Microglia innate immune memory is retained after enforced repopulation [RNA-seq]
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PROVIDER: PRJNA1132173 | ENA |
REPOSITORIES: ENA
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Project description:Microglia innate immune memory is retained after enforced repopulation [ATAC-seq]
| PRJNA1129070 | ENA
Project description:Microglia are crucial for CNS homeostasis and involved in a wide range of neurodegenerative and neuroinflammatory diseases. Systemic inflammation and infections can contribute to neurodegeneration later in life by affecting microglia. Like other innate immune cells, microglia can develop innate immune memory in response to a challenge, altering their response to future stimuli. Innate immune memory can ameliorate or worsen CNS pathology, but its persistence is unclear. Recently, several methods have been developed to stimulate microglia turnover. Here, we investigated whether colony-stimulating factor 1 (CSF1R)-dependent microglia depletion followed by repopulation reversed microglial tolerance to systemic inflammation in mice. Repopulated microglia displayed a reduced expression of homeostatic genes and genes related to mitochondrial respiration and TCA cycle metabolism and an increased expression of immune effector and activation genes. Nonetheless, the blunted inflammatory gene expression induced by the LPS-preconditioning was retained after a depletion-repopulation cycle. Our study highlights the persistence of epigenetic changes underlying microglial tolerance and indicates potential implications of microglia depletion and repopulation therapies on microglia functions.
2025-05-01 | GSE271535 | GEO
Project description:Microglia are crucial for CNS homeostasis and involved in a wide range of neurodegenerative and neuroinflammatory diseases. Systemic inflammation and infections can contribute to neurodegeneration later in life by affecting microglia. Like other innate immune cells, microglia can develop innate immune memory in response to a challenge, altering their response to future stimuli. Innate immune memory can ameliorate or worsen CNS pathology, but its persistence is unclear. Recently, several methods have been developed to stimulate microglia turnover. Here, we investigated whether colony-stimulating factor 1 (CSF1R)-dependent microglia depletion followed by repopulation reversed microglial tolerance to systemic inflammation in mice. Repopulated microglia displayed a reduced expression of homeostatic genes and genes related to mitochondrial respiration and TCA cycle metabolism and an increased expression of immune effector and activation genes. Nonetheless, the blunted inflammatory gene expression induced by the LPS-preconditioning was retained after a depletion-repopulation cycle. Our study highlights the persistence of epigenetic changes underlying microglial tolerance and indicates potential implications of microglia depletion and repopulation therapies on microglia functions.
2025-05-01 | GSE270935 | GEO
Project description:Although most tissue macrophages are embryonically derived it is evident that circulating monocytes can compete for virtually any macrophage niche. Monocytes can thus become long-lived replacements of tissue macrophages that are indistinguishable from their embryonic counterparts, but the factors regulating this process are incompletely understood. To study niche competition in the CNS we depleted microglia with >95% efficiency using CX3CR1CreER/+R26DTA/+ mice and monitored long-term repopulation. The microglial niche was repopulated within weeks by a combination of local microglia proliferation giving rise to CX3CR1+F4/80lowClec12a– microglia, as well as infiltration of CX3CR1+F4/80hiClec12a+ macrophages. Adoptive transfer experiments demonstrated that peripherally-derived macrophages arose directly from Ly6Chi monocytes without contribution from hematopoietic progenitors and was independent of BBB breakdown. After repopulation we sorted microglia and monocyte-derived macrophages and performed transcriptional, epigenetic (DNA methylation) and ex vivo functional profiling. This revealed that Ly6Chi monocytes upregulated microglia gene expression and adopted microglia DNA methylation signatures. However, in contrast to proliferating microglia, which rapidly regained their homeostatic gene signature, monocyte-derived macrophages retained a distinct gene signature associated with antigen presentation, interferon signaling and chemotaxis. This translated into functional changes in monocyte-derived macrophages, as demonstrated by differences in surface marker expression, phagocytosis and cytokine production. Our results demonstrate that monocytes are imprinted by the CNS microenvironment but remain transcriptionally, epigenetically and functionally distinct. This may have implications for neuroinflammatory disease states and direct design of novel therapies.
