Center for Biomedical Engineering and Technology, Department of Physiology, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.
Viral Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD, 20910, USA.
Antiviral Res. 2019 Nov;171:104590. doi: 10.1016/j.antiviral.2019.104590. Epub 2019 Aug 14.
Two major flaviviruses, dengue virus (DENV) and Zika virus (ZIKV), cause severe health and economic burdens worldwide. Recently, genome-wide screenings have uncovered the importance of regulators of the Hrd1 ubiquitin ligase-mediated endoplasmic reticulum (ER)-associated degradation (ERAD) pathway for flavivirus replication in host cells. Here we report the identification of the compound Bardoxolone methyl (CDDO-me) as a potent inhibitor of the Hrd1 ubiquitin ligase-mediated ERAD, which possesses a broad-spectrum activity against both DENV and ZIKV. Cellular thermal shift assay (CETSA) suggested that CDDO-me binds to grp94, a key component of the Hrd1 pathway, at a low nanomolar concentration, whereas interaction was not detected with its paralog Hsp90. CDDO-me and the grp94 inhibitor PU-WS13 substantially suppressed DENV2 replication and the cytopathic effects caused by DENV and ZIKV infection. The antiviral activities of both compounds were demonstrated for all four DENV serotypes and four ZIKV strains in multiple human cell lines. This study defines grp94 as a crucial host factor for flavivirus replication and identified CDDO-me as a potent small molecule inhibitor of flavivirus infection. Inhibition of grp94 may contribute to the antiviral activity of CDDO-me. Further investigation of grp94 inhibitors may lead to a new class of broad-spectrum anti-flaviviral medications.
两种主要的黄病毒，登革热病毒（DENV）和寨卡病毒（ZIKV），在全球范围内造成严重的健康和经济负担。最近，全基因组筛选发现，Hrd1 泛素连接酶介导的内质网（ER）相关降解（ERAD）途径的调节剂对于黄病毒在宿主细胞中的复制非常重要。在这里，我们报告了化合物 Bardoxolone methyl（CDDO-me）的鉴定，它是一种有效的 Hrd1 泛素连接酶介导的 ERAD 抑制剂，对 DENV 和 ZIKV 具有广谱活性。细胞热转移分析（CETSA）表明，CDDO-me 以低纳摩尔浓度结合到 Hrd1 途径的关键组成部分 grp94，而与其同工型 Hsp90 没有检测到相互作用。CDDO-me 和 grp94 抑制剂 PU-WS13 可显著抑制 DENV2 复制以及 DENV 和 ZIKV 感染引起的细胞病变效应。这两种化合物在多种人细胞系中对所有四种 DENV 血清型和四种 ZIKV 株均显示出抗病毒活性。本研究将 grp94 定义为黄病毒复制的关键宿主因子，并将 CDDO-me 鉴定为黄病毒感染的有效小分子抑制剂。grp94 的抑制可能有助于 CDDO-me 的抗病毒活性。进一步研究 grp94 抑制剂可能会导致一类新的广谱抗黄病毒药物。
