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Nils Wierup

Nils Wierup

Senior lecturer

Nils Wierup

Apelin is a novel islet peptide.

Author

  • Camilla Ringström
  • Marloes Dekker Nitert
  • Hedvig Bennet
  • Malin Fex
  • Philippe Valet
  • Jens F Rehfeld
  • Lennart Friis-Hansen
  • Nils Wierup

Summary, in English

Apelin, a recently discovered peptide with wide tissue distribution, regulates feeding behavior, improves glucose utilization, and inhibits insulin secretion. We examined whether apelin is expressed in human islets, as well as in normal and type 2 diabetic (T2D) animal islets. Further, we studied islet apelin regulation and the effect of apelin on insulin secretion. Apelin expression and regulation was examined in human and animal specimens using immunocytochemistry, in situ hybridization, and real-time PCR. Insulin secretion was studied in INS-1 (832/13) clonal beta cells. APJ-receptor expression was studied using real-time PCR. In human and murine islets apelin was predominantly expressed in beta cells and alpha cells; a subpopulation of the PP cells in human islets also harbored apelin. In porcine and feline islets apelin was mainly expressed in beta cells. APJ-receptor expression was detected in INS-1 (832/13) cells, and in human and mouse islets. A high dose (1microM) of apelin-36 caused a moderate increase in glucose-stimulated insulin secretion (30%; p<0.001), while lower concentrations (10-100nM) of apelin robustly reduced insulin secretion by 50% (p<0.001). Apelin was upregulated in beta cells of T2D db/db mice (47% vs. controls; p<0.02) and GK-rats (74% vs. controls; p<0.002), but human islet apelin expression was unaffected by glucose. On the other hand, human islet apelin expression was diminished after culture in glucocorticoids (16% vs. controls; p<0.01). We conclude that apelin is a novel insulin-regulating islet peptide in humans and several laboratory animals. Islet apelin expression is negatively regulated by glucocorticoids, and upregulated in T2D animals. The presence of apelin receptors in islets suggests a role for apelin as a paracrine or autocrine messenger within the islets.

Department/s

  • Genomics, Diabetes and Endocrinology
  • Celiac Disease and Diabetes Unit
  • Department of Experimental Medical Science
  • EXODIAB: Excellence of Diabetes Research in Sweden

Publishing year

2010

Language

English

Pages

44-51

Publication/Series

Regulatory Peptides

Volume

162

Document type

Journal article

Publisher

Elsevier

Topic

  • Cell and Molecular Biology

Status

Published

Research group

  • Genomics, Diabetes and Endocrinology
  • Diabetes and Celiac Unit

ISBN/ISSN/Other

  • ISSN: 1873-1686