Glucose Ingestion Inhibits Endurance Exercise-Induced IL-6 Producing Macrophage Infiltration in Mice Muscle

Abstract

Background: Carbohydrate (CHO) supplementation during exercise attenuates exercise-induced increases in plasma Interleukin (IL)-6 concentration. However, the effects of CHO supplementation on muscle IL-6 production during endurance exercise is controversial. The purpose of this study was to investigate the effects of CHO supplementation on muscle IL-6 production during endurance exercise with a special focus on the IL-6 producing cells. Methods: C57BL/6J mice were divided into three groups—sedentary with water ingestion group as the control (Con; n = 10), exercise with water ingestion group (Ex; n = 10), and exercise with 6% glucose ingestion group (Ex + glucose; n = 10). The Ex and Ex + glucose groups completed 3 h of treadmill running (24 m/min, 7% incline) and were sacrificed immediately after exercise. Results: The exercise-induced increases of plasma IL-6 concentration and gastrocnemius IL-6 gene expression were attenuated by glucose ingestion. However, the increases of soleus IL-6 gene expression and gastrocnemius and soleus IL-6 protein expression were not attenuated by glucose ingestion. Furthermore, we observed that macrophages that infiltrated muscle produce IL-6 and glucose ingestion attenuated the infiltration of IL-6-producing macrophages. Conclusion: This study revealed that infiltrating macrophages may be one type of IL-6-producing cells during endurance exercise, and the infiltration of these cells in muscle was attenuated by glucose ingestion. However, the effects of glucose ingestion on muscle IL-6 production were limited.

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“…It may affect the normal patterns of children and adolescents growth 2 . Obesity among children and adolescents is continuing to rise and reach up to 18% of children and adolescents aged [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] in 2016 according to the World Health Organization (WHO) 3 . The aetiology of obesity is multimodal and multifactorial, which makes it difficult to identify causative and contributing factors 4 .…”

“…IL-6 is a pleiotropic, multifunctional immunoregulatory cytokine that was first described as a B cell stimulatory factor 2 that enhances antibody production by activated B cells 16 . IL-6 is secreted by macrophages, adipose tissue, contracting skeletal muscles, and many other sources 17 . Several studies suggested an important role for IL-6 in glucose metabolism and fat metabolism by a lipolytic action with an antiobesity effect 18 .…”

β-hydroxy-β -methylbutyrate supplementation benefits the effects of resistance training on body fat reduction via increased irisin expression in white adipose tissue

“…We further assessed the synergistic effect of RT and CaHMB on cytokines related to fat metabolism in skeletal muscle and adipose tissue. It is important to point out that cytokine expression has been reported to be different between gastrocnemius and soleus muscles [ 46 ]. Furthermore, the secretion of FNDC-5 is around 40% higher in slow-oxidative fibre-type muscle (i.e.…”

Crosstalk Between Skeletal Muscle and Immune System: Which Roles Do IL-6 and Glutamine Play?

“…It suggests that increased levels of IL-6 in the absence of exercise may be directly related to a higher degree of physical inactivity and metabolic syndrome (Bruun et al, 2006;Fischer et al, 2007). This "contradictory action" of IL-6 occurs because this interleukin can be produced not only by the immune system cells, but also by different tissues such as adipocytes (Coppack, 2001;Lyngsø et al, 2002), and muscle fibers through the initial infiltration of macrophages in the muscle tissue (Tominaga et al, 2019) or by the subsequent production of this interleukin by myoblasts (Gallucci et al, 1998;Pillon et al, 2013), thus triggering systemic pro-inflammatory (Coppack, 2001) or anti-inflammatory (Gallucci et al, 1998;Pillon et al, 2013) effects, respectively.…”

“…Despite lacking recent original studies characterizing the biomolecular mechanisms behind the elevations of IL-6 in muscle fibers, some synergistic action between the infiltration of immune cells mediated by the practice of physical exercise in muscle tissue has been proposed as a determining factor for the regulation of muscle damage and inflammation (Gallucci et al, 1998;Kawanishi et al, 2016;Tominaga et al, 2019). In this context, the total plasma level of IL-6 can also be partially altered by immunological cells from the innate immune system (such as macrophages and neutrophils), as well as from the adaptive immune system (such as T and B cells) (Nielsen et al, 1996), depending on the training stimulus performed, ideally inducing transient pro-inflammatory effects, with a posterior anti-inflammatory response (Kawanishi et al, 2016).…”