Palumbo Paola, Lombardi Francesca, Cifone Maria Grazia, Cinque Benedetta
Department of Life, Health & Environmental Sciences, University of L'Aquila - Building Delta 6, Coppito, L'Aquila, Italy.
Endocr Metab Immune Disord Drug Targets. 2019;19(2):199-206. doi: 10.2174/1871530318666181022164505.
VSL#3 has been extensively investigated and is currently recommended for the prevention and treatment of chronic pouchitis and ulcerative colitis. Nonetheless, in vitro and in vivo studies have recently shown variability in the VSL#3 efficacy often attributed to the manufacturing process.
The aim was to comparatively study the in vitro effects of two VSL#3 preparations produced in different sites (named US- and Italy-made VSL#3) on CaCo-2 epithelial barrier model in terms of trans-epithelial electrical resistance (TEER), dextran flux and expression of Tight Junctions (TJ) proteins i.e. zonulin-1 (ZO-1) and occludin, in the absence or presence of a heat stress-related damage of monolayer.
TEER was evaluated on CaCo-2 differentiated monolayers. Epithelial permeability of polarized monolayers was assessed by measuring the FITC-labeled dextran flux from the apical to basolateral chambers. ZO-1/occludin levels were analyzed by western blot analysis. A set of experiments was performed to compare the effects of both VSL#3 on TEER values, dextran flux and ZO-1/occludin expression in CaCo-2 monolayers after heat stress exposure.
US- and Italy-made VSL#3 have opposing effects on TEER values, dextran flux, and ZO- 1/occludin expression, being all these parameters negatively influenced just by Italy-made product. US-made probiotic did not affect baseline TEER, dextran flux and ZO-1 expression and strongly increased occludin levels. Of note, pre-treatment of monolayer with US-made VSL#3, but not Italy-made product, totally prevented the heat-induced epithelial barrier integrity loss.
Our data trigger the need for reassessing efficacy or safety of the Italy-made VSL#3 considering intestinal epithelial barrier plays an important role in maintaining host health.
VSL#3已得到广泛研究，目前被推荐用于预防和治疗慢性袋炎及溃疡性结肠炎。尽管如此，近期的体外和体内研究表明，VSL#3的疗效存在差异，这通常归因于生产工艺。
旨在比较两种在不同地点生产的VSL#3制剂（分别命名为美国产和意大利产VSL#3）在体外对CaCo-2上皮屏障模型的影响，包括跨上皮电阻（TEER）、葡聚糖通量以及紧密连接（TJ）蛋白即闭合蛋白-1（ZO-1）和闭合蛋白的表达，同时观察单层细胞有无热应激相关损伤的情况。
在CaCo-2分化单层细胞上评估TEER。通过测量FITC标记的葡聚糖从顶侧室到基底侧室的通量来评估极化单层细胞的上皮通透性。通过蛋白质印迹分析来检测ZO-1/闭合蛋白水平。进行了一系列实验，以比较两种VSL#3对热应激暴露后CaCo-2单层细胞的TEER值、葡聚糖通量和ZO-1/闭合蛋白表达的影响。
美国产和意大利产VSL#3对TEER值、葡聚糖通量和ZO-1/闭合蛋白表达有相反的影响，所有这些参数仅受到意大利产产品的负面影响。美国产益生菌不影响基线TEER、葡聚糖通量和ZO-1表达，并显著增加闭合蛋白水平。值得注意的是，用美国产VSL#3预处理单层细胞，而不是意大利产产品，可完全防止热诱导的上皮屏障完整性丧失。
考虑到肠道上皮屏障在维持宿主健康中起重要作用，我们的数据引发了重新评估意大利产VSL#3疗效或安全性的必要性。
