title: Type of Inflammation Differentially Affects Expression of Interleukin 1β and 6, Tumor Necrosis Factor-α and Toll-Like Receptors in Subclinical Endometritis in Mares.
abstract: Mares that fail to conceive or lose their embryos, without showing typical signs of clinical endometritis, should be suspected of subclinical endometritis (SE). In this study, the question was addressed: does SE fully activate selected mechanisms of innate immunity in mares? For this aim, expression of mRNAs for Toll-like Receptor 2 and 4 (TLR 2/4), interleukin 1β (IL-1β), interleukin 6 (IL-6) and tumor necrosis factor α (TNF) was examined in control mares versus either mares suffering from chronic endometritis (ChE) or subacute suppurative endometritis (SSE). The concentrations of IL-1β, IL-6 and TNF-α in supernatants from endometrial tissue cultures after 4 h incubation were measured using the enzyme immunoassay (EIA) method. Eighty-two warmblood mares, of known breeding history, were enrolled in this study. Based on histopathological assessment, mares were classified as suffering from ChE, SSE or as being healthy. In addition, immuno-localization of both TLR2 and TLR4 as well as TNF-α was investigated in the equine endometria. The mRNA expression of TLR2 (P < 0.01), IL-1β (P < 0.0001), IL-6 (P < 0.0001) and TLR4 and TNF (P < 0.05) was up-regulated in endometria of mares suffering from SSE compared with unaffected mares. Concentrations of IL-6 and TNF-α were increased only in mares exhibiting SSE, compared with unaffected (P < 0.01 for both) and ChE mares (P < 0.05 for both). Immuno-localization of TNF-α and TLRs was confirmed, both in unaffected and SE-affected endometria, and was present in the luminal and glandular epithelia and stromal cells. The severity of inflammation impacts the immune response and fosters activation of innate immunity mechanisms, as observed in the endometria of mares. The intracellular localization of TLRs and TNF-α in the endometria indicates a key role of endometrial epithelial and stromal cells in the immune response and inflammation.
authors.affiliation: Dep. of Reproductive Immunology and Pathology, Polish Academy of Sciences, Olsztyn, Poland.|Graduate School of Environment and Life Science Okayama University, Okayama, Japan.
authors.forename: Marta J
authors.identifier: 0000-0002-5117-9659
authors.initials: MJ
authors.lastname: Siemieniuch
authors.affiliation: Dep. of Reproductive Immunology and Pathology, Polish Academy of Sciences, Olsztyn, Poland.|Graduate School of Environment and Life Science Okayama University, Okayama, Japan.
authors.forename: Anna Z
authors.initials: AZ
authors.lastname: Szóstek
authors.affiliation: EQUI-MEDICA Equine Practice, Chojnice, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Gajos
authors.affiliation: Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Science, Wrocław, Poland.
authors.forename: Roland
authors.initials: R
authors.lastname: Kozdrowski
authors.affiliation: Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Science, Wrocław, Poland.
authors.forename: Marcin
authors.initials: M
authors.lastname: Nowak
authors.affiliation: Graduate School of Environment and Life Science Okayama University, Okayama, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Okuda
mesh_terms: D000818:Animals; D004716:Endometritis / Q000378:metabolism / Q000662:veterinary*; D005260:Female; D006734:Horse Diseases / Q000378:metabolism*; D006736:Horses; D007249:Inflammation / Q000145:classification* / Q000378:metabolism / Q000662:veterinary; D053583:Interleukin-1beta / Q000235:genetics / Q000378:metabolism*; D011374:Progesterone / Q000097:blood; D051193:Toll-Like Receptors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism*
chemical_list: D053583:Interleukin-1beta; D051193:Toll-Like Receptors; D014409:Tumor Necrosis Factor-alpha; D011374:Progesterone