Role of Extracellular Vesicles and microRNAs on Dysfunctional Angiogenesis during Preeclamptic Pregnancies

Proteomic Profiles of Maternal Plasma Extracellular Vesicles for Prediction of Preeclampsia

PROBLEM

Preeclampsia is a heterogeneous syndrome of diverse etiologies and molecular pathways leading to distinct clinical subtypes. Herein, we aimed to characterize the extracellular vesicle (EV)-associated and soluble fractions of the maternal plasma proteome in patients with preeclampsia and to assess their value for disease prediction.

METHOD OF STUDY

This case-control study included 24 women with term preeclampsia, 23 women with preterm preeclampsia, and 94 healthy pregnant controls. Blood samples were collected from cases on average 7 weeks before the diagnosis of preeclampsia and were matched to control samples. Soluble and EV fractions were separated from maternal plasma; EVs were confirmed by cryo-EM, NanoSight, and flow cytometry; and 82 proteins were analyzed with bead-based, multiplexed immunoassays. Quantile regression analysis and random forest models were implemented to evaluate protein concentration differences and their predictive accuracy. Preeclampsia subgroups defined by molecular profiles were identified by hierarchical cluster analysis. Significance was set at p < 0.05 or false discovery rate-adjusted q < 0.1.

RESULTS

In preterm preeclampsia, PlGF, PTX3, and VEGFR-1 displayed differential abundance in both soluble and EV fractions, whereas angiogenin, CD40L, endoglin, galectin-1, IL-27, CCL19, and TIMP1 were changed only in the soluble fraction (q < 0.1). The direction of changes in the EV fraction was consistent with that in the soluble fraction for nine proteins. In term preeclampsia, CCL3 had increased abundance in both fractions (q < 0.1). The combined EV and soluble fraction proteomic profiles predicted preterm and term preeclampsia with an AUC of 78% (95% CI, 66%-90%) and 68% (95% CI, 56%-80%), respectively. Three clusters of preeclampsia featuring distinct clinical characteristics and placental pathology were identified based on combined protein data.

CONCLUSIONS

Our findings reveal distinct alterations of the maternal EV-associated and soluble plasma proteome in preterm and term preeclampsia and identify molecular subgroups of patients with distinct clinical and placental histopathologic features.

Melatonin Regulates the Expression of VEGF and HOXA10 in Bovine Endometrial Epithelial Cells through the SIRT1/PI3K/AKT Pathway

Melatonin plays a critical role in regulating embryo attachment in ruminants. While numerous studies have investigated its effects on early embryo development in vitro, the precise mechanisms by which melatonin influences the receptivity of endometrial epithelial cells in dairy cows remain unclear. The prerequisite for embryo implantation is the specific physiological condition of the endometrium that allows the embryo to implant, also known as endometrial receptivity. In addition to this, endometrial cells undergo processes such as proliferation, differentiation, and renewal, which makes the embryo more easily implanted. In this study, bovine endometrial epithelial cells were cultured and treated with melatonin, Silent Information Regulator 1 (SIRT1) inhibitor (EX527), and protein kinase B (AKT) phosphorylation inhibitor (periposine). RT-qPCR, Western blot, and immunofluorescence analysis were performed to investigate the effects of melatonin on the expression of target gene (SIRT1); cell proliferative genes, phosphatidylinositol-4,5-bisphosphate 3-Kinase (PI3K), AKT, cyclinD1, cyclinE1; and receptive genes (Leukemia Inhibitory Factor (LIF), Vascular Endothelial Growth Factor (VEGF), Homeobox Structure Gene 10 (HOXA10)). Additionally, microRNA (miRNA) mimics and inhibitors were used to transfect the cells to study the regulatory relationship between miRNA and receptive genes. Results indicated that melatonin activates the PI3K/AKT signaling pathway, upregulates cyclinD1 and cyclinE1, and promotes the proliferation of bovine endometrial epithelial cells. Melatonin also upregulated the expression of VEGF and HOXA10 and downregulated the expression of bta-miR-497 and bta-miR-27a-3p through SIRT1/PI3K/AKT signaling pathway. Further, bta-miR-497 and bta-miR-27a-3p were found to negatively regulate VEGF and HOXA10, respectively. Therefore, melatonin regulates the expression of VEGF and HOXA10 through the SIRT1/PI3K/AKT pathway and promotes the establishment of receptivity in bovine endometrial epithelial cells.

Streamlined Analysis of Maternal Plasma Indicates Small Extracellular Vesicles are Significantly Elevated in Early-Onset Preeclampsia

Preeclampsia (PE) is a leading cause of maternal and fetal mortality and morbidity. While placental dysfunction is a core underlying issue, the pathogenesis of this disorder is thought to differ between early-onset (EOPE) and late-onset (LOPE) subtypes. As recent reports suggest that small extracellular vesicles (sEVs) contribute to the development of PE, we have compared systemic sEV concentrations between normotensive, EOPE, and LOPE pregnancies. To circumvent lengthy isolation techniques and intermediate filtration steps, a streamlined approach was developed to evaluate circulating plasma sEVs from maternal plasma. Polymer-based precipitation and purification were used to isolate total systemic circulating maternal sEVs, free from bias toward specific surface marker expression or extensive subpurification. Immediate Nanoparticle Tracking Analysis (NTA) of freshly isolated sEV samples afforded a comprehensive analysis that can be completed within hours, avoiding confounding freeze-thaw effects of particle aggregation and degradation.Rather than exosomal subpopulations, our findings indicate a significant elevation in the total number of circulating maternal sEVs in patients with EOPE. This streamlined approach also preserves sEV-bound protein and microRNA (miRNA) that can be used for potential biomarker analysis. This study is one of the first to demonstrate that maternal plasma sEVs harbor full-length hypoxia inducible factor 1 alpha (HIF-1α) protein, with EOPE sEVs carrying higher levels of HIF-1α compared to control sEVs. The detection of HIF-1α and its direct signaling partner microRNA-210 (miR-210) within systemic maternal sEVs lays the groundwork for identifying how sEV signaling contributes to the development of preeclampsia. When taken together, our quantitative and qualitative results provide compelling evidence to support the translational potential of streamlined sEV analysis for future use in the clinical management of patients with EOPE.

Small RNAs in the pathogenesis of preeclampsia

Preeclampsia is a major contributor to maternal and fetal morbidity and mortality. The disorder can be classified into early- and late-onset subtypes, both of which evolve in two stages. The first stage comprises the development of pre-clinical, utero-placental malperfusion. Early and late utero-placental malperfusion have different causes and time courses. Early-onset preeclampsia (20 % of cases) is driven by dysfunctional placentation in the first half of pregnancy. In late-onset preeclampsia (80 % of cases), malperfusion is a consequence of placental compression within the confines of a limited uterine cavity. In both subtypes, the malperfused placenta releases stress signals into the maternal circulation. These stress signals trigger onset of the clinical syndrome (the second stage). Small RNA molecules, which are implicated in cellular stress responses in general, may be involved at different stages. Micro RNAs contribute to abnormal trophoblast invasion, immune dysregulation, angiogenic imbalance, and syncytiotrophoblast-derived extracellular vesicle signalling in preeclampsia. Transfer RNA fragments are placental signals known to be specifically involved in cell stress responses. Disorder-specific differences in small nucleolar RNAs and piwi-interacting RNAs have also been reported. Here, we summarise key small RNA advances in preeclampsia pathogenesis. We propose that existing small RNA classifications are unhelpful and that non-biased assessment of RNA expression, incorporation of non-annotated molecules and consideration of chemical modifications to RNAs may be important in elucidating preeclampsia pathogenesis.

