Differential response of placental cells to high D-glucose and its impact on extracellular vesicle biogenesis and trafficking via small GTPase Ras-related protein RAB-7A.

Placental extracellular vesicles (EVs) can be found in the maternal circulation throughout gestation, and their concentration, content and bioactivity are associated with pregnancy outcomes, including gestational diabetes mellitus (GDM). However, the effect of changes in the maternal microenvironment on the mechanisms associated with the secretion of EVs from placental cells remains to be fully established. Here, we evaluated the effect of high glucose on proteins associated with the trafficking and release of different populations of EVs from placental cells. BeWo and HTR8/SVneo cells were used as placental models and cultured under 5-mM D-glucose (i.e. control) or 25-mM D-glucose (high glucose). Cell-conditioned media (CCM) and cell lysate were collected after 48 h. Different populations of EVs were isolated from CCM by ultracentrifugation (i.e. pellet 2K-g, pellet 10K-g, and pellet 100K-g) and characterised by Nanoparticle Tracking Analysis. Quantitative proteomic analysis (IDA/SWATH) and multiple reaction monitoring protocols at high resolution (MRMHR) were developed to quantify 37 proteins related to biogenesis, trafficking/release and recognition/uptake of EVs. High glucose increased the secretion of total EVs across the pellets from BeWo cells, an effect driven mainly by changes in the small EVs concentration in the CCM. Interestingly, no effect of high glucose on HTR8/SVneo cells EVs secretion was observed. High glucose induces changes in proteins associated with vesicle trafficking in BeWo cells, including Heat Shock Protein Family A (Hsp70) Member 9 (HSPA9) and Member 8 (HSPA8). For HTR8/SVneo, altered proteins including prostaglandin F2α receptor regulatory protein (FPRP), RAB5A, RAB35, RAB5B, and RB11B, STAM1 and TSG101. These proteins are associated with the secretion and trafficking of EVs, which could explain in part, changes in the levels of circulating EVs in diabetic pregnancies. Further, we identified that proteins RAB11B, PDCD6IP, STAM, HSPA9, HSPA8, SDCBP, RAB5B, RAB5A, RAB7A and ERAP1 regulate EV release in response to high and low glucose when overexpressed in cells. Interestingly, immunohistochemistry analysis of RAB7A revealed distinct changes in placental tissues obtained from women with normal glucose tolerance (NGT, n = 6) and those with GDM (n = 6), influenced by diet or insulin treatment. High glucose regulation of proteins involved in intercellular dynamics and the trafficking of multivesicular bodies to the plasma membrane in placental cells is relevant in the context of GDM pregnancies.

Enhancing precision targeting of ovarian cancer tumor cells in vivo through extracellular vesicle engineering.

Extracellular vesicles (EVs) function as natural mediators of intercellular communication, secreted by cells to facilitate cell-cell signaling. Due to their low toxicity, immunogenicity, biodegradability, and potential to encapsulate therapeutic drugs, EVs hold significant therapeutic promise. Nevertheless, their limited targeting ability often diminishes their therapeutic impact. Therefore, enhancing EVs by incorporating targeting units onto their membranes could bolster their targeting capabilities, enabling them to accumulate in specific cells and tissues. In this study, we engineered EVs to fuse ephrin-B2 with the EV membrane protein LAMP2b. This modification aimed to direct the engineered EVs toward the ephrin-B4 receptor expressed on the surface of ovarian cancer cells. The engineered EVs retained their inherent properties, including size, expression of EV membrane proteins, and morphology, upon isolation. In vitro experiments using real-time imaging revealed that EVs engineered with the ephrin-B2 ligand exhibited substantial internalization and uptake by ovarian cancer cells, in stark contrast to native EVs. In vivo, the engineered EVs carrying the ephrin-B2 ligand effectively targeted ovarian cancer cells, surpassing the targeting efficiency of control EVs. This innovative approach establishes a novel targeting system, enhancing the uptake of EVs by ovarian cancer cells. Our findings underscore the potential of using EVs to target cancer cells, thereby enhancing the effectiveness of anti-cancer therapies while minimizing off-target effects and toxicity in normal cells and organs.

Comprehensive strategy for identifying extracellular vesicle surface proteins as biomarkers for chronic kidney disease.

