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1.
J Agric Food Chem ; 68(2): 530-540, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31891490

RESUMO

The influence of ß-hydroxy-ß-methylbutyrate (HMB) on proliferation and differentiation of myogenic cells has been well-studied. However, the role of HMB in myofiber specification and potential mechanisms is largely unknown. Thus, the objective of this research was to explore the role of HMB supplementation in myofiber specification. Results showed that HMB treatment significantly increased the fast MyHC protein level (mice: 1.59 ± 0.08, P < 0.01; C2C12: 2.26 ± 0.11, P < 0.001), decreased the slow MyHC protein level (mice: 0.76 ± 0.05, P < 0.05; C2C12: 0.52 ± 0.02, P < 0.001), and increased the miR-199a-3p level (mice: 4.93 ± 0.37, P < 0.001; C2C12: 11.25 ± 0.57, P < 0.001). Besides, we also observed that HMB promoted the activity of glycolysis-related enzymes and reduced the activities of oxidation-related enzymes in mice and C2C12 cells. Overexpression of miR-199a-3p downregulated the slow MyHC protein level (0.71 ± 0.02, P < 0.01) and upregulated the fast MyHC protein level (2.13 ± 0.09, P < 0.001), while repression of miR-199a-3p exhibited the opposite effect. Target identification results verified that miR-199a-3p targets the 3'UTR of the TEA domain family member 1 (TEAD1) to cause its post-transcriptional inhibition (0.41 ± 0.07, P < 0.01). Knockdown of TEAD1 exhibited a similar effect with miR-199a-3p on myofiber specification. Moreover, suppression of miR-199a-3p blocked slow-to-fast myofiber type transition induced by HMB. Together, our finding revealed that miR-199-3p is induced by HMB and contributes to the action of HMB on slow-to-fast myofiber type conversion via targeting TEAD1.


Assuntos
MicroRNAs/metabolismo , Fibras Musculares Esqueléticas/efeitos dos fármacos , Mioblastos Esqueléticos/efeitos dos fármacos , Valeratos/farmacologia , Regiões 3' não Traduzidas , Animais , Diferenciação Celular/efeitos dos fármacos , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Camundongos , MicroRNAs/genética , Fibras Musculares Esqueléticas/citologia , Fibras Musculares Esqueléticas/metabolismo , Mioblastos Esqueléticos/citologia , Mioblastos Esqueléticos/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Regulação para Cima/efeitos dos fármacos
2.
Biochemistry (Mosc) ; 84(9): 1085-1092, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31693468

RESUMO

Many motor disorders are associated with depolarization of the membrane of skeletal muscle fibers due to the impaired functioning of Na,K-ATPase. Here, we studied the role of ouabain (specific Na,K-ATPase ligand) and AMP-activated protein kinase (key regulator of muscle metabolism) in the maintenance of muscle electrogenesis; the levels of these endogenous factors are directly related to the motor activity. After 4-day intraperitoneal administration of ouabain (1 µg/kg daily), a hyperpolarization of sarcolemma was registered in isolated rat diaphragm muscles due to an increase in the electrogenic activity of Na,K-ATPase. In acute experiments, addition of nanomolar ouabain concentrations to the bathing solution resulted in the muscle membrane hyperpolarization within 15 min. The effect of ouabain reversed to membrane depolarization with the increase in the external potassium concentration. It is possible that Na,K-ATPase activation by ouabain may be regulated by such factors as specific subcellular location, interaction with molecular partners, and changes in the ionic balance. Preventive administration of the AMP-activated protein kinase activator AICAR (5-aminoimidazole-4-carboxamide-1-ß-D-ribofuranoside; 400 mg/kg body weight daily for 7 days) in chronic experiments resulted in the stabilization of the endplate structure and abolishment of depolarization of the rat soleus muscle membrane caused by the motor activity cessation. The obtained data can be useful for creating approaches for correction of muscle dysfunction, especially at the early stages, prior to the development of muscle atrophy.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Potenciais de Ação/efeitos dos fármacos , Fibras Musculares Esqueléticas/efeitos dos fármacos , Ouabaína/administração & dosagem , Ouabaína/farmacologia , Aminoimidazol Carboxamida/administração & dosagem , Aminoimidazol Carboxamida/análogos & derivados , Aminoimidazol Carboxamida/farmacologia , Animais , Relação Dose-Resposta a Droga , Injeções Intraperitoneais , Masculino , Fibras Musculares Esqueléticas/enzimologia , Fibras Musculares Esqueléticas/metabolismo , Ratos , Ratos Wistar , Ribonucleotídeos/administração & dosagem , Ribonucleotídeos/farmacologia , ATPase Trocadora de Sódio-Potássio/metabolismo , Relação Estrutura-Atividade
3.
Life Sci ; 236: 116906, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31614147

RESUMO

AIMS: The anti-hyperglycemic action of metformin on skeletal muscles is presently unclear. Long noncoding RNAs (lncRNAs) are implicated in multiple cellular functions. This study aims to explore the role of lncRNAs in the glucometabolic action of metformin on skeletal muscle cells. MAIN METHODS: Metformin accumulation was assessed using [14C]-metformin. A lncRNA array was used to investigate metformin-regulated lncRNAs in C2C12 skeletal muscle cells. Knockdown studies were applied to evaluate the function of lncRNA Dreh. A colorimetric assay was used for the measurement of medium glucose concentration; glucose transport was assessed using [3H]-2-deoxyglucose; real-time PCR was used for RNA expression analysis, and western blotting was used to assess protein expression in myotubes. A Dreh overexpression plasmid was transfected into the cells. KEY FINDINGS: Metformin accumulated in C2C12 myotubes. Metformin reduced medium glucose concentration and repressed lncRNA Dreh expression in the myotubes. Knockdown of Dreh in the myotubes resulted in reduced glucose concentration in the culture medium, increased glucose transport, and increased levels of GLUT4 protein in the plasma membrane. Overexpression of Dreh attenuated the glucose-lowering effect of metformin in myotubes. SIGNIFICANCE: The glucoregulatory actions of metformin are mediated in part by a lncRNA, Dreh, in the skeletal muscle cells. Dreh is a novel regulator for glucose transport and could be a therapeutic target for diabetes.


