重组人Jagged 1蛋白促进细胞因子对脐血干细胞的扩增

目的 探讨重组人Jagged 1蛋白对脐血干细胞体外扩增的促进作用。 方法 利用免疫磁珠法分离人脐带血CD34+细胞，并将其分为4组，分别在 ① 不加入任何生长因素、② Jagged 1蛋白、③ TPO、SCF和Flt-3以及④ Jagged 1蛋白、TPO、SCF和Flt-3条件下进行培养；培养6 d后，通过台盼蓝染色和MTT等方法检测各组细胞的生长状况；同时采用RT-PCR方法检测干细胞表面标志物CD34的表达情况。结果 以上4组细胞在体外增殖6 d后的细胞浓度分别为0.4±0.1、1.3±0.5、5.0±0.8和10.2±1.5（x104/ml）；RT-PCR检测显示，各组细胞扩增6 d 后均有CD34表达。结论 Jagged 1蛋白能够促进细脐血干细胞的体外扩增，而且Jagged 1蛋白与其他促进细胞增殖的因子配伍对脐血干细胞在体外的扩增作用更加明显。

Recombinant human Jagged 1 protein enhances cytokine induced expansion of umbilical cord blood stem cells

Objective To investigate the effect of recombinant human Jagged 1 on the cytokine induced expansion of umbilical cord blood stem cells. Methods Umbilical cord blood CD34+ cells were isolated by MACS system, then dividied into 4 groups and cultured in the following conditions: ① without any growth factor, ② Jagged 1 protein, ③ TPO, SCF and Flt-3, ④ Jagged 1 protein, TPO, SCF and Flt-3. After 6d culture, the cell proliferation for each group was examined by Trypan blue staining and MTT method. And the expression of stem cell surface marker CD34 gene was essayed by RT-PCR. Results After cultured for 6d, cell concentraions were 0.4±0.1, 1.3±0.5, 5.0±0.8 and 10.2±1.5（x104/ml）for the four groups respectively. And the CD34 gene expression was detected both in fresh separated umbilical cord blood cells and all experimental groups. Conclusion Jagged 1 could in-vitroly enhance the expansion of umbilical cord blood stem cells. It is more effective when Jagged 1 working together with other classic growth factors.