糖基化终末产物及其受体在胃肠道中的分布

目的:研究糖基化终末产物(advanced glycation end products,AGE)及其受体(receptor for advanced glycation end products,RAGE)在胃肠道中的分布,为进一步探索其在慢性糖尿病胃肠功能紊乱中的作用奠定基础.方法:分别对成年Wistar大鼠食管、胃、十二指肠、空肠、回肠、结肠及直肠组织进行AGE及RAGE免疫组织化学染色.结果:(1)食管:AGE及RAGE主要分布在横纹肌的肌细胞及黏膜的鳞状上皮细胞;(2)胃:AGE在壁细胞为强阳性.RAGE在主细胞、肥大细胞、神经细胞为强阳性,在壁细胞为中等强度阳性,在表面黏液细胞为弱阳性;(3)小肠:AGE及RAGE在绒毛及固有层上皮细胞为阳性或强阳性.RAGE在肠道的神经细胞亦为强阳性;(4)结肠及直肠:AGE及RAGE在黏膜上皮细胞为弱阳性,RAGE在神经细胞为强阳性.结论:AGE及RAGE广泛分布于肠道上皮细胞及食管的横纹肌细胞,AGE亦分布于胃的壁细胞,RAGE亦分布于胃的壁细胞、主细胞、表面黏液细胞、肥大细胞及胃肠道的神经细胞.     

晚期糖化终产物受体在树突状细胞及T淋巴细胞免疫中的作用

越来越多研究显示晚期糖化终产物受体（RAGE）与其配体反应在炎症及免疫反应中起重要作用。RAGE作为一种模式识别受体表达于树突状细胞、淋巴细胞、单核巨噬细胞和内皮细胞等多种细胞表面,介导非特异性和特异性免疫应答,参与多种炎症免疫性疾病的发生和发展。本文就RAGE对树突状细胞和淋巴细胞成熟及其功能的影响,探讨RAGE在特异性免疫过程中的作用。     

糖基化终产物受体的活化

糖基化终产物受体（RAGE）属于细胞表面分子免疫球蛋白超家族成员,广泛存在于体内多种细胞表面．作为一种细胞信号转导受体与糖基化终产物（AGE）、β-淀粉样肽、双性素等多种配体相互作用,参与糖尿病并发症、阿尔茨海默病、炎症及肿瘤等病理过程。应用抗RAGE抗体或sRAGE阻断RAGE的活化可能为防治上述疾病提供新的靶点。     

晚期糖化终产物对β-淀粉样蛋白诱导PC12细胞凋亡作用机制的实验研究

目的 研究AGEs对Aβ诱导的PC12细胞的作用机制是否与氧化应激有关，阻断RAGE活性能否作为有效的作用靶点。方法 Aβ诱导PC12细胞后加入低、中、高浓度AGEs孵育12h；胰蛋白酶处理PC12细胞后加入Aβ，MTT法检测细胞活力，流式细胞仪测定细胞凋亡，RT-PER法测定RAGE，NF-κB表达。结果 MTT法显示随AGEs浓度升高，细胞活力下降，胰蛋白酶处理组细胞活力升高，流式细胞仪检测显示随AGEs浓度增加，细胞凋亡率增加，RT-PCR法半定量分析RAGE、NF-κB达随AGEs浓度升高而增高。结论 AGEs对Aβ诱导的PC12细胞神经毒性损害由RAGE介导．并与RAGE引起NF-κB达有关，阻断RAGE可减低其神经毒性，阻断RAGE活性可作为有效的药物作用靶点。     

糖基化终末产物对ECV-304细胞ICAM-1及VCAM-1表达的影响

目的探讨糖基化终产物(AGEs)与其受体(RAGE)对ECV-304细胞上血管细胞黏附分子-(1ICAM-1)和细胞间黏附分子-(1VCAM-1)的影响,为研究AGEs在动脉粥样硬化发生发展中的作用提供实验依据。方法采用体外制备的糖基化终产物——糖基化的牛血清白蛋白(AGE-BSA)和反义RAGE寡核苷酸处理ECV-304细胞,通过流式细胞仪技术、Western印迹技术检测ECV-304细胞上ICAM-1、VCAM-1蛋白质的表达。结果AGEs处理ECV-304细胞后,可诱导ECV-304细胞上VCAM-1和ICAM-1的表达增加,且这种效应呈剂量依赖性。采用反义技术阻断RAGE的mRNA水平的翻译后,ECV-304细胞ICAM-1和VCAM-1的表达呈剂量依赖性降低。结论AGEs可通过与其膜受体RAGE的结合激活血管内皮细胞VCAM-1和ICAM-1的表达,这可能是AGEs促动脉粥样硬化发生发展的机制之一。     

