Smad2/3 Signaling Mediates the Atrophic Response in Vocal Fold Myoblasts In Vitro

Area of Science:

• Muscle Biology
• Cell Signaling
• Voice Disorders

Background:

• Vocal fold (VF) muscle atrophy is linked to neuromuscular disorders and aging, causing voice disability.
• Myostatin and TGF-β1 are implicated in muscle atrophy and are upregulated in VF injury.
• The role of Smad2/3 signaling in laryngeal muscles is not fully understood.

Purpose of the Study:

• To investigate Smad2/3-dependent atrophic responses in VF skeletal muscle cells.
• To provide foundational insights for developing therapeutic strategies for VF muscle atrophy.

Main Methods:

• In vitro study using rat thyroarytenoid myoblasts.
• Treatment with myostatin or TGF-β1, with or without ALK4/5 inhibitor or Smad2/3 siRNA.
• Assessment of myotube formation, Smad2/3 activation, and gene transcription via immunofluorescence and qRT-PCR.

Main Results:

• Both myostatin and TGF-β1 suppressed myogenic differentiation and increased Smad2/3 signaling.
• TGF-β1 induced a more pronounced atrophic response than myostatin.
• Smad2/3 knockdown promoted myogenic differentiation, confirming its role in VF muscle atrophy.

Conclusions:

• Smad2/3 signaling is a key mediator of differentiation in VF myoblasts.
• TGF-β1 elicits a stronger atrophic response than myostatin via Smad2/3 signaling.
• Targeting Smad2/3 signaling presents a potential therapeutic avenue for VF muscle atrophy.