载脂蛋白E基因敲除小鼠冠状动脉内粥样硬化病灶的研究

目的：研究载脂蛋白E基因敲除( apoE-/-)小鼠冠状动脉内粥样硬化病灶的分布和组成；探讨病灶发生和发展的机理。方法：取60周龄和112周龄的apoE-/-小鼠心脏作连续切片，从冠状动脉在主动脉开口处连续追踪冠状动脉主干和心肌内冠状动脉小分支，行Movat特殊染色，寻找病灶。根据组织切片数计算病灶离冠状动脉开口处的距离和病灶的长度；根据病灶的长度将病灶分为大、中、小3类病灶；用图像分析仪测量血管口径；根据Movat染色结果观察病灶内组成成分。结果：在apoE-/-小鼠冠状动脉内发现从主动脉内直接延续的延伸病灶和在冠状动脉分支内形成的原位病灶；在60周龄和112周龄小鼠冠状动脉延伸病灶的发生率分别为60%和80%；有延伸病灶的冠状动脉外膜有大量炎性细胞浸润。每只apoE-/-小鼠均有原位病灶；原位病灶多发生在左室壁心肌内血管分支处和乳头肌附近；随着原位病灶增大，蛋白聚糖成分减少，细胞内外脂质成分增多；增大的原位病灶可堵塞小血管；在有原位病灶的冠状动脉外膜常可发现有增多的炎性细胞。112周龄apoE-/-小鼠大原位病灶多于60周龄小鼠 (P＜0.05)。结论：apoE-/-小鼠冠状动脉主干和心肌小分支内分别存在着延伸和原位的粥样硬化病灶，随着小鼠周龄增加，病灶增大。动脉外膜炎症和心肌收缩对血管的挤压与病灶的发生和发展有密切关系。     

硫化氢抑制apoE基因敲除小鼠动脉粥样硬化中ICAM-1的表达

目的　探讨硫化氢(H2S)对apoE基因敲除小鼠(apoE-/-小鼠)动脉粥样硬化中细胞间黏附分子-1 (ICAM-1)的调节作用。方法　6周龄雄性C57BL/6J和apoE-/-小鼠分为C57BL/6对照组、apoE-/-组、apoE-/-+硫氢化钠(NaHS)组和apoE-/-+炔丙基甘氨酸(PPG)组,每组各8只,普通饮食饲养10周。硫电极法测定血清中H2S的含量;ELISA法测定血清中ICAM-1的含量;荧光实时定量RT-PCR法测定主动脉组织中ICAM-1 mRNA的表达。油红O染色观察小鼠主动脉根部斑块面积的变化。结果 与C57BL/6J小鼠相比,apoE-/-小鼠血清中H2S的含量明显下降(P 0.01),血清中ICAM-1的含量和主动脉组织中ICAM-1 mRNA的表达明显升高(P 0.01),主动脉根部出现明显斑块;给予NaHS后,apoE-/-小鼠血清中H2S的含量明显升高(P 0.05),血清和主动脉组织中ICAM-1的表达明显降低(P 0.01和P 0.05),动脉粥样斑块明显缩小(P 0.05);给予PPG后,apoE-/-小鼠血清中H2S的含量明显降低(P 0.05),血清和主动脉组织中ICAM-1的表达明显增高(P 0.05和P 0.01),动脉粥样斑块明显增大(P 0.01)。结论　气体信号分子H2S可明显抑制动脉粥样斑块形成过程中ICAM-1的表达与分泌。     

负载HSP60树突状细胞对小鼠动脉粥样斑块影响研究

目的： 探讨负载热休克蛋白60(HSP60)树突状细胞(DC)接种对ApoE-null小鼠粥样硬化斑块的影响。 方法：小鼠髓源性DC体外培养成熟，分别用磷酸缓冲液（PBS）、卵清蛋白（OVA）和HSP60处理，体外检测各组DC的功能；同系小鼠予以高脂饮食16周形成斑块，各组DC用荧光物质标记后，分别经皮接种3次，48 h 后取主动脉HE染色及荧光观察，测血清IL-10、IFN-γ浓度。 结果：体外HSP60及OVA可促进DC表达CD86，而PBS则无此效应。接种小鼠后，HSP60-DC和OVA-DC组血清IFN-γ较PBS-DC组高；而IL-10无明显差别；IFN-γ/IL-10 比值增高。HSP60-DC促使主动脉粥样斑块炎性细胞浸润明显增加，斑块趋于不稳定；OVA-DC则对斑块无显著效应。 结论：HSP60负载的DC可以特异性刺激主动脉粥样斑块炎性反应，诱导炎性细胞因子释放，引起免疫偏移。     

