Expression and regulation of prostaglandin transporters, ATP-binding cassette, subfamily C, member 1 and 9, and solute carrier organic anion transporter family, member 2A1 and 5A1 in the uterine endometrium during the estrous cycle and pregnancy in pigs

Rapid generation of functional nanovesicles from human trophectodermal cells for embryo attachment and outgrowth

Extracellular vesicles (EVs) are important mediators of embryo attachment and outgrowth critical for successful implantation. While EVs have garnered immense interest in their therapeutic potential in assisted reproductive technology by improving implantation success, their large-scale generation remains a major challenge. Here, we report a rapid and scalable production of nanovesicles (NVs) directly from human trophectoderm cells (hTSCs) via serial mechanical extrusion of cells; these NVs can be generated in approximately 6 h with a 20-fold higher yield than EVs isolated from culture medium of the same number of cells. NVs display similar biophysical traits (morphologically intact, spherical, 90-130 nm) to EVs, and are laden with hallmark players of implantation that include cell-matrix adhesion and extracellular matrix organisation proteins (ITGA2/V, ITGB1, MFGE8) and antioxidative regulators (PRDX1, SOD2). Functionally, NVs are readily taken up by low-receptive endometrial HEC1A cells and reprogram their proteome towards a receptive phenotype that support hTSC spheroid attachment. Moreover, a single dose treatment with NVs significantly enhanced adhesion and spreading of mouse embryo trophoblast on fibronectin matrix. Thus, we demonstrate the functional potential of NVs in enhancing embryo implantation and highlight their rapid and scalable generation, amenable to clinical utility.

Sex-specific changes in protein expression of membrane transporters in the brain cortex of 5xFAD mouse model of Alzheimer's disease

Membrane transporters playing an important role in the passage of drugs, metabolites and nutrients across the membranes of the brain cells have been shown to be involved in pathogenesis of Alzheimer's disease (AD). However, little is known about sex-specific changes in transporter protein expression at the brain in AD. Here, we investigated sex-specific alterations in protein expression of three ATP-binding cassette (ABC) and five solute carriers (SLC) transporters in the prefrontal cortex of a commonly used model of familial AD (FAD), 5xFAD mice. Sensitive liquid chromatography tandem mass spectrometry-based quantitative targeted absolute proteomic analysis was applied for absolute quantification of transporter protein expression. We compared the changes in transporter protein expressions in 7-month-old male and female 5xFAD mice versus sex-matched wild-type mice. The study revealed a significant sex-specific increase in protein expression of ABCC1 (p = 0.007) only in male 5xFAD mice as compared to sex-matched wild-type animals. In addition, the increased protein expression of glucose transporter 1 (p = 0.01), 4F2 cell-surface antigen heavy chain (p = 0.01) and long-chain fatty acid transport protein 1 (p = 0.02) were found only in female 5xFAD mice as compared to sex-matched wild-type animals. Finally, protein expression of alanine/serine/cysteine/threonine transporter 1 was upregulated in both male (p = 0.02) and female (p = 0.002) 5xFAD mice. The study provides important information about sex-specific changes in brain cortical transporter expression in 5xFAD mice, which will facilitate drug development of therapeutic strategies for AD targeting these transporters and drug delivery research.

Identification and validation of SLCO4C1 as a biological marker in hepatocellular carcinoma based on anoikis classification features

BACKGROUND

Hepatocellular carcinoma (HCC) exhibits a high degree of invasiveness and is closely associated with rapid disease progression. Multiple lines of evidence indicate a strong correlation between anoikis resistance and tumor progression, invasion, and metastasis. Nevertheless, the classification of anoikis in HCC and the investigation of novel biological target mechanisms in this context continue to pose challenges, requiring further exploration.

METHODS

Combined with HCC samples from TCGA, GEO and ICGC databases, cluster analysis was conducted on anoikis genes, revealing novel patterns among different subtypes. Significant gene analysis of different gene subtypes was performed using WCGNA. The anoikis prognostic risk model was established by Lasso-Cox. Go, KEGG, and GSEA were applied to investigate pathway enrichment primarily observed in risk groups. We compared the disparities in immune infiltration, TMB, tumor microenvironment (TME), and drug sensitivity between the two risk groups. RT-qPCR and Western blotting were performed to validate the expression levels of SLCO4C1 in HCC. The biological functions of SLCO4C1 in HCC cells were assessed through various experiments, including CCK8 assay, colony formation assay, invasion migration assay, wound healing assay, and flow cytometry analysis.

