Expression of nidogens in rat uterus and embryo during decidualization and implantation

Progesterone-stimulated endometrial cell conditioned media increases in vitro produced bovine embryo blastocyst formation

The early bovine embryo is supported by histotroph molecules secreted by endometrial epithelial (EPI) and stroma fibroblast (SF) cells in response to luteal progesterone (P4). We hypothesized that specific histotroph molecule transcript abundance depends on cell type and P4 concentration and that endometrial cell conditioned media (CM) could improve in vitro produced (IVP) embryo development in culture. Primary bovine EPI and SF cells from seven uteri were incubated for 12 h with RPMI medium containing 0 (Control), 1, 15, or 50 ng of P4. RPMI was also incubated without cells (N-CM) and CM from EPI or SF cultures (EPI- or SF-CM) or a combination of the two (1:1; EPI/SF-CM) was used to culture IVP embryos from days 4-8 of development (n = 117). There was an effect of cell type (SLC1A1, SLC5A6, SLC7A1, FGF-2, FGF-7, CTGF, PRSS23 and NID2) and/or P4 concentration (FGF-7 and NID2) on endometrial cell histotroph molecule mRNA (P < 0.05). Compared to N-CM, blastocyst development on day 7 was greater in the EPI or SF-CM (P ≤ 0.05) and tended to be greater in the EPI/SF-CM (P = 0.07). On day 8, blastocyst development was greater only in the EPI-CM (P < 0.05). Further, culturing embryos with endometrial cell CM reduced day 8 blastocyst transcript abundance of cell adhesion molecule LGALS1 (P < 0.01). In conclusion, endometrial cell CM or histotroph molecules may be used to improve IVP embryo development in cattle.

Intercellular communication involving macrophages at the maternal-fetal interface may be a pivotal mechanism of URSA: a novel discovery from transcriptomic data

Unexplained recurrent spontaneous abortion (URSA) is a severe challenge to reproductive females worldwide, and its etiology and pathogenesis have not yet been fully clarified. Abnormal intercellular communication between macrophages (Mφ) and decidual stromal cells (DSCs) or trophoblasts has been supposed to be the key to URSA. However, the exact molecular mechanisms in the crosstalk are not yet well understood. This study aimed to explore the potential molecule mechanism that may be involved in the communication between Mφ and DSC or trophoblast cells and determine their diagnostic characteristics by using the integrated research strategy of bioinformatics analysis, machine learning and experiments. First, microarrays of decidual tissue (GSE26787, GSE165004) and placenta tissue (GSE22490) in patients with URSA, as well as microarrays involving induced decidualization (GSE94644) and macrophage polarization in vitro (GSE30595) were derived from the gene expression omnibus (GEO) database. And 721 decidua-differentially expressed genes (DEGs), 613 placenta-DEGs, 510 Mφ polarization DEGs were obtained in URSA by differential expression analysis. Then, the protein-protein interaction (PPI) network was constructed, and the hub genes were identified by CytoHubba in Cytoscape software and validated by real-time PCR assay. Subsequently, immune enrichment analysis on decidua-DEGs and placenta-DEGs by ClueGO verified their regulation effects on Mφ. Besides, functional enrichment analysis was performed on Mφ polarization DEGs and the essential module genes derived from the weighted gene co-expression network analysis (WGCNA) to uncover the biological function that were related to abnormal polarization of Mφ. Furthermore, we screened out 29, 43 and 22 secreted protein-encoding genes from DSC-DEGs, placenta-DEGs and Mφ polarization DEGs, respectively. Besides, the hub secreted-protein-encoding genes were screened by CytoHubba. Moreover, we conducted functional enrichment analysis on these genes. And spearman correlation analysis between hub secreted-protein-encoding genes from donor cells and hub genes in recipient cells was performed to further understand the molecular mechanism of intercellular communication further. Moreover, signature genes with diagnostic value were screened from secreted protein-encoding genes by machine learning and validated by immunofluorescence co-localization analysis with clinical samples. Finally, three biomarkers of DSCs (FGF9, IL1R2, NID2) and three biomarkers of Mφ (CFB, NID2, CXCL11) were obtained. In conclusion, this project provides new ideas for understanding the mechanism regulatory network of intercellular communication involving macrophages at the maternal-fetal interface of URSA. Also, it provides innovative insights for the diagnosis and treatment of URSA.

