Abstract
Neonatal and juvenile porcine islet cell clusters (ICC) present an unlimited source for islet xenotransplantation to treat type 1 diabetes patients. We isolated ICC from pancreata of 14days old juvenile piglets and characterized their maturation by immunofluorescence and insulin secretion assays. Multipotent mesenchymal stromal cells derived from exocrine tissue of same pancreata (pMSC) were characterized for their differentiation potential and ability to sustain ICC insulin secretion in vitro and in vivo. Isolation of ICC resulted in 142±50×103 IEQ per pancreas. Immunofluorescence staining revealed increasing presence of insulin-positive beta cells between day 9 and 21 in culture and insulin content per 500IEC of ICC increased progressively over time from 1178.4±450µg/L to 4479.7±1954.2µg/L from day 7 to 14, P<.001. Highest glucose-induced insulin secretion by ICC was obtained at day 7 of culture and reached a fold increase of 2.9±0.4 compared to basal. Expansion of adherent cells from the pig exocrine tissue resulted in a homogenous CD90+ , CD34- , and CD45- fibroblast-like cell population and differentiation into adipocytes and chondrocytes demonstrated their multipotency. Insulin release from ICC was increased in the presence of pMSC and dependent on cell-cell contact (glucose-induced fold increase: ICC alone: 1.6±0.2; ICC+pMSC+contact: 3.2±0.5, P=.0057; ICC+pMSC no-contact: 1.9±0.3; theophylline stimulation: alone: 5.4±0.7; pMSC+contact: 8.4±0.9, P=.013; pMSC no-contact: 5.2±0.7). After transplantation of encapsulated ICC using Ca2+ -alginate (alg) microcapsules into streptozotocin-induced diabetic and immunocompetent mice, transient normalization of glycemia was obtained up to day 7 post-transplant, whereas ICC co-encapsulated with pMSC did not improve glycemia and showed increased pericapsular fibrosis. We conclude that pMSC derived from juvenile porcine exocrine pancreas improves insulin secretion of ICC by direct cell-cell contact. For transplantation purposes, the use of pMSC to support beta-cell function will depend on the development of new anti-fibrotic polymers and/or on genetically modified pigs with lower immunogenicity.
Highlights
It is currently recognized that type 1 diabetes (T1D) patients presenting long-term complications can be treated by allotransplantation of human islets
Cell clusters derived from the neonatal porcine are called either, neonatal porcine islets (NPI), porcine neonatal pancreatic cell clusters (NPCCs) or neonatal porcine islet-like cluster (NPICC).[4,5,6,7]
islet cell cluster (ICC) mature after transplantation into immuno-deficient diabetic mice, where they respond poorly to glucose for several weeks before restoring normoglycaemia after 4-10 weeks depending on the amount of ICC transplanted.[12,13,14]
Summary
It is currently recognized that type 1 diabetes (T1D) patients presenting long-term complications can be treated by allotransplantation of human islets. The limited availability of human organ donors is a major hurdle for this clinical application and has driven investigation to find other sources for islets or beta cells, including xenogenic islets isolated from porcine fetal, neonatal, or adult pancreases.[2] The isolation of islets from adult pigs is highly inefficient due to their fragility and in contrast, protocols for the digestion of fetal, neonatal, or juvenile pancreas allow to obtain high amounts of pancreatic cell clusters or islet-like clusters.[3] Cell clusters derived from the neonatal porcine are called either, neonatal porcine islets (NPI), porcine neonatal pancreatic cell clusters (NPCCs) or neonatal porcine islet-like cluster (NPICC).[4,5,6,7] We will use the term of islet cell cluster (ICC). We performed co-encapsulation and transplantation of ICC with pMSC into immunocompetent mice to analyze their effect on graft function
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
