中文摘要：

目的观察人诱导性多能干（induced pluripotent stem,iPS）细胞向神经干细胞（neural stem cells,NSCs）定向分化过程中相关microRNA的变化。方法结合维甲酸（RA）和无血清培养基诱导法,获得人iPS细胞分化来来源的NSCs,以未分化的iPS细胞为对照组,分别提取拟胚体（EB）培养4d,iPS细胞来源的NSCs贴壁培养14d的细胞总RNA,采用实时荧光定量PCR检测各时间点的mir-34a、mir-9、mir-200b的变化。结果 （1）与对照组相比较,mir-34a在EB 4d未见明显变化,在iPS细胞来源的NSCs培养14d时表达量升高,升高约13倍。（2）mir-9在EB4d未见明显变化,在iPS细胞来源的NSCs培养14d时表达量升高,升高约10倍。（3）mir-200b在EB 4d未见明显变化,在iPS细胞来源的NSCs培养14d时表达量升高,升高约10倍。结论在iPS细胞向神经干细胞定向分化的过程中,mir-34a、mir-9、mir-200b均明显增高,提示miR-34a、mir-9、mir-200b在iPS细胞向神经干细胞分化过程中起重要作用。

英文摘要：

Objective To explore the expression change of microRNA in differentiation of induced pluripotent stem（iPS） cells into neural stem cells.Methods The differentiated process was carried out through retinoic acid（RA） inducing procedure.Total RNA was extracted from EB cultured for 4 days,neural stem cells derived from iPS cells cultured for 14 days and the control iPS cells.The expression levels of mir-34a、mir-9 and mir-200b at different time points post differentiation were evaluated by real-time PCR.Results（1）Compared with the control,the expression of mir-34a has no significant change at EB cultured for 4 days,but 13-fold up-increased at neural stem cells derived from iPS cells cultured for 14 days.（2）The expression level of mir-9 has no significant change at EB cultured for 4 days,but 10-fold up-increased at neural stem cells derived from iPS cells cultured for 14 days.（3）The expression level of mir-200b has no significant change at EB cultured for 4 days,but 5-fold up-increased at neural stem cells derived from iPS cells cultured for 14 days.Conclusions The expression levels of mir-34a,mir-9 and mir-200b increased significantly during the process of neural stem cells derived from iPS cells,indicating a potential role of those microRNA in the process of iPS cells differentiation.