scholarly journals Soluble Whey Protein Hydrolysate Ameliorates Muscle Atrophy Induced by Immobilization via Regulating the PI3K/Akt Pathway in C57BL/6 Mice

Nutrients ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3362
Author(s):  
Ji Eun Shin ◽  
Seok Jun Park ◽  
Seung Il Ahn ◽  
Se-Young Choung

Sarcopenia, a loss of skeletal muscle mass and function, is prevalent in older people and associated with functional decline and mortality. Protein supplementation is necessary to maintain skeletal muscle mass and whey protein hydrolysates have the best nutrient quality among food proteins. In the first study, C57BL/6 mice were subjected to immobilization for 1 week to induce muscle atrophy. Then, mice were administered with four different whey protein hydrolysates for 2 weeks with continuous immobilization. Among them, soluble whey protein hydrolysate (WP-S) had the greatest increase in grip strength, muscle weight, and cross-sectional area of muscle fiber than other whey protein hydrolysates. To investigate the molecular mechanism, we conducted another experiment with the same experimental design. WP-S significantly promoted the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway and inhibited the PI3K/Akt/forkhead box O (FoxO) pathway. In addition, it increased myosin heavy chain (MyHC) expression in both the soleus and quadriceps and changed MyHC isoform expressions. In conclusion, WP-S attenuated muscle atrophy induced by immobilization by enhancing the net protein content regulating muscle protein synthesis and degradation. Thus, it is a necessary and probable candidate for developing functional food to prevent sarcopenia.

Author(s):  
Paulo Sugihara Junior ◽  
Alex S. Ribeiro ◽  
Hellen C.G. Nabuco ◽  
Rodrigo R. Fernandes ◽  
Crisieli M. Tomeleri ◽  
...  

The purpose of this study was to investigate the effect of whey protein (WP) supplementation on muscular strength, hypertrophy, and muscular quality in older women preconditioned to resistance training (RT). In a randomized, double-blind, and placebo (PLA)-controlled design, 31 older women (67.4 ± 4.0 years, 62.0 ± 6.9 kg, 155.9 ± 5.7 cm, and 25.5 ± 2.4 kg/m2) received either 35 g of WP (n = 15) or 35 g of PLA (n = 16) over a 12-week study period while performing an RT program three times a week. Dietary intake, one-repetition maximum test, and skeletal muscle mass by dual-energy X-ray absorptiometry were assessed before and after the intervention period. Both groups showed significant (p < .05) improvements in skeletal muscle mass and total strength, and the WP group realized greater increases (p < .05) in these measures compared with PLA (skeletal muscle mass: WP = +4.8% vs. PLA = +2.3%; strength: WP = +8.7% vs. PLA = +4.9%). Muscular quality increased (p < .05) in both groups (WP = +2.9% vs. PLA = +1.5%) without statistical differences (p > .05) noted between conditions. We conclude that WP supplementation in combination with RT induces higher increases in both strength and hypertrophy in older women preconditioned to RT.


2014 ◽  
Vol 116 (11) ◽  
pp. 1491-1502 ◽  
Author(s):  
Renae J. Stefanetti ◽  
Séverine Lamon ◽  
Stine K. Rahbek ◽  
Jean Farup ◽  
Evelyn Zacharewicz ◽  
...  

Knowledge from human exercise studies on regulators of muscle atrophy is lacking, but it is important to understand the underlying mechanisms influencing skeletal muscle protein turnover and net protein gain. This study examined the regulation of muscle atrophy–related factors, including atrogin-1 and MuRF1, their upstream transcription factors FOXO1 and FOXO3A and the atrogin-1 substrate eIF3-f, in response to unilateral isolated eccentric (ECC) vs. concentric (CONC) exercise and training. Exercise was performed with whey protein hydrolysate (WPH) or isocaloric carbohydrate (CHO) supplementation. Twenty-four subjects were divided into WPH and CHO groups and completed both single-bout exercise and 12 wk of training. Single-bout ECC exercise decreased atrogin-1 and FOXO3A mRNA compared with basal and CONC exercise, while MuRF1 mRNA was upregulated compared with basal. ECC exercise downregulated FOXO1 and phospho-FOXO1 protein compared with basal, and phospho-FOXO3A was downregulated compared with CONC. CONC single-bout exercise mediated a greater increase in MuRF1 mRNA and increased FOXO1 mRNA compared with basal and ECC. CONC exercise downregulated FOXO1, FOXO3A, and eIF3-f protein compared with basal. Following training, an increase in basal phospho-FOXO1 was observed. While WPH supplementation with ECC and CONC training further increased muscle hypertrophy, it did not have an additional effect on mRNA or protein levels of the targets measured. In conclusion, atrogin-1, MuRF1, FOXO1/3A, and eIF3-f mRNA, and protein levels, are differentially regulated by exercise contraction mode but not WPH supplementation combined with hypertrophy-inducing training. This highlights the complexity in understanding the differing roles these factors play in healthy muscle adaptation to exercise.


Author(s):  
Carolina Soares Moura ◽  
Pablo Christiano Barboza Lollo ◽  
Priscila Neder Morato ◽  
Luciana Hisayama Nisishima ◽  
Everardo Magalhães Carneiro ◽  
...  

2020 ◽  
Vol 21 (5) ◽  
pp. 1628 ◽  
Author(s):  
Keisuke Hitachi ◽  
Masashi Nakatani ◽  
Shiori Funasaki ◽  
Ikumi Hijikata ◽  
Mizuki Maekawa ◽  
...  

