Imaging of intracellular fatty acids by scanning X-ray fluorescence microscopy
Résumé
Fatty acids are taken up by cells and incorporated into complex lipids such as neutral lipids and glycerophospholipids. Glycerophospholipids are major constituents of cellular membranes. More than 1000 mol. species of glycerophospholipids differ in their polar head groups and fatty acid compns. They are related to cellular functions and diseases and have beenwell analyzed by mass spectrometry. However, intracellular imaging of fatty acids and glycerophospholipids has not been successful due to insufficient resoln. using conventional methods. Here, we developed a method for labeling fatty acids with bromine (Br) and applied scanning X-ray fluorescence microscopy (SXFM) to obtain intracellular Br mapping data with submicrometer resoln. Mass spectrometry showed that cells took up Br-labeled fatty acids andmetabolized them mainly into glycerophospholipids in CHO cells. Most Br signals obsd. by SXFM were in the perinuclear region. Higher resoln. revealed a spot-like distributionofBr inthe cytoplasm.The current method enabled successful visualization of intracellular Br-labeled fatty acids. Single-element labeling combined with SXFM technol. facilitates the intracellular imaging of fatty acids, which provides a new tool to det. dynamic changes in fatty acids and their derivs. at the single-cell level.
Domaines
Chimie
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