02508nas a2200289   4500000000100000008004100001260001200042100001200054700001500066700001400081700001200095700001300107700001600120700002500136700001200161700001400173700001300187700001400200700001500214700002500229245006900254856009000323300001000413490000700423520177400430022001402204       2020                            d  c07/20201 aPinto P1 ada Silva M1 aMoreira F1 aBouth R1 aGobbo AR1 aSandoval TV1 aRibeiro-Dos-Santos A1 aVidal A1 aBarreto J1 aSantos S1 aSpencer J1 aSalgado CG1 aRibeiro-Dos-Santos A00aLeprosy piRnome: exploring new possibilities for an old disease.  uhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC7387468/pdf/41598_2020_Article_69355.pdf  a126480 v103 a<p>Leprosy, which is caused by the human pathogen Mycobacterium leprae, causes nerve damage, deformity and disability in over 200,000 people every year. Because of the long doubling time of M. leprae (13 days) and the delayed onset of detectable symptoms, which is estimated to be approximately 3-7 years after infection, there is always a large percentage of subclinically infected individuals in the population who will eventually develop the disease, mainly in endemic countries. piRNAs comprise the largest group of small noncoding RNAs found in humans, and they are distinct from microRNAs (miRNAs) and small interfering RNAs (siRNAs). piRNAs function in transposon silencing, epigenetic regulation, and germline development. The functional role of piRNAs and their associated PIWI proteins have started to emerge in the development of human cancers and viral infections, but their relevance to bacterial diseases has not been investigated. The present study reports the piRNome of human skin, revealing that all but one of the piRNAs examined are downregulated in leprosy skin lesions. Considering that one of the best characterized functions of piRNAs in humans is posttranscriptional mRNA silencing, their functions are similar to what we have described for miRNAs, including acting on apoptosis, M. leprae recognition and engulfment, Schwann cell (SC) demyelination, epithelial-mesenchymal transition (EMT), loss of sensation and neuropathic pain. In addition to new findings on leprosy physiopathology, the discovery of relevant piRNAs involved in disease processes in human skin may provide new clues for therapeutic targets, specifically to control nerve damage, a prominent feature of leprosy that has no currently available pharmaceutical treatment.</p>  a2045-2322