Hypoxia-inducible microRNA-218 inhibits trophoblast invasion by targeting LASP1: Implications for preeclampsia development

Hypoxia causes trophoblast cell ferroptosis to induce miscarriage through lnc-HZ06/HIF1α-SUMO/NCOA4 axis

Defects of human trophoblast cells may induce miscarriage (abnormal early embryo loss), which is generally regulated by lncRNAs. Ferroptosis is a newly identified iron-dependent programmed cell death. Hypoxia is an important and unavoidable feature in mammalian cells. However, whether hypoxia might induce trophoblast cell ferroptosis and then induce miscarriage, as well as regulated by a lncRNA, was completely unknown. In this work, we discovered at the first time that hypoxia could result in ferroptosis of human trophoblast cells and then induce miscarriage. We also identified a novel lncRNA (lnc-HZ06) that simultaneously regulated hypoxia (indicated by HIF1α protein), ferroptosis, and miscarriage. In mechanism, HIF1α-SUMO, instead of HIF1α itself, primarily acted as a transcription factor to promote the transcription of NCOA4 (ferroptosis indicator) in hypoxic trophoblast cells. Lnc-HZ06 promoted the SUMOylation of HIF1α by suppressing SENP1-mediated deSUMOylation. HIF1α-SUMO also acted as a transcription factor to promote lnc-HZ06 transcription. Thus, both lnc-HZ06 and HIF1α-SUMO formed a positive auto-regulatory feedback loop. This loop was up-regulated in hypoxic trophoblast cells, in RM villous tissues, and in placental tissues of hypoxia-treated mice, which further induced ferroptosis and miscarriage by up-regulating HIF1α-SUMO-mediated NCOA4 transcription. Furthermore, knockdown of either murine lnc-hz06 or Ncoa4 could efficiently suppress ferroptosis and alleviate miscarriage in hypoxic mouse model. Taken together, this study provided new insights in understanding the regulatory roles of lnc-HZ06/HIF1α-SUMO/NCOA4 axis among hypoxia, ferroptosis, and miscarriage, and also offered an effective approach for treatment against miscarriage.

Occlusal Force Maintains Alveolar Bone Homeostasis via Type H Angiogenesis

Physiologically, teeth and periodontal tissues are exposed to occlusal forces throughout their lifetime. Following occlusal unloading, unbalanced bone remodeling manifests as a net alveolar bone (AB) loss. This phenomenon is termed alveolar bone disuse osteoporosis (ABDO), the underlying mechanism of which remains unclear. Type H vessels, a novel capillary subtype tightly coupled with osteogenesis, reportedly have a role in skeletal remodeling; however, their role in ABDO is not well studied. In the present study, we aimed to explore the pathogenesis of and therapies for ABDO. The study revealed that type H endothelium highly positive for CD31 and endomucin was identified in the periodontal ligament (PDL) but rarely in the AB of the mice. In hypofunctional PDL, the density of type H vasculature and coupled osterix+ (OSX+) osteoprogenitors declined significantly. In addition, the angiogenic factor Slit guidance ligand 3 (SLIT3) was downregulated in the disused PDL, and periodontal injection of the recombinant SLIT3 protein partially ameliorated type H vessel dysfunction and AB loss in ABDO mice. With regard to the molecular mechanism, a mechanosensory signaling circuit, PIEZO1/Ca2+/HIF-1α/SLIT3, was validated by applying cyclic compression to 3-dimensional-cultured PDL cells using the Flexcell FX-5000 compression system. In summary, PDL plays a pivotal role in mechanotransduction by translating physical forces into the intracellular signaling axis PIEZO1/Ca2+/HIF-1α/SLIT3, which promotes type H angiogenesis and OSX+ cell-related osteogenensis, thereby contributing to AB homeostasis. Our findings advance the understanding of PDL in AB disorders. Further therapies targeting SLIT3 may provide new insights into preventing bone loss in ABDO.

MiR-218-5p promotes trophoblast infiltration and inhibits endoplasmic reticulum/oxidative stress by reducing UBE3A-mediated degradation of SATB1

This research evaluated the effects of miR-218-5p on trophoblast infiltration and endoplasmic reticulum/oxidative stress during preeclampsia (PE). The expression of miR-218-5p and special AT-rich sequence binding protein 1 (SATB1) in placental tissues from 25 patients with PE and 25 normal pregnant subjects was determined using qRT-PCR and western blotting. Cell invasion and cell migration were detected by performing Transwell assays and scratch assays, respectively. MMP-2/9, TIMP1/2, HIF-1α, p-eIF2α, and ATF4 expression in cells was assessed through western blotting. Intracellular reactive oxygen species were detected using 2,7-dichlorodihydrofluorescein diacetate, and intracellular malondialdehyde and superoxide dismutase activities were determined with kits. Dual-luciferase and RNA pull-down assays were performed to verify the interaction between miR-218-5p and UBE3A. Co-immunoprecipitation and western blotting were used to detect the ubiquitination levels of SATB1. A rat model of PE was established, and an miR-218-5p agomir was injected into rat placental tissues. The pathological characteristics of placental tissues were detected via HE staining, and MMP-2/9, TIMP1/2, p-eIF2α, and ATF4 expression in rat placental tissues was determined through western blotting. MiR-218-5p and SATB1 were expressed at low levels, while UBE3A was highly expressed in the placental tissues of patients with PE. The transfection of an miR-218-5p mimic, UBE3A shRNA, or an SATB1 overexpression vector into HTR-8/SVneo cells promoted trophoblast infiltration and inhibited endoplasmic reticulum/oxidative stress. It was determined that UBE3A is a target of miR-218-5p; UBE3A induces ubiquitin-mediated degradation of SATB1. In PE model rats, miR-218-5p alleviated pathological features, promoted trophoblast infiltration, and inhibited endoplasmic reticulum/oxidative stress. MiR-218-5p targeted and negatively regulated UBE3A expression to inhibit ubiquitin-mediated SATB1 degradation, promote trophoblast infiltration, and inhibit endoplasmic reticulum/oxidative stress.

