Hals 2013 J Diabetes Res
|Hals IK, Rokstad AM, Strand BL, Oberholzer J, Grill V (2013) Alginate microencapsulation of human islets does not increase susceptibility to acute hypoxia. J Diabetes Res 2013:374925.|
Abstract: Islet transplantation in diabetes is hampered by the need of life-long immunosuppression. Encapsulation provides partial immunoprotection but could possibly limit oxygen supply, a factor that may enhance hypoxia-induced beta cell death in the early post-transplantation period. Here we tested susceptibility of alginate microencapsulated human islets to experimental hypoxia (0.1-0.3 % O2 for 8 h, followed by re-oxygenation) on viability and functional parameters. Hypoxia reduced viability as measured by MTT by 33.8 ± 3.5 % in encapsulated and 42.9 ± 5.2 % in non-encapsulated islets (p < 0.2). Non-encapsulated islets released 37.7% (median) more HMGB1 compared to encapsulated islets after hypoxic culture conditions (p < 0.001). Glucose-induced insulin release was marginally affected by hypoxia. Basal oxygen consumption was equally reduced in encapsulated and non-encapsulated islets, by 22.0 ± 6.1 % vs. 24.8 ± 5.7 %. Among 27 tested cytokines/chemokines, hypoxia increased the secretion of IL-6 and IL-8/CXCL8 in both groups of islets whereas an increase of MCP-1/CCL2 was seen only with non-encapsulated islets. Conclusion: alginate microencapsulation of human islets does not increase susceptibility to acute hypoxia. This is a positive finding in relation to potential use of encapsulation for islet transplantation.
• Keywords: Human islets, Microencapsulation, Hypoxia, Viability, Oxygen consumption, Insulin release, Cytokine/chemokine secretion
• O2k-Network Lab: NO Trondheim Grill V
Labels: MiParea: Respiration, mt-Medicine
Stress:Ischemia-reperfusion Organism: Human Tissue;cell: Islet cell;pancreas;thymus Preparation: Intact cells
Coupling state: ROUTINE, ET Pathway: N, ROX HRR: Oxygraph-2k