GLI family zinc finger protein 2 promotes skin fibroblast proliferation and DNA damage repair by targeting the miR‐200/ataxia telangiectasia mutated axis in diabetic wound healing

Abstract

Diabetic foot ulcer (DFU) is a serious complication of diabetic patients which negatively affects their foot health. This study aimed to estimate the role and mechanism of the miR‐200 family in DNA damage of diabetic wound healing. Human foreskin fibroblasts (HFF‐1 cells) were stimulated with high glucose (HG). Db/db mice were utilized to conduct the DFU in vivo model. Cell viability was evaluated using 3‐(4,5‐dimethyl‐2‐thiazolyl)‐2,5‐diphenyl‐2‐H‐tetrazolium bromide assays. Superoxide dismutase activity was determined using detection kits. Reactive oxygen species determination was conducted via dichlorodihydrofluorescein‐diacetate assays. Enzyme‐linked immunosorbent assay was used to evaluate 8‐oxo‐7,8‐dihydro‐2′deoxyguanosine levels. Genes and protein expression were analyzed by quantitative real‐time polymerase chain reaction, western blotting, or immunohistochemical analyses. Luciferase reporter gene and RNA immunoprecipitation assays determined the interaction with miR‐200a/b/c‐3p and GLI family zinc finger protein 2 (GLI2) or ataxia telangiectasia mutated (ATM) kinase. HG repressed cell proliferation and DNA damage repair, promoted miR‐200a/b/c‐3p expression, and suppressed ATM and GLI2. MiR‐200a/b/c‐3p inhibition ameliorated HG‐induced cell proliferation and DNA damage repair repression. MiR‐200a/b/c‐3p targeted ATM. Then, the silenced ATM reversed the miR‐200a/b/c‐3p inhibition‐mediated alleviative effects under HG. Next, GLI2 overexpression alleviated the HG‐induced cell proliferation and DNA damage repair inhibition via miR‐200a/b/c‐3p. MiR‐200a/b/c‐3p inhibition significantly promoted DNA damage repair and wound healing in DFU mice. GLI2 promoted cell proliferation and DNA damage repair by regulating the miR‐200/ATM axis to enhance diabetic wound healing in DFU.