The effect of MicroRNAs variants on idiopathic recurrent pregnancy loss

BACKGROUND

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

METHODS AND RESULTS

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

CONCLUSION

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

The impact of early pregnancy metabolic disorders on pregnancy outcome and the specific mechanism

Miscarriage is the most common complication of pregnancy. The most common causes of early miscarriage are chromosomal abnormalities of the embryo, maternal endocrine abnormalities, organ malformations, and abnormal immune factors. Late miscarriages are mostly caused by factors such as cervical insufficiency. However, the causes of 50% of miscarriages remain unknown. Recently, increasing attention has been given to the role of metabolic abnormalities in miscarriage. In this review, we mainly discuss the roles of four major metabolic pathways (glucose, lipid, and amino acid metabolism, and oxidation‒reduction balance) in miscarriage and the metabolism-related genes that lead to metabolic disorders in miscarriage. Depending on aetiology, the current treatments for miscarriage include hormonal and immunological drugs, as well as surgery, while there are few therapies for metabolism. Therefore, we also summarize the drugs for metabolism-related targets. The study of altered metabolism underlying miscarriage not only helps us to understand the mechanisms involved in miscarriage but also provides an important basis for clinical research on new therapies.

miR‑424‑5p is downregulated in the placentas of patients with preeclampsia and affects trophoblast migration and invasion

Insufficient invasion of trophoblast cells has been reported to be closely associated with the pathogenesis of preeclampsia (PE). MicroRNAs (miRs) have essential roles in the trophoblasts invasion via targeting specific genes with diverse functions. However, the underlying mechanism remains largely unclear and requires further investigation. The present study aimed to identify and evaluate the potential functions of miRs in trophoblasts invasion and to reveal the underlying mechanisms. In the present study, differentially expressed miRs that were screened based on previously published microarray data (GSE96985) and a significantly downregulated miR-424-5p (miR-424) was chosen for further investigation. Subsequently, reverse transcription-quantitative PCR, CCK-8, apoptosis, wound healing and Transwell assays were performed to determine the cell viability, apoptotic rate, cell migration and invasion of trophoblast cells. The results showed that miR-424 was decreased in placenta specimens from patients with PE. Upregulation of miR-424 promoted cell viability, suppressed cell apoptosis and improved the invasion and migration of trophoblasts, whereas inhibition of miR-424 had opposite results. Adenomatous polyposis coli (APC), a key mediator of Wnt/β-catenin signaling pathway, was identified as a functional target of miR-424 and an inverse relationship was observed between APC and miR-424 in placenta specimens. Further investigations revealed that APC overexpression efficiently suppressed the effect of miR-424 in trophoblast cells. In addition, the miR-424-mediated effects on trophoblast cells were dependent on the promotion of Wnt/β-catenin signaling pathway. The present findings revealed that miR-424 regulates the trophoblast cell invasion by regulating Wnt/β-catenin pathway through targeting APC, indicating miR-424 as a potential candidate for the treatment of PE.

MiR-218-5p/EGFR Signaling in Arsenic-Induced Carcinogenesis

BACKGROUND

Arsenic is a well-known carcinogen inducing lung, skin, bladder, and liver cancer. Abnormal epidermal growth factor receptor (EGFR) expression is common in lung cancer; it is involved in cancer initiation, development, metastasis, and treatment resistance. However, the underlying mechanism for arsenic-inducing EGFR upregulation remains unclear.

METHODS

RT-PCR and immunoblotting assays were used to detect the levels of miR-218-5p and EGFR expression. The Luciferase assay was used to test the transcriptional activity of EGFR mediated by miR-218-5p. Cell proliferation, colony formation, wound healing, migration assays, tube formation assays, and tumor growth assays were used to study the function of miR-218-5p/EGFR signaling.

RESULTS

EGFR and miR-218-5p were dramatically upregulated and downregulated in arsenic-induced transformed (As-T) cells, respectively. MiR-218-5p acted as a tumor suppressor to inhibit cell proliferation, migration, colony formation, tube formation, tumor growth, and angiogenesis. Furthermore, miR-218-5p directly targeted EGFR by binding to its 3'-untranslated region (UTR). Finally, miR-218-5p exerted its antitumor effect by inhibiting its direct target, EGFR.

CONCLUSION

Our study highlights the vital role of the miR-218-5p/EGFR signaling pathway in arsenic-induced carcinogenesis and angiogenesis, which may be helpful for the treatment of lung cancer induced by chronic arsenic exposure in the future.

Tissue origin of circulating microRNAs and their response to nutritional and environmental stress in rainbow trout (Oncorhynchus mykiss)

Stresses associated with changes in diet or environmental disturbances are common situations that fish encounter during their lifetime. The stability and ease of measuring microRNAs (miRNAs) present in biological fluids make these molecules particularly interesting biomarkers for non-lethal assessment of stress in animals. Rainbow trout were exposed for four weeks to abiotic stress (moderate hypoxia) and/or nutritional stress (a high-carbohydrate/low-protein diet). Blood plasma and epidermal mucus were sampled at the end of the experiment, and miRNAs were assessed using small RNA sequencing. We identified four miRNAs (miR-122-5p, miR-184-3p, miR-192-5p and miR-194a-5p) and three miRNAs (miR-210-3p, miR-153a-3p and miR-218c-5p) that accumulated in response to stress in blood plasma and epidermal mucus, respectively. In particular, the abundance of miR-210-3p, a hypoxamiR in mammals, increased strongly in the epidermal mucus of rainbow trout subjected to moderate hypoxia, and can thus be considered a relevant biomarker of hypoxic stress in trout. We explored the contribution of 22 tissues/organs to the abundance of circulating miRNAs (c-miRNAs) in blood plasma and epidermal mucus influenced by the treatments. Some miRNAs were tissue-specific, while others were distributed among several tissues. Some c-miRNAs (e.g., miR-210-3p, miR184-3p) showed similar variations in both tissues and fluids, while others showed an inverse trend (e.g., miR-122-5p) or no apparent relationship (e.g. miR-192-5p, miR-194a-5p. Overall, these results demonstrate that c-miRNAs can be used as non-lethal biomarkers to study stress in fish. In particular, the upregulation of miR-210-3p in epidermal mucus induced by hypoxia demonstrates the potential of using epidermal mucus as a matrix for identifying non-invasive biomarkers of stress. This study provides information about the tissue sources of c-miRNAs and highlights the potential difficulty in relating variations in miRNA abundance in biological fluids to that in tissues.

LASP1 in Cellular Signaling and Gene Expression: More than Just a Cytoskeletal Regulator

LIM and SH3 protein 1 was originally identified as a structural cytoskeletal protein with scaffolding function. However, recent data suggest additional roles in cell signaling and gene expression, especially in tumor cells. These novel functions are primarily regulated by the site-specific phosphorylation of LASP1. This review will focus on specific phosphorylation-dependent interaction between LASP1 and cellular proteins that orchestrate primary tumor progression and metastasis. More specifically, we will describe the role of LASP1 in chemokine receptor, and PI3K/AKT signaling. We outline the nuclear role for LASP1 in terms of epigenetics and transcriptional regulation and modulation of oncogenic mRNA translation. Finally, newly identified roles for the cytoskeletal function of LASP1 next to its known canonical F-actin binding properties are included.

