Separate Cell Metabolism papers show that SIRT1 promotes response while GSK-3 inhibits it.
Independent studies that will be published in the October 3 edition of Cell Metabolism identified two proteins involved in insulin sensitivity in type 2 diabetes.
Chinese Academy of Sciences’ (CAS) investigators report that increased levels of the SIRT1 enzyme improved insulin sensitivity in mice. Earlier studies had reported a connection between SIRT1 and the processes of glucose metabolism and insulin secretion, although no direct link had been shown.
The CAS team observed that SIRT1 levels are reduced in insulin-resistant cells and tissues and that treatments that block the enzyme’s function lead to insulin resistance.
The scientists say that administering resveratrol, which is known to activate SIRT1 and is found in red grapes and wine, at a dose of 2.5 mg/kg/day enhanced insulin sensitivity in cells. This dose of resveratrol also reportedly reduced insulin resistance in animals fed a high-fat diet, the investigators showed.
In the second study, a team of Mount Sinai Hospital researchers found that the elimination of the gene for glycogen synthase kinase-3 (GSK-3) in mice sensitizes the animals to insulin.
