Epigenetics of diabetes Type 2 have shown that miRNAs have pivotal roles in many different gene regulatory pathways. A subset of miRNAs has been shown to be involved in metabolic regulation of glucose homeostasis and in epigenetics of diabetes type 2. Pancreatic islet-specific miR-375 inhibits insulin secretion in mouse pancreatic β-cells by inhibiting the expression of the protein myotrophin. An overexpression of miR-375 can completely suppress glucose-induced insulin secretion, while inhibition of native miR-375 will increase insulin secretion. In another study, increasing the level of miR-9, a different miRNA, resulted in a severe defect in glucose-stimulated insulin release. This happens because miR-9 down-regulated the transcription
Epigenetics of diabetes Type 2 found that there was an approximately twofold increase in DNA methylation of the PPARGC1A promoter of human islet cells from diabetics as compared to non-diabetic human islet cells. This means that expression from the PPARGC1A genes were turned down in the diabetic patients. Further testing revealed that the more PPARGC1A was expressed, the more insulin was released from the islets, and as expected, in diabetic patients there was less PPARGC1A expressed and also less insulin secreted. This data supports the idea that PPARGC1A expression is reduced in animal models of diabetes and human diabetes and is associated with impaired insulin