晚期糖基化终末产物诱导人肾小管上皮细胞表达结缔组织生长因子和纤维连接蛋白

【作者】 杜晓霞；

【导师】 李学旺；

【作者基本信息】 中国协和医科大学 ， 肾脏内科， 2005， 博士

【摘要】 背景 随着世界范围内糖尿病患者的迅速增加，糖尿病并发症对患者生存质量和死亡率的影响也越来越重要。糖尿病肾病是糖尿病的主要并发症之一，肾脏主要病理表现为肾小球和间质中细胞外基质的积聚。大量证据表明，糖尿病肾病的长期预后与肾小管间质病变关系更为密切。为此，研究糖尿病小管间质病变发生、发展的机制，寻找干预治疗小管间质病变的措施在糖尿病肾病的防治上具有重要意义。近年的研究显示，在糖尿病环境下，高糖中的游离醛基可与体内蛋白、脂类、核苷酸中的游离氨基反应，经过长期的复杂变化，最终生成非酶糖基化终末产物(advanced glycation end products，AGEs)。AGEs的增加和积聚，是引起糖尿病肾小球病变发生和发展的重要因素。AGEs可以直接破坏细胞、基质间的连接和相互作用，直接影响血管壁和基底膜的完整性，影响器官组织的结构和功能。AGEs还通过与与细胞表面特异性受体RAGE(receptor for advanced glycation end products)结合，激活氧化应激、促分裂原活化蛋白激酶(mitogen-activated protein kinase，MAPK)、核转录因子κB(NF-κB)等信号传导途径，诱导多种细胞因子的表达及细胞外基质的积聚，导致肾小球硬化、炎性浸润和蛋白尿产生。目前对于AGEs在糖尿病肾病小管间质病变中的作用机制研究甚少，AGEs与糖尿病肾间质病变之间的潜在联系尚待进一步研究。 目的 本研究通过体外实验，观察AGE-BSA对体外培养的人近端肾小管上皮细胞株HK-2表达结缔组织生长因子(CTGF)和纤维连接蛋白(FN)的影响，并探讨可能的作用途径。 方法 1．免疫细胞化学法鉴定HK-2细胞并检测RAGE的表达； 2．分别以不同浓度的AGE-BSA(0、20、50、100μg／ml)和BSA刺激HK-2更多还原

【Abstract】 BackgroundThe population of diabetic patients is dramatically increasing in the world. The development of the various complications of diabetes contributes to the high morbidity and mortality. The enlargement of the kidney, large proteinuria excretion, hypertension and damage of kidney function is the major characteristics of diabetic nephropathy. It is well known that, the accumulation of extracellular matrix proteins both in the glomerular mesangium and tubulointerstitium is the typical pathological leisions of diabetic nephropathy; and it is believed from recently studied that, the tubulointerstitial injury may be an important predictor of renal dysfunction in diabetes nephropathy. So the research on the mechanisms of the intiation and development of diabetic tubulointerstitial injuries will be benefit for development of an accurate treatment. It is strongly suggested from recent the in vitro and in vivo studies that AGEs and their receptor (the receptor for AGE, RAGE) system take a crucial part in development of diabetic nephropathy. In diabetic patients, glucose can react non-enzymatically with the amino groups of proteins, lipids and nucleic acids. and form irreversible heterogeneous derivatives termed advanced glycation endproducts (AGEs).after undergoing complex reactions. AGEs are known to accumulate in circulating blood and in various tissues at an extremely accelerated rate under the diabetic state. The structural integrity of the vessel wall and underlying basement membranes were directly influenced through excessive crosslinking of matrix molecules. In addition, receptor-dependent mechanisms are likely to work in the AGE-induced tissue dysfunction and the RAGE (the receptor for AGE) is.the bestcharacterized. The glomerulosclerosis, inflammation infiltration and proteinuria may induce by AGE-RAGE interaction. The underlying pathogenic link between AGEs and the development of tubulointerstitial injury has not widely been investigated yet and the nechanism of AGEs mediated tubulointerstitial injury still waiting for elucidation.更多还原