Skeletal muscle is a highly plastic organ that is necessary for homeostasis and health of the human body. The size of skeletal muscle changes in response to intrinsic and extrinsic stimuli. Although protein-coding RNAs including myostatin, NF-κβ, and insulin-like growth factor-1 (IGF-1), have pivotal roles in determining the skeletal muscle mass, the role of long non-coding RNAs (lncRNAs) in the regulation of skeletal muscle mass remains to be elucidated. Here, we performed expression profiling of nine skeletal muscle differentiation-related lncRNAs (DRR, DUM1, linc-MD1, linc-YY1, LncMyod, Neat1, Myoparr, Malat1, and SRA) and three genomic imprinting-related lncRNAs (Gtl2, H19, and IG-DMR) in mouse skeletal muscle. The expression levels of these lncRNAs were examined by quantitative RT-PCR in six skeletal muscle atrophy models (denervation, casting, tail suspension, dexamethasone-administration, cancer cachexia, and fasting) and two skeletal muscle hypertrophy models (mechanical overload and deficiency of the myostatin gene). Cluster analyses of these lncRNA expression levels were successfully used to categorize the muscle atrophy models into two sub-groups. In addition, the expression of Gtl2, IG-DMR, and DUM1 was altered along with changes in the skeletal muscle size. The overview of the expression levels of lncRNAs in multiple muscle atrophy and hypertrophy models provides a novel insight into the role of lncRNAs in determining the skeletal muscle mass.


PLoS ONE ◽  
2014 ◽  
Vol 9 (1) ◽  
pp. e83437 ◽  
Author(s):  
Carolina Soares Moura ◽  
Pablo Christiano Barboza Lollo ◽  
Priscila Neder Morato ◽  
Luciana Hisayama Nisishima ◽  
Everardo Magalhães Carneiro ◽  
...  

2020 ◽  
Vol 129 (2) ◽  
pp. 272-282 ◽  
Author(s):  
Sue C. Bodine

Skeletal muscle atrophy continues to be a serious consequence of many diseases and conditions for which there is no treatment. Our understanding of the mechanisms regulating skeletal muscle mass has improved considerably over the past two decades. For many years it was known that skeletal muscle atrophy resulted from an imbalance between protein synthesis and protein breakdown, with the net balance shifting toward protein breakdown. However, the molecular and cellular mechanisms underlying the increased breakdown of myofibrils was unknown. Over the past two decades, numerous reports have identified novel genes and signaling pathways that are upregulated and activated in response to stimuli such as disuse, inflammation, metabolic stress, starvation and others that induce muscle atrophy. This review summarizes the discovery efforts performed in the identification of several pathways involved in the regulation of skeletal muscle mass: the mammalian target of rapamycin (mTORC1) and the ubiquitin proteasome pathway and the E3 ligases, MuRF1 and MAFbx. While muscle atrophy is a common outcome of many diseases, it is doubtful that a single gene or pathway initiates or mediates the breakdown of myofibrils. Interestingly, however, is the observation that upregulation of the E3 ligases, MuRF1 and MAFbx, is a common feature of many divergent atrophy conditions. The challenge for the field of muscle biology is to understand how all of the various molecules, transcription factors, and signaling pathways interact to produce muscle atrophy and to identify the critical factors for intervention.


2018 ◽  
Vol 108 (5) ◽  
pp. 1026-1033 ◽  
Author(s):  
Yongsoon Park ◽  
Jeong-Eun Choi ◽  
Hwan-Sik Hwang

ABSTRACTBackgroundAge-related loss of muscle mass and function is a major component of frailty. Nutrition supplementation with exercise is an effective strategy to decrease frailty by preventing sarcopenia, but the effect of protein alone is controversial.ObjectiveThe present study was performed to investigate a dose-dependent effect of protein supplementation on muscle mass and frailty in prefrail or frail malnourished elderly people.DesignA 12-wk double-blind randomized controlled trial was conducted in elderly subjects aged 70–85 y with ≥1 of the Cardiovascular Health Study frailty criteria and a Mini Nutritional Assessment score ≤23.5 (n = 120). Participants were randomly assigned to 1 of 3 groups: 0.8, 1.2, or 1.5 g protein · kg–1 · d–1, with concealed allocation and intention-to-treat analysis. Primary outcomes were appendicular skeletal muscle mass (ASM) and skeletal muscle mass index (SMI) measured by dual-energy X-ray absorptiometry.ResultsAfter the 12-wk intervention, the 1.5-g protein · kg–1 · d–1 group had higher ASM (mean ± SD: 0.52 ± 0.64 compared with 0.08 ± 0.68 kg, P = 0.036) and SMI (ASM/weight: 0.87% ± 0.69% compared with 0.15% ± 0.89%, P = 0.039; ASM/BMI: 0.02 ± 0.03 compared with 0.00 ± 0.04, P = 0.033; ASM:fat ratio: 0.04 ± 0.11 compared with −0.02 ± 0.10, P = 0.025) than the 0.8-g protein · kg–1 · d–1 group. In addition, gait speed was improved in the 1.5-g protein · kg–1 · d–1 group compared with the 0.8-g protein · kg–1 · d–1 group (0.09 ± 0.07 compared with 0.04 ± 0.07 m/s, P = 0.039). There were no significant differences between the 1.2- and 0.8-g protein · kg–1 · d–1 groups in muscle mass and physical performance. No harmful adverse effects were observed.ConclusionsThe present study indicates that protein intake of 1.5 g · kg–1 · d–1 has the most beneficial effects in regard to preventing sarcopenia and frailty compared with protein intakes of 0.8 and 1.2 g · kg–1 · d–1 in prefrail or frail elderly subjects at risk of malnutrition. This trial was registered at cris.nih.go.kr as KCT0001923.


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