Abstract: BACKGROUND: miRNAs expression has been reported to be associated with hepatic and renal fibrosis, and dermal fibrogenesis. Moreover, a targeted regulatory relationship between miR-192-5p and epidermal regulators has been demonstrated in gouty arthritis.
OBJECTIVE: To investigate the expression and regulatory role of miR-192-5p in hypertrophic scar and to verify whether there is a targeted regulatory relationship between miR-192-5p and epidermal regulators.
METHODS: (1) Six cases of hypertrophic scar tissue and six cases of normal skin tissue were collected from the First Affiliated Hospital of Xinjiang Medical University. And miR-192-5p and epidermal regulator mRNA expression were detected by qRT-PCR. (2) The primary hypertrophic scar fibroblasts were obtained using tissue explant method and cultured to 3-6 generations for subsequent experiments. There were three groups in the experiment: negative control group, miR-192-5p mimic group and miR-192-5p inhibitor group. The latter two groups were transfected with the corresponding sequences. Cell proliferation viability was detected by the cell counting kit-8 assay and EdU kit; and the migration ability was detected by the cell scratch test. Cell apoptosis was detected by flow cytometry. The gene and protein expressions of epidermal regulator, type I collagen, type III collagen and α-smooth muscle actin were detected by qRT-PCR and western blot, respectively. miR-192-5p targets were predicted by a bioinformatics website, and target binding was validated by dual luciferase assay. 
RESULTS AND CONCLUSION: (1) Compared with normal skin tissues and their fibroblasts, miR-192-5p and epidermal regulator were highly expressed in hypertrophic scar and hypertrophic scar fibroblasts (P < 0.05 or P < 0.01). (2) After overexpression of miR-192-5p, cell proliferation was enhanced (P < 0.05) and EdU positive cell rate increased (P < 0.01) when compared with the negative control group; after inhibition of miR-192-5p, cell viability (P < 0.05) and EdU positive rate decreased (P < 0.05). (3) At 24 hours after overexpression of miR-192-5p, compared with the negative control group, the area between cell scratches and apoptosis rate decreased in the miR-192-5p mimic group (P < 0.05) but increased in the miR-192-5p inhibitor group (P < 0.01). (4) At 48 hours after transfection, the mRNA and protein levels of epidermal regulator were significantly decreased in the miR-192-5p mimic group, while the mRNA and protein levels of type I collagen, type III collagen and α-smooth muscle actin were significantly increased (P < 0.05 or P < 0.01). The miR-192-5p inhibitor group showed opposite changes in the above four indicators (P < 0.05 or P < 0.01). (5) The Targetscan website predicted that epidermal regulator had a potential binding site for miR-192-5p. (6) Dual luciferase assays showed that miR-192-5p could bind to epidermal regulator in a targeted manner. To conclude, overexpression of miR-192-5p can decrease the expression of epidermal regulator, and the two may be negatively regulated, suggesting that regulation of epidermal regulator may play a role in inhibiting the proliferation of hypertrophic scar fibroblasts.

中国组织工程研究杂志出版内容重点：组织构建；骨细胞；软骨细胞；细胞培养；成纤维细胞；血管内皮细胞；骨质疏松；组织工程

Key words: hypertrophic scar, miR-192-5p, epidermal regulator, fibroblast