Nicotinic and PDGF-receptor function are essential for nicotine-stimulated mitogenesis in human vascular smooth muscle cells.
Cigarette smoking is implicated in the formation of occlusive vascular diseases. Nicotine's role in this process is incompletely understood. Nicotine's effect on human aortic vascular smooth muscle cells (HaVSMC) and the role of the nicotinic receptor (nAChR), platelet-derived growth factor (PDGF), and the PDGF-receptor (PDGF-R) in this response were studied. Nicotine's mitogenic effect was characterized by three methods: thymidine incorporation, a viability/proliferation assay based on metabolic conversion of tetrazolium salt to formazan dye and cell counting. Nicotine administration (10(-6) M) stimulated cell cycle entry marked by increased DNA synthesis, PCNA and cyclin D1 production, and increased cell division. Nicotinic receptor blockade with d-tubocurarine, a nicotinic AchR blocker, decreased nicotine-induced DNA synthesis, and cell division (0.33 +/- 0.04, 0.77 +/- 0.31-fold decrease, respectively). Nicotine increased cellular PDGF-BB transcript levels and protein release (ELISA: 1.6 +/- 0.5-fold increase) but not PDGF-AA or PDGF-AB release. Nicotine increased PDGFbeta-receptor protein content. PDGF inactivation with anti-PDGF antibody abolished nicotine-induced DNA synthesis (1.9 +/- 0.08-fold decrease). PDGF-R blockade with the PDGF-R antagonist tyrphostin AG 1295 decreased nicotine-induced DNA synthesis and cell division (0.25 +/- 0.01, 0.44 +/- 0.2-fold decrease, respectively). PDGF-R blockade reversed nicotine-stimulated increases in PDGF release, PDGF-BB transcripts, and PDGF-receptor levels (0.68 +/- 0.34; 0.46 +/- 0.01; 0.28 +/- 0.01-fold decrease, respectively). In conclusion, nicotine-mediated activation of nAChRs increases PDGF-BB transcription and protein production as well as PDGF beta-receptor levels. PDGF-BB/PDGF-R interaction is vital in nicotine's mitogenic actions on human aortic smooth muscle cells.
Pestana
Ivo A
IA
Department of Surgery, University of Miami School of Medicine, Miami, Florida 33136, USA.
Vazquez-Padron
Roberto I
RI
Aitouche
Abdelouahab
A
Pham
Si M
SM
D000328:Adult; D000368:Aged; D001011:Aorta / Q000187:drug effects / Q000378:metabolism; D000077214:Becaplermin; D015153:Blotting, Western; D002453:Cell Cycle; D002455:Cell Division; D002460:Cell Line; D049109:Cell Proliferation; D002470:Cell Survival; D002478:Cells, Cultured; D017077:Culture Media, Conditioned / Q000494:pharmacology; D019938:Cyclin D1 / Q000378:metabolism; D004247:DNA / Q000737:chemistry; D006801:Humans; D007202:Indicators and Reagents / Q000494:pharmacology; D008024:Ligands; D008297:Male; D008875:Middle Aged; D008934:Mitogens; D015233:Models, Statistical; D009131:Muscle, Smooth, Vascular / Q000166:cytology* / Q000378:metabolism*; D009538:Nicotine / Q000378:metabolism / Q000494:pharmacology*; D018733:Nicotinic Antagonists / Q000494:pharmacology; D009580:Nitroblue Tetrazolium / Q000494:pharmacology; D010982:Platelet-Derived Growth Factor / Q000378:metabolism; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D020574:Proto-Oncogene Proteins c-sis; D012333:RNA, Messenger / Q000378:metabolism; D011950:Receptors, Cholinergic / Q000378:metabolism; D011978:Receptors, Nicotinic / Q000378:metabolism*; D017479:Receptors, Platelet-Derived Growth Factor / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012907:Smoking; D013936:Thymidine / Q000378:metabolism; D013997:Time Factors; D014403:Tubocurarine / Q000494:pharmacology
D017077:Culture Media, Conditioned; D007202:Indicators and Reagents; D008024:Ligands; D008934:Mitogens; D018733:Nicotinic Antagonists; D010982:Platelet-Derived Growth Factor; D018809:Proliferating Cell Nuclear Antigen; D020574:Proto-Oncogene Proteins c-sis; D012333:RNA, Messenger; D011950:Receptors, Cholinergic; D011978:Receptors, Nicotinic; C075278:platelet-derived growth factor A; C095477:platelet-derived growth factor AB; D019938:Cyclin D1; D000077214:Becaplermin; D009580:Nitroblue Tetrazolium; D009538:Nicotine; D004247:DNA; D017479:Receptors, Platelet-Derived Growth Factor; D013936:Thymidine; D014403:Tubocurarine