Article
Marker peptides in CSF and plasma in experimental cortical contusion injury: Detection and identification using peptidomics
Entdeckung und Identifizierung von Peptidmarkern in Liquor und Plasma im experimentellen Kontusionsmodell unter Verwendung des Peptidomics-Verfahren
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Published: | April 23, 2004 |
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Outline
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Objective
To map changes in peptide pattern in CSF and plasma after controlled cortical impact injury in order to select and identify long-term changed marker peptides.
Methods
We used the PeptidomicsTM technology Differential Peptide DisplayTM to screen CSF and plasma for peptides in rats following controlled cortical impact injury at 1h, 4h, 24h, and 7d after impact. Different statistical parameters and tests (absolute difference, U-test, ROC analysis, Youden’s test) were used to select those signals which had significantly changed after injury versus controls over the whole 7d period. Selected peptides were identified by analysis of their amino acid sequence.
Results
Peptide maps displayed approximately 3600 and 5000 signals in CSF and plasma, respectively. Eight peptides in CSF and 7 in plasma were identified according to the above-named criteria. Sequencing showed that 6 candidates in plasma were fragments of fibrinogen alpha-chain which decreased after trauma. Three of 8 CSF candidates were fibrinopeptide A (FPA) and two FPA modifications truncated by one and two aminoacids. Furthermore, we identified fragments of thymosin-β-4 and thymosin-β-10, ubiquitin, a brain-specific peptide and a secretogranin fragment. Except for the last, all peptides were significantly elevated after trauma.
Conclusions
Peptidomics is a powerful screening technique to display thousands of peptide signals in even very small sample quantities. Furthermore it allows the identification of those marker peptides which are significantly changed in the state of disease under investigation. All peptides we identified after cortical contusion injury have so far not been known to be affected by, or involved in, the cascades of post-traumatic pathophysiology. Further targeted research has to elucidate the role of those peptides in post-traumatic pathophysiology.