Since many of the currently available antileishmanial treatments exhibit toxicity, low effectiveness, and resistance, search and validation of new therapeutic targets allowing the development of innovative drugs have become a worldwide priority. This work presents a structure-based drug discovery strategy to validate the Lmj_04_BRCT domain as a novel therapeutic target in Leishmania spp. The structure of this domain was explored using homology modeling, virtual screening, and molecular dynamics studies. Candidate compounds were validated in vitro using promastigotes of Leishmania major, L. amazonensis, and L. infantum, as well as primary mouse macrophages infected with L. major. The novel inhibitor CPE2 emerged as the most active of a group of compounds against Leishmania, being able to significantly reduce the viability of promastigotes. CPE2 was also active against the intracellular forms of the parasites and significantly reduced parasite burden in murine macrophages without exhibiting toxicity in host cells. Furthermore, L. major promastigotes treated with CPE2 showed significant lower expression levels of several genes (α-tubulin, Cyclin CYCA, and Yip1) related to proliferation and treatment resistance. Our in silico and in vitro studies suggest that the Lmj_04_BRCT domain and its here disclosed inhibitors are new potential therapeutic options against leishmaniasis.

Resumen La leishmaniasis es endémica en países de la cuenca mediterránea. En el presente estudio se revisa la información disponible sobre la leishmaniasis en Navarra y en regiones limítrofes en el periodo 1976-2018, y se aporta una visión general de la situación de esta enfermedad a nivel nacional, desde el vector hasta el hombre. La tasa de incidencia de leishmaniasis disminuyó en Aragón entre 2008 y 2018 respecto a la década anterior, mientras que en Navarra y La Rioja casi se duplicaron los casos por 100.000 habitantes; el País Vasco también presentó un aumento en la incidencia. El incremento de casos a nivel nacional ha sido significativo desde 2015, en parte debido a la inclusión de la leishmaniasis como enfermedad de declaración obligatoria. Si bien su incidencia en humanos no parece preocupante, la leishmaniasis es hoy una realidad en España, por lo que es necesario vigilar globalmente su evolución.

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