糖基化终产物与糖尿病血管并发症

糖尿病时糖基化终产物(advanced glycation end products,AGEs)生成与蓄积不仅加速糖尿病本身的发展,还与糖尿病肾病、视网膜病、神经性疾病和心血管疾病等慢性并发症密切相关。AGEs与糖基化终产物受体(receptor for advanced glycation end products,RAGE)相互作用诱导氧化应激,促进炎症反应,影响凝血系统,在糖尿病及其并发症的病理生理过程中起重要作用。抑制AGEs生成、交联结构及阻断AGEs与RAGE相互作用为寻找治疗糖尿病血管并发症的药物提供了新的途径。     

晚期糖化终产物受体与糖尿病血管病变

血管病变是糖尿病慢性并发症的主要病理基础,参与糖尿病血管病变发生的单核吞噬细胞、血管内皮、平滑肌的细胞膜都有晚期糖化终产物（ＡＧＥｓ） 受体分布。ＡＧＥｓ 受体有多种,某些多配体受体也能结合ＡＧＥｓ。受体与ＡＧＥｓ 结合后引起细胞对ＡＧＥｓ 进行清除或转运,同时发生细胞生长及合成等功能的改变。ＡＧＥｓ 受体介导的细胞效应是发生血管病变的重要原因     

糖基化终产物与糖尿病血管并发症关系的研究进展

糖尿病是临床上一种常见病和多发病 ,血管并发症是糖尿病的主要致残及致死原因。流行病学调查资料表明 ,糖尿病患者发生动脉粥样硬化及危及生命的心血管并发症的危险性较常人增加 3- 4倍 ,而高血糖状态下蛋白质发生的非酶糖基化对糖尿病血管并发症起了重要作用。大量的资料已证明 ,糖尿病患者体内存在着一种重要的毒性产物———糖基化终产物 (ａｄｖａｎｃｅｄｇｌｙｃｏｓｙｌａｔｉｏｎｅｎｄｐｒｏｄ ｕｃｔｓ,ＡＧＥｓ)。本文对有关ＡＧＥｓ在糖尿病血管病变中致病作用的研究进展综述如下 :一、ＡＧＥｓ的生物化学特性及结构早在 1 91 …     

温筋通对糖尿病大鼠心血管组织糖基化终产物的形成及其受体和ICAM-1表达的影响

目的:研究中药复方温筋通(WJT)对糖尿病大鼠心血管糖基化终产物(AGEs)的形成以及AGEs受体(RAGE)和细胞间粘附因子-1(ICAM-1)表达的影响。方法:用链脲佐菌素复制糖尿病大鼠模型。采用荧光法、RT-PCR和原位杂交的方法对心血管组织AGEs的沉积以及RAGE和ICAM-1的表达进行检测。结果:WJT治疗组AGEs形成量明显低于糖尿病模型组(P＜0.01),其治疗作用与AG相当;RAGE和ICAM-1主要在内皮细胞表达,其表达量与AGEs的沉积量呈明显正相关(P＜0.01)。结论:WJT可明显降低糖尿病大鼠主动脉和心肌组织AGEs的形成量以及RAGE和ICAM-1的表达。     

糖基化终产物对糖尿病微血管病变的作用

糖尿病不仅是一种慢性终身性疾病,它又是多脏器疾病并累及多数脏器,已成为仅次于脑血管和肿瘤之后,第三位的常见病、多发病和慢性非传染性疾病.根据流行病学调查,糖尿病的发病率呈逐年上升的趋势.     

