A Comparative Study of Serum Exosome Isolation Using Differential Ultracentrifugation and Three Commercial Reagents. PLoS One. 2017;12:e0170628. [PMID: 28114422 PMCID: PMC5256994 DOI: 10.1371/journal.pone.0170628]

Combination of precipitation and size exclusion chromatography as an effective method for exosome like extracellular vesicle isolation from pericardial fluids

Extracellular vesicles (EVs), such as exosomes, are nanovesicles that have received significant attention due to their ability to contain various molecular cargos. EVs found in biological fluids have been demonstrated to have therapeutic potential, including as biomarkers. Despite being extensively studied, a significant downfall in EV research is the lack of standardised protocol for its isolation from human biological fluids, where EVs usually exist at low densities. In this study, we tested two well-established EV isolation protocols, precipitation, and size exclusion chromatography (SEC), to determine their efficiency in isolating EVs from the pericardial fluid. Precipitation alone resulted in high yields of low-purity exosomes as tested by DLS analysis, transmission electron microscopy, immunogold labelling and western blotting for the exosomal surface proteins. While EVs isolated by SEC were pure, the concentration was low. Interestingly, the combination of precipitation followed by SEC resulted in high EV yields with good purity. Our results suggest that the combination method can be adapted to isolate EVs from body fluids which have low densities of EV.

Analysis and Biomedical Applications of Functional Cargo in Extracellular Vesicles

Extracellular vesicles (EVs) can facilitate essential communication among cells in a range of pathophysiological conditions including cancer metastasis and progression, immune regulation, and neuronal communication. EVs are membrane-enclosed vesicles generated through endocytic origin and contain many cellular components, including proteins, lipids, nucleic acids, and metabolites. Over the past few years, the intravesicular content of EVs has proven to be a valuable biomarker for disease diagnostics, involving cancer, cardiovascular diseases, and central nervous system diseases. This review aims to provide insight into EV biogenesis, composition, function, and isolation, present a comprehensive overview of emerging techniques for EV cargo analysis, highlighting their major technical features and limitations, and summarize the potential role of EV cargos as biomarkers in disease diagnostics. Further, progress and remaining challenges will be discussed for clinical diagnostic outlooks.

The Convergence of FTIR and EVs: Emergence Strategy for Non-Invasive Cancer Markers Discovery

In conjunction with imaging analysis, pathology-based assessments of biopsied tissue are the gold standard for diagnosing solid tumors. However, the disadvantages of tissue biopsies, such as being invasive, time-consuming, and labor-intensive, have urged the development of an alternate method, liquid biopsy, that involves sampling and clinical assessment of various bodily fluids for cancer diagnosis. Meanwhile, extracellular vesicles (EVs) are circulating biomarkers that carry molecular profiles of their cell or tissue origins and have emerged as one of the most promising biomarkers for cancer. Owing to the biological information that can be obtained through EVs' membrane surface markers and their cargo loaded with biomolecules such as nucleic acids, proteins, and lipids, EVs have become useful in cancer diagnosis and therapeutic applications. Fourier-transform infrared spectroscopy (FTIR) allows rapid, non-destructive, label-free molecular profiling of EVs with minimal sample preparation. Since the heterogeneity of EV subpopulations may result in complicated FTIR spectra that are highly diverse, computational-assisted FTIR spectroscopy is employed in many studies to provide fingerprint spectra of malignant and non-malignant samples, allowing classification with high accuracy, specificity, and sensitivity. In view of this, FTIR-EV approach carries a great potential in cancer detection. The progression of FTIR-based biomarker identification in EV research, the rationale of the integration of a computationally assisted approach, along with the challenges of clinical translation are the focus of this review.

Advances in exosome analysis

There is growing demand for novel biomarkers that detect early stage disease as well as monitor clinical management and therapeutic strategies. Exosome analysis could provide the next advance in attaining that goal. Exosomes are membrane encapsulated biologic nanometric-sized particles of endocytic origin which are released by all cell types. Unfortunately, exosomes are exceptionally challenging to characterize with current technologies. Exosomes are between 30 and 200nm in diameter, a size that makes them out of the sensitivity range to most cell-oriented sorting or analysis platforms, i.e., traditional flow cytometers. The most common methods for targeting exosomes to date typically involve purification followed by the characterization and the specific determination of their cargo. The whole procedure is time consuming, requiring thus skilled personnel as well as laboratory facilities and benchtop instrumentation. The most relevant methodology for exosome isolation, characterization and quantification is addressed in this chapter, including the most up-to-date approaches to explore the potential usefulness of exosomes as biomarkers in liquid biopsies and in advanced nanomedicine.

Nebulization of extracellular vesicles: A promising small RNA delivery approach for lung diseases

Small extracellular vesicles (sEVs) are a group of cell-secreted nanovesicles with a diameter up to 200 nm. A growing number of studies have indicated that sEVs can reflect the pathogenesis of human diseases and mediate intercellular communications. Recently, sEV research has drastically increased due to their drug delivery property. However, a comprehensive method of delivering exogenous small RNAs-loaded sEVs through nebulization has not been reported. The methodology is complicated by uncertainty regarding the integrity of sEVs after nebulization, the delivery efficiency of aerosolized sEVs, their deposition in the lungs/cells, etc. This study demonstrates that sEVs can be delivered to murine lungs through a vibrating mesh nebulizer (VMN). In vivo sEV tracking indicated that inhaled sEVs were distributed exclusively in the lung and localized primarily in lung macrophages and airway epithelial cells. Additionally, sEVs loaded with small RNAs were successfully delivered into the lungs. The administration of siMyd88-loaded sEVs through inhalation reduced lipopolysaccharide (LPS)-induced lung injury in mice, supporting an application of this nebulization methodology to deliver functional small RNAs. Collectively, our study proposes a novel method of sEVs-mediated small RNA delivery into the murine lung through nebulization and presents a potential sEV-based therapeutic strategy for human lung diseases.

Cancer cell-derived exosomal miR-425-3p induces white adipocyte atrophy

White adipose tissue wasting plays a critical role in the development and progression of cancer cachexia. However, the mechanism behind the loss of adipose tissue remains ill-defined. In this study, we found that cancer cell-derived exosomes highly expressed miR-425-3p. Administration of cancer cell-derived exosomes significantly inhibited proliferation and differentiation of human preadipocytes-viscereal (HPA-v) cells. In mature adipocytes, cancer cell-derived exosomes activated cAMP/PKA signalling and lipophagy, leading to adipocyte lipolysis and browning of white adipocytes. These exosomes-induced alterations were almost abolished by endocytosis inhibitor cytochalasin D (CytoD) and antagomiR-425-3p, or reproduced by miR-425-3p mimics. In addition, bioinformatics analysis and luciferase reporter assay revealed that miR-425-3p directly targeted proliferation-related genes such as GATA2, IGFBP4, MMP15, differentiation-related gene CEBPA, and phosphodiesterase 4B gene (PDE4B). Depletion of PDE4B enhanced cAMP/PKA signalling and lipophagy, but had no effects on HPA-v proliferation and differentiation. Taken together, these results suggested that cancer cell-derived exosomal miR-425-3p inhibited preadipocyte proliferation and differentiation, increased adipocyte lipolysis, and promoted browning of white adipocytes, all of which might contribute to adipocyte atrophy and ultimately the loss of adipose tissue in cancer cachexia.

