Japanese encephalitis virus (JEV) infection induces brain tissue disease characterized by neuron death. however, little is known about the underlying mechanism. Using RNA sequencing, we profiled global mRNA expression changes in response to in vitro and in vivo JEV infection. Integration analysis of in vitro and in vivo mRNA transcriptome revealed that JEV infection regulated apoptosis-related Foxo signaling pathway. Foxo expression was reduced by JEV infection in vitro and in vivo. Knockdown of Foxo promoted apoptosis, while its overexpression reduced apoptosis in JEV-infected Neuro-2a cells. JEV infection in Neuro-2a cells decreased the expression of Foxo downstream genes including pro-apoptotic protein Bim, anti-apoptotic protein Bcl-6 and p21. Overexpression of anti-apoptotic proteins Bcl-6 and p21 repressed JEV-induced apoptosis. These findings suggest that Foxo primarily exerts an anti-apoptotic function via Bcl-6 and p21 in JEV-infected Neuro-2a cells. A STAT3 binding site was identified in the promoter region of Foxo by TFBIND software and confirmed by ChIP and reporter assays. JEV infection reduced STAT3 expression as well as its binding at the Foxo promoter compared to mock infection in Neuro-2a cells. Moreover, STAT3 knockdown reduced Foxo promoter activity and Foxo expression. Therefore, JEV reduced Foxo expression, at least in part, by downregulating STAT3. Taken together, we found that JEV induced cell apoptosis by inhibiting STAT3-Foxo-Bcl-6/p21 pathway, which provides a novel insight into JEV-caused encephalitis.

中文翻译：

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日本脑炎病毒通过抑制Foxo信号通路诱导细胞凋亡。

日本脑炎病毒（JEV）感染会诱发以神经元死亡为特征的脑组织疾病。但是，对于底层机制知之甚少。使用RNA测序，我们分析了响应体外和体内JEV感染的全局mRNA表达变化。体内外mRNA转录组的整合分析表明，JEV感染调节凋亡相关的Foxo信号通路。在体外和体内，JEV感染都会降低Foxo的表达。敲低Foxo促进细胞凋亡，而其过表达减少了JEV感染的Neuro-2a细胞的凋亡。JEV感染Neuro-2a细胞后，Foxo下游基因的表达降低，包括促凋亡蛋白Bim，抗凋亡蛋白Bcl-6和p21。抗凋亡蛋白Bcl-6和p21的过表达抑制了JEV诱导的细胞凋亡。这些发现表明，Foxo主要通过Jcl感染的Neuro-2a细胞中的Bcl-6和p21发挥抗凋亡功能。通过TFBIND软件在Foxo的启动子区域中鉴定出一个STAT3结合位点，并通过ChIP和报道分子分析证实。与Neuro-2a细胞中的模拟感染相比，JEV感染会降低STAT3表达及其在Foxo启动子上的结合。此外，STAT3组合式降低Foxo启动子活性和Foxo表达。因此，JEV通过下调STAT3至少部分降低了Foxo的表达。两者合计，我们发现JEV通过抑制STAT3-Foxo-Bcl-6 / p21途径诱导细胞凋亡，这为JEV引起的脑炎提供了新的见解。通过TFBIND软件在Foxo的启动子区域中鉴定出一个STAT3结合位点，并通过ChIP和报道分子分析证实。与Neuro-2a细胞中的模拟感染相比，JEV感染会降低STAT3表达及其在Foxo启动子上的结合。此外，STAT3组合式降低Foxo启动子活性和Foxo表达。因此，JEV通过下调STAT3至少部分降低了Foxo的表达。两者合计，我们发现JEV通过抑制STAT3-Foxo-Bcl-6 / p21途径诱导细胞凋亡，这为JEV引起的脑炎提供了新的见解。通过TFBIND软件在Foxo的启动子区域中鉴定出一个STAT3结合位点，并通过ChIP和报道分子分析证实。与Neuro-2a细胞中的模拟感染相比，JEV感染会降低STAT3表达及其在Foxo启动子上的结合。此外，STAT3组合式降低Foxo启动子活性和Foxo表达。因此，JEV通过下调STAT3至少部分降低了Foxo的表达。两者合计，我们发现JEV通过抑制STAT3-Foxo-Bcl-6 / p21途径诱导细胞凋亡，这为JEV引起的脑炎提供了新的见解。STAT3组合式降低Foxo启动子活性和Foxo表达。因此，JEV通过下调STAT3至少部分降低了Foxo的表达。两者合计，我们发现JEV通过抑制STAT3-Foxo-Bcl-6 / p21途径诱导细胞凋亡，这为JEV引起的脑炎提供了新的见解。STAT3组合式降低Foxo启动子活性和Foxo表达。因此，JEV通过下调STAT3至少部分降低了Foxo的表达。两者合计，我们发现JEV通过抑制STAT3-Foxo-Bcl-6 / p21途径诱导细胞凋亡，这为JEV引起的脑炎提供了新的见解。