糖基化终产物在糖尿病大鼠心肌病变中的作用

目的观察糖尿病心肌病变过程中心肌组织糖基化终产物（advanced glycosylation endproducts,AGEs）的变化,探讨AGEs对糖尿病大鼠心肌的影响。方法建立糖尿病大鼠模型,随机分为对照组（CON）、糖尿病组（DM）和氨基胍治疗组（AG）,饲养12周。分别测定各组大鼠血糖、血清LDH、CK活性、心脏重量指数、血清果糖胺（FMN）及AGEs含量、电镜观察心肌超微结构。结果DM组大鼠血糖、血清LDH、CK活性、心脏重量指数、血清果糖胺（FMN）及AGEs含量明显高于CON组。超微结构显示心肌肌原纤维排列紊乱,间质胶原增生,微血管基底膜增厚,管腔狭窄。AG组大鼠血清LDH、CK活性、心脏重量指数、血清果糖胺（FMN）及AGEs含量明显降低。微血管基底膜增厚减轻,问质胶原减少,心肌细胞超微结构异常减轻。结论AGEs在糖尿病心肌改变的发生中起重要作用。     

糖基化终产物对人单核细胞源树突状细胞糖基化终产物受体表达的研究

目的：探讨糖基化终产物 (AGEs）)对人单核细胞源树突状细胞（MDCs）糖基化终产物受体（RAGE） 表达的影响。 方法： 用免疫磁珠分离人外周血CD14+单核细胞，经含rhGM-CSF（100 μg/L）和rhIL-4（50 μg/L）的RPMI-1640培养，使其分化为MDCs，采用RT-PCR和Western blotting法，观察糖基化-白蛋白（AGE-BSA）对MDCs RAGE mRNA和蛋白表达的影响，同时检测培养液上清中IFN-γ和IL-12的浓度。 结果： AGE-BSA诱导DCs RAGE mRNA和蛋白的表达（P＜0.05），高于空白对照组，并且明显促进了DCs IFN-γ和IL-12的分泌（P＜0.05）。BSA干预组与空白对照组相比差异无显著（P＞0.05）。 结论： AGEs能够上调DCs RAGE的表达，并且促进了DCs IFN-γ和IL-12的分泌，这可能是糖尿病通过DCs促进动脉粥样硬化发生的重要机制之一。     

LPS和TNF—α诱导血管内皮细胞ICAM—1蛋白表达的比较

目的和方法 采用细胞间免疫荧光染色和激光共聚焦显微镜扫描技术,研究脂多糖（LPS）和肿瘤坏死因子α（TNF－α）对人脐静脉内皮细胞（HUVEC）表面细胞间粘附分子－1（ICAM－1）表达的诱导作用。结果 与内皮细胞表明ICAM－1的基础表达相比,LPS可诱导内皮细胞表面ICAM－1表达在第8－24h显著增加,但第36h有较明显的下降;TNF－α也可诱导内皮细胞表面ICAM－1表达在第8－24h显著增加,并在36h仍维持在较高水平。LPS和TNF－α与内皮细胞ICAM－1表达之间存在剂量反应关系。结论 LPS和TNF－α可诱导血管内皮细胞ICAM－1的表达,但内皮细胞在表达ICAM－1时对LPS的长期刺激可能产生耐受性。     

石香膏干预糖尿病溃疡创面模型大鼠创面组织晚期糖基化终产物及其受体与内皮型一氧化氮合成酶表达的变化

背景:糖尿病溃疡作为糖尿病的常见并发症之一,其低愈合率和高截肢率已严重危害人类健康,尽管目前多种中医外用膏药已证实能促进创面愈合,但其发挥作用的分子机制尚未明确.目的:探讨石香膏治疗糖尿病溃疡创面的可能作用机制.方法:将40只清洁级雄性SD大鼠随机分正常对照组、糖尿病溃疡组、细胞生长因子组、石香膏组,每组10只.除正常...     

糖基化终产物与心脑肾疾病的关系

８０年代初Ｇｅｒａｍｉ和Ｂｒｏｗｌｅｅ等首先报道糖尿病患者持久的高血糖状态会导致许多结构功能蛋白和核酸蛋白非酶糖基化，这在糖尿病慢性并发症的发生中占有重要地位，且与衰老过程密切相关。近两年来的研究表明,其病理意义比原来预计的更广泛。不仅与衰老、尿毒症与透析相关疾病和Ａｌｚｈｅｉｍｅｒ＇ｓ病密切相关,且与胞浆及核蛋白如转录因子、原癌基因和肿瘤抑制因子的糖基化有关,很可能是一种以前未发现的类似于蛋白质磷酸化的重要调控方式。本文就这一领域的国际研究动态并结合我们的初步研究结果作一报告。１糖基化终产物及其…     

