MicroRNA expression profiles in placenta with severe preeclampsia using a PNA-based microarray

Expression profiles of candidate microRNAs in the peripheral blood leukocytes of patients with early- and late-onset preeclampsia versus normal pregnancies

OBJECTIVES

Maternal leucocytes play an important role in the pathogenesis of preeclampsia (PE). Circulating microRNAs (miRNAs) are small, noncoding RNA molecules. The purpose of this study was to investigate miR-518b, miR-155-5p, and miR-21-3p in the peripheral blood leukocytes of patients with PE, compared to controls.

STUDY DESIGN

Using real-time quantitative PCR method, the selected miRNAs which have been associated with PE were examined from early- onset PE (EOPE) (<34 weeks) (n = 48), late- onset PE (LOPE) (≥34 weeks) (n = 48), total cases of PE (n = 96), and healthy controls (n = 52).

MAIN OUTCOME MEASURES

The relative expression of the target miR in patient samples was compared to the calibrator and the results were expressed as relative quantification values.

RESULTS

Gestational age (GA) was significantly different between PE and controls. Univariate logistic regression analysis adjusted for GA at blood draw were fit to compare miR-518b, miR-155-5p, and miR-21-3p between PE and controls. The expression of miR-518b, miR-155-5p, and miR-21-3p were not significantly different in PE, compared to controls. The expression of miR-518b was upregulated in the EOPE and LOPE group, compared to controls, and the area under the receiver operating characteristic curve (AUC) of miR-518b was 0.65 and 0.62, respectively. miR-518b was positively correlated with WBC count, platelet count, serum levels of AST, ALT, LDH in EOPE. miR-21-3p expression level was negatively correlated with body mass index at blood draw and systolic blood pressure in the LOPE group.

CONCLUSIONS

Increased miR-518b expression levels were found to be associated with EOPE and LOPE.

ROS/p53/miR‑335‑5p/Sp1 axis modulates the migration and epithelial to mesenchymal transition of JEG‑3 cells

Differential expression of microRNA (miR)-335-5p, a key tumor suppressor, has been detected in pre-eclampsia (PE) placentas. However, the role of miR-335-5p in the pathogenesis of PE and the factor modulating its aberrant expression remain unknown. The present study used JEG-3 cells in vitro to investigate these mechanisms. The role of miR-335-5p in proliferation, apoptosis and migration of JEG-3 cells was investigated using MTT, Annexin V-FITC/PI, Transwell migration and wound healing assays, respectively. miR-335-5p expression levels were analyzed using reverse transcription-quantitative PCR. The expression levels of E-cadherin, N-cadherin, Snail, specificity protein 1 (Sp1) and p53 were assessed using western blot analysis. Cell viability analysis was performed using the Cell Counting Kit-8 assay. The intracellular reactive oxygen species (ROS) levels were detected using a 2,7-dichlorodihydrofluorescein diacetate assay. The present results suggested that miR-335-5p did not affect the proliferation or apoptotic rate of JEG-3 cells. Overexpression of miR-335-5p significantly inhibited the migration of JEG-3 cells, decreased the expression levels of Sp1, N-cadherin and Snail, and increased E-cadherin expression. Sp1 silencing produced similar results in JEG-3 cells. H₂O₂ significantly increased the intracellular ROS levels and miR-335-5p expression, whereas N-acetyl-cysteine pretreatment prior to H₂O₂ treatment reversed the increases in miR-335-5p expression. Knockdown of p53 significantly decreased the expression levels of miR-335-5p in JEG-3 cells and in H₂O₂-treated cells. The present results suggested that miR-335-5p expression levels in trophoblast cells could be increased by ROS in a p53-dependent manner, leading to the downregulation of Sp1 and subsequent inhibition of epithelial to mesenchymal transition and cell migration. The present results may provide novel evidence on the etiology of PE.

MiR-342-3p inhibition promotes cell proliferation and invasion by directly targeting ID4 in pre-eclampsia

AIM

This study aimed to explore the miR-342-3p expression in pre-eclampsia (PE) placentas and confirm whether miR-342-3p exerts effects on proliferation and migration of HTR-8/SVneo trophoblastic cells.

METHODS

The PE placentas (n = 8) were taken from gravidas complicated by PE and delivered after 34 weeks. The chorionic plates and the basal plates were separately taken from the placenta disc near the position of umbilical cord insertion. RT-qPCR was used to measure the expression of miR-342-3p in the chorionic plates and the basal plates. Cell invasion assay and MMT assay were used to assess the effects of miR-342-3p on proliferation and migration of HTR-8/SVneo trophoblastic cells. Luciferase reporter assay and Western blotting were used to analyze the target of miR-342-3p and investigate the detailed mechanisms.

RESULTS

The expression of miR-342-3p was upregulated in both basal plates and chorionic plates in patients with PE compared with healthy pregnant individuals. MiR-342-3p inhibitor suppressed the cell viability and invasion, and induced apoptosis in trophoblast cells. Furthermore, inhibitor of DNA binding (ID)-4 (ID4) was a direct target of miR-342-3p, and knockdown of ID4 abrogated the regulation effect of miR-342-3p on cell viability, apoptosis and invasion.

CONCLUSION

Inhibition of miR-342-3p expression may suppress the occurrence of PE by targeting ID4 in vitro.

MicroRNAs in Uteroplacental Vascular Dysfunction

Pregnancy complications of preeclampsia and intrauterine growth restriction (IUGR) are major causes of maternal and perinatal/neonatal morbidity and mortality. Although their etiologies remain elusive, it is generally accepted that they are secondary to placental insufficiency conferred by both failure in spiral artery remodeling and uteroplacental vascular malfunction. MicroRNAs (miRNAs) are small no-coding RNA molecules that regulate gene expression at the post-transcriptional level. Increasing evidence suggests that miRNAs participate in virtually all biological processes and are involved in numerous human diseases. Differentially expressed miRNAs in the placenta are typical features of both preeclampsia and IUGR. Dysregulated miRNAs target genes of various signaling pathways in uteroplacental tissues, contributing to the development of both complications. In this review, we provide an overview of how aberrant miRNA expression in preeclampsia and IUGR impacts the expression of genes involved in trophoblast invasion and uteroplacental vascular adaptation.

Epigenetic Biomarkers in Cardiovascular Diseases

Cardiovascular diseases are the number one cause of death worldwide and greatly impact quality of life and medical costs. Enormous effort has been made in research to obtain new tools for efficient and quick diagnosis and predicting the prognosis of these diseases. Discoveries of epigenetic mechanisms have related several pathologies, including cardiovascular diseases, to epigenetic dysregulation. This has implications on disease progression and is the basis for new preventive strategies. Advances in methodology and big data analysis have identified novel mechanisms and targets involved in numerous diseases, allowing more individualized epigenetic maps for personalized diagnosis and treatment. This paves the way for what is called pharmacoepigenetics, which predicts the drug response and develops a tailored therapy based on differences in the epigenetic basis of each patient. Similarly, epigenetic biomarkers have emerged as a promising instrument for the consistent diagnosis and prognosis of cardiovascular diseases. Their good accessibility and feasible methods of detection make them suitable for use in clinical practice. However, multicenter studies with a large sample population are required to determine with certainty which epigenetic biomarkers are reliable for clinical routine. Therefore, this review focuses on current discoveries regarding epigenetic biomarkers and its controversy aiming to improve the diagnosis, prognosis, and therapy in cardiovascular patients.

MicroRNAs: Small molecules with a large impact on pre-eclampsia

As critical mediators in biological processes, microRNAs (miRNAs) which are small and endogenous noncoding RNAs have been associated with disease progression, cell proliferation, and development. Pre-eclampsia (PE), a pregnancy-related disorder with no early markers or symptoms is recognized as the main reason for fetal and maternal mortality and morbidity in the initial steps or even during pregnancy, worldwide. Clinical symptoms usually appear in the third trimester of the pregnancy. Although numerous research have unraveled several aspects of placenta development abnormalities associated with abnormal trophoblastic invasion and angiogenesis modification, many questions about the PE pathogenesis remains unanswered. A large number of studies have shown the important role of miRNAs as potential biomarkers in the PE prognosis and diagnosis. Here, the latest investigations about the PE and placental miRNAs expression, as well as, the crucial role of miRNA molecules including miR-210 and miR-155 which are deregulated in patients with PE, will be argued.

