MALAT1 recruited the E3 ubiquitin ligase FBXW7 to induce CRY2 ubiquitin-mediated degradation and participated in trophoblast migration and invasion

Advances in post-translational modifications and recurrent spontaneous abortion

Recurrent spontaneous abortion (RSA) is defined as two or more pregnancy loss, which affects approximately 1-2% of women's fertility. The etiology of RSA has not yet been fully revealed, which poses a great problem for clinical treatment. Post- translational modifications(PTMs) are chemical modifications that play a crucial role in the functional proteome. A considerable number of published studies have shown the relationship between post-translational modifications of various proteins and RSA. The study of PTMs contributes to elucidating the role of modified proteins in the pathogenesis of RSA, as well as the design of more effective diagnostic/prognostic tools and more targeted treatments. Most reviews in the field of RSA have only focused on RNA epigenomics research. The present review reports the latest research developments of PTMs related to RSA, such as glycosylation, phosphorylation, Methylation, Acetylation, Ubiquitination, etc.

The Role of MALAT1 in Regulating the Proangiogenic Functions, Invasion, and Migration of Trophoblasts in Selective Fetal Growth Restriction

Epigenetic regulation is an important entry point to study the pathogenesis of selective fetal growth restriction (sFGR), and an understanding of the role of long noncoding RNAs (lncRNAs) in sFGR is lacking. Our study aimed to investigate the potential role of a lncRNA, metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), in sFGR using molecular biology experiments and gain- or loss-of-function assays. We found that the levels of MALAT1, ERRγ, and HSD17B1 were downregulated and that of miR-424 was upregulated in the placental shares of the smaller twins. Moreover, angiogenesis was impaired in the placental share of the smaller fetus and MALAT1 could regulate the paracrine effects of trophoblasts on endothelium angiogenesis and proliferation by regulating miR-424. In trophoblasts, MALAT1 could competitively bind to miR-424 to regulate the expression of ERRγ and HSD17B1, thus regulating trophoblast invasion and migration. MALAT1 overexpression could decrease apoptosis and promote proliferation, alleviating cell damage induced by hypoxia. Taken together, the downregulation of MALAT1 can reduce the expression of ERRγ and HSD17B1 by competitively binding to miR-424, impairing the proangiogenic effect of trophoblasts, trophoblast invasion and migration, and the ability of trophoblasts to compensate for hypoxia, which may be involved in the pathogenesis of sFGR through various aspects.

Dysregulated lncSNHG12 suppresses the invasion and migration of trophoblasts by regulating Dio2/Snail axis to involve in recurrent spontaneous abortion

Recurrent spontaneous abortion (RSA) is a complex pathological process involving diverse factors, in which the dysregulated functions of trophoblasts cannot be ignored. Long noncoding RNA (lncRNA) has been reported to play a significant role in regulating the functions of trophoblasts in RSA. However, the impact and potential mechanism of lncRNA small nucleolar RNA host gene 12 (lncSNHG12) remain unclear. The role of lncSNHG12 in RSA was investigated through in vivo experiments and clinical samples. Co-IP and RNA pull down were conducted to explore the molecular mechanisms in trophoblasts. Our results showed that lncSNHG12 promoted the migration and invasion of trophoblasts by interacting with Iodothyronine deiodinase 2 (Dio2), which regulating the EMT process of trophoblasts by interacting with Snail. Moreover, in vivo experiments confirmed that lncSNHG12 could improve the fetal absorption rate of the abortion mice. The clinical samples revealed that lncSNHG12, Dio2 and Snail were down-regulated in the villous tissues of RSA patients, and positive correlations were confirmed between lncSNHG12 and Dio2, as well as Dio2 and Snail. In summary, the lncSNHG12/Dio2/Snail axis might be involved in the development of RSA by regulating the invasion and migration of trophoblasts. Abbreviations: RSA, recurrent spontaneous abortion; EVTs, extravillous trophoblasts; EMT, epithelial-to-mesenchymal transition; lncRNA, long non-coding RNA; Dio2, iodothyronine deiodinase 2; SNHGs, small nuclear RNA host genes; snoRNAs, small nuclear cell RNAs; LPS, lipopolysaccharide; De, derived decidua; Jz, junctional zone; Lz, labyrinth zones; RIP, RNA Binding Protein Immunoprecipitation; Co-IP, Co-Immunoprecipitation; RPISeq, RNA-Protein Interaction Prediction.

