老年人腹主动脉瘤血管平滑肌细胞相关蛋白表达及巨噬细胞浸润的病理学特点

目的 观察血管平滑肌细胞(VSMC)表达变化及巨噬细胞浸润在老年人腹主动脉瘤中的病理学特点. 方法 对15例老年人腹主动脉瘤与6例正常腹主动脉组织行HE染色、VanGieson法染色和免疫组织化学染色.用免疫组织化学染色检测α-平滑肌肌动蛋白(α-SMA)、组织蛋白酶B及CD68蛋白表达. 结果 老年人腹主动脉瘤病变处胶原容积百分比(9.3±1.9)%,较正常主动脉的(5.3±1.8)%增高(P＜0.05).老年人腹主动脉瘤中组织蛋白酶B和CD68的表达增强分别为0.38+0.07和0.51±0.12,α-SMA表达减弱为0.23±0.05,与正常腹主动脉(分别为0.13±0.06和0.01±0.01,0.33±0.05)比较.差异有统计学意义(P＜0.05). 结论 VSMC相关蛋白表达水平改变及巨噬细胞浸润可能参与了老年人腹主动脉瘤血管壁的破坏.     

组织蛋白酶B在人腹主动脉瘤中的表达及其意义

目的:研究组织蛋白酶B在人腹主动脉瘤(AAA)中的表达情况,以探讨其在AAA发生发展中的作用。方法:对17例AAA患者(AAA组)和6例正常腹主动脉尸体供肾者(正常腹主动脉组)的腹主动血管标本行苏木精-伊红染色、Van Gieson法染色和免疫组化技术染色,研究组织蛋白酶B对血管中膜的改变情况。结果:与正常主动脉组相比,在Van Gieson法染色中可见AAA组胶原含量有不同程度的增加。α-平滑肌肌动蛋白在AAA组和正常主动脉组中表达的平均吸收度分别是0.2634±0.0530和0.3335±0.0549,其表达水平明显降低(P<0.01)。组织蛋白酶B的平均吸收度2组分别为0.3465±0.0479和0.1306±0.0579(P<0.01)。结论:AAA患者血管平滑肌细胞表达的组织蛋白酶B水平增加,参与了血管壁的破坏和重建过程。     

整合素β3在大鼠腹主动脉瘤中的表达及意义

目的 观察整合素β3在大鼠腹主动脉瘤模型中的表达情况,探讨其在腹主动脉瘤发病中的意义.方法 弹力蛋白酶灌注法构建大鼠腹主动脉瘤模型并测量腹主动脉直径,计算直径扩张度;HE染色观察主动脉病理改变;免疫组织化学技术和实时定量PCR技术分别从蛋白水平和基因水平检测主动脉组织中整合素β3的相对表达量.结果 腹主动脉瘤组主动脉扩张度明显高于生理盐水组和正常组(3.689±0.443比1.175±0.159和1),差异有统计学意义(P＜0.05);HE染色腹主动脉瘤组主动脉结构紊乱并有炎症细胞浸润;免疫组织化学结果显示整合素β3在腹主动脉瘤组、生理盐水组和正常组中的表达分别为0.33±0.07、0.20±0.06和0.19±0.07(P＜0.05);整合素β3mRNA在以上三组的相对表达量为36.23±5.65、1.14±0.30和1,差异有统计学意义(P＜0.05).结论 整合素β3的高表达可能参与腹主动脉瘤的发生发展.     

腹主动脉瘤发病的新祸首——溶酶体组织蛋白酶

腹主动脉瘤(Abdominal aortic aneurysm,AAA)是肾下腹主动脉直径≥3 cm,主动脉直径>正常直径50%以上的血管致死性疾病.腹主动脉瘤的组织病理学改变主要为腹主动脉壁细胞外基质(extracellular matrix,ECM)重塑,迄今缺乏特异针对腹主动脉瘤的药物治疗.近年研究证实定位于溶酶体的组织蛋白酶(Cathepsins)通过促进血管炎症、诱导中膜平滑肌细胞凋亡、增加血管新生和激活其它蛋白水解酶的活性,导致血管壁重塑而促进腹主动脉瘤的形成.Cathepsins有望成为腹主动脉瘤治疗的新靶点.     

