Brain 5-hydroxymethylcytosine alterations are associated with Alzheimer’s disease neuropathology
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE291402 | GEO | 2025/03/07
REPOSITORIES: GEO
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Project description:Alzheimer’s disease (AD) is a chronic neurodegenerative disorder that is characterized by progressive neuropathology and cognitive decline. We performed a cross-tissue analysis of methylomic variation in AD using samples from three independent human post-mortem brain cohorts. We identified a differentially methylated region in the ankyrin 1 (ANK1) gene that was associated with neuropathology in the entorhinal cortex, a primary site of AD manifestation. This region was confirmed as being substantially hypermethylated in two other cortical regions (superior temporal gyrus and prefrontal cortex), but not in the cerebellum, a region largely protected from neurodegeneration in AD, or whole blood obtained pre-mortem from the same individuals. Neuropathology-associated ANK1 hypermethylation was subsequently confirmed in cortical samples from three independent brain cohorts. This study represents, to the best of our knowledge, the first epigenome-wide association study of AD employing a sequential replication design across multiple tissues and highlights the power of this approach for identifying methylomic variation associated with complex disease. For the first (discovery) stage of our analysis, we used multiple tissues from donors (N = 122) archived in the MRC London Brainbank for Neurodegenerative Disease. From each donor, we isolated genomic DNA from four brain regions (EC, superior temporal gyrus (STG), prefrontal cortex (PFC) and CER) and, where available, from whole blood obtained pre-mortem. Our analyses focused on identifying differentially methylated positions (DMPs) associated with Braak staging, a standardized measure of neurofibrillary tangle burden determined at autopsy.
2014-08-17 | E-GEOD-59685 | biostudies-arrayexpress
Project description:5-hydroxymethylcytosine (5hmC), converted from 5-methylcytosine (5mC) by Tet enzymes, has recently drawn attention as the ‘sixth base’ of DNA since it is considered to be an intermediate of the demethylation pathway. Nonetheless, it remains to be addressed how 5hmC is linked to the development of human imprinting disorders. In this regard, conventional bisulfite (BS) treatment is unable to differentiate 5hmC from 5mC. It is thus hypothesized that BS conversion-derived ‘hypermethylation’ at imprinting control regions (ICRs), which may cause human imprinting disorders, would in fact be attributable to excessively increased levels of 5hmC as well as 5mC. To test this hypothesis, we applied the newly developed oxidative BS (oxBS) treatment to detect 5hmC in blood samples from Kagami-Ogata syndrome (KOS14) patients caused by perturbed expression of clustered imprinted genes on 14q32.2 resulting from the hypermethylation of ICRs at this locus, IG-DMR and MEG3-DMR. oxBS with pyrosequencing and cloning-based sequencing revealed that there were few amounts of 5hmC at the hypermethylated IG-DMR in blood samples from KOS14 patients. oxBS with genome-wide methylation array analysis demonstrated that global levels of 5hmC were very low with similar distribution patterns in blood samples from KOS14 patients and normal controls. We also confirmed the presence of a large amount of 5hmC in the brain sample from a normal control. 5hmC is not a major component in abnormally hypermethylated ICRs or at a global level, at least in blood from KOS14 patients. As the brain sample contained a large amount of 5hmC, the neural tissues of KOS14 patients are promising candidates for analysis in elucidating the role of 5hmC in the neurodevelopmental context. We generated illumina 450k DNA methylation data for BS or oxBS converted samples of three KOS14 blood samples, one control pooled blood sample and one control brain sample with two technical replicates for each sample.
