Differential miR-346 and miR-582-3p Expression in Association with Selected Maternal and Fetal Complications

Circulating biomarkers associated with placental dysfunction and their utility for predicting fetal growth restriction

Fetal growth restriction (FGR) leading to low birth weight (LBW) is a major cause of neonatal morbidity and mortality worldwide. Normal placental development involves a series of highly regulated processes involving a multitude of hormones, transcription factors, and cell lineages. Failure to achieve this leads to placental dysfunction and related placental diseases such as pre-clampsia and FGR. Early recognition of at-risk pregnancies is important because careful maternal and fetal surveillance can potentially prevent adverse maternal and perinatal outcomes by judicious pregnancy surveillance and careful timing of birth. Given the association between a variety of circulating maternal biomarkers, adverse pregnancy, and perinatal outcomes, screening tests based on these biomarkers, incorporating maternal characteristics, fetal biophysical or circulatory variables have been developed. However, their clinical utility has yet to be proven. Of the current biomarkers, placental growth factor and soluble fms-like tyrosine kinase 1 appear to have the most promise for placental dysfunction and predictive utility for FGR.

Circulating Non-coding RNAs and Exosomes: Liquid Biopsies for Monitoring Preeclampsia

Preeclampsia (PE) remains a leading cause of maternal and fetal mortality, due to ineffective treatment and diagnostic strategies, compounded by the lack of clarity on the etiology of the disorder. The early prediction or accurate diagnosis of PE is a concern of researchers. Liquid biopsy can be analyzed for cell-free nucleic acids and exosomes. Because circulating non-coding RNAs (ncRNAs) and peripheral blood exosomes can be detected in the peripheral blood of women in early pregnancy, these vesicles and their contents have become the focus of research on early predictive and diagnostic biomarkers for preeclampsia. In this review, we focus on recent studies addressing the roles of circulating ncRNAs and exosomes in PE, with particular attention paid to the potential application value of placenta-derived exosomes and circulating ncRNAs as PE-specific biomarkers.

Diagnostic value of serum miR-25-3p in hypertensive disorders in pregnancy

Hypertensive disorders in pregnancy (HDIP) represent one of the leading causes of maternal and perinatal mortality. microRNA (miR)-25-3p plays roles in HDIP diagnosis. We explored miR-25-3p clinical roles in HDIP. HDIP patients [gestation hypertension (GH), mild preeclampsia (mPE), and severe preeclampsia (sPEz)], and normal pregnant women serving as the control were enrolled. Serum miR-25-3p expression patterns were detected by RT-qPCR. The diagnostic efficacy of miR-25-3p on HDIP was analyzed with a ROC curve. Patients were assigned to the high/low miR-25-3p expression groups according to the median value of miR-25-3p expression. All patients were followed up until delivery, and gestational weeks and pregnancy outcomes were recorded at delivery. The effects of miR-25-3p expression on pregnancy outcomes of GH, mPE, and sPEz patients were analyzed by Kaplan-Meier. miR-25-3p expression in GH, mPE, and sPEz patients was up-regulated. In sPEz patients, systolic and diastolic blood pressure, 24-h urine protein, AST, ALT, GGT, and SCr were increased, and PLT was decreased in the high expression group. High miR-25-3p expression was associated with an increased risk of adverse pregnancy outcomes in PE patients. Collectively, high miR-25-3p expression could aid HDIP diagnosis, and associated with an increased risk of adverse pregnancy outcomes in PE patients.

microRNA signatures associated with fetal growth restriction: a systematic review

Placental-origin microRNA (miRNA) profiles can be useful toward early diagnosis and management of fetal growth restriction (FGR) and associated complications. We conducted a systematic review to identify case-control studies that have examined miRNA signatures associated with human FGR. We systematically searched PubMed and ScienceDirect databases for relevant articles and manually searched reference lists of the relevant articles till May 18th, 2021. Of the 2133 studies identified, 21 were included. FGR-associated upregulation of miR-210 and miR-424 and downregulation of a placenta-specific miRNA cluster miRNA located on C19MC (miR-518b, miR-519d) and miR-221-3p was reported by >1 included studies. Analysis of the target genes of these miRNA as well as pathway analysis pointed to the involvement of angiogenesis and growth signaling pathways, such as the phosphatidylinositol 3-kinase- protein kinase B (PI3K-Akt) pathway. Only 3 out of the 21 included studies reported FGR-associated miRNAs in matched placental and maternal blood samples. We conclude that FGR-associated placental miRNAs could be utilized to inform clinical practice towards early diagnosis of FGR, provided enough evidence from studies on matched placental and maternal blood samples become available.Prospective Register of Systematic Reviews (PROSPERO) registration number: CRD42019136762.

