scholarly journals Chemoradiation impairs myofiber hypertrophic growth in a pediatric tumor model

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Nicole D. Paris ◽  
Jacob G. Kallenbach ◽  
John F. Bachman ◽  
Roméo S. Blanc ◽  
Carl J. Johnston ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Cancer Treatment ◽  
Pediatric Cancer ◽  
Muscle Growth ◽  
Small Animal ◽  
Tumor Model ◽  
Preclinical Model ◽  
Pediatric Tumor ◽  
Hypertrophic Growth ◽  
Myonuclear Domain

Abstract Pediatric cancer treatment often involves chemotherapy and radiation, where off-target effects can include skeletal muscle decline. The effect of such treatments on juvenile skeletal muscle growth has yet to be investigated. We employed a small animal irradiator to administer fractionated hindlimb irradiation to juvenile mice bearing implanted rhabdomyosarcoma (RMS) tumors. Hindlimb-targeted irradiation (3 × 8.2 Gy) of 4-week-old mice successfully eliminated RMS tumors implanted one week prior. After establishment of this preclinical model, a cohort of tumor-bearing mice were injected with the chemotherapeutic drug, vincristine, alone or in combination with fractionated irradiation (5 × 4.8 Gy). Single myofiber analysis of fast-contracting extensor digitorum longus (EDL) and slow-contracting soleus (SOL) muscles was conducted 3 weeks post-treatment. Although a reduction in myofiber size was apparent, EDL and SOL myonuclear number were differentially affected by juvenile irradiation and/or vincristine treatment. In contrast, a decrease in myonuclear domain (myofiber volume/myonucleus) was observed regardless of muscle or treatment. Thus, inhibition of myofiber hypertrophic growth is a consistent feature of pediatric cancer treatment.

The effect of the anabolic agent, clenbuterol, on overloaded rat skeletal muscle

1987 ◽  
Vol 7 (2) ◽  
pp. 143-149 ◽  
Author(s):  
C. A. Maltin ◽  
M. I. Delday ◽  
S. M. Hay ◽  
F. G. Smith ◽  
G. E. Lobley ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Drug Treatment ◽  
Growth Response ◽  
Muscle Growth ◽  
Young Male ◽  
Male Rats ◽  
Rat Skeletal Muscle ◽  
Anabolic Agent ◽  
Hypertrophic Growth ◽  
Fibre Size

The dietary administration of clenbuterol to young male rats has been shown to produce a muscle specific hypertrophic growth response. This paper demonstrates that the combined effect of drug treatment and hypertrophic stimulus induced by tenotomy produced an additive effect on muscle growth. This effect was demonstrated in terms of both muscle composition (protein and RNA) and fibre size.

scholarly journals Proteomic profile and morphological characteristics of skeletal muscle from the fast- and slow-growing yellow perch (Perca flavescens)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Karolina Kwasek ◽  
Young Min Choi ◽  
Hanping Wang ◽  
Kichoon Lee ◽  
John Mark Reddish ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Yellow Perch ◽  
Glycogen Phosphorylase ◽  
Expression Patterns ◽  
Muscle Growth ◽  
Perca Flavescens ◽  
Morphological Characteristics ◽  
Gene Products ◽  
Hypertrophic Growth ◽  
Slow Growing

AbstractThe objective of the present study was to compare skeletal muscle proteomic profiles, histochemical characteristics, and expression levels of myogenic regulatory factors (MRFs) between fast- versus slow-growing yellow perch Perca flavescens and identify the proteins/peptides that might play a crucial role in the muscle growth dynamic. Yellow perch were nursed in ponds for 6 weeks from larval stage and cultured in two meter diameter tanks thereafter. The fingerlings were graded to select the top 10% and bottom 10% fish which represented fast- and slow-growing groups (31 yellow perch per each group). Our statistical analyses showed 18 proteins that had different staining intensities between fast- and slow-growing yellow perch. From those proteins 10 showed higher expression in slow-growers, and 8 demonstrated higher expression in fast-growers. Fast-growing yellow perch with a greater body weight was influenced by both the muscle fiber hypertrophy and mosaic hyperplasia compared to slow-growing fish. These hyperplastic and hypertrophic growth in fast-grower were associated with not only metabolic enzymes, including creatine kinase, glycogen phosphorylase, and aldolase, but also myoD and myogenin as MRFs. Overall, the results of the present study contribute to the identification of different expression patterns of gene products in fast- and slow-growing fish associated with their muscle growth.

scholarly journals The m6A methyltransferase METTL3 regulates muscle maintenance and growth in mice

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Jennifer M. Petrosino ◽  
Scott A. Hinger ◽  
Volha A. Golubeva ◽  
Juan M. Barajas ◽  
Lisa E. Dorn ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Growth ◽  
Muscle Size ◽  
Hypertrophic Response ◽  
Hypertrophic Growth ◽  
Genome Wide ◽  
Muscle Proteome ◽  
Exogenous Delivery ◽  
Muscle Homeostasis