Dietary choline, via gut microbe- generated trimethylamine-N- oxide, aggravates chronic kidney disease-induced cardiac dysfunction by inhibiting hypoxia-induced factor 1α

Chronic kidney disease (CKD) is a global public health problem that shortens lifespan primarily by increasing the risk of cardiovascular diseases. Trimethylamine-N-oxide (TMAO), a gut microbiota-derived toxin produced by metabolizing high-choline or carnitine foods, is associated with cardiovascular events in patients with CKD. Although the deleterious effect of TMAO on CKD-induced cardiac injury has been confirmed by various researches, the mechanisms remain unclear. Here, we tested the hypothesis that TMAO aggravates CKD-induced cardiac injury and explores the potential mechanism. CD1 mice underwent 5/6 nephrectomy to induce CKD, and then fed with a diet supplemented with choline (1.2% total) for 8 weeks. Serum TMAO levels were elevated in CKD mice compared with SHAM group, and higher TMAO levels were found in choline-supplemented CKD mice compared with CKD group. Dietary choline aggravated CKD-induced cardiac dysfunction, and reducing TMAO levels via medicinal charcoal tablets improved cardiac dysfunction. RNA-seq analysis revealed that dietary choline affected cardiac angiogenesis in CKD mice. Reduced cardiac capillary density and expressions of angiogenesis-related genes were observed in choline-treated CKD mice. Furthermore, dietary choline inhibited cardiac Hif-1α protein level in CKD mice, and Hif-1α stabilizer FG-4592 could improve cardiac angiogenesis and dysfunction in CKD mice on a high-choline diet. In conclusion, these data indicate that dietary choline, via gut microbe-generated TMAO, inhibits cardiac angiogenesis by reducing Hif-1α protein level, ultimately aggravates cardiac dysfunction in CKD mice.

Role of microRNAs in trophoblast invasion and spiral artery remodeling: Implications for preeclampsia

It is now well-established that microRNAs (miRNAs) are important regulators of gene expression. The role of miRNAs in placental development and trophoblast function is constantly expanding. Trophoblast invasion and their ability to remodel uterine spiral arteries are essential for proper placental development and successful pregnancy outcome. Many miRNAs are reported to be dysregulated in pregnancy complications, especially preeclampsia and they exert various regulatory effects on trophoblasts. In this review, we provide a brief overview of miRNA biogenesis and their mechanism of action, as well as of trophoblasts differentiation, invasion and spiral artery remodeling. We then discuss the role of miRNAs in trophoblasts invasion and spiral artery remodeling, focusing on miRNAs that have been thoroughly investigated, especially using multiple model systems. We also discuss the potential role of miRNAs in the pathogenesis of preeclampsia.

Micro-RNAs in Human Placenta: Tiny Molecules, Immense Power

Micro-RNAs (miRNAs) are short non-coding single-stranded RNAs that modulate the expression of various target genes after transcription. The expression and distribution of kinds of miRNAs have been characterized in human placenta during different gestational stages. The identified miRNAs are recognized as key mediators in the regulation of placental development and in the maintenance of human pregnancy. Aberrant expression of miRNAs is associated with compromised pregnancies in humans, and dysregulation of those miRNAs contributes to the occurrence and development of related diseases during pregnancy, such as pre-eclampsia (PE), fetal growth restriction (FGR), gestational diabetes mellitus (GDM), recurrent miscarriage, preterm birth (PTB) and small-for-gestational-age (SGA). Thus, having a better understanding of the expression and functions of miRNAs in human placenta during pregnancy and thereby developing novel drugs targeting the miRNAs could be a potentially promising method in the prevention and treatment of relevant diseases in future. Here, we summarize the current knowledge of the expression pattern and function regulation of miRNAs in human placental development and related diseases.

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.

Triclosan activates c-Jun/miR-218-1-3p/SLC35C1 signaling to regulate cell viability, migration, invasion and inflammatory response of trophoblast cells in vitro

BACKGROUND

Spontaneous abortion is considered as the commonest complication of pregnancy. Triclosan (TCS) is an antimicrobial agent, which participates in the process of multiple human diseases, including spontaneous abortion. Our study aimed to evaluate the effect of TCS on spontaneous abortion and disclose the possible regulatory mechanism in vitro.

RESULTS

RT-qPCR analyzed that miR-218-1-3p derived from abortion-associated factor slit guidance ligand 2 (SLIT2) was up-regulated in trophoblast cells under TCS treatment. Supported by western blot analysis, functional experiments demonstrated that miR-218-1-3p overexpression impeded the proliferation, migration and invasion while exacerbating the inflammatory response of trophoblast cells. Moreover, mechanism assays revealed that TCS modulated c-Jun production to promote MIR218-1 transcription and enhance miR-218-1-3p expression. Moreover, solute carrier family 35 member C1 (SLC35C1) was validated as a target gene of miR-218-1-3p, and miR-218-1-3p was sustained to negatively modulate SLC35C1 expression in trophoblast cells. Rescue assays validated the role of TCS/miR-218-1-3p/SLC35C1 axis in regulating the viability, migration, invasion and inflammatory response of trophoblast cells.

CONCLUSIONS

TCS regulated miR-218-1-3p/SLC35C1 axis to modulate the proliferation, migration, invasion and inflammatory response of trophoblast cells in vitro, which might provide novel insights for spontaneous abortion prevention.

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.

A novel regulatory mechanism network mediated by lncRNA TUG1 that induces the impairment of spiral artery remodeling in Preeclampsia

Preeclampsia (PE) is associated with maternal and fetal perinatal morbidity and mortality, which brings tremendous suffering and imposes an economic burden worldwide. The failure of uterine spiral artery remodeling may be related to the abnormal function of trophoblasts and lead to the occurrence and progression of PE. Aberrant expression of long non-coding RNAs (lncRNAs) is involved in the failure of uterine spiral artery remodeling. However, the regulation of lncRNA expression in PE is poorly characterized. Here, we reported that hypoxia-induced microRNA (miR)-218 inhibited the expression of lncRNA TUG1 by targeting FOXP1. Further RNA sequencing and mechanism analysis revealed that silencing of TUG1 increased the expression of DNA demethylase TET3 and proliferation-related DUSP family, including DUSP2, DUSP4, and DUSP5, via binding to SUV39H1 in the nucleus. Moreover, TUG1 modulated the DUSP family in vitro through a TET3-mediated epigenetic mechanism. Taken together, our results unmask a new regulatory network mediated by TUG1 as an essential determinant of the pathogenesis of PE, which regulates cell growth and possibly the occurrence and development of other diseases.

