Yang Xiayun, Tang Shusheng, Dai Chongshan, Li Daowen, Zhang Shen, Deng Sijun, Zhou Yan, Xiao Xilong
Department of Pharmacology and Toxicology, College of Veterinary Medicine, China Agricultural University, Yuanmingyuan West Road No. 2, Beijing, Haidian District 100193, China.
Department of Pharmacology and Toxicology, College of Veterinary Medicine, China Agricultural University, Yuanmingyuan West Road No. 2, Beijing, Haidian District 100193, China.
Food Chem Toxicol. 2017 Jul;105:161-176. doi: 10.1016/j.fct.2017.03.039. Epub 2017 Mar 23.
Quinocetone (QCT) has been used as an animal feed additive in China since 2003. However, investigations indicate that QCT has potential toxicity due to the fact that it shows cytotoxicity, genotoxicity, hepatotoxicity, nephrotoxicity and immunotoxicity in vitro and animal models. Although QCT-induced mitochondrial apoptosis has been established, the molecular mechanism remains unclear. This study was aimed to investigate the role of voltage-dependent anion channel 1 (VDAC1) oligomerization and Wnt/β-catenin pathway in QCT-induced mitochondrial apoptosis. The results showed VDAC inhibitor 4, 4-diisothiocyano stilbene-2, 2-disulfonic acid (DIDS) partly compromised QCT-induced cell viability decrease (from 34.1% to 68.5%) and mitochondrial apoptosis accompanied by abating VDAC1 oligomerization, cytochrome c (Cyt c) release and the expression levels of cleaved caspase-9, -3 and poly (ADP-ribose) polymerase (PARP). Meanwhile, overexpression VDAC1 exacerbated QCT-induced VDAC1 oligomerization and Cyt c release. In addition, lithium chloride (LiCl), an activator of Wnt/β-catenin pathway, markedly attenuated QCT-induced mitochondrial apoptosis by partly restoring the expression levels of Wnt1 and β-catenin. Finally, reactive oxygen species (ROS) scavenger N-acetyl-l-cysteine (NAC) obviously blocked QCT-induced VDAC1 oligomerization and the inhibition of Wnt1/β-catenin pathway. Taken together, our results reveal that QCT induces mitochondrial apoptosis by ROS-dependent promotion of VDAC1 oligomerization and suppression of Wnt1/β-catenin pathway.
喹烯酮（QCT）自2003年起在中国被用作动物饲料添加剂。然而，调查表明QCT具有潜在毒性，因为它在体外和动物模型中表现出细胞毒性、遗传毒性、肝毒性、肾毒性和免疫毒性。尽管QCT诱导的线粒体凋亡已得到证实，但其分子机制仍不清楚。本研究旨在探讨电压依赖性阴离子通道1（VDAC1）寡聚化和Wnt/β-连环蛋白通路在QCT诱导的线粒体凋亡中的作用。结果显示，VDAC抑制剂4,4-二异硫氰基芪-2,2-二磺酸（DIDS）部分缓解了QCT诱导的细胞活力下降（从34.1%降至68.5%）以及线粒体凋亡，同时减少了VDAC1寡聚化、细胞色素c（Cyt c）释放以及裂解的半胱天冬酶-9、-3和聚（ADP-核糖）聚合酶（PARP）的表达水平。同时，VDAC1过表达加剧了QCT诱导的VDAC1寡聚化和Cyt c释放。此外，Wnt/β-连环蛋白通路激活剂氯化锂（LiCl）通过部分恢复Wnt1和β-连环蛋白的表达水平，显著减轻了QCT诱导的线粒体凋亡。最后，活性氧（ROS）清除剂N-乙酰-L-半胱氨酸（NAC）明显阻断了QCT诱导的VDAC1寡聚化以及对Wnt1/β-连环蛋白通路的抑制。综上所述，我们的结果表明，QCT通过ROS依赖的方式促进VDAC1寡聚化并抑制Wnt1/β-连环蛋白通路来诱导线粒体凋亡。
