scholarly journals Electrical stimulation prevents doxorubicin-induced atrophy and mitochondrial loss in cultured myotubes

2019 ◽  
Vol 317 (6) ◽  
pp. C1213-C1228 ◽  
Author(s):  
Blas A. Guigni ◽  
Dennis K. Fix ◽  
Joseph J. Bivona ◽  
Bradley M. Palmer ◽  
James A. Carson ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Ring Finger ◽  
Mechanical Stretch ◽  
Skeletal Muscle Atrophy ◽  
C2c12 Myotubes ◽  
Peroxisome Proliferator ◽  
Ros Production ◽  
Mitochondrial Content ◽  
Peroxisome Proliferator Activated Receptor

Muscle contraction may protect against the effects of chemotherapy to cause skeletal muscle atrophy, but the mechanisms underlying these benefits are unclear. To address this question, we utilized in vitro modeling of contraction and mechanotransduction in C2C12 myotubes treated with doxorubicin (DOX; 0.2 μM for 3 days). Myotubes expressed contractile proteins and organized these into functional myofilaments, as electrical field stimulation (STIM) induced intracellular calcium (Ca2+) transients and contractions, both of which were prevented by inhibition of membrane depolarization. DOX treatment reduced myotube myosin content, protein synthesis, and Akt (S308) and forkhead box O3a (FoxO3a; S253) phosphorylation and increased muscle RING finger 1 (MuRF1) expression. STIM (1 h/day) prevented DOX-induced reductions in myotube myosin content and Akt and FoxO3a phosphorylation, as well as increases in MuRF1 expression, but did not prevent DOX-induced reductions in protein synthesis. Inhibition of myosin-actin interaction during STIM prevented contraction and the antiatrophic effects of STIM without affecting Ca2+ cycling, suggesting that the beneficial effect of STIM derives from mechanotransductive pathways. Further supporting this conclusion, mechanical stretch of myotubes recapitulated the effects of STIM to prevent DOX suppression of FoxO3a phosphorylation and upregulation of MuRF1. DOX also increased reactive oxygen species (ROS) production, which led to a decrease in mitochondrial content. Although STIM did not alter DOX-induced ROS production, peroxisome proliferator-activated receptor-γ coactivator-1α and antioxidant enzyme expression were upregulated, and mitochondrial loss was prevented. Our results suggest that the activation of mechanotransductive pathways that downregulate proteolysis and preserve mitochondrial content protects against the atrophic effects of chemotherapeutics.

scholarly journals N-acetyl-L-cysteine Prevents Lactate-Mediated PGC1-alpha Expression in C2C12 Myotubes

Biology ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 44 ◽  
Author(s):  
Minas Nalbandian ◽  
Zsolt Radak ◽  
Masaki Takeda
Keyword(s):  
Lactate Production ◽  
C2c12 Myotubes ◽  
Peroxisome Proliferator ◽  
Oxygen Species ◽  
Lactate Metabolism ◽  
Peroxisome Proliferator Activated Receptor ◽  
Intermittent Exposure ◽  
Physiological Adaptations ◽  
Cultured Myotubes

Background: Exercise induces many physiological adaptations. Recently, it has been proposed that some of these adaptations are induced by exercise-mediated lactate production. In this study, we aimed to investigate in vitro the effect of lactate in cultured myotubes and whether antioxidants could inhibit the effect. Methods: Differentiated myotubes were cultured at different concentrations of L-lactate (0, 10, 30, 50 mM) in the absence or presence of an antioxidant, N-acetyl-L-cysteine (Nac). The temporal effect of lactate exposure in myotubes was also explored. Results: Two hours of exposure to 50 mM L-lactate and six hours of exposure to 30 or 50 mM L-lactate caused a significant increase in PGC1-alpha (peroxisome proliferator-activated receptor γ coactivator-1α) expression in the myotubes. This up-regulation was suppressed by 2 mM Nac. Intermittent and continuous lactate exposure caused similar PGC1-alpha up-regulation. These results suggest that the increase in PGC1-alpha expression is mediated by reactive oxygen species (ROS) production from lactate metabolism and that both continuous and intermittent exposure to L-lactate can cause the up-regulation.

