Mutations in mitochondrial DNA lead to a spectrum of neurodegenerative diseases for which no treatment exists. Almost all of them involve ocular structures that include the optic nerve, retina, extraocular muscles or eyelids. The most common of these is Leber Hereditary Optic Neuropathy (LHON) caused (in half the cases) by a mutated ND4 subunit gene of complex I in the respiratory chain. Our goal is to develop gene therapy for this mitochondrial disease by delivery of genes encoding the normal ND4 subunit to affected cells and tissues. We propose to design, modify and test an adeno-associated virus (AAV) to which a mitochondrial targeting sequence is appended to the viral envelope for delivery of its payload of DNA (a normal ND4 subunit gene), directly to the mitochondrion for rescue of cultured LHON cells and then of our animal model of LHON. Our mouse model shows optic nerve head swelling followed by optic atrophy and degeneration of retinal ganglion cells, which are characteristics of LHON patients. We developed this LHON- model by modifying the mutant human ND4 gene for expression in the nucleus then directed it to the mitochondria with a targeting sequence.
Our Specific Aims are: 1) To (a) direct the AAV virion to mitochondria of cultured cells and test for the presence and expression of the payload DNA and then (b) test this strategy for the rescue of defective respiration of LHON cells. 2) To test this strategy for delivery of the human ND4 gene to the LHON-model eye for rescue of retinal ganglion cell degeneration and optic neuropathy. As proof of the feasibility of our project we provide extensive preliminary data showing that our first generation vector is targeted to mitochondria, is expressed in cultured cells as well as the murine visual system, and that it rescues cultured LHON cells. The novel technology developed here may deliver virtually any mitochondrial gene, and thus may provide the platform to treat not only visual loss, ophthalmoparesis and ptosis, but also the myriad of disabilities including premature death experienced by patients with diseases caused by mutated mitochondrial DNA. We will share the vector with other groups whose goal it is to treat these disorders.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY017141-05
Application #
8136071
Study Section
Biology and Diseases of the Posterior Eye Study Section (BDPE)
Program Officer
Agarwal, Neeraj
Project Start
2007-09-01
Project End
2013-08-31
Budget Start
2011-09-01
Budget End
2013-08-31
Support Year
5
Fiscal Year
2011
Total Cost
$361,086
Indirect Cost
Name
University of Miami School of Medicine
Department
Ophthalmology
Type
Schools of Medicine
DUNS #
052780918
City
Coral Gables
State
FL
Country
United States
Zip Code
33146
Feuer, William J; Schiffman, Joyce C; Davis, Janet L et al. (2016) Gene Therapy for Leber Hereditary Optic Neuropathy: Initial Results. Ophthalmology 123:558-70
Talla, Venu; Koilkonda, Rajeshwari; Porciatti, Vittorio et al. (2015) Complex I subunit gene therapy with NDUFA6 ameliorates neurodegeneration in EAE. Invest Ophthalmol Vis Sci 56:1129-40
Yu, Hong; Koilkonda, Rajeshwari D; Chou, Tsung-Han et al. (2015) Consequences of zygote injection and germline transfer of mutant human mitochondrial DNA in mice. Proc Natl Acad Sci U S A 112:E5689-98
Talla, Venu; Porciatti, Vittorio; Chiodo, Vince et al. (2014) Gene therapy with mitochondrial heat shock protein 70 suppresses visual loss and optic atrophy in experimental autoimmune encephalomyelitis. Invest Ophthalmol Vis Sci 55:5214-26
Talla, Venu; Yu, Hong; Chou, Tsung-Han et al. (2013) NADH-dehydrogenase type-2 suppresses irreversible visual loss and neurodegeneration in the EAE animal model of MS. Mol Ther 21:1876-88
Yu, Hong; Koilkonda, Rajeshwari D; Chou, Tsung-Han et al. (2012) Gene delivery to mitochondria by targeting modified adenoassociated virus suppresses Leber's hereditary optic neuropathy in a mouse model. Proc Natl Acad Sci U S A 109:E1238-47
Yu, Hong; Ozdemir, Sacide S; Koilkonda, Rajeshwari D et al. (2012) Mutant NADH dehydrogenase subunit 4 gene delivery to mitochondria by targeting sequence-modified adeno-associated virus induces visual loss and optic atrophy in mice. Mol Vis 18:1668-83
Koilkonda, Rajeshwari D; Chou, Tsung-Han; Porciatti, Vittorio et al. (2010) Induction of rapid and highly efficient expression of the human ND4 complex I subunit in the mouse visual system by self-complementary adeno-associated virus. Arch Ophthalmol 128:876-83
Guy, John; Qi, Xiaoping; Koilkonda, Rajeshwari D et al. (2009) Efficiency and safety of AAV-mediated gene delivery of the human ND4 complex I subunit in the mouse visual system. Invest Ophthalmol Vis Sci 50:4205-14
Koilkonda, Rajeshwari D; Hauswirth, William W; Guy, John (2009) Efficient expression of self-complementary AAV in ganglion cells of the ex vivo primate retina. Mol Vis 15:2796-802

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