OBJECTIVETo investigate the role of NF-κB/survivin signal pathway in the intima hyperplasia of rat carotid balloon injury restenosis model.

METHODSNF-κB siRNA lentivirus vector (titer was 1 × 10⁸ TU/ml) was established. Carotid balloon injury restenosis model was made in 33 SD rats. The rats were divided into 4 groups according to different processing methods, including negative control (NC) group (n = 11), NF-κB siRNA group (n =11), NF-κB siRNA+YM155 (survivin inhibitor) (n = 11), the uninjured carotid artery served as the normal control group (n = 11). After 7 days, the carotid sample (n = 5 each group) were harvested to detect the NF-κB and survivin mRNA expression by RT-PCR.The carotid sample were harvested on 28 days (n = 6 each group) for HE staining and measuring intima hyperplasia. Immunohistochemical method was also used to detect the expression of intima proliferation cell nuclear antigen (PCNA) and media α-SM-actin.

RESULTS(1) After 7 days, NF-κB and survivin mRNA expression was significant higher in NC group than in normal control group (P<0.05), the NF-κB mRNA expression was significantly lower in NF-κB siRNA group than in NC group (P<0.05) and similar between NF-κB siRNA group and NF-κB siRNA+YM155 group. The survivin mRNA expression was significantly lower in NF-κB siRNA group compared to NC group (P<0.05) and significantly higher in NF-κB siRNA group than in NF-κB siRNA+YM155 group (P<0.05). (2) After 28 days, intima hyperplasia was observed in NC (0.13 ± 0.01), NF-κB siRNA (0.11 ± 0.01) and NF-κB siRNA+YM155 group (0.09 ± 0.01) mm² (P<0.05). Media area was similar among NC group, NF-κB siRNA group and NF-κB siRNA+YM155 group (P>0.05). I/M ratio was gradually reduced among NC group (1.55 ± 0.07), NF-κB siRNA group (0.92 ± 0.08), NF-κB siRNA+YM155 group (0.76 ± 0.06, all P<0.05). Similar results were found in the residual restenosis rate: NC group (58.71 ± 0.02) %, NF-κB siRNA group (32.13 ± 0.05) %, NF-κB siRNA+YM155 group (26.42 ± 0.03) % (all P<0.05) and expression of vascular smooth muscle cell PCNA: NC group (45.32 ± 7.21) %, NF-κB siRNA group (36.54 ± 6.42) %, NF-κB siRNA+YM155 group (28.57 ± 6.31) % (all P<0.05). On the contrary, the IOD of α-SM-actin in media increased gradually: NC group (0.055 ± 0.006), NF-κB siRNA group (0.072 ± 0.011), NF-κB siRNA+YM155 group (0.084 ± 0.008, all P<0.05).

CONCLUSIONInhibiting NF-κB expression can significant decrease intima hyperplasia in this model, and this effect may be mediated by inhibiting survivin and reducing the proliferation of vascular smooth muscle cells.