凝集素样氧化低密度脂蛋白受体1对动脉粥样硬化血管细胞作用的研究进展

<正>动脉粥样硬化性血管疾病是一种主要累及大中肌性动脉的慢性疾病,其主要组织学特征是富含脂质的粥样斑块,其中胆固醇的低密度脂蛋白(LDL)进入易发生动脉粥样硬化的动脉内膜中,同时伴随单核细胞黏附于管腔的内皮细胞上。单核细胞受炎性内皮细胞释放的促炎因子趋化,而进入内膜下并分化为巨噬细胞~([1])。巨噬细胞吞噬氧化低密度脂蛋白(ox-LDL)后不能利用脂质,最终转变成泡沫细胞。巨噬细胞活化后,可释放促炎细胞因子、增加活性氧产生、促进氧化应激进展~([2])。巨噬细胞可通过一些清道夫受体(SR),     

血清高密度脂蛋白亚类1对人单核源性巨噬细胞泡沫化的影响

目的 探讨血清高密度脂蛋白(HDL)亚类HDL1对人外周血单核源性巨噬细胞泡沫化的影响,认识其在HDL抗动脉粥样硬化(As)中所发挥的作用.方法 采用分段浓度聚丙烯酰胺凝胶电泳(sd-PAGE)法同步分离和定最制备血清HDL1.采用密度梯度离心法和塑料吸附法从人外周血中分离单核细胞,以50 nmol/L佛波酯(PMA)刺激48 h使之转化为巨噬细胞.细胞分为对照组与实验组,以HDL1干预后分别测定细胞内总胆固醇(TC)、游离胆固醇(FC)与蛋白质的含量,观察HDL1对细胞内TC/蛋白比值影响的量效关系和时效关系.结果 成功地建立了人单核源性泡沫细胞的模型,采用sd-PAGE法有效地从血清中分离出HDL1.经不同浓度(0、0.1、1.0和10.0 ms/ L)的HDL1作用后,细胞中TC/蛋白的比值随HDL1浓度的增加而旱剂茸依赖性降低(由36.9±1.1下降至6.2±0.4,P<0.01).细胞的泡沫化程度也随着HDL1浓度的升高而降低,且在浓度(10.0 mg/ L)一定的情况下,细胞中TC/ 蛋白比值随HDL1处理时间(6～24 h)的延长而呈时间依赖性降低(6 h:16.9±0.9,24 h:6.4±0.6,P<0.01).结论 HDL1通过降低细胞内TC的含量,一定程度上减轻了巨噬细胞的泡沫化程度,从而在HDL抗As的过程中发挥作用.     

植物凝集素样氧化型低密度脂蛋白受体-1与动脉粥样硬化

植物凝集素样氧化型低密度脂蛋白受体-1（lectin-likeoxidizedlow-densitylipoprotein receptor-1, LOX-1）是氧化型低密度脂蛋白（oxidized low-density lipoproteins, oxLDL）的主要受体之一。近年来的研究表明,LOX-1不仅可以结合、中和以及降解oxLDL,还能与一些非氧化脂蛋白和凋亡的血细胞结合,通过激活血小板、诱导炎症反应、促进血管平滑肌细胞增殖和迁移等多种途径参与动脉粥样硬化进程。文章从LOX-1的结构、功能及其与脂质代谢、动脉粥样硬化发病机制间的关系等方面,对相关研究进展进行了综述。     