Assuntos
Glucose/metabolismo , Hipoglicemiantes/farmacologia , Metformina/farmacologia , Fibras Musculares Esqueléticas/metabolismo , Músculo Esquelético/metabolismo , RNA Longo não Codificante/genética , Animais , Transporte Biológico , Linhagem Celular , Regulação da Expressão Gênica , Transportador de Glucose Tipo 4/genética , Transportador de Glucose Tipo 4/metabolismo , Camundongos , Fibras Musculares Esqueléticas/citologia , Fibras Musculares Esqueléticas/efeitos dos fármacos , Músculo Esquelético/citologia , Músculo Esquelético/efeitos dos fármacos
4.
Muscle Nerve ; 60(6): 801-810, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31531861

RESUMO

INTRODUCTION: Improved methods are needed to detect and quantify age-related muscle change. In this study we assessed the electrical properties of muscle impacted by acquired mitochondrial DNA mutations via the PolG mouse, which exhibits typical age-associated features, and the impact of a potential therapy, nicotinamide mononucleotide (NMN). METHODS: The gastrocnemii of 24 PolG and 30 wild-type (WT) mice (8 PolG and 17 WT treated with NMN) were studied in an electrical impedance-measuring cell. Conductivity and relative permittivity were determined from the impedance data. Myofiber cross-sectional area (CSA) was quantified histologically. RESULTS: Untreated PolG mice demonstrated alterations in several impedance features, including 50-kHz relative permittivity and center frequency. A potential effect of NMN was also observed in these parameters in PolG but not WT animals. Impedance values correlated with myofiber CSA. DISCUSSION: Electrical impedance is sensitive to myofiber features considered characteristic of aging and to the impact of a potential therapy.


Assuntos
Senilidade Prematura/fisiopatologia , Fibras Musculares Esqueléticas/patologia , Músculo Esquelético/fisiopatologia , Senilidade Prematura/patologia , Animais , Tamanho Celular , Polimerase do DNA Mitocondrial/genética , DNA Mitocondrial/genética , Modelos Animais de Doenças , Impedância Elétrica , Técnicas de Introdução de Genes , Camundongos , Fibras Musculares Esqueléticas/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/patologia , Mutação , Miografia/métodos , Mononucleotídeo de Nicotinamida/farmacologia
5.
Biomed Res Int ; 2019: 3719643, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31467885

RESUMO

Background: The clinical anti-inflammatory drug dexamethasone (DEX) can cause many side effects such as muscle atrophy for long-term use. Muscle atrophy induced by DEX may be caused by decrease of glucose consumption. Panax ginseng C.A. Meyer was previously considered to be an antiatrophic agent for glucocorticoid- (GC-) treated therapies. As one of the main components, it remains unclear whether ginseng total protein (GP) facilitates recovery from muscle atrophy induced by DEX. Methods: In this study, GP was extracted and purified with Sephadex-G50. C2C12 myoblasts was induced with 2% horse serum to differentiate into C2C12 myotubes. Cell viability was analyzed by the MTT assay, and Ca2+ concentration was analyzed by a flow cytometer. The release of lactic dehydrogenase (LDH) and the glucose consumption were analyzed by spectrophotometry. The phosphorylation of AMP-activated protein kinase (AMPK), phosphoinositide 3-kinase (PI3K), and protein kinase B (Akt) and the expression of glucose transporter 4 (GLUT4) were analyzed by Western blotting. The phosphorylation of AS160 was quantified by Immunofluorescence staining. Results: We found that GP increased cell viability and increased myotube diameter in high-dose DEX-treated C2C12 myotubes for 24 h, but this activity was not found in the enzymatic hydrolyzed GP group. GP reduced muscle atrophy by decreasing the expression of key proteins such as muscle RING-finger protein-1 and muscle atrophy F-box, reducing the Ca2+ concentration, and decreasing the release of LDH in DEX-injured C2C12 myotubes. Moreover, GP improved glucose consumption and increased the phosphorylation of AMPK, PI3K, Akt, and AS160 and the expression of GLUT4 in DEX-treated C2C12 myotubes. Conclusion: The results of this study suggest that GP has effects on recovering DEX-induced muscle atrophy and cell injury, which may improve glucose consumption via the AMPK and PI3K/Akt pathways in high-dose DEX-treated C2C12 myotubes. This study provides in vitro mechanistic insights into the recovery of muscle atrophy with GP treatment.


