ADSC源性神经干细胞向神经元和星形胶质细胞不同方向分化时的超微结构变化研究

摘要

目的:观察成人脂肪基质细胞(ADSC)源性神经干细胞在体外向神经元和星形胶质细胞分化过程中的细胞超微结构变化.方法:体外培养、扩增ADSC,分别采用β-巯基乙醇和以3-异丁基-1-甲基黄嘌呤(IBMX)为主要成分的诱导剂对ADSC进行诱导分化.应用免疫荧光化学染色法对2种诱导剂诱导后的细胞进行神经巢蛋白(nestin)的鉴定及诱导率分析,透射电子显微镜观察不同方法诱导出的神经干细胞的超微结构特征.结果:体外培养的成人ADSC在β-巯基乙醇的诱导作用下3 h nestin的表达达高峰,以IBMX为主要成分的诱导剂诱导的细胞14 d达高峰,且前者的峰值(86%)显著高于后者(23%),但以IBMX为主要成分的诱导剂诱导的细胞nestin表达持续时间明显长于β-巯基乙醇组.透射电镜下观察不同诱导剂诱导的神经干细胞超微结构,发现细胞的大体形态相似,但细胞器有差异.结论:β-巯基乙醇或以IBMX为主要成分的不同诱导剂在使成人ADSC向星形胶质细胞或神经元等不同方向分化时,可使ADSC源性神经干细胞胞浆中细胞器发生不同的超微结构变化,而细胞核的超微结构变化不明显.%AIM: To observe the ultrastructural characteristics of neural stem cells derived from adipose - derived stromal cells ( ADSC ) differentiating into neurons and astrocytes.METHODS: ADSC were cultured, amplified and induced with β - mercaptoethanol or 3 - isobutyl - 1 - methylxanthine ( IBMX ).The expression of nestin in the induced cells was determined by the method of immunofluorescence.The ultrastructure of the induced neural stem cells was observed under transmission electron microscope.RESULTS: The expression of nestin reached the peak at 3 h in β - mercaptoethanol group and at 14 d in IBMX group, and the positive rate of the former ( 86％ ) was significantly higher than that of the latter (23％ ).However, the duration of the induction in IBMX group was obviously longer than that in β - mercaptoethanol group.The ultrastructure of the induced neural stem cells in the two groups was similar under the transmission electron microscope, only with some differences in organelles.CONCLUSION: In the process of ADSC differentiating into astrocytes or neurons with the induction of β - mercaptoethanol or IBMX, the different changes of ultrastructure in ADSC -derived neural stem cells occur in some organelles in cytoplasm, not in nucleus.