Ghrelin对THP-1细胞泡沫化过程中酰基辅酶A：胆固醇酰基转移酶1表达的影响

目的： 研究单核/巨噬细胞分化成为泡沫细胞过程中ghrelin对人酰基辅酶A:胆固醇酰基转移酶1(ACAT-1)表达以及细胞内胆固醇酯的影响。方法: 体外培养人源单核细胞系（THP-1）,由佛波酯（PMA）作用使其分化为巨噬细胞,后者可在氧化低密度脂蛋白（ox-LDL）存在条件下进一步转变为泡沫细胞。巨噬细胞加入不同浓度的ghrelin预孵2 h后再加入ox-LDL,油红O染色法观察细胞内脂滴含量,运用RT-PCR法检测ACAT-1 mRNA水平,Western blotting法检测ACAT-1蛋白表达,采用酶法,通过荧光分光光度计检测细胞内胆固醇酯含量。结果: Ghrelin可明显减少THP-1源性泡沫细胞内脂滴的形成,显著降低细胞内胆固醇酯含量,并能显著降低单核/巨噬细胞泡沫化过程中ACAT-1 mRNA 水平和蛋白表达,且此干预作用呈浓度依赖性。结论: Ghrelin可能通过ACAT-1转录翻译水平的下调延缓动脉粥样硬化的发生。     

Effects of ADMA on the expression of acyl-coenzyme A:Acylcholesterol transferase-l ( ACAT-I ) in cell differentiation from mononuclear/macrophage cells to foam cells

目的 观察不对称二甲基精氨酸(ADMA)对单核/巨噬细胞分化为泡沫细胞过程中酰基辅酶A胆固醇酰基转移酶-1(ACAT-1)表达的影响.方法 1)THP-1单核细胞与160 nmol/L佛波酯(PMA)孵育48 h后,再与80 mg/L氧化型低密度脂蛋白(ox-LDL)孵育24h,用油红O染色在光镜下鉴定细胞形态及变化.2)将THP-1单核细胞、巨噬细胞、泡沫细胞分别用20 μmol/L ADMA干预24h,酶法测泡沫细胞内胆固醇酯的含量,RT-PCR方法检测ACAT-1mRNA表达,Western blot方法检测其蛋白表达.结果 1)ADMA可显著增加泡沫细胞内胆固醇酯的含量.2)与THP-1单核细胞相比,巨噬细胞(P＜0.05)、泡沫细胞(P＜0.01)中ACAT-I mRNA及蛋白表达增加;而与巨噬细胞相比,泡沫细胞中ACAT-I mRNA及蛋白表达增加但无显著性差异.3)与各自的对照组相比,经ADMA作用后3种细胞中ACAT-I mRNA及蛋白表达水平均增加(P＜0.01).结论 ADMA增加泡沫细胞内胆固醇酯的含量可能是通过上调ACAT-1的mRNA及蛋白表达来实现的.     

动脉粥样硬化中炎症免疫反应的研究进展

动脉粥样硬化是一种慢性炎症免疫性疾病。炎症反应被认为是动脉粥样硬化斑块形成,发展时转变为不稳定斑块、甚至斑块破裂的主要驱动力。动脉粥样硬化斑块中出现的大量免疫细胞浸润,如单核/巨噬细胞、DC、T细胞及B细胞等都对动脉粥样硬化的发展进程具有重要影响。本文综述免疫细胞在动脉粥样硬化的发生发展过程中的作用。     

