视网膜损伤中炎症发生的机制研究

发布时间：2018-05-05 08:29

  本文选题：糖尿病视网膜病变 + 缺血再灌注损伤　； 参考：《武汉大学》2013年博士论文

【摘要】：视网膜病变是一类危害人类生活质量的较普遍的疾病。视网膜缺血再灌注损伤在糖尿病视网膜病变、青光眼等多种视网膜病变中均有发生。视网膜缺血再灌注会导致视网膜神经退化、血管退化和胶质细胞激活等病理现象,但是其分子机制目前尚未完全清楚,并且还缺乏有效的治疗药物。 炎症反应是缺血再灌注导致视网膜损伤的重要机制之一。同时,慢性炎症反应对糖尿病视网膜病变的发生发展具有促进作用。组蛋白修饰能够调节基因表达。因此猜想炎症因子在病变视网膜中的过量和持续表达可能与组蛋白修饰相关。 本论文采用三种实验模型,包括高眼压诱导的视网膜缺血再灌注模型、STZ(链脲佐菌素)诱导的糖尿病模型和高糖刺激的米勒胶质细胞模型来研究视网膜损伤的炎症发生机制。主要通过PASH和免疫染色等方法检测视网膜病理变化,应用蛋白质印迹、聚合酶链式反应和染色质免疫共沉淀等技术研究炎症反应、组蛋白修饰及组蛋白异构体在视网膜损伤以及体外细胞模型中的变化。姜黄素和米林霉素两种药物都具有抗炎作用,本论文采用这两种药物对视网膜损伤的动物模型和细胞模型进行预防和干预治疗,研究这些药物的作用靶标以及组蛋白修饰和炎症反应在视网膜损伤中的相互联系。 本论文发现,在损伤前口服0.01%、0.05%或者0.25%的姜黄素能够显著的抑制视网膜缺血再灌注损伤引起的神经节细胞层的细胞缺失；损伤前或者损伤后口服0.05%的姜黄素都能够抑制损伤引起的血管退化；损伤前口服0.05%的姜黄素抑制了缺血再灌注损伤引起的视网膜神经节细胞层的细胞凋亡、β-tubulin Ⅲ下调、NF-κB和STAT3(?)言号通路激活以及炎症因子MCP-1表达量上调,但是对损伤引起的米勒细胞激活和ERK信号通路激活没有显著作用。因此,姜黄素对缺血再灌注损伤导致的视网膜神经和血管退化的保护作用是通过抑制炎症信号通路的激活以及减少炎症因子的过量表达实现的。 本论文还发现早期病史的糖尿病大鼠视网膜内组蛋白的乙酰化修饰水平显著升高,并伴随组蛋白乙酰化酶表达量上调和组蛋白2类去乙酰化酶表达量下调。并且证明糖尿病大鼠视网膜内高水平的组蛋白H3K9和H3K18乙酰化部分定位在米勒细胞上。在体外高糖培养的米勒细胞系rMC-1中也发现组蛋白乙酰化升高的现象,同时GFAP、p-STAT3(Tyr)和NF-KB-p65的蛋白水平以及炎症因子TNFα和MCP-1的mRNA水平也显著上调。另外还发现米林霉素通过抑制高糖导致的GFAP、TNFα和MCP-1启动子上组蛋白H3K18的乙酰化水平,抑制了这三个基因的转录。这些结果表明高糖导致米勒细胞中炎症因子启动子上的组蛋白乙酰化水平升高,因而使米勒细胞产生炎症反应；同时米林霉素对糖尿病视网膜病变的保护作用也来源于对组蛋白乙酰化水平的抑制。
[Abstract]:Retinopathy is a common disease that endangers the quality of human life. Retinal ischemia reperfusion injury occurs in many kinds of retinopathy such as diabetic retinopathy, glaucoma and so on. Retinal ischemia-reperfusion can lead to retinal nerve degeneration, vascular degeneration and glial cell activation, but the molecular mechanism of retinal ischemia reperfusion is not fully understood, and there is a lack of effective treatment drugs. Inflammation is one of the important mechanisms of retinal injury induced by ischemia reperfusion. At the same time, chronic inflammatory reaction can promote the development of diabetic retinopathy. Histone modification can regulate gene expression. It is assumed that excessive and persistent expression of inflammatory factors in the pathological retina may be related to histone modification. In this paper, three experimental models were used to study the inflammatory mechanism of retinal injury, including the diabetic model induced by high intraocular pressure (IOP) induced retinal ischemia and reperfusion (STZ) and the Hans Muller glial cell model stimulated by high glucose. The pathological changes of retina were detected by PASH and immunostaining. The inflammatory reaction was studied by Western blotting, polymerase chain reaction and chromatin immunoprecipitation. Histone modification and histone isomer changes in retinal injury and in vitro cell model. Curcumin and milinomycin both have anti-inflammatory effects. In this paper, the two drugs were used to prevent and intervene the animal model and cell model of retinal injury. To study the effects of these drugs and the correlation between histone modification and inflammation in retinal injury. In this study, we found that oral administration of 0.05% or 0.25% curcumin before injury could significantly inhibit the loss of neurons in the ganglion cell layer induced by retinal ischemia-reperfusion injury. Before and after injury, 0.05% of curcumin could inhibit the vascular degeneration induced by injury, and before injury, 0.05% of curcumin inhibited the apoptosis of retinal ganglion cell layer induced by ischemia-reperfusion injury, and 尾 -tubulin 鈪，

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