title: Type I neuregulin1α is a novel local mediator to suppress hepatic gluconeogenesis in mice.
abstract: Neuregulin1 is an epidermal growth factor (EGF)-like domain-containing protein that has multiple isoforms and functions as a local mediator in the control of various cellular functions. Here we show that type I isoform of neuregulin1 with an α-type EGF-like domain (Nrg1α) is the major isoform in mouse liver and regulates hepatic glucose production. Forced expression of Nrg1α in mouse liver enhanced systemic glucose disposal and decreased hepatic glucose production with reduced fasting blood glucose levels. Nuclear forkhead box protein O1 (FoxO1) and its downstream targets, PEPCK and G6Pase, were suppressed in liver and isolated hepatocytes by Nrg1α overexpression. In contrast, silencing of Nrg1α enhanced glucose production with increased PEPCK and G6Pase expressions in cAMP/dexamethasone-stimulated hepatocytes. Mechanistically, the recombinant α-type EGF-like domain of NRG1α (rNRG1α) stimulated the ERBB3 signalling pathway in hepatocytes, resulting in decreased nuclear FoxO1 accumulation via activation of both the AKT and ERK pathways. In addition, acute treatment with rNRG1α also suppressed elevation of blood glucose levels after both glucose and pyruvate challenge. Although a liver-specific deletion of Nrg1 gene in mice showed little effect on systemic glucose metabolism, these results suggest that NRG1α have a novel regulatory function in hepatic gluconeogenesis by regulating the ERBB3-AKT/ERK-FoxO1 cascade.
authors.affiliation: Department of Life Science and Medical Bioscience, School of Advanced Science and Engineering, Waseda University, Tokyo, 162-8480, Japan.
authors.forename: Takatomo
authors.initials: T
authors.lastname: Arai
authors.affiliation: Department of Life Science and Medical Bioscience, School of Advanced Science and Engineering, Waseda University, Tokyo, 162-8480, Japan.
authors.forename: Yumika
authors.initials: Y
authors.lastname: Ono
authors.affiliation: Department of Life Science and Medical Bioscience, School of Advanced Science and Engineering, Waseda University, Tokyo, 162-8480, Japan.
authors.forename: Yujiro
authors.initials: Y
authors.lastname: Arimura
authors.affiliation: Department of Life Science and Medical Bioscience, School of Advanced Science and Engineering, Waseda University, Tokyo, 162-8480, Japan.
authors.forename: Keimon
authors.initials: K
authors.lastname: Sayama
authors.affiliation: Department of Life Science and Medical Bioscience, School of Advanced Science and Engineering, Waseda University, Tokyo, 162-8480, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Suzuki
authors.affiliation: Department of Life Science and Medical Bioscience, School of Advanced Science and Engineering, Waseda University, Tokyo, 162-8480, Japan.
authors.forename: Satoko
authors.initials: S
authors.lastname: Shinjo
authors.affiliation: Department of Life Science and Medical Bioscience, School of Advanced Science and Engineering, Waseda University, Tokyo, 162-8480, Japan.
authors.forename: Mai
authors.initials: M
authors.lastname: Kanai
authors.affiliation: Center for General Education, Kumamoto Health Science University, Kumamoto, 861-5598, Japan.
authors.forename: Shin-Ichi
authors.initials: SI
authors.lastname: Abe
authors.affiliation: Department of Life Science and Medical Bioscience, School of Advanced Science and Engineering, Waseda University, Tokyo, 162-8480, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Semba
authors.affiliation: Department of Life Science and Medical Bioscience, School of Advanced Science and Engineering, Waseda University, Tokyo, 162-8480, Japan.
authors.forename: Nobuhito
authors.initials: N
authors.lastname: Goda
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D003907:Dexamethasone / Q000494:pharmacology; D000071161:Forkhead Box Protein O1 / Q000378:metabolism; D005943:Gluconeogenesis / Q000187:drug effects; D005947:Glucose / Q000378:metabolism; D005952:Glucose-6-Phosphatase / Q000235:genetics / Q000378:metabolism; D022781:Hepatocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D020890:Neuregulin-1 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D010729:Phosphoenolpyruvate Carboxykinase (GTP) / Q000235:genetics / Q000378:metabolism; D020033:Protein Isoforms / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism; D020893:Receptor, ErbB-3 / Q000378:metabolism; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D000071161:Forkhead Box Protein O1; C467200:Foxo1 protein, mouse; D020890:Neuregulin-1; D020033:Protein Isoforms; D034741:RNA, Small Interfering; D011994:Recombinant Proteins; D003907:Dexamethasone; C000607800:ErbB3 protein, mouse; D020893:Receptor, ErbB-3; D005952:Glucose-6-Phosphatase; D010729:Phosphoenolpyruvate Carboxykinase (GTP); D005947:Glucose