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1.
Article in English | WPRIM | ID: wpr-880615

ABSTRACT

OBJECTIVES@#To study the gene expression of adipose tissue CD14@*METHODS@#The data of GSE54350 were obtained from the public database of gene expression profiling. The data were pre-processed by Network Analyst, String 11.0, Cytoscape 3.7.1, and other analytical software. The differentially expressed genes were analyzed by gene ontology biological function and kyoto encycopedia of genes and genomes (KEGG) signaling pathway to establish differential gene protein interaction network, transcription factor-gene regulatory network, microRNA-gene regulatory network, environmental factors-gene regulatory network, and other interaction systems.@*RESULTS@#The gene expression pattern of CD14@*CONCLUSIONS@#The gene expression of adipose tissue CD14


Subject(s)
Adipose Tissue , Computational Biology , DNA-Binding Proteins , Diabetes Mellitus, Type 2/genetics , Gene Expression , Gene Expression Profiling , Gene Regulatory Networks , Humans , MicroRNAs/genetics , Muscle Proteins
2.
Article in English | WPRIM | ID: wpr-878450

ABSTRACT

OBJECTIVES@#This study aims to investigate the effect of the regulator of G-protein signaling 2 (RGS2) on the proliferation and invasion of oral squamous cell carcinoma (OSCC) cells and its potential molecular mechanism. Metho⁃ds The expression status and clinical significance of RGS2 in head and neck squamous cell carcinomas and matched adjacent normal tissues were evaluated using TCGA database. Three OSCC cell lines (i.e., SCC-9, Cal27, and Fadu) were overexpressed with RGS2, and the effect of RGS2 on cell proliferation and invasion was determined using the Transwell, clone formation, and cell counting kit (CCK)-8 assays. Moreover, the yeast two-hybrid scree-ning and co-immunoprecipitation (Co-IP) assays were conducted to detect the correlation of RGS2, four and a half LIM domains protein 1 (FHL1), and damage DNA-binding protein 1 (DDB1).@*RESULTS@#The expression level of RGS2 in OSCC was significantly lower than that in matched adjacent normal tissues (@*CONCLUSIONS@#RGS2 plays an important role in the inhibition of OSCC proliferation and invasion. The structure stability of RGS2 is competitively regulated by FHL1 and DDB1.


Subject(s)
Carcinoma, Squamous Cell , Cell Line, Tumor , Cell Movement , Cell Proliferation , GTP-Binding Proteins , Head and Neck Neoplasms , Humans , Intracellular Signaling Peptides and Proteins , LIM Domain Proteins , Mouth Neoplasms , Muscle Proteins , Squamous Cell Carcinoma of Head and Neck
3.
Acta Physiologica Sinica ; (6): 82-88, 2021.
Article in Chinese | WPRIM | ID: wpr-878238

ABSTRACT

The research on the molecular mechanism of vascular injury has been a hot topic in recent years since the mechanism can be targeted for the treatment of vascular injury diseases. A large number of studies have found that vascular injury, repair and pathological remodeling are closely related to phenotype switching, abnormal proliferation and migration, and apoptosis of vascular smooth muscle cells (VSMCs). Smooth muscle 22α (SM22α) is a shape change and transformation sensitive F-actin-binding protein. SM22α decorates the contractile filament bundles within cultured VSMCs exhibiting differentiated phenotypes. In addition, SM22α is involved in regulation of cell signaling pathways related to vascular homeostasis and vascular remodeling. Here, we reviewed the recent research progress of SM22α in vascular homeostasis and remodeling.


Subject(s)
Cell Proliferation , Cells, Cultured , Homeostasis , Humans , Muscle Proteins , Muscle, Smooth, Vascular , Myocytes, Smooth Muscle , Phenotype , Vascular Remodeling
4.
Electron. j. biotechnol ; 39: 52-60, may. 2019. ilus, tab, graf
Article in English | LILACS | ID: biblio-1052027

ABSTRACT

BACKGROUND: Biologically active peptides produced from fish wastes are gaining attention because their health benefits. Proteases produced by halophilic microorganisms are considered as a source of active enzymes in high salt systems like fish residues. Hence, the aim of this study was the bioprospection of halophilic microorganisms for the production of proteases to prove their application for peptide production. RESULTS: Halophilic microorganisms were isolated from saline soils of Mexico and Bolivia. An enzymatic screening was carried out for the detection of lipases, esterases, pHB depolymerases, chitinases, and proteases. Most of the strains were able to produce lipases, esterases, and proteases, and larger hydrolysis halos were detected for protease activity. Halobacillus andaensis was selected to be studied for proteolytic activity production; the microorganism was able to grow on gelatin, yeast extract, skim milk, casein, peptone, fish muscle (Cyprinus carpio), and soy flour as protein sources, and among these sources, fish muscle protein was the best inducer of proteolytic activity, achieving a protease production of 571 U/mL. The extracellular protease was active at 50°C, pH 8, and 1.4 M NaCl and was inhibited by phenylmethylsulfonyl fluoride. The proteolytic activity of H. andaensis was used to hydrolyze fish muscle protein for peptide production. The peptides obtained showed a MW of 5.3 kDa and a radical scavenging ability of 10 to 30% on 2,2-diphenyl-1-picrylhydrazyl and 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) and a ferric reducing ability of plasma. Conclusion: The use of noncommercial extracellular protease produced by H. andaensis for biologically active peptide production using fish muscle as the protein source presents a great opportunity for high-value peptide production.


