miR-15b-AGO2 play a critical role in HTR8/SVneo invasion and in a model of angiogenesis defects related to inflammation

A systematic review and risk of bias analysis of in vitro studies on trophoblast response to immunological triggers

An increasing amount of evidence suggests that immune responses may affect trophoblast functioning, which in turn may play a role in gestational disorders and fetal development. This systematic review offers the first summary of in vitro studies on the trophoblast response to immunological triggers, in conjunction with a risk of bias analysis. A search in Pubmed and Embase yielded 110 relevant studies. Primary trophoblasts were the most commonly used cell type, but trophoblast subtypes were not always defined. Similarly, the exact natures of trophoblast cell lines were sometimes unclear. Cytokines and Toll-like receptor agonists were often used as interventions, but most studies focused on a select few substances such as tumor necrosis factor-α and lipopolysaccharide. In regard to the outcome parameters, some important trophoblast functions, such as hormone production and barrier formation were underrepresented. Whether or not risk of bias was high varied strongly between types of bias. Risk of selection bias, for example, was usually low. However, none of the included studies mentioned blinding or plate randomization. Only a select few studies mentioned passage numbers, use of vehicle control or conflict of interest. In conclusion, better characterization of trophoblast subtypes and a broader range of studied interventions and outcome parameters would contribute to a more complete understanding of trophoblast responses to immune stimuli. Additionally, researchers are encouraged to replicate experiments and pay close attention when setting up and writing down methodologies, in order to improve the reproducibility and translatability of their work.

Dysregulation of miRNA-mRNA expression in fetal growth restriction in a caloric restricted mouse model

Fetal growth restriction (FGR) is associated with aberrant placentation and accounts for a significant proportion of perinatal deaths. microRNAs have been shown to be dysregulated in FGR. The purpose of this study was to determine microRNA-regulated molecular pathways altered using a caloric restricted mouse model of FGR. Pregnant mice were subjected to a 50% caloric restricted diet beginning at E9. At E18.5, RNA sequencing of placental tissue was performed to identify differences in gene expression between caloric restricted and control placentas. Significant differences in gene expression between caloric restricted and control placentas were observed in 228 of the 1546 (14.7%) microRNAs. Functional analysis of microRNA-mRNA interactions demonstrated enrichment of several biological pathways with oxidative stress, apoptosis, and autophagy pathways upregulated and angiogenesis and signal transduction pathways downregulated. Ingenuity pathway analysis also suggested that ID1 signaling, a pathway integral for trophoblast differentiation, is also dysregulated in caloric restricted placentas. Thus, a maternal caloric restriction mouse model of FGR results in aberrant microRNA-regulated molecular pathways associated with angiogenesis, oxidative stress, signal transduction, apoptosis, and cell differentiation. As several of these pathways are dysregulated in human FGR, our findings suggest that this model may provide an excellent means to study placental microRNA derangements seen in FGR.

Upregulation of miR-184 and miR-19a-3p induces endothelial dysfunction by targeting AGO2 in Kawasaki disease

BACKGROUND

Endothelial dysfunction is a marked feature of Kawasaki disease during convalescence, but its pathogenesis is currently unclear. Circulating microRNAs (miRNAs) are associated with the progression of Kawasaki disease. However, the role and mechanism of circulating miRNAs in endothelial dysfunction are largely unknown. Kawasaki disease patients were found to have a unique circulating miRNA profile, including upregulation of miRNA-210-3p, miR-184 and miR-19a-3p, compared to non-Kawasaki disease febrile controls. This study aimed to investigate the effects of these three miRNAs on endothelial function.

METHODS

Overexpression of miRNAs in human umbilical vein endothelial cells was done by transfection of miRNA mimics. The tube formation assay was used to evaluate the function of human umbilical vein endothelial cells. The potential binding sites of miRNAs on 3'untranslated regions were predicted by using TargetScan database and validated by dual luciferase reporter assay. The protein expression of AGO2, PTEN and VEGF in human umbilical vein endothelial cells was detected by Western blot. Overexpression of AGO2 in human umbilical vein endothelial cells was done by transfection of AGO2 expression plasmids.

RESULTS

Overexpression of miRNA-184 and miRNA-19a-3p, but not miR-210-3p, impaired the function of human umbilical vein endothelial cells. Mechanistically, miR-184 and miR-19a-3p could target the 3'untranslated regions of AGO2 mRNA to downregulate its expression and subsequently impede the AGO2/PTEN/VEGF axis. To be noted, the rescue of the expression of AGO2 remarkably recovered the function that was impaired by overexpression of miRNA-184 and miRNA-19a-3p.

CONCLUSIONS

This study suggested that miR-184 and miR-19a-3p could target AGO2/PTEN/VEGF axis to induce endothelial dysfunction in Kawasaki disease.

MiR-15b-5p and PCSK9 inhibition reduces lipopolysaccharide-induced endothelial dysfunction by targeting SIRT4

BACKGROUND

Endothelial dysfunction and deregulated microRNAs (miRNAs) participate in the development of sepsis and are associated with septic organ failure and death. Here, we explored the role of miR-15b-5p on inflammatory pathways in lipopolysaccharide (LPS)-treated human endothelial cells, HUVEC and TeloHAEC.

METHODS

The miR-15b-5p levels were evaluated in LPS-stimulated HUVEC and TeloHAEC cells by quantitative real-time PCR (qRT-PCR). Functional experiments using cell counting kit-8 (CCK-8), transfection with antagomir, and enzyme-linked immunosorbent assays (ELISA) were conducted, along with investigation of pyroptosis, apoptosis, autophagy, and mitochondrial reactive oxygen species (ROS) by cytofluorometric analysis and verified by fluorescence microscopy. Sirtuin 4 (SIRT4) levels were detected by ELISA and immunoblotting, while proprotein convertase subtilisin-kexin type 9 (PCSK9) expression was determined by flow cytometry (FACS) and immunofluorescence analyses. Dual-luciferase reporter evaluation was performed to confirm the miR-15b-5p-SIRT4 interaction.

