【作者】 张艳；

【导师】 孙雷；

【作者基本信息】 大连医科大学 ， 病理学与病理生理学， 2008， 硕士

【摘要】 目的:探讨冠脉粥样硬化斑块中Flt-4的表达与巨噬细胞凋亡的相关性以及新血管的形成情况,并分析二者与斑块稳定性之间的内在联系。方法:从79例尸检标本中获得79个冠状动脉左前降支的标本,通过HE染色后进行光镜观察,按有无脂质中心及其大小是否超过所占斑块面积的40%,将斑块分为稳定组(≤40%,32例)、不稳定组(﹥40%,35例)和正常对照组(12例)。采用免疫组织化学的方法检测斑块内Flt-4、Caspase-3、VEGF-C、VEGF-D、Flk-1、CD34及CD68各自的表达情况,并采用末端脱氧核苷酸转移酶介导的dUTP缺口末端标记(TUNEL)技术检测三组冠脉标本的细胞凋亡情况,比较稳定斑块和不稳定斑块中巨噬细胞凋亡的不同情况。结果:①免疫组织化学结果显示,不稳定斑块中Flt-4、Caspase-3、VEGF-C、VEGF-D、Flk-1及CD34的表达与稳定斑块的比较差异均有统计学意义(P<0.05),不稳定斑块高于稳定斑块,而正常组几乎全部无表达。②斑块中Flt-4、VEGF-C和VEGF-D在巨噬细胞中均有表达,但在内皮细胞只有VEGF-C和VEGF-D表达,无二者的受体Flt-4的表达。在不稳定斑块中,Flt-4主要表达于巨噬细胞的胞浆中,个别细胞核也有部分表达,VEGF-D和Flk-1也主要由巨噬细胞表达。③斑块中Flt-4的表达与Caspase-3、VEGF-C、VEGF-D三者的表达均呈正相关关系(r值依次为0.742、0.764、0.839,p<0.05), CD34的表达与Flk-1的表达之间也呈正相关(r=0.799,p<0.05)。④不稳定斑块中巨噬细胞凋亡的发生率与稳定斑块的比较差异有统计学意义(p<0.05),不稳定斑块高于稳定斑块。TUNEL阳性率与Flt-4的表达阳性率呈显著的正相关(r=0.852,p<0.05)。⑤显微镜结果显示,不稳定斑块中巨噬细胞和新生血管的数量都多于稳定斑块,且多分布于斑块的肩部。结论:在冠脉粥样硬化斑块中,巨噬细胞表达VEGF-C、VEGF-D极其受体Flt-4和Flk-1,Flt-4介导巨噬细胞发生凋亡,从而促进了斑块不稳定性的进展;Flk-1在新血管形成的过程中起非常重要的作用,斑块内新血管的形成亦增加了斑块的不稳定。更多还原

【Abstract】 Aim:To investigate angiogenesis and the corralation btween Flt-4 expree- ssion and macrophage apoptosis,and analyze their Relationship with coronary plaque stability.Methods:Seventy-nine left anterior descending coronary arteries from 79 autopsied cases were enrolled.Analyzed by light microscope after the process of HE staining,then the Samples were divided into threen groups: stable plaque group(32 samples),unstable plaque group(35 samples) and normal coronary arteries(12 samples).The lipid core size of unstable plaque exceeds 40% of plaque area,while stable group is just the opposite.The exppressions of Flt-4, Caspase-3, VEGF-C, VEGF-D, Flk-1, CD34 and CD68 were detected with immunohistochemistory. Cell apoptosis was in site detected with the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL).Analyzed the changes of stable and unstable plaques in cell morphology with light microscope,and compared their differeces in apoptosis and angiogenesis.Rsults:①Significant differeces in the expressions of Flt-4, Caspase-3, VEGF-C, VEGF-D, Flk-1, CD34 and CD68 were shown in comparing stable and unstable plaques respectively(p<0.05).Their expression levles are higher in unstable plaques than those in stable ones,and no exoression in normal coronary arteries.②Macrophages within inflammatory perivascular regions coexpressed Flt-4,VEGF-C and VEGF-D.Interestingly, microvascular endothelial cells stained positive for VEGF-C and VEGF- D,but not for Flt-4.In unstable plaques Flt-4, VEGF-C and VEGF-D are mainly expressed in macrophages. Moreover,Flt-4 was shown positive almost in macrophage cytoplasm,indeividually in several nucleuses.③There were positive correlations of Flt-4 expression with the expressions of Caspase-3, VEGF-C and VEGF-D(Caspase-3 r=0.742,p<0.05; VEGF-C r=0.764,p<0.05; VEGF-D r=0.839,p<0.05;),and also of CD34 with Flk-1 (r=0.799,p<0.05;).④The rate of apoptotic macrophages in unstable plaques was higher than that in stable ones(p<0.05). Moreover,positive associations between the rate of positive TUNEL results and Flt-4 expression intensity showed in Spearman tests(r=0.852,p<0.05;).⑤The counts of apoptotic macrophages and new vessels in unstable plaques both are more than those in stable,and most of them distribute in shoulders of plaques.Conclusion:Human macrophages express VEGF-C , VEGF-D and their receptors Flt-4 and Flk-1 within advanced atherosclerotic lesions. Flt-4 mediates macrophage apoptosis and may this way alter plaque stability.Flk-1 is benefit to angiogenesis,and the after is an important contributor of progression and destabilization of atherosclerosis coronary plaque.更多还原