Exosomal MicroRNA-325 Enhances Trophoblast Migration and Invasion Through Downregulation of Lethal-7b and Upregulation of Forkhead Box Protein O1 Expression in Preeclampsia

We aimed to explore the mechanism by how microRNA (miRNA)-325 derived from marrow mesenchymal stem cell exosomes (MSC-exos) affects the trophoblast progression in preeclampsia (PE). RT-qPCR detected the level of miRNA let-7b and FOXO1 in the placenta tissue of PE patients. Functional experiment was performed to analyze the effect of FOXO1 inhibitor and let-7b mimics on cell migration, invasion and apoptosis through Transwell assay and TUNEL staining. The trophoblast cell was co-cultured with overexpressed-miR-325 MSC-exos to measure gene expression and cell progression. let-7b was highly and FOXO1 was lowly expressed in PE placenta tissue. let-7b directly targeted and inhibited FOXO1 expression. Importantly, as miR-325 was internalized by trophoblast cells through MSC-exos, MSC-exos overexpressing miR-325 inhibited let-7b expression in trophoblasts, up-regulated FOXO1 and activated AKT signaling pathway. Further, MSC-exos treatment promoted invasion and migration of trophoblast cell and inhibited apoptosis. In conclusion, miR-325 derived from MSC-exos promotes the invasion and migration of trophoblast cells in PE through inhibition of let7b and upregulation of FOXO1.

ZBED1 Regulates Genes Important for Multiple Biological Processes of the Placenta

The transcription factor ZBED1 is highly expressed in trophoblast cells, but its functions in the processes of trophoblast and placental biology remain elusive. Here, we characterized the role of ZBED1 in trophoblast cell differentiation using an in vitro BeWo cell model. We demonstrate that ZBED1 is enhanced in its expression early after forskolin-induced differentiation of BeWo cells and regulates many of the genes that are differentially expressed as an effect of forskolin treatment. Specifically, genes encoding markers for the differentiation of cytotrophoblast into syncytiotrophoblast and factors essential for trophoblast cell fusion and invasion were negatively regulated by ZBED1, indicating that ZBED1 might be important for maintaining a steady pool of cytotrophoblast cells. In addition, ZBED1 affected genes involved in the regulation of trophoblast cell survival and apoptosis, in agreement with the observed increase in apoptosis upon knockdown of ZBED1 in forskolin-treated BeWo cells. In addition, genes implicated in the differentiation, recruitment, and function of innate immune cells by the placenta were affected by ZBED1, further suggesting a role for this protein in the regulation of maternal immune tolerance. In conclusion, our study implicates ZBED1 in major biological processes of placental biology.

Myostatin increases human trophoblast cell invasion by upregulating N-cadherin via SMAD2/3-SMAD4 Signaling

Placental insufficiency disorders are major obstetric complications that share a common phenomenon of poor placental trophoblast cell invasion and remodeling of uterine tissues. Myostatin is a transforming growth factor (TGF)-β superfamily member well-known for its important role in muscle growth control. Myostatin is also produced in the placenta and has been shown to regulate some trophoblast functions. However, its roles in placental development are still poorly understood. In this study, we tested the hypothesis that myostatin increases trophoblast cell invasion by upregulating N-cadherin via SMAD2/3-SMAD4 signaling. Primary and immortalized (HTR8/SVneo) trophoblast cells were used as study models. Matrigel-coated transwell invasion assays were used to study the effects of recombinant human myostatin on trophoblast cell invasion. RT-qPCR and Western blot were used to measure myostatin effects on N-cadherin mRNA and protein levels, respectively. Small inhibitor molecules as well as siRNA-mediated knockdown were used to block myostatin receptor and downstream signaling, respectively. Data were analyzed either by unpaired Student T test or one-way ANOVA followed by Newman Keuls test for multiple group comparisons. Myostatin significantly increased primary and HTR8/SVneo trophoblast cell invasion. Moreover, myostatin upregulated N-cadherin mRNA and protein levels in a time dependent manner in both study models. These effects were blocked by inhibition of TGF-β type I receptors as well as siRNA-mediated knockdown of SMAD2/3 combined or common SMAD4. Importantly, myostatin-induced trophoblast cell invasion was abolished by knockdown of N-cadherin, SMAD2/3 or SMAD4. Myostatin may increase human trophoblast cell invasion by upregulating N-cadherin via SMAD2/3-SMAD4 signaling.

