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White MR, Yates DT. Dousing the flame: reviewing the mechanisms of inflammatory programming during stress-induced intrauterine growth restriction and the potential for ω-3 polyunsaturated fatty acid intervention. Front Physiol 2023; 14:1250134. [PMID: 37727657 PMCID: PMC10505810 DOI: 10.3389/fphys.2023.1250134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 08/14/2023] [Indexed: 09/21/2023] Open
Abstract
Intrauterine growth restriction (IUGR) arises when maternal stressors coincide with peak placental development, leading to placental insufficiency. When the expanding nutrient demands of the growing fetus subsequently exceed the capacity of the stunted placenta, fetal hypoxemia and hypoglycemia result. Poor fetal nutrient status stimulates greater release of inflammatory cytokines and catecholamines, which in turn lead to thrifty growth and metabolic programming that benefits fetal survival but is maladaptive after birth. Specifically, some IUGR fetal tissues develop enriched expression of inflammatory cytokine receptors and other signaling cascade components, which increases inflammatory sensitivity even when circulating inflammatory cytokines are no longer elevated after birth. Recent evidence indicates that greater inflammatory tone contributes to deficits in skeletal muscle growth and metabolism that are characteristic of IUGR offspring. These deficits underlie the metabolic dysfunction that markedly increases risk for metabolic diseases in IUGR-born individuals. The same programming mechanisms yield reduced metabolic efficiency, poor body composition, and inferior carcass quality in IUGR-born livestock. The ω-3 polyunsaturated fatty acids (PUFA) are diet-derived nutraceuticals with anti-inflammatory effects that have been used to improve conditions of chronic systemic inflammation, including intrauterine stress. In this review, we highlight the role of sustained systemic inflammation in the development of IUGR pathologies. We then discuss the potential for ω-3 PUFA supplementation to improve inflammation-mediated growth and metabolic deficits in IUGR offspring, along with potential barriers that must be considered when developing a supplementation strategy.
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Affiliation(s)
| | - Dustin T. Yates
- Stress Physiology Laboratory, Department of Animal Science, University of Nebraska-Lincoln, Lincoln, NE, United States
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Villar-Fincheira P, Sanhueza-Olivares F, Norambuena-Soto I, Cancino-Arenas N, Hernandez-Vargas F, Troncoso R, Gabrielli L, Chiong M. Role of Interleukin-6 in Vascular Health and Disease. Front Mol Biosci 2021; 8:641734. [PMID: 33786327 PMCID: PMC8004548 DOI: 10.3389/fmolb.2021.641734] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 02/01/2021] [Indexed: 01/08/2023] Open
Abstract
IL-6 is usually described as a pleiotropic cytokine produced in response to tissue injury or infection. As a pro-inflammatory cytokine, IL-6 activates innate and adaptative immune responses. IL-6 is released in the innate immune response by leukocytes as well as stromal cells upon pattern recognition receptor activation. IL-6 then recruits immune cells and triggers B and T cell response. Dysregulated IL-6 activity is associated with pathologies involving chronic inflammation and autoimmunity, including atherosclerosis. However, IL-6 is also produced and released under beneficial conditions, such as exercise, where IL-6 is associated with the anti-inflammatory and metabolic effects coupled with physical adaptation to intense training. Exercise-associated IL-6 acts on adipose tissue to induce lipogenesis and on arteries to induce adaptative vascular remodeling. These divergent actions could be explained by complex signaling networks. Classical IL-6 signaling involves a membrane-bound IL-6 receptor and glycoprotein 130 (gp130), while trans-signaling relies on a soluble version of IL-6R (sIL-6R) and membrane-bound gp130. Trans-signaling, but not the classical pathway, is regulated by soluble gp130. In this review, we discuss the similarities and differences in IL-6 cytokine and myokine signaling to explain the differential and opposite effects of this protein during inflammation and exercise, with a special focus on the vascular system.