Chronic kidney disease (CKD) poses a significant health burden worldwide. Especially, obesity-induced chronic kidney disease (OCKD) is associated with a lack of accuracy in disease diagnostic methods. The identification of reliable biomarkers for the early diagnosis and monitoring of CKD and OCKD is crucial for improving patient outcomes. Extracellular vesicles (EVs) have emerged as potential biomarkers in the context of CKD. In this review, we focused on the role of EVs as potential biomarkers in CKD and OCKD and developed a comprehensive list of EV membrane proteins that could aid in the diagnosis and monitoring of the disease. To assemble our list, we employed a multi-step strategy. Initially, we conducted a thorough review of the literature on EV protein biomarkers in kidney diseases. Additionally, we explored papers investigating circulating proteins as biomarkers in kidney diseases. To further refine our list, we utilized the EV database Vesiclepedia.org to evaluate the qualifications of each identified protein. Furthermore, we consulted the Human Protein Atlas to assess the localization of these candidates, with a particular focus on membrane proteins. By integrating the information from the reviewed literature, Vesiclepedia.org, and the Human Protein Atlas, we compiled a comprehensive list of potential EV membrane protein biomarkers for CKD and OCKD. Overall, our review underscores the potential of EVs as biomarkers in the field of CKD research, providing a foundation for future studies aimed at improving CKD and OCKD diagnosis and treatment.

Advances in extracellular vesicles as mediators of cell-to-cell communication in pregnancy.

Cell-to-cell communication mediated by Extracellular Vesicles (EVs) is a novel and emerging area of research, especially during pregnancy, in which placenta derived EVs can facilitate the feto-maternal communication. EVs comprise a heterogeneous group of vesicle sub-populations with diverse physical and biochemical characteristics and originate by specific biogenesis mechanisms. EVs transfer molecular cargo (including proteins, nucleic acids, and lipids) between cells and are critical mediators of cell communication. There is growing interest among researchers to explore into the molecular cargo of EVs and their functions in a physiological and pathological context. For example, inflammatory mediators such as cytokines are shown to be released in EVs and EVs derived from immune cells play key roles in mediating the immune response as well as immunoregulatory pathways. Pregnancy complications such as gestational diabetes mellitus, preeclampsia, intrauterine growth restriction and preterm birth are associated with altered levels of circulating EVs, with differential EV cargo and bioactivity in target cells. This implicates the intriguing roles of EVs in reprogramming the maternal physiology during pregnancy. Moreover, the capacity of EVs to carry bioactive molecules makes them a promising tool for biomarker development and targeted therapies in pregnancy complications. This review summarizes the physiological and pathological roles played by EVs in pregnancy and pregnancy-related disorders and describes the potential of EVs to be translated into clinical applications in the diagnosis and treatment of pregnancy complications.

Chemically-Induced Lipoprotein Breakdown for Improved Extracellular Vesicle Purification.

Extracellular vesicles (EVs) are nanosized biomolecular packages involved in intercellular communication. EVs are released by all cells, making them broadly applicable as therapeutic, diagnostic, and mechanistic components in (patho)physiology. Sample purity is critical for correctly attributing observed effects to EVs and for maximizing therapeutic and diagnostic performance. Lipoprotein contaminants represent a major challenge for sample purity. Lipoproteins are approximately six orders of magnitude more abundant in the blood circulation and overlap in size, shape, and density with EVs. This study represents the first example of an EV purification method based on the chemically-induced breakdown of lipoproteins. Specifically, a styrene-maleic acid (SMA) copolymer is used to selectively breakdown lipoproteins, enabling subsequent size-based separation of the breakdown products from plasma EVs. The use of the polymer followed by tangential flow filtration or size-exclusion chromatography results in improved EV yield, preservation of EV morphology, increased EV markers, and reduced contaminant markers. SMA-based EV purification enables improved fluorescent labeling, reduces interactions with macrophages, and enhances accuracy, sensitivity, and specificity to detect EV biomarkers, indicating benefits for various downstream applications. In conclusion, SMA is a simple and effective method to improve the purity and yield of plasma-derived EVs, which favorably impacts downstream applications.

Genomic communication via circulating extracellular vesicles and long-term health consequences of COVID-19.