Recent advances in chemical biology tools for protein and RNA profiling of extracellular vesicles

Extracellular vesicles (EVs) are nano-sized vesicles secreted by cells that contain various cellular components such as proteins, nucleic acids, and lipids from the parent cell. EVs are abundant in body fluids and can serve as circulating biomarkers for a variety of diseases or as a regulator of various biological processes. Considering these characteristics of EVs, analysis of the EV cargo has been spotlighted for disease diagnosis or to understand biological processes in biomedical research. Over the past decade, technologies for rapid and sensitive analysis of EVs in biofluids have evolved, but detection and isolation of targeted EVs in complex body fluids is still challenging due to the unique physical and biological properties of EVs. Recent advances in chemical biology provide new opportunities for efficient profiling of the molecular contents of EVs. A myriad of chemical biology tools have been harnessed to enhance the analytical performance of conventional assays for better understanding of EV biology. In this review, we will discuss the improvements that have been achieved using chemical biology tools.

Value of Non-Coding RNA Expression in Biofluids to Identify Patients at Low Risk of Pathologies Associated with Pregnancy

Pregnancy-related complications (PRC) impact maternal and fetal morbidity and mortality and place a huge burden on healthcare systems. Thus, effective diagnostic screening strategies are crucial. Currently, national and international guidelines define patients at low risk of PRC exclusively based on their history, thus excluding the possibility of identifying patients with de novo risk (patients without a history of disease), which represents most women. In this setting, previous studies have underlined the potential contribution of non-coding RNAs (ncRNAs) to detect patients at risk of PRC. However, placenta biopsies or cord blood samples are required, which are not simple procedures. Our review explores the potential of ncRNAs in biofluids (fluids that are excreted, secreted, or developed because of a physiological or pathological process) as biomarkers for identifying patients with low-risk pregnancies. Beyond the regulatory roles of ncRNAs in placental development and vascular remodeling, we investigated their specific expressions in biofluids to determine favorable pregnancy outcomes as well as the most frequent pathologies of pregnant women. We report distinct ncRNA panels associated with PRC based on omics technologies and subsequently define patients at low risk. We present a comprehensive analysis of ncRNA expression in biofluids, including those using next-generation sequencing, shedding light on their predictive value in clinical practice. In conclusion, this paper underscores the emerging significance of ncRNAs in biofluids as promising biomarkers for risk stratification in PRC. The investigation of ncRNA expression patterns and their potential clinical applications is of diagnostic, prognostic, and theragnostic value and paves the way for innovative approaches to improve prenatal care and maternal and fetal outcomes.

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.

Current knowledge on the role of extracellular vesicles in endometrial receptivity

Endometrial receptivity has been widely understood as the capacity of the endometrium to receive implantable embryos. The establishment of endometrial receptivity involves multiple biological processes including decidualization, tissue remodeling, angiogenesis, immune regulation, and oxidative metabolism. Extracellular vesicles (EVs) are lipid-bilayer-membrane nanosized vesicles mediating cell-to-cell communication. Recently, EVs and their cargo have been proven as functional factors in the establishment of endometrial receptivity. In this review, we comprehensively summarized the alteration of endometrium/embryo-derived EVs during the receptive phase and retrospected the current findings which revealed the pivotal role and potential mechanism of EVs to promote successful implantation. Furthermore, we highlight the potentiality and limitations of EVs being translated into clinical applications such as biomarkers of endometrial receptivity or reproductive therapeutic mediators, and point out the direction for further research.

Extracellular vesicles during the three trimesters of pregnancy

OBJECTIVES

Extracellular vesicles (EVs) are cell-derived particles released during different pathophysiological processes and emerging as relevant players in inter-cellular crosstalk. Previous studies have highlighted the role of EVs as potential biomarkers for several pregnancy complications, including miscarriage, pre-eclampsia and gestational diabetes. Despite that, the actual distribution of EVs through gestation has not been reported yet. The aim of this study was to report the concentration of different sub-types of EVs in the first, second and third trimester of pregnancy and to correlate them with different pregnancy and ultrasound characteristics.

STUDY DESIGNS

Prospective observational study including uncomplicated pregnancies in the first, second and third trimester of pregnancy. The first aim of the study was to report the concentration of the EVs derived from endothelial, epithelial, platelet and leukocyte cells of maternal peripheral blood samples in the first, second and third trimester pregnancy using polychromatic flow cytometry. The secondary aim was to correlate EVs with neonatal birthweight and fetal Dopplers, including uterine and umbilical arteries. Un and multivariate analyses were used to compute the data.

RESULTS

64 women (20 in the first, 22 in the second and 22 in the third trimester of pregnancies) were included in the analysis. There was no difference in the median concentration of either platelet, leukocyte and endothelial EVs between the first, second and third trimester of pregnancy. The concentration of epithelial derived EVs was higher in the third compared to first and second trimester of pregnancy. When analyzing the percentage of EV vesicles through gestation, there was no difference in the percentage of either leukocyte or endothelial EVs through gestation. Conversely, the median percentage of platelet derived vesicles was higher in the first (48.7 %, IQR 34.1-58.5) compared to second (34.0 %, IQR 22.7-44.9) and third (9.13 %, IQR 5.01-12.1) trimester of pregnancy, while the median percentage of third trimester (6.01, IQR 2.42-7.34) epithelial derived vesicles was higher than that of the second (1.53 %, IQR 0.65-2.98), but not of the first (4.45 %, IQR 1.44-6.07) trimester. Finally, we found no association between the median concentration or percentage of endothelial, epithelial, leukocyte vesicles, neonatal birthweight and fetal or maternal Dopplers.

CONCLUSIONS

Distribution of EVs examined does not change during the three trimesters of pregnancy and is not influenced by neonatal birthweight or maternal and fetal Dopplers. The findings from this study allows a more objective interpretation of studies comparing EVs in pregnancies with compared to those without obstetric complication. EVs in future can be used for "liquid biopsy" for the early diagnosis of pathological pregnancies up to the development of possible screening protocols.

Placental Exosomes as Biomarkers for Maternal Diseases: Current Advances in Isolation, Characterization, and Detection

Serving as the interface between fetal and maternal circulation, the placenta plays a critical role in fetal growth and development. Placental exosomes are small membrane-bound extracellular vesicles released by the placenta during pregnancy. They contain a variety of biomolecules, including lipids, proteins, and nucleic acids, which can potentially be biomarkers of maternal diseases. An increasing number of studies have demonstrated the utility of placental exosomes for the diagnosis and monitoring of pathological conditions such as pre-eclampsia and gestational diabetes. This suggests that placental exosomes may serve as new biomarkers in liquid biopsy analysis. This review provides an overview of the current understanding of the biological function of placental exosomes and their potential as biomarkers of maternal diseases. Additionally, this review highlights current barriers and the way forward for standardization and validation of known techniques for exosome isolation, characterization, and detection. Finally, microfluidic devices for exosome research are discussed.

EVs-mediated delivery of CB2 receptor agonist for Alzheimer's disease therapy

Alzheimer's disease (AD) is a typical neurodegenerative disease that leads to irreversible neuronal degeneration, and effective treatment remains elusive due to the unclear mechanism. We utilized biocompatible mesenchymal stem cell-derived extracellular vesicles as carriers loaded with the CB2 target medicine AM1241 (EVs-AM1241) to protect against neurodegenerative progression and neuronal function in AD model mice. According to the results, EVs-AM1241 were successfully constructed and exhibited better bioavailability and therapeutic effects than bare AM1241. The Morris water maze (MWM) and fear conditioning tests revealed that the learning and memory of EVs-AM1241-treated model mice were significantly improved. In vivo electrophysiological recording of CA1 neurons indicated enhanced response to an auditory conditioned stimulus following fear learning. Immunostaining and Western blot analysis showed that amyloid plaque deposition and amyloid β (Aβ)-induced neuronal apoptosis were significantly suppressed by EVs-AM1241. Moreover, EVs-AM1241 increased the number of neurons and restored the neuronal cytoskeleton, indicating that they enhanced neuronal regeneration. RNA sequencing revealed that EVs-AM1241 facilitated Aβ phagocytosis, promoted neurogenesis and ultimately improved learning and memory through the calcium-Erk signaling pathway. Our study showed that EVs-AM1241 efficiently reversed neurodegenerative pathology and enhanced neurogenesis in model mice, indicating that they are very promising particles for treating AD.

sFlt-1-enriched exosomes induced endothelial cell dysfunction and a preeclampsia-like phenotype in mice