Abbreviations: ADPN: adiponectin; aP2: adipocyte protein 2 or fatty acid binding protein 4 (FABP4); BCA: bicinchoninic acid assay; BFA: bafilomycin A1; BMI: body mass index; C/EBP: CCAAT/enhancer binding protein; CEBPA: CCAAT/enhancer-binding protein-alpha; C-Exo: cancer cell-derived exosomes; CNTL: control; CREB: cAMP-response element binding protein; CytoD: cytochalasin D; ECL: chemiluminescence; GATA2: GATA Binding Protein 2; HFD: high fat diet; HSL: hormone-sensitive lipase; IGFBP4: insulin like growth factor binding protein 4; IRS-1: insulin receptor substrate-1; ISO: isoproterenol hydrochloride; KD: knockdown; KO: knock out; LC3: microtubule-associated protein 1A/1B-light chain 3; LMF: lipid mobilizing factor; LPL: lipoprotein lipase; MMP15: matrix metallopeptidase 15; Mir-Inh-C-Exo: cancer cell-derived exosomes with miR-425-3p inhibition; mTOR: mammalian target of rapamycin; Mut: mutant; N-Exo: normal cell-derived exosomes; NSCLC: non-small cell lung cancer; PBS, phosphate buffered saline; PGC-1: peroxisome proliferator-activated receptor-gamma coactivator-1; PDEs: phosphodiesterases; PKI: PKA inhibitor; PKA: cAMP-dependent protein kinase; PLIN1: Perilipin 1; PTHRP: parathyroid hormone-related protein; PVDF: polyvinylidene difluoride; shRNA: short hairpin RNA; UCP1: uncoupling protein 1; WT: wild type.

Advances in microRNA from adipose-derived mesenchymal stem cell-derived exosome: focusing on wound healing

Skin wounds are a common condition causing economic burden and they represent an urgent clinical need, especially chronic wounds. Numerous studies have been conducted on the applications of stem cell therapy in wound healing, with adipose-derived mesenchymal stem cells (ADMSCs) playing a major role since they can be isolated easily, yielding a high number of cells, the less invasive harvesting required, the longer life span and no ethical issues. However, the lack of standardized doses and protocols, the heterogeneity of clinical trials, as well as the incompatibility of the immune system limit its application. Recent studies have demonstrated that specific stem cell functions depend on paracrine factors, including extracellular vesicles, in which microRNAs in exosomes (Exo-miRNAs) are essential in controlling their functions. This paper describes the application and mechanism whereby ADMSC-Exo-miRNA regulates wound healing. ADMSC-Exo-miRNA is involved in various stages in wounds, including modulating the immune response and inflammation, accelerating skin cell proliferation and epithelialization, promoting vascular repair, and regulating collagen remodeling thereby reducing scar formation. In summary, this acellular therapy based on ADMSC-Exo-miRNA has considerable clinical potential, and provides reference values for developing new treatment strategies for wound healing.

In vitro model of predicting metastatic ability using tumor derived extracellular vesicles; beyond seed soil hypothesis

Lung cancer progression is often driven by metastasis, which has resulted in a considerable increase in lung cancer-related deaths. Cell-derived extracellular vesicles (EVs), particularly exosomes, serve key roles in cellular signal transmission via microenvironment, however, their biological relevance in cancer development and metastasis still needs to be clear. Here, we demonstrate that extracellular vesicles (EVs) derived from lung cancer bone metastatic patients exhibited a great capacity to promote the progression of lung cancer cells. We carried out a comprehensive meta-analysis to identify the gene expression profile of bone metastases using publicly available microarray datasets. Furthermore, mRNA expression of six identified genes was quantified by real time PCR in lung cancer with and without bone metastasis and healthy individual derived EVs. In addition, we utilized a very novel approach by to study how lung cancer cells uptake EVs by co-culturing EVs with lung cells. We observed that EVs obtained from bone metastases patients were efficiently ingested by lung cancer cells. Morevore, integration and uptake of these EVs lead to increased lung cancer cell proliferation, migration, invasion, and sphere formation. We discovered that EV uptake increase the expression of SPP1, CD44, and POSTN genes in lung cancer cells. The data obtained from this study, support to the possibility that circulating EVs play a significant role in the formation of the pre-metastatic niche, eventually leading to metastasis.

Engineered exosomes for studies in tumor immunology

Exosomes are a type of extracellular vesicle (EV) with diameters of 30-150 nm secreted by most of the cells into the extracellular spaces and can alter the microenvironment through cell-to-cell interactions by fusion with the plasma membrane and subsequent endocytosis and release of the cargo. Because of their biocompatibility, low toxicity and immunogenicity, permeability (even through the blood-brain barrier (BBB)), stability in biological fluids, and ability to accumulate in the lesions with higher specificity, investigators have started making designer's exosomes or engineered exosomes to carry biologically active protein on the surface or inside the exosomes as well as using exosomes to carry drugs, micro RNA, and other products to the site of interest. In this review, we have discussed biogenesis, markers, and contents of various exosomes including exosomes of immune cells. We have also discussed the current methods of making engineered and designer's exosomes as well as the use of engineered exosomes targeting different immune cells in the tumors, stroke, as well as at peripheral blood. Genetic engineering and customizing exosomes create an unlimited opportunity to use in diagnosis and treatment. Very little use has been discovered, and we are far away to reach its limits.

Organically derived exosomes as carriers of anticancer drugs and imaging agents for cancer treatment

Extracellular vesicles (EVs), is the umbrella term used for different types of vesicles produced by the cells, among which exosomes form the largest group. Exosomes perform intercellular communication by carrying several biologics from donor or parental cells and delivering them to recipient cells. Their unique cargo-carrying capacity has recently been explored for use as delivery vehicles of anticancer drugs and imaging agents. Being naturally produced, exosomes have many advantages over synthetic lipid-based nanoparticles currently being used clinically to treat cancer and other diseases. The finding of the role of exosomes in human diseases has led to numerous preclinical and clinical studies exploring their use as an amenable drug delivery vehicle and a theranostic in cancer diagnosis and treatment. However, there are certain limitations associated with exosomes, with the most important being the selection of the biological source for producing highly biocompatible exosomes on a large scale. This review article explores the various sources from which therapeutically viable exosomes can be isolated for use as drug carriers for cancer treatment. The methods of exosome isolation and the process of loading them with cancer therapeutics and imaging agents are also discussed in the follow-up sections. Finally, the article concludes with future directions for exosome-based applications in cancer diagnosis and treatment.

Progress in research on the role of exosomal miRNAs in the diagnosis and treatment of cardiovascular diseases

Cardiovascular diseases are the most common diseases threatening the health of the elderly, and the incidence and mortality rates associated with cardiovascular diseases remain high and are increasing gradually. Studies on the treatment and prevention of cardiovascular diseases are underway. Currently, several research groups are studying the role of exosomes and biomolecules incorporated by exosomes in the prevention, diagnosis, and treatment of clinical diseases, including cardiovascular diseases. Now, based on the results of published studies, this review discusses the characteristics, separation, extraction, and identification of exosomes, specifically the role of exosomal miRNAs in atherosclerosis, myocardial injury and infarction, heart failure, aortic dissection, myocardial fibrosis, ischemic reperfusion, atrial fibrillation, and other diseases. We believe that the observations noted in this article will aid in the prevention, diagnosis, and treatment of cardiovascular diseases.

Multiplex Analysis of CircRNAs from Plasma Extracellular Vesicle-Enriched Samples for the Detection of Early-Stage Non-Small Cell Lung Cancer

BACKGROUND

The analysis of liquid biopsies brings new opportunities in the precision oncology field. Under this context, extracellular vesicle circular RNAs (EV-circRNAs) have gained interest as biomarkers for lung cancer (LC) detection. However, standardized and robust protocols need to be developed to boost their potential in the clinical setting. Although nCounter has been used for the analysis of other liquid biopsy substrates and biomarkers, it has never been employed for EV-circRNA analysis of LC patients.

METHODS

EVs were isolated from early-stage LC patients (n = 36) and controls (n = 30). Different volumes of plasma, together with different number of pre-amplification cycles, were tested to reach the best nCounter outcome. Differential expression analysis of circRNAs was performed, along with the testing of different machine learning (ML) methods for the development of a prognostic signature for LC.

RESULTS

A combination of 500 μL of plasma input with 10 cycles of pre-amplification was selected for the rest of the study. Eight circRNAs were found upregulated in LC. Further ML analysis selected a 10-circRNA signature able to discriminate LC from controls with AUC ROC of 0.86.

