Investigation Of UMSCs Immunomodulatory To Acute Liver Failure In Mice

ObjectiveTo explore isolation，cultivation and proliferation of mice umbilical mesenchymalstem cells(UMSCs)；To prove isolated,cultured cells can be stably passage, and have astrong proliferative activility, they can create a better prerequisite for future celltransplantation. To establish acute liver failure mode with carbon tetrachloride(CCl4) andobserve the general status of the mice；To get straight the therapeutic effectiveness ofUMSCs on Acute Liver Failure，including liver function and liver pathology.To observeserum IL-4and IFN-content before and after transplantation.To detect PD-1mRNA levelchanges at different time points in liver tissue.MethodsUMSCs were isolated from C57BL/6pregnant mice umbilical cord bytrypsin-collagenase digestion. The cells were adherent to culture flask and subculture.Thecell growth curve was plotted and observe cell morphology. With carbontetrachloride(CCl4) dissolved in olive oil,dubbed the concenttaton of50%,and packetintraperitoneal injection. The mice were divided into three groups,including theexperimental group, the transplant control group and blank control group, to detect theliver function in7,14and21days. IL-4and IFN-content were determined byenzyme-linked immunosorbent assay(ELISA). Paraffin section and HE staining were takenat different time points in hepatic tissue samples.And after this,to observe liverpathological changes. Expression of PD-1mRNA in hepatic tissue samples were detectedby reverse transcription-polymerase chain reaction(RT-PCR) at different time points.Results1.UMSCs were harvested successfully from UC by trypsin-collagenasedigestion.After two weeks, cells were long spindle or flat-shaped fibroblast-like,and they arranged in bundle-intensive parallel. After several digestions and subculture,they werestill long spindle,had more unifom shape,had a strong proliferative activity.Populationdoubling time of about24hours.2.To establish acute liver failure mode successfully.3.Liver function of the transplanted group and model group mice was statistically significantdifference （P＜0.05）.4. Comparison at different time of IL-4and IFN-content aftertransplantation UMSCs in1,2,and3weeks, IL-4was an upward trend, and IFN-was andownward trend.5. UMSCs can improve inflammatory infiltration of acute liver failure inmice, and hepatic lobule structure was conducive to return to normal.6. In normal miceliver tissue,PD-1had a low expression; after model in12,24and48hours, comparedwith blank control group, the expression of PD-1was statistically significant difference（P＜0.05）. After transplantation in24and48hours, compared with blank controlgroup, the expression of PD-1was not statistically significant （P＜0.05）, comparedwith the model group, the difference was statistically significant （P＜0.05）.ConclusionsWe was successful to isolate and establish of culture system of umbilical cordmesenchymal stem cells from mice. After several subculture,they still had a strongproliferative activity. UMSCs transplantation can improve the survival rate of mice withliver falure,liver function and liver pathology. UMSCs transplantation can balance therelations of IL-4and IFN-. PD-1can be suppressed in forward immune and may play animportant role in mice of acute liver failure and early transplantation liver inflammatoryinjury on immunomodulatory effects.