CSN8 regulation of S1P-enriched extracellular vesicles to modulate NAFLD by gut-liver axis

这个项目的首要主题是解决肠道衍生的细胞外囊泡的机制 非酒精性脂肪性肝病（NAFLD）中EV诱导的肝脏炎症/损伤。我们将决定 鞘脂代谢物，特别是;富含鞘氨醇1-磷酸（S1 P）的肠道EV和途径 CSN 8/SphK 1与NAFLD的关系目前的提案将肠道衍生的EV与巨噬细胞联系起来- 介导的炎症，提出细胞外囊泡从肠道招募巨噬细胞到肝脏， 导致肝损伤和炎症。我们最近的工作已经开始确定肠道炎症引起的 改变，并表明肠源性EV在NKT细胞和Th 17的调节中起关键作用 细胞通过肠-肝轴参与肝脏炎症和结肠癌的发展。我们的初步数据显示 LPS促进肠上皮细胞（IEC）释放富含鞘脂代谢物的促炎性细胞因子， EV包括神经酰胺和S1 P。我们的初步研究结果还表明，CSN 8/SphK 1信号通路 在生产富含S1 P的电动汽车中起着关键作用。慢性高脂肪饮食消费导致增加 肠通透性，并使肝脏暴露于肠源性产物，包括IEC的EV。增加S1 P富集 EV激活其在肝巨噬细胞上的受体S1 P1，这可能促进巨噬细胞趋化性进入肝巨噬细胞。 肝脏这导致了核心假设，即肠道微生物群调节鞘脂代谢物- 通过肠道CSN 8/SphK 1途径富集EV的生物合成和释放以及携带鞘脂的肠道EV 代谢物（神经酰胺和S1 P）转移到肝脏，进而吸引巨噬细胞进入肝脏 促进NAFLD中的肝损伤。重要的是，该提案还追求翻译研究， 基于营养纳米颗粒的针对肠道微生物群和SphK 1-S1 PR 1的治疗干预的功效 抑制减轻肠-肝轴变化。为了解决我们的假设，我们提出以下具体目标： 目的1：确定肠源性EVs-S1 P是否通过CSN 8/SphK 1途径调节肝脏炎症和损伤 在NAFLD。目的2：确定肠源性EVs-S1 P是否有助于肝巨噬细胞 在NAFLD中通过S1 PR 1-STAT 3的募集/激活。目的3：定义CSN 8和CSN 9的分子机制。 SphK 1相互调节和CSN 8/S1 P-S1 PR 1信号的调节将阻止巨噬细胞 介导的NAFLD肝损伤。该提案将更好地了解饮食-肠道-肝脏的相互作用， 有助于EVs-S1 P诱导的肝脏炎症和损伤的发病机制的分子机制。的 这项研究将导致确定新的治疗靶点和治疗NAFLD的潜在饮食干预措施。

The overarching theme of this project is to address the mechanisms underlying gut derived extracellular vesicles (EVs)-induced liver inflammation/injury in Non-alcoholic fatty liver disease (NAFLD). We will determine the role of sphingolipid metabolites, specifically; Sphingosine 1-phosphate (S1P)-enriched gut EVs and pathway CSN8/SphK1 in the development of NAFLD. The current proposal links gut-derived EVs to macrophage- mediated inflammation by proposing that extracellular vesicles from gut recruit macrophages to the liver, resulting in liver injury and inflammation. Our recent work has begun to identify intestinal inflammation-induced alterations in EVs, and shows that gut-derived EVs play a critical role in the regulation of NKT cells and Th17 cells in the development of liver inflammation and colon cancer via gut-liver axis. Our preliminary data shows that LPS promotes Intestinal epithelial cells (IECs) release sphingolipid metabolites-enriched pro-inflammatory EVs including ceramide and S1P. Our preliminary findings also indicate that CSN8/SphK1 signaling pathway plays a crucial role in the production of S1P-enriched EVs. Chronic high fat diet consumption leads to increased gut permeability and expose the liver to gut-derived products including EVs of IECs. Increased S1P-enriched EVs activate its receptor S1P1 on hepatic macrophages, which may promote macrophage chemotaxis into the liver. This has led to the central hypothesis that gut microbiota regulate sphingolipid metabolites- enriched EVs biogenesis and release via gut CSN8/SphK1 pathway and gut EVs carrying sphingolipid metabolites (ceramide and S1P) translocate to liver, which in turn attract macrophages into the liver promoting liver injury in NAFLD. Importantly, the proposal also pursues translational studies that examine the efficacy of nutrition-nanoparticles based therapeutic interventions targeted at gut microbiota and SphK1-S1PR1 inhibition in mitigating gut-liver axis changes. To address our hypothesis, we propose the following specific aims: Aim 1: Determine whether gut-derived EVs-S1P regulate liver inflammation and injury via CSN8/SphK1 pathway in NAFLD. Aim 2: Determine whether gut-derived EVs-S1P contribute to liver macrophages recruitment/activation by S1PR1-STAT3 in NAFLD. Aim 3: Define molecular mechanisms underlying CSN8 and SphK1 reciprocal regulation and modulation of the CSN8/S1P-S1PR1 signal will prevent macrophages mediated-liver injury in NAFLD. The proposal will provide a better understanding of diet-gut-liver interactions and molecular mechanisms contributing to the pathogenesis of EVs-S1P-induced liver inflammation and injury. The study will lead to identification of new therapeutic targets and potential dietary interventions for treating NAFLD.