晚期糖基化终产物及其受体对大鼠阴茎海绵体组织中内皮素-1活性的影响

目的:通过观察大鼠阴茎海绵体组织中晚期糖基化终产物(AGEs)及其受体(RAGE)的变化对内皮素1(ET-1)活性的影响,探讨AGEs在糖尿病性勃起功能障碍(DMED)发生发展中的作用。方法:成年雄性SD大鼠60只,随机取40只用于制作糖尿病模型,造模后共27只大鼠成模,将其分为两组:糖尿病(DM)组15只和糖尿病+氨基胍给药(DM+AG)组12只;另20只大鼠平分为两组:正常对照(NC)组和正常对照+氨基胍给药(NC+AG)组;两组氨基胍(AG)给药组大鼠造模后即在其饮水中按1g/L剂量加入AG。饲养8周后取各组大鼠阴茎海绵体组织,一部分用于免疫组化法观察分析AGEs及其受体的分布和表达,剩余部分匀浆后检测AGE-肽(AGE-P)含量和ET-1活性。结果:DM组阴茎海绵体组织中AGEs和RAGE的表达、AGE-P含量及ET-1活性明显高于正常对照组(P<0.05);正常对照组与NC+AG组间比较在各项指标上则无明显差异(P>0.05)。结论:糖尿病状态下AGEs与RAGE的结合效应可以引起大鼠阴茎海绵体组织中ET-1活性的增强,从而促进DMED的发生发展。     

晚期糖基化终产物及其受体对大鼠阴茎海绵体组织中氧自由基代谢的影响

目的 通过观察大鼠阴茎海绵体组织中晚期糖基化终产物（AGEs）及其受体（RAGE）的变化对氧自由基代谢的影响，探讨AGEs在糖尿病性勃起功能障碍（DMED）发生发展中的作用。方法 成年雄性SD大鼠60只，随机取40只用于制作糖尿病模型，造模成功的大鼠分为两组：糖尿病（DM）组和糖尿病＋氨基胍给药（DM＋AG）组；另20只大鼠亦分为两组：正常对照（CO）组和正常对照＋氨基胍给药（CO＋AG）组；氨基胍（AG）给药组大鼠造模后即在其饮水中按1g／L剂量加入AG。饲养8周后取各组大鼠阴茎海绵体组织，一小段用于免疫组化观察分析AGEs及其受体的分布和表达，剩余部分匀浆后检测AGE-肽（AGE—P）含量、丙-醛（MDA）含量及超氧化物歧化酶（SOD）活性。结果 DM组阴茎海绵体组织中AGEs和RAGE的表达、AGE—P含量及MDA含量明显高于CO组（P〈0．05），而SOD活性则明显低于后者（P〈0．05），而AG则明显减少了DM大鼠阴茎海绵体组织中AGEs和RAGE表达、AGE—P及MDA的生成，增强了SOD活性；CO组与CO＋AG组间比较在各项指标上则无明显差异（P〉0．05）。结论 糖尿病状态下AGEs与RAGE的结合效应可以引起大鼠阴茎海绵体组织中氧自由基的产生增多，抗氧化能力的下降，从而促进DMED的发生发展。     

血液净化方式对终末期糖尿病肾病晚期糖基化终产物水平的影响

晚期糖基化终产物(AGEs)是蛋白质的氨基组、脂质和脂蛋白与糖的醛基组之间的非酶性糖基化／氧化终产物。正常人体内AGEs水平随年龄增长而缓慢增加，在糖尿病肾病(DN)和慢性肾衰((2RF)等病理状况下，循环中AGEs修饰蛋白的水平明显增高。它不仅参与了DN的发生和发展，而且当DN进入终末期时在体内聚集，加速了其并发症的发     

糖尿病大鼠肾组织中糖基化终产物受体基因表达的研究

目的 观察不同病程的糖尿病大鼠肾组织内糖基化终产物受体(RAG)mRNA的表达水平的改变。方法 采用逆转录聚合酶链式反应(RT-PCR)检测病程12周内RAGEmRNA水平。结果 诱发糖尿病大鼠2周时肾脏皮、髓质内RAGEmRNA表达无明显变化,4周后其表达不断地显著增加(P<0.05)。诱发8周、12周的糖尿病大鼠,其糖化血红蛋白(GHb)水平明显升高(P<0.001)。结论 糖尿病状态下,肾组织内RAGE的高表达可能与糖尿病肾病的发病有关,且可能是高血糖诱发AGEs形成的结果。     