Sporadic Alzheimer's Disease- and Neurotoxicity-Related microRNAs Affecting Key Events of Tau-Driven Adverse Outcome Pathway Toward Memory Loss

BACKGROUND

A complex network of aging-related homeostatic pathways that are sensitive to further deterioration in the presence of genetic, systemic, and environmental risk factors, and lifestyle, is implicated in the pathogenesis of progressive neurodegenerative diseases, such as sporadic (late-onset) Alzheimer's disease (sAD).

OBJECTIVE

Since sAD pathology and neurotoxicity share microRNAs (miRs) regulating common as well as overlapping pathological processes, environmental neurotoxic compounds are hypothesized to exert a risk for sAD initiation and progression.

METHODS

Literature search for miRs associated with human sAD and environmental neurotoxic compounds was conducted. Functional miR analysis using PathDip was performed to create miR-target interaction networks.

RESULTS

The identified miRs were successfully linked to the hypothetical starting point and key events of the earlier proposed tau-driven adverse outcome pathway toward memory loss. Functional miR analysis confirmed most of the findings retrieved from literature and revealed some interesting findings. The analysis identified 40 miRs involved in both sAD and neurotoxicity that dysregulated processes governing the plausible adverse outcome pathway for memory loss.

CONCLUSION

Creating miR-target interaction networks related to pathological processes involved in sAD initiation and progression, and environmental chemical-induced neurotoxicity, respectively, provided overlapping miR-target interaction networks. This overlap offered an opportunity to create an alternative picture of the mechanisms underlying sAD initiation and early progression. Looking at initiation and progression of sAD from this new angle may open for new biomarkers and novel drug targets for sAD before the appearance of the first clinical symptoms.

Effects of maternal diet-induced obesity on metabolic disorders and age-associated miRNA expression in the liver of male mouse offspring

OBJECTIVE

This study investigated the effect of maternal obesity on aged-male offspring liver phenotype and hepatic expression of a programmed miRNA.

METHODS

A mouse model (C57BL/6 J) of maternal diet-induced obesity was used to investigate fasting-serum metabolites, hepatic lipid content, steatosis, and relative mRNA levels (RT-PCR) and protein expression (Western blotting) of key components involved in hepatic and mitochondrial metabolism in 12-month-old offspring. We also measured hepatic lipid peroxidation, mitochondrial content, fibrosis stage, and apoptosis in the offspring. To investigate potential mechanisms leading to the observed phenotype, we also measured the expression of miR-582 (a miRNA previously implicated in liver cirrhosis) in 8-week-old and 12-month-old offspring.

RESULTS

Body weight and composition was similar between 8-week-old offspring, however, 12-month-old offspring from obese mothers had increased body weight and fat mass (19.5 ± 0.8 g versus 10.4 ± 0.9 g, p < 0.001), as well as elevated serum levels of LDL and leptin and hepatic lipid content (21.4 ± 2.1 g versus 12.9 ± 1.8 g, p < 0.01). This was accompanied by steatosis, increased Bax/Bcl-2 ratio, and overexpression of p-SAPK/JNK, Tgfβ1, Map3k14, and Col1a1 in the liver. Decreased levels of Bcl-2, p-AMPKα, total AMPKα and mitochondrial complexes were also observed. Maternal obesity was associated with increased hepatic miR-582-3p (p < 0.001) and miR-582-5p (p < 0.05). Age was also associated with an increase in both miR-582-3p and miR-582-5p, however, this was more pronounced in the offspring of obese dams, such that differences were greater in 12-month-old animals (-3p: 7.34 ± 1.35 versus 1.39 ± 0.50, p < 0.0001 and -5p: 4.66 ± 1.16 versus 1.63 ± 0.65, p < 0.05).

