Ding Li, Li Jiawei, Li Weihao, Fang Zhenhua, Li Na, Wu Shannan, Li Jiangyue, Hong Meiling
Ministry of Education Key Laboratory for Ecology of Tropical Islands, College of Life Sciences, Hainan Normal University, Haikou 571158, China.
School of Tropical Agricultural Technology, Hainan College of Vocation and Technique, Haikou, Hainan 570216, China.
J Vet Med Sci. 2018 Nov 23;80(11):1775-1781. doi: 10.1292/jvms.18-0104. Epub 2018 Sep 25.
We previously demonstrated that transmissible gastroenteritis virus (TGEV) could induce apoptosis through caspase signaling. However, apoptosis was not completely prevented by caspases inhibitors, suggesting that there may be a caspase-independent pathway involved in TGEV-induced cell apoptosis. In this study, we investigated the regulation of apoptosis-inducing factor (AIF) on TGEV-induced apoptotic pathway. Results indicated that AIF translocated from the mitochondria to nucleus during TGEV infection, and the AIF inhibitor, N-phenylmaleimide (NP), significantly attenuated the apoptosis. In addition, the translocation of AIF was inhibited by Veliparib (ABT-888), an inhibitor of poly (ADP-ribose) polymerase (PARP). And the reactive oxygen species (ROS) scavenger, pyrrolidinedithiocarbamic (PDTC), redistributed AIF in the mitochondria and nucleus in TGEV-infected cells. Moreover, the protein levels in nucleus and the mRNA levels of AIF were inhibited in the presence of the p53 inhibitor, pifithrin-α (PFT-α) or in TGEV-infected p53-/-cells. Furthermore, TGEV-induced apoptosis was blocked by combination of three or more inhibitors, such as pan caspase inhibitor Z-VAD-FMK, NP, ABT-888, PDTC, PFT-α, to treat PK-15 cells. Taken together, these results suggest that the p53- and ROS-mediated AIF pathway and caspase-dependent pathway were involved in TGEV-induced apoptosis.
我们之前证明，传染性胃肠炎病毒（TGEV）可通过半胱天冬酶信号传导诱导细胞凋亡。然而，半胱天冬酶抑制剂并不能完全阻止细胞凋亡，这表明可能存在一条不依赖半胱天冬酶的途径参与TGEV诱导的细胞凋亡。在本研究中，我们调查了凋亡诱导因子（AIF）对TGEV诱导的凋亡途径的调控作用。结果表明，在TGEV感染期间，AIF从线粒体转移至细胞核，且AIF抑制剂N-苯基马来酰亚胺（NP）可显著减轻细胞凋亡。此外，聚（ADP-核糖）聚合酶（PARP）抑制剂维利帕尼（ABT-888）可抑制AIF的转移。并且，活性氧（ROS）清除剂吡咯烷二硫代氨基甲酸盐（PDTC）可使TGEV感染细胞中的AIF在线粒体和细胞核中重新分布。此外，在存在p53抑制剂匹非尼酮-α（PFT-α）时或在TGEV感染的p53基因敲除细胞中，细胞核中的AIF蛋白水平及AIF的mRNA水平均受到抑制。此外，使用三种或更多种抑制剂（如泛半胱天冬酶抑制剂Z-VAD-FMK、NP、ABT-888、PDTC、PFT-α）联合处理PK-15细胞，可阻断TGEV诱导的细胞凋亡。综上所述，这些结果表明，p53和ROS介导的AIF途径以及半胱天冬酶依赖性途径均参与了TGEV诱导的细胞凋亡。
