Limits...
Mouse SPNS2 functions as a sphingosine-1-phosphate transporter in vascular endothelial cells.

Hisano Y, Kobayashi N, Yamaguchi A, Nishi T - PLoS ONE (2012)

Bottom Line: However, little is known about the molecular mechanism by which S1P is supplied to extracellular environments such as blood plasma.Here, we show that SPNS2 functions as an S1P transporter in vascular endothelial cells but not in erythrocytes and platelets.Moreover, the plasma S1P concentration of SPNS2-deficient mice was reduced to approximately 60% of wild-type, and SPNS2-deficient mice were lymphopenic.

View Article: PubMed Central - PubMed

Affiliation: Department of Cell Membrane Biology, Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka, Japan.

ABSTRACT
Sphingosine-1-phosphate (S1P), a sphingolipid metabolite that is produced inside the cells, regulates a variety of physiological and pathological responses via S1P receptors (S1P1-5). Signal transduction between cells consists of three steps; the synthesis of signaling molecules, their export to the extracellular space and their recognition by receptors. An S1P concentration gradient is essential for the migration of various cell types that express S1P receptors, such as lymphocytes, pre-osteoclasts, cancer cells and endothelial cells. To maintain this concentration gradient, plasma S1P concentration must be at a higher level. However, little is known about the molecular mechanism by which S1P is supplied to extracellular environments such as blood plasma. Here, we show that SPNS2 functions as an S1P transporter in vascular endothelial cells but not in erythrocytes and platelets. Moreover, the plasma S1P concentration of SPNS2-deficient mice was reduced to approximately 60% of wild-type, and SPNS2-deficient mice were lymphopenic. Our results demonstrate that SPNS2 is the first physiological S1P transporter in mammals and is a key determinant of lymphocyte egress from the thymus.

Show MeSH

Related in: MedlinePlus

SPNS2 is an S1P transporter of vascular EC.(A–D) The relative amount of the indicated mRNAs in MAECs isolatedfrom wild-type (WT) and SPNS2-deficient mice (Δ). The amount of eachmRNA was normalized to that of Hprt. (E) CD31expression by MAECs was detected by immunostaining with CD31 antibody.(F) The amount of endogenous S1P released from MAECs. The cells wereincubated with 1% BSA for 4 hr at 37 °C, and the released S1Pwas measured by UPLC-MS/MS. The graphs show the average values fromthree experiments, with error bars representing the standard error.N.D., not detected.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3379171&req=5

pone-0038941-g010: SPNS2 is an S1P transporter of vascular EC.(A–D) The relative amount of the indicated mRNAs in MAECs isolatedfrom wild-type (WT) and SPNS2-deficient mice (Δ). The amount of eachmRNA was normalized to that of Hprt. (E) CD31expression by MAECs was detected by immunostaining with CD31 antibody.(F) The amount of endogenous S1P released from MAECs. The cells wereincubated with 1% BSA for 4 hr at 37 °C, and the released S1Pwas measured by UPLC-MS/MS. The graphs show the average values fromthree experiments, with error bars representing the standard error.N.D., not detected.

Mentions: Mouse aortic ECs (MAECs) were isolated from wild-type and SPNS2-deficient mice tomeasure their S1P release activity. Spns2 mRNA was detected inMAECs isolated from wild-type but not SPNS2-deficient mice (Figure 10A). Cell morphology, the expressionof the EC surface marker CD31 and the mRNA levels of other EC-specific markers(Nos3, Cdh5 and Icam-2)were similar in both genotypes, as determined by immunostaining and quantitativereal-time PCR analysis (Figure10B–10E) [36]. MAECs prepared from wild-type mice showed S1Prelease activity, while SPNS2-deficient MAECs completely lost activity (Figure 10F), indicating thatSPNS2 is the sole S1P transporter of MAECs.


Mouse SPNS2 functions as a sphingosine-1-phosphate transporter in vascular endothelial cells.

Hisano Y, Kobayashi N, Yamaguchi A, Nishi T - PLoS ONE (2012)

SPNS2 is an S1P transporter of vascular EC.(A–D) The relative amount of the indicated mRNAs in MAECs isolatedfrom wild-type (WT) and SPNS2-deficient mice (Δ). The amount of eachmRNA was normalized to that of Hprt. (E) CD31expression by MAECs was detected by immunostaining with CD31 antibody.(F) The amount of endogenous S1P released from MAECs. The cells wereincubated with 1% BSA for 4 hr at 37 °C, and the released S1Pwas measured by UPLC-MS/MS. The graphs show the average values fromthree experiments, with error bars representing the standard error.N.D., not detected.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3379171&req=5

pone-0038941-g010: SPNS2 is an S1P transporter of vascular EC.(A–D) The relative amount of the indicated mRNAs in MAECs isolatedfrom wild-type (WT) and SPNS2-deficient mice (Δ). The amount of eachmRNA was normalized to that of Hprt. (E) CD31expression by MAECs was detected by immunostaining with CD31 antibody.(F) The amount of endogenous S1P released from MAECs. The cells wereincubated with 1% BSA for 4 hr at 37 °C, and the released S1Pwas measured by UPLC-MS/MS. The graphs show the average values fromthree experiments, with error bars representing the standard error.N.D., not detected.
Mentions: Mouse aortic ECs (MAECs) were isolated from wild-type and SPNS2-deficient mice tomeasure their S1P release activity. Spns2 mRNA was detected inMAECs isolated from wild-type but not SPNS2-deficient mice (Figure 10A). Cell morphology, the expressionof the EC surface marker CD31 and the mRNA levels of other EC-specific markers(Nos3, Cdh5 and Icam-2)were similar in both genotypes, as determined by immunostaining and quantitativereal-time PCR analysis (Figure10B–10E) [36]. MAECs prepared from wild-type mice showed S1Prelease activity, while SPNS2-deficient MAECs completely lost activity (Figure 10F), indicating thatSPNS2 is the sole S1P transporter of MAECs.

Bottom Line: However, little is known about the molecular mechanism by which S1P is supplied to extracellular environments such as blood plasma.Here, we show that SPNS2 functions as an S1P transporter in vascular endothelial cells but not in erythrocytes and platelets.Moreover, the plasma S1P concentration of SPNS2-deficient mice was reduced to approximately 60% of wild-type, and SPNS2-deficient mice were lymphopenic.

View Article: PubMed Central - PubMed

Affiliation: Department of Cell Membrane Biology, Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka, Japan.

ABSTRACT
Sphingosine-1-phosphate (S1P), a sphingolipid metabolite that is produced inside the cells, regulates a variety of physiological and pathological responses via S1P receptors (S1P1-5). Signal transduction between cells consists of three steps; the synthesis of signaling molecules, their export to the extracellular space and their recognition by receptors. An S1P concentration gradient is essential for the migration of various cell types that express S1P receptors, such as lymphocytes, pre-osteoclasts, cancer cells and endothelial cells. To maintain this concentration gradient, plasma S1P concentration must be at a higher level. However, little is known about the molecular mechanism by which S1P is supplied to extracellular environments such as blood plasma. Here, we show that SPNS2 functions as an S1P transporter in vascular endothelial cells but not in erythrocytes and platelets. Moreover, the plasma S1P concentration of SPNS2-deficient mice was reduced to approximately 60% of wild-type, and SPNS2-deficient mice were lymphopenic. Our results demonstrate that SPNS2 is the first physiological S1P transporter in mammals and is a key determinant of lymphocyte egress from the thymus.

Show MeSH
Related in: MedlinePlus