RESULTS

The results showed a correlation among miR-15b-5p, PCSK9, and SIRT4 levels in septic HUVEC and TeloHAEC. Inhibition of miR-15b-5p upregulated SIRT4 content, alleviated sepsis-related inflammatory pathways, attenuated mitochondrial stress, and prevented apoptosis, pyroptosis, and autophagic mechanisms. Finally, a PCSK9 inhibitor (i-PCSK9) was used to analyze the involvement of PCSK9 in septic endothelial injury. i-PCSK9 treatment increased SIRT4 protein levels, opposed the septic inflammatory cascade leading to pyroptosis and autophagy, and strengthened the protective role of miR-15b-5p inhibition. Increased luciferase signal validated the miR-15b-5p-SIRT4 binding.

CONCLUSIONS

Our in vitro findings suggested the miR-15b-5p-SIRT4 axis as a suitable target for LPS-induced inflammatory pathways occurring in sepsis, and provide additional knowledge on the beneficial effect of i-PCSK9 in preventing vascular damage by targeting SIRT4.

HIF1 inhibitor acriflavine rescues early-onset preeclampsia phenotype in mice lacking placental prolyl hydroxylase domain protein 2

Preeclampsia is a serious pregnancy disorder that lacks effective treatments other than delivery. Improper sensing of oxygen changes during placentation by prolyl hydroxylases (PHDs), specifically PHD2, causes placental hypoxia-inducible factor-1 (HIF1) buildup and abnormal downstream signaling in early-onset preeclampsia, yet therapeutic targeting of HIF1 has never been attempted. Here we generated a conditional (placenta-specific) knockout of Phd2 in mice (Phd2-/- cKO) to reproduce HIF1 excess and to assess anti-HIF therapy. Conditional deletion of Phd2 in the junctional zone during pregnancy increased placental HIF1 content, resulting in abnormal placentation, impaired remodeling of the uterine spiral arteries, and fetal growth restriction. Pregnant dams developed new-onset hypertension at midgestation (E9.5) in addition to proteinuria and renal and cardiac pathology, hallmarks of severe preeclampsia in humans. Daily injection of acriflavine, a small molecule inhibitor of HIF1, to pregnant Phd2-/- cKO mice from E7.5 (prior to hypertension) or E10.5 (after hypertension had been established) to E14.5 corrected placental dysmorphologies and improved fetal growth. Moreover, it reduced maternal blood pressure and reverted renal and myocardial pathology. Thus, therapeutic targeting of the HIF pathway may improve placental development and function, as well as maternal and fetal health, in preeclampsia.

The role of miRNA-210 in pre-eclampsia development

MicroRNAs (miRNAs) are a class of small non-coding, single-stranded RNAs (ribonucleic acids) that play important roles in many vital processes through their impact on gene expression. One such miRNA, miR210, represents a hypoxia-induced cellular miRNA group that hold a variety of functions. This review article highlights the importance of miR-210 in the development of pre-eclampsia.KEY MESSAGEmiR-210 is a promising biomarker for monitoring pregnancy with pre-eclampsia. Overexpression of miR-210 had a negative impact on the process of cell migration and trophoblast invasion.

Expression Analysis of Moritella viscosa-Challenged Atlantic Salmon Identifies Disease-Responding Genes, MicroRNAs and Their Predicted Target Genes and Pathways

Moritella viscosa is a bacterial pathogen causing winter-ulcer disease in Atlantic salmon. The lesions on affected fish lead to increased mortality, decreased fish welfare, and inferior meat quality in farmed salmon. MicroRNAs (miRNAs) are small non-coding RNAs involved in post-transcriptional regulation by guiding the miRNA-induced silencing complex to specific mRNA transcripts (target genes). The goal of this study was to identify miRNAs responding to Moritella viscosa in salmon by investigating miRNA expression in the head-kidney and the muscle/skin from lesion sites caused by the pathogen. Protein coding gene expression was investigated by microarray analysis in the same materials. Seventeen differentially expressed guide-miRNAs (gDE-miRNAs) were identified in the head-kidney, and thirty-nine in lesion sites, while the microarray analysis reproduced the differential expression signature of several thousand genes known as infection-responsive. In silico target prediction and enrichment analysis suggested that the gDE-miRNAs were predicted to target genes involved in immune responses, hemostasis, angiogenesis, stress responses, metabolism, cell growth, and apoptosis. The majority of the conserved gDE-miRNAs (e.g., miR-125, miR-132, miR-146, miR-152, miR-155, miR-223 and miR-2188) are known as infection-responsive in other vertebrates. Collectively, the findings indicate that gDE-miRNAs are important post-transcriptional gene regulators of the host response to bacterial infection.

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

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

The Role of Non-Coding RNAs in the Human Placenta

Non-coding RNAs (ncRNAs) play a central and regulatory role in almost all cells, organs, and species, which has been broadly recognized since the human ENCODE project and several other genome projects. Nevertheless, a small fraction of ncRNAs have been identified, and in the placenta they have been investigated very marginally. To date, most examples of ncRNAs which have been identified to be specific for fetal tissues, including placenta, are members of the group of microRNAs (miRNAs). Due to their quantity, it can be expected that the fairly larger group of other ncRNAs exerts far stronger effects than miRNAs. The syncytiotrophoblast of fetal origin forms the interface between fetus and mother, and releases permanently extracellular vesicles (EVs) into the maternal circulation which contain fetal proteins and RNA, including ncRNA, for communication with neighboring and distant maternal cells. Disorders of ncRNA in placental tissue, especially in trophoblast cells, and in EVs seem to be involved in pregnancy disorders, potentially as a cause or consequence. This review summarizes the current knowledge on placental ncRNA, their transport in EVs, and their involvement and pregnancy pathologies, as well as their potential for novel diagnostic tools.

Single Cell Proteomics Profiling Reveals That Embryo-Secreted TNF-α Plays a Critical Role During Embryo Implantation to the Endometrium

It has been long-known that endometrium-secreted cytokines play a critical role during embryo implantation. However, whether cytokines secreted from the embryo are relevant to the process of embryo implantation remains unclear. The concentration of cytokines in embryo culture medium was tested using a newly developed, high-sensitivity single-cell proteomic platform and evaluated in comparison to embryo quality and clinical outcome. The effect of TNF-α on embryo and endometrium Ishikawa cells was investigated using immunofluorescence staining, CCK-8 assay, TUNEL staining, and RT-qPCR. Of the 10 cytokines measured, only TNF-α concentration was significantly higher in the group with embryo implantation failure. Immunofluorescence staining showed that the expression of TNF-α was unevenly distributed in blastocysts, and the expression level was significantly correlated with the blastocyst inner cell mass (ICM) quality score. Gene profiling showed that addition of TNF-α led to increased expression of tumor necrosis factor receptor 1 (TNFR1) and apoptosis-related genes and that this could be inhibited by the TNF-α receptor inhibitor etanercept (ETA). In addition, an increased expression of water and ion channels, including AQP3, CFTR, ENaCA, and CRISP2 was also observed which could also be inhibited by ETA. Our results show that higher embryo-secreted TNF-α levels are associated with implantation failure through activation of TNF-α receptor, and TNF-α may be an independent predictor for pre-transfer assessment of the embryo development potential in IVF patients.

