Microvesicles provide a mechanism for intercellular communication by embryonic stem cells during embryo implantation

Cellular and Molecular Nature of Fragmentation of Human Embryos

Embryo fragmentation represents a phenomenon generally characterized by the presence of membrane-bound extracellular cytoplasm into the perivitelline space. Recent evidence supports the cellular and molecular heterogeneity of embryo fragments. In this narrative review, we described the different embryo fragment-like cellular structures in their morphology, molecular content, and supposed function and have reported the proposed theories on their origin over the years. We identified articles related to characterization of embryo fragmentation with a specific literature search string. The occurrence of embryo fragmentation has been related to various mechanisms, of which the most studied are apoptotic cell death, membrane compartmentalization of altered DNA, cytoskeletal disorders, and vesicle formation. These phenomena are thought to result in the extrusion of entire blastomeres, release of apoptotic bodies and other vesicles, and micronuclei formation. Different patterns of fragmentation may have different etiologies and effects on embryo competence. Removal of fragments from the embryo before embryo transfer with the aim to improve implantation potential should be reconsidered on the basis of the present observations

Extracellular vesicles released by non-small cell lung cancer cells drive invasion and permeability in non-tumorigenic lung epithelial cells

Extracellular vesicles (EVs) released from non-small cell lung cancer (NSCLC) cells are known to promote cancer progression. However, it remains unclear how EVs from various NSCLC cells differ in their secretion profile and their ability to promote phenotypic changes in non-tumorigenic cells. Here, we performed a comparative analysis of EV release from non-tumorigenic cells (HBEC/BEAS-2B) and several NSCLC cell lines (A549, H460, H358, SKMES, and Calu6) and evaluated the potential impact of NSCLC EVs, including EV-encapsulated RNA (EV-RNA), in driving invasion and epithelial barrier impairment in HBEC/BEAS-2B cells. Secretion analysis revealed that cancer cells vary in their secretion level, with some cell lines having relatively low secretion rates. Differential uptake of NSCLC EVs was also observed, with uptake of A549 and SKMES EVs being the highest. Phenotypically, EVs derived from Calu6 and H358 cells significantly enhanced invasion, disrupted an epithelial barrier, and increased barrier permeability through downregulation of E-cadherin and ZO-1. EV-RNA was a key contributing factor in mediating these phenotypes. More nuanced analysis suggests a potential correlation between the aggressiveness of NSCLC subtypes and the ability of their respective EVs to induce cancerous phenotypes.

The Role of Extracellular Vesicles in Embryo Implantation

Extracellular vesicles (EVs) are membrane-coating nanoparticles derived from cells. The effect of cell-to-cell communication mediated by EVs has been investigated in different fields of physio-logical as well as pathological process in recent years. Reproduction, regarded as a definitive characteristic of organisms, has been a focus in both animal and medical sciences. It is well agreed that implantation is a critical event during early pregnancy in viviparous animals, and a proper implantation is essential for the establishment and maintenance of normal pregnancy. However, successful implantation requires the synchronized development of both the uterus and the embryo, therefore, in which well communication and opportune regulation are necessary. This review focuses on the progression of studies that reveal the role of EVs in early pregnancy, especially during implantation. Based on current evidence, EVs are produced and exist in the environment for implantation. It has been proved that EVs of different origins such as endometrium and embryo, have positive influences on embryo implantation. With their cargos of proteins and nucleic acids (especially microRNAs), EVs exert their effects including information transportation, immune stimulation and regulation of gene expression.

Circulating extracellular vesicles and rheumatoid arthritis: a proteomic analysis

Circulating extracellular vesicles (EVs) are membrane-bound nanoparticles secreted by most cells for intracellular communication and transportation of biomolecules. EVs carry proteins, lipids, nucleic acids, and receptors that are involved in human physiology and pathology. EV cargo is variable and highly related to the type and state of the cellular origin. Three subtypes of EVs have been identified: exosomes, microvesicles, and apoptotic bodies. Exosomes are the smallest and the most well-studied class of EVs that regulate different biological processes and participate in several diseases, such as cancers and autoimmune diseases. Proteomic analysis of exosomes succeeded in profiling numerous types of proteins involved in disease development and prognosis. In rheumatoid arthritis (RA), exosomes revealed a potential function in joint inflammation. These EVs possess a unique function, as they can transfer specific autoantigens and mediators between distant cells. Current proteomic data demonstrated that exosomes could provide beneficial effects against autoimmunity and exert an immunosuppressive action, particularly in RA. Based on these observations, effective therapeutic strategies have been developed for arthritis and other inflammatory disorders.

Recent Insights into Human Endometrial Peptidases in Blastocyst Implantation via Shedding of Microvesicles

Blastocyst implantation involves multiple interactions with numerous molecules expressed in endometrial epithelial cells (EECs) during the implantation window; however, there is limited information regarding the molecular mechanism underlying the crosstalk. In blastocysts, fibronectin plays a major role in the adhesion of various types of cells by binding to extracellular matrix proteins via the Arg-Gly-Asp (RGD) motif. In EECs, RGD-recognizing integrins are important bridging receptors for fibronectin, whereas the non-RGD binding of fibronectin includes interactions with dipeptidyl peptidase IV (DPPIV)/cluster of differentiation (CD) 26. Fibronectin may also bind to aminopeptidase N (APN)/CD13, and in the endometrium, these peptidases are present in plasma membranes and lysosomal membranes. Blastocyst implantation is accompanied by lysosome exocytosis, which transports various peptidases and nutrients into the endometrial cavity to facilitate blastocyst implantation. Both DPPIV and APN are released into the uterine cavity via shedding of microvesicles (MVs) from EECs. Recently, extracellular vesicles derived from endometrial cells have been proposed to act on trophectoderm cells to promote implantation. MVs are also secreted from embryonal stem cells and may play an active role in implantation. Thus, crosstalk between the blastocyst and endometrium via extracellular vesicles is a new insight into the fundamental molecular basis of blastocyst implantation.

Placental trophoblast cell-derived exosomal microRNA-1290 promotes the interaction between endometrium and embryo by targeting LHX6

Communication between the maternal uterus and the embryo is vital for a successful pregnancy. Exosomes, subtypes of extracellular vesicles comprising many bioactive factors, regulate the early stages of pregnancy, specifically during embryo implantation. Nevertheless, the mechanism by which exosomal microRNAs (miRNAs) derived from placental trophoblasts regulate embryo implantation remains elusive. We isolated and identified exosomes derived from placental trophoblast cells (HTR8/SVneo). Subsequently, we evaluated the loading miRNA in exosomes by small RNA sequencing. Consequently, we showed that trophoblast cell-derived exosomes could transfer to endometrial epithelial cells. Besides, these exosomes promoted the epithelial-mesenchymal transition (EMT) as well as migration of endometrial cells and were implicated in the regulation of inflammation. Further, the specific miRNAs were screened in exosomes, and as a result, miRNA (miR)-1290 was enriched specifically in exosomes. miR-1290 promoted the expression of inflammatory factors (interleukin [IL]-6 and IL-8) and migration of endometrial epithelial cells. In addition, exosomal miR-1290 promoted angiogenesis in vitro. More importantly, by targeting LHX6, trophoblast HTR8/SVneo cell-derived exosomal miR-1290 promoted the EMT process of endometrial epithelial cell HEC-1-A. Altogether, our findings provide novel insights into the mechanism of trophoblast cell-derived exosomes during embryo implantation.