Assuntos
Glucose/metabolismo , Atrofia Muscular/tratamento farmacológico , Panax/química , Extratos Vegetais/farmacologia , Animais , Dexametasona/toxicidade , Expressão Gênica/efeitos dos fármacos , Transportador de Glucose Tipo 4 , Humanos , Camundongos , Fibras Musculares Esqueléticas/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/patologia , Atrofia Muscular/induzido quimicamente , Atrofia Muscular/patologia , Mioblastos/efeitos dos fármacos , Mioblastos/patologia , Fosforilação/efeitos dos fármacos , Extratos Vegetais/química
6.
J Steroid Biochem Mol Biol ; 193: 105423, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31279004

RESUMO

The active form of Vitamin D (1,25(OH)2D), has been suggested to have a regulatory role in skeletal muscle function and metabolism, however, the effects and mechanisms of vitamin D (VitD) action in this tissue remain to be fully established. In this study, we have used primary human skeletal muscle myoblast (HSMM) cells that display typical characteristics of human skeletal muscle function and protein levels, to investigate the effects of the active form of VitD on proliferation, differentiation, protein synthesis and bioenergetics. Myoblast cells were treated with 100 nM of VitD for 24 h, 48 h, 72 h and five days (cells were differentiated into myotubes) and then analyses were performed. We report that VitD inhibits myoblast proliferation and enhances differentiation by altering the expression of myogenic regulatory factors. In addition, we found that protein synthesis signaling improved in myotubes after VitD treatment in the presence of insulin. We also report an increase in oxygen consumption rate after 24 h of treatment in myoblasts and after 5 days of treatment in myotubes after VitD exposure. VitD significantly impacted HSMM myogenesis, as well as protein synthesis in the presence of insulin.


Assuntos
Fibras Musculares Esqueléticas/efeitos dos fármacos , Mioblastos Esqueléticos/efeitos dos fármacos , Vitamina D/farmacologia , Vitaminas/farmacologia , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Metabolismo Energético/efeitos dos fármacos , Glucose/metabolismo , Humanos , Insulina/farmacologia , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Fibras Musculares Esqueléticas/metabolismo , Proteínas Musculares/metabolismo , Mioblastos Esqueléticos/metabolismo , Consumo de Oxigênio/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo
7.
Biol Pharm Bull ; 42(7): 1128-1133, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31257289

RESUMO

In diabetic patients, skeletal muscle atrophy occurs due to increased oxidative stress and inflammation. Skeletal muscle atrophy reduces the QOL of patients and worsens life prognosis. Therefore, development of preventive therapy for muscle atrophy in hyperglycemic state is eagerly awaited. Juzentaihoto is a medicinal herb that has a function to supplement physical strength, and it is expected to prevent muscle atrophy. To determine the preventive effect of juzentaihoto on muscle atrophy in hyperglycemic state, streptozotocin (STZ) was administered to induce diabetes in mice and the preventive effect of juzentaihoto was evaluated. Mice that received juzentaihoto extract (JTT) showed that the decrease in muscle fiber cross-sectional area in the gastrocnemius muscle was reversed. Additionally, the expression level of tumor necrosis factor α (TNF-α), an inflammatory cytokine, in serum decreased, and that of ubiquitin ligase (atrogin-1, muscle RING-finger protein-1) mRNA in skeletal muscle decreased. An anti-inflammatory cytokine interleukin-10 showed increased levels in the serum and increased levels in spleen cell culture supernatant collected from mice that received JTT. JTT had no effect on the blood glucose level. These results suggest that prophylactic administration of JTT to STZ-induced diabetic mice affects immune cells such as in spleen, causing an anti-inflammatory effect and inhibiting excessive activation of the ubiquitin-proteasome system, to reverse muscle atrophy.


Assuntos
Anti-Inflamatórios/uso terapêutico , Diabetes Mellitus Experimental/tratamento farmacológico , Medicamentos de Ervas Chinesas/uso terapêutico , Atrofia Muscular/tratamento farmacológico , Animais , Anti-Inflamatórios/farmacologia , Glicemia/análise , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/patologia , Medicamentos de Ervas Chinesas/farmacologia , Interleucina-10/sangue , Masculino , Camundongos Endogâmicos ICR , Fibras Musculares Esqueléticas/efeitos dos fármacos , Fibras Musculares Esqueléticas/patologia , Proteínas Musculares/genética , Atrofia Muscular/sangue , Atrofia Muscular/genética , Atrofia Muscular/patologia , Proteínas Ligases SKP Culina F-Box/genética , Proteínas com Motivo Tripartido/genética , Fator de Necrose Tumoral alfa/sangue , Ubiquitina-Proteína Ligases/genética
8.
J Ethnopharmacol ; 242: 112054, 2019 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-31271820

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Ginsenoside Rg3 from Panax ginseng has reported to have multiple pharmacological activities including anti-diabetics, anti-inflammation and anti-cancer. However, the effect of ginsenoside Rg3 on myogenic differentiation and muscle atrophy is unknown. AIM TO THE STUDY: In this study, we investigated the myogenic effect and underlying molecular mechanisms of ginsenoside Rg3 on myotube atrophy induced by tumor necrosis factor-α (TNF-α). MATERIALS AND METHODS: C2C12 myoblasts were induced to differentiate for one day followed by the treatment of TNF-α along with vehicle or ginsenoside Rg3 for additional 2 days and subjected to immunoblotting, immunocytochemistry, quantitative RT-PCR and biochemical analysis for mitochondrial function. RESULTS: Ginsenoside Rg3 promotes myogenic differentiation and multinucleated myotube formation through Akt activation in a dose-dependent manner, without any cytotoxicity. Ginsenoside Rg3 treatment restores myotube formation and increases myotube diameters under TNF-α-treated conditions. Ginsenoside Rg3 enhances Akt/mTOR (mammalian target of rapamycin) signaling that in turn stimulates muscle-specific gene expression such as myosin heavy chain (MHC) and Myogenin, and suppresses the expression of muscle-specific ubiquitin ligases. In addition, ginsenoside Rg3 in TNF-α-treated myotubes significantly inhibits the production of mitochondrial ROS and restores mitochondrial membrane potential (MMP) and ATP contents. Furthermore, ginsenoside Rg3 upregulates the activities and expression of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC1α) and the mitochondrial biogenetic transcription factors, nuclear respiratory factor-1 (NRF1) and mitochondrial transcription factor A (Tfam) in TNF-α-induced myotube atrophy. CONCLUSIONS: This study provides a mechanistic insight into the effect of ginsenoside Rg3 on myogenic differentiation and myotube atrophy, suggesting that ginsenoside Rg3 has a promising potential as a therapeutic or neutraceutical remedy to intervene muscle weakness and atrophy.


