Ephrin and Eph receptor signaling in female reproductive physiology and pathology†

Identification of potent pan-ephrin receptor kinase inhibitors using DNA-encoded chemistry technology

EPH receptors (EPHs), the largest family of tyrosine kinases, phosphorylate downstream substrates upon binding of ephrin cell surface-associated ligands. In a large cohort of endometriotic lesions from individuals with endometriosis, we found that EPHA2 and EPHA4 expressions are increased in endometriotic lesions relative to normal eutopic endometrium. Because signaling through EPHs is associated with increased cell migration and invasion, we hypothesized that chemical inhibition of EPHA2/4 could have therapeutic value. We screened DNA-encoded chemical libraries (DECL) to rapidly identify EPHA2/4 kinase inhibitors. Hit compound, CDD-2693, exhibited picomolar/nanomolar kinase activity against EPHA2 (Ki: 4.0 nM) and EPHA4 (Ki: 0.81 nM). Kinome profiling revealed that CDD-2693 bound to most EPH family and SRC family kinases. Using NanoBRET target engagement assays, CDD-2693 had nanomolar activity versus EPHA2 (IC50: 461 nM) and EPHA4 (IC50: 40 nM) but was a micromolar inhibitor of SRC, YES, and FGR. Chemical optimization produced CDD-3167, having picomolar biochemical activity toward EPHA2 (Ki: 0.13 nM) and EPHA4 (Ki: 0.38 nM) with excellent cell-based potency EPHA2 (IC50: 8.0 nM) and EPHA4 (IC50: 2.3 nM). Moreover, CDD-3167 maintained superior off-target cellular selectivity. In 12Z endometriotic epithelial cells, CDD-2693 and CDD-3167 significantly decreased EFNA5 (ligand) induced phosphorylation of EPHA2/4, decreased 12Z cell viability, and decreased IL-1β-mediated expression of prostaglandin synthase 2 (PTGS2). CDD-2693 and CDD-3167 decreased expansion of primary endometrial epithelial organoids from patients with endometriosis and decreased Ewing's sarcoma viability. Thus, using DECL, we identified potent pan-EPH inhibitors that show specificity and activity in cellular models of endometriosis and cancer.

Long non-coding RNAs: a summary of their roles in placenta development and pathology†

Long non-coding RNAs are cellular transcripts that have ˃200 nucleotides in length and do not code for proteins. Due to their low expression levels, long non-coding RNAs were previously considered as mere transcriptional noise. However, current evidence indicates that they regulate a myriad of biological processes such as cell proliferation, invasion, and apoptosis. Hence, their expression patterns are crucial indicators of the physiological or pathological states of cells, tissues, and organs. The utilization of long non-coding RNAs as biomarkers and therapeutic targets for the clinical management of several diseases have been suggested. Gradually, long non-coding RNAs are gaining a substantial attention in the field of feto-maternal medicine. After embryo implantation, the interactions between the trophoblast cells from the embryo and the uterus of the mother facilitate placenta development and pregnancy progression. These processes are tightly regulated, and their impairments result in pregnancy pathologies such as miscarriage and preeclampsia. Accumulating evidence implicates long non-coding RNAs in these processes. Herein, we have summarized the roles of several long non-coding RNAs in human placenta development, have proposed some mechanisms by which they participate in physiological and pathological placentation, have revealed some knowledge deficits, and have recommended ideal experimental approaches that will facilitate the clarification of the mechanistic actions of each long non-coding RNA at the feto-maternal interface during healthy and pathological pregnancies.

Exploring the potential of EphA2 receptor signaling pathway: a comprehensive review in cancer treatment

The protein encoded by the ephrin type-A receptor 2 (EphA2) gene is a member of the ephrin receptor subfamily of the receptor tyrosine kinase family (RTKs). Eph receptors play a significant role in various biological processes, particularly cancer progression, development, and pathogenesis. They have been observed to regulate cancer cell growth, migration, invasion, tumor development, invasiveness, angiogenesis, and metastasis. To target EphA2 activity, various molecular, genetic, biochemical, and pharmacological strategies have been extensively tested in laboratory cultures and animal models. Notably, drugs, such as dasatinib, initially designed to target the kinase family, have demonstrated an additional capability to target EphA2 activity. Additionally, a novel monoclonal antibody named EA5 has emerged as a promising option to counteract the effects of EphA2 overexpression and restore tamoxifen sensitivity in EphA2-transfected MCF-7 cells during in vitro experiments. This antibody mimicked the binding of Ephrin A to EphA2. These methods offer potential avenues for inhibiting EphA2 activity, which could significantly decelerate breast cancer progression and restore sensitivity to certain drugs. This review article comprehensively covers EphA2's involvement in multiple malignancies, including ovarian, colorectal, breast, lung, glioma, and melanoma. Furthermore, we discuss the structure of EphA2, the Eph-Ephrin signaling pathway, various EphA2 inhibitors, and the mechanisms of EphA2 degradation. This article provides an extensive overview of EphA2's vital role in different types of cancers and outlines potential therapeutic approaches to target EphA2, shedding light on the underlying molecular mechanisms that make it an attractive target for cancer treatment.

