MicroRNA expression dynamics in mouse liver at different stages of Echinococcus multilocularis infection

Alveolar echinococcosis (AE) is a globally widespread zoonotic disease caused by the larval stage of the tapeworm Echinococcus multilocularis, posing a high fatality rate and poor prognosis if not properly managed. Currently, effective vaccines or drugs for echinococcosis remain elusive. MicroRNAs (miRNAs) play crucial roles in various biological processes and are closely linked with parasite infection and pathogenicity. To date, there is limited knowledge about host miRNA profiles in E. multilocularis infection at different stages. Hence, exploring host miRNA expression patterns at different infection stages is vital for understanding miRNA transcriptional regulation mechanisms.

This study employs small RNA sequencing to depict the temporal dynamics of miRNAs in mice liver at 40, 80, and 120 dpi with E. multilocularis. Additionally, Short Time-series Expression Miner, Gene ontology, KEGG pathway, and miRNA-target gene-pathway network analysis were conducted to elucidate each miRNA's changing trends, focusing on the hub miRNAs during infection. Subsequently, miRNA altering patterns at 40, 80, and 120 dpi were confirmed via quantitative real-time PCR.

The findings reveal time-dependent miRNA expression profiles, categorized into three distinct patterns specific to early, middle, and late infection stages. Overall, 61 miRNAs were stage-differentially expressed in the livers of infected mice compared to uninfected mice, with 29 miRNAs up-regulated and 32 miRNAs down-regulated. Notably, in the early phase, 23 miRNAs showed differential expression, with 18 up-regulated and 5 down-regulated (|log₂FC| >1, P < 0.05). Moreover, genes regulated during this phase primarily involved in Th17 cell differentiation, AMPK signaling pathway, and Calcium signaling pathway. Subsequently, during the middle infection stage, a total of 16 miRNAs exhibited differential expression, with 8 up-regulated and 8 down-regulated (|log₂FC| >1, P < 0.05). These miRNAs are involved in prolactin signaling pathway, aldosterone synthesis secretion, and Cushing's syndrome. In the late infection stage, 22 differentially expressed miRNAs were identified, with 3 up-regulated and 19 down-regulated (|log₂FC| >1, P < 0.05). Furthermore, the identified target genes primarily participated in ECM-receptor interaction, TGF-β signaling pathway, and human papillomavirus infection pathway. Also, through network interaction analysis, it was speculated that Src, Jag1, and Mapk1 exhibited the most hub signaling genes during the early, middle, and late infection stages, respectively, while the Srf was dynamically expressed hub signaling gene throughout the whole infection stage. As the disease progresses, several hub networks have been identified around target genes, including the mmu-miR-1247-5p-Src-Rap1 signaling pathway, mmu-miR-149-5p-Jag1-Notch signaling pathway, mmu-miR-299a-5p-Mapk1-human papillomavirus infection pathway in the early, middle and late stages, respectively. Additionally, the mmu-miR-122-3p-Srf-MAPK signaling pathway was predicted to be the hub network in the whole infection stage.

Overall, our investigation elucidates the temporal dynamic changes in host miRNAs and their potential target genes at the early, middle and late stages of E. multilocularis infection, which allows us to understand the roles of miRNAs in host-parasite interactions throughout infection and provides a reference for further studies of molecular pathogenesis and new drug or vaccine targets for control of AE.