Department of Molecular and Cellular Biology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Aichi 467-8601, Japan.
J Pharmacol Exp Ther. 2010 Apr;333(1):236-43. doi: 10.1124/jpet.109.158899. Epub 2010 Jan 6.
Nuclear factor-kappaB (NF-kappaB) is involved in the pathophysiology of rheumatoid arthritis (RA) and is considered to be a feasible molecular target in treating patients. In the RA joint tissues, activation of NF-kappaB is often observed together with high amounts of the proinflammatory cytokines tumor necrosis factor (TNF)alpha and interleukin (IL)-1beta. TNFalpha and IL-1beta are known to stimulate NF-kappaB signaling and are produced as the effect of NF-kappaB signaling, thus forming a vicious cycle leading to a self-perpetuating nature of rheumatoid inflammation and expansion of such inflammatory response to other joints. Because a kinase called IkappaB kinase complex (IKK) is involved in the NF-kappaB activation cascade, we examined the effect of a novel IKK inhibitor, (7-[2-(cyclopropyl-methoxy)-6-hydroxyphenyl]-5-[(3S)-3-piperidinyl]-1,4-dihydro-2H-pyrido[2,3-d][1,3]oxazin-2-one hydrochloride; CHPD), on the production of inflammatory cytokines from rheumatoid synovial fibroblasts (RSF). TNFalpha stimulation induced production of inflammatory cytokines such as IL-6 and IL-8 in RSF, and the extent of IL-6 and IL-8 induction was dramatically reduced by CHPD under noncytotoxic concentrations. Likewise, expression of il-6 and il-8 genes was significantly reduced by CHPD. In addition, chromatin immunoprecipitation assays revealed that the DNA binding of NF-kappaB (p65) to il-8 promoter in RSF was induced after TNFalpha stimulation and that, upon CHPD treatment to RSF for 1 h, the NF-kappaB binding to il-8 promoter was significantly decreased. Here, we have demonstrated that an IKKbeta inhibitor, CHPD, acts as an effective inhibitor for the production of inflammatory cytokines in response to proinflammatory cytokines. These findings indicate that such a IKKbeta inhibitor could be a feasible candidate for an antirheumatic drug.
核因子-κB（NF-κB）参与类风湿关节炎（RA）的病理生理学，被认为是治疗患者的可行分子靶点。在 RA 关节组织中，NF-κB 的激活常与大量促炎细胞因子肿瘤坏死因子（TNF）α和白细胞介素（IL）-1β一起观察到。TNFα和 IL-1β已知可刺激 NF-κB 信号转导，并作为 NF-κB 信号转导的效应产生，从而形成一个恶性循环，导致类风湿炎症的自我持续和这种炎症反应扩展到其他关节。由于一种称为 IκB 激酶复合物（IKK）的激酶参与 NF-κB 激活级联反应，我们研究了一种新型 IKK 抑制剂（7-[2-（环丙基甲氧基）-6-羟基苯基]-5-[(3S)-3-哌啶基]-1,4-二氢-2H-吡啶并[2,3-d][1,3]恶嗪-2-酮盐酸盐；CHPD）对类风湿性滑膜成纤维细胞（RSF）产生炎性细胞因子的影响。TNFα刺激诱导 RSF 中产生炎性细胞因子，如 IL-6 和 IL-8，并且在非细胞毒性浓度下，CHPD 显著降低了 IL-6 和 IL-8 的诱导程度。同样，CHPD 显著降低了 il-6 和 il-8 基因的表达。此外，染色质免疫沉淀试验显示，在 TNFα刺激后，NF-κB（p65）与 RSF 中 il-8 启动子的 DNA 结合被诱导，并且在用 CHPD 处理 RSF 1 小时后，NF-κB 与 il-8 启动子的结合显著减少。在这里，我们已经证明 IKKβ抑制剂 CHPD 作为一种有效的抑制剂，可抑制炎性细胞因子对促炎细胞因子的反应。这些发现表明，这种 IKKβ抑制剂可能是一种可行的抗风湿药物候选物。
