Preeclampsia and Extracellular Vesicles

Platelet and mitochondrial RNA is decreased in plasma-derived extracellular vesicles in women with preeclampsia-an exploratory study

BACKGROUND

Circulating extracellular vesicles (EVs) are increased in preeclampsia (PE) and are associated with severity and progression. We examined in this exploratory cohort study if the mRNAs and long noncoding RNAs (lncRNAs) in plasma-derived EVs were dysregulated in PE compared to normal pregnancy and display different temporal patterns during gestation.

METHODS

We isolated EVs from plasma at weeks 22-24 and 36-38 in women with and without PE (n=7 in each group) and performed RNA-seq, focusing on mRNAs and lncRNAs. We validated highly expressed mitochondrial and platelet-derived RNAs discovered from central pathways in 60 women with/without PE. We examined further one of the regulated RNAs, noncoding mitochondrially encoded tRNA alanine (MT-TA), in leukocytes and plasma to investigate its biomarker potential and association with clinical markers of PE.

RESULTS

We found abundant levels of platelet-derived and mitochondrial RNAs in EVs. Expression of these RNAs were decreased and lncRNAs increased in EVs from PE compared to without PE. These findings were further validated by qPCR for mitochondrial RNAs MT-TA, MT-ND2, MT-CYB and platelet-derived RNAs PPBP, PF4, CLU in EVs. Decreased expression of mitochondrial tRNA MT-TA in leukocytes at 22-24 weeks was strongly associated with the subsequent development of PE.

CONCLUSIONS

Platelet-derived and mitochondrial RNA were highly expressed in plasma EVs and were decreased in EVs isolated from women with PE compared to without PE. LncRNAs were mostly increased in PE. The MT-TA in leukocytes may be a useful biomarker for prediction and/or early detection of PE.

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.

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.

Associations of maternal and placental extracellular vesicle miRNA with preeclampsia

Introduction: Gestational vascular complications (GVCs), including gestational hypertension and preeclampsia, are leading causes of maternal morbidity and mortality. Elevated levels of extracellular vesicles (EVs), in GVC have been linked to vascular injury. This study aims to characterize placental and circulating EV miRNA in GVCs, and explores the involvement of EV-miRNA in GVC, and whether they may be used to distinguish between placental and maternal pathologies. Methods: Blood samples were obtained from 15 non-pregnant (NP), 18 healthy-pregnant (HP), and 23 women with GVC during the third trimester. Placental sections were obtained after caesarian section. Platelet-poor-plasma (PPP) and EV pellets were characterized: EV size/concentration, protein content and miRNA expression were measured by nanoparticle tracking analysis, western blot, nano-string technology and RT-PCR. The effects of EVs on trophoblasts and EC miRNA expression were evaluated. Results: Higher EVs concentrations were observed in HP-PPP and GVC-PPP (p < 0.0001) compared to the NP-PPP. The concentration of large EVs (>100 nm) was higher in PPP and EV pellets of HP and GVC compared to the NP group. EV pellets of pregnant women demonstrated lower expression of exosomal markers CD63/CD81 compared to NP-EVs. GVC-EVs expressed more human placental lactogen (hPL) hormone than HP-EVs, reflecting their placental origin. Screening of miRNAs in EV pellets and in PPP identified certain miRNAs that were highly expressed only in EVs pellets of the HP (13%) and GVC groups (15%), but not in the NP group. Differences were detected in the expression of hsa-miR-16-5p, hsa-miR-210, and hsa-miR-29b-3p. The expression of hsa-miR-16-5p and hsa-miR-210 was low in EV pellets obtained from NP, higher in HP-EVs, and significantly lower in GVC-EVs. Except for hsa-miR-29b-3p, which was upregulated in GVC, no significant differences were found in the levels of other miRNAs in placental sections. Exposure to GVC-EVs resulted in higher expression of hsa-miR-29b-3p compared to cells exposed to HP-EVs in villous trophoblasts, but not in EC. Conclusion: Expression of hsa-miR-16-5p and hsa-miR-210 reflects maternal pathophysiological status, while hsa-miR-29b-3p reflects placental status. These findings suggest that EV-miRNA are involved in GVC, and that they may be used to distinguish between pathologies of placental and maternal origins in preeclampsia.

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

[Figure: see text].

Etiological Value of Sterile Inflammation in Preeclampsia: Is It a Non-Infectious Pregnancy Complication?

Understanding of sterile inflammation and its associated biological triggers and diseases is still at the elementary stage. This becomes more warranted in cases where infections are not associated with the pathology. Detrimental effects of bacterial and viral infections on the immune responses at the maternal-fetal interface as well as pregnancy outcomes have been well documented. However, an infection-induced etiology is not thought to be a major contributing component to severe pregnancy complications such as preeclampsia (PE) and gestational diabetes. How is then an inflammatory signal thought to be associated with these pregnancy complications? It is not clear what type of inflammation is involved in the onset of PE-like features. We opine that sterile inflammation regulated by the inflammasome-gasdermins-caspase-1 axis is a contributory factor to the onset of PE. We hypothesize that increased production and release of damage-associated molecular patterns (DAMPs) or Alarmins such as high-mobility group box1 (HMGB1), cell-free fetal DNA, uric acid, the NOD-like receptor pyrin-containing receptor 3 (NLRP3) inflammasome, IL-1β and IL-18 occur in the PE placenta. Some of these molecules have already been observed in the placenta from women with PE. Mechanistically, emerging evidence has demonstrated that excessive placental endoplasmic reticulum (ER) stress, impaired autophagy and gasdermine D (GSDMD)-mediated intrinsic pyroptosis are key events that contribute to systemic sterile inflammation in patients with PE, especially early-onset PE (e-PE). In this review, we highlight the advances on the roles of sterile inflammation and inflammatory signaling cascades involving ER stress, autophagy deficiency and pyroptosis in PE pathophysiology. Deciphering the mechanisms underlying these inflammatory pathways may provide potential diagnostic biomarkers and facilitate the development of therapeutic strategies to treat this devastating disease.

