Novel synthetic analogue of microbial metabolite, Urolithin A, mitigates inflammatory bowel diseases

项目总结/摘要 炎症性肠病（IBD），包括溃疡性结肠炎和克罗恩病， 在美国有140万人。慢性炎症和微生物生态失调是IBD的主要特征。 健康饮食习惯带来的有益效果在个人之间并不一致，并归因于 肠道微生物群及其活性代谢物的变化。克服个体间差异的挑战 在肠道微生物群中，它们代谢产物和差的生物利用度，在此我们建议直接使用微生物 代谢物来维持肠道免疫稳态以减轻IBD。尿石素A（UroA）是一种有益的 源自鞣花酸和鞣花单宁的微生物代谢物，它们是浆果的主要多酚成分， 石榴。基于UroA结构，我们开发了新的有效结构类似物UAS 03，其表现出 与母体UroA化合物相比，抗炎和肠道屏障功能活性增加。的 目前的提案研究了UAS 03的分子和细胞机制及其在以下方面的治疗功效： IBD临床前模型。 我们的初步结果表明，口服给予UAS 03减轻了葡聚糖钠中的结肠炎， 硫酸盐（DSS）或2，4，6-三硝基苯磺酸（TNBS）诱导的小鼠结肠炎，即使在低10倍的剂量下也是如此 与UroA相比。UAS 03显著抑制脂多糖（LPS）诱导的炎性细胞因子增加。 免疫细胞和上皮细胞中的介质，其功效比UroA高10倍。此外，治疗与 UAS 03通过激活核因子上调连接蛋白降低肠通透性 （红系衍生2）样2（Nrf 2）-血红素加氧酶（HO 1）途径。基于这些结果，我们 提出了UAS 03和UroA的双管齐下的有益活性，其中这些化合物保护宿主免受 通过保护肠道屏障功能和抑制炎症活动来应对外部挑战。在本提案中，我们 将测试这样的假设，即“用UAS 03（一种微生物代谢物的有效类似物）治疗， 通过减少屏障功能障碍和炎症来预防IBD的发展。在目标1中，我们将研究如何 USA 03/UroA通过上调连接蛋白以Nrf 2依赖性方式增加肠道屏障功能， 以及涉及UAS 03抗炎活性的分子事件。在目标2中， 将在急性、慢性和自发性IBD临床前模型中检查UAS 03和UroA。在目标3中， 建议鉴定负责UroA生产的细菌，并在结肠炎模型中测试其益生菌活性。 拟议研究的成功完成将有助于理解UAS 03和UroA的机制， 行动，并建立了基础的治疗使用IBD。

Project Summary/Abstract Inflammatory Bowel Diseases (IBDs), which include f ulcerative colitis and Crohn’s disease, affect as many as 1.4 million people in the USA. Chronic inflammation and microbial dysbiosis are major features of IBDs. Beneficial effects rendered by healthy dietary practices are not uniform among individuals and are attributed to variations in gut microbiota and their active metabolites. To overcome the challenge of inter-individual differences in gut microbiota, their metabolites and poor bioavailability, here we propose direct usage of microbial metabolites to maintain gut immune homeostasis to mitigate IBDs. Urolithin A (UroA) is one of such beneficial microbial metabolite derived from ellagic acid and ellagitannins, major polyphenolic components of berries and pomegranate. Based on UroA structure, we developed novel potent structural analogue, UAS03, which exhibited increased anti-inflammatory and gut barrier functional activities compared to parent UroA compound. The current proposal investigates the molecular and cellular mechanisms of UAS03 and its therapeutic efficacies in IBD pre-clinical models. Our preliminary results showed that the oral administration of UAS03 mitigated colitis in dextran sodium sulphate (DSS)- or 2,4,6-Trinitrobenzenesulfonic acid (TNBS) induced murine colitis even at 10 fold lower dose compared to UroA. UAS03 significantly inhibited lipopolysaccharide (LPS)-induced increase in inflammatory mediators in immune cells and epithelial cells with 10 fold higher efficacy than UroA. Further, treatment with UAS03 reduced intestinal permeability by up-regulating junctional proteins through activation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2)-hemoxygenase (HO1) pathways in epithelial cells. Based on these results, we propose two-pronged beneficial activities of UAS03 and UroA, where these compounds protect the host from external challenges by protecting gut barrier function and dampening inflammatory activities. In this proposal we will test the hypothesis that ‘treatment with UAS03, an effective analogue of a microbial metabolite, protects from IBD development by reducing barrier dysfunction and inflammation. In Aim 1, we will investigate how USA03/UroA increase gut barrier function in a Nrf2-dependent manner by upregulating junctional proteins as well as molecular events involved anti-inflammatory activities of UAS03. In Aim 2, therapeutic efficacies of UAS03 and UroA will be examined in acute, chronic and spontaneous IBD pre-clinical models. In Aim 3, we propose to identify the bacteria responsible for UroA production and test their pro-biotic activities in colitis models. The successful completion of proposed studies will allow understanding of UAS03 and UroA mechanisms of actions, and establishes the basis for therapeutic usage in IBDs.