Non-Coding RNAs Regulate Placental Trophoblast Function and Participate in Recurrent Abortion

CircDDX21 alleviates trophoblast dysfunction and Treg differentiation in recurrent spontaneous abortion via miR-520a-5p/ FOXP3/PD-L1 axis

BACKGROUND

Recurrent spontaneous abortion (RSA) is a common complication during pregnancy, which is a burden to patients both physically and mentally. Circular RNAs (circRNAs) play important roles in RSA. However, the roles of circDDX21 in RSA development remain unknown.

METHODS

Decidual samples were harvested from healthy pregnant women and RSA patients. In HTR-8/SVneo and Bewo trophoblast cells, proliferation and migration were analyzed by cell counting kit-8 (CCK-8)/5-ethynyl-2'-deoxyuridine (EdU) staining and transwell/wound healing assays, respectively. CD4+ T cells from peripheral blood mononuclear cells of patients were incubated with trophoblast-conditioned medium. Regulatory T cells (Treg) proliferation was detected by carboxyfluorescein succinimidyl ester (CFSE) assay. Treg proportion, Treg/T helper 17 cells (Th17) ratio, and cytokines were measured using flow cytometry. The association among genes was validated using dual-luciferase assay, RNA immunoprecipitation (RIP), and chromatin immunoprecipitation (ChIP).

RESULTS

CircDDX21 and Forkhead box P3 (FOXP3) decreased, while miR-520a-5p increased in the decidual tissues of RSA patients. CircDDX21 overexpression promoted trophoblast proliferation and migration, and facilitated CD4+ T cell differentiation into Treg. CircDDX21 targeted miR-520a-5p to elevate FOXP3. MiR-520a-5p overexpression reversed the promoted trophoblast cell function of circDDX21 overexpression in HTR-8/SVneo cells. FOXP3 overexpression reversed the repressed trophoblast cell function elicited by miR-520a-5p overexpression in HTR-8/SVneo cells. FOXP3 promoted Treg differentiation by transcriptionally upregulating programmed cell death ligand 1 (PD-L1).

CONCLUSION

CircDDX21 ameliorated trophoblast dysfunction and Treg differentiation in RSA via miR-520a-5p/FOXP3/PD-L1 axis.

Quercetin promotes the proliferation, migration, and invasion of trophoblast cells by regulating the miR-149-3p/AKT1 axis

Recurrent spontaneous abortion (RSA) has a complex pathogenesis with an increasing prevalence and is one of the most intractable clinical challenges in the field of reproductive medicine. Quercetin (QCT) is an effective active ingredient extracted from Semen Cuscutae and Herba Taxilli used in traditional Chinese medicine for tonifyng the kidneys and promoting fetal restoration. Although QCT helps improve adverse pregnancy outcomes, the specific mechanism remains unclear. The trophoblast cell line HTR-8/SVneo cultured in vitro was treated with different concentrations of QCT, and the cell counting kit-8 assay, wound healing assay, transwell assay, and western blotting were used to evaluate the effects and mechanisms of QCT on the proliferation, migration, and invasion of HTR-8/SVneo cells, respectively. To assess the expression levels of miR-149-3p and AKT serine/threonine kinase 1 (AKT1), quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting analysis were performed. A dual-luciferase reporter assay was used to investigate the potential regulatory relationship between miR-149-3p and AKT1. Our results showed that QCT promoted the proliferation, migration, and invasion of trophoblast cells, promoted the expression of MMP2, MMP9, and vimentin, and downregulated the expression of E-cadherin. Mechanistically, QCT downregulated the expression of miR-149-3p and upregulated the expression of AKT1, and miR-149-3p directly targets AKT1, negatively regulating its expression. Overexpression of miR-149-3p and silencing of AKT1 counteracted the promotional effects of QCT on trophoblast proliferation, migration, and invasion. Taken together, QCT regulates the migration and invasion abilities of HTR-8/SVneo cells through the miR-149-3p/AKT1 axis, which may provide a promising therapeutic approach for RSA.

