title: Differential gene expression analysis in antimony-unresponsive Indian kala azar (visceral leishmaniasis) clinical isolates by DNA microarray.
abstract: In this study, cDNA microarray analysis of a closely related species, Leishmania major, was used as a screening tool to compare antimonial-resistant and susceptible clinical isolates of Leishmania donovani in order to to identify candidate genes on the basis of antimony resistance. Clinically confirmed resistant isolate 39 and sensitive isolate 2001 were used in this study. Many differentially regulated genes were identified whose expression levels differ in sodium antimony gluconate (SAG)-treated patients. Interestingly, genes on the array, showing changes in expression of over 2-fold revealed the identity of ABC transporters, which are known determinants of drug resistance in laboratory mutants. The functionality of the transporters was validated by flow cytometry which, being biologically informative, provides direct clues to gene function. The results suggest that isolate 39 could have developed resistance by an increased multidrug resistance protein (MRP)-like pump. This study provides preliminary clues to the role of a thiol-dependent efflux system in antimonial resistant clinical isolates of Leishmania donovani.
authors.affiliation: Central Drug Research Institute, Lucknow, India. neeloo888@yahoo.com
authors.forename: N
authors.initials: N
authors.lastname: Singh
authors.forename: R
authors.initials: R
authors.lastname: Almeida
authors.forename: H
authors.initials: H
authors.lastname: Kothari
authors.forename: P
authors.initials: P
authors.lastname: Kumar
authors.forename: G
authors.initials: G
authors.lastname: Mandal
authors.forename: M
authors.initials: M
authors.lastname: Chatterjee
authors.forename: S
authors.initials: S
authors.lastname: Venkatachalam
authors.forename: M K
authors.initials: MK
authors.lastname: Govind
authors.forename: S K
authors.initials: SK
authors.lastname: Mandal
authors.forename: S
authors.initials: S
authors.lastname: Sundar
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics; D000818:Animals; D000967:Antimony Sodium Gluconate / Q000494:pharmacology; D015152:Blotting, Northern; D019295:Computational Biology; D004351:Drug Resistance / Q000235:genetics*; D005434:Flow Cytometry; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D017125:Genes, Protozoan / Q000235:genetics*; D006801:Humans; D007893:Leishmania donovani / Q000187:drug effects* / Q000235:genetics* / Q000378:metabolism; D018320:Leishmania major / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D007898:Leishmaniasis, Visceral / Q000469:parasitology*; D020411:Oligonucleotide Array Sequence Analysis; D013438:Sulfhydryl Compounds / Q000378:metabolism
chemical_list: D018528:ATP-Binding Cassette Transporters; D013438:Sulfhydryl Compounds; D000967:Antimony Sodium Gluconate