Subject(s)
Peptide Hydrolases/metabolism , Peptides/metabolism , Fish Proteins/metabolism , Halobacillus/enzymology , Soil , Bacteria/isolation & purification , Bolivia , Esterases , Salinity , Hydrolysis , Lipase , Mexico , Muscle Proteins , Antioxidants
6.
Article in English | WPRIM | ID: wpr-741698

ABSTRACT

BACKGROUND/OBJECTIVES: Successful recovery of an animal from exercise is essential, especially prior to the next exercise session. This study was conducted to find an effective exercise-to-rest period ratio for the restoration of energy sources and replenishment of anti-oxidative status in tissue after exercise. MATERIALS/METHODS: Thirty-two rats were assigned to either non-training or training exercise groups for 5 weeks. After that period, the two groups were subdivided into four smaller groups: non-exercise (NE), exercise 0.5 hour and rest 1 hour (ER0.5:1), exercise 1 hour and rest 1 hour (ER1:1), exercise 2 hours and rest 1 hour (ER2:1). RESULTS: In the training group animals and compared to the NE group, the levels of plasma glucose after the rest period were significantly high in all ER groups but highest in the ER2:1 group. Similarly, the liver glycogen level was highest in the ER2:1 group. The plasma FFA level reached the highest level in the ER2:1 group but was similarly high in the ER0.5:1 group. Liver TG level was unchanged in the ER2:1 and ER1:1 groups but was significantly high in the ER0.5:1 group. Muscle TG levels were decreased in all three ER groups. Plasma protein levels were significantly high in the ER2:1 and ER0.5:1 groups. In both training animal and non-training animals, the liver protein levels did not change significantly between the NE and ER groups, irrespective of the exercise-to-rest ratio. In the training animal group, muscle protein level was significantly low in the ER2:1 and ER0.5:1 groups. The activity levels of superoxide dismutase and catalase, as well as the malondialdehyde concentration, were not significantly different between NE and ER groups, irrespective of the exercise-to-rest period ratio. CONCLUSIONS: These results indicate that animals provided with a 0.5:1 to 1:1 exercise-to-rest period ratio can restore their muscle energy sources and recover their anti-oxidative defense system.


Subject(s)
Animals , Blood Glucose , Catalase , Liver , Liver Glycogen , Malondialdehyde , Muscle Proteins , Plasma , Rats , Superoxide Dismutase
7.
Einstein (Säo Paulo) ; 17(3): eRB4898, 2019.
Article in English | LILACS | ID: biblio-1019802

ABSTRACT

ABSTRACT Alongside a proper diet, ergogenic aids with potential direct and/or indirect physical performance enhancing effects are sought after for improved adaptation to physical training. Nutritional ergogenics include diet composition changes and/or dietary supplementation. Branched-chain amino acids valine, leucine and isoleucine are widely popular among products with ergogenic claims. Their major marketing appeal derives from allegations that branched-chain amino acids intake combined with resistance physical exercise stimulates muscle protein synthesis. Evidence supporting the efficacy of branched-chain amino acids alone for muscle hypertrophy in humans is somewhat equivocal. This brief review describes physiological and biochemical mechanisms underpinning the effects of complete protein source and branched-chain amino acid intake on skeletal muscle growth in the postabsorptive and post-exercise state. Evidence in favor of or against potential anabolic effects of isolated branched-chain amino acid intake on muscle protein synthesis in humans is also examined.


RESUMO No treinamento físico, buscam-se, além de uma dieta adequada, recursos ergogênicos que possam maximizar direta e/ou indiretamente o desempenho físico. Entre as categorias de recursos ergogênicos, o nutricional compreende a modulação da composição dietética e/ou uso de suplementação. A comercialização dos suplementos de aminoácidos de cadeia ramificada valina, leucina e isoleucina possui muita popularidade entre aqueles com alegação ergogênica. O principal marketing está na afirmação de que o consumo isolado de aminoácidos de cadeia ramificada associado ao exercício físico resistido estimula a síntese de proteína muscular. As evidências da eficácia da ingestão isolada de aminoácidos de cadeia ramificada para a hipertrofia muscular em humanos parecem equivocadas. Nesta breve revisão, apresentamos a compreensão fisiológica e bioquímica de como a ingestão de uma fonte completa de proteína e de aminoácidos de cadeia ramificada afeta o crescimento do músculo esquelético no estado pós-absortivo e pós-exercício. Mostramos também as evidências que suportam ou não a afirmação dos potenciais efeitos anabólicos na síntese de proteína muscular dos aminoácidos de cadeia ramificada quando consumidos isoladamente em humanos.


