Translocation of Protein Kinase C Isoforms to Subcellular Targets in Ischemic and Anesthetic Preconditioning
Translocation of Protein Kinase C Isoforms to Subcellular Targets in Ischemic and Anesthetic Preconditioning
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DOI：
10.1097/00000542-200307000-00023
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发表时间：
2003-07
期刊：
影响因子：
8.8
通讯作者：
Marina Uecker;R. D. da Silva;T. Grampp;T. Pasch;M. Schaub;M. Zaugg
中科院分区：
文献类型：
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作者：
Marina Uecker;R. D. da Silva;T. Grampp;T. Pasch;M. Schaub;M. Zaugg
蛋白激酶C （PKC）向亚细胞靶点的易位是缺血预处理（IPC）过程中一个关键的信号传导步骤。然而，迄今为止，PKC异构体是否在麻醉预处理（APC）中移位尚不清楚。方法采用PKC阻滞剂chelerythrine和rotlerin，以及三磷酸腺苷依赖性钾（KATP）通道阻滞剂HMR-1098和5-羟基乙酸酯，对缺血40 min和再灌注30 min后离体灌注大鼠心脏进行IPC或APC（1.5最小肺泡浓度异氟醚）后PKC和KATP通道的作用进行评价。免疫组织化学技术用于预适应后PKC易位的可视化。此外，我们还评估了PKC亚型的磷酸化状态。结果赤藓碱、鹿茸素和5-羟基癸酸酯对IPC和APC的功能恢复有抑制作用，但IPC浓度较高。HMR-1098不影响IPC或APC。在IPC和APC中，PKC和PKC均向细胞核内转移，而chelerythrine和rotlerin均能抑制PKC向细胞核内转移。PKC易位到线粒体而不易位到肌膜，PKC易位到肌膜和嵌入盘而不易位到线粒体。有趣的是，PKC在对照组和预处理心脏的插入盘处积累。PKC对丝氨酸643的磷酸化在IPC和APC中增加，并被车红素和车红素阻断，而PKC对苏氨酸505的磷酸化仅在IPC中增加，而不被车红素和车红素阻断。丝氨酸729上的PKC没有改变其磷酸化状态。本研究表明，PKC易位在IPC和APC中起着关键作用，PKC丝氨酸643的磷酸化可能与APC刺激转移到线粒体KATP通道特别相关。
Background Translocation of protein kinase C (PKC) to subcellular targets is a pivotal signaling step in ischemic preconditioning (IPC). However, to date, it is unknown whether PKC isoforms translocate in anesthetic preconditioning (APC). Methods The PKC blockers chelerythrine and rottlerin and the adenosine triphosphate–dependent potassium (KATP) channel blockers HMR-1098 and 5-hydroxydecanoate were used to assess the role of PKC and KATP channels in isolated perfused rat hearts subjected to IPC or APC (1.5 minimum alveolar concentration isoflurane) followed by 40 min of ischemia and 30 min of reperfusion. Immunohistochemical techniques were used to visualize PKC translocation after preconditioning. In addition, the phosphorylation status of PKC isoforms was assessed. Results Chelerythrine, rottlerin, and 5-hydroxydecanoate blocked IPC and APC with respect to functional recovery, albeit IPC at higher concentrations. HMR-1098 did not affect IPC or APC. PKC and PKC translocated to nuclei in both IPC and APC, which was inhibited by chelerythrine and rottlerin. PKC translocated to mitochondria but not to the sarcolemma, and PKC translocated to the sarcolemma and intercalated disks but not to mitochondria. Interestingly, PKC was accumulated at the intercalated disks in control and preconditioned hearts. Phosphorylation of PKC on serine643 was increased in IPC and APC and blocked by chelerythrine and rottlerin, whereas phosphorylation of PKC on threonine505 was increased only in IPC and not blocked by chelerythrine or rottlerin. PKC on serine729 did not change its phosphorylation status. Conclusions This study indicates that translocation of PKC plays a pivotal role in IPC and APC and suggests that phosphorylation of PKC on serine643 may be of particular relevance in transferring the APC stimulus to mitochondrial KATP channels.