SM22alpha modulates vascular smooth muscle cell phenotype during atherogenesis.

The function of cytoskeletal proteins in the modulation of vascular smooth muscle cell (SMC) phenotype during vascular disease is poorly understood. In this report, we used a combination of gene targeting and Cre/lox-mediated cell fate mapping in mice to investigate the role of SM22alpha, an SMC-specific cytoskeletal protein of unknown function, in the development of atherosclerosis. In hypercholesterolemic ApoE-deficient mice, genetic ablation of SM22alpha resulted in increased atherosclerotic lesion area and a higher proportion of proliferating SMC-derived plaque cells. These results identify a role for SM22alpha in the regulation of SMC phenotype during atherogenesis.