Effects of Genetic ANGPTL3 Deficiency on Hepatic Lipid Regulation and Lipoprotein Production

遗传性 ANGPTL3 缺陷对肝脏脂质调节和脂蛋白产生的影响

• 批准号: 10605624
• 负责人: Kendall Helene Burks
• 金额: $ 3.36万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-05-01 至 2025-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10605624
• 关键词: Address; Affect; Alleles; Angiopoietins; Apolipoproteins B; CRISPR/Cas technology; Cardiovascular Diseases; Cause of Death; Cell Culture System; Cell Culture Techniques; Cell secretion; Cells; Characteristics; Chemicals; Cholesterol; Cholesterol Homeostasis; Circulation; Clinical; Clinical Trials; Coronary Arteriosclerosis; Culture Media; Data; Diagnosis; Dyslipidemias; Elements; FDA approved; Familial Hypercholesterolemia; Fellowship; Follow-Up Studies; Future; Genes; Genetic; Goals; HepG2; Hepatic; Hepatocyte; Homeostasis; Human; Hyperlipidemia; Impairment; Kinetics; Knock-out; Knowledge; LDL Cholesterol Lipoproteins; Label; Lipase; Lipids; Lipolysis; Lipoproteins; Liver; Loss of Heterozygosity; Mass Spectrum Analysis; Measures; Metabolism; Modeling; Molecular; Monoclonal Antibodies; National Heart, Lung, and Blood Institute; Participant; Particle Size; Pathway interactions; Patients; Peripheral; Pharmaceutical Preparations; Phenotype; Physiologic pulse; Plasma; Play; Pluripotent Stem Cells; Population; Production; Protein Secretion; Proteins; Publishing; Radiolabeled; Reagent; Recommendation; Refractory; Regulation; Research; Research Personnel; Research Priority; Resources; Risk; Risk Factors; Role; Strategic Planning; System; Testing; Therapeutic; Training; Triglycerides; Variant; Very low density lipoprotein; Work; blood lipoprotein; cancer cell; cardioprotection; cardiovascular risk factor; collaborative environment; derepression; disorder risk; drug development; early onset; experimental study; genome editing; human monoclonal antibodies; human stem cells; human subject; hypolipidemia; improved; induced pluripotent stem cell; inhibiting antibody; insight; ion mobility; lipid metabolism; lipidomics; loss of function; new therapeutic target; novel; particle; pharmacologic; prevent; receptor; receptor function; reuptake; stem cell differentiation; therapeutic target; transcriptome sequencing; treatment response; uptake

ABSTRACT. Cardiovascular disease is the leading cause of death worldwide. A major goal of pharmacologic therapy is to lower plasma lipids, especially low-density lipoprotein cholesterol (LDL), the cardinal risk factor for coronary artery disease (CAD). Patients with familial hypercholesterolemia (FH) have increased risk of developing early-onset CAD due to dysfunctional clearance of LDL from circulation and increased plasma levels of this atherogenic lipoprotein. Underdiagnosis and undertreatment of FH are exacerbated by limited therapeutic options. However, one strategy has been successful at lowering LDL in FH patients: Inhibition of the hepatically secreted protein Angiopoietin-like protein 3 (ANGPTL3). A monoclonal antibody (evinacumab) inhibiting circulating ANGPTL3 recently obtained FDA approval for treatment of FH due to substantial reductions in LDL, even in patients with complete deficiency of the LDL receptor (LDLR). In contrast, existing lipid-lowering agents largely rely on LDLR function to remove this atherogenic lipoprotein from the blood. In accordance with the NHLBI Research Priorities, it is important for researchers to define molecular characteristics that can predict meaningful or inadequate responses to therapy in different populations with cardiovascular disease. Despite promising clinical trial data, the LDLR-independent mechanisms by which ANGPTL3 inhibition lowers LDL have not been fully characterized. This is an important question to address not only to describe how drugs inhibiting ANGPTL3 work but also to recommend targets for reducing plasma lipids via a novel LDLR-independent pathway of lipoprotein metabolism. The main hypothesis of this proposal is that ANGPTL3 deficiency lowers LDL in part by modulating hepatic lipoprotein assembly and lipid metabolism while simultaneously altering characteristics of secreted VLDL particles. This hypothesis will be addressed by achieving the goals outlined in this proposal. The proposed experiments employ a combination of hepatocyte cell culture systems, including immortalized cancer cells and an advanced cell culture model that produces hepatocyte-like cells (HLCs) from induced pluripotent stem cells (iPSCs). These iPSCs are derived from a unique population of human subjects with complete genetic ANGPTL3 deficiency. Aim 1 will use these models to test whether changes in lipoprotein secretory transit and/or lipid metabolism contribute to LDL lowering in ANGPTL3 deficiency. Aim 2 will test whether lipoprotein particle secretion kinetics, clearance, size, and/or lipid composition could also be contributing to LDL lowering. These experiments will be carried out as part of a rigorous fellowship training plan in a well-resourced and highly collaborative environment. Consistent with the NHLBI Strategic Plan, the proposed studies will help future clinician-investigators and the patients they serve by improving understanding of the functions of ANGPTL3- inhibiting drugs; describing a role for ANGPTL3 in hepatic lipoprotein metabolism; and potentially recommending new therapeutic targets for lipid-lowering agents by elucidating an LDLR-independent mechanism for clearance of circulating LDL.

