Department of Biopharmacy, College of Life Science and Technology, Wuhan Polytechnic University, Wuhan, China.
Viral Vaccine Research Laboratory I, Wuhan Institute of Biological Products Co. Ltd., Wuhan, China.
Front Cell Infect Microbiol. 2024 Aug 22;14:1405689. doi: 10.3389/fcimb.2024.1405689. eCollection 2024.
Coxsackievirus A6 (CV-A6) has emerged as the predominant epidemic strain responsible for hand, foot and mouth disease (HFMD). CV-A6 infection can result in severe clinical manifestations, including encephalitis, meningitis, and potentially life-threatening central nervous system disorders. Our previous research findings demonstrated that neonatal mice infected with CV-A6 exhibited limb weakness, paralysis, and ultimately succumbed to death. However, the underlying mechanism of CV-A6-induced nervous system injury remains elusive. Numerous reports have highlighted the pivotal role of miRNAs in various viral infections.
Separately established infection and control groups of mice were used to create miRNA profiles of the brain tissues before and after CV-A6 transfection, followed by experimental verification, prediction, and analysis of the results.
At 2 days post-infection (dpi), 4 dpi, and 2dpi vs 4dpi, we identified 175, 198 and 78 significantly differentially expressed miRNAs respectively using qRT-PCR for validation purposes. Subsequently, we predicted target genes of these differentially expressed miRNAs and determined their potential targets through GO (Gene Ontology) enrichment analysis and KEGG (Kyoto Encyclopedia of Genes and Genomes) enrichment analysis. Finally, we verified the miRNA-mRNA pairing via double luciferase experiments while confirming functional enrichment of target genes through Western Blotting analyses.
The results from this study suggest that transcriptional regulation, neuronal necrosis, pro-inflammatory cytokine release, and antiviral immunity are all implicated in the pathogenesis of central nervous system injury in mice infected with CV-A6. Brain injury resulting from CV-A6 infection may involve multiple pathways, including glial cell activation, neuronal necrosis, synaptic destruction, degenerative diseases of the nervous system. It can even encompass destruction of the blood-brain barrier, leading to central nervous system injury. The dysregulated miRNAs and signaling pathways discovered in this study provide valuable insights for further investigations into the pathogenesis of CV-A6.
柯萨奇病毒 A6（CV-A6）已成为引起手足口病（HFMD）的主要流行株。CV-A6 感染可导致严重的临床表现，包括脑炎、脑膜炎，以及潜在危及生命的中枢神经系统疾病。我们之前的研究结果表明，感染 CV-A6 的新生小鼠表现出肢体无力、瘫痪，最终死亡。然而，CV-A6 诱导的神经系统损伤的潜在机制仍不清楚。许多报道强调了 miRNA 在各种病毒感染中的关键作用。
分别建立感染组和对照组的小鼠模型，在 CV-A6 转染前后进行脑组织 miRNA 谱分析，然后进行实验验证、结果预测和分析。
在感染后 2 天（dpi）、4dpi 和 2dpi 与 4dpi 时，我们分别使用 qRT-PCR 进行验证，鉴定出 175、198 和 78 个显著差异表达的 miRNA。随后，我们预测了这些差异表达 miRNA 的靶基因，并通过 GO（基因本体论）富集分析和 KEGG（京都基因与基因组百科全书）富集分析确定了它们的潜在靶基因。最后，我们通过双荧光素酶实验验证了 miRNA-mRNA 配对，并通过 Western Blotting 分析证实了靶基因的功能富集。
本研究结果表明，转录调控、神经元坏死、促炎细胞因子释放和抗病毒免疫均与 CV-A6 感染小鼠中枢神经系统损伤的发病机制有关。CV-A6 感染引起的脑损伤可能涉及多个途径，包括神经胶质细胞激活、神经元坏死、突触破坏、神经系统退行性疾病。甚至可能包括血脑屏障的破坏，导致中枢神经系统损伤。本研究中发现的失调 miRNA 和信号通路为进一步研究 CV-A6 的发病机制提供了有价值的线索。
