Mitomycin C induces fibroblast apoptosis and reduces intra-articular scar adhesion by regulating miR-21 and its target Programmed cell death 4

Abstract Previous studies have shown that mitomycin C (MMC) can prevent scar adhesion after joint surgery, but the specific mechanism underlying this effect remains unclear. The purpose of this study was to explore the specific mechanism by which MMC promotes fibroblast apoptosis and prevents joint adhesion. The effect of MMC on fibroblasts was assessed using cell counting kit-8 (CCK-8) assays, western blotting, and TUNEL staining. We used qRT-PCR to measure the expression of miR-21 in fibroblasts treated with MMC. Luciferase activity assays were used to determine the relationships between miR-21 and Programmed cell death 4 (PDCD4). The effects of miR-21 and PDCD4 on fibroblast apoptosis were assessed using flow cytometry and western blotting. HE staining was used to determine the role of miR-21 in scar tissue formation in a model of joint adhesion. The results showed that MMC induced apoptosis of fibroblasts and decreased the expression of miR-21. Moreover, miR-21 down-regulation also induced apoptosis of fibroblasts. PDCD4 was confirmed to be a direct target of miR-21 by luciferase activity assay. The results from the animal model indicated that miR-21 attenuated the effect of MMC on reducing the number of fibroblasts. Our study shows that MMC can induce fibroblast apoptosis and prevent joint adhesion by regulating the expression of miR-21 and its target PDCD4.