stage-specific expression of tnfα regulates badbid-mediated apoptosis and rip1ros-mediated secondary necrosis in birnavirus-infected fish cellsstage-specific表达tnfα调节badbid-mediated凋亡和rip1ros-mediated二级birnavirus-infected鱼类细胞坏死.pdf

Stage-Specific Expression of TNFa Regulates Bad/Bid- Mediated Apoptosis and RIP1/ROS-Mediated Secondary Necrosis in Birnavirus-Infected Fish Cells 1,2 3 2 2 4 4 Wei-Lun Wang , Jiann-Ruey Hong , Gen-Hwa Lin , Wangta Liu , Hong-Yi Gong , Ming-Wei Lu , Ching- Chun Lin2, Jen-Leih Wu1,2* 1 Institute of Fisheries Science, National Taiwan University, Taipei, Taiwan, Republic of China, 2 Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan, Republic of China, 3 Institute of Biotechnology, National Cheng Kung University, Tainan, Taiwan, Republic of China, 4 Department of Aquaculture, National Taiwan Ocean University, Keelung, Taiwan, Republic of China Abstract Infectious pancreatic necrosis virus (IPNV) can induce Bad-mediated apoptosis followed by secondary necrosis in fish cells, but it is not known how these two types of cell death are regulated by IPNV. We found that IPNV infection can regulate Bad/ Bid-mediated apoptotic and Rip1/ROS-mediated necrotic death pathways via the up-regulation of TNFa in zebrafish ZF4 cells. Using a DNA microarray and quantitative RT-PCR analyses, two major subsets of differentially expressed genes were characterized, including the innate immune response gene TNFa and the pro-apoptotic genes Bad and Bid. In the early replication stage (0–6 h post-infection, or p.i.), we observed that the pro-inflammatory cytokine TNFa underwent a rapid six- fold induction. Then, during the early-middle replication stages (6–12 h p.i.), TNFa level was eight-fold induction and the pro-apoptotic Bcl-2 family members Bad and Bid were up-regulated. Furthermore, specific inhibitors of TNFa expression (AG-126 or TNFa-specific siRNA) were used to block apoptotic and necrotic death si