Role of redox signaling and poly (adenosine diphosphate-ribose) polymerase activation in vascular smooth muscle cell growth inhibition by nitric oxide and peroxynitrite

• Published in: Journal of vascular surgery 2008-03, Vol.47 (3), p.599-607
• Main Authors: Huang, James, MD, Lin, Stephanie C., MD, Nadershahi, Afshin, BS, Watts, Stephanie W., PhD, Sarkar, Rajabrata, MD, PhD
• Format: Article
• Language: English
• Subjects: Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Animals; Antioxidants - pharmacology; Apoptosis; Biological and medical sciences; Cell Proliferation - drug effects; Cell Survival; Cells, Cultured; Cyclic GMP - metabolism; DNA Replication; Dose-Response Relationship, Drug; Emergency and intensive care: renal failure. Dialysis management; Enzyme Activation; Enzyme Inhibitors - pharmacology; Intensive care medicine; Medical sciences; Muscle, Smooth, Vascular - drug effects; Muscle, Smooth, Vascular - enzymology; Muscle, Smooth, Vascular - metabolism; Muscle, Smooth, Vascular - pathology; Myocytes, Smooth Muscle - drug effects; Myocytes, Smooth Muscle - enzymology; Myocytes, Smooth Muscle - metabolism; Myocytes, Smooth Muscle - pathology; Nitric Oxide - metabolism; Nitric Oxide Donors - pharmacology; Oxidation-Reduction; Peroxynitrous Acid - metabolism; Poly(ADP-ribose) Polymerase Inhibitors; Poly(ADP-ribose) Polymerases - metabolism; Rats; Signal Transduction - drug effects; Superoxides - metabolism; Surgery; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Time Factors; Tyrosine - analogs & derivatives; Tyrosine - metabolism; Vascular surgery: aorta, extremities, vena cava. Surgery of the lymphatic vessels; Vasodilation
• ISSN: 0741-5214; 1097-6809
• DOI: 10.1016/j.jvs.2007.11.006

Purpose The vascular mediator, nitric oxide regulates vascular smooth muscle cell proliferation and can react with superoxide to form peroxynitrite, a highly reactive free radical. The intracellular mechanisms by which nitric oxide and peroxynitrite inhibit smooth muscle cell growth remain undefined, as is the potential role of peroxynitrite formation in the antiproliferative effects of nitric oxide. We sought to define the intracellular effects and signaling mechanisms of nitric oxide and peroxynitrite in smooth muscle cells. Methods Cultured rat aortic smooth muscle cells were treated with exogenous nitric oxide or peroxynitrite and inhibitors of nitric oxide and redox signaling pathways. Cell growth, DNA synthesis, apoptosis, cyclic guanosine 3′-5′ monophosphate (cGMP) levels, poly(adenosine diphosphate [ADP]-ribose) polymerase (PARP) activity, and cytotoxicity were assayed. Peroxynitrite formation was determined by nitrotyrosine immunoblotting. Vasoreactivity was assessed in isolated rat aortic rings after treatment with nitric oxide/peroxynitrite and redox agents. Results Both exogenous nitric oxide and peroxynitrite decreased cell growth and DNA synthesis of cultured rat aortic smooth muscle cells, but peroxynitrite-induced growth arrest was irreversible and associated with apoptosis and cytotoxicity. Inhibition of guanylate cyclase, PARP activity, mitogen-activated protein kinase, or bypass of ornithine decarboxylase did not reverse growth arrest by nitric oxide. The antioxidants N-acetylcysteine, ascorbate, and glutathione selectively reversed growth inhibition by nitric oxide but not by peroxynitrite. Antioxidants did not impair nitric oxide–induced cGMP generation in smooth muscle cells or nitric oxide–induced vasodilatation of isolated aortic rings. Nitric oxide treatment did not result in peroxynitrite formation and augmentation of superoxide levels did not induce peroxynitrite-like effects. Peroxynitrite-induced cytotoxicity and apoptosis were not reversed by antioxidants or PARP inhibition, because peroxynitrite activated PARP in J774 macrophages but failed to activate PARP in smooth muscle cells. Conclusions Exogenous nitric oxide induces reversible cytostasis in smooth muscle cells by a redox-sensitive mechanism independent of peroxynitrite formation and distinct from the nitric oxide vasodilating mechanism. Peroxynitrite does not activate PARP selectively in smooth muscle cells and induces redox-independent smooth muscle cell cytotoxicity