MicroRNAs and Heat Shock Proteins in Breast Cancer Biology

Breast cancer has five major immune types; luminal A, luminal B, HER2, Basal-like, and normal-like. Cells produce a family of protein called heat shock proteins (Hsps) in response to exposure to thermal and other proteotoxic stresses play essential roles in cancer metabolism and this large family shows a diverse set of Hsp involvement in different breast cancer immune types. Recently, Hsp members categorized according to their immune type roles. Hsp family consists of several subtypes formed by molecular weight; Hsp70, Hsp90, Hsp100, Hsp40, Hsp60, and small molecule Hsps. Cancer cells employ Hsps as survival factors since most of these proteins prevent apoptosis. Several studies monitored Hsp roles in breast cancer cells and reported Hsp27 involvement in drug resistance, Hsp70 in tumor cell transformation-progression, and interaction with p53. Furthermore, the association of Hsp90 with steroid receptors and signaling proteins in patients with breast cancer directed research to focus on Hsp-based treatments. miRNAs are known to play key roles in all types of cancer that are upregulated or downregulated in cancer which respectively referred to as oncogenes (oncomirs) or tumor suppressors. Expression profiles of miRNAs may be used to classify, diagnose, and predict different cancer types. It is clear that miRNAs play regulatory roles in gene expression and this work reveals miRNA correlation to Hsp depending on specific breast cancer immune types. Deregulation of specific Hsp genes in breast cancer subtypes allows for identification of new targets for drug design and cancer treatment. Here, we performed miRNA network analysis by recruiting Hsp genes detected in breast cancer subtypes and reviewed some of the miRNAs related to aforementioned Hsp genes.

Role of GRK2 in Trophoblast Necroptosis and Spiral Artery Remodeling: Implications for Preeclampsia Pathogenesis

Impaired invasion of extravillous trophoblasts and severe oxidative stress manifest the poor placentation in preeclampsia, which is life-threatening and more than a hypertensive disease of pregnancy. Previous studies have reported that G protein-coupled receptor kinases (GRKs) play a key role in initiating hypertension and hypertensive renal damage, yet little evidence so far suggests a link between GRKs and preeclampsia-related hypertension. Here, we demonstrate GRK2 expression is significantly downregulated (P < 0.0001) in preeclamptic placentae compared to normotensive controls. Knockdown or inhibition of GRK2 in placentae caused insufficient arterial remodeling and elevated trophoblast necroptosis in vivo. These further induced preeclampsia-like phenotype in mice: hypertension, proteinuria, and elevated pro-angiogenic cytokines. By human extra-villous invasive trophoblast cell line (HTR8/SVneo cells), we revealed the knockdown or inhibition of GRK2 triggered excessive death with typical necroptotic characteristics: nuclear envelope rupture and the activation of RIPK1, RIPK3, and MLKL. Necrostatin-1, an inhibitor of RIPK1, is able to restore the survival of trophoblasts. Together, our findings demonstrated that insufficient GRK2 activity compromises spiral artery remodeling and initiates necrotic events in placentae, thereby leading to preeclampsia. These findings advance our understanding of GRK2 in the pathogenesis of preeclampsia and could shed light on a potential treatment for preeclampsia.

Modeling human peri-implantation placental development and function†

It is very difficult to gain a better understanding of the events in human pregnancy that occur during and just after implantation because such pregnancies are not yet clinically detectable. Animal models of human placentation are inadequate. In vitro models that utilize immortalized cell lines and cells derived from trophoblast cancers have multiple limitations. Primary cell and tissue cultures often have limited lifespans and cannot be obtained from the peri-implantation period. We present here two contemporary models of human peri-implantation placental development: extended blastocyst culture and stem-cell derived trophoblast culture. We discuss current research efforts that employ these models and how such models might be used in the future to study the "black box" stage of human pregnancy.

Diagnostic Potential of MicroRNAs as Biomarkers in the Detection of Preeclampsia

Preeclampsia is a multisystemic disorder that occurs in 5-8% of pregnant women and remains a leading cause of both maternal and fetal morbidity and mortality. The disease is characterized by the abnormal vascular response to placentation, but the exact pathophysiology and pathogenesis of preeclampsia remain unknown. Risk factors for preeclampsia include increased maternal age, obesity, multiple gestations, and a history of preeclampsia. Several studies have suggested that altered expression of some microRNAs (miRNAs) in placental tissue, and maternal circulation, may be associated with several types of pregnancy complications such as preeclampsia, preterm birth, and spontaneous abortion. It is assumed that these miRNAs play an important role in various cellular processes important for maintaining a healthy pregnancy, including promoting angiogenesis and the differentiation of trophoblast cells. In this review, we discuss the role of miRNAs as potential biomarkers of preeclampsia.

Pre-eclampsia predictive ability of maternal miR-125b: a clinical and experimental study

Pre-eclampsia (PE) is a systemic maternal syndrome affecting 2-8% of pregnancies worldwide and involving poor placental perfusion and impaired blood supply to the foetus. It manifests after the 20th week of pregnancy as new-onset hypertension and substantial proteinuria and is responsible for severe maternal and newborn morbidity and mortality. Identifying biomarkers that predict PE onset prior to its establishment would critically help treatment and attenuate outcome severity. MicroRNAs are ubiquitous gene expression modulators found in blood and tissues. Trophoblast cell surface antigen (Trop)-2 promotes cell growth and is involved in several cancers. We assessed the PE predictive ability of maternal miR-125b in the first trimester of pregnancy by measuring its plasma levels in women with normal pregnancies and with pregnancies complicated by PE on the 12th week of gestation. To gain insight into PE pathogenesis we investigated whether Trop-2 is targeted by miR-125b in placental tissue. Data analysis demonstrated a significant association between plasma miR-125b levels and PE, which together with maternal body mass index before pregnancy provided a predictive model with an area under the curve of 0.85 (95% confidence interval, 0.70-1.00). We also found that Trop-2 is a target of miR-125b in placental cells; its localization in the basal part of the syncytiotrophoblast plasma membrane suggests a role for it in the early onset of PE. Altogether, maternal miR-125b proved a promising early biomarker of PE, suggesting that it may be involved in placental development through its action on Trop-2 well before the clinical manifestations of PE.