[Vitamin D down-regulates microRNA-21 expression to promote human placental trophoblast cell migration and invasion in vitro]

OBJECTIVE

To investigate the effect of vitamin D on microRNA-21(miR-21) expression and migration and invasion of human placental trophoblast cells.

METHODS

The changes in the expression of miR-21 were detected using RT-qPCR in HTR-8/SVneo cells following stimulation by vitamin D at different doses for 24, 48 and 72 h.HTR-8/SVneo cells transfected with miR-21 mimic or inhibitor with or without vitamin D treatment were examined for changes in cell migration and invasion abilities using Transwell assay, and Western blotting was used to detect protein expressions of E-cadherin, fibronectin, and MMP9.

RESULTS

Vitamin D obviously inhibited the expression of micoRNA-21 in HTR-8/SVneo cells in a concentration-and time-dependent manner.Transfection with the miR-21 mimic significantly inhibited the migration and invasion of HTR-8/SVneo cells, and this inhibitory effect was abolished by treatment with vitamin D; transfection with miR-21 inhibitor obviously promoted the migration and invasion of HTR-8/SVneo cells, and these effects were not significantly affected by vitamin D treatment.

CONCLUSIONS

Vitamin D may promote trophoblast cell migration and invasion to accelerate the development of preeclampsia by down-regulating the expression of miR-21.

Clinical value of microRNA-198-5p downregulation in lung adenocarcinoma and its potential pathways

Lung adenocarcinoma (LUAD), the main subtype of non-small cell lung cancer, is known to be regulated by various microRNAs (miRs/miRNAs); however, the role of miR-198-5p in LUAD has not been clarified. In the present study, the clinical value of miR-198-5p in LUAD and its potential molecular mechanism was evaluated. miR-198-5p expression was examined by reverse transcription-quantitative PCR (RT-qPCR) in 101 paired LUAD and adjacent normal lung tissues. Subsequently, the miR-198-5p expression level was determined from microarray data from the Gene Expression Omnibus, ArrayExpress and by meta-analyses. Furthermore, the target mRNAs of miR-198-5p from 12 miRNA-mRNA predictive tools were intersected with The Cancer Genome Atlas (TCGA)-based differentially expressed genes. In addition, Gene Ontology annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were conducted to determine the possible mechanism of miR-198-5p in LUAD. The Search Tool for the Retrieval of Interacting Genes/Proteins database was employed to construct a protein-protein interaction network among the potential target genes of miR-198-5p. The results showed that miR-198-5p expression was lower in LUAD tissues than in adjacent non-cancerous lung tissues (4.469±2.495 vs. 5.301±2.502; P=0.015). Meta-analyses, including the data from the present study and online microarray data, also verified the downregulation of miR-198-5p in 584 cases of LUAD. The expression of miR-198-5p was associated with the age, blood vessel invasion, Tumor-Node-Metastasis stage, and lymph node metastasis of patients with LUAD and served as an independent prognostic factor for survival. The hub genes of miR-198-5p were upregulated in LUAD, according to TCGA and The Human Protein Atlas. For the KEGG pathway analysis, the most enriched KEGG pathway was the p53 signaling pathway (P=1.42×10⁻⁶). These findings indicated that the downregulation of miR-198-5p may play a pivotal role in the development of LUAD by targeting various signaling pathways.

Endocervical trophoblast for interrogating the fetal genome and assessing pregnancy health at five weeks

Prenatal testing for fetal genetic traits and risk of obstetrical complications is essential for maternal-fetal healthcare. The migration of extravillous trophoblast (EVT) cells from the placenta into the reproductive tract and accumulation in the cervix offers an exciting avenue for prenatal testing and monitoring placental function. These cells are obtained with a cervical cytobrush, a routine relatively safe clinical procedure during pregnancy, according to published studies and our own observations. Trophoblast retrieval and isolation from the cervix (TRIC) obtains hundreds of fetal cells with >90% purity as early as five weeks of gestation. TRIC can provide DNA for fetal genotyping by targeted next-generation sequencing with single-nucleotide resolution. Previously, we found that known protein biomarkers are dysregulated in EVT cells obtained by TRIC in the first trimester from women who miscarry or later develop intrauterine growth restriction or preeclampsia. We have now optimized methods to stabilize RNA during TRIC for subsequent isolation and analysis of trophoblast gene expression. Here, we report transcriptomics analysis demonstrating that the expression profile of TRIC-isolated trophoblast cells was distinct from that of maternal cervical cells and included genes associated with the EVT phenotype and invasion. Because EVT cells are responsible for remodeling the maternal arteries and their failure is associated with pregnancy disorders, their molecular profiles could reflect maternal risk, as well as mechanisms underlying these disorders. The use of TRIC to analyze EVT genomes, transcriptomes and proteomes during ongoing pregnancies could provide new tools for anticipating and managing both fetal genetic and maternal obstetric disorders.

miR‑342‑3p suppresses cell migration and invasion in preeclampsia by targeting platelet‑derived growth factor receptor α

miR-342-3p expression was increased in the placentas of women with preeclampsia (PE) according to previous examinations; the mechanism underlying the development and progression of PE requires further investigation. The present study aimed to explore the mechanism and functionality of microRNA (miR)-342-3p in trophoblastic cells. The expression of miR-342-3p and platelet-derived growth factor receptor α (PDGFRA) in the placentas of 30 patients with PE and 30 normal controls was detected. In addition, HTR8/SVneo cells were transfected with miR-342-3p mimics, small interfering RNA (siR)-PDGFRA or their corresponding negative controls; then the proliferation, migration, invasion and the distribution of the cell cycle of these cells were analyzed. Additionally, a dual-luciferase reporter assay was performed. According to these analyses, the expression of miR-342-3p was significantly increased, while that of PDGFRA was significantly lower in the PE group compared with the normal group. Transfection with miR-342-3p mimics led to a significant decrease in cell proliferation, migration and invasion, and also affected the cell cycle. Furthermore, miR-342-3p mimics reduced the expression of PDGFRA; miR-342-3p overexpression also reduced the mRNA and protein levels of BCL-2 and Caspase-3. In addition, transfection of siR-PDGFRA exhibited similar effects to those of miR-342-3p mimics. Finally, PDGFRA was reported to be a direct target of miR-342-3p. In conclusion, miR-342-3p was proposed to inhibit the proliferation, migration, invasion and G1/S phase transition of HTR8/SVneo cells by suppressing PDGFRA. Our findings suggest that miR-342-3p may be a novel clinical indicator or prognostic marker for PE.

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

MicroRNAs (miRNAs/miRs) are highly stable in circulating, which suppress target gene expression by base-pairing to the 3'-untranslated region. We compared the expressions of 3 circulating miRs (miR-31, miR-21, and miR-16), which are related to the control of cell apoptosis, invasion, angiogenesis and immune tolerance in non-pregnancy (n = 10), 20-34 gestational weeks normal pregnancy (20-34 GW NP, n = 20), early onset preeclampsia (EOPE, n = 20), 34-41 gestational weeks normal pregnancy (34-41 GW NP, n = 20) and late onset preeclampsia (LOPE, n = 20). Using quantitative RT-PCR, we found the levels of miR-31, miR-21 and miR-16 changed throughout different stages of pregnancy with the non-pregnancy as the calibrator. The plasma miR-31 levels were significantly down-regulated in EOPE rather than in LOPE when compared to gestational age matched normal pregnancy (P < 0.001). MiR-21 levels were significantly lower in LOPE compared to healthy controls (P < 0.001), while no significant difference was found between EOPE and 20-34 gestational weeks normal pregnancy (P = 0.376). The miR-16 expressions were at similar levels between preeclampsia (PE) and normal pregnancy. Receiver operating characteristic (ROC) curve analyses indicated the miR-31 differentiated EOPE patients from healthy controls with an area under the curve (AUC) of 0.875 with 95.0% sensitivity and 70.0% specificity. ROC curves also discriminated the LOPE patients from healthy pregnancy with an AUC of 0.793, 65.1% sensitivity and 90.3% specificity for plasma miR-21 levels. This study is the first to demonstrate the difference, and circulating miR-31 may serve as a diagnostic biomarker for early onset preeclampsia meanwhile miR-21 might be a diagnostic biomarker for late onset preeclampsia.

