High-throughput screening and analysing for circular RNA expression profile in HepG2 cells expressing genotype IV Swine Hepatitis E Virus ORF3

Swine hepatits E (SHE) is a new type of zoonotic infectious disease caused by swine hepatitis E virus (SHEV). Open reading frame 3 (ORF3) is a key regulatory and virulent protein of SHEV. Circular RNA (circRNA) is a special kind of non-coding RNA molecule, which has a closed ring structure. In this study, to identify the circRNA profile in host cells affected by SHEV ORF3, adenovirus ADV4-ORF3 mediated the overexpression of ORF3 in HepG2 cells, high-throughput sequencing was used to investigate the differentially expressed circRNAs, GO and KEGG were performed to enrich the function of hosting genes, and Targetscan and miRanda softwares were used to analyze the interaction between circRNA and miRNA. In total, 1,105 up-regulation circRNAs and 1,556 down-regulation circRNAs were identified in ADV4-ORF3 infection group compared with the control. GO function enrichment analysis of differentially expressed circRNAs-hosting genes classified three main categories (cellular component, biological process and molecular function). KEGG pathway enrichment analysis scatter plot showed the pathway term of top20. Our findings first screened and analyzed the expression profile of circRNAs in HepG2 cells expressing genotype IV Swine Hepatitis E Virus ORF3, which may facilitate further study to reveal the function of SHEV ORF3 and molecular mechanism of SHEV infection. Overall design: HepG2 cells were infected adenovirus ADV4-ORF3 and ADV4-NC (MOI=5:1) for 24h, respectively. PBS washed the cell layer three times and added Trizol to fully lyse the cells. The total RNA of six sample (Ad_GFP_1, Ad_GFP_2, Ad_GFP_3, Ad_ORF3_1, Ad_ORF3_2 and Ad_ORF3_3) were extracted for transcriptome sequencing.