Downregulations of circulating miR-31 and miR-21 are associated with preeclampsia

Trophoblast microRNAs, pre-eclampsia and intrauterine growth restriction

MicroRNAs (miRNAs) are small single-stranded non-coding RNA molecules that play a role in regulating gene expression in a tissue-specific manner. Placental miRNAs expression pattern dynamically changes during pregnancy influencing cell proliferation, differentiation and apoptosis. Changes of specific miRNA levels have been described in pregnancies complicated by hypertensive disorders or gestational diabetes and a growing interest in understanding miRNA role on placental development and placental disorders is currently going on. The present review evaluates the possible roles of miRNAs in trophoblastic invasion and placental development as well as their potential role as biomarkers for the prediction of placental disorders focusing the attention on intrauterine growth restriction.

Circulating miRNAs and Preeclampsia: From Implantation to Epigenetics

In this review, we comprehensively present the literature on circulating microRNAs (miRNAs) associated with preeclampsia, a pregnancy-specific disease considered the primary reason for maternal and fetal mortality and morbidity. miRNAs are single-stranded non-coding RNAs, 20-24 nt long, which control mRNA expression. Changes in miRNA expression can induce a variation in the relative mRNA level and influence cellular homeostasis, and the strong presence of miRNAs in all body fluids has made them useful biomarkers of several diseases. Preeclampsia is a multifactorial disease, but the etiopathogenesis remains unclear. The functions of trophoblasts, including differentiation, proliferation, migration, invasion and apoptosis, are essential for a successful pregnancy. During the early stages of placental development, trophoblasts are strictly regulated by several molecular pathways; however, an imbalance in these molecular pathways can lead to severe placental lesions and pregnancy complications. We then discuss the role of miRNAs in trophoblast invasion and in the pathogenesis, diagnosis and prediction of preeclampsia. We also discuss the potential role of miRNAs from an epigenetic perspective with possible future therapeutic implications.

Integrated analysis of microRNA and mRNA expression profiles in Preeclampsia

BACKGROUND

Preeclampsia (PE), a pregnancy specific syndrome, is one kind of common gestational hypertension disease, which can cause maternal and perinatal mortality and morbidity. This study was conducted to identify key microRNAs (miRNAs), mRNAs and related signaling pathways in the pathogenesis of PE.

METHODS

Whole transcriptome sequencing and small RNA sequencing of the peripheral blood from 3 PE patients and 3 normal pregnant women were performed. Differential expressed (DE) miRNAs were identified using the DEseq2 package. Target genes of the selected upregulated and downregulated DE miRNAs were predicted. Based on the hypergeometric distribution of DE miRNA target genes, we analyzed GO enrichment and KEGG pathway enrichment using R.

RESULTS

Total 1291 and 1281 novel RNAs were obtained from the preeclampsia patients and healthy individuals. 70 miRNAs were screened out with significant levels with 51 significantly upregulated and 19 significantly downregulated. 44,306 genes were predicted as the targets of these miRNAs. Besides, KEGG pathway analysis revealed that the upregulated miRNAs were enriched in Glycosaminoglycan biosynthesis-chondroitin sulfate / dermatan sulfate, Base excision repair and the downregulated miRNAs were enriched in Tuberculosis, Phagosome.

CONCLUSION

We constructed regulatory networks of miRNAs and target genes, there were 2208 negative miRNA-mRNA interactions in total. The network and pathway information illustrate the potential functions of mRNAs and miRNAs in PE pathogenesis.

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.

The effect of MicroRNAs variants on idiopathic recurrent pregnancy loss

BACKGROUND

Although the importance of miRNA variants in female reproductive disorders has been frequently reported, the association between miRNA polymorphisms and recurrent pregnancy loss (RPL) has been poorly studied. In this study, we aimed to assess the correlation of four different miRNA variants to unexplained RPL.

METHODS AND RESULTS

The prevalence of four SNPs including miR-21 rs1292037, miR-155-5p rs767649, miR-218-2 rs11134527, and miR-605 rs2043556 in 280 cases with iRPL and 280 controls was performed. The DNA was extracted from all subjects and the SNPs were genotyped using RFLP-PCR methods. The data revealed that rs1292037 and rs767649 were significantly associated with higher rates of iRPL in patients compared with controls while rs11134527 and rs2043556 showed no association with increased rates of iRPL among patients. The haplotypes T-A-G-G and T-A-G-A were the most frequent in both cases and controls. Three haplotypes including T-T-G-A, C-T-G-G, and T-A-A-A showed significantly different frequencies in patients in comparison to healthy females.

