en
Scientific article
English

Increasing GLP-1-induced beta-cell proliferation by silencing the negative regulators of signaling cAMP response element modulator-alpha and DUSP14

Published inDiabetes, vol. 57, no. 3, p. 584-593
Publication date2008
Abstract

OBJECTIVE: Glucagon-like peptide-1 (GLP-1) is a growth and differentiation factor for mature beta-cells and their precursors. However, the overall effect of GLP-1 on increasing beta-cell mass in both in vivo and in vitro conditions is relatively small, and augmenting this effect would be beneficial for the treatment or prevention of type 1 and type 2 diabetes. Here, we searched for cellular mechanisms that may limit the proliferative effect of GLP-1 and tested whether blocking them could increase beta-cell proliferation. RESEARCH DESIGN AND METHODS: We examined GLP-1-regulated genes in beta TC-Tet cells by cDNA microarrays. To assess the effect of some of these gene on cell proliferation, we reduced their expression using small heterogenous RNA in beta-cell lines and primary mouse islets and measured [(3)H]thymidine or 5'-bromo-2'-deoxyuridine incorporation. RESULTS: We identified four negative regulators of intracellular signaling that were rapidly and strongly activated by GLP-1: the regulator of G-protein-signaling RGS2; the cAMP response element-binding protein (CREB) antagonists cAMP response element modulator (CREM)-alpha and ICERI; and the dual specificity phosphatase DUSP14, a negative regulator of the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase 1/2 (ERK1/2) pathway. We show that knockdown of CREMalpha or DUSP14 or expression of a dominant-negative form of DUSP14 increased beta-cell line proliferation and enhanced the GLP-1-induced proliferation of primary beta-cells. CONCLUSIONS: Together, our data show that 1) the cAMP/protein kinase A/CREB and MAPK/ERK1/2 pathways can additively control beta-cell proliferation, 2) beta-cells have evolved several mechanisms limiting GLP-1-induced cellular proliferation, and 3) blocking these mechanisms increases the positive effect of GLP-1 on beta-cell mass.

Keywords
  • Animals
  • Cell Line
  • Cell Proliferation/drug effects
  • Cells, Cultured
  • Cyclic AMP Response Element Modulator/genetics/metabolism
  • Dose-Response Relationship, Drug
  • Dual-Specificity Phosphatases/genetics/metabolism
  • Gene Expression Profiling
  • Gene Silencing
  • Glucagon-Like Peptide 1/pharmacology
  • Glucose/metabolism/pharmacology
  • Humans
  • Insulin-Secreting Cells/cytology/drug effects
  • Male
  • Mice
  • Oligonucleotide Array Sequence Analysis
  • Peptides/pharmacology
  • RGS Proteins/genetics/metabolism
  • Venoms/pharmacology
Citation (ISO format)
KLINGER, Sonia et al. Increasing GLP-1-induced beta-cell proliferation by silencing the negative regulators of signaling cAMP response element modulator-alpha and DUSP14. In: Diabetes, 2008, vol. 57, n° 3, p. 584–593. doi: 10.2337/db07-1414
Main files (1)
Article (Accepted version)
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Secondary files (1)
Identifiers
ISSN of the journal1939-327X
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