Pyridone 6 inhibits Jak3 with K(I)=5 nM; Pyridone 6 also inhibits Jak family members Tyk2 and Jak2 with IC(50)=1 nM and Jak1 with IC(50)=15 nM. Pyridone 6 was tested as an inhibitor of 21 other protein kinases; it inhibited these kinases with IC(50)s ranging from 130 nM to 10 μM[1].
Pyridone 6 strongly inhibited Th2 and modestly inhibited Th1, whereas it enhanced Th17 development when present within a certain range of concentrations. This is mostly due to strong suppression of the IFN-γ/STAT1, IL-2/STAT5, and IL-4/STAT6 signaling pathways by Pyridone 6, which all inhibit Th17 differentiation, as well as modest suppression of IL-6/STAT3, which is essential for Th17 differentiation[2,5].
In mice, Mean outward current decreased by 44% in WIF-B hepatoma cells incubated with the established hepatic differentiating factors oncostatin M/dexamethasone for 1-8 days. Pre-incubation with pyridone 6, a pan-JAK inhibitor, blocked the current reduction[3]. Pyridone 6 blocks IL2 and IL4 dependent proliferation of CTLL cells and inhibits the phosphorylation of STAT5 as measured by Western blotting[1]. Pyridone 6 is a more sensitive and specific inhibitor of JAK-STAT3 activity compared with AG490 and potently inhibited the growth of primary myeloma cells and myeloma-derived cell lines grown on BMSCs[4]. Inhibition of JAK by pyridone 6 resulted in the suppression of STAT3 phosphorylation and secretion of a subset of chemokines and JAK-activating cytokines[6]. Cytomix-induced STAT1 activation was lower and CXCR3 ligand mRNA production was more sensitive to Pyridone 6 and AG-490 in asthmatic than nonasthmatic ASMCs, but CXCL10/CXCL11 release was inhibited by the same proportion[7].
References:
[1]. Thompson JE, Cubbon RM, et,al. Photochemical preparation of a pyridone containing tetracycle: a Jak protein kinase inhibitor. Bioorg Med Chem Lett. 2002 Apr 22;12(8):1219-23. doi: 10.1016/s0960-894x(02)00106-3. PMID: 11934592
[2]. Nakagawa R, Yoshida H, et,al. Pyridone 6, a pan-JAK inhibitor, ameliorates allergic skin inflammation of NC/Nga mice via suppression of Th2 and enhancement of Th17. J Immunol. 2011 Nov 1;187(9):4611-20. doi: 10.4049/jimmunol.1100649. Epub 2011 Sep 28. PMID: 21957150.
[3]. Ogunrinde A, Pereira RD, et,al. Hepatocellular differentiation status is characterized by distinct subnuclear localization and form of the chanzyme TRPM7. Differentiation. 2017 Jul-Aug;96:15-25. doi: 10.1016/j.diff.2017.06.001. Epub 2017 Jun 12. PMID: 28609676.
[4]. Pedranzini L, Dechow T, et,al.Pyridone 6, a pan-Janus-activated kinase inhibitor, induces growth inhibition of multiple myeloma cells. Cancer Res. 2006 Oct 1;66(19):9714-21. doi: 10.1158/0008-5472.CAN-05-4280. PMID: 17018630.
[5]. Mangan PR, Harrington LE, et,al.Transforming growth factor-beta induces development of the T(H)17 lineage. Nature. 2006 May 11;441(7090):231-4. doi: 10.1038/nature04754. Epub 2006 Apr 30. PMID: 16648837.
[6]. Ohno T, Aoki H, et,al. Cytokine Profile of Human Abdominal Aortic Aneurysm: Involvement of JAK/STAT Pathway. Ann Vasc Dis. 2018 Mar 25;11(1):84-90. doi: 10.3400/avd.oa.17-00086. PMID: 29682112; PMCID: PMC5882349.
[7]. Tan X, Alrashdan YA, et,al. Airway smooth muscle CXCR3 ligand production: regulation by JAK-STAT1 and intracellular Ca2?. Am J Physiol Lung Cell Mol Physiol. 2013 Jun 1;304(11):L790-802. doi: 10.1152/ajplung.00356.2012. Epub 2013 Apr 5. PMID: 23564506.
吡啶酮 6 抑制 Jak3,K(I)=5 nM; Pyridone 6 还抑制 Jak 家族成员 Tyk2 和 Jak2,IC(50)=1 nM 和 Jak1,IC(50)=15 nM。吡啶酮 6 作为 21 种其他蛋白激酶的抑制剂进行了测试;它抑制这些激酶,IC(50) 范围为 130 nM 到 10 μM[1]。
吡啶酮 6 强烈抑制 Th2 并适度抑制 Th1,而当存在于一定浓度范围内时,它会增强 Th17 的发育。这主要是由于吡啶酮 6 对 IFN-γ/STAT1、IL-2/STAT5 和 IL-4/STAT6 信号通路的强烈抑制,它们都抑制 Th17 分化,以及对 IL-6/STAT3 的适度抑制, 这对于 Th17 的分化[2,5] 是必不可少的。
在小鼠中,WIF-B 肝癌细胞与已建立的肝分化因子制瘤素 M/地塞米松孵育 1-8 天后,平均外向电流降低了 44%。与泛 JAK 抑制剂吡啶酮 6 预孵育可阻断电流降低[3]。吡啶酮 6 阻断 CTLL 细胞的 IL2 和 IL4 依赖性增殖,并抑制 STAT5 的磷酸化,如通过蛋白质印迹法检测到的[1]。与 AG490 相比,吡啶酮 6 是一种更敏感、更特异的 JAK-STAT3 活性抑制剂,可有效抑制骨髓间充质干细胞上生长的原代骨髓瘤细胞和骨髓瘤衍生细胞系的生长[4]。吡啶酮 6 对 JAK 的抑制导致趋化因子和 JAK 激活细胞因子子集的 STAT3 磷酸化和分泌受到抑制[6]。与非哮喘 ASMC 相比,Cytomix 诱导的 STAT1 激活较低,CXCR3 配体 mRNA 生成对吡啶酮 6 和 AG-490 更敏感,但 CXCL10/CXCL11 释放受到相同比例的抑制[7]。
















