间充质干细胞体外调控骨髓造血前体细胞向单核系分化

研究间充质干细胞(MSC)能否在体外调控造血。体外分离培养人骨髓来源的MSC，RT-PCR检测其造血生长因子的表达，并以其为饲养层细胞，接种骨髓单个核细胞(MNC)，观察生长情况，并通过形态学观察和流式细胞术分析，鉴定细胞来源和分化方向。结果显示，MSC构成性表达SCF、Flt3L和M-CSF，不表达C-CSF和GM-CSF，在骨髓MNC和MSC共培养体系中，大约2周左右可以看到大量的圆形细胞粘附在梭型MSC上生长，细胞胞体为圆形，胞浆较丰富，胞核为圆形、半月型或肾型，部分细胞呈典型的单核细胞形态，流式细胞术分析该类细胞表达CDl4，不表达CDl5、CD41、glycophorin A、CD5和CDl9。表明不需要添加外源性造血生长因子，间充质干细胞能在体外调控骨髓造血前体细胞向单核系分化，其定向分化可能与MSC分泌造血生长因子及MSC与造血细胞间相互作用有关。

Monocytic differentiation of bone marrow-derived hematopoietic precursors controlled by mesenchymal stem cell in absence of exogenous hematopoitic growth factors]

To study the hematopoiesis controlled by mesenchymal stem cell (MSC) in the absence of exogenous hematopoietic growth factors in vitro. MSCs were isolated and cultured in vitro, and the hematopoietic growth factors secreted by MSCs were detected with RT-PCR. Mononuclear cells from bone marrow were seeded in 6-well plates in which MSCs had been seeded as feeder cells. After culture for 3 weeks, cells in coculture were observed with wright's staining, immunocytochemisty and flow cytometry analysis to identify the lineage of hematopoietic cells. The results showed that SCF, Flt3 Ligand and M-CSF were detected in MSCs, but G-CSF and GM-CSF were not detected. In the coculture system, a number of round shape cells grew adherently to the spindle shape MSCs after coculture for 2 weeks. Wright's staining displayed that the round shape cells had abundant plasma and kidney-shaped or oval nucleus, some cells had typical monocytic morphology, and Flow cytometry analysis displayed that the CD45+ round shape cells were positive for CD14 and were negative for CD15, CD7, CD19, CD41 and glycoporin A. Our data suggested that hematopoietic precursors from bone marrow were able to differentiate into monocyte controlled by mesenchymal stem cells in vitro in absence of exogenous hematopoitic growth factors, the committed differentiation might be regulated by the hematopoietic growth factors secreted by MSCs, and the cell-cell contact might also contribute to the differentiation.