title: Extensive demethylation of normally hypermethylated CpG islands occurs in human atherosclerotic arteries.
abstract: Global DNA hypomethylation potentially leading to pro-atherogenic gene expression occurs in atherosclerotic lesions. However, limited information is available on the genomic location of hypomethylated sequences. We present a microarray-based survey of the methylation status of CpG islands (CGIs) in 45 human atherosclerotic arteries and 16 controls. Data from 10,367 CGIs revealed that a subset (151 or 1.4%) of these was hypermethylated in control arteries. The vast majority (142 or 94%) of this CGI subset was found to be unmethylated or partially methylated in atherosclerotic tissue, while only 17 of the normally unmethylated CGIs were hypermethylated in the diseased tissue. The most common functional classes among annotated genes adjacent to or containing differentially methylated CGIs, were transcription (23%) and signalling factors (16%). The former included HOX members, PROX1, NOTCH1 and FOXP1, which are known to regulate key steps of atherogenesis. Expression analysis revealed differential expression of all CGI-associated genes analysed. Sequence analysis identified novel DNA motifs with regulatory potential, associated with differentially methylated CGIs. This study is the first large-scale analysis of DNA methylation in atherosclerosis. Our data suggest that aberrant DNA methylation in atherosclerosis affects the transcription of critical regulatory genes for the induction of a pro-atherogenic cellular phenotype.
authors.affiliation: Department of Medicine and Nutrition, Division of Health Sciences, Leon Campus, University of Guanajuato, 37000 Leon, Guanajuato, Mexico.
authors.forename: Silvia A
authors.initials: SA
authors.lastname: Castillo-Díaz
authors.forename: María E
authors.initials: ME
authors.lastname: Garay-Sevilla
authors.forename: Martha A
authors.initials: MA
authors.lastname: Hernández-González
authors.forename: Martha O
authors.initials: MO
authors.lastname: Solís-Martínez
authors.forename: Silvio
authors.initials: S
authors.lastname: Zaina
mesh_terms: D001158:Arteries / Q000473:pathology; D050197:Atherosclerosis / Q000235:genetics*; D018899:CpG Islands / Q000235:genetics*; D019175:DNA Methylation; D051858:Forkhead Transcription Factors / Q000235:genetics; D015894:Genome, Human; D018398:Homeodomain Proteins / Q000235:genetics; D006801:Humans; D010641:Phenotype; D051881:Receptor, Notch1 / Q000235:genetics; D012097:Repressor Proteins / Q000235:genetics; D025521:Tumor Suppressor Proteins / Q000235:genetics; D000098551:Prospero-Related Homeobox 1 Protein
chemical_list: C486626:FOXP1 protein, human; D051858:Forkhead Transcription Factors; D018398:Homeodomain Proteins; C497761:NOTCH1 protein, human; D051881:Receptor, Notch1; D012097:Repressor Proteins; D025521:Tumor Suppressor Proteins; D000098551:Prospero-Related Homeobox 1 Protein