Choi Eun Mi, Jung Woon Won, Suh Kwang Sik
Department of Food and Nutrition, Kyung Hee University, Seoul 130‑701, Republic of Korea.
Department of Biomedical Laboratory Science, College of Health Sciences, Cheongju University, Cheongju, Chungcheong 360-764, Republic of Korea.
Mol Med Rep. 2015 Jan;11(1):746-52. doi: 10.3892/mmr.2014.2721. Epub 2014 Oct 21.
The present study aimed to investigate the protective effect of a non-selective mitochondrial adenosine triphosphate (ATP)-sensitive potassium channel (mito-KATP) opener, pinacidil, on antimycin A-induced oxidative damage in osteoblastic MC3T3-E1 cells. Antimycin A inhibits mitochondrial electron transport by binding to complex III. Osteoblastic MC3T3-E1 cells were treated with antimycin A in the presence or absence of pinacidil and markers of mitochondrial function and oxidative stress were subsequently examined. The effects of pinacidil on the activation of phosphoinositide 3-kinase (PI3K), Akt and cyclic adenosine monophosphate‑responsive element-binding protein (CREB) were also examined. In osteoblastic MC3T3-E1 cells exposed to antimycin A, pinacidil inhibited antimycin A-induced cell death. The protective effects of pinacidil on cell survival were prevented by the addition of LY294002 (a PI3K inhibitor), an Akt inhibitor or auranofin [a thioredoxin reductase (TrxR) inhibitor], but not by KATP channel inhibitor glibenclamide. Pinacidil inhibited antimycin A-induced inactivation of PI3K and Akt as well as phosphorylation of CREB and TrxR. Furthermore, pinacidil prevented antimycin A-induced mitochondrial superoxide release, mitochondrial membrane potential dissipation, reduced ATP synthesis and intracellular [Ca2+] elevation. In conclusion, these results suggested that pinacidil may rescue osteoblastic cells from antimycin A-induced cellular damage, potentially via antioxidant activity and restoration of mitochondrial function, which are mediated in part by the PI3K/Akt/CREB signaling pathway.
本研究旨在探讨非选择性线粒体三磷酸腺苷（ATP）敏感性钾通道（mito-KATP）开放剂吡那地尔对抗霉素A诱导的成骨细胞MC3T3-E1细胞氧化损伤的保护作用。抗霉素A通过与复合物III结合来抑制线粒体电子传递。在有或没有吡那地尔存在的情况下，用抗霉素A处理成骨细胞MC3T3-E1细胞，随后检测线粒体功能和氧化应激的标志物。还检测了吡那地尔对磷酸肌醇3-激酶（PI3K）、Akt和环磷酸腺苷反应元件结合蛋白（CREB）激活的影响。在暴露于抗霉素A的成骨细胞MC3T3-E1细胞中，吡那地尔抑制了抗霉素A诱导的细胞死亡。加入LY294002（一种PI3K抑制剂）、Akt抑制剂或金诺芬[一种硫氧还蛋白还原酶（TrxR）抑制剂]可阻止吡那地尔对细胞存活的保护作用，但KATP通道抑制剂格列本脲则不能。吡那地尔抑制了抗霉素A诱导的PI3K和Akt失活以及CREB和TrxR的磷酸化。此外，吡那地尔还阻止了抗霉素A诱导的线粒体超氧化物释放、线粒体膜电位耗散、ATP合成减少和细胞内[Ca2+]升高。总之，这些结果表明，吡那地尔可能通过抗氧化活性和线粒体功能的恢复，部分通过PI3K/Akt/CREB信号通路介导，从而使成骨细胞免受抗霉素A诱导的细胞损伤。
