Abstract
Mitochondria play pivotal roles in cellular handling of oxygen and in apoptosis, the ordered suicide response of cells to irradiation. The involvement of expression products from the 16.5 kb human mitochondrial genome in these activities has been studied widely. However, little is known about effects of irradiation on mammalian mitochondrial DNA (mtDNA). The relative lack of mtDNA repair mechanisms compared with nuclear DNA (nDNA) predicts particular vulnerability to irradiation. Using a technique developed to ascertain mtDNA:nDNA ratios, we previously showed that this ratio increases dramatically inmurine small bowel within 48 hours followingwhole body irradiation. We now report that those levels continue to rise for four days and remain elevated at close to that level beyond 30 days after 5 Gy of irradiation.We further demonstrate that levels of the mtDNA-specific DNA polymerase-γ (Pol-γ ) also show a sharp and sustained increase during this time course after a 2-Gy dose. Paradoxically, transcription factor A (TFAM), exhibited the directly opposite response.
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Zhang, H., Maguire, D.J., Zhang, M., Zhang, L., Okunieff, P. (2011). Elevated Mitochondrial DNA Copy Number and POL-γ Expression but Decreased Expression of TFAM in Murine Intestine Following Therapeutic Dose Irradiation. In: LaManna, J., Puchowicz, M., Xu, K., Harrison, D., Bruley, D. (eds) Oxygen Transport to Tissue XXXII. Advances in Experimental Medicine and Biology, vol 701. Springer, Boston, MA. https://doi.org/10.1007/978-1-4419-7756-4_27
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DOI: https://doi.org/10.1007/978-1-4419-7756-4_27
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