Proteinase Activated Receptor 4 in the Jejunum of Healthy Horses and of Horses With Epiploic Hernia.
Authors: Lambertini Carlotta, Bombardi Cristiano, Zannoni Augusta, Bernardini Chiara, Dondi Francesco, Morini Maria, Rinnovati Riccardo, Spadari Alessandro, Romagnoli Noemi
Journal: Frontiers in veterinary science
Summary
# Editorial Summary: PAR4 Expression in Equine Jejunal Disease Proteinase-activated receptor 4 (PAR4) modulates inflammatory and nociceptive signalling in the gastrointestinal tract, yet its role in equine small intestinal pathology remains poorly characterised. Researchers compared PAR4 distribution and expression in jejunal tissue from eight healthy horses against eight horses requiring surgical intervention for epiploic foramen herniation, using immunofluorescence, western blotting and qRT-PCR to quantify expression patterns. Whilst PAR4 mRNA levels remained comparable between groups, protein expression was significantly reduced in herniated cases, with altered cellular localisation predominantly in mast cells and serosal tissue rather than distributed throughout the lamina propria and submucosa as observed in healthy horses. The herniated group also demonstrated reduced leukocyte abundance in the mucous lamina propria, suggesting compromised mucosal immune function. These findings suggest PAR4 downregulation may contribute to the inflammatory dysregulation and impaired pain signalling associated with small intestinal strangulation, potentially explaining the sometimes non-specific clinical presentation of epiploic hernias and warranting further investigation into PAR4-targeted therapeutics for acute small intestinal disease.
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Practical Takeaways
- •Reduced PAR4 protein in epiploic hernia tissue may impair the horse's ability to regulate pain and inflammatory responses at the site of herniation
- •The altered distribution and expression of PAR4 in diseased tissue suggests a potential biomarker for identifying horses at risk of complications from small intestinal herniation
- •Understanding PAR4 involvement in epiploic hernia may eventually lead to targeted therapeutic interventions to modulate inflammation and pain in affected horses
Key Findings
- •PAR4 protein expression was significantly lower in jejunal tissue from horses with epiploic hernia compared to healthy horses
- •PAR4 is predominantly expressed in immune cells of the lamina propria and submucosa in healthy horses
- •In epiploic hernia cases, PAR4 immunoreactivity shifted to mast cells and was extensively distributed in the serosa
- •PAR4 mRNA levels were similar between healthy and diseased groups, but protein expression differed significantly