LncRNA MALAT1 affects the migration and invasion of trophoblast cells by regulating FOS expression in early-onset preeclampsia

Long non-coding RNAs: a summary of their roles in placenta development and pathology†

Long non-coding RNAs are cellular transcripts that have ˃200 nucleotides in length and do not code for proteins. Due to their low expression levels, long non-coding RNAs were previously considered as mere transcriptional noise. However, current evidence indicates that they regulate a myriad of biological processes such as cell proliferation, invasion, and apoptosis. Hence, their expression patterns are crucial indicators of the physiological or pathological states of cells, tissues, and organs. The utilization of long non-coding RNAs as biomarkers and therapeutic targets for the clinical management of several diseases have been suggested. Gradually, long non-coding RNAs are gaining a substantial attention in the field of feto-maternal medicine. After embryo implantation, the interactions between the trophoblast cells from the embryo and the uterus of the mother facilitate placenta development and pregnancy progression. These processes are tightly regulated, and their impairments result in pregnancy pathologies such as miscarriage and preeclampsia. Accumulating evidence implicates long non-coding RNAs in these processes. Herein, we have summarized the roles of several long non-coding RNAs in human placenta development, have proposed some mechanisms by which they participate in physiological and pathological placentation, have revealed some knowledge deficits, and have recommended ideal experimental approaches that will facilitate the clarification of the mechanistic actions of each long non-coding RNA at the feto-maternal interface during healthy and pathological pregnancies.

Mechanistic actions of long non-coding RNA MALAT1 within the ovary and at the feto-maternal interface

Long non-coding RNAs (LncRNAs) are being unveiled as crucial regulators of several biological processes and pathways. Among the lncRNAs is metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), which is also known as nuclear enriched abundant transcript 2 (NEAT2). MALAT1 is highly conserved in mammals, and controls cellular processes such as proliferation, migration, invasion, angiogenesis, and apoptosis in both physiological and pathological conditions. Roles of MALAT1 in the female reproductive system are gradually getting explored. Within the ovarian micro-environment, the physiological expression of MALAT1 potentially modulates folliculogenesis while its upregulation promotes the metastasis of epithelial ovarian cancers. Interestingly, women with polycystic ovary syndrome have been shown to exhibit aberrant ovarian expression of MALAT1 and this is believed to contribute to the development of the disease. At the feto-maternal interface, MALAT1 potentially promotes trophoblast development. While its placental downregulation is linked to the pathogenesis of preeclampsia, its placental upregulation is associated with placenta increta and placenta percreta. Hence, abnormal expression of MALAT1 is a candidate molecular biomarker and therapeutic target for the treatment of these obstetric and gynecologic anomalies. To enhance a quick uncovering and detailed characterization of the mechanistic actions of MALAT1 in the female reproductive system, we have highlighted some knowledge deficits and have recommended ideal experimental models to be employed in prospective investigations.

The Role of ncRNAs in the Immune Dysregulation of Preeclampsia

The main complications causing practically 75% of all maternal deaths are severe bleeding, infections, and high blood pressure during pregnancy (preeclampsia (PE) and eclampsia). The usefulness of ncRNAs as clinical biomarkers has been explored in an extensive range of human diseases including pregnancy-related diseases such as PE. Immunological dysregulation show that the Th1/17:Th2/Treg ratio is "central and causal" to PE. However, there is evidence of the involvement of placenta-expressed miRNAs and lncRNAs in the immunological regulation of crucial processes of placenta development and function during pregnancy. Abnormal expression of these molecules is related to immune physiopathological processes that occur in PE. Therefore, this work aims to describe the importance of miRNAs and lncRNAs in immune dysregulation in PE. Interestingly, multiple ncRNAS are involved in the immune dysregulation of PE participating in type 1 immune response regulation, immune microenvironment regulation in placenta promoting inflammatory factors, trophoblast cell invasion in women with Early-Onset PE (EOPE), placental development, and angiogenesis, promotion of population of M1 and M2, proliferation, invasion, and migration of placental trophoblast cells, and promotion of invasion and autophagy through vias such as PI3K/AKT/mTOR, VEGF/VEGFR1, and TLR9/STAT3.

