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Lundsgaard AM, Fritzen AM, Kiens B. Molecular Regulation of Fatty Acid Oxidation in Skeletal Muscle during Aerobic Exercise. Trends Endocrinol Metab 2018; 29:18-30. [PMID: 29221849 DOI: 10.1016/j.tem.2017.10.011] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 10/28/2017] [Accepted: 10/30/2017] [Indexed: 01/21/2023]
Abstract
This review summarizes how fatty acid (FA) oxidation is regulated in skeletal muscle during exercise. From the available evidence it seems that acetyl-CoA availability in the mitochondrial matrix adjusts FA oxidation to exercise intensity and duration. This is executed at the step of mitochondrial fatty acyl import, as the extent of acetyl group sequestration by carnitine determines the availability of carnitine for the carnitine palmitoyltransferase 1 (CPT1) reaction. The rate of glycolysis seems therefore to be central to the amount of β-oxidation-derived acetyl-CoA that is oxidized in the tricarboxylic acid (TCA) cycle. FA oxidation during exercise is also determined by FA availability to mitochondria, dependent on trans-sarcolemmal FA uptake via cluster of differentiation 36/SR-B2 (CD36) and FAs mobilized from myocellular lipid droplets.
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Affiliation(s)
- Anne-Marie Lundsgaard
- Section of Molecular Physiology, Department of Nutrition, Exercise, and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Andreas Mæchel Fritzen
- Section of Molecular Physiology, Department of Nutrition, Exercise, and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Bente Kiens
- Section of Molecular Physiology, Department of Nutrition, Exercise, and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.
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mTOR Signaling Pathway and Protein Synthesis: From Training to Aging and Muscle Autophagy. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1088:139-151. [PMID: 30390251 DOI: 10.1007/978-981-13-1435-3_7] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In muscle tissue there is a balance between the processes muscle synthesis and degradation. The mammalian target of rapamycin (mTOR) signaling pathway plays a critical role in regulating protein synthesis in order to maintain muscular protein turnover and trophism. Studies have shown that both down- and upregulation mechanisms are involved in this process in a manner dependent on stimulus and cellular conditions. Additionally, mTOR signaling has recently been implicated in several physiological conditions related to cell survival, such as self-digestion (autophagy), energy production, and the preservation of cellular metabolic balance over the lifespan. Here we briefly describe the mTOR structure and its regulatory protein synthesis pathway. Furthermore, the role of mTOR protein in autophagy, aging, and mitochondrial function in muscle tissue is presented.
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Lundsgaard AM, Sjøberg KA, Høeg LD, Jeppesen J, Jordy AB, Serup AK, Fritzen AM, Pilegaard H, Myrmel LS, Madsen L, Wojtaszewski JFP, Richter EA, Kiens B. Opposite Regulation of Insulin Sensitivity by Dietary Lipid Versus Carbohydrate Excess. Diabetes 2017; 66:2583-2595. [PMID: 28768703 DOI: 10.2337/db17-0046] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 07/27/2017] [Indexed: 11/13/2022]
Abstract
To understand the mechanisms in lipid-induced insulin resistance, a more physiological approach is to enhance fatty acid (FA) availability through the diet. Nine healthy men ingested two hypercaloric diets (in 75% excess of habitual caloric intake) for 3 days, enriched in unsaturated FA (78 energy % [E%] fat) (UNSAT) or carbohydrates (80 E% carbohydrate) (CHO) as well as a eucaloric control diet (CON). Compared with CON, the UNSAT diet reduced whole-body and leg glucose disposal during a hyperinsulinemic-euglycemic clamp, while decreasing hepatic glucose production. In muscle, diacylglycerol (DAG) and intramyocellular triacylglycerol were increased. The accumulated DAG was sn-1,3 DAG, which is known not to activate PKC, and insulin signaling was intact. UNSAT decreased PDH-E1α protein content and increased inhibitory PDH-E1α Ser300 phosphorylation and FA oxidation. CHO increased whole-body and leg insulin sensitivity, while increasing hepatic glucose production. After CHO, muscle PDH-E1α Ser300 phosphorylation was decreased, and glucose oxidation increased. After UNSAT, but not CHO, muscle glucose-6-phosphate content was 103% higher compared with CON during the clamp. Thus, PDH-E1α expression and covalent regulation, and hence the tricarboxylic acid cycle influx of pyruvate-derived acetyl-CoA relative to β-oxidation-derived acetyl-CoA, are suggested to impact on insulin-stimulated glucose uptake. Taken together, the oxidative metabolic fluxes of glucose and FA are powerful and opposite regulators of insulin action in muscle.