Biomarkers and diagnostic significance of non-coding RNAs in extracellular vesicles of pathologic pregnancy

Intercellular communication is an important mechanism for the development and maintenance of normal biological processes in all organs, including the female reproductive system. Extracellular vesicles, as important carriers of intercellular communication, contain a variety of biologically active molecules, such as mRNAs, miRNAs, lncRNAs, and circRNAs, which are involved in cell-to-cell exchanges as well as in many physiological and pathological processes in the body. Compared with biomarkers found in tissues or body fluids, extracellular vesicles show better stability due to the presence of their envelope membrane which prevents the degradation of the RNA message in their vesicles. Therefore, the genomic and proteomic information contained in extracellular vesicles can serve as important markers and potential therapeutic targets for female reproductive system-related diseases or placental function. Moreover, changes in the expression of non-coding RNAs (mainly miRNAs, lncRNAs, and circRNAs) in maternal extracellular vesicles can accurately and promptly reflect the progress of female reproductive system diseases. The aim of this review is to collect information on different types of non-coding RNAs with key molecular carriers in female pathologic pregnancies (preeclampsia and recurrent spontaneous abortion), so as to explore the relevant molecular mechanisms in female pathologic pregnancies and provide a theoretical basis for clinical research on the pathogenesis and therapeutic approaches of reproductive system diseases. The current state of the art of exosome isolation and extraction is also summarized.

Association between Mir-499, Mir-27a, and Mir-146a polymorphisms and their susceptibility to recurrent spontaneous abortion; in silico analysis

Objective

Recurrent spontaneous abortion (RSA) is defined as two or more pregnancy losses before 24 gestational weeks, accounting for 1-3% of fertile couples. A vast majority of single-nucleotide polymorphisms (SNPs) in some microRNA (miRNA) genes can change the miRNA-mRNA interaction and are associated with the risk of RSA. This study was designed to better elucidate the association between miR-27a, miR-499, and miR-146a polymorphisms and RSA risk.

Materials and Methods

SNP genotyping of miR-27a (rs895819), miR-499 (rs3746444), and miR-146a (rs2910164) was performed using polymerase chain reaction (PCR)-restriction fragment length polymorphism and tetra amplification-refractory mutation system PCR in 98 patients with RSA and 105 healthy subjects.

Results

Our results showed that the miR-499 rs3746444 and miR-27a rs895819 polymorphisms were significantly associated with RSA risk, whereas no significant differences were observed between the rs2910164 polymorphism and RSA susceptibility.

Conclusion

We proposed that the miR-499 rs3746444 and miR-27a rs895819 polymorphisms were correlated with RSA in our population, but the miR-146a rs2910164 variant was not associated with the risk of RSA.

Association of Genetic Polymorphisms in Long Noncoding RNA HOTTIP with Risk of Idiopathic Recurrent Spontaneous Abortion

The clustered homeobox gene family known as the Hox family plays a fundamental role in the morphogenesis of the vertebrate's embryo. A long noncoding RNA (lncRNA), known as HOTTIP (HOXA transcript at the distal tip), has been functionally characterized and contributed to the pathogenesis of various conditions. The current case-control study was undertaken to examine the gene frequencies and shared alleles of the HOTTIP  gene in Iranian participants with or without idiopathic recurrent spontaneous abortion (RSA). Both ARMS-PCR reaction and RFLP-PCR techniques were employed to detect three HOTTIP polymorphisms (rs2023843C/T, rs78248039A/T, and rs1859168C/A) in a DNA sample of 161 women with RSA and 177 healthy women. We found that the TT genotype of the HOTTIP rs2023843 C/T polymorphism was associated with a lower risk for idiopathic RSA. In contrast, the TT genotype of the HOTTIP rs78248039 A/T polymorphism was correlated with an enhanced risk of RSA. The presence of the A-allele for HOTTIP rs1859168 C/A polymorphism was associated with an increased risk for idiopathic RSA. Haplotype analysis showed that the T/T/A, C/T/A, T/T/C, and T/A/A haplotypes of rs2023843/rs78248039/rs1859168 enhanced RSA susceptibility. Computational analysis predicted that this lncRNA might act as a potential sponge for some microRNAs; therefore, affecting the expression of genes being targeted by them. In addition, both rs2023843 and rs1859168 variants could alter the local secondary structure of HOTTIP. Our results showed that HOTTIP rs2023843C/T, rs78248039A/T, and rs1859168C/A polymorphisms may confer genetic susceptibility to idiopathic RSA in an Iranian population.

