Macrophage small RNA export to HDL protects against inflammation and atherosclerosis

巨噬细胞向 HDL 输出小 RNA 可预防炎症和动脉粥样硬化

• 批准号: 10544065
• 负责人: Kasey C Vickers
• 金额: $ 38.93万
• 依托单位: VANDERBILT UNIVERSITY MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-06-01 至 2025-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10544065
• 关键词: Agonist; Apolipoprotein E; Area; Arterial Fatty Streak; Atherosclerosis; Attenuated; Binding; Biological Process; Cardiometabolic Disease; Cardiovascular Diseases; Cells; Chronic; Circulation; Complex; Deposition; Disease; Endocytosis; Environment; Functional disorder; Gene Expression; High Density Lipoproteins; Human; Immune; Impairment; In Vitro; Inflammation; Inflammatory; Ischemia; Knowledge; Lesion; Lipids; Lipoproteins; Literature; Low-Density Lipoproteins; Macrophage; Macrophage Activation; Mediating; MicroRNAs; Modeling; Modification; Mus; Pathology; Pathway interactions; Phagocytosis; Phenotype; Process; Property; RNA Transport; Receptor Activation; Reporting; Repression; Route; Signal Transduction; Small RNA; Stimulus; TLR7 gene; TLR8 gene; Testing; Therapeutic; Toll-like receptors; Untranslated RNA; Work; cytokine; extracellular; field study; human disease; in vivo; inhibitor; lipid metabolism; locked nucleic acid; microbial; microbiome; mouse model; novel; nucleic acid inhibitor; nucleic acid-based therapeutics; particle; receptor; response; single-cell RNA sequencing; therapy design; uptake; western diet

Summary: Atherosclerosis is the underlying cause for ischemic cardiovascular disease (CVD), a pathology best characterized as uncontrolled inflammation in response to continual lipid deposition in the arterial wall. Despite the importance of inflammation in the progression of atherosclerosis, very few therapies are designed to target this process due to a general lack of knowledge of atherogenic stimuli outside of bioactive lipids. Previously, we have reported that lipoproteins, namely HDL and LDL, transport small non-coding RNAs (sRNA), and recently, we discovered that lipoproteins are highly-enriched with sRNAs derived from bacterial and fungal species in the microbiome and environment. Interestingly, these foreign, microbial sRNAs (msRNAs) are also highly-abundant in macrophages within the atherosclerotic lesions and activate sRNA-sensing toll-like receptors (TLR)7/8 in lesion macrophages. We posit that HDL accepts msRNAs from lesion macrophages, and thus, suppresses TLR7/8 activation and down-stream pro-inflammatory gene expression. Supporting this model, macrophages were found to readily export msRNAs to HDL and HDL treatments were found to block msRNA-induced activation. In CVD, HDL acquire reactive dicarbonyl modifications which are associated with HDL dysfunction. In preliminary studies, we found that reactive dicarbonyl modifications on HDL, e.g. isolevuglandins (IsoLG), impair HDL-msRNA export. Moreover, we found that IsoLG-modified HDL had increased macrophage uptake and retention and induced pro-inflammatory gene expression. Preliminary studies also found that treating mouse models with reactive scavengers to block IsoLG modifications decreased atherosclerosis. Therefore, we aimed to block msRNA activation of TLR7/8 using non-targeting locked-nucleic acids (ntLNA). Strikingly, we found that ntLNA treatments significantly reduced atherosclerotic lesion area by 30% over 4 weeks in Apoe-/- mice on western diet. In addition, single-cell RNA sequencing approaches demonstrated that ntLNA therapy repressed pro-inflammatory gene expression in lesion macrophages and reduced the number of pro-inflammatory macrophages in atherosclerotic lesions. Based on preliminary studies, we hypothesize HDL removes msRNA from lesion macrophages through retro-endocytosis, a process that is inhibited by IsoLG modifications on HDL. Furthermore, we posit that msRNA activation of endo-lysosome TLR7/8 in lesion macrophages can be readily targeted with ntLNAs to reduce atherosclerosis. To test this hypothesis, we aim to I.) Determine the mechanism(s) and consequences of macrophage msRNA export to HDL, the impact of HDL-msRNA export on macrophage activation, and define the HDL-mediated reverse sRNA transport (RsRT) pathway in vivo, II.) Define the impact of dicarbonyl modifications and msRNA cargo on HDL dysfunction in CVD, and III.) Target macrophage msRNA receptors to inhibit atherosclerosis progression and promote regression. This project will open entirely new fields of study for lipoproteins, extracellular sRNAs, host/non-host interactions, and inflammation, which have applicability to many other diseases, but is particularly critical for CVD.

