Differential loss of cytochrome-c oxidase subunits in ischemia-reperfusion injury: exacerbation of COI subunit loss by PKC-epsilon inhibition.
Differential loss of cytochrome-c oxidase subunits in ischemia-reperfusion injury: exacerbation of COI subunit loss by PKC-epsilon inhibition.
复制标题
DOI：
10.1152/ajpheart.91476.2007
复制
发表时间：
2008-06
期刊：
影响因子：
--
通讯作者：
Qilin Yu;T. Nguyen;Mourad Ogbi;R. Caldwell;John A. Johnson
中科院分区：
文献类型：
--
作者：
Qilin Yu;T. Nguyen;Mourad Ogbi;R. Caldwell;John A. Johnson
我们先前已经描述了PKC-β与细胞色素氧化酶亚基IV（COIV）的相互作用，与增强的CO活性和心脏缺血预处理（PC）相关。因此，我们研究了PC和缺血再灌注（I/R）损伤对CO亚基水平的影响在麻醉大鼠冠状动脉结扎模型。将从I/R损伤的风险（RAR）和非风险（RNAR）左心室区域制备的匀浆分级为细胞可溶性（S）、600 g低速离心（L）、梯度纯化的线粒体（M）和100，000 g颗粒（P）级分。在RAR组织中，PC（2个循环的5分钟缺血和5分钟再灌注）降低了P组分中的COI（约占总细胞COI的29%），表明原纤维间线粒体发生了变化。在缺血30分钟和再灌注120分钟后，RAR中的总COI水平下降了72%。亚基Va也下调了42%，在RAR延长I/R。在I/R前给予PC使M和P组分中的COI损失减少约30%，并完全防止COVa损失。我们观察到单独I/R后亚基Vb和VIIa没有损失;然而，当在延长I/R前给予PC时，亚基Vb和VIIa发生显著损失。在长时间I/R之前，向离体大鼠心脏递送细胞可渗透的PKC-β易位抑制剂（epsilonV 1 -2）显著增加COI损失，表明PKC-β保护COI水平。我们建议，额外的措施，以保护CO亚基时，与PC共同管理可能会提高其对I/R损伤的心脏保护。
We have previously described a PKC-epsilon interaction with cytochrome oxidase subunit IV (COIV) that correlates with enhanced CO activity and cardiac ischemic preconditioning (PC). We therefore investigated the effects of PC and ischemia-reperfusion (I/R) injury on CO subunit levels in an anesthetized rat coronary ligation model. Homogenates prepared from the left ventricular regions at risk (RAR) and not at risk (RNAR) for I/R injury were fractionated into cell-soluble (S), 600 g low-speed centrifugation (L), gradient-purified mitochondrial (M), and 100,000 g particulate (P) fractions. In RAR tissue, PC (2 cycles of 5-min ischemia and 5-min reperfusion) decreased the COI in the P fraction ( approximately 29% of total cellular COI), suggesting changes in interfibrillar mitochondria. After 30 min of ischemia and 120 min of reperfusion, total COI levels decreased in the RAR by 72%. Subunit Va was also downregulated by 42% following prolonged I/R in the RAR. PC administered before I/R reduced the loss of COI in the M and P fractions approximately 30% and prevented COVa losses completely. We observed no losses in subunits Vb and VIIa following I/R alone; however, significant losses occurred when PC was administered before prolonged I/R. Delivery of a cell-permeable PKC-epsilon translocation inhibitor (epsilonV1-2) to isolated rat hearts before prolonged I/R dramatically increased COI loss, suggesting that PKC-epsilon protects COI levels. We propose that additional measures to protect CO subunits when coadministered with PC may improve its cardioprotection against I/R injury.