Platelet-derived microparticles from recurrent miscarriage associated with antiphospholipid antibody syndrome influence behaviours of trophoblast and endothelial cells

Platelet-derived microparticles (PMPs) are a type of microparticle budding from platelets undergoing activation or apoptosis in many autoimmune diseases, including antiphospholipid antibody syndrome (APS). PMPs may also contribute to recurrent miscarriage, although the exact mechanism is unclear. The aim of this study was to determine the potential biological mechanism by which abnormal PMP activation may affect recurrent miscarriage. PMPs were counted by fluorescence-activated cell sorting (FACS) and compared between the healthy control (HC) and recurrent miscarriage/APS groups. Different effects of PMPs isolated by FACS from patients with recurrent miscarriage/APS and HCs were explored. Capillary electrophoresis immunoquantification, RT-qPCR, Luminex xMAP and immunofluorescence staining were performed to investigate all these different effects of PMPs. We found that the difference in the counts of PMP was not significant. However the expression of the inflammatory cytokine tumour necrosis factor-α (TNF-α) and the adhesion molecules intracellular cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) were increased by PMPs derived from the recurrent miscarriage/APS group. PMPs isolated from patients with recurrent miscarriage/APS also more potently stimulated monocyte recruitment, inhibited angiogenesis and promoted human umbilical vein endothelial cell (HUVEC) apoptosis, in comparison to PMPs from HCs matched for gestational week. Moreover, PMPs could be ternalized by HTR-8/SVneo cells and could increase apoptosis of these cells and decrease trophoblastic invasion and migration. To supplement our work, the limited sample size needs to be increased, and further in-vivo work is necessary. Findings from this study indicate that abnormal activation of PMPs contributes to recurrent miscarriage/APS progression and provides potential therapeutic targets.

Micro-RNAs in the aqueous humour of patients with diabetic macular oedema

IMPORTANCE

Micro-RNAs (miRNAs) have been studied as new biomarkers or mediators in various diseases, but the value of aqueous humour (AH) miRNAs in diabetic macular oedema (DMO) is still not known.

BACKGROUND

To compare AH miRNAs and related cytokine expression in DMO patients and healthy controls.

DESIGN

Prospective cross-sectional study.

PARTICIPANTS

Twenty naïve DMO patients and 13 control subjects, who were scheduled for intravitreal injection and cataract surgery, respectively.

METHODS

AH samples were collected at the beginning of each procedure and analysed using a miRNA polymerase chain reaction (PCR) array composed of 84 miRNAs, reverse transcripase-quantitative PCR (qPCR) for verifying selected differentially expressed miRNAs, and a cytokine assay, the results of which were compared with bioinformatics conducted to find out genes associated with DMO-related miRNAs.

MAIN OUTCOMES MEASURES

AH expression of miRNAs and cytokines and the bioinformatics results.

RESULTS

Five miRNAs (hsa-miR-185-5p, hsa-miR-17-5p, hsa-miR-20a-5p, hsa-miR-15b-5p and hsa-miR-15a-5p) showing a fold change greater than -50 in log2 values in the miRNA PCR array were selected, all significantly down-regulated in the DMO group compared to the control group (P < .05), and showed a direct relationship with tumour necrosis factor, nuclear factor kappa B subunit 1 and interleukin-6 (IL-6) in bioinformatics analysis, all of which were related to vascular endothelial growth factor (VEGF). In the cytokine assay, the aqueous concentrations of VEGF, placental growth factor, IL-6 and IL-8 were significantly higher in the DMO group compared to the control group.

CONCLUSIONS AND RELEVANCE

This study is the first to perform miRNA profiling of the AH of DMO patients. We identified differentially expressed miRNAs in DMO AH, which may be used as potential biomarkers or novel therapeutic targets for DMO.

HHV-6A Infection of Endometrial Epithelial Cells Affects miRNA Expression and Trophoblast Cell Attachment

We recently reported that human herpesvirus 6 (HHV-6) infection is frequently present in endometrial tissue of women with unexplained infertility, and that virus infection induces a profound remodulation of miRNA expression in human cells of different origin. Since specific miRNA patterns have been associated with specific pregnancy outcomes, we aimed to analyze the impact of HHV-6A infection on miRNAs expression and trophoblast receptivity in human endometrial cells. To this purpose, a human endometrial cell line (HEC-1A) was infected with HHV-6A and analyzed for alterations in the expression of miRNAs and for permissiveness to the attachment of a human choriocarcinoma trophoblast cell line (JEG-3). The results showed that HHV-6A infection of endometrial cells up-modulates miR22 (26-fold), miR15 (19.5-fold), and miR196-5p (12.1 fold), that are correlated with implant failure, and down-modulates miR18 (11.4 fold), miR101-3p (4.6 fold), miR181-5p (4.9 fold), miR92 (3.3 fold), and miR1207-5p (3.9 fold), characterized by a low expression in preeclampsia. Moreover, HHV-6A-infected endometrial cells infected resulted less permissive to the attachment of trophoblast cells. In conclusion, collected data suggest that HHV-6A infection could modify miRNA expression pattern and control of trophoblast cell adhesion of endometrial cells, undermining a correct trophoblast cell attachment on endometrial cells.