2015-09-01 | E-GEOD-71328 | biostudies-arrayexpress
Project description:Background Alzheimer’s disease is a progressive neurodegenerative disorder that is hypothesized to involve epigenetic dysfunction. Previous studies of DNA modifications in Alzheimer’s disease have been unable to distinguish between DNA methylation and DNA hydroxymethylation. DNA hydroxymethylation has been shown to be enriched in the human brain, although its role in Alzheimer’s disease has not yet been fully explored. Here we utilize oxidative bisulfite conversion, in conjunction with the Illumina Infinium Human Methylation 450K microarray, to identify neuropathology-associated differential DNA methylation and DNA hydroxymethylation in the entorhinal cortex. Results We identified one experiment-wide significant differentially methylated position residing in the WNT5B gene. Next, we investigated pathology-associated regions consisting of multiple adjacent loci. We identified one significant differentially hydroxymethylated region consisting of four probes spanning 104 bases in the FBXL16 gene. We also identified two significant differentially methylated regions: one consisting of two probes in a 93 base-pair region in the ANK1 gene and the other consisting of six probes in a 99 base-pair region in the ARID5B gene. We also highlighted three regions that show alterations in unmodified cytosine: two probes in a 39 base-pair region of ALLC, two probes in a 69 base-pair region in JAG2, in addition to the same six probes in ARID5B that were differentially methylated. Finally we replicated significant ANK1 disease-associated hypermethylation and hypohydroxymethylation patterns across eight CpG sites in an extended 118 base-pair region in an independent cohort using oxidative-bisulfite pyrosequencing. Conclusions Our study represents the first epigenome-wide association study of both DNA methylation and hydroxymethylation in Alzheimer’s disease entorhinal cortex. We demonstrate that previous estimates of DNA hypermethylation in ANK1 in Alzheimer’s disease were underestimates as it is confounded by hypohydroxymethylation.
2019-03-05 | GSE105109 | GEO
Project description:Alzheimer’s disease (AD) is a chronic neurodegenerative disorder that is characterized by progressive neuropathology and cognitive decline. We performed a cross-tissue analysis of methylomic variation in AD using samples from three independent human post-mortem brain cohorts. We identified a differentially methylated region in the ankyrin 1 (ANK1) gene that was associated with neuropathology in the entorhinal cortex, a primary site of AD manifestation. This region was confirmed as being substantially hypermethylated in two other cortical regions (superior temporal gyrus and prefrontal cortex), but not in the cerebellum, a region largely protected from neurodegeneration in AD, or whole blood obtained pre-mortem from the same individuals. Neuropathology-associated ANK1 hypermethylation was subsequently confirmed in cortical samples from three independent brain cohorts. This study represents, to the best of our knowledge, the first epigenome-wide association study of AD employing a sequential replication design across multiple tissues and highlights the power of this approach for identifying methylomic variation associated with complex disease.
2014-08-17 | GSE59685 | GEO
Project description:The study of 5-hydroxylmethylcytosines (5hmC), the sixth base of the mammalian genome, as an epigenetic mark has been hampered by a lack of method to map it at single-base resolution. Previous affinity purification-based methods could not precisely locate 5hmC nor accurately determine its relative abundance at each modified site. We here present a genome-wide approach for mapping 5hmC at base resolution. Application of this new method to the embryonic stem cells not only confirms widespread distribution of 5hmC in mammalian genome, but also reveals a strong sequence bias and strand asymmetry at sites of 5hmC. Additionally, the relative abundance of 5hmC varies significantly depending on the types of functional sequences, suggesting different mechanisms for 5hmC deposition and maintenance. Furthermore, we observe high levels of 5hmC and reciprocally low levels of 5mC at transcription factor binding sites, revealing a dynamic DNA methylation process at cis-regulatory elements.
2012-05-17 | GSE36173 | GEO
Project description:To assess their utility in routine neuropathology, we prospectively integrated DNA methylation-based CNS tumor classification and targeted gene panel sequencing of tumor and constitutional DNA with blinded neuropathological reference diagnostics for a population-based cohort of > 1,200 newly-diagnosed pediatric patients.