Preeclampsia (PE) is a hypertensive disorder of pregnancy characterized by maternal endothelial dysfunction and end-organ damage. Our previous work demonstrated that PE patient-derived exosomes contained higher levels of soluble FMS-like tyrosine kinase-1 (sFlt-1) and significantly induced endothelial dysfunction and PE development. However, the mechanisms underlying the effect of sFlt-1-enriched exosomes (sFlt-1-Exo) on PE development are poorly characterized. Here, we revealed that trophoblast-derived sFlt-1-Exo treatment induced significant inhibition of human umbilical vein endothelial cell (HUVEC) migration and tube formation, as well as an increase in sFlt-1 secretion. Mechanistically, we found that the increased sFlt-1 secretion in the cell culture medium was attributed to enhanced transcription of sFlt-1 in HUVECs. Importantly, we observed that treating pregnant mice with sFlt-1-Exo or recombinant mouse sFlt-1 triggered a preeclampsia-like phenotype, characterized by elevated blood pressure, proteinuria, increased plasma sFlt-1 and adverse pregnancy outcomes. These results strongly suggested that sFlt-1-Exo-induced endothelial dysfunction could be partially attributed to the upregulation of sFlt-1 in endothelial cells, potentially leading to the development of a preeclampsia-like phenotype in mice.

Epigenetic Mechanisms Involved in the Effects of Maternal Hyperhomocysteinemia on the Functional State of Placenta and Nervous System Plasticity in the Offspring

According to modern view, susceptibility to diseases, specifically to cognitive and neuropsychiatric disorders, can form during embryonic development. Adverse factors affecting mother during the pregnancy increase the risk of developing pathologies. Despite the association between elevated maternal blood homocysteine (Hcy) and fetal brain impairments, as well as cognitive deficits in the offspring, the role of brain plasticity in the development of these pathologies remains poorly studied. Here, we review the data on the negative impact of hyperhomocysteinemia (HHcy) on the neural plasticity, in particular, its possible influence on the offspring brain plasticity through epigenetic mechanisms, such as changes in intracellular methylation potential, activity of DNA methyltransferases, DNA methylation, histone modifications, and microRNA expression in brain cells. Since placenta plays a key role in the transport of nutrients and transmission of signals from mother to fetus, its dysfunction due to aberrant epigenetic regulation can affect the development of fetal CNS. The review also presents the data on the impact of maternal HHcy on the epigenetic regulation in the placenta. The data presented in the review are not only interesting from purely scientific point of view, but can help in understanding the role of HHcy and epigenetic mechanisms in the pathogenesis of diseases, such as pregnancy pathologies resulting in the delayed development of fetal brain, cognitive impairments in the offspring during childhood, and neuropsychiatric and neurodegenerative disorders later in life, as well as in the search for approaches for their prevention using neuroprotectors.

Placenta-Derived Extracellular Vesicles in Pregnancy Complications and Prospects on a Liquid Biopsy for Hemoglobin Bart's Disease

Extracellular vesicles (EVs) are nano-scaled vesicles released from all cell types into extracellular fluids and specifically contain signature molecules of the original cells and tissues, including the placenta. Placenta-derived EVs can be detected in maternal circulation at as early as six weeks of gestation, and their release can be triggered by the oxygen level and glucose concentration. Placental-associated complications such as preeclampsia, fetal growth restriction, and gestational diabetes have alterations in placenta-derived EVs in maternal plasma, and this can be used as a liquid biopsy for the diagnosis, prediction, and monitoring of such pregnancy complications. Alpha-thalassemia major ("homozygous alpha-thalassemia-1") or hemoglobin Bart's disease is the most severe form of thalassemia disease, and this condition is lethal for the fetus. Women with Bart's hydrops fetalis demonstrate signs of placental hypoxia and placentomegaly, thereby placenta-derived EVs provide an opportunity for a non-invasive liquid biopsy of this lethal condition. In this article, we introduced clinical features and current diagnostic markers of Bart's hydrops fetalis, extensively summarize the characteristics and biology of placenta-derived EVs, and discuss the challenges and opportunities of placenta-derived EVs as part of diagnostic tests for placental complications focusing on Bart's hydrop fetalis.

The application of tumor cell-derived vesicles in oncology therapy

Tumor cell-derived vesicles are released by tumor cells, have a phospholipid bilayer, and are widely distributed in various biological fluids. In recent years, it has been found that tumor cell-derived vesicles contain proteins, metabolites and nucleic acids and can be delivered to recipient cells to perform their physiological functions, such as mediating specific intercellular communication, activating or inhibiting signaling pathways, participating in regulating the modulation of tumor microenvironment and influencing tumor development, which can be used for early detection and diagnosis of cancer. In addition, tumor cell-derived vesicles exhibit multiple properties in tumor therapeutic applications and may serve as a new class of delivery systems. In this review, we elaborate on the application of tumor cell-derived vesicles in oncology therapy.

Brain Vascular Dysfunction in Mothers and Their Children Exposed to Preeclampsia

Preeclampsia is a maternal syndrome characterized by the new onset of hypertension and proteinuria after 20 weeks of gestation associated with multisystemic complications, including brain alterations. Indeed, brain complications associated with preeclampsia are the leading direct causes of fetal and maternal morbidity and mortality, especially in low- and middle-income countries. In addition to the well-recognized long-term adverse cardiovascular effects of preeclampsia, women who have had preeclampsia have higher risk of stroke, dementia, intracerebral white matter lesions, epilepsy, and perhaps also cognitive decline postpartum. Furthermore, increasing evidence has also associated preeclampsia with similar cognitive and cerebral disorders in the offspring. However, the mechanistic links between these associations remain unresolved. This article summarizes the current knowledge about the cerebrovascular complications elicited by preeclampsia and the potential pathophysiological mechanisms involved, emphasizing the impaired brain vascular function in the mother and their offspring.

Extracellular Vesicles as Biomarkers and Therapeutics for Inflammatory Eye Diseases

Extracellular vesicles (EVs) are a group of cell-derived membrane vesicles of varying sizes that can be secreted by most cells. Depending on the type of cell they are derived from, EVs may contain a variety of cargo including proteins, lipids, miRNA, and DNA. Functionally, EVs play important roles in physiological and pathological processes through intercellular communication. While there has already been significant literature on the involvement of EVs in neurological and cardiovascular disease as well as cancer, recent evidence suggests that EVs may also play a role in mediating inflammatory eye diseases. This paper summarizes current advancements in ocular EV research as well as new ways by which EVs may be utilized as novel biomarkers of or therapeutics for inflammatory eye diseases.

Early steps of embryo implantation are regulated by exchange of extracellular vesicles between the embryo and the endometrium

In early pregnancy, as the embryo arrives in the uterus, intensive communication between the embryo and uterus begins. Hundreds of molecules are known to be involved, but despite numerous findings, full understanding of the complexity of the embryo-maternal dialog remains elusive. Recently, extracellular vesicles, nanoparticles able to transfer functionally active cargo between cells, have emerged as important players in cell-cell communication, and as such, they have gained great attention over the past decade also in reproductive biology. Here, we use a domestic animal model (Sus scrofa) with an epitheliochorial, superficial type of placentation because of its advantage in studding uterine luminal fluid extracellular vesicles. We show that during early pregnancy, the uterine lumen is abundant with extracellular vesicles that carry a plethora of miRNAs able to target genes involved in embryonic and organismal development. These extracellular vesicles, upon the delivery to primary trophoblast cells, affect genes governing development as well as cell-to-cell signaling and interactions, consequently having an impact on trophoblast cell proliferation, migration, and invasion. We conclude that the exchange of a unique population of extracellular vesicles and their molecular cargo at the maternal-embryo interface is the key to the success of embryo implantation and pregnancy.