Subject(s)
Humans , Amino Acids, Branched-Chain/metabolism , Muscle Proteins/biosynthesis , Exercise/physiology , Muscle, Skeletal/metabolism , Postprandial Period/drug effects , Dietary Supplements , Gastrointestinal Absorption/drug effects , Amino Acids, Branched-Chain/physiology
8.
Medwave ; 19(5): e7645, 2019.
Article in English, Spanish | LILACS | ID: biblio-1005855

ABSTRACT

INTRODUCCIÓN Los síndromes miasténicos congénitos son un grupo heterogéneo de desórdenes genéticos, caracterizados por una transmisión sináptica anormal en la placa neuromuscular. REPORTE Presentamos el caso de un paciente de dos años, varón, con hipotonía, ptosis palpebral y debilidad simétrica y de predominio proximal, características que aparecieron desde el nacimiento y que motivaron varias hospitalizaciones por neumonía e insuficiencia ventilatoria. Desde el inicio de la deambulación a los dos años, los padres notaron que la debilidad empeoraba por las tardes y con la actividad física repetida o prolongada. El examen físico a los dos años mostró ptosis palpebral, debilidad de predominio proximal y fatigabilidad con el esfuerzo sostenido. La electro-miografía evidenció decremento del 27% en el potencial de acción muscular compuesto. El análisis de tríos mostró heterocigosis compuesta por transmisión de dos mutaciones diferentes en el gen de rapsina, una ya conocida procedente del padre y la otra no reportada previa-mente, procedente de la madre. El paciente recibió piridostigmina obteniendo mejoría inmediata y logrando un desempeño óptimo en actividades escolares, deportivas y de la vida cotidiana. A la fecha, no ha presentado nuevos episodios de insuficiencia ventilatoria. CONCLUSIONES La debilidad de inicio neonatal y la fatigabilidad o agotamiento con el esfuerzo sostenido, con afección principalmente de los músculos con inervación troncal y con un decremento mayor al 10% en el potencial de acción muscular compuesto en la electromiografía, deben hacer sospechar en un síndrome miasténico congénito. Se revisan los puntos clínicos clave que permiten establecer el diagnóstico oportuno y las opciones de tratamiento efectivo para algunos de estos síndromes.


INTRODUCTION The congenital myasthenic syndromes are a heterogeneous group of genetic disorders characterized by an abnormal synaptic transmission in the neuromuscular plate. REPORT We present a two-year-old patient, male, with hypotonia, palpebral ptosis, and proximal symmetric weakness with a neonatal onset that motivated several and prolonged hospitalizations for pneumonia and respiratory failure. From two years of age, the parents noticed that the facial and general weakness worsened in the afternoons and with repeated or prolonged physical activity. The physical examination showed palpebral ptosis, predominantly proximal weakness, and fatigability with sustained muscular effort. The electromyography showed a 27% decrement in the Compound Muscular Action Potential and the case-parents genetic study showed compound heterozygosity with the transmission of two different mutations in the rapsyn gene from both parents. The patient received pyridostigmine with great improvement, achieving optimal performance in school, sports, and daily life activities. CONCLUSIONS Weakness and fatigability with neonatal onset, mainly affecting the muscles with brain stem innervation and the decrement greater than 10 percent in the Compound Muscular Action Potential in the electromyographic studies, should make us suspect in a congenital myasthenic syndrome. We review the literature and key clinical points to establish a timely diagnosis and effective treatment in some of these syndromes.


Subject(s)
Humans , Male , Child, Preschool , Pyridostigmine Bromide/administration & dosage , Myasthenic Syndromes, Congenital/diagnosis , Muscle Proteins/genetics , Cholinesterase Inhibitors/administration & dosage , Myasthenic Syndromes, Congenital/genetics , Myasthenic Syndromes, Congenital/drug therapy , Mutation
9.
Braz. j. med. biol. res ; 52(9): e8551, 2019. graf
Article in English | LILACS | ID: biblio-1019565

ABSTRACT

Fibroblasts are a highly heterogeneous population of cells, being found in a large number of different tissues. These cells produce the extracellular matrix, which is essential to preserve structural integrity of connective tissues. Fibroblasts are frequently engaged in migration and remodeling, exerting traction forces in the extracellular matrix, which is crucial for matrix deposition and wound healing. In addition, previous studies performed on primary myoblasts suggest that the E3 ligase MuRF2 might function as a cytoskeleton adaptor. Here, we hypothesized that MuRF2 also plays a functional role in skeletal muscle fibroblasts. We found that skeletal muscle fibroblasts express MuRF2 and its siRNA knock-down promoted decreased fibroblast migration, cell border accumulation of polymerized actin, and down-regulation of the phospho-Akt expression. Our results indicated that MuRF2 was necessary to maintain the actin cytoskeleton functionality in skeletal muscle fibroblasts via Akt activity and exerted an important role in extracellular matrix remodeling in the skeletal muscle tissue.