Differential expression of candidate circulating microRNAs in maternal blood leukocytes of the patients with preeclampsia and gestational diabetes mellitus

OBJECTIVES

Preeclampsia (PE) is diagnosed in women presenting with new onset hypertension accompanied by proteinuria. Gestational diabetes mellitus (GDM) is the carbohydrate intolerance that can occur in pregnancy. Neutrophil activation is related to PE and GDM. Circulating microRNAs (miRs) are small, noncoding RNA molecules. The aim of this study was to verify the expression levels of three candidate miRs in blood leukocytes of the patients with PE, GDM, and PE-GDM compared to healthy controls.

STUDY DESIGN

We selected miR-21-3p, miR-155-5p, and miR-16-5p which have been associated with GDM and PE. Using real-time quantitative PCR, the expression levels of miR-21-3p, miR-155-5p, miR-16-5p were analyzed in PE (n = 23), GDM (n = 19), PE, and GDM (n = 9) compared to healthy controls (n = 28).

MAIN OUTCOME MEASURES

The relative expression of the target miR in patient samples was compared to the calibrator and the results were expressed as relative quantification values.

RESULTS

There was a significant decrease in the expression levels of miR-21-3p in GDM and PE and miR-155-5p in PE group. No significant differences were observed in the expression levels of miRs in PE-GDM group. On receiving operator characteristic (ROC) analysis, areas under the curve (AUC) of the expression ratio of miR-21-3p in GDM was 0.73, and miR-21-3p, miR-155-5p in PE were 0.69 and 0.81, respectively.

CONCLUSIONS

Our findings indicated that decreased miR-21-3p and miR-155-5p expression levels are associated with PE and miR-21-3p levels are associated with GDM. Our study for the first time revealed that miR-21-3p, miR-16-5p and miR155-5p are not related to PE-GDM group.

MicroRNA‑144‑3p may participate in the pathogenesis of preeclampsia by targeting Cox‑2

Preeclampsia remains a major cause of maternal mortality and morbidity worldwide. It is generally accepted that the development of the placenta, including spiral artery remodelling, normal trophoblast cells function and maternal-fetal inflammation-immune interactions, is critical for the pathogenesis of preeclampsia. Several investigations have demonstrated that microRNAs (miRNAs/miRs) in the placenta may be potential molecular markers for diagnosis of preeclampsia. In the current study, the aim was to investigate the expression of miR-144-3p in the placenta of patients with preeclampsia and normal placentas, and to explore the potential target genes. miRNA microarray analysis was performed using three paired placentas (preeclampsia and normal) in order to find differential expression of miRNAs. Following this, miR-144-3p was selected as a differentially expressed miRNA and validated using in situ hybridization to determine the clinical significance in placentas with preeclampsia. A potential target gene of miR-144-3p, cyclooxygenase-2 (Cox-2), was identified by bioinformatics, luciferase reporter assay and western blotting. The expression of Cox-2 was also examined by immunohistochemical staining of samples of placenta from patients with preeclampsia and normal placenta. Western blot analysis was performed to investigate the effect of miR-144-3p on the expression of Cox-2 in HTR-8/SVneo cells in vitro. miR-144-3p was decreased in placentas from patients with preeclampsia. A luciferase reporter assay demonstrated that Cox-2 was a potential miR-144-3p target gene and the result was verified by western blotting. A negative correlation was observed between miR-144-3p and Cox-2 in preeclamptic placenta by immunohistochemical staining and in situ hybridization. Western blot analysis demonstrated that overexpression of miR-144-3p decreased Cox-2 expression by 38.2% in HTR-8/SVneo cells. Understanding the differential expression of miR-144-3p and its association with Cox-2 may aid the exploration of the pathogenesis of preeclampsia, and contribute to the development of miRNA-based therapies in the future.

Maternal circulating miRNAs that predict infant FASD outcomes influence placental maturation

Maternal gestational circulating microRNAs, predictive of adverse infant outcomes, including growth deficits, following prenatal alcohol exposure, contribute to placental pathology by impairing the EMT pathway in trophoblasts.

Prenatal alcohol exposure (PAE), like other pregnancy complications, can result in placental insufficiency and fetal growth restriction, although the linking causal mechanisms are unclear. We previously identified 11 gestationally elevated maternal circulating miRNAs (_HEamiRNAs) that predicted infant growth deficits following PAE. Here, we investigated whether these _HEamiRNAs contribute to the pathology of PAE, by inhibiting trophoblast epithelial–mesenchymal transition (EMT), a pathway critical for placental development. We now report for the first time that PAE inhibits expression of placental pro-EMT pathway members in both rodents and primates, and that _HEamiRNAs collectively, but not individually, mediate placental EMT inhibition. _HEamiRNAs collectively, but not individually, also inhibited cell proliferation and the EMT pathway in cultured trophoblasts, while inducing cell stress, and following trophoblast syncytialization, aberrant endocrine maturation. Moreover, a single intravascular administration of the pooled murine-expressed _HEamiRNAs, to pregnant mice, decreased placental and fetal growth and inhibited the expression of pro-EMT transcripts in the placenta. Our data suggest that _HEamiRNAs collectively interfere with placental development, contributing to the pathology of PAE, and perhaps also, to other causes of fetal growth restriction.

Long non-coding RNA TUG1 regulates the migration and invasion of trophoblast-like cells through sponging miR-204-5p

Preeclampsia (PE) is a leading cause of maternal and perinatal death. Accumulated evidence suggests that many long non-coding RNAs (lncRNAs) are abnormally expressed in placentas from PE patients, and they may play functional roles in the development of PE. The present study aimed to investigate the functional role TUG1 in PE and explore the potential molecular mechanisms. Clinically, the expression of TUG1 in placental tissues from PE and normal controls was determined. In vitro, human trophoblast HTR-8/SVneo and JAR cells were employed for loss or gain-of-function assays. Our results demonstrate that TUG1 was downregulated in PE placental tissues compared with normal controls. Moreover, downregulation of TUG1 inhibited the migration and invasion of trophoblast-like cells. Bioinformatics analysis and functional assays showed that TUG1 interacted with miR-204-5p and negatively regulated the expression and function of miR-204-5p in trophoblast cells. Furthermore, TUG1-mediated migration and invasion of trophoblast cells was regulated by miR-204-5p. Together, our results suggested that TUG1 regulates trophoblast migration and invasion partly through sponging miR-204-5p, and the TUG1/miR-204-5p axis could be a potential therapeutic target for the treatment of PE.

Circulating Exosomal miRNA Profile During Term and Preterm Birth Pregnancies: A Longitudinal Study

Despite decades of research in the field of human reproduction, the mechanisms responsible for human parturition still remain elusive. The objective of this study was to describe the changes in the exosomal miRNA concentrations circulating in the maternal plasma between mothers delivering term and preterm neonates, across gestation using a longitudinal study design. This descriptive study identifies the miRNA content in exosomes present in maternal plasma of term and preterm birth (PTB) (n = 20 and n = 10 per each gestational period, respectively) across gestation (i.e., first, second, and third trimesters and at the time of delivery). Changes in exosomal miRNA signature in maternal plasma during term and preterm gestation were determined using the NextSeq 500 high-output 75 cycles sequencing platform. A total of 167 and 153 miRNAs were found to significantly change (P < 0.05) as a function of the gestational age across term and PTB pregnancies, respectively. Interestingly, a comparison analysis between the exosomal miRNA profile between term and PTB reveals a total of 173 miRNAs that significantly change (P < 0.05) across gestation. Specific trends of changes (i.e., increase, decrease, and both) as a function of the gestational age were also identified. The bioinformatics analyses establish that the differences in the miRNA profile are targeting signaling pathways associated with TGF-β signaling, p53, and glucocorticoid receptor signaling, respectively. These data suggest that the miRNA content of circulating exosomes in maternal blood might represent a biomolecular "fingerprint" of the progression of pregnancy.

Trophoblastic microRNAs are downregulated in a diabetic pregnancy through an inhibition of Drosha

MicroRNAs are promising biological markers for prenatal diagnosis. They regulate placental development and are present in maternal plasma. Maternal metabolic diseases are major risk factors for placental deterioration. We analysed the influence of a maternal insulin-dependent diabetes mellitus on microRNA expression in maternal plasma and in blastocysts employing an in vivo rabbit diabetic pregnancy model and an in vitro embryo culture in hyperglycaemic and hypoinsulinaemic medium. Maternal diabetes led to a marked downregulation of Dicer protein in embryoblast cells and Drosha protein in trophoblast cells. MiR-27b, miR-141 and miR-191 were decreased in trophoblast cells and in maternal plasma of diabetic rabbits. In vitro studies indicate, that maternal hyperglycaemia and hypoinsulinaemia partially contribute to the downregulation of trophoblastic microRNAs. As the altered microRNA expression was detectable in maternal plasma, too, the plasma microRNA signature could serve as an early biological marker for the prediction of trophoblast function during a diabetic pregnancy.

