D-半乳糖诱导的衰老模型中RAGE和P21的表达和意义

目的探讨大鼠衰老模型中肝脏糖基化、氧化应激水平与糖基化终末产物受体(RAGE)、P21的蛋白表达之间的关系。方法建立衰老动物模型,荧光法检测肝脏高级糖基化终末产物(AGEs)含量,硫代巴比妥酸(TBA)法检测MDA含量,邻苯二甲醛(OPT)法检测GSH含量,western blot检测RAGE和P21表达水平。结果与对照组相比,模型组肝脏的AGEs和MDA含量显著升高,GSH含量显著降低;RAGE和P21蛋白表达水平显著升高。结论在D-半乳糖诱导的衰老模型中,氧化应激和糖基化水平的升高与RAGE和P21的高表达有关,认为RAGE介导的细胞反应促进了衰老过程。     

晚期糖基化终末产物及其受体与非酒精性脂肪性肝病的关系

晚期糖基化终末产物(AGE)是高血糖的标志物,能通过AGE受体(RAGE)发挥致病作用.研究发现,AGE/RAGE与非酒精性脂肪性肝病(NAFLD)的发展关系密切.AGE能增加肝脏的甘油三酯水平,促进单纯性脂肪肝(SFL)的发生,AGE/RAGE可诱导肝脏炎性反应,促进SFL向非酒精性脂肪性肝炎(NASH)发展,并能通过诱导活性氧簇的合成,活化肝脏星状细胞来引起肝纤维化.     

糖基化终末产物促进大鼠血管平滑肌细胞钙化

目的 观察糖基化终末产物对体外培养的血管平滑肌细胞钙化的影响.方法 在含10 mmol/Lβ-甘油磷酸钠培养液中加入不同浓度(0、50、100、200 mg/L和400 mg/L)的糖基化终末产物与大鼠血管平滑肌细胞孵育不同时间.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钙含量,实时定量逆转录聚合酶链反应检测成骨细胞特异性核心结合因子、碱性磷酸酶以及骨桥蛋白基因表达,蛋白免疫印迹检测成骨细胞特异性核心结合因子及骨桥蛋白蛋白表达.结果 与对照组相比,糖基化终末产物随作用时间延长和浓度增加,细胞钙含量增加(P<0.05),升高碱性磷酸酶活性和基因表达(P<0.05),促进成骨细胞特异性核心结合因子及骨桥蛋白基因及蛋白表达(P<0.01).结论 糖基化终末产物可促进体外培养的大鼠血管平滑肌细胞钙化.     

褪黑素对糖尿病大鼠心肌MDA、CAT及GSH-Px含量和AGE、RAGE表达的影响

目的研究褪黑素(RAGE)对糖尿病大鼠心肌组织中丙二醛(MDA)、过氧化氢酶(CAT)和谷胱甘肽过氧化物酶(GSH-Px)含量的影响及糖基化终末产物(AGE)和糖基化终末产物受体(RAGE)表达水平的改变。方法清洁级雄性Wistar大鼠,高脂高糖饮食,配合腹腔注射链脲佐菌素诱导糖尿病模型,随后给予低剂量[10 mg/(kg体重·d)]和高剂量[20 mg/(kg体重·d)]MT灌胃16 w。比色法测定心肌组织中MDA、CAT和GSH-Px含量变化;HE染色观察心肌组织病理改变;超敏二步免疫组化染色测定心肌组织中AGE和RAGE蛋白表达。结果经过MT处理16 w后,与模型组比较,低剂量MT组和高剂量MT组血糖值无明显变化(P0.05);与模型组比较,低剂量MT组和高剂量MT组心肌组织中MDA含量明显降低,CAT和GSH-Px含量明显升高(P0.05);HE染色显示低剂量MT组和高剂量MT组心肌结构损伤程度均较模型组轻;与模型组比较,低剂量MT组和高剂量MT组心肌组织中AGE和RAGE蛋白表达明显降低(P0.05)。结论 MT可以降低糖尿病大鼠心肌组织MDA含量,提高CAT和GSH-Px含量;可改善心肌结构变化;降低心肌中AGE和RAGE蛋白的表达。     

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.     

