Exosomes Function Research Articles

Multi-Omics Analysis of Circulating Exosomes in Adherent Long-Term Treated OSA Patients.

Obstructive sleep apnea (OSA) is a highly prevalent chronic disease affecting nearly a billion people globally and increasing the risk of multi-organ morbidity and overall mortality. However, the mechanisms underlying such adverse outcomes remain incompletely delineated. Extracellular vesicles (exosomes) are secreted by most cells, are involved in both proximal and long-distance intercellular communication, and contribute toward homeostasis under physiological conditions. A multi-omics integrative assessment of plasma-derived exosomes from adult OSA patients prior to and after 1-year adherent CPAP treatment is lacking. We conducted multi-omic integrative assessments of plasma-derived exosomes from adult OSA patients prior to and following 1-year adherent CPAP treatment to identify potential specific disease candidates. Fasting morning plasma exosomes isolated from 12 adult patients with polysomnographically-diagnosed OSA were analyzed before and after 12 months of adherent CPAP therapy (mean ≥ 6 h/night) (OSAT). Exosomes were characterized by flow cytometry, transmission electron microscopy, and nanoparticle tracking analysis. Endothelial cell barrier integrity, wound healing, and tube formation were also performed. Multi-omics analysis for exosome cargos was integrated. Exosomes derived from OSAT improved endothelial permeability and dysfunction as well as significant improvement in tube formation compared with OSA. Multi-omic approaches for OSA circulating exosomes included lipidomic, proteomic, and small RNA (miRNAs) assessments. We found 30 differentially expressed proteins (DEPs), 72 lipids (DELs), and 13 miRNAs (DEMs). We found that the cholesterol metabolism (has04979) pathway is associated with lipid classes in OSA patients. Among the 12 subjects of OSA and OSAT, seven subjects had complete comprehensive exosome cargo information including lipids, proteins, and miRNAs. Multi-omic approaches identify potential signature biomarkers in plasma exosomes that are responsive to adherent OSA treatment. These differentially expressed molecules may also play a mechanistic role in OSA-induced morbidities and their reversibility. Our data suggest that a multi-omic integrative approach might be useful in understanding how exosomes function, their origin, and their potential clinical relevance, all of which merit future exploration in the context of relevant phenotypic variance. Developing an integrated molecular classification should lead to improved diagnostic classification, risk stratification, and patient management of OSA by assigning molecular disease-specific therapies.

Cargoes of exosomes function as potential biomarkers for Mycobacterium tuberculosis infection.

Exosomes as double-membrane vesicles contain various contents of lipids, proteins, mRNAs and non-coding RNAs, and involve in multiple physiological processes, for instance intercellular communication and immunomodulation. Currently, numerous studies found that the components of exosomal proteins, nucleic acids or lipids released from host cells are altered following infection with Mycobacterium tuberculosis. Exosomal contents provide excellent biomarkers for the auxiliary diagnosis, efficacy evaluation, and prognosis of tuberculosis. This study aimed to review the current literatures detailing the functions of exosomes in the procedure of M. tuberculosis infection, and determine the potential values of exosomes as biomarkers to assist in the diagnosis and monitoring of tuberculosis.

Exosomes mediate the antibody-resistant intercellular transmission of porcine epidemic diarrhea virus

Porcine epidemic diarrhea virus (PEDV) is a highly pathogenic enteric coronavirus that causes severe enteritis and lethal watery diarrhea in suckling piglets, leading to tremendous economic losses. Exosomes have been reported to participate in intercellular communication by the transportation of a variety of biological materials, including RNAs, lipids, and proteins. However, PEDV transmission routes have not yet been fully elucidated, and whether exosomes function in PEDV transmission remains unclear. In this study, we extracted and purified exosomes from PEDV-infected Vero cells using a stringent isolation method with a combination of chemical precipitation, ultracentrifugation, and incubation with CD63-labeled magnetic beads. We found that exosomes from PEDV-infected Vero cells contain viral genomic RNA and viral nucleocapsid protein. Furthermore, we demonstrated that the purified exosomes from PEDV-infected cells are capable of transmitting the virus to both PEDV-susceptible and non-susceptible cells. Importantly, exosome-mediated PEDV infection was resistant to neutralization by PEDV-specific neutralizing antibodies that potently neutralized free PEDV. Our study reveals a potential immune evasion mechanism utilized by PEDV and provides new insight into the transmission and infection of this important pathogen.

