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Botella J, Shaw CS, Bishop DJ. Autophagy and Exercise: Current Insights and Future Research Directions. Int J Sports Med 2024; 45:171-182. [PMID: 37582398 DOI: 10.1055/a-2153-9258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/17/2023]
Abstract
Autophagy is a cellular process by which proteins and organelles are degraded inside the lysosome. Exercise is known to influence the regulation of autophagy in skeletal muscle. However, as gold standard techniques to assess autophagy flux in vivo are restricted to animal research, important gaps remain in our understanding of how exercise influences autophagy activity in humans. Using available datasets, we show how the gene expression profile of autophagy receptors and ATG8 family members differ between human and mouse skeletal muscle, providing a potential explanation for their differing exercise-induced autophagy responses. Furthermore, we provide a comprehensive view of autophagy regulation following exercise in humans by summarizing human transcriptomic and phosphoproteomic datasets that provide novel targets of potential relevance. These newly identified phosphorylation sites may provide an explanation as to why both endurance and resistance exercise lead to an exercise-induced reduction in LC3B-II, while possibly divergently regulating autophagy receptors, and, potentially, autophagy flux. We also provide recommendations to use ex vivo autophagy flux assays to better understand the influence of exercise, and other stimuli, on autophagy regulation in humans. This review provides a critical overview of the field and directs researchers towards novel research areas that will improve our understanding of autophagy regulation following exercise in humans.
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Affiliation(s)
- Javier Botella
- Metabolic Research Unit, School of Medicine and Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Waurn Ponds, Victoria, Australia
| | - Christopher S Shaw
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, 3216, VIC, Australia
| | - David J Bishop
- Institute for Health and Sport (iHeS), Victoria University, Melbourne, Australia
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Daneshyar S, Tavoosidana G, Bahmani M, Basir SS, Delfan M, Laher I, Saeidi A, Granacher U, Zouhal H. Combined effects of high fat diet and exercise on autophagy in white adipose tissue of mice. Life Sci 2023; 314:121335. [PMID: 36587790 DOI: 10.1016/j.lfs.2022.121335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 12/24/2022] [Accepted: 12/25/2022] [Indexed: 12/30/2022]
Abstract
AIM The effects of nutrition and exercise on autophagy are not well studied. This study aimed to investigate the combined effects of high-fat diets (HFD) and exercise training (ET) on autophagy in white adipose tissue of mice. MATERIALS AND METHODS Male C57BL/6 mice were assigned into four groups of 7 mice per group: (1) Control, (2) high-fat diet-induced obesity (HFD-Ob), (3) exercise training (ET), and (4) high-fat diet with exercise training (HFD-ET). The HFD-Ob group was fed a high-fat diet for 14 weeks, while the ET group continuously ran on a treadmill for five sessions per week for seven weeks, and the HFD-ET group had both HFD and exercise training. qReal-time-PCR and western blot were used to measure the mRNA and protein levels of autophagy markers in white adipose tissue. RESULTS Mice from the HFD group showed higher levels in autophagy-related gene5 (ATG5, p = 0.04), ATG7 (p = 0.002), cathepsin B (CTSB, p = 0.0004), LC3-II (p = 0.03) than control. Mice in the ET group displayed higher levels of genes for ATG7 (p = 0.0003), microtubule-associated protein1-light chain 3 (LC3, p = 0.05), lysosome-associated membrane protein 2 (LAMP2, p = 0.04) and cathepsin L (CTSL, p = 0.03) than control. Mice from the HFD-ET group had higher levels of genes for ATG7 (p = 0.05) and CTSL (p = 0.043) and lower levels of genes for CTSB (p = 0.045) compared to the HFD group and lower levels of LAMP2 (p = 0.02) compared to the ET group. CONCLUSION There were increases in autophagosome formation in the white adipose tissue from mice in the HFD and ET groups. A combination of HFD and ET enhances autophagosome formation and modulates lysosomal degradation in white adipose tissue.
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Affiliation(s)
- Saeed Daneshyar
- Department of Physical Education, Faculty of Humanities, Ayatollah Alozma Boroujerdi University, Lorestan, Iran; Department of Physical Education, Hamedan University of Technology, Hamedan, Iran.
| | - Gholamreza Tavoosidana
- Department of Molecular Medicine, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mahdi Bahmani
- Department of Biochemistry, Faculty of Medicine, Hamedan University of Medical Sciences, Hamedan, Iran
| | - Saeed Shokati Basir
- Department of Exercise Physiology, Faculty of Physical Education, University of Guilan, Guilan, Iran
| | - Maryam Delfan
- Department of Exercise Physiology, Faculty of Sport Sciences, Alzahra University, Tehran, Iran
| | - Ismail Laher
- Department of Anesthesiology, Pharmacology, and Therapeutics, Faculty of Medicine, University of British Columbia, Vancouver, Canada
| | - Ayoub Saeidi
- Department of Physical Education and Sport Sciences, Faculty of Humanities and Social Sciences, University of Kurdistan, Sanandaj, Kurdistan, Iran
| | - Urs Granacher
- Department of Sport and Sport Science, Exercise and Human Movement Science, University of Freiburg, Germany.
| | - Hassane Zouhal
- Univ Rennes, M2S (Laboratoire Mouvement, Sport, Santé) - EA 1274, F-35000 Rennes, France; Institut International des Sciences du Sport (2I2S), 35850 Irodouer, France.
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Coding and Noncoding Genes Involved in Atrophy and Compensatory Muscle Growth in Nile Tilapia. Cells 2022; 11:cells11162504. [PMID: 36010581 PMCID: PMC9406742 DOI: 10.3390/cells11162504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 08/03/2022] [Indexed: 11/16/2022] Open
Abstract
Improvements in growth-related traits reduce fish time and production costs to reach market size. Feed deprivation and refeeding cycles have been introduced to maximize aquaculture profits through compensatory growth. However, the molecular compensatory growth signature is still uncertain in Nile tilapia. In this study, fish were subjected to two weeks of fasting followed by two weeks of refeeding. The growth curve in refed tilapia was suggestive of a partial compensatory response. Transcriptome profiling of starved and refed fish was conducted to identify genes regulating muscle atrophy and compensatory growth. Pairwise comparisons revealed 5009 and 478 differentially expressed (differential) transcripts during muscle atrophy and recovery, respectively. Muscle atrophy appears to be mediated by the ubiquitin-proteasome and autophagy/lysosome systems. Autophagy-related 2A, F-box and WD repeat domain containing 7, F-box only protein 32, miR-137, and miR-153 showed exceptional high expression suggesting them as master regulators of muscle atrophy. On the other hand, the muscle compensatory growth response appears to be mediated by the continuous stimulation of muscle hypertrophy which exceeded normal levels found in control fish. For instance, genes promoting ribosome biogenesis or enhancing the efficiency of translational machinery were upregulated in compensatory muscle growth. Additionally, myogenic microRNAs (e.g., miR-1 and miR-206), and hypertrophy-associated microRNAs (e.g., miR-27a-3p, miR-29c, and miR-29c) were reciprocally expressed to favor hypertrophy during muscle recovery. Overall, the present study provided insights into the molecular mechanisms regulating muscle mass in fish. The study pinpoints extensive growth-related gene networks that could be used to inform breeding programs and also serve as valuable genomic resources for future mechanistic studies.
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Sherafati-Moghadam M, Pahlavani HA, Daryanoosh F, Salesi M. The effect of high-intensity interval training (HIIT) on protein expression in Flexor Hallucis Longus (FHL) and soleus (SOL) in rats with type 2 diabetes. J Diabetes Metab Disord 2022. [PMID: 36404870 PMCID: PMC9672293 DOI: 10.1007/s40200-022-01091-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Purpose In people with diabetes, one of the problems for patients is muscle wasting and inhibition of the protein synthesis pathway. This study aimed to evaluate the effects of HIIT on protein expression in two skeletal muscles, flexor hallucis longus (FHL) and soleus (SOL) in rats with type 2 diabetes mellitus (T2DM). Materials and methods Diabetes initially was induced by streptozotocin (STZ) and nicotinamide. Rats with type 2 diabetes were randomly and equally divided into control (n = 6) and HIIT groups (n = 6). After 8 weeks of training, the content of total and phosphorylated proteins of serine/threonine-protein kinases (AKT1), mammalian target of rapamycin (mTOR), P70 ribosomal protein S6 kinase 1 (P70S6K1), and 4E (eIF4E)-binding protein 1 (4E-BP1) in FHL and SOL muscles were measured by Western blotting. While body weight and blood glucose were also controlled. Results In the HIIT training group, compared to the control group, a significant increase in the content of AKT1 (0.003) and mTOR (0.001) proteins was observed in the FHL muscle. Also, after 8 weeks of HIIT training, protein 4E-BP1 (0.001) was increased in SOL muscle. However, there was no significant change in other proteins in FHL and SOL muscle. Conclusions In rats with type 2 diabetes appear to HIIT leading to more protein expression of fast-twitch muscles than slow-twitch muscles. thus likely HIIT exercises can be an important approach to increase protein synthesis and prevent muscle atrophy in people with type 2 diabetes.
