CYP-13A12 of the nematode Caenorhabditis elegans is a PUFA-epoxygenase involved in behavioural response to reoxygenation

Julia Keller, Alexandra Ellieva, Dengke K. Ma, Jingjuan Ju, Erik Nehk, Anne Konkel, John R. Falck, Wolf Hagen Schunck, Ralph Menzel

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5 Scopus citations

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. Shortterm 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-PUFAdeficient mutants, but to a lesser extent alsowith wild-typeworms.

Original languageEnglish (US)
Pages (from-to)61-71
Number of pages11
JournalBiochemical Journal
Volume464
DOIs
Publication statusPublished - Nov 15 2014

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Keywords

  • 17,18-epoxyeicosatetraenoic acid (17,18-EEQ)
  • Caenorhabditis elegans
  • Cytochrome P450
  • Eicosanoid
  • Polyunsaturated fatty acid
  • Reoxygenation

ASJC Scopus subject areas

  • Biochemistry
  • Cell Biology
  • Molecular Biology

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