Absence of superoxide dismutase activity causes nuclear DNA fragmentation during the aging process

作者：Muid Khandaker Ashfaqul; Karakaya Huseyin Caglar; Koc Ahmet^*

来源：Biochemical and Biophysical Research Communications, 2014, 444(2): 260-263.

DOI：10.1016/j.bbrc.2014.01.056

• Oxidative stress
• Antioxidant
• SOD
• Superoxide dismutase
• Aging
• Longevity
• DNA damage
• Comet assay
• ROS
• Reactive oxygen species

Superoxide dismutases (SOD) serve as an important antioxidant defense mechanism in aerobic organisms, and deletion of these genes shortens the replicative life span in the budding yeast Saccharomyces cerevisiae. Even though involvement of superoxide dismutase enzymes in ROS scavenging and the aging process has been studied extensively in different organisms, analyses of DNA damages has not been performed for replicatively old superoxide dismutase deficient cells. In this study, we investigated the roles of SOD1, SOD2 and CCS1 genes in preserving genomic integrity in replicatively old yeast cells using the single cell comet assay. We observed that extend of DNA damage was not significantly different among the young cells of wild type, sod1 Delta and sod2 Delta strains. However, ccs1 Delta mutants showed a 60% higher amount of DNA damage in the young stage compared to that of the wild type cells. The aging process increased the DNA damage rates 3-fold in the wild type and more than 5-fold in sod1 Delta,sod2 Delta, and ccs1 Delta mutant cells. Furthermore, ROS levels of these strains showed a similar pattern to their DNA damage contents. Thus, our results confirm that cells accumulate DNA damages during the aging process and reveal that superoxide dismutase enzymes play a substantial role in preserving the genomic integrity in this process.

• 出版日期2014-2-7