Long-term storage methods, such as cryopreservation and long-term in vitro culture, hinder the therapeutical application of pancreatic islet transplantation, because they decrease islet viability. Pancreatic ductal epithelial cells ( @entity6567 ) are putative stem cells for islets, which may secrete specific factors supporting islet growth and function. Hence, we studied the effect of coculture with @entity6567 on the viability of fresh and cryopreserved @entity1 pancreatic islets. Islets and @entity6567 were isolated from the pancreas of an organ donor, and part of them were cryopreserved. Fresh and cryopreserved-thawed islets were cultured alone or in the presence of @entity6567 for 14 days at 33 degrees C or 37 degrees C. At day 1 and day 14 of culture, @entity2690 secretion was stimulated by two sequential 45-min exposures to low and high @entity413 concentrations (3.3 and 16.7 mmol/l, respectively). @entity2690 concentrations were measured by radio-immunoassay, and the ratio between the @entity2690 responses to high and low @entity413 was calculated ( @entity2690 stimulation index, ISI). After 14 days of culture, some fresh islets were processed for @entity4653 ( @entity4653 ). At day 14, ISI was markedly reduced in both fresh and cryopreserved islets with respect to 1 day cultures. Cryopreservation reduced ISI at day 1 and day 14, but in the latter case only when cultures were maintained at 37 degrees C. Coculture with @entity6567 did not affect ISI of fresh islets at day 1, and enhanced it at day 14, but only at a culture temperature of 33 degrees C. Conversely, coculture raised ISI of cryopreserved islets at both day 1 and day 14, independently of the culture temperature. @entity4653 showed that at day 14 of culture, the morphology of fresh islets displayed the best preservation when cocultured with @entity6567 at 33 degrees C. Our findings confirm that both long-term culture and cryopreservation decrease viability of @entity1 pancreatic islets. Moreover, they indicate that coculture of islets with @entity6567 at 33 degrees C represents a valuable tool to improve the survival and functional activity of islets, especially in the case of cryopreserved material.

Effects of cryopreservation and coculture with pancreatic ductal epithelial cells on @entity2690 secretion from XXXX pancreatic islets.

@entity1 :: ('9606', 'Species') :: ['human'] @entity6567 :: ('CHEBI:23580', 'Chemical') :: ['DEC'] @entity2690 :: ('3630', 'Gene') :: ['Insulin', 'insulin'] @entity413 :: ('MESH:D005947', 'Chemical') :: ['glucose'] @entity4653 :: ('MESH:D004401', 'Disease') :: ['SEM', 'scanning electron microscopy']
@entity1 :: (9606,Species) :: ['human']
