Lipidomics of Biological Samples for the Assessment of Physiological and Pathological Processes

  • Author / Creator
    Zardini Buzatto, Adriana
  • Lipids are a large class of hydrophobic molecules involved in energy storage, signaling, modulation of gene expression and membranes. Lipidomics focuses on the comprehensive analysis of lipids and their interactions. Although the potential of lipidomics to study physiological and pathological processes is undeniable, reliable methodologies for the comprehensive assessment of the lipidome in biological samples are still needed.
    Many biological samples are available in limited amounts and display very complex compositions. Nano-scale liquid chromatography allied to mass spectrometry (nanoLC-MS) offers extremely high sensitivity, although it is known to be technically more challenging than conventional liquid chromatography. The first part of this work describes the optimization of a nanoLC-MS method for routine analysis of the lipidome of small volumes of biological samples (1.0 to 2.5 µL) with high sensitivity. The method was employed to study the composition of blood serum, cerebrospinal fluid and intraparenchymal microdialysate samples. An application of the method to study extremely diluted exosome samples is also discussed. The second part of this work focuses on untargeted, comprehensive lipidomics of biological samples by ultra-high-performance liquid chromatography (UHPLC) coupled to mass spectrometry to study the physiological and pathological effects of different conditions. First, the mechanism of action of a novel vaccine against respiratory syncytial virus was investigated in a rat model by a combination of untargeted lipidomics and chemical isotope labeling metabolomics. Second, untargeted lipidomics of serum was further employed to identify novel biomarkers of Parkinson’s disease and predict the progression to dementia up to three years before noticeable symptoms, emphasizing the relationship of lipids with neurological diseases. Third, alterations in the lipid metabolism related to cystic fibrosis, a severe genetic condition that causes permanent lung damage, showcases the importance of odd-chain fatty acids, previously seen as irrelevant in humans due to their inherent low concentrations, for pathological processes.
    This work illustrates that lipidomic profiling can provide a comprehensive understanding of metabolic alterations caused by physiological and pathological processes in the organism. The potential of high-quality untargeted lipidomics studies for physiological and pathogenesis analyses, as well as for biomarker discovery, is further discussed.

  • Subjects / Keywords
  • Graduation date
    Fall 2020
  • Type of Item
  • Degree
    Doctor of Philosophy
  • DOI
  • License
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