The present study aimed to investigate the expression of microRNA (miR)-185 in the bone and blood tissues following ankle fracture, and its regulatory mechanism in the ankle fracture recovery process. In total, 28 patients with ankle fractures were included, including 15 cases receiving surgical treatment within 1-7 days after fracture, and 13 cases receiving surgery within 8-14 days after fracture. Reverse transcription-quantitative polymerase chain reaction was performed to detect the mRNA expression levels. Western blot analysis and ELISA were used to determine the protein expression levels. Bioinformatics analysis and dual-luciferase reporter assay were applied to predict and confirm the upstream regulator of tumor growth factor (TGF)-β1. An MTT assay was performed to assess the cell proliferation. Compared with the 1-7-day surgery group, the mRNA and protein expression levels of TGF-β1 were significantly elevated, while the expression levels of miR-185 were significantly declined in the bone and blood tissues in the 8-14-day surgery group. Bioinformatics analysis and dual-luciferase reporter assay predicted and confirmed that TGF-β1 was the direct target gene of miR-185. Moreover, upregulated expression of miR-185 significantly decreased the protein expression levels of TGF-β1 and reduced the proliferating activity of hFOB1.19 cells. Within two weeks after ankle fracture, the expression levels of TGF-β1 are significantly upregulated in the bone and blood tissues, which may have been associated with the downregulated expression of miR-185. miR-185 may modulate TGF-β1 to regulate the recovery of ankle fracture. These findings may contribute to the understanding of the biological functions and effects of miRNA-185 and TGF-β1 in ankle fractures.
Keywords: TGF-β1; ankle fracture; dual-luciferase reporter assay; microRNA-185; recovery process.