OBJECTIVETo understand and improve the transdifferentiation of pancreatic stem cells into islet cells through isolation, cultivation and transdifferentiation of adult human pancreatic duct cells.

METHODSA portion of adult human pancreas was digested with collagenase, followed by incontinuous density gradient to separate islets from the acinar and ductal tissue. Duct epithelial cells were cultivated in CMRL1066 and then in serum-free DMEM/F12 medium with the addition of growth factors for 27 days. Samples were taken at different time points for light and electron microscopic examination and for immunocytochemical study with antibodies against transdifferentiation gene PDX-1 and protein CK-19. Amylase and insulin contents in the medium were assayed.

RESULTSA large number of duct epithelial cells were harvested after the isolation of islets. Some duct epithelial cells were PDX-1 and CK-19 positive at day one and duct epithelial cells proliferated and expanded rapidly and then transdifferentiated into stem cells and finally 3D islets. 760 islets were harvested from each gram of pancreatic tissue on day 27.

CONCLUSIONSAdult pancreatic duct cells are potential stem cells and could be transdifferentiated into islet cells in vitro under appropriate conditions.