The association of AGO1 (rs595961G>A, rs636832A>G) and AGO2 (rs11996715C>A, rs2292779C>G, rs4961280C>A) polymorphisms and risk of recurrent implantation failure

Recurrent implantation failure (RIF) is a common reproductive clinical condition treated by fertility specialists at in vitro fertilization (IVF) clinics. Several factors affect embryo implantation including the age of the female, the quality of embryos and the sperm, genetics, immunologic factors. Here, we investigated the association of Argonaute 1 (AGO1) and Argonaute 2 (AGO2) polymorphisms and RIF. We collected blood samples from 167 patients with RIF and 211 controls. Genetic polymorphisms were detected by polymerase chain reaction (PCR) – restriction fragment length polymorphism analysis and real-time PCR. We found that the AGO2 rs4961280C>A polymorphism (adjusted odds ratio [AOR] = 1.984; P = 0.023) was significantly associated with RIF. Furthermore, in RIF patients with three or more consecutive implantation failure, the AGO2 rs4961280C>A CA genotype (AOR = 2.133; P = 0.013) and dominant model (AOR = 2.272; P = 0.006) were both significantly associated with prevalence of RIF. An analysis of variance revealed that patients with the AGO2 rs2292779C>G genotypes (CC: 6.52 ± 2.55; CG: 7.46 ± 3.02; GG: 8.42 ± 2.74; P = 0.044) and the dominant model (CC: 6.52 ± 2.55; CG+GG: 7.70 ± 2.97; P = 0.029) exhibited significantly increased white blood cell levels. Furthermore, patients with the AGO1 rs595961G>A dominant model (GG: 36.81 ± 8.69; GA+AA: 31.58 ± 9.17; P = 0.006) and the AGO2 rs4961280C>A recessive model (CC+CA: 35.42 ± 8.77; AA: 22.00 ± 4.24; P = 0.035) exhibited a significantly decreased number of CD4⁺ helper T cells. Our study showed that AGO1 and AGO2 polymorphisms are associated with the prevalence of RIF. Hence, the results suggest that variations in AGO1 and AGO2 genotypes may be useful clinical biomarkers for the development and prognosis of RIF.

Significant Role of Dicer and miR-223 in Adipose Tissue of Polycystic Ovary Syndrome Patients

Polycystic ovary syndrome (PCOS) is a chronic metabolic disease that is associated with obesity and adipose tissue dysfunction. This study aimed to explore the roles of Dicer (an enzyme that processes primary microRNAs) and microRNAs in PCOS. Protein levels were detected by western blotting, and mRNA and microRNA levels were detected by RT-PCR. Dicer-deficient pre-adipocytes were established by lentiviral transfection, and an miR-223 mimic and miR-223 inhibitor were used to overexpress and inhibit miR-223, respectively. 3T3-L1 cells were induced to differentiate into mature adipocytes by IBMX, insulin, and dexamethasone. The degree of differentiation was determined by oil red O staining. An insulin resistance model was established by exposing mature adipocytes to excessive glucose and insulin. The protein levels of Dicer and Ago2 in adipose tissues of PCOS patients were significantly lower than those in control females. A Dicer-deficient 3T3-L1 cell model was successfully established, whose proliferation was inhibited significantly. Insulin-resistant mature adipocytes expressed significantly less Dicer protein than control cells. The differentiation of Dicer-deficient 3T3-L1 cells and their expression of miR-223 and marker genes associated with adipose differentiation were reduced significantly. Furthermore, 3T3-L1 cells showed a weaker ability to develop into mature adipocytes when miR-223 expression was inhibited. An miR-223 mimic was used to recover the differentiation block induced by Dicer deficiency. This rescued the expression of genes associated with adipose differentiation, although the differentiation block was not efficiently rescued. It is concluded that insulin resistance may contribute to the decreased levels of Dicer protein in adipose tissue of PCOS patients. This suggests that dysfunction of Dicer plays a significant role in obesity of PCOS patients. miR-223 is a key factor in Dicer-regulated adipose differentiation, and other microRNAs may be involved in the process.

Association study of AGO1 and AGO2 genes polymorphisms with recurrent pregnancy loss

An Argonaute (AGO) protein within the RNA-induced silencing complex binds a microRNA, permitting the target mRNA to be silenced. We hypothesized that variations in AGO genes had the possibility including affected the miRNA function and associated with recurrent pregnancy loss (RPL) susceptibility. Especially, we were chosen the AGO1 (rs595961, rs636832) and AGO2 (rs2292779, rs4961280) polymorphisms because of those polymorphisms have already reported in other diseases excluding the RPL. Here, we conducted a case-control study (385 RPL patients and 246 controls) to evaluate the association of four polymorphisms with RPL. We found that the AGO1 rs595961 AA genotype, recessive model (P = 0.039; P = 0.043, respectively), the AGO1 rs636832 GG genotype, and recessive model (P = 0.037; P = 0.016, respectively) were associated with RPL in women who had had four or more consecutive pregnancy losses. The patients with the AGO1 rs636832 GG genotypes had greater platelet counts (P = 0.023), while the patients with the AGO2 rs4961280 CA genotypes had less homocysteine (P = 0.027). Based on these results, we propose that genetic variations with respect to the AGO1 and AGO2 genotypes are associated with risk for RPL, and might serve as useful biomarkers for the prognosis of RPL.

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.

Long noncoding RNA MIAT2 alleviates lipopolysaccharide-induced inflammatory damage in WI-38 cells by sponging microRNA-15

Neonatal pneumonia is a high neonatal mortality disease. We studied the function and mechanism of long noncoding RNA myocardial infarction-associated transcript 2 (lncRNA MIAT2) on lipopolysaccharide (LPS)-induced inflammation in WI-38 cells. Cell Counting Kit-8 and apoptosis assay were respectively used to detect the functions of LPS, MIAT2, and microRNA-15 (miR-15) on viability and apoptosis. MIAT2 and miR-15 expressions were changed by cell transfection. Moreover, reverse transcription-quantitative polymerase chain reaction (RT-qPCR), western blot, and enzyme-linked immunosorbent assay were used to detect the expressions of interleukin (IL)-6 and monocyte chemoattractant protein-1 (MCP-1). The levels of Bax, cleaved-caspase-3, and cell pathways-related proteins were tested by western blot. Besides, the levels of miR-15 and MIAT2 were tested by RT-qPCR. We found that LPS declined cell viability and heightened apoptosis and levels of Bax, cleaved-caspase-3, IL-6, and MCP-1. MIAT2 was negatively regulated by LPS and it alleviated LPS-induced damage. Furthermore, MIAT2 reversely regulated miR-15 and miR-15 mimic could reverse the effects of MIAT2. Finally, MIAT2 restrained the p38MAPK and NF-κB pathways by downregulating miR-15. In conclusion, MIAT2 alleviated LPS-induced inflammation damage in WI-38 cells by sponging miR-15 via p38MAPK and NF-κB 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.

