Chemical and Biological Integrative Research Center, Biomedical Research Division, Korea Institute of Science and Technology, Seoul 02792, Korea.
Division of Bio-Medical Science & Technology, KIST School, Korea University of Science and Technology, Seoul 02792, Korea.
Molecules. 2022 Apr 11;27(8):2458. doi: 10.3390/molecules27082458.
Recognition of intracellular lipopolysaccharide (LPS) by Caspase-4 (Casp-4) is critical for host defense against Gram-negative pathogens. LPS binds to the N-terminal caspase activation and recruitment domain (CARD) of procaspase-4, leading to auto-proteolytic activation followed by pro-inflammatory cytokine release and pyroptotic cell death. Aberrant hyper-activation of Casp-4 leads to amplification of the inflammatory response linked to sepsis. While the active site of a caspase has been targeted with peptide inhibitors, inhibition of LPS-Casp-4 interaction is an emerging strategy for the development of selective inhibitors with a new mode of action for treating infectious diseases and sepsis induced by LPS. In this study, a high-throughput screening (HTS) system based on fluorescence polarization (FP) was devised to identify inhibitors of the LPS and Casp-4 interaction. Using HTS and IC determination and subsequently showing inhibited Casp-4 activity, we demonstrated that the LPS-Casp-4 interaction is a druggable target for Casp-4 inhibition and possibly a non-canonical inflammatory pathway.
细胞内脂多糖 (LPS) 被 Caspase-4 (Casp-4) 识别对宿主防御革兰氏阴性病原体至关重要。LPS 与前 Caspase-4 的 N 端 Caspase 激活和募集结构域 (CARD) 结合，导致自身蛋白水解激活，随后释放促炎细胞因子并发生细胞焦亡。Casp-4 的异常过度激活会导致与败血症相关的炎症反应放大。虽然已经针对半胱天冬酶的活性位点进行了肽抑制剂的靶向研究，但抑制 LPS-Casp-4 相互作用是开发具有新型作用机制的选择性抑制剂的新兴策略，可用于治疗由 LPS 引起的传染病和败血症。在这项研究中，设计了一种基于荧光偏振 (FP) 的高通量筛选 (HTS) 系统来鉴定 LPS 和 Casp-4 相互作用的抑制剂。通过 HTS 和 IC 测定，并随后显示抑制 Casp-4 活性，我们证明 LPS-Casp-4 相互作用是 Casp-4 抑制的可药物靶标，并且可能是一种非经典炎症途径。
