCA) occlusion followed by reperfusion. Control mice were subjected to sham surgery without the occlusion of the MCA. Three days after MCA occlusion or sham surgery, microglia were enriched from the brain by fluorescence-activated cell sorting and subjected to bulk RNA-seq. This project was closely related to our previously published dataset GSE141972; therefore, the animals had the same genetic background for comparison purposes. The animals used in this study were hemizygouse for CX3CR1(CreER), so that they can serve as wild-type controls for any conditional knockout driven by the CX3CR1(CreER) promoter.
2023-08-08 | GSE234865 | GEO
Project description:Modulating M1/M2 polarization is a potential therapy for treating ischemic stroke. Repetitive transcranial magnetic stimulation (rTMS) held the capacity to regulate astrocytic polarization, but little is known about rTMS effects on microglia. Therefore, the present study aimed to investigate whether and how rTMS influence microglia polarization in ischemic stroke models. The 10-Hz rTMS was applied to transient middle cerebral artery occlusion (MCAO) rats and oxygen and glucose deprivation/ reoxygenation injured BV2 cells. Western blot, immunofluorescence and ELISA were used to detect M1/M2 markers. High-throughput sequencing, RT-PCR and FISH staining were adopted to test microRNA changes. The 10-Hz rTMS inhibited ischemia/reperfusion induced M1 microglia and significantly increased let-7b-5p. HMGA2 was proved to be the target protein of let-7b-5p and its downstream NF-κB signaling pathway were inhibited by rTMS. Microglia culture medium (MCM) collected from rTMS treated microglia had low TNF-α but high IL-10 concentration, leading to reduced neural death, minor ischemic volumes and improved functional recovery of MCAO animals. However, knockdown of let-7b-5p by antagomir reversed rTMS effects on microglia. In conclusion, high-frequency rTMS could improve functional recovery through inhibiting M1 microglia polarization via regulating let-7b-5p/HMGA2/NF-κB signaling pathway in cerebral ischemic stroke models.
2022-08-10 | GSE192910 | GEO
Project description:RNA-Seq transcriptome comparison of the following cell populations (n=3-4 independent samples per cell population): a) CD11c-eYFP+ cells FACS sorted from brain of female adult mice 4 days after cerebral ischemia, b) CD11c-eYFP+ cells FACS sorted from brain of female parabiotic mice 4 days after cerebral ischemia c) CX3CR1+ microglia sorted from the ischemic brain of female CX3CR1CreERT2-ROSA26 tdTomato mice. Purpose: The goal of this study is to compare the transcriptome profile (RNA-Seq) of infiltrating cD11c-eYFP+ cells and microglia, both collected from ischemic brains of mice. Methods: RNA samples were obtained from FACS sorted eYFP+ cells of the ipsilateral brain hemisphere of CD11c-eYFP mice 4 days post-ischemia, the ipsilateral brain hemisphere of CD11c-eYFP/WT parabiotic mice 4 days post-ischemia, and from microglial cells sorted from the ipsilateral brain hemisphere of Cx3cr1CreERT2:ROSA26dTomato mice 4 days post-ischemia. NGS was performed (RNA-Seq) to compare the transcriptome of these populations. Results: the populations we compared clearly separated the differentially expressed genes in an unsupervised cluster analysis. 1509 genes were overrepresented in microglia and 1183 genes were overrepresented in CD11c-eYFP+ cells in the ischemic brain. Conclusions: Our study is the first comparative analysis of the transcriptomes of microglia and the infiltrating CD11c-eYFP+ cells derived from the ischemic brain of mice. The results show that the infiltrating CD11c-eYFP cell population in the ischemic brain tissue of parabiotic mice displays overrepresentation of genes typical of dendritic cells, immune functions, and ClassII antigen presentation, amongst others, that are not found represented in microglia.
2020-10-20 | GSE136855 | GEO
Project description:This data set shows dramatic changes in gene expression in microglia isolated from C57Bl6/J mice subjected to transient middle cerebral artery occlusion, as compared to those subjected to sham surgery. Mice deficient in Mincle (Clec4e-/-) showed significantly improved injury outcomes 3 and 7 days after transient middle cerebral artery occlusion. However, when comparing changes in gene expression in microglia 24 hours after blood reperfusion, there were no differences between wild-type and Clec4e-/- mice, indicating that Mincle does not participate in early microglial activation. Wild type and Mincle knock-out (Clec4e-/-) mice. After 1 h of transient middle cerebral artery occlusion (tMCAO) and 24 h of reperfusion, mice were perfused with PBS, their brains dissected, and 2 ipsilesional hemispheres (with cerebellum and brainstem removed) pooled for microglia isolation. For sham-operated animals, the whole forebrain was used and brains were not pooled. After myelin separation by Percoll gradient centrifugation, around 80,000 CD45intermediate, CD11b+ microglial cells were sorted from each sample. Sham samples n=3, tMCAO samples n=5.
2016-03-24 | E-GEOD-77986 | biostudies-arrayexpress
Project description:Microglia are resident myeloid cells in the central nervous system (CNS) that regulate homeostasis and protect CNS from damage and infection. The phenotype of microglia is critical in regulating the propagation and resolution of inflammatory responses after ischemic stroke. However, little is known of its complexity and heterogeneity in the above context. Here, using single-cell RNA sequencing (scRNA-seq) of over 11,000 cells from the mice ischemic brain tissues, we demonstrated a previously undefined molecular heterogeneity among microglia clusters following ischemic stroke.
2023-06-14 | GSE210986 | GEO
Project description:RNA-Seq transcriptome comparison of the following cell populations (n=4 independent samples per cell population): a) CD11c-eYFP+ cells FACS sorted from brain of adult mice 4 days after cerebral ischemia, b) CX3CR1+ microglia sorted from the ischemic brain of CX3CR1CreERT2-ROSA26 tdTomato mice; c) CD11c-rYFP+ cells sorted from the spleen of control mice; d) CX3CR1+ microglia sorted from the brain of control mice. Purpose: The goal of this study is to compare the transcriptome profile (RNA-Seq) of cD11c-eYFP+ cells and microglia, both collected from ischemic brains of mice, and with reference cell populations, i.e. Steady-stated microglia from brain of corresponding control mice and steady-state CD11c-eYFP cells sorted from the spleen of control mice. Methods: RNA samples were obtained from FACS sorted eYFP+ cells of the ipsilateral brain hemisphere of CD11c-eYFP mice 4 days post-ischemia, the spleen of control CD11c-eYFP mice, and from microglial cells sorted from control brain and the ipsilateral brain hemisphere 4 days post-ischemia of Cx3cr1CreERT2:ROSA26dTomato mice. NGS was perfomed (RNA-Seq) to compare the transcriptome of these populations. Results: the populations we compared clearly separated the differentially expressed genes in an unsupervised cluster analysis. 950 genes were overrepresented in microglia and 1469 genes were overrepresented in CD11c-eYFP+ cells in the ischemic brain. Conclusions: Our study is the first comparative analysis of the transcriptomes of microglia and the infiltrating CD11c-eYFP+ cells derived from the ischemic brain of mice. The results show that the infiltrating CD11c-eYFP cell population in the ischemic brain tissue of parabiotic mice displays overrepresentation of genes typical of dendritic cells, immune functions, and ClassII antigen presentation, amongst others, that are not found represented in microglia.
2020-10-20 | GSE136852 | GEO