MMPs在动脉粥样硬化斑块局部的调控机制

基质金属蛋白酶（MMPs）在动脉粥样硬化的发生、发展过程中扮演重要角色,不仅涉及斑块局部炎性细胞浸润、血管平滑肌细胞迁移,还可通过降解细胞外基质促使斑块破裂。动脉粥样硬化斑块局部MMPs的调控机制十分复杂,包括转录、翻译、酶原激活及激活后调节等多个方面。     

基质金属蛋白酶与动脉粥样硬化斑块

基质金属蛋白酶(MMP)可降解细胞外基质,参与动脉粥样硬化形成和斑块破裂,与斑块稳定性有关.组织金属蛋白酶抑制剂(TIMP)是天然的MMP特异性抑制剂.MMP与TIMP的平衡失调与动脉粥样硬化的形成和发展密切相关.因此,通过调节MMP与TIMP之间的平衡延缓动脉粥样硬化的进展和防治斑块破裂,有可能成为防治心脑血管病的新途径.     

基质金属蛋白酶与动脉粥样硬化及斑块破裂的关系

基质金属蛋白酶是一组能够降解血管细胞外基质成分的酶类。在动脉粥样硬化斑块的特定区域过度表达，可引起斑块基质的降解，从而导致斑块破裂，引发急性冠状动脉综合征。本文就基质金属蛋白酶在动脉粥样硬化及斑块破裂中的作用作一综述。     

糖尿病患者动脉粥样硬化斑块内基质金属蛋白酶2和9与斑块稳定的关系

目的　比较糖尿病患者与非糖尿病组患者动脉粥样硬化斑块内基质金属蛋白酶 2和基质金属蛋白酶 9表达的差异 ,初步探索基质金属蛋白酶 2和基质金属蛋白酶 9与糖尿病动脉粥样硬化斑块稳定的关系。方法　从2 3例糖尿病足截肢和 17例尸检下肢动脉标本中选取晚期动脉粥样硬化病变的组织块共 12 6块 ,分为糖尿病组 (74块 )和非糖尿病组 (5 2块 ) ,从中随机选取各 4 0个组织块 ,运用免疫组织化学染色法检测基质金属蛋白酶 2和 9在两组粥样硬化斑块中的表达。结果　糖尿病组抗基质金属蛋白酶 2、抗基质金属蛋白酶 9免疫沉积物主要集中在斑块核心周围 ,特别是在斑块的肩部和纤维帽。糖尿病组动脉斑块内抗基质金属蛋白酶 2免疫沉积物表达显著高于非糖尿病组 (免疫沉淀物积分光密度值分别为 6 90 14± 14 4 5 9和 5 70 0 4± 16 171,阳性面积百分比分别为 13.0 %± 2 .7%和 11.1%± 3.3% ) ;糖尿病组斑块内基质金属蛋白酶 9表达也显著高于非糖尿病组 (免疫沉淀物积分光密度值分别为 10 2 4 85± 2 0 4 31和 75 2 80± 1310 6 ,阳性面积百分比分别为 18.4 %± 3.6 %和 13.7%± 2 .3% )。结论　基质金属蛋白酶 2和 9在糖尿病组动脉粥样硬化斑块中的表达显著高于非糖尿病组。基质金属蛋白酶 2和 9在糖尿病动脉中表达增     

大黄素稳定小鼠动脉粥样硬化斑块的机制

目的 探讨大黄素对小鼠动脉粥样硬化(AS)斑块内基质金属蛋白酶-2(MMP-2)、基质金属蛋白酶-9(MMP-9)及金属蛋白酶组织抑制剂-1(TIMP-1)的影响,及其稳定AS斑块的机制.方法 30只7周龄ApoE-/-小鼠,适应性喂养1 w后,随机分为空白对照组、模型组和大黄素组,每组10只.空白对照组给予普通饮食,模型组给予高脂饮食,大黄素组在高脂饮食基础上给予大黄素60 mg·kg-1·d-1灌胃,空白对照组和模型组给予等量生理盐水灌胃.实验20 w末处死全部小鼠,留取主动脉根部标本,用免疫组织化学方法检测AS斑块内MMP-2、MMP-9及TIMP-1表达情况.结果 大黄素组MMP-2、MMP-9的表达较模型组显著减少(P<0.01、P<0.05),TIMP-1表达显著增高(P<0.01).结论 大黄素可通过减少斑块处MMP-2、MMP-9的表达,增高TIMP-1表达,起到稳定AS斑块的作用.     

