系统性炎症反应综合征（SIRS）至少部分由激活细胞凋亡导致，其特征为危及生命的多器官功能衰竭。阻断SIRS的进展及其引发的多器官功能障碍具有挑战性。受体相互作用丝氨酸/苏氨酸蛋白激酶1（RIPK1）是细胞死亡和炎症介质的重要调节因子，在多种疾病中具有潜在的治疗靶点。本研究使用药物重定位方法，证明抑制RIPK1也是SIRS的有效治疗方法。我们对美国食品药品监督管理局批准的包含1953种药物的药物库进行基于细胞的高通量药物筛选，通过SYTOX绿染色鉴定有效的细胞凋亡抑制剂。对最佳候选药物quizartinib进行了HT-22和MEFs两个细胞系的剂量反应验证。使用免疫印迹、免疫沉淀和体外RIPK1激酶活性检测评估了quizartinib对细胞凋亡相关蛋白的作用。在小鼠肿瘤坏死因子α（TNFα）诱导的SIRS模型中评估了quizartinib的体内效应。高通量筛选鉴定出quizartinib是化合物库中挽救细胞免受体外细胞凋亡的最佳"命中"药物。Quizartinib通过直接抑制RIPK1激酶活性和阻断下游的Ⅱb复合物形成来抑制细胞凋亡。此外，quizartinib可保护小鼠免受TNFα诱导的SIRS损伤。作为已经获得FDA批准且安全有效的药物，quizartinib为针对RIPK1的靶向抑制提供了重要的临床前数据。本研究为将quizartinib转化为治疗RIPK1依赖的导致细胞凋亡的炎症性疾病，包括SIRS，提供了必要的资料。©2023美国实验生物学会。

Systemic inflammatory response syndrome (SIRS), at least in part driven by necroptosis, is characterized by life-threatening multiple organ failure. Blocking the progression of SIRS and consequent multiple organ dysfunction is challenging. Receptor-interacting serine/threonine protein kinase 1 (RIPK1) is an important cell death and inflammatory mediator, making it a potential treatment target in several diseases. Here, using a drug repurposing approach, we show that inhibiting RIPK1 is also an effective treatment for SIRS. We performed cell-based high-throughput drug screening of an US Food and Drug Administration (FDA)-approved drug library that contains 1953 drugs to identify effective inhibitors of necroptotic cell death by SYTOX green staining. Dose-response validation of the top candidate, quizartinib, was conducted in two cell lines of HT-22 and MEFs. The effect of quizartinib on necroptosis-related proteins was evaluated using western blotting, immunoprecipitation, and an in vitro RIPK1 kinase assay. The in vivo effects of quizartinib were assessed in a murine tumor necrosis factor α (TNFα)-induced SIRS model. High-throughput screening identified quizartinib as the top "hit" in the compound library that rescued cells from necroptosis in vitro. Quizartinib inhibited necroptosis by directly inhibiting RIPK1 kinase activity and blocking downstream complex IIb formation. Furthermore, quizartinib protected mice against TNFα-induced SIRS. Quizartinib, as an FDA-approved drug with proven safety and efficacy, was repurposed for targeted inhibition of RIPK1. This work provides essential preclinical data for transferring quizartinib to the treatment of RIPK1-dependent necroptosis-induced inflammatory diseases, including SIRS.© 2023 Federation of American Societies for Experimental Biology.