Utility of Exosomes in Ischemic and Hemorrhagic Stroke Diagnosis and Treatment

Stroke is the leading cause of death and neurological disorders worldwide. However, diagnostic techniques and treatments for stroke patients are still limited for certain types of stroke. Intensive research has been conducted so far to find suitable diagnostic techniques and treatments, but so far there has been no success. In recent years, various studies have drawn much attention to the clinical value of utilizing the mechanism of exosomes, low toxicity, biodegradability, and the ability to cross the blood–brain barrier. Recent studies have been reported on the use of biomarkers and protective and recovery effects of exosomes derived from stem cells or various cells in the diagnostic stage after stroke. This review focuses on publications describing changes in diagnostic biomarkers of exosomes following various strokes and processes for various potential applications as therapeutics.

Promising Role of Oral Cavity Mesenchymal Stem Cell-Derived Extracellular Vesicles in Neurodegenerative Diseases

Mesenchymal stem cells (MSCs) and mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) have been regarded as the beneficial and available tools to treat various hereditary, multifactorial, acute, and chronic diseases. Mesenchymal stem cells can be extracted from numerous sources for clinical purposes while oral cavity-derived mesenchymal stem cells seem to be more effective in neuroregeneration than other sources due to their similar embryonic origins to neuronal tissues. In various studies and different neurodegenerative diseases (NDs), oral cavity mesenchymal stem cells have been applied to prove their promising capacities in disease improvement. Moreover, oral cavity mesenchymal stem cells' secretion is regarded as a novel and practical approach to neuroregeneration; hence, extracellular vesicles (EVs), especially exosomes, may provide promising results to improve CNS defects. This review article focuses on how oral cavity-derived stem cells and their extracellular vesicles can improve neurodegenerative conditions and tries to show which molecules are involved in the recovery process.

The Role of Non-Coding RNAs in the Human Placenta

Non-coding RNAs (ncRNAs) play a central and regulatory role in almost all cells, organs, and species, which has been broadly recognized since the human ENCODE project and several other genome projects. Nevertheless, a small fraction of ncRNAs have been identified, and in the placenta they have been investigated very marginally. To date, most examples of ncRNAs which have been identified to be specific for fetal tissues, including placenta, are members of the group of microRNAs (miRNAs). Due to their quantity, it can be expected that the fairly larger group of other ncRNAs exerts far stronger effects than miRNAs. The syncytiotrophoblast of fetal origin forms the interface between fetus and mother, and releases permanently extracellular vesicles (EVs) into the maternal circulation which contain fetal proteins and RNA, including ncRNA, for communication with neighboring and distant maternal cells. Disorders of ncRNA in placental tissue, especially in trophoblast cells, and in EVs seem to be involved in pregnancy disorders, potentially as a cause or consequence. This review summarizes the current knowledge on placental ncRNA, their transport in EVs, and their involvement and pregnancy pathologies, as well as their potential for novel diagnostic tools.

Single extracellular vesicle analysis in human amniotic fluid shows evidence of phenotype alterations in preeclampsia

Amniotic fluid surrounding the developing fetus is a complex biological fluid rich in metabolically active bio-factors. The presence of extracellular vesicles (EVs) in amniotic fluid has been mainly related to foetal urine. We here characterized EVs from term amniotic fluid in terms of surface marker expression using different orthogonal techniques. EVs appeared to be a heterogeneous population expressing markers of renal, placental, epithelial and stem cells. Moreover, we compared amniotic fluid EVs from normal pregnancies with those of preeclampsia, a hypertensive disorder affecting up to 8% of pregnancies worldwide. An increase of CD105 (endoglin) expressing EVs was observed in preeclamptic amniotic fluid by bead-based cytofluorimetric analysis, and further confirmed using a chip-based analysis. HLA-G, a typical placental marker, was not co-expressed by the majority of CD105+ EVs, in analogy with amniotic fluid stromal cell derived-EVs. At a functional level, preeclampsia-derived EVs, but not normal pregnancy EVs, showed an antiangiogenic effect, possibly due to the decoy effect of endoglin. Our results provide a characterization of term amniotic fluid-EVs, supporting their origin from foetal and placental cells. In preeclampsia, the observed antiangiogenic characteristics of amniotic fluid-EVs may reflect the hypoxic and antiangiogenic microenvironment and could possibly impact on the developing fetus or on the surrounding foetal membranes.

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. Video abstract.

Lysine (K)-specific demethylase 5C regulates the incidence of severe preeclampsia by adjusting the expression of bone morphogenetic protein-7

This study aimed to investigate the roles of the lysine (K)-specific demethylase 5C (KDM5C)-bone morphogenetic protein-7 (BMP-7) signaling pathway in the pathogenesis of severe preeclampsia (sPE). A total of 180 pregnant patients were enrolled in the study and classified into three groups: an early-onset sPE group (EOsPE) (n = 60), a late-onset sPE group (LOsPE) (n = 60), and a control group (normal pregnancy; n = 60). The messenger RNA (mRNA) and protein expression levels of bone morphogenetic protein receptor II (BMPRII), BMP-7, and KDM5C were detected in placenta samples from the two sPE groups, and their sites were evaluated using immunohistochemistry (IHC). The sPE groups showed an increased KDM5C mRNA expression, and the EOsPE group showed a decreased BMP-7 and BMPRII mRNA expression compared with the LOsPE group. However, contradictory results were discovered in terms of protein expression. Immunostaining of KDM5C, BMP-7, and BMPRII was observed in villous trophoblast and extravillous trophoblast cells. Compared with the control group, the staining intensity of KDM5C in the placental tissue trophoblast cell nucleus and vascular endothelial cells of the sPE groups was weaker, while that of BMP-7 and BMPRII was stronger, and the staining intensity was more subjective in the LOsPE group. Consistent findings were obtained by IHC and Western blot analysis. KDM5C nuclear-cytoplasmic translocation may regulate sPE through BMP-7 and its receptors. The KDM5C-BMP-7 signaling pathway may also lead to less invasion and increased apoptosis of the trophoblast cells, which is involved in the pathogenesis of sPE.

Small RNA sequencing reveals placenta-derived exosomal microRNAs associated with preeclampsia

OBJECTIVE

Preeclampsia is one of the most important complications during pregnancy and the leading cause of maternal morbidity and mortality; however, the pathogenesis of preeclampsia remains partially misunderstood. The aim of this study was to identify placenta-derived exosomal microRNAs (miRNAs) involved in the preeclampsia process.

METHODS

Peripheral blood was collected from normal and preeclampsia pregnant women, and placenta-derived exosomes were extracted. Small RNA sequencing was performed to identify the exosomal miRNAs involved in preeclampsia. The function of a differentially expressed exosomal miRNA was verified.

RESULTS

The extracted exosomes presented round or oval-like structures with diameters of approximately 80 nm and could be recognized by antibodies against CD9, CD81, and placental alkaline phosphatase. A total of 1013 exosomal miRNAs were identified by small RNA sequencing, of which 946 were known miRNAs and 67 were novel miRNAs. Twenty-six miRNAs were identified as differentially expressed when comparing the data of the preeclampsia and normal groups. One of the differentially expressed miRNAs, hsa-miR-370-3p, which was upregulated in the preeclampsia group, was shown to bind to the 3' untranslated region of C-X-C motif chemokine 12, a chemokine that plays important role during preeclampsia process. Moreover, functional analysis revealed that hsa-miR-370-3p could inhibit proliferation, migration, and invasion while promoting apoptosis of HTR-8/SVneo cells.

CONCLUSION

A total of 1013 placenta-derived exosomal miRNAs were identified by small RNA sequencing, of which 26 were differentially expressed. The function of one differentially expressed miRNA (hsa-miR-370-3p) was verified. Our results provide new perspectives on the pathogenesis of preeclampsia and potential biomarkers for preeclampsia diagnosis.

