两个不同骨髓干细胞亚群体外成肝潜能的比较研究

目的研究与比较骨髓造血干细胞(hematopoieticstemcells,HSCs)和间充质干细胞(mesen-chymalstemcells,MSCs)肝分化潜能。方法常规法分离培养大鼠骨髓MSCs。以Thy-1.1为标志,免疫磁珠法(magenicactivatedcellsorting,MACS)分离纯化HSCs。探寻MSCs、HSCs的诱导条件,从形态学、RT-PCR和免疫细胞化学法鉴定肝分化结果。结果MACS分选后Thy-1.1 细胞纯度94.20%,细胞活力99.62%。纤维状MSCs诱导后呈圆形,表达白蛋白及其mRNA,不表达甲胎球蛋白。诱导的HSCs为多角形,白蛋白表达逐渐减少,甲胎球蛋白表达逐渐增强。结论MACS方法能有效分选大鼠骨髓Thy-1.1 干细胞群。MSCs和HSCs二者具有不同的肝系分化潜能。MSCs在HGF/FGF-4的作用下表达成熟肝细胞的特异性基因,分化为成熟肝细胞样细胞;HSCs在HGF/FGF-1/FGF-2的作用下表达早期肝特异性基因,分化为肝干细胞样细胞。

Comparative Study of in vitro Hepatic Differentiation Capability of Two Different Stem Cell Subsets Derived from Bone-marrow

Objects To investigate the different effects of mesenchymal stem cells(MSCs)and hematopoietic stem cells(HSCs)on hepatic differentiation.Methods MSCs from rat bone marrow were isolated and cultured by standard methods.Using Thy-1.1 as the marker of rat HSCs,Thy-1.1 cells were isolated and purified by magnetic activated cell sorting(MACS).The optimal condition of isolation,cultivation and induction of MSCs and HSCs were investigated.Morphology,RT-PCR and immunocytochemistry were used to identify the hepatic differentiation grade.Results The purity and viability of Thy-1.1 cells were 94.20 %,99.62 % after MACS.MSCs exhibited round shape after differentiation,instead of fibroblast-like morphology before differentiation.Albumin mRNA and protein were expressed positively in MSCs,and no alpha-fetoprotein(AFP)was found.HSCs were polygonal in shape after differentiation.The expression of albumin signal decreased and AFP signal increased.Conclusions Highly purified Thy-1.1 cells can be obtained from rat bone marrow by using MACS,and the viability of the cells was not impaired.Both MSCs and HSCs have hepatic differentiation capabilities.However,their capabilities were not the same.MSCs can differentiate into mature hepatocyte-like cells,and do not express early hepatic specific genes,while Thy-1.1 cells were inclined to differentiate into hepatic stem cell-like cells,with an increased AFP expression and a decreased albumin signal.