Altered satellite cell dynamics accompany skeletal muscle atrophy during chronic illness, disuse, and aging

Abstract

Purpose of review This review explores recent research investigating the contribution of satellite cells (skeletal muscle stem cells) during muscle fiber atrophy as seen in periods of disuse, illness and aging. Recent findings Studies indicate reduced satellite cell activity and density in a variety of acute and chronic conditions characterized by robust muscle wasting. The direct contribution of satellite cells to unloading/denervation and chronic illness-induced atrophy remains controversial. Inflammation that accompanies acute trauma and illness likely impedes proper satellite cell differentiation and myogenesis, promoting the rapid onset of muscle wasting in these conditions. Transgenic mouse studies provide surprising evidence that age-related declines in satellite cell function and abundance are not causally related to the onset of sarcopenia in sedentary animals. Summary Recent clinical and pre-clinical studies indicate reduced abundance and dysregulated satellite cell activity that accompany muscle atrophy during periods of disuse, illness and aging, providing evidence for their therapeutic potential.

Divergent Regulation of Myotube Formation and Gene Expression by E2 and EPA during In-Vitro Differentiation of C2C12 Myoblasts

“…A reduced number of SCs and an inability to undergo myogenesis may be the outcome of, or contribute to skeletal muscle disorders such as atrophy, cachexia and sarcopenia [4]. In this regard, it has been the aim of many scientists to optimize myogenesis in-vitro to improve therapies to alleviate symptoms associated with muscle atrophy and degeneration.…”

Effects of astaxanthin on the protection of muscle health (Review)

“…Satellite cells (also known as skeletal muscle stem cells) are the precursors of skeletal muscle cells required for muscle mass maintenance and muscle regeneration following muscle atrophy (70). Previous studies have demonstrated the alterations of satellite cell activity and density by muscle catabolic conditions, such as disuse and ageing (71). Indeed, Yoshihara and co-authors (34) also revealed that the protection against disuse muscle atrophy exerted by astaxanthin might be due to the increase in satellite cell numbers.…”

RAGE in the pathophysiology of skeletal muscle

“…ubiquitin‐proteasome [UPP] and autophagy) and decrease in protein synthesis . Myogenic precursors, including SCs, also might contribute to the maintenance of skeletal mass in health and diseases, and recent work has shown that atrophy factors inhibit their regenerative and fusion potential …”