Extracellular vesicles and immune response during pregnancy: A balancing act

The mechanisms underlying maternal tolerance of the semi- or fully-allogeneic fetus are intensely investigated. Across gestation, feto-placental antigens interact with the maternal immune system locally within the trophoblast-decidual interface and distantly through shed cells and soluble molecules that interact with maternal secondary lymphoid tissues. The discovery of extracellular vesicles (EVs) as local or systemic carriers of antigens and immune-regulatory molecules has added a new dimension to our understanding of immune modulation prior to implantation, during trophoblast invasion, and throughout the course of pregnancy. New data on immune-regulatory molecules, located on EVs or within their cargo, suggest a role for EVs in negotiating immune tolerance during gestation. Lessons from the field of transplant immunology also shed light on possible interactions between feto-placentally derived EVs and maternal lymphoid tissues. These insights illuminate a potential role for EVs in major obstetrical disorders. This review provides updated information on intensely studied, pregnancy-related EVs, their cargo molecules, and patterns of fetal-placental-maternal trafficking, highlighting potential immune pathways that might underlie immune suppression or activation in gestational health and disease. Our summary also underscores the likely need to broaden the definition of the maternal-fetal interface to systemic maternal immune tissues that might interact with circulating EVs.

An integrated model of preeclampsia: a multifaceted syndrome of the maternal cardiovascular-placental-fetal array

Maternal tolerance of the semiallogenic fetus necessitates conciliation of competing interests. Viviparity evolved with a placenta to mediate the needs of the fetus and maternal adaptation to the demands of pregnancy and to ensure optimal survival for both entities. The maternal-fetal interface is imagined as a 2-dimensional porous barrier between the mother and fetus, when in fact it is an intricate multidimensional array of tissues and resident and circulating factors at play, encompassing the developing fetus, the growing placenta, the changing decidua, and the dynamic maternal cardiovascular system. Pregnancy triggers dramatic changes to maternal hemodynamics to meet the growing demands of the developing fetus. Nearly a century of extensive research into the development and function of the placenta has revealed the role of placental dysfunction in the great obstetrical syndromes, among them preeclampsia. Recently, a debate has arisen questioning the primacy of the placenta in the etiology of preeclampsia, asserting that the maternal cardiovascular system is the instigator of the disorder. It was the clinical observation of the high rate of preeclampsia in hydatidiform mole that initiated the focus on the placenta in the etiology of the disease. Over many years of research, shallow trophoblast invasion with deficient remodeling of the maternal spiral arteries into vessels of higher capacitance and lower resistance has been recognized as hallmarks of the preeclamptic milieu. The lack of the normal decrease in uterine artery resistance is likewise predictive of preeclampsia. In abdominal pregnancies, however, an extrauterine pregnancy develops without remodeling of the spiral arteries, yet there is reduced resistance in the uterine arteries and distant vessels, such as the maternal ophthalmic arteries. Proponents of the maternal cardiovascular model of preeclampsia point to the observed maternal hemodynamic adaptations to pregnancy and maladaptation in gestational hypertension and preeclampsia and how the latter resembles the changes associated with cardiac disease states. Recognition of the importance of the angiogenic-antiangiogenic balance between placental-derived growth factor and its receptor soluble fms-like tyrosine kinase-1 and disturbance in this balance by an excess of a circulating isoform, soluble fms-like tyrosine kinase-1, which competes for and disrupts the proangiogenic receptor binding of the vascular endothelial growth factor and placental-derived growth factor, opened new avenues of research into the pathways to normal adaptation of the maternal cardiovascular and other systems to pregnancy and maladaptation in preeclampsia. The significance of the "placenta vs heart" debate goes beyond the academic: understanding the mutuality of placental and maternal cardiac etiologies of preeclampsia has far-reaching clinical implications for designing prevention strategies, such as aspirin therapy, prediction and surveillance through maternal hemodynamic studies or serum placental-derived growth factor and soluble fms-like tyrosine kinase-1 testing, and possible treatments to attenuate the effects of insipient preeclampsia on women and their fetuses, such as RNAi therapy to counteract excess soluble fms-like tyrosine kinase-1 produced by the placenta. In this review, we will present an integrated model of the maternal-placental-fetal array that delineates the commensality among the constituent parts, showing how a disruption in any component or nexus may lead to the multifaceted syndrome of preeclampsia.

Diagnostic Potential of Exosomal HypoxamiRs in the Context of Hypoxia-Sumoylation-HypoxamiRs in Early Onset Preeclampsia at the Preclinical Stage

As the search for non-invasive preclinical markers of preeclampsia (PE) expands, the number of studies on the diagnostic potential of exosomes is growing. Changes in the partial pressure of oxygen caused by impaired uteroplacental perfusion in PE are a powerful inducer of increased production and release of exosomes from cells, which also determine their cargo. At the same time, the expression pattern of oxygen-dependent microRNAs (miRNAs), called "hypoxamiRs", is modulated, and their packing into exosomes is strictly regulated by sumoylation. In connection therewith, we emphasize the evaluation of exosomal hypoxamiR expression (miR-27b-3p, miR-92b-3p, miR-181a-5p, and miR-186-5p) using quantitative RT-PCR, as well as SUMO 1-4 and UBC9 (by Western blotting), in pregnant women with early-onset PE. The findings show that miR-27b-3p and miR-92b-3p expression was significantly changed at 11-14 and 24-26 weeks of gestation in the blood plasma of pregnant women with early-onset PE, which subsequently manifested. High sensitivity and specificity (AUC = 1) were demonstrated for these miRNAs in the first trimester, and significant correlations with a decrease in hemoglobin (r = 0.71, p = 0.002; r = -0.71, p = 0.002) were established. In mid-pregnancy, the miR-27b-3p expression was found to correlate with an increase in platelets (r = -0.95, p = 0.003), and miR-92b-3p was associated with a decrease in the prothrombin index (r = 0.95, p = 0.003). Specific exomotifs of studied miRNAs were also identified, to which the sumoylated ribonucleoprotein hnRNPA2/B1 binds, carrying out their packaging into exosomes. The expression of conjugated SUMO 1 (p = 0.05), SUMO 2/3/4 (p = 0.03), and UBC9 (p = 0.1) was increased in exosomes at early-onset PE, and the expression of free SUMO 1 (p = 0.03) and SUMO 2/3/4 (p = 0.01) was significantly increased in the placenta, as an adaptive response to hypoxia. Moreover, SUMO 2/3/4 was negatively correlated with miR-27b-3p expression in the placenta. In conclusion, the diagnostic potential of exosomal hypoxamiRs mediated by sumoylation may form the basis for the development of combined specific targets for the treatment of early-onset PE, as hnRNPA2/B1 is a target of miR-27b-3p, and its sumoylation creates miR-27b-3p-hnRNPA2/B1-SUMO 1-4 cross-talk.

Diagnostic and Therapeutic Potential of Extracellular Vesicles

Extracellular vesicles (EVs) are naturally phospholipid enclosed nanovesicles released by many cells in the body. They are stable in circulation, have low immunogenicity, and act as carriers for functionally active biological molecules. They interact with target organs and bind to the receptors. Their target specificity is important to use EVs as noninvasive diagnostic and prognostic tools. EVs play a vital role in normal physiology and cellular communication. They are known to protect their cargo from degradation, which makes them important drug carriers for targeted drug delivery. Using EVs with markers and tracking their path in systemic circulation can be revolutionary in using them as diagnostic tools. We will discuss the scope of this in this paper. Although there are limitations in EVs isolation and storage, their high biocompatibility will fuel more innovations to overcome these challenges.

Disruption of the Blood-Brain Barrier by Extracellular Vesicles From Preeclampsia Plasma and Hypoxic Placentae: Attenuation by Magnesium Sulfate

[Figure: see text].

Angiogenic Properties of Placenta-Derived Extracellular Vesicles in Normal Pregnancy and in Preeclampsia

Angiogenesis is one of the main processes that coordinate the biological events leading to a successful pregnancy, and its imbalance characterizes several pregnancy-related diseases, including preeclampsia. Intracellular interactions via extracellular vesicles (EVs) contribute to pregnancy's physiology and pathophysiology, and to the fetal-maternal interaction. The present review outlines the implications of EV-mediated crosstalk in the angiogenic process in healthy pregnancy and its dysregulation in preeclampsia. In particular, the effect of EVs derived from gestational tissues in pro and anti-angiogenic processes in the physiological and pathological setting is described. Moreover, the application of EVs from placental stem cells in the clinical setting is reported.