2018-10-19 | GSE121409 | GEO
Project description:Although most tissue macrophages are embryonically derived it is evident that circulating monocytes can compete for virtually any macrophage niche. Monocytes can thus become long-lived replacements of tissue macrophages that are indistinguishable from their embryonic counterparts, but the factors regulating this process are incompletely understood. To study niche competition in the CNS we depleted microglia with >95% efficiency using CX3CR1CreER/+R26DTA/+ mice and monitored long-term repopulation. The microglial niche was repopulated within weeks by a combination of local microglia proliferation giving rise to CX3CR1+F4/80lowClec12a– microglia, as well as infiltration of CX3CR1+F4/80hiClec12a+ macrophages. Adoptive transfer experiments demonstrated that peripherally-derived macrophages arose directly from Ly6Chi monocytes without contribution from hematopoietic progenitors and was independent of BBB breakdown. After repopulation we sorted microglia and monocyte-derived macrophages and performed transcriptional, epigenetic (DNA methylation) and ex vivo functional profiling. This revealed that Ly6Chi monocytes upregulated microglia gene expression and adopted microglia DNA methylation signatures. However, in contrast to proliferating microglia, which rapidly regained their homeostatic gene signature, monocyte-derived macrophages retained a distinct gene signature associated with antigen presentation, interferon signaling and chemotaxis. This translated into functional changes in monocyte-derived macrophages, as demonstrated by differences in surface marker expression, phagocytosis and cytokine production. Our results demonstrate that monocytes are imprinted by the CNS microenvironment but remain transcriptionally, epigenetically and functionally distinct. This may have implications for neuroinflammatory disease states and direct design of novel therapies. Data was processed using the mEPIC tool PMID:29141580
2018-10-19 | GSE121483 | GEO
Project description:In this study, we aimed to deplete the aging microglia and investigate the impact of the newly-born microglia in Alzheimer's pathology using the 3xTg mouse model. Specifically, >24 mo male 3xTg mice were given chow containing 1200mg/kg PLX5622 (AIN-76A-D1001i, Research Diests, NJ, USA) for 2 weeks to deplete their microglia. Control diet with the same base formula were given to control group and to experimental groups during a 4-week repopulation phase immediately following PLX treatment. At the end of the repopulation, we pooled sorted, viable microglia (CD45int CD11b) from 3-5 mice/group and ran single-cell RNAseq analysis to determine the similarities and differences between the aged and repopulated cells in the context of Alzheimer's Disease. We also included non-transgenic controls as a separate group.
2022-02-01 | GSE190607 | GEO
Project description:During early embryogenesis microglia arise from yolk sac progenitors populating the developing CNS, where they are maintained as tissue-resident macrophages throughout the organism’s lifespan. Here, we describe an experimental system that allows the specific conditional ablation of microglia in vivo. Strikingly, we found that the microglia compartment was reconstituted within one week following depletion. Microglia repopulation relied entirely on a CNS-resident, internal pool and was independent from bone marrow-derived precursors. Newly formed microglia were found in highly proliferative, organized micro-clusters that dissolve once steady state was achieved. Gene expression profiling revealed prominent expression of Interleukin-1 (IL-1) receptor in proliferating microglia. During the repopulation phase, IL-1 signaling was neutralized by treatment with IL-1 receptor antagonist that impaired microglia proliferation. Hence, microglia harbor a highly efficient potential to restore themselves without contribution of peripheral myeloid cells. IL-1 signaling significantly participates in this restorative proliferation process and is involved in stabilizing microglia maintenance. bone marrow macrophages, wild type microglia, and repopulating microglia
2015-07-15 | E-GEOD-68376 | biostudies-arrayexpress
Project description:Cx3cr1CreER-Eyfp/wt mice contain a subset of microglia lacking Cre and EYFP expression. These microglial escape Cre-mediated recombination and gain a repopulation advantage following Cre-driven DTA-mediated microglial depletion.
2022-02-01 | GSE186700 | GEO
Project description:To determine the transcriptomic changes underlying the MIA microglia phenotype and their reversal by PLX, we performed RNA-sequencing of magnetic CD11B beads-isolated microglia from the whole brain in Saline and MIA male and female offspring at E17, P7, P20, and P60, as well as from MG-REP male and female offspring at P60. Microglial transcriptome reveals novel MIA and repopulation modules and overlap of MIA microglial genes with ASD gene network. 14,225 microglial genes from RNA-seq data revealed distinct transcriptional signatures of immature microglia (IM module, 4681 transcripts, enriched in E17 and P7 Saline), MIA immature microglia (MIA-IM module, 2816 transcripts, enriched in E17 and P7 MIA), Juvenile microglia (JM module, 2318 transcripts, enriched in P20 Saline and MIA), Adult microglia (AM module, 3276 transcripts, enriched in P60 Saline + CTRL, P60 MIA + CTRL and P60 MIA + MG-REP), and repopulated adult microglia (REP-AM module, 1,134 transcripts, enriched in P60 Saline + MG-REP)
2020-03-06 | GSE146526 | GEO
Project description:Over the past decade, genetic evidence has demonstrated that microglial dysregulation is likely to play a central role in the development of Alzheimer's disease (AD). As resident immune cells in the brain, microglia become dystrophic and senescent during the chronic progression of AD. To explore whether replenishing the brain with new microglia is beneficial to AD, we employed a CSF1R inhibitor PLX3397 to deplete microglia and induce repopulation after the inhibitor withdrawal in 5xFAD transgenic mice. We observed that microglial repopulation ameliorates AD-associated cognitive deficits, accompanied by elevation of synaptic proteins and hippocampal long-term potentiation (LTP). In addition, microglial morphology is restored after microglial self-renewal, and amyloid pathology is reduced with long-term repopulation but not short-term. Transcriptome analysis showed that repopulating microglia in 5xFAD mice recovers a gene expression profile that is highly similar to microglia from WT mice. Notably, the neurotrophic signaling pathway and hippocampal neurogenesis dysregulated in the AD brain are restored after microglial replenishment. At last, we confirmed that microglial repopulation rescues brain-derived neurotrophic factor (BDNF) expression to contribute to synaptic plasticity. Together, we conclude that microglial self-renewal benefits AD brain by restoring the BDNF neurotrophic signaling pathway. Thus, the proper replenishment of microglia may be an effective and novel therapeutic strategy for ameliorating cognition impairment in AD.
2023-07-24 | GSE223156 | GEO