Silva E S M, Scoggin K E, Canisso I F, Troedsson M H T, Squires E L, Ball B A
Faculdade de Medicina Veterinária e Zootecnia, UNESP-Universidade Estadual Paulista, Departamento de Reprodução Animal e Radiologia Veterinária, Botucatu, São Paulo, CEP: 18618-970, Brazil.
Reproduction Laboratory, Maxwell H. Gluck Equine Research, Department of Veterinary Science, University of Kentucky, Lexington KY 40546-0099, USA.
Anim Reprod Sci. 2014 Dec 30;151(3-4):169-81. doi: 10.1016/j.anireprosci.2014.11.001. Epub 2014 Nov 10.
The objective of this study was to compare expression of estrogen receptor alpha (ER-α), β (ER-β), progesterone receptor (PR), as well as prostaglandin E2 type 2 (EP2) and 4 (EP4) receptors in the equine myometrium and endometrium during estrus, diestrus and early pregnancy. Tissues were collected during estrus, diestrus, and early pregnancy. Transcripts for ER-α (ESR1), ER-β (ESR2), PR (PGR), EP2 (PTGER2) and EP4 (PTGER4) were quantified by qPCR. Immunohistochemistry was used to localize ER-α, ER-β, PR, EP2 and EP4. Differences in transcript in endometrium and myometrium were compared by the ΔΔCT method. Expression for ESR1 (P<0.05) tended to be higher during estrus than diestrus in the endometrium (P=0.1) and myometrium (P=0.06). In addition, ESR1 expression was greater during estrus than pregnancy (P<0.05) in the endometrium and tended to be higher in estrus compared to pregnancy in the myometrium (P=0.1). Expression for PGR was greater (P<0.05) in the endometrium during estrus and diestrus than during pregnancy. In the myometrium, PGR expression was greater in estrus than pregnancy (P=0.05) and tended to be higher during diestrus in relation to pregnancy (P=0.07). There were no differences among reproductive stages in ESR2, PTGER2 and PTGER4 mRNA expression (P>0.05). Immunolabeling in the endometrium appeared to be more intense for ER-α during estrus than diestrus and pregnancy. In addition, immunostaining for PR during pregnancy appeared to be more intense in the stroma and less intense in glands and epithelium compared to estrus and diestrus. EP2 immunoreactivity appeared to be more intense during early pregnancy in both endometrium and myometrium, whereas weak immunolabeling for EP4 was noted across reproductive stages. This study demonstrates differential regulation of estrogen receptor (ER) and PR in the myometrium and endometrium during the reproductive cycle and pregnancy as well as abundant protein expression of EP2 in the endometrium and myometrium during early pregnancy in mares.
本研究的目的是比较发情期、黄体期和妊娠早期马子宫肌层和子宫内膜中雌激素受体α（ER-α）、β（ER-β）、孕激素受体（PR）以及前列腺素E2 2型（EP2）和4型（EP4）受体的表达。在发情期、黄体期和妊娠早期采集组织。通过qPCR对ER-α（ESR1）、ER-β（ESR2）、PR（PGR）、EP2（PTGER2）和EP4（PTGER4）的转录本进行定量。采用免疫组织化学法对ER-α、ER-β、PR、EP2和EP4进行定位。采用ΔΔCT法比较子宫内膜和子宫肌层转录本的差异。子宫内膜和子宫肌层中ESR1的表达在发情期高于黄体期（子宫内膜P=0.1，子宫肌层P=0.06），差异有统计学意义（P<0.05）。此外，子宫内膜中ESR1的表达在发情期高于妊娠期（P<0.05），子宫肌层中发情期的ESR1表达也倾向于高于妊娠期（P=0.1）。子宫内膜中PGR的表达在发情期和黄体期高于妊娠期（P<0.05）。在子宫肌层中，PGR的表达在发情期高于妊娠期（P=0.05），黄体期相对于妊娠期也倾向于更高（P=0.07）。ESR2、PTGER2和PTGER4 mRNA表达在不同生殖阶段无差异（P>0.05）。子宫内膜中ER-α的免疫标记在发情期比黄体期和妊娠期更强。此外，与发情期和黄体期相比，妊娠期PR在基质中的免疫染色更强，在腺体和上皮中的免疫染色更弱。EP2免疫反应性在妊娠早期的子宫内膜和子宫肌层中似乎更强，而在整个生殖阶段EP4的免疫标记较弱。本研究表明，在生殖周期和妊娠期间，子宫肌层和子宫内膜中雌激素受体（ER）和PR存在差异调节，并且在妊娠早期母马的子宫内膜和子宫肌层中EP2有丰富的蛋白表达。