Ceramide-Induced Lysosomal Biogenesis and Exocytosis in Early-Onset Preeclampsia Promotes Exosomal Release of SMPD1 Causing Endothelial Dysfunction

Aberrant ceramide build-up in preeclampsia, a serious disorder of pregnancy, causes exuberant autophagy-mediated trophoblast cell death. The significance of ceramide accumulation for lysosomal biogenesis in preeclampsia is unknown. Here we report that lysosome formation is markedly increased in trophoblast cells of early-onset preeclamptic placentae, in particular in syncytiotrophoblasts. This is accompanied by augmented levels of transcription factor EB (TFEB). In vitro and in vivo experiments demonstrate that ceramide increases TFEB expression and nuclear translocation and induces lysosomal formation and exocytosis. Further, we show that TFEB directly regulates the expression of lysosomal sphingomyelin phosphodiesterase (L-SMPD1) that degrades sphingomyelin to ceramide. In early-onset preeclampsia, ceramide-induced lysosomal exocytosis carries L-SMPD1 to the apical membrane of the syncytial epithelium, resulting in ceramide accumulation in lipid rafts and release of active L-SMPD1 via ceramide-enriched exosomes into the maternal circulation. The SMPD1-containing exosomes promote endothelial activation and impair endothelial tubule formation in vitro. Both exosome-induced processes are attenuated by SMPD1 inhibitors. These findings suggest that ceramide-induced lysosomal biogenesis and exocytosis in preeclamptic placentae contributes to maternal endothelial dysfunction, characteristic of this pathology.

Shedding light on the pathophysiology of preeclampsia-syndrome in the era of Cardio-Obstetrics: Role of inflammation and endothelial dysfunction

:

Preeclampsia (PE) is a worldwide pregnancy complication with serious maternal and neonatal consequences. Our understanding of PE pathophysiology has significantly evolved over the last decades by recognizing that endothelial dysfunction and systemic inflammation, with an associated angiogenic imbalance, are key pieces of this still incomplete puzzle. In the present era, where no single treatment to cure or treat this obstetric condition has been developed so far, PE prevention and early prediction poses the most useful clinical approach to reduce the PE burden. Although most PE episodes occur in healthy nulliparous women, the identification of specific clinical conditions that increase dramatically the risk of PE provides a critical opportunity to improve outcomes by acting on potential reversible factors, and also contribute to better understand this pathophysiologic enigma. In this review, we highlight major clinical contributors of PE and shed light about their potential link with endothelial dysfunction and inflammation.

Donor-specific phenotypic variation in hiPSC cardiomyocyte-derived exosomes impacts endothelial cell function

Exosomes are an important mechanism of cell-cell interaction in the cardiovascular system, both in maintaining homeostasis and in stress response. Interindividual differences that alter content in exosomes may play a role in cardiovascular disease pathology. To study the effect of interindividual cardiomyocyte (CM) variation, we characterized exosomal content in phenotypically diverse human induced pluripotent stem cell-derived CMs (hiPSC-CMs). Cell lines were generated from six participants in the HyperGEN cohort: three with left ventricular hypertrophy (LVH) and three with normal left ventricular mass (LVM). Sequence analysis of the intracellular and exosomal RNA populations showed distinct expression pattern differences between hiPSC-CM lines derived from individuals with LVH and those with normal LVM. Functional analysis of hiPSC-endothelial cells (hiPSC-ECs) treated with exosomes from both hiPSC-CM groups showed significant variation in response, including differences in tube formation, migration, and proliferation. Overall, treatment of hiPSC-ECs with exosomes resulted in significant expression changes associated with angiogenesis and endothelial cell vasculogenesis. However, the hiPSC-ECs treated with exosomes from the LVH-affected donors exhibited significantly increased proliferation but decreased tube formation and migration, suggesting angiogenic dysregulation.NEW & NOTEWORTHY The intracellular RNA and the miRNA content in exosomes are significantly different in hiPSC-CMs derived from LVH-affected individuals compared with those from unaffected individuals. Treatment of endothelial cells with these exosomes functionally affects cellular phenotypes in a donor-specific manner. These findings provide novel insight into underlying mechanisms of hypertrophic cell signaling between different cell types. With a growing interest in stem cells and exosomes for cardiovascular therapeutic use, this also provides information important for regenerative medicine.

Improved placental vascular repair in a rat preeclampsia model by implantation of endothelial progenitor cells treated with platelet microparticles

Objective: To detect the role of endothelial progenitor cells (EPCs) treated with platelet microparticles (PMPs) in preeclampsia. Methods: EPCs treated with/without PMPs were labeled and injected to PE rats. The differentiation of EPCs, the change of endothelial nitric oxide synthase (eNOS), blood pressure and proteinuria were measured. The blood pressure and proteinuria increased in each of PE groups, and were improved by EPCs which was strengthened by PMPs. Transplantation of EPCs increased placental angiogenesis. The trend of change of NO was the same as blood pressure. Conclusion: Transplantation of EPCs treated with PMPs improved blood pressure and proteinuria more effectively.

MiRNAs Regulating Oxidative Stress: A Correlation with Doppler Sonography of Uteroplacental Complex and Clinical State Assessments of Newborns in Fetal Growth Restriction

Overproduction of reactive oxygen species (ROS) and, as a result, uncontrolled oxidative stress (OS) can play a central role in disorders of fetal hemodynamics and subsequent development of adverse perinatal outcomes in newborns with fetal growth restriction (FGR). Given the epigenetic nature of such disorders, the aim of our study was to evaluate the expression of miRNAs associated with OS and endothelial dysfunction (miR-27a-3p, miR-30b-5p, miR-125b-5p, miR-221-3p, miR-451a and miR-574-3p) in umbilical cord blood using real-time quantitative RT-PCR. ΜiRNA expression was evaluated in patients with FGR delivery before (n = 9 pregnant) and after 34 weeks of gestation (n = 13 pregnant), and the control groups corresponding to the main groups by gestational age (13 pregnant women in each group, respectively). A significant increase in miR-451a expression was detected in late-onset FGR and correlations with fetoplacental and cerebral circulation were established (increase of resistance in the umbilical artery (pulsatility index, PI UA (umbilical artery): r = −0.59, p = 0.001) and a decrease in cerebral blood flow (CPR: r = 0.48, p = 0.009)). The change in miR-125b-5p expression in the placenta is associated with reduced Doppler of cerebral hemodynamics (CPR: r = 0.73, p = 0.003; PI MCA (middle cerebral artery): r = 0.79, p = 0.0007), and newborn weight (r = 0.56, p = 0.04) in early-onset FGR. In addition, significant changes in miR-125b-5p and miR-451a expression in umbilical cord blood plasma were found in newborns with neonatal respiratory distress syndrome (NRDS) (in early-onset FGR) and very low birth weight (VLBW) (in late-onset FGR). A number of key signaling pathways have been identified in which the regulation of the studied miRNAs is involved, including angiogenesis, neurotrophin signaling pathway and oxidative stress response. In general, our study showed that changes of the redox homeostasis in the mother-placenta-fetus system in FGR and subsequent perinatal outcomes may be due to differential expression of oxidative stress-associated miRNAs.

Vascular mechanisms and molecular targets in hypertensive pregnancy and preeclampsia

Preeclampsia is a major complication of pregnancy manifested as hypertension and often intrauterine growth restriction, but the underlying pathophysiological mechanisms are unclear. Predisposing genetic and environmental factors cause placental maladaptations leading to defective placentation, apoptosis of invasive cytotrophoblasts, inadequate expansive remodeling of the spiral arteries, reduced uteroplacental perfusion pressure, and placental ischemia. Placental ischemia promotes the release of bioactive factors into the maternal circulation, causing an imbalance between antiangiogenic soluble fms-like tyrosine kinase-1 and soluble endoglin and proangiogenic vascular endothelial growth factor, placental growth factor, and transforming growth factor-β. Placental ischemia also stimulates the release of proinflammatory cytokines, hypoxia-inducible factor, reactive oxygen species, and angiotensin type 1 receptor agonistic autoantibodies. These circulating factors target the vascular endothelium, causing generalized endotheliosis in systemic, renal, cerebral, and hepatic vessels, leading to decreases in endothelium-derived vasodilators such as nitric oxide, prostacyclin, and hyperpolarization factor and increases in vasoconstrictors such as endothelin-1 and thromboxane A₂. The bioactive factors also target vascular smooth muscle and enhance the mechanisms of vascular contraction, including cytosolic Ca²⁺, protein kinase C, and Rho-kinase. The bioactive factors could also target matrix metalloproteinases and the extracellular matrix, causing inadequate vascular remodeling, increased arterial stiffening, and further increases in vascular resistance and hypertension. As therapeutic options are limited, understanding the underlying vascular mechanisms and molecular targets should help design new tools for the detection and management of hypertension in pregnancy and preeclampsia.

