Focused metabolic profiling of methylarginines and related biological amines

8^th International Conference and Exhibition on Metabolomics & Systems Biology

May 08-10, 2017 Singapore

Blerina Ahmetaj-Shala, Abel Tesfai, Esther Ajayi, Nicholas S Kirkby, Jane A Mitchell and Elizabeth Want

Imperial College London, UK

Posters & Accepted Abstracts: Metabolomics

Abstract :

Introduction: As our understanding of broad metabonomic analysis applied to human health and disease increases, there is an opportunity to utilize targeted metabonomics in order to identify biomarkers and uncover mechanisms of disease and drug toxicity. Of particular importance to diseases like cancer, cardiovascular disease and sepsis, are the metabolic pathways that encompass the biological network that links nitric oxide (NO) with amines, particularly the substrate for NO, L-arginine and the substrate-inhibitor asymmetric dimethylarginine (ADMA). In order to understand how L-arginine and ADMA function in health and disease, we need to be able to measure them efficiently, and there are several problems with this. Firstly NO, L-arginine and ADMA are difficult to measure in biological fluids. Secondly because of the opposing effects of arginine and methylarginines on NO release, it is important to measure both simultaneously. Finally, because the levels of arginine are regulated by other amino acids, particularly citrulline, glutamine and ornithine, it is important to consider a targeted array that includes these. Thus, using a â��focused metabolic profilingâ�� approach, we aimed to develop a novel technique which measures L-arginine, methylarginines and a wide array of biological amines in one simple assay. Methodology & Results: Ultra performance Liquid Chromatography-Mass Spectrometry (UPLC-MS) was used to measure L-arginine and the methylarginines ADMA, monomethyl-L-arginine (L-NMMA) and symmetric dimethylarginine (SDMA) alongside over 30 other amines (Figure-1). Protein was removed from human or mouse samples (10 �¼l) using methanol. Samples were derivatised to improve resolution and mass spectrometric detection. MRM transitions were optimized through the infusion of standard compounds. MS analysis was performed using a XEVO tandem quadrupole mass spectrometer. Conclusion: The focused metabolic profiling described above is the first world-wide study that provides a unique opportunity to identify novel mechanistic pathways and biomarkers involved in NO-related diseases such as cardiovascular disease.

Biography :

Email: b.ahmetaj@imperial.ac.uk