Components of intestinal epithelial hypoxia activate the virulence circuitry of Pseudomonas
Components of intestinal epithelial hypoxia activate the virulence circuitry of Pseudomonas
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DOI：
10.1152/ajpgi.00241.2004
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发表时间：
2005-05-01
影响因子：
4.5
通讯作者：
Alverdy, JC
中科院分区：
文献类型：
--
作者：
Kohler, JE;Zaborina, O;Alverdy, JC
我们以前已经表明，铜绿假单胞菌的致命毒力性状，PA-I凝集素，是由手术应激小鼠肠腔内的细菌表达。本研究的目的是确定是否肠上皮缺氧，手术应激的常见反应，可以激活PA-I的表达。产生融合构建体以表达PA-1基因下游的绿色荧光蛋白，用作铜绿假单胞菌中PA-1表达的稳定报告菌株。将极化的Caco-2单层暴露于环境缺氧（0.1- 0.3%O-2）1 h，有或没有正常氧（21%O-2）恢复期2 h，然后接种含有PA-1报告基因构建体的铜绿假单胞菌。低氧Caco-2单层引起PA-I启动子活性相对于常氧单层显著增加（1h时165%; P < 0.001）。类似的激活PA-I也诱导无细胞的顶端，但不是基础，缺氧Caco-2单层的媒体。PA-Ⅰ启动子的激活优先增强与缺氧上皮细胞的物理相互作用的细菌细胞。我们的结论是，铜绿假单胞菌的毒力电路激活的可溶性和接触介导的元素的肠上皮细胞在缺氧和常氧恢复。
We have previously shown that a lethal virulence trait in Pseudomonas aeruginosa, the PA-I lectin, is expressed by bacteria within the intestinal lumen of surgically stressed mice. The aim of this study was to determine whether intestinal epithelial hypoxia, a common response to surgical stress, could activate PA-I expression. A fusion construct was generated to express green fluorescent protein downstream of the PA-I gene, serving as a stable reporter strain for PA-I expression in P. aeruginosa. Polarized Caco-2 monolayers were exposed to ambient hypoxia (0.1-0.3% O-2) for 1 h, with or without a recovery period of normoxia (21% O-2) for 2 h, and then inoculated with P. aeruginosa containing the PA-I reporter construct. Hypoxic Caco-2 monolayers caused a significant increase in PA-I promoter activity relative to normoxic monolayers (165% at 1 h; P < 0.001). Similar activation of PA-I was also induced by cell-free apical, but not basal, media from hypoxic Caco-2 monolayers. PA-I promoter activation was preferentially enhanced in bacterial cells that physically interacted with hypoxic epithelia. We conclude that the virulence circuitry of P. aeruginosa is activated by both soluble and contact-mediated elements of the intestinal epithelium during hypoxia and normoxic recovery.