Comparison of the gene expression profiles of endometrial and trophoblastic cells in women with recurrent miscarriage: A bioinformatics approach

Background

Recurrent miscarriage (RM) remains unsolved in > 50% of patients and causes physical and psychological problems in women without specific risk factors for miscarriage. For a successful pregnancy, acceptance of the endometrium and invasion of trophoblast cells into the endometrium is necessary.

Objective

This study aimed to use computational analysis to identify key genes and related pathways in endometrial and trophoblast cells derived from RM samples.

Materials and Methods

In this bioinformatics study, we explored the differential expression of genes in endometrial and trophoblast cells by analyzing the GSE165004 and GSE76862 datasets, respectively with the limma package in R software. Subsequently, overlapped genes between 2 datasets were selected, gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses were performed. The overlapped genes were integrated to construct a protein-protein interaction network and hub genes selection.

Results

We observed 41 overlapped genes between endometrial and trophoblast cells, and future analysis was accomplished in overlapped and nonoverlapped genes. Kyoto Encyclopedia of Genes and Genomes analysis indicated that overlapped genes were significantly enriched in the complement and coagulation cascades, pluripotency of stem cells, and synthesis and degradation of ketone bodies. Gene ontology analysis suggested that the genes were enriched in the cell cycle, apoptosis, and cell division. The top 10 genes included: IRS1, FGF2, MAPK6, MAPK1, MAPK3, MAPK8, MAPK9, PLK1, PRKACA, and PRKCA were identified from the PPI network.

Conclusion

This study identified the key genes and potential molecular pathways underlying the development of RM. This could provide novel insights to determine the possible mechanisms and interventional strategies associated with miscarriage.

A critical review of the recent concept of regulatory performance of DNA Methylations, and DNA methyltransferase enzymes alongside the induction of immune microenvironment elements in recurrent pregnancy loss

Recurrent pregnancy Loss (RPL)is a frequent and upsetting condition. Besides the prevalent cause of RPL including chromosomal defects in the embryo,the effect of translational elements like alterations of epigenetics are of great importance. The emergence of epigenetics has offered a fresh outlook on the causes and treatment of RPL by focusing on the examination of DNA methylation. RPL may arise as a result of aberrant DNA methylation of imprinted genes, placenta-specific genes, immune-related genes, and sperm DNA, which may have a direct or indirect impact on embryo implantation, growth, and development. Moreover, the distinct immunological tolerogenic milieu established at the interface between the mother and fetus plays a crucial role in sustaining pregnancy. Given this, there has been a great deal of interest in the regulation of DNA methylation and alterations in the cellular components of the maternal-fetal immunological milieu. The research on DNA methylation's role in RPL incidence and the control of the mother-fetal immunological milieu is summed up in this review.

PRDM14 extinction enables the initiation of trophoblast stem cell formation

Trophoblast stem cells (TSCs) can be chemically converted from embryonic stem cells (ESCs) in vitro. Although several transcription factors (TFs) have been recognized as essential for TSC formation, it remains unclear how differentiation cues link elimination of stemness with the establishment of TSC identity. Here, we show that PRDM14, a critical pluripotent circuitry component, is reduced during the formation of TSCs. The reduction is further shown to be due to the activation of Wnt/β-catenin signaling. The extinction of PRDM14 results in the erasure of H3K27me3 marks and chromatin opening in the gene loci of TSC TFs, including GATA3 and TFAP2C, which enables their expression and thus the initiation of the TSC formation process. Accordingly, PRDM14 reduction is proposed here as a critical event that couples elimination of stemness with the initiation of TSC formation. The present study provides novel insights into how induction signals initiate TSC formation.

Non-coding RNA regulates the immune microenvironment in recurrent spontaneous abortion (RSA): new insights into immune mechanisms†

Recurrent spontaneous abortion (RSA) has various causes, including chromosomal abnormalities, prethrombotic state, and abnormal uterine anatomical factors. However, the pathogenesis of RSA is still unclear. Surprisingly, non-coding RNA can stably express at the maternal-fetal interface and regulate immune cells' proliferation, apoptosis, invasion, metastasis, and angiogenesis. Accumulating evidence suggests that the competing endogenous RNA (ceRNA) regulatory network between non-coding RNAs complicates RSA's pathological process and maybe a new starting point for exploring RSA. In this review, we mainly discuss the regulatory network and potential significance of non-coding RNA in the immune microenvironment of RSA patients. In addition, the cellular interactions of non-coding RNA transported through vesicles were introduced from aspects of trophoblast function and immune regulation. Finally, we analyze previous studies and further discuss that the stable expression of non-coding RNA may be used as a biomarker of some disease states and a prediction target of RSA.

