In 1995 nearly 71,000 Americans received heart-valve replacements, according to the American Heart Association. The primary reason is bone-formation within the valves due to age, congenital conditions, and disease. In an effort to better understand the biochemical pathways that lead to the condition, Emile R. Mohler, III, MD, director of vascular medicine at the University of Pennsylvania Medical Center, set out to look for bone-making proteins in calcified aortic valves.

Mohler and colleagues found osteopontin, a protein that makes up the molecular scaffolding to which calcium sticks in the formation of bone. "We're the first group, to my knowledge, to directly isolate osteopontin in calcified valves," notes Mohler. "Identifying the molecular mechanisms underlying ossification of valves could lead to novel therapies to prevent or treat valve disease." In addition, the work may help to determine how calcium deposits form in the arteries of people with atherosclerosis and other vascular diseases. The group suspects that cells commonly enlisted in fighting inflammation associated with heart disease somehow trigger the calcification process seen in the valves. This work appeared earlier this year in Atherosclerosis, Thrombosis, and Vascular Biology.

Note: Dr. Mohler can be reached at 215-662-9016.