|
|
||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Department of Surgery, Dartmouth Medical School, Lebanon, NH, USA; Department of Pharmacology and Toxicology, Dartmouth Medical School, Lebanon, NH, USA
2 Department of Surgery, Dartmouth Medical School, Lebanon, NH, USA
3 Department of Cell Biology, Harvard Medical School, Boston, MA, USA
* To whom correspondence should be addressed. E-mail: Kathleen.A.Martin{at}Dartmouth.edu.
Vascular smooth muscle cells (VSMC) in mature, normal blood vessels exhibit a differentiated, quiescent, contractile morphology, but injury induces a phenotypic modulation toward a proliferative, de-differentiated, migratory phenotype with upregulated extracellular matrix protein synthesis (synthetic phenotype) which contributes to intimal hyperplasia. The mTOR pathway inhibitor rapamycin inhibits intimal hyperplasia in animal models and in human clinical trials. We report that rapamycin treatment induces differentiation in cultured synthetic phenotype VSMC from multiple species. VSMC treated with rapamycin assumed a contractile morphology, quantitatively reflected by a 67% decrease in cell area. Total protein and collagen synthesis were also inhibited by rapamycin. Rapamycin induced expression of the VSMC differentiation marker contractile proteins SM
-actin, calponin, and SM myosin heavy chain (SM-MHC), as observed by immunoblotting and immunohistochemistry. Notably, we detected a striking rapamycin induction of calponin and SM-MHC mRNA, suggesting a role for mTOR in transcriptional control of VSMC gene expression. Rapamycin also induced expression of the cyclin dependent kinase inhibitors p21cip and p27kip, consistent with cell cycle withdrawal. Rapamycin inhibits mTOR, a signaling protein that regulates protein synthesis effectors, including p70 S6K1. Overexpression of p70 S6K1 inhibited rapamycin-induced contractile protein and p21cip expression, suggesting that this kinase opposes VSMC differentiation. In conclusion, we report that regulation of VSMC differentiation is a novel function of the rapamycin-sensitive mTOR signaling pathway.
This article has been cited by other articles:
![]() |
W. Jiang, Z. Zhu, and H. J. Thompson Dietary Energy Restriction Modulates the Activity of AMP-Activated Protein Kinase, Akt, and Mammalian Target of Rapamycin in Mammary Carcinomas, Mammary Gland, and Liver Cancer Res., July 1, 2008; 68(13): 5492 - 5499. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. M. Rice, D. H. Desai, D. L. Preston, P. S. Wehner, and E. R. Blough Vascular: Uniaxial stretch-induced regulation of mitogen-activated protein kinase, Akt and p70 S6 kinase in the ageing Fischer 344 x Brown Norway rat aorta Exp Physiol, September 1, 2007; 92(5): 963 - 970. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Albinsson and P. Hellstrand Integration of signal pathways for stretch-dependent growth and differentiation in vascular smooth muscle Am J Physiol Cell Physiol, August 1, 2007; 293(2): C772 - C782. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. K. Bowles, K. K. Maddali, V. C. Dhulipala, and D. H. Korzick PKC{delta} mediates anti-proliferative, pro-apoptic effects of testosterone on coronary smooth muscle Am J Physiol Cell Physiol, August 1, 2007; 293(2): C805 - C813. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. L. Ma, X. Z. Ruan, S. H. Powis, J. F. Moorhead, and Z. Varghese Anti-atherosclerotic effects of sirolimus on human vascular smooth muscle cells Am J Physiol Heart Circ Physiol, June 1, 2007; 292(6): H2721 - H2728. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Verheye, W. Martinet, M. M. Kockx, M. W.M. Knaapen, K. Salu, J.-P. Timmermans, J. T. Ellis, D. L. Kilpatrick, and G. R.Y. De Meyer Selective Clearance of Macrophages in Atherosclerotic Plaques by Autophagy J. Am. Coll. Cardiol., February 13, 2007; 49(6): 706 - 715. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. R. Lock, S. H. Sacks, and M. G. Robson Rapamycin at subimmunosuppressive levels inhibits mesangial cell proliferation and extracellular matrix production Am J Physiol Renal Physiol, January 1, 2007; 292(1): F76 - F81. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. Grantcharova, H. P. Reusch, S. Grossmann, J. Eichhorst, H.-W. Krell, M. Beyermann, W. Rosenthal, and A. Oksche N-Terminal Proteolysis of the Endothelin B Receptor Abolishes Its Ability to Induce EGF Receptor Transactivation and Contractile Protein Expression in Vascular Smooth Muscle Cells Arterioscler. Thromb. Vasc. Biol., June 1, 2006; 26(6): 1288 - 1296. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. M. Fetalvero, M. Shyu, A. P. Nomikos, Y.-F. Chiu, R. J. Wagner, R. J. Powell, J. Hwa, and K. A. Martin The prostacyclin receptor induces human vascular smooth muscle cell differentiation via the protein kinase A pathway Am J Physiol Heart Circ Physiol, April 1, 2006; 290(4): H1337 - H1346. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Rosner, N. McCarthy, and M. Bennett Rapamycin inhibits human in stent restenosis vascular smooth muscle cells independently of pRB phosphorylation and p53 Cardiovasc Res, June 1, 2005; 66(3): 601 - 610. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. H. Damon Sympathetic innervation promotes vascular smooth muscle differentiation Am J Physiol Heart Circ Physiol, June 1, 2005; 288(6): H2785 - H2791. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Sakakibara, B. Liu, S. Hollenbeck, and K. C. Kent Rapamycin inhibits fibronectin-induced migration of the human arterial smooth muscle line (E47) through the mammalian target of rapamycin Am J Physiol Heart Circ Physiol, June 1, 2005; 288(6): H2861 - H2868. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. A. Costa and D. I. Simon Molecular Basis of Restenosis and Drug-Eluting Stents Circulation, May 3, 2005; 111(17): 2257 - 2273. [Full Text] [PDF] |
||||
![]() |
D. Bi, J. Nishimura, N. Niiro, K. Hirano, and H. Kanaide Contractile Properties of the Cultured Vascular Smooth Muscle Cells: The Crucial Role Played by RhoA in the Regulation of Contractility Circ. Res., April 29, 2005; 96(8): 890 - 897. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. A. Lucchesi Rapamycin plays a new role as differentiator of vascular smooth muscle phenotype. Focus on "The mTOR/p70 S6K1 pathway regulates vascular smooth muscle differentiation" Am J Physiol Cell Physiol, March 1, 2004; 286(3): C480 - C481. [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |