小鼠骨髓内皮细胞条件培养液体外扩增胚胎及成体造血干/祖细胞的差异及其机制探讨

本研究比较小鼠骨髓内皮细胞条件培养液(mBMEC-CM)联合FL和TPO对卵黄囊和骨髓造血干／祖细胞体外生长的影响，并对其机制进行探讨。取卵黄囊和骨髓单细胞悬液，对照组中加入含10％FBS的DMEM，实验组分别加入10％mBMEC-CM，FL(5ng/ml)和TPO(2ng／ml)，10％mBMEC-CM复合FL和TPO培养24小时后进行集落培养，计数CFU-GM和HPP-CFC的集落数。应用Atlas cDNA Expression Array对卵黄囊和骨髓造血细胞表达的细胞因子受体进行检测。结果表明：mBMEC-CM能扩增卵黄囊和骨髓CFU-GM和HPP-CFC，其与FL和TPO联合后扩增能力明显增强；mBMEC-CM扩增骨髓CFU-GM和HPP-CFC的能力明显强于其扩增卵黄囊CFU-GM和HPP-CFC的能力。检测到小鼠卵黄囊及骨髓造血细胞存在差异表达的细胞因子受体；卵黄囊造血细胞表达PDGF-Rβ，PDGF-Ra和促肾上腺皮质激素释放因子受体，而在骨髓造血细胞中未检测到上述受体的表达；在骨髓造血细胞中表达的IFN-γR，GM-CSFR，多巴胺D2受体和卵泡刺激素受体则未在卵黄囊造血细胞中检测到mRNA的表达。结论：mBMEC-CM能支持卵黄囊和骨髓造血祖细胞的体外扩增，其与FL和TPO联合后扩增能力明显增强；mBMEC-CM对骨髓造血祖细胞表现出更强的扩增作用。检测到卵黄囊和骨髓造血细胞之问存在差异表达的细胞因子受体，提示mBMEC-CM对胚胎及成体造血细胞扩增中存在的差异可能与两种造血细胞存在差异表达的细胞因子受体有关。

Analysis of the Different Effects of Murine Bone Marrow Endothelial Cell Conditioned Medium on the Growth of Embryonic and Adult Hematopoietic Stem/Progenitor Cells in vitro

In the present study, the effects of murine bone marrow endothelial cell conditioned medium (mBMEC-CM) on the growth of yolk sac and bone marrow hematopoietic stem/progenitor cells (HSPC) were investigated. Nonadherent cells of yolk sac and bone marrow were collected for semisolid culture assay of CFU-GM and HPP-CFC after being cultured in DMEM with 10% FBS, 10% mBMEC-CM and/or FL (5 ng/ml), TPO (2 ng/ml) for 24 hours. The number of CFU-GM and HPP-CFC was counted by day 7 and 14 respectively. Atlas cDNA Expression Array was used for analysis of cytokine receptor expression of yolk sac and bone marrow HSPC. The results showed that mBMEC-CM could support the expansion of CFU-GM and HPP-CFC in liquid culture system. The expansion effects of mBMEC-CM were enhanced by combination with FL and TPO. mBMEC-CM was more effective on expansion of bone marrow CFU-GM and HPP-CFC than that of yolk sac CFU-GM and HPP-CFC. The differential expression of cytokine receptors were detected between yolk sac and bone marrow HSPC. PDGF-Rbeta, PDGF-Ralpha and corticotropin releasing factor receptor (CRFR) were only expressed in yolk sac hematopoietic cells while IFN-gammaR, GM-CSFR, Dopamine D2R and follicle-stimulating hormone receptor were only expressed in bone marrow hematopoietic cells. In conclusion, mBMEC-CM could support the growth and proliferation of yolk sac and bone marrow HSPC, and this effect was further enhanced by addition of FL and TPO. mBMEC-CM was more effective on expansion of bone marrow HSPC than on expansion of yolk sac HSPC. The comparative study indicated that the different expressions of cytokine receptors existed between yolk sac and bone marrow hematopoietic cells, which might lead to the difference in expansion in vitro between embryonic and adult HSPC.