Effects of VCAM-1 siRNA on restenosis following carotid endarterectomy: experiment with rats

To evaluate the inhibitory effects of VCAM-1 siRNA on VCAM-1 protein expression and restenosis following carotid endarterectomy in rats. Lentivirus-based VCAM-1 siRNA was constructed and its efficacy of blocking VCAM-1 protein expression in endothelial cells and carotids was identified by Western blot. Doppler ultrasonography and morphometric analysis were performed to measure the degree of restenosis. VCAM-1 siRNA decreased the protein expression of VCAM-1 in cultured endothelial cells and carotids. Treatment of VCAM-1 siRNA showed a significant reduction in the restenosis and manifested as an increased blood velocity and linear diameter as compared with control siRNA (P < 0.05). Morphometric analysis showed that the ratio of intima to media area (I/M) increased significantly in CEA group (3.99 +/- 0.65) versus sham-operated group (0.35 +/- 0.13) (P < 0.05). Furthermore, VCAM-1 siRNA resulted in an evident decrease in the neointimal area (1.79 +/- 0.43) as compared with that of the control siRNA (4.33 +/- 0.