From animal models to patients: the role of placental microRNAs, miR-210, miR-126, and miR-148a/152 in preeclampsia

Gene therapy in preeclampsia: the dawn of a new era

Preeclampsia is a severe complication of pregnancy, affecting an estimated 4 million women annually. It is one of the leading causes of maternal and fetal mortality worldwide, and it has life-long consequences. The maternal multisystemic symptoms are driven by poor placentation, which causes syncytiotrophoblastic stress and the release of factors into the maternal bloodstream. Amongst them, the soluble fms-like tyrosine kinase-1 (sFLT-1) triggers extensive endothelial dysfunction by acting as a decoy receptor for the vascular endothelial growth factor (VEGF) and the placental growth factor (PGF). Current interventions aim to mitigate hypertension and seizures, but the only definite treatment remains induced delivery. Thus, there is a pressing need for novel therapies to remedy this situation. Notably, CBP-4888, a siRNA drug delivered subcutaneously to knock down sFLT1 expression in the placenta, has recently obtained Fast Track approval from the Food and Drug Administration (FDA) and is undergoing a phase 1 clinical trial. Such advance highlights a growing interest and significant potential in gene therapy to manage preeclampsia. This review summarizes the advances and prospects of gene therapy in treating placental dysfunction and illustrates crucial challenges and considerations for these emerging treatments.

DNA methylation landscape in pregnancy-induced hypertension: progress and challenges

Gestational hypertension (PIH), especially pre-eclampsia (PE), is a common complication of pregnancy. This condition poses significant risks to the health of both the mother and the fetus. Emerging evidence suggests that epigenetic modifications, particularly DNA methylation, may play a role in initiating the earliest pathophysiology of PIH. This article describes the relationship between DNA methylation and placental trophoblast function, genes associated with the placental microenvironment, the placental vascular system, and maternal blood and vascular function, abnormalities of umbilical cord blood and vascular function in the onset and progression of PIH, as well as changes in DNA methylation in the progeny of PIH, in terms of maternal, fetal, and offspring. We also explore the latest research on DNA methylation-based early detection, diagnosis and potential therapeutic strategies for PIH. This will enable the field of DNA methylation research to continue to enhance our understanding of the epigenetic regulation of PIH genes and identify potential therapeutic targets.

MiR-371-5p regulates trophoblast cell proliferation, migration, and invasion by directly targeting ZNF516

Despite its prevalence, preeclampsia (PE) remains unclear as to its etiology. Here, we aimed to investigate the mechanisms regulating differences in the gene expression of zinc-finger protein 516 (ZNF516) in the placenta. The expression of the placental ZNF516 gene and its association with critical clinical markers were verified, and a rigorous correlation analysis was conducted. With a dual-luciferase reporter gene assay, microRNA targeting the ZNF516 gene was predicted and confirmed. Finally, the molecular processes associated with ZNF516 were explored via microarray and bioinformatic analyses. In hypoxic conditions, miR-371-5p expression was reduced, resulting in ZNF516 expression being induced. Moreover, ZNF516 was shown to hinder trophoblast cell migration and invasion while enhancing trophoblast cell death in various in vitro cellular assays, such as cell counting kit-8, colony formation, wound healing, and Transwell assays. Our findings reveal a new regulatory network facilitated by ZNF516. ZNF516 overexpression inhibits trophoblast growth, movement, and penetration, potentially causing problems with placenta formation with the help of miR-371-5p suppression.

Are Vascular Endothelium and Angiogenesis Effective MicroRNA Biomarkers Associated with the Prediction of Early-Onset Preeclampsia (EOPE) and Adverse Perinatal Outcomes?

MicroRNA is associated with angiogenesis, invasion, proliferation, and vascular endothelial remodeling of various diseases. We aimed to investigate serum MicroRNA (miRNA) levels in preeclampsia (PE) and to determine whether any changes in miRNA levels are useful in predicting early onset preeclampsia (EOPE) and adverse perinatal outcomes. A total of 89 pregnant patients were enrolled in this prospective case-control study (55 PE and 34 healthy controls). miR-17, miR-20a, miR-20b, miR126, miR155, miR-200, miR-222, and miR-210 levels were studied in maternal serum in preeclamptic pregnant women. Multiple logistic regression analyses analyzed the risk factors which are associated with EOPE and adverse maternal outcomes. The Real-time RT-PCR method was used to determine maternal serum miRNA levels. Serum miR-17, miR-20a, miR-20b, miR126, and miR-210 levels were significantly higher in PE than the control group (p < .001, p < .001, p < .001, p < .001 and p = .047 respectively). Increased miR-17, miR-20a, and miR-20b levels were independently associated with PE (OR: 0.642, 95%Cl: 0.486-0.846, p = .002; OR: 0.899, 95%Cl: 0.811-0.996, p = .042 and OR: 0.817, 95%Cl: 0.689-0.970, p = .021). Increased miR-17 and miR-126 levels were negatively correlated with serum EOPE in PE (r = -.313, p = .020), and increased miR-210 levels were significantly positively correlated with EOPE in PE (r = .285, p = .005). Increased expression of serum miR-17, miR-20a, miR-20b, miR126, and miR-210 were found to be associated with PE, also increased expression of miR-17, miR-20a, and miR-20b were to be predicted with PE, also increased maternal serum miR-17 and miR-126 expressions were negatively correlated and increased miR-210 expression was positively correlated with EOPE in PE women.

