Acyl-CoA synthetase-mediated regulation of lipid homeostasis

酰基辅酶A合成酶介导的脂质稳态调节

• 批准号: 10189414
• 负责人: Michele Alves-Bezerra
• 金额: $ 12.72万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-06-01 至 2022-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10189414
• 关键词: Acyl Coenzyme A; Address; Anabolism; Biochemical; CRISPR/Cas technology; Cardiovascular Diseases; Cells; Clinical; Coenzyme A; Coenzyme A Ligases; Complex; Data; Dependovirus; Development; Diet; Disease; Drug or chemical Tissue Distribution; Dyslipidemias; Environment; Enzymes; Etiology; Exhibits; Fatty Acids; Fatty Liver; Genes; Genome engineering; Goals; Hepatic; Hepatocyte; Homeostasis; Human; Hypertriglyceridemia; In Vitro; Individual; Insulin Resistance; Knock-out; Knockout Mice; Knowledge; Life Style; Lipids; Liver; Liver diseases; Location; Mediating; Mentors; Metabolic; Metabolic Diseases; Metabolic Pathway; Metabolic syndrome; Metabolism; Molecular; Mus; Non-Insulin-Dependent Diabetes Mellitus; Nonesterified Fatty Acids; Obesity; Organ; Overnutrition; Pathogenesis; Pathogenicity; Pathology; Pathway interactions; Patients; Pharmacotherapy; Plasma; Prevention strategy; Protein Isoforms; Public Health; Reaction; Regulation; Research; Risk; Role; Signal Transduction; System; Testing; Therapeutic; Triglycerides; United States National Institutes of Health; Very low density lipoprotein; adeno-associated viral vector; career development; chronic liver disease; clinically relevant; comorbidity; design; experience; humanized mouse; in vivo; intrahepatic; lipid biosynthesis; lipid metabolism; long chain fatty acid; non-alcoholic fatty liver disease; novel; novel therapeutic intervention; obesity management; oxidation; preference; prevent; programs; response; skills; targeted treatment; training opportunity; uptake

PROJECT SUMMARY / ABSTRACT Systemic lipid homeostasis is controlled by the liver via complex but precisely regulated biochemical, signaling, and cellular pathways. In obesity, hepatic lipid metabolism is altered, commonly leading to the pathogenic accumulation of triacylglycerol and to a spectrum of liver disorders known as non-alcoholic fatty liver disease (NAFLD). NAFLD is considered the hepatic manifestation of metabolic syndrome; as such, it often occurs in a setting of insulin resistance and is associated with type 2 diabetes, dyslipidemia, and cardiovascular disease. It is the most prevalent chronic liver disease worldwide, for which there is no approved pharmacotherapy. The etiology of NAFLD is still unclear and advances in understanding the molecular mechanisms leading to hepatic triacylglycerol accumulation are critical to the development of targeted therapies. Within the hepatocyte, free fatty acid molecules experience one of several metabolic fates, including synthesis of complex lipids and oxidation. An obligatory step in the metabolism of long-chain fatty acids is its activation by thioesterification to CoA to form acyl-CoA. This reaction is catalyzed by the acyl-CoA synthetase (ACSL) enzymes. The specific tissue distributions, subcellular locations, and substrate preferences suggest that individual ACSL isoforms have distinct metabolic functions in partitioning acyl-CoAs into specific metabolic pathways. ACSL3 and ACSL5 isoforms are highly expressed in human and murine livers and studies in cell systems suggest that these enzymes promote lipogenesis. However, to date, the metabolic roles of ACSL3 and ACSL5 in the liver in vivo remain unresolved. We hypothesize that ACSL3 and ACSL5 function in the liver to direct acyl-CoA towards lipid synthesis and away from oxidative pathways, thereby promoting hepatic triacylglycerol accumulation and VLDL secretion. In Aim 1, we will use AAV-CRISPR/Cas9 technology to generate the first liver-specific knockout mice for Acsl3 and Acsl5 to test the hypothesis that ACSL3 and ACSL5 activities in the liver contribute to the synthesis of triacylglycerol, which in turn leads to hepatic steatosis and hypertriglyceridemia. In Aim 2, we will establish the roles of ACSL3 and ACSL5 in human NAFLD pathogenesis by using AAV-CRISPR/Cas9 to achieve liver-specific knockout of ACSL3 and ACSL5 in human liver chimeric mice. The proposed research delineates hepatocellular basis contributing to the progression of metabolic diseases, which is clinically important as it provides new targets for the management of obesity-related disorders such as NAFLD and dyslipidemia. In addition, this project provides an intensive research career development training opportunity under the guidance of experienced mentors in an outstanding scientific environment. This will allow me to consolidate and launch my independent research program dedicated to the understanding of the molecular basis for human metabolic disorders. The successful completion of these studies will: (i) provide me with knowledge and skills in liver-targeted genome engineering and its application to clinically relevant human liver disorders; and (ii) inform an NIH R01 application for the study of pathophysiological mechanisms that regulate hepatic lipid homeostasis.

