Project description:This SuperSeries is composed of the following subset Series: GSE41751: Correlated alterations in genome organization, histone methylation, and DNA-lamina interactions in Hutchinson-Gilford progeria syndrome (expression) GSE41757: Correlated alterations in genome organization, histone methylation, and DNA-lamina interactions in Hutchinson-Gilford progeria syndrome (ChIP-seq) GSE41763: Correlated alterations in genome organization, histone methylation, and DNA-lamina interactions in Hutchinson-Gilford progeria syndrome (Hi-C) Refer to individual Series
Project description:DNA methylation is a key epigenetic modification regulating genome organization, stability, and gene expression. Stable DNA methylation critically relies on methyl groups provided through folate-mediated one-carbon (C1) metabolism, yet the origin and regulation of C1 supply remain elusive. Here we demonstrate that photorespiration serves as a major C1 source for DNA methylation in Arabidopsis. We show that C1 from formate, a photorespiratory byproduct, is incorporated into 5-methyl-cytosine via the reductive cytosolic folate pathway. This occurs predominantly during the day, negatively regulating serine utilization as alternative C1 source. Consequently, suppression of photorespiration under elevated CO₂ levels alters the DNA methylation landscape, an effect exacerbated when regulation of C1 metabolism by the formate-dependent pathway is impaired. Thus, our findings link the fundamental metabolic process of photorespiration to epigenetic stability, highlighting how rising atmospheric CO₂ levels can induce DNA methylation changes.
Project description:Kabuki syndrome is a monogenic disorder caused by loss of function variants in either of two genes encoding histone-modifying enzymes. We performed targeted sequencing in a cohort of 27 probands with a clinical diagnosis of Kabuki syndrome. Of these, 12 had causative variants in the two known Kabuki syndrome genes. In 2, we identified presumptive loss of function de novo variants in KMT2A (missense and splice site variants), a gene that encodes another histone modifying enzyme previously exclusively associated with Wiedermann-Steiner syndrome. Although Kabuki syndrome is a disorder of histone modification, we also find alterations in DNA methylation among individuals with a Kabuki syndrome diagnosis relative to matched normal controls, regardless of whether they carry a variant in KMT2A or KMT2D or not. Furthermore, we observed characteristic global abnormalities of DNA methylation that distinguished patients with a loss of function variant in KMT2D or missense or splice site variants in either KMT2D or KMT2A from normal controls. Our results provide new insights into the relationship of genotype to epigenotype and phenotype and indicate cross-talk between histone and DNA methylation machineries exposed by inborn errors of the epigenetic apparatus.
Project description:Genome-wide analysis of DNA methylation profiles from patients with Sjögren's syndrome with high versus low fatigue levels using the Illumina Infinium HumanMethylation450 Beadchip array. Background Chronic fatigue is a common, disabling, and poorly understood phenomenon. Recent studies indicate that epigenetic mechanisms may be involved in the expression of fatigue, a prominent feature of primary Sjögren’s syndrome (pSS). The aim of this study was to investigate whether DNA methylation profiles of whole blood are associated with fatigue in patients with pSS. Methods 48 pSS patients with high (n=24) or low (n=24) fatigue as measured by a visual analogue scale were included. Genome-wide DNA methylation was investigated using the Illumina HumanMethylation450 BeadChip array.