PECAM-1 (CD31) regulates a hydrogen peroxide-activated nonselective cation channel in endothelial cells.
Hydrogen peroxide (H2O2) released by neutrophils is an important mediator of endothelial cell (EC) injury and vascular inflammation via its effect on EC-free Ca2+, [Ca2+]i. Although the underlying mechanisms are not well understood, platelet endothelial cell adhesion molecule (PECAM)-1/CD-31 is a critical modulator of neutrophil-EC transmigration. PECAM-1 is also known to regulate EC calcium signals and to undergo selective tyrosine phosphorylation. Here, we report that PECAM-1 molecules transduce EC responses to hydrogen peroxide. In human umbilical vein EC and REN cells (a PECAM-1-negative EC-like cell line) stably transfected with PECAM-1 (RHP), noncytolytic H2O2 exposure (100-200 microM H2O2) activated a calcium-permeant, nonselective cation current, and a transient rise in [Ca2+]i of similar time course. Neither response was observed in untransfected REN cells, and H2O2-evoked cation current was ablated in REN cells transfected with PECAM-1 constructs mutated in the cytoplasmic tyrosine-containing domain. The PECAM-dependent H2O2 current was inhibited by dialysis of anti-PECAM-1 cytoplasmic domain antibodies, required Src family tyrosine kinase activity, was independent of inositol trisphosphate receptor activation, and required only an intact PECAM-1 cytoplasmic domain. PECAM-1-dependent H2O2 currents and associated [Ca2+]i transients may play a significant role in regulating neutrophil-endothelial interaction, as well as in oxidant-mediated endothelial response and injury.
Ji
Guangju
G
Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pennsylvania School of Medicine, Philadelphia 19104, USA.
O'Brien
Christopher D
CD
Feldman
Morris
M
Manevich
Yefim
Y
Lim
Poay
P
Sun
Jing
J
Albelda
Steven M
SM
Kotlikoff
Michael I
MI
D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000378:metabolism; D027682:Cation Transport Proteins / Q000378:metabolism*; D002460:Cell Line; D003593:Cytoplasm; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D053496:Inositol 1,4,5-Trisphosphate Receptors; D007811:Lanthanum / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D016877:Oxidants / Q000494:pharmacology*; D018408:Patch-Clamp Techniques; D010716:Phosphatidylinositols / Q000378:metabolism; D010766:Phosphorylation; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism; D014162:Transfection; D014443:Tyrosine / Q000378:metabolism; D014471:Umbilical Veins / Q000166:cytology; D019061:src-Family Kinases / Q000378:metabolism
D015220:Calcium Channels; D027682:Cation Transport Proteins; C506926:ITPR1 protein, human; D053496:Inositol 1,4,5-Trisphosphate Receptors; D016877:Oxidants; D010716:Phosphatidylinositols; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D018160:Receptors, Cytoplasmic and Nuclear; D014443:Tyrosine; D007811:Lanthanum; D006861:Hydrogen Peroxide; D019061:src-Family Kinases; D002118:Calcium