促血小板生成素对骨髓c-Kit^+Lin^-细胞体外扩增的影响

Effects of thrombopoietin on the in vitro expansion of c-Kit^+Lin^-cells from bone marrow

目的探讨在无血清条件下,血小板生成素(TPO)对c-Kit+Lin-细胞增殖的影响。方法经免疫磁珠分离小鼠骨髓c-Kit+Lin-细胞,研究在干细胞因子(SCF)、FLt-3配基(FL)和白血病抑制因子(LIF)组合中添加不同浓度的TPO,7 d后检测细胞总数,c-Kit+Lin-细胞扩增倍数,并采用Annexin-V检测各组细胞凋亡率。结果各组均能显著扩增c-Kit+Lin-细胞,扩增倍数为4~7倍不等。当SCF+FL+LIF中加入50μg/L TPO时,c-Kit+Lin-细胞及细胞总数扩增为7.07倍和40.19倍,比未加时明显增多,而凋亡率无明显差异。但随剂量加大,c-Kit+Lin-细胞扩增下降,细胞凋亡率上升,200μg/L TPO组凋亡率为33.49%,c-Kit+Lin-细胞扩增倍数仅为4.11倍。结论TPO可协同SCF+FL+LIF使c-Kit+Lin-细胞增殖,但过高剂量会诱导其分化和凋亡,以50μg/L浓度扩增效果最佳。

Objective To elucidate the effect of thrombopoietin （TPO） in vitro expansion of c-Kit ^＋ Lin^ - cells from bone marrow. Methods c-Kit ^＋ Lin^ -cells were isolated by high-gradient magnetic cell sorting system （MACS） and then expanded with combinations of stem cell factor（ SCF）, FLt-3 ligand （ FL）, leukemia inhibitor factor（LIF） and different concentration of thrombopoietin （TPO） for 7days. Totall cells and Annexin-V positive ceils were examined by fluorescence-activated cell sorter （FACS）. Results Each group expanded c-Kit ^＋ Lin^ -cells effectively and rapidly, and the number of cells expanded were 4 - 7 times as compared with initiative one. Adding 50 μg/L TPO into SCF ＋ FL ＋ LIF increased expasions of c-Kit ^＋ Lin^ - and total cells by 7.07 and 40. 19 times. When the concentration of TPO increased, the c-Kit ^＋ Lin^ -cells decreased, and the apoptosis rate rised. Conclusion The results showed TPO synergistic actions with SCF ＋ FL ＋ LIF to expand c-Kit ^＋ Lin^ - cells but too much TPO may induce its differentiation and apoptosis. The best concentration to expand c-Kit ^＋ Lin^ - cells is 50 μg/L TOP.