Dysfunction of pseudogene PGK1P2 is involved in preeclampsia by acting as a competing endogenous RNA of PGK1

Glycolysis: A fork in the path of normal and pathological pregnancy

Glucose metabolism is vital to the survival of living organisms. Since the discovery of the Warburg effect in the 1920s, glycolysis has become a major research area in the field of metabolism. Glycolysis has been extensively studied in the field of cancer and is considered as a promising therapeutic target. However, research on the role of glycolysis in pregnancy is limited. Recent evidence suggests that blastocysts, trophoblasts, decidua, and tumors all acquire metabolic energy at specific stages in a highly similar manner. Glycolysis, carefully controlled throughout pregnancy, maintains a dynamic and coordinated state, so as to maintain the homeostasis of the maternal-fetal interface and ensure normal gestation. In the present review, we investigate metabolic remodeling and the selective propensity of the embryo and placenta for glycolysis. We then address dysregulated glycolysis that occurs in the cellular interactive network at the maternal-fetal interface in miscarriage, preeclampsia, fetal growth restriction, and gestational diabetes mellitus. We provide new insights into the field of maternal-fetal medicine from a metabolic perspective, thus revealing the mystery of human pregnancy.

Phosphoglycerate kinase (PGK) 1 succinylation modulates epileptic seizures and the blood-brain barrier

Epilepsy is the most common chronic disorder in the nervous system, mainly characterized by recurrent, periodic, unpredictable seizures. Post-translational modifications (PTMs) are important protein functional regulators that regulate various physiological and pathological processes. It is significant for cell activity, stability, protein folding, and localization. Phosphoglycerate kinase (PGK) 1 has traditionally been studied as an important adenosine triphosphate (ATP)-generating enzyme of the glycolytic pathway. PGK1 catalyzes the reversible transfer of a phosphoryl group from 1, 3-bisphosphoglycerate (1, 3-BPG) to ADP, producing 3-phosphoglycerate (3-PG) and ATP. In addition to cell metabolism regulation, PGK1 is involved in multiple biological activities, including angiogenesis, autophagy, and DNA repair. However, the exact role of PGK1 succinylation in epilepsy has not been thoroughly investigated. The expression of PGK1 succinylation was analyzed by Immunoprecipitation. Western blots were used to assess the expression of PGK1, angiostatin, and vascular endothelial growth factor (VEGF) in a rat model of lithium-pilocarpine-induced acute epilepsy. Behavioral experiments were performed in a rat model of lithium-pilocarpine-induced acute epilepsy. ELISA method was used to measure the level of S100β in serum brain biomarkers' integrity of the blood-brain barrier. The expression of the succinylation of PGK1 was decreased in a rat model of lithium-pilocarpine-induced acute epilepsy compared with the normal rats in the hippocampus. Interestingly, the lysine 15 (K15), and the arginine (R) variants of lentivirus increased the susceptibility in a rat model of lithium-pilocarpine-induced acute epilepsy, and the K15 the glutamate (E) variants, had the opposite effect. In addition, the succinylation of PGK1 at K15 affected the expression of PGK1 succinylation but not the expression of PGK1total protein. Furthermore, the study found that the succinylation of PGK1 at K15 may affect the level of angiostatin and VEGF in the hippocampus, which also affects the level of S100β in serum. In conclusion, the mutation of the K15 site of PGK1 may alter the expression of the succinylation of PGK1 and then affect the integrity of the blood-brain barrier through the angiostatin / VEGF pathway altering the activity of epilepsy, which may be one of the new mechanisms of treatment strategies.

Altered 5-methylcytosine modification of mRNA is involved in the pathogenesis of pre-eclampsia

5-Methylcytosine (m5 C) is a prevalent RNA modification in messenger RNAs (mRNAs). Despite its abundance, its role in the decidua of pre-eclampsia (PE) remains elusive. In this study, we utilized methylated RNA immunoprecipitation sequencing (MeRIP-seq) and RNA-sequencing (RNA-seq) to map m5 C peaks and mRNA expression profile in the decidua of human early-onset PE (EPE), late-onset PE (LPE), and normal pregnancy (NP). Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses elucidated potential roles of the differentially methylated mRNAs (DMGs) and differentially expressed mRNAs in decidualization pathways. Integrative analysis of MeRIP-seq and RNA-seq data pinpointed 50 candidate genes linked to PE, marked by both differentially methylated m5 C peaks and congruent expression changes. To validate these observations, we selected nine genes for verification via quantitative PCR. Our results underscore the precision and reproducibility of our bioinformatics approach. Importantly, we propose that changes in m5 C modification and expression of relevant mRNA might influence the pathogenesis of PE by hampering decidualization. This work shines light on the distinct mRNA m5 C modification patterns and expression profiles in the decidua of PE, implicating pivotal signaling disruptions and decidualization impediments in the onset of PE.