不对称二甲基精氨酸对单核/巨噬细胞分化为泡沫细胞过程中酰基辅酶A胆固醇酰基转移酶-1表达的影响

 [摘要] 目的 观察不对称二甲基精氨酸（ADMA）对单核/巨噬细胞分化为泡沫细胞过程中酰基辅酶A胆固醇酰基转移酶-1（ACAT-1）表达的影响。 方法 （1）THP-1单核细胞与160nmol/L佛波酯（PMA）孵育48h后,再与80mg/L氧化型低密度脂蛋白（ox-LDL）孵育24h,用油红O染色在光镜下鉴定细胞形态及变化。（2） 将THP-1单核细胞、巨噬细胞、泡沫细胞分别用20μmol/L ADMA干预24h,酶法测泡沫细胞内胆固醇酯的含量,RT-PCR方法检测ACAT-1mRNA表达,Western blot方法检测其蛋白表达。 结果 （1）ADMA可显著增加泡沫细胞内胆固醇酯的含量。（2）与THP-1单核细胞相比,巨噬细胞（p<0.05）、泡沫细胞（p<0.01）中ACAT-1mRNA及蛋白表达增加;而与巨噬细胞相比,泡沫细胞中ACAT-1mRNA及蛋白表达增加但无显著性差异。（3）与各自的对照组相比,经ADMA作用后3种细胞中ACAT-1mRNA及蛋白表达水平均增加（p<0.01）。结论 ADMA增加泡沫细胞内胆固醇酯的含量可能是通过上调ACAT-1的mRNA及蛋白表达来实现的。     

细胞表面蛋白与动脉粥样硬化研究进展

动脉粥样硬化的分子机制已经被广泛研究,其中细胞黏附分子、作用于细胞表面的细胞因子和细胞表面受体等细胞表而蛋白介导了单核巨噬细胞与内皮细胞之间的黏附、白细胞浸润、氧化低密度脂蛋白(oxidized low density lipoprotein,OX-LDL)的摄取以及泡沫细胞的形成和炎症反应等动脉粥样硬化进程.近年来,越来越多的这些分子及它们存动脉粥样硬化发病过程的作用被发现阐明,为我们更好的了解和治疗动脉粥样硬化提供了良好的理论基础.     

细胞表面蛋白与动脉粥样硬化研究进展

动脉粥样硬化的分子机制已经被广泛研究,其中细胞黏附分子、作用于细胞表面的细胞因子和细胞表面受体等细胞表而蛋白介导了单核巨噬细胞与内皮细胞之间的黏附、白细胞浸润、氧化低密度脂蛋白(oxidized low density lipoprotein,OX-LDL)的摄取以及泡沫细胞的形成和炎症反应等动脉粥样硬化进程.近年来,越来越多的这些分子及它们存动脉粥样硬化发病过程的作用被发现阐明,为我们更好的了解和治疗动脉粥样硬化提供了良好的理论基础.     

细胞表面蛋白与动脉粥样硬化研究进展

动脉粥样硬化的分子机制已经被广泛研究,其中细胞黏附分子、作用于细胞表面的细胞因子和细胞表面受体等细胞表而蛋白介导了单核巨噬细胞与内皮细胞之间的黏附、白细胞浸润、氧化低密度脂蛋白(oxidized low density lipoprotein,OX-LDL)的摄取以及泡沫细胞的形成和炎症反应等动脉粥样硬化进程.近年来,越来越多的这些分子及它们存动脉粥样硬化发病过程的作用被发现阐明,为我们更好的了解和治疗动脉粥样硬化提供了良好的理论基础.     

MIF在斑块形成与不稳定性中的作用及其信号转导通路研究

近年来的研究逐渐凸现动脉粥样硬化的现代概念 :(1)动脉粥样硬化病变不是仅呈斑片状 ,而是呈现弥散性 ,只不过某些部位斑块较重而已 ;(2 )这些斑块的特点是含有大量巨噬细胞。吞噬脂质后细胞内外胆固醇聚积在一起 ,上面覆盖着一层薄薄的内皮 -纤维组织的“帽” ,即使它们并不造成高度的狭窄 ,但它可以破裂、出血、形成血栓、血管痉挛而造成猝死 ;(3)动脉粥样硬化的脂质沉积过程由炎症反应介导 ,此炎症反应的特征是 ,病变部位出现单核巨噬细胞、活化T细胞和纤维化。多项研究表明巨噬细胞复制见于动脉粥样硬化进展的各个阶段 ,巨噬细胞复制可…     

