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 Circadian clock regulation of skeletal muscle growth and repair

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 1549 ◽  
Author(s):  
Somik Chatterjee ◽  
Ke Ma
Keyword(s):  
Skeletal Muscle ◽  
Circadian Clock ◽  
Muscle Growth ◽  
Muscle Metabolism ◽  
Muscle Physiology ◽  
Skeletal Muscle Growth ◽  
Age Related ◽  
Evolutionarily Conserved ◽  
Key Aspects ◽  
And Function

Accumulating evidence indicates that the circadian clock, a transcriptional/translational feedback circuit that generates ~24-hour oscillations in behavior and physiology, is a key temporal regulatory mechanism involved in many important aspects of muscle physiology. Given the clock as an evolutionarily-conserved time-keeping mechanism that synchronizes internal physiology to environmental cues, locomotor activities initiated by skeletal muscle enable entrainment to the light-dark cycles on earth, thus ensuring organismal survival and fitness. Despite the current understanding of the role of molecular clock in preventing age-related sarcopenia, investigations into the underlying molecular pathways that transmit clock signals to the maintenance of skeletal muscle growth and function are only emerging. In the current review, the importance of the muscle clock in maintaining muscle mass during development, repair and aging, together with its contribution to muscle metabolism, will be discussed. Based on our current understandings of how tissue-intrinsic muscle clock functions in the key aspects muscle physiology, interventions targeting the myogenic-modulatory activities of the clock circuit may offer new avenues for prevention and treatment of muscular diseases. Studies of mechanisms underlying circadian clock function and regulation in skeletal muscle warrant continued efforts.

scholarly journals PSIX-29 JAK2-STAT3 Pathway Mediated Satellite Cell Apoptosis to Govern Skeletal Muscle Growth with Lysine

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 334-334
Author(s):  
Zhi-wen Song ◽  
Cheng-long Jin ◽  
Mao Ye ◽  
Chun-qi Gao ◽  
Hui-chao Yan ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Growth ◽  
Longissimus Dorsi ◽  
Control Group ◽  
Stat3 Pathway ◽  
Skeletal Muscle Growth ◽  
Longissimus Dorsi Muscle ◽  
Dorsi Muscle ◽  
Pathway Inhibition ◽  
Induced Apoptosis

Abstract Apoptosis is programmed cell death that can be stimulated by external stress or nutrition restrictions. Lysine (Lys) is an essential amino acid for pig growth, and the relationship between Lys deficiency caused apoptosis and inhibition of skeletal muscle growth remains unknown. The objective of this study was to investigate whether apoptosis could be regulated by Lys supplementation and the potential mechanism. In current work, 30 male Duroc × Landrace × Large weaned piglets were divided randomly into 3 groups: control group (Lys 1.30%), Lys deficiency group (Lys 0.86%), and Lys rescue group (Lys 0.86%, 0-14d; 1.30%,15–28 d). The experiment lasted for 28 days, and on the morning of 29 d, piglets were slaughtered to collect samples. Isobaric tag for relative and absolute quantification (iTRAQ) proteomics analysis of the longissimus dorsi muscle showed that Janus family tyrosine kinase (JAK)-signal transducer and activator of transcription (STAT) pathway was involved in Lys deficiency-induced apoptosis and inhibited skeletal muscle growth. Meanwhile, western blotting results of the longissimus dorsi muscle demonstrated that Lys deficiency caused apoptosis (P < 0.05) with the JAK2-STAT3 pathway inhibition (P < 0.05). Interestingly, apoptosis was suppressed (P < 0.05), and the JAK2-STAT3 pathway was reactivated (P < 0.05) after Lys re-supplementation in longissimus dorsi muscle. In addition, results of satellite cells (SCs) isolated from the longissimus dorsi muscle of 5-day-old Landrace piglets showed that Lys deficiency-induced apoptosis (P < 0.05) was mediated by the JAK2-STAT3 pathway inhibition (P < 0.05). Moreover, the JAK2-STAT3 pathway was reactivated (P < 0.05) by Lys re-supplementation and suppressed apoptosis in SCs (P < 0.05), and this effect was blocked (P < 0.05) after SCs treated with AG-490 (a specific inhibitor of JAK2). Collectively, Lys inhibited apoptosis in SCs to govern skeletal muscle growth via the JAK2-STAT3 pathway.

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.

Anemic Hypoxemia Reduces Myoblast Proliferation and Muscle Growth in Late Gestation Fetal Sheep

2021 ◽  
Author(s):  
Paul J. Rozance ◽  
Stephanie R Wesolowski ◽  
Sonnet S. Jonker ◽  
Laura D Brown
Keyword(s):  
Skeletal Muscle ◽  
Mrna Expression ◽  
Muscle Growth ◽  
Late Gestation ◽  
Whole Body ◽  
Myoblast Differentiation ◽  
Fetal Sheep ◽  
Body Protein ◽  
Skeletal Muscle Growth ◽  
Myoblast Proliferation

Fetal skeletal muscle growth requires myoblast proliferation, differentiation, and fusion into myofibers in addition to protein accretion for fiber hypertrophy. Oxygen is an important regulator of this process. Therefore, we hypothesized that fetal anemic hypoxemia would inhibit skeletal muscle growth. Studies were performed in late gestation fetal sheep that were bled to anemic, and therefore hypoxemic, conditions beginning at ~125 days of gestation (term = 148 days) for 9 ± 0 days (n=19) and compared to control fetuses (n=16). A metabolic study was performed on gestational day ~134 to measure fetal protein kinetic rates. Myoblast proliferation and myofiber area were determined in biceps femoris (BF), tibialis anterior (TA), and flexor digitorum superficialis (FDS) muscles. mRNA expression of muscle regulatory factors was determined in BF. Fetal arterial hematocrit and oxygen content were 28% and 52% lower, respectively, in anemic fetuses. Fetal weight and whole-body protein synthesis, breakdown, and accretion rates were not different between groups. Hindlimb length, however, was 7% shorter in anemic fetuses. TA and FDS muscles weighed less and FDS myofiber area was smaller in anemic fetuses compared to controls. The percentage of Pax7+ myoblasts that expressed Ki67 was lower in BF and tended to be lower in FDS from anemic fetuses indicating reduced myoblast proliferation. There was less MYOD and MYF6 mRNA expression in anemic vs. control BF consistent with reduced myoblast differentiation. These results indicate that fetal anemic hypoxemia reduced muscle growth. We speculate that fetal muscle growth may be improved by strategies that increase oxygen availability.

Systematic transcriptome-wide analysis of mRNA–miRNA interactions reveals the involvement of miR-142-5p and its target (FOXO3) in skeletal muscle growth in chickens

2017 ◽  
Vol 293 (1) ◽  
pp. 69-80 ◽  
Author(s):  
Zhenhui Li ◽  
Bahareldin Ali Abdalla ◽  
Ming Zheng ◽  
Xiaomei He ◽  
Bolin Cai ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Growth ◽  
Skeletal Muscle Growth

scholarly journals Prepubertal skeletal muscle growth requires Pax7-expressing satellite cell-derived myonuclear contribution

Development ◽  
2018 ◽  
Vol 145 (20) ◽  
pp. dev167197 ◽  
Author(s):  
John F. Bachman ◽  
Alanna Klose ◽  
Wenxuan Liu ◽  
Nicole D. Paris ◽  
Roméo S. Blanc ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Satellite Cell ◽  
Muscle Growth ◽  
Skeletal Muscle Growth
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