Cellular and Molecular Basis of Sex Specificity in UTI Pathogenesis

项目总结 在这项拟议的工作中，华盛顿大学的亨斯塔德实验室将采用新的尿路模型 雌性、雄激素化雌性和雄性小鼠感染(UTI)以确定其分子机制 宿主雄激素暴露促进尿路致病性大肠埃希氏菌肾盂肾炎和肾脏 疤痕形成，上尿路感染的常见后遗症。我们最近的发现表明，性的影响，包括 雄激素暴露对这些常见细菌感染的影响比以前所认识的要复杂得多。 利用新开发和优化的小鼠尿路感染模型，我们最近证明了雄激素 暴露与慢性膀胱炎和高滴度肾盂肾炎的风险增加以及形成有关。 在男性和女性宿主中都存在肾脓肿。这些发现与流行病学数据相关，揭示了 患有复杂性尿路感染的男性的发病率和死亡率更高(与女性相比)，而且 患有常见高雄激素性疾病(多囊卵巢综合征)的妇女的尿路感染发生率。此外， 我们已经证明了雄激素对肾纤维化(疤痕形成)的单独作用，这是一种常见的 儿童肾盂肾炎可能导致长期后遗症，如高血压和慢性肾炎 肾脏疾病。根据这些发现，我们假设根本的性别差异会影响 肾盂肾炎中宿主-病原体的相互作用和细胞反应，从而影响致病性， 溶解，以及随后的肾脏疤痕。为了验证这一假设，并在我们已发表的工作的基础上， 我们将首先全面定义针对宿主性别的毒力要求和对宿主的性别影响- 通过单核rna-seq、杂交捕获增强型细菌rna-seq和 与MPI Earl博士和MPI合作，对感染的肾脏进行插入位点测序实验 合作者汉弗莱斯博士。候选的性别差异寄主途径和细菌毒力因素将是 使用生殖系和条件基因敲除小鼠、细菌突变体和一系列 细菌致病机理研究。我们还将确定以下肾脏纤维化的分子途径 肾盂肾炎，以及这些通路如何在不同的时间受到性别和/或雄激素暴露的调节 尿路感染前、中、后。总之，拟议的工作将利用新的临床前模型和一系列 传统的和前沿的实验技术。我们的结果将阐明特定性别的寄主病原体 感染肾脏中的相互作用并确定UPEC毒力因子在性别依赖性预后中的重要作用 上尿路感染。此外，我们的临床前研究结果也将与复发性尿路感染和 人类患者群体中的肾脏疤痕。

PROJECT SUMMARY In the proposed work, the Hunstad laboratory at Washington University will employ new models of urinary tract infection (UTI) in female, androgenized female, and male mice to determine molecular mechanisms by which host androgen exposure promotes uropathogenic Escherichia coli (UPEC) pyelonephritis as well as renal scarring, a common sequela of upper-tract UTI. Our recent findings indicate that the influence of sex, including androgen exposure, on these common bacterial infections is more complex than previously appreciated. Using newly developed and optimized models of UTI in mice, we recently demonstrated that androgen exposure is associated with increased risk for chronic cystitis and high-titer pyelonephritis, as well as formation of renal abscesses, in both male and female hosts. These findings correlate with epidemiologic data revealing higher morbidity and mortality in men who do suffer complicated UTI (compared with women), and higher incidence of UTI in women with a common hyperandrogenic condition (polycystic ovary syndrome). Moreover, we have demonstrated a separable effect of androgens on renal fibrosis (scarring), a common complication of pyelonephritis in children that can contribute to long-term sequelae such as hypertension and risk for chronic kidney disease. On the basis of these findings, we hypothesize that fundamental sex differences impact the host-pathogen interaction and cellular responses in pyelonephritis, thereby influencing pathogenicity, resolution, and subsequent renal scarring. To interrogate this hypothesis, and building on our published work, we will first comprehensively define host-sex-specific virulence requirements and sex influences on the host- pathogen interaction through single-nucleus RNA-seq, hybrid capture-enhanced bacterial RNA-seq, and insertion-site sequencing experiments on the infected kidney, in collaboration with MPI Dr. Earl and collaborator Dr. Humphreys. Candidate sex-discrepant host pathways and bacterial virulence factors will be confirmed and interrogated using germline and conditional knockout mice, bacterial mutants, and an array of bacterial pathogenesis studies. We will also define the molecular pathways underlying renal fibrosis following pyelonephritis, and how these pathways are modulated by sex and/or by androgen exposure at varying times before, during, and after UTI. In total, the proposed work will leverage new preclinical models and an array of conventional and cutting-edge experimental techniques. Our results will illuminate sex-specific host-pathogen interactions in the infected kidney and identify UPEC virulence factors important in sex-dependent outcomes of upper-tract UTI. In addition, our preclinical findings will also be translationally relevant to recurrent UTI and renal scarring in human patient populations.