Assessment of Placental Extracellular Vesicles-Associated Fas Ligand and TNF-Related Apoptosis-Inducing Ligand in Pregnancies Complicated by Early and Late Onset Preeclampsia

Preeclampsia (PE) is a hypertensive disorder that affects 2-8% of pregnancies and is one of the main causes of fetal, neonatal, and maternal mortality and morbidity worldwide. Although PE etiology and pathophysiology remain unknown, there is evidence that the hyperactivation of maternal immunity cells against placental cells triggers trophoblast cell apoptosis and death. It has also been reported that placenta-derived extracellular vesicles (EV) carry Fas ligand (FasL) and Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and trigger apoptosis in Jurkat T cells. This study aimed to quantify and compare FasL and TRAIL expression in EV derived from cultures of placenta explants from women with PE (early versus late) and women with uncomplicated pregnancies. Also, the study assessed EV capacity to induce apoptosis in Jurkat T cells. The authors isolated EV from placenta explant cultures, quantified FasL and TRAIL using ELISA, and analyzed EV apoptosis-inducing capability by flow cytometry. Results showed increased FasL and TRAIL in EV derived from placenta of women with PE, and increased EV apoptosis-inducing capability in Jurkat T cells. These results offer supporting evidence that EV FasL and TRAIL play a role in the pathophysiology of PE.

The Potential Role of Serum Exosomes in Preeclampsia

Preeclampsia is a serious pregnancy-specific disease that affects about 5%-8% of pregnant women and is the main reason for the increase in maternal and perinatal mortality. Due to unknown etiology, preeclampsia is still the main cause of increased mortality in maternal and perinatal infants, which is mainly manifested by new hypertension after 20 weeks of pregnancy. As the pathogenesis has not been fully elucidated, early diagnosis and full treatment are lacking. Exosomes secreted from the placenta to the peripheral circulation may be involved in the pathogenesis of preeclampsia and can be detected from the plasma of pregnant women after 6 weeks of pregnancy. Related studies have shown that the levels of exosomes in preeclampsia have changed, and the protein and miRNA expression profiles are also different. Therefore, monitoring changes in plasma exosomes and expression profiles may provide new ideas and new perspectives for the prediction, diagnosis and treatment of preeclampsia.

Healthy and preeclamptic pregnancies show differences in Guanylate-Binding Protein-1 plasma levels

The large interferon-inducible anti-angiogenic pro-inflammatory GTPase Guanylate Binding Protein-1 (GBP-1) is produced and secreted by activated endothelial cells and is highly induced by inflammatory cytokines and inhibited by angiogenic growth factors. During pregnancy a generalized mild inflammatory response is observed. During preeclampsia this generalized inflammatory response is even further activated and activation of the endothelium occurs. We hypothesized that GBP-1 is increased in healthy pregnancy and will be even further increased during preeclampsia. In the first experiment, plasma and placentas were collected from healthy and preeclamptic pregnancies. Plasma was also collected from non-pregnant women. For the second experiment longitudinal blood samples from women with a healthy or preeclamptic pregnancy were collected from the end of the first trimester until birth and one sample postpartum. The plasma GBP-1 levels were measured by ELISA and GBP-1 mRNA and protein levels in the placenta were tested by qPCR and immunohistochemistry. During pregnancy higher plasma concentrations of GBP-1 compared with non-pregnant women were observed. Surprisingly, during preeclampsia, plasma GBP-1 levels were lower than in control pregnancies and similar to the level of non-pregnant controls. Placental GBP-1 mRNA levels were not different between healthy and preeclamptic pregnancies and GBP-1 protein was virtually undetectable in the trophoblast by immunohistochemistry in placental tissue. Evaluation of longitudinal samples showed that plasma GBP-1 concentrations increased towards the end of pregnancy in healthy pregnancies, but not in preeclampsia. In line with our hypothesis, we found higher GBP-1 plasma levels during healthy pregnancy. However, plasma GBP-1 did not further increase during preeclampsia, but was stable. Further studies are needed to evaluate why GBP-1 does not increase during preeclampsia.

