The influence of acute and chronic stress on the gene expression of the clock genes hPER1 and hPER2

,

• Publisher: Cuvillier Verlag
• Year: 2011
• Print ISBN: 9783869558691
• eBook ISBN: 9783736938694
• Edition: 1

Various health problems are associated with the disruption of circadian rhythms. In particular, psychological disturbances often show disrupted sleep-wake cycles as a symptom, suggesting a relation between a disrupted circadian clock and mental health problems suchas affective disorders, schizophrenia and addictive disorders. The mentioned vital clockworkis sustained by specific circadian oscillatory expression of clock genes – which controlthemselves via transcriptional/translational feedback loops – and influences behavioural, biochemical and physiological circadian rhythms. Increasing evidence suggests aninteraction of these so-called clock genes and glucocorticoids. For this reason, we wereinterested in the question of whether the cortisol response after awakening is associated withthe gene expression of the clock genes hPER1 and hPER2, in particular hPER1, given thatits DNA sequence disposes of a glucocorticoid-responsive element and is therefore mostlikely influenced by glucocorticoids.Data 1: We investigated thirty-one healthy men aged 20-30 combining microbiological andpsychometric methods. We measured the amount of mRNA of hPER1 and hPER2 on twoconsecutive mornings as well as twelve hours later in the evenings of the same days. Tomeasure the increase of cortisol after awakening, we sampled cortisol levels immediatelyafter, 30 minutes after and 60 minutes after awakening on both mornings. Additionally, subjects filled in questionnaires to assess their level of chronic stress. We found anassociation between the gene expression of hPER1 and age as well as the increase ofcortisol in the morning, whereas the gene expression of hPER2 seems to be associatedprimarily with age and levels of chronic stress.Data 2: Furthermore, since numerous mental health problems are associated with adisruption of the sleep-wake cycle, a disturbance of the circadian clock on a molecular levelseems likely. Simultaneously, psychosocial stress is considered as a major factor in theetiology of several mental health problems. For this reason, we aimed to investigate theputative cortisol-mediated influence of acute and chronic psychosocial stress on the geneexpression of hPER1 in thirty-one healthy men. Our findings suggest that firstly, acutepsychosocial stress influences the expression of hPER1, and secondly, chronic stressinvolves heightened gene expression of hPER1.

Table of contents

• Table of Content
• ABSTRACT
• Introduction
• PART I THEORETICAL BACKGROUND
• PART II EMPIRICAL STUDIES
• PART III GENERAL DISCUSSION
• Literature