Bone morphogenetic protein increases tau phosphorylation and secretion in tauopathies in an APOE dependent manner
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE253647 | GEO | 2025/01/02
REPOSITORIES: GEO
Similar Datasets
Project description:Bone morphogenetic protein increases tau phosphorylation and secretion in tauopathies in an APOE dependent manner
| PRJNA1066402 | ENA
Project description:APOE is the strongest genetic risk factor for late-onset Alzheimer’s disease. ApoE exacerbates tau-associated neurodegeneration by driving microglial activation. However, how apoE regulates microglial activation and whether targeting apoE is therapeutically beneficial in tauopathy is unclear. Here we show that overexpressing a low-density lipoprotein receptor (LDLR) transgene in P301S tau transgenic mice markedly reduces brain apoE and ameliorates tau pathology and neurodegeneration. ApoE specifically interacts with a high-molecular-weight tau species, and highly correlates with phospho-tau and insoluble tau levels. Microglial expression of the LDLR transgene reduces intracellular apoE and is associated with less microglial activation. snRNA-seq analysis of apoE-deficient or LDLR-overexpressing brains reveals that apoE deficiency drives microglial catabolism and increases the oligodendrocyte progenitor cell population. LDLR overexpression shares overlapping mechanisms, but uniquely upregulates microglial expression of specific ion channels and neurotransmitter receptors in tauopathy. A subset of disease-associated astrocytes with both neuroprotective and neurotoxic gene signatures is also identified.
2021-02-06 | GSE166261 | GEO
Project description:To gain insight into the role of human APOE on tau-associated neurodegeneration, we examined P301S mutant tau transgenic mice carrying humanized APOE alleles
2024-03-07 | GSE226093 | GEO
Project description:Alzheimer’s disease (AD) is an age-associated neurodegenerative disease characterized by amyloidosis, tauopathy, and activation of microglia, the brain resident innate immune cells. We show that a RiboTag translational profiling approach can bypass biases due to cellular enrichment/cell sorting. In our recent study entitled “Microglial translational profiling reveals a convergent APOE pathway from aging, amyloid, and tau”, we utilized data acquired using this approach in models of amyloidosis, tauopathy, and aging, to reveal a common set of alterations and identified a central APOE-driven network that converged on CCL3 and CCL4 across all conditions. Notably, examination of the aged female dataset demonstrated a significant exacerbation of many of these shared transcripts in this APOE network, revealing a potential mechanism for increased AD susceptibility in females. This study has broad implications for microglial transcriptomic approaches and provides new insights into microglial pathways associated with different pathological aspects of aging and AD.
2018-07-25 | GSE117646 | GEO
Project description:Accumulation of tau is a critical event in several neurodegenerative disorders, collectively known as tauopathies, which include Alzheimer's disease and frontotemporal dementia. Pathological tau is hyperphosphorylated and aggregates to form neurofibrillary tangles. The molecular mechanisms leading to tau accumulation remain unclear and more needs to be done to elucidate them. Age is a major risk factor for all tauopathies, suggesting that molecular changes contributing to the aging process may facilitate tau accumulation and represent common mechanisms across different tauopathies. Here, we use multiple animal models and complementary genetic and pharmacological approaches to show that the mammalian target of rapamycin (mTOR) regulates tau phosphorylation and degradation. Specifically, we show that genetically increasing mTOR activity elevates endogenous mouse tau levels and phosphorylation. Complementary to it, we further demonstrate that pharmacologically reducing mTOR signaling with rapamycin ameliorates tau pathology and the associated behavioral deficits in a mouse model overexpressing mutant human tau. Mechanistically, we provide compelling evidence that the association between mTOR and tau is linked to GSK3β and autophagy function. In summary, we show that increasing mTOR signaling facilitates tau pathology, while reducing mTOR signaling ameliorates tau pathology. Given the overwhelming evidence that reducing mTOR signaling increases lifespan and healthspan, the data presented here have profound clinical implications for aging and tauopathies and provide the molecular basis for how aging may contribute to tau pathology. Additionally, these results provide preclinical data indicating that reducing mTOR signaling may be a valid therapeutic approach for tauopathies.
| S-EPMC3655115 | biostudies-literature
Project description:Mitochondria are dynamic organelles that influence cellular function through both cell-autonomous and non-cell autonomous mechanisms, such as production of paracrine and endocrine factors. Here, we demonstrate that mitochondrial regulation of the secretome is more extensive than previously appreciated, as both genetic and pharmacological disruption of the inner mitochondrial membrane caused upregulation of the Alzheimer’s disease risk factor apolipoprotein E (APOE) and other secretome components. This upregulation of secretory proteins was of a similar extent as modifications to the mitochondrial annotated proteome. Gene editing of SLC25A family inner mitochondrial membrane transporters, as well as genetic and pharmacological disruption of copper-dependent and independent steps of electron transport chain assembly and function, caused upregulation of APOE transcript, protein, and secretion, up to 16-fold. These APOE phenotypes were robustly expressed in diverse cell types and iPSC-derived human astrocytes as part of an inflammatory gene expression program. We propose that mitochondria act as novel upstream regulators of APOE-dependent cellular processes in health and disease. We report RNAseq profiles of human cell lines with CRISPR mediated mutagenesis of SLC25A1 and SLC5A4.
