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.