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Yanagida B, Yamamoto T, Suzuki H. Amylin-like immunoreactivity in the extra-islet peptide YY-producing and glucagon-immunoreactive cells in Japanese quail pancreas. Anat Histol Embryol 2024; 53:e13074. [PMID: 38864153 DOI: 10.1111/ahe.13074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 05/21/2024] [Accepted: 05/31/2024] [Indexed: 06/13/2024]
Abstract
In this study, we investigated amylin-like substance distribution in the pancreas of Japanese quail (Coturnix japonica) using a specific anti-rat amylin serum. We detected amylin-immunoreactive cells dispersed in the pancreatic extra-islet region but not in the islet region. The synthetic rat amylin-containing serum pre-absorption abolished the staining profile. Almost all amylin-immunoreactive cells were immuno-positive for peptide YY (PYY). In addition, certain amylin-immunoreactive cells stained immuno-positive for glucagon. Amylin and PYY co-secreted from the extra-islet cells might participate in the insulin and glucagon release regulation in the pancreas and food intake modulation through the central nervous system.
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Affiliation(s)
- Bonten Yanagida
- Department of Biology, University of Teacher Education Fukuoka, Munakata, Fukuoka, Japan
| | - Toshiharu Yamamoto
- Department of Physical Therapy, Faculty of Medical Science, Nagoya Women's University, Nagoya, Aichi, Japan
- Brain Functions and Neuroscience Unit, Department of Oral Science, Graduate School of Dentistry, Kanagawa Dental University, Yokosuka, Kanagawa, Japan
| | - Hirohumi Suzuki
- Department of Biology, University of Teacher Education Fukuoka, Munakata, Fukuoka, Japan
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2
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Khan D, Moffett RC, Flatt PR, Tarasov AI. Classical and non-classical islet peptides in the control of β-cell function. Peptides 2022; 150:170715. [PMID: 34958851 DOI: 10.1016/j.peptides.2021.170715] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 11/25/2021] [Accepted: 12/17/2021] [Indexed: 12/25/2022]
Abstract
The dual role of the pancreas as both an endocrine and exocrine gland is vital for food digestion and control of nutrient metabolism. The exocrine pancreas secretes enzymes into the small intestine aiding digestion of sugars and fats, whereas the endocrine pancreas secretes a cocktail of hormones into the blood, which is responsible for blood glucose control and regulation of carbohydrate, protein and fat metabolism. Classical islet hormones, insulin, glucagon, pancreatic polypeptide and somatostatin, interact in an autocrine and paracrine manner, to fine-tube the islet function and insulin secretion to the needs of the body. Recently pancreatic islets have been reported to express a number of non-classical peptide hormones involved in metabolic signalling, whose major production site was believed to reside outside pancreas, e.g. in the small intestine. We highlight the key non-classical islet peptides, and consider their involvement, together with established islet hormones, in regulation of stimulus-secretion coupling as well as proliferation, survival and transdifferentiation of β-cells. We furthermore focus on the paracrine interaction between classical and non-classical islet hormones in the maintenance of β-cell function. Understanding the functional relationships between these islet peptides might help to develop novel, more efficient treatments for diabetes and related metabolic disorders.
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Affiliation(s)
- Dawood Khan
- Biomedical Sciences Research Institute, School of Biomedical Sciences, Ulster University, Coleraine, Northern Ireland, UK.
| | - R Charlotte Moffett
- Biomedical Sciences Research Institute, School of Biomedical Sciences, Ulster University, Coleraine, Northern Ireland, UK
| | - Peter R Flatt
- Biomedical Sciences Research Institute, School of Biomedical Sciences, Ulster University, Coleraine, Northern Ireland, UK
| | - Andrei I Tarasov
- Biomedical Sciences Research Institute, School of Biomedical Sciences, Ulster University, Coleraine, Northern Ireland, UK
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3
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Andersen DB, Holst JJ. Peptides in the regulation of glucagon secretion. Peptides 2022; 148:170683. [PMID: 34748791 DOI: 10.1016/j.peptides.2021.170683] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 10/21/2021] [Accepted: 11/02/2021] [Indexed: 02/06/2023]
Abstract
Glucose homeostasis is maintained by the glucoregulatory hormones, glucagon, insulin and somatostatin, secreted from the islets of Langerhans. Glucagon is the body's most important anti-hypoglycemic hormone, mobilizing glucose from glycogen stores in the liver in response to fasting, thus maintaining plasma glucose levels within healthy limits. Glucagon secretion is regulated by both circulating nutrients, hormones and neuronal inputs. Hormones that may regulate glucagon secretion include locally produced insulin and somatostatin, but also urocortin-3, amylin and pancreatic polypeptide, and from outside the pancreas glucagon-like peptide-1 and 2, peptide tyrosine tyrosine and oxyntomodulin, glucose-dependent insulinotropic polypeptide, neurotensin and ghrelin, as well as the hypothalamic hormones arginine-vasopressin and oxytocin, and calcitonin from the thyroid. Each of these hormones have distinct effects, ranging from regulating blood glucose, to regulating appetite, stomach emptying rate and intestinal motility, which makes them interesting targets for treating metabolic diseases. Awareness regarding the potential effects of the hormones on glucagon secretion is important since secretory abnormalities could manifest as hyperglycemia or even lethal hypoglycemia. Here, we review the effects of each individual hormone on glucagon secretion, their interplay, and how treatments aimed at modulating the plasma levels of these hormones may also influence glucagon secretion and glycemic control.
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Affiliation(s)
- Daniel B Andersen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Panum Institute, Blegdamsvej 3B, 2200, Copenhagen N, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Jens J Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Panum Institute, Blegdamsvej 3B, 2200, Copenhagen N, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.