α-硫辛酸对2型糖尿病大鼠大脑皮质的保护作用

目的探讨α-硫辛酸对2型糖尿病(T2DM)大鼠大脑皮质的保护作用及机制。方法 SD大鼠随机分为5组:对照组、糖尿病模型组、α-硫辛酸低、中、高剂量组。对照组大鼠给予普通饮食1个月后腹腔注射等体积的不含链脲佐菌素(STZ)柠檬酸缓冲液,实验组大鼠给予高脂高糖饮食1个月后腹腔注射小剂量的STZ 30 mg/kg,建立T2DM模型。α-硫辛酸低、中、高剂量组分别按15、30、60 mg/kg灌胃12 w。检测血糖和糖化血红蛋白、糖基化终末产物(AGEs)等血清指标;光镜下观察大脑皮质形态学变化;免疫组织化学法核因子(NF)-κB、胶质纤维酸性蛋白(GFAP)、糖基化终末产物受体(RAGE)的含量变化;Western印迹法测定NF-κB、RAGE的蛋白表达情况。结果与对照组比较,糖尿病模型组大鼠血糖值和血清糖化血红蛋白及AGEs含量明显增高(P<0.05),光镜下大鼠皮质神经元数目减少并出现退行性变,脑皮质中NF-κB、GFAP、RAGE蛋白表达显著增加(P<0.05);与糖尿病模型组比较,α-硫辛酸中剂量组血糖、血清糖化血红蛋白及AGEs含量明显降低(P<0.05),光镜下大鼠皮质神经元数目增多,病变有所改善,α-硫辛酸中剂量组NF-κB、GFAP、RAGE表达分别为2.26、160.12、2.87明显减少(P<0.05)。结论α-硫辛酸对糖尿病大鼠大脑皮质有保护作用,其机制可能与抑制血糖、糖化血红蛋白及血清中的AGEs,下调NF-κB、GFAP、RAGE的表达,改善大脑退行性病变有关。     

灵芝多糖对2型糖尿病大鼠胸主动脉内皮功能的保护作用

目的 研究灵芝多糖在体内对糖尿病大鼠主动脉内皮功能的影响,并探讨灵芝多糖保护血管内皮的可能机制.方法 SD大鼠经过4周高脂饮食后腹腔注射链脲佐菌素(30 mg/kg)造模随机分为正常对照组、模型组、小檗碱组、灵芝多糖低、中及高剂量组(剂量分别为200、400和800 mg/kg).16周给药治疗后,切取胸主动脉,制成3 mm血管环,检测乙酰胆碱引起的内皮依赖性舒张反应,并测定血清中糖基化终末产物含量、过氧化氢酶、谷胱甘肽过氧化物酶、总胆固醇和甘油三酯水平.结果 灵芝多糖中剂量组和高剂量组血糖浓度较糖尿病模型组相比明显下降(P<0.01).灵芝多糖高剂量组血清糖基化终末产物、总胆固醇和甘油三酯含量较模型组相比明显下降(P<0.01),而血清过氧化氢酶水平和谷胱甘肽过氧化物酶水平则明显上升(P<0.01).结论 灵芝多糖对糖尿病大鼠主动脉内皮依赖性舒张反应的损害有明显的保护作用,其机制可能与抑制血清搪基化终末产物、增强机体内过氧化氢酶和谷胱甘肤过氧化物酶活性和调节血脂障碍有关.     

苦荞麦提取物对糖尿病大鼠肾脏糖基化反应的影响及机制

目的观察苦荞麦提取物对链脲佐菌素(STZ)诱导的糖尿病大鼠糖基化反应的影响。方法 STZ诱导建立糖尿病大鼠模型,然后分别给予苦荞麦高、中、低200,100,50 mg·kg-1·d-1剂量和氨基胍100 mg·kg-1·d-1治疗12 w。采用荧光分光光度法测定肾脏组织中糖基化终末产物(AGEs)及硫化巴比妥酸反应物(TBARS)含量;采用免疫印迹法测定肾脏组织中糖基化终末产物受体(RAGE)的蛋白表达水平。结果与正常组比较,模型组肾脏组织中AGEs含量及TBARS含量均显著升高,肾脏组织中RAGE的蛋白表达水平显著升高;与模型组比较,苦荞麦各剂量组及氨基胍组肾脏组织中AGEs含量及TBARS含量均显著降低,以苦荞麦高剂量组下降最明显(P<0.01);苦荞麦各剂量组及氨基胍组肾脏组织中RAGE的蛋白表达水平亦降低,以苦荞麦高剂量组下降明显(P<0.01)。结论苦荞麦能够抑制糖尿病大鼠体内的糖基化反应,并且随着苦荞麦剂量的增加,抑制作用更加明显。     

