bFGF改善脐血CD34^+细胞移植效率的实验研究

The Effect of Basic Fibroblast Growth Factor (bFGF) on the Grafting Ability of CD34^+Cord Blood Cells

目的 探讨碱性成纤维细胞生长因子 (bFGF)改善脐血CD34 + 细胞植入经大剂量化疗预处理的成人骨髓基质细胞 (hBMSC)的能力 (移植效率 )及其作用机制。方法 采用hBMSC体外长期培养 ,光镜和电镜及流式细胞术等技术 ,观察 5 氟尿嘧啶 (5 FU)对hBMSC的损伤及损伤后加入bFGF对hBMSC动力学的影响 ,以及bFGF改善脐血CD34 + 细胞对受损hBMSC的粘附能力。结果 5 FU作用hBMSC 3h后 ,细胞形态及DNA周期时相发生显著改变 ,电镜表现为细胞核裂解 ,伪足形态改变 ,流式细胞仪显示基质细胞G0 /G1期前出现明显的亚二倍体峰 ,G0 /G1期和G2 /M期显著低于正常对照组 (P <0 0 5 ) ,而S期则明显高于正常对照组。 (P <0 0 5 )植入脐血CD34 + 细胞 2h后 ,加入bFGF的干预组与损伤组比 ,脐血CD34 + 细胞在基质细胞粘附层的比例有明显提高 ,分别为 12 %和 2 9% ,但仍未达到正常对照组的比例 (36 % )。结论 5 FU可使体外培养的hBMSC形态和DNA合成受损 ;bFGF在短期内具有对受损hBMSC的修复和明显改善人脐血CD34 +

Objective To investigate the effect of bFGF on the grafting ability (grafing efficiency)of CD34 + cord blood cells seeded in 5 FU injured human bone marrow stromal cells.Methods Using combined methods of bone marrow stromal cell culture system,light microscopy and electron microscopy,flow cytometry,we investigated the toxic effects of 5 FU on human bone marrow stromal cells (hBMSC) and the benefit of bFGF on dynamics of hBMSC as well as the ability of the cord blood stem cell to bind hBMSC.Results After 3 hours incubation with 5 FU,significant changes in hBMSC cytosolic and nuclear morphology were observed.Nuclear splitting and abnormal shapes of the pseudopodia were found under the electron microscope.Flow cytometry revealed that apoptosis appeared before G 0/G 1,and that cells in G 0/G 1and G 2/M phases were remarkably lower,while the cells in S phase were remarkably higher than the controls.Two hours after adding the cord blood hematopoietic progenitor cells,the group treated with bFGF(injury with intervention of bFGF group,IBG)showed higher proprtion of the adherence layer compared to the group without adding bFGF(injury group,IG)(29% versus 12%) Conclusion 5 FU causes DNA damage in hBMSC.It also impairs the binding ability of cord blood stem cell to hBMSC.bFGF is able to repair hBMSC damage and improve the binding of CD34 + cord blood hematopoietic progenitor cells onto hBMSC.