2022-12-01 | GSE201889 | GEO
Project description:Increased plasma homocysteinemia is considered a risk factor of dementia, including Alzheimer's disease (AD) and vascular dementia. However, the reason elevated plasma homocysteinemia increases the risk of dementia remains unknown. A pathological hallmark of AD is neurofibrillary tangles (NFTs) that consist of pathologically phosphorylated tau proteins. The effect of homocysteine (Hcy) on tau aggregation was explored using human neuroblastoma M1C cells that constitutively express human wild-type tau (4R0N) under the control of a tetracycline off system, primary mouse cultured neurons, and by inducing hyperhomocysteinemia in a mouse model of tauopathy (HHCy mice). A wide range of Hcy concentrations (10-1000 µM) increased total tau and phosphorylated tau protein levels. Hcy activated glycogen synthase kinase 3, and cyclin dependent kinase 5, major tau phosphokinases, and inactivated protein phosphatase 2A, a main tau phosphatase. Hcy exhibited cytotoxic effects associated with enhanced activation of caspase. Truncation of tau in the C-terminus, the cleavage site of caspase 3 (i.e., D421, detected by the TauC3 antibody) was also increased. Total tau, phosphorylated tau, as well as C-terminal cleaved tau were increased in the sarkosyl insoluble tau fraction. Hcy also increased the level of tau oligomers, as indicated by the tau oligomer complex 1 (TOC1) antibody that specifically identifies oligomeric tau species, in the tris insoluble, sarkosyl soluble fraction. The levels of TOC1-positive oligomeric tau were increased in brain lysates from HHCy mice, and treating HHCy mice with S-adenosylmethionine, an intermediate of Hcy, reduced the levels of oligomeric tau to control levels. These observations suggest that Hcy increases the levels of phosphorylated tau as well as truncated tau species via caspase 3 activation, and enhanced tau oligomerization and aggregation.
| S-EPMC5877752 | biostudies-literature
Project description:The most common genetic risk factor for late onset Alzheimer Disease (AD) is the APOE4 allele, with evidence for gain- and loss-of-function as a primary mechanism. ApoE knockout in mice abrogates AD phenotypes but causes severe atherosclerosis due to the role of liver ApoE in cholesterol homeostasis. Previous attempts to therapeutically block brain-specific ApoE in adult models of AD only modestly reduced ApoE expression and no significant impact on amyloid burden. Here, we optimized a divalent siRNA (di-siRNA) to selectively silence ApoE in brain (>2 months). By measuring transcriptomic changes upon knockdown of ApoE in the CNS in multiple mouse models of AD, we find that ApoE knockdown results in an upregulation of the innate immune response, likely through activation of microglia. Additionally, we find that the changes in the transcriptome were similar, but not identical, two weeks and two months post-treatment. We find that mild reduction of ApoE in the liver does not cause widespread transcriptomic changes, but near complete knockdown of ApoE in the liver results in the dysregulation of many lipid metabolism-related pathways.
2023-10-02 | GSE186756 | GEO
Project description:Tau protein abnormally aggregates in tauopathies, a diverse group of neurologic diseases that includes Alzheimer's disease (AD). In early stages of disease, tau becomes hyperphosphorylated and mislocalized, which can contribute to its aggregation and toxicity. We demonstrate that tau phosphorylation at Ser208 (pSer208) promotes microtubule dysfunction and tau aggregation in cultured cells. Comparative assessment of the epitopes recognized by antibodies AT8, CP13, and 7F2 demonstrates that CP13 and 7F2 are specific for tau phosphorylation at Ser202 and Thr205, respectively, independently of the phosphorylation state of adjacent phosphorylation sites. Supporting the involvement of pSer208 in tau pathology, a novel monoclonal antibody 3G12 specific for tau phosphorylation at Ser208 revealed strong reactivity of tau inclusions in the brains of PS19 and rTg4510 transgenic mouse models of tauopathy. 3G12 also labelled neurofibrillary tangles in brains of patients with AD but revealed differential staining compared to CP13 and 7F2 for other types of tau pathologies such as in neuropil threads and neuritic plaques in AD, tufted astrocytes in progressive supranuclear palsy and astrocytic plaques in corticobasal degeneration. These results support the hypothesis that tau phosphorylation at Ser208 strongly contributes to unique types of tau aggregation and may be a reliable marker for the presence of mature neurofibrillary tangles.
| S-EPMC7310041 | biostudies-literature
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