Follistatin dysregulation impaired trophoblast biological functions by GDF11-Smad2/3 axis in preeclampsia placentas

Growth differentiation factor-11 upregulates matrix metalloproteinase 2 expression by inducing Snail in human extravillous trophoblast cells

The human extravillous trophoblast (EVT) cell invasion is an important process during placentation. Although the placenta is normal tissue, the EVT cells exhibit some features common to cancer cells, including high migratory and invasive properties. Snail and Slug are transcription factors that mediate the epithelial-mesenchymal transition (EMT), a crucial event for cancer cell migration and invasion. It has been shown that GDF-11-induced matrix metalloproteinase 2 (MMP2) expression is required for EVT cell invasion. Whether GDF-11 can regulate Snail and Slug expression in human EVT cells remains unknown. If it does, the involvement of Snail and Slug in GDF-11-induced MMP2 expression and EVT cell invasion must also be defined. In the present study, using the immortalized human EVT cell line, HTR-8/SVneo, and primary cultures of human EVT cells as experimental models, our results show that GDF-11 upregulates Snail and Slug expression. ALK4 and ALK5 mediate the stimulatory effects of GDF-11 on Snail and Slug expression. In addition, we demonstrate that SMAD2 and SMAD3 are required for the GDF-11-upregulated Snail expression, while only SMAD3 is involved in GDF-11-induced Slug expression. Moreover, our results reveal that Snail mediates GDF-11-induced MMP2 expression and cell invasion but not Slug. This study increases our understanding of the biological function of GDF-11 in human EVT cells and provides a novel mechanism for regulating MMP2 and EVT cell invasion.

Roles of bone morphogenetic proteins in endometrial remodeling during the human menstrual cycle and pregnancy

BACKGROUND

During the human menstrual cycle and pregnancy, the endometrium undergoes a series of dynamic remodeling processes to adapt to physiological changes. Insufficient endometrial remodeling, characterized by inadequate endometrial proliferation, decidualization and spiral artery remodeling, is associated with infertility, endometriosis, dysfunctional uterine bleeding, and pregnancy-related complications such as preeclampsia and miscarriage. Bone morphogenetic proteins (BMPs), a subset of the transforming growth factor-β (TGF-β) superfamily, are multifunctional cytokines that regulate diverse cellular activities, such as differentiation, proliferation, apoptosis, and extracellular matrix synthesis, are now understood as integral to multiple reproductive processes in women. Investigations using human biological samples have shown that BMPs are essential for regulating human endometrial remodeling processes, including endometrial proliferation and decidualization.

OBJECTIVE AND RATIONALE

This review summarizes our current knowledge on the known pathophysiological roles of BMPs and their underlying molecular mechanisms in regulating human endometrial proliferation and decidualization, with the goal of promoting the development of innovative strategies for diagnosing, treating and preventing infertility and adverse pregnancy complications associated with dysregulated human endometrial remodeling.

SEARCH METHODS

A literature search for original articles published up to June 2023 was conducted in the PubMed, MEDLINE, and Google Scholar databases, identifying studies on the roles of BMPs in endometrial remodeling during the human menstrual cycle and pregnancy. Articles identified were restricted to English language full-text papers.

OUTCOMES

BMP ligands and receptors and their transduction molecules are expressed in the endometrium and at the maternal-fetal interface. Along with emerging technologies such as tissue microarrays, 3D organoid cultures and advanced single-cell transcriptomics, and given the clinical availability of recombinant human proteins and ongoing pharmaceutical development, it is now clear that BMPs exert multiple roles in regulating human endometrial remodeling and that these biomolecules (and their receptors) can be targeted for diagnostic and therapeutic purposes. Moreover, dysregulation of these ligands, their receptors, or signaling determinants can impact endometrial remodeling, contributing to infertility or pregnancy-related complications (e.g. preeclampsia and miscarriage).

WIDER IMPLICATIONS

Although further clinical trials are needed, recent advancements in the development of recombinant BMP ligands, synthetic BMP inhibitors, receptor antagonists, BMP ligand sequestration tools, and gene therapies have underscored the BMPs as candidate diagnostic biomarkers and positioned the BMP signaling pathway as a promising therapeutic target for addressing infertility and pregnancy complications related to dysregulated human endometrial remodeling.

Upregulation of SEMP1 Contributes to Improving the Biological Functions of Trophoblast via the PI3K/AKT Pathway in Preeclampsia

Disturbance of extravillous trophoblast infiltration is associated with preeclampsia (PE), a severe condition of pregnancy characterized by hypertension and proteinuria. Senescence-associated epithelial membrane protein 1 (SEMP1), an integral membrane protein, is a vital component of tight junction strands in epithelial or endothelial cells, with no clear function reported in PE. Gene Expression Omnibus (GEO) datasets showed that SEMP1 expression was downregulated in the placental tissues of PE patients, which was confirmed by assessing SEMP1 levels in placental samples collected in our hospital. Furthermore, less SEMP1 was detected in cytokeratin 7 positive trophoblast cells in the spiral arteries of rat placentas post L-arginine methyl ester hydrochloride (L-NAME) treatment. Trophoblast cells acquired robust ability of proliferation, migration, and invasion when SEMP1 was overexpressed. Such capability was weakened in SEMP1-silenced cells. Trophoblast cells overexpressing SEMP1 secreted more vascular endothelial growth factor A (VEGFA), which facilitated the tube formation of human umbilical vein endothelial cells. Blockade of PI3K/AKT signaling transduction with LY294002 dampened the effects of SEMP1 on trophoblast cells. Collectively, we firstly indicated that SEMP1 inhibition is a potential driver for PE, which may be associated with the deactivation of the PI3K/AKT pathway.

