First trimester PBMC microRNA predicts adverse pregnancy outcome

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.

Role of microRNAs regulating trophoblast cell function in the pathogenesis of pre‑eclampsia (Review)

Pre-eclampsia (PE) is a complicated pregnancy-specific disease and is considered the primary reason for maternal and foetal mortality and morbidity. PE has a multifactorial pathogenesis but the causes of PE remain unclear. The functions of trophoblasts, including differentiation, proliferation, migration, invasion and apoptosis, are essential for successful pregnancy. During the early stages of placental development, trophoblasts are strictly regulated by several molecular pathways; however, an imbalance of these molecular pathways can lead to severe placental lesions and pregnancy complications. Certain microRNAs (miRs) are abnormally expressed in PE, with several miRs involved in the regulation of pregnancy-associated genes. The present review discusses the miRs regulating trophoblast function, how they affect the pathogenesis of PE and evaluating the possibility of miRs in screening, diagnosis and treatment of PE.

Expression pattern and clinical significance of microRNA-let-7a and IFN-gamma in placental tissue of patients with preeclampsia with severe features

OBJECTIVES

Preeclampsia with severe features (PECsf) is a common disease in pregnant women. let-7a and IFN-gamma (interferon-gamma) are involved in diagnosis and prognosis of preeclampsia. This study explored effects of let-7a and IFN-gamma on PECsf patients.

METHODS

The placental tissue of 21 PECsf, 19 preeclampsia without severe features (PEC), and 20 normal pregnant women were collected, and clinical data were recorded. let-7a and IFN-gamma expressions in placental tissue were detected. The correlation between let-7a/IFN-gamma expression and clinical indexes was analyzed. According to let-7a and IFN-gamma expressions, PECsf patients were assigned into Hlet-7a group (let-7a high expression group), Llet-7a group (let-7a low expression group), HIFN-gamma group (IFN-gamma high expression group) and LIFN-gamma group (IFN-gamma low expression group). The incidence of adverse prognosis was compared.

RESULTS

let-7a and IFN-gamma were highly expressed in placental tissue of preeclampsia patients, with significant differences between PEC and PECsf. The high expressions of let-7a and IFN-gamma were positively correlated with mean arterial pressure, lactate dehydrogenase, and 24 h urinary protein in placental tissues of PECsf patients. High let-7a and IFN-gamma expressions were correlated with adverse outcomes of PECsf.

CONCLUSIONS

High let-7a and IFN-gamma expressions were correlated with clinical features, and could be used as biomarkers for treatment and poor prognosis of PECsf.

PBMCs: a new source of diagnostic and prognostic biomarkers

There are various types of molecular biomarkers that are derived from distinct starting materials. Although many indirect biomarkers are found in blood, their detection remains a challenging issue because of the high degree of fragmentation, minute quantity and a vast amount of non-specific background. The present review points out the sensitivity and specificity of peripheral blood mononuclear cells (PBMCs) as an intact source of biomarkers in a variety of diseases. Multiple recent studies that have used PBMCs as a source of biomarkers reveal the alteration of mRNAs/microRNAs (miRNAs) signature and methylation profile in many kinds of disorders; for instance, dysregulation of mRNAs/miRNAs in schizophrenia, diabetes and different types of cancers and change in the methylation status of LINE-1 in neoplasms. In conclusion with a strong probability, PBMCs mimic conditions of some tissues which are in contact with them like the tumour cells, hence providing a non-invasive and suitable source of biomarkers.