循环晚期糖基化终产物的检测方法和评价

晚期糖基化终产物（AGE）是蛋白质的氨基组、脂质和脂蛋白与糖的醛基组之间的非酶性糖基化／氧化反应的终产物。反应早期生成可逆的Schiff碱，该早期产物经过结构重建，转化成较为稳定的amadori产物，而后再经过一系列化学重排和脱水反应，产生不可逆的晚期产物即ACE。正常人体内该反应进行得非常缓慢，通常只发生于某些转换率很低的蛋白质如基质蛋白。蛋白质一旦被AGE修饰，即丧失其生理功能，将通过巨噬细胞等细胞表面AGE受体而被摄取、降解、清除。因此，正常情况下AGE修饰蛋白作为一种信号参与了机体清除衰老组织以及结构重建的…     

氨基胍对糖尿病大鼠肾组织中内皮素及其受体基因表达的作用

目的探讨非酶糖化作用对糖尿病大鼠肾组织中内皮素及其受体基因表达的影响。方法采用逆转录－聚合酶链反应（ＲＴ－ＰＣＲ）技术，观察糖尿病大鼠肾皮质中内皮素及其受体基因表达的变化，以及氨基胍对其表达的影响。结果诱发糖尿病８周的大鼠肾皮质内ＥＴ－１及ＥＴ－Ａ受体的基因表达明显增加，ＥＴ－３ｍＲＮＡ水平与正常相比未见明显改变，但ＥＴ－Ｂ受体ｍＲＮＡ表达下降。氨基胍给药使糖尿病大鼠肾皮质内增加的ＥＴ－１及ＥＴ－Ａ受体ｍＲ－ＮＡ水平明显降低，同时使ＥＴ－３及ＥＴ－Ｂ受体ｍＲＮＡ表达明显增加。结论糖尿病状态下，ＥＴ－１、ＥＴ－３可能以不同的方式参与肾脏结构和功能的改变；氨基胍治疗能有效地调节糖尿病肾组织内异常的ＥＴ及其受体的基因表达，缓解肾脏损害。     

内质网应激对树突状细胞表面晚期糖基化终产物受体表达的影响

目的:晚期糖基化终产物受体(RAGE)与其配体结合在炎症及免疫反应中具有重要作用.本研究探讨内质网应激(ERS)在高迁移率族蛋白B1(HMGB1)诱导树突状细胞(DC)表面RAGE上调中的作用及意义.方法:分离正常BALB/c小鼠脾脏DC进行体外培养,给予HMGB1刺激后检测DC表面RAGE表达水平及细胞ERS相关分子...     

晚期糖基化终产物对足细胞整合素连接激酶的影响

目的:观察晚期糖基化终产物(AGEs)对足细胞整合素连接激酶的影响及可能机制。方法:不同浓度的AGEs干预小鼠足细胞,分别检测足细胞整合素连接激酶(ILK)的表达、足细胞黏附性和足细胞上清血管紧张素Ⅱ的浓度,然后预氯沙坦(100μmol)预处理足细胞后,观察足细胞ILK和黏附性的变化。结果:AGEs(80μg/ml)干预足细胞24 h可明显上调ILK的表达[(200±22)%vs.100%,P<0.05],降低足细胞的黏附性[(40±13)%vs.100%,P<0.05],同时升高细胞上清中血管紧张素Ⅱ的浓度[(11.2±0.8)vs.(7.0±0.7)pg/ml,P<0.05],而氯沙坦预处理可减轻AGEs介导的ILK的上调[(124±25)%vs.(200±22)%,P<0.05],足细胞的黏附性也明显改善[(75±13)%vs.(40±13)%,P<0.05]。结论:AGEs可能通过激活足细胞内的肾素-血管紧张素系统,上调足细胞ILK的表达,降低足细胞的黏附性。     

