Research Groups

Lipidomics of Laser Capture Microdissected Tissues

Usually, shotgun analysis is used for acquiring a quantitative snapshot of the composition of total lipid extracts from cells, tissues or entire model organisms. Lipids are extracted from the entire sample (e.g. a tissue biopsy) but the analysis does not  demonstrate how lipids were spatially distributed within the specimen. To elucidate the spatial organization of the lipidome at the micro-scale we aim to couple Laser Capture Microdissection (LCM) with shotgun profiling by high-resolution mass spectrometry. We focus on functional units of the liver, so called liver lobules, which show a distinct metabolic zonation. Gradual segregation of metabolic pathways, including lipid anabolism/catabolism is critical for the liver function and is perturbed under many pathological conditions (e.g. metabolic syndrome, nonalcoholic liver disease and hepatocellular cancer). We would like to established how metabolic zonation is associated with the full-lipidome composition of spatially defined 0.25 mm2 patches at the 20 µm slices of liver biopsies.

Shotgun Lipidomics with Spatial Specificity: alliance with Laser Capture Microdissection

Figure 1: To identify pericentral zones in liver cryosections (20 µm thick) we perform immunostaining visualizing glutamine synthetase, which is exclusively expressed in hepatocytes adjacent to central veins. Additionally, we stain nuclei with DAPI to identify periportal regions. Non-stained and non-fixed serial liver cryosections are then used to collect material by laser ablation (AutoLPC) of pericentral/periportal regions.

Oskar Knittelfelder