title: Ceramide 1-phosphate mediates endothelial cell invasion via the annexin a2-p11 heterotetrameric protein complex.
abstract: The bioactive sphingolipid, ceramide 1-phosphate (C-1-P), has been implicated as an extracellular chemotactic agent directing cellular migration in hematopoietic stem/progenitor cells and macrophages. However, interacting proteins that could mediate these actions of C-1-P have, thus far, eluded identification. We have now identified and characterized interactions between ceramide 1-phosphate and the annexin a2-p11 heterotetramer constituents. This C-1-P-receptor complex is capable of facilitating cellular invasion. Herein, we demonstrate in both coronary artery macrovascular endothelial cells and retinal microvascular endothelial cells that C-1-P induces invasion through an extracellular matrix barrier. By employing surface plasmon resonance, lipid-binding ELISA, and mass spectrometry technologies, we have demonstrated that the heterotetramer constituents bind to C-1-P. Although the annexin a2-p11 heterotetramer constituents do not bind the lipid C-1-P exclusively, other structurally similar lipids, such as phosphatidylserine, sphingosine 1-phosphate, and phosphatidic acid, could not elicit the potent chemotactic stimulation observed with C-1-P. Further, we show that siRNA-mediated knockdown of either annexin a2 or p11 protein significantly inhibits C-1-P-directed invasion, indicating that the heterotetrameric complex is required for C-1-P-mediated chemotaxis. These results imply that extracellular C-1-P, acting through the extracellular annexin a2-p11 heterotetrameric protein, can mediate vascular endothelial cell invasion.
authors.affiliation: Department of Pharmacology, Penn State University College of Medicine, Hershey, Pennsylvania 17033, USA.
authors.forename: Jody L
authors.initials: JL
authors.lastname: Hankins
authors.forename: Katherine E
authors.initials: KE
authors.lastname: Ward
authors.forename: Sam S
authors.initials: SS
authors.lastname: Linton
authors.forename: Brian M
authors.initials: BM
authors.lastname: Barth
authors.forename: Robert V
authors.initials: RV
authors.lastname: Stahelin
authors.forename: Todd E
authors.initials: TE
authors.lastname: Fox
authors.forename: Mark
authors.initials: M
authors.lastname: Kester
mesh_terms: D017306:Annexin A2 / Q000378:metabolism*; D002478:Cells, Cultured; D002518:Ceramides / Q000378:metabolism*; D002633:Chemotaxis / Q000502:physiology*; D042783:Endothelial Cells / Q000378:metabolism*; D005109:Extracellular Matrix / Q000378:metabolism; D006801:Humans; D046912:Multiprotein Complexes / Q000378:metabolism*; D009418:S100 Proteins / Q000378:metabolism*; D000099248:S100 Calcium Binding Protein A10
chemical_list: D017306:Annexin A2; D002518:Ceramides; D046912:Multiprotein Complexes; D009418:S100 Proteins; D000099248:S100 Calcium Binding Protein A10; C472822:ANXA2 protein, human; C065576:ceramide 1-phosphate
keywords: Annexin; Annexin a2; Cell Invasion; Ceramide 1-Phosphate; Chemotaxis; Endothelial Cell; Receptor; S100A10; Sphingolipid; p11