Tumor necrosis factor-alpha suppresses the invasion of HTR-8/SVneo trophoblast cells through microRNA-145-5p-mediated downregulation of Cyr61

Extracellular vesicles affecting embryo development in vitro: a potential culture medium supplement

Extracellular vesicles (EVs) are nanometer-sized lipid bilayer vesicles released by cells, playing a crucial role in mediating cellular communication. This review evaluates the effect of EVs on early embryonic development in vitro by systematically searching the literature across three databases, Embase, PubMed, and Scopus, from inception (Embase, 1947; PubMed, 1996; and Scopus, 2004) to 30 June 2024. A total of 28 studies were considered relevant and included in this review. The EVs included in these investigations have been recovered from a range of sources, including oviduct fluid, follicular fluid, uterine fluid, seminal plasma, embryos, oviduct epithelial cells, endometrial epithelial cells, amniotic cells, and endometrial-derived mesenchymal stem cells collected primarily from mice, rabbits, cattle and pigs. This diversity in EV sources highlights the broad interest and potential applications of EVs in embryo culture systems. These studies have demonstrated that supplementation with EVs derived from physiologically normal biofluids and cells to the embryo culture medium system has positive effects on embryonic development. Conversely, EVs derived from cells under pathological conditions have shown a negative impact. This finding underscores the importance of the source and condition of EVs used in culture media. Further, the addition of EVs as a culture medium supplement holds significant therapeutic potential for optimizing in vitro embryo culture systems. In conclusion, this evaluation offers a thorough assessment of the available data on the role of EVs in embryo culture media and highlights the potential and challenges of using EVs in vitro embryo production.

Downregulation of miR-92a in Decidual Stromal Cells Suppresses Migration Ability of Trophoblasts by Promoting Macrophage Polarization

Preeclampsia (PE) is a severe pregnancy complication that accounts for about 14% of maternal deaths. Its clinical manifestations commonly include hypertension and proteinuria. However, it is largely limited in understanding its pathogenetic mechanism. In this study, we used bioinformatics to compare differential gene expressions in decidual stromal cells from PE patients and healthy donors. The result indicated that higher levels of CCL5 and CXCL2 were expressed in decidual stromal cells of PE patients compared with healthy pregnancy. The bioinformatics analysis confirmed that decidual stromal cells derived from PE patients expressed significantly lower miR-92a compared with those derived from healthy donors. Transfection of miR-92a inhibitors upregulated IL-6, CXCL2, CXCL3, CCL5, and CXCL8 expressions in decidual stromal cells. Luciferase activity assay confirmed that miR-92a directly targeted the mRNA of IRF3 whose overexpression could promote the secretion of cytokines. The flow cytometric analysis demonstrated that M1 macrophage infiltration was higher in the placentas of PE patients than in those of healthy donors. We also observed that after transfection of miR-92a inhibitor, condition medium (CM) derived from decidual stromal cells significantly promoted M1 polarization of macrophages. In addition, the transwell migration assay and flow cytometric analysis together showed that decidual stromal cell-derived CM induced macrophages to suppress the trophoblast migration and proliferation. Taken together, our result indicates that downregulation of miR-92a in decidual stromal cells promotes the macrophage polarization and suppresses the trophoblast migration and proliferation.

Micro-RNAs in Human Placenta: Tiny Molecules, Immense Power

Micro-RNAs (miRNAs) are short non-coding single-stranded RNAs that modulate the expression of various target genes after transcription. The expression and distribution of kinds of miRNAs have been characterized in human placenta during different gestational stages. The identified miRNAs are recognized as key mediators in the regulation of placental development and in the maintenance of human pregnancy. Aberrant expression of miRNAs is associated with compromised pregnancies in humans, and dysregulation of those miRNAs contributes to the occurrence and development of related diseases during pregnancy, such as pre-eclampsia (PE), fetal growth restriction (FGR), gestational diabetes mellitus (GDM), recurrent miscarriage, preterm birth (PTB) and small-for-gestational-age (SGA). Thus, having a better understanding of the expression and functions of miRNAs in human placenta during pregnancy and thereby developing novel drugs targeting the miRNAs could be a potentially promising method in the prevention and treatment of relevant diseases in future. Here, we summarize the current knowledge of the expression pattern and function regulation of miRNAs in human placental development and related diseases.

