Exosomal miR-486-5p derived from human placental microvascular endothelial cells regulates proliferation and invasion of trophoblasts via targeting IGF1

Circular RNAs from bovine blastocysts can interact with miRNAs/tsRNAs from embryonic extracellular vesicles and regulate hatching

Circular RNAs (circRNAs) are endogenous biological macromolecules that regulate various biological processes including embryo development. However, little is known about which circRNAs are present in bovine preimplantation embryos and their respective roles. Here, we characterized the expression profile of circRNAs in bovine blastocysts for the first time. We detected 25,700 circRNAs in total, with 12,630 circRNAs uniquely expressed in blastocysts compared to degenerated embryos. CircRNA alternative splicing (AS) events were also found more frequently in blastocysts than in degenerated embryos (299 vs 258). Additionally, 410 circRNAs, among which 11 circRNAs with a high potential to encode polypeptides, were found differentially expressed between blastocysts and degenerated embryos. We further predicted and constructed a circRNA-miRNA-mRNA network, wherein differentially expressed circRNAs were shown to bind to bovine preimplantation embryo development-related miRNAs. Employing bioinformatic algorithms we found that differentially expressed circRNAs are associated with differentially expressed miRNAs and transfer RNA-derived small RNAs (tsRNAs) enclosed in embryonic extracellular vesicles (EVs). Furthermore, functional analysis revealed that knockdown of the evolutionarily conserved circAGO2 can inhibit blastocyst hatching. Overall, our study provides the first landscape of circRNAs in bovine preimplantation embryos and highlights the novel role of circRNAs as tsRNA binding partners influencing small RNA sorting and loading into EVs, with circAGO2 playing a regulatory role in bovine blastocyst hatching.

Customizing EV-CATCHER to Purify Placental Extracellular Vesicles from Maternal Plasma to Detect Placental Pathologies

Placenta Accreta Spectrum (PAS) is a life-threatening condition in which placental trophoblastic cells abnormally invade the uterus, often up to the uterine serosa and, in extreme cases, tissues beyond the uterine wall. Currently, there is no clinical assay for the non-invasive detection of PAS, and only ultrasound and MRI can be used for its diagnosis. Considering the subjectivity of visual assessment, the detection of PAS necessitates a high degree of expertise and, in some instances, can lead to its misdiagnosis. In clinical practice, up to 50% of pregnancies with PAS remain undiagnosed until delivery, and it is associated with increased risk of morbidity/mortality. Although many studies have evaluated the potential of fetal biomarkers circulating in maternal blood, very few studies have evaluated the potential of circulating placental extracellular vesicles (EVs) and their miRNA contents for molecular detection of PAS. Thus, to purify placental EVs from maternal blood, we customized our robust ultra-sensitive immuno-purification assay, termed EV-CATCHER, with a monoclonal antibody targeting the membrane Placental Alkaline Phosphatase (PLAP) protein, which is unique to the placenta and present on the surface of placental EVs. Then, as a pilot evaluation, we compared the miRNA expression profiles of placental EVs purified from the maternal plasma of women diagnosed with placenta previa (controls, n = 16); placenta lying low in uterus but not invasive) to those of placental EVs purified from the plasma of women with placenta percreta (cases, n = 16), PAS with the highest level of invasiveness. Our analyses reveal that miRNA profiling of PLAP+ EVs purified from maternal plasma identified 40 differentially expressed miRNAs when comparing these two placental pathologies. Preliminary miRNA pathway enrichment and gene ontology analysis of the top 14 upregulated and top nine downregulated miRNAs in PLAP+ EVs, purified from the plasma of women diagnosed with placenta percreta versus those diagnosed with placenta previa, suggests a potential role in control of cellular invasion and motility that will require further investigation.

Identification of circulatory microRNA based biomarkers for early pregnancy diagnosis in buffalo