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Affiliation(s)
- Paulina Villar-Fincheira
- Advanced Center for Chronic Diseases & CEMC, Faculty of Chemical and Pharmaceutical Sciences, Universidad de Chile, Santiago, Chile
| | - Fernanda Sanhueza-Olivares
- Advanced Center for Chronic Diseases & CEMC, Faculty of Chemical and Pharmaceutical Sciences, Universidad de Chile, Santiago, Chile
| | - Ignacio Norambuena-Soto
- Advanced Center for Chronic Diseases & CEMC, Faculty of Chemical and Pharmaceutical Sciences, Universidad de Chile, Santiago, Chile
| | - Nicole Cancino-Arenas
- Advanced Center for Chronic Diseases & CEMC, Faculty of Chemical and Pharmaceutical Sciences, Universidad de Chile, Santiago, Chile
| | - Felipe Hernandez-Vargas
- Advanced Center for Chronic Diseases & CEMC, Faculty of Chemical and Pharmaceutical Sciences, Universidad de Chile, Santiago, Chile
| | - Rodrigo Troncoso
- Laboratorio de Investigación en Nutrición y Actividad Física (LABINAF), Instituto de Nutrición y Tecnología de los Alimentos, Universidad de Chile, Santiago, Chile
| | - Luigi Gabrielli
- Advanced Center for Chronic Diseases, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
- *Correspondence: Luigi Gabrielli, ; Mario Chiong,
| | - Mario Chiong
- Advanced Center for Chronic Diseases & CEMC, Faculty of Chemical and Pharmaceutical Sciences, Universidad de Chile, Santiago, Chile
- *Correspondence: Luigi Gabrielli, ; Mario Chiong,
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One week of magnesium supplementation lowers IL-6, muscle soreness and increases post-exercise blood glucose in response to downhill running. Eur J Appl Physiol 2019; 119:2617-2627. [DOI: 10.1007/s00421-019-04238-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 09/28/2019] [Indexed: 12/16/2022]
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CULLEN TOM, THOMAS ANDREWW, WEBB RICHARD, PHILLIPS THOM, HUGHES MICHAELG. sIL-6R Is Related to Weekly Training Mileage and Psychological Well-being in Athletes. Med Sci Sports Exerc 2017; 49:1176-1183. [DOI: 10.1249/mss.0000000000001210] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Cadaret CN, Beede KA, Riley HE, Yates DT. Acute exposure of primary rat soleus muscle to zilpaterol HCl (β2 adrenergic agonist), TNFα, or IL-6 in culture increases glucose oxidation rates independent of the impact on insulin signaling or glucose uptake. Cytokine 2017; 96:107-113. [PMID: 28390265 DOI: 10.1016/j.cyto.2017.03.014] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 02/15/2017] [Accepted: 03/31/2017] [Indexed: 10/19/2022]
Abstract
Recent studies show that adrenergic agonists and inflammatory cytokines can stimulate skeletal muscle glucose uptake, but it is unclear if glucose oxidation is similarly increased. Thus, the objective of this study was to determine the effects of ractopamine HCl (β1 agonist), zilpaterol HCl (β2 agonist), TNFα, and IL-6 on glucose uptake and oxidation rates in unstimulated and insulin-stimulated soleus muscle strips from adult Sprague-Dawley rats. Effects on phosphorylation of Akt (phospho-Akt), p38 MAPK (phospho-p38), and p44/42 MAPK (phospho-p44/42) was also determined. Incubation with insulin increased (P<0.05) glucose uptake by ∼47%, glucose oxidation by ∼32%, and phospho-Akt by ∼238%. Insulin also increased (P<0.05) phospho-p38, but only after 2h in incubation. Muscle incubated with β2 agonist alone exhibited ∼20% less (P<0.05) glucose uptake but ∼32% greater (P<0.05) glucose oxidation than unstimulated muscle. Moreover, co-incubation with insulin+β2 agonist increased (P<0.05) glucose oxidation and phospho-Akt compared to insulin alone. Conversely, β1 agonist did not appear to affect basal or insulin-stimulated glucose metabolism, and neither β agonist affected phospho-p44/42. TNFα and IL-6 increased (P<0.05) glucose oxidation by ∼23% and ∼33%, respectively, in the absence of insulin. This coincided with increased (P<0.05) phospho-p38 and phospho-p44/42 but not phospho-Akt. Furthermore, co-incubation of muscle with insulin+either cytokine yielded glucose oxidation rates that were similar to insulin alone, despite lower (P<0.05) phospho-Akt. Importantly, cytokine-mediated increases in glucose oxidation rates were not concomitant with greater glucose uptake. These results show that acute β2 adrenergic stimulation, but not β1 stimulation, directly increases fractional glucose oxidation in the absence of insulin and synergistically increases glucose oxidation when combined with insulin. The cytokines, TNFα and IL-6, likewise directly increased glucose oxidation in the absence of insulin, but were not additive in combination with insulin and in fact appeared to disrupt Akt-mediated insulin signaling. Rather, cytokines appear to be acting through MAPKs to elicit effects on glucose oxidation. Regardless, stimulation of glucose oxidation by these key stress factors did not rely upon greater glucose uptake, which may promote metabolic efficiency during acute stress by increasing fractional glucose oxidation without increasing total glucose consumption by muscle.