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Wang C, Liang J, Ren Y, Huang J, Jin B, Wang G, Chen N. A Preclinical Systematic Review of the Effects of Chronic Exercise on Autophagy-Related Proteins in Aging Skeletal Muscle. Front Physiol 2022; 13:930185. [PMID: 35910582 PMCID: PMC9329943 DOI: 10.3389/fphys.2022.930185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 06/17/2022] [Indexed: 11/13/2022] Open
Abstract
Background: Exercise is one of the most effective interventions for preventing and treating skeletal muscle aging. Exercise-induced autophagy is widely acknowledged to regulate skeletal muscle mass and delay skeletal muscle aging. However, the mechanisms underlying of the effect of different exercises on autophagy in aging skeletal muscle remain unclear. Methods: A systematic review was performed following an electronic search of SCOPUS, PubMed, Web of Science, ScienceDirect, and Google Scholar and two Chinese electronic databases, CNKI and Wan Fang. All articles published in English and Chinese between January 2010 and January 2022 that quantified autophagy-related proteins in aging skeletal muscle models. Results: The primary outcome was autophagy assessment, indicated by changes in the levels of any autophagy-associated proteins. A total of fifteen studies were included in the final review. Chronic exercise modes mainly comprise aerobic exercise and resistance exercise, and the intervention types include treadmill training, voluntary wheel running, and ladder training. LC3, Atg5-Atg7/9/12, mTOR, Beclin1, Bcl-2, p62, PGC-1α, and other protein levels were quantified, and the results showed that long-term aerobic exercise and resistance exercise could increase the expression of autophagy-related proteins in aging skeletal muscle (p < 0.05). However, there was no significant difference in short term or high-intensity chronic exercise, and different types and intensities of exercise yielded different levels of significance for autophagy-related protein expression. Conclusion: Existing evidence reveals that high-intensity exercise may induce excessive autophagy, while low-intensity exercise for a short period (Intervention duration <12 weeks, frequency <3 times/week) may not reach the threshold for exercise-induced autophagy. Precise control of the exercise dose is essential in the long term to maximize the benefits of exercise. Further investigation is warranted to explore the relationship between chronic exercise and different exercise duration and types to substantiate the delaying of skeletal muscle aging by exercise.
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Affiliation(s)
- Cenyi Wang
- School of Physical Education and Sports Science, Soochow University, Suzhou, China
| | - Jiling Liang
- Tianjiu Research and Development Center for Exercise Nutrition and Foods, Hubei Key Laboratory of Exercise Training and Monitoring, College of Health Science, Wuhan Sports University, Wuhan, China
| | - Yuanyuan Ren
- School of Physical Education and Sports Science, Soochow University, Suzhou, China
| | - Jielun Huang
- Tianjiu Research and Development Center for Exercise Nutrition and Foods, Hubei Key Laboratory of Exercise Training and Monitoring, College of Health Science, Wuhan Sports University, Wuhan, China
| | - Baoming Jin
- School of Physical Education and Sports Science, Soochow University, Suzhou, China
| | - Guodong Wang
- School of Physical Education and Sports Science, Soochow University, Suzhou, China
- *Correspondence: Guodong Wang, ; Ning Chen,
| | - Ning Chen
- Tianjiu Research and Development Center for Exercise Nutrition and Foods, Hubei Key Laboratory of Exercise Training and Monitoring, College of Health Science, Wuhan Sports University, Wuhan, China
- *Correspondence: Guodong Wang, ; Ning Chen,
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Testa MTDJ, Cella PS, Marinello PC, Frajacomo FTT, Padilha CDS, Perandini PC, Moura FA, Duarte JA, Cecchini R, Guarnier FA, Deminice R. Resistance Training Attenuates Activation of STAT3 and Muscle Atrophy in Tumor-Bearing Mice. Front Oncol 2022; 12:880787. [PMID: 35847939 PMCID: PMC9283857 DOI: 10.3389/fonc.2022.880787] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 06/06/2022] [Indexed: 11/16/2022] Open
Abstract
Purpose Although the role of signal transducers and activators of transcription (STAT3) in cachexia due to the association of circulating IL-6 and muscle wasting has been extensively demonstrated, the effect of resistance training on STAT3 in mediating muscle atrophy in tumor-bearing mice is unknown. The aim of this study is to investigate the effects of resistance exercise training on inflammatory cytokines and oxidative-mediated STAT3 activation and muscle loss prevention in tumor-bearing mice. Methods Male Swiss mice were inoculated with Ehrlich tumor cells and exposed or not exposed to resistance exercise protocol of ladder climbing. Skeletal muscle STAT3 protein content was measured, compared between groups, and tested for possible association with plasma interleukins and local oxidative stress markers. Components of the ubiquitin-proteasome and autophagy pathways were assessed by real-time PCR or immunoblotting. Results Resistance training prevented STAT3 excessive activation in skeletal muscle mediated by the overabundance of plasma IL-6 and muscle oxidative stress. These mechanisms contributed to preventing the increased key genes and proteins of ubiquitin-proteasome and autophagy pathways in tumor-bearing mice, such as Atrogin-1, LC3B-II, and Beclin-1. Beyond preventing muscle atrophy, RT also prevented strength loss and impaired locomotor capacity, hallmarks of sarcopenia. Conclusion Our results suggest that STAT3 inhibition is central in resistance exercise protective effects against cancer-induced muscle atrophy and strength loss.
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Affiliation(s)
| | - Paola Sanches Cella
- Department of Physical Education, State University of Londrina, Londrina, Brazil
| | - Poliana Camila Marinello
- Department of Physical Education, State University of Londrina, Londrina, Brazil
- Department of General Pathology, State University of Londrina, Londrina, Brazil
| | | | - Camila de Souza Padilha
- Department of Physical Education, State University of Londrina, Londrina, Brazil
- Department of Physical Education, State University of São Paulo (UNESP), Presidente Prudente, Brazil
| | | | - Felipe Arruda Moura
- Department of Physical Education, State University of Londrina, Londrina, Brazil
| | | | - Rubens Cecchini
- Department of General Pathology, State University of Londrina, Londrina, Brazil
| | | | - Rafael Deminice
- Department of Physical Education, State University of Londrina, Londrina, Brazil
- *Correspondence: Rafael Deminice, ; orcid.org/0000-0002-9246-1079
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Pinto AP, Ropelle ER, Quadrilatero J, da Silva ASR. Physical Exercise and Liver Autophagy: Potential Roles of IL-6 and Irisin. Exerc Sport Sci Rev 2022; 50:89-96. [PMID: 34961755 DOI: 10.1249/jes.0000000000000278] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Autophagic dysregulation contributes to liver diseases. Although some investigations have examined the effects of endurance and resistance exercise on autophagy activation, potential myokines responsible for skeletal muscle-liver crosstalk are still unknown. Based on experimental studies and bioinformatics, we hypothesized that interleukin 6 (IL-6) and irisin might be key players in the contraction-induced release of molecules that regulate liver autophagic responses.
