DNA methylation status of CpG islands in normal and atherosclerotic human arteries

ABSTRACT: Abnormal epigenetic gene regulation may play a pivotal role in atherogenesis. In particular, global DNA hypomethylation potentially leading to proatherogenic gene expression, occurs in atherosclerotic lesions in humans and animal models. In order to identify genomic sequences targeted for DNA hypomethylation in atherosclerosis, we analysed the methylation status of CpG islands (CGIs) in 45 human arteries with advanced atherosclerotic lesions and 16 normal counterparts by a microarray approach. Methylation data for 10,367 CGIs revealed that a subset (1.5%) of such sequences was hypermethylated in normal arteries, in accordance with data previously obtained in peripheral blood cells. Ninety-four per cent of this CGI subset was demethylated in atherosclerotic tissue, while only 17 of normally hypomethylated CGIs was hypermethylated in diseased tissue. A functional classification of genes physically associated with differentially methylated CGIs revealed a bias towards transcription factors (42%). The latter include HOX members, NOTCH1 and FOXP1, which are known to regulate angiogenesis, dedifferentiation, cell migration and macrophage function. The methylation status of selected CGIs was validated in further 10 subjects for either group. Expression patterns of these factors were compatible with the observed differential methylation. Our data suggest that one of the molecular changes associated with aberrant DNA methylation in advanced atherosclerosis is the regulation of critical transcription factor genes for the induction of a proatherogenic cellular phenotype. Two-condition experiment, i.e. normal vs. atherosclerotic arteries. 16 and 45 normal and atherosclerotic samples, respectively, were pooled and used to interrogate CpG island arrays in triplicate, for a total of six arrays. Each array was co-hybridized with untreated DNA (reference) and hypermethylated DNA obtained by biochemical filtration.

ORGANISM(S): Homo sapiens

SUBMITTER: María Garay-Sevilla 

PROVIDER: E-GEOD-15552 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress