Carbenoxolone induces permeability transition pore opening in rat mitochondria via the translocator protein TSPO and connexin43.
Carbenoxolone induces permeability transition pore opening in rat mitochondria via the translocator protein TSPO and connexin43.
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DOI：
10.1016/j.abb.2014.06.027
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发表时间：
2014-09-15
影响因子：
3.9
通讯作者：
Reiser G
中科院分区：
文献类型：
--
作者：
Azarashvili T;Baburina Y;Grachev D;Krestinina O;Papadopoulos V;Lemasters JJ;Odinokova I;Reiser G
Ca2+诱导的大鼠脑线粒体通透性过渡孔（mPTP）打开是通过靶向connexin43来促进的。阈值Ca2+负荷后，线粒体膜电位下降，线粒体基质中积累的Ca2+发生外排，表明mPTP打开。利用特异性抗体评估转运蛋白（18 kDa； TSPO）和connexin43在卡贝诺洛酮和内源性TSPO配体原卟啉IX诱导的离体大鼠肝和脑线粒体肿胀中的作用。采用选择性电极测定线粒体膜电位、Ca2+转运和耗氧量。在选择电极的腔室中同时检测所有参数。评估线粒体蛋白靶点的磷酸化状态。我们报道Ca2+诱导的线粒体肿胀在卡贝诺洛酮和原卟啉IX的存在下得到加强。卡贝诺酮和原卟啉ix加速脑线粒体mPTP的诱导被线粒体转位蛋白（TSPO）特异性抗体完全阻止。抗tspo抗体比抗connexin43抗体更有效。此外，卡贝诺洛酮刺激的线粒体蛋白磷酸化被抗tspo抗体抑制。综上所述，这些数据表明，除了通过连接43起作用外，卡贝诺洛酮还可能通过线粒体外膜TSPO对mPTP产生影响。
Ca2+-induced permeability transition pore (mPTP) opening in isolated rat brain mitochondria is promoted through targeting of connexin43. After a threshold Ca2+ load, mitochondrial membrane potential drops and efflux of accumulated Ca2+ from the mitochondrial matrix occurs, indicating the mPTP opening. Specific antibodies were used to assess the role of the translocator protein (18 kDa; TSPO) and connexin43 in swelling of isolated rat liver and brain mitochondria induced by carbenoxolone and the endogenous TSPO ligand protoporphyrin IX. Mitochondrial membrane potential, Ca2+ transport and oxygen consumption were determined using selective electrodes. All the parameters were detected simultaneously in a chamber with the selective electrodes. The phosphorylation state of mitochondrial protein targets was assessed. We report that Ca2+-induced mitochondrial swelling was strengthened in the presence of both carbenoxolone and protoporphyrin IX. The carbenoxolone- and protoporphyrin IX-accelerated mPTP induction in brain mitochondria was completely prevented by antibodies specific for the mitochondrial translocator protein (TSPO). The anti-TSPO antibodies were more effective than anti-connexin43 antibodies. Moreover, carbenoxolone-stimulated phosphorylation of mitochondrial proteins was inhibited by anti-TSPO antibodies. Taken together, the data suggests that, in addition to acting via connexion43, carbenoxolone may exert its effect on mPTP via mitochondrial outer membrane TSPO.