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

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

LncRNA SNHG16 regulates trophoblast functions by the miR-218-5p/LASP1 axis

Altered placental development and function lead to placental diseases such as preeclampsia (PE) which is mainly characterized by insufficient trophoblast invasion and abnormally invasive placenta disorders. Long noncoding RNAs (lncRNAs) are widely reported to function as crucial players in the pathogenesis of PE. The present investigation clarified the role of lncRNA small nucleolar RNA host gene 16 (SNHG16) in PE. RT-qPCR was used to measure gene expression. The proliferation of trophoblast cells was examined using CCK-8 and EdU assays. Trophoblast migration and invasion were assessed using wound healing and transwell assays. The apoptosis was estimated by flow cytometry. Luciferase reporter and RNA pull-down assays were performed to explore the molecular mechanisms in trophoblast cells. We found that SNHG16 was downregulated in placenta from patients with PE. Moreover, SNHG16 depletion significantly inhibited trophoblast cell proliferation, migration, and invasion and stimulated apoptosis, while SNHG16 overexpression exerted an opposite effect. Subsequently, we confirmed that SNHG16 acted as a competing RNA (ceRNA) of miR-218-5p that was verified to directly target LASP1. Both miR-218-5p depletion and LASP1 upregulation antagonized the effect of SNHG16 knockdown on HTR-8/SVneo cell functions. In conclusion, SNHG16 facilitates trophoblast cell migration and invasion by the miR-218-5p/LASP1 axis.

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.

Information on dysregulation of microRNA in placenta linked to preeclampsia

MicroRNAs are single-stranded, non-coding RNA molecules, regulate gene expression at the post-transcriptional level. They are expressed in the human body and have a significant impact on the different processes of pathological illness. A developing placenta undergoes a series of stages after successful fertilization, such as cell division, migration, adhesion, apoptosis, and angiogenesis. MicroRNAs dysregulation in placenta has been linked to pregnancy-related complications such as preeclampsia. Therefore, it is of interest to document known information (list of microRNA) on this issue in the development of biological tools for diagnosis, treatment and prevention of the disease.

Hypoxia-induced SPOP attenuates the mobility of trophoblast cells through inhibition of the PI3K/AKT/GSK3β pathway

Placental hypoxia has been implicated in pregnancy pathologies such as pre-eclampsia and intrauterine growth restriction. However, the underlying mechanism by which the trophoblasts respond to hypoxia remains unclear. Speckle-type POZ protein (SPOP), an E3 ubiquitin ligase adapter, was previously reported to play important roles in various physiological and pathological processes. This study aims to investigate the expression and biological functions of SPOP after exposure to cobalt chloride (CoCl₂ )-mimicked hypoxia conditions using human trophoblast-derived choriocarcinoma cell lines and extravillous cytotrophoblast. These data showed that SPOP protein was directly induced by CoCl₂ -mimicked hypoxia and regulated by HIF-1α at the posttranscription level. CoCl₂ treatment could dramatically influence the localization of SPOP in trophoblasts, especially the accumulation of SPOP into the nucleus. In addition, both CoCl₂ -mimicked hypoxia and induction of endogenous SPOP expression by lentivirus transfection attenuated the migration and invasion abilities of trophoblasts. Furthermore, we demonstrated that SPOP was involved in CoCl₂ -induced the inhibition of the PI3K/AKT/GSK3β pathway in placental trophoblasts. Taken together, these data indicate that accumulation of HIF-1α augments the expression of SPOP in trophoblasts, which impairs trophoblastic mobility by targeting the PI3K/AKT/GSK3β pathway. This potentially leads to insufficient uterine spiral artery remodeling and suboptimal placental perfusion, and thus the development of pregnancy-related complication.

Adaptations of the human placenta to hypoxia: opportunities for interventions in fetal growth restriction

BACKGROUND

The placenta is the functional interface between the mother and the fetus during pregnancy, and a critical determinant of fetal growth and life-long health. In the first trimester, it develops under a low-oxygen environment, which is essential for the conceptus who has little defense against reactive oxygen species produced during oxidative metabolism. However, failure of invasive trophoblasts to sufficiently remodel uterine arteries toward dilated vessels by the end of the first trimester can lead to reduced/intermittent blood flow, persistent hypoxia and oxidative stress in the placenta with consequences for fetal growth. Fetal growth restriction (FGR) is observed in ∼10% of pregnancies and is frequently seen in association with other pregnancy complications, such as preeclampsia (PE). FGR is one of the main challenges for obstetricians and pediatricians, as smaller fetuses have greater perinatal risks of morbidity and mortality and postnatal risks of neurodevelopmental and cardio-metabolic disorders.

OBJECTIVE AND RATIONALE

The aim of this review was to examine the importance of placental responses to changing oxygen environments during abnormal pregnancy in terms of cellular, molecular and functional changes in order to highlight new therapeutic pathways, and to pinpoint approaches aimed at enhancing oxygen supply and/or mitigating oxidative stress in the placenta as a mean of optimizing fetal growth.

SEARCH METHODS

An extensive online search of peer-reviewed articles using PubMed was performed with combinations of search terms including pregnancy, placenta, trophoblast, oxygen, hypoxia, high altitude, FGR and PE (last updated in May 2020).

OUTCOMES

Trophoblast differentiation and placental establishment are governed by oxygen availability/hypoxia in early pregnancy. The placental response to late gestational hypoxia includes changes in syncytialization, mitochondrial functions, endoplasmic reticulum stress, hormone production, nutrient handling and angiogenic factor secretion. The nature of these changes depends on the extent of hypoxia, with some responses appearing adaptive and others appearing detrimental to the placental support of fetal growth. Emerging approaches that aim to increase placental oxygen supply and/or reduce the impacts of excessive oxidative stress are promising for their potential to prevent/treat FGR.

WIDER IMPLICATIONS

There are many risks and challenges of intervening during pregnancy that must be considered. The establishment of human trophoblast stem cell lines and organoids will allow further mechanistic studies of the effects of hypoxia and may lead to advanced screening of drugs for use in pregnancies complicated by placental insufficiency/hypoxia. Since no treatments are currently available, a better understanding of placental adaptations to hypoxia would help to develop therapies or repurpose drugs to optimize placental function and fetal growth, with life-long benefits to human health.

