Chronic equine laminitis is characterised by loss of GLUT1, GLUT4 and ENaC positive laminar keratinocytes.
Authors: Mobasheri A, Critchlow K, Clegg P D, Carter S D, Canessa C M
Journal: Equine veterinary journal
Summary
# Editorial Summary Chronic equine laminitis involves progressive structural breakdown of the laminae, yet the precise cellular changes underlying this deterioration remain poorly characterised. Mobasheri and colleagues used immunohistochemistry to compare protein expression in healthy versus laminitic laminar tissue, specifically examining the epithelial sodium channel (ENaC) and two glucose transporters (GLUT1 and GLUT4) as markers of metabolically active keratinocytes. Healthy laminae showed abundant staining for all three proteins localised to keratinocytes, whilst laminitic samples revealed complete loss of these markers alongside disorganised laminar architecture and fibrosis—indicating that keratinocyte dysfunction or loss is a defining feature of chronic disease. The findings establish alphaENaC, GLUT1, and GLUT4 as specific phenotypic markers for identifying and monitoring changes in the laminar keratinocyte population, offering clinicians and researchers a potential tool for grading tissue damage and evaluating therapeutic interventions. Further work investigating how common laminitis triggers (hypoxia, endotoxins, vasoactive compounds) affect expression of these membrane proteins could illuminate the cellular mechanisms driving keratinocyte loss and guide preventative or regenerative strategies.
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Practical Takeaways
- •These immunohistochemical markers provide a way to diagnose and monitor changes in laminar tissue quality and keratinocyte viability in laminitic horses
- •The replacement of specialized keratinocytes with fibrous scar tissue in chronic laminitis indicates irreversible structural damage and may inform prognosis
- •Understanding keratinocyte loss mechanisms could guide future therapeutic interventions targeting prevention of laminar cell death during acute laminitis
Key Findings
- •alphaENaC, GLUT1, and GLUT4 proteins are abundantly expressed in healthy equine laminar keratinocytes
- •Chronic laminitis is characterized by loss of alphaENaC, GLUT1, and GLUT4 positive keratinocytes with replacement by fibrous scar tissue
- •These three membrane proteins can serve as phenotypic markers for identification of metabolically active, differentiated laminar keratinocytes
- •Loss of laminar keratinocytes correlates with loss of laminar structure and function in chronic laminitis