EXOSOME: EMERGING BIOMARKER FOR CANCER DIAGNOSIS AND THERAPY

Cancer is a leading cause of death worldwide and cancer incidence and mortality are rapidly growing. The prompt diagnosis and treatment for cancer require early screening. There are numerous cancer therapies have been develop such as surgery, radiotherapy, immunotherapy and chemotherapy. These treatment, however, have the ability to kill healthy cells and cause severe side effects. Exosomes are a subset of extracellular vesicles that are secreted by the dynamic, multistep endocytosis process. They transport a variety of functional molecules, including lipids, proteins, nucleic acids (DNA, messenger, and non-coding RNA), and metabolites that aid in intercellular communication. Exosomes have recently been shown to be effective diagnostic, prognostic, and predictive biomarkers. Exosomes have generated a lot of interest in the field of cancer treatment because of these qualities particularly as a biological carrier for certain drugs, inhibitors, antibodies and microRNA. Since specific content within exosomes originate from their cells of origin, this property allows exosomes to serve as valuable biomarkers. This article provides a summary of recent advances in the study of exosomal biomarkers and their role in cancer. We will also discuss the potential use of exosomes as diagnostic and prognostic biomarkers or predictors for various cancer therapeutic strategies. We also provide a brief overview of exosomes formation and function.

Regulatory mechanism of DHRS2-modified human umbilical cord mesenchymal stem cells-derived exosomes in prostate cancer cell proliferation and apoptosis

Prostate cancer (PCa) is a prevalent cause of morbidity and mortality. DHRS2-modified human umbilical cord mesenchymal stem cells-derived exosomes (hUC-MSCs-derived exos) function in PCa. We explored the mechanism of DHRS2-modified hUC-MSCs-derived exos in PCa cell malignant behaviors. DHRS2 expression levels in WPMY-1 cells and 4 PCa cell lines were detected by RT-qPCR and Western blot. 22Rv1/DU145 cells with high/low DHRS2 expression were selected to establish the low/high DHRS2 expression models by transfection. Cell proliferation and apoptosis were detected by CCK-8, colony formation assays, and flow cytometry. hUC-MSCs were identified by oil red O, alizarin staining, and flow cytometry. Exos were extracted from hUC-MSCs by ultracentrifugation and identified by transmission electron microscopy, Nano series-Nano-ZS, and Western blot. DU145 cells were selected for in vitro study to further study the effects of DHRS2-modified exos on cell proliferation and apoptosis. The effect of DHRS2-modified exos on cell cycle distribution was detected by flow cytometry. DHRS2 was repressed in PCa cells. DHRS2 overexpression suppressed PCa cell proliferation and promoted apoptosis. Exos were successfully isolated from hUC-MSC. DHRS2-modified hUC-MSCs-derived exos carried DHRS2 into PCa cells and blocked malignant behaviors. Briefly, DHRS2 was repressed in PCa cells. DHRS2-modified hUC-MSCs-derived exos blocked PCa cell proliferation and enhanced apoptosis.

Exosomes in osteoarthritis: Updated insights on pathogenesis, diagnosis, and treatment.

Osteoarthritis (OA) has remained a prevalent public health problem worldwide over the past decades. OA is a global challenge because its specific pathogenesis is unclear, and no effective disease-modifying drugs are currently available. Exosomes are small and single-membrane vesicles secreted via the formation of endocytic vesicles and multivesicular bodies (MVBs), which are eventually released when MVBs fuse with the plasma membrane. Exosomes contain various integral surface proteins derived from cells, intercellular proteins, DNAs, RNAs, amino acids, and metabolites. By transferring complex constituents and promoting macrophages to generate chemokines and proinflammatory cytokines, exosomes function in pathophysiological processes in OA, including local inflammation, cartilage calcification and degradation of osteoarthritic joints. Exosomes are also detected in synovial fluid and plasma, and their levels continuously change with OA progression. Thus, exosomes, specifically exosomal miRNAs and lncRNAs, potentially represent multicomponent diagnostic biomarkers for OA. Exosomes derived from various types of mesenchymal stem cells and other cell or tissue types affect angiogenesis, inflammation, and bone remodeling. These exosomes exhibit promising capabilities to restore OA cartilage, attenuate inflammation, and balance cartilage matrix formation and degradation, thus demonstrating therapeutic potential in OA. In combination with biocompatible and highly adhesive materials, such as hydrogels and cryogels, exosomes may facilitate cartilage tissue engineering therapies for OA. Based on numerous recent studies, we summarized the latent mechanisms and clinical value of exosomes in OA in this review.