H3K4me3-Mediated Upregulation of LncRNA-HEIPP in Preeclampsia Placenta Affects Invasion of Trophoblast Cells

Preeclampsia (PE) is a pregnancy-related disease defined as onset of hypertension and proteinuria after the 20th week of pregnancy, which causes most maternal and perinatal morbidity and mortality. Although placental dysfunction is considered as the main cause of PE, the exact pathogenesis of PE is not yet fully understood. Long non-coding RNAs (lncRNAs) are implicated in a broad range of physiological and pathological processes, including the occurrence of PE. In this study, we investigated the expression and functions of HIF-1α pathway-related lncRNA-HEIPP (high expression in PE placenta) in the pathogenesis of PE. The expression of lncRNA-HEIPP in the placenta from women who underwent PE was screened by lncRNA microarray and then verified using real-time polymerase chain reaction. Then, the methylation profile of the lncRNA-HEIPP promoter and the enrichment of H3K4me3 binding were assessed by bisulfite pyrosequencing and chromatin immunoprecipitation (ChIP)-quantitative polymerase chain reaction (qPCR) assay, respectively. It was found that the level of lncRNA-HEIPP in the PE placenta was significantly higher than that in normal placenta and was increased in HTR-8/SVneo human trophoblast cells upon hypoxia treatment. Moreover, we reported that H3K4me3 manifested significantly higher promoter occupancy on lncRNA-HEIPP promoter in HTR-8/SVneo cells upon hypoxia treatment and found that the downregulation of lncRNA-HEIPP promoted trophoblast invasion. Our findings suggested that the hypoxia-induced expression of lncRNA-HEIPP mediated by H3K4me3 modification in trophoblast may contribute to the pathogenesis of PE.

Expression levels of maternal plasma microRNAs in preeclamptic pregnancies

The present study aimed to identify the differential expression profiles of microRNAs in the plasma between patients with preeclampsia (PE) and healthy pregnancies using quantitative real-time PCR. The expression profiles of 32 miRNAs in maternal plasma from 31 patients with PE and 32 healthy pregnancies were evaluated. The expression levels of eight miRNAs including miR-210, miR-375, miR-197-3p, miR-132-3p, miR-29a-3p, miR-328, miR-24-3p, and miR-218-5p were significantly upregulated and the expression levels of three miRNAs, including miR-302b-3p, miR-191-5p, and miR-17-5p, were significantly downregulated in patients with preeclampsia when compared to healthy pregnant women. In conclusion, we identified 11 miRNAs that may be potential biomarkers for non-invasive diagnosis and a pivotal role in the prediction of PE. Considering the small cohort of patients, further studies with larger samples from different gestational stages are necessary to confirm our findings.IMPACT STATEMENTWhat is already known on this subject? The alterations in the release pattern of placenta-specific miRNAs detected in maternal serum have been found to be associated with pregnancy-related complications such as preeclampsia (PE).What do the results of this study add? In the present study, the release pattern of seven miRNAs had consistency and two of them had inconsistency with previous researches. Moreover, two novel miRNAs were also defined to demonstrate the interrelationship between PE and miRNAs.What are the implications of these findings for clinical practice and/or future research? The identification of 11 miRNAs that may be potential biomarkers for non-invasive diagnosis and a pivotal role in the prediction of PE. Considering the small cohort of patients, further studies with larger samples from different gestational stages are necessary to confirm our findings.

Up-regulated microRNA-218-5p ameliorates the damage of dopaminergic neurons in rats with Parkinson's disease via suppression of LASP1

OBJECTIVE

Parkinson's disease (PD) is a frequent degenerative disease of the nervous system with undefined pathogenesis. This study explored the protective effect of microRNA (miR)-218-5p on dopaminergic neuron injury in substantia nigra (SN) of rats with PD through the regulation of LIM and SH3 domain protein 1 (LASP1).

METHODS

The PD rat model was established by fixed point injection of 6-hydroxydopamine into the rats. The PD rats were injected with miR-218-5p overexpressed recombinant adeno-associated virus (rAAV) or LASP1 silenced rAAV to explore their roles in dopaminergic neurons in SN of rats with PD. The changes in pathological structure of SN were observed and the expression of tyrosine hydroxylase (TH) and deacetylvindoline acetyltransferase (DAT), the dopaminergic neuron apoptosis and oxidative stress factor in the SN were detected. The expression of miR-218-5p, LASP1, Bcl-2 and Bax in SN was detected. The targeting relationship between miR-218-5p and LASP1 was confirmed.

RESULTS

Declined miR-218-5p and overexpressed LASP1 existed in the brain SN of PD rats. Up-regulated miR-218-5p or inhibited LASP1 improved the pathological damage of dopaminergic neurons and increased the number of TH and DAT positive cells in brain SN of PD rats. Furthermore, elevated miR-218-5p or depressed LASP1 inhibited the apoptosis, and oxidative stress of dopaminergic neurons in brain SN of PD rats. In addition, increased miR-218-5p repressed the expression of LASP1 in the brain SN of PD rats. LASP1 was proven to be a direct target of miR-218-5p.

CONCLUSION

The study highlights that up-regulated miR-218-5p could improve the damage of dopaminergic neurons in PD rats, which was related to the inhibition of LASP1.

MicroRNA‑491‑5p inhibits trophoblast cell migration and invasion through targeting matrix metalloproteinase‑9 in preeclampsia

Insufficient invasion of trophoblasts is correlated with the development of preeclampsia (PE). MicroRNA (miR)-491-5p has been reported to be implicated in human cancer cell invasion; however, whether miR-491-5p is involved in the development of PE remains largely unclear. The aim of the present study was to investigate the role of miR-491-5p in trophoblastic invasion in vitro and to determine its underlying mechanism of action. The expression levels of miR-491-5p were validated using reverse transcription-quantitative PCR. The effects of miR-491-5p on trophoblast cell invasion were evaluated in vitro. Then, the association between miR-491-5p and its downstream target was investigated in both cell lines and clinical specimens. miR-491-5p expression levels were observed to be significantly increased in the placental tissues from patients with PE. The invasive capacity of HTR-8/SVneo trophoblast cells was suppressed following the upregulation of miR-491-5p and increased following the inhibition of miR-491-5p. Matrix metalloproteinase-9 (MMP-9), a well-known regulator of trophoblast cell invasion, was discovered to be a direct target of miR-491-5p in HTR-8/SVneo trophoblast cells. Moreover, miR-491-5p expression levels were found to be inversely correlated with MMP-9 expression levels in placental tissues from patients with PE. The overexpression of MMP-9 partly attenuated the inhibitory effects of miR-491-5p on HTR-8/SVneo trophoblast cells invasion. Collectively, these findings suggested that the aberrant expression of miR-491-5p may contribute to PE through suppressing trophoblast invasion, thus highlighting the novel roles of miR-491-5p in the molecular pathogenesis of PE. The present study also showed that the miR-491-5p/MMP-9 axis may be an effective biomarker or a viable drug target for therapeutic intervention in PE.