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Affiliation(s)
- Anne-Marie Lundsgaard
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Kim A Sjøberg
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Louise D Høeg
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Jacob Jeppesen
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Andreas B Jordy
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Annette K Serup
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Andreas M Fritzen
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | | | - Lene S Myrmel
- National Institute of Nutrition and Seafood Research, Bergen, Norway
| | - Lise Madsen
- National Institute of Nutrition and Seafood Research, Bergen, Norway
- Laboratory of Genomics and Molecular Biomedicine, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Jørgen F P Wojtaszewski
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Erik A Richter
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Bente Kiens
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
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Abstract
PURPOSE OF REVIEW A compromised autophagy is associated with the onset of obesity, type 2 diabetes, nonalcoholic fatty liver disease, cardiovascular and neurodegenerative diseases. Our aim is to review the potential role of ghrelin, a gut hormone involved in energy homeostasis, in the regulation of autophagy. RECENT FINDINGS In the recent years, it has been demonstrated that autophagy constitutes an important mechanism by which ghrelin exerts a plethora of central and peripheral actions. Ghrelin enhances autophagy through the activation of AMP-activated protein kinase in different target organs to regulate lipid and glucose metabolism, the remodeling and protection of small intestine mucosa, protection against cardiac ischemia as well as higher brain functions such as learning and memory consolidation. Nonetheless, in inflammatory states, such as acute hepatitis, liver fibrosis or adipose tissue inflammation, ghrelin acts as an anti-inflammatory factor reducing the autophagic flux to prevent further cell injury. Interestingly, several cardiometabolic disorders, including obesity, type 2 diabetes, nonalcoholic fatty liver disease or chronic heart failure are accompanied by low ghrelin levels in addition to altered autophagy. SUMMARY Ghrelin represents an attractive target for development of therapeutics for prevention or treatment of metabolic, cardiac or neuronal disorders, in which autophagy is impaired.
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Affiliation(s)
- Silvia Ezquerro
- aMetabolic Research Laboratory, Clínica Universidad de Navarra, Pamplona bCIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid cDepartment of Endocrinology & Nutrition, Clínica Universidad de Navarra, Pamplona, Spain
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Martin-Rincon M, Morales-Alamo D, Calbet JAL. Exercise-mediated modulation of autophagy in skeletal muscle. Scand J Med Sci Sports 2017; 28:772-781. [PMID: 28685860 DOI: 10.1111/sms.12945] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/01/2017] [Indexed: 12/13/2022]
Abstract
Although exercise exerts multiple beneficial health effects, it may also damage cellular structures. Damaged elements are continuously degraded and its constituents recycled to produce renovated structures through a process called autophagy, which is essential for the adaptation to training. Autophagy is particularly active in skeletal muscle, where it can be evaluated using specific molecular markers of activation (unc-51-like kinase 1 [ULK1] phosphorylation) and specific proteins indicating increased autophagosome content (increased total LC3, LC3-II, LC3-II/LC3-I ratio). Studies in humans are technically limited but have provided evidence suggesting the activation of autophagy in skeletal muscle through AMP-activated protein kinase (AMPK) and its downstream target ULK1. Autophagy activation is more likely when the intensity is elevated and the exercise performed in the fasted state. The autophagy-gene program and autophagosome content are upregulated after ultraendurance running competitions. However, autophagosome content is reduced after endurance exercise at moderate intensities (50% and 70% of VO2 max) for 60-120 minutes. Autophagosome content is decreased within the first few hours after resistance training. The effects of regular endurance and strength training on basal autophagy remain to be established in humans. One study has reported that acute severe hypoxia increases autophagosome content in human skeletal muscle, which is reverted by 20 minutes of low-intensity exercise. Experiments with transgenic mice have shown that autophagy is necessary for skeletal muscle adaptation to training. Little is known on how genetic factors, environment, nutrition, drugs and diseases may interact with exercise to modulate autophagy at rest and during exercise in humans.
