S-亚硝基谷胱苷肽对糖基化终产物诱导的大鼠主动脉平滑肌细胞增生的影响

为探讨脂溶性NO前体药物S 亚硝基谷胱苷肽 (S nitrosoglutathione ,GSNO)对糖基化终产物 (advancedglycosyla tionendproducts ,AGEs)诱导的大鼠血管平滑肌细胞增生的影响 ,利用体外培养的大鼠胸主动脉平滑肌细胞 ,用MTT法、同位素掺入法及细胞计数法测定其增殖率的变化 ,观察不同浓度的AGEs对血管平滑肌细胞的增殖的影响以及不同浓度的GSNO对AGEs作用的预防和逆转作用。MTT法测定的OD值、3 H 胸腺嘧碇核苷 (3 H TDR)掺入量、细胞计数均显示AGEs可以使血管平滑肌细胞数明显高于对照组 (P <0 0 5 ) ;而用GSNO干预后 ,AGEs的上述作用被明显抑制 (P <0 0 5 )。提示NSNO可以抑制AGEs诱导的血管平滑肌细胞的增殖     

晚期糖基化终产物对血管通透性的影响和作用机制

血管通透性的增高是糖尿病血管并发症的一个标志性事件[1],是其发生的最初表现和导致其他后续改变的病理基础.随着对晚期糖基化终产物(advanc-ed glycation end products,AGEs)及其特异性受体(rece-ptor for advanced glycation end products,RAGE)的结构及其病理机制研究的深入,AGEs在血管通透性增高中所起的重要作用引起了广泛的关注,我们就此作一综述.     

罗格列酮减轻糖基化终产物诱导的大鼠血管平滑肌细胞钙化

目的观察糖基化终产物(advanced glycation end products,AGEs)对血管平滑肌细胞钙化的影响以及罗格列酮对这种影响的干预作用,探讨罗格列酮在血管钙化产生中的作用。方法在含10mmol.L-1β-甘油磷酸培养液中加入200mg·mL-1的AGE-BSA及不同浓度(10-7mol.L-1～10-5mol.L-1)的罗格列酮体外培养大鼠血管平滑肌细胞,采用磷酸苯二钠法检测碱性磷酸酶活性,甲-酚酞络合酮方法测定细胞层钙含量,RT-PCR检测骨桥蛋白mRNA表达,Western blotting检测骨桥蛋白(osteopontin,OPN)蛋白表达。结果与对照组相比,AGE-BSA组细胞层钙含量增加、碱性磷酸酶活性升高,细胞OPNmRNA表达升高,OPN蛋白表达增加(P<0.01);10-7mol.L-1～10-5mol.L-1罗格列酮可抑制AGE-BSA对细胞的上述影响(P<0.01)。结论AGEs可促进血管平滑肌细胞钙化,罗格列酮可减轻AGEs对细胞的上述影响。     

高糖、高脂血症大鼠血管内皮细胞及平滑肌细胞的形态和功能改变

复制高糖、是动物模型,利用血管功能测定,组织培养和放射免疫分析等方法观察长期高糖,高脂血症对血管内皮细胞和平骨肌细胞功能的影响及相互作用,结果表明,高糖、高脂对血和内皮细胞均有影响,两者有协同作用;对血管平滑肌细胞两者均可促进其增强,加速了糖尿病血管并发症的发生发展。     

RAGE调节Wnt/β-catenin信号通路对DM大鼠主动脉保护作用的研究

检测2型糖尿病(type 2 diabetes, D2M)大鼠主动脉组织中Wnt/β-catenin信号通路相关蛋白以及晚期糖基化终末产物受体(receptor for advanced glycation end product, RAGE)表达水平,分析RAGE对Wnt/β-catenin信号通路的调节作用以及对大鼠主动脉病变的影响;检测血脂相关指标水平,分析血脂水平与糖尿病之间的关系。构建D2M大鼠模型,在第2、4、8、12周随机分组大鼠模型并设置空白对照组,检测空腹血糖、血清总胆固醇(serum total cholesterol,TC)、甘油三酯(triglyceride,TG)、高、低密度脂蛋白胆固醇(high density lipoprotein-cholesterol,HDL-C)(low density lipoprotein-cholesterol,LDL-C)、胰岛素等指标,HE染色观察主动脉组织病理结构;RT-PCR、Western blotting检测主动脉组织Wnt2、β-catenin、T细胞因子4(T cell factor 4,TCF4)、RAGE等相关指标mRNA及蛋白表达情况。结果显示,与空白对照组相比,D2M大鼠TC、TG、LDL-C水平显著升高,HDL-C水平显著下降;D2M大鼠不同时间段与第2周相比,TC、TG、LDL-C水平显著升高,HDL-C水平显著下降(P0.01,P0.05)。HE染色显示D2M大鼠主动脉局部内皮细胞发生不同程度的空泡变性或坏死。D2M大鼠在第2周与12 w内主动脉组织Wnt2和β-catenin mRNA及蛋白水平与空白对照组相比差异有统计学意义(P0.01),8 w后维持在较高水平;TCF4、RAGE水平较空白对照组持续上升(P0.05);分泌型卷曲相关蛋白2(secreted frizzled-related protein 2,sFRP2)水平较对照组持续下降(P0.01)。由此,RAGE通过调节Wnt/β-catenin信号通路影响D2M大鼠主动脉相关蛋白表达,可能对相关主动脉病变有保护作用。     

