天然小分子化合物环维黄杨星D抗登革病毒感染的作用和分子机制的研究

以登革病毒为代表的虫媒病毒近年来严重威胁人类健康，而大部分虫媒病毒仍没有安全有效疫苗和抗病毒药物。本项目利用基于荧光素酶报告基因的登革病毒复制子筛选系统，从143种天然小分子化合物文库中筛选出了一系列抑制登革病毒感染的的天然小分子单体化合物；其中，环维黄杨星D从未被报道过有抗病毒作用。我们的前期工作表明，环维黄杨星D能够调控登革病毒感染的细胞内胆固醇相关基因的表达，并激活mTOR。而mTOR、自噬、脂质代谢等过程都与登革病毒的复制密切相关。因此，本项目将利用高通量测序、细胞和动物感染、免疫印迹、荧光显微镜等技术手段，进一步研究小分子单体化合物环维黄杨星D如何通过调控胆固醇合成和转运、活化mTOR信号通路，进而影响后续病毒依赖的自噬和脂质代谢过程，发挥抗登革病毒感染的具体分子机制。这些工作将为开发基于环维黄杨星D为代表的一类三萜类化合物的抗病毒药物提供理论依据。

The arboviruses, such as Dengue virus (DENV), become serious threats to human health. But there are no safe and effective vaccines and antiviral drugs against most of the arboviruses. In this study, a luciferase based DENV replicon screening system was used to screen the antiviral compounds from a natural product compound library. A series of compounds were identified with anti-DENV activity. Among them, Cyclovirobuxine D (Cvb D) has never been reported to have any antiviral activity. Our preliminary data suggested that Cvb D upregulated the cholesterol level in DENV infected cells and further activated mTOR. Furthermore, mTOR, autophagy and lipid metabolism were reported to be highly associated with DENV replication. High throughput RNA sequencing, cell and animal infection models, immunoblotting and fluorescence microscopy will be employed to study how Cvb D modulates cholesterol synthesis/transport, activates mTOR pathway, and further influences the virus dependent autophagy and lipid metabolisms. This study will provide the theoretical basis for the development the novel antiviral drugs based on the triterpenoid compounds such as Cvb D.