scholarly journals Docosahexaenoic Acid Protects Muscle Cells from Palmitate-Induced Atrophy

ISRN Obesity ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Randall W. Bryner ◽  
Myra E. Woodworth-Hobbs ◽  
David L. Williamson ◽  
Stephen E. Alway
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acids ◽  
Docosahexaenoic Acid ◽  
Muscle Atrophy ◽  
Muscle Growth ◽  
Muscle Cells ◽  
Skeletal Muscle Atrophy ◽  
Omega 3 ◽  
Myotube Hypertrophy

Background. Accumulation of free fatty acids leads to lipid-toxicity-associated skeletal muscle atrophy. Palmitate treatment reduces myoblast and myotube growth and causes apoptosis in vitro. It is not known if omega-3 fatty acids will protect muscle cells against palmitate toxicity. Therefore, we examined the effects of docosahexaenoic acid (DHA) on skeletal muscle growth. Methods. Mouse myoblasts (C2C12) were differentiated to myotubes, and then treated with 0 or 0.5 mM palmitic acid or 0 or 0.1 mM DHA. Results. Intramyocellular lipid was increased in palmitate-treated cells but was prevented by DHA-palmitate cotreatment. Total AMPK increased in DHA+ palmitate-treated compared to palmitate only cells. RpS6 phosphorylation decreased after palmitate (−55%) and this was blunted by DHA+ palmitate (−35%) treatment. Palmitate treatment decreased PGC1 protein expression by 69%, but was increased 165% with DHA+ palmitate () versus palmitate alone. While palmitate induced 25% and 90% atrophy in myotubes (after 48 hours and 96 hours, resp.), DHA+ palmitate treatment caused myotube hypertrophy of ~50% and 100% after 48 and 96 hours, respectively. Conclusion. These data show that DHA is protective against palmitate-induced atrophy. Although DHA did not activate the AMPK pathway, DHA treatment restored growth-signaling (i.e., rpS6) and rescued palmitate-induced muscle atrophy.

scholarly journals FGF-2–dependent signaling activated in aged human skeletal muscle promotes intramuscular adipogenesis

2021 ◽  
Vol 118 (37) ◽  
pp. e2021013118 ◽  
Author(s):  
Sebastian Mathes ◽  
Alexandra Fahrner ◽  
Umesh Ghoshdastider ◽  
Hannes A. Rüdiger ◽  
Michael Leunig ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Transcriptional Activation ◽  
Human Skeletal Muscle ◽  
Muscle Growth ◽  
Muscle Cells ◽  
Adeno Associated Virus ◽  
Adult Skeletal Muscle

Aged skeletal muscle is markedly affected by fatty muscle infiltration, and strategies to reduce the occurrence of intramuscular adipocytes are urgently needed. Here, we show that fibroblast growth factor-2 (FGF-2) not only stimulates muscle growth but also promotes intramuscular adipogenesis. Using multiple screening assays upstream and downstream of microRNA (miR)-29a signaling, we located the secreted protein and adipogenic inhibitor SPARC to an FGF-2 signaling pathway that is conserved between skeletal muscle cells from mice and humans and that is activated in skeletal muscle of aged mice and humans. FGF-2 induces the miR-29a/SPARC axis through transcriptional activation of FRA-1, which binds and activates an evolutionary conserved AP-1 site element proximal in the miR-29a promoter. Genetic deletions in muscle cells and adeno-associated virus–mediated overexpression of FGF-2 or SPARC in mouse skeletal muscle revealed that this axis regulates differentiation of fibro/adipogenic progenitors in vitro and intramuscular adipose tissue (IMAT) formation in vivo. Skeletal muscle from human donors aged >75 y versus <55 y showed activation of FGF-2–dependent signaling and increased IMAT. Thus, our data highlights a disparate role of FGF-2 in adult skeletal muscle and reveals a pathway to combat fat accumulation in aged human skeletal muscle.

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

2020 ◽  
Author(s):  
Kathryn W. Aguilar-Agon ◽  
Andrew J. Capel ◽  
Jacob W. Fleming ◽  
Darren J. Player ◽  
Neil R. W. Martin ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Mechanical Loading ◽  
Muscle Atrophy ◽  
Mechanical Load ◽  
3D Models ◽  
Skeletal Muscle Atrophy ◽  
Treatment Modalities ◽  
Murine Cell Line

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.

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

Nutrients ◽  
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.