MiRNA-548c-5p downregulates inflammatory response in preeclampsia via targeting PTPRO

Preeclampsia is a serious complication of pregnancy and leads to maternal hypertension and proteinuria. It remains a major health problem for mothers and babies across the world due to high maternal and fetal morbidity and mortality. Accumulated data have implicated the critical role of microRNA in preeclampsia. However, to date, the role of miR-548c-5p in preeclampsia remains vaguely understood. In this study, we first elucidate the role of miR-548c-5p and its underlying molecular mechanism in preeclampsia. Compared with healthy controls, miR-548c-5p was obviously downregulated in serum exosomes and placental mononuclear cells in patients with preeclampsia. Nonetheless, PTPRO was significantly upregulated and negatively associated with miR-548c-5p in placental mononuclear cells in patients with preeclampsia. PTPRO was a target of miR-548c-5p. PTPRO was downregulated in the miR-548c-5p-overexpressed macrophages. In addition, miR-548c-5p could inhibit the proliferation and activation of LPS-stimulated macrophages, as evidenced by decreased levels of inflammatory cytokines (IL-12 and TNF-α) and less nuclear translocation of pNF-κB in pTHP1 cells. MiR-548c-5p acts as an anti-inflammatory factor in preeclampsia. The axis of miR-548c-5p/PTPRO/NF-κB may provide novel targets for the diagnosis and treatment of preeclampsia.

Molecular determinants of microvascular dysfunction in hypertensive pregnancy and preeclampsia

Preeclampsia is a pregnancy-related disorder characterized by hypertension and often fetal intrauterine growth restriction, but the underlying mechanisms are unclear. Defective placentation and apoptosis of invasive cytotrophoblasts cause inadequate remodeling of spiral arteries, placental ischemia, and reduced uterine perfusion pressure (RUPP). RUPP causes imbalance between the anti-angiogenic factors soluble fms-like tyrosine kinase-1 and soluble endoglin and the pro-angiogenic vascular endothelial growth factor and placental growth factor, and stimulates the release of proinflammatory cytokines, hypoxia-inducible factor, reactive oxygen species, and angiotensin AT1 receptor agonistic autoantibodies. These circulating factors target the vascular endothelium, smooth muscle and various components of the extracellular matrix. Generalized endotheliosis in systemic, renal, cerebral, and hepatic vessels causes decreases in endothelium-derived vasodilators such as nitric oxide, prostacyclin and hyperpolarization factor, and increases in vasoconstrictors such as endothelin-1 and thromboxane A2. Enhanced mechanisms of vascular smooth muscle contraction, such as intracellular Ca2+ , protein kinase C, and Rho-kinase cause further increases in vasoconstriction. Changes in matrix metalloproteinases and extracellular matrix cause inadequate vascular remodeling and increased arterial stiffening, leading to further increases in vascular resistance and hypertension. Therapeutic options are currently limited, but understanding the molecular determinants of microvascular dysfunction could help in the design of new approaches for the prediction and management of preeclampsia.

Preeclampsia and the challenge of early prediction: reality or utopia? State of art and critical review of literature

Purpose: The challenge to obtain improved predictive tools, able to identify women destined to develop preeclampsia (PE), is raising the interest of researchers for the attractive chance to allow for timely initiation of prophylactic therapy, appropriate antenatal surveillance, and better-targeted research into preventive interventions. We aimed to gather all the evidence reported up to now in scientific literature relating to all prediction tests for PE.Materials and methods: We searched articles on conventional literature platforms from January 1952 to August 2016, using the terms "preeclampsia," "gestational preeclampsia," and "gestational hypertensive disorders" combined with "predictive test" and "risk assessment." Abstracts/titles identified by the search were screened by three investigators.Results: The search identified 203 citations, of which 154 potentially relevant after the initial evaluation. Among these studies, 20 full articles were excluded, therefore, 134 primary studies met the criteria for inclusion and were analyzed.Conclusions: Current evidence suggests that a combination of several features may provide the best predictive accuracy for the identification of PE. Large-scale, multicenter, multiethnic, prospective trials are required to propose an ideal combination of markers for routine screening.

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.

Cardiac remodeling and pre-eclampsia: an overview of microRNA expression patterns

Pre-eclampsia (PE) is strongly associated with heart failure (HF) later in life. During PE pregnancy, the left ventricle undergoes concentric remodeling which often persists after delivery. This aberrant remodeling can induce a molecular signature that can be evaluated in terms of microRNAs (miRNAs) and which may help to explain the associated increased risk of HF. For this review, we performed a literature search of PubMed (National Center for Biotechnology Information), identifying studies on miRNA expression in concentric remodeling and on miRNA expression in PE. The miRNA data were stratified based on origin (isolated from humans or animals and from tissue or the circulation) and both datasets compared in order to generate a list of miRNA expression patterns in concentric remodeling and in PE. The nine miRNAs identified in both concentric remodeling and PE-complicated pregnancy were: miR-1, miR-18, miR-21, miR-29b, miR-30, miR-125b, miR-181b, miR-195 and miR-499-5p. We found five of these miRNAs (miR-18, miR-21, miR-125b, miR-195 and miR-499-5p) to be upregulated in both PE pregnancy and cardiac remodeling and two (miR-1 and miR-30) to be downregulated in both; the remaining two miRNAs (miR-29b and miR-181b) showed upregulation during PE but downregulation in cardiac remodeling. This innovative approach may be a step towards finding relevant biomarkers for complicated pregnancy and elucidating their relationship with remote cardiovascular disease. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Regulation of birthweight by placenta-derived miRNAs: evidence from an arsenic-exposed birth cohort in Bangladesh

Altered expression of microRNAs (miRNAs) is implicated in fetal growth. However, the mechanisms by which placenta-derived miRNAs regulate birthweight are not well understood. In Phase 1, we compared the expression of 754 miRNAs in the placenta of mothers from two extreme birthweight groups (0.8-2.2 kg vs. 3.3-3.9 kg, n = 77 each) selected from an arsenic-exposed Bangladeshi birth cohort (n = 1,141). We identified 49 miRNAs associated with the extreme birthweight groups and/or gestational age in Phase 1, which were further analyzed in Phase 2 among 364 randomly selected mother-infant pairs. Gestational age was determined by ultrasound. Causal mediation analysis was used to estimate the effect of miRNAs on birthweight considering gestational age a mediator, adjusting for core blood arsenic and other risk factors. miR-1290, miR-195, and let-7g showed significant inverse associations with gestational age, while miR-328 showed significant positive association [false discovery rate (FDR) <0.05]. Via changing gestational age, miR-1290, miR-195, and miR-27a showed significant inverse associations with birthweight, while miR-328 and miR-324-5p showed significant positive associations (FDR <0.05). The effect of miRNAs on birthweight varied by gestational age (for miR-1290, miR-195, miR-328) and in utero arsenic exposure (for miR-1290): stronger effect was observed among infants delivered early in gestation or exposed to higher concentrations of arsenic in cord blood. Gene enrichment analysis with in silico predicted targets identified cell proliferation, inflammation, apoptosis, insulin, and IGF family signaling cascades associated with these miRNAs. Future studies are warranted to replicate these findings and assess these miRNAs as early biomarkers of fetal growth.

The association of pri-miRNA- 26a1 rs7372209 polymorphism and Preeclampsia susceptibility

MicroRNAs (miRNAs) are a class of noncoding small RNAs which regulate gene expression through post-transcriptional repression or degradation of messenger RNA. They play very important roles in various biological processes including growth, differentiation, and proliferation, as well as apoptosis, angiogenesis, and metabolism. Therefore, in the present study, we evaluated the possible effect of functional rs7372209C/T polymorphism in the 5'- region of pri-miRNA- 26a1gene on preeclampsia(PE) susceptibility. This case-control study was conducted on 219 PE women and 204 unrelated healthy controls. The amplification refractory mutation system-polymerase chain reaction method was used for rs7372209C/T genotyping. The pri-miRNA- 26a1 rs7372209CT genotype was associated with decreased PE risk (OR, 0.5 [95% CI, 0.3-0.8], P = 0.001). The frequency of rs7372209TT genotype did not differ between two groups. In addition, the pri-miRNA- 26a1 rs7372209 polymorphism was associated with lower risk of PE in dominant model (CT+TT vs CC) (OR, 0.5 [95% CI, 0.4-0.8], P = 0.002). Although there was no significant difference between mild and severe PE women according to rs7372209CT genotype, the differences between mild and severe PE groups with controls remained significant. The frequency of pri-miRNA-26a1 rs7372209CT genotype was not different between late-onset PE and early onset PE groups. The present study showed for the first time that the pri-miRNA- 26a1 rs7372209 polymorphism was associated with lower risk of mild and severe PE in the dominant model and this polymorphism could be a protective factor for PE susceptibility.

