Increased expression and altered subcellular distribution of PKC-δ and PKC-ɛ in pulmonary arteries exposed to hypoxia and 15-HETE.
15-hydroxyeicosatetraenoic acid (15-HETE), a product of arachidonic acid (AA) catalyzed by 15-lipoxygenase (15-LOX), is an important mediator of hypoxic pulmonary vasoconstriction (HPV). We have previously reported that 15-HETE-induced pulmonary vasoconstriction occurs via protein kinase C (PKC) pathway, however, the role of PKC isoforms involved in 15-HETE-induced pulmonary vasoconstriction remains poorly understood. To examine the potential role of PKC-δ and PKC-ɛ isoforms that appear to be involved in 15-HETE-induced pulmonary artery (PA) contraction, a combination of immunofluorescence, western blotting, semi-quantitative PCR and functional contractile tension approaches on rat PA rings were utilized. We found that 15-HETE activates the translocation of PKC-δ and PKC-ɛ from the cytoplasm to the membranes of pulmonary arterial smooth muscle cells (PASMCs). However, the alteration was significantly reversed by nordihydroguairetic acid (NDGA), a 15-LOX inhibitor which blocked the formation of endogenous 15-HETE. Both endogenous and exogenous 15-HETE enhanced the expression of PKC-δ and PKC-ɛ in PASMCs exposure to hypoxia. The PKC inhibitor Gö6983 and rottlerin (PKC-δ selective), and the inhibitor selective for PKC-ɛ peptide significantly attenuated constriction effect of 15-HETE on isolated PA rings of rats maintained for 9 days in hypoxic environments (FiO(2)=0.12) compared with siblings rats under normoxia. Thus, these findings indicate that PKC-δ and PKC-ɛ contributing to hypoxic pulmonary artery contraction elicited by 15-HETE.
Li
Xiaohong
X
Department of Anaesthesiology, The First Affiliated Hospital of Harbin Medical University, 23 Youzheng Street, Nangang District, Harbin, Heilongjiang 150001, PR China. lixiaohong19731973@yahoo.com.cn
Ma
Cui
C
Zhu
Daling
D
Meng
Liwei
L
Guo
Lei
L
Wang
Yali
Y
Zhang
Lei
L
Li
Zhixue
Z
Li
Enyou
E
D000818:Animals; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D003593:Cytoplasm / Q000187:drug effects / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D006893:Hydroxyeicosatetraenoic Acids / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D000860:Hypoxia / Q000201:enzymology / Q000378:metabolism*; D042541:Intracellular Space / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D008297:Male; D032389:Myocytes, Smooth Muscle / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D051745:Protein Kinase C-delta / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D051744:Protein Kinase C-epsilon / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D021381:Protein Transport / Q000187:drug effects; D011651:Pulmonary Artery / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D014661:Vasoconstriction / Q000187:drug effects
D006893:Hydroxyeicosatetraenoic Acids; D047428:Protein Kinase Inhibitors; D012333:RNA, Messenger; C025984:15-hydroxy-5,8,11,13-eicosatetraenoic acid; D051745:Protein Kinase C-delta; D051744:Protein Kinase C-epsilon