肺炎衣原体通过下调ABCA1和ABCG1诱导THP-1源性泡沫细胞形成

目的:观察ATP结合盒转运体A1(ABCA1)和ABCG1在肺炎衣原体(C.pn)诱导THP-1源性泡沫细胞形成中的作用,以初步探讨C.pn诱导泡沫细胞形成的分子机制.方法:C.pn在Hep-2细胞内增殖,将不同浓度的C.pn(1×105 ～1×106 IFU)分别感染THP-1单核细胞源性巨噬细胞0～72小时,运用油红O染色观察细胞浆内脂滴的变化,用酶荧光学法检测细胞内胆固醇酯含量的变化,分别运用RT-PCR和Western blot检测ABCA1、ABCG1 mRNA和蛋白表达.结果:高浓度的C.pn(5×105和1×106 IFU)感染THP-1单核细胞源性巨噬细胞48小时后,细胞浆内的脂滴明显增多,胆固醇酯与总胆固醇的比值明显增加(＞50%).C.pn感染呈浓度和时间依赖性地下调ABCA1、ABCG1 mRNA和蛋白表达(P＜0.05).结论:ABCA1和ABCG1表达下调是C.pn诱导THP-1源性泡沫细胞形成的机制之一,这可能为C.pn感染致动脉粥样硬化发病机制的研究提供一个新的理论依据.     

单核/巨噬细胞源性细胞因子与动脉粥样硬化

白细胞介素(IL)1,6,8和肿瘤坏死因子(TNF-α)是主要产生于单核/巨噬细胞的参与机体免疫的细胞因子。它们具有不同的生物学特性,并以特定的方式在动脉粥样硬化的发生、发展过程中起作用。     

A Chlamydia pneumoniae Component That Induces Macrophage Foam Cell Formation Is Chlamydial Lipopolysaccharide

Chlamydia pneumoniae infection is associated with atherosclerotic heart and vessel disease, but a causal relationship between this pathogen and the disease process has not been established. Recently, it was reported that C. pneumoniae induces human macrophage foam cell formation, a key event in early atheroma development, suggesting a role for the organism in atherogenesis. This study further examines C. pneumoniae-induced foam cell formation in the murine macrophage cell line RAW-264.7. Infected RAW cells accumulated cholesteryl esters when cultured in the presence of low-density lipoprotein in a manner similar to that described for human macrophages. Exposure of C. pneumoniae elementary bodies to periodate, but not elevated temperatures, inhibited cholesteryl ester accumulation, suggesting a role for chlamydial lipopolysaccharide (cLPS) in macrophage foam cell formation. Purified cLPS was found to be sufficient to induce cholesteryl ester accumulation and foam cell formation. Furthermore, the LPS antagonist lipid X inhibited C. pneumoniae and cLPS-induced lipid uptake. These data indicate that cLPS is a C. pneumoniae component that induces macrophage foam cell formation and suggest that infected macrophages chronically exposed to cLPS may accumulate excess cholesterol to contribute to atheroma development.     

Functions of cholesterol ester transfer protein and relationship to coronary artery disease risk

The protective role of HDL in atherosclerotic cardiovascular disease reflects in part its ability to promote cholesterol efflux via ATP binding cassette transporters ABCA1 and ABCG1 in macrophage foam cells. This initiates a process of reverse cholesterol transport from the arterial wall to the liver. Inhibition of cholesteryl ester transfer protein (CETP) raises HDL and probably stimulates cholesterol efflux and anti-inflammatory effects in macrophage foam cells but does not increase the overall process of reverse cholesterol transport. Single nucleotide polymorphisms in the CETP gene are associated with lower CETP, higher HDL and probably with reduced CAD. Initial clinical trials with the CETP inhibitor torcetrapib were associated with an adverse outcome that mainly seemed to arise from offtarget toxicity.     

