Lipids | Very Long Fatty Acids in Health and Disease

Fatty acids (FAs) are carboxylic acids with a long aliphatic tail of methyl groups connected through either saturated or unsaturated bonds. Fatty acid molecules are usually joined together in groups of 2–3 forming lipids. Very long-chain fatty acids (VLC-FAs) with a chain longer than 22 carbons exhibit specific functions in the tissues, for example in liver homeostasis, myelin maintenance, skin barrier formation, myelin formation, retinal functions, anti-inflammation, and others. These functions are asserted by fatty acids incorporated in cellular lipids such as sphingolipids and glycerophospholipids but also as precursors of inflammation-resolving lipid signaling molecules. Our understanding of the function of VLC-FAs is growing in parallel with the molecular understanding of the pathways dependent of biophysical properties of lipids and through multidisciplinary studies of a variety of inherited diseases, such as macular degeneration, myopathy, mental retardation, and demyelination, caused by mutations in the genes involved in the biogenesis and metabolism of fatty acids. In this article, we will introduce the structure of VLC-FAs and their function in mammalian tissues. Although the full function and complicated metabolism of these biomolecules are yet to be described in detail, substantial research exists highlighting the importance of these molecules and the disease states resulting from the lack or accumulation of VLC-FAs.