Document Type

Article

Publication Date

12-1-2020

Description

Telomere erosion and mitochondrial dysfunction are prominent features of aging cells with progressive declines of cellular functions. Whether telomere injury induces mitochondrial dysfunction in human T lymphocytes, the major component of adaptive host immunity against infection and malignancy, remains unclear. We have recently shown that disruption of telomere integrity by KML001, a telomere-targeting drug, induces T cell senescence and apoptosis via the telomeric DNA damage response (DDR). In this study, we used KML001 to further investigate the role and mechanism of telomere injury in mitochondrial dysregulation in aging T cells. We demonstrate that targeting telomeres by KML001 induces mitochondrial dysfunction, as evidenced by increased mitochondrial swelling and decreased mitochondrial membrane potential, oxidative phosphorylation, mitochondrial DNA content, mitochondrial respiration, oxygen consumption, glycolysis, and ATP energy production. Mechanistically, we found that the KML001-induced telomeric DDR activated p53 signaling, which in turn repressed the expression of peroxisome proliferator-activated receptor-gamma coactivator 1 alpha (PGC-1α) and nuclear respiratory factor 1 (NRF-1), leading to T cell mitochondrial dysfunction. These results, forging a direct link between telomeric and mitochondrial biology, shed new light on the human T cell aging network, and demonstrate that the p53-PGC-1α-NRF-1 axis contributes to mitochondrial dysfunction in the setting of telomeric DDR. This study suggests that targeting this axis may offer an alternative, novel approach to prevent telomere damage-mediated mitochondrial and T cell dysfunctions to combat a wide range of immune aging-associated human diseases.

Copyright Statement

© The Author(s) 2020 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/

Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

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