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Affiliation(s)
- M Martin-Rincon
- Research Institute of Biomedical and Health Sciences (IUIBS), Las Palmas de Gran Canaria, Canary Islands, Spain.,Department of Physical Education, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - D Morales-Alamo
- Research Institute of Biomedical and Health Sciences (IUIBS), Las Palmas de Gran Canaria, Canary Islands, Spain.,Department of Physical Education, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - J A L Calbet
- Research Institute of Biomedical and Health Sciences (IUIBS), Las Palmas de Gran Canaria, Canary Islands, Spain.,Department of Physical Education, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
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Halling JF, Pilegaard H. Autophagy-Dependent Beneficial Effects of Exercise. Cold Spring Harb Perspect Med 2017; 7:cshperspect.a029777. [PMID: 28270532 DOI: 10.1101/cshperspect.a029777] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Exercise has long been recognized as a powerful physiological stimulus for a wide variety of metabolic adaptations with implications for health and performance. The metabolic effects of exercise occur during and after each exercise bout and manifest as cumulative adaptive responses to successive exercise bouts. Studies on the beneficial effects of exercise have traditionally focused on the biosynthesis of metabolic proteins and organelles. However, the recycling of cellular components by autophagy has recently emerged as an important process involved in the adaptive responses to exercise. This review covers the regulation of autophagy by exercise, with emphasis on the potential autophagy-dependent beneficial effects of exercise.
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Affiliation(s)
- Jens Frey Halling
- Department of Biology, University of Copenhagen, 2100 Copenhagen, Denmark
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Kim Y, Hood DA. Regulation of the autophagy system during chronic contractile activity-induced muscle adaptations. Physiol Rep 2017; 5:e13307. [PMID: 28720712 PMCID: PMC5532476 DOI: 10.14814/phy2.13307] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 05/10/2017] [Accepted: 05/10/2017] [Indexed: 11/24/2022] Open
Abstract
Skeletal muscle is adaptable to exercise stimuli via the upregulation of mitochondrial biogenesis, and recent studies have suggested that autophagy also plays a role in exercise-induced muscle adaptations. However, it is still obscure how muscle regulates autophagy over the time course of training adaptations. This study examined the expression of autophagic proteins in skeletal muscle of rats exposed to chronic contractile activity (CCA; 6 h/day, 9V, 10 Hz continuous, 0.1 msec pulse duration) for 1, 3, and 7 days (n = 8/group). CCA-induced mitochondrial adaptations were observed by day 7, as shown by the increase in mitochondrial proteins (PGC-1α, COX I, and COX IV), as well as COX activity. Notably, the ratio of LC3 II/LC3 I, an indicator of autophagy, decreased by day 7 largely due to a significant increase in LC3 I. The autophagic induction marker p62 was elevated on day 3 and returned to basal levels by day 7, suggesting a time-dependent increase in autophagic flux. The lysosomal system was upregulated early, prior to changes in mitochondrial proteins, as represented by increases in lysosomal system markers LAMP1, LAMP2A, and MCOLN1 as early as by day 1, as well as TFEB, a primary regulator of lysosomal biogenesis and autophagy flux. Our findings suggest that, in response to chronic exercise, autophagy is upregulated concomitant with mitochondrial adaptations. Notably, our data reveal the surprising adaptive plasticity of the lysosome in response to chronic contractile activity which enhances muscle health by providing cells with a greater capacity for macromolecular and organelle turnover.
