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Sphingosine 1‐phosphate enhances endothelial barrier function through a Rho‐kinase pathway independent of VE‐cadherin
Author(s) -
Xu Mei,
Hu Chuan,
Waters Christopher L,
Minnear Fred L
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.4.a707
Subject(s) - sphingosine 1 phosphate , ve cadherin , cadherin , microbiology and biotechnology , chemistry , sphingosine kinase 1 , barrier function , function (biology) , sphingosine , biochemistry , biology , receptor , cell
Sphingosine 1‐phosphate (S1P) induces a myriad of cellular events including an increase in endothelial barrier function. In the present study, we determined if the barrier‐enhancing activity of S1P depends on Ca 2+ ‐dependent, VE‐cadherin binding and Rho kinase. Endothelial cell monolayers derived from human umbilical veins were incubated with EGTA to chelate extracellular Ca 2+ . EGTA reduced VE‐cadherin at intercellular junctions, caused cell separation, and decreased endothelial electrical resistance. Replenishment of extracellular Ca 2+ with MCDB restored VE‐cadherin and caused a slow recovery of electrical resistance. S1P in the presence of MCDB restored VE‐cadherin to a greater extent than with MCDB alone and induced a rapid increase in endothelial electrical resistance. S1P alone did not restore VE‐cadherin but also rapidly increased electrical resistance. The increased electrical resistance was sustained for 3 h after treatment with S1P and MCDB but was transient and declined to basal level by 3 h with treatment of S1P alone. S1P also transiently increased electrical resistance in cell monolayers incubated with an anti‐VE‐cadherin antibody. Pretreatment with Y‐27632, a Rho kinase inhibitor, before the addition of EGTA attenuated the S1P‐induced increase in electrical resistance. We conclude that the increase in barrier function afforded by S1P requires Rho kinase and is independent of homophilic VE‐cadherin binding, but VE‐cadherin may be necessary to sustain the barrier‐enhancing activity of S1P. (Supported by HL‐68079).