Regulation of Innate Immunity and Inflammation Through Nuclear Reprogramming

 产品说明： 退伍军人群体中的炎症性疾病以多种方式出现，从感染，特别是伤口感染，到因图尔斯服役压力而加重的代谢紊乱。其后遗症范围从急性、危及生命的微生物炎症到慢性和使人衰弱的代谢性炎症。机体对微生物（细菌、真菌、病毒）和代谢（过量胆固醇、甘油三酯、尿酸）损伤的反应由先天免疫和炎症介导。无论刺激的来源是什么，这种反应起初是有益的，但很快就会在多个器官中引起有害的炎症和代谢变化。对微生物和代谢刺激的先天免疫应答的共同联系是细胞内信号传导至细胞核，其中基因组被重新编程以使炎症永久化。然而，炎症和代谢信号在疾病发展中的相互关系知之甚少。我们已经开发了核转运调节剂（NTMs），这是一种细胞穿透肽，旨在抑制称为输入蛋白α 5（Imp α5）和输入蛋白β 1（Imp β1）的细胞内核衔接蛋白将炎症和脂质控制信号分别穿梭至细胞核。NTM通过靶向Imp α5介导的应激反应转录因子（SRTF）的核转运来减少炎症，例如核因子κ B，其是炎症和免疫的主要调节剂。NTMs还抑制Imp β1介导的固醇调节元件结合蛋白（SREBP）转录因子的核转运，这些转录因子是胆固醇、甘油三酯和脂肪酸合成和摄取的主要调节因子。在微生物、自身免疫性和代谢性疾病的相关临床前模型中，NTMs已有效改善炎症过程。我们假设微生物炎症主要依赖于Imp α5途径，而代谢性炎症需要Imp α5和Imp β1介导的途径。我们进一步假设SRTF/Imp α5和SREBP/Imp β1信号通路之间的相互作用使脂肪过多的个体更容易受到微生物的侵害。我们将应用新设计和生产的NTMs作为独特的探针，独立地靶向Imp α5或Imp β1，并分析它们介导的两种途径。我们将采用以细胞为基础的试验和临床前炎症模型，这些模型是由一种强有力的促炎微生物毒力因子、细菌内毒素或高脂肪饮食在易患动脉粥样硬化的小鼠品系中诱导的。有了这些独特的探针，Aim 1将定义这两种不同的核转运信号通路在微生物炎症中的作用，而Aim 2将定义它们在代谢炎症中的作用。目的3比较SRTF/Imp α5和SREBP/Imp β1信号通路在肥胖个体内毒素超敏反应中的作用。累积起来，我们的核转运机制研究将产生急需的信息，先天免疫反应的微生物和代谢的侮辱，由SRTFs和SREBP调节。

 DESCRIPTION: Inflammatory diseases in the Veteran population arise in many ways, ranging from infections, especially of wounds, to metabolic disorders aggravated by stress from tours of duty. Their sequelae range from acute, life-threatening microbial inflammation to chronic and debilitating metabolic inflammation. The body's response to microbial (bacteria, fungi, viruses) and metabolic (excess cholesterol, triglycerides, uric acid) insults is mediated by innate immunity and inflammation. Whatever the source of the stimulus, the response is at first beneficial, but can soon induce harmful inflammatory and metabolic changes in multiple organs. The common nexus of innate immune responses to microbial and metabolic stimuli is intracellular signaling to the nucleus, where the genome is reprogrammed to perpetuate inflammation. However, the interrelation of inflammatory and metabolic signaling in development of disease is poorly understood. We have developed nuclear transport modifiers (NTMs), cell-penetrating peptides designed to inhibit the intracellular nuclear adaptor proteins known as importin alpha 5 (Imp α5) and importin beta 1 (Imp β1) from shuttling both inflammatory and lipid-controlling signals, respectively, to the nucleus. NTMs reduce inflammation by targeting Imp α5-mediated nuclear transport of Stress-Responsive Transcription Factors (SRTFs), exemplified by nuclear factor kappa B, the master regulator of inflammation and immunity. NTMs also inhibit Imp β1-mediated nuclear transport of Sterol Regulatory Element-Binding Protein (SREBP) transcription factors, the master regulators of cholesterol, triglyceride, and fatty acid syntheses and uptake. NTMs have been effective in ameliorating the inflammatory process in relevant preclinical models of microbial, autoimmune, and metabolic diseases. We hypothesize that microbial inflammation is dependent mainly on the Imp α5 pathway whereas metabolic inflammation requires both Imp α5- and Imp β1-mediated pathways. We further hypothesize that cross-talk between the SRTF/Imp α5 and SREBP/Imp β1 signaling pathways predisposes individuals with excessive fat to be more susceptible to microbial insults. We will apply newly designed and produced NTMs as unique probes to independently target Imp α5 or Imp β1 and analyze the two pathways they mediate. We will employ cell-based assays and preclinical models of inflammation induced by a potent proinflammatory microbial virulence factor, bacterial endotoxin, or by a High Fat Diet in atherosclerosis-prone mouse strains. With these unique probes already in hand, Aim 1 will define the role of these two distinct nuclear transport signaling pathways in microbial inflammation, while Aim 2 will define their role in metabolic inflammation. Aim 3 will analyze the comparative roles of SRTF/Imp α5 and SREBP/Imp β1 signaling pathways in development of hypersensitivity to endotoxin in individuals with excessive fat. Cumulatively, our mechanistic studies of nuclear transport will yield much-needed information about innate immune responses to microbial and metabolic insults that are regulated by SRTFs and SREBPs.