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Affiliation(s)
- Caitlin N Cadaret
- Department of Animal Science, University of Nebraska-Lincoln, Lincoln NE 68583, United States
| | - Kristin A Beede
- Department of Animal Science, University of Nebraska-Lincoln, Lincoln NE 68583, United States
| | - Hannah E Riley
- Department of Animal Science, University of Nebraska-Lincoln, Lincoln NE 68583, United States
| | - Dustin T Yates
- Department of Animal Science, University of Nebraska-Lincoln, Lincoln NE 68583, United States.
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McGinnis GR, Ballmann C, Peters B, Nanayakkara G, Roberts M, Amin R, Quindry JC. Interleukin-6 mediates exercise preconditioning against myocardial ischemia reperfusion injury. Am J Physiol Heart Circ Physiol 2015; 308:H1423-33. [DOI: 10.1152/ajpheart.00850.2014] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 03/23/2015] [Indexed: 12/25/2022]
Abstract
Interleukin-6 (IL-6) is a pleiotropic cytokine that protects against cardiac ischemia-reperfusion (I/R) injury following pharmacological and ischemic preconditioning (IPC), but the affiliated role in exercise preconditioning is unknown. Our study purpose was to characterize exercise-induced IL-6 cardiac signaling ( aim 1) and evaluate myocardial preconditioning ( aim 2). In aim 1, C57 and IL-6−/− mice underwent 3 days of treadmill exercise for 60 min/day at 18 m/min. Serum, gastrocnemius, and heart were collected preexercise, immediately postxercise, and 30 and 60 min following the final exercise session and analyzed for indexes of IL-6 signaling. For aim 2, a separate cohort of exercise-preconditioned (C57 EX and IL-6−/− EX) and sedentary (C57 SED and IL-6−/− SED) mice received surgical I/R injury (30 min I, 120 min R) or a time-matched sham operation. Ischemic and perfused tissues were examined for necrosis, apoptosis, and autophagy. In aim 1, serum IL-6 and IL-6 receptor (IL-6R), gastrocnemius, and myocardial IL-6R were increased following exercise in C57 mice only. Phosphorylated (p) signal transducer and activator of transcription 3 was increased in gastrocnemius and heart in C57 and IL-6−/− mice postexercise, whereas myocardial iNOS and cyclooxygenase-2 were unchanged in the exercised myocardium. Exercise protected C57 EX mice against I/R-induced arrhythmias and necrosis, whereas arrhythmia score and infarct outcomes were higher in C57 SED, IL-6−/− SED, and IL-6−/− EX mice compared with SH. C57 EX mice expressed increased p-p44/42 MAPK (Thr202/Tyr204) and p-p38 MAPK (Thr180/Tyr182) compared with IL-6−/− EX mice, suggesting pathway involvement in exercise preconditioning. Findings indicate exercise exerts cardioprotection via IL-6 and strongly implicates protective signaling originating from the exercised skeletal muscle.
