Abstract: To observe the therapeutic effect of transplantation of mesenchymal stem cells(MSCs) on acute liver failure(ALF) in mice,and to provide a theoretical basis for further clinical application of MSCs.Methods The MSCs of mice were isolated,cultivated,pu
rified and identified in vitro.The model of ALF induced by  CCl4 was established.The ALF  mice were randomly divided into control and treatment groups.The MSCs were transplanted into tail veins of mice in treament group,and saline was transfused into the tail veins of mice in control group.The levels of serum ALT,AST and TBIL were determined.The pathological changes of liver tissues were observed by microscope after stained with HE.The survival rate was defined as the percentage of surviving animals at any specific time points.Results The cultured MSCs at G0-G1 stage accounted for 75.27% detected by flow cytometry.The expression of CD44 in MSCs was positive(88.71%),while the expression of CD34 was negative.After the MSCs were transplanted to ALF model rats,the survival rate in treatment group(65%) was higher than that in control group(25%).The levels of serum ALT,AST and TBIL were decreased after transplantation of MSCs compared with control group(P<0.01).The degrees of  liver cell necrosis and inflammatory cell infiltration in treatment group were lighter than those  in control group on day 1 and 2.And the pathological improvement  of liver in treatment group was more evident than that in control group on day 7.The expression level of ALB in treatment group was higher than that in control group on day 7  detected by immunohistochemistry.Conclusion Transplantation of MSCs can improve liver function and increase survival rates obviously of mice with ALF,which indicates that transplantation of MSCs has an obviously therapeutic effect on ALF in mice

Key words: mesenchymal stem cells, transplantation, acute liver failure