Exosome Derived from Coronary Serum of Patients with Myocardial Infarction Promotes Angiogenesis Through the miRNA-143/IGF-IR Pathway

Purpose

Myocardial ischemia-reperfusion injury primarily causes myocardial infarction (MI), which is manifested by cell death. Angiogenesis is essential for repair and regeneration in cardiac tissue after MI. In this study, we aimed to investigate the effect of exosomes derived from the serum of MI patients in angiogenesis and its related mechanism.

Patients and Methods

Exosomes, isolated from serum, were collected from MI (MI-exosome) and control (Con-exosome) patients. After coculturing with human umbilical vein endothelial cells, MI-exosome promoted cell proliferation, migration, and tube formation.

Results

The results revealed that the production and release of MI-exosome were associated with cardiomyocytes. Moreover, microarray assays demonstrated that miRNA-143 was significantly decreased in MI-exosome. Meanwhile, the overexpression and knockdown of miRNA-143 could inhibit and enhance angiogenesis, respectively. Furthermore, the effect of exosomal miRNA-143 on angiogenesis was mediated by its targeting gene, insulin-like growth factor 1 receptor (IGF-IR), and was associated with the production of nitric oxide (NO).

Conclusion

Taken together, exosomes derived from the serum of patients with MI promoted angiogenesis through the IGF-IR/NO signaling pathway. The results provide novel understanding of the function of exosomes in MI.

Transfection of maternal cells with placental extracellular vesicles in preeclampsia

The role of extracellular vesicles is widely studied. As well as other organs, placenta produces extracellular vesicles during both, normal and pathological pregnancies. During pregnancy, placental/fetal free DNA circulates in maternal blood. Concentrations of free placental DNA are much higher when pregnancy complications of various etiologies occur. Such a complication could be preeclampsia. In our previous animal model, administration of pure DNA isolated from fetus did not induce any prenatal complications. Here we hypothesize that in real life during preeclampsia or other pregnancy complications, placental DNA might be transported by extracellular vesicles to maternal cells. Also, our preliminary data prove that placental DNA is present in circulating exosomes in maternal blood. Therefore, a lipid bilayer of extracellular vesicles could protect DNA from degradation by enzymes. Extracellular vesicles tend to merge with other cells, therefore, following expression of fetal genes from placental extracellular vesicles in maternal cells could lead to an immune response already observed in pregnancy complications. Future studies should be mainly focused on verification of our hypothesis and evaluate the potential of placental/fetal extracellular vesicles and their gene transfer in preeclampsia or other pregnancy complications.

Extracellular Vesicles as Signaling Mediators and Disease Biomarkers across Biological Barriers

Extracellular vesicles act as shuttle vectors or signal transducers that can deliver specific biological information and have progressively emerged as key regulators of organized communities of cells within multicellular organisms in health and disease. Here, we survey the evolutionary origin, general characteristics, and biological significance of extracellular vesicles as mediators of intercellular signaling, discuss the various subtypes of extracellular vesicles thus far described and the principal methodological approaches to their study, and review the role of extracellular vesicles in tumorigenesis, immunity, non-synaptic neural communication, vascular-neural communication through the blood-brain barrier, renal pathophysiology, and embryo-fetal/maternal communication through the placenta.

Protein Profile Changes in Circulating Placental Extracellular Vesicles in Term and Preterm Births: A Longitudinal Study

Spontaneous preterm birth (PTB) is a major obstetrical problem around the globe and the mechanisms leading to PTB are unclear. Recently, changes in the circulating levels of placental extracellular vesicles (EVs) during pregnancy have been associated with various pregnancy complications. However, progress in the field is hindered by the inability to isolate placental EVs from the maternal circulation. A longitudinal study design was used to determine the protein cargo present in circulating placental EVs in maternal plasma of term and PTB across gestation (ie, first, second, and third trimester). Placental-derived EVs were enriched from the total EV population based on their expression of membrane-bound placental alkaline phosphatase (PLAP). A quantitative, information-independent acquisition (sequential windowed acquisition of all theoretical mass spectra [SWATH]) approach identified and quantified the placental EV protein contents. PLAP+ EVs did not change in characteristics (size, shape, and markers) but did differ in numbers across gestation with low levels in PTB. A comparison analysis between the PLAP+ EV proteome from term and PTB revealed 96 proteins differing significantly (P < 0.05, false discovery rate 1%) across gestation. Bioinformatics analysis of differentially expressed proteins revealed consistent upregulation of inflammatory pathways in both upregulation of epithelial mesenchymal transition pathways at term and downregulation of coagulation/complement activation in preterm. Characterization of the proteomic profile in PLAP+ EVs across gestation demonstrates dramatic changes, which might be used to understand the biological process associated with early parturition and develop biomarkers for predicting high-risk status for PTB.

Deficiency of DICER reduces the invasion ability of trophoblasts and impairs the pro-angiogenic effect of trophoblast-derived microvesicles

DICER is a key rate‐limiting enzyme in the canonical miRNAs biogenesis pathway, and DICER and DICER‐dependent miRNAs have been proved to play essential roles in many physiological and pathological processes. However, whether DICER is involved in placentation has not been studied. Successful spiral artery remodelling is one of the key milestones during placentation, which depends mostly on the invasion of trophoblasts and the crosstalk between trophoblasts and endothelial cells. In the present study, we show that DICER knockdown impairs the invasion ability of both primary extravillous trophoblasts (EVT) and HTR8/SVneo (HTR8) cell lines. The decreased invasion of HTR8 cells upon DICER knockdown (sh‐Dicer) was partly due to the up‐regulation of miR‐16‐2‐3p, which led to a reduced expression level of the collagen type 1 alpha 2 chain (COL1A2) protein. Moreover, microvesicles (MVs) can be secreted by HTR8 cells and promote the tube formation ability of human umbilical cord vein endothelial cells (HUVECs). However, conditioned medium and MVs derived from sh‐Dicer HTR8 cells have an anti‐angiogenic effect, due to reduced angiogenic factors and increased anti‐angiogenic miRNAs (including let‐7d, miR‐1‐6‐2 and miR‐15b), respectively. In addition, reduced protein expression of DICER is found in PE placenta by immunoblotting and immunohistochemistry. In summary, our study uncovered a novel DICER‐miR‐16‐2‐COL1A2 mediated pathway involved in the invasion ability of EVT, and DICER‐containing MVs mediate the pro‐angiogenic effect of trophoblast‐derived conditioned medium on angiogenesis, implying the involvement of DICER in the pathogenesis of PE.

Extracellular Vesicles in Feto-Maternal Crosstalk and Pregnancy Disorders

Extracellular vesicles (EVs) actively participate in inter-cellular crosstalk and have progressively emerged as key players of organized communities of cells within multicellular organisms in health and disease. For these reasons, EVs are attracting the attention of many investigators across different biomedical fields. In this scenario, the possibility to study specific placental-derived EVs in the maternal peripheral blood may open novel perspectives in the development of new early biomarkers for major obstetric pathological conditions. Here we reviewed the involvement of EVs in feto–maternal crosstalk mechanisms, both in physiological and pathological conditions (preeclampsia, fetal growth restriction, preterm labor, gestational diabetes mellitus), also underlining the usefulness of EV characterization in maternal–fetal medicine.