氧化型低密度脂蛋白对外周血单核来源树突状细胞成熟及免疫功能的影响

目的 观测氧化型低密度脂蛋白(ox-LDL)对外周血单核来源的树突状细胞(DC)成熟及功能的影响,初步探讨其作用机理.方法 体外分离培养外周血单核来源的DC,按照处理方式不同分为4组,分别给予磷酸缓冲液(PBS)、低密度脂蛋白(LDL)、ox-LDL、肿瘤坏死因子a(TNF-a)刺激.随后进行流式细胞分析各组DC表面分子的表达情况.使用ELISA方法对培养上清中DC分泌的细胞凶子和趋化因子进行测定.使用FITC标记的葡聚糖检测DC吞噬抗原能力变化.使用Western blot方法对DC胞质内核冈子kB(NF-kB)、NF-kB抑制蛋白a(IkBa)的表达进行测定.结果 同空白对照组相比,经过ox-LDL处理后的外周血单核来源DC表达CIMO(22.3%比45.6%)、CD86 (25.9%比82.4%)均明显高,白介素12(31.43 pg/ml比126.73 pg/m1)、单核细胞趋化蛋白1(59.6ng/ml比116.3 ng/ml)分泌多,单核细胞炎性蛋白(MIP1)分泌无明显变化.同时处理后的DC抗原吞噬能力低(46.8%比10.7%),激活自体淋巴细胞增殖能力强(刺激指数4.5比5.7),免疫蛋白印迹实验表明,经ox-LDL处理后DC胞质IkBa的降解多,NF-kB表达高.结论 ox-LDL可以促进外周血单核来源的DC成熟,其机制与NF-kB抑制蛋白IkBa降解有关.     

激活视黄醇类X受体对氧化型低密度脂蛋白诱导小鼠巨噬细胞系RAW264.7向树突样细胞分化的影响

目的探讨激活核受体视黄醇类X受体（RXR）对氧化型低密度脂蛋白（ox—LDL）诱导巨噬细胞向树突状细胞分化的影响及其机制。方法小鼠巨噬细胞系RAW264．7经ox-LDL诱导48h后分化为树突样细胞,相差显微镜观察细胞形态,流式细胞仪检测细胞表面标志物,CM-H2DCFDA荧光探针测定细胞内活性氧浓度。结果ox—LDL诱导48h后,表达与树突状细胞免疫成熟和激活有关的细胞表面标志物CIMO、CD86、CD83、MHCClassⅡ和CD1d的RAW264．7细胞比例明显升高,同时给予天然型RXR特异性配体9-cisRA（10^-7mol／L）上述比例分别下降约47％、43％、48％、32％和17％,同时给予合成型RXR特异性配体SR11237（10^-6mol／L）上述比例分别下降约38％、38％、46％、36％和32％,并且均表现剂量依赖性。相差显微镜观察发现树突样细胞形态改变也得到部分抑制。ox-LDL引起细胞内活性氧浓度显著升高[平均荧光强度（MFI）38．24±4．20比4．46±0．39,P〈0．05],同时给予9．cisRA（10.mol／L）或SR11237（10^-6mol／L）MFI分别降低到12．60±1．52和17．89±1．91,较ox-LDL单独处理组差异有统计学意义（P〈0．05）。结论激活核受体RXR能够部分抑制ox-LDL诱导巨噬细胞向树突状细胞分化,其机制可能与减轻细胞氧化应激损伤有关。     

OxLDL对动脉粥样硬化血栓作用研究的进展

动脉粥样硬化(AS)是心血管疾病的主要病理生理基础,也是导致心血管疾病死亡的主要病因.氧化低密度脂蛋白(oxLDL)在AS斑块的发生发展和AS血栓的形成中起重要作用.OxLDL及其组分通过多种途径直接或间接促进促凝血活动及AS血栓的形成.本文就oxLDL及其组分对促进血栓形成的相关细胞和通路的影响作一综述.     

miR-155与NLRP3炎症体促进动脉粥样硬化的相关机制研究

微小RNA(miR)-155参与血管内皮细胞功能障碍、巨噬细胞炎症,是促进动脉粥样硬化发展的重要微小RNA。核苷酸结合寡聚化结构域样受体蛋白3(NLRP3)炎症体参与动脉粥样硬化斑块的产生,并与斑块不稳定性密切相关。但miR-155调节NLRP3炎症体在动脉粥样硬化中的机制仍不清楚。本文就miR-155与NLRP3炎症体在氧化低密度脂蛋白介导的动脉粥样硬化的相关机制作一综述。     