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.

scholarly journals Glucose deprivation, oxidative stress and peroxisome proliferator-activated receptor-α (PPARA) cause peroxisome proliferation in preimplantation mouse embryos

Reproduction ◽  
2009 ◽  
Vol 138 (3) ◽  
pp. 493-505 ◽  
Author(s):  
Sarah Jansen ◽  
Kara Cashman ◽  
Jeremy G Thompson ◽  
Marie Pantaleon ◽  
Peter L Kaye
Keyword(s):  
Oxidative Stress ◽  
Ex Vivo ◽  
Glucose Deprivation ◽  
Mouse Embryos ◽  
Peroxisome Proliferator ◽  
Ros Production ◽  
Peroxisome Proliferator Activated Receptor ◽  
Preimplantation Mouse ◽  
Proliferation Response

Ex vivotwo-cell mouse embryos deprived of glucosein vitrocan develop to blastocysts by increasing their pyruvate consumption; however, zygotes when glucose-deprived cannot adapt this metabolic profile and degenerate as morulae. Prior to their death, these glucose-deprived morulae exhibit upregulation of the H+-monocarboxylate co-transporter SLC16A7 and catalase, which partly co-localize in peroxisomes. SLC16A7 has been linked to redox shuttling for peroxisomal β-oxidation. Peroxisomal function is unclear during preimplantation development, but as a peroxisomal transporter in embryos, SLC16A7 may be involved and influenced by peroxisome proliferators such as peroxisome proliferator-activated receptor-α (PPARA). PCR confirmedPparamRNA expression in mouse embryos. Zygotes were cultured with or without glucose and with the PPARA-selective agonist WY14643 and the developing embryos assessed for expression of PPARA and phospho-PPARA in relation to the upregulation of SLC16A7 and catalase driven by glucose deprivation, indicative of peroxisomal proliferation. Reactive oxygen species (ROS) production and relationship to PPARA expression were also analysed. In glucose-deprived zygotes, ROS was elevated within 2 h, as were PPARA expression within 8 h and catalase and SLC16A7 after 12–24 h compared with glucose-supplied embryos. Inhibition of ROS production prevented this induction of PPARA and SLC16A7. Selective PPARA agonism with WY14643 also induced SLC16A7 and catalase expression in the presence of glucose. These data suggest that glucose-deprived cleavage stage embryos, although supplied with sufficient monocarboxylate-derived energy, undergo oxidative stress and exhibit elevated ROS, which in turn upregulates PPARA, catalase and SLC16A7 in a classical peroxisomal proliferation response.

scholarly journals Citrus hassaku Extract Powder Increases Mitochondrial Content and Oxidative Muscle Fibers by Upregulation of PGC-1α in Skeletal Muscle

Nutrients ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 497
Author(s):  
Shiori Akashi ◽  
Akihito Morita ◽  
Yusuke Mochizuki ◽  
Fuka Shibuya ◽  
Yasutomi Kamei ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Skeletal Muscles ◽  
Control Diet ◽  
C2c12 Myotubes ◽  
Peroxisome Proliferator ◽  
Mitochondrial Content ◽  
Peroxisome Proliferator Activated Receptor ◽  
Cultured Myotubes ◽  
Citrus Hassaku ◽  
Amp Activated Protein Kinase

Peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) is expressed in skeletal muscles and regulates systemic metabolism. Thus, nutraceuticals targeting skeletal muscle PGC-1α have attracted attention to modulate systemic metabolism. As auraptene contained in citrus fruits promotes lipid metabolism and improves mitochondrial respiration, it could increase mitochondrial function through PGC-1α. Therefore, we hypothesized that PGC-1α is activated by auraptene and investigated its effect using Citrus hassaku extract powder (CHEP) containing >80% of auraptene. C2C12 myotubes were incubated with vehicle or CHEP for 24 h; C57BL/6J mice were fed a control diet or a 0.25% (w/w) CHEP-containing diet for 5 weeks. PGC-1α protein level and mitochondrial content increased following CHEP treatment in cultured myotubes and skeletal muscles. In addition, the number of oxidative fibers increased in CHEP-fed mice. These findings suggest that CHEP-mediated PGC-1α upregulation induced mitochondrial biogenesis and fiber transformation to oxidative fibers. Furthermore, as CHEP increased the expression of the protein sirtuin 3 and of phosphorylated AMP-activated protein kinase (AMPK) and the transcriptional activity of PGC-1α, these molecules might be involved in CHEP-induced effects in skeletal muscles. Collectively, our findings indicate that CHEP mediates PGC-1α expression in skeletal muscles and may serve as a dietary supplement to prevent metabolic disorders.

