Abstract
Diabetic foot ulcer (DFU) is a chronic and non-healing complication of diabetes that leads to high hospital costs and, in extreme cases, to amputation. Recent studies have reported that long non-coding RNAs (lncRNAs) are linked to various diabetes-related symptoms. Thus, we aim to explore the role of lncRNA H19 in the wound healing process following DFU. Fibroblasts were isolated from the ulcer margin tissues of DFU patients, with the expression of lncRNA H19, connective tissue growth factor (CTGF) or serum response factor (SRF) altered by lentivirus infection. Next, rat models of DFU induced by high glucose and lipid diet were established, which was also infected with corresponding lentivirus. The interaction among lncRNA H19, SRF and CTGF was determined. Afterwards, cell proliferation and apoptosis, angiogenesis, ECM remodeling and wound healing in DFU tissues were evaluated to explore the effects of lncRNA H19/SRF/CTGF and MAPK signaling pathway on DFU. CTGF was poorly expressed in ulcer tissues from DFU rats and patients. CTGF overexpression was shown to activate the MAPK signaling pathway to promote cell proliferation, ECM remodeling, angiogenesis and wound healing while inhibiting cell apoptosis. LncRNA H19 was validated to elevate CTGF expression by recruiting SRF to the promoter region of CTGF, thus accelerating cell proliferation, ECM remodeling and wound healing while repressing cell apoptosis. Furthermore, MAPK signaling pathway activation is confirmed to be the underlying mechanism behind lncRNA H19/CTGF/SRF-induced results. Thus, lncRNA H19 accelerated wound healing in DFU through elevation of CTGF and activation of the MAPK signaling pathway.