miR-218 Expressed in Endothelial Progenitor Cells Contributes to the Development and Repair of the Kidney Microvasculature

Ischemia due to hypoperfusion is one of the most common forms of acute kidney injury. We hypothesized that kidney hypoxia initiates the up-regulation of miR-218 expression in endothelial progenitor cells (EPCs) to guide endocapillary repair. Murine renal artery-derived EPCs (CD34+/CD105-) showed down-regulation of mmu-Mir218-5p/U6 RNA ratio after ischemic injury, while in human renal arteries, MIR218-5p expression was up-regulated after ischemic injury. MIR218 expression was clarified in cell culture experiments in which increases in both SLIT3 and MIR218-2-5p expressions were observed after 5 minutes of hypoxia. ROBO1 transcript, a downstream target of MIR218-2-5p, showed inverse expression to MIR218-2-5p. EPCs transfected with a MIR218-5p inhibitor in three-dimensional normoxic culture showed premature capillary formation. Organized progenitor cell movement was reconstituted when cells were co-transfected with Dicer siRNA and low-dose Mir218-5p mimic. A Mir218-2 knockout was generated to assess the significance of miR-218-2 in a mammalian model. Mir218-2-5p expression was decreased in Mir218-2-/- embryos at E16.5. Mir218-2-/- decreased CD34+ angioblasts in the ureteric bud at E16.5 and were nonviable. Mir218-2+/- decreased peritubular capillary density at postnatal day 14 and increased serum creatinine after ischemia in adult mice. Systemic injection of miR-218-5p decreased serum creatinine after injury. These experiments demonstrate that miR-218 expression can be triggered by hypoxia and modulates EPC migration in the kidney.

miR-215-5p decreases migration and invasion of trophoblast cells through regulating CDC6 in preeclampsia

Preeclampsia (PE) is a serious disease that occurs after 20 weeks during pregnancy. There are some aberrant microRNAs (miRNAs) that are associated with the etiology of PE. As discovered by scholars, there was an increased level of miR-215-5p in plasma of PE patients compared with the control group; nonetheless, there is still no knowledge of the mechanism of miR-215-5p in PE. We carried out the comparison of the expression levels of miR-215-5p, and the supposed target gene cell division cycle 6 (CDC6) in 30 placentas from PE patients as well as 30 placentas from normal pregnant women. The verification of the impacts of miR-215-5p and CDC6 was carried out by functional assays in HTR-8/SVneo cells transfected with the miR-215-5p mimic or siR-CDC6. As indicated by findings, miR-215-5p showed an apparent increase; conversely, CDC6 was inhibited in the experiment group. The upregulation of miR-215-5p inhibited both the migration and invasive potential of trophoblasts, besides decreasing the G1-S transition and downregulating CDC6 in HTR-8/SVneo cells; nonetheless, it did not significantly impact the cell proliferation. Furthermore, siR-CDC6 replicated the functions of the miR-215-5p mimic. Also, the miR-215-5p mimic and siR-CDC6 both decreased the epithelial-mesenchymal transition (EMT) with additional E-cadherin level and decreased the expressions of N-cadherin as well as vimentin in trophoblast cells. To conclude, miR-215-5p decreased not only the migration but also the invasion of trophoblasts through regulating CDC6, which indicated that miR-215-5p might be associated with the etiology of PE. SIGNIFICANCE OF THE STUDY: More and more attention has been paid on the roles of miRNAs in the pathogenesis of PE. However, there is no study of miR-215-5p in the etiology of PE. We first investigated the mechanism of miR-215-5p in placental tissues and HTR-8/SVneo cells. It was suggested that miR-215-5p decreased the abilities of migration and invasion of trophoblasts through regulating CDC6 in PE. miR-215-5p might be used as an target for the early diagnosis and treatment of PE in the future.

MicroRNAs in Uteroplacental Vascular Dysfunction

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

ANLN-induced EZH2 upregulation promotes pancreatic cancer progression by mediating miR-218-5p/LASP1 signaling axis

Background

Pancreatic cancer is a highly lethal malignancy with poor prognosis. Anillin (ANLN), an actin binding protein, is upregulated and plays an important role in many malignant tumors. However, the precise role of ANLN in pancreatic cancer remains unclear.

Methods

The expression of ANLN and its association with pancreatic cancer patient survival were analyzed using an online database and confirmed by immunohistochemistry. The ANLN protein expression in pancreatic cancer cell lines was detected by Western blot. Cell proliferation, colony formation and transwell assays in vitro and in vivo tumor growth were used to determine the role of ANLN in pancreatic cancer. Gene expression microarray analysis and a series of in vitro assays were used to elucidate the mechanisms of ANLN regulating pancreatic cancer progression.

Results

We found that the ANLN expression was significantly upregulated in pancreatic cancer tissues and cell lines. The high expression of ANLN was associated with tumor size, tumor differentiation, TNM stage, lymph node metastasis, distant metastasis and poor prognosis in pancreatic cancer. ANLN downregulation significantly inhibited cell proliferation, colony formation, migration, invasion and tumorigenicity in nude mice. Meanwhile, we found that ANLN knockdown inhibited several cell-cell adhesion related genes, including the gene encoding LIM and SH3 protein 1 (LASP1). LASP1 upregulation partially reversed the tumor-suppressive effect of ANLN downregulation on pancreatic cancer cell progression. Moreover, we found that ANLN downregulation induced the expression of miR-218-5p which inhibited LASP1 expression through binding to its 3’UTR. We also found that ANLN-induced enhancer of zeste homolog 2 (EZH2) upregulation was involved in regulating miR-218-5p/LASP1 signaling axis. EZH2 upregulation or miR-218-5p downregulation partially reversed the tumor-suppressive effect of ANLN downregulation on pancreatic cancer cell progression.

Conclusion

ANLN contributed to pancreatic cancer progression by regulating EZH2/miR-218-5p/LASP1 signaling axis. These findings suggest that ANLN may be a candidate therapeutic target in pancreatic cancer.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1340-7) contains supplementary material, which is available to authorized users.