In vitro Studies on Antidiabetic Potential of New Dosage Forms of AYUSH 82

2017 ◽  
Vol 2 (1) ◽  
pp. 1-9
Author(s):  
M Setia ◽  
K Meena ◽  
A Madaan ◽  
Kartar S Dhiman ◽  
JLN Sastry
Keyword(s):  
Glucose Uptake ◽  
Dosage Forms ◽  
C2c12 Myotubes ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Test Items ◽  
Ppar Γ ◽  
Central Council ◽  
Insulin Dependent

ABSTRACT AYUSH 82 powder is an Ayurvedic antidiabetic formulation developed by the Central Council for Research in Ayurvedic Sciences (CCRAS), Ministry of AYUSH, Government of India. It comprises ingredients traditionally used for their beneficial effect in diabetes (Prameha/Madhumeha). The hypoglycemic effects of AYUSH 82 powder have been reported in diabetic subjects. In the current study, the antidiabetic potential of AYUSH 82 powder along with its two new dosage forms – AYUSH 82 mixture extract and AYUSH 82 compound extract- was investigated in vitro for elucidating mechanism of their action by possible α-amylase inhibitory property, insulin-dependent glucose uptake in skeletal muscle cell line (C2C12 myotubes), and effect on peroxisome proliferator-activated receptor gamma (PPAR-γ) activity. All the three dosage forms of AYUSH 82 – powder, mixture extract, and compound extract – exhibited inhibition of α-amylase activity. AYUSH 82 mixture extract, however, demonstrated highest extent of inhibition in both methanolic (87.4%) and aqueous (48.2%) format. All the three dosage forms of AYUSH 82 also demonstrated an increase in insulin-dependent glucose uptake in C2C12 myotubes as compared with control. However, none of the test items (TIs) exhibited activation of PPAR-γ expression in tested ranges, indicating that antidiabetic potential of TIs may not be mediated via PPAR-γ activation. Results indicated that the new dosage forms of AYUSH 82 (mixture extract and compound extract) may be useful for making new dosage forms of AYUSH 82 as tablets/capsule, etc. How to cite this article Setia M, Meena K, Madaan A, Srikanth N, Dhiman KS, Sastry JLN. In vitro Studies on Antidiabetic Potential of New Dosage Forms of AYUSH 82. J Drug Res Ayurvedic Sci 2017;2(1):1-9.

scholarly journals Preventive Effects of Schisandrin A, A Bioactive Component of Schisandra chinensis, on Dexamethasone-Induced Muscle Atrophy

Nutrients ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1255
Author(s):  
MyeongHoon Yeon ◽  
Hojung Choi ◽  
Hee-Sook Jun
Keyword(s):  
Protein Synthesis ◽  
Muscle Atrophy ◽  
Ring Finger ◽  
Therapeutic Interventions ◽  
C2c12 Myotubes ◽  
Potential Candidate ◽  
Schisandra Chinensis ◽  
Muscle Weight ◽  
Underlying Mechanisms

Muscle wasting is caused by various factors, such as aging, cancer, diabetes, and chronic kidney disease, and significantly decreases the quality of life. However, therapeutic interventions for muscle atrophy have not yet been well-developed. In this study, we investigated the effects of schisandrin A (SNA), a component extracted from the fruits of Schisandra chinensis, on dexamethasone (DEX)-induced muscle atrophy in mice and studied the underlying mechanisms. DEX+SNA-treated mice had significantly increased grip strength, muscle weight, and muscle fiber size compared with DEX+vehicle-treated mice. In addition, SNA treatment significantly reduced the expression of muscle degradation factors such as myostatin, MAFbx (atrogin1), and muscle RING-finger protein-1 (MuRF1) and enhanced the expression of myosin heavy chain (MyHC) compared to the vehicle. In vitro studies using differentiated C2C12 myotubes also showed that SNA treatment decreased the expression of muscle degradation factors induced by dexamethasone and increased protein synthesis and expression of MyHCs by regulation of Akt/FoxO and Akt/70S6K pathways, respectively. These results suggest that SNA reduces protein degradation and increases protein synthesis in the muscle, contributing to the amelioration of dexamethasone-induced muscle atrophy and may be a potential candidate for the prevention and treatment of muscle atrophy.

