Premium
The Localization of Toll‐like Receptor 2 ( TLR 2) in the Endometrium and the Cervix of Dogs at Different Stages of the Oestrous Cycle and with Pyometra
Author(s) -
Chotimanukul S,
Sirivaidyapong S
Publication year - 2012
Publication title -
reproduction in domestic animals
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.546
H-Index - 66
eISSN - 1439-0531
pISSN - 0936-6768
DOI - 10.1111/rda.12104
Subject(s) - pyometra , estrous cycle , cervix , uterine horns , endometrium , andrology , tlr2 , uterus , medicine , follicular phase , immunohistochemistry , epithelium , biology , endocrinology , pathology , receptor , innate immune system , cancer
Content The aim of this study was to localize and evaluate the role of T oll‐like receptor 2 ( TLR 2) in the endometrium and cervix of bitches at different stages of the oestrous cycle and in bitches with pyometra. Sixty‐seven nulliparous dogs, ranging in age from 1 to 13 years, were allocated amongst five groups (pro‐oestrus; n = 7, oestrus; n = 10, dioestrus; n = 16, anoestrus; n = 11, pyometra; n = 23). Blood samples were collected for the measurement of progesterone concentration. The mean progesterone concentration was analysed as a parameter for validating the stage of the oestrous cycle in bitches. Tissues collected from uterine horn and cervix were fixed in 4% paraformaldehyde for immunohistochemical examination of TLR 2. The expression of TLR 2 was assessed semi‐quantitatively. No pathological changes were found in the uterine samples of healthy dogs. In bitches with pyometra, the glandular epithelium expressed TLR 2 more intensely than the surface epithelium. The expression of TLR 2 in the glandular epithelium was also significantly higher in healthy dogs at oestrus, dioestrus and dogs with pyometra compared with anoestrous dogs (p < 0.01). The expression of TLR 2 in the stroma was not observed in the group of healthy dogs at all stages. The surface epithelium of cervix in dogs with pyometra expressed TLR 2 significantly more intensely than did the stoma, whereas the expression of TLR 2 during oestrus and dioestrus was absent in the stroma of cervix. This study provides the first report of immunohistochemical localization of TLR 2 in the canine reproductive tract. In the present study, TLR 2 was expressed in endometrial epithelium but was absent in the endometrial stroma of healthy dogs at all oestrous cycle stages. These findings suggest differential expression of TLR in endometrial cells. On the other hand, the lack of TLR 2 in the stroma of healthy uteri of dogs may predispose to infection from the invading pathogens once the epithelial cells have been destroyed by the pathogens, especially Gram‐positive bacteria.