Molecular Biology Unit, Faculty of Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi, U.P., India.
Molecular Biology Unit, Faculty of Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi, U.P., India.
Biochim Biophys Acta Gene Regul Mech. 2020 Nov;1863(11):194639. doi: 10.1016/j.bbagrm.2020.194639. Epub 2020 Sep 26.
Japanese Encephalitis Virus (JEV) is a single positive strand RNA virus, belongs to the Flaviviridae family. JEV is neurotropic in nature which accounts for 30-50% neurological, psychiatric sequelae and movement disorder, with 20-30% case fatality rate among children or elder population. JEV causes neuronal loss and microglial activation which leads to neuroinflammation. The microRNAs are the molecular switches, which regulate the gene expression post-transcriptionally. The microRNA-155 has been reported to be associated with CNS-related pathologies like, experimental autoimmune encephalitis, multiple sclerosis and amyotrophic lateral sclerosis. In the present study, we infected microglial cells with JEV, which resulted in the up-regulation of microRNA-155; quantified by real-time polymerase chain reaction. The gene target prediction databases revealed pellino 1 as a putative gene target for microRNA-155. The over-expression based studies of microRNA-155 mimics, scrambles, inhibitors, and cy3 negative control demonstrated the role of PELI1 in the regulation of the non-canonical NF-κB pathway via TRAF3. The luciferase assay showed the regulation of NF-κB promoter via microRNA-155 in JEV infected microglial cells. The suppression of NF-κB in JEV infected microglial cells led to the reduced expression of IL-6 and TNF-α. JEV exploits cellular microRNA-155 to suppress the expression of PELI1 in human microglial cells as a part of their immune evasion strategy.
日本脑炎病毒（JEV）是一种单正链 RNA 病毒，属于黄病毒科。JEV 具有嗜神经性，导致 30-50%的神经系统、精神后遗症和运动障碍，儿童或老年人群的病死率为 20-30%。JEV 导致神经元丧失和小胶质细胞激活，从而引发神经炎症。microRNA 是分子开关，可在后转录水平调节基因表达。microRNA-155 已被报道与 CNS 相关疾病有关，如实验性自身免疫性脑脊髓炎、多发性硬化症和肌萎缩侧索硬化症。在本研究中，我们用 JEV 感染小胶质细胞，导致 microRNA-155 的上调；通过实时聚合酶链反应进行定量。基因靶标预测数据库显示 Pellino 1 是 microRNA-155 的一个假定基因靶标。基于 microRNA-155 模拟物、对照物、抑制剂和 Cy3 阴性对照的过表达研究表明，PELI1 通过 TRAF3 在非经典 NF-κB 通路中起调节作用。荧光素酶测定显示，microRNA-155 调节 JEV 感染的小胶质细胞中的 NF-κB 启动子。在 JEV 感染的小胶质细胞中抑制 NF-κB 导致 IL-6 和 TNF-α 的表达减少。JEV 利用细胞 microRNA-155 抑制人小胶质细胞中 PELI1 的表达，作为其免疫逃避策略的一部分。