MiR-218-5p promotes trophoblast infiltration and inhibits endoplasmic reticulum/oxidative stress by reducing UBE3A-mediated degradation of SATB1

This research evaluated the effects of miR-218-5p on trophoblast infiltration and endoplasmic reticulum/oxidative stress during preeclampsia (PE). The expression of miR-218-5p and special AT-rich sequence binding protein 1 (SATB1) in placental tissues from 25 patients with PE and 25 normal pregnant subjects was determined using qRT-PCR and western blotting. Cell invasion and cell migration were detected by performing Transwell assays and scratch assays, respectively. MMP-2/9, TIMP1/2, HIF-1α, p-eIF2α, and ATF4 expression in cells was assessed through western blotting. Intracellular reactive oxygen species were detected using 2,7-dichlorodihydrofluorescein diacetate, and intracellular malondialdehyde and superoxide dismutase activities were determined with kits. Dual-luciferase and RNA pull-down assays were performed to verify the interaction between miR-218-5p and UBE3A. Co-immunoprecipitation and western blotting were used to detect the ubiquitination levels of SATB1. A rat model of PE was established, and an miR-218-5p agomir was injected into rat placental tissues. The pathological characteristics of placental tissues were detected via HE staining, and MMP-2/9, TIMP1/2, p-eIF2α, and ATF4 expression in rat placental tissues was determined through western blotting. MiR-218-5p and SATB1 were expressed at low levels, while UBE3A was highly expressed in the placental tissues of patients with PE. The transfection of an miR-218-5p mimic, UBE3A shRNA, or an SATB1 overexpression vector into HTR-8/SVneo cells promoted trophoblast infiltration and inhibited endoplasmic reticulum/oxidative stress. It was determined that UBE3A is a target of miR-218-5p; UBE3A induces ubiquitin-mediated degradation of SATB1. In PE model rats, miR-218-5p alleviated pathological features, promoted trophoblast infiltration, and inhibited endoplasmic reticulum/oxidative stress. MiR-218-5p targeted and negatively regulated UBE3A expression to inhibit ubiquitin-mediated SATB1 degradation, promote trophoblast infiltration, and inhibit endoplasmic reticulum/oxidative stress.

Is There a Relationship between Adverse Pregnancy Outcomes and Future Development of Atherosclerosis?

Cardiovascular disease is one of the main death causes globally. Effective cardiovascular risk management requires a thorough understanding of the mechanisms underlying the disorder. Establishing early markers of the disease allows a timely intervention and prevention of further atherosclerosis development. Multiple studies confirm the correlation between pregnancy disorders and cardiovascular disease in the postpartum period. Moreover, over 30% of women experience adverse pregnancy outcomes. Thus, the examination of the links between these conditions and atherosclerotic cardiovascular disease may help to identify gender-specific risk factors. In this review, we will explore the association between several adverse pregnancy outcome conditions and atherosclerosis. The current analysis is based on the data from several recent studies on the mechanisms behind gestational diabetes, hypertensive disorders of pregnancy, miscarriages, and stillbirths and their implications for the female cardiovascular system.

From Molecules to Imaging: Assessment of Placental Hypoxia Biomarkers in Placental Insufficiency Syndromes

Placental hypoxia poses significant risks to both the developing fetus and the mother during pregnancy, underscoring the importance of early detection and monitoring. Effectively identifying placental hypoxia and evaluating the deterioration in placental function requires reliable biomarkers. Molecular biomarkers in placental tissue can only be determined post-delivery and while maternal blood biomarkers can be measured over time, they can merely serve as proxies for placental function. Therefore, there is an increasing demand for non-invasive imaging techniques capable of directly assessing the placental condition over time. Recent advancements in imaging technologies, including photoacoustic and magnetic resonance imaging, offer promising tools for detecting and monitoring placental hypoxia. Integrating molecular and imaging biomarkers may revolutionize the detection and monitoring of placental hypoxia, improving pregnancy outcomes and reducing long-term health complications. This review describes current research on molecular and imaging biomarkers of placental hypoxia both in human and animal studies and aims to explore the benefits of an integrated approach throughout gestation.

Micro RNA210 expression in pregnancies with preeclampsia

Preeclampsia is one of the major causes of perinatal mortality and morbidity even in developed countries, the aetiology of which is not yet understood completely. In recent times, mi RNAs have gained prominence as regulators of the expressions of their target genes in health and pathological condition. mi RNA210, one of the important hypoxamirs, is reported to be a regulator of many cellular mechanisms including cell division, differentiation, apoptosis, cell cycle regulation, mitochondrial function, metabolism etc. Since hypoxia is the microenvironment that prevailed in preeclampsia it is worth full to see the expression pattern of mi RNA 210 as an attempt to unearth the preeclampsia pathogenesis. The placental tissue is collected from age-matched control and preeclamptic patients after strictly applying the inclusion and exclusion criteria. The present result shows 2.7 fold-up regulation of miRNA210 in preeclampsia in rt PCR study, the role of which need to be studied further to understand the pathogenesis of preeclampsia.

Unique microRNA expression profiles in plasmic exosomes from intrahepatic cholestasis of pregnancy

BACKGROUND

Intrahepatic cholestasis of pregnancy (ICP) is strongly associated with an increased risk of adverse perinatal outcomes. Total bile acid (TBA) levels in the late second or third trimester are a major factor in the diagnosis. Here, we sought to establish the miRNA expression profile of plasm exosomes of ICP and identify possible biomarkers for the diagnosis of ICP.

METHODS

This case-control study involved 14 ICP patients as the experimental group and 14 healthy pregnant women as the control group. Electron microscopy was used to observe the presence of exosomes in plasma. Nanosight and Western blotting of CD63 was used to assess exosome quality. Among them, three ICP patients and three controls were used for isolation plasmic exosome and preliminary miRNA array analysis. The Agilent miRNA array was utilized to dynamically monitor the miRNA expression in plasmic exosomes of included patients in the first trimester(T1), second trimester (T2), third trimester (T3), and delivery (T4). Then, Quantitative real-time Polymerase chain reaction was used to identify and validate differentially expressed miRNAs in plasma-derived exosomes.