Regulatory roles of non-coding RNAs and m6A modification in trophoblast functions and the occurrence of its related adverse pregnancy outcomes

Adverse pregnancy outcomes, such as preeclampsia, gestational diabetes mellitus, fetal growth restriction, and recurrent miscarriage, occur frequently in pregnant women and might further induce morbidity and mortality for both mother and fetus. Increasing studies have shown that dysfunctions of human trophoblast are related to these adverse pregnancy outcomes. Recent studies also showed that environmental toxicants could induce trophoblast dysfunctions. Moreover, non-coding RNAs (ncRNAs) have been reported to play important regulatory roles in various cellular processes. However, the roles of ncRNAs in the regulation of trophoblast dysfunctions and the occurrence of adverse pregnancy outcomes still need to be further investigated, especially with exposure to environmental toxicants. In this review, we analyzed the regulatory mechanisms of ncRNAs and m6A methylation modification in the dysfunctions of trophoblast cells and the occurrence of adverse pregnancy outcomes and also summarized the harmful effects of environmental toxicants. In addition to DNA replication, mRNA transcription, and protein translation, ncRNAs and m6A modification might be considered as the fourth and fifth elements that regulate the genetic central dogma, respectively. Environmental toxicants might also affect these processes. In this review, we expect to provide a deeper scientific understanding of the occurrence of adverse pregnancy outcomes and to discover potential biomarkers for the diagnosis and treatment of these outcomes.

Integrative analysis of circulating microRNAs and the placental transcriptome in recurrent pregnancy loss

Recurrent pregnancy loss (RPL) is a major type of pathological pregnancy that still lacks reliable early diagnosis and effective treatment. The placenta is critical to fetal development and pregnancy success because it participates in critical processes such as early embryo implantation, vascular remodeling, and immunological tolerance. RPL is associated with abnormalities in the biological behavior of placental villous trophoblasts, resulting in aberrant placental function. MicroRNAs (miRNAs) are increasingly being recognized as essential regulators of placental development, as well as potential biomarkers. In this study, plasma miRNAs and placental messenger RNAs (mRNAs) from RPL patients and normal pregnant (NP) controls were sequenced and analyzed. Compared to those in NP controls, 108 circulating miRNAs and 1199 placental mRNAs were differentially expressed in RPL samples. A total of 140 overlapping genes (overlapping between plasma miRNA target genes and actual placental disorder genes) were identified, and functional enrichment analysis showed that these genes were mainly related to cell proliferation, angiogenesis, and cell migration. The regulatory network among miRNAs, overlapping genes, and downstream biological processes was analyzed by protein–protein interactions and Cytoscape. Moreover, enriched mRNAs, which were predictive targets of the differentially expressed plasma miRNAs miR-766-5p, miR-1285-3p, and miR-520a-3p, were accordingly altered in the placenta. These results suggest that circulating miRNAs may be involved in the pathogenesis of RPL and are potential noninvasive biomarkers for RPL.

LncRNA MEG3 alleviates PFOS induced placental cell growth inhibition through its derived miR-770 targeting PTX3

Perfluorooctane sulfonic acid (PFOS) is a persistent environmental pollutant. Exposure to PFOS has been associated with abnormal fetal development. The long non-coding RNA (lncRNA) has been showed to play a role in fetal growth restriction (FGR), preeclampsia (PE) and other pregnancy complications. Whether the lncRNA contributes to PFOS-induced toxicity in the placenta remains unknown. In this study, we investigated the function of lncRNA MEG3 and its derived miR-770 in PFOS-induced placental toxicity. Pregnant mice received gavage administration of different concentrations of PFOS (0.5, 2.5, and 12.5 mg/kg/day) from GD0 to GD17, and HTR-8/SVneo cells were treated with PFOS in the concentrations of 0, 10^-1, 1, 10 μM. We found that expression levels of miR-770 and its host gene MEG3 were reduced in mice placentas and HTR-8/SVneo cells with exposure of PFOS. A significant hypermethylation was observed at MEG3 promoter in placentas of mice gestational-treated with PFOS. We also confirmed that MEG3 and miR-770 overexpression alleviated the cell growth inhibition induced by PFOS. Furthermore, PTX3 (Pentraxin 3) was identified as the direct target of miR-770 and it was enhanced after PFOS exposure. In summary, our results suggested that MEG3 alleviate PFOS-induced placental cell inhibition through MEG3/miR-770/PTX3 axis.