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Affiliation(s)
- Yuho Kim
- Muscle Health Research Centre, School of Kinesiology and Health Science York University, Toronto, Ontario, Canada
- School of Kinesiology and Health Science York University, Toronto, Ontario, Canada
| | - David A Hood
- Muscle Health Research Centre, School of Kinesiology and Health Science York University, Toronto, Ontario, Canada
- School of Kinesiology and Health Science York University, Toronto, Ontario, Canada
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Rocchi A, He C. Regulation of Exercise-Induced Autophagy in Skeletal Muscle. CURRENT PATHOBIOLOGY REPORTS 2017; 5:177-186. [PMID: 29057166 PMCID: PMC5646231 DOI: 10.1007/s40139-017-0135-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
PURPOSE OF REVIEW Physical exercise is a highly effective method to prevent several pathogenic conditions, such as obesity, type 2 diabetes and cardiovascular diseases, largely due to metabolic adaptations induced by exercise in skeletal muscle. Yet how exercise induces the beneficial effects in muscle remains to be fully elucidated. Autophagy is a lysosomal degradation pathway that regulates nutrient recycling, energy production and organelle quality control. The autophagy pathway is upregulated in response to stress during exercise and muscle contraction, and may be an important mechanism mediating exercise-induced health benefits. RECENT FINDINGS A number of studies have indicated that physical exercise induces non-selective autophagy and selective mitophagy in skeletal muscle in animal models and humans. The AMPK-ULK1 and the FoxO3 signaling pathways play an essential role in the activation of the upstream autophagy machinery in skeletal muscle during exercise. The autophagy activity is required for health benefits of exercise, as in different autophagy-deficient mouse lines exercise-induced effects are abolished. SUMMARY This review aims to summarize and highlight the most recent findings on the role of autophagy in muscle maintenance, the molecular pathways that upregulate autophagy during exercise, and the potential functions of exercise-induced autophagy and mitophagy in skeletal muscle.
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Affiliation(s)
- Altea Rocchi
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Congcong He
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
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Qian Z, Ren L, Wu D, Yang X, Zhou Z, Nie Q, Jiang G, Xue S, Weng W, Qiu Y, Lin Y. Overexpression of FoxO3a is associated with glioblastoma progression and predicts poor patient prognosis. Int J Cancer 2017; 140:2792-2804. [PMID: 28295288 DOI: 10.1002/ijc.30690] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 02/09/2017] [Accepted: 03/01/2017] [Indexed: 12/28/2022]
Abstract
Forkhead transcription factor FoxO3a has been reported to have ambiguous functions and distinct mechanisms in various solid tumors, including glioblastoma (GBM). Although a preliminary analysis of a small sample of patients indicated that FoxO3a aberrations in glioma might be related to aggressive clinical behavior, the clinical significance of FoxO3a in glioblastoma remains unclear. We investigated the expression of FoxO3a in a cohort of 91 glioblastoma specimens and analyzed the correlations of protein expression with patient prognosis. Furthermore, the functional impact of FoxO3a on GBM progression and the underlying mechanisms of FoxO3a regulation were explored in a series of in vitro and in vivo assays. FoxO3a expression was elevated in glioblastoma tissues, and high nuclear FoxO3a expression in human GBM tissues was associated with poor prognosis. Moreover, knockdown of FoxO3a significantly reduced the colony formation and invasion ability of GBM cells, whereas overexpression of FoxO3a promoted the colony formation and invasion ability. The results of in vivo GBM models further confirmed that FoxO3a knockdown inhibited GBM progression. More, the pro-oncogenic effects of FoxO3a in GBM were mediated by the activation of c-Myc, microtubule-associated protein 1 light chain 3 beta (LC3B) and Beclin1 in a mixed-lineage leukemia 2 (MLL2)-dependent manner. These findings suggest that high FoxO3a expression is associated with glioblastoma progression and that FoxO3a independently indicates poor prognosis in patients. FoxO3a might be a novel prognostic biomarker or a potential therapeutic target in glioblastoma.
