特发性膜性肾病患者肾组织中SOD2的表达及意义

发布时间：2018-06-18 12:33

本文选题：特发性膜性肾病 + 发病机制　；参考：《河北医科大学》2014年硕士论文

【摘要】：目的：膜性肾病（membranous nephropathy, MN）是成年人肾病综合征(nephrotic syndrome, NS)最常见的病理类型之一。据统计，成年人中约75%的病例主要为特发性膜性肾病(idiopathic membranous nephropathy,IMN)，而25%的病例则继发于各种各样的原因，包括肿瘤、感染、自身免疫疾病、代谢性疾病以及药物、毒物损害等。1/4-1/3IMN患者可完全或部分自发缓解，大量蛋白尿的患者,自发缓解率可占到20%左右，其余患者会缓慢进展至终末期肾脏病，或在5-16年后死于并发症及其他疾病。近年来，IMN的发病率呈逐年上升趋势，但其具体发病机制的研究仍不是很透彻，普遍认为是机体针对肾脏足细胞产生特异性IgG4抗体，形成上皮下免疫复合物而致病。因此明确IMN的发病机制有重要意义，将对疾病的诊断和治疗提供新的帮助。锰超氧化物歧化酶（manganese superoxide dismutase,SOD2）是广泛的抗氧化细胞保护系统的重要组成部分，是一种抗氧化金属酶，可将毒性的超氧化物阴离子转化为过氧化氢和双原子氧，在机体氧化与抗氧化平衡中起到至关重要的作用。当机体在遭受各种有害刺激时，体内高活性分子产生过多，氧化系统和抗氧化系统失衡，使机体处于氧化应激（oxidativestress, OS）状态。OS与很多疾病包括肾脏疾病的发生、发展密不可分。OS状态时，SOD2表达增加，这可以降低OS对组织造成的损伤。OS损伤的标志物多种多样，其中8-羟基脱氧鸟苷（8-hydroxy-2'-deoxyguanosine,8-OHdG）是DNA损害的敏感标志物。在疾病或某些外源性物质刺激下活性氧类(Reactive Oxygen Species, ROS)快速释放并在体内过度蓄积，致OS超出机体抗氧化能力而造成DNA的氧化损伤。另有研究发现，IMN患者肾组织中的SOD2可能作为足细胞的特异性抗原，参与IMN的发病过程，促进IMN的进展。因此研究SOD2在IMN患者肾组织中表达是很有必要的。本课题旨在研究SOD2在IMN患者肾组织内表达及意义，及其与IgG4表达部位的联系，并检测患者血、尿标本中8-OHdG的表达水平，探讨OS在IMN发病中的作用，，进一步揭示IMN的发病机制，为指导临床治疗和观察预后提供依据。方法：病例来源于2013年6月至2013年12月河北医科大学第三医院肾内科病房诊治的41例IMN住院患者，所有患者均为首次经肾穿刺活检病理检查确诊者。收集首次经肾穿刺活检病理检查确诊的继发性膜性肾病（Secondary Membranous Nephropathy, SMN）住院患者13例和微小病变性肾病(minimal change disease, MCD)住院患者6例为对照组。应用免疫组织化学方法检测IMN组、SMN组和MCD组患者肾组织中SOD2及IgG4的表达部位，结果通过图像分析系统（Image-ProPlus, IPP）进行半定量分析。同时收集IMN组、SMN组和MCD组患者晨起的血液及尿液标本，应用ELISA定量方法检测血液及尿液标本中8-OHdG的表达水平，并探讨SOD2与8-OHdG表达的相关性。应用SPSS17.0统计学软件对实验数据进行统计学处理， P＜0.05时差异有统计学意义，计量资料用均数±标准差(x±s)表示，计数资料采用率或构成比表示。正态分布资料多组间均数比较采用方差分析，多重比较采用SNK-q检验。相关性检验采用直线相关分析。结果：SOD2在IMN组、SMN组和MCD组患者肾组织肾小管上皮细胞均有表达，表达无明显差异；SOD2在SMN组、MCD组患者肾组织肾小球中未见表达；SOD2在IMN组患者肾组织肾小球基底膜、足细胞和上皮下均有一定表达。IMN组患者肾组织肾小球内SOD2的表达较SMN组、MCD组均显著增强（P0.01）。IgG4在SMN组、MCD组患者肾组织中未见表达；IgG4在大部分IMN组患者肾组织肾小球基底膜及上皮下有表达。IMN组与SMN组、MCD组比较，肾小球内IgG4表达明显增强（P0.01）。IMN患者肾小球内SOD2的表达与24小时尿蛋白定量呈负相关（r=-0.354，P=0.023，P0.05）；IgG4的表达与24小时尿蛋白定量呈正相关（r=0.361，P=0.021，P0.05）。IMN组、SMN组患者血、尿标本中8-OHdG表达水平较MCD组升高（P0.05）；IMN组与SMN组相比差异无统计学意义（P0.05）。结论：①8-OHdG在IMN患者血液及尿液标本中表达水平升高，证实IMN发病过程中存在DNA的氧化损伤，提示OS参与了IMN的发生和发展。②SOD2在IMN肾组织中表达增高，且与24小时尿蛋白定量呈负相关，提示SOD2作为抗氧化金属酶，在肾脏OS时对机体起保护作用，降低尿蛋白的产生。但SOD2与IgG4均在IMN肾小球上皮下沉积，推测SOD2可能作为足细胞致病抗原参与IMN的发病过程。③SOD2在IMN和SMN中表达不同，提示IMN与SMN的发病机制不同。
[Abstract]:Objective: membranous nephropathy (MN) is one of the most common pathological types of adult nephrotic syndrome (nephrotic syndrome (NS)). According to statistics, about 75% of adult cases are mainly idiopathic membranous nephropathy (idiopathic membranous nephropathy, IMN), and 25% of the cases are secondary to a variety of causes, including tumors. .1/4-1/3IMN patients with infection, autoimmune diseases, metabolic diseases, drugs and poison damage can be completely or partially relieved. The spontaneous remission rate of patients with large albuminuria is about 20%, and the rest of the patients will slow to end-stage renal disease or die from complications and other diseases after 5-16 years. In recent years, the incidence of IMN It is increasing year by year, but the research on its specific pathogenesis is still not very thorough. It is generally believed that the body is pathogenic to the specific IgG4 antibody of the renal podocytes and forms the upper subcutaneous immune complex. Therefore, it is of great significance to clarify the pathogenesis of IMN, and will provide new help for the diagnosis and treatment of the disease.
Manganese superoxide dismutase (manganese superoxide dismutase, SOD2) is an important component of a wide range of antioxidant cell protection systems. It is an antioxidant enzyme, which can convert toxic superoxide anion into hydrogen peroxide and diatomic oxygen. It plays a vital role in the oxidation and antioxidant balance of the body. When a variety of harmful stimuli are subjected, the high active molecules in the body produce too much, the oxidation system and the antioxidant system are unbalanced, making the body in the state of oxidative stress (oxidativestress, OS).OS and the occurrence of many diseases including kidney disease. When the development of the inseparable.OS state, the SOD2 table increases, which can reduce the OS damage to the tissue caused by.OS damage. 