羧甲基赖氨酸对RAW264.7源性泡沫细胞迁移的影响

目的探讨糖基化终末产物关键活性成分羧甲基赖氨酸(CML)对泡沫细胞迁移能力的影响。方法 RAW264.7单核巨噬细胞制备成荷脂细胞后,分为对照组、氧化型低密度脂蛋白(oxLDL)组和干预组(CML+oxLDL孵育)。采用Boyden小室细胞迁移实验体外观察泡沫细胞跨膜迁移能力,胆固醇氧化酶法检测细胞内游离胆固醇(FC)、胆固醇酯(CE)及总胆固醇(TC)的含量;RT-PCR和Western blot法检测清道夫受体CD36表达的变化。结果与oxLDL组比较,干预组细胞内FC、CE和TC持续增多(P<0.05),CD36mRNA与蛋白表达显著上调,迁移泡沫细胞荧光强度下调59.79%(P<0.05);与对照组比较,干预组迁移泡沫细胞荧光强度下调73.46%(P<0.05)。结论 CML可能通过与oxLDL的协同,触发CD36级联信号,抑制泡沫细胞迁移。     

血脂康对低密度脂蛋白体外氧化修饰的影响

目的 探讨血脂康对人低密度脂蛋白体外氧化修饰的影响。方法 通过体外实验,观察血脂康对铜离子介导入低密度旧白氧化修饰后相对电泳迁移率的变化。结果 低深度脂蛋白在体外铅离子介导这长,其相对电泳迁移率增大,表明铜离子可诱导低密度脂蛋白发生氧化修饰。当加入血脂气康后,氧化低密度脂蛋白的相对电泳挺移率各时间点均较对照组低,两组相比,Ｐ〈０．０５,最大抑制率２４小时达峰值,为３３．５％。当加入不同深度血脂康作     

强化人群血脂分层管理和创新提出低密度脂蛋白胆固醇更低靶标

正现代临床脂质学理论认为,LDL-C不单是既往长期以来认为的动脉粥样硬化性心血管疾病(ASCVD)的独立危险因素,而且是迄今为止惟一被证实与ASCVD发生与发展相关的"致病性"因子。因此,加大LDL-C管控力度,进一步减少ASCVD的发生与发展具有重要科学与临床意义。2017年初,美国临床内分泌医师协会和内分泌学会(AACE/     

The role of natural IgM in myocardial ischemia-reperfusion injury

Myocardial ischemia-reperfusion injury represents a combination of factors, namely the intrinsic cellular response to ischemia and the extrinsic acute inflammatory response. Recent studies in mesenteric and skeletal muscle reperfusion models identified natural IgM as a major initiator of pathology through the activation of the complement system and inflammatory cells. To determine whether a similar mechanism is involved in myocardial tissues, mice bearing an altered natural IgM repertoire (Cr2-/-) were examined in a murine model of coronary artery ischemia. Notably, these mice were significantly protected based on the reduced infarct size, limited apoptosis of cardiomyocytes, and decreased neutrophil infiltration. Protection was IgM-dependent as reconstitution of these mice with wild-type IgM restored myocardial reperfusion injury. These results support a model in which natural IgM initiates the acute inflammatory response in the myocardium following ischemia and reperfusion.     

