Altered expression of α-actin, smooth muscle myosin heavy chain-1 and calponin in cultured smooth muscle cells by oxidized low density lipoproteins

The expression of the contractile proteins, alpha-actin, smooth muscle myosin heavy chain-1 (SM1) and calponin present in smooth muscle cells (SMC) in the presence of oxidized low density lipoproteins (oxLDL) was investigated in two different cell cultures: the mouse smooth muscle cell line SVSC and rat smooth muscle cells (RSMC). Exposure of the cells to 187 mu g protein/ml oxLDL for 24 h reduced the expression of all three contractile proteins in both cell cultures when compared to cells incubated in the presence of native LDL. This investigation of the response of SMC contractile proteins to oxLDL mag provide further insights into the mechanisms by which oxidatively modified LDL is atherogenic and suggests that oxLDL may contribute to the regulation of the expression of the genes responsible for the synthesis of smooth muscle cell contractile proteins. (C) 1998 Federation of European Biochemical Societies.