Biogenesis and function of exosome lncRNAs and their role in female pathological pregnancy

Preeclampsia, gestational diabetes mellitus, and recurrent spontaneous abortion are common maternal pregnancy complications that seriously endanger women's lives and health, and their occurrence is increasing year after year with a rejuvenation trend. In contrast to biomarkers found freely in tissues or body fluids, exosomes exist in a relatively independent environment and provide a higher level of stability. As backbone molecules, guidance molecules, and signaling molecules in the nucleus, lncRNAs can regulate gene expression. In the cytoplasm, lncRNAs can influence gene expression levels by modifying mRNA stability, acting as competitive endogenous RNAs to bind miRNAs, and so on. Exosomal lncRNAs can exist indefinitely and are important in intercellular communication and signal transduction. Changes in maternal serum exosome lncRNA expression can accurately and timely reflect the progression and regression of pregnancy-related diseases. The purpose of this paper is to provide a reference for clinical research on the pathogenesis, diagnosis, and treatment methods of pregnancy-related diseases by reviewing the role of exosome lncRNAs in female pathological pregnancy and related molecular mechanisms.

Identification of biomarkers and sex differences in the placenta of fetal growth restriction

AIM

Fetal growth restriction (FGR) can lead to short-term and long-term impairments in the fetus. The placenta functions as an exchanger for substance transport, playing a critical role in fetal growth. However, the mechanism from the placental standpoint is still not fully understood. In this study, we aimed to investigate the pathophysiological mechanisms in the placenta that mediated the development of FGR and sex differences.

METHODS

We analyzed the gene expression profiles of GSE100415 containing specific normotensive FGR placental samples and GSE114691 with canonical samples using three different methods, differentially expressed gene analysis, weighted gene co-expression network analysis, and gene set enrichment analysis. Gene enrichment was performed, including the gene ontology and pathway from the Kyoto Encyclopedia of Genes and Genomes. The important process was then validated in pregnant Wistar rats subcutaneously administered dexamethasone (0.2 mg/kg/d) or saline from gestation Day 9 to 21.

RESULTS

Our results revealed little difference between the comparison of normal and normotensive FGR placental samples but confirmed the sex difference. Further analyses of the canonical samples identified the occurrence of vascular dysfunction, which was validated by the calculation of the vascular lumen area, showing that the vascular lumen in the FGR group was more than in the control. We also discovered 17 significantly expressed genes from the involved eigengenes.

CONCLUSION

Our study provides an important theoretical and experimental basis to reevaluate the development of FGR from the placental standpoint and suggests a series of biomarkers for future clinical use.

Functional Roles of lncRNAs in Recurrent Pregnancy Loss: A Review Study

Recurrent pregnancy loss (RPL) or recurrent miscarriage is the failure of pregnancy before 20-24 weeks that influences around 2-5% of couples. Several genetic, immunological, environmental and physical factors may influence RPL. Although various traditional methods have been used to treat post-implantation failures, identifying the mechanisms underlying RPL may improve an effective treatment. Recent evidence suggested that gene expression alterations presented essential roles in the occurrence of RPL. It has been found that long non-coding RNAs (lncRNAs) play functional roles in pregnancy pathologies, such as recurrent miscarriage. lncRNAs can function as dynamic scaffolds, modulate chromatin function, guide and bind to microRNAs (miRNAs) or transcription factors. lncRNAs, by targeting various miRNAs and mRNAs, play essential roles in the progression or suppression of RPL. Therefore, targeting lncRNAs and their downstream targets might be a suitable strategy for diagnosis and treatment of RPL. In this review, we summarized emerging roles of several lncRNAs in stimulation or suppression of RPL.

