Vascular smooth muscle (VSM) growth is integral in the pathophysiology of blood vessel diseases, and identifying approaches that have capacity to regulate VSM growth is critically essential. Cyclic nucleotide signaling has been generally considered protective in cardiac and vascular tissues and has been the target of numerous basic science and clinical studies. In this project, the influence of BAY 41-2272 (BAY), a recently described soluble guanylate cyclase stimulator and inducer of cyclic guanosine monophosphate (cGMP) synthesis, on VSM cell growth was analyzed. In rat A7R5 VSM cells, BAY significantly reduced proliferation in a dose- and time-dependent fashion. BAY activated cGMP and cyclic adenosine monophosphate (cAMP) signaling evidenced through elevated cGMP and cAMP content, increased expression of cyclic nucleotide-dependent protein kinases, and differential vasodilator-stimulated phosphoprotein phosphorylation. BAY significantly elevated cyclin E expression, decreased expression of the regulatory cyclin-dependent kinases -2 and -6, increased expression of cell cycle inhibitory p21WAF1/Cip1 and p27Kip1, and reduced expression of phosphorylated focal adhesion kinase. These comprehensive findings provide first evidence for the antigrowth cell cycle-regulatory properties of the neoteric agent, BAY 41-2272, in VSM and lend support for its continued study in the clinical and basic cardiovascular sciences.
From the *Cardiovascular Disease Research Program, J.L. Chambers Biomedical/Biotechnology Research Institute and †Department of Biology, North Carolina Central University, Durham, NC; and ‡Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC.
Received for publication October 21, 2008; accepted November 26, 2008.
Supported by a grant from the American Heart Association and by National Institutes of Health and National Heart, Lung, and Blood Institute grants, HL59868 and HL81720.
The authors do not have any conflicts of interest to declare.
Reprints: David A. Tulis, PhD, FAHA, Department of Physiology, Brody School of Medicine, East Carolina University, 600 Moye Boulevard, 6E-108, Greenville, NC 27834 (e-mail: firstname.lastname@example.org).