载脂蛋白E基因敲除小鼠动脉粥样硬化早期血管外膜成纤维细胞增殖活性增强

目的:探讨动脉外膜成纤维细胞增殖与早期动脉粥样硬化病灶形成的关系。方法:选择6周龄载脂蛋白E基因敲除[apoE(-/-)]小鼠和野生型C57BL/6小鼠,高脂喂养2、4和10周后,在各个时点处死动物前24 h经腹腔注射5-溴-2-脱氧尿嘧啶(BrdU),后选取升主动脉制备连续切片,通过HE染色观察组织形态学的变化,用免疫组化方法观察不同时点血管外膜及内膜BrdU的表达变化。体外培养高脂喂养2周的apoE(-/-)小鼠和C57BL/6小鼠动脉外膜成纤维细胞,通过BrdU掺入法测定细胞增殖活性,流式细胞术测定细胞周期。结果:体内实验发现apoE(-/-)小鼠高脂喂养2周后,在无可见内膜病灶形成之前,首先在主动脉外膜发现BrdU标记的阳性细胞,之后才在损伤内膜观察到BrdU标记细胞。而C57BL/6小鼠在任何时点都未检测到BrdU标记的细胞。体外实验观察到apoE(-/-)小鼠血管外膜成纤维细胞BrdU标记的细胞数显著多于C57BL/6小鼠(P0.01),apoE(-/-)小鼠血管外膜成纤维细胞S期及G2/M期所占百分比明显高于对照组(P0.05)。结论:血管外膜成纤维细胞增殖可能参与早期动脉粥样硬化病灶形成。     

人冠状动脉粥样硬化斑块内YKL-40、CXCL2、IFN-γ的表达及其与冠心病猝死的关系

目的 探讨YKL-40及其下游炎症信号分子γ干扰素(interferon-γ, IFN-γ)、CXCL2在人冠状动脉粥样硬化斑块内的表达及其与冠状动脉粥样硬化斑块结构、冠状动脉粥样硬化性心脏病(coronary heart disease, CHD)引起猝死的关系。方法 筛选尸检案例库中心脏冠状动脉标本66例，分为3组：CHD组24例、CHD猝死组24例、对照组18例。测量冠状动脉内膜(含病灶)厚度、纤维帽厚度、坏死灶厚度及血管腔狭窄程度4个形态学指标综合评价血管结构；检测冠状动脉粥样硬化斑块内YKL-40及其下游信号分子CXCL2、IFN-γ的表达水平及分布特点；分析冠状动脉粥样硬化斑块内YKL-40表达与冠状动脉粥样硬化斑块结构指标间的相关性，探讨其与SCD的关系。结果 同对照组比较，CHD组和CHD猝死组冠状动脉粥样硬化病灶的内膜厚度和坏死核心增厚、纤维帽变薄、血管狭窄程度增高(P<0.01)。CHD组和CHD猝死组冠状动脉血管YKL-40、CXCL2及IFN-γ的蛋白表达量明显高于对照组，而CHD猝死组高于CHD组(P<0.01)。CHD组和CHD猝死组冠状动脉内膜...     

