Lamellar events related to insulin-like growth factor-1 receptor signalling in two models relevant to endocrinopathic laminitis.
Authors: Lane H E, Burns T A, Hegedus O C, Watts M R, Weber P S, Woltman K A, Geor R J, McCutcheon L J, Eades S C, Mathes L E, Belknap J K
Journal: Equine veterinary journal
Summary
# Editorial Summary Endocrinopathic laminitis remains a significant clinical challenge, with insulin dysregulation emerging as a key pathophysiological mechanism, though the precise cellular pathways driving lamellar damage have remained incompletely characterised. Lane and colleagues investigated how chronically elevated systemic insulin concentrations trigger pathological changes in the digital lamellae by examining insulin-like growth factor-1 (IGF-1) receptor signalling in two experimental models relevant to equine metabolic syndrome-associated laminitis, combining in vitro lamellar tissue culture with an in vivo hyperinsulinaemic model. The research demonstrated that aberrant IGF-1 receptor activation under conditions of hyperinsulinaemia triggers specific lamellar cellular events associated with compromised lamellar integrity and the early stages of laminitic degeneration, providing mechanistic insight into how insulin-resistant states predispose horses to laminitis. These findings have immediate implications for understanding why obesity, high-nonstructural carbohydrate forage exposure, and insulin dysregulation constitute major risk factors for laminitis, and suggest that targeting IGF-1 receptor signalling pathways may represent a therapeutic avenue for preventing laminitis in metabolically at-risk horses. For practitioners managing equine metabolic syndrome, this work underscores the critical importance of strict insulin regulation through dietary management and weight control in laminitis prevention strategies.
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Practical Takeaways
- •Monitor insulin levels and body condition in at-risk horses; obesity and insulin dysregulation are modifiable risk factors for laminitis
- •Restrict high-NSC forage (cereal grains, rich pasture) in horses with metabolic syndrome to reduce systemic insulin spikes and lamellar stress
- •Understanding the IGF-1 receptor mechanism offers potential therapeutic targets for preventing or treating endocrinopathic laminitis
Key Findings
- •High systemic insulin concentrations activate insulin-like growth factor-1 receptor signaling in digital lamellae
- •Insulin dysregulation, obesity, and high-NSC forage exposure are key risk factors for EMSAL
- •Lamellar cellular dysregulation is induced through IGF-1 receptor activation pathway in endocrinopathic laminitis models