RESULTS

The expression levels of hsa-miR-940, hsa-miR-636, and hsa-miR-767-3p in plasma-derived exosomes of ICP patients were significantly higher than those of healthy pregnant women. Besides, these three miRNAs were also significantly up-regulated at the plasma, placental, and cellular levels (P < 0.05). The diagnostic accuracy of hsa-miR-940, hsa-miR-636, and hsa-miR-767-3p was further evaluated by the ROC curve, the area under the curve (AUC) values for each were 0.7591, 0.7727, and 0.8955, respectively.

CONCLUSIONS

We identified three differentially expressed miRNAs in the plasma exosomes of ICP patients. Hence, hsa-miR-940, hsa-miR-636, and hsa-miR-767-3p may be potential biomarkers for enhancing the diagnosis and prognosis of ICP.

Circulating Non-coding RNAs and Exosomes: Liquid Biopsies for Monitoring Preeclampsia

Preeclampsia (PE) remains a leading cause of maternal and fetal mortality, due to ineffective treatment and diagnostic strategies, compounded by the lack of clarity on the etiology of the disorder. The early prediction or accurate diagnosis of PE is a concern of researchers. Liquid biopsy can be analyzed for cell-free nucleic acids and exosomes. Because circulating non-coding RNAs (ncRNAs) and peripheral blood exosomes can be detected in the peripheral blood of women in early pregnancy, these vesicles and their contents have become the focus of research on early predictive and diagnostic biomarkers for preeclampsia. In this review, we focus on recent studies addressing the roles of circulating ncRNAs and exosomes in PE, with particular attention paid to the potential application value of placenta-derived exosomes and circulating ncRNAs as PE-specific biomarkers.

MicroRNAs in septic acute kidney injury

Sepsis is a potentially fatal complication of burns and trauma that can cause acute kidney injury (AKI) with substantial morbidity and mortality, but this disease is poorly understood. Despite medical advances, effective therapeutic regimens for septic AKI remain uncommon. MicroRNAs (miRNAs) are endogenous non-coding RNAs that influence the translation of target messenger RNAs in a variety of biological processes. Emerging evidence has shown that miRNAs are intimately associated with septic AKI. The goal of this review was to summarize recent advances in the profound understanding of the functional role of miRNAs in septic AKI, as well as to provide new insights into miRNAs as feasible biomarkers and therapeutic targets for septic AKI.

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.

Small extracellular vesicles derived from hypoxic mesenchymal stem cells promote vascularized bone regeneration through the miR-210-3p/EFNA3/PI3K pathway

Angiogenesis is closely coupled with osteogenesis and has equal importance. Thus, promoting angiogenesis during the bone repair process is vital for ideal bone regeneration. As important mediators of cell-cell communication and biological homeostasis, mesenchymal stem cell-derived small extracellular vesicles (MSC-sEVs) have been proved to be highly involved in bone and vascular regeneration. Because hypoxia microenvironment promotes the proangiogenic activity of MSCs, in the present study, we investigate the effect and underlying molecular mechanisms of sEVs from hypoxia-preconditioned MSCs (hypo-sEVs) on angiogenesis and develop an effective strategy to promote vascularized bone regeneration. Compared to sEVs from normoxia MSCs (nor-sEVs), hypo-sEVs promoted the proliferation, migration, and angiogenesis of HUVECs and ultimately enhanced bone regeneration and new blood vessel reconstruction in a critical-size calvarial bone defect model. miRNA sequence and the verified results showed that miR-210-3p in hypo-sEVs was increased via HIF-1α under hypoxia. The upregulated miR-210-3p in hypo-sEVs promoted angiogenesis by downregulating EFNA3 expression and enhancing the phosphorylation of the PI3K/AKT pathway. Thus, this study suggests a successful strategy to enhance vascularized bone regeneration by utilizing hypo-sEVs via the miR-210-3p/EFNA3/PI3K/AKT pathway. STATEMENT OF SIGNIFICANCE: Considering the significance of vascularization in ideal bone regeneration, strategies to promote angiogenesis during bone repair are required. Hypoxia microenvironment can promote the proangiogenic potential of mesenchymal stem cells (MSCs). Nonetheless, the therapeutic effect of small extracellular vesicles (sEVs) from hypoxia-preconditioned MSCs on cranio-maxillofacial bone defect remains unknown, and the underlying mechanism is poorly understood. This study shows that hypo-sEVs significantly enhance the proliferation, migration, and angiogenesis of HUVECs as well as promote vascularized bone formation. Moreover, this work indicates that HIF-1α can induce overexpression of miR-210-3p under hypoxia, and miR-210-3p can hinder EFNA3 expression and subsequently activate the PI3K/AKT pathway. The application of hypo-sEVs provides a facile and promising strategy to promote vascularized bone regeneration in a critical-size bone defect model.

Investigation of Sperm and Seminal Plasma Candidate MicroRNAs of Bulls with Differing Fertility and In Silico Prediction of miRNA-mRNA Interaction Network of Reproductive Function

Simple Summary

The objective of this study was to identify differentially expressed (DE) sperm and seminal plasma microRNAs (miRNAs) in high- and low-fertile Holstein bulls (four bulls per group), integrate miRNAs to their target genes, and categorize target genes based on predicted biological processes. Out of 84 bovine-specific, prioritized miRNAs analyzed by RT-PCR, 30 were differentially expressed in high-fertile sperm and seminal plasma compared to low-fertile sperm and seminal plasma, respectively (p ≤ 0.05, fold regulation ≥5 magnitudes). Interestingly, expression levels of DE-miRNAs in sperm and seminal plasma followed a similar pattern. Highly scored integrated genes of DE-miRNAs predicted various biological and molecular functions, cellular process, and pathways. Further in silico analysis revealed categorized genes may have a plausible association with pathways regulating sperm structure and function, fertilization, and embryo and placental development. In conclusion, highly DE-miRNAs in bovine sperm and seminal plasma could be used as a tool for predicting reproductive functions. Since the identified miRNA-mRNA interactions were mostly based on predictions from public databases, the causal regulations of miRNA-mRNA and the underlying mechanisms require further functional characterization in future studies.

