Investigation In Differentiation Of Human Umbilical Cord Mesenchymal Stem Cells Into Hepatocytes In Partially Hepatectomized Rats In Vivo

ObjectivesTo evaluate the effects of human umbilical cord mesenchymal stem cell transplantationand the potential of differentiation into hepatocytes in liver partially hepatectomized rat model,and to provide more preclinical evidences for MSCs's clinical application.MethodsStem cells were isolated from human umbilical cord by digestion of collagenase.The cellswere cultured and the surface markers were determined by flow cytometry. At passage5Mesenchymal stem cells(MSCs),the human umbilical cord MSCs were labeled by PKH26.Dividing72SD rats into three groups at random: the test group,the model group and the controlgroup,24rats in each group. The rats were anesthetized with pentobarbital. The test group wereremoved the hepatic lobe of diaphragmatic leaves and injected the cell suspension labeled byPKH26into the portal vein. The model group were removed the same proportion of hepatic lobeand injected the same volume saline into portal vein. The control group were injected the samevolume saline into portal vein. All rats were injected with saline (30ml/kg) subcutaneously forthe body liquid loss.Six rats from each group were sacrificed at3d,9d,15d,21d post-operation.The liver specimens were made to evaluate the effects of human umbilical cordmesenchymal stem cell transplantation, the potential of differentiation into hepatocytesin liver partially hepatectomized rat model and the expression of hepatocyte marker albumin.The indexes were tested as follows:1.the activity of alanine transaminase and aspartateaminotransferaseï¼›2. serum total bile acid and albuminï¼›3. the liver indexï¼›4. making liverpathological sections and scoring their pathological severity. ResultsThe human umbilical cord MSCs could be cultured in vitro.After they were transplanted tothe partially hepatectomized rat's liver, they could survive and express the hepatic makeralbumin in vivo.When they were labeled by PKH26, they show the red fluorescence under thefluorescence microscope.In the frozon sections of liver,the marked cells were scattered and mostof them expressed albumin with green fluorescence under the fluorescence microscope.Therelevant indicators of control group had no obvious changes.Compared with the control group,the indicators of test and model group had statistics significance (p<0.05). When they werecompared with each other at many time points, the relevant indicators in the test and modelgroup had statistics significance (p<0.05).ALT,AST indicators in test group were significantlylower than the model group at9d; TBA indicators in test group were significantly lower than themodel group at21d; ALB indicators were significantly higher than the model group at15d.Conclusion1. The human umbilical cord MSCs could be successfully isolated and cultured in vitro,and had a strong potential of proliferation,differentiation.2.It revealed that the transplanted human umbilical cord MSCs could survive anddifferentiate into hepatocytes in the experiment, which shows that the human umbilical cordMSCs may become a main source of hepatocyte transplantation in future.