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.     

吡哆胺对动脉粥样硬化兔晚期糖基化终末产物及其受体的影响

目的观察吡哆胺对动脉粥样硬化兔晚期糖基化终末产物(AGEs)及其受体的影响。方法利用高脂饮食法诱导建立兔动脉粥样硬化模型。将新西兰白兔按随机数字表法随机分为正常对照组、动脉硬化组、吡哆胺小剂量组和吡哆胺大剂量组。正常对照组给予普通食物;动脉硬化组给予高脂饮食;吡哆胺小剂量组给予高脂饮食+吡哆胺100 mg/(kg·d);吡哆胺大剂量组给予高脂饮食+吡哆胺150 mg/(kg·d),共观察12周。实验12周末监测所有兔血糖、三酰甘油、总胆固醇、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C);应用酶联免疫吸附试验法检测血清AGEs水平;观察主动脉病理形态学改变;免疫组化方法检测主动脉AGEs受体(RAGE)含量,并进行各组间的比较。结果实验12周末,(1)与对照组比较,动脉硬化组兔三酰甘油、总胆固醇、LDL-C、HDL-C均明显增高(均P0.01),血糖无明显变化(P0.05);动脉硬化组的血清AGEs水平[(419±29)mg/L)]、动脉RAGE吸光度(0.88±0.14)及斑块面积[(67.4±5.8)%]均较对照组[分别为(141±11)mg/L、(0.19±0.04)及0%]明显增高(均P0.01);(2)与动脉硬化组相比,吡哆胺小剂量组和吡哆胺大剂量组兔三酰甘油、总胆固醇、LDL-C、HDL-C、血糖均无明显变化(均P0.05);吡哆胺小剂量组的血清AGEs水平[(278±22)mg/L]、动脉RAGE吸光度(0.43±0.06)及斑块面积[(43.2±2.4)%]和吡哆胺大剂量组的血清AGEs水平[(211±18)mg/L]、动脉RAGE吸光度(0.27±0.05)及斑块面积[(27.4±2.8)%]均较动脉硬化组明显减少(均P0.01);(3)吡哆胺大剂量组的血清AGEs水平、动脉RAGE吸光度及斑块面积较吡哆胺小剂量组低(均P0.01)。(4)主动脉病理形态学:显微镜下见动脉硬化组动脉内膜增厚,形成明显的粥样斑块;有大量的泡沫细胞聚集及较多的炎性细胞。吡哆胺小剂量组和吡哆胺大剂量组较动脉硬化组均有不同程度的减轻。结论吡哆胺能够抑制、减缓实验性高脂饮食兔的动脉粥样硬化形成,可抑制血清AGES的生成及动脉RAGE的表达。     

晚期糖基化终末产物受体在疾病发展进程中的作用

<正>Toth等〔1,2〕首次在胎牛肺内皮细胞中发现晚期糖基化终末产物受体(RAGE),学者们开始关注RAGE在加剧糖尿病病理损伤过程中的作用。研究者〔1,3⁶〕发现RAGE除与糖尿病及其并发症关系密切外,还参与肿瘤生长、神经系统疾病、心血管疾病、炎性反应等多种病理生理过程。本文将RAGE在各类疾病中的作用做一综述。     

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.     

晚期糖基化终末产物与纤维化

晚期糖基化终末产物形成增多是糖尿病的重要特征。目前多个研究显示，其在糖尿病并发症中的发生、发展起了重要作用。晚期糖基化终末产物能促进肾脏、血管、腹膜等组织纤维化。其促纤维化作用可通过直接修饰细胞外基质、促进细胞外基质分泌、促进致纤维化细胞因子的产生、促进间质细胞转化及抑制细胞外基质降解等环节实现。本文对晚期糖基化终末产物的促纤维化作用进行综述。     

晚期糖基化终末产物受体在特发性肺纤维化中的研究进展

由于病因不明，特发性肺纤维化(idiopathic pulmonary fibrosis, IPF)缺乏有效的干预措施。晚期糖基化终末产物受体(receptor for advanced glycation end products, RAGE)是免疫球蛋白受体超家族的成员，在肺脏中表达最多，有助于维持肺组织的动态稳定。其参与糖尿病肾纤维化和肝纤维化已有证明，多项研究也表明，RAGE与IPF有关。本文就RAGE与IPF的研究进展做一综述，以期为IPF的治疗提供一思路。     