Trophoblast Cell Function in the Antiphospholipid Syndrome

Antiphospholipid syndrome (APS) is a complex thrombo-inflammatory autoimmune disease characterized by the presence of antiphospholipid antibodies (aPL). Women with APS are at high risk of recurrent early pregnancy loss as well as late obstetrical complications-premature birth due to placental insufficiency or severe preeclampsia. Accumulating evidence implies that vascular thrombosis is not the only pathogenic mechanism in obstetric APS, and that the direct negative effect of aPL on the placental cells, trophoblast, plays a major role. In this review, we summarize the current findings regarding the potential mechanisms involved in aPL-induced trophoblast dysfunction. Introduction on the APS and aPL is followed by an overview of the effects of aPL on trophoblast-survival, cell function and aPL internalization. Finally, the implication of several non-coding RNAs in pathogenesis of obstetric APS is discussed, with special emphasis of their possible role in trophoblast dysfunction and the associated mechanisms.

LncRNA RP4-639F20.1 interacts with THRAP3 to attenuate atherosclerosis by regulating c-FOS in vascular smooth muscle cells proliferation and migration

BACKGROUND AND AIMS

The aberrant proliferation and migration of vascular smooth muscle cells (VSMCs) play an essential role in the pathogenesis of atherosclerosis (AS). Long noncoding RNAs (lncRNAs) have been reported as important regulators in a number of diseases. However, very little is known regarding the functional role of lncRNAs in governing proliferation and migration of VSMCs and AS development.

METHODS

Both in vitro and in vivo assays were performed to investigate the role of lncRNA in the pathophysiology of AS. Our previous lncRNA arrays revealed that lncRNA RP4-639F20.1 was significantly decreased in atherosclerotic plaques. Lentivirus overexpressing RP4-639F20.1 and lncRNA RP4-639F20.1 silencing vectors (Si-lnc-RP4-639F20.1) were constructed and transfected in VSMCs. The in vitro functions of lncRNA were analyzed by CCK-8 assays, EdU assays, scratch wound assays, transwell assays, qRT-PCR and Western blot analyses. RNA fluorescence in situ hybridization, immunoprecipitation and mRNA microarrays were used to explore the underlying mechanism. Adeno-associated-virus-9 (AAV9) overexpressing RP4-639F20.1 was constructed and injected intravenously into ApoE-/- mice to explore the role of lncRNA in vivo.

RESULTS

In vitro experiments showed that lncRNA RP4-639F20.1 interacted with THRAP3 and downregulated c-FOS expression. Both increase of lncRNA RP4-639F20.1 expression and knockdown of c-FOS inhibited the expression of MMP10 and VEGF-α in VSMCs and suppressed VSMCs proliferation and migration. In vivo experiments using ApoE-/- mice fed a high-fat diet demonstrated that lncRNA RP4-639F20.1 overexpression deterred atherosclerosis and decreased lipid levels in atherosclerotic lesions. Patients with coronary artery disease were found to have higher c-FOS levels than healthy individuals and c-FOS expression was positively correlated with the SYNTAX score of patients.

CONCLUSIONS

Overall, these data indicated that lncRNA RP4-639F20.1/THRAP3/c-FOS pathway protects against the development of atherosclerosis by suppressing VSMCs proliferation and migration. LncRNA RP4-639F20.1 and c-FOS could represent potential therapeutic targets to ameliorate atherosclerosis-related diseases.

Transcription factor c-fos induces the development of premature ovarian insufficiency by regulating MALAT1/miR-22-3p/STAT1 network

BACKGROUND

The current study attempted to investigate the role of transcription factor c-fos in the development of premature ovarian insufficiency (POI) as well as the underlying mechanism involving the MALAT1/miR-22-3p/STAT1 ceRNA network.

METHODS

Bioinformatics analysis was performed to extract POI-related microarray dataset for identifying the target genes. Interaction among c-fos, MALAT1, miR-22-3p, and STAT1 was analyzed. An in vivo POI mouse model was prepared followed by injection of sh-c-fos and sh-STAT1 lentiviruses. Besides, an in vitro POI cell model was constructed to study the regulatory roles of c-fos, MALAT1, miR-22-3p, and STAT1.

