Biomedical MRI Unit/Molecular Small Animal Imaging Center, Department of Imaging and Pathology, Faculty of Medicine, KU Leuven, Flanders, Belgium.
Wiley Interdiscip Rev Nanomed Nanobiotechnol. 2012 Nov-Dec;4(6):663-79. doi: 10.1002/wnan.1192. Epub 2012 Aug 29.
Endogenous neural stem cells (eNSCs) reside in defined regions of the adult brain and have the potential to generate new brain cells, including neurons. Stimulation of adult neurogenesis presents an enormous potential for regenerative therapies in the central nervous system. However, the methods used to monitor the proliferation, migration, differentiation, and functional integration of eNSCs and their progeny are often invasive and limited in studying dynamic processes. To overcome this limitation, novel techniques and contrast mechanisms for in vivo imaging of neurogenesis have recently been developed and successfully applied. In vivo labeling of endogenous neuronal progenitor cells in situ with contrast agents or tracers enables longitudinal visualization of their proliferation and/or migration. Labeling of these cells with magnetic nanoparticles has proven to be very useful for tracking neuroblast migration with MRI. Alternatively, genetic labeling using reporter gene technology has been demonstrated for optical and MR imaging, leading to the development of powerful tools for in vivo optical imaging of neurogenesis. More recently, the iron storage protein ferritin has been used as an endogenously produced MRI contrast agent to monitor neuroblast migration. The use of specific promoters for neuronal progenitor cell imaging increases the specificity for visualizing neurogenesis. Further improvements of detection sensitivity and neurogenesis-specific contrast are nevertheless required for each of these imaging techniques to further improve the already high utility of this toolbox for preclinical neurogenesis research.
内源性神经干细胞（eNSCs）存在于成年大脑的特定区域，具有产生新脑细胞的潜力，包括神经元。刺激成年神经发生为中枢神经系统的再生疗法提供了巨大的潜力。然而，用于监测 eNSCs 及其祖细胞的增殖、迁移、分化和功能整合的方法通常具有侵入性，并且在研究动态过程方面受到限制。为了克服这一限制，最近开发并成功应用了用于神经发生体内成像的新技术和对比机制。用对比剂或示踪剂原位标记内源性神经元祖细胞，能够进行其增殖和/或迁移的纵向可视化。用磁性纳米颗粒标记这些细胞已被证明对 MRI 追踪神经母细胞迁移非常有用。或者，使用报告基因技术进行遗传标记已被证明可用于光学和磁共振成像，从而为体内神经发生光学成像开发了强大的工具。最近，铁储存蛋白铁蛋白已被用作内源性 MRI 对比剂来监测神经母细胞的迁移。使用特定的启动子进行神经元祖细胞成像可提高观察神经发生的特异性。然而，对于这些成像技术中的每一种，都需要进一步提高检测灵敏度和神经发生特异性对比，以进一步提高该工具包在临床前神经发生研究中的高实用性。