Understanding RAGE, the receptor for advanced glycation end products

Advanced glycation end products (AGEs), S100/calgranulins, HMGB1-proteins, amyloid- peptides, and the family of -sheet fibrils have been shown to contribute to a number of chronic diseases such as diabetes, amyloidoses, inflammatory conditions, and tumors by promoting cellular dysfunction via binding to cellular surface receptors. The receptor for AGEs (RAGE) is a multiligand receptor of the immunoglobulin superfamily of cell surface molecules acting as counter-receptor for these diverse molecules. Engagement of RAGE converts a brief pulse of cellular activation to sustained cellular dysfunction and tissue destruction. The involvement of RAGE in pathophysiologic processes has been demonstrated in murine models of chronic disease using either a receptor decoy such as soluble RAGE (sRAGE), RAGE neutralizing antibodies, or a dominant-negative form of the receptor. Studies with RAGE^–/– mice confirmed that RAGE contributes, at least in part, to the development of late diabetic complications, such as neuropathy and nephropathy, macrovascular disease, and chronic inflammation. Furthermore, deletion of RAGE provided protection from the lethal effects of septic shock caused by cecal ligation and puncture (CLP). In contrast, deletion of RAGE had no effect on the host response in delayed-type hypersensitivity (DTH). Despite the lack of effect seen in adaptive immunity by the deletion of RAGE, administration of the receptor decoy, sRAGE, still afforded a protective effect in RAGE^–/– mice. Thus, sRAGE is likely to sequester ligands, thereby preventing their interaction with other receptors in addition to RAGE. These data suggest that, just as RAGE is a multiligand receptor, its ligands are also likely to recognize several receptors in mediating their biologic effects.     

糖基化终产物和高糖对小牛主动脉血管细胞的损伤作用

目的研究糖基化终产物（AGEs）和高浓度葡萄糖对血管细胞的损伤及对其糖基化终产物受体（RAGE）表达的影响。方法分别用10g/L糖基化终产物、10mol／L葡萄糖和两者的混合作用于牛主动脉血管细胞，利用生化方法测定细胞乳酸脱氢酶（IDH）、还原型谷胱甘肽（GSH）和NO2^-／NO3^-的含量，用MTT法测定细胞的活性。用CELL-ELISA和RT-PCR检测细胞RAGE的表达。结果与正常组（C）相比，高糖组（G）、AGEs组（A）和联合损伤组（G＋A）对主动脉内皮细胞的生长有明显的抑制作用（P〈0．01）和对平滑肌细胞的生长有明显的促进作用，主动脉血管细胞LDH的泄漏量明显增高，GSH和NO2^-／NO3^-的含量明显减少（P〈0．01）；且在的作用最强。同时，联合损伤组血管细胞的RAGE表达水平明显高于AGEs组和高糖组。结论AGEs比高浓度葡萄糖更具损伤血管细胞的作用，且AGEs与高糖联合作用对细胞的损伤最为明显，这种联合损伤的过程也是通过RAGE介导的。联合损伤组     

