scholarly journals Potential and challenges of specifically isolating extracellular vesicles from heterogeneous populations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Susann Allelein ◽  
Paula Medina-Perez ◽  
Ana Leonor Heitor Lopes ◽  
Sabrina Rau ◽  
Gerd Hause ◽  
...  
Keyword(s):  
Extracellular Vesicles ◽  
Biomarker Discovery ◽  
Gradient Centrifugation ◽  
Size Exclusion ◽  
Liquid Biopsies ◽  
Antibody Microarray ◽  
Bodily Fluids ◽  
Exclusion Chromatography ◽  
Stable Source ◽  
And Function

AbstractExtracellular vesicles (EVs) have attracted interest due to their ability to provide diagnostic information from liquid biopsies. Cells constantly release vesicles divers in size, content and features depending on the biogenesis, origin and function. This heterogeneity adds a layer of complexity when attempting to isolate and characterize EVs resulting in various protocols. Their high abundance in all bodily fluids and their stable source of origin dependent biomarkers make EVs a powerful tool in biomarker discovery and diagnostics. However, applications are limited by the quality of samples definition. Here, we compared frequently used isolation techniques: ultracentrifugation, density gradient centrifugation, ultrafiltration and size exclusion chromatography. Then, we aimed for a tissue-specific isolation of prostate-derived EVs from cell culture supernatants with immunomagnetic beads. Quality and quantity of EVs were confirmed by nanoparticle tracking analysis, western blot and electron microscopy. Additionally, a spotted antibody microarray was developed to characterize EV sub-populations. Current analysis of 16 samples on one microarray for 6 different EV surface markers in triplicate could be easily extended allowing a faster and more economical method to characterize samples.

scholarly journals Size-Exclusion Chromatography as a Technique for the Investigation of Novel Extracellular Vesicles in Cancer

Cancers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3156
Author(s):  
Daniel S. K. Liu ◽  
Flora M. Upton ◽  
Eleanor Rees ◽  
Christopher Limb ◽  
Long R. Jiao ◽  
...  
Keyword(s):  
Systematic Review ◽  
Cancer Cells ◽  
Size Exclusion Chromatography ◽  
Extracellular Vesicles ◽  
Biomarker Discovery ◽  
Extracellular Vesicle ◽  
Size Exclusion ◽  
Isolation Method ◽  
Isolation And Purification ◽  
Exclusion Chromatography

Cancer cells release extracellular vesicles, which are a rich target for biomarker discovery and provide a promising mechanism for liquid biopsy. Size-exclusion chromatography (SEC) is an increasingly popular technique, which has been rediscovered for the purposes of extracellular vesicle (EV) isolation and purification from diverse biofluids. A systematic review was undertaken to identify all papers that described size exclusion as their primary EV isolation method in cancer research. In all, 37 papers were identified and discussed, which showcases the breadth of applications in which EVs can be utilised, from proteomics, to RNA, and through to functionality. A range of different methods are highlighted, with Sepharose-based techniques predominating. EVs isolated using SEC are able to identify cancer cells, highlight active pathways in tumourigenesis, clinically distinguish cohorts, and remain functionally active for further experiments.

scholarly journals Mode of induction of platelet-derived extracellular vesicles is a critical determinant of their phenotype and function

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
P. M. Ferreira ◽  
E. Bozbas ◽  
S. D. Tannetta ◽  
N. Alroqaiba ◽  
R. Zhou ◽  
...  
Keyword(s):  
Extracellular Vesicles ◽  
Size Exclusion ◽  
Biological Functions ◽  
Critical Determinant ◽  
Agonist Stimulation ◽  
Exclusion Chromatography ◽  
Average Size ◽  
And Function ◽  
Free Plasma ◽  
Insight Into

