title: Improved physiological properties of gravity-enforced reassembled rat and human pancreatic pseudo-islets.
abstract: Previously we demonstrated the superiority of small islets vs large islets in terms of function and survival after transplantation, and we generated reaggregated rat islets (pseudo-islets) of standardized small dimensions by the hanging-drop culture method (HDCM). The aim of this study was to generate human pseudo-islets by HDCM and to evaluate and compare the physiological properties of rat and human pseudo-islets. Isolated rat and human islets were dissociated into single cells and incubated for 6-14 days by HDCM. Newly formed pseudo-islets were analysed for dimensions, morphology, glucose-stimulated insulin secretion (GSIS) and total insulin content. The morphology of reaggregated human islets was similar to that of native islets, while rat pseudo-islets had a reduced content of α and δ cells. GSIS of small rat and human pseudo-islets (250 cells) was increased up to 4.0-fold (p < 0.01) and 2.5-fold (p < 0.001), respectively, when compared to their native counterparts. Human pseudo-islets showed a more pronounced first-phase insulin secretion as compared to intact islets. GSIS was inversely correlated to islet size, and small islets (250 cells) contained up to six-fold more insulin/cell than large islets (1500 cells). Tissue loss with this new technology could be reduced to 49.2 ± 1.5% in rat islets, as compared to the starting amount. With HDCM, pseudo-islets of standardized size with similar cellular composition and improved biological function can be generated, which compensates for tissue loss during production. Transplantation of small pseudo-islets may represent an attractive strategy to improve graft survival and function, due to better oxygen and nutrient supply during the phase of revascularization. Copyright © 2014 John Wiley & Sons, Ltd.
authors.affiliation: Division of Endocrinology, Diabetes and Clinical Nutrition, University Hospital Zurich, Switzerland.
authors.forename: R A
authors.initials: RA
authors.lastname: Zuellig
authors.affiliation: Nephrology, Dialysis and Transplantation Unit (Stefoni), S.Orsola-Malpighi Hospital, University of Bologna, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Cavallari
authors.affiliation: Division of Endocrinology, Diabetes and Clinical Nutrition, University Hospital Zurich, Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Gerber
authors.affiliation: Division of Endocrinology, Diabetes and Clinical Nutrition, University Hospital Zurich, Switzerland.
authors.forename: O
authors.initials: O
authors.lastname: Tschopp
authors.affiliation: Division of Endocrinology, Diabetes and Clinical Nutrition, University Hospital Zurich, Switzerland.
authors.forename: G A
authors.initials: GA
authors.lastname: Spinas
authors.affiliation: InSphero AG, Schlieren, Switzerland.
authors.forename: W
authors.initials: W
authors.lastname: Moritz
authors.affiliation: Division of Endocrinology, Diabetes and Clinical Nutrition, University Hospital Zurich, Switzerland.
authors.forename: R
authors.initials: R
authors.lastname: Lehmann
mesh_terms: D000818:Animals; D002449:Cell Aggregation; D018929:Cell Culture Techniques / Q000379:methods*; D002478:Cells, Cultured; D005947:Glucose / Q000737:chemistry; D006085:Graft Survival; D006112:Gravitation; D006801:Humans; D007328:Insulin / Q000737:chemistry*; D050417:Insulin-Secreting Cells / Q000166:cytology; D007515:Islets of Langerhans / Q000166:cytology*; D008297:Male; D010100:Oxygen / Q000737:chemistry; D010477:Perfusion; D051381:Rats; D011917:Rats, Inbred Lew
chemical_list: D007328:Insulin; D005947:Glucose; D010100:Oxygen
keywords: diabetes; hanging drop; islet cell transplantation; pseudo-islets; reaggregation; survival