BC-1215, bis-pyridinyl benzyl ethanediamine, is an inhibitor of F-box only protein 3 (FBXO3) and exerts anti-inflammatory effects. BC-1215 inhibits interactions between FBXO3-F-box and the leucine rich repeat protein 2 (FBXL2), leading to the upregulation of FBXL2 expression, FBXL2-mediated ubiquitination and the degradation of tumor necrosis factor receptor (TNFR)-associated factor 6 (TRAF6) or NOD-, LRR- and the pyrin domain-containing protein 3 (NLRP3), which subsequently results in the down-regulation of inflammatory cytokine production. In the current study, we investigated the issue of whether or how BC-1215 suppresses the ATP-induced secretion of IL-1β in LPS-primed human macrophage-like cells, THP-1 cells. Our result show that pre-treatment with BC-1215 attenuated the ATP-induced secretion of IL-1β in LPS-primed THP-1 cells. Treatment of the LPS-primed THP-1 cells with BC-1215 resulted in a decrease in the level of NLRP3 and pro-IL-1β at the protein level, but not at the mRNA level. In addition, treatment with MG-132, but not leupeptin, inhibited the BC-1215-induced degradation of NLRP3 and pro-IL-1β proteins, and restored their levels, suggesting that BC-1215 decreases the stability of NLRP3 and pro-IL-1β at the protein level via proteasome-dependent degradation. Our results also show that FBXL2, which is increased by BC-1215, bound to and ubiquitinated NLRP3 and pro-IL-1β, but not pro-caspase-1. These collective results indicate that treatment with BC-1215, an inhibitor of FBXO3, inhibits ATP-induced IL-1β secretion via the FBXL2-mediated ubiquitination and degradation of pro-IL-1β as well as NLRP3 in LPS-primed THP-1 cells, suggesting that FBXO3 is a potential therapeutic target for developing agents against inflammatory diseases.

BC-1215，双吡啶基苄基乙二胺，是 F-box only protein 3 (FBXO3) 的抑制剂，具有抗炎作用。BC-1215 抑制 FBXO3-F-box 和富含亮氨酸重复蛋白 2 (FBXL2) 之间的相互作用，导致 FBXL2 表达上调、FBXL2 介导的泛素化和肿瘤坏死因子受体 (TNFR) 相关因子 6 的降解（ TRAF6) 或 NOD-、LRR- 和含有 pyrin 结构域的蛋白 3 (NLRP3)，随后导致炎症细胞因子产生的下调。在当前的研究中，我们调查了 BC-1215 是否或如何抑制 LPS 引发的人巨噬细胞样细胞 THP-1 细胞中 ATP 诱导的 IL-1β 分泌的问题。我们的结果表明，BC-1215 预处理减弱了 LPS 引发的 THP-1 细胞中 ATP 诱导的 IL-1β 分泌。用 BC-1215 处理 LPS 引发的 THP-1 细胞导致蛋白质水平的 NLRP3 和 pro-IL-1β 水平降低，但 mRNA 水平没有降低。此外，用 MG-132 而非亮肽素处理可抑制 BC-1215 诱导的 NLRP3 和 pro-IL-1β 蛋白降解，并恢复其水平，表明 BC-1215 降低了 NLRP3 和 pro-IL 的稳定性-1β 在蛋白质水平上通过蛋白酶体依赖性降解。我们的结果还表明，由 BC-1215 增加的 FBXL2 结合并泛素化 NLRP3 和 pro-IL-1β，但不结合 pro-caspase-1。这些集体结果表明，用 FBXO3 抑制剂 BC-1215 处理，通过 FBXL2 介导的 pro-IL-1β 泛素化和降解以及 LPS 引发的 THP-1 细胞中的 NLRP3，抑制 ATP 诱导的 IL-1β 分泌,