ECM、MMPs与易损斑块及斑块破裂的关系

细胞外基质(ECM)是血管平滑肌细胞分泌和合成的,是正常血管壁的主要成分,基质金属蛋白酶(MMPs)是降解细胞外基质成分的主要酶类,研究表明纤维帽中平滑肌细胞合成ECM减少和蛋白溶解酶特别是MMPs降解ECM的增加,是斑块破裂的内在主要原因.本文就ECM、MMPs与斑块破裂的关系做一简单综述.     

基质金属蛋白酶-9与动脉粥样硬化及斑块稳定性

冠心病是严重危害人类健康的常见病和多发病,其病理基础是动脉粥样硬化(AS).AS不稳定斑块的破裂是急性冠状动脉综合征(ACS)包括不稳定型心绞痛、急性心肌梗死、心源性猝死的主要原因.基质金属蛋白酶(MMPs) 是一种Zn2+和Ca2+依赖性的酶家族,能特异性地与细胞外基质(ECM)成分相结合并降解,从而削弱AS斑块纤维帽的结构,促进斑块破裂和血栓形成.     

前列腺素E1对兔动脉粥样硬化易损斑块的影响

目的研究前列腺素E1对兔动脉粥样硬化易损斑块的影响及机制。方法 22只新西兰大白兔高脂饲料(1%胆固醇)喂养2周后,进行腹主动脉球囊损伤术,术后继续高脂喂养,7周后,随机分为模型组、前列腺素E1组和辛伐他汀组,同时改为普通饲料继续喂养4周,13周末,所有兔给予中国斑点蝰蛇毒和组胺进行药物诱发。观察药物干预后血脂、斑块形态、斑块组分及炎症因子的变化。结果前列腺素E1对血脂没有影响;与模型组比较,前列腺素E1组能显著增加斑块的纤维帽厚度(101.72±34.89μm比79.86±16.98μm,P<0.01),减小斑块易损指数(0.94±0.27比3.83±1.45,P<0.01);并且能够显著抑制斑块中巨噬细胞的累积(P<0.01)及其分泌的炎症因子基质金属蛋白酶1和基质金属蛋白酶9的表达(P<0.01),前列腺素E1组与辛伐他汀组比较差异无显著性。结论前列腺素E1能够稳定兔动脉粥样硬化易损斑块,该作用与脂质代谢无关,但与抑制斑块中巨噬细胞的累积及其分泌炎症因子密切相关。     

血管紧张素Ⅱ1型受体自身抗体与动脉粥样硬化斑块局部炎症的关系

目的观察血管紧张素Ⅱ1型受体自身抗体(AT1-AA)与动脉粥样硬化动物模型粥样斑块局部炎症之间的关系。方法收集高血压合并急性冠状动脉综合征患者AT1-AA阳性和阴性的血清并纯化。建立30只球囊拉伤所致高脂血症兔动脉粥样硬化模型,随机分成6组:(1)对照组;(2)低浓度AT1-AA[20μg/(kg·d)]注射组(简称LA组);(3)高浓度AT1-AA[40μg/(kg·d)]注射组(简称HA组);(4)氯沙坦[20 mg/(kg·d)]灌胃+高浓度AT1-AA注射组(简称L+HA组);(5)辛伐他汀[4 mg/(kg·d)]灌胃+高浓度AT1-AA注射组(简称S+HA组);(6)7aa[1.5 mg/(kg·d)]灌胃+高浓度AT1-AA注射组(简称7aa+HA组),予以不同的处理。取兔腹主动脉进行HE染色,比较各组斑块所占管腔面积;同时用Western blot检测斑块局部MMP-2的表达。结果各组总胆固醇及低密度脂蛋白胆固醇水平在第4周后明显升高。除对照组外,其他各组在第8、10周血清AT1-AA水平均明显高于实验开始时。LA组、HA组斑块占管腔面积百分值分别为46.99%±13.06%、66.11%±19.67%,明显高于对照组(27.71%±7.46%)、L+HA组(34.27%±12.38%)、S+HA组(24.03%±8.56%)及7aa+HA组(28.54%±12.50%)(均P0.05)。LA组、HA组MMP-2的表达均明显高于其他各组(均P0.05)。结论 AT1-AA可明显促进高脂喂养兔受损动脉内膜处斑块形成,增强斑块局部炎症反应的发生及细胞增殖。     

