scholarly journals The Role of the Molecular Clock in Promoting Skeletal Muscle Growth and Protecting against Sarcopenia

2019 ◽  
Vol 20 (17) ◽  
pp. 4318 ◽  
Author(s):  
Jacopo Vitale ◽  
Matteo Bonato ◽  
Antonio La Torre ◽  
Giuseppe Banfi
Keyword(s):  
Skeletal Muscle ◽  
Circadian Rhythms ◽  
Molecular Clock ◽  
Current Knowledge ◽  
Critical Role ◽  
Muscle Growth ◽  
Circadian Expression ◽  
Complex Interactions ◽  
Underlying Mechanisms ◽  
And Function

The circadian clock has a critical role in many physiological functions of skeletal muscle and is essential to fully understand the precise underlying mechanisms involved in these complex interactions. The importance of circadian expression for structure, function and metabolism of skeletal muscle is clear when observing the muscle phenotype in models of molecular clock disruption. Presently, the maintenance of circadian rhythms is emerging as an important new factor in human health, with disruptions linked to ageing, as well as to the development of many chronic diseases, including sarcopenia. Therefore, the aim of this review is to present the latest findings demonstrating how circadian rhythms in skeletal muscle are important for maintenance of the cellular physiology, metabolism and function of skeletal muscle. Moreover, we will present the current knowledge about the tissue-specific functions of the molecular clock in skeletal muscle.

scholarly journals Alterations in intestinal microbiota diversity, composition, and function in patients with sarcopenia

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lin Kang ◽  
Pengtao Li ◽  
Danyang Wang ◽  
Taihao Wang ◽  
Dong Hao ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
16S Rrna ◽  
Intestinal Microbiota ◽  
Muscle Growth ◽  
Growth Function ◽  
16S Rrna Sequencing ◽  
Fecal Samples ◽  
Lipopolysaccharide Biosynthesis ◽  
Rrna Sequencing ◽  
And Function

Abstract16S rRNA sequencing of human fecal samples has been tremendously successful in identifying microbiome changes associated with both aging and disease. A number of studies have described microbial alterations corresponding to physical frailty and nursing home residence among aging individuals. A gut-muscle axis through which the microbiome influences skeletal muscle growth/function has been hypothesized. However, the microbiome has yet to be examined in sarcopenia. Here, we collected fecal samples of 60 healthy controls (CON) and 27 sarcopenic (Case)/possibly sarcopenic (preCase) individuals and analyzed the intestinal microbiota using 16S rRNA sequencing. We observed an overall reduction in microbial diversity in Case and preCase samples. The genera Lachnospira, Fusicantenibacter, Roseburia, Eubacterium, and Lachnoclostridium—known butyrate producers—were significantly less abundant in Case and preCase subjects while Lactobacillus was more abundant. Functional pathways underrepresented in Case subjects included numerous transporters and phenylalanine, tyrosine, and tryptophan biosynthesis suggesting that protein processing and nutrient transport may be impaired. In contrast, lipopolysaccharide biosynthesis was overrepresented in Case and PreCase subjects suggesting that sarcopenia is associated with a pro-inflammatory metagenome. These analyses demonstrate structural and functional alterations in the intestinal microbiota that may contribute to loss of skeletal muscle mass and function in sarcopenia.

SALT/WATER RELATIONSHIPS IN MANGROVES

1999 ◽  
Vol 47 (2) ◽  
pp. 63-76 ◽  
Author(s):  
Nobutaka Hanagata ◽  
Taro Takemura ◽  
Isao Karube ◽  
Zvy Dubinsky
Keyword(s):  
Current Knowledge ◽  
Salt Water ◽  
Compatible Solutes ◽  
Oscillatory Behavior ◽  
Salt Glands ◽  
Seawater Salinity ◽  
Anaerobic Soils ◽  
Aerial Roots ◽  
Underlying Mechanisms ◽  
And Function