Characterization of the lncRNA-mediated ceRNA regulatory networks in preeclampsia by integrated bioinformatics

Preeclampsia (PE) is a significant threat to all pregnancies that is highly associated with maternal mortality and developmental disorders in infants. However, the etiopathogenesis of this condition remains unclear. This study aims to explore the regulatory roles of long noncoding RNAs (lncRNAs) and the mediated competing endogenous RNAs (ceRNA) in the etiopathogenesis of PE through analysis of lncRNA expression patterns in PE and healthy pregnant women (HPW), as well as the construction of lncRNA-mediated ceRNA regulatory networks using bioinformatics. A total of 896 significant differentially expressed lncRNAs, including 586 upregulated lncRNAs and 310 downregulated lncRNAs, were identified in comparison between PE and HPW. Analysis of these differential expressed lncRNAs revealed their predominant enrichment in molecular functions such as sphingosine-1-phosphate phosphatase activity, lipid phosphatase activity, phosphatidate phosphatase activity, thymidylate kinase activity, and UMP kinase activity. Moreover, these differential expressed lncRNAs were predominantly enriched in KEGG analyses such as fat digestion and absorption, lysine degradation, ether lipid metabolism, glycerolipid metabolism, and sphingolipid metabolism. Two ceRNA regulatory networks were constructed based on ceRNA score, including one that had 31 upregulated lncRNAs, 11 downregulated miRNAs, and 34 upregulated mRNAs, while the other contained 128 downregulated lncRNAs, 40 upregulated miRNAs, and 113 downregulated mRNAs. These results may provide a clue to explore the roles of lncRNAs in the etiopathogenesis of PE.

Secretory Proteomic Responses of Endometrial Epithelial Cells to Trophoblast-Derived Extracellular Vesicles

Synchronized crosstalk between the embryo and endometrium during the periconception period is integral to pregnancy establishment. Increasing evidence suggests that the exchange of extracellular vesicles (EVs) of both embryonic and endometrial origin is a critical component of embryo-maternal communication during peri-implantation. Here, we investigated whether embryonic signals in the form of EVs can modulate the endometrial epithelial cell secretome. Receptive endometrial analog RL95-2 cells were supplemented with trophoblast analog JAr cell-derived EVs, and the secretory protein changes occurring in the RL95-2 cells were analyzed using mass spectrometry. EVs of non-trophoblastic origin (HEK 293 cells) were used as the control EV source to supplement endometrial cells. Trophoblast cell-derived EVs enriched endometrial epithelial cell secretions with proteins that support embryo development, attachment, or implantation, whereas control EVs were unable to induce the same effect. The present study suggests that embryonic signals in the form of EVs may prime receptive endometrial epithelial cells to enrich their secretory proteome with critical proteomic molecules with functional importance for periconception milieu formation.

lincRNA RP24-315D19.10 promotes endometrial decidualization via upregulation of hnRNPA2B1

Decidualization is a critical process for successful pregnancy. Disorders in this process are tightly associated with adverse pregnancy outcomes including spontaneous abortion. However, the potential molecular mechanisms of lncRNAs underlying this process are yet to be fully elucidated. In this study, we utilized RNA sequencing (RNA-seq) to identify differentially expressed lncRNAs during endometrial decidualization with a pregnant mouse model. Based on RNA-seq analysis, weighted gene co-expression network analysis (WGCNA) was performed to construct the lncRNA-mRNA co-expression network and to identify decidualization-associated hub lncRNAs. Through comprehensive screening and validation, we identified a novel lncRNA, RP24-315D19.10 and studied its function in primary mouse endometrial stromal cells (mESCs). lncRNA RP24-315D19.10 was highly expressed during decidualization. Knockdown of RP24-315D19.10 significantly inhibited mESCs decidualization in vitro. Mechanistically, RNA pull-down and RNA immunoprecipitation assays indicated that cytoplasmic RP24-315D19.10 could bind to hnRNPA2B1, thereby upregulating hnRNPA2B1 expression. Site-directed mutagenesis followed by biolayer interferometry analysis additionally illustrated that hnRNPA2B1 protein specifically bound to the ~-142ccccc~-167 region of the RP24-315D19.10 sequence. hnRPA2B1 deficiency impairs mESCs decidualization in vitro and we found that the inhibition in decidualization caused by RP24-315D19.10 knockdown was rescued by hnRNPA2B1 overexpression. Moreover, the expression of hnRNPA2B1 in spontaneous abortion women with deficient decidualization was significantly lower than that in healthy individuals, suggesting that hnRNPA2B1 may be involved in the development and progression of spontaneous abortion caused by decidualization failure. Collectively, our study indicates RP24-315D19.10 is a critical regulator for endometrial decidualization and RP24-315D19.10-regulated hnRNPA2B1 might be a new mark of decidualization-related spontaneous abortion.

