Diazoxide accelerates wound healing by improving EPC function

Endothelial cell dysfunction is the primary cause of microvascular complications in diabetes. Diazoxide enables beta cells to rest by reversibly suppressing glucose-induced insulin secretion by opening ATP-sensitive K+ channels in the beta cells. This study investigated the role of diazoxide in wound healing in mice with streptozotocin (STZ)-induced diabetes and explored the possible mechanisms of its effect. Compared to the controls, mice with STZ-induced diabetes exhibited significantly impaired wound healing. Diazoxide treatment (30 mg/kg/d, intragastrically) for 28 days accelerated wound closure and stimulated angiogenesis in the diabetic mice. Circulating endothelial progenitor cells (EPCs) increased significantly in the diazoxide-treated diabetic mice. The adhesion, migration, and tube formation abilities of bone marrow (BM)-EPCs were impaired by diabetes, and these impairments were improved by diazoxide treatment. The expression of both p53 and TSP-1 increased in diabetic mice compared to that in the controls, and these increases were inhibited significantly by diazoxide treatment. In vitro, diazoxide treatment improved the impaired BM-EPC function and diminished the increased expression of p53 and TSP-1 in cultured BM-EPCs caused by high glucose levels. We conclude that diazoxide improved BM-EPC function in mice with STZ-induced diabetes, possibly via a p53- and TSP-1-dependent pathway.