Heat shock protein 90 in alcoholic liver disease: targeting macrophage Function

摘要 肝脏免疫细胞激活是酒精相关性肝病(ALD)的核心，目前对此知之甚少。 蛋白质动态平衡网络/通路在保护细胞蛋白质组免受细胞应激中起着至关重要的作用。 其中，蛋白调节介质hsp90作为治疗靶点得到了广泛的研究和探索。 在癌症中。我们报道了HSP90的两种亚型，HSP90AA1(应激诱导的细胞质HSP90)和 HSP90B1/GP96(HSP90的内质网旁路)在ALD中起重要作用。这些研究指出， 热休克蛋白90在ALD中的病理生理作用本项目上一次资助期的研究表明 肝靶向HSP90抑制剂17-DMAG在ALD中使用纳米粒可以预防和逆转肝损伤， 巨噬细胞gp96/HSP90B1缺陷促进肝脏炎症的消退和ALD、M-TLR4缺陷 抑制热休克蛋白90可降低NLRP3炎症体活性降低IL-1β 蛋白质和HSF1部分参与了促炎信号的减少，而HSF1的缺失则起到了作用 不能保护ALD，这表明HSF1对ALD的解决没有贡献。在下一个项目期间 我们将探讨HSP90AA1和HSP90B1/GP96在酒精性肝损伤中的作用机制 巨噬细胞活化导致酒精性肝病。我们认为HSP90通过另一种机制诱导炎症 (独立于HSP90/TLR4轴)，例如巨噬细胞通过表观遗传机制的有氧糖酵解或 HIF1α。在我们的初步数据中，我们发现HSP90AA1在ALD的细胞核中被检测到，并且它的抑制可以 调节染色质修饰酶的表达。试点数据还显示，HSP90AA1的抑制作用 减少酒精介导的葡萄糖转运蛋白(SLC2A1/GLUT1)和己糖激酶II(两个重要的 糖酵解的介体，提示HSP90在ALD中M1巨噬细胞的代谢编程中发挥作用。在……上面 另一方面，HSP90B1/GP96最好在肝巨噬细胞中诱导，通过糖酵解促进炎症 其抑制可诱导GRP78、ATF3、TREM2的恢复性/修复性巨噬细胞分解ALD。我们 假设酒精诱导的HSP90AA1通过表观遗传学促进巨噬细胞有氧糖酵解 HSP90B1/GP96和内质网应激通过HIF1α促进ALD巨噬细胞糖酵解的机制。 抑制ALD中HSP90通过OXPHOS易化诱导ATF3-TREM2修复性巨噬细胞 保护。本提案的具体目的是：1)鉴定HSP90AA1介导的表观遗传和代谢 小鼠酒精性肝病和人急性酒精性肝病外周血单核细胞的巨噬细胞程序化2)描述 巨噬细胞特异性HSP90B1/GP96在巨噬细胞代谢中的意义 巨噬细胞中ATF3和TREM2对肝损伤的保护作用。集体地，在下一个项目期间 期间，我们的研究将识别由HSP90调节的新的代谢和表观遗传机制，并表征 修复性巨噬细胞在ALD的解决中起关键作用。在小鼠ALD模型和人类中研究这些通路 患者单核细胞将为HSP90在ALD中的临床应用提供基础。

ABSTRACT Liver immune cell activation is central to alcohol associated liver disease (ALD) and is poorly understood. The protein homeostasis network/pathways are crucial in safeguarding the cellular proteome from cellular stress. Amongst these, proteostasis mediator HSP90 is widely studied and extensively explored as a therapeutic target in cancer. We reported two isoforms of HSP90, HSP90AA1 (stress inducible cytoplasmic HSP90) and HSP90B1/GP96 (Endoplasmic reticulum paralog of HSP90) are important in ALD. These studies point to a pathophysiological role for HSP90 in ALD. Studies during the last funding period of this project established that liver targeting of HSP90 inhibitor 17-DMAG using nanoparticles in ALD can prevent and reverse liver injury, GP96/HSP90B1 deficiency in macrophages facilitates resolution of liver inflammation and ALD, M-TLR4 deficient mice are not protected from ALD, inhibition of HSP90 reduced NLRP3 inflammasome activity decreasing IL-1β protein and HSF1 partially contributes to reduced pro-inflammatory signaling, whereas deficiency of HSF1 did not protect from ALD, suggesting that HSF1 does not contribute to resolution of ALD. In the next project period we will investigate mechanisms mediated by HSP90AA1 and HSP90B1/GP96 in alcohol induced liver macrophage activation resulting in ALD. We propose that HSP90 induces inflammation by alternate mechanisms (independent of HSP90/TLR4 axis), for instance macrophage aerobic glycolysis via epigenetic mechanisms or HIF1α. In our preliminary data, we found that HSP90AA1 is detected in the nucleus in ALD and its inhibition can modulate expression of chromatin-modifying enzymes. Pilot data also reveal that inhibition of HSP90AA1 reduces alcohol mediated induction of glucose transporter (SLC2a1/GLUT1) and hexokinase II, two important mediators of glycolysis, suggesting a role for HSP90 in metabolic programming of M1 macrophages in ALD. On the other hand, HSP90B1/GP96 induced preferably in liver macrophages promotes inflammation via glycolysis and its inhibition induces GRP78+ATF3+Trem2+ restorative/reparative macrophages resolving ALD. We hypothesize that alcohol induced HSP90AA1 facilitates macrophage aerobic glycolysis via epigenetic mechanisms whereas HSP90B1/GP96 and ER stress facilitate macrophage glycolysis via HIF1α in ALD. Inhibition of HSP90 in ALD induces ATF3+Trem2+ reparative macrophages using OXPHOS facilitating protection. The specific Aims of this proposal are - 1) To identify HSP90AA1 mediated epigenetic and metabolic programming of macrophages in murine ALD in vivo and human AH PBMCs in vitro. 2) To characterize the significance of macrophage-specific HSP90B1/GP96 in macrophage metabolism and assess significance of ATF3 and TREM2 in macrophages conferring protection from liver injury. Collectively, during the next project period our studies will identify novel metabolic and epigenetic mechanisms regulated by HSP90 and characterize reparative macrophages crucial in resolution of ALD. Studying these pathways in mouse ALD model and human AH patient monocytes will provide basis for future clinical development of HSP90 in ALD.