Neutrophil microvesicles and their role in disease

Microvesicles are formed through shedding from the plasma membrane, a process shared by almost all human cells. Microvesicles are highly abundant and have been detected in blood, urine, cerebrospinal fluid, and saliva. They contain a library of cargo derived from their parental cell during formation, including proteases, micro-RNAs and lipids and delivery of this parental cell-derived cargo to other cells can alter target cell function and drive disease. Cell specific molecules on the surface of microvesicles, obtained during microvesicle formation, allows their parental cell to be identified and populations of microvesicles to be investigated for roles in the pathogenesis of various diseases. For instance, recent work by our group has identified a role for neutrophil microvesicles in atherosclerosis. Microvesicle profiles could in future be associated with certain diseases and act as a biomarker to allow for earlier diagnosis. This short review will discuss some of the processes central to all microvesicles before focusing on neutrophil microvesicles, their potential role in cardiovascular disease and the mechanisms that may underpin this.

M2 macrophage microvesicle-inspired nanovehicles improve accessibility to cancer cells and cancer stem cells in tumors

Cancer cells and cancer stem cells (CSCs) are the major players of cancer malignancy and metastasis, but they are extremely difficult to access. Inspired by the vital role of macrophages and microvesicle-mediated cell–cell communication in tumors, we herein designed M2 macrophage microvesicle-inspired nanovehicle of cabazitaxel (M-CFN) to promote accessibility to cancer cells and CSCs in tumors. In the 4T1 tumor model, M-CFN flexibly permeated the tumor mass, accessed cancer cells and CD90-positive cells, and significantly promoted their entry into CSC fractions in tumors. Moreover, M-CFN treatment profoundly eliminated aldehyde dehydrogenase (ALDH)-expressing CSCs in 4T1 and MCF-7 tumors, produced notable depression of tumor growth and caused 93.86% suppression of lung metastasis in 4T1 models. Therefore, the M2 macrophage microvesicle-inspired nanovehicle provides an encouraging strategy to penetrate the tumor tissues and access these insult cells in tumors for effective cancer therapy.

The Roles of Extracellular Vesicles in Malignant Melanoma

Different types of cells, such as endothelial cells, tumor-associated fibroblasts, pericytes, and immune cells, release extracellular vesicles (EVs) in the tumor microenvironment. The components of EVs include proteins, DNA, RNA, and microRNA. One of the most important functions of EVs is the transfer of aforementioned bioactive molecules, which in cancer cells may affect tumor growth, progression, angiogenesis, and metastatic spread. Furthermore, EVs affect the presentation of antigens to immune cells via the transfer of nucleic acids, peptides, and proteins to recipient cells. Recent studies have also explored the potential application of EVs in cancer treatment. This review summarizes the mechanisms by which EVs regulate melanoma development, progression, and their potentials to be applied in therapy. We initially describe vesicle components; discuss their effects on proliferation, anti-melanoma immunity, and drug resistance; and finally focus on the effects of EV-derived microRNAs on melanoma pathobiology. This work aims to facilitate our understanding of the influence of EVs on melanoma biology and initiate ideas for the development of novel therapeutic strategies.

Biologia futura: embryo-maternal communication via progesterone-induced blocking factor (PIBF) positive embryo-derived extracellular vesicles. Their role in maternal immunomodulation

Paternal antigens expressed by the foetus are recognized as foreign. Therefore,-according to the rules of transplantation immunity-the foetus ought to be "rejected". However, during normal gestation, maternal immune functions are re-adjusted, in order to create a favourable environment for the developing foetus. Some of the mechanisms that contribute to the altered immunological environment, for example, the cytokine balance and NK cell function, with special emphasis on the role of progesterone and the progesterone-induced blocking factor (PIBF) will be reviewed.

Overview of the Therapeutic Applications of Stem Cell-Derived Exosomes: A Research and Commercial Perspective

Progress in extracellular vesicle (EV) research over the past two decades has generated significant interest in using EVs in the biomedical field. Exosomes are a subgroup of EVs that comprise endocytic membrane-bound nanovesicles of 40 to 160 nm diameter. These vesicles have been shown to facilitate intercellular communication via the delivery of cellular molecules. There are currently several exciting applications for exosomes being developed in therapeutics, diagnostics, drug delivery, and cellular reprogramming. Stem cell-derived exosomes present the opportunity to harness the power of stem cells while circumventing several of the risks associated with their use. This review summarizes the recent developments in exosome technology and lends a prospective view to the future of exosome use and application in research and medicine. Through a review of relevant patent filings, recent literature, and ongoing clinical trials, a valuable overview of the field of exosomes is provided. © 2021 Wiley Periodicals LLC.

The Role of Non-Immune Cell-Derived Extracellular Vesicles in Allergy

Extracellular vesicles (EVs), and especially exosomes, have been shown to mediate information exchange between distant cells; this process directly affects the biological characteristics and functionality of the recipient cell. As such, EVs significantly contribute to the shaping of immune responses in both physiology and disease states. While vesicles secreted by immune cells are often implicated in the allergic process, growing evidence indicates that EVs from non-immune cells, produced in the stroma or epithelia of the organs directly affected by inflammation may also play a significant role. In this review, we provide an overview of the mechanisms of allergy to which those EVs contribute, with a particular focus on small EVs (sEVs). Finally, we also give a clinical perspective regarding the utilization of the EV-mediated communication route for the benefit of allergic patients.

The mini player with diverse functions: extracellular vesicles in cell biology, disease, and therapeutics

Extracellular vesicles (EVs) are tiny biological nanovesicles ranging from approximately 30-1000 nm in diameter that are released into the extracellular matrix of most cell types and in biofluids. The classification of EVs includes exosomes, microvesicles, and apoptotic bodies, dependent on various factors such as size, markers, and biogenesis pathways. The transition of EV relevance from that of being assumed as a trash bag to be a key player in critical physiological and pathological conditions has been revolutionary in many ways. EVs have been recently revealed to play a crucial role in stem cell biology and cancer progression via intercellular communication, contributing to organ development and the progression of cancer. This review focuses on the significant research progress made so far in the role of the crosstalk between EVs and stem cells and their niche, and cellular communication among different germ layers in developmental biology. In addition, it discusses the role of EVs in cancer progression and their application as therapeutic agents or drug delivery vehicles. All such discoveries have been facilitated by tremendous technological advancements in EV-associated research, especially the microfluidics systems. Their pros and cons in the context of characterization of EVs are also extensively discussed in this review. This review also deliberates the role of EVs in normal cell processes and disease conditions, and their application as a diagnostic and therapeutic tool. Finally, we propose future perspectives for EV-related research in stem cell and cancer biology.

Cow's milk may be delivering potentially harmful undetected cargoes to humans. Is it time to reconsider dairy recommendations?

