LncRNA MAARS, macrophage apoptosis, and atherosclerosis

LncRNA MAARS、巨噬细胞凋亡和动脉粥样硬化

• 批准号: 10214694
• 负责人: MARK W FEINBERG
• 金额: $ 41.59万
• 依托单位: BRIGHAM AND WOMEN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-07-15 至 2024-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10214694
• 关键词: Address; Affect; Apoptosis; Apoptosis Regulation Gene; Apoptotic; Arterial Fatty Streak; Atherosclerosis; Attention; Biological Assay; Biological Process; Biophysics; Bone Marrow; CASP3 gene; Carotid Artery Diseases; Cause of Death; Cell Death; Cell physiology; Cells; Characteristics; Chromatin Remodeling Factor; Chronic; Cleaved cell; Code; Data; Deletion Mutation; Dependence; Detection; Disease; Disease Progression; Event; Foundations; Genes; Goals; Homologous Gene; Human; In Vitro; Kinetics; Knockout Mice; Lesion; Link; Lipids; Longitudinal Studies; Mediating; Molecular; Mus; Myocardial Infarction; Necrosis; Nuclear; Peripheral Blood Mononuclear Cell; Peripheral Vascular Diseases; Phase; Play; Poly A; Process; Proteins; RNA; RNA Sequences; RNA-Binding Proteins; Regulation; Role; Signal Pathway; Signal Transduction; Splenocyte; Stains; Stimulus; Stroke; Therapeutic; Untranslated RNA; Vascular Diseases; Work; atherogenesis; base; genetic signature; improved; in vivo; inhibitor/antagonist; insight; knock-down; mRNA Stability; macrophage; new therapeutic target; novel; novel therapeutic intervention; trafficking; transcriptome sequencing

Atherosclerosis, a chronic arterial disease, involves multiple cellular processes including the accumulation of intimal macrophages. Macrophage apoptosis is increased with progression of atherosclerosis, leading to increased cell death and accumulation of cellular debris. This in turn may abrogate macrophage efferocytosis, an important event for clearance of apoptotic or necrotic cells. Therefore, improving the efficiency of macrophages in the clearance of intra-lesional cellular debris may provide a novel therapeutic approach to limit atherosclerotic progression. Long non-coding RNAs (lncRNAs) have garnered widespread attention as emerging regulators of diverse biological processes relevant to atherosclerosis. However, the identity and roles of specific lncRNAs within atherosclerotic lesions are not well defined. Using RNA-Seq profiling to identify lncRNAs derived specifically from the aortic intima of LDLR-/- mice during lesion progression and regression phases, we identify the lncRNA MAARS (Macrophage-Associated Atherosclerosis lncRNA Sequence). MAARS was the highest expressed lncRNA with a 300-fold increase after lesion progression and decreased by 70% with regression. MAARS is a polyadenylated, macrophage- and nuclear-specific, lncRNA. Kinetic studies showed that MAARS expression is markedly induced in macrophages differentiated from bone marrow, PBMCs, or splenocytes. Our preliminary data demonstrate that systemic delivery of inhibitors to MAARS strongly reduced lesion size, independent of effects on circulating lipid profile, but rather by decreased macrophage apoptosis and increased efferocytosis in the vessel wall. Deficiency of MAARS reduced macrophage apoptosis induced by different stimuli and increased macrophage efferocytosis in vitro. Mechanistically, lncRNA pulldown assays in combination with LC-MS/MS analysis showed that MAARS interacts with HuR, an RNA-binding protein and important regulator of apoptosis. Preliminary studies show that HuR silencing increases macrophage apoptosis and that the MAARS-mediated effects on macrophage apoptosis may be HuR dependent. In addition, MAARS knockdown altered HuR nuclear-cytoplasmic trafficking, and regulated important apoptotic genes. These observations provide the foundation for the central hypothesis that MAARS deficiency, via regulatory effects on HuR and specific macrophage apoptotic signaling pathways, reduces macrophage apoptosis, improves cellular efferocytosis, and suppresses atherosclerosis. To address this further, in Aim1 we examine the role of MAARS in regulating HuR-mediated macrophage apoptosis and efferocytosis; in Aim2, we assess how alterations of MAARS expression affects short- and long-term atherosclerosis in vivo; and in Aim3, we examine the role of the MAARS-HuR signaling axis in human cells and atherosclerotic lesions. Our studies will address a major gap in our understanding of lncRNAs in atherosclerosis and inform how MAARS-mediated control of macrophage apoptosis and efferocytosis may provide new targets for therapy.

动脉粥样硬化是一种慢性动脉疾病，涉及多个细胞过程，包括积聚 内膜巨噬细胞。巨噬细胞凋亡随着动脉粥样硬化的进展而增加，导致 增加了细胞死亡和细胞碎片的积累。这反过来可能会消除巨噬细胞的泡沫化作用， 清除凋亡或坏死性细胞的重要事件。因此，提高工作效率 巨噬细胞在清除皮损内细胞碎片方面可能提供一种新的治疗方法 动脉粥样硬化进展。 长非编码RNA(LncRNAs)作为一种新兴的基因调控因子，受到了广泛的关注 与动脉粥样硬化相关的多种生物学过程。然而，特定的lncRNAs的身份和作用 动脉粥样硬化内的病变没有很好的界定。利用RNA-Seq图谱鉴定衍生的LncRNA 从LDLR-/-小鼠病变进展和消退阶段的主动脉内膜中，我们识别出 LncRNA MAARS(巨噬细胞相关动脉粥样硬化基因序列)。马尔斯是最高的 病变进展后，lncRNA表达增加300倍，消退后减少70%。 MAARS是一种多聚腺化、巨噬细胞和核特异性的lncRNA。动力学研究表明，MAARS 由骨髓、PBMCs或脾细胞分化而来的巨噬细胞可显著诱导其表达。 我们的初步数据显示，系统地向MAARS递送抑制剂显著减少了病变大小， 不依赖于对循环血脂的影响，而是通过减少巨噬细胞的凋亡和 血管壁泡出增多。MAARS缺陷可减少MARS诱导的巨噬细胞凋亡 不同刺激物对巨噬细胞体外泡出能力的影响。从机制上讲，lncRNA下拉分析 结合LC-MS/MS分析表明，MAARS与HUR相互作用，HUR是一种RNA结合蛋白， 重要的细胞凋亡调节因子。初步研究表明，HUR沉默增加了巨噬细胞的凋亡 MAARS介导的巨噬细胞凋亡效应可能是HUR依赖性的。此外，MAARS 基因敲除改变了HUR的核质运输，并调节了重要的凋亡基因。这些 观察结果为中心假说提供了基础，即MAARS缺陷是通过对 HUR和特异性巨噬细胞凋亡信号通路，减少巨噬细胞凋亡，改善细胞 泡腾作用，抑制动脉粥样硬化。为了进一步解决这个问题，在Aim1中，我们研究了MAARS的作用 在调节HUR介导的巨噬细胞凋亡和泡沫化过程中；在AIM2中，我们评估了 在体内，MAARS的表达影响短期和长期的动脉粥样硬化；在Aim3中，我们研究了MAARS的作用 人类细胞和动脉粥样硬化病变中的MAARS-HUR信号轴。我们的研究将解决一个主要问题 我们对动脉粥样硬化中lncRNAs的理解存在差距，并揭示了MAARS如何介导对 巨噬细胞的凋亡和吞噬作用可能为治疗提供新的靶点。