黄芪多糖对衰老小鼠造血干细胞细胞周期调控蛋白的影响

目的 观察黄芪多糖对小鼠造血干细胞（HSC）细胞周期调控蛋白表达的影响,探讨黄芪多糖延缓HSC衰老的机理.方法 C57BL/6J小鼠随机分为对照组、模型组、干预组.模型组采用D-半乳糖皮下注射建立小鼠衰老模型;干预组在造模的基础上给予黄芪多糖灌胃;对照组和模型组给予等剂量NS灌胃.免疫磁珠分离纯化HSC,衰老相关的β-半乳糖苷酶（SA-β-gal）染色检测衰老细胞;流式细胞术检测细胞周期分布;Western blotting检测P16、CDK4及CyclinD表达.结果 与对照组比较,模型组HSC SA-β-gal染色阳性率、G1期比例及p16表达均明显增加;S期比例及CDK4、CyclinD表达下降.与模型组比较,干预组HSC SA-β-gal染色阳性率、G1期比例及p16表达均降低;S期比例、CDK4及CyclinD表达均增加.结论 黄芪多糖可能通过调节细胞周期相关蛋白的表达延缓小鼠HSC衰老.

Effects of astragalus polysaccharide on cell cycle regulatory protein of hematopoietic stem cell in aging mice

Objective To investigate the effects of astragalus polysaccharide on the cell cycle regulatory protein expression of hematopoietic stem cell （HSC） in aging mice and further explore the mechanisms underlying astragalus polysaccharide delaying aging. Methods C57BL/6J mice were randomly divided into the control, model and treament groups. Mice were injected with D-galaetose subcutaneously once a day for eight weeks to establish aging mice model. Mice in treatment groups were treated with astragalus polysaccharide by intragastric ad ministration, while mice in the control and model group were treated with intragastric equal -volume normal saline. Mouse HSC were isolated by magnetic cell sorting. Senescence - associatedβ - galactosidase （ SA - β- gal） staining was used to detect aging HSC. Cell cycles were detected by flow cytometry. The expressions of p16, CDK4 and cyclinD were determined by western blotting analysis. Results Compared with the control group, the ratio of SA -β - gal positive cells, the proportion of G1 stages and the expression of p16 protein were signifi- cantly increased and the expression of CDK4 and CycliuD and the proportion of S stages were decreased in the model group. Compared with the model group, astragalus polysaccharide significantly decreased the ratio of SA - β -gal positive cells, the proportion of G1 stages and the expression of p16 protein and increased the proportion of S stages and the expression of CDK4 and CyclinD. Conclusion Astragalus polysaccharide could delay HSC ag- ing and the mechanisms might be partly associated with the regulation of cell cycle - related protein expression.