Subject(s)
Animals , Rats , Cell Differentiation/physiology , Muscle, Skeletal/physiology , Ubiquitin-Protein Ligases/physiology , Cell Proliferation/physiology , Fibroblasts/physiology , Muscle Proteins/physiology , Blotting, Western , Fluorescent Antibody Technique , Muscle, Skeletal/metabolism , Ubiquitin-Protein Ligases/metabolism , Fibroblasts/metabolism , Muscle Proteins/metabolism
10.
Article in Chinese | WPRIM | ID: wpr-776525

ABSTRACT

OBJECTIVE@#To investigate the therapeutic effects of massage on denervated skeletal muscle atrophy in rats and its mechanism.@*METHODS@#Forty-eight male SD rats were randomly divided into model group (n=24) and massage group (n=24). Gastrocnemius muscle atrophy model was established by transecting the right tibial nerve of rat. On the second day after operation, the gastrocnemius muscle of the rats in the massage group was given manual intervention and the model group was not intervened. Six rats were sacrificed at the four time points of 0 d, 7 d, 14 d and 21 d. The gastrocnemius of the rats were obtained and measured the wet mass ratio after weighing. Cross-sectional area and diameter of the muscle fiber were measured after HE staining. The relative expressions of miR-23a, Akt, MuRF1 and MAFbx mRNA were tested with qPCR.@*RESULTS@#Compared with 0 d, the wet weight ratio, cross-sectional area and diameter of gastrocnemius muscle showed a progressive decline in the model group and massage group. The wet weight ratio, cross-sectional area and diameter of gastrocnemius muscle in the massage group were higher than those in the model group on 7 d, 14 d and 21 d (P<0.05, P<0.01). Compared with 0 d, the expressions of MuRF1, MAFbx and Akt mRNA were increased first and then were decreased in the model group and massage group. The expression of MuRF1 mRNA in massage group was lower than that in model group on 7 d and 21 d (P<0.05, P<0.01). The expression of MAFbx mRNA in massage group was lower than that in model group on 7 d, 14 d and 21 d (P<0.01, P<0.05, P<0.01). The expression of Akt mRNA in massage group was higher than that in model group on 7 d, 14 d and 21 d (P<0.05, P<0.01). Compared with 0 d, the expression of miR-23a mRNA was increased in the model group and massage group on 21 d, and the expression of miR-23a mRNA in massage group was higher than that in model group (P< 0.05).@*CONCLUSION@#Massage can delay the atrophy of denervated skeletal muscle. The mechanism may be related to up-regulation of the expression of miR-23a and Akt mRNA, down-regulation of the expressions of MuRF1 and MAFbx mRNA, inhibition of protein degradation rate, and reduction of skeletal muscle protein degradation.


Subject(s)
Animals , Male , Massage , MicroRNAs , Metabolism , Muscle Fibers, Skeletal , Muscle Proteins , Metabolism , Muscle, Skeletal , Muscular Atrophy , Therapeutics , Proto-Oncogene Proteins c-akt , Metabolism , Rats , Rats, Sprague-Dawley , SKP Cullin F-Box Protein Ligases , Metabolism , Tripartite Motif Proteins , Metabolism , Ubiquitin-Protein Ligases , Metabolism
11.
Protein & Cell ; (12): 693-716, 2018.
Article in English | WPRIM | ID: wpr-756928

ABSTRACT

Hypertonia is a neurological dysfunction associated with a number of central nervous system disorders, including cerebral palsy, Parkinson's disease, dystonia, and epilepsy. Genetic studies have identified a homozygous truncation mutation in Trak1 that causes hypertonia in mice. Moreover, elevated Trak1 protein expression is associated with several types of cancers and variants in Trak1 are linked to childhood absence epilepsy in humans. Despite the importance of Trak1 in health and disease, the mechanisms of Trak1 action remain unclear and the pathogenic effects of Trak1 mutation are unknown. Here we report that Trak1 has a crucial function in regulation of mitochondrial fusion. Depletion of Trak1 inhibits mitochondrial fusion, resulting in mitochondrial fragmentation, whereas overexpression of Trak1 elongates and enlarges mitochondria. Our analyses revealed that Trak1 interacts and colocalizes with mitofusins on the outer mitochondrial membrane and functions with mitofusins to promote mitochondrial tethering and fusion. Furthermore, Trak1 is required for stress-induced mitochondrial hyperfusion and pro-survival response. We found that hypertonia-associated mutation impairs Trak1 mitochondrial localization and its ability to facilitate mitochondrial tethering and fusion. Our findings uncover a novel function of Trak1 as a regulator of mitochondrial fusion and provide evidence linking dysregulated mitochondrial dynamics to hypertonia pathogenesis.