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4
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Yang CH, Onda DA, Oakhill JS, Scott JW, Galic S, Loh K. Regulation of Pancreatic β-Cell Function by the NPY System. Endocrinology 2021; 162:6213414. [PMID: 33824978 DOI: 10.1210/endocr/bqab070] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Indexed: 01/24/2023]
Abstract
The neuropeptide Y (NPY) system has been recognized as one of the most critical molecules in the regulation of energy homeostasis and glucose metabolism. Abnormal levels of NPY have been shown to contribute to the development of metabolic disorders including obesity, cardiovascular diseases, and diabetes. NPY centrally promotes feeding and reduces energy expenditure, while the other family members, peptide YY (PYY) and pancreatic polypeptide (PP), mediate satiety. New evidence has uncovered additional functions for these peptides that go beyond energy expenditure and appetite regulation, indicating a more extensive function in controlling other physiological functions. In this review, we will discuss the role of the NPY system in the regulation of pancreatic β-cell function and its therapeutic implications for diabetes.
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Affiliation(s)
- Chieh-Hsin Yang
- St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | - Danise-Ann Onda
- St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | - Jonathan S Oakhill
- St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
- Department of Medicine, University of Melbourne, Parkville, VIC 3010, Australia
- Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC 3000, Australia
| | - John W Scott
- St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
- Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC 3000, Australia
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC 3010, Australia
| | - Sandra Galic
- St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
- Department of Medicine, University of Melbourne, Parkville, VIC 3010, Australia
| | - Kim Loh
- St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
- Department of Medicine, University of Melbourne, Parkville, VIC 3010, Australia
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5
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Maroni MJ, Capri KM, Cushman AV, Deane HV, Concepcion H, DeCourcey H, Seggio JA. The timing of fasting leads to different levels of food consumption and PYY 3-36 in nocturnal mice. Hormones (Athens) 2020; 19:549-558. [PMID: 32572709 DOI: 10.1007/s42000-020-00221-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 06/09/2020] [Indexed: 12/21/2022]
Abstract
PURPOSE The daily circadian cycle is known to modulate both feeding behavior and metabolism. As such, the timing of food consumption can play a role in regulating overall health. The purpose of this study is to determine whether fasting at different times of the day alters subsequent food consumption and levels of PYY3-36, a hormone secreted after a meal which inhibits appetite. METHODS Separate groups of mice were fasted at different times of the day: (1) start of the day, (2) middle of the day, (3) start of the night, and (4) middle of the night, and either injected with vehicle or PYY3-36 to assess their subsequent food consumption patterns, PYY3-36 levels, and glucose and insulin levels. We also investigated whether light exposure during the night would alter food consumption and PYY3-36 levels after fasting. RESULTS Mice fasted during the start of the daytime exhibited increased food consumption post-fast compared to mice fasted during the night. Injections of PYY3-36 during the night were more effective in reducing food consumption compared to PYY3-36 administration during the day. Constant light exposure suppressed food consumption after fasting and increased fasting PYY3-36 levels. CONCLUSIONS These results indicate that mice exhibit distinct food consumption patterns after being presented with a fast at different times of the day. Light exposure also modulates both food consumption after a fast and levels of PYY3-36.
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Affiliation(s)
- Marissa J Maroni
- Department of Biological Sciences, Bridgewater State University, 24 Park Ave., Bridgewater State University, Bridgewater, MA, 02325, USA
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Kimberly M Capri
- Department of Biological Sciences, Bridgewater State University, 24 Park Ave., Bridgewater State University, Bridgewater, MA, 02325, USA
- Boston University, Boston, MA, 02215, USA
| | - Alexis V Cushman
- Department of Biological Sciences, Bridgewater State University, 24 Park Ave., Bridgewater State University, Bridgewater, MA, 02325, USA
| | - Hannah V Deane
- Department of Biological Sciences, Bridgewater State University, 24 Park Ave., Bridgewater State University, Bridgewater, MA, 02325, USA
| | - Holly Concepcion
- Department of Biological Sciences, Bridgewater State University, 24 Park Ave., Bridgewater State University, Bridgewater, MA, 02325, USA
| | - Holly DeCourcey
- Department of Biological Sciences, Bridgewater State University, 24 Park Ave., Bridgewater State University, Bridgewater, MA, 02325, USA
| | - Joseph A Seggio
- Department of Biological Sciences, Bridgewater State University, 24 Park Ave., Bridgewater State University, Bridgewater, MA, 02325, USA.
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6
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English A, Irwin N. Nonclassical Islet Peptides: Pancreatic and Extrapancreatic Actions. CLINICAL MEDICINE INSIGHTS-ENDOCRINOLOGY AND DIABETES 2019; 12:1179551419888871. [PMID: 32425629 PMCID: PMC7216561 DOI: 10.1177/1179551419888871] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 10/21/2019] [Indexed: 02/06/2023]
Abstract
The pancreas has physiologically important endocrine and exocrine functions; secreting enzymes into the small intestine to aid digestion and releasing multiple peptide hormones via the islets of Langerhans to regulate glucose metabolism, respectively. Insulin and glucagon, in combination with ghrelin, pancreatic polypeptide and somatostatin, are the main classical islet peptides critical for the maintenance of blood glucose. However, pancreatic islets also synthesis numerous ‘nonclassical’ peptides that have recently been demonstrated to exert fundamental effects on overall islet function and metabolism. As such, insights into the physiological relevance of these nonclassical peptides have shown impact on glucose metabolism, insulin action, cell survival, weight loss, and energy expenditure. This review will focus on the role of individual nonclassical islet peptides to stimulate pancreatic islet secretions as well as regulate metabolism. In addition, the more recognised actions of these peptides on satiety and energy regulation will also be considered. Furthermore, recent advances in the field of peptide therapeutics and obesity-diabetes have focused on the benefits of simultaneously targeting several hormone receptor signalling cascades. The potential for nonclassical islet hormones within such combinational approaches will also be discussed.