Hypoxia-induced Downregulation of SRC-3 Suppresses Trophoblastic Invasion and Migration Through Inhibition of the AKT/mTOR Pathway: Implications for the Pathogenesis of Preeclampsia

Preeclampsia (PE) is characterized by poor placentation, consequent on aberrant extravillous trophoblast (EVT) cell function during placental development. The SRC family of proteins is important during pregnancy, especially SRC-3, which regulates placental morphogenesis and embryo survival. Although SRC-3 expression in mouse trophoblast giant cells has been documented, its role in the functional regulation of extravillous trophoblasts and the development of PE remains unknown. This study found that SRC-3 expression was significantly lower in placentas from PE pregnancies as compared to uncomplicated pregnancies. Additionally, both CoCl₂-mimicked hypoxia and suppression of endogenous SRC-3 expression by lentivirus short hairpin RNA attenuated the migration and invasion abilities of HTR-8/SVneo cells. Moreover, we demonstrated that SRC-3 physically interacts with AKT to regulate the migration and invasion of HTR-8 cells, via the AKT/mTOR pathway. We also found that the inhibition of HTR-8 cell migration and invasion by CoCl₂-mimicked hypoxia was through the SRC-3/AKT/mTOR axis. Our findings indicate that, in early gestation, accumulation of HIF-1α inhibits the expression of SRC-3, which impairs extravillous trophoblastic invasion and migration by directly interacting with AKT. This potentially leads to insufficient uterine spiral artery remodeling and placental hypoperfusion, and thus the development of PE.

Regulatory mechanisms of Robo4 and their effects on angiogenesis

Roundabout4 (Robo4) is a transmembrane receptor that belongs to the Roundabout (Robo) family of axon guidance molecules. Robo4 is an endothelial-specific receptor that participates in endothelial cell migration, proliferation, and angiogenesis and the maintenance of vasculature homeostasis. The purpose of this review is to summarize and analyze three main mechanisms related to the expression and function of Robo4 during developmental and pathological angiogenesis. In this review, static shear stress and the binding of transcription factors such as E26 transformation-specific variant 2 (ETV2) and Slit3 induce Robo4 expression and activate Robo4 during tissue and organ development. Robo4 interacts with Slit2 or UNC5B to maintain vascular integrity, while a disturbed flow and the expression of transcription factors in inflammatory or neoplastic environments alter Robo4 expression levels, although these changes have uncertain functions. Based on the mechanisms described above, we discuss the aberrant expression of Robo4 in angiogenesis-related diseases and propose antiangiogenic therapies targeting the Robo4 signaling pathway for the treatment of ocular neovascularization lesions and tumors. Finally, although many problems related to Robo4 signaling pathways remain to be resolved, Robo4 is a promising and potentially valuable therapeutic target for treating pathological angiogenesis and developmental defects in angiogenesis.

Risk of spontaneous preterm birth and fetal growth associates with fetal SLIT2

Spontaneous preterm birth (SPTB) is the leading cause of neonatal death and morbidity worldwide. Both maternal and fetal genetic factors likely contribute to SPTB. We performed a genome-wide association study (GWAS) on a population of Finnish origin that included 247 infants with SPTB (gestational age [GA] < 36 weeks) and 419 term controls (GA 38-41 weeks). The strongest signal came within the gene encoding slit guidance ligand 2 (SLIT2; rs116461311, minor allele frequency 0.05, p = 1.6×10-6). Pathway analysis revealed the top-ranking pathway was axon guidance, which includes SLIT2. In 172 very preterm-born infants (GA <32 weeks), rs116461311 was clearly overrepresented (odds ratio 4.06, p = 1.55×10-7). SLIT2 variants were associated with SPTB in another European population that comprised 260 very preterm infants and 9,630 controls. To gain functional insight, we used immunohistochemistry to visualize SLIT2 and its receptor ROBO1 in placentas from spontaneous preterm and term births. Both SLIT2 and ROBO1 were located in villous and decidual trophoblasts of embryonic origin. Based on qRT-PCR, the mRNA levels of SLIT2 and ROBO1 were higher in the basal plate of SPTB placentas compared to those from term or elective preterm deliveries. In addition, in spontaneous term and preterm births, placental SLIT2 expression was correlated with variations in fetal growth. Knockdown of ROBO1 in trophoblast-derived HTR8/SVneo cells by siRNA indicated that it regulate expression of several pregnancy-specific beta-1-glycoprotein (PSG) genes and genes involved in inflammation. Our results show that the fetal SLIT2 variant and both SLIT2 and ROBO1 expression in placenta and trophoblast cells may be correlated with susceptibility to SPTB. SLIT2-ROBO1 signaling was linked with regulation of genes involved in inflammation, PSG genes, decidualization and fetal growth. We propose that this receptor-ligand couple is a component of the signaling network that promotes SPTB.

Down-regulation of microRNA-34a-5p promotes trophoblast cell migration and invasion via targetting Smad4

Trophoblastic dysfunction, such as insufficient migration and invasion, is well-known to be correlated with preeclampsia (PE). Recently, microRNAs (miRNAs) have been implicated in diverse biological processes and human diseases, including PE. However, the expression and functions of miRNAs in the progression of PE, especially in the regulation of trophoblast cell migration and invasion remain largely unclear. Here, we compared the miRNAs expression profiles of PE patients with healthy controls using microarray assay and chose a significant increased miRNA-miR-34a-5p for further investigation. Overexpression of miR-34a-5p dramatically reduced migration and invasion in trophoblast HTR-8/SVneo cells, whereas enhanced by its inhibitor. Luciferase activity assay showed that miR-34a-5p directly target Smad family member 4 (Smad4), which is associated with cancer cell invasiveness and metastasis. We also found that Smad4 was down-regulated in PE patients, and an inverse relationship between Smad4 and miR-34a-5p expression levels was observed in placental tissues from PE patients. Further study showed that knockdown of Smad4 effectively attenuated the promoting effects of miR-34a-5p inhibition on the migration and invasion of HTR-8/SVneo cells. Taken together, these findings suggest that inhibition of miR-34a-5p improves invasion and migration of trophoblast cells by directly targetting Smad4, which indicated the potential of miR-34a-5p as a therapeutic target against PE.