Assuntos
Ginsenosídeos/farmacologia , Mitocôndrias Musculares/efeitos dos fármacos , Fibras Musculares Esqueléticas/efeitos dos fármacos , Animais , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Mitocôndrias Musculares/fisiologia , Atrofia Muscular , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Fator de Necrose Tumoral alfa/farmacologia
9.
Nat Commun ; 10(1): 2430, 2019 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-31160583

RESUMO

Muscle loss due to fibrotic or adipogenic replacement of myofibers is common in muscle diseases and muscle-resident fibro/adipogenic precursors (FAPs) are implicated in this process. While FAP-mediated muscle fibrosis is widely studied in muscle diseases, the role of FAPs in adipogenic muscle loss is not well understood. Adipogenic muscle loss is a feature of limb girdle muscular dystrophy 2B (LGMD2B) - a disease caused by mutations in dysferlin. Here we show that FAPs cause the adipogenic loss of dysferlin deficient muscle. Progressive accumulation of Annexin A2 (AnxA2) in the myofiber matrix causes FAP differentiation into adipocytes. Lack of AnxA2 prevents FAP adipogenesis, protecting against adipogenic loss of dysferlinopathic muscle while exogenous AnxA2 enhances muscle loss. Pharmacological inhibition of FAP adipogenesis arrests adipogenic replacement and degeneration of dysferlin-deficient muscle. These results demonstrate the pathogenic role of FAPs in LGMD2B and establish these cells as therapeutic targets to ameliorate muscle loss in patients.


Assuntos
Tecido Adiposo/metabolismo , Fibras Musculares Esqueléticas/metabolismo , Músculo Esquelético/metabolismo , Distrofia Muscular do Cíngulo dos Membros/metabolismo , Células-Tronco/citologia , Adipócitos/patologia , Adipogenia/efeitos dos fármacos , Tecido Adiposo/patologia , Adolescente , Idade de Início , Animais , Anexina A2/metabolismo , Estudos de Casos e Controles , Disferlina/genética , Venenos Elapídicos/toxicidade , Feminino , Fibrose , Humanos , Técnicas In Vitro , Masculino , Camundongos , Fibras Musculares Esqueléticas/efeitos dos fármacos , Fibras Musculares Esqueléticas/patologia , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/patologia , Distrofia Muscular do Cíngulo dos Membros/genética , Distrofia Muscular do Cíngulo dos Membros/patologia , Fenilalanina/análogos & derivados , Fenilalanina/farmacologia , Inibidores de Proteases/farmacologia , Índice de Gravidade de Doença , Células-Tronco/efeitos dos fármacos , Tiofenos/farmacologia , Adulto Jovem
10.
Nutrients ; 11(6)2019 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-31234331

RESUMO

Sarcopoterium spinosum (S. spinosum) is a medicinal plant, traditionally used as an antidiabetic remedy. Previous studies demonstrated its beneficial properties in the treatment of insulin resistance. The aim of this study was to further clarify the effect of S. spinosum extract (SSE) on insulin signaling. Phosphoproteomic analysis, performed in 3T3-L1 adipocytes treated with SSE, revealed the activation of insulin receptor pathways. SSE increased Glut4-facilitated glucose uptake in adipocytes, with an additive effect between SSE and insulin. While the maximal effect of insulin on glucose uptake was found at days 15-16 of differentiation, SSE-induced glucose uptake was found at an earlier stage of differentiation. Inhibition of PI3K and Akt blocked SSE-dependent glucose uptake. Western blot analysis, performed on 3T3-L1 adipocytes and L6 myotubes, showed that in contrast to insulin action, Akt was only marginally phosphorylated by SSE. Furthermore, GSK3ß and PRAS40 phosphorylation as well as glucose uptake were increased by the extract. SSE also induced the phosphorylation of ERK similar to insulin. In conclusion, SSE activates insulin signaling, although the upstream event mediating its effects should be further clarified. Identifying the active molecules in SSE may lead to the development of new agents for the treatment of insulin resistance.


Assuntos
Adipócitos/efeitos dos fármacos , Glucose/metabolismo , Hipoglicemiantes/farmacologia , Insulina/farmacologia , Fibras Musculares Esqueléticas/efeitos dos fármacos , Extratos Vegetais/farmacologia , Rosaceae , Células 3T3-L1 , Adipócitos/metabolismo , Animais , Transportador de Glucose Tipo 4/metabolismo , Glicogênio Sintase Quinase 3 beta/metabolismo , Hipoglicemiantes/isolamento & purificação , Camundongos , Fibras Musculares Esqueléticas/metabolismo , Fosfatidilinositol 3-Quinase/metabolismo , Fosfoproteínas/metabolismo , Fosforilação , Extratos Vegetais/isolamento & purificação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Rosaceae/química , Transdução de Sinais , Fatores de Tempo
11.
J Pharmacol Exp Ther ; 370(2): 219-230, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31189728