Abstract Platelet-derived extracellular vesicles (PDEVs) are the most abundant amongst all types of EVs in the circulation. However, the mechanisms leading to PDEVs release, their role in coagulation and phenotypic composition are poorly understood. PDEVs from washed platelets were generated using different stimuli and were characterised using nanoparticle tracking analysis. Procoagulant properties were evaluated by fluorescence flow cytometry and calibrated automated thrombography. EVs from plasma were isolated and concentrated using a novel protocol involving a combination of size exclusion chromatography and differential centrifugation, which produces pure and concentrated EVs. Agonist stimulation enhanced PDEV release, but did not alter the average size of EVs compared to those produced by unstimulated platelets. Agonist stimulation led to lower negatively-charged phospholipid externalization in PDEVs, which was reflected in the lower procoagulant activity compared to those generated without agonist stimulation. Circulating EVs did not have externalized negatively-charged phospholipids. None of the 4 types of EVs presented tissue factor. The mechanism by which PDEV formation is induced is a critical determinant of its phenotype and function. Importantly, we have developed methods to obtain clean, concentrated and functional EVs derived from platelet-free plasma and washed platelets, which can be used to provide novel insight into their biological functions.

scholarly journals The Separation and Characterization of Extracellular Vesicles from Medium Conditioned by Bovine Embryos

2020 ◽  
Vol 21 (8) ◽  
pp. 2942 ◽  
Author(s):  
Krishna Chaitanya Pavani ◽  
Xiaoyuan Lin ◽  
Joachim Hamacher ◽  
Wim Van Den Broeck ◽  
Liesbeth Couck ◽  
...  
Keyword(s):  
Conditioned Medium ◽  
Density Gradient ◽  
Extracellular Vesicles ◽  
Gradient Centrifugation ◽  
High Specificity ◽  
Size Exclusion ◽  
Bovine Embryo ◽  
Characterization Methods ◽  
Ribonucleoprotein Complexes ◽  
Exclusion Chromatography

Extracellular vesicles (EVs) have been identified as one of the communication mechanisms amongst embryos. They are secreted into the embryo culture medium and, as such, represent a source of novel biomarkers for identifying the quality of cells and embryos. However, only small amounts of embryo-conditioned medium are available, which represents a challenge for EV enrichment. Our aim is to assess the suitability of different EV separation methods to retrieve EVs with high specificity and sufficient efficiency. Bovine embryo-conditioned medium was subjected to differential ultracentrifugation (DU), OptiPrepTM density gradient (ODG) centrifugation, and size exclusion chromatography. Separated EVs were characterized by complementary characterization methods, including Western blot, electron microscopy, and nanoparticle tracking analysis, to assess the efficiency and specificity. OptiPrepTM density gradient centrifugation outperformed DU and SEC in terms of specificity by substantial removal of contaminating proteins such as ribonucleoprotein complexes (Argonaute-2 (AGO-2)) and lipoproteins (ApoA-I) from bovine embryo-derived EVs (density: 1.02–1.04, 1.20–1.23 g/mL, respectively). In conclusion, ODG centrifugation is the preferred method for identifying EV-enriched components and for improving our understanding of EV function in embryo quality and development.

scholarly journals Kinetics and Topology of DNA Associated with Circulating Extracellular Vesicles Released during Exercise

Genes ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 522
Author(s):  
Elmo W. I. Neuberger ◽  
Barlo Hillen ◽  
Katharina Mayr ◽  
Perikles Simon ◽  
Eva-Maria Krämer-Albers ◽  
...  
Keyword(s):  
Extracellular Vesicles ◽  
Size Exclusion ◽  
Affinity Capture ◽  
Healthy Humans ◽  
Dnase Digestion ◽  
And Topology ◽  
Single Bout ◽  
Exclusion Chromatography ◽  
Free Circulating Dna ◽  
Line Elements

