Effects of Insulin and Glucose on Cellular Metabolic Fluxes in Homocysteine Transsulfuration, Remethylation,<i>S</i>-Adenosylmethionine Synthesis, and Global Deoxyribonucleic Acid Methylation

Abstract

We demonstrated the novel finding of a direct promoting effect of high cellular insulin or glucose exposure on homocysteine remethylation, adoMet synthase activity, and adoMet synthesis. We also provided new evidence indicating that when hepatic tissue is exposed to elevated insulin or glucose, the cellular methylation balance can be altered, which may have potential epigenetic impacts gene regulation in diabetic individuals. These findings in a cell line may or may not reflect what happens in humans. In vivo studies on the homocysteine transmethylation fluxes and DNA methylation in diabetic state are underway.