Effects of high mobility group box 1 and nuclear factor κB on neointimal hyperplasia after common carotid artery balloon injury

This study is to investigate the effects of high mobility group box 1 (HMGB-1) and nuclear factor κB (NF-κB) on intimal hyperplasia after carotid artery balloon injury. A total of 28 male SD rats were subjected to balloon catheter injury at left side carotid artery and this side was considered as experimental group. The right side was taken as control group. Common carotid arteries were harvested at 6 h, 3 d, 7 d and 14 d after balloon injury. The intimal thickness and lumen area were analyzed by HE staining and computerized method. HMGB-1 expression was tested by RT-PCR and NF-κB was detected by EMSA. Among the 28 rats, 4 were excluded due to failed modeling or death and the other 24 rats were included for analysis. Carotid endarterectomy, intimal hyperplasia and restenosis were found after balloon injury. Intimal hyperplasia appeared on 3 d and was significant on 14 d after injury. The ratio of intima/media in the experimental group increased significantly compared with the control group (P < 0.05). HMGB-1 was scarcely expressed in control group. It increased 6 h and peaked on 14 d after injury, with significant difference compared with the control group (P < 0.01). Similarly to HMGB-1, NF-κB was rarely expressed in control group, and its level increased since 6 h and peaked on 14 d after injury. Intimal hyperplasia after carotid artery balloon injury was found in rat model and this might be induced by enhanced expression of HMGB-1 and NF-κB.