Navegando por Palavras-chave "Protein synthesis"
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- ItemSomente MetadadadosChronic resistance training decreases MuRF-1 and Atrogin-1 gene expression but does not modify Akt, GSK-3 beta and p70S6K levels in rats(Springer, 2009-06-01) Zanchi, Nelo Eidy; Siqueira Filho, Mario Alves de; Lira, Fabio Santos [UNIFESP]; Rosa, Jose Cesar [UNIFESP]; Yamashita, Alex Shimura; Oliveira Carvalho, Carla Roberta de; Seelaender, Marilia; Lancha, Antonio Herbert; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)Long-term adaptation to resistance training is probably due to the cumulative molecular effects of each exercise session. Therefore, we studied in female Wistar rats the molecular effects of a chronic resistance training regimen (3 months) leading to skeletal muscle hypertrophy in the plantaris muscle. Our results demonstrated that muscle proteolytic genes MuRF-1 and Atrogin-1 were significantly decreased in the exercised group measured 24 h after the last resistance exercise session (41.64 and 61.19%, respectively; P < 0.05). Nonetheless, when measured at the same time point, 4EBP-1, GSK-3 beta and eIF2B epsilon mRNA levels and Akt, GSK-3 beta and p70S6K protein levels (regulators of translation initiation) were not modified. Such data suggests that if gene transcription constitutes a control point in the protein synthesis pathway this regulation probably occurs in early adaptation periods or during extreme situations leading to skeletal muscle remodeling. However, proteolytic gene expression is modified even after a prolonged resistance training regimen leading to moderate skeletal muscle hypertrophy.
- ItemAcesso aberto (Open Access)Efeitos da Suplementação com Whey Protein e da Prática de Exercícios Físicos no Músculo Esquelético de Idosos: uma Revisão da Literatura(Universidade Federal de São Paulo, 2021-02-26) Rebelo, Rachel Soares Macedo [UNIFESP]; Lambertucci, Rafael Herling [UNIFESP]; http://lattes.cnpq.br/5826005580515987; http://lattes.cnpq.br/7726580702379579; Universidade Federal de São Paulo (UNIFESP)O envelhecimento é capaz de promover diversas mudanças dentro e fora do organismo, especialmente alterações na composição corporal, como a perda de massa magra e a redução da força, processos conhecidos como sarcopenia e dinapenia, respectivamente. A manutenção da saúde nessa etapa da vida pode ser realizada pela adoção de hábitos saudáveis, principalmente com a manipulação da dieta e protocolos de treino individualizados que priorizem o treinamento resistido. O objetivo deste estudo foi apresentar os principais benefícios da suplementação com whey protein e da prática de exercícios físicos no tecido muscular esquelético de idosos, por meio de uma revisão narrativa de literatura, a partir da Biblioteca SciELO e PubMed no período de 2000 a 2020. Os resultados demonstraram que idosos se beneficiam do treinamento de força e da suplementação com whey protein, pois ambos os estímulos são capazes de interagir com a mesma via de sinalização para aumento de força e hipertrofia muscular, por meio do complexo mTOR.
- ItemSomente MetadadadosGCN2 activation and eIF2 alpha phosphorylation in the maturation of mouse oocytes(Elsevier B.V., 2009-01-02) Alves, Viviane S. [UNIFESP]; Motta, Fabiana L. [UNIFESP]; Roffe, Martin [UNIFESP]; Delamano, Arthur [UNIFESP]; Pesquero, Joao B. [UNIFESP]; Castilho, Beatriz A. [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)GCN2 is one of the four mammalian kinases that phosphorylate the alpha subunit of the translation initiation factor 2 (eIF2 alpha) in a variety of stress situations, resulting in protein synthesis inhibition. GCN2 is involved in regulating metabolism, feeding behavior and memory in rodents. We show here that, relative to other cells, the beta isoform of the GCN2 transcript and the GCN2 protein are highly abundant in unfertilized mouse eggs. in addition, GCN2 in these cells is active, resulting in elevated levels of phosphorylated eIF2 alpha. After fertilization, eIF2 alpha phosphorylation decreases drastically. These results suggest that GCN2 mediated translational control may contribute to regulatory mechanisms operating during oocyte maturation. (C) 2008 Elsevier Inc. All rights reserved.
