Abstract

BACKGROUND
Despite a recent breakthrough in human islet transplantation for treating diabetes mellitus, the limited availability of insulin-producing tissue is still a major obstacle. This has led to a search for alternative sources of transplantable insulin-producing cells including pancreatic duct cells. We aimed to establish in vitro culture of pancreatic duct cells from a partial pancreas tissue in human, which could be harnessed to differentiate into pancreatic beta cells. METHODS: We isolated pancreatic duct cells from small pieces of pancreas tissue (1~3 g) derived from non-diabetic humans (n = 8) undergoing pancreatic surgery due to cancer. Pancreas tissue was finely minced after injection of collagenase P into the parenchyma. The mince was incubated in a shaking water bath at 37degrees C for 25 min and passed through a 150 micrometer mesh. The released cells were recovered, washed, and plated in a dish containing CMRL culture medium with serum. RESULTS: Isolated pancreatic cells grew in monolayer and became confluent in 1~2 wks showing typical epithelial cobblestone morphology. Immunochemistry demonstrated that ~90% of the cultured cells were cytokeratin7-positive duct cells. To induce beta cell differentiation, the cells were incubated in DMEM/F12 culture medium without serum. In addition, treatment with Matrigel overlay, exendin-4, cholera toxin or forskolin was done. Though beta cell differentiation was found by immunostaining and RT-PCR, the differentiation efficiency was very low. Over-expression of neurogenin-3 by recombinant adenovirus did not increase beta cell differentiation of the cultured duct cells significantly. CONCLUSION: We established in vitro culture of pancreatic duct cells from a partial pancreas tissue in human, which differentiate into pancreatic cells. However, a strategy to optimize beta cell differentiation in this model is needed.

• Keywords: Beta cell;Differentiation;Islet;Islet transplantation;Pancreatic duct cells