Development of Chondro-regenerative Therapies for Osteoarthritis Project Overview Translating our understanding of the molecular pathogenesis of osteoarthritis into novel therapies is a central goal of our research. Since a significant fraction of the >25 million osteoarthritis patients in the US have developed the disease because of an earlier traumatic injury to the joint, we have employed a mouse model of posttraumatic osteoarthritis as the platform for the study of candidate therapies aimed at attacking the central problem in the disease: loss of cartilage. Our current focus is on the chondro-regenerative impact of PTH, which has been pursued because of the well established ability of this hormone (and its cousin PTHrP) to inhibit chondrocyte hypertrophy and induce cartilage matrix production. We have found that following meniscal injury to the knee, mice administered PTH display decelerated progression of disease associated with significant chondro-regeneration. Given that PTH is an already FDA-approved therapy of osteoporosis, these pre-clinical findings in the context of osteoarthritis can be rapidly translated to the design and execution of a clinical trial to test the efficacy of the drug in patients.