青心酮防治动脉粥样硬化与内脂素的关系

目的:观察青心酮对ApoE(-/-)小鼠主动脉粥样硬化病变的影响与内脂素的关系。方法:取8只8周龄C57BL/6小鼠为正常对照组;取24只8周龄雄性ApoE(-/-)小鼠,随机分成3组:动脉硬化组(n=8,im,等量生理盐水);青心酮治疗组(n=8,im,10mg·kg-1·d-1);辛伐他汀治疗组(n=8,im,10mg·kg-1·d-1)。所有实验小鼠均饲以"西方类型膳食"饲料至12周。取血检测内脂素、血脂;剪取主动脉根部行冰冻切片,油红O染色观察主动脉粥样硬化病变情况;剪取主动脉根部斑块组织,观察斑块中内脂素的分布情况;行电镜切片,观察青心酮对斑块中平滑肌细胞、内皮细胞的结构影响。结果:青心酮治疗组血清内脂素减少,血脂降低,主动脉粥样硬化病灶形成减少,平滑肌细胞、内皮细胞损伤减轻,斑块中内脂素含量减少。结论:青心酮能减少ApoE(-/-)小鼠主动脉粥样斑块的形成,可能通过抑制内脂素生成而降低血脂发挥其作用。     

人体动脉连续组织切片的计算机三维重建

在Ｉｎｔｅｌ ４０４８６主机下，采用３Ｄ ＶＩＥＷＮＩＸ软件对正常股动不粥样硬化冠状动脉的连续组织切片进行计算机三维重建，重建的动脉图像色泽鲜艳，外形逼真，立体感强，可单独或同时显示粥样硬化斑块，中膜和外膜的外形轮廓有其相互关系，并可进行任意角度旋转和不同方位的断面剖割，较好地实现了对动脉形态结构的三维立体显示，为影像诊断学提供了有价值的形态学资料。     

高脂饮食引起大鼠动脉血管内皮细胞衰老

目的：研究高脂饮食对大鼠血管内皮细胞衰老的影响。方法：大鼠高脂饲料喂养12周后测定血脂的变化,HE染色分析胸主动脉和肾动脉血管结构的改变;胶原酶灌注方法分离胸主动脉和肾动脉血管内皮细胞,应用免疫细胞化学的方法鉴定内皮细胞;应用细胞化学染色的方法检测衰老相关的半乳糖甘酶（senescence-associated β-galactosidase,SA-β-gal）活性。 结果：SD 雄性大鼠高脂饲料喂养12周后,大鼠血浆三酰甘油、总胆固醇、高密度脂蛋白胆固醇水平明显升高, 胸主动脉和肾动脉出现明显的粥样硬化改变;胸主动脉和肾动脉血管内皮细胞SA-β-gal活性明显增加,表现为较强的β-gal染色。结论：高脂饮食引起大鼠胸主动脉和肾动脉粥样硬化改变,动脉血管内皮细胞衰老增加。     

南蛇藤素对ApoE基因敲除小鼠主动脉粥样硬化斑块内CIMO配体表达、巨噬细胞和平滑肌细胞数量的影响

目的：探讨南蛇藤素对高脂饲养ApoE基因敲除小鼠（ApoE^-/-）主动脉粥样硬化斑块内CD40配体表达、巨噬细胞和平滑肌细胞数量的影响。方法：8周龄雄性ApoE^-/-小鼠12只,随机分为南蛇藤素组或二甲基亚砜（DMSO）溶剂对照组,每组各6只。均给以高脂饲养8周,在高脂饲养的后4周,分别给予南蛇藤素2mg&#183;kg^-1&#183;d^-1或相当剂量的DMSO腹腔注射（ip）4周。麻醉处死小鼠后,取小鼠主动脉,以石蜡包埋,行主动脉根部连续切片。免疫组化法检测主动脉粥样硬化斑块内CD40配体、CD68和平滑肌α-actin表达水平,以Image ProPlus6．0软件进行图像分析。结果：与对照组相比,南蛇藤素组主动脉粥样硬化斑块内CD40配体表达显著减少（P〈0．05）;巨噬细胞的阳性率显著降低（P〈0．05）;而两组问动脉粥样硬化斑块内平滑肌细胞的阳性率没有显著差异（P〉0．05）。结论：南蛇藤素可能通过减少ApoE^-/-小鼠粥样斑块内CD40配体的表达和巨噬细胞的聚集,抑制动脉粥样硬化斑块中炎症反应,而发挥稳定动脉粥样硬化斑块的作用。     

