Bace-1 inhibition facilitates the transition from homeostatic microglia to DAM-1
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PROVIDER: PRJNA851913 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Single-cell RNA sequencing data from purified mouse microglia with and without 5xFAD Alzheimer's disease model and with and without Bace-1 knockout
2022-06-22 | GSE199027 | GEO
Project description:BACE-1 is required for generating β-amyloid (Aβ) peptides in Alzheimer's disease (AD). Here, we report that microglial BACE-1 regulates the transition of homeostatic to stage 1 disease-associated microglia (DAM-1) signature. BACE-1 deficiency elevated levels of transcription factors including Jun, Jund, Btg2, Erg1, Junb, Fos, and Fosb in the transition signature, which transition from more homeostatic to highly phagocytic DAM-1. Consistently, similar transition-state microglia in human AD brains correlated with lowered levels of BACE-1 expression. Targeted deletion of Bace-1 in adult 5xFAD mice microglia elevated these phagocytic microglia, correlated with significant reduction in amyloid plaques without synaptic toxicity. Silencing or pharmacologically inhibiting BACE-1 in cultured microglia-derived cells shows higher phagocytic function in microglia. Mechanistic exploration suggests that abolished cleavage of IL-1R2 and Toll-like receptors via BACE-1 inhibition contributes to the enhanced signaling via the PI3K and p38 MAPK kinase pathway. Together, targeted inhibition of BACE-1 in microglia may offer AD treatment.
| S-EPMC9205595 | biostudies-literature
Project description:Microglia-mediated neuroinflammation has been implicated in the pathogenesis of Alzheimer's disease (AD). Although microglia in aging and neurodegenerative disease model mice show a loss of homeostatic phenotype and activation of disease-associated microglia (DAM), a correlation between those phenotypes and the degree of neuronal cell loss has not been clarified. In this study, we performed RNA sequencing of microglia isolated from three representative neurodegenerative mouse models, AppNL-G-F/NL-G-F with amyloid pathology, rTg4510 with tauopathy, and SOD1G93A with motor neuron disease by magnetic activated cell sorting. In parallel, gene expression patterns of the human precuneus with early Alzheimer's change (n=11) and control brain (n=14) were also analyzed by RNA sequencing. We found that a substantial reduction of homeostatic microglial genes in rTg4510 and SOD1G93A microglia, whereas DAM genes were uniformly upregulated in all mouse models. The reduction of homeostatic microglial genes was correlated with the degree of neuronal cell loss. In human precuneus with early AD pathology, reduced expression of genes related to microglia- and oligodendrocyte-specific markers was observed, although the expression of DAM genes was not upregulated. Our results implicate a loss of homeostatic microglial function in the progression of AD and other neurodegenerative diseases. Moreover, analyses of human precuneus also suggest loss of microglia and oligodendrocyte functions induced by early amyloid pathology in human.
2023-07-09 | GSE236268 | GEO
Project description:Microglia are resident immune cells of the brain and regulate its inflammatory state. In neurodegenerative diseases, microglia transition from a homeostatic state to a state referred to as disease associated microglia (DAM). DAM express higher levels of proinflammatory signaling molecules, like STAT1 and TLR2, and show transitions in mitochondrial activity toward a more glycolytic response. Inhibition of Kv1.3 decreases the proinflammatory signature of DAM, though how Kv1.3 influences the response is unknown. Our goal was to establish the potential proteins interacting with Kv1.3 during transition to DAM. We utilized TurboID, a biotin ligase, fused to Kv1.3 to evaluate the potential interacting proteins with Kv1.3 via mass spectrometry in BV-2 microglia following TLR4-mediated activation. Electrophysiology, western blotting, and flow cytometry were used to evaluate Kv1.3 channel presence and TurboID biotinylation activity. We hypothesized that Kv1.3 contains domain-specific interactors that vary during a TLR4-induced inflammatory response, some of which are dependent on the PDZ-binding domain on the C-terminus. We determined that the N-terminus of Kv1.3 is responsible for trafficking Kv1.3 to the cell surface and mitochondria (e.g. NUNDC, TIMM50). Whereas, the C-terminus interacts with immune signaling proteins in an LPS-induced inflammatory response (e.g. STAT1, TLR2, and C3). There are 70 proteins that rely on the C-terminal PDZ-binding domain to interact with Kv1.3 (e.g. ND3, Snx3, and Sun1). Overall, we highlight that the Kv1.3 potassium channel functions beyond conducting the outward flux of potassium ions in an inflammatory context and that KV1.3 modulates activity of key immune signaling proteins, such as STAT1 and C3
2024-05-06 | PXD049433 | Pride
Project description:Microglia have important remodeling functions in development and disease. There is evidence for molecular diversity of microglia suggesting they may exist in distinct functional states to differentially impact CNS health and function. To better understand this in development, we profiled microglia of a discrete developing CNS region, the murine retina. We find that retinal microglia transition through unique transcriptional states and identify a population with peak density postnatally that resemble adult disease-associated microglia (DAM) and CD11c+ microglia of developing white matter, we term DAM-like. Developmental cell death is a major driver of the DAM-like phenotype, and TREM2 signaling is required for select DAM gene expression. Notably, DAM-like cells that highly express CD11c are not dependent on CSF1R signaling for survival, and TREM2 signaling is required for CSF1R independence in a subset of microglia. Thus, microglial phenotype in development is influenced by local developmental events and may share features with microglia in disease.
