Gene Therapy in a Large Animal Model of PDE6A-Retinitis Pigmentosa.
Gene Therapy in a Large Animal Model of PDE6A-Retinitis Pigmentosa.
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DOI：
10.3389/fnins.2017.00342
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发表时间：
2017
影响因子：
4.3
通讯作者：
Petersen-Jones SM
中科院分区：
文献类型：
--
作者：
Mowat FM;Occelli LM;Bartoe JT;Gervais KJ;Bruewer AR;Querubin J;Dinculescu A;Boye SL;Hauswirth WW;Petersen-Jones SM
尽管视杆磷酸二酯酶6-α（PDE 6A）基因的突变被公认为是人类视网膜色素变性的原因，但尚未开发出治疗这种致盲疾病的确定性治疗方法。我们在Pde 6a突变狗中进行了一项视网膜基因扩增试验，使用Pde 6a通过captain突变腺相关病毒血清型8进行递送，先前显示在犬视网膜中具有快速的转基因表达。在29-44日龄的10只狗中进行视网膜下注射，并进行视网膜电图和视力测试以评估功能结果。使用彩色眼底照相、光谱域光学相干断层扫描和组织学评估视网膜结构。进行免疫组织化学以检查转基因表达和其他视网膜基因的表达。治疗导致微光视力改善，视网膜电图检查显示杆功能。与对侧对照载体处理或未注射的眼睛相比，处理区域中的感光层厚度得以保留。在治疗区域观察到视杆细胞和视锥细胞存活率、视紫红质定位、环GMP水平和双极细胞树突分布得到改善。在AAV-Pde 6a和对照载体注射区域中鉴定了一些不良反应，包括视网膜分离病灶、视网膜变性病灶和玫瑰花结形成。这是首次在大型动物模型中成功描述Pde 6a视网膜色素变性的基因增强。在转化为人类研究之前，还需要进一步的研究来优化视觉结果并最大限度地减少并发症。
Despite mutations in the rod phosphodiesterase 6-alpha (PDE6A) gene being well-recognized as a cause of human retinitis pigmentosa, no definitive treatments have been developed to treat this blinding disease. We performed a trial of retinal gene augmentation in the Pde6a mutant dog using Pde6a delivery by capsid-mutant adeno-associated virus serotype 8, previously shown to have a rapid onset of transgene expression in the canine retina. Subretinal injections were performed in 10 dogs at 29–44 days of age, and electroretinography and vision testing were performed to assess functional outcome. Retinal structure was assessed using color fundus photography, spectral domain optical coherence tomography, and histology. Immunohistochemistry was performed to examine transgene expression and expression of other retinal genes. Treatment resulted in improvement in dim light vision and evidence of rod function on electroretinographic examination. Photoreceptor layer thickness in the treated area was preserved compared with the contralateral control vector treated or uninjected eye. Improved rod and cone photoreceptor survival, rhodopsin localization, cyclic GMP levels and bipolar cell dendrite distribution was observed in treated areas. Some adverse effects including foci of retinal separation, foci of retinal degeneration and rosette formation were identified in both AAV-Pde6a and control vector injected regions. This is the first description of successful gene augmentation for Pde6a retinitis pigmentosa in a large animal model. Further studies will be necessary to optimize visual outcomes and minimize complications before translation to human studies.