代谢重编程:单核/巨噬细胞训练免疫参与动脉粥样硬化的新机制

动脉粥样硬化是血管的慢性炎症性疾病,单核/巨噬细胞的异常活化与动脉粥样硬化的发生发展密切相关。近期研究发现单核/巨噬细胞可以通过训练免疫发生代谢重编程,促进炎症反应,加快动脉粥样硬化的进展,并可以导致心血管意外事件的发生。文章综述了单核/巨噬细胞代谢重编程在训练免疫发生中的作用和机制,可能为动脉粥样硬化的防治提供新的治疗靶点和方法。     

细胞胆固醇流出通路研究进展

动脉粥样硬化的形成是动脉壁内泡沫细胞逐渐沉积的慢性炎症过程。循环中的氧化脂质特别是氧化型低密度脂蛋白胆固醇,以及一些体液因子、细胞因子均可引起单核巨噬细胞表面的清道夫受体表达增加,单核巨噬细胞吞噬大量含胆固醇的脂质,胆固醇流出减少,形成泡沫细胞,并在内皮下聚集,从而促进动脉粥样硬化的发生。     

CD36抗原在动脉粥样硬化发生机制中的作用

CD36抗原是一个多配体清道夫受体,广泛分布于多种不同的细胞表面,如血小板、单核/巨噬细胞、内皮细胞和平滑肌细胞表面.单核/巨噬细胞表面的CD36抗原通过黏附和内吞氧化低密度脂蛋白形成泡沫细胞,在动脉粥样硬化斑块形成中起到重要作用.现就CD36在动脉粥样硬化发病机制中的重要作用作以下综述.     

动脉粥样硬化与组织因子

组织因子在动脉粥样硬化过程中发挥重要作用,内皮细胞、单核/巨噬细胞、细胞的趋化和迁移均与之密切相关,动脉粥样硬化和再狭窄过程中的平滑肌细胞增殖也与之相关。     

MicroRNA在动脉粥样硬化中的研究进展

动脉粥样硬化的病理生理过程不仅包括内皮损伤、单核/巨噬细胞、平滑肌细胞,此外尚包含脂质代谢等其他病理生理过程。microRNA在动脉粥样硬化中的作用一直是近年来研究的热点,取得了许多成绩,microRNA通过对动脉粥样硬化相关靶基因转录后的调控,起到抑制或促进动脉粥样硬化的发展,为动脉粥样硬化的治疗提供了新的靶点,然而目前许多研究仅停留在实验阶段,其具体作用机制尚有待于进一步研究,相信在不久的将来,microRNA的研究一定能为动脉粥样硬化的诊断和治疗提供新的机会。     

A类清道夫受体参与动脉粥样硬化形成的机制

A类清道夫受体是单核巨噬细胞表面的一种跨膜糖蛋白的三聚体,调节巨噬细胞内脂质沉积,参与动脉粥样硬化斑块的形成。现综述且整理相关A类清道夫受体的最新进展,通过炎症调控、内质网应激、巨噬细胞由M1向M2型转化以及胰岛素抵抗等途径,阐明A类清道夫受体在动脉粥样硬化形成中的作用,同时简述了饮食及药物对A类清道夫受体水平的影响。     

不要低估血管平滑肌细胞在动脉粥样硬化斑块形成中的作用

血管内皮细胞、平滑肌细胞(SMC)和巨噬细胞共同参与动脉粥样硬化(As)斑块形成。近年研究表明,SMC来源的细胞占As斑块中细胞总数的70%以上。As斑块中的SMC通过自分泌细胞因子促进自身的增殖、迁移和炎症反应,通过旁分泌激活单核/巨噬细胞并将其募集到As损伤部位,同时通过其细胞膜表面表达的脂蛋白受体摄取脂质形成泡沫细胞。SMC在As斑块形成中扮演十分重要的角色,应进一步深化对SMC在As发生发展中的作用及作用机制的研究。     

PPAR-γ对单核/巨噬细胞酰基辅酶A:胆固醇酰基转移酶-1表达效应的研究

目的　研究配体罗格列酮活化的过氧化体增殖物激活型受体 γ(PPAR γ)对单核 /巨噬细胞转分化过程中酰基辅酶A :胆固醇酰基转移酶 1 (Acyl CoA :cholesterolacyltransferases,ACAT 1 )表达效应的影响。 方法　在RPMI1 640培养基中培养人单核细胞 (THP 1 ) ,加入佛波酯(PMA)培养 48h,细胞贴壁呈巨噬细胞样分化。运用免疫细胞化学、逆转录聚合酶链反应、蛋白质免疫印迹等方法 ,观察单核巨噬细胞转分化前后PPAR γ对ACAT 1mRNA和蛋白表达水平的影响。结果　单核巨噬细胞转分化前后ACAT 1表达增加 ,罗格列酮活化的PPAR γ可明显抑制A CAT 1的表达。结论　动脉粥样硬化事件的发生可能与ACAT 1表达增强有关。罗格列酮活化的PPAR γ可能通过抑制ACAT 1表达 ,巨噬细胞摄取脂质降低 ,从而减少泡沫细胞的形成 ,发挥其抗动脉粥样硬化的作用     

