Similar Datasets
Project description:Reprogramming of adult somatic cells into induced pluripotent stem cells (iPSCs) resets the aging clock and is thought to erase other epigenomic marks. Here we show that iPSCs from late-onset sporadic Alzheimer’s disease (AD) cases retain epigenomic anomalies that supersede developmental defects, genomic instability, and neurodegeneration. When compared to iPSCs from elderly controls, AD iPSCs display reduced BMI1 and KDM5A expression, a more relax heterochromatin, and an altered DNA methylome. AD neuroepithelial cells show lesser efficient neural induction and forebrain specification, together with perturbed WNT signaling. They also present a unique genomic instability phenotype characterized by replication stress and DNA damage at the nuclear envelope-associated heterochromatin. BMI1 knockdown in control neuroepithelial cells phenocopied the AD-related pathologies. Long-term AD neuronal cultures show a dedifferentiation and loss-of-cell identity phenotype resembling epigenome erosion. BMI1 overexpression in AD neurons mitigates amyloid accumulation, tau pathology, heterochromatin fragmentation and G4 DNA induction. These findings implicate persistent epigenomic anomalies or uncharacterized genetic alterations working in trans on the epigenome in AD iPSCs, which could have broader implications in our understanding of the disease origin and pathophysiological mechanisms.
2024-07-30 | GSE255982 | GEO
Project description:Reprogramming of adult somatic cells into induced pluripotent stem cells (iPSCs) resets the aging clock and is thought to erase other epigenomic marks. Here we show that iPSCs from late-onset sporadic Alzheimer’s disease (AD) cases retain epigenomic anomalies that supersede developmental defects, genomic instability, and neurodegeneration. When compared to iPSCs from elderly controls, AD iPSCs display reduced BMI1 and KDM5A expression, a more relax heterochromatin, and an altered DNA methylome. AD neuroepithelial cells show lesser efficient neural induction and forebrain specification, together with perturbed WNT signaling. They also present a unique genomic instability phenotype characterized by replication stress and DNA damage at the nuclear envelope-associated heterochromatin. BMI1 knockdown in control neuroepithelial cells phenocopied the AD-related pathologies. Long-term AD neuronal cultures show a dedifferentiation and loss-of-cell identity phenotype resembling epigenome erosion. BMI1 overexpression in AD neurons mitigates amyloid accumulation, tau pathology, heterochromatin fragmentation and G4 DNA induction. These findings implicate persistent epigenomic anomalies or uncharacterized genetic alterations working in trans on the epigenome in AD iPSCs, which could have broader implications in our understanding of the disease origin and pathophysiological mechanisms.
2024-07-30 | GSE255981 | GEO
Project description:Reprogramming of adult somatic cells into induced pluripotent stem cells (iPSCs) resets the aging clock and is thought to erase other epigenomic marks. Here we show that iPSCs from late-onset sporadic Alzheimer’s disease (AD) cases retain epigenomic anomalies that supersede developmental defects, genomic instability, and neurodegeneration. When compared to iPSCs from elderly controls, AD iPSCs display reduced BMI1 and KDM5A expression, a more relax heterochromatin, and an altered DNA methylome. AD neuroepithelial cells show lesser efficient neural induction and forebrain specification, together with perturbed WNT signaling. They also present a unique genomic instability phenotype characterized by replication stress and DNA damage at the nuclear envelope-associated heterochromatin. BMI1 knockdown in control neuroepithelial cells phenocopied the AD-related pathologies. Long-term AD neuronal cultures show a dedifferentiation and loss-of-cell identity phenotype resembling epigenome erosion. BMI1 overexpression in AD neurons mitigates amyloid accumulation, tau pathology, heterochromatin fragmentation and G4 DNA induction. These findings implicate persistent epigenomic anomalies or uncharacterized genetic alterations working in trans on the epigenome in AD iPSCs, which could have broader implications in our understanding of the disease origin and pathophysiological mechanisms.
