NOS gene transfer inhibits expression of cell cycle regulatory molecules in vascular smooth muscle cells

• Published in: The American journal of physiology Vol. 276; no. 5; pp. H1450 - H1459
• Main Authors: Sharma, R V, Tan, E, Fang, S, Gurjar, M V, Bhalla, R C
• Format: Journal Article
• Language: English
• Published: United States 01-05-1999
• Subjects: Adenoviridae; Animals; Becaplermin; Cell Division - genetics; Cells, Cultured; Coronary Vessels - cytology; Coronary Vessels - enzymology; Cyclin A - metabolism; Cyclin E - metabolism; Cyclin-Dependent Kinase Inhibitor p21; Cyclins - metabolism; Gene Expression Regulation, Enzymologic - drug effects; Gene Expression Regulation, Viral - drug effects; Gene Transfer Techniques; Genes, Reporter; Guinea Pigs; Lac Operon; Muscle, Smooth, Vascular - cytology; Muscle, Smooth, Vascular - enzymology; Nitric Oxide Synthase - genetics; Nitric Oxide Synthase Type III; Phosphorylation; Platelet-Derived Growth Factor - metabolism; Proliferating Cell Nuclear Antigen - metabolism; Proto-Oncogene Proteins c-sis; Thymidine - metabolism; Thymidine - pharmacology; Tritium
• ISSN: 0002-9513
• DOI: 10.1152/ajpheart.1999.276.5.h1450

The mechanisms of nitric oxide (NO)-mediated inhibition of vascular smooth muscle (VSM) cell proliferation are still obscure. Cyclins A and E in association with cyclin-dependent kinase 2 (cdk2) serve as positive regulators for mammalian cell cycle progression through the G1/S checkpoint of the cell cycle and subsequent cell proliferation. Therefore, we have tested the effect of adenovirus-mediated transfection of the endothelial nitric oxide synthase (eNOS) gene into guinea pig coronary VSM cells on platelet-derived growth factor (BB homodimer) (PDGF-BB)-stimulated cell proliferation and the expression of cell cycle regulatory molecules. Transfection of the eNOS gene (eNOS) into VSM cells significantly inhibited (P < 0.05) [3H]thymidine incorporation into the DNA in response to PDGF-BB stimulation compared with lacZ-transfected control cells. The eNOS transfer significantly inhibited (P < 0.05) PDGF-BB-induced proliferating cell nuclear antigen (PCNA) and cyclin A expression in VSM cells compared with cells transfected with the control vector. The time course of cyclin E expression in response to PDGF-BB stimulation was delayed in eNOS-transfected cells. Levels of cyclin-dependent kinase inhibitors p21 and p27 were not significantly affected by eNOS transfer. eNOS transfer did not decrease PDGF-beta receptor number, affinity, and autophosphorylation measured by radioreceptor assay and Western analysis. These results suggest that inhibition of PDGF-stimulated expression of cyclin A, cyclin E, and PCNA is the target of NO action. These findings could explain, at least in part, NO-mediated inhibition of VSM cell proliferation.