ALK通过AKT/NF-κB通路调控巨噬细胞极化在脓毒性急性肾损伤中的机制研究

Septic acute kidney injury (SAKI) is a common disease in critically ill patients with high mortality. Macrophage polarization plays an important role in SAKI, but the specific mechanism is unclear. Our previous work observed the abnormally increased expression of transmembrane receptor ALK in monocytes of SAKI patients. Moreover, we found the AKT/NF-κB pathway involved in macrophage polarization was also significantly activated. It is speculated that "ALK can activate NF-κB pathway by phosphorylating AKT, thereby regulating macrophage polarization and promoting the occurrence and progress of SAKI". This study will 1) demonstrate the correlation between ALK and SAKI through clinical sample detection and retrospective data analysis; 2) establish cecal ligation and puncture (CLP) model with Alk gene knockout mice to explore the role of ALK in regulating macrophage polarization and SAKI; 3) use gene and protein intervention technique in vitro cell model to elucidate the molecular mechanism of ALK/AKT/NF-κB pathway and its regulation on macrophage polarization. This study will provide clues for understanding the pathophysiological mechanism of SAKI and find new therapeutic targets.

脓毒性急性肾损伤（SAKI）是危重症患者常见疾病，死亡率极高，巨噬细胞极化在其中起重要作用，但具体机制未明。申请人前期研究发现，SAKI患者外周血单个核细胞中的间变性淋巴瘤激酶（ALK）表达异常增高，进一步研究发现参与巨噬细胞极化的AKT/NF-κB通路也被显著激活。我们推测ALK可以通过磷酸化AKT激活NF-κB通路，调控巨噬细胞极化，进而促进脓毒性肾损伤的发生和进展。本项目拟：1）通过临床样本检测和回顾性分析，明确ALK与SAKI的相关性；2）建立基因敲除小鼠的盲肠结扎穿孔（CLP）模型，探索ALK调控巨噬细胞极化在SAKI中的作用；3）在体外细胞模型中，通过基因和蛋白干预技术阐明ALK通过AKT/NF-κB通路调控巨噬细胞极化的分子机制。本项目的研究将为解析脓毒性肾损伤的病理生理机制以及寻找新的治疗靶点提供线索。

脓毒症是危重症患者急性肾损伤常见的病因，死亡率极高，巨噬细胞极化在机体感染后免疫激活导致的器官损伤起重要作用，但具体机制未明。本研究发现，脓毒性患者外周血单个核细胞中的间变性淋巴瘤激酶（ALK）表达异常增高，进一步研究发现参与巨噬细胞极化的AKT/NF-κB通路也被显著激活。脓毒症患者表现出与NF-kB信号通路相关的间变性淋巴瘤激酶基因ALK呈高甲基化，同时，使用DNA甲基转移酶抑制剂可以抑制NF-κB信号活化，下调炎症细胞因子水平，改善脓毒症后T细胞抑制情况，减轻疾病进展并提高生存率。AKL敲除小鼠或可通过调节肾脏组织中巨噬细胞极化，减轻脓毒症肾损伤。因此，ALK可能是脓毒性免疫调节的重要因子，作为脓毒症干预的新靶点。