title: An integrated workflow for multiplex CSF proteomics and peptidomics-identification of candidate cerebrospinal fluid biomarkers of Alzheimer's disease.
abstract: Many disease processes in the brain are reflected in the protein composition of the cerebrospinal fluid (CSF). In addition to proteins, CSF also contains a large number of endogenous peptides whose potential as disease biomarkers largely remains to be explored. We have developed a novel workflow in which multiplex isobaric labeling is used for simultaneous quantification of endogenous CSF peptides and proteins by liquid chromatography coupled with mass spectrometry. After the labeling of CSF samples, endogenous peptides are separated from proteins by ultrafiltration. The proteins retained on the filters are trypsinized, and the tryptic peptides are collected separately. We evaluated this technique in a comparative pilot study of CSF peptide and protein profiles in eight patients with Alzheimer's disease (AD) and eight nondemented controls. We identified several differences between the AD and control group among endogenous peptides derived from proteins known to be associated with AD, including neurosecretory protein VGF (ratios AD/controls 0.45-0.81), integral membrane protein 2B (ratios AD/controls 0.72-0.84), and metallothionein-3 (ratios AD/controls 0.51-0.61). Analysis of tryptic peptides identified several proteins that were altered in the AD group, some of which have previously been reported as changed in AD, for example, VGF (ratio AD/controls 0.70).
authors.affiliation: Clinical Neurochemistry Laboratory, Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy, University of Gothenburg , 431 80 Mölndal, Sweden.
authors.forename: Mikko
authors.initials: M
authors.lastname: Hölttä
authors.forename: Lennart
authors.initials: L
authors.lastname: Minthon
authors.forename: Oskar
authors.initials: O
authors.lastname: Hansson
authors.forename: Jessica
authors.initials: J
authors.lastname: Holmén-Larsson
authors.forename: Ian
authors.initials: I
authors.lastname: Pike
authors.forename: Malcolm
authors.initials: M
authors.lastname: Ward
authors.forename: Karsten
authors.initials: K
authors.lastname: Kuhn
authors.forename: Ulla
authors.initials: U
authors.lastname: Rüetschi
authors.forename: Henrik
authors.initials: H
authors.lastname: Zetterberg
authors.forename: Kaj
authors.initials: K
authors.lastname: Blennow
authors.forename: Johan
authors.initials: J
authors.lastname: Gobom
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000134:cerebrospinal fluid*; D015415:Biomarkers / Q000134:cerebrospinal fluid*; D002556:Cerebrospinal Fluid Proteins / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010455:Peptides / Q000134:cerebrospinal fluid*; D040901:Proteomics; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D015415:Biomarkers; D002556:Cerebrospinal Fluid Proteins; D010455:Peptides
keywords: Alzheimer’s disease; biomarker discovery; cerebrospinal fluid; clinical proteomics; isobaric labeling; neurodegenerative disease; peptidomics; proteomics; quantification