CONCLUSION

Our findings demonstrate that maternal diet-induced obesity has detrimental effects on offspring body composition as well as hepatic phenotype that may be indicative of accelerated-ageing phenotype. These whole-body and cellular phenotypes were associated with age-dependent changes in expression of miRNA-582 that might contribute mechanistically to the development of metabolic disorders in the older progeny.

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.

CircHIPK3 contributes to human villous trophoblast growth, migration and invasion via modulating the pathway of miR-346/KCMF1

INTRODUCTION

Preeclampsia (PE) is one of the leading causes of maternal and perinatal morbidity and mortality worldwide. The regular growth, migration and invasion of villous trophoblast cells contribute to placental development. The objective of this study was to investigate the role and mechanism of circular RNA homeodomain interacting protein kinase 3 (circHIPK3) in the biological functions of trophoblast cells.

METHODS

The expression of circHIPK3, microRNA-346 (miR-346) and potassium channel modulatory factor 1 (KCMF1) mRNA was measured by quantitative real-time PCR (qPCR). Trophoblast cell proliferation, migration/invasion and cell cycle progression/apoptosis were determined by CCK-8 assay, transwell assay and flow cytometry assay, respectively. The predicted relationship between miR-346 and circHIPK3 or KCMF1 by bioinformatics was confirmed dual-luciferase reporter assay and RIP assay.

RESULTS

CircHIPK3 and KCMF1 were downregulated, while miR-346 was upregulated in placenta tissues from PE patients. The forced expression of circHIPK3 promoted trophoblast cell proliferation and migration/invasion but alleviated cell cycle arrest and cell apoptosis. MiR-346 was a target of circHIPK3, and miR-346 restoration reversed the effects of circHIPK3 upregulation. In addition, circHIPK3 acted as miR-346 sponge to modulate KCMF1 expression. KCMF1 downregulation partially repressed trophoblast cell proliferation, migration and invasion that were facilitated by miR-346 inhibition or circHIPK3 upregulation.

DISCUSSION

CircHIPK3 contributes to trophoblast cell proliferation, migration and invasion by upregulating KCMF1 via acting as miR-346 sponge.

High-throughput miRNA sequencing of the human placenta: expression throughout gestation

Aim: To understand miRNA changes across gestation in healthy human placentae. This is essential before miRNAs can be used as biomarkers or prognostic indicators during pregnancy. Materials & methods: Using next-generation sequencing, we characterize the normative human placenta miRNome in first (n = 113) and third trimester (n = 47). Results & conclusion: There are 801 miRNAs expressed in both first and third trimester, including 182 with similar expression across gestation (p ≥ 0.05, fold change ≤2) and 180 significantly different (false discovery rate <0.05, fold change >2). Of placenta-specific miRNA clusters, chromosome 14 miRNA cluster decreases across gestation and chromosome 19 miRNA cluster is overall highly expressed. Chromosome 13 clusters are upregulated in first trimester. This work provides a rich atlas of healthy pregnancies to direct functional studies investigating the epigenetic differences in first and third trimester placentae.

Hsa_circ_0074371 Regulates Proliferation, Apoptosis, Migration, and Invasion via the miR-582-3p/LRP6 Axis in Trophoblast Cells

Fetal growth restriction (FGR) ranks second among causes of perinatal death. Circular RNA hsa_circ_0074371 (hsa_circ_0074371) is reported to be downregulated in FGR placentae. However, the role and regulatory mechanism of hsa_circ_0074371 in FGR pathogenesis are indistinct. Expression of hsa_circ_0074371, microRNA (miR)-582-3p, and low-density lipoprotein receptor-related protein 6 (LRP6) mRNA in FGR placentae and trophoblast cells (HTR-8/SVneo) was detected by quantitative real-time polymerase chain reaction (qRT-PCR). The relationship between hsa_circ_0074371 or LRP6 and miR-582-3p was verified by dual-luciferase reporter and/or RNA immunoprecipitation (RIP), RNA pull-down assays. The proliferation, cell cycle progression, apoptosis, migration, and invasion of HTR-8/SVneo cells were evaluated by Cell Counting Kit-8 (CCK-8), flow cytometry, wound healing, or transwell assays. Caspase3 activity was analyzed with a commercial kit. The protein levels of c-myc, cyclinD1, matrix metalloproteinase (MMP) 2, MMP9, and LRP6 were examined by western blotting. We observed that hsa_circ_0074371 and LRP6 were downregulated while miR-582-3p was upregulated in FGR placentae and HTR-8/SVneo cells. Hsa_circ_0074371 modulated LRP6 expression via sponging miR-582-3p. Hsa_circ_0074371 knockdown induced cell cycle arrest, apoptosis, and inhibited cell proliferation, migration, and invasion in HTR-8/SVneo cells. MiR-582-3p inhibitor reversed hsa_circ_0074371 silencing me on proliferation, migration, and invasion of HTR-8/SVneo cells. LRP6 overexpression overturned the inhibitory effect of miR-582-3p mimic on proliferation, migration, and invasion of HTR-8/SVneo cells. In conclusion, hsa_circ_0074371 downregulation inhibited proliferation, migration, and invasion of trophoblast cells via sponging miR-582-3p and decreasing LRP6 expression, providing a new mechanism related to FGR pathogenesis.

