Deubiquitinating enzymes as possible drug targets for schistosomiasis.

Deubiquitinating enzymes (DUBs) are conserved in Schistosoma mansoni and may be linked to the 26S proteasome. Previous results from our group showed that b-AP15, an inhibitor of the 26S proteasome DUBs UCHL5 and USP14 induced structural and gene expression changes in mature S. mansoni pairs. This work suggests the use of the nonselective DUB inhibitor PR-619 to verify whether these enzymes are potential target proteins for new drug development. Our approach is based on previous studies with DUB inhibitors in mammalian cells that have shown that these enzymes are associated with apoptosis, autophagy and the transforming growth factor beta (TGF-ß) signaling pathway. PR-619 inhibited oviposition in parasite pairs in vitro, leading to mitochondrial changes, autophagic body formation, and changes in expression of SmSmad2 and SmUSP9x, which are genes linked to the TGF-ß pathway that are responsible for parasite oviposition and SmUCHL5 and SmRpn11 DUB maintenance. Taken together, these results indicate that DUBs may be used as targets for the development of new drugs against schistosomiasis.

Detection of Schistosoma mansoni long non-coding RNAs in the infected C57BL/6 mouse liver.

Long non-coding RNAs (lncRNAs) perform several types of regulatory functions and have been recently explored in the genus Schistosoma. Although sequencing and bioinformatics approaches have demonstrated the presence of hundreds of lncRNAs and microRNAs (miRNAs) in this genus, information regarding their abundance, characteristics, and potential functions linked to Schistosoma mansoni biology and parasite-host interaction is limited. Our objectives in the present study were to verify whether 15 previously identified S. mansoni lncRNAs are detectable in the host liver. In addition, we assess whether these lncRNAs are present in the S. mansoni infective form and the stages inside the definitive host. The detection of these 15 S. mansoni lncRNAs and a long terminal repeat (LTR) retrotransposon Saci 4 was performed in the eggs, cercariae, and 3.5-h schistosomula. All lncRNAs were found to be expressed in these stages; some of the lncRNAs were found in the livers of the infected C57BL/6 mice. In conclusion, S. mansoni lncRNAs were detected in host livers and quantified. Furthermore, many of the lncRNAs analyzed showed differential expression in the larval stages, indicating that they play a stage-specific regulatory role.