Pancreatic Stellate Cells Prolong Ex Vivo Islet Viability and Function and Improve Engraftment

Preserving islet health and function is critical during pretransplant culture to improve islet transplantation outcome and for ex vivo modeling of diabetes for pharmaceutical drug discovery. The limited islet engraftment potential is primarily attributable to loss of extracellular matrix (ECM) support and interaction. Multipotent cells with ECM depositing competency improve islet survival during short coculture period. However, role of pancreatic stellate cells (PSCs) and their ECM support in preserving ex vivo islet physiology remains largely unknown. Here, we report novel cytoprotective effects of culture-adapted porcine PSCs and role of their ECM-mediated intercellular communication on pig, mouse and human islets ex vivo. Using direct-contact coculture system, we demonstrate that porcine PSCs preserve and significantly prolong islet viability and function from 7 +/- 3 days to more than 28 +/- 5 (P < .001) days in vitro. These beneficial effects of PSCs on islet health are not species-specific. Using NSC47924 to specifically inhibit 37/67 kDa laminin receptor (LR), we identified that LR-mediated intercellular communication is essential for PSCs to protect functional viability of islets in vitro. Finally, our results demonstrate that PSC co-transplantation improved function and enhanced capacity of syngeneic islets to reverse hyperglycemia in mice with preexisiting diabetes. Cumulatively, our findings unveil novel effects of culture-adapted PSCs on islet health likely mirroring in vivo niche interaction. Furthermore, islet and PSC coculture may aid in development of ex vivo diabetes modeling and also suggests that a combined islet-PSC tissue engineered implant may significantly improve islet transplantation outcome.