Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Miaoli, 35053, Taiwan, ROC.
Institute of Molecular Medicine, National Tsing Hua University, Hsinchu, 30013, Taiwan, ROC.
Sci Rep. 2017 Jun 22;7(1):4105. doi: 10.1038/s41598-017-04203-9.
Tylophorine-based compounds exert broad spectral, potent inhibition of coronaviruses. NF-κB activation is a common pro-inflammatory response of host cells to viral infection. The aims of this study were to (i) find an effective combination treatment for coronaviral infections through targeting of the virus per se and cellular NF-κB activity; and (ii) to study the underling mechanisms. We found that tylophorine-based compounds target the TGEV viral RNA and effectively inhibit TGEV replication. NF-κB inhibition also leads to anti-TGEV replication. NF-κB activation induced by TGEV infection was found to be associated with two convergent pathways, IKK-2_IκBα/p65 and JAK2 mediated p65 phosphorylation, in swine testicular cells. JAK2 inhibition either by CYT387 (a JAK family inhibitor) or by silencing JAK2-expression revealed a dominant JAK2 mediated p65 phosphorylation pathway for NF-κB activation and resulted in NF-κB inhibition, which overrode the IκBα regulation via the IKK-2. Finally, tylophorine-based compounds work cooperatively with CYT387 to impart comprehensive anti-TGEV activities. The combination treatment, wherein a tylophorine compound targets TGEV and a JAK2 inhibitor blocks the alternative dominant NF-κB activation mediated by JAK2, is more effective and comprehensive than either one alone and constitutes a feasible approach for the treatment of SARS-CoV or MERS-CoV.
基于千里光碱的化合物对冠状病毒具有广泛的谱和强效的抑制作用。NF-κB 的激活是宿主细胞对病毒感染的一种常见的促炎反应。本研究的目的是：（i）通过靶向病毒本身和细胞 NF-κB 活性，寻找针对冠状病毒感染的有效联合治疗方法；（ii）研究潜在机制。我们发现基于千里光碱的化合物靶向 TGEV 病毒 RNA，并有效抑制 TGEV 复制。NF-κB 抑制也会导致抗 TGEV 复制。在猪睾丸细胞中，发现 TGEV 感染诱导的 NF-κB 激活与两条会聚途径有关，即 IKK-2_IκBα/p65 和 JAK2 介导的 p65 磷酸化。通过 CYT387（一种 JAK 家族抑制剂）或沉默 JAK2 表达抑制 JAK2，揭示了 JAK2 介导的 p65 磷酸化途径在 NF-κB 激活中的主导作用，并导致 NF-κB 抑制，从而克服了 IKK-2 通过 IκBα的调节。最后，基于千里光碱的化合物与 CYT387 协同作用，赋予全面的抗 TGEV 活性。联合治疗方法中，一种千里光碱化合物靶向 TGEV，而 JAK2 抑制剂阻断 JAK2 介导的替代主导 NF-κB 激活，比单独使用任何一种都更有效和全面，这为治疗 SARS-CoV 或 MERS-CoV 提供了一种可行的方法。