PGK1 modulates balance between pro- and anti-inflammatory cytokines by interacting with ITI-H4

Inter-α-trypsin inhibitor heavy chain 4 (ITI-H4) is one of the acute phase proteins and is mainly related with inflammatory diseases such as bacterial bloodstream infection and recurrent pregnancy loss (RPL). In a previous study, ITI-H4 was reported to be cleaved by kallikrein B1 (KLKB1) and its cleaved form induces the imbalance between pro- and anti-inflammatory cytokines. Therefore, in this study, putative substrates of ITI-H4 were isolated by immunoprecipitation and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS) analysis. Of those, phosphoglycerate kinase 1 (PGK1) was found to be a binding protein of ITI-H4. PGK1 increases the level of ITI-H4 expression and blocks the cleavage of ITI-H4 mediated by KLKB1. It also inhibits pro-inflammatory response by inhibiting the JAK2/STAT3 signaling pathway. Therefore, PGK1, a novel binding partner of ITI-H4, is expected to have cellular functions in the pathogenesis of ITI-H4-related inflammatory diseases.

PVT1/miR-145-5p/HK2 modulates vascular smooth muscle cells phenotype switch via glycolysis: The new perspective on the spiral artery remodeling

INTRODUCTION

Vascular smooth muscle cells (VSMC) switched from a contractile phenotype to a synthetic phenotype during the decidual spiral artery (SPAs) remodeling process. The lncRNA plasmacytoma variant translocation 1 (PVT1) and glucose metabolism have been found to regulate the VSMC phenotype switch. This study aimed to analyze the dynamic expression of PVT1 and glycolytic key enzymes hexokinase2 (HK2) at different remodeling stages in early human pregnancy and elucidate the underlying mechanism of the PVT1/miR-145-5p/HK2 axis involved in the spiral artery remodeling.

METHODS

qRT-PCR, Western blot (WB) analysis, Immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) were used to detect the expression and localization of PVT1 and HK2 in decidual tissue. HA-VSMCs were transfected with specific siRNA, shRNA and plasmids to regulate corresponding genes. Extracellular lactate, cellular ATP, ROS, and intracellular NADPH levels were measured using the corresponding assay kits. Migration was measured by wound-healing and Transwell assays. Contractile phenotypic markers α-SMA, MYH11 with calponin and synthetic phenotypic markers OPN and vimentin were detected by WB. The PDC model was used to detect the degree of spiral arterial remodeling.

RESULTS

PVT1 and HK2 were upregulated with gestational age (GA) increasing in decidual tissue during the early pregnancy. HK2 regulated the glycolytic activity and VSMC phenotype switch in vitro. PVT1 regulated the glycolytic activity and VSMC phenotype switch through HK2. PVT1 played a ceRNA role in regulating HK2 expression by sponging miR-145-5p. PVT1 and HK2 influenced spiral artery remodeling in the PDC model.

DISCUSSION

PVT1 and HK2 were upregulated, and miR-145-5p was downregulated in decidua with the GA increasing. Meanwhile, the PVT1/miR-145-5p/HK2 axis may be involved in regulating the phenotypic switch and migratory capacity of VSMCs by affecting glycolysis in decidual SPAs remodeling.

Dysregulated pseudogene BNIP3P1 inhibited cell proliferation and promoted cell apoptosis in preeclampsia by acting as a competing endogenous RNA for BNIP3

Long noncoding RNAs (lncRNAs) have been reported as critical modulators in many diseases including preeclampsia. Since the association between lncRNA BNIP3P1 and its cognate gene BNIP3 in preeclampsia has been revealed previously, this study aimed to further explore the function and mechanism of BNIP3P1 in preeclampsia. EdU and TUNEL assays revealed that BNIP3P1 or BNIP3 overexpression inhibited trophoblast cell proliferation and enhanced cell apoptosis in preeclampsia. As suggested by western blot analysis, the protein levels of apoptotic markers in the cells were affected by BNIP3P1 or BNIP3 overexpression. The binding between miR-128-3p and BNIP3P1 (or BNIP3) was explored by luciferase reporter assays. Mechanistically, BNIP3P1 bound to miR-128-3p to upregulate BNIP3 expression by acting as a competing endogenous RNA (ceRNA). Importantly, BNIP3P1 was found to inactivate the mTOR signaling pathway. In conclusion, BNIP3P1 inhibited trophoblast cell proliferation and enhanced cell apoptosis in preeclampsia by targeting the miR-128-3p/BNIP3/mTOR signaling pathway.