COVID-19 continues to affect an unprecedented number of people with the emergence of new variants posing a serious challenge to global health. There is an expansion of knowledge in understanding the pathogenesis of Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and the impact of the acute disease on multiple organs. In addition, growing evidence reports that the impact of COVID-19 on different organs persists long after the recovery phase of the disease, leading to long-term consequences of COVID-19. These long-term consequences involve pulmonary as well as extra-pulmonary sequelae of the disease. Noteably, recent research has shown a potential association between COVID-19 and change in the molecular cargo of extracellular vesicles (EVs). EVs are vesicles released by cells and play an important role in cell communication by transfer of bioactive molecules between cells. Emerging evidence shows a strong link between EVs and their molecular cargo, and regulation of metabolism in health and disease. This review focuses on current knowledge about EVs and their potential role in COVID-19 pathogenesis, their current and future implications as tools for biomarker and therapeutic development and their possible effects on long-term impact of COVID-19.

Extracellular vesicle-mediated targeting strategies for long-term health benefits in gestational diabetes.

Extracellular vesicles (EVs) are critical mediators of cell communication, playing important roles in regulating molecular cross-talk between different metabolic tissues and influencing insulin sensitivity in both healthy and gestational diabetes mellitus (GDM) pregnancies. The ability of EVs to transfer molecular cargo between cells imbues them with potential as therapeutic agents. During pregnancy, the placenta assumes a vital role in metabolic regulation, with multiple mechanisms of placenta-mediated EV cross-talk serving as central components in GDM pathophysiology. This review focuses on the role of the placenta in the pathophysiology of GDM and explores the possibilities and prospects of targeting the placenta to address insulin resistance and placental dysfunction in GDM. Additionally, we propose the use of EVs as a novel method for targeted therapeutics in treating the dysfunctional placenta. The primary aim of this review is to comprehend the current status of EV targeting approaches and assess the potential application of these strategies in placental therapeutics, thereby delivering molecular cargo and improving maternal and fetal outcomes in GDM. We propose that EVs have the potential to revolutionize GDM management, offering hope for enhanced maternal-fetal health outcomes and more effective treatments.

A novel technique using chronic infusion of small extracellular vesicles from gestational diabetes mellitus causes glucose intolerance in pregnant mice.

Small extracellular vesicles (sEVs) play a central role in cell-to-cell communication in normal physiology and in disease, including gestational diabetes mellitus (GDM). The goal of the present study was to test the hypothesis that chronic administration of sEVs isolated from GDM causes glucose intolerance in healthy pregnant mice. Small EVs were isolated from plasma between 24 and 28 weeks gestation from healthy pregnant women (controls) and GDM, and infused intravenously for 4 days in late pregnant mice using a mini-osmotic pump. Subsequently in vivo glucose tolerance was assessed, and muscle and adipose tissue insulin sensitivity and islet glucose stimulated insulin secretion (GSIS) were determined in vitro. Mice infused with sEVs from GDM developed glucose intolerance. Administration of sEVs from controls, but not sEVs from GDM women, stimulated islet GSIS and increased fasting insulin levels in pregnant mice. Neither infusion of sEVs from controls nor from GDM women affected muscle insulin sensitivity, placental insulin or mTOR signaling, placental and fetal weight. Moreover, these results were not associated with immunomodulatory effects as human sEVs did not activate mouse T cells in vitro. We suggest that circulating sEVs regulate maternal glucose homeostasis in pregnancy and may contribute to the attenuated islet insulin secretion and more pronounced glucose intolerance in GDM as compared with healthy pregnancy.

The link between gestational diabetes and cardiovascular diseases: potential role of extracellular vesicles.

Extracellular vesicles are critical mediators of cell communication. They encapsulate a variety of molecular cargo such as proteins, lipids, and nucleic acids including miRNAs, lncRNAs, circular RNAs, and mRNAs, and through transfer of these molecular signals can alter the metabolic phenotype in recipient cells. Emerging studies show the important role of extracellular vesicle signaling in the development and progression of cardiovascular diseases and associated risk factors such as type 2 diabetes and obesity. Gestational diabetes mellitus (GDM) is hyperglycemia that develops during pregnancy and increases the future risk of developing obesity, impaired glucose metabolism, and cardiovascular disease in both the mother and infant. Available evidence shows that changes in maternal metabolism and exposure to the hyperglycemic intrauterine environment can reprogram the fetal genome, leaving metabolic imprints that define life-long health and disease susceptibility. Understanding the factors that contribute to the increased susceptibility to metabolic disorders of children born to GDM mothers is critical for implementation of preventive strategies in GDM. In this review, we discuss the current literature on the fetal programming of cardiovascular diseases in GDM and the impact of extracellular vesicle (EV) signaling in epigenetic programming in cardiovascular disease, to determine the potential link between EV signaling in GDM and the development of cardiovascular disease in infants.