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。     

晚期糖基化终末产物与骨质疏松症

骨质疏松的主要表现是低骨量和骨组织微结构退变,其发生的本质在于骨再造过程紊乱即骨吸收超过骨形成。骨吸收与骨形成分别与破骨细胞和成骨细胞的活动直接相关。目前研究发现众多激素、生长因子和细胞因子等参与均衡这两类细胞的数量和活性,影响骨代谢平衡,晚期糖基化终末产物也是目前其中研究较为广泛的因子之一。晚期糖基化终末产物随着年龄增长在体内积聚增多,通过直接或间接的作用导致骨代谢的失衡,出现骨质疏松。     

糖基化终末产物在糖尿病并发症中的作用

糖基化终末产物在糖尿病并发症中的作用［ＭｉｃｈａｅｌＢ．Ｄｉａｂｅｔｅｓ，１９９４，４３：８３６］糖尿病是一组病因和发病机制尚未完全阐明的内分泌代谢疾病，而以高血糖为其共同标志。近几年来，人们在研究高血糖的基础上，已形成了一个具有说服力的理论，即慢性...     

Inhibition of glutathione on vascular smooth muscle cell proliferation mediate by advanced glycation end products

Background To confirm the proliferation of vascular smooth muscle cell （VSMC） lead by advanced glycation end products （AGEs） and investigate weather the mechanism is work through MAPK pathway. To investigate weather the prolification of VSMC lead by AGEs can be inhibited by reduced glutathione（GSH） and what the mechanisam is. Methods VSMC of rats were isolated and cultivated, separated in 8 groups, each group contained 12 samples. Density of cell was 1×105 /mL in each sample, cultivated with AGEs at different concentrations and intervened with GSH at different concentrations. In order to determine the mechanism and interventional factors of VSMCs, sandwich ELISA method was used to test the concentration of P-P38 and MTT colorimetry was adopted to evaluate the amount of VSMC. Results 1.Effect of AGEs to the OD value of MTT in VSMC： with stimulation of AGEs, OD valued of P-P38 in VSMC increased simultaneously （P0.01）, their value were 0.43±0.15, 0.49±0.16, 0.48±0.19 [L/（g·cm）]. With the increase of the dose of AGEs, there were no difference between groups B, C of MTT OD value（P0.05）. 2.Effect of GSH to the OD value of MTT in VSMC stimulated by AGEs： OD value of MTT decreased with the increase of GSH concentration, their value were 0.347±0.102, 0.333±0.108, 0.285±0.080 [L/（g·cm）] respectively, decreased by 45%, 56%, 60%（P0.01）compared with value of AGEs control group. With the increasing of the dose of GSH, the MTT OD value had no difference between groups F, G and H （P0.05）. 3.Effect of AGEs to the OD value of P-P38 in VSMC： with stimulation of AGEs, OD valued of P-P38 in VSMC increased obviously （P0.01）, their value were 0.65±0.17, 0.85±0.26, 0.94±0.17 [L/（g·cm）]. With the increasing of the dose of AGEs, the P-P38 OD value increase simultaneously（P0.05）. 4.Effect of GSH on the OD value of P-P38 in VSMC stimulated by AGEs： OD value of P-P38 decreased with the increasing of GSH concentration, their value were 0.356±0.090, 0.281±0.070, 0.256±0.072 [L/（g·cm）] respectively, decreased by 45%, 56%, 60%（P0.01）compared with the value of control group. With the increasing of the dose of GSH, the P-P38 OD value between groups F, G and H were decreased gradually （P0.01）. Conclusions 1.AGEs has the function of inducing the proliferation of vascular SMC, the activation of the P-P38 MAPK signal pathway may be the mechanism of the proliferation of VSMC. 2.GSH can inhibit the proliferation of VSMC lead by AGEs, The P-P38-MAPK pathway is being blocked by GSH, which is the mechanism of inhibiting the proliferation of VSMC lead by AGEs.     

