State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning 530004, China.
College of Animal Sciences and Veterinary Medicine, Guangxi University, Nanning 530004, China.
Viruses. 2023 May 23;15(6):1223. doi: 10.3390/v15061223.
Rabies is a lethal encephalitis caused by the rabies virus (RABV) with a fatality rate near 100% after the onset of clinical symptoms in humans and animals. Microglia are resident immune cells in the central nervous system. Few studies have been conducted on the functional role of microglia in RABV infection. Here, we performed a transcriptomic analysis of mRNA expression profiles in the microglia of mouse brains intracerebrally infected with RABV. We successfully isolated single microglial cells from the mouse brains. The survival rate of dissociated microglial cells was 81.91%-96.7%, and the purity was 88.3%. Transcriptomic analysis revealed 22,079 differentially expressed mRNAs identified in the microglia of mouse brains infected with RABV strains (rRC-HL, GX074, and CVS-24) of varying virulence at 4 and 7 days post-infection (dpi) compared to the control group. The numbers of DEGs versus the control at 4 and 7 dpi in mice infected with rRC-HL, GX074, and CVS-24 were 3622 and 4590, 265 and 4901, and 4079 and 6337. The GO enrichment analysis showed that response to stress, response to external stimulus, regulation of response to stimulus, and immune system process were abundant during RABV infection. The KEGG analysis indicated that the Tlr, Tnf, RIG-I, NOD, NF-κB, MAPK, and Jak-STAT signaling pathways were involved in RABV infection at both 4 and 7 dpi. However, some phagocytosis and cell signal transduction processes, such as endocytosis, p53, phospholipase D, and oxidative phosphorylation signaling pathways, were only expressed at 7 dpi. The involvement of the Tnf and Tlr signaling pathways prompted us to construct a protein-protein interaction (PPI) network of these pathways. The PPI revealed 8 DEGs, including Mmp9, Jun, Pik3r1, and Mapk12. Notably, Il-1b interacted with Tnf and Il-6 with combined scores of 0.973 and 0.981, respectively. RABV causes significant changes in mRNA expression profiles in the microglia in mice. 22,079 differentially expressed mRNAs were identified in the microglia of mice infected with RABV strains of varying virulence at 4 and 7 dpi. The DEGs were evaluated using GO, KEGG, and PPI network analysis. Many immune pathways were up-regulated in RABV-infected groups. The findings will help elucidate the microglial molecular mechanisms of cellular metabolism dysregulated by RABV and may provide important information for investigating RABV pathogenesis and therapeutic methods.
狂犬病是一种由狂犬病病毒（RABV）引起的致命脑炎，在人类和动物出现临床症状后，死亡率接近 100%。小胶质细胞是中枢神经系统中的固有免疫细胞。目前，关于 RABV 感染中小胶质细胞的功能作用，仅有少数研究进行了探讨。在此，我们对 RABV 感染后，病毒毒力不同的鼠脑内 RABV 株（rRC-HL、GX074 和 CVS-24）感染的小胶质细胞的 mRNA 表达谱进行了转录组分析。我们成功从小鼠脑中分离出了单个小胶质细胞。分离得到的小胶质细胞的存活率为 81.91%-96.7%，纯度为 88.3%。转录组分析显示，与对照组相比，感染 rRC-HL、GX074 和 CVS-24 的鼠脑小胶质细胞在感染后 4 天和 7 天（dpi）有 22079 个差异表达的 mRNAs。rRC-HL、GX074 和 CVS-24 感染的小鼠在 4dpi 和 7dpi 的差异基因数量分别为 3622 和 4590、265 和 4901、4079 和 6337。GO 富集分析显示，在 RABV 感染过程中，应激反应、对外界刺激的反应、对刺激的反应调节以及免疫系统过程等十分丰富。KEGG 分析表明，在 4dpi 和 7dpi 时，Tlr、Tnf、RIG-I、NOD、NF-κB、MAPK 和 Jak-STAT 信号通路均参与了 RABV 感染。然而，一些吞噬作用和细胞信号转导过程，如内吞作用、p53、磷脂酶 D 和氧化磷酸化信号通路，仅在 7dpi 时表达。Tnf 和 Tlr 信号通路的参与促使我们构建了这些通路的蛋白质-蛋白质相互作用（PPI）网络。该 PPI 揭示了 8 个差异表达基因，包括 Mmp9、Jun、Pik3r1 和 Mapk12。值得注意的是，Il-1b 与 Tnf 相互作用，而 Il-6 与 Tnf 结合的综合评分为 0.973，与 Il-6 结合的综合评分为 0.981。RABV 会导致小鼠小胶质细胞的 mRNA 表达谱发生显著变化。在感染不同毒力的 RABV 株后，4dpi 和 7dpi 时，病毒感染的小鼠小胶质细胞中有 22079 个差异表达 mRNAs。采用 GO、KEGG 和 PPI 网络分析对差异基因进行了评估。在 RABV 感染组中，许多免疫通路被上调。这些发现将有助于阐明 RABV 引起的细胞代谢失调中小胶质细胞的分子机制，并为研究 RABV 发病机制和治疗方法提供重要信息。