小鼠腹主动脉瘤模型中krüppel样因子5和组织蛋白酶Z的表达及其意义

目的观察Krüppel样因子5(krüppel-like factor 5,KLF5)和组织蛋白酶Z(cathepsin Z,Cts Z)在CaPO4诱导的小鼠腹主动脉瘤模型中的表达情况及其意义。方法选择雄性C57BL/6小鼠16只,随机分为对照组和实验组,每组8只。CaPO4诱导腹主动脉瘤模型并测量腹主动脉直径;苏木精-伊红染色观察主动脉病理变化;血管弹力纤维染色分析弹性纤维断裂程度;免疫组织化学和实时定量PCR方法分别从蛋白和基因水平检测主动脉组织中KLF5和Cts Z相对表达量。结果实验组小鼠术后膨胀度明显大于对照组(2.573±0.790 vs 1.129±0.168,P0.01)。与对照组比较,实验组小鼠血管弹性纤维断裂更为严重,且KLF5和Cts Z mRNA和蛋白在腹主动脉组织中表达明显升高,差异有统计学意义(P0.05,P0.01)。结论在CaPO4诱导损伤的小鼠腹主动脉组织中KLF5和Cts Z表达升高,并促进血管病理性重构。     

缺氧诱导因子1α及其相关基因在腹主动脉瘤中的表达

为了研究缺氧诱导因子 1α及其相关基因在腹主动脉瘤中的表达 ,选取腹主动脉瘤标本 2 2例 ,以 5例正常腹主动脉作对照 ,检测缺氧诱导因子 1αmRNA及蛋白的表达 ,检测血管内皮生长因子及促红细胞生成素的表达及微血管密度。结果发现 ,腹主动脉瘤组织中缺氧诱导因子 1αmRNA及蛋白表达明显高于正常腹主动脉 (P <0 .0 1) ;血管内皮生长因子和促红细胞生成素表达亦明显增强 (P <0 .0 1)。缺氧诱导因子 1α表达主要分布在腹主动脉瘤中层血管平滑肌细胞及外膜处 ,与血管内皮生长因子和促红细胞生成素的分布部位基本一致。腹主动脉瘤中微血管密度明显增加 (P <0 .0 1) )。结果提示 ,缺氧诱导因子 1α在腹主动脉瘤发病过程中可能发挥重要作用 ,其作用机制可能是通过调控血管内皮生长因子和促红细胞生成素的表达而实现的     

腹主动脉瘤血管平滑肌细胞凋亡和自噬研究

目的探讨血管平滑肌细胞(SMC)凋亡和自噬与腹主动脉瘤(AAA)发病的关系。方法采用原位末端DNA标记(TUNEL)技术观察AAA和人正常主动脉组织中SMC凋亡的情况,并用免疫组织化学分析其中LC3的蛋白表达。提取AAA和正常主动脉组织RNA,采用RT-PCR方法检测其中与自噬相关的基因Beclin1、Atg4b、Bnip3、Vps34的表达。结果 AAA组织中凋亡的SMC明显高于正常主动脉组织(P0.05);LC3蛋白在AAA中的表达高于正常主动脉组织(P0.05);AAA中Beclin1、Atg4b、Bnip3、Vps34表达水平明显高于正常主动脉组织(P0.05)。结论 SMC凋亡和自噬在AAA的发病中起重要作用。     

脉心康对载脂蛋白E基因敲除小鼠主动脉核因子κB和基质金属蛋白酶9表达的调控

目的观察脉心康对载脂蛋白E基因敲除小鼠主动脉核因子κB、基质金属蛋白酶9mRNA表达水平的调控作用。方法6周龄载脂蛋白E基因敲除小鼠,随机分为高脂血症组(模型组)、洛伐他汀组及脉心康组,相同遗传背景的同龄正常C57BL6J小鼠为正常对照组。原位杂交观察各组主动脉核因子κB和基质金属蛋白酶9mRNA表达的强度。结果各给药组与模型组比较,核因子κBmRNA、基质金属蛋白酶9mRNA阳性细胞表达率均明显降低(P<0.01)。光镜下发现正常对照组主动脉壁内皮细胞、平滑肌细胞胞质内核因子κBmRNA、基质金属蛋白酶9mRNA阳性表达细胞极少见;模型组主动脉壁内皮细胞、平滑肌细胞胞质内阳性表达的棕褐色颗粒较多见,且棕褐色颗粒染色均较深;脉心康组主动脉壁可见内皮细胞、平滑肌细胞胞质内阳性表达的棕褐色颗粒,但远较模型组少,棕褐色颗粒染色深浅较均匀。结论脉心康可降低载脂蛋白E基因敲除小鼠主动脉核因子κB、基质金属蛋白酶9mRNA表达,发挥抗动脉粥样硬化、稳定斑块的作用。     