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Affiliation(s)
- Zhongrun Qian
- Department of Neurosurgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Li Ren
- Department of Neurosurgery, Shanghai Pudong Hospital, Fudan University, Shanghai, China
| | - Dingchang Wu
- Department of Clinical Laboratory, Longyan First Hospital, Fujian Medical University, Longyan, China
| | - Xi Yang
- Department of Neurosurgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Zhiyi Zhou
- Department of Neurosurgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Quanmin Nie
- Department of Neurosurgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Gan Jiang
- Department of Pharmacology, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Shuanglin Xue
- Department of Neurosurgery, Longyan First Hospital, Fujian Medical University, Longyan, China
| | - Weiji Weng
- Department of Neurosurgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yongming Qiu
- Department of Neurosurgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yingying Lin
- Department of Neurosurgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
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Padrão AI, Figueira ACC, Faustino-Rocha AI, Gama A, Loureiro MM, Neuparth MJ, Moreira-Gonçalves D, Vitorino R, Amado F, Santos LL, Oliveira PA, Duarte JA, Ferreira R. Long-term exercise training prevents mammary tumorigenesis-induced muscle wasting in rats through the regulation of TWEAK signalling. Acta Physiol (Oxf) 2017; 219:803-813. [PMID: 27228549 DOI: 10.1111/apha.12721] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Revised: 01/27/2016] [Accepted: 05/24/2016] [Indexed: 12/27/2022]
Abstract
AIM Exercise training has been suggested as a non-pharmacological approach to prevent skeletal muscle wasting and improve muscle function in cancer cachexia. However, little is known about the molecular mechanisms underlying such beneficial effect. In this study, we aimed to, firstly, examine the contribution of TWEAK signalling to cancer-induced skeletal muscle wasting and, secondly, evaluate whether long-term exercise alters TWEAK signalling and prevents muscle wasting. METHODS Female Sprague-Dawley rats were randomly assigned to control and exercise groups. Fifteen animals from each group were exposed to N-Methyl-N-nitrosourea carcinogen. Animals in exercise groups were submitted to moderate treadmill exercise for 35 weeks. After the experimental period, animals were killed and gastrocnemius muscles were harvested for morphological and biochemical analysis. RESULTS We verified that exercise training prevented tumour-induced TWEAK/NF-κB signalling in skeletal muscle with a beneficial impact in fibre cross-sectional area and metabolism. Indeed, 35 weeks of exercise training promoted the upregulation of PGC-1α and oxidative phosphorylation complexes. This exercise-induced muscle remodelling in tumour-bearing animals was associated with less malignant mammary lesions. CONCLUSION Data support the benefits of an active lifestyle for the prevention of muscle wasting secondary to breast cancer, highlighting TWEAK/NF- κB signalling as a potential therapeutic target for the preservation of muscle mass.
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Affiliation(s)
- A. I. Padrão
- QOPNA; Department of Chemistry; University of Aveiro; Aveiro Portugal
- CIAFEL; Faculty of Sport; University of Porto; Porto Portugal
| | | | - A. I. Faustino-Rocha
- CITAB; Department of Veterinary Sciences; University of Trás-os-Montes e Alto Douro; Vila Real Portugal
| | - A. Gama
- CITAB; Department of Veterinary Sciences; University of Trás-os-Montes e Alto Douro; Vila Real Portugal
| | - M. M. Loureiro
- QOPNA; Department of Chemistry; University of Aveiro; Aveiro Portugal
| | - M. J. Neuparth
- CIAFEL; Faculty of Sport; University of Porto; Porto Portugal
| | - D. Moreira-Gonçalves
- CIAFEL; Faculty of Sport; University of Porto; Porto Portugal
- Department of Physiology and Cardiothoracic Surgery; Faculty of Medicine; University of Porto; Porto Portugal
| | - R. Vitorino
- QOPNA; Department of Chemistry; University of Aveiro; Aveiro Portugal
- Department of Medical Sciences and Institute for Biomedicine - iBiMED; University of Aveiro; Aveiro Portugal
| | - F. Amado
- QOPNA; Department of Chemistry; University of Aveiro; Aveiro Portugal
| | - L. L. Santos
- Experimental Pathology and Therapeutics Group; Portuguese Institute of Oncology; Porto Portugal
| | - P. A. Oliveira
