MIR4532 gene variant rs60432575 influences the expression of KCNJ11 and the sulfonylureas-stimulated insulin secretion.

ABSTRACT

PURPOSE: Diabetes mellitus is a major chronic disease and causes over one million deaths. KCNJ11 genetic polymorphisms influence the response of first-line oral antidiabetic agent sulfonylureas. Hsa-miR-4532 correlates with diabetic nephropathy and has a high abundance in urine. MIR4532 rs60452575 G>A variant changes the mature sequence of hsa-miR-4532. We studied whether the genetic polymorphisms of MIR4532 rs60452575 would influence KCNJ11 expression and sulfonylurea-stimulated insulin secretion or not. METHODS: To estimate the influence that rs60452575 G>A variant has on the interaction of hsa-miR-4532 and KCNJ11, we constructed a pmirGLO vector containing 3' UTR of KCNJ11 and co-transfected it with wild-type and mutant hsa-miR-4532 mimics into HEK293 cells; and we overexpressed wild-type and mutant hsa-miR-4532 mimics into HEK293 cells and MIN6 cells to access its effects on KCNJ11 expression and response of sulfonylureas. RESULTS: MIR4532 rs60452575 G>A variant appeared to disrupt the repression of KCNJ11 expression in both cell lines, and reduce the sulfonylurea-stimulated insulin secretion by breaking the binding of the hsa-miR-4532 to 3' UTR of KCNJ11 in MIN6 cells. CONCLUSIONS: Our study indicates that MIR4532 rs60452575 variant influences KCNJ11 expression and sulfonylurea response. It might be a potential predictive factor of sulfonylureas therapy.