Complex Interplay between Sphingolipid and Sterol Metabolism Revealed by Perturbations to the Leishmania Metabolome Caused by Miltefosine

Abstract

With the World Health Organization reporting over 30,000 deaths and 200,000 to 400,000 new cases annually, visceral leishmaniasis is a serious disease affecting some of the world's poorest people. As drug resistance continues to rise, there is a huge unmet need to improve treatment. Miltefosine remains one of the main treatments for leishmaniasis, yet its mode of action (MoA) is still unknown. Understanding the MoA of this drug and parasite response to treatment could help pave the way for new and more successful treatments for leishmaniasis. A novel method has been devised to study the metabolome and lipidome of Leishmania donovani axenic amastigotes treated with miltefosine. Miltefosine caused a dramatic decrease in many membrane phospholipids (PLs), in addition to amino acid pools, while sphingolipids (SLs) and sterols increased. Leishmania major promastigotes devoid of SL biosynthesis through loss of the serine palmitoyl transferase gene (ΔLCB2) were 3-fold less sensitive to miltefosine than wild-type (WT) parasites. Changes in the metabolome and lipidome of miltefosine-treated L. major mirrored those of L. donovani. A lack of SLs in the ΔLCB2 mutant was matched by substantial alterations in sterol content. Together, these data indicate that SLs and ergosterol are important for miltefosine sensitivity and, perhaps, MoA.

Lopinavir, an HIV-1 peptidase inhibitor, induces alteration on the lipid metabolism ofLeishmania amazonensispromastigotes

“…Sterol biosynthesis inhibitors have been widely studied in Leishmania spp., particularly because this pathway is a promising target for antiprotozoal chemotherapy (Rodrigues et al , 2002 ; Magaraci et al , 2003 ; Chawla and Madhubala, 2010 ; de Macedo-Silva et al , 2015 ; Andrade-Neto et al , 2016 ). In this regard, the mode of action of miltefosine on Leishmania lipid metabolism has been recently deeply investigated (Armitage et al , 2018 ). Miltefosine also induces apoptosis-like death and the disruption of metabolite transport.…”

“…Miltefosine also induces apoptosis-like death and the disruption of metabolite transport. It is possible that these two mechanisms are linked to an interference in the lipid metabolism (Armitage et al , 2018 ). Leishmania treated with miltefosine presented a dramatic decrease in many membrane phospholipids, in addition to amino acid pools, while sphingolipids and sterols increased.…”

“…It is also interesting that the analysis of a mutant of Leishmania major that lacks the first and rate-limiting enzyme of the biosynthetic pathway of sphingolipids revealed a three times lower susceptibility to miltefosine, while the drug intracellular concentration presented no significant difference in relative concentration in relation to wild-type cells. The increase in the sphingolipid content reported may be related to either a stimulatory effect of miltefosine on the biosynthesis itself or to the inhibition of a catabolic pathway, the latter more probable, since the mutant cells also presented an increase in sphingolipids (Armitage et al ., 2018 ).…”

An investigation of the antileishmanial properties of semi-synthetic saponins

“…[87][88][89][90] Mass spectrometry-based metabolomics has been applied to investigate this for both clinical drugs and experimental natural compounds, although the results of these studies can be difficult to interpret. 28,91 Notably all but one, the natural cyclic peptide amphotericin B, of the current clinical anti-leishmanials lacks a well-defined mechanism of action. 16,91 Mammalian cells harbour cholesterol as the primary sterol, in contrast fungi and Leishmania spp possess ergosterol.…”

A BONCAT-iTRAQ method enables temporally resolved quantitative profiling of newly synthesised proteins in Leishmania mexicana parasites during starvation

“…[56], indicating its possible role in drug resistance. Several studies indicate that there is a complex interplay between the stress responses and drug resistance in the Leishmania parasites [57][58][59]. Other potentially important therapeutically relevant proteins include the mitogen activated protein kinase 10 (Gene ID: LmxM.10.0200) and the cell division protein kinase 2 (Gene ID: LmxM.21.1080); the former has been reported to be stage-specifically regulated in Leishmania with its kinase activity increasing from promastigote to amastigote conversion [60] and the latter is a protein kinase that acts as a crucial regulator of cell division cycle in the parasite [61].…”