Effect of GLP-1 (glucagon-like peptide 1:7-36 amide) on porcine pancreatic endocrine cell proliferation and insulin secretion

Pancreas. 2004 Mar;28(2):138-45. doi: 10.1097/00006676-200403000-00004.

Abstract

Introduction: We have established a method of isolation and primary monolayer culture of porcine pancreatic endocrine (PE) cells using nicotinamide. Recently, several insulin-stimulating factors have been recognized as modifying the function of endocrine cells. Glucagon-like peptide 1 (GLP-1), derived from intestinal cells, is one of the substances that may regulate insulin secretion and cell proliferation.

Aim: The aim of the current study was to examine the effect of GLP-1 on PE cell proliferation and insulin secretion in our culture system.

Methodology: The PE cells were prepared by nonenzymatic digestion and cultured in media with or without 10 nmol/L GLP-1 and maintained for 15 days. Basal insulin secretion and the glucose stimulated-response were observed by enzyme assay. PE-cell proliferation was assessed using 5-bromo 2' deoxyuridine (BrdU). beta-Cell specificity was confirmed by double staining with anti-BrdU and insulin antibody. mRNA expression in PE cells for insulin and pancreatic and duodenal homeobox gene 1 (PDX-1), a transcription factor, was semiquantitated by a real-time PCR method.

Results: Neither baseline nor glucose-stimulated insulin secretion differed significantly with or without the addition of 10 nmol/L GLP-1. However, significant changes of insulin secretion were observed in doses up to 100 nmol/L of GLP-1. BrdU incorporation increased with 10 nmol/L GLP-1 from 2.35+/- 0.16% to 9.11+/- 0.53% as compared with the control (from 2.17 +/- 0.57% to 6.13 +/- 0.35%). This increase was observed after a 12-day culture period. Double staining identified well-preserved insulin-containing cells, but neither the number of positive cells nor staining intensity differed significantly between the 2 groups during the 15-day culture period. The level of mRNA expression for both insulin and PDX-1 increased slightly but significantly.

Conclusions: GLP-1 has a proliferative effect on PE cells and affects gene expression in short-term culture.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Proliferation / drug effects
  • Cells, Cultured
  • Glucagon
  • Glucagon-Like Peptide 1
  • Glucagon-Like Peptides
  • Glucose / pharmacology
  • Insulin / genetics
  • Insulin / metabolism*
  • Insulin Secretion
  • Islets of Langerhans / cytology
  • Islets of Langerhans / drug effects*
  • Islets of Langerhans / metabolism
  • Peptide Fragments / pharmacology*
  • Potassium / pharmacology
  • RNA, Messenger / metabolism
  • Swine

Substances

  • Insulin
  • Peptide Fragments
  • RNA, Messenger
  • glucagon-like peptide 1 (7-36)amide
  • Glucagon-Like Peptides
  • Glucagon-Like Peptide 1
  • Glucagon
  • Glucose
  • Potassium