Secreted bioactive factors from Bifidobacterium infantis enhance epithelial cell barrier function
Secreted bioactive factors from Bifidobacterium infantis enhance epithelial cell barrier function
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DOI：
10.1152/ajpgi.90227.2008
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发表时间：
2008-11-01
影响因子：
4.5
通讯作者：
Madsen, Karen L.
中科院分区：
文献类型：
--
作者：
Ewaschuk, Julia B.;Diaz, Hugo;Madsen, Karen L.
活的益生菌在降低肠道通透性和炎症方面很有效。我们之前已经证明，益生菌在体外释放调节上皮耐药的多肽生物活性因子。本研究的目的是确定婴儿双歧杆菌释放的因子对肠上皮细胞通透性和紧密连接蛋白的影响，并评估这些因子在IL-10缺陷小鼠中是否保持其生物活性。将婴儿条件培养液(BiCM)应用于T84人上皮细胞，加入和不加入肿瘤坏死因子-α和干扰素-γ。检测跨上皮细胞阻力(TER)、紧密连接蛋白[Claudin1、2、3、4、闭锁小带(ZO)-1、闭锁蛋白]和MAPK活性(p38和ERK)。在Ussing小室中评价BiCM对IL-10缺陷小鼠结肠通透性的急性影响。另一组IL-1缺陷小鼠接受BiCM治疗4wk，然后评估肠道组织学损伤、细胞因子水平、上皮通透性和对细菌抗原的免疫反应。在T84细胞中，BiCM使TER增加，Claudin-2减少，ZO-1和occludin表达增加。这与磷酸化ERK水平升高和磷酸化p38水平降低有关。BiCM可阻止肿瘤坏死因子-α和干扰素-γ诱导的TER下降和紧密连接蛋白的重排。抑制ERK可抑制BiCM诱导的TER升高，并减弱对肿瘤坏死因子-α和干扰素-γ的保护作用。口服BiCM显著降低了小鼠的结肠通透性，而长期服用BiCM对IL-10缺乏的小鼠则减轻了炎症，使结肠通透性正常化，并减少了结肠和脾的干扰素-γ的分泌。总之，婴儿芽孢杆菌的多肽生物活性因子在体内保持了它们的生物活性，并在结肠炎动物模型中有效地正常化肠道通透性和改善疾病。BiCM的作用部分是通过改变MAP激酶和紧密连接蛋白来实现的。
Live probiotic bacteria are effective in reducing gut permeability and inflammation. We have previously shown that probiotics release peptide bioactive factors that modulate epithelial resistance in vitro. The objectives of this study were to determine the impact of factors released from Bifidobacteria infantis on intestinal epithelial cell permeability and tight junction proteins and to assess whether these factors retain their bioactivity when administered to IL-10-deficient mice. B. infantis conditioned medium (BiCM) was applied to T84 human epithelial cells in the presence and absence of TNF-alpha and IFN-gamma. Transepithelial resistance (TER), tight junction proteins [claudins 1, 2, 3, and 4, zonula occludens (ZO)-1, and occludin] and MAP kinase activity (p38 and ERK) were examined. Acute effects of BiCM on intestinal permeability were assessed in colons from IL-10-deficient mice in Ussing chambers. A separate group of IL-1-deficient mice was treated with BiCM for 4 wk and then assessed for intestinal histological injury, cytokine levels, epithelial permeability, and immune response to bacterial antigens. In T84 cells, BiCM increased TER, decreased claudin-2, and increased ZO-1 and occludin expression. This was associated with enhanced levels of phospho-ERK and decreased levels of phospho-p38. BiCM prevented TNF-alpha-and IFN-gamma-induced drops in TER and rearrangement of tight junction proteins. Inhibition of ERK prevented the BiCM-induced increase in TER and attenuated the protection from TNF-alpha and IFN-gamma. Oral BiCM administration acutely reduced colonic permeability in mice whereas long-term BiCM treatment in IL-10-deficient mice attenuated inflammation, normalized colonic permeability, and decreased colonic and splenic IFN-gamma secretion. In conclusion, peptide bioactive factors from B. infantis retain their biological activity in vivo and are effective in normalizing gut permeability and improving disease in an animal model of colitis. The effects of BiCM are mediated in part by changes in MAP kinases and tight junction proteins.