Competing endogenous RNA expression profiling in pre-eclampsia identifies hsa_circ_0036877 as a potential novel blood biomarker for early pre-eclampsia

Background

The etiology and pathogenesis of pre-eclampsia (PE) is unclear, and there is no ideal early clinical biomarker for prediction of PE. The competing endogenous RNA (ceRNA) hypothesis is a new approach to uncover the molecular pathology of PE. The first aim of this study was to perform messenger RNA, long non-coding RNA, and circular RNA (circRNA) expression profiling of human normal and severe pre-eclampsia (SPE) placentas. circRNA, which has a stable structure, is a more suitable biomarker than other types of RNA. Therefore, the second aim of our study was to select some differentially expressed circRNAs in PE placentas as early clinical biomarkers of PE in blood circulation.

Results

Using microarray analysis, we investigated differentially expressed ceRNAs in human normal and SPE placentas. Bioinformatics, such as gene ontology, KEGG pathway, and ceRNA network analyses, were performed to evaluate the microarray data and gain further insights into the biological processes. RNAs (Chd5, Furin, lnc-ELAVL4-9:1, lnc-RAP1GAP2-5:2, hsa_circ_0036877, hsa_circ_0036878, hsa_circ_0055724, hsa_circ_0049730, and hsa_circ_0036474) were validated by quantitative real-time PCR (qRT-PCR). RNA immunoprecipitation (RIP) of AGO2 in htra-8 cells and qRT-PCR analysis of hsa_circ_0036877 expression in maternal whole peripheral blood samples of participants were then conducted to confirm that hsa_circ_0036877 is a ceRNA and potential novel blood biomarker for early PE, respectively.

Conclusion

Our study is the first systematic profiling of ceRNAs in placentas of PE patients and revealed the global ceRNA network integration in PE. Moreover, hsa_circ_0036877 can function as a ceRNA and serve as a potential novel blood biomarker for early PE.

Electronic supplementary material

The online version of this article (10.1186/s13148-018-0482-3) contains supplementary material, which is available to authorized users.

Circulating microRNAs as biomarkers of disease and typification of the atherothrombotic status in antiphospholipid syndrome

We aimed to identify the plasma miRNA profile of antiphospholipid syndrome (APS) patients and to investigate the potential role of specific circulating miRNAs as non-invasive disease biomarkers. Ninety APS patients and 42 healthy donors were recruited. Profiling of miRNAs by PCR-array in plasma of APS patients identified a set of miRNAs differentially expressed and collectively involved in clinical features. Logistic regression and ROC analysis identified a signature of 10 miRNA ratios as biomarkers of disease. In addition, miRNA signature was related to fetal loss, atherosclerosis, and type of thrombosis, and correlated with parameters linked to inflammation, thrombosis, and autoimmunity. Hard clustering analysis differentiated 3 clusters representing different thrombotic risk profile groups. Significant differences between groups for several miRNA ratios were found. Moreover, miRNA signature remained stable over time, demonstrated by their analysis three months after the first sample collection. Parallel analysis in two additional cohorts of patients, including thrombosis without autoimmune disease, and systemic lupus erythematosus without antiphospholipid antibodies, each displayed specific miRNA profiles that were distinct from those of APS patients. In vitro, antiphospholipid antibodies of IgG isotype promoted deregulation in selected miRNAs and their potential atherothrombotic protein targets in monocytes and endothelial cells. Taken together, differentially expressed circulating miRNAs in APS patients, modulated at least partially by antiphospholipid antibodies of IgG isotype, might have the potential to serve as novel biomarkers of disease features and to typify patients’ atherothrombotic status, thus constituting a useful tool in the management of the disease.

Overexpression of preeclampsia induced microRNA-26a-5p leads to proteinuria in zebrafish

So far the pathomechanism of preeclampsia in pregnancy is focussed on increased circulating levels of soluble fms-like tyrosin kinase-1 (sFLT-1) that neutralizes glomerular VEGF-A expression and prevents its signaling at the glomerular endothelium. As a result of changed glomerular VEGF-A levels endotheliosis and podocyte foot process effacement are typical morphological features of preeclampsia. Recently, microRNA-26a-5p (miR-26a-5p) was described to be also upregulated in the preeclamptic placenta. We found that miR-26a-5p targets VEGF-A expression by means of PIK3C2α in cultured human podocytes and that miR-26a-5p overexpression in zebrafish causes proteinuria, edema, glomerular endotheliosis and podocyte foot process effacement. Interestingly, recombinant zebrafish Vegf-Aa protein could rescue glomerular changes induced by miR-26a-5p. In a small pilot study, preeclamptic patients with podocyte damage identified by podocyturia, expressed significantly more urinary miR-26a-5p compared to healthy controls. Thus, functional and ultrastructural glomerular changes after miR-26a-5p overexpression can resemble the findings seen in preeclampsia and indicate a potential pathophysiological role of miR-26a-5p in addition to sFLT-1 in this disease.

Early Detection of Preeclampsia Using Circulating Small non-coding RNA

Preeclampsia is one of the most dangerous pregnancy complications, and the leading cause of maternal and perinatal mortality and morbidity. Although the clinical symptoms appear late, its origin is early, and hence detection is feasible already at the first trimester. In the current study, we investigated the abundance of circulating small non-coding RNAs in the plasma of pregnant women in their first trimester, seeking transcripts that best separate the preeclampsia samples from those of healthy pregnant women. To this end, we performed small non-coding RNAs sequencing of 75 preeclampsia and control samples, and identified 25 transcripts that were differentially expressed between preeclampsia and the control groups. Furthermore, we utilized those transcripts and created a pipeline for a supervised classification of preeclampsia. Our pipeline generates a logistic regression model using a 5-fold cross validation on numerous random partitions into training and blind test sets. Using this classification procedure, we achieved an average AUC value of 0.86. These findings suggest the predictive value of circulating small non-coding RNA in the first trimester, warranting further examination, and lay the foundation for producing a novel early non-invasive diagnostic tool for preeclampsia, which could reduce the life-threatening risk for both the mother and fetus.

Clinical value of miR-198-5p in lung squamous cell carcinoma assessed using microarray and RT-qPCR

Background

To examine the clinical value of miR-198-5p in lung squamous cell carcinoma (LUSC).

Methods

Gene Expression Omnibus (GEO) microarray datasets were used to explore the miR-198-5p expression and its diagnostic value in LUSC. Real-time reverse transcription quantitative polymerase chain reaction was used to evaluate the expression of miR-198-5p in 23 formalin-fixed, paraffin-embedded (FFPE) LUSC tissues and corresponding non-cancerous tissues. The correlation between miR-198-5p expression and clinic pathological features was assessed. Meanwhile, putative target messenger RNAs of miR-198-5p were identified based on the analysis of differentially expressed genes in the Cancer Genome Atlas (TCGA) and 12 miRNA prediction tools. Subsequently, the putative target genes were sent to Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses.

Results

MiR-198-5p was low expressed in LUSC tissues. The combined standard mean difference (SMD) values of miR-198-5p expression based on GEO datasets were − 0.30 (95% confidence interval (CI) − 0.54, − 0.06) and − 0.39 (95% CI − 0.83, 0.05) using fixed effect model and random effect model, respectively. The sensitivity and specificity were not sufficiently high, as the area under the curve (AUC) was 0.7749 (Q* = 0.7143) based on summarized receiver operating characteristic (SROC) curves constructed using GEO datasets. Based on the in-house RT-qPCR, miR-198-5p expression was 4.3826 ± 1.7660 in LUSC tissues and 4.4522 ± 1.8263 in adjacent normal tissues (P = 0.885). The expression of miR-198-5p was significantly higher in patients with early TNM stages (I-II) than that in cases with advanced TNM stages (III-IV) (5.4400 ± 1.5277 vs 3.5690 ± 1.5228, P = 0.008). Continuous variable-based meta-analysis of GEO and PCR data displayed the SMD values of − 0.26 (95% CI − 0.48, − 0.04) and − 0.34 (95% CI − 0.71, 0.04) based on fixed and random effect models, respectively. As for the diagnostic value of miR-198-5p, the AUC based on the SROC curve using GEO and PCR data was 0.7351 (Q* = 0.6812). In total, 542 genes were identified as the targets of miR-198-5p. The most enriched Gene Ontology terms were epidermis development among biological processes, cell junction among cellular components, and protein dimerization activity among molecule functions. The pathway of non-small cell lung cancer was the most significant pathway identified using Kyoto Encyclopedia of Genes and Genomes analysis.

