1. NanoSIMS Analysis of Intravascular Lipolysis and Lipid Movement across Capillaries and into Cardiomyocytes
- Author
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Andrea Holme, Stephen G. Young, Patrick J. Heizer, David A. Ford, Peter Tontonoz, Michael Ploug, Anne P. Beigneux, Christopher M. Allan, Cuiwen He, Haibo Jiang, Xuchen Hu, Karen Reue, Matt R. Kilburn, Paul Guagliardo, Thomas A. Weston, Loren G. Fong, Mikael Larsson, and Rachel S. Jung
- Subjects
Male ,0301 basic medicine ,CD36 Antigens ,Physiology ,CD36 ,Spectrometry, Mass, Secondary Ion ,Mitochondrion ,Medical Biochemistry and Metabolomics ,Inbred C57BL ,Cardiovascular ,Mice ,0302 clinical medicine ,Lipid droplet ,NanoSIMS ,Myocytes, Cardiac ,triglycerides ,Lipoprotein lipase ,biology ,Chemistry ,Fatty Acids ,Cell biology ,Transport protein ,Mitochondria ,lipids (amino acids, peptides, and proteins) ,Cardiac ,Secondary Ion ,Lipolysis ,Lipoproteins ,lipoprotein lipase ,fatty acids ,Article ,03 medical and health sciences ,Endocrinology & Metabolism ,Humans ,Animals ,Molecular Biology ,Triglycerides ,Myocytes ,electron microscopy ,Spectrometry ,Endothelial Cells ,Cell Biology ,Metabolism ,Lipid Droplets ,Mass ,Deuterium ,Capillaries ,Mice, Inbred C57BL ,Lipoprotein Lipase ,030104 developmental biology ,biology.protein ,chylomicrons ,Biochemistry and Cell Biology ,030217 neurology & neurosurgery ,Chylomicron - Abstract
The processing of triglyceride-rich lipoproteins (TRLs) in capillaries provides lipids for vital tissues, but our understanding of TRL metabolism is limited, in part because TRL processing and lipid movement have never been visualized. To investigate the movement of TRL-derived lipids in the heart, mice were given an injection of [2H]triglyceride-enriched TRLs, and the movement of 2H-labeled lipids across capillaries and into cardiomyocytes was examined by NanoSIMS. TRL processing and lipid movement in tissues were extremely rapid. Within 30 s, TRL-derived lipids appeared in the subendothelial spaces and in the lipid droplets and mitochondria of cardiomyocytes. Enrichment of 2H in capillary endothelial cells was not greater than in cardiomyocytes, implying that endothelial cells may not be a control point for lipid movement into cardiomyocytes. Remarkably, a deficiency of the putative fatty acid transport protein CD36, which is expressed highly in capillary endothelial cells, did not impede entry of TRL-derived lipids into cardiomyocytes.
- Published
- 2017
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