血管内皮细胞的活化或损伤诱导平滑肌细胞的增生和凋亡

一、材料与方法1.细胞培养 :采用改进的Ｊａｆｆｅ氏培养法 ,培养人脐带静脉内皮细胞。采用贴块法培养人脐动脉平滑肌细胞并传代。培养液均为含 2 0 %胎牛血清的ＤＭＥＭ培养液。2 .内皮细胞的脂质过氧化引发实验 :将培养达融合状态的内皮细胞分组 ,分别加入含不同浓度氢过氧化枯烯的培养液孵育后 ,测定脂质过氧化物的代谢终产物丙二醛 (ＭＤＡ)的含量。3.培养液中乳酸脱氢酶 (ＬＤＨ)活性的测定 :ＬＤＨ是细胞内的可溶性酶 ,当细胞膜被破坏时可漏出细胞外 ,可作为细胞损伤的早期检测指标。采取内皮细胞培养液 ,以Ｓｉｇｍａ公司的ＬＤＨ测…     

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     

L—精氨酸,牛磺酸对大鼠血管损伤后血管平滑肌细胞增生的影响

在大鼠血管内皮剥脱模型上，观察了Ｌ－精氨酸，牛磺酸及Ｌ－精氨酸＋牛磺酸对血管损伤诱导的血管平滑肌细胞增生的影响。结果发现，内皮剥脱可致ＶＳＭＣ增生，同膜增厚；应用Ｌ－精氨酸，牛磺酸及Ｌ－精氨酸＋牛磺酸治疗后，剥脱组ＶＳＭＣ增生明显受抑制，且Ｌ－精氨酸＋牛磺酸对ＶＳＭＣ的抑制效应强于单纯应用Ｌ－精氨酸或牛磺酸组；Ｌ－精氨酸及Ｌ－精氨酸＿＋牛磺酸治疗后，血管对乙酰胆碱的内皮依赖性舒张，血ｃＧＭＰ含量明     

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。     

晚期糖化终产物对糖尿病大鼠主动脉平滑肌细胞的影响

目的 探讨血管平滑肌细胞（ＶＳＭＣ）在糖尿病早期的改变及其与晚期糖化终产物（ＡＧＥｓ）的关系。方法 应用荧光分光光度法、免疫组织化学、计算机图像分析和透射电镜等技术,研究链脲佐菌素诱导的糖尿病（ＤＭ）大鼠血浆和腹主动脉晚期糖化终产物（ＡＧＥｓ）的含量以及腹主动脉ＶＳＭＣ的变化。结果 从４周起,ＤＭ大鼠血浆和腹主动脉的ＡＧＥｓ显著增多;腹主动脉α－ＳＭ－肌动蛋白的相对面积减小,ＣＳＭＣ的细胞核密度     

糖尿病大鼠血管糖基化终产物含量与其受体的ICAM—1表达的关系

探讨糖尿病大鼠血管组织糖基化终产物（AGEs)含量与其受体（RAGE）和细胞间粘附因子－1（ICAM－1）表达的关系。复制糖尿病大鼠模型,采用荧光法、RT－PCR及原位杂交方法检测主动脉及心肌组织的AGEs含量以及RAGE和ICAM－1基因的表达。发现糖尿病大鼠主动脉和心肌组织AGEs含量升高（P＜0．01）;RAGE和ICAM－1基因表达增强（P＜0．05－0．05）;AGEs含量与RAGE及ICAM－1呈明显正相关（P＜0．01）;氨基胍治疗可缓解上述指标的变化。提示 AGEs可诱导RAGE和ICAM－1的表达。推测AGEs-RAGE相互作用是引起糖尿病血管内皮细胞功能紊乱和损伤的关键环节。     

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.     

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.     

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。     

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.     

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.     

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.     

Advanced glycation end products reduce macrophage-mediated killing of Staphylococcus aureus by ARL8 upregulation and inhibition of autolysosome formation

Staphylococcus aureus, a pathogen most frequently found in diabetic foot ulcer infection, was recently suggested as an intracellular pathogen. Autophagy in professional phagocytes like macrophages allows selective destruction of intracellular pathogens, and its dysfunction can increase the survival of internalized pathogens, causing infections to worsen and spread. Previous works have shown that S. aureus infections in diabetes appeared more severe and invasive, and coincided with the suppressed autophagy in dermal tissues of diabetic rat, but the exact mechanisms are unclear. Here, we demonstrated that accumulation of advanced glycation end products (AGEs) contributed to the diminished autophagy-mediated clearance of S. aureus in the macrophages differentiated from PMA-treated human monocytic cell line THP-1. Importantly, infected macrophages showed increased S. aureus containing autophagosome, but the subsequent fusion of S. aureus containing autophagosome and lysosome was suppressed in AGEs-pretreated cells, suggesting AGEs blocked the autophagic flux and enabled S. aureus survival and escape. At the molecular level, elevated lysosomal ARL8 expression in AGEs-treated macrophages was required for AGEs-mediated inhibition of autophagosome-lysosome fusion. Silencing ARL8 in AGEs-treated macrophages restored autophagic flux and increased S. aureus clearance. Our results therefore demonstrate a new mechanism, in which AGEs accelerate S. aureus immune evasion in macrophages by ARL8-dependent suppression of autophagosome-lysosome fusion and bactericidal capability.