Revealing metabolic actions of novel compounds against African trypanosomes by high resolution mass spectrometry — ASN Events
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  2. Symposium Four: Students of APS (SoAPS)
  3. Revealing metabolic actions of novel compounds against African trypanosomes by high resolution mass spectrometry

Revealing metabolic actions of novel compounds against African trypanosomes by high resolution mass spectrometry (#15)

Daniel Stoessel 1 , Cameron J Nowell 2 , Katherine M Ellis 1 , Malcolm J McConville 3 , Jonathan Baell 4 , Darren J Creek 1
  1. Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Melbourne
  2. Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Melbourne
  3. Biochemistry and Molecular Biology , Bio 21 Molecular Science and Biotechnology , Melbourne
  4. Medicinal Chemistry, Monash Insitute of Pharmaceutical Sciences, Melbourne

Trypanosoma brucei causes human African trypanosomiasis (HAT), which is transmitted by a bite of the Testse fly. This disease causes significant disability and is fatal for around ten thousand people every year. The armory of medication for HAT is outdated and the development of resistance, high toxicity and treatment costs are ongoing problems. High throughput screening of approximately 87,000 compounds against T. brucei identified a novel compound 3-(Oxazolo[4,5-b]pyridine-2-yl)anilide (OXPA) which shows high activity against this organism and minimal toxicity to mammalian cells. The aim of this study was to determine the biochemical actions of this compound in T. brucei.
Metabolomics with HILIC/RP-chromatography in combination with high resolution mass spectrometry was applied to in vitro cell cultures of T. brucei treated with this novel compound. The investigation of polar metabolites with untargeted HILIC metabolomics analysis suggested that this potential drug perturbed carnitine uptake, trypanosome-specific NADH-fumarate reductase, trans-sialidase and 6-phosphoglucolactonase. The most interesting finding was the accumulation of several ceramides, which play an important role in cell signaling and the synthesis of sphingolipids in the parasite. In order to understand changes in the lipidome of the parasite in more detail a new lipidomics method was developed which enables the identification of hundreds of lipids with high throughput and sufficient reproducibility. The application of this novel method in an untargeted analysis identified 600 lipids in the parasite indicating that the lipidome of T. brucei mainly consists of glycerophospholipids, sphingolipids and fatty acyls. Interestingly, this analysis confirmed extensive ceramide accumulation in the parasite due to treatment with the novel compound OXPA.
This study strongly suggests that OXPA interacts with the sphingolipid pathway in T. brucei, most likely by inhibiting the parasitic sphingolipid synthase, which has been validated as a potential drug target in previous studies.