载脂蛋白J对氧化低密度脂蛋白引起的心肌细胞损伤的影响

发布时间：2018-04-21 11:10

  本文选题：载脂蛋白J + ox-LDL　； 参考：《河北北方学院》2017年硕士论文

【摘要】：现如今心血管疾病频发,已成为制约人们健康的一大难题。心血管疾病类型众多,高频发的疾病包括缺血性心肌病、高血压以及动脉粥样硬化(atherosclerosis,AS)等。通过调查,多数的心血管疾病和AS之间均有密切的关联。国内外业界人士从未停止过对冠心病的研究,据最新调研结果显示,多数不必要的活性氧自由基(reactive oxygen species,ROS)是种种冠心病产生因素都可以激发的,活性氧进而会产生诱发AS的病理过程。氧化低密度脂蛋白(ipoproteidensity low oxidizednl,ox-LDL)的功能多样,不但可损伤血管内皮、诱发细胞产生细胞因子,而且会同时造成细胞凋亡。载脂蛋白J(Apolipoprotein-J,ApoJ)是多存于人体组织与体液中的新型多功能分泌型的糖蛋白质。它既可参与精子成熟、组织重构、和补体活化的调控等生理病理过程,又可在细胞凋亡和脂质运输中发挥作用。载脂蛋白J在抑制凋亡细胞方面有显著作用,因此可保护心脏受损时的细胞。但是值得注意的是,即使载脂蛋白J与ox-LDL二者之间存在的联系对于心肌细胞的生长与死亡起着决定性的作用,仍未完全引起足够的重视。目的:阐明ox-LDL对心肌细胞的影响及细胞内信号转导机制,并探讨高表达ApoJ是否可降低ox-LDL对新生大鼠心室肌细胞(neonatal rat ventricular cells,NRVCs)的影响。方法:利用带有ApoJ基因的腺病毒感染NRVCs使ApoJ高表达。用CaMKⅡ抑制剂KN93和SOD类似物Mn(ⅡI)TBAP进行前期预处理,划分心肌细胞为:正常对照组、ox-LDL组、ox-LDL联合ApoJ组、ApoJ组、ox-LDL联合KN93组、ox-LDL联合Mn(ⅡI)TBAP组、H2O2组、H2O2+ApoJ组。通过MTT检测法和Caspase-3/7活性检测试剂盒检测心肌细胞活性和凋亡变化;利用Western-blot检测心肌细胞Nox2/gp91phox、P47和CaMKⅡ表达情况,利用CaMKⅡ活性检测试剂盒检测心肌细胞CaMKⅡ活性。结果:ox-LDL可引起细胞损伤,具体表现为caspase3/7活性增加,caspase-3的表达增强以及细胞活性下降。而APOJ高表达能够显著降低ox-LDL造成的细胞损伤。ox-LDL能够增加ROS的产生,具体表现为Nox2/gp91phox和P47表达升高,而ApoJ可以抑制ox-LDL的表达。此外,APOJ高表达能够降低ox-LDL引起的CaMKⅡ表达,同时显著抑制ox-LDL介导的CaMKⅡ活性上调。CaMKⅡ抑制剂KN93降低ApoJ抗氧化作用,阻碍APOJ对ox-LDL损伤的保护作用。活性氧清除剂(ROS)Mn(ⅡI)TBAP也弱化了CaMKⅡ的表达和ox-LDL诱导的活性增加,并通过减弱ox-LDL诱导的细胞损伤显示出与ApoJ类似的结果。结论:1.ApoJ可减少ox-LDL诱导的心肌细胞凋亡,减轻心肌细胞损伤;2.ox-LDL能利用氧化应激,通过ROS/oxCaMKⅡ通路引起细胞损伤;3.高表达ApoJ通过抑制ROS/oxCaMKⅡ信号通路降低OX-LDL对心肌细胞的毒性作用。
[Abstract]:Nowadays, cardiovascular disease has become a major problem restricting people's health. There are many types of cardiovascular diseases, such as ischemic cardiomyopathy, hypertension and atherosclerosis. By investigation, most cardiovascular diseases and as are closely related. People in the industry at home and abroad have never stopped their research on coronary heart disease. According to the latest research results, most unnecessary reactive oxygen speciesros can be stimulated by various factors of coronary heart disease. Reactive oxygen species, in turn, produce pathological processes that induce as. Oxidized low density lipoprotein (LDL) low oxidizednlox-LDLs can not only damage vascular endothelium and induce cytokines, but also induce apoptosis. Apolipoprotein Apolipoprotein-ApoJ (ApoJ) is a new type of multifunctional secretory sugar protein which exists in human tissues and body fluids. It not only participates in the physiological and pathological processes of sperm maturation, tissue remodeling, and complement activation, but also plays an important role in apoptosis and lipid transport. Apolipoprotein J plays a significant role in inhibiting apoptotic cells and thus protects cells from heart damage. But it is worth noting that even though the relationship between apolipoprotein J and ox-LDL plays a decisive role in the growth and death of cardiomyocytes, it has not been paid enough attention to. Aim: to elucidate the effects of ox-LDL on cardiac myocytes and the mechanism of intracellular signal transduction, and to explore whether the high expression of ApoJ can reduce the effect of ox-LDL on neonatal rat ventricular cells in neonatal rats. Methods: adenovirus containing ApoJ gene was used to infect NRVCs to make ApoJ overexpression. CaMK 鈪，

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