Telomere length of the skin in association with chronological aging and photoaging

Background: Tetomere shortening has been implicated in cellular senescence, which may cause certain aging phenotypes. Objective: To reveal whether telomere shortening is associated with chronological aging and/or photoaging of the skin, we measured telomere length in the epidermis and in the dermis from sun-protected and from sun-exposed sites of the skin. Methods: Seventy-six specimens of epidermis from sun-protected sites and 24 specimens of epidermis from sun-exposed sites were analyzed. Sixty specimens of the dermis were also analyzed. In six cases, epidermal specimens from sun-protected and from sun-exposed sites of the same individual were analyzed. Results: Comparison of tetomere lengths revealed that the epidermis has shorter telomeres than the dermis. Telomere length in the epidermis and in the dermis was reduced with age, and average tetomere shortening rates in the epidermis and in the dermis were 9 and 11 bp/yr, respectively. Unexpectedly, tetomere length was not significantly different between epidermis from sun-exposed sites and from sunprotected sites. Conclusion: We could not show the evidence that tetomere shortening is associated with photoaging of the skin. (c) 2006 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.