Department of Food and Nutrition, Kyung Hee University, 1, Hoegi-dong, Dongdaemun-gu, Seoul, 130-701, Korea.
J Appl Toxicol. 2012 Feb;32(2):118-25. doi: 10.1002/jat.1642. Epub 2011 Mar 5.
This study evaluated the effects of antimycin A (AMA), an inhibitor of electron transport in mitochondria, on the release of intracellular calcium ion (Ca(2+) ), ROS and bone resorbing factors in osteoblastic MC3T3-E1 cells. Pretreatment of osteoblasts with trolox, a ROS scavenger, and cyclosporin A, a potent inhibitor of calcium release from mitochondria, prevented the AMA-induced increases in Ca(2+) . However, Ca(2+) increase by AMA was unaffected by dantrolene, which blocks the ryanodine receptor channel of the endoplasmic reticulum. BAPTA/AM (an intracellular Ca(2+) chelator), dantrolene and cyclosporine A did not reverse the effect of AMA on ROS release. We also investigated whether intracellular calcium release inhibitor and antioxidant protect against AMA-induced bone resorbing cytokine release. Trolox prevented the release of receptor activator of nuclear factor-κB ligand (RANKL), IL-6, and TNF-α induced by AMA. Moreover, the increased IL-6 and TNF-α release by AMA was markedly reduced by BAPTA/AM and cyclosporin A. However, BAPTA/AM did not reverse the effect of AMA on osteoprotegerin and RANKL. Taken together, these results demonstrate that mitochondrial ROS generation and Ca(2+) influx by AMA is required for osteoblast death and bone resorbing cytokine release.
本研究评估了抗霉素 A（AMA），一种线粒体电子传递抑制剂，对成骨细胞 MC3T3-E1 细胞内钙离子释放 (Ca(2+) )、ROS 和破骨细胞因子释放的影响。用抗氧化剂 Trolox 和强效线粒体钙释放抑制剂环孢菌素 A 预处理成骨细胞，可防止 AMA 诱导的 Ca(2+) 增加。然而，AMA 引起的 Ca(2+) 增加不受阻断内质网兰尼碱受体通道的丹曲林影响。BAPTA/AM（细胞内 Ca(2+) 螯合剂）、丹曲林和环孢菌素 A 均不能逆转 AMA 对 ROS 释放的影响。我们还研究了细胞内钙释放抑制剂和抗氧化剂是否能防止 AMA 诱导的破骨细胞因子释放。Trolox 可防止 AMA 诱导的核因子-κB 配体受体激活剂（RANKL）、IL-6 和 TNF-α 的释放。此外，BAPTA/AM 和环孢菌素 A 可显著减少 AMA 诱导的 IL-6 和 TNF-α 释放。然而，BAPTA/AM 不能逆转 AMA 对骨保护素和 RANKL 的影响。综上所述，这些结果表明 AMA 引起的线粒体 ROS 生成和 Ca(2+) 内流是成骨细胞死亡和破骨细胞因子释放所必需的。