MicroRNA-513c-5p is involved in the pathogenesis of preeclampsia by regulating of low-density lipoprotein receptor-associated protein 6

Background

Preeclampsia (PE) is a major cause of maternal and perinatal morbidity and mortality. Studies on the role of microRNAs (miRNAs), in the pathogenesis of PE through their effects on trophoblast function have been reported, but roles for some miRNAs including miR-513c-5p, have not been identified. We aimed to evaluate potential miRNA candidates that regulate the LRP6 mRNAand to elucidate the possible mechanism in PE. Potential miRNAs were selected by bioinformatics analysis, PCR of placenta tissues and dual luciferase reporter assay of HTR-8/SVneo cells.

Methods

A bioinformatics analysis (Gene Expression Omnibus, GEO; miRWalk) was performed to screen the possible miRNAs that participate in the pathology of PE. Placentas from patients with PE and women with a normal pregnancy were collected to detect the expression of predicted miRNAs by RT-qPCR. A dual luciferase reporter assay was used to test the binding of the potential miRNAs to LRP6. The effects of miR-513c-5p on the biological functions of HTR-8/SVneo cells were further evaluated by performing EdU staining, flow cytometry, wound healing assays and Transwell assays.

Results

GEO and miRWalk predicted 16 miRNAs that might target LRP6. Hsa-miR-371a-5p, hsa-miR-513c-5p, hsa-miR-126-3p, hsa-miR-145-5p, hsa-miR-193b-5p and hsa-miR-296-5p were 6 miRNAs upregulated in the PE placenta. LRP6 was downregulated in patients with PE compared to normal women. miR-513c-5p mimics inhibited LRP6 expression in HTR-8/SVneo cells, and LRP6 is the target gene of miR-513c-5p. miR-513c-5p mimics also inhibited invasion, migration and proliferation of HTR-8/SVneo cells but promoted their apoptosis.

Conclusions

Our study reveals that overexpression of placenta miR-513c-5p is involved in PE by regulating the biological functions of trophoblasts through the inhibition of LRP6.

Roles of noncoding RNAs in preeclampsia

Preeclampsia (PE) is an idiopathic disease that occurs during pregnancy. It comprises multiple organ and system damage, and can seriously threaten the safety of the mother and infant throughout the perinatal period. As the pathogenesis of PE is unclear, there are few specific remedies. Currently, the only way to eliminate the clinical symptoms is to terminate the pregnancy. Although noncoding RNA (ncRNA) was once thought to be the "junk" of gene transcription, it is now known to be widely involved in pathological and physiological processes, including pregnancy-related disorders. Moreover, there is growing evidence that the unbalanced expression of specific ncRNA is involved in the pathogenesis of PE. In the present review, we summarize the expression patterns of ncRNAs, i.e., microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs), and the functional mechanisms by which they affect the development of PE, and examine the clinical significance of ncRNAs as biomarkers for the diagnosis of PE. We also discuss the contributions made by genetic polymorphisms and epigenetic ncRNA regulation to PE. In the present review, we wish to explore and reinforce the clinical value of ncRNAs as noninvasive biomarkers of PE.

High Levels of Tumor Necrosis Factor-Alpha Reduce Placental Aquaporin 3 Expression and Impair in vitro Trophoblastic Cell Migration

