OBJECTIVE: To investigate the expression of mDia1 (mammalian diaphanous 1)in platelet and the role of mDia1 or phosphatidylinositol 3-kinase (PI3K) in the process of thrombin-induced platelet aggregation. METHODS: The extent of platelet aggregation was measured by a platelet aggregation system and the expression of mDia1 and its relation with F-actin in quiescent, spreading or aggregated platelets by Western blot. RESULTS: There was no significant difference in mDia1 expression level between quiescent and activated platelets. mDia1 moved from a Triton-X100-soluble cytosolic fraction to insoluble cytoskeleton fraction after thrombin induced platelets aggregation. Anti-mDia1 antibody could inhibit this aggregation. PI3K inhibitor Wortmannin or Ly294002 inhibited the thrombin induced platelet aggregation and the above mentioned mDia1 translocation. CONCLUSION: PI3-kinase mediates the thrombin-induced platelet aggregation through mDia1 pathway.
OBJECTIVE: To investigate the expression of mDia1 (mammalian diaphanous 1)in platelet and the role of mDia1 or phosphatidylinositol 3-kinase (PI3K) in the process of thrombin-induced platelet aggregation. METHODS: The extent of platelet aggregation was measured by a platelet aggregation system and the expression of mDia1 and its relation with F-actin in quiescent, spreading or aggregated platelets by Western blot. RESULTS: There was no significant difference in mDia1 expression level between quiescent and activated platelets. mDia1 moved from a Triton-X100-soluble cytosolic fraction to insoluble cytoskeleton fraction after thrombin induced platelets aggregation. Anti-mDia1 antibody could inhibit this aggregation. PI3K inhibitor Wortmannin or Ly294002 inhibited the thrombin induced platelet aggregation and the above mentioned mDia1 translocation. CONCLUSION: PI3-kinase mediates the thrombin-induced platelet aggregation through mDia1 pathway.