MicroRNAs regulating plasma LDL and HDL

MicroRNA 调节血浆 LDL 和 HDL

• 批准号: 10266009
• 负责人: M Mahmood Hussain
• 金额: --
• 依托单位: VA NEW YORK HARBOR HLTHCARE/SYS/BROOKLYN
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10266009
• 关键词: Affect; American; Anti-Inflammatory Agents; Antioxidants; Apolipoprotein E; Apolipoproteins B; Atherosclerosis; Binding; Binding Sites; Bioinformatics; Biological; Cardiovascular Diseases; Cells; Cholesterol; Collagen; Disease; Fatty Acids; Future; Gene Expression; Genes; Genetic Transcription; Glucose; Grant; Healthcare Systems; Hepatic; Hepatocyte; High Density Lipoprotein Cholesterol; High Density Lipoproteins; High Fat Diet; Hospitalization; Human; Libraries; Lipids; Lipoproteins; Low-Density Lipoproteins; Measures; Messenger RNA; MicroRNAs; Molecular; Mus; NCOR1 gene; Nature; Obesity; Oxidants; Pathway interactions; Pharmaceutical Preparations; Physiological; Plasma; Production; Protein Secretion; Proteins; RNA; Regulation; Risk Factors; Scaffolding Protein; Seeds; Small Interfering RNA; Smooth Muscle Myocytes; Testing; Therapeutic Agents; Tissues; Transaminases; Transcription Repressor; Untranslated RNA; Untranslated Regions; Weight Gain; Wild Type Mouse; cardiovascular risk factor; chemokine; cytokine; diet-induced obesity; experimental study; fatty acid oxidation; feeding; hepatoma cell; lipid metabolism; macrophage; novel; novel therapeutics; overexpression; oxidation; prediction algorithm; prevent; promoter; reverse cholesterol transport

Plasma high LDL and low HDL cholesterol levels are risk factors for cardiovascular diseases. MicroRNAs (miRs), small non-coding endogenous RNAs, target multiple pathways and regulate physiologic functions. Because miRs modulate diverse biological pathways, we hypothesized that miRs exist in nature that might simultaneously lower LDL and increase HDL. To discover them, we screened a human miRs library and identified miR-1200 that decreased apoB (LDL scaffold protein) and increased apoAI (major HDL protein) secretion from human hepatoma cells. We propose to find out how miR-1200 decreases apoB secretion, increases apoAI secretion, and enhances hepatic fatty acid oxidation (FAO) to modulate plasma lipoproteins and reduce atherosclerosis without causing hepatosteatosis in mice. Aim 1: Physiological mechanisms modulating plasma lipoproteins and atherosclerosis in mice. (A) We will interrogate the effects of miR-1200 on plasma lipoproteins and atherosclerosis in Apoe–/– and Ldlr–/– mice. Further comprehensive changes in weight gain, VO2, VCO2, activity and feeding parameters as well as in plasma lipids, lipoproteins, glucose, cytokines, chemokines and transaminases will be determined. Accretions of miR-1200 in different tissues and its consequences on target and control genes, hepatic lipids, lipid synthesis and fatty acid oxidation (FAO) will be studied. Additionally, we will evaluate whether miR-1200 is able to prevent diet induced obesity in wild type mice fed a high fat diet. (B) We will evaluate the hypothesis that miR-1200 regulates hepatic apoB and apoAI secretion to modulate plasma LDL and HDL levels. (C) We will test the hypothesis that miR-1200 modulates plasma LDL and HDL levels, and hepatic FAO by regulating APOB, BCL11B and NCOR1 gene expression. (D) We will ask if the elevated HDL is competent in cholesterol efflux and reverse cholesterol transport and is anti-inflammatory and anti- oxidant. We foresee that increasing hepatic miR-1200 levels will (1) reduce plasma LDL, (2) augment HDL, (3) increase reverse cholesterol transport, and (4) enhance FAO. Via these mechanisms, miR-1200 will reduce atherosclerosis and diet-induced obesity. Aim 2: Molecular mechanisms regulating lipid metabolism by miR-1200: (A) Mechanisms decreasing apoB secretion: We will (1) measure mRNA and protein levels in human primary hepatocytes transfected with miR-1200 or Control miR, (2) determine if miR-1200 interacts with seed sequence to enhance posttranscriptional degradation of apoB mRNA. (B) Mechanisms increasing apoAI secretion: We hypothesize that miR-1200 reduces BCL11B expression, a repressor, to increase ApoaI transcription. Experiments will be conducted to (1) establish that BCL11B is regulated by miR-1200, (2) demonstrate if BCL11B represses apoAI expression, (3) identify the binding site(s) for BCL11B in the ApoaI promoter, and (4) determine whether BCL11B binds less to the ApoaI promoter in miR-1200–expressing cells. These studies will identify a novel mechanism of regulating apoAI expression. (C) Mechanisms increasing FAO: We hypothesize that miR-1200 enhances FAO by repressing NCOR1, a repressor. We will establish that miR-1200 interacts with the 3ˊ-UTR of NCOR1 mRNA and enhances its degradation to increase FAO. Further, we will show that miR-1200 modulates the binding of NCOR1 to MCAD and CPT1 promoter. These studies will provide proof of concept that there are miRs that differentially regulate plasma lipoproteins. Further, they will explain molecular mechanisms involved in the regulation of plasma lipoproteins and hepatic FAO. These studies may show that miR-1200 can potentially lower or prevent diet- induced obesity and reduce atherosclerosis without causing steatosis and increasing plasma transaminases. These studies may point to the possibility that miR-1200 could be a potential drug to treat obesity and atherosclerosis.