Mechanistic actions of long non-coding RNA MALAT1 within the ovary and at the feto-maternal interface

Long non-coding RNAs (LncRNAs) are being unveiled as crucial regulators of several biological processes and pathways. Among the lncRNAs is metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), which is also known as nuclear enriched abundant transcript 2 (NEAT2). MALAT1 is highly conserved in mammals, and controls cellular processes such as proliferation, migration, invasion, angiogenesis, and apoptosis in both physiological and pathological conditions. Roles of MALAT1 in the female reproductive system are gradually getting explored. Within the ovarian micro-environment, the physiological expression of MALAT1 potentially modulates folliculogenesis while its upregulation promotes the metastasis of epithelial ovarian cancers. Interestingly, women with polycystic ovary syndrome have been shown to exhibit aberrant ovarian expression of MALAT1 and this is believed to contribute to the development of the disease. At the feto-maternal interface, MALAT1 potentially promotes trophoblast development. While its placental downregulation is linked to the pathogenesis of preeclampsia, its placental upregulation is associated with placenta increta and placenta percreta. Hence, abnormal expression of MALAT1 is a candidate molecular biomarker and therapeutic target for the treatment of these obstetric and gynecologic anomalies. To enhance a quick uncovering and detailed characterization of the mechanistic actions of MALAT1 in the female reproductive system, we have highlighted some knowledge deficits and have recommended ideal experimental models to be employed in prospective investigations.

Transcriptome profiling reveals transcriptional regulation of Protegrin-1 on immune defense and development in porcine granulosa cells

Protegrin-1 (PG1) is an antimicrobial peptide (AMP) that has garnered increasing attention due to its potent immune defense activity. Our previous studies demonstrated the ability of PG1 to enhance proliferation and inhibit apoptosis of porcine granulosa cells (GCs) under oxidative stress. GCs play a crucial role in ovary follicular development. However, the specific function and underlying mechanisms of AMP in follicular development still need further elucidation. The present study aimed to comprehensively explore the biological effects of PG1 on porcine GCs using transcriptome profiling by RNA sequencing technology. Isolated GCs were incubated with or without PG1 for 24 h and transcriptome-wide analysis was exerted to identify differentially expressed genes (DEGs). The results of expression analysis revealed 1,235 DEGs, including 242 up-regulated genes and 993 down-regulated genes (|log2 (FoldChange)| > 1; adjusted P-value < 0.05). The expression levels of 7 selected DEGs were validated by quantitative reverse transcription-polymerase chain reaction (RT-qPCR) analysis, which was consistent with the RNA-sequencing data. Among the significant DEGs, several genes associated with GC function and ovarian follicle development were identified, such as estrogen receptor 2 (ESR2), growth and differentiation factor 6 (GDF6), cell division cycle 20 homolog (CDC20), Notch3, ephrin and Eph receptor system, Egl nine homolog 3 (EGLN3), and BCL2 like 14 (BCL2L14). Gene Ontology (GO) analysis revealed that the top three significant GO terms were inflammatory response, defense response, and granulocyte migration. Additionally, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis presented that DEGs were mainly enriched in the immune system, infectious disease, signaling molecules and interaction, and immune disease. Furthermore, Ingenuity Pathway Analysis (IPA) predicted that the top activated pathway was Liver X Receptor (LXR)/ Retinoid X Receptor (RXR) Activation which is known to be associated with female reproduction. Predicted protein-protein interactions (PPIs) analysis identified complement C3 (C3) as the top node with the highest degree of network connection and revealed that DEGs in the sub-networks were involved in cytokine-cytokine receptor interaction, neuroactive ligand-receptor interaction, chemokine signaling pathway, and metabolic process. In conclusion, this study expanded the understanding of the effects of PG1 on porcine GCs at the transcriptomic level and provided a theoretical basis for further investigation into the role of PG1 in immune defense and mammalian ovarian follicular development.

