静脉移植BMSCs在急性肝损伤小鼠肝内的分布

DISTRIBUTION OF VEIN-TRANSPLANTED BONE MARROW STEM CELLS IN ACUTE-LIVER-INJURY MICE

目的研究静脉移植的骨髓间充质干细胞(BMSCs)在急性肝损伤小鼠肝组织内的分布情况。方法雌性昆明种小鼠42只,随机分为正常对照组、损伤模型组和干细胞移植组。损伤模型组和干细胞移植组小鼠均以橄榄油配制的含体积分数0.4的CCl4一次性灌胃制备急性肝损伤模型。分离同种小鼠BMSCs,体外扩增、BrdU标记后经尾静脉移植于灌胃后24h的干细胞移植组小鼠体内。分别于CCl4灌胃后的第5、10、15天取损伤模型组和干细胞移植组小鼠的肝脏,每组每个时间点取材6只,正常对照组小鼠不做处理,直接取6只小鼠肝脏,各组均制备石蜡切片和连续冷冻切片,苏木精-伊红(HE)染色观察肝组织的结构变化,免疫组织化学染色追踪BrdU阳性标记干细胞在肝组织内的迁移和分布情况。结果 HE染色结果显示,干细胞移植组小鼠在CCl4灌胃后的第5、10、15天的肝组织修复状态明显好于相同时间点的损伤模型组;干细胞移植组小鼠CCl4灌胃后的第15天肝组织接近正常。免疫组化结果显示,干细胞移植组小鼠在CCl4灌胃后第5天肝组织内散在分布着大量的黄色或褐色的BrdU阳性细胞胞核;干细胞移植组小鼠CCl4灌胃后第10天时肝组织内的BrdU阳性细胞胞核数目较第5天时少,而第15天时较第10天时明显减少,第15天与第5、10天比较,差异有显著性(t=3.350、2.907,P<0.05)。结论静脉移植的BMSCs可以迁移至急性肝损伤小鼠肝脏,并可促进损伤肝脏的修复;随着移植时间的延长单位面积内BrdU阳性细胞数量减少。

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, da mage-model group and stem cell transplantation （SCT） group. The mice in damage-model group and SCT group were given intra- gastric olive oil containing 40%0 CC14 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 15 after intragastric administration of CC14, 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 with- out any management. Paraffin sections and continuous frozen sections were prepared and hematoxylin-eosin （HE） stained. The dis- tribution of BrdU positive transplanted ceils were detected by immunohistochemistry. Results HE staining results showed on days 5,10 and 15 after intragastric CCl4, the tissue repair status of liver in SCT group was much better than that in the damage- model group, and on day 15, the liver tissue of mice in SCT group nearly reached normal standard. Immunohistochemieal 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 5 day, and much fewer was noted on day 15, the differences being significant between day 15 and both days 5 and 10 （t =3.350,2.907;P〈0.05）. 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.