S-腺苷蛋氨酸对内毒素性肝损害保护作用的研究

发布时间：2018-03-04 02:28

本文选题：S-腺苷蛋氨酸　切入点：内毒素　出处：《重庆医科大学》2010年硕士论文　论文类型：学位论文

【摘要】： 目的通过建立内毒素性肝损害的动物模型,观察S-腺苷蛋氨酸(S-adenosylmethionine, SAM)预处理对脂多糖(Lipopolysaccharide, LPS)作用下小鼠肝脏的肝X受体(Liver X receptors, LXR)α和Toll样受体4(Toll like receptor 4, TLR4)以及炎症通路中重要的下游促炎细胞因子肿瘤坏死因子α(TNF-α)和抑炎细胞因子白细胞介素10(IL-10)表达的影响,探讨SAM减轻LPS作用下肝脏的损伤和其作用相关的可能机制。方法实验小鼠随机均分为三组,NS组:腹腔注射等体积生理盐水,LPS组:腹腔注射剂量为10mg/kg的LPS,SAM组:腹腔注入10mg/kg的LPS前2h于小鼠腹腔内注射100mg/kg的SAM。记录三组小鼠120h存活率;光镜和电镜观察组织病理学改变;酶联免疫吸附法(ELISA)检测血清中TNF-α和IL-10的浓度;免疫组织化学法(SABC)和蛋白免疫印迹法(Western blot)检测肝组织中TLR4和LXRα的蛋白表达水平;按数据类型进行统计学分析。结果S-腺苷蛋氨酸能明显提高小鼠存活率,SAM组为50.0%,LPS组为30.0%,差异有统计学意义(P0.05);光镜和电镜观察比较小鼠肝脏组织病理损害程度,SAM有效的减轻了内毒素性肝损害;SAM组血清中TNF-α水平( 718.83±53.27 ) pg/ml显著低于LPS组(1791.79±122.19)pg/ml,差异有统计学意义(P0.05);SAM组血清中IL-10(418.69±38.77)pg/ml增加且高峰前移,与LPS组(347.09±31.37)pg/ml比较差异有统计学意义(P0.05);免疫组织化学法(SABC)观察和蛋白免疫印迹法(Western blot)检测,SAM组肝组织中LXRα(1.605±0.027)表达明显增加,而TLR4(1.365±0.017)表达则明显减少,两者与LPS组LXRα(1.375±0.014)和TLR4(1.550±0.034)比较差异均有统计学意(P0.05)。结论SAM能明显减轻LPS所致的肝损害,其机制可能与其降低肝脏各种细胞TLR4的表达,增强LXRα的表达,最终导致TNF-α水平降低和IL-10水平增高有关。
[Abstract]:Objective to establish an animal model of liver injury induced by endotoxin. The effects of S-adenosylmethionine (SAM) preconditioning on lipopolysaccharide (LPSs) induced by lipopolysaccharide in lipopolysaccharide (LPSs) induced by lipopolysaccharide in lipopolysaccharide (lipopolysaccharide) in lipopolysaccharide (lipopolysaccharide) in lipopolysaccharide (LPSs) in lipopolysaccharide (lipopolysaccharide) were observed in mice liver X receptor (LXR) 伪 and Toll like receptor 4 Toll like receptor 4 (TLR4), as well as the important downstream inflammatory cytokine TNF- 伪 in inflammatory pathway. And the expression of interleukin-10 (IL-10), an anti-inflammatory cytokine, To investigate the possible mechanism of SAM in alleviating liver injury induced by LPS. Methods the experimental mice were randomly divided into three groups: intraperitoneal injection of normal saline LPS group: 10 mg / kg LPS-1 SAM group: 10 mg / kg LPS 2 hours before intraperitoneal injection of 100 mg / kg SAM. The 120h survival rate of the three groups was recorded. The histopathological changes were observed by light and electron microscopy, the concentrations of TNF- 伪 and IL-10 in serum were detected by Elisa, the protein expression of TLR4 and LXR 伪 in liver tissue was detected by immunohistochemistry and Western blot. Statistical analysis was carried out according to data type. Results S- adenosine methionine could significantly improve the survival rate of mice. The survival rate of SAM group was 50. 0 and that of LPS group was 30. 0, the difference was statistically significant (P 0. 05). The pathological damage degree of liver tissue in mice was observed by light microscope and electron microscope. The level of TNF- 伪 in serum of SAM group (718.83 卤53.27 ng / ml) was significantly lower than that of LPS group (1791.79 卤122.19 ng / ml). The difference was statistically significant. The serum TNF- 伪 level of SAM group increased and the peak peak moved forward. Compared with LPS group (347.09 卤31.37 g / ml), the expression of LXR 伪 _ (1.605 卤0.027) in liver tissue was significantly increased by immunohistochemistry and the expression of LXR _ 伪 _ (1.605 卤0.027) was decreased by Western blotanalysis, while the expression of LXR 伪 _ (1.605 卤0.027) was significantly decreased in LPS group, while the expression of LXR _ 伪 _ (1.605 卤0.027) was significantly decreased by immunohistochemistry and Western blotting. There were significant differences between the two groups in terms of LXR 伪 (1.375 卤0.014) and TLR4(1.550 卤0.034 (P 0.05). Conclusion SAM can attenuate the liver damage induced by LPS, and its mechanism may be related to the decrease of TLR4 expression and the enhancement of LXR 伪 expression in various liver cells, which leads to the decrease of TNF- 伪 level and the increase of IL-10 level.
【学位授予单位】：重庆医科大学
【学位级别】：硕士
【学位授予年份】：2010
【分类号】：R363

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