TITLE:
Effects of Psychosocial Stress on the Gene Expression of the Clock Genes hPER1 and hPER2 in Humans
AUTHORS:
Elvira A. Abbruzzese, Thomas Birchler, Ulrike Ehlert
KEYWORDS:
Circadian Rhythm; Clock Genes; Cortisol; Gene Expression; hPER1; hPER2; Psychosocial Stress; Biological Clock
JOURNAL NAME:
Psychology,
Vol.5 No.1,
January
26,
2014
ABSTRACT: The circadian clock is a self-sustained time-keeping system which
controls behavioral, biochemical and physiological rhythmic processes. In mammals, the cogwheels of this
clock are the so-called clock genes which control their own expression via
several feedback loops. One of these genes is hPER1, a clock gene which disposes of a glucocorticoid-responsive
element and might therefore be influenced by glucocorticoids. In humans, stress
is associated with an increase in the glucocorticoid cortisol and is seen as a
major factor in the etiology of numerous mental health problems. For this
reason, our goal was to investigate the putative cortisol-mediated influence of
acute and chronic psychosocial stress on the gene expression of hPER1 as well as hPER2, another related clock gene from the same family. We therefore
applied laboratory psychosocial stress to thirty-one healthy men and measured
cortisol as well as mRNA levels of hPER1
and hPER2. Our main findings suggest
that acute psychosocial stress influences the expression of hPER1 and hPER2 dependent on the subjective experience of chronic stress. We
therefore conclude that the reactivity to acute stress on the gene expression
level of these two genes differs significantly between subjects with high
chronic stress compared to subjects with low chronic stress.