Subject(s)
Adaptor Proteins, Vesicular Transport , Metabolism , Animals , HeLa Cells , Humans , Membrane Fusion , Mice , Mitochondria , Metabolism , Mitochondrial Proteins , Metabolism , Muscle Proteins , Metabolism , Tumor Cells, Cultured
12.
Article in Chinese | WPRIM | ID: wpr-813168

ABSTRACT

To validate the expressions of G protein-coupled receptor 81 (GPR81), monocarboxylate transporter (MCT) 1 and MCT4 in cervical squamous carcinoma and to explore their role in the onset of cervical squamous carcinoma.
 Methods: Immunohistochemical method was used to detect the expressions of GPR81, MCT1 and MCT4 in 16 normal cervical tissue and 44 cervical squamous carcinoma tissue. The associations of these proteins expression with cervical squamous carcinoma or clinicopathological factors were analyzed.
 Results: The expressions of GPR81, MCT1 and MCT4 in cervical squamous carcinoma tissue were higher than those in normal cervical tissue (P0.05). No difference of the expressions of GPR81, MCT1 and MCT4 were found between cases with or without lymphatic metastasis (P>0.05). No correlation was found among GPR81, MCT1 and MCT4 in cervical squamous carcinoma (P>0.05).
 Conclusion: GPR81, MCT1 and MCT4 may be associated with the onset of cervical squamous carcinoma, and GPR81 may be associated with the progression of cervical squamous carcinoma.


Subject(s)
Carcinoma, Squamous Cell , Genetics , Disease Progression , Female , Gene Expression Regulation, Neoplastic , Humans , Monocarboxylic Acid Transporters , Genetics , Muscle Proteins , Genetics , Receptors, G-Protein-Coupled , Genetics , Symporters , Genetics , Uterine Cervical Neoplasms , Genetics
13.
Article in English | WPRIM | ID: wpr-107082

ABSTRACT

BACKGROUND: Menopause contributes to an increase in visceral fat mass and a decrease in muscle protein synthesis. Therefore, we performed this study to examine their relationship how effect the changes of body composition as obesity and sarcopenia on metabolic syndrome (MS) as a predictor of cardiovascular disease in postmenopausal women. METHODS: Using data from the Korean National Health and Nutrition Examination Survey (KNHANES) from 2008 to 2011, we estimated that 4,183 postmenopausal women underwent dual energy X-ray absorptiometry scans. Sarcopenia was defined as an appendicular skeletal muscle mass divided by body weight that was less than 1 standard deviation below the sex specific mean for the young reference group. After classification into four groups, the results were adjusted with menopausal age and hormonal treatment. The relationship between sarcopenic obesity (SO) and MS in postmenopausal women was analyzed by logistic regression analysis in a complex sampling. RESULTS: In an unadjusted model, the odds ratio (OR) of MS for sarcopenia was 1.94 (95% confidence interval [CI], 1.52-2.49); the obesity group had an OR of 4.55 (95% CI, 3.63-5.71); and distinctly, the SO group had an OR of 6.26 (95% CI, 5.10-7.70). Even though there was controlling for variable adjustment, no definite difference was seen in the results. CONCLUSIONS: Sarcopenia and obesity were associated with MS independent of other metabolic impairment risk factors in both early menopausal and postmenopausal women. The results showed that, in particular, the prevalence of MS has increased more in postmenopausal women compared with previous research.


Subject(s)
Absorptiometry, Photon , Body Composition , Body Weight , Cardiovascular Diseases , Classification , Cross-Sectional Studies , Female , Humans , Intra-Abdominal Fat , Logistic Models , Menopause , Metabolic Syndrome , Muscle Proteins , Muscle, Skeletal , Nutrition Surveys , Obesity , Odds Ratio , Prevalence , Risk Factors , Sarcopenia
14.
Article in English | WPRIM | ID: wpr-85458

ABSTRACT

Proteasomes are the primary degradation machinery for oxidatively damaged proteins that compose a class of misfolded protein substrates. Cellular levels of reactive oxygen species increase with age and this cellular propensity is particularly harmful when combined with the age-associated development of various human disorders including cancer, neurodegenerative disease and muscle atrophy. Proteasome activity is reportedly downregulated in these disease conditions. Herein, we report that docosahexaenoic acid (DHA), a major dietary omega-3 polyunsaturated fatty acid, mediates intermolecular protein cross-linkages through oxidation, and the resulting protein aggregates potently reduce proteasomal activity both in vitro and in cultured cells. Cellular models overexpressing aggregation-prone proteins such as tau showed significantly elevated levels of tau aggregates and total ubiquitin conjugates in the presence of DHA, thereby reflecting suppressed proteasome activity. Strong synergetic cytotoxicity was observed when the cells overexpressing tau were simultaneously treated with DHA. Antioxidant N-acetyl cysteine significantly desensitized the cells to DHA-induced oxidative stress. DHA significantly delayed the proteasomal degradation of muscle proteins in a cellular atrophy model. Thus, the results of our study identified DHA as a potent inducer of cellular protein aggregates that inhibit proteasome activity and potentially delay systemic muscle protein degradation in certain pathologic conditions.


