Incretin Action in the Pancreas: Potential Promise, Possible Perils, and Pathological Pitfalls

• Published in: Diabetes (New York, N.Y.) Vol. 62; no. 10; pp. 3316 - 3323
• Main Author: Drucker, Daniel J.
• Format: Journal Article
• Language: English
• Published: Alexandria, VA American Diabetes Association 01.10.2013
• Subjects: Acinar Cells - metabolism; Animals; Atherosclerosis - drug therapy; Atherosclerosis - metabolism; Atherosclerosis - physiopathology; Biological and medical sciences; Blotting, Western; Cell Proliferation; Cricetinae; Diabetes; Diabetes Mellitus - drug therapy; Diabetes Mellitus - metabolism; Diabetes Mellitus - physiopathology; Diabetes therapy; Diabetes. Impaired glucose tolerance; Dipeptidyl-Peptidase IV Inhibitors - therapeutic use; Endocrine pancreas. Apud cells (diseases); Endocrinopathies; Enzymes; Etiopathogenesis. Screening. Investigations. Target tissue resistance; Female; G proteins; Gastric Inhibitory Polypeptide - metabolism; Glucagon-Like Peptide 1 - metabolism; Glucagon-Like Peptide-1 Receptor; Glucose metabolism; Health aspects; Humans; Incretins - metabolism; Inflammation - metabolism; Insulin-Secreting Cells - metabolism; Male; Medical sciences; Mice; Pancreas; Pancreas - drug effects; Pancreas - metabolism; Pancreas - physiopathology; Pathology; Peptides; Rats; Real-Time Polymerase Chain Reaction; Receptors, Gastrointestinal Hormone - metabolism; Receptors, Glucagon - agonists; Rodents; s in Diabetes; Endocrinopathy; Incretin; Pancreas; Diabetes mellitus
• ISSN: 0012-1797; 1939-327X; 1939-327X
• DOI: 10.2337/db13-0822

Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are incretin hormones that control the secretion of insulin, glucagon, and somatostatin to facilitate glucose disposal. The actions of incretin hormones are terminated via enzymatic cleavage by dipeptidyl peptidase-4 (DPP-4) and through renal clearance. GLP-1 and GIP promote β-cell proliferation and survival in rodents. DPP-4 inhibitors expand β-cell mass, reduce α-cell mass, and inhibit glucagon secretion in preclinical studies; however, whether incretin-based therapies sustain functional β-cell mass in human diabetic subjects remains unclear. GLP-1 and GIP exert their actions predominantly through unique G protein-coupled receptors expressed on β-cells and other pancreatic cell types. Accurate localization of incretin receptor expression in pancreatic ductal or acinar cells in normal or diabetic human pancreas is challenging because antisera used for detection of the GLP-1 receptor often are neither sufficiently sensitive nor specific to yield reliable data. This article reviews recent advances and controversies in incretin hormone action in the pancreas and contrasts established mechanisms with areas of uncertainty. Furthermore, methodological challenges and pitfalls are highlighted and key areas requiring additional scientific investigation are outlined.