Growth and phenotypic characterization of porcine coronary artery smooth muscle cells

Vascular smooth muscle cell (VSMC) proliferation significantly contributes to atherosclerotic plaque formation and limits the success rate of percutan eous transluminal coronary angioplasty. We derived a population of porcine coronary artery SMCs to characterize VSMC proliferation and phenotype in pr eparation to study the molecular actions of VSMC mitogens and antiprolifera tive agents. Growth assays were designed to minimize the estrogen content i n the culture medium, since this steroid hormone significantly influences V SMC growth and the expression of VSMC mitogens and their receptors. Culture conditions were identified such that this criterion was achieved while mai ntaining a significant VSMC growth rate. Cells cultured in serum-free mediu m, regardless of growth factor supplements, did not remain adherent to a pl astic culture substrate, nor did they proliferate. Dextran-coated charcoal (DCC)-treated sera, including fetal bovine, calf, and porcine, supported VS MC adhesion, but not growth. Whole fetal bovine serum (FBS) produced the be st proliferative response. A type-I collagen-coated culture surface signifi cantly enhanced VSMC growth, but only in culture medium containing non-DCC- treated FBS. Flow cytometry analyses confirmed the mitogenic effects of thi s substrate. The VSMCs exhibited a morphological change on type-I collagen, but this was not accompanied by a change in VSMC phenotype. Our data indic ate that culture of these porcine coronary artery SMCs in 2.5% FBS plus 10 ng platelet-derived growth factor-BE per ml in phenol red-free medium on ty pe-I collagen may be the optimal conditions for studying the molecular aspe cts of VSMC mitogens and antiproliferative agents.