Subject(s)
Atrophy , Cells, Cultured , Cysteine , Humans , In Vitro Techniques , Muscle Fibers, Skeletal , Muscle Proteins , Muscular Atrophy , Neurodegenerative Diseases , Oxidative Stress , Proteasome Endopeptidase Complex , Protein Aggregates , Reactive Oxygen Species , Ubiquitin
15.
Braz. j. med. biol. res ; 50(12): e6733, 2017. graf
Article in English | LILACS | ID: biblio-888967

ABSTRACT

Myostatin is a novel negative regulator of skeletal muscle mass. Myostatin expression is also found in heart in a much less extent, but it can be upregulated in pathological conditions, such as heart failure. Myostatin may be involved in inhibiting protein synthesis and/or increasing protein degradation in skeletal and cardiac muscles. Herein, we used cell cultures and isolated muscles from rats to determine protein degradation and synthesis. Muscles incubated with myostatin exhibited an increase in proteolysis with an increase of Atrogin-1, MuRF1 and LC3 genes. Extensor digitorum longus muscles and C2C12 myotubes exhibited a reduction in protein turnover. Cardiomyocytes showed an increase in proteolysis by activating autophagy and the ubiquitin proteasome system, and a decrease in protein synthesis by decreasing P70S6K. The effect of myostatin on protein metabolism is related to fiber type composition, which may be associated to the extent of atrophy mediated effect of myostatin on muscle.


Subject(s)
Animals , Male , Muscle Fibers, Skeletal/drug effects , Muscle Fibers, Skeletal/metabolism , Myocytes, Cardiac/drug effects , Myocytes, Cardiac/metabolism , Myostatin/pharmacology , Muscle Proteins/drug effects , Muscle Proteins/metabolism , Phosphorylation/drug effects , Phosphorylation/physiology , Time Factors , Tyrosine/drug effects , Tyrosine/metabolism , Gene Expression , Cells, Cultured , Blotting, Western , Reproducibility of Results , Rats, Wistar , Real-Time Polymerase Chain Reaction , Proteolysis/drug effects
16.
Acta Physiologica Sinica ; (6): 311-315, 2017.
Article in Chinese | WPRIM | ID: wpr-348269

ABSTRACT

The aim of the present study was to measure the kinetic parameters of skeletal muscle protein synthesis in rats by deuterated water (HO). Twenty Sprague-Dawley (SD) rats were labeled byHO through intraperitoneal injection and drinking. At the each end of the 1st, 3rd, 5th, 6th and 10th week after the firstHO labeling, four rats were sacrificed by cardiac puncture for blood plasma and quadriceps femoris sampling. Skeletal muscle protein and free amino acids in plasma were purified, hydrolyzed by hydrochloric acid and derived. The deuterium enrichments ofH-labeled alanyl in skeletal muscle protein and plasma protein-boundH-labeled alanine were determined by gas chromatography-mass spectrometry (GC-MS). The fractional synthesis rate of skeletal muscle protein and synthetic dynamic equation were calculated. The fractional synthetic rate of skeletal muscle protein was 12.8%/week, and synthetic dynamic equation was f= 0.158 × (1 - e). The results suggest that the kinetic parameters of skeletal muscle protein synthesis can be measured byHO labeling, and the method can be applied in long-term labeling experiment.


Subject(s)
Alanine , Amino Acids , Blood , Animals , Deuterium , Gas Chromatography-Mass Spectrometry , Kinetics , Male , Muscle Proteins , Muscle, Skeletal , Metabolism , Protein Biosynthesis , Rats , Rats, Sprague-Dawley , Water
17.
Nutrire Rev. Soc. Bras. Aliment. Nutr ; 41: 1-17, Dec. 2016. tab, ilus
Article in English | LILACS | ID: biblio-880303

ABSTRACT

Muscle mass is the major deposit of protein molecules with dynamic turnover between net protein synthesis and degradation. In human subjects, invasive and non-invasive techniques have been applied to determine their skeletal muscle catabolism of amino acids at rest, during and after different forms of physical exercise and training. The aim of this review is to analyse the turnover flux and the relative oxidation rate of different types of muscle proteins after one bout of exercise as well as after resistance and endurance condition of training. Protein feeding in athletes appears to be a crucial nutrition necessity to promote the maintenance of muscle mass and its adaptation to the need imposed by the imposed technical requirements. In resting human individuals, there commended protein daily allowance is about 0.8 g (dry weight) kg−body weight per 24 h knowing that humans are unable to accumulate protein stores in muscle tissues. Nevertheless, practical feeding recommendations related to regular exercise practice are proposed to athletes by different bodies in order to foster their skills and performance. This review will examine the results obtained under endurance and resistance type of exercise while consuming single or repeated doses of various ingestions of protein products (full meat, essential amino acids, specific amino acids and derivatives, vegetarian food). From the scientific literature, it appears that healthy athletes(and heavy workers) should have a common diet of 1.25 g kg−24 h to compensate the exercise training muscle protein degradation and their resyn thesis within the following hours. A nitrogen-balance assay would berecommended to avoid any excessive intake of protein. Eventually, a daily equilibrated food intake would beof primer importance versus inadequate absorption of some specific by-products.


