Protection against cardiac injury by small Ca(2+)-sensitive K(+) channels identified in guinea pig cardiac inner mitochondrial membrane.
Protection against cardiac injury by small Ca(2+)-sensitive K(+) channels identified in guinea pig cardiac inner mitochondrial membrane.
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DOI：
10.1016/j.bbamem.2012.08.031
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发表时间：
2013-02
影响因子：
3.4
通讯作者：
Camara, Amadou K. S.
中科院分区：
文献类型：
--
作者：
Stowe, David F.;Gadicherla, Ashish K.;Zhou, Yifan;Aldakkak, Mohammed;Cheng, Qunli;Kwok, Wai-Meng;Jiang, Ming Tao;Heisner, James S.;Yang, MeiYing;Camara, Amadou K. S.
关键词：
我们测试了小电导、钙敏感的K+通道(SKCa)是否通过改善线粒体(M)生物能量学来预适应心脏的缺血再灌注(IR)损伤，是否需要O2衍生的自由基通过SKCa通道来启动保护，以及更重要的是，如果SKCa通道存在于心肌细胞内线粒体膜(IMM)中。用荧光分光光度法测定豚鼠离体心组织中NADH、FAD、超氧阴离子(O2·−)和m[Ca~(2+)]。给予SKCa和IKCa通道开放剂DCEBIO(DCEB)10min，至IR前20min结束。在DCEB前和缺血前分别给予O2·−的转移剂TbAP、SKCa亚型的拮抗剂NS8593或其他Kca和KATP通道拮抗剂。DCEB治疗后再灌流时左室压增加2倍，心肌梗死面积缩小2.5倍，O2·−和m[Ca~(2+)]降低，NADH和FAD在IR期间恢复正常。只有NS8593和TBAP能拮抗DCEB的保护作用。通过Western blotting、免疫组织化学染色、共聚焦显微镜和免疫金电子显微镜鉴定纯化的mSKCa蛋白，b)IMM蛋白的双向凝胶电泳法和质谱仪，c)平面脂质双分子层中mSKCa通道的[Ca~(2+)]依赖性，以及d)DCEB诱导并被SKCa拮抗剂UCL1684阻断的基质K+内流。本研究结果表明：(1)在IMM中，SKCa通道存在并发挥作用；(2)DCEB开放MSKCa通道可引起O2·−依赖的保护作用；(3)DCEB对IMM具有明显的保护作用。
We tested if small conductance, Ca2+-sensitive K+ channels (SKCa) precondition hearts against ischemia reperfusion (IR) injury by improving mitochondrial (m) bioenergetics, if O2–derived free radicals are required to initiate protection via SKCa channels, and, importantly, if SKCa channels are present in cardiac cell inner mitochondrial membrane (IMM). NADH and FAD, superoxide (O2•−), and m[Ca2+] were measured in guinea pig isolated hearts by fluorescence spectrophotometry. SKCa and IKCa channel opener DCEBIO (DCEB) was given for 10 min ending 20 min before IR. Either TBAP, a dismutator of O2•−, NS8593, an antagonist of SKCa isoforms, or other KCa and KATP channel antagonists, was given before DCEB and before ischemia. DCEB treatment resulted in a 2-fold increase in LV pressure on reperfusion and a 2.5 fold decrease in infarct size vs. non-treated hearts associated with reduced O2•− and m[Ca2+], and more normalized NADH and FAD during IR. Only NS8593 and TBAP antagonized protection by DCEB. Localization of SKCa channels to mitochondria and IMM was evidenced by a) identification of purified mSKCa protein by Western blotting, immuno-histochemical staining, confocal microscopy, and immuno-gold electron microscopy, b) 2-D gel electrophoresis and mass spectroscopy of IMM protein, c) [Ca2+]–dependence of mSKCa channels in planar lipid bilayers, and d) matrix K+ influx induced by DCEB and blocked by SKCa antagonist UCL1684. This study shows that 1) SKCa channels are located and functional in IMM, 2) mSKCa channel opening by DCEB leads to protection that is O2•− dependent, and 3) protection by DCEB is evident beginning during ischemia.
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影响因子：
3.2
作者：
BERRYMAN, MA;RODEWALD, RD
通讯作者：
RODEWALD, RD
影响因子：
20.1
作者：
Forbes, RA;Steenbergen, C;Murphy, E
通讯作者：
Murphy, E
影响因子：
5.5
作者：
Aldakkak, Mohammed;Stowe, David F.;Camara, Amadou K. S.
通讯作者：
Camara, Amadou K. S.
影响因子：
3
作者：
An, JZ;Camara, AKS;Stowe, DF
通讯作者：
Stowe, DF
影响因子：
3.3
作者：
Douglas, R. M.;Lai, J. C. K.;Haddad, G. G.
通讯作者：
Haddad, G. G.