Long noncoding RNA H19 in ovarian biology and placenta development

As the first long noncoding RNA to be discovered, H19 has gained substantial attention as a key regulator of several biological processes and its roles in female reproductive biology are gradually getting revealed. Herein, we have summarized the current evidence regarding H19 expression pattern and involvement in the developmental and pathological processes associated with the ovary and the placenta. The findings indicate that within the ovaries, H19 is expressed in the antral and cystic atretic follicles as well as in the corpora lutea but absent in the primordial, primary, and secondary follicles. Its normal expression promotes the maturation of antral follicles and prevents their premature selection for the ovulatory journey while its aberrant induction promotes polycystic ovary syndrome development and ovarian cancer metastasis. In the placenta, H19 is highly expressed in the cytotrophoblasts and extravillous trophoblasts but weakly expressed in the syncytiotrophoblast layer and potentially controls trophoblast cell fate decisions during placenta development. Abnormal expression of H19 is observed in the placental villi of pregnancies affected by pre-eclampsia and fetal growth restriction. Therefore, dysregulated H19 is a candidate biomarker and therapeutic target for the mitigation of ovarian and placenta-associated diseases.

Small RNA sequencing of exosomal microRNAs reveals differential expression of microRNAs in preeclampsia

Preeclampsia (PE) is one of the most common hypertensive disorders of pregnancy. It is a dangerous condition with a high mortality rate in mothers and fetuses and is associated with a lack of early diagnosis and effective treatment. While the etiology of the disease is complex and obscure, it is now clear that the placenta is central to disease progression. Exosomal microRNAs (miRNAs) are possible mediators that regulate placenta-related physiological and pathological processes. Placental mesenchymal stem cells have considerable potential to help us understand the pathogenesis and treatment of pregnancy-related diseases. Here, we investigate the exosomal miRNA profiles of human placenta-derived mesenchymal stem cells between healthy pregnant women and those with PE. We performed small RNA sequencing to obtain miRNA profiles, and conducted enrichment analysis of the miRNA target genes to identify differentially expressed miRNAs associated with PE. Overall, we detected 1795 miRNAs; among them, 206 were differentially expressed in women with PE, including 35 upregulated and 171 downregulated miRNAs, when compared with healthy pregnant women. Moreover, we identified possible functions and pathways associated with PE, including angiogenesis, cell proliferation, migration and invasion, and the coagulation-fibrinolysis balance. Eventually, we proposed hsa-miR-675-5p, hsa-miR-3614-5p, and hsa-miR-615-5p as potential regulators of the pathogenesis of PE, and constructed a miRNA-target gene network. Our study identifies possible candidate biomarkers for the diagnosis of PE, and introduces a new direction for further understanding the pathogenesis of PE.

Characterization of the lncRNA-mediated ceRNA regulatory networks in preeclampsia by integrated bioinformatics

Preeclampsia (PE) is a significant threat to all pregnancies that is highly associated with maternal mortality and developmental disorders in infants. However, the etiopathogenesis of this condition remains unclear. This study aims to explore the regulatory roles of long noncoding RNAs (lncRNAs) and the mediated competing endogenous RNAs (ceRNA) in the etiopathogenesis of PE through analysis of lncRNA expression patterns in PE and healthy pregnant women (HPW), as well as the construction of lncRNA-mediated ceRNA regulatory networks using bioinformatics. A total of 896 significant differentially expressed lncRNAs, including 586 upregulated lncRNAs and 310 downregulated lncRNAs, were identified in comparison between PE and HPW. Analysis of these differential expressed lncRNAs revealed their predominant enrichment in molecular functions such as sphingosine-1-phosphate phosphatase activity, lipid phosphatase activity, phosphatidate phosphatase activity, thymidylate kinase activity, and UMP kinase activity. Moreover, these differential expressed lncRNAs were predominantly enriched in KEGG analyses such as fat digestion and absorption, lysine degradation, ether lipid metabolism, glycerolipid metabolism, and sphingolipid metabolism. Two ceRNA regulatory networks were constructed based on ceRNA score, including one that had 31 upregulated lncRNAs, 11 downregulated miRNAs, and 34 upregulated mRNAs, while the other contained 128 downregulated lncRNAs, 40 upregulated miRNAs, and 113 downregulated mRNAs. These results may provide a clue to explore the roles of lncRNAs in the etiopathogenesis of PE.

