TANK-binding kinase 1 inhibitor GSK8612 suppresses platelet function and thrombosis via the ERK/P38 signaling pathway

TANK-binding kinase 1 (TBK1) is a protein kinase that contributes to cell signaling and regulates immune responses, apoptosis, and inflammatory processes. However, the role of TBK1 in platelets is unknown. In this study, GSK8612, a TBK1 inhibitor, was used to investigate the connection between TBK1 and collagen- or thrombin-stimulated platelets.

Immunoblot analysis, platelet aggregation, granule release, flow cytometry, adhesion assay, clot retraction, assessment of reactive oxygen species (ROS), evaluation of rat tail bleeding time, rat carotid artery and vein thrombosis model were performed.

This study revealed elevated levels of phosphorylated TBK1 (p-TBK1) in patients with acute myocardial infarction compared to healthy controls. Furthermore, in vitro experiments demonstrated rapid TBK1 phosphorylation upon platelet stimulation. GSK8612, a specific TBK1 inhibitor, suppressed platelet aggregation, granule secretion, adhesion, and clot retraction. GSK8612 prolonged rat tail bleeding time and inhibited both the arterial and vein thrombotic process. However, it did not affect platelet counts, coagulation, or key receptor expression such as glycoprotein (GP) VI, GPIbα, and integrin αIIbβ3. Correspondingly, GSK8612 significantly attenuated ROS generation in activated platelets. It significantly suppressed the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and p38 mitogen-activated protein kinase (p38 MAPK), indicating that TBK1 inhibition disrupts redox balance and downregulates MAPK-mediated pro-thrombotic signaling.

Pharmacological inhibition of TBK1 impaired platelet function and thrombus formation, an effect that may be attributed to the suppression of ROS generation via the ERK/P38 signaling axis. This finding suggests that TBK1 may be a new target for treating thrombotic or cardiovascular occlusion diseases.