Although it is widely accepted that cancer-derived extracellular vesicles (EVs) carry DNA cargo, the association of cell-free circulating DNA (cfDNA) and EVs in plasma of healthy humans remains elusive. Using a physiological exercise model, where EVs and cfDNA are synchronously released, we aimed to characterize the kinetics and localization of DNA associated with EVs. EVs were separated from human plasma using size exclusion chromatography or immuno-affinity capture for CD9+, CD63+, and CD81+ EVs. DNA was quantified with an ultra-sensitive qPCR assay targeting repetitive LINE elements, with or without DNase digestion. This model shows that a minute part of circulating cell-free DNA is associated with EVs. During rest and following exercise, only 0.12% of the total cfDNA occurs in association with CD9+/CD63+/CD81+EVs. DNase digestion experiments indicate that the largest part of EV associated DNA is sensitive to DNase digestion and only ~20% are protected within the lumen of the separated EVs. A single bout of running or cycling exercise increases the levels of EVs, cfDNA, and EV-associated DNA. While EV surface DNA is increasing, DNAse-resistant DNA remains at resting levels, indicating that EVs released during exercise (ExerVs) do not contain DNA. Consequently, DNA is largely associated with the outer surface of circulating EVs. ExerVs recruit cfDNA to their corona, but do not carry DNA in their lumen.

Microfluidic Size Exclusion Chromatography (μSEC) for Extracellular Vesicles and Plasma Protein Separation

Small ◽  
2022 ◽  
pp. 2104470
Author(s):  
Sheng Yuan Leong ◽  
Hong Boon Ong ◽  
Hui Min Tay ◽  
Fang Kong ◽  
Megha Upadya ◽  
...  
Keyword(s):  
Size Exclusion Chromatography ◽  
Extracellular Vesicles ◽  
Plasma Protein ◽  
Protein Separation ◽  
Size Exclusion ◽  
Exclusion Chromatography

scholarly journals Analysis of Cerebrospinal Fluid Extracellular Vesicles by Proximity Extension Assay: A Comparative Study of Four Isolation Kits

2020 ◽  
Vol 21 (24) ◽  
pp. 9425
Author(s):  
Sebastian Sjoqvist ◽  
Kentaro Otake ◽  
Yoshihiko Hirozane
Keyword(s):  
Cerebrospinal Fluid ◽  
Extracellular Vesicles ◽  
Proteomic Analysis ◽  
Magnetic Beads ◽  
Biomarker Discovery ◽  
De Novo ◽  
Size Exclusion ◽  
Cell Regulation ◽  
Promising Source ◽  
Proximity Extension Assay

There is a lack of reliable biomarkers for disorders of the central nervous system (CNS), and diagnostics still heavily rely on symptoms that are both subjective and difficult to quantify. The cerebrospinal fluid (CSF) is a promising source of biomarkers due to its close connection to the CNS. Extracellular vesicles are actively secreted by cells, and proteomic analysis of CSF extracellular vesicles (EVs) and their molecular composition likely reflects changes in the CNS to a higher extent compared with total CSF, especially in the case of neuroinflammation, which could increase blood–brain barrier permeability and cause an influx of plasma proteins into the CSF. We used proximity extension assay for proteomic analysis due to its high sensitivity. We believe that this methodology could be useful for de novo biomarker discovery for several CNS diseases. We compared four commercially available kits for EV isolation: MagCapture and ExoIntact (based on magnetic beads), EVSecond L70 (size-exclusion chromatography), and exoEasy (membrane affinity). The isolated EVs were characterized by nanoparticle tracking analysis, ELISA (CD63, CD81 and albumin), and proximity extension assay (PEA) using two different panels, each consisting of 92 markers. The exoEasy samples did not pass the built-in quality controls and were excluded from downstream analysis. The number of detectable proteins in the ExoIntact samples was considerably higher (~150% for the cardiovascular III panel and ~320% for the cell regulation panel) compared with other groups. ExoIntact also showed the highest intersample correlation with an average Pearson’s correlation coefficient of 0.991 compared with 0.985 and 0.927 for MagCapture and EVSecond, respectively. The median coefficient of variation was 5%, 8%, and 22% for ExoIntact, MagCapture, and EVSecond, respectively. Comparing total CSF and ExoIntact samples revealed 70 differentially expressed proteins in the cardiovascular III panel and 17 in the cell regulation panel. To our knowledge, this is the first time that CSF EVs were analyzed by PEA. In conclusion, analysis of CSF EVs by PEA is feasible, and different isolation kits give distinct results, with ExoIntact showing the highest number of identified proteins with the lowest variability.