Chlamydia pneumoniae--induced macrophage foam cell formation is mediated by Toll-like receptor 2

Chlamydia pneumoniae induces macrophage foam cell formation, a hallmark of early atherosclerosis, in the presence of low-density lipoprotein (LDL). This study examined the role that Toll-like receptor 2 (TLR2) and TLR4 may play in pathogen-induced foam cell formation. Murine macrophage RAW 264.7 cells either infected with C. pneumoniae or treated with the TLR4 ligand E. coli lipopolysaccharide (LPS) or the TLR2 ligand Pam(3)-Cys-Ala-Gly-OH (Pam) became Oil Red O-stained foam cells and showed increased cholesteryl ester (CE) content when cocultured with LDL. In macrophages from TLR2(-/-) mice, foam cells were induced by Escherichia coli LPS but not by C. pneumoniae or Pam. Conversely, C. pneumoniae or Pam, but not E. coli LPS, induced foam cells in the TLR4-deficient GG2EE macrophage cell line, suggesting that C. pneumoniae elicits foam cell formation predominantly via TLR2. Enhancing cholesterol efflux using the liver X receptor (LXR) agonist GW3965 significantly decreased the CE content of cells exposed to each of the three TLR ligands (C. pneumoniae, Pam, and E. coli LPS). Overall, our results suggest that activation of the LXR signaling pathway may affect potentially atherogenic processes modulated by the TLR ligands.     

甲基莲心碱对RAW264.7巨噬细胞泡沫化的影响

目的探讨甲基莲心碱(Nef)对巨噬泡沫细胞形成的作用及机制。方法采用体外培养小鼠巨噬细胞系RAW264.7细胞,ox-LDL诱导建立泡沫细胞模型,用Nef进行干预。油红O染色观察细胞内脂质堆积情况,酶比色法定量细胞内总胆固醇和胆固醇酯的变化,免疫荧光和流式细胞术分析CD36受体蛋白表达,RT-PCR检测CD36受体mRNA表达。结果与ox-LDL诱导组相比,Nef保护组巨噬细胞的油红O染色阳性细胞数和细胞内脂质含量均显著减少;同时CD36受体蛋白和mRNA表达明显降低。结论Nef可抑制ox—LDL诱导的RAW264.7巨噬细胞泡沫化,该作用可能与Nef下调巨噬细胞CD36受体表达,从而减弱巨噬细胞对ox—LDL的摄取有关。     

CD4~+CD25~+调节性T细胞对巨噬细胞泡沫化的影响

目的 研究CD4~+ CD25~+调节性T细胞(Tr)对巨噬细胞泡沫化过程的影响及机制.方法 磁性细胞分离器(MACS)分离CD4~+ CD25~+ T细胞及CD4~+ CD25~- T细胞,在氧化型低密度脂蛋白(oxLDL)作用下,将巨噬细胞分别与CD4~+ CD25~+ T细胞、CD4~+ CD25~- T细胞共培养48 h.采用油红O染色和细胞内脂质测定的方法观察CD4~+ CD25~+ T细胞对巨噬细胞泡沫化的影响;采用RT-PCR、real-time PCR、Western blot的方法测定泡沫细胞清道夫受体(CD36和SRA)的表达.结果 与对照组比较,CD4~+ CD25~+ T细胞可显著抑制巨噬细胞脂质聚集及清道夫受体的表达.结论 CD4~+CD25~+ T细胞可显著抑制巨噬细胞泡沫化,其作用机制可能为下调清道夫受体的表达.     

