Identification of a Potent Janus Kinase 3 Inhibitor with High Selectivity within the Janus Kinase Family
摘要:
We describe a synthetic approach toward the rapid modification of phenyl-indolyl maleimides and the discovery of potent Jak3 inhibitor 1 with high selectivity within the Jak kinase family We provide a rationale for this unprecedented selectivity based on the X-ray crystal structure of an analogue of 1 bound to the ATP-binding site of Jak3 While equally potent compared to the Pfizer pan Jak inhibitor CP-690,550 (2) in an enzymatic Jak3 assay, compound 1 was found to be 20 fold less potent in cellular assays measuring cytokine-triggered signaling through cytokine receptors containing the common gamma chain (gamma C) Contrary to compound 1, compound 2 inhibited Jak1 in addition to Jak3 Permeability and cellular concentrations of compounds 1 and 2 were similar As Jak3 always cooperates with Jak 1 for signaling, we speculate that specific inhibition of Jak3 is not sufficient to efficiently block gamma C cytokine signal transduction required for strong immunosuppression
JAK家族激酶是免疫细胞信号传导的重要介体,Janus激酶3(JAK3)长期以来一直被视为自身免疫性疾病的潜在靶标。开发高选择性JAK3抑制剂的努力已经很多年了。但是,由于JAK3对5'-三磷酸腺苷(ATP)的强烈结合偏好,许多抑制剂在酶和细胞效能之间显示出较大的差距,这阻碍了剖析JAK3在细胞环境中的作用。使用靶向共价抑制剂方法,我们发现了化合物32,该化合物克服了酶促测定中的ATP竞争(1 mM),并证明了对小鼠CTLL-2和人外周血单核细胞中JAK3依赖性信号传导的抑制活性显着提高。化合物32在JAK家族中还显示出高选择性和良好的药代动力学特性。因此,它可能是一种非常有价值的工具分子,用于研究JAK家族激酶在复杂生物学环境中的重叠作用。我们的研究还表明,对于共价激酶抑制剂,尤其是那些针对具有低K m ATP值的激酶的抑制剂,应仔细优化分子与蛋白质之间的可逆相互作用,以提高整体效能。
The present invention relates to a compound of Formula (I)/(II) or pharmaceutically acceptable salts thereof. In Formula (I), Rh, Rg, Rf, m, Re, Rd, Ra, Rb, and Rc are as defined in the description. The present invention further relates to a pharmaceutical composition comprising the compound of Formula (I)/(II) or pharmaceutically acceptable salts thereof, and use of the compound of Formula (I)/(II) or the pharmaceutical composition in the manufacture of a medicament for treating inflammations such as rheumatoid arthritis.