间充质干细胞和内皮祖细胞对脐血造血干/祖细胞体外扩增效力的影响

目的比较脐带来源的间充质干细胞(Mesenchymal stem cells,MSCs)和内皮祖细胞(Endothelial progeni-tor cells,EPCs)对脐血造血干/祖细胞(Hematopoietic stem/progenitor cells,HSCs/HPCs)的体外扩增效力。方法正常人脐血中分离单个核细胞(Mononuclear cells,MNCs),流式细胞术检测其中HSCs/HPCs所占比例,将MNCs分别接种于处理后的MSCs或EPCs或仅接种于培养液中,比较不同培养条件对HSCs/HPCs扩增能力、表面抗原CD34的表达以及集落形成能力的影响。结果共培养过程中,MSC组和EPC组的MNCs扩增倍数均明显高于对照组,且EPC组更为显著。扩增7天后,对照组、MSC组和EPC组的HSCs/HPCs CD34的表达均较扩增前下降,其中EPC组下降的最为显著,MSC组最不显著。共培养4天后,MSC组的HSCs/HPCs集落形成总数为EPC组的2.47倍(**,P<0.01),共培养7天后,MSC组的HSCs/HPCs集落形成总数为EPC组的3.45倍(**,P<0.01);EPC组与对照组的HSCs/HPCs集落形成总数无显著性差异。结论 MSC和EPC均可为HSCs/HPCs的体外扩增提供适宜的微环境,MSC可抑制HSCs/HPCs的分化,有助于维持其表面抗原CD34的表达,并保持其造血重建潜能和归巢能力;而EPC则可有效促进HSCs/HPCs的分化。

Comparison of amplification effect in vitro between hematopoietic stem/progenitor cells co-cultured with mesenchymal stem cells and with endothelial progenitor cells

Objective Compare the amplification effect in vitro between hematopoietic stem / progenitor cells co-cultured with mesenchymal stem cells and with endothelial progenitor cells.Methods Isolate mononuclear cells（MNCs） from normal human umbilical cord blood,and analyze the proportion of HSCs/HPCs by flow cytometry.Then place the same number of MNCs on the MSCs and EPCs which were dealt with Mitomycin C respectively,or only on the culture medium,in order to compare the amplification ability,expression of CD34,and colony forming ability of HSCs/HPCs under different culture conditions.Results After co-culturing,the expansion folders of MNCs cultured with MSCs or EPCs are more than MNCs only in the culture medium obviously,especially MNCs on the EPCs.In addition,the expression of CD34 on the HSCs/HPCs in three groups all declines after 7 days expansion,especially the EPC group.On the contrary,the declining extent of MSC group is the least obviously.The total number of colony forming of HSCs/HPCs in MSC group which are co-cultured for 4 days is 2.47-folds than that in EPC group（＊ ＊,P0.01）,and the same item of HSCs/HPCs in MSC group which are co-cultured for 7 days is 3.45-folds than that in EPC group（＊ ＊,P0.01）.And there is no difference on the colony forming number between control group and EPC group significantly.Conclusion Both of the MSC and EPC layer can improve the expansion of HSC/HPCs in vitro while MSC layer can inhibit their differentiation,maintain the expression of CD34,retain their hematopoietic reconstitution and homing ability.But EPC layer can accelerate the differentiation of HSCs/HPCs effectively.