RESULTS

HCC was divided into 2 anoikis subtypes, and the subtypeB had a better prognosis. An anoikis prognostic model based on 12 (COPZ2, ACTG2, IFI27, SPP1, EPO, SLCO4C1, RAB26, STC2, RAC3, NQO1, MYCN, HSPA1B) risk genes is important for survival and prognosis. Significant differences were observed in immune cell infiltration, TME, and drug sensitivity analysis between the risk groups. SLCO4C1 was downregulated in HCC. SLCO4C1 downregulation promoted the proliferation, invasion, migration, and apoptosis of HCC cells. The tumor-suppressive role of SLCO4C1 in HCC has been confirmed.

CONCLUSIONS

Our study presents a novel anoikis classification method for HCC that reveals the association between anoikis features and HCC. The anoikis feature is a critical biomarker bridging tumor cell death and tumor immunity. In this study, we provided the first evidence of SLCO4C1 functioning as a tumor suppressor in HCC.

Novel insights into conceptus-maternal signaling during pregnancy establishment in pigs

Pregnancy establishment in mammals, including pigs, requires coordinated communication between developing conceptuses (embryos with associated membranes) and the maternal organism. Porcine conceptuses signalize their presence by secreting multiple factors, of which estradiol-17β (E2) is considered the major embryonic signal initiating the maternal recognition of pregnancy. During this time, a limited supply of prostaglandin (PGF2α) to the corpora lutea and an increased secretion of luteoprotective factors (e.g., E2 and prostaglandin E2 [PGE2]) lead to the corpus luteum's maintained function of secreting progesterone, which in turn primes the uterus for implantation. Further, embryo implantation is related to establishing an appropriate proinflammatory environment coordinated by the secretion of proinflammatory mediators including cytokines, growth factors, and lipid mediators of both endometrial and conceptus origin. The novel, dual role of PGF2α has been underlined. Recent studies involving high-throughput technologies and sophisticated experimental models identified a number of novel factors and revealed complex relationships between these factors and those already established. Hence, it seems that early pregnancy should be regarded as a sequence of processes orchestrated by pleiotropic factors that are involved in redundancy and compensatory mechanisms that preserve the essential functions critical for implantation and placenta formation. Therefore, establishing the hierarchy between all molecules present at the embryo-maternal interface is now even more challenging.

Serum progesterone and oxytocinase, and endometrial and luteal gene expression in pregnant, nonpregnant, oxytocin, carbetocin and meclofenamic acid treated mares

Our objectives were to examine changes in endometrial and luteal gene expression during estrus, diestrus, pregnancy and treatments to induce luteolysis and putatively induce luteostasis. Groups were: Diestrus (DIEST), Estrus (ESTR), Pregnant (PREG), Oxytocin (OXY), Carbetocin (CARB), and Meclofenamic acid (MFA). Blood was obtained from day (D)12 to D15 for measurement of oxytocinase, also referred to as leucyl-cysteinyl aminopeptidase (LNPEP) and progesterone. Luteal biopsies were obtained on D12 and D15 and an endometrial biopsy on D15. Real-time RT-PCR was performed for the following genes: PGR, ESR1, OXTR,OXT, LNPEP, PTGS2, PTGFR, PLA2G2C, PTGES, SLC2A4, and SLC2A1. Regarding serum LNPEP, PREG and OXY (p-value<0.001) had higher concentrations than DIEST mares. Endometrial PTGES expression was higher (p-value <0.04) in DIEST, PREG and OXY than other groups. Endometrium from ESTR had increased expression of OXT (p-value < 0.02) compared to MFA and OXY mares. Carbetocin treatment: decreased serum progesterone and LNPEP; increased endometrial PLA2G2C; decreased endometrial PTGES; and decreased luteal aromatase and PTGES. Treatment with MFA: decreased endometrial PLA2G2C, increased endometrial PTGES; and resulted in less OXTR and OXT luteal abundance on D12 compared to D15. Endometrial and luteal expression of LNPEP is affected by physiologic stage and treatment and is involved in luteal function and pregnancy recognition pathways through effects on oxytocin and prostaglandin synthesis in the horse.