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Affiliation(s)
- Andrew English
- School of Pharmacy and Pharmaceutical Sciences, Ulster University, Coleraine, Northern Ireland, UK
| | - Nigel Irwin
- School of Pharmacy and Pharmaceutical Sciences, Ulster University, Coleraine, Northern Ireland, UK
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Kokkinos A, Tsilingiris D, le Roux CW, Rubino F, Mantzoros CS. Will medications that mimic gut hormones or target their receptors eventually replace bariatric surgery? Metabolism 2019; 100:153960. [PMID: 31412266 DOI: 10.1016/j.metabol.2019.153960] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 07/31/2019] [Accepted: 08/05/2019] [Indexed: 02/07/2023]
Abstract
Bariatric surgery is currently the most effective therapeutic modality through which sustained beneficial effects on weight loss and metabolic improvement are achieved. During recent years, indications for bariatric surgery have been expanded to include cases of poorly controlled type 2 (T2DM) diabetes mellitus in lesser extremes of body weight. A spectrum of the beneficial effects of surgery is attributed to robust changes of postprandial gut peptide responses that are observed post operatively. Consolidated knowledge regarding gut peptide physiology as well as emerging new evidence shedding light on the mode of action of previously overlooked gut hormones provide appealing potential obesity and T2DM therapeutic perspectives. The accumulation of evidence from the effect of exogenous administration of native gut peptides alone or in combinations to humans as well as the development of mimetic agents exerting agonistic effects on combinations of gut hormone receptors pave the way for future integrated gut peptide-based treatments, which may mimic the effects of bariatric surgery.
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Affiliation(s)
- Alexander Kokkinos
- First Department of Propaedeutic Internal Medicine, Medical School, National and Kapodistrian University of Athens, Laiko General Hospital, Athens, Greece.
| | - Dimitrios Tsilingiris
- First Department of Propaedeutic Internal Medicine, Medical School, National and Kapodistrian University of Athens, Laiko General Hospital, Athens, Greece
| | - Carel W le Roux
- Diabetes Complications Research Centre, University College Dublin, Dublin, Ireland
| | - Francesco Rubino
- Department of Metabolic and Bariatric Surgery, Diabetes and Nutritional Science Division, King's College Hospital, London, United Kingdom
| | - Christos S Mantzoros
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, USA
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8
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Loh K, Shi YC, Bensellam M, Lee K, Laybutt DR, Herzog H. Y1 receptor deficiency in β-cells leads to increased adiposity and impaired glucose metabolism. Sci Rep 2018; 8:11835. [PMID: 30177746 PMCID: PMC6120893 DOI: 10.1038/s41598-018-30140-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 07/24/2018] [Indexed: 01/12/2023] Open
Abstract
Insulin secretion from pancreatic β-cells is critical for maintaining glucose homeostasis and deregulation of circulating insulin levels is associated with the development of metabolic diseases. While many factors have been implicated in the stimulation of insulin secretion, the mechanisms that subsequently reduce insulin secretion remain largely unexplored. Here we demonstrate that mice with β-cell specific ablation of the Y1 receptor exhibit significantly upregulated serum insulin levels associated with increased body weight and adiposity. Interestingly, when challenged with a high fat diet these β-cell specific Y1-deficient mice also develop hyperglycaemia and impaired glucose tolerance. This is most likely due to enhanced hepatic lipid synthesis, resulting in an increase of lipid accumulation in the liver. Together, our study demonstrates that Y1 receptor signaling negatively regulates insulin release, and pharmacological inhibition of Y1 receptor signalling for the treatment of non-insulin dependent diabetes should be taken into careful consideration.
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Affiliation(s)
- Kim Loh
- Neuroscience Division, Garvan Institute of Medical Research, St. Vincent's Hospital, Sydney, 2010, Australia. .,Faculty of Medicine, UNSW Australia, Sydney, 2052, Australia. .,St. Vincent's Institute of Medical Research, Fitzroy, VIC, 3065, Australia.
| | - Yan-Chuan Shi
- Neuroscience Division, Garvan Institute of Medical Research, St. Vincent's Hospital, Sydney, 2010, Australia.,Faculty of Medicine, UNSW Australia, Sydney, 2052, Australia
| | - Mohammed Bensellam
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, St. Vincent's Hospital, Sydney, 2010, Australia
| | - Kailun Lee
- Neuroscience Division, Garvan Institute of Medical Research, St. Vincent's Hospital, Sydney, 2010, Australia.,Diabetes and Metabolism Division, Garvan Institute of Medical Research, St. Vincent's Hospital, Sydney, 2010, Australia.,Faculty of Medicine, UNSW Australia, Sydney, 2052, Australia
| | - D Ross Laybutt
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, St. Vincent's Hospital, Sydney, 2010, Australia.,Faculty of Medicine, UNSW Australia, Sydney, 2052, Australia
| | - Herbert Herzog
- Neuroscience Division, Garvan Institute of Medical Research, St. Vincent's Hospital, Sydney, 2010, Australia. .,Faculty of Medicine, UNSW Australia, Sydney, 2052, Australia.
