Calcium-induced permeability transition in rat brain mitochondria is promoted by carbenoxolone through targeting connexin43
Calcium-induced permeability transition in rat brain mitochondria is promoted by carbenoxolone through targeting connexin43
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DOI：
10.1152/ajpcell.00061.2010
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发表时间：
2011-03-01
影响因子：
5.5
通讯作者：
Reiser, Georg
中科院分区：
文献类型：
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作者：
Azarashvili, Tamara;Baburina, Yulia;Reiser, Georg
Azarashvili T, Baburina Y, Grachev D, Krestinina O, Evtodienko Y, Stricker R, Reiser G. carbenoxolone通过靶向connexin43促进钙诱导的大鼠脑线粒体通透性转变。[J] .中国生物医学工程学报，2016,31(2):557 - 557。首次发表于2010年12月9日；doi: 10.1152 / ajpcell.00061.2010。-卡贝诺洛酮（Cbx），一种从药用甘草中提取的物质，用于抗炎治疗。我们研究了Cbx对Ca2+诱导的大鼠突触性和非突触性脑线粒体（RBM）以及大鼠肝脏线粒体（RLM）通透性过渡孔（PTP）打开的作用机制，试图确定Cbx在线粒体中的分子靶点。暴露于阈值Ca2+负荷诱导PTP开放，正如从线粒体基质中突然流出的Ca2+和膜电位崩溃所见。在突触性RBM中，Cbx （1 μ M）促进Ca2+诱导的环孢素a敏感的PTP打开，而在非突触性线粒体中，Cbx阈值浓度更高。Cbx的一个众所周知的分子靶点是连接蛋白（Cx）家族，即间隙连接蛋白。此外，Cx43先前在心脏线粒体中被发现，并归因于预处理保护机制。因此，我们假设Cx43可能是脑线粒体中Cbx的靶点。我们首次在RBM中检测到Cx43，但在RLM中未检测到Cx43。有趣的是，两种针对大鼠Cx43氨基酸252至270的抗Cx43抗体，消除了cbx诱导的总RBM和突触线粒体PTP开放的增强，但对RLM没有作用。在总RBM和突触线粒体中，PTP引起Cx43在丝氨酸368处的去磷酸化。丝氨酸368的磷酸化水平在阈值钙浓度下降低，另外在突触线粒体中Cbx的联合存在下也降低。总之，活跃的线粒体Cx43似乎可以抵消Ca2+诱导的PTP打开，从而可能抑制PTP引起的线粒体死亡和细胞死亡。因此，我们认为脑线粒体中Cx43的活性代表了一种新的分子保护靶点。
Azarashvili T, Baburina Y, Grachev D, Krestinina O, Evtodienko Y, Stricker R, Reiser G. Calcium-induced permeability transition in rat brain mitochondria is promoted by carbenoxolone through targeting connexin43. Am J Physiol Cell Physiol 300: C707-C720, 2011. First published December 9, 2010; doi: 10.1152/ajpcell.00061.2010.-Carbenoxolone (Cbx), a substance from medicinal licorice, is used for antiinflammatory treatments. We investigated the mechanism of action of Cbx on Ca2+ -induced permeability transition pore (PTP) opening in synaptic and nonsynaptic rat brain mitochondria (RBM), as well as in rat liver mitochondria (RLM), in an attempt to identify the molecular target of Cbx in mitochondria. Exposure to threshold Ca2+ load induced PTP opening, as seen by sudden Ca2+ efflux from the mitochondrial matrix and membrane potential collapse. In synaptic RBM, Cbx (1 mu M) facilitated the Ca2+ -induced, cyclosporine A-sensitive PTP opening, while in nonsynaptic mitochondria the Cbx threshold concentration was higher. A well-known molecular target of Cbx is the connexin (Cx) family, gap junction proteins. Moreover, Cx43 was previously found in heart mitochondria and attributed to the preconditioning mechanism of protection. Thus, we hypothesized that Cx43 might be a target for Cbx in brain mitochondria. For the first time, we detected Cx43 by Western blot in RBM, but Cx43 was absent in RLM. Interestingly, two anti-Cx43 antibodies, directed against amino acids 252 to 270 of rat Cx43, abolished the Cbx-induced enhancement of PTP opening in total RBM and in synaptic mitochondria, but not in RLM. In total RBM and in synaptic mitochondria, PTP caused dephosphorylation of Cx43 at serine 368. The phosphorylation level of serine 368 was decreased at threshold calcium concentration and additionally in the combined presence of Cbx in synaptic mitochondria. In conclusion, active mitochondrial Cx43 appears to counteract the Ca2+ -induced PTP opening and thus might inhibit the PTP-ensuing mitochondrial demise and cell death. Consequently, we suggest that activity of Cx43 in brain mitochondria represents a novel molecular target for protection.