Effect of metformin on the expression of SNAER proteins in the skeletal muscle of rats with type 2 diabetes

SNARE proteins are composed of a combination of SNAP-23, Stx-4, and VAMP-2 isoforms that are significantly expressed in skeletal muscle. These proteins control the transport of GLUT4 to the cell membranes. The modifications in the expression of SNARE proteins can cause Type 2 diabetes. The present study aimed to assess the effect of metformin on the expression of these proteins in rats.

For the purpose of the study, 40 male Wistar rats were randomly selected. Streptozotocin and Nicotinamide were used for the induction of type 2 diabetes. The animals were assigned to five groups (n=8), including healthy and diabetic groups as control, as well as three experimental groups which were treated with different doses of metformin (100, 150, and 200 mg/kg body weight) for 30 days. The quantitative reverse transcription PCR (RT-qPCR) method was applied to evaluate the expression of SNARE complex proteins..

Based on the results, metformin (100, 150, and 200 mg/kg body weight) decreased serum glucose levels and increased serum insulin levels. This difference in dose of 200 mg/kg body weight was statistically significant (P<0.05). Moreover, all three doses of metformin increased the expression of SNAP- 23, syntaxin-4, and VAMP-2 proteins in skeletal muscle tissue. Metformin at a dose of 200 mg/kg body weight demonstrated the most significant effects (P<0.05).

As evidenced by the results of the current study, another anti-diabetic mechanism of metformin is to increase the expression of SNARE proteins, which effectively improves insulin resistance and lowers blood glucose.