Abstract

Recent advances in high-throughput in silico techniques portray experimental data as exemplified biological networks and help us understand the role of individual proteins, interactions, and their biological functions. The objective of this study was to identify differentially expressed (DE) sperm and seminal plasma microRNAs (miRNAs) in high- and low-fertile Holstein bulls (four bulls per group), integrate miRNAs to their target genes, and categorize the target genes based on biological process predictions. Out of 84 bovine-specific, prioritized miRNAs analyzed by RT-PCR, 30 were differentially expressed in high-fertile sperm and seminal plasma compared to low-fertile sperm and seminal plasma, respectively (p ≤ 0.05, fold regulation ≥ 5 magnitudes). The expression levels of DE-miRNAs in sperm and seminal plasma followed a similar pattern. Highly scored integrated genes of DE-miRNAs predicted various biological and molecular functions, cellular process, and pathways. Further, analysis of the categorized genes showed association with pathways regulating sperm structure and function, fertilization, and embryo and placental development. In conclusion, highly DE-miRNAs in bovine sperm and seminal plasma could be used as a tool for predicting reproductive functions. Since the identified miRNA-mRNA interactions were mostly based on predictions from public databases, the causal regulations of miRNA-mRNA and the underlying mechanisms require further functional characterization in future studies.

miR-24-3p regulation of retinol binding protein 4 in trophoblast biofunction and preeclampsia

Preeclampsia (PE) is a pregnancy-related disease and is the leading cause of overall maternal mortality and morbidity. Our previous studies have shown that the serum and placental levels of retinol-binding protein 4 (RBP4) in PE are reduced. Our previous bioinformatics analysis predicted that RBP4 is a target of the microRNA miRNA-24-3p. In this study, our database analysis also indicated that RBP4 is a miR-24-3p target. Compared with that of the normal placenta, the expression level of RBP4 in human PE placenta was significantly reduced, and miR-24-3p was highly expressed. In HTR-8/SVneo cells, transfection of exogenous miR-24-3p reduced RBP4 expression. A dual-luciferase reporter assay validated RBP4 as a direct target of miR-24-3p, indicating that it directly binds to the 3'-untranslated region of RBP4. This binding was reversed by a mutation in the microRNA-binding site. Transwell invasion experiments and CCK8 assay showed that inhibitory effect of miR-24-3p reduced RBP4 mediated HTR-8/SVneo cell invasion and proliferation. These data provide a new overarching perspective on the physiological role played by miR-24-3p in regulating RBP4 during trophoblast dysfunction and PE development.

Small Non-Coding RNAs in the Human Placenta: Regulatory Roles and Clinical Utility

The placenta is a vital organ formed during pregnancy, and being the interface between the mother and fetus, it is paramount that placental functioning is strictly controlled. Gene expression in the placenta is finely tuned-with aberrant expression causing placental pathologies and inducing stress on both mother and fetus. Gene regulation is brought upon by several mechanisms, and small non-coding RNAs (sncRNAs) have recently been appreciated for their contribution in gene repression. Their dysregulation has been implicated in a range of somatic and inherited disorders, highlighting their importance in maintaining healthy organ function. Their specific roles within the placenta, however, are not well understood, and require further exploration. To this end, we summarize the mechanisms of microRNAs (miRNAs), Piwi-interacting RNAs (piRNAs), small nuclear RNAs (snRNAs), small nucleolar RNAs (snoRNAs), and transfer RNAs (tRNAs), their known contributions to human placental health and disease, the relevance of sncRNAs as promising biomarkers throughout pregnancy, and the current challenges faced by placental sncRNA studies.

A novel regulatory mechanism network mediated by lncRNA TUG1 that induces the impairment of spiral artery remodeling in Preeclampsia

Preeclampsia (PE) is associated with maternal and fetal perinatal morbidity and mortality, which brings tremendous suffering and imposes an economic burden worldwide. The failure of uterine spiral artery remodeling may be related to the abnormal function of trophoblasts and lead to the occurrence and progression of PE. Aberrant expression of long non-coding RNAs (lncRNAs) is involved in the failure of uterine spiral artery remodeling. However, the regulation of lncRNA expression in PE is poorly characterized. Here, we reported that hypoxia-induced microRNA (miR)-218 inhibited the expression of lncRNA TUG1 by targeting FOXP1. Further RNA sequencing and mechanism analysis revealed that silencing of TUG1 increased the expression of DNA demethylase TET3 and proliferation-related DUSP family, including DUSP2, DUSP4, and DUSP5, via binding to SUV39H1 in the nucleus. Moreover, TUG1 modulated the DUSP family in vitro through a TET3-mediated epigenetic mechanism. Taken together, our results unmask a new regulatory network mediated by TUG1 as an essential determinant of the pathogenesis of PE, which regulates cell growth and possibly the occurrence and development of other diseases.

