title: Enhanced transcription of pancreatic peptide YY by 1α-hydroxyvitamin D3 administration in streptozotocin-induced diabetic mice.
abstract: Peptide YY (PYY) is a peptide hormone secreted from L cells in the intestine in response to food intake that regulates appetite and gastrointestinal function. PYY is also produced in the pancreatic islets. The vitamin D receptor (VDR) is a nuclear receptor for the active form of vitamin D3 that regulates numerous physiological processes. VDR is expressed in the pancreatic islets and pharmacological VDR activation increases PYY expression in mouse peripheral islet cells. Although VDR is present in insulin-producing β cells as well as non-β cells, the role of β cell VDR in Pyy transcription remains unknown. We treated mice with streptozotocin to ablate β cells in the pancreas. Pancreatic Vdr mRNA expression was decreased in streptozotocin-induced diabetic mice. Interestingly, streptozotocin-treated mice exhibited increased basal Pyy expression and 1α-hydroxyvitamin D3 treatment further increased expression. Moreover, 1α-hydroxyvitamin D3 increased mRNA expression of pancreatic polypeptide and decreased that of neuropeptide Y in streptozotocin-induced diabetic mice but not in control mice. 1α-Hydroxyvitamin D3 slightly increased mRNA expression of insulin but transcript levels were nearly undetectable in the pancreas of streptozotocin-treated mice. Thus, VDR in non-β islet cells is involved in Pyy expression in the mouse pancreas. The findings from this β cell ablation study suggest a hormone transcription regulatory network composed of β cells and non-β cells.
authors.affiliation: Division of Biochemistry, Department of Biomedical Sciences, Nihon University School of Medicine, 30-1 Oyaguchi-kamicho, Itabashi-ku, Tokyo 173-8610, Japan; Division of Breast and Endocrine Surgery, Department of Surgery, Nihon University School of Medicine, 30-1 Oyaguchi-kamicho, Itabashi-ku, Tokyo 173-8610, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Ozeki
authors.forename: Mihwa
authors.initials: M
authors.lastname: Choi
authors.forename: Kaori
authors.initials: K
authors.lastname: Endo-Umeda
authors.forename: Kenichi
authors.initials: K
authors.lastname: Sakurai
authors.forename: Sadao
authors.initials: S
authors.lastname: Amano
authors.forename: Makoto
authors.initials: M
authors.lastname: Makishima
mesh_terms: D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000235:genetics* / Q000378:metabolism; D006887:Hydroxycholecalciferols / Q000008:administration & dosage / Q000494:pharmacology*; D050417:Insulin-Secreting Cells / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010179:Pancreas / Q000187:drug effects / Q000378:metabolism; D019894:Peptide YY / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D018167:Receptors, Calcitriol / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D006887:Hydroxycholecalciferols; D012333:RNA, Messenger; D018167:Receptors, Calcitriol; D019894:Peptide YY; C008088:alfacalcidol
keywords: Islet β cells; Neuropeptide Y; Pancreatic polypeptide; Peptide YY; Streptozotocin; Vitamin D receptor