Wang Haixu, Li Yan, Liu Chuang, Lu Tianxiang, Zhai Qian, Wang Hongna, Zhang Jianfang
Department of Obstetrics and Gynecology, the First Affiliated Hospital of The Fourth Military Medical University, China.
J Toxicol Sci. 2023;48(3):109-119. doi: 10.2131/jts.48.109.
Bisphenol A (BPA), one of the main components of industrial products, is clinically associated with the increased male infertility rate. However, the underlying molecular mechanism of the BPA-resulted reproductive toxicity is not fully elucidated. Voltage-dependent anion channel 1 (VDAC1) is a pore protein and located at the outer mitochondrial membrane. As a mitochondrial gatekeeper, VDAC1 controls the release of reactive oxygen species (ROS) and the metabolic and energetic functions of mitochondria, and serves as a critical player in mitochondrial-mediated apoptosis. Herein, we explored the role of VDAC1 in BPA-induced apoptosis of spermatogonia. The results showed that BPA increased spermatogonia cell line GC-1 spg cell apoptosis and intracellular ROS level, and suppressed AMPK/mTOR signaling pathway at a dose of 80 μM for 48 hr. Lentivirus-mediated short hairpin RNA targeting VDAC1 (Lv-shVDAC1) silenced VDAC1 expression and enhanced BPA-restricted cell viability. Knockdown of VDAC1 inhibited the apoptosis of BPA-treated GC-1 spg cells determined by with changes of the expressions of pro-apoptotic and anti-apoptotic proteins. Knockdown of VDAC1 also alleviated the BPA-triggered intracellular ROS generation and oxidative stress. Moreover, silence of VDAC1 increased AMPKα1/2 phosphorylation and suppressed mTOR phosphorylation under BPA exposure. Dorsomorphin, an AMPK inhibitor, partially abolished the effects of VDAC1 gene silencing on BPA-stimulated GC-1 spg cells. In conclusion, inhibition of VDAC1 attenuated the BPA-induced oxidative stress and apoptosis and promoted the cell viability in spermatogonia through modulating AMPK/mTOR signaling pathway.
双酚A（BPA）是工业产品的主要成分之一，临床上与男性不育率上升有关。然而，BPA导致生殖毒性的潜在分子机制尚未完全阐明。电压依赖性阴离子通道1（VDAC1）是一种孔蛋白，位于线粒体外膜。作为线粒体的守门人，VDAC1控制活性氧（ROS）的释放以及线粒体的代谢和能量功能，并在线粒体介导的细胞凋亡中起关键作用。在此，我们探讨了VDAC1在BPA诱导的精原细胞凋亡中的作用。结果表明，80 μM的BPA作用48小时可增加精原细胞系GC-1 spg细胞凋亡和细胞内ROS水平，并抑制AMPK/mTOR信号通路。慢病毒介导的靶向VDAC1的短发夹RNA（Lv-shVDAC1）使VDAC1表达沉默，并增强了BPA限制的细胞活力。通过检测促凋亡蛋白和抗凋亡蛋白表达的变化，发现敲低VDAC1可抑制BPA处理的GC-1 spg细胞凋亡。敲低VDAC1还可减轻BPA引发的细胞内ROS生成和氧化应激。此外，在BPA暴露条件下，沉默VDAC1可增加AMPKα1/2的磷酸化并抑制mTOR的磷酸化。AMPK抑制剂 dorsomorphin部分消除了VDAC1基因沉默对BPA刺激的GC-1 spg细胞的影响。总之，抑制VDAC1可减轻BPA诱导的氧化应激和细胞凋亡，并通过调节AMPK/mTOR信号通路促进精原细胞的细胞活力。