瘤内注射MIP-3α对小鼠肝癌生长抑制作用的研究

目的:探讨瘤内注射巨噬细胞炎症蛋白-3α(macrophage inflammatory protein-3α,MIP-3α)能否趋化外周树突状细胞(Dendritic cells,DCs)至肿瘤组织内,诱导特异性免疫应答。方法:成功建立小鼠皮下肝癌模型后随机分为3组,第10天起分别向MIP-3α治疗组、PBS对照组的小鼠皮下肿瘤内注射MIP-3α溶液及PBS,空白对照组小鼠不予任何处理。20天后取肿瘤组织,免疫组化法检测肿瘤内DCs、CD4+、CD8+细胞浸润情况,流式细胞术检测肿瘤内DCs浸润数量及其表型。另外,每组各10只小鼠持续观察,用于绘制肿瘤生长曲线并观察生存时间。结果:①MIP-3α治疗组的小鼠肿瘤内浸润的CD4+、CD8+细胞及DCs数量均显著高于其他两组。②MIP-3α治疗组小鼠肿瘤内浸润性DCs的CD80、CD86表达率显著高于其他两组(P<0.05)。③MIP-3α治疗组小鼠肿瘤生长速率显著低于对照组(P<0.001),生存时间较对照组明显延长(P<0.05)。结论:①瘤内注射MIP-3α可在小鼠肝癌病灶内趋化、募集外周的树突状细胞,使其摄取并提呈肿瘤抗原,有效诱导针对肝癌细胞的特异性免疫应答。②MIP-3α在小鼠皮下肝癌模型的局部微环境下可能具有促进树突状细胞成熟的作用。     

Vanilloid receptor TRPV1, sensory C-fibers, and activation of adventitial mast cells. A novel mechanism involved in adventitial inflammation

The immunological mechanisms on adventitial inflammation has received much attention, while the contribution of nerves to adventitial inflammation has largely been ignored. Although the mechanism of initial chemotaxis of the adventitial inflammatory cells remains unknown, vascular nerves were frequently found in the inflammatory lesions of coronary adventitia and adventitial mast cells connect with sensory nerve fibers in atherosclerotic coronary arteries. The sensory nerves in contact with adventitial mast cells contained the neuropeptides SP and CGRP. These neuropeptides play an important role in the amplification of tissue injury by the increase of both vascular permeability and neutrophil recruitment, and the term 'neurogenic inflammation' has been coined. Activation of adventitial mast cells, with ensuing release of vasoactive compounds, may cause vasoconstriction in atherosclerotic coronary segments. Therefore, we hypothesize that adventitial vanilloid receptor TRPV1 and sensory C-fibers may play a pistol role for adventitial inflammation.     

Adventitial inflammation: a possible pathogenic link to the instability of atherosclerotic plaque

A variety of cells, including fibroblasts, mast cells, macrophages, and ganglionic cells, are present in coronary artery adventitia. In the infarct-related coronary arteries of myocardial infarction patients, the majority of mast cells are found in the outer layer of the adventitia. Neurogenic stimulation of mast cells in the adventitia of coronary arteries may release vasoactive compounds, such as histamine and leukotrienes, which can contribute to the complex neurohormonal response that leads to abnormal coronary vasoconstriction. Lymphocytes and bacteria are also present mainly in the adventitial layer. Chlamydia pneumoniae is directly involved in the development of adventitial and plaque inflammation (pan-arteritis), leading to plaque rupture. Adventitial O(2)(-) may also play an extensive role in the control of vascular tone. Therefore, adventitial inflammation may play a pivotal role for atherosclerotic lesion development and atheroma instability.     

Adventitial macrophage and lymphocyte accumulation accompanying early stages of human coronary atherogenesis