Src调控动脉粥样硬化斑块中巨噬细胞脂质累积的机制研究

目的:探究Src对动脉粥样硬化斑块中巨噬细胞脂质累积的调控机制。方法:取发生动脉粥样硬化的股动脉(病变组)与正常乳内动脉(对照组)组织,免疫组织化学法检测组织中磷酸化Src表达水平。采用Src干扰小RNA(siRNA)转染和Src蛋白激酶特异性抑制剂PP2处理巨噬细胞,通过油红O染色及比色法测定其胞内脂质含量,探究Src对巨噬细胞脂质累积的作用机制。通过构建C57BL/6小鼠动脉粥样硬化模型,进一步确定Src在动脉粥样硬化过程中的重要作用。结果:与正常对照相比较,动脉粥样硬化斑块中磷酸化Src表达量明显升高(P<0.05),且与CD68阳性细胞(巨噬细胞)共定位良好;降低Src表达水平和活性后,氧化低密度脂蛋白(oxLDL)诱导的巨噬细胞内脂质累积减少(P<0.05)。结论:Src可能通过介导巨噬细胞脂质累积调控动脉粥样硬化斑块的形成。     

巨噬细胞自噬:稳定动脉粥样硬化斑块的潜在治疗靶点

巨噬细胞能够摄取脂蛋白,积累脂质,形成泡沫细胞,并释放多种酶、炎症介质,在动脉粥样硬化的发生、进展中起重要作用。研究发现,诱导巨噬细胞自噬能够稳定动脉粥样硬化斑块。该文主要介绍巨噬细胞自噬在动脉粥样硬化中的作用,以及其作为治疗靶点稳定动脉粥样硬化斑块的研究成果。     

脂肪分化相关蛋白对泡沫细胞形成中脂质蓄积的影响

动脉粥样硬化是一种常见的心血管代谢性疾病,它的主要并发症心肌梗死与缺血性脑卒中已经成为世界首要的死因。泡沫细胞的形成在动脉粥样硬化的发生和发展中起到关键作用。这些细胞的产生与细胞内脂质蓄积密切相关。脂肪分化相关蛋白(PLIN2)能够促进细胞内脂质蓄积。本文主要阐述在泡沫细胞形成中,PLIN2对于脂质蓄积的影响,为动脉粥样硬化防治提供新的思路。     

Deficiency of adipose differentiation-related protein impairs foam cell formation and protects against atherosclerosis

Foam cells are a hallmark of atherosclerosis. However, it is unclear whether foam cell formation per se protects against atherosclerosis or fuels it. In this study, we investigated the role of adipose differentiation-related protein (ADFP), a major lipid droplet protein (LDP), in the regulation of foam cell formation and atherosclerosis. We show that ADFP expression facilitates foam cell formation induced by modified lipoproteins in mouse macrophages in vitro. We show further that Adfp gene inactivation in apolipoprotein E-deficient (ApoE(-/-)) mice reduces the number of lipid droplets in foam cells in atherosclerotic lesions and protects the mice against atherosclerosis. Moreover, transplantation of ADFP-null bone marrow-derived cells effectively attenuated atherosclerosis in ApoE(-/-) mice. Deficiency of ADFP did not cause a detectable compensatory increase in the other PAT domain proteins in macrophages in vitro or in vivo. Mechanistically, ADFP enables the macrophage to maintain its lipid content by hindering lipid efflux. We detected no significant difference in lesion composition or in multiple parameters of inflammation in macrophages or in their phagocytic activity between mice with and without ADFP. In conclusion, Adfp inactivation in ApoE(-/-) background protects against atherosclerosis and appears to be a relatively pure model of impaired foam cell formation.     

异鼠李素通过抑制泡沫细胞形成增加动脉粥样硬化斑块稳定性的机制研究

背景 泡沫细胞的形成是动脉粥样硬化重要的病理基础,其是由巨噬细胞吞噬大量胆固醇和三酰甘油后转化而来.因此,如何促进巨噬细胞的脂质代谢、抑制其转化为泡沫细胞是延缓动脉粥样硬化病情进展的关键.目的 分析异鼠李素通过抑制泡沫细胞形成增加动脉粥样硬化斑块稳定性的机制.方法 本实验时间为2020年8月至2021年10月.动物实验...     