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9
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Inhibition of Y1 receptor signaling improves islet transplant outcome. Nat Commun 2017; 8:490. [PMID: 28887564 PMCID: PMC5591241 DOI: 10.1038/s41467-017-00624-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 07/13/2017] [Indexed: 02/08/2023] Open
Abstract
Failure to secrete sufficient quantities of insulin is a pathological feature of type-1 and type-2 diabetes, and also reduces the success of islet cell transplantation. Here we demonstrate that Y1 receptor signaling inhibits insulin release in β-cells, and show that this can be pharmacologically exploited to boost insulin secretion. Transplanting islets with Y1 receptor deficiency accelerates the normalization of hyperglycemia in chemically induced diabetic recipient mice, which can also be achieved by short-term pharmacological blockade of Y1 receptors in transplanted mouse and human islets. Furthermore, treatment of non-obese diabetic mice with a Y1 receptor antagonist delays the onset of diabetes. Mechanistically, Y1 receptor signaling inhibits the production of cAMP in islets, which via CREB mediated pathways results in the down-regulation of several key enzymes in glycolysis and ATP production. Thus, manipulating Y1 receptor signaling in β-cells offers a unique therapeutic opportunity for correcting insulin deficiency as it occurs in the pathological state of type-1 diabetes as well as during islet transplantation.Islet transplantation is considered one of the potential treatments for T1DM but limited islet survival and their impaired function pose limitations to this approach. Here Loh et al. show that the Y1 receptor is expressed in β- cells and inhibition of its signalling, both genetic and pharmacological, improves mouse and human islet function.
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10
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Khan D, Vasu S, Moffett RC, Irwin N, Flatt PR. Influence of neuropeptide Y and pancreatic polypeptide on islet function and beta-cell survival. Biochim Biophys Acta Gen Subj 2017; 1861:749-758. [PMID: 28069397 DOI: 10.1016/j.bbagen.2017.01.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 01/03/2017] [Accepted: 01/04/2017] [Indexed: 01/06/2023]
Abstract
BACKGROUND In the present study we assessed the impact of neuropeptide Y receptor (NPYR) modulators, neuropeptide Y (NPY) and pancreatic polypeptide (PP), on islet function and beta-cell survival. METHODS The effects of NPY and PP on beta-cell function were examined in BRIN BD11 and 1.1B4 beta-cells, as well as isolated mouse islets. Involvement of both peptides in pancreatic islet adaptations to streptozotocin and hydrocortisone, as well as effects on beta-cell proliferation and apoptosis was also evaluated. RESULTS Neither NPY nor PP affected in vivo glucose disposal or insulin secretion in mice. However, both peptides inhibited (p<0.05 to p<0.001) glucose stimulated insulin secretion from rat and human beta-cells. NPY exerted similar insulinostatic effects in isolated mouse islets. NPY and PP inhibited alanine-induced changes in BRIN BD11 cell membrane potential and (Ca2+)i. Streptozotocin treatment decreased and hydrocortisone treatment increased beta-cell mass in mice. In addition, streptozotocin, but not hydrocortisone, increased PP cell area. Streptozotocin also shifted the normal co-localisation of NPY with PP, towards more pronounced co-expression with somatostatin in delta-cells. Both streptozotocin and hydrocortisone increased pancreatic exocrine expression of NPY. More detailed in vitro investigations revealed that NPY, but not PP, augmented (p<0.01) BRIN BD11 beta-cell proliferation. In addition, both peptides exerted protective effects against streptozotocin-induced DNA damage in beta-cells. CONCLUSION These data emphasise the involvement of PP, and particularly NPY, in the regulation of beta-cell mass and function. GENERAL SIGNIFICANCE Modulation of PP and NPY signalling is suitable for further evaluation and possible clinical development for the treatment of diabetes.
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Affiliation(s)
- Dawood Khan
- SAAD Centre for Pharmacy and Diabetes, Ulster University, Coleraine, Northern Ireland, UK
| | - Srividya Vasu
- SAAD Centre for Pharmacy and Diabetes, Ulster University, Coleraine, Northern Ireland, UK
| | - R Charlotte Moffett
- SAAD Centre for Pharmacy and Diabetes, Ulster University, Coleraine, Northern Ireland, UK
| | - Nigel Irwin
- SAAD Centre for Pharmacy and Diabetes, Ulster University, Coleraine, Northern Ireland, UK.
| | - Peter R Flatt
- SAAD Centre for Pharmacy and Diabetes, Ulster University, Coleraine, Northern Ireland, UK
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Ramesh N, Mortazavi S, Unniappan S. Nesfatin-1 stimulates cholecystokinin and suppresses peptide YY expression and secretion in mice. Biochem Biophys Res Commun 2016; 472:201-8. [PMID: 26920055 DOI: 10.1016/j.bbrc.2016.02.095] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 02/22/2016] [Indexed: 12/12/2022]
Abstract
Nesfatin-1 is an 82 amino acid secreted peptide encoded in the precursor, nucleobindin-2 (NUCB2). It is an insulinotropic anorexigen abundantly expressed in the stomach and hypothalamus. Post-prandial insulin secretion is predominantly regulated by incretins glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). Nesfatin-1 was previously reported to modulate GLP-1 and GIP secretion in vitro in an enteroendocrine (STC-1) cell line. Intestine is a source of additional hormones including cholecystokinin (CCK) and peptide YY (PYY) that regulate metabolism. We hypothesized that nesfatin-1 modulates CCK and PYY secretion. Immunofluorescence histochemistry showed NUCB2/nesfatin-1 co-localizing CCK and PYY in the intestinal mucosa of mice. Static incubation of STC-1 cells with nesfatin-1 upregulated both CCK mRNA expression (1 and 10 nM) and secretion (0.1, 1 and 10 nM) at 1 h post-incubation. In contrast, nesfatin-1 treatment for 1 h downregulated PYY mRNA expression (all doses tested) and secretion (0.01 and 0.1 nM) in STC-1 cells. Continuous infusion of nesfatin-1 using osmotic mini-pumps for 12 h upregulated CCK mRNA expression in large intestine, and downregulated PYY mRNA expression in both large and small intestines of male C57BL/6J mice. In these tissues, Western blot analysis found a corresponding increase in CCK and a decrease in PYY content. Collectively, we provide new information on the cell specific localization of NUCB2/nesfatin-1 in the intestinal mucosa, and a novel function for nesfatin-1 in modulating intestinal CCK and PYY expression and secretion in mice.