BackgroundAtherosclerosis is considered a chronic inflammatory disease of the entire arterial wall, including the adventitia. Advanced coronary lesions with lipid cores are associated with adventitial inflammation, but the early inflammatory process in human coronary adventitia is largely unknown. We hypothesized that adventitial inflammatory cell infiltration accompanies the early stages of atherogenesis in human coronary arteries, and it is synchronous with the inflammatory process in the intima.MethodsCoronary artery samples were obtained from 111 forensic autopsy cases aged from 7 to 25 years. Adventitial and intimal macrophages, T lymphocytes and B lymphocytes, and intimal microvessels were detected by immunohistochemical methods and quantified by computerized image analysis. Body height, weight, waist circumference, and the size of mesenteric and omental fat depots were measured.ResultsAdventitial densities of macrophages and T lymphocytes were significantly higher in arteries showing intimal xanthomas than in cases with only scattered intimal macrophages. The xanthoma group also had significantly higher body mass index and larger visceral fat depots. Highest densities of all adventitial cell types were seen in intermediate lesions and fibroatheromas. There were significant positive correlations between intimal and adventitial densities of T cells and B cells in the groups with or without intimal xanthomas, but the positive correlation between intimal and adventitial macrophages was significant only in the group without xanthomas.ConclusionsAdventitial immune-inflammatory cell accumulation accompanies the early stages of coronary atherogenesis in young individuals, and lymphocyte accumulation seems to be synchronous in the intima and adventitia. Macrophage accumulation is also synchronous before xanthomas are seen.     

Activation of adventitial fibroblasts contributes to the early development of atherosclerosis: a novel hypothesis that complements the "Response-to-Injury Hypothesis" and the "Inflammation Hypothesis"

The role of the adventitia in vascular function and vascular lesion formation has been largely ignored. This article introduces the hypothesis that the activation of the adventitia, specifically the fibroblasts, contributes to the formation of intimal atherosclerotic lesions. The evidence for this hypothesis includes: (a) the early proliferative changes seen in fibroblasts found in the adventitia; (b) the increase and the alteration of extracellular matrix deposition in the adventitia; (c) fibroblast differentiation into myofibroblasts and migration into the intima; and (d) fibroblast synthesis and release of cytokines that have potent effects on neighboring smooth muscle and endothelial cells prior to intimal lesion formation. In conclusion, the activation of adventitial fibroblasts is a key regulator of vascular function and structure from the "outside-in" and contributes to the development of atherosclerotic lesions. The outer location of the adventitia makes it a suitable location for drug delivery and gene therapy aimed at preventing and treating atherosclerosis.     

The distribution of adhesion molecules in human atherosclerosis

Chronic inflammatory cells are a recognized component of atherosclerotic plaques at all stages of development. As adhesion molecules play a fundamental role in inflammatory processes, we have carried out an immunohistochemical investigation of the distribution of endothelial leucocyte adhesion molecule-1 (ELAM-1)*, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in human atherosclerotic lesions. Autopsy specimens from abdominal aorta and coronary arteries were obtained from 21 cases within 24 h of death. ELAM-1 and ICAM-1 were consistently expressed by the entire intimal endothelium of normal coronary arteries and also by the intimal endothelium overlying aortic fatty streaks. Both coronary artery and aortic lesions showed strong staining for ICAM-1 on and around macrophages. VCAM-1 was not detected on intimal endothelial cells, but strong staining of adventitial lymphoid aggregates for this molecule was seen. This work suggests a role for ELAM-1 and ICAM-1 in mononuclear cell recruitment during atherogenesis.     

Characterization of fractalkine (CX3CL1) and CX3CR1 in human coronary arteries with native atherosclerosis, diabetes mellitus, and transplant vascular disease

Background: Fractalkine is a novel chemokine that mediates both firm adhesion of leukocytes to the endothelium via CX3CR1 and leukocyte transmigration out of the bloodstream. Fractalkine has recently been shown to play a role in the pathogenesis of acute organ rejection. Since its expression is regulated by inflammatory agents such as LPS, IL-1, and TNF-, fractalkine involvement in atherosclerosis and transplant vascular disease (TVD) is of particular interest. In this study, we characterized the presence of fractalkine and its receptor CX3CR1 in human coronary arteries from normal, atherosclerotic, diabetic, and TVD settings. Method: Polyclonal rabbit antibodies were used to immunostain human fractalkine and CX3CR1 to localize their presence in transverse sections of the proximal left anterior descending and/or right coronary arteries. Slides were scored in a blinded fashion for intensity of staining (0 to 4+) and for localization in vessel walls. Results: Normal coronary arteries showed no fractalkine staining. In atherosclerotic coronary arteries, staining was localized to the intima, media, and adventitia. Within the media, fractalkine expression was seen in macrophages, foam cells, and smooth muscle cells (SMCs). Diabetic vessels showed similar staining patterns to atherosclerotic coronaries, with much stronger staining in the deep intima. Transplanted coronaries showed staining in the endothelium, intima, and adventitia in early disease, and intimal, medial, and adventitial staining in late disease. CX3CR1 staining was seen in the coronary arteries of all cases, with specific localization to regions with fractalkine staining. Conclusion: The distinctive staining patterns in native atherosclerosis, diabetes mellitus with atherosclerosis, and TVD indicate that the expression of fractalkine and CX3CR1 may be important in the pathogenesis of these diseases.     

