低浓度脂多糖加速大鼠颈动脉球囊损伤后新生内膜的形成  

Low-level lipopolysaccharide accelerates neointimal hyperplasia after balloon injury in rats

作　　者：韩雅玲[1] 康建[1] 王效增[1] 张效林[1] 孟子敏[1] 

机构地区：[1]沈阳军区总医院全军心血管病研究所心内科,辽宁沈阳110016

出　　处：《中国病理生理杂志》2005年第5期849-854,共6页Chinese Journal of Pathophysiology

基　　金：国家自然科学基金资助项目(No.30070280)

摘　　要：目的探讨低浓度脂多糖(LPS)刺激机体免疫系统对血管损伤后加速血管新生内膜增生的影响。方法选用健康Wistar大鼠,静脉注入LPS后,行颈动脉球囊损伤术,建立血管内膜损伤模型。采用免疫荧光或组织化学染色观察内膜增生变化。Westernblot分析损伤组织特异性平滑肌细胞标志物和细胞凋亡表达。用ELISA测定血清白介素-1β(IL-1β)含量和流式细胞术分析CD14阳性细胞表达水平。结果每只鼠注入LPS(50ng)后循环血中单核细胞和IL-1β水平显著升高。血管损伤7d后中膜平滑肌细胞增殖,转化为合成表型,新生内膜逐渐形成,随时间延长,内膜增生加速,内膜厚度由(151.2±14.5)μm2增至(173.9±15.3)μm2。免疫荧光染色观察到增殖细胞核抗原及核因子-κB分别定位于新生内膜和外膜。Westernblot分析显示新生内膜形成早期LPS组平滑肌特异性标志蛋白α-肌动蛋白多于对照组,caspase-3表达持续上调,细胞凋亡多于对照组。结论炎症介质LPS刺激全身免疫系统导致血管损伤后新生内膜暂时性增生,表明炎症介质可以加剧血管损伤后再狭窄的形成。AIM: To confirm that the inflammation response after mechanical arterial injury correlates with the neointimal hyperplasia in animal model. METHODS: Male Wistar rats underwent left common carotid balloon angioplasty were injected twice with a bacterial lipopolysaccharide (LPS, 50 ng/rat) before and after surgery. Next, just after neointima formation, the animals were sacrificed for the evaluation by morphometric analysis, histological observation and immunostaining. Western blot was used to investigate the protein expression of several known mediators of apoptosis. RESULTS: Serum interleukin-1 beta levels as a marker of inflammation were increased after LPS treated. Early neotimal lesions were characterized by intimal thickening and the presence of SMCs. Neointima with smooth muscle alpha-actin negative were observed at 7 days after injured. These areas of neointima demonstrated a relatively high proliferation index by proliferating cell nuclear antigen (PCNA) antibody staining, whereas the proliferation index in media was low. Neointimal thickness was significantly increased at 4 weeks after injury in LPS treated animals compared with controls, from (151.2±14.5 to 173.9±15.3) μm2. Activation of caspase-3 was observed, indicating that smooth muscle cells of neointima was associated with apoptosis. Immunofluorescence analysis revealed NF-κB expression located to the adventitia. CONCLUSIONS: Our results indicate that nonspecific stimulation of low-level LPS facilitates neointimal formation and may be an important factor in the restenosis of angioplasty.

关 键 词：肌 平滑 颈动脉损伤 脂多糖类 大鼠 

分 类 号：R363[医药卫生—病理学]