SM22α Inhibits Neointimal Hyperplasia after Balloon Injury in Rat

Abstract: To observe the effect of SM22α on neointimal hyperplasia after balloon injury and to investigate its mechanism of action， male SD rats were randomly divided into three groups after balloon injury， including uninfected group， pAd group and pAd-SM22α group. All rats were killed after 14d and carotid arteries were removed. Neointima thickening was assessed using HE staining. Western blot and immunohistochemistry were used to detect SM22α， PCNA and p27 expression in the vascular wall. The phosphorylation of Raf-1， MEK1/2 and ERK1/2 was examined by Western blot. The results showed that pAd-SM22α stably expressed SM22α protein in the transfected vascular wall. Overexpression of SM22α significantly inhibited neointimal hyperplasia induced by balloon injury. The expression of PCNA protein in pAd-SM22α group was decreased compared with the control (P<0.05). Meanwhile， the expression of p27 protein in pAd-SM22α group was significantly increased (P<0.05).The phosphorylation of Raf-1， MEK1/2 and ERK1/2 in the pAd-SM22α group was decreased (P<0.05)， with reduction of neointimal hyperplasia. This study suggests that SM22α inhibits neointimal formation after balloon injury in rats via the blockade of Raf-1-MEK1/2-ERK1/2 signaling pathway.

CSTR: 32200.14.cjcb.2010.04.0006