Signaling Pathways that Mediate Skeletal Muscle Hypertrophy: Effects of Exercise Training

Fernandes, Tiago; Soci, Úrsula Paula Renó; Melo, Stéphano Freitas Soares; Alves, Cléber R.; Oliveira, Edilamar Menezes de

doi:10.5772/51087

Cited by 19 publications

(27 citation statements)

References 140 publications

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“…Similarly, insulin’s ability to activate the same IGF/PI3K/Akt signaling axis as IGF-1, and thus effect Foxo1 activity, is well established [23]. This similar convergence upon the same PI3K/Akt signaling pathway helps determine the balance of protein synthesis, via mTor and GSK3 pathways, and protein degradation via Foxo [10]. The specificity observed between responses to IGF-1 and insulin is thought to be a result of differences in receptor expression and tissue specific downstream targets [23].…”

Section: 0 Discussionmentioning

confidence: 99%

Green tea component EGCG, insulin and IGF-1 promote nuclear efflux of atrophy-associated transcription factor Foxo1 in skeletal muscle fibers

Wimmer

Russell

Schneider

2015

The Journal of Nutritional Biochemistry

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Prevention and slowing of skeletal muscle atrophy with nutritional approaches offers the potential to provide far reaching improvements in the quality of life for our increasingly aging population. Here we show polyphenol flavonoid Epigallocatechin 3-gallate (EGCG), found in the popular beverage green tea (Camellia sinensis), demonstrates similar effects as the endogenous hormones IGF-1 and insulin in the ability to suppress action of the atrophy-promoting transcription factor Foxo1 through a net translocation of Foxo1 out of the nucleus as monitored by nucleo-cytoplasmic movement of Foxo1-GFP in live skeletal muscle fibers. Foxo1-GFP nuclear efflux is rapid in IGF-1 or insulin, but delayed by an additional 30 min for EGCG. Once activated, kinetic analysis with a simple mathematical model shows EGCG, IGF-1 and insulin all produce similar apparent rate constants for Foxo1-GFP unidirectional nuclear influx and efflux. Interestingly, EGCG appears to have its effect at least partially via parallel signaling pathways that are independent of IGF-1’s (and insulin’s) downstream PI3K/Akt/Foxo1 signaling axis. Using the live fiber model system, we also determine the dose-response curve for both IGF-1 and insulin on Foxo1 nucleo-cytoplasmic distribution. The continued understanding of the activation mechanisms of EGCG could allow for nutritional promotion of Green Tea’s anti-atrophy skeletal muscle benefits and have implications in development of a clinically significant parallel pathway for new drugs to target muscle wasting and the reduced insulin receptor sensitivity which causes Type II Diabetes Mellitus.

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Section: 0 Discussionmentioning

confidence: 99%

Green tea component EGCG, insulin and IGF-1 promote nuclear efflux of atrophy-associated transcription factor Foxo1 in skeletal muscle fibers

Wimmer

Russell

Schneider

2015

The Journal of Nutritional Biochemistry

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“…Entretanto, apenas o treinamento combinado foi eficaz no aumento do hormônio de crescimento (GH). Sabe-se que o IGF-1 e o GH desempenham importante papel na hipertrofia da musculatura esquelética 58 , e como já descrito no tópico do treinamento resistido, a massa muscular pode melhorar a capacidade funcional, qualidade de vida e reduzir o risco de quedas 14,36 , além de ser um importante preditor de longevidade em populações mais velhas 59,60 . Em relação aos fatores risco para síndrome metabólica, o treinamento combinado foi o mais eficaz em diminuir a circunferência de cintura e glicose de jejum, e apesar de não estatisticamente significativo, também diminuiu as concentrações de TG e aumentou as concentrações de HDL-c.…”

Section: Treinamento Combinadounclassified

Exercício Físico Como Tratamento Não Farmacológico Para a Melhora Da Saúde Pós-Menopausa