RESUMO

Facioscapulohumeral muscular dystrophy (FSHD) is characterized by misexpression of the double homeobox 4 (DUX4) developmental transcription factor in mature skeletal muscle, where it is responsible for muscle degeneration. Preventing expression of DUX4 mRNA is a disease-modifying therapeutic strategy with the potential to halt or reverse the course of disease. We previously reported that agonists of the ß-2 adrenergic receptor suppress DUX4 expression by activating adenylate cyclase to increase cAMP levels. Efforts to further explore this signaling pathway led to the identification of p38 mitogen-activated protein kinase as a major regulator of DUX4 expression. In vitro experiments demonstrate that clinically advanced p38 inhibitors suppress DUX4 expression in FSHD type 1 and 2 myoblasts and differentiating myocytes in vitro with exquisite potency. Individual small interfering RNA-mediated knockdown of either p38α or p38ß suppresses DUX4 expression, demonstrating that each kinase isoform plays a distinct requisite role in activating DUX4 Finally, p38 inhibitors effectively suppress DUX4 expression in a mouse xenograft model of human FSHD gene regulation. These data support the repurposing of existing clinical p38 inhibitors as potential therapeutics for FSHD. The surprise finding that p38α and p38ß isoforms each independently contribute to DUX4 expression offers a unique opportunity to explore the utility of p38 isoform-selective inhibitors to balance efficacy and safety in skeletal muscle. We propose p38 inhibition as a disease-modifying therapeutic strategy for FSHD. SIGNIFICANCE STATEMENT: Facioscapulohumeral muscular dystrophy (FSHD) currently has no treatment options. This work provides evidence that repurposing a clinically advanced p38 inhibitor may provide the first disease-modifying drug for FSHD by suppressing toxic DUX4 expression, the root cause of muscle degeneration in this disease.


Assuntos
Regulação da Expressão Gênica/efeitos dos fármacos , Proteínas de Homeodomínio/genética , Distrofia Muscular Facioescapuloumeral/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Animais , Linhagem Celular , Modelos Animais de Doenças , Camundongos , Fibras Musculares Esqueléticas/efeitos dos fármacos , Fibras Musculares Esqueléticas/metabolismo , Distrofia Muscular Facioescapuloumeral/metabolismo , Distrofia Muscular Facioescapuloumeral/patologia , Mioblastos/efeitos dos fármacos , Mioblastos/metabolismo , Inibidores de Proteínas Quinases/uso terapêutico
12.
Oncol Rep ; 42(2): 479-494, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31233199

RESUMO

Skeletal muscle wasting is a feature of cancer cachexia that increases patient morbidity and mortality. Matrine, the main bioactive component of Sophora flavescens, has been approved for the prevention and therapy of cancer cachexia in China. However, to the best of our knowledge, its mechanism in improving muscle wasting remains unknown. The present study demonstrated that matrine increases muscle fiber size and muscle mass in an in vivo CT26 colon adenocarcinoma cachexia mouse model. Concurrently, other cachexia symptoms, including body and organ weight loss, were alleviated. In in vitro experiments, matrine substantially improved C2C12 myoblast differentiation with or without dexamethasone treatment. In addition, matrine reduced C2C12 myotube atrophy and apoptosis induced by dexamethasone, tumor necrosis factor α and conditioned medium. Two E3 ubiquitin ligases, muscle RING­finger containing protein­1 and muscle atrophy F-box protein, which are specifically expressed in wasting skeletal muscle, were also significantly downregulated (P<0.05) by matrine both in C2C12 myotubes and skeletal muscle. Furthermore, matrine increased the phosphorylation of Akt, mTOR and FoxO3α in the atrophying C2C12 myotube induced by dexamethasone. In conclusion, matrine can alleviate muscle atrophy and improve myoblast differentiation possibly by inhibiting E3 ubiquitin ligases and activating the Akt/mTOR/FoxO3α signaling pathway.


Assuntos
Alcaloides/farmacologia , Caquexia/tratamento farmacológico , Neoplasias do Colo/complicações , Regulação da Expressão Gênica/efeitos dos fármacos , Fibras Musculares Esqueléticas/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Atrofia Muscular/tratamento farmacológico , Quinolizinas/farmacologia , Ubiquitina-Proteína Ligases/antagonistas & inibidores , Animais , Apoptose , Caquexia/etiologia , Caquexia/metabolismo , Proliferação de Células , Neoplasias do Colo/induzido quimicamente , Proteína Forkhead Box O3/genética , Proteína Forkhead Box O3/metabolismo , Humanos , Masculino , Camundongos , Fibras Musculares Esqueléticas/metabolismo , Fibras Musculares Esqueléticas/patologia , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Atrofia Muscular/etiologia , Atrofia Muscular/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Células Tumorais Cultivadas , Fator de Necrose Tumoral alfa/toxicidade
13.
Growth Factors ; 37(1-2): 76-84, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-31215273

RESUMO

To investigate (1) the effect of vascular endothelial growth factor B (VEGFB) on lipid accumulation and the alteration of fatty acids and fatty acid-related enzymes in C2C12 myotubes incubated with fatty acids and (2) the regulatory effect of VEGFB on skeletal muscle lipid metabolism. Mouse C2C12 myotubes were incubated with oleic acid (OA) and palmitic acid (PA), and differentiated mature C2C12 myotubes were treated with VEGFB. Oil-red O staining, BODIPY staining and cell triglycerides (TG) content were examined. Total RNA was isolated, and real-time PCR analysis was performed. Treatment with 100 µM OA and 50 µM PA induced lipid droplet accumulation and increased TG content (p < .01), and 100 ng/mL VEGFB reduced lipid droplet accumulation and decreased TG content (p < .01). Treatment with 100 ng/mL VEGFB significantly induced the mRNA expression of fatty acid transport protein 1 (FATP1) (p < .01) and FATP4 (p < .01). Treatment with 100 ng/mL VEGFB significantly induced the mRNA expression of adipose TG lipase and hormone-sensitive lipase (p < .01) as well as carnitine palmitoyltransferase I (p < .01), peroxisome proliferator-activated receptor-γ coactivator-1α (p < .01), acyl-coa dehydrogenase very long chain (p < .05), acyl-coa synthetase long-chain family member 1 (p < .01), peroxisomal acyl-coenzyme A oxidase 1 (p < .05), and mitochondrial uncoupling protein 3 (p < .01). VEGFB enhanced FATP1and FATP4 expression, promoted C2C12 myotube fatty acid oxidation and TG decomposition, and inhibited C2C12 myotube fatty acid re-esterification, thus inhibiting lipid accumulation in C2C12 myotubes incubated with fatty acids.


