title: Differential gene expression in Trypanosoma cruzi populations susceptible and resistant to benznidazole.
abstract: Differential gene expression in three pairs of Trypanosoma cruzi populations or clones susceptible or resistant to benznidazole (BZ) was investigated by differential display (DD) and representation of differential expression (RDE). GenBank searches of 14 genes selected by DD showed that four sequences corresponded to different hypothetical proteins and the others were very similar to T. cruzi genes encoding mucin (TcMUC), dihydrolipoamide dehydrogenase (TcLipDH), the hexose transporter (TcHT), or a ribosomal protein. Sequence analysis was performed on 34 clones obtained by RDE; approximately half of these clones encoded 14 different hypothetical proteins and the other half encoded proteins involved with stress response, antioxidant defence, metabolism, transporter proteins, surface proteins, ribosomal proteins and others. The mRNA levels of eight T. cruzi genes obtained by RDE and DD were analysed by northern blotting to confirm the differential expression of these sequences. For six of the eight genes, TcLipDH, TcHT, TcFeSOD-A (iron superoxide dismutase-A), TcHSP70, TcHSP100 (heat shock protein) and Tc52 (thiol-transferase), mRNA levels in the drug-resistant T. cruzi population were at least twice those in the susceptible population. Further analysis of TcHSP70 showed that although the levels of TcHSP70 mRNA were four-fold higher in T. cruzi BZ-resistant population, no corresponding increase was observed in the levels of TcHSP70 protein expression. The results suggest that TcHSP70 is not directly associated with the T. cruzi drug resistance phenotype.
authors.affiliation: Laboratório de Parasitologia Celular e Molecular, Centro de Pesquisas René Rachou, FIOCRUZ, Av. Augusto de Lima 1715, Caixa Postal 1743, CEP 30190-002, Belo Horizonte, MG, Brazil. smurta@yahoo.com
authors.forename: Silvane M F
authors.initials: SM
authors.lastname: Murta
authors.forename: Fernanda B
authors.initials: FB
authors.lastname: Nogueira
authors.forename: Paula F
authors.initials: PF
authors.lastname: Dos Santos
authors.forename: Fernanda M F
authors.initials: FM
authors.lastname: Campos
authors.forename: Caroline
authors.initials: C
authors.lastname: Volpe
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Liarte
authors.forename: Philippe
authors.initials: P
authors.lastname: Nirdé
authors.forename: Christian M
authors.initials: CM
authors.lastname: Probst
authors.forename: Marco A
authors.initials: MA
authors.lastname: Krieger
authors.forename: Samuel
authors.initials: S
authors.lastname: Goldenberg
authors.forename: Alvaro J
authors.initials: AJ
authors.lastname: Romanha
mesh_terms: D000818:Animals; D000962:Antimalarials / Q000494:pharmacology*; D015152:Blotting, Northern; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D004351:Drug Resistance; D020869:Gene Expression Profiling; D017125:Genes, Protozoan; D008969:Molecular Sequence Data; D009593:Nitroimidazoles / Q000494:pharmacology*; D015800:Protozoan Proteins / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D016053:RNA, Protozoan / Q000096:biosynthesis / Q000235:genetics; D017422:Sequence Analysis, DNA; D014349:Trypanosoma cruzi / Q000187:drug effects / Q000235:genetics*
chemical_list: D000962:Antimalarials; D016054:DNA, Protozoan; D009593:Nitroimidazoles; D015800:Protozoan Proteins; D012333:RNA, Messenger; D016053:RNA, Protozoan; C009999:benzonidazole