晚期糖基化终末产物对骨组织细胞代谢的影响

文题释义： 晚期糖基化终末产物：是还原糖(如葡萄糖)和某些代谢产物(如甲基已二醛)与蛋白质氨基经过非酶促反应生成的多种化合物,可以积聚在骨组织中,影响骨组织的结构和力学性能,导致骨强度显著下降。 骨胶原交联：骨胶原分子交联包括有利的酶催化交联(即未成熟的二价交联、成熟的三价交联)和不利的非酶催化交联。在骨组织发育过程中,胶原分子在酶催化的情况下,形成不成熟的二价交联,其中一部分二价交联进一步成熟形成三价交联;而在无酶催化情况下交联反应可形成晚期糖基化终末产物。 背景：随着骨组织工程学的研究和发展,发现晚期糖基化终末产物可以在骨组织中积累,影响骨骼的结构及生物力学性能。目前许多研究发现晚期糖基化终末产物/晚期糖基化终末产物受体通过特殊的作用机制后能够引起以成骨细胞、破骨细胞及骨细胞为主的骨组织细胞发生病理改变,导致骨重建失衡,骨骼强度下降,骨折发生率增加。 目的：综述晚期糖基化终末产物对骨骼生物力学的影响以及晚期糖基化终末产物/晚期糖基化终末产物受体对骨组织细胞的作用机制。 方法：由第一作者检索2005年1月至 2019年 7 月在PubMed、Web of Science 和 Medline数据库发表的有关晚期糖基化终末产物/晚期糖基化终末产物受体对骨组织细胞代谢的影响的文章,检索结果限于英文文献。 结果与结论：最终选取具有代表性的54篇文献进行归纳总结。晚期糖基化终末产物对骨胶原交联的影响,使得骨强度显著下降;晚期糖基化终末产物/晚期糖基化终末产物受体通过使骨组织细胞发生病理机制改变影响骨代谢,使得骨组织细胞发生本质改变。最终导致骨代谢平衡紊乱,骨骼脆性增加。骨质疏松症的发生与骨代谢相关的细胞活力改变有着直接关系,但具体相关作用机制需进一步研究,而这种特殊机制的改变在今后有可能为骨质疏松症提供独特的病理机制、诊断思维和相关治疗及预防策略。 中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程     

Paeoniflorin protects HUVECs from AGE-BSA-induced injury via an autophagic pathway by acting on the RAGE

The aim of our study was to investigate the protective effects of Paeoniflorin (PF) against injury induced by AGE-modified bovine serum albumin (AGE-BSA) in human umbilical vein endothelial cells (HUVECs), and to examine the underlying mechanisms of these effects. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was used to determine cell viability. Protein expression levels were determined by western blotting. For function-blocking experiments, we used small interfering RNA molecules (siRNA) for function-blocking experiments. At 6 h, we found that 100 μg/mL AGE-BSA reduced the viability of HUVECs. However, pretreatment with PF restored cell viability in a dose-dependent manner. AGE-BSA increased the levels of microtubule-associated protein light chain 3-II (LC3-II) and the receptor for advanced glycation end products (RAGE). Expression of p62 protein was also increased, but not at a statistically significant level. Pretreatment with PF further increased levels of LC3-II and RAGE, but reduced the expression of p62. In cells transfected with Atg5 and RAGE siRNA, cell viability and expression of LC3-II decreased in both the AGE-BSA and PF + AGE-BSA treatments. PF can protect HUVECs from AGE-BSA-induced injury by upregulating autophagy and promoting the completion of autophagy flux. RAGE plays an important role in this autophagic protection effect.     

Immunofluorescence detection of advanced glycation end products (AGEs) in cookies and its correlation with acrylamide content and antioxidant activity

Food processing induces protein modifications by Maillard reactions. This generates advanced glycation end products (AGEs) that are known to affect human health. Therefore, it is of interest to monitor AGEs in food products. Currently Maillard products are detected by measuring fluorescence. However, several AGEs are non-fluorescent, while non-AGE components can exhibit autofluorescence. Therefore, specific AGE immunodetection was investigated. Immunofluorescence of AGEs as well as autofluorescence were determined in cookie extracts. Autofluorescence increases with baking time and sugar level, where AGE immunofluorescence increases with baking time until 20 minutes. Replacing sucrose by fructose confirmed the higher reactivity of fructose in AGE formation. The pattern of autofluorescence correlates well with the acrylamide and antioxidant activity. However, the immunodection of AGEs did not show such a correlation. At higher baking times the autofluorescence probably results from the generation of non-proteineious compounds. The immunofluorescence reduction likely results from the transient character of AGE epitopes.     

