Inhibition of miR-181c-5p Rescues Diabetes-Impaired Angiogenesis in Ischemia and Wound Healing.

Abstract

Diabetes-related vascular complications are characterized by impaired ischemia-driven angiogenesis and delayed wound healing. MicroRNAs (miRNAs) are emerging as powerful targets for multifaceted diseases. We previously identified that miRNA-181c-5p has anti-angiogenic properties, but its role in diabetes is unknown. In a hindlimb ischemia model, streptozotocin-rendered diabetic mice treated with an miRNA-181c-5p inhibitor (anti-miR-181c-5p) exhibited improved blood flow reperfusion and increased arteriolar density, compared with diabetic anti-miR-negative (anti-miR-Neg) control mice. Diabetic anti-miR-Neg mice had reduced perfusion relative to nondiabetic control mice. In a murine wound-healing model, inhibition of miRNA-181c-5p rescued diabetes-impaired wound closure rate and increased capillary density, whereas diabetic anti-miR-Neg wounds healed more slowly than nondiabetic anti-miR-Neg wounds. In vitro, inhibition of miRNA-181c-5p increased endothelial tubule formation and cell migration under high-glucose conditions. Mechanistically, anti-miR-181c-5p elevated VEGFA and VEGFR2 protein expression, ERK2 phosphorylation, and Bcl2 mRNA levels. Whole-transcriptome sequencing identified two genes (Elmo3 and Trib1) that were upregulated in anti-miR-181c-5p-treated hindlimbs and wounds. Luciferase assays confirmed VEGFA as a likely direct target of miR-181c-5p, whereas ERK2, ELMO3, and TRIB1 are indirectly regulated. These findings demonstrate that miRNA-181c-5p inhibition promotes angiogenesis and improves vascular repair in diabetes, identifying miRNA-181c-5p as a potential therapeutic target for preventing diabetic vascular complications. We found that patients with diabetic vascular complications have elevated circulating levels of miR-181c-5p, an antiangiogenic microRNA. We tested whether inhibition of miR-181c-5p increases angiogenesis in diabetic hindlimb ischemia and wound-healing models and elucidated its mechanisms of action. miR-181c-5p inhibition rescues diabetes-impaired ischemia-driven angiogenesis and wound healing and increases endothelial angiogenic capacity. This was concomitant with increases in VEGFA, VEGFR2, ERK2 phosphorylation, Bcl2, Elmo3, and Trib1. VEGFA is a likely direct target of miR-181c-5p, whereas ERK2, ELMO3, and TRIB1, although upregulated after miR-181c-5p inhibition, are indirectly regulated downstream. miR-181c-5p inhibition represents a promising therapeutic strategy for diabetic vascular complications.