Li Na, Parrish Marcus, Chan Tze Khee, Yin Lu, Rai Prashant, Yoshiyuki Yamada, Abolhassani Nona, Tan Kong Bing, Kiraly Orsolya, Chow Vincent T K, Engelward Bevin P
Singapore-MIT Alliance for Research and Technology, 1 CREATE Way, #03-10/11 Innovation Wing, #03-12/13/14 Enterprise Wing, Singapore, 138602, Singapore.
Cell Mol Life Sci. 2015 Aug;72(15):2973-88. doi: 10.1007/s00018-015-1879-1. Epub 2015 Mar 26.
Influenza viruses account for significant morbidity worldwide. Inflammatory responses, including excessive generation of reactive oxygen and nitrogen species (RONS), mediate lung injury in severe influenza infections. However, the molecular basis of inflammation-induced lung damage is not fully understood. Here, we studied influenza H1N1 infected cells in vitro, as well as H1N1 infected mice, and we monitored molecular and cellular responses over the course of 2 weeks in vivo. We show that influenza induces DNA damage to both, when cells are directly exposed to virus in vitro (measured using the comet assay) and also when cells are exposed to virus in vivo (estimated via γH2AX foci). We show that DNA damage, as well as responses to DNA damage persist in vivo until long after virus has been cleared, at times when there are inflammation associated RONS (measured by xanthine oxidase activity and oxidative products). The frequency of lung epithelial and immune cells with increased γH2AX foci is elevated in vivo, especially for dividing cells (Ki-67-positive) exposed to oxidative stress during tissue regeneration. Additionally, we observed a significant increase in apoptotic cells as well as increased levels of DNA double strand break (DSB) repair proteins Ku70, Ku86 and Rad51 during the regenerative phase. In conclusion, results show that influenza induces DNA damage both in vitro and in vivo, and that DNA damage responses are activated, raising the possibility that DNA repair capacity may be a determining factor for tissue recovery and disease outcome.
流感病毒在全球范围内导致了严重的发病情况。炎症反应，包括活性氧和氮物种（RONS）的过度生成，在严重流感感染中介导肺损伤。然而，炎症诱导的肺损伤的分子基础尚未完全了解。在这里，我们在体外研究了甲型H1N1流感病毒感染的细胞以及甲型H1N1流感病毒感染的小鼠，并在体内监测了2周内的分子和细胞反应。我们发现，当细胞在体外直接暴露于病毒时（使用彗星试验测量）以及在体内暴露于病毒时（通过γH2AX焦点估计），流感都会导致DNA损伤。我们表明，DNA损伤以及对DNA损伤的反应在体内持续存在，直到病毒被清除很久之后，此时存在与炎症相关的RONS（通过黄嘌呤氧化酶活性和氧化产物测量）。体内肺上皮细胞和免疫细胞中γH2AX焦点增加的频率升高，特别是对于在组织再生过程中暴露于氧化应激的分裂细胞（Ki-67阳性）。此外，我们在再生阶段观察到凋亡细胞显著增加以及DNA双链断裂（DSB）修复蛋白Ku70、Ku86和Rad51水平升高。总之，结果表明流感在体外和体内均诱导DNA损伤，并且DNA损伤反应被激活，这增加了DNA修复能力可能是组织恢复和疾病结局的决定因素的可能性。
