Novel mechanisms linking blood coagulation to liver fibrosis

将凝血与肝纤维化联系起来的新机制

• 批准号: 10722686
• 负责人: Lauren G Poole
• 金额: $ 24.9万
• 依托单位: RUTGERS BIOMEDICAL AND HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-01-01 至 2025-11-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10722686
• 关键词: Agonist; Automobile Driving; Blood Coagulation Factor; Blood coagulation; Carbon Tetrachloride; Cell physiology; Cells; Cicatrix; Clinical; Coagulation Process; Collagen; Deposition; Development; Discipline; Disease Progression; Event; Exogenous Factors; Factor VIIa; Factor XI; Factor XII; Foundations; Genetic; Goals; Hemostatic function; Hepatic Stellate Cell; Hepatology; In Vitro; Inflammation; Intrinsic drive; Ligands; Link; Liver Fibrosis; Liver diseases; Mediating; Membrane; Morbidity - disease rate; Mus; Mutant Strains Mice; Myofibroblast; Outcome; PAR-1 Receptor; Pathologic; Pathology; Pathway interactions; Patients; Peptide Hydrolases; Phenotype; Play; Prothrombin; Publishing; Research; Research Personnel; Research Proposals; Resolution; Role; Scheme; Signal Transduction; Testing; Thrombin; Thromboplastin; Thrombosis; Tissues; Toxicology; Up-Regulation; career; chronic liver disease; chronic liver injury; design; hepatotoxin; in vivo; liver injury; mortality; new therapeutic target; novel; novel therapeutics; pharmacologic; programs; receptor; skills; tissue injury; translational study

Project Summary/Abstract The overarching goal of this proposal is to develop the skills required to achieve my career goal of becoming an independent investigator with a research focus on the role of blood coagulation factors in cell signaling during tissue injury and inflammation. Accordingly, I have developed a Research Plan that will build a strong foundation for conducting research across disciplines in hepatology, toxicology, and thrombosis and hemostasis. Strong clinical and experimental evidence suggests that the blood coagulation cascade plays a pathologic role in the progression of hepatic fibrosis, i.e., “scarring” of the chronically injured liver. One hypothesis linking coagulation activity to hepatic fibrosis proposes that the coagulation protease thrombin drives hepatic stellate cells (HSCs) to a collagen-expressing myofibroblast phenotype by activating its primary receptor, protease-activated receptor- 1 (PAR-1). However, the precise mechanisms linking PAR-1 activation to the HSC pro-fibrotic phenotype are unknown. My central hypothesis is that thrombin activation of PAR-1 drives HSCs to a pro-fibrotic phenotype by amplifying the signaling functions of tissue factor (TF), the transmembrane receptor for coagulation factor VIIa (FVIIa). To test this hypothesis, I propose three Specific Aims. First, I will determine the mechanisms whereby PAR-1 activation drives a pro-fibrotic phenotype in hepatic stellate cells. I hypothesize that PAR-1 activation amplifies the HSC pro-fibrotic phenotype through induction of TF:FVIIa signaling. The role of TF:FVIIa signaling in PAR-1-mediated HSC activation will be determined using a combination of in vitro approaches including exogenous FVIIa treatment and HSCs lacking TF or PAR-2 (i.e., the receptor mediating TF:FVIIa signaling). The role of HSC TF in experimental hepatic fibrosis will be determined using novel mice with HSC-specific TF deficiency. Next, I will determine the role of thrombin:PAR-1 signaling in experimental hepatic fibrosis. The precise role of thrombin-mediated PAR-1 activation in hepatic fibrosis has never been investigated in vivo because PAR-1 can be cleaved by multiple proteases. I hypothesize that activation of PAR-1 by thrombin drives experimental hepatic fibrosis. To test this hypothesis, I will use a combination of strategies including mice expressing ~10% of normal prothrombin levels and novel mutant mice expressing PAR-1 that is selectively insensitive to cleavage at specific residues by thrombin or by other agonist proteases. Finally, I will identify the mechanisms driving coagulation activation in the injured liver. I hypothesize that coagulation activation in experimental CCl4-induced chronic liver injury is driven by the intrinsic coagulation pathway. I will use complementary genetic and pharmacologic approaches to determine the precise role of the extrinsic and intrinsic pathways of coagulation cascade activation in hepatic fibrosis driven by experimental chronic liver injury. The proposed studies will allow me to carve out a unique research niche investigating the cell signaling functions of blood coagulation factors, and would ultimately drive development of novel therapeutics which target local coagulation-mediated cell signaling events to reduce hepatic fibrosis with minimal impact on normal hemostasis.

项目摘要/摘要 该提案的总体目标是发展实现我的职业目标所需的技能 独立研究者研究着重于血液凝结因子在细胞信号传导中的作用 组织损伤和炎症。根据，我已经制定了一项研究计划，该计划将建立强大的基础 用于跨学科，毒理学，血栓形成和止血的研究。强的 临床和实验证据表明，血液凝结级联反应在 肝纤维化的进展，即长期受伤的肝脏的“疤痕”。一个假设连接凝血 肝纤维化的活性提案，即凝血蛋白凝血酶驱动肝星状细胞（HSC） 通过激活其主要受体，蛋白酶激活的受体 - 表达胶原蛋白表型的表型 1（par-1）。但是，将PAR-1激活与HSC促纤维化表型联系起来的精确机制是 未知。我的中心假设是，PAR-1的凝血酶激活将HSC驱动到促纤维化表型。 扩增组织因子（TF）的信号传导函数，即用于凝结因子VIIA的跨膜受体 （FVIIA）。为了检验这一假设，我提出了三个具体目标。首先，我将确定该机制 PAR-1激活驱动肝星状细胞中的促纤维化表型。我假设Par-1激活 放大器通过诱导TF：FVIIA信号传导HSC促纤维化表型。 TF：FVIIA信号的作用 在PAR-1介导的HSC激活中，将使用体外方法组合确定 缺乏TF或PAR-2的外源性FVIIA治疗和HSC（即受体介导TF：FVIIA信号传导）。 HSC TF在实验性肝纤维化中的作用将使用具有HSC特异性TF的新小鼠确定 不足。接下来，我将确定凝血酶：PAR-1信号在实验性肝纤维化中的作用。这 凝血酶介导的PAR-1激活在肝纤维化中的精确作用从未在体内研究 因为PAR-1可以被多种蛋白酶裂解。我假设通过凝血酶驱动器激活PAR-1 实验性肝纤维化。为了检验这一假设，我将使用包括小鼠在内的策略组合 表达约10％的正常凝血酶蛋白水平和表达PAR-1的新型突变小鼠 对凝血酶或其他激动剂蛋白酶在特定抗性下切割不敏感。最后，我将确定 驱动受伤的肝脏凝血激活的机制。我假设在 实验CCL4诱导的慢性肝损伤是由内在的凝血途径驱动的。我会用 完全遗传和药物的方法来确定外在和内在的精确作用 通过实验性慢性肝损伤，在肝纤维化中凝血级联激活的途径驱动。这 拟议的研究将使我得出一个独特的研究，研究细胞信号传导功能 血液凝血因素，并最终推动针对局部的新型治疗的发展 凝结介导的细胞信号传导事件可减少肝纤维化，对正常止血的影响最小。