Cardiovascular Disease-Associated MicroRNA Dysregulation during the First Trimester of Gestation in Women with Chronic Hypertension and Normotensive Women Subsequently Developing Gestational Hypertension or Preeclampsia with or without Fetal Growth Restriction

The aim of the study was to assess if cardiovascular disease-associated microRNAs would be able to predict during the early stages of gestation (within 10 to 13 weeks) subsequent onset of hypertensive pregnancy-related complications: gestational hypertension (GH) or preeclampsia (PE). Secondly, the goal of the study was to assess if cardiovascular disease-associated microRNAs would be able to detect the presence of chronic hypertension in early pregnancies. The retrospective study was performed on whole peripheral blood samples collected from singleton Caucasian pregnancies within the period November 2012 to March 2020. The case control study, nested in a cohort, involved all women with chronic hypertension (n = 29), all normotensive women that later developed GH (n = 83) or PE with or without fetal growth restriction (FGR) (n = 66), and 80 controls selected on the base of equal sample storage time. Whole peripheral blood profiling was performed with the selection of 29 cardiovascular disease-associated microRNAs using real-time RT-PCR. Upregulation of miR-1-3p (51.72% at 10.0% FPR) was observed in patients with chronic hypertension only. Upregulation of miR-20a-5p (44.83% and 33.33% at 10.0% FPR) and miR-146a-5p (65.52% and 42.42% at 10.0% FPR) was observed in patients with chronic hypertension and normotensive women with later occurrence of PE. Upregulation of miR-181a-5p was detected in normotensive women subsequently developing GH (22.89% at 10.0% FPR) or PE (40.91% at 10.0% FPR). In a part of women with subsequent onset of PE, upregulation of miR-143-3p (24.24% at 10.0% FPR), miR-145-5p (21.21% at 10.0% FPR), and miR-574-3p (27.27% at 10.0% FPR) was also present. The combination of microRNA biomarkers (miR-20a-5p, miR-143-3p, miR-145-5p, miR-146a-5p, miR-181a-5p, and miR-574-3p) can predict the later occurrence of PE in 48.48% of pregnancies at 10.0% FPR in early stages of gestation. The combination of upregulated microRNA biomarkers (miR-1-3p, miR-20a-5p, and miR-146a-5p) is able to identify 72.41% of pregnancies with chronic hypertension at 10.0% FPR in early stages of gestation. Cardiovascular disease-associated microRNAs represent promising biomarkers with very good diagnostical potential to be implemented into the current first trimester screening program to predict later occurrence of PE with or without FGR. The comparison of the predictive results of the routine first trimester screening for PE and/or FGR based on the criteria of the Fetal Medicine Foundation and the first trimester screening for PE wo/w FGR using a panel of six cardiovascular disease-associated microRNAs only revealed that the detection rate of PE increased 1.45-fold (48.48% vs. 33.33%).

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.

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.

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.

MicroRNAs isolated from peripheral blood in the first trimester predict spontaneous preterm birth

OBJECTIVE

To predict spontaneous preterm birth among pregnant women in an African American population using first trimester peripheral blood maternal immune cell microRNA.

STUDY DESIGN

This was a retrospective nested case-control study in pregnant patients enrolled between March 2006 and October 2016. For initial study inclusion, samples were selected that met the following criteria: 1) singleton pregnancy; 2) maternal body mass index (BMI) <30 kg/m2; 3) blood sample drawn between 6 weeks to 12 weeks 6 days gestation; 4) live born neonate with no detectable birth defects. Using these entry criteria, 486 samples were selected for study inclusion. After sample quality was confirmed, 139 term deliveries (38-42 weeks) and 18 spontaneous preterm deliveries (<35 weeks) were selected for analysis. Samples were divided into training and validation sets. Real time reverse transcription quantitative polymerase chain reaction (rt-qPCR) was performed on each sample for 45 microRNAs. MicroRNA Risk Scores were calculated on the training set and area-under-the-curve receiver-operating-characteristic (AUC-ROC) curves were derived from the validation set.

