Abstract
Ca2+ signaling plays an important role in endothelial cell (EC) functions including the regulation of barrier integrity. Recently, the endogenous lipid derivative, sphingosine-1-phosphate (S1P), has emerged as an important modulator of EC barrier function. We investigated the role of endogenously generated S1P in Ca2+ metabolism and barrier function in human umbilical endothelial cells (HUVECs) stimulated by thrombin, histamine, or other agonists. Barrier function was assessed by dextran diffusion through HUVEC monolayers, and Ca2+ transients were measured using a fluoroprobe. Thrombin or histamine increased Ca2+ release from the endoplasmic reticulum (ER) and Ca2+ entry through store-operated channels (SOCs) that was accompanied by increased EC permeability. Inhibition of S1P synthesis by a specific sphingosine kinase inhibitor (SKI) decreased thrombin or histamine-induced increased permeability and decreased Ca 2+ entry via SOC in a concentration-dependent fashion. SKI had minuscule effects on thrombin or histamine-induced Ca2+ release from ER. SKI also inhibited thapsigargin or ionomycin-induced Ca2+ entry via SOC without affecting Ca2+ release from the ER. In contrast to the effects of endogenously generated S1P, when S1P was administered externally, it initiated Ca2+ release from ER similar to thrombin and histamine while decreasing EC permeability. These observations indicate that after agonist-induced conditions, endogenously generated S1P functions as a positive modulator of Ca2+ entry via SOC and a mediator of increased cell permeability. In contrast, extracellular exposure to S1P has different signaling mechanisms and effects. Thus, the potential dual roles of endogenous and exogenous S1P on EC function need to be considered in pharmacological studies targeting sphingosine metabolism.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 186-191 |
| Number of pages | 6 |
| Journal | Journal of Pharmacology and Experimental Therapeutics |
| Volume | 323 |
| Issue number | 1 |
| DOIs | |
| State | Published - Oct 1 2007 |
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All Science Journal Classification (ASJC) codes
- Molecular Medicine
- Pharmacology
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Sphingosine 1-phosphate has dual functions in the regulation of endothelial cell permeability and Ca2+ metabolism. / Itagaki, Kiyoshi; Yun, Jong; Hengst, Jeremy; Yatani, Atsuko; Hauser, Carl J.; Spolarics, Zoltan; Deitch, Edwin A.
In: Journal of Pharmacology and Experimental Therapeutics, Vol. 323, No. 1, 01.10.2007, p. 186-191.Research output: Contribution to journal › Article
TY - JOUR
T1 - Sphingosine 1-phosphate has dual functions in the regulation of endothelial cell permeability and Ca2+ metabolism
AU - Itagaki, Kiyoshi
AU - Yun, Jong
AU - Hengst, Jeremy
AU - Yatani, Atsuko
AU - Hauser, Carl J.
AU - Spolarics, Zoltan
AU - Deitch, Edwin A.
PY - 2007/10/1
Y1 - 2007/10/1
N2 - Ca2+ signaling plays an important role in endothelial cell (EC) functions including the regulation of barrier integrity. Recently, the endogenous lipid derivative, sphingosine-1-phosphate (S1P), has emerged as an important modulator of EC barrier function. We investigated the role of endogenously generated S1P in Ca2+ metabolism and barrier function in human umbilical endothelial cells (HUVECs) stimulated by thrombin, histamine, or other agonists. Barrier function was assessed by dextran diffusion through HUVEC monolayers, and Ca2+ transients were measured using a fluoroprobe. Thrombin or histamine increased Ca2+ release from the endoplasmic reticulum (ER) and Ca2+ entry through store-operated channels (SOCs) that was accompanied by increased EC permeability. Inhibition of S1P synthesis by a specific sphingosine kinase inhibitor (SKI) decreased thrombin or histamine-induced increased permeability and decreased Ca 2+ entry via SOC in a concentration-dependent fashion. SKI had minuscule effects on thrombin or histamine-induced Ca2+ release from ER. SKI also inhibited thapsigargin or ionomycin-induced Ca2+ entry via SOC without affecting Ca2+ release from the ER. In contrast to the effects of endogenously generated S1P, when S1P was administered externally, it initiated Ca2+ release from ER similar to thrombin and histamine while decreasing EC permeability. These observations indicate that after agonist-induced conditions, endogenously generated S1P functions as a positive modulator of Ca2+ entry via SOC and a mediator of increased cell permeability. In contrast, extracellular exposure to S1P has different signaling mechanisms and effects. Thus, the potential dual roles of endogenous and exogenous S1P on EC function need to be considered in pharmacological studies targeting sphingosine metabolism.
AB - Ca2+ signaling plays an important role in endothelial cell (EC) functions including the regulation of barrier integrity. Recently, the endogenous lipid derivative, sphingosine-1-phosphate (S1P), has emerged as an important modulator of EC barrier function. We investigated the role of endogenously generated S1P in Ca2+ metabolism and barrier function in human umbilical endothelial cells (HUVECs) stimulated by thrombin, histamine, or other agonists. Barrier function was assessed by dextran diffusion through HUVEC monolayers, and Ca2+ transients were measured using a fluoroprobe. Thrombin or histamine increased Ca2+ release from the endoplasmic reticulum (ER) and Ca2+ entry through store-operated channels (SOCs) that was accompanied by increased EC permeability. Inhibition of S1P synthesis by a specific sphingosine kinase inhibitor (SKI) decreased thrombin or histamine-induced increased permeability and decreased Ca 2+ entry via SOC in a concentration-dependent fashion. SKI had minuscule effects on thrombin or histamine-induced Ca2+ release from ER. SKI also inhibited thapsigargin or ionomycin-induced Ca2+ entry via SOC without affecting Ca2+ release from the ER. In contrast to the effects of endogenously generated S1P, when S1P was administered externally, it initiated Ca2+ release from ER similar to thrombin and histamine while decreasing EC permeability. These observations indicate that after agonist-induced conditions, endogenously generated S1P functions as a positive modulator of Ca2+ entry via SOC and a mediator of increased cell permeability. In contrast, extracellular exposure to S1P has different signaling mechanisms and effects. Thus, the potential dual roles of endogenous and exogenous S1P on EC function need to be considered in pharmacological studies targeting sphingosine metabolism.
UR - http://www.scopus.com/inward/record.url?scp=34548831705&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=34548831705&partnerID=8YFLogxK
U2 - 10.1124/jpet.107.121210
DO - 10.1124/jpet.107.121210
M3 - Article
C2 - 17626797
AN - SCOPUS:34548831705
VL - 323
SP - 186
EP - 191
JO - Journal of Pharmacology and Experimental Therapeutics
JF - Journal of Pharmacology and Experimental Therapeutics
SN - 0022-3565
IS - 1
ER -