Cigarette smoking is a known risk factor for arteriosclerosis. In atheromatous plaques, the accumulation of vascular smooth muscle cells (VSMCs) have a phenotype differing from that of their normal contractile type. Nicotine is a major pharmacological agent in cigarette smoke. However, any direct effect of nicotine on VSMCs remains uncertain. We investigated the changes in the expression levels of differentiation markers and activity of mitogen-activated protein kinases (MAPKs) after nicotine exposure for 48 h using human aorta primary smooth muscle cells (HVSMC) differentiated with transforming growth factor-β. The results indicated that HVSMC phenotype changed to a synthetic-like phenotype after nicotine exposure. Nicotine is a factor that can change the expression of differentiation marker proteins in VSMCs. Thus, we proposed that nicotine directly affects the migration of VSMCs from the tunica media to atheromatous plaques in the vascular intima by inducing the transformation from a contractile-type to a synthetic-like type, which occurs before the development of atheromatous plaques. Nicotine is contained in nicotine patches and gums for smoking cessation. There may also promote atheromatous plaque formation. We anticipate that determining this mechanism will lead to new means of preventing and treating plaque formation and development in arteriosclerosis.
Part of the book: Atherosclerosis