System-wide biochemical analysis reveals ozonide antimalarials initially act by disrupting Plasmodium falciparum haemoglobin digestion

PLoS Pathog. 2020 Jun 26;16(6):e1008485. doi: 10.1371/journal.ppat.1008485. eCollection 2020 Jun.

Abstract

Ozonide antimalarials, OZ277 (arterolane) and OZ439 (artefenomel), are synthetic peroxide-based antimalarials with potent activity against the deadliest malaria parasite, Plasmodium falciparum. Here we used a "multi-omics" workflow, in combination with activity-based protein profiling (ABPP), to demonstrate that peroxide antimalarials initially target the haemoglobin (Hb) digestion pathway to kill malaria parasites. Time-dependent metabolomic profiling of ozonide-treated P. falciparum infected red blood cells revealed a rapid depletion of short Hb-derived peptides followed by subsequent alterations in lipid and nucleotide metabolism, while untargeted peptidomics showed accumulation of longer Hb-derived peptides. Quantitative proteomics and ABPP assays demonstrated that Hb-digesting proteases were increased in abundance and activity following treatment, respectively. Ozonide-induced depletion of short Hb-derived peptides was less extensive in a drug-treated K13-mutant artemisinin resistant parasite line (Cam3.IIR539T) than in the drug-treated isogenic sensitive strain (Cam3.IIrev), further confirming the association between ozonide activity and Hb catabolism. To demonstrate that compromised Hb catabolism may be a primary mechanism involved in ozonide antimalarial activity, we showed that parasites forced to rely solely on Hb digestion for amino acids became hypersensitive to short ozonide exposures. Quantitative proteomics analysis also revealed parasite proteins involved in translation and the ubiquitin-proteasome system were enriched following drug treatment, suggestive of the parasite engaging a stress response to mitigate ozonide-induced damage. Taken together, these data point to a mechanism of action involving initial impairment of Hb catabolism, and indicate that the parasite regulates protein turnover to manage ozonide-induced damage.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adamantane / analogs & derivatives*
  • Adamantane / pharmacology
  • Antimalarials / pharmacology*
  • Erythrocytes* / metabolism
  • Erythrocytes* / parasitology
  • Hemoglobins / genetics
  • Hemoglobins / metabolism*
  • Heterocyclic Compounds / chemistry
  • Heterocyclic Compounds / pharmacology
  • Heterocyclic Compounds, 1-Ring / pharmacology*
  • Humans
  • Peroxides / pharmacology*
  • Plasmodium falciparum / genetics
  • Plasmodium falciparum / metabolism*
  • Proteomics
  • Spiro Compounds / pharmacology*

Substances

  • 1,2,4-trioxane
  • Antimalarials
  • Hemoglobins
  • Heterocyclic Compounds
  • Heterocyclic Compounds, 1-Ring
  • Peroxides
  • Spiro Compounds
  • arterolane
  • Adamantane
  • artefenomel

Grants and funding

Funding support was provided by the Australian National Health and Medical Research Council (NHMRC) project grants #APP1128003 to DJC, SAC and LE-M, and #APP1160705 and fellowship #APP1148700 to DJC. LE-M is funded by an Australian Research Council (ARC) Discovery Early Career Researcher Award (DECRA) Fellowship (DE180100418) and the Grimwade Fellowship funded by the Russell and Mab Grimwade Miegunyah Fund at the University of Melbourne. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.