Mammalian evolution has shaped milk into a species-specific vehicle for post-natal development, continuing what began within the mother's womb. Increased consumption of the mother's breast milk is associated with the most adequate metabolic programming and lowers the incidence of the diseases of civilization during adulthood. An abundance of short sequences of RNA, known as microRNA, exists in mammalian breast milk, enclosed within robust small extracellular vesicles known as exosomes. These microRNAs can epigenetically regulate over 60% of human genes. When cow's milk is consumed by humans, the bovine exosomes are transported through the gastrointestinal tract, detected intact in the blood stream, and taken up by target cells, where they alter protein expression. The aim of this review was to highlight the role of dairy exosomes and microRNA, and of the type of dairy product consumed, in human diseases. Given that microRNAs are involved in a vast array of physiological processes and associated with several diseases, perhaps caution should be practiced with regard to human consumption of dairy, particularly for individuals within developmentally critical time frames, such as pregnant and lactating mothers, and young children.

The effects of aging on molecular modulators of human embryo implantation

Advancing age has a negative impact on female fertility. As implantation rates decline during the normal maternal life course, age-related, embryonic factors are altered and our inability to monitor these factors in an unbiased genome-wide manner in vivo has severely limited our understanding of early human embryo development and implantation. Our high-throughput methodology uses trophectoderm samples representing the full spectrum of maternal reproductive ages with embryo implantation potential examined in relation to trophectoderm transcriptome dynamics and reproductive maternal age. Potential embryo-endometrial interactions were tested using trophectoderm sampled from young women, with the receptive uterine environment representing the most 'fertile' environment for successful embryo implantation. Potential roles for extracellular exosomes, embryonic metabolism and regulation of apoptosis were revealed. These biomarkers are consistent with embryo-endometrial crosstalk/developmental competency, serving as a mediator for successful implantation. Our data opens the door to developing a diagnostic test for predicting implantation success in women undergoing fertility treatment.

Extracellular vesicles activate ATM-Chk2 signaling pathway through the intercellular transfer of mitochondrial DNA in HBV-infected human hepatocytes

Hepatitis B virus (HBV) is a human hepatotropic pathogen causing hepatocellular carcinoma. We recently obtained HBV-susceptible immortalized human hepatocyte NKNT-3 by exogenously expressing NTCP and its derived cell clones, #28.3.8 and #28.3.25.13 exhibiting different levels of HBV susceptibility. In the present study, we showed that HBV infection activated the ATM-Chk2 signaling pathway in #28.3.25.13 cells but not in #28.3.8 cells. Both the cell culture supernatant and extracellular vesicles (EVs) derived from HBV-infected #28.3.25.13 cells also activated the ATM-Chk2 signaling pathway in naïve #28.3.25.13 cells. Interestingly, EVs derived from HBV-infected #28.3.25.13 cells included higher level of mitochondrial DNA (mtDNA) than those from HBV-infected #28.3.8 cells. Based on our results, we propose the novel model that EVs mediate the activation of ATM-Chk2 signaling pathway by the intercellular transfer of mtDNA in HBV-infected human hepatocyte.

Impact of exosome-mediated feto-maternal interactions on pregnancy maintenance and development of obstetric complications

Pregnancy is an immunological paradox, a phenomenon in which the foetus and the placenta, containing foreign antigens to the mother, develop without inducing rejection by the maternal immune system. Cell-to-cell communication between the foetus and the mother is mediated by secreted factors such as cytokines, hormones and extracellular vesicles (EVs) for a successful pregnancy and to avoid rejection. Exosomes, the smallest of EVs, are released extracellularly, where they are taken up by proximal or distant recipient cells. Here, we discuss the role of EVs, especially exosomes in feto-maternal communication during pregnancy. This review will provide an overview of the functional roles exosomes may play during embryo implantation, modulating immune responses during pregnancy and the onset of labour. Moreover, we will discuss exosomal function in obstetric pathology, and the development of pregnancy-associated complications such as preeclampsia and preterm birth as well as the biomarker potential of exosomes for detecting such conditions.

Extracellular vesicles as a potential diagnostic tool in assisted reproduction

PURPOSE OF REVIEW

Extracellular vesicles have emerged as a promising field of research for their potential to serve as biomarkers. In the pathophysiology of reproduction, they have attracted significant attention because of their diverse roles in gametogenesis and embryo-endometrial cross-talk. Advances in extracellular vesicle translational potential are herein reviewed with a particular focus in oocyte competence, semen quality diagnostics, embryo selection and detection of endometrial receptivity.

RECENT FINDINGS

Specific miRNAs present in follicular fluid-derived extracellular vesicles have been associated with follicle development and oocyte maturation. Some proteins known to regulate sperm function and capacitation such as glycodelin, and CRISP1 have been found as overrepresented in semen exosomes isolated from severe asthenozoospermic compared to normozoospermic men. In vitro developed human embryos can secrete extracellular vesicles whose propitiousness for preimplantation genetic testing is being increasingly investigated. Endometrial cell-derived extracellular vesicles recovered from uterine flushings might represent a reservoir of molecular markers potentially exploited for monitoring the endometrial status.

SUMMARY

Accumulated knowledge on extracellular vesicles deriving from endometrium, follicular fluid, embryos or male reproductive system may be translated to clinical practice to inform diagnostics in assisted reproduction technology (ART). Validation studies and technology developments are required to implement the profiling of extracellular vesicles as diagnostic tests in ART.

Mesenchymal stem cell-derived microvesicles improve intestinal barrier function by restoring mitochondrial dynamic balance in sepsis rats

BACKGROUND

Sepsis is a major cause of death in ICU, and intestinal barrier dysfunction is its important complication, while the treatment is limited. Recently, mesenchymal stem cell-derived microvesicles (MMVs) attract much attention as a strategy of cell-free treatment; whether MMVs are therapeutic in sepsis induced-intestinal barrier dysfunction is obscure.

METHODS

In this study, cecal ligation and puncture-induced sepsis rats and lipopolysaccharide-stimulated intestinal epithelial cells to investigate the effect of MMVs on intestinal barrier dysfunction. MMVs were harvested from mesenchymal stem cells and were injected into sepsis rats, and the intestinal barrier function was measured. Afterward, MMVs were incubated with intestinal epithelial cells, and the effect of MMVs on mitochondrial dynamic balance was measured. Then the expression of mfn1, mfn2, OPA1, and PGC-1α in MMVs were measured by western blot. By upregulation and downregulation of mfn2 and PGC-1α, the role of MMVs in mitochondrial dynamic balance was investigated. Finally, the role of MMV-carried mitochondria in mitochondrial dynamic balance was investigated.

RESULTS

MMVs restored the intestinal barrier function by improving mitochondrial dynamic balance and metabolism of mitochondria. Further study revealed that MMVs delivered mfn2 and PGC-1α to intestinal epithelial cells, and promoted mitochondrial fusion and biogenesis, thereby improving mitochondrial dynamic balance. Furthermore, MMVs delivered functional mitochondria to intestinal epithelial cells and enhanced energy metabolism directly.