Identification of Circular RNA circ_0017068 as a Regulator of Proliferation and Apoptosis in Trophoblast Cells by miR-330-5p/XIAP Axis

Preeclampsia (PE) is a major and serious complication of pregnancy. Circular RNAs (circRNAs) have been implicated in the initiation and progression of PE. In this paper, we explored the precise actions of circ_0017068 in trophoblast cell functional properties. Ribonuclease (RNase) R, and Actinomycin D treatments were used to characterize circ_0017068. The levels of circ_0017068, microRNA (miR)-330-5p and X-linked inhibitor of apoptosis protein (XIAP) were measured by quantitative real-time polymerase chain reaction (qRT-PCR) or western blot analysis. Cell proliferation, cell cycle progression, and apoptosis were gauged by the Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), and flow cytometry assays, respectively. Direct relationship between miR-330-5p and circ_0017068 or XIAP was validated by dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. Our data showed that circ_0017068 was downregulated in PE placental samples. Enforced expression of circ_0017068 promoted HTR-8/SVneo cell proliferation, cycle progression, and suppressed apoptosis, while silencing of circ_0017068 exhibited opposite effects. Mechanistically, circ_0017068 targeted miR-330-5p, and circ_0017068 regulated proliferation, cycle progression, and apoptosis of HTR-8/SVneo cells through miR-330-5p. Moreover, XIAP was identified as a direct and functional target of miR-330-5p. Furthermore, circ_0017068 operated as a post-transcriptional regulator of XIAP expression through miR-330-5p. Our study identifies circ_0017068 as an important regulator of the proliferation and apoptosis of HTR-8/SVneo trophoblast cells at least in part by miR-330-5p-dependent regulation of XIAP, highlighting circ_0017068 as a potential therapeutic agent for PE treatment.

Circ_0037078 promotes trophoblast cell proliferation, migration, invasion and angiogenesis by miR-576-5p/IL1RAP axis

BACKGROUND

Preeclampsia (PE) is a common hypertensive disorder of pregnancy. Recent studies have suggested that circular RNAs (circRNAs) play a pathological role in PE. Herein, this study aimed to investigate the action and mechanism of circ_0037078 in PE process.

METHODS

The quantitative real-time PCR (qRT-PCR) and Western blot were used to determine the expression levels of RNAs and genes. Cell proliferation, migration, invasion and angiogenesis were evaluated by using cell counting kit-8 (CCK-8), colony formation, transwell, and tube formation assays, respectively. The target relation between miR-576-5p and IL1RAP (Interleukin-1 receptor accessory protein) and circ_0037078 was predicted by bioinformatics analysis and verified by dual-luciferase reporter and RNA immunoprecipitation (RIP) assays.

RESULTS

Circ_0037078 expression was higher in placental tissues of patients with PE than that of normal control. Knockdown of circ_0037078 led to an enhancement of the proliferation, migration, invasion, and angiogenesis in trophoblast cells. Mechanistically, circ_0037078 acted as a sponge for miR-576-5p, thus elevating the expression of IL1RAP, which was targeted by IL1RAP. Further rescue experiments suggested that miR-576-5p inhibition reversed the effects of circ_0037078 knockdown on above behaviors of trophoblast cells. Moreover, miR-576-5p overexpression enhanced the proliferative, migratory, invasive, angiogenic phenotypes of trophoblast cells, which were attenuated by IL1RAP up-regulation.

CONCLUSION

Circ_0037078 knockdown promotes trophoblast cell proliferation, migration, invasion, and angiogenesis in vitro by miR-576-5p/IL1RAP axis, providing a novel insight into the etiology of PE.

Significance of Sex Differences in ncRNAs Expression and Function in Pregnancy and Related Complications

In the era of personalized medicine, fetal sex-specific research is of utmost importance for comprehending the mechanisms governing pregnancy and pregnancy-related complications. In recent times, noncoding RNAs (ncRNAs) have gained increasing attention as critical players in gene regulation and disease pathogenesis, and as candidate biomarkers in human diseases as well. Different types of ncRNAs, including microRNAs (miRNAs), piwi-interacting RNAs (piRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs), participate in every step of pregnancy progression, although studies taking into consideration fetal sex as a central variable are still limited. To date, most of the available data have been obtained investigating sex-specific placental miRNA expression. Several studies revealed that miRNAs regulate the (patho)-physiological processes in a sexually dimorphic manner, ensuring normal fetal development, successful pregnancy, and susceptibility to diseases. Moreover, the observation that ncRNA profiles differ according to cells, tissues, and developmental stages of pregnancy, along with the complex interactions among different types of ncRNAs in regulating gene expression, strongly indicates that more studies are needed to understand the role of sex-specific ncRNA in pregnancy and associated disorders.

Analysis of Expression Profiles of CircRNA and MiRNA in Oviduct during the Follicular and Luteal Phases of Sheep with Two Fecundity (FecB Gene) Genotypes

CircRNA and miRNA, as classes of non-coding RNA, have been found to play pivotal roles in sheep reproduction. There are many reports of circRNA and miRNA in the ovary and uterus, but few in the oviduct. In this study, RNA-Seq was performed to analyze the expression profile of circRNA and miRNA in the oviduct during the follicular phase and luteal phase of sheep with FecB^BB and FecB⁺⁺ genotypes. The results showed that a total of 3223 circRNAs and 148 miRNAs were identified. A total of 15 DE circRNAs and 40 DE miRNAs were found in the comparison between the follicular phase and luteal phase, and 1 DE circRNA and 18 DE miRNAs were found in the comparison between the FecB^BB genotype and FecB⁺⁺ genotype. GO and KEGG analyses showed that the host genes of DE circRNAs were mainly enriched in the Rap1 signaling pathway, PI3K-Akt signaling pathway and neuroactive ligand-receptor interactions. Novel_circ_0004065, novel_circ_0005109, novel_circ_0012086, novel_circ_0014274 and novel_circ_0001794 were found to be possibly involved in the oviductal reproduction process. GO and KEGG analyses showed that the target genes of DE miRNAs were mainly enriched in insulin secretion, the cAMP signaling pathway, the cGMP-PKG signaling pathway, the Rap1 signaling pathway and the TGF-β signaling pathway, and the target genes LPAR1, LPAR2, FGF18, TACR3, BMP6, SMAD4, INHBB, SKP1 and TGFBR2 were found to be associated with the reproductive process. Miranda software was used to identify 27 miRNAs that may bind to 13 DE circRNAs, including miR-22-3p (target to novel_circ_0004065), miR-127, miR-136 (target to novel_circ_0000417), miR-27a (target to novel_circ_0014274) and oar-miR-181a (target to novel_circ_ 0017815). The results of this study will help to elucidate the regulatory mechanisms of circRNAs and miRNAs in sheep reproduction. Our study, although not establishing direct causal relationships of the circRNA and miRNA changes, enriches the sheep circRNA and miRNA database and provides a basis for further studies on sheep reproduction.