Retraction: Exosomes function as nanoparticles to transfer miR-199a-3p to reverse chemoresistance to cisplatin in hepatocellular carcinoma.

This Retraction follows an Expression of Concern relating to this article previously published by Portland Press.This article is being retracted from Bioscience Reports at the request of the authors following receipt of a notification from a reader, alerting the Editorial Office to potential issues surrounding the scientific validity of this paper, including identical image panels that appear across multiple publications. Figure panels 3C and 3D contains identical images with the following papers: ‘The Long Non-coding RNA LINC01705 Regulates the Development of Breast Cancer by Sponging miR-186-5p to Mediate TPR Expression as a Competitive Endogenous RNA’ (Figure 7C and 7D respectively; https://doi.org/10.3389/fgene.2020.00779), ‘Circular RNA circ-0016068 Promotes the Growth, Migration, and Invasion of Prostate Cancer Cells by Regulating the miR-330-3p/BMI-1 Axis as a Competing Endogenous RNA’ (Figure 2C and 2D respectively; https://doi.org/10.3389/fcell.2020.00827), and ‘LncRNA SNHG4 promotes osteosarcoma proliferation and migration by sponging miR‐377‐3p’ (Figure 2D; https://doi.org/10.1002%2Fmgg3.1349). Figure panels 3E and 3F share identical images with those of article ‘Long Non-Coding RNA ELFN1-AS1 Promoted Colon Cancer Cell Growth and Migration via the miR-191-5p/Special AT-Rich Sequence-Binding Protein 1 Axis’ (Figure 3C; (https://doi.org/10.3389%2Ffonc.2020.588360). The authors wish to retract the article. The Editor-in-Chief and Editorial Board agree with the retraction.

Expression of Concern: Exosomes function as nanoparticles to transfer miR-199a-3p to reverse chemoresistance to cisplatin in hepatocellular carcinoma.

The Editorial Office has been made aware of potential issues surrounding the scientific validity of this paper, including identical image panels that appear across multiple publications. Figure panels 3C and 3D contains identical images with the following papers: ‘The Long Non-coding RNA LINC01705 Regulates the Development of Breast Cancer by Sponging miR-186-5p to Mediate TPR Expression as a Competitive Endogenous RNA’ (Figure panels 7C and 7D respectively; https://doi.org/10.3389/fgene.2020.00779), ‘Circular RNA circ-0016068 Promotes the Growth, Migration, and Invasion of Prostate Cancer Cells by Regulating the miR-330-3p/BMI-1 Axis as a Competing Endogenous RNA’ (Figure 2C and 2D respectively; https://doi.org/10.3389/fcell.2020.00827), and ‘LncRNA SNHG4 promotes osteosarcoma proliferation and migration by sponging miR‐377‐3p’ (Figure 2D; https://doi.org/10.1002%2Fmgg3.1349). Figure panels 3E and 3F share identical images with those of article ‘Long Non-Coding RNA ELFN1-AS1 Promoted Colon Cancer Cell Growth and Migration via the miR-191-5p/Special AT-Rich Sequence-Binding Protein 1 Axis’ Figure panel 3C (https://doi.org/10.3389%2Ffonc.2020.588360). The authors have been contacted with regards to these concerns.