摘要：动脉粥样硬化是缺血性心血管疾病（CVD）的根本原因，是一种最佳的病理学表现。 其特征是动脉壁持续脂质沉积导致的不受控制的炎症反应。尽管 炎症在动脉粥样硬化进展中的重要性，但很少有治疗方法旨在针对 这一过程是由于普遍缺乏对生物活性脂质之外的致动脉粥样硬化刺激的了解。此前，我们 据报道，脂蛋白，即 HDL 和 LDL，可转运小非编码 RNA (sRNA)，最近， 我们发现脂蛋白富含来自细菌和真菌物种的 sRNA 微生物组和环境。有趣的是，这些外来微生物 sRNA (msRNA) 也非常丰富 动脉粥样硬化病变内的巨噬细胞并激活 sRNA 感应 Toll 样受体 (TLR)7/8 病变巨噬细胞。我们假设 HDL 接受来自病变巨噬细胞的 msRNA，从而抑制 TLR7/8 激活和下游促炎基因表达。支持这个模型的是巨噬细胞 发现很容易将 msRNA 输出到 HDL，并且 HDL 治疗被发现可以阻断 msRNA 诱导的 激活。在 CVD 中，HDL 获得与 HDL 功能障碍相关的反应性二羰基修饰。 在初步研究中，我们发现 HDL 上的反应性二羰基修饰，例如异黄兰素（IsoLG）， 损害 HDL-msRNA 输出。此外，我们发现 IsoLG 修饰的 HDL 增加了巨噬细胞的摄取 和保留并诱导促炎基因表达。初步研究还发现，治疗小鼠 使用反应性清除剂阻断 IsoLG 修饰的模型可减少动脉粥样硬化。因此，我们的目标是 使用非靶向锁定核酸 (ntLNA) 阻断 TLR7/8 的 msRNA 激活。令人惊讶的是，我们发现 ntLNA 治疗使 Apoe-/- 小鼠的动脉粥样硬化病变面积在 4 周内显着减少 30% 西方饮食。此外，单细胞 RNA 测序方法表明 ntLNA 疗法抑制 病变巨噬细胞中促炎基因的表达并减少促炎细胞的数量 动脉粥样硬化病变中的巨噬细胞。根据初步研究，我们假设 HDL 去除 msRNA 通过逆转录内吞作用从病变巨噬细胞中释放，这一过程受到 HDL 上 IsoLG 修饰的抑制。 此外，我们假设病变巨噬细胞中内溶酶体 TLR7/8 的 msRNA 激活可以很容易地被激活。 以 ntLNA 为靶点，减少动脉粥样硬化。为了检验这个假设，我们的目标是 I.) 确定 巨噬细胞 msRNA 输出到 HDL 的机制和后果，HDL-msRNA 输出对 HDL 的影响 巨噬细胞激活，并定义体内 HDL 介导的反向 sRNA 转运 (RsRT) 途径，II。）定义 二羰基修饰和 msRNA 货物对 CVD 中 HDL 功能障碍的影响，以及 III.) 目标 巨噬细胞 msRNA 受体抑制动脉粥样硬化进展并促进消退。该项目将 为脂蛋白、细胞外 sRNA、宿主/非宿主相互作用以及 炎症适用于许多其他疾病，但对心血管疾病尤其重要。