Reconstruction of cirrhotic liver by means of extracellular matrix remodeling and differential stimulation of stem cells.

本研究的目的是阐明在肝细胞生长因子（HGF） cCDNA基因治疗期间，骨髓来源的多能干细胞在肝硬化肝脏重建过程中的作用。[方法]C57BL/6J小鼠灌胃CCl_4(2.0ml/kg / o) 6周后肝硬化。在900cGy照射后，这些动物接受来自LacZ转基因小鼠的骨髓细胞移植。移植后部分受者每周1次注射hvj脂质体包裹的HGF cDNA （200μg/体），连续4周。对照组给予空hvj脂质体。在此期间，CCl_4继续每周给药一次。在这些动物中，免疫组织化学研究了lacz阳性骨髓来源细胞向肝脏的募集。同时检测c-Met/HGF受体在骨髓细胞表面的表达。[结果]HGF cDNA基因治疗能有效减轻小鼠肝硬化。在肝硬化肝脏重建过程中，大部分供体源性lacz阳性细胞分化为内皮细胞或窦状内皮细胞。小部分lacz阳性细胞也分化为Kupffer细胞，但未分化为肝细胞、卵圆细胞或肝状细胞。免疫组织化学法检测部分骨髓细胞c-Met的表达。结论：肝组织源性干细胞与骨髓源性干细胞分化相结合可有效地进行肝硬化重建。HGF可能会加速这些干细胞向肝脏构成细胞的分化。

The purpose of the present study was to clarify the role of bone marrow-derived multipotent stem cells in the reconstructing process of cirrhotic livers during gene therapy with hepatocyte growth factor(HGF) cCDNA. [Methods]C57BL/6J mice received CCl_4(2.0ml/kg p.o.) for 6 weeks, developing liver cirrhosis. After irradiation of 900cGy, these animals underwent transplantation with bone marrow cells derived from LacZ transgenic mice. After the transplantation, some of the recipients were injected with HGF cDNA encapsulated in HVJ-liposome(200μg/body i.m.) once a week for 4 weeks. Control animal received empty HVJ-liposome. CCl_4 administration was continued once a week during this period. In these animals, recruitment of LacZ-positive bone marrow-derived cells into the liver was investigated immunohistochemically. Expression of c-Met/HGF receptor on the cell surface of bone marrow cells was also examined. [Results]Gene therapy with HGF cDNA effectively attenuated liver cirrhosis in the mice. During the reconstructing process of the cirrhotic livers, most of the donor derived LacZ-positive cells differentiated into the endothelial cells or sinusoidal endothelial cells. Small part of the LacZ-positive cells also differentiated into Kupffer cells, but not into hepatocyte, oval cells, or hepatic sttelate cells. Expression of c-Met was detected immunohistochemically on some of the bone marrow cells. [Conclusion]These results suggest that reconstruction of cirrhotic liver is efficiently carried out in combination of hepatic tissue-derived and bone-marrow-derived stem cell differentiation. HGF possibly accelerates differentiation of these stem cells into liver-constituting cells.