Protein kinase C delta activated adhesion regulates vascular smooth muscle cell migration.
BACKGROUND
Vascular smooth muscle cell (VSMC) migration, fundamental in the pathophysiology of atherogenesis and restenosis, is a coordinated process governed by the formation and disassembly of focal adhesions. Previous studies have demonstrated that VSMC migration is regulated via a signaling network involving protein kinase C delta (PKCdelta). In these studies, we test the hypothesis that PKCdelta regulates VSMC migration through modulation of cell adhesion.


METHODS
Using primary VSMCs isolated from PKCdelta wild type (+/+) and knock-out (-/-) mice, the effects of PKCdelta on VSMC migration and adhesion were assessed by chemotaxis and cell adhesion.


RESULTS
In evaluating cell migration, we found a decrease in platelet-derived growth factor-BB (PDGF-BB; 5 ng/mL x 6 h) stimulated migration of PKCdelta-/-VSMCs as compared to PKCdelta+/+VSMCs, by 59.4 +/- 5.9% (P < 0.01). A similar reduction in migration of PKCdelta-/-VSMCs (66.5 +/- 5.7%, P < 0.01) was also observed on collagen-coated (COL) membranes. Next, we examined cell attachment, a critical step of migration. PKCdelta-/-VSMCs exhibited significantly reduced adherence by 50.3 +/- 1.8% (P < 0.01). A similar defect of PKCdelta-/-VSMCs was also observed on the COL surface, 30.7 +/- 2.3% (P < 0.01). Interestingly, PDGF-BB did not stimulate attachment of VSMCs of either genotype. Consistent with these results, Rottlerin (2 microM), a selective inhibitor of PKCdelta, blocked migration and attachment of VSMCs by 56.8 +/- 3.4% (P < 0.01) and 37.7 +/- 1.9% (P < 0.01), respectively.


CONCLUSIONS
Taken together, our data indicate that PKCdelta activation is necessary for VSMC adhesion, which could, at least in part, contribute to the regulatory function of this kinase in cell migration thus pathogenesis of vascular lesions.
Kamiya
Kentaro
K
Department of Surgery, Division of Vascular Surgery, Weill Medical College of Cornell University, New York, New York 10021, USA.
Ryer
Evan
E
Sakakibara
Kenji
K
Zohlman
Andrew
A
Kent
K Craig
KC
Liu
Bo
B
D000098:Acetophenones / Q000494:pharmacology; D000818:Animals; D050197:Atherosclerosis / Q000209:etiology / Q000503:physiopathology; D000077214:Becaplermin; D001578:Benzopyrans / Q000494:pharmacology; D002448:Cell Adhesion / Q000502:physiology; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D004791:Enzyme Inhibitors / Q000494:pharmacology; D017353:Gene Deletion; D005786:Gene Expression Regulation; D016023:Integrins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D009131:Muscle, Smooth, Vascular / Q000166:cytology* / Q000502:physiology*; D010982:Platelet-Derived Growth Factor / Q000378:metabolism; D051745:Protein Kinase C-delta / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*; D020574:Proto-Oncogene Proteins c-sis; D015398:Signal Transduction
D000098:Acetophenones; D001578:Benzopyrans; D004791:Enzyme Inhibitors; D016023:Integrins; D010982:Platelet-Derived Growth Factor; D020574:Proto-Oncogene Proteins c-sis; D000077214:Becaplermin; C085746:rottlerin; D051745:Protein Kinase C-delta