Sphingolipid mediators in cardiovascular cell biology and pathology

Sphingolipids have emerged as a new class of lipid mediators. In response t o various extracellular stimuli, sphingolipid turnover can be stimulated in vascular cells and cardiac myocytes. Subsequent generation of sphingolipid molecules such as ceramide, sphingosine, and sphingosine-1-phosphate, is f ollowed by regulation of ion fluxes and activation of various signaling pat hways leading to smooth muscle cell proliferation, endothelial cell differe ntiation or apoptotic cell death, cell contraction, retraction, or migratio n. The importance of sphingolipids in cardiovascular signaling is illustrat ed by recent observations implicating them in physiological processes such as vasculogenesis as well as in frequent pathological conditions, including atherosclerosis and its complications.