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Live cell imaging of lipid droplet breakdown and growth in adipocytes
Author(s) -
Wolinski Heimo,
Paar Margret,
Jüngst Christian,
Steiner Noemi A.,
Kolb Dagmar,
Lass Achim,
Zimmermann Robert,
Zumbusch Andreas,
Kohlwein Sepp D.
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.597.5
Subject(s) - lipid droplet , organelle , lipid metabolism , biophysics , chemistry , lipotoxicity , microbiology and biotechnology , fluorescence microscope , lipid microdomain , cell , phospholipid , biochemistry , biology , fluorescence , membrane , physics , quantum mechanics , insulin , endocrinology , insulin resistance
Lipid droplets (LDs) are the main lipid storage depots for neutral lipids (‘fat’) mainly triacylglycerols (TAGs) in all eukaryotic cells. Synthesis, storage, and mobilization of TAGs are critical cellular processes to maintain cellular lipid and energy homeostasis. Although many molecular and biochemical details of neutral lipid metabolism have been revealed basic cell biological aspects of LDs such as the mode of LD breakdown and of LD growth are still elusive. We have applied label‐free coherent anti‐Stokes Raman scattering (CARS) microscopy, long‐term four‐dimensional live cell imaging and three‐dimensional electron microscopy to study lipid droplet remodelling in intact murine and human adipocytes. We show that under selected nutritional conditions neutral lipid breakdown and synthesis can occur in parallel and suggest an underlying mechanism to prevent cellular lipid overflow and lipotoxicity. Furthermore, we demonstrate that LD of adipocytes grow by lipid transfer between closely associated organelles without physical interaction over large LD surface areas. In addition, we demonstrate the specific detection of isotope labeled fatty acids and their incorporation into LD using CARS microscopy. Advantages and limitations of chemical imaging versus fluorescence labeling for monitoring lipids in intact cells are discussed. FWF, LIPOTOX F3005‐B12; DK‐ME W901‐B05, GOLD (GEN‐AU); KoRS‐CB; BWS.