Effect of Circadian Rhythm on Metabolic Processes and the Regulation of Energy Balance

Background: The circadian timing system or circadian clock plays a crucial role in many biological processes, such as the sleep-wake cycle, hormone secretion, cardiovascular health, glucose homeostasis, and body temperature regulation. Energy balance is also one of the most important cornerstones of metabolic processes, whereas energy imbalance is associated with many diseases (i.e., obesity, diabetes, cardiovascular disease). Circadian clock is the main regulator of metabolism, and this analysis provides an overview of the bidirectional effect of circadian rhythm on metabolic processes and energy balance. Summary: The circadian timing system or circadian clock plays a crucial role in many biological processes, but the increase in activities that operate 24/7 and the common usage of television, internet, and mobile phones almost 24 h a day leads to a gradual decrease in the adequate sleeping time. According to recent research, long-term circadian disruptions are associated with many pathological conditions such as premature mortality, obesity, impaired glucose tolerance, diabetes, psychiatric disorders, anxiety, depression, and cancer progression, whereas short-term disruptions are associated with impaired wellness, fatigue, and loss of concentration. In this review, the circadian rhythm in metabolic processes and their effect on energy balance were examined. Key Messages: Circadian rhythm has a bidirectional interaction with almost all metabolic processes. Therefore, understanding the main reason affecting the circadian clock and creating treatment guidelines using circadian rhythm may increase the success of disease treatment. Chronopharmacology, chrononutrition, and chronoexercise are the novel treatment approaches in metabolic balance.

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Independence of Circadian Timing from Cell Division in Cyanobacteria

Journal of Bacteriology ◽

10.1128/jb.183.8.2439-2444.2001 ◽

2001 ◽

Vol 183 (8) ◽

pp. 2439-2444 ◽

Cited By ~ 69

Author(s):

Tetsuya Mori ◽

Carl Hirschie Johnson

Keyword(s):

Gene Expression ◽

Cell Division ◽

Circadian Clock ◽

Clock Gene ◽

Circadian Clock Gene ◽

Circadian Timing ◽

Wide Range ◽

Timing System ◽

Circadian Timing System ◽

Cell Division Timing

ABSTRACT In the cyanobacterium Synechococcus elongatus, cell division is regulated by a circadian clock. Deletion of the circadian clock gene, kaiC, abolishes rhythms of gene expression and cell division timing. Overexpression of the ftsZ gene halted cell division but not growth, causing cells to grow as filaments without dividing. The nondividing filamentous cells still exhibited robust circadian rhythms of gene expression. This result indicates that the circadian timing system is independent of rhythmic cell division and, together with other results, suggests that the cyanobacterial circadian system is stable and well sustained under a wide range of intracellular conditions.

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The Suprachiasmatic Nucleus

Handbook of Brain Microcircuits ◽

10.1093/med/9780190636111.003.0010 ◽

2017 ◽

pp. 111-118

Author(s):

Gabriella Lundkvist ◽

Gene D. Block

Keyword(s):

Circadian Rhythm ◽

Optic Chiasm ◽

Diurnal Variations ◽

Biological Clocks ◽

Cellular Interactions ◽

Suprachiasmatic Nuclei ◽

Circadian Timing ◽

Timing System ◽

Circadian Timing System ◽

And Behavior

Diurnal variations in physiology and behavior are ubiquitous in higher organisms. Although some rhythms are driven directly by geophysical cycles of light or temperature, most are generated by internal timers, commonly referred to as biological clocks. In mammals, including humans, these circadian (near 24-h) properties are controlled by a central timer formed by a distinct regional network in the anterior hypothalamus close to the optic chiasm, the bilateral suprachiasmatic nuclei (SCN). Rodents, with their SCN lesioned, fail to exhibit diurnal variations in behavior. The mechanism generating rhythmicity is contained within individual neurons; however, many of the properties of the circadian timing system derive from cellular interactions within SCN. These microcircuits give rise to a functional clock capable of maintaining a circadian rhythm with a stable period and phase and driving or synchronizing circadian rhythms in other tissues.

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The Circadian Timing System and Environmental Circadian Disruption: From Follicles to Fertility

Endocrinology ◽

10.1210/en.2016-1450 ◽

2016 ◽

Vol 157 (9) ◽

pp. 3366-3373 ◽

Cited By ~ 18

Author(s):

Aritro Sen ◽

Michael T. Sellix

Keyword(s):