Porphyromonas gingivalis induces murine macrophage foam cell formation

Atherosclerosis is a complex pathologic process initialed by the formation of cholesterol-rich plaque. Macrophages play a central role in the development of atherosclerosis, specifically in the initial accumulation of cholesterol in the arterial wall. It has been suggested that infection and chronic inflammatory conditions such as periodontitis may influence the atherosclerosis process. Porphyromonas gingivalis, one of the major pathogens involved in periodontitis, has been detected in human atheromas, suggesting that P. gingivalis infection may be associated with atherosclerosis. However, a causal relationship between this pathogen and the disease process has not yet been established. The purpose of the present investigation was to determine whether P. gingivalis could induce macrophages to form foam cells using the murine macrophage cell line (J774) as a model system. For inocula smaller than one bacterium per ten cells, P. gingivalis 381, as well as its lipopolysaccharide (LPS), induced foam cell formation of macrophages when cultured in the presence of human low-density lipoprotein (LDL). Infection of macrophages with increasing doses of P. gingivalis resulted in higher levels of foam cell formation. More than 70% of the cultured macrophages form cholesterol ester droplet-rich cells in the presence of 100 mug/ml of LDL when the inocula was more than 10 bacteria per cell. Low concentrations of P. gingivalis outer membrane vesicles also induced foam cell formation in the presence of LDL. In addition, it was demonstrated that P. gingivalis LPS alone was able to induce macrophage foam cell formation. P. gingivalis and its vesicles not only promoted LDL binding to macrophages but also induced macrophages to modify native LDL, which plays an important role in foam cell formation and the pathogenesis of atherosclerosis. Therefore, P. gingivalis cells or its vesicles released from periodontal lesions into the circulation may deliver virulence factor(s) such as LPS to the arterial wall to initiate or promote foam cell formation in macrophages and contribute to atheroma development.     

氧化低密度脂蛋白及溶血卵磷脂对巨噬泡沫细胞胆固醇外流的影响

目的:观察氧化低密度脂蛋白(OxLDL)及其成分溶血卵磷脂(LPC)对小鼠腹腔巨噬泡沫细胞胆固醇外流的影响及其机制的初步探讨。方法:(1)以载脂蛋白AI(apoAI)分别诱导OxLDL和乙酰化低密度脂蛋白(AcLDL)负载小鼠腹腔巨噬细胞所形成的巨噬泡沫细胞, 观察其胆固醇外流情况。(2)分离正常及apoE基因缺陷(E⁰)小鼠腹腔巨噬细胞, 以AcLDL负载形成巨噬泡沫细胞, 分别以LPC及apoAI作为诱导物, 观察其胆固醇外流情况。结果:(1)apoAI能引起AcLDL组巨噬泡沫细胞胆固醇大量外流, 而OxLDL组外流明显受阻。(2)LPC能引起正常组小鼠腹腔巨噬泡沫细胞胆固醇外流, 且呈剂量效应关系, 但E⁰组未见明显外流;apoAI能引起两组的胆固醇外流, 且外流量显著高于LPC。结论:(1)OxLDL能造成胆固醇外流途径受阻。(2)LPC能促进巨噬泡沫细胞胆固醇外流, 可能主要通过apoE途径来进行。     

巨噬细胞及巨噬细胞自噬在动脉粥样硬化中的作用研究

动脉粥样硬化(AS)是一种常见的慢性血管炎性病变,可导致多种心脑疾病.目前认为,脂代谢失衡与巨噬细胞在吞噬脂质过程中引发的异常免疫反应是动脉粥样硬化发病的重要原因.因而研究巨噬细胞及自噬在AS发生和发展中的作用及其相关的治疗靶点具有重要意义.     

The macrophage in atherosclerosis: modulation of cell function by sterols.

Lipid-laden macrophage foam cells are an early and persistent component of atherosclerotic lesions. As such they are likely to play a key role in disease progression, both as scavengers of lipid and as inflammatory mediators. The sterol content of macrophage foam cells is largely native cholesterol together with a small but significant proportion of oxidized cholesterol (oxysterols). Few in vitro investigations of the influence of sterol accumulation on macrophage function have used cells that contain physiologically or even pathologically representative amounts of cholesterol or, more particularly, oxysterols. However, recent studies, using macrophages with a sterol content much closer to that of authentic foam cells, show that the presence of oxysterols causes an impairment in macrophage cholesterol export, suggesting a key role for oxysterols in the maintenance of the foam cell phenotype. The implications of physiologically relevant levels of oxysterols on a wider range of macrophage function remain to be investigated.