title: Des-Acyl Ghrelin Directly Targets the Arcuate Nucleus in a Ghrelin-Receptor Independent Manner and Impairs the Orexigenic Effect of Ghrelin.
abstract: Ghrelin is a stomach-derived octanoylated peptide hormone that plays a variety of well-established biological roles acting via its specific receptor known as growth hormone secretagogue receptor (GHSR). In plasma, a des-octanoylated form of ghrelin, named des-acyl ghrelin (DAG), also exists. DAG is suggested to be a signalling molecule that has specific targets, including the brain, and regulates some physiological functions. However, no specific receptor for DAG has been reported until now, and, consequently, the potential role of DAG as a hormone has remained a matter of debate. In the present study, we show that DAG specifically binds to and acts on a subset of arcuate nucleus (ARC) cells in a GHSR-independent manner. ARC cells labelled by a DAG fluorescent tracer include the neuropeptide Y (NPY) and non-NPY neurones. Given the well-established role of the ARC in appetite regulation, we tested the effect of centrally administered DAG on food intake. We found that DAG failed to affect dark phase feeding, as well as food intake, after a starvation period; however, it impaired the orexigenic actions of peripherally administered ghrelin. Thus, we conclude that DAG directly targets ARC neurones and antagonises the orexigenic effects of peripherally administered ghrelin.
authors.affiliation: Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology, [IMBICE dependent on the Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA)], La Plata, Buenos Aires, Argentina.
authors.forename: G
authors.initials: G
authors.lastname: Fernandez
authors.affiliation: Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology, [IMBICE dependent on the Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA)], La Plata, Buenos Aires, Argentina.
authors.forename: A
authors.initials: A
authors.lastname: Cabral
authors.affiliation: Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology, [IMBICE dependent on the Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA)], La Plata, Buenos Aires, Argentina.
authors.forename: M P
authors.initials: MP
authors.lastname: Cornejo
authors.affiliation: Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology, [IMBICE dependent on the Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA)], La Plata, Buenos Aires, Argentina.
authors.forename: P N
authors.identifier: http://orcid.org/0000-0003-4226-7507
authors.initials: PN
authors.lastname: De Francesco
authors.affiliation: Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology, [IMBICE dependent on the Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA)], La Plata, Buenos Aires, Argentina.
authors.forename: G
authors.initials: G
authors.lastname: Garcia-Romero
authors.affiliation: Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology, [IMBICE dependent on the Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA)], La Plata, Buenos Aires, Argentina.
authors.forename: M
authors.initials: M
authors.lastname: Reynaldo
authors.affiliation: Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology, [IMBICE dependent on the Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA)], La Plata, Buenos Aires, Argentina.
authors.forename: M
authors.initials: M
authors.lastname: Perello
mesh_terms: D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000378:metabolism*; D004435:Eating / Q000187:drug effects / Q000502:physiology*; D054439:Ghrelin / Q000008:administration & dosage / Q000037:antagonists & inhibitors* / Q000494:pharmacology / Q000502:physiology; D057967:Infusions, Intraventricular; D007279:Injections, Subcutaneous; D018345:Mice, Knockout; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D054440:Receptors, Ghrelin / Q000235:genetics / Q000502:physiology*
chemical_list: D054439:Ghrelin; D054440:Receptors, Ghrelin; C422650:ghrelin, des-n-octanoyl
keywords: acyl-ghrelin; des-acyl ghrelin receptor; food intake; hypothalamus