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。     

RAGE、P-P38在非小细胞肺癌中的表达及相关性研究

目的检测晚期糖基化终末产物受体(Receptor for Advanced Glycation Endproducts,RAGE)、磷酸化信号蛋白P38(Phosphorylated signal protein P38,P-P38)在非小细胞肺癌(Non-small-cell lung cancer,NSCLC)癌组织、癌旁正常组织中的表达并探讨RAGE与P-P38在NSCLC发生、发展过程中的相关性。方法采用免疫组化法检测52例NSCLC癌组织及47例癌旁正常肺组织中RAGE、P-P38的表达情况,分析其表达水平与NSCLC患者临床病理特征间的关系,并探讨其相关性。结果 RAGE在NSCLC中的表达率(63.46%)明显低于正常肺组织(100%)中的表达率(P0.05),P-P38在NSCLC组织中的表达率为55.77%,明显高于正常肺组织(21.28%)中的表达率(P0.05);RAGE和P-P38的表达均与肿瘤大小、淋巴结转移、TNM分期有关(P0.05),相关性分析显示,NSCLC中RAGE和P-P38的表达呈负相关性(r=-0.354,P0.05)。结论 NSCLC组织中存在RAGE低表达,P-P38高表达,RAGE表达的降低与P-P38表达的增高提示较高恶性生物学行为。在NSCLC组织中,RAGE和P-P38可能是有利于临床判断肿瘤恶性程度及指导临床治疗的生化指标。     

HMGB1/RAGE信号与呼吸系统疾病及其研究进展

高迁移率族蛋白1(HMGB1)广泛参与机体各种炎症反应过程,晚期糖基化终产物受体(RAGE)和部分Toll样受体家族是其主要作用受体。已有大量研究证实HMGB1通过RAGE受体途径,可诱导炎症反应、免疫应答、肿瘤发生多种生理病理学效应,参与多种疾病的发生发展。在肺组织中HMGB1有广泛表达,而HMGB1/RAGE信号已被证实参与诸多慢性气道疾病的发病过程。尤其是在哮喘的发生发展过程中,HMGB1/RAGE信号被证实在其中发挥重要作用,但具体机制仍不清。本文初步阐述HMGB1/RAGE在呼吸系统疾病尤其是哮喘发病中的作用及相关研究进展。     

Nε-羧甲基赖氨酸通过RAGE促进平滑肌细胞源性泡沫细胞形成

目的研究Nε-羧甲基赖氨酸(CML)对平滑肌细胞泡沫化中脂质外流的影响,探讨其在促进平滑肌细胞泡沫化中的作用和机制。方法使用组织贴块法从C57BL/6J小鼠主动脉中提取原代血管平滑肌细胞并进行鉴定;将第3~9代的原代平滑肌细胞分为对照组,氧化型低密度脂蛋白(ox-LDL)(50 mg/L)模型组,1、10、100μmol/L的CML与ox-LDL共刺激组,通过NBD-胆固醇流出实验检测CML对泡沫细胞胆固醇流出率的影响,通过胆固醇含量测定试剂盒测定细胞内总胆固醇(TC)、游离胆固醇(FC)和胆固醇酯(CE)水平;将原代血管平滑肌细胞分为四组:对照组、ox-LDL模型组、ox-LDL+CML组、RAGE siRNA沉默组(ox-LDL+CML+siRAGE组)并进行刺激,通过Western blot检测糖基化终末产物受体(RAGE)和胆固醇流出调节子ABCA1的表达;通过油红O染色和油红萃取实验检测各组平滑肌细胞泡沫化程度。结果与对照组相比,不同浓度CML明显升高平滑肌细胞内TC、CE和FC的含量;胆固醇流出实验表明胆固醇流出率随CML浓度升高而降低;Western blot实验表明与对照组相比,加入CML后RAGE明显升高,ABCA1明显降低,ox-LDL+CML+siRAGE组RAGE的表达降低,并且ABCA1降低水平减少;油红O染色显示ox-LDL能够促使平滑肌细胞内脂质蓄积,CML能够增强其作用,抑制RAGE表达后CML作用减弱。结论 CML通过RAGE抑制脂质外流,促进平滑肌细胞源性泡沫细胞形成。     