AbstractSkeletal muscle serves fundamental roles in organismal health. Gene expression fluctuations are critical for muscle homeostasis and the response to environmental insults. Yet, little is known about post-transcriptional mechanisms regulating such fluctuations while impacting muscle proteome. Here we report genome-wide analysis of mRNA methyladenosine (m6A) dynamics of skeletal muscle hypertrophic growth following overload-induced stress. We show that increases in METTL3 (the m6A enzyme), and concomitantly m6A, control skeletal muscle size during hypertrophy; exogenous delivery of METTL3 induces skeletal muscle growth, even without external triggers. We also show that METTL3 represses activin type 2 A receptors (ACVR2A) synthesis, blunting activation of anti-hypertrophic signaling. Notably, myofiber-specific conditional genetic deletion of METTL3 caused spontaneous muscle wasting over time and abrogated overload-induced hypertrophy; a phenotype reverted by co-administration of a myostatin inhibitor. These studies identify a previously unrecognized post-transcriptional mechanism promoting the hypertrophic response of skeletal muscle via control of myostatin signaling.

scholarly journals Depletion of resident muscle stem cells inhibits muscle fiber hypertrophy induced by lifelong physical activity

2019 ◽  
Author(s):  
Davis A. Englund ◽  
Kevin A. Murach ◽  
Cory M. Dungan ◽  
Vandré C. Figueiredo ◽  
Ivan J. Vechetti ◽  
...  
Keyword(s):  
Physical Activity ◽  
Skeletal Muscle ◽  
Physical Function ◽  
Satellite Cell ◽  
Muscle Fiber ◽  
Satellite Cells ◽  
Muscle Growth ◽  
Free Access ◽  
Running Wheel ◽  
Hypertrophic Growth

AbstractBackgroundA reduction in skeletal muscle stem cell (satellite cell) content with advancing age is thought to directly contribute to the progressive loss of skeletal muscle mass and function with aging (sarcopenia). However, we reported that the depletion of satellite cells throughout adulthood did not affect the onset or degree of sarcopenia observed in sedentary old mice. The current study was designed to determine if lifelong physical activity would alter the requirements for satellite cells during aging.MethodsWe administered vehicle or tamoxifen to adult (5 months old) female Pax7-DTA mice for 5 consecutive days to effectively deplete satellite cells. Following a 2-month washout period, mice were assigned to physically active (free access to a running wheel) or sedentary (locked running wheel) conditions. Thirteen months later, at a mean age of 20 months, mice were sacrificed for subsequent analysis.ResultsSatellite cell depletion throughout adulthood negatively impacted physical function and limited muscle fiber hypertrophy in response to lifelong physical activity. To further interrogate these findings, we performed transcriptome-wide analyses on the hind limb muscles that experienced hypertrophic growth (plantaris and soleus) in response to lifelong physical activity. Our findings demonstrate that satellite cell function is muscle type-specific; fusion with fibers is apparent in oxidative muscles, while initiation of Gαi2 signaling appears to require satellite cells in glycolytic muscles to induce muscle growth..ConclusionsThese findings suggest that satellite cells, or their secretory products, are viable therapeutic targets to preserve physical function with aging and promote muscle growth in older adults who regularly engage in physical activity.

Cutaneous reactions to pediatric cancer treatment part II: Targeted therapy

2020 ◽  
Author(s):  
Valerie M. Carlberg ◽  
Olivia M. T. Davies ◽  
Heather A. Brandling‐Bennett ◽  
Sarah E. S. Leary ◽  
Jennifer T. Huang ◽  
...  
Keyword(s):  
Targeted Therapy ◽  
Cancer Treatment ◽  
Pediatric Cancer ◽  
Cutaneous Reactions

scholarly journals Key Genes Regulating Skeletal Muscle Development and Growth in Farm Animals

Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 835
Author(s):  
Mohammadreza Mohammadabadi ◽  
Farhad Bordbar ◽  
Just Jensen ◽  
Min Du ◽  
Wei Guo
Keyword(s):  
Skeletal Muscle ◽  
Candidate Genes ◽  
Meat Quality ◽  
Muscle Development ◽  
Muscle Growth ◽  
Farm Animals ◽  
Meat Production ◽  
Skeletal Muscle Development ◽  
Extrinsic Factors ◽  
Myogenic Regulatory Factor

Farm-animal species play crucial roles in satisfying demands for meat on a global scale, and they are genetically being developed to enhance the efficiency of meat production. In particular, one of the important breeders’ aims is to increase skeletal muscle growth in farm animals. The enhancement of muscle development and growth is crucial to meet consumers’ demands regarding meat quality. Fetal skeletal muscle development involves myogenesis (with myoblast proliferation, differentiation, and fusion), fibrogenesis, and adipogenesis. Typically, myogenesis is regulated by a convoluted network of intrinsic and extrinsic factors monitored by myogenic regulatory factor genes in two or three phases, as well as genes that code for kinases. Marker-assisted selection relies on candidate genes related positively or negatively to muscle development and can be a strong supplement to classical selection strategies in farm animals. This comprehensive review covers important (candidate) genes that regulate muscle development and growth in farm animals (cattle, sheep, chicken, and pig). The identification of these genes is an important step toward the goal of increasing meat yields and improves meat quality.

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.

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