G-protein-mediated signaling in vascular smooth muscle cells - implications for vascular disease.

Differentiated vascular smooth muscle cells (VSMCs) are critical determinants of vascular tone and blood pressure. However, during vascular remodeling processes, which occur in response to changing hemodynamics or vascular injury, VSMCs lose most of their contractile functions in a dedifferentiation process, which goes along with cell proliferation and cell migration. VSMCs are under the constant control of a variety of mediators with vasocontractile or vasodilatory properties. Most of these mediators act through G-protein-coupled receptors, which, via different downstream signaling pathways, regulate the phosphorylation of myosin light chain and thereby control vascular tone. Recent work indicates that procontractile G-protein-mediated signal transduction pathways are also critical regulators of vascular smooth muscle dedifferentiation and redifferentiation. This review describes some of the key G-protein-mediated signal transduction pathways regulating vascular tone and VSMC differentiation and their involvement in cardiovascular diseases.