Mangroves form extensive, unique communities in tropical coastal areas and tidal lowlands, dominating 60–75% of tropical shorelines. The aim of the present review is to summarize the current knowledge concerning the mechanisms underlying the most striking feature of these plants—their unique ability to obtain water from the surrounding sea. Mangroves are thought to accomplish this by rejecting potentially harmful salts. Some species actively excrete those salts leaking into the plant by means of specialized salt glands in their leaves. Mangroves are rooted in anaerobic soils, a condition giving rise to the spectacular aerial roots, such as pneumatophores and stilt roots, characteristic of mangroves, that provide oxygen to submerged tissues.We shall also discuss recent studies that have focused on physiological issues in mangroves, such as oscillatory behavior of their stomata, the structure and function of salt glands, and the compatible solutes in their leaves, which balance the osmotic pressure of the seawater. Salinity effects on their germination, distribution, CO2assimilation, respiration, and the functioning of some of their enzymes have also been examined.Finally, we shall draw attention to open questions related to the salt and water regime of mangroves and the underlying mechanisms responsible for their remarkable success in a hostile environment.

scholarly journals Re-Setting the Circadian Clock Using Exercise against Sarcopenia

2020 ◽  
Vol 21 (9) ◽  
pp. 3106 ◽  
Author(s):  
Youngju Choi ◽  
Jinkyung Cho ◽  
Mi-Hyun No ◽  
Jun-Won Heo ◽  
Eun-Jeong Cho ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Circadian Rhythms ◽  
Circadian Clock ◽  
Intervention Strategy ◽  
Muscle Metabolism ◽  
Circadian Disruption ◽  
Adverse Health Outcomes ◽  
Exercise Timing ◽  
Underlying Mechanisms ◽  
The Impact

Sarcopenia is defined as the involuntary loss of skeletal muscle mass and function with aging and is associated with several adverse health outcomes. Recently, the disruption of regular circadian rhythms, due to shift work or nocturnal lifestyle, is emerging as a novel deleterious factor for the development of sarcopenia. The underlying mechanisms responsible for circadian disruption-induced sarcopenia include molecular circadian clock and mitochondrial function associated with the regulation of circadian rhythms. Exercise is a potent modulator of skeletal muscle metabolism and is considered to be a crucial preventative and therapeutic intervention strategy for sarcopenia. Moreover, emerging evidence shows that exercise, acting as a zeitgeber (time cue) of the skeletal muscle clock, can be an efficacious tool for re-setting the clock in sarcopenia. In this review, we provide the evidence of the impact of circadian disruption on skeletal muscle loss resulting in sarcopenia. Furthermore, we highlight the importance of exercise timing (i.e., scheduled physical activity) as a novel therapeutic strategy to target circadian disruption in skeletal muscle.

scholarly journals HDAC4 Regulates the Proliferation, Differentiation and Apoptosis of Chicken Skeletal Muscle Satellite Cells

Animals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 84 ◽  
Author(s):  
Jing Zhao ◽  
Xiaoxu Shen ◽  
Xinao Cao ◽  
Haorong He ◽  
Shunshun Han ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Satellite Cells ◽  
Muscle Development ◽  
Critical Role ◽  
Muscle Growth ◽  
Positive Role ◽  
Muscle Satellite Cells ◽  
Skeletal Muscle Satellite Cells ◽  
Chicken Skeletal Muscle

The development of skeletal muscle satellite cells (SMSCs) is a complex process that could be regulated by many genes. Previous studies have shown that Histone Deacetylase 4 (HDAC4) plays a critical role in cell proliferation, differentiation, and apoptosis in mouse. However, the function of HDAC4 in chicken muscle development is still unknown. Given that chicken is a very important meat-producing animal that is also an ideal model to study skeletal muscle development, we explored the functions of HDAC4 in chicken SMSCs after the interference of HDAC4. The results showed that HDAC4 was enriched in embryonic skeletal muscle, and it was highly expressed in embryonic muscle than in postnatal muscles. Meanwhile, knockdown of HDAC4 could significantly inhibit the proliferation and differentiation of chicken SMSCs but had no effect on the apoptosis of SMSCs as observed in a series of experiment conducted in vitro. These results indicated that HDAC4 might play a positive role in chicken skeletal muscle growth and development.

scholarly journals The critical role of Krüppel-like factors in kidney disease

2017 ◽  
Vol 312 (2) ◽  
pp. F259-F265 ◽  
Author(s):  
Sandeep K. Mallipattu ◽  
Chelsea C. Estrada ◽  
John C. He
Keyword(s):  
Current Knowledge ◽  
Critical Role ◽  
Vital Role ◽  
Glomerular Filtration Barrier ◽  
Kidney Fibrosis ◽  
Physiological Processes ◽  
Filtration Barrier ◽  
And Function ◽  
Mammalian Embryonic Development

