Beschreibung:
Metabolomics and lipidomics are rapidly evolving fields of research. By improving analytical instrumentation and bioinformatics data evaluation performance, these scientific fields have experienced substantial progress, yet there is an undeniable lack of standardization of pre-analytical aspects including the experimental design and the sample processing stages. These have an important impact on the acquisition of reliable quantitative data, and as such were the main study targets during the development of this thesis. The current work is divided in three major parts. First, an overview of non-enzymatic energy metabolite degradation/interconversion chemistry in metabolomics studies of the central carbon metabolism, and an exploration of the stability of nucleotide triphosphates under common metabolomics experimental conditions are presented. Lipids are a subset of molecules representing 70% of the metabolome. As such, lipidomics is currently considered a separate discipline. Thus, the second part of this work provides an overview of common pitfalls during a typical lipidomics workflow, focusing on extraction as a critical step of the pre-analytical stage for lipid analysis. Here, a comprehensive comparison between two- and single-phase extraction systems for lipid analysis is carried out using untargeted lipidomics. In the last part, translational work showing the diagnostic and prognostic potential of circulating 5-oxoproline as a possible biomarker for patients with heart failure is described. Furthermore, to obtain a better understanding of the involvement of the γ-glutamyl cycle in heart failure, other key components including L-glutamate, reduced and oxidized glutathione (GSH and GSSG) were quantitatively evaluated in a mouse model.