CONCLUSIONS

This study validates the use of the nCounter platform for multiplexed EV-circRNA expression studies in LC patient samples, allowing the development of prognostic signatures.

The multiple faces of extracellular vesicles released by microglia: Where are we 10 years after?

As resident component of the innate immunity in the central nervous system (CNS), microglia are key players in pathology. However, they also exert fundamental roles in brain development and homeostasis maintenance. They are extremely sensitive and plastic, as they assiduously monitor the environment, adapting their function in response to stimuli. On consequence, microglia may be defined a heterogeneous community of cells in a dynamic equilibrium. Extracellular vesicles (EVs) released by microglia mirror the dynamic nature of their donor cells, exerting important and versatile functions in the CNS as unbounded conveyors of bioactive signals. In this review, we summarize the current knowledge on EVs released by microglia, highlighting their heterogeneous properties and multifaceted effects.

Emerging micro-nanotechnologies for extracellular vesicles in immuno-oncology: from target specific isolations to immunomodulation

Extracellular vesicles (EVs) have been hypothesized to incorporate a variety of crucial roles ranging from intercellular communication to tumor pathogenesis to cancer immunotherapy capabilities. Traditional EV isolation and characterization techniques cannot accurately and with specificity isolate subgroups of EVs, such as tumor-derived extracellular vesicles (TEVs) and immune-cell derived EVs, and are plagued with burdensome steps. To address these pivotal issues, multiplex microfluidic EV isolation/characterization and on-chip EV engineering may be imperative towards developing the next-generation EV-based immunotherapeutics. Henceforth, our aim is to expound the state of the art in EV isolation/characterization techniques and their limitations. Additionally, we seek to elucidate current work on total analytical system based technologies for simultaneous isolation and characterization and to summarize the immunogenic capabilities of EV subgroups, both innate and adaptive. In this review, we discuss recent state-of-art microfluidic/micro-nanotechnology based EV screening methods and EV engineering methods towards therapeutic use of EVs in immune-oncology. By venturing in this field of EV screening and immunotherapies, it is envisioned that transition into clinical settings can become less convoluted for clinicians.

Small and long RNA transcriptome of whole human cerebrospinal fluid and serum as compared to their extracellular vesicle fractions reveal profound differences in expression patterns and impacts on biological processes

BACKGROUND

Next generation sequencing (NGS) of human specimen is expected to improve prognosis and diagnosis of human diseases, but its sensitivity urges for well-defined sampling and standardized protocols in order to avoid error-prone conclusions.

METHODS

In this study, large volumes of pooled human cerebrospinal fluid (CSF) were used to prepare RNA from human CSF-derived extracellular vesicles (EV) and from whole CSF, as well as from whole human serum and serum-derived EV. In all four fractions small and long coding and non-coding RNA expression was analyzed with NGS and transcriptome analyses.

RESULTS

We show, that the source of sampling has a large impact on the acquired NGS pattern, and differences between small RNA fractions are more distinct than differences between long RNA fractions. The highest percentual discrepancy between small RNA fractions and the second highest difference between long RNA fractions is seen in the comparison of CSF-derived EV and whole CSF. Differences between miR (microRNA) and mRNA fractions of EV and the respective whole body fluid have the potential to affect different cellular and biological processes. I.e. a comparison of miR in both CSF fractions reveals that miR from EV target four transcripts sets involved in neurobiological processes, whereas eight others, also involved in neurobiological processes are targeted by miR found in whole CSF only. Likewise, three mRNAs sets derived from CSF-derived EV are associated with neurobiological and six sets with mitochondrial metabolism, whereas no such mRNA transcript sets are found in the whole CSF fraction. We show that trace amounts of blood-derived contaminations of CSF can bias RNA-based CSF diagnostics.

CONCLUSIONS

This study shows that the composition of small and long RNA differ significantly between whole body fluid and its respective EV fraction and thus can affect different cellular and molecular functions. Trace amounts of blood-derived contaminations of CSF can bias CSF analysis. This has to be considered for a meaningful RNA-based diagnostics. Our data imply a transport of EV from serum to CSF across the blood-brain barrier.

Role of exosomes in bone and joint disease metabolism, diagnosis, and therapy

Bone and joint diseases are prevalent and often fatal conditions in elderly individuals. Additionally, bone-derived cells may release exosomes that package and distribute a range of active substances, such as proteins, miRNAs, and numerous active factors, thereby facilitating material and information interchange between cells. Exososmes generated from bone may be utilized to manage bone production and resorption balance or even as biological or gene therapy carriers, depending on their properties and composition. In this review, we will discuss the composition, secretion, and uptake theory of exososmes, the role of exososmes in bone metabolism regulation, the pathogenesis and diagnosis of bone and joint diseases, and the application of exososmes in regenerative medicine. The findings will expand our understanding of the potential research and application space regarding exososmes.

Comprehensive Analysis of Serum Small Extracellular Vesicles-Derived Coding and Non-Coding RNAs from Retinoblastoma Patients for Identifying Regulatory Interactions

The present study employed nanoparticle tracking analysis, transmission electron microscopy, immunoblotting, RNA sequencing, and quantitative real-time PCR validation to characterize serum-derived small extracellular vesicles (sEVs) from RB patients and age-matched controls. Bioinformatics methods were used to analyze functions, and regulatory interactions between coding and non-coding (nc) sEVs RNAs. The results revealed that the isolated sEVs are round-shaped with a size < 150 nm, 5.3 × 1011 ± 8.1 particles/mL, and zeta potential of 11.1 to −15.8 mV, and expressed exosome markers CD9, CD81, and TSG101. A total of 6514 differentially expressed (DE) mRNAs, 123 DE miRNAs, and 3634 DE lncRNAs were detected. Both miRNA-mRNA and lncRNA-miRNA-mRNA network analysis revealed that the cell cycle-specific genes including CDKNI1A, CCND1, c-MYC, and HIF1A are regulated by hub ncRNAs MALAT1, AFAP1-AS1, miR145, 101, and 16-5p. Protein-protein interaction network analysis showed that eye-related DE mRNAs are involved in rod cell differentiation, cone cell development, and retinol metabolism. In conclusion, our study provides a comprehensive overview of the RB sEV RNAs and regulatory interactions between them.

Differential microRNA profiles of intramuscular and secreted extracellular vesicles in human tissue-engineered muscle

Exercise affects the expression of microRNAs (miR/s) and muscle-derived extracellular vesicles (EVs). To evaluate sarcoplasmic and secreted miR expression in human skeletal muscle in response to exercise-mimetic contractile activity, we utilized a three-dimensional tissue-engineered model of human skeletal muscle ("myobundles"). Myobundles were subjected to three culture conditions: no electrical stimulation (CTL), chronic low frequency stimulation (CLFS), or intermittent high frequency stimulation (IHFS) for 7 days. RNA was isolated from myobundles and from extracellular vesicles (EVs) secreted by myobundles into culture media; miR abundance was analyzed by miRNA-sequencing. We used edgeR and a within-sample design to evaluate differential miR expression and Pearson correlation to evaluate correlations between myobundle and EV populations within treatments with statistical significance set at p < 0.05. Numerous miRs were differentially expressed between myobundles and EVs; 116 miRs were differentially expressed within CTL, 3 within CLFS, and 2 within IHFS. Additionally, 25 miRs were significantly correlated (18 in CTL, 5 in CLFS, 2 in IHFS) between myobundles and EVs. Electrical stimulation resulted in differential expression of 8 miRs in myobundles and only 1 miR in EVs. Several KEGG pathways, known to play a role in regulation of skeletal muscle, were enriched, with differentially overrepresented miRs between myobundle and EV populations identified using miEAA. Together, these results demonstrate that in vitro exercise-mimetic contractile activity of human engineered muscle affects both their expression of miRs and number of secreted EVs. These results also identify novel miRs of interest for future studies of the role of exercise in organ-organ interactions in vivo.