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Affiliation(s)
- Ana P Pinto
- Postgraduate Program in Rehabilitation and Functional Performance, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto São Paulo, Brazil
| | - Eduardo R Ropelle
- Laboratory of Molecular Biology of Exercise, School of Applied Sciences, University of Campinas, Limeira, São Paulo, Brazil
| | - Joe Quadrilatero
- Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada
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MORISASA M, YOSHIDA E, FUJITANI M, KIMURA K, UCHIDA K, KISHIDA T, MORI T, GOTO-INOUE N. Fish Protein Promotes Skeletal Muscle Hypertrophy via the Akt/mTOR Signaling Pathways. J Nutr Sci Vitaminol (Tokyo) 2022; 68:23-31. [DOI: 10.3177/jnsv.68.23] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Mizuki MORISASA
- Department of Marine Science and Resources, College of Bioresource Sciences, Nihon University
| | - Eriko YOSHIDA
- Functional Ingredient Research Section, Food Function R&D Center, Nippon Suisan Kaisha, Ltd
| | - Mina FUJITANI
- Laboratory of Nutrition Science, Division of Applied Bioscience, Graduate School of Agriculture, Ehime University
| | - Keisuke KIMURA
- Department of Marine Science and Resources, College of Bioresource Sciences, Nihon University
| | - Kenji UCHIDA
- Functional Ingredient Research Section, Food Function R&D Center, Nippon Suisan Kaisha, Ltd
| | - Taro KISHIDA
- Laboratory of Nutrition Science, Division of Applied Bioscience, Graduate School of Agriculture, Ehime University
| | - Tsukasa MORI
- Department of Marine Science and Resources, College of Bioresource Sciences, Nihon University
| | - Naoko GOTO-INOUE
- Department of Marine Science and Resources, College of Bioresource Sciences, Nihon University
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Higashida K, Inoue S, Takeuchi N, Ato S, Ogasawara R, Nakai N. Basal and resistance exercise-induced increase in protein synthesis is impaired in skeletal muscle of iron-deficient rats. Nutrition 2021; 91-92:111389. [PMID: 34303956 DOI: 10.1016/j.nut.2021.111389] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 05/14/2021] [Accepted: 06/05/2021] [Indexed: 01/07/2023]
Abstract
OBJECTIVES We aimed to investigate the effect of iron deficiency on basal- and contraction-induced increases in muscle protein synthesis. METHODS Four-wk-old male Sprague-Dawley rats were divided into three groups. The rats in two of the three groups had free access to a control diet (AD) or iron-deficient diet (ID) for 4 wk. The rats in the third group (CON) were pair-fed the control diet to the mean intake of the ID group. RESULTS In comparison with the CON group, the ID group showed significantly lower hematocrit and hemoglobin concentrations, iron-containing protein levels, and total iron content in skeletal muscle, but non-iron-containing protein levels did not show any differences between the groups. Protein synthesis, measured by puromycin-labeled peptides, was lower in the ID group compared with the CON group in both basal- and contraction-stimulated states. The ID diet impaired the activation levels of signaling pathways involved in protein synthesis, such as ribosomal protein S6 and eukaryotic translation initiation factor 4E-binding protein 1. Furthermore, dietary iron deficiency decreased autophagy capacity, but did not affect the ubiquitinated protein content. CONCLUSIONS These results suggest that severe iron deficiency decreases not only basal but also muscle contraction-induced increases in protein synthesis due to, at least in part, downregulation of the protein synthesis signaling pathway in the skeletal muscle.
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Affiliation(s)
- Kazuhiko Higashida
- Laboratory of Exercise Nutrition, Department of Nutrition, University of Shiga Prefecture, Japan.
| | - Sachika Inoue
- Laboratory of Exercise Nutrition, Department of Nutrition, University of Shiga Prefecture, Japan
| | - Nodoka Takeuchi
- Laboratory of Exercise Nutrition, Department of Nutrition, University of Shiga Prefecture, Japan
| | - Satoru Ato
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya, Japan
| | - Riki Ogasawara
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya, Japan
| | - Naoya Nakai
- Laboratory of Exercise Nutrition, Department of Nutrition, University of Shiga Prefecture, Japan
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Impact of Different Physical Exercises on the Expression of Autophagy Markers in Mice. Int J Mol Sci 2021; 22:ijms22052635. [PMID: 33807902 PMCID: PMC7962017 DOI: 10.3390/ijms22052635] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 12/27/2020] [Accepted: 12/28/2020] [Indexed: 12/14/2022] Open
Abstract
Although physical exercise-induced autophagy activation has been considered a therapeutic target to enhance tissue health and extend lifespan, the effects of different exercise models on autophagy in specific metabolic tissues are not completely understood. This descriptive investigation compared the acute effects of endurance (END), exhaustive (ET), strength (ST), and concurrent (CC) physical exercise protocols on markers of autophagy, genes, and proteins in the gastrocnemius muscle, heart, and liver of mice. The animals were euthanized immediately (0 h) and six hours (6 h) after the acute exercise for the measurement of glycogen levels, mRNA expression of Prkaa1, Ppargc1a, Mtor, Ulk1, Becn1, Atg5, Map1lc3b, Sqstm1, and protein levels of Beclin 1 and ATG5. The markers of autophagy were measured by quantifying the protein levels of LC3II and Sqstm1/p62 in response to three consecutive days of intraperitoneal injections of colchicine. In summary, for gastrocnemius muscle samples, the main alterations in mRNA expressions were observed after 6 h and for the ST group, and the markers of autophagy for the CC group were increased (i.e., LC3II and Sqstm1/p62). In the heart, the Beclin 1 and ATG5 levels were downregulated for the ET group. Regarding the markers of autophagy, the Sqstm1/p62 in the heart tissue was upregulated for the END and ST groups, highlighting the beneficial effects of these exercise models. The liver protein levels of ATG5 were downregulated for the ET group. After the colchicine treatment, the liver protein levels of Sqstm1/p62 were decreased for the END and ET groups compared to the CT, ST, and CC groups. These results could be related to diabetes and obesity development or liver dysfunction improvement, demanding further investigations.
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Nouri H, Sheikholeslami-Vatani D, Moloudi MR. Changes in UPR-PERK pathway and muscle hypertrophy following resistance training and creatine supplementation in rats. J Physiol Biochem 2021; 77:331-339. [PMID: 33635524 DOI: 10.1007/s13105-021-00801-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 02/15/2021] [Indexed: 10/22/2022]
Abstract
The unfolded protein response (UPR) plays a pivotal role in some exercise training-induced physiological adaptation. Our aim was to evaluate the changes in the protein kinase R-like endoplasmic reticulum kinase (PERK) arm of the UPR and hypertrophy signaling pathway following 8 weeks of resistance training and creatine (Cr) supplementation in rats. Thirty-two adult male Wistar rats (8 weeks old) were randomly divided into 4 groups of 8: untrained + placebo (UN+P), resistance training + placebo (RT+P), untrained + Cr (UN+Cr), and resistance training + Cr (RT+Cr). Trained animals were submitted to the ladder-climbing exercise training 5 days per week for a total of 8 weeks. Cr supplementation groups received creatine diluted with 1.5 ml of 5% dextrose orally. The flexor hallucis longus (FHL) muscle was extracted 48 h after the last training session and used for western blotting. After training period, the RT+Cr and RT+P groups presented a significant increase in phosphorylated and phosphorylated/total ratio hypertrophy indices, phosphorylated and phosphorylated/total ratio PERK pathway proteins, and other downstream proteins of the PERK cascade compared with their untrained counterparts (P < 0.05). The increase in hypertrophy indices were higher but PERK pathway proteins were lower in the RT-Cr group than in the RT+P group (P < 0.05). There was no significant difference between the untrained groups (P > 0.05). Our study suggests that resistance training in addition to Cr supplementation modifies PERK pathway response and improves skeletal muscle hypertrophy.