氯沙坦对自发性高血压大鼠糖基化终末产物及其受体诱导的血管损伤的影响

背景晚期糖基化终末产物(AGEs)及其受体 RAGE 系统在糖尿病靶器官损伤的病理过程中起非常重要的作用,有研究报道血管紧张素Ⅱ1型受体拮抗剂(ARB)能减少体内外2型糖尿病动物 AGEs 聚集以及氧化应激反应。目的探讨血管氧化应激与 AGE 水平及其受体 RAGE 及核转录因子(NF-kB)等在高血压血管损伤进程中的变化及氯沙坦对其损伤路径的影响。方法选30周龄自发性高血压大鼠(SHR)随机分为 SHR组、氯沙坦组[30 mg/(kg·d)],WKY 组为对照。干预12周,用放免法测定血浆血管紧张素Ⅱ(AngⅡ)水平;免疫荧光检测血管晚期糖基化终末产物(AGEs)表达;免疫组化法检测血管 RAGE 表达。RT-PCR 检测AT_1mRNA、NF-kB mRNA、NADPH 氧化酶 p47 phox mRNA 表达。结果 12周后,SHR 组的血压稳定在治疗前水平[(222±5)mmHg],氯沙坦组血压降至[(158±4)mmHg],且明显低于 SHR 组(P<0.01);氯沙坦组血浆AngⅡ水平达(67.4±5.4)pg/mL,明显高于 SHR 组[(49.5±4.6)pg/mL,P<0.01];氯沙坦组及...     

晚期糖基化终末产物受体及其配体的肿瘤生物学效应

晚期糖基化终末产物受体(RAGE)作为信号传导受体介导晚期糖基化终末产物(AGE)、高迁移率族蛋白B1(HMGB1)、钙粒蛋白(S100)、β粉样肽(A)等配体在细胞表面结合,激活细胞内多种信号传导机制,参与了糖尿病慢性并发症、炎症反应、神经再生、Alzheimer病、透析相关性淀粉样变(DRA)、动脉粥样硬化以及肿瘤生长、浸润转移等的生物学效应[1,2].     

慢阻肺急性加重期患者血浆晚期糖基化终末产物和sRAGE研究

目的研究分析慢性阻塞性肺疾病(慢阻肺)患者血浆中晚期糖基化终末产物(AGEs)和可溶性糖基化终末产物受体(sRAGE)的水平及与慢阻肺患者肺功能的关系。方法选取河北省承德县医院收治的120例慢阻肺患者(慢阻肺组)、50例健康人群(对照组),分别检测两组的血浆AGEs、sRAGE及肺功能等指标。结果慢阻肺组患者的血浆中AGEs(36.25±2.98)ug/m L显著的高于对照组的(28.94±2.31)ug/m L,sRAGE为(338.41±194.26)pg/m L显著的低于对照组的(871.50±226.49)pg/m L且差异均具有统计学意义(P0.05)。慢阻肺组患者血浆AGEs与患者的FEV1%呈显著的负相关关系(r=-0.594,P=0.0000.001);慢阻肺组患者血浆sRAGE与患者的FEV1%呈显著的正相关关系(r=0.552,P=0.0000.001)。结论慢阻肺患者血浆中AGEs、sRAGE水平发生显著的改变,AGEs与患者的肺功能呈负相关性、sRAGE与患者的肺功能呈正相关关系。     

Involvement of the TAGE-RAGE system in non-alcoholic steatohepatitis: Novel treatment strategies