RESULTS

c-fos, MALAT1, and STAT1 were highly expressed in ovarian tissues from POI mice and CTX-induced KGN cells, while miR-22-3p was poorly expressed. c-fos targeted MALAT1 and promoted MALAT1 transcription. MALAT1 competitively bound to miR-22-3p and miR-22-3p could suppress STAT1 expression. Mechanically, c-fos aggravated ovarian function impairment in POI mice and inhibited KGN cell proliferation through regulation of the MALAT1/miR-22-3p/STAT1 regulatory network.

CONCLUSION

Our findings highlighted inducing role of the transcription factor c-fos in POI through modulation of the MALAT1/miR-22-3p/STAT1 ceRNA network.

Reversal of H2O2-induced cell death by knockdown of HOTAIR in HTR-8/SVneo cells by mediation of miR-106b-5p/ACSL4 axis

Preeclampsia is a serious threat to the health of pregnant women. Injury of trophoblasts could contribute to the progression of preeclampsia, and H₂O₂ was able to induce apoptosis in trophoblasts. LncRNAs have been reported to be involved in the progression of preeclampsia. Additionally, lncRNA HOTAIR is upregulated in patients with preeclampsia. However, the function of HOTAIR in H₂O₂-treated trophoblasts remains unclear. To explore the function of HOTAIR in preeclampsia, HTR-8/SVneo cells were stimulated with H₂O₂. RT-qPCR was performed to measure HOTAIR expression in HTR-8/SVneo cells. The apoptosis of HTR-8/SVneo cells was measured using TUNEL staining. The mitochondrial membrane potential was measured using JC-1 staining. Western blotting was performed to detect the expression of ACSL4, GPX4, and FTH1 in HTR-8/SVneo cells. The level of HOTAIR in HTR-8/SVneo cells was upregulated by H₂O₂. In addition, H₂O₂ notably inhibited the proliferation of HTR-8/SVneo cells, whereas knockdown of HOTAIR reversed this phenomenon. The mitochondrial membrane potential in HTR-8/SVneo cells was significantly inhibited by H₂O₂ and partially abolished by HOTAIR silencing. Moreover, HOTAIR could bind to miR-106b-5p; ACSL4 was identified as the downstream target of miR-106b-5p. Furthermore, HOTAIR knockdown reversed H₂O₂-induced ferroptosis in HTR-8/SVneo cells by regulating miR-106b-5p/ACSL4. Collectively, the knockdown of HOTAIR reversed H₂O₂-induced ferroptosis in HTR-8/SVneo cells by mediating miR-106b-5p/ACSL4. Thus, HOTAIR may serve as a new therapeutic target against preeclampsia.

LINC00240/miR-155 axis regulates function of trophoblasts and M2 macrophage polarization via modulating oxidative stress-induced pyroptosis in preeclampsia

Background

This study aimed to investigate the effects of LINC00240/miR-155/Nrf2 axis on trophoblast function and macrophage polarization in the pathogenesis of preeclampsia.

Methods

Bindings between LINC00240, miR-155 and Nrf2 were validated by dual luciferase reporter assay or RNA-immunoprecipitation. Cell proliferation, migration, invasion, and pyroptosis were detected by CCK-8, clone formation, wound healing, Transwell system, and flow cytometry, respectively. Macrophage polarization was tested by flow cytometry. The expression levels of LINC00240, miR-155, Nrf2, and oxidative stress and pyroptosis-related markers in in vitro and in vivo preeclampsia models were analyzed by qPCR, western blot, or ELISA assays. Blood pressure, urine protein levels, liver and kidney damages, and trophoblast markers in placenta tissues were further studied in vivo.

Results

Placenta tissues from preeclampsia patients and animals showed decreased LINC00240 and Nrf2 and increased miR-155 expression levels, and the decreased M2 macrophage polarization. LINC00240 directly bound and inhibited expression of miR-155, which then inhibited oxidative stress-induced pyroptosis, promoting proliferation, migration and invasion abilities of trophoblasts, and M2 macrophage polarization. Inhibition of miR-155 led to increased Nrf2 expression and similar changes as LINC00240 overexpression in trophoblast function and macrophage polarization. Overexpression of LINC00240 in in vivo preeclampsia model decreased blood pressure, urine protein, liver and kidney damages, increased fetal weight and length, and induced trophoblast function and M2 macrophage polarization.

