Effects of Sleep Deprivation on Infection Induced Organ Failure

描述（由申请人提供）：最近的研究表明，危重患者睡眠质量差，经常中断，昼夜节律丧失，恢复阶段睡眠时间百分比明显减少。重要的是，这些患者的睡眠剥夺可能会产生不良后果。与这一概念一致，最近的两项动物研究发现，睡眠剥夺明显增加败血症的死亡率，但造成这一现象的机制尚不清楚。我们将测试特定的假设，即睡眠剥夺与感染相互作用，激活内质网（ER）应激途径，而内质网应激途径的激活，反过来，导致多个器官的衰竭。目的1将确定感染和睡眠剥夺是否在多个组织中协同诱导内质网应激，以及内质网应激途径激活是否会导致器官衰竭。研究将使用脓毒症（盲肠结扎和穿刺，CLP）和睡眠剥夺（SD）动物模型进行。实验1.1将验证脓毒症和睡眠剥夺相互作用诱导内质网应激的假设，内质网应激通路的激活与器官衰竭的发生并行。实验1.2将验证内质网应激的化学激活引发病理改变（如下游蛋白水解途径的激活）从而导致器官功能障碍的假设。目的2将阐明脓毒症和睡眠剥夺激活内质网应激途径的上游机制。实验2.1将验证细胞因子诱导的活性氧（ROS）的产生是脓毒症中激活内质网应激的关键上游触发因素的假设。实验2.2将验证外周组织时钟基因功能上游改变激活内质网应激通路以应对睡眠剥夺的假设。实验2.3将验证外周组织时钟功能的破坏增加ROS生成并激活内质网应激途径的假设。目的3将确定内质网应激途径的药理学抑制剂是否能改善败血症和睡眠剥夺患者的器官功能。实验3.1、3.2和3.3将检验假设z-

DESCRIPTION (provided by applicant): Recent studies indicate that critically ill patients experience poor sleep, frequent disruptions, loss of circadian rhythm and a marked reduction of the percentage of sleep time spent in restorative stages. Importantly, sleep deprivation in these patients may have adverse consequences. In keeping with this concept, two recent animal studies found that sleep deprivation markedly increases death in sepsis, but the mechanisms responsible for this phenomenon are completely unknown. We will test the specific hypotheses that sleep deprivation interacts with infection to activate endoplasmic reticulum (ER) stress pathways and that ER stress pathway activation, in turn, causes failure of multiple organs. Aim 1 will determine if infection and sleep deprivation synergistically induce ER stress in multiple tissues and if ER stress pathway activation produces organ failure. Studies will be performed using animal models of sepsis (cecal ligation and puncture, CLP) and sleep deprivation (SD). Experiment 1.1 will test the hypothesis that sepsis and sleep deprivation interact to induce ER stress, with ER stress pathways activated in parallel with development of organ failure. Experiment 1.2 will test the hypothesis that chemical activation of ER stress triggers pathological alterations (e.g. activation of downstream proteolytic pathways) that produce organ dysfunction. Aim 2 will elucidate the upstream mechanisms by which sepsis and sleep deprivation activate ER stress pathways. Experiment 2.1 will test the hypothesis that cytokine-induced production of reactive oxygen species (ROS) is the key upstream trigger that activates ER stress in sepsis. Experiment 2.2 will test the hypothesis that upstream alterations in peripheral tissue clock gene function activate ER stress pathways in response to sleep deprivation. Experiment 2.3 will test the hypothesis that disruption of peripheral tissue clock function increases ROS generation, and activates ER stress pathways. Aim 3 will determine if administration of pharmacological inhibitors of ER stress pathways improves organ function in sepsis and sleep deprivation. Experiments 3.1, 3.2, and 3.3 will test the hypothesis that either z- ATAD-fmk (a caspase 12 inhibitor), salubrinal (a selective inhibitor of eIF2¿ dephosphorylation), or melatonin (an endogenous hormone that inhibits the IRE1¿ pathway) will block ER stress pathway dependent cell damage and improve organ function in CLP+SD. Experiment 3.4 will test the hypothesis that delayed administration of the pharmacologic agent to found to produce the best therapeutic effect will block ER stress pathway dependent cell damage and improve organ function in CLP+SD.