Project description:Uterine glands are essential for pregnancy in mice and likely humans, because they secrete or transport bioactive substances that regulate uterine receptivity for blastocyst implantation. In mice, the uterus becomes receptive to blastocyst implantation on day 4, but is refractory by day 5. Here, blastocysts could be recovered from progesterone-induced uterine gland (PUGKO) but not wildtype (WT) mice on day 5 post-mating. Anti-adhesive Muc1 protein and microvilli were present on the luminal epithelium of PUGKO but not WT uteri. A number of known uterine receptivity genes and gland-specific genes were altered in the PUGKO uterus. Next, the uterus and uterine luminal fluid (ULF) were obtained from WT and PUGKO mice on day 3, 4 and 5. Transcriptome analysis revealed that 580 genes were decreased in the PUGKO uterus, however ULF secrotome analysis revealed that many proteins and several amino acids were increased in the PUGKO ULF. Of note, many proteins encoded by many gland-specific genes were not identified in the ULF of WT mice. These results support the ideas that uterine glands secrete factors that regulate ULF homeostasis and interact with other cell types in the uterus to influence uterine receptivity and blastocyst implantation for the establishment of pregnancy.
Project description:Embryo implantation is a complex process which involves biochemical and physiological interactions between an implantation-competent blastocyst and a receptive uterus. However, the exact biochemical changes of uterine fluid, uterus, and plasma during peri-implantation remain unclear. This study aims to characterize the biochemical and metabolic changes that occur during the peri-implantation period of early pregnancy, using mice as an animal model. Gas chromatography-mass spectrometry was used to analyze the metabolite profiles of the uterus, uterine fluid, and maternal plasma at pre-implantation and implantation. The multivariate analyses, ANOVA and Tukey's HSD test, were applied to detect significant changes in metabolites and metabolic pathways. The metabolic networks were reconstructed in silico based on the identified metabolites and KEGG metabolic framework. Between pre-implantation day 1 and day 4, dramatic metabolic changes were observed in the uterine fluid that could be important for blastocyst development and protection against the harsh uterine environment. Palmitoleic acid, fumaric acid, and glutaric acid changed levels at day 4 in the uterus, suggesting that they may be associated with endometrial receptivity. Both the uterus and maternal plasma showed profound changes in cellular metabolism at the early implantation period, including upregulation of branched-chain amino acids and intermediates of one-carbon metabolism, an upregulation of glyoxylate and dicarboxylate metabolism, and downregulation of aerobic respiration; all of which could be involved in the regulation of the maternal-fetal interface, alternative nutrient utilization, and energy preservation for implantation as well as later placentation and fetal development to ensure successful embryo implantation.
Project description:Uterine glands and, by inference, their secretions impact uterine receptivity, blastocyst implantation, stromal cell decidualization, and placental development. Changes in gland function across the menstrual cycle are impacted by steroid hormones, estrogen and progesterone, as well as stroma-derived factors. Using an endometrial epithelial organoid (EEO) system, transcriptome and proteome analyses identified distinct responses of the EEO to steroid hormones and prostaglandin E2 (PGE2). Notably, steroid hormones and PGE2 modulated the basolateral secretion of EEO proteins, where cystatin C (CST3) was significantly increased by progesterone and PGE2. CST3 treatment of decidualizing stromal cells significantly decreased the decidualization markers PRL and IGFBP1. The attenuation of stromal cell decidualization via CST3 suggests a role for uterine gland-derived proteins in controlling the extent of decidualization. These findings provide evidence that uterine gland-derived factors directly impact stromal cell decidualization, which has strong implications for better understanding pregnancy establishment and female fertility in humans.
