同种异体骨髓间质干细胞移植在大鼠肝内定居能力初步研究

目的探索绿色荧光蛋白标记的大鼠骨髓间质干细胞（MSCs）经不同途径移植到同种异体大鼠后其定居于肝脏的能力。方法从大鼠骨髓中分离培养获取MSCs，以绿色荧光蛋白进行标记，体外扩增后，分别从大鼠尾静脉和门静脉注入同种异体正常和肝脏损伤大鼠体内，于移植后的第3、7天通过荧光定量PCR检测移植的MSCs在大鼠肝内的表达情况。结果所有大鼠移植同源异体MSCs后全部存活，无意外死亡。从门静脉、尾静脉注入MSCs，在大鼠肝脏受损时其定居量大于非肝脏受损大鼠（P〈0．05）。在肝细胞受损大鼠，从门静脉注入MSCs与从尾静脉注入比较肝脏定居量差异不显著（P〉0．05）。非肝脏受损大鼠，从门静脉注入MSCs与从尾静脉注入比较细胞定居于肝脏量差异显著（P〈0．05）．并与移植后时间有关。结论干细胞定居于肝脏的时间与细胞数量可能与肝脏是否受损伤关系密切．与移植途径关系不密切；在正常动物干细胞可定居于肝脏，定植的细胞量与移植途径和移植后时间有关。

A preliminary study of the homing capacity of allograft mesenchymal stem cells to rat liver

OBJECTIVE: To study the homing capacity of allograft mesenchymal stem cells (MSCs) transfected with a green fluorescent protein (GFP) retroviral construct to the liver of rats. METHODS: MSCs were obtained from rat bone marrow and cultured in vitro in conditional DMEM medium supplemented with 10% fetal bovine serum. The MSCs were identified by the monoclonal antibodies of CD29, CD44, CD34, CD45, CD90, SH-2 and SH-3 followed by transfection with a GFP retroviral vector. After ex vivo expansion, the transfected MSCs were infused through the tail vein or portal veins of rats, some of which were subjected to treatment with carbon tetrachloride (CCl(4)) to induce centrolobular liver necrosis. On days 3 and 7 after transplantation, the liver was removed from each recipient and evaluated for the presence of GFP transgene in purified genomic DNA using sensitive real-time PCR. RESULTS: All the rats receiving GFP-labeled MSCs survived until the study had been completed. GFP transgene in purified genomic DNA were detected in the livers of all the rats with GFP-labeled MSC infusion by sensitive real-time PCR. DNA copy numbers of GFP in the liver were higher in rats with CCl(4) treatment than in those without the treatment. Infusion of the MSCs through the tail vein or the portal vein did not produce significant difference in the mean DNA copy number in the liver of CCl(4)-treated rats. In rats without CCl(4) treatment, the sites of MSC infusion, e.g. through the tail vein or the portal vein, produced significant difference in MSC homing to the liver, which was also related to the passage of time after MSC infusion. CONCLUSION: In rats with liver injuries induced CCl(4), the timing and number of MSCs homing to the liver might be closely related to the presence of liver injury, but not to the site of MSC infusion, e.g. through the tail vein or the portal vein. MSCs possess homing capacity to the liver in normal recipient rats, and number of homed MSCs is related to the site of infusion and post-transplantation time.