Decreased expression of p63, a regulator of epidermal stem cells, in the chronic laminitic equine hoof.
Authors: Carter, Engiles, Megee, Senoo, Galantino-Homer
Journal: Equine veterinary journal
Summary
# Editorial Summary Chronic laminitis involves progressive failure of the lamellar interface, yet the cellular mechanisms underlying this deterioration remain incompletely understood. Carter and colleagues investigated whether dysregulation of p63—a key regulator of epidermal stem cell self-renewal and proliferative capacity—contributes to lamellar pathology by comparing hoof tissues from five chronically laminitic horses with five healthy controls using immunofluorescence microscopy and quantitative immunoblotting. Laminitic horses demonstrated significantly reduced p63-positive cell populations throughout the distal lamellae, particularly in the abaxial region adjacent to the hoof wall, a finding correlated with the development of terminally differentiated, dysplastic and hyperkeratotic epithelium characteristic of lamellar wedges. The reduced p63 expression appears to shift the lamellar epithelium away from stem cell maintenance towards premature cellular differentiation, effectively compromising the tissue's regenerative capacity. These findings suggest that loss of stem cell potential may be central to lamellar failure in chronic laminitis, with potential therapeutic implications: the authors propose that autologous transplantation of p63-positive epidermal stem cells harvested from unaffected regions could offer a regenerative approach to restoring lamellar integrity in affected horses.
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Practical Takeaways
- •Loss of stem cell regulation via p63 downregulation may be a key mechanism in chronic laminitis development, suggesting future therapeutic targets beyond current management approaches
- •Autologous transplantation of p63-positive stem cells harvested from healthy hoof tissue could potentially offer regenerative treatment for chronic laminitis cases
- •Understanding that laminitic hooves have reduced capacity for normal epidermal renewal supports the importance of early intervention and prevention strategies to maintain healthy lamellar tissue
Key Findings
- •p63-positive epidermal stem cells were significantly reduced in laminitic hoof lamellae compared to control horses, particularly in the distal and abaxial regions
- •Decreased p63 expression was associated with formation of terminally differentiated, dysplastic, and hyperkeratotic epidermis in the abaxial lamellar region
- •Laminitic hoof epithelium demonstrated reduced proliferative potential with a shift towards differentiation, suggesting compromised epidermal stem cell activity
- •p63 expression patterns in equine skin are consistent with other species, establishing it as a marker for equine epidermal stem cell function