间充质干细胞向肝细胞分化研究

目的探讨间充质干细胞在体外诱导分化为肝细胞后,细胞增殖能力和免疫抑制能力等干细胞生物学的改变。方法间充质干细胞在体外进行向肝细胞诱导分化培养,分化为具有部分成熟肝细胞功能的肝细胞样细胞,并对这些肝细胞样细胞继续培养。流式细胞仪检测细胞表型,BrdU法检测细胞增殖能力,与CD4＋T淋巴细胞共孵育实验检测细胞免疫抑制实验。结果间充质干细胞分化为肝细胞后,虽然具备了部分成熟肝细胞的功能,亦丧失了间充质干细胞本身的一些特性;BrdU法测增值能力,其OD值从1.859±0.117降到1.24±0.103,抑制CD4＋T细胞激活的能力从94.8%（100%-5.2%）降到68.8%（100%-31.2%）等;而且分化后的细胞处于不稳定的分化状态,继续培养后,其细胞生物学相关特性和功能均出现去分化的现象,比如增殖能力恢复到OD值为1.501±0.229,免疫抑制能力恢复到81.8%（100%-18.2%）。这种不稳定的状态,进入体内后,是否会增加突变或致癌的概率,仍需进一步的研究。结论间充质干细胞比其向肝细胞诱导分化后的细胞更具安全性,更适合肝病治疗。

In vitro study of hepatic differentiation of mesenchymal stem cells

Objective To study the changes of cellular biological properties of mesenchymal stem cells after hepatic differentiation.Methods Mesenchymal stem cells（MSC） were induced into hepatocytelike cells（HLC） which possessed partial functions of hepatocytes.Both MSC and HLC phenotypes were detected by flow cytometer.Cell proliferative potential was detected by BudU.Immunosuppressive ability of these cells was also compared by co-culture with CD4＋T cells.Results When MSC were differentiated into HLC,these MSC-derived-HLC lost several major properties in comparison with undifferentiated MSC.The proliferative potential（OD value detected by BrdU） was decreased from 1.859 ±0.117 to 1.24 ±0.103,and the rate of inhibition of impaired immunosuppression from 94.8%to 68.8%.Furthermore,HLC is not in a steady mature stage.When HLC continued to be cultured,its proliferative potential and immunosuppression were partially recovered.For example,OD value of D-HLC was 1.501 ±0.229;the rate of inhibition was 81.8%.Conclusion The possibility of the formation of teratomas after HLC transplant still needs to be further investigated.Based on our data,undifferentiated MSC may be more safety and appropriate than HLC for me treatment of liver diseases.