Low follistatin level is a causal risk factor for spontaneous abortion: a two-sample mendelian randomization study

Background

Recurrent pregnancy loss is a distressing event during pregnancy, and understanding its causal factors is crucial. Follistatin, a glycoprotein involved in folliculogenesis and embryogenesis, has been implicated as a potential contributor to the risk of spontaneous abortion. However, establishing a causal relationship requires rigorous investigation using robust methods.

Methods

In this study, we utilized mendelian randomization (MR), a powerful genetic epidemiological approach, to examine the causal relationship between follistatin levels and spontaneous abortion. We obtained instrumental variables strongly associated with follistatin levels from large-scale genome-wide association from the IEU database. The inverse variance weighting (IVW) method was taken as gold standard. We also performed sensitivity test to evaluate the robustness of our result.

Results

MR analysis revealed a significant causal relationship between low follistatin levels and spontaneous abortion (p = 0.03). Sensitivity analyses, including pleiotropy test, heterogeneity test, and leave-one-out analysis, all supported the robustness of our findings.

Conclusion

Our study provides compelling evidence supporting the causal relationship between low follistatin levels and increased risk of spontaneous abortion. These findings underscore the importance of follistatin in the etiology of spontaneous abortion and suggest potential preventive interventions. Modulating follistatin levels or relevant pathways could hold promise for reducing the incidence of spontaneous abortion and improving reproductive outcomes. The utilization of MRs strengthens the validity of our results by mitigating confounding and reverse causality biases. Further research is needed to elucidate the underlying molecular mechanisms and explore therapeutic strategies targeting follistatin levels.

Growth differentiation factor 11: A new hope for the treatment of cardiovascular diseases

Growth differentiation factor 11 (GDF11) is a member of the transforming growth factor-β superfamily that has garnered significant attention due to its anti-cardiac aging properties. Many studies have revealed that GDF11 plays an indispensable role in the onset of cardiovascular diseases (CVDs). Consequently, it has emerged as a potential target and novel therapeutic agent for CVD treatment. However, currently, no literature reviews comprehensively summarize the research on GDF11 in the context of CVDs. Therefore, herein, we comprehensively described GDF11's structure, function, and signaling in various tissues. Furthermore, we focused on the latest findings concerning its involvement in CVD development and its potential for clinical translation as a CVD treatment. We aim to provide a theoretical basis for the prospects and future research directions of the GDF11 application regarding CVDs.

Extracellular vesicles secreted by adenomyosis endometrial organoids contain miRNAs involved in embryo implantation and pregnancy

RESEARCH QUESTION

Do extracellular vesicles secreted by the endometrium of women with adenomyosis contain miRNAs involved in adenomyosis-related infertility?

DESIGN

A descriptive study using organoids from eutopic endometrium of women with adenomyosis (n = 4) generated and differentiated to secretory and gestational phases, in which miRNA cargo from extracellular vesicles secreted by these differentiated organoids in each phase was analysed by next-generation sequencing. miRNAs in secretory-extracellular vesicles and gestational-extracellular vesicles were selected based on the counts per million. miRNAs target genes in each phase were obtained from miRNet and gene ontology was used for enrichment analysis.

RESULTS

miRNA sequencing identified 80 miRNAs in secretory-phase extracellular vesicles, including hsa-miR-21-5p, hsa-miR-24-3p, hsa-miR-26a-5p, hsa-miR-92a-3p, hsa-miR-92b-3p, hsa-miR-200c-3p and hsa-miR-423a-5p, related to adenomyosis pathogenesis and implantation failure. Further, 60 miRNAs were identified in gestational-phase extracellular vesicles, including hsa-miR-21-5p, hsa-miR-26a-5p, hsa-miR-30a-5p, hsa-miR-30c-5p, hsa-miR-222-3p and hsa-miR-423a-5p were associated with preeclampsia and miscarriage. Among the target genes of these miRNAs, PTEN, MDM4, PLAGL2 and CELF1, whose downregulation (P = 0.0003, P < 0.0001, P = 0.0002 and P = 0.0003, respectively) contributes to adenomyosis pathogenesis, and impaired early embryo development, leading to implantation failure and miscarriage, are highlihghted. Further, functional enrichment analyses of the target genes revealed their involvement in cell differentiation, proliferation, apoptosis, cell cycle regulation and response to extracellular stimuli.

CONCLUSIONS

Eutopic endometrium in secretory and gestational phase from women with adenomyosis releases extracellular vesicles containing miRNAs involved in adenomyosis progression, impaired embryo implantation and pregnancy complications.

Role of microRNAs in trophoblast invasion and spiral artery remodeling: Implications for preeclampsia

It is now well-established that microRNAs (miRNAs) are important regulators of gene expression. The role of miRNAs in placental development and trophoblast function is constantly expanding. Trophoblast invasion and their ability to remodel uterine spiral arteries are essential for proper placental development and successful pregnancy outcome. Many miRNAs are reported to be dysregulated in pregnancy complications, especially preeclampsia and they exert various regulatory effects on trophoblasts. In this review, we provide a brief overview of miRNA biogenesis and their mechanism of action, as well as of trophoblasts differentiation, invasion and spiral artery remodeling. We then discuss the role of miRNAs in trophoblasts invasion and spiral artery remodeling, focusing on miRNAs that have been thoroughly investigated, especially using multiple model systems. We also discuss the potential role of miRNAs in the pathogenesis of preeclampsia.