Pyridone 6 (JAK Inhibitor)(CMP 6) is a potent and selective inhibitor of JAK1 (IC50=15 nM, murine JAK1), JAK2 (IC50=1 nM), JAK3 (Ki=5 nM), and Tyk2 (IC50=1 nM); displaying significantly weaker affinities (130 nM to 10 mM) for other protein tyrosine kinases.

JAK1:15 nM, JAK3:5 nM(Ki), TYK2:1 nM, JAK2:1 nM

Pyridone 6（P6）通过与每个JAK的ATP结合沟槽内相互作用，显示出抑制激酶的能力。Pyridone 6对这些细胞因子的IC50为3 nM，与Pyridone 6对JAK2、Tyk2和JAK3的报告IC50相当。Pyridone 6强烈抑制Th2，并适度抑制Th1，而在一定浓度范围内则促进Th17的发展。Pyridone 6降低IFN-γ和IL-13的表达，同时增加IL-17和IL-22的表达。在一定浓度范围内，Pyridone 6还抑制Th1和Th2的发展，同时促进从幼稚T细胞到Th17的分化[1]。Pyridone 6在用核因子-k B（NF-k B）受体活化剂配体（RANKL）刺激和骨髓细胞与成骨细胞共培养的小鼠骨髓巨噬细胞（BMM）文化中，抑制破骨细胞的分化。Pyridone 6抑制BMM中的c-Fos和活化T细胞的核因子（NFAT）c1的表达。同时，Pyridone 6还抑制成熟破骨细胞中的I-k B降解和胞外信号调节激酶（ERK），表明这些是Pyridone 6在抑制破骨细胞功能中针对的关键分子[2]。Pyridone 6（P6）被发现在低nM范围内（IC50，1-15 nM）抑制JAKs，并阻断依赖于IL-2的CTLL细胞增殖。Pyridone 6是一种可逆的ATP抑制剂，在针对许多其他激酶的测试中，需要IC50s>130 nM[3]。

Pyridone 6 (P6) 在NC/Nga小鼠的AD样皮肤病模型中延缓起病并减轻疾病程度。P6-nano显著改善NC/Nga小鼠的异位性皮炎(AD)，其效果可与常用化合物——倍他米松软膏相媲美，后者亦作为阳性对照进行测试。相反，空的PLGA纳米粒子(C-nano)似乎无效[1]。

Kinase Assays: Baculovirus-expressed glutathione S-transferase-tagged proteins encoding the intracellular domain of IGF-1R (amino acids 957-1367) and IR (amino acids 979-1382) are used for determinations of IC50s by a homogeneous time-resolved fluorescence assay. A filter binding assay is used for appKi determinations using activated IGF-1R and IR kinases. Expanded kinase-selectivity profiling of GSK1838705A is carried out by screening the compound in the KinaseProfiler panel.

Pyridone 6 (P6) is prepared in DMSO and stored, and then diluted with appropriate medium before use[1]. Naive CD4+ T cells are treated with various concentrations of Pyridone 6 in RPMI 1640 medium 1 h before the appropriate cytokines are added to create each Th-differentiating condition. Immunoblotting is performed using antiphospho-STAT protein Abs or anti-total STAT protein Abs[1].