scholarly journals Low Temperature Effect on the Endocrine and Circadian Systems of Adult Danio rerio

2021 ◽  
Vol 12 ◽  
Author(s):  
Cristhian D. Sua-Cespedes ◽  
Daniela Dantas David ◽  
José A. Souto-Neto ◽  
Otoniel Gonçalves Lima ◽  
Maria Nathália Moraes ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Low Temperature ◽  
Danio Rerio ◽  
Clock Genes ◽  
Biological Rhythms ◽  
Melatonin Receptors ◽  
Thermal Changes ◽  
Central Clock ◽  
Lower Temperature ◽  
The Brain

The control of the biological rhythms begins with the activation of photo- and thermosensitive cells located in various organs of the fish such as brain, eye, and skin, but a central clock is still to be identified in teleosts. Thermal changes are stressors which increase cortisol and affect the rhythm of other hormones such as melatonin and growth hormone (GH), in both endo- and ectothermic organisms. Our aim was to investigate how temperature (23°C for 6 days) lower than the optimal (28°C) modulates expression of several gene pathways including growth hormone (gh1) and its receptors (ghra, ghrb), insulin-like growth factor1 (igf1a, igf1b) and its receptors (igf1ra, igf1rb), cortisol and its receptor (gr), the limiting enzyme of melatonin synthesis (arylalkylamine N-acetyltransferase, aanat) and melatonin receptors (mtnr1aa, mtnr1bb), as well as their relationship with clock genes in Danio rerio in early light and early dark phases of the day. Lower temperature reduced the expression of the hormone gene gh1, and of the related receptors ghra, ghrb, igf1ra, and igf1rb. Cortisol levels were higher at the lower temperature, with a decrease of its receptor (gr) transcripts in the liver. Interestingly, we found higher levels of aanat transcripts in the brain at 23°C. Overall, lower temperature downregulated the transcription of hormone related genes and clock genes. The results suggest a strong correlation of temperature challenge with the clock molecular mechanism and the endocrine systems analyzed, especially the growth hormone and melatonin axes, in D. rerio tissues.

scholarly journals The Development and Decay of the Circadian Clock in Drosophila melanogaster

2019 ◽  
Vol 1 (4) ◽  
pp. 489-500
Author(s):  
Jia Zhao ◽  
Guy Warman ◽  
James Cheeseman
Keyword(s):  
Circadian Clock ◽  
Clock Genes ◽  
Firefly Luciferase ◽  
Whole Body ◽  
Drosophila Model ◽  
Central Clock ◽  
Development And Aging ◽  
Central Oscillator ◽  
The Brain ◽  
Insight Into

The way in which the circadian clock mechanism develops and decays throughout life is interesting for a number of reasons and may give us insight into the process of aging itself. The Drosophila model has been proven invaluable for the study of the circadian clock and development and aging. Here we review the evidence for how the Drosophila clock develops and changes throughout life, and present a new conceptual model based on the results of our recent work. Firefly luciferase lines faithfully report the output of known clock genes at the central clock level in the brain and peripherally throughout the whole body. Our results show that the clock is functioning in embryogenesis far earlier than previously thought. This central clock in the fly remains robust throughout the life of the animal and only degrades immediately prior to death. However, at the peripheral (non-central oscillator level) the clock shows weakened output as the animal ages, suggesting the possibility of the breakdown in the cohesion of the circadian network.

scholarly journals Fast oxygen ion migration in Cu–In–oxide bulk and its utilization for effective CO2 conversion at lower temperature

2021 ◽  
Author(s):  
Jun-Ichiro Makiura ◽  
Takuma Higo ◽  
Yutaro Kurosawa ◽  
Kota Murakami ◽  
Shuhei Ogo ◽  
...  
Keyword(s):  
Low Temperature ◽  
Water Gas Shift ◽  
Chemical Looping ◽  
Co2 Conversion ◽  
Ion Migration ◽  
Oxygen Ion ◽  
Reverse Water Gas Shift ◽  
Oxygen Ion Migration ◽  
Lower Temperature ◽  
Water Gas

Efficient activation of CO2 at low temperature was achieved by reverse water–gas shift via chemical looping (RWGS-CL) by virtue of fast oxygen ion migration in a Cu–In structured oxide, even at lower temperatures.

scholarly journals Chronothyroidology: Chronobiological Aspects in Thyroid Function and Diseases

Life ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 426
Author(s):  
Giuseppe Bellastella ◽  
Maria Ida Maiorino ◽  
Lorenzo Scappaticcio ◽  
Annamaria De Bellis ◽  
Silvia Mercadante ◽  
...  
Keyword(s):  
Thyroid Function ◽  
Biological Rhythms ◽  
Cellular Level ◽  
Scientific Discipline ◽  
Biological Phenomena ◽  
Pituitary Thyroid Axis ◽  
Circadian Organization ◽  
Thyroid Axis ◽  
Central Clock ◽  
Thyroid Dysfunctions

Chronobiology is the scientific discipline which considers biological phenomena in relation to time, which assumes itself biological identity. Many physiological processes are cyclically regulated by intrinsic clocks and many pathological events show a circadian time-related occurrence. Even the pituitary–thyroid axis is under the control of a central clock, and the hormones of the pituitary–thyroid axis exhibit circadian, ultradian and circannual rhythmicity. This review, after describing briefly the essential principles of chronobiology, will be focused on the results of personal experiences and of other studies on this issue, paying particular attention to those regarding the thyroid implications, appearing in the literature as reviews, metanalyses, original and observational studies until 28 February 2021 and acquired from two databases (Scopus and PubMed). The first input to biological rhythms is given by a central clock located in the suprachiasmatic nucleus (SCN), which dictates the timing from its hypothalamic site to satellite clocks that contribute in a hierarchical way to regulate the physiological rhythmicity. Disruption of the rhythmic organization can favor the onset of important disorders, including thyroid diseases. Several studies on the interrelationship between thyroid function and circadian rhythmicity demonstrated that thyroid dysfunctions may affect negatively circadian organization, disrupting TSH rhythm. Conversely, alterations of clock machinery may cause important perturbations at the cellular level, which may favor thyroid dysfunctions and also cancer.