Overexpressed Hsa_circ_0001326 Contributes to the Decreased Cell Viability in SWAN71 Cells by Regulating MiR-186-5p/p27 Kip1 Axis

Preeclampsia (PE) is a severe pregnancy-specific complication responsible for a majority of maternal and fetal mortality. The dysfunction of trophoblast cells is known to be associated with the etiology of PE. Moreover, elevated expression of hsa_circ_0001326 was found in patients with PE without elucidating specific mechanisms. Thus, this study aimed to investigate the role of hsa_circ_0001326 in the dysfunction of trophoblast cells in vitro. Human trophoblast SWAN71 cells were used in this study. Cell proliferation, apoptosis and cell cycle were detected by 5-ethynyl-2'-deoxyuridine (EdU) staining, cell counting kit-8 assay, Annexin V/propidium iodide (PI) staining and flow cytometry, respectively. Dual luciferase assay was performed to validate the predicted targets. Additionally, Western blot was conducted for protein detection. The results indicated overexpression (OE) of hsa_circ_0001326 remarkably decreased the viability and proliferation of SWAN71 cells. MiR-186-5p was identified as the target of hsa_circ_0001326. Meanwhile, p27 Kip1 was validated as the target of hsa_miR-186-5p. Moreover, the increased apoptosis and decreased migration induced by hsa_circ_0001326 OE were inhibited by p27 Kip1 knockdown. Hsa_circ_0001326 OE upregulated p27 Kip1 and cleaved caspase3 and downregulated CDK2 and cyclin E1 in cells, while these phenomena were reversed by p27 Kip1 knockdown. In addition, hsa_circ_0001326 OE induced G0/G1 cell cycle arrest was also attenuated in the presence of p27 Kip1 knockdown. Taken together, hsa_circ_0001326 OE contributed to the decreased viability of SWAN71 cells by targeting miR-186-5p via upregulation of p27 Kip1. Our findings were helpful to uncover the pathophysiological process of PE, as well as inspire the development of novel targeted therapy against PE.

Exosomes as Biomarkers for Female Reproductive Diseases Diagnosis and Therapy

Cell-cell communication is an essential mechanism for the maintenance and development of various organs, including the female reproductive system. Today, it is well-known that the function of the female reproductive system and successful pregnancy are related to appropriate follicular growth, oogenesis, implantation, embryo development, and proper fertilization, dependent on the main regulators of cellular crosstalk, exosomes. During exosome synthesis, selective packaging of different factors into these vesicles happens within the originating cells. Therefore, exosomes contain both genetic and proteomic data that could be applied as biomarkers or therapeutic targets in pregnancy-associated disorders or placental functions. In this context, the present review aims to compile information about the potential exosomes with key molecular cargos that are dysregulated in female reproductive diseases which lead to infertility, including polycystic ovary syndrome (PCOS), premature ovarian failure (POF), Asherman syndrome, endometriosis, endometrial cancer, cervical cancer, ovarian cancer, and preeclampsia, as well as signaling pathways related to the regulation of the reproductive system and pregnancy outcome during these pathological conditions. This review might help us realize the etiology of reproductive dysfunction and improve the early diagnosis and treatment of the related complications.

Importance of extracellular vesicles in hypertension

Hypertension affects approximately 1.13 billion adults worldwide and is the leading global risk factor for cardiovascular, cerebrovascular, and kidney diseases. There is emerging evidence that extracellular vesicles participate in the development and progression of hypertension. Extracellular vesicles are membrane-enclosed structures released from nearly all types of eukaryotic cells. During their formation, extracellular vesicles incorporate various parent cell components, including proteins, lipids, and nucleic acids that can be transferred to recipient cells. Extracellular vesicles mediate cell-to-cell communication in a variety of physiological and pathophysiological processes. Therefore, studying the role of circulating and urinary extracellular vesicles in hypertension has the potential to identify novel noninvasive biomarkers and therapeutic targets of different hypertension phenotypes. This review discusses the classification and biogenesis of three EV subcategories (exosomes, microvesicles, and apoptotic bodies) and provides a summary of recent discoveries in the potential impact of extracellular vesicles on hypertension with a specific focus on their role in the blood pressure regulation by organs-artery and kidney, as well as renin-angiotensin-system.

Extracellular Vesicles and Preeclampsia: Current Knowledge and Future Research Directions

Preeclampsia (PE) is associated with long-term morbidity in mothers and lifelong morbidities for their children, ranging from cerebral palsy and cognitive delay in preterm infants, to hypertension, diabetes and obesity in adolescents and young adults. There are several processes that are critical for development of materno-fetal exchange, including establishing adequate perfusion of the placenta by maternal blood, and the formation of the placental villous vascular tree. Recent studies provide persuasive evidence that placenta-derived extracellular vesicles (EVs) represent a significant intercellular communication pathway, and that they may play an important role in placental and endothelial cell (both fetal and maternal) function. These functions are known to be altered in PE. EVs can carry and transport a wide range of bioactive molescules that have potential to be used as biomarkers and therapeutic delivery tools for PE. EV content is often parent cell specific, thus providing an insight or "thumbprint" of the intracellular environment of the originating cell (e.g., human placenta). EV have been identified in plasma under both normal and pathological conditions, including PE. The concentration of EVs and their content in plasma has been reported to increase in association with disease severity and/or progression. Placenta-derived EVs have been identified in maternal plasma during normal pregnancy and PE pregnancies. They contain placenta-specific proteins and miRNAs and, as such, may be differentiated from maternally-derived EVs. The aim of this review, thus, is to describe the potential roles of EVs in preecmpatic pregnancies, focussing on EVs secreted from placental cells. The biogenesis, specificity of placental EVs, and methods used to characterise EVs in the context of PE pregnancies will be also discussed.