Osteoimmunomodulation role of exosomes derived from immune cells on osseointegration

Despite the high success rate of biomedical implants adopted clinically, implant failures caused by aseptic loosening still raise the risk of secondary surgery and a substantial economic burden to patients. Improving the stable combination between the implant and the host bone tissue, achieving fast and high-quality osseointegration can effectively reduce the probability of aseptic loosening. Accumulating studies have shown that the osteoimmunomodulation mediated by immune cells mainly dominated by macrophages plays a pivotal role in osseointegration by releasing active factors to improve the inflammatory microenvironment. However, the mechanism by which osteoimmunomodulation mediates osseointegration remains unclear. Recent studies have revealed that exosomes released by macrophages play a central role in mediating osteoimmunomodulation. The exosomes can be internalized by various cells participating in de novo bone formation, such as endothelial cells and osteoblasts, to intervene in the osseointegration robustly. Therefore, macrophage-derived exosomes with multifunctionality are expected to significantly improve the osseointegration microenvironment, which is promising in reducing the occurrence of aseptic loosening. Based on this, this review summarizes recent studies on the effects of exosomes derived from the immune cells on osseointegration, aiming to provide a theoretical foundation for improving the clinical success rate of biomedical implants and achieving high-quality and high-efficiency osseointegration.

Breast Cancer-Delivered Exosomal miRNA as Liquid Biopsy Biomarkers for Metastasis Prediction: A Focus on Translational Research with Clinical Applicability

Metastasis represents the most important cause of breast cancer-associated mortality. Even for early diagnosed stages, the risk of metastasis is significantly high and predicts a grim outcome for the patient. Nowadays, efforts are made for identifying blood-based biomarkers that could reliably distinguish patients with highly metastatic cancers in order to ensure a closer follow-up and a more personalized therapeutic method. Exosomes are nano vesicles secreted by cancer cells that can transport miRNAs, proteins, and other molecules and deliver them to recipient cells all over the body. Through this transfer, cancer cells modulate their microenvironment and facilitate the formation of the pre-metastatic niche, leading to sustained progression. Exosomal miRNAs have been extensively studied due to their promising potential as prognosis biomarkers for metastatic breast cancer. In this review, we tried to depict an overview of the existing literature regarding exosomal miRNAs that are already validated as potential biomarkers, and which could be immediately available for the clinic. Moreover, in the last section, we highlighted several miRNAs that have proven their function in preclinical studies and could be considered for clinical validation. Considering the lack of standard methods for evaluating exosomal miRNA, we also discussed the challenges and the technical aspects underlying this issue.

Magnetic bead-based adsorption strategy for exosome isolation

Exosomes, one type of extracellular vesicle (EV) secreted by cells, participate in intercellular communication and other biological processes as carriers of lipids, functional proteins, mRNAs, miRNAs, lncRNAs, and DNA fragments. Their presence in biofluids makes them attractive candidates as innovative clinical diagnostic tools. However, the conventional isolation and analysis of high-purity exosomes in clinical application is challenging, with traditional methods facing a number of shortcomings, including low yield or purity, long periods of processing, high cost, and difficulties in standardization. In this study, we provide an overview of commonly used exosome isolation approaches with a focus on magnetic bead-based capture, an ideal methodology with high purity and integrality of exosomes. The current challenges on exosome isolation methods are also described to highlight areas for future research and development.

Diagnostic value of exosomes in patients with liver cancer: a systematic review

BACKGROUND

Liver cancer is a disease with high morbidity and mortality. More and more studies have shown that exosomes can be used as biomarkers for the diagnosis of liver cancer, but their diagnostic accuracy is still unclear. Therefore, this meta-analysis summarizes various studies on the diagnostic value of exosomes for liver cancer.

METHODS

A comprehensive search was carried out based on the set search terms in PubMed, Web of Science and Wiley until April 1, 2022. All statistical analyses were performed by STATA 17 statistical software and Review Manager 5.4. Quality Assessment for Studies of Diagnostic Accuracy 2 tool was applied to evaluate the quality of included articles. Random effects model was used to calculate various diagnostic indicators.

RESULTS

A total of 47 studies were included in this meta-analysis. The number of participants was 3196. The combined sensitivity, specificity and the area under the curve with 95% confidence intervals (95% CI) were, respectively 0.80 (0.75-0.84), 0.83 (0.79-0.87), 0.89 (0.85-0.91).

CONCLUSIONS

This meta-analysis shows that exosomes have good diagnostic accuracy for liver cancer and can be used as an effective biomarker for the diagnosis of liver cancer.

Mesenchymal Stem Cell-Derived Secretome: A Potential Therapeutic Option for Autoimmune and Immune-Mediated Inflammatory Diseases

Immune-mediated inflammatory diseases (IMIDs) encompass several entities such as "classic" autoimmune disorders or immune-mediated diseases with autoinflammatory characteristics. Adult stem cells including mesenchymal stem cells (MSCs) are by far the most commonly used type in clinical practice. However, due to the possible side effects of MSC-based treatments, there is an increase in interest in the MSC-secretome (containing large extracellular vesicles, microvesicles, and exosomes) as an alternative therapeutic option in IMIDs. A wide spectrum of MSC-secretome-related biological activities has been proven thus far including anti-inflammatory, anti-apoptotic, and immunomodulatory properties. In comparison with MSCs, the secretome is less immunogenic but exerts similar biological actions, so it can be considered as an ideal cell-free therapeutic alternative. Additionally, since the composition of the MSC-secretome can be engineered, for a future perspective, it could also be viewed as part of a potential delivery system within nanomedicine, allowing us to specifically target dysfunctional cells or tissues. Although many encouraging results from pre-clinical studies have recently been obtained that strongly support the application of the MSC-secretome in IMIDs, human studies with MSC-secretome administration are still in their infancy. This article reviews the immunomodulatory effects of the MSC-secretome in IMIDs and provides insight into the interpretation of its beneficial biological actions.

Emerging role of exosomes in cancer progression and tumor microenvironment remodeling

Cancer is one of the leading causes of death worldwide, and the factors responsible for its progression need to be elucidated. Exosomes are structures with an average size of 100 nm that can transport proteins, lipids, and nucleic acids. This review focuses on the role of exosomes in cancer progression and therapy. We discuss how exosomes are able to modulate components of the tumor microenvironment and influence proliferation and migration rates of cancer cells. We also highlight that, depending on their cargo, exosomes can suppress or promote tumor cell progression and can enhance or reduce cancer cell response to radio- and chemo-therapies. In addition, we describe how exosomes can trigger chronic inflammation and lead to immune evasion and tumor progression by focusing on their ability to transfer non-coding RNAs between cells and modulate other molecular signaling pathways such as PTEN and PI3K/Akt in cancer. Subsequently, we discuss the use of exosomes as carriers of anti-tumor agents and genetic tools to control cancer progression. We then discuss the role of tumor-derived exosomes in carcinogenesis. Finally, we devote a section to the study of exosomes as diagnostic and prognostic tools in clinical courses that is important for the treatment of cancer patients. This review provides a comprehensive understanding of the role of exosomes in cancer therapy, focusing on their therapeutic value in cancer progression and remodeling of the tumor microenvironment.

Current Status, Opportunities, and Challenges of Exosomes in Oral Cancer Diagnosis and Treatment

Oral cancer is one of the most common cancers in the world, with more than 300,000 cases diagnosed each year, of which oral squamous cell carcinoma accounts for more than 90%, with a 5-year survival rate of only 40–60%, and poor prognosis. Exploring new strategies for the early diagnosis and treatment of oral cancer is key to improving the survival rate. Exosomes are nanoscale lipid bilayer membrane vesicles that are secreted by almost all cell types. During the development of oral cancer, exosomes can transport their contents (DNA, RNA, proteins, etc) to target cells and promote or inhibit the proliferation, invasion, and metastasis of oral cancer cells by influencing the host immune response, drug-resistant metastasis, and tumour angiogenesis. Therefore, exosomes have great potential and advantages as biomarkers for oral cancer diagnosis, and as drug delivery vehicles or targets for oral cancer therapy. In this review, we first describe the biogenesis, biological functions, and isolation methods of exosomes, followed by their relationship with oral cancer. Here, we focused on the potential of exosomes as oral cancer biomarkers, drug carriers, and therapeutic targets. Finally, we provide an insightful discussion of the opportunities and challenges of exosome application in oral cancer diagnosis and treatment, intending to offer new ideas for the clinical management of oral cancer.

