title: Cholecystokinin expression in the β-cell leads to increased β-cell area in aged mice and protects from streptozotocin-induced diabetes and apoptosis.
abstract: Cholecystokinin (CCK) is a peptide hormone produced in the gut and brain with beneficial effects on digestion, satiety, and insulin secretion. CCK is also expressed in pancreatic β-cells, but only in models of obesity and insulin resistance. Whole body deletion of CCK in obese mice leads to reduced β-cell mass expansion and increased apoptosis. We hypothesized that islet-derived CCK is important in protection from β-cell apoptosis. To determine the specific role of β-cell-derived CCK in β-cell mass dynamics, we generated a transgenic mouse that expresses CCK in the β-cell in the lean state (MIP-CCK). Although this transgene contains the human growth hormone minigene, we saw no expression of human growth hormone protein in transgenic islets. We examined the ability of MIP-CCK mice to maintain β-cell mass when subjected to apoptotic stress, with advanced age, and after streptozotocin treatment. Aged MIP-CCK mice have increased β-cell area. MIP-CCK mice are resistant to streptozotocin-induced diabetes and exhibit reduced β-cell apoptosis. Directed CCK overexpression in cultured β-cells also protects from cytokine-induced apoptosis. We have identified an important new paracrine/autocrine effect of CCK in protection of β-cells from apoptotic stress. Understanding the role of β-cell CCK adds to the emerging knowledge of classic gut peptides in intraislet signaling. CCK receptor agonists are being investigated as therapeutics for obesity and diabetes. While these agonists clearly have beneficial effects on body weight and insulin sensitivity in peripheral tissues, they may also directly protect β-cells from apoptosis.
authors.affiliation: School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin;
authors.forename: Jeremy A
authors.initials: JA
authors.lastname: Lavine
authors.affiliation: Department of Medicine, Division of Endocrinology, University of Wisconsin-Madison, Madison, Wisconsin;
authors.forename: Carly R
authors.initials: CR
authors.lastname: Kibbe
authors.affiliation: Department of Medicine, Division of Endocrinology, University of Wisconsin-Madison, Madison, Wisconsin;
authors.forename: Mieke
authors.initials: M
authors.lastname: Baan
authors.affiliation: Department of Medicine, Division of Endocrinology, University of Wisconsin-Madison, Madison, Wisconsin;
authors.forename: Sirinart
authors.initials: S
authors.lastname: Sirinvaravong
authors.affiliation: Department of Medicine, Division of Endocrinology, University of Wisconsin-Madison, Madison, Wisconsin;
authors.forename: Heidi M
authors.initials: HM
authors.lastname: Umhoefer
authors.affiliation: Department of Medicine, Division of Endocrinology, University of Wisconsin-Madison, Madison, Wisconsin;
authors.forename: Kimberly A
authors.initials: KA
authors.lastname: Engler
authors.affiliation: Department of Medicine, Division of Endocrinology, University of Wisconsin-Madison, Madison, Wisconsin;
authors.forename: Louise M
authors.initials: LM
authors.lastname: Meske
authors.affiliation: Department of Medicine, Division of Endocrinology, University of Wisconsin-Madison, Madison, Wisconsin;
authors.forename: Kaitlyn A
authors.initials: KA
authors.lastname: Sacotte
authors.affiliation: Department of Medicine, Division of Endocrinology, University of Wisconsin-Madison, Madison, Wisconsin;
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Erhardt
authors.affiliation: Department of Medicine, Division of Endocrinology, University of Wisconsin-Madison, Madison, Wisconsin; Geriatric Research Education and Clinical Centers, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin dbd@medicine.wisc.edu.
authors.forename: Dawn Belt
authors.identifier: http://orcid.org/0000-0002-0239-4715
authors.initials: DB
authors.lastname: Davis
mesh_terms: D000375:Aging; D000818:Animals; D017209:Apoptosis; D002460:Cell Line; D002766:Cholecystokinin / Q000235:genetics / Q000378:metabolism*; D016207:Cytokines / Q000009:adverse effects / Q000235:genetics / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000378:metabolism* / Q000473:pathology / Q000517:prevention & control; D015536:Down-Regulation; D006943:Hyperglycemia / Q000097:blood / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control; D007328:Insulin / Q000235:genetics / Q000378:metabolism; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000166:cytology / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008822:Mice, Transgenic; D011401:Promoter Regions, Genetic; D051381:Rats; D011994:Recombinant Proteins / Q000009:adverse effects / Q000378:metabolism; D013311:Streptozocin; D013312:Stress, Physiological; D046509:Tissue Culture Techniques
chemical_list: D016207:Cytokines; C514817:Ins1 protein, mouse; D007328:Insulin; D011994:Recombinant Proteins; D013311:Streptozocin; D002766:Cholecystokinin
keywords: aging; apoptosis; cholecystokinin; islet; streptozotocin; β-cell