School of Women's and Children's Health, University of New South Wales, Randwick, Sydney, NSW, Australia.
J Gastroenterol. 2012 Feb;47(2):107-17. doi: 10.1007/s00535-011-0471-1. Epub 2011 Sep 28.
Diminished intestinal epithelial barrier function contributes to the pathogenesis of Crohn's disease. Clinical and experimental studies propose that increased tumor necrosis factor (TNF)-α promotes barrier dysfunction. The aim of this study was to investigate the effects of nutritional and other therapies upon intestinal barrier function in the presence of TNF-α in an in vitro model.
Caco-2 monolayers were grown to confluence on membrane supports and then exposed to TNF-α in the presence of polymeric formula, hydrocortisone or infliximab. Monolayer permeability was evaluated by measuring epithelial resistance, short-circuit current and horseradish peroxidase flux in an Ussing chamber. Tight junction and myosin II regulatory light-chain kinase gene expression was analysed by real-time PCR, with protein expression and localization analysed by Western blot and immunofluorescence.
TNF-α increased monolayer permeability and diminished tight junction integrity. However both polymeric formula and infliximab completely abrogated the effects of TNF-α. These monolayers displayed unchanged permeability and tight junction integrity compared to untreated cells (media-no-TNF-α controls). In contrast, hydrocortisone only partially abrogated the effects of TNF-α, with these monolayers having increased permeability and altered tight junction integrity compared to media-no-TNF-α controls.
Both polymeric formula and infliximab completely prevent epithelial barrier dysfunction in the presence of TNF-α, whereas hydrocortisone partially prevents barrier dysfunction. These results provide evidence that superior mucosal healing can be achieved with both polymeric formula and infliximab compared to hydrocortisone.
肠道上皮屏障功能降低是导致克罗恩病发病的原因之一。临床和实验研究表明，肿瘤坏死因子（TNF）-α的增加会促进屏障功能障碍。本研究旨在探讨在体外模型中存在 TNF-α的情况下，营养和其他治疗方法对肠道屏障功能的影响。
将 Caco-2 单层细胞培养在膜支持物上，然后在存在聚合配方、氢化可的松或英夫利昔单抗的情况下暴露于 TNF-α。通过在 Ussing 室中测量上皮电阻、短路电流和辣根过氧化物酶通量来评估单层通透性。通过实时 PCR 分析紧密连接和肌球蛋白 II 调节轻链激酶基因表达，通过 Western blot 和免疫荧光分析蛋白质表达和定位。
TNF-α增加了单层通透性并破坏了紧密连接的完整性。然而，聚合配方和英夫利昔单抗完全消除了 TNF-α的作用。与未经处理的细胞（无 TNF-α 培养基对照）相比，这些单层的通透性和紧密连接完整性没有变化。相比之下，氢化可的松仅部分消除了 TNF-α的作用，这些单层的通透性增加，紧密连接完整性发生改变，与无 TNF-α 培养基对照相比。
聚合配方和英夫利昔单抗均可完全预防 TNF-α存在时的上皮屏障功能障碍，而氢化可的松则部分预防屏障功能障碍。这些结果为与氢化可的松相比，聚合配方和英夫利昔单抗可实现更好的黏膜愈合提供了证据。