1-磷酸鞘氨醇受体1参与晚期糖基化终产物引起的血管平滑肌细胞增殖和迁移

目的观察1-磷酸鞘氨醇受体1(S1PR1)在晚期糖基化终产物(AGE)引起的血管平滑肌细胞增殖和迁移中的作用。方法培养人脐动脉平滑肌细胞(HUASMC),葡萄糖与牛血清白蛋白(BSA)孵育法获得AGE-BSA,分为对照组、BSA组和AGE-BSA组,采用CCK-8实验检测平滑肌细胞增殖能力,采用细胞划痕和Transwell实验检测平滑肌细胞迁移能力,并进一步观察BSA和AGE-BSA在有或无S1PR1拮抗剂VPC23019/激动剂SEW2871预处理后的细胞增殖和迁移。结果与对照组比较,BSA和AGE-BSA均能诱导HUASMC增殖和迁移,AGE-BSA的作用比BSA更加显著(P0.05);S1PR1拮抗剂VPC23019可以明显抑制BSA和AGE-BSA诱导的HUASMC增殖和迁移;S1PR1激动剂SEW2871本身就可以促进HUASMC增殖和迁移,并且进一步促进BSA诱导的HUASMC增殖和迁移,而对AGE-BSA诱导的HUASMC增殖和迁移没有进一步的促进作用。结论血浆白蛋白本身对平滑肌细胞的增殖具有促进作用,糖基化修饰的白蛋白这一作用更加明显;S1PR1的激活参与了BSA和AGE-BSA促进平滑肌细胞增殖和迁移,AGE-BSA对S1PR1的激活作用更加显著。     

Effects of advanced glycation end products on the proliferation and fibronectin production of smooth muscle cells

The aim of this study was to evaluate the effects of advanced glycation end-products (AGEs) on the proliferative activity and fibronectin production of smooth muscle cells (SMCs). AGE-bovine serum albumin (AGE-BSA) was prepared by incubation with D-glucose at 37 degrees C for 60 days. Cultured SMCs were obtained from explants isolated from porcine abdominal aorta and used between passages 3 and 10. The proliferative activity of SMCs was examined by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay and by incorporation of 3H-thymidine into DNA. Fibronectin production was assessed by competitive ELISA assay for both fibronectin secreted into the culture medium (M-FN) and cell-associated fibronectin (C-FN), i.e., both intra- and peri-cellular fibronectin. Theassay revealed that AGE-BSA did not produce any change in optical density (A570) of SMCs at concentrations of up to 20 microg/ml, but decreased that of SMCs at a concentration of 40 microg/ml. The addition of PDGF (5 ng/ml) induced an increase in 3H-thymidine incorporation into DNA of quiescent SMCs, while the addition of AGE-BSA (20 microg/ml) had no effect. In contrast, AGE-BSA significantly increased C-FN of SMCs (30.8+/-8.58 ng/microg TP), compared to unmodified BSA (16.5+/-4.19 ng/microg TP). However, no difference in M-FN levels was observed between cells treated with AGE-BSA and unmodified BSA. The addition of anti-transforming growth factor (TGF)-beta antibody restored the levels of C-FN in SMCs cultured in 20 microg/ml of AGE-BSA, suggesting that TGF-beta might act as an intermediate factor in AGE-induced fibronectin production by SMCs. Our results suggest that interaction of AGE-modified proteins with SMCs may play a role in the development of atherosclerosis in diabetic and non-diabetic patients.     

过氧化物酶体增殖物激活受体γ对糖基化终产物诱导大鼠血管平滑肌细胞增殖的作用

目的观察吡格列酮对糖基化终产物（AGEs）刺激下大鼠血管平滑肌细胞（VSMCs）增殖的作用及对过氧化物酶体增殖物激活受体γ（PPARγ）基因及蛋白表达水平的影响,探讨PPARγ在AGEs诱导VSMCs增殖中的作用。方法（1）MTY法观察不同浓度、不同时间的AGEs对VSMCs增殖的影响及吡格列酮（1．0、10、100μmol／L）与AGEs共孵育对VSMCs增殖的干预作用。（2）用半定量逆转录聚合酶链反应测定VSMCs中PPARγ mRNA的表达。（3）用Western blot法检测PPARγ的蛋白表达。结果AGEs作用导致VSMCs增殖,AGEs抑制PPARγ mRNA和蛋白表达水平,这种抑制作用随着AGEs干预的时间延长和浓度的增加而增强（P〈0．05）。PPARγ激活剂吡格列酮通过增加PPARγ的表达,抑制AGEs诱导的VSMCs增殖。结论PPARγ表达的下降可能是糖尿病易患动脉粥样硬化的重要原因之一。     

Mechanisms involved in the stimulatory effect of advanced glycation end products on growth of rat aortic smooth muscle cells