Non-coding RNAs and their cross-talks impacting reproductive health of women

Non-coding RNAs (ncRNAs) work as crucial posttranscriptional modulators of gene expression regulating a wide array of biological processes that impact normal physiology, including reproductive health. The health of women, especially reproductive health, is now a prime focus of society that ensures the females' overall physical, social, and mental well-being. Furthermore, there has been a growing cognizance of ncRNAs' possible applications in diagnostics and therapeutics of dreaded diseases. Hence, understanding the functions and mode of actions of ncRNAs in the context of women's health will allow us to develop effective prognostic and therapeutic strategies that will enhance the quality of life of women. Herein, we summarize recent progress on ncRNAs, such as microRNAs (miRNAs) and long ncRNAs (lncRNAs), and their implications in reproductive health by tying the knot with lifestyle factors that affect fertility complications, pregnancy outcomes, and so forth. We also discourse the interplay among the RNA species, especially miRNAs, lncRNAs, and protein-coding RNAs, through the competing endogenous RNA regulations in diseases of women associated with maternal and fetal health. This review provides new perspectives correlating ncRNAs, lifestyle, and reproductive health of women, which will attract future studies to improve women's lives. This article is categorized under: RNA in Disease and Development > RNA in Disease Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs.

Dysregulated GLUT1 may be involved in the pathogenesis of preeclampsia by impairing decidualization

Preeclampsia (PE), a hypertensive complication in pregnancy, is a major contributor to maternal and fetal morbidity and mortality. PE has long been regarded a heterogeneous disorder with a pathogenesis that involves multiple genes and factors. Glucose transporter 1 (GLUT1) is a central rate-limiting pump that is involved in glucose uptake and subsequent utilization. Our previous RNA-seq results demonstrated GLUT1 was significantly downregulated in deciduas from patients with severe PE. Therefore, in this study, we aimed to explore the role of GLUT1 in the occurrence of PE. Our data showed that mRNA and protein levels of GLUT1 were significantly downregulated in the deciduas from patients with severe PE. Additionally, GLUT1 levels were substantially upregulated in human endometrial stromal cells (HESCs) during in vitro decidualization. Moreover, GLUT1 knockdown significantly reduced the mRNA levels of decidualization markers (IGFBP1 and PRL) and aerobic glycolysis-related genes (LDHA and MCT4), as well as decreased glucose uptake and lactate production. Furthermore, upon GLUT1 knockdown, the levels of apoptotic genes P53, P21, and BAX increased whereas the level of BCL2 decreased. Target prediction results and luciferase analysis showed that GLUT1 is one of the targets of miR-140-5p, which is partly responsible for downregulated GLUT1 levels. Collectively, these results demonstrate that GLUT1 exerts a pivotal role in human decidualization by participating in glycolysis, and that GLUT1 deficiency may trigger aberrant glycolysis, thereby leading to destructive decidualization that may impede blastocyst implantation, trophoblast invasion, and subsequent placental development, which are associated with PE. Taken together, these data suggest that GLUT1 might be a promising target for PE therapy.

Identification of Circular RNA circ_0017068 as a Regulator of Proliferation and Apoptosis in Trophoblast Cells by miR-330-5p/XIAP Axis

Preeclampsia (PE) is a major and serious complication of pregnancy. Circular RNAs (circRNAs) have been implicated in the initiation and progression of PE. In this paper, we explored the precise actions of circ_0017068 in trophoblast cell functional properties. Ribonuclease (RNase) R, and Actinomycin D treatments were used to characterize circ_0017068. The levels of circ_0017068, microRNA (miR)-330-5p and X-linked inhibitor of apoptosis protein (XIAP) were measured by quantitative real-time polymerase chain reaction (qRT-PCR) or western blot analysis. Cell proliferation, cell cycle progression, and apoptosis were gauged by the Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), and flow cytometry assays, respectively. Direct relationship between miR-330-5p and circ_0017068 or XIAP was validated by dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. Our data showed that circ_0017068 was downregulated in PE placental samples. Enforced expression of circ_0017068 promoted HTR-8/SVneo cell proliferation, cycle progression, and suppressed apoptosis, while silencing of circ_0017068 exhibited opposite effects. Mechanistically, circ_0017068 targeted miR-330-5p, and circ_0017068 regulated proliferation, cycle progression, and apoptosis of HTR-8/SVneo cells through miR-330-5p. Moreover, XIAP was identified as a direct and functional target of miR-330-5p. Furthermore, circ_0017068 operated as a post-transcriptional regulator of XIAP expression through miR-330-5p. Our study identifies circ_0017068 as an important regulator of the proliferation and apoptosis of HTR-8/SVneo trophoblast cells at least in part by miR-330-5p-dependent regulation of XIAP, highlighting circ_0017068 as a potential therapeutic agent for PE treatment.

