急性肾损伤(AKI)是一种临床综合征,定义为肾功能突然下降,其特征是肾小管上皮细胞的炎症和程序性细胞死亡。坏死性凋亡是一种受调节的细胞死亡形式,需要激活受体相互作用蛋白激酶 3 (RIPK3) 及其底物 MLKL 的磷酸化。RIPK3在急性肾损伤中发挥重要作用,因此开发其抑制剂被认为是预防和治疗AKI的有希望的策略之一。最近,我们根据 RIPK3 的三维结构使用计算机辅助混合虚拟筛选策略发现了 AZD5423 作为一种新型强效 RIPK3 抑制剂。我们的研究结果表明,AZD5423 强烈抑制 RIPK3 的激活,以及顺铂后 MLKL 的磷酸化,与先前鉴定的 RIPK3 抑制剂 GSK872 相比,缺氧/复氧 (H/R)-和 TNF-α 刺激。重要的是,AZD5423 对顺铂和缺血/再灌注 (I/R) 诱导的 AKI 小鼠模型具有有效的保护作用。细胞热位移测定和RIPK3敲除细胞实验结果表明AZD5423可以直接靶向RIPK3抑制RIPK3激酶活性。机制上,AZD5423 和 RIPK3 的对接表明 RIPK3 的激酶结构域用于 Lys 细胞热位移测定和RIPK3敲除细胞实验结果表明AZD5423可以直接靶向RIPK3抑制RIPK3激酶活性。机制上,AZD5423 和 RIPK3 的对接表明 RIPK3 的激酶结构域用于 Lys 细胞热位移测定和RIPK3敲除细胞实验结果表明AZD5423可以直接靶向RIPK3抑制RIPK3激酶活性。机制上,AZD5423 和 RIPK3 的对接表明 RIPK3 的激酶结构域用于 Lys50 , Arg 313 , Lys 29 , Arg 37可能与 AZD5423 形成氢键。定点诱变进一步揭示了 AZD5423 通过与 Lys 50和 Arg 313的关键 RIPK3 氨基酸残基相互作用来降低损伤反应。总之,我们的研究表明,AZD5423 可能是一种有效的 RIPK3 激酶抑制剂,是 AKI 治疗的有希望的临床候选药物。
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RIPK3 inhibitor-AZD5423 alleviates acute kidney injury by inhibiting necroptosis and inflammation
Acute kidney injury (AKI) is a clinical syndrome that is defined as a sudden decline in renal function and characterized by inflammation and programmed cell death of renal tubular epithelial cells. Necroptosis is a form of regulated cell death that requires activation of receptor interacting protein kinase 3 (RIPK3) and its phosphorylation of the substrate MLKL. RIPK3 plays an important role in acute kidney injury, and hence developing its inhibitors is considered as one of the promising strategies aimed at prevention and treatment of AKI. Recently, we discovered AZD5423 as a novel potent RIPK3 inhibitor using a computer-aided hybrid virtual screening strategy according to three-dimensional structure of RIPK3. Our findings revealed that AZD5423 strongly inhibits activation of RIPK3, and MLKL phosphorylation upon cisplatin-, hypoxia/reoxygenation (H/R)- and TNF-α stimuli as compared with GSK872, which is a previously identified RIPK3 inhibitor. Importantly, AZD5423 exerts effective protection against cisplatin- and ischemia/reperfusion (I/R)-induced AKI mouse model. The results of cellular thermal shift assay and experiments in RIPK3 knockout cells indicated that AZD5423 could directly target RIPK3 to inhibit RIPK3 kinase activity. Mechanistically, the docking of AZD5423 and RIPK3 suggested that the kinase domain of RIPK3 for Lys50, Arg313, Lys29, Arg37 might form hydrogen bonds with AZD5423. Site-directed mutagenesis further revealed that AZD5423 reduces injury response via interacting with the key RIPK3 amino acid residues of Lys50 and Arg313. In conclusion, our study has demonstrated that AZD5423 may serve as a potent inhibitor of RIPK3 kinase and a promising clinical candidate for AKI treatment.