Mechanical loading of tissue engineered skeletal muscle prevents dexamethasone induced myotube atrophy

Abstract Skeletal muscle atrophy as a consequence of acute and chronic illness, immobilisation, muscular dystrophies and aging, leads to severe muscle weakness, inactivity and increased mortality. Mechanical loading is thought to be the primary driver for skeletal muscle hypertrophy, however the extent to which mechanical loading can offset muscle catabolism has not been thoroughly explored. In vitro 3D-models of skeletal muscle provide a controllable, high throughput environment and mitigating many of the ethical and methodological constraints present during in vivo experimentation. This work aimed to determine if mechanical loading would offset dexamethasone (DEX) induced skeletal muscle atrophy, in muscle engineered using the C2C12 murine cell line. Mechanical loading successfully offset myotube atrophy and functional degeneration associated with DEX regardless of whether the loading occurred before or after 24 h of DEX treatment. Furthermore, mechanical load prevented increases in MuRF-1 and MAFbx mRNA expression, critical regulators of muscle atrophy. Overall, we demonstrate the application of tissue engineered muscle to study skeletal muscle health and disease, offering great potential for future use to better understand treatment modalities for skeletal muscle atrophy.

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Camphene Attenuates Skeletal Muscle Atrophy by Regulating Oxidative Stress and Lipid Metabolism in Rats

Nutrients ◽

10.3390/nu12123731 ◽

2020 ◽

Vol 12 (12) ◽

pp. 3731

Author(s):

Suji Baek ◽

Jisu Kim ◽

Byung Seok Moon ◽

Sun Mi Park ◽

Da Eun Jung ◽

...

Keyword(s):

Oxidative Stress ◽

Skeletal Muscle ◽

Lipid Metabolism ◽

Muscle Atrophy ◽

Gas Analysis ◽

Skeletal Muscle Atrophy ◽

Ros Scavenging ◽

In Vivo Models

Sarcopenia- or cachexia-related muscle atrophy is due to imbalanced energy metabolism and oxidative stress-induced muscle dysfunction. Monoterpenes play biological and pharmacological reactive oxygen species (ROS) scavenging roles. Hence, we explored the effects of camphene, a bicyclic monoterpene, on skeletal muscle atrophy in vitro and in vivo. We treated L6 myoblast cells with camphene and then examined the ROS-related oxidative stress using Mito TrackerTM Red FM and anti-8-oxoguanine antibody staining. To investigate lipid metabolism, we performed real-time polymerase chain reactions, holotomographic microscopy, and respiratory gas analysis. Rat muscle atrophy in in vivo models was observed using 18F-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography and immunocytochemistry. Camphene reversed the aberrant cell size and muscle morphology of L6 myoblasts under starvation and in in vivo models. Camphene also attenuated E3 ubiquitin ligase muscle RING-finger protein-1, mitochondrial fission, and 8-oxoguanine nuclear expression in starved myotubes and hydrogen peroxide (H2O2)-treated cells. Moreover, camphene significantly regulated lipid metabolism in H2O2-treated cells and in vivo models. These findings suggest that camphene may potentially affect skeletal muscle atrophy by regulating oxidative stress and lipid metabolism.

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Trimetazidine Attenuates Dexamethasone-Induced Muscle Atrophy via Inhibiting NLRP3/GSDMD Pathway-Mediated Pyroptosis

10.20944/preprints202012.0643.v1 ◽

2020 ◽

Author(s):

Li Wang ◽

Ming-Qing He ◽

Xi-Yu Shen ◽

Kang-Zhen Zhang ◽

Can Zhao ◽

...

Keyword(s):