Antibodies of IgM subclass to phosphorylcholine and oxidized LDL are protective factors for atherosclerosis in patients with hypertension

OBJECTIVE: To determine the importance of antibodies against phosphorylcholine (PC) and oxidized low density lipoprotein (OxLDL) for development of atherosclerosis. METHODS AND RESULTS: Two hundred and twenty six individuals with established hypertension (diastolic pressure > 95mmHg) were from European Lacidipine Study on Atherosclerosis. Antibodies of IgG and IgM subclass were tested by ELISA against PC (aPC), cupper-oxidized (ox)- or malondialdehyde (MDA)-modified LDL. High-sensitivity C-reactive protein was measured by nephelometry. As a surrogate measure of atherosclerosis, we used the mean of the maximum intima-media thicknesses (IMT) in the far walls of common carotids and bifurcations was determined by ultrasonography at the time of enrolment, and 4 years following enrolment. aPC could be competed out by PC and OxLDL, while cardiolipin (CL) and beta2-glycoprotein I (beta2GPI) were less effective and phosphatidylserine (PS) not at all. Increases in IMT at follow-up were less common in subjects which at the time of enrolment had high IgM aPC (both 75th and 90th; odds ratios: 0.46; CI: 0.25-0.85; 0.36; CI: 0.15-0.87) and high IgM aOxLDL and aMDA-LDL (90th; odds ratios 0.27; p = 0.01; CI: 0.11-0.69 and 0.27; p = 0.01; CI: 0.11-0.69). CRP was unrelated to IMT-changes. The relationship between IgM aPC, aOxLDL and aMDA-LDL and changes in IMT was independent of age, treatment with atenolol or lacidipine, smoking and lipids. Women had higher levels of IgM antibodies tested (p < 0.05). CONCLUSIONS: High levels of IgM-antibodies against PC and OxLDL predict a favourable outcome in the development of carotid atherosclerosis in hypertensive subjects. Whether these antibodies could be used therapeutically deserves further study.     

Idiotypic determinants of natural IgM antibodies that resemble self Ia antigens.

A collection of immunoglobulin-secreting B-cell hybridomas was derived from normal neonatal BALB/c spleen and searched for reactivity against a panel of monoclonal anti-H-2 antibodies. We describe here one IgM antibody which was found to react with the monoclonal anti-Ia.7 antibody 14-4-4S. The characterization of this clone (BA.N 4:4.57) revealed its anti-trinitrophenyl specificity and demonstrated specific binding to five different monoclonal anti-Ia.7 antibodies but not to other anti-H-2 antibodies. The variable region specificity of these interactions was shown by the use of pepsin Fab fragments of the IgM antibody. Anti-Ia.7 antibodies were shown to specifically inhibit plaque formation by the hybridoma cells, and dinitrophenylglycine was shown to inhibit the reaction between the IgM antibody and anti-Ia.7 molecules. We interpret these results as to indicate that BA.N 4:4.57 expresses an idiotope or idiotopes which mimic Ia.7 determinants. This idiotypic family is naturally expressed in both newborn and adult BALB/c mice, as shown by the presence in normal serum of IgM molecules that specifically react with the F(ab')2 fragment of the 14-4-4S antibody. We speculate on the importance of idiotypic mimicry with major histocompatibility complex determinants, for both the selection of natural antibody repertoires and the evolution of antibody genes.     

Detectability of IgM antibodies against TBE virus after natural infection and after vaccination

IgM antibodies against tick-borne encephalitis (TBE) virus were investigated by means of a three-layer ELISA (antigen bound to the solid phase) and a four-layer ELISA (anti-mu-serum bound to the solid phase) after natural infection as well as after vaccination. In general, the four-layer ELISA detected IgM antibodies more often and for a longer period of time than the three-layer test. In some patients, IgM antibodies were detected for as long as eight months after the disease with the four-layer test but for only six months with the three-layer test. In addition, after the second TBE vaccination, IgM antibodies were found for as long as eight months in 24 sera which were taken within eight months after the second vaccination. Five were positive in the three-layer ELISA and 16 in the four-layer test. IgM antibodies were never detected in specimens taken later than ten months after the second and third vaccination. The results are of diagnostic importance in infections of the CNS which are not caused by TBE virus and which have been preceded by a possibly silent TBE virus infection or by a TBE vaccination.