Role Of Myokines Research Articles

Myokines in Home-Based Functional Electrical Stimulation-Induced Recovery of Skeletal Muscle in Elderly and Permanent Denervation.

Neuromuscular disorders, disuse, inadequate nutrition, metabolic diseases, cancer and aging produce muscle atrophy and this implies that there are different types of molecular triggers and signaling pathways for muscle wasting. Exercise and muscle contractions may counteract muscle atrophy by releasing a group of peptides, termed myokines, to protect the functionality and to enhance the exercise capacity of skeletal muscle. In this review, we are looking at the role of myokines in the recovery of permanent denervated and elderly skeletal muscle tissue. Since sub-clinical denervation events contribute to both atrophy and the decreased contractile speed of aged muscle, we saw a parallel to spinal cord injury and decided to look at both groups together. The muscle from lifelong active seniors has more muscle bulk and more slow fiber-type groupings than those of sedentary seniors, demonstrating that physical activity maintains slow motoneurons that reinnervate the transiently denervated muscle fibers. Furthermore, we summarized the evidence that muscle degeneration occur with irreversible Conus and Cauda Equina syndrome, a spinal cord injury in which the human leg muscles may be permanently disconnected from the peripheral nervous system. In these patients, suffering with an estreme case of muscle disuse, a complete loss of muscle fibers occurs within five to ten years after injury. Their recovered tetanic contractility, induced by home-based Functional Electrical Stimulation, can restore the muscle size and function in compliant Spinal Cord Injury patients, allowing them to perform electrical stimulation-supported stand-up training. Myokines are produced and released by muscle fibers under contraction and exert both local and systemic effects. Changes in patterns of myokine secretion, particularly of IGF-1 isoforms, occur in long-term Spinal Cord Injury persons and also in very aged people. Their modulation in Spinal Cord Injury and late aging are also key factors of home-based Functional Electrical Stimulation - mediated muscle recovery. Thus, Functional Electrical Stimulation should be prescribed in critical care units and nursing facilities, if persons are unable or reluctant to exercise. This will result in less frequent hospitalizations and a reduced burden on patients’ families and public health services.

Tu1515 - Unravelling the Role of Exercise Against NAFLD: Implications of the Anti-Lipogenic Role of Myokines

Tu1515 - Unravelling the Role of Exercise Against NAFLD: Implications of the Anti-Lipogenic Role of Myokines

The role of exercise-induced myokines in regulating metabolism.

Exercise has beneficial effects in ameliorating metabolic disorders, and a combined therapeutic regimen of regular exercise and pharmaceutical treatment is often recommended. Exercise biology is complex and it involves various metabolic and molecular changes that translate into changes in substrate utilization, enzyme activation, and alternatively, improvement in exercise performance. Besides the effect of exercise on muscle metabolism, it has recently been discovered that contracting muscle can induce secretion of molecules called myokines. In the past few decades, a number of myokines have been discovered, such as interleukin-6, irisin, myostatin, interleukin-15, brain-derived neurotrophic factor, β-aminoisobutyric acid, meteorin-like, leukemia inhibitory factor, and secreted protein acidic and rich in cysteine, through secretome analysis. The existence of myokines has enhanced our understanding of how muscles communicate with other organs such as adipose tissue, liver, bone, and brain to exert beneficial effects of exercise at the whole body level. In this review, we focus on the role of these myokines in regulating local muscle metabolism as well as systemic metabolism in an autocrine/paracrine/endocrine fashion. The therapeutic potential of myokines and the natural or synthetic compounds known to date that regulate myokines are also discussed.

Role of myokines in cardiovascular diseases and pre-analytical variables affecting their measurements.

Myokines, specifically cardiomyokines, have emerged as novel molecular targets that prevent and/or treat certain cardiovascular diseases due to its autocrine, paracrine and/or endocrine effects (1).

Skeletal Muscle as an Endocrine Organ: The Role of Myokines in Exercise Adaptations.

Exercise stimulates the release of proteins with autocrine, paracrine, or endocrine functions produced in skeletal muscle, termed myokines. Based on the current state of knowledge, the major physiological function of myokines is to protect the functionality and to enhance the exercise capacity of skeletal muscle. Myokines control adaptive processes in skeletal muscle by acting as paracrine regulators of fuel oxidation, hypertrophy, angiogenesis, inflammatory processes, and regulation of the extracellular matrix. Endocrine functions attributed to myokines are involved in body weight regulation, low-grade inflammation, insulin sensitivity, suppression of tumor growth, and improvement of cognitive function. Muscle-derived regulatory RNAs and metabolites, as well as the design of modified myokines, are promising novel directions for treatment of chronic diseases.

The role of myokines in muscle health and disease.