细胞外段V/VC1区缺失RAGE真核表达载体的构建、转染及在前列腺癌细胞中的表达和定位

目的构建带HA标签的晚期糖基化终产物受体(RAGE)不同功能段缺失体真核细胞表达载体,使其在前列腺癌细胞株PC-3中过表达并观察其定位。方法采用PCR方法扩增缺失不同功能段V/VC1的RAGE缺失体ΔV/ΔVC1序列,利用分子克隆技术将其重组于pcDNA3-HA载体中,利用PCR和测序鉴定克隆正确性;转染PC-3细胞,用Western blot法检测其表达,免疫荧光法检测其在细胞中的定位。结果 RAGE不同缺失体质粒经测序鉴定无误,并可在PC-3细胞中高表达,且经免疫荧光检测其主要在细胞质中表达。结论成功构建了RAGE不同缺失体的真核表达载体,转染PC-3细胞后呈高表达,其在PC-3细胞中主要定位于细胞质。     

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.     

The RAGE axis and endothelial dysfunction: maladaptive roles in the diabetic vasculature and beyond

Receptor for advanced glycation end product (RAGE) is a member of the immunoglobulin superfamily of cell surface molecules. The ligand-RAGE axis is emerging as a central mechanism linked to vascular injury and atherosclerosis in diabetes and in euglycemia. The repertoire of RAGE ligands, including advanced glycation end products, S100/calgranulins, high-mobility group box 1, amyloid-beta peptide, and Mac-1, transcends RAGE biology from specifically the science of diabetic complications to central aspects of the inflammatory response and oxidative stress. Experiments in cell culture and in vivo support the notion that interaction of RAGE ligands with RAGE activates key signal transduction pathways that modulate fundamental cellular properties, thereby leading to vascular and inflammatory cell perturbation. These considerations support the premise that the ligand-RAGE axis may be an important target for therapeutic intervention in cardiovascular disease and, fundamentally, in initiation and amplification of inflammatory responses.     

Metformin reduces endothelial cell expression of both the receptor for advanced glycation end products and lectin-like oxidized receptor 1

Beyond its antihyperglycemic action, the antidiabetic oral drug metformin possesses antioxidant properties that may contribute to improve the cardiovascular deleterious effects of the diabetic disease. We explored whether metformin could modulate the redox-sensible expression of receptor for advanced glycation end products (RAGE) and lectin-like oxidized receptor 1 (LOX-1), 2 endothelial membrane receptors involved in the arterial endothelial dysfunction observed in diabetes. Bovine aortic endothelial cells, either unstimulated or activated by high levels of glucose (30 mmol/L) or advanced glycation end products, were incubated for 72 hours with metformin at therapeutically relevant concentrations (10(-5) to 5 x 10(-4) mol/L). The expressions of RAGE and LOX-1 were evaluated on cell extracts by Western blot analysis. Metformin was shown to reduce, in dose-dependent manner, such expression of the 2 receptors, both in stimulated (by either glucose or advanced glycation end products) and in unstimulated cells. The effect of metformin was associated with a decrease in intracellular reactive oxygen species as assessed using the 2',7'-dichlorodihydrofluorescein diacetate fluoroprobe. Taken together, our results suggest that the intracellular antioxidant properties of metformin may result in the inhibition of cell expression of both RAGE and LOX-1, possibly through a modulation of redox-sensible nuclear factors such as nuclear factor kappaB, that were shown to be involved in such receptor cell expression.     

Atherosclerosis and restenosis: Is there a role for rage?

Diabetic vascular complications are a major cause of morbidity and mortality. Furthermore, such vascular disease is only incompletely explained by "traditional" risk factors in the nondiabetic complications. This situation has prompted the search for factors contributing to the pathogenesis of accelerated and more severe vascular disease in patients with diabetes. We review evidence that receptor for advanced glycation end products (RAGE), via its interaction with ligands, serves as a cofactor exacerbating diabetic vascular disease. RAGE is a member of the immunoglobulin superfamily of cell surface molecules with a diverse repertoire of ligands reminiscent of pattern recognition receptors. In the diabetic milieu, two classes of RAGE ligands, products of nonenzymatic glycoxidation and S100 proteins, appear to drive receptor-mediated cellular activation and, potentially, acceleration of vascular disease.     