CONCLUSION

MMVs can deliver mfn2, PGC-1α, and functional mitochondria to intestinal epithelial cells, synergistically improve mitochondrial dynamic balance of target cells after sepsis, and restore the mitochondrial function and intestinal barrier function. The study illustrated that MMVs might be a promising strategy for the treatment of sepsis.

Microvesicles and exosomes released by amnion epithelial cells under oxidative stress cause inflammatory changes in uterine cells†

Extracellular vesicles play a crucial role in feto-maternal communication and provide an important paracrine signaling mechanism in pregnancy. We hypothesized that fetal cells-derived exosomes and microvesicles (MVs) under oxidative stress (OS) carry unique cargo and traffic through feto-maternal interface, which cause inflammation in uterine cells associated with parturition. Exosomes and MVs, from primary amnion epithelial cell (AEC) culture media under normal or OS-induced conditions, were isolated by optimized differential centrifugation method followed by characterization for size (nanoparticle tracking analyzer), shape (transmission electron microscopy), and protein markers (western blot and immunofluorescence). Cargo and canonical pathways were identified by mass spectroscopy and ingenuity pathway analysis. Myometrial, decidual, and cervical cells were treated with 1 × 107 control/OS-derived exosomes/MVs. Pro-inflammatory cytokines were measured using a Luminex assay. Statistical significance was determined by paired T-test (P < 0.05). AEC produced cup-shaped exosomes of 90-150 nm and circular MVs of 160-400 nm. CD9, heat shock protein 70, and Nanog were detected in exosomes, whereas OCT-4, human leukocyte antigen G, and calnexin were found in MVs. MVs, but not exosomes, were stained for phosphatidylserine. The protein profiles for control versus OS-derived exosomes and MVs were significantly different. Several inflammatory pathways related to OS were upregulated that were distinct between exosomes and MVs. Both OS-derived exosomes and MVs significantly increased pro-inflammatory cytokines (granulocyte-macrophage colony-stimulating factor, interleukin 6 (IL-6), and IL-8) in maternal cells compared with control (P < 0.05). Our findings suggest that fetal-derived exosomes and MVs under OS exhibited distinct characteristics and a synergistic inflammatory role in uterine cells associated with the initiation of parturition.

Expression of obesity-related genes in human spermatozoa affects the outcomes of reproductive treatments

OBJECTIVE

To study the abundance of obesity-related gene (ORG) mRNA in human spermatozoa and its association with sperm quality parameters, embryonic development, and pregnancy rates after assisted reproduction treatment (ART).

DESIGN

Cross-sectional study of spermatozoa ORG mRNA expression, and sperm and embryonic development parameters of infertile couples attending a single ART center.

SETTING

University, in collaboration with a medically assisted reproduction center.

PATIENT(S)

One hundred six couples seeking fertility treatment and receiving ART.

INTERVENTION(S)

Expression of spermatozoa ORG mRNA was assessed by quantitative reverse transcription-polymerase chain reaction. Sperm and embryonic development parameters were measured by board-certified embryologists. Serum β-human chorionic gonadotropin levels and fetal heartbeat detection on ultrasound were used to document biochemical and clinical pregnancy, respectively.

MAIN OUTCOME MEASURE(S)

Correlations between the abundance of ORG transcripts in spermatozoa and sperm quality, embryonic development, and achievement of pregnancy.

RESULTS

The abundance of spermatozoa FTO mRNA was positively correlated with total sperm count (r = 0.5030), fertilization rate (r = 0.4854), embryo cleavage rate (r = 0.5705), and high-quality embryo rate (r = 0.6982). The abundance of spermatozoa MC4R transcript was negatively correlated with sperm viability (r = -0.3111) and positively correlated with biochemical pregnancy (r = 0.4420). The abundance of MC4R and GNPDA2 transcripts was higher in spermatozoa of men with asthenozoospermia and teratozoospermia than in those with normozoospermia.

CONCLUSION

To our knowledge, this is the first report showing that the abundance of MC4R and FTO transcripts in spermatozoa is associated with sperm and embryo quality parameters, as well as pregnancy rates. Overall, these results further support the view that male factors beyond classic sperm quality parameters, namely the abundance of ORG transcripts, also affect the outcome of ART.

Extracellular Vesicles: Novel Opportunities to Understand and Detect Neoplastic Diseases

With a size range from 30 to 1000 nm, extracellular vesicles (EVs) are one of the smallest cell components able to transport biologically active molecules. They mediate intercellular communications and play a fundamental role in the maintenance of tissue homeostasis and pathogenesis in several types of diseases. In particular, EVs actively contribute to cancer initiation and progression, and there is emerging understanding of their role in creation of the metastatic niche. This fact underlies the recent exponential growth in EV research, which has improved our understanding of their specific roles in disease and their potential applications in diagnosis and therapy. EVs and their biomolecular cargo reflect the state of the diseased donor cells, and can be detected in body fluids and exploited as biomarkers in cancer and other diseases. Relatively few studies have been published on EVs in the veterinary field. This review provides an overview of the features and biology of EVs as well as recent developments in EV research including techniques for isolation and analysis, and will address the way in which the EVs released by diseased tissues can be studied and exploited in the field of veterinary pathology. Uniquely, this review emphasizes the important contribution that pathologists can make to the field of EV research: pathologists can help EV scientists in studying and confirming the role of EVs and their molecular cargo in diseased tissues and as biomarkers in liquid biopsies.

Extracellular vesicles: Critical players during cell migration

Cell migration is essential for the development and maintenance of multicellular organisms, contributing to embryogenesis, wound healing, immune response, and other critical processes. It is also involved in the pathogenesis of many diseases, including immune deficiency disorders and cancer metastasis. Recently, extracellular vesicles (EVs) have been shown to play important roles in cell migration. Here, we review recent studies describing the functions of EVs in multiple aspects of cell motility, including directional sensing, cell adhesion, extracellular matrix (ECM) degradation, and leader-follower behavior. We also discuss the role of EVs in migration during development and disease and the utility of imaging tools for studying the role of EVs in cell migration.

Endometrial extracellular vesicles of recurrent implantation failure patients inhibit the proliferation, migration, and invasion of HTR8/SVneo cells

PURPOSE

Endometrial extracellular vesicles are essential in regulating trophoblasts' function. This study aims to investigate whether endometrial extracellular vesicles (EVs) from recurrent implantation failure (RIF) patients inhibit the proliferation, invasion, and migration of HTR8/SVneo cells.

METHODS

Eighteen RIF patients and thirteen fertile women were recruited for endometria collection. Endometrial cells isolated from the endometria were cultured and modulated by hormones, and the conditioned medium was used for EV isolation. EVs secreted by the endometrial cells of RIF patients (RIF-EVs) or fertile women (FER-EVs) were determined by Western blotting, nanoparticle tracking analysis, and transmission electron microscopy. Fluorescence-labeled EVs were used to visualize internalization by HTR8/SVneo cells. RIF-EVs and FER-EVs were co-cultured with HTR8/SVneo cells. Cell Counting Kit-8, transwell invasion, and wound closure assays were performed to determine cellular proliferation, invasion, and migration, respectively, in different treatments.