scholarly journals Enrichment of plasma extracellular vesicles for reliable quantification of their size and concentration for biomarker discovery

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Marija Holcar ◽  
Jana Ferdin ◽  
Simona Sitar ◽  
Magda Tušek-Žnidarič ◽  
Vita Dolžan ◽  
...  
Keyword(s):  
Biomarker Discovery ◽  
Plasma Source ◽  
Extracellular Vesicle ◽  
Size Exclusion ◽  
Enzyme Linked Immunosorbent Assay ◽  
Enrichment Method ◽  
Transmission Electron ◽  
Relative Standard ◽  
Exclusion Chromatography ◽  
Reliable Quantification

AbstractHuman plasma is a complex fluid, increasingly used for extracellular vesicle (EV) biomarker studies. Our aim was to find a simple EV-enrichment method for reliable quantification of EVs in plasma to be used as biomarker of disease. Plasma of ten healthy subjects was processed using sedimentation rate- (sucrose cushion ultracentrifugation—sUC) and size- (size exclusion chromatography—SEC) based methods. According to nanoparticle tracking analysis (NTA), asymmetrical flow field-flow fractionation coupled to detectors (AF4-UV-MALS), miRNA quantification, transmission electron microscopy and enzyme-linked immunosorbent assay, enrichment of EVs from plasma with sUC method lead to high purity of EVs in the samples. High nanoparticle concentrations after SEC resulted from substantial contamination with lipoproteins and other aggregates of EV-like sizes that importantly affect downstream EV quantification. Additionally, sUC EV-enrichment method linked to quantification with NTA or AF4-UV-MALS is repeatable, as the relative standard deviation of EV size measured in independently processed samples from the same plasma source was 5.4% and 2.1% when analyzed by NTA or AF4-UV-MALS, respectively. In conclusion, the sUC EV-enrichment method is compatible with reliable measurement of concentration and size of EVs from plasma and should in the future be tested on larger cohorts in relation to different diseases. This is one of the first studies using AF4-UV-MALS to quantify EVs in blood plasma, which opens new possible clinical utility for the technique.

scholarly journals Molecular cloning and biochemical characterization of rabbit factor XI

2002 ◽  
Vol 367 (1) ◽  
pp. 49-56 ◽  
Author(s):  
Dipali SINHA ◽  
Mariola MARCINKIEWICZ ◽  
David GAILANI ◽  
Peter N. WALSH
Keyword(s):  
Human Factor ◽  
Biochemical Characterization ◽  
Protein A ◽  
Size Exclusion ◽  
Factor Xi ◽  
Sds Page ◽  
Exclusion Chromatography ◽  
Intracellular Process ◽  
And Function

Human factor XI, a plasma glycoprotein required for normal haemostasis, is a homodimer (160kDa) formed by a single interchain disulphide bond linking the Cys-321 of each Apple 4 domain. Bovine, porcine and murine factor XI are also disulphide-linked homodimers. Rabbit factor XI, however, is an 80kDa polypeptide on non-reducing SDS/PAGE, suggesting that rabbit factor XI exists and functions physiologically either as a monomer, as does prekallikrein, a structural homologue to factor XI, or as a non-covalent homodimer. We have investigated the structure and function of rabbit factor XI to gain insight into the relation between homodimeric structure and factor XI function. Characterization of the cDNA sequence of rabbit factor XI and its amino acid translation revealed that in the rabbit protein a His residue replaces the Cys-321 that forms the interchain disulphide linkage in human factor XI, explaining why rabbit factor XI is a monomer in non-reducing SDS/PAGE. On size-exclusion chromatography, however, purified plasma rabbit factor XI, like the human protein and unlike prekallikrein, eluted as a dimer, demonstrating that rabbit factor XI circulates as a non-covalent dimer. In functional assays rabbit factor XI and human factor XI behaved similarly. Both monomeric and dimeric factor XI were detected in extracts of cells expressing rabbit factor XI. We conclude that the failure of rabbit factor XI to form a covalent homodimer due to the replacement of Cys-321 with His does not impair its functional activity because it exists in plasma as a non-covalent homodimer and homodimerization is an intracellular process.

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