Deciphering the source and consequences of Nur77 expression during E. coli rUTI in mice

破译小鼠大肠杆菌 rUTI 期间 Nur77 表达的来源和后果

• 批准号: 10431538
• 负责人: Nicole Marie Gilbert
• 金额: $ 11.81万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-04-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10431538
• 关键词: Affect; Age; Antibiotic Resistance; Apoptosis; Applications Grants; Bacteria; Bacterial Vaginosis; Biological; Biological Assay; Bladder; Bladder Tissue; Bladder Urothelium; Breeding; Bypass; C57BL/6 Mouse; Catheterization; Cells; Clinical; Coitus; Data; Disease; Dot Immunoblotting; Epidemiology; Epithelial; Epithelial Cells; Escherichia coli; Exhibits; Exposure to; Female; Flow Cytometry; Future; Gardnerella vaginalis; Genetic Transcription; Genitourinary system; Histology; Human; Immediate-Early Genes; Immune; Immune response; Immunofluorescence Microscopy; Infection; Inflammation; Inflammatory; Inflammatory Response; Interferon Type II; Interleukin-12; Knock-out; Lactobacillus; Link; Mediating; Modeling; Molecular; Mus; Needles; Nuclear Orphan Receptor; Nuclear Receptors; Pathogenesis; Pathway interactions; Phosphate Buffer; Population; Predisposition; Production; Publishing; RANTES; Recurrence; Reporter; Research Personnel; Risk; Risk Factors; Role; Saline; Seeds; Source; Specific qualifier value; Stains; T-Lymphocyte; Testing; The Jackson Laboratory; Tissues; UPK3 gene; Urinary tract; Urinary tract infection; Urine; Urothelial Cell; Urothelium; Vagina; Wild Type Mouse; Woman; base; cell type; cost; cytokine; dysbiosis; experience; experimental study; insight; intravesical; male; microbial; mouse model; recurrent infection; renal epithelium; response; transcriptome sequencing

ABSTRACT Recurrent urinary tract infection (rUTI) is a costly clinical problem that affects millions of women worldwide and contributes to the global rise in antibiotic resistance. Multiple lines of evidence indicate that bacteria in the vagina can affect susceptibility to UTI. For example, women with the vaginal dysbiosis called bacterial vaginosis (BV) are at increased risk of UTI. Several vaginal bacteria—including the BV-associated species Gardnerella vaginalis (G.v.)—have been isolated from urine collected directly from the bladder by needle aspiration or transurethral catheterization. Although culture conditions are not often poised to detect it, the presence of G.v. in urine is also epidemiologically linked with rUTI. We have developed new mouse models to define the impact of vaginal bacteria on UTI from a new perspective—testing the idea that transient bladder exposures to vaginal bacteria such as G.v. influence the pathogenesis of Escherichia coli (E.c.), the leading cause of UTI. We previously demonstrated that G.v. triggers apoptosis and exfoliation of the bladder epithelium in mice. When mice harbored latent intracellular bladder reservoirs of E.c. from a prior experimental infection, G.v. triggered emergence of E.c. and rUTI at a rate 4-fold higher than mice exposed to vehicle alone. These data indicate that bladder exposures to G.v. could represent a trigger of rUTI in women. To understand at the cellular and molecular level how G.v. triggers exfoliation and rUTI, we have examined the transcriptional response to G.v. in the bladder using bulk RNA sequencing. This analysis revealed that G.v. induced the expression of the orphan nuclear receptor Nur77 (also called Nr4a1). Nur77 is well-recognized for its role in apoptosis and in inflammatory responses in diseases in other tissues, but its role in the urinary tract is largely unstudied. Our preliminary data using Nur77-/- mice indicate that Nur77 is required for G.v. to trigger E.c. rUTI in our mouse model. In this focused R03, we seek to answer two fundamental questions regarding the contribution of Nur77 to G.v.-induced E.c. rUTI: Which cell types in the bladder express Nur77 following G.v. exposure? (Aim 1), and Which host responses to G.v. exposure—exfoliation or inflammatory cytokine production—are mediated by Nur77? (Aim 2). Our proposed experiments build upon our preliminary data and leverage available Nur77 knockout and reporter mice and our experience in detailing bladder responses to microbial exposures. Successful completion of these studies will provide important mechanistic insights into how G.v. triggers E.c. rUTI and will generate key data on which to build a future R01 proposal.

抽象的 复发性尿路感染 (rUTI) 是一个代价高昂的临床问题，影响着全世界数百万女性， 多种证据表明，阴道内的细菌导致了全球抗生素耐药性的上升。 会影响对尿路感染的易感性，例如，患有称为细菌性阴道病 (BV) 的阴道生态失调的女性。 多种阴道细菌（包括 BV 相关细菌阴道加德纳菌）的风险增加。 (G.v.)——通过针吸或经尿道直接从膀胱收集的尿液中分离出来 尽管培养条件通常无法检测到 G.v，但尿液中也存在 G.v。 我们开发了新的小鼠模型来确定阴道感染的影响。 从新的角度研究细菌对尿路感染的影响——检验膀胱短暂暴露于阴道细菌的观点 例如 G.v. 影响大肠杆菌 (E.c.) 的发病机制，而大肠杆菌是尿路感染的主要原因。 证明当小鼠怀有 G.v. 时，会引发小鼠膀胱上皮细胞的凋亡和脱落。 来自先前实验感染的潜在膀胱内储存库，G.v. 引发了 E.c. 和 rUTI 的发生率比仅暴露于媒介物的小鼠高 4 倍。这些数据表明膀胱暴露。 G.v. 可能是女性发生 rUTI 的诱因。 为了在细胞和分子水平上了解 G.v. 如何引发剥脱和 rUTI，我们研究了 使用批量 RNA 测序对膀胱中的 G.v. 进行转录反应。 诱导孤儿核受体 Nur77（也称为 Nr4a1）的表达是众所周知的。 它在其他组织疾病的细胞凋亡和炎症反应中的作用，但它在泌尿道中的作用是 我们使用 Nur77-/- 小鼠的初步数据表明，G.v. 需要 Nur77。 在我们的小鼠模型中，rUTI 是重点关注的 R03，我们试图回答有关 rUTI 的两个基本问题。 Nur77 对 G.v. 诱导的 E.c. rUTI 的贡献：G.v. 后膀胱中哪些细胞类型表达 Nur77 暴露？（目标 1），以及哪种宿主对 G.v. 暴露有反应——剥落或炎症细胞因子。 生产——由 Nur77 介导？（目标 2）。 利用现有的 Nur77 敲除小鼠和报告小鼠以及我们在详细描述膀胱反应方面的经验 成功完成这些研究将为了解微生物暴露的机制提供重要的见解。 G.v. 触发 E.c. rUTI 并将生成用于构建未来 R01 提案的关键数据。