Deciphering the Epigenetic Landscape: Placental Development and Its Role in Pregnancy Outcomes

The placenta stands out as a unique, transitory, and multifaceted organ, essential to the optimal growth and maturation of the fetus. Functioning as a vital nexus between the maternal and fetal circulatory systems, it oversees the critical exchange of nutrients and waste. This exchange is facilitated by placental cells, known as trophoblasts, which adeptly invade and remodel uterine blood vessels. Deviations in placental development underpin a slew of pregnancy complications, notably fetal growth restriction (FGR), preeclampsia (PE), recurrent spontaneous abortions (RSA), and preterm birth. Central to placental function and development is epigenetic regulation. Despite its importance, the intricate mechanisms by which epigenetics influence the placenta are not entirely elucidated. Recently, the scientific community has turned its focus to parsing out the epigenetic alterations during placental development, such as variations in promoter DNA methylation, genomic imprints, and shifts in non-coding RNA expression. By establishing correlations between epigenetic shifts in the placenta and pregnancy complications, researchers are unearthing invaluable insights into the biology and pathophysiology of these conditions. This review seeks to synthesize the latest findings on placental epigenetic regulation, spotlighting its crucial role in shaping fetal growth trajectories and development. Through this lens, we underscore the overarching significance of the placenta in the larger narrative of gestational health.

Unraveling the molecular mechanisms driving enhanced invasion capability of extravillous trophoblast cells: a comprehensive review

Precise extravillous trophoblast (EVT) invasion is crucial for successful placentation and pregnancy. This review focuses on elucidating the mechanisms that promote heightened EVT invasion. We comprehensively summarize the pivotal roles of hormones, angiogenesis, hypoxia, stress, the extracellular matrix microenvironment, epithelial-to-mesenchymal transition (EMT), immunity, inflammation, programmed cell death, epigenetic modifications, and microbiota in facilitating EVT invasion. The molecular mechanisms underlying enhanced EVT invasion may provide valuable insights into potential pathogenic mechanisms associated with diseases characterized by excessive invasion, such as the placenta accreta spectrum (PAS), thereby offering novel perspectives for managing pregnancy complications related to deficient EVT invasion.

LncRNA AOC4P recruits TRAF6 to regulate EZH2 ubiquitination and participates in trophoblast glycolysis and M2 macrophage polarization which is associated with recurrent spontaneous abortion

During embryo implantation, trophoblast cells rely on large amounts of energy produced by glycolysis for their rapid growth and invasion. The disorder of trophoblast metabolism may lead to recurrent spontaneous abortion (RSA). Lactate, which is produced by the glycolysis of trophoblast cells during early pregnancy, can promote the polarization of M2 macrophages and maintain an anti-inflammatory environment at the maternal-fetal interface. Our study found that amine oxidase copper-containing 4 pseudogene (AOC4P) was abnormally increased in villi from RSA patients. It inhibited the glycolysis of trophoblast cells and thus hindered the polarization of M2 macrophages. Further studies showed that AOC4P combines with tumor necrosis factor receptor-associated factor 6 (TRAF6) to upregulate TRAF6 expression. TRAF6 acted as an E3 ubiquitin ligase to promote ubiquitination and degradation of zeste homolog 2 (EZH2). These results provided new insights into the important role played by AOC4P at the maternal-fetal interface.

Microarray profiling of serum micro-RNAs in women with Chlamydia trachomatis-associated recurrent spontaneous abortion: A case control study

Chlamydia trachomatis infection is a major cause of sexually transmitted diseases and adverse pregnancy outcomes such as recurrent spontaneous abortion (RSA). Micro-RNAs (miRNAs) have been known to be upregulated/downregulated in various reproductive-associated diseases such as ectopic pregnancy, preterm birth and pre-eclampsia. However, there is paucity of literature on miRNA profile in C. trachomatis-infected RSA. The present study aimed to determine the profile of serum miRNAs followed by their validation in C. trachomatis-infected RSA and to find target genes involved in biological pathways. Non-heparinized blood and first void urine were collected from 30 non-pregnant women with RSA and 30 non-pregnant women with ≥2 successful deliveries (controls) attending Department of Obstetrics and Gynaecology, Safdarjung hospital, New Delhi, India. C. trachomatis detection was done in urine by PCR and chlamydial load was determined by quantitative real-time PCR (qRT-PCR). miRNA expression was studied by microarray analysis followed by in vitro validation by qRT-PCR. Analysis of target genes/pathways was characterized in silico. 06 RSA patients were infected with C. trachomatis, while chlamydial load was found to be 6000-12,000 copies/ml. 110 circulating miRNAs were expressed differentially in infected RSA patients compared with controls. Of these, 16 were overexpressed and 94 downregulated. 06 differentially expressed circulating miRNAs were selected to validate the microarray results. qRT-PCR data confirmed the reliability of the microarray results: miR-4443, -5100, -7975 showed statistically significant upregulation, while miR-6808-5p, -3148, -6727-5p were significantly downregulated in infected RSA patients versus controls. Chlamydial load was positively correlated with these upregulated miRNAs. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that target genes of miRNAs in RSA are involved in AMPK, Akt and mTOR signaling pathways. Overall results indicate that differentially expressed circulating miRNAs are involved in pathogenesis of C. trachomatis-associated RSA and have the potential to be used as biomarkers for predicting RSA.

