What Are the Mechanisms Underlying Denervation Atrophy?
The atrophy observed in denervated muscle is primarily driven by a decrease in protein synthesis and an increase in protein degradation. Key pathways involved include:
1. Ubiquitin-Proteasome Pathway: This is a major pathway for protein degradation in cells. Denervation upregulates components of this pathway, leading to increased breakdown of muscle proteins. 2. Autophagy: This is a process where cells degrade their own components through the lysosomal machinery. Increased autophagy is often seen in denervated muscle fibers. 3. Apoptosis: Programmed cell death or apoptosis may also contribute to muscle atrophy, although its role is less well-defined compared to other mechanisms.
