Jordan Paivi M, Cain Lisa D, Wu Ping
Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, Texas 77555-0620, USA.
J Neurosci Res. 2008 Jan;86(1):35-47. doi: 10.1002/jnr.21460.
Establishment of an in vitro model of human cholinergic neurons would be highly desirable for understanding and developing treatment for Alzheimer's and motoneuron diseases. Previously we reported that the combination of basic fibroblast growth factor (bFGF), heparin, and laminin directs human fetal neural stem cells to form cholinergic neurons. One problem, however, is that long-term in vitro survival of these cells is low. Our goal for this study was to determine whether astrocytes or their secreted factors enhance differentiation and survival of cholinergic neurons under long-term differentiation conditions. We demonstrate here that astrocytes or astrocyte conditioned media did not enhance cholinergic differentiation but did increase the long-term survival of differentiated human neural stem cells, particularly cholinergic neurons. We further show that astrocytes protected long-term-differentiated cells from apoptotic cell death, which is at least partially mediated by astrocyte-secreted bFGF. Our findings indicate that long-term survival of human stem cell-derived cholinergic neurons requires trophic factors from nonneuronal cells. This data may provide insights into the development of an in vitro model of long-term cultured human cholinergic neurons useful for understanding of the mechanisms of cholinergic differentiation and developing treatments for neurological diseases.
建立人胆碱能神经元的体外模型对于理解和开发阿尔茨海默病及运动神经元疾病的治疗方法将非常有帮助。此前我们报道过，碱性成纤维细胞生长因子（bFGF）、肝素和层粘连蛋白的组合可引导人胎儿神经干细胞形成胆碱能神经元。然而，一个问题是这些细胞在体外的长期存活率较低。本研究的目的是确定星形胶质细胞或其分泌因子是否能在长期分化条件下增强胆碱能神经元的分化和存活。我们在此证明，星形胶质细胞或星形胶质细胞条件培养基并未增强胆碱能分化，但确实提高了分化的人神经干细胞，特别是胆碱能神经元的长期存活率。我们进一步表明，星形胶质细胞可保护长期分化的细胞免于凋亡性细胞死亡，这至少部分是由星形胶质细胞分泌的bFGF介导的。我们的研究结果表明，人干细胞来源的胆碱能神经元的长期存活需要来自非神经元细胞的营养因子。这些数据可能为建立长期培养的人胆碱能神经元体外模型提供见解，有助于理解胆碱能分化机制并开发神经系统疾病的治疗方法。