Endothelial cell disruption drives increased blood-brain barrier permeability and cerebral edema in the Dahl SS/jr rat model of superimposed preeclampsia

Preeclampsia is characterized by increases in blood pressure and proteinuria in late pregnancy, and neurological symptoms can appear in the form of headaches, blurred vision, cerebral edema, and, in the most severe cases, seizures (eclampsia). The causes for these cerebral manifestations remain unknown, so the use of animal models that mimic preeclampsia is essential to understanding its pathogenesis. The Dahl salt-sensitive (Dahl SS/jr) rat model develops spontaneous preeclampsia superimposed on chronic hypertension; therefore, we hypothesized that the Dahl SS/jr rat would display cerebrovascular features similar to those seen in human preeclampsia. Furthermore, we predicted that this model would allow for the identification of mechanisms underlying these changes. The pregnant Dahl SS/jr rat displayed increased cerebral edema and blood-brain barrier disruption despite tighter control of cerebral blood flow autoregulation and vascular smooth muscle myogenic tone. Analysis of cerebral endothelial cell morphology revealed increased opening of tight junctions, basement membrane dissolution, and vesicle formation. RNAseq analysis identified that genes related to endothelial cell tight junctions and blood-brain barrier integrity were differentially expressed in cerebral vessels from pregnant Dahl SS/jr compared with healthy pregnant Sprague Dawley rats. Overall, our data reveal new insights into mechanisms involved in the cerebrovascular dysfunction of preeclampsia.NEW & NOTEWORTHY This study uses the Dahl SS/jr rat as a preclinical model of spontaneous superimposed preeclampsia to demonstrate uncoupling of cerebral vascular permeability and blood-brain barrier disruption from cerebral blood flow autoregulatory dysfunction and myogenic tone. Additionally, the data presented in this study lay the foundational framework on which future experiments assessing specific transcellular transport components such as individual transporter protein expression and components of the vesicular transport system (caveolae) can be built to help reveal a potential direct mechanistic insight into the causes of cerebrovascular complications during preeclamptic pregnancies.

Glycosylated Siglec-6 expression in syncytiotrophoblast-derived extracellular vesicles from preeclampsia placentas

INTRODUCTION

Preeclampsia (PE) is associated with an exaggerated maternal systemic inflammatory response. Throughout gestation, the placenta releases extracellular vesicles through the syncytiotrophoblast layer (STB) into the maternal circulation and this is increased in PE. Expression of Siglec-6, a transmembrane receptor of molecular weight 50 KDa, is upregulated in PE placental tissue.

METHODS

Here we investigated respective abundance of Siglec-6 in PE -and normal pregnancy- (NP) derived placental lysates (PL) and syncytiotrophoblast-derived extracellular vesicles (STBEV). STBEV from PE and NP placentas were isolated through dual-lobe placental perfusion and serial ultracentrifugation. Siglec-6 was characterized by immunohistochemistry, immunoblotting, mass spectrometry (MS), and deglycosylation.

RESULTS

Immunoblotting revealed the expected Siglec-6 (50 KDa) band present in both PE and NP PL, however an additional heavier band was observed at 70 KDa only in PE PL, but not in NP. When interrogating STBEV we saw an absence of the expected 50 KDa band but the 70 KDa was present predominantly only in the PE STBEV. Deglycosylation of PL and STBEV from PE showed that the 70 KDa and the 50 KDa bands were reduced to 48 KDa, suggesting glycosylation. Both 48 KDa and 70 KDa bands were subjected to MS, confirming Siglec-6 expression in both.

DISCUSSION

Our data shows that the inability to detect Siglec-6 in circulation might be due to the placenta secreting STBEV carrying a modified glycosylated form of Siglec-6 with a 70 KDa molecular weight, significantly and uniquely upregulated in PE STBEV.

Mechanisms of Key Innate Immune Cells in Early- and Late-Onset Preeclampsia

Preeclampsia is a complex cardiovascular disorder of pregnancy with underlying multifactorial pathogeneses; however, its etiology is not fully understood. It is characterized by the new onset of maternal hypertension after 20 weeks of gestation, accompanied by proteinuria, maternal organ damage, and/or uteroplacental dysfunction. Preeclampsia can be subdivided into early- and late-onset phenotypes (EOPE and LOPE), diagnosed before 34 weeks or from 34 weeks of gestation, respectively. Impaired placental development in early pregnancy and subsequent growth restriction is often associated with EOPE, while LOPE is associated with maternal endothelial dysfunction. The innate immune system plays an essential role in normal progression of physiological pregnancy and fetal development. However, inappropriate or excessive activation of this system can lead to placental dysfunction or poor maternal vascular adaptation and contribute to the development of preeclampsia. This review aims to comprehensively outline the mechanisms of key innate immune cells including macrophages, neutrophils, natural killer (NK) cells, and innate B1 cells, in normal physiological pregnancy, EOPE and LOPE. The roles of the complement system, syncytiotrophoblast extracellular vesicles and mesenchymal stem cells (MSCs) are also discussed in the context of innate immune system regulation and preeclampsia. The outlined molecular mechanisms, which represent potential therapeutic targets, and associated emerging treatments, are evaluated as treatments for preeclampsia. Therefore, by addressing the current understanding of innate immunity in the pathogenesis of EOPE and LOPE, this review will contribute to the body of research that could lead to the development of better diagnosis, prevention, and treatment strategies. Importantly, it will delineate the differences in the mechanisms of the innate immune system in two different types of preeclampsia, which is necessary for a more personalized approach to the monitoring and treatment of affected women.

microRNA-21 regulates the proliferation of placental cells via FOXM1 in preeclampsia

