title: Regulation of GPR55 in rat white adipose tissue and serum LPI by nutritional status, gestation, gender and pituitary factors.
abstract: The G protein-coupled receptor GPR55 has been proposed as a new cannabinoid receptor associated with obesity in humans. We have investigated the regulation of GPR55 in rat white adipose tissue (WAT) in different physiological and pathophysiological settings involved in energy balance. We compared GPR55 expression with Cannabinoid Receptor type 1 (CB1), which mediates the metabolic actions of endocannabinoids, by real time PCR and western blotting. Circulating levels of lysophosphatidylinositol (LPI), the endogenous ligand of GPR55, were measured by liquid chromatography-mass spectrometry. Both WAT CB1 and GPR55 levels were increased after fasting and recovered after leptin treatment. Their expression was decreased during gestation and increased throughout lifespan. Orchidectomy diminished WAT CB1 and GPR55 expression whereas ovariectomized rats showed increased GPR55 but decreased CB1 levels. Alterations in pituitary functions also modified WAT CB1 and GPR55 levels. Serum LPI levels were inversely regulated by fasting and gonadectomy in comparison to WAT GPR55. Our findings indicate that GPR55 and LPI are regulated by different physiological and pathophysiological settings known to be associated with marked alterations in energy status.
authors.affiliation: Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela 15706, Spain.
authors.forename: Monica
authors.initials: M
authors.lastname: Imbernon
authors.affiliation: Department of Pharmacology and Toxicology, University of Toronto, Toronto M5S 1A8, Canada.
authors.forename: Lauren
authors.initials: L
authors.lastname: Whyte
authors.affiliation: Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela 15706, Spain.
authors.forename: Adenis
authors.initials: A
authors.lastname: Diaz-Arteaga
authors.affiliation: Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen AB21 9SB, UK.
authors.forename: Wendy R
authors.initials: WR
authors.lastname: Russell
authors.affiliation: CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela 15706, Spain; Department of Cell Biology, Physiology and Immunology, Instituto Maimónides de Investigaciones Biomédicas (IMIBIC)/Hospital Universitario Reina Sofia/University of Cordoba, 14004 Córdoba, Spain.
authors.forename: Natalia R
authors.initials: NR
authors.lastname: Moreno
authors.affiliation: Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela 15706, Spain.
authors.forename: María J
authors.initials: MJ
authors.lastname: Vazquez
authors.affiliation: Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela 15706, Spain.
authors.forename: Carmen R
authors.initials: CR
authors.lastname: Gonzalez
authors.affiliation: CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela 15706, Spain; Department of Cell Biology, Physiology and Immunology, Instituto Maimónides de Investigaciones Biomédicas (IMIBIC)/Hospital Universitario Reina Sofia/University of Cordoba, 14004 Córdoba, Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: Díaz-Ruiz
authors.affiliation: Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela 15706, Spain.
authors.forename: Miguel
authors.initials: M
authors.lastname: Lopez
authors.affiliation: CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela 15706, Spain; Department of Cell Biology, Physiology and Immunology, Instituto Maimónides de Investigaciones Biomédicas (IMIBIC)/Hospital Universitario Reina Sofia/University of Cordoba, 14004 Córdoba, Spain.
authors.forename: Maria M
authors.initials: MM
authors.lastname: Malagón
authors.affiliation: Department of Pharmacology and Toxicology, University of Toronto, Toronto M5S 1A8, Canada.
authors.forename: Ruth A
authors.initials: RA
authors.lastname: Ross
authors.affiliation: Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela 15706, Spain. Electronic address: carlos.dieguez@usc.es.
authors.forename: Carlos
authors.initials: C
authors.lastname: Dieguez
authors.affiliation: Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela 15706, Spain. Electronic address: ruben.nogueiras@usc.es.
authors.forename: Ruben
authors.initials: R
authors.lastname: Nogueiras
mesh_terms: D052436:Adipose Tissue, White / Q000187:drug effects / Q000378:metabolism*; D000367:Age Factors; D000818:Animals; D004734:Energy Metabolism; D005215:Fasting; D005260:Female; D005786:Gene Expression Regulation; D005865:Gestational Age; D020738:Leptin / Q000494:pharmacology; D008246:Lysophospholipids / Q000097:blood*; D008297:Male; D009752:Nutritional Status / Q000235:genetics*; D009919:Orchiectomy; D010052:Ovariectomy; D010902:Pituitary Gland / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D043884:Receptor, Cannabinoid, CB1 / Q000235:genetics* / Q000378:metabolism; D043882:Receptors, Cannabinoid / Q000235:genetics* / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled / Q000235:genetics* / Q000378:metabolism; D012737:Sex Factors
chemical_list: C568825:GPR55 protein, rat; D020738:Leptin; D008246:Lysophospholipids; D043884:Receptor, Cannabinoid, CB1; D043882:Receptors, Cannabinoid; D043562:Receptors, G-Protein-Coupled; C025449:lysophosphatidylinositol
keywords: CB1; Endocannabinoids; GPR55; LPI; Nutritional status; White adipose tissue