This retrospective cohort study analysed extracellular vesicles (EVs) and microRNAs (miRNAs) excreted in canine sera from dogs with canine visceral leishmaniasis (CanVL). A total of 56 canine sera were divided into Group I (28, from healthy dogs) and Group II (28, from the same dogs, but already with CanVL). CanVL was determined by clinical and laboratory diagnoses. Canine sera were ultra‐centrifuged to recover EVs (Can‐EVs). Analyses by transmission electron microscopy, nanoparticle tracking analysis (NTA), sodium dodecyl sulfate‐poli‐acrylammide gel eletroforesis (SDS‐PAGE) and, Immunoblot confirmed the presence of (i) microvesicles/exosomes and (ii) the tetraspanins CD63 and CD9. EVs secreted by Leishmania (Leishmania) infantum‐EVs were reactive against sera from dogs with CanVL (performed by ELISA and Immunoblot). NTA analyses exhibited that concentrations of Can‐EVs from dogs with CanVL (7.78 × 1010 Can‐EVs/mL) were higher (p < .0001) than the non‐infected dogs (mean: 1.47 × 1010 Can‐EVs/mL). These results suggested that concentrations of Can‐EVs were able to distinguish dogs with CanVL from healthy dogs. The relative expressions of 11 miRNAs species (miR‐21‐5p, miR‐146a‐5p, miR‐125b‐5p, miR‐144‐3p, miR‐194‐5p, miR‐346, miR‐29c‐3p, miR‐155‐5p, miR‐24‐3p, miR‐181a‐5p, and miR‐9‐5p) were estimated in purified miRNAs of 30 canine sera. Dogs with CanVL up‐expressed miR‐21‐5p and miR‐146a‐5p when compared with healthy dogs. The other miRNA species were poorly or not expressed in canine sera. In conclusion, this study suggests that CanVL induces changes in size and concentration of Can‐EVs, as well as, the up‐expression of miR‐21‐5p and miR‐146a‐5p in infected dogs.

No abstract

O aparelho digestivo dos insetos é formado basicamente por um longo tubo que percorre seu corpo no sentido longitudinal, desde a boca até o ânus, denominado canal digestivo ou alimentar. O espaço entre o canal alimentar e a paredes do corpo é chamado hemocele ou cavidade geral, e é grandemente ocupado por sangue (hemolinfa). Neste sentido, estudos apontam que a hemolinfa de alguns insetos, por conta da presença de substâncias com potencial farmacológico, apresenta potencial antibacteriano, antiviral, antifúngico, entre outros. Neste trabalho, avaliamos o efeito citotóxico da hemolinfa obtida, a partir da criação em laboratório, de larvas de Zophobas morio Fabricius (Coleoptera:Tenebrionidae), sobre fibroblastos dérmicos humanos (CCD1072Sk – ATCC), através dos ensaios de captação do corante Tetrazoliun – MTT, método de exclusão do azul de tripano, quantificação de céluas nas diferentes fases do ciclo celular, através de citometria de fluxo e do ensaio wound healing, onde acompanhamos em tempo real a proliferação de fibroblastos. Os resultados obtidos mostraram que a hemolinfa de Zophobas morio Fabricius, não se mostrou citotóxica sobre a linhagem celular testada. Ao invés disso, na concentração de 10%, a hemolinfa se mostrou capaz de induzir proliferação dos fibroblastos (P<0,05).