title: Caveolin-3 Promotes a Vascular Smooth Muscle Contractile Phenotype.
abstract: Epidemiological studies have demonstrated the importance of cardiovascular diseases in Western countries. Among the cell types associated with a dysfunctional vasculature, smooth muscle (SM) cells are believed to play an essential role in the development of these illnesses. Vascular SM cells are key regulators of the vascular tone and also have an important function in the development of atherosclerosis and restenosis. While in the normal vasculature, contractile SM cells are predominant, in atherosclerotic vascular lesions, synthetic cells migrate toward the neointima, proliferate, and synthetize extracellular matrix proteins. In the present study, we have examined the role of caveolin-3 in the regulation of SM cell phenotype. Caveolin-3 is expressed in vivo in normal arterial SM cells, but its expression appears to be lost in cultured SM cells. Our data show that caveolin-3 expression in the A7r5 SM cell line is associated with increased expression of contractility markers such as SM α-actin, SM myosin heavy chain but decreased expression of the synthetic phenotype markers such as p-Elk and Klf4. Moreover, we also show that caveolin-3 expression can reduce proliferation upon treatment with LDL or PDGF. Finally, we show that caveolin-3-expressing SM cells are less sensitive to apoptosis than control cells upon treatment with oxidized LDL. Taken together, our data suggest that caveolin-3 can regulate the phenotypic switch between contractile and synthetic SM cells. A better understanding of the factors regulating caveolin-3 expression and function in this cell type will permit the development of a better comprehension of the factors regulating SM function in atherosclerosis and restenosis.
authors.affiliation: Faculté de Médecine, INSERM UMR1069 "Nutrition, Croissance et Cancer", Université François Rabelais de Tours , Tours , France ; Department of Stem Cell Biology and Regenerative Medicine, Kimmel Cancer Center, Thomas Jefferson University , Philadelphia, PA , USA ; Department of Cancer Biology, Kimmel Cancer Center, Thomas Jefferson University , Philadelphia, PA , USA.
authors.forename: Jorge L
authors.initials: JL
authors.lastname: Gutierrez-Pajares
authors.affiliation: Department of Stem Cell Biology and Regenerative Medicine, Kimmel Cancer Center, Thomas Jefferson University , Philadelphia, PA , USA ; Department of Cancer Biology, Kimmel Cancer Center, Thomas Jefferson University , Philadelphia, PA , USA.
authors.forename: Jeannette
authors.initials: J
authors.lastname: Iturrieta
authors.affiliation: Department of Stem Cell Biology and Regenerative Medicine, Kimmel Cancer Center, Thomas Jefferson University , Philadelphia, PA , USA ; Department of Cancer Biology, Kimmel Cancer Center, Thomas Jefferson University , Philadelphia, PA , USA.
authors.forename: Vipin
authors.initials: V
authors.lastname: Dulam
authors.affiliation: Department of Stem Cell Biology and Regenerative Medicine, Kimmel Cancer Center, Thomas Jefferson University , Philadelphia, PA , USA ; Department of Cancer Biology, Kimmel Cancer Center, Thomas Jefferson University , Philadelphia, PA , USA.
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.affiliation: The Manchester Centre for Cellular Metabolism (MCCM), Institute of Cancer Sciences, University of Manchester , Manchester , UK ; The Breakthrough Breast Cancer Research Unit, Institute of Cancer Sciences, University of Manchester , Manchester , UK.
authors.forename: Stephanos
authors.initials: S
authors.lastname: Pavlides
authors.affiliation: Department of Stem Cell Biology and Regenerative Medicine, Kimmel Cancer Center, Thomas Jefferson University , Philadelphia, PA , USA ; Department of Cancer Biology, Kimmel Cancer Center, Thomas Jefferson University , Philadelphia, PA , USA.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Malacari
authors.affiliation: The Manchester Centre for Cellular Metabolism (MCCM), Institute of Cancer Sciences, University of Manchester , Manchester , UK ; The Breakthrough Breast Cancer Research Unit, Institute of Cancer Sciences, University of Manchester , Manchester , UK.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Lisanti
authors.affiliation: Faculté de Médecine, INSERM UMR1069 "Nutrition, Croissance et Cancer", Université François Rabelais de Tours , Tours , France ; Department of Stem Cell Biology and Regenerative Medicine, Kimmel Cancer Center, Thomas Jefferson University , Philadelphia, PA , USA ; Department of Cancer Biology, Kimmel Cancer Center, Thomas Jefferson University , Philadelphia, PA , USA ; Department of Biochemistry and Molecular Biology, Thomas Jefferson University , Philadelphia, PA , USA.
authors.forename: Philippe G
authors.initials: PG
authors.lastname: Frank
keywords: caveolae; caveolin-3; lipoproteins; smooth muscle; vascular diseases