Distribution of vein-transplanted bone marrow stem cells in acute-liver-injury mice

Objective To investigate the distribution of vein-transplanted bone marrow stem cells(BMSCs)in liver of mice after acute liver injury. Methods Forty-two female Kunming mice were evenly randomized to normal control group,damage-model group and stem cell transplantation(SCT)group.The mice in damage-model group and SCT group were given intragastric olive oil containing 40% CCl4 to create a model of acute liver injury.BMSCs of the isogeneic mice were isolated,proliferated in vitro,and labelled with 5-bromo-2-deoxyuridine(BrdU)and then transplanted to the mice in SCT group,through caudal vein,24 hours after lavage.On days 5,10 and 15after intragastric administration of CCl4,the livers of six mice in damage-model group and SCT group were taken,respectively,in each time.The livers in the six mice of normal control group were taken directly without any management.Paraffin sections and continuous frozen sections were prepared and hematoxylin-eosin(HE)stained.The distribution of BrdU positive transplanted cells were detected by immunohistochemistry. Results HE staining results showed on days 5,10 and 15after intragastric CCl4,the tissue repair status of liver in SCT group was much better than that in the damagemodel group,and on day 15,the liver tissue of mice in SCT group nearly reached normal standard.Immunohistochemical results showed a large number of yellow or brown BrdU positive nuclei diffusely distributed in liver tissue of mice,on day five after CCl4 lavage,in SCT group,and on day 10,the number of BrdU-positive cells was fewer than that on the day 5day,and much fewer was noted on day 15,the differences being significant between day 15 and both days 5and 10(t=3.350,2.907;P0.05). Conclusion Vein-transplanted bone marrow stem cells can migrate to acutely injured liver of mice and promote repair of injured liver,the number of BrdU-positive cells per unit area decreases with the extension of transplantation time.