体外培养的神经干细胞的端粒和端粒酶活性

Telomere and Telomerase Activity of Neural Stem Cells Cultured in vitro

目的了解体外培养的神经干细胞端粒酶活性，观察培养不同时间神经干细胞的端粒酶活性、端粒长度的情况。方法采用无血清培养法从新生大鼠脑皮质分离培养神经干细胞，通过免疫荧光细胞染色鉴定神经干细胞；TRAP-ELISA法测定培养4～12周的神经干细胞的端粒酶活性；Southern-blot法测定培养第1代、第10代时神经干细胞的端粒长度。结果从新生大鼠脑皮质分离培养的神经干细胞具有端粒酶活性；体外培养12周内神经干细胞的端粒酶活性未见变化；神经干细胞具有较长的端粒（23．8～24．3kb），且不随细胞传代而变化。结论大鼠脑神经干细胞具有端粒酶活性，在体外培养过程中，未见活性变化并能维持端粒的长度。

Objective To investigate the telomerase activity and telomere length of neural stem cells（NSC） in vitro of different culture time. Methods NSC were isolated from neonatal rat cerebral cortex and cultured in serum-free medium. Cells were identified by immunofluorescence staining. The telomerase activities of NSC were measured by TRAP-ELISA in 4-12 weeks. The telomere length of 1st and 10th generation of NSC was determined by southern-blot. Results NSC isolated from neonatal rat cerebral cortex express telomerase activity. No change of telomerase activity was observed within 12 weeks culture time. NSC contain telomeres that were as long as 23.8-24.3 kb and they did not change with the passage. Conclusion NSC cultured from rat brain possess telomerase activity. No different was showed in telomerase activity of NSC during cultured in vitro and maintain telomere length of NSC.