PTB Regulates Keloid Fibroblast Migration and Proliferation Through Autophagy.

Area of Science:

• Fibroblast biology
• Cellular signaling
• Wound healing research

Background:

• Keloid disease is a chronic fibroproliferative condition with inadequate treatments.
• Understanding the cellular mechanisms underlying keloid formation is crucial for developing effective therapies.

Purpose of the Study:

• To investigate autophagy levels in keloid fibroblasts (KFbs) compared to normal fibroblasts (NFbs).
• To determine if polypyrimidine tract-binding protein (PTB) regulates KFb biological functions, particularly via autophagy.

Main Methods:

• Transmission electron microscopy to observe fibroblast morphology and autophagosome/autolysosome formation.
• PTB gene silencing using siRNA to assess its impact on KFb proliferation and migration.
• Acridine orange and LysoTracker Red staining to quantify acidic compartments and autophagy.
• Pharmacological inhibition of autophagy using wortmannin to elucidate PTB's role.

Main Results:

• Keloid fibroblasts exhibit higher levels of autophagosomes and autolysosomes than normal fibroblasts.
• PTB knockdown significantly reduced KFb migration and proliferation.
• Inhibition of autophagy abolished the effects of PTB knockdown on KFb migration and proliferation.
• PTB regulates KFb migration and proliferation via autophagy, but not collagen I and III synthesis.

Conclusions:

• PTB plays a critical role in regulating keloid fibroblast migration and proliferation through the induction of autophagy.
• Collagen synthesis in keloid fibroblasts is regulated by PTB in an autophagy-independent manner.
• These findings highlight PTB and autophagy as potential therapeutic targets for managing keloid disease.