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The concentration of sphingosine 1-phosphate (S1P) in plasma or serum is much higher than the half-maximal concentration of the sphingolipid needed to stimulate its receptors. Nevertheless, the inositol phosphate response to plasma or serum mediated by Edg-3, one of the S1P receptors, which was overexpressed in Chinese hamster ovary cells, was much smaller(More)
We examined the actions of sphingosine 1-phosphate (S1P) on signaling pathways in Chinese hamster ovary cells transfected with putative S1P receptor subtypes, i.e. Edg-1, AGR16/H218 (Edg-5), and Edg-3. Among these receptor-transfected cells, there was no significant difference in the expressing numbers of the S1P receptors and their affinities to S1P, which(More)
It has been suggested that lipoproteins in the central nervous system are involved in the regulation of several neural functions independent of cholesterol metabolism as well as those related to lipid metabolism. We recently demonstrated that lipoproteins are carriers for sphingosine 1-phosphate (S1P). This raised the possibility that S1P mediates the(More)
Sphingosine 1-phosphate (S1P) is accumulated in lipoproteins, especially high-density lipoprotein (HDL), in plasma. However, it remains uncharacterized how extracellular S1P is produced in the CNS. The treatment of rat astrocytes with retinoic acid and dibutyryl cAMP, which induce apolipoprotein E (apoE) synthesis and HDL-like lipoprotein formation,(More)
Sphingosine 1-phosphate (S1P), a novel lipid mediator, is concentrated in the fraction of lipoproteins that include high density lipoprotein (HDL) and low density lipoprotein (LDL) in human plasma. Here, we show that oxidation of LDL resulted in a marked reduction in the S1P level in association with a marked accumulation of lysophosphatidylcholine (LPC).(More)
T cell death-associated gene 8 (TDAG8) has been reported to be a receptor for psychosine. Ovarian cancer G-protein-coupled receptor 1 (OGR1) and GPR4, G-protein-coupled receptors (GPCRs) closely related to TDAG8, however, have recently been identified as proton-sensing or extracellular pH-responsive GPCRs that stimulate inositol phosphate and cAMP(More)
BACKGROUND Extracellular sphingosine 1-phosphate (S1P) has been shown to contribute to the action of high density lipoprotein (HDL) on endothelial and smooth muscle cells. We examined the relationship of lipoprotein-associated S1P concentrations with cholesterol (C) and apolipoprotein (apo) contents of lipoprotein and lipoprotein subfractions characterized(More)
Genitourinary anomalies can present a formidable challenge to the vascular surgeon at abdominal aortic reconstruction. We saw a case of crossed renal ectopia without fusion, a rare anomaly, associated with abdominal aortic aneurysm. Because of risk for injury to the kidney during surgery, preoperative evaluation of this anomaly must include computed(More)
Sphingosine 1-phosphate (S1P) stimulates thymidine incorporation (DNA synthesis), cell growth and cell migration in human aortic endothelial cells (HAECs). The extent of the S1P-induced responses are comparable to those stimulated by vascular endothelial growth factor, one of the most potent stimulators of angiogenesis. These responses to S1P were mimicked(More)
We characterized the molecular mechanisms by which high density lipoprotein (HDL) inhibits the expression of adhesion molecules, including vascular cell adhesion molecule-1 and intercellular adhesion molecule-1, induced by sphingosine 1-phosphate (S1P) and tumor necrosis factor (TNF) alpha in endothelial cells. HDL inhibited S1P-induced nuclear factor(More)