Cholesterol accumulation in vascular smooth muscle cells incorporated into platelet-rich plasma clots.

Thrombus formation is thought to contribute to the growth of atherosclerotic lesions. Lipid-containing cells accumulate within thrombi as they become organized and incorporated into atherosclerotic lesions. This study examined cholesterol accumulation within vascular smooth muscle cells in clots formed in vitro from platelet-free and platelet-rich plasma. The fluorescent cholesterol probe filipin was used to detect cholesterol within the clots. Smooth muscle cells accumulated cholesterol when included within clots formed from platelet-rich plasma. Smooth muscle cells did not accumulate cholesterol when included within plasma clots lacking platelets. Thus, platelets in some way can induce cholesterol accumulation within vascular smooth muscle cells. This finding may be relevant to the cholesterol accumulation within vascular smooth muscle cells that occurs during atherogenesis.