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.

抽象的。心血管疾病是全球死亡的主要原因。药理学的主要目标 疗法是降低血浆脂质，尤其是低密度脂蛋白胆固醇（LDL），这是基本的脂质（LDL），这是基本危险因素 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LDL从循环和血浆水平升高而导致的早发CAD导致的早发CAD 这种动脉粥样硬化脂蛋白。有限的治疗性诊断不足和FH治疗不足会加剧 选项。但是，一种策略成功地降低了FH患者的LDL：抑制肝 分泌的蛋白质血管生成素样蛋白3（ANGPTL3）。抑制单克隆抗体（EVINACUMAB） 循环ANGPTL3最近获得了FDA批准以治疗FH，这是由于LDL的大量降低， 即使在LDL受体（LDLR）完全缺乏的患者中。相反，现有的降脂剂 在很大程度上依赖LDLR功能来从血液中去除这种动脉粥样硬化脂蛋白。按照 NHLBI研究的重点，对于研究人员而言，定义可以预测的分子特征很重要 在患有心血管疾病的不同人群中，有意义或不充分对治疗的反应。尽管 有前途的临床试验数据，LDLR独立的机制，通过该数据，ANGPTL3抑制剂降低了LDL 没有充分表征。这是一个重要的问题，不仅要描述药物如何抑制 ANGPTL3工作，但也建议通过新型LDLR依赖性途径减少血浆脂质的目标 脂蛋白代谢。该提议的主要假设是ANGPTL3缺乏症部分降低了LDL 通过调节肝脂蛋白组装和脂质代谢，同时改变特征 分泌的VLDL颗粒。通过实现本提议中概述的目标，将解决这一假设。这 提出的实验采用了肝细胞细胞培养系统的组合，包括永生的癌症 细胞和晚期细胞培养模型，该模型从诱导的多能产生肝细胞样细胞（HLC） 干细胞（IPSC）。这些IPSC来自具有完整遗传的独特人群 Angptl3缺乏。 AIM 1将使用这些模型来测试脂蛋白分泌过境和/或的变化是否 脂质代谢有助于降低ANGPTL3缺乏症的LDL。 AIM 2将测试脂蛋白颗粒是否 分泌动力学，清除率，大小和/或脂质组成也可能导致LDL降低。这些 实验将作为严格的研究金培训计划的一部分进行，以良好的资源良好 协作环境。与NHLBI战略计划一致，拟议的研究将帮助未来 通过提高对Angptl3-功能的了解，临床医生评估及其服务的患者 抑制药物；描述Angptl3在肝脂蛋白代谢中的作用；并可能推荐 通过阐明无DLR独立的机制来降低脂质剂的新治疗靶标 循环的LDL。