Gestational Age Dependence of the Maternal Circulating Long Non-Coding RNA Transcriptome During Normal Pregnancy Highlights Antisense and Pseudogene Transcripts

In the post-genomic era, our understanding of the molecular regulators of physiologic and pathologic processes in pregnancy is expanding at the whole-genome level. Longitudinal changes in the known protein-coding transcriptome during normal pregnancy, which we recently reported (Gomez-Lopez et al., 2019), have improved our definition of the major operant networks, yet pregnancy-related functions of the non-coding RNA transcriptome remain poorly understood. A key finding of the ENCODE (Encyclopedia of DNA Elements) Consortium, the successor of the Human Genome Project, was that the human genome contains approximately 60,000 genes, the majority of which do not encode proteins. The total transcriptional output of non-protein-coding RNA genes, collectively referred to as the non-coding transcriptome, is comprised mainly of long non-coding RNA (lncRNA) transcripts (Derrien et al., 2012). Although the ncRNA transcriptome eclipses its protein-coding counterpart in abundance, it has until recently lacked a comprehensive, unbiased, genome-scale characterization over the timecourse of normal human pregnancy. Here, we annotated, characterized, and selectively validated the longitudinal changes in the non-coding transcriptome of maternal whole blood during normal pregnancy to term. We identified nine long non-coding RNAs (lncRNAs), including long intergenic non-coding RNAs (lincRNAs) as well as lncRNAs antisense to or otherwise in the immediate vicinity of protein-coding genes, that were differentially expressed with advancing gestation in normal pregnancy: AL355711, BC039551 (expressed mainly in the placenta), JHDM1D-AS1, A2M-AS1, MANEA-AS1, NR_034004, LINC00649, LINC00861, and LINC01094. By cross-referencing our dataset against major public pseudogene catalogs, we also identified six transcribed pseudogenes that were differentially expressed over time during normal pregnancy in maternal blood: UBBP4, FOXO3B, two Makorin (MKRN) pseudogenes (MKRN9P and LOC441455), PSME2P2, and YBX3P1. We also identified three non-coding RNAs belonging to other classes that were modulated during gestation: the microRNA MIR4439, the small nucleolar RNA (snoRNA) SNORD41, and the small Cajal-body specific ncRNA SCARNA2. The expression profiles of most hits were broadly suggestive of functions in pregnancy. These time-dependent changes of the non-coding transcriptome during normal pregnancy, which may confer specific regulatory impacts on their protein-coding gene targets, will facilitate a deeper molecular understanding of pregnancy and lncRNA-mediated molecular pathways at the maternal-fetal interface and of how these pathways impact maternal and fetal health.

HPV16 E6/E7 stabilize PGK1 protein by reducing its poly-ubiquitination in cervical cancer

This study aimed to explore the expression profile, prognostic value, regulatory effect, and the underlying mechanism of dysregulation of phosphoglycerate kinase 1 (PGK1) in high-risk human papillomavirus (HPV)-positive cervical epithelial squamous cell carcinoma (CESC). Bioinformatic analysis was performed using the CESC subset of The Cancer Genome Atlas (TCGA)-Cervical Cancer (CESC) and normal cervix in The Genotype-Tissue Expression (GTEx) project. HPV-16 positive CaSki and SiHa cells were used as in vitro cell models. Results showed that compared to the normal cervix, CESC tissues had significantly higher expression of PGK1. CESC patients with the higher 50% expression of PGK1 had substantially shorter disease-specific survival (DSS), and progression-free survival (PFS) compared to the cases with the lower 50% expression of PGK1. PGK1 knockdown impaired, but PGK1 overexpression enhanced the proliferation, colony formation, aerobic glycolytic activities (lactate production, intracellular ATP levels, glucose uptake, and extracellular acidification rate), migration, and invasion of CaSki and SiHa cells. HPV-16 E6/E7 knockdown in CaSki and SiHa cells had limited influence on PGK1 transcription but significantly decreased the half-life of PGK1 protein. E6/E7 knockdown mediated PGK1 downregulation could be blocked by adding MG-132. PGK1 poly-ubiquitination was significantly enhanced after E6/E7 knockdown. In conclusion, this study showed that PGK1 expression might serve as a prognostic biomarker in cervical cancer. Its upregulation contributes to enhanced aerobic glycolysis, migration, and invasion of CESC cells. HPV16 E6/E7 stabilizes PGK1 protein by reducing its poly-ubiquitination.