Analysis of Thrombin-Activated Platelet-Derived Exosome (T-aPDE) Potential for Dental Pulp Regeneration: In-Vitro Study

OBJECTIVE

 This study analyzed the potential of various concentrations of the thrombin-activated platelet-derived exosome (T-aPDE) to regenerate the dental pulp by performing an in-vitro analysis of the cell viability, migration activity, and vascular endothelial growth factor A (VEGF-A) expression of human dental pulp stem cells (hDPSCs).

MATERIAL AND METHODS

 The hDPSCs were collected from nine third molar teeth of nine healthy donors and were isolated and cultured using the explant method. They were harvested between the third and fourth passages and starved, after which they were seeded in the following treatments: Dulbecco's Modified Eagle Medium and 10% platelet-rich plasma-thrombin as the control groups, and 0.5, 1, and 5% T-aPDE as the experimental groups. All groups had three biological triplicates (Triplo) and two number of experiments. The T-aPDE was analyzed using transmission electron microscopy testing, particle size analyzer, and CD63 +  and CD81 +  specific immune phenotyping flow cytometry tests for plasma exosomes. The cell viability was evaluated using the colorimetric assay of activity cellular enzymes (MTT assay); the migration activity, using scratch assay; and the VEGF-A expression, using enzyme-linked immunosorbent assay.

RESULTS

 The highest viability absorbance value of hDPSCs after 24, 48, 72 hours of observation was in the 5% T-aPDE group (p<0.05). Whereas, the closest distance result of migratory activation hDPSCs was also in the same group (p<0.05). However the highest VEGF-A expression of hDSPCs was noted in the same group at 72 hours observation (p<0.05).

STATISTICAL ANALYSIS

 The data were analyzed using one-way analysis of variance and the Kruskal-Wallis test. The statistical power was set at p <0.05 CONCLUSION:  The 5% T-aPDE had a higher potential to induce dental pulp regeneration than the other groups.

Theragnostic Applications of Mammal and Plant-Derived Extracellular Vesicles: Latest Findings, Current Technologies, and Prospects

The way cells communicate is not fully understood. However, it is well-known that extracellular vesicles (EVs) are involved. Researchers initially thought that EVs were used by cells to remove cellular waste. It is now clear that EVs function as signaling molecules released by cells to communicate with one another, carrying a cargo representing the mother cell. Furthermore, these EVs can be found in all biological fluids, making them the perfect non-invasive diagnostic tool, as their cargo causes functional changes in the cells upon receiving, unlike synthetic drug carriers. EVs last longer in circulation and instigate minor immune responses, making them the perfect drug carrier. This review sheds light on the latest development in EVs isolation, characterization and, application as therapeutic cargo, novel drug loading techniques, and diagnostic tools. We also address the advancement in plant-derived EVs, their characteristics, and applications; since plant-derived EVs only recently gained focus, we listed the latest findings. Although there is much more to learn about, EV is a wide field of research; what scientists have discovered so far is fascinating. This paper is suitable for those new to the field seeking to understand EVs and those already familiar with it but wanting to review the latest findings.

Extracellular Vesicles: A New Source of Biomarkers in Pediatric Solid Tumors? A Systematic Review

Virtually every cell in the body releases extracellular vesicles (EVs), the contents of which can provide a "fingerprint" of their cellular origin. EVs are present in all bodily fluids and can be obtained using minimally invasive techniques. Thus, EVs can provide a promising source of diagnostic, prognostic, and predictive biomarkers, particularly in the context of cancer. Despite advances using EVs as biomarkers in adult cancers, little is known regarding their use in pediatric cancers. In this review, we provide an overview of published clinical and in vitro studies in order to assess the potential of using EV-derived biomarkers in pediatric solid tumors. We performed a systematic literature search, which yielded studies regarding desmoplastic small round cell tumor, hepatoblastoma, neuroblastoma, osteosarcoma, and rhabdomyosarcoma. We then determined the extent to which the in vivo findings are supported by in vitro data, and vice versa. We also critically evaluated the clinical studies using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) system, and we evaluated the purification and characterization of EVs in both the in vivo and in vitro studies in accordance with MISEV guidelines, yielding EV-TRACK and PedEV scores. We found that several studies identified similar miRNAs in overlapping and distinct tumor entities, indicating the potential for EV-derived biomarkers. However, most studies regarding EV-based biomarkers in pediatric solid tumors lack a standardized system of reporting their EV purification and characterization methods, as well as validation in an independent cohort, which are needed in order to bring EV-based biomarkers to the clinic.

Applications of Extracellular Vesicles in Abdominal Aortic Aneurysm

Abdominal aortic aneurysm (AAA) is a localized expansion of the abdominal aorta which can lead to lethal complication as the rupture of aortic wall. Currently there is still neither competent method to predict the impending rupture of aneurysm, nor effective treatment to arrest the progression of small and asymptomatic aneurysms. Accumulating evidence has confirmed the crucial role of extracellular vesicles (EVs) in the pathological course of AAA, acting as important mediators of intercellular communication. Given the advantages of intrinsic targeting properties, lower toxicity and fair stability, EVs show great potential to serve as biomarkers, therapeutic agents and drug delivery carriers. However, EV therapies still face several major challenges before they can be applied clinically, including off-target effect, low accumulation rate and rapid clearance by mononuclear phagocyte system. In this review, we first illustrate the roles of EV in the pathological process of AAA and evaluate its possible clinical applications. We also identify present challenges for EV applications, highlight different strategies of EV engineering and constructions of EV-like nanoparticles, including EV display technology and membrane hybrid technology. These leading-edge techniques have been recently employed in multiple cardiovascular diseases and their promising application in the field of AAA is discussed.

Differences in Circulating Extracellular Vesicle and Soluble Cytokines in Older Versus Younger Breast Cancer Patients With Distinct Symptom Profiles

Because extracellular vesicle (EV)-associated cytokines, both encapsulated and surface bound, have been associated with symptom severity, and may vary over the lifespan, they may be potential biomarkers to uncover underlying mechanisms of various conditions. This study evaluated the associations of soluble and EV-associated cytokine concentrations with distinct symptom profiles reported by 290 women with breast cancer prior to surgery. Patients were classified into older (≥60 years, n = 93) and younger (< 60 years, n = 197) cohorts within two previously identified distinct symptom severity profiles, that included pain, depressive symptoms, sleep disturbance, and fatigue (i.e., High Fatigue Low Pain and All Low). EVs were extracted using ExoQuick. Cytokine concentrations were determined using Luminex multiplex assay. Mann Whitney U test evaluated the differences in EV and soluble cytokine levels between symptom classes and between and within the older and younger cohorts adjusting for Karnofsky Performance Status (KPS) score, body mass index (BMI), and stage of disease. Partial correlation analyses were run between symptom severity scores and cytokine concentrations. Results of this study suggest that levels of cytokine concentrations differ between EV and soluble fractions. Several EV and soluble pro-inflammatory cytokines had positive associations with depressive symptoms and fatigue within both age cohorts and symptom profiles. In addition, in the older cohort with High Fatigue Low Pain symptom profile, EV GM-CSF concentrations were higher compared to the All Low symptom profile (p < 0.05). Albeit limited by a small sample size, these exploratory analyses provide new information on the association between cytokines and symptom profiles of older and younger cohorts. Of note, unique EV-associated cytokines were found in older patients and in specific symptom classes. These results suggest that EVs may be potential biomarker discovery tools. Understanding the mechanisms that underlie distinct symptom class profiles categorized by age may inform intervention trials and offer precision medicine approaches.