Project description:The mammalian endometrium is covered by the luminal epithelium (Le), which directly interacts with the blastocyst and plays an important role in the establishment of reciprocal crosstalk between the embryo and receptive uterus during implantation. However, the effect of the blastocyst on uterine receptivity is far from well understood. Through transcriptomic profiling of the uterine Le isolated by laser capture microdissection, it was demonstrated that global gene expression changes occurred in Le between pseudopregnant mice without embryos and pregnant mice with embryos. Some differentially expressed genes, including upregulated Areg, Ihh, Lifr and downregulated Msx1, Pgr, Gata2, have been reported to regulate the establishment of uterine receptivity. Besides, we found that blastocysts induced an increase in both the number and acidification of lysosome, consistent with enhanced lysosomal hydrolase activity in uterine Le. Further exploration uncovered that blastocyst-derived IGF2 was involved into the activation of epithelial STAT3 to induce lysosomal hydrolase expression, and inhibition of lysosomal function derails normal uterine receptivity and embryo implantation. Finally, based on the proteomic data of both epithelia and the separated lysosome, it was revealed that CLDN1 and MUC1, two well-known downregulated molecules for successful implantation, are degraded by epithelial lysosome. In brief, our data demonstrated that blastocysts induced normal epithelium differentiation with lysosome activation to promote the establishment of uterine receptivity for embryo implantation.
Project description:The mammalian endometrium is covered by the luminal epithelium (Le), which directly interacts with the blastocyst and plays an important role in the establishment of reciprocal crosstalk between the embryo and receptive uterus during implantation. However, the effect of the blastocyst on uterine receptivity is far from well understood. Through transcriptomic profiling of the uterine Le isolated by laser capture microdissection, it was demonstrated that global gene expression changes occurred in Le between pseudopregnant mice without embryos and pregnant mice with embryos. Some differentially expressed genes, including upregulated Areg, Ihh, Lifr and downregulated Msx1, Pgr, Gata2, have been reported to regulate the establishment of uterine receptivity. Besides, we found that blastocysts induced an increase in both the number and acidification of lysosome, consistent with enhanced lysosomal hydrolase activity in uterine Le. Further exploration uncovered that blastocyst-derived IGF2 was involved into the activation of epithelial STAT3 to induce lysosomal hydrolase expression, and inhibition of lysosomal function derails normal uterine receptivity and embryo implantation. Finally, based on the proteomic data of both epithelia and the separated lysosome, it was revealed that CLDN1 and MUC1, two well-known downregulated molecules for successful implantation, are degraded by epithelial lysosome. In brief, our data demonstrated that blastocysts induced normal epithelium differentiation with lysosome activation to promote the establishment of uterine receptivity for embryo implantation.
Project description:We used the microarray analysis to determine the differential gene expression profiles in mouse uterine luminal epithelium between preimplantation gestation day 3.5 and postimplantation gestation day 4.5, and investigeate the molecular mechanism of the establishment of uterine receptivity and embryo implantation. Uterine luminal epithelium (LE) is critical for the establishment of uterine receptivity during embryo implantation. Many genes are known to have differential expression in the periimplantation LE but the global profiling of the altered genes in the periimplantation LE is unknown. To fill in this knowledge gap, microarray analysis was performed in gestation day 3.5 (D3.5, preimplantation) and D4.5 (postimplantation) mouse LE from natural pregnancy. There were 382 significantly upregulated and 245 significantly downregulated genes (>2 fold, P<0.05) in the D4.5 LE. There are 6 samples. 3 for gestation day 3.5 uterine luminal epithelium, the other 3 for gestation day 4.5 uterine luminal epithelium
Project description:Uterine glands and, by inference, their secretions impact uterine receptivity, blastocyst implantation, stromal cell decidualization, and placental development. Changes in gland function across the menstrual cycle are impacted by steroid hormones, estrogen and progesterone, as well as stroma-derived factors. Using an endometrial epithelial organoid (EEO) system, transcriptome and proteome analyses identified distinct responses of the EEO to steroid hormones and prostaglandin E2 (PGE2). Notably, steroid hormones and PGE2 modulated the basolateral secretion of EEO proteins, where cystatin C (CST3) was significantly increased by progesterone and PGE2. CST3 treatment of decidualizing stromal cells significantly decreased the decidualization markers PRL and IGFBP1. The attenuation of stromal cell decidualization via CST3 suggests a role for uterine gland-derived proteins in controlling the extent of decidualization. These findings provide evidence that uterine gland-derived factors directly impact stromal cell decidualization, which has strong implications for better understanding pregnancy establishment and female fertility in humans.
