Role Of Human Umbilical Mescenchymal Stem Cells In The Treatment Of Hepatotoxicity In HLH-like Mouse Model: Effects And Possible Meschanisms

PART I THE IMPROVEMENT OF HPS-LIKE MOUSE MODEL WITH CPG-ODN1826 AND IFN-gObjective: To improve the HPS-like mouse model with CPG-ODN1826 and IFN-g,and provide a more steady model for further therapy study.Methods: Wild type adult C57BL/6 mice were assigned to experimental group(CPG group)and control group(CON group)according to completely randomized design.HPS-like mouse model was induced by CPG oligodeoxynucleotide(CPG-ODN 1826) and interferon(IFN)- γ. All animal blood samples and tissues were collected to evaluate by the diagnosis of HPS.Results: Compared with PBS group, the mouse in CPG group were showed obviously poor general status than that in PBS group,including liver weight/ body weight(P<0.05), spleen weight/ body weight(P<0.05) were elevated;Pancytopenia(WBC,RBC,PLT,HGB,P<0.05);Serologic features: ALT,AST,LDH,TG increased significantly(P<0.05),ALB,Fbg decreased significantly(P<0.05);significant elevation of serum ferritin;The cytokine of IL-6,IL-10,IFN-g were increased significantly;Histologic features: liver sections revealed prominent periportal infiltrates;splenic architecture was altered and a large number of small nucleated cells were infiltrated in red pulp;bone marrow sections displayed severe hypoplasia;Hemophagocytosis was oberserved in liver,spleen,bone marrow.Conclusion: These data demonstrate that repeated administration of CPG-ODN1826 and IFN-g could induce HPS-like symptoms in C57BL/6 mice and IFN-g can make mouse model more steadly for further therapy study.PART Ⅱ THERAPEUTIC ROLE AND POSSIBLE MESCHANISMS OF HUMAN UMBILICAL MESCENCHYMAL STEM CELLS IN THE TREATMENT OF HEPATOTOXICITY IN HLH-LIKE MOUSE MODELObjective: The aim of this study is to assess the therapeutic effects and investigate the possible mechanism of human umbilical cord mesenchymal stem cells(h UC-MSCs) when applied in the treatment to hepatal injury in HLH-like mouse model.Methods: h UC-MSCs were labelled in vitro. Mice were assigned to the model injury group(PBS group),cell transplantation group(MSC group) and blank control group(CON group) according to completely randomized design.The HLH-like mouse model was induced by CPG oligodeoxynucleotide(CPG-ODN 1826) and interferon(IFN)- γ. Then the h UC-MSCs labelled by CM-Dil were transplanted into the mouse in MSC group via caudal vein. The general status of all mice was observed. All animal blood samples were collected to observe the serum activities of ALT,AST,LDH,ALB,TG.All liver tissue was obtained to observe liver weight and the pathohistologic changes by hematoxylin-eosin staining at day1, day3 and day7. The number of activated macrophages was observed by immunohistochemical staining of F4/80. The localization of h UC-MSCs was observed with fluorescent microscopy and cells positive for anti-human albumin antibody were observed using immunofluorescence.Results: The mice in MSC group showed generally better status than that those in PBS group, including the restore of multifocal hepatocytes necrosis and lymphocytes infiltrated in liver, liver weight/ body weight(P<0.05),the ALT,AST,TG activity(P<0.05),the peripheral blood of WBC,PLT,RBC,PLT(P<0.05) and the number of activated macrophages(P<0.05), but no changes of ALB(P>0.05),the number of activated macrophages(P<0.05). The h UC-MSCs labelled by CM-Dil were found in liver tissue of the mice in MSC group after transplatation and cells positive for anti-human albumin antibody were not found with fluorescent microscopy.Conclusions: These data indicated that h UC-MSCs can be implanted into the damaged liver tissue through caudal vein transplatation, and these cells improve liver function and repair injured liver tissue, while the realization of these recovery effects was not through the MSCs-derived hepatocyte-like cells.