AMPK通路对急性光损伤模型中视网膜感光细胞的保护作用

发布时间：2018-05-11 22:33

本文选题：AMPK + 蛋白激酶通路　；参考：《大连医科大学》2011年硕士论文

【摘要】：目的:单磷酸腺苷激活的蛋白激酶(AMPK)通路通过抑制能量消耗通路和激活能量再生通路,在能源动态平衡调控中起着中枢性调节作用。AMPK通路在生理刺激(如运动)、激素(如脂联素,瘦素等)、以及病理条件(如缺糖,缺氧,氧化)等情况下可以被激活。作为脂类和血糖代谢调节作用的枢纽,AMPK同时被认为是治疗肥胖、Ⅱ型糖尿病和癌症的关键靶点。一些研究表明AMPK具有神经保护作用,到目前为止,还没有关于AMPK通路对视网膜病变的保护作用方面的研究报道。氧化应激损伤是多种视网膜病变病理变化的诱因。减少和抑制氧化应激和其所诱发的神经元凋亡是目前很多对视网膜保护措施的机理。急性光损伤目前是公认的模拟氧化应激引起的视神经元凋亡的动物模型。本论文的目的旨在研究AMPK通路对视网膜神经元在氧化应激条件下的保护作用和机制。方法:实验用小白鼠以玻璃体内注射或皮下注射AMPK激动剂二甲双胍和PBS对照,连续7天。在急性光损伤模型中,小白鼠被置于4000 lux强光下照射4小时(从8:00pm到12:00am)。在给药或急性光损伤5天后,用视网膜电图(ERG)法记录视网膜感光细胞的功能。组织学研究用于观察给药和或光损伤后视神经元的凋亡情况和组织结构。蛋白印记法和免疫荧光法用于检测小白鼠视网膜内AMPK及其下游通路的激活和表达水平。应用聚合酶链式反应(PCR)测量线粒体DNA拷贝量。结果:玻璃体和皮下注射二甲双胍可以激活视网膜内AMPK通路,并在急性光损伤模型中保护视网膜感光细胞的结构和功能。进一步的研究表明,激活AMP蛋白激酶通路诱导的细胞核和线粒体编码基因的表达水平增加可能是其保护作用的机制。结论:通过实验我们证明皮下注射二甲双胍可以激活视网膜内的AMPK蛋白激酶通路,说明二甲双胍可以通过血-视网膜屏障。而且,我们的研究发现,激活AMPK通路可以强烈保护视神经元,避免氧化应激损伤诱导的神经元凋亡。这些实验结果表明激活AMPK蛋白激酶通路,增加线粒体损伤修复或生物合成,可能成为治疗或延迟视网膜退行性变的新方法。
[Abstract]:Aim: adenosine monophosphate activated protein kinase (AMPK) pathway inhibits energy consumption and activates energy regeneration pathway. AMPK pathway plays a central role in the regulation of energy homeostasis. AMPK pathway can be activated under physiological stimulation (such as motor stimulation, hormones (such as adiponectin, leptin, etc.), and pathological conditions (such as glucose deficiency, hypoxia, oxidation). AMPK, which acts as a key regulator of lipid and glucose metabolism, is also considered a key target for the treatment of obesity, type 2 diabetes and cancer. Some studies have shown that AMPK has neuroprotective effect, so far, there have been no reports on the protective effect of AMPK pathway on retinopathy. Oxidative stress injury is the inducement of pathological changes of various retinopathy. Reduction and inhibition of oxidative stress and neuronal apoptosis induced by oxidative stress are the mechanisms of many protective measures for retina. Acute light injury is recognized as an animal model of apoptosis of optic neurons induced by oxidative stress. The aim of this study was to investigate the protective effect and mechanism of AMPK pathway on retinal neurons under oxidative stress. Methods: rats were treated with intravitreous injection or subcutaneous injection of AMPK agonist metformin and PBS for 7 days. In the acute light injury model, the mice were exposed to 4000 lux intense light for 4 hours (from 8:00pm to 12: 00 amps). The function of retinal photoreceptor cells was recorded by electroretinogram (ERG) 5 days after administration or acute light injury. Histological study was used to observe the apoptosis and structure of optic neurons after drug administration or light injury. Protein imprinting and immunofluorescence were used to detect the activation and expression of AMPK and its downstream pathway in rat retina. Mitochondrial DNA copies were measured by polymerase chain reaction (PCR). Results: vitreous and subcutaneous injection of metformin could activate the AMPK pathway in the retina and protect the structure and function of the photoreceptor cells in the acute light injury model. Further studies suggest that the increased expression of nuclear and mitochondrial coding genes induced by activation of AMP protein kinase pathway may be the mechanism of its protective effect. Conclusion: subcutaneous injection of metformin can activate the AMPK protein kinase pathway in the retina, suggesting that metformin can pass the blood-retinal barrier. Furthermore, we found that activation of AMPK pathway can strongly protect optic neurons from apoptosis induced by oxidative stress. These results suggest that activating the AMPK protein kinase pathway and increasing mitochondrial damage repair or biosynthesis may be a new method to treat or delay retinal degeneration.
【学位授予单位】：大连医科大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：R779.1

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