RESULTS

RIF-EVs and FER-EVs were bilayer membrane vesicles, ranging from 100 to 150 nm in size, that expressed the classic EV markers Alix and CD9. RIF-EVs and FER-EVs were internalized by HTR8/SVneo cells within 2 h. The proliferation rate in the FER-EV group was significantly higher than that in the RIF-EV group at 20 μg/mL. Moreover, the invasion and migration capacity of trophoblast cells were decreased in the RIF-EV group relative to the FER-EV group at 20 μg/mL.

CONCLUSION

Endometrial EVs from RIF patients inhibited the functions of trophoblasts by decreasing their proliferation, migration, and invasive capacity. Such dysregulations induced by RIF-EVs may provide novel insights for better understanding the pathogenesis of implantation failure.

Extracellular vesicles in embryo implantation and disorders of the endometrium

Implantation of the embryo is a rate-limiting step for a successful pregnancy, and it requires an intricate crosstalk between the embryo and the endometrium. Extracellular vesicles (EVs) are membrane-enclosed, nano-sized structures produced by cells to mediate cell to cell communication and modulate a diverse set of biological processes. Herein, we review the involvement of EVs in the process of embryo implantation and endometrial diseases. EVs have been isolated from uterine fluid, cultured endometrial epithelial/stromal cells and trophectodermal cells. The endometrial epithelial and stromal/decidual cell-derived EVs and its cargo are internalized bythe trophoblast cells, and they regulate a diverse set of genes involved in adhesion, invasion and migration. Conversely, the embryo-derived EVs and its cargo are internalized by epithelial and immune cells of the endometrium for biosensing and immunomodulation required for successful implantation. EVs have also been shown to play a role in infertility, recurrent implantation failure, endometriosis, endometritis and endometrial cancer. Further research should set a stage for EVs as non-invasive "liquid biopsy" tools for assessment of endometrial health.

The Complicated Effects of Extracellular Vesicles and Their Cargos on Embryo Implantation

As a rate-limiting step in pregnancy, embryo implantation is highly dependent on intercellular communication. Extracellular vesicles (EVs) are newly identified to be important in the course of intercellular communication. EVs have been isolated from a wide variety of biofluids and tissues, including plasma, liver, uterine, semen, embryo, etc. The present and future use of EVs not only as biomarkers, but also as targeting drug delivery system, is promisingly pave the way for advanced comprehension of implantation failure in reproductive diseases. However, as the precise mechanisms of EVs in embryo implantation has not been elucidated yet. Herein, we summarize the current knowledge on the diverse effects of EVs from various sources and their cargos such as microRNA, long non-coding RNA, protein, etc. on embryo implantation, and the potential mechanisms of EVs in reproductive diseases such as recurrent implantation failure, polycystic ovary syndrome and endometriosis. It is essential to note that many of the biologically plausible functions of EVs in embryo implantation discussed in present literatures still need further research in vivo.

Using exosomal miRNAs extracted from porcine follicular fluid to investigate their role in oocyte development

BACKGROUND

Follicular development is crucial to normal oocyte maturation, with follicular size closely related to oocyte maturation. To better understand the molecular mechanisms behind porcine oocyte maturation, we obtained exosomal miRNA from porcine follicular fluid (PFF). These miRNA samples were then sequenced and analyzed regarding their different follicular sizes, as described in the methods section.

RESULTS

First, these results showed that this process successfully isolated PFF exosomes. Nearly all valid reads from the PFF exosomal sequencing data were successfully mapped to the porcine genome database. Second, we used hierarchical clustering methods to determine that significantly expressed miRNAs were clustered into A, B, C, and D groups in our heatmap according to different follicle sizes. These results allowed for the targeting of potential mRNAs genes related to porcine oocyte development. Third, we chose ten, significantly expressed miRNAs and predicted their target genes for further GO analysis. These results showed that the expression levels of neurotransmitter secretion genes were greatly changed, as were many target genes involved in the regulation of FSH secretion. Notably, these are genes that are very closely related to oocyte maturation in growing follicles. We then used pathway analysis for these targeted genes based on the originally selected ten miRNAs. Results indicated that the pathways were mainly related to the biosynthesis of TGF-beta and its signaling pathway, which are very closely related to reproductive system functions.

CONCLUSIONS

Finally, these exosomal miRNAs obtained from PFF may provide a valuable addition to our understanding of the mechanism of porcine oocyte maturation. It is also likely that these exosomal miRNAs could function as molecular biomarkers to choose high-quality oocytes and allow for in vitro porcine embryo production.

Embryonic Stem Cell-Derived Extracellular Vesicles Maintain ESC Stemness by Activating FAK

It is critical that epiblast cells within blastocyst-stage embryos receive the necessary regulatory cues to remain pluripotent until the appropriate time when they are stimulated to undergo differentiation, ultimately to give rise to an entire organism. Here, we show that exposure of embryonic stem cells (ESCs), which are the in vitro equivalents of epiblasts, to ESC-derived extracellular vesicles (EVs) helps to maintain their stem cell properties even under culture conditions that would otherwise induce differentiation. EV-treated ESCs continued to express stemness genes, preserving their pluripotency and ability to generate chimeric mice. These effects were triggered by fibronectin bound to the surfaces of EVs, enabling them to interact with ESC-associated integrins and activate FAK more effectively than fibronectin alone. Overall, these findings highlight a potential regulatory mechanism whereby epiblast cells, via their shed EVs, create an environment within the blastocyst that prevents their premature differentiation and maintains their pluripotent state.

Similar Repair Effects of Human Placenta, Bone Marrow Mesenchymal Stem Cells, and Their Exosomes for Damaged SVOG Ovarian Granulosa Cells

Background

This study is aimed at investigating the repairing effect of mesenchymal stem cells and their exosomes from different sources on ovarian granulosa cells damaged by chemotherapy drugs—phosphoramide mustard (PM).

Methods

In this study, we choose bone marrow mesenchymal stem cells (BMSCs) and human placental mesenchymal stem cells (HPMSCs) for research. Then, they were cocultured with human ovarian granulosa cells (SVOG) injured by phosphoramide mustard (PM), respectively. β-Galactosidase staining, flow cytometry, and Western blot were used to detect the changes in the senescence and apoptosis of SVOG cells before and after their coculture with the above two types of MSCs. Subsequently, exosomes from these two types of MSCs were extracted and added to the culture medium of SVOG cells after PM injury to test whether these two types of exosomes played a role similar to that of MSCs in repairing damaged SVOG cells.

Results

PM treatment-induced apoptotic SVOG cells were significantly decreased after HPMSCs and BMSCs as compared with control group. After coculturing with these two types of MSCs, PM-treated SVOG cells showed significantly reduced senescence and apoptosis proportions as well as cleaved-Caspase 3 expression, and HPMSCs played a slightly stronger role than BMSCs in repairing SVOG cells in terms of the above three indicators. In addition, the ratios of senescent and apoptotic SVOG cells were also significantly reduced by the two types of exosomes, which played a role similar to that of MSCs in repairing cell damages.

Conclusions

The results indicated that BMSCs, HPMSCs, and their exosomes all exerted a certain repair effect on SVOG cells damaged by PM, and consistent repair effect was observed between exosomes and MSCs. The repair effect of exosomes secreted from BMSCs and HPMSCs on the SVOG cells was studied for the first time, and the results fully demonstrated that exosomes are the key carriers for MSCs to play their role.

