Wen Danyi, Nong Yuhua, Morgan Jennifer G, Gangurde Pranoti, Bielecki Andrew, Dasilva Jennifer, Keaveney Marie, Cheng Hong, Fraser Chris, Schopf Lisa, Hepperle Michael, Harriman Geraldine, Jaffee Bruce D, Ocain Timothy D, Xu Yajun
Inflammation Department, Millennium Pharmaceuticals, Inc., 35 Landsdowne Street, Cambridge, MA 02139, USA.
J Pharmacol Exp Ther. 2006 Jun;317(3):989-1001. doi: 10.1124/jpet.105.097584. Epub 2006 Mar 8.
IkappaB kinase (IKK) beta is essential for inflammatory cytokine-induced activation of nuclear factor kappaB (NF-kappaB). NF-kappaB plays a pivotal role in the function of major cell types that contribute to the pathophysiological process of rheumatoid arthritis (RA). Here, we report the mechanism and the effect of the IKKbeta inhibitor N-(6-chloro-7-methoxy-9H-beta-carbolin-8-yl)-2-methylnicotinamide (ML120B), a beta-carboline derivative, on NF-kappaB signaling and gene activation in RA-relevant cell systems. ML120B is a potent, selective, reversible, and ATP-competitive inhibitor of IKKbeta with an IC50 of 60 nM when evaluated in an IkappaBalpha kinase complex assay. ML120B does not inhibit other IKK isoforms or a panel of other kinases. ML120B concentration-dependently inhibits tumor necrosis factor alpha (TNFalpha)-stimulated NF-kappaB signaling via inhibition of IkappaBalpha phosphorylation, degradation, and NF-kappaB translocation into the nucleus. For the first time, we have demonstrated that in human fibroblast-like synoviocytes, TNFalpha- or interleukin (IL)-1beta-induced monocyte chemoattractant protein-1 regulated on activation, normal T cell expressed and secreted and production is IKKbeta-dependent. In addition, for the first time, we have demonstrated that lipopolysaccharide- or peptidoglycan-induced cytokine production in human cord blood-derived mast cells is IKKbeta-dependent. In addition, in human chondrocytes, ML120B inhibited IL-1beta-induced matrix metalloproteinase production with an IC50 of approximately 1 microM. ML120B also blocked IL-1beta-induced prostaglandin E2 production. In summary, ML120B blocked numerous NF-kappaB-regulated cell responses that are involved in inflammation and destructive processes in the RA joint. Our findings support the evaluation of IKKbeta inhibitors as anti-inflammatory agents for the treatment of RA.
IκB激酶（IKK）β对于炎性细胞因子诱导的核因子κB（NF-κB）激活至关重要。NF-κB在促成类风湿关节炎（RA）病理生理过程的主要细胞类型的功能中起关键作用。在此，我们报告β-咔啉衍生物IKKβ抑制剂N-（6-氯-7-甲氧基-9H-β-咔啉-8-基）-2-甲基烟酰胺（ML120B）对RA相关细胞系统中NF-κB信号传导和基因激活的机制及作用。在IκBα激酶复合物测定中评估时，ML120B是一种强效、选择性、可逆且ATP竞争性的IKKβ抑制剂，IC50为60 nM。ML120B不抑制其他IKK同工型或一组其他激酶。ML120B通过抑制IκBα磷酸化、降解以及NF-κB易位至细胞核，浓度依赖性地抑制肿瘤坏死因子α（TNFα）刺激的NF-κB信号传导。我们首次证明，在人成纤维细胞样滑膜细胞中，TNFα或白细胞介素（IL）-1β诱导的单核细胞趋化蛋白-1在激活时的调节、正常T细胞表达和分泌以及产生均依赖于IKKβ。此外，我们首次证明，脂多糖或肽聚糖诱导的人脐血来源肥大细胞中的细胞因子产生依赖于IKKβ。另外，在人软骨细胞中，ML120B以约1 μM的IC50抑制IL-1β诱导的基质金属蛋白酶产生。ML120B还阻断IL-1β诱导的前列腺素E2产生。总之，ML120B阻断了众多NF-κB调节的细胞反应，这些反应参与了RA关节中的炎症和破坏过程。我们的研究结果支持将IKKβ抑制剂评估为治疗RA的抗炎药物。