Assuntos
Metabolismo dos Lipídeos , Fibras Musculares Esqueléticas/metabolismo , Ácido Oleico/farmacologia , Ácido Palmítico/farmacologia , Fator B de Crescimento do Endotélio Vascular/farmacologia , Animais , Linhagem Celular , Proteínas de Transporte de Ácido Graxo/genética , Proteínas de Transporte de Ácido Graxo/metabolismo , Gotículas Lipídicas/metabolismo , Camundongos , Fibras Musculares Esqueléticas/efeitos dos fármacos , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo
14.
J Anim Sci ; 97(7): 3153-3168, 2019 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-31051033

RESUMO

The objective of this study was to assess how exposure to ergot alkaloids during 2 stages of gestation alters fetal growth, muscle fiber formation, and miRNA expression. Pregnant ewes (n = 36; BW = 83.26 ± 8.14 kg; 4/group; 9 groups) were used in a 2 × 2 factorial arrangement with 2 tall fescue seed treatments [endophyte-infected (E+) vs. endophyte-free (E-)] fed during 2 stages of gestation (MID, days 35 to 85 vs. LATE, days 86 to 133), which created 4 possible treatments (E-/E-, E+/E-, E-/E+, or E+/E+). Ewes were individually fed a total mixed ration containing E+ or E- fescue seed according to treatment assignment. Terminal surgeries were conducted on day 133 of gestation for the collection of fetal measurements and muscle samples. Data were analyzed as a 2 × 2 factorial with fescue treatment, stage of gestation, and 2-way interaction as fixed effects. Fetuses exposed to E+ seed during LATE gestation had reduced (P = 0.0020) fetal BW by 10% compared with E- fetuses; however, fetal body weight did not differ (P = 0.41) with E+ exposure during MID gestation. Fetuses from ewes fed E+ seed during MID and LATE gestation tended to have smaller (P = 0.058) kidney weights compared with E- fetuses. Liver weight was larger (P = 0.0069) in fetuses fed E- during LATE gestation compared with E+. Fetal brain weight did not differ by fescue treatment fed during MID (P = 0.36) or LATE (P = 0.40) gestation. The percentage of brain to empty body weight (EBW) was greater (P = 0.0048) in fetuses from ewes fed E+ fescue seed during LATE gestation, which is indicative of intrauterine growth restriction (IUGR). Primary muscle fiber number was lower (P = 0.0005) in semitendinosus (STN) of fetuses exposed to E+ during MID and/or LATE gestation compared with E-/E-. miRNA sequencing showed differential expression (P < 0.010) of 6 novel miRNAs including bta-miR-652_R+1, mdo-miR-22-3p, bta-miR-1277_R-1, ppy-miR-133a_L+1_1ss5TG, hsa-miR-129-1-3p, and ssc-miR-615 in fetal STN muscle. These miRNA are associated with glucose transport, insulin signaling, intracellular ATP, hypertension, or adipogenesis. This work supports the hypothesis that E+ tall fescue seed fed during late gestation reduces fetal weight and causes asymmetrical growth, which is indicative of IUGR. Changes in primary fiber number and miRNA of STN indicate that exposure to E+ fescue fed during MID and LATE gestation alters fetal muscle development that may affect postnatal muscle growth and meat quality.


Assuntos
Endófitos/fisiologia , Alcaloides de Claviceps/toxicidade , Festuca/química , MicroRNAs/genética , Ovinos/fisiologia , Transcriptoma/efeitos dos fármacos , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/crescimento & desenvolvimento , Ergotaminas/toxicidade , Feminino , Festuca/microbiologia , Desenvolvimento Fetal/efeitos dos fármacos , Peso Fetal/efeitos dos fármacos , Fibras Musculares Esqueléticas/efeitos dos fármacos , Placentação , Gravidez , Sementes/química , Sementes/microbiologia , Ovinos/crescimento & desenvolvimento
15.
Cells ; 8(5)2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-31052442

RESUMO

Glucocorticoids represent some of the most prescribed drugs that are widely used in the treatment of neuromuscular diseases, but their usage leads to side effects such as muscle atrophy. However, different synthetic glucocorticoids can lead to different muscle effects, depending upon its chemical formulation. Here, we intended to demonstrate the muscle histologic and molecular effects of administering different glucocorticoids in equivalency and different dosages. Methods: Seventy male Wistar rats distributed into seven groups received different glucocorticoids in equivalency for ten days or saline solution. The study groups were: Control group (CT) saline solution; dexamethasone (DX) 1.25 or 2.5 mg/kg/day; methylprednisolone (MP) 6.7 or 13.3mg/kg/day; and deflazacort (DC) 10 or 20 mg/kg/day. At the end of the study, the animals were euthanized, and the tibialis anterior and gastrocnemius muscles were collected for metachromatic ATPase (Cross-sectional area (CSA) measurement), Western blotting (protein expression of IGF-1 and Ras/Raf/MEK/ERK pathways) and RT-PCR (MYOSTATIN, MuRF-1, Atrogin-1, REDD-1, REDD-2, MYOD, MYOG and IRS1/2 genes expression) experiments. Results: Muscle atrophy occurred preferentially in type 2B fibers in all glucocorticoid treated groups. DC on 10 mg/kg/day was less harmful to type 2B fibers CSA than other doses and types of synthetic glucocorticoids. In type 1 fibers CSA, lower doses of DC and DX were more harmful than high doses. DX had a greater effect on the IGF-1 pathway than other glucocorticoids. MP more significantly affected P-ERK1/2 expression, muscle fiber switching (fast-to-slow), and expression of REDD1 and MyoD genes than other glucocorticoids. Compared to DX and MP, DC had less of an effect on the expression of atrogenes (MURF-1 and Atrogin-1) despite increased MYOSTATIN and decreased IRS-2 genes expression. Conclusions: Different glucocorticoids appears to cause muscle atrophy affecting secondarily different signaling mechanisms. MP is more likely to affect body/muscles mass, MEK/ERK pathway and fiber type transition, DX the IGF-1 pathway and IRS1/2 expression. DC had the smallest effect on muscle atrophic response possibly due a delayed timing on atrogenes response.


