MOE Joint International Research Laboratory of Animal Health and Food Safety, Jiangsu Foreign Expert Workshop, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China.
Viruses. 2022 Aug 15;14(8):1782. doi: 10.3390/v14081782.
DNA damage response (DDR) is an evolutionarily conserved mechanism by which eukaryotic cells sense DNA lesions caused by intrinsic and extrinsic stimuli, including virus infection. Although interactions between DNA viruses and DDR have been extensively studied, how RNA viruses, especially coronaviruses, regulate DDR remains unknown. A previous study showed that the porcine epidemic diarrhea virus (PEDV), a member of the genus in the family, induces DDR in infected cells. However, the underlying mechanism was unclear. This study showed that PEDV activates the ATM-Chk2 signaling, while inhibition of ATM or Chk2 dampens the early stage of PEDV infection. Additionally, we found that PEDV-activated ATM signaling correlates with intracellular ROS production. Interestingly, we showed that, unlike the typical γH2AX foci, PEDV infection leads to a unique γH2AX staining pattern, including phase I (nuclear ring staining), II (pan-nuclear staining), and III (co-staining with apoptotic bodies), which highly resembles the apoptosis process. Furthermore, we demonstrated that PEDV-induced H2AX phosphorylation depends on the activation of caspase-7 and caspase-activated DNAse (CAD), but not ATM-Chk2. Finally, we showed that the knockdown of H2AX attenuates PEDV replication. Taken together, we conclude that PEDV induces DDR through the ROS-ATM and caspase7-CAD-γH2AX signaling pathways to foster its early replication.
DNA 损伤反应 (DDR) 是真核细胞感知由内在和外在刺激引起的 DNA 损伤的一种进化上保守的机制，包括病毒感染。尽管已经广泛研究了 DNA 病毒与 DDR 之间的相互作用，但 RNA 病毒，特别是冠状病毒，如何调节 DDR 仍然未知。先前的一项研究表明，猪流行性腹泻病毒 (PEDV)，β冠状病毒科冠状病毒属的成员，可诱导感染细胞中的 DDR。然而，其潜在机制尚不清楚。本研究表明，PEDV 激活 ATM-Chk2 信号通路，而抑制 ATM 或 Chk2 则会抑制 PEDV 感染的早期阶段。此外，我们发现 PEDV 激活的 ATM 信号与细胞内 ROS 产生相关。有趣的是，我们发现，与典型的 γH2AX 焦点不同，PEDV 感染导致独特的 γH2AX 染色模式，包括 I 期（核环染色）、II 期（全核染色）和 III 期（与凋亡小体共染色），高度类似于凋亡过程。此外，我们证明 PEDV 诱导的 H2AX 磷酸化依赖于半胱天冬酶-7 和 caspase 激活的 DNA 酶 (CAD) 的激活，而不依赖于 ATM-Chk2。最后，我们表明 H2AX 的敲低可减弱 PEDV 的复制。总之，我们得出结论，PEDV 通过 ROS-ATM 和 caspase7-CAD-γH2AX 信号通路诱导 DDR，以促进其早期复制。
