Ginsenoside (Rg-1) promoted the wound closure of diabetic foot ulcer through iNOS elevation via miR-23a/IRF-1 axis

Background: Impaired wound healing in diabetes foot ulcers (DFUs) brings a great burden to diabetic patients. Pro-angiogenesis through elevating nitric oxide (NO) is beneficial to the wound healing process. Ginsenoside Rg1, the main active in Notoginseng, is reported to regulate the angiogenesis in endothelial cells through modulating miR-23a. However, the effect of Rg1 in diabetes remains elusive. Methods: High fat diet combined with streptozotocin-induced diabetic rats were treated with Rg1. Then incision area and tissue NO level were measured to evaluate the wound closure efficacy of Rg1. Then high glucose cultured HUVECs were employed to mimic diabetic environment in vitro. Overexpression and knockdown plasmids of miR-23a or IRF-1 were constructed and transfected in HUVECs. qPCR and western blot were used to determine the mRNA and protein level, respectively. Dual-luciferase reporter assay was utilized to determine the interaction of IRF-1/miR-23a. Results: Rg1 accelerated the wound closure speed in diabetic rats and increased NO level through elevating iNOS expression. Knockdown of iNOS reversed Rg1-induced VEGF expression, cell proliferation, anti-apoptotic efficacy and cell migration ability in high glucose cultured HUVECs. Further investigation revealed that Rg1 mediated iNOS through miR-23a. miR-23a inhibited the expression of IRF-1, a protein which could directly bind to the iNOS mRNA 3'UTR. Conclusion: Rg1 promoted angiogenesis in diabetic wound healing process through NO signaling via miR-23a, providing a novel candidate for DFUs treatment.