AIMS/HYPOTHESIS: The blood perfusion of individual pancreatic islets is highly variable, with a subgroup of islets having high perfusion and blood vessels responsive to further blood flow increase induced by glucose. This study tested the hypothesis that there is heterogeneity between islets with regard to beta cell proliferation, function and gene expression based on differences in their blood perfusion. METHODS: Fluorescent microspheres were injected into the ascending aorta, and then microsphere-containing and non-microsphere-containing pancreatic islets were isolated for investigation. By this procedure, the 5% of islets with the greatest blood perfusion were identified for study. Islet endothelial cells were isolated separately to investigate the role of improved vascular support in the observed differences. RESULTS: The vascular network was found to be more dense and tortuous in microsphere-containing than other islets. The most highly blood-perfused islets also had a higher rate of beta cell proliferation, superior beta cell function and a markedly different gene expression from other islets. Cultured islets exposed to islet endothelial cell products had a similarly increased beta cell proliferation rate, yet significantly fewer changes in gene expression than observed in the most highly blood-perfused islets. CONCLUSIONS/ INTERPRETATION: A novel heterogeneity between islets was observed, with superior beta cell proliferation, function and gene expression in a subpopulation of islets identified by high blood perfusion. In contrast with a previously described population of low-oxygenated, sleeping islets, which are recruited into functionality when needed, the presently described heterogeneity is shown to remain in vitro after islet isolation.
AIMS/HYPOTHESIS: The blood perfusion of individual pancreatic islets is highly variable, with a subgroup of islets having high perfusion and blood vessels responsive to further blood flow increase induced by glucose. This study tested the hypothesis that there is heterogeneity between islets with regard to beta cell proliferation, function and gene expression based on differences in their blood perfusion. METHODS: Fluorescent microspheres were injected into the ascending aorta, and then microsphere-containing and non-microsphere-containing pancreatic islets were isolated for investigation. By this procedure, the 5% of islets with the greatest blood perfusion were identified for study. Islet endothelial cells were isolated separately to investigate the role of improved vascular support in the observed differences. RESULTS: The vascular network was found to be more dense and tortuous in microsphere-containing than other islets. The most highly blood-perfused islets also had a higher rate of beta cell proliferation, superior beta cell function and a markedly different gene expression from other islets. Cultured islets exposed to islet endothelial cell products had a similarly increased beta cell proliferation rate, yet significantly fewer changes in gene expression than observed in the most highly blood-perfused islets. CONCLUSIONS/ INTERPRETATION: A novel heterogeneity between islets was observed, with superior beta cell proliferation, function and gene expression in a subpopulation of islets identified by high blood perfusion. In contrast with a previously described population of low-oxygenated, sleeping islets, which are recruited into functionality when needed, the presently described heterogeneity is shown to remain in vitro after islet isolation.
Authors: Marcela Brissova; Alena Shostak; Masakazu Shiota; Peter O Wiebe; Greg Poffenberger; Jeannelle Kantz; Zhongyi Chen; Chad Carr; W Gray Jerome; Jin Chen; H Scott Baldwin; Wendell Nicholson; David M Bader; Thomas Jetton; Maureen Gannon; Alvin C Powers Journal: Diabetes Date: 2006-11 Impact factor: 9.461
Authors: Anna L Gloyn; Ewan R Pearson; Jennifer F Antcliff; Peter Proks; G Jan Bruining; Annabelle S Slingerland; Neville Howard; Shubha Srinivasan; José M C L Silva; Janne Molnes; Emma L Edghill; Timothy M Frayling; I Karen Temple; Deborah Mackay; Julian P H Shield; Zdenek Sumnik; Adrian van Rhijn; Jerry K H Wales; Penelope Clark; Shaun Gorman; Javier Aisenberg; Sian Ellard; Pål R Njølstad; Frances M Ashcroft; Andrew T Hattersley Journal: N Engl J Med Date: 2004-04-29 Impact factor: 91.245
Authors: Rafael Arrojo e Drigo; Yusuf Ali; Juan Diez; Dinesh Kumar Srinivasan; Per-Olof Berggren; Bernhard O Boehm Journal: Diabetologia Date: 2015-07-28 Impact factor: 10.122
Authors: Johanne H Ellenbroek; Hendrica A Töns; Natascha de Graaf; Cindy J Loomans; Marten A Engelse; Hans Vrolijk; Peter J Voshol; Ton J Rabelink; Françoise Carlotti; Eelco J de Koning Journal: PLoS One Date: 2013-02-18 Impact factor: 3.240