Conclusion

The expression of miR-198-5p is related to the TNM stage. Thus, miR-198-5p might play an important role via its target genes in LUSC.

Maternal Circulating microRNAs and Pre-Eclampsia: Challenges for Diagnostic Potential

Pre-eclampsia (PE) is a common hypertensive disorder of pregnancy with a significant impact on maternal and neonatal mortality and morbidity. While the pathogenesis of PE has been well described, identification of a biomarker(s) with robust predictive utility in identifying women at the highest risk of developing the condition has yet to be identified. In the search for diagnostic markers, those that may be obtained from the circulation are preferred alternatives to those derived from organ tissue samples. Because of their stability in plasma, microRNAs (miRNAs) have been explored as biomarkers in a host of disease states, although there is comparably little literature available on the circulating miRNAome of PE. This article provides a narrative review on the current state of knowledge on miRNAs associated with PE. Literature on circulating miRNAs is presented and the challenges to developing the diagnostic and prognostic utility of miRNAs in this context is discussed.

Matrix Metalloproteinases, Vascular Remodeling, and Vascular Disease

Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases that degrade various proteins in the extracellular matrix (ECM). Typically, MMPs have a propeptide sequence, a catalytic metalloproteinase domain with catalytic zinc, a hinge region or linker peptide, and a hemopexin domain. MMPs are commonly classified on the basis of their substrates and the organization of their structural domains into collagenases, gelatinases, stromelysins, matrilysins, membrane-type (MT)-MMPs, and other MMPs. MMPs are secreted by many cells including fibroblasts, vascular smooth muscle (VSM), and leukocytes. MMPs are regulated at the level of mRNA expression and by activation through removal of the propeptide domain from their latent zymogen form. MMPs are often secreted in an inactive proMMP form, which is cleaved to the active form by various proteinases including other MMPs. MMPs degrade various protein substrates in ECM including collagen and elastin. MMPs could also influence endothelial cell function as well as VSM cell migration, proliferation, Ca²⁺ signaling, and contraction. MMPs play a role in vascular tissue remodeling during various biological processes such as angiogenesis, embryogenesis, morphogenesis, and wound repair. Alterations in specific MMPs could influence arterial remodeling and lead to various pathological disorders such as hypertension, preeclampsia, atherosclerosis, aneurysm formation, as well as excessive venous dilation and lower extremity venous disease. MMPs are often regulated by endogenous tissue inhibitors of metalloproteinases (TIMPs), and the MMP/TIMP ratio often determines the extent of ECM protein degradation and tissue remodeling. MMPs may serve as biomarkers and potential therapeutic targets for certain vascular disorders.

Preeclampsia Downregulates MicroRNAs in Fetal Endothelial Cells: Roles of miR-29a/c-3p in Endothelial Function

CONTEXT

Preeclampsia is a leading cause of fetal and maternal morbidity and mortality during pregnancy. Although the etiology of preeclampsia is unknown, preeclampsia offspring have increased risks of developing cardiovascular disorders in adulthood, implicating that preeclampsia programs fetal vasculature in utero.

OBJECTIVE

We hypothesize that preeclampsia alters expression profiles of endothelial microRNAs (miRNAs) in fetal endothelial cells and disturbs the vascular endothelial growth factor A (VEGFA)- and fibroblast growth factor 2 (FGF2)-induced endothelial function.

DESIGN AND SETTING

Unpassaged (P0) human umbilical vein endothelial cells (HUVECs) were isolated immediately after cesarean-section delivery from normotensive (NT) and preeclamptic (PE) pregnancies. Differentially expressed miRNAs between P0-HUVECs from NT and PE pregnancies were identified using a miRNA polymerase chain reaction (PCR) array and confirmed using reverse transcription quantitative PCR. To determine the function of these differentially expressed miRNAs, miRNAs of interest were knocked down in NT-HUVECs following by cell functional assays.

RESULTS

Sixteen miRNAs, including miR-29a/c-3p, were downregulated in P0-HUVECs from the PE group compared with the NT group. Bioinformatics analysis predicted the PI3K-v-akt murine thymoma viral oncogene homolog 1 (AKT) signaling pathway was dysregulated in P0-HUVECs from the PE group, which was associated with the miR-29a/c-3p downregulation. We further demonstrated that miR-29a/c-3p knockdown inhibited the VEGFA- and FGF2-induced endothelial migration as well as FGF2-induced AKT1 phosphorylation in HUVECs. However, miR-29a/c-3p knockdown did not alter the extracellular signal-regulated kinase 1/2 phosphorylation, cell proliferation, and endothelial monolayer integrity in response to VEGFA and FGF2 in HUVECs.

CONCLUSIONS

Preeclampsia-downregulated miR-29a/c-3p may impair fetal endothelial function by disturbing the FGF2-activated PI3K-AKT signaling pathway, hence inhibiting endothelial cell migration.

The Role of miRNAs as Biomarkers for Pregnancy Outcomes: A Comprehensive Review

Several studies showed that altered expression of the miRNA-ome in maternal circulation or in placental tissue may reflect not only gestational disorders, such as preeclampsia, spontaneous abortion, preterm birth, low birth weight, or macrosomia, but also prenatal exposure to environmental pollutants. Generally, the relationships between environmental exposure, changes in miRNA expression, and gestational disorders are explored separately, producing conflicting findings. However, validation of tissue-accessible biomarkers for the monitoring of adverse pregnancy outcomes needs a systematic methodological approach that takes also into account early-life environmental exposure. To achieve this goal, exposure to xenochemicals, endogenous agents, and diet should be assessed. This study has the aim to provide a comprehensive review on the role of miRNAs as potential biomarkers for adverse pregnancy outcomes and prenatal environmental exposure.

miR-144 may regulate the proliferation, migration and invasion of trophoblastic cells through targeting PTEN in preeclampsia

Previous studies indicated that microRNAs (miRNAs) were aberrantly expressed in the placentas of patients with Preeclampsia (PE); however, the underlying mechanism still requires further investigation. The aim of this study is to investigate the roles of miR-144 in preeclampsia and the related mechanism. The expression of miR-144 and PTEN in 30 placentas of patients with PE and 30 normal placentas was compared; next, HTR8/SVneo cells were transfected with miR-144 mimics and miR-144 inhibitors and cultured for 48h, and the proliferation and apoptosis, cell migration and invasion of the cells were examined; furthermore, the expression PTEN, Caspase-3 and Bcl-2 was examined; next, dual luciferase reporter assay has been performed to confirm that PTEN is a direct target of miR-144; finally, HTR-8/SVneo cells were transfected with either PTEN overexpression plasmid or PTEN RNAi to determine whether knockdown or overexpression of PTEN can mimic the effect of miR-144 We have observed that the expression of miR-144 was significantly decreased and the expression of PTEN was markedly increased in placentas of patients with PE compared with normal placentas; moreover, transfection of miR-144 mimics in trophoblastic cells induced significant increase in cell proliferation, migration, invasion, and decrease in cell apoptosis, and also affected the cell cycles; on the other hand, transfection of miR-144 inhibitors has shown the opposite effects; furthermore, transient overexpression of miR-144 induced marked decrease in the expression of PTEN, Caspase-3 and increase in expression of Bcl-2 (P<0.01), while transfection of miR-144 inhibitors showed the opposite effects; finally, PTEN has been confirmed as a direct target of miR-144; finally, transfection of PTEN overexpression plasmid or PTEN RNAi can mimic the results of miR-144 inhibitor or miR-144 mimics, respectively. In conclusion, miR-144 was down-regulated in PE, and miR-144 may play important roles in the pathogenesis of PE through targeting PTEN in trophoblastic cells. These results suggested that miR-144 has the potential to become a therapeutic target for the treatment of PE.

