title: Untargeted metabolomic analysis of miltefosine action in Leishmania infantum reveals changes to the internal lipid metabolism.
abstract: There are many theories as to the mode of action of miltefosine against Leishmania including alterations to the membrane lipid content, induction of apoptosis and modulation of macrophage responses. Here we perform untargeted metabolomics to elucidate the metabolic changes involved in miltefosine action. Over 800 metabolites were detected, 10% of which were significantly altered after 3.75 h. Many of the changes related to an increase in alkane fragment and sugar release. Fragment release is synchronised with reactive oxygen species production, but native membrane phospholipids remain intact. Signs of DNA damage were also detected as were changes to the levels of some thiols and polyamines. After 5 h of miltefosine treatment the cells showed depleted levels of most metabolites, indicating that the cells' outer membrane integrity had become compromised and internal metabolites were escaping upon cell death. In miltefosine resistant cells, the drug was not internalised and the changes to the internal metabolite levels were not seen. In contrast, cells resistant to antimony (SbIII) had similar corresponding alterations to the levels of internal metabolites as wild-type cells. A detailed knowledge of the mode of action of miltefosine will be important to inform the design of combination therapies to combat leishmaniasis, something that the research community should be prioritising in the coming years.
authors.affiliation: Centre de Recherche en Infectiologie, Université Laval, Québec, Canada.
authors.forename: Isabel M
authors.initials: IM
authors.lastname: Vincent
authors.affiliation: Glasgow Polyomics Facility, University of Glasgow, Glasgow, UK.
authors.forename: Stefan
authors.initials: S
authors.lastname: Weidt
authors.affiliation: Centro de Investigaciones Biológicas (CSIC), Madrid, Spain.
authors.forename: Luis
authors.initials: L
authors.lastname: Rivas
authors.affiliation: Glasgow Polyomics Facility, University of Glasgow, Glasgow, UK.
authors.forename: Karl
authors.initials: K
authors.lastname: Burgess
authors.affiliation: Schools of Biology & Chemistry, Biomedical Sciences Research Complex (BSRC), The North Haugh, The University, St. Andrews, UK.
authors.forename: Terry K
authors.initials: TK
authors.lastname: Smith
authors.affiliation: Centre de Recherche en Infectiologie, Université Laval, Québec, Canada.
authors.forename: Marc
authors.initials: M
authors.lastname: Ouellette
keywords: Leishmania; Metabolomics; Miltefosine; Mode of action