title: Resting smooth muscle cells as a model for studying vascular cell activation.
abstract: Vascular smooth muscle (VSM) cells constitute the main structural components of tunica media. Under physiological conditions, these cells display a contractile phenotype and a low proliferative activity. However, they may also acquire a synthetic phenotype and become predominantly proliferative if stimulated under certain stress conditions. This capacity plays a major role in the inception and progression of such cardiovascular diseases as atherosclerosis, hypertension and restenosis. Porcine coronary smooth muscle (PCSM) cells exhibit a synthetic phenotype (ON cells) under standard culturing conditions, but they can be reverted to a contractile phenotype (OFF cells) in a serum-free medium. However, OFF cells can also re-acquire a synthetic phenotype (OFF/ON cells) upon serum administration. In the present study, proliferative and contractile behaviors were characterized by expression of specific differentiation markers. Taken together, these results demonstrate that porcine vascular smooth muscle cells can retain their phenotypic plasticity in culture, and thus mimic in vitro their in vivo differentiation states. OFF cells may thus provide a suitable model system in studying the mechanism(s) by which either known or unknown serum factors may trigger vascular smooth muscle activation. In the present study, this possibility was actually tested by exposing OFF cells to fetal bovine serum (FBS), PDGF-BB and IGF-I. Data show that only FBS could induce a synthetic phenotype in OFF cells, while both PDGF-BB and IGF-I failed to induce any VSM activation.
authors.affiliation: Laboratory of Molecular and Gene Therapy, Institute of Clinical Physiology, CNR, Area della Ricerca, Via Moruzzi 1, 56124 Pisa, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Poliseno
authors.forename: Antonella
authors.initials: A
authors.lastname: Cecchettini
authors.forename: Laura
authors.initials: L
authors.lastname: Mariani
authors.forename: Monica
authors.initials: M
authors.lastname: Evangelista
authors.forename: Fernanda
authors.initials: F
authors.lastname: Ricci
authors.forename: Franco
authors.initials: F
authors.lastname: Giorgi
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Citti
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Rainaldi
mesh_terms: D000818:Animals; D000077214:Becaplermin; D002454:Cell Differentiation; D002478:Cells, Cultured; D016895:Culture Media, Serum-Free / Q000378:metabolism; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D007334:Insulin-Like Growth Factor I / Q000378:metabolism / Q000494:pharmacology; D008954:Models, Biological; D009119:Muscle Contraction; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism*; D032389:Myocytes, Smooth Muscle / Q000378:metabolism*; D010641:Phenotype; D010982:Platelet-Derived Growth Factor / Q000378:metabolism / Q000494:pharmacology; D020574:Proto-Oncogene Proteins c-sis; D034421:Sus scrofa; D013997:Time Factors
chemical_list: D016895:Culture Media, Serum-Free; D010982:Platelet-Derived Growth Factor; D020574:Proto-Oncogene Proteins c-sis; D000077214:Becaplermin; D007334:Insulin-Like Growth Factor I