Serotonin-induced stereospecific formation and bioactivity of the eicosanoid 17,18-epoxyeicosatetraenoic acid in the regulation of pharyngeal pumping of C. elegans.
17,18-EEQ
Caenorhabditis elegans
Chiral phase
Eicosanoids
Pharynx
Stereoisomers
Journal
Biochimica et biophysica acta. Molecular and cell biology of lipids
ISSN: 1879-2618
Titre abrégé: Biochim Biophys Acta Mol Cell Biol Lipids
Pays: Netherlands
ID NLM: 101731727
Informations de publication
Date de publication:
05 2023
05 2023
Historique:
received:
26
01
2023
revised:
21
02
2023
accepted:
22
02
2023
medline:
28
3
2023
pubmed:
14
3
2023
entrez:
13
3
2023
Statut:
ppublish
Résumé
17,18-Epoxyeicosatetraenoic acid (17,18-EEQ), the most abundant eicosanoid generated by cytochrome P450 (CYP) enzymes in C. elegans, is a potential signaling molecule in the regulation of pharyngeal pumping activity of this nematode. As a chiral molecule, 17,18-EEQ can exist in two stereoisomers, the 17(R),18(S)- and 17(S),18(R)-EEQ enantiomers. Here we tested the hypothesis that 17,18-EEQ may function as a second messenger of the feeding-promoting neurotransmitter serotonin and stimulates pharyngeal pumping and food uptake in a stereospecific manner. Serotonin treatment of wildtype worms induced a more than twofold increase of free 17,18-EEQ levels. As revealed by chiral lipidomics analysis, this increase was almost exclusively due to an enhanced release of the (R,S)-enantiomer of 17,18-EEQ. In contrast to the wildtype strain, serotonin failed to induce 17,18-EEQ formation as well as to accelerate pharyngeal pumping in mutant strains defective in the serotonin SER-7 receptor. However, the pharyngeal activity of the ser-7 mutant remained fully responsive to exogenous 17,18-EEQ administration. Short term incubations of well-fed and starved wildtype nematodes showed that both racemic 17,18-EEQ and 17(R),18(S)-EEQ were able to increase pharyngeal pumping frequency and the uptake of fluorescence-labeled microspheres, while 17(S),18(R)-EEQ and also 17,18-dihydroxyeicosatetraenoic acid (17,18-DHEQ, the hydrolysis product of 17,18-EEQ) were ineffective. Taken together, these results show that serotonin induces 17,18-EEQ formation in C. elegans via the SER-7 receptor and that both the formation of this epoxyeicosanoid and its subsequent stimulatory effect on pharyngeal activity proceed with high stereospecificity confined to the (R,S)-enantiomer.
Identifiants
pubmed: 36914111
pii: S1388-1981(23)00028-8
doi: 10.1016/j.bbalip.2023.159304
pii:
doi:
Substances chimiques
17,18-epoxy-5,8,11,14-eicosatetraenoic acid
131339-23-6
Serotonin
333DO1RDJY
Caenorhabditis elegans Proteins
0
Eicosanoids
0
Cytochrome P-450 Enzyme System
9035-51-2
Types de publication
Journal Article
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM
Pagination
159304Informations de copyright
Copyright © 2023 Elsevier B.V. All rights reserved.
Déclaration de conflit d'intérêts
Declaration of competing interest The authors declare no conflict of interest.