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Affiliation(s)
- Naresh Ramesh
- Laboratory of Integrative Neuroendocrinology, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan S7N 5B4, Canada
| | - Sima Mortazavi
- Laboratory of Integrative Neuroendocrinology, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan S7N 5B4, Canada
| | - Suraj Unniappan
- Laboratory of Integrative Neuroendocrinology, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan S7N 5B4, Canada.
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12
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Toräng S, Bojsen-Møller KN, Svane MS, Hartmann B, Rosenkilde MM, Madsbad S, Holst JJ. In vivo and in vitro degradation of peptide YY3-36 to inactive peptide YY3-34 in humans. Am J Physiol Regul Integr Comp Physiol 2016; 310:R866-74. [PMID: 26818056 DOI: 10.1152/ajpregu.00394.2015] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 01/25/2016] [Indexed: 11/22/2022]
Abstract
Peptide YY (PYY) is a 36-amino-acid peptide released from enteroendocrine cells upon food intake. The NH2 terminally truncated metabolite, PYY3-36, exerts anorexic effects and has received considerable attention as a possible antiobesity drug target. The kinetics and degradation products of PYY metabolism are not well described. A related peptide, neuropeptide Y, may be degraded from the COOH terminus, and in vivo studies in pigs revealed significant COOH-terminal degradation of PYY. We therefore investigated PYY metabolism in vitro after incubation in human blood and plasma and in vivo after infusion of PYY1-36 and PYY3-36 in eight young, healthy men. A metabolite, corresponding to PYY3-34, was formed after incubation in plasma and blood and during the infusion of PYY. PYY3-34 exhibited no agonistic or antagonistic effects on the Y2 receptor. PYY1-36 infused with and without coadministration of sitagliptin was eliminated with half-lives of 10.1 ± 0.5 and 9.4 ± 0.8 min (means ± SE) and metabolic clearance rates of 15.7 ± 1.5 and 14.1 ± 1.1 ml·kg(-1)·min(-1) after infusion, whereas PYY3-36 was eliminated with a significantly longer half-life of 14.9 ± 1.3 min and a metabolic clearance rate of 9.4 ± 0.6 ml·kg(-1)·min(-1) We conclude that, upon intravenous infusion in healthy men, PYY is inactivated by cleavage of the two COOH-terminal amino acids. In healthy men, PYY3-36 has a longer half-life than PYY1-36.
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Affiliation(s)
- Signe Toräng
- Department of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark; NNF Center for Basic Metabolic Research, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Kirstine Nyvold Bojsen-Møller
- NNF Center for Basic Metabolic Research, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark; Department of Endocrinology, Hvidovre Hospital, Kettegårds Allé, Hvidovre, Denmark; and
| | - Maria Saur Svane
- NNF Center for Basic Metabolic Research, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark; Department of Endocrinology, Hvidovre Hospital, Kettegårds Allé, Hvidovre, Denmark; and
| | - Bolette Hartmann
- Department of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark; NNF Center for Basic Metabolic Research, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mette Marie Rosenkilde
- Department of Neuroscience and Pharmacology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sten Madsbad
- NNF Center for Basic Metabolic Research, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark; Department of Endocrinology, Hvidovre Hospital, Kettegårds Allé, Hvidovre, Denmark; and
| | - Jens Juul Holst
- Department of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark; NNF Center for Basic Metabolic Research, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark;
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Chandarana K, Gelegen C, Irvine EE, Choudhury AI, Amouyal C, Andreelli F, Withers DJ, Batterham RL. Peripheral activation of the Y2-receptor promotes secretion of GLP-1 and improves glucose tolerance. Mol Metab 2013; 2:142-52. [PMID: 24049729 DOI: 10.1016/j.molmet.2013.03.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Revised: 03/04/2013] [Accepted: 03/05/2013] [Indexed: 12/15/2022] Open
Abstract
The effect of peptide tyrosine-tyrosine (PYY) on feeding is well established but currently its role in glucose homeostasis is poorly defined. Here we show in mice, that intraperitoneal (ip) injection of PYY3-36 or Y2R agonist improves nutrient-stimulated glucose tolerance and enhances insulin secretion; an effect blocked by peripheral, but not central, Y2R antagonist administration. Studies on isolated mouse islets revealed no direct effect of PYY3-36 on insulin secretion. Bariatric surgery in mice, enterogastric anastomosis (EGA), improved glucose tolerance in wild-type mice and increased circulating PYY and active GLP-1. In contrast, in Pyy-null mice, post-operative glucose tolerance and active GLP-1 levels were similar in EGA and sham-operated groups. PYY3-36 ip increased hepato-portal active GLP-1 plasma levels, an effect blocked by ip Y2R antagonist. Collectively, these data suggest that PYY3-36 therefore acting via peripheral Y2R increases hepato-portal active GLP-1 plasma levels and improves nutrient-stimulated glucose tolerance.