Inhibition of glycogen synthase kinase-3β activity is sufficient to stimulate myogenic differentiation

2006 ◽  
Vol 290 (2) ◽  
pp. C453-C462 ◽  
Author(s):  
Jos L. J. van der Velden ◽  
Ramon C. J. Langen ◽  
Marco C. J. M. Kelders ◽  
Emiel F. M. Wouters ◽  
Yvonne M. W. Janssen-Heininger ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Atrophy ◽  
Glycogen Synthase ◽  
Muscle Growth ◽  
Glycogen Synthase Kinase ◽  
Skeletal Muscle Atrophy ◽  
Glycogen Synthase Kinase 3Β ◽  
Igf I ◽  
Gsk 3Β ◽  
Stimulation Of

Skeletal muscle atrophy is a prominent and disabling feature of chronic wasting diseases. Prevention or reversal of muscle atrophy by administration of skeletal muscle growth (hypertrophy)-stimulating agents such as insulin-like growth factor I (IGF-I) could be an important therapeutic strategy in these diseases. To elucidate the IGF-I signal transduction responsible for muscle formation (myogenesis) during muscle growth and regeneration, we applied IGF-I to differentiating C2C12 myoblasts and evaluated the effects on phosphatidylinositol 3-kinase (PI3K)/Akt/glycogen synthase kinase-3β (GSK-3β) signaling and myogenesis. IGF-I caused phosphorylation and inactivation of GSK-3β activity via signaling through the PI3K/Akt pathway. We assessed whether pharmacological inhibition of GSK-3β with lithium chloride (LiCl) was sufficient to stimulate myogenesis. Addition of IGF-I or LiCl stimulated myogenesis, evidenced by increased myotube formation, muscle creatine kinase (MCK) activity, and troponin I (TnI) promoter transactivation during differentiation. Moreover, mRNAs encoding MyoD, Myf-5, myogenin, TnI-slow, TnI-fast, MCK, and myoglobin were upregulated in myoblasts differentiated in the presence of IGF-I or LiCl. Importantly, blockade of GSK-3β inhibition abrogated IGF-I- but not LiCl-dependent stimulation of myogenic mRNA accumulation, suggesting that the promyogenic effects of IGF-I require GSK-3β inactivation and revealing an important negative regulatory role for GSK-3β in myogenesis. Therefore, this study identifies GSK-3β as a potential target for pharmacological stimulation of muscle growth.

scholarly journals Trimetazidine attenuates dexamethasone-induced muscle atrophy via inhibiting NLRP3/GSDMD pathway-mediated pyroptosis

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Li Wang ◽  
Xin-Feng Jiao ◽  
Cheng Wu ◽  
Xiao-Qing Li ◽  
Hui-Xian Sun ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Atrophy ◽  
Muscle Performance ◽  
Skeletal Muscle Atrophy ◽  
C2c12 Myotubes ◽  
High Dose ◽  
Protective Effects ◽  
Akt Inhibitor ◽  
Caspase 1

AbstractSkeletal 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 improve skeletal muscle performance both in humans and mice. We here showed that dexamethasone-induced atrophy, as 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 NLR family pyrin domain containing 3 (NLRP3), Caspase-1, and gasdermin-D (GSDMD). Knockdown of NLRP3 or GSDMD attenuated dexamethasone-induced myotube pyroptosis and atrophy. Trimetazidine treatment ameliorated dexamethasone-induced muscle pyroptosis and atrophy both in vivo and in vitro. Activation of NLRP3 using LPS and ATP not only increased the cleavage and activation of Caspase-1 and GSDMD, but also increased the expression levels of atrophy markers MuRF1 and Atrogin-1 in trimetazidine-treated C2C12 myotubes. Mechanically, dexamethasone inhibited the phosphorylation of PI3K/AKT/FoxO3a, which could be attenuated by trimetazidine. Conversely, co-treatment with a PI3K/AKT inhibitor, picropodophyllin, remarkably increased the expression of NLRP3 and reversed the protective effects of trimetazidine against dexamethasone-induced C2C12 myotube pyroptosis and atrophy. Taken together, our study suggests that NLRP3/GSDMD-mediated pyroptosis might be a novel mechanism for dexamethasone-induced skeletal muscle atrophy. Trimetazidine might be developed as a potential therapeutic agent for the treatment of dexamethasone-induced muscle atrophy.

scholarly journals Sphingosine-1-phosphate analog FTY720 reverses obesity but not age-induced anabolic resistance to muscle contraction

2019 ◽  
Vol 317 (3) ◽  
pp. C502-C512
Author(s):  
Donato A. Rivas ◽  
Nicholas P. Rice ◽  
Yassine Ezzyat ◽  
Devin J. McDonald ◽  
Brittany E. Cooper ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acid ◽  
Palmitic Acid ◽  
Muscle Contraction ◽  
Chronic Inflammation ◽  
Muscle Atrophy ◽  
Muscle Cells ◽  
Skeletal Muscle Atrophy ◽  
Anabolic Resistance ◽  
Sphingosine 1 Phosphate

