增殖细胞核抗原在脐血CD34^+造血干/祖细胞中的表达及意义

Expression of proliferating cell nuclear antigen in cord blood CD34^+ hematopoietic stem/progentior cells

目的 探讨增殖细胞核抗原 (PCNA)在脐血造血干 /祖细胞中的表达及意义。方法 采用流式细胞仪技术对不同培养时间和不同培养条件下脐血CD34+ 细胞中PCNA的表达水平和细胞周期进行了测定。结果 新鲜分离的脐血中CD34+ 细胞低表达PCNA ,阳性率为 (11 6± 5 2 ) % ,在体外短期培养 ,无细胞因子的组合PCNA表达逐渐下降 ,而在含有各细胞因子组合的培养体系中 ,PCNA表达水平明显增高 ,其中以SCF ,IL - 3,IL - 6 ,FL ,Tpo组合作用最显著 ,在培养第 7天时 ,PCNA蛋白表达率为 (78 2± 8 7) % ,且S/G2 /M期的细胞占 (5 9 8± 6 7) % ,明显高于培养前。结论 脐血CD34+ 细胞低水平表达PCNA ,造血生长因子对CD34+ 细胞的促增殖作用与上调PCNA蛋白的表达有关。

Objective To investigate the expression and significance of protein in cord blood(CB) hematopoietic stem/progentior cells. Methods Using flow cytometry, PCNA and cell cycle in CB CD34 + cells were measured in different conditions and different culture time. Results Low level of PCNA protein was expressed in freshly isolated CB CD34 + cells, with a positive rate of(11.6±5.2)%. In vitro culture, PCNA protein gradually decreased without growth factors, but significantly increased in the presense of vaious growth factors, especially with the combination of SCF, IL-3,IL-6, FL and Tpo. After 7 days of culture, its protein level reached(78.2±8.7)%, and the number of S/G 2/M phase cells significantly increase. Conclusion Low level of PCNA protein is expressed in freshly isolated CB CD34 + cells. Growth factor stimulates the proliferation of CD34 + cells by up-regulating the expression of PCNA.