α7 nicotinic acetylcholine receptors control cytochrome c release from isolated mitochondria through kinase-mediated pathways
α7 nicotinic acetylcholine receptors control cytochrome c release from isolated mitochondria through kinase-mediated pathways
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DOI：
10.1016/j.biocel.2014.01.001
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发表时间：
2014-04-01
影响因子：
4
通讯作者：
Skok, Maryna
中科院分区：
文献类型：
--
作者：
Gergalova, Galyna;Lykhmus, Olena;Skok, Maryna
烟碱型乙酰胆碱受体是在可兴奋和不可兴奋细胞的质膜中发现的配体门控离子通道。先前我们报道了含有α 7亚基的烟碱受体存在于线粒体的外膜中，以调节细胞色素c释放等早期凋亡事件。在这里，我们表明，线粒体α 7烟碱受体的信号影响线粒体内蛋白激酶。α 7烟碱受体激动剂PNU 282987（30 nM）阻止了磷脂酰肌醇-3-激酶抑制剂渥曼青霉素的作用，该抑制剂刺激了分离的小鼠肝线粒体中细胞色素c的释放，并恢复了90 μ M Ca 2+或渥曼青霉素降低的Akt（Ser 473）磷酸化状态。PNU 282987的作用与钙-钙调蛋白依赖性激酶II（90 μ M Ca 2+）或Src激酶（0.5 mM H2 O2）和蛋白激酶C的抑制作用相似。细胞色素c从线粒体的释放也可以减弱α 7烟碱受体拮抗剂甲基乌头碱或α 7特异性抗体。变构调节剂PNU 120526（1 μ M）不能改善激动剂PNU 282987的作用。乙酰胆碱（1 μ M）和methyllicaconitine（10 nM）抑制超氧化物释放线粒体测量根据碱化的Ca 2+含铟。结论：α 7烟碱受体通过激活线粒体内PI 3 K/Akt信号通路，抑制钙-钙调蛋白依赖或Src激酶依赖信号通路等离子非依赖性机制调控线粒体通透性转换孔的形成。(C)2014爱思唯尔有限公司版权所有。
Nicotinic acetylcholine receptors are ligand-gated ion channels found in the plasma membrane of both excitable and non-excitable cells. Previously we reported that nicotinic receptors containing alpha 7 subunits were present in the outer membranes of mitochondria to regulate the early apoptotic events like cytochrome c release. Here we show that signaling of mitochondrial alpha 7 nicotinic receptors affects intramitochondrial protein kinases. Agonist of alpha 7 nicotinic receptors PNU 282987 (30 nM) prevented the effect of phosphatidyl inositol-3-kinase inhibitor wortmannin, which stimulated cytochrome c release in isolated mouse liver mitochondria, and restored the Akt (Ser 473) phosphorylation state decreased by either 90 mu M Ca2+ or wortmannin. The effect of PNU 282987 was similar to inhibition of calcium-calmodulin-dependent kinase II (upon 90 mu M Ca2+) or of Src kinase(s) (upon 0.5 mM H2O2) and of protein kinase C. Cytochrome c release from mitochondria could be also attenuated by alpha 7 nicotinic receptor antagonist methyllicaconitine or alpha 7-specific antibodies. Allosteric modulator PNU 120526 (1 mu M) did not improve the effect of agonist PNU 282987. Acetylcholine (1 mu M) and methyllicaconitine (10 nM) inhibited superoxide release from mitochondria measured according to alkalization of Ca2+-containing inedium. It is concluded that alpha 7 nicotinic receptors regulate mitochondrial permeability transition pore formation through ion-independent mechanism involving activation of intramitochondrial PI3K/Akt pathway and inhibition of calcium-calmodulin-dependent or Src-kinase-dependent signaling pathways. (C) 2014 Elsevier Ltd. All rights reserved.