Activation of 5-lipoxygenase after oxygen-glucose deprivation is partly mediated via NMDA receptor in rat cortical neurons.
5-Lipoxygenase (5-LOX) is the enzyme metabolizing arachidonic acid to produce pro-inflammatory leukotrienes. We have reported that 5-LOX is translocated to the nuclear envelope after ischemic-like injury in PC12 cells. In the present study, we determined whether 5-LOX is activated (translocation and production of leukotrienes) after oxygen-glucose deprivation (OGD) in primary rat cortical neurons; if so, whether this activation is mediated by NMDA receptor. After OGD, 5-LOX was translocated to the nuclear envelope as detected by immunoblotting, immunostaining and green fluorescent protein-5-LOX transfection. 5-LOX metabolites, cysteinyl-leukotrienes (CysLTs) but not leukotriene B4, in the culture media were increased 0.5-1.5 h after recovery. Similarly, NMDA (100 microm) also induced 5-LOX translocation, and increased the production of CysLTs during 0.5-1 h NMDA exposure. Both OGD and NMDA reduced neuron viability. NMDA receptor antagonist MK-801 inhibited almost all the responses to OGD and NMDA; whereas 5-LOX activating protein inhibitor MK-886 and 5-LOX inhibitor caffeic acid inhibited the reduction of neuron viability and the production of CysLTs, but did not affect 5-LOX translocation. From these results, we conclude that OGD can activate 5-LOX in primary rat cortical neurons, and that this activation may be partly mediated via activating NMDA receptor.
Ge
Qiu-Fu
QF
Department of Pharmacology, Zheijang University School of Medicine, Hangzhou, China.
Wei
Er-Qing
EQ
Zhang
Wei-Ping
WP
Hu
Xin
X
Huang
Xiao-Jia
XJ
Zhang
Lei
L
Song
Ying
Y
Ma
Zhen-Qiu
ZQ
Chen
Zhong
Z
Luo
Jian-Hong
JH
D021581:Active Transport, Cell Nucleus / Q000502:physiology; D000818:Animals; D000831:Animals, Newborn; D001094:Arachidonate 5-Lipoxygenase / Q000378:metabolism*; D016718:Arachidonic Acid / Q000096:biosynthesis; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000378:metabolism* / Q000503:physiopathology; D004660:Encephalitis / Q000378:metabolism / Q000503:physiopathology; D004789:Enzyme Activation / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005947:Glucose / Q000378:metabolism; D018698:Glutamic Acid / Q000378:metabolism*; D020925:Hypoxia-Ischemia, Brain / Q000378:metabolism* / Q000503:physiopathology; D015289:Leukotrienes / Q000096:biosynthesis; D016202:N-Methylaspartate / Q000494:pharmacology; D009474:Neurons / Q000378:metabolism* / Q000473:pathology; D010100:Oxygen / Q000378:metabolism; D021381:Protein Transport / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000819:agonists / Q000378:metabolism*
D004791:Enzyme Inhibitors; D018691:Excitatory Amino Acid Antagonists; D015289:Leukotrienes; D016194:Receptors, N-Methyl-D-Aspartate; D016718:Arachidonic Acid; D018698:Glutamic Acid; D016202:N-Methylaspartate; D001094:Arachidonate 5-Lipoxygenase; D005947:Glucose; D010100:Oxygen