Novel Gold Nanoparticle-Based Quick Small-Exosome Isolation Technique from Serum Sample at a Low Centrifugal Force

Exosomes are cell-secreted vesicles secreted by a majority of cells and, hence, populating most of the biological fluids, namely blood, tears, sweat, swab, urine, breast milk, etc. They vary vastly in size and density and are influenced by age, gender and diseases. The composition of exosomes includes lipids, DNA, proteins, and coding and noncoding RNA. There is a significant interest in selectively isolating small exosomes (≤50 nm) from human serum to investigate their role in different diseases and regeneration. However, current techniques for small exosome isolation/purification are time-consuming and highly instrument-dependent, with limited specificity and recovery. Thus, rapid and efficient methods to isolate them from bio fluids are strongly needed for both basic research and clinical applications. In the present work, we explored the application of a bench-top centrifuge for isolating mostly the small exosomes (≤50 nm). This can be achieved at low g-force by adding additional weight to the exosomes by conjugating them with citrate-capped gold nanoparticles (CGNP). CGNPs were functionalized with polyethylene glycol (PEG) to form PEGylated GNP (PGNP). EDC/SNHS chemistry is used to activate the –COOH group of the PEG to make it suitable for conjugation with antibodies corresponding to exosomal surface proteins. These antibody-conjugated PGNPs were incubated with the serum to form PGNP-exosome complexes which were separated directly by centrifugation at a low g-force of 7000× g. This makes this technique efficient compared to that of standard ultracentrifugation exosome isolation (which uses approximately 100,000× g). Using the technique, the exosome isolation from serum was achieved successfully in less than two hours. The purification of small exosomes, characterized by the presence of CD63, CD9 and CD81, and sized between 20 nm to 50 nm, was confirmed by western blot, dynamic light scattering (DLS), transmission electron microscopy (TEM) and nanoparticle tracking analyser (NTA).

Conventional and Nonconventional Sources of Exosomes-Isolation Methods and Influence on Their Downstream Biomedical Application

Despite extensive study of extracellular vesicles (EVs), specifically exosomes (EXs) as biomarkers, important modulators of physiological or pathological processes, or therapeutic agents, relatively little is known about nonconventional sources of EXs, such as invertebrate or plant EXs, and their uses. Likewise, there is no clear information on the overview of storage conditions and currently used isolation methods, including new ones, such as microfluidics, which fundamentally affect the characterization of EXs and their other biomedical applications. The purpose of this review is to briefly summarize conventional and nonconventional sources of EXs, storage conditions and typical isolation methods, widely used kits and new "smart" technologies with emphasis on the influence of isolation techniques on EX content, protein detection, RNA, mRNA and others. At the same time, attention is paid to a brief overview of the direction of biomedical application of EXs, especially in diagnostics, therapy, senescence and aging and, with regard to the current situation, in issues related to Covid-19.

Quantitative and Multiplex Detection of Extracellular Vesicle-Derived MicroRNA via Rolling Circle Amplification within Encoded Hydrogel Microparticles

Extracellular vesicle-derived microRNA (EV-miRNA) represent a promising cancer biomarker for disease diagnosis and monitoring. However, existing techniques to detect EV-miRNA rely on complex, bias-prone strategies, and preprocessing steps, making absolute quantification highly challenging. This work demonstrates the development and application of a method for quantitative and multiplex detection of EV-miRNA, via rolling circle amplification within encoded hydrogel particles. By a one-pot extracellular vesicle lysis and microRNA capture step, the bias and losses associated with standard RNA extraction techniques is avoided. The system offers a large dynamic range (3 orders of magnitude), ease of multiplexing, and a limit of detection down to 2.3 zmol (46 × 10-18 m), demonstrating its utility in clinical applications based on liquid biopsy tests. Furthermore, orthogonal measurements of EV concentrations coupled with the direct, absolute quantification of miRNA in biological samples results in quantitative measurements of miRNA copy numbers per volume sample, and per extracellular vesicle.

Evaluating the presence of deregulated tumoral onco-microRNAs in serum-derived exosomes of gastric cancer patients as noninvasive diagnostic biomarkers

Introduction: Exosomal microRNAs (miRNAs) are emerging diagnostic biomarkers for different types of cancers. We aim to detect gastric cancer (GC)-specific miRNAs in serum exosomes with diagnostic potential.

Methods: A pair of 43 tumor and tumor-adjacent tissue biopsies obtained from GC patients, also 5 mL peripheral blood (following 12h fasting) were collected from the same patients and healthy controls (HCs). QIAGEN miRCURY LNA miRNA Focus PCR Panel applied to screen differentially expressed onco-miRNAs. The candidate miRNAs with the highest fold changes proceeded for validation by qRT-PCR in individuals.

Results: We identified that exosomal miR-10a-5p, miR-19b-3p, miR-215-5p, and miR-18a-5p were significantly upregulated in GC patient’s exosomes in contrast to HCs exosomes, Roc curve analysis indicated area under the ROC curve (AUC) of 0.801, 0.721, 0.780 and 0.736 respectively. The Roc curve analysis for the combined signature of four exosomal miRNAs indicated AUC of 0.813. Also, Spearman's correlation coefficients indicated that the miRNA expression is highly correlated between tumor and exosome.

Conclusion: Herein, we specifically identified four miRNAs in serum exosomes of GC patients for a diagnostic purpose which are directly associated with tumoral miRNA expression profile.

Comparison of the capillary-channeled polymer (C-CP) fiber spin-down tip approach to traditional methods for the isolation of extracellular vesicles from human urine

Capillary-channeled polymer fiber (C-CP) solid-phase extraction tips have demonstrated the ability to produce clean and concentrated extracellular vesicle (EV) recoveries from human urine samples in the small EV size range (< 200 nm). An organic modifier-assisted hydrophobic interaction chromatography (HIC) approach is applied in the spin-tip method under non-denaturing conditions-preserving the structure and bioactivity of the recovered vesicles. The C-CP tip method can employ either acetonitrile or glycerol as an elution modifier. The EV recoveries from the C-CP tip method (using both of these solvents) were compared to those obtained using the ultracentrifugation (UC) and polymer precipitation (exoEasy and ExoQuick) EV isolation methods for the same human urine specimen. The biophysical and quantitative characteristics of the recovered EVs using the five isolation methods were assessed based on concentration, size distribution, shape, tetraspanin surface marker protein content, and purity. In comparison to the traditionally used UC method and commercially available polymeric precipitation-based isolation kits, the C-CP tip introduces significant benefits with efficient (< 15 min processing of 12 samples here) and low-cost (< $1 per tip) EV isolations, employing sample volumes (10 µL-1 mL) and concentration (up to 4 × 10¹² EVs mL^-1) scales relevant for fundamental and clinical analyses. Recoveries of the target vesicles versus matrix proteins were far superior for the tip method versus the other approaches.

Profiling Blood Serum Extracellular Vesicles in Plaque Psoriasis and Psoriatic Arthritis Patients Reveals Potential Disease Biomarkers

Psoriasis vulgaris (PsV) and psoriatic arthritis (PsA) are inflammatory diseases with unresolved pathophysiological aspects. Extracellular vesicles (EVs) play an important role in intercellular communication. We compared the miRNA contents and surface proteome of the EVs in the blood serum of PsV and PsA patients to healthy controls. Size-exclusion chromatography was used to isolate EVs from the blood serum of 12 PsV patients, 12 PsA patients and 12 healthy control subjects. EV samples were characterized and RNA sequencing was used to identify differentially enriched EV-bound miRNAs. We found 212 differentially enriched EV-bound miRNAs present in both PsV and PsA groups—a total of 13 miRNAs at FDR ≤ 0.05. The predicted target genes of these miRNAs were significantly related to lesser known but potentially disease-relevant pathways. The EV array revealed that PsV patient EV samples were significantly enriched with CD9 EV-marker compared to controls. Analysis of EV-bound miRNAs suggests that signaling via EVs in the blood serum could play a role in the pathophysiological processes of PsV and PsA. EVs may be able to fill the void in clinically applicable diagnostic and prognostic biomarkers for PsV and PsA.