Conclusion

LINC00240 inhibited symptoms of preeclampsia through regulation on miR-155/Nrf2 axis, which suppressed oxidative stress-induced pyroptosis to improve trophoblast function and M2 macrophage polarization. LINC00240 could be a potential therapeutic target for preeclampsia.

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.

lncRNA XIST is associated with preeclampsia and mediates trophoblast cell invasion via miR-340-5p/KCNJ16 signaling pathway

BACKGROUND

Preeclampsia (PE) is a syndrome commonly occurring among the pregnant. Shallow trophoblast invasion is considered to be closely related to PE. Therefore, in trophoblast cells, we explored the potential mechanisms of lncRNA XIST in the modulation of trophoblast invasion and proliferation.

METHODS

GEO online analyzer was used to screen the abnormally expressed RNAs in placenta tissues from patients with severe PE and healthy controls. The prediction of target bindings was performed on TargetScan and starBase. Transfection was conducted to regulate the RNA expression levels in trophoblast cells, HTR-8/SVneo. RT-qPCR measured expression of lncRNA XIST, miR-340-5p and KCNJ16. The CCK-8 assay examined cell viability. Flow cytometer analyzed apoptosis and luciferase assay determined the luciferase activity. Transwell assays detected the invasion and western blot verified the changes in protein expression of MMP2, MMP9 and KCNJ16 in trophoblast cells.

RESULTS

lncRNA XIST expression was enhanced in PE patients. Upregulation of lncRNA XIST in HTR-8/SVneo cells inhibited the cell proliferation and invasion, and induced apoptosis. XIST upregulation inhibited MMP2 and MMP9 protein expression. lncRNA XIST/ KCNJ16 interplayed as ceRNAs of miR-340-5p. Specifically,miR-340-5p overexpression reversed the effect of XIST upregulation on the cell apoptosis, proliferation and invasive ability and the knockdown of KCNJ16 could add to the effect of miR-340-5p overexpression in HTR-8/SVneo.

CONCLUSION

lncRNA XIST was upregulated in PE. Upregulation of lncRNA XIST exerted the inhibitory effects on the proliferation and invasion of trophoblast cells through the interactions with miR-340-5p/KCNJ16, which suggests that the lncRNA XIST/miR-340-5p/KCNJ16 axis might play a role in PE.

Long Non-Coding RNA Prostate Cancer Non-Coding RNA 1/miR-211-5p/Death Effector Domain Containing 2 Axis Affects Preeclampsia by Modulating Trophoblast Cells Proliferation and Apoptosis

Background: Preeclampsia (PE) is a pregnancy-specific hypertensive disorder that affects 5–7% of pregnant women and is characterized by edema, hypertension and proteinuria. It is one of the leading causes of morbidity and mortality in pregnant women and newborns. Evidences reveal that the expression of long non-coding RNA (lncRNA) prostate cancer non-coding RNA 1 (PRNCR1) is abnormal in PE. Therefore, we investigated the role of lncRNA PRNCR1 in PE development and its molecular mechanism. Methods: Quantitative reverse transcription PCR (qRT-PCR) was used to determine the expression levels of lncRNA PRNCR1, microRNA (miR)-211-5p and mRNA leval of death effector domain containing 2 (DEDD2). Besides, the expression level of DEDD2 was detected by western blot assay. Cell proliferation ability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay, and cell apoptosis was detected by flow cytometry assay. Transwell assay was used to detect the migration and invasion of HTR-8/SVneo cells. The relationship between miR-211-5p and lncRNA PRNCR1 or DEDD2 was verified by dual luciferase reporter gene assay. Results: Over-expression of lncRNA PRNCR1 induced apoptosis, impeded proliferation, migration, invasion in HTR-8/SVneo cells. Knockdown of lncRNA PRNCR1 inhibited apoptosis, promoted cell proliferation, migration and invasion, and all these effects were offset by miR-211-5p inhibitor. The mRNA and protein levels of DEDD2 were decreased by overexpressing miR-211-5p in HTR-8/SVneo cells, while miR-211-5p inhibitor significantly increased the mRNA and protein levels of DEDD2. Conclusions: lncRNA PRNCR1 regulated cell behavior (proliferation, apoptosis, migration, and invasion) via the miR-211-5p/DEDD2 axis in HTR-8/SVneo cells. Thus, lncRNA PRNCR1 participated in the occurrence and development of PE.