This article updates on the concept that muscle-derived cytokines (myokines) play important roles in muscle health and disease. Interleukin-6 (IL-6) is released from normal skeletal muscle in response to exercise, mediating both anti-inflammatory responses and metabolic adaptations, actions contradictory to the prevailing view that IL-6 is a proinflammatory cytokine that is inducing and propagating disease. The anti-inflammatory effects of IL-6 result from its trans-membrane signalling capability, via membrane-bound receptors, whereas its proinflammatory effects result instead from signalling via the soluble IL-6 receptor and gp130. IL-15 is elevated following exercise, promoting muscle fibre hypertrophy in some circumstances, while inducing fibre apoptosis in others. This functional divergence appears because of variations in expression of IL-15 receptor isoforms. Decorin, a recently described myokine, is also elevated following exercise in normal muscle, and promotes muscle fibre hypertrophy by competitively binding to, and thus inhibiting, myostatin, a negative regulator of muscle protein synthesis. Exercise-induced myostatin downregulation thus promotes muscle fibre growth, prompting recent trials of a biological myostatin inhibitor in inclusion body myositis. Myokines appear to exert diverse beneficial effects, though their mechanistic roles in myositis and other myopathologies remain poorly understood.

Role of myokines in regulation of a power exchange

This review presents new data in respect of polyfunctioning of the muscular system. It is shown that the muscles are able to synthesize and секретировать миокины, with auto-couple-and endocrine effects. Is represented by the signal cascade, which runs the transcription of interleukin -6 (Il-6) in the skeletal muscles. For example, IL-6, as an important миокина, shown its metabolic and антивоспалительные effects at physical loads. Considered the issue of the specificity of the cytokine response in muscle contraction. This position is confirmed by the fact that, in эндотоксемии induced by the introduction of липополисахарида, the muscles begin to produce, as the IL-6, and factor of tumor necrosis α. The biological sense of the rise of production of IL-6 and other миокинов is that миокины are the communication system, the input signal of different organs and systems, primarily in the liver, adipose tissue, and immune and endocrine, subordinating their work requirements of long-term muscles flex.

The diseasome of physical inactivity – and the role of myokines in muscle–fat cross talk

Type 2 diabetes, cardiovascular diseases, colon cancer, breast cancer, dementia and depression constitute a cluster of diseases, which defines 'a diseasome of physical inactivity'. Both physical inactivity and abdominal adiposity, reflecting accumulation of visceral fat mass, are associated with the occurrence of the diseases within the diseasome. Physical inactivity appears to be an independent and strong risk factor for accumulation of visceral fat, which again is a source of systemic inflammation. Chronic inflammation is involved in the pathogenesis of insulin resistance, atherosclerosis, neurodegeneration and tumour growth. Evidence suggests that the protective effect of exercise may to some extent be ascribed to the anti-inflammatory effect of regular exercise, which can be mediated via a reduction in visceral fat mass and/or by induction of an anti-inflammatory environment with each bout of exercise. The finding that muscles produce and release myokines provides a conceptual basis to understand the mechanisms whereby exercise influences metabolism and exerts anti-inflammatory effects. According to our theory, contracting skeletal muscles release myokines, which work in a hormone-like fashion, exerting specific endocrine effects on visceral fat. Other myokines work locally within the muscle via paracrine mechanisms, exerting their effects on signalling pathways involved in fat oxidation.

The International Union of Physiological Sciences IUPS Editorial VII

We are now very close to the start of the 2009 IUPS Congress of Physiological Sciences to be held in Kyoto’s magnificent International Conference Center, beautifully situated at the foot of Mount Hiei, only a 20-minute subway ride from Kyoto’s city center. This internationally famous conference

Exercise and inflammation

the purpose of this review series is to highlight the tremendous advancement in knowledge that has taken place over the last five to ten years regarding the interaction between physical exercise and inflammation. Many years ago, it was recognized that regular, moderate exercise reduced the risk of

Role of myokines in exercise and metabolism

During the past 20 yr, it has been well documented that exercise has a profound effect on the immune system. With the discovery that exercise provokes an increase in a number of cytokines, a possible link between skeletal muscle contractile activity and immune changes was established. For most of the last century, researchers sought a link between muscle contraction and humoral changes in the form of an "exercise factor," which could mediate some of the exercise-induced metabolic changes in other organs such as the liver and the adipose tissue. We suggest that cytokines and other peptides that are produced, expressed, and released by muscle fibers and exert either paracrine or endocrine effects should be classified as "myokines." Since the discovery of interleukin (IL)-6 release from contracting skeletal muscle, evidence has accumulated that supports an effect of IL-6 on metabolism. We suggested that muscle-derived IL-6 fulfils the criteria of an exercise factor and that such classes of cytokines should be named "myokines." Interestingly, recent research demonstrates that skeletal muscles can produce and express cytokines belonging to distinctly different families. Thus skeletal muscle has the capacity to express several myokines. To date the list includes IL-6, IL-8, and IL-15, and contractile activity plays a role in regulating the expression of these cytokines in skeletal muscle. The present review focuses on muscle-derived cytokines, their regulation by exercise, and their possible roles in metabolism and skeletal muscle function and it discusses which cytokines should be classified as true myokines.