Skeletal Muscle ◽

Muscle Atrophy ◽

Ring Finger ◽

Muscle Performance ◽

Skeletal Muscle Atrophy ◽

C2c12 Myotubes ◽

High Dose ◽

Therapeutic Compound

Skeletal muscle atrophy is one of the major side effects of high dose or sustained usage of glucocorticoids. Pyroptosis is a novel form of pro-inflammatory programmed cell death that may contribute to skeletal muscle injury. Trimetazidine, a well-known anti-anginal agent, can also improve skeletal muscle performance both in human and mice. We here showed that dexamethasone induced atrophy, evidenced by the increase of muscle atrophy F-box (Atrogin-1) and muscle ring finger 1 (MuRF1) expression , and the decrease of myotube diameter in C2C12 myotubes. Dexamethasone also induced pyroptosis, indicated by upregulated pyroptosis-related protein NLRP3, Caspase-1 and GSDMD. Knockdown of NLRP3 or GSDMD attenuated dexamethasone-induced myotube pyroptosis and atrophy. Trimetazidine administration ameliorated dexamethasone-induced muscle atrophy both in vivo and in vitro. Moreover, trimetazidine improved exercise tolerance, as evidenced by increased running distance and running time, as well as increased skeletal muscle mass in dexamethasone-treated mice. Mechanically, trimetazidine could reverse dexamethasone-induced activation of pyroptosis both in C2C12 myotubes and in mice. Taken together, our present study demonstrated that NLRP3/GSDMD pathway-mediated pyroptosis was involved in dexamethasone-induced skeletal muscle atrophy. Trimetazidine could partially alleviate dexamethasone-induced skeletal muscle atrophy, and increase the diameter of C2C12 myotubes via inhibiting pyroptosis. Thus, trimetazidine might be a potential therapeutic compound for the prevention of muscle atrophy in glucocorticoid-treated patients.

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Blockade of Metallothioneins 1 and 2 Increases Skeletal Muscle Mass and Strength

Molecular and Cellular Biology ◽

10.1128/mcb.00305-16 ◽

2016 ◽

Vol 37 (5) ◽

Cited By ~ 25

Author(s):

Serge Summermatter ◽

Anais Bouzan ◽

Eliane Pierrel ◽

Stefan Melly ◽

Daniela Stauffer ◽

...

Keyword(s):

Skeletal Muscle ◽

Muscle Mass ◽

Muscle Atrophy ◽

Skeletal Muscle Atrophy ◽

Intracellular Zinc ◽

Beneficial Effects ◽

And Function ◽

Zinc Storage

ABSTRACT Metallothioneins are proteins that are involved in intracellular zinc storage and transport. Their expression levels have been reported to be elevated in several settings of skeletal muscle atrophy. We therefore investigated the effect of metallothionein blockade on skeletal muscle anabolism in vitro and in vivo. We found that concomitant abrogation of metallothioneins 1 and 2 results in activation of the Akt pathway and increases in myotube size, in type IIb fiber hypertrophy, and ultimately in muscle strength. Importantly, the beneficial effects of metallothionein blockade on muscle mass and function was also observed in the setting of glucocorticoid addition, which is a strong atrophy-inducing stimulus. Given the blockade of atrophy and the preservation of strength in atrophy-inducing settings, these results suggest that blockade of metallothioneins 1 and 2 constitutes a promising approach for the treatment of conditions which result in muscle atrophy.

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Linalool Prevents Cisplatin Induced Muscle Atrophy by Regulating IGF-1/Akt/FoxO Pathway

Frontiers in Pharmacology ◽

10.3389/fphar.2020.598166 ◽

2020 ◽

Vol 11 ◽

Author(s):

Hong Zhang ◽

Mengyi Chi ◽

Linlin Chen ◽

Xipeng Sun ◽

Lili Wan ◽

...

Keyword(s):

Skeletal Muscle ◽

Muscle Atrophy ◽

Cancer Cachexia ◽

Ring Finger ◽

Skeletal Muscle Atrophy ◽

Lewis Lung Cancer ◽

Muscle Weight ◽

C2c12 Myotube

Skeletal muscle atrophy is an important feature of cancer cachexia, which can be induced by chemotherapy, and affects the survival and quality of life of cancer patients seriously. No specific drugs for cancer cachexia have been applied in clinical practice. This study explored the therapeutic effect of linalool (LIN) on cisplatin (DDP) induced skeletal muscle atrophy. In vivo, LIN can improve skeletal muscle weight loss, anorexia, muscle strength decline and other cachexia symptoms caused by cisplatin treatment in a Lewis lung cancer tumor bearing mouse model, and cause no adverse effects on the anti-tumour effect. LIN treatment decreased the expression of muscle RING-finger protein-1 (MuRF1) and Atrogin1(MAFbx) in muscle, and the activation of insulin-like growth factor-1 (IGF-1)/protein kinase B (Akt)/forkhead box O (FoxO) pathway was observed. In vitro, LIN alleviated DDP induced C2C12 myotube atrophy, and IGF-1 receptor inhibitor Picropodophyllin (PIC), which had no adverse effect on C2C12 myotube cells, could reverse the protective effect of LIN. These results indicate that LIN down-regulates the expression of Atrogin1 and MuRF1 through the IGF-1/Akt/FoxO pathway, alleviating DDP-induced muscle atrophy and improving cachexia symptoms. LIN has the potential to be developed as a drug against cancer cachexia.

