Research Paper Volume 10, Issue 2 pp 212—228
Ultraviolet A irradiation induces senescence in human dermal fibroblasts by down-regulating DNMT1 via ZEB1
- 1 Department of Dermatology, Xiangya Hospital, Central South University, Changsha, China
- 2 Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, China
- 3 Center for Molecular Medicine, Xiangya Hospital, Central South University, Changsha, China
- 4 The State Key Laboratory of Medical Genetics & School of Life Sciences, Central South University, Changsha, China
- 5 National Clinical Research Center for Geriatric Disorders, Changsha, China
Received: September 7, 2017 Accepted: February 9, 2018 Published: February 16, 2018
https://doi.org/10.18632/aging.101383How to Cite
Copyright: Yi et al. This is an openâaccess article distributed under the terms of the Creative Commons Attribution License (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Abstract
In this study, we report the role of DNA methyltransferase 1 (DNMT1) in ultraviolet A (UVA)-induced senescence in human dermal fibroblasts (HDFs). We show that DNMT1 expression was significantly reduced during UVA-induced senescence, and this senescence could be alleviated or aggravated by the up- or down-regulation of DNMT1, respectively. Expression of the transcription factor zinc finger E-box binding homeobox 1(ZEB1) also decreased after UVA irradiation, following a UVA-induced increase of intracellular reactive oxygen species (ROS). We show that ZEB1 binds to the DMNT1 promoter and regulates its transcription, which, in turn, affects cellular senescence. These changes in DMNT1 and ZEB1 expression following UVA exposure were confirmed in matched skin specimens that had or had not been sun-exposed. On analyzing the promoter methylation of 24 senescence associated genes in these matched skin specimens, we discovered that p53 promoter methylation was significantly reduced in sun-exposed skin. In vitro experiments confirmed that UVA irradiation reduced p53 promoter methylation, and DNMT1 up-regulation could reverse this effect. Collectively, down-regulation of ZEB1 caused by UVA induced ROS could transcriptionally inhibit DNMT1, leading to low methylation level of senescence related proteins p53 and increase its expression, eventually result in cellar senescence.