Nicola Gray (Presenter)
Shimadzu UK
Bio: Nicola is Technical Specialist for LC-MS applications for Shimadzu UK, responsible for the support of Shimadzu's LC-MS products and applications and the development of new LCMS applications and collaborative research projects. Prior to this Nicola worked as a Senior Scientist for Waters Corporation based at Imperial College London. Nicola completed her PhD in Analytical Chemistry at King’s College London. During 2012 she worked as an LC-MS analyst for the Anti-Doping Science Centre, involved in developing and performing LC-MS assays for the London 2012 Olympic Games. Prior to this she obtained a MSc in Forensic Science from King’s College London and a BSc Hons degree in Biomedical Science from the University of Newcastle-upon-Tyne.
Authorship: Nicola Gray(1), Stuart Snowden(2), Min Kim(2), Chris Titman(1), Cristina Legido-Quigley(2)
(1) Shimadzu UK, Milton Keynes, (2) King’s College London, UK
| Short Abstract Here we investigate biochemical changes in metabolic processes in patients with Alzheimer’s disease using a targeted LC-MS/MS method for primary metabolites in human plasma. Human plasma samples from Alzheimer’s patients were compared with healthy age- and sex-matched controls using a targeted LC-MS/MS approach for amino acids, organic acids, nucleotides, nucleosides and co-enzymes. Sample preparation comprised a two-phase extraction with methyl tert-butyl ether (MTBE) and methanol/water with the methanol/water phase analysed directly by LC-MS/MS. Statistical analysis shows differentiation in profiles from disease and control subjects, with significant changes noted in purine metabolism and perturbations in neurotransmitter pathways including serotonin. |
Long Abstract
Introduction
High-throughput and unbiased global profiling metabonomic approaches provide a suitable platform to analyse variations in metabolite levels, offering insights into mechanisms of disease through the discovery of novel biomarkers. Targeted approaches, however, offer a more specific, sensitive and quantitative measure for selected compounds. Here we investigate biochemical changes in enzymatic and metabolic processes at the cellular level in patients with Alzheimer’s disease using a targeted LC-MS/MS method for primary metabolites in human plasma. A method using a pentafluorophenylproyl (PFPP) column enables the comprehensive analysis of 97 hydrophilic and hydrophobic primary metabolites. Using this approach the simultaneous analysis of amino acids, organic acids, nucleotides, nucleosides and co-enzymes was performed on 33 plasma samples from AD patients and 43 age- and sex-matched controls.
Methods
Human plasma samples (20 µL) were prepared using a two-phase extraction with methyl tert-butyl ether (MTBE) and methanol/water. The methanol/water phase was injected directly for LC-MS/MS analysis. Chromatographic separation was performed using a Nexera X2 UHPLC system (Shimadzu Corporation, Japan) with a pentafluorophenylpropyl (PFPP) column coupled to a Shimadzu LCMS-8060 Triple Quadrupole mass spectrometer operated in positive and negative electrospray (ESI) mode using fast polarity switching. Data were processed using LabSolutions (Shimadzu Corporation, Japan) followed by SIMCA P 14.0 (Umetrics, Sweden) and R for further statistical analysis.
Results
Human plasma samples from Alzheimer’s disease patients were investigated and compared with healthy age- and sex-matched controls using a targeted LC-MS/MS approach for the analysis of 97 primary metabolites. Unsupervised multivariate principal components analysis (PCA) showed that plasma metabolite profiles from disease and control subjects separated and pooled QC samples clustered together indicating good analytical reproducibility. Partial lease squares – discriminant analysis (PLS-DA) was performed between disease and control groups to identify analytes responsible for group differentiation and subsequent filtering based on significance highlights potential pathways affected. Univariate statistical analysis shows differentiation in profiles from disease and control subjects, with significant changes noted in purine metabolism, the urea/TCA cycle and perturbations in neurotransmitter transduction including tryptophan and serotonin synthesis.
Conclusions
Here we have shown the comprehensive analysis of primary metabolites in human plasma, which revealed metabolic changes between control and Alzheimer’s disease patients. This targeted approach focused on primary metabolites provides a sensitive and selective way of exploring biochemical changes leading to Alzheimer’s disease, offering insights into the complex events involved in disease progression and potential treatment targets. Reduced plasma tryptophan and serotonin suggest a disturbance in neurotransmission, changes to which may result in reduced signal transduction in Alzheimer’s disease patients.
References & Acknowledgements:
| Description | Y/N | Source |
| Grants | no | |
| Salary | yes | Shimadzu UK Limited |
| Board Member | no | |
| Stock | no | |
| Expenses | no |
IP Royalty: no
| Planning to mention or discuss specific products or technology of the company(ies) listed above: | no |