Extracellular vesicle-associated miRNAs are an adaptive response to gestational diabetes mellitus.

BACKGROUND: Gestational diabetes mellitus (GDM) is a serious public health issue affecting 9-15% of all pregnancies worldwide. Recently, it has been suggested that extracellular vesicles (EVs) play a role throughout gestation, including mediating a placental response to hyperglycaemia. Here, we investigated the EV-associated miRNA profile across gestation in GDM, assessed their utility in developing accurate, multivariate classification models, and determined the signaling pathways in skeletal muscle proteome associated with the changes in the EV miRNA profile. METHODS: Discovery: A retrospective, case-control study design was used to identify EV-associated miRNAs that vary across pregnancy and clinical status (i.e. GDM or Normal Glucose Tolerance, NGT). EVs were isolated from maternal plasma obtained at early, mid and late gestation (n = 29) and small RNA sequencing was performed. Validation: A longitudinal study design was used to quantify expression of selected miRNAs. EV miRNAs were quantified by real-time PCR (cases = 8, control = 14, samples at three times during pregnancy) and their individual and combined classification efficiencies were evaluated. Quantitative, data-independent acquisition mass spectrometry was use to establish the protein profile in skeletal muscle biopsies from normal and GDM. RESULTS: A total of 2822 miRNAs were analyzed using a small RNA library, and a total of 563 miRNAs that significantly changed (p < 0.05) across gestation and 101 miRNAs were significantly changed between NGT and GDM. Analysis of the miRNA changes in NGT and GDM separately identified a total of 256 (NGT-group), and 302 (GDM-group) miRNAs that change across gestation. A multivariate classification model was developed, based on the quantitative expression of EV-associated miRNAs, and the accuracy to correctly assign samples was > 90%. We identified a set of proteins in skeletal muscle biopsies from women with GDM associated with JAK-STAT signaling which could be targeted by the miRNA-92a-3p within circulating EVs. Interestingly, overexpression of miRNA-92a-3p in primary skeletal muscle cells increase insulin-stimulated glucose uptake. CONCLUSIONS: During early pregnancy, differently-expressed, EV-associated miRNAs may be of clinical utility in identifying presymptomatic women who will subsequently develop GDM later in gestation. We suggest that miRNA-92a-3p within EVs might be a protected mechanism to increase skeletal muscle insulin sensitivity in GDM.

Extracellular vesicles and their potential role inducing changes in maternal insulin sensitivity during gestational diabetes mellitus.

Gestational diabetes mellitus (GDM) is one of the most common endocrine disorders during gestation and affects around 15% of all pregnancies worldwide, paralleling the global increase in obesity and type 2 diabetes. Normal pregnancies are critically dependent on the development of maternal insulin resistance balanced by an increased capacity to secrete insulin, which allows for the allocation of nutrients for adequate foetal growth and development. Several factors including placental hormones, inflammatory mediators and nutrients have been proposed to alter insulin sensitivity and insulin response and underpin the pathological outcomes of GDM. However, other factors may also be involved in the regulation of maternal metabolism and a complete understanding of GDM pathophysiology requires the identification of these factors, and the mechanisms associated with them. Recent studies highlight the potential utility of tissue-specific extracellular vesicles (EVs) in the diagnosis of disease onset and treatment monitoring for several pregnancy-related complications, including GDM. To date, there is a paucity of data defining changes in the release, content, bioactivity and diagnostic utility of circulating EVs in pregnancies complicated by GDM. Placental EVs may engage in paracellular interactions including local cell-to-cell communication between the cell constituents of the placenta and contiguous maternal tissues, and/or distal interactions involving the release of placental EVs into biological fluids and their transport to a remote site of action. Hence, the aim of this review is to discuss the biogenesis, isolation methods and role of EVs in the physiopathology of GDM, including changes in maternal insulin sensitivity during pregnancy.

Extracellular vesicles as critical mediators of maternal-fetal communication during pregnancy and their potential role in maternal metabolism.

