title: CYP-13A12 of the nematode Caenorhabditis elegans is a PUFA-epoxygenase involved in behavioural response to reoxygenation.
abstract: A specific behavioural response of Caenorhabditis elegans, the rapid increase of locomotion in response to anoxia/reoxygenation called the O2-ON response, has been used to model key aspects of ischaemia/reperfusion injury. A genetic suppressor screen demonstrated a direct causal role of CYP (cytochrome P450)-13A12 in this response and suggested that CYP-eicosanoids, which in mammals influence the contractility of cardiomyocytes and vascular smooth muscle cells, might function in C. elegans as specific regulators of the body muscle cell activity. In the present study we show that co-expression of CYP-13A12 with the NADPH-CYP-reductase EMB-8 in insect cells resulted in the reconstitution of an active microsomal mono-oxygenase system that metabolized EPA (eicosapentaenoic acid) and also AA (arachidonic acid) to specific sets of regioisomeric epoxy and hydroxy derivatives. The main products included 17,18-EEQ (17,18-epoxyeicosatetraenoic acid) from EPA and 14,15-EET (14,15-epoxyeicosatrienoic acid) from AA. Locomotion assays showed that the defective O2-ON response of C20-PUFA (polyunsaturated fatty acid)-deficient, Δ-12 and Δ-6 fatty acid desaturase mutants (fat-2 and fat-3 respectively) can be restored by feeding the nematodes AA or EPA, but not ETYA (eicosatetraynoic acid), a non-metabolizable AA analogue. Short-term incubation with 17,18-EEQ was sufficient to rescue the impaired locomotion of the fat-3 strain. The endogenous level of free 17,18-EEQ declined during anoxia and was rapidly restored in response to reoxygenation. On the basis of these results, we suggest that CYP-dependent eicosanoids such as 17,18-EEQ function as signalling molecules in the regulation of the O2-ON response in C. elegans. Remarkably, the exogenously administered 17,18-EEQ increased the locomotion activity under normoxic conditions and was effective not only with C20-PUFA-deficient mutants, but to a lesser extent also with wild-type worms.
authors.affiliation: *Humboldt-Universität zu Berlin, Department of Biology, Freshwater and Stress Ecology, Späthstr. 80/81, 12437 Berlin, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Keller
authors.affiliation: *Humboldt-Universität zu Berlin, Department of Biology, Freshwater and Stress Ecology, Späthstr. 80/81, 12437 Berlin, Germany.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Ellieva
authors.affiliation: †Department of Biology, MIT, Cambridge, MA 02139, U.S.A.
authors.forename: Dengke K
authors.initials: DK
authors.lastname: Ma
authors.affiliation: ‡Department of Occupational and Environmental Health, School of Public Health, Southeast University Nanjing, Nanjing, China.
authors.forename: Jingjuan
authors.initials: J
authors.lastname: Ju
authors.affiliation: *Humboldt-Universität zu Berlin, Department of Biology, Freshwater and Stress Ecology, Späthstr. 80/81, 12437 Berlin, Germany.
authors.forename: Erik
authors.initials: E
authors.lastname: Nehk
authors.affiliation: §Max Delbrück Center for Molecular Medicine, Robert-Rössle-Str. 10, 13125 Berlin, Germany.
authors.forename: Anne
authors.initials: A
authors.lastname: Konkel
authors.affiliation: ∥Department of Biochemistry, University of Texas Southwestern, Dallas, TX 75390, U.S.A.
authors.forename: John R
authors.initials: JR
authors.lastname: Falck
authors.affiliation: §Max Delbrück Center for Molecular Medicine, Robert-Rössle-Str. 10, 13125 Berlin, Germany.
authors.forename: Wolf-Hagen
authors.initials: WH
authors.lastname: Schunck
authors.affiliation: *Humboldt-Universität zu Berlin, Department of Biology, Freshwater and Stress Ecology, Späthstr. 80/81, 12437 Berlin, Germany.
authors.forename: Ralph
authors.initials: R
authors.lastname: Menzel
mesh_terms: D000818:Animals; D001095:Arachidonic Acids / Q000378:metabolism / Q000494:pharmacology; D017173:Caenorhabditis elegans; D029742:Caenorhabditis elegans Proteins / Q000096:biosynthesis*; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis*; D005231:Fatty Acids, Unsaturated / Q000096:biosynthesis*; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology*; D010084:Oxidation-Reduction / Q000187:drug effects
chemical_list: D001095:Arachidonic Acids; D029742:Caenorhabditis elegans Proteins; D005231:Fatty Acids, Unsaturated; C070378:17,18-epoxy-5,8,11,14-eicosatetraenoic acid; D003577:Cytochrome P-450 Enzyme System; C542332:cytochrome P-450 31A2, C elegans