CONCLUSION

This study suggests that rs1292037 and rs767649 could be risk factors for increased rates of iRPL.

Emerging role of miRNAs, lncRNAs, and circRNAs in pregnancy-associated diseases

ABSTRACT

Accumulating studies have demonstrated that non-coding RNAs (ncRNAs), functioning as important regulators of transcription and translation, are involved in the establishment and maintenance of pregnancy, especially the maternal immune adaptation process. The endometrial stromal cells (ESCs), trophoblast cells, and decidua immune cells that reside at the maternal-fetal interface are thought to play significant roles in normal pregnancy and pregnancy-associated diseases. Here, we reviewed the up-to-date evidence on how microRNA, long non-coding RNA, and circular RNA regulate ESCs, trophoblast cells, and immune cells and discussed the potential applications of these ncRNAs as diagnostic and therapeutic markers in pregnancy complications.

MGST1 alleviates the oxidative stress of trophoblast cells induced by hypoxia/reoxygenation and promotes cell proliferation, migration, and invasion by activating the PI3K/AKT/mTOR pathway

Preeclampsia (PE) is a common pregnancy-specific syndrome with an incidence of 4.6% in all pregnant women. Numerous studies have uncovered the functions and mechanisms of microsomal glutathione transferase 1 (MGST1) in different diseases and cellular processes, but whether MGST1 plays a role in PE remains unclear. Our study aimed to investigate the regulatory role of MGST1 in PE progression. In this study, the HTR8/SVneo cells were incubated with CoCl₂ (250 µM) to mimic hypoxia in trophoblasts. Real-time quantitative polymerase chain reaction revealed that MGST1 was dramatically reduced in the placenta of PE patients. The proliferation of HTR8/SVneo cells was assessed via the Cell Counting Kit-8 and colony formation assays, and the results showed that MGST1 upregulation increased the cell viability of HTR8/SVneo cells. In addition, wound healing and Transwell assays unveiled that the elevation of MGST1 enhanced trophoblast cell migration and invasion. Moreover, the upregulation of MGST1 alleviated the hypoxia-induced oxidative stress in trophoblast cell. Mechanically, we found that MGST1 regulated PE progression by activating the phosphoinositide-3-kinase/protein kinase B/mechanistic target of rapamycin (PI3K/AKT/mTOR) pathway. In conclusion, MGST1 alleviated the oxidative stress of trophoblast cells induced by hypoxia/reoxygenation and promoted cell proliferation, migration, and invasion via the activation of the PI3K/AKT/mTOR pathway in PE. These results suggested that MGST1 can be a potential target for the prevention and treatment of PE.

MiR-326 inhibits trophoblast growth, migration, and invasion by targeting PAX8 via Hippo pathway

Preeclampsia (PE), a pregnancy disorder that affects 5-7% of pregnant women, is among the primary causes for maternal and perinatal mortality. PE is believed to be associated with insufficient invasion of villous and extravillous trophoblasts (EVTs), which hampers uterine spiral artery remodeling and finally induces PE. But the mechanism responsible for reduction of trophoblast invasion remains unclear. In this study, placental tissues taken from healthy donors and PE patients were used to evaluate the miR-326 expression; CCK8 and colony formation assays were used to confirm the effect of miR-326 on cell proliferation; transwell assay was used to demonstrate the effect of miR-326 on cell invasion capability; western blot was used to investigate the underlying mechanism; and luciferase assay was used to detect the effect of miR-326 on YAP/TAZ-mediated transcription activity. It was revealed the miR-326 expression was higher in placentas from PE patients than from healthy donors. After transfection of miR-326 mimics, trophoblast proliferation and invasion were impaired. Using TargetScan, we speculated that PAX8 was a target of miR-326, which was later confirmed by western blot. The YAP/TAZ expression was also downregulated after transfection with miR-326. Luciferase assay demonstrated that overexpression of miR-326 suppressed YAP/TAZ-mediated transcription activity by targeting PAX8. Overexpression of PAX8 could partly rescue miR-326-induced suppression of trophoblast proliferation and invasion. Taken together, our result indicated that miR-326 suppresses trophoblast growth, invasion, and migration by means of targeting PAX8 via the Hippo pathway.

