RAGE基因表达与糖尿病血管病变

晚期糖基化终末产物(AGEs)受体(RAGE)与其配体AGEs形成的AGEs—RAGE系统在糖尿病血管病变的发生、发展过程中起着重要作用。年龄及AGEs等多种因素均能调节RAGE基因的表达。糖尿病患者体内RAGE高表达加速了病人血管病变的发展过程，增加了病变的复杂性。阻断RAGE通路可缓解糖尿病血管病变。因此，RAGE可以作为治疗糖尿病血管病变的药物靶点，并为临床医师治疗糖尿病血管病变提供新思路。     

专家专题报告9:AGE-RAGE相互作用导致胰岛β细胞功能障碍和凋亡的机制研究

高级糖基化终末产物(AGEs)及其受体(Receptor of AGEs,RAGE)在糖尿病并发症的发生发展过程中扮演着重要的角色,如糖尿病视网膜病变、糖尿病神经病变和糖尿病肾病等.     

RAGE基因表达与糖尿病血管病变

晚期糖基化终末产物(AGEs)受体(RAGE)与其配体AGEs形成的AGEsRAGE系统在糖尿病血管病变的发生、发展过程中起着重要作用。年龄及AGEs等多种因素均能调节RAGE基因的表达。糖尿病患者体内RAGE高表达加速了病人血管病变的发展过程,增加了病变的复杂性。阻断RAGE通路可缓解糖尿病血管病变。因此,RAGE可以作为治疗糖尿病血管病变的药物靶点,并为临床医师治疗糖尿病血管病变提供新思路。     

糖基化终产物及其受体在糖尿病血管并发症中的作用

高血糖记忆现象可能与糖尿病患者体内高水平的糖基化终产物（AGEs）有关,现就AGEs及其晚期糖基化终末产物受体（RAGE）在糖尿病血管并发症中的作用综述如下。     

晚期糖基化终产物在糖尿病血管并发症中的作用机制

晚期糖基化终产物（AGEs）是蛋白质或脂质经过糖基化反应的产物。AGEs存在于糖尿病患者的血管中,促进动脉粥样硬化的发展。多种不同的细胞上AGEs的存在和聚集影响着细胞内外的结构和功能。AGEs通过与细胞外基质基底膜上的分子形成交联和与其受体（RAGE）结合引起多种微血管和大血管并发症。RAGE被AGEs激活后导致转录因子NF-κB和它的靶因子的表达。AGEs可诱发糜蛋白酶的表达和糜蛋白酶依赖性血管紧张素Ⅱ的生成,从而作用于糖尿病血管并发症的发展。     

晚期糖基化终末产物及其受体在原发性高血压中的作用机制

近年来研究发现晚期糖基化终末产物（advanced glycation end products,AGEs）在原发性高血压的发生、发展过程中起着一定的病理作用,AGEs主要通过直接修饰蛋白、结合受体RAGE并激活信号转导通路两条作用途径来发挥效应。此外AGEs—RAGE还与肾素-血管紧张素系统、氧化应激三者构成正反馈环路,共同参与了原发性高血压的进程。相信随着对AGEs—RAGE作剧机制及药物干预的进一步研究,抗AGEs的治疗策略将有望成为防治高血压及其并发症的新方向。     

辛伐他汀抑制糖基化终产物诱导心肌微血管内皮细胞炎性反应及机制探讨

目的观察羟甲基戊二酰辅酶A还原酶抑制荆辛伐他汀对糖基化终产物(AGEs)诱导心肌微血管内皮细胞(CMECs)表达单核细胞趋化因子1(MCP-1)、细胞间黏附分子1(ICAM-1)的抑制作用,探讨辛伐他汀在早期糖尿病心肌微血管炎性病变中的保护机制。方法将培养的CMECs用辛伐他汀预孵育6 h,加入400mg/L的外源性糖基化牛血清白蛋白共培养72 h,分为AGEs组和BSA对照组,分别采用ELISA法测定McP-1的表达;流式细胞仪测定ICAM-1的表达;RT-PCR法测定糖基化终产物特异性受体mRNA的表达;Western blot法检测内皮细胞表面特异性受体(RAGE)蛋白表达。结果与BSA对照组比较,AGEs组MCP-1、ICAM-1、RAGE mRNA及其蛋白表达明显增强,差异有统计学意义(P<0.05)。辛伐他汀预孵则显著抑制AGEs诱导的MCP-1、ICAM-1的表达,并在mRNA及蛋白水平下调RAGE蛋白的表达。结论辛伐他汀可能通过抑制AGEs-RAGE信号途径来发挥对糖尿病心肌微血管病变的保护作用。     

