Comparative Analysis of miRNA Expressions in Different Developmental Stages of Echinococcus granulosus in Mono-Phasic and Di-Phasic Culture Systems

Background: The dog tapeworm, Echinococcus granulosus, is a zoonotic parasite affecting humans and livestock across the globe. Basic research on the molecular biology and genetics of E. granulosus improves our understanding of the biology and potential drug targets in various developmental stages of E. granulosus in both definitive and intermediate hosts. There has been increasing interest in the identification of microRNAs in parasitic organisms. The purpose of the current study was to compare the activity of a selected profile of miRNAs in different developmental stages of E. granulosus. Methods: Different developmental stages of the parasite were obtained from ex vivo as well as in vitro cultured E. granulosus. MicroRNAs were extracted from the ex vivo germinal layer and invaginated protoscoleces as well as the in vitro generated microcysts, evaginated protoscoleces, and strobilated worms. The expression of the selected miRNAs was evaluated by RT-qPCR for each stage. Results: Four out of five miRNAs were present and active in different developmental stages of E. granulosus. A significant over-expression of miR-61 was observed in the germinal layer and during the protoscolex transformation into the microcysts, however, miR-10 was more expressed in the mature strobilated forms than in the other stages. Let-7 and miR-3489 showed a high expression in the germinal layer. Conclusion: Differential expression of four miRNAs among different in vitro and ex vivo developmental stages of E. granulosus was documented in the present study. Further experimental investigations are required to elucidate the probable role of the miRNAs in bi-directional differentiation of protoscoleces either into the strobilated worm or to a secondary hydatid cyst and the potential of these miRNAs as drug targets.