Nutritional Control, Gene Regulation, and Transformation of Vascular Smooth Muscle Cells in Atherosclerosis

Abstract

Contractile-state smooth muscle cells (SMC), the only cell type in the arterial media, undergoes migration to the intima, proliferation, and abundant extracellular matrix production during the early stages of atherosclerosis. This involves the ingestion of low-density lipoprotein (LDL) and modified or oxidised LDL by macrophages together with SMC by several pathways including a scavenger pathway leading to accumulation of cholesterol esters and formation of foam cells. High-plasma cholesterol levels constitute a major causative risk for atherosclerosis. The membrane-bound transcription factor called sterol regulatory element binding protein (SREBP) activates gene-encoding enzymes of cholesterol and fatty acid biosynthesis. The SREBP expression, in response to diet, shows that are involved in both lipogenesis and cholesterol homeostasis, moreover SREBPs are regulated directly by cholesterol. Animal models were used in trials of atherosclerosis, and cholesterol feeding has been described elsewhere as producing atherosclerotic lesions. We have examined the morphological, molecular and proliferative change in arterial SMC mimicking such a cholesterol diet, this transformed SMC is a good model to study the alterations of the differentiated state of SMC, and the transformation into foam cell, caused by cholesterol-rich diet. Despite the complexity of the interactions in atherosclerosis, there are many opportunities to affect the homeostatic balance of the artery wall at SMC levels. We have considered here some of the possible targets for intervention with promising strategies for the nutritional control of the genes, and, in a general way, the possibilities for modulating the expression of genes influencing atherosclerosis.