Dynamics of sterol synthesis during development of Leishmania spp. parasites to their virulent form

Abstract

BackgroundThe Leishmania spp. protozoa, the causative agents of the “neglected” tropical disease leishmaniasis, are transmitted to mammals by sand fly vectors. Within the sand fly, parasites transform from amastigotes to procyclic promastigotes, followed by development of virulent (metacyclic) promastigote forms. The latter are infectious to mammalian hosts. Biochemical components localized in the parasite plasma membrane such as proteins and sterols play a pivotal role in Leishmania pathogenesis. Leishmania spp. lack the enzymes for cholesterol synthesis, and the dynamics of sterol acquisition and biosynthesis in parasite developmental stages are not understood. We hypothesized that dynamic changes in sterol composition during metacyclogenesis contribute to the virulence of metacyclic promastigotes.MethodsSterols were extracted from logarithmic phase or metacyclic promastigotes grown in liquid culture with or without cholesterol, and analyzed qualitatively and quantitatively by gas chromatograph-mass spectrometry (GC-MS). TriTrypDB was searched for identification of genes involved in Leishmania sterol biosynthetic pathways.ResultsIn total nine sterols were identified. There were dynamic changes in sterols during promastigote metacyclogenesis. Cholesterol in the culture medium affected sterol composition in different parasite stages. There were qualitative and relative quantitative differences between the sterol content of virulent versus avirulent parasite strains. A tentative sterol biosynthetic pathway in Leishmania spp. promastigotes was identified.ConclusionsSignificant differences in sterol composition were observed between promastigote stages, and between parasites exposed to different extracellular cholesterol in the environment. These data lay the foundation for further investigating the role of sterols in the pathogenesis of Leishmania spp. infections.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1470-0) contains supplementary material, which is available to authorized users.

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

“…4 , ergosterol levels were significantly reduced (approximately halved P = 5 × 10 −14 ) in the ΔLCB2 mutant relative to the wild type, while cholesterol levels were around 3-fold more abundant ( P = 8 × 10 −12 ). Cholesterol is probably scavenged in Leishmania species ( 26 ). Ergosterol was significantly increased with treatment in the wild type and was of much lower abundance in the mutant, which exhibits a 3-fold reduced sensitivity to the drug.…”

“…Substantial changes in sphingolipid (SL) and sterol metabolism were revealed in miltefosine-treated L. donovani promastigotes. SLs were first reported in L. donovani more than 20 years ago ( 25 ), and along with sterols, have since received attention in many species ( 26 – 28 ). Leishmania spp.…”

Leishmania dual‐specificity tyrosine‐regulated kinase 1 (DYRK1) is required for sustaining Leishmania stationary phase phenotype

“…This is less explainable for the parent cell line Lin DYRK1 −/− [pXNG‐ Lin DYRK1] but even in these cells some vacuolisation is visible. Conversely, the alteration in sterol composition may be entirely due to upregulation of the synthesis of some of endogenous ergostane‐based sterols, clearly visible in the putative terminal molecule of the pathway, ergosta‐7,24‐dien‐3β‐ol (Yao & Wilson, ).…”

“…Mass spectra were acquired from 50–550 amu. Identification was carried out by comparison of the retention times and fragmentation patterns with sterols in the NIST/EPA/NIH Mass Spectral Library and those reported in previous publications (Cauchetier et al, ; Fernandez‐Prada et al, ; Yao & Wilson, ). To examine changes in composition, the area under each sterol peak was used for relative quantification.…”

Sterol targeting drugs reveal life cycle stage-specific differences in trypanosome lipid rafts

“…Unlike T. brucei , the sterol synthetic machinery of T. cruzi and Leishmania are highly active in the mammalian host, making ergosterol targeting with Amp B to be a treatment options. As in T. brucei , the sterol composition in Leishmania and T. cruzi can be altered by modifying the available sterol in the environment/medium 87 , 88 . The presence of cholesta-5,7,24-trienol and ergosterol in the L. donovani membrane underlies the resistance of this organism to Amp B 89 .…”