Decreased expression of miR‐204‐3p in peripheral blood and wound margin tissue associated with the onset and poor wound healing of diabetic foot ulcers

To investigate the relationship between small non‐coding RNA‐204‐3p (miR‐204‐3p) and the onset and wound healing of diabetic foot ulcers (DFU) and the underlying molecular mechanism, sixty four newly diagnosed patients with T2DM without DFU (T2DM group), 82 T2DM patients with DFU (DFU group), and 60 controls with normal glucose tolerance (NC group) were included. Quantitative real‐time PCR (qRT‐PCR) method was used to determine miR‐204‐3p expression levels in peripheral blood and wound margin tissue of subjects, and to analyse the relationship between the expression of miR‐204‐3p and wound healing. In vitro experiments were also performed to understand the effect of miR‐204‐3p on high glucose induced injury of HaCaT cells (human keratinocytes). The results showed that miR‐204‐3p expression level of peripheral blood in the T2DM group was marked lower than that in the NC group [2.38 (1.31‐5.04) vs 3.27 (1.51‐6.98)] (P < .05). Similarly, the miR‐204‐3p expression level of peripheral blood in the DFU group was significantly lower than the T2DM group [1.15 (0.78‐2.89) vs 2.38 (1.31‐5.04)] (P < .01). The expression level of miR‐204‐3p in peripheral blood and wound margin tissues of DFU patients was positively correlated with the healing rate of foot ulcers after 8 weeks (P < .05). Multifactorial logistic regression analysis showed that decreased expression of miR‐204‐3p in peripheral blood was an independent risk factor for DFU (OR = 2.95, P < .05). The results of in vitro experiments showed that miR‐204‐3p could improve the proliferation and migration of HKC cells and reduce the proportion of apoptosis of HKC cells by targeted regulation of zinc finger protein Kruppel like factor 6 (KLF6) in high glucose environment. Therefore, the decreased expression of miR‐204‐3p in peripheral blood and wound tissue of T2DM patients is closely related to the occurrence and poor wound healing of DFU. The down‐regulated expression of miR‐204‐3p can reduce its ability to antagonise the functional damage of keratinocytes induced by high‐glucose conditions. These results will provide potential targets for the treatment of DFU.