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Affiliation(s)
| | - Christopher Ballmann
- Cardioprotection Laboratory, Auburn University School of Kinesiology, Auburn, Alabama
| | - Bridget Peters
- Cardioprotection Laboratory, Auburn University School of Kinesiology, Auburn, Alabama
| | - Gayani Nanayakkara
- Department of Drug Discovery and Development, Auburn University Harrison School of Pharmacy, Auburn, Alabama; and
| | - Michael Roberts
- Molecular and Applied Sciences Laboratory, Auburn University School of Kinesiology, Auburn, Alabama
| | - Rajesh Amin
- Department of Drug Discovery and Development, Auburn University Harrison School of Pharmacy, Auburn, Alabama; and
| | - John C. Quindry
- Cardioprotection Laboratory, Auburn University School of Kinesiology, Auburn, Alabama
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Saini A, Faulkner SH, Moir H, Warwick P, King JA, Nimmo MA. Interleukin-6 in combination with the interleukin-6 receptor stimulates glucose uptake in resting human skeletal muscle independently of insulin action. Diabetes Obes Metab 2014; 16:931-6. [PMID: 24702712 DOI: 10.1111/dom.12299] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 02/26/2014] [Accepted: 03/31/2014] [Indexed: 11/26/2022]
Abstract
AIM To examine if the physiological concentrations of both interleukin-6 (IL-6), in combination with IL-6 receptor (IL-6R), are able to stimulate glucose uptake in human skeletal muscle and to identify the associated signalling pathways. METHODS Skeletal muscle tissue (~60 mg) obtained from healthy female volunteers via muscle biopsy was subjected to incubation in the absence or presence of insulin (60 µU/ml), recombinant human IL-6 (rhIL-6) (4 ng/ml) or a combination of rhIL-6 (4 ng/ml) and rhIL-6R (100 ng/ml) for 30 min, with glucose transport measured for each incubation. Western blot analysis was conducted on key signalling proteins, protein kinase B (PKB/Akt), adenosine monophosphate kinase (AMPK) and mammalian target of rapamycin (mTOR) to gain an early insight into any differing transport mechanisms. RESULTS Human skeletal muscle exhibited increased glucose uptake with insulin (1.85-fold; p < 0.05) and stimulated phosphorylation of PKB/Akt and AMPK (0.98 ± 0.23 and 1.49 ± 0.13, respectively, phosphorylated: total; p < 0.05). IL-6/IL-6R increased phosphorylation of mTOR (fourfold, p < 0.05) compared to insulin, IL-6 alone and basal control. IL-6 did not stimulate glucose uptake but combined with IL-6R, induced 1.5-fold increase in glucose uptake (p < 0.05) and phosphorylation of AMPK (0.95 ± 0.19; phosphorylated: total, p < 0.05). CONCLUSIONS IL-6 in combination with IL-6R and not IL-6 alone increased glucose uptake in human skeletal muscle. IL-6/IL-6R-mediated glucose uptake occurred independently of PKB/Akt phosphorylation, showing that IL-6/IL-6R-induced glucose uptake is dependent on a divergent pathway.
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Affiliation(s)
- A Saini
- School of Sport, Exercise & Health Sciences, Loughborough University, Loughborough, UK
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White PJ, St-Pierre P, Charbonneau A, Mitchell PL, St-Amand E, Marcotte B, Marette A. Protectin DX alleviates insulin resistance by activating a myokine-liver glucoregulatory axis. Nat Med 2014; 20:664-9. [PMID: 24813250 PMCID: PMC4978533 DOI: 10.1038/nm.3549] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Accepted: 04/03/2014] [Indexed: 12/21/2022]
Abstract
We previously demonstrated that low biosynthesis of ω-3 derived pro-resolution mediators termed protectins is associated with an impaired global resolution capacity, inflammation and insulin resistance in obese high fat-fed mice1. These findings prompted a more direct study of the therapeutic potential of protectins for the treatment of metabolic disorders. Herein we found that protectin DX (PDX) exerts an unanticipated glucoregulatory activity that is distinct from its anti-inflammatory actions. PDX was found to selectively stimulate the release of the prototypic myokine interleukin-6 (IL-6) from skeletal muscle and thereby initiate a myokine-liver signaling axis, which blunts hepatic glucose production via Signal transducer and activator of transcription 3 (STAT3) mediated transcriptional suppression of the gluconeogenic program. These effects of PDX were abrogated in IL-6 null mice. PDX also activates AMP-activated protein kinase (AMPK) but in an IL-6 independent manner. Notably, we demonstrate that administration of PDX to obese diabetic db/db mice raises skeletal muscle IL-6 and substantially improves insulin sensitivity in this severe model of diabetes, without any impact on adipose tissue inflammation. Our findings thus support the development of PDX-based selective muscle IL-6 secretagogues as a new class of therapy for the treatment of insulin resistance and type 2 diabetes.
