Role of smooth muscle progenitor cells in vascular mechanical injury and repair

Smooth muscle progenitor cells are precursor cells that express both smooth muscle cell and stem cell markers, and can differentiate into smooth muscle cells under specific condition. Smooth muscle progenitor cells exist in many tissues, including bone marrow, blood vessels, peripheral blood, skeletal muscle, and kidney. Smooth muscle progenitor cells play an important role in the pathogenesis of vascular diseases, like atherosclerosis, vascular mechanical injury and repair, and vascular restenosis. Cytokines and growth factors are released upon injury, which promote smooth muscle progenitor cells to proliferate and differentiate into smooth muscle cells at injured sites. Massive growth of smooth muscle cells stabilizes atherosclerotic plaques and accelerates neointima formation, which leads to vascular restenosis. Some drugs are now used to inhibit the differentiation and proliferation of smooth muscle cells to prevent neointima formation. In this review, we have summarized some recent progress on the smooth muscle progenitor cells’ origins, tissue distributions, and their role in vascular mechanical injury and repair.