小鼠骨髓内皮细胞条件培养液支持卵黄囊造血干/祖细胞的体外生长

目的;观察小鼠骨髓内皮细胞条件培养液（mBMEC-CM)对卵黄囊造血干／祖细胞体外生长的支持作用。方法：取妊娠第8．5天的卵黄囊,经消化后获得卵黄囊细胞,取卵黄囊非贴壁细胞加入含10％mBMEC-CM和10％FBS的DMEM中培养24h后,收集细胞做半固体培养。结果：mBMEC-CM在液体培养体系中能扩增卵黄囊造血干／祖细胞使粒－巨噬系集落形成单位（granulocyte-macrophage colony forming unit,CFU-GM)和高增殖潜能集落形成细胞（high proliferative potential-colony forming cell,HPP-CFC)的产率增加,经24h液体培养后的CFU－GM和HPP－CFC的数目分别为培养0h对照组的119．5％和130．8％（P＜0．05）;mBMEC-CM联合flt3配基（flt3 ligand,FL)和血小板生成率（,TPO)后,其扩增CFU－GM和HPP－CFC的能力明显增加,mBMEC-CM联合FL和TPO经24h液体培养后的CFU－GM和HPP－CFC的数目分别为培养0h对照组的132．0％和176．9％（P＜0．01）。结论：mBMEC-CM对卵黄囊造血干／祖细胞的维持和扩增有促进作用,mBMEC-CM联合FL和TPO对卵黄囊造血干/祖细胞的扩增作用明显增强。

Effects of murine bone marrow endothelial cell conditioned medium on the growth of yolk sac hematopoietic stem cells and progenitors

OBJECTIVE: To investigate the effects of murine bone marrow endothelial cell conditioned medium (mBMEC-CM) on the growth of yolk sac hematopoietic progenitors. METHODS: The serum-free mBMEC-CM was obtained from subcultures of murine endothelial cell line derived from bone marrow which was established in our laboratory. The murine yolk sacs were harvested on day 8.5 postcoitus (pc) and incubated with 0.1% collagenase in 10% fetal calf serum at 37 degrees C for 40 minutes. Yolk sac cells were incubated in tissue culture dishes at 37 degrees C for 1 hour. Nonadherent cells were collected for semisolid culture assay of granulocyte-macrophage colony forming unit (CFU-GM) and high proliferative potential-colony forming cell (HPP-CFC) after being cultured in DMEM with 10% mBMEC-CM and 10% FBS for 24 hours. The number of CFU-GM and HPP-CFC was counted at day 7 and day 14 respectively. RESULTS: The growth of CFU-GM and HPP-CFC was supported by mBMEC-CM with GM-CSF. mBMEC-CM could induce the proliferation and differentiation of yolk sac hematopoietic stem cells and progenitors in liquid culture system. The percentages of CFU-GM and HPP-CFC compared with the 0 hour control were (119.5 +/- 5.7)% and (130.8 +/- 9.8)% respectively after 24 hours liquid culture (P < 0.05). The expansion effects of mBMEC-CM on CFU-GM and HPP-CFC were enhanced by compounded with flt3 ligand (FL) and thrombopoietin (TPO). The percentages of CFU-GM and HPP-CFC compared with the 0 hour control were (132.0 +/- 6.2)% and (176.9 +/- 12.8)% respectively after 24 hours liquid culture (P < 0.01). CONCLUSION: Murine bone marrow endothelial cell conditioned medium could support the growth and proliferation of yolk sac hematopoitic stem cells and progenitors, and this promoting effect was further enhanced by addition of FL and TPO.