This article describes the data on the global expression profile of small RNA (smRNAs) molecules in mice gastrocnemius muscle exposed to jararhagin, snake venom metalloproteinase. The data include smRNAs in mice gastrocnemius muscle challenged with Jararhagin (Jar; n=4) in the right paw or phosphate-buffered saline (PBS; control; n=4) in the left paw. smRNA-Seq libraries were generated after 24 h of exposure to PBS or jararhagin. The expression profiles of smRNAs including microRNA and snoRNA were compared between both groups. The sequencing data from both groups have been uploaded to Zenodo http://dx.doi.org/10.5281/zenodo.56492.

Cathepsin L (CatL) is a lysosomal cysteine protease primarily involved in the terminal degradation of intracellular and endocytosed proteins. More specifically, in humans, CatL has been implicated in cancer progression and metastasis, as well as coronary artery diseases and others. Given this, the search for potent CatL inhibitors is of great importance. In the search for new molecules to perform proteolytic activity regulation, salivary secretions from hematophagous animals have been an important source, as they present protease inhibitors that evolved to disable host proteases. Based on the transcriptome of the Haementeria vizzotoi leech, the cDNA of Cystatin-Hv was selected for this study. Cystatin-Hv was expressed in Pichia pastoris and purified by two chromatographic steps. The kinetic results using human CatL indicated that Cystatin-Hv, in its recombinant form, is a potent inhibitor of this protease, with a Ki value of 7.9 nM. Consequently, the present study describes, for the first time, the attainment and the biochemical characterization of a recombinant cystatin from leeches as a potent CatL inhibitor. While searching out for new molecules of therapeutic interest, this leech cystatin opens up possibilities for the future use of this molecule in studies involving cellular and in vivo models.