RESUMEN
Biliary complications remain a major source of morbidity in liver transplant patients. Among these complications, nonanastomotic biliary strictures (NAS) are especially common and they are frequently therapy resistant in part because biliary epithelial cells are more sensitive to warm ischemic injury than hepatocytes. It has been a challenge to maintain the physiological function of biliary epithelial cells during liver transplantation. In this work, we have examined the effect of oxygen on proliferation of biliary epithelial cells in the rat livers obtained from donation after circulatory death (DCD). Twelve rat livers from DCD were divided into two groups. Livers in the control group were isolated following a standard procedure without oxygen supply. Livers in the experimental group were isolated with a constant supply of oxygen. All livers were then connected to an ex situ liver culture system in the presence of bromodeoxyuridine (BrdU), a thymidine analogue and a marker for cell proliferation. After 6 hours of normothermic ex situ liver culture, morphology and DNA replication in hepatocytes and biliary epithelial cells were assessed and compared between the two groups. We found that about 4.5% of the biliary epithelial cells in the experimental group proliferated compared with only 0.4% of cells in the control based on BrdU staining. No significant change in cell morphology was observed in those cells between the two groups. Thus, our results indicate that oxygen supply is required for maintenance of the physiological function of biliary epithelial cells during liver transplant and suggest that a constant oxygen supply during liver isolation along with ex situ liver organ culture can enhance the repair of biliary epithelial cell injury during liver transplantation.
RESUMEN
UNLABELLED: Liver transplantation is an effective approach to end-stage liver disease. Shortage of donor liver and increased waiting time for liver transplantation necessitate the development of an organ culture system by which livers can be cultured and maintained ex situ for a prolonged period of time. The aim of this work is to test whether cell culture condition in vitro could be used to culture whole livers ex situ without the use of erythrocytes. Twelve castrated male land race/farm young porcine livers were exposed to 30 min warm ischemia and 30 min cold perfusion. Livers were isolated and connected to an Ex situ liver culture system using a standard culture medium RPMI1640 supplied with 10% of fetal bovine serum and sufficient dissolved oxygen under a normothermic condition for 6 hours. Metabolic biomarkers, bile and urea production, hepatic cell viability and histology analysis of biopsies were examined and newly proliferated hepatic cells labeled by BrdU were analyzed after 6 hours ex situ culture. The results from biochemical assays and histology analysis indicate that livers after the organ culture still maintain the full function. CONCLUSIONS: Our data demonstrate that the liver culture system established in this work can be used to culture whole livers ex situ in the absence of erythrocytes.