RESULTS

The AUC-ROC for the validation set delivering preterm was 0.80 (95% CI: 0.69 to 0.88; p = 0.0001), sensitivity 0.89, specificity of 0.71 and a mean gestational age of 10.0 ±1.8 weeks (range: 6.6-12.9 weeks). When the validation population was divided by gestational age at the time of venipuncture into early first trimester (mean 8.4 ±1.0 weeks; range 6.6-9.7 weeks) and late first trimester (mean 11.5±0.8 weeks; range 10.0-12.9 weeks), the AUC-ROC scores for early and late first trimester were 0.79 (95% CI: 0.63 to 0.91) and 0.81 (95% CI: 0.66 to 0.92), respectively.

CONCLUSION

Quantification of first trimester peripheral blood MicroRNA identifies risk of spontaneous preterm birth in samples obtained early and late first trimester of pregnancy in an African American population.

miR-10a in Peripheral Blood Mononuclear Cells Is a Biomarker for Sepsis and Has Anti-Inflammatory Function

Background

Recent literature has reported the use of circulating microRNAs (miRNAs) as biomarkers for sepsis. Immune cells play an essential role in the pathophysiology of sepsis. The aim of this prospective study was to identify miRNAs in peripheral blood mononuclear cells (PBMC) that could differentiate between sepsis and infection based on Sepsis-3 definition.

Methods

A total of 62 patients (41 with sepsis and 21 with infection suffering from pneumonia but without sepsis) and 20 healthy controls were enrolled into the study. PBMC at admission were examined for a panel of 4 miRNAs (miR-10a, miR-17, miR-27a, and miR-125b), which have been documented to participate in inflammatory response in immune cells, via qRT-PCR. Data were validated in a mouse model of sepsis induced via cecal ligation and puncture (CLP) and THP-1 monocytes.

Results

miR-10a levels in PBMC at admission were significantly lower in sepsis patients compared with patients with infection and healthy controls. miR-10a levels were negatively correlated with disease severity scores as well as levels for c-reactive protein and procalcitonin. In addition, low miR-10a expression had a diagnostic value for sepsis and a prognostic value for 28-day mortality in receiving operating characteristic analysis. Compared with infection patients and healthy controls, PBMC from sepsis patients also had higher levels of mitogen-activated kinase kinase kinase 7 (MAP3K7), a known target protein of miR-10a and an activator of the NF-κB pathway. In the mouse model of CLP-induced sepsis, miR-10a levels in PBMC were significantly decreased as early as 8 h after CLP. Overexpression of miR-10a in THP-1 cells significantly reduced the expression of MAP3K7 and proinflammatory cytokines including IL-6, TNF-α, and MCP-1.

Conclusions

PBMC miR-10a levels are decreased in sepsis and negatively correlated with the disease severity. Levels of miR-10a could distinguish between sepsis and infection and predict 28-day mortality. miR-10a plays an anti-inflammatory role in the pathogenesis of sepsis.

Expression profile of Let-7s in peripheral blood mononuclear cells of normal and severe preeclampsia pregnant women

HEADINGS AIM

We aimed to investigate if the let-7 s expression level in the serum of peripheral blood from pregnant women with severe pre-eclampsia and normal pregnant women is related to the incidence of severe pre-eclampsia.

METHODS

Total RNA was extracted from collected peripheral blood mononuclear cells from 20 or over weeks pregnant women diagnosed with severe pre-eclampsia (age: 31.57 ± 4.94) and normal pregnant women (age: 29.75 ± 4.6) respectively, followed by real-time PCR to examine the expression of let-7 s. Correlation between let-7 s expression level and maternal age or body mass index of the normal pregnant women were also analyzed using SPSS21.0 software.

RESULTS

Let-7a and let-7 g were significantly increased in pregnant women with severe pre-eclampsia by 4.67 fold and 2.37 fold respectively compared to the normal pregnant women, whereas there was no significant difference in let-7b and let-7i. Moreover, there was no correlation between maternal age or body mass index and the expression level of let-7a, let-7b, let-7 g, and let-7i.