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Key Words
- AUC, area under the curve
- CNS, central nervous system
- DPP-4, di-peptidyl peptidase-4
- EGA, entero-gastric anastomosis
- GLP-1
- Glucose homeostasis
- HFD, high-fat diet
- ICV, intracerebroventricular
- IPGTT, intraperitoneal glucose tolerance test
- PYY
- PYY, peptide tyrosine–tyrosine
- T2DM, type 2 diabetes mellitus
- WT, wild-type
- Y2-receptor
- Y2R, Y2-receptor
- aCSF, artificial cerebrospinal fluid
- active GLP-1, glucagon-like peptide-1(7-36)amide
- ip, intraperitoneal
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Affiliation(s)
- Keval Chandarana
- Centre for Obesity Research, Department of Medicine, University College London, Rayne Institute, 5 University Street, WC1E 6JJ, London, UK
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14
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Boey D, Sainsbury A, Herzog H. The role of peptide YY in regulating glucose homeostasis. Peptides 2007; 28:390-5. [PMID: 17210210 DOI: 10.1016/j.peptides.2006.07.031] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2006] [Accepted: 07/30/2006] [Indexed: 01/17/2023]
Abstract
The gut-derived hormone peptide YY (PYY) is most commonly known for its effect on satiety, decreasing food intake and body weight in animals and humans. However, PYY is also involved in a wide range of digestive functions including regulating insulin secretion and glucose homeostasis. Over the last few years, there have been several interesting clinical and animal studies investigating the role of PYY in glucose homeostasis. This review aims to present an updated summary of findings over the last few decades highlighting the role of PYY in regulating insulin output and insulin sensitivity, and the potential mechanisms involved.
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Affiliation(s)
- Dana Boey
- Neuroscience Research Program, Garvan Institute of Medical Research, St. Vincent's Hospital, 384 Victoria Street, Darlinghurst, Sydney, NSW 2010, Australia.
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15
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Heijboer AC, Pijl H, Van den Hoek AM, Havekes LM, Romijn JA, Corssmit EPM. Gut-brain axis: regulation of glucose metabolism. J Neuroendocrinol 2006; 18:883-94. [PMID: 17076764 DOI: 10.1111/j.1365-2826.2006.01492.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Obesity and type II diabetes mellitus have reached epidemic proportions. From this perspective, knowledge about the regulation of satiety and food intake is more important than ever. The gut releases several peptides upon feeding, which affect hypothalamic pathways involved in the regulation of satiety and metabolism. Within the hypothalamus, there are complex interactions between many nuclei of which the arcuate nucleus is considered as one of the most important hypothalamic centres that regulates food intake. The neuropeptides, which are present in the hypothalamus and are involved in regulating food intake, also play a key role in regulating glucose metabolism and energy expenditure. In synchrony with the effects of those neuropeptides, gastrointestinal hormones also affect glucose metabolism and energy expenditure. In this review, the effects of the gastrointestinal hormones ghrelin, cholecystokinin, peptide YY, glucagon-like peptide, oxyntomodulin and gastric inhibitory polypeptide on glucose and energy metabolism are reviewed. These gut hormones affect glucose metabolism at different levels: by altering food intake and body weight, and thereby insulin sensitivity; by affecting gastric delay and gut motility, and thereby meal-related fluctuations in glucose levels; by affecting insulin secretion, and thereby plasma glucose levels, and by affecting tissue specific insulin sensitivity of glucose metabolism. These observations point to the notion of a major role of the gut-brain axis in the integrative physiology of whole body fuel metabolism.
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Affiliation(s)
- A C Heijboer
- Department of Endocrinology and Metabolic Diseases, Leiden University Medical Center, Leiden, The Netherlands
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Boey D, Heilbronn L, Sainsbury A, Laybutt R, Kriketos A, Herzog H, Campbell LV. Low serum PYY is linked to insulin resistance in first-degree relatives of subjects with type 2 diabetes. Neuropeptides 2006; 40:317-24. [PMID: 17045646 DOI: 10.1016/j.npep.2006.08.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2006] [Revised: 07/25/2006] [Accepted: 08/10/2006] [Indexed: 10/24/2022]
Abstract
Low circulating peptide YY (PYY) levels are reported in obese and type II diabetic subjects and results from PYY knockout animals suggests that PYY deficiency may have a causative role in the etiology of obesity and type 2 diabetes. Here, our aims were to determine whether people with a genetic predisposition to developing type 2 diabetes and obesity differ from otherwise similar subjects without such family history, in fasting or meal-related PYY levels, fasting insulin, insulin secretion (HOMA-B) and insulin sensitivity. We also investigated whether PYY ablation affects the intrinsic ability of islets to secrete insulin, which may be a contributing factor to the hyperinsulinemia observed in PYY knockout mice. Healthy female first-degree relatives of people with type 2 diabetes were matched for age, gender and BMI to control subjects but had significantly lower insulin sensitivity (p<0.05). Relatives also had significantly lower fasting serum PYY levels than controls (p<0.05), but their PYY response to a high fat meal (4250 kJ, 73% fat) was not significantly different. Fasting PYY level correlated positively with glucose infusion rate (r=0.713, p=0.002) and fasting adiponectin (r=0.5, p=0.02). Islets of Langerhans from PYY knockout mice were found to hypersecrete insulin in response to 25 mM glucose (p<0.05). These data demonstrate that lack of PYY enhances insulin secretion from the Islets of Langerhans and that low fasting PYY levels are associated with insulin resistance in humans. Together, these findings suggest that low circulating levels of PYY could contribute to hyperinsulinemia and insulin resistance, and possibly contribute to subsequent development of obesity and type 2 diabetes.