PM10 Alters Trophoblast Cell Function and Modulates miR-125b-5p Expression

Air pollution is one of the largest global environmental health hazards that threaten premature mortality or morbidity. Particulate matter 10 (PM10) has been demonstrated to contribute to several human diseases via dysregulated miRNA expression. Trophoblast cells play a key role in implantation and placentation for a successful pregnancy. Nonetheless, the PM10 associated trophoblast cell functions during pregnancy and miRNA expression are still unknown. Our study showed that PM10 affected HTR-8/SVneo cell viability and also decreased cell proliferation, migration, and invasion. A high concentration of PM10 caused an increase in HTR-8/SVneo cell apoptosis. Treatment with PM10 induced inflammation through the upregulated IL-1β, IL-6, and TNF-α expression in trophoblast cells. In PM10-treated HTR-8/SVneo cells, miR-125b-5p expression was considerably increased and TXNRD1 was found to be negatively related to miR-125b-5p. Collectively, our findings revealed that PM10 could alter miR-125b-5p expression by targeting TXNRD1 and suppressing trophoblast cell functions. Additional investigations relating to the function of miR-125b-5p and its target on particulate pollution exposure in trophoblast are warranted for future biomarker or effective therapeutic approaches.

Molecular Mechanism of miR-29b on Gestational Diabetes and Its Influence on Trophoblast Cell Function

To explore the mechanism of miR-29b in gestational diabetes mellitus (GDM) and its effect on the function of trophoblast cell (TBC), the placenta tissues of 55 normal term pregnancies and 55 GDM patients were selected and rolled into control group and observation group. In the early stage, microRNA (miRNA) chips were utilized to screen the differentially expressed miRNAs in the placenta of observation group and control group. According to the microarray results of miRNAs, three differentially expressed miRNAs, namely let-7b, miR-1202, and miR-29b were selected. Then, the differences in the miR-29b level in the four groups were analyzed, namely the microRNA-29b (miR-29b minic), mini-control (minic control), microRNA-29b inhibitor (miR-29b inhibitor), and inhibitor control (inhibitor control). The results showed that miR-29b level in the placenta of observation group was substantially inferior to that of controls, with remarkable differences (P < 0.05). miR-29b level in miR-29b minic and minic control had significant changes (P < 0.01). The TBC activity of minic control was greatly superior to that of minic control, and there was considerable difference between the two (P < 0.05). The difference between miR-29b inhibitor and inhibitor control in TBC was not obvious, without considerable differences (P > 0.05). The invasion ability of miR-29b inhibitor TBC was notably superior to inhibitor control, and there were substantial differences (P < 0.05). To sum up, miR-29b had a significant inhibitory effect on the proliferation and cell activity of TBC, and can promote the apoptosis and death of TBC. Moreover, its inhibitory effect on cell migration and invasion was also suggested.

Galectins in Early Pregnancy and Pregnancy-Associated Pathologies

Galectins are a family of conserved soluble proteins defined by an affinity for β-galactoside structures present on various glycoconjugates. Over the past few decades, galectins have been recognized as important factors for successful implantation and maintenance of pregnancy. An increasing number of studies have demonstrated their involvement in trophoblast cell function and placental development. In addition, several lines of evidence suggest their important roles in feto-maternal immune tolerance regulation and angiogenesis. Changed or dysregulated galectin expression is also described in pregnancy-related disorders. Although the data regarding galectins’ clinical relevance are still at an early stage, evidence suggests that some galectin family members are promising candidates for better understanding pregnancy-related pathologies, as well as predicting biomarkers. In this review, we aim to summarize current knowledge of galectins in early pregnancy as well as in pregnancy-related pathologies.