间歇性低温刺激减少载脂蛋白E基因敲除小鼠动脉粥样硬化斑块内胶原含量的研究

目的：研究间歇性低温刺激对载脂蛋白E（ApoE-/-）基因敲除小鼠动脉粥样硬化斑块内胶原含量的影响。
　　方法：20只8周龄的雄性ApoE-/-小鼠被随机分为对照组和实验组,实验组小鼠每天8：00至12：00置于（4±1）° C环境中,其余时间和对照组小鼠一样处于（24±2）° C环境。饲养12周后,Masson染色了解小鼠主动脉根部动脉粥样硬化斑块内胶原情况,蛋白免疫印迹法（Western Blot）检测小鼠主动脉基质金属蛋白酶（MMPs）2、9及基质金属蛋白酶抑制剂1的表达情况。
　　结果：Masson染色见实验组小鼠主动脉根部斑块内胶原含量低于对照组,Western blot实验组小鼠主动脉MMP2、MMP9表达高于对照组,TIMP1表达低于对照组。
　　结论：间歇性低温刺激可能通过破坏MMPs/TIMPs之间的平衡,引起动脉粥样硬化斑块内胶原含量减少,造成易损斑块的形成,导致急性冠状动脉综合征的发生。     

通瘀煎对ApoE基因敲除小鼠动脉粥样硬化斑块形成的影响及机制

目的探讨通瘀煎对ApoE基因敲除小鼠动脉粥样硬化斑块形成的影响及其作用机制。方法50只ApoE基因敲除小鼠随机分为模型组、阳性药物组(立普妥组)、通瘀煎低、中、高剂量组各10只,以高脂饲料喂养12 w构建动脉粥样硬化模型。另取10只C57BL/6雄性小鼠为空白组,普通饲料喂养。立普妥组给予立普妥5 mg/(kg·d)灌胃,通瘀煎低、中、高剂量组分别以6.5、13.0、26.0 g/(kg·d)剂量灌胃给药,空白组和模型组以等量生理盐水灌胃。末次给药后,处死取材。苏木素-伊红(HE)染色观察主动脉管腔内粥样斑块;透射电镜摄片观察主动脉管腔内的超微结构变化;酶联免疫吸附试验检测血脂、血液流变学、黏附分子、主动脉组织炎症因子的含量;Western印迹法检测主动脉内细胞内信号传导及转录活化子(STAT)3、磷酸化(p)-STAT3、细胞因子信号转导抑制蛋白(SOCS)1的蛋白表达。结果与空白组相比,模型组主动脉病变相对面积、血脂水平、黏附分子及炎症因子含量显著增加(P<0.01);与模型组相比,立普妥组、通瘀煎低、中、高剂量组主动脉病变相对面积明显降低(P<0.01,P<0.05);通瘀煎高剂量组血脂水平、黏附分子、炎症因子含量、p-STAT3蛋白表达均明显降低,而STAT3、SOCS1的蛋白含量明显升高(均P<0.01)。结论通瘀煎能有效抑制ApoE基因敲除小鼠动脉粥样硬化斑块的形成,其机制可能通过降脂、抑制黏附分子聚集、减少炎症反应,抑制增生信号通路白细胞介素-6/STAT3的激活,有效保护主动脉血管壁,从而发挥抗动脉粥样硬化作用。     