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Affiliation(s)
- Phillip J White
- 1] Department of Medicine, Québec Heart and Lung Institute, Laval University, Québec, Québec, Canada. [2] Institute of Nutrition and Functional Foods, Laval University, Québec, Québec, Canada
| | - Philippe St-Pierre
- 1] Department of Medicine, Québec Heart and Lung Institute, Laval University, Québec, Québec, Canada. [2] Institute of Nutrition and Functional Foods, Laval University, Québec, Québec, Canada
| | - Alexandre Charbonneau
- 1] Department of Medicine, Québec Heart and Lung Institute, Laval University, Québec, Québec, Canada. [2] Institute of Nutrition and Functional Foods, Laval University, Québec, Québec, Canada
| | - Patricia L Mitchell
- 1] Department of Medicine, Québec Heart and Lung Institute, Laval University, Québec, Québec, Canada. [2] Institute of Nutrition and Functional Foods, Laval University, Québec, Québec, Canada
| | - Emmanuelle St-Amand
- 1] Department of Medicine, Québec Heart and Lung Institute, Laval University, Québec, Québec, Canada. [2] Institute of Nutrition and Functional Foods, Laval University, Québec, Québec, Canada
| | - Bruno Marcotte
- 1] Department of Medicine, Québec Heart and Lung Institute, Laval University, Québec, Québec, Canada. [2] Institute of Nutrition and Functional Foods, Laval University, Québec, Québec, Canada
| | - André Marette
- 1] Department of Medicine, Québec Heart and Lung Institute, Laval University, Québec, Québec, Canada. [2] Institute of Nutrition and Functional Foods, Laval University, Québec, Québec, Canada
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Macdonald TL, Wan Z, Frendo-Cumbo S, Dyck DJ, Wright DC. IL-6 and epinephrine have divergent fiber type effects on intramuscular lipolysis. J Appl Physiol (1985) 2013; 115:1457-63. [PMID: 24052031 DOI: 10.1152/japplphysiol.00558.2013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
IL-6 is an exercise-regulated myokine that has been suggested to increase lipolysis in fast-twitch skeletal muscle. However, it is not known if a similar effect is present in slow-twitch muscle. Furthermore, epinephrine increases IL-6 secretion from skeletal muscle, suggesting that IL-6 could play a role in mediating the lipolytic effects of catecholamines. The purpose of this study was to determine whether IL-6 stimulates skeletal muscle lipolysis in a fiber type dependent manner and is required for epinephrine-stimulated lipolysis in murine skeletal muscle. Soleus and extensor digitorum longus (EDL) muscles from male C57BL/6J wild-type and IL-6(-/-) mice were incubated with 1 μM (183 ng/ml) epinephrine or 75 ng/ml recombinant IL-6 (rIL-6) for 60 min. IL-6 treatment increased 5'-AMP-activated protein kinase and signal transducer and activator of transcription 3 phosphorylation and glycerol release in isolated EDL but not soleus muscles from C57BL/6J mice. Conversely, epinephrine increased glycerol release in soleus but not EDL muscles from C57BL/6J mice. Basal lipolysis was elevated in soleus muscle from IL-6(-/-) mice, and this was associated with increases in adipose triglyceride lipase (ATGL) and its coactivator comparative gene identification-58 (CGI-58). The increase in ATGL content does not appear to be due to a loss of IL-6's direct effects, because ex vivo treatment with IL-6 failed to alter the expression of ATGL mRNA in soleus muscle. In summary, IL-6 stimulates lipolysis in glycolytic but not oxidative muscle, whereas the opposite fiber type effect is seen with epinephrine. The absence of IL-6 indirectly upregulates lipolysis, and this is associated with increases in ATGL and its coactivator CGI-58.
