Circ_0136474 and MMP‐13 suppressed cell proliferation by competitive binding to miR‐127‐5p in osteoarthritis

Osteoarthritis (OA) is a prevalent degenerative joint disease whose pathogenesis remains unclear. The research aims to investigate the roles of Circ_0136474/miR‐127‐5p/MMP‐13 axis in OA. Differentially expressed circRNAs and miRNAs in OA cartilage tissue were screened out and visualized by R project based on RNA‐seq data and microarray data respectively. qRT‐PCR was carried out for detection of relative expression levels of Circ_0136474, miR‐127‐5p, MMP‐13 and other inflammatory factors and Western blot analysis was conducted to detect the protein expression level of MMP‐13. CCK‐8 assay and flow cytometry were conducted to determine cell proliferation and cell apoptotic ability respectively. RNA‐fluorescence in situ hybridization (RNA‐FISH) experiments were conducted to confirm the immune‐localization of the Circ_0136474 and MMP‐13 in human tissues. Targeted relationships were predicted by bioinformatic analysis and verified by dual‐luciferase reporter assay. Our findings revealed that the expression levels of both Circ_0136474 and MMP‐13 in OA cartilage tissue were significantly higher than that in normal cartilage tissue. Circ_0136474 could suppress cell proliferation by facilitating MMP‐13 expression and suppressing miR‐127‐5p expression in OA. Overexpression of miR‐127‐5p negatively regulated MMP‐13 expression to enhance cell proliferation. Our study demonstrated that Circ_0136474 and MMP‐13 suppressed cell proliferation, while enhanced cell apoptosis by competitive binding to miR‐127‐5p in OA, which may well provide us with a new therapeutic strategy for osteoarthritis.