Arachidonic acid protects neonatal rat cardiac myocytes from ischaemic injury through ε protein kinase C
Arachidonic acid protects neonatal rat cardiac myocytes from ischaemic injury through ε protein kinase C
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DOI：
10.1016/s0008-6363(00)00322-9
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发表时间：
2001-04-01
影响因子：
10.8
通讯作者：
Mochly-Rosen, D
中科院分区：
文献类型：
--
作者：
Mackay, K;Mochly-Rosen, D
目的：Amchidonic acid是激活蛋白激酶C（PKC）的第二信使，在缺血预处理期间从心脏释放。本研究的目的是研究花生四烯酸对心肌细胞PRC激活的影响及其细胞后果。方法：分离培养新生大鼠心肌细胞。花生四烯酸诱导的PKC激活通过细胞分级分离和蛋白质印迹分析来检查。通过在显微镜下目视检查来测量收缩频率。通过在不存在葡萄糖的情况下使细胞处于低于0.5%氧气的气氛中来模拟缺血，并且通过释放胞质乳酸脱氢酶或直接细胞活力测定来确定细胞损伤。结果如下：花生四烯酸导致δ和β PKC易位，但不导致α、β II、eta或zeta PKC同工酶易位，表明仅激活δ和β PKC。Amchidonic acid诱导心肌细胞自发收缩率呈剂量依赖性降低，这种降低可被一种选择性的PKC肽转位抑制剂阻断。花生四烯酸预处理部分保护心肌细胞免受缺血。4 β-佛波醇、12-肉豆蔻酸酯、13-乙酸酯处理24 h下调PKC、白屈菜红碱抑制PKC和选择性抑制PKC转位均降低花生四烯酸的保护作用。用二十碳五烯酸或油酸预处理也保护心肌细胞免受缺血。结论：这些结果表明，花生四烯酸选择性激活δ和δ PKC在新生大鼠心肌细胞，导致缺血保护。我们认为这是PC过程中PKC激活的一个潜在机制。此外，我们的研究结果表明，不同类别的游离脂肪酸直接发挥心肌细胞缺血损伤的心脏保护作用。(C)2001爱思唯尔科技有限公司。保留所有权利。
Objectives: Amchidonic acid is a second messenger which activates protein kinase C (PKC) and is released from the heart during ischaemic preconditioning. The purpose of this study was to examine the effect of arachidonic acid on activation of PRC in cardiac myocytes and the cellular consequences. Methods: Neonatal rat cardiac myocytes were isolated and maintained in culture. Arachidonic acid-induced activation of PKC was examined by cell fractionation and western blot analysis. Contraction frequency was measured by visual inspection under a microscope. Ischaemia was simulated by subjecting cells to an atmosphere of lower than 0.5% oxygen in the absence of glucose and cell damage determined by release of cytosolic lactate dehydrogenase or direst cell viability assay. Results: Arachidonic acid resulted in translocation of delta and epsilon PKC but not alpha, beta II, eta or zeta PKC isozymes, indicating activation of only delta and epsilon PKC. Amchidonic acid induced a dose-dependent decrease in spontaneous contraction rate of cardiac myocytes which was blocked by a selective peptide translocation inhibitor of epsilon PKC. Pretreatment with arachidonic acid partially protected cardiac myocytes against ischaemia. Down-regulation of PKC with 24 h 4 beta -phorbol,12-myristate,13-acetate treatment, inhibition of PKC by chelerythrine and selective inhibition of epsilon PKC translocation all decreased the protective effect of arachidonic acid. Pretreatment with eicosapentaenoic acid or oleic acid also protected cardiac myocytes against ischaemia. Conclusions: These results demonstrate that arachidonic acid selectively activates delta and epsilon PKC in neonatal rat cardiac myocytes, leading to protection from ischaemia. We suggest this is a potential mechanism of PKC activation during PC. In addition, our results suggest that different classes of free fatty acid directly exert cardioprotection from ischaemic injury in cardiac myocytes. (C) 2001 Elsevier Science B.V. All rights reserved.