Aging-Related Decline of Astrocytic APOE Expression via Extracellular Vesicle
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE297123 | GEO | 2025/05/19
REPOSITORIES: GEO
Similar Datasets
Project description:Astrocyte dysfunction impacts their normal function, including neuronal support, thereby contributing to neurodegenerative pathologies including Alzheimer's disease (AD). Therefore to understand the role of astrocytes in the pathogenesis of age-related disorders we analysed the gene expression profile of astrocytes with respect to Alzheimer-type pathology. The aim of the present study was to combine immuno-LCM and microarray analysis to characterise the astrocyte transcriptome at different Braak stages, and with respect to ApoE genotype, in post-mortem human temporal cortex sampled dervied from the Medical Research Council Cognitive Function and Ageing Study (MRC-CFAS). GFAP-positive astrocytes were isolated from age, sex and brain pH-matched cases derived from the MRC-CFAS cohort, using immuno laser capture microdissection. The extracted RNA was amplified and applied to HGU133 Plus 2.0 Affymetrix gene arrays. Genes were considered differentially expressed if they showed a minimum 1.5 fold change at p<0.02 in all 6 individual cases in each stage of pathology [18 cases in total: 6 cases Braak stages I-II (3 cases carried at least one ApoE epsilon4 allele and 3 were ApoEe4 negative); 6 cases Braak stages III-IV (3 ApoEe4 positive and 3 ApoEe4 negative; 6 cases Braak stages V-VI (3 ApoEe4 positive and 3 ApoEe4 negative)]. keywords: human GFAP-positive astrocytes
2011-06-01 | E-GEOD-29652 | biostudies-arrayexpress
Project description:Aging-Related Decline of Astrocytic APOE Expression via Extracellular Vesicle
| PRJNA1262823 | ENA
Project description:Astrocyte dysfunction impacts their normal function, including neuronal support, thereby contributing to neurodegenerative pathologies including Alzheimer's disease (AD). Therefore to understand the role of astrocytes in the pathogenesis of age-related disorders we analysed the gene expression profile of astrocytes with respect to Alzheimer-type pathology. The aim of the present study was to combine immuno-LCM and microarray analysis to characterise the astrocyte transcriptome at different Braak stages, and with respect to ApoE genotype, in post-mortem human temporal cortex sampled dervied from the Medical Research Council Cognitive Function and Ageing Study (MRC-CFAS).
2011-06-01 | GSE29652 | GEO
Project description:The major genetic risk factor for Alzheimer’s disease (AD), APOE4, accelerates beta-amyloid (Aβ) plaque formation, but whether this is caused by APOE expressed in microglia or astrocytes is debated. We express here the human APOE isoforms in astrocytes in an Apoe-deficient AD mouse model. This is not only sufficient to restore the amyloid plaque pathology but also induces the characteristic transcriptional pathological responses in Apoe-deficient microglia surrounding the plaques. We find that both APOE4 and the protective APOE2 from astrocytes increase fibrillar plaque deposition, but differentially affect soluble Aβ aggregates. Microglia and astrocytes show specific alterations in function of APOE genotype expressed in astrocytes. Our experiments indicate a central role of the astrocytes in APOE mediated amyloid plaque pathology and in the induction of associated microglia responses.
2024-10-04 | GSE252454 | GEO
Project description:SORL1 is implicated in the pathogenesis of Alzheimer’s disease (AD) through genetic studies. To interrogate the role(s) of SORL1 in human brain cells, SORL1 null iPSCs are differentiated to neuron, astrocyte, microglial, and endothelial cell fates. Loss of SORL1 leads to alterations in both overlapping and distinct pathways across cell types, with the greatest effects in neurons and astrocytes. SORL1 loss induces a neuron-specific reduction in APOE and CLU and altered lipid profiles. Enhancement of retromer-mediated trafficking rescues tau phenotypes observed in SORL1 null neurons but does not rescue APOE levels. Pathway analyses implicate TGF-β/SMAD signaling in SORL1 function, and modulating SMAD signaling in neurons alters APOE RNA levels in a SORL1-dependent manner. Analyses of iPSCs derived from a large cohort reveal a neuron-specific association between SORL1, APOE, and CLU levels, a finding validated in post-mortem brain. These studies provide a mechanistic link between strong genetic risk factors for AD.
2023-10-24 | PXD044093 | Pride
Project description:Glaucoma is an optic neuropathy characterized by progressive degeneration of retinal ganglion cells (RGCs) and visual loss. Previous studies have reported that the variation of the ATP-binding cassette transporter 1 (ABCA1) gene is linked to a higher risk of glaucoma in humans, but the pathological mechanisms remain unknown. Here we report that ABCA1 loss, especially in astrocytes, causes optic neuropathy. ABCA1 was mainly expressed in astrocytes rather than neurons, and that knockout of Abca1 gene under GFAP promoter (Glia-KO) caused age-associated RGC degeneration and ocular dysfunction without affecting intraocular pressure, a major risk factor for glaucoma. Glia-KO mice showed age-associated changes in astrocyte reactivity accompanied by the accumulation of cholesterol, a major substrate of ABCA1. Single-cell RNA sequencing revealed that Abca1 deficiency causes astrocyte-triggered inflammation and increased sensitivity of RGCs against excitotoxicity. Altogether, these findings suggest that astrocytic dysfunction caused by ABCA1 loss triggers age-associated optic neuropathy-like pathology.
