title: H2O2 dynamics in the malaria parasite Plasmodium falciparum.
abstract: Hydrogen peroxide is an important antimicrobial agent but is also crucially involved in redox signaling and pathogen-host cell interactions. As a basis for systematically investigating intracellular H2O2 dynamics and regulation in living malaria parasites, we established the genetically encoded fluorescent H2O2 sensors roGFP2-Orp1 and HyPer-3 in Plasmodium falciparum. Both ratiometric redox probes as well as the pH control SypHer were expressed in the cytosol of blood-stage parasites. Both redox sensors showed reproducible sensitivity towards H2O2 in the lower micromolar range in vitro and in the parasites. Due to the pH sensitivity of HyPer-3, we used parasites expressing roGFP2-Orp1 for evaluation of short-, medium-, and long-term effects of antimalarial drugs on H2O2 levels and detoxification in Plasmodium. None of the quinolines or artemisinins tested had detectable direct effects on the H2O2 homeostasis at pharmacologically relevant concentrations. However, pre-treatment of the cells with antimalarial drugs or heat shock led to a higher tolerance towards exogenous H2O2. The systematic evaluation and comparison of the two genetically encoded cytosolic H2O2 probes in malaria parasites provides a basis for studying parasite-host cell interactions or drug effects with spatio-temporal resolution while preserving cell integrity.
authors.affiliation: Biochemistry and Molecular Biology, Interdisciplinary Research Center, Justus Liebig University Giessen, Giessen, Hessen, Germany.
authors.forename: Mahsa
authors.initials: M
authors.lastname: Rahbari
authors.affiliation: Biochemistry and Molecular Biology, Interdisciplinary Research Center, Justus Liebig University Giessen, Giessen, Hessen, Germany.
authors.forename: Stefan
authors.identifier: http://orcid.org/0000-0003-4412-9925
authors.initials: S
authors.lastname: Rahlfs
authors.affiliation: Biochemistry and Molecular Biology, Interdisciplinary Research Center, Justus Liebig University Giessen, Giessen, Hessen, Germany.
authors.forename: Esther
authors.identifier: http://orcid.org/0000-0003-3408-8672
authors.initials: E
authors.lastname: Jortzik
authors.affiliation: Molecular Physiology, Institute of Cardiovascular Physiology, University Medical Center, Georg August University Göttingen, Göttingen, Niedersachsen, Germany.
authors.forename: Ivan
authors.initials: I
authors.lastname: Bogeski
authors.affiliation: Biochemistry and Molecular Biology, Interdisciplinary Research Center, Justus Liebig University Giessen, Giessen, Hessen, Germany.
authors.forename: Katja
authors.identifier: http://orcid.org/0000-0003-4673-3675
authors.initials: K
authors.lastname: Becker
mesh_terms: D000962:Antimalarials / Q000494:pharmacology*; D015153:Blotting, Western; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism; D004912:Erythrocytes / Q000187:drug effects / Q000469:parasitology / Q000502:physiology; D004926:Escherichia coli; D006401:Hematologic Agents / Q000494:pharmacology; D006706:Homeostasis / Q000187:drug effects; D006358:Hot Temperature; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D018613:Microscopy, Confocal; D010084:Oxidation-Reduction / Q000187:drug effects; D010963:Plasmodium falciparum / Q000187:drug effects* / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D012503:Saponins / Q000494:pharmacology; D014162:Transfection
chemical_list: D000962:Antimalarials; D006401:Hematologic Agents; D011994:Recombinant Proteins; D012503:Saponins; D006861:Hydrogen Peroxide