Role of the G-protein and tyrosine kinase--Rho/ROK pathways in 15-hydroxyeicosatetraenoic acid induced pulmonary vasoconstriction in hypoxic rats.
It has been previously reported by us that hypoxia activates lung 15-lipoxygenase (15-LO), which catalyzes arachidonic acid to 15-hydroxyeicosatetraenoic acid (15-HETE), leading to the constriction of pulmonary artery (PA). Rho-associated serine/threonine kinase (ROK), a downstream effector of small GTPase RhoA that may be modulated by G-protein and tyrosine kinase, plays an important role in smooth muscle contraction. However, whether the 15-HETE induced PA vasoconstriction involves the Rho/ROK pathway remains to be demonstrated. Therefore, we studied the contribution of ROK as well as G-protein and tyrosine kinase to the 15-HETE induced pulmonary vasoconstriction using PA ring technique, RNA interference technology, RP-HPLC, western blot and RT-PCR combined with the blockers. The hypoxia-induced expression of ROK is regulated by 15-HETE in rat PA smooth muscle cells (PASMCs), leading to vasoconstriction. The up-regulation of ROK expression caused by 15-HETE appears to be mediated by the G-protein and tyrosine kinase pathways. The translocation of ROK2 from the nucleus to the cytoplasm during hypoxia exposure relies on the mechanism for 15-HETE production. These results suggest that 15-HETE may mediate the up-regulation of ROK expression through G-protein and tyrosine kinase pathways under hypoxic condition, leading to PA vasoconstriction.
Department of Biopharmaceutical Sciences; Department of Pharmacology, College of Pharmacy, Harbin Medical University; and Biopharmaceutical Key Laboratory of Heilongjiang Province, Harbin 150081, People's Republic of China.
Yali
Y
Wang
Di
D
Liang
Shuang
S
Wang
Zhaoping
Z
Qiu
Xiaojie
X
Chu
Shuo
S
Chen
Lisha
L
Li
Xiaowei
X
Nie
Rong
R
Zhang
Zhigang
Z
Wang
Daling
D
Zhu
D000818:Animals; D006893:Hydroxyeicosatetraenoic Acids / Q000494:pharmacology*; D000860:Hypoxia / Q000378:metabolism*; D008297:Male; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011651:Pulmonary Artery / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D014661:Vasoconstriction / Q000187:drug effects*; D054460:rho-Associated Kinases / Q000235:genetics / Q000378:metabolism*; D020742:rhoA GTP-Binding Protein / Q000378:metabolism*
D006893:Hydroxyeicosatetraenoic Acids; C025984:15-hydroxy-5,8,11,13-eicosatetraenoic acid; D011505:Protein-Tyrosine Kinases; D054460:rho-Associated Kinases; D020742:rhoA GTP-Binding Protein