A metabolic link to skeletal muscle wasting and regeneration

Abstract

Due to its essential role in movement, insulating the internal organs, generating heat to maintain core body temperature, and acting as a major energy storage depot, any impairment to skeletal muscle structure and function may lead to an increase in both morbidity and mortality. In the context of skeletal muscle, altered metabolism is directly associated with numerous pathologies and disorders, including diabetes, and obesity, while many skeletal muscle pathologies have secondary changes in metabolism, including cancer cachexia, sarcopenia and the muscular dystrophies. Furthermore, the importance of cellular metabolism in the regulation of skeletal muscle stem cells is beginning to receive significant attention. Thus, it is clear that skeletal muscle metabolism is intricately linked to the regulation of skeletal muscle mass and regeneration. The aim of this review is to discuss some of the recent findings linking a change in metabolism to changes in skeletal muscle mass, as well as describing some of the recent studies in developmental, cancer and stem-cell biology that have identified a role for cellular metabolism in the regulation of stem cell function, a process termed “metabolic reprogramming.”

Metabolic Suppression by 3-Iodothyronamine Induced Muscle Cell Atrophy <i>via</i> Activation of FoxO–Proteasome Signaling and Downregulation of Akt1–S6K Signaling

“…1,6) Whereas physical stress entails metabolic support for muscle work, metabolic activity is not necessarily tied to physical activity. It is thus important to distinguish the role of the former from that of the latter to extend our understanding of the mechanisms of muscle homeostasis.…”

“…It is thus important to distinguish the role of the former from that of the latter to extend our understanding of the mechanisms of muscle homeostasis. 6) In the present study, we addressed whether metabolic suppression induces muscle cell atrophy in the absence of physical stress.…”

“…5) Because cellular respiration determines the MR, the hypometabolic state is seemingly a model of the muscle cell disuse and wasting. 6) Can metabolic suppression, then, induce muscle atrophy without physical involvement?…”

&beta;-Carotene Increases Muscle Mass and Hypertrophy in the Soleus Muscle in Mice

“…Decreases in habitual physical activity level due to injury or a sedentary lifestyle result in disuse-induced muscle wasting and dysfunction (1). The loss of skeletal muscle mass (muscle wasting) results in decreased mobility and eventually immobility, such as prolonged bed rest, and an increased risk of developing metabolic diseases such as obesity and type 2 diabetes (2). Any increase in mechanical loading induces hypertrophy, and unloading induces atrophy, indicating that physical exercise is the most preferred stimulus for prevention of muscle wasting.…”

Impact of psoas muscle index on short-term outcome after living donor liver transplantation

“…First, because the skeletal muscle is responsible for generating body heat to maintain the core body temperature, a loss of skeletal muscle mass may lead to a drop in the body temperature, reducing immune function (23,24). Second, as the skeletal muscle is generally destroyed during surgical stress and glutamine released from skeletal muscles activates lymphocytes and monocytes to maintain their immune function, a loss of the skeletal muscle mass may reduce the amount of glutamine released and immunity activated by lymphocytes and monocytes (25,26).…”