Introduction: The most crucial factor in improving animal reproduction efficiency is early pregnancy diagnosis. Early diagnosis not only reduces the time interval between two calvings but also aids farmers in identifying open animals, thereby preventing significant milk production losses. Therefore, the objective of this study was to discover circulatory miRNAs that would be useful for early pregnancy diagnosis in buffalo. Material and methods: Blood samples were taken on 0, 6th, 12th, and 18th day after artificial insemination from pregnant animals (n = 30) and non-pregnant animals (n = 20). During these stages of pregnancy, total RNA was extracted, and a small RNA library was subsequently generated and sequenced on the Illumina platform. Subsequently, Real-time PCR was used to validate the findings. Results and discussion: There were 4,022 miRNAs found during the pregnancy, with 15 of those lacking sequences and 4,007 having sequences already in the database. From the beginning of pregnancy until the 18th day, 25 of these miRNAs showed a substantial shift in expression levels in the maternal blood, with a change more than two logs. Furthermore, based on qPCR results, 19 miRNAs were found to be more abundant in pregnant animals than in non-pregnant animals. We used target prediction analysis to learn how maternally expressed miRNAs relate to fetal-maternal communication. In conclusion, miRNA based biomarkers that could be associated with the diagnosis of pregnancy were identified including miR-181a and miR-486 highly upregulated on the 18th day of pregnancy. This study also provides a comprehensive profile of the entire miRNA population in maternal buffalo blood during the early stages of pregnancy.

Exploring the role of exosomal MicroRNAs as potential biomarkers in preeclampsia

The complex pathogenesis of preeclampsia (PE), a significant contributor to maternal and neonatal mortality globally, is poorly understood despite substantial research. This review explores the involvement of exosomal microRNAs (exomiRs) in PE, focusing on their impact on the protein kinase B (AKT)/hypoxia-inducible factor 1-α (HIF1α)/vascular endothelial growth factor (VEGF) signaling pathway as well as endothelial cell proliferation and migration. Specifically, this article amalgamates existing evidence to reveal the pivotal role of exomiRs in regulating mesenchymal stem cell and trophoblast function, placental angiogenesis, the renin-angiotensin system, and nitric oxide production, which may contribute to PE etiology. This review emphasizes the limited knowledge regarding the role of exomiRs in PE while underscoring the potential of exomiRs as non-invasive biomarkers for PE diagnosis, prediction, and treatment. Further, it provides valuable insights into the mechanisms of PE, highlighting exomiRs as key players with clinical implications, warranting further exploration to enhance the current understanding and the development of novel therapeutic interventions.

Exosomal small RNA profiling in first-trimester maternal blood explores early molecular pathways of preterm preeclampsia

Introduction

Preeclampsia (PE) is a severe obstetrical syndrome characterized by new-onset hypertension and proteinuria and it is often associated with fetal intrauterine growth restriction (IUGR). PE leads to long-term health complications, so early diagnosis would be crucial for timely prevention. There are multiple etiologies and subtypes of PE, and this heterogeneity has hindered accurate identification in the presymptomatic phase. Recent investigations have pointed to the potential role of small regulatory RNAs in PE, and these species, which travel in extracellular vesicles (EVs) in the circulation, have raised the possibility of non-invasive diagnostics. The aim of this study was to investigate the behavior of exosomal regulatory small RNAs in the most severe subtype of PE with IUGR.

Methods

We isolated exosomal EVs from first-trimester peripheral blood plasma samples of women who later developed preterm PE with IUGR (n=6) and gestational age-matched healthy controls (n=14). The small RNA content of EVs and their differential expression were determined by next-generation sequencing and further validated by quantitative real-time PCR. We also applied the rigorous exceRpt bioinformatics pipeline for small RNA identification, followed by target verification and Gene Ontology analysis.

Results

Overall, >2700 small RNAs were identified in all samples and, of interest, the majority belonged to the RNA interference (RNAi) pathways. Among the RNAi species, 16 differentially expressed microRNAs were up-regulated in PE, whereas up-regulated and down-regulated members were equally found among the six identified Piwi-associated RNAs. Gene ontology analysis of the predicted small RNA targets showed enrichment of genes in pathways related to immune processes involved in decidualization, placentation and embryonic development, indicating that dysregulation of the induced small RNAs is connected to the impairment of immune pathways in preeclampsia development. Finally, the subsequent validation experiments revealed that the hsa_piR_016658 piRNA is a promising biomarker candidate for preterm PE associated with IUGR.

Discussion

Our rigorously designed study in a homogeneous group of patients unraveled small RNAs in circulating maternal exosomes that act on physiological pathways dysregulated in preterm PE with IUGR. Therefore, our small RNA hits are not only suitable biomarker candidates, but the revealed biological pathways may further inform us about the complex pathology of this severe PE subtype.