Encapsulating Cas9 into extracellular vesicles by protein myristoylation

CRISPR/Cas9 genome editing is a very promising avenue for the treatment of a variety of genetic diseases. However, it is still very challenging to encapsulate CRISPR/Cas9 machinery for delivery. Protein N-myristoylation is an irreversible co/post-translational modification that results in the covalent attachment of the myristoyl-group to the N-terminus of a target protein. It serves as an anchor for a protein to associate with the cell membrane and determines its intracellular trafficking and activity. Extracellular vesicles (EVs) are secreted vesicles that mediate cell-cell communication. In this study, we demonstrate that myristoylated proteins were preferentially encapsulated into EVs. The octapeptide derived from the leading sequence of the N-terminus of Src kinase was a favourable substrate for N-myristoyltransferase 1, the enzyme that catalyzes myristoylation. The fusion of the octapeptide onto the N-terminus of Cas9 promoted the myristoylation and encapsulation of Cas9 into EVs. Encapsulation of Cas9 and sgRNA-eGFP inside EVs was confirmed using protease digestion assays. Additionally, to increase the transfection potential, VSV-G was introduced into the EVs. The encapsulated Cas9 in EVs accounted for 0.7% of total EV protein. Importantly, the EVs coated with VSV-G encapsulating Cas9/sgRNA-eGFP showed up to 42% eGFP knock out efficiency with limited off-target effects in recipient cells. Our study provides a novel approach to encapsulate CRISPR/Cas9 protein and sgRNA into EVs. This strategy may open an effective avenue to utilize EVs as vehicles to deliver CRISPR/Cas9 for genome-editing-based gene therapy.

Diagnosis of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome With Partial Least Squares Discriminant Analysis: Relevance of Blood Extracellular Vesicles

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), a chronic disease characterized by long-lasting persistent debilitating widespread fatigue and post-exertional malaise, remains diagnosed by clinical criteria. Our group and others have identified differentially expressed miRNA profiles in the blood of patients. However, their diagnostic power individually or in combinations seems limited. A Partial Least Squares-Discriminant Analysis (PLS-DA) model initially based on 817 variables: two demographic, 34 blood analytic, 136 PBMC miRNAs, 639 Extracellular Vesicle (EV) miRNAs, and six EV features, selected an optimal number of five components, and a subset of 32 regressors showing statistically significant discriminant power. The presence of four EV-features (size and z-values of EVs prepared with or without proteinase K treatment) among the 32 regressors, suggested that blood vesicles carry relevant disease information. To further explore the features of ME/CFS EVs, we subjected them to Raman micro-spectroscopic analysis, identifying carotenoid peaks as ME/CFS fingerprints, possibly due to erythrocyte deficiencies. Although PLS-DA analysis showed limited capacity of Raman fingerprints for diagnosis (AUC = 0.7067), Raman data served to refine the number of PBMC miRNAs from our previous model still ensuring a perfect classification of subjects (AUC=1). Further investigations to evaluate model performance in extended cohorts of patients, to identify the precise ME/CFS EV components detected by Raman and to reveal their functional significance in the disease are warranted.

Research progress on the role and mechanism of action of exosomes in autoimmune thyroid disease

Exosomes are widely distributed extracellular vesicles (EVs), which are currently a major research hotspot for researchers based on their wide range of sources, stable membrane structure, low immunogenicity, and containing a variety of biomolecules. A large number of literatures have shown that exosomes and exosome cargoes (especially microRNAs) play an important role in the activation of inflammation, development of tumor, differentiation of cells, regulation of immunity and so on. Studies have found that exosomes can stimulate the immune response of the body and participate in the occurrence and development of various diseases, including autoimmune diseases. Furthermore, the potential of exosomes as therapeutic tools in various diseases has also attracted much attention. Autoimmune thyroid disease (AITD) is one of the most common autoimmune diseases, mainly composed of Graves' disease (GD) and Hashimoto's thyroiditis (HT), which affects the health of many people and has a genetic predisposition, but its pathogenesis is still being explored. Starting from the relevant biological characteristics of exosomes, this review summarizes the current research status of exosomes and the association between exosomes and some diseases, with a focus on the situation of AITD and the potential role of exosomes (including substances in their vesicles) in AITD in combination with the current published literature, aiming to provide new directions for the pathogenesis, diagnosis or therapy of AITD.Supplemental data for this article is available online at.

UNRAVELLING THE COMPLEXITY OF THE EXTRACELLULAR VESICLE LANDSCAPE WITH ADVANCED PROTEOMICS

INTRODUCTION

The field of extracellular vesicles (EVs) is rapidly advancing. This progress is fuelled by the potential applications of these agents as biomarkers and also as an attractive source to encapsulate therapeutics and other agents to target specific cells.

AREAS COVERED

Different types of EVs, including exosomes, and other nanoparticles have been identified in the last years with key regulatory functions in cell-cell communication. However, the techniques used for their purification possess inherent limitations, resulting in heterogeneous preparations contaminated by other EVs subtypes and nano-size structures. It is therefore urgent to deconvolute the molecular constituents present in each type of EVs in order to accurately ascribe their specific functions. In this context, proteomics can profile, not only the lumen proteins and surface markers, but also their post-translational modifications, which will inform on the mechanisms of cargo selection and sorting.

EXPERT OPINION

Mass spectrometry-based proteomics is now a mature technique and has started to deliver new insights in the EV field. Here, we review recent developments in sample preparation, mass spectrometry (MS) and computational analysis and discuss how these technological advances, in conjunction with improved purification protocols, could impact the proteomic characterization of the complex landscape of EVs and other secreted nanoparticles.

Affinity-based isolation of extracellular vesicles by means of single-domain antibodies bound to macroporous methacrylate-based copolymer

Correct elucidation of physiological and pathological processes mediated by extracellular vesicles (EV) is highly dependent on the reliability of the method used for their purification. Currently available chemical/physical protocols for sample fractionation are time-consuming, often scarcely reproducible and their yields are low. Immuno-capture based approaches could represent an effective purification alternative to obtain homogeneous EV samples. An easy-to-operate chromatography system was set-up for the purification of intact EVs based on a single domain (VHH) antibodies-copolymer matrix suitable for biological samples as different as conditioned cell culture medium and human plasma. Methacrylate-based copolymer is a porous solid support, the chemical versatility of which enables its efficient functionalization with VHHs. The combined analyses of morphological features and biomarker (CD9, CD63 and CD81) presence indicated that the recovered EVs were exosomes. The lipoprotein markers APO-A1 and APO-B were both negative in tested samples. This is the first report demonstrating the successful application of spherical porous methacrylate-based copolymer coupled with VHHs for the exosome isolation from biological fluids. This inexpensive immunoaffinity method has the potential to be applied for the isolation of EVs belonging to different morphological and physiological classes.

Comparison of the yield and purity of plasma exosomes extracted by ultracentrifugation, precipitation, and membrane-based approaches

Exosomes were enriched from plasma by ultracentrifugation, precipitation, and membrane-based approaches for yield and purity. Using the four isolation approaches, particles with mode sizes within the expected range (50–200 nm) can be isolated. By protein estimation, polymer precipitation resulted in a maximum yield (5610.59 ± 51.189 µg/mL), followed by membrane affinity (471.57 ± 12.16 µg/mL), ultracentrifugation (440.22 ± 11.71 µg/mL) and filter + ultracentrifugation (235.47 ± 13.27 µg/mL). By total RNA estimation, the yield of polymer precipitation (3.26 ± 0.42 ng/mL) was higher than that of ultracentrifugation (1.52 ± 0.06 ng/mL), filter + ultracentrifugation (1.21 ± 0.25 ng/mL) and membrane affinity (1.44 ± 0.14 ng/mL). The purity of exosomal preparations was determined as the ratio of the particle number to protein and of protein to RNA. According to the ratio of the particle number to protein concentration, the “purity” of the polymer precipitation method was similar to that of the membrane affinity method and higher than that of ultracentrifugation and filter + ultracentrifugation. When the ratio of RNA to protein was used, the “purity” of the polymer precipitation method was lower than that of the membrane affinity method. Differential methods can be employed to enrich specific exosome subpopulations. The steps of the methods affect the particle number, protein content, and even exosomal purity. The best extraction and evaluation methods for exosomes need to be selected in the laboratory according to their experimental needs.

