title: Apoptotic marker expression in the absence of cell death in staurosporine-treated Leishmania donovani.
abstract: The protozoan parasite Leishmania donovani undergoes several developmental transitions in its insect and vertebrate hosts that are induced by environmental changes. The roles of protein kinases in these adaptive differentiation steps and their potential as targets for antiparasitic intervention are only poorly characterized. Here, we used the generic protein kinase inhibitor staurosporine to gain insight into how interference with phosphotransferase activities affects the viability, growth, and motility of L. donovani promastigotes in vitro. Unlike the nonkinase drugs miltefosine and amphotericin B, staurosporine strongly reduced parasite biosynthetic activity and had a cytostatic rather than a cytotoxic effect. Despite the induction of a number of classical apoptotic markers, including caspase-like activity and surface binding of annexin V, we determined that, on the basis of cellular integrity, staurosporine did not cause cell death but caused cell cycle arrest and abrogated parasite motility. In contrast, targeted inhibition of the parasite casein kinase 1 (CK1) protein family by use of the CK1-specific inhibitor D4476 resulted in cell death. Thus, pleiotropic inhibition of L. donovani protein kinases and possibly other ATP-binding proteins by staurosporine dissociates apoptotic marker expression from cell death, which underscores the relevance of specific rather than broad kinase inhibitors for antiparasitic drug development.
authors.affiliation: Institut Pasteur CNRS URA2581, Unité de Parasitology Moléculaire et Signalisation, Paris, France.
authors.forename: Aude L
authors.initials: AL
authors.lastname: Foucher
authors.forename: Najma
authors.initials: N
authors.lastname: Rachidi
authors.forename: Sarah
authors.initials: S
authors.lastname: Gharbi
authors.forename: Thierry
authors.initials: T
authors.lastname: Blisnick
authors.forename: Philippe
authors.initials: P
authors.lastname: Bastin
authors.forename: Iain K
authors.initials: IK
authors.lastname: Pemberton
authors.forename: Gerald F
authors.initials: GF
authors.lastname: Späth
mesh_terms: D000595:Amino Acid Sequence; D000666:Amphotericin B / Q000737:chemistry / Q000494:pharmacology; D017304:Annexin A5; D000981:Antiprotozoal Agents / Q000737:chemistry / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D001549:Benzamides / Q000737:chemistry / Q000494:pharmacology; D015415:Biomarkers / Q000378:metabolism; D047389:Casein Kinase I / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism; D059447:Cell Cycle Checkpoints / Q000187:drug effects; D006801:Humans; D007093:Imidazoles / Q000737:chemistry / Q000494:pharmacology; D007893:Leishmania donovani / Q000187:drug effects* / Q000201:enzymology / Q000254:growth & development; D008969:Molecular Sequence Data; D010767:Phosphorylcholine / Q000031:analogs & derivatives / Q000737:chemistry / Q000494:pharmacology; D010770:Phosphotransferases / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism; D014176:Protein Biosynthesis / Q000187:drug effects; D047428:Protein Kinase Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D015800:Protozoan Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism; D019311:Staurosporine / Q000737:chemistry / Q000494:pharmacology*; D013379:Substrate Specificity
chemical_list: C493177:4-(4-(2,3-dihydrobenzo(1,4)dioxin-6-yl)-5-pyridin-2-yl-1H-imidazol-2-yl)benzamide; D017304:Annexin A5; D000981:Antiprotozoal Agents; D001549:Benzamides; D015415:Biomarkers; D007093:Imidazoles; D047428:Protein Kinase Inhibitors; D015800:Protozoan Proteins; D010767:Phosphorylcholine; C039128:miltefosine; D000666:Amphotericin B; D010770:Phosphotransferases; D047389:Casein Kinase I; D019311:Staurosporine