Preeclamptic Women Have Disrupted Placental microRNA Expression at the Time of Preeclampsia Diagnosis: Meta-Analysis

Introduction: Preeclampsia (PE) is a pregnancy-associated, multi-organ, life-threatening disease that appears after the 20th week of gestation. The aim of this study was to perform a systematic review and meta-analysis to determine whether women with PE have disrupted miRNA expression compared to women who do not have PE. Methods: We conducted a systematic review and meta-analysis of studies that reported miRNAs expression levels in placenta or peripheral blood of pregnant women with vs. without PE. Studies published before October 29, 2021 were identified through PubMed, EMBASE and Web of Science. Two reviewers used predefined forms and protocols to evaluate independently the eligibility of studies based on titles and abstracts and to perform full-text screening, data abstraction and quality assessment. Standardized mean difference (SMD) was used as a measure of effect size. Results: 229 publications were included in the systematic review and 53 in the meta-analysis. The expression levels in placenta were significantly higher in women with PE compared to women without PE for miRNA-16 (SMD = 1.51,95%CI = 0.55-2.46), miRNA-20b (SMD = 0.89, 95%CI = 0.33-1.45), miRNA-23a (SMD = 2.02, 95%CI = 1.25-2.78), miRNA-29b (SMD = 1.37, 95%CI = 0.36-2.37), miRNA-155 (SMD = 2.99, 95%CI = 0.83-5.14) and miRNA-210 (SMD = 1.63, 95%CI = 0.69-2.58), and significantly lower for miRNA-376c (SMD = -4.86, 95%CI = -9.51 to -0.20). An increased level of miRNK-155 expression was found in peripheral blood of women with PE (SMD = 2.06, 95%CI = 0.35-3.76), while the expression level of miRNA-16 was significantly lower in peripheral blood of PE women (SMD = -0.47, 95%CI = -0.91 to -0.03). The functional roles of the presented miRNAs include control of trophoblast proliferation, migration, invasion, apoptosis, differentiation, cellular metabolism and angiogenesis. Conclusion: miRNAs play an important role in the pathophysiology of PE. The identification of differentially expressed miRNAs in maternal blood creates an opportunity to define an easily accessible biomarker of PE.

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.

The MEG3 lncRNA promotes trophoblastic cell growth and invasiveness in preeclampsia by acting as a sponge for miR-21, which regulates BMPR2 levels

Preeclampsia (PE) is one of the leading causes of maternal morbidity and mortality in pregnant women. This study aimed to investigate the potential impact and regulatory mechanisms of bone morphogenetic protein receptor 2 (BMPR2) on the progression of PE. We obtained placental tissues from pregnant women with PE and normal pregnant women, and the results showed that BMPR2 was expressed at low levels in the tissue from PE women. Genetic knockdown of BMPR2 increased the proliferation and invasion of cultured trophoblast cells, whereas its overexpression reduced these characteristics. Bioinformatics analysis and luciferase reporter gene assays confirmed that BMPR2 is a direct target of miR-21. Overexpression of a miR-21 inhibitor promoted the growth and invasiveness of trophoblast cells, whereas the opposite results were observed for the miR-21 mimic. Furthermore, miR-21 was sponged by the lncRNA MEG3, and shRNA inhibition of MEG3 reduced trophoblast cell growth and invasiveness. miR-21 was upregulated in the tissues from PE women, whereas MEG3 was downregulated, and the two were negatively correlated. Collectively, this study demonstrates that the lncRNA MEG3 acts as a sponge for miR-21, which regulates BMPR2 expression and promotes trophoblast cell proliferation and invasiveness, thereby preventing the development of PE. These findings provide novel insight into a targeted therapy that could be used to treat or prevent the development of PE.