The present study determined the expression of microRNA (miRNA or miR)-21 and forkhead box M1 (FOXM1) in placenta and blood samples from patients with preeclampsia (PE), and investigated the relationship between miR-21 and FOXM1. A total of 32 pregnant women with PE and 28 healthy pregnant women were included in the study as the experimental and control groups, respectively. Placental tissues and peripheral blood were collected from all subjects. ELISA was performed to measure the level of FOXM1 protein in the blood. HTR8/SVneo cells overexpressing miR-21 were established by transfection with agomiR-21. Reverse transcription-quantitative PCR was performed to measure the expression of FOXM1 mRNA and miR-21 in the placenta, blood and cells, and western blotting was used to evaluate FOXM1 protein expression in the placenta. An MTT assay was also performed to assess cell viability. In addition, a dual-luciferase reporter assay was used to investigate the direct interaction between FOXM1 and miR-21. The occurrence of PE was found to be associated with reduced FOXM1 mRNA levels, and elevated FOXM1 protein expression may serve a regulatory role that when attenuated leads to the occurrence of PE. Furthermore, miR-21 may serve a regulatory role in the pathology of PE by downregulating FOXM1 expression at the transcriptional level. In HTR8/SVneo cells, the overexpression of miR-21 reduced cell viability, possibly via the reduction of FOXM1 expression. The dual-luciferase assay indicated that miR-21 directly binds to the 3'-untranslated region of FOXM1 to regulate its expression. The present study demonstrated that the expression of FOXM1 mRNA and protein is downregulated, whereas the expression of miR-21 is upregulated in the placenta and blood samples of PE patients. In conclusion, miR-21 may regulate placental cell proliferation via its effects on FOXM1 to promote the occurrence and development of PE.

Pathophysiology of the Venous Thromboembolism Risk in Preeclampsia

Preeclampsia complicates up to 8% of pregnancies and is a leading cause of fetomaternal morbidity andmortality. Treatment options are limited, with supportive care and delivery of the placenta representing the cornerstone of current management strategies. Derangements in blood coagulation are wellrecognised in this disorder and appear to favour an increased risk of venous thromboembolism among affected women. This risk appears to be most significant in the postpartum period. The mechanisms underlying this increased thrombosis risk remain to be fully elucidated although increased expression of procoagulant factors, endothelial dysfunction, attenuation of endogenous anticoagulant activity and increased platelet activity have been implicated in the prothrombotic tendency. Preeclampsia is also occasionally complicated by life-threatening haemorrhagic events and current evidence suggests that in some severe manifestations of this disease a coagulopathy with a clinical bleeding tendency may be the predominant haemostatic abnormality. Identifying affected women at significant risk of thrombosis and managing the competing thrombotic and haemorrhagic risks continue to be a significant clinical challenge. Derangements in blood coagulation are also implicated in the pathogenesis of preeclampsia; however, the role of antiplatelet or anticoagulant drugs in the prevention and treatment of this disorder remains a source of considerable debate. In addition, the potential role of specific haemostatic markers as diagnostic or screening tools for preeclampsia has also yet to be determined. Further characterisation of the underlying molecular mechanisms would likely be of major translational relevance and could provide insights into the pathogenesis of this disease as well as the associated haemostatic dysfunction.

[Changes in the indicators of thromboelastography and platelet function in pregnant women with various forms of hypertensive disorders in the third trimester of pregnancy.]

The aim of this research is the study of haemostasis of pregnant women suffering from various forms of hypertensive disorders in their III trimester of pregnancy. 165 women at 26-41 weeks of pregnancy were examined: 22 women had moderate preeclampsia, 31 had severe preeclampsia, 45 women suffered from chronic hypertension, 20 women have developed preeclampsia on the background of chronic hypertension and 47 women had no hypertensive disorders (control group). The hemostasis system has been assessed using the results of the following investigations: thromboelastography, induced platelet aggregation with ADP and adrenaline at a dosage of 1.25 and 2.5 μg/ml respectively and collagen at a dosage of 20 mg/ml, platelet ATP secretion and the average concentration of platelet components. Thromboelastography has been performed using TEG® 5000 thromboelastograph (Haemoscope Corporation, USA). The study of platelet aggregation and platelet ATP secretion has been performed at automatic aggregometer CHRONO-LOG® Model 700 (USA). The mean platelet component concentration has been measured using SIEMENS ADVIA 2120i automated hematology analyzer (Siemens Healthcare Diagnostics Inc., USA). Thromboelastogram analysis showed a decrease in the plasma hemostasis activity in all groups of women with hypertensive disorders. The functional activity of platelets of women with moderate preeclampsia and chronic arterial hypertension did not change in comparison with to the control group. The disorder of dense platelet granules degranulation and decrease in their aggregation ability have been detected in a cohort with severe preeclampsia. The decrease in adrenaline induced platelet aggregation has been noted in the group of women suffering from preeclampsia on the background of chronic arterial hypertension. Thromboelastography analysis (R, K, angle α, TMA, Cl, LY30) may be useful for the differential diagnosis of severe preeclampsia and chronic arterial hypertension. The results of the study led to the conclusion that it is advisable to use low doses of ADP and adrenaline as inducers of platelet aggregation, considering their granulocyticity and the ability to secrete ATP.

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.