2019-06-10 | GSE123757 | GEO
Project description:Microglia are resident myeloid cells of the central nervous system (CNS). Recently, single-cell RNA sequencing (scRNAseq) has enabled description of a disease-associated subtype of microglia (DAM) with a role in neurodegeneration and demyelination. In this study we use scRNAseq to investigate the temporal dynamics of immune cells harvested from the epicenter of traumatic spinal cord injury (SCI). As a consequence of SCI, homeostatic microglia undergo permanent transcriptional re-programming into a subtype of microglia with striking similarities to previoysly reported DAM as well as a distinct microglial state found during development. Using a microglia depletion model we showed that DAM in SCI are derived from homeostatic microglia and strongly enhance recovery of hind limb locomotor function following injury.
2021-12-24 | GSE142849 | GEO
Project description:To address the question of whether γ-secretase deficiency affects the tonic signaling in microglia in vivo as well, we analyzed the single-cell transcriptomes of the γ-secretase deficient microglia from WT and AD mouse models at 3 ,6 and 7 months of age. Like the in vitro observations, genetic knockout of γ-secretase induced mild changes to the transcriptomes of in vivo microglia in the WT mice and also AD mice at 3 months. However, The relative proportions of DAM, CRM and TRM were significantly reduced in AppNL-G-F-GSiΔMG mice compared to AppNL-G-F-GSWT mice at 7 months, whereas HM and tCRM were significantly increased. Thus γ-secretase has a crucial role in the microglial transition from the homeostatic to the full DAM phenotype in AD.
2023-10-20 | GSE245391 | GEO
Project description:γ-Secretase is involved in the regulated intramembrane proteolysis (RIP) of a variety of integral membrane proteins and generates the amyloid peptide (Aβ) in Alzheimer’s Disease (AD). Microglia are centrally involved in AD, but the substrates and function of γ-secretase in these cells remain largely unstudied. Using a novel γ-Secretase Substrate Identification (G-SECSI) method, we identified 85 substrates, of which 59 were previously unknown, in stem cell derived microglia-like cells. More than 60% of those are signalling receptors possibly involved in cell state regulation. Inhibition of γ-secretase using Semagacestat or selective genetic knockout alters the expression of homeostatic (HM) and disease-associated (DAM) genes, in particular when microglia are exposed to amyloid plaques in vivo. Thus, γ-secretase regulates tonic signaling via a spectrum of substrates in microglia in steady state, and its blockage results in the defective transition to the DAM response in AD.
2023-11-14 | PXD039238 | Pride
Project description:APOE4 retinal microglia remain homeostatic in glaucoma.
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Project description:Microglial reactivity to injury and disease is emerging as a heterogeneous, dynamic, and crucial determinant in neurological disorders. However, the plasticity and ultimate fate of disease-associated microglia (DAM) remains largely unknown. We established a lineage tracing system, leveraging the expression dynamics of Spp1, which allows for genetic labeling of DAM-like microglia and tracking their behavior during brain injury and recovery. Fate-mapping of Spp1+ microglia in juvenile stroke revealed an irreversible state of reactive microglia that are ultimately eliminated from the injured brain. In contrast, DAM-like microglia in the neonatal context exhibit high plasticity, capable of regaining a homeostatic signature and integrating into the global microglial network after recovery. Furthermore, neonatal injury has a lasting impact on microglia, rendering them intrinsically sensitized to subsequent immune challenges. Therefore, by unraveling the fate of DAM-like microglia in various neuropathological conditions, our work highlights the exceptional plasticity and innate immune memory of neonatal microglia.
2024-01-24 | GSE247391 | GEO