| Literature DB >> 24218554 |
Jaakko L O Pohjoismäki1, Siôn L Williams, Thomas Boettger, Steffi Goffart, Johnny Kim, Anu Suomalainen, Carlos T Moraes, Thomas Braun.
Abstract
Mitochondrial DNA (mtDNA) in adult human heart is characterized by complex molecular forms held together by junctional molecules of unknown biological significance. These junctions are not present in mouse hearts and emerge in humans during postnatal development, concomitant with increased demand for oxidative metabolism. To analyze the role of mtDNA organization during oxidative stress in cardiomyocytes, we used a mouse model, which recapitulates the complex mtDNA organization of human hearts by overexpression of the mitochondrial helicase, TWINKLE. Overexpression of TWINKLE rescued the oxidative damage induced replication stalling of mtDNA, reduced mtDNA point mutation load, and modified mtDNA rearrangements in heterozygous mitochondrial superoxide dismutase knockout hearts, as well as ameliorated cardiomyopathy in mice superoxide dismutase knockout in a p21-dependent manner. We conclude that mtDNA integrity influences cell survival and reason that tissue specific modes of mtDNA maintenance represent an adaptation to oxidative stress.Entities:
Keywords: mtDNA mutations; recombination; repair
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Year: 2013 PMID： 24218554 PMCID： PMC3845095 DOI： 10.1073/pnas.1303046110
Source DB: PubMed Journal: Proc Natl Acad Sci U S A ISSN： 0027-8424 Impact factor: 11.205