Osteoarthritis, the leading cause for disability in the U.S., is the object of Dr. Chen’s study. OA is the breakdown of cartilage which may be triggered by minor damage from trauma. Findings from recent studies suggest that the degeneration in cartilage injured by physical trauma is due mainly to the accumulation and activation of a group of enzymes called metalloproteinases. These enzymes can breakdown collagen and other components of joint cartilage. A window of opportunity exists immediately after injury to prevent or reduce damage to the cartilage caused by these enzymes. Recent studies in Dr. Chen’s lab and other groups show that injury-related degeneration can be prevented in a test tube by administering TIMP-1.

TIMP-1, a natural inhibitor of metalloproteinases, is also known to play an important role in preventing cancer and improving wound healing in cardiovascular tissues. In his ANRF project, Dr. Chen takes advantage of modern molecular biology and gene therapy to study how the lack of TIMP-1 protein may affect the degenerative and repair processes of injured cartilage. He will also study whether the increasing TIMP-1 could prevent cartilage degeneration and benefit cartilage repair right after joint injury. Whereas previous studies by Dr. Chen’s group have been performed using isolated tissues in a test tube, this study will examine intact joints. Dr. Chen anticipates that the findings will provide novel insights on the role of TIMP-1 in cartilage degeneration and on treating damaged cartilage in osteoarthritis and other types of arthritis.