Expression of extracellular matrix proteins nidogen-1 and legumain in endometrial carcinomas

PURPOSE

Our purpose was to comparatively investigate the expressions of nidogen-1 (NID1) and legumain (LGMN) in patients with endometrial cancer, endometrial intraepithelial neoplasia, and proliferative endometrium.

METHODS

A cross-sectional, single-center study was performed by the obstetrics and gynecology and pathology departments of our institution. The relationships between descriptive data, clinicopathologic information, and immunohistochemical expressions of NID1 and LGMN were investigated.

RESULTS

The histological grades of endometrial cancers (n = 124) as classified by FIGO included 1 (41, 21.1%), 2 (48, 24.7%), and 3 (35, 18.0%). The medians and ranges of deep and superficial NID1 expressions were 50.00 (0-285) and 5.00 (0-100), respectively. The intensity of legumain expression was noted as negative (30, 24.2%), mild (16, 12.9%), moderate (27, 21.8%), or strong (51, 41.1%). Median disease-free survival and overall survival were 75.00 (range: 1 to 170) months and 77.00 (range: 1 to 170) months, respectively. Patients with more intense expression of NID1 and LGMN displayed a higher histological grade. These patients were more likely to have a positive peritoneal cytology, larger tumor size, higher tendency for myometrial or lymphovascular invasion, involvement of ovaries, cervix, omentum, as well as lymph node metastasis, and recurrence.

CONCLUSION

Our data indicated that the expressions of NID1 and LGMN may have important diagnostic implications in endometrial pathologies. Further studies should be performed to understand the significance of NID1 and LGMN in the pathogenesis of endometrial tumors.

In-vitro construction of endometrial-like epithelium using CD146+ mesenchymal cells derived from human endometrium

Endometrial CD146⁺ cells were purified, using magnetic activated cell sorting, and then embedded and cultured in a collagen-matrigel scaffold on top of myometrial smooth muscle cells for 10 days. At the end of culture period, the differentiation and formation of the epithelial-like cells were confirmed by morphological and ultrastructural evaluations, and analysis by reverse transcription polymerase chain reaction of the specific expression of genes: osteopontin (SPP1), matrix metalloproteinase 2, zonula occludens 1, laminin alpha 2 and collagen type IV; and by western blotting of CD9 protein. The results showed that the human endometrial mesenchymal CD146⁺ cells were able to produce endometrial glandular tube-like structures in vitro. Ultrastructural observation revealed some projections on the apical surfaces, appearance of basal lamina-like structures on the basal surface, and tight junctions and desmosomes on the lateral surfaces of the epithelial-like cells. The expression of studied genes at RNA level and CD9 at protein level confirmed the formation of endometrial epithelial-like cells. This culture system may have potential applications in cell therapy and in studies on human embryo implantation.

BMP4 signaling directs primitive endoderm-derived XEN cells to an extraembryonic visceral endoderm identity

The visceral endoderm (VE) is an epithelial tissue in the early postimplantation mouse embryo that encapsulates the pluripotent epiblast distally and the extraembryonic ectoderm proximally. In addition to facilitating nutrient exchange before the establishment of a circulation, the VE is critical for patterning the epiblast. Since VE is derived from the primitive endoderm (PrE) of the blastocyst, and PrE-derived eXtraembryonic ENdoderm (XEN) cells can be propagated in vitro, XEN cells should provide an important tool for identifying factors that direct VE differentiation. In this study, we demonstrated that BMP4 signaling induces the formation of a polarized epithelium in XEN cells. This morphological transition was reversible, and was associated with the acquisition of a molecular signature comparable to extraembryonic (ex) VE. Resembling exVE which will form the endoderm of the visceral yolk sac, BMP4-treated XEN cells regulated hematopoiesis by stimulating the expansion of primitive erythroid progenitors. We also observed that LIF exerted an antagonistic effect on BMP4-induced XEN cell differentiation, thereby impacting the extrinsic conditions used for the isolation and maintenance of XEN cells in an undifferentiated state. Taken together, our data suggest that XEN cells can be differentiated towards an exVE identity upon BMP4 stimulation and therefore represent a valuable tool for investigating PrE lineage differentiation.