2022-07-11 | GSE207929 | GEO
Project description:Glaucoma is an optic neuropathy characterized by progressive degeneration of retinal ganglion cells (RGCs) and visual loss. Previous studies have reported that the variation of the ATP-binding cassette transporter 1 (ABCA1) gene is linked to a higher risk of glaucoma in humans, but the pathological mechanisms remain unknown. Here we report that ABCA1 loss, especially in astrocytes, causes optic neuropathy. ABCA1 was mainly expressed in astrocytes rather than neurons, and that knockout of Abca1 gene under GFAP promoter (Glia-KO) caused age-associated RGC degeneration and ocular dysfunction without affecting intraocular pressure, a major risk factor for glaucoma. Glia-KO mice showed age-associated changes in astrocyte reactivity accompanied by the accumulation of cholesterol, a major substrate of ABCA1. Single-cell RNA sequencing revealed that Abca1 deficiency causes astrocyte-triggered inflammation and increased sensitivity of RGCs against excitotoxicity. Altogether, these findings suggest that astrocytic dysfunction caused by ABCA1 loss triggers age-associated optic neuropathy-like pathology.
2022-07-11 | GSE207928 | GEO
Project description:Normal brain aging is marked by a cognitive decline, spurred by changes in cellular metabolism and homeostatic dysregulation, as well as modifications in synapses and neuronal connectivity. Astrocytes are well positioned as an effector of these changes, although how properties of astrocytes change with age remains unclear. Here, we address this question by profiling astrocytic gene expression from multiple brain regions of adult (4 month-old) and aged (2 years-old) mice. We isolated mRNA from transgenic mice where ribosomes within astrocytes were genetically tagged (GFAP-cre x RPL22-HA, astrocyte ribotag). We then used RNA sequencing to identify and quantify the astrocyte-enriched mRNA, analyzing 4 different brain regions: visual cortex, somatomotor cortex, hypothalamus, and cerebellum. Overall, we find that astrocyte expression of inflammatory and immune response factors increase with age, as well as changes in genes associated with metabolism, cholesterol synthesis, and synaptogenesis. Going forward, these data contribute to an understanding of astrocyte diversity and provide insight into the role of astrocytes in normal aging.
2017-12-11 | GSE99791 | GEO
Project description:Astrocytes are key cells in brain aging, helping neurons to undertake healthy aging or otherwise letting them enter into a spiral of neurodegeneration. We aimed to characterize astrocytes cultured from senescence-accelerated prone 8 (SAMP8) mice, a mouse model of brain pathological aging, along with the effects of caloric restriction, the most effective rejuvenating treatment known so far. Analysis of the transcriptomic profiles of SAMP8 astrocytes cultured in control conditions and treated with caloric restriction serum was performed using mRNA microarrays. A decrease in mitochondrial and ribosome mRNA, which was restored by caloric restriction, confirmed the age-related profile of SAMP8 astrocytes and the benefits of caloric restriction. An amelioration of antioxidant and neurodegeneration-related path- ways confirmed the brain benefits of caloric restriction. Studies of oxidative stress and mitochondrial function demonstrated a reduction of oxidative damage and partial improvement of mito- chondria after caloric restriction. In summary, caloric restriction showed a significant tendency to normalize pathologically aged astrocytes through the activation of pathways that are protective against the age-related deterioration of brain physiology. Key words: astrocytes; caloric restriction; mitochondria; oxidative stress; RNA microarrays; SAMP8. Primary cultures enriched in astrocytes were obtained from cerebral cortical tissue from 2-day-old SAMP8 and SAMR1 mice. Astrocyte cultures were established and experiments were routinely carried out after 21 days in culture. Established astrocyte cultures of both SAMR1 and SAMP8 consisted of 85-90% astrocytes, 10-15% microglia and 0.1-1% oligodendroglia. Sera from rats subjected to ad libitum (AL) diet and to CR were obtained as described for the establishment of the CR in vitro model (de Cabo et al., 2003). Serum was heat inactivated at 56°C prior to use in astrocyte culture experiments. Treatment in vitro was performed by adding 10% volume CR or AL serum onto the astrocyte culture medium for 48 h, the cells were harvested and RNA was extracted for the microarray studies. Three biological replicates for each condition were done and RNA was extracted for the microarray studies. Please note that SAM models were developed from AKR/J by Kyoto University. Five litters with severe senescence were selected to further propagate and examine these characteristics. Litters that showed normal aging were selected as a senescence-resistant series (R-series). The genetic background of the SAM mice became suspect after the pathological findings were different from the AKR/J mouse. Each SAM model is genetically different. Each SAM colony was acquired by Harlan by Takeda Chemical Ltd. in 2002. And here is the link to the company site. http://www.harlan.com/products_and_services/research_models_and_services/research_models/sam_inbred_mice/samp8tahsd.hl
2015-06-23 | E-GEOD-60388 | biostudies-arrayexpress
Project description:The apolipoprotein E (APOE) gene is the strongest genetic risk factor for Alzheimer disease (AD). In addition to effects of apoE on amyloid-β, results have shown that apoE markedly influences pathological forms of tau and tau-mediated neurodegeneration with apoE4 having a strong deleterious effect on both parameters. In the brain, apoE is produced and secreted primarily from astrocytes and also by activated microglia though the cell-specific role of each form of apoE in the setting of neurodegeneration has not been determined. We utilized a well- characterized mouse model of tauopathy, P301S Tau transgenic mice expressing floxed APOE-e4 or APOE-e3 alleles. We crossed these mice with Aldh1l1-CreERT2 mice and at 5.5 months of age, after the onset of tau pathology, administered tamoxifen or vehicle. We then compared mice with or without inducible knockout of astrocyte APOE at 9.5 months of age. Single nucleus RNA sequencing analysis revealed striking gene expression changes in all cell types in P301S mice with astrocytic APOE4 playing a role in modulating neuron, astrocyte, and microglial gene expression to a more homeostatic state.
2021-04-13 | GSE164507 | GEO