Chang Mi-Yoon, Park Chang-Hwan, Lee So-Young, Lee Sang-Hun
Department of Biochemistry, College of Medicine, Hanyang University, Seoul 133-791, South Korea.
Brain Res Dev Brain Res. 2004 Oct 15;153(1):89-96. doi: 10.1016/j.devbrainres.2004.08.003.
In vitro cultures of neural precursor cells are useful experimental tools for studies on the mechanisms of brain development, as well as for generating renewable sources in cell therapy for neurodegenerative disorders. The systematic characterization of cultured neural precursors is a prerequisite for obtaining basic information on brain development. Here, we examine the cell survival, proliferation, and differentiation potential of cultured neural precursors from different embryonic ages and those of the precursors expanded in vitro for different periods of time. Precursor cells were isolated at rat embryonic days 14 (E14) and 19 (E19) and cultured in the presence of a mitogen basic fibroblast growth factor (bFGF). The numbers of TUNEL+ and BrdU+ cells in E19 cortical precursor cultures were significantly lower than those in E14 cultures, indicating that the programmed cell death and proliferation potential of neural precursors are reduced during the progression of brain development. E14 cells tended to differentiate into neurons, and E19 cells into astrocytes. To determine whether the intrinsic properties of neural precursors are similarly altered during in vitro culture, E14 precursor cells were expanded for different periods. Precursor cells expanded for longer periods displayed lower apoptotic and proliferation indices, as well as astrogenic developmental potential. Clonal analysis data confirmed the transition of precursor differentiation potential from neurogenic to astrogenic over the culture period. Our findings collectively suggest that neural precursor cells undergo time-dependent changes in properties via an intrinsic program, both in vivo and in vitro.
神经前体细胞的体外培养是研究脑发育机制的有用实验工具，也是为神经退行性疾病的细胞治疗生成可再生资源的有用工具。对培养的神经前体细胞进行系统表征是获取脑发育基础信息的先决条件。在此，我们研究了来自不同胚胎年龄的培养神经前体细胞以及在体外扩增不同时间的前体细胞的细胞存活、增殖和分化潜能。在大鼠胚胎第14天（E14）和第19天（E19）分离前体细胞，并在有丝分裂原碱性成纤维细胞生长因子（bFGF）存在的情况下进行培养。E19皮质前体细胞培养物中TUNEL+和BrdU+细胞的数量显著低于E14培养物中的数量，表明在脑发育过程中神经前体细胞的程序性细胞死亡和增殖潜能降低。E14细胞倾向于分化为神经元，E19细胞倾向于分化为星形胶质细胞。为了确定神经前体细胞的内在特性在体外培养过程中是否也会发生类似变化，将E14前体细胞扩增不同时间。扩增时间较长的前体细胞表现出较低的凋亡和增殖指数，以及向星形胶质细胞分化的发育潜能。克隆分析数据证实了在培养期间前体细胞分化潜能从神经源性向星形胶质细胞源性的转变。我们的研究结果共同表明，神经前体细胞在体内和体外都会通过内在程序发生随时间变化的特性改变。
