Xin Dai, Zong-Shun Lv, Bang-Mao Wang, Lu Zhou
Hepatogastroenterology. 2014 Jan-Feb;61(129):136-40.
BACKGROUND/AIMS: To investigate the expression of tight junction (TJ) proteins including Zonula occludens-1 (ZO-1), occludin and claudin-1 in intestinal epithelial cells in patients with non-alcoholic fatty liver disease (NAFLD) and study its potential association with the pathogenesis of NAFLD.
Twenty-eight NAFLD patients with elevated transaminase, 30 NAFLD patients with normal transaminase and 34 healthy volunteers were enrolled. Their biochemical characters were measured and the expression of ZO-1, occludin and claudin-1 proteins in intestinal epithelial cells was assessed by immunohistochemical analysis and its relationship with transaminase levels was also discussed.
Significant differences were observed on the levels of BMI, TC, TG, FPG, ALT, and AST among the three groups. The levels in NAFLD patients with elevated transaminase were significantly higher than NAFLD patients with normal transaminase and the latter had higher levels than the volunteers. The expression of ZO-1 and occludin were significantly different among the three groups (chi2 = 14.210, p < 0.01; chi2 = 20.543, p < 0.01). The expression of ZO-1 and occludin decreased gradually from NAFLD with elevated transaminase to healthy volunteers (r = 0.386, p <0.01; r = 0.449, p < 0.01). In NAFLD patients, the levels of the expression of ZO-1 and occludin were negatively correlated with the transaminase level (r = -0.426, p < 0.01; r = -0.597, p < 0.01). The expression of claudin-1 was found among all the three groups but no statistical significance was observed among three groups (chi2 = 0.686, p = 0.953).
The expression of TJ proteins in intestinal epithelial cells are closely related with the occurrence and development of NAFLD. The contribution of different TJ protein varies in maintaining barrier function.
背景/目的：研究非酒精性脂肪性肝病（NAFLD）患者肠上皮细胞中紧密连接（TJ）蛋白，包括闭合蛋白-1（ZO-1）、闭合蛋白和Claudin-1的表达情况，并探讨其与NAFLD发病机制的潜在关联。
纳入28例转氨酶升高的NAFLD患者、30例转氨酶正常的NAFLD患者和34名健康志愿者。检测他们的生化指标，采用免疫组化分析评估肠上皮细胞中ZO-1、闭合蛋白和Claudin-1蛋白的表达，并探讨其与转氨酶水平的关系。
三组患者在体重指数（BMI）、总胆固醇（TC）、甘油三酯（TG）、空腹血糖（FPG）、谷丙转氨酶（ALT）和谷草转氨酶（AST）水平上存在显著差异。转氨酶升高的NAFLD患者的各项指标水平显著高于转氨酶正常的NAFLD患者，而后者又高于志愿者。三组患者中ZO-1和闭合蛋白的表达存在显著差异（χ² = 14.210，p < 0.01；χ² = 20.543，p < 0.01）。从转氨酶升高的NAFLD患者到健康志愿者，ZO-1和闭合蛋白的表达逐渐降低（r = 0.386，p <0.01；r = 0.449，p < 0.01）。在NAFLD患者中，ZO-1和闭合蛋白的表达水平与转氨酶水平呈负相关（r = -0.426，p < 0.01；r = -0.597，p < 0.01）。三组患者中均检测到Claudin-1的表达，但三组间无统计学差异（χ² = 0.686，p = 0.953）。
肠上皮细胞中TJ蛋白的表达与NAFLD的发生发展密切相关。不同TJ蛋白在维持屏障功能中的作用各不相同。