Molecular Targets of Aspirin and Prevention of Preeclampsia and Their Potential Association with Circulating Extracellular Vesicles during Pregnancy

Uncomplicated healthy pregnancy is the outcome of successful fertilization, implantation of embryos, trophoblast development and adequate placentation. Any deviation in these cascades of events may lead to complicated pregnancies such as preeclampsia (PE). The current incidence of PE is 2–8% in all pregnancies worldwide, leading to high maternal as well as perinatal mortality and morbidity rates. A number of randomized controlled clinical trials observed the association between low dose aspirin (LDA) treatment in early gestational age and significant reduction of early onset of PE in high-risk pregnant women. However, a substantial knowledge gap exists in identifying the particular mechanism of action of aspirin on placental function. It is already established that the placental-derived exosomes (PdE) are present in the maternal circulation from 6 weeks of gestation, and exosomes contain bioactive molecules such as proteins, lipids and RNA that are a “fingerprint” of their originating cells. Interestingly, levels of exosomes are higher in PE compared to normal pregnancies, and changes in the level of PdE during the first trimester may be used to classify women at risk for developing PE. The aim of this review is to discuss the mechanisms of action of LDA on placental and maternal physiological systems including the role of PdE in these phenomena. This review article will contribute to the in-depth understanding of LDA-induced PE prevention.

Senescent Kidney Cells in Hypertensive Patients Release Urinary Extracellular Vesicles

Background

Hypertension may be associated with renal cellular injury. Cells in distress release extracellular vesicles (EVs), and their numbers in urine may reflect renal injury. Cellular senescence, an irreversible growth arrest in response to a noxious milieu, is characterized by release of proinflammatory cytokines. We hypothesized that EVs released by senescent nephron cells can be identified in urine of patients with hypertension.

Methods and Results

We recruited patients with essential hypertension (EH) or renovascular hypertension and healthy volunteers (n=14 each). Renal oxygenation was assessed using magnetic resonance imaging and blood samples collected from both renal veins for cytokine‐level measurements. EVs isolated from urine samples were characterized by imaging flow cytometry based on specific markers, including p16 (senescence marker), calyxin (podocytes), urate transporter 1 (proximal tubules), uromodulin (ascending limb of Henle's loop), and prominin‐2 (distal tubules). Overall percentage of urinary p16+ EVs was elevated in EH and renovascular hypertension patients compared with healthy volunteers and correlated inversely with renal function and directly with renal vein cytokine levels. Urinary levels of p16⁺/urate transporter 1⁺ were elevated in all hypertensive subjects compared with healthy volunteers, whereas p16⁺/prominin‐2⁺ levels were elevated only in EH versus healthy volunteers and p16⁺/uromodulin⁺ in renovascular hypertension versus EH.

Conclusions

Levels of p16⁺EVs are elevated in urine of hypertensive patients and may reflect increased proximal tubular cellular senescence. In EH, EVs originate also from distal tubules and in renovascular hypertension from Henle's loop. Hence, urinary EVs levels may be useful to identify intrarenal sites of cellular senescence.

Extracellular vesicles generated by placental tissues ex vivo: A transport system for immune mediators and growth factors

PROBLEM

To study the mechanisms of placenta function and the role of extracellular vesicles (EVs) in pregnancy, it is necessary to develop an ex vivo system that retains placental cytoarchitecture and the primary metabolic aspects, in particular the release of EVs and soluble factors. Here, we developed such a system and investigated the pattern of secretion of cytokines, growth factors, and extracellular vesicles by placental villous and amnion tissues ex vivo.

METHODS OF STUDY

Placental villous and amnion explants were cultured for 2 weeks at the air/liquid interface and their morphology and the released cytokines and EVs were analyzed. Cytokines were analyzed with multiplexed bead assays, and individual EVs were analyzed with recently developed techniques that involved EV capture with magnetic nanoparticles coupled to anti-EV antibodies and flow cytometry.

RESULTS

Ex vivo tissues (i) remained viable and preserved their cytoarchitecture; (ii) maintained secretion of cytokines and growth factors; (iii) released EVs of syncytiotrophoblast and amnion epithelial cell origins that contain cytokines and growth factors.

CONCLUSION

A system of ex vivo placental villous and amnion tissues can be used as an adequate model to study placenta metabolic activity in normal and complicated pregnancies, in particular to characterize EVs by their surface markers and by encapsulated proteins. Establishment and benchmarking the placenta ex vivo system may provide new insight in the functional status of this organ in various placental disorders, particularly regarding the release of EVs and cytokines. Such EVs may have a prognostic value for pregnancy complications.

Extracellular Vesicles in Human Reproduction in Health and Disease

Extensive evidence suggests that the release of membrane-enclosed compartments, more commonly known as extracellular vesicles (EVs), is a potent newly identified mechanism of cell-to-cell communication both in normal physiology and in pathological conditions. This review presents evidence about the formation and release of different EVs, their definitive markers and cargo content in reproductive physiological processes, and their capacity to convey information between cells through the transfer of functional protein and genetic information to alter phenotype and function of recipient cells associated with reproductive biology. In the male reproductive tract, epididymosomes and prostasomes participate in regulating sperm motility activation, capacitation, and acrosome reaction. In the female reproductive tract, follicular fluid, oviduct/tube, and uterine cavity EVs are considered as vehicles to carry information during oocyte maturation, fertilization, and embryo-maternal crosstalk. EVs via their cargo might be also involved in the triggering, maintenance, and progression of reproductive- and obstetric-related pathologies such as endometriosis, polycystic ovarian syndrome, preeclampsia, gestational diabetes, and erectile dysfunction. In this review, we provide current knowledge on the present and future use of EVs not only as biomarkers, but also as therapeutic targeting agents, mainly as vectors for drug or compound delivery into target cells and tissues.

