CD226在TPO诱导胎肝Lin-细胞增殖分化过程中的表达

Expression of CD226 on TPO－induced Lin－cells during proliferation and differentiation

目的研究CD226在造血干/祖细胞上的表达分布。TPO诱导胎肝造血干/祖细胞增殖分化过程中，CD226表达的变化及可能的信号调控途径。方法采用鸡尾酒单抗阴性分离富集Lin－造血干/祖细胞，培养于含TPO的无血清培养体系中，用PD98059阻断MAPK信号转导途径，流式细胞仪双荧光分析CD226、CD34、CD41a和CD61的表达。结果CD226在Lin－CD34＋细胞和Lin－CD34－细胞上均有表达。TPO可诱导Lin－CD41a－CD226－细胞先分化为CD41a＋CD226－细胞，再进一步分化为CD41a＋CD226＋细胞，TPO也可诱导Lin－CD226＋细胞表达CD41a和CD61。在培养的早期，PD98059可抑制CD34＋CD226＋细胞的减少，在晚期则可抑制CD41a＋CD226＋细胞的增多。结论CD226与造血干/祖细胞和巨核细胞的增殖分化可能具有密切的关系。

Aim To investigate the expression of CD226 on Lin－hematopoietic stem/progenitor cells and TPO－induced Lin－cells as well as possible pathway of signal transduction for regulating expression of CD226 by TPO. Methods Lin－hematopoietic stem/progenitor cells isolated from fetal liver mononuclear cells by negative selection with human progenitor enrichment－antibodies cocktail including anti-CD2, -CD3, -CD14, -CD16, -CD19, -CD24, -CD56, -CD66b mAbs and glycophorin A mAb were incubated in serum－free IMDM supplemented with 15％of mixture of BSA, insulin, transferrin (BIT9500) and 100μg/L TPO for 18 days. In some experiments, PD98059, a MEK1 inhibitor, was added at a concentration of 20μmol/L. The expressions of CD226, CD34, CD41a and CD61 were analyzed by using flow cytometry with double－labelling technique. Results CD226 was expressed on both Lin－CD34＋cells and Lin－CD34－cells. TPO firstly induced Lin－CD41a－CD226－cells to differentiate into CD226－CD41a＋/CD61＋cells and then into CD226＋CD41a＋/CD61＋cells. TPO could also induce Lin－CD226＋cells to express CD41a/CD61. PD98095 could suppress decrease in CD34＋CD226＋cells in the early period of the Lin－cell culture and inhibit increment in CD41a＋CD226＋cells in the later period. Conclusion CD226 seems to have a close relation with proliferation and differentiation of hematopoietic stem/progenitor cells and megakaryocytic progenitor cells.