Shoutai Wan Improves Embryo Survival by Regulating Aerobic Glycolysis of Trophoblast Cells in a Mouse Model of Recurrent Spontaneous Abortion

Background

During embryo implantation, the blastocyst exhibits a high capacity for aerobic glycolysis, which results in a unique microenvironment of high lactate/low pH at the maternal-fetal interface. Shoutai Wan (STW) is an effective Chinese herbal formula widely used in the clinical treatment of recurrent spontaneous abortion (RSA). However, the specific molecular mechanism by which STW prevents abortion is yet to be elucidated.

Methods

Female CBA/J mice were allocated into six groups randomly and then mated with BALB/c mice as the control group, DBA/2 mice as the RSA model, CBA/J×DBA/2 mice treated with dydrogesterone as the DQYT group, or CBA/J×DBA/2 mice treated with low, medium, and high-dose STW as the STW-L, STW-M, and STW-H groups, respectively. Drug administration started 14 days before mating and ended on the 14^th day of pregnancy. The embryo loss rate of each group was calculated on day 14 of gestation, and the pregnancy outcomes of the mice in each group were observed. The mouse serum was collected to determine the levels of progesterone (P) and chorionic gonadotropin (CG). The activities of HK2, PKM2, and LDHA, the key glycolytic enzymes in each group, were detected. The expressions of lactate, ATP, HK2, PKM2, LDHA, MCT4, GLUT1, and GPR81 as well as the morphology of trophoblast cells were examined.

Results

The embryo loss rate and adverse pregnancy outcomes were significantly increased (P < 0.05) in the RSA model group. After dydrogesterone or different doses of STW treatment, the embryo loss rate and adverse pregnancy outcomes were rescued to varying degrees (P < 0.05). Interestingly, there was no significant difference among the groups in terms of serum P and CG (P < 0.05). Moreover, the activities of key glycolytic enzymes, lactate, ATP, HK2, PKM2, LDHA, MCT4, GLUT1, GPR81 protein or mRNA expression, and morphological abnormalities of trophoblast cells improved significantly in the RSA mice after dydrogesterone or different doses of STW treatment (P < 0.05).

Conclusion

STW can promote aerobic glycolysis in trophoblast cells of RSA mouse embryos, thereby improving the microenvironment of the maternal-fetal interface and enhancing embryo implantation.

Integrative analysis of circulating microRNAs and the placental transcriptome in recurrent pregnancy loss

Recurrent pregnancy loss (RPL) is a major type of pathological pregnancy that still lacks reliable early diagnosis and effective treatment. The placenta is critical to fetal development and pregnancy success because it participates in critical processes such as early embryo implantation, vascular remodeling, and immunological tolerance. RPL is associated with abnormalities in the biological behavior of placental villous trophoblasts, resulting in aberrant placental function. MicroRNAs (miRNAs) are increasingly being recognized as essential regulators of placental development, as well as potential biomarkers. In this study, plasma miRNAs and placental messenger RNAs (mRNAs) from RPL patients and normal pregnant (NP) controls were sequenced and analyzed. Compared to those in NP controls, 108 circulating miRNAs and 1199 placental mRNAs were differentially expressed in RPL samples. A total of 140 overlapping genes (overlapping between plasma miRNA target genes and actual placental disorder genes) were identified, and functional enrichment analysis showed that these genes were mainly related to cell proliferation, angiogenesis, and cell migration. The regulatory network among miRNAs, overlapping genes, and downstream biological processes was analyzed by protein–protein interactions and Cytoscape. Moreover, enriched mRNAs, which were predictive targets of the differentially expressed plasma miRNAs miR-766-5p, miR-1285-3p, and miR-520a-3p, were accordingly altered in the placenta. These results suggest that circulating miRNAs may be involved in the pathogenesis of RPL and are potential noninvasive biomarkers for RPL.

hsa_circ_0000518 Facilitates Non-Small-Cell Lung Cancer Progression via Moderating miR-330-3p and Positively Regulating SLC1A5

Background/Aim

Non-small-cell lung cancer (NSCLC) is the principal agent of cancer deaths globally. The goal of this study was to determine how circular RNA_0000518 (circ_0000518) regulates tumor progression. Materials/Methods. circ_0000518 was selected as a study target involved in NSCLC from GEO (Gene Expression Omnibus) database. circ_0000518 level was gauged by qRT-PCR. It was confirmed as circRNA by actinomycin D inhibition and RNase R assay. Subcellular localization of circ_0000518 was identified by FISH. Cell function was determined by CCK-8, Transwell, and western blot. Glutamine metabolic factors were detected by ELISA. The target regulation relationship between genes was clarified by dual-luciferase reporter assay. In vivo models were established to evaluate the impact of circ_0000518 on tumor growth. Immunohistochemical staining for Ki67, vimentin, and E-cadherin was used to detect cell proliferation and metastasis, respectively.