衰老对大鼠阴茎海绵体内皮细胞功能的影响

目的 :探讨衰老对大鼠阴茎海绵体内皮细胞功能的影响。　方法 :利用YH 4压力传感器分别检测了青龄(5个月 )和老龄 (2 0个月 )两组大鼠阴茎海绵体内压 (ICP)在乙酰胆碱 (Ach)、硝普钠 (SNP)和A2 3187作用下的变化 ;并测定了两组大鼠阴茎海绵体一氧化氮合酶 (NOS)的活性。　结果 :青龄组基础ICP为 (9.4± 2 .3)mmHg(1mmHg=0 .133kPa) ,老龄组为 (7.2± 1.7)mmHg,二者间差异无显著性 (P >0 .0 5 )。在浓度分别为 10 -6、10 -5、10 -4mol/L的Ach作用下 ,两组大鼠ICP值间差异均有显著性 (P <0 .0 1)。当Ach浓度为 10 -4mol/L时 ,两组大鼠ICP值达到最高 ,青龄组为 (5 4 .8± 4 .2 )mmHg ,老龄组为 (40 .3± 2 .8)mmHg。A2 3187(10 μmol/L)可以进一步提高老龄组ICP值 ,由(40 .3± 2 .8)mmHg上升到 (5 6 .2± 4 .1)mmHg ,两者间差异有显著性 (P <0 .0 1) ;青龄组提高不明显 ,由 (5 4 .8± 4 .2 )mmHg上升到 (5 5 .8± 4 .7)mmHg ,两者间差异无显著性 (P >0 .0 5 )。在SNP(10 -4mol/L)作用下青龄组ICP值为(5 8.9± 4 .7)mmHg ,老龄组为 (5 1.7± 5 .3)mmHg ,两者间差异无统计学意义 (P >0 .0 5 )。两组大鼠阴茎海绵体内NOS的活性差异无统计学意义 (P >0 .0 5 )。　结论 :大鼠阴茎海绵体内皮细胞对内皮细胞激动剂     

晚期糖基化终产物受体在糖尿病大鼠自体移植静脉中的表达及氨基胍的干预作用

目的 探讨晚期糖基化终产物受体（RAGE）在糖尿病大鼠自体移植静脉中的表达及氨基胍对其内膜增生的干预作用。方法 雄性SD大鼠60只，随机均分为氨基胍组、蒸馏水组及对照组，前2组行链脲佐菌素腹腔注射建立糖尿病模型，并分别用氨基胍或蒸馏水灌胃，对照组为未作处理的正常大鼠。3组均建立自体静脉移植模型后，于术后第7d及14d测定血清晚期糖基化终产物（AGE）含量，同时取自体静脉移植标本进行组织形态学观察，Westernblot和免疫组织化学染色方法检测RAGE及NF-KBp65的蛋白表达，半定量RT-PCR检测RAGE及NF—xBp65mRNA的表达。结果 术后第7d及14d，相对于对照组大鼠，蒸馏水组糖尿病大鼠自体移植静脉内膜增生加重，血清AGE含量增加，RAGE和NF—kB p65mRNA和蛋白表达增强，差异均有统计学意义（P〈0．05）；氨基胍组血清AGE含量、NF—kB p65蛋白和mRNA表达及内膜增生均较蒸馏水组减少或减轻（P〈0．05），与对照组相比差异无统计学意义（P〈0．05）。结论 糖尿病大鼠自体移植静脉RAGE表达增强，激活NF—kB，与移植静脉内膜增生关系密切；氨基胍抑制AGE的产生，可阻断AGE-RAGE结合，减轻内膜增生。     

A Receptor‐Based Bioadsorbent to Target Advanced Glycation End Products in Chronic Kidney Disease

The accumulation of advanced glycation end products (AGEs) has been reported to be a major contributor to chronic systemic inflammation. AGEs are not efficiently removed by hemodialysis or the kidney of a chronic kidney disease (CKD) patient. The goal of this study was to develop a receptor for AGEs (RAGE)‐based bioadsorbent device that was capable of removing endogenous AGEs from human blood. The extracellular domain of RAGE was immobilized onto agarose beads to generate the bioadsorbent. The efficacy of AGE removal from saline, serum, and whole blood; biological effects of AGE reduction; and hemocompatibility and stability of the bioadsorbent were investigated. The bioadsorbent bound AGE‐modified bovine serum albumin (AGE‐BSA) with a binding capacity of 0.73 ± 0.07 mg AGE‐BSA/mL bioadsorbent. The bioadsorbent significantly reduced the concentration of total AGEs in serum isolated from end‐stage kidney disease patients by 57%. AGE removal resulted in a significant reduction of vascular cell adhesion molecule‐1 expression in human endothelial cells and abolishment of osteoclast formation in osteoclast progenitor cells. A hollow fiber device loaded with bioadsorbent‐reduced endogenous AGEs from recirculated blood to 36% of baseline levels with no significant changes in total protein or albumin concentration. The bioadsorbent maintained AGE‐specific binding capacity after freeze‐drying and storage for 1 year. This approach provides the foundation for further development of soluble RAGE‐based extracorporeal therapies to selectively deplete serum AGEs from human blood and decrease inflammation in patients with diabetes and/or CKD.     

