title: Functional expression of the single subunit NADH dehydrogenase in mitochondria in vivo: a potential therapy for complex I deficiencies.
abstract: It has been reported that defects of mitochondrial proton-translocating NADH-quinone oxidoreductase (complex I) are involved in many human diseases (such as encephalomyopathies and sporadic Parkinson's disease). However, no effective remedies have been established for complex I deficiencies. We have adopted a gene therapy approach utilizing the NDI1 gene that codes for the single subunit NADH dehydrogenase of Saccharomyces cerevisiae (Ndi1). Our earlier experiments show that the Ndi1 protein can replace or supplement the functionality of complex I in various cultured cells. For this approach to be useful, it is important to demonstrate in vivo that the mature protein is correctly placed in mitochondria. In this study, we have attempted in vivo expression of the NDI1 gene in skeletal muscles and brains (substantia nigra and striatum) of rodents. In all tissues tested, the Ndi1 protein was identified in the injected area by immunohistochemical staining at 1-2 weeks after the injection. Sustained expression was observed for at least 7 months. Double-staining of the sections using antibodies against Ndi1 and F(1)-ATPase revealed that the expressed Ndi1 protein was predominantly localized to mitochondria. In addition, the tissue cells expressing the Ndi1 protein stimulated the NADH dehydrogenase activity, suggesting that the expressed Ndi1 is functionally active. It was also confirmed that the Ndi1 expression induced no inflammatory response in the tissues examined. The data indicate that the NDI1 gene will be a promising therapeutic tool in the treatment of encephalomyopathies and neurodegenerative diseases caused by complex I impairments.
authors.affiliation: Division of Biochemistry, Department of Molecular and Experimental Medicine, Scripps Research Institute, La Jolla, CA 92037, USA.
authors.forename: Byoung Boo
authors.initials: BB
authors.lastname: Seo
authors.forename: Eiko
authors.initials: E
authors.lastname: Nakamaru-Ogiso
authors.forename: Pedro
authors.initials: P
authors.lastname: Cruz
authors.forename: Terence R
authors.initials: TR
authors.lastname: Flotte
authors.forename: Takao
authors.initials: T
authors.lastname: Yagi
authors.forename: Akemi
authors.initials: A
authors.lastname: Matsuno-Yagi
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism; D000229:Dependovirus / Q000235:genetics / Q000378:metabolism; D042967:Electron Transport Complex I; D005260:Female; D015316:Genetic Therapy; D007120:Immunochemistry; D007249:Inflammation / Q000378:metabolism; D008297:Male; D051379:Mice; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism*; D017237:Mitochondrial Encephalomyopathies / Q000628:therapy; D018482:Muscle, Skeletal / Q000378:metabolism; D009245:NADH Dehydrogenase / Q000235:genetics* / Q000378:metabolism; D010300:Parkinson Disease / Q000628:therapy; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D006180:Proton-Translocating ATPases / Q000378:metabolism; D051381:Rats; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: C493237:Ndi1 protein, S cerevisiae; D021122:Protein Subunits; D029701:Saccharomyces cerevisiae Proteins; D009245:NADH Dehydrogenase; D006180:Proton-Translocating ATPases; D042967:Electron Transport Complex I