Shihabuddin L S, Holets V R, Whittemore S R
Neuroscience Program, University of Miami School of Medicine, Florida 33136, USA.
Exp Neurol. 1996 May;139(1):61-72. doi: 10.1006/exnr.1996.0081.
RN33B cells, a CNS-derived neuronal precursor cell line, transplanted into normal adult rat hippocampus can survive and morphologically differentiate with their ultimate morphology dependent on the integration site. This study examined the differentiation and structural integration of RN33B cells transplanted into the lesioned adult hippocampus. Pyramidal neurons of the CA1-3 regions or granular neurons in the dentate gyrus were preferentially destroyed by unilateral intraventricular kainic-acid or intradentate colchicine injections, respectively. One week after the lesion, a suspension of undifferentiated beta-galactosidase (beta-gal)-labeled RN33B cells was stereotaxically transplanted into the lesioned or the contralateral hippocampus. After 5-7 weeks, sections of the recipient brains were analyzed by toluidine blue staining and immunohistochemistry for beta-gal, GFAP, and OX-42. A reactive gliosis was observed on the lesioned side which persisted up to 7 weeks postlesion (the latest time point examined). RN33b cells survived in the lesioned hippocampus and assumed variable morphologies depending on the hippocampal layer into which they integrated. Only RN33B cells located in intact or partially damaged cell layers or in the unlesioned contralateral hippocampus differentiated with morphologies similar to those of endogenous neurons characteristic of those layers. Cells located in layers completely depleted of endogenous neurons assumed bipolar morphologies or sent out multiple processes with no structural polarity, unlike the neuronal morphologies characteristically seen in intact hippocampal cell layers. These data suggest that the presence of some endogenous neurons and partially conserved cytoarchitectural organization are essential for immortalized neuroepithelial precursor cells to differentiate into region-specific neuronal cell types.
RN33B细胞是一种源自中枢神经系统的神经前体细胞系，移植到正常成年大鼠海马体中能够存活并发生形态分化，其最终形态取决于整合位点。本研究检测了移植到成年受损海马体中的RN33B细胞的分化及结构整合情况。分别通过单侧脑室内注射 kainic 酸或齿状体内注射秋水仙碱，优先破坏CA1 - 3区域的锥体神经元或齿状回中的颗粒神经元。损伤后一周，将未分化的β - 半乳糖苷酶（β - gal）标记的RN33B细胞悬液立体定向移植到受损或对侧海马体中。5 - 7周后，对受体大脑切片进行甲苯胺蓝染色以及针对β - gal、GFAP和OX - 42的免疫组织化学分析。在损伤侧观察到反应性胶质增生，这种增生在损伤后7周（检测的最晚时间点）仍持续存在。RN33b细胞在受损海马体中存活，并根据它们所整合的海马层呈现出不同的形态。只有位于完整或部分受损细胞层或未受损对侧海马体中的RN33B细胞分化出与这些层中内源性神经元相似的形态。与完整海马体细胞层中典型的神经元形态不同，位于内源性神经元完全缺失层的细胞呈现双极形态或发出多个无结构极性的突起。这些数据表明，某些内源性神经元的存在和部分保留的细胞结构组织对于永生化神经上皮前体细胞分化为区域特异性神经元细胞类型至关重要。