普罗布考对大鼠心脏微血管内皮细胞RAGE表达的影响

目的 观察普罗布考对大鼠心脏微血管内皮细胞糖基化终末产物（AGEs）受体（RAGE）表达的影响.方法 体外原代培养心脏微血管内皮细胞.空白组加无血清培养液培养,AGEs组加AGEs（100 mg/L）孵育,普罗布考（5、10 μmol/L）组用普罗布考（5、10 μmol/L）分别作用细胞30 min后,加入AGEs（100 mg/L）再孵育24 h.各组分别作用于心脏微血管内皮细胞24h,免疫组化法和Western blot法检测RAGE蛋白表达.结果 AGEs组与空白组RAGE蛋白表达比较,P＜0.05;普罗布考10μmol/L组与AGEs组比较,P＜0.05.结论 普罗布考能够抑制AGEs诱发的心脏微血管内皮细胞RAGE的表达,从而抑制氧化应激的发生.     

AGE-RAGE系统在糖尿病视网膜病变中的作用

糖尿病视网膜病变(DR)的发病机制至今尚未完全阐明。晚期糖基化终末产物(AGEs)的形成参与糖尿病视网膜病变的发生、发展,它们能与AGEs受体(RAGE)相互作用,并通过一系列分子机制导致视网膜周细胞缺失,诱发炎性反应以及新生血管的形成。因此,抑制AGEs形成或阻断AGEs与其受体相互作用可能延缓糖尿病视网膜病变的发生、发展。本文就AGEs形成、AGE-RAGE系统在DR中的作用和DR的药物治疗等作一综述。     

RAGE及其配体的临床意义研究进展

晚期糖基化终末产物(AGEs)受体(RAGE)是一种具有重要功能的多配体受体,其配体包括AGEs、两性素/高速泳动族盒1蛋白、S100/钙粒蛋白及β淀粉样肽等。RAGE属于单穿膜片段受体,为免疫球蛋白超家族的成员。有些RAGE缺少穿膜域,可由细胞分泌出来,成为可溶性RAGE(sRAGE)。位于细胞膜上的RAGE与相应的配体结合后可启动若干信号通路,其中以核因子-κB最为重要。RAGE不仅参与糖尿病慢性并发症的发生、发展,还与炎症反应、肿瘤的侵袭和转移、神经再生、Alzheimer病有关。用sRAGE或RAGE抗体可阻断RAGE的效应,具有潜在的治疗意义。     

Advanced glycation end products and their receptors co-localise in rat organs susceptible to diabetic microvascular injury

Summary Advanced glycation end products (AGEs) are believed to play an important role in the development of diabetic complications. AGEs are increased in experimental diabetes and treatment with the inhibitor of advanced glycation end products, aminoguanidine, has been shown to attenuate the level of these products in tissues undergoing complications. Recently, an AGE-binding protein has been isolated from bovine lung endothelial cells and termed the receptor for advanced glycated end products (RAGE). The present study sought to determine the distribution of AGE and RAGE in tissues susceptible to the long-term complications of diabetes including the kidney, eye, nerve, arteries as well as in a tissue resistant to such complications, the lung. Using polyclonal antisera both AGE and RAGE were found to co-localize in the renal glomerulus. AGE staining was clearly increased with age and was further increased by diabetes. Aminoguanidine treatment reduced AGE accumulation in the kidney. Co-localisation of AGE and RAGE was demonstrated in the inner plexiform layer and the inner limiting membrane of the retina and in nerve bundles from mesenteric arteries. In the aorta, both AGE and RAGE were found in the intima, media and adventitia. Medial staining was increased in diabetes and was reduced by aminoguanidine treatment. A similar pattern was observed for RAGE in the aorta. In the lung, RAGE was found widely distributed throughout the lung whereas the distribution of AGE staining was more limited, primarily localising to macrophages. The co-localisation of AGEs and RAGE in sites of diabetic microvascular injury suggests that this ligand-receptor interaction may represent an important mechanism in the genesis of diabetic complications. [Diabetologia (1997) 40: 619–628] Received: 16 October 1996 and in final revised form: 17 February 1997     

Receptor for Advanced Glycation End Products (RAGE) in Type 1 Diabetes Pathogenesis

The receptor for advanced glycation end products (RAGE) is a novel protein increasingly studied in the pathogenesis of type 1 diabetes (T1D). RAGE is expressed by several immune cell types, including T cells, antigen-presenting cells, endothelial cells, and the endocrine cells of the pancreatic islets. RAGE binds various ligands including advanced glycation end products (AGEs), high-mobility group box protein 1 (HMGB1), S100 proteins, β-amyloid, β-sheet fibrils, and lipopolysaccharide. AGEs are a particularly interesting ligand because their exogenous introduction into the body can be accelerated by the consumption of AGE-rich processed foods. This review will detail RAGE isoforms and its ligands and discuss how RAGE binding on the aforementioned cells could be linked to T1D pathogenesis.     

