| First Author | Kalwa H | Year | 2014 |
| Journal | Proc Natl Acad Sci U S A | Volume | 111 |
| Issue | 9 | Pages | 3383-8 |
| PubMed ID | 24550450 | Mgi Jnum | J:207408 |
| Mgi Id | MGI:5556339 | Doi | 10.1073/pnas.1320854111 |
| Citation | Kalwa H, et al. (2014) Central role for hydrogen peroxide in P2Y1 ADP receptor-mediated cellular responses in vascular endothelium. Proc Natl Acad Sci U S A 111(9):3383-8 |
| abstractText | ADP activates a family of cell surface receptors that modulate signaling pathways in a broad range of cells. ADP receptor antagonists are widely used to treat cardiovascular disease states. These studies identify a critical role for the stable reactive oxygen species hydrogen peroxide (H2O2) in mediating cellular responses activated by the G protein-coupled P2Y1 receptor for ADP. We found that ADP-dependent phosphorylation of key endothelial signaling proteins-including endothelial nitric oxide synthase, AMP-activated protein kinase, and the actin-binding MARCKS protein-was blocked by preincubation with PEG-catalase, which degrades H2O2. ADP treatment promoted the H2O2-dependent phosphorylation of c-Abl, a nonreceptor tyrosine kinase that modulates the actin cytoskeleton. Cellular imaging experiments using fluorescence resonance energy transfer-based biosensors revealed that ADP-stimulated activation of the cytoskeleton-associated small GTPase Rac1 was independent of H2O2. However, Rac1-dependent activation of AMP-activated protein kinase, the signaling phospholipid phosphatidylinositol-(4, 5)-bisphosphate, and the c-Abl-interacting protein CrkII are mediated by H2O2. We transfected endothelial cells with differentially targeted HyPer2 H2O2 biosensors and found that ADP promoted a marked increase in H2O2 levels in the cytosol and caveolae, and a smaller increase in mitochondria. We performed a screen for P2Y1 receptor-mediated receptor tyrosine kinase transactivation and discovered that ADP transactivates Fms-like tyrosine kinase 3 (Flt3), a receptor tyrosine kinase expressed in these cells. Our observation that P2Y1 receptor-mediated responses involve Flt3 transactivation may identify a unique mechanism whereby cancer chemotherapy with receptor tyrosine kinase inhibitors promotes vascular dysfunction. Taken together, these findings establish a critical role for endogenous H2O2 in control of ADP-mediated signaling responses in the vascular wall. |
