Temporal localization of immunoreactive transforming growth factor beta1 in normal equine skin and in full-thickness dermal wounds.
Authors: Theoret Christine L, Barber Spencer M, Gordon John R
Journal: Veterinary surgery : VS
Summary
# Editorial Summary TGF-β1 plays a central role in orchestrating tissue repair, yet its precise spatiotemporal expression during equine wound healing remained poorly characterised. Using immunohistochemical analysis of full-thickness excisional wounds created on the metacarpal and thoracic regions of four horses (aged 2–4 years), Theoret and colleagues tracked TGF-β1 protein localisation from pre-wounding through to day 14 post-injury. Notably, unwounded epidermis displayed moderate TGF-β1 staining throughout all layers whilst the dermis showed minimal reactivity; following injury, migrating epithelium temporarily lost immunoreactivity but regenerated it during the remodelling phase, whilst macrophages and fibroblasts of the inflammatory exudate and granulation tissue respectively demonstrated sustained and progressively increasing staining. These findings reveal TGF-β1 as a constitutively expressed growth factor in normal equine skin that is dynamically upregulated post-injury, with expression patterns strongly correlating to the cellular activities of wound repair. For equine practitioners, this work provides foundational knowledge supporting future strategies to modulate aberrant healing responses—particularly relevant for managing chronic wounds and excessive scarring in high-motion areas such as the distal limb, where dysregulated TGF-β1 signalling may contribute to fibrosis and functional compromise.
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Practical Takeaways
- •Understanding TGF-beta1 expression patterns during equine wound healing may eventually enable targeted therapies to optimize tissue repair and prevent pathological scarring
- •This foundational work maps normal healing biology in horses and provides a baseline for comparing aberrant wound repair responses (such as excessive scar tissue formation)
- •The temporal expression of TGF-beta1 by different cell types suggests multiple intervention windows if future therapies aim to modulate growth factor activity during healing
Key Findings
- •TGF-beta1 is constitutively expressed in normal unwounded equine epidermis throughout all layers but relatively absent in dermis
- •Upon wounding, migrating epithelium loses TGF-beta1 staining while epidermal appendages retain strong immunoreactivity
- •Macrophage TGF-beta1 expression in inflammatory exudate diminishes over time while granulation tissue fibroblasts show sustained and increasing expression throughout repair
- •No differences in TGF-beta1 localization patterns were detected between limb and thoracic wounds