2023-01-30 | GSE215240 | GEO
Project description:5-hydroxymethylcytosine (5hmC), converted from 5-methylcytosine (5mC) by Tet enzymes, has recently drawn attention as the ‘sixth base’ of DNA since it is considered to be an intermediate of the demethylation pathway. Nonetheless, it remains to be addressed how 5hmC is linked to the development of human imprinting disorders. In this regard, conventional bisulfite (BS) treatment is unable to differentiate 5hmC from 5mC. It is thus hypothesized that BS conversion-derived ‘hypermethylation’ at imprinting control regions (ICRs), which may cause human imprinting disorders, would in fact be attributable to excessively increased levels of 5hmC as well as 5mC. To test this hypothesis, we applied the newly developed oxidative BS (oxBS) treatment to detect 5hmC in blood samples from Kagami-Ogata syndrome (KOS14) patients caused by perturbed expression of clustered imprinted genes on 14q32.2 resulting from the hypermethylation of ICRs at this locus, IG-DMR and MEG3-DMR. oxBS with pyrosequencing and cloning-based sequencing revealed that there were few amounts of 5hmC at the hypermethylated IG-DMR in blood samples from KOS14 patients. oxBS with genome-wide methylation array analysis demonstrated that global levels of 5hmC were very low with similar distribution patterns in blood samples from KOS14 patients and normal controls. We also confirmed the presence of a large amount of 5hmC in the brain sample from a normal control. 5hmC is not a major component in abnormally hypermethylated ICRs or at a global level, at least in blood from KOS14 patients. As the brain sample contained a large amount of 5hmC, the neural tissues of KOS14 patients are promising candidates for analysis in elucidating the role of 5hmC in the neurodevelopmental context.
2015-09-01 | GSE71328 | GEO
Project description:The study of 5-hydroxylmethylcytosines (5hmC), the sixth base of the mammalian genome, as an epigenetic mark has been hampered by a lack of method to map it at single-base resolution. Previous affinity purification-based methods could not precisely locate 5hmC nor accurately determine its relative abundance at each modified site. We here present a genome-wide approach for mapping 5hmC at base resolution. Application of this new method to the embryonic stem cells not only confirms widespread distribution of 5hmC in mammalian genome, but also reveals a strong sequence bias and strand asymmetry at sites of 5hmC. Additionally, the relative abundance of 5hmC varies significantly depending on the types of functional sequences, suggesting different mechanisms for 5hmC deposition and maintenance. Furthermore, we observe high levels of 5hmC and reciprocally low levels of 5mC at transcription factor binding sites, revealing a dynamic DNA methylation process at cis-regulatory elements. Base resolution sequencing of 5 hydroxymethylcytosine in human and mouse embryonic stem cells
2012-05-16 | E-GEOD-36173 | biostudies-arrayexpress
Project description:Alzheimer's disease is a progressive neurodegenerative disorder that is hypothesized to involve epigenetic dysfunction. We undertook an epigenome-wide association study across three independent brain tissue cohorts (total n = 999) to identify differential DNA methylation associated with neuropathology in the superior temporal gyrus and prefrontal cortex. We present robust evidence for elevated DNA methylation associated with AD neuropathology across an extended region spanning the HOXA gene cluster on chromosome 7. Prefrontal cortex and superior temporal gyrus tissue from 147 individuals with varying levels of AD pathology. DNA modifications for these samples were quantified using the Illumina Infinium Human 450K Methylation Array.
2016-08-01 | E-GEOD-80970 | biostudies-arrayexpress
Project description:Traumatic brain injury (TBI) can lead to significant neuropsychiatric problems and neurodegenerative pathologies, which develop and persist years after injury. Neuroinflammatory processes evolve over this same period. Therefore, we aimed to determine the contribution of microglia to neuropathology at acute (1-day post-injury; dpi), subacute (7 dpi), and chronic (30 dpi) time-points. Microglia were depleted with PLX5622, a CSF1R antagonist, prior to midline fluid percussion injury in male mice and cortical neuropathology/inflammation was assessed using a neuropathology mRNA panel. NanoString Neuropathology gene expression panel was used to quantify expression from RNA microdissected from the mouse cortex.
2020-11-15 | GSE160651 | GEO