A platelet secretion pathway mediated by cGMP-dependent protein kinase

Zhenyu Li, Guoying Zhang, Jasna Ajdic Marjanovic, Changgeng Ruan, Xiaoping Du

Research output: Contribution to journalArticlepeer-review

65 Scopus citations

Abstract

Platelet secretion (exocytosis) is critical in amplifying platelet activation, in stabilizing thrombi, and in arteriosclerosis and vascular remodeling. The signaling mechanisms leading to secretion have not been well defined. We have shown previously that cGMP-dependent protein kinase (PKG) plays a stimulatory role in platelet activation via the glycoprotein Ib-IX pathway. Here we show that PKG also plays an important stimulatory role in mediating aggregation-dependent platelet secretion and secretion-dependent second wave platelet aggregation, particularly those induced via Gq-coupled agonist receptors, the thromboxane A2 (TXA2) receptor, and protease-activated receptors (PARs). PKG I knock-out mouse platelets and PKG inhibitor-treated human platelets showed diminished aggregation-dependent secretion and also showed a diminished secondary wave of platelet aggregation induced by a TXA2 analog and thrombin receptor-activating peptides that were rescued by the granule content ADP. Low dose collagen-induced platelet secretion and aggregation were also reduced by PKG inhibitors. Furthermore PKG I knock-out and PKG inhibitors significantly attenuated activation of the Gi pathway that is mediated by secreted ADP. These data unveil a novel PKG-dependent platelet secretion pathway and a mechanism by which PKG promotes platelet activation.

Original languageEnglish
Pages (from-to)42469-42475
Number of pages7
JournalJournal of Biological Chemistry
Volume279
Issue number41
DOIs
StatePublished - Oct 8 2004

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

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