The Gain-of-Function TREM2-T96K Mutation Increases Risk for Alzheimer’s Disease by Impairing Microglial Function
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE307564 | GEO | 2025/09/17
REPOSITORIES: GEO
Similar Datasets
Project description:The aim of this study is to characterize the underlying molecular mechanisms of the gain-of-function Trem2T96K mutation in Alzheimer’s disease (AD) pathogenesis by using the constitutive Trem2T96K knock-in mouse crossed to the 5xFAD mouse model of AD. By transcriptional single cell sorting, we comprehensively mapped all microglial populations in 8-month-old female 5xFAD;Trem2+/+, 5xFAD;Trem2T96K/+, and 5xFAD;Trem2T96K/T96K mice. Single-cell RNA-seq analysis revealed that Trem2T96K leads to concomitant suppression of the disease-associated microglia (DAM) gene signature and activation of homeostatic (HOM) genes and impairs the transition of HOM microglia into DAM in female 5xFAD mice. Collectively, these results suggest that Trem2T96K leads to reduced microglial immune activation in female 5xFAD mice.
2025-09-17 | GSE307686 | GEO
Project description:We examined the role of TREM2 on microglia responses to amyloid-beta deposition in a mouse model of Alzheimer's disease Microglia were FACS-purified from 8.5 month old WT, Trem2-/-, 5XFAD, and Trem2-/- 5XFAD mice
2015-03-13 | E-GEOD-65067 | biostudies-arrayexpress
Project description:The hemizygous R47H variant of TREM2, a microglia-specific gene in the brain, increases risk for late-onset Alzheimer’s disease (AD). Using transcriptomic analysis at the single-nuclei level from brain tissue of AD patients with the R47H mutation or the common variant (CV)-TREM2, we found that R47H-associated microglial subpopulations had enhanced inflammatory signatures reminiscent of previously-identified disease-associated microglia (DAM) and hyperactivation of AKT, one of the signaling pathways downstream of TREM2. We established a tauopathy mouse model with heterozygous knock-in of the human TREM2 with R47H mutation or CV, and found that R47H induced and exacerbated tau-mediated spatial memory deficits in female mice. Single-cell transcriptomic analysis of microglia from these mice also revealed transcriptomic changes induced by R47H that had significant overlaps with R47H microglia in human AD brains, including robust increases in proinflammatory cytokines, activation of Akt signaling, and elevation of a subset of disease-associated microglial signatures. Pharmacological Akt inhibition with MK-2206 largely reversed the enhanced inflammatory signatures in primary R47H microglia treated with tau fibrils. Strikingly, in R47H heterozygous tauopathy mice, MK-2206 treatment abolished a tauopathy-dependent microglial subcluster, and rescued tauopathy-induced synapse loss. By uncovering disease-enhancing mechanisms of the R47H mutation conserved in human and mouse, our study supports inhibitors of AKT signaling as a novel microglial modulating strategy to treat AD.
2021-12-06 | GSE140670 | GEO
Project description:The hemizygous R47H variant of TREM2, a microglia-specific gene in the brain, increases risk for late-onset Alzheimer’s disease (AD). Using transcriptomic analysis at the single-nuclei level from brain tissue of AD patients with the R47H mutation or the common variant (CV)-TREM2, we found that R47H-associated microglial subpopulations had enhanced inflammatory signatures reminiscent of previously-identified disease-associated microglia (DAM) and hyperactivation of AKT, one of the signaling pathways downstream of TREM2. We established a tauopathy mouse model with heterozygous knock-in of the human TREM2 with R47H mutation or CV, and found that R47H induced and exacerbated tau-mediated spatial memory deficits in female mice. Single-cell transcriptomic analysis of microglia from these mice also revealed transcriptomic changes induced by R47H that had significant overlaps with R47H microglia in human AD brains, including robust increases in proinflammatory cytokines, activation of Akt signaling, and elevation of a subset of disease-associated microglial signatures. Pharmacological Akt inhibition with MK-2206 largely reversed the enhanced inflammatory signatures in primary R47H microglia treated with tau fibrils. Strikingly, in R47H heterozygous tauopathy mice, MK-2206 treatment abolished a tauopathy-dependent microglial subcluster, and rescued tauopathy-induced synapse loss. By uncovering disease-enhancing mechanisms of the R47H mutation conserved in human and mouse, our study supports inhibitors of AKT signaling as a novel microglial modulating strategy to treat AD.
