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https://www.arca.fiocruz.br/handle/icict/23651
INVOLVEMENT OF NUCLEOSIDE DIPHOSPHATE KINASE B AND ELONGATION FACTOR 2 IN LEISHMANIA BRAZILIENSIS ANTIMONY RESISTANCE PHENOTYPE
Nucleoside diphosphate kinase b
Elongation factor 2
Chemotherapy
Antimony resistance
Affilliation
Fundação Oswaldo Cruz. Instituto René Rachou. Belo Horizonte, MG, Brazil
Fundação Oswaldo Cruz. Instituto René Rachou. Belo Horizonte, MG, Brazil
Fundação Oswaldo Cruz. Instituto René Rachou. Belo Horizonte, MG, Brazil
Abstract
Background: Nucleoside diphosphate kinase b (NDKb) is responsible for nucleoside triphosphates synthesis and it has key role in the purine metabolism in trypanosomatid protozoans. Elongation factor 2 (EF2) is an important factor for protein synthesis. Recently, our phosphoproteomic analysis demonstrated that NDKb and EF2 proteins were phosphorylated and dephosphorylated in antimony (SbIII)-resistant L. braziliensis line compared to its SbIII-susceptible pair, respectively.
Methods; In this study, the overexpression of NDKb and EF2 genes in L. braziliensis and L. infantum was performed to investigate the contribution of these proteins in the SbIII-resistance phenotype. Furthermore, we examined the role of lamivudine on SbIII susceptibility in clones that overexpress the NDKb gene, and the effect of EF2 kinase (EF2K) inhibitor on the growth of EF2-overexpressing parasites.
Results: Western blot analysis demonstrated that NDKb and EF2 proteins are more and less expressed, respectively, in SbIII-resistant line of L. braziliensis than its wild-type (WTS) counterpart, corroborating our previous phosphoproteomic data. NDKb or EF2-overexpressing L. braziliensis lines were 1.6 to 2.1-fold more resistant to SbIII than the untransfected WTS line. In contrast, no difference in SbIII susceptibility was observed in L. infantum parasites overexpressing NDKb or EF2. Susceptibility assays showed that NDKb-overexpressing L. braziliensis lines presented elevated resistance to lamivudine, an antiviral agent, but it did not alter the leishmanicidal activity in association with SbIII. EF2-overexpressing L. braziliensis clone was slightly more resistant to EF2K inhibitor than the WTS line. Surprisingly, this inhibitor increased the antileishmanial effect of SbIII, suggesting that this association might be a valuable strategy for leishmaniasis chemotherapy.
Conclusion: Our findings represent the first study of NDKb and EF2 genes overexpression that demonstrates an increase of SbIII resistance in L. braziliensis which can contribute to develop new strategies for leishmaniasis treatment.
Keywords in Portuguese
Leishmania spp.,Keywords
Leishmania spp.,Nucleoside diphosphate kinase b
Elongation factor 2
Chemotherapy
Antimony resistance
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