血浆高 LDL 和低 HDL 胆固醇水平是心血管疾病的危险因素。 (miR) 是一种小型非编码内源性 RNA，靶向多种途径并调节生理功能。 由于 miR 调节不同的生物途径，我们帮助 miR 存在于自然界中， 可能同时降低 LDL 和增加 HDL 为了发现它们，我们筛选了人类 miR 库。 并鉴定出 miR-1200 可以减少 apoB（LDL 支架蛋白）并增加 apoAI（主要 HDL 蛋白） 我们建议找出 miR-1200 如何降低 apoB。 分泌，增加 apoAI 分泌，并增强肝脂肪酸氧化 (FAO) 以调节血浆 脂蛋白并减少动脉粥样硬化，而不引起小鼠肝脂肪变性。 目标 1：调节小鼠血浆脂蛋白和动脉粥样硬化的生理机制 (A)。 我们将探讨 miR-1200 对 Apoe–/– 和 Ldlr–/– 血浆脂蛋白和动脉粥样硬化的影响 小鼠体重增加、VO2、VCO2、活动和喂养参数的进一步全面变化。 如血浆脂质、脂蛋白、葡萄糖、细胞因子、趋化因子和转氨酶将被测定。 miR-1200 在不同组织中的积累及其对靶基因和控制基因、肝脏的影响 此外，我们还将研究脂质、脂质合成和脂肪酸氧化（FAO）。 miR-1200 能够预防高脂肪饮食的野生型小鼠因饮食引起的肥胖 (B) 我们将进行评估。 miR-1200 调节肝脏 apoB 和 apoAI 分泌从而调节血浆 LDL 和 (C) 我们将检验 miR-1200 调节血浆 LDL 和 HDL 水平的假设，以及 肝脏FAO通过调节APOB、BCL11B和NCOR1基因表达（D）我们将询问是否升高。 HDL 能够促进胆固醇流出和逆转胆固醇转运，并且具有抗炎和抗胆固醇作用。 我们预计，增加肝脏 miR-1200 水平将 (1) 降低血浆 LDL，(2) 增加 HDL， (3) 增加反向胆固醇转运，(4) 增强FAO 通过这些机制，miR-1200 将。 减少动脉粥样硬化和饮食引起的肥胖。 目标 2：miR-1200 调节脂质代谢的分子机制：(A) 减少的机制 apoB 分泌：我们将 (1) 测量转染的人原代肝细胞中的 mRNA 和蛋白质水平 与 miR-1200 或对照 miR 一起，(2) 确定 miR-1200 是否与种子序列相互作用以增强 apoB mRNA 的转录后降解 (B) 增加 apoAI 分泌的机制：我们。 miR-1200 会降低 BCL11B（一种阻遏物）的表达，从而增加 ApoI 转录。 将进行实验以 (1) 确定 BCL11B 受 miR-1200 调节，(2) 证明是否 BCL11B 抑制 apoAI 表达，(3) 识别 ApoI 启动子中 BCL11B 的结合位点，以及 (4) 确定 BCL11B 与 miR-1200 表达细胞中的 ApoI 启动子的结合是否较少。 研究将确定调节 apoAI 表达的新机制 (C) 增加FAO的机制： 我们敏锐地发现 miR-1200 通过抑制 NCOR1（一种阻遏蛋白）来增强FAO，我们将确定这一点。 miR-1200与NCOR1 mRNA的3ˊ-UTR相互作用并增强其降解从而增加FAO。 此外，我们将证明 miR-1200 调节 NCOR1 与 MCAD 和 CPT1 启动子的结合。 这些研究将提供概念证明，证明存在差异调节血浆的 miR 此外，他们还将解释参与血浆调节的分子机制。 这些研究可能表明 miR-1200 可以潜在地降低或预防饮食- 诱导肥胖并减少动脉粥样硬化，而不引起脂肪变性和增加血浆 这些研究可能表明 miR-1200 可能是一种潜在的治疗药物。 肥胖和动脉粥样硬化。