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Affiliation(s)
- Tara L Macdonald
- Department of Human Health and Nutritional Science, University of Guelph, Guelph, Ontario, Canada
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Nimmo MA, Leggate M, Viana JL, King JA. The effect of physical activity on mediators of inflammation. Diabetes Obes Metab 2013; 15 Suppl 3:51-60. [PMID: 24003921 DOI: 10.1111/dom.12156] [Citation(s) in RCA: 180] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Accepted: 04/27/2013] [Indexed: 01/03/2023]
Abstract
Being physically active and undertaking exercise on a regular basis are critical lifestyle behaviours which protect against the development of numerous chronic metabolic conditions. One of the key mechanisms by which physical activity exerts favourable health effects appears to be due to its capacity to reduce chronic low-grade inflammation. Single bouts of exercise have a potent anti-inflammatory influence with recent advances describing important effects of acute exercise on inflammatory mediators produced within skeletal muscle (myokines), adipose tissue (adipokines) and leucocytes. The accumulated effects of physical activity or exercise training on systemic inflammation have been studied widely within epidemiological research; however, information from intervention trials is still emerging. Current data suggest that the most marked improvements in the inflammatory profile are conferred with exercise performed at higher intensities, with combined aerobic and resistance exercise training potentially providing the greatest benefit. The purpose of this review is to describe recent advances in our understanding surrounding the acute and chronic effects of physical activity on key mediators of inflammation. Within this, particular attention is given to the interleukin-6 system owing to its apparent centrality in mediating the anti-inflammatory effects of exercise.
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Affiliation(s)
- M A Nimmo
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, Leicestershire, UK.
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Abstract
Interleukin-6 (IL-6) is a multifunctional cytokine that exerts its modulatory effects on cells that express membrane bound IL-6 receptors; however, IL-6 in a complex with soluble IL-6R can bind to any cell that express glycoprotein 130 (gp130). Thus, all cell types may respond to the pro- as well as anti-inflammatory properties of IL-6. Since the first report of acute exercise-induced increase in plasma IL-6 in the early 1990s, scientists have tried to elucidate the factors that influence the magnitude of change of plasma IL-6, as well as the possible biological roles of this cytokine. Evidence suggests that exercise intensity and duration as well as the form of contraction (e.g., eccentric or concentric) and muscle damage all influence IL-6 response to acute exercise. However, data on training status and performance on plasma IL-6 concentration changes during exercise are more inconclusive, as discussed in this review. In the last decade, most of the studies have focused on IL-6 as an 'energy sensor' possibly secreted by skeletal muscle that activates glycogenolysis in the liver and lipolysis in fat tissue in order to provide muscle with the growing energy demands during exercise.