Expression profile of genes related to pregnancy maintenance in Dromedary Camel during the first trimester

So far, few signals involved in embryo-maternal dialogue have been identified in pregnant she-camel. Our objective was to investigate expression profiles of genes relevant to uterine extracellular matrix remodeling (ITGB4, SLCO2A1, FOS, and JUN), uterine tissue vascularization, and placental formation (VEGFA, PGF, and PDGFA), embryonic growth and development (IGF1 and PTEN), plus cell death of uterine tissue (BCL2) in early pregnant versus non-pregnant she-camels. Forty genital tracts (20 pregnant and 20 non-pregnant) and blood samples were collected from abattoirs. Total RNA was extracted from uterine tissues and qRT-PCR was conducted for candidate genes. Serum concentrations of progesterone (P4) and estradiol17-β (E2) were measured. Expression of ITGB4, FOS, and PGF genes increased (P < 0.001) in the right uterine horn of pregnant versus non-pregnant she-camels. Moreover, JUN, SLCO2A1, VEGFA, and PTEN mRNAs were up-regulated (P < 0.001) in various segments of uterine tissues in pregnant groups. The PDGFA transcript was over-expressed (P < 0.001) in both uterine horns of pregnant groups. Additionally, IGF1 was higher (P < 0.001) in the right horn and the uterine body of pregnant groups, and expression of BCL2 was increased (P < 0.001) in the pregnant uterine body. Moreover, serum concentrations of P4 were higher (P < 0.001) and E2 lower (P < 0.05) in pregnant she-camels. Taken together, the fine-tuning of genes related to implantation, matrix formation, vascularization, and placental formation is highly required for successful pregnancy in she-camels.

Expression of Oxytocin/Neurophysin I and Oxytocinase in the Equine Conceptus from Day 8 to Day 21 Post-Ovulation

Leucyl and cystinyl aminopeptidase (LNPEP/oxytocinase) is an enzyme that metabolizes oxytocin in serum and tissues. The presence of oxytocin/neurophysin I (OXT), oxytocin and LNPEP and their relationship to other genes is unknown in the equine conceptus. Our objective was to characterize gene expression of LNPEP and OXT on D8, 10, 12, 14, 15, 16 and 21 conceptuses in relationship to other genes. Immunohistochemistry, western blot and liquid chromatography with tandem mass spectrometry (LC-MS/MS) were used for identification of oxytocin and LNPEP in D15, 16 and 18 conceptuses. LNPEP was increased at D15 compared to D10, was immunolocalized in the equine trophectoderm and endoderm, and protein was confirmed by LC-MS/MS. Maximal abundance of OXT was at D21, and lowest on D12 and D14, but no protein was identified. OXTR abundance was highest on D14 and D21. LNPEP was correlated with PTGFR and PTGES on D12 and D14-D15, and high expression of PTGES, PTGS2 was found on D14, D15 and D21; PTGFR was found on D8 and D12-21. LNPEP may have a role in prostaglandin regulation and conceptus fixation by decreasing the availability of oxytocin. Further investigation on the role embryonic LNPEP during pregnancy is warranted.

Spatiotemporal endometrial transcriptome analysis revealed the luminal epithelium as key player during initial maternal recognition of pregnancy in the mare

During the period of maternal recognition of pregnancy (MRP) in the mare, the embryo needs to signal its presence to the endometrium to prevent regression of the corpus luteum and prepare for establishment of pregnancy. This is achieved by mechanical stimuli and release of various signaling molecules by the equine embryo while migrating through the uterus. We hypothesized that embryo's signals induce changes in the endometrial gene expression in a highly cell type-specific manner. A spatiotemporal transcriptomics approach was applied combining laser capture microdissection and low-input-RNA sequencing of luminal and glandular epithelium (LE, GE), and stroma of biopsy samples collected from days 10-13 of pregnancy and the estrous cycle. Two comparisons were performed, samples derived from pregnancies with conceptuses ≥ 8 mm in diameter (comparison 1) and conceptuses ≤ 8 mm (comparison 2) versus samples from cyclic controls. The majority of gene expression changes was identified in LE and much lower numbers of differentially expressed genes (DEGs) in GE and stroma. While 1253 DEGs were found for LE in comparison 1, only 248 were found in comparison 2. Data mining mainly focused on DEGs in LE and revealed regulation of genes related to prostaglandin transport, metabolism, and signaling, as well as transcription factor families that could be involved in MRP. In comparison to other mammalian species, differences in regulation of genes involved in epithelial barrier formation and conceptus attachment and implantation reflected the unique features of equine reproduction at the time of MRP at the molecular level.

