Role of 15-hydroxyeicosatetraenoic acid in phosphorylation of ERK1/2 and caldesmon in pulmonary arterial smooth muscle cells.
We have reported that 15-hydroxyeicosatetraenoic acid (15-HETE) induces pulmonary artery (PA) contraction in rats exposed to hypoxia by activating extracellular signal-regulated kinase 1/2 (ERK1/2). In this study, we investigated the characteristics of 15-HETE mediating phosphorylation of ERK1/2 and caldesmon in rat pulmonary arterial smooth muscle cells (PASMCs). Our data showed that 15-HETE upregulated ERK1/2 phosphorylation in a dose-dependent manner, which could be blocked by ERK pathway inhibitors U0126 and PD98059. ERK1/2 phosphorylation was attenuated by inhibiting endogenous 15-HETE formation with lipoxygenase inhibitor, cinnamyl 3,4-dihydroxy-[alpha]-cyanocinnamate (CDC), in both normoxic and hypoxic PASMCs. ERK1/2 phosphorylation in response to 15-HETE was detected in cytosol as well as in nucleus and phosphorylatd ERK1/2 partly translocated into nucleus, which could be blocked by PD98059. In addition, caldesmon was phosphorylated in 15-HETE-stimulated cells; this could be inhibited by PD98059. These data demonstrated that 15-HETE is associated with ERK1/2 activation and caldesmon phosphorylation in PASMCs and that 15-HETE is at least partly involved in mediating activation of hypoxia-initiated ERK pathway, possibly leading to hypoxic pulmonary vasoconstriction.
Lu
Changlian
C
College of Pharmacy, Harbin Medical University, Daling Zhu Key Laboratory of Biopharmaceutical Engineering of Heilongjiang Province, Harbin, Heilongjiang 150081, P.R. China.
Liu
Ye
Y
Tang
Xiaobo
X
Ye
Hong
H
Zhu
Daling
D
D000818:Animals; D015153:Blotting, Western; D002148:Calmodulin-Binding Proteins / Q000378:metabolism*; D002467:Cell Nucleus / Q000201:enzymology / Q000378:metabolism; D003600:Cytosol / Q000201:enzymology / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D006893:Hydroxyeicosatetraenoic Acids / Q000502:physiology*; D000860:Hypoxia / Q000378:metabolism; D007150:Immunohistochemistry; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D010766:Phosphorylation; D011651:Pulmonary Artery / Q000166:cytology / Q000201:enzymology / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013268:Stimulation, Chemical; D013347:Subcellular Fractions / Q000201:enzymology / Q000378:metabolism
D002148:Calmodulin-Binding Proteins; D004791:Enzyme Inhibitors; D005419:Flavonoids; D006893:Hydroxyeicosatetraenoic Acids; C025984:15-hydroxy-5,8,11,13-eicosatetraenoic acid; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one