In Vivo Fluorescence Reflectance Imaging of Protease Activity in a Mouse Model of Post-Traumatic Osteoarthritis

摘要

ObjectiveTraumatic joint injuries initiate a surge of inflammatory cytokines and proteases that may contribute to cartilage and subchondral bone degeneration. Detecting these early biological processes in animal models of post-traumatic osteoarthritis (PTOA) typically involves ex vivo analysis of blood serum or synovial fluid biomarkers, or destructive histological analysis of the joint. In this study, we used in vivo fluorescence reflectance imaging (FRI) to quantify protease activity, matrix metalloproteinase (MMP) activity, and Cathepsin K activity in mice following ACL rupture. We hypothesized that these processes would be elevated at early time points following traumatic joint injury (1–14 days), but would return to control levels at later time points (4–8 weeks).