Iodothyronine deiodinase 2 (DiO2) regulates trophoblast cell line cycle, invasion and apoptosis; and its downregulation is associated with early recurrent miscarriage

INTRODUCTION

Trophoblast development is a crucial event in placentation and pregnancy complications but its underlying mechanisms remain unclear. Thus, we aimed at investigating the role of DiO2 in trophoblast cell line decisions and assessing its placental villous expression in early recurrent miscarriage (ERM) patients.

METHODS

The placental villous expression of DiO2 was determined with immunofluorescence. Cell proliferation was measured with the CCK8 kit while cell-cycle and apoptosis were studied with flow-cytometry. Cell migration and invasion were measured with wound-healing and transwell assays, respectively. Gene expression was then assessed with RT-qPCR and western blotting.

RESULTS

DiO2 is expressed in the CTB, PCT, DCT and STB of the placenta. Its overexpression arrested trophoblast cell line proliferation at the G1 phase of the cell-cycle by downregulating cyclin-D1 and PCNA, while promoting apoptosis via increased caspase-3 activity and inhibition of the AKT and ERK1/2 signaling pathways. Also, it augmented trophoblast cell line migration and invasion via the upregulation of N-cadherin, vimentin, fascin-1, twist-1 and other epithelial-mesenchymal transition genes. DiO2 knockdown elicited the opposite effects. Surprisingly, each of these effects of DiO2 manipulation was not mediated by thyroid hormone metabolism. Assessment of the ERM placental villi revealed a downregulation of DiO2, N-cadherin, vimentin, fascin-1 and twist-1. The expression of E-cadherin remained unchanged in these placentae.

DISCUSSION

During placentation, DiO2 may inhibit trophoblast proliferation while facilitating their differentiation into an invasive phenotype; and that its downregulation may contribute to the shallow trophoblast invasion that precedes ERM. Hence, DiO2 is a potential therapeutic target against ERM.

Expression and localisation of ephrin-B1 and EphB4 in steroidogenic cells in the naturally cycling mouse ovary

Ephrin receptors and ligands are membrane-bound molecules that modulate diverse cellular functions such as cell adhesion, epithelial-mesenchymal transition, motility, differentiation and proliferation. We recently reported the co-expression of ephrin-B1 and EphB4 in adult and foetal Leydig cells of the mouse testis, and thus speculated that their co-expression is a common property in gonadal steroidogenic cells. Therefore, in this study we examined the expression and localisation of ephrin-B1 and EphB4 in the naturally cycling mouse ovary, as their expression patterns in the ovary are virtually unknown. We found that ephrin-B1 and EphB4 were co-expressed in steroidogenic cells of all kinds, i.e. granulosa cells and CYP17A1-positive steroidogenic theca cells as well as in 3β-HSD-positive luteal cells and the interstitial glands; their co-expression potentially serves as a good marker to identify sex steroid-producing cells even in extra-gonadal organs/tissues. We also found that ephrin-B1 and EphB4 expression in granulosa cells was faint and strong, respectively; ephrin-B1 expression in luteal cells was weak in developing and temporally mature corpora lutea (those of the current cycle) and likely strong in regressing corpora lutea (those of the previous cycle) and EphB4 expression in luteal cells was weak in corpora lutea of the current cycle and likely faint/negative in the corpora lutea of the previous cycle. These findings suggest that a luteinising hormone surge triggers the upregulation of ephrin-B1 and downregulation of EphB4, as this expression fluctuation occurs after the surge. Overall, ephrin-B1 and EphB4 expression patterns may represent benchmarks for steroidogenic cells in the ovary.

The Involvement of Cell Adhesion Molecules, Tight Junctions, and Gap Junctions in Human Placentation

Placentation is a major determinant of the success of pregnancy. It is regulated by several factors such as cell adhesion molecules, tight junctions, and gap junctions. The cell adhesion molecules are integrins, cadherins, immunoglobulins, nectins, and selectins. The tight junctions are composed of claudins, occludin, and junction adhesion molecule proteins while the gap junctions are composed of connexins of varying molecular weights. During placentation, some of these molecules regulate trophoblast proliferation, trophoblast fusion, trophoblast migration, trophoblast invasion, trophoblast-endothelium adhesion, glandular remodeling, and spiral artery remodeling. There is a dysregulated placental expression of some of these molecules during obstetric complications. We have, hereby, indicated the expression patterns of the subunits of each of these molecules in the various trophoblast subtypes and in the decidua, and have highlighted their involvement in physiological and pathological placentation. The available evidence points to the relevance of these molecules as distinguishing markers of the various trophoblast lineages and as potential therapeutic targets in the management of malplacentation-mediated diseases.