Placentas from preeclamptic women display augmented tumor necrosis factor-alpha (TNF-α) levels with reduced expression of aquaporin 3 (AQP3). However, whether TNF-α modulates AQP3 expression remains to be elucidated. We hypothesize that elevated levels of TNF-α reduce AQP3 expression and negatively impact trophoblastic cell migration. Spontaneously hypertensive rats (SHRs) and Wistar rats (14-16 weeks) were divided into hypertensive and normotensive groups, respectively. Systolic blood pressure (SBP) was measured, and animals mated. In a third group, pregnant SHRs were treated with a TNF-α antagonist, etanercept (0.8 mg/kg, subcutaneously) on days 0, 6, 12, and 18 of pregnancy. Placentas were collected on the 20th day of pregnancy. Human placental explants, from normotensive pregnancies, were incubated with TNF-α (5, 10, and 20 ng/ml) and/or etanercept (1 μg/ml). Swan 71 cells were incubated with TNF-α (10 ng/ml) and/or etanercept (1 μg/ml) and subjected to the wound healing assay. AQP3 expression was assessed by Western blot and TNF-α levels by ELISA. SBP (mmHg) was elevated in the hypertensive group, and etanercept treatment reduced this parameter. Placental TNF-α levels (pg/ml) were higher in the hypertensive group. AQP3 expression was reduced in the hypertensive group, and etanercept treatment reversed this parameter. Explants submitted to TNF-α exposition displayed reduced expression of AQP3, and etanercept incubation reversed it. Trophoblastic cells incubated with TNF-α showed decreased cell migration and reduced AQP3 expression, and etanercept incubation ameliorated it. Altogether, these data demonstrate that high TNF-α levels negatively modulate AQP3 in placental tissue, impairing cell migration, and its relationship in a pregnancy affected by hypertension.

Effects of Maternal Obesity and Gestational Diabetes Mellitus on the Placenta: Current Knowledge and Targets for Therapeutic Interventions

Obesity and gestational diabetes mellitus (GDM) are becoming more common among pregnant women worldwide and are individually associated with a number of placenta-mediated obstetric complications, including preeclampsia, macrosomia, intrauterine growth restriction and stillbirth. The placenta serves several functions throughout pregnancy and is the main exchange site for the transfer of nutrients and gas from mother to fetus. In pregnancies complicated by maternal obesity or GDM, the placenta is exposed to environmental changes, such as increased inflammation and oxidative stress, dyslipidemia, and altered hormone levels. These changes can affect placental development and function and lead to abnormal fetal growth and development as well as metabolic and cardiovascular abnormalities in the offspring. This review aims to summarize current knowledge on the effects of obesity and GDM on placental development and function. Understanding these processes is key in developing therapeutic interventions with the goal of mitigating these effects and preventing future cardiovascular and metabolic pathology in subsequent generations.

Recent Advances of MicroRNAs, Long Non-coding RNAs, and Circular RNAs in Preeclampsia

Preeclampsia is a clinical syndrome characterized by multiple-organ dysfunction, such as maternal hypertension and proteinuria, after 20 weeks of gestation. It is a common cause of fetal growth restriction, fetal malformation, and maternal death. At present, termination of pregnancy is the only way to prevent the development of the disease. Non-coding RNAs, including microRNAs, long non-coding RNAs, and circular RNAs, are involved in important pathological and physiological functions in life cycle activities including ontogeny, reproduction, apoptosis, and cell reprogramming, and are closely associated with human diseases. Accumulating evidence suggests that non-coding RNAs are involved in the pathogenesis of preeclampsia through regulation of various physiological functions. In this review, we discuss the current evidence of the pathogenesis of preeclampsia, introduce the types and biological functions of non-coding RNA, and summarize the roles of non-coding RNA in the pathophysiological development of preeclampsia from the perspectives of oxidative stress, hypoxia, angiogenesis, decidualization, trophoblast invasion and proliferation, immune regulation, and inflammation. Finally, we briefly discuss the potential clinical application and future prospects of non-coding RNA as a biomarker for the diagnosis of preeclampsia.

Blastocyst Vitrification and Trophectoderm Biopsy Cumulatively Alter Embryonic Gene Expression in a Mouse Model

Although embryo vitrification has been used extensively in human assisted reproductive technology (ART) and animal models, epidemiologic evidence and randomized controlled trials suggest differences in pregnancy/perinatal outcomes (birthweight, risk for preterm birth, and pre-eclampsia) between babies born from fresh versus frozen embryo transfers. To address the uncertainty surrounding the effects of laboratory manipulations of embryos on clinical outcomes, we subjected mouse blastocysts to increasing levels of manipulation for transcriptome analysis. Blastocysts were randomly divided into four groups: no manipulation (control), single vitrification/thaw (1 vit), double vitrification/thaw (2 vit), and single vitrification/thaw plus trophectoderm biopsy and again vitrified/thawed (2 vit + bx). Three sets of 15 blastocysts in each group were pooled for RNA sequencing, and differentially expressed genes (DEGs) and pathways were determined by statistical analysis. Blastocysts were also stained for ZO-1 and F-actin to assess cytoskeletal integrity. Freeze/thaw and biopsy manipulation affected multiple biological pathways. The most significant differences were detected in genes related to innate immunity, apoptosis, and mitochondrial function, with the magnitude of change proportional to the extent to manipulation. Significant disruptions were also seen in cytoskeletal staining, with greater disruptions seen with greater of manipulation. Our data suggests that embryo vitrification and biopsy affect embryo gene transcription, with several identified DEGs that may have plausible mechanisms for the clinical outcomes seen in human offspring following ART. Further study is required to determine whether these alterations in gene expression are associated with clinical differences seen in children born from fresh or frozen embryo transfer.

