缺氧预处理诱导延迟心肌保护的机理研究

发布时间：2018-07-31 17:55

【摘要】：缺血预处理(ischemic preconditioning, IPC)对缺血/再灌注心肌的保护作用已在多种属动物在体、离体心脏和心肌细胞上得到证实,该现象可以被缺氧预处理(hypoxic preconditioning, HPC)模拟。预处理的保护作用具有时相性,包括预处理后即刻出现并持续1-3小时的早期保护和12-24小时再度出现并持续24-72小时的延迟保护,其中延迟保护作用具有更重要的临床意义。从预处理心肌保护机制的研究入手,探讨缺血性心脏病防治的新策略,受到基础和临床医学界的高度重视。现有研究结果表明,预处理的延迟保护机理涉及腺苷、内皮源性舒张因子(EDRF)、一氧化氮(NO)等内源性保护介质释放,蛋白激酶C(protein kinase C, PKC)和丝裂素活化蛋白激酶家系(mitogen-activated protein kinases, MAPKs)等细胞信号转导途径激活,以及内源性保护蛋白转录、合成、翻译后修饰改变等多种因素,其中内源性保护蛋白合成上调是延迟保护的关键环节,但目前预处理延迟保护过程中心肌蛋白质组学变化及其细胞信号转导机制尚未完全阐明。本工作证实HPC对乳鼠心肌细胞缺氧/复氧(hypoxia/reoxygenation,H/R)损伤具有延迟保护作用的基础上,进一步研究HPC延迟心肌保护的细胞信号转导机制及其诱导的心肌细胞蛋白质组学变化。具体方法如下: 1、在乳鼠心肌细胞H/R模型上,采用台盼蓝排斥实验检测心肌细胞存活率,以TUNEL法、DNA特异性荧光素染料Hoechst33258染色等方法测定心肌细胞凋亡率,证实缺氧预处理明显减轻24小时后H/R诱导的心肌细胞损伤。 2、Western bolt检测证实,HPC后24h心肌细胞内PKC亚型nPKCε和MAPKs家系成员细胞外信号调节激酶(extracellular signal-regulated
[Abstract]:The protective effect of ischemic preconditioning (ischemic preconditioning, IPC) on ischemic / reperfusion myocardium has been confirmed in many species of animals in vivo. This phenomenon can be simulated by hypoxic preconditioning (hypoxic preconditioning, HPC) in isolated hearts and cardiomyocytes. The protective effects of preconditioning are temporal, including the early protection which appears immediately after pretreatment and lasts for 1-3 hours, and the delayed protection which reappears at 12-24 hours and lasts for 24-72 hours, among which the delayed protection has more important clinical significance. Based on the study of myocardial protection mechanism of preconditioning, a new strategy for prevention and treatment of ischemic heart disease has been paid great attention to in the field of basic and clinical medicine. The results show that the delayed protection mechanism of pretreatment involves the release of endogenous protective mediums, such as adenosine, endothelium-derived diastolic factor (EDRF), nitric oxide (NO), and so on. Protein kinase C (protein kinase C, PKC) and mitogen-activated protein kinase family (mitogen-activated protein kinases, MAPKs) and other cell signal transduction pathway activation, as well as endogenous protection protein transcription, synthesis, post-translational modification and other factors, The up-regulation of endogenous protection protein synthesis is the key link of delayed protection, but the proteomics changes and the mechanism of cell signal transduction in the process of pretreatment delayed protection have not been fully elucidated. Based on the conclusion that HPC has delayed protection against hypoxia / reoxygenation (H / R) injury in neonatal rat cardiomyocytes, the mechanism of cellular signal transduction and the proteomic changes of cardiomyocytes induced by HPC delayed myocardial protection were further studied. The specific methods are as follows: 1. The survival rate of neonatal rat cardiomyocytes was determined by trypan blue rejection test on the H / R model. The apoptotic rate of cardiomyocytes was determined by TUNEL staining and Hoechst33258 staining with DNA-specific fluorescein dye. The results showed that hypoxia preconditioning significantly alleviated the cardiomyocyte injury induced by H / R after 24 hours. 2Western bolt analysis confirmed the formation of nPKC 蔚 and MAPKs subtypes of PKC subtype in cardiomyocytes 24 hours after HPC. Extracellular signal regulated kinase (extracellular signal-regulated)
【学位授予单位】：中国人民解放军军医进修学院
【学位级别】：硕士
【学位授予年份】：2005
【分类号】：R363

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