CTRP9 alleviates hypoxia/reoxygenation-induced human placental vascular endothelial cells impairment and mitochondrial dysfunction through activating AMPK/Nrf2 signaling

BACKGROUND

Pregnancy-induced hypertension (PIH) is associated with significant maternal and fetal mortality. The present study is aimed at exploring the molecular mechanism of C1q/TNF-related protein 9 (CTRP9) in PIH.

METHODS

Human placental vascular endothelial cells (HPVECs) underwent hypoxia/reoxygenation (H/R) to construct an in vitro PIH cellular model. Cell transfection was conducted to over-express CTRP9. The expression level of CTRP9 was determined by western blot and quantitative real-time PCR. CCK-8, flow cytometry, wound-healing and tube formation assays were conducted to assess cell viability, apoptosis, migration and angiogenesis, respectively. Mitochondrial membrane potential (∆ψm) was evaluated adopting JC-1 staining. Mitochondrial ROS and copy number (mtDNA) were examined using superoxide indicator and real-time PCR, respectively. Then, HPVECs were pre-treated with Compound C (CC), the inhibitor of AMPK, for regulatory mechanism research.

RESULTS

CTRP9 was downregulated in HPVECs exposed to H/R induction. CTRP9 overexpression retards H/R-mediated cell viability loss and apoptosis, impaired migration and angiogenesis of HPVECs. Meanwhile, CTRP9 overexpression alleviates H/R-mediated mitochondrial dysfunction in HPVECs by enhancing mitochondrial ∆ψm, reducing mitochondrial ROS generation and increasing mtDNA copies. In addition, CTRP9 activated AMPK/Nrf2 signaling in H/R-mediated HPVECs, and additional treatment of CC greatly weakened the functional effects of CTRP9 in H/R-mediated HPVECs.

CONCLUSION

Our results suggested that CTRP9 protected against H/R-mediated HPVECs injuries dependent on AMPK/Nrf2 signaling and could be applied as a potential therapy for PIH.

Early prediction of pre-eclampsia using circulating placental exosomes: Newer insights

Pre-eclampsia (PE), a multifactorial de novo hypertensive pregnancy disorder, is one of the leading causes of foeto-maternal morbidity and mortality. Currently, antihypertensive drugs are the first-line therapy for PE and evidence suggests that low-dose aspirin initiated early in high risk pregnancies may reduce the risk of development or severity of PE. However, an early prediction of this disorder remains an unmet clinical challenge. Several potential serum biomarkers associated with maternal immunoregulation and placental angiogenesis have been evaluated but are ineffective and inconsistent for early prediction. Although placental biomarkers would be more specific and sensitive in predicting the risk of PE, accessing the placenta during pregnancy is not feasible. Circulating placental exosomes (pEXO), originating from foeto-maternal interface, are being evaluated as the placenta's surrogate and the best source of non-invasive placental biomarkers. pEXO appear in the maternal circulation starting from six weeks of gestation and its dynamic biological cargo across pregnancy is associated with successful pregnancy outcomes. Therefore, monitoring changes in pEXO expression profiles could provide new insights into the prediction, diagnosis and treatment of PE. This narrative review comprehensively summarizes the available literature on the candidate predictive circulating biomarkers evaluated for PE to date. In particular, the review elucidates the current knowledge of distinct molecular signatures emanating from pEXO in pre-eclamptic women to support the discovery of novel early predictive biomarkers for effective intervention and management of the disease.

Exosomes: New regulators of reproductive development

Exosomes are a subtype of extracellular vesicles (EVs) with a size range between 30 and 150 ​nm, which can be released by the majority of cell types and circulate in body fluid. They function as a long-distance cell-to-cell communication mechanism that modulates the gene expression profile and fate of target cells. Increasing evidence has indicated exosomes' central role in regulating various complex reproductive processes. However, to our knowledge, a review that focally and vividly describes the role of exosomes in reproductive development is still lacking. This review highlights our knowledge about the contribution of exosomes to early mammalian reproduction, such as gametogenesis, fertilization, early embryonic development, implantation, placentation and pregnancy. The discussion is primarily drawn from literature pertaining to the mammalian lineage with emphasis on the roles of exosomes in human reproduction and laboratory and livestock models.