Exosomes: Key tools for cancer liquid biopsy

Precision medicine is based on the identification of biomarkers of tumor development and progression. Liquid biopsy is at the forefront of the ability to gather diagnostic and prognostic information on tumors, as it can be noninvasively performed prior or during treatment. Liquid biopsy mostly utilizes circulating tumor cells, or free DNA, but also exosomes. The latter are nanovesicles secreted by most cell types, found in any body fluid that deliver proteins, nucleic acids and lipids to nearby and distant cells with a unique homing ability. Exosomes function in signalling between the tumor microenvironment and the rest of the body, promoting metastasis, immune remodelling and drug resistance. Exosomes are emerging as a key tool in precision medicine for cancer liquid biopsy, as they efficiently preserve their biomarker cargo. Moreover, exosomes strongly resemble the parental cell, which can help in assessing the oxidative and metabolic state of the donor cell. In this respect, exosomes represent one of the most promising new tools to fight cancer. This review will discuss the clinical applications of profiling exosomal proteins and lipids by high-throughput proteomics and metabolomics, and nucleic acids by next generation sequencing, as well as how this may allow cancer diagnosis, therapy response monitoring and recurrence detection.

Exosomes Secreted from Amniotic Membrane Contribute to Its Anti-Fibrotic Activity.

Amniotic membranes (AM) have anti-fibrotic activity. Exosomes (nano-sized vesicles) function as conduits for intercellular transfer and contain all the necessary components to induce the resolution of fibrosis. In this study, we tested the hypothesis that the anti-fibrotic activity of AM is mediated by exosomes. AM-derived exosomes or amniotic stromal cell-derived exosomes were isolated and characterized. Anti-fibrotic activity of exosomes was evaluated using human hepatic stellate cells (LX-2), an in vitro model of fibrosis. Exosomes isolated from AM tissue-conditioned media had an average size of 75 nm. Exosomes significantly inhibited the proliferation of TGFβ1-activated LX-2 but had no effect on the proliferation of non-activated LX-2 cells. Exosomes also reduced the migration of LX-2 in a scratch wound assay. Furthermore, exosomes reduced the gene expression of pro-fibrotic markers such as COL1A1, ACTA, and TGFβ1 in LX-2 cells. Interestingly, exosomes isolated from AM tissue under hypoxic conditions seemed to show a stronger anti-fibrotic activity than exosomes isolated from tissue under normoxic conditions. Exosomes released by in vitro cultured AM stromal cells were smaller in size compared with tissue exosomes and also showed anti-fibrotic activity on LX-2 cells. In conclusion, AM-tissue-released exosomes contribute to the anti-fibrotic activity of AM. This is the first report of isolation, characterization, and functional evaluation of exosomes derived from amniotic tissues with the direct comparison between tissue-derived exosomes and cultured cell-derived exosomes.

EMT Participates in the Regulation of Exosomes Secretion and Function in Esophageal Cancer Cells.

Epithelial-mesenchymal transition (EMT) is a key step in tumor invasion and distant metastasis. Abundant evidence has documented that exosomes can mediate EMT of tumor cells and endow them with the ability of invasion and migration. However, there are few studies focusing on whether EMT can reverse the secretion of exosomes. In this study, 2 esophageal cancer cells (FLO-1 and SK-GT-4) were selected to compare the migration ability and EMT activation, and to further analyze the secretion ability of exosomes of the 2 cell lines. According to the results, inhibited activation of EMT in FLO-1 cells with relatively high migration ability could effectively reduce the secretion of exosomes. Besides, in SK-GT-4 cells, EMT activation induced by TGF-β could promote the secretion of exosomes. FLO-1 cell derived exosomes exhibited a paracrine effect of promoting the migration of SK-GT-4 cells, and the use of EMT inhibitors could weaken this ability. Furthermore, inhibition of EMT could change the relative content of some miRNAs in exosomes, with a particularly significant downregulation in the expression of miR-196-5p, miR-21-5p and miR-194-5p. Significantly, artificial transfection of the 3 miRNAs into exosomes by electroporation resulted in the recovery of migration-promoting effect of exosomes. Subsequent experiments further revealed that the effect of EMT on these miRNAs could be explained by the intracellular transcription level or the specific sorting mechanism of exosomes. To sum up, our study undoubtedly reveals that EMT has a regulatory effect on exosomes in the quantity and contents in esophageal cancer cells. Significantly, findings in our study provide experimental evidence for the interaction of EMT with the secretion and sorting pathway of exosomes, and also give a new direction for the further study of tumor metastasis.

