| Title: |
Identification and proteomic profiling of exosomes in human cerebrospinal fluid |
| Authors: |
Street, Jonathan M; Barran, Perdita E; Mackay, C Logan; Weidt, Stefan; Balmforth, Craig; Walsh, Tim S; Chalmers, Rod TA; Webb, David J; Dear, James W |
| Publisher Information: |
BioMed Central Ltd. |
| Publication Year: |
2012 |
| Collection: |
BioMed Central |
| Subject Terms: |
Exosomes; human; CSF; proteomics |
| Description: |
Background Exosomes are released from multiple cell types, contain protein and RNA species, and have been exploited as a novel reservoir for disease biomarker discovery. They can transfer information between cells and may cause pathology, for example, a role for exosomes has been proposed in the pathophysiology of Alzheimer's disease. Although studied in several biofluids, exosomes have not been extensively studied in the cerebrospinal fluid (CSF) from humans. The objective of this study was to determine: 1) whether human CSF contains exosomes and 2) the variability in exosomal protein content across individuals. Methods CSF was collected from 5 study participants undergoing thoraco-abdominal aortic aneurysm repair (around 200 - 500 ml per participant) and low-density membrane vesicles were concentrated by ultracentrifugation. The presence of exosomes was determined by western blot for marker proteins, isopycnic centrifugation on a sucrose step gradient and transmission electron microscopy with immuno-labelling. Whole protein profiling was performed using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR). Results Flotillin 1 and tumor susceptibility gene 101 (TSG101), two exosomal marker proteins, were identified in the ultracentrifugation pellet using western blot. These markers localized to a density consistent with exosomes following isopycnic centrifugation. Transmission electron microscopy visualized structures consistent with exosomes in size and appearance that labelled positive for flotillin 1. Therefore, the pellet that resulted from ultracentrifugation of human CSF contained exosomes. FT-ICR profiling of this pellet was performed and 84-161 ions were detected per study participant. Around one third of these ions were only present in a single study participant and one third were detected in all five. With regard to ion quantity, the median coefficient of variation was 81% for ions detected in two or more samples. Conclusions Exosomes were identified in human CSF and their ... |
| Document Type: |
report |
| Language: |
English |
| Relation: |
http://www.translational-medicine.com/content/10/1/5 |
| Availability: |
http://www.translational-medicine.com/content/10/1/5 |
| Rights: |
Copyright 2012 Street et al; licensee BioMed Central Ltd. |
| Accession Number: |
edsbas.470041FD |
| Database: |
BASE |