Modulation of Bladder cAMP to combat UTI's

描述（由申请人提供）：尿路感染（uti）是人类最常见的细菌感染之一。尽管进行了适当的抗生素治疗，但尿路感染的复发和持续存在至少部分归因于病原体在膀胱细胞内寻求细胞内避难。1型尿路致病性大肠杆菌（UPEC）占所有尿路感染的80%以上。细菌的毒力与其侵入膀胱浅表上皮并避免在尿液中被清除的能力有关。我们最近发现，在尿路感染的实验模型中，upc进入膀胱浅表上皮细胞的梭状囊泡并藏于其中。值得注意的是，人为提高BECs细胞内cAMP水平可诱导细菌从感染的BECs中排出，并阻碍细菌入侵BECs。可以想象，使用人工cAMP增强剂来减少进入和排出细胞内壁龛中的细菌可能具有治疗价值。在初步实验中，我们通过腹腔注射福斯克林（一种cAMP增强剂），成功地消除了感染upc的小鼠体内的细菌脲。Forskolin（一种草本植物Coleus forskohlii的衍生物）不太可能对人类有毒，因为在亚洲，Coleus forskohlii的提取物已经被用于药用了几个世纪。在美国，随着人们对替代医学的兴趣日益浓厚，使用福斯克林治疗各种疾病的人数正在迅速增加。具体目的是：(i)采用膀胱感染的离体模型，以证明(a)入侵BECs时UPEC对细胞内cAMP水平的依赖，以及(b)用cAMP调节剂操纵感染BECs细菌负荷的能力。（ii）阐明导致细胞内cAMP如何负调节upc入侵BECs的分子事件，以及人为增加cAMP水平如何触发细菌排出。（iii）检查福斯克林治疗作为抗生素治疗的替代或补充的效果。拟议的研究应提供有价值的信息，cAMP作为细菌入侵和驱逐BECs的有效调节剂的作用。

DESCRIPTION (provided by applicant): Urinary tract infections (UTIs) represent one of the most common bacterial infections of humans. Recurrence and persistence of UTIs, in spite of appropriate antibiotic therapry, has been attributed, at least in part, to the pathogen seeking intracellular refuge within bladder cells. Type 1 fimbriated uropathogenic E.coli (UPEC) accounts for over 80% of all UTIs. The virulence of the bacteria is associated with its capacity to invade the superficial bladder epithelium and avoid elimination in the urine. We have recently discovered that during infection in an experimental model of UTI, UPEC were entering and harboring within fusiform vesicles of superficial epithelial cells of the bladder. Remarkably, artificially boosting intracellular levels of cAMP in BECs induced bacterial expulsion from infected BECs, and also impeded bacterial invasion of BECs. Conceivably, use of artificial enhancers of cAMP to reduce entry and to expel bacteria from intracellular niches could be of therapeutic value. In pilot experiments, we have successfully eliminated bacteriurea in UPEC infected mice following intraperitoneal instillation of forskolin, a cAMP booster. Forskolin (a derivative of the plant herb Coleus forskohlii) is unlikely to be toxic to humans considering that Coleus forskohlii extracts have been employed for medicinal purposes for centuries in Asia. In the US, use of forskolin for a variety of ailments is rapidly increasing as interest in alternative medicine has grown. The specific aims are to: (i) Employ an ex vivo model of bladder infection, to demonstrate (a), the dependence of UPEC on intracellular cAMP levels during invasion of BECs and (b), the ability to manipulate bacterial burden in infected BECs with modulators of cAMP. (ii) Elucidate the molecular events leading to how intracellular cAMP negatively modulates UPEC invasion into BECs and how artificially increasing cAMP levels triggers bacterial expulsion.(iii) Examine the efficacy of forskolin treatment as an alternative or complement to antibiotic therapy for UTIs. The proposed studies should provide valuable information on the role of cAMP as a potent modulator of bacterial invasion and expulsion from BECs.