Microglia Depletion Reduces Human Neuronal APOE4-Driven Pathologies in a Chimeric Alzheimer’s Disease Model
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA1041411 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Despite strong evidence supporting the involvement of both apolipoprotein E4 (APOE4) and microglia in Alzheimer’s Disease (AD) pathogenesis, the effects of microglia on neuronal APOE4-driven AD pathogenesis remain elusive. Here, we examined such effects utilizing microglial depletion in a chimeric model with human neurons in mouse hippocampus. Specifically, we transplanted homozygous APOE4, isogenic APOE3, and APOE-knockout (APOE-KO) induced pluripotent stem cell (iPSC)-derived human neurons into the hippocampus of human APOE3 or APOE4 knock-in mice, and depleted microglia in half the chimeric mice. We found that both neuronal APOE and microglial presence were important for the formation of Aβ and tau pathologies in an APOE isoform-dependent manner (APOE4 > APOE3). Single-cell RNA-sequencing analysis identified two pro-inflammatory microglial subtypes with high MHC-II gene expression that are enriched in chimeric mice with human APOE4 neuron transplants. These findings highlight the concerted roles of neuronal APOE, especially APOE4, and microglia in AD pathogenesis.
2024-10-25 | GSE248020 | GEO
Project description:Despite its clear impact on Alzheimer’s Disease (AD) risk, apolipoprotein (apo) E4’s contributions to AD etiology remain poorly understood. Progress in answering this and other questions in AD research has been limited by an inability to model human-specific phenotypes in an in vivo environment. Here we transplanted human induced pluripotent stem cell (hiPSC)-derived neurons carrying normal apoE3 or pathogenic apoE4 into human apoE3 or apoE4 knock-in mouse hippocampi, enabling us to disentangle the effects of apoE4 produced in human neurons and in the brain environment. Using single nucleus RNA-sequencing (snRNA-seq), we identified key transcriptional changes specific to human neuron subtypes in response to endogenous or exogenous apoE4. We also found that Aβ from transplanted human neurons formed plaque-like aggregates, with differences in localization and interaction with microglia depending on the transplant and host apoE genotype. These findings highlight the power of in vivo chimeric disease modeling for studying AD.
2020-06-20 | GSE152867 | GEO
Project description:Apolipoprotein E4 (APOE4) is the strongest known genetic risk factor for late-onset Alzheimer’s disease (AD). Conditions of stress or injury induce APOE expression within neurons, but the exact roles of neuronal APOE4 in AD pathogenesis are still unclear. Here we report a rigorous characterization of neuronal APOE4 effects on prominent AD-related pathologies by selectively removing APOE4 from neurons in an APOE4-expressing tauopathy mouse model. We found that the removal of neuronal APOE4 led to a drastic reduction in Tau pathology accumulation and spread, gliosis, neurodegeneration, neurodysfunction, and myelin deficits in this tauopathy mouse model. Single-nucleus RNA-sequencing revealed that the removal of neuronal APOE4 greatly diminished neurodegenerative disease-associated subpopulations of neurons, oligodendrocytes, astrocytes, and microglia that were enriched in APOE4-expressing tauopathy mice and whose accumulation correlated to the severity of Tau pathology, neurodegeneration, and myelin deficits. Thus, neuronal APOE4 plays a central role in promoting the development of major AD pathologies and its removal can effectively combat APOE4-driven effects in AD and other tauopathies.
2023-01-06 | GSE221215 | GEO
Project description:Apolipoprotein E4 (APOE4) is the strongest genetic risk factor for late-onset Alzheimer’s disease (LOAD), leading to earlier age of clinical onset and exacerbating pathologies. There is a critical need to identify protective targets. Recently, a rare APOE variant, APOE3-R136S (Christchurch), was found to protect against early-onset AD in a PSEN1-E280A carrier. We sought to determine if the R136S mutation also protects against APOE4-driven effects in LOAD. We generated tauopathy mouse and human iPSC-derived neuron models carrying human APOE4 with the homozygous or heterozygous R136S mutation. We found that the homozygous R136S mutation rescued APOE4-driven Tau pathology, neurodegeneration, and neuroinflammation. The heterozygous R136S mutation partially protected against APOE4-driven neurodegeneration and neuroinflammation, but not Tau pathology. Single-nucleus RNA-sequencing revealed that the APOE4-R136S mutation increased disease-protective and diminished disease-associated cell populations in a gene dose-dependent manner. Thus, the APOE-R136S mutation protects against APOE4-driven AD pathologies, providing a target for therapeutic development against AD.
