Telomeres and Oxidative Stress
Nurul Fatihah Mohamad Nasir
School of Dental Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia.
Thirumulu Ponnuraj Kannan *
School of Dental Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia and Human Genome Centre, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia.
Siti Amrah Sulaiman
Department of Pharmacology, School of Medical Sciences, Universiti Sains Malaysia,16150 Kubang Kerian, Kelantan, Malaysia.
Shaharum Shamsuddin
School of Health Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia.
Azlina Ahmad
School of Dental Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia.
Stefan Stangaciu
Apitherapy Consulting and Trading International SRL, Sat Mereni, str. Principala nr. 106A, Comuna Contesti, Dambovita district, Postal code 137133, Romania.
*Author to whom correspondence should be addressed.
Abstract
Telomeres are long repetitive DNA sequences of TTAGGG located at the end of the linear chromosomes and bound by shelterin proteins. Shelterin proteins function as the protection for the loop structure of telomere, which prevents the chromosome ends uncapped; resemble a DNA break and activates DNA repair mechanism. Telomere length is maintained by an enzyme called telomerase. There are several factors that can shorten the telomeres which include telomere attrition during cell division, deficiency of Rad 54, which is involved in DNA repair and the methylation of histones H3 and histones H4, which can diminish telomerase activity. Three major mechanisms which influence the telomere length are the end-replication problem, the action of C-strand-specific exonuclease and oxidative DNA damage induced by environmental risk factors. However, oxidative stress has been shown to be the major mechanism which can influence the telomere length. This review explores the association between telomere length and oxidative stress.
Keywords: Telomere, oxidative stress, telomerase, 8-oxodG.