Effects of forkhead box protein M1 on trophoblast invasion and its role in preeclampsia development

The present study aimed to investigate the expression of the forkhead box protein M1 (FOXM1) in the placenta of patients with preeclampsia, and its effect on trophoblasts. A total of 28 patients with preeclampsia and 30 patients without preeclampsia (controls) who underwent cesarean section and were admitted to the Affiliated Hospital of Qingdao University between June 2013 and September 2016 were enrolled in the present study. The expression of FOXM1 in placental tissues was examined by reverse transcription-quantitative polymerase chain reaction, western blotting and immunohistochemistry. HTR8/SVneo cells were used to measure the in vitro expression of the vascular endothelial growth factor (VEGF). The results demonstrated that FOXM1 expression was downregulated in the placental tissues of patient with preeclampsia (P<0.05). Following the silencing of FOXM1 expression, the proliferation of HTR8/SVneo cells was suppressed. The results of flow cytometry demonstrated that proportion of HTR8/SVneo cells in the G0/G1 phase and the proportion of apoptotic cells increased. The expression of the apoptosis regulator BCL-2, as well as the expression of VEGF mRNA and protein expression were also downregulated following FOXM1 silencing. FOXM1 may therefore promote the development of preeclampsia via the VEGF signaling pathway.

The impact of circulating preeclampsia-associated extracellular vesicles on the migratory activity and phenotype of THP-1 monocytic cells

Intercellular communication via extracellular vesicles (EVs) and their target cells, especially immune cells, results in functional and phenotype changes that consequently may play a significant role in various physiological states and the pathogenesis of immune-mediated disorders. Monocytes are the most prominent environment-sensing immune cells in circulation, skilled to shape their microenvironments via cytokine secretion and further differentiation. Both the circulating monocyte subset distribution and the blood plasma EV pattern are characteristic for preeclampsia, a pregnancy induced immune-mediated hypertensive disorder. We hypothesized that preeclampsia-associated EVs (PE-EVs) induced functional and phenotypic alterations of monocytes. First, we proved EV binding and uptake by THP-1 cells. Cellular origin and protein cargo of circulating PE-EVs were characterized by flow cytometry and mass spectrometry. An altered phagocytosis-associated molecular pattern was found on 12.5 K fraction of PE-EVs: an elevated CD47 "don't eat me" signal (p < 0.01) and decreased exofacial phosphatidylserine "eat-me" signal (p < 0.001) were found along with decreased uptake of these PE-EVs (p < 0.05). The 12.5 K fraction of PE-EVs induced significantly lower chemotaxis (p < 0.01) and cell motility but accelerated cell adhesion of THP-1 cells (p < 0.05). The 12.5 K fraction of PE-EVs induced altered monocyte functions suggest that circulating EVs may have a role in the pathogenesis of preeclampsia.

Noncoding RNAs Carried by Extracellular Vesicles in Endocrine Diseases

RNA molecules are essential and fine regulators of important biological processes. Their role is well documented also in the endocrine system, both in physiological and pathological conditions. Increasing interest is arising about the function and the importance of noncoding RNAs shuttled by extracellular vesicles (EVs). In fact, EV membrane protects nucleic acids from enzyme degradation. Nowadays, the research on EVs and their cargoes, as well as their biological functions, faces the lack of standardization in EV purification. Here, the main techniques for EV isolation are discussed and compared for their advantages and vulnerabilities. Despite the possible discrepancy due to methodological variability, EVs and their RNA content are reported to be key mediators of intercellular communication in pathologies of main endocrine organs, including the pancreas, thyroid, and reproductive system. In particular, the present work describes the role of RNAs contained in EVs in pathogenesis and progression of several metabolic dysfunctions, including obesity and diabetes, and their related manifestations. Their importance in the establishment and progression of thyroid autoimmunity disorders and complicated pregnancy is also discussed. Preliminary studies highlight the attractive possibility to use RNAs contained in EVs as biomarkers suggesting their exploitation for new diagnostic approaches in endocrinology.

Alterations in antioxidant system, mitochondrial biogenesis and autophagy in preeclamptic myometrium

Preeclampsia is a pregnancy complication which causes significant maternal and fetal morbidity and mortality worldwide. Although intensive research has been performed in the last 40 years, the pathology of preeclampsia is still poorly understood. The present work is a comparative study of the myometrium of women with normal pregnancy, and those with late- and early-onset preeclampsia (n = 10 for each group). We observed significant changes in the levels of antioxidant enzymes, markers of mitochondrial biogenesis and autophagy proteins in preeclamptic myometrium. Levels of superoxide dismutase 1 and catalase were lower in both preeclamptic groups than the control group. In late-onset preeclampsia, expression levels of essential mitochondria-related proteins VDAC1, TFAM, hexokinase 1, PGC-1α and PGC-1β, and autophagy marker LC3A, were significantly elevated. In the myometrium of the early-onset preeclampsia group OPA1 and Bcl-2 were up-regulated compared to those of the control (p < 0.05). These findings suggest that crucial molecular changes in the maternal myometrium occur with the development of preeclampsia.

