Cytosolic NADPH Homeostasis in Glucose-starved Procyclic Trypanosoma brucei Relies on Malic Enzyme and the Pentose Phosphate Pathway Fed by Gluconeogenic Flux

Allmann, Stefan; Morand, Pauline; Ebikeme, Charles; Gales, Lara; Biran, Marc; Hubert, Jane; Brennand, Ana; Mazet, Muriel; Franconi, Jean‐Michel; Michels, Paul A.M.; Portais, Jean‐Charles; Boshart, Michael; Bringaud, Frédéric

doi:10.1074/jbc.m113.462978

Cited by 63 publications

(76 citation statements)

References 63 publications

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“…This finding was confirmed by a recent study showing that the overexpression of T. cruzi proline dehydrogenase led to resistance to hydrogen peroxide (51). In Trypanosoma brucei, proline was found to be involved in the cytosolic malic enzyme pathway responsible for oxidative stress management through cytosolic NADPH homeostasis (52). In L. donovani, it was shown that (i) proline is required for volume recovery during osmotic stress responses (53) and (ii) intracellular proline levels were increased in purine-starved cells (54).…”

Section: Discussionsupporting

confidence: 76%

Experimental Resistance to Drug Combinations in Leishmania donovani: Metabolic and Phenotypic Adaptations

Berg

García-Hernández

Cuypers

et al. 2015

Antimicrob Agents Chemother

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f Together with vector control, chemotherapy is an essential tool for the control of visceral leishmaniasis (VL), but its efficacy is jeopardized by growing resistance and treatment failure against first-line drugs. To delay the emergence of resistance, the use of drug combinations of existing antileishmanial agents has been tested systematically in clinical trials for the treatment of visceral leishmaniasis (VL). In vitro, Leishmania donovani promastigotes are able to develop experimental resistance to several combinations of different antileishmanial drugs after 10 weeks of drug pressure. Using an untargeted liquid chromatography-mass spectrometry (LC-MS) metabolomics approach, we identified metabolic changes in lines that were experimentally resistant to drug combinations and their respective single-resistant lines. This highlighted both collective metabolic changes (found in all combination therapy-resistant [CTR] lines) and specific ones (found in certain CTR lines). We demonstrated that single-resistant and CTR parasite cell lines show distinct metabolic adaptations, which all converge on the same defensive mechanisms that were experimentally validated: protection against drug-induced and external oxidative stress and changes in membrane fluidity. The membrane fluidity changes were accompanied by changes in drug uptake only in the lines that were resistant against drug combinations with antimonials, and surprisingly, drug accumulation was higher in these lines. Together, these results highlight the importance and the central role of protection against oxidative stress in the different resistant lines. Ultimately, these phenotypic changes might interfere with the mode of action of all drugs that are currently used for the treatment of VL and should be taken into account in drug development.

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Section: Discussionsupporting

confidence: 76%

Experimental Resistance to Drug Combinations in Leishmania donovani: Metabolic and Phenotypic Adaptations

Berg

García-Hernández

Cuypers

et al. 2015

Antimicrob Agents Chemother

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“…It is noteworthy that PPDK contribution to acetate production may be underestimated, because pyruvate can also be generated from malate produced in the glycosomes by the action of the cytosolic and mitochondrial malic enzymes (steps not indicated in Fig. 1A) (48). In the absence of PPDK, contribution of this pathway, as well as pyruvate kinase (step 18), to acetate production could increase.…”

Section: Resultsmentioning

confidence: 99%

Contribution of Pyruvate Phosphate Dikinase in the Maintenance of the Glycosomal ATP/ADP Balance in the Trypanosoma brucei Procyclic Form

Deramchia

Morand

Biran

et al. 2014

Journal of Biological Chemistry

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Background:The role of pyruvate phosphate dikinase (PPDK), which catalyzes a reversible reaction, is unknown in many eukaryotes. Results: Deletion of the trypanosomal PPDK gene affects glycolysis. Conclusion:In trypanosomes, PPDK works in the glycolytic direction and participates in the maintenance of the glycosomal ATP/ADP balance. Significance: The glycosomal PPDK provides a metabolic flexibility by producing 2 ATP per phosphoenolpyruvate consumed.

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“…PPP with 2 oxidoreductases in the oxidative branch is the major producer of cytoplasmic NADPH, essential for reduction of thiols and redox regulatory proteins (48). To decipher the essentiality of NADPH generated through PPP in maintaining cellular redox homeostasis 6-ANAD (a nicotinamide derivative) was administered with BSO along with oxidants to study the viability of promastigotes.…”

Section: Discussionmentioning

confidence: 99%

Metabolic reconfiguration of the central glucose metabolism: a crucial strategy ofLeishmania donovanifor its survival during oxidative stress

et al. 2015

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Understanding the mechanism that allows the intracellular protozoan parasite Leishmania donovani (Ld) to respond to reactive oxygen species (ROS) is of increasing therapeutic importance because of the continuing resistance toward antileishmanial drugs and for determining the illusive survival strategy of these parasites. A shift in primary carbon metabolism is the fastest response to oxidative stress. A 14 CO 2 evolution study, expression of glucose transporters together with consumption assays, indicated a shift in metabolic flux of the parasites from glycolysis toward pentose phosphate pathway (PPP) when exposed to different oxidants in vitro/ex vivo. Changes in gene expression, protein levels, and enzyme activities all pointed to a metabolic reconfiguration of the central glucose metabolism in response to oxidants. Generation of glucose-6-phosphate dehydrogenase (G6PDH) (∼5-fold) and transaldolase (TAL) (∼4.2-fold) overexpressing Ld cells reaffirmed that lethal doses of ROS were counterbalanced by effective manipulation of NADPH:NADP + ratio and stringent maintenance of reduced thiol content. The extent of protein carbonylation and accumulation of lipid peroxidized products were also found to be less in overexpressed cell lines. Interestingly, the LD 50 of sodium antimony gluconate (SAG), amphotericin-B (AmB), and miltefosine were significantly high toward overexpressing parasites. Consequently, this study illustrates that Ld strategizes a metabolic reconfiguration for replenishment of NADPH pool to encounter oxidative

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Cytosolic NADPH Homeostasis in Glucose-starved Procyclic Trypanosoma brucei Relies on Malic Enzyme and the Pentose Phosphate Pathway Fed by Gluconeogenic Flux

Cited by 63 publications

References 63 publications

Experimental Resistance to Drug Combinations in Leishmania donovani: Metabolic and Phenotypic Adaptations

Experimental Resistance to Drug Combinations in Leishmania donovani: Metabolic and Phenotypic Adaptations

Contribution of Pyruvate Phosphate Dikinase in the Maintenance of the Glycosomal ATP/ADP Balance in the Trypanosoma brucei Procyclic Form

Metabolic reconfiguration of the central glucose metabolism: a crucial strategy ofLeishmania donovanifor its survival during oxidative stress

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