Comparison of Yield, Purity, and Functional Properties of Large-Volume Exosome Isolation Using Ultrafiltration and Polymer-Based Precipitation

BACKGROUND

Mesenchymal stem cell-derived exosomes are known to produce effects similar to those of source cells and therefore represent a new approach in cell-free regenerative medicine. Their potential clinical application demands efficient isolation of stable and functional exosomes from a large volume of biological fluid.

METHODS

Exosomes from adipose-tissue conditioned medium of the same volume were isolated using either (1) ultrafiltration with size exclusion or (2) ExoQuick-TC. The isolated exosomes were characterized by protein concentration, particle size, exosomal marker expression, RNA expression profiles, and roles in dermal fibroblast proliferation and migration.

RESULTS

Both isolation methods produced exosomes within the size range defined for exosomes (50 to 200 nm) and common markers were enriched. Compared to the ExoQuick-TC precipitation method, the ultrafiltration method produced a significantly higher protein yield (p < 0.001) but a lower particle-to-protein ratio (p < 0.05); it also yielded higher RNA contents from the same fat tissue indicated by housekeeping genes, but with overall lower purity. The expression of several mRNAs and miRNAs related to tissue regeneration showed that there was no statistical difference between both methods, except miR-155 and miR-223 (p < 0.05). However, there was no difference in overall fibroblast proliferation and migration between exosomes isolated by these two methods.

CONCLUSIONS

Ultrafiltration with size exclusion demonstrated higher yields, acceptable purity, and comparable biophysical properties and biological functions to the more expensive commercial precipitation method. Therefore, it may conceivably be translated into yield-efficient and cost-effective modalities for therapeutic purposes.

CLINICAL RELEVANCE STATEMENT

Ultrafiltration with size exclusion may be amenable for exosome isolation from large-volume complex fluids such as tissue conditioned media for clinical application in future regenerative medicine.

Therapeutic applications of exosomes in various diseases: A review

Exosomes (30-150 nm in diameter) a subset of extracellular vesicles, secreted by mostly all cells, have been gaining enormous recognition from the last decade. In recent times, several studies have included exosomes to design novel therapeutic applications along with their contribution to diagnostic evaluations and pathophysiological processes. Based on cell origin, they show diverse functions and characteristics. This article is classified into several sections that include exosomes biogenesis, isolation methods, and application as therapeutic tools, commercialized exosome products, clinical trials, benefits, and challenges faced in the progress of exosome-dependent therapeutics. This work aims to give a thorough review of the numerous studies where exosomes act as therapeutic tools in the treatment of various disorders including heart, kidney, liver, and lung illnesses. The clinical trials involving exosomes, their advantages, and hazards, and difficulties involved during storage and large-scale production, applications of nanotechnology in exosome research while applying for therapeutic applications, and future directions are summarized.

Exercise improves angiogenic function of circulating exosomes in type 2 diabetes: Role of exosomal SOD3

Exosomes, key mediators of cell-cell communication, derived from type 2 diabetes mellitus (T2DM) exhibit detrimental effects. Exercise improves endothelial function in part via the secretion of exosomes into circulation. Extracellular superoxide dismutase (SOD3) is a major secretory copper (Cu) antioxidant enzyme that catalyzes the dismutation of O₂^•- to H₂ O₂ whose activity requires the Cu transporter ATP7A. However, the role of SOD3 in exercise-induced angiogenic effects of circulating plasma exosomes on endothelial cells (ECs) in T2DM remains unknown. Here, we show that both SOD3 and ATP7A proteins were present in plasma exosomes in mice, which was significantly increased after two weeks of volunteer wheel exercise. A single bout of exercise in humans also showed a significant increase in SOD3 and ATP7A protein expression in plasma exosomes. Plasma exosomes from T2DM mice significantly reduced angiogenic responses in human ECs or mouse skin wound healing models, which was associated with a decrease in ATP7A, but not SOD3 expression in exosomes. Exercise training in T2DM mice restored the angiogenic effects of T2DM exosomes in ECs by increasing ATP7A in exosomes, which was not observed in exercised T2DM/SOD3^-/- mice. Furthermore, exosomes overexpressing SOD3 significantly enhanced angiogenesis in ECs by increasing local H₂ O₂  levels in a heparin-binding domain-dependent manner as well as restored defective wound healing and angiogenesis in T2DM or SOD3^-/- mice. In conclusion, exercise improves the angiogenic potential of circulating exosomes in T2DM in a SOD3-dependent manner. Exosomal SOD3 may provide an exercise mimetic therapy that supports neovascularization and wound repair in cardiometabolic disease.

Exosomes in the Pathogenesis, Progression, and Treatment of Osteoarthritis

Osteoarthritis (OA) is a prevalent and debilitating age-related joint disease characterized by articular cartilage degeneration, synovial membrane inflammation, osteophyte formation, as well as subchondral bone sclerosis. OA drugs at present are mainly palliative and do not halt or reverse disease progression. Currently, no disease-modifying OA drugs (DMOADs) are available and total joint arthroplasty remains a last resort. Therefore, there is an urgent need for the development of efficacious treatments for OA management. Among all novel pharmaco-therapeutical options, exosome-based therapeutic strategies are highly promising. Exosome cargoes, which include proteins, lipids, cytokines, and various RNA subtypes, are potentially capable of regulating intercellular communications and gene expression in target cells and tissues involved in OA development. With extensive research in recent years, exosomes in OA studies are no longer limited to classic, mesenchymal stem cell (MSC)-derived vesicles. New origins, structures, and functions of exosomes are constantly being discovered and investigated. This review systematically summarizes the non-classic origins, biosynthesis, and extraction of exosomes, describes modification and delivery techniques, explores their role in OA pathogenesis and progression, and discusses their therapeutic potential and hurdles to overcome in OA treatment.

Characterizing Kaempferia parviflora extracellular vesicles, a nanomedicine candidate

Plant-derived extracellular vesicles (EVs) are a promising candidate for nanomedicine delivery due to their bioactive cargos, high biocompatibility to human cells, biodegradability, low cytotoxicity, and potential for large-scale production. However, the research on EVs derived from medicinal plants is very limited. In this study, Kaempferia parviflora extracellular vesicles (KPEVs) were isolated by differential and sucrose density gradient centrifugation, and their size, morphology, and surface charge were characterized using transmission electron microscopy and dynamic light scattering. The biological properties of KPEVs, including their bioactive compound composition, gastric uptake, cytotoxicity, acid tolerance, and storage stability, were also examined. In addition, KPEVs had an average and uniform size of 200–300 nm and a negative surface charge of 14.7 ± 3.61 mV. Moreover, 5,7-dimethoxyflavone, the major bioactive compound of KP, was packaged into KPEVs. Meanwhile, KPEVs were resistant to gastric digestion and stably maintained at −20°C and −80°C for 8 weeks with no freeze-thaw cycle. The lipid hydrolysis during EVs storage at room temperature and 4°C were also demonstrated for the first time. Furthermore, the labeled KPEVs were internalized into adenocarcinoma gastric cells, and the cell viability was reduced in a dose-dependent manner, according to the results of the thiazolyl blue tetrazolium assay. Our study supports the potential application of KPEVs as a vehicle for anticancer or oral drugs.