The effect of protein kinase C and its alpha subtype on human vascular smooth muscle cell proliferation, migration and fibronectin production.
BACKGROUND
Vascular smooth muscle cell (SMC) migration, proliferation and extracellular matrix protein production are key steps in the formation of intimal hyperplasia, a process that leads to failure of vascular reconstructions. Protein kinase C (PKC) may be involved in all 3 cellular events. PKC consists of a family of 11 isotypes, 8 of which we have identified in human vascular SMCs. In this study we evaluate the role of PKCalpha as a second messenger for proliferation, migration and fibronectin production induced by human saphenous vein SMCs.


METHODS
DNA synthesis was evaluated by using (3)H-thymidine incorporation. Mitogen-activated protein kinase (MAP-K) activation was quantified by Western blotting with an antibody to its phosphorylated substrate, Elk-1. Chemotaxis was evaluated by using a microchemotaxis chamber. SMC fibronectin was measured by Western blotting. For all experiments, PKCalpha was blocked with a selective inhibitor, Gö6976.


RESULTS
Gö6976, at concentrations that allow selective inhibition of PKCalpha, inhibited platelet-derived growth factor-stimulated SMC proliferation and MAP-K activation by 30% to 40% and 30% to 60%, respectively. SMC chemotaxis was stimulated approximately 2-fold by the PKCalpha inhibitor. Neither basal nor transforming growth factor-betaI induced fibronectin production was affected by Gö6976.


CONCLUSIONS
Our data suggest that PKCalpha is a positive mediator of SMC proliferation and MAP-K activity, a negative regulator of migration and has no effect on SMC fibronectin production. These data suggest that modulating activities of specific PKC isotypes might be useful in both the study and control of intimal hyperplasia.
Division of Vascular Surgery, Department of Surgery, New York Presbyterian Hospital/Cornell Campus, Weill Medical College of Cornell University, New York, NY 10021, USA.
J
J
Okazaki
K
K
Mawatari
B
B
Liu
K C
KC
Kent
D002227:Carbazoles / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D002633:Chemotaxis / Q000187:drug effects / Q000502:physiology*; D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005353:Fibronectins / Q000096:biosynthesis*; D006801:Humans; D007211:Indoles / Q000494:pharmacology; D007527:Isoenzymes / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism*; D051571:Protein Kinase C-alpha; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism; D012501:Saphenous Vein / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D015290:Second Messenger Systems; D014157:Transcription Factors; D016212:Transforming Growth Factor beta / Q000494:pharmacology; D050807:ets-Domain Protein Elk-1
D002227:Carbazoles; D004268:DNA-Binding Proteins; C494112:ELK1 protein, human; D004791:Enzyme Inhibitors; D005353:Fibronectins; D007211:Indoles; D007527:Isoenzymes; D011518:Proto-Oncogene Proteins; D014157:Transcription Factors; D016212:Transforming Growth Factor beta; D050807:ets-Domain Protein Elk-1; C081021:Go 6976; D020794:Receptor Protein-Tyrosine Kinases; C496628:PRKCA protein, human; D011493:Protein Kinase C; D051571:Protein Kinase C-alpha; D020928:Mitogen-Activated Protein Kinases