演題名: Mkxを介した腱・靭帯のメカノシグナルの調節機構 Mechano-signal pathway regulating tendon and ligament via Mkx 抄録本文: Despite the unique and important role of tendons/ligaments in musculoskeletal function and disease, research in this area is not as advanced as in most other skeletal tissues. This is partly because critical and specific transcr iption factors had not been elucidated. In this regard, we identified Mohawk (Mkx) as a specific and critical transcription factor for tendon and ligame nt development. Mkx is expressed specifically in tendon and ligament cells during embryogenesis and Mkx-deficient mice have hypoplastic tendons throughout the body and deficient type I collagen production in tendon cells. Importantly, we have also found that Mkx expression is maintained in mature tendon/ligament cells in mice and human and demonstrated that MKX expression is clearly decreased in ligaments from patients with OA, correlating deficient expression of important ECM genes such as COL1A1 and TNXB. These findings may reflect a feature of degenerated ACL in OA-affected joints. From another aspect, we showed that MKX expression enhances tendon/ligament differentiation from mesenchymal stem cells, suggesting that MKX could be a tool for tendon/ligament tissue regenerative medicine. Taken together, MKX has been shown to be necessary not only for development but also to maintain the tissue homeostasis and regeneration in adult human tendons and ligaments.