Krüppel-like factors (KLFs) are a family of zinc-finger transcription factors critical to mammalian embryonic development, regeneration, and human disease. There is emerging evidence that KLFs play a vital role in key physiological processes in the kidney, ranging from maintenance of glomerular filtration barrier to tubulointerstitial inflammation to progression of kidney fibrosis. Seventeen members of the KLF family have been identified, and several have been well characterized in the kidney. Although they may share some overlap in their downstream targets, their structure and function remain distinct. This review highlights our current knowledge of KLFs in the kidney, which includes their pattern of expression and their function in regulating key biological processes. We will also critically examine the currently available literature on KLFs in the kidney and offer some key areas in need of further investigation.

scholarly journals 56. Investigation of androgen action in skeletal muscle growth and function

2003 ◽  
Vol 15 (9) ◽  
pp. 56
Author(s):  
A. Axell ◽  
H. E. MacLean ◽  
D. Plant ◽  
M. Jimenez ◽  
D. J. Handelsman ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Growth ◽  
Skeletal Muscle Growth ◽  
Androgen Action ◽  
And Function

scholarly journals The role of neuregulin/ErbB2/ErbB4 signaling in the heart with special focus on effects on cardiomyocyte proliferation

2012 ◽  
Vol 302 (11) ◽  
pp. H2139-H2147 ◽  
Author(s):  
Brian Wadugu ◽  
Bernhard Kühn
Keyword(s):  
Heart Failure ◽  
Cardiac Development ◽  
Current Knowledge ◽  
Critical Role ◽  
Special Focus ◽  
Cardiomyocyte Proliferation ◽  
Neuregulin 1 ◽  
Adult Heart ◽  
Signaling Complex ◽  
And Function

The signaling complex consisting of the growth factor neuregulin-1 (NRG1) and its tyrosine kinase receptors ErbB2 and ErbB4 has a critical role in cardiac development and homeostasis of the structure and function of the adult heart. Recent research results suggest that targeting this signaling complex may provide a viable strategy for treating heart failure. Clinical trials are currently evaluating the effectiveness and safety of intravenous administration of recombinant NRG1 formulations in heart failure patients. Endogenous as well as administered NRG1 has multiple possible activities in the adult heart, but how these are related is unknown. It has recently been demonstrated that NRG1 administration can stimulate proliferation of cardiomyocytes, which may contribute to repair failing hearts. This review summarizes the current knowledge of how NRG1 and its receptors control cardiac physiology and biology, with special emphasis on its role in cardiomyocyte proliferation during myocardial growth and regeneration.

scholarly journals Revisiting the Teleost Thymus: Current Knowledge and Future Perspectives

Biology ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 8
Author(s):  
Felipe Barraza ◽  
Ruth Montero ◽  
Valentina Wong-Benito ◽  
Héctor Valenzuela ◽  
Carlos Godoy-Guzmán ◽  
...  
Keyword(s):  
Current Knowledge ◽  
Critical Role ◽  
Temperature Fluctuations ◽  
Cartilaginous Fish ◽  
Cell Distribution ◽  
Teleost Fishes ◽  
Future Perspectives ◽  
Thymus Cell ◽  
Thymus Development ◽  
And Function

The thymus in vertebrates plays a critical role in producing functionally competent T-lymphocytes. Phylogenetically, the thymus emerges early during evolution in jawed cartilaginous fish, and it is usually a bilateral organ placed subcutaneously at the dorsal commissure of the operculum. In this review, we summarize the current understanding of the thymus localization, histology studies, cell composition, and function in teleost fishes. Furthermore, we consider environmental factors that affect thymus development, such as seasonal changes, photoperiod, water temperature fluctuations and hormones. Further analysis of the thymus cell distribution and function will help us understand how key stages for developing functional T cells occur in fish, and how thymus dynamics can be modulated by external factors like photoperiod. Overall, the information presented here helps identify the knowledge gaps and future steps needed for a better understanding of the immunobiology of fish thymus.

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