Pseudogene fms-related tyrosine kinase 1 pseudogene 1 (FLT1P1) cooperates with RNA binding protein dyskeratosis congenita 1 (DKC1) to restrain trophoblast cell proliferation and angiogenesis by targeting fms-related tyrosine kinase 1 (FLT1) in preeclampsia

In preeclampsia (PE), preexistent maternal endothelial dysfunction leads to impaired placentation and vascular maladaptation. Long noncoding RNAs (lncRNAs) have been shown to participate in the placentation process. LncRNA fms-related tyrosine kinase 1 pseudogene 1 (FLT1P1) was previously reported to be upregulated in PE. In this study, we verified the effect of FLT1P1 and its cognate gene FLT1 on trophoblast cell proliferation and angiogenesis by using Cell Counting Kit-8 (CCK-8) assay, tube formation assay, and western blot analysis. Their binding to RNA binding protein dyskeratosis congenita 1 (DKC1) was validated by conducting RNA immunoprecipitation (RIP) and RNA pulldown assays. In this study, knockdown of FLT1P1 or FLT1 was found to promote cell proliferation and angiogenesis in trophoblasts. In addition, FLT1P1 recruited DKC1 to stabilize FLT1. Importantly, silencing FLT1P1 or DKC1 decreased the stability of FLT1. Rescue assays revealed that FLT1 overexpression reversed the effect of silenced FLT1P1. Overall, FLT1P1 cooperates with DKC1 to restrain trophoblast cell proliferation and angiogenesis by targeting FLT1.

Silencing of circ_0000517 suppresses proliferation, glycolysis, and glutamine decomposition of non-small cell lung cancer by modulating miR-330-5p/YY1 signal pathway

In recent years, circular RNA (circRNA) has been found to be involved in a variety of cancer processes. More and more attention has been paid to the research of circRNA in lung cancer. This study aims to investigate whether circ_0000517 affected the physiology of non-small cell lung cancer (NSCLC) and the underlying mechanism. The results demonstrated that circ_0000517 was highly expressed in lung cancer tissues and cells, and overexpression of circ_0000517 was negatively correlated with the prognosis of NSCLC patients. Silencing of circ_0000517 significantly inhibited the proliferation, glycolysis, and glutamine decomposition of NSCLC cells in vitro and repressed the growth of xenografted tumors in vivo. Moreover, knockdown of circ_0000517 attenuated the expression of PCNA, HK2, LDHA, ASCT2, and GLS1. Further study found that circ_0000517 targeted miR-330-5p and miR-330-5p targeted YY1. In addition, miR-330-5p inhibitor reversed inhibition of cancer cell proliferation, glycolysis, and glutamine decomposition induced by si-circ_0000517. In conclusion, our study revealed that silencing of circ_0000517 improved the progression of NSCLC through regulating miR-330-5p/YY1 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.

Not So Dead Genes-Retrocopies as Regulators of Their Disease-Related Progenitors and Hosts

Retroposition is RNA-based gene duplication leading to the creation of single exon nonfunctional copies. Nevertheless, over time, many of these duplicates acquire transcriptional capabilities. In human in most cases, these so-called retrogenes do not code for proteins but function as regulatory long noncoding RNAs (lncRNAs). The mechanisms by which they can regulate other genes include microRNA sponging, modulation of alternative splicing, epigenetic regulation and competition for stabilizing factors, among others. Here, we summarize recent findings related to lncRNAs originating from retrocopies that are involved in human diseases such as cancer and neurodegenerative, mental or cardiovascular disorders. Special attention is given to retrocopies that regulate their progenitors or host genes. Presented evidence from the literature and our bioinformatics analyses demonstrates that these retrocopies, often described as unimportant pseudogenes, are significant players in the cell’s molecular machinery.

