Biomarkers of Oxidative Stress: Methods and Measures of Oxidative DNA Damage (COMET Assay) and Telomere Shortening
Oxidative stress is fast becoming the nutritional and medical buzzword for the twenty-first century. The theoretical importance of oxidative stress in diabetes is highlighted by its potential double impact on metabolic dysfunction on one hand and the vascular system on the other hand. The new concept of oxidative stress, being an important trigger in the onset and progression of diabetes and its complications, emphasizes the need for measurement of markers of oxidation to assess the degree of oxidative stress. While we have been routinely measuring biomarkers in our molecular epidemiology projects, here we discuss the utility of two assays, (a) DNA damage assessment by COMET measurement and (b) telomere length measurement. As DNA damage is efficiently repaired by cellular enzymes, its measurement gives a snapshot view of the level of oxidative stress. The protocol allows for measurement of oxidative DNA damage (FPG-sensitive DNA strand breaks). Telomere length measured by Southern blotting technique allows one to estimate the chronic burden of oxidative stress at the molecular level and is now considered as biomarker of biological aging.
Key wordsOxidative stress telomere shortening comet assay DNA damage biomarker diabetes
This work was supported by research grants from the Department of Science and Technology (DST & DST-FIST), the Department of Biotechnology (DBT), and the Indian Council of Medical Research (ICMR), Government of India.
- 2.Balasubramanyam, M. (2006) Antioxidants and cardiovascular disease – Where do we stand? Asian J. Diabetol. 8, 1–5.Google Scholar
- 7.Adaikalakoteswari, A., Rema, M., Mohan, V., and Balasubramanyam, M. (2007). Oxidative DNA damage and augmentation of Poly (ADP-ribose) polymerase/Nuclear factor-kappa B signaling in patients with Type 2 diabetes and microangiopathy. Int. J. Biochem. Cell Biol. 39,1673–1684.CrossRefPubMedGoogle Scholar
- 9.Cadet, J., Bellon, S., Berger, M., Bourdat, A.G., Douki, T., Duarte, V., Frelon, S., Gasparutto, D., Muller, E., Ravanat, J.L., and Sauvaigo, S. (2002) Recent aspects of oxidative DNA damage: guanine lesions, measurement and substrate specificity of DNA repair glycosylases. Biol. Chem. 383, 933–943.CrossRefPubMedGoogle Scholar
- 16.Brouilette, S.W., Moore, J.S., McMahon, A.D., Thompson, J.R., Ford, I., Shepherd, J., et al. (2007) West of Scotland Coronary Prevention Study Group. Telomere length, risk of coronary heart disease, and statin treatment in the West of Scotland Primary Prevention Study: a nested case-control study. Lancet 369, 107–114.CrossRefPubMedGoogle Scholar