血管紧张素转化酶2和血管紧张素1-7在兔动脉粥样硬化斑块中的表达

目的观察血管紧张素转化酶2和血管紧张素1-7在兔动脉粥样硬化斑块中的表达,确定斑块中表达血管紧张素转化酶2蛋白的细胞类型。方法雄性新西兰大白兔动脉内膜损伤术后饲以高脂饲料4个月建立动脉粥样硬化模型。取腹主动脉组织进行免疫组织化学染色。结果血管紧张素转化酶2和血管紧张素1-7蛋白在兔腹主动脉斑块中表达,大多数的巨噬细胞、部分平滑肌细胞和内皮细胞都表达血管紧张素转化酶2。血管紧张素1-7主要在血管紧张素转化酶2阳性区域表达,分布于血管紧张素转化酶2阳性细胞胞外。结论血管紧张素转化酶2和血管紧张素1-7都在兔动脉粥样硬化斑块中表达,血管紧张素转化酶2及血管紧张素1-7在动脉粥样硬化发生发展中的作用值得进一步探讨。     

阿托伐他汀对大鼠血管平滑肌细胞迁移和组织蛋白酶S表达的影响

目的 观察阿托伐他汀对白细胞介素1β诱导的大鼠血管平滑肌细胞迁移及组织蛋白酶S和核因子κB表达的影响.方法 取SD大鼠胸主动脉进行血管平滑肌细胞培养,采用Boyden小室实验评价不同浓度阿托伐他汀对白细胞介素1β诱导大鼠血管平滑肌细胞迁移的影响,用细胞免疫化学和逆转录聚合酶链反应法检测各组组织蛋白酶S和核因子κB表达的变化.结果 与正常对照组相比,白细胞介素1β组血管平滑肌细胞迁移增多,核因子κB和组织蛋白酶s表达明显增加(P<0.01).1 μmol/L和10 μmol/L阿托伐他汀组可呈剂量依赖性地抑制白细胞介素1β所致的细胞迁移以及组织蛋白酶S和核因子κB表达(P<0.01).结论 阿托伐他汀可能通过抑制核因子κB使组织蛋白酶S表达减少,从而抑制血管平滑肌细胞迁移.     

Cathepsin L expression and regulation in human abdominal aortic aneurysm, atherosclerosis, and vascular cells

The cysteine protease cathepsin L is one of the most potent mammalian elastases and collagenases, widely expressed at basal levels in most tested tissues and cell types, and regulated by pro-inflammatory stimuli. The inflammatory arterial diseases abdominal aortic aneurysm (AAA) and atherosclerosis involve extensive vascular remodeling that requires elastolysis and collagenolysis. This study examined the hypothesis that cathepsin L is over-expressed in human AAA and atherosclerotic lesions and its expression in vascular cell types found in these lesions is regulated by pro-inflammatory cytokines. Immunohistochemical and tissue extract immunoblot analysis demonstrated increased expression of cathepsin L in human AAA and atheromata and localized its expression to lesional smooth muscle cells (SMC), endothelial cells (EC), and macrophages. In primary cultured human SMC, EC, and monocyte-derived macrophages, pro-inflammatory cytokines or growth factors induced the expression of cathepsin L and its activity against extracellular collagen and elastin. Patients with coronary artery stenosis (n=65) had higher serum cathepsin L levels than those without lesions detectable by quantitative coronary angiography (n=30) (1.47+/-0.33 ng/ml versus 0.60+/-0.06 ng/ml, p<0.02). A strong correlation between the percent of stenosis of left anterior descending coronary artery and serum cathepsin L levels in patients with stenosis (R=0.542, p<0.0001), also suggests involvement of cathepsin L in these vascular diseases.     