CD36 and macrophages in atherosclerosis

CD36 is a multi-ligand scavenger receptor present on the surface of a number of cells such as platelets, monocytes/macrophages, endothelial and smooth muscle cells. Monocyte/macrophage CD36 has been shown to play a critical role in the development of atherosclerotic lesions by its capacity to bind and endocytose oxidized low density lipoproteins (OxLDL), and it is implicated in the formation of foam cells. However, the significance of CD36 in atherosclerosis has recently been called into question by different studies, and therefore its exact role still needs to be clarified. The aim of this article is to carefully review the importance of CD36 as an essential component in the pathogenesis of atherosclerosis.     

Specific interaction of oxidized low-density lipoprotein with macrophage-derived foam cells isolated from rabbit atherosclerotic lesions

Interaction of oxidized LDL (OxLDL) with macrophage-derived foam cells is one of the key events in the development and progression of atherosclerosis. To study this interaction, macrophage-derived foam cells were isolated from rabbit atherosclerotic lesions and the expression of scavenger receptors for OxLDL was examined. Atherosclerosis was induced in rabbits by denudation of the large arteries, followed by a hypercholesteremic diet. Macrophage-derived foam cells, characterized by immunostaining with an RAM-11 antibody (a macrophage marker), contained a high content of intracellular lipid. Maximal binding of radiolabeled OxLDL to isolated macrophage-derived foam cells (1652+/-235 ng 125I-OxLDL/mg of cell protein) was 20-fold higher compared with Bmax values of monocytes. Levels of association of OxLDL to macrophage-derived foam cells isolated from atherosclerotic lesions 12 weeks after denudation were >3-fold higher compared with the levels expressed by macrophage-derived foam cells isolated after 6 weeks. Association of 125I-OxLDL could be completely blocked by OxLDL, and partially by acetylated LDL and polyinosinic acid, indicating the presence of a specific binding site for OxLDL on macrophage-derived foam cells. The induction of scavenger receptors for OxLDL on macrophage-derived foam cells during the development of atherosclerosis, as described in this study, may facilitate the lipid accumulation in macrophage-derived foam cells, as observed in advanced atherosclerotic lesions.     

Adiponectin-AdipoR1/2-APPL1 signaling axis suppresses human foam cell formation: differential ability of AdipoR1 and AdipoR2 to regulate inflammatory cytokine responses

ObjectiveAdiponectin is an adipokine that exerts anti-inflammatory and anti-atherogenic effects during macrophage transformation into foam cells. To further understand the signaling pathways of adiponectin involved in macrophage foam cell transformation, we investigated the roles of two adiponectin receptors (AdipoR1 and AdipoR2) and their downstream adaptor protein, phosphotyrosine interaction, PH domain and leucine zipper containing 1 (APPL1) in mediating adiponectin action on foam cell transformation.Methods and ResultsTransfections were performed to overexpress or knockdown AdipoR1 or AdipoR2 genes in human THP-1 monocytes. Lentiviral-shRNAs were also used to knockdown APPL1 gene in these cells. Foam cell transformation was induced via exposure to oxidized low-density lipoprotein (oxLDL). Our results showed that both AdipoR1 and AdipoR2 were critical for transducing the adiponectin signal that suppresses lipid accumulation and inhibits transformation from macrophage to foam cell. However, AdipoR1 and AdipoR2 were found to have differential effects in diminishing proinflammatory responses. While AdipoR1 was required by adiponectin to suppress tumor necrosis factor alpha (TNFα) and monocyte chemotactic protein 1 (MCP-1) gene expression, AdipoR2 served as the dominant receptor for adiponectin suppression of scavenger receptor A type 1 (SR-AI) and upregulation of interleukin-1 receptor antagonist (IL-1Ra). Knockdown of APPL1 significantly abrogated the ability of adiponectin to inhibit lipid accumulation, SR-AI and nuclear factor-κB (NF-κB) gene expression, and Akt phosphorylation in macrophage foam cells.ConclusionsIn current studies, we have demonstrated that adiponectin's abilty to suppress macrophage lipid accumulation and foam cell formation is mediated through AdipoR1 and AdipoR2 and the APPL1 docking protein. However, AdipoR1 and AdipoR2 exhibited a differential ability to regulate inflammatory cytokines and SR-A1. These novel data support the idea that the adiponectin-AdipoR1/2-APPL1 axis may serve as a potential therapeutic target for preventing macrophage foam cell formation and atherosclerosis.     

