BACKGROUND: The objective of the study was to evaluate the gene expression of inflammatory cytokines (interleukin [IL]-1b, IL-6, IL-8, IL-10, @entity5 @entity39 factor [TNF]-a, IL-1 receptor antagonist [ra] and serum amyloid A (SAA) in endometrial tissue and circulating leukocytes in response to uterine inoculation of 105 colony forming units (CFU) @entity526 in mares. Before inoculation, mares were classified as resistant or susceptible to persistent @entity7288 based on their uterine inflammatory response to infusion of 109 killed spermatozoa and histological assessment of the endometrial quality. Endometrial biopsies were obtained 3, 12, 24 and 72 hours (h) after bacterial inoculation and blood samples were obtained during the 7 day period post bacterial inoculation. Expression levels of cytokines and SAA were determined by quantitative real-time reverse transcriptase PCR (qRT-PCR). RESULTS: Compared to levels in a control biopsy (obtained in the subsequent estrous), resistant mares showed an up-regulation of IL-1b, IL-6, IL-8 and TNF-a at 3 h after @entity526 inoculation, while susceptible mares showed increased gene expression of IL-6 and IL-1ra. Susceptible mares had a significant lower gene expression of TNF-a,IL-6 and increased expression of IL-1ra 3 h after @entity526 inoculation compared to resistant mares. Susceptible mares showed a sustained and prolonged inflammatory response with increased gene expression levels of IL-1b, IL-8, IL-1ra and IL-1b:IL-1ra ratio throughout the entire study period (72 h), whereas levels in resistant mares returned to estrous control levels by 12 hours. Endometrial mRNA transcripts of IL-1b and IL-1ra were significantly higher in mares with heavy uterine bacterial growth compared to mares with no/mild growth.All blood parameters were unaffected by intrauterine @entity526 infusion, except for a lower gene expression of IL-10 at 168 h and an increased expression of IL-1ra at 48 h observed in susceptible mares compared to resistant mares. CONCLUSIONS: The current investigation suggests that endometrial mRNA transcripts of pro-inflammatory cytokines in response to @entity7288 are finely regulated in resistant mares, with initial high expression levels followed by normalization within a short period of time. Susceptible mares had a prolonged expression of pro-inflammatory cytokines, supporting the hypothesis that an unbalanced endometrial gene expression of inflammatory cytokines might play an important role in the pathogenesis of persistent @entity7288 .

Inflammatory responses to induced @entity7288 in mares resistant or susceptible to persistent XXXX .

@entity5 :: ('MESH:D009369', 'Disease') :: ['tumor'] @entity7288 :: ('MESH:D004716', 'Disease') :: ['endometritis'] @entity526 :: ('562', 'Species') :: ['Escherichia coli', 'E. coli'] @entity39 :: ('MESH:D009336', 'Disease') :: ['necrosis']
@entity7288 :: (MESH:D004716,Disease) :: ['endometritis']
