Expression profiling of Echinococcus multilocularis miRNAs throughout metacestode development in vitro

MACCHIAROLI N; PREZA M; PEREZ M; KAMENETZKY L; CUCHER M; KOZIOL U; CASTILLO E; BERRIMAN M; BREHM K; ROSENZVIT M

PLOS NEGLECTED TROPICAL DISEASES

PUBLIC LIBRARY SCIENCE

Lugar: San Francisco; Año: 2021

1935-2735

The neglected zoonotic disease alveolar echinococcosis (AE) is caused by the metacestode stage of the helminth parasite Echinococcus multilocularis. Current chemotherapeutical treatment requires prolonged drug therapy using benzimidazoles that are parasitostatic only. Thus, novel strategies for the treatment of AE are urgently needed. MicroRNAs (miRNAs) are a class of small non-coding RNAs with a major role in regulation of gene expression in key biological processes. In previous works, we analyzed the miRNA expression profile of E. multilocularis in vivo metacestodes and in vitro primary cell cultures. However, current knowledge about miRNA expression and their potential roles in E. multilocularis development is still limited. In this work, we analyzed for the first known time the expression profile of E. multilocularis miRNAs throughout metacestode development in vitro, determined the spatial expression of miR-71 in in vitro metacestodes and predicted miRNA functions. Small RNA libraries from different samples of E. multilocularis metacestodes, primary cell cultures and protoescoleces were sequenced. After miRNA identification, expression analyses and target prediction were performed. We identified a repertoire of 37 miRNAs in E. multilocularis, some of them absent in the host or highly divergent from their host orthologs. MiRNA expression profiling revealed a small number of highly expressed miRNAs in all samples analyzed. The high expression of these miRNAs was conserved in other cestodes, suggesting essential roles in development, survival or host-parasite interaction. Interestingly, some of these highly expressed miRNAs were absent or divergent from human host, suggesting their potential use as therapeutic targets. MiRNA differential expression analyses showed highly regulated miRNAs during the different transitions analyzed, suggesting a role in the regulation of developmental timing, host-parasite interaction, and/or in maintaining the unique developmental features of E. multilocularis metacestode. We determined that miR-71 is expressed in stem cells and in other cell types of the germinal layer in E. multilocularis in vitro metacestodes. Functional analyses of predicted miRNA targets reveals conserved functions for highly expressed miRNAs and essential roles in parasite biology. The evolutionary conservation and expression analyses of E. multilocularis miRNAs throughout the metacestode development along with the functional analyses of their predicted targets might help to identify selective therapeutic targets for treatment and control of AE.