摘要
目的 研究非酒精性脂肪性肝病（NAFLD）家兔肠上皮细胞紧密连接、肠道大肠杆菌、肠黏膜Toll样受体4（TLR4）与肿瘤坏死因子α（TNF α）的变化,并分析TNF α与这些因素之间的关系. 方法 14只雄性新西兰家兔随机分成对照组及模型组,对照组给予普通饲料,模型组给予高脂饲料,喂养12周后处死.取回肠组织行电镜检查,观察肠上皮细胞间紧密连接长度及宽度的变化,采静脉血行酶联免疫吸附法检测血清TNF α,免疫组织化学法观察肠黏膜TLR4的定位及表达,实时荧光定量-聚合酶链反应（RT-PCR）检测粪便中大肠杆菌的变化.逐步多元线性回归分析评估血清TNF α与肠腔大肠杆菌数、肠上皮细胞间紧密连接长度、肠黏膜TLR4表达量之间关系. 结果 与对照组相比,模型组家兔肠上皮紧密连接缩短[（0.377±0.045） μm对比（0.518±0.059） μm,t=5.031,P＜0.01]且间隙增宽,肠腔中大肠杆菌数量增多[（54.767±28.467）拷贝/g对比（14.299± 11.400） log10log10拷贝/g,t=-3.492,P＜0.01],肠黏膜TLR4表达升高[0.042±0.014对比0.015±0.01,t=-44.089,P＜0.01],血清TNF α升高[（0.289±0.016）pg/ml对比（0.210±0.013）pg/ml,t=-17.768,P＜0.01].回归分析结果显示,大肠杆菌、肠上皮紧密连接、肠黏膜TLR4与TNF α明显相关（F=17.773,P＜0.01）,拟合优度判定系数R2=0.842;血清TNF α水平与紧密连接呈负相关（标准回归系数=-0.385）,与大肠杆菌和TLR4呈正相关（标准回归系数分别为0.332和0.427）.结论 NAFLD家兔肠道物理屏障、生物屏障及免疫屏障的破坏与TNF α水平关系密切,且免疫屏障对TNF α的影响更为显著.
Objective To explore the variation and association of intestinal epithelial tight junctions,E.coli,and expression of Toll-like receptor-4 （TLR-4） and tumor necrosis factor-alpha （TNFα） in a rabbit model of non-alcoholic fatty liver disease （NAFLD）.Methods Fourteen male New Zealand rabbits were randomly divided into two groups.The control group was given a normal diet,while the NAFLD group was given a high-fat diet.After 12 weeks,the two groups we re sacrificed.Both length and width of the tight junctions of ileum epithelial cells were measured by electroa microscopy.Enzyme-linked immunosorbent assay was used to detect the concentration of TNFα in venous blood serum.Location and expression of TLR-4 were observed by immunohistochemical staining.Copies of E.coli genes were measured by RT-PCR.The relationship between TNFα and tight junctions,TLR-4,and E.coli were respectively analyzed by stepwise multiple linear regression.Results Compared with the control group,the NAFLD group has significantly shortened ileum epithelial fight junctions （t =5.031,P 〈 0.01）,increased copies of E.coli genes （t =-3.492,P 〈 0.01）,and increased ileal expression of TLR-4 （t =-44.089,P 〈 0.01）.A significant increase of TNFα was also observed in the NAFLD group （t =-17.768,P 〈 0.01）.Regression analysis showed that E.coli and intestinal epithelial tight junctions were correlated （standardized beta =-0.385）,and showed a positive correlation between E.coli and TLR-4 （standardized β =0.332 and 0.427）.Conclusion Damage to the intestine as a physical barrier,biological barrier and immune barrier is closely related to TNFα expression,and the relation between the immune barrier and TNFα is more significant.
出处
《中华肝脏病杂志》
CAS
CSCD
北大核心
2014年第12期942-947,共6页
Chinese Journal of Hepatology