Activation of receptor for advanced glycation end products: a mechanism for chronic vascular dysfunction in diabetic vasculopathy and atherosclerosis

Receptor for advanced glycation end products (RAGE) is a member of the immunoglobulin superfamily of cell surface molecules and engages diverse ligands relevant to distinct pathological processes. One class of RAGE ligands includes glycoxidation products, termed advanced glycation end products, which occur in diabetes, at sites of oxidant stress in tissues, and in renal failure and amyloidoses. RAGE also functions as a signal transduction receptor for amyloid beta peptide, known to accumulate in Alzheimer disease in both affected brain parenchyma and cerebral vasculature. Interaction of RAGE with these ligands enhances receptor expression and initiates a positive feedback loop whereby receptor occupancy triggers increased RAGE expression, thereby perpetuating another wave of cellular activation. Sustained expression of RAGE by critical target cells, including endothelium, smooth muscle cells, mononuclear phagocytes, and neurons, in proximity to these ligands, sets the stage for chronic cellular activation and tissue damage. In a model of accelerated atherosclerosis associated with diabetes in genetically manipulated mice, blockade of cell surface RAGE by infusion of a soluble, truncated form of the receptor completely suppressed enhanced formation of vascular lesions. Amelioration of atherosclerosis in these diabetic/atherosclerotic animals by soluble RAGE occurred in the absence of changes in plasma lipids or glycemia, emphasizing the contribution of a lipid- and glycemia-independent mechanism(s) to atherogenesis, which we postulate to be interaction of RAGE with its ligands. Future studies using mice in which RAGE expression has been genetically manipulated and with selective low molecular weight RAGE inhibitors will be required to definitively assign a critical role for RAGE activation in diabetic vasculopathy. However, sustained receptor expression in a microenvironment with a plethora of ligand makes possible prolonged receptor stimulation, suggesting that interaction of cellular RAGE with its ligands could be a factor contributing to a range of important chronic disorders.     

晚期糖基化终末产物受体及其配体在骨代谢疾病中作用的研究进展

晚期糖基化终末产物受体(RAGE)是具有多种配体的免疫球蛋白超家族成员,参与多种疾病的发病机制,包括神经退行性疾病阿尔茨海默病、糖尿病并发症以及多种与衰老、炎症相关的疾病,在调节先天免疫反应中起着关键作用.RAGE及其配体不仅是多种炎症反应的重要细胞因子,而且在骨髓间充质干细胞、成骨细胞及破骨细胞均表达RAGE.近年来...     

Receptor for advanced glycation end products (RAGE) in vascular and inflammatory diseases

Historically, the receptor for advanced glycation end products (RAGE) was thought to exclusively play an important role under hyperglycemic conditions. However, more and more evidence suggests that RAGE in fact is an inflammation perpetuating multi-ligand receptor and participates actively in various vascular and inflammatory diseases even in normoglycaemic conditions. Various ligands include advanced glycation end products (AGEs), S100 proteins and amphoterins etc. Besides full-length RAGE, numerous truncated forms of the receptor have also been described including the well-characterized soluble RAGE (sRAGE). sRAGE has an ability to act as a decoy to avoid interaction of RAGE with its pro-inflammatory ligands. Ligand engagement of RAGE activates multiple signaling pathways and also forms a positive feedback loop for its own enhanced expression. This review will discuss the role of multi-ligand receptor i.e. RAGE in context to various vascular diseases, which have a pathophysiologically important inflammatory component in normoglycaemic conditions.     

The biology of RAGE and its ligands: Uncovering mechanisms at the heart of diabetes and its complications

The interaction of glucose-modified and inflammation-promoting ligands with the receptor for advanced glycation end products (RAGE) is emerging as a central mechanism contributing to the diverse complications of diabetes. These ligands, particularly in oligomeric form, bind to RAGE and transduce intracellular signals. The consequences of this interaction, as elucidated in cultured cells and animal models, include upregulation of inflammatory and tissue-degradative pathways. Pharmacologic antagonism of RAGE may hold promise for the treatment of diabetic complications.     

RAGE‐ligands axis: A new ‘driving force’ for cigarette smoke‐induced airway inflammation in COPD?

Receptor for advanced glycation end products (RAGE) was recently shown to contribute to cigarette smoke (CS)‐induced airway inflammation in chronic obstructive pulmonary disease (COPD). In this study, RAGE small interfering ribonucleic acid (RNA) transfection attenuated increased messenger RNA levels of common RAGE ligands HMGB1, S100A8, S100A9 and S100A12, but not S100B following exposure to CS extract. Our findings and those from recent studies suggest a positive feedback involving RAGE and its ligands as a new ‘driving force’ for CS‐induced airway inflammation in COPD.