Role of Circular RNAs in Preeclampsia

Circular RNAs (circRNAs) are noncoding RNAs characterized by circular covalently closed structures, which are generated by back-splicing. circRNA is more stable and conserved than linear RNA and exists in various organisms. Preeclampsia (PE), a common hypertensive disorder of pregnancy, has a profound impact on maternal and neonatal mortality and morbidity. Recent studies demonstrated that circRNAs were differentially expressed in PE maternal-fetal interface compared with those in the control and might mediate pathological processes in pregnancy complications. However, the mechanisms of action of circRNAs in PE are still unclear. Here, we provide a comprehensive review on the current state of knowledge on circRNAs associated with PE. We summarize the known expression profiles of circRNAs and discuss their potential application as biomarkers of PE. The possible mechanisms underlying circRNA dysregulation in the etiology of PE are also explored.

Knockdown of CYP1B1 suppresses the behavior of the extravillous trophoblast cell line HTR-8/SVneo under hyperglycemic condition

Introduction: Trophoblast plays a vital role in the embryonic implantation and function of the placenta. Exposure to a hyperglycemic environment results in the abnormal function of trophoblasts during fetoplacental development, which leads to maternal complications and poor fetal outcomes. However, the precise mechanisms of placental pathology during hyperglycemia remain elusive. We investigated the role of CYP1B1 in the functional behavior of the extravillous trophoblast (EVT) cell line HTR-8/SVneo under hyperglycemic condition.Methods: We determined the expression of CYP1B1 via real-time polymerase chain reaction and Western blot. Specific CYP1B1 inhibitors and small interfering RNA were used to knockdown CYP1B1, whereas an agonist and an adenovirus were used to overexpress CYP1B1. The proliferation, migration, and invasion of the EVT cell line (i.e. HTR-8/SVneo) were assessed via colony formation, 5-ethynyl-2-deoxyuridine, wound healing, and transwell assay.Results: CYP1B1 is highly expressed in placentas from women with gestational diabetes mellitus. The blockage of CYP1B1 inhibits EVT activities induced by hyperglycemia in vitro, including proliferation, migration, and invasion, whereas the exogenous expression of CYP1B1 exhibits the opposite effects.Discussion: Our study may offer a new method for regulating EVT motility under hyperglycemic condition via CYP1B1.

Elevated MicroRNA-181a-5p Contributes to Trophoblast Dysfunction and Preeclampsia

OBJECTIVE

It has been demonstrated that preeclampsia is associated with alterations in placental microRNA expression. Previous reports have shown that hsa-miR-181a-5p is overexpressed in human preeclamptic placenta compared with normotensive placenta. The purpose of this study was to explore whether upregulated hsa-miR-181a-5p expression is involved in the ontogenesis of preeclampsia.

METHODS

Twenty preeclamptic placentas and 20 normotensive placentas were obtained from nulliparous women by cesarean section. Expression of hsa-miR-181a-5p in placenta tissues and human trophoblast cell lines was analyzed by reverse transcription polymerase chain reaction. The trophoblast cell lines (HTR-8/SVneo and JAR) were transfected with specific oligonucleotides to upregulate miR-181a-5p expression. The effect of miR-181a-5p expression on proliferation, cell cycle, apoptosis, and invasion in HTR-8/SVneo and JAR cells was then investigated.

RESULT

It was demonstrated that hsa-miR-181a-5p expression was upregulated in preeclamptic placentas and that it may trigger antiproliferation and inhibition of cell cycle progression, induce apoptosis, and suppress invasion in HTR-8/SVneo and JAR cells.

CONCLUSION

Anomalously upregulated hsa-miR-181a-5p expression could contribute to trophoblast dysfunction and may be a crucial factor in the pathogenesis of preeclampsia.

Downregulated MALAT1 relates to recurrent pregnancy loss via sponging miRNAs

Recurrent pregnancy loss (RPL) is three or more times of consecutive spontaneous loss of pregnancy. The underlying cause is complicated and the etiology of over 50% of RPL patients is unclear. Metastasis associated lung adenocarcinoma transcript-1 (MALAT-1), a multiple lncRNA functions as key regulators of diverse cellular processes. In this study, we found a reduced MALAT1 level in the villus samples of 36 RPL patients. Predicted by bioinformatics tool and confirmed by dual luciferase assay, we identified that MALAT1 directly interacts with miRNAs. Subsequent functional study in HTR-8/SVneo and HUVEC cells indicated that MALAT1 modulates the cell proliferation, apoptosis, migration and invasion via directly interact with miR-383, miR-15, miR-205 and miR-375. By modulating the VEGFA expression, MALAT1 controls the capillary formation of HUVEC cells. In conclusion, MALAT1 as a functional lncRNA controls cell proliferation, apoptosis, migration, invasion and modulates blood vessel formation. Down regulated MALAT1 induced disordered cross-talk between embryo and mother is one of the factor contributes to the pathogenesis of RPL.

Ten-eleven translocation 2 demethylates the MMP9 promoter, and its down-regulation in preeclampsia impairs trophoblast migration and invasion

Preeclampsia is the most common clinical disorder in pregnancy and might result from disordered uterine environments caused by epigenetic modifications, including deregulation of DNA methylation/demethylation. Recent research has indicated that 5-hydroxymethylcytosine (5hmC), a DNA base derived from 5-methylcytosine (5mC) via oxidation by ten-eleven translocation (TET) enzymes, is involved in DNA methylation-related plasticity. Here, we report that TET2 expression and 5hmC abundance are significantly altered in the placentas from preeclampsia patients. shRNA-mediated TET2 knockdown (shTET2) reduced trophoblast migration and invasion when cultured in Matrigel. Both real-time PCR of matrix metalloproteinase (MMP)-related transcripts and a human angiogenesis antibody array indicated that TET2 knockdown in trophoblasts inhibits the expression of MMP transcript, of which MMP9 represented one of the most significant TET2 downstream targets. Using an established shTET2 HTR-8/SVneo cell model, we further confirmed alterations of 5hmC levels and MMP9 expression at both mRNA and protein levels. In particular, we found that TET2 bound to and removed 5mC modifications at the MMP9 promoter region. Interestingly, in TET2 knockdown cells, both MMP9 expression and the compromised trophoblast phenotype could be rescued by vitamin C, an activator of TET enzyme activity. Finally, TET2 expression correlated with MMP9 levels in placenta samples from the preeclampsia patients, indicating that TET2 deregulation is critically involved in the pathogenesis of preeclampsia through down-regulation of MMP9 expression. Our findings highlight a critical role of TET2 in regulating trophoblast cell migration through demethylation at the MMP9 promoter, and suggest that down-regulation of the TET2-MMP9-mediated pathway contributes to preeclampsia pathogenesis.