动脉粥样硬化敏感小鼠C57BL/6J腹膜巨噬细胞源性泡沫细胞模型的建立

泡沫细胞的出现是动脉粥样硬化斑块中有特征性的病理形态改变。本实验选择对动脉粥样硬化形成较敏感的纯系小鼠C57BL/6J,取其腹膜巨噬细胞与10mg·L-1氧化低密度脂蛋白共同孵育96h,建立了典型的巨噬细胞源性泡沫细胞模型。实验结果显示,培养的泡沫样细胞与在无脂蛋白培养基中培养的C57BL/6J小鼠巨噬细胞和在氧化低密度脂蛋白中培养的昆明种小鼠巨噬细胞比较,脂质成分大量增多,出现脂质颗粒,细胞内总胆固醇增加,其中胆固醇酯含量大于游离胆固醇,符合泡沫细胞的定义。本实验从离休细胞培养方面探寻建立小鼠巨噬细胞源性泡沫细胞的可能性,为动脉粥样硬化的形成机理分析和防治研究提供了一种可靠的病理细胞模型。     

Hydrazine compounds inhibit glycation of low-density lipoproteins and prevent the in vitro formation of model foam cells from glycolaldehyde-modified low-density lipoproteins

Aims/hypothesis Previous studies have shown that glycation of LDL by methylglyoxal and glycolaldehyde, in the absence of significant oxidation, results in lipid accumulation in macrophage cells. Such ‘foam cells’ are a hallmark of atherosclerosis. In this study we examined whether LDL glycation by methylglyoxal or glycolaldehyde, and subsequent lipid loading of cells, can be inhibited by agents that scavenge reactive carbonyls. Such compounds may have therapeutic potential in diabetes-associated atherosclerosis. Materials and methods LDL was glycated with methylglyoxal or glycolaldehyde in the absence or presence of metformin, aminoguanidine, Girard’s reagents P and T, or hydralazine. LDL modification was characterised by changes in mobility (agarose gel electrophoresis), cross-linking (SDS-PAGE) and loss of amino acid residues (HPLC). Accumulation of cholesterol and cholesteryl esters in murine macrophages was assessed by HPLC. Results Inhibition of LDL glycation was detected with equimolar or greater concentrations of the scavengers over the reactive carbonyl. This inhibition was structure-dependent and accompanied by a modulation of cholesterol and cholesteryl ester accumulation. With aminoguanidine, Girard’s reagent P and hydralazine, cellular sterol levels returned to control levels despite incomplete inhibition of LDL modification. Conclusions/interpretation Inhibition of LDL glycation by interception of the reactive aldehydes that induce LDL modification prevents lipid loading and model foam cell formation in murine macrophage cells. Carbonyl-scavenging reagents, such as hydrazines, may therefore help inhibit LDL glycation in vivo and prevent diabetes-induced atherosclerosis.     

Absence of CC chemokine receptor-2 reduces atherosclerosis in apolipoprotein E-deficient mice

The accumulation of circulating monocytes in the arterial wall is an early event in atherosclerotic plaque formation. Monocyte chemoattractant protein-1 (MCP-1) has been implicated as the primary source of monocyte chemoattractant functioning in these early stages of atherogenesis. To determine whether the receptor for MCP-1, CC chemokine receptor CCR2, plays a role in atherogenesis, CCR2-deficient animals were crossed with mice lacking apo E, a well characterized model of atherosclerosis. While lipid levels were unchanged, the double knockout mice exhibited a 3-fold reduction in mean aortic lesion area compared to apo E-deficient control mice. Furthermore, the lesions in the double mutants were less advanced, consisting primarily of foam cell deposits and fatty streaks located on or directly adjacent to the aortic valve attachment sites. These studies directly demonstrate that the MCP-1 receptor, CCR2, plays an important role in atherogenesis.     

MRTF-A在动脉粥样硬化病变中的研究进展

动脉粥样硬化是心血管事件发生的重要因素。相关流行病学调查显示,近几年中国动脉粥样硬化性心血管疾病负担快速而显著增加,给国家公共卫生问题带来重大挑战。心肌素相关转录因子A(MRTF-A)在动脉粥样硬化发展进程中发挥着重要作用,包括参与炎症反应、促进粥样硬化进程中脂质积聚及促进血管平滑肌细胞表型转化等,探索MRTF-A在动脉粥样硬化病变中的研究进展对于寻找新的治疗靶点具有重要意义。文章就MRTF-A在动脉粥样硬化病变过程中的作用进行综述,可为冠状动脉粥样硬化的靶向治疗提供参考。