Search results for "METHYLATION"
showing 10 items of 607 documents
Residential greenness-related DNA methylation changes
2021
Abstract Background Residential greenness has been associated with health benefits, but its biological mechanism is largely unknown. Investigation of greenness-related DNA methylation profiles can contribute to mechanistic understanding of the health benefits of residential greenness. Objective To identify DNA methylation profiles associated with greenness in the immediate surroundings of the residence. Methods We analyzed genome-wide DNA methylation in 1938 blood samples (982 participants) from the Swiss Cohort Study on Air Pollution and Lung and Heart Diseases in Adults (SAPALDIA). We estimated residential greenness based on normalized difference vegetation index at 30 × 30 m cell (green3…
Maintenance of glutathione levels and its importance in epigenetic regulation.
2014
Glutathione (GSH) is present in almost all cell types playing an important function in organisms. It is the main antioxidant in many cell types and it also regulates the function of proteins, including transcription factors (reviewed in Pallardo et al., 2009; Markovic et al., 2010; Garcia-Gimenez et al., 2013a). Over recent years, growing evidence has suggested a link between GSH metabolism and the control of epigenetic mechanisms. Epigenetics is defined as the mitotically/meiotically heritable changes in gene expression that are not due to changes in the primary DNA sequence. This link between GSH and epigenetics occurs at different levels. Hence, GSH can affect DNA and histone methylation…
Gastric histamine methyltransferase: Different methylation rates for enantiomers of side-chain methylated histamine analogues using a highly purified…
1984
The inhibitor/activator and substrate properties of enantiomers of two methylated histamines (MH) were investigated using a histamine methyltransferase preparation which was purified 1207-fold from pig fundic mucosa by ultracentrifugation, ion-exchange chromatography on DEAE-cellulose and preparative electrofocusing. In 1-100 microM concentrations, S-alpha-MH and R-alpha-MH were acceptor substrates as good as histamine itself. When substrate concentrations were increased to 1 mM these substances were methylated to an even greater extent than histamine, since they did not exert substrate inhibition on HMT. Introduction of a further methyl-group into the N alpha-position reduced acceptor subs…
DNA methylation changes associated with prenatal mercury exposure:A meta-analysis of prospective cohort studies from PACE consortium
2022
Mercury (Hg) is a ubiquitous heavy metal that originates from both natural and anthropogenic sources and is transformed in the environment to its most toxicant form, methylmercury (MeHg). Recent studies suggest that MeHg exposure can alter epigenetic modifications during embryogenesis. In this study, we examined associations between prenatal MeHg exposure and levels of cord blood DNA methylation (DNAm) by meta-analysis in up to seven independent studies (n = 1462) as well as persistence of those relationships in blood from 7 to 8 year-old children (n = 794). In cord blood, we found limited evidence of differential DNAm at cg24184221 in MED31 (β = 2.28 × 10-4, p-value = 5.87 × 10-5) in relat…
Release of Hypoacetylated and Trimethylated Histone H4 Is an Epigenetic Marker of Early Apoptosis
2006
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Urinary Arsenic Species and Methylation Efficiency During Pregnancy: Concentrations and Associated Factors in Spanish Pregnant Women
2021
Background: Arsenic (As) is considered to be toxic for humans, the main routes of exposure being through drinking water and the diet. Once ingested, inorganic arsenic can be methylated sequentially to monomethyl and dimethyl arsenicals. Several factors can affect both As exposure and methylation efficiency. Objectives: To describe the urinary concentrations of the different As species and evaluate the methylation effi-ciency during pregnancy, as well as their associated factors in a birth cohort of pregnant Spanish women. Methods: Participants in this cross-sectional study were 1017 pregnant women from two areas of Spain who had taken part in the INMA (Environment and Childhood) project (20…
Genome-wide parent-of-origin DNA methylation analysis reveals the intricacies of human imprinting and suggests a germline methylation-independent mec…
2014
Genomic imprinting is a form of epigenetic regulation that results in the expression of either the maternally or paternally inherited allele of a subset of genes (Ramowitz and Bartolomei 2011). This imprinted expression of transcripts is crucial for normal mammalian development. In humans, loss-of-imprinting of specific loci results in a number of diseases exemplified by the reciprocal growth phenotypes of the Beckwith-Wiedemann and Silver-Russell syndromes, and the behavioral disorders Angelman and Prader-Willi syndromes (Kagami et al. 2008; Buiting 2010; Choufani et al. 2010; Eggermann 2010; Kelsey 2010; Mackay and Temple 2010). In addition, aberrant imprinting also contributes to multige…
Polycomb-like 2 Associates with PRC2 and Regulates Transcriptional Networks during Mouse Embryonic Stem Cell Self-Renewal and Differentiation
2010
SummaryPolycomb group (PcG) proteins are conserved epigenetic transcriptional repressors that control numerous developmental gene expression programs and have recently been implicated in modulating embryonic stem cell (ESC) fate. We identified the PcG protein PCL2 (polycomb-like 2) in a genome-wide screen for regulators of self-renewal and pluripotency and predicted that it would play an important role in mouse ESC-fate determination. Using multiple biochemical strategies, we provide evidence that PCL2 is a Polycomb Repressive Complex 2 (PRC2)-associated protein in mouse ESCs. Knockdown of Pcl2 in ESCs resulted in heightened self-renewal characteristics, defects in differentiation, and alte…
Mouse embryonic stem cells are hypersensitive to apoptosis triggered by the DNA damage O(6)-methylguanine due to high E2F1 regulated mismatch repair.
2007
Exposure of stem cells to genotoxins may lead to embryonic lethality or teratogenic effects. This can be prevented by efficient DNA repair or by eliminating genetically damaged cells. Using undifferentiated mouse embryonic stem (ES) cells as a pluripotent model system, we compared ES cells with differentiated cells, with regard to apoptosis induction by alkylating agents forming the highly mutagenic and killing DNA adduct O(6)-methylguanine. Upon treatment with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), ES cells undergo apoptosis at much higher frequency than differentiated cells, although they express a high level of the repair protein O(6)-methylguanine-DNA methyltransferase (MGMT). Apo…
Poly-ADP-Ribose (PAR) as an epigenetic flag
2009
Epigenetics is the study of hereditable chromatin modifications, such as DNA methylation, histone modifications, and nucleosome-remodelling, which occur without alterations to the DNA sequence. The establishment of different epigenetic states in eukaryotes depends on regulatory mechanisms that induce structural changes in chromatin in response to environmental and cellular cues. Two classes of enzymes modulate chromatin accessibility: chromatin-covalent modifiers and ATP-dependent chromatin remodelling complexes. The first class of enzymes catalyzes covalent modifications of DNA as well as the amino- and carboxy-terminal tails of histones, while the second uses the energy of ATP hydrolysis …