Spatial and temporal expression of types I and II receptors for transforming growth factor beta in normal equine skin and dermal wounds.
Authors: De Martin Isabelle, Theoret Christine L
Journal: Veterinary surgery : VS
Summary
# Editorial Summary TGF-β (transforming growth factor beta) drives collagen deposition and scarring through receptor-mediated signalling, making it a logical target for preventing excessive granulation tissue in equine limb wounds. De Martin and Theoret used immunohistochemistry to map the spatial and temporal expression of TGF-β receptor types I and II (RI and RII) across normal skin, normally healing wounds, and wounds complicated by exuberant granulation tissue (EGT), sampling eight horses at baseline, 12 and 24 hours post-wounding, and at 5, 10 and 14 days. Both receptor types were consistently co-localised in the same cell populations across all tissue types and healing phases, but critically, staining intensity increased significantly in limb wounds with EGT compared to normally healing limb wounds and thoracic wounds during the proliferative phase, reflecting the heightened cellularity of proud flesh. The heightened TGF-β receptor signalling in EGT suggests a window of opportunity for therapeutic intervention—receptor antagonists applied during early proliferation might interrupt pathological matrix deposition before scarring becomes established, though the researchers note that receptor expression patterns are similar between normal and pathological healing, suggesting selectivity of timing rather than tissue type will be key. For practitioners managing distal limb wounds, these findings indicate that anti-scarring strategies targeting TGF-β signalling should ideally begin during days 5–10 post-injury when receptor expression peaks within hypertrophic granulation tissue.
Read the full abstract on PubMed
Practical Takeaways
- •Understanding TGF-beta receptor expression during different wound healing phases may guide optimal timing for receptor antagonist use to reduce scarring in equine limb wounds
- •The heightened receptor activity in exuberant granulation tissue supports the biological basis for interventions targeting this pathological healing response
- •Limb wounds show fundamentally different receptor activity patterns than thoracic wounds, suggesting location-specific treatment approaches may be warranted
Key Findings
- •TGF-beta receptors (RI and RII) are co-localized in both unwounded and wounded equine skin throughout healing phases
- •Limb wounds with exuberant granulation tissue showed greater staining intensity for RI and RII compared to normally healing wounds due to increased cellularity during proliferative phase
- •No differences in receptor expression patterns were detected between limb and thoracic wounds or between normal healing and EGT wounds at any timepoint
- •Strong RI and RII expression in EGT suggests active signalling for matrix protein stimulation that may contribute to scarring