Radiation Can Regulate the Expression of miRNAs Associated with Osteogenesis and Oxidation in Exosomes from Peripheral Blood Plasma.

Objectives Radiotherapy is a common therapy in head and neck tumors, which may cause a side effect radiation bone injury (RBI). Furthermore, it has been investigated that microRNA (miRNA) expression levels were altered after radiotherapy. Exosomes play a role in bone formation as miRNA containers, while radiation affects exosomes composition, secretion, and function. So, our objective is to explore changes in miRNA levels during bone formation after radiotherapy and identify the differentially expressed miRNAs (DE-miRs) in plasma exosomes during the process of osteogenesis related to irradiation. Materials and Methods In this study, we analyzed nine samples from three rabbits exposed twice to radiation (15 Gy each) and detected DE-miRs from irradiated plasma exosomes during the process of osteogenesis by RNA sequencing. Further, we identified DE-miRs with significant differences and predicted their target genes via the bioinformatics analysis tools Targetscan v7.2 and miRPathDB v2.0. Finally, we identified radiation-responsive miRNAs and predicted their target genes during osteogenesis. Results Taken together, we have identified some DE-miRs in irradiated plasma exosomes, which were involved in several vital signaling pathways related to bone physiology, such as the Wnt pathway, MAPK cascade, and calcium modulating pathway. Conclusions We have found that plasma exosomes are one of the ways by which radiation can affect bone metabolism and regeneration. However, the specific mechanisms of how these plasma exosomal miRNAs mediate the osteogenesis pathways must be further investigated. Clinical Relevance. Radiotherapy may cause radiation bone injury, and miRNA expression levels in rabbit plasma exosomes are altered after radiotherapy. High-throughput RNA sequencing can identify the differentially expressed miRNAs in irradiated plasma exosomes during the process of osteogenesis. These findings make sense to develop novel therapeutic strategies for treating radiation-induced bone injury disorders.

Effects of the Oncoprotein PAX3-FOXO1 on Modulation of Exosomes Function and Protein Content: Implications on Oxidative Stress Protection and Enhanced Plasticity.

Rhabdomyosarcoma (RMS) is a highly malignant soft tissue sarcoma classified into two major histologic subtypes: embryonal (ERMS) and alveolar (ARMS). ARMS subtype is clinically more aggressive, and characterized by an oncogenic fusion protein PAX3-FOXO1 (P3F) that drives oncogenic cellular properties. To understand the role of the fusion oncoprotein in paracrine signaling, we focused on secreted exosomes, which have been demonstrated to contribute to metastasis in multiple tumor types. Advanced Proteomics-bioinformatics analysis of the protein cargo of exosomes isolated from C2C12 myoblasts transduced with P3F fusion gene revealed 52 deregulated proteins compared to control cells, with 26 enriched and 26 depleted proteins. Using both PANTHER gene classification and Ingenuity Pathway Analysis (IPA) software, we found that the main biological processes in which the 52 deregulated proteins are involved, include “catalytic activity,” “binding,” “metabolic process,” and “cellular process.” The pathways engaging the 26 enriched proteins include the “14-3-3 mediated signaling,” “cell cycle,” and “ERK5, VEGF, IGF1,and p70S6K signaling.” Furthermore, the main nodes in which deregulated exosome proteins and miRNAs intersected revealed pathways conferring protection from stress and promoting plasticity. Based on the bioinformatics analysis and the altered exosome proteome profile, we performed biochemical functional analysis to study the diverse properties of these exosomes where angiogenesis, stemness, and anti-oxidative stress properties were validated using different platforms. P3F-modulated exosomes activated ERK, 4-EBP1, and MMP-2 in recipient cells, and enhanced angiogenesis and stemness. In addition, P3F led to lower cellular reactive oxygen species levels and enhanced resistance against oxidative stress; and treatment of stromal cells with P3F-modulated exosomes also conferred protection against exogenous oxidative stress. Our findings highlight the role of P3F fusion protein in modulating exosome cargo to confer a protective effect on recipient cells against oxidative stress and to promote plasticity and survival, potentially contributing to the known aggressive phenotype of the fusion gene-positive subtype of RMS.

