近年来,在细胞治疗和再生医学领域,自体或异体细胞移植治疗疾病正在成为现实.骨髓间充质干细胞具有分化成多种细胞的潜能,已被广泛用于各种疾病的研究和治疗.活体追踪移植细胞,检测移植细胞的生存及功能状态对于评价移植治疗效果至关重要.目前,利用磁共振对比剂超顺磁性氧化铁颗粒(SPIO),活体追踪和监测标记细胞已被广泛用于动物实验研究和一些临床疾病诊断.但MRI信号不能显示移植细胞在体内的生物学特征.本研究中,对食蟹猴骨髓间充质干细胞体外标记Molday ION rhodamine-B^(TM)(MIRB),探讨MIRB标记后cMSCs的细胞生物学特性,以及脑内移植后的活体MRI影像学及组织学追踪.结果表明,MIRB具有生物组织相容性,能高效标记cMSCs,可用于体内多模式追踪移植细胞,为利用MIRB追踪和检测移植细胞,以及干细胞移植治疗机制的研究提供资料.
Glial cell derived neurotrophic factor （GDNF） holds promises for treating neurodegenerative diseases such as Parkinson＇s dis- ease. Human neural stem cells （hNSCs） have proved to be a suitable cell delivery vehicle for the safe and efficient introduction of GDNF into the brain. In this study, we used hNSCs-infected with a lentivirus encoding GDNF and the hygromycin re- sistance gene as such vehicles. A modified tetracycline operator 7 （tetO7） was inserted into a region upstream of the EFI-α promoter to drive GDNF expression. After hygromycin selection, hNSCs were infected with a lentivirus encoding a KRAB-tetracycline repressor fusion protein （TTS）. TTS bound to tetO7 and suppressed the expression of GDNF in hNSCs. Upon administration of doxycycline （Dox） the TTS-tetO7 complex separated and the expression of GDNF resumed. The hNSCs infected with GDNF expressed the neural stem cell specific markers, nestin and sox2, and exhibited no significant change in proliferation rate. However, the rate of apoptosis in hNSCs expressing GDNF was lower compared with normal NSCs in response to actinomycin treatment. Furthermore, a higher percentage of Tuj-I positive cells were obtained from GDNF-producing NSCs under conditions that induced differentiation compared to control NSCs. The inducible expression of GDNF in hNSCs may provide a system for the controllable delivery of GDNF in patients with neurodegenerative diseases.
WANG ShuYanREN PingGUAN YunQianZOU ChunLinFU LinLinZHANG Yu