Advanced glycation end products induce actin rearrangement and subsequent hyperpermeability of endothelial cells

This study aimed to determine the effects of advanced glycation end products (AGEs) on endothelial cytoskeleton morphology and permeability, and to detect the underlying signaling mechanisms involved in these responses. Cultured endothelial cells (ECs) were exposed to AGE-modified human serum albumin (AGE-HSA), and EC cytoskeletal changes were evaluated by observing fluorescence of F-actin following ligation with labeled antibodies. Endothelial permeability was detected by measuring the flux of TRITC-albumin across the EC monolayers. To explore the signaling pathways behind AGE-induced EC alteration, ECs were treated with either soluble anti-AGE receptor (RAGE) IgG, or the MAPK inhibitors PD98059 and SB203580 before AGE-HSA administration. To further elucidate possible involvement of the ERK and p38 pathways in AGE-induced EC changes, adenovirus-carried recombinant constitutive dominant-negative forms of upstream ERK and p38 kinases, namely MEK1(A) and MKK6b(A), were pre-infected into ECs 24 h prior to AGE-HSA exposure. AGE-HSA induced actin cytoskeleton rearrangement, as well as EC hyperpermeability, in a dose and time-dependent manner. The effects were attenuated in cells pretreated with anti-RAGE IgG, PD98059 or SB203580, respectively. EC pre-infection with MEK1(A) and MKK6b(A) also alleviated the effect of AGEs. Furthermore, adenovirus-mediated administration of activated forms of either MEK1 or MKK6b alone induced rearrangement of F-actin and hyperpermeability. The results indicate that ERK and p38 MAPK play important roles in the mediation of AGE-induced EC barrier dysfunction associated with morphological changes of the F-actin.     

梓醇抑制AGEs诱导的EA.hy926细胞炎症反应及RAGE表达

目的:研究梓醇对晚期糖基化终产物(AGEs)诱导的EA.hy926内皮细胞炎症反应的抑制作用并探讨其可能机制。方法:将常规培养的EA.hy926细胞随机分为对照组、梓醇对照组、AGEs组以及梓醇高剂量(0.5 mmol/L)、中剂量(0.25 mmol/L)和低剂量(0.05 mmol/L)保护组。激光共聚焦显微镜观察细胞内活性氧簇(ROS)的生成;RT-PCR和Western blot检测细胞中单核细胞趋化蛋白1(MCP-1)、肿瘤坏死因子α(TNF-α)、血管细胞黏附分子1(VCAM-1)及晚期糖基化终产物受体(RAGE)的mRNA及蛋白的表达。结果:梓醇保护组ROS生成均明显减少,MCP-1、TNF-α和VCAM-1的mRNA及蛋白表达均显著降低,RAGE蛋白表达明显受抑制,且呈剂量依赖性(P0.05)。结论:梓醇能够有效抑制AGEs诱导的EA.hy926细胞内氧化应激,减轻炎症反应,其机制可能与其降低RAGE表达有关。     

Pitavastatin attenuates AGEs-induced mitophagy via inhibition of ROS generation in the mitochondria of cardiomyocytes

This study aimed to investigate whether pitavastatin protected against injury induced by advanced glycation end products products (AGEs) in neonatal rat cardiomyocytes, and to examine the underlying mechanisms. Cardiomyocytes of neonatal rats were incubated for 48 hours with AGEs (100 mg/mL), receptor for advanced glycation end products (RAGE), antibody (1 mg/mL) and pitavastatin (600 ng/mL). The levels of p62 and beclin1 were determined by Western blotting. Mitochondrial membrane potential (DYm) and the generation of reactive oxygen species (ROS) were measured through the JC-1 and DCFH-DA. In the AGEs group, the expression of beclin1 was remarkably increased compared to the control group, while the expression of p62 was significantly decreased. AGEs also markedly decreased DYm and significantly increased ROS compared with the control group. After treatment with RAGE antibody or pitavastatin, the level of beclin1 was markedly decreased compared with the AGEs group, but the level of p62 was remarkably increased. In the AGEs + RAGE antibody group and AGEs + pitavastatin group, DYm was significantly increased and ROS was remarkably decreased compared with the AGEs group. In conclusion, AGEs-RAGE may induce autophagy of cardiomyocytes by generation of ROS and pitavastatin could protect against AGEs-induced injury against cardiomyocytes.