Functional modulation of enterocytes by gram-positive and gram-negative microorganisms
Functional modulation of enterocytes by gram-positive and gram-negative microorganisms
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DOI：
10.1152/ajpgi.00341.2003
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发表时间：
2004-04-01
影响因子：
4.5
通讯作者：
Podolsky, DK
中科院分区：
文献类型：
--
作者：
Otte, JM;Podolsky, DK
临床研究表明，所谓的益生菌可能是有效的治疗炎症性肠病。然而，它们与肠表面相互作用的分子机制仍然不确定。在T84和HT-29肠上皮细胞（IEC）中测定了完整益生菌[大肠杆菌Nissle 1917（EcN）;益生菌混合物VSL#3（PM）]、细菌细胞裂解物和条件培养基对跨上皮抗性（TER）、IL-8分泌、粘蛋白基因表达和紧密连接蛋白的影响。此外，还分析了对病原体（都柏林沙门氏菌）诱导的改变的影响。EcN以及碎片和细胞提取物诱导IEC分泌IL-8，而与PM孵育后未观察到这种作用。PM和从PM释放的可溶性蛋白增加TER，防止病原体诱导的TER降低，并且显示稳定紧密连接。PM诱导IEC中粘蛋白的表达，并且这些生物体以及EcN减少S。Dublin诱导的细胞死亡。用PD-98059或SB-203580抑制MAPK可显著降低IL-8合成和粘蛋白表达的变化，并影响TER的调节。由这些生物体释放的益生菌和蛋白质可以通过不同的机制在功能上调节宿主的肠上皮，包括整个生物体与上皮表面接触的竞争以及细胞骨架和屏障功能的稳定和粘蛋白表达的诱导。革兰氏阴性菌和革兰氏阳性菌的激活机制不同，组合使用微生物可能比使用单一菌株更有效。
Clinical studies have suggested that so-called probiotic bacteria may be effective as therapy in inflammatory bowel disease. However, the molecular mechanisms of their interaction with the intestinal surface remain undefined. The influence of whole probiotic bacteria [Escherichia coli Nissle 1917 (EcN); probiotic mixture VSL#3 (PM)], bacterial cell lysates, and conditioned media on transepithelial resistance (TER), IL-8 secretion, mucin gene expression, and tight junction proteins were determined in T84 and HT-29 intestinal epithelial cells (IEC). In addition, effects on pathogen (Salmonella dublin)-induced alterations were analyzed. EcN as well as debris and cell extracts induced IL-8 secretion from IEC, whereas no such effect was observed following incubation with the PM. The PM and soluble protein(s) released from the PM increased TER, prevented pathogen-induced decrease in TER, and were shown to stabilize tight junctions. The PM induced expression of mucins in IEC, and these organisms as well as EcN diminished S. dublin-induced cell death. Inhibition of MAPKs with PD-98059 or SB-203580 significantly decreased alterations in IL-8 synthesis and mucin expression and affected the regulation of TER. Probiotics and protein(s) released by these organisms may functionally modulate the intestinal epithelium of the host by different mechanisms, including the competition of whole organisms for contact with the epithelial surface as well as stabilization of the cytoskeleton and barrier function and the induction of mucin expression. Gram-negative and gram-positive organisms differ in the mechanisms activated, and a combination of organisms might be more effective than the application of a single strain.