Uterine cellular changes during mammalian pregnancy and the evolution of placentation

There are many different forms of nutrient provision in viviparous (live bearing) species. The formation of a placenta is one method where the placenta functions to transfer nutrients from mother to fetus (placentotrophy), transfer waste from the fetus to the mother and respiratory gas exchange. Despite having the same overarching function, there are different types of placentation within placentotrophic vertebrates, and many morphological changes occur in the uterus during pregnancy to facilitate formation of the placenta. These changes are regulated in complex ways but are controlled by similar hormonal mechanisms across species. This review describes current knowledge of the morphological and molecular changes to the uterine epithelium preceding implantation among mammals. Our aim is to identify the commonalities and constraints of these cellular changes to understand the evolution of placentation in mammals and propose directions for future research. We compare and discuss the complex modifications to the ultrastructure of uterine epithelial cells and show that there are similarities in the changes to the cytoskeleton and gross morphology of the uterine epithelial cells, especially of the apical and lateral plasma membrane of the cells during the formation of a placenta in all eutherians and marsupials studied to date. We conclude that further research is needed to understand the evolution of placentation among viviparous mammals, particularly concerning the level of placental invasiveness, hormonal control and genetic underpinnings of pregnancy in marsupial taxa.

Uterine epithelial expression of the tumor necrosis factor superfamily: a strategy for immune privilege during pregnancy in a true epitheliochorial placentation species

The maternal immune system tolerates semi-allogeneic placental tissues during pregnancy. Fas ligand (FASLG) and tumor necrosis factor superfamily 10 (TNFSF10) are known to be components of maternal immune tolerance in humans and mice. However, the role of FASLG and TNFSF10 in the tolerance process has not been studied in pigs, which form a true epitheliochorial type placenta. Thus, the present study examined the expression and function of FASLG and TNFSF10 and their receptors at the maternal-conceptus interface in pigs. The endometrium and conceptus tissues expressed FASLG and TNFSF10 and their receptor mRNAs during pregnancy in a stage-specific manner. During pregnancy, FASLG and TNFSF10 proteins were localized predominantly to endometrial luminal epithelial cells with strong signals on Day 30 to term and on Day 15, respectively, and receptors for TNFSF10 were localized to some stromal cells. Interferon-γ (IFNG) increased the expression of TNFSF10 and FAS in endometrial tissues. Co-culture of porcine endometrial epithelial cells over-expressing TNFSF10 with peripheral blood mononuclear cells yielded increased apoptotic cell death of lymphocytes and myeloid cells. In addition, many apoptotic T cells were found in the endometrium on Day 15 of pregnancy. The present study demonstrated that FASLG and TNFSF10 were expressed at the maternal-conceptus interface and conceptus-derived IFNG increased endometrial epithelial TNFSF10, which, in turn, induced apoptotic cell death of immune cells. These results suggest that endometrial epithelial FASLG and TNFSF10 may be critical for the formation of micro-environmental immune privilege at the maternal-conceptus interface for the establishment and maintenance of pregnancy in pigs.

Positive selection signatures in Anqing six-end-white pig population based on reduced-representation genome sequencing data

Anqing six-end-white (AQ) pig performs well on resistance to coarse fodder and disease, reproduction and meat quality, offering high potential for exploitation. Environmental conditions and strict selections from local farmers have cultivated the AQ pig to be an outstanding and unique local pig breed. Thus we aim to detect genetic positive selection signatures within the AQ pig population to explore underlying genetic mechanisms. A relative extended haplotype homozygosity (REHH) test was performed in the population of 79 AQ pigs to seek evidence demonstrating that selective actions have left an imprint on the whole genome. In total, 430 500 REHH tests were performed on 53 067 core regions with average REHH tests of 8.11, average lengths of 11.50 kb and an overall length of 610.38 Mb which accounted for 26.94% of the whole genome. Finally, a total of 1819 core haplotypes (P < 0.01) and 586 candidate genes were obtained. These genes were mainly related to meat quality (MYOG, SNX19), resistance to disease (CRISPLD2, CD14) and reproduction traits (ERBB2, NRP2). A panel of genes within the 30 top significant REHH tests was mainly categorized to traits of meat quality and disease resistance. Among 13 KEGG pathways, MAPK, GnRH and Oxytocin signaling pathways, associated with the biological processes of crucial economic traits, were noteworthy. The excellent characteristics of the AQ pig benefited from the combination of natural and human factors. We provide a sketch map that shows the distribution of selection footprints on the whole genome of AQ pig and found potential genes for future studies.