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.

(Dis)similarities between the Decidual and Tumor Microenvironment

Placenta-specific trophoblast and tumor cells exhibit many common characteristics. Trophoblast cells invade maternal tissues while being tolerated by the maternal immune system. Similarly, tumor cells can invade surrounding tissues and escape the immune system. Importantly, both trophoblast and tumor cells are supported by an abetting microenvironment, which influences invasion, angiogenesis, and immune tolerance/evasion, among others. However, in contrast to tumor cells, the metabolic, proliferative, migrative, and invasive states of trophoblast cells are under tight regulatory control. In this review, we provide an overview of similarities and dissimilarities in regulatory processes that drive trophoblast and tumor cell fate, particularly focusing on the role of the abetting microenvironments.

Epigenetic regulation of epithelial to mesenchymal transition: a trophoblast perspective

Epigenetic changes alter expression of genes at both pre- and post-transcriptional levels without changing their DNA sequence. Accumulating evidence suggests that such changes can modify cellular behaviour and characteristics required during development and in response to various extracellular stimuli. Trophoblast cells develop from the outermost trophectoderm layer of the blastocyst and undergo many phenotypic changes as the placenta develops. One such phenotypic change is differentiation of the epithelial natured cytotrophoblasts into the mesenchymal natured extravillous trophoblasts. The extravillous trophoblasts are primarily responsible for invading into the maternal decidua and thus establishing connection with the maternal spiral arteries. Any dysregulation of this process can have adverse effects on the pregnancy outcome. Hence, tight regulation of this epithelial-mesenchymal transition is critical for successful pregnancy. This review summarizes the recent research on the epigenetic regulation of the epithelial-mesenchymal transition occurring in the trophoblast cells during placental development. The functional significance of chemical modifications of DNA and histone, which regulate transcription, as well as non-coding RNAs, which control gene expression post-transcriptionally, is discussed in relation to trophoblast biology.

Circulating MicroRNAs in the Second Trimester From Pregnant Women Who Subsequently Developed Preeclampsia: Potential Candidates as Predictive Biomarkers and Pathway Analysis for Target Genes of miR-204-5p

MicroRNAs (miRNAs) play an important role in the pathophysiology of preeclampsia (PE). However, the expression of circulating miRNAs was not analyzed in the second trimester of pregnancy, a period of major relevance to identify predictive biomarkers for PE. Therefore, we examined the expression profiles of 84 circulating miRNAs using a PCR array in plasma collected between 20 and 25 weeks of gestation from pregnant women, who subsequently developed PE and those who remained healthy during pregnancy, randomly selected from a prospective cohort. Overall, 23 miRNAs had a fold change > 2.0 and were considered to be upregulated in plasma from pregnant women who subsequently developed PE, even before the onset of clinical symptoms of PE. However, only miR-204-5p was statistically significant (P = 0.0082). Experimentally validated interactions for the target genes of miR-204-5p extracted from miRTarBase were used in the gene set functional enrichment analysis to identify Reactome pathways. The network connecting the 37 target genes for miR-204-5p revealed pathways of known pathophysiological relevance during the early development of PE and included key genes related to PE, such as BDNF, MMP-9, MALAT1, TGFBR2, and SIRT1. We further depicted downstream targets of SIRT1 that are related to the vascular endothelial function or implicated in the pathophysiology of PE, namely, FOXO1, NFκB, HIF-1α, NOS3, and PPAR-γ. Our novel findings provide for circulating miRNAs upregulated in the second trimester on plasma from pregnant women who subsequently developed PE that is potentially related to the early development of PE, which may guide further studies focused on the validation of potential predictive biomarkers in PE.

