Deciphering a Novel LncRNA-mediated Lipid Droplet Transport System in Human Heart

破译人类心脏中新型 LncRNA 介导的脂滴转运系统

• 批准号: 10640148
• 负责人: Lei Yang
• 金额: $ 55.79万
• 依托单位: INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2026-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10640148
• 关键词: 3-Dimensional; Adult; Cardiac; Cardiac Myocytes; Cardiomyopathies; Cells; Cessation of life; Clustered Regularly Interspaced Short Palindromic Repeats; Cytoskeleton; Development; Diabetes Mellitus; Dimensions; Disease; Down-Regulation; Engineering; Fatty Acids; Functional disorder; Future; Genetic Transcription; Goals; Heart; Heart failure; High Fat Diet; Human; Impairment; In Vitro; Incidence; Knock-out; Laboratories; Lipid Binding; Lipids; Mediating; Membrane; Metabolic syndrome; Mitochondria; Mitochondrial Swelling; Modeling; Molecular; Mus; Mutation; Myocardial dysfunction; Myocardium; Nonmuscle Myosin Type IIB; Obesity; Patients; Pharmaceutical Preparations; Phenocopy; Phospholipids; Play; Proteins; RNA; Research; Rodent Model; Role; System; Testing; Tissues; Transgenes; Transgenic Mice; Transgenic Organisms; Type 2 diabetic; Untranslated RNA; cardiogenesis; cardioprotection; diabetic; diabetic cardiomyopathy; diabetic patient; feeding; heart function; heart preservation; human pluripotent stem cell; in vitro Model; in vivo; induced pluripotent stem cell; insight; lipid metabolism; long chain fatty acid; mitochondrial dysfunction; monolayer; non-muscle myosin; non-muscle myosin heavy chain-B; novel; overexpression; oxidation; translational potential

Abstract The overarching goal of this proposal is to uncover novel HUMAN-SPECIFIC molecular mechanisms by which human long non-coding RNA (lncRNA) HL6 facilitates lipid droplet (LD) transport in human cardiomyocytes (CMs) and manifests a cardioprotective role against metabolic syndrome associated cardiomyopathy. ~70% energy of adult human heart is obtained from oxidation of long chain fatty acids (FAs). Balanced lipid metabolism is crucial for heart function. Compromised lipid metabolism have been widely observed in cardiomyopathies associated with metabolic syndromes, such as obesity and diabetes. The distinct features of obese and diabetes associated cardiomyopathy are increased incidence of heart failure together with extensive intramyocyte lipid droplet accumulation. LD consists of a neutral lipid core surrounded by a phospholipid monolayer, which plays a critical role in excess fatty acid storage and mobilization. However, overwhelmed intramyocyte LDs can cause cardiac lipotoxicity and dysfunction in both human patients and rodent models of obesity and diabetes. Although ample evidence suggests that LD accumulation in CMs could be due to impaired LD transport, the cellular system for LD transport in mammalian heart remains elusive. Particularly, the human-specific LD transport system of CMs and its implication in metabolic syndrome associated cardiomyopathy and heart failure remain unknown. Recently, we identified a human lncRNA, Heart LncRNA 6 (HL6), which is highly and specifically expressed in human CMs and downregulated in human type 2 diabetic myocardium. HL6 was knocked out (HL6KO) in human iPSCs (hiPSCs) by using CRISPR/Cas-9. We found HL6 deficiency led to extensive LD accumulation, defective LD transport to mitochondria, swollen mitochondria with impaired function, and enhanced CM death in HL6KO hiPSC-CMs verse WT hiPSC-CMs. Intriguingly, HL6 binds LDs and cytoskeleton in hiPSC-CMs. Additionally, transgenic HL6 overexpression significantly mitigated high fat diet (HFD)-induced lipid accumulation and cardiac dysfunction of mouse heart. Therefore, we hypothesize that HL6 plays an indispensable role in LD transport to mitochondria in human CMs, and gain-of-HL6 manifests a cardioprotective role against metabolic syndrome associated cardiomyopathy. Two specific aims are proposed: Specific Aim 1: Decipher the indispensable role of HL6 in lipid droplet transport of human CMs. Specific Aim 2: Determine the cardioprotective role of HL6 in metabolic syndrome associated cardiomyopathy.

抽象的 该提案的总体目标是揭示新的人类特异性分子机制 人类长的非编码RNA（LNCRNA）HL6促进人类心肌细胞（CMS）中的脂质液滴（LD）转运 并表现出针对代谢综合征相关心肌病的心脏保护作用。 〜70％的能量 成人人的心脏是从长链脂肪酸（FAS）的氧化中获得的。平衡脂质代谢至关重要 用于心脏功能。脂质代谢受损已被广泛观察到相关的心肌病 伴有代谢综合征，例如肥胖和糖尿病。与肥胖和糖尿病相关的独特特征 心肌病是心力衰竭的发病率增加以及广泛的内细胞脂质液滴 积累。 LD由一个被磷脂单层包围的中性脂质芯组成，该脂质的作用 在多余的脂肪酸储存和动员中的作用。但是，不知所措的内细胞内LD会导致心脏 肥胖和糖尿病的啮齿动物模型的脂肪毒性和功能障碍。虽然很丰富 有证据表明，LD在CMS中的积累可能是由于LD转运受损而引起的 哺乳动物心脏的LD运输仍然难以捉摸。特别是CMS的人类特异性LD运输系统 它与代谢综合征相关的心肌病和心力衰竭的影响仍然未知。 最近，我们确定了人类lncRNA，心lncrna 6（HL6），该lncrna在 人类CMS并在人类2型糖尿病心肌中下调。 HL6被淘汰（HL6KO） 使用CRISPR/CAS-9的人IPSC（HIPSC）。我们发现HL6缺乏导致了广泛的LD 积累，LD有缺陷到线粒体，线粒体肿胀，功能受损，并且 HL6KO HIPSC-CMS经文WT HIPSC-CMS中的CM死亡增强。有趣的是，HL6结合了LDS和 HIPSC-CMS中的细胞骨架。此外，转基因HL6过表达显着降低了高脂肪饮食 （HFD）诱导的脂质积累和小鼠心脏的心脏功能障碍。因此，我们假设HL6 在人类CMS中向线粒体运输中扮演着必不可少的作用，而HL6的收益表现为A 针对代谢综合征相关心肌病的心脏保护作用。提出了两个具体目标： 具体目标1：破译HL6在人CM的脂质液滴转运中必不可少的作用。具体目标2： 确定HL6在代谢综合征相关的心肌病中的心脏保护作用。