Exosomes Could Offer New Options to Combat the Long-Term Complications Inflicted by Gestational Diabetes Mellitus

Gestational diabetes Mellitus (GDM) is a complex clinical condition that promotes pelvic floor myopathy, thus predisposing sufferers to urinary incontinence (UI). GDM usually regresses after birth. Nonetheless, a GDM history is associated with higher risk of subsequently developing type 2 diabetes, cardiovascular diseases (CVD) and UI. Some aspects of the pathophysiology of GDM remain unclear and the associated pathologies (outcomes) are poorly addressed, simultaneously raising public health costs and diminishing women's quality of life. Exosomes are small extracellular vesicles produced and actively secreted by cells as part of their intercellular communication system. Exosomes are heterogenous in their cargo and depending on the cell sources and environment, they can mediate both pathogenetic and therapeutic functions. With the advancement in knowledge of exosomes, new perspectives have emerged to support the mechanistic understanding, prediction/diagnosis and ultimately, treatment of the post-GMD outcomes. Here, we will review recent advances in knowledge of the role of exosomes in GDM and related areas and discuss the possibilities for translating exosomes as therapeutic agents in the GDM clinical setting.

Unique microRNA Signals in Plasma Exosomes from Pregnancies Complicated by Preeclampsia

Although preeclampsia is a common and serious complication of pregnancy, insight into its pathobiology and diagnosis is lacking. Circulating plasma exosomes, which contain RNA and other molecules and have recently become accessible for diagnostics, may be informative in this regard. We tested the hypothesis that preeclampsia may affect the miRNA cargo within circulating maternal blood exosomes. We collected plasma from 60 pregnant women at term, including 20 women with pregnancy complicated by preeclampsia, and 20 women with fetal growth restriction and 20 with healthy pregnancy, serving as controls. We isolated exosomes from the maternal plasma by continuous density gradient ultracentrifugation. Our main outcome variable was exosomal miRNA cargo, analyzed by quantitative polymerase chain reaction-based TaqMan advanced miRNA assay in a card format and the expression of differentially expressed exosomal miRNA in whole plasma from the same participants. We found that 7 miRNA species were differentially expressed in exosomes from women with preeclampsia and those from controls. In contrast, there was no significant difference in exosomal miRNA expression between women with fetal growth restriction and controls. The results were not affected by fetal sex. Only one of the preeclampsia-related, differentially expressed exosomal miRNAs was significantly different in whole plasma miRNA analysis. We concluded that unlike whole plasma miRNA, exosomes extracted from the plasma of women with preeclampsia exhibit a unique miRNA profile, suggesting that plasma exosomal miRNA could provide insight into the pathophysiology of preeclampsia, and may play a role in disease diagnostics.

Exosomal encapsulation of miR-125a-5p inhibited trophoblast cell migration and proliferation by regulating the expression of VEGFA in preeclampsia

This study is aimed to examine the association between umbilical cord blood (UCB) derived exosomal microRNA (miRNA) with preeclampsia (PE) and to further explore the mechanism of a key differential gene (hsa-miR-125a-5p) in preeclampsia. Umbilical cord blood exosomal miRNA(exo-miRNA) from normal pregnant women and pregnant women with preeclampsia was processed via miRNA sequencing. Quantitative real-time polymerase chain reaction (QRT-PCR) was performed to assess the expression of miR-125a-5p in normal and PE placental tissues and peripheral blood derived exosomes in the third trimester. Human trophoblast cell line HTR8/SVneo was assigned as the negative control and miR-125a-5p mimics. QRT-PCR and Western blot were performed to identify the expressions of miR-125a-5p and vascular endothelial growth factor A (VEGFA). CCK8, flow cytometry, wound-healing and Transwell assays were used to analyze the effect of miR-125a-5p on HTR8/SVneo cell migration, proliferation, and cycle distribution. Tube formation was performed to estimate the angiogenesis ability of miR-125a-5p on HUVECs. In conclusion, miR-125a-5p expression in PE placental tissues was higher than in normal subjects, while the expression of VEGFA was lower in PE placental tissues. We then compared the miR-125a-5p mimics group with the negative control group and found that in the mimics group, the cell migration, proliferation and angiogenesis abilities were decreased, and more cells were arrested in the S stage. Our study systematically profiled the UCB exo-miRNA in normal and PE pregnant women and demonstrated that dysregulation of miR-125a-5p might affect HTR8/SVneo cell proliferation and migration and inhibit angiogenesis by regulating VEGFA, indicating that miR-125a-5p is involved in the progression of PE.

Aspirin for prevention of preeclampsia and fetal growth restriction

For the past decades, growing attention has been given to aspirin use during pregnancy. It favors placentation by its proangiogenic, antithrombotic, and anti-inflammatory effects. Therefore, low doses of aspirin are prescribed in the prevention of placenta-mediated complications, mainly preeclampsia and fetal growth restriction. However, questions regarding its clinical application are still debated. Aspirin is effective in preventing preeclampsia in a high-risk population. Most guidelines recommend that risk stratification should rely on medical history. Nevertheless, screening performances dramatically improve if biochemical and biophysical markers are included. Concerning the appropriate timing and dose, latest studies suggest aspirin should be started before 16 weeks of pregnancy and at a daily dose of 100 mg or more. Further studies are needed to improve the identification of patients likely to benefit from prophylactic aspirin. Besides, the role of aspirin in the prevention of fetal growth restriction is still questioned.

miR-215-5p decreases migration and invasion of trophoblast cells through regulating CDC6 in preeclampsia

Preeclampsia (PE) is a serious disease that occurs after 20 weeks during pregnancy. There are some aberrant microRNAs (miRNAs) that are associated with the etiology of PE. As discovered by scholars, there was an increased level of miR-215-5p in plasma of PE patients compared with the control group; nonetheless, there is still no knowledge of the mechanism of miR-215-5p in PE. We carried out the comparison of the expression levels of miR-215-5p, and the supposed target gene cell division cycle 6 (CDC6) in 30 placentas from PE patients as well as 30 placentas from normal pregnant women. The verification of the impacts of miR-215-5p and CDC6 was carried out by functional assays in HTR-8/SVneo cells transfected with the miR-215-5p mimic or siR-CDC6. As indicated by findings, miR-215-5p showed an apparent increase; conversely, CDC6 was inhibited in the experiment group. The upregulation of miR-215-5p inhibited both the migration and invasive potential of trophoblasts, besides decreasing the G1-S transition and downregulating CDC6 in HTR-8/SVneo cells; nonetheless, it did not significantly impact the cell proliferation. Furthermore, siR-CDC6 replicated the functions of the miR-215-5p mimic. Also, the miR-215-5p mimic and siR-CDC6 both decreased the epithelial-mesenchymal transition (EMT) with additional E-cadherin level and decreased the expressions of N-cadherin as well as vimentin in trophoblast cells. To conclude, miR-215-5p decreased not only the migration but also the invasion of trophoblasts through regulating CDC6, which indicated that miR-215-5p might be associated with the etiology of PE. SIGNIFICANCE OF THE STUDY: More and more attention has been paid on the roles of miRNAs in the pathogenesis of PE. However, there is no study of miR-215-5p in the etiology of PE. We first investigated the mechanism of miR-215-5p in placental tissues and HTR-8/SVneo cells. It was suggested that miR-215-5p decreased the abilities of migration and invasion of trophoblasts through regulating CDC6 in PE. miR-215-5p might be used as an target for the early diagnosis and treatment of PE in the future.

Advance of Stem Cell Treatment for Traumatic Brain Injury

Traumatic brain injury (TBI) is an important cause of human mortality and morbidity, which can induce serious neurological damage. At present, clinical treatments for neurological dysfunction after TBI include hyperbaric oxygen, brain stimulation and behavioral therapy, but the therapeutic effect is not satisfactory. Recent studies have found that exogenous stem cells can migrate to damaged brain tissue, then participate in the repair of damaged brain tissue by further differentiation to replace damaged cells, while releasing anti-inflammatory factors and growth factors, thereby significantly improving neurological function. This article will mainly review the effects, deficiencies and related mechanisms of different types of stem cells in TBI.