Potential biomarker enhancing the activity of tuberculosis, hsa-miR-346

OBJECTIVES

To determine the usefulness of hsa-miR-346, a potential biomarker enhancing the activity of non-tuberculous mycobacterial diseases, as a biomarker of tuberculosis activity.

METHODS

We investigated whether hsa-miR-346 is secreted by human macrophages infected with Mycobacterium tuberculosis (M. tuberculosis) in an in vitro study. In addition, a cross-sectional study was conducted first to evaluate whether serum hsa-miR-346 is elevated in patients with tuberculosis compared with that in healthy individuals. Second, we conducted a retrospective study to evaluate whether anti-tuberculosis treatment reduces serum hsa-miR-346 levels.

RESULTS

Log hsa-miR-346 levels were significantly elevated in the supernatant of human macrophages infected with M. tuberculosis in a dose-dependent manner. The mean serum log hsa-miR-346 levels were -15.48 (-15.76 to -15.21) in patients with tuberculosis and -16.12 (-16.29 to -15.95) in healthy volunteers, which significantly differed. In addition, hsa-miR-346 significantly decreased at 2 months from starting an anti-tuberculosis treatment.

CONCLUSIONS

We consider hsa-miR-346 as a potential biomarker enhancing the tuberculosis activity.

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.

MicroRNA-346-5p Regulates Differentiation of Bone Marrow-Derived Mesenchymal Stem Cells by Inhibiting Transmembrane Protein 9

The molecular mechanisms how bone marrow-derived mesenchymal stem cells (BMSCs) differentiate into osteoblast need to be investigated. MicroRNAs (miRNAs) contribute to the osteogenic differentiation of BMSCs. However, the effect of miR-346-5p on osteogenic differentiation of BMSCs is not clear. This study is aimed at elucidating the underlying mechanism by which miR-346-5p regulates osteogenic differentiation of human BMSCs. Results of alkaline phosphatase (ALP) and Alizarin Red S (ARS) staining indicated that upregulation of miR-346-5p suppressed osteogenic differentiation of BMSCs, whereas downregulation of miR-346-5p enhanced this process. The protein levels of the osteoblastic markers Osterix and Runt-related transcription factor 2 (Runx2) were decreased in cells treated with miR-346-5p mimic at day 7 and day 14 after being differentiated. By contrast, downregulation of miR-346-5p elevated the protein levels of Osterix and Runx2. Moreover, a dual-luciferase reporter assay revealed that Transmembrane Protein 9 (TMEM9) was a target of miR-346-5p. In addition, the Western Blot results demonstrated that the TMEM9 protein level was significantly reduced by the miR-346-5p mimic whereas downregulation of miR-346-5p improved the protein level of TMEM9. These results together demonstrated that miR-346-5p served a key role in BMSC osteogenic differentiation of through targeting TMEM9, which may provide a novel target for clinical treatments of bone injury.

Pregnancy immune tolerance at the maternal-fetal interface

Pregnancy is a natural process that poses an immunological challenge because non-self fetus must be accepted. During the pregnancy period, the fetus as 'allograft' inherits maternal and also paternal antigens. For successful and term pregnancy, the fetus is tolerated and nurtured enjoying immune privileges that minimize the risk of being rejected by maternal immune system. Multiple mechanisms contribute to tolerate the semi-allogeneic fetus. Here, we summarize the recent progresses on how the maternal immune system actively collaborates to maintain the immune balance and maternal-fetal tolerance.

