Spatio-temporal properties of 5-lipoxygenase expression and activation in the brain after focal cerebral ischemia in rats

• Published in: Life sciences (1973) Vol. 79; no. 17; pp. 1645 - 1656
• Main Authors: Zhou, Yu, Wei, Er-Qing, Fang, San-Hua, Chu, Li-Sheng, Wang, Meng-Ling, Zhang, Wei-Ping, Yu, Guo-Liang, Ye, Yi-Lu, Lin, Shu-Cai, Chen, Zhong
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 20.09.2006
• Subjects: 5-lipoxygenase; Acute Disease; Animals; Arachidonate 5-Lipoxygenase - biosynthesis; Arachidonate 5-Lipoxygenase - genetics; Arterial Occlusive Diseases - metabolism; Astrocyte; Astrocytes - enzymology; Astrocytes - pathology; Brain - enzymology; Brain - pathology; Cell Proliferation; Chronic Disease; Disease Models, Animal; Enzyme Activation; Focal cerebral ischemia; Gene Expression; Immunoenzyme Techniques; Ischemic Attack, Transient - enzymology; Ischemic Attack, Transient - pathology; Leukotrienes; Leukotrienes - metabolism; Male; Neuron; Neurons - enzymology; Neurons - pathology; Rats; Rats, Sprague-Dawley; Reperfusion Injury - enzymology; Reperfusion Injury - pathology; RNA, Messenger - metabolism; Time Factors; Focal cerebral ischemia; Neuron; Astrocyte; 5-lipoxygenase; Leukotrienes
• ISSN: 0024-3205; 1879-0631
• DOI: 10.1016/j.lfs.2006.05.022

The role of 5-lipoxygenase (5-LOX) in brain injury after cerebral ischemia has been reported; however, the spatio-temporal properties of 5-LOX expression and the enzymatic activation are unclear. To determine these properties, we observed post-ischemic 5-LOX changes from 3 h to 14 days after reperfusion in rats with transient focal cerebral ischemia induced by 30 min of middle cerebral artery occlusion. We found that the expression of 5-LOX, both mRNA and protein, was increased in the ischemic core 12–24 h after reperfusion, and in the boundary zone adjacent to the ischemic core 7–14 days after reperfusion. The increased 5-LOX was primarily localized in the neurons in the ischemic core at 24 h, but in the proliferated astrocytes in the boundary zone 14 days after reperfusion. As 5-LOX metabolites, the level of cysteinyl-leukotrienes in the ischemic brain was substantially increased 3 h to 24 h, near control at 3 days, and moderately increased again 7 days after reperfusion; whereas the level of LTB 4 was increased mildly 3 h but substantially 7–14 days after reperfusion. Thus, we conclude that 5-LOX expression and the enzymatic activity are increased after focal cerebral ischemia, and spatio-temporally involved in neuron injury in the acute phase and astrocyte proliferation in the late phase.