Cathepsin B and its endogenous inhibitor cystatin C in rheumatoid arthritis synovium

OBJECTIVE: To compare the expression of cathepsin B and its endogenous inhibitor cystatin C in synovial tissue of patients with rheumatoid arthritis (RA) and to determine the cell type expressing cystatin C. METHODS: The expression of cathepsin B and cystatin C was studied by immunohistochemistry in synovial tissue of 10 patients with RA and compared to healthy controls. Applying double labeling methods, the expression of cathepsin B was compared to that of cystatin C. To determine the cell type expressing cystatin C, double labeling with anti-CD68 (PG-M1) was performed. RESULTS: Both cystatin C and cathepsin B were strongly expressed in synoviocytes of patients with RA. Furthermore, fibroproliferative tissue at the site of cartilage and bone destruction contained fibroblast-like and macrophage-like cells positive for cystatin C and cathepsin B, whereas normal synovial tissue exhibited only limited expression of these molecules. Osteoclasts revealed positive staining for CD68 and cystatin C, but not for cathepsin B. CONCLUSION: Cystatin C is a product of both macrophage-like and fibroblast-like synoviocytes. The strong expression of both the matrix degrading cysteine proteinase cathepsin B and the cysteine proteinase inhibitor cystatin C in rheumatoid synovium, particularly at the sites of bone and cartilage erosion, suggests that cystatin C--although increased--is not sufficient to prevent matrix degradation by cathepsin B.     

Separation and characterization of macrophages and smooth muscle cells in rabbit atherosclerotic lesions

Atherosclerotic aortic intimas of cholesterol-fed rabbits were enzymatically dispersed into single cells by collagenase and elastase. And monocyte-macrophages (M phi) were separated from smooth muscle cells (SMC), using the ability of M phi to adhere to a plastic dish firmly even in the enzyme solutions. Round or oval, heavily lipid-laden cells, so-called foam cells (FC), belonged to the M phi fraction. M phi-FC showed very strong activity for non-specific esterase using alpha-naphthyl butyrate, while SMC showed little or no activity. Some of the FC were large and multinucleated (multinucleated giant foam cells). They also showed positive non-specific esterase staining and are thought to be derived from M phi. M phi-FC synthesized various proliferate in the medium and the number decreased gradually within several days. Some SMC were heavily lipid-laden; however, they retained their original spindle shape. SMC lost lipid droplets gradually as they proliferated to confluence. SMC from atherosclerotic lesions showed higher proliferative activity than those from normal-appearing medias of atherosclerotic aortas or control aortas. Almost no M phi-FC were obtained from the intima-medias of grossly normal portions of atherosclerotic aortas and control aortas. The present method will be useful for studying the role of these cells in the pathogenesis of atherosclerosis.     

Genetic deficiency of cyclooxygenase-2 attenuates abdominal aortic aneurysm formation in mice

OBJECTIVE: Abdominal aortic aneurysms (AAAs) are characterized by chronic inflammation which contributes to the remodeling and eventual weakening of the vessel wall. Increased cyclooxygenase-2 (COX-2) expression is detected in human aneurysmal tissue and is suggested to contribute to the disease. The aim of the current study was to define the role of COX-2 expression in the development of AAAs, using a model of the disease. METHODS: AAAs were induced in mice by chronic angiotensin II infusion, and were analyzed following 3, 7, 21 or 28 days of the infusion. AAA incidence and severity, together with the expression of inflammatory markers, were compared between abdominal aortas from COX-2-deficient mice and their wild-type littermate controls. RESULTS: The AAA incidence in COX-2 wild-type mice was 54% (13/24), whereas AAAs were not detected in COX-2-deficient mice (0/23) following 28 days of angiotensin II infusion. The genetic deficiency of COX-2 also resulted in a 73% and 90% reduction in AAA incidence following 7 and 21 days of angiotensin II infusion, respectively. In COX-2 wild-type mice, COX-2 mRNA expression in the abdominal aorta was induced by angiotensin II beginning 3 days following initiation of the infusion, which continued throughout progression of the disease. Abundant COX-2 protein expression was detected in medial smooth muscle cells adjacent to the AAAs. The deficiency of COX-2 significantly attenuated mRNA expression in the abdominal aorta of the macrophage marker CD68, and the inflammatory cell recruitment chemokines, monocyte chemotactic protein-1 and macrophage inflammatory protein-1alpha. CONCLUSIONS: Our findings suggest that increased COX-2 expression in smooth muscle cells of the abdominal aorta contributes to AAA formation in mice by enhancing inflammatory cell infiltration.     

Risk of thrombosis in human atherosclerotic plaques: role of extracellular lipid, macrophage, and smooth muscle cell content.