2023-09-21 | GSE217854 | GEO
Project description:Apolipoprotein E4 (APOE4) is an important driver of Tau pathology, gliosis, and degeneration in Alzheimer’s disease (AD). Still, the mechanisms underlying these APOE4-driven pathological effects remain elusive. In this study, we demonstrated in a tauopathy mouse model that APOE4 promoted the nucleo-cytoplasmic translocation and release of high mobility group box 1 (HMGB1) from hippocampal neurons, which correlated with the severity of hippocampal microgliosis and degeneration. Injection of HMGB1 into the hippocampus of young APOE4-tauopathy mice induced considerable and persistent gliosis. Selective removal of neuronal APOE4 reduced the nucleo-cytoplasmic translocation and release of HMGB1. Therapeutic treatment of APOE4-tauopathy mice with HMGB1 inhibitors effectively blocked the intraneuronal translocation and release of HMGB1 and ameliorated the development of prominent APOE4-driven AD pathologies, including gliosis, Tau pathology, neurodegeneration, and myelin deficits. Single-nucleus RNA-sequencing revealed that treatment with HMGB1 inhibitors diminished disease-associated and enriched disease-protective subpopulations of neurons, microglia, and astrocytes in APOE4-tauopathy mice. Thus, HMGB1 inhibitors represent a promising approach for treating APOE4-related AD.
2023-09-01 | GSE242153 | GEO
Project description:The development of treatment for Alzheimer’s Disease (AD) is hindered by a limited understanding of its structural basis. Apolipoprotein E (APOE) ε4 genotype is the most important risk factor for late-onset AD. APOE4 differs from the APOE3 isoform by a single mutation, C112R. Here, we employ crystallography, biophysical methods and computer simulations to dissect the “domino-like” effect of C112R substitution on APOE4 behaviour. We found that the mutation induces long-distance (>15 Å) conformational changes leading to geometrically distinct T-shaped dimeric unit of APOE4 compared to APOE3. By mutagenesis, we demonstrate that the APOE4 unit is more prone to aggregation than that of the APOE3. AD drug candidate tramiprosate and metabolite 3-sulfopropanoic acid induce APOE3-like conformational behaviour in APOE4 and suppress its aggregation propensity. Omics analysis of APOE ε4/ε4 cerebral organoids treated with tramiprosate revealed its effect on cholesteryl esters, the storage product of excess cholesterol. Our results connect the APOE4 structure with its aggregation propensity, which can be further exploited in drug development for neurodegeneration and ageing.
2023-07-20 | PXD036416 | Pride
Project description:APOE4 genotype is the strongest risk factor for the pathogenesis of sporadic Alzheimer’s disease (AD), but the detailed molecular mechanism of APOE4-mediated synaptic impairment remains to be determined in human cellular context. In this study, we generated human astrocyte model carrying APOE3 or APOE4 genotype using human induced pluripotent stem cells (iPSCs), in which isogenic APOE4 iPSCs were genome-edited from healthy control APOE3 iPSCs. By transcriptome analysis of human astrocytes between APOE genotypes, we showed the upregulation of an extracellular matrix glycoprotein in human APOE4 astrocytes, which may cause synaptic degeneration in concert with the equivocal reactive character and lipid change. Together, these results demonstrate novel negative impact of human APOE4 astrocyte on synaptic integrity and lead to a promising therapeutic intervention into APOE4-carriers.