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Gray SR, Kamolrat T. The effect of exercise induced cytokines on insulin stimulated glucose transport in C2C12 cells. Cytokine 2011; 55:221-8. [DOI: 10.1016/j.cyto.2011.04.019] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Revised: 04/21/2011] [Accepted: 04/26/2011] [Indexed: 01/18/2023]
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Kawaguchi T, Shiba N, Takano Y, Maeda T, Sata M. Hybrid training of voluntary and electrical muscle contractions decreased fasting blood glucose and serum interleukin-6 levels in elderly people: a pilot study. Appl Physiol Nutr Metab 2011; 36:276-83. [DOI: 10.1139/h10-108] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Takumi Kawaguchi
- Department of Digestive Disease Information and Research, and Department of Medicine, Kurume University School of Medicine, Kurume 830-0011, Japan
| | - Naoto Shiba
- Division of Rehabilitation, Kurume University Hospital, Kurume 830-0011, Japan
| | - Yoshio Takano
- Department of Physical Therapy Faculty of Medical Technology, Teikyo University Fukuoka, Omuta 836-8505, Japan
| | - Takashi Maeda
- Division of Rehabilitation, Kurume University Hospital, Kurume 830-0011, Japan
| | - Michio Sata
- Department of Digestive Disease Information and Research, and Department of Medicine, Kurume University School of Medicine, Kurume 830-0011, Japan
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Stefanyk LE, Dyck DJ. The interaction between adipokines, diet and exercise on muscle insulin sensitivity. Curr Opin Clin Nutr Metab Care 2010; 13:255-9. [PMID: 20216410 DOI: 10.1097/mco.0b013e328338236e] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
PURPOSE OF REVIEW High-fat diets lead to obesity and increase the risk of developing insulin resistance and type 2 diabetes. Adipose tissue and skeletal muscle act as endocrine organs, and produce various cytokines that can potentially alter peripheral insulin sensitivity. The purpose of the present review is to briefly summarize the effects of major cytokines (leptin, adiponectin, tumor necrosis factor-alpha, and interleukin-6) on muscle metabolism and insulin response, with a focus on the effects of diet and exercise. RECENT FINDINGS Leptin and adiponectin improve insulin sensitivity. However, in obesity there is a diminished response to these adipokines. This resistance can be induced very rapidly and may lead to subsequent impairments in insulin response. Tumor necrosis factor-alpha is a proinflammatory cytokine that has been implicated as a mediator of insulin resistance, particularly in obesity. Interleukin-6 was the first identified myokine. There is evidence to implicate interleukin-6 both as a mediator of impaired insulin action in obesity, and also as a facilitator of increased fuel metabolism during exercise. The effect of each of these cytokines on muscle insulin sensitivity can be modulated by diet and exercise. SUMMARY Much of the information summarized in the present review focuses on the effects of various cytokines in isolation, although in vivo there can be considerable interaction with each other. Future research should consider these potential interactions.
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Affiliation(s)
- Leslie E Stefanyk
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
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Frisard MI, McMillan RP, Marchand J, Wahlberg KA, Wu Y, Voelker KA, Heilbronn L, Haynie K, Muoio B, Li L, Hulver MW. Toll-like receptor 4 modulates skeletal muscle substrate metabolism. Am J Physiol Endocrinol Metab 2010; 298:E988-98. [PMID: 20179247 PMCID: PMC2867377 DOI: 10.1152/ajpendo.00307.2009] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Toll-like receptor 4 (TLR4), a protein integral to innate immunity, is elevated in skeletal muscle of obese and type 2 diabetic humans and has been implicated in the development of lipid-induced insulin resistance. The purpose of this study was to examine the role of TLR4 as a modulator of basal (non-insulin-stimulated) substrate metabolism in skeletal muscle with the hypothesis that its activation would result in reduced fatty acid oxidation and increased partitioning of fatty acids toward neutral lipid storage. Human skeletal muscle, rodent skeletal muscle, and skeletal muscle cell cultures were employed to study the functional consequences of TLR4 activation on glucose and fatty acid metabolism. Herein, we demonstrate that activation of TLR4 with low (metabolic endotoxemia) and high (septic conditions) doses of LPS results in increased glucose utilization and reduced fatty acid oxidation in skeletal muscle and that these changes in metabolism in vivo occur in concert with increased circulating triglycerides. Moreover, animals with a loss of TLR4 function possess increased oxidative capacity in skeletal muscle and present with lower fasting levels of triglycerides and nonesterified free fatty acids. Evidence is also presented to suggest that these changes in substrate metabolism under metabolic endotoxemic conditions are independent of skeletal muscle-derived proinflammatory cytokine production. This report illustrates that skeletal muscle is a target for circulating endotoxin and may provide critical insight into the link between a proinflammatory state and dysregulated metabolism as observed with obesity, type 2 diabetes, and metabolic syndrome.
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Affiliation(s)
- Madlyn I Frisard
- Virginia Polytechnic Institute and State University, Department of Human Nutrition, Foods, and Exercise, Blacksburg, VA 24061, USA
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