title: Role of the ABC transporter MRPA (PGPA) in antimony resistance in Leishmania infantum axenic and intracellular amastigotes.
abstract: Antimonial compounds are the mainstay for the treatment of infections with the protozoan parasite Leishmania. We present our studies on Leishmania infantum amastigote parasites selected for resistance to potassium antimonyl tartrate [Sb(III)]. Inside macrophages, the Sb(III)-selected cells are cross-resistant to sodium stibogluconate (Pentostam), the main drug used against Leishmania. Putative alterations in the level of expression of more than 40 genes were compared between susceptible and resistant axenic amastigotes using customized DNA microarrays. The expression of three genes coding for the ABC transporter MRPA (PGPA), S-adenosylhomocysteine hydrolase, and folylpolyglutamate synthase was found to be consistently increased. The levels of cysteine were found to be increased in the mutant. Transfection of the MRPA gene was shown to confer sodium stibogluconate resistance in intracellular parasites. This MRPA-mediated resistance could be reverted by using the glutathione biosynthesis-specific inhibitor buthionine sulfoximine. These results highlight for the first time the role of MRPA in antimony resistance in the amastigote stage of the parasite and suggest a strategy for reversing resistance.
authors.affiliation: Centre de Recherche en Infectiologie du Centre de Recherche du CHUL, Iniversité Laval, Québec, Canada G1V 4G2.
authors.forename: Karima
authors.initials: K
authors.lastname: El Fadili
authors.forename: Nadine
authors.initials: N
authors.lastname: Messier
authors.forename: Philippe
authors.initials: P
authors.lastname: Leprohon
authors.forename: Gaétan
authors.initials: G
authors.lastname: Roy
authors.forename: Chantal
authors.initials: C
authors.lastname: Guimond
authors.forename: Nathalie
authors.initials: N
authors.lastname: Trudel
authors.forename: Nancy G
authors.initials: NG
authors.lastname: Saravia
authors.forename: Barbara
authors.initials: B
authors.lastname: Papadopoulou
authors.forename: Danielle
authors.initials: D
authors.lastname: Légaré
authors.forename: Marc
authors.initials: M
authors.lastname: Ouellette
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000378:metabolism*; D000818:Animals; D000965:Antimony / Q000494:pharmacology*; D000967:Antimony Sodium Gluconate / Q000494:pharmacology; D002460:Cell Line; D003545:Cysteine / Q000378:metabolism; D016054:DNA, Protozoan / Q000096:biosynthesis / Q000235:genetics; D004351:Drug Resistance; D005978:Glutathione / Q000031:analogs & derivatives* / Q000378:metabolism; D018314:Leishmania infantum / Q000187:drug effects* / Q000254:growth & development; D008562:Membrane Glycoproteins / Q000378:metabolism*; D018613:Microscopy, Confocal; D009000:Monocytes / Q000187:drug effects; D020411:Oligonucleotide Array Sequence Analysis; D015800:Protozoan Proteins / Q000378:metabolism*; D012261:Ribonucleoproteins / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics; D013095:Spermidine / Q000031:analogs & derivatives* / Q000378:metabolism; D014162:Transfection
chemical_list: D018528:ATP-Binding Cassette Transporters; D016054:DNA, Protozoan; D008562:Membrane Glycoproteins; C106891:PgpA protein, Leishmania; D015800:Protozoan Proteins; D012261:Ribonucleoproteins; D029701:Saccharomyces cerevisiae Proteins; C476348:Thp1 protein, S cerevisiae; C044809:trypanothione; D000965:Antimony; D005978:Glutathione; D003545:Cysteine; D013095:Spermidine; D000967:Antimony Sodium Gluconate