MicroRNAs targeting VEGF are related to vascular dysfunction in preeclampsia

In preeclampsia (PE), pre-existent maternal endothelial dysfunction leads to impaired placentation and vascular maladaptation. The vascular endothelial growth factor (VEGF) pathway is essential in the placentation process and VEGF expression is regulated through post-transcriptional modification by microRNAs (miRNAs). We investigated the expression of VEGF-related circulating miR-16, miR-29b, miR-126, miR-155 and miR-200c in PE vs healthy pregnancies (HPs), and their relation with vascular function, oxidative stress (OS) and systemic inflammation. In this case-control study, 24 women with early PE (<34 weeks) were compared with 30 women with HP. Circulating microRNA levels (RT-qPCR), OS and systemic inflammation were assessed in plasma samples (PE 29.5 vs HP 25.8 weeks) and related to extensive in vivo vascular function (flow-mediated dilatation (FMD), modified FMD (mFMD), carotid-femoral pulse wave velocity (CF-PWV), heart rate corrected augmentation index (AIx75) and reactive hyperemia index (RHI)). FMD, CF-PWV, AIx75 and RHI were all significantly impaired in PE (P<0.05). PE patients had reduced levels of miR-16 (5.53 ± 0.36 vs 5.84 ± 0.61) and increased levels of miR-200c (1.34 ± 0.57 vs 0.97 ± 0.68) (P<0.05). Independent of age and parity, miR-16 was related to impaired FMD (β 2.771, 95% C.I.: 0.023-5.519, P=0.048) and mFMD (β 3.401, 95% C.I.: 0.201-6.602, P=0.038). Likewise, miR-200c was independently associated with CF-PWV (β 0.513, 95% C.I.: 0.034-0.992, P=0.036). In conclusion, circulating levels of miR-16 were lower in PE, which correlated with impaired endothelial function. Circulating miR-200c was increased in PE and correlated with higher arterial stiffness. These findings suggest a post-transcriptional dysregulation of the VEGF pathway in PE and identify miR-16 and miR-200c as possible diagnostic biomarkers for PE.

Comparing the Predictivity of Human Placental Gene, microRNA, and CpG Methylation Signatures in Relation to Perinatal Outcomes

Molecular signatures are being increasingly integrated into predictive biology applications. However, there are limited studies comparing the overall predictivity of transcriptomic vs. epigenomic signatures in relation to perinatal outcomes. This study set out to evaluate mRNA and microRNA (miRNA) expression and cytosine-guanine dinucleotide (CpG) methylation signatures in human placental tissues and relate these to perinatal outcomes known to influence maternal/fetal health; namely, birth weight, placenta weight, placental damage, and placental inflammation. The following hypotheses were tested: (1) different molecular signatures will demonstrate varying levels of predictivity towards perinatal outcomes, and (2) these signatures will show disruptions from an example exposure (i.e., cadmium) known to elicit perinatal toxicity. Multi-omic placental profiles from 390 infants in the Extremely Low Gestational Age Newborns cohort were used to develop molecular signatures that predict each perinatal outcome. Epigenomic signatures (i.e., miRNA and CpG methylation) consistently demonstrated the highest levels of predictivity, with model performance metrics including R^2 (predicted vs. observed) values of 0.36-0.57 for continuous outcomes and balanced accuracy values of 0.49-0.77 for categorical outcomes. Top-ranking predictors included miRNAs involved in injury and inflammation. To demonstrate the utility of these predictive signatures in screening of potentially harmful exogenous insults, top-ranking miRNA predictors were analyzed in a separate pregnancy cohort and related to cadmium. Key predictive miRNAs demonstrated altered expression in association with cadmium exposure, including miR-210, known to impact placental cell growth, blood vessel development, and fetal weight. These findings inform future predictive biology applications, where additional benefit will be gained by including epigenetic markers.

The predictive value of microRNA in early hypertensive disorder complicating pregnancy (HDCP)

OBJECTIVE

To examine the predictive value of microRNA (miRNA) in hypertensive disorder complicating pregnancy (HDCP).

METHODS

102 pregnant women with HDCP admitted to our hospital from March 2017 to June 2019 were recruited as the study cohort and randomly divided into an HDCP group, a mild preeclampsia group, and a severe preeclampsia group, with 34 patients in each group. In addition, 34 healthy pregnant women who underwent pregnancy tests in our hospital were recruited as the normal group. The relative expressions of plasma miR-19a, miR-126, and miRNA-210 in were measured. A Pearson correlation analysis was used to analyze the correlations between the miR-19a, miR-181b, and miRNA-210 expressions and the severity of HDCP. Receiver operating characteristic (ROC) curves were used to evaluate the diagnostic efficacy of the miR-19a, miR-126, and miRNA-210 expressions.

RESULTS

The miR-19a and miRNA-210 expressions were higher in the HDCP group, the mild preeclampsia group, and the severe preeclampsia group than they were in the normal group, and the miR-126 expression was lower (all P<0.05). The miR-19a, miR-126, and miRNA-210 expressions were different among the four groups (P<0.05). The miR-19a and miRNA-210 expression levels in the severe preeclampsia group were higher than they were in the HDCP group, and the miR-126 expression was lower (P<0.05). A Pearson correlation analysis showed the miR-19a and miR-210 levels in the HDCP patients were positively correlated with the severity of the disease (P<0.05), and the miR-126 level is negatively correlated with disease severity (P<0.05). Our ROC curve analysis demonstrated that the miR-19a, miR-126, and miR-210 levels have a predictive value for HDCP. The areas under the curve were 0.800, 0.633, and 0.723, the sensitivities were 81.2%, 71.4%, and 80.2%, and the specificities were 73.5%, 67.5%, 81.5%. Additionally, the area under the curve of the combination of the three was 0.896, and the sensitivity and specificity were 90.5% and 93.9% respectively.