Endometrial cell-derived small extracellular vesicle miR-100-5p promotes functions of trophoblast during embryo implantation

Communication between maternal uterus and blastocyst occurs in the early stages of pregnancy, and the interaction influences the success of embryo implantation. Whereas small extracellular vesicles (sEVs) play an essential role in mediating intercellular communication in numerous biological processes, their role in embryo implantation during the window of implantation (WOI) remains poorly defined. Here, we report that endometrial epithelial cells (EECs) secrete sEVs during early pregnancy, which affects the trophoblast behaviors (migration, invasion, and proliferation), thus influencing embryo implantation. We show that microRNA (miR)-100-5p, sEVs containing microRNA (miRNA), activates both focal adhesion kinase (FAK) and c-Jun N-terminal kinase (JNK), as well as contributes to trophoblast migration and invasion. Furthermore, our findings indicate that the sEV miR-100-5p promotes angiogenesis during the implantation process. In conclusion, this study reveals a novel mechanism by which EEC-derived sEV miR-100-5p crosstalks with trophoblasts, leading to an enhanced ability for implantation.

The Biological Function of Extracellular Vesicles during Fertilization, Early Embryo-Maternal Crosstalk and Their Involvement in Reproduction: Review and Overview

Secretory extracellular vesicles (EVs) are membrane-enclosed microparticles that mediate cell to cell communication in proximity to, or distant from, the cell of origin. Cells release a heterogeneous spectrum of EVs depending on their physiologic and metabolic state. Extracellular vesicles are generally classified as either exosomes or microvesicles depending on their size and biogenesis. Extracellular vesicles mediate temporal and spatial interaction during many events in sexual reproduction and supporting embryo-maternal dialogue. Although many omic technologies provide detailed understanding of the molecular cargo of EVs, the difficulty in obtaining populations of homogeneous EVs makes difficult to interpret the molecular profile of the molecules derived from a miscellaneous EV population. Notwithstanding, molecular characterization of EVs isolated in physiological and pathological conditions may increase our understanding of reproductive and obstetric diseases and assist the search for potential non-invasive biomarkers. Moreover, a more precise vision of the cocktail of biomolecules inside the EVs mediating communication between the embryo and mother could provide new insights to optimize the therapeutic action and safety of EV use.

Extracellular Vesicle Mediated Crosstalk Between the Gametes, Conceptus, and Female Reproductive Tract

Extracellular vesicles (EVs) mediated intracellular communication plays an imperative role in the proper completion of different physiological events. Most of the bio-fluids are enriched with several subpopulations of EVs including exosomes and microvesicles (MVs), with the capacity of transferring different functional molecules (lipids, proteins, and nucleic acids) to target cells. Recipient cells upon receiving the signal molecules undergo different changes that positively affect the structural and functional integrity of the cells. This article was aimed to highlight the role of EVs secreted by gametes, the female reproductive tract, and the growing conceptus in the successful completion of different reproductive events related to gestation. EVs associated with the reproductive system are actively involved in the regulation of different physiological events including gamete maturation, fertilization, and embryo and fetal development. In the reproductive system, EVs mediated intracellular communication is not unidirectional but is rather regulated through crosstalk between the reproductive tract and the growing conceptus. These vesicles are secreted from the ovary, oviductal epithelium, endometrium, developing embryo, and the placenta. The cargo inside these vesicles exerts pleiotropic effects on both maternal and embryonic environments. A better understanding of the EVs-mediated crosstalk will be helpful in the development of useful tools serving both the diagnostic as well as therapeutic needs related to female fertility.

Extracellular vesicles: Mediators of embryo-maternal crosstalk during pregnancy and a new weapon to fight against infertility

In modern-day life, infertility is one of the major issues that can affect an individual, both physically and psychologically. Several anatomical, physiological, and genetic factors might contribute to the infertility of an individual. Intercellular communication between trophectoderm and endometrial epithelium triggers successful embryo implantation and thereby establishes pregnancy. Recent studies demonstrate that Extracellular vesicles (EVs) are emerging as one of the crucial components that are involved in embryo-maternal communication and promote pregnancy. Membrane-bound EVs release several secreted factors within the uterine fluid, which mediates an intermolecular transfer of EVs' cargos between blastocysts and endometrium. Emerging evidences indicate that several events like imbalance in the release of endometrial or placenta-derived EVs (exosomes/MVs), uptake of their content, failure of embryo selection might lead to implantation failure. Here in this review, we have discussed the current knowledge of the involvement of EVs in maternal-fetal communications during implantation and also highlighted the EVs' rejuvenating ability to overcome infertility-related issues. We also discussed the alteration of the EVs' cargo in different pathological conditions that lead to infertility. Therefore, this review would give a better understanding of EVs' contribution in successful embryo implantation, which could help in the development of new diagnostic tools and cell-free biologics to improve the in vivo reproductive process and to treat infertility by restoring normal reproductive functions.

Role of Extracellular Vesicles in Substance Abuse and HIV-Related Neurological Pathologies

Extracellular vesicles (EVs) are a broad, heterogeneous class of membranous lipid-bilayer vesicles that facilitate intercellular communication throughout the body. As important carriers of various types of cargo, including proteins, lipids, DNA fragments, and a variety of small noncoding RNAs, including miRNAs, mRNAs, and siRNAs, EVs may play an important role in the development of addiction and other neurological pathologies, particularly those related to HIV. In this review, we summarize the findings of EV studies in the context of methamphetamine (METH), cocaine, nicotine, opioid, and alcohol use disorders, highlighting important EV cargoes that may contribute to addiction. Additionally, as HIV and substance abuse are often comorbid, we discuss the potential role of EVs in the intersection of substance abuse and HIV. Taken together, the studies presented in this comprehensive review shed light on the potential role of EVs in the exacerbation of substance use and HIV. As a subject of growing interest, EVs may continue to provide information about mechanisms and pathogenesis in substance use disorders and CNS pathologies, perhaps allowing for exploration into potential therapeutic options.

Pathogenesis of preterm birth: bidirectional inflammation in mother and fetus

Preterm birth (PTB) complicates 5–18% of pregnancies globally and is a leading cause of maternal and fetal morbidity and mortality. Most PTB is spontaneous and idiopathic, with largely undefined causes. To increase understanding of PTB, much research in recent years has focused on using animal models to recapitulate the pathophysiology of PTB. Dysfunctions of maternal immune adaptations have been implicated in a range of pregnancy pathologies, including PTB. A wealth of evidence arising from mouse models as well as human studies is now available to support that PTB results from a breakdown in fetal-maternal tolerance, along with excessive, premature inflammation. In this review, we examine the current knowledge of the bidirectional communication between fetal and maternal systems and its role in the immunopathogenesis of PTB. These recent insights significantly advance our understanding of the pathogenesis of PTB, which is essential to ultimately designing more effective strategies for early prediction and subsequent prevention of PTB.

Extracellular Vesicles: New Endogenous Shuttles for miRNAs in Cancer Diagnosis and Therapy?