CONCLUSIONS

In conclusion, let-7a and let-7 g were significantly increased in the PBMCs of severe pre-eclampsia women compared to normal controls. Moreover, their expression level was not correlated to the maternal age or body mass of patients. Our data indicated that let-7a and let-7 g may be considered as predictive markers for SPE.

Roles of microRNAs in preeclampsia

Preeclampsia (PE) is a complex disorder that is characterized by hypertension and proteinuria after the 20th week of pregnancy, and it causes most neonatal morbidity and perinatal mortality. Most studies suggest that placental dysfunction is the main cause of PE. However, genetic factors, immune factors, and systemic inflammation are also related to the pathophysiology of this syndrome. Thus far, the exact pathogenesis of PE is not yet fully understood, and intense research efforts are focused on PE to elucidate the pathophysiological mechanisms. MicroRNAs (miRNAs) refer to small single-stranded and noncoding molecules that can negatively regulate gene expression, and miRNA regulatory networks play an important role in diverse pathological processes. Many studies have confirmed deregulated miRNA in pregnant patients with PE, and the function and mechanism of these differentially expressed miRNA are gradually being revealed. In this review, we summarize the current research about miRNA involved in PE, including placenta-specific miRNA, their predictive value, and their function in the development of PE. This review will provide fundamental evidence of miRNA in PE, and further studies are necessary to explore the roles of miRNA in the early diagnosis and treatment of PE.

Peripheral blood cell microRNA quantification during the first trimester predicts preeclampsia: Proof of concept

Objective

We investigated the capacity of microRNAs isolated from peripheral blood buffy coat collected late during the first trimester to predict preeclampsia.

Study design

The cohort study comprised 48 pregnant women with the following pregnancy outcomes: 8 preeclampsia and 40 with normal delivery outcomes. Quantitative rtPCR was performed on a panel of 30 microRNAs from buffy coat samples drawn at a mean of 12.7±0.5 weeks gestation. MicroRNA Risk Scores were calculated and AUC-ROC calculations derived.

Results

The AUC-ROC for preeclampsia risk was 0.91 (p<0.0001). When women with normal delivery and high-risk background (those with SLE/APS, chronic hypertension and/or Type 2 Diabetes) were compared to women who developed preeclampsia but with a normal risk background (without these mentioned risk factors), preeclampsia was still predicted with an AUC-ROC of 0.92 (p<0.0001).

Conclusion

MicroRNA quantification of peripheral immune cell microRNA provides sensitive and specific prediction of preeclampsia in the first trimester of pregnant women. With this study, we extend the range during which disorders of the placental bed may be predicted from early to the end of the first trimester. This study confirms that buffy coat may be used as a sample preparation.

Early first trimester peripheral blood cell microRNA predicts risk of preterm delivery in pregnant women: Proof of concept

Objective

We investigated the capacity of first trimester peripheral blood mononuclear cell (PBMC) microRNA to determine risk of spontaneous preterm birth among pregnant women.

Study design

The study included 39 pregnant women with the following delivery outcomes: 25 with a full term delivery (38–42 weeks gestation) 14 with spontaneous preterm birth (<38 weeks gestation). Of the 14 women experiencing spontaneous preterm birth, 7 delivered at 34-<38 weeks gestation (late preterm) and 7 delivered at <34 weeks gestation (early preterm). Samples were collected at a mean of 7.9±3.0 weeks gestation. Quantitative rtPCR was performed on 30 selected microRNAs. MicroRNA Risk Scores were calculated and Area-Under the Curve-Receiver-Operational-Characteristic (AUC-ROC) curves derived.

Results

The AUC-ROC for the group delivering preterm (<38 weeks) was 0.95 (p>0.0001). The AUC-ROC for early preterm group (<34 weeks) was 0.98 (p<0.0001) and the AUC-ROC for the late preterm group (34-<38 weeks) was 0.92 (p<0.0001).

Conclusion

Quantification of first trimester peripheral blood PBMC MicroRNA may provide sensitive and specific prediction of spontaneous preterm birth in pregnant women. Larger studies are needed for confirmation.