CONCLUSION

miR-19a, miR-126, and miR-210 are strongly connected to the severity of HDCP and can be used as a sensitive indicator to predict HDCP patients clinically.

Expression and significance of microRNA-126 and VCAM-1 in placental tissues of women with early-onset preeclampsia

Objective

To investigate the expression of microRNA‐126 (miR‐126) and vascular endothelial cell adhesion molecule‐1 (VCAM‐1) in the placental tissues of women with early‐onset preeclampsia (EOPE) and their effects on trophoblast invasion.

Materials and Methods

The placental tissues of 30 pregnant women with EOPE who delivered in the Third Affiliated Hospital of Zhengzhou University from November 2019 to May 2020 were selected as the preeclampsia (PE) group, and the placental tissues of 30 healthy pregnant women with normal prenatal examination were selected as the normal group. Immunohistochemistry was used to localize VCAM‐1 in placental tissues，the expression of miR‐126 and VCAM‐1 in placenta tissues of two groups and HTR‐8/SVneo cells transfected with miR‐126 were detected by real‐time polymerase chain reaction (RT‐PCR) and Western blot, and the correlation between them was analyzed. The invasion ability of cells transfected with miR‐126 was observed by Transwell invasion test.

Results

Compared with the normal group, the expression of miR‐126 was higher and VCAM‐1 was lower in the placental tissues of the PE group, and the difference were statistically significant (p < 0.01). Moreover, VCAM‐1 was negatively correlated with the expression of miR‐126 (r = −0.391, p < 0.05). In vitro experiment, the expression level of VCAM‐1 in miR‐126 mimics transfection group was decreased, and the expression level of VCAM‐1 in miR‐126 inhibitor transfection group was increased; the invasion ability of HTR‐8/SVneo cells transfected with miR‐126 mimics was decreased, and the invasion ability of HTR‐8/SVneo cells transfected with miR‐126 inhibitor was enhanced.

Conclusion

There was a negative correlation between the expression of miR‐126 and VCAM‐1 in EOPE.MiR‐126 and VCAM‐1 may participate in the occurrence and development of EOPE by affecting the invasion ability of trophoblast cells.

Peroxisome Proliferator-Activated Receptors (PPAR), fatty acids and microRNAs: Implications in women delivering low birth weight babies

Low birth weight (LBW) babies are associated with neonatal morbidity and mortality and are at increased risk for noncommunicable diseases (NCDs) in later life. However, the molecular determinants of LBW are not well understood. Placental insufficiency/dysfunction is the most frequent etiology for fetal growth restriction resulting in LBW and placental epigenetic processes are suggested to be important regulators of pregnancy outcome. Early life exposures like altered maternal nutrition may have long-lasting effects on the health of the offspring via epigenetic mechanisms like DNA methylation and microRNA (miRNA) regulation. miRNAs have been recognized as major regulators of gene expression and are known to play an important role in placental development. Angiogenesis in the placenta is known to be regulated by transcription factor peroxisome proliferator-activated receptor (PPAR) which is activated by ligands such as long-chain-polyunsaturated fatty acids (LCPUFA). In vitro studies in different cell types indicate that fatty acids can influence epigenetic mechanisms like miRNA regulation. We hypothesize that maternal fatty acid status may influence the miRNA regulation of PPAR genes in the placenta in women delivering LBW babies. This review provides an overview of miRNAs and their regulation of PPAR gene in the placenta of women delivering LBW babies.Abbreviations: AA - Arachidonic Acid; Ago2 - Argonaute2; ALA - Alpha-Linolenic Acid; ANGPTL4 - Angiopoietin-Like Protein 4; C14MC - Chromosome 14 miRNA Cluster; C19MC - Chromosome 19 miRNA Cluster; CLA - Conjugated Linoleic Acid; CSE - Cystathionine γ-Lyase; DHA - Docosahexaenoic Acid; EFA - Essential Fatty Acids; E2F3 - E2F transcription factor 3; EPA - Eicosapentaenoic Acid; FGFR1 - Fibroblast Growth Factor Receptor 1; GDM - Gestational Diabetes Mellitus; hADMSCs - Human Adipose Tissue-Derived Mesenchymal Stem Cells; hBMSCs - Human Bone Marrow Mesenchymal Stem Cells; HBV - Hepatitis B Virus; HCC - Hepatocellular Carcinoma; HCPT - Hydroxycamptothecin; HFD - High-Fat Diet; Hmads - Human Multipotent Adipose-Derived Stem; HSCS - Human Hepatic Stellate Cells; IUGR - Intrauterine Growth Restriction; LA - Linoleic Acid; LBW - Low Birth Weight; LCPUFA - Long-Chain Polyunsaturated Fatty Acids; MEK1 - Mitogen-Activated Protein Kinase 1; MiRNA - MicroRNA; mTOR - Mammalian Target of Rapamycin; NCDs - NonCommunicable Diseases; OA - Oleic Acid; PASMC - Pulmonary Artery Smooth Muscle Cell; PLAG1 - Pleiomorphic Adenoma Gene 1; PPAR - Peroxisome Proliferator-Activated Receptor; PPARα - PPAR alpha; PPARγ - PPAR gamma; PPARδ - PPAR delta; pre-miRNA - precursor miRNA; RISC - RNA-Induced Silencing Complex; ROS - Reactive Oxygen Species; SAT - Subcutaneous Adipose Tissue; WHO - World Health Organization.