2023-08-31 | GSE206314 | GEO
Project description:The Apolipoprotein E4 (ApoE4) allele is one of the strongest risk factors for late-onset Alzheimer’s disease (AD) and is associated with a breakdown of the blood-brain barrier and vascular dysfunction (Nation et al 2019; Liu and Bu 2022). Importantly, these vascular pathologies are exacerbated when APOE4 is coexpressed with familial mutations in APP or components of the γ-secretase complex (Montagne and Zlokovic 2021), suggesting that the interactions between APOE4 and AD mutations can drive progression of the disease. However, most studies have been done in aging animals and few look at the impact of APOE4 expression in young animals and how that potentially contributes toward late-stage disease susceptibility. Here, we examined the potential functional interaction between APP mutations and ApoE4 in the progression of AD pathophysiology by comparing the hippocampal transcriptomes of 3-month-old female mice of 4 different genotypes: AppNL-G-F/NL-G-F , which harbours three knock-in mutations in the humanised Aβ region of APP (APP-TKI; Saito et al., 2014), mice with a single allele of human ApoE4 knocked-in, ApoE4+/wt (ApoE4), crosses of these two mouse lines, to create AppNL-G-F/NL-G-F;Apoe4+/wt (double-mutant or DM) mice, and wild-type (WT) mice that served as controls. RNAseq revealed nascent microglial activation signatures in both APP-TKI and double mutant datasets, as well as subtle but significant differences between APP-TKI and double mutant in expression of a subset of vascular remodeling genes.
2024-04-30 | GSE242751 | GEO
Project description:Apolipoprotein E (APOE) is a strong genetic risk factor for late-onset Alzheimer’s disease (AD) with APOE4 increasing and APOE2 decreasing risk relative to APOE3. In the P301S mouse model of tauopathy, ApoE4 increases tau pathology and neurodegeneration when compared to ApoE3 or the absence of ApoE. However, the role of ApoE isoforms in regulating lipid metabolism in the setting of tauopathy is unknown. Here, by using targeted lipidomics coupled with histological analysis, we demonstrate that in P301S tau mice, ApoE4 strongly promotes glial lipid accumulation along with significant perturbations in cholesterol metabolism and lysosomal function. Increasing lipid efflux in glia via administration of the LXR agonist GW3965 reduces lipid droplet accumulation in primary E4 microglia in vitro and GW3965 or Abca1 overexpression strongly attenuates tau pathology, neurodegeneration, and synapse loss in P301S/ApoE4 mice. By immunostaining, bulk and snRNA sequencing, we demonstrate reductions in reactive astrocytes and microglia as well as significant changes in cholesterol biosynthesis and metabolism in glia of tauopathy mice in response to LXR activation. These data suggest that promoting efflux of glial lipids via Abca1 could serve as a therapeutic approach to ameliorate tau and ApoE4-linked neurodegeneration.
2023-12-08 | GSE242693 | GEO
Project description:Apolipoprotein E (APOE) is a strong genetic risk factor for late-onset Alzheimer’s disease (AD) with APOE4 increasing and APOE2 decreasing risk relative to APOE3. In the P301S mouse model of tauopathy, ApoE4 increases tau pathology and neurodegeneration when compared to ApoE3 or the absence of ApoE. However, the role of ApoE isoforms in regulating lipid metabolism in the setting of tauopathy is unknown. Here, by using targeted lipidomics coupled with histological analysis, we demonstrate that in P301S tau mice, ApoE4 strongly promotes glial lipid accumulation along with significant perturbations in cholesterol metabolism and lysosomal function. Increasing lipid efflux in glia via administration of the LXR agonist GW3965 reduces lipid droplet accumulation in primary E4 microglia in vitro and GW3965 or Abca1 overexpression strongly attenuates tau pathology, neurodegeneration, and synapse loss in P301S/ApoE4 mice. By immunostaining, bulk and snRNA sequencing, we demonstrate reductions in reactive astrocytes and microglia as well as significant changes in cholesterol biosynthesis and metabolism in glia of tauopathy mice in response to LXR activation. These data suggest that promoting efflux of glial lipids via Abca1 could serve as a therapeutic approach to ameliorate tau and ApoE4-linked neurodegeneration.
2023-12-08 | GSE242180 | GEO