OBJECTIVE--To assess the size of the lipid pool and the number of smooth muscle cells and monocyte/macrophages in human aortic plaques that were intact and to compare the results with those in aortic plaques undergoing ulceration and thrombosis. DESIGN--The lipid pool was measured as a percentage of the total cross sectional area of the plaque. Immunohistochemistry was used to identify cell types (monocytes/macrophages (M phi) by EBM11 and HAM56, smooth muscle cells by alpha actin). The area of the tissue occupied by each cell type was measured by quantitative microscopy in the peripheral (shoulder) area of the plaque and the plaque cap. Absolute counts of each cell type were expressed as the ratio of SMC:M phi. MATERIAL--Aortas were obtained at necropsy from men aged less than 69 years who died suddenly (within 6 hours of the onset of symptoms) of ischaemic heart disease. 155 plaques from 13 aortas were studied. Four aortas showed intact plaques only (group A, n = 31). Nine aortas showed both intact plaques (group B, n = 79) and plaques that were undergoing thrombosis (group C, n = 45). RESULTS--In 41 (91.1%) of the 45 plaques undergoing thrombosis (group C) lipid pools occupied more than 40% of the cross sectional area of the plaque. Only 12 (10.9%) of the 110 intact plaques (groups A + B) had lipid pools of this size. The mean size of the lipid pool in plaques of groups A, B, and C was 12.7%, 27.3% and 56.7% respectively. Compared with intact plaques those undergoing thrombosis contained a smaller volume of smooth muscle cells (2.8% v 11.8%) and a larger volume of monocyte/macrophages (13.7% v 2.9%) in the plaque cap. The ratio of the number of smooth muscle cells to monocytes/macrophages was 7.8 in group A plaques, 4.1 in group B plaques, and 1.0 in group C plaques. This gradient was the result of an absolute increase in monocyte/macrophages and an absolute decrease in smooth muscle cells. CONCLUSIONS--In the aorta ulceration and thrombosis were characteristic of plaques with a high proportion of their volume occupied by extracellular lipid, and in which there was a shift toward a preponderance of monocyte/macrophages compared with smooth muscle cells in the cap.     

胱抑素C基因真核表达载体的构建及在转染的人主动脉平滑肌细胞中的表达

目的克隆人胱抑素C基因及构建胱抑素C基因真核表达载体并研究其在人血管平滑肌细胞中的表达。方法培养人脐静脉内皮细胞系,并从中提取总RNA,采用逆转录聚合酶链反应扩增胱抑素C基因,构建其真核表达载体,双酶切及聚合酶链反应鉴定阳性克隆,转染人血管平滑肌细胞,逆转录聚合酶链反应及Western blot法检测其表达情况。结果成功克隆人胱抑素C基因及构建其真核表达载体,转染后成功高表达。结论克隆人胱抑素C基因及构建其真核表达载体成功,转染人血管平滑肌细胞获得其高表达。     

Abdominal aortic aneurysms: Distribution of elastin,collagen I and III,and intermediate filament proteins desmin and vimentin—A comparison of familial and nonfamilial aneurysms

Summary The aortic walls of patients with abdominal aortic aneurysms (AAA) and of healthy controls were examined for elastin, collagen I and III, and the intermediate filament proteins desmin and vimentin by immunohistochemical, enzyme histochemical, and routine histological techniques. The morphology of the aneurysmatic walls varied considerably from case to case, but many pathological changes were seen in all cases, e.g., extensive atherosclerotic plaques in the intima, prominent alterations in amount and organization of the elastic lamellae in the media, and an increase of connective tissue. Both collagen I and III were present in all the aneurysmatic walls. The smooth muscle cells in all the aortic walls showed a marked heterogeneity with respect to the morphological appearance, the enzyme histochemical features, and the content of desmin and vimentin. Vimentin occurred in some intimal, medial muscle, and adventitial cells of both the controls and the AAA patients. Desmin occurred in some of the intimal, medial, and adventitial muscle cells of both the controls and the AAA patients. All the cells with desmin in the intima and media also contained vimentin. Thus, smooth muscle cells in the walls of both the normal human abdominal aorta and aneurysms contained either vimentin, desmin, or both. This variability may be explained by the presence of different phenotypes of smooth muscle cells and could be of significance for the development of atherosclerosis and aneurysms. Of special interest was the finding that 5 of the 24 AAA patients studied had blood relatives with the same disease, suggesting a hereditary influence. However, no systematic differences between the morphological appearance of the aneurysmatic walls in familial and nonfamilial AAA could be detected.