Endothelium-derived bone morphogenic protein antagonists may counteract the proatherogenic vascular effects of bone morphogenic protein 4.

In the present issue of Circulation, Chang et al1 report novel shear stress–sensitive paracrine mechanisms that regulate the activity of bone morphogenetic proteins (BMPs) in the vascular wall. BMP2 and BMP4 are structurally related members of the transforming growth factorsuperfamily. Recent studies demonstrated that vascular endothelial and smooth muscle cells are a significant source of BMPs,2–8 which regulate a host of cellular functions, including cardiovascular development,9 neovascularization in tumors,10 and smooth muscle cell chemotaxis in response to vascular injury,11 and control the balance between proliferation and activation of apoptosis in pulmonary arterial endothelial and smooth muscle cells.12