The Value of Circulating microRNAs for Diagnosis and Prediction of Preeclampsia: a Meta-analysis and Systematic Review

Preeclampsia (PE) is one of the main causes of maternal death worldwide, but our understanding of the molecular characteristics of disease progression is limited. In this meta-analysis, we aimed to assess the value of peripheral blood microRNAs (miRNAs) as diagnostic and predictive markers of PE. We screened PubMed, Web of Science, and Embase databases; searched articles about "miRNAs and PE" up to November 30, 2020; and conducted biological information and subgroup analysis. We used QUADAS-2 (quality assessment of diagnostic accuracy studies-2) to evaluate the included articles by two independent reviewers, calculated the combined diagnostic and predictive indicators using the random effects model, explored the sources of potential heterogeneity through subgroup analysis, and evaluated publication bias using Deeks' funnel plot asymmetry test using Stata 14.0 and Review Manager 5.3 software. Forty-three miRNAs from 15 studies, including 2042 healthy controls and 2685 PE patients, had a pooled sensitivity of 0.86 (95% CI: 0.81-0.90), specificity of 0.89 (95% CI: 0.85-0.92), and an AUC of 0.94 (95% CI: 0.91-0.96). Moreover, before 20 weeks of gestation, the combined sensitivity was 0.86 (95% CI: 0.75-0.92), and the specificity was 0.90 (95% CI: 0.83-0.95), which indicated that some of the circulating miRNAs had changed significantly before the clinical symptoms appeared in PE patients. Circulating miRNAs have high diagnostic and predictive accuracy and may be used as non-invasive biomarkers for the diagnosis and prediction of PE. However, a large sample prospective study is still needed.

Bone Marrow Mesenchymal Stem Cells (BMSCs)-Derived miR-31 in the Pathogenesis of Recurrent Abortion by Regulating Kisspeptins 1 (KISS1) Expression

Bone marrow mesenchymal stem cells (BMSCs) are potentially efficacious in treating recurrent pregnancy disorders and endometrial injury. Uterine parenchymal cells interact with BMSCs to promote functional recovery. Our research aimed to explore the effect of BMSCs-derived miR-31 on recurrent pregnancy loss. A recurrent pregnancy loss mouse model was constructed followed by nanoparticle analysis of BMSC and miR-31 expressing by RT-PCR. The levels of miR-31 in BMSCs (miR-31+BMSCs or BMSCs) and their counterpart exosomes were up- or down-regulated to explore the effects of aberrant expression of miR-31 on endometrial damage in recurrent pregnancy loss. The analysis of BMSC nanoparticles showed that miR-31 was derived from BMSC. We found increased levels of miR-31 in miR-340 + BMSCs after incubation with endometrial stromal cells (ESCs) compared to controls. Labeling of exosomes by red fluorescent protein indicated that exosomes were liberated out of BMSCs and translocated into neighboring ESCs, and mice treated with miR-340 + BMSCs had improved functional recovery from recurrent pregnancy loss. BMSC-derived miR-31 mediates functional recovery induced in recurrent pregnancy miscarriage mice by regulating KISS1 expression and fibrosis gene expression.

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.

Association of Circulating miRNA Expression with Preeclampsia, Its Onset, and Severity

MicroRNAs (miRNAs) are one of the important regulators of cellular functions fundamental for healthy pregnancy processes, including angiogenesis and differentiation of trophoblast cells, and their deregulation could be implicated in the pathogenesis of pregnancy complications, including preeclampsia (PE). The aim of this study was to assess the association of miRNA expression in plasma samples with PE, its onset, and severity. Our study enrolled 59 pregnant women, 27 in the preeclamptic study group and 32 in the control group with physiological pregnancy. Preeclamptic pregnancies were divided into subgroups based on the severity and onset of disease. Relative expression of miR-21-5p, miR-155-5p, miR-210-5p, miR-16-5p, and miR-650 isolated from plasma samples was analysed by quantitative real-time PCR and normalised to experimentally established reference genes. Our results revealed upregulation of miR-21-5p (1.16-fold change, p = 0.0015), miR-155-5p (1.62-fold change, p = 0.0005) in preeclamptic pregnancies, compared to controls. Overexpression of these two miRNAs was observed, especially in subgroups of severe and late-onset PE compared to healthy pregnancies. Although we hypothesised that the expression level of studied miRNAs could vary between PE subtypes (mild vs. severe, early onset vs. late-onset), no obvious differences were detected. In conclusion, our study could contribute to the large-scale studies for the identification of non-invasive biomarkers for PE detection to improve outcomes for women and their new-borns.