Osteocyte-derived exosomes induced by mechanical strain promote human periodontal ligament stem cell proliferation and osteogenic differentiation via the miR-181b-5p/PTEN/AKT signaling pathway

BackgroundThe oral cavity is a complex environment in which periodontal tissue is constantly stimulated by external microorganisms and mechanical forces. Proper mechanical force helps maintain periodontal tissue homeostasis, and improper inflammatory response can break the balance. Periodontal ligament (PDL) cells play crucial roles in responding to these challenges and maintaining the homeostasis of periodontal tissue. However, the mechanisms underlying PDL cell property changes induced by inflammatory and mechanical force microenvironments are still unclear. Recent studies have shown that exosomes function as a means of cell-cell and cell-matrix communication in biological processes.MethodsHuman periodontal ligament stem cells (HPDLSCs) were tested by the CCK8 assay, EdU, alizarin red, and ALP staining to evaluate the functions of exosomes induced by a mechanical strain. MicroRNA sequencing was used to find the discrepancy miRNA in exosomes. In addition, real-time PCR, FISH, luciferase reporter assay, and western blotting assay were used to investigate the mechanism of miR-181b-5p regulating proliferation and osteogenic differentiation through the PTEN/AKT pathway.ResultsIn this study, the exosomes secreted by MLO-Y4 cells exposed to mechanical strain (Exosome-MS) contributed to HPDLSC proliferation and osteogenic differentiation. High-throughput miRNA sequencing showed that miR181b-5p was upregulated in Exosome-MS compared to the exosomes derived from MLO-Y4 cells lacking mechanical strain. The luciferase reporter assay demonstrated that miR-181b-5p may target phosphatase tension homolog deletion (PTEN). In addition, PTEN was negatively regulated by overexpressing miR-181b-5p. Real-time PCR and western blotting assay verified that miR-181b-5p enhanced the protein kinase B (PKB, also known as AKT) activity and improved downstream factor transcription. Furthermore, miR-181b-5p effectively ameliorated the inhibition of HPDLSC proliferation and promoted HPDLSC induced by inflammation.ConclusionsThis study concluded that exosomes induced by mechanical strain promote HPDLSC proliferation via the miR-181b-5p/PTEN/AKT signaling pathway and promote HPDLSC osteogenic differentiation by BMP2/Runx2, suggesting a potential mechanism for maintaining periodontal homeostasis.

Exosomes function as nanoparticles to transfer miR-199a-3p to reverse chemoresistance to cisplatin in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a frequently seen malignant tumor globally. The occurrence of cisplatin (DDP) resistance is one of the main reasons for the high mortality of HCC patients. Therefore, it is of great theoretical significance and application value to explore the mechanism of chemotherapy resistance. Drug resistance can be modulated by exosomes containing mRNAs, micro RNAs (miRNAs) and other non-coding RNA (ncRNAs). Exosomal miR-199a-3p (Exo-miR-199a-3p) was subjected to extraction and verification. Whether exo-miR-199a-3p could make HCC cells sensitive to DDP in vitro was verified via flow cytometry, Cell Counting Kit-8 (CCK-8) assay, immunofluorescence assay and Transwell assay. Intravenous injection of exo-miR-199a-3p and intraperitoneal injection of DDP were carried out in vivo. Moreover, the possible targets of miR-199a-3p were screened through bioinformatics analysis, which were ascertained by Western blotting (WB). Then, miR-199a-3p levels in human normal liver epithelial cell line HL-7702 and HCC cell lines HuH7 and HuH7/DDP were elevated in a concentration-dependent manner. Exo-miR-199a-3p has abilities to adjust underlying targets and conjugate cells, to repress cells to invade, stimulate their apoptosis and abate their ability. Additionally, the caudal injection of exo-miR-199a-3p reversed the chemoresistance of tumors and slowed down their growth in the body owing to the up-regulation of miR-199a-3p and down-regulation of underlying target proteins in tumors. Finally, exo-miR-199a-3p was found to overturn the HCC’s resistance to DDP, and it may function in DDP-refractory HCC therapy as an underlying option in the future.

