scholarly journals A Comparison of Blood Plasma Exosome Enrichment Strategies for Proteomic Analysis

2021 ◽  
Author(s):  
Natalie P. Turner ◽  
Pevindu Abeysinghe ◽  
Keith A. Kwan Cheung ◽  
Kanchan Vaswani ◽  
Jayden Logan ◽  
...  
Keyword(s):  
Blood Plasma ◽  
Proteomic Analysis ◽  
Protein Identification ◽  
Biomarker Discovery ◽  
Bos Taurus ◽  
Size Exclusion ◽  
Gold Standard Method ◽  
Exclusion Chromatography ◽  
Liquid Chromatography Tandem Mass ◽  
Enrichment Methods

Abstract Proteomic analysis of exosomes (EX) poses a significant challenge. A ‘gold-standard’ method for plasma EX enrichment for downstream proteomic analysis is yet to be established. Our group has performed a comprehensive study of multi-dimensional enrichment methods to determine their efficiency for protein isolation. Methods were evaluated for their capacity to a) successfully isolate and enrich EX from blood plasma, b) minimise the presence of highly abundant plasma proteins, and c) result in the optimum representation of EX proteins by liquid chromatography tandem mass spectrometry (LC-MS/MS). Blood plasma from four animals (Bos taurus) of similar physical attributes and genetics were used. Three methods of EX enrichment were utilised: ultracentrifugation (UC), size-exclusion chromatography (SEC), and ultrafiltration (UF). These enrichment methods were combined to create four groups for methodological evaluation: UC+SEC, UC+SEC+UF, SEC+UC and SEC+UF. UC+SEC yielded the highest number of protein IDs. Plasma protein identification was the least in SEC+UC, but this method yielded the lowest number of protein IDs overall. UC+SEC+UF decreased EX protein ID and did not improve purity compared to UC+SEC. Our data suggest that the method and sequence of EX enrichment strategy impacts protein ID, which may influence the outcome of biomarker discovery studies.

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 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 Quantitative proteomic analysis of extracellular vesicle subgroups isolated by an optimized method combining polymer‐based precipitation and size exclusion chromatography

2021 ◽  
Vol 10 (6) ◽  
Author(s):  
Juan A. Martínez‐Greene ◽  
Karina Hernández‐Ortega ◽  
Ricardo Quiroz‐Baez ◽  
Osbaldo Resendis‐Antonio ◽  
Israel Pichardo‐Casas ◽  
...  
Keyword(s):  
Size Exclusion Chromatography ◽  
Proteomic Analysis ◽  
Extracellular Vesicle ◽  
Size Exclusion ◽  
Quantitative Proteomic Analysis ◽  
Exclusion Chromatography

scholarly journals NACK and INTEGRATOR act coordinately to activate Notch-mediated transcription in tumorigenesis

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Elena Shersher ◽  
Mohini Lahiry ◽  
Annamil Alvarez-Trotta ◽  
Giulia Diluvio ◽  
David J. Robbins ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Rna Polymerase Ii ◽  
Transcriptional Activation ◽  
Target Genes ◽  
Quantitative Polymerase Chain Reaction ◽  
Size Exclusion ◽  
M Cell ◽  
Exclusion Chromatography ◽  
Liquid Chromatography Tandem Mass ◽  
Eac Cells

Abstract Background Notch signaling drives many aspects of neoplastic phenotype. Here, we report that the Integrator complex (INT) is a new component of the Notch transcriptional supercomplex. Together with Notch Activation Complex Kinase (NACK), INT activates Notch1 target genes by driving RNA polymerase II (RNAPII)-dependent transcription, leading to tumorigenesis. Methods Size exclusion chromatography and CBF-1/RBPJ/Suppressor of Hairless/Lag-1 (CSL)-DNA affinity fast protein liquid chromatography (FPLC) was used to purify Notch/CSL-dependent complexes for liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Chromatin immunoprecipitation (ChIP) and quantitative polymerase chain reaction (qPCR) were performed to investigate transcriptional regulation of Notch target genes. Transfection of Notch Ternary Complex components into HEK293T cells was used as a recapitulation assay to study Notch-mediated transcriptional mechanisms. Gene knockdown was achieved via RNA interference and the effects of protein depletion on esophageal adenocarcinoma (EAC) proliferation were determined via a colony formation assay and murine xenografts. Western blotting was used to examine expression of INT subunits in EAC cells and evaluate apoptotic proteins upon INT subunit 11 knockdown (INTS11 KD). Gene KD effects were further explored via flow cytometry. Results We identified the INT complex as part of the Notch transcriptional supercomplex. INT, together with NACK, activates Notch-mediated transcription. While NACK is required for the recruitment of RNAPII to a Notch-dependent promoter, the INT complex is essential for RNAPII phosphorylated at serine 5 (RNAPII-S5P), leading to transcriptional activation. Furthermore, INT subunits are overexpressed in EAC cells and INTS11 KD results in G2/M cell cycle arrest, apoptosis, and cell growth arrest in EAC. Conclusions This study identifies the INT complex as a novel co-factor in Notch-mediated transcription that together with NACK activates Notch target genes and leads to cancer cell proliferation.

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