Role of lncRNA BCYRN1 in trophoblast cell physiology and pathogenesis of preeclampsia

Long non-coding RNAs (lncRNAs) may play a key role in the pathogenesis of preeclampsia (PE). The present study investigated the role of the lncRNA brain cytoplasmic RNA 1 (BCYRN1) in PE. A total of 30 patients with severe PE (SPE) and 30 patients with mild PE (MPE) were recruited, whilst 30 healthy pregnant individuals were enrolled as controls. Placental tissues of enrolled subjects were collected after delivery. The clinical data of pregnant women and newborns were recorded before the correlation between BCYRN1 expression and clinical characteristics was analyzed. Furthermore, HTR-8/SVneo cells were transfected with BCYRN1 overexpression plasmids and BCYRN1 small interfering (si)RNA. Cell Counting Kit-8, Transwell, flow cytometry and tube formation assays were used to detect the function of BCYRN1 in HTR-8/SVneo cells. Reverse transcription-quantitative PCR was used to detect BCYRN1 expression in placental tissues and HTR-8/SVneo cells. Western blotting was used to detect the protein expression levels of Wnt1 and β-catenin. BCYRN1 expression was lower in placenta with mild PE compared with in normal placenta, and was in turn lower in placenta with severe PE. BCYRN1 was negatively correlated with systolic blood pressure and 24-h urinary protein in patients with PE. BCYRN1 siRNA inhibited cell viability, migration, invasion and tube forming abilities whilst increasing apoptosis. By contrast, BCYRN1 overexpression conferred opposite effects. The levels of Wnt1 and β-catenin expression in the cells and placental tissues were next measured. Cells overexpressing BCYRN1 were further treated with the Wnt pathway inhibitor XAV939. Wnt1 and β-catenin expression were elevated when BCYRN1 was overexpressed, but were decreased after BCYRN1 knockdown. XAV939 attenuated the effect of BCYRN1 overexpression on HTR-8/SVneo cells. Overall, the resulted indicated that upregulation of BCYRN1 increased trophoblast viability and prevented apoptosis by activating the Wnt/β-catenin pathway to delay PE onset.

Roles of noncoding RNAs in preeclampsia

Preeclampsia (PE) is an idiopathic disease that occurs during pregnancy. It comprises multiple organ and system damage, and can seriously threaten the safety of the mother and infant throughout the perinatal period. As the pathogenesis of PE is unclear, there are few specific remedies. Currently, the only way to eliminate the clinical symptoms is to terminate the pregnancy. Although noncoding RNA (ncRNA) was once thought to be the "junk" of gene transcription, it is now known to be widely involved in pathological and physiological processes, including pregnancy-related disorders. Moreover, there is growing evidence that the unbalanced expression of specific ncRNA is involved in the pathogenesis of PE. In the present review, we summarize the expression patterns of ncRNAs, i.e., microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs), and the functional mechanisms by which they affect the development of PE, and examine the clinical significance of ncRNAs as biomarkers for the diagnosis of PE. We also discuss the contributions made by genetic polymorphisms and epigenetic ncRNA regulation to PE. In the present review, we wish to explore and reinforce the clinical value of ncRNAs as noninvasive biomarkers of PE.

The Role of Long Non-Coding RNAs in Trophoblast Regulation in Preeclampsia and Intrauterine Growth Restriction

Preeclampsia (PE) and Intrauterine Growth Restriction (IUGR) are two pregnancy-specific placental disorders with high maternal, fetal, and neonatal morbidity and mortality rates worldwide. The identification biomarkers involved in the dysregulation of PE and IUGR are fundamental for developing new strategies for early detection and management of these pregnancy pathologies. Several studies have demonstrated the importance of long non-coding RNAs (lncRNAs) as essential regulators of many biological processes in cells and tissues, and the placenta is not an exception. In this review, we summarize the importance of lncRNAs in the regulation of trophoblasts during the development of PE and IUGR, and other placental disorders.