Extracellular vesicles (EVs) have been implicated in the pathophysiology of metabolic disorders by transferring biologically active molecules such as miRNAs and proteins to recipient cells, and influencing their metabolic pathways. Pregnancy is one of the greatest metabolic challenges faced by both the mother and the growing fetus, and this is fine-tuned by several factors, including hormones, soluble molecules, and molecules encapsulated in EVs released from the placenta. A wide range of EVs originating from the placenta are present in maternal circulation, and changes in their circulating levels and bioactivity (i.e., capacity to induce changes in the target cells) have been associated with several complications of pregnancies, including gestational diabetes mellitus (GDM), preeclampsia, preterm birth, and fetal growth restriction. Complications of pregnancies are associated with maternal metabolic dysfunction with short- and long-term consequences for both mother and child. However, the potential roles of circulating EVs originating from the placenta and other tissues (e.g. adipose tissue), on changes in maternal metabolism during normal and pregnancy complications have not been fully described. The aim of this brief review, thus, is to discuss the diversity of EVs, and their potential roles in the metabolic alterations during pregnancy, with a special focus on GDM.

Circulating Placental Extracellular Vesicles and Their Potential Roles During Pregnancy.

Background: Numerous changes in maternal physiology occur during pregnancy that are critical in controlling and maintaining the maternal metabolic adaptations and fetal development. The placenta is the key source through which the fetus receives nutrients, blood, and oxygen for growth. The human placenta releases several molecules into maternal circulation that include hormones, proteins, RNA, and DNA throughout the course of pregnancy. Additionally, extracellular vesicles (EVs) originating from the placenta have been found in the maternal circulation. Methods: In this review, we discuss the role of EVs in maternal-fetal communication during pregnancy. Results: EVs originating from the placenta can be divided into 3 categories based on their size and/or origin: exosomes (50 to 150 nm), microvesicles (nm to several µm), and apoptotic bodies or syncytial nuclear aggregates (>1 µm). The cellular microenvironment-such as oxygen tension and glucose concentration-have been found to control EV release from the placenta and their bioactivity on target cells. Furthermore, maternal EVs can stimulate cytokine release from endothelial cells and are involved in several physiologic and pathologic events in pregnancy. Conclusion: Exosomes provide a way to identify the function and metabolic state of cell origin through their ability to reflect the microenvironment that they are released from. Further understanding of how EVs regulate key events in pregnancy may help elucidate how maternal-fetal communication is established in both normal and pathologic conditions.

Quantitative Proteomics by SWATH-MS Suggest an Association Between Circulating Exosomes and Maternal Metabolic Changes in Gestational Diabetes Mellitus.

Several factors including placental hormones (PH) released from the human placenta have been associated with the development of insulin resistance and gestational diabetes mellitus (GDM). However, circulating levels of PH does not correlate well with maternal insulin sensitivity across gestation, suggesting that other, previously unrecognized, mechanisms may be involved. The levels of circulating exosomes are higher in GDM compared to normal. GDM derived exosomes produce greater release of pro-inflammatory cytokines from endothelial cells compared to exosomes from normal, suggesting that their contents may differ compared to normal pregnancies. Using a quantitative, information-independent acquisition (Sequential Windowed Acquisition of All Theoretical Mass Spectra [SWATH]) approach, differentially abundant circulating exosome proteins are identified in women with normal glucose tolerance (NGT) and GDM at the time of GDM diagnosis. A total of 78 statistically significant proteins in the relative expression of exosomal proteins in GDM are compared with NGT. Bioinformatic analysis shows that the exosomal proteins in GDM target pathways are mainly associated with energy production, inflammation, and metabolism. Finally, an independent cohort of patients is used to validate some of the proteins identified by SWATH. The data obtained may be of utility in elucidating the underlying physiological mechanisms associated with insulin resistance in GDM.

Association between insulin resistance and the development of cardiovascular disease.

