title: Expression of Toll-like receptors 2, 4 and 6 in different cell populations of the equine endometrium.
abstract: Subfertility in mares is mainly caused by endometrial diseases. Alterations of Toll-like receptors (TLRs) are associated with endometrial disorders in women. This study investigated TLRs 2, 4 and 6 in the equine endometrium. Endometria of 21 mares were examined by histology, PCR and immunohistochemistry. Tissues from 2 mares were considered normal. The remaining showed endometritis, endometrosis and/or angiosclerosis. TLRs 2, 4 and 6 were expressed as transcripts and proteins in all endometria. Immunohistochemistry detected TLRs 2, 4 and 6 in mast cells, luminal and glandular epithelial cells, stromal cells, endothelia, vascular smooth muscle and/or inflammatory cells. Between examined endometria numbers of immunopositive epithelial cells varied considerably; TLRs were located in their cytoplasm and/or the nucleus. All other cell types displayed a cytoplasmic staining. Results indicate a complex and cell-type-specific modulation of TLRs 2, 4 and 6 in the equine endometrium. The lack of a detectable association between a particular disease and a distinct cellular expression may be explained by the often combined presence of several factors with a possible influence on TLRs. This study expands the basic knowledge on equine endometrial immunity and will assist to uncover if immunological alterations contribute to uterine diseases of mares.
authors.affiliation: Institute of Pathology, Faculty of Veterinary Medicine, Leipzig University, An den Tierkliniken 33, 04103 Leipzig, Germany. Electronic address: sandra.schoeniger@vetmed.uni-leipzig.de.
authors.forename: Sandra
authors.initials: S
authors.lastname: Schöniger
authors.affiliation: Institute of Pathology, Faculty of Veterinary Medicine, Leipzig University, An den Tierkliniken 33, 04103 Leipzig, Germany.
authors.forename: Hilke
authors.initials: H
authors.lastname: Gräfe
authors.affiliation: Institute of Pathology, Faculty of Veterinary Medicine, Leipzig University, An den Tierkliniken 33, 04103 Leipzig, Germany.
authors.forename: Heinz-Adolf
authors.initials: HA
authors.lastname: Schoon
mesh_terms: D000818:Animals; D004717:Endometrium / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006736:Horses / Q000378:metabolism*; D051195:Toll-Like Receptor 2 / Q000096:biosynthesis*; D051197:Toll-Like Receptor 4 / Q000096:biosynthesis*; D051216:Toll-Like Receptor 6 / Q000096:biosynthesis*; D014591:Uterine Diseases / Q000378:metabolism / Q000473:pathology / Q000662:veterinary
chemical_list: D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D051216:Toll-Like Receptor 6
keywords: Endometrium; Equine; Immunohistochemistry; PCR; Toll-like receptors