First trimester screening of circulating C19MC microRNAs and the evaluation of their potential to predict the onset of preeclampsia and IUGR

Objectives

A nested case control study of a longitudinal cohort comparing pregnant women enrolled at 10 to 13 gestational weeks was carried out to evaluate risk assessment for preeclampsia and IUGR based on circulating placental specific C19MC microRNAs in early pregnancy.

Methods

The expression of placental specific C19MC microRNAs (miR-516b-5p, miR-517-5p, miR-518b, miR-520a-5p, miR-520h, and miR-525-5p) was determined in plasma samples from pregnancies that subsequently developed preeclampsia (n = 21), IUGR (n = 18), and 58 normal pregnancies using real-time PCR and comparative Ct method relative to synthetic Caenorhabditis elegans microRNA (cel-miR-39).

Results

Circulating C19MC microRNAs were up-regulated (miR-517-5p, p = 0.005; miR-518b, p = 0.013; miR-520h, p = 0.021) or showed a trend toward up-regulation in patients destined to develop preeclampsia (miR-520a-5p, p = 0.067; miR-525-5p, p = 0.073). MiR-517-5p had the best predictive performance for preeclampsia with a sensitivity of 42.9%, a specificity of 86.2%, a PPV of 52.9% and a NPV of 80.6%. The combination of all examined circulating C19MC microRNAs had no advantage over using only the miR-517-5p biomarker to predict the occurrence of preeclampsia (a sensitivity of 20.6%, a specificity of 90.8%, a PPV of 44.8%, and a NPV of 76.0%).

Conclusions

Up-regulation of miR-517-5p, miR-518b and miR-520h was associated with a risk of later development of preeclampsia. First trimester screening of extracellular miR-517-5p identified a proportion of women with subsequent preeclampsia. No circulating C19MC microRNA biomarkers were identified that could predict later occurrence of IUGR.

Systematic Review of Micro-RNA Expression in Pre-Eclampsia Identifies a Number of Common Pathways Associated with the Disease

Background

Pre-eclampsia (PE) is a complex, multi-systemic condition of pregnancy which greatly impacts maternal and perinatal morbidity and mortality. MicroRNAs (miRs) are differentially expressed in PE and may be important in helping to understand the condition and its pathogenesis.

Methods

Case-control studies investigating expression of miRs in PE were collected through a systematic literature search. Data was extracted and compared from 58 studies to identify the most promising miRs associated with PE pathogenesis and identify areas of methodology which could account for often conflicting results.

Results

Some of the most frequently differentially expressed miRs in PE include miR-210, miR-223 and miR-126/126* which associate strongly with the etiological domains of hypoxia, immunology and angiogenesis. Members of the miR-515 family belonging to the imprinted chromosome 19 miR cluster with putative roles in trophoblast invasion were also found to be differentially expressed. Certain miRs appear to associate with more severe forms of PE such as miR-210 and the immune-related miR-181a and miR-15 families. Patterns of miR expression may help pinpoint key pathways (e.g. IL-6/miR-223/STAT3) and aid in untangling the heterogeneous nature of PE. The detectable presence of many PE-associated miRs in antenatal circulatory samples suggests their usefulness as predictive biomarkers. Further progress in ascertaining the clinical value of miRs and in understanding how they might contribute to pathogenesis is predicated upon resolving current methodological challenges in studies. These include differences in diagnostic criteria, cohort characteristics, sampling technique, RNA isolation and platform-dependent variation in miR profiling.

Conclusion

Reviewing studies of PE-associated miRs has revealed their potential as informants of underlying target genes and pathways relating to PE pathogenesis. However, the incongruity in results across current studies hampers their capacity to be useful biomarkers of the condition.