Extracellular Vesicles (EVs) represent a heterogeneous population of membranous cell-derived structures, including cargo-oriented exosomes and microvesicles. EVs are functionally associated with intercellular communication and play an essential role in multiple physiopathological conditions. Shedding of EVs is frequently increased in malignancies and their content, including proteins and nucleic acids, altered during carcinogenesis and cancer progression. EVs-mediated intercellular communication between tumor cells and between tumor and stromal cells can modulate, through cargo miRNA, the survival, progression, and drug resistance in cancer conditions. These consolidated suggestions and EVs’ stability in bodily fluids have led to extensive investigations on the potential employment of circulating EVs-derived miRNAs as tumor biomarkers and potential therapeutic vehicles. In this review, we highlight the current knowledge about circulating EVs-miRNAs in human cancer and the application limits of these tools, discussing their clinical utility and challenges in functions such as in biomarkers and instruments for diagnosis, prognosis, and therapy.

Mesenchymal stem cell-derived extracellular vesicle-based therapies protect against coupled degeneration of the central nervous and vascular systems in stroke

Stem cell-based treatments have been suggested as promising candidates for stroke. Recently, mesenchymal stem cells (MSCs) have been reported as potential therapeutics for a wide range of diseases. In particular, clinical trial studies have suggested MSCs for stroke therapy. The focus of MSC treatments has been directed towards cell replacement. However, recent research has lately highlighted their paracrine actions. The secretion of extracellular vesicles (EVs) is offered to be the main therapeutic mechanism of MSC therapy. However, EV-based treatments may provide a wider therapeutic window compared to tissue plasminogen activator (tPA), the traditional treatment for stroke. Exosomes are nano-sized EVs secreted by most cell types, and can be isolated from conditioned cell media or body fluids such as plasma, urine, and cerebrospinal fluid (CSF). Exosomes apply their effects through targeting their cargos such as microRNAs (miRs), DNAs, messenger RNAs, and proteins at the host cells, which leads to a shift in the behavior of the recipient cells. It has been indicated that exosomes, in particular their functional cargoes, play a significant role in the coupled pathogenesis and recovery of stroke through affecting the neurovascular unit (NVU). Therefore, it seems that exosomes could be utilized as diagnostic and therapeutic tools in stroke treatment. The miRs are small endogenous non-coding RNA molecules which serve as the main functional cargo of exosomes, and apply their effects as epigenetic regulators. These versatile non-coding RNA molecules are involved in various stages of stroke and affect stroke-related factors. Moreover, the involvement of aging-induced changes to specific miRs profile in stroke further highlights the role of miRs. Thus, miRs could be utilized as diagnostic, prognostic, and therapeutic tools in stroke. In this review, we discuss the roles of stem cells, exosomes, and their application in stroke therapy. We also highlight the usage of miRs as a therapeutic choice in stroke therapy.

Emerging Role of Extracellular Vesicles in Embryo-Maternal Communication throughout Implantation Processes

In ruminants, the establishment of proper conceptus–endometrial communication is essential for conceptus implantation and subsequent successful placentation. Accumulated evidence supports the idea that extracellular vesicles (EVs) present in uterine lumen are involved in conceptus–endometrial interactions during the preimplantation period. EVs make up a new field of intercellular communicators, which transport a variety of bioactive molecules, including soluble and membrane-bound proteins, lipids, DNA, and RNAs. EVs thus regulate gene expression and elicit biological effects including increased cell proliferation, migration, and adhesion in recipient cells. Uterine EVs are interactive and coordinate with ovarian progesterone (P4), trophectoderm-derived interferon tau (IFNT) and/or prostaglandins (PGs) in the physiological or pathological microenvironment. In this review, we will focus on intrauterine EVs in embryo–maternal interactions during the early stage of pregnancy, especially the implantation period in ruminant ungulates.

Isolation and characterization of human amniotic fluid-derived exosomes

Extracellular vesicles (EVs), specifically exosomes of 50-150nm, have emerged as important communication channels between cells and tissues and can be isolated from multiple biofluids including blood, urine and amniotic fluid. No standardized approach for exosome isolation from these biofluids has been established. This chapter outlines an optimized approach for isolating exosomes from human amniotic fluid samples. Like plasma, amniotic fluid contains many protein and cellular contaminants that requires multiple steps for cleanup. Therefore, to ensure samples contain minimal contaminants, including larger EVs, we also outline multiple methods for characterization of isolated exosomes for size, morphology and protein markers.

Extracellular vesicles: Novel regulators of conceptus-uterine interactions?

This review focuses on extracellular vesicles (EV) in the uterus and their potential biological roles as mediators of conceptus-uterine interactions essential for implantation and pregnancy establishment. Growing evidence supports the idea that EV are produced by both the endometrium and conceptus during pregnancy. Exosomes and microvesicles, collectively termed EV, mediate cell-cell communication in other tissues and organs. EV have distinct cargo, including lipids, proteins, RNAs, and DNA, that vary depending on the cell of origin and regulate processes including angiogenesis, adhesion, proliferation, cell survival, inflammation, and immune response in recipient cells. Molecular crosstalk between the endometrial epithelium and the blastocyst/conceptus, particularly the trophectoderm, regulates early pregnancy events and is a prerequisite for successful implantation. Trafficking of EV between the conceptus and endometrium may represent a key form of communication important for pregnancy establishment. Increased understanding of EV in the uterine environment and their physiological roles in endometrial-conceptus interactions is expected to provide opportunities to improve pregnancy success.

Extracellular vesicles: Multi-signal messengers in the gametes/embryo-oviduct cross-talk

Extracellular vesicles (EVs) have emerged as novel cell-to-cell communication mediators in physiological and pathological scenarios. Their ability to transfer their molecular cargo (RNAs, proteins and lipids) from one cell to another, in the vicinity or far from the cell of origin, together with their capacity of exerting a functional impact on the target cell make them valuable diagnostic tools as well as therapeutic vectors in a variety of diseases. In the reproductive field, there is a growing interest in the role of EVs in gamete/embryo-maternal communication and their potential implications in the reproductive success. In this review, we provide current knowledge of EVs secreted by the oviduct (oEVs) and embryos (eEVs), since both have been proposed as key players in the crucial two-way dialogue between the oviduct (lining epithelium and secretions) and the embryo that ensures successful pregnancy. Both oEVs and eEVs molecular cargos and their potential role as multi-signal messengers in the gametes/embryo-oviduct cross-talk and in the embryo-to-embryo communication in different species are also addressed. Eventually, a comparative analysis between oEVs and eEVs has been performed to shed some light on common and specific cargos responsible for their functions supporting the early reproductive events and as prime candidate molecules for improving fertility and assisted reproductive technologies outcomes.

