Inflammasome activation in trauma-hemorrhagic shock

项目概要/摘要 控制炎症和细胞损伤是预防和治疗多器官衰竭的关键 （MOF）创伤后。然而，许多调节炎症和细胞死亡的机制 具体器官仍不清楚。因此，尽管 MOF 患者的支持治疗取得了进展，但 MOF 治疗或我们充分预防 MOF 发病的能力方面进展甚微。我们的总体目标是 最终为创伤患者开发基于调节炎症反应的新疗法 对创伤和失血性休克复苏后细胞死亡的影响（HS/R）。在这个提案中我们 将继续研究 caspase-4（人）/11（小鼠）的下游细胞和组织特异性作用 HS/R 后激活。我们还将评估新型 caspase-4/11 抑制剂降低 HS/R- 的能力 对全身炎症、细胞死亡和终末器官损伤的介导作用。了解多重影响 caspase-11 对炎症和器官损伤的影响将使我们能够评估 caspase-11 的转化潜力 靶向 caspase-11 抑制可改善创伤和出血后患者的预后。 这项资助的最新工作定义了一种新的 caspase-4/11 激活机制（非 创伤/HS/R 中的典型炎症小体）。 Caspase-4/11 是脂多糖的细胞内受体 (LPS) 是感染和败血症期间炎症的重要介质。我们的工作表明激活 caspase-4/11 在非 LPS 驱动的炎症模型中，我们定义了一种新的激活机制 caspase-11 由应激线粒体外部的内源性氧化心磷脂 (CLox) 激活。 CLox 是 受细胞色素 c 调节，特异性抑制细胞色素 c 可抑制 caspase-11 激活，且高度 HS/R 小鼠模型中的器官保护作用。然而，半胱天冬酶有害作用的机制基础是 HS/R 中的 11 激活尚不清楚，鉴于其多种细胞特异性炎症，可能是多因素的 效应，包括诱导细胞焦亡（炎症细胞死亡）、炎症 HMGB1 的主动释放 HS/R 后肝细胞中的细胞外囊泡 (EV)，以及最近描述的对凝血的影响 通过增强脓毒症中组织因子 (TF) 与内皮细胞 (EC) 的结合。因此，我们主要 假设认为 caspase-4/11 激活在 HS/R 过程中通过多种细胞特异性作用是有害的 影响。在本提案中，我们将： 1：确定 caspase-4/11 介导的炎症对器官的作用 HS/R 期间受伤； 2：确定caspase-4/11-激活对凝血和器官损伤的影响 在 HS/R 期间； 3：确定小鼠模型中 caspase-11 特异性抑制的安全性和有效性 HS/R。我们期望在 HS/R 中显示 caspase-4/11 的特异性抑制具有器官保护作用，并且 保护机制是多因素的。我们还期望证明 caspase-4/11 的抑制是一种有吸引力的 治疗目标是减少创伤引起的炎症、凝血障碍和器官损伤。

PROJECT SUMMARY/ABSTRACT Controlling inflammation and cellular damage is key to preventing and treating multiple organ failure (MOF) following trauma. However, many of the mechanisms that regulate inflammation and cell death in specific organs remain unknown. So despite advances in supportive care for MOF patients, there have been few advances in MOF treatments, or in our ability to adequately prevent MOF onset. Our overarching goal is to ultimately develop new therapeutics for trauma patients based on regulating inflammatory responses and effects on cell death following trauma and hemorrhagic shock with resuscitation (HS/R). In this proposal we will continue to investigate downstream cell and tissue-specific effects of caspase-4 (human)/11 (mouse) activation after HS/R. We will also assess the ability of a novel caspase-4/11 inhibitor to reduce HS/R- mediated effects on systemic inflammation, cell death and end-organ injury. Understanding the multiple effects of caspase-11 on inflammation and organ damage will enable us to assess the translational potential of targeted caspase-11-inhibition for improved patient outcomes after trauma and hemorrhage. The most recent work on this grant defined a novel mechanism of caspase-4/11 activation (non- canonical inflammasome) in trauma/HS/R. Caspase-4/11 is the intracellular receptor for lipopolysaccharide (LPS) and is an important mediator of inflammation during infection and sepsis. Our work showed activation of caspase-4/11 in non-LPS-driven models of inflammation, and we defined a novel mechanism of activation of caspase-11 by endogenous oxidized cardiolipin (CLox) on the outside of stressed mitochondria. CLox is regulated by cytochrome c, and specific inhibition of cytochrome c inhibits caspase-11 activation and is highly organ protective in a mouse model of HS/R. However, the mechanistic basis of detrimental effects of caspase- 11 activation in HS/R are not clear, and may be multifactorial given its multiple cell-specific inflammatory effects, including induction of pyroptosis (inflammatory cell death), active release of inflammatory HMGB1 in extracellular vesicles (EV) from hepatocytes after HS/R, and more recently-described effects on coagulation through enhanced binding of tissue factor (TF) on endothelial cells (EC) in sepsis. Therefore, our main hypothesis is that caspase-4/11 activation is detrimental during HS/R through multiple cell-specific effects. In this proposal we will: 1: determine the role of caspase-4/11-mediated inflammation on organ injury during HS/R; 2: determine the effects of caspase-4/11-activation on coagulation and organ injury during HS/R; 3: determine safety and effectiveness of caspase-11-specific inhibition in mouse models of HS/R. We expect to show specific inhibition of caspase-4/11 in HS/R is organ protective and the mechanisms of protection are multi-factorial. We also expect to show inhibition of caspase-4/11 is an attractive therapeutic target to reduce trauma-induced inflammation, coagulopathy and organ damage.