Cytokeratins of the matrices of the chestnut (torus carpeus) and periople in horses with acute laminitis.
Authors: Wattle
Journal: American journal of veterinary research
Summary
Wattle's investigation examined whether the morphological changes visible in the chestnut and periople during acute equine laminitis result from disrupted keratinocyte differentiation, reasoning that these non-weight-bearing tissues might reveal primary epidermal pathology independent of mechanical loading. Tissue samples from eight acutely laminitic horses (collected within 48 hours of clinical onset) and healthy controls were analysed using one- and two-dimensional gel electrophoresis and immunohistochemical staining to characterise cytokeratin expression patterns. Whilst the overall cytokeratin profiles remained similar between laminitic and normal horses, immunohistochemistry revealed altered cytokeratin expression specifically in basal cells of the hoof wall stratum externum matrix and chestnut matrix in the most severely affected laminitic horses—a finding consistent with inhibited differentiation rather than simple protein depletion. These immunohistochemical changes suggest that the epidermal pathology observed in acute laminitis is indeed primary to the tissue itself rather than secondary to weight-bearing forces, making examination of the periople and chestnut clinically relevant as indicators of underlying keratinocyte dysfunction. For practitioners, this work supports the notion that early morphological signs in non-weight-bearing tissues warrant attention as potential markers of systemic laminitic processes, though the precise mechanism triggering keratinocyte differentiation failure remains to be established.
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Practical Takeaways
- •Laminitis causes changes in keratinocyte differentiation in non-weight-bearing tissues, suggesting the disease involves systemic epidermal dysfunction rather than purely mechanical failure
- •The morphologic changes seen in chestnuts and periople during acute laminitis reflect primary cellular changes in keratinocyte maturation, which may help guide understanding of disease progression
- •Early assessment of tissue changes in non-weight-bearing areas may provide diagnostic insight into acute laminitis pathophysiology
Key Findings
- •Horses with acute laminitis expressed the same set of cytokeratins as clinically normal horses at the biochemical level
- •Immunohistochemical analysis revealed altered cytokeratin expression in basal cells of the hoof wall matrix and chestnut matrix in laminitic horses
- •Inhibition of keratinocyte differentiation was observed in non-weight-bearing tissues (chestnut and periople) in horses with severe morphologic changes
- •Epidermal changes in acute laminitis appear to be primary lesions independent of weight-bearing forces