Diniz

Rossi

Buonani

et al. 2017

Rev Bras Med Esporte

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RESUMOO período da pós-menopausa é caracterizado por 12 meses consecutivos de amenorreia. Além de afetar o sistema reprodutivo e a produção de hormônios sexuais, principalmente o estrógeno, essas mulheres apresentam aumento da gordura corporal total, principalmente na região central, o que está relacionado com o desenvolvimento de diversas doenças crônicas, como dislipidemia, aterosclerose e resistência à insulina. Dessa forma, diferentes programas de exercício físico, aeróbico, resistido ou combinado (aeróbico e resistido em uma mesma sessão) podem ser uma forma interessante de tratamento não farmacológico para a prevenção e melhora dos desfechos. Entretanto, as adaptações promovidas pelos diferentes programas de exercício sobre a composição corporal, perfil lipídico e glicêmico não estão claras na literatura e precisam ser elucidadas. Assim sendo, esta revisão tem como objetivo discutir as diferentes adaptações do treinamento aeróbico, resistido e combinado na composição corporal, perfil lipídico e glicêmico de mulheres na pós-menopausa.Descritores: treinamento de resistência; exercício; pós-menopausa; composição corporal; lipoproteínas; metabolismo. ABSTRACT

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“…All of these kinases are activated by increased shear forces at the cell membrane of endothelial cells due to increased blood flow during exercise, with ERK1/2 exhibiting only a transient response and returning to the baseline within 30-60 min of increased 730 blood flow (Zhang et al, 2009). Furthermore, exercise induced increase of AMP/ATP ratio also activates AMPK (Zhang et al, 2009), and strength exercise induced insulin-like growth factor I (IGF-I) increment (Vissing et al, 2013) activates the AKT pathway in skeletal muscle (Fernandes et al, 2012) and endothelial cells (Kim et al, 1999;Sowers, 2004;Standley et al, 1993;Standley et al, 1995). The resulting active NO signaling is required for eNOS to be co-localized together with estrogen receptor alpha (ERα; bound ligand re-735 quired) in the nucleus, where the eNOS/ERα complex binds to estrogen receptor elements (ERE) in the hTERT promoter.…”

Section: Potential Pathways For Exercise Dependent Telomerase Activitmentioning

confidence: 99%

The influence of physical exercise and sports on telomere length - A model for telomere length and telomerase activity regulation based on a comparative assessment of literature

Fröhlich

2016

Preprint

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Based upon a comprehensive analysis of current literature and by combining a molecular biology and a sports science perspective, this review examines (1) if a correlation between physical activity load and telomere length (TL) exists, and (2) comprehensively analyses and integrates molecular pathways regulating exercise dependent TL dynamics. The focus is on TL in leukocytes and muscle tissue in middle to advanced aged subjects. Regarding item (1), a strong tendency for an increase in mean leukocyte TL was found for exercise energy expenditures up to about 2∙103 kcal/week, while for higher activity levels no conclusive statement can be made. Conversely, research on skeletal muscle TL so far is quite limited but suggests that physical exercise with prolonged eccentric muscle contractions rather acts to shorten telomeres, while sports with little eccentric contractions might rather act to lengthen telomeres. As to item (2), a model for hypothetical pathways for exercise dependent telomerase activity regulation is proposed by consolidating findings of different studies in different cells. Consistent with this pathway model, various studies report increased telomerase transcription or activation by exercise. Moreover, a qualitative overall model for endurance exercise related TL dynamics is presented. It considers telomeres as dynamic structures in equilibrium between telomere shortening (e.g., cellular turnover, oxidative stress, inflammation) and telomere lengthening (e.g., telomerase activity, telomerase recruitment) effects. A negative feedback-loop mediated by enhanced telomerase recruitment to short telomeres is assumed to counteract too excessive TL alterations. Finally, a proposal is put forth for future research on exercise dependent telomere dynamics by adopting a systems biology approach to develop mathematical models that properly integrate the complexity of the interacting variables.

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Signaling Pathways that Mediate Skeletal Muscle Hypertrophy: Effects of Exercise Training

Cited by 19 publications

References 140 publications

Green tea component EGCG, insulin and IGF-1 promote nuclear efflux of atrophy-associated transcription factor Foxo1 in skeletal muscle fibers

Green tea component EGCG, insulin and IGF-1 promote nuclear efflux of atrophy-associated transcription factor Foxo1 in skeletal muscle fibers

Exercício Físico Como Tratamento Não Farmacológico Para a Melhora Da Saúde Pós-Menopausa

The influence of physical exercise and sports on telomere length - A model for telomere length and telomerase activity regulation based on a comparative assessment of literature

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