Table_3_Differential Brain MicroRNA Expression Profiles After Acute and Chronic Infection of Mice With Toxoplasma gondii Oocysts.docx

Brain microRNAs (miRNAs) change in abundance in response to Toxoplasma gondii infection. However, their precise role in the pathogenesis of cerebral infection with T. gondii oocyst remains unclear. We studied the abundance of miRNAs in the brain of mice on days 11 and 33 post-infection (dpi) in order to identify miRNA pattern specific to early (11 dpi) and late (33 dpi) T. gondii infection. Mice were challenged with T. gondii oocysts (Type II strain) and on 11 and 33 dpi, the expression of miRNAs in mouse brain was investigated using small RNA (sRNA) sequencing. miRNA expression was confirmed by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed to identify the biological processes, molecular functions, and cellular components, as well as pathways involved in infection. More than 1,500 miRNAs (1,352 known and 150 novel miRNAs) were detected in the infected and control mice. The expression of miRNAs varied across time after infection; 3, 38, and 108 differentially expressed miRNAs (P < 0.05) were detected during acute infection, chronic infection and chronic vs. acute infection, respectively. GO analysis showed that chronically infected mice had more predicted targets of dysregulated miRNAs than acutely infected mice. KEGG analysis indicated that most predicted targets were involved in immune- or disease-related pathways. Our data indicate that T. gondii infection alters the abundance of miRNAs in mouse brain particularly at the chronic stage, probably to fine-tune conditions required for the establishment of a latent brain infection.

脑部小分子RNA（miRNA）在弓形虫Toxoplasma gondii感染后，其丰度发生改变。然而，这些RNA在T. gondii子囊虫引起的脑部感染发病机制中的精确作用尚不明确。本研究旨在通过检测感染后第11天和第33天小鼠脑部miRNA的丰度，以识别早期（11天）和晚期（33天）T. gondii感染特有的miRNA模式。实验小鼠被挑战感染T. gondii子囊虫（II型菌株），于感染后第11天和第33天，采用小RNA（sRNA）测序技术对小鼠脑部miRNA的表达进行检测。miRNA的表达通过定量逆转录聚合酶链反应（qRT-PCR）得到验证。通过基因本体（GO）富集分析和京都基因与基因组百科全书（KEGG）通路分析，旨在识别与感染相关的生物学过程、分子功能和细胞组分，以及参与感染途径。在感染组和对照组小鼠中，共检测到超过1,500种miRNA（包括1,352种已知miRNA和150种新型miRNA）。感染后，miRNA的表达随时间变化而变化；在急性感染期、慢性感染期以及慢性与急性感染对比中，分别检测到3、38和108种差异表达miRNA（P < 0.05）。GO分析显示，慢性感染小鼠中失调miRNA的预测靶标数量多于急性感染小鼠。KEGG分析表明，大多数预测靶标涉及免疫或疾病相关通路。本研究数据表明，T. gondii感染可改变小鼠脑部miRNA的丰度，尤其是在慢性感染阶段，这可能是为了微调建立潜伏性脑部感染所需的条件。