Project description:We used the microarray analysis to determine the differential gene expression profiles in mouse uterine luminal epithelium between preimplantation gestation day 3.5 and postimplantation gestation day 4.5, and investigeate the molecular mechanism of the establishment of uterine receptivity and embryo implantation. Uterine luminal epithelium (LE) is critical for the establishment of uterine receptivity during embryo implantation. Many genes are known to have differential expression in the periimplantation LE but the global profiling of the altered genes in the periimplantation LE is unknown. To fill in this knowledge gap, microarray analysis was performed in gestation day 3.5 (D3.5, preimplantation) and D4.5 (postimplantation) mouse LE from natural pregnancy. There were 382 significantly upregulated and 245 significantly downregulated genes (>2 fold, P<0.05) in the D4.5 LE.
Project description:Bone morphogenetic proteins (BMPs) are transforming growth factor β (TGFβ) family members that regulate the post-implantation and mid-gestation stages of pregnancy. In this study we discovered that signaling via activin-like kinase 3 (ALK3/BMPR1A), a BMP type 1 receptor, is necessary for blastocyst attachment. To understand the role of ALK3 in the luminal uterine epithelium, we obtained the gene expression profiles of isolated luminal uterine epithelium from 3.5dpc control and Alk3 cKO mice. Gene expression profiling of isolated luminal uterine epithelium from control and Alk3 cKO mice. two group comparison
Project description:Embryo implantation into a receptive endometrium is tightly regulated by a variety of maternal factors, including cytokines, growth factors and transcription factors. Previous studies identified the leukaemia inhibitory factor (LIF), produced in uterine glands, as an essential factor for implantation. It was shown that LIF acts via its cell surface receptor to activate the transcription factor STAT3 in the uterine epithelial cells. However, the mechanisms via which STAT3 promotes uterine receptivity remain unknown. To address the molecular pathways regulated by STAT3 in the uterus, we created mice in which Stat3 gene is conditionally inactivated in uterine epithelium. These mutant mice are infertile due to implantation failure and exhibit a lack of embryo attachment to the luminal epithelium. Gene expression profiling of the epithelial tissue impaired in STAT3 activation revealed dysregulated expression of specific components of junctional complexes, including E-cadherin, M-NM-2-catenin, and claudins, which critically regulate epithelial cell polarity and embryo attachment. Additionally, mice lacking functional epithelial STAT3 showed markedly reduced stromal proliferation and differentiation, indicating that this transcription factor controls stromal function via a paracrine mechanism. The stromal defect arose from a drastic reduction in the production of several members of the epidermal growth factor (EGF) family in luminal epithelium of mutant uteri and consequent lack of activation of EGF receptor signaling and mitotic activity in the stromal cells. Collectively, our results uncovered intricate signaling networks operating downstream of STAT3 in uterine epithelium that regulate epithelial cell polarity, and stromal proliferation and differentiation, which are critical determinants of successful implantation. To identify the downstream targets of STAT3 in mouse uterine epithelial cells during pregnancy, we performed gene expression profling of mouse uterine epithelial cells on day 4 of pregnancy between Stat3 flox control and SW d/d mice. This led to the identification of several junctional molecules (Claudins and Catenins) that are negatively regulated by STAT3 at the time of implantation. Mouse uteirne epithelial cells were isolated from control and knockout mice on the morning of day 4 of pregnancy. (n=3 for each sample), pooled total RNA from these cells was then hybridized to high density affymetrix microarrays according to the Affymetrix protocol (Mouse Genome 430A 2.0 Array) .