Multi-modal rescue of pulmonary NRF2-insufficiency after burn and burn + inhalation injury to regulate innate immune dysfunction

摘要 美国烧伤协会估计，每年约有3500人死于烧伤。确实有 对烧伤患者发病率和死亡率的多种影响，其中吸入性损伤是最显著的影响之一 因为它导致对机会性细菌感染的易感性增加，以及相关的发病率和 死亡率。临床需求的三个方面与这个临床问题有关：1)我们缺乏预测疾病风险的能力 感染，2)我们不了解感染风险的机制，3)我们无法恢复患者的 免疫系统在受伤后保持动态平衡，使感染性病原体得到充分控制。总体目标 这一应用的目的是描绘导致以下失控炎症循环的机制 改进烧伤预测模型和改善治疗方法以恢复免疫力 动态平衡，从而降低对感染的敏感性，并防止相关的发病率和死亡率。 我们和其他人已经在人类样本和小鼠模型中证明了燃烧和燃烧+吸入(B+I) 损伤产生许多损伤相关分子模式(DAMP)的局部和全身释放。 阻滞剂通过关键的免疫调节因子促进相互作用，如哺乳动物雷帕霉素靶点(MTOR) 诱导活性氧(ROS)、炎性细胞因子和趋化因子，导致组织损伤 和免疫细胞募集。免疫动态平衡通常至少部分由转录因子来恢复。 核因子-红系-2相关因子(NRF2)。我们的初步数据表明Nrf2/-基因敲除小鼠 B+I损伤后死亡率极高。然而，我们的初步数据也表明，虽然肺 野生型小鼠免疫细胞NRF2蛋白翻译在B+I后迅速增加，但没有移位到 原子核。因此，我们假设烧伤和B+I损伤后NRF2介导的动态平衡是不够的， 但NRF2通路的药理激活有可能减少急性免疫功能障碍。 使用我们的烧伤和B+I损伤的临床前模型，我们将定义NRF2特定的急性免疫机制 烧伤或B+I损伤后的功能障碍，并在我们高容量的人类队列中验证这些发现 烧伤中心。此外，我们将利用微粒子技术开发和表征NRF2驱动的疗法 改善损伤后免疫功能障碍。由于我们认识到对烧伤和B+I的反应是多因素的， 我们将利用这项技术将NRF2激活与第二种方法相结合，并抑制mTOR以提供 一种新的多模式治疗方法。这些方法的有效性将使用我们的PRESS 烧伤和B+I的临床模型我们独一无二地准备成功完成这项提案，这将使 我们将致力于填补现有的知识空白，改善烧伤和B+I患者的长期预后。

SUMMARY The American Burn Association estimates that there are ~3,500 deaths each year from burn injuries. There are multiple influences on morbidity and mortality in burn patients, with inhalation injury among the most significant as it leads to increased susceptibility to opportunistic bacterial infections and the associated morbidity and mortality. A trifecta of clinical need is associated with this clinical problem: 1) we lack the ability to predict risk of infection, 2) we do not understand the mechanism of infectious risk, and 3) we are unable to restore a patient’s immune system to homeostasis after injury to enable adequate control of infectious agents. The overall objective of this application is to delineate mechanisms responsible for the cycle of uncontrolled inflammation following burn-injury to refine prediction models patient outcomes and to refine therapeutic approaches to restore immune homeostasis, thus decreasing susceptibility to infection and preventing the associated morbidity and mortality. We and others have demonstrated in human samples and mouse models that burn and burn + inhalation (B+I) injury generates the local and systemic release of numerous Damage-Associated Molecular Patterns (DAMPs). DAMPs promote interactions, via key immune regulators, such as mammalian Target of Rapamycin (mTOR) to induce reactive oxygen species (ROS), inflammatory cytokines, and chemokines which results in tissue damage and immune cell recruitment. Immune homeostasis is normally restored at least in part by the transcription factor Nuclear Factor-Erythroid-2-Related Factor (NRF2). Our preliminary data demonstrate that Nrf2-/- knockout mice have profound mortality after B+I injury. However, our preliminary data also demonstrate that while pulmonary immune cell NRF2 protein translation is rapidly increased after B+I in wildtype mice, it is not translocated to the nucleus. Thus, we hypothesize that the NRF2-mediated homeostasis following burn and B+I injury is insufficient, but that pharmacological activation of the NRF2 pathway has the potential to reduce acute immune dysfunction. Using our pre-clinical models of burn and B+I injury, we will define NRF2-specific mechanisms of acute immune dysfunction following burn or B+I injury and validate these findings in human cohorts within in our high-volume burn center. In addition, we will utilize microparticle technology to develop and characterize NRF2-driven therapy to improve post-injury immune dysfunction. As we appreciate that the response to burn and B+I is multifactorial, we will leverage this technology to combine NRF2 activation with a second approach and inhibit mTOR to provide a novel multimodal therapeutic approach. The efficacy of these approaches will be evaluated using our pre- clinical models of burn and B+I. We are uniquely poised to successful complete this proposal which will allow us to fill the existing knowledge gaps and improve long-term outcomes of burn and B+I patients.