Function of a long-term, GLP-1-treated, insulin-secreting cell line is improved by preventing DPP IV-mediated degradation of GLP-1

BD Green, HK Liu, Janie McCluskey, NA Duffy, Finbarr O'Harte, Neville McClenaghan, Peter Flatt

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

Glucagon-like peptide-1 (GLP-1) is an important insulinotropic hormone with potential in the treatment of type 2 diabetes. However, the short biological half-life of the peptide after cleavage by dipeptidylpeptidase IV (DPP IV) is a major limitation. Inhibition of DPP IV activity and the development of resistant GLP-1 analogues is the subject of ongoing research. In this study, we determined cell growth, insulin content, insulin accumulation and insulin secretory function of a insulin-secreting cell line cultured for 3 days with either GLP-1, GLP-1 plus the DPP IV inhibitor diprotin A (DPA) or stable N-acetyl-GLP-1. Native GLP-1 was rapidly degraded by DPP IV during culture with accumulation of the inactive metabolite GLP-1(9-36)amide. Inclusion of DPA or use of the DPP IV-resistant analogue, N-acetyl-GLP-1, improved cellular function compared to exposure to GLP-1 alone. Most notably, basal and accumulated insulin secretion was enhanced, and glucose responsiveness was improved. However, prolonged GLP-1 treatment resulted in GLP-1 receptor desensitization regardless of DPP IV status. The results indicate that prevention of DPP IV action is necessary for beneficial effects of GLP-1 on pancreatic beta cells and that prolonged exposure to GLP-1(9-36)amide may be detrimental to insulin secretory function. These observations also support the ongoing development of DPP-IV-resistant forms of GLP-1, such as N-acetyl-GLP-1.
Original languageEnglish
Pages (from-to)563-569
JournalDiabetes Obesity and Metabolism
Volume7
Issue number5
DOIs
Publication statusPublished - Sep 2005

Fingerprint Dive into the research topics of 'Function of a long-term, GLP-1-treated, insulin-secreting cell line is improved by preventing DPP IV-mediated degradation of GLP-1'. Together they form a unique fingerprint.

  • Cite this