Monocyte-dependent cell death of T lymphocyte subsets in chronic hepatitis C

Much evidence indicates that atherosclerotic lesions are largely of an inflammatory nature. Activated macrophages and macrophage-derived foam cells laden with cholesterol esters are a major constituent of these lesions and can influence lesion formation via several potential mechanisms. One such mechanism is Fcgamma receptor activation and/or Fcgamma receptor-mediated clearance of immune complexes containing cholesterol, such as lipoprotein immune complexes. That this mechanism contributes to lesion formation would be further supported if Fcgamma receptor expression in arterial lesions were demonstrated. We therefore used monoclonal antibodies and immunocytochemical methods to analyze frozen sections of human arterial lesions for expression of each of the three primary classes of mononuclear phagocyte Fcgamma receptors. Approximately 800 sections of aorta, carotid, and coronary arteries obtained from five elderly donors were analyzed. The presence of macrophages was determined by assaying reactivity of a monoclonal antibody specific to CD163, which is expressed only on cells of the human mononuclear phagocyte lineage. Results indicate that highly cellular preatheromatous lesions contained numerous macrophages in the zone of proliferation that expressed each class of Fcgamma receptor (FcgammaRIA, FcgammaRIIA, and FcgammaRIIIA). Fcgamma receptor-positive cells were also present in medial and adventitial areas. Fcgamma receptor staining was both punctate and diffuse, the latter suggesting that soluble receptors were present in the extracellular matrix. These data further support that Fcgamma receptor-mediated clearance of immune complexes can occur in arterial lesions during atherogenesis. Expression of both the high affinity (FcgammaRIA) and lower affinity (FcgammaRIIA/FcgammaRIIIA) receptors indicates that mono- and multivalent IgG-containing immune complexes could engage Fcgamma receptors and influence lesion formation through several different inflammatory mechanisms triggered by receptor activation.     

Activated myeloid dendritic cells accumulate and co-localize with CD3+ T cells in coronary artery lesions in patients with Kawasaki disease

Emerging evidence implicating the participation of dendritic cells (DCs) and T cells in various vascular inflammatory diseases such as giant cell arteritis, Takayasu's arteritis, and atherosclerosis led us to hypothesize that they might also participate in the pathogenesis of coronary arteritis in Kawasaki disease (KD). Coronary artery specimens from 4 patients with KD and 6 control patients were obtained. Immunohistochemical and computer-assisted histomorphometric analyses were performed to detect all myeloid DCs (S-100(+), fascin(+)), all plasmacytoid DCs (CD123(+)) as well as specific DC subsets (mature myeloid DCs [CD83(+)], myeloid [BDCA-1(+)] and plasmacytoid DC precursors [BDCA-2(+)]), T cells (CD3(+)), and all antigen-presenting cells (HLA-DR(+)). Co-localization of DCs with T cells was assessed using double immunostaining. Significantly more myeloid DCs at a precursor, immature or mature stage were found in coronary lesions of KD patients than in controls. Myeloid DC precursors were distributed equally in the intima and adventitia. Mature myeloid DCs were particularly abundant in the adventitia. There was a significant correlation between mature DCs and HLA-DR expression. Double immunostaining demonstrated frequent contacts between myeloid DCs and T cells in the outer media and adventitia. Plasmacytoid DC precursors were rarely found in the adventitia. In conclusion, coronary artery lesions of KD patients contain increased numbers of mature myeloid DCs with high HLA-DR expression and frequent T cell contacts detected immunohistochemically. This suggests that mature arterial myeloid DCs might be activating T cells in situ and may be a significant factor in the pathogenesis of coronary arteritis in KD.