Identification of microRNAs as potential markers of ovarian toxicity

Exposure to environmental toxicants has been associated with ovarian dysfunction yet sensitive biomarkers of adverse effect are lacking. We previously demonstrated that cigarette smoke exposure induced decreased relative ovarian weight, increased follicle loss and granulosa cell autophagy in mice. We postulate that cigarette smoke exposure will induce changes in the epigenome that can be used to reveal potential sensitive biomarkers of ovarian toxicity. Therefore, we evaluated differences in expression of 940 microRNAs (miRNAs), environmentally responsive small non-coding genes that regulate expression of genes at the post-transcriptional level, in ovarian tissue from 8-week-old female C57BL/6 mice exposed to room air or cigarette smoke 5 days per week for 8 weeks. A total of 152 miRNAs were dysregulated in expression, 17 of which were examined with quantitative polymerase chain reaction analysis. Using an online miRNA database tool, complete lists of predicted miRNA gene targets were generated, 12 of which were measured for their expression levels with quantitative polymerase chain reaction. An online bioinformatics resource database, DAVID generated functional classification lists of the target genes and their associated biological pathways. Results of the present pilot study suggest that miR-379, miR-15b, miR-691, miR-872 and miR-1897-5p are potentially useful markers of ovarian toxicity and dysfunction. Examination of the expression pattern of the target mRNA for these miRNA species demonstrated that cigarette smoke exposure induced significant changes that affect mitogen-activated protein kinase signaling pathways. We therefore suggest that miRNAs could serve as sensitive markers of ovarian toxicity and elucidate affected pathways.

Progress in the understanding of the etiology and predictability of fetal growth restriction

Fetal growth restriction (FGR) is defined as the failure of fetus to reach its growth potential for various reasons, leading to multiple perinatal complications and adult diseases of fetal origins. Shallow extravillous trophoblast (EVT) invasion-induced placental insufficiency and placental dysfunction are considered the main reasons for idiopathic FGR. In this review, first we discuss the major characteristics of anti-angiogenic state and the pro-inflammatory bias in FGR. We then elaborate major abnormalities in placental insufficiency at molecular levels, including the interaction between decidual leukocytes and EVT, alteration of miRNA expression and imprinted gene expression pattern in FGR. Finally, we review current animal models used in FGR, an experimental intervention based on animal models and the progress of predictive biomarker studies in FGR.Free Chinese abstract: A Chinese translation of this abstract is freely available at http://www.reproduction-online.org/content/153/6/R215/suppl/DC1.

Zika, dengue and yellow fever viruses induce differential anti-viral immune responses in human monocytic and first trimester trophoblast cells

Zika virus (ZIKV) is a mosquito-borne flavivirus associated with severe neonatal birth defects, but the causative mechanism is incompletely understood. ZIKV shares sequence homology and early clinical manifestations with yellow fever virus (YFV) and dengue virus (DENV) and are all transmitted in urban cycles by the same species of mosquitoes. However, YFV and DENV have been rarely reported to cause congenital diseases. Here, we compared infection with a contemporary ZIKV strain (FSS13025) to YFV17D and DENV-4 in human monocytic cells (THP-1) and first-trimester trophoblasts (HTR-8). Our results suggest that all three viruses have similar tropisms for both cells. Nevertheless, ZIKV induced strong type 1 IFN and inflammatory cytokine and chemokine production in monocytes and peripheral blood mononuclear cells. Furthermore, ZIKV infection in trophoblasts induced lower IFN and higher inflammatory immune responses. Placental inflammation is known to contribute to the risk of brain damage in preterm newborns. Inhibition of toll-like receptor (TLR)3 and TLR8 each abrogated the inflammatory cytokine responses in ZIKV-infected trophoblasts. Our findings identify a potential link between maternal immune activation and ZIKV-induced congenital diseases, and a potential therapeutic strategy that targets TLR-mediated inflammatory responses in the placenta.

miR-3074-5p Promotes the Apoptosis but Inhibits the Invasiveness of Human Extravillous Trophoblast-Derived HTR8/SVneo Cells In Vitro

OBJECTIVE

The objective of this study was to observe the effects of the overexpression of miR-3074-5p in human trophoblast cells in vitro.

DESIGN

Experimental in vitro study in HTR8/SVneo cells.

METHODS

HTR8/SVneo cells were transfected with miR-3074-5p mimic. The cell apoptosis and invasion were measured via flow cytometry and transwell assay, respectively. The expression levels of P53, Cyclin Dependent Kinase Inhibitor 1B (P27), BCL-2, BCL2 associated X (BAX), and BCL2 like 14 (BCL-G) in HTR8/SVneo cells were determined by Western blot. The alterations in gene expression profile of HTR8/SVneo cells were evaluated by complementary DNA microarray assay, and the differential expressions of dihydrolipoamide S-succinyltransferase (DLST), growth-associated protein 43 (GAP43), runt-related transcription factor 2 (RUNX2), and C-C type chemokine receptor 3 (CCR3) were validated by Western blot. Biofunctions of these differentially expressed genes were enriched by Gene Ontology analysis.

RESULTS

The overexpression of miR-3074-5p in HTR8/SVneo cells promoted cell apoptosis but inhibited cell invasion, being accompanied by the significantly elevated expressions of P27, BCL-2, and BCL-G. Meanwhile, an increased expression of P27 and P57 was also detected in a small sample size of placental villi of recurrent miscarriage (RM) patients. Totally, 411 genes and 397 genes were screened out, respectively, to be downregulated or upregulated at least by 2-folds in miR-3074-5p overexpressed HTR8/SVneo cells. These differentially expressed genes were involved in several important functions related to pregnancy. Subsequently, the reduced expressions of DLST and GAP43 proteins, as well as the increased expressions of CCR3 and RUNX2 proteins, were validated in miR-3074-5p overexpressed HTR8/SVneo cells.

CONCLUSION

These data suggested a potential contribution of miR-3074-5p in the pathogenesis of RM by disturbing the normal activities of trophoblast cells.

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.

