Adapted physical exercise enhances activation and differentiation potential of satellite cells in the skeletal muscle of old mice

Abstract

During ageing, a progressive loss of skeletal muscle mass and a decrease in muscle strength and endurance take place, in the condition termed sarcopenia. The mechanisms of sarcopenia are complex and still unclear; however, it is known that muscle atrophy is associated with a decline in the number and/or efficiency of satellite cells, the main contributors to muscle regeneration. Physical exercise proved beneficial in sarcopenia; however, knowledge of the effect of adapted physical exercise on the myogenic properties of satellite cells in aged muscles is limited. In this study the amount and activation state of satellite cells as well as their proliferation and differentiation potential were assessed in situ by morphology, morphometry and immunocytochemistry at light and transmission electron microscopy on 28-month-old mice submitted to adapted aerobic physical exercise on a treadmill. Sedentary age-matched mice served as controls, and sedentary adult mice were used as a reference for an unperturbed control at an age when the capability of muscle regeneration is still high. The effect of physical exercise in aged muscles was further analysed by comparing the myogenic potential of satellite cells isolated from old running and old sedentary mice using an in vitro system that allows observation of the differentiation process under controlled experimental conditions. The results of this ex vivo and in vitro study demonstrated that adapted physical exercise increases the number and activation of satellite cells as well as their capability to differentiate into structurally and functionally correct myotubes (even though the age-related impairment in myotube formation is not fully reversed): this evidence further supports adapted physical exercise as a powerful, non-pharmacological approach to counteract sarcopenia and the age-related deterioration of satellite cell capabilities even at very advanced age.

Frailty and sarcopenia as the basis for the phenotypic manifestation of chronic diseases in older adults

“…This latter was observed even though the age-related impairment in myotube formation is not fully reversed (Cisterna et al, 2016). In addition, an anti-oxidative effect of exercise training has also been reported by Cobley et al, by showing that lifelong training attenuates agerelated macromolecule damage and increases HSP72 and catalase in muscle biopsies of human aged muscle com- Fig.…”

Adult Muscle Stem Cell Self-Renewal Induced by Endurance Exercise is Mediated by Inhibition of Mitochondrial Oxygen Consumption

“…Although no muscular hypertrophy was observed in exercised animals, prior studies have demonstrated that aerobic exercise changes satellite cell numbers and function, thus enhancing muscle regenerative capacity and preserving muscle mass during aging (Kurosaka et al 2009;Shefer et al 2010;Cisterna et al 2016). Indeed, we found that injured muscles in endurance-exercised animals had improved regenerative capacity, as indicated by a higher number of centrally-located nuclei, lower counts of inflammatory cells and less fibrosis (Fig.…”

“…Endurance exercise has been shown to protect against loss of satellite cells during aging, as well as increase their number and capacity to differentiate (Kurosaka et al 2009;Shefer et al 2010;Cisterna et al 2016). We thus verified if satellite cellmediated muscle regeneration after injury (Fig.…”

“…The higher density of newly formed fibers and lower inflammation in endurance-exercised mice suggest changes in satellite cell population (Shefer et al 2010;Cisterna et al 2016). We thus isolated and plated satellite cells from exercised and control animals (Fig.…”

Influence of anaerobic and aerobic exercise on age-related pathways in skeletal muscle

“…The negative impact of aging on the regulation of satellite cells causes a significant reduction in human skeletal muscle plasticity (Snijders et al, 2015). However, exercise increases the number and activation of satellite cells and their capacity to partially differentiate into myotubes with proper structure and function (Cisterna et al, 2016). Some of the mechanisms involved in sarcopenia are dependent on the negative regulation of satellite cells by the TGFβ pathway (Dumont et al, 2015).…”