microRNAs in Taenia crassiceps and Taenia solium: characterization and future applications

MACCHIAROLI N; PEREZ M; ROSENZVIT M; CUCHER M

Congreso; LXI Reunión Anual de la Sociedad Argentina de Investigación Clínica (SAIC); 2016

The cestode parasite Taenia solium is the etiological agent of neurocisticercosis, one of the 17 neglected tropical diseases prioritized by the WHO. Taenia crassiceps, another cestode from the same genus, is used as a laboratory model of T. solium. microRNAs (miRNAs) are smallnon-coding RNAs considered master regulators of gene expression with key roles in diverse cellular processes. At present there is no evidence of miRNAs from these parasites. High-throughput characterization of small RNAs (sRNAs) in T. crassiceps larval stage (cisticercus) is presented. RNA was purified from cysticerci (3 biological replicates), sRNA library was constructed and sequenced with HiSeq 2500. The mirDeep2 software was used for miRNA identification. The T. solium genome was used for bioinformatics analyses, since it is the closest genome available, allowing also to identify T. solium miRNAs at the genome level. Experimental validation of selected sequences was performed by Northern blotting. The results obtained showed that miRNAs were the most abundant category of sRNAs accounting for 83% of mapped reads. A final high confidence set of 42 miRNAs: 38 conserved and 4 novel, was obtained. Northern blot results showed bands compatible with miRNA biogenesis, allowing validating identified miRNAs. Expression analysis showed that few miRNAs accounted for most miRNA expression. Previous results of our group (Cucher et al, 2015; Macchiaroli et al, 2015, Basika et al, 2016) showed that these set of miRNAs is conserved and also highly expressed in other cestodes including Echinococcus spp, suggesting important roles in cestode biology. We are currently predicting genes regulated by the highly expressed miRNAs in cestodes,some of which are absent or divergent in the mammal hosts. This is the first report of miRNAs in T.crassiceps and T. solium. Highly expressed parasite miRNAs absent or divergent in the hosts were indentified and could be candidates for drug and diagnosis targeting.