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.

抽象的肝纤维化与炎症和放松管状伤口愈合反应有关，由慢性触发暴露于各种类型的侮辱，包括酒精，肥胖，纳什和病毒肝炎。最近出现指示消除致病剂的肝疗法表明解决纤维化有望。但是，要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理。细胞外基质的积累是肝纤维化的标志。肝星细胞（HSC）是被促纤维化刺激激活，是肝脏中的主要ECM产生细胞。氧化的作用 HSC激活中的应激和炎症细胞因子一直在广泛的研究中。定位灭活HSC的应力途径是一种有吸引力的治疗策略，对有效治疗至关重要。应力诱导的转录因子和蛋白毒性反应的主要调节剂，HSF1介导 HSP90和HSP70的诱导，应力伴侣在炎症信号中很重要，并且可能发挥分别在HSC激活和回归中的作用。我们的初步数据表明，HSF1的不足，无法诱导HSP70促进HSC激活和纤维化以及无法解决HSC 纤维化恢复模型中的激活和纤维化。胞质HSP90AA1和内质增加增加纤维化肝脏中的网状（ER），HSP90B1/GRP94/GP96可能有助于纤维化。针对HSP90，使用特定的抑制剂，17-DMAG诱导HSF1激活和下游HSP70，将描绘 HSF1-HSP70在肝星状细胞失活中的作用。我们假设HSF1不活动和星状细胞活化期间的HSP90诱导有助于肝纤维化，而诱导 HSF1和HSPA1A/HSP70有助于解决纤维化。具体目的是-1）解开应力介导的转录因子HSF1对肝纤维化调节的作用：检查效果 HSF1在纤维发生上的星状细胞特异性敲除； HSF1-质粒纳米颗粒对测试作用对纤维化分辨率；评估HSF1调节的纵向表达，活性和新型靶基因在纤维化和分辨率期间。 2）评估靶向HSP90AA1（胞质）和/或 HSP90B1/GRP94/GP96（ER）调节星状细胞的激活和纤维发生：评估诱导的诱导星状细胞激活期间的HSP90AA1和GP96；研究HSP90抑制剂的作用，17-DMAG对肝脏纤维化；确定体内GP96和HSP90的星状细胞特异性抑制对肝纤维化的影响。 3）研究HSF1诱导的HSP70在星状细胞功能中的重要性：确定诱导的诱导 HSP70及其对HSF1的依赖，在纤维化解决过程中；调查是否过表达 HSP70使HSC失活并解决纤维化；在17-DMAG处理过程中评估HSF1-HSP70轴 HSC激活和纤维化。我们提出的研究将揭示HSF1介导的应力途径的作用和星状细胞活化和纤维化中的伴侣。