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Affiliation(s)
- Hersh Nouri
- Department of Physical Education and Sport Sciences, University of Kurdistan, Sanandaj, Iran
| | | | - Mohammad Raman Moloudi
- Liver and Digestive Research Center, Research Institute for Health Development, Kurdistan University of Medical Sciences, Sanandaj, Iran
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Kwon I, Song W, Jang Y, Choi MD, Vinci DM, Lee Y. Elevation of hepatic autophagy and antioxidative capacity by endurance exercise is associated with suppression of apoptosis in mice. Ann Hepatol 2021; 19:69-78. [PMID: 31611063 DOI: 10.1016/j.aohep.2019.08.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 08/16/2019] [Accepted: 08/18/2019] [Indexed: 02/04/2023]
Abstract
INTRODUCTION AND OBJECTIVES Endurance exercise (EXE) has emerged as a potent inducer of autophagy essential in maintaining cellular homeostasis in various tissues; however, the functional significance and molecular mechanisms of EXE-induced autophagy in the liver remain unclear. Thus, the aim of this study is to examine the signaling nexus of hepatic autophagy pathways occurring during acute EXE and a potential crosstalk between autophagy and apoptosis. MATERIALS AND METHODS C57BL/6 male mice were randomly assigned to sedentary control group (CON, n=9) and endurance exercise (EXE, n=9). Mice assigned to EXE were gradually acclimated to treadmill running and ran for 60min per day for five consecutive days. RESULTS Our data showed that EXE promoted hepatic autophagy via activation of canonical autophagy signaling pathways via mediating microtubule-associated protein B-light chain 3 II (LC3-II), autophagy protein 7 (ATG7), phosphorylated adenosine mono phosphate-activated protein kinase (p-AMPK), CATHEPSIN L, lysosome-associated membrane protein 2 (LAMP2), and a reduction in p62. Interestingly, this autophagy promotion concurred with enhanced anabolic activation via AKT-mammalian target of rapamycin (mTOR)-p70S6K signaling cascade and enhanced antioxidant capacity such as copper zinc superoxide dismutase (CuZnSOD), glutathione peroxidase (GPX), and peroxiredoxin 3 (PRX3), known to be as antagonists of autophagy. Moreover, exercise-induced autophagy was inversely related to apoptosis in the liver. CONCLUSIONS Our findings indicate that improved autophagy and antioxidant capacity, and potentiated anabolic signaling may be a potent non-pharmacological therapeutic strategy against diverse liver diseases.
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Affiliation(s)
- Insu Kwon
- Molecular and Cellular Exercise Physiology Laboratory, Department of Movement Sciences and Health, Usha Kundu, MD College of Health, University of West Florida, Pensacola, FLUSA
| | - Wankeun Song
- Molecular and Cellular Exercise Physiology Laboratory, Department of Movement Sciences and Health, Usha Kundu, MD College of Health, University of West Florida, Pensacola, FLUSA
| | - Yongchul Jang
- Molecular and Cellular Exercise Physiology Laboratory, Department of Movement Sciences and Health, Usha Kundu, MD College of Health, University of West Florida, Pensacola, FLUSA
| | - Myung D Choi
- Exercise Science, School of Health Sciences, Oakland University, Rochester, MIUSA
| | - Debra M Vinci
- Molecular and Cellular Exercise Physiology Laboratory, Department of Movement Sciences and Health, Usha Kundu, MD College of Health, University of West Florida, Pensacola, FLUSA
| | - Youngil Lee
- Molecular and Cellular Exercise Physiology Laboratory, Department of Movement Sciences and Health, Usha Kundu, MD College of Health, University of West Florida, Pensacola, FLUSA.
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Arias C, Saavedra N, Leal K, Vásquez B, Abdalla DSP, Salazar LA. Histological Evaluation and Gene Expression Profiling of Autophagy-Related Genes for Cartilage of Young and Senescent Rats. Int J Mol Sci 2020; 21:ijms21228607. [PMID: 33203108 PMCID: PMC7697851 DOI: 10.3390/ijms21228607] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 11/13/2020] [Accepted: 11/13/2020] [Indexed: 01/06/2023] Open
Abstract
Autophagy is a cellular mechanism that protects cells from stress by digesting non-functional cellular components. In the cartilage, chondrocytes depend on autophagy as a principal mechanism to maintain cellular homeostasis. This protective role diminishes prior to the structural damage that normally occurs during aging. Considering that aging is the main risk factor for osteoarthritis, evaluating the expression of genes associated with autophagy in senescent cartilage might allow for the identification of potential therapeutic targets for treatment. Thus, we studied two groups of young and senescent rats. A histological analysis of cartilage and gene expression quantification for autophagy-related genes were performed. In aged cartilage, morphological changes were observed, such as an increase in cartilage degeneration as measured by the modified Mankin score, a decrease in the number of chondrocytes and collagen II (Col2a1), and an increase in matrix metalloproteinase 13 (Mmp13). Moreover, 84 genes associated with autophagy were evaluated by a PCR array analysis, and 15 of them were found to be significantly decreased with aging. Furthermore, an in silico analysis based on by two different bioinformatics software tools revealed that several processes including cellular homeostasis, autophagosome assembly, and aging—as well as several biological pathways such as autophagy, insulin-like growth factor 1 (IGF-1) signaling, PI3K (phosphoinositide 3-kinase)/AKT (serine/threonine kinase) signaling, and mammalian target of rapamycin (mTOR) signaling—were enriched. In conclusion, the analysis identified some potential targets for osteoarthritis treatment that would allow for the development of new therapeutic strategies for this chronic disease.
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Affiliation(s)
- Consuelo Arias
- Center of Molecular Biology and Pharmacogenetics, Scientific and Technological Bioresource Nucleus, Universidad de La Frontera, Av. Francisco Salazar 01145, Temuco 4811230, Chile; (C.A.); (N.S.); (K.L.)
- Carrera de Kinesiología, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Av. Alemania 1090, Temuco 4810101, Chile
| | - Nicolás Saavedra
- Center of Molecular Biology and Pharmacogenetics, Scientific and Technological Bioresource Nucleus, Universidad de La Frontera, Av. Francisco Salazar 01145, Temuco 4811230, Chile; (C.A.); (N.S.); (K.L.)
| | - Karla Leal
- Center of Molecular Biology and Pharmacogenetics, Scientific and Technological Bioresource Nucleus, Universidad de La Frontera, Av. Francisco Salazar 01145, Temuco 4811230, Chile; (C.A.); (N.S.); (K.L.)
| | - Bélgica Vásquez
- Facultad de Ciencias de la Salud, Universidad de Tarapacá, Av. General Velásquez 1775, Arica 1000007, Chile;
| | - Dulcineia S. P. Abdalla
- Department of Clinical and Toxicological Analyses, Faculty of Pharmaceutical Sciences, Universidade de São Paulo, Avenida Professor Lineu Prestes 580, São Paulo CEP 05508-000, SP, Brazil;
| | - Luis A. Salazar
- Center of Molecular Biology and Pharmacogenetics, Scientific and Technological Bioresource Nucleus, Universidad de La Frontera, Av. Francisco Salazar 01145, Temuco 4811230, Chile; (C.A.); (N.S.); (K.L.)
- Correspondence: ; Tel.: +56-45-259-6724
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14
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Lourenço Í, Krause Neto W, dos Santos Portella Amorim L, Moraes Munhoz Ortiz V, Lopes Geraldo V, Henrique da Silva Ferreira G, Chagas Caperuto É, Florencio Gama E. Muscle hypertrophy and ladder-based resistance training for rodents: A systematic review and meta-analysis. Physiol Rep 2020; 8:e14502. [PMID: 32889774 PMCID: PMC7507488 DOI: 10.14814/phy2.14502] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 06/02/2020] [Accepted: 06/09/2020] [Indexed: 12/20/2022] Open
Abstract
This study aimed to review the effects of ladder-based resistance training (LRT) on muscle hypertrophy and strength in rodents through a systematic review with meta-analysis. We systematically searched PubMed/Medline, SportDiscuss, Scopus, Google Scholar, Science Direct, and Scielo database on May 18, 2020. Thirty-four studies were included measuring total (mCSA) or mean muscle fibers cross-sectional area (fCSA) or maximum load-carrying capacity (MLCC) or muscle mass (MM). About the main results, LRT provides sufficient mechanical stimulation to increase mCSA and fCSA. Meta-analysis showed a significant overall effect on the fCSA (SMD 1.89, 95% CI [1.18, 2.61], p < .00001, I2 = 85%); however, subgroup analysis showed that some muscle types might not be hypertrophied through the LRT. Meta-analysis showed a significant training effect on the MM (SMD 0.92, 95% CI [0.52, 1.32], p < .00001, I2 = 72%). Sub-group analysis revealed that soleus (SMD 1.32, 95% CI [0.11, 2.54], p = .03, I2 = 86%) and FHL (SMD 1.92, 95% CI [1.00, 2.85], p < .0001, I2 = 71%) presented significant training effects, despite moderate heterogeneity levels (I2 = 72%). MLCC increases considerably after a period of LRT, regardless of its duration and the characteristics of the protocols (SMD 12.37, 95% CI [9.36, 15.37], p < .00001, I2 = 90%). Through these results, we reach the following conclusions: (a) LRT is efficient to induce muscle hypertrophy, although this effect varies between different types of skeletal muscles, and; (b) the ability of rodents to carry load increases regardless of the type and duration of the protocol used.
