title: The human glucagon-like peptide-1 analogue liraglutide preserves pancreatic beta cells via regulation of cell kinetics and suppression of oxidative and endoplasmic reticulum stress in a mouse model of diabetes.
abstract: OBJECTIVE
  We investigated the molecular mechanism by which the human glucagon-like peptide-1 analogue liraglutide preserves pancreatic beta cells in diabetic db/db mice.
  
  
  METHODS
  Male db/db and m/m mice aged 10 weeks received liraglutide or vehicle for 2 days or 2 weeks. In addition to morphological and biochemical analysis of pancreatic islets, gene expression profiles in the islet core area were investigated by laser capture microdissection and real-time RT-PCR.
  
  
  RESULTS
  Liraglutide treatment for 2 weeks improved metabolic variables and insulin sensitivity in db/db mice. Liraglutide also increased glucose-stimulated insulin secretion (GSIS) and islet insulin content in both mouse strains and reduced triacylglycerol content in db/db mice. Expression of genes involved in cell differentiation and proliferation in both mouse strains was regulated by liraglutide, which, in db/db mice, downregulated genes involved in pro-apoptosis, endoplasmic reticulum (ER) stress and lipid synthesis, and upregulated genes related to anti-apoptosis and anti-oxidative stress. In the 2 day experiment, liraglutide slightly improved metabolic variables in db/db mice, but GSIS, insulin and triacylglycerol content were not affected. In db/db mice, liraglutide increased gene expression associated with cell differentiation, proliferation and anti-apoptosis, and suppressed gene expression involved in pro-apoptosis; it had no effect on genes related to oxidative stress or ER stress. Morphometric results for cell proliferation, cell apoptosis and oxidative stress in db/db mice islets were consistent with the results of the gene expression analysis.
  
  
  CONCLUSIONS
  Liraglutide increases beta cell mass not only by directly regulating cell kinetics, but also by suppressing oxidative and ER stress, secondary to amelioration of glucolipotoxicity.
authors.affiliation: Division of Diabetes, Endocrinology and Metabolism, Department of Internal Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama 701-0192, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Shimoda
authors.forename: Y
authors.initials: Y
authors.lastname: Kanda
authors.forename: S
authors.initials: S
authors.lastname: Hamamoto
authors.forename: K
authors.initials: K
authors.lastname: Tawaramoto
authors.forename: M
authors.initials: M
authors.lastname: Hashiramoto
authors.forename: M
authors.initials: M
authors.lastname: Matsuki
authors.forename: K
authors.initials: K
authors.lastname: Kaku
mesh_terms: D000818:Animals; D003920:Diabetes Mellitus / Q000188:drug therapy* / Q000378:metabolism; D004435:Eating / Q000187:drug effects; D004721:Endoplasmic Reticulum / Q000187:drug effects*; D052216:Glucagon-Like Peptide 1 / Q000031:analogs & derivatives* / Q000627:therapeutic use; D006801:Humans; D007150:Immunohistochemistry; D050417:Insulin-Secreting Cells / Q000187:drug effects*; D007515:Islets of Langerhans / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D000069450:Liraglutide; D008297:Male; D051379:Mice; D042282:Microdissection; D018384:Oxidative Stress / Q000187:drug effects*; D016133:Polymerase Chain Reaction; D015430:Weight Gain / Q000187:drug effects
chemical_list: D000069450:Liraglutide; D052216:Glucagon-Like Peptide 1