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Mechanism of Attenuation of Skeletal Muscle Atrophy by Zinc-α2-Glycoprotein

Endocrinology ◽

10.1210/en.2010-0532 ◽

2010 ◽

Vol 151 (10) ◽

pp. 4696-4704 ◽

Cited By ~ 17

Author(s):

Steven T. Russell ◽

Michael J. Tisdale

Keyword(s):

Skeletal Muscle ◽

Muscle Atrophy ◽

Soleus Muscle ◽

Mammalian Target Of Rapamycin ◽

Ring Finger ◽

Initiation Factor ◽

Skeletal Muscle Atrophy ◽

Intracellular Camp

The mechanism by which the adipokine zinc-α2-glycoprotein (ZAG) increases the mass of gastrocnemius, but not soleus muscle of diabetic mice, has been evaluated both in vivo and in vitro. There was an increased phosphorylation of both double-stranded RNA-dependent protein kinase and its substrate, eukaryotic initiation factor-2α, which was attenuated by about two-thirds in gastrocnemius but not soleus muscle of ob/ob mice treated with ZAG (50 μg, iv daily) for 5 d. ZAG also reduced the expression of the phospho forms of p38MAPK and phospholipase A2, as well as expression of the ubiquitin ligases (E3) muscle atrophy F-box/atrogin-1 and muscle RING finger protein, and the increased activity of both caspase-3 and casapse-8 to values found in nonobese controls. ZAG also increased the levels of phospho serine-threonine kinase and mammalian target of rapamycin in gastrocnemius muscle and reduced the phosphorylation of insulin receptor substrate-1 (Ser307) associated with insulin resistance. Similar changes were seen with ZAG when murine myotubes were incubated with high glucose concentrations (10 and 25 mm), showing that the effect of ZAG was direct. ZAG produced an increase in cAMP in murine myotubes, and the effects of ZAG on protein synthesis and degradation in vitro could be replicated by dibutyryl cAMP. ZAG increased cAMP levels of gastrocnemius but not soleus muscle. These results suggest that protein accretion in skeletal muscle in response to ZAG may be due to changes in intracellular cAMP and also that ZAG may have a therapeutic application in the treatment of muscle wasting conditions.

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Antioxidant Activity of Valeriana fauriei Protects against Dexamethasone-Induced Muscle Atrophy

Oxidative Medicine and Cellular Longevity ◽

10.1155/2022/3645431 ◽

2022 ◽

Vol 2022 ◽

pp. 1-16

Author(s):

Young In Kim ◽

Hyunjung Lee ◽

Farida S. Nirmala ◽

Hyo-Deok Seo ◽

Tae Youl Ha ◽

...

Keyword(s):

Skeletal Muscle ◽

Muscle Atrophy ◽

Skeletal Muscle Atrophy ◽

High Dose ◽

Muscle Weight ◽

Cross Sectional ◽

Myosin Heavy Chain Isoform ◽

Ros Scavenger

Skeletal muscle atrophy is defined as wasting or loss of muscle. Although glucocorticoids (GCs) are well-known anti-inflammatory drugs, their long-term or high-dose use induces skeletal muscle atrophy. Valeriana fauriei (VF) is used to treat restlessness, anxiety, and sleep disorders; however, its effects on skeletal muscle health have not been investigated. This study investigated whether Valeriana fauriei could ameliorate muscle atrophy. We induced muscle atrophy in vitro and in vivo, by treatment with dexamethasone (DEX), a synthetic GC. In DEX-induced myotube atrophy, Valeriana fauriei treatment increased the fusion index and decreased the expression of muscle atrophic genes such as muscle atrophy F-box (MAFbx/Atrogin-1) and muscle RING-finger protein 1 (MuRF1). In DEX-treated mice with muscle atrophy, Valeriana fauriei supplementation increased the ability to exercise, muscle weight, and cross-sectional area, whereas it inhibited myosin heavy chain isoform transition and the expression of muscle atrophy biomarkers. Valeriana fauriei treatment led to via the downregulation of muscle atrophic genes via inhibition of GC receptor translocation. Valeriana fauriei was also found to act as a reactive oxygen species (ROS) scavenger. Didrovaltrate (DI), an iridoid compound from Valeriana fauriei, was found to downregulate atrophic genes and decrease ROS in the DEX-induced myotube atrophy. Consolidated, our results indicate that Valeriana fauriei prevents DEX-induced muscle atrophy by inhibiting GC receptor translocation. Further, Valeriana fauriei acts as a ROS scavenger, and its functional compound is didrovaltrate. We suggest that Valeriana fauriei and its functional compound didrovaltrate possess therapeutic potentials against muscle atrophy.

