Nicotine induces mitogen-activated protein kinase dependent vascular smooth muscle cell migration.
Cigarette smoke, specifically the nicotine contained within, has been shown to cause ultrastructural changes in vascular endothelium resulting in the development of atherosclerosis. Our study examines the effects of nicotine on vascular smooth muscle cell (VSMC) migration and attempts to eludicidate the cellular mechanisms governing those effects. Bovine aortic VSMC were cultured in 10% fetal bovine serum (FBS) growth media and exposed to 10(-8) nicotine for varying periods of time. Boyden chamber chemotaxis assays and a scrape injury model using confluent cells were used to assess cell motility. Activation of the mitogen-activated protein kinases (MAPK), p38 and p44/42, was assessed using Western blotting methods. Nicotine, itself, did not cause significant VSMC migration. However, augmented migration was seen in nicotine-treated VSMCs (16.6+/-3-fold) and media (17.0+/-4-fold) with 10% FBS as chemoattractant. Inhibitors of p38 and p44/42 diminished this migration by 48.5+/-6% and 29.4+/-2%, respectively. Immunoblotting verified p38 and p44/42 activation with nicotine and inhibition with inhibitors of p38 and p44/42. Nicotine-treated endothelial cell (EC) conditioned media (CM) was shown to increase migration 20.3+/-l.l-fold. This chemotactic effect was diminished both with heat treatment and serial dilution. In conclusion, nicotine enhances the chemoatactiveness of VSMC. This migration is mediated via the MAPKs p38 and p44/42. Nicotine causes EC production of a chemoattractant molecule that enhances VSMC migration.
Di Luozzo
Gabriele
G
Section of Vascular Surgery, Department of Surgery, Yale University School of Medicine and Veterans' Administration, 333 Cedar Street FMB-137, New Haven, CT 06520, USA.
Pradhan
Sanjeev
S
Dhadwal
Ajay K
AK
Chen
Alan
A
Ueno
Hirokazu
H
Sumpio
Bauer E
BE
D000818:Animals; D001161:Arteriosclerosis / Q000503:physiopathology*; D015153:Blotting, Western; D002417:Cattle; D002465:Cell Movement / Q000187:drug effects*; D002630:Chemotactic Factors / Q000494:pharmacology; D005731:Ganglionic Stimulants / Q000494:pharmacology*; D009131:Muscle, Smooth, Vascular / Q000166:cytology* / Q000502:physiology*; D009538:Nicotine / Q000494:pharmacology*; D012907:Smoking / Q000009:adverse effects*; D048051:p38 Mitogen-Activated Protein Kinases / Q000494:pharmacology*
D002630:Chemotactic Factors; D005731:Ganglionic Stimulants; D009538:Nicotine; D048051:p38 Mitogen-Activated Protein Kinases