Results

circ_0000518 expression was enhanced in NSCLC. si-circ_0000518 inhibited cell proliferation, invasion, and glutamine metabolism. circ_0000518 functioned as a molecular sponge for miR-330-3p, and inhibition of miR-330-3p in cells markedly reversed circ_0000518 interference-mediated antitumor effects. miR-330-3p interacted with 3′-UTR of SLC1A5. miR-330-3p inhibitor-mediated protumor effect was remarkably reversed in cells after the knockdown of SLC1A5. circ_0000518 knockdown reduced glutamine, glutamate, and α-KG by targeting miR-330-3p. Intertumoral injection of circ_0000518 shRNA adeno-associated virus effectively halted xenograft tumor growth.

Conclusion

The current study revealed that circ_0000518 may have a prooncogenic function in the formation and progression of NSCLC, which might be achieved through moderating the miR-330-3p/SLC1A5 axis.

The Alteration of m6A Modification at the Transcriptome-Wide Level in Human Villi During Spontaneous Abortion in the First Trimester

A growing number of studies have demonstrated that N6 methyladenine (m⁶A) acts as an important role in the pathogenesis of reproductive diseases. Therefore, it is essential to profile the genome-wide m⁶A modifications such as in spontaneous abortion. In this study, due to the trace of human villi during early pregnancy, we performed high-throughput sequencing in villous tissues from spontaneous abortion (SA group) and controls with induced abortion (normal group) in the first trimester. Based on meRIP-seq data, 18,568 m⁶A peaks were identified. These m⁶A peaks were mainly located in the coding region near the stop codon and were mainly characterized by AUGGAC and UGGACG motif. Compared with normal group, the SA group had 2,159 significantly upregulated m⁶A peaks and 281 downregulated m⁶A peaks. Biological function analyses revealed that differential m⁶A-modified genes were mainly involved in the Hippo and Wnt signaling pathways. Based on the conjoint analysis of meRIP-seq and RNA-seq data, we identified thirty-five genes with differentially methylated m⁶A peaks and synchronously differential expression. And these genes were mainly involved in the Wnt signaling pathway, phosphatase activity regulation, protein phosphatase inhibitor activity, and transcription inhibitor activity. This study is the first to profile the transcriptome-wide m⁶A methylome in spontaneous abortion during early pregnancy, which provide novel insights into the pathogenesis and treatment of spontaneous abortion in the first trimester.

Non-Coding RNAs Regulate Spontaneous Abortion: A Global Network and System Perspective

Spontaneous abortion is a common pregnancy complication that negatively impacts women’s health and commercial pig production. It has been demonstrated that non-coding RNA (ncRNA) is involved in SA by affecting cell proliferation, invasion, apoptosis, epithelial-mesenchymal transformation (EMT), migration, and immune response. Over the last decade, research on ncRNAs in SA has primarily concentrated on micro RNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs). In this review, we discuss recent ncRNA studies focused on the function and mechanism of miRNAs, lncRNAs, and circRNAs in regulating SA. Meanwhile, we suggest that a ceRNA regulatory network exists in the onset and development of SA. A deeper understanding of this network will accelerate the process of the quest for potential RNA markers for SA diagnosis and treatment.

The Circ-CYP24A1-miR-224-PRLR Axis Impairs Cell Proliferation and Apoptosis in Recurrent Miscarriage

Aim

Recurrent miscarriage (RM) is associated with numerous clinical factors. However, some RM occurred without specific factors. It has been revealed that some molecules such as hormones, miRNAs, and transcription factors are involved in RM by regulating proliferation, apoptosis, etc. However, the mechanism of RM has yet to be identified clearly. Circular RNAs (circRNAs) are a class of endogenous non-coding RNAs that often act as sponges for miRNAs or binds to proteins involved in biological processes. However, the functional role of circRNAs in the uterine decidua of patients with early RM is still unclear. In this study, we aimed to investigate the mechanisms of circ-CYP24A1 in RM.