Assuntos
Dexametasona/farmacologia , Metilprednisolona/farmacologia , Músculo Esquelético/efeitos dos fármacos , Pregnenodionas/farmacologia , Animais , Peso Corporal/efeitos dos fármacos , Dexametasona/administração & dosagem , Regulação da Expressão Gênica/efeitos dos fármacos , Glucocorticoides/administração & dosagem , Glucocorticoides/farmacologia , Proteínas Substratos do Receptor de Insulina/genética , Proteínas Substratos do Receptor de Insulina/metabolismo , Fator de Crescimento Insulin-Like I/genética , Fator de Crescimento Insulin-Like I/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Metilprednisolona/administração & dosagem , Desenvolvimento Muscular/efeitos dos fármacos , Desenvolvimento Muscular/genética , Fibras Musculares Esqueléticas/efeitos dos fármacos , Tamanho do Órgão/efeitos dos fármacos , Pregnenodionas/administração & dosagem , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos Wistar
16.
Meat Sci ; 155: 27-35, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31059939

RESUMO

The objective of the present experiment was to evaluate the effects of encapsuled active principles (eugenol, thymol and vanillin blend), and clove and rosemary essential oils inclusion into the finishing diets of Nellore heifers on chemical composition, collagen content, fatty acid profile and structural traits (fibers types, type I and III collagen and sarcomere length) of longissimus muscle. Treatments had no effect (P > .05) on type of fiber, the meat chemical composition or in the muscle fatty acid profile. However, the diet with clove and rosemary essential oil and the active principle blend led to an increase in sarcomere length, higher soluble collagen content and a lower amount of type III collagen (P < .05). The mixture of both active principles and essential oils clove and cinnamon essential oil, have a potential use in animal feed, favoring a greater sarcomere length, that is directly related to the increase of the meat tenderness, without altering the meat chemical composition or fatty acid profile.


Assuntos
Ração Animal/análise , Colágeno/análise , Ácidos Graxos/análise , Óleos Voláteis/farmacologia , Carne Vermelha/análise , Animais , Benzaldeídos/farmacologia , Bovinos , Dieta/veterinária , Eugenol/farmacologia , Feminino , Fibras Musculares Esqueléticas/efeitos dos fármacos , Sarcômeros/efeitos dos fármacos , Syzygium , Timol/farmacologia
17.
Biomed Pharmacother ; 115: 108930, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31055234

RESUMO

Backgroud Icariin, a major bioactive pharmaceutical component of the Chinese herbal medicine Epimedii Herba, has demonstrated lipid-lowering and anti-obesity effects. Irisin/ fibronectin type III domain-containing 5 (FNDC5) protects against obesity by inducing browning in white adipose tissue. Objectives This study investigated the effects of icariin on irisin/FNDC5 expression in C2C12 myotubes. Method Cultured murine C2C12 myocytes were used to study the effects of icariin on irisin/FNDC5 expressions by Western-blot, qPCR, Elisa and Immunofluorescence. We also investigated FNDC5 expression in icariin-treated intact mice. Results Icariin increased irisin/FNDC5 protein levels. mRNA levels of irisin/FNDC5 were also increased in C2C12 myocytes after treatment with icariin. Icariin increased peroxisome proliferator-activated receptor gamma co-activator 1alpha (PGC-1α) protein and mRNA levels. Additionally, icariin exposure resulted in phosphorylation of AMP-activated protein kinase (AMPK) in a dose-dependent manner. The regulatory effect of icariin on FNDC5 protein expression was blocked by the AMPK antagonist compound C or silencing of AMPK, suggesting that icariin increased FNDC5 protein expression via the AMPK pathway. In vivo, icariin decreased body weight gain in C57BL/6 mice and increased FNDC5, PGC-1α, and p-AMPK expression levels in skeletal muscle. Conclusions Taken together, our results indicated that icariin induces irisin/FNDC5 expression via the AMPK pathway, indicating that icariin may be promising as an anti-obesity drug.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Fibronectinas/genética , Flavonoides/farmacologia , Fibras Musculares Esqueléticas/efeitos dos fármacos , Animais , Técnicas de Cultura de Células , Linhagem Celular , Relação Dose-Resposta a Droga , Medicamentos de Ervas Chinesas , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fibras Musculares Esqueléticas/metabolismo , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Regulação para Cima
18.
Mar Drugs ; 17(5)2019 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-31083497

RESUMO

Dexamethasone (DEX), a synthetic glucocorticoid, causes skeletal muscle atrophy. This study examined the protective effects of Pyropia yezoensis peptide (PYP15) against DEX-induced myotube atrophy and its association with insulin-like growth factor-I (IGF-I) and the Akt/mammalian target of rapamycin (mTOR)-forkhead box O (FoxO) signaling pathway. To elucidate the molecular mechanisms underlying the effects of PYP15 on DEX-induced myotube atrophy, C2C12 myotubes were treated for 24 h with 100 µM DEX in the presence or absence of 500 ng/mL PYP15. Cell viability assays revealed no PYP15 toxicity in C2C12 myotubes. PYP15 activated the insulin-like growth factor-I receptor (IGF-IR) and Akt-mTORC1 signaling pathway in DEX-induced myotube atrophy. In addition, PYP15 markedly downregulated the nuclear translocation of transcription factors FoxO1 and FoxO3a, and inhibited 20S proteasome activity. Furthermore, PYP15 inhibited the autophagy-lysosomal pathway in DEX-stimulated myotube atrophy. Our findings suggest that PYP15 treatment protected against myotube atrophy by regulating IGF-I and the Akt-mTORC1-FoxO signaling pathway in skeletal muscle. Therefore, PYP15 treatment appears to exert protective effects against skeletal muscle atrophy.


