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Islet distribution of Peptide YY and its regulatory role in primary mouse islets and immortalised rodent and human beta-cell function and survival.

Khan, D, Vasu, Srividya, Moffett, Charlotte, Irwin, Nigel and Flatt, Peter (2016) Islet distribution of Peptide YY and its regulatory role in primary mouse islets and immortalised rodent and human beta-cell function and survival. Molecular and Cellular Endocrinology, 436 . pp. 102-113. [Journal article]

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URL: http://dx.doi.org/10.1016/j.mce.2016.07.020

DOI: 10.1016/j.mce.2016.07.020

Abstract

Recent evidence suggests that the classic gut peptide, Peptide YY (PYY), could play a fundamental role in endocrine pancreatic function. In the present study expression of PYY and its NPY receptors on mouse islets and immortalised rodent and human beta-cells was examined together with the effects of both major circulating forms of PYY, namely PYY(1-36) and PYY(3-36), on beta-cell function, murine islet adaptions to insulin deficiency/resistance, as well as direct effects on cultured beta-cell proliferation and apoptosis. In vivo administration of PYY(3-36), but not PYY(1-36), markedly (p < 0.05) decreased food intake in overnight fasted mice. Neither form of PYY affected glucose disposal or insulin secretion following an i.p. glucose challenge. However, in vitro, PYY(1-36) and PYY(3-36) inhibited (p < 0.05 to p < 0.001) glucose, alanine and GLP-1 stimulated insulin secretion from immortalised rodent and human beta-cells, as well as isolated mouse islets, by impeding alterations in membrane potential, [Ca2+]i and elevations of cAMP. Mice treated with multiple low dose streptozotocin presented with severe (p < 0.01) loss of beta-cell mass accompanied by notable increases (p < 0.001) in alpha and PP cell numbers. In contrast, hydrocortisone-induced insulin resistance increased islet number (p < 0.01) and beta-cell mass (p < 0.001). PYY expression was consistently observed in alpha-, PP- and delta-, but not beta-cells. Streptozotocin decreased islet PYY co-localisation with PP (p < 0.05) and somatostatin (p < 0.001), whilst hydrocortisone increased PYY co-localisation with glucagon (p < 0.05) in mice. More detailed in vitro investigations revealed that both forms of PYY augmented (p < 0.05 to p < 0.01) immortalised human and rodent beta-cell proliferation and protected against streptozotocin-induced cytotoxicity, to a similar or superior extent as the well characterised beta-cell proliferative and anti-apoptotic agent GLP-1. Taken together, these data highlight the significance and potential offered by modulation of pancreatic islet NPY receptor signalling pathways for preservation of beta-cell mass in diabetes.

Item Type:Journal article
Keywords:Apoptosis; Beta-cell; Diabetes; NPYR; Peptide YY (PYY); Proliferation
Faculties and Schools:Faculty of Life and Health Sciences > School of Pharmacy and Pharmaceutical Science
Faculty of Life and Health Sciences > School of Biomedical Sciences
Faculty of Life and Health Sciences
Research Institutes and Groups:Biomedical Sciences Research Institute
Biomedical Sciences Research Institute > Pharmacy & Pharmaceutical Sciences
Biomedical Sciences Research Institute > Diabetes
ID Code:35628
Deposited By: Dr Nigel Irwin
Deposited On:08 Aug 2016 08:39
Last Modified:17 Oct 2017 16:25

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