Subject(s)
Humans , Male , Female , Child , Adolescent , Adult , Amino Acids/biosynthesis , Amino Acids/metabolism , Exercise , Muscle Proteins
18.
Rev. bras. ginecol. obstet ; 38(2): 56-64, Feb. 2016. tab, graf
Article in English | LILACS | ID: lil-775636

ABSTRACT

Objective We studied the effects of loss of ovarian function (ovariectomy) onmuscle mass of gastrocnemius and themRNA levels of IGF-1, atrogin-1, MuRF-1, andmyostatin in an experimental model of rheumatoid arthritis in rats. Methods We randomly allocated 24 female Wistar rats (9 weeks, 195.3±17.4 grams) into four groups: control (CT-Sham; n = 6); rheumatoid arthritis (RA; n = 6); ovariectomy without rheumatoid arthritis (OV; n = 6); ovariectomy with rheumatoid arthritis (RAOV; n = 6). We performed the ovariectomy (OV and RAOV) or Sham (CTSham or RA) procedures at the same time, fifteen days before the rheumatoid arthritis induction. The RA and RAOV groups were immunized and then were injected with Met- BSA in the tibiotarsal joint. After 15 days of intra-articular injections the animals were euthanized. We evaluated the external manifestations of rheumatoid arthritis (perimeter joint) as well as animal weight, and food intake throughout the study. We also analyzed the cross-sectional areas (CSA) of gastrocnemius muscle fibers in 200 fibers (H&E method). In the gastrocnemius muscle, we analyzed mRNA expression by quantitative real time PCR followed by the Livak method (ΔΔCT). Results The rheumatoid arthritis induced reduction in CSA of gastrocnemius muscle fibers. The RAOV group showed a lower CSA of gastrocnemius muscle fibers compared to RA and CT-Sham groups. Skeletal muscle IGF-1 mRNA increased in arthritics and ovariectomized rats. The increased IGF-1 mRNA was higher in OV groups than in the RA and RAOV groups. Antrogin-1 mRNA also increased in the gastrocnemius muscle of arthritic and ovariectomized rats. However, the increased atrogin-1 mRNA was higher in RAOV groups than in the RA and OV groups. Gastrocnemius muscle MuRF-1 mRNA increased in the OVand RAOVgroups, but not in the RA and Shamgroups. However, the RAOV group showed higher MuRF-1 mRNA than the OV group. The myostatin gene expression was similar in all groups. Conclusion Loss of ovarian function results in increased loss of skeletal musclerelated ubiquitin ligases atrogin-1 and MuRF-1 in arthritic rats.


Objetivo Foram estudados os efeitos da perda da função ovariana (ovariectomia) sobre músculo esquelético e os níveis de RNAm de IGF-1, atrogina-1, MuRF-1, e de miostatina em modelo experimental de artrite reumatóide em ratos. Métodos 24 ratos Wistar (9 semanas, 195,3±17,4 gramas) foram distribuídos aleatoriamente em quatro grupos: controle (CT-Sham, n = 6); artrite reumatóide (RA, n = 6); ovariectomia sem artrite reumatóide (OV; n = 6); ovariectomia com artrite reumatóide (RAOV; n = 6). Os procedimentos da ovariectomia (OV e RAOV) ou simulação da ovariectomia (CT-Shamou RA) foramrealizados aomesmo tempo, quinze dias antes da indução da artrite reumatóide. Os grupos RA e RAOV foramimunizados e, em seguida, foram injetados com Met-BSA na articulação tibiotársica. Após 15 dias das injeções intra-articulares, os animais foram eutanasiados. Foram avaliadas as manifestações externas da artrite reumatóide (perimetria articular), bem como o peso dos animais e a ingestão de alimentos ao longo do estudo. Além disso, as áreas de secção transversa (CSA) do músculo gastrocnêmio foram analisadas em 200 fibras (método H & E). No músculo gastrocnêmio, a expressão de RNAm foi analisada por PCR quantitativo em tempo real, seguido pelo método Livak (ΔΔCT). Resultados A artrite reumatoide reduziu a CSA das fibras do músculo gastrocnêmio. O grupo RAOV mostrou uma CSA menor nas fibras do músculo gastrocnêmio em comparação com os grupos RA e CT-Sham. O RNAm do IGF-1 do músculo esquelético aumentou nos ratos artríticos e ovariectomizados. O RNAm do IGF-1 foi maior nos grupos OV do que nos grupos RA e RAOV. A expressão de antrogina-1 também aumentou no músculo gastrocnêmio dos ratos artríticos e ovariectomizados. No entanto, o aumento do RNAm da atrogina-1 foi maior no grupo RAOV do que nos grupos RA e OV. O RNAm da MuRF-1 aumentou nos grupos OV e RAOV, mas não nos grupos RA e CT-Sham. Porém, o grupo RAOV apresentou maior expressão gênica de MuRF-1 do que o grupo OV. A expressão do gene da miostatina foi semelhante em todos os grupos. Conclusão A perda de função ovariana resulta em perda de músculo esquelético associado às ubiquitina-ligases atrogina-1 e MuRF-1 em ratos artríticos.