Non-alcoholic fatty liver disease (NAFLD) is a major cause of liver disease around the world. It includes a spectrum of conditions from simple steatosis to non-alcoholic steatohepatitis (NASH) and can lead to fibrosis, cirrhosis, liver failure, and/or hepatocellular carcinoma. NAFLD is also associated with other medical conditions such as obesity, diabetes mellitus (DM), metabolic syndrome, hypertension, insulin resistance, hyperlipidemia, and cardiovascular disease (CVD). In diabetes, chronic hyperglycemia contributes to the development of both macro- and microvascular conditions through a variety of metabolic pathways. Thus, it can cause a variety of metabolic and hemodynamic conditions, including upregulated advanced glycation end-products (AGEs) synthesis. In our previous study, the most abundant type of toxic AGEs (TAGE); i.e., glyceraldehyde-derived AGEs, were found to make a significant contribution to the pathogenesis of DM-induced angiopathy. Furthermore, accumulating evidence suggests that the binding of TAGE with their receptor (RAGE) induces oxidative damage, promotes inflammation, and causes changes in intracellular signaling and the expression levels of certain genes in various cell populations including hepatocytes and hepatic stellate cells. All of these effects could facilitate the pathogenesis of hypertension, cancer, diabetic vascular complications, CVD, dementia, and NASH. Thus, inhibiting TAGE synthesis, preventing TAGE from binding to RAGE, and downregulating RAGE expression and/or the expression of associated effector molecules all have potential as therapeutic strategies against NASH. Here, we examine the contributions of RAGE and TAGE to various conditions and novel treatments that target them in order to prevent the development and/or progression of NASH.     

MK615 decreases RAGE expression and inhibits TAGE-induced proliferation in hepatocellular carcinoma cells

AIM:To investigate the proliferative effect of advanced glycation end-products(AGEs) and the role of their cellular receptor(RAGE) on hepatocellular carcinoma(HCC) cells,and the inhibitory effects of MK615,an extract from Japanese apricot,against AGEs were also evaluated.METHODS:Two HCC cell lines,HuH7 and HepG2,were used.Expression of RAGE was investigated by poly-merase chain reaction,Western blotting,and flow cytemetry(FACS).The effect of MK615 on RAGE expression was also evaluated by FACS.The proliferat...     

Contribution of the toxic advanced glycation end-products-receptor axis in nonalcoholic steatohepatitis-related hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide. The main etiologies of HCC are hepatitis B virus and hepatitis C virus (HCV), and non-hepatitis B/non-hepatitis C HCC (NBNC-HCC) has also been identified as an etiological factor. Although the incidence of HCV-related HCC in Japan has decreased slightly in recent years, that of NBNC-HCC has increased. The onset mechanism of NBNC-HCC, which has various etiologies, remains unclear; however, nonalcoholic steatohepatitis (NASH), a severe form of nonalcoholic fatty liver disease, is known to be an important risk factor for NBNC-HCC. Among the different advanced glycation end-products (AGEs) formed by the Maillard reaction, glyceraldehyde-derived AGEs, the predominant components of toxic AGEs (TAGE), have been associated with NASH and NBNC-HCC, including NASH-related HCC. Furthermore, the expression of the receptor for AGEs (RAGE) has been correlated with the malignant progression of HCC. Therefore, TAGE induce oxidative stress by binding with RAGE may, in turn, lead to adverse effects, such as fibrosis and malignant transformation, in hepatic stellate cells and tumor cells during NASH or NASH-related HCC progression. The aim of this review was to examine the contribution of the TAGE-RAGE axis in NASH-related HCC.     

Glycation and cardiovascular disease in diabetes: A perspective on the concept of metabolic memory

Epidemiological studies have suggested that cumulative diabetic exposure, namely prolonged exposure to chronic hyperglycemia, contributes to the increased risk of cardiovascular disease (CVD) in diabetes. The formation and accumulation of advanced glycation end‐products (AGEs) have been known to progress under hyperglycemic conditions. Because AGEs‐modified collagens are hardly degraded and remain in diabetic vessels, kidneys and the heart for a long time, even after glycemic control has been achieved, AGEs could become a marker reflecting cumulative diabetic exposure. Furthermore, there is a growing body of evidence that an interaction between AGEs and the receptor for AGEs (RAGE) plays a role in the pathogenesis of CVD. In addition, AGEs induce the expression of RAGE, thus leading to sustained activation of the AGEs–RAGE axis in diabetes. Herein we review the pathological role of the AGEs–RAGE axis in CVD, focusing particularly on the phenomenon of metabolic memory, and discuss the potential clinical usefulness of measuring circulating and tissue levels of AGEs accumulation to evaluate diabetic macrovascular complications.     