Methods

The Dual-Luciferase Activity Assay was designed to analyze the bonding between circ-CYP24A1 and miR-224, and miR-224 and prolactin receptor (PRLR) mRNA 3′UTR. In situ hybridization (ISH) and immunohistochemistry (IHC) were used to observe the expression of circ-CYP24A1 and PRLR in the decidua. Rescue experiments were performed to investigate the regulating effects of circ-CYP24A1, miR-224, and PRLR. Western blotting was conducted to test the expression level of PRLR. The proliferation and apoptosis-related markers in Ishikawa cells were analyzed using CCK8, immunofluorescence staining, and the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assay.

Results

In this study, based on the microarray analysis data, we identified a high level of circ-CYP24A1 and PRLR in the decidua of patients with early RM. Based on the bioinformatics prediction, the binding relationship between circ-CYP24A1 and miR-224, as well as miR-224 and PRLR, were verified. Functional experiments demonstrated that circ-CYP24A1 regulated proliferation and apoptosis by binding to and inhibiting miR-224, resulting in increased PRLR expression. Taken together, this study provides new insights into the mechanism of RM.

Conclusion

In this study, we found that circ-CYP24A1 plays a role in RM by impairing the balance of cell proliferation and apoptosis by sponging miR-224, thereby regulating PRLR.

Functional Interactions Between lncRNAs/circRNAs and miRNAs: Insights Into Rheumatoid Arthritis

Rheumatoid arthritis (RA) is one of the most common autoimmune diseases that affect synovitis, bone, cartilage, and joint. RA leads to bone and cartilage damage and extra-articular disorders. However, the pathogenesis of RA is still unclear, and the lack of effective early diagnosis and treatment causes severe disability, and ultimately, early death. Accumulating evidence revealed that the regulatory network that includes long non-coding RNAs (lncRNAs)/circular RNAs (circRNAs), micro RNAs (miRNAs), and messenger RNAs (mRNA) plays important roles in regulating the pathological and physiological processes in RA. lncRNAs/circRNAs act as the miRNA sponge and competitively bind to miRNA to regulate the expression mRNA in synovial tissue, FLS, and PBMC, participate in the regulation of proliferation, apoptosis, invasion, and inflammatory response. Thereby providing new strategies for its diagnosis and treatment. In this review, we comprehensively summarized the regulatory mechanisms of lncRNA/circRNA-miRNA-mRNA network and the potential roles of non-coding RNAs as biomarkers and therapeutic targets for the diagnosis and treatment of RA.

Crosstalk Among circRNA/lncRNA, miRNA, and mRNA in Osteoarthritis

Osteoarthritis (OA) is a joint disease that is pervasive in life, and the incidence and mortality of OA are increasing, causing many adverse effects on people's life. Therefore, it is very vital to identify new biomarkers and therapeutic targets in the clinical diagnosis and treatment of OA. ncRNA is a nonprotein-coding RNA that does not translate into proteins but participates in protein translation. At the RNA level, it can perform biological functions. Many studies have found that miRNA, lncRNA, and circRNA are closely related to the course of OA and play important regulatory roles in transcription, post-transcription, and post-translation, which can be used as biological targets for the prevention, diagnosis, and treatment of OA. In this review, we summarized and described the various roles of different types of miRNA, lncRNA, and circRNA in OA, the roles of different lncRNA/circRNA-miRNA-mRNA axis in OA, and the possible prospects of these ncRNAs in clinical application.

Expression profiling of lncRNAs and mRNAs in placental site trophoblastic tumor (PSTT) by microarray