Effect of microvesicles from Moringa oleifera containing miRNA on proliferation and apoptosis in tumor cell lines

Human microvesicles are key mediators of cell–cell communication. Exosomes function as microRNA transporters, playing a crucial role in physiological and pathological processes. Plant microvesicles (MVs) display similar features to mammalian exosomes, and these MVs might enhance plant microRNA delivery in mammals. Considering that plant microRNAs have been newly identified as bioactive constituents in medicinal plants, and that their potential role as regulators in mammals has been underlined, in this study, we characterized MVs purified from Moringa oleifera seeds aqueous extract (MOES MVs) and used flow cytometry methods to quantify the ability to deliver their content to host cells. The microRNAs present in MOES MVs were characterized, and through a bioinformatic analysis, specific human apoptosis-related target genes of plant miRNAs were identified. In tumor cell lines, MOES MVs treatment reduced viability, increased apoptosis levels associated with a decrease in B-cell lymphoma 2 protein expression and reduced mitochondrial membrane potential. Interestingly, the effects observed with MOES MVs treatment were comparable to those observed with MOES treatment and transfection with the pool of small RNAs isolated from MOES, used as a control. These results highlight the role of microRNAs transported by MOES MVs as natural bioactive plant compounds that counteract tumorigenesis.

CLL-Derived Exosomes Function As Trojan Horses That Induce SMAD6-Dependent Apoptosis of Normal B-Cells

Studies from recent years unraveled the role of monocytes and T-cells in the pathogenesis of chronic lymphocytic leukemia (CLL). The role of other immune cells in the pathobiology of CLL is less known. Specifically, whether B-cells, the normal counterpart of CLL cells play a role in CLL is unknown. Nevertheless, since both CLL cells and wild type B-cells reside in lymphatic organs and travel in blood, they either share or compete over common environmental resources. According to the cell competition theory, a sensing mechanism measures the relative fitness of a cell and ensures the elimination of cells deemed to be less fit then their neighbors. Since constitutive activation of intracellular pathways protect CLL cells from apoptosis, the cell competition theory predicts that compared with normal B-cells these cells are sensed as "super fit" and B-cells, the less fit counterparts, are eliminated. Yet, what delivers this massage across a population of cells is unknown. Exosomes are nanosized particles that are secreted by various types of cells. Exosomes carry a cargo of proteins and different types of RNA. They travel in body fluids and are taken up by cells in their vicinity. Since cancer cells including CLL cells secrete exosomes, we have formulated our hypothesis, namely, that exosomes derived from CLL cells are the vehicles that carry a death massage to wild type B-cells. To test this hypothesis, we isolated CLL cells from 3 previously untreated patients with CLL. We then grew these cells in exosome free media for 72 hours and harvested the exosomes by ultracentrifugation. We used NanoSight tracking analysis, Western immunoblotting for CD63, a common exosomal marker, and electron microscopy imaging studies to ensure that our pellet include the typical 100nm exosomal particles. Subsequently, we subjected normal B-cells derived from healthy volunteers to CLL derived exosomes stained by FM-143 dye. Using flow cytometry we found that exosomes are taken up by normal B-cells in a dose- and time- dependent manner. Double staining of the recipient B-cells to Annexin/PI revealed that exosomes induce apoptosis of these cells in a dose- and time- dependent manner. We then used RNA-seq to trace the changes in the molecular makeup of B-cells after exosomal uptake?? they took up exosomes. We found 24 transcripts that were differentially expressed (11 that were upregulated and 13 that were downregulated). We then verified the array results by quantitative real-time PCR for four of these genes. Among the top transcripts that were upregulated in exosome-positive B-cells is SMAD6. Because the upregulation of the SMAD family members including SMAD6 is associated with the induction of apoptosis in various malignant and non-malignant cells we wondered whether the upregulation of SMAD6 also induces apoptosis in normal B-cells. To test this, we transfected normal B-cells with SMAD6 containing vector and verified by RT-PCR that level of SMAD6 transcript were upregulated and by Western immunoblotting that levels of SMAD6 protein are upregulated as well. As expected, the rate of apoptosis was higher, and the rates of viable cells and proliferating cells were significantly lower in SMAD6-transfected B-cells. Taken together, we show here that CLL cells secrete exosomes that function as "Trojan horses". Once they are taken up by normal B-cells they induce SMAD6-dependent apoptosis. In this way the neoplastic cells may actively eliminate their competitors and take over the common environmental resources. Disclosures No relevant conflicts of interest to declare.