HTR-8/SVneo cell line contains a mixed population of cells

INTRODUCTION

The placenta, a transient organ in humans, is essential for pregnancy maintenance and fetal development. Trophoblast and stromal cells are the main cell types present in human placenta. Trophoblast cells are derivatives of the trophectoderm layer and fulfill the endocrine, exchange, invasion and implantation processes of the placenta, whereas stromal cells are of extraembryonic mesenchymal origin and are important for villous formation and maintenance. Different cell lines were developed to study trophoblast functions including BeWo, JEG-3 and JAR from chorioncarcinoma while HTR-8/SVneo was developed using first trimester extravillous trophoblast infected with simian virus 40 large T antigen (SV40). These cell lines are largely used to study trophoblast functions including cell fusion, migration and invasion. Therefore, the purity of each cell lines is crucial in order to be able to use them as a model recapitulating trophoblast cells.

METHODS

HTR-8/SVneo, BeWo, JEG-3 and JAR were analyzed for epithelial and mesenchymal markers using immunofluorescence, real time PCR and Western blot.

RESULTS

Our results showed that HTR-8/SVneo cell line contains two populations of cells suggesting the presence of trophoblast and stromal/mesenchymal cells. While all cells in BeWo, JEG-3 and Jar are positive for the trophoblast/epithelial marker CK7, HTR-8/SVneo cells contained few clusters of CK7 positive cells. Interestingly, vimentin expression was detected in a subset of HTR-8/SVneo cells and was completely absent from all other tested placental cell lines.

DISCUSSION

Our results unveil the presence of a heterogeneous population of trophoblast and stromal cells within HTR-8/SVneo cell line. This mixed population of cells should be taken into consideration when using this cell line to study trophoblast functions.

MicroRNA-34a targets regulator of calcineurin 1 to modulate endothelial inflammation after fetal cardiac bypass in goat placenta

INTRODUCTION

Placental dysfunction characterized by vascular endothelial inflammation is one of the most notable responses to fetal cardiac bypass. Regulator of calcineurin 1 (RCAN1) is an important regulator of inflammatory responses. MicroRNAs (miRNAs) are essential post-transcriptional modulators of gene expression, and miRNA-34a (miR-34a) was showed to activate vascular endothelial inflammation. We hypothesized that miR-34a may be a key regulator of placental dysfunction after fetal cardiac bypass.

METHODS

We evaluated miRNA expression in goat placentas via small RNA sequencing, quantitative real-time polymerase chain reaction (qRT-PCR) and in situ hybridization. Expression of miRNA target genes was determined via bioinformatics analyses and dual luciferase reporter assays. Furthermore, human umbilical vein endothelial cells (HUVECs) were transfected with miR-34a or a control sequence. The RCAN1, nuclear factor of activated T-cells (NFATC1) and nuclear factor kappa-B (NF-κB) levels in HUVECs and placentas were evaluated via Western blot and qRT-PCR.

RESULTS

We demonstrated that miR-34a was highly enriched in goat placenta after cardiopulmonary bypass. Moreover, RCAN1 was identified as a novel direct target of miR-34a. Transfection of miR-34a led to decreased RCAN1 expression and increased NFATC1 and NF-κB expression in HUVECs. Conversely, inhibition of miR-34a rescued RCAN1 expression and reduced NFATC1 and NF-κB expression in HUVECs.

CONCLUSIONS

We demonstrated a remarkable role of miR-34a as a regulator of NFATC1-associated placental inflammation through direct targeting of RCAN1. MiR-34a could serve as a novel therapeutic target for limiting the progression of placental inflammation after fetal cardiac bypass.

miR-15b mediates oxaliplatin-induced chronic neuropathic pain through BACE1 down-regulation

BACKGROUND AND PURPOSE

Although oxaliplatin is an effective anti-cancer platinum compound, it can cause painful chronic neuropathy, and its molecular mechanisms are poorly understood. MicroRNAs (miRNAs) are small non-coding RNAs that negatively regulate gene expression in a sequence-specific manner. Although miRNAs have been increasingly recognized as important modulators in a variety of pain conditions, their involvement in chemotherapy-induced neuropathic pain is unknown.

EXPERIMENTAL APPROACH

Oxaliplatin-induced chronic neuropathic pain was induced in rats by i.p. injections of oxaliplatin (2 mg·kg^-1 ) for five consecutive days. The expression levels of miR-15b and β-site amyloid precursor protein-cleaving enzyme 1 (BACE1 also known as β-secretase 1) were examined in the dorsal root ganglion (DRG). To examine the function of miR-15b, an adeno-associated viral vector encoding miR-15b was injected into the DRG in vivo.

KEY RESULTS

Among the miRNAs examined in the DRG in the late phase of oxaliplatin-induced neuropathic pain, miR-15b was most robustly increased. Our in vitro assay results determined that BACE1 was a target of miR-15b. BACE1 and miR-15b were co-expressed in putative myelinated and unmyelinated DRG neurons. Overexpression of miR-15b in DRG neurons caused mechanical allodynia in association with reduced expression of BACE1. Consistent with these results, a BACE1 inhibitor dose-dependently induced significant mechanical allodynia.

CONCLUSIONS AND IMPLICATIONS

These findings suggest that miR-15b contributes to oxaliplatin-induced chronic neuropathic pain at least in part through the down-regulation of BACE1.

The function of miR-519d in cell migration, invasion, and proliferation suggests a role in early placentation

The processes of proliferation, migration, and invasion of extravillous trophoblasts are critical for placental implantation and early development, and directly influence pregnancy outcome. Dysregulation of these processes has been associated with placental dysfunction, implicated in clinical conditions such as preeclampsia and placental accreta. Among diverse microRNA (miRNA) species that are expressed in placental trophoblasts, members of the chromosome 19 miRNA cluster (C19MC) stand out in their nearly exclusive expression in the placenta. Recent research on the function of C19MC miRNAs in normal cell physiology and during tumorigenesis identified one C19MC member, miR-519d, as a regulator of cell migration, invasion, and interaction with the extracellular matrix. In this review, we focus on the function of miR-519d in placental trophoblasts, where miR-519d regulates cell migration and invasion, and its aberrant expression is associated with preeclampsia. In cancer, the function of miR-519d as an oncomiR or a tumor-suppressor is dependent upon the tumor type. Further research on the biological function and regulation of miR-519d may illuminate previously unknown mechanisms that control cell migration and invasion.