Aging and defense against generation of 8-oxo-7,8-dihydro-2'-deoxyguanosine in DNA

TY - JOUR

T1 - Aging and defense against generation of 8-oxo-7,8-dihydro-2'-deoxyguanosine in DNA

AU - Mikkelsen, Lone

AU - Bialkowski, Karol

AU - Risom, Lotte

AU - Løhr, Mille

AU - Loft, Steffen

AU - Møller, Peter

PY - 2009

Y1 - 2009

N2 - The imbalance between the formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) in DNA and the efficiency of cellular systems of DNA protection and repair is considered an important factor in the age-dependent development of cancer. This study investigated the relationship between oxidatively damaged DNA and the activity of the DNA repair system and 8-oxo-7,8-dihydro-2'-deoxyguanosine 5'-triphosphate pyrophosphohydrolase (8-oxodGTPase) activity in liver and lung tissue from mice at 10-100 weeks of age. The level of 8-oxodG increased with age, whereas the level of formamidopyrimidine DNA glycosylase sites was unaltered. The enzyme activity toward single oxygen-induced DNA damage and mRNA expression levels of Ercc1, Neil1, and Ogg1 remained unaltered with age. However, the 8-oxodGTPase activity in the liver was 18% (95% CI: 0.2-37%) lower in mice at 25 and 50 weeks than in 10-week-old mice. The 10- and 100-week-old mice had similar 8-oxodGTPase activity. In contrast, the mRNA expression of Nudt1 was statistically unaltered that likely resulted from higher variation of measurements. The accumulation of 8-oxodG with age is not a direct consequence of decreased enzyme activity toward singlet oxygen-induced substrate DNA. An age-related higher level of 8-oxodG even occurs concomitantly with high 8-oxodGTPase activity.

AB - The imbalance between the formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) in DNA and the efficiency of cellular systems of DNA protection and repair is considered an important factor in the age-dependent development of cancer. This study investigated the relationship between oxidatively damaged DNA and the activity of the DNA repair system and 8-oxo-7,8-dihydro-2'-deoxyguanosine 5'-triphosphate pyrophosphohydrolase (8-oxodGTPase) activity in liver and lung tissue from mice at 10-100 weeks of age. The level of 8-oxodG increased with age, whereas the level of formamidopyrimidine DNA glycosylase sites was unaltered. The enzyme activity toward single oxygen-induced DNA damage and mRNA expression levels of Ercc1, Neil1, and Ogg1 remained unaltered with age. However, the 8-oxodGTPase activity in the liver was 18% (95% CI: 0.2-37%) lower in mice at 25 and 50 weeks than in 10-week-old mice. The 10- and 100-week-old mice had similar 8-oxodGTPase activity. In contrast, the mRNA expression of Nudt1 was statistically unaltered that likely resulted from higher variation of measurements. The accumulation of 8-oxodG with age is not a direct consequence of decreased enzyme activity toward singlet oxygen-induced substrate DNA. An age-related higher level of 8-oxodG even occurs concomitantly with high 8-oxodGTPase activity.

U2 - 10.1016/j.freeradbiomed.2009.05.030

DO - 10.1016/j.freeradbiomed.2009.05.030

M3 - Journal article

C2 - 19500668

SN - 0891-5849

VL - 47

SP - 608

EP - 615

JO - Free Radical Biology & Medicine

JF - Free Radical Biology & Medicine

IS - 5

ER -