Muscle Protein Metabolism Regulatory Pathways

Muscle protein metabolism regulatory pathways are the coordinated signaling networks that govern the balance between muscle protein synthesis (MPS) and muscle protein breakdown (MPB) to maintain skeletal muscle proteostasis (Schiaffino et al., 2013). The Mechanistic Target of Rapamycin Complex 1 (mTORC1) serves as a central hub for anabolic signaling, responding to amino acids, mechanical loading, and growth factors like Insulin-like Growth Factor 1 (IGF-1) to stimulate protein translation (Goodman, 2014). Conversely, muscle atrophy is driven by the activation of the Ubiquitin-Proteasome System (UPS) and the Autophagy-Lysosome Pathway, which are largely regulated by the FoxO transcription factor family (Sandri et al., 2004). Myostatin, a member of the TGF-beta superfamily, acts as a critical negative regulator of muscle mass by inhibiting the Akt/mTOR pathway and promoting the expression of atrogenes (McPherron et al., 1997). Dysregulation of these pathways is a hallmark of diseases such as sarcopenia, cancer cachexia, and muscular dystrophy, where catabolic processes outpace anabolic ones (Cruz-Jentoft et al., 2010). Therapeutic strategies targeting these pathways include myostatin-neutralizing antibodies like bimagrumab and selective androgen receptor modulators (SARMs) like enobosarm, which aim to restore muscle mass and physical function (Tessier et al., 2021).

Other names

Muscle protein turnoverSkeletal muscle proteostasisMuscle mass regulation signaling

Modulation of the balance between protein synthesis (anabolism) and protein degradation (catabolism) through the regulation of mTORC1, FoxO, and myostatin signaling.