EDA Fibronectin Microarchitecture and YAP Translocation During Wound Closure.

Area of Science:

• Biomedical Engineering
• Cell Biology
• Tissue Engineering

Background:

• Fibronectin (Fn) is a key extracellular matrix protein.
• The EDA Fn isoform is crucial for tissue repair but linked to both regeneration and fibrosis.
• Yes-associated protein (YAP) signaling is vital for wound healing and implicated in regenerative and fibrotic outcomes.

Purpose of the Study:

• To investigate how EDA Fn organization modulates YAP translocation during normal and fibrotic wound closure.
• To understand the role of microenvironmental stiffness in EDA Fn matrix assembly and YAP activity.
• To explore potential therapeutic strategies for promoting regenerative wound repair.

Main Methods:

• Human dermal fibroblasts cultured on polydimethylsiloxane (PDMS) substrates simulating soft (18 kPa) and stiff (146 kPa) wound environments.
• Pharmacological inhibition of EDA Fn binding (Irigenin) and YAP activity (CA3).
• Assessment of EDA Fn matrix organization (fiber alignment, thickness) and YAP translocation/activity.

Main Results:

• Stiffer substrates (fibrotic) promoted aligned EDA Fn matrices with thinner fibers, indicating increased tension.
• Inhibiting EDA Fn binding or YAP activity resulted in randomly organized, thicker EDA Fn fibers, reducing apparent tension.
• Fibroblasts showed increased YAP activity on soft substrates but decreased activity on stiff substrates; Irigenin or CA3 treatment on stiff substrates restored YAP activity.

Conclusions:

• EDA Fn organization is mechanosensitive and influences YAP activity during wound healing.
• Disrupted signaling between EDA Fn organization and YAP translocation may underlie fibrotic wound repair.
• Restoring normal EDA Fn matrix organization could be a strategy to drive regenerative wound repair.