Hyperglycemia is an important cause of accelerated atherosclerosis in diabetic patients. We examined the effect of hyperglycemia and advanced glycation end products (AGE) on proliferation of rat aortic smooth muscle cells (SMC) in culture; in vivo, this event is believed to contribute importantly to atherogenesis in diabetes mellitus. Glucose itself dose-dependently inhibited thymidine uptake by SMC, but AGE increased thymidine uptake, suggesting that SMC proliferation is accelerated by AGE. To examine possible mechanisms for this effect, we studied nuclear factor-kappa B (NF-kappaB) activation and the tyrosine phosphorylation pathway; AGE stimulated NF-kappaB activity, but phosphorylation of the platelet-derived growth factor (PDGF) receptor was unchanged. In Chinese hamster ovary (CHO) cells overexpressing galectin-3, an AGE receptor related to atherosclerosis, AGE increased thymidine uptake. This suggests SMC proliferation is enhanced by AGE via galectin-3. As pathways involving AGE-galectin-3 interaction thus may be involved in macroangiopathy, AGE appears to be important to the role of SMC in accelerated atherosclerosis associated with diabetes mellitus.     

Association between serum levels of soluble receptor for advanced glycation end products and circulating advanced glycation end products in type 2 diabetes

Aims/hypothesis Activation of the receptor for advanced glycation end products (RAGE, also known as AGE-specific receptor [AGER]) has been implicated in the development of diabetic vascular complications. Blockade of RAGE using a soluble form of the receptor (sRAGE) suppressed vascular hyperpermeability and atherosclerosis in animal models. Since little is known about the regulation of endogenous sRAGE levels, we determined whether serum sRAGE is influenced by circulating AGEs and the severity of nephropathy in type 2 diabetic patients.Materials and methods We recruited 150 healthy control and 318 diabetic subjects. Diabetic subjects were subdivided into those with proteinuria, microalbuminuria or normoalbuminuria. Serum sRAGE was assayed by ELISA and serum AGEs by competitive ELISA using a polyclonal rabbit antiserum raised against AGE-RNase.Results Diabetic subjects had higher sRAGE (1,029.5 pg/ml [766.1–1,423.0] interquartile range vs 1,002.6 [726.5–1,345.3], p<0.05) and AGEs (4.07±1.13, SD, unit/ml vs 3.39±1.05, p<0.01) than controls. Proteinuric subjects had the highest sRAGE levels and there was a significant trend between the severity of nephropathy and sRAGE (p=0.01). In diabetic subjects, serum log(sRAGE) correlated with AGEs (r=0.27, p<0.001), log(plasma creatinine) (r=0.31, p<0.001), log(urine AER) (r=0.24, p<0.01) and log(triglycerides) (r=0.15, p<0.01). On stepwise linear regression analysis, AGEs and creatinine levels were the main independent determinants of sRAGE concentration.Conclusions/interpretation Serum sRAGE levels and circulating AGEs are associated with the severity of nephropathy in type 2 diabetic patients. Prospective studies are required to determine whether endogenous sRAGE potentially influences the development of diabetic vascular complications.     

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.     

晚期糖基化终产物及其受体在白细胞中表达与老年人精神障碍的关系

目的 探讨血液中晚期糖基化终产物(AGEs)及其受体(RAGE)表达水平与老年人精神障碍性疾病的关系. 方法 将观察对象分为健康对照组31例、阿尔茨海默病(AD)组36例、血管性痴呆组20例、脑血管病所致精神障碍组28例.以荧光分光光度法测定各组血清AGEs水平,以逆转录多聚酶链式反应测定RAGE mRNA水平. 结果 血清AGEs水平在AD组、血管性痴呆组和精神障碍组分别为(477.1±36.2)AU/ml、(512.6±33.2)AU/ml和(415.25±32.5)AU/ml,均明显高于健康对照组(357.4±28.2)AU/ml(F=3.77,P<0.05).RAGE mRNA水平(RAGE/b-actin)分别为1.12±0.34、1.27±0.41和1.18±0.42,亦高于健康对照组的0.92±0.37(F=4.07,P<0.01),但各疾病组间差异无统计学意义(F=0.979,P>0.05).白细胞中RAGE mRNA水平与血清AGEs呈正相关关系(r=0.442,P<0.01). 结论 AD、血管性痴呆、脑血管病所致精神障碍患者血中的AGEs及其受体RAGE mRNA水平均较同龄健康老年人明显升高,AGEs与RAGE的相互作用可能直接或间接参与了老年人精神障碍性疾病的病理变化.