Recent Advances of MicroRNAs, Long Non-coding RNAs, and Circular RNAs in Preeclampsia

Preeclampsia is a clinical syndrome characterized by multiple-organ dysfunction, such as maternal hypertension and proteinuria, after 20 weeks of gestation. It is a common cause of fetal growth restriction, fetal malformation, and maternal death. At present, termination of pregnancy is the only way to prevent the development of the disease. Non-coding RNAs, including microRNAs, long non-coding RNAs, and circular RNAs, are involved in important pathological and physiological functions in life cycle activities including ontogeny, reproduction, apoptosis, and cell reprogramming, and are closely associated with human diseases. Accumulating evidence suggests that non-coding RNAs are involved in the pathogenesis of preeclampsia through regulation of various physiological functions. In this review, we discuss the current evidence of the pathogenesis of preeclampsia, introduce the types and biological functions of non-coding RNA, and summarize the roles of non-coding RNA in the pathophysiological development of preeclampsia from the perspectives of oxidative stress, hypoxia, angiogenesis, decidualization, trophoblast invasion and proliferation, immune regulation, and inflammation. Finally, we briefly discuss the potential clinical application and future prospects of non-coding RNA as a biomarker for the diagnosis of preeclampsia.

Differential expression of serum proteins before 20 weeks gestation in women with hypertensive disorders of pregnancy: A potential role for SH3BGRL3

INTRODUCTION

The objective of this study was to explore serum levels of differentially abundant proteins between women with hypertensive disorders of pregnancy (HDP) and women with normal-term pregnancy, and to explore the contribution of SH3BGRL3 to the pathogenesis of HDP.

METHODS

At 6-20 weeks gestation 48 pregnant women who later developed HDP (HDP group) and 48 women with normal-term pregnancy (normal group) were recruited based on maternal age and gestational age at a 1:1 ratio. Total serum protein was extracted, denatured, deoxidized, and subjected to enzymolysis. The sample was labeled with Tandem Mass Tags and analyzed via mass spectroscopy to identify differentially abundant proteins. The role of SH3BGRL3 in trophoblast invasion, proliferation and apoptosis was examined using the HTR-8/SVneo cell line and primary isolates of extravillous trophoblast (EVT) cells.

RESULTS

In the proteomic profiling analysis, there were 19 proteins that showed significant differential abundance (P < 0.05). Among them, 13 proteins were more abundant and 6 proteins were less abundant in the serum from the HDP group compared with the normal group. The function of one of the more abundant proteins, SH3BGRL3, in trophoblast cell invasion, proliferation and apoptosis was investigated. Treatment of the EVT cells or the HTR-8/SVneo cell line with anti-SH3BGRL3 inhibited proliferation, but stimulated both apoptosis and invasion. MMP2 and p-ERK levels were also decreased in EVT after anti-SH3BGRL3 treatment.

DISCUSSION

The SH3BGRL3 protein can regulate various aspects of trophoblast biology, and may be useful in the clinical diagnosis of HDP.

LncRNA TUG1 regulates the balance of HuR and miR-29b-3p and inhibits intestinal epithelial cell apoptosis in a mouse model of ulcerative colitis

This study aimed to investigate the role of long non-coding RNA (lncRNA) taurine up-regulated 1 (TUG1) in the development of ulcerative colitis (UC) and to explore the underlying mechanisms. A murine model of UC was induced by dextran sodium sulfate (DSS) exposure. The colonic epithelial YAMC cells were treated with TNF-α to simulate the inflammatory environment of intestinal epithelial cells (IECs). RNA pull-down and RIP assays were performed to analyze the interaction between TUG1 and HuR. Luciferase activity assay was conducted to evaluate the interaction between TUG1 and miR-29b-3p. Cell proliferation was evaluated by MTT assay. Cell apoptosis was assessed by flow cytometry and western blot analysis of apoptosis-related proteins. TUG1 overexpression promoted cell proliferation and inhibited cell apoptosis in the TNF-α-stimulated YAMC cells. The mechanistic analysis showed that TUG1 positively regulated the HuR/c-myc axis via its interaction with HuR, leading to upregulation of c-myc expression; meanwhile, TUG1 negatively regulated the miR-29b-3p/CDK2 signaling via binding to miR-29b-3p, leading to derepression of CDK2 expression. Further animal experiments showed that TUG1 overexpression attenuated UC progression in the DSS-induced UC in mice. Collectively, TUG1 inhibits IEC apoptosis and UC progression by regulating the balance of HuR and miR-29b-3p.