MicroRNA-126 suppresses the invasion of trophoblast-model JEG-3 cells by targeting LIN28A

Inadequate trophoblast invasion and impaired trophoblast-induced vascular remodeling are features of preeclampsia. In this context, an angiogenesis-related microRNA, miR-126, is abnormally expressed in preeclampsia placentas, but its role in trophoblast development remains unclear. The purpose of this study was to investigate the roles of miR-126 in the proliferation, migration, and invasion processes of trophoblast cells using the human choriocarcinoma-derived JEG-3 cell line as a model. The mRNA expression profiling of JEG-3 cells with and without miR-126 overexpression, in combination with bioinformatics analysis, identified LIN28A as a putative target of miR-126. The results of real-time RT-PCR and luciferase assay were consistent with this idea. Overexpression of miR-126 in JEG-3 cells decreased the invasive ability of the cells without affecting proliferation or migration. The invasiveness of JEG-3 cells was significantly reduced to a similar extent by knockdown of LIN28A with siRNA and by miR-126-overexpression-induced downregulation of LIN28A, although the level of LIN28A protein was much lower in the siLIN28A-transfected cells. These results indicate that miR-126 suppresses JEG-3 cell invasion by targeting LIN28A, and suggest that miR-126-mediated downregulation of LIN28A might contribute to the onset/deterioration of preeclampsia.

The promise of placental extracellular vesicles: models and challenges for diagnosing placental dysfunction in utero†

Monitoring the health of a pregnancy is of utmost importance to both the fetus and the mother. The diagnosis of pregnancy complications typically occurs after the manifestation of symptoms, and limited preventative measures or effective treatments are available. Traditionally, pregnancy health is evaluated by analyzing maternal serum hormone levels, genetic testing, ultrasonographic imaging, and monitoring maternal symptoms. However, researchers have reported a difference in extracellular vesicle (EV) quantity and cargo between healthy and at-risk pregnancies. Thus, placental EVs (PEVs) may help to understand normal and aberrant placental development, monitor pregnancy health in terms of developing placental pathologies, and assess the impact of environmental influences, such as infection, on pregnancy. The diagnostic potential of PEVs could allow for earlier detection of pregnancy complications via noninvasive sampling and frequent monitoring. Understanding how PEVs serve as a means of communication with maternal cells and recognizing their potential utility as a readout of placental health have sparked a growing interest in basic and translational research. However, to date, PEV research with animal models lags behind human studies. The strength of animal pregnancy models is that they can be used to assess placental pathologies in conjunction with isolation of PEVs from fluid samples at different time points throughout gestation. Assessing PEV cargo in animals within normal and complicated pregnancies will accelerate the translation of PEV analysis into the clinic for potential use in prognostics. We propose that appropriate animal models of human pregnancy complications must be established in the PEV field.

Elevated MicroRNA 183 Impairs Trophoblast Migration and Invasiveness by Downregulating FOXP1 Expression and Elevating GNG7 Expression during Preeclampsia

Preeclampsia (PE) is a hypertensive disorder of uncertain etiology that is the leading cause of maternal and fetal morbidity or mortality. The dysregulation of microRNAs (miRNAs) has been highlighted as a potential factor involved in the development of PE. Therefore, our study investigated a novel miRNA, miRNA 183 (miR-183), and its underlying association with PE. Expression of miR-183, forkhead box P1 (FOXP1), and G protein subunit gamma 7 (GNG7) in placental tissues of patients with PE was determined. Gain- and loss-of-function experiments were conducted to explore modulatory effects of miR-183, FOXP1, and GNG7 on the viability, invasion, and angiogenesis of trophoblast cells in PE. Finally, we undertook in vivo studies to explore effects of FOXP1 in the PE model. The results revealed suppressed expression of FOXP1 and significant elevations in miR-183 and GNG7 expression in placental tissues of PE patients. FOXP1 was observed to promote proliferation, invasion, and angiogenesis in human chorionic trophoblastic cells. miR-183 resulted in depletion of FOXP1 expression, while FOXP1 was capable of restraining GNG7 expression and promoting the mTOR pathway. The findings confirmed the effects of FOXP1 on PE. In conclusion, miR-183 exhibits an inhibitory role in PE through suppression of FOXP1 and upregulation of GNG7.

Elevated miR-23a impairs trophoblast migration and invasiveness through HDAC2 inhibition and NF-κB activation

Preeclampsia (PE) is a pregnancy-specific disorder characterized by the onset of hypertension and proteinuria with onset after the 20th week of gestation. The pathogenesis of PE is attributed to increased trophoblast cell death and poor trophoblast migration/invasiveness. This study investigates the function of microRNA-23a (miR-23a) in PE and its effects on migration and invasion of trophoblast cells HTR-8/SVneo. We found higher expression of miR-23a in placental tissue samples from PE pregnant women compared to samples from normal pregnant women. Enhancing miR-23a expression by its specific mimic reduced HTR-8/SVneo cell migration and invasion and increased HTR-8/SVneo cell apoptosis. The dual-luciferase reporter gene assay revealed miR-23a binding with HDAC2. We found that HDAC2 was poorly expressed in placental tissue samples from PE pregnant women, and its expression correlated inversely with miR-23a expression. HTR-8/SVneo cells showed diminished HDAC2 expression upon miR-23a elevation and increased HDAC2 expression upon miR-23a inhibition. Lentivirus-mediated HDAC2 knockdown mimicked the effects of miR-23a on HTR-8/SVneo cells and led to NF-κB activation. Similarly, HDAC2 overexpression and NF-κB inhibition both abrogated the effects of miR-23a on HTR-8/SVneo cells, suggesting that miR-23a reduced HTR-8/SVneo cell migration and invasion and increased HTR-8/SVneo cell apoptosis by HDAC2 inhibition and NF-κB activation. In summary, these results support a novel role of miR-23b in invasion and apoptosis of trophoblast cells, and imply that targeting miR-23b may be a new avenue for treating PE.