Division of Gastroenterology and Nutrition, Department of Paediatrics, Mackay Memorial Hospital, Taipei 10449, Taiwan ; Mackay Medicine, Nursing and Management College, Taipei 25245, Taiwan ; Institute of Biotechnology and Department of Chemical Engineering, National Taipei University of Technology, No. 1, Sec. 3, Chung-Hsiao East Road, Taipei 10608, Taiwan ; Department of Medicine, Mackay Medical College, Taipei 25246, Taiwan.
Gastroenterol Res Pract. 2013;2013:973209. doi: 10.1155/2013/973209. Epub 2013 Jun 6.
Background. Lactobacillus shows beneficial anti-inflammatory effects on Salmonella infection. The maintenance of the tight junction (TJ) integrity plays an importance role in avoiding bacterial invasion. Whether Lactobacillus could be used to regulate the TJ protein expression and distribution in inflamed intestinal epithelial cells was determined. Methods. Using the transwell coculture model, Salmonella lipopolysaccharide (LPS) was apically added to polarized Caco-2 cells cocultured with peripheral blood mononuclear cells in the basolateral compartment. LPS-stimulated Caco-2 cells were incubated with various Lactobacillus strains. TJ integrity was determined by measuring transepithelial electrical resistance across Caco-2 monolayer. Expression and localization of TJ proteins (zonula-occludens- (ZO-) 1) were determined by Western blot and immunofluorescence microscopy. Results. Various strains of Lactobacillus were responsible for the different modulations of cell layer integrity. LPS was specifically able to disrupt epithelial barrier and change the location of ZO-1. Our data demonstrate that Lactobacillus could attenuate the barrier disruption of intestinal epithelial cells caused by Salmonella LPS administration. We showed that Lactobacillus strains are associated with the maintenance of the tight junction integrity and appearance. Conclusion. In this study we provide insight that live probiotics could improve epithelial barrier properties and this may explain the potential mechanism behind their beneficial effect in vivo.
乳酸杆菌对沙门氏菌感染具有有益的抗炎作用。紧密连接（TJ）的完整性维持对于避免细菌入侵起着重要作用。确定乳酸杆菌是否可用于调节炎症性肠上皮细胞中的 TJ 蛋白表达和分布。
使用 Transwell 共培养模型，将沙门氏菌脂多糖（LPS）添加到与外周血单核细胞共培养的极化 Caco-2 细胞的顶端，在基底外侧隔室中。用各种乳酸杆菌菌株孵育 LPS 刺激的 Caco-2 细胞。通过测量 Caco-2 单层的跨上皮电阻来确定 TJ 完整性。通过 Western blot 和免疫荧光显微镜确定 TJ 蛋白（闭合蛋白-1（ZO-1））的表达和定位。
各种乳酸杆菌菌株负责不同程度地调节细胞层的完整性。LPS 专门能够破坏上皮屏障并改变 ZO-1 的位置。我们的数据表明，乳酸杆菌能够减轻沙门氏菌 LPS 给药引起的肠上皮细胞屏障破坏。我们表明，乳酸杆菌菌株与紧密连接完整性和外观的维持有关。
在这项研究中，我们提供了深入的了解，即活益生菌可以改善上皮屏障特性，这可能解释了它们在体内有益作用的潜在机制。
