Expression of Oestrogen Receptor α and Oestrogen Receptor β in the Uterus of the Pregnant Swine

Abstract

The uterus is a well-known target of endocrine, paracrine and autocrine acting molecules among which steroid hormones are of special importance. The objective of our work was to localize oestrogen receptors (ERα and ERβ) mRNA and protein in the pig uterus throughout pregnancy (10, 18, 32, 50, 71, 90 days post coitum) using RT-PCR, Western-blot and immunohistochemistry. The present study is the first one to demonstrate the presence of ERs protein in the porcine uterus not only at the beginning but also at mid- and late pregnancy. In the pregnant swine, ERα was immunolocalized in the luminal epithelium (LE) and glandular epithelium (GE) and the myometrium of the uterus with differences in the intensity of staining at different stages of pregnancy studied. The LE and GE of pregnant swine stained for ERβ regardless of the day of pregnancy examined, whereas only a few cells within the myometrium showed a weak immunoreactivity. Western blot analysis confirmed the presence of ERα and ERβ proteins on all investigated days of gestation. The expression of ERα and ERβ mRNA was detected by RT-PCR in all examined samples corresponding to each of the consecutive stages of pregnancy. The obtained results show that ERα is more abundant in comparison to ERβ within the porcine pregnant uterus. The presence of ERα and ERβ in all compartments of the pig uterus during pregnancy may indicate direct action of oestrogens on proliferation and differentiation of these cells.

Endometrial response to conceptus-derived estrogen and interleukin-1β at the time of implantation in pigs

“…On d 15, ESR1 staining decreases in LE and GE cells and then increases in LE and GE cells and the stroma on d 18 of the estrous cycle in cyclic pigs, but remains low after d 18 in pregnant pigs [ 37 ]. Estrogen receptor-β (ESR2), a subtype of nuclear estrogen receptors, is expressed in LE and GE cells in the endometrium during the estrous cycle and pregnancy and in conceptus trophectoderm on d 12 [ 38 ], but regulation and function of ESR2 is not fully understood in pigs [ 39 , 40 ]. The presence of the membrane-associated estrogen receptors including membrane-bound ESR1 and G-protein coupled estrogen receptor 1 (GPER1), which activate non-genomic actions of estrogen, has been described in various tissue and cell types in several species [ 41 , 42 ].…”

Integrated Analysis of miRNA-mRNA Network Reveals Different Regulatory Patterns in the Endometrium of Meishan and Duroc Sows during Mid-Late Gestation

“…Estradiol regulates expression of IHH in the mammalian uterus and plays a role in development of the placenta [68,69]. The effects of estradiol in the uterus are mediated by ESR1, which is the predominant type of estrogen receptor in the mature uterus [70,71]. Based on the results of the dual luciferase assay, ssc-miR-671-5p appears to downregulate the expression of ESR1 ( Figure 9B).…”

Transcriptome Analysis Revealed the Embryo-Induced Gene Expression Patterns in the Endometrium from Meishan and Yorkshire Pigs

“…TRIM16, also named estrogen-responsive B box protein and acts as a positive regulator of the CYP26A1 expression, showed a similar expression pattern with CYP26A1 gene in both Meishan and Yorkshire endometriums. The expression of ESR1 in the porcine endometrium may indicate direct action of estrogen on proliferation and differentiation of endometrial cells [ 40 ]. The estrogen and retinoic acid signaling pathway provides regulation of “Yin and Yang” in cell proliferation and survival [ 38 , 41 ].…”