D on their uterine inflammatory response to infusion of 109 killed spermatozoa
D 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 upregulation of IL-1b, IL-6, IL-8 and TNF-a at 3 h after E. coli 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 E. coli 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 E. coli 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 endometritis 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 PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/27484364 of persistent endometritis. Keywords: Infectious endometritis, Susceptibility, Cytokines, Serum amyloid A* Correspondence: [email protected] 1 Department of Large Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Dyrlaegevej 68, Frederiksberg, Copenhagen DK-1870, Denmark Full list of author information is available at the end of the article?2012 Christoffersen et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Christoffersen et al. BMC Veterinary Research 2012, 8:41 http://www.biomedcentral.com/1746-6148/8/Page 2 ofBackground For Pan-RAS-IN-1 biological activity decades, infectious endometritis has been a major cause of infertility in mares [1,2]. An inflammatory response secondary to uterine infection appear to be a major contributor to a suboptimal uterine environment [1,3] and may play a role in the pathogenesis of early embryonic PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/27196668 loss. The ability of mares to eliminate uterine infections has been studied intensively for the past 40 years. Intrauterine infusion of bacteria (Streptococcus equi subsp. zooepidemicus) has been the traditional method for studying the pathogenesis of susceptibility to persistent infection and uterine defense mechanisms in mares. More than forty years ago, Hughes and L.
