Myr-RKEFAK Peptide Selectively Regulates Outside-in Signaling Transduction-related Functions in Human Platelets / 中国实验血液学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To study the effect of interaction of the talin rod domain integrin binding site 2 with integrin β3 on platelet signal transduction.</p><p><b>METHODS</b>A peptide that mimics the membrane proximal α helix 6 residues R724 KEFAK729 of the integrin β3 cytoplasmic tails was designed and synthesized, to which the myristoylation was covalently linked to the N-terminal of the peptide enabling membrane penetration. The effects of myr-RKEFAK peptide on the typical platelet outside-in signaling ovent (stable adhesion and spreading on immobilized fibrinogen, aggregation, fibrin clot retraction) and inside-out signaling events (soluble fibrinogen binding) were tested.</p><p><b>RESULTS</b>myr-RKEFAK peptide dose-dependently inhibited platelet stable adhesion and spreading on immobilized fibrinogen, irreversible aggregation, as well as fibrin clot retraction, but not soluble fibrinogen binding and reversible phase of platelet aggregation.</p><p><b>CONCLUSION</b>The cell-penetrating peptide myr-RKEFAK causes an inhibitory effect on integrin β3 outside-in signaling-regulated platelets functions, but did not affect inside-out signaling-regulated platelets functions.</p>