MiR-141-3p downregulation promotes tube formation, migration, invasion and inhibits apoptosis in hypoxia-induced human umbilical vein endothelial cells by targeting Notch2

Vascular endothelial cell damage is regarded as the carrier in the progression of the pathological changes of preeclampsia (PE) from the placenta to maternal organs. MicroRNA (miR)-141-3p was aberrantly expressed during PE pathogenesis. We investigated the role of miR-141-3p in regulating the biological behaviors of endothelial cells in PE. Human umbilical vein endothelial cells (HUVECs) were isolated from the human umbilical cords and cultured under hypoxia condition to establish PE models. The binding of miR-141-3p and Notch2 was confirmed by dual-luciferase reporter assay. HUVECs were transfected with miR-141-3p inhibitor and siRNA-Notch2. The viability, vascularization capability, migration, and invasion of HUVECs were evaluated by MTT, tube formation, and Transwell assays. Cell apoptosis was measured via flow cytometry. The expressions of miR-141-3p, Notch2, Bcl-2, Bax and cleaved caspase-3 were assessed by qRT-PCR or Western blot. MiR-141-3p expression was upregulated in the HUVECs isolated from PE tissues and hypoxia-induced HUVECs. Hypoxia treatment inhibited viability, tube formation, migration, and invasion, and promoted apoptosis in HUVECS, as well as increased Bax and cleaved caspase-3 expressions and decreased Bcl-2 expression. Downregulating miR-141-3p expression promoted viability, tube formation, migration and invasion, and inhibited apoptosis in HUVECs, counteracting the effect of hypoxia on HUVECs. MiR-141-3p directly targeted Notch2. Silencing Notch2 reversed the promoting effect of downregulated miR-141-3p expression on HUVECs. In conclusion, downregulating miR-141-3p expression during hypoxia promotes tube formation, migration, and invasion and inhibits apoptosis in HUVECs by targeting Notch2.

lncRNA SNHG14 involved in trophoblast cell proliferation, migration, invasion and epithelial-mesenchymal transition by targeting miR-330-5p in preeclampsia

Preeclampsia (PE), a pregnancy-specific disease, has become one of the leading causes of maternal and neonatal morbidity and mortality. Pathogenesis of PE has still not been fully addressed and there is a great need to develop early diagnosis markers and effective therapy. This study aimed to determine if lncRNA SNHG14 has a protective effect on placental trophoblast and prevents PE. SNHG14 levels in the peripheral blood from patients with PE or from women with healthy pregnancies were detected using RT-qPCR. The relationship between SNHG14 and miR-330-5p was determined using a dual-luciferase reporter assay. In addition, cell proliferation and cell cycle were evaluated by performing CCK8 assays and flow-cytometric analysis, respectively. Wound-healing and transwell assays were performed to assess cell migration and invasion ability. lncRNA SNHG14 was downregulated in PE patients; it was involved in trophoblast proliferation and regulated cell proliferation during G1/S transition. In addition, lncRNA SNHG14 promoted migration, invasion and epithelial-mesenchymal transition (EMT) in HTR-8/SVneo cells. Luciferase reporter assay indicated that lncRNA SNHG14 served as a molecular sponge for miR-330-5p and negatively regulated miR-330-5p expression in PE. Furthermore, the effects of silenced SNHG14 on trophoblast proliferation, migration, invasion and EMT were reversed by addition of miR-330-5p inhibitor, suggesting that in PE lncRNA SNHG14 functions by competitively binding to miR-330-5p. Taken together, the current study demonstrated that in PE lncRNA SNHG14 is a vital regulator by binding to miR-330-5p. SNHG14 might serve as a therapeutic application in PE progression.

MiR-21-5p directly contributes to regulating eNOS expression in human artery endothelial cells under normoxia and hypoxia

