HIF-1α和miR-21在缺血后处理抗肠再灌注损伤中的作用与机制

发布时间：2018-02-03 12:54

本文关键词： 肠缺血/再灌注损伤低氧诱导因子-1α 微小核糖核酸-21　出处：《南京医科大学》2017年博士论文　论文类型：学位论文

【摘要】：研究背景:肠缺血/再灌注(Ischemia/Reperfusion,I/R)损伤可导致肠组织损伤,即肠I/R损伤,缺血后处理是指组织器官在较长时间缺血后,在再灌注一开始即进行3个循环的再灌注/停灌注处理,即30秒再灌注/30秒再阻断,虽然已经证实缺血后处理可以减轻肠I/R损伤的程度,但是缺血后处理抗肠I/R损伤的机制尚不明确。目的:研究低氧诱导因子-1α(HIF-1α)和微小核糖核酸-21(miR-21)在缺血后处理抗肠I/R损伤中的作用和机制,揭示缺血后处理抗肠I/R损伤的发生机制,从而为临床治疗肠I/R损伤提供理论依据。资料和方法:本研究首先通过IEC-6细胞进行系列体外实验研究,主要步骤和内容包括:1.IEC-6细胞的体外培养;2.缺氧环境模拟缺血、缺氧,缺氧/复氧模拟I/R;3.不同条件下观察HIF1-α和miR-21的表达水平;然后通过大鼠肠I/R损伤模型进行系列的体内实验研究,主要步骤和内容包括:1.动物模型制备;2.给予相关干预措施,并制备标本;3.对相关观察指标进行检测。结果:通过大鼠肠I/R损伤的动物模型,研究发现:缺血后处理诱导HIF-1α和miR-21的表达水平显著升高,降低肠I/R损伤评分,并降低肠上皮细胞凋亡指数。阻断HIF-1α后,miR-21的表达水平下降,并且缺血后处理抗肠I/R损伤的作用消失,证实miR-21的表达是由HIF1-α调控的,且HIF-Iα和miR-21参与了缺血后处理抗肠I/R损伤的作用。肠上皮细胞IEC-6研究证实:缺氧可诱导miR-21的表达水平显著升高,但在阻断HIF1-α后,缺氧诱导miR-21的表达水平升高的作用消失,证实miR-21的表达是由HIF1-α调控的;同时,阻断miR-21或HIF1-α后,miR-21调控程序性细胞死亡4(PDCD4)和Fas-L的作用消失,进而导致缺血后处理抗肠I/R损伤的作用消失。结论:缺血后处理通过作用于HIF1-α进而调控miR-21的表达,miR-21可以通过调控PDCD4和Fas-L进而调控细胞的凋亡。缺血后处理通过调控HIF1-α和miR-21而减轻肠I/R损伤的程度。
[Abstract]:Background: Ischemia / reperfusion Ischemia / reperfusion I / R injury may lead to intestinal tissue damage, I. E. intestinal I / R damage. Post-ischemic treatment refers to the tissue and organs after a long period of ischemia, at the beginning of reperfusion three circulatory reperfusion / reperfusion treatment, that is, 30 seconds reperfusion / 30 seconds reperfusion block. Although it has been shown that ischemic post-treatment can reduce the extent of intestinal I / R damage. But the mechanism of intestinal I / R injury after ischemic treatment is not clear. Objective: to study hypoxia inducible factor-1 伪 (HIF-1 伪) and microRNA (-21miR-21). The role and mechanism of intestinal I / R injury after ischemic treatment. To reveal the mechanism of intestinal I / R injury induced by ischemic postconditioning. In order to provide a theoretical basis for the clinical treatment of intestinal I / R injury. Materials and methods: this study first carried out a series of in vitro experiments through IEC-6 cells. The main steps and contents include: 1. In vitro culture of IEC-6 cells; 2. Anoxic environment to simulate ischemia, hypoxia, hypoxia / reoxygenation to simulate I / R; 3. The expression levels of HIF1- 伪 and miR-21 were observed under different conditions. Then a series of in vivo experiments were carried out on the rat intestinal I / R injury model. The main steps and contents included: 1. 2. Relevant intervention measures were given, and specimens were prepared. 3.Results: through the animal model of intestinal I / R injury, we found that the expression levels of HIF-1 伪 and miR-21 were significantly increased after ischemic treatment. After blocking HIF-1 伪, the expression of miR-21 decreased, and the effect of ischemic treatment on intestinal I / R injury disappeared. It is confirmed that the expression of miR-21 is regulated by HIF1- 伪. HIF-I 伪 and miR-21 were involved in the protective effect on intestinal I / R injury after ischemia. IEC-6 studies of intestinal epithelial cells confirmed that hypoxia could induce a significant increase in the expression of miR-21. However, after blocking HIF1- 伪, the effect of hypoxia induced increased expression of miR-21 disappeared, which confirmed that the expression of HIF1- 伪 was regulated by HIF1- 伪. At the same time, after blocking miR-21 or HIF1- 伪, the effects of miR-21 on programmed cell death (4pPDCD4) and Fas-L disappeared. Conclusion: the expression of miR-21 is regulated by the action of HIF1- 伪 in the ischemic post-treatment. [WT5HZ] [WT5 "HZ] [WT5" BZ] [WT5 "BZ] [WT5BZ]. MiR-21 can regulate apoptosis by regulating PDCD4 and Fas-L, and post-ischemic treatment can reduce the degree of intestinal I / R damage by regulating HIF1- 伪 and miR-21.
【学位授予单位】：南京医科大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：R574

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