Energy deficiency caused by CTPS downregulation in decidua may contribute to pre-eclampsia by impairing decidualization

Pre-eclampsia (PE) is a pregnancy-related disorder that occurs after 20 weeks of gestation. It seriously affects the health of maternity and the fetus. However, the pathogenesis of PE is still unknown. Decidualization deficiency is considered a contributing factor to the development of PE. CTP synthetase (CTPS) which is the rate-limiting enzyme in the CTP de novo biosynthesis, is essential for nucleic acid synthesis and cellular energy metabolism, and often appears as cytoophidium in many cell types. Here, we found that the expression of CTPS was significantly downregulated in decidual tissues of patients with severe PE compared with healthy pregnant women. During in vitro decidualization, changes in CTPS were accompanied by opposite fluctuation of the AMPK signaling pathway. Moreover, the downregulation of CTPS by glutamine analogs or CTPS small interfering RNA inhibited the decidualization process and the AMPK signaling pathway. Investigating the underlying mechanism of action by co-immunoprecipitation coupled with mass spectrometry showed that CTPS interacted with ATP synthase (ATPS) and maintained the content of ATP on Day 3 of decidualization. However, when combined with mitochondrial stress protein STRESS-70 instead of ATPS, the concentration of ATP on Day 6 of induction was reduced. Corresponding to this, CTPS was mainly distributes in the cytoplasm on Day 3 of induction, while it appeared both in the cytoplasm and the nucleus on Day 6 in decidualized cells, which was similar to that in cells before induction. In summary, we believe that CTPS plays an important role in decidualization by participating in energy metabolism. Abnormal expression of CTPS in decidualization would lead to abnormal decidualization and consequently result in the occurrence of PE.

lncRNA SNHG14 involved in trophoblast cell proliferation, migration, invasion and epithelial-mesenchymal transition by targeting miR-330-5p in preeclampsia

Preeclampsia (PE), a pregnancy-specific disease, has become one of the leading causes of maternal and neonatal morbidity and mortality. Pathogenesis of PE has still not been fully addressed and there is a great need to develop early diagnosis markers and effective therapy. This study aimed to determine if lncRNA SNHG14 has a protective effect on placental trophoblast and prevents PE. SNHG14 levels in the peripheral blood from patients with PE or from women with healthy pregnancies were detected using RT-qPCR. The relationship between SNHG14 and miR-330-5p was determined using a dual-luciferase reporter assay. In addition, cell proliferation and cell cycle were evaluated by performing CCK8 assays and flow-cytometric analysis, respectively. Wound-healing and transwell assays were performed to assess cell migration and invasion ability. lncRNA SNHG14 was downregulated in PE patients; it was involved in trophoblast proliferation and regulated cell proliferation during G1/S transition. In addition, lncRNA SNHG14 promoted migration, invasion and epithelial-mesenchymal transition (EMT) in HTR-8/SVneo cells. Luciferase reporter assay indicated that lncRNA SNHG14 served as a molecular sponge for miR-330-5p and negatively regulated miR-330-5p expression in PE. Furthermore, the effects of silenced SNHG14 on trophoblast proliferation, migration, invasion and EMT were reversed by addition of miR-330-5p inhibitor, suggesting that in PE lncRNA SNHG14 functions by competitively binding to miR-330-5p. Taken together, the current study demonstrated that in PE lncRNA SNHG14 is a vital regulator by binding to miR-330-5p. SNHG14 might serve as a therapeutic application in PE progression.

Epigenetic modifications working in the decidualization and endometrial receptivity

Decidualization is a critical event for the blastocyst implantation, placental development and fetal growth and the normal term. In mice, the embryo implantation to the uterine epithelial would trigger the endometrial stromal cells to differentiate into decidual stromal cells. However, decidualization in women takes place from the secretory phase of each menstrual cycle and continues to early pregnancy if there is conceptus. Deficient decidualization is often associated with pregnancy specific complications and reproductive disorders. Dramatic changes occur in the gene expression profiles during decidualization, which is coordinately regulated by steroid hormones, growth factors, and molecular and epigenetic mechanisms. Recently, emerging evidences showed that epigenetic modifications, mainly including DNA methylation, histone modification, and non-coding RNAs, play an important role in the decidualization process via affecting the target genes' expression. In this review, we will focus on the epigenetic modifications in decidualization and open novel avenues to predict and treat the pregnancy complications caused by abnormal decidualization.

Comparison of the transcriptional profile in the decidua of early-onset and late-onset pre-eclampsia

AIM

To compare early-onset pre-eclampsia (EOPE) and late-onset pre-eclampsia (LOPE) and provide insight into the pathophysiology of pre-eclampsia (PE).

