Lysosome Trafficking Dysregulation of Arterial Myocytes in Atherogenesis

动脉粥样硬化中动脉肌细胞的溶酶体运输失调

• 批准号: 8842197
• 负责人: PinLan Li
• 金额: $ 9.37万
• 依托单位: VIRGINIA COMMONWEALTH UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-04-01 至 2015-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8842197
• 关键词: 7-ketocholesterol; Abbreviations; Acrosome; Address; Applications Grants; Arteries; Atherosclerosis; Autophagocytosis; Autophagolysosome; Autophagosome; Bacteria; Binding; Blood Vessels; Cells; Ceramide Signaling Pathway; Ceramides; Coronary; Coronary artery; Defect; Development; Diet; Disease; Dynein ATPase; Endocytosis; Enzymes; Exocytosis; Extracellular Matrix; Failure; Fertilization; Fluorescence Resonance Energy Transfer; Foam Cells; Functional disorder; Genes; Health; Heart; Hydrolysis; In Vitro; Inflammation; Injury; Lead; Lipids; Lysosomes; Mammalian Cell; Mediating; Membrane; Membrane Proteins; Microtubules; Molecular; Motor; Movement; Mus; Muscle Cells; Mutation; Myocardial Infarction; Names; Niemann-Pick Diseases; Organelles; Pathogenesis; Pathway interactions; Patients; Phagocytosis; Physiological; Play; Predisposition; Prevention; Production; Proteins; Regulation; Reporting; Role; Signal Pathway; Signal Transduction; Sirolimus; Smooth Muscle Myocytes; Sphingomyelins; Stimulus; Testing; Time; Vascular Diseases; Vesicle; Work; acid sphingomyelinase; atherogenesis; bafilomycin A1; emerging adult; hypercholesterolemia; in vivo; insight; new therapeutic target; novel therapeutics; nuclear pore protein p62; oocyte maturation; receptor; receptor recycling; repaired; trafficking; wasting; western diet

DESCRIPTION (provided by applicant): Lysosome trafficking has been implicated in a number of cellular activities such as phagocytosis to protect mammalian cells from foreign invaders like bacteria, autophagy to keep these cells surviving or robust, and cellular signaling related to receptor recycling, Ca2+ release and membrane repairing. So far little is known how such lysosome trafficking and associated autophagic flux are regulated in the vasculature. Recent studies have demonstrated that ceramide, a hydrolysis product of sphingomyelin by lysosomal acid sphingomyelinase (ASM), contributes to the control of lysosome functions in coronary arterial smooth muscle cells (CASMCs) and coronary arterial function. Clinically, genetic defects of ASM lead to the lysosomal accumulation of sphingomyelin and a lysosomal storage disorder named Niemann-Pick disease. These Niemann-Pick disease patients are susceptible to the development of atherosclerosis in early adulthood, suggesting that the pathogenesis of atherosclerosis may be associated with the abnormality of ASM-ceramide-mediated regulation of lysosome function. In this grant proposal, our hypothesis is that ASM-ceramide signaling pathway plays a critical tonic regulatory role in lysosome trafficking and autophagic flux in CASMCs and the deficiency of this lysosome regulation may be an important atherogenic mechanism. We will first address whether lysosomal ASM and its product ceramide in CASMCs contribute to the control of lysosome trafficking and associated autophagic flux upon proatherogenic stimulations and to explore the molecular mechanisms by which ASM- ceramide signaling pathway controls lysosome trafficking and fusion (Aim 1). Then, we will determine whether the defect of ASM leads to atherosclerotic injury in coronary arterial wall due to dysregulation of lysosome trafficking and retention of autophagic vesicles using Asm-/- mice and their wild type littermates (Aim 2). Lastly, we will examine how dysregulation of lysosome trafficking and consequent failure of autophagic flux induce atherogenic changes in CASMCs in vitro and in coronary arterial wall in vivo using As--/- mice and their wild type littermates (Aim ). This grant application will for the first time address the molecular mechanisms that actively regulate lysosome trafficking and function via ASM/ceramide pathway in CASMCs and the physiological and pathological relevance to vascular regulation and atherosclerosis. The findings from this proposal will provide new insights into the tonic regulation of lysosome function and the possible pathological relevance to vascular diseases, which may help identify new therapeutic targets for treatment and prevention of atherosclerosis.

描述（由申请人提供）：溶酶体运输涉及许多细胞活动，例如保护哺乳动物细胞免受细菌等外来入侵者的吞噬作用、保持这些细胞存活或健壮的自噬作用，以及与受体再循环、Ca2+释放和膜修复相关的细胞信号传导。迄今为止，人们对这种溶酶体运输和相关自噬流在脉管系统中是如何调节的知之甚少。 Recent studies have demonstrated that ceramide, a hydrolysis product of sphingomyelin by lysosomal acid sphingomyelinase (ASM), contributes to the control of lysosome functions in coronary arterial smooth muscle cells (CASMCs) and coronary arterial function.临床上，ASM的遗传缺陷导致鞘磷脂在溶酶体中积聚，并出现称为尼曼-匹克病的溶酶体贮积症。这些尼曼-匹克病患者在成年早期容易发生动脉粥样硬化，这表明动脉粥样硬化的发病机制可能与ASM神经酰胺介导的溶酶体功能调节异常有关。在这项资助提案中，我们的假设是，ASM-神经酰胺信号通路在 CASMC 的溶酶体运输和自噬流中发挥着关键的调节作用，这种溶酶体调节的缺陷可能是一个重要的动脉粥样硬化机制。我们将首先解决 CASMC 中溶酶体 ASM 及其产物神经酰胺是否有助于控制促动脉粥样硬化刺激下的溶酶体运输和相关自噬流，并探讨 ASM-神经酰胺信号通路控制溶酶体运输和融合的分子机制（目标 1）。然后，我们将使用 Asm-/- 小鼠及其野生型同窝小鼠确定 ASM 缺陷是否会因溶酶体运输失调和自噬囊泡保留而导致冠状动脉壁动脉粥样硬化损伤（目标 2）。最后，我们将使用 As-/- 小鼠及其野生型同窝小鼠研究溶酶体运输失调和随之而来的自噬流失败如何在体外诱导 CASMC 和体内冠状动脉壁发生动脉粥样硬化变化（目的）。该拨款申请将首次解决 CASMC 中通过 ASM/神经酰胺途径主动调节溶酶体运输和功能的分子机制，以及与血管调节和动脉粥样硬化的生理和病理相关性。该提案的研究结果将为溶酶体功能的强直调节以及与血管疾病可能的病理相关性提供新的见解，这可能有助于确定治疗和预防动脉粥样硬化的新治疗靶点。