Dysregulation of Placental miRNA in Maternal Obesity Is Associated With Pre- and Postnatal Growth

CONTEXT

Human placenta exhibits a specific microRNA (miRNA) expression pattern. Some of these miRNAs are dysregulated in pregnancy disorders such as preeclampsia and intrauterine growth restriction and are potential biomarkers for these pathologies.

OBJECTIVE

To study the placental miRNA profile in pregnant women with pregestational overweight/obesity (preOB) or gestational obesity (gestOB) and explore the associations between placental miRNAs dysregulated in maternal obesity and prenatal and postnatal growth.

METHODS

TaqMan Low Density Arrays and real-time polymerase chain reaction were used to profile the placental miRNAs in 70 pregnant women (20 preOB, 25 gestOB, and 25 control). Placentas and newborns were weighed at delivery, and infants were weighed at 1, 4, and 12 months of age.

RESULTS

Eight miRNAs were decreased in placentas from preOB or gestOB (miR-100, miR-1269, miR-1285, miR-181, miR-185, miR-214, miR-296, and miR-487) (all P < 0.05). Among them, miR-100, miR-1285, miR-296, and miR-487 were associated with maternal metabolic parameters (all P < 0.05) and were predictors of lower birth weight (all P < 0.05; R2 > 30%) and increased postnatal weight gain (all P < 0.05; R2 > 20%). In silico analysis showed that these miRNAs were related to cell proliferation and insulin signaling pathways. miR-296 was also present in plasma samples and associated with placental expression and prenatal and postnatal growth parameters (all P < 0.05).

CONCLUSIONS

We identified a specific placental miRNA profile in maternal obesity. Placental miRNAs dysregulated in maternal obesity may be involved in mediation of growth-promoting effects of maternal obesity on offspring and could be used as early markers of prenatal and postnatal growth.

Small Molecule, Big Prospects: MicroRNA in Pregnancy and Its Complications

MicroRNAs are small, noncoding RNA molecules that regulate target gene expression in the posttranscriptional level. Unlike siRNA, microRNAs are "fine-tuners" rather than "switches" in the regulation of gene expression; thus they play key roles in maintaining tissue homeostasis. The aberrant microRNA expression is implicated in the disease process. To date, numerous studies have demonstrated the regulatory roles of microRNAs in various pathophysiological conditions. In contrast, the study of microRNA in pregnancy and its associated complications, such as preeclampsia (PE), fetal growth restriction (FGR), and preterm labor, is a young field. Over the last decade, the knowledge of pregnancy-related microRNAs has increased and the molecular mechanisms by which microRNAs regulate pregnancy or its associated complications are emerging. In this review, we focus on the recent advances in the research of pregnancy-related microRNAs, especially their function in pregnancy-associated complications and the potential clinical applications. Here microRNAs that associate with pregnancy are classified as placenta-specific, placenta-associated, placenta-derived circulating, and uterine microRNA according to their localization and origin. MicroRNAs offer a great potential for developing diagnostic and therapeutic targets in pregnancy-related disorders.

Matrix Metalloproteinases in Normal Pregnancy and Preeclampsia

Normal pregnancy is associated with marked hemodynamic and uterine changes that allow adequate uteroplacental blood flow and uterine expansion for the growing fetus. These pregnancy-associated changes involve significant uteroplacental and vascular remodeling. Matrix metalloproteinases (MMPs) are important regulators of vascular and uterine remodeling. Increases in MMP-2 and MMP-9 have been implicated in vasodilation, placentation, and uterine expansion during normal pregnancy. The increases in MMPs could be induced by the increased production of estrogen and progesterone during pregnancy. MMP expression/activity may be altered during complications of pregnancy. Decreased vascular MMP-2 and MMP-9 may lead to decreased vasodilation, increased vasoconstriction, hypertensive pregnancy, and preeclampsia. Abnormal expression of uteroplacental integrins, cytokines, and MMPs may lead to decreased maternal tolerance, apoptosis of invasive trophoblast cells, inadequate remodeling of spiral arteries, and reduced uterine perfusion pressure (RUPP). RUPP may cause imbalance between the antiangiogenic factors soluble fms-like tyrosine kinase-1 and soluble endoglin and the proangiogenic vascular endothelial growth factor and placental growth factor, or stimulate the release of inflammatory cytokines, hypoxia-inducible factor, reactive oxygen species, and angiotensin AT1 receptor agonistic autoantibodies. These circulating factors could target MMPs in the extracellular matrix as well as endothelial and vascular smooth muscle cells, causing generalized vascular dysfunction, increased vasoconstriction and hypertension in pregnancy. MMP activity can also be altered by endogenous tissue inhibitors of metalloproteinases (TIMPs) and changes in the MMP/TIMP ratio. In addition to their vascular effects, decreases in expression/activity of MMP-2 and MMP-9 in the uterus could impede uterine growth and expansion and lead to premature labor. Understanding the role of MMPs in uteroplacental and vascular remodeling and function could help design new approaches for prediction and management of preeclampsia and premature labor.

Decreased homodimerization and increased TIMP-1 complexation of uteroplacental and uterine arterial matrix metalloproteinase-9 during hypertension-in-pregnancy

Preeclampsia is a complication of pregnancy manifested as hypertension-in-pregnancy (HTN-Preg) and often intrauterine growth restriction (IUGR). Placental ischemia could be an initiating event, but the molecular mechanisms are unclear. To test the hypothesis that dimerization of matrix metalloproteinases (MMPs) plays a role in HTN-Preg and IUGR, the levels/activity of MMP-9, tissue inhibitor of metalloproteinase (TIMP-1), and their dimerization forms were measured in the placenta, uterus, and uterine artery of normal pregnant (Preg) rats and a rat model of reduced uteroplacental perfusion pressure (RUPP). Consistent with our previous report, blood pressure (BP) was higher, pup weight was lower, and gelatin zymography showed different gelatinolytic activity for pro-MMP-9, MMP-9, pro-MMP-2 and MMP-2 in RUPP vs Preg rats. Careful examination of the zymograms showed additional bands at 200 and 135kDa. Western blots with MMP-9 antibody suggested that the 200kDa band was a MMP-9 homodimer. Western blots with TIMP-1 antibody as well as reverse zymography suggested that the 135kDa band was a MMP-9/TIMP-1 complex. The protein levels and gelatinase activity of MMP-9 homodimer were decreased while MMP-9/TIMP-1 complex was increased in placenta, uterus and uterine artery of RUPP vs Preg rats. The epidermal growth factor (EGF) receptor blocker erlotinib and protein kinase C (PKC) inhibitor bisindolylmaleimide decreased MMP-9 homodimer and increased MMP-9/TIMP-1 complex in placenta, uterus and uterine artery of Preg rats. EGF and the PKC activator phorbol-12,13-dibutyrate (PDBu) reversed the decreases in MMP-9 homodimer and the increases in MMP-9/TIMP-1 complex in tissues of RUPP rats. Thus, the increased BP and decreased pup weight in placental ischemia model of HTN-Preg are associated with a decrease in MMP-9 homodimer and an increase in MMP-9/TIMP-1 complex in placenta, uterus, and uterine artery, which together would cause a net decrease in MMP-9 activity and reduce uteroplacental and vascular remodeling in the setting of HTN-Preg and IUGR. Enhancing EGFR/PKC signaling may reverse the MMP-9 unfavorable dimerization patterns and thereby promote uteroplacental and vascular remodeling in preeclampsia.

Evaluation of circulating miRNAs during late pregnancy in the mare

MicroRNAs (miRNAs) are small, non-coding RNAs which are produced throughout the body. Individual tissues tend to have a specific expression profile and excrete many of these miRNAs into circulation. These circulating miRNAs may be diagnostically valuable biomarkers for assessing the presence of disease while minimizing invasive testing. In women, numerous circulating miRNAs have been identified which change significantly during pregnancy-related complications (e.g. chorioamnionitis, eclampsia, recurrent pregnancy loss); however, no prior work has been done in this area in the horse. To identify pregnancy-specific miRNAs, we collected serial whole blood samples in pregnant mares at 8, 9, 10 m of gestation and post-partum, as well as from non-pregnant (diestrous) mares. In total, we evaluated a panel of 178 miRNAs using qPCR, eventually identifying five miRNAs of interest. One miRNA (miR-374b) was differentially regulated through late gestation and four miRNAs (miR-454, miR-133b, miR-486-5p and miR-204b) were differentially regulated between the pregnant and non-pregnant samples. We were able to identify putative targets for the differentially regulated miRNAs using two separate target prediction programs, miRDB and Ingenuity Pathway Analysis. The targets for the miRNAs differentially regulated during pregnancy were predicted to be involved in signaling pathways such as the STAT3 pathway and PI3/AKT signaling pathway, as well as more endocrine-based pathways, including the GnRH, prolactin and insulin signaling pathways. In summary, this study provides novel information about the changes occurring in circulating miRNAs during normal pregnancy, as well as attempting to predict the biological effects induced by these miRNAs.