For many years, cardiovascular disease (CVD) has been the leading cause of death around the world. Often associated with CVD are comorbidities such as obesity, abnormal lipid profiles and insulin resistance. Insulin is a key hormone that functions as a regulator of cellular metabolism in many tissues in the human body. Insulin resistance is defined as a decrease in tissue response to insulin stimulation thus insulin resistance is characterized by defects in uptake and oxidation of glucose, a decrease in glycogen synthesis, and, to a lesser extent, the ability to suppress lipid oxidation. Literature widely suggests that free fatty acids are the predominant substrate used in the adult myocardium for ATP production, however, the cardiac metabolic network is highly flexible and can use other substrates, such as glucose, lactate or amino acids. During insulin resistance, several metabolic alterations induce the development of cardiovascular disease. For instance, insulin resistance can induce an imbalance in glucose metabolism that generates chronic hyperglycemia, which in turn triggers oxidative stress and causes an inflammatory response that leads to cell damage. Insulin resistance can also alter systemic lipid metabolism which then leads to the development of dyslipidemia and the well-known lipid triad: (1) high levels of plasma triglycerides, (2) low levels of high-density lipoprotein, and (3) the appearance of small dense low-density lipoproteins. This triad, along with endothelial dysfunction, which can also be induced by aberrant insulin signaling, contribute to atherosclerotic plaque formation. Regarding the systemic consequences associated with insulin resistance and the metabolic cardiac alterations, it can be concluded that insulin resistance in the myocardium generates damage by at least three different mechanisms: (1) signal transduction alteration, (2) impaired regulation of substrate metabolism, and (3) altered delivery of substrates to the myocardium. The aim of this review is to discuss the mechanisms associated with insulin resistance and the development of CVD. New therapies focused on decreasing insulin resistance may contribute to a decrease in both CVD and atherosclerotic plaque generation.

Human placental exosomes in gestational diabetes mellitus carry a specific set of miRNAs associated with skeletal muscle insulin sensitivity.

There is increasing evidence that miRNAs, which are enriched in nanovesicles called exosomes, are important regulators of gene expression. When compared with normal pregnancies, pregnancies with gestational diabetes mellitus (GDM) are associated with skeletal muscle insulin resistance as well as increased levels of circulating placental exosomes. Here we investigated whether placental exosomes in GDM carry a specific set of miRNAs associated with skeletal muscle insulin sensitivity. Exosomes were isolated from chorionic villous (CV) explants from both women with Normal Glucose Tolerant (NGT) and GDM pregnancies. Using miRNA sequencing, we identified a specific set of miRNAs selectively enriched with exosomes and compared with their cells of origin indicating a specific packaging of miRNAs into exosomes. Gene target and ontology analysis of miRNA differentially expressed in exosomes secreted in GDM compared with NGT are associated with pathways regulating cell migration and carbohydrate metabolism. We determined the expression of a selected set of miRNAs in placenta, plasma, and skeletal muscle biopsies from NGT and GDM. Interestingly, the expression of these miRNAs varied in a consistent pattern in the placenta, in circulating exosomes, and in skeletal muscle in GDM. Placental exosomes from GDM pregnancies decreased insulin-stimulated migration and glucose uptake in primary skeletal muscle cells obtained from patients with normal insulin sensitivity. Interestingly, placental exosomes from NGT increase migration and glucose uptake in response to insulin in skeletal muscle from diabetic subjects. These findings suggest that placental exosomes might have a role in the changes on insulin sensitivity in normal and GDM pregnancies.

Salivary exosomes as potential biomarkers in cancer.

Over the past decade, there has been emerging research in the field of extracellular vesicles, especially those originating from endosomes, referred to as 'exosomes. Exosomes are membrane-bound nanovesicles secreted by most cell types upon fusion of multivesicular bodies (MVBs) to the cell plasma membrane. These vesicles are present in almost all body fluids such as blood, urine, saliva, breast milk, cerebrospinal and peritoneal fluids. Exosomes participate in intercellular communication by transferring the biologically active molecules like proteins, nucleic acids, and lipids to neighboring cells. Exosomes are enriched in the tumour microenvironment and growing evidence demonstrates that exosomes mediate cancer progression and metastasis. Given the important biological role played by these nanovesicles in cancer pathogenesis, these can be used as ideal non-invasive biomarkers in detecting and monitoring tumours as well as therapeutic targets. The scope of the current review is to provide an overview of exosomes with a special focus on salivary exosomes as potential biomarkers in head and neck cancers.

Extracellular vesicles and their immunomodulatory functions in pregnancy.

Extracellular vesicles (EVs) are membrane-bound vesicles released into the extracellular space by almost all types of cells. EVs can cross the physiological barriers, and a variety of biological fluids are enriched in them. EVs are a heterogeneous population of vesicles, including exosomes, microvesicles, and apoptotic bodies. The different subpopulations of vesicles can be differentiated by size and origin, in which exosomes (~100 nm and from endocytic origin) are the most studied so far. EVs have essential roles in cell-to-cell communication and are critical modulators of immune response under normal and pathological conditions. Pregnancy is a unique situation of immune-modulation in which the maternal immune system protects the fetus from allogenic rejection and maintains the immunosurveillance. The placenta is a vital organ that performs a multitude of functions to support the pregnancy. The EVs derived from the human placenta have crucial roles in regulating the maternal immune response for successful pregnancy outcome. Placenta-derived vesicles perform a myriad of functions like suppression of immune reaction to the developing fetus and establishment and maintenance of a systemic inflammatory response to combat infectious intruders. A fine-tuning of these mechanisms is quintessential for successful completion of pregnancy and healthy outcome for mother and fetus. Dysregulation in the mechanisms mentioned above can lead to several pregnancy disorders. In this review, we summarize the current literature regarding the critical roles played by the EVs in immunomodulation during pregnancy with particular attention to the placenta-derived exosomes.