Ubiquitin-specific protease 7 prevents recurrent spontaneous abortion by targeting enhancer of zeste homolog 2 to regulate trophoblast proliferation, apoptosis, migration, and invasion through the Wnt/β-catenin pathway†

Trophoblasts are significant components of the placenta and play crucial roles in maternal-fetal crosstalk. Adequate trophoblast migration and invasion are essential for embryo implantation and healthy pregnancy. Ubiquitin-specific protease 7 (USP7), a member of the deubiquitinating enzyme family, regulates the processes of migration and invasion in multiple tumor cells. However, the effects of USP7 on trophoblasts and its possible mechanism in the development of recurrent spontaneous abortion (RSA) are still unclear. In this study, we analyzed the expression of USP7 in villous tissues obtained from RSA patients and healthy controls, and then GNE-6776 (a USP7-specific inhibitor) and USP7 siRNA were used in a trophoblast cell line, HTR-8/SVneo, to further assess the effect of USP7 on the biological function of trophoblasts. Our results provide convincing evidence that USP7 is downregulated in the placental villous tissues of RSA patients. USP7 was found to have a crucial role in the proliferation, apoptosis, migration, invasion, and epithelial-mesenchymal transition (EMT) process of trophoblast cells. Further experiments revealed that USP7 directly interacted with the enhancer of zeste homolog 2 (EZH2) and regulated the Wnt/β-catenin signaling pathway in trophoblasts. Taken together, these findings indicate the vital role of USP7 in regulating trophoblast proliferation, migration and invasion, thus affecting the pathogenesis of RSA, providing new insights into the important role of USP7 in the maternal-fetal interface.

Metastasis-associated lung adenocarcinoma transcript 1 induces methyl-CpG-binding domain protein 4 in mice with recurrent spontaneous abortion caused by anti-phospholipid antibody positivity

INTRODUCTION

Antiphospholipid syndrome is an autoimmune disease characterized by pregnancy-related morbidity, related to persistent positivity of antiphospholipid antibodies (APL). One of the characteristics of pregnancy-related morbidity in patients with antiphospholipid syndrome is recurrent spontaneous abortion (RSA). This study aimed to examine the mechanism through which metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) regulates methyl-CpG-binding domain protein 4 (MBD4) expression in APL-positive RSA.

METHODS

Clinical samples were subjected to microarray analysis to filter differentially expressed genes. RSA mice with APL positivity were generated, followed by adenoviral vector injection to artificially upregulate MALAT1. The effects of MALAT1 on the biological behavior of trophoblast cells were assessed. The downstream mechanism of MALAT1 was analyzed using subcellular fractionation and bioinformatics prediction, and the relationship between MALAT1 and CREB binding protein (CREBBP) or MBD4 was investigated in trophoblast cells.

RESULTS

MALAT1 was downregulated in APL-positive RSA patients. MALAT1 was predominantly localized in the nucleus and recruited CREBBP to mediate the MBD4 transcription. In the APL-positive RSA mice overexpressing MALAT1, the expression of soluble Fms-related tyrosine kinase 1 and anticardiolipin antibody and the embryonic resorption rate were decreased, indicating that MALAT1 reduced the occurrence of RSA in mice. Moreover, MALAT1 enhanced proliferation, migration, and invasion of trophoblast cells through recruiting CREBBP to promote MBD4 expression. Silencing of CREBBP or MBD4 increased embryonic resorption rate in RSA mice overexpressing MALAT1.

DISCUSSION

MALAT1 suppresses APL-positive RSA by promoting MBD4 transcription through recruitment of CREBBP to the MBD4 promoter region.