Sarcopenia, the age-associated loss of skeletal muscle mass and function, is coupled with declines in physical functioning leading to subsequent higher rates of disability, frailty, morbidity, and mortality. Aging and obesity independently contribute to muscle atrophy that is assumed to be a result of the activation of mutual physiological pathways. Understanding mechanisms contributing to the induction of skeletal muscle atrophy with aging and obesity is important for determining targets that may have pivotal roles in muscle loss in these conditions. We find that aging and obesity equally induce an anabolic resistance to acute skeletal muscle contraction as observed with decreases in anabolic signaling activation after contraction. Furthermore, treatment with the sphingosine-1-phosphate analog FTY720 for 4 wk increased lean mass and strength, and the anabolic signaling response to contraction was improved in obese but not older animals. To determine the role of chronic inflammation and different fatty acids on anabolic resistance in skeletal muscle cells, we overexpressed IKKβ with and without exposure to saturated fatty acid (SFA; palmitic acid), polyunsaturated fatty acid (eicosapentaenoic acid), and monounsaturated fatty acid (oleic acid). We found that IKKβ overexpression increased inflammation markers in muscle cells, and this chronic inflammation exacerbated anabolic resistance in response to SFA. Pretreatment with FTY720 reversed the inflammatory effects of palmitic acid in the muscle cells. Taken together, these data demonstrate chronic inflammation can induce anabolic resistance, SFA aggravates these effects, and FTY720 can reverse this by decreasing ceramide accumulation in skeletal muscle.

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

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.

PSII-18 The effects of fish oil supplementation on markers of inflammation and skeletal muscle and adipose growth in pigs

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 314-315
Author(s):  
Lillian L Okamoto ◽  
Caleb C Reichhardt ◽  
Sierra Lopez ◽  
Anthony F Alberto ◽  
Reganne K Briggs ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acids ◽  
Fish Oil ◽  
Muscle Growth ◽  
Basal Diet ◽  
Omega 3 Fatty Acids ◽  
Omega 3 ◽  
Lps Challenge ◽  
Markers Of Inflammation ◽  
Fish Oil Supplementation

Abstract Omega-3 fatty acids have immunomodulatory and anti-inflammatory effects. The objective of this project was to determine the effects of fish oil, a source of omega-3 fatty acids, on genes involved in inflammation and growth of skeletal muscle tissue after an LPS challenge. Male Landrace-New Hampshire weaned piglets (BW 8.21±0.83 kg) were used in a randomized complete block design and assigned to two treatments: 1) basal diet (n=7) and 2) basal diet plus 3% fish oil added (n = 7). Treatments were fed for 35 d. On d 34, an LPS challenge was performed and 24 h later, piglets were euthanized and skeletal muscle samples were collected from the longissimus lumborum and biceps femoris. Total mRNA was isolated and markers of inflammation [cyclophilin (Cyclo), nuclear factor kappa beta subunit-1 (NF-kB), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6)], skeletal muscle growth [paired box transcription factor-7 (Pax7), myogenic factor-5 (Myf5), myoblast determination factor-1 (MyoD), myogenin (MyoG)] and adipose growth (peroxisome proliferator activated receptor (PPARy), leptin, and adiponectin) were analyzed. Cyclophilin abundance was increased (P = 0.03) in fish-oil piglets compared to control piglets. Other markers of inflammation (TNF-α, IL-6, NF-kB) were not affected (P &gt; 0.05) by fish-oil supplementation. Abundance of Myf5 was lower (P = 0.03) in fish oil piglets than control piglets. Other myogenic regulatory factors (Pax7, MyoD, MyoG) were not (P &gt; 0.05) altered by treatment. Abundance of PPARy, leptin or adiponectin was not affected (P &gt; 0.05) by fish-oil supplementation. Muscle location influenced (P &lt; 0.01) abundance of leptin and adiponectin, with abundance being higher in the biceps femoris than in the longissimus lumborum. No other genes analyzed were impacted by muscle location (P &gt; 0.05). Our findings suggest that supplementation of omega-3 fatty acids via fish-oil may affect the inflammatory response and skeletal muscle growth. Further research is needed to evaluate the impact of these results on animal production.

Dynamics of Toll-like receptors signaling in skeletal muscle atrophy

2021 ◽  
Vol 28 ◽  
Author(s):  
Aarti Yadav ◽  
Anil Dahuja ◽  
Rajesh Dabur
Keyword(s):  
Skeletal Muscle ◽  
Muscle Atrophy ◽  
Inflammatory Cytokine ◽  
Muscle Growth ◽  
Skeletal Muscle Atrophy ◽  
Muscle Loss ◽  
Protein Catabolism ◽  
Tlr Signaling ◽  
Recent Advancement ◽  
And Oxidative Stress

: Skeletal muscle atrophy has been characterizedas a state of uncontrolled inflammation and oxidative stress that escalates the protein catabolism. Recent advancement supportsthat impinging signaling molecules in the muscle fibers controlled throughtoll-like receptors (TLR). Activated TLR signalingpathways have been identified as inhibitors of muscle mass and provoke the settings for muscle atrophy. Among them, mainly TLR2 and TLR4 manifest their presence to exacerbate the release of the pro-inflammatory cytokine to deform the synchronized muscle programming. The present review enlightens the TLR signaling mediated muscle loss and their interplay betweeninflammationand skeletal muscle growth.

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