Detection of amyloid-beta oligomers in human cerebrospinal fluid by flow cytometry and fluorescence resonance energy transfer.

ACGT ProGenomics AG, Halle, Germany.
Journal of Alzheimer's disease: JAD (Impact Factor: 4.17). 04/2007; 11(1):117-25.
Source: PubMed

ABSTRACT The neuropathology of Alzheimer's disease (AD) has been linked recently to non-fibrillar forms of neurotoxic amyloid-beta (Abeta) oligomers of which high levels are observed in the brain of AD patients. This suggests that Abeta oligomers play a key role in the early events of AD, underlining their potential for the early diagnosis of the disease. We have developed an extremely sensitive assay for the detection of oligomeric and fibrillar structures of Abeta that is based on multiparametric analysis of data obtained by flow cytometry and fluorescence resonance energy transfer (Fret). The assay readily detects Abeta oligomers in human cerebrospinal fluid (CSF) as verified by dot blot of the isolated particles. By measuring 174 CSF samples of non-demented control patients with various neurological disorders a high reliability and reproducibility of the method could be demonstrated.

1 Bookmark
  • [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND: Soluble oligomers of amyloid ß-protein (Aß) have been increasingly linked to synaptic dysfunction, tau alteration, and neuritic dystrophy in Alzheimer's disease (AD) and mouse models. There is a great need for assays that quantify Aß oligomers with high specificity and sensitivity. METHODS: We designed and validated two oligomer-specific (o-) enzyme-linked immunoassays (ELISAs) using either an Aß aggregate-selective monoclonal for capture and a monoclonal to the free N-terminus for detection, or the latter antibody for both capture and detection. RESULTS: The o-ELISAs specifically quantified pure oligomers of synthetic Aß with sizes from dimers up to much larger assemblies and over a wide dynamic range of concentrations, whereas Aß monomers were undetectable. Natural Aß oligomers of similarly wide size and concentration ranges were measured in extracts of AD and control brains, revealing >1000-fold higher concentrations of Aß oligomers than monomers in the soluble fraction of AD cortex. The assays quantified the age-related rise in oligomers in hAPP transgenic mice. Unexpectedly, none of 90 human cerebrospinal fluid (CSF) samples gave a specific signal in either o-ELISA. CONCLUSIONS: These new o-ELISAs with rigorously confirmed specificity can quantify oligomer burden in human and mouse brains for diagnostic and mechanistic studies and for AD biomarker development. However, our data raise the likelihood that the hydrophobicity of Aß oligomers makes them very low in number or absent in aqueous CSF.
    Alzheimer's & dementia: the journal of the Alzheimer's Association 01/2013; · 14.48 Impact Factor
  • Source
  • [Show abstract] [Hide abstract]
    ABSTRACT: The preclinical phase of Alzheimer's disease (AD) occurs years, possibly decades, before the onset of clinical symptoms. Being able to detect the very earliest stages of AD is critical to improving understanding of AD biology, and identifying individuals at greatest risk of developing clinical symptoms with a view to treating AD pathophysiology before irreversible neurodegeneration occurs. Studies of dominantly inherited AD families and longitudinal studies of sporadic AD have contributed to knowledge of the earliest AD biomarkers. Here we appraise this evidence before reviewing novel, particularly fluid, biomarkers that may provide insights into AD pathogenesis and relate these to existing hypothetical disease models.
    Molecular diagnosis & therapy. 11/2013;

Full-text (2 Sources)

Available from
May 27, 2014