Altered mitochondrial function and genome frequency post exposure to gamma-radiation and bystander factors

作者：Nugent Sharon; Mothersill Carmel E; Seymour Colin; McClean Brendan; Lyng Fiona M; Murphy James E J^*

来源：International Journal of Radiation Biology, 2010, 86(10): 829-841.

DOI：10.3109/09553002.2010.486019

Materials and methods: Mitochondrial function was evaluated post direct radiation and irradiated cell conditioned medium (ICCM) by determining: Activity of the individual complexes of oxidative phosphorylation (OxPhos); mtDNA-encoded protein synthesis; and mitochondrial genome frequency and mtDNA damage.
Results: Mitochondria show a loss of OxPhos enzyme function as early as 4 h post treatment with recovery observed 12-96 h in some but not all complexes demonstrating a non-uniform sensitivity to gamma-radiation. We also identified irregular mtDNA-directed protein synthesis. Long range Polymerase Chain Reaction (PCR) analysis identified mitochondrial genome damage and real-time PCR identified increases in mitochondrial genome frequency.
Conclusions: The study reaffirms the sensitive nature of mitochondria to both low-level direct radiation exposure and radiation-induced bystander factor mediated damage. Furthermore, we report for the first time, the loss of function in the enzymes of OxPhos post exposure to bystander factors and identify altered mtDNA-directed protein synthesis post both direct radiation and bystander factors.

• 出版日期2010-10