摘要
目的探讨S-腺苷蛋氨酸(S-adenosylmethionine,SAM)对内毒素(lipolmlysaccharide,LPS)性肝损害的保护机制。方法 100只BABL/c小鼠随机数字法均分为2组,LPS组:腹腔注射10mg/kg的LPS;SAM组:在注射10mg/kgLPS前2h于小鼠腹腔内注射100mg/kg SAM。记录两组小鼠存活率;光镜和电镜观察组织病理学改变;酶联免疫吸附法(ELISA)检测血清中肿瘤坏死因子-α(TNF-α)和白细胞介素-10(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Toll样受体4(TLR4)和肝X受体α(LXRα)的蛋白表达水平。结果两组24、48、72、120h存活率比较,SAM组显著高于LPS组[(80.0%、70.0%、60.0%、50.0%)vs(50.0%、40.0%、30.0%、30.0%),P<0.05],肝脏病理损害程度减轻;SAM组血清中TNF-α水平显著低于LPS组,差异有统计学意义[(1791.79±122.19)pg/ml对(718.83±53.27)pg/ml,P<0.05];SAM组血清中IL-10增加且高峰前移,与LPS组比较差异有统计学意义[(418.69±38.77)pg/ml对(347.09±31.37)pg/ml,P<0.05];SAM组肝组织中LXRα表达明显增加,而TLR4表达则明显减少,两者与LPS组比较差异均有统计学意义{Western blot灰度值[TLR4:(1.550±0.034)对(1.365±0.017),LXRα:(1.605±0.027)对(1.375±0.014)],P<0.05}。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。
Objective To study the protective mechanism of S-adenosylmethionine （ SAM） underlying liver injury induced by lipopolysaccharides （ LPS）. Methods One hundred BABL/c mice were randomly divided into LPS group and SAM group. Mice in LPS group were intraperitoneally injected with 10 mg/kg LPS,and the mice in SAM group were injected with 100 mg/kg SAM 2 h before receiving the same dose of LPS. The survival rate of mice in 2 groups was recorded in 24,48,72 and 120 h after LPS injection. Histopathological changes in liver of mice were examined in 0,1,3,6,12 and 24 h after LPS injection. Tumor necrosis factor-α （ TNF-α） and interleukin-10 （ IL-10） levels in serum were measured by ELISA analysis at above time points. Expression of Toll-like receptor 4 （ TLR4） and liver X receptor α （ LXRα） in hepatic tissues was detected by immunohistochemistry and Western blotting. Results SAM increased the survival rate of mice from 50. 0% ,40. 0% ,30. 0% ,and 30. 0% before LPS injection to 80. 0% ,70. 0% ,60. 0% ,and 50. 0% after its injection （ P 0. 05） ,and attenuated the LPS-induced pathologic changes in liver tissue. The serum TNF-α level was significantly lower in SAM group than in LPS group （ 718. 83 ± 53. 27 vs 1791. 79 ± 122. 19 pg/ml,P 0. 05） ,while the serum IL-10 level was significantly higher in SAM group than in LPS group （ 418. 69 ± 38. 77 vs 347. 09 ± 31. 37 pg/ml,P 0. 05） with its peaking shifted to the left. The expression level of LXRα in hepatic tissue was significantly higher while that of TLR4 in hepatic tissue was significantly lower in SAM group than in LPS group （ gray value of Western blotting for TLR4：1. 550 ± 0. 034 vs 1. 365 ± 0. 017,for LXRα：1. 605 ± 0. 027 vs 1. 375 ± 0. 014,P 0. 05）. Conclusion SAM can significantly attenuate LPS-induced liver injury by reducing the expression of TLR4 and increasing the expression of LXRα in liver cells,and thus lead to TNF-α decreased and IL-10 increased.
出处
《第三军医大学学报》
CAS
CSCD
北大核心
2010年第11期1145-1148,共4页
Journal of Third Military Medical University
基金
国家自然科学基金(30772098)~~
