Inflammatory responses to induced infectious endometritis in mares resistant or susceptible to persistent endometritis.
Authors: Christoffersen Mette, Woodward Elizabeth, Bojesen Anders M, Jacobsen Stine, Petersen Morten R, Troedsson Mats Ht, Lehn-Jensen Henrik
Journal: BMC veterinary research
Summary
# Editorial Summary Researchers compared the inflammatory gene expression profiles of mares genetically predisposed to either resist or develop persistent endometritis following controlled uterine infection with *Escherichia coli*. Mares were first phenotyped as resistant or susceptible based on their endometrial response to spermatozoa challenge and tissue quality assessment, then inoculated with 10⁵ CFU of bacteria, with endometrial biopsies collected at 3, 12, 24 and 72 hours post-infection and blood samples monitored over seven days to measure cytokine expression (IL-1β, IL-6, IL-8, IL-10, TNF-α, IL-1ra) and serum amyloid A via quantitative real-time PCR. The differential inflammatory signalling between resistant and susceptible mares—particularly in how quickly and robustly they mounted local and systemic immune responses—suggests that inherent variations in endometrial immunocompetence determine susceptibility to chronic post-breeding endometritis, a condition responsible for significant subfertility in mares. Understanding these mechanistic differences offers potential targets for identifying high-risk individuals prior to breeding and could inform therapeutic interventions aimed at enhancing uterine clearance in susceptible animals. For practitioners managing breeding mares with recurrent endometritis, this work underscores the importance of endometrial quality assessment and suggests that some animals may require modified breeding protocols or additional immunological support rather than repeated empirical treatment.
Read the full abstract on PubMed
Practical Takeaways
- •Mares with poor endometrial quality and strong inflammatory responses to spermatozoa are at higher risk for developing persistent endometritis and may require enhanced management during breeding
- •Early inflammatory marker assessment in endometrial tissue could potentially identify susceptible mares before breeding season to inform breeding decisions or preventive protocols
- •Understanding individual mare variation in inflammatory response mechanisms may enable targeted therapeutic interventions for those prone to persistent endometritis
Key Findings
- •Mares susceptible to persistent endometritis showed significantly different inflammatory cytokine gene expression patterns compared to resistant mares following E. coli inoculation
- •IL-1β, IL-6, IL-8, TNF-α, and SAA expression levels in endometrial tissue and circulating leukocytes were measured at multiple time points (3-72 hours post-inoculation)
- •Pre-inoculation classification of mares as resistant or susceptible based on response to killed spermatozoa infusion and endometrial histology predicted differential inflammatory responses to bacterial challenge