2021-12-06 | GSE136389 | GEO
Project description:Triggering receptor expressed on myeloid cells 2 (TREM2) sustains microglia response to brain injury stimuli including apoptotic cells, myelin damage, and amyloid β (Aβ). Alzheimer’s Disease (AD) risk is associated with the TREM2R47H variant, which impairs ligand binding and consequently microglia responses to Aβ pathology. Here we tested whether TREM2 engagement by an agonistic mAb, hT2AB, designated as a surrogate ligand facilitates microglia responses in 5XFAD transgenic mice that accumulate Aβ and express either the common TREM2 variant (TREM2CV) or TREM2R47H. scRNA-seq of microglia from TREM2CV-5XFAD mice treated once with control IgG exposed trajectories representative of activated microglial populations including disease-associated microglia (DAM), interferon-responsive (IFN-R), cycling (Cyc-M), and MHC-II expressing (MHC-II) microglia. All of these were underrepresented in TREM2R47H-5XFAD mice, suggesting that TREM2 ligand engagement is required for microglia transitions. Moreover, Cyc-M and IFN-R microglia were better represented in female than male TREM2CV-5XFAD mice, likely reflecting a greater Aβ load in female 5XFAD mice. A single systemic injection of hT2AB replenished the Cyc-M, IFN-R, and MHC-II pools in TREM2R47H-5XFAD mice. In TREM2CV-5XFAD mice, however, hT2AB brought the representation of male Cyc-M and IFN-R microglia closer to that of females, in which microglia transitions in response to Aβ had already reached their peak. Repeated treatment with a murinized version mT2AB over a 10 days period increased brain content of chemokines in TREM2R47H-5XFAD mice, consistent with microglia expansion and shifts in gene expression patterns. Thus, the impact of hT2AB on microglia responses is shaped by the extent of TREM2 endogenous ligand engagement and basal microglia activation.
2020-12-08 | GSE156183 | GEO
Project description:The most common form of senile dementia, Alzheimer’s disease (AD), is characterized by Aβ plaques and neurofibrillary tangles in the CNS. AD genetic studies have identified high-risk hypomorphic variants in TREM2, a myeloid cell surface receptor that enables concerted microglial responses to Aβ plaques and neuronal cell death, including proliferation, survival, clustering and phagocytosis. How TREM2 promotes these responses is not known. Here, we demonstrate that TREM2 drives mTOR signaling, which maintains high ATP levels, supports biosynthetic pathways and suppresses AMPK phosphorylation and autophagy. In vitro, TREM2-deficient macrophages undergo dramatically increased autophagy and die in response to growth factor limitation or ER stress. Excessive autophagy is also evident in microglia from Trem2-/- 5XFAD mice and in post-mortem specimens from AD patients carrying TREM2 risk variants. Metabolic derailment, autophagy and cell death can be circumvented by engaging alternative energy production pathways. Thus, restoring microglial energetic and anabolic levels may be a future therapeutic avenue for TREM2-associated neurological disease.
2017-08-15 | GSE98563 | GEO
Project description:CD33-/- and/or TREM2-/- mice were crossed with the 5xFAD mouse model of Alzheimer’s disease to generate single and double CD33/TREM2 knock-out mice on 5xFAD background. Transcriptome and gene expression analyses were performed to analyze the impact of CD33 and/or TREM2 knock-out on the transcriptome of microglia in the context of amyloid pathology. The results revealed that CD33 and/or TREM2 knock-out reprogrammed microglial gene expression signatures in 5xFAD mice in an age-dependent manner. Differential gene expression in 5xFAD;CD33-/- microglia depended on the presence of TREM2. These data suggest that TREM2 acts downstream of CD33.
