Stress and Telomere Shortening: Insights from Cellular Mechanisms

Author: Jue Lin1, Elissa Epel2
Affiliation: <sup>1</sup> UCSF Department of Biochemistry and Biophysics, San Francisco, CA, United States of America. <sup>2</sup> UCSF Department of Psychiatry and Behavioral Sciences, San Francisco, CA, United States of America.
Conference/Journal: Ageing Res Rev
Date published: 2021 Nov 1
Other: Special Notes: doi: 10.1016/j.arr.2021.101507. , Word Count: 303


Short telomeres confer risk of degenerative diseases. Chronic psychological stress can lead to disease through many pathways, and research from in vitro studies to human longitudinal studies has pointed to stress-induced telomere damage as an important pathway. However, there has not been a comprehensive model to describe how changes in stress physiology and neuroendocrine pathways can lead to changes in telomere biology. Critically short telomeres or the collapse of the telomere structure caused by displacement of telomere binding protein complex shelterin elicit a DNA damage response and lead to senescence or apoptosis. In this narrative review, we summarize the key roles glucocorticoids, reactive oxygen species (ROS) and mitochondria, and inflammation play in mediating the relationship between psychological stress and telomere maintenance. We emphasis that these mediators are inter-connected and reinforce each other in positive feedback loops. Telomere length has not been studied across the lifespan yet, but the initial setting point at birth appears to be the most influential point, as it sets the lifetime trajectory, and is influenced by stress. We describe two types of intergenerational stress effects on telomeres - prenatal stress effects on telomeres during fetal development, and 'telotype transmission" -the directly inherited transmission of short telomeres from parental germline. It is clear that the initial simplistic view of telomere length as a mitotic clock has evolved into a far more complex picture of both transgenerational telomere influences, and of interconnected molecular and cellular pathways and networks, as hallmarks of aging where telomere maintenance is a key player interacting with mitochondria. Further mechanistic investigations, testing this comprehensive model of stress mediators shaping telomere biology and the telomere-mitochondrial nexus will lead to better understanding from cell to human lifespan aging, and could lead to anti-aging interventions.

Keywords: glucocorticoid; inflammation; reactive oxidative species; shelterin complex; stress; telomerase; telomeres.

PMID: 34736994 DOI: 10.1016/j.arr.2021.101507