Endometrial small extracellular vesicles regulate human trophectodermal cell invasion by reprogramming the phosphoproteome landscape

A series of cyclical events within the uterus are crucial for pregnancy establishment. These include endometrial regeneration following menses, under the influence of estrogen (proliferative phase), then endometrial differentiation driven by estrogen/progesterone (secretory phase), to provide a microenvironment enabling attachment of embryo (as a hatched blastocyst) to the endometrial epithelium. This is followed by invasion of trophectodermal cells (the outer layer of the blastocyst) into the endometrium tissue to facilitate intrauterine development. Small extracellular vesicles (sEVs) released by endometrial epithelial cells during the secretory phase have been shown to facilitate trophoblast invasion; however, the molecular mechanisms that underline this process remain poorly understood. Here, we show that density gradient purified sEVs (1.06-1.11 g/ml, Alix⁺ and TSG101⁺, ∼180 nm) from human endometrial epithelial cells (hormonally primed with estrogen and progesterone vs. estrogen alone) are readily internalized by a human trophectodermal stem cell line and promote their invasion into Matrigel matrix. Mass spectrometry-based proteome analysis revealed that sEVs reprogrammed trophectoderm cell proteome and their cell surface proteome (surfaceome) to support this invasive phenotype through upregulation of pro-invasive regulators associated with focal adhesions (NRP1, PTPRK, ROCK2, TEK), embryo implantation (FBLN1, NIBAN2, BSG), and kinase receptors (EPHB4/B2, ERBB2, STRAP). Kinase substrate prediction highlighted a central role of MAPK3 as an upstream kinase regulating target cell proteome reprogramming. Phosphoproteome analysis pinpointed upregulation of MAPK3 T204/T202 phosphosites in hTSCs following sEV delivery, and that their pharmacological inhibition significantly abrogated invasion. This study provides novel molecular insights into endometrial sEVs orchestrating trophoblast invasion, highlighting the microenvironmental regulation of hTSCs during embryo implantation.

The Role and Application of Exosomes and Their Cargos in Reproductive Diseases: A Systematic Review

In recent years, the incidence of the reproductive diseases is increasing year-by-year, leading to abortion or fetal arrest, which seriously affects the reproductive health of human beings and the reproductive efficiency of animals. Exosomes are phospholipid bilayer vesicles that are widely distributed in living organisms and released by the cells of various organs and tissues. Exosomes contain proteins, RNA, lipids, and other components and are important carriers of information transfer between cells, which play a variety of physiological and pathological regulatory functions. More and more studies have found that exosomes and their connotations play an important role in the diagnosis, prognosis and treatment of diseases. A systematic review was conducted in this manuscript and then highlights our knowledge about the diagnostic and therapeutic applications of exosomes to reproductive diseases, such as polycystic ovary syndrome (PCOS), endometriosis, premature ovarian failure (POF), preeclampsia, polycystic, endometrial cancer, cervical cancer, ovarian cancer, and prostate gland cancer.

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

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

Selective Loading and Variations in the miRNA Profile of Extracellular Vesicles from Endothelial-like Cells Cultivated under Normoxia and Hypoxia

Endothelial-like cells may be obtained from CD133⁺ mononuclear cells isolated from human umbilical cord blood (hUCB) and expanded using endothelial-inducing medium (E-CD133 cells). Their use in regenerative medicine has been explored by the potential not only to form vessels but also by the secretion of bioactive elements. Extracellular vesicles (EVs) are prominent messengers of this paracrine activity, transporting bioactive molecules that may guide cellular response under different conditions. Using RNA-Seq, we characterized the miRNA content of EVs derived from E-CD133 cells cultivated under normoxia (N-EVs) and hypoxia (H-EVs) and observed that changing the O₂ status led to variations in the selective loading of miRNAs in the EVs. In silico analysis showed that among the targets of differentially loaded miRNAs, there are transcripts involved in pathways related to cell growth and survival, such as FoxO and HIF-1 pathways. The data obtained reinforce the pro-regenerative potential of EVs obtained from E-CD133 cells and shows that fine tuning of their properties may be regulated by culture conditions.

