Dual roles of tight junction-associated protein, zonula occludens-1, in sphingosine 1-phosphate-mediated endothelial chemotaxis and barrier integrity.

Journal Article

In this report, sphingosine-1-phosphate (S1P), a serum-borne bioactive lipid, is shown to activate tight-junction-associated protein Zonula Occludens-1 (ZO-1), which in turn plays a critical role in regulating endothelial chemotaxis and barrier integrity. After S1P stimulation, ZO-1 was redistributed to the lamellipodia and cell-cell junctions via the S1P1/G(i)/Akt/Rac pathway. Similarly, both endothelial barrier integrity and cell motility were significantly enhanced in S1P-treated cells through the G(i)/Akt/Rac pathway. Importantly, S1P-enhanced barrier integrity and cell migration were abrogated in ZO-1 knockdown cells, indicating ZO-1 is functionally indispensable for these processes. To investigate the underlying mechanisms, we demonstrated that cortactin plays a critical role in S1P-induced ZO-1 redistribution to the lamellipodia. In addition, S1P significantly induced the formation of endothelial tight junctions. ZO-1 and alpha-catenin polypeptides were colocalized in S1P-induced junctional structures; whereas, cortactin was not observed in these regions. Together, these results suggest that S1P induces the formation of two distinct ZO-1 complexes to regulate two different endothelial functions: ZO-1/cortactin complexes to regulate chemotactic response and ZO-1/alpha-catenin complexes to regulate endothelial barrier integrity. The concerted operation of these two ZO-1 complexes may coordinate two important S1P-mediated functions, i.e. migration and barrier integrity, in vascular endothelial cells.

Full Text

Duke Authors

Cited Authors

  • Lee, J-F; Zeng, Q; Ozaki, H; Wang, L; Hand, AR; Hla, T; Wang, E; Lee, M-J

Published Date

  • September 29, 2006

Published In

Volume / Issue

  • 281 / 39

Start / End Page

  • 29190 - 29200

PubMed ID

  • 16891661

International Standard Serial Number (ISSN)

  • 0021-9258

Digital Object Identifier (DOI)

  • 10.1074/jbc.M604310200

Language

  • eng

Conference Location

  • United States