Fernandes Claudia B, Loux Shavahn C, Scoggin Kirsten E, Squires Edward L, Troedsson Mats H, Esteller-Vico Alejandro, Ball Barry A
Reproduction Laboratory, Maxwell H. Gluck Equine Research, Department of Veterinary Science, University of Kentucky, Lexington KY40546-0099, USA; School of Veterinary Medicine and Animal Science, USP - University of São Paulo, Department of Animal Reproduction, São Paulo, SP, CEP: 05508-270, Brazil.
Reproduction Laboratory, Maxwell H. Gluck Equine Research, Department of Veterinary Science, University of Kentucky, Lexington KY40546-0099, USA.
Anim Reprod Sci. 2017 Dec;187:141-151. doi: 10.1016/j.anireprosci.2017.10.018. Epub 2017 Oct 31.
The cervix is a dynamic structure that undergoes dramatic changes during the estrous cycle, pregnancy and parturition. It is well established that hormonal changes, including estrogens, progestogens and prostaglandins, regulate the expression of key proteins involved in cervical function. The arachidonic acid cascade is important in the remodeling and relaxation of the cervix in the days preceding parturition. Despite the complexity of this mechanism, regulation of cervical function has received little study in the mare. Therefore, the objective of this study was to compare the expression of estrogen receptor α (ESR1) and β (ESR2), progesterone receptor (PGR), prostaglandin E2 type 2 (PTGER2) and type 4 (PTGER4) receptors as well as cyclooxygenase-1 (PTGS1) and -2 (PTGS2) in the equine cervical mucosa and stroma during estrus, diestrus and late pregnancy using qPCR. Immunohistochemistry was used to localize ESR1, ESR2, PGR, PTGER2 and PTGER4 receptors in these regions of the cervix. Relative mRNA expression of ESR1 and PGR was greater during estrus and diestrus than in late pregnancy in both the mucosa and stroma of the cervix. Expression of PTGER2 was highest in the cervical stroma during late pregnancy compared to either estrus or diestrus. Moreover, PTGS1 expression in mucosa and PTGS2 in stroma was greater during late pregnancy compared with estrus, but not diestrus. Immunostaining for ESR1, ESR2, PGR, PTGER2 and PTGER4 was consistently detected in the nucleus and cytoplasm of epithelium of the endocervix as well as the smooth muscle cytoplasm of the cervix in all stages evaluated. Immunolabeling in smooth muscle nuclei was detected for ESR1 and PGR in estrus, diestrus and late pregnancy, and for ESR2 in estrus and late pregnancy stages. The changes noted in late gestation likely reflect preparation of the equine cervix for subsequent parturition.
子宫颈是一个动态结构，在发情周期、妊娠和分娩期间会发生显著变化。众所周知，包括雌激素、孕激素和前列腺素在内的激素变化会调节参与子宫颈功能的关键蛋白质的表达。花生四烯酸级联反应在分娩前几天子宫颈的重塑和松弛过程中很重要。尽管该机制很复杂，但在母马中对子宫颈功能的调节研究较少。因此，本研究的目的是使用qPCR比较发情期、间情期和妊娠后期马子宫颈黏膜和基质中雌激素受体α（ESR1）和β（ESR2）、孕激素受体（PGR）、前列腺素E2 2型（PTGER2）和4型（PTGER4）受体以及环氧化酶-1（PTGS1）和-2（PTGS2）的表达。免疫组织化学用于在子宫颈的这些区域定位ESR1、ESR2、PGR、PTGER2和PTGER4受体。子宫颈黏膜和基质中ESR1和PGR的相对mRNA表达在发情期和间情期高于妊娠后期。与发情期或间情期相比，妊娠后期子宫颈基质中PTGER2的表达最高。此外，与发情期相比，妊娠后期黏膜中的PTGS1表达和基质中的PTGS2表达更高，但与间情期相比无差异。在所有评估阶段，在内子宫颈上皮细胞核和细胞质以及子宫颈平滑肌细胞质中均持续检测到ESR1、ESR2、PGR、PTGER2和PTGER4的免疫染色。在发情期、间情期和妊娠后期的平滑肌细胞核中检测到ESR1和PGR的免疫标记，在发情期和妊娠后期阶段检测到ESR2的免疫标记。妊娠后期观察到的变化可能反映了马子宫颈为随后分娩所做的准备。