Elevated Levels of Serum Exosomes in Patients with Major Depressive Disorder

Exosomes are small (30–100 nm) vesicles of the endocytic membrane that may be found in the endosome system of multivesicular organs and are released after fusion of multivesicular bodies with the plasma membrane. Exosomes function as carriers for specific loads and are stable in biological fluids; hence, exosomes are considered as potential biomarkers of different diseases. The degree of involvement and functional significance of exosomes in pathogenesis of depression have been poorly studied. The development of diagnostic methods for depressive disorders based on the analysis of circulating exosomes is very promising, despite the methodological complications related to their isolation and identification. The purpose of this study was to isolate exosomes from the blood serum of patients with major depressive disorder (MDD) and compare them with healthy volunteers using different methods of evaluation. The concentration of serum exosomes assessed using the methods of dynamic light scattering, nanoparticle tracking analysis, and the enzyme-linked immunoassay was statistically elevated in patients with MDD compared to healthy volunteers. The possible connection between the increased level of serum exosomes with the cell-mediated immune activation that is seen in depression is discussed.

The Mechanism of Exosomes Function in Neurological Diseases: A Progressive Review.

Exosomes are extracellular microparticles (≈30-100 nm in diameter) secreted from nearly all types of cells, containing a whole set of biological information including proteins, ribonucleic acid (RNA) and lipids. Latest studies show that exosomes contribute to cell-cell communication and are considered closely related with the modulation of angiogenesis and neurogenesis in many neurological diseases. In the past decade, numerous researchers were devoted to exosomes study, but the mechanism of exosomes function and delivery is uncertain. In this review, we summarized several potential mechanisms of exosomes function in angiogenesis, neurogenesis and Blood Brain Barrier (BBB) delivery, and differentiate various sources of exosomes in stroke, tumor, Traumatic Brain Injury (TBI) and Alzheimer's Disease (AD) aimed to report the most advanced mechanical theories in related past three years to provide a new sight for this research area.

Moderate Exercise Enhances Endothelial Progenitor Cell Exosomes Release and Function.

Exercise has cardiovascular benefits which might be related to endothelial progenitor cells (EPC). Meanwhile, there is evidence suggesting that EPC-derived exosomes (EPC-EX) promote vascular repair and angiogenesis through their carried microRNA (miR)-126. In this study, we investigated whether exercise could increase the levels of circulating EPC-EX and their miR-126 cargo, and by which promote the protective function of EPC-EX on endothelial cells (EC). Plasma EPC-EX from sedentary, low, or moderate exercise mice, respectively, denoted as EPC-EX, EPC-EX, and EPC-EX, were isolated using microbead-based sorting techniques and characterized by nanoparticle tracking analysis, Western blot, and quantitative real-time polymerase chain reaction assessments of biomarkers and miR-126. High glucose (25 mM) with hypoxia (1% O2) was used for inducing an EC injury model. The injured EC were treated by coculturing with vehicle, EPC-EX, EPC-EX, EPC-EX, or EPC-EX + anti-miR-126. After that, EC were used for flow cytometry analysis of apoptosis, assessments of tube formation and migration, and measurements of miR-126 level and its downstream sprouty-related protein-1 (SPRED1) and vascular endothelial growth factor (VEGF). 1) Isolated EPC-EX positively expressed exosomal markers (CD63 and Tsg101) and EPC markers (CD34 and VEGFR2). 2) Exercise intensity dependently elevated plasma level of EPC, EPC-EX/EPC ratio, and miR-126 expression in EPC and EPC-EX. 3) Injured EC displayed apoptosis increment, angiogenic dysfunction and miR-126 reduction. 4) EPC-EX had better effects than EPC-EX and EPC-EX on alleviating those changes of injured EC, accompanied with SPRED1 downregulation and VEGF upregulation. 5) The effects of EPC-EX were abolished by miR-126 knockdown. Our data demonstrate that exercise can increase EPC-EX release and miR-126 level and enhance the effects of EPC-EX on protecting EC against injury through the SPRED1/VEGF pathway.