A potential regulatory network among WDR86-AS1, miR-10b-3p, and LITAF is possibly involved in preeclampsia pathogenesis

Preeclampsia (PE), a pregnancy-specific disorder, is a leading cause of perinatal maternal and fetal mortality and morbidity. Impaired migration and invasion of trophoblastic cells and an imbalanced systemic maternal inflammatory response have been proposed as possible causes of pathogenesis of PE. Comparative analysis of PE-affected placentas and healthy placentas has uncovered differentially expressed long noncoding RNAs, microRNAs, and mRNAs. This study was conducted to investigate the effect of a regulatory network among these RNAs on PE pathogenesis. Long noncoding RNA WDR86-AS1, microRNA miR-10b-3p, and mRNA of protein LITAF were identified by screening of genes in existing databases with aberrant expression in PE-affected placentas and potential mutual interactions as revealed by TargetScan, miRanda, and PicTar analyses. This study identified their expression in PE-affected and healthy placentas by RT-PCR. An in vitro experiment was performed on human trophoblast HTR-8/SVneo cells cultured under normoxic or hypoxic conditions. MiR-10b-3p targets were identified in luciferase reporter assays and RNA pull-down assays. The mouse model of PE was set up using a soluble form of FLT-1 for in vivo testing. Lower levels of miR-10b-3p but higher expression of WDR86-AS1 and LITAF were observed in PE-affected placentas and trophoblast cells under hypoxia. WDR86-AS1 and LITAF mRNA were confirmed as targets of miR-10b-3p. WDR86-AS1 downregulated miR-10b-3p but promoted LITAF expression. Microarray analyses revealed that LITAF controlled the inflammatory responses and migration and proliferation of HTR-8/SVneo cells under hypoxia. Indeed, knockdown of WDR86-AS1 and LITAF or overexpression of miR-10b-3p attenuated the hypoxia-induced inhibition of cellular viability, migration, and invasion. Moreover, miR-10b-3p overexpression attenuated the pathological symptoms caused by soluble FLT-1 in vivo. In summary, the WDR86-AS1/miR-10b-3p/LITAF network is probably involved in PE pathogenesis.

New Frontiers for the Cytoskeletal Protein LASP1

In the recent two decades, LIM and SH3 protein 1 (LASP1) has been developed from a simple actin-binding structural protein to a tumor biomarker and subsequently to a complex, nuclear transcriptional regulator. Starting with a brief historical perspective, this review will mainly compare and contrast LASP1 and LASP2 from the angle of the newest data and importantly, examine their role in transcriptional regulation. We will summarize the current knowledge through pictorial models and tables including the roles of different microRNAs in the differential regulation of LASP1 levels and patient outcome rather than specify in detail all tumor entities. Finally, the novel functional roles of LASP1 in secretion of vesicles, expression of matrix metalloproteinases and transcriptional regulation as well as the activation of survival and proliferation pathways in different cancer types are described.

Tumor necrosis factor-alpha suppresses the invasion of HTR-8/SVneo trophoblast cells through microRNA-145-5p-mediated downregulation of Cyr61

Deficiency in trophoblast invasion is causally linked to the pathogenesis of preeclampsia. Tumor necrosis factor-alpha (TNF-α) shows the ability to suppress the invasiveness of trophoblasts, while cysteine-rich 61 (Cyr61) exerts an opposite function in trophoblast invasion. This study was designed to check the hypothesis that cysteine-rich 61 (Cyr61) may be involved in the anti-invasive activity of TNF-α in trophoblasts. To this end, we examined the effect of TNF-α treatment on Cyr61 expression in HTR-8/SVneo trophoblast cells and investigated the mechanism for the regulation of Cyr61 by TNF-α. Gain-of-function experiments were performed to clarify the role of Cyr61 in TNF-α-dependent suppression of trophoblast invasion. It was found that TNF-α at 1 and 10 ng/mL reduced Cyr61 protein levels by 30 and 80%, respectively, in HTR-8/SVneo cells, but did not affect the mRNA expression of Cyr61. Mechanistically, microRNA (miR)-145-5p was stimulated by TNF-α and negatively regulated the expression of Cyr61 via interaction with its 3'-untranslated region. Functionally, overexpression of miR-145-5p significantly impaired the migration and invasion of HTR-8/SVneo cells. Depletion of miR-145-5p rescued HTR-8/SVneo cells from TNF-α-mediated invasion suppression, which coincided with prevention of Cyr61 downregulation by TNF-α. In addition, overexpression of Cyr61 partially restored the invasion of HTR8/SVneo cells co-transfected with miR-145-5p mimic or exposed to TNF-α. Taken together, miR-145-5p-mediated downregulation of Cyr61 is required for the anti-invasive effect of TNF-α on trophoblasts.

Human circular RNA‑0054633 regulates high glucose‑induced vascular endothelial cell dysfunction through the microRNA‑218/roundabout 1 and microRNA‑218/heme oxygenase‑1 axes

The aim of the present study was to investigate the relative regulation of human circular RNA‑0054633 (hsa_circ_0054633), microRNA‑218 (miR‑218), roundabout 1 (ROBO1) and heme oxygenase‑1 (HO‑1) in human umbilical vein endothelial cells (HUVECs) in high glucose conditions. Initially, the expression of hsa_circ_0054633 in HUVECs was detected in high glucose conditions by reverse transcription‑quantitative polymerase chain reaction. Next, a small interfering RNA against hsa_circ_0054633 was constructed to investigate the function of jsa_circ_0054633 in HUVECs by transwell migration, cell counting kit‑8, flow cytometry and tube formation assays. In addition, the effect of hsa_circ_0054633 on the expression levels of ROBO1, HO‑1 and vascular endothelial growth factor were examined. The regulation effects of hsa_circ_0054633 on high glucose‑induced HUVEC proliferation, migration, and angiopoiesis were also analyzed. Bioinformatics analysis and dual‑luciferase assay were then used to confirm the direct or specific regulation of hsa_circ_0054633, miR‑218, ROBO1 and HO‑1. It was observed that high glucose levels increased the expression of hsa_circ_0054633, while downregulation of hsa_circRNA‑0054633 increased the high glucose‑induced endothelial cell dysfunction, including proliferation, migration and angiopoiesis suppression. Bioinformatics analysis revealed that the expression of circRNA‑0054633 was able to inhibit miR‑218 expression, which was clarified by the dual‑luciferase assay. It was also demonstrated that downregulating the expression of miR‑218 inhibited the high glucose‑induced endothelial cell dysfunction by promoting the expression of ROBO1 and HO‑1. These results suggest that the expression of hsa_circRNA‑0054633 has a protective effect against high glucose‑induced endothelial cell dysfunction by targeting ROBO1 and HO‑1.