Magwenzi, S, Woodward, C, Wraith, KS et al. (9 more authors) (2017) Oxidized LDL activates blood platelets through CD36/NOX2–mediated inhibition of the cGMP/protein kinase G signaling cascade. Blood, 125 (17). pp. 2693-2703. ISSN 0006-4971
Abstract
Oxidized low-density lipoprotein (oxLDL) promotes unregulated platelet activation in dyslipidemic disorders. Although oxLDL stimulates activatory signaling, it is unclear how these events drive accelerated thrombosis. Here, we describe a mechanism for oxLDL- mediated platelet hyperactivity that requires generation of reactive oxygen species (ROS). Under arterial flow, oxLDL triggered sustained generation of platelet intracellular ROS, which was blocked by CD36 inhibitors, mimicked by CD36-specific oxidized phospholipids, and ablated in CD362/2 murine platelets. oxLDL-induced ROS generation was blocked by the reduced NAD phosphate oxidase 2 (NOX2) inhibitor, gp91ds-tat, and absent in NOX22/2 mice. The synthesis of ROS by oxLDL/CD36 required Src-family kinases and protein kinase C (PKC)-dependent phosphorylation and activation of NOX2. In functional assays, oxLDL abolished guanosine 39,59-cyclic monophosphate (cGMP)- mediated signaling and inhibited platelet aggregation and arrest under flow. This was prevented by either pharmacologic inhibition of NOX2 in human platelets or genetic ablation of NOX2 in murine platelets. Platelets from hyperlipidemic mice were also found to have a diminished sensitivity to cGMP when tested ex vivo, a phenotype that was corrected by infusion of gp91ds-tat into the mice. This study demonstrates that oxLDL and hyperlipidemia stimulate the generation of NOX2-derived ROS through a CD36-PKC pathway and may promote platelet hyperactivity through modulation of cGMP signaling.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Medicine and Health (Leeds) > School of Medicine (Leeds) > Leeds Institute of Genetics, Health and Therapeutics (LIGHT) > Academic Unit of Cardiovascular Medicine (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 26 Sep 2017 15:06 |
Last Modified: | 26 Sep 2017 15:06 |
Status: | Published |
Publisher: | American Society of Hematology |
Identification Number: | 10.1182/blood-2014-05-574491 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:120617 |