An exploratory study into the role of miR-204-5p in pregnancy-induced hypertension

The molecular mechanism that leads to pregnancy-induced hypertension (PIH), a pregnancy-specific syndrome, remains poorly understood. It has been suggested that microRNAs (miRNAs) may be potentially useful biomarkers for severe preeclampsia (PE), which is an important condition associated with PIH. The aim of the present study was to identify miR-204 by verifying differentially expressed serum miRNAs in patients with PIH during pregnancy compared with normal controls. Subsequently, the effects of miR-204 on proliferation and apoptosis of human choriocarcinoma (JAR) cells in hypoxic microenvironment were investigated. Previous studies indicated a number of miRNA candidates and the present study validated the expression of eight miRNAs in serum samples using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). A higher expression of miR-204 was identified in patients with PIH. To assess the impact of miR-204 inhibition on hypoxic JAR cells function in vitro, cell proliferation was detected using a Cell Counting Kit-8 assay. The rate of apoptosis and cell cycle progression was then examined by flow cytometry. RT-qPCR confirmed that serum miR-204-5p is more highly expressed in patients with PIH. Further statistical analysis indicated that the survival ratio of JAR cells in hypoxic microenvironments was increased in the miR-204-5p inhibitor group. However, the miR-204-5p inhibitor protected hypoxic JAR cells from apoptosis. The analysis of cell-cycle status demonstrated that the percentage of cells in the G2/G1 phase was larger compared with the control group. The results of the present study suggest that low levels of miR-204-5p may increase cell proliferation and reduce cell apoptosis with cell cycle changes in vitro. Therefore, serum miR-204-5p may be used as a notable biomarker for the diagnosis, prevention and treatment of PIH.

Provocative ideas on human placental biology: A prerequisite for prevention and treatment of neonatal health challenges

A 2-day invite-only meeting on generating "Provocative Ideas on human placental research" was organized on 1-2 December 2015 at the Translational Health Science and Technology Institute, Faridabad. This meeting was sponsored by Department of Biotechnology, Ministry of Science and Technology, Govt. of India. The objectives of this meeting were the critical evaluation of placental physiology and its development. Special emphasis was placed on understanding the consequences and implications of placental development in sustenance of pregnancy and in pregnancy-associated complications such as preeclampsia, intrauterine growth restriction, and preterm birth. This meeting brought together experienced as well as novice clinicians and biologists who have a keen interest in the field of placental biology, including development of new technologies and methods for evaluating the role of placenta in predicting pregnancy outcomes. The meeting primarily focused on (i) high-throughput "-omics" approaches, (ii) maternal nutrition and placental function, (iii) placental infection and inflammation, (iv) real-time evaluation of placental development: tools for placental research, and (v) epidemiologic relevance of placental-based research. Unanimous consensus emerged among the participants to carry out additional work focused on these areas. In this article, we summarize the talks and review the published literature on the above-mentioned niches. As a direct outcome of this meeting, a request for applications has been announced by the Department of Biotechnology, Government of India, for pursuing research in this vital but understudied domain.

Lower expressed miR-198 and its potential targets in hepatocellular carcinoma: a clinicopathological and in silico study

Purpose

To investigate the clinicopathological value and potential roles of microRNA-198 (miR-198) in hepatocellular carcinoma (HCC).

Methods

Ninety-five formalin-fixed paraffin-embedded HCC and the para-cancerous liver tissues were gathered. Real-time reverse transcription quantitative polymerase chain reaction was applied to determine the miR-198 expression. The association between the miR-198 expression and clinicopathological features was examined. Meanwhile, potential target messenger RNAs of miR-198 in HCC were obtained from 14 miRNA prediction databases and natural language processing method, in which we pooled the genes related to the tumorigenesis and progression of HCC and classified them by their frequency. The selected target genes were finally analyzed in the Gene Ontology analysis and Kyoto Encyclopedia of Genes and Genomes pathway.

Results

miR-198 expression was significantly lower in HCC than that in adjacent noncancerous liver tissues (1.30±0.72 vs 2.01±0.58, P<0.001). Low miR-198 expression was also correlated to hepatitis C virus infection (r=−0.48, P<0.001), tumor capsular infiltration (r=−0.43, P<0.001), metastasis (r=−0.26, P<0.010), number of tumor nodes (r=−0.25, P=0.013), vaso-invasion (r=−0.24, P=0.017), and clinical tumor node metastasis stage (r=−0.23, P=0.024). Altogether, 1,048 genes were achieved by the concurrent prediction from at least four databases and natural language processing indicated 1,800 genes for HCC. Further, 127 overlapping targets were further proceeded with for pathway analysis. The most enriched Gene Ontology terms in the potential target messenger RNAs of miR-198 were cell motion, cell migration, cell motility, and regulation of cell proliferation in biological process; organelle lumen, membrane-enclosed lumen, and nuclear lumen in cellular component; and enzyme binding, protein domain-specific binding, and protein kinase activity in molecular function. Kyoto Encyclopedia of Genes and Genomes analysis showed that these target genes were obviously involved in focal adhesion and pathways in cancer.

Conclusion

Lower expression of miR-198 was related to several clinicopathological parameters in HCC patients. miR-198 might play a regulatory role through its target genes in the development of HCC.

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.

miR-197: A novel biomarker for cancers

microRNAs (miRNAs) are small noncoding RNAs that could regulate post-transcription level through binding to 3' untranslated region (3'UTR) of target messenger RNAs (mRNAs), which were reported to be related with the incidence and development of diverse neoplasms. Among them, miR-197 was confirmed to play a vital role of oncogene or anti-oncogene in different cancers via targeting key tumorigenic or tumor-suppressive genes. Additionally, miR-197 had extensively been studied in carcinogenesis progression of cancers through various mechanisms, including apoptosis, proliferation, angiogenesis, metastasis, drug resistance and tumor suppressor, and also played a role in prognosis of cancers. In this review, we summarized the roles of miR-197 in cancers and considered it as a potentially novel biomarker for different cancers, offering an alternatively secure and effective tool in molecular targeting cancer treatment.

Mechanisms of Endothelial Dysfunction in Hypertensive Pregnancy and Preeclampsia

Preeclampsia is a pregnancy-related disorder characterized by hypertension and could lead to maternal and fetal morbidity and mortality. Although the causative factors and pathophysiological mechanisms are unclear, endothelial dysfunction is a major hallmark of preeclampsia. Clinical tests and experimental research have suggested that generalized endotheliosis in the systemic, renal, cerebral, and hepatic circulation could decrease endothelium-derived vasodilators such as nitric oxide, prostacyclin, and hyperpolarization factor and increase vasoconstrictors such as endothelin-1 and thromboxane A2, leading to increased vasoconstriction, hypertension, and other manifestation of preeclampsia. In search for the upstream mechanisms that could cause endothelial dysfunction, certain genetic, demographic, and environmental risk factors have been suggested to cause abnormal expression of uteroplacental integrins, cytokines, and matrix metalloproteinases, leading to decreased maternal tolerance, apoptosis of invasive trophoblast cells, inadequate spiral arteries remodeling, reduced uterine perfusion pressure (RUPP), and placental ischemia/hypoxia. RUPP may cause imbalance between the antiangiogenic factors soluble fms-like tyrosine kinase-1 and soluble endoglin and the proangiogenic factors vascular endothelial growth factor and placental growth factor, or stimulate the release of other circulating bioactive factors such as inflammatory cytokines, hypoxia-inducible factor-1, reactive oxygen species, and angiotensin AT1 receptor agonistic autoantibodies. These circulating factors could then target endothelial cells and cause generalized endothelial dysfunction. Therapeutic options are currently limited, but understanding the factors involved in endothelial dysfunction could help design new approaches for prediction and management of preeclampsia.