Effective knock down of matrix metalloproteinase‐13 by an intra‐articular injection of small interfering RNA (siRNA) in a murine surgically‐induced osteoarthritis modelRyuichiro Akagi Takahisa Sasho Masahiko Saito Jun Endo Satoshi Yamaguchi Yuta Muramatsu Shunsuke Mukoyama Yorikazu Akatsu Joe Katsuragi Taisuke Fukawa Kazuhisa Takahashi
This study investigated the effect of MMP‐13 gene knock down on cartilage degradation by injecting small interfering RNA (siRNA) into knee joints in a mouse model of osteoarthritis (OA). OA was induced in male C57BL/6 mice by destabilization of medial meniscus (DMM) surgery. Change of Mmp13 expression over time was determined by qPCR analysis from 3 days to 6 weeks after surgery. Mmp13 and control chemically modified siRNA were injected into the knee joint 1 week after surgery and expression levels were assessed in synovium by qPCR 48 h later. Cartilage degradation was histologically assessed 8 weeks after DMM surgery according to OARSI recommendations. Mmp13 expression levels were elevated 1 week after surgery and peaked at 77 fold at 2 weeks compared to expression at 3 days. A 55% decrease of Mmp13 levels in cartilage was observed 48 h after injection of Mmp13 siRNA (p = 0.05). Significant reduction in the histological score at 8 weeks after surgery was observed in the Mmp13 siRNA‐treated group compared to the control siRNA group (p < 0.001). Intra‐articular injection of Mmp13 siRNA at the early phase of OA development resulted in effective knock down of Mmp13 expression and delay in cartilage degradation in vivo.