scholarly journals Understanding Quantitative Circadian Regulations Are Crucial Towards Advancing Chronotherapy

Cells ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 883 ◽  
Author(s):  
Debajyoti Chowdhury ◽  
Chao Wang ◽  
Ai-Ping Lu ◽  
Hai-Long Zhu
Keyword(s):  
Circadian Rhythms ◽  
Molecular Mechanisms ◽  
Temporal Stability ◽  
Biological Rhythms ◽  
Integrative Approach ◽  
Peripheral Tissues ◽  
Innovative Strategies ◽  
Neural Connections ◽  
Core Components ◽  
The Brain

Circadian rhythms have a deep impact on most aspects of physiology. In most organisms, especially mammals, the biological rhythms are maintained by the indigenous circadian clockwork around geophysical time (~24-h). These rhythms originate inside cells. Several core components are interconnected through transcriptional/translational feedback loops to generate molecular oscillations. They are tightly controlled over time. Also, they exert temporal controls over many fundamental physiological activities. This helps in coordinating the body’s internal time with the external environments. The mammalian circadian clockwork is composed of a hierarchy of oscillators, which play roles at molecular, cellular, and higher levels. The master oscillation has been found to be developed at the hypothalamic suprachiasmatic nucleus in the brain. It acts as the core pacemaker and drives the transmission of the oscillation signals. These signals are distributed across different peripheral tissues through humoral and neural connections. The synchronization among the master oscillator and tissue-specific oscillators offer overall temporal stability to mammals. Recent technological advancements help us to study the circadian rhythms at dynamic scale and systems level. Here, we outline the current understanding of circadian clockwork in terms of molecular mechanisms and interdisciplinary concepts. We have also focused on the importance of the integrative approach to decode several crucial intricacies. This review indicates the emergence of such a comprehensive approach. It will essentially accelerate the circadian research with more innovative strategies, such as developing evidence-based chronotherapeutics to restore de-synchronized circadian rhythms.

THE ROLE OF CIRCADIAN REGULATION OF GHRELIN LEVELS IN PARKINSON’S DISEASE (LITERATURE REVIEW)

2021 ◽  
Vol 74 (7) ◽  
pp. 1750-1753
Author(s):  
Kateryna A. Tarianyk ◽  
Nataliya V. Lytvynenko ◽  
Anastasiia D. Shkodina ◽  
Igor P. Kaidashev
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Clock Genes ◽  
Biological Rhythms ◽  
Circadian Regulation ◽  
Diurnal Changes ◽  
Dopaminergic Therapy ◽  
Peripheral Oscillators ◽  
Genes Expression

The paper is aimed at the analysis of the role of the circadian regulation of ghrelin levels in patients with Parkinson’s disease. Based on the literature data, patients with Parkinson’s disease have clinical fluctuations in the symptoms of the disease, manifested by the diurnal changes in motor activity, autonomic functions, sleep-wake cycle, visual function, and the efficacy of dopaminergic therapy. Biological rhythms are controlled by central and peripheral oscillators which links with dopaminergic neurotransmission – core of the pathogenesis of Parkinson`s disease. Circadian system is altered in Parkinson`s disease due to that ghrelin fluctuations may be changed. Ghrelin is potential food-entrainable oscillator because it is linked with clock genes expression. In Parkinson`s disease this hormone may induce eating behavior changing and as a result metabolic disorder. The “hunger hormone” ghrelin can be a biomarker of the Parkinson’s disease, and the study of its role in the pathogenesis, as well as its dependence on the period of the day, intake of levodopa medications to improve the effectiveness of treatment is promising.

scholarly journals Effects of Melatonin on Peripheral Reproductive Function: Regulation of Testicular GnIH and Testosterone

Endocrinology ◽  
2011 ◽  
Vol 152 (9) ◽  
pp. 3461-3470 ◽  
Author(s):  
Nicolette L. McGuire ◽  
Kristina Kangas ◽  
George E. Bentley
Keyword(s):  
Expression Patterns ◽  
Reproductive Function ◽  
Melatonin Receptors ◽  
Sex Steroid ◽  
European Starlings ◽  
Steroid Secretion ◽  
Local Inhibition ◽  
Gonadotropin Inhibitory Hormone ◽  
The Brain

Study of seasonal reproduction has focused on the brain. Here, we show that the inhibition of sex steroid secretion can be seasonally mediated at the level of the gonad. We investigate the direct effects of melatonin on sex steroid secretion and gonadal neuropeptide expression in European starlings (Sturnus vulgaris). PCR reveals starling gonads express mRNA for gonadotropin inhibitory hormone (GnIH) and its receptor (GnIHR) and melatonin receptors 1B (Mel 1B) and 1C (Mel 1C). We demonstrate that the gonadal GnIH system is regulated seasonally, possibly via a mechanism involving melatonin. GnIH/ GnIHR expression in the testes is relatively low during breeding compared with outside the breeding season. The expression patterns of Mel 1B and Mel 1C are correlated with this expression, and melatonin up-regulates the expression of GnIH mRNA in starling gonads before breeding. In vitro, GnIH and melatonin significantly decrease testosterone secretion from LH/FSH-stimulated testes before, but not during, breeding. Thus local inhibition of sex steroid secretion appears to be regulated seasonally at the level of the gonad, by a mechanism involving melatonin and the gonadal GnIH system.

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