【作者】 石宁；

【导师】 王明晓； 王春玲；

【作者基本信息】 河北联合大学 ， 内科学， 2011， 硕士

【摘要】 目的:蛋白酶体是细胞内一类重要的蛋白水解酶体系,参与包括细胞信号传递、细胞周期、细胞凋亡等在内的诸多重要事件的调控,进而对炎症、免疫和肿瘤发生等过程产生深远的影响。值得注意的是,该体系在动脉粥样硬化的整个病理生理进程,如内皮功能障碍、泡沫细胞形成、平滑肌细胞增殖、血管重塑等环节中都发挥着重要作用。而其中的β5亚基位于蛋白酶体的核心部分,在蛋白酶体的组装、成熟以及发挥蛋白水解功能中都起主导作用。本研究选取了颈动脉狭窄并行颈动脉内膜切除术患者的动脉粥样硬化斑块,采用免疫组织化学及Western Blot蛋白质定量的分析方法,来研究蛋白酶体β5亚基在人动脉粥样硬化斑块中的表达水平的变化,以期探讨蛋白酶体水平、活性与动脉粥样硬化病变之间的相互关联。方法:选取严重的颈动脉粥样硬化并行颈动脉内膜切除术的患者,取手术切除的动脉粥样硬化斑块组织作为病例组(16例),根据动脉狭窄程度不同,分为核心部分(狭窄>50%,A组)和边缘部分(狭窄≤50%,B组)。选取主动脉瘤患者行主动脉置换术中切除的相对正常的锁骨下动脉、无名动脉作为对照组(4例,C组)。采集患者相关临床资料,如年龄、性别、吸烟史、高血压病史、糖尿病病史、高脂血症病史等,记录各项生化指标。取术中切除的新鲜组织,一部分样本进行10%福尔马林固定、梯度酒精脱水、二甲苯透明、石蜡包埋,制备成切片进行HE染色及免疫组织化学分析;另一部分提取组织总蛋白、进行Western Blot分析。最后对上述结果进行统计学处理,组间比较采用卡方检验,P < 0. 05为有统计学意义。结果:1.与对照相比,病例组呈现较高的高脂血症、糖尿病的比率,并多伴有吸烟史;2.免疫组织化学分析显示,在平滑肌细胞的胞浆及胞核中均存在蛋白酶体β5亚基的阳性信号,且以在胞浆表达为主;3.综合免疫组织化学和Western Blot分析的结果,在病例组和对照组之间,以及在病例组不同类别的患者之间,蛋白酶体β5亚基的表达水平都存在差异:A组(动脉狭窄程度>50%)< B组(动脉狭窄程度≤50%)<C组(正常对照组),即蛋白酶体β5亚基活性在动脉粥样硬化核心斑块中表达明显下降。结论:在动脉粥样硬化斑块中,蛋白酶体β5亚基蛋白质水平显著降低,提示该亚基可能在蛋白酶体介导动脉粥样硬化进展的功能中起主导作用。更多还原

【Abstract】 Objective. Proteasome is a mutiple-unit protease working on non-lysosomal protein degradation in cells. Recent studies have illuted its potential roles in the whole process of atherosclerosis including endothelial dysfunction,formation of foam cells, smooth muscle cell proliferation, and vascular remodeling. This research is designated to evaluate the expression of the proteasomeβ5 subunit in atherosclerotic plaques from patients subjected to aortic replacement surgery.Methods. Take the atherosclerotic plaque tissue, from carotid endarterectomy for carotid stenosis patients, as the case group (16 cases). According to different degrees of arterial stenosis, divided into the core portion (stenosis> 50%, A group) and the edge portion (stenosis≤50%, B group). Carotid endarteriums were obtained from 4 patients undergoing Aortic replacement surgery, select relatively normal arterial intima (Subclavian artery and Innominate artery)as the control group ; Collected clinical data of patients, such as age, sex, smoking history, hypertension, diabetes, hyperlipidemia, and the biochemical indicators. A portion of the sample was fixed in 10% formalin, dehydrationed in gradient alcohol, Transparented in xylene, embedded in paraffin, sections were prepared for HE staining and immunehistochemical analysis. Another part of the tissue was frozened in liquid nitrogen, for extracting Total protein, and Western Blot analysis. Data are expressed as percentage or mean±SE for continuous variables and by percentage for qualitativevariables. The proteasomeβ5 subunit activity variables were compared by use of theχ2 test. Statistical significance was assumed for P<0.05.Results.1.The decrease in the level ofβ5 had something to do with the risks of diabetes、hyperlipidemia and possibility of smoking in the patients we observed; 2.β5 was expressed in all samples, most of which accumulated in cytoplasm with few exceptions in nucleu; 3. There was significant divergence in the expression ofβ5 in different sub-groups of samples: A group (arterial stenosis> 50%)﹤B group (arterial stenosis≤50%)﹤C group (control group).Conclusion. The expression ofβ5 was decreased in the atherosclerotic plaques of patients, implying it might play important roles in the progress of atherosclerosis.更多还原