Establishment of a mouse model of DMN-induced hepatic fibrosis after bone marrow transplantation

Objective To establish a model of hepatic fibrosis in mice labeling bone marrow cells with green fluo-rescent protein(GFP).Methods Thirty-two ICR mice were randomly divided into normal group and transplantation group.The mice in the transplantation group were lethally irradiated and received bone marrow transplants from GFP trans-genic ICR mice.The normal group was not irradiated and transplanted.Blood smear was prepared and examined after two months.The hematopoietic reconstitution animals were further divided into control and model subgroups.The mice in the model group were injected intraperitoneally with dimethylnitrosamine(DMN) in a dose of 10 mg /kg every other day.The normal group and the control group received only normal saline.All groups were observed at 3 w and 4 w after DMN intoxi-cation.The levels of ALT,AST,Alb and T.Bil were examined by commercial kits,respectively.The contents of hepatic hydroxyproline were measured by Jamall’s method.Liver inflammation and collagen deposition were evaluated by histologi-cal examination with HE and Sirius red staining,respectively.Homing of bone marrow-derived cells was detected by GFP immunofluorescence staining.Results Two months after transplantation,GFP + cells appeared in the peripheral blood of transplanted mice.A significant hepatic fibrosis could be found after DMN intoxication for 4 weeks.With the aggravation of liver fibrosis,the number of GFP + cells homing to the liver was gradually increased.Conclusions Intraperitoneal injection of DMN every other day in a dose of 10 mg /kg for 4 weeks can induce a significant liver fibrosis.Bone marrow transplantation may reconstruct the hematopoietic system in irradiated animals without significant liver damage.With the progress of liver fibrosis,there are bone marrow-derived cells homing to the liver tissue.The establishment of this model pro-vides a technical platform for the study of bone marrowderived stem cells homing and differentiation in the process of hepat-ic fibrosis,as well as drug intervention for their homing and differentiation.