Knockdown of SLCO4C1 inhibits cell proliferation and metastasis in endometrial cancer through inactivating the PI3K/Akt signaling pathway

Endometrial cancer (EC) is the second leading type of cancer among women, and its progression is dependent on several factors. The aim of the present study was to examine the effect of solute carrier organic anion transporter family member 4C1 (SLCO4C1) on human EC and determine the underlying molecular mechanism. A total of 57 differentially expressed genes associated with advanced stage and survival were identified in The Cancer Genome Atlas database. In addition, gene ontology analysis indicated that SLCO4C1 was highly expressed in cell differentiation and integral component of plasma membrane. High SLCO4C1 expression in EC tissues was verified by immunohistochemistry. The results demonstrated that the downregulation of SLCO4C1 could significantly suppress the viability, sphere formation, migration and invasion abilities of cells, but enhance apoptosis in EC cell lines. Furthermore, the present results demonstrated that SLCO4C1 had effects on the epithelial-mesenchymal transition (EMT) phenotype in EC cells and regulated the expression of EMT-related proteins. Mechanistically, the present study revealed that SLCO4C1 regulated the biological functions of EC cells by inactivating the PI3K/Akt signaling pathway. Collectively, it was demonstrated that the SLCO4C1/PI3K/Akt pathway may play an important role in EC progression and metastasis and serve as a potential biomarker and target for EC diagnosis and treatment.

Cell type-specific endometrial transcriptome changes during initial recognition of pregnancy in the mare

Previous endometrial gene expression studies during the time of conceptus migration did not provide final conclusions on the mechanisms of maternal recognition of pregnancy (MRP) in the mare. This called for a cell type-specific endometrial gene expression analysis in response to embryo signals to improve the understanding of gene expression regulation in the context of MRP. Laser capture microdissection was used to collect luminal epithelium (LE), glandular epithelium and stroma from endometrial biopsies from Day 12 of pregnancy and Day 12 of the oestrous cycle. RNA sequencing (RNA-Seq) showed greater expression differences between cell types than between pregnant and cyclic states; differences between the pregnant and cyclic states were mainly found in LE. Comparison with a previous RNA-Seq dataset for whole biopsy samples revealed the specific origin of gene expression differences. Furthermore, genes specifically differentially expressed (DE) in one cell type were found that were not detectable as DE in biopsies. Overall, this study revealed spatial information about endometrial gene expression during the phase of initial MRP. The conceptus induced changes in the expression of genes involved in blood vessel development, specific spatial regulation of the immune system, growth factors, regulation of prostaglandin synthesis, transport prostaglandin receptors, specifically prostaglandin F receptor (PTGFR) in the context of prevention of luteolysis.

Analysis of interferon-γ receptor IFNGR1 and IFNGR2 expression and regulation at the maternal-conceptus interface and the role of interferon-γ on endometrial expression of interferon signaling molecules during early pregnancy in pigs

It has long been known that pig conceptuses produce interferon-γ (IFNG) at the time of implantation, but the role of IFNG and its mechanism of action at the maternal-conceptus interface are not fully understood. Accordingly, we analyzed the expression and regulation of IFNG receptors IFNGR1 and IFNGR2 in the endometrium during the estrous cycle and pregnancy in pigs. Levels of IFNGR1 and IFNGR2 messenger RNA (mRNA) expression changed in the endometrium, with the highest levels during mid pregnancy for IFNGR1 and on Day 12 of pregnancy for IFNGR2. The expression of IFNGR1 and IFNGR2 mRNAs was also detected in conceptuses during early pregnancy and chorioallantoic tissues during mid to late pregnancy. IFNGR1 and IFNGR2 mRNAs were localized to endometrial epithelial and stromal cells and to the chorionic membrane during pregnancy. IFNGR2 protein was also localized to endometrial epithelial and stromal cells, and increased epithelial expression of IFNGR2 mRNA and protein was detectable during early pregnancy than the estrous cycle. Explant culture studies showed that estrogen increased levels of IFNGR2, but not IFNGR1, mRNAs, while interleukin-1β did not affect levels of IFNGR1 and IFNGR2 mRNAs. Furthermore, IFNG increased levels of IRF1, IRF2, STAT1, and STAT2 mRNAs in the endometrial explants. These results in pigs indicate that IFNGR1 and IFNGR2 are expressed in a stage of pregnancy- and cell-type specific manner in the endometrium and that sequential cooperative action of conceptus signals estrogen and IFNG may be critical for endometrial responsiveness to IFNs for the establishment of pregnancy in pigs.

