Su Ai-Rong, Qiu Min, Li Yan-Lei, Xu Wen-Tao, Song Si-Wei, Wang Xiao-Hui, Song Hong-Yong, Zheng Nan, Wu Zhi-Wei
Center for Public Health Research, Medical School.
Y-Clone Biomedical Technologies, Ltd, Suzhou 215028, China.
Acta Pharmacol Sin. 2017 Mar;38(3):402-414. doi: 10.1038/aps.2016.160. Epub 2017 Jan 23.
BX-795 is an inhibitor of 3-phosphoinositide-dependent kinase 1 (PDK1), but also a potent inhibitor of the IKK-related kinase, TANKbinding kinase 1 (TBK1) and IKKɛ. In this study we attempted to elucidate the molecular mechanism(s) underlying the inhibition of BX-795 on Herpes simplex virus (HSV) replication. HEC-1-A or Vero cells were treated with BX-795 and infected with HSV-1 or HSV-2 for different periods. BX-795 (3.125-25 μmol/L) dose-dependently suppressed HSV-2 replication, and displayed a low cytotoxicity to the host cells. BX-795 treatment dose-dependently suppressed the expression of two HSV immediate-early (IE) genes (ICP0 and ICP27) and the late gene (gD) at 12 h postinfection. HSV-2 infection resulted in the activation of PI3K and Akt in the host cells, and BX-795 treatment inhibited HSV-2-induced Akt phosphorylation and activation. However, the blockage of PI3K/Akt/mTOR with LY294002 and rapamycin did not affect HSV-2 replication. HSV-2 infection increased the phosphorylation of JNK and p38, and reduced ERK phosphorylation at 8 h postinfection in the host cells; BX-795 treatment inhibited HSV-2-induced activation of JNK and p38 MAP kinase as well as the phosphorylation of c-Jun and ATF-2, the downstream targets of JNK and p38 MAP kinase. Furthermore, SB203580 (a p38 inhibitor) or SP600125 (a JNK inhibitor) dose-dependently inhibited the viral replication in the host cells, whereas PD98059 (an ERK inhibitor) was not effective. Moreover, BX-795 blocked PMA-stimulated c-Jun activation as well as HSV-2-mediated c-Jun nuclear translocation. BX-795 dose-dependently inhibited HSV-2, PMA, TNF-α-stimulated AP-1 activation, but not HSV-induced NF-κB activation. Overexpression of p38/JNK attenuated the inhibitory effect of BX-795 on HSV replication. BX-795 completely blocked HSV-2-induced MKK4 phosphorylation, suggesting that BX-795 acting upstream of JNK and p38 MAP kinase. In conclusion, this study identifies the anti-HSV activity of BX-795 and its targeting of the JNK/p38 MAP kinase pathways in host cells.
BX - 795是3 - 磷酸肌醇依赖性激酶1（PDK1）的抑制剂，但也是IKK相关激酶、衔接蛋白激酶1（TBK1）和IKKɛ的强效抑制剂。在本研究中，我们试图阐明BX - 795抑制单纯疱疹病毒（HSV）复制的分子机制。用BX - 795处理人子宫内膜癌细胞系HEC - 1 - A或非洲绿猴肾细胞系Vero细胞，并在不同时间段感染HSV - 1或HSV - 2。BX - 795（3.125 - 25 μmol/L）呈剂量依赖性抑制HSV - 2复制，且对宿主细胞显示出低细胞毒性。在感染后12小时，BX - 795处理呈剂量依赖性抑制两个HSV立即早期（IE）基因（ICP0和ICP27）和晚期基因（gD）的表达。HSV - 2感染导致宿主细胞中PI3K和Akt激活，而BX - 795处理抑制HSV - 2诱导的Akt磷酸化和激活。然而，用LY294002和雷帕霉素阻断PI3K/Akt/mTOR并不影响HSV - 2复制。HSV - 2感染增加宿主细胞中JNK和p38的磷酸化，并在感染后8小时降低ERK磷酸化；BX - 795处理抑制HSV - 2诱导的JNK和p38丝裂原活化蛋白激酶（MAP激酶）激活以及JNK和p MAP激酶下游靶点c - Jun和ATF - 2的磷酸化。此外，SB203580（一种p38抑制剂）或SP600125（一种JNK抑制剂）呈剂量依赖性抑制宿主细胞中的病毒复制，而PD98059（一种ERK抑制剂）无效。此外，BX - 795阻断佛波酯（PMA）刺激引起的c - Jun激活以及HSV - 2介导的c - Jun核转位。BX - 795呈剂量依赖性抑制HSV - 2、PMA、肿瘤坏死因子 - α（TNF - α）刺激引起的活化蛋白 - 1（AP - 1）激活，但不抑制HSV诱导的核因子 - κB（NF - κB）激活。p38/JNK的过表达减弱了BX - 795对HSV复制的抑制作用。BX - 795完全阻断HSV - 2诱导的MKK4磷酸化，表明BX - 795作用于JNK和p38 MAP激酶的上游。总之本研究确定了BX - 795的抗HSV活性及其对宿主细胞中JNK/p38 MAP激酶途径的靶向作用。
