The Effects of β-Amyloid on the Metabolome of SH-SY5Y Cells as a Model for the First Steps in Alzheimer's Disease

UoM administered thesis: Phd

  • Authors:
  • Roksana Dawson

Abstract

Alzheimer’s disease is the most common form of senile dementia characterized pathologically by abnormally high levels of senile plaques composed of a 39-43 amino acid peptide known as β-Amyloid (Aβ). The key event for the onset of Alzheimer’s is the aggregation of Aβ, resulting in a series of events which ultimately causes cell death. The mechanisms of toxicity of Aβ are not fully understood, however it is thought to include membrane dysfunction/permeabalization, oxidative stress, mitochondria dysfunction etc. Within this study human neuroblastoma cells known as SH-SY5Y were used to study the effects of Aβ42 in relation to metabolome of cells. Metabolomics is a field which combines strategies to attempt to identify and quantify all metabolites present intra-cellularly and extra-cellularly at a particular time and in a particular environment. Fourier transform infrared (FT-IR) spectroscopy was used in order to assess the phenotypic response of cells exposed to Aβ42 peptide. This was used directly on cells (the metabolic fingerprint) and on the cell growth medium (the metabolic footprint). Gas chromatography - mass spectrometry and liquid chromatography – mass spectrometry were next used for metabolite profiling and identification. Multivariate and univariate analysis of data was carried out which showed phenotypic difference between control cells and cells exposed to Aβ42. Results from FT-IR spectroscopy based analysis suggested specific metabolite changes within lipid, carbohydrate and nucleotide areas indicating that Aβ could be causing damage to lipid structures as well as decreasing overall cell viability and numbers. Cells exposed to Aβ42 also showed a more homogenous phenotype indicating that these cells could all have been arrested in one particular phase of the cell division cycle. Mass spectrometry results revealed poor separation of healthy and diseased samples based on multivariate analysis alone. Univariate analysis revealed up regulation of glutathione S-transferase P, adenosylmethionine decarboxylase and catechol O-methyltransferase by cells which could have been protective responses by the SH-SY5Y cells upon exposure to Aβ42. Data suggested that a lipidomics approach would be useful and could possibly provide greater insight into metabolite changes in cells when exposed to Aβ42.

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Original languageEnglish
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Award date1 Aug 2019