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Affiliation(s)
- Dana Boey
- Neuroscience Research Program, Garvan Institute of Medical Research, Sydney, NSW 2010, Australia
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17
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Torekov SS, Larsen LH, Glümer C, Borch-Johnsen K, Jørgensen T, Holst JJ, Madsen OD, Hansen T, Pedersen O. Evidence of an association between the Arg72 allele of the peptide YY and increased risk of type 2 diabetes. Diabetes 2005; 54:2261-5. [PMID: 15983231 DOI: 10.2337/diabetes.54.7.2261] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
We tested the hypothesis that variants in the gene encoding the prepropeptide YY (PYY) associate with type 2 diabetes and/or obesity. Mutation analyses of DNA from 84 patients with obesity and familial type 2 diabetes identified two polymorphisms, IVS3 + 68C>T and Arg72Thr, and one rare variant, +151C>A of PYY. The common allele of the Arg72Thr variant associated with type 2 diabetes with an allele frequency of the Arg allele of 0.667 (95% CI 0.658-0.677) among 4,639 glucose-tolerant subjects and 0.692 (0.674-0.710) among 1,326 patients with type 2 diabetes (P = 0.005, odds ratio 1.19 [95% CI 1.05-1.35]). The same polymorphism associated with overweight (25 < or = BMI < 30 kg/m2) (P = 0.018, 1.15 [1.02-1.28]). In quantitative trait analyses of a population-based sample of 6,022 subjects, the Arg allele was associated with an increased plasma glucose level 2 h after an oral glucose tolerance test (OGTT) (P = 0.03), an increased area under the curve for the post-OGTT plasma glucose level (P = 0.03), and a lower insulinogenic index (P = 0.01). In conclusion, the common Arg allele of the PYY Arg72Thr variant modestly associates with type 2 diabetes and with type 2 diabetes-related quantitative traits.
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Affiliation(s)
- Signe S Torekov
- Steno Diabetes Center, Niels Steensens Vej 2, DK-2820, Gentofte, Denmark.
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Barroso I, Luan J, Middelberg RPS, Harding AH, Franks PW, Jakes RW, Clayton D, Schafer AJ, O'Rahilly S, Wareham NJ. Candidate gene association study in type 2 diabetes indicates a role for genes involved in beta-cell function as well as insulin action. PLoS Biol 2003; 1:E20. [PMID: 14551916 PMCID: PMC212698 DOI: 10.1371/journal.pbio.0000020] [Citation(s) in RCA: 226] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2003] [Accepted: 08/08/2003] [Indexed: 01/24/2023] Open
Abstract
Type 2 diabetes is an increasingly common, serious metabolic disorder with a substantial inherited component. It is characterised by defects in both insulin secretion and action. Progress in identification of specific genetic variants predisposing to the disease has been limited. To complement ongoing positional cloning efforts, we have undertaken a large-scale candidate gene association study. We examined 152 SNPs in 71 candidate genes for association with diabetes status and related phenotypes in 2,134 Caucasians in a case-control study and an independent quantitative trait (QT) cohort in the United Kingdom. Polymorphisms in five of 15 genes (33%) encoding molecules known to primarily influence pancreatic beta-cell function-ABCC8 (sulphonylurea receptor), KCNJ11 (KIR6.2), SLC2A2 (GLUT2), HNF4A (HNF4alpha), and INS (insulin)-significantly altered disease risk, and in three genes, the risk allele, haplotype, or both had a biologically consistent effect on a relevant physiological trait in the QT study. We examined 35 genes predicted to have their major influence on insulin action, and three (9%)-INSR, PIK3R1, and SOS1-showed significant associations with diabetes. These results confirm the genetic complexity of Type 2 diabetes and provide evidence that common variants in genes influencing pancreatic beta-cell function may make a significant contribution to the inherited component of this disease. This study additionally demonstrates that the systematic examination of panels of biological candidate genes in large, well-characterised populations can be an effective complement to positional cloning approaches. The absence of large single-gene effects and the detection of multiple small effects accentuate the need for the study of larger populations in order to reliably identify the size of effect we now expect for complex diseases.
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Abstract
The present status of our understanding of the feedback regulation of pancreatic secretion by peptide YY (PYY) released from the distal intestine is reviewed. Exocrine pancreatic secretion is primarily controlled by the cephalic (the vagus nerve), gastric (acid and pepsin secretion, and nutrients delivered into the duodenum by gastric emptying), and intestinal (secretin and CCK) mechanisms. PYY acts on the multiple sites in the brain and gut, and inhibits pancreatic secretion by regulating these primary control mechanisms. The involvement of Y(1) and Y(2) receptors has been suggested in the regulation of pancreatic secretion. However, it remains to be studied which site of action or receptor subtype is physiologically most important for this regulation.
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Affiliation(s)
- Satoru Naruse
- Internal Medicine II, Nagoya University School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
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Chance WT, Zhang X, Zuo L, Balasubramaniam A. Reduction of gut hypoplasia and cachexia in tumor-bearing rats maintained on total parenteral nutrition and treated with peptide YY and clenbuterol. Nutrition 1998; 14:502-7. [PMID: 9646290 DOI: 10.1016/s0899-9007(98)00038-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Prevention of gut hypoplasia associated with total parenteral nutrition (TPN) was investigated in 67 adult male Fisher 344 rats. Mass and protein content of the small intestine was reduced by 31% and 39%, respectively, after 7 d of TPN in tumor-bearing (TB) rats. Coinfusing peptide YY (PYY; 1 nmol.kg-1.h-1) and treating the rats with the anabolic beta-adrenergic agonist, clenbuterol (CLE; 2 mg.kg-1.d-1), resulted in significant savings in small intestine weight (26% increase) and protein (42% increase). Although the colon also exhibited a significant decrease in mass (31%), none of the treatment combinations were effective in this region of the gut. Histologic analysis of ileum suggested that the additive effects of PYY and CLE were due to differential effects of these compounds on mucosal and muscular tissues, respectively. This combination of treatments also resulted in significant savings (30% increase) in gastrocnemius protein, suggesting a reduction in the cachectic response. These results suggest that TPN-induced gut hypoplasia and cancer cachexia may be reduced by the proper combination of nutritional, hormonal, and pharmacologic treatments. In addition, the anabolic effects of various treatments may be additive to counteract TPN-induced gut atrophy.
