Molecular mechanisms of platelet-mediated neutrophil extracellular traps formation during acute kidney injury

急性肾损伤（阿基）是危重患者的常见并发症，与高死亡率相关。该疾病可由不同的损伤引起，包括缺血-再灌注损伤以及败血症。中性粒细胞在阿基的发病机制中起重要作用。在炎症过程中，中性粒细胞可能与血小板相互作用，这种细胞-细胞相互作用可以调节白细胞募集和中性粒细胞活化，包括中性粒细胞胞外陷阱形成和ROS产生。然而，在阿基的发展过程中血小板是否与中性粒细胞相互作用以及这种相互作用是否激活中性粒细胞并诱导NET形成仍然是未知的。此外，血小板诱导NET形成的分子机制尚不清楚。该提案的第一个目的是研究阿基期间血小板和NET形成的作用。为此，将使用两种阿基小鼠模型分析肾脏中的中性粒细胞募集和NET形成以及血小板-中性粒细胞聚集体形成。为了研究哪些分子参与这种细胞-细胞相互作用，将使用基因缺陷小鼠、阻断抗体和特异性药理学抑制剂。第二个目标关注NET降解和受损的NET形成对白细胞募集和阿基疾病进展的后果。我们将通过使用不同的试剂和基因缺陷小鼠来调节NET结构，并分析阿基期间白细胞募集到肾脏中的不同步骤。为此，将使用肾脏活体显微镜和一种新的基于流式细胞术的方法。本论文的结果将有助于为阿基患者的未来临床治疗策略确定新的治疗方向。

Acute kidney injury (AKI) is a common complication in critically ill patients and is associated with a high mortality. The disease can be caused by different insults including ischemia-reperfusion injury as well as sepsis. Neutrophils play an important role in the pathogenesis of AKI. Neutrophils may interact with platelets during inflammation and this cell-cell interaction can modulate leukocyte recruitment and neutrophil activation including neutrophil extracellular trap formation and ROS production. However, it is still unknown whether platelets interact with neutrophils during the development of AKI and whether this interaction activates neutrophils and induces NET formation. Furthermore, the molecular mechanisms of platelet-induced NET formation are unclear. The first aim of this proposal is to investigate the role of platelets and NET formation during AKI. For this purpose, two mouse models of AKI will be used to analyze neutrophil recruitment and NET formation in the kidney as well as platelet-neutrophil aggregate formation. To investigate which molecules are involved in this cell-cell interaction, gene-deficient mice, blocking antibodies and specific pharmacological inhibitors will be used. The second aim focuses on the consequences of NET degradation and impaired NET formation for leukocyte recruitment and disease progression of AKI. We will modulate NET structures by using different reagents and gene-deficient mice and analyze the different steps of leukocyte recruitment into the kidney during AKI. For this, intravital microscopy of the kidney and a new flow-cytometry based method will be used. The results from theses proposal will help to identify new therapeutic directions for future clinical treatment strategies for patients with AKI.