Leaver S G, Harvey A R, Plant G W
School of Anatomy and Human Biology and Reds Spinal Cord Research Laboratory, The University of Western Australia, Western Australia.
Glia. 2006 Apr 1;53(5):467-76. doi: 10.1002/glia.20311.
In vivo, transplanted adult olfactory ensheathing glia (OEG) and adult Schwann cells (SC) can support the regrowth of at least some transected axons within adult CNS neuropil. In the present study, we developed an in vitro adult rat retinal explant model to explore the influence of primary adult SC and OEG on retinal ganglion cell (RGC) neurite regrowth in the presence of glial cells endogenous to the retina. Retinal quadrants were plated RGC-side down onto aclar hats coated with either pure collagen (type 1), collagen with OEG, collagen with SCs, or collagen coated with both OEG and SCs. Regrowing retinal neurites extended onto the pure collagen substrate, largely in association with astrocytes that migrated out from the explants (mean number of neurites: 144+/-65 SEM). The additional presence of OEG (669+/-122), but not SCs (97+/-41), supported the regrowth of significantly greater numbers of RGC neurites. Furthermore, this OEG-stimulated regeneration was over significantly greater distances; >68% of neurites extended >500 microm from the explant, compared with explants plated onto SCs or collagen alone (15% and 29%, respectively). When OEG and SCs were co-cultured the number of regenerating neurites was reduced (397+/-81) compared with the pure OEG treatment. Analysis of explants on pure collagen substrates fed with media conditioned by purified OEG or SC showed no increase in neurite outgrowth compared with control treatments, suggesting that the enhanced growth in the presence of OEG is a contact-mediated effect. The observed differences between the abilities of OEG and SC to support the growth of CNS-derived fibers in the presence of astrocytes support the suggestion that OEG may be better suited for direct transplantation into CNS neuropil following injury.
在体内，移植的成年嗅鞘胶质细胞（OEG）和成年雪旺细胞（SC）能够支持成年中枢神经系统神经纤维网内至少一些横断轴突的再生。在本研究中，我们建立了一种体外成年大鼠视网膜外植体模型，以探讨原代成年SC和OEG在视网膜内源性胶质细胞存在的情况下对视网膜神经节细胞（RGC）神经突再生的影响。将视网膜象限以RGC面朝下的方式接种到涂有纯胶原蛋白（I型）、含OEG的胶原蛋白、含SCs的胶原蛋白或同时涂有OEG和SCs的胶原蛋白的亚克力帽上。再生的视网膜神经突延伸到纯胶原蛋白底物上，主要与从外植体迁移出来的星形胶质细胞相关（神经突平均数量：144±65 SEM）。OEG（669±122）的额外存在，但不是SCs（97±41），支持了显著更多数量的RGC神经突的再生。此外，这种OEG刺激的再生距离明显更长；与单独接种到SCs或胶原蛋白上的外植体相比（分别为15%和29%），>68%的神经突从外植体延伸>500微米。当OEG和SCs共培养时，与纯OEG处理相比，再生神经突的数量减少（397±81）。对在纯胶原蛋白底物上用纯化的OEG或SC条件培养基喂养的外植体进行分析，与对照处理相比，神经突生长没有增加，这表明在OEG存在下生长增强是一种接触介导的效应。在星形胶质细胞存在的情况下，观察到OEG和SC支持中枢神经系统衍生纤维生长的能力之间的差异，支持了OEG可能更适合在损伤后直接移植到中枢神经系统神经纤维网中的观点。
