Yang Ming, Donaldson Angela E, Marshall Cheryl E, Shen James, Iacovitti Lorraine
Farber Institute for Neurosciences, Department of Neurology, Thomas Jefferson University Medical College, 900 Walnut Street, Philadelphia, PA 19107, USA.
Cell Transplant. 2004;13(5):535-47. doi: 10.3727/000000004783983729.
The development of cell replacement therapies for the treatment of neurodegenerative disorders such as Parkinson's disease (PD) may depend upon the successful differentiation of human neural stem/progenitor cells into dopamine (DA) neurons. We show here that primary human neural progenitors (HNPs) can be expanded and maintained in culture both as neurospheres (NSPs) and attached monolayers where they develop into neurons and glia. When transplanted into the 6-hydroxydopamine-lesioned rat striatum, undifferentiated NSPs survive longer (60% graft survival at 8-16 weeks vs. 30% graft survival at 8-13 weeks) and migrate farther than their attached counterparts. While both NSP and attached cells continue to express neuronal traits after transplantation, the spontaneous expression of differentiated transmitter-related traits is not observed in either cell type. However, following predifferentiation in culture using a previously described cocktail of reagents, approximately 25% of HNPs can permanently express the DA enzyme tyrosine hydroxylase (TH), even following replating and removal of the DA differentiation cocktail. When these predifferentiated HNPs are transplanted into the brain, however, TH staining is not observed, either because expression is lost or TH-expressing cells preferentially die. Consistent with the latter view is a decrease in total cell survival and migration, and an enhanced glial response in these grafts. In contrast, we found that the overall survival of HNPs is improved when cells engraft near blood vessels or CSF compartments or when they are placed into an intact unlesioned brain, suggesting that there are factors, as yet unidentified, that can better support the development of engrafted HNPs.
用于治疗帕金森病（PD）等神经退行性疾病的细胞替代疗法的发展可能取决于人类神经干细胞/祖细胞成功分化为多巴胺（DA）神经元。我们在此表明，原代人类神经祖细胞（HNPs）可以作为神经球（NSPs）和贴壁单层细胞在培养中扩增和维持，在培养过程中它们会发育成神经元和神经胶质细胞。当移植到6-羟基多巴胺损伤的大鼠纹状体中时，未分化的NSPs存活时间更长（8-16周时移植存活率为60%，而8-13周时贴壁细胞移植存活率为30%），并且比贴壁细胞迁移得更远。虽然NSPs和贴壁细胞在移植后都继续表达神经元特征，但在这两种细胞类型中均未观察到分化的递质相关特征的自发表达。然而，使用先前描述的试剂混合物在培养中进行预分化后，即使在重新铺板并去除DA分化混合物后，约25%的HNPs仍能永久表达DA酶酪氨酸羟化酶（TH）。然而，当将这些预分化的HNPs移植到大脑中时，未观察到TH染色，这要么是因为表达丢失，要么是因为表达TH的细胞优先死亡。与后一种观点一致的是，这些移植物中的总细胞存活率和迁移率降低，并且神经胶质反应增强。相比之下，我们发现当细胞植入靠近血管或脑脊液腔室附近或置于完整未损伤的大脑中时，HNPs的总体存活率会提高，这表明存在尚未确定的因素，可以更好地支持植入的HNPs的发育。
