Mechanistic evaluation of the role of circadian rhythms in acute lung injury and subsequent recovery

项目摘要 我们的总体目标是确定急性肺损伤的昼夜节律调节机制 以及随后的恢复。我们发表的研究表明，昼夜节律赋予一天中特定的时间， 保护免受甲型流感病毒（IAV）感染。在黎明时感染的小鼠的存活率是在黎明时感染的小鼠的3倍， 在黄昏时感染虽然我们不能在临床上控制暴露于IAV的时间，但这些数据表明， 改变宿主的昼夜健康可能会影响结果。事实上，从基因上扰乱昼夜节律 在小鼠中，通过删除核心时钟基因Bmal 1，IAV的死亡率恶化。进一步证明了平移 我们的机械工作的相关性来自我们对英国生物库的分析，该分析显示， 昼夜节律是流感相关住院的独立危险因素。重度流感 感染的特征在于广泛的免疫病理学和发育不良的肺修复和再生，通常 与病毒负荷无关。疫苗和抗病毒剂的效力都有限。现时的建议 通过探索一个新的目标-昼夜节律作为结果的决定因素， IAV自上次提交以来，我们已经生成了令人兴奋的初步数据，表明 AT 2时钟与（a）更严重的急性死亡率、免疫病理学和坏死性凋亡相关，以及（B） 体内恢复延迟和类器官测定中再生不良。我们的总体目标是： (1)测试AT 2时钟的中断导致促炎状态的假设， IAV感染进一步加重了基线，从而加重了坏死性凋亡。 (2)为了验证生物钟通过Wnt-1促进肺再生的假设， 通过Axin 2+上皮小生境对细胞周期进行响应性调节。 我们的方法采用组织特异性昼夜节律敲除模型诱导成年，昼夜节律采样 在整个24小时内，昼夜节律中断的其他遗传/环境模型和工具形成肺再生 生物学，根据昼夜节律定制。我还召集了一个优秀的合作者团队， 拥有细胞死亡、昼夜生物信息学、肺再生和病毒学专业知识的顾问。阐明 这些机制是调节宿主昼夜节律的关键下一步， 目的虽然我们使用流感作为我们的模型，但由此揭示的原理应该是可推广的， 其他肺部病毒性疾病。

Project Summary Our overall aim is to define the mechanisms underlying the circadian regulation of acute lung injury and subsequent recovery. Our published work shows that circadian rhythms confer a time of day specific protection from Influenza A Virus (IAV) infection. Mice infected at dawn had 3-fold better survival than those infected at dusk. While, we cannot clinically control the time of exposure to IAV, these data suggest that altering the circadian health of the host could affect outcomes. In fact, disrupting circadian rhythms genetically in mice, by deleting the core clock gene, Bmal1, worsened mortality from IAV. Further proof of the translational relevance of our mechanistic work came from our analyses of the UK biobank which revealed that disrupted circadian rhythms was an independent risk factor for Influenza related hospitalization. Severe influenza infection is characterized by extensive immunopathology and dysplastic lung repair and regeneration, often independent of viral burden. Both vaccines and anti-viral agents have limited efficacy. The current proposal addresses this need in the field by exploring a novel target—circadian rhythms as determinant of outcomes in IAV. Since the last submission, we have generated exciting preliminary data that shows that disruption of the AT2 clock is associated with (a) worse acute mortality, immunopathology and necroptosis and (b) delayed recovery in vivo and poor regeneration on organoid assays. Our overall goals are to: (1) Test the hypothesis that the disruption of the AT2 clock leads to a pro-inflammatory state at baseline that is further exacerbated by IAV infection, thereby worsening necroptosis. (2) To test the hypothesis that the circadian clock contributes to lung regeneration through Wnt- responsive regulation of the cell cycle via the Axin2+ epithelial niche. Our approach employs tissue specific circadian knock-out models induced in adulthood, circadian sampling throughout 24hrs, other genetic/environmental models of circadian disruption and tools form lung regenerative biology, customized to the circadian context. I have also gathered an outstanding team of collaborators and consultants with expertise in cell death, circadian bioinformatics, lung regeneration and virology. Elucidating these mechanisms is the critical next step towards modulating the host circadian rhythms for therapeutic purposes. While, we use influenza as our model, the principles uncovered thus, should be generalizable to other viral conditions of the lung.