- ItemSomente MetadadadosLeucine supplementation is anti-atrophic during paradoxical sleep deprivation in rats(Springer Wien, 2016) Souza, Helton de Sá [UNIFESP]; Antunes, Hanna Karen Moreira [UNIFESP]; Dattilo, Murilo [UNIFESP]; Lee, Kil Sun [UNIFESP]; Mônico-Neto, Marcos [UNIFESP]; Giampá, Sara Quaglia de Campos [UNIFESP]; Phillips, Stuart M.; Tufik, Sergio [UNIFESP]; Mello, Marco Tulio de [UNIFESP]The purpose of this study was to identify sleep deprivation-induced atrophy and the muscle-specific fiber types affected and to determine the effects of leucine supplementation on atrophy and pertinent portions of the pathways of muscle protein synthesis and degradation in rats. A total of 46 Wistar rats were distributed in four groups: control (CTL), leucine supplementation (LEU), sleep deprivation (SD), and leucine supplementation + sleep deprivation (LEU + SD). Leucine supplementation was by gavage (1.35 g/kg/daily), and the animals were subjected to SD for 96 h. Testosterone and corticosterone concentrations, along with proteins involved in protein synthesis and degradation and proteasome activity levels, were measured in the gastrocnemius (GA) muscle. Myosin ATPase staining was used to evaluate the different muscle fibers. After sleep deprivation, GA muscle and body masses decreased in the SD group compared to the CTL, LEU, and LEU + SD groups. There was no difference between groups in type I fiber cross-sectional area (CSA). The CSAs for type IIa fibers were lower in the SD and LEU + SD groups vs. the CTL and LEU groups, while the IIb fiber CSA was lower in the SD group vs. the CSAs in all other groups. The phospho (p)-Akt levels were lower in the SD and LEU + SD groups vs. the CTL and LEU groups. The p-mTORC1 levels were higher in the LEU, SD, and LEU + SD groups vs. the CTL group. The p-p70S6k levels were higher in the LEU and LEU + SD groups; the 4E-BP1 levels were higher in the SD and LEU + SD groups compared to those in the CTL and LEU groups, and the p-4E-BP1 levels were higher in the LEU and SD groups compared to those in the CTL group and even higher in the LEU + SD group compared to those in the LEU and SD groups. Ubiquitinated proteins, LC3, and p62/SQSTM, and proteasome activity levels were higher in the SD and LEU + SD groups vs. the LEU and CTL groups. Sleep deprivation led to the atrophy of IIa and IIb muscle fibers; however, leucine supplementation prevented muscle loss and type IIb fiber atrophy.
- ItemSomente MetadadadosNeonatal mitochondrial encephaloneuromyopathy due to a defect of mitochondrial protein synthesis(Elsevier B.V., 2008-12-15) Ferreiro-Barros, Claudia Cristina [UNIFESP]; Tengan, Celia Harumi [UNIFESP]; Barros, Mario Henrique de; Palenzuela, Lluis; Kanki, Chisaka; Quinzii, Catarina; Lou, Johanna; El Gharaby, Nader; Shokr, Aly; De Vivo, Darryl C.; DiMauro, Salvatore; Hirano, Michio; Columbia Univ; Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP); Bugshan Gen HospMitochondrial diseases are clinically and genetically heterogeneous disorders due to primary mutations in mitochondrial DNA (mtDNA) or nuclear DNA (nDNA). We studied a male infant with severe congenital encephalopathy, peripheral neuropathy, and myopathy. the patient's lactic acidosis and biochemical defects of respiratory chain complexes I, III, and IV in muscle indicated that he had a mitochondrial disorder while parental consanguinity suggested autosomal recessive inheritance. Cultured fibroblasts from the patient showed a generalized defect of mitochondrial protein synthesis. Fusion of cells from the patient with 143B206 rho(0) cells devoid of mtDNA restored cytochrome c oxidase activity confirming the nDNA origin of the disease. Our studies indicate that the patient has a novel autosomal recessive defect of mitochondrial protein synthesis. (C) 2008 Elsevier B.V. All rights reserved.