CpxRA是在肠杆菌科中高度保守的包膜应激反应系统。CpxA对CpxR具有激酶活性,对磷酸-CpxR(CpxR-P)具有磷酸酶活性,转录因子.响应膜应力,CpxR-P产生并上调参与膜修复的基因,并下调编码跨细胞膜运输的毒力因子的基因。在小鼠模型中,减毒沙门氏菌和泌尿致病性大肠杆菌(UPEC)中组成型激活CpxRA的突变体。我们假设CpxR的药理激活可以作为抗微生物/抗毒力策略,最近表明2,3,4,9-四氢-1H-咔唑-1-胺通过抑制CpxA磷酸酶活性激活CpxRA系统。这里,我们在小鼠尿路感染模型中测试了一系列具有增加效力的三种CpxRA活化化合物清除UPEC染色CFT073的能力。我们表明,这些化合物具有良好的耐受性,并达到足够的水平来激活肾脏中的CpxR,膀胱,还有尿液.尽管前两种化合物在小鼠模型中对促进CFT073的清除无效,最有效的衍生物,化合物26,显着减少尿液中的细菌回收,并倾向于减少膀胱和肾脏中的细菌回收,与环丙沙星的功效相似。用化合物26处理在人尿中培养的CFT073促进了CpxR-P的积累,并降低了参与铁载体生物合成和结合的蛋白质的表达,血红素降解,和鞭毛运动。这些研究表明,CpxRA的化学活化可能是治疗UPEC感染的可行策略。重要性由于对抗生素具有耐药性的泌尿致病性大肠杆菌(UPEC),尿路感染(UTI)的患病率不断增加是一个主要的公共卫生问题。细菌含有感知其环境的蛋白质,并且没有人类同源物,因此,是有吸引力的药物靶标。CpxRA是一种保守的传感系统,其功能是减少细菌细胞膜中的应激;CpxRA的激活降低了毒力决定子的表达,它必须穿过细胞膜到达细菌表面。我们先前鉴定了一类激活CpxRA的化合物。我们在小鼠UTI模型中显示,我们最有效的化合物显着降低了尿液中UPEC的回收率,倾向于减少膀胱和肾脏中的细菌恢复,没有杀死UPEC,并下调参与UPEC毒力的多种蛋白质。由于这些化合物不是通过杀伤机制起作用的,它们有可能治疗由抗生素抗性细菌引起的UTI。
CpxRA is an envelope stress response system that is highly conserved in the Enterobacteriaceae. CpxA has kinase activity for CpxR and phosphatase activity for phospho-CpxR (CpxR-P), a transcription factor. In response to membrane stress, CpxR-P is produced and upregulates genes involved in membrane repair and downregulates genes that encode virulence factors that are trafficked across the cell membrane. Mutants that constitutively activate CpxRA in Salmonella enterica serovar Typhimurium and in uropathogenic Escherichia coli (UPEC) are attenuated in murine models. We hypothesized that pharmacologic activation of CpxR could serve as an antimicrobial/antivirulence strategy and recently showed that 2,3,4,9-tetrahydro-1H-carbazol-1-amines activate the CpxRA system by inhibiting CpxA phosphatase activity. Here, we tested the ability of a series of three CpxRA-activating compounds with increasing potency to clear UPEC stain CFT073 in a murine urinary tract infection model. We show that these compounds are well tolerated and achieve sufficient levels to activate CpxR in the kidneys, bladder, and urine. Although the first two compounds were ineffective in promoting clearance of CFT073 in the murine model, the most potent derivative, compound 26, significantly reduced bacterial recovery in the urine and trended toward reducing bacterial recovery in the bladder and kidneys, with efficacy similar to ciprofloxacin. Treatment of CFT073 cultured in human urine with compound 26 fostered accumulation of CpxR-P and decreased the expression of proteins involved in siderophore biosynthesis and binding, heme degradation, and flagellar movement. These studies suggest that chemical activation of CpxRA may present a viable strategy for treating infections due to UPEC. IMPORTANCE The increasing prevalence of urinary tract infections (UTIs) due to antibiotic-resistant uropathogenic Escherichia coli (UPEC) is a major public health concern. Bacteria contain proteins that sense their environment and have no human homologs and, thus, are attractive drug targets. CpxRA is a conserved sensing system whose function is to reduce stress in the bacterial cell membrane; activation of CpxRA reduces the expression of virulence determinants, which must cross the cell membrane to reach the bacterial surface. We previously identified a class of compounds that activate CpxRA. We show in a mouse UTI model that our most potent compound significantly reduced recovery of UPEC in the urine, trended toward reducing bacterial recovery in the bladder and kidneys, did not kill UPEC, and downregulated multiple proteins involved in UPEC virulence. Since these compounds do not act by a killing mechanism, they have potential to treat UTIs caused by antibiotic-resistant bacteria.