Velmurugan Sindhu, Chou Tsung-Han, Eastwood Jeremy D, Porciatti Vittorio, Liu Yuan, Hauswirth William W, Guy John, Yu Hong
Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, United States.
Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, FL, United States.
Front Neurosci. 2023 Mar 27;17:1119724. doi: 10.3389/fnins.2023.1119724. eCollection 2023.
Therapies for Leber hereditary optic neuropathy (LHON), in common with all disorders caused by mutated mitochondrial DNA, are inadequate. We have developed two gene therapy strategies for the disease: mitochondrial-targeted and allotopic expressed and compared them in a mouse model of LHON.
A LHON mouse model was generated by intravitreal injection of a mitochondrialtargeted Adeno-associated virus (AAV) carrying mutant human NADH dehydrogenase 4 gene () to induce retinal ganglion cell (RGC) degeneration and axon loss, the hallmark of the human disease. We then attempted to rescue those mice using a second intravitreal injection of either mitochondrial-targeted or allotopic expressed wildtype human . The rescue of RGCs and their axons were assessed using serial pattern electroretinogram (PERG) and transmission electron microscopy.
Compared to non-rescued LHON controls where PERG amplitude was much reduced, both strategies significantly preserved PERG amplitude over 15 months. However, the rescue effect was more marked with mitochondrial-targeted therapy than with allotopic therapy ( = 0.0128). Post-mortem analysis showed that mitochondrial-targeted human better preserved small axons that are preferentially lost in human LHON.
These results in a pre-clinical mouse model of LHON suggest that mitochondrially-targeted AAV gene therapy, compared to allotopic AAV gene therapy, is more efficient in rescuing the LHON phenotype.
与所有由线粒体DNA突变引起的疾病一样，Leber遗传性视神经病变（LHON）的治疗方法并不完善。我们针对该疾病开发了两种基因治疗策略：线粒体靶向和异位表达，并在LHON小鼠模型中对它们进行了比较。
通过玻璃体内注射携带突变型人类NADH脱氢酶4基因（）的线粒体靶向腺相关病毒（AAV）来构建LHON小鼠模型，以诱导视网膜神经节细胞（RGC）变性和轴突丢失，这是人类疾病的标志。然后，我们尝试通过再次玻璃体内注射线粒体靶向或异位表达的野生型人类来挽救这些小鼠。使用系列图形视网膜电图（PERG）和透射电子显微镜评估RGC及其轴突的挽救情况。
与未挽救的LHON对照组相比，PERG振幅大幅降低，两种策略在15个月内均显著保留了PERG振幅。然而，线粒体靶向治疗的挽救效果比异位治疗更明显（=0.0128）。死后分析表明，线粒体靶向的人类能更好地保留在人类LHON中优先丢失的小轴突。
这些在LHON临床前小鼠模型中的结果表明，与异位AAV基因治疗相比，线粒体靶向AAV基因治疗在挽救LHON表型方面更有效。
