Role of Intestinal Proteostasis mediator HSP90 in alcoholic liver disease.

摘要 慢性酒精改变肠道微生物群(生物失调)，引发炎症，损害肠道屏障功能 导致肠道“渗漏”，微生物产物进入门脉循环，最终导致肝脏发炎。 目前针对微生物组或宿主途径以恢复屏障功能的治疗使用了抗生素， 益生菌、合生菌、粪便微生物组移植(FMT)、噬菌体疗法、FXR激动剂和营养素- 以治疗为基础。这项建议的主要目的是研究蛋白平衡介质在致病中的作用。 体内肠靶向应用特异性药物抑制物评价HSP90在肠道中的作用 酒精介导宿主肠道炎症、屏障功能和生物失调。两种主要形式的 哺乳动物应激诱导的HSP90同源基因是细胞质(CyT)HSP90AA1和HSP90B1/GP96。 内质网(ER)。HSP90和GP96的伴侣功能在免疫细胞微调中起关键作用 激活和炎症反应。热休克蛋白90等蛋白平衡伴侣在慢性阻塞性肺疾病中的确切作用 酒精引起的肠道功能障碍尚未得到研究。我们报告说，针对HSP90使用特定的 药理抑制剂17-DMAG，减少ALD的肠源性循环内毒素。髓系特异性 HSP90B1/GP96缺陷小鼠也表现出ALD循环内毒素的减少。进一步说明我们的初步数据 慢性酒精暴露小鼠肠道HSP90AA1和HSP90B1/GP96基因表达的诱导。在……里面 此外，17-DMAG在肠道中具有生物利用度，可抑制炎性细胞因子、空肠和肠组织中的肿瘤坏死因子α。 回肠。我们假设慢性酒精诱导宿主肠道中的HSP90有助于炎症和 ALD患者的肠道屏障功能受损。此外，由于针对肠道炎症的治疗性靶点可以恢复 保护微生物区系，以及考虑到17-DMAG的抗生素和抗真菌特性，很可能 17-DMAG治疗有利于保护肠道微生物区系，减少宿主肠道炎症。 总而言之，我们将在这里探索HSP90在酒精介导的肠道炎症和屏障功能中的作用 并评估宿主HSP90的药理学靶向是否影响肠道微生物区系。具体目标 1)评估HSP90异构体在酒精性肠炎中的作用 17-DMAG包裹纳米粒对HSP90异构体、肠道靶向性的研究 小肠炎性反应和固有层免疫细胞及髓系膜 特定的HSP90B1/GP96缺乏会影响肠道的炎症反应。2)评估功能 用通透性评价热休克蛋白90与酒精介导的肠屏障完整性和微生态失调的相关性 和上皮紧密连接蛋白在HSP90和髓系GP96抑制期间。B)评估以下措施的效果 肠道靶向纳米DMAG和髓系GP96缺乏症的微生物区系。圆满完成 拟议的研究将揭示蛋白平衡伴侣在肠道中的作用，并指导未来的研究 酒精介导的肠道损伤中的蛋白稳定途径。

ABSTRACT Chronic alcohol alters the enteric microbiome (dysbiosis), induces inflammation, impairs the gut barrier function resulting in a “leaky” gut, passage of microbial products into portal circulation and eventually liver inflammation. Current therapies targeting the microbiome or host pathways to restore barrier function have utilized antibiotics, probiotics, synbiotics, fecal microbiome transplant (FMT), bacteriophage therapy, FXR agonists and nutrient- based treatments. The major goal of this proposal is to investigate the pathogenic role of proteostasis mediator, HSP90 in the gut by intestinal targeting in vivo using specific pharmacological inhibitors to evaluate its effect on alcohol mediated host intestinal inflammation, barrier function and dysbiosis. Two predominant forms of mammalian stress inducible HSP90 paralogs are cytoplasmic (CYT) HSP90AA1 and HSP90B1/GP96 in the endoplasmic reticulum (ER). The chaperone function of HSP90 and GP96 is crucial in fine tuning immune cell activation and inflammatory responses. The precise role of proteostasis chaperones such as HSP90 in chronic alcohol mediated intestinal dysfunction is not yet investigated. We reported that targeting HSP90 using specific pharmacological inhibitor 17-DMAG, reduced gut derived circulating endotoxin in ALD. Myeloid specific HSP90B1/GP96 deficient mice also exhibit reduced circulating endotoxin in ALD. Further our preliminary data show induction of HSP90AA1 and HSP90B1/GP96 mRNA in intestine of chronic alcohol exposed mice. In addition, 17-DMAG is bioavailable in the intestine and inhibits inflammatory cytokine, TNFα in the jejunum and ileum. We hypothesize that chronic alcohol induces HSP90 in host intestine contributing to inflammation and compromising gut barrier function in ALD. In addition, since therapeutic targeting of gut inflammation can restore protective microbiota, as well as considering the antibiotic and antimycotic properties of 17-DMAG, it is likely that 17-DMAG treatment favors protective gut microbiota, facilitated by reduced host intestinal inflammation. Collectively, here we will explore the role of HSP90 in alcohol mediated gut inflammation and barrier function and also assess whether pharmacological targeting of host HSP90 impacts gut microbiota. The Specific Aims are: 1) To delineate the role of HSP90 isoforms on alcohol induced gut inflammation by- Evaluating expression of HSP90 isoforms, intestinal targeting of HSP90 using 17-DMAG encapsulated nanoparticles to study inflammatory responses in small intestine and immune cells in lamina propria and assessing whether myeloid specific HSP90B1/GP96 deficiency affects inflammatory responses in the gut. 2) To assess the functional relevance of HSP90 on alcohol mediated intestinal barrier integrity and dysbiosis by - Evaluating permeability and epithelial tight junction proteins during HSP90 and myeloid GP96 inhibition. B) Assessing the effect of intestine targeted nano-DMAG and myeloid GP96 deficiency on microbiota. Successful completion of the proposed studies will uncover the role of proteostasis chaperones in the gut and guide future studies to identify proteostasis pathways in alcohol mediated gut injury.