Effects of human umbilical cord serum on proliferation and insulin content of human fetal islet-like cell clusters.

BACKGROUND

Type 1 diabets is an autoimmune disease caused by the destruction of pancreatic beta-cell with an increased incidence worldwide in the closing decades of the 20th century. This study was to investigate the effects of human umbilical cord serum (UCS) on the proliferation and function of human fetal islet-like cell clusters (ICCs) in vitro.

METHODS

Eight fresh pancreatic glands obtained after induction of labor with water bag were mildly exposed to collagenase V, and the digested cells were cultured in a RPMI-1640 medium plus 10% pooled UCS or fetal calf serum (FCS) to permit cells attachment and outgrowth of ICCs.

RESULTS

In 8 consecutively explanted glands, development and proliferation of ICCs were observed. In the presence of FCS, the outgrowth of ICC took place on the top of a fibroblast monocellular layer. UCS affected less growth of fibroblasts and increased the formation of ICCs about four-fold compared with explants from the same glands maintained in FCS. In both UCS and FCS, the insulin content of the medium was variable to a certain extent and progressively declined from day 2 to day 6. Dithizone-stained ICCs in UCS suggested that most cell clusters were islet cells (beta-cells), and the purity of islets was estimated 80%-90%. The ultrastructure of the cultured cells showed a large number of granule-containing cells, most of which were identified as beta-cells.

CONCLUSION

We conclude that in comparison with explants with FCS, the yield of ICCs and purification of islet cells are markedly increased by UCS and may facilitate the proliferation of pancreatic beta-cells intended for islet transplantation.