Up-Regulated Expression of Advanced Glycation End-Products and Their Receptor in the Small Intestine and Colon of Diabetic Rats

Background and Aims  

Gastrointestinal disorders and symptoms are common in diabetic patients. Advanced glycation end-products (AGEs) and their receptor (RAGE) have been proposed as an important pathological mechanism underlying diabetic complications, such as diabetic cardiopathy, retinopathy, nephropathy, etc. The aims were to study the distribution of AGE and RAGE in the normal and diabetic small intestine and colon in rats and the possible relationship between AGEs/RAGE and diabetes-induced intestinal structural remodeling.     

Advanced glycation endproducts--role in pathology of diabetic complications

Diabetes mellitus is a common endocrine disorder characterised by hyperglycaemia and predisposes to chronic complications affecting the eyes, blood vessels, nerves and kidneys. Hyperglycaemia has an important role in the pathogenesis of diabetic complications by increasing protein glycation and the gradual build-up of advanced glycation endproducts (AGEs) in body tissues. These AGE form on intra- and extracellular proteins, lipids, nucleic acids and possess complex structures that generate protein fluorescence and cross-linking. Protein glycation and AGE are accompanied by increased free radical activity that contributes towards the biomolecular damage in diabetes. There is considerable interest in receptors for AGEs (RAGE) found on many cell types, particularly those affected in diabetes. Recent studies suggest that interaction of AGEs with RAGE alter intracellular signalling, gene expression, release of pro-inflammatory molecules and free radicals that contribute towards the pathology of diabetic complications. This review introduces the chemistry of glycation and AGEs and examines the mechanisms by which they mediate their toxicity. The role of AGEs in the pathogenesis of retinopathy, cataract, atherosclerosis, neuropathy, nephropathy, diabetic embryopathy and impaired wound healing are considered. There is considerable interest in anti-glycation compounds because of their therapeutic potential. The mechanisms and sites of action of selected inhibitors, together with their potential in preventing diabetic complications are discussed.     

Age associated changes of AGE-receptor expression: RAGE upregulation is associated with human heart dysfunction

The binding of advanced glycation endproducts (AGEs) to their receptors is known to cause changes in cell function during normal ageing and is implicated in the pathogenesis of cardiovascular disease. In this study, expression of the AGE-receptor 3 (AGE-R3) and the receptor for AGEs (RAGE) was compared on the mRNA and protein level in the ageing human heart. Western blot and RT-PCR analysis of the AGE receptors from the cardiac auricles in senescent and adult patients was performed and compared with young controls. Whereas the expressions of AGE-R3 as well as RAGE protein were significantly upregulated in the senescent population, only the upregulation of RAGE is associated with reduced heart function. Therefore, our results support a pathophysiological function for RAGE in the ageing human heart.     

Protein glycation: a firm link to endothelial cell dysfunction

The advanced glycation end products (AGEs) are a heterogeneous class of molecules, including the following main subgroups: bis(lysyl)imidazolium cross-links, hydroimidazolones, 3-deoxyglucosone derivatives, and monolysyl adducts. AGEs are increased in diabetes, renal failure, and aging. Microvascular lesions correlate with the accumulation of AGEs, as demonstrated in diabetic retinopathy or renal glomerulosclerosis. On endothelial cells, ligation of receptor for AGE (RAGE) by AGEs induces the expression of cell adhesion molecules, tissue factor, cytokines such as interleukin-6, and monocyte chemoattractant protein-1. A chief means by which AGEs via RAGE exert their effects is by generation of reactive oxygen species, at least in part via stimulation of NADPH oxidase. Diabetes-associated vascular dysfunction in vivo can be prevented by blockade of RAGE. Thus, agents that limit AGE formation, increase the catabolism of these species, or antagonize their binding to RAGE may provide new targets for vascular protection in diabetes.