FBXW7 attenuates tumor drug resistance and enhances the efficacy of immunotherapy

FBXW7 (F-box and WD repeat domain containing 7) is a critical subunit of the Skp1-Cullin1-F-box protein (SCF), acting as an E3 ubiquitin ligase by ubiquitinating targeted protein. Through degradation of its substrates, FBXW7 plays a pivotal role in drug resistance in tumor cells and shows the potential to rescue the sensitivity of cancer cells to drug treatment. This explains why patients with higher FBXW7 levels exhibit higher survival times and more favorable prognosis. Furthermore, FBXW7 has been demonstrated to enhance the efficacy of immunotherapy by targeting the degradation of specific proteins, as compared to the inactivated form of FBXW7. Additionally, other F-box proteins have also shown the ability to conquer drug resistance in certain cancers. Overall, this review aims to explore the function of FBXW7 and its specific effects on drug resistance in cancer cells.

The functions of long noncoding RNAs on regulation of F-box proteins in tumorigenesis and progression

Accumulated evidence has revealed that F-box protein, a subunit of SCF E3 ubiquitin ligase complexes, participates in carcinogenesis and tumor progression via targeting its substrates for ubiquitination and degradation. F-box proteins could be regulated by cellular signaling pathways and noncoding RNAs in tumorigenesis. Long noncoding RNA (lncRNA), one type of noncoding RNAs, has been identified to modulate the expression of F-box proteins and contribute to oncogenesis. In this review, we summarize the role and mechanisms of multiple lncRNAs in regulating F-box proteins in tumorigenesis, including lncRNAs SLC7A11-AS1, MT1JP, TUG1, FER1L4, TTN-AS1, CASC2, MALAT1, TINCR, PCGEM1, linc01436, linc00494, GATA6-AS1, and ODIR1. Moreover, we discuss that targeting these lncRNAs could be helpful for treating cancer via modulating F-box protein expression. We hope our review can stimulate the research on exploration of molecular insight into how F-box proteins are governed in carcinogenesis. Therefore, modulation of lncRNAs is a potential therapeutic strategy for cancer therapy via regulation of F-box proteins.

Recent Insight on Regulations of FBXW7 and Its Role in Immunotherapy

SCF^FBXW7 E3 ubiquitin ligase complex is a crucial enzyme of the ubiquitin proteasome system that participates in variant activities of cell process, and its component FBXW7 (F-box and WD repeat domain–containing 7) is responsible for recognizing and binding to substrates. The expression of FBXW7 is controlled by multiple pathways at different levels. FBXW7 facilitates the maturity and function maintenance of immune cells via functioning as a mediator of ubiquitination-dependent degradation of substrate proteins. FBXW7 deficiency or mutation results in the growth disturbance and dysfunction of immune cell, leads to the resistance against immunotherapy, and participates in multiple illnesses. It is likely that FBXW7 coordinating with its regulators and substrates could offer potential targets to improve the sensitivity and effects of immunotherapy. Here, we review the mechanisms of the regulation on FBXW7 and its tumor suppression role in immune filed among various diseases (mostly cancers) to explore novel immune targets and treatments.

Gypsy retrotransposon-derived maize lncRNA GARR2 modulates gibberellin response

Long non-coding RNAs (lncRNAs) mediate diverse biological events mainly through the modulation of transcriptional hierarchy. The phytohormone gibberellin (GA) is essential for various aspects of plant growth and development. However, the roles of lncRNAs in the regulation of the GA response remain largely unknown. Through sequencing multiple strand-specific and ribosomal-depleted RNA libraries, we delineated the landscape of lncRNAs in maize (Zea mays). Out of identified lncRNAs, 445 GIBBERELLIN-RESPONSIVE lncRNAs (GARRs) were differentially expressed upon GA application. By the intersection of GARRs from normal-height and dwarf plants from an advanced backcross population, four shared GARRs (GARR1 to GARR4) were identified. Out of these four shared GARRs, GARR2 was derived from a Gypsy LTR retrotransposon. GA-responsive element P-boxes were identified upstream of GARR2. GARR2-edited lines exhibited a GA-induced phenotype. Editing of GARR2 resulted in changes in the transcriptional abundance of GA pathway components and endogenous GA contents. Besides GA, GARR2 affected the primary auxin response. An RNA pull-down assay revealed the HECT ubiquitin-protein ligase family member ZmUPL1 as a potential interaction target of GARR2. GARR2 influenced the abundance of ZmUPL1 in the GA response. Our study uncovers lncRNA players involved in the modulation of the GA response and guides the development of plant height ideotype driven by knowledge of the phytohormone GA.

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.