Differential expression of proteins in Leishmania (Viannia) panamensis associated with mechanisms of resistance to meglumine antimoniate Expresión diferencial de proteínas en Leishmania (Viannia) panamensis asociadas con mecanismos de resistencia a antimoniato de meglumina

Introduction. The well known drug resistance mechanisms to pentavalent antimony have been widely described in strains of the Leishmania subgenus, but little is known about the mechanisms of resistance and the proteins associated with it in strains of the Viannia subgenus such as Leishmania panamensis. Objective. To identify differentially expressed proteins between pentavalent antimonial sensitive and resistant L. panamensis (UA140) strains and to analyze the possible role of these proteins in the resistance mechanism. Materials and methods. The protein lysates of both pentavalent antimony sensitive and resistant strains were separated by two-dimensional gel electrophoresis and the protein patterns compared. The proteins identified as overexpressed were separated and analyzed using MALDI-TOF/TOF (Matrix Assisted Laser Desorption Ionization/Time of Flight). The level of mRNA expression of five of these proteins was quantified using real-time PCR. Results. 532 ± 39 and 541 ± 43 protein spots were detected on the two-dimensional gels of the sensitive and resistant strains, respectively. Ten spots were overexpressed in the resistant strain, identified as heat shock protein (Hsp60 mitochondrial, Hsp70 cytosolic and mitochondrial), disulfide isomerase, cysteine protease, enolase, elongation factor 5-alpha, the proteasome alpha-5 subunit and two hypothetical proteins named as Sp(2) and Sp(25). Conclusion. This is the first proteomic study conducted with a L. panamensis resistant strain where several proteins were identified and related with the parasite resistance mechanism to pentavalent antimony. This opens the way for future studies aimed at modulating the drug resistance or at evaluating these proteins as therapeutic targets. Introducción. Los mecanismos de resistencia a antimonio pentavalente conocidos hasta el momento se han descrito ampliamente en cepas del subgénero Leishmania, pero poco se sabe sobre las proteínas involucradas en los mecanismos de resistencia presentes en cepas del subgénero Viannia como Leishmania panamensis. Objetivo. Identificar proteínas diferencialmente expresadas entre las cepas de L. panamensis (UA140) sensible y resistente a antimonio pentavalente y analizar el posible papel de estas proteínas en mecanismos de resistencia. Materiales y métodos. Las proteínas de las cepas sensible y resistente a antimonio pentavalente se compararon usando electroforesis bidimensional. Las proteínas sobreexpresadas fueron aisladas e identificadas por espectrometría de masas mediante MALDI-TOF/TOF (Matrix Assisted Laser Desorption Ionization/Time