Singh Rabindra P, Cheng Ying-Hua, Nelson Paul, Zhou Feng C
Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
Cell Transplant. 2009;18(1):55-68. doi: 10.3727/096368909788237177.
Preservation of neural stem cells (NSCs) in the adult peripheral nervous system (PNS) has recently been confirmed. However, it is not clear whether peripheral NSCs possess predestined, bona fide phenotypes or a response to innate developmental cues. In this study, we first demonstrated the longevity, multipotency, and high fidelity of sensory features of postmigrating adult dorsal root ganglia (aDRG) stem cells. Derived from aDRG and after 4-5 years in culture without dissociating, the aDRG NSCs were found capable of proliferation, expressing neuroepithelial, neuronal, and glial markers. Remarkably, these aDRG NSCs expressed sensory neuronal markers vesicular glutamate transporter 2 (VGluT2--glutamate terminals), transient receptor potential vanilloid 1 (TrpV1--capsaicin sensitive), phosphorylated 200 kDa neurofilaments (pNF200--capsaicin insensitive, myelinated), and the serotonin transporter (5-HTT), which normally is transiently expressed in developing DRG. Furthermore, in response to neurotrophins, the aDRG NSCs enhanced TrpV1 expression upon exposure to nerve growth factor (NGF), but not to brain-derived neurotrophic factor (BDNF). On the contrary, BDNF increased the expression of NeuN. Third, the characterization of aDRG NSCs was demonstrated by transplantation of red fluorescent-expressing aDRG NSCs into injured spinal cord. These cells expressed nestin, Hu, and beta-III-tubulin (immature neuronal markers), GFAP (astrocyte marker) as well as sensory neural marker TrpV1 (capsaicin sensitive) and pNF200 (mature, capsaicin insensitive, myelinated). Our results demonstrated that the postmigrating neural crest adult DRG stem cells not only preserved their multipotency but also were retentive in sensory potency despite the age and long-term ex vivo status.
成年外周神经系统（PNS）中神经干细胞（NSCs）的保存最近已得到证实。然而，尚不清楚外周神经干细胞是否具有预定的、真正的表型或对先天发育信号的反应。在本研究中，我们首先证明了成年后迁移的背根神经节（aDRG）干细胞的寿命、多能性和感觉特征的高保真度。源自aDRG并在不解离的情况下培养4-5年后，发现aDRG神经干细胞能够增殖，表达神经上皮、神经元和神经胶质标记物。值得注意的是，这些aDRG神经干细胞表达感觉神经元标记物囊泡谷氨酸转运体2（VGluT2——谷氨酸末端）、瞬时受体电位香草酸受体1（TrpV1——对辣椒素敏感）、磷酸化的200 kDa神经丝（pNF200——对辣椒素不敏感、有髓鞘）和5-羟色胺转运体（5-HTT），5-HTT通常在发育中的背根神经节中短暂表达。此外，响应神经营养因子，aDRG神经干细胞在暴露于神经生长因子（NGF）时增强TrpV1表达，但对脑源性神经营养因子（BDNF）无反应。相反，BDNF增加了NeuN的表达。第三，通过将表达红色荧光的aDRG神经干细胞移植到受损脊髓中来证明aDRG神经干细胞的特征。这些细胞表达巢蛋白、Hu和β-III-微管蛋白（未成熟神经元标记物）、GFAP（星形胶质细胞标记物）以及感觉神经标记物TrpV1（对辣椒素敏感）和pNF200（成熟、对辣椒素不敏感、有髓鞘）。我们的结果表明，迁移后的神经嵴成年背根神经节干细胞不仅保留了它们的多能性，而且尽管年龄和长期体外状态，仍保留感觉能力。
