Intestinal Homeostasis Induced by Commensals

摘要 虽然包括 P-gp 和 MRP2 在内的多药耐药转运蛋白通常因其 role in exporting drugs and foreign compounds from the cell, our studies indicate that these efflux 在肠上皮细胞顶端表面表达的泵提供了关键的联系 communication between sentinel functions of mucosal barriers and the immune system. Understanding how this P-gp/eCB anti-inflammatory arm is regulated will provide crucial insight into how dysfunction may promote intestinal inflammation and help identify potential new 治疗目标。 Because the resident microbiota is known to contribute to tolerance and homeostasis in the healthy intestine, the central hypothesis we aim to test is whether the normal 微生物群积极驱动 P-gp/eCB 轴以防止不必要的炎症。我们的飞行员 studies indicate that the microbiota does influence P-gp expression and function, providing a unique foundation for further cause-effect studies.之前没有数据表明存在联系 between the microbiota and eCBs or any other epithelial lipid signals, and may well provide great 洞察一个新颖的系统。 Bridging this gap could help explain how commensal bacteria can stabilize a state of tolerance and how genetic modification of specific pathway elements might 使个体易患炎症性肠病（IBD）。开始寻址 these questions, in Aim 1 of this application will combine in vitro (including human colonoids) and 体内小鼠模型系统，以及使用健康和 UC 患者粪便，更深入地研究 understand the microbial consortia that collectively maximize P-gp expression and function.目标 2 旨在鉴定驱动 P-gp 表达激活的微生物代谢物和 eCB secretion to maintain an anti-inflammatory tone in the intestinal epithelium.因此， 将进行转录组学和代谢物分析，以提供有关 微生物基因、基因簇及其代谢产物与维持抗- inflammatory tone in the intestinal epithelium through regulation of the P-gp/eCB axis.目标 3 我们将采用新颖的计算方法来揭示微生物间的网络反应 以及能够诱导P-gp表达的稳定群落的生态结构。 Collectively, knowledge of the pathways that coordinate the maintenance of the P-gp/eCB axis 需要全面了解调节肠道稳态的不同信号， 多种信号如何在复杂的肠道环境中整合，以及这些信号的通路 调节宿主-微生物相互作用。因此，该提案将直接推进新颖的 生物学原理指导新的治疗干预策略。

ABSTRACT While multidrug-resistance transporters including P-gp and MRP2 are generally studied for their role in exporting drugs and foreign compounds from the cell, our studies indicate that these efflux pumps expressed at the apical surface of intestinal epithelial cells provide a critical link in communication between sentinel functions of mucosal barriers and the immune system. Understanding how this P-gp/eCB anti-inflammatory arm is regulated will provide crucial insight into how dysfunction may promote intestinal inflammation and help identify potential new therapeutic targets. Because the resident microbiota is known to contribute to tolerance and homeostasis in the healthy intestine, the central hypothesis we aim to test is whether the normal microbiota actively drives the P-gp/eCB axis to prevent unnecessary inflammation. Our pilot studies indicate that the microbiota does influence P-gp expression and function, providing a unique foundation for further cause-effect studies. No data have previously demonstrated a link between the microbiota and eCBs or any other epithelial lipid signals, and may well provide great insight into a novel system. Bridging this gap could help explain how commensal bacteria can stabilize a state of tolerance and how genetic modification of specific pathway elements might predispose individuals to conditions of inflammatory bowel disease (IBD). To begin addressing these questions, in Aim 1 of this application will combine in vitro (including human colonoids) and in vivo murine model systems, as well as use healthy and UC patient stool, to more deeply understand the microbial consortia that collectively maximize P-gp expression and function. Aim 2 is designed to identify the microbial metabolites that drive activation of P-gp expression and eCB secretion to maintain an anti-inflammatory tone in the intestinal epithelium. Thus, transcriptomics and metabolite analyses will be performed to provide new information regarding microbial genes, gene clusters, and their metabolic products implicated in maintaining an anti- inflammatory tone in the intestinal epithelium through regulation of the P-gp/eCB axis. In Aim 3 we will employ novel computational methods will to uncover the inter-microbial network responses and the ecological structure of a stable community that is able to induce P-gp expression. Collectively, knowledge of the pathways that coordinate the maintenance of the P-gp/eCB axis will require a comprehensive understanding of distinct signals regulating intestinal homeostasis, how multiple signals are integrated in the complex intestinal environment, and pathways that modulate host-microbe interactions. Consequently, this proposal will directly advance novel biological principles with guidance of new therapeutic intervention strategies.