Deep-sequencing identification of differentially expressed miRNAs in decidua and villus of recurrent miscarriage patients

PURPOSE

MicroRNAs (miRNAs) are small non-coding RNA molecules that play critical roles in post-transcriptional gene expression regulation. The aim of this study was to identify differentially expressed miRNAs in decidua and villus of recurrent miscarriage (RM) patients.

METHODS

Participants were recruited at the outpatient Department of Gynecology and Obstetrics, The Second Hospital of Tianjin Medical University, China. Decidua and villus tissues were collected by curettage from recruited RM patients and normal pregnant women with their informed consent. MiRNAs expression profiles in decidua or villus were respectively determined by the deep-sequencing analysis. The predicated target genes of these differentially expressed miRNAs were analyzed by miRWalk. The differential expressions of four miRNAs in decidua and four miRNAs in villus between the six pairs of RM patients and normal pregnant women were confirmed by qRT-PCR analysis. The expression patterns of two predicated target genes, Bcl-2 and Pten, in the same six pairs of decidual or villus tissues were detected by Western blotting analysis, respectively.

RESULTS

Totally 18 RM patients and 15 normal pregnant women were recruited. Thirty-two miRNAs in decidua and four miRNAs in villus of RM patients were screened out to be significantly up-regulated compared to that of normal pregnant women, and five miRNAs in villus of RM patients were screened out to be remarkably down-regulated compared to that of normal pregnant women (P value < 0.05 and Fold change >2). These differentially expressed miRNAs were predicted to target a large number of genes that involved in cell apoptosis, p53 signaling pathway, cell cycle and other cellular bio-functions. Differential expressions of hsa-miR-516a-5p, -517a-3p, -519a-3p and -519d in decidua, as well as hsa-miR-1, -372, -100-5p and -146a-5p in villus, were validated by qRT-PCR analysis. In the decidual of RM patients, expression of hsa-miR-516a-5p, -517a-3p, -519a-3p and -519d were significantly up-regulated compared to normal pregnancy. In the villi of RM patients, expression of hsa-miR-100 and -146a-5p were significantly higher, while hsa-miR-1 and -372 were significantly lower compared to normal pregnancy. Furthermore, the expression of Bcl-2 and Pten, a predicated target gene of hsa-miR-1 or hsa-miR-372 respectively, was significantly up-regulated in the villi of RM patients.

CONCLUSIONS

These data suggested that the pathogenic process of RM might be associated with the alteration of miRNAs expression profiles in decidua and villus. Especially, the aberrant placental expression of hsa-miR-1 and -372 might be involved in the progression of RM, but need to be further investigated by larger studies in the future.

Aberrant Placental Villus Expression of miR-486-3p and miR-3074-5p in Recurrent Miscarriage Patients and Uterine Expression of These MicroRNAs during Early Pregnancy in Mice

MicroRNAs (miRNAs) are critical regulators of gene expression; they have emerged as new players in the pathophysiology of reproductive disorders such as preeclampsia and recurrent miscarriage (RM). In this study, miRNA expression profiles were determined by deep sequencing analysis in placental villi obtained from women with RM and with gestational age-matched normal pregnancy (NP). A total of 69 miRNAs were found to be aberrantly expressed in RM. Five of these human (Homo sapiens) miRNAs (hsa-miRNAs), including hsa-miR-3074-5p, -486-3p, -1269b, -6765-3p and -144-3p, were validated by qRT-PCR in 12 RM and 10 NP placental villi. Hsa-miR-3074-5p expression was significantly higher, while hsa-miR-486-3p expression was significantly lower, in RM compared to NP. Subsequently, the expression of mouse (Mus musculus) miR-486-3p (mmu-miR-486-3p) and mmu-miR-3074-5p, which are identical to hsa-miR-486-3p and hsa-miR-3074-5p, respectively, were examined by qRT-PCR in the uterus during early pregnancy. Mmu-miR-486-3p expression was significantly increased during the peri-implantation period, and the levels were significantly higher at implantation than at non-implantation sites. In contrast, the expression of mmu-miR-3074-5p was markedly decreased at implantation compared to non-implantation sites. These data suggest that miR-486-3p and miR-3074-5p may be involved in embryo implantation and that their aberrant expression is associated with RM. Larger studies are warranted to follow up this pilot study. © 2015 S. Karger AG, Basel.