- CITAB; Department of Veterinary Sciences; University of Trás-os-Montes e Alto Douro; Vila Real Portugal
| | - J. A. Duarte
- CIAFEL; Faculty of Sport; University of Porto; Porto Portugal
| | - R. Ferreira
- QOPNA; Department of Chemistry; University of Aveiro; Aveiro Portugal
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Mice endometrium receptivity in early pregnancy is impaired by maternal hyperinsulinemia. Mol Med Rep 2017; 15:2503-2510. [PMID: 28447735 PMCID: PMC5428841 DOI: 10.3892/mmr.2017.6322] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 02/07/2017] [Indexed: 12/20/2022] Open
Abstract
Previous studies have investigated the lower embryo implantation rates in women with polycystic ovary syndrome, obesity and type 2 diabetes, and specifically the association between the abnormal oocyte and embryo and hyperinsulinemia. The importance of hyperinsulinemia on maternal endometrium receptivity remains to be elucidated. The present study used a hyperinsulinemic mouse model to determine whether hyperinsulinemia may affect endometrial receptivity. An insulin intervention mouse model was first established. The serum levels of insulin, progesterone and estradiol were subsequently detected by ELISA assay analysis. The number of implantation sites was recorded using Trypan blue dye and the morphology of mice uteri was investigated using hematoxylin and eosin staining. The expression levels of molecular markers associated with endometrial receptivity were detected by reverse transcription‑quantitative polymerase chain reaction, western blotting and immunohistochemistry analyses. Finally, the importance of mechanistic target of rapamycin (mTOR) expression following insulin treatment was determined. Mice treated with insulin developed insulin resistance and hyperinsulinemia. The number of implantation sites following insulin treatment did not differ between the control and insulin‑treated groups. Additionally, no significant morphological alterations in mice uteri between control and insulin‑treated groups were observed. However, the expression levels of estrogen receptor (Esr) 1, Esr2, progesterone receptor and homeobox A10 associated with endometrial receptivity, were imbalanced during endometrium receptivity when maternal hyperinsulinemia was induced. Western blot analysis revealed that expression levels of endometrial phosphorylated (p)‑mTOR and p‑ribosomal protein S6 kinase β‑1 were significantly greater in the insulin‑treated group. These results demonstrated that although an embryo may implant into endometrium, mice endometrium receptivity in early pregnancy may be impaired by maternal hyperinsulinemia. In addition, mTOR signaling may be involved in this process. The present study provides preliminary results demonstrating that female reproduction may be compromised during hyperinsulinemia, which requires further investigation in future studies.
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High intensity aerobic exercise training improves chronic intermittent hypoxia-induced insulin resistance without basal autophagy modulation. Sci Rep 2017; 7:43663. [PMID: 28255159 PMCID: PMC5334652 DOI: 10.1038/srep43663] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 01/25/2017] [Indexed: 12/11/2022] Open
Abstract
Chronic intermittent hypoxia (IH) associated with obstructive sleep apnea (OSA) is a major risk factor for cardiovascular and metabolic diseases (insulin resistance: IR). Autophagy is involved in the pathophysiology of IR and high intensity training (HIT) has recently emerged as a potential therapy. We aimed to confirm IH-induced IR in a tissue-dependent way and to explore the preventive effect of HIT on IR-induced by IH. Thirty Swiss 129 male mice were randomly assigned to Normoxia (N), Intermittent Hypoxia (IH: 21-5% FiO2, 30 s cycle, 8 h/day) or IH associated with high intensity training (IH HIT). After 8 days of HIT (2*24 min, 50 to 90% of Maximal Aerobic Speed or MAS on a treadmill) mice underwent 14 days IH or N. We found that IH induced IR, characterized by a greater glycemia, an impaired insulin sensitivity and lower AKT phosphorylation in adipose tissue and liver. Nevertheless, MAS and AKT phosphorylation were greater in muscle after IH. IH associated with HIT induced better systemic insulin sensitivity and AKT phosphorylation in liver. Autophagy markers were not altered in both conditions. These findings suggest that HIT could represent a preventive strategy to limit IH-induced IR without change of basal autophagy.
