Development of a derivatization workflow for the semi-targeted spatially-resolveddetection of oxidized lipids by matrix-assisted laser desorption/ionisation-mass spectrometry imaging (MALDI-MSI)

• Applicant: Dr. Patricia Prabutzki
• Subject Area: Analytical Chemistry
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 565977762

Lipids are an extremely diverse group of biomolecules, which are not merely passive building blocks of cell membranes. They possess a multitude of different functions including energy storage, metabolism, cellular signaling and immunomodulation. The lipid composition of various tissues is carefully regulated, but oxidative stress can disrupt lipid metabolism. In particular, the reaction of reactive oxygen species (ROS) with polyunsaturated fatty acids (PUFAs) within complex lipids leads to the formation of oxidized lipids including reactive carbonyl compounds, which can damage proteins and other biomolecules. Some of these non-enzymatically generated oxidized lipids are now recognized to act as important mediators in the development of oxidative-stress related diseases, such as atherosclerosis, metabolic dysfunction-associated steatotic liver disease (MASLD) and hepatocellular carcinoma. The role of (oxidized) lipids in the tumor development is particularly interesting as lipids affect the tumor microenvironment at every stage of cancer progression including the suppression of defensive immune responses. Despite increasing interest in the role and function of oxidized lipids, their analysis is very difficult and improved methods are urgently required. Spatial information on the localization of oxidized lipids, in particular, can further improve our understanding of their roles in disease mechanisms, pathology and progression. This also includes the query for potential oxidation sites in the related tissues. Thus, matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) represents a suitable tool to expand our understanding of these physiologically relevant molecules. The detection of oxidized lipids, however, is typically aggravated by their very low abundance in comparison to their non-oxidized counterparts and their high structural diversity. These obstacles need to be overcome, in order to investigate the functional role and relevance of oxidized lipids in hepatocellular carcinoma using MALDI-MSI. One potential way for the improved analysis of oxidized lipids is the use of specific derivatization reagents, such as 2,4-dinitrophenylhydrazine (DNPH), 7-(diethylamino)-coumarin-3-carbohydrazide (CHH) and 2-picolylamine (2-PA). The main aim of this project is, therefore, to develop a derivatization workflow in order to enhance the sensitivity and selectivity for the semi-targeted detection of oxidized lipids in MALDI-MSI. By employing the developed methodology to decipher the spatial distribution of oxidized lipids in non-diseased liver tissue and hepatocellular carcinoma, the proposed method will allow the visualization of oxidized lipid distributions. The molecular spatial information will further our understanding of their roles in cellular processes and disease states, i.e. tumor growth or resistance to destruction by the innate immune system.

• DFG Programme: WBP Fellowship
• International Connection: Netherlands
• Host: Professorin Eva Cuypers