Dataset Information

Comparative analysis of discrete exosome fractions obtained by differential centrifugation.

ABSTRACT:

Background

Cells release a mixture of extracellular vesicles, amongst these exosomes, that differ in size, density and composition. The standard isolation method for exosomes is centrifugation of fluid samples, typically at 100,000×g or above. Knowledge of the effect of discrete ultracentrifugation speeds on the purification from different cell types, however, is limited.

Methods

We examined the effect of applying differential centrifugation g-forces ranging from 33,000×g to 200,000×g on exosome yield and purity, using 2 unrelated human cell lines, embryonic kidney HEK293 cells and bladder carcinoma FL3 cells. The fractions were evaluated by nanoparticle tracking analysis (NTA), total protein quantification and immunoblotting for CD81, TSG101, syntenin, VDAC1 and calreticulin.

Results

NTA revealed the lowest background particle count in Dulbecco's Modified Eagle's Medium media devoid of phenol red and cleared by 200,000×g overnight centrifugation. The centrifugation tube fill level impacted the sedimentation efficacy. Comparative analysis by NTA, protein quantification, and detection of exosomal and contamination markers identified differences in vesicle size, concentration and composition of the obtained fractions. In addition, HEK293 and FL3 vesicles displayed marked differences in sedimentation characteristics. Exosomes were pelleted already at 33,000×g, a g-force which also removed most contaminating microsomes. Optimal vesicle-to-protein yield was obtained at 67,000×g for HEK293 cells but 100,000×g for FL3 cells. Relative expression of exosomal markers (TSG101, CD81, syntenin) suggested presence of exosome subpopulations with variable sedimentation characteristics.

Conclusions

Specific g-force/k factor usage during differential centrifugation greatly influences the purity and yield of exosomes. The vesicle sedimentation profile differed between the 2 cell lines.

SUBMITTER: Jeppesen DK

PROVIDER: S-EPMC4224706 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature

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Publications

Comparative analysis of discrete exosome fractions obtained by differential centrifugation.

Jeppesen Dennis K DK Hvam Michael L ML Primdahl-Bengtson Bjarke B Boysen Anders T AT Whitehead Bradley B Dyrskjøt Lars L Orntoft Torben F TF Howard Kenneth A KA Ostenfeld Marie S MS

Journal of extracellular vesicles 20141106

<h4>Background</h4>Cells release a mixture of extracellular vesicles, amongst these exosomes, that differ in size, density and composition. The standard isolation method for exosomes is centrifugation of fluid samples, typically at 100,000×g or above. Knowledge of the effect of discrete ultracentrifugation speeds on the purification from different cell types, however, is limited.<h4>Methods</h4>We examined the effect of applying differential centrifugation g-forces ranging from 33,000×g to 200,0 ...[more]

PMID: 25396408

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Project description:BackgroundDengue is the most widespread mosquito-borne viral disease of public health concern. In some patients, endothelial cell and platelet dysfunction lead to life-threatening hemorrhagic dengue fever or dengue shock syndrome. Prognostication of disease severity is urgently required to improve patient management. The pathogenesis of severe dengue has not been fully elucidated, and the role of host proteins associated with viral particles has received little exploration.MethodsThe proteomes of virion-enriched fractions purified from plasma pools of patients with dengue fever or severe dengue were compared. Virions were purified by ultracentrifugation combined with a water-insoluble polyelectrolyte-based technique. Following in-gel hydrolysis, peptides were analyzed by nano-liquid chromatography coupled to ion trap mass spectrometry and identified using data libraries.ResultsBoth dengue fever and severe dengue viral-enriched fractions contained identifiable viral envelope proteins and host cellular proteins. Canonical pathway analysis revealed the identified host proteins are mainly involved in the coagulation cascade, complement pathway or acute phase response signaling pathway. Some host proteins were over- or under-represented in plasma from patients with severe dengue compared to patients with dengue fever. ELISAs were used to validate differential expression of a selection of identified host proteins in individual plasma samples of patients with dengue fever compared to patients with severe dengue. Among 22 host proteins tested, two could differentiate between dengue fever and severe dengue in two independent cohorts (olfactomedin-4: area under the curve (AUC), 0.958; and platelet factor-4: AUC, 0.836).ConclusionA novel technique of virion-enrichment from plasma has allowed to identify two host proteins that have prognostic value for classifying patients with acute dengue who are more likely to develop a severe dengue. The impact of these host proteins on pathogenicity and disease outcome are discussed.

Dataset Information

Comparative analysis of discrete exosome fractions obtained by differential centrifugation.

Background

Methods

Results

Conclusions

Publications

Comparative analysis of discrete exosome fractions obtained by differential centrifugation.

Similar Datasets

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