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63
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Acute low-intensity cycling with blood-flow restriction has no effect on metabolic signaling in human skeletal muscle compared to traditional exercise. Eur J Appl Physiol 2017; 117:345-358. [DOI: 10.1007/s00421-016-3530-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Accepted: 12/29/2016] [Indexed: 10/20/2022]
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64
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Ren YY, Koch LG, Britton SL, Qi NR, Treutelaar MK, Burant CF, Li JZ. Selection-, age-, and exercise-dependence of skeletal muscle gene expression patterns in a rat model of metabolic fitness. Physiol Genomics 2016; 48:816-825. [PMID: 27637250 DOI: 10.1152/physiolgenomics.00118.2015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 09/09/2016] [Indexed: 11/22/2022] Open
Abstract
Intrinsic aerobic exercise capacity can influence many complex traits including obesity and aging. To study this connection we established two rat lines by divergent selection of untrained aerobic capacity. After 32 generations the high capacity runners (HCR) and low capacity runners (LCR) differed in endurance running distance and body fat, blood glucose, other health indicators, and natural life span. To understand the interplay among genetic differences, chronological age, and acute exercise we performed microarray-based gene expression analyses in skeletal muscle with a 2×2×2 design to simultaneously compare HCR and LCR, old and young animals, and rest and exhaustion. Transcripts for mitochondrial function are expressed higher in HCRs than LCRs at both rest and exhaustion and for both age groups. Expression of cell adhesion and extracellular matrix genes tend to decrease with age. This and other age effects are more prominent in LCRs than HCRs, suggesting that HCRs have a slower aging process and this may be partly due to their better metabolic health. Strenuous exercise mainly affects transcription regulation and cellular response. The effects of any one factor often depend on the other two. For example, there are ∼140 and ∼110 line-exercise "interacting" genes for old and young animals, respectively. Many genes highlighted in our study are consistent with prior reports, but many others are novel. The gene- and pathway-level statistics for the main effects, either overall or stratified, and for all possible interactions, represent a rich reference dataset for understanding the interdependence among lines, aging, and exercise.
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Affiliation(s)
- Yu-Yu Ren
- Department of Human Genetics, University of Michigan, Ann Arbor, Michigan
| | - Lauren G Koch
- Department of Anesthesiology, University of Michigan, Ann Arbor, Michigan; and
| | - Steven L Britton
- Department of Anesthesiology, University of Michigan, Ann Arbor, Michigan; and
| | - Nathan R Qi
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - Mary K Treutelaar
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - Charles F Burant
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - Jun Z Li
- Department of Human Genetics, University of Michigan, Ann Arbor, Michigan;
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Dickinson JM, Reidy PT, Gundermann DM, Borack MS, Walker DK, D'Lugos AC, Volpi E, Rasmussen BB. The impact of postexercise essential amino acid ingestion on the ubiquitin proteasome and autophagosomal-lysosomal systems in skeletal muscle of older men. J Appl Physiol (1985) 2016; 122:620-630. [PMID: 27586837 PMCID: PMC5401961 DOI: 10.1152/japplphysiol.00632.2016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 08/30/2016] [Accepted: 08/31/2016] [Indexed: 12/11/2022] Open
Abstract
Essential amino acid (EAA) ingestion enhances postexercise muscle protein synthesis, and, in particular, the anabolic response of older adults appears sensitive to the quantity of ingested leucine. The effect of leucine ingestion on muscle breakdown following resistance exercise (RE) is less understood. The purpose of this study was to identify the impact of postexercise leucine ingestion on the ubiquitin proteasome and autophagosomal-lysosomal systems following acute RE in older men. Subjects (72 ± 2 yr) performed RE and 1 h postexercise ingested 10 g of EAA containing a leucine quantity similar to quality protein (control, 1.8 g leucine, n = 7) or enriched in leucine (leucine, 3.5 g leucine, n = 8). Stable isotope infusion and muscle biopsies (vastus lateralis) obtained at rest and 2, 5, and 24 h postexercise were used to examine protein content (Western blot), mRNA expression (RT-quantitative PCR), and muscle protein fractional breakdown rate (FBR). Muscle-specific RING finger 1 mRNA increased in both groups at 2 and 5 h (P < 0.05). LC3 mRNA increased, and the LC3BII-to-LC3BI ratio decreased at all postexercise time points in control (P < 0.05). Conversely, LC3 mRNA only increased at 2 h, and the LC3BII-to-LC3BI ratio only decreased at 2 and 5 h in leucine (P < 0.05). Tumor necrosis factor receptor-associated factor-6 mRNA increased (P < 0.05) in control at 5 h. FBR was not statistically different between groups or from basal 24 h postexercise (P > 0.05). These data indicate that ingesting a larger quantity of leucine following RE may further reduce postexercise skeletal muscle autophagy in older men; however, it does not appear to influence the acute postexercise elevation in markers of the ubiquitin proteasome system or the breakdown of intact proteins.NEW & NOTEWORTHY The impact of postexercise leucine ingestion on processes of skeletal muscle breakdown in older adults is not well understood. Additional postexercise leucine ingestion appears to further reduce autophagy, but it does not interfere with the increase in ubiquitin proteasome system markers or the breakdown of intact proteins in skeletal muscle of older men. Postexercise leucine ingestion may promote a healthier protein pool and favorable muscle adaptations in older adults through greater accretion of myofibrillar proteins.
