Role of Mast Cell in Formation and Rupture of Atherosclerotic Plaque

Mast cells,an inflammatory cell type,play an important role in early and late stages of human atherosclerotic lesions.The vitro studies suggested that mast cells activated not only proteolyze low-density lipoproteins,which accelerates cellular cholesterol accumulation,but also proteolyze high-density lipoproteins,which prevents cellular efflux of cholesterol.Thus,these mast cells promote the conversion of both macrophages and smooth muscle cells into foam cells.In addition,mast cells can trigger destabilization of the plaque by activating matrix metalloproteinase,facilitating extracellular matrix degradation,inhibiting smooth muscle cells proliferation and inducing them apoptosis,inhibiting collagen synthesis,and by accelerating neovascularization.These findings above suggested that mast cells play a significant role in both formation and rupture of atherosclerotic plaques.