Connexins in atherosclerosis.

Remodeling of the vascular wall plays a central role in many physiological processes, but also in the pathogenesis of cardiovascular diseases such as atherosclerosis and restenosis. Atherosclerosis represents the major cause of death and disability in adult populations of Western societies. Angioplasty is a common and effective method of treatment for coronary atherosclerosis, but restenosis after the procedure continues to be a serious clinical complication. The development of atherosclerosis and restenosis involves complex patterns of interactions between the dysfunctional endothelium, inflammatory cells and smooth muscle cells in which cytokines and growth factors are known to play a critical role. Apart from paracrine cell-to-cell signaling, a role for gap-junction-mediated intercellular communication has recently been suggested. In this chapter, we summarize existing evidence supporting such a role. Thus, the pattern of vascular connexins is altered during atherosclerotic plaque formation and in restenosis. In addition, disturbances in flow, inflammation and smooth muscle cell activation and proliferation have been shown to affect connexin expression or gap junctional communication. Finally, genetically modified connexin expression alters the course of these diseases in mice. Further studies will tell us whether future treatment of atherosclerosis or restenosis may involve connexin-based strategies.