Track-structure simulations of energy deposition patterns to mitochondria and damage to their DNA

AbstractPurpose: Mitochondria have been implicated in initiating and/or amplifying the biological effects of ionizing radiation not mediated via damage to nuclear DNA. To help elucidate the underlying mechanisms, energy deposition patterns to mitochondria and radiation damage to their DNA have been modelled.Methods: Track-structure simulations have been performed with PARTRAC biophysical tool for 60Co γ-rays and 5 MeV α-particles. Energy deposition to the cell’s mitochondria has been analyzed. A model of mitochondrial DNA reflecting experimental information on its structure has been developed and used to assess its radiation-induced damage.Results: Energy deposition to mitochondria is highly inhomogeneous, especially at low doses. Although a dose-dependent fraction of mitochondria sees no energy deposition at all, the hit ones receive rather high amounts of energy. Nevertheless, only little damage to mitochondrial DNA occurs, even at large doses.Conclusion: Mitochondrial DNA does not represent a critical ...