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.

Elevated miR-200a and miR-141 inhibit endocrine gland-derived vascular endothelial growth factor expression and ciliogenesis in preeclampsia

KEY POINTS

Endocrine gland-derived vascular endothelial growth factor (EG-VEGF) is a critical factor that facilitates trophoblast invasion in placenta. Plasma miR-141 and miR-200a levels were elevated, while EG-VEGF was decreased in peripheral blood and placenta of preeclamptic patients. Furthermore, numbers of cilia in the placenta from preeclamptic women were significantly decreased. Elevated miR-141 and miR-200a inhibited the expression of EG-VEGF, downstream extracellular signal-regulated kinase (ERK)/matrix metalloproteinase 9 signalling and cilia formation, thus leading to defective trophoblast invasion. The growth of the primary cilium, which transduced ERK signalling upon EG-VEGF induction for proper trophoblast invasion, was also inhibited by miR-141 and miR-200a upregulation.

ABSTRACT

Preeclampsia is a severe gestational complication, and inadequate trophoblast invasion during placental development is an important pathoaetiology. Endocrine gland-derived vascular endothelial growth factor (EG-VEGF) is a critical factor that facilitates trophoblast invasion in placenta. By binding to the primary cilium, EG-VEGF initiates the signalling cascade for proper embryo implantation and placental development. The miR-200 family was predicted to target the EG-VEGF 5'-untranslated region, and its specific binding site was confirmed using a dual luciferase and a co-transfection assay. In the peripheral blood and placenta of preeclamptic patients, EG-VEGF showed significantly lower expression, whereas plasma miR-141 and miR-200a had higher expression compared with the controls. The biological significance of miR-141 and miR-200a was verified using an overexpression method in a trophoblast cell line (HTR-8/SVneo). Elevated miR-141 and miR-200a inhibited the expression of EG-VEGF, matrix metalloproteinase 9 (MMP9) and downstream extracellular signal-regulated kinase (ERK) signalling, thus leading to defective trophoblast invasion. Additionally, the growth of the primary cilium, which transduces ERK/MMP9 signalling upon EG-VEGF induction, was inhibited by miR-141 and miR-200a upregulation. Furthermore, the number of cilia in the human placenta of preeclamptic women was significantly decreased compared to normal placenta. In conclusion, the study uncovers the clinical correlations among the miR-200 family, EG-VEGF and the primary cilium in preeclampsia and the underlying molecular mechanisms. The results indicate that miR-141 and miR-200a directly targeted EG-VEGF, suppressed primary cilia formation and inhibited trophoblast invasion. Thus, miR-141 and miR-200a could be explored as promising miRNA biomarkers and therapeutic targets in preeclampsia.

Trimester-specific plasma exosome microRNA expression profiles in preeclampsia

Objective: To identify microRNAs (miRNAs) differentially expressed in plasma exosomes collected in women diagnosed with preeclampsia compared with women with uncomplicated pregnancies.Materials and methods: Exosomes were purified from plasma samples obtained at each trimester from four women subsequently diagnosed with preeclampsia and from five matched healthy controls. RNA was purified from the exosomes, and expression of 368 miRNAs was profiled using A-Set TaqMan low density array (TLDA).Results: One-third of the 368 miRNAs profiled are not expressed in exosomes. Further, those that are not expressed tend to be evolutionarily younger and have a significantly different mature sequence signature than do miRNAs that are expressed in exosomes. Among miRNAs that are expressed in exosomes, a total of eight (miR-134, miR-196b, miR-302c, miR-346, miR-376c, miR-486-3p, miR-590-5p, and miR-618) were found to display statistically significant differential expression between women who developed preeclampsia as compared with those who did not. Moreover, half of these miRNAs (miR-134, miR-376c, miR-486-3p, and miR-590-5p) displayed statistically significant differential expression in the first trimester.Conclusions: Not all miRNAs are expressed in exosomes. Those that tend to be evolutionarily older and have a significantly different mature sequence signature than those that are not. A few exosome-expressed miRNAs do display expression patterns in women subsequently diagnosed with preeclampsia that are significantly different than in women having an uncomplicated and, among these, several appear in the first trimester. These miRNAs are potential early markers of preeclampsia risk.