The TWEAK-Fn14 system: breaking the silence of cytokine-induced skeletal muscle wasting

Area of Science:

• Muscle physiology and molecular biology
• Cellular signaling pathways
• Disease pathology

Background:

• Skeletal muscle atrophy is a significant complication of diseases and disuse.
• Proinflammatory cytokines are implicated in muscle wasting, but their role in disuse atrophy is less understood.
• Tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) is a newly identified potent inducer of muscle wasting.

Purpose of the Study:

• To elucidate the emerging roles and mechanisms of the TWEAK-Fn14 system in skeletal muscle.
• To investigate the involvement of TWEAK-Fn14 in different models of muscle atrophy and injury.
• To evaluate the therapeutic potential of targeting the TWEAK-Fn14 system for preventing muscle loss.

Main Methods:

• In vitro and in vivo studies examining TWEAK's effects on skeletal muscle.
• Analysis of TWEAK and its receptor Fn14 expression in various muscle atrophy models (denervation, immobilization, unloading).
• Investigation of proteolytic pathways activated by TWEAK in muscle.

Main Results:

• TWEAK activates proteolytic pathways, leading to myofibril protein degradation in skeletal muscle.
• TWEAK mediates muscle mass and function loss in denervation models.
• Expression of the TWEAK receptor, Fn14, is significantly upregulated in skeletal muscle under catabolic conditions.

Conclusions:

• The TWEAK-Fn14 signaling pathway plays a critical role in mediating skeletal muscle atrophy.
• Dysregulation of the TWEAK-Fn14 system contributes to muscle wasting in response to disuse and injury.
• Targeting the TWEAK-Fn14 system presents a promising therapeutic avenue for combating muscle loss.