ERα-dependent stimulation of LCN2 in uterine epithelium during mouse early pregnancy

Abstract

Maintenance of a suitable uterine milieu is important for embryo development and subsequent implantation during early pregnancy. High estrogen level in proestrous and estrous stages is essential for uterine anti-bacterial activity during preimplantation period. Lipocalin-2 is an essential molecule which prevents bacterial infection by sequestering iron. In this study, the highest expression of lipocalin-2 is observed in the endometrial epithelium on day 1 of normal pregnancy and pseudopregnancy, which exhibit a similar hormone scenario. By injecting the agonists for estrogen receptor α and estrogen receptor β in ovariectomized mice, we found estrogen receptor α is the dominant member for estrogen regulation on lipocalin-2 expression. Estrogen treatment in estrogen receptor α-knockout mice further confirmed the role of estrogen receptor α. Using published data from whole-genome estrogen receptor α binding site assay, significant estrogen receptor α recruitment peaks are found at the downstream of lipocalin-2 gene after estrogen treatment. Furthermore, to study the anti-bacterial activity of lipocalin-2 in uterus, Escherichia coli is injected to mimic bacterial infection. Our results showed an obvious induction of lipocalin-2 in Escherichia coli-treated group. Taken together, this study indicates estrogen regulation of lipocalin-2 in uterine epithelium is mediated by estrogen receptor α, and lipocalin-2 may have anti-bacterial activity during early pregnancy.

IHH, SHH, and primary cilia mediate epithelial-stromal cross-talk during decidualization in mice

“…Estradiol-17β (0.1, 1, and 10 μg/100 μl per mouse), ERα agonist PPT (250 ng/100 μl per mouse; Merck, H6036), and ERβ agonist DPN (100 ng/100 μl per mouse; Merck, H5915) were subcutaneously injected for 12 hours. Mice were euthanized at the indicated time for further analysis ( 87 ). Ovariectomized mice were also subcutaneously injected with progesterone (1 mg/100 μl) for 1 hour for SHH detection.…”

“…Western blot was carried out as previously stated ( 87 ). After being blocked with 5% nonfat milk (A600669, Sangon, China) for 1 hour, membranes were incubated with specific primary antibodies overnight at 4°C.…”

Primary Cilia Restrain PI3K-AKT Signaling to Orchestrate Human Decidualization

“…Immunofluorescence was performed with modifications according to a previous study [ 70 ]. In brief, the uterine paraffin sections were dewaxed and dehydrated.…”

The gonadal expression pattern of lipocalin‑2 and 24p3 receptor is modified in the gonads of the offspring of obese rats

“…For example, circulating concentrations of lcn2 are higher in women with gestational diabetes and preeclampsia, which suggests that lcn2 may be of value as a possible marker of fetal programming in humans (25). other studies conducted in humans and animal models indicated a sex specific regulation of Lcn2 by estrogen (26)(27)(28); ovariectomized mice treated with estrogen showed an increase in Lcn2 gene expression levels in white adipose tissue, liver and serum (29). This adipokine is a member of the lipocalin superfamily, characterized by the presence of three conserved motifs comprising a single eight-stranded antiparallel β-barrel similar to a calyx that is able to bind numerous ligands.…”

“…Semi-quantitative reverse transcription PCR. Total rna from all samples was reverse transcribed using the Superscript™ First-Strand Synthesis system (invitrogen; Thermo Fisher Scientific, Inc.), according to manufacturer's protocol and as described previously (28). all reactions were carried out in a total volume of 20 µl.…”