Supasorn Oratai, Tongtawe Pongsri, Srimanote Potjanee, Rattanakomol Patthaya, Thanongsaksrikul Jeeraphong
Graduate Program in Biomedical Sciences, Faculty of Allied Health Sciences, Thammasat University, 99 Moo 18 Paholyothin Road, Klong Luang, Rangsit, Pathum Thani, 12120, Thailand.
J Neurovirol. 2020 Apr;26(2):201-213. doi: 10.1007/s13365-019-00824-0. Epub 2020 Jan 13.
Enterovirus A71 (EV-A71) is one of the causative agents causing the hand-foot-mouth disease which associated with fatal neurological complications. Several sporadic outbreaks of EV-A71 infections have been recently reported from Asia-Pacific regions and potentially established endemicity in the area. Currently, there is no effective vaccine or antiviral drug for EV-A71 available. This may be attributable to the limited information about its pathogenesis. In this study, the recombinant nonstructural 2B protein of EV-A71 was successfully produced in human neuroblastoma SH-SY5Y cells and evaluated for its effects on induction of the cell apoptosis and the pathway involved. The EV-A71 2B-transfected SH-SY5Y cells showed significantly higher difference in the cell growth inhibition than the mock and the irrelevant protein controls. The transfected SH-SY5Y cells underwent apoptosis and showed the significant upregulation of caspase-9 (CASP9) and caspase-12 (CASP12) genes at 3- and 24-h post-transfection, respectively. Interestingly, the level of cytosolic Ca was significantly elevated in the transfected SH-SY5Y cells at 6- and 12-h post-transfection. The caspase-9 is activated by mitochondrial signaling pathway while the caspase-12 is activated by ER signaling pathway. The results suggested that EV-A71 2B protein triggered transient increase of the cytosolic Ca level and associated with ER-mitochondrial interactions that drive the caspase-dependent apoptosis pathways. The detailed mechanisms warrant further studies for understanding the implication of EV-A71 infection in neuropathogenesis. The gained knowledge is essential for the development of the effective therapeutics and antiviral drugs.
肠道病毒A71（EV-A71）是导致手足口病的病原体之一，该疾病与致命的神经并发症相关。最近，亚太地区报告了几起EV-A71感染的散发性疫情，该地区可能已形成地方流行性。目前，尚无针对EV-A71的有效疫苗或抗病毒药物。这可能归因于其发病机制的信息有限。在本研究中，EV-A71的重组非结构2B蛋白在人神经母细胞瘤SH-SY5Y细胞中成功产生，并评估了其对细胞凋亡诱导作用及相关途径。与模拟转染和无关蛋白对照相比，转染了EV-A71 2B的SH-SY5Y细胞在细胞生长抑制方面表现出显著更高的差异。转染后的SH-SY5Y细胞发生凋亡，分别在转染后3小时和24小时显示半胱天冬酶-9（CASP9）和半胱天冬酶-12（CASP12）基因显著上调。有趣的是，转染后的SH-SY5Y细胞在转染后6小时和12小时胞质钙水平显著升高。半胱天冬酶-9由线粒体信号通路激活，而半胱天冬酶-12由内质网信号通路激活。结果表明，EV-A71 2B蛋白触发了胞质钙水平的短暂升高，并与内质网-线粒体相互作用相关，从而驱动半胱天冬酶依赖性凋亡途径。详细机制有待进一步研究，以了解EV-A71感染在神经发病机制中的意义。所获得的知识对于开发有效的治疗方法和抗病毒药物至关重要。
