Levels of Talin1 in Platelet-Derived Microvesicles Affect Platelet Activation in Patients with Nonvalvular Atrial Fibrillation.

Abstract

This study evaluated talin1 expression in platelets and platelet-derived microvesicles (PMVs) from nonvalvular atrial fibrillation (NVAF) patients. Meanwhile, this study analyzed the impacts of talin1 expression in PMVs on platelet activation. Twelve healthy controls and 38 NVAF patients were recruited in this study. The levels of talin1 and RAP1B activation were observed in the platelets and PMVs from the participants, and their levels were significantly increased in the NVAF patients compared to the healthy controls (P < 0.01). Talin1 silence in MEG-01 cells was obtained by transfecting talin1 siRNA, and the cells were stimulated by thrombin receptor-activating peptide 6 (TRAP-6) to induce platelet-dense granule secretion. TRAP-6 stimulation increased the talin1 expression and RAP1B activation in the platelet-like particles from MEG-01 cells, but talin1 silence suppressed the TRAP-6-stimulated RAP1B activation and CD62p expression in the platelet-like particle. Moreover, the platelets from healthy donors were activated by the PMVs from the TRAP-6-stimulated MEG-01 cells. However, the decreased talin1 level in the PMVs from MEG-01 cells weakened the platelet activation. This study suggested that talin1 expression in the PMVs affected platelet activation in patients with NVAF.