Anion Transport in EPEC Induced Diarrhea

描述（由申请人提供）： 目前的申请旨在为主要研究者提供宿主-微生物相互作用领域的深入培训，沿着研究生水平的正式课程，以提高她的研究和实验室技能。申办者和共同申办者的专业知识与芝加哥伊利诺伊大学医学系高度互动的基础研究环境相结合，为主要研究者提供了一个很好的培训机会，以实现其成为宿主-微生物相互作用领域独立研究者的长期目标。本研究旨在探讨阴离子转运在重要食源性致病菌肠致病性大肠杆菌感染相关腹泻的病理生理学中的作用。coli（EPEC）。迄今为止，EPEC相关腹泻的潜在机制尚不清楚。腹泻是由于分泌增加或吸收减少或两者兼而有之。早期的研究未能最终表明EPEC感染引起宿主分泌反应的增加。我们推测EPEC引起的腹泻可能涉及肠道离子吸收过程的减少。我们的初步数据表明，CI '-OH'交换活性，丁酸盐转运和Na+吸收亚型，NHE 3响应EPEC感染下降。本研究将在体外和体内模型中探索EPEC感染对Cl '-OH'交换活性的影响，并阐明管腔阴离子交换剂，EPEC（SLC 26 A3）和PAT-1（SLC 26 A6）的贡献。具体目标1中的研究将确定EPEC对模型人小肠（Caco-2）和结肠（T84和非转化的NCM 460）上皮细胞中Cl'转运的影响;沿着阐明信号传导机制、EPEC毒力基因的作用和EPEC介导的Cl'转运影响的动力学参数。具体目标2将利用siRNA技术来确定EPEC和PAT-1在响应于EPEC感染的CI '-OH'交换的调节中的作用。具体目标3将利用EPEC感染的体内鼠模型严格地检查EPEC对回肠和结肠中Cl '转运的影响。这些研究结果不仅将增加我们对人肠道Cl '-OH'交换体的调节机制以及致病微生物对它们的调节的理解，而且将为EPEC诱导的腹泻的发病机制提供依据，这可能有助于未来改进治疗方式的发展。

DESCRIPTION (provided by applicant): The current application is aimed at providing the Principal Investigator with in-depth training in the area of host-microbial interactions along with formal courses at the graduate level to enhance her research and laboratory skills. The expertise of the sponsor and co-sponsor combined with a highly interactive basic-research environment at the Department of Medicine at University of Illinois at Chicago, offer a great training opportunity for the Principal Investigator to achieve her long-term goals in becoming an independent research investigator in the area of host- microbial interactions. The proposed studies are focused to examine the role of anion transport in the pathophysiology of diarrhea associated with infection by an important food-borne pathogen, Enteropathogenic E. coli (EPEC). To date, the mechanism(s) underlying EPEC associated diarrhea are not clear. Diarrhea results from increased secretion or decreased absorption or both. Earlier studies have failed to conclusively show an increase in host secretory responses by EPEC infection. We hypothesized that EPEC-induced diarrhea might involve a decrease in intestinal ion absorptive processes. Our preliminary data showed a decrease in CI'-OH' exchange activity, butyrate transport and Na+ absorbing isoform, NHE3 in response to EPEC infection. The present studies will explore the effects of EPEC infection on Cl'-OH' exchange activity in both in vitro and in vivo models and elucidate the contribution of luminal anion exchangers, DRA (SLC26A3) and PAT-1 (SLC26A6). Studies in Specific Aim 1 will determine the effects of EPEC on Cl' transport in model human small intestinal (Caco-2) and colonic (T84 and non-transformed NCM460) epithelia; along with elucidation of signaling mechanism(s), role of EPEC virulence genes and kinetic parameters of EPEC mediated effects on Cl' transport. Specific Aim 2 will utilize siRNA technology to define the role of DRA and PAT-1 in modulation of CI'-OH' exchange in response to EPEC infection. Specific Aim 3 will critically examine the effects of EPEC on CI' transport in ileum and colon utilizing the in vivo murine model of EPEC infection. The results from these studies will not only increase our understanding of the mechanisms of regulation of human intestinal Cl'-OH' exchangers and their modulation by pathogenic organisms, but will also provide basis for the pathogenesis of EPEC-induced diarrhea which might aid in the development of improved therapeutic modalities in future.