Local adiponectin treatment reduces atherosclerotic plaque size in rabbits

In this study, we investigated the in vivo role of adiponectin, an adipocytokine, on the development of atherosclerosis in rabbits mainly using adenovirus expressing adiponectin gene (Ad-APN) and intravascular ultrasonography. Serum adiponectin concentrations in rabbits after Ad-APN local transfer to abdominal aortas increased about nine times as much as those before transfer (P < 0.01), about ten times as much as the levels of endogenous adiponectin in adenovirus expressing beta-galactosidase gene (Ad-beta gal) treated rabbits (P < 0.01), and about four times as much as those in the aorta of non-injured rabbits on a normal cholesterol diet (P < 0.01). Ultrasonography revealed a significantly reduced atherosclerotic plaque area in abdominal aortas of rabbits infected through intima with Ad-APN, by 35.2% compared with the area before treatment (P < 0.01), and by 35.8% compared with that in Ad-beta gal-treated rabbits (P < 0.01). In rabbits infected through adventitia, Ad-APN treatment reduced plaque area by 28.9% as compared with the area before treatment (P < 0.01) and 25.6% compared with that in Ad-beta gal-treated rabbits (P < 0.01). Adiponectin significantly suppressed the mRNA expression of vascular cell adhesion molecule-1 (VCAM-1) by 18.5% through intima transfer (P < 0.05) and 26.9% through adventitia transfer (P < 0.01), and intercellular adhesion molecule-1 (ICAM-1) by 40.7% through intima transfer (P < 0.01), and 30.7% through adventitia transfer (P < 0.01). However, adiponectin had no effect on the expression of types I and III collagen. These results suggest that local adiponectin treatment suppresses the development of atherosclerosis in vivo in part by attenuating the expression of VCAM-1 and ICAM-1 in vascular walls.     

Thrombosis formation on atherosclerotic lesions and plaque rupture

Atherosclerosis is a silent chronic vascular pathology that is the cause of the majority of cardiovascular ischaemic events. The evolution of vascular disease involves a combination of endothelial dysfunction, extensive lipid deposition in the intima, exacerbated innate and adaptive immune responses, proliferation of vascular smooth muscle cells and remodelling of the extracellular matrix, resulting in the formation of an atherosclerotic plaque. High‐risk plaques have a large acellular lipid‐rich necrotic core with an overlying thin fibrous cap infiltrated by inflammatory cells and diffuse calcification. The formation of new fragile and leaky vessels that invade the expanding intima contributes to enlarge the necrotic core increasing the vulnerability of the plaque. In addition, biomechanical, haemodynamic and physical factors contribute to plaque destabilization. Upon erosion or rupture, these high‐risk lipid‐rich vulnerable plaques expose vascular structures or necrotic core components to the circulation, which causes the activation of tissue factor and the subsequent formation of a fibrin monolayer (coagulation cascade) and, concomitantly, the recruitment of circulating platelets and inflammatory cells. The interaction between exposed atherosclerotic plaque components, platelet receptors and coagulation factors eventually leads to platelet activation, aggregation and the subsequent formation of a superimposed thrombus (i.e. atherothrombosis) which may compromise the arterial lumen leading to the presentation of acute ischaemic syndromes. In this review, we will describe the progression of the atherosclerotic lesion along with the main morphological characteristics that predispose to plaque rupture, and discuss the multifaceted mechanisms that drive platelet activation and subsequent thrombus formation. Finally, we will consider the current scientific challenges and future research directions.     

Antagonism of RANTES receptors reduces atherosclerotic plaque formation in mice

Increasing evidence supports the involvement of inflammation in the early phases of atherogenesis. Recruitment of leukocytes within the vascular wall, controlled by chemokines, is an essential process in the development of this common disease. In this study, we report that blocking a chemokine pathway in vivo with the CC chemokine antagonist Met-RANTES reduces the progression of atherosclerosis in a hypercholesterolemic mouse model. The reduction of lesions was correlated with a diminution of expression of several major chemokines and chemokine receptors, a decrease in leukocyte infiltration, and an increase of collagen-rich atheroma, features associated with stable atheroma. Treatment was well tolerated and serum lipid profiles were not affected. Whereas genetically engineered mice with deletion of either a CC chemokine or its receptor have demonstrated resistance to disease, to our knowledge, this is the first demonstration that treatment with a chemokine receptor antagonist limits the progression of atherosclerosis in vivo. Thus, our findings indicate that blockade of chemokine receptor/ligand interactions might become a novel therapeutic strategy to reduce the evolution of this common disease.     