Gene Expression ◽

Molecular Clock ◽

Night Shift ◽

Hormone Secretion ◽

Circadian Disruption ◽

Pituitary Hormone ◽

Hpg Axis ◽

Circadian Timing ◽

Timing System ◽

Circadian Timing System

The internal or circadian timing system is deeply integrated in female reproductive physiology. Considerable details of rheostatic timing function in the neuroendocrine control of pituitary hormone secretion, adenohypophyseal hormone gene expression and secretion, gonadal steroid hormone biosynthesis and secretion, ovulation, implantation, and parturition have been reported. The molecular clock, an autonomous feedback loop oscillator of interacting transcriptional regulators, dictates the timing and amplitude of gene expression in each tissue of the female hypothalamic-pituitary-gonadal (HPG) axis. Although multiple targets of the molecular clock have been identified, many associated with critical physiological functions in the HPG axis, the full extent of clock-driven gene expression and physiology in this critical system remains unknown. Environmental circadian disruption (ECD), the disturbance of temporal relationships within and between internal clocks (brain and periphery), and external timing cues (eg, light, nutrients, social cues) due to rotating/night shift work or transmeridian travel have been linked to reproductive dysfunction and subfertility. Moreover, ECD resulting from exposure to endocrine disrupting chemicals, environmental toxins, and/or irregular hormone levels during sexual development can also reduce fertility. Thus, perturbations that disturb clock function at the molecular, cellular or systemic level correlate with significant declines in female reproductive function. Here we briefly review the evidence for molecular clock function in each tissue of the female HPG axis (GnRH neuron, pituitary, uterus, oviduct, and ovary), describe the human epidemiological and animal data supporting the negative effects of ECD on fertility, and explore the potential for novel chronotherapeutics in women's health and fertility.

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Faculty Opinions recommendation of The circadian timing system in clinical oncology.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.718445110.793537964 ◽

2017 ◽

Author(s):

Katja Lamia

Keyword(s):

Clinical Oncology ◽

Circadian Timing ◽

Timing System ◽

Circadian Timing System

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Dynamical Analysis of bantam-Regulated Drosophila Circadian Rhythm Model

International Journal of Bifurcation and Chaos ◽

10.1142/s0218127414501612 ◽

2014 ◽

Vol 24 (12) ◽

pp. 1450161 ◽

Cited By ~ 1

Author(s):

Ying Li ◽

Zengrong Liu

Keyword(s):

Circadian Rhythm ◽

Crucial Role ◽

Target Genes ◽

Classical Model ◽

Dynamical Analysis ◽

Biological Processes ◽

Biological Mechanisms ◽

Environmental Perturbations ◽

Dynamical Behaviors ◽

Important Regulator

MicroRNAs (miRNAs) interact with 3′untranslated region (UTR) elements of target genes to regulate mRNA stability or translation, and play a crucial role in regulating many different biological processes. bantam, a conserved miRNA, is involved in several functions, such as regulating Drosophila growth and circadian rhythm. Recently, it has been discovered that bantam plays a crucial role in the core circadian pacemaker. In this paper, based on experimental observations, a detailed dynamical model of bantam-regulated circadian clock system is developed to show the post-transcriptional behaviors in the modulation of Drosophila circadian rhythm, in which the regulation of bantam is incorporated into a classical model. The dynamical behaviors of the model are consistent with the experimental observations, which shows that bantam is an important regulator of Drosophila circadian rhythm. The sensitivity analysis of parameters demonstrates that with the regulation of bantam the system is more sensitive to perturbations, indicating that bantam regulation makes it easier for the organism to modulate its period against the environmental perturbations. The effectiveness in rescuing locomotor activity rhythms of mutated flies shows that bantam is necessary for strong and sustained rhythms. In addition, the biological mechanisms of bantam regulation are analyzed, which may help us more clearly understand Drosophila circadian rhythm regulated by other miRNAs.

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Human Circadian Timing System and Sleep-Wake Regulation

Principles and Practice of Sleep Medicine ◽

10.1016/b978-0-323-24288-2.00035-0 ◽

2017 ◽

pp. 362-376.e5 ◽

Cited By ~ 4

Author(s):

Charles A. Czeisler ◽

Orfeu M. Buxton

Keyword(s):

Circadian Timing ◽

Timing System ◽

Circadian Timing System

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Metabolic disturbances: role of the circadian timing system and sleep

Diabetology International ◽

10.1007/s13340-016-0279-6 ◽

2016 ◽

Vol 8 (1) ◽

pp. 14-22 ◽

Cited By ~ 1

Author(s):

Navin Adhikary ◽

Santosh Lal Shrestha ◽

Jia Zhong Sun

Keyword(s):

Metabolic Disturbances ◽

Circadian Timing ◽

Timing System ◽

Circadian Timing System

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The challenges of adolescent sleep

Interface Focus ◽

10.1098/rsfs.2019.0080 ◽

2020 ◽

Vol 10 (3) ◽

pp. 20190080 ◽

Cited By ~ 2

Author(s):

Gaby Illingworth

Keyword(s):

Developmental Period ◽

Sleep Health ◽

Insufficient Sleep ◽

Cognitive Health ◽

Circadian Timing ◽

Timing System ◽

Adolescent Sleep ◽

Circadian Timing System ◽

Exogenous Factors ◽

Adolescent Functioning

Sleep is vital for our physical, emotional and cognitive health. However, adolescents face many challenges where their sleep is concerned. This is reflected in their sleep patterns including the timing of their sleep and how much sleep they achieve on a regular basis: their sleep is characteristically delayed and short. Notably, insufficient sleep is associated with impairments in adolescent functioning. Endogenous and exogenous factors are known to affect sleep at this age. Alterations in the bioregulation of sleep, comprising the circadian timing system and the sleep/wake homeostatic system, represent the intrinsic mechanisms at work. Compounding this, environmental, psychosocial and lifestyle factors may contribute to shortened sleep. This review discusses the amount of sleep gained by adolescents and its implications, the challenges to adolescent sleep and the interventions introduced in an effort to prioritize sleep health in this important developmental period.

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