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Affiliation(s)
- Jared M Dickinson
- School of Nutrition and Health Promotion, Healthy Lifestyles Research Center, Exercise Science and Health Promotion, Arizona State University, Phoenix, Arizona; .,Department of Nutrition and Metabolism, University of Texas Medical Branch, Galveston, Texas.,Sealy Center on Aging, University of Texas Medical Branch, Galveston, Texas.,Division of Rehabilitation Sciences, University of Texas Medical Branch, Galveston, Texas; and
| | - Paul T Reidy
- Department of Nutrition and Metabolism, University of Texas Medical Branch, Galveston, Texas.,Division of Rehabilitation Sciences, University of Texas Medical Branch, Galveston, Texas; and
| | - David M Gundermann
- Department of Nutrition and Metabolism, University of Texas Medical Branch, Galveston, Texas.,Division of Rehabilitation Sciences, University of Texas Medical Branch, Galveston, Texas; and
| | - Michael S Borack
- Department of Nutrition and Metabolism, University of Texas Medical Branch, Galveston, Texas.,Division of Rehabilitation Sciences, University of Texas Medical Branch, Galveston, Texas; and
| | - Dillon K Walker
- Department of Nutrition and Metabolism, University of Texas Medical Branch, Galveston, Texas
| | - Andrew C D'Lugos
- School of Nutrition and Health Promotion, Healthy Lifestyles Research Center, Exercise Science and Health Promotion, Arizona State University, Phoenix, Arizona
| | - Elena Volpi
- Department of Nutrition and Metabolism, University of Texas Medical Branch, Galveston, Texas.,Sealy Center on Aging, University of Texas Medical Branch, Galveston, Texas.,Division of Rehabilitation Sciences, University of Texas Medical Branch, Galveston, Texas; and.,Department of Internal Medicine-Geriatrics, University of Texas Medical Branch, Galveston, Texas
| | - Blake B Rasmussen
- Department of Nutrition and Metabolism, University of Texas Medical Branch, Galveston, Texas.,Sealy Center on Aging, University of Texas Medical Branch, Galveston, Texas.,Division of Rehabilitation Sciences, University of Texas Medical Branch, Galveston, Texas; and
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Unravelling the mechanisms regulating muscle mitochondrial biogenesis. Biochem J 2016; 473:2295-314. [DOI: 10.1042/bcj20160009] [Citation(s) in RCA: 350] [Impact Index Per Article: 43.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 04/18/2016] [Indexed: 11/17/2022]
Abstract
Skeletal muscle is a tissue with a low mitochondrial content under basal conditions, but it is responsive to acute increases in contractile activity patterns (i.e. exercise) which initiate the signalling of a compensatory response, leading to the biogenesis of mitochondria and improved organelle function. Exercise also promotes the degradation of poorly functioning mitochondria (i.e. mitophagy), thereby accelerating mitochondrial turnover, and preserving a pool of healthy organelles. In contrast, muscle disuse, as well as the aging process, are associated with reduced mitochondrial quality and quantity in muscle. This has strong negative implications for whole-body metabolic health and the preservation of muscle mass. A number of traditional, as well as novel regulatory pathways exist in muscle that control both biogenesis and mitophagy. Interestingly, although the ablation of single regulatory transcription factors within these pathways often leads to a reduction in the basal mitochondrial content of muscle, this can invariably be overcome with exercise, signifying that exercise activates a multitude of pathways which can respond to restore mitochondrial health. This knowledge, along with growing realization that pharmacological agents can also promote mitochondrial health independently of exercise, leads to an optimistic outlook in which the maintenance of mitochondrial and whole-body metabolic health can be achieved by taking advantage of the broad benefits of exercise, along with the potential specificity of drug action.
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