A novel hindlimb immobilization procedure for studying skeletal muscle atrophy and recovery in mouse

2009 ◽  
Vol 106 (6) ◽  
pp. 2049-2059 ◽  
Author(s):  
Annabelle Z. Caron ◽  
Geneviève Drouin ◽  
Justine Desrosiers ◽  
Frédéric Trensz ◽  
Guillaume Grenier
Keyword(s):  
Skeletal Muscle ◽  
Muscle Atrophy ◽  
Uncoupling Protein ◽  
Ring Finger ◽  
Muscle Metabolism ◽  
Skeletal Muscle Atrophy ◽  
Peroxisome Proliferator ◽  
Cast Immobilization ◽  
Peroxisome Proliferator Activated Receptor ◽  
Molecular Events

Skeletal muscle atrophy is a serious concern for patients afflicted by limb restriction due to surgery (e.g., arthrodesis), several articular pathologies (e.g., arthralgia), or simply following cast immobilization. To study the molecular events involved in this immobilization-induced debilitating condition, a convenient mouse model for atrophy is lacking. Here we provide a new immobilization procedure exploiting the normal flexion of the mouse hindlimb using a surgical staple to fix the ventral part of the foot to the distal part of the calf. Histological analysis revealed that our approach induced significant skeletal muscle atrophy by reducing the myofiber size of the tibialis anterior (TA) muscle by 36% compared with the untreated contralateral TA within a few days postimmobilization. Two molecular markers for atrophy, atrogin-1/muscle atrophy F-box (atrogin-1/MAFbx) and muscle ring finger 1 (MuRF-1) mRNAs, were significantly upregulated by 1.9- and 5.9-fold, respectively. Interestingly, our model also revealed the presence of an early inflammatory process during atrophy, characterized by the mRNA upregulation of TNF-α, IL-1, and IL-6 (1.9-, 2.4-, and 3.4-fold, respectively) simultaneously with the upregulation of the common leukocyte marker CD45 (6.1-fold). Moreover, muscle rapidly recovered on remobilization, an event associated with significantly increased levels of uncoupling protein-3 and peroxisome proliferator-activated receptor γ coactivator-1α mRNA, key components of prooxidative muscle metabolism. This model offers unexpected new insights into the molecular events involved in immobilization atrophy.

Protein synthesis and the expression of growth-related genes are altered by running in human vastus lateralis and soleus muscles

2009 ◽  
Vol 296 (3) ◽  
pp. R708-R714 ◽  
Author(s):  
Matthew P. Harber ◽  
Justin D. Crane ◽  
Jared M. Dickinson ◽  
Bozena Jemiolo ◽  
Ulrika Raue ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Metabolic Response ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Vastus Lateralis ◽  
Muscle Growth ◽  
Ring Finger ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Before And After

Recent evidence suggests aerobic exercise may help preserve soleus muscle mass during unloading. The purpose of this investigation was to examine the muscle-specific metabolic response to running as it relates to muscle growth. Mixed-muscle protein synthesis [fractional synthetic rate (FSR)] and gene expression (GE) were examined in the vastus lateralis (VL) and soleus (SOL) muscles from eight men (26 ± 2 yr; V̇o2max 63 ± 2 ml·kg−1·min−1) before and after a 45-min level-grade treadmill run at 77 ± 1% intensity. Muscle glycogen utilization was similar between muscles. Resting FSR was similar between the VL (0.080 ± 0.007 %/h) and SOL (0.086 ± 0.008 %/h) and was higher ( P < 0.05) 24 h postexercise compared with rest for both muscles. The absolute change in FSR was not different between muscles (0.030 ± 0.007 vs. 0.037 ± 0.012 %/h for VL and SOL). At baseline, myostatin GE was approximately twofold higher ( P < 0.05) in SOL compared with VL, while no other muscle-specific differences in GE were present. After running, myostatin GE was suppressed ( P < 0.05) in both muscles at 4 h and was higher ( P < 0.05) than baseline at 24 h for VL only. Muscle regulatory factor 4 mRNA was elevated ( P < 0.05) at 4 h in both SOL and VL; MyoD and peroxisome-proliferator-activated receptor-gamma coactivator-1α (PGC-1α) were higher ( P < 0.05) at 4 h, and forkhead box [FOXO]3A was higher at 24 h in SOL only, while muscle-RING-finger protein-1 (MuRF-1) was higher ( P < 0.05) at 4 h in VL only. Myogenin and atrogin-1 GE were unaltered. The similar increases between muscles in FSR support running as part of the exercise countermeasure to preserve soleus mass during unloading. The subtle differences in GE suggest a potential mechanism for muscle-specific adaptations to chronic run training.

