DURHAM, N.C. For years, researchers have published papers that associate chronic stress with chromosomal damage.
Now researchers at Duke University Medical Center have discovered a mechanism that helps to explain the stress response in terms of DNA damage.
"We believe this paper is the first to propose a specific mechanism through which a hallmark of chronic stress, elevated adrenaline, could eventually cause DNA damage that is detectable," said senior author Robert J. Lefkowitz, M.D., James B. Duke Professor of Medicine and Biochemistry and a Howard Hughes Medical Institute (HHMI) investigator at Duke University Medical Center.
The paper was published in the Aug. 21 online issue of Nature.
In the study, mice were infused with an adrenaline-like compound that works through a receptor called the beta adrenergic receptor that Lefkowitz has studied for many years. The scientists found that this model of chronic stress triggered certain biological pathways that ultimately resulted in accumulation of DNA damage.
"This could give us a plausible explanation of how chronic stress may lead to a variety of human conditions and disorders, which range from merely cosmetic, like graying hair, to life-threatening disorders like malignancies," Lefkowitz said.
P53 is a tumor suppressor protein and is considered a "guardian of the genome" one that prevents genomic abnormalities.
"The study showed that chronic stress leads to prolonged lowering of p53 levels," said Makoto Hara, Ph.D., a postdoctoral fellow in the Lefkowitz laboratory. "We hypothesize that this is the reason for the chromosomal irregularities we found in these chronically stressed mice."
Lefkowitz earlier had proved the existence of isolated, and characterized the G-protein-coupled receptors (GPCRs) such as the beta adrenergic receptor. These receptors, which are located on the surface of the membranes that surround cells, are the
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Duke University Medical Center