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Affiliation(s)
- Ítalo Lourenço
- Department of Physical EducationLaboratory of Morphoquantitative Studies and ImmunohistochemistryUniversidade São Judas TadeuSão PauloSPBrazil
| | - Walter Krause Neto
- Department of Physical EducationLaboratory of Morphoquantitative Studies and ImmunohistochemistryUniversidade São Judas TadeuSão PauloSPBrazil
| | - Laura dos Santos Portella Amorim
- Department of Physical EducationLaboratory of Morphoquantitative Studies and ImmunohistochemistryUniversidade São Judas TadeuSão PauloSPBrazil
| | - Vagner Moraes Munhoz Ortiz
- Department of Physical EducationLaboratory of Morphoquantitative Studies and ImmunohistochemistryUniversidade São Judas TadeuSão PauloSPBrazil
| | - Vitor Lopes Geraldo
- Department of Physical EducationLaboratory of Morphoquantitative Studies and ImmunohistochemistryUniversidade São Judas TadeuSão PauloSPBrazil
| | - Gabriel Henrique da Silva Ferreira
- Department of Physical EducationLaboratory of Morphoquantitative Studies and ImmunohistochemistryUniversidade São Judas TadeuSão PauloSPBrazil
| | - Érico Chagas Caperuto
- Department of Physical EducationLaboratory of Human MovimentUniversidade São Judas TadeuSão PauloSPBrazil
| | - Eliane Florencio Gama
- Department of Physical EducationLaboratory of Morphoquantitative Studies and ImmunohistochemistryUniversidade São Judas TadeuSão PauloSPBrazil
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15
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Abou Sawan S, Mazzulla M, Moore DR, Hodson N. More than just a garbage can: emerging roles of the lysosome as an anabolic organelle in skeletal muscle. Am J Physiol Cell Physiol 2020; 319:C561-C568. [PMID: 32726158 DOI: 10.1152/ajpcell.00241.2020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Skeletal muscle is a highly plastic tissue capable of remodeling in response to a range of physiological stimuli, including nutrients and exercise. Historically, the lysosome has been considered an essentially catabolic organelle contributing to autophagy, phagocytosis, and exo-/endocytosis in skeletal muscle. However, recent evidence has emerged of several anabolic roles for the lysosome, including the requirement for autophagy in skeletal muscle mass maintenance, the discovery of the lysosome as an intracellular signaling hub for mechanistic target of rapamycin complex 1 (mTORC1) activation, and the importance of transcription factor EB/lysosomal biogenesis-related signaling in the regulation of mTORC1-mediated protein synthesis. We, therefore, propose that the lysosome is an understudied organelle with the potential to underpin the skeletal muscle adaptive response to anabolic stimuli. Within this review, we describe the molecular regulation of lysosome biogenesis and detail the emerging anabolic roles of the lysosome in skeletal muscle with particular emphasis on how these roles may mediate adaptations to chronic resistance exercise. Furthermore, given the well-established role of amino acids to support muscle protein remodeling, we describe how dietary proteins "labeled" with stable isotopes could provide a complementary research tool to better understand how lysosomal biogenesis, autophagy regulation, and/or mTORC1-lysosomal repositioning can mediate the intracellular usage of dietary amino acids in response to anabolic stimuli. Finally, we provide avenues for future research with the aim of elucidating how the regulation of this important organelle could mediate skeletal muscle anabolism.
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Affiliation(s)
- Sidney Abou Sawan
- Department of Exercise Science, Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada
| | - Michael Mazzulla
- Department of Exercise Science, Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada
| | - Daniel R Moore
- Department of Exercise Science, Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada
| | - Nathan Hodson
- Department of Exercise Science, Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada
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16
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Effects of high intensity interval training (up & downward running) with BCAA/nano chitosan on Foxo3 and SMAD soleus muscles of aging rat. Life Sci 2020; 252:117641. [PMID: 32272182 DOI: 10.1016/j.lfs.2020.117641] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 03/31/2020] [Accepted: 04/02/2020] [Indexed: 01/14/2023]
Abstract
AIMS The aim of this study was investigate the effects of 8 weeks of high intensity interval training (HIIT, up & downward running) with BCAA/nano chitosan on Foxo3 and SMAD soleus muscles of aging rats. MAIN METHODS In this experimental study thirty male rats were randomly divided into six groups of control, BCAA with Nano chitosan (Supplement, (Sup)), upslope running, downslope running, upslope running+Sup, and downslope running+Sup that each groups consist of 6 rats. The exercise training was performed HIIT 8 weeks 3 session per weeks with incrementally intensity 12 to 52 m/m in 7sets (Slop 0 to 15o) during 8 weeks. BCAA coated with chitosan nanoparticles (84 mg/kg) and gavage to supplementation groups, 3 days per weeks for eight weeks. The animals were feed with standard rat chow (Normal diet, 2.87 kcal/g, 15% of energy from fat). At the end of protocol the rat was sacrifice and soleus muscle was fix and frieze for IHC with H&E and gene expression analysis. KEY FINDINGS The results of this study showed that Foxo3 gene expression in the Upslope running + Sup and Downslope running + Sup groups showed a significant decrease (p ≤ 0.05) compared to the control group. The mRNA of Smad also showed that only the Upslope running + Sup group had a significant decrease compared to the control group (p ≤ 0.05). SIGNIFICANCE It seems that, BCAA/nano chitosan supplementation along with exercise training in a variety of ways (Up & down slope running) can control the damage caused by Foxo3 and Smad transcription factors. That, control of these factors can minimize age-related atrophy.
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17
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Takegaki J, Ogasawara R, Kotani T, Tamura Y, Takagi R, Nakazato K, Ishii N. Influence of shortened recovery between resistance exercise sessions on muscle-hypertrophic effect in rat skeletal muscle. Physiol Rep 2020; 7:e14155. [PMID: 31250976 PMCID: PMC6598394 DOI: 10.14814/phy2.14155] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2019] [Accepted: 06/07/2019] [Indexed: 12/29/2022] Open
Abstract
Resistance exercise training induces muscle hypertrophy, and recovery between sessions is one of the major determinants of this effect. However, the effect of the recovery period between sessions on muscle hypertrophy following resistance exercise training remains unclear. To elucidate the effect of recovery period on hypertrophy, in the present study, we investigated changes in protein degradation systems and hypertrophic responses in rat skeletal muscle to resistance training with variable recovery periods. In the conventional recovery group (exercised every 72 h) and a shorter recovery group (exercised every 24 h), 18 bouts of resistance exercise consisting of 50 repetitions of a 3-sec maximal isometric contraction caused muscle hypertrophy and slight activation of muscle protein degradation systems. By contrast, in an excessively shorter recovery group (exercised every 8 h), 18 bouts of resistance exercise did not cause hypertrophy and markedly activated protein degradation systems, accompanied by inflammatory responses. These observations indicate that excessive shortening of recovery between sessions does not cause skeletal muscle hypertrophy, likely due to the activation of proteolysis induced by inflammatory responses to resistance exercise training.