摘要。心血管疾病是全世界死亡的主要原因。药理学的一个主要目标 治疗是降低血脂，特别是低密度脂蛋白胆固醇（LDL），这是糖尿病的主要危险因素。 冠状动脉疾病（CAD）。家族性高胆固醇血症（FH）患者的风险增加， 由于循环中LDL清除功能障碍和血浆水平升高而发生早发性CAD 这种致动脉粥样硬化的脂蛋白。FH的诊断不足和治疗不足因有限的治疗而加剧 选项.然而，有一种策略在降低FH患者的LDL方面取得了成功： 分泌蛋白血管生成素样蛋白3（ANGPTL 3）。一种单克隆抗体（evinacumab）， 循环ANGPTL 3最近由于LDL的显著降低而获得FDA批准用于治疗FH， 甚至在LDL受体（LDLR）完全缺乏的患者中。相比之下，现有的降脂剂 在很大程度上依赖于LDLR功能从血液中清除这种致动脉粥样硬化的脂蛋白。根据本 NHLBI研究优先事项，重要的是研究人员定义分子特征，可以预测 不同心血管疾病人群对治疗的反应是否有意义或不充分。尽管 有希望的临床试验数据，ANGPTL 3抑制降低LDL的LDLR非依赖性机制， 还没有完全定性。这是一个重要的问题，不仅要描述药物如何抑制 ANGPTL 3不仅有效，而且还推荐通过新型LDLR非依赖性途径降低血脂的靶点 脂蛋白代谢。该建议的主要假设是ANGPTL 3缺乏部分降低LDL 通过调节肝脂蛋白组装和脂质代谢，同时改变 分泌的VLDL颗粒。这一假设将通过实现本提案中概述的目标来解决。的 提出的实验采用肝细胞培养系统的组合，包括永生化的癌症 细胞和从诱导多能细胞产生肝细胞样细胞（HLC）的先进细胞培养模型 干细胞（iPSC）。这些iPSC来源于具有完整遗传学特性的人类受试者的独特群体。 ANGPTL 3缺陷。目的1将使用这些模型来测试脂蛋白分泌转运和/或 脂质代谢有助于ANGPTL 3缺乏时LDL降低。目的2将测试脂蛋白颗粒是否 分泌动力学、清除率、大小和/或脂质组成也可能有助于LDL降低。这些 实验将作为严格的研究金培训计划的一部分，在一个资源充足、高度 协作环境。与NHLBI战略计划一致，拟议的研究将有助于未来 临床研究者和他们所服务的患者通过提高对ANGPTL 3功能的理解- 抑制药物;描述ANGPTL 3在肝脂蛋白代谢中的作用;并可能推荐 通过阐明LDLR非依赖性清除机制的降脂药新治疗靶点 循环中的LDL