Rapid directional shift of mitochondrial DNA heteroplasmy in animal tissues by a mitochondrially targeted restriction endonuclease

Proc Natl Acad Sci U S A. 2005 Oct 4;102(40):14392-7. doi: 10.1073/pnas.0502896102. Epub 2005 Sep 22.


Frequently, mtDNA with pathogenic mutations coexist with wild-type genomes (mtDNA heteroplasmy). Mitochondrial dysfunction and disease ensue only when the proportion of mutated mtDNAs is high, thus a reduction in this proportion should provide an effective therapy for these disorders. We developed a system to decrease specific mtDNA haplotypes by expressing a mitochondrially targeted restriction endonuclease, ApaLI, in cells of heteroplasmic mice. These mice have two mtDNA haplotypes, of which only one contains an ApaLI site. After transfection of cultured hepatocytes with mitochondrially targeted ApaLI, we found a rapid, directional, and complete shift in mtDNA heteroplasmy (2-6 h). We tested the efficacy of this approach in vivo, by using recombinant viral vectors expressing the mitochondrially targeted ApaLI. We observed a significant shift in mtDNA heteroplasmy in muscle and brain transduced with recombinant viruses. This strategy could prevent disease onset or reverse clinical symptoms in patients harboring certain heteroplasmic pathogenic mutations in mtDNA.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adenoviridae
  • Animals
  • Blotting, Southern
  • Cell Line
  • DNA Restriction Enzymes / metabolism*
  • DNA Restriction Enzymes / therapeutic use
  • DNA, Mitochondrial / genetics*
  • Female
  • Gene Targeting / methods*
  • Genetic Therapy / methods*
  • Genetic Vectors / genetics
  • Haplotypes / genetics
  • Mice
  • Mice, Inbred NZB
  • Mitochondrial Diseases / genetics*
  • Mitochondrial Diseases / therapy*
  • Mutation / genetics*
  • Polymorphism, Restriction Fragment Length


  • DNA, Mitochondrial
  • DNA Restriction Enzymes