Lactobacillus plantarum ameliorates colonic epithelial barrier dysfunction by modulating the apical junctional complex and PepT1 in IL-10 knockout mice
Lactobacillus plantarum ameliorates colonic epithelial barrier dysfunction by modulating the apical junctional complex and PepT1 in IL-10 knockout mice
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DOI：
10.1152/ajpgi.00196.2010
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发表时间：
2010-12-01
影响因子：
4.5
通讯作者：
Qin, Huan-Long
中科院分区：
文献类型：
--
作者：
Chen, Hong-Qi;Yang, Jun;Qin, Huan-Long
益生菌在炎症性肠病的治疗中是有效的。然而，确切的机制仍然未知。为了确定益生菌植物乳杆菌（LP）是否改善白细胞介素-10敲除（IL-10（-/-））小鼠中存在的结肠上皮屏障功能障碍，IL-10（-/-）和野生型小鼠接受LP或媒介物4周。通过组织学评分和临床表现评估结肠炎，并通过Ussing小室测定肠道细胞旁通透性。通过测量血浆头孢氨苄浓度评价寡肽转运蛋白1（PepT 1）介导的跨上皮转运。免疫荧光和Western印迹法检测根尖连接复合物（AJC）和PepT 1蛋白的表达和分布，逆转录PCR检测其mRNA的表达和分布。在所有IL-10（-/-）小鼠中观察到自发性结肠炎，其中细胞旁通透性增加，连同闭合小带-1、闭合蛋白、密蛋白-1和β-连环蛋白的表达和再分布减少。PepT 1表达增加，伴随着增强的头孢氨苄转运。结肠上皮屏障功能障碍进一步证实增加细菌易位和促炎细胞因子的产生。LP治疗降低了结肠的细胞旁通透性，恢复了AJC蛋白的表达和分布，并部分阻止了PepT 1的表达和头孢氨苄在IL-10（-/-）小鼠中的转运。此外，LP治疗还防止了IL-10（-/-）小鼠的细菌移位和促炎细胞因子的产生。本研究的结果表明，LP治疗可通过调节AJC和PepT 1介导的跨上皮转运来改善IL-10（-/-）小鼠的结肠上皮屏障功能障碍。
Probiotics are efficacious in the treatment of inflammatory bowel disease. However, the precise mechanisms remain unknown. To determine whether probiotic Lactobacillus plantarum (LP) ameliorates colonic epithelial barrier dysfunction present in interleukin-10 knockout (IL-10(-/-)) mice, IL-10(-/-) and wild-type mice received LP or the vehicle for 4 wk. Colitis was assessed by histological scores and clinical manifestation, and gut paracellular permeability was measured by Ussing chamber. Oligopeptide transporter 1 (PepT1)-mediated transepithelial transport was evaluated by measuring the plasma cephalexin concentration. The expression and distribution of apical junctional complex (AJC) proteins and PepT1 were determined by Western blotting and immunofluorescence and their mRNA by reverse transcriptase-PCR. Spontaneous colitis was observed in all IL-10(-/-) mice in which paracellular permeability was increased, in conjunction with decreased expression and redistribution of zonula occludens-1, occludin, claudin-1, and beta-catenin. PepT1 expression was increased, accompanied with an enhanced cephalexin transport. Colonic epithelial barrier dysfunction was further confirmed by increased bacterial translocation and proinflammatory cytokine production. Treatment with LP decreased colonic paracellular permeability with restoration of expression and distribution of AJC proteins and partially prevented PepT1 expression and cephalexin transport in IL-10(-/-) mice. Moreover, treatment with LP also prevented bacterial translocation and proinflammatory cytokine production in IL-10(-/-) mice. Results from this study indicated that treatment with LP may ameliorate colonic epithelial barrier dysfunction in IL-10(-/-) mice, by modulating the AJC- and PepT1-mediated transepithelial transport.