First-trimester maternal cell microRNA is a superior pregnancy marker to immunological testing for predicting adverse pregnancy outcome

Patients at risk of immune-mediated pregnancy complications have historically relied on the use of peripheral blood immunological assays for diagnosis and pregnancy monitoring. However, these tests often fail to identify many at-risk patients, achieving moderately predictive receiver operating characteristic (ROC) curve AUCs of 0.60-0.70. We previously demonstrated that a microRNA panel comprising 30 microRNAs successfully predicts pregnancy outcome in the first trimester. In our current study we constructed a smaller, more clinically useful seven-microRNA panel from the original panel of 30 microRNAs with equivalent sensitivity and specificity. To select optimal microRNAs for a smaller panel, quantitative RT-PCR on 30 microRNAs was first performed on 48 patients (191 samples) with concurrent immunological testing: TNFα/Il-10 ratio, IFNγ/Il-10, CD56+16+%, NK 50:1 cytotoxicity and T regulatory cells. MicroRNAs were separated into clusters associated with: Th1/Th2 response; T regulatory cell percent; pregnancy risk; treatment response. Seven most differentially expressed microRNAs were selected. The seven microRNA scoring system was then applied to 39 patient samples in the first trimester of pregnancy (19 healthy deliveries, 8 miscarriages, 12 preeclampsia [7 late-onset and 5 early-onset]) and 20 samples in the preconception period (2-10 weeks before conception). Predictive value was assessed. ROC curves for the seven-microRNA panel achieved AUC 0.92 for miscarriage and 0.90 for preeclampsia (blood drawn 34.9±19.2 days post-implantation). For samples measured preconception, ROC curve analysis demonstrated AUC 0.81 for adverse pregnancy outcome. Maternal PBMC microRNA can identify high-risk patients likely to benefit from immunotherapy with improved sensitivity and specificity compared with standard immune assays.

First trimester screening of circulating C19MC microRNAs can predict subsequent onset of gestational hypertension

OBJECTIVE

The objective of the study was to evaluate risk assessment for gestational hypertension based on the profile of circulating placental specific C19MC microRNAs in early pregnancy.

STUDY DESIGN

The prospective longitudinal cohort study of women enrolled at first trimester screening at 10 to 13 weeks was carried out (n = 267). Relative quantification of placental specific C19MC microRNAs (miR-516-5p, miR-517*, miR-518b, miR-520a*, miR-520h, miR-525 and miR-526a) was determined in 28 normal pregnancies and 18 pregnancies which developed gestational hypertension using real-time PCR and a comparative Ct method relative to synthetic C. elegans microRNA (cel-miR-39).

RESULTS

Increased extracellular C19MC microRNA plasmatic levels (miR-516-5p, p<0.001; miR-517*, p = 0.007; miR-520h, p<0.001; miR-518b, p = 0.002) were detected in patients destined to develop gestational hypertension. MiR-520h had the best predictive performance with a PPV of 84.6% at a 7.1% false positive rate. The combination of miR-520h and miR-518b was able to predict 82.6% of women at the same false positive rate. The overall predictive capacity of single miR-518b (73.3% at 14.3% FPR), miR-516-5p (70.6% at 17.9% FPR) and miR-517* (57.9% at 28.6% FPR) biomarkers was lower.

CONCLUSION

The study brought interesting finding that the up-regulation of miR-516-5p, miR-517*, miR-520h and miR-518b is associated with a risk of later development of gestational hypertension. First trimester screening of extracellular miR-520h alone or in combination with miR-518b identified a significant proportion of women with subsequent gestational hypertension.