Clinical conditions associated with hypoxia and oxidative stress, such as fetal growth restriction (FGR), results in endothelial dysfunction. Previous reports show that changes in eNOS expression under these conditions are tightly controlled by DNA methylation and histone posttranslational modifications. However, the contribution of an orchestrating epigenetic mechanism, such as miRNAs, on the NO-related genes expression has not been addressed. We aimed to determine the levels of miRNAs highly expressed in normal endothelial cells (EC), miR-21 and miR-126, in FGR human umbilical artery EC (HUAEC), and their effects on hypoxia-dependent regulation of both, NO-related and oxidative stress-related genes. Results were validated by transcriptome analysis of HUAEC cultured under chronic low oxygen conditions. Cultured FGR-HUAEC showed decreased hsa-miR-21, DDAH1, SOD1, and NRF2, but increased miR-126, NOX4, and eNOS levels, compared with controls. MiR-21-5p levels in FGR were associated with increased hg-miR-21 gene promoter methylation, with no changes in hg-miR-126 gene promoter methylation. HUAEC exposed to hypoxia showed a transient increase in eNOS and DDAH11, paralleled by decrease miR-21-5p levels, but no changes in miR-126-3p and the other genes under study. Transcriptome profiling showed an inverse relationship among miR-21 and several transcripts targeted by miR-21 in HUAEC exposed to hypoxia, meanwhile miR-21-5p-mimic decreased eNOS and DDAH1 transcripts stability, blocking their induction by hypoxia. Consequently, FGR programs a hypoxia-related miRNA that contributes to the regulation of the NO pathway, involving a direct effect of miR-21-5p on eNOS transcript stability, not previously reported. Moreover, hypoxia downregulates miR-21-5p, contributing to increasing the expression of NO-related genes in arterial endothelial cells.

Circulating microRNAs as biomarkers for diagnosis and prediction of preeclampsia: A systematic review and meta-analysis

OBJECTIVE

We carried out a meta-analysis to quantitatively summarize the overall diagnostic and predictive effects of circulating microRNAs in diagnosis and prediction of preeclampsia, respectively.

STUDY DESIGN

We screened selected databases and systematically retrieved articles until September 20th, 2019 for analysis. After literature screening and data extraction, we firstly conducted quality assessment according to QUADAS-2 score system. And then the pooled diagnostic and predictive parameters were calculated using a bivariate random-effect meta-analysis model. We used threshold effect analysis and subgroup analysis to identify the sources of heterogeneity. The clinical utility was validated through the Fagan's Nomogram. Sensitivity analysis was performed to assess the reliability of each included study, and we evaluated publication bias with the Deeks' funnel plot asymmetry test.

RESULTS

The meta-analysis included 8 articles comprising 273 preeclampsia patients and 343 normal pregnancies. Pooled results of diagnostic values of 5 articles indicated a sensitivity of 0.88 (95 %CI: 0.80-0.93), specificity of 0.87 (95 %CI: 0.78-0.92) and diagnostic odds ratio of 50.24 (95 %CI: 21.28-118.62). The pooled sensitivity, specificity, DOR of circulating microRNAs for predicting preeclampsia of asymptomatic pregnancies were 0.61 (95 %CI: 0.55-0.68), 0.78 (95 %CI: 0.72-0.83) and 5.7 (95 %CI: 3.7-8.7) across other 3 articles. Subgroup analysis revealed that non-plasma specimen type, non-U6 reference gene and non-Asian had better diagnostic value while due to limited data, we did not conduct a subgroup analysis of predictive value.

CONCLUSIONS

Circulating miRNAs distinguish patients with preeclampsia from controls with relatively high diagnostic and predictive accuracy. Then we conclude that circulating miRNAs could be a useful screening tool to diagnose and predict preeclampsia. However, its utility should be judged with caution and large-sample prospective studies are warranted to explore if its implementation improves maternal and neonatal outcomes.

Identifying key genes and drug screening for preeclampsia based on gene expression profiles

Preeclampsia (PE) is characterized by gestational hypertension and proteinuria, and is a leading cause of maternal death and perinatal morbidity globally. Although the exact cause of PE remains unclear, several studies have suggested a role for abnormal expression of multiple genes. The aim of the present study was to identify key genes and related pathways, and to screen for drugs that regulate these genes for potential PE therapy. The GSE60438 dataset was acquired from the Gene Expression Omnibus database to analyze differentially expressed genes (DEGs). By constructing a protein-protein interaction network and performing reverse transcription-quantitative PCR verification, proteasome 26S subunit, non-ATPase 14, prostaglandin E synthase 3 and ubiquinol-cytochrome c reductase core protein 2 were identified as key genes in PE. In addition, PE was found to be associated with ‘circadian rhythm’, ‘fatty acid metabolism’, ‘DNA damage response detection of DNA damage’, ‘regulation of DNA repair’ and ‘endothelial cell development’. Through connectivity map analysis of DEGs, furosemide and droperidol were suggested to be therapeutic drugs that may target the hub genes for PE treatment. Results analysis of GSEA were included in the discussion section of this article. In conclusion, the current study identified novel key genes associated with the onset of PE and potential drugs for PE treatment.