miRNA-486-5p: signaling targets and role in non-malignant disease

MicroRNAs (miRNAs) are short non-coding RNAs, highly conserved between species, that are powerful regulators of gene expression. Aberrant expression of miRNAs alters biological processes and pathways linked to human disease. miR-486-5p is a muscle-enriched miRNA localized to the cytoplasm and nucleus, and is highly abundant in human plasma and enriched in small extracellular vesicles. Studies of malignant and non-malignant diseases, including kidney diseases, have found correlations with circulating miR-486-5p levels, supporting its role as a potential biomarker. Pre-clinical studies of non-malignant diseases have identified miR-486-5p targets that regulate major signaling pathways involved in cellular proliferation, migration, angiogenesis, and apoptosis. Validated miR-486-5p targets include phosphatase and tensin homolog (PTEN) and FoXO1, whose suppression activates phosphatidyl inositol-3-kinase (PI3K)/Akt signaling. Targeting of Smad1/2/4 and IGF-1 by miR-486-5p inhibits transforming growth factor (TGF)-β and insulin-like growth factor-1 (IGF-1) signaling, respectively. Other miR-486-5p targets include matrix metalloproteinase-19 (MMP-19), Sp5, histone acetyltransferase 1 (HAT1), and nuclear factor of activated T cells-5 (NFAT5). In this review, we examine the biogenesis, regulation, validated gene targets and biological effects of miR-486-5p in non-malignant diseases.

The implications of exosomes in pregnancy: emerging as new diagnostic markers and therapeutics targets

Extracellular vehicles (EVs) are a heterogeneous group of cell and membranous particles originating from different cell compartments. EVs participate in many essential physiological functions and mediate fetal-maternal communications. Exosomes are the smallest unit of EVs, which are delivered to the extracellular space. Exosomes can be released by the umbilical cord, placenta, amniotic fluid, and amniotic membranes and are involved in angiogenesis, endothelial cell migration, and embryo implantation. Also, various diseases such as gestational hypertension, gestational diabetes mellitus (GDM), preterm birth, and fetal growth restriction can be related to the content of placental exosomes during pregnancy. Due to exosomes' ability to transport signaling molecules and their effect on sperm function, they can also play a role in male and female infertility. In the new insight, exosomal miRNA can diagnose and treat infertilities disorders. In this review, we focused on the functions of exosomes during pregnancy.

The Incredible Potential of Exosomes as Biomarkers in the Diagnosis of Colorectal Cancer

Colorectal cancer (CRC) is common cancer that is one of the leading causes of cancerrelated deaths around the world. The creation of new biomarkers for this disease is an important public health strategy for lowering the disease's mortality rate. According to new research, exosomes may be important sources of biomarkers in CRC. Exosomes are nanometer-sized membrane vesicles (30-200 nm) secreted by normal and cancer cells that transport RNA and proteins between cells and are thought to help with intercellular communication. Exosomes have been linked to CRC initiation and progression, and some differentially expressed RNAs and proteins in exosomes have been identified as potential cancer detection candidates. As a result, studying the relationship between exosomes and CRC may aid in the development of new biomarkers for the disease. This article discusses the importance of exosomes as biomarkers in the diagnosis of CRC, as well as their use in the treatment of CRC metastasis, chemoresistance, and recrudescence. The benefits and drawbacks of using exosomes as tumour markers are also discussed.

SNHG22 promotes migration and invasion of trophoblasts via miR-128-3p/PCDH11X axis and activates PI3K/Akt signaling pathway

OBJECTIVES

Long non-coding RNAs (LncRNAs) act as an indispensable role in the Preeclampsia (PE)-related trophoblast function, while its relationship with Small Nucleolar RNA Host Gene 22 (SNHG22) remains unknown. Hence, this study aimed to investigate the roles of lncRNA SNHG22 in the Preeclampsia (PE)-related trophoblasts function and the underlying mechanism.

METHOD

Normal placentas and placentas from PE patients were collected to detect the expression of lncRNA SNHG22. Then, trophoblasts HTR-8/Svneo and JEG-3 were purchased, cultured, and treated to investigate the roles of lncRNA SNHG22 on cell migration and invasion as well as its underlying regulatory mechanism.

RESULTS

The SNHG22 was downregulated in PE patients, and it was found that SNHG22 overexpression could drive migration and invasion of trophoblasts, while SNHG22 depletion exerted a suppressive effect. Mechanistically, SNHG22 was validated to regulate microRNA-128-3p (miR-128-3p), and Protocadherin 11 X-Linked (PCDH11X) was identified as the target gene of miR-128-3p. Furthermore, it was found that SNHG22 acted as a promoter in the migration and invasion of trophoblast cells in a miR-128-3p/PCDH11X dependent manner, and SNHG22 silencing weakened the activation of PCDH11X-mediated PI3K/Akt signaling pathways through inhibiting miR-128-3p, thereby preventing migration and invasion of trophoblasts.

CONCLUSION

SNHG22 acted as a driver in the migration and invasion of trophoblasts and may be considered a candidate for the amelioration of PE.