Atherogenic lipid stress induces platelet hyperactivity through CD36-mediated hyposensitivity to prostacyclin: the role of phosphodiesterase 3A
Martin Berger,
Zaher Raslan,
Ahmed Aburima,
Simbarashe Magwenzi,
Katie S. Wraith,
Benjamin E.J. Spurgeon,
Matthew S. Hindle,
Robert Law,
Maria Febbraio,
Khalid M. Naseem
Affiliations
Martin Berger
Centre for Cardiovascular and Metabolic Research, Hull York Medical School, University of Hull, Hull, UK;Department of Internal Medicine 1, University Hospital RWTH Aachen, Aachen, Germany;Discovery and Translational Science Department, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
Zaher Raslan
Discovery and Translational Science Department, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
Ahmed Aburima
Centre for Cardiovascular and Metabolic Research, Hull York Medical School, University of Hull, Hull, UK
Simbarashe Magwenzi
Centre for Cardiovascular and Metabolic Research, Hull York Medical School, University of Hull, Hull, UK
Katie S. Wraith
Centre for Cardiovascular and Metabolic Research, Hull York Medical School, University of Hull, Hull, UK
Benjamin E.J. Spurgeon
Discovery and Translational Science Department, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
Matthew S. Hindle
Discovery and Translational Science Department, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
Robert Law
Centre for Cardiovascular and Metabolic Research, Hull York Medical School, University of Hull, Hull, UK
Maria Febbraio
School of Dentistry, University of Alberta, Edmonton, AB, Canada
Khalid M. Naseem
Centre for Cardiovascular and Metabolic Research, Hull York Medical School, University of Hull, Hull, UK;Discovery and Translational Science Department, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
Prostacyclin (PGI2) controls platelet activation and thrombosis through a cyclic adenosine monophosphate (cAMP) signaling cascade. However, in patients with cardiovascular diseases this protective mechanism fails for reasons that are unclear. Using both pharmacological and genetic approaches we describe a mechanism by which oxidized low density lipoproteins (oxLDL) associated with dyslipidemia promote platelet activation through impaired PGI2 sensitivity and diminished cAMP signaling. In functional assays using human platelets, oxLDL modulated the inhibitory effects of PGI2, but not a phosphodiesterase (PDE)-insensitive cAMP analog, on platelet aggregation, granule secretion and in vitro thrombosis. Examination of the mechanism revealed that oxLDL promoted the hydrolysis of cAMP through the phosphorylation and activation of PDE3A, leading to diminished cAMP signaling. PDE3A activation by oxLDL required Src family kinases, Syk and protein kinase C. The effects of oxLDL on platelet function and cAMP signaling were blocked by pharmacological inhibition of CD36, mimicked by CD36-specific oxidized phospholipids and ablated in CD36−/− murine platelets. The injection of oxLDL into wild-type mice strongly promoted FeCl3-induced carotid thrombosis in vivo, which was prevented by pharmacological inhibition of PDE3A. Furthermore, blood from dyslipidemic mice was associated with increased oxidative lipid stress, reduced platelet sensitivity to PGI2 ex vivo and diminished PKA signaling. In contrast, platelet sensitivity to a PDE-resistant cAMP analog remained normal. Genetic deletion of CD36 protected dyslipidemic animals from PGI2 hyposensitivity and restored PKA signaling. These data suggest that CD36 can translate atherogenic lipid stress into platelet hyperactivity through modulation of inhibitory cAMP signaling.