As a rare type of gestational trophoblastic disease, placental site trophoblastic tumor (PSTT) is originated from intermediate trophoblast cells. Long noncoding RNAs (lncRNAs) regulate numerous biological process. However, the role of lncRNAs in PSTT remains poorly understood. In the present study, expression levels of lncRNAs and mRNAs in four human PSTT tissues and four normal placental villi were investigated. The results of microarray were validated by the reverse transcription and quantitative real-time polymerase reaction (RT-qPCR) and immunohistochemistry analyses. Furthermore, GO and KEGG pathway analyses were performed to identify the underlying biological processes and signaling pathways of aberrantly expressed lncRNAs and mRNAs. We also conducted the coding-non-coding gene co-expression (CNC) network to explore the interaction of altered lncRNAs and mRNAs. In total, we identified 1247 up-regulated lncRNAs and 1013 down-regulated lncRNAs as well as 828 up-regulated mRNAs and 1393 down-regulated mRNAs in PSTT tissues compared to normal villi (fold change ≥ 2.0, p < 0.05). GO analysis showed that mitochondrion was the most significantly down-regulated GO term, and immune response was the most significantly up-regulated term. A CNC network profile based on six confirmed lncRNAs (NONHSAT114519, NR_103711, NONHSAT003875, NONHSAT136587, NONHSAT134431, NONHSAT102500) as well as 354 mRNAs was composed of 497 edges. GO and KEGG analyses indicated that interacted mRNAs were enriched in the signal-recognition particle (SRP)-dependent cotranslational protein targeting to membrane and Ribosome pathway. It contributes to expand the understanding of the aberrant lncRNAs and mRNAs profiles of PSTT, which may be helpful for the exploration of new diagnosis and treatment of PSTT.

Role of Transforming Growth Factor-β1 in Regulating Fetal-Maternal Immune Tolerance in Normal and Pathological Pregnancy

Transforming growth factor-β (TGF-β) is composed of three isoforms, TGF-β1, TGF-β2, and TGF-β3. TGF-β1 is a cytokine with multiple biological functions that has been studied extensively. It plays an important role in regulating the differentiation of immune cells and maintaining immune cell functions and immune homeostasis. Pregnancy is a carefully regulated process. Controlled invasion of trophoblasts, precise coordination of immune cells and cytokines, and crosstalk between trophoblasts and immune cells play vital roles in the establishment and maintenance of normal pregnancy. In this systematic review, we summarize the role of TGF-β1 in regulating fetal-maternal immune tolerance in healthy and pathological pregnancies. During healthy pregnancy, TGF-β1 induces the production of regulatory T cells (Tregs), maintains the immunosuppressive function of Tregs, mediates the balance of M1/M2 macrophages, and regulates the function of NK cells, thus participating in maintaining fetal-maternal immune tolerance. In addition, some studies have shown that TGF-β1 is dysregulated in patients with recurrent spontaneous abortion or preeclampsia. TGF-β1 may play a role in the occurrence and development of these diseases and may be a potential target for the treatment of these diseases.

Circular RNA PUM1 (CircPUM1) attenuates trophoblast cell dysfunction and inflammation in recurrent spontaneous abortion via the MicroRNA-30a-5p (miR-30a-5p)/JUNB axis

Recurrent spontaneous abortion (RSA) is a threat to human reproductive health worldwide. CircPUM1 has been reported to participate in the pathogenesis of various diseases. However, there has been no report on its association with RSA yet. In this study, gene expressions were examined by RT-qPCR. Protein levels of JUNB and cleaved caspases-3 were detected by Western blotting. ELISA was used to detect TNF-α, IL-6, and IL-8 levels. Cell viability, migration, invasion, and apoapsis were analyzed using CCK-8, transwell, and flow cytometry assays. The association between miR-30a-5p and circPUM1 or JUNB was identified by bioinformatics analysis, dual-luciferase reporter assay, and RIP assay. Herein, we found circPUM1 was significantly downregulated in RSA placental samples. CircPUM1 knockdown induced decreased proliferation, migration, and invasion, but increased apoptosis, pro-apoptotic protein (cleaved caspases-3) level, and proinflammatory factor (TNF-α, IL-6, and IL-8) secretion in trophoblast cells. Furthermore, we confirmed that circPUM1 was a sponge for miR-30a-5p, and JUNB was directly targeted by miR-30a-5p. It was demonstrated that miR-30a-5p inhibition could reverse trophoblast cell dysfunction and inflammation induced by circPUM1 knockdown. In addition, we found that JUNB expression was negatively modulated by miR-30a-5p and positively regulated by circPUM1. Moreover, circPUM1 inhibition exacerbated dysfunction and inflammation in trophoblast cells via targeting JUNB. To sum up, our study indicated that circPUM1 could impair RSA occurrence and development by facilitating trophoblast cellular processes and protecting against inflammation via the miR-30a-5p/JUNB axis, providing a new target for the improvement of RSA diagnosis and treatment.