Two-Stage Interpretation of Changes in TEER of Intestinal Epithelial Layers Protected by Adhering Bifidobacteria During E. coli Challenges

作者：Lu Yuan, Henny C. van der Mei, Henk J. Busscher, B.W. Peterson · 发表于：Frontiers in Microbiology · 年份：2020 · DOI：10.3389/fmicb.2020.599555 · 被引用次数：168 · 研究领域：Gut microbiota and health、Barrier Structure and Function Studies、Probiotics and Fermented Foods

Mechanisms of gastrointestinal protection by probiotic bacteria against infection involve amongst others, modulation of intestinal epithelial barrier function. Trans-epithelial electrical resistance (TEER) is widely used to evaluate cellular barrier functions. Here, we developed a two-stage interpretative model of the time-dependence of the TEER of epithelial layers grown in a transwell during Escherichia coli challenges in the absence or presence of adhering bifidobacteria. E. coli adhesion in absence or presence of adhering bifidobacteria was enumerated using selective plating. After 4-8 h, E. coli challenges increased TEER to a maximum due to bacterial adhesion and increased expression of a tight-junction protein (ZO-1), concurrent with a less dense layer structure, that is indicative of mild epithelial layer damage. Before the occurrence of TEER-maxima, decreases in electrical conductance (i.e. the reciprocal TEER) did not relate with para-cellular dextran-permeability but after occurrence of TEER-maxima, dextran-permeability and conductance increased linearly, indicative of more severe epithelial layer damage. Within 24 h after the occurrence of a TEER maximum, TEER decreased to below the level of unchallenged epithelial layers demonstrating microscopically-observable holes and apoptosis. Under probiotic protection by adhering bifidobacteria, TEER-maxima were delayed or decreased in magnitude due to later transition from mild to severe damage, but similar linear relation...