ADAR1调控Caspase-11非经典炎症小体激活在脓毒症急性肺损伤中的作用及机制

Acute lung injury(ALI) is a common severe disease with high fatality of 40-45%. The alveolar macrophage activated by sepsis releases a large amount of inflammatory factors, leading to uncontrolled inflammation and cell death, which is a key role in the Sepsis-induce ALI. The clinical treatment of ALI is still arduous. In this way, It possesses a crucial application value to investigate the pathogenesis and potential target for therapeutic intervention. Our preliminary data revealed that Caspase-11 deletion could decrease the LPS-induced ALI, which may be regulated by ADAR1, a important immune regulatory molecules. Synthesizing other intriguing findings，forming the basis for our central hypothesis that ADAR1 up-regulates Caspase-11 non-canonical inflammasome activation through type I interferon signaling resulting in the amplification of inflammation injury and increasing the LPS-induced ALI, While blocking the Signaling may attenuate the ALI. Our objective is to determine the effects an mechanisms of ADAR1 regulating caspase-11 signaling pathway in sepsis-induced ALI through ADAR1 and Caspase-11 gene knockout and LPS-induced ALI mice model. In this proposal, for the first time，we will validate the direct key role of Caspase-11 in the sepsis-induced ALI and the regulatory mechanism by ADAR1, which could provide a new vision for drug target designs and the specific clinical treatment strategies of sepsis induce-ALI in future

急性肺损伤是临床常见的危重症，病死率高达40-45%，脓毒症激活肺泡巨噬细胞释放大量炎症因子, 导致不可控的炎症反应和细胞死亡，成为其发病的核心环节，临床治疗非常棘手，研究其发病机制和干预靶点具有重要应用价值。我们前期研究提示Caspase-11敲除可减轻小鼠脓毒症所致肺损伤，同时发现免疫调控分子ADAR1可能对其存在调控，结合前期研究，我们提出“ADAR1通过I型干扰素上调Caspase-11非经典炎症小体焦亡，放大炎症损伤反应，加重LPS诱导的肺损伤，阻断此途径可减轻肺损伤”的假说。下一步我们拟通过ADAR1和Caspase-11基因敲除和LPS肺损伤小鼠模型，阐明ADAR1调控Caspase-11途径在脓毒症肺损伤中的重要作用及机制。本项目将首次证实Caspase-11在脓毒症肺损伤中的直接作用和ADAR1对其的调控机制，将为脓毒症急性肺损伤药物治疗靶点选择和临床治疗策略提供新视野。

急性肺损伤是临床常见的危重症，病死率高达40-45%，脓毒症激活肺泡巨噬细胞释放大量炎症因子, 导致不可控的炎症反应和细胞死亡，成为其发病的核心环节，临床治疗非常棘手，研究其发病机制和干预靶点具有重要应用价值。我们前期研究提示Caspase-11敲除可减轻小鼠脓毒症所致肺损伤，同时发现免疫调控分子ADAR1可能对其存在调控，结合前期研究，我们提出“ADAR1通过I型干扰素上调Caspase-11非经典炎症小体焦亡，放大炎症损伤反应，加重LPS诱导的肺损伤，阻断此途径可减轻肺损伤”的假说。研究中，我们使用ELISA检测了ADAR1敲减及敲减后LPS刺激后体内血清干扰素α，其他炎症因子水平以及肺炎症渗出情况。研究发现ADAR1敲减及使用LPS刺激后血清炎症因子分泌增高，肺损伤加重。使用Western blot检测发现ADAR1诱导敲除和腹腔内注射干扰素均增加小鼠肺组织Caspase-11蛋白的表达。在小鼠巨噬细胞和肺组织细胞，诱导敲除ADAR1可增加Caspase-11蛋白表达。ADAR1敲减后，小剂量LPS刺激导致体内外巨噬细胞死亡增多。脓毒症小鼠和脓毒症患者中肺组织ADAR1表达增高，提示ADAR1参与脓毒症过程。通过本项目研究证实：ADAR1与 I型干扰素形成负反馈调节，同时通过I型干扰素可上调Caspase-11依赖的非经典炎症小体焦亡途径，放大炎症损伤反应，加重LPS所致肺损伤。首次解释了ADAR1调控Caspase-11在脓毒症中的可能作用及机制，为临床脓毒症肺损伤的治疗提供了新的视野。通过项目的开展，发表了相关SCI论文多篇，资助项目参与人进行国际学习与交流2人次，国内学术会议学术交流4人次。培养硕士研究生3名。