Cerebrovascular Reactivity and Vascular Activation in Postmenopausal Women With Histories of Preeclampsia

Cerebrovascular reactivity (CVR) is reduced in patients with cognitive decline. Women with a history of preeclampsia are at increased risk for cognitive decline. This study examined an association between pregnancy history and CVR using a subgroup of 40 age- and parity-matched pairs of women having histories of preeclampsia (n=27) or normotensive pregnancy (n=29) and the association of activated blood elements with CVR. Middle cerebral artery velocity was measured by Doppler ultrasound before and during hypercapnia to assess CVR. Thirty-eight parameters of blood cellular elements, microvesicles, and cell-cell interactions measured in venous blood were assessed for association with CVR using principal component analysis. Middle cerebral artery velocity was lower in the preeclampsia compared with the normotensive group at baseline (63±4 versus 73±3 cm/s; P=0.047) and during hypercapnia (P=0.013-0.056). CVR was significantly lower in the preeclampsia compared with the normotensive group (2.1±1.3 versus 2.9±1.1 cm·s·mm Hg; P=0.009). Globally, the association of the 7 identified principal components with preeclampsia (P=0.107) and with baseline middle cerebral artery velocity (P=0.067) did not reach statistical significance. The interaction between pregnancy history and principal components with respect to CVR (P=0.084) was driven by a nominally significant interaction between preeclampsia and the individual principal component defined by blood elements, platelet aggregation, and interactions of platelets with monocytes and granulocytes (P=0.008). These results suggest that having a history of preeclampsia negatively affects the cerebral circulation years beyond the pregnancy and that this effect was associated with activated blood elements.

Characterization of intravascular cellular activation in relationship to subclinical atherosclerosis in postmenopausal women

Objective

Mechanisms and interactions among intravascular cells contributing to development of subclinical atherosclerosis are poorly understood. In women, both menopausal status and pregnancy history influence progression of atherosclerosis. This study examined activation and interactions among blood elements with subclinical atherosclerosis in menopausal women with known pregnancy histories.

Methods

Carotid intima-media thickness (CIMT), as a marker of subclinical atherosclerosis, was measured using B-mode ultrasound in age- and parity-matched women [40 with and 40 without a history of preeclampsia] 35 years after the index pregnancy. Interactions among intravascular cells (38 parameters) were measured by flow cytometry in venous blood. Data analysis was by principal component which retained 7 independent dimensions accounting for 63% of the variability among 38 parameters.

Results

CIMT was significantly greater in women with a history of preeclampsia (P = 0.004). Platelet aggregation and platelet interactions with granulocytes and monocytes positively associated with CIMT in postmenopausal women independent of their pregnancy history (ρ = 0.258, P< 0.05). However, the association of the number of platelets, platelet activation and monocyte-platelet interactions with CIMT differed significantly depending upon pregnancy history (test for interaction, P<0.001).

Conclusion

Interactions among actived intravascular cells and their association with subclinical atherosclerosis differ in women depending upon their pregnancy histories.

Extracellular vesicles in renal disease

Extracellular vesicles, such as exosomes and microvesicles, are host cell-derived packages of information that allow cell-cell communication and enable cells to rid themselves of unwanted substances. The release and uptake of extracellular vesicles has important physiological functions and may also contribute to the development and propagation of inflammatory, vascular, malignant, infectious and neurodegenerative diseases. This Review describes the different types of extracellular vesicles, how they are detected and the mechanisms by which they communicate with cells and transfer information. We also describe their physiological functions in cellular interactions, such as in thrombosis, immune modulation, cell proliferation, tissue regeneration and matrix modulation, with an emphasis on renal processes. We discuss how the detection of extracellular vesicles could be utilized as biomarkers of renal disease and how they might contribute to disease processes in the kidney, such as in acute kidney injury, chronic kidney disease, renal transplantation, thrombotic microangiopathies, vasculitides, IgA nephropathy, nephrotic syndrome, urinary tract infection, cystic kidney disease and tubulopathies. Finally, we consider how the release or uptake of extracellular vesicles can be blocked, as well as the associated benefits and risks, and how extracellular vesicles might be used to treat renal diseases by delivering therapeutics to specific cells.

Extracellular Microvesicles as Game Changers in Better Understanding the Complexity of Cellular Interactions-From Bench to Clinical Applications

Recent research has led to wide acceptance and better understanding of a novel mechanism for cell-cell communication that employs a network of extracellular microvesicles (ExMVs). Derived from the plasma membrane or the endosomal membrane compartment, these small, spherical membrane fragments are secreted from the cell surface or in the process of exocytosis from endosomal membrane compartment and (1) with ligands expressed on their surface directly stimulate target cells in a paracrine manner, (2) transfer cell membrane receptors to target cells or (3) deliver encapsulated messenger RNA, microRNA, proteins and bioactive lipids to target cells. This represents an evolutionarily ancient mechanism by which cells signal their presence in the microenvironment, communicate with each other and affect the biology of neighboring cells. Evidence suggests the pivotal role of ExMVs in almost all biological processes within the body as well as their involvement in certain pathologies. Moreover, liquid biopsies based on deciphering the molecular signature of ExMVs promise to revolutionize laboratory diagnostics. At the same time, there are ongoing attempts to employ them as delivery vehicles for drugs as well as therapeutics in regenerative medicine, oncology and immunotherapy.