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Affiliation(s)
- W T Chance
- Department of Surgery, University of Cincinnati Medical Center, Ohio 45267-0558, USA
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Chance WT, Zhang X, Balasubramaniam A, Fischer JE. Preservation of intestine protein by peptide YY during total parenteral nutrition. Life Sci 1996; 58:1785-94. [PMID: 8637404 DOI: 10.1016/0024-3205(96)00162-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Maintaining rats on TPN for 7 days was associated with a 50% reduction in gut mass and protein content. Co-infusing PYY with total parenteral nutrition (TPN) resulted in significant savings in jejunal wet mass and elevated protein content of jejunum, ileum and colon as compared with rats maintained on TPN alone. No significant effects of PYY on plasma amino acid profile were noted. Although minor alterations in mucosal polyamines were observed in rats maintained on TPN, co-infusion of PYY had no significant effect on gut polyamine concentrations. These results suggest that PYY has trophic effects upon the gut during otherwise catabolic conditions. Therefore, co-infusion of PYY with TPN may suggest methods whereby loss of intestinal mucosa and atrophy-associated complications of TPN may be modulated.
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Affiliation(s)
- W T Chance
- Veterans Affairs Medical Center, Cincinnati, OH, USA
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22
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Liu CD, Rongione AJ, Garvey L, Balasubramaniam A, McFadden DW. Adjuvant hormonal treatment with peptide YY or its analog decreases human pancreatic carcinoma growth. Am J Surg 1996; 171:192-6. [PMID: 8554139 DOI: 10.1016/s0002-9610(99)80098-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Recent studies have revealed decreased pancreatic cancer cell growth upon administration of peptide YY (PYY). We examined whether adjuvant treatment with PYY or its synthetic analog, BIM-43004, would decrease human pancreatic adenocarcinoma growth. MATERIALS AND METHODS Human pancreatic ductal adenocarcinomas, MiaPaCa-2 and BxPC-3, were cultured and assessed for growth by MTT assay. Pancreatic cancer cells received 500 pmol of PYY or BIM-43004 for 24 hours prior to 5-fluorouracil (5-FU; 10 micrograms/mL) and leucovorin (40 micrograms/mL) administration. Cell membrane epidermal growth factor (EGF) receptors were analyzed by Western blotting after exposure to peptides and chemotherapy. RESULTS Cancer cell growth was reduced in all groups receiving hormonal pretreatment (23% PYY/5-FU/leucovorin versus control; 27% BIM-43004/5-FU/leucovorin versus control) as compared with groups receiving 5-FU and leucovorin only (16% versus control). The EGF receptor expression was reduced by 30% in cells treated with PYY/5-FU/leucovorin and by 45% in cells treated with BIM/5-FU/leucovorin as compared with control cells without treatment. CONCLUSION Human pancreatic cancer cell growth is further decreased when pretreated with PYY or its synthetic analog prior to chemotherapy.
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Affiliation(s)
- C D Liu
- Department of Surgery, UCLA Center for Health Sciences, USA
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Nieuwenhuizen AG, Karlsson S, Fridolf T, Ahrén B. Mechanisms underlying the insulinostatic effect of peptide YY in mouse pancreatic islets. Diabetologia 1994; 37:871-8. [PMID: 7806016 DOI: 10.1007/bf00400941] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Peptide YY is an insulinostatic peptide which is released into the circulation from the intestinal mucosa upon food intake. Peptide YY is also co-stored with glucagon in the secretory granules of the pancreatic alpha cells. We examined the mechanisms underlying the insulinostatic effect of peptide YY in isolated mouse pancreatic islets. We found that peptide YY (0.1 nmol/l-1 mumol/l) inhibited glucose (11.1 mmol/l)-stimulated insulin secretion from incubated isolated islets, with a maximal inhibition of approximately 70% observed at a dose of 1 nmol/l (p < 0.001). Also in perifused islets the peptide (1 nmol/l) inhibited insulin secretion in response to 11.1 mmol/l glucose (p < 0.001). Furthermore, peptide YY inhibited glucose-stimulated cyclic AMP formation (by 67%, p < 0.05), and insulin secretion stimulated by dibutyryl cyclic AMP (p < 0.01). In contrast, the peptide was without effect both on the cytoplasmic Ca2+ concentration in dispersed mouse islet-cell suspensions as measured by the FURA 2-AM technique, and on insulin release in isolated islets, when stimulated by the protein kinase C-activator 12-O-tetradecanoyl phorbol 13-acetate. Finally, in pre-labelled perifused islets, peptide YY caused a small and transient increase in the 86Rb+ efflux (p < 0.001), but only in the absence of extracellular Ca2+. We conclude that peptide YY inhibits glucose-stimulated insulin secretion from isolated mouse islets by inhibiting two different steps in the cyclic AMP cascade, that is, both the accumulation and the action of the cyclic nucleotide.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- A G Nieuwenhuizen
- Department of Medicine, University of Lund, Malmö General Hospital, Sweden
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