摘要
目的改进并稳定脂多糖(LPS)诱导脑微出血(CMBS)动物模型的建立方法,为进一步研究提供稳定成熟的技术手段;探讨神经型一氧化氮合酶(nNOS)在CMBS过程中的作用。方法 40只SD大鼠,随机分成LPS给药组(n=20)和生理盐水对照组(n=20),分别于0 h、12 h和24 h腹腔注射1 mg/ml、3 mg/kg LPS或相同剂量的生理盐水,48 h后行头部MRI扫描,SWI序列显示出血灶;免疫荧光染色显示小胶质细胞标记分子Iba的表达;蛋白印迹法分析nNOS和ZO-1(血脑屏障标记分子)的表达情况。结果 3 mg/kg LPS给药后,MRI显示散在SWI序列点状低信号影,蛋白印迹法及免疫荧光结果显示ZO-1明显减少,Iba及nNOS表达显著增多。结论 LPS可能通过增加全身炎症反应,促进脑内小胶质细胞增殖,增加nNOS的表达,对中枢神经系统血脑屏障产生破坏作用,从而导致微出血的产生。
Objective To improve the method of cerebral microbleeds(CMBS) model induced by lipopolysaccharide(LPS) and investigate the effect of neuronal nitric oxide synthase(nNOS) in CMBS.Methods Animals were classified into two groups:LPS treatment group(n=20) and saline control group(n=20).LPS group were treated with 1 mg/ml,3 mg/kg,LPS or the same dose of saline by intraperitoneal injection on 0 h、12 h and 24 h.After 48 h,head MRI scan,SWI sequence showed microbleeds.Immunofluorescence staining showed that the expression of microglia marker Iba.Western blot analysis the expression of nNOS and ZO-1(molecular markers of the blood brain barrier).Results Administration of 3 mg/kg LPS group appeared point low signal in the SWI sequence.Western blot and immunofluorescence showed that ZO-1 significantly reduced while Iba and nNOS expression increased significantly.Conclusion LPS may increase the systemic inflammatory response,promote the proliferation of microglia in the brain,increase the expression of nNOS,and destroy the blood-brain barrier of the central nervous system,leading to the occurrence of CMBS.
引文
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