Bioinformatics analysis of abnormal DNA methylation in muscle samples from monozygotic twins discordant for type 2 diabetes

The present study aimed to examine the changes in DNA methylation of gene promoters associated with type 2 diabetes (T2D). The DNA methylation profile dataset GSE38291 was downloaded from the Gene Expression Omnibus database. A paired t-test was used to analyze differences in the DNA methylation of gene promoters between T2D and normal muscle samples. Gene Ontology (GO) enrichment analysis was performed using online tool, The Database for Annotation, Visualization and Integrated Discovery. Whole-Genome rVISTA was used to analyze the enriched transcription factor (TF) binding sites upstream of the transcription start site in the differentially methylated genes. A total of 38 genes, including Sirtuin 1, N-acetyltransferase 6, phospholipase A2 group XIIB and nuclear factor of activated T cells calcineurin-dependent 1, were identified to be differentially methylated between these two groups. One GO term, DNA geometric change (GO:0032392), was significantly enriched (P<0.05) by the hyper-methylated genes. In addition, the binding sites of one gene, zinc finger E-box binding homeobox 1, and three TFs, methyl CpG binding protein 2, TFEB and TFAP4, were significantly enriched in the hyper- and hypomethylated genes, respectively. The resulting T2D-associated genes and potential TFs provided a novel insight into the molecular mechanisms underlying the pathology of T2D. These genes may become promising target genes for the development of treatments for T2D.