Plasma sphingosine 1-phosphate metabolism and analysis.
The importance of sphingosine 1-phosphate (Sph-1-P) as an intercellular sphingolipid mediator has been established in various systems, and this is especially true in the areas of vascular biology and immunology. Blood platelets store Sph-1-P abundantly and release this bioactive lysophospholipid extracellularly upon stimulation, while vascular endothelial cells and smooth muscle cells respond dramatically to this platelet-derived bioactive lipid. Most of the responses elicited by extracellular Sph-1-P are believed to be mediated by G protein-coupled cell surface receptors, i.e., S1Ps. It is likely that regulation of Sph-1-P biological activity could be important for therapeutics, including but not limited to control of vascular disorders. Furthermore, elucidation of the mechanisms by which the levels of Sph-1-P in the blood are regulated seems important. Accordingly, the application of Sph-1-P analysis to laboratory medicine may be an important task in clinical medicine. In this review, Sph-1-P-related metabolism in the plasma will be summarized. Briefly, the levels and bioactivities of plasma Sph-1-P in vivo may be regulated by various factors, including Sph-1-P release from platelets (and red blood cells, based upon the recent reports), Sph-1-P distribution between albumin and lipoproteins, and S1P expression and lipid phosphate phosphatase activity on the cell surface. Then, application of Sph-1-P analysis to laboratory medicine will be discussed.
Yatomi
Yutaka
Y
Department of Clinical Laboratory Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan. yatoyuta-tky@umin.ac.jp
D006801:Humans; D008246:Lysophospholipids / Q000097:blood* / Q000378:metabolism*; D010749:Phosphoprotein Phosphatases / Q000378:metabolism; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000097:blood / Q000378:metabolism
D008246:Lysophospholipids; C060506:sphingosine 1-phosphate; D010749:Phosphoprotein Phosphatases; D013110:Sphingosine