Search results for "skeletal muscle"

Evaluation of an Antioxidant and Anti-inflammatory Cocktail Against Human Hypoactivity-Induced Skeletal Muscle Deconditioning

2020

International audience; Understanding the molecular pathways involved in the loss of skeletal muscle mass and function induced by muscle disuse is a crucial issue in the context of spaceflight as well as in the clinical field, and development of efficient countermeasures is needed. Recent studies have reported the importance of redox balance dysregulation as a major mechanism leading to muscle wasting. Our study aimed to evaluate the effects of an antioxidant/anti-inflammatory cocktail (741 mg of polyphenols, 138 mg of vitamin E, 80 mu g of selenium, and 2.1 g of omega-3) in the prevention of muscle deconditioning induced by long-term inactivity. The study consisted of 60 days of hypoactivi…

Age and muscle function are more closely associated with intracellular magnesium, as assessed by 31P magnetic resonance spectroscopy, than with serum…

2019

Total serum magnesium is a common clinical measurement for assessing magnesium status; however, magnesium in blood represents less than 1% of the body’s total magnesium content. We measured intramuscular ionized magnesium by phosphorus magnetic resonance spectroscopy (31P-MRS) and tested the hypothesis that this measure better correlates with skeletal muscle function and captures more closely the effect of aging than the traditional measure of total serum magnesium. Data were collected from 441 participants (age 24–98 years) in the Baltimore Longitudinal Study of Aging (BLSA), a study of normative aging that encompasses a broad age range. Results showed that intramuscular ionized magnesium …

Prevention of chemotherapy-induced cachexia by ACVR2B ligand blocking has different effects on heart and skeletal muscle

2017

Background Toxicity of chemotherapy on skeletal muscles and the heart may significantly contribute to cancer cachexia, mortality, and decreased quality of life. Doxorubicin (DOX) is an effective cytostatic agent, which unfortunately has toxic effects on many healthy tissues. Blocking of activin receptor type IIB (ACVR2B) ligands is an often used strategy to prevent skeletal muscle loss, but its effects on the heart are relatively unknown. Methods The effects of DOX treatment with or without pre-treatment with soluble ACVR2B-Fc (sACVR2B-Fc) were investigated. The mice were randomly assigned into one of the three groups: (1) vehicle (PBS)-treated controls, (2) DOX-treated mice (DOX), and (3) …

Dipeptidyl Peptidase IV as a Muscle Myokine

2020

Dipeptidyl peptidase IV (DPP-IV) is a unique serine protease that exists in a membrane bound state and in a soluble state in most tissues in the body. DPP-IV has multiple targets including cytokines, neuropeptides, and incretin hormones, and plays an important role in health and disease. Recent work suggests that skeletal muscle releases DPP-IV as a myokine and participates in control of muscle blood flow. However, few of the functions of DPP-IV as a myokine have been investigated to date and there is a poor understanding about what causes DPP-IV to be released from muscle.

Higher glucose availability augments the metabolic responses of the C2C12 myotubes to exercise-like electrical pulse stimulation

2021

The application of exercise-like electrical pulse simulation (EL-EPS) has become a widely used exercise mimetic in vitro. EL-EPS produces similar physiological responses as in vivo exercise, while less is known about the detailed metabolic effects. Routinely, the C2C12 myotubes are cultured in high-glucose medium (4.5 g/L), which may alter EL-EPS responses. In this study, we evaluate the metabolic effects of EL-EPS under the high- and low-glucose (1.0 g/L) conditions to understand how substrate availability affects the myotube response to EL-EPS. The C2C12 myotube, media, and cell-free media metabolites were analyzed using untargeted nuclear magnetic resonance (NMR)-based metabolomics. Furt…

2017

Background Many physiological and/or pathological conditions lead to muscle deconditioning, a well-described phenomenon characterized by a loss of strength and muscle power mainly due to the loss of muscle mass. Fatty infiltrations, or intermuscular adipose tissue (IMAT), are currently well-recognized components of muscle deconditioning. Despite the fact that IMAT is present in healthy human skeletal muscle, its increase and accumulation are linked to muscle dysfunction. Although IMAT development has been largely attributable to inactivity, the precise mechanisms of its establishment are still poorly understood. Because the sedentary lifestyle that accompanies age-related sarcopenia may fav…

A Novel Micronutrient Blend Mimics Calorie Restriction Transcriptomics in Multiple Tissues of Mice and Increases Lifespan and Mobility in C. elegans

2020

Background: We previously described a novel micronutrient blend that behaves like a putative calorie restriction mimetic. The aim of this paper was to analyze the beneficial effects of our micronutrient blend in mice and C. elegans, and compare them with calorie restriction. Methods: Whole transcriptomic analysis was performed in the brain cortex, skeletal muscle and heart in three groups of mice: old controls (30 months), old + calorie restriction and old + novel micronutrient blend. Longevity and vitality were tested in C. elegans. Results: The micronutrient blend elicited transcriptomic changes in a manner similar to those in the calorie-restricted group and different from those in the c…

Leukocyte and Skeletal Muscle Telomere Length and Body Composition in Monozygotic Twin Pairs Discordant for Long-term Hormone Replacement Therapy

2017

Estrogen-based hormone replacement therapy (HRT) may be associated with deceleration of cellular aging. We investigated whether long-term HRT has effects on leukocyte (LTL) or mean and minimum skeletal muscle telomere length (SMTL) in a design that controls for genotype and childhood environment. Associations between telomeres, body composition, and physical performance were also examined. Eleven monozygotic twin pairs (age 57.6 ± 1.8 years) discordant for HRT were studied. Mean duration of HRT use was 7.3 ± 3.7 years in the user sister, while their co-twins had never used HRT. LTL was measured by qPCR and SMTLs by southern blot. Body and muscle composition were estimated by bioimpedance an…

Role of Redox Signaling and Inflammation in Skeletal Muscle Adaptations to Training

2016

The inflammatory response to exercise-induced muscle damage has been extensively described. Exercise has important modulatory effects on immune function. These effects are mediated by diverse factors including pro-inflammatory cytokines, classical stress hormones, and hemodynamic effects leading to cell redistribution. As has been reported regarding oxidative stress, inflammation can have both detrimental and beneficial effects in skeletal muscle. In this review we will address the role of inflammation on protein metabolism in skeletal muscle. Specifically, we will review studies showing that treatment with cyclooxygenase-inhibiting drugs modulate the protein synthesis response to one bout …

New insights about the putative role of myokines in the context of cardiac rehabilitation and secondary cardiovascular prevention.

2017

Exercise training prevents the onset and the development of many chronic diseases, acting as an effective tool both for primary and for secondary prevention. Various mechanisms that may be the effectors of these beneficial effects have been proposed during the past decades: some of these are well recognized, others less. Muscular myokines, released during and after muscular contraction, have been proposed as key mediators of the systemic effects of the exercise. Nevertheless the availability of an impressive amount of evidence regarding the systemic effects of muscle-derived factors, few studies have examined key issues: (I) if skeletal muscle cells themselves are the main source of cytokin…