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Lookup NU author(s): Dr Gavin RichardsonORCiD, Dr Karim Bennaceur, Emily Dookun, Lilia Draganova, Dr Gabriele Saretzki, Professor Ioakim SpyridopoulosORCiD
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
Objective—Atherosclerosis is an age-related disease characterized by systemic oxidative stress and low-grade inflammation. The role of telomerase and telomere length in atherogenesis remains contentious. Short telomeres of peripheral leukocytes are predictive for coronary artery disease. Conversely, attenuated telomerase has been demonstrated to be protective for atherosclerosis. Hence, a potential causative role of telomerase in atherogenesis is critically debated.Approach and Results—In this study, we used multiple mouse models to investigate the regulation of telomerase under oxidative stress as well as its impact on atherogenesis in vitro and in vivo. Using primary lymphocytes and myeloid cell cultures, we demonstrate that cultivation under hyperoxic conditions induced oxidative stress resulting in chronic activation of CD4+ cells and significantly reduced CD4+ T-cell proliferation. The latter was telomerase dependent because oxidative stress had no effect on the proliferation of primary lymphocytes isolated from telomerase knockout mice. In contrast, myeloid cell proliferation was unaffected by oxidative stress nor reliant on telomerase. Telomerase reverse transcriptase deficiency had no effect on regulatory T-cell (Treg) numbers in vivo or suppressive function ex vivo. Adoptive transfer of telomerase reverse transcriptase–/– Tregs into Rag2–/– ApoE–/– double knockout mice demonstrated that telomerase function was not required for the ability of Tregs to protect against atherosclerosis. However, telomere length was critical for Treg function.Conclusions—Telomerase contributes to lymphocyte proliferation but plays no major role in Treg function, provided that telomere length is not critically short. We suggest that oxidative stress may contribute to atherosclerosis via suppression of telomerase and acceleration of telomere attrition in Tregs.
Author(s): Richardson G, Sage A, Bennaceur K, Al Zhrany N, Coelho-Lima J, Dookun E, Draganova L, Saretzki G, Breault D, Mallat Z, Spyridopoulos I
Publication type: Article
Publication status: Published
Journal: Arteriosclerosis, Thrombosis, and Vascular Biology
Year: 2018
Volume: 38
Issue: 6
Pages: 1283-1296
Print publication date: 01/06/2018
Online publication date: 29/03/2018
Acceptance date: 05/03/2018
Date deposited: 05/04/2018
ISSN (print): 1079-5642
ISSN (electronic): 1524-4636
Publisher: American Heart Association
URL: https://doi.org/10.1161/ATVBAHA.117.309940
DOI: 10.1161/ATVBAHA.117.309940
PubMed id: 29599138
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