Targeting Myeloid Dependent MicroRNAs in Acute Respiratory Distress Syndrome

摘要 肺部炎症是导致急性呼吸窘迫综合征(ARDS)的重要因素之一。这个 感染或组织损伤后的初始急性肺炎症导致白细胞的深度渗透 以及炎性细胞因子的释放。髓系细胞，包括巨噬细胞，是调节 急性肺部炎症的发病和消退。然而，将巨噬细胞重新编程为 控制过度炎症仍不完全清楚。最近的研究表明， 炎症性疾病中的microRNAs(MiRNAs)。然而，几乎没有做过什么研究来评估 巨噬细胞中miRNAs在控制肺部炎症中的功能作用。我们假设 肺部炎症的控制涉及巨噬细胞中特定miRNAs的转录诱导。我们的 研究发现，在新招募的巨噬细胞中，microRNA-147(miR-147)显著增加 肺部发炎。MiR-147的诱导依赖于缺氧诱导因子1A。在功能上，miR- 147在体外控制巨噬细胞炎症，髓系来源的miR-147抑制肺 体内的炎症。我们鉴定并确认了线粒体复合体相关蛋白 NDUFA4作为MIR-147的主要目标。新的和令人兴奋的初步数据表明，通过定向 NDUFA4、miR-147抑制炎性细胞因子IL-6、IL-1β和肿瘤坏死因子α的产生 巨噬细胞。更多的证据支持抑制琥珀酸氧化和伴随的 组蛋白高甲基化参与了miR-147/NDUFA4介导的效应。最后，过度表达 MIR-147可促进体内肺部炎症的恢复。在这里，我们测试假设，即mir- 147/NDUFA4轴是巨噬细胞控制肺部炎症的内源性保护途径。 为了检验这一假设，人们提出了以下三个目标。在目标1中，我们将使用最先进的miR- 147只报告小鼠，研究miR-147的转录调控，并研究miR-147是如何- 147/NDUFA4轴在体外控制巨噬细胞炎症。在目标2中，我们将执行原则证明 在人ARDS中的研究和利用尖端转基因小鼠来探讨其功能作用 巨噬细胞在体内肺部炎症过程中的MIR-147/NDUFA4轴在目标3中，我们将进一步探索 MiR-147/NDUFA4轴在调节肺部炎症中的治疗靶向性该计划的完成 拟议的研究将确定miRNA靶点作为ARDS的一种创新治疗方法。

Abstract Lung inflammation is one of the profound contributors to acute respiratory distress syndrome (ARDS). The initial acute lung inflammation in response to infection or tissue injury leads to profound infiltration of leukocytes and the release of inflammatory cytokines. Myeloid cells, including macrophages, are key players mediating the onset and resolution of acute lung inflammation. However, the triggers that reprogram macrophages to control excessive inflammation remain incompletely understood. Recent work has demonstrated a key role for microRNAs (miRNAs) in inflammatory diseases. However, little research has been done to assess the functional role of miRNAs in macrophages in the context of controlling lung inflammation. We hypothesize that control of lung inflammation involves the transcriptional induction of specific miRNAs in macrophages. Our study has identified microRNA-147 (miR-147) to be dramatically increased in recruited macrophages during lung inflammation. The induction of miR-147 is dependent on hypoxia-inducible factor 1A. Functionally, miR- 147 controls macrophage inflammation in vitro, and myeloid-derived miR-147 dampens lung inflammation in vivo. We identified and confirmed the mitochondria complex associated protein NDUFA4 as a leading miR-147 target. New and exciting preliminary data indicated that by targeting NDUFA4, miR-147 dampens the production of inflammatory cytokines such as IL-6, IL-1β, and TNFα in macrophages. Additional evidence supports that inhibition of succinate oxidation and concomitant histone hypermethylation contributes to the miR-147/NDUFA4 mediated effect. Finally, overexpression of miR-147 improves the recovery from lung inflammation in vivo. Here, we test the hypothesis that the miR- 147/NDUFA4 axis represents an endogenous protective pathway in macrophages to control lung inflammation. The following three aims have been proposed to test this hypothesis. In Aim 1, we will use state-of-art miR- 147 reporter mice to study the transcriptional regulation of miR-147 and investigate how miR- 147/NDUFA4 axis controls macrophage inflammation in vitro. In Aim 2, we will perform proof-of-principle studies in human ARDS and employ cutting-edge transgenic mice to investigate the functional role of miR-147/NDUFA4 axis in macrophages during lung inflammation in vivo. In Aim 3, we will further explore the therapeutic targeting of miR-147/NDUFA4 axis in modulating lung inflammation. The completion of the proposed study will identify miRNA targets as an innovative therapeutic approach for ARDS.