Proline-rich tyrosine kinase Pyk2 regulates deep vein thrombosis

Haematologica. 2022 Jun 1;107(6):1374-1383. doi: 10.3324/haematol.2021.279703.

Abstract

Deep vein thrombosis results from the cooperative action of leukocytes, platelets, and endothelial cells. The proline-rich tyrosine kinase Pyk2 regulates platelet activation and supports arterial thrombosis. In this study, we combined pharmacological and genetic approaches to unravel the role of Pyk2 in venous thrombosis. We found that mice lacking Pyk2 almost completely failed to develop deep venous thrombi upon partial ligation of the inferior vena cava. Pyk2-deficient platelets displayed impaired exposure of phosphatidylserine and tissue factor expression by endothelial cells and monocytes was completely prevented by inhibition of Pyk2. In human umbilical vein endothelial cells (HUVEC), inhibition of Pyk2 hampered IL-1b-induced expression of VCAM and P-selectin, and von Willebrand factor release. Pyk2-deficient platelets showed defective adhesion on von Willebrand factor and reduced ability to bind activated HUVEC under flow. Moreover, inhibition of Pyk2 in HUVEC strongly reduced platelet adhesion. Similarly, Pyk2-deficient neutrophils were unable to efficiently roll and adhere to immobilized endothelial cells under venous flow conditions. Moreover, platelets and neutrophils from Pyk2- knockout mice showed defective ability to form heterogeneous aggregates upon stimulation, while platelet monocyte interaction occurred normally. Consequently, platelet neutrophil aggregates, abundant in blood of wild-type mice upon inferior vena cava ligation, were virtually undetectable in Pyk2-knockout mice. Finally, we found that expression of Pyk2 was required for NETosis induced by activated platelets. Altogether our results demonstrate a critical role of Pyk2 in the regulation of the coordinated thromboinflammatory responses of endothelial cells, leukocytes and platelets leading to venous thrombosis. Pyk2 may represent a novel promising target in the treatment of deep vein thrombosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blood Platelets / metabolism
  • Endothelial Cells / metabolism
  • Focal Adhesion Kinase 2 / genetics
  • Focal Adhesion Kinase 2 / metabolism*
  • Humans
  • Mice
  • Phosphorylation
  • Proline / metabolism
  • Venous Thrombosis* / genetics
  • Venous Thrombosis* / metabolism
  • von Willebrand Factor / metabolism

Substances

  • von Willebrand Factor
  • Proline
  • Focal Adhesion Kinase 2
  • PTK2B protein, human
  • Ptk2b protein, mouse

Grants and funding

Funding: This research was supported by the Italian Ministry of Education, University and Research (MIUR): Dipartimenti di Eccellenza Program (2018–2022), Department of Biology and Biotechnology “L. Spallanzani,” University of Pavia, and by Fondazione CARIPLO (2018-0483 to MT and PG).