Di Polo A, Aigner L J, Dunn R J, Bray G M, Aguayo A J
Centre for Research in Neuroscience, The Montreal General Hospital Research Institute and McGill University, Montréal, PQ, Canada H3G 1A4.
Proc Natl Acad Sci U S A. 1998 Mar 31;95(7):3978-83. doi: 10.1073/pnas.95.7.3978.
In this study, we demonstrate that: (i) injection of an adenovirus (Ad) vector containing the brain-derived neurotrophic factor (BDNF) gene (Ad.BDNF) into the vitreous chamber of adult rats results in selective transgene expression by Müller cells; (ii) in vitro, Müller cells infected with Ad.BDNF secrete BDNF that enhances neuronal survival; (iii) in vivo, Ad-mediated expression of functional BDNF by Müller cells, temporarily extends the survival of axotomized retinal ganglion cells (RGCs); 16 days after axotomy, injured retinas treated with Ad.BDNF showed a 4.5-fold increase in surviving RGCs compared with control retinas; (iv) the transient expression of the BDNF transgene, which lasted approximately 10 days, can be prolonged with immunosuppression for at least 30 days, and such Ad-mediated BDNF remains biologically active, (v) persistent expression of BDNF by infected Müller cells does not further enhance the survival of injured RGCs, indicating that the effect of this neurotrophin on RGC survival is limited by changes induced by the lesion within 10-16 days after optic nerve transection rather than the availability of BDNF. Thus, Ad-transduced Müller cells are a novel pathway for sustained delivery of BDNF to acutely-injured RGCs. Because these cells span the entire thickness of the retina, Ad-mediated gene delivery to Müller cells may also be useful to influence photoreceptors and other retinal neurons.
在本研究中，我们证明：(i) 将含有脑源性神经营养因子 (BDNF) 基因的腺病毒 (Ad) 载体 (Ad.BDNF) 注入成年大鼠的玻璃体内，可导致 Müller 细胞选择性表达转基因；(ii) 在体外，感染 Ad.BDNF 的 Müller 细胞分泌可增强神经元存活的 BDNF；(iii) 在体内，Müller 细胞通过 Ad 介导的功能性 BDNF 表达可暂时延长轴突切断的视网膜神经节细胞 (RGCs) 的存活时间；轴突切断后 16 天，用 Ad.BDNF 处理的损伤视网膜与对照视网膜相比，存活的 RGCs 增加了 4.5 倍；(iv) BDNF 转基因的瞬时表达持续约 10 天，通过免疫抑制可延长至少 30 天，且这种 Ad 介导的 BDNF 仍具有生物活性；(v) 感染的 Müller 细胞持续表达 BDNF 并不会进一步提高损伤 RGCs 的存活率，这表明这种神经营养因子对 RGCs 存活的影响受视神经横断后 10 - 16 天内损伤诱导的变化限制，而非 BDNF 的可用性。因此，Ad 转导的 Müller 细胞是向急性损伤的 RGCs 持续递送 BDNF 的新途径。由于这些细胞贯穿视网膜的整个厚度，Ad 介导的向 Müller 细胞的基因递送可能也有助于影响光感受器和其他视网膜神经元。