8- hydroxyl deoxy guanosine (8-hydroxy-2'-deoxyguanosine, 8-OHdG) is a sensitive marker of DNA damage. The reactive oxygen species (Reactive Oxygen Species, ROS) is released rapidly and overaccumulated in the body under the condition of disease or some exogenous substances, causing OS beyond the body's antioxidant capacity to cause oxidative damage to DNA. Other studies have found that SOD2 in the renal tissue of IMN patients may be a specific antigen of the podocyte, participate in the pathogenesis of IMN and promote the progress of IMN. Therefore, it is necessary to study the expression of SOD2 in the renal tissue of the patients with IMN. The purpose of this study is to study the significance of SOD2 in the renal tissue of IMN patients and the relationship with the IgG4 expression site. To detect the expression level of 8-OHdG in the blood and urine samples of patients, to explore the role of OS in the pathogenesis of IMN, to further reveal the pathogenesis of IMN, and to provide the basis for guiding clinical treatment and observing the prognosis.
Methods: the cases were derived from 41 IMN hospitalized patients in the nephrology ward of the Third Hospital of Hebei Medical University from June 2013 to December 2013. All patients were confirmed by the first biopsy of the renal biopsy. The first secondary membranous nephropathy (Secondary Membranous Nephropathy, SMN) was collected for the first time by biopsy of the renal biopsy (SMN). 13 hospitalized patients and 6 patients with minimal change disease (MCD) were in the control group. The immunohistochemical method was used to detect the expression of SOD2 and IgG4 in group IMN, SMN and MCD groups, and the results were semi quantitative analyzed by the image analysis system (Image-ProPlus, IPP). Meanwhile, the IMN group was collected. The blood and urine samples from group MCD and group MCD were measured by ELISA quantitative method, and the correlation between the expression of SOD2 and 8-OHdG was investigated. The data of the experimental data were statistically processed with SPSS17.0 statistics software. The difference was statistically significant when P < 0.05, and the mean number of measurement data was standardized. The difference (x + s) was expressed as a representation of the ratio or composition of the count data. The average number of normal distribution data was compared with the analysis of variance, and the multiple comparison used the SNK-q test. The correlation test was based on the linear correlation analysis.
Results: SOD2 was expressed in renal tubular epithelial cells in group IMN, SMN and MCD, and there was no obvious difference in the expression of renal tubular epithelial cells. In group SMN, there was no expression of renal glomerulus in group MCD; SOD2 in the renal tissue of group IMN, renal glomerular basement membrane, podocyte and epithelia, there was certain expression of renal glomerular SOD2 in the patients with group.IMN. The expression of MCD in group SMN was significantly enhanced (P0.01).IgG4 in group SMN, group MCD was not expressed in renal tissue, IgG4 was expressed in renal glomerular basement membrane and subcutaneous tissue in most of IMN patients, and.IMN group and SMN group were expressed in the renal glomerular basement membrane and MCD group. The expression of protein was negatively correlated (r=-0.354, P=0.023, P0.05), and the expression of IgG4 was positively correlated with the 24 hour urinary protein (r=0.361, P=0.021, P0.05).IMN group. The expression level of 8-OHdG in the SMN group was higher than that in the MCD group (P0.05).
Conclusion: (1) the expression level of 8-OHdG in the blood and urine specimens of patients with IMN is elevated, which confirms the oxidative damage of DNA during the pathogenesis of IMN, suggesting that OS participates in the occurrence and development of IMN. (2) the expression of SOD2 in the renal tissue of IMN is higher and is negatively related to the quantitative 24 hour urine protein, suggesting that SOD2 is used as an antioxidant enzyme and in the kidney OS of the body. It plays a protective role to reduce the production of urine protein. But both SOD2 and IgG4 are deposited subcutaneously on IMN glomeruli. It is suggested that SOD2 may participate in the pathogenesis of IMN as a pathogenetic antigen of podoni. (3) the expression of SOD2 in IMN and SMN is different, suggesting that the pathogenesis of IMN and SMN is different.
【学位授予单位】：河北医科大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R692

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