Regulation of Vascular Smooth Muscle Migration by Mitogen-activated Protein Kinase and Calcium/Calmodulin-dependent Protein Kinase II Signaling Pathways

• Published in: Journal of molecular and cellular cardiology Vol. 30; no. 11; pp. 2377 - 2389
• Main Authors: Lundberg, Martha S., Curto, Karen A., Bilato, Claudio, Monticone, Robert E., Crow, Michael T.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.11.1998
• Subjects: 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine - analogs & derivatives; 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine - pharmacology; Animals; Calcium-Calmodulin-Dependent Protein Kinases - antagonists & inhibitors; Calcium-Calmodulin-Dependent Protein Kinases - physiology; Calcium/calmodulin-dependent protein kinase II; Cell migration; Cell Movement - drug effects; Cell Movement - physiology; Cells, Cultured; Enzyme Activation - drug effects; Enzyme Inhibitors - pharmacology; Flavonoids - pharmacology; integrins; MAPK; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Mitogen-Activated Protein Kinases; Muscle, Smooth, Vascular - cytology; Muscle, Smooth, Vascular - physiology; Phosphoprotein Phosphatases - antagonists & inhibitors; Phosphoprotein Phosphatases - physiology; Platelet-derived growth factor; Platelet-Derived Growth Factor - pharmacology; Rats; Rats, Wistar; Signal Transduction - drug effects; Signal Transduction - physiology; Vascular smooth muscle cells; integrins; Platelet-derived growth factor; MAPK; Calcium/calmodulin-dependent protein kinase II; Vascular smooth muscle cells; Cell migration
• DOI: 10.1006/jmcc.1998.0795
• ISSN: 0022-2828

Platelet-derived growth factor BB (PDGF BB) activation of the mitogen-activated protein kinases (MAPK), ERK1 and ERK2, has been shown to be necessary for mitogen-stimulated proliferation, but its role in regulating cell migration and its relationship to other chemotactic signaling events, such as CamKII activation, has not been defined. Using a modified Boyden chamber apparatus, we tested the effects of a selective inhibitor of the upstream activator of ERK1/2, MEK1, on PDGF-stimulated rat aortic vascular smooth muscle cells (VSMCs) alone and in combination with KN62, a selective inhibitor of CamKII. The MEK1 inhibitor, PD98059, caused a dose-dependent reduction in ERK2 activity that paralleled a decrease in migration up to 60%. This inhibition of migration was similar to that seen with KN62 and the combined effects of both inhibitors were non-additive. Although KN62 did not affect ERK2 activity in response to PDGF, PD98059 markedly inhibited PDGF-stimulated CamKII activity, suggesting that activation of CamKII by PDGF was dependent on ERK activity and that the effects of ERK inhibition on migration may be mediated through its ability to inhibit CamKII activity. To directly test this, VSMCs were infected with a recombinant adenovirus expressing constitutively activated CamKII. Infection reversed the inhibitory effects of KN62 on migration, but had no effect on the inhibition of migration seen with PD98059. These results suggest that while MAPK may act upstream of CamKII to control its activation in response to PDGF, it also regulates migration independently of CamKII activation.