Unique epithelial expression of S100A calcium binding protein A7A in the endometrium at conceptus implantation in pigs

Objective

S100A7A, a member of the S100 protein family, is involved in various biological processes, including innate immunity, antimicrobial function, and epithelial tumorigenesis. However, the expression and function of S100A7A in the endometrium during the estrous cycle and pregnancy are not well understood in pigs. Therefore, this study determined the expression and regulation of S100A7A at the maternal-conceptus interface in pigs.

Methods

We obtained endometrial tissues from pigs throughout the estrous cycle and pregnancy, conceptus tissues during early pregnancy, and chorioallantoic tissues during mid- to late pregnancy and analyzed the expression of S100A7A in these tissues. We also determined the effects of steroid hormones, estradiol-17β (E2) and progesterone, and interleukin-1β (IL1B) on S100A7A expression in endometrial tissues.

Results

We found that S100A7A was expressed in the endometrium during the estrous cycle and pregnancy in a pregnancy status- and stage-dependent manner and was localized to endometrial LE and superficial GE cells with strong intensity in LE cells on Day 12 of pregnancy. Early stage conceptuses and chorioallantoic tissues from Day 30 to term pregnancy also expressed S100A7A. The expression of S100A7A was increased by E2 and IL1B in endometrial tissues.

Conclusion

S100A7A was expressed at the maternal-conceptus interface at the initiation of implantation in response to conceptus-derived estrogen and IL1B and could be a unique endometrial epithelial marker for conceptus implantation in pigs. These findings provide an important insight into the understanding of conceptus-endometrial interactions for the successful establishment of pregnancy in pigs.

Leukemia inhibitory factor and its receptor: expression and regulation in the porcine endometrium throughout the estrous cycle and pregnancy

Objective

Leukemia inhibitory factor (LIF) binds to a heterodimeric receptor composed of LIF receptor (LIFR) and glycoprotein 130 (GP130) to transmit signals into the cell. LIF plays an important role in reproduction by regulating immune response, decidualization, and implantation in several species. However, the expression of LIF and LIFR in the endometrium throughout the estrous cycle and pregnancy in pigs is not fully understood.

Methods

We analyzed the expression of LIF and LIFR in the endometrium on days 0 (estrus), 3, 6, 9, 12, 15, and 18 of the estrous cycle, and days 12, 15, 30, 60, 90, and 114 of pregnancy, in conceptuses on days 12 and 15, and in chorioallantoic tissues on days 30, 60, 90, and 114 of pregnancy in pigs. We also determined the effects of estrogen and progesterone on the expression of LIF and LIFR in endometrial tissues.

Results

The expression of LIF increased in the endometrium during the late diestrus phase of the estrous cycle and during mid- to late- pregnancy, while the expression of LIFR increased during early pregnancy. The expression of LIF was induced by increasing doses of estrogen, whereas the expression of LIFR was induced by increasing doses of progesterone.

Conclusion

These results indicate that the expression of LIF and its receptor LIFR in the endometrium is regulated in a stage-specific manner during the estrous cycle and pregnancy, suggesting that LIF and its receptor signaling system may play critical roles in regulating endometrial function in pigs.

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

The establishment of pregnancy is a complex process that requires a well-coordinated interaction between the implanting conceptus and the maternal uterus. In pigs, the conceptus undergoes dramatic morphological and functional changes at the time of implantation and introduces various factors, including estrogens and cytokines, interleukin-1β2 (IL1B2), interferon-γ (IFNG), and IFN-δ (IFND), into the uterine lumen. In response to ovarian steroid hormones and conceptus-derived factors, the uterine endometrium becomes receptive to the implanting conceptus by changing its expression of cell adhesion molecules, secretory activity, and immune response. Conceptus-derived estrogens act as a signal for maternal recognition of pregnancy by changing the direction of prostaglandin (PG) F_2α from the uterine vasculature to the uterine lumen. Estrogens also induce the expression of many endometrial genes, including genes related to growth factors, the synthesis and transport of PGs, and immunity. IL1B2, a pro-inflammatory cytokine, is produced by the elongating conceptus. The direct effect of IL1B2 on endometrial function is not fully understood. IL1B activates the expression of endometrial genes, including the genes involved in IL1B signaling and PG synthesis and transport. In addition, estrogen or IL1B stimulates endometrial expression of IFN signaling molecules, suggesting that estrogen and IL1B act cooperatively in priming the endometrial function of conceptus-produced IFNG and IFND that, in turn, modulate endometrial immune response during early pregnancy. This review addresses information about maternal-conceptus interactions with respect to endometrial gene expression in response to conceptus-derived factors, focusing on the roles of estrogen and IL1B during early pregnancy in pigs.