Endometrial extracellular vesicles from women with recurrent implantation failure attenuate the growth and invasion of embryos

OBJECTIVE

To investigate whether endometrial extracellular vesicles (EVs) from patients with recurrent implantation failure (RIF) attenuate the growth and invasion of embryos.

DESIGN

In vitro experimental study.

SETTING

University-affiliated hospital.

PATIENT(S)

Ten RIF patients and seven fertile women.

INTERVENTIONS(S)

Endometrial cells isolated from endometrial tissues obtained from patients with RIF and fertile women were cultured and modulated in vitro via hormones. Conditioned medium was collected for EV isolation.

MAIN OUTCOME MEASURE(S)

EVs secreted by endometrial cells of patients with RIF (RIF-EVs) or fertile women (FER-EVs) were characterized with the use of Western blotting, nanoparticle tracking analysis, and transmission electron microscopy. EVs from the two groups were co-cultured with 2-cell murine embryos. Fluorescence-labeled EVs were used to visualize internalization by embryos. Following co-culture, blastocyst and hatching rates were calculated. Blastocysts were stained with diamidino-2-phenylindole to count the total cell number, and the hatched embryos were used to test invasion capacity.

RESULT(S)

RIF-EVs and FER-EVs are bilayered vesicles ∼100 nm in size and enriched with TSG101, Alix, and CD9. EVs were internalized within 12 hours. The blastocyst rates in the RIF-EV groups were significantly decreased compared with the FER-EV groups at 5, 10, and 20 μg/mL. The hatching rates and total cell numbers of blastocysts also were decreased significantly in the RIF-EV groups compared with the FER-EV groups at 10 and 20 μg/mL. Moreover, the invasion capacity of hatched embryos decreased significantly in the RIF-EV group.

CONCLUSION(S)

Endometrial EVs from patients with RIF attenuate the development and invasion of embryos.

The Role of LIN28-let-7-ARID3B Pathway in Placental Development

Placental disorders are a major cause of pregnancy loss in humans, and 40–60% of embryos are lost between fertilization and birth. Successful embryo implantation and placental development requires rapid proliferation, invasion, and migration of trophoblast cells. In recent years, microRNAs (miRNAs) have emerged as key regulators of molecular pathways involved in trophoblast function. A miRNA binds its target mRNA in the 3ʹ-untranslated region (3ʹ-UTR), causing its degradation or translational repression. Lethal-7 (let-7) miRNAs induce cell differentiation and reduce cell proliferation by targeting proliferation-associated genes. The oncoprotein LIN28 represses the biogenesis of mature let-7 miRNAs. Proliferating cells have high LIN28 and low let-7 miRNAs, whereas differentiating cells have low LIN28 and high let-7 miRNAs. In placenta, low LIN28 and high let-7 miRNAs can lead to reduced proliferation of trophoblast cells, resulting in abnormal placental development. In trophoblast cells, let-7 miRNAs reduce the expression of proliferation factors either directly by binding their mRNA in 3ʹ-UTR or indirectly by targeting the AT-rich interaction domain (ARID)3B complex, a transcription-activating complex comprised of ARID3A, ARID3B, and histone demethylase 4C (KDM4C). In this review, we discuss regulation of trophoblast function by miRNAs, focusing on the role of LIN28-let-7-ARID3B pathway in placental development.

Expression of ESRP1 at human fetomaternal interface and involvement in trophoblast migration and invasion

INTRODUCTION

Studies have reported that villous cytotrophoblasts (CTBs) undergo a partial epithelial to mesenchymal transition (EMT) when differentiating into extravillous cytotrophoblasts (EVTs). Epithelial splicing-regulatory protein 1 (ESRP1), an alternative splicing regulator, has been demonstrated to play important roles in the EMT process. Nevertheless, the roles of ESRP1 in the placentation remain undefined.

