title: Expression and regulation of INTELECTIN1 in human granulosa-lutein cells: role in IGF-1-induced steroidogenesis through NAMPT.
abstract: INTELECTIN (ITLN) is an adipokine involved in the regulation of insulin sensitivity and inflammatory and immunity responses. Serum ITLN levels are lower in obese, diabetic, and polycystic ovary syndrome (PCOS) women than in control subjects. ITLN has never been studied in ovarian cells. Here, we identified ITLN1 in human ovarian follicles and investigated the molecular mechanisms involved in the regulation of its expression in response to the insulin sensitizers metformin and rosiglitazone, in human granulosa-lutein cells (hGLCs) and in a human ovarian granulosa-like tumor cell line (KGN). We also studied the effects of human recombinant ITLN1 (hRom1) on steroid production and on the activation of various signaling pathways. Using RT-PCR, immunoblotting, and immunohistochemistry, we found that INTL1 is present in human follicular cells. Using ELISA, we showed that INTL levels are similar in plasma and follicular fluid (FF) in control patients, whereas they are higher in FF than in plasma in PCOS patients. In KGN cells and hGLCs, insulin (10(-8) M), insulin-like growth factor-1 (IGF-1; 10(-8) M), and metformin (10(-2) M or 10(-3) M) increased INTL1 expression (mRNA and protein) after 12 and 24 h of stimulation. For metformin, this effect was mediated by adenosine monophosphate-activated kinase (PRKA). Furthermore, hRom1 increased nicotinamide phosphoribosyltransferase (NAMPT) expression in KGN and hGLCs. We also showed that hRom1 increased IGF-1-induced progesterone and estradiol secretion and this was associated with an increase in the STAR and CYP19A1 protein levels and an increase in IGF-1R signaling. Furthermore, all these data were abolished when NAMPT was knocked down in KGN cells, suggesting that INTL1 improves IGF-1-induced steroidogenesis through induction of NAMPT in hGLCs.
authors.affiliation: UMR 7247 INRA-CNRS-Université de Tours-Haras Nationaux, Nouzilly, France Unité d'Endocrinologie Nutrition Diabète, CHRU de Tours, Tours, France.
authors.forename: Lucie
authors.initials: L
authors.lastname: Cloix
authors.affiliation: UMR 7247 INRA-CNRS-Université de Tours-Haras Nationaux, Nouzilly, France.
authors.forename: Maxime
authors.initials: M
authors.lastname: Reverchon
authors.affiliation: Service de Médecine et Biologie de la Reproduction, CHRU, Tours, France.
authors.forename: Marion
authors.initials: M
authors.lastname: Cornuau
authors.affiliation: UMR 7247 INRA-CNRS-Université de Tours-Haras Nationaux, Nouzilly, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Froment
authors.affiliation: UMR 7247 INRA-CNRS-Université de Tours-Haras Nationaux, Nouzilly, France.
authors.forename: Christelle
authors.initials: C
authors.lastname: Ramé
authors.affiliation: Université de Lyon, (UCB-lyon1), Lyon, France INSERM, Lyon, France Ecole Normale Supérieure de Lyon, Lyon, France.
authors.forename: Caroline
authors.initials: C
authors.lastname: Costa
authors.affiliation: Université de Lyon, (UCB-lyon1), Lyon, France INSERM, Lyon, France Ecole Normale Supérieure de Lyon, Lyon, France.
authors.forename: Gisèle
authors.initials: G
authors.lastname: Froment
authors.affiliation: Unité d'Endocrinologie Nutrition Diabète, CHRU de Tours, Tours, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Lecomte
authors.affiliation: Beckman Research Institute of the City of Hope, Duarte, California.
authors.forename: Wenyong
authors.initials: W
authors.lastname: Chen
authors.affiliation: UMR 7247 INRA-CNRS-Université de Tours-Haras Nationaux, Nouzilly, France Service de Médecine et Biologie de la Reproduction, CHRU, Tours, France.
authors.forename: Dominique
authors.initials: D
authors.lastname: Royère
authors.affiliation: UMR 7247 INRA-CNRS-Université de Tours-Haras Nationaux, Nouzilly, France Service de Médecine et Biologie de la Reproduction, CHRU, Tours, France.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Guerif
authors.affiliation: UMR 7247 INRA-CNRS-Université de Tours-Haras Nationaux, Nouzilly, France jdupont@tours.fr.
authors.forename: Joëlle
authors.initials: J
authors.lastname: Dupont
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism; D000328:Adult; D001141:Aromatase / Q000235:genetics / Q000378:metabolism; D016207:Cytokines / Q000235:genetics / Q000378:metabolism*; D004958:Estradiol / Q000096:biosynthesis; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D058851:GPI-Linked Proteins / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects*; D055785:Gene Knockdown Techniques; D006801:Humans; D007004:Hypoglycemic Agents / Q000494:pharmacology; D055504:Insulin Receptor Substrate Proteins / Q000235:genetics / Q000378:metabolism; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D037102:Lectins / Q000235:genetics / Q000378:metabolism*; D008184:Luteal Cells / Q000378:metabolism*; D007986:Luteinizing Hormone / Q000494:pharmacology; D008687:Metformin / Q000494:pharmacology; D020929:Mitogen-Activated Protein Kinase Kinases / Q000235:genetics / Q000378:metabolism; D054409:Nicotinamide Phosphoribosyltransferase / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017526:Receptor, IGF Type 1 / Q000235:genetics / Q000378:metabolism; D013256:Steroids / Q000096:biosynthesis*
chemical_list: D016207:Cytokines; D058851:GPI-Linked Proteins; D007004:Hypoglycemic Agents; C526292:IRS1 protein, human; C432397:ITLN1 protein, human; D055504:Insulin Receptor Substrate Proteins; D037102:Lectins; D012333:RNA, Messenger; D013256:Steroids; D004958:Estradiol; D007334:Insulin-Like Growth Factor I; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D008687:Metformin; D001141:Aromatase; C561410:CYP19A1 protein, human; D054409:Nicotinamide Phosphoribosyltransferase; C085455:nicotinamide phosphoribosyltransferase, human; D017526:Receptor, IGF Type 1; D055372:AMP-Activated Protein Kinases; D020929:Mitogen-Activated Protein Kinase Kinases
keywords: IGF-1; NAMPT; PCOS; adipokine; fertility; ovary; signaling pathways