血液透析患者可溶性晚期糖基化终末产物受体与颈动脉粥样硬化的关系

目的：探讨血液透析患者可溶性晚期糖基化终末产物受体（sRAGE）与颈动脉粥样硬化之间的关系。方法：检测76名血透患者的sRAGE水平以及颈动脉粥样硬化超声指标,并选取35名年龄、性别相匹配的健康对照,对sRAGE、颈动脉粥样硬化超声指标及相关临床资料进行分析。结果：血液透析患者的sRAGE水平显著高于健康对照组（P〈0.01）。有糖尿病、冠心病史的血透患者的sRAGE水平较无糖尿病、冠心病史者低（均P〈0.05）。多元线性回归分析显示,sRAGE与颈动脉内-中膜厚度（IMT）呈负相关（P〈0.05）。结论：血透患者sRAGE水平与颈动脉粥样硬化呈负相关,提示sRAGE是血透患者的一种血管保护因子。     

The protective effect of aminoguanidine on erectile function in diabetic rats is not related to the timing of treatment

OBJECTIVE: To assess the accumulation of advanced glycation end products (AGEs) in streptozotocin (STZ)-induced diabetic rat cavernosal tissue, and to determine whether the protective effect of aminoguanidine (AG) on erectile function is related to the timing of treatment, as the accumulation of AGEs in the penis may be important in the pathogenesis of diabetes mellitus-induced erectile dysfunction, and prolonged treatment with AG (a selective AGE inhibitor), prevents erectile dysfunction in this situation. MATERIALS AND METHODS: Harlan Sprague-Dawley rats were divided into groups 1-4, i.e. age-matched controls; STZ diabetic rats (60 mg/kg intraperitoneal) given free access to water; STZ diabetic rats treated with AG (1 g/L per day in the drinking water) immediately after inducing diabetes; and STZ-diabetic rats treated with AG 1 month after inducing diabetes, respectively. Two months after inducing diabetes the intracavernosal pressure was measured after cavernosal nerve stimulation, and cavernosal AGE (5-hydroxy methyl furfural, 5-HMF) levels assessed. RESULTS: Cavernosal tissue 5-HMF levels from groups 2 and 4 were significantly higher than in group 1 (control). The expression of 5-HMF in group 3 was similar to that in group 1. Diabetic rats had significantly lower erectile function than controls, while groups 3 and 4 (treated with AG) had normal erectile function, as measured by cavernosal nerve stimulation. CONCLUSIONS: The effect of AG on AGE levels seems to be time-dependent; that the 1-month treatment with AG improved erectile function with no change in AGEs suggests that AG has protective effects on the penile vasculature through alternative pathways.     

Receptor for Advanced Glycation End Products in Donor Lungs Is Associated with Primary Graft Dysfunction After Lung Transplantation

Development of primary graft dysfunction (PGD) is associated with poor outcomes after transplantation. We hypothesized that Receptor for Advanced Glycation End‐products (RAGE) levels in donor lungs is associated with the development of PGD. Furthermore, we hypothesized that RAGE levels would be increased with PGD in recipients after transplantation. We measured RAGE in bronchoalveolar lavage fluid (BALf) from 25 donors and 34 recipients. RAGE was also detected in biopsies (transbronchial biopsy) from recipients with and without PGD. RAGE levels were significantly higher in donor lungs that subsequently developed sustained PGD versus transplanted lungs that did not display PGD. Donor RAGE level was a predictor of recipient PGD (odds ratio = 1.768 per 0.25 ng/mL increase in donor RAGE level). In addition, RAGE levels remained high for 14 days in those recipients that developed severe graft dysfunction. Recipients may be at higher risk for developing PGD if they receive transplanted organs that have higher levels of soluble RAGE prior to explantation. Moreover, the clinical and pathologic abnormalities associated with PGD posttransplantation are associated with increased RAGE expression. These findings also raise the possibility that targeting the RAGE signaling pathway could be a novel strategy for treatment and/or prevention of PGD.     