METHODS

ESRP1 expression in placental tissues throughout pregnancy was determined by immunohistochemistry and western blotting. The effect of ESRP1 knockdown by using small-interfering RNAs (siRNAs) on the phenotype of trophoblast cell line (HTR-8/SVneo) and villous explants was evaluated.

RESULTS

ESRP1 was localized within the CTBs, trophoblast columns, and EVTs located in the decidua. ESRP1 expression was changed during pregnancy, with the highest expression level in term placentae. ESRP1 knockdown significantly increased the migration and invasion of HTR-8/SVneo cells, as well as the outgrowth of EVTs from villous explants, without affecting cell proliferation. This enhanced effect was associated with the increased expression of N-cadherin, vimentin and CD44.

DISCUSSION

Our results suggested an important role for ESRP1 in regulating trophoblast migration and invasion during placentation.

Hyperferritinemia worsens the perinatal outcomes of conceptions of pregnancies with preeclampsia

BACKGROUND AND AIMS

To analyze the prevalence of hyperferritinemia in pregnant women with preeclampsia and its association with adverse perinatal outcomes.

METHODS

A cross-sectional study carried out in 2017 with a convenience sample of pregnant women with preeclampsia attended at a high-risk maternity hospital in Alagoas, Brazil. Socioeconomic, lifestyle, clinical and biochemical data were collected through a structured questionnaire. Type of delivery, gestational age, weight and length at birth, and Apgar score were analyzed as outcome variables. Women were dichotomized according to the serum ferritin level (150 ng/mL). Poisson regression models were used to analyze the effect of hyperferritinemia on the outcome variables. Estimates were presented as prevalence ratio with 95% confidence intervals (PR [95% CI]).

RESULTS

Based on the Fisher's exact statistical teste and in the proportions of the neonatal outcome (birth weight), with a statistical significance of 5%, the statistical power of the sample studied was 83%. Two hundred six pregnant women with preeclampsia were recruited, which 8.74% presented hyperferritinemia. Except for ferritin level, there were no differences in C-reactive protein (CRP), hemoglobin, Glutamate Oxaloacetate Transaminase (GOT) and Pyruvic Glutamic Transaminase (PGT) levels between women with or without hyperferritinemia. After adjusting for potential confounders, hyperferritinemia was associated with low birth weight (2.19 [2.13-3.89 95%CI]), low birth length (7.76 [2.52-23.8 95% CI]) and being born small for gestational age (3.14 [1.36-7.28 95% CI]).

CONCLUSION

In the presence of hyperferritinemia, preeclampsia patients were associated with a higher rate of unfavorable neonatal outcomes.

AP2γ mediated downregulation of lncRNA LINC00511 as a ceRNA suppresses trophoblast invasion by regulating miR-29b-3p/Cyr61 axis

BACKGROUND

Long noncoding RNA LINC00511 has been identified to be aberrant expression and may as a tumor oncogene in various carcinomas. However, the potential role of LINC00511 in the onset of Preeclampsia (PE) pathogenesis remains unexplored.

METHODS

Placental tissues from patients with PE were collected to detect expression levels of LINC00511 by qRT-PCR. Human HTR-8/SVneo trophoblast cell line was cultured, CCK-8 assay, wound healing assay and transwell assay were performed to determine the regulation of trophoblast biological function by LINC00511. Bioinformatics analysis, chromatin immunoprecipitation (ChIP), luciferases reporter assay were performed to verify the regulatory mechanism of LINC00511.

RESULTS

LINC00511 was aberrantly down-regulated in placental tissues of PE patients. Overexpression of LINC00511 promoted trophoblast cell proliferation, migration and invasion. The transcription factor AP2γ directly binds to the promoter region of LINC00511 to activate transcription. In addition, LINC00511 was enriched in cytoplasm and functioned as a molecular spong for miR-29b-3p, antagonizing its ability to repress Cyr61 protein translation.

CONCLUSION

This study demonstrated that AP2γ mediated downregulation of LINC00511 suppresses trophoblast invasion by regulating miR-29b-3p/ Cyr61 axis.