Related Experiment Video
Updated: May 23, 2026
06:53
Parallel Measurement of Circadian Clock Gene Expression and Hormone Secretion in Human Primary Cell Cultures
Published on: November 11, 2016
Entrainment of peripheral clock genes by cortisol
Panteleimon D Mavroudis1, Jeremy D Scheff, Steve E Calvano
1Department of Chemical and Biochemical Engineering, Rutgers University, Piscataway, New Jersey, USA.
Physiological Genomics
|April 19, 2012
Summary
Peripheral clocks in mammals, regulated by the central pacemaker (SCN), synchronize with bodily rhythms. Disruptions in cortisol signaling can lead to desynchronization of these peripheral clocks, impacting overall health.
Area of Science:
- Chronobiology
- Mammalian physiology
- Molecular clock mechanisms
Background:
- Circadian rhythmicity is essential for mammalian physiology, primarily governed by the suprachiasmatic nucleus (SCN).
- Peripheral tissues synchronize their molecular clocks to central cues and systemic signals like feeding and hormones.
- Cortisol serves as a key systemic cue influencing peripheral clock gene entrainment.
Purpose of the Study:
- To develop a semimechanistic model for cortisol-mediated entrainment of peripheral clock genes.
- To investigate the impact of entrainer characteristics on peripheral clock synchronization.
- To explore the consequences of disrupted cortisol signaling on peripheral clock function.
Main Methods:
- Development of a mathematical model simulating peripheral clock gene entrainment by cortisol.
- Analysis of model predictions regarding synchrony and phase shifts under varying cortisol dynamics.
- Comparison of model outputs with clinical observations in conditions like chronic stress and cancer.
Main Results:
- The model highlights the critical role of cortisol's amplitude and frequency in maintaining peripheral clock gene synchrony.
- Predictions indicate a loss of intercellular synchrony when cortisol deviates from its homeostatic range.
- A dynamic entrainment regime was predicted, where clocks desynchronize from cortisol but maintain internal synchrony.
Conclusions:
- Cortisol's rhythmic properties are crucial for synchronizing peripheral molecular clocks.
- Deviations in cortisol rhythmicity, as seen in stress and cancer, can lead to peripheral clock desynchronization.
- The model underscores the importance of SCN-peripheral communication for maintaining organismal rhythmicity.
Related Concept Videos
02:19Circadian Rhythms and Gene Regulation
The biological clock is involved in many aspects of regulating complex physiology in all animals. It was in 1935 when German zoologists, Hans Kalmus and Erwin Bünning, discovered the existence of circadian rhythm in Drosophila melanogaster. However, the internal molecular mechanisms behind the circadian clock remained a mystery until 1984, when Jeffrey C. Hall, Michael Rosbash, and Michael W. Young discovered the expression of the Per gene oscillating over a 24-hour cycle. In subsequent years,...
02:19Circadian Rhythms and Gene Regulation
The biological clock is involved in many aspects of regulating complex physiology in all animals. It was in 1935 when German zoologists, Hans Kalmus and Erwin Bünning, discovered the existence of circadian rhythm in Drosophila melanogaster. However, the internal molecular mechanisms behind the circadian clock remained a mystery until 1984, when Jeffrey C. Hall, Michael Rosbash, and Michael W. Young discovered the expression of the Per gene oscillating over a 24-hour cycle. In subsequent years,...
01:19Cushing Syndrome II: Pathophysiology
Cortisol production is normally governed by the hypothalamic–pituitary–adrenal (HPA) axis, which maintains hormonal balance through tightly regulated feedback mechanisms. Disruption of this regulatory system is central to the development of Cushing syndrome, whether the excess cortisol originates from external medications or internal pathology. Persistent cortisol elevation alters metabolism, immune function, and endocrine signaling, producing the characteristic clinical features of the...
02:45Biological Clocks and Seasonal Responses
The circadian—or biological—clock is an intrinsic, timekeeping, molecular mechanism that allows plants to coordinate physiological activities over 24-hour cycles called circadian rhythms. Photoperiodism is a collective term for the biological responses of plants to variations in the relative lengths of dark and light periods. The period of light-exposure is called the photoperiod.
01:37Hypothalamic-Pituitary Axis
The response to stress—be it physical or psychological, acute or chronic—involves activation of the Hypothalamic-Pituitary-Adrenal (HPA) axis. The HPA axis is part of the neuroendocrine system because it involves both neuronal and hormonal communication. Its function is to regulate homeostatic systems—metabolic, cardiovascular, and immune—providing the necessary means to respond to a stressor.
01:26Cushing Syndrome I: Introduction
Cushing syndrome refers to the collection of clinical manifestations that arise when tissues are exposed to excessive amounts of cortisol or cortisol-like medications over an extended period. Cortisol, a glucocorticoid produced by the adrenal cortex, regulates metabolism, immune responses, and the body’s adaptation to stress. When its concentration remains chronically elevated, these physiological pathways become dysregulated, resulting in the characteristic features of the syndrome.Exogenous...