Advanced Glycation End Products in Hemodialyzed Patients with Diabetes Mellitus Correlate with Leptin and Leptin/Body Fat Ratio

Advanced glycation end products (AGEs) and other carbonyl and oxidative stress compounds are supposed to play a critical role in the pathogenesis of several diseases and their complications, i.e., diabetes mellitus, diabetic retinopathy, atherosclerosis, and chronic renal failure. In the present investigation, we were interested in the relationship of AGEs in plasma to other prominent factors in the patients on chronic hemodialysis treatment—27 patients with diabetes mellitus, 35 patients without diabetes mellitus. AGE-group reactivity was estimated using a spectrofluorometric method (excitation 350 nm, emission 430 nm) and is expressed in arbitrary units (AU). We found significantly higher AGEs levels in diabetics than in non-diabetics on regular hemodialysis treatment both before (2.7 ± 0.7 × 10⁴ AU vs. 2.2 ± 0.6 × 10⁴ AU, p<0.001) and after the dialysis session (2.3 ± 0.5 × 10⁴ AU vs. 1.8 ± 0.7 × 10⁴ AU, p<0.005). AGEs were significantly reduced during hemodialysis in both groups of patients—by 15.4 % in the diabetic go (p<0.001) and by 17.3% in non-diabetics (p<0.005). In the patients with diabetes mellitus, AGEs did not correlate with parameters of the glucose metabolism correction (blood glucose, HbA1c). We observed a significant correlation between AGEs and leptin (r = 0.48, p < 0.05) as well as the leptin/body fat ratio (r = 0.56, p < 0.05) only in hemodialyzed patients with diabetes mellitus. These findings suggest more detailed studies to identify the molecular links between carbonyl stress, i.e., advanced glycation end products, and leptin metabolism, sign of microinflammation and hypertension.     

Advanced glycation end products in degenerative nucleus pulposus with diabetes

Diabetes mellitus (DM) has been clinically proved as a risk factor of disc degeneration, and the accumulation of advanced glycation end products (AGEs) is known to be potentially involved in diabetes. The purpose of this study is to investigate the effect of AGEs in the degeneration process of diabetic nucleus pulposus (NP) in rats and humans. Diabetic NP cells from rat coccygeal discs were treated with different concentrations of AGEs (0, 50, and 100 µg/ml) for 3 days, and mRNA expressions of MMP‐2 and RAGE were measured by real‐time RT‐PCR. In addition, conditioned medium from NP cells was used to analyze protein expression of MMP‐2 activity and ERK by gelatin zymography and Western blot. These experiments were repeated using human intervertebral disc samples. The immunohistochemical expression of AGEs was significantly increased in diabetic discs. In response to AGEs, an increase of MMP‐2, RAGE, and ERK at both mRNA and protein expression levels was observed in diabetic NP cells. The findings suggest that AGEs and DM are associated with disc degeneration in both species. Hyperglycemia in diabetes enhances the accumulation of AGEs in the NP and triggers disc degeneration. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:238–244, 2014.     

Skin Autofluorescence,a Measure of Cumulative Metabolic Stress and Advanced Glycation End Products,Decreases During the Summer in Dialysis Patients

Tissue advanced glycation end products (AGEs) are a measure of cumulative metabolic and oxidative stress and cytokine‐driven inflammatory reactions. AGEs are thought to contribute to the cardiovascular complications of hemodialysis (HD) patients. Skin autofluorescence (SAF) is related to the tissue accumulation of AGEs and rises with age. SAF is one of the strongest prognostic markers of mortality in these patients. The content of AGEs is high in barbecue food. Due to the location in northern Sweden, there is a short intense barbecue season between June and August. The aim of this study was to investigate if seasonal variations in SAF exist in HD patients, especially during the barbecue season. SAF was measured noninvasively with an AGE Reader in 34 HD‐patients (15 of those with diabetes mellitus, DM). Each time the median of three measures were used. Skin‐AF was measured before and after each one HD at the end of February and May in 31 patients (22 men/9 women); the end of May and August in 28 (20 m/8 w); the end of August and March in 25 (19 m/6 w). Paired statistical analyses were performed during all four periods (n = 23, 17 m/6 w); as was HbA1c of those with DM. There was at a median 5.6% increase in skin‐AF during the winter period (February–May, P = 0.004) and a 10.6% decrease in the skin‐AF during the summer (May–August, P < 0.001). HbA1c in the DM rose during the summer (P = 0.013). In conclusion, skin‐AF decreased significantly during the summer. Future studies should look for favorable factors that prevent skin‐AF and subsequently cardiovascular diseases.