Exploring the capabilities in the diverse analytical platforms in metabolomics = Explorando las capacidades de distintas herramientas analíticas en estudios de metabolómica / doctoral dissertation presented by Alma Cristina Villaseñor Solis; supervisor Coral Barbas.

• Autores: Alma Cristina Villaseñor Solis
• Directores de la Tesis: Coral Barbas Arribas (dir. tes.)
• Lectura: En la Universidad CEU San Pablo ( España ) en 2014
• Idioma: inglés
• Tribunal Calificador de la Tesis: Alejandro Cifuentes Gallego (presid.), M. Paz Martinez Alcazar (secret.), Antonia García Fernández (voc.), Elaine Holmes (voc.), Mercedes de Frutos Gómez (voc.)
• Materias:
  • Química
    • Química analítica
    • Bioquímica
• Enlaces
  • Tesis en acceso abierto en: Repositorio Institucional CEU
• Resumen

  • Metabolomics is a relatively new discipline of the systems biology. Defined as ¿the unbiased global survey of all metabolites in an organism¿, this discipline surged as the link to characterize the phenotype, based that metabolites were regarded as real biological endpoints of the metabolism. The metabolites and their concentration are the result of the combination of genetic and environmental factors such as diet, age, ethnicity, lifestyle and gut microflora. Hereby when a disease stage is developed metabolic pathways are disrupt generating up/down stream of a set of metabolites. Here metabolomics offers the potential advantage of discover a suite of relevant biomarkers that are simultaneously affected by the disease. Nevertheless the measurement of all metabolites in an organism and even in a sample is far from possible there is no a single analytical strategy that could cover this challenge. Two main reasons arise: first, the quantity of metabolites is very large and second there is a high diversity of metabolites with different physicochemical properties present in a wide range of concentrations. However the simultaneous determination of a high number of metabolites in a sample that could be representative of the physiological stage of an organism is possible. This aim is reached by some analytical platforms, their use in the study of metabolites is based on the strategy followed; target and non-target approaches. Therefore this thesis has been divided in three sections according to these strategies in metabolomics and analytical methodology; i) method development and validation, ii) untargeted metabolomics, and iii) targeted analysis, each of them focused on obtaining different kind of characteristic information. The present doctoral dissertation shows and highlights in an extensive way the contribution, capabilities, and characteristics (advantages and limitations) of diverse analytical techniques in the metabolomics field. This has been done through a group of different applications using different type of biological samples where a distinct analytical technique or by the combination of two were employed. Additionally from the common aspects mentioned in literature, important aspects of each technique beyond were discussed in each chapter, including problems and challenges faced within each specific context. Along with the analytical equipment the aspects involved with each project such as sample and data treatment, multivariate and pathway analysis, and biochemical explanation were integrated as a part of this study. As an outline this thesis is organized as follows; Chapter 1 shows an introduction with all the aspects related to the field of metabolomics and the description of the workflow stages. The first section related to method development and validation section exhibits the characteristics of gas chromatography ¿ mass spectrometry (GC ¿ MS) along to liquid chromatography ¿ mass spectrometry (LC ¿ MS) in the fulfil of this purpose (Chapter 2). The second section contains the applications of untargeted metabolomics; this encompasses three studies focused in the characterization of the metabolic phenotype through the use of different platforms; nuclear magnetic resonance (NMR, Chapter 3), capillary electrophoresis with UV detection (CE ¿ UV) as a complementary technique for NMR (Chapter 4) and liquid chromatography ¿ mass spectrometry (LC ¿ MS, Chapter 5). The third section shows the target analysis application through the use of capillary electrophoresis with laser induced detector (CE ¿ LIF, Chapter 6). Finally Chapter 7 encompasses a discussion about the strengths, boundaries and characteristics of these analytical techniques.