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Affiliation(s)
- Junya Takegaki
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan.,Ritsumeikan Global Innovation Research Organization, Ritsumeikan University, Kusatsu, Shiga, Japan
| | - Riki Ogasawara
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya, Japan
| | - Takaya Kotani
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan
| | - Yuki Tamura
- Graduate School of Health and Sport Science, Nippon Sport Science University, Tokyo, Japan
| | - Ryo Takagi
- Graduate School of Health and Sport Science, Nippon Sport Science University, Tokyo, Japan
| | - Koichi Nakazato
- Graduate School of Health and Sport Science, Nippon Sport Science University, Tokyo, Japan
| | - Naokata Ishii
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan
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18
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Cui D, Drake JC, Wilson RJ, Shute RJ, Lewellen B, Zhang M, Zhao H, Sabik OL, Onengut S, Berr SS, Rich SS, Farber CR, Yan Z. A novel voluntary weightlifting model in mice promotes muscle adaptation and insulin sensitivity with simultaneous enhancement of autophagy and mTOR pathway. FASEB J 2020; 34:7330-7344. [PMID: 32304342 DOI: 10.1096/fj.201903055r] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 02/17/2020] [Accepted: 03/04/2020] [Indexed: 12/23/2022]
Abstract
Our understanding of the molecular mechanisms underlying adaptations to resistance exercise remains elusive despite the significant biological and clinical relevance. We developed a novel voluntary mouse weightlifting model, which elicits squat-like activities against adjustable load during feeding, to investigate the resistance exercise-induced contractile and metabolic adaptations. RNAseq analysis revealed that a single bout of weightlifting induced significant transcriptome responses of genes that function in posttranslational modification, metabolism, and muscle differentiation in recruited skeletal muscles, which were confirmed by increased expression of fibroblast growth factor-inducible 14 (Fn14), Down syndrome critical region 1 (Dscr1) and Nuclear receptor subfamily 4, group A, member 3 (Nr4a3) genes. Long-term (8 weeks) voluntary weightlifting training resulted in significantly increases of muscle mass, protein synthesis (puromycin incorporation in SUnSET assay) and mTOR pathway protein expression (raptor, 4e-bp-1, and p70S6K proteins) along with enhanced muscle power (specific torque and contraction speed), but not endurance capacity, mitochondrial biogenesis, and fiber type transformation. Importantly, weightlifting training profound improved whole-body glucose clearance and skeletal muscle insulin sensitivity along with enhanced autophagy (increased LC3 and LC3-II/I ratio, and decreased p62/Sqstm1). These data suggest that resistance training in mice promotes muscle adaptation and insulin sensitivity with simultaneous enhancement of autophagy and mTOR pathway.
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Affiliation(s)
- Di Cui
- Center for Skeletal Muscle Research at Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA, USA.,Key Laboratory of Adolescent and Exercise Intervention, Ministry of Education, East China Normal University, Shanghai, China
| | - Joshua C Drake
- Center for Skeletal Muscle Research at Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Rebecca J Wilson
- Center for Skeletal Muscle Research at Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA, USA.,Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Robert J Shute
- Center for Skeletal Muscle Research at Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Bevan Lewellen
- Center for Skeletal Muscle Research at Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Mei Zhang
- Center for Skeletal Muscle Research at Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA, USA.,Departments of Medicine, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Henan Zhao
- Center for Skeletal Muscle Research at Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Olivia L Sabik
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA, USA.,Center for Public Health Genomics, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Suna Onengut
- Center for Public Health Genomics, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Stuart S Berr
- Department of Radiology and Medical Imaging, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Stephen S Rich
- Center for Public Health Genomics, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Charles R Farber
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA, USA.,Center for Public Health Genomics, University of Virginia School of Medicine, Charlottesville, VA, USA.,Department of Public Health Sciences, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Zhen Yan
- Center for Skeletal Muscle Research at Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA, USA.,Departments of Medicine, University of Virginia School of Medicine, Charlottesville, VA, USA.,Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA, USA.,Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, VA, USA
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19
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Pinto AP, Vieira TS, Marafon BB, Batitucci G, Cabrera EMB, da Rocha AL, Kohama EB, Rodrigues KCC, de Moura LP, Pauli JR, Cintra DE, Ropelle ER, de Freitas EC, da Silva ASR. The Combination of Fasting, Acute Resistance Exercise, and Protein Ingestion Led to Different Responses of Autophagy Markers in Gastrocnemius and Liver Samples. Nutrients 2020; 12:nu12030641. [PMID: 32121154 PMCID: PMC7146592 DOI: 10.3390/nu12030641] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 02/25/2020] [Accepted: 02/26/2020] [Indexed: 12/02/2022] Open
Abstract
The present study verified the responses of proteins related to the autophagy pathway after 10 h of fast with resistance exercise and protein ingestion in skeletal muscle and liver samples. The rats were distributed into five experimental groups: control (CT; sedentary and without gavage after fast), exercise immediately (EXE-imm; after fast, rats were submitted to the resistance protocol and received water by gavage immediately after exercise), exercise after 1 h (EXE-1h; after fast, rats were submitted to the resistance protocol and received water by gavage 1 h after exercise), exercise and supplementation immediately after exercise (EXE/Suppl-imm; after fast, rats were submitted to the resistance protocol and received a mix of casein: whey protein 1:1 (w/w) by gavage immediately after exercise), exercise and supplementation 1 h after exercise (EXE/Suppl-1h; after fast, rats were submitted to the resistance protocol and received a mix of casein: whey protein 1:1 (w/w) by gavage 1 h after exercise). In summary, the current findings show that the combination of fasting, acute resistance exercise, and protein blend ingestion (immediately or 1 h after the exercise stimulus) increased the serum levels of leucine, insulin, and glucose, as well as the autophagy protein contents in skeletal muscle, but decreased other proteins related to the autophagic pathway in the liver. These results deserve further mechanistic investigations since athletes are combining fasting with physical exercise to enhance health and performance outcomes.
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Affiliation(s)
- Ana P. Pinto
- Postgraduate Program in Rehabilitation and Functional Performance, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, São Paulo 14049-900, Brazil; (A.P.P.); (A.L.d.R.); (E.B.K.)
| | - Tales S. Vieira
- Postgraduate Program in Nutritional Science, State University of São Paulo Júlio de Mesquita Filho (Araraquara). Araraquara, São Paulo 14800-903, Brazil; (T.S.V.); (G.B.); (E.C.d.F.)
| | - Bruno B. Marafon
- School of Physical Education and Sport of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, São Paulo 14040-907, Brazil;
| | - Gabriela Batitucci
- Postgraduate Program in Nutritional Science, State University of São Paulo Júlio de Mesquita Filho (Araraquara). Araraquara, São Paulo 14800-903, Brazil; (T.S.V.); (G.B.); (E.C.d.F.)
| | - Elisa M. B. Cabrera
- Institute of Translational Nutrigenetics and Nutrigenomics, Department of Molecular Biology and Genomics, Health Sciences University Center, University of Guadalajara, Guadalajara 44100, Mexico;
| | - Alisson L. da Rocha
- Postgraduate Program in Rehabilitation and Functional Performance, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, São Paulo 14049-900, Brazil; (A.P.P.); (A.L.d.R.); (E.B.K.)
| | - Eike B. Kohama
- Postgraduate Program in Rehabilitation and Functional Performance, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, São Paulo 14049-900, Brazil; (A.P.P.); (A.L.d.R.); (E.B.K.)
| | - Kellen C. C. Rodrigues
- Laboratory of Molecular Biology of Exercise (LaBMEx), School of Applied Sciences, University of Campinas (UNICAMP), Limeira, São Paulo 13484-350, Brazil; (K.C.C.R.); (L.P.d.M.); (J.R.P.); (D.E.C.); (E.R.R.)
| | - Leandro P. de Moura
- Laboratory of Molecular Biology of Exercise (LaBMEx), School of Applied Sciences, University of Campinas (UNICAMP), Limeira, São Paulo 13484-350, Brazil; (K.C.C.R.); (L.P.d.M.); (J.R.P.); (D.E.C.); (E.R.R.)
| | - José R. Pauli
- Laboratory of Molecular Biology of Exercise (LaBMEx), School of Applied Sciences, University of Campinas (UNICAMP), Limeira, São Paulo 13484-350, Brazil; (K.C.C.R.); (L.P.d.M.); (J.R.P.); (D.E.C.); (E.R.R.)
| | - Dennys E. Cintra
- Laboratory of Molecular Biology of Exercise (LaBMEx), School of Applied Sciences, University of Campinas (UNICAMP), Limeira, São Paulo 13484-350, Brazil; (K.C.C.R.); (L.P.d.M.); (J.R.P.); (D.E.C.); (E.R.R.)
| | - Eduardo R. Ropelle
- Laboratory of Molecular Biology of Exercise (LaBMEx), School of Applied Sciences, University of Campinas (UNICAMP), Limeira, São Paulo 13484-350, Brazil; (K.C.C.R.); (L.P.d.M.); (J.R.P.); (D.E.C.); (E.R.R.)
| | - Ellen C. de Freitas
- Postgraduate Program in Nutritional Science, State University of São Paulo Júlio de Mesquita Filho (Araraquara). Araraquara, São Paulo 14800-903, Brazil; (T.S.V.); (G.B.); (E.C.d.F.)