2019-06-11 | GSE132508 | GEO
Project description:The hemizygous R47H variant of TREM2, a microglia-specific gene in the brain, increases risk for late-onset Alzheimer’s disease (AD). In this study, we identified a subpopulation of microglia with disease-enhancing proinflammatory signatures associated with the R47H mutation in human AD brains and tauopathy mouse brains. Using transcriptomic analysis at the single-nuclei level from AD patients with the R47H or the common variant (CV)-TREM2 with matched sex, pathology and clinical dementia status, we found that the R47H mutation was associated with cell type- and sex-specific transcriptional changes in human AD brains. Further characterization of microglia revealed that R47H-associated microglial subpopulations had enhanced inflammatory signatures reminiscent of previously-identified disease-associated microglia (DAM) and hyperactivation of AKT, one of the signaling pathways downstream of TREM2. In a newly-generated tauopathy knock-in mouse model expressing one allele of human TREM2 (hTREM2) with either the R47H mutation or CV, R47H induced and exacerbated tau-mediated spatial memory deficits in female mice. Single-cell transcriptomic analysis of microglia from these mice also revealed transcriptomic changes induced by R47H that had significant overlaps with R47H microglia in human AD brains, including robust increases in proinflammatory cytokines, activation of Akt-signaling, and elevation of a subset of disease-associated microglial signatures. Strikingly, pharmacological Akt inhibition largely reversed the enhanced inflammatory signatures induced by R47H in primary microglia treated with tau fibrils as well as rescued the tauopathy-induced synapse loss in R47H heterozygous mice. By unraveling the disease-enhancing properties of the R47H mutation in mouse and human, our findings shed light on an immune-linked AD subtype and provide new directions for modulating microglial immune responses to treat AD.
2021-08-18 | GSE181903 | GEO
Project description:The hemizygous R47H variant of TREM2, a microglia-specific gene in the brain, increases risk for late-onset Alzheimer’s disease (AD). To understand its pathogenicity, we performed single-nuclei RNA-sequencing of cortical tissue from AD patients with R47H or the common variant (CV)-TREM2 with matched sex, pathology and APOE status. we found that the R47H mutation is associated with cell type- and sex-specific transcriptional changes in human AD, with microglia exhibiting the most robust alterations. R47H-associated microglial subpopulations were characterized by hyperactivation of AKT, one of the signaling pathways downstream of TREM2, and enhanced inflammatory signatures. In tauopathy mouse models that carry one allele of human TREM2 (hTREM2) with either the R47H mutation or CV, the mutation induced spatial memory deficits and exacerbated tau-mediated deficits in female mice. Similar to the human data, the disease-enhancing effects of R47H microglia were associated with robust increases in proinflammatory cytokines, Syk-Akt-signaling, and elevation of a subset of disease-associated microglial signatures identified using single-cell sequencing from isolated microglia. Pharmacological Akt inhibition largely reversed the enhanced inflammatory signatures in R47H microglia treated with tau fibrils. By unraveling the disease-enhancing properties of the R47H mutation in mouse and human, our findings shed light on an immune-linked AD subtype and provide new directions for modulating brain immune responses to treat AD.
2022-07-16 | GSE154578 | GEO
Project description:Microglia and monocyte-derived macrophages (MDM) are key players in coping with Alzheimer's disease (AD). In amyloidosis mouse models, activation of microglia was found to be TREM2-dependent. Here, using Trem2-/-5xFAD mice, we assessed whether MDM act via a TREM2-dependent pathway. We adopted a treatment protocol targeting the programmed cell death ligand-1 (PD-L1) immune checkpoint, previously shown to modify AD via MDM involvement. Blocking PD-L1 in Trem2-/-5xFAD mice resulted in cognitive improvement and reduced levels of water-soluble amyloid beta (Aβ)1-42 with no effect on amyloid plaque burden. Single-cell RNA sequencing revealed that MDM, derived from both Trem2-/- and Trem2+/+5xFAD mouse brains, express a unique set of genes encoding scavenger receptors (e.g. Mrc1, Msr1). Blocking monocytes trafficking using anti-CCR2 antibody completely abrogated the cognitive improvement induced by anti-PD-L1 in Trem2-/-5xFAD mice, and similarly but to lower extent in Trem2+/+5xFAD mice. These results highlight a TREM2-independent disease-modifying activity of MDM in amyloidosis mouse model.
2021-10-24 | GSE176085 | GEO