Spatiotemporal coupling of focal extracellular matrix degradation and reconstruction in the menstrual human endometrium

Coupling of focal degradation and renewal of the functional layer of menstrual endometrium is a key event of the female reproductive biology. The precise mechanisms by which the various endometrial cell populations control extracellular matrix (ECM) degradation in the functionalis while preserving the basalis and the respective contribution of basalis and functionalis in endometrium regeneration are still unclear. We therefore compared the transcriptome of stromal and glandular cells isolated by laser capture microdissection from the basalis as well as degraded and preserved areas of the functionalis in menstrual endometria. Data were validated by in situ hybridization. Expression profile of selected genes was further analyzed throughout the menstrual cycle, and their response to ovarian steroids withdrawal was studied in a mouse xenograft model. Immunohistochemistry confirmed the results at the protein level. Algorithms for sample clustering segregated biological samples according to cell type and tissue depth, indicating distinct gene expression profiles. Pairwise comparisons identified the greatest numbers of differentially expressed genes in the lysed functionalis when compared with the basalis. Strikingly, in addition to genes products associated with tissue degradation (matrix metalloproteinase and plasmin systems) and apoptosis, superficial lysed stroma was enriched in gene products associated with ECM biosynthesis (collagens and their processing enzymes). These results support the hypothesis that fragments of the functionalis participate in endometrial regeneration during late menstruation. Moreover, menstrual reflux of lysed fragments overexpressing ECM components and adhesion molecules could easily facilitate implantation of endometriotic lesions.

Expression of alphaVbeta3 integrin in rat endometrial epithelial cells and its functional role during implantation

The alpha(V)beta(3) integrin as a marker of endometrial receptivity has been well established in human and other mammalian species; however, its expression is still not known in rats. Our objective was to establish the expression of alpha(V)beta(3) integrin as a marker of endometrial receptivity in rat and to further prove its role in implantation by function-blocking studies in this species. Immunocytochemical, immunohistochemical and flow-cytometric studies were performed in rat endometrial epithelial cells (EEC) to demonstrate the expression of alpha(V)beta(3) integrin during non-receptive, pre-receptive and receptive phases of the uterus. Results revealed positive immunocytochemical staining for alpha(v) and beta(3) subunits on the surface of EEC of days 4 and 5p.c. (post-coitum), but the intensity was higher in cells of day 5p.c. Flow-cytometric study revealed higher level of alpha(V)beta(3) on day 5p.c. as compared to day 4p.c. and non-pregnant animals. Immunohistochemical analysis of uterine tissue also revealed that the alpha(V)beta(3) expression in LE was higher on day 5p.c. morning as compared to that observed on day 4p.c. In addition, the expression of beta(3) subunit was not evident in rats receiving ormeloxifene, an agent known to inhibit the uterine receptivity. Immunoblotting experiments also revealed higher expression of uterine beta(3) on day 5p.c. On day 6, expression of beta(3) was high in implantation sites than on inter-implantation sites. In immature ovariectomized rats, alpha(V)beta(3) was up-regulated by progesterone and by a combination of estrogen and progesterone. The expression of alpha(V)beta(3) was also up-regulated in EEC co-cultured with blastocysts. All the agents used for function-blocking studies showed significant reduction in the number of implantation sites in treated horn as compared to sham control horn. The present study has successfully demonstrated the expression of alpha(V)beta(3) in rat EEC as a marker of endometrial receptivity and showed that this molecule is indispensable for the process of implantation in this species.