Subject(s)
Animals , Female , Rats , Arthritis, Rheumatoid/physiopathology , Muscle, Skeletal/physiopathology , Disease Models, Animal , Insulin-Like Growth Factor I/metabolism , Muscle Proteins/metabolism , Myostatin/metabolism , Rats, Wistar , SKP Cullin F-Box Protein Ligases/metabolism , Tripartite Motif Proteins/metabolism , Ubiquitin-Protein Ligases/metabolism
19.
Rev. bras. cineantropom. desempenho hum ; 18(1): 1-10, Jan.-Feb. 2016. tab
Article in English | LILACS | ID: lil-778484

ABSTRACT

Abstract Although it is a widely used resource for the treatment of musculoskeletal injuries, immobilization causes deleterious effects in muscle tissue after a short period of time. This study aimed to evaluate the gastrocnemius and tibialis anterior muscles of obese and protein malnourished animals under joint immobilization condition. Overall, 28 adult male mice were used (C57 / BL6), being divided into four groups (N = 7): Control Group (CG), Immobilized Control Group (ICG), Immobilized Obese Group (IOG) and Immobilized Malnourished Group (IMG). The immobilization protocol was performed by the use of adhesive tape and plaster. The conditions and obesity and protein malnutrition have been developed through the ingestion of diets specific for each group of animals. The histomorphometric analysis of muscles evaluated area and the diameter of muscle fibers. All immobilized groups showed reduction in the area and diameter of muscle fibers when compared to GC. Comparisons among immobilized groups showed that the area and diameter of muscle fibers of IOG and IMG were lower than ICG. The immobilization protocol caused reduction in muscle trophism in animals, and obese and malnourished animals suffered high losses under condition of muscle atrophy.


Resumo Embora seja um recurso muito utilizado para tratamento de lesões musculoesqueléticas, a imobilização causa efeitos deletérios no tecido muscular após curto período de tempo. O presente estudo teve como objetivo avaliar os músculos gastrocnêmio e tibial anterior de animais obesos e desnutridos proteicamente sob a condição de imobilização articular. Foram utilizados 28 camundongos (C57/BL6) machos adultos, distribuídos em quatro grupos (N=7): Grupo controle (GC), Grupo Controle Imobilizado (GCI), Grupo Obeso imobilizado (GOI) e Grupo Desnutrido Imobilizado (GDI). O protocolo de imobilização foi realizado por meio da utilização de tiras de esparadrapo e faixa gessada. As condições de obesidade e desnutrição proteica foram desenvolvidas por meio da ingestão de dietas específicas para cada grupo de animais. A análise histomorfométrica dos músculos avaliou a área e o diâmetro das fibras musculares. Todos os grupos imobilizados apresentaram redução na área e no diâmetro das fibras musculares quando comparados ao GC. As comparações entre os grupos imobilizados mostraram que os valores do diâmetro e área de fibras dos grupos GOI e GDI foram menores do que o GCI. O protocolo de imobilização provocou redução do trofismo muscular nos animais estudados e os animais obesos e desnutridos sofreram prejuízo elevado na condição de atrofia muscular.


Subject(s)
Animals , Rats , Muscle, Skeletal/physiopathology , Muscle Proteins/deficiency , Obesity
20.
Braz. j. med. biol. res ; 49(5): e5129, 2016. tab, graf
Article in English | LILACS | ID: biblio-951677

ABSTRACT

This study aimed to evaluate the effects of exercise training on triglyceride deposition and the expression of musclin and glucose transporter 4 (GLUT4) in a rat model of insulin resistance. Thirty male Sprague-Dawley rats (8 weeks old, weight 160±10 g) were fed a high-fat diet (40% calories from fat) and randomly divided into high-fat control group and swimming intervention group. Rats fed with standard food served as normal control. We found that 8-week swimming intervention significantly decreased body weight (from 516.23±46.27 to 455.43±32.55 g) and visceral fat content (from 39.36±2.50 to 33.02±2.24 g) but increased insulin sensitivity index of the rats fed with a high-fat diet. Moreover, swimming intervention improved serum levels of TG (from 1.40±0.83 to 0.58±0.26 mmol/L) and free fatty acids (from 837.80±164.25 to 556.38±144.77 μEq/L) as well as muscle triglycerides deposition (from 0.55±0.06 to 0.45±0.02 mmol/g) in rats fed a high-fat diet. Compared with rats fed a standard food, musclin expression was significantly elevated, while GLUT4 expression was decreased in the muscles of rats fed a high-fat diet. In sharp contrast, swimming intervention significantly reduced the expression of musclin and increased the expression of GLUT4 in the muscles of rats fed a high-fat diet. In conclusion, increased musclin expression may be associated with insulin resistance in skeletal muscle, and exercise training improves lipid metabolism and insulin sensitivity probably by upregulating GLUT4 and downregulating musclin.


Subject(s)
Animals , Male , Rats , Insulin Resistance/genetics , Dietary Fats/administration & dosage , Glucose Transporter Type 4/metabolism , Lipid Metabolism/genetics , Muscle Proteins/metabolism , Physical Conditioning, Animal , Time Factors , Transcription Factors , Insulin Resistance/physiology , Dietary Fats/metabolism , Random Allocation , Gene Expression Regulation , Rats, Sprague-Dawley , Glucose Transporter Type 4/genetics , Real-Time Polymerase Chain Reaction , Muscle Proteins/genetics
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