- School of Physical Education and Sport of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, São Paulo 14040-907, Brazil;
| | - Adelino S. R. da Silva
- Postgraduate Program in Rehabilitation and Functional Performance, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, São Paulo 14049-900, Brazil; (A.P.P.); (A.L.d.R.); (E.B.K.)
- School of Physical Education and Sport of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, São Paulo 14040-907, Brazil;
- Correspondence: ; Tel.: +55-16-33150522; Fax: +55-16-33150551
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20
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Goutianos G, Margaritelis NV, Sparopoulou T, Veskoukis AS, Vrabas IS, Paschalis V, Nikolaidis MG, Kyparos A. Chronic administration of plasma from exercised rats to sedentary rats does not induce redox and metabolic adaptations. J Physiol Sci 2020; 70:3. [PMID: 32039695 PMCID: PMC6995785 DOI: 10.1186/s12576-020-00737-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 01/22/2020] [Indexed: 12/15/2022]
Abstract
The present study aimed to investigate whether endurance exercise-induced changes in blood plasma composition may lead to adaptations in erythrocytes, skeletal muscle and liver. Forty sedentary rats were randomly distributed into two groups: a group that was injected with pooled plasma from rats that swam until exhaustion and a group that was injected with the pooled plasma from resting rats (intravenous administration at a dose of 2 mL/kg body weight for 21 days). Total antioxidant capacity, malondialdehyde and protein carbonyls were higher in the plasma collected from the exercised rats compared to the plasma from the resting rats. Νo significant difference was found in blood and tissue redox biomarkers and in tissue metabolic markers between rats that received the "exercised" or the "non-exercised" plasma (P > 0.05). Our results demonstrate that plasma injections from exercised rats to sedentary rats do not induce redox or metabolic adaptations in erythrocytes, skeletal muscle and liver.
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Affiliation(s)
- Georgios Goutianos
- Department of Physical Education and Sport Science at Serres, Aristotle University of Thessaloniki, Agios Ioannis, 62110, Serres, Greece
| | - Nikos V Margaritelis
- Department of Physical Education and Sport Science at Serres, Aristotle University of Thessaloniki, Agios Ioannis, 62110, Serres, Greece.,Intensive Care Unit, 424 General Military Hospital of Thessaloniki, Thessaloniki, Greece
| | - Theodora Sparopoulou
- Department of Physical Education and Sport Science at Serres, Aristotle University of Thessaloniki, Agios Ioannis, 62110, Serres, Greece.,Department of Animal Structure and Function, School of Veterinary Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Aristidis S Veskoukis
- Department of Physical Education and Sport Science at Serres, Aristotle University of Thessaloniki, Agios Ioannis, 62110, Serres, Greece.,Department of Biochemistry and Biotechnology, University of Thessaly, Larissa, Greece
| | - Ioannis S Vrabas
- Department of Physical Education and Sport Science at Serres, Aristotle University of Thessaloniki, Agios Ioannis, 62110, Serres, Greece
| | - Vassilis Paschalis
- School of Physical Education and Sport Science, National and Kapodistrian University of Athens, Athens, Greece
| | - Michalis G Nikolaidis
- Department of Physical Education and Sport Science at Serres, Aristotle University of Thessaloniki, Agios Ioannis, 62110, Serres, Greece
| | - Antonios Kyparos
- Department of Physical Education and Sport Science at Serres, Aristotle University of Thessaloniki, Agios Ioannis, 62110, Serres, Greece.
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21
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Liang J, Zeng Z, Zhang Y, Chen N. Regulatory role of exercise-induced autophagy for sarcopenia. Exp Gerontol 2019; 130:110789. [PMID: 31765742 DOI: 10.1016/j.exger.2019.110789] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Revised: 10/24/2019] [Accepted: 11/20/2019] [Indexed: 12/21/2022]
Abstract
Sarcopenia is an aging-related disease, described as the progressive reduction in mass and strength of skeletal muscle. Sarcopenia is typically characterized as the accumulation of damaged products due to an imbalance between protein synthesis and protein degradation. This imbalance between protein synthesis and degradation is attributed to impaired autophagic signal pathways. Sarcopenia can predispose elderly patients to several complications that may significantly impact patient quality of life. Recent evidence indicates that autophagy is required for the control of skeletal muscle mass under catabolic conditions and plays a crucial role in maintaining the homeostasis and integrity of skeletal muscle, specifically at appropriate level of autophagy. Exercise may be considered as a stress stimulus that can substantially modulate cellular signaling to promote metabolic adaptations. Appropriate exercise can induce autophagy or regulate the functional status of autophagy. Additionally, exercise-induced autophagy is the most effective treatment available in slowing down sarcopenia, improving mitochondrial quality, and the number of quiescent satellite cells, as a process that depends on basal autophagy. The molecular mechanisms underpinning the development of sarcopenia, however, remained largely unknown. In this narrative review, the current molecular mechanisms of sarcopenia are discussed from the perspective of exercise-induced autophagy and the effect of different exercise modalities on this response. This narrative review will aim to provide the references for developing scientific and optimal intervention strategies including exercise intervention for the prevention and treatment of sarcopenia through regulating autophagic signal pathways.
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Affiliation(s)
- Jiling Liang
- Graduate School, Wuhan Sports University, Wuhan 430079, China
| | - Zhengzhong Zeng
- Graduate School, Wuhan Sports University, Wuhan 430079, China
| | - Ying Zhang
- Graduate School, Wuhan Sports University, Wuhan 430079, China
| | - Ning Chen
- Tianjiu Research and Development Center for Exercise Nutrition and Foods, Hubei Key Laboratory of Exercise Training and Monitoring, College of Health Science, Wuhan Sports University, Wuhan 430079, China.
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22
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Guzzoni V, Briet L, Costa R, Souza RWA, Carani FR, Dal-Pai-Silva M, Silva KAS, Cunha TS, Marcondes FK. Intense resistance training induces pronounced metabolic stress and impairs hypertrophic response in hind-limb muscles of rats. Stress 2019; 22:377-386. [PMID: 30857457 DOI: 10.1080/10253890.2019.1573364] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Skeletal muscle hypertrophy is an exercise-induced adaptation, particularly in resistance training (RT) programs that use large volumes and low loads. However, evidence regarding the role of rest intervals on metabolic stress and muscular adaptations is inconclusive. Thus, we aimed to investigate the effects of a strenuous RT model (jump-training) on skeletal muscle adaptations and metabolic stress, considering the scarce information about RT models for rats. We hypothesized that jump-training induces metabolic stress and influences negatively the growth of soleus (SOL) and extensor digitorum longus (EDL) muscles of rats. Male Wistar rats (aged 60 days) were randomly assigned to non-trained or trained groups (n = 8/group). Trained rats performed jump-training during 5 days a week for 1, 3, or 5 weeks with 30 s of inter-set rest intervals. Forty-eight hours after the experimental period, rats were euthanized and blood samples immediately drawn to measure creatine kinase activity, lactate and corticosterone concentrations. Muscle weight-to-body weight ratio (MW/BW), cross-sectional area (CSA) and myosin heavy chain (MHC) isoform expression were determined. Higher lactate levels occurred after 20 min of training in weeks 1 and 3. Corticosterone levels were higher after 5 weeks of training. Jump-training had negative effects on hypertrophy of types-I and II muscle fibers after 5 weeks of training, as evidenced by decreased CSA and reduced muscle weight. Our results demonstrated that pronounced metabolic stress and impairment of muscle growth might take place when variables of exercise training are not appropriately manipulated. Lay summary Resistance training (RT) has been used to increase muscle mass. In this regard, training variables (intensity, volume, and frequency) must be strictly controlled in order to evoke substantial muscular fitness. This study shows that rats submitted to 5 weeks of intensive resistance jump-training - high intensity, large volume, and short rest intervals - present high levels of blood corticosterone associated with negative effects on hypertrophy of types-I and II muscle fibers.
