Sphingolipids and their carriers

Bioactive sphingolipids have emerged as critical players in inflammation and metabolic diseases. The major metabolites of sphingolipids, including ceramides and sphingosine-1-phosphate (S1P), are often elevated in blood plasma and injured tissues. But they do not freely exist. Instead, they are carried by so-called chaperone molecules such as high-density lipoprotein (HDL), low-density lipoproteins (LDL), and serum albumin, as well as by recently emerging carriers, extracellular vesicles. In this short review, we briefly summarize the current knowledge about the role of sphingolipids in various diseases and describe how sphingolipids are associated with their carriers for their functions. Some issues are highlighted such as S1P negatively correlated with apolipoprotein M of HDL in obesity, adaptive immune responses driven by native LDLs rather than oxidized LDLs, and sphingolipid exchange between HDL and LDL or albumin. This review aims to show the importance of sphingolipid carriers in disease processes and in the development of effective therapeutics.