Targeting proteotoxic stress responses in liver fibrosis

靶向肝纤维化中的蛋白毒性应激反应

基本信息

批准号：
9333852
负责人：
Pranoti Mandrekar
金额：
$ 38.98万
依托单位：
UNIV OF MASSACHUSETTS MED SCH WORCESTER
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-07-20 至 2022-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9333852
关键词：
Alcohols Candidate Disease Gene Cell physiology Cells Cellular Stress Chronic Cirrhosis Clinical Collagen Type I Data Dependence Development Endoplasmic Reticulum Exposure to Extracellular Matrix Fibroblasts Fibrosis Gene Targeting HSF1 HSP 90 inhibition Heat-Shock Proteins 70 Heat-Shock Proteins 90 Hepatic Stellate Cell Hepatitis B Hepatitis C In Vitro Inflammation Inflammatory Injury Investigation Knock-out Knockout Mice Knowledge Link Liver Liver Fibrosis Mediating Modeling Molecular Chaperones Morbidity - disease rate Myofibroblast Non-Insulin-Dependent Diabetes Mellitus Obesity Oxidative Stress Oxidative Stress Pathway Pathogenesis Pathogenicity Pathway interactions Plasmids Play Primary carcinoma of the liver cells Process Property Proteins Recovery Regulation Reporting Resolution Role Signal Transduction Stimulus Stress Testing Therapeutic Viral hepatitis Wound Healing biological adaptation to stress cytokine design effective therapy fibrogenesis global health in vivo inhibitor/antagonist mortality nanoparticle nonalcoholic steatohepatitis novel overexpression pre-clinical proteostasis proteotoxicity public health relevance response stellate cell stress protein transcription factor

项目摘要

ABSTRACT Liver fibrosis is linked to inflammation and deregulated wound healing response, triggered by chronic exposure to various types of insults including alcohol, obesity, NASH and viral hepatitis. Recently emerging liver therapies directed to eliminate the pathogenic agent suggest promise in resolving fibrosis. However, to design anti-fibrotic therapeutic strategies we need a better understanding of the pathogenesis of fibrosis. Accumulation of extracellular matrix is the hallmark of hepatic fibrosis. Hepatic stellate cells (HSCs) are activated by pro-fibrogenic stimuli and are the main ECM producing cells in the liver. The role of oxidative stress and inflammatory cytokines in HSC activation has been under extensive investigation. Targeting stress pathways to inactivate HSCs is an attractive therapeutic strategy and crucial to effective treatment. Stress induced transcription factor and master regulator of proteotoxic responses, HSF1 mediates induction of HSP90 and HSP70, stress chaperones important in inflammatory signaling and likely to play a role in HSC activation and reversion, respectively. Our preliminary data show that deficiency of HSF1, unable to induce HSP70 promotes HSC activation and fibrosis and moreover, is unable to resolve HSC activation and fibrosis in a model of fibrosis recovery. Increased cytosolic HSP90AA1 and endoplasmic reticulum (ER), HSP90B1/Grp94/gp96 in fibrotic livers may contribute to fibrogenesis. Targeting HSP90, using a specific inhibitor, 17-DMAG, which induces HSF1 activation and downstream HSP70, will delineate the role of HSF1-HSP70 in inactivation of hepatic stellate cells. We hypothesize that HSF1 inactivity and HSP90 induction during stellate cell activation contributes to liver fibrosis, whereas induction of HSF1 and HSPA1A/HSP70 contributes to resolution of fibrosis. The Specific Aims are- 1) To unravel the role of stress mediated transcription factor, HSF1 on regulation of liver fibrosis by: Examining the effect of stellate cell specific knock-out of HSF1 on fibrogenesis; Testing effect of HSF1-plasmid nanoparticles on fibrosis resolution; Evaluating longitudinal expression, activity and novel target genes regulated by HSF1 during fibrosis and resolution. 2) To assess whether targeting HSP90AA1 (cytosolic) and/or HSP90B1/Grp94/gp96(ER) regulates stellate cell activation and fibrogenesis by: Evaluating the induction of HSP90AA1 and gp96 during stellate cell activation; Investigating effect of hsp90 inhibitor, 17-DMAG on liver fibrosis; Determining effect of stellate cell-specific inhibition of gp96 and HSP90 in vivo, on hepatic fibrosis. 3) To investigate importance of HSF1 induced HSP70 in stellate cell function by: Determining induction of Hsp70 and its dependence on HSF1, during resolution of fibrosis; Investigating whether overexpression of HSP70 inactivates HSC and resolves fibrosis; Evaluating HSF1-HSP70 axis during 17-DMAG treatment on HSC activation and fibrosis. Our proposed studies will unravel the role of HSF1 mediated stress pathways and chaperones in stellate cell activation and fibrosis.

抽象的肝纤维化与慢性炎症和伤口愈合反应失调有关。暴露于各种类型的侮辱，包括酒精、肥胖、NASH 和病毒性肝炎。最近出现的旨在消除病原体的肝脏疗法有望解决纤维化问题。然而，为了设计抗纤维化治疗策略我们需要更好地了解纤维化的发病机制。细胞外基质的积累是肝纤维化的标志。肝星状细胞 (HSC) 是由促纤维化刺激激活，是肝脏中主要的 ECM 产生细胞。氧化的作用应激和炎症细胞因子在 HSC 激活中的作用已得到广泛研究。瞄准应激途径使 HSC 失活是一种有吸引力的治疗策略，对于有效治疗至关重要。应激诱导转录因子和蛋白毒性反应的主要调节因子，HSF1 介导 HSP90 和 HSP70 的诱导，应激伴侣在炎症信号传导中很重要，并可能发挥重要作用分别在 HSC 激活和逆转中发挥作用。我们的初步数据表明HSF1的缺乏，无法诱导 HSP70 促进 HSC 活化和纤维化，而且无法分解 HSC 纤维化恢复模型中的激活和纤维化。胞浆 HSP90AA1 和内质增加网状结构 (ER)、纤维化肝脏中的 HSP90B1/Grp94/gp96 可能有助于纤维化。针对 HSP90，使用特定的抑制剂 17-DMAG，它会诱导 HSF1 激活和下游 HSP70，将描述 HSF1-HSP70 在肝星状细胞失活中的作用。我们假设 HSF1 不活动并且星状细胞激活过程中 HSP90 的诱导导致肝纤维化，而 HSF1 和 HSPA1A/HSP70 有助于纤维化的消退。具体目标是 - 1) 解开应激介导的转录因子 HSF1 对肝纤维化调节的作用：检查效果星细胞特异性敲除HSF1对纤维发生的影响； HSF1-质粒纳米粒子的测试效果纤维化消退；评估 HSF1 调控的纵向表达、活性和新靶基因在纤维化和消退期间。 2) 评估是否靶向HSP90AA1（胞质）和/或 HSP90B1/Grp94/gp96(ER) 通过以下方式调节星状细胞活化和纤维发生：星状细胞激活过程中的HSP90AA1和gp96；研究 hsp90 抑制剂 17-DMAG 对肝脏的影响纤维化；确定体内星状细胞特异性抑制 gp96 和 HSP90 对肝纤维化的影响。 3) 通过以下方式研究 HSF1 诱导的 HSP70 在星状细胞功能中的重要性： Hsp70 及其在纤维化消退过程中对 HSF1 的依赖性；调查是否过度表达 HSP70 灭活 HSC 并解决纤维化问题；在 17-DMAG 治疗期间评估 HSF1-HSP70 轴 HSC 活化和纤维化。我们提出的研究将揭示 HSF1 介导的应激途径的作用以及星状细胞活化和纤维化中的伴侣。