Statins Inhibited the ADP-Stimulated Activation of Integrins alpha v beta5 and alpha v beta3 of Vascular Smooth Muscle Cells

ABSTRACT

BACKGROUND AND OBJECTIVES: Integrins mediate the migration, adhesion and proliferation of vascular smooth muscle cells. Adenosine diphosphate (ADP) can activate vascular integrins. We assessed the hypothesis that 'statins inhibit the ADP-stimulated activation of integrins alpha v beta5 and alpha v beta3 in human aortic smooth muscle cells (HASMC)'. MATERIALS AND METHODS: The expressions of integrins were analyzed using flow cytometry. The activations of integrins were evaluated using the adhesion assay, with prothrombin as an activation-dependent ligand. The MTT assay was used to evaluate the proliferation. RESULTS: Statins did not suppress the expressions of the integrins, alpha v beta5 and alpha v beta3. The ADP-stimulated adhesion was partially prevented by LM609, which blocked integrin alpha v beta3 (13% inhibition), and markedly prevented by P1F5, which blocked integrin alpha v beta5 (76% inhibition; n=5, p<0.05). However, the proliferation was inhibited by c7E3 and LM609, but not by P1F5. Statins inhibited the ADP-stimulated adhesions in a dose-dependent manner after 15 min of pretreatment. After incubating HASMC with statins for 1 day, simvastatin and fluvastatin inhibited the adhesion by 70 and 66%, respectively (n=5, p<0.05 vs. no statin). Statins also inhibited the ADP-stimulated proliferation of HASMC. CONCLUSION: Statins did not suppress the expressions of the integrins, alpha v beta5 and alpha v beta3, but did inhibit the ADP-stimulated activation of the integrins of HASMC.