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Affiliation(s)
- Vinicius Guzzoni
- a Department of Physiological Sciences , Piracicaba Dental School, University of Campinas , Piracicaba , Brazil
- b Department of Cellular and Molecular Biology , Federal University of Paraíba , João Pessoa , Brazil
| | - Larissa Briet
- c Institute of Biology , University of Campinas , Campinas , Brazil
| | - Rafaela Costa
- a Department of Physiological Sciences , Piracicaba Dental School, University of Campinas , Piracicaba , Brazil
| | - Rodrigo W A Souza
- d Department of Morphology, Institute of Biosciences , São Paulo State University , Botucatu , Brazil
| | - Fernanda R Carani
- d Department of Morphology, Institute of Biosciences , São Paulo State University , Botucatu , Brazil
| | - Maeli Dal-Pai-Silva
- d Department of Morphology, Institute of Biosciences , São Paulo State University , Botucatu , Brazil
| | - Kleiton A S Silva
- e Department of Medicine , University of Missouri School of Medicine , Columbia , MO, USA
| | - Tatiana S Cunha
- f Science and Technology Institute , Federal University of São Paulo , São José dos Campos , Brazil
| | - Fernanda K Marcondes
- a Department of Physiological Sciences , Piracicaba Dental School, University of Campinas , Piracicaba , Brazil
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23
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Garza MA, Wason EA, Cruger JR, Chung E, Zhang JQ. Strength training attenuates post-infarct cardiac dysfunction and remodeling. J Physiol Sci 2019; 69:523-530. [PMID: 30911900 PMCID: PMC10717786 DOI: 10.1007/s12576-019-00672-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 03/09/2019] [Indexed: 01/30/2023]
Abstract
Post-myocardial infarction (MI) exercise has been employed to improve cardiac function. However, most studies have focused on endurance training (Et). Although Et has been reported to preserve cardiac function, evidence suggests that Et increases left ventricle (LV) interior dimensions as a result of albumin-induced plasma expansion. In contrast, strength training (St) induces concentric cardiac hypertrophy and improved cardiac function without causing ventricular dilation. Therefore, the purpose of this study was to investigate the effects of St on cardiac function and remodeling in rats with MI. MI was surgically induced in 7-week-old rats via ligation of the coronary artery. Survivors were assigned to two experimental groups, MI-Sed (No exercise; n = 9), MI-St (St; n = 10), with a Sham group (no MI, no St; n = 9). MI-St rats began training 1-week post-MI by climbing a ladder with weights for 10 weeks. Echocardiographic measurements were performed prior to, and following exercise training, while in vivo LV hemodynamic analysis was conducted at the end of the experimental period. Our data revealed that St induced shortening of the LV end-diastolic dimension in the MI-St group compared with the MI-Sed group (P < 0.05). The peak velocities of contraction (+ dP/dt max) and relaxation (- dP/dt max) were significantly greater in the MI-St group than the MI-Sed group (P < 0.05). These training effects contributed to the improved fractional shortening (%FS). Our results demonstrate that St may be beneficial for post-MI by attenuating LV dilation and concomitant cardiac dysfunction associated with MI.
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Affiliation(s)
- Michael A Garza
- Laboratory of Cardiovascular Research, Department of Health, Kinesiology, and Nutrition, University of Texas at San Antonio, 1 UTSA Circle, San Antonio, TX, 78249, USA
| | - Emily A Wason
- Laboratory of Cardiovascular Research, Department of Health, Kinesiology, and Nutrition, University of Texas at San Antonio, 1 UTSA Circle, San Antonio, TX, 78249, USA
| | - Justin R Cruger
- Laboratory of Cardiovascular Research, Department of Health, Kinesiology, and Nutrition, University of Texas at San Antonio, 1 UTSA Circle, San Antonio, TX, 78249, USA
| | - Eunhee Chung
- Laboratory of Cardiovascular Research, Department of Health, Kinesiology, and Nutrition, University of Texas at San Antonio, 1 UTSA Circle, San Antonio, TX, 78249, USA
| | - John Q Zhang
- Laboratory of Cardiovascular Research, Department of Health, Kinesiology, and Nutrition, University of Texas at San Antonio, 1 UTSA Circle, San Antonio, TX, 78249, USA.
- Laboratory of Cardiovascular Research, Department of Health, Kinesiology, and Nutrition, University of Texas at San Antonio, 1 UTSA Circle, San Antonio, TX, 78240, USA.
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Characterization of Mitochondrial Content and Respiratory Capacities of Broiler Chicken Skeletal Muscles with Different Muscle Fiber Compositions. J Poult Sci 2018; 55:210-216. [PMID: 32055177 PMCID: PMC6756499 DOI: 10.2141/jpsa.0170141] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 11/27/2017] [Indexed: 12/13/2022] Open
Abstract
Mitochondrial content is regarded a useful feature to distinguish muscle-fiber types in terms of energy metabolism in skeletal muscles. Increasing evidence suggests that specific mitochondrial bioenergetic phenotypes exist in metabolically different muscle fibers. A few studies have examined the energetic properties of skeletal muscle in domestic fowls; however, no information on muscle bioenergetics in broiler chickens selectively bred for faster growth is available. In this study, we aimed to characterize the mitochondrial contents and functions of chicken skeletal muscle consisting entirely of type I (oxidative) (M. pubo-ischio-femoralis pars medialis), type IIA (glycolytic/oxidative) (M. pubo-ischio-femoralis pars lateralis), and type IIB (glycolytic) (M. pectoralis) muscle fibers. Citrate synthase (CS) activity was the highest in type IIA muscle tissues and isolated mitochondria, among the muscle tissues tested. Although no difference was registered in mitochondrial CS activity between type IIB and type I muscles, tissue CS activity was significantly higher in the latter. Histochemical staining for NADH tetrazolium reductase and the ratio of muscle-tissue to mitochondrial CS activity indicated that type I, type IIA, and type IIB muscle-fiber types showed decreasing mitochondrial content. Mitochondria from type I muscle exhibited a higher coupled respiration rate induced by pyruvate/malate, palmitoyl-CoA/malate, and palmitoyl-carnitine, as respiratory substrates, than type IIB-muscle mitochondria, while the response of mitochondria from type IIA muscle to those substrates was comparable to that of mitochondria from type I muscle. Type IIA-muscle mitochondria exhibited the highest carnitine palmitoyltransferase-2 level among all tissues tested, which may contribute to the higher fatty acid oxidation in these mitochondria. The results suggest that mitochondrial abundance is one of the features differentiating metabolic characteristics of different chicken skeletal muscle types. Moreover, the study demonstrated that type IIA-muscle mitochondria may have distinct metabolic capacities.
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Effects of Cobalt Chloride, a Hypoxia-Mimetic Agent, on Autophagy and Atrophy in Skeletal C2C12 Myotubes. BIOMED RESEARCH INTERNATIONAL 2017; 2017:7097580. [PMID: 28706950 PMCID: PMC5494548 DOI: 10.1155/2017/7097580] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 05/15/2017] [Accepted: 05/24/2017] [Indexed: 11/22/2022]
Abstract
Background Hypoxia-induced autophagy and muscle wasting occur in several environmental and pathological conditions. However, the molecular mechanisms underlying the effects of the hypoxia-mimetic agent CoCl2 on autophagy and muscle atrophy are still unclear. Methods C2C12 myotubes were exposed to increasing concentrations of CoCl2 for 24 hours. Quantitative RT-PCR, Western blotting, and transmission electron microscopy were performed to confirm autophagy occurs. Autophagy proteins were measured to understand the molecule mechanisms. We also inhibited hypoxic autophagy and examined the changes in myogenin expression, myotubes formation, and apoptosis. Results Our results showed that CoCl2-mimicked hypoxia upregulated the expression of the autophagy-related proteins LC3, HIF-1α, BNIP3, p-AMPKα, and beclin-1, whereas p62 and p-mTOR were downregulated. In addition, the autophagosome could be observed after CoCl2 induction. The expression of the autophagy-related E3 ligase parkin and the muscle-specific ubiquitin ligase atrogin-1 was increased by CoCl2. Inhibition of autophagy by 3MA increased myogenin expression and promoted myotubes formation and the percentage of cell death was decreased. Conclusions Our results confirmed that CoCl2-mimicked hypoxia induced autophagy via the HIF-1α/BNIP3/beclin-1 and AMPK/mTOR pathways. Our results also revealed an important link between autophagy and muscle atrophy under hypoxia, which may help to develop new therapeutic strategies for muscle diseases.
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