AUTHOR=Velmurugan Sindhu , Chou Tsung-Han , Eastwood Jeremy D. , Porciatti Vittorio , Liu Yuan , Hauswirth William W. , Guy John , Yu Hong TITLE=Comparison of different gene-therapy methods to treat Leber hereditary optic neuropathy in a mouse model JOURNAL=Frontiers in Neuroscience VOLUME=Volume 17 - 2023 YEAR=2023 URL=https://www.frontiersin.org/journals/neuroscience/articles/10.3389/fnins.2023.1119724 DOI=10.3389/fnins.2023.1119724 ISSN=1662-453X ABSTRACT=Therapies for Leber hereditary optic neuropathy (LHON), in common with all disorders caused by mutated mtDNA, are inadequate. We have developed two strategies: mitochondrial-targeted and allotopic expressed gene therapies. Here, we intravitreally injected mitochondrial-targeted Adeno-associated virus (AAV) carrying mutant human NADH dehydrogenase 4 gene (hND4G11778A) to induce retinal ganglion cell degeneration and their axon loss, the most common features of LHON, in mice. We then attempted to rescue those mice using mitochondrial-targeted and allotopic expressed wildtype human ND4. Compared to the corresponding non-rescue controls, both strategies significantly preserved mouse retinal ganglion cell functions as assessed by serial pattern electroretinogram. However, the rescue effect is more efficient with mitochondrial-targeted therapy than with allotopic therapy (p=0.0128). Postmortem analysis showed that mitochondrial-targeted human ND4 preserved small axons that are preferentially lost in human LHON. These results suggest that mitochondrial-targeted AAV gene therapy, compared to allotopic AAV gene therapy, is more efficient in rescuing the LHON phenotype.