Effect of broad-spectrum matrix metalloproteinase inhibition on atherosclerotic plaque stability

OBJECTIVE: Matrix metalloproteinases (MMPs) form a large family of enzymes that collectively can degrade all components of the extracellular matrix, and there is widespread interest in developing MMP inhibitors for the prevention of atherosclerotic plaque rupture. We have therefore investigated the effects of a broad-spectrum MMP inhibitor, RS-130830, on plaque development and stability. This compound inhibits a wide range of MMPs at concentrations below 20 nmol/L. METHODS: Apolipoprotein E knockout mice were fed a Western diet. Dietary administration of RS-130830 commenced at the same time as fat-feeding and continued for 8, 12, 26 or 36 weeks. To investigate the effect of RS-130830 on established plaques, mice were fed high-fat diet for 16 weeks before initiation of drug treatment and were terminated 20 weeks after this. RESULTS: Broad-spectrum MMP inhibition was associated with a significant increase in plaque area, but there was no change in the incidence of plaque rupture. There were unfavourable changes in phenotypic characteristics associated with plaque instability, such as an increased lipid content and decreased collagen content. CONCLUSIONS: These data suggest that broad-spectrum MMP inhibition RS-130830 does not have a beneficial effect on atherosclerosis in the apolipoprotein E knockout mouse model, and indicate that more selective compounds would be preferable.     

Upstream regulation of matrix metalloproteinase by EMMPRIN; extracellular matrix metalloproteinase inducer in advanced atherosclerotic plaque

From experimental and clinical studies it is known that matrix conservation and degradation by matrix metalloproteinases (MMPs) plays a major role in plaque progression and destabilization with related onset of acute vascular events such as acute coronary syndromes or cerebrovascular accidents. Recently, extracellular MMPs inducer (EMMPRIN) has been reported to induce and activate the expression of MMPs in myocardium and plays an important role in the ventricular remodeling in human heart failure. Similarly to heart failure myocardium, EMMPRIN may be expressed in human atheroma and play a role in the extracellular matrix (ECM) remodeling and atherogenic cell differentiation. This study was designed to investigate the possible biological role of EMMPRIN in human atheroma. Immunohistochemical analysis for MMPs and EMMPRIN was performed on human carotid endarterectomy specimens and control aortas. EMMPRIN showed significant immunoreactivity in human atherosclerotic carotid lesions, and was colocalized with macrophage/monocyte infiltrates in atherosclerotic intima, plaque itself and vascular smooth muscle cells (VSMCs). Zymography and Western blot analysis revealed EMMPRIN expression in the carotid atheromas, but not in the control aortas. Human bone marrow monocytes, which were cultured with atherogenic proinflammatory cytokine stimulation revealed increased EMMPRIN and MMPs expressions. ECM remodeling is under the control of induction and inhibition of matrix degrading protease and the novel MMP inducer, EMMPRIN may play a role in influx and differentiation of monocytes and destabilizing atheroma.     

慢性内质网应激诱导的凋亡在动脉粥样硬化斑块形成中的作用

内质网应激(ERS)与促进动脉粥样硬化(As)的非动脉壁系统和动脉壁系统因素均密切相关。未折叠蛋白反应(UPR)作为ERS长期激活的标志,可导致细胞的病理状态及组织功能受损。已有大量研究表明As斑块内的细胞,尤其是易损斑块区域的内皮细胞和巨噬细胞均表现有UPR被慢性激活。病理性的慢性ERS通过诱导细胞(内皮细胞、巨噬细胞及平滑肌细胞)凋亡而促进坏死核形成,激活炎症信号通路,影响易损斑块的形成与稳定性,有重要的促As效应。造成慢性ERS的应激源:氧化应激、氧化型胆固醇、细胞内高水平胆固醇及饱和脂肪酸等在As病程中表现明显,且在肥胖、胰岛素抵抗及糖尿病等促进As临床病程的因素中更为突出。近年研究已经部分揭示了ERS促As易损斑块形成的机制及体内的相关性,为ERS药物靶向性治疗途径提供了思路,但仍需大量深入的研究才能转化为具有临床意义的防治方法。     

动脉粥样硬化易损斑块快速进展机制与临床治疗进展

心血管疾病居我国居民死亡原因首位,动脉粥样硬化(As)是冠心病的主要病理基础。易损斑块是动脉粥样硬化斑块中发展迅速、具有血栓形成倾向的不稳定性高危斑块,快速进展的斑块可引起恶性临床事件,是急性冠状动脉综合征及脑卒中的主要病理机制。现有的As干预策略可以减少30%～45%的急性心肌梗死及脑卒中,但残存风险依然较大。因此深入探究动脉粥样硬化易损斑块快速进展机制及影响因素对预防和治疗心血管事件具有重要的意义。