c-Jun N-terminal kinase contributes to norepinephrine-induced contraction through phosphorylation of caldesmon in rat aortic smooth muscle.
Vascular smooth muscle contraction is mediated by activation of extracellular signal-regulated kinase (ERK) 1/2, an isoform of mitogen-activated protein kinase (MAPK). However, the role of stress-activated protein kinase/c-Jun N-terminal kinase (JNK) in vascular smooth muscle contraction has not been defined. We investigated the role of JNK in the contractile response to norepinephrine (NE) in rat aortic smooth muscle. NE evoked contraction in a dose-dependent manner, and this effect was inhibited by the JNK inhibitor SP600125. NE increased the phosphorylation of JNK, which was greater in aortic smooth muscle from hypertensive rats than from normotensive rats. NE-induced JNK phosphorylation was significantly inhibited by SP600125 and the conventional-type PKC (cPKC) inhibitor Gö6976, but not by the Rho kinase inhibitor Y27632 or the phosphatidylinositol 3-kinase inhibitor LY294002. Thymeleatoxin, a selective activator of cPKC, increased JNK phosphorylation, which was inhibited by Gö6976. SP600125 attenuated the phosphorylation of caldesmon, an actin-binding protein whose phosphorylation is increased by NE. These results show that JNK contributes to NE-mediated contraction through phosphorylation of caldesmon in rat aortic smooth muscle, and that this effect is regulated by the PKC pathway, especially cPKC.
Department of Physiology, College of Medicine, Institute of Biomedical Science and Technology, Konkuk University, Chungju, Choong-Buk, Korea.
Youn Ri
YR
Lee
Chang-Kwon
CK
Lee
Hyo-Jun
HJ
Park
Hyojin
H
Kim
Junghwan
J
Kim
Jaeheung
J
Kim
Keun Sang
KS
Lee
Yun Lyul
YL
Lee
Kyung Ok
KO
Min
Bokyung
B
Kim
D000818:Animals; D000873:Anthracenes / Q000494:pharmacology; D001013:Aorta, Thoracic / Q000166:cytology; D002148:Calmodulin-Binding Proteins / Q000378:metabolism*; D003900:Desoxycorticosterone / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006973:Hypertension / Q000139:chemically induced / Q000201:enzymology / Q000503:physiopathology; D066298:In Vitro Techniques; D007537:Isometric Contraction / Q000187:drug effects*; D048031:JNK Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D009638:Norepinephrine / Q000494:pharmacology*; D010703:Phorbol Esters / Q000494:pharmacology; D010766:Phosphorylation / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
D000873:Anthracenes; D002148:Calmodulin-Binding Proteins; D004791:Enzyme Inhibitors; D010703:Phorbol Esters; C432165:pyrazolanthrone; D003900:Desoxycorticosterone; C080287:thymeleatoxin; D048031:JNK Mitogen-Activated Protein Kinases; D009638:Norepinephrine