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Integrin signaling's potential for mediating gene expression in hypertrophying skeletal muscle

Journal of Applied Physiology ◽

10.1152/jappl.2000.88.1.337 ◽

2000 ◽

Vol 88 (1) ◽

pp. 337-343 ◽

Cited By ~ 73

Author(s):

James A. Carson ◽

Lei Wei

Keyword(s):

Gene Expression ◽

Skeletal Muscle ◽

Signaling Pathway ◽

Mechanical Load ◽

Integrin Signaling ◽

Mechanical Forces ◽

Growth Factor Signaling ◽

Muscle Gene

Overloaded skeletal muscle undergoes dramatic shifts in gene expression, which alter both the phenotype and mass. Molecular biology techniques employing both in vivo and in vitro hypertrophy models have demonstrated that mechanical forces can alter skeletal muscle gene regulation. This review's purpose is to support integrin-mediated signaling as a candidate for mechanical load-induced hypertrophy. Research quantifying components of the integrin-signaling pathway in overloaded skeletal muscle have been integrated with knowledge regarding integrins role during development and cardiac hypertrophy, with the hope of demonstrating the pathway's importance. The role of integrin signaling as an integrator of mechanical forces and growth factor signaling during hypertrophy is discussed. Specific components of integrin signaling, including focal adhesion kinase and low-molecular-weight GTPase Rho are mentioned as downstream targets of this signaling pathway. There is a need for additional mechanistic studies capable of providing a stronger linkage between integrin-mediated signaling and skeletal muscle hypertrophy; however, there appears to be abundant justification for this type of research.

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Ectopic expression of IGF‐I and Shh by skeletal muscle inhibits disuse‐mediated skeletal muscle atrophy and bone osteopenia in vivo

The FASEB Journal ◽

10.1096/fj.03-0293fje ◽

2003 ◽

Vol 18 (1) ◽

pp. 221-223 ◽

Cited By ~ 69

Author(s):

Mohammed Borhan Alzghoul ◽

Dave Gerrard ◽

Bruce A. Watkins ◽

Kevin Hannon

Keyword(s):

Skeletal Muscle ◽

Muscle Atrophy ◽

Ectopic Expression ◽

Skeletal Muscle Atrophy ◽

Igf I

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Preclinical Evaluation of a Food-Derived Functional Ingredient to Address Skeletal Muscle Atrophy

Nutrients ◽

10.3390/nu12082274 ◽

2020 ◽

Vol 12 (8) ◽

pp. 2274

Author(s):

Roi Cal ◽

Heidi Davis ◽

Alish Kerr ◽

Audrey Wall ◽

Brendan Molloy ◽

...

Keyword(s):

Skeletal Muscle ◽

Muscle Atrophy ◽

Soleus Muscle ◽

Murine Model ◽

The Body ◽

Skeletal Muscle Atrophy ◽

Type I ◽

Disuse Atrophy ◽

Tnf Α

Skeletal muscle is the metabolic powerhouse of the body, however, dysregulation of the mechanisms involved in skeletal muscle mass maintenance can have devastating effects leading to many metabolic and physiological diseases. The lack of effective solutions makes finding a validated nutritional intervention an urgent unmet medical need. In vitro testing in murine skeletal muscle cells and human macrophages was carried out to determine the effect of a hydrolysate derived from vicia faba (PeptiStrong: NPN_1) against phosphorylated S6, atrophy gene expression, and tumour necrosis factor alpha (TNF-α) secretion, respectively. Finally, the efficacy of NPN_1 on attenuating muscle waste in vivo was assessed in an atrophy murine model. Treatment of NPN_1 significantly increased the phosphorylation of S6, downregulated muscle atrophy related genes, and reduced lipopolysaccharide-induced TNF-α release in vitro. In a disuse atrophy murine model, following 18 days of NPN_1 treatment, mice exhibited a significant attenuation of muscle loss in the soleus muscle and increased the integrated expression of Type I and Type IIa fibres. At the RNA level, a significant upregulation of protein synthesis-related genes was observed in the soleus muscle following NPN_1 treatment. In vitro and preclinical results suggest that NPN_1 is an effective bioactive ingredient with great potential to prolong muscle health.

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