Placental exosomes profile in maternal and fetal circulation in intrauterine growth restriction - Liquid biopsies to monitoring fetal growth.

INTRODUCTION: Placenta-derived exosomes may represent an additional pathway by which the placenta communicates with the maternal system to induce maternal vascular adaptations to pregnancy and it may be affected during Fetal growth restriction (FGR). The objective of this study was to quantify the concentration of total and placenta-derived exosomes in maternal and fetal circulation in small fetuses classified as FGR or small for gestational age (SGA). METHODS: Prospective cohort study in singleton term gestations including 10 normally grown fetuses and 20 small fetuses, sub-classified into SGA and FGR accordingly to birth weight (BW) percentile and fetoplacental Doppler. Exosomes were isolated from maternal and fetal plasma and characterized by morphology, enrichment of exosomal proteins, and size distribution by electron microscopy, western blot, and nanoparticle tracking analysis, respectively. Total and specific placenta-derived exosomes were determined using quantum dots coupled with CD63+ve and placental-type alkaline phosphatase (PLAP)+ve antibodies, respectively. RESULTS: Maternal concentrations of CD63+ve and PLAP+ve exosomes were similar between the groups (all p > 0.05). However, there was a significant positive correlation between the ratio of placental-derived to total exosomes (PLAP+ve ratio) and BW percentile, [rho = 0.77 (95% CI: 0.57 to 0.89); p = 0.0001]. The contribution of placental exosomes to the total exosome concentration in maternal and fetal circulation showed a significant decrease among cases, with lower PLAP+ve ratios in FGR compared to controls and SGA cases. DISCUSSION: Quantification of placental exosomes in maternal plasma reflects fetal growth and it may be a useful indicator of placental function.

Cross Talk between Adipose Tissue and Placenta in Obese and Gestational Diabetes Mellitus Pregnancies via Exosomes.

Obesity is an important public health issue worldwide, where it is commonly associated with the development of metabolic disorders, especially insulin resistance (IR). Maternal obesity is associated with an increased risk of pregnancy complications, especially gestational diabetes mellitus (GDM). Metabolism is a vital process for energy production and the maintenance of essential cellular functions. Excess energy storage is predominantly regulated by the adipose tissue. Primarily made up of adipocytes, adipose tissue acts as the body's major energy reservoir. The role of adipose tissue, however, is not restricted to a "bag of fat." The adipose tissue is an endocrine organ, secreting various adipokines, enzymes, growth factors, and hormones that take part in glucose and lipid metabolism. In obesity, the greater portion of the adipose tissue comprises fat, and there is increased pro-inflammatory cytokine secretion, macrophage infiltration, and reduced insulin sensitivity. Obesity contributes to systemic IR and its associated metabolic complications. Similar to adipose tissue, the placenta is also an endocrine organ. During pregnancy, the placenta secretes various molecules to maintain pregnancy physiology. In addition, the placenta plays an important role in metabolism and exchange of nutrients between mother and fetus. Inflammation at the placenta may contribute to the severity of maternal IR and her likelihood of developing GDM and may also mediate the adverse consequences of obesity and GDM on the fetus. Interestingly, studies on maternal insulin sensitivity and secretion of placental hormones have not shown a positive correlation between these phenomena. Recently, a great interest in the field of extracellular vesicles (EVs) has been observed in the literature. EVs are produced by a wide range of cells and are present in all biological fluids. EVs are involved in cell-to-cell communication. Recent evidence points to an association between adipose tissue-derived EVs and metabolic syndrome in obesity. In this review, we will discuss the changes in human placenta and adipose tissue in GDM and obesity and summarize the findings regarding the role of adipose tissue and placenta-derived EVs, with an emphasis on exosomes in obesity, and the contribution of obesity to the development of GDM.