Composition of Caenorhabditis elegans extracellular vesicles suggests roles in metabolism, immunity, and aging

The nematode Caenorhabditis elegans has been instrumental in the identification of evolutionarily conserved mechanisms of aging. C. elegans also has recently been found to have evolutionarily conserved extracellular vesicle (EV) signaling pathways. We have been developing tools that allow for the detailed study of EV biology in C. elegans. Here we apply our recently published method for high specificity purification of EVs from C. elegans to carry out target-independent proteomic and RNA analysis of nematode EVs. We identify diverse coding and non-coding RNA and protein cargo types commonly found in human EVs. The EV cargo spectrum is distinct from whole worms, suggesting that protein and RNA cargos are actively recruited to EVs. Gene ontology analysis revealed C. elegans EVs are enriched for extracellular-associated and signaling proteins, and network analysis indicates enrichment for metabolic, immune, and basement membrane associated proteins. Tissue enrichment and gene expression analysis suggests the secreted EV proteins are likely to be derived from intestine, muscle, and excretory tissue. An unbiased comparison of the EV proteins with a large database of C. elegans genome-wide microarray data showed significant overlap with gene sets that are associated with aging and immunity. Taken together our data suggest C. elegans could be a promising in vivo model for studying the genetics and physiology of EVs in a variety of contexts including aging, metabolism, and immune response.

Comprehensive landscape of extracellular vesicle-derived RNAs in cancer initiation, progression, metastasis and cancer immunology

Extracellular vesicles (EVs), a class of heterogeneous membrane vesicles, are generally divided into exosomes and microvesicles on basis of their origination from the endosomal membrane or the plasma membrane, respectively. EV-mediated bidirectional communication among various cell types supports cancer cell growth and metastasis. EVs derived from different cell types and status have been shown to have distinct RNA profiles, comprising messenger RNAs and non-coding RNAs (ncRNAs). Recently, ncRNAs have attracted great interests in the field of EV-RNA research, and growing numbers of ncRNAs ranging from microRNAs to long ncRNAs have been investigated to reveal their specific functions and underlying mechanisms in the tumor microenvironment and premetastatic niches. Emerging evidence has indicated that EV-RNAs are essential functional cargoes in modulating hallmarks of cancers and in reciprocal crosstalk within tumor cells and between tumor and stromal cells over short and long distance, thereby regulating the initiation, development and progression of cancers. In this review, we discuss current findings regarding EV biogenesis, release and interaction with target cells as well as EV-RNA sorting, and highlight biological roles and molecular mechanisms of EV-ncRNAs in cancer biology.

Thyroid tumor cells-fibroblasts crosstalk: role of extracellular vesicles

Tumor-stroma crosstalk leads to a tumor-promoting microenvironment. In this milieu, extracellular vesicles (EVs) are protagonists in cell-cell communication. Despite thyroid cancer being the most common endocrine malignancy, the contribution of the tumor microenvironment to thyroid cancer progression is still largely underexplored. We focused on the role of thyroid tumor cell-fibroblast interaction and EVs as mediators of tumor-stroma interplay, in the promotion of thyroid tumor aggressiveness. Thyroid tumor (TPC-1, 8505c) or non-tumor thyroid cells (NThyOri) were co-cultured with human fibroblasts (Fb). Thyroid cell migration was investigated by the wound-healing assay and actin-network staining. Cell-CD147 expression was characterized by flow cytometry. EVs, obtained by ultracentrifugation of conditioned media (CMs), were characterized by transmission electron-microscopy and CD81 and CD147 expression. Metalloproteinases (MMPs) were evaluated by zymography in CMs. A migratory phenotype was triggered in thyroid tumor cells treated with CMs from Fb or from Fb-thyroid tumor cell co-cultures. Fb-thyroid cell co-cultures induced the secretion of proMMP9 and proMMP2 and led to a significant MMP2 activation in CMs. Fb, thyroid cells and Fb-thyroid cell co-cultures released EVs, and remarkably, EVs released by Fb-thyroid tumor cell co-cultures induced the secretion of proMMP2 and the expression of MMP2 from normal Fb. A significant CD147 expression was demonstrated in Fb-thyroid tumor cell-derived EVs. These findings reveal the role of Fb and thyroid tumor cell-Fb interaction in the promotion of a microenvironment suitable for thyroid tumor progression. Moreover, they highlight, for the first time, the role of thyroid tumor cell-Fb interaction in the production of specialized EVs.

Exosomal miRNA-320a Is Released from hAMSCs and Regulates SIRT4 to Prevent Reactive Oxygen Species Generation in POI

Human amniotic mesenchymal stem cells (hAMSCs) were previously shown to effectively rescue ovarian function in a premature ovarian insufficiency (POI) mouse model. The therapeutic mechanism of hAMSC-derived exosomes (hAMSC-Exos) is not fully understood. In this study, the therapeutic mechanism involved in exosomal microRNA-320a (miR-320a) and Sirtuin 4 (SIRT4) was investigated in POI mouse ovaries oocytes and human granulosa cells (hGCs) by fluorescence-activated cell sorting (FACS), hematoxylin and eosin (H&E) staining, enzyme-linked immunosorbent assay (ELISA), and immunofluorescence experiments. hAMSC-Exos improved proliferation, inhibited apoptosis, and decreased the expression of SIRT4 and relative genes in POI hGCs and ovaries. hAMSC-Exos elevated ovarian function and prohibited SIRT4 expression in oogenesis. The therapeutic effects were attenuated when miR-320a was knocked down. hAMSC-Exos decreased the ROS levels in POI hGCs and oocytes and improved ovarian weight and litter size, except for the Exos^{anti-miR-320a}/POI group. Finally, hAMSC-Exos reduced the SIRT4 and ROS levels in POI ovaries and hGCs. The downstream protein expression (ANT2, AMP-dependent kinase [AMPK], and L-OPA1) was downregulated in the hGCs-SIRT4^KD group but disappeared in the Exos^{anti-miR-320a}/POI group. Our study is the first to illustrate the therapeutic potential of hAMSC-Exos in POI. Exosomal miR-320 plays a key role in the hAMSC-Exos-mediated effects on ovarian function via SIRT4 signaling.

Direct comparison of optical and electron microscopy methods for structural characterization of extracellular vesicles

As interest in the role of extracellular vesicles in cell-to-cell communication has increased, so has the use of microscopy and analytical techniques to assess their formation, release, and morphology. In this study, we evaluate scanning electron microscopy (SEM) and cryo-SEM for characterizing the formation and shedding of vesicles from human breast cell lines, parental and hyaluronan synthase 3-(HAS3)-overexpressing MCF10A cells, grown directly on transmission electron microscopy (TEM) grids. While cells imaged with conventional and cryo-SEM exhibit distinct morphologies due to the sample preparation process for each technique, tubular structures protruding from the cell surfaces were observed with both approaches. For HAS3-MCF10A cells, vesicles were present along the length of membrane protrusions. Once completely shed from the cells, extracellular vesicles were characterized using nanoparticle tracking analysis (NTA) and cryo-TEM. The size distributions obtained by each technique were different not only in the range of vesicles analyzed, but also in the relative proportion of smaller-to-larger vesicles. These differences are attributed to the presence of biological debris in the media, which is difficult to differentiate from vesicles in NTA. Furthermore, we demonstrate that cryo-TEM can be used to distinguish between vesicles based on their respective surface structures, thereby providing a path to differentiating vesicle subpopulations and identifying their size distributions. Our study emphasizes the necessity of pairing several techniques to characterize extracellular vesicles.