2024-07-30 | GSE255983 | GEO
Project description:Persistent epigenome anomalies in induced pluripotent stem cells from late-onset sporadic Alzheimer’s disease cases
| PRJNA1077342 | ENA
Project description:Persistent epigenome anomalies in induced pluripotent stem cells from late-onset sporadic Alzheimer’s disease cases [RNA-seq]
| PRJNA1077346 | ENA
Project description:Persistent epigenome anomalies in induced pluripotent stem cells from late-onset sporadic Alzheimer’s disease cases [BiSulfite-seq]
| PRJNA1077353 | ENA
Project description:Persistent epigenome anomalies in induced pluripotent stem cells from late-onset sporadic Alzheimer’s disease cases [scRNA-seq]
| PRJNA1077347 | ENA
Project description:Presenilin 1 (PSEN1) is the most frequently mutated gene in early-onset sporadic and familial Alzheimer’s disease (FAD). The PSEN1 complex displays gamma-secretase activity and promotes cleavage of the C99-terminal fragment of the Amyloid Precursor Protein (APP) into the A42 peptide. PSEN1 is also involved in vesicle transport across ER and mitochondria in so called mitochondria associated membranes. We generated induced pluripotent stem cells (iPSCs) from 5 controls and 5 FAD cases carrying the PSEN1 A246E and L286V mutations. Unexpectedly, global gene expression profile analysis of FAD iPSCs revealed profound perturbation of mitochondrial, Golgi apparatus and ER pathways. PSEN1, APP and Nicastrin were highly expressed in iPSCs and PSEN1 localized to membrane-bound organelles. FAD iPSCs grown slower and showed elevated cell death together with abnormally high A42 secretion. Mitochondrial reactive oxygen species (ROS) were elevated in FAD iPSCs and treatment with a ROS scavenger significantly improved cell death, proliferation, and DNA damage. However, it could not improve the severe ATP deficit. Inhibition of gamma-secretase activity further exacerbated the overall FAD iPSC phenotype. Cortical neurons produced from the differentiation of FAD iPSCs showed Alzheimer’s pathology and TGFb pathway hyper-activation. PSEN1-mutant iPSCs may serve as a new model to perform genome-wide genetic screens and to study FAD pathophysiology and PSEN1 cellular function.
2024-06-20 | GSE253337 | GEO
Project description:Alzheimer’s disease (AD) is the most common neurodegenerative dementia. Around 10% of cases present an age of onset before 65 years-old, which in turn can be divided in monogenic or familial AD (FAD) and sporadic early-onset AD (EOAD). Mutations in PSEN1, PSEN2 and APP genes have been linked with FAD. The aim of our study was to describe the brain whole-genome RNA expression profile of the posterior cingulate area in EOAD and FAD caused by PSEN1 mutations (FAD-PSEN1). 14 patients (7 EOAD and 7 FAD-PSEN1) and 7 neurologically healthy controls were selected and samples were hybridized in a Human Gene 1.1 microarray from Affymetrix. When comparing controls with EOAD and controls with FAD-PSEN1, we found 3183 and 3351 differentially expressed genes (DEG) respectively (FDR corrected p<0.05). However, any DEG was found in the comparison of the two groups of patients. Microarrays were validated through quantitative-PCR of 17 DEG. In silico analysis of the DEG revealed an alteration in biological pathways related to calcium-signaling, axon guidance and long-term potentiation (LTP), among others, in both groups of patients. These pathways are mainly related with cell signalling cascades, synaptic plasticity and learning and memory processes. In conclusion, the altered biological final pathways in EOAD and FAD-PSEN1 are highly coincident. Also, the findings are in line with those previously reported for late-onset AD (LOAD, onset >65 years-old), which implies that the consequences of the disease at the molecular level are similar in the final stages of the disease. 21 Samples were analyzed: 7 controls, 7 Early-onset Alzheimer's disease (AD) patients and 7 early-onset AD genetically determined by a mutation in PSEN1 gene.
2015-01-20 | E-GEOD-39420 | biostudies-arrayexpress
Project description:Non-familial Alzheimer’s disease (AD) occurring before 65 years of age is commonly referred to as early-onset Alzheimer’s disease (EOAD) and constitutes ~5-6% of all Alzheimer’s disease (AD) cases. While EOAD exhibits the same clinicopathological changes such as amyloid plaques, neurofibrillary tangles (NFTs), brain atrophy, and cognitive decline as observed in the more prevalent late-onset AD (LOAD), EOAD patients tend to have more severe cognitive deficits, including visuospatial, language, and motor dysfunction. Patient-derived induced pluripotent stem cells (iPSCs) have been used to model and study penetrative, familial AD (FAD) mutations in APP, PSEN1, and PSEN2, but have been seldom used for sporadic forms of AD that display more heterogeneous disease manifestation. In this study, we sought to characterize iPSC-derived neurons from EOAD patients via RNA-sequencing. A modest difference in expression profiles between EOAD patients and non-demented control subjects resulted in a limited number of differentially expressed genes (DEGs). Based on this analysis, we provide evidence that iPSC-derived neuron model systems, likely due to the loss of EOAD-associated epigenetic signatures during the iPSC reprogramming, are not an ideal model system to study sporadic AD.
2023-11-21 | GSE231341 | GEO