人参皂苷Rb1对小鼠肠缺血再灌注致急性肾损伤保护作用中的分子机制研究

发布时间：2018-06-16 12:09

  本文选题：NF-E2-related + factor-2　； 参考：《武汉大学》2014年博士论文

【摘要】：背景： 肠缺血再灌注(Intestinal Ischemia Reperfusion, IIR)损伤是一种临床创伤及休克时最为常见的病理生理机制。肠道因其特殊的细菌环境、特殊的结构和代谢特点以及重要的屏障功能,亦是导致休克、创伤后重要脏器包括肺脏、肾脏和肝脏等远隔脏器损伤的“枢纽”,仍然是相关学科研究的热点问题。新近研究表明,Nrf2是一种调控细胞关键转录因子,其可以有效诱导细胞对抗氧化应激损伤,是机体重要的内源性保护机制,但其在肠缺血再灌注致肾损伤中的作用及机制尚待探讨。传统中药人参的主要成分——人参皂苷Rbl由于具备“多靶效应”的独特优势,特别是其抗氧化作用是减轻多脏器缺血再灌注损伤的重要机制。然而,目前极少关于人参皂苷Rbl对肠缺血再灌注致继发性远隔脏器损伤保护作用具体机制的研究。因此,Nrf2/ARE信号通路作为机体重要的内源性保护机制,对于其在肠缺血再灌注引起的远隔脏器损伤中的保护作用及机制亟待研究。 目的： 研究人参皂苷Rb1对肠缺血再灌注致小鼠急性肾损伤的影响,研究其对肾脏组织Nrf2表达的影响及保护机制。 方法： 1、随机将成年雄性C57BL/6J小鼠分为5组：①假手术组(sham组)；②肠缺血再灌注组(IIR组)；③生理盐水组(NS组)；④低剂量组(RB1-30组)；⑤高剂量组(RB1-60组)。采用夹闭肠系膜上动脉法建立小鼠肠缺血再灌注模型,在光学显微镜下分别观察小肠组织及肾脏组织的形态病理学改变,测定血清中DAO、BUN和Scr水平的变化,以及肾脏组织中MDA含量和SOD活性的改变。 2、随机将成年雄性C57BL/6J小鼠分为6组：①假手术组(sham组)；②肠缺血再灌注+生理盐水组(IIR组)；③肠缺血再灌注+人参皂苷Rbl组(RB1组)；④假手术+ATRA组(sham+ATRA组)；⑤肠缺血再灌注+生理盐水+ATRA组(IIR+ATRA组)；⑥肠缺血再灌注+人参皂苷Rbl+ATRA组(RB1+ATRA组)。在光学显微镜下观察肾脏组织的形态病理学改变,测定血清中BUN、Scr和NGAL水平的变化,和肾脏组织中MDA含量和SOD活性的改变,以及TUNEL细胞凋亡检测和Bcl-2/Bax蛋白表达比值,免疫组化及Western blot检测肾脏组织中Nrf2和HO-1蛋白含量的变化。 结果： 1、IIR组与NS组较sham组中的小肠和肾脏损伤程度显著加剧,病理学评分明显增高(P0.01)；血清DAO、BUN、Scr和肾脏组织MDA含量较sham组明显升高(P0.01)；肾脏组织SOD活性较sham组明显降低(P0.01)；IIR组与NS组各组数据之间均无统计学差异(P0.05)；与IIR组和NS组比较,RB1-30组和RB1-60组中肾脏损伤程度明显减轻(P0.01),血清DAO、BUN和SCr水平、肾脏组织MDA含量明显降低而SOD活性明显升高(P0.01)。 2、RB1组中肾脏损伤程度较IIR组显著降低(P0.01),血清BUN、Scr和NGAL、肾脏组织MDA含量较IIR组明显降低(P0.01)；肾脏组织SOD活性较IIR组明显升高(P0.01)；IIRN肾脏TUNEL凋亡细胞和Bcl-2/Bax蛋白表达比值较sham组明显增加(P0.01)；RB1组肾脏TUNEL凋亡细胞和Bcl-2/Bax蛋白表达比值较IIR组明显降低(P0.01)。IIR组中HO-1、Nrf2含量较sham组显著增高(P0.01)；RB1组中HO-1、Nrf2含量较IIR组进一步增高(P0.01)。sham+ATRA组与sham组、IIR+ATRA组与IIR组中各指标均无统计学差异(P0.05)。而RB1+ATRA组较RB1组肾脏组织损伤程度显著增高(P0.01)；肾脏组织MDA含量明显升高(P0.01)；SOD活性明显降低(P0.01)；肾脏TUNEL凋亡细胞和Bcl-2/Bax蛋白表达比值明显升高(P0.01)；核内Nrf2蛋白含量虽无显著性差异(P0.05),但胞浆HO-1蛋白含量明显减少(P0.01)。 结论： 小鼠肠缺血再灌注可导致急性肾脏损伤,人参皂苷Rbl后处理有效减轻肠缺血再灌注所致的肾脏细胞凋亡以及损伤程度,其机制可能与激活Nrf2/ARE信号通路及其下游信号分子相关。
[Abstract]:Background:
Intestinal Ischemia Reperfusion (IIR) injury is the most common pathophysiological mechanism of clinical trauma and shock. The intestinal tract, due to its special bacterial environment, special structural and metabolic characteristics, and important barrier function, is also a shock, and the important organs including the lungs, kidneys and liver after trauma. The "hub" of organ damage is still a hot issue in related subjects. Recent studies have shown that Nrf2 is a key factor in regulating cell key transcription factors, which can effectively induce cell resistance to oxidative stress damage and is an important endogenous protective mechanism in the body. However, the role and mechanism of it in the injury of kidney after intestinal ischemia-reperfusion still remain to be discussed. The main component of the traditional Chinese medicine ginseng, ginsenoside Rbl, has the unique advantage of "multi target effect", especially its antioxidant effect is an important mechanism to reduce the injury of multiple organ ischemia-reperfusion. However, few of the specific mechanisms of ginsenoside Rbl on the protective effect of intestinal ischemia-reperfusion on the protection of the secondary viscera injury by intestinal ischemia reperfusion Therefore, as an important endogenous protective mechanism of the body, the protective effect and mechanism of Nrf2/ARE signal pathway on the injury of distant viscera caused by intestinal ischemia-reperfusion need to be studied.
Objective:
Objective to study the effects of ginsenoside Rb1 on acute kidney injury induced by intestinal ischemia-reperfusion in mice, and to study the effect of Ginsenoside on Nrf2 expression in renal tissue and its protective mechanism.
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本文编号：2026609