scholarly journals Adipocyte PHLPP2 inhibition prevents obesity-induced fatty liver

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
KyeongJin Kim ◽  
Jin Ku Kang ◽  
Young Hoon Jung ◽  
Sang Bae Lee ◽  
Raffaela Rametta ◽  
...  
Keyword(s):  
Fatty Liver ◽  
Whole Body ◽  
Acid Oxidation ◽  
Chow Diet ◽  
Peroxisome Proliferator ◽  
Obese Mice ◽  
Ph Domain ◽  
Peroxisome Proliferator Activated Receptor

AbstractIncreased adiposity confers risk for systemic insulin resistance and type 2 diabetes (T2D), but mechanisms underlying this pathogenic inter-organ crosstalk are incompletely understood. We find PHLPP2 (PH domain and leucine rich repeat protein phosphatase 2), recently identified as the Akt Ser473 phosphatase, to be increased in adipocytes from obese mice. To identify the functional consequence of increased adipocyte PHLPP2 in obese mice, we generated adipocyte-specific PHLPP2 knockout (A-PHLPP2) mice. A-PHLPP2 mice show normal adiposity and glucose metabolism when fed a normal chow diet, but reduced adiposity and improved whole-body glucose tolerance as compared to Cre- controls with high-fat diet (HFD) feeding. Notably, HFD-fed A-PHLPP2 mice show increased HSL phosphorylation, leading to increased lipolysis in vitro and in vivo. Mobilized adipocyte fatty acids are oxidized, leading to increased peroxisome proliferator-activated receptor alpha (PPARα)-dependent adiponectin secretion, which in turn increases hepatic fatty acid oxidation to ameliorate obesity-induced fatty liver. Consistently, adipose PHLPP2 expression is negatively correlated with serum adiponectin levels in obese humans. Overall, these data implicate an adipocyte PHLPP2-HSL-PPARα signaling axis to regulate systemic glucose and lipid homeostasis, and suggest that excess adipocyte PHLPP2 explains decreased adiponectin secretion and downstream metabolic consequence in obesity.

scholarly journals The lipid-lowering drug fenofibrate combined with si-HOTAIR can effectively inhibit the proliferation of gliomas

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Wei Zhu ◽  
Hongyang Zhao ◽  
Fenfen Xu ◽  
Bin Huang ◽  
Xiaojing Dai ◽  
...  
Keyword(s):  
Noncoding Rna ◽  
Glioma Cells ◽  
Lipid Lowering ◽  
Fibric Acid Derivative ◽  
Peroxisome Proliferator ◽  
Glioma Invasion ◽  
Peroxisome Proliferator Activated Receptor ◽  
Lncrna Hotair

Abstract Background Fenofibrate is a fibric acid derivative known to have a lipid-lowering effect. Although fenofibrate-induced peroxisome proliferator-activated receptor alpha (PPARα) transcription activation has been shown to play an important role in the malignant progression of gliomas, the underlying mechanisms are poorly understood. Methods In this study, we analyzed TCGA database and found that there was a significant negative correlation between the long noncoding RNA (lncRNA) HOTAIR and PPARα. Then, we explored the molecular mechanism by which lncRNA HOTAIR regulates PPARα in cell lines in vitro and in a nude mouse glioma model in vivo and explored the effect of the combined application of HOTAIR knockdown and fenofibrate treatment on glioma invasion. Results For the first time, it was shown that after knockdown of the expression of HOTAIR in gliomas, the expression of PPARα was significantly upregulated, and the invasion and proliferation ability of gliomas were obviously inhibited. Then, glioma cells were treated with both the PPARα agonist fenofibrate and si-HOTAIR, and the results showed that the proliferation and invasion of glioma cells were significantly inhibited. Conclusions Our results suggest that HOTAIR can negatively regulate the expression of PPARα and that the combination of fenofibrate and si-HOTAIR treatment can significantly inhibit the progression of gliomas. This introduces new ideas for the treatment of gliomas.

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