A novel human stem cell coculture system that maintains the survival and function of culture islet-like cell clusters.

Islet-like cell clusters (ICCs) have been suggested to be a source of insulin-producing tissue for xenotransplantation in type 1 diabetes. We designed an approach to maintain the cultured rat pancreatic ICC survival and function, when cocultured with human umbilical cord mesenchymal stem cells (HUMSCs). HUMSCs in coculture have the ability to maintain ICC survival and function, for which number and insulin secretion of ICCs are increasing and lasting for 3 months, while ICCs gradually crash, which results in cell death after a period of 12 days of culture without HUMSCs. Cytokine protein array showed it has more than a twofold increase in levels of several cytokines (interleukin-6, tissue inhibitor of metalloproteinases-1, tissue inhibitor of metalloproteinases-2, monocyte chemoattractant protein-1, growth related oncogene, hepatocyte growth factor, insulin-like growth factor binding proteins 4, and interleukin-8) on coculture medium, implying an important role of these cytokines in this coculture system. These findings suggest that coculture with HUMSCs may have a significant potential to protect ICCs from damage during culture, and may be employed in a novel culture approach to maintain islet cell survival and function before transplantation.