项目总结/摘要 全身脂质稳态由肝脏通过复杂但精确调节的生化信号传导控制， 和细胞途径。在肥胖症中，肝脏脂质代谢改变，通常导致致病性 三酰甘油的积累和一系列称为非酒精性脂肪性肝病的肝脏疾病 （NAFLD）。NAFLD被认为是代谢综合征的肝脏表现;因此，它经常发生在一个 胰岛素抵抗的发生与2型糖尿病、血脂异常和心血管疾病有关。它 是世界上最普遍的慢性肝病，目前还没有批准的药物治疗。的 NAFLD的病因仍不清楚，在理解导致肝纤维化的分子机制方面取得了进展。 三酰甘油积累对靶向治疗的发展至关重要。在肝细胞内，游离 脂肪酸分子经历几种代谢命运之一，包括合成复合脂质， 氧化长链脂肪酸代谢中的一个必要步骤是通过硫代酯化作用活化， CoA形成酰基-CoA。该反应由酰基辅酶A合成酶（ACSL）催化。具体 组织分布、亚细胞位置和底物偏好表明，单个ACSL亚型具有 在将酰基辅酶A分配到特定的代谢途径中具有不同的代谢功能。ACSL 3和ACSL 5 同种型在人和鼠的肝脏中高度表达，并且细胞系统中的研究表明，这些同种型 酶促进脂肪生成。然而，迄今为止，ACSL 3和ACSL 5在体内肝脏中的代谢作用 仍然没有解决。我们假设ACSL 3和ACSL 5在肝脏中起作用，将酰基辅酶A导向脂质， 合成和远离氧化途径，从而促进肝脏甘油三酯积累和VLDL 分泌物在目标1中，我们将使用AAV-CRISPR/Cas9技术产生第一个肝脏特异性敲除小鼠 对于Acsl 3和Acsl 5，以检验ACSL 3和ACSL 5在肝脏中的活性有助于合成的假设 三酰甘油，这反过来又导致肝脂肪变性和高甘油三酯血症。在目标2中，我们将建立 ACSL 3和ACSL 5在人类NAFLD发病机制中的作用，通过使用AAV-CRISPR/Cas9来实现肝脏特异性 在人肝嵌合小鼠中敲除ACSL 3和ACSL 5。拟议的研究描绘了肝细胞 基础有助于代谢疾病的进展，这是临床上重要的，因为它提供了新的目标 用于管理肥胖相关疾病，如NAFLD和血脂异常。此外，该项目 提供了一个密集的研究职业发展培训的机会，在经验丰富的指导下， 导师在一个优秀的科学环境。这将使我能够巩固和推出我的独立 致力于了解人类代谢障碍分子基础的研究项目。的 成功完成这些研究将：（i）为我提供肝脏靶向基因组方面的知识和技能 工程及其在临床相关人类肝脏疾病中的应用;以及（ii）通知NIH R 01申请 用于研究调节肝脏脂质稳态的病理生理学机制。