Assuntos
Dexametasona/toxicidade , Fibras Musculares Esqueléticas/efeitos dos fármacos , Atrofia Muscular/tratamento farmacológico , Peptídeos/farmacologia , Proteínas de Plantas/farmacologia , Rodófitas/química , Animais , Autofagia/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Dexametasona/farmacologia , Proteínas Substratos do Receptor de Insulina/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Lisossomos/metabolismo , Camundongos , Fibras Musculares Esqueléticas/metabolismo , Fibras Musculares Esqueléticas/patologia , Músculo Esquelético/efeitos dos fármacos , Atrofia Muscular/induzido quimicamente , Atrofia Muscular/metabolismo , Atrofia Muscular/patologia , Peptídeos/química , Proteínas de Plantas/química , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo
19.
Food Chem Toxicol ; 129: 337-343, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31071387

RESUMO

This study assesses the ability of anthraquinone derivative, 2-methyl-1,3,6-trihydroxy-9,10-anthraquinone (MTAQ) to decrease postprandial hyperglycemia or enhance glucose uptake and to elucidate the underlying molecular mechanism. We investigated α-glucosidase inhibition, glucose uptake, and translocation of glucose transporter 4 (GLUT4) in C2C12 myotubes. The data indicate that MTAQ strongly inhibited α-glucosidase activity in a concentration-dependent manner, with an IC50 value of 6.49 ±â€¯1.31 µM, and functioned as a reversible competitive inhibitor, with a dissociation constant of 41.88 µM. Moreover, MTAQ significantly augmented basal and insulin-stimulated glucose uptake as well as translocation of GLUT4 to the plasma membrane. It also stimulated the phosphorylation of insulin receptor ß isoform, insulin receptor substrate-1,3-phosphoinositide-dependent protein kinase 1, and protein kinase B (AKT). A pretreatment with an AKT inhibitor, LY294002, attenuated the ability of MTAQ to activate an insulin-like signaling pathway and to enhance basal and insulin-stimulated glucose uptake and stimulate GLUT4 translocation to the plasma membrane. These findings reveal the fact that MTAQ may have potential for the development of new antidiabetic drugs to manage blood glucose levels.


Assuntos
Antraquinonas/farmacologia , Glucose/metabolismo , Inibidores de Glicosídeo Hidrolases/farmacologia , Insulina/metabolismo , Fibras Musculares Esqueléticas/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Animais , Linhagem Celular , Transportador de Glucose Tipo 4/metabolismo , Hipoglicemiantes/farmacologia , Cinética , Camundongos , Fibras Musculares Esqueléticas/metabolismo , Transporte Proteico
20.
Food Funct ; 10(6): 3334-3343, 2019 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-31095141

RESUMO

This study was conducted to investigate the effect and underlying mechanism of Resveratrol (RES) in regulating skeletal muscle fiber-type switching. We found that RES had no effect on the body weight and food intake of Kunming mice (KM mice) that were orally administered with 400 mg kg-1 d-1 RES for 12 weeks. Notably, the RES administration significantly increased the expression of myosin heavy chain (MyHC) 1, MyHC2a, and MyHC2x in the extensor digitorum longus (EDL) and soleus (SOL) muscles. Furthermore, the muscle immunostaining of the results showed that the RES treatment led to the myofiber type transition from glycolytic to oxidative in muscles. The mRNA and protein levels of the adiponectin receptor (AdipoR), AMP-activated protein kinase (AMPK), peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) in EDL and SOL were drastically increased after RES treatment. Moreover, the plasma Adiponectin (AdipoQ) protein levels were higher in the RES-treated mice compared to the control mice. Moreover, the in vitro results further demonstrated that the 20 µM RES treatment increased the expression of AdipoR1, AdipoR2, AMPK, PGC-1α and MyHC1, but decreased the expression of MyHC2b in C2C12 myoblasts. Furthermore, mechanistic studies revealed that silencing the AdiopR1, not the AdiopR2, abolished the effect of RES on the expression of AMPK and PGC-1α in the C2C12 cells. These results indicated that RES could regulate skeletal fiber switching through the AdiopR1-AMPK-PGC-1α pathway. This work may provide a new strategy for enhancing endurance and relieving muscle diseases caused by oxidative muscle fiber deficiency.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Fibras Musculares Esqueléticas/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Receptores de Adiponectina/metabolismo , Resveratrol/administração & dosagem , Proteínas Quinases Ativadas por AMP/genética , Adiponectina/sangue , Animais , Masculino , Camundongos , Fibras Musculares Esqueléticas/efeitos dos fármacos , Fibras Musculares Esqueléticas/enzimologia , Mioblastos/efeitos dos fármacos , Mioblastos/metabolismo , Cadeias Pesadas de Miosina/genética , Cadeias Pesadas de Miosina/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Receptores de Adiponectina/genética , Transdução de Sinais/efeitos dos fármacos
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