Krembil Neuroscience Centre, Toronto Western Hospital, University Health Network, Toronto, Ontario M5T 2S8, Canada.
J Neurosci. 2013 Jul 17;33(29):11899-915. doi: 10.1523/JNEUROSCI.1131-13.2013.
Stem cell repair shows substantial translational potential for neurological injury, but the mechanisms of action remain unclear. This study aimed to investigate whether transplanted stem cells could induce comprehensive functional remyelination. Subventricular zone (SVZ)-derived adult neural precursor cells (aNPCs) were injected bilaterally into major cerebral white matter tracts of myelin-deficient shiverer mice on postnatal day (P) 0, P7, and P21. Tripotential NPCs, when transplanted in vivo, integrated anatomically and functionally into local white matter and preferentially became Olig2+, Myelin Associated Glycoprotein-positive, Myelin Basic Protein-positive oligodendrocytes, rather than Glial Fibrillary Acidic Protein-positive astrocytes or Neurofiliment 200-positive neurons. Processes interacted with axons and transmission electron microscopy showed multilamellar axonal ensheathment. Nodal architecture was restored and by quantifying these anatomical parameters a computer model was generated that accurately predicted action potential velocity, determined by ex vivo slice recordings. Although there was no obvious phenotypic improvement in transplanted shi/shis, myelinated axons exhibited faster conduction, lower activation threshold, less refractoriness, and improved response to high-frequency stimulation than dysmyelinated counterparts. Furthermore, they showed improved resilience to ischemic insult, a promising finding in the context of perinatal brain injury. This study describes, for the first time mechanistically, the functional characteristics and anatomical integration of nonimmortalized donor SVZ-derived murine aNPCs in the dysmyelinated brain at key developmental time points.
干细胞修复在神经损伤方面显示出巨大的转化潜力,但作用机制仍不清楚。本研究旨在探讨移植的干细胞是否能诱导全面的功能髓鞘再生。在髓鞘缺失的颤抖小鼠出生后第 0、7 和 21 天,将脑室下区(SVZ)来源的成体神经前体细胞(aNPC)双侧注射到主要大脑白质束中。三潜能 NPC 在体内移植时,在解剖学和功能上整合到局部白质中,并优先成为 Olig2+、髓鞘相关糖蛋白阳性、髓鞘碱性蛋白阳性的少突胶质细胞,而不是神经胶质纤维酸性蛋白阳性的星形胶质细胞或神经丝 200 阳性的神经元。突起与轴突相互作用,透射电镜显示轴突的多层包绕。节段结构得到恢复,并通过量化这些解剖学参数,生成了一个计算机模型,该模型可以准确预测动作电位速度,由体外切片记录确定。尽管在移植的 shi/shis 中没有明显的表型改善,但髓鞘化轴突表现出更快的传导速度、更低的激活阈值、更低的不应期和对高频刺激的改善反应,与脱髓鞘对应物相比。此外,它们显示出对缺血性损伤的更强抵抗力,这是围产期脑损伤背景下的一个有希望的发现。本研究首次从机制上描述了非永生化供体 SVZ 来源的鼠 aNPC 在关键发育时间点的发育不良大脑中的功能特征和解剖学整合。