Suppressing PDGFRβ Signaling Enhances Myocyte Fusion to Promote Skeletal Muscle Regeneration

Area of Science:

• Muscle biology
• Regenerative medicine
• Cell signaling

Background:

• Skeletal muscle regeneration relies on myocyte fusion to form multinucleated myotubes.
• The precise molecular regulators of this critical fusion process remain incompletely understood.

Purpose of the Study:

• To investigate the role of platelet-derived growth factor receptor beta (PDGFRβ) signaling in adult skeletal muscle cell fusion and regeneration.
• To identify PDGFRβ as a potential therapeutic target for enhancing muscle repair.

Main Methods:

• Genetic manipulation of Pdgfrβ in mouse models.
• Pharmacological inhibition and activation of PDGFRβ signaling.
• Analysis of myotube formation, myofiber size, and muscle regeneration.
• Transcriptomics analysis to elucidate signaling pathways.
• Assessment of STAT1 activation and phosphorylation.

Main Results:

• Genetic deletion of Pdgfrβ improved muscle regeneration and increased myofiber size.
• PDGFRβ activation impaired muscle repair and stalled myotube development by limiting cell spreading.
• Inhibition of PDGFRβ promoted myonuclear accretion in mouse and human myotubes.
• PDGFRβ signaling interacts with TGFβ signaling and requires STAT1 activation.

Conclusions:

• PDGFRβ signaling acts as a crucial checkpoint in skeletal muscle regeneration.
• Targeting PDGFRβ, particularly by inhibiting STAT1 phosphorylation, can accelerate muscle repair and increase myofiber size.