Institute of Veterinary AnatomyVetsuisse Faculty, University of Zurich, Zurich, Switzerland.
Department of Obstetrics and GynecologyFaculty of Veterinary Medicine, Near East University, Nicosia, North Cyprus, Turkey.
Reproduction. 2018 May;155(5):403-421. doi: 10.1530/REP-17-0761. Epub 2018 Feb 9.
For many years, modifications of the uterine extracellular matrix (ECM) during gestation have not been considered as critical for successful canine () pregnancy. However, previous reports indicated an effect of free-floating blastocysts on the composition of the uterine ECM. Here, the expression of selected genes involved in structural functions, cell-to-cell communication and inhibition of matrix metalloproteinases were targeted utilizing qPCR and immunohistochemistry. We found that canine free-floating embryos affect gene expression of , and This seems to be associated with modulation of trophoblast invasion, and proliferative and adhesive functions of the uterus. Although not modulated at the beginning of pregnancy, the decrease of structural ECM components (i.e. , , and ) from pre-implantation toward post-implantation at placentation sites appears to be associated with softening of the tissue in preparation for trophoblast invasion. The further decrease of these components at placentation sites at the time of prepartum luteolysis seems to be associated with preparation for the release of fetal membranes. Reflecting a high degree of communication, intercellular cell adhesion molecules are induced following placentation () or increase gradually toward prepartum luteolysis (). The spatio-temporal expression of TIMPs suggests their active involvement in modulating fetal invasiveness, and together with , they appear to protect deeper endometrial structures from trophoblast invasion. With this, the dog appears to be an interesting model for investigating placental functions in other species, e.g. in humans in which appears to share several similarities with canine subinvolution of placental sites (SIPS). In summary, the canine uterine ECM is only moderately modified in early pregnancy, but undergoes vigorous reorganization processes in the uterus and placenta following implantation.
多年来，妊娠期间子宫细胞外基质（ECM）的改变并未被认为对犬类成功妊娠至关重要。然而，之前的报告表明游离胚泡对子宫 ECM 组成有影响。在这里，利用 qPCR 和免疫组织化学技术靶向研究了参与结构功能、细胞间通讯和基质金属蛋白酶抑制的选定基因的表达。我们发现犬类游离胚胎影响 、 和 的基因表达。这似乎与滋养层侵袭的调节以及子宫的增殖和黏附功能有关。尽管在妊娠开始时没有调节，但从着床前到着床时 ECM 结构成分（即 、 、 和 ）在胎盘部位的减少似乎与组织软化以准备滋养层侵袭有关。在产前黄体溶解时，这些成分在胎盘部位的进一步减少似乎与胎膜释放的准备有关。细胞间黏附分子在胎盘形成后（）或在产前黄体溶解前逐渐增加（）诱导，反映出高度的通讯。TIMP 的时空表达表明它们积极参与调节胎儿的侵袭性，并且与 一起，它们似乎保护深层子宫内膜结构免受滋养层的侵袭。因此，狗似乎是研究其他物种胎盘功能的有趣模型，例如在人类中， 似乎与犬类胎盘部位的亚退化（SIPS）有几个相似之处。总之，在妊娠早期，犬类子宫 ECM 仅适度改变，但在着床后子宫和胎盘内发生剧烈的重组过程。
