53 - Freie Mitteilung
Inflammation & transplantation
16. Mai 2019, 10:15 - 11:45, Szenario 1, 5. OG
Combination of neonatal porcine islets with mesenchymal stem cells of human and porcine origin improves islet function
C. Gonelle-Gispert1, A. Balaphas1, J. Meyer1, E. Montanari1, L. Szabo2, S. Gerber2, L. Bühler1, Presenter: C. Gonelle-Gispert1 (1Geneva, 2Lausanne)
Neonatal porcine islets (NPIs) represent an unlimited source for islet xenotransplantation in type 1 Diabetes patients, despite limited function of neonatal tissue. We analyzed human bone marrow mesenchymal stem cells (hMSC) and pig exocrine tissue-derived MSC (pMSC) for their effects on islet function prior and after encapsulation.
Pancreases were recovered from neonatal pigs and NPIs isolated by slicing, collagenase digestion and culture for maturation. Maturation of NPI was followed by Immunofluorescence studies and insulin secretion assay. pMSC were expanded and characterized by FACS. Insulin secretion assays of NPI co-cultured and co-encapsulated with MSC from human and pigs were performed to analyze their functionality.
Isolation of neonatal pancreases resulted in yields of 340’000 ± 160'000 IEQ (obtained from 3 pancreases in 5 experiments). Immunofluorescence staining of NPIs revealed increasing insulin + ꞵ-cells between day 9 and 21 in culture. Insulin content of NPI incrased progressively over time from 27.8 ± 11.47µg/l to 2466 ± 637.9 µg/l, at days 3 and 14, respectively, for 500 IE, p< 0.001). Culture and expansion of adherent cells from the pig exocrine tissue resulted in a homogenous CD90+, CD34- and CD45- fibroblast-like population. Differentiation of these cells into adipocytes and chondrocytes showed their multipotentency. Secretion assays showed an increased insulin release from NPIs only when these were in cell-cell contact with MSC (for hMSC fold increase : 1.97±0.27, for pMSC fold increase : 4.04 ± 1.1, p<0.001) whereas without direct contact, insulin stimulation was not increased. Secretion assays performed on NPIs co-encapsulated with hMSC or pMSC in Ca2+-alginate microspheres after 3 days of encapsulation showed enhanced insulin secretion compared to NPIs encapsulated alone.
MSC of human and porcine origin significantly enhance insulin secretion of NPIs when co-cultured in direct contact. Encapsulation of NPIs with MSC should be considered for clinical application.