Liraglutide regulates the viability of pancreatic α-cells and pancreatic β-cells through cAMP-PKA signal pathway

Life Sci. 2018 Feb 15:195:87-94. doi: 10.1016/j.lfs.2017.12.012. Epub 2017 Dec 7.

Abstract

Aims: As a glucagon-like peptide-1 receptor agonist, liraglutide could effectively increase insulin secretion from pancreatic β-cells and suppress glucagon secretion from pancreatic α-cells in the treatment of hyperglycemia in type 2 diabetes patients. However, the mechanisms for the different regulation of pancreatic α-cells and β-cells are still unclear. In this study, we mainly explored the different effects of liraglutide on mouse pancreatic α-cell line and β-cell line in vitro.

Main methods: Herein, mouse pancreatic α-cell line, α-TC1-6, and mouse pancreatic β-cell line, β-TC-tet, were used to analyze the biological effects of liraglutide in different concentrations. Cell proliferation, cell apoptosis and cell secretion ability were detected in different groups. Besides, the level of miR-375 and cAMP-PKA signal pathway were further evaluated using qPCR and western blot.

Key findings: The results indicated that liraglutide could increase the level of miR-375 and cell apoptosis in pancreatic α-cells through inhibiting the cAMP-PKA signal pathway, but activate cAMP-PKA signal pathway in pancreatic β-cells, and further lead to the down-regulation of miR-375 and improve cell viability. Therefore, the treatment with liraglutide could down-regulate the glucagon secretion ability of α-TC1-6 cells, and the insulin secretion ability of β-TC-tet cells was enhanced with the liraglutide treatment in a dose-dependent manner.

Significance: In conclusion, we mainly found that liraglutide could regulate the viability of pancreatic α-cells and pancreatic β-cells through inhibiting and activating cAMP-PKA signal pathway respectively. The better understanding of the mechanism could help us to develop more novel therapy methods for diabetes in the future.

Keywords: Cell apoptosis; Cell secretion; Cell viability; Liraglutide; cAMP-PKA signal pathway; miR-375.

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Cell Line
  • Cell Survival / drug effects
  • Cyclic AMP / physiology*
  • Cyclic AMP-Dependent Protein Kinases / physiology*
  • Glucagon / metabolism
  • Glucagon-Secreting Cells / drug effects*
  • Glucagon-Secreting Cells / metabolism
  • Hypoglycemic Agents / pharmacology*
  • Insulin / metabolism
  • Insulin Secretion
  • Insulin-Secreting Cells / drug effects*
  • Insulin-Secreting Cells / metabolism
  • Liraglutide / pharmacology*
  • Mice
  • MicroRNAs / biosynthesis
  • Signal Transduction / drug effects*

Substances

  • Hypoglycemic Agents
  • Insulin
  • MicroRNAs
  • Mirn375 microRNA, mouse
  • Liraglutide
  • Glucagon
  • Cyclic AMP
  • Cyclic AMP-Dependent Protein Kinases