Nicotine induces platelet-derived growth factor release and cytoskeletal alteration in aortic smooth muscle cells

Background: Cigarette smoking is implicated in atherosclerotic plaque formation, but the role of nicotine in this process is not completely understood. The release of platelet-derived growth factor (PDGF) by the bovine aortic smooth muscle cell (SMC) after nicotine administration at a concentration similar to that ingested by active and passive smokers and the role of PDGF in SMC cytoskeletal modification were studied. Methods: SMC, harvested with enzymatic digestion from calf aorta, were stimulated in a serum-free medium for 72 hours with (-)-nicotine (from 6 × 10-4 mol/L to 6 × 10-8 mol/L). The release of PDGF was assessed by inhibition antibody-binding assay and confirmed by Western blotting. Mitogenic activity of nicotine on SMCs was also determined. The SMC cytoskeleton was studied with specific antibodies anti-α-actin fibers, anti-vimentin, and anti-β-tubulin, and the modification induced by PDGF was assessed by blocking PDGF activity with specific antibodies. Results: The greatest PDGF release (1.24 ± 0.14 ng/104 cells vs control 0.43 ± 0.07 ng/104 cells) was noted at a (-)-nicotine concentration of 6 × 10-7 mol/L (P