Advanced glycation end products depress function of endothelial progenitor cells via p38 and ERK 1/2 mitogen-activated protein kinase pathways

Objective  Advanced glycation end products (AGEs) and endothelial progenitor cells (EPCs) play divergent roles in the process of atherosclerosis. We investigated the effects of AGE-human serum albumin (AGE-HSA) on receptor expression for AGEs (RAGE) and EPCs apoptosis. Methods  The human mononuclear cells were obtained by Ficoll density gradient centrifugation and cultured in M199 medium containing rh-VEGF (30 ng/ml), rh-b-FGF(6 ng/ml) and 20% NBCS for 8 days. The adhesive EPCs were sequentially harvested after 24 h synchronization and challenged with AGE-HSA (concentration range from 0 to 300 μg/ml) for 24 h and 200 μg/ml AGE-HSA (time range from 0 to 36 h). EPCs apoptosis and migration were determined, expressions of RAGE, phosphorylated ERK1/2, JNK and p38 mitogen-activated protein kinase (MAPK) of EPCs were quantified by fluorescent quantitation RT-PCR and Western-blot, effect of AGE-HSA on NF-κB activtiy was determined by EMSA (electrophoretic mobility shift assay) in the presence and absence of special MAPK pathways pathway inhibitors. Results  AGE-HSA upregulated the expression of RAGE, this effect could be significantly inhibited by p38 MAPK and ERK MAPK inhibitor, but not by JNK MAPK inhibitor. AGE-HSA also promoted EPCs apoptosis and inhibited EPCs migration and increased NF-κB activity, these effects could be significantly attenuated by the anti-RAGE neutralizing antibody as well as by p38 and ERK MAPK inhibitors. Conclusion  AGE-HSA could promote atherosclerosis by upregulating EPCs RAGE expressions and promoting EPCs apoptosis via p38, ERK MAPK pathways, activation of NF-κB might also play a role in this process. C. Sun and C. Liang contributed equally to this work. Returned for 1. Revision: 13 December 2007 1. Revision received: 20 February 2008 Returned for 2. Revision: 7 March 2008 2. Revision received: 9 June 2008     

槲皮素对D-半乳糖致衰老小鼠模型学习记忆及脑内炎症的影响

目的探讨槲皮素对D-半乳糖致衰老小鼠模型学习记忆能力及脑内炎症通路的影响。方法将昆明小鼠32只随机分为对照组(NC组)、模型组(M组)、Q1治疗组(Q1组)、Q2治疗组(Q2组),每组8只。M组、Q1组及Q2组小鼠皮下注射D-半乳糖100 mg/(kg·d)建立小鼠衰老模型,NC组给予等量生理盐水。Q1、Q2组造模同时给予不同剂量槲皮素5、10 mg/(kg·d)灌胃干预,NC组和M组给予相同剂量生理盐水灌胃处理,干预8周。Morris水迷宫评价逃避潜伏期、穿越平台次数及平台象限滞留时间,Western blotting检测小鼠脑内高级糖基化终末产物(AGEs)及其受体(RAGE)、核转录因子(NF-κB)和其下游炎症因子肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)、环氧化酶-2(COX-2)表达水平。采用SPSS 20.0统计软件对数据进行分析。组间比较采用完全随机设计的单因素方差分析或t检验。结果与NC组比较,M组小鼠逃避潜伏期延长、穿越平台次数及在平台所在象限滞留时间降低,脑内AGEs、RAGE、NF-κB及炎症因子TNF-α、IL-1β、COX-2水平显著升高(P0.05)。与M组比较,治疗组小鼠逃避潜伏期缩短、穿越平台次数及在平台所在象限滞留时间延长,脑内炎性因子水平减少(P0.05)。与Q1组比较,Q2组小鼠逃避潜伏期缩短、穿越平台次数及在平台所在象限滞留时间延长,RAGE、IL-1β和COX-2表达水平显著降低。结论槲皮素能够有效改善衰老小鼠学习记忆功能障碍,抑制AGEs/RAGE/NF-κB炎症通路,降低脑内炎性因子的生成,具有抗衰老潜力。