School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China.
Institute of Comparative Medicine and Center of Laboratory Animals, Southern Medical University, Guangzhou, China.
Int J Biol Sci. 2018 Jun 8;14(9):1099-1108. doi: 10.7150/ijbs.26400. eCollection 2018.
Clinical evidence suggests that there exists a strong correlation between Zika virus (ZIKV) infection and abnormal development of the nervous system. However, the underlying mechanisms remain to be elusive. In this study, recombinant lentiviral vectors coding for ZIKV structural proteins and truncations (prM-Env, M-Env and Env) were transduced into PC12 cells. Envelope (Env) overexpression induced significant inhibition of proliferation and triggered G2/M cell cycle arrest and apoptosis in PC12 cells. Flow cytometry and western blot analysis showed that the apoptosis was associated with up-regulation of both p53 and p21 and down-regulation of cyclin B1. Presence of aberrant nuclei clusters were confirmed by immunofluorescence staining analysis. The data indicate that overexpression of prM-Env, M-Env or Env led to apoptosis via an intrinsic cell death signaling pathway that is dependent on the activation of caspase-9 and caspase-3 and accompanied by an increased ratio of Bax to Bcl-2 in transduced PC12 cells. In summary, our results suggest that ZIKV Env protein causes apoptosis in PC12 cells via an intrinsic cell death signaling pathway, which may contribute to ZIKV-induced abnormal development of the nervous system.
临床证据表明，寨卡病毒（ZIKV）感染与神经系统的异常发育之间存在很强的相关性。然而，其潜在机制仍难以捉摸。在这项研究中，编码 ZIKV 结构蛋白和截短体（prM-Env、M-Env 和 Env）的重组慢病毒载体被转导到 PC12 细胞中。包膜（Env）过表达显著抑制增殖，并在 PC12 细胞中引发 G2/M 细胞周期阻滞和细胞凋亡。流式细胞术和 Western blot 分析表明，凋亡与 p53 和 p21 的上调以及细胞周期蛋白 B1 的下调有关。免疫荧光染色分析证实了异常核簇的存在。数据表明，prM-Env、M-Env 或 Env 的过表达通过依赖于半胱天冬酶-9 和半胱天冬酶-3 激活的内在细胞死亡信号通路导致 PC12 细胞凋亡，并伴有转导的 PC12 细胞中 Bax 与 Bcl-2 的比值增加。总之，我们的结果表明，ZIKV Env 蛋白通过内在的细胞死亡信号通路导致 PC12 细胞凋亡，这可能导致 ZIKV 诱导的神经系统异常发育。