METHODS

Our recent work compared the transcriptomics in decidua of EOPE, LOPE and normal pregnancies (NP).

RESULTS

We found there are a significant number of genes uniquely expressed in the decidua of EOPE and LOPE comparing with NP. Moreover, EOPE and LOPE have their distinct profiles. Unique EOPE-associated genes were mainly involved in apoptosis related pathways such as 'apoptosis' and 'Ras signaling pathway'. PIK3CB and BCL-2 are the core regulatory genes in EOPE decidua, their abnormal expression caused decidual abnormal apoptosis which is relevant to the pathogenesis of EOPE. Whereas, LOPE is a more complicated entity which has more special LOPE-associated genes involved in decidua differentiation, especially in 'gap junction pathway', 'vascular smooth muscle contraction' and 'long-term depression'. PIK3CB, FLT1, CBLC and ITGA7 are the core regulatory genes differentially expressed in EOPE decidua comparing with LOPE.

CONCLUSION

In brief, the different decidual transcriptomics of EOPE and LOPE may correlate with their different etiology. These findings highlight the complex pathophysiology of PE and provide potential targets for a new treatment strategy in patients with PE.

Re-recognition of pseudogenes: From molecular to clinical applications

Pseudogenes were initially regarded as "nonfunctional" genomic elements that did not have protein-coding abilities due to several endogenous inactivating mutations. Although pseudogenes are widely expressed in prokaryotes and eukaryotes, for decades, they have been largely ignored and classified as gene "junk" or "relics". With the widespread availability of high-throughput sequencing analysis, especially omics technologies, knowledge concerning pseudogenes has substantially increased. Pseudogenes are evolutionarily conserved and derive primarily from a mutation or retrotransposon, conferring the pseudogene with a "gene repository" role to store and expand genetic information. In contrast to previous notions, pseudogenes have a variety of functions at the DNA, RNA and protein levels for broadly participating in gene regulation to influence the development and progression of certain diseases, especially cancer. Indeed, some pseudogenes have been proven to encode proteins, strongly contradicting their "trash" identification, and have been confirmed to have tissue-specific and disease subtype-specific expression, indicating their own value in disease diagnosis. Moreover, pseudogenes have been correlated with the life expectancy of patients and exhibit great potential for future use in disease treatment, suggesting that they are promising biomarkers and therapeutic targets for clinical applications. In this review, we summarize the natural properties, functions, disease involvement and clinical value of pseudogenes. Although our knowledge of pseudogenes remains nascent, this field deserves more attention and deeper exploration.

Long Noncoding RNA in Preeclampsia: Transcriptional Noise or Innovative Indicators?

Preeclampsia (PE) is termed as an obstetric issue that is characterized by hypertension (≧140/90 mm Hg), together with proteinuria following 20 weeks of pregnancy. Until today, PE still constitutes a severe threat to the lives of both the mothers and fetuses. In the past, long noncoding RNAs (lncRNAs) were considered as the transcriptional noise. However, some investigations have indicated that lncRNAs could be used as innovative indicators in PE. The current review aims to discuss the relationship between lncRNAs and PE in recent years. According to the retrieved data, we concluded that lncRNAs can exert an impact on both the occurrence and development of PE through the changes in the biological functions of trophoblasts, immune regulation, epigenetic regulation, decidualization, and energy metabolism. The mechanisms of lncRNAs in PE will help us to better understand the pathogenesis of PE and help us to find targets for predicting and diagnosing PE in the future.

miR-548c-5p inhibits colorectal cancer cell proliferation by targeting PGK1

Accumulating studies have implicated that microRNAs (miRNAs) are involved in the pathogenesis of colorectal cancer (CRC). However, the role of miR-548c-5p, a novel identified miRNA in malignancies, in colorectal carcinogenesis remains largely unknown. The present study is aimed to investigate the effect and molecular mechanism of miR-548c-5p in CRC by a sequence of cellular experiments. miR-548c-5p was significantly downregulated, whereas phosphoglycerate kinase 1 (PGK1), a key enzyme for glycolysis, was obviously upregulated in peripheral blood mononuclear cells and cancer tissues from patients with CRC. Besides, miR-548c-5p and PGK1 were negatively associated with each other. The luciferase reporter assay revealed that PGK1 was a targeted gene of miR-548c-5p. Moreover, the proliferation and generation of inflammatory cytokines (TNF-α and IL-6) were significantly inhibited in miR-548c-5p-overexpressed SW480 CRC cells stimulated by lipopolysaccharide (LPS). Accordingly, miR-548c-5p may serve as a cancer suppressor in CRC by targeting PGK1.