Genes and Genetic Mechanisms Modulating Maturation and Repair of Articular Cartilage and Responses to Intra-Articular Glucocorticoid Therapy

Significance ofproblem: Joint disease and the resulting lameness eventually limit the athletic careers of most horses. While the importance of j oint cartilage to soundness is widely appreciated, our knowledge is quite limited on several fundamental questions. How does the normal function of cartilage change as a horse matures? When a horse starts into fast or heavy work, how does healthy cartilage respond to the associated increases in biomechanical stresses placed on the joints? Why is cartilage normally unable to repair a lesion in the joint surface and fully restore its structural and biomechanical integrity? What can be done therapeutically to improve the ability of articular lesions to heal? This project will provide information relevant to these questions by analyzing patterns of gene expression in the cells that synthesize and maintain cartilage. The longterm goal is to generate important new knowledge about the function of chondrocytes thatcan be used to help horses remain sound and develop improved methods of treatment for cartilage injuries.