晚期糖基化终产物对肾小球系膜细胞表达Fractalkine的诱导作用

目的探讨晚期糖基化终产物(AGE)对肾小球系膜细胞表达Fractalkine(Fkn)的影响。方法体外培养大鼠肾小球系膜细胞,实验设AGE组:加入AGE-BSA(100mg·L-1);对照组:加入牛血清清蛋白(BSA)(100mg·L-1);PDTC组:先加入PDTC100μmol·L-1孵育1h,再加入AGE-BSA(100mg·L-1);AGE抗体组:先加入抗AGE抗体(100mg·L-1IgG)孵育2h后,再加入AGE-BSA(100mg·L-1)。培养所需时间收集细胞,检测FknmRNA及蛋白表达,激光共聚焦显微镜检测NF-κB活化。结果AGE诱导体外培养的大鼠系膜细胞大量表达Fkn-mRNA及蛋白,PDTC和AGE抗体显著抑制AGE诱导系膜细胞表达FknmRNA及蛋白。经AGE刺激后NF-κB/P65迅速核转位,30min达高峰。结论AGE通过活化NF-κB诱导肾小球系膜细胞表达Fkn。     

糖和晚期糖基化终末产物对牛肾小球系膜细胞的影响

目的 研究比较高糖和晚期糖基化终产物(AGEs)在糖尿病肾病发病中的作用。方法 将牛血清白蛋白(BSA)和D葡萄糖在37℃培养箱内孵育60天制备AGE-BSA，采用MTT比色法，观察不同作用时程和不同浓度的高糖和AGEs-BSA对肾小球系膜细胞(GMC)增殖的影响。结果 高糖和AGEs的作用相似，在培养早期(24～48h)剌激GMC增殖，此后48～72h对GMC的增殖起抑制作用。结论 在糖尿病肾病的发病中AGEs的形成和高血糖起着同样重要的作用。     

糖基化终产物对人肾小球系膜细胞细胞外基质金属蛋白酶促进因子基因表达的影响

目的 探讨糖基化终产物(AGEs)对人肾小球系膜细胞(HMRC)细胞外基质金属蛋白酶诱导因子(EMMPRIN)基因表达的影响.方法 在培养的人肾系膜细胞(HRMC)中分别加入不同浓度AGEs干预24 h和同一浓度AGEs干预HRMC不同的时间点,以无血清培养基(DMEM)和相应浓度的牛血清白蛋白(BSA)为对照.RT-PCR法检测EMMPRIN mRNA的表达水平.结果 与对照组相比,经各浓度及各时间点AGEs干预后, HMRC的EMMPRIN mRNA水平与对照组相比有显著差异(P＜0.01),且随AGEs浓度以及干预时间增加,EMMPRIN mRNA水平也明显逐渐降低(P＜0.05).结论 EMMPRIN可能是AGEs所致糖尿病肾病的因素之一.     

西红花酸对晚期糖化终产物诱导内皮细胞晚期糖基化终产物受体表达的抑制作用

目的：研究西红花酸对晚期糖基化终产物（AGE）诱导牛内皮细胞（BEC）中晚期糖基化终产物受体（RAGE）mRNA表达的抑制作用,并探讨其可能机制。方法：不同浓度的西红花酸（1、0.1、0.01μmol/L）预孵BEC细胞12h后,用AGE（100mg/L）刺激细胞12h,RT-PCR法测定RAGEmRNA的表达水平;ELISA法测定细胞间黏附分子-1（ICAM-1）的表达;试剂盒分别检测胞外超氧阴离子和硫代巴比妥酸反应产物（TBARS）浓度;同时,还用2,7-二氯荧光素（DCFH）测定了胞内H2O2的浓度,并用罗丹明123（Rh123）荧光法及MTT法分别检测细胞线粒体膜电位（MMP）水平和其琥珀酸脱氢酶（MSDH）的活性。结果：与AGE模型组相比,西红花酸能显著抑制RAGE mRNA的表达（P〈0.05）,降低胞外超氧阴离子和TBARS（P〈0.01或P〈0.05）及胞内H2O2水平;结果还显示,西红花酸能提高细胞MMP水平和MSDH活性。对ICAM-1蛋白表达也有抑制作用,且呈时间和剂量依赖性。结论：西红花酸可能通过清除AGE与RAGE结合产生的活性氧（ROS）来抑制RAGE mRNA的高表达。提示西红花酸对糖尿病血管病变有潜在的治疗价值。     

西红花酸对糖尿病大鼠体内晚期糖基化终产物的形成及其受体表达的影响

目的:观察西红花酸对糖尿病(diabetic melli-tus,DM)大鼠晚期糖基化终产物(AGEs)的形成和受体(RAGE)蛋白表达的影响。方法:以链脲佐菌素诱导DM大鼠模型,并将DM大鼠随机分为DM模型组和西红花酸治疗组(50 mg.kg-1.d-1),另设正常组,给药21 d后,血糖仪测定大鼠空腹血糖;试剂盒分别测定AGEs中间产物即血清果糖胺(FMN)和糖化血红蛋白(GHb)的含量;荧光分光光度法测定主动脉及肠系膜血管床AGEs的水平;病理切片观察肠系膜动脉的变化;免疫组化法检测RAGE蛋白在肠系膜动脉中的表达。结果:西红花酸治疗后,对DM大鼠血糖值无明显影响;但FMN和GHb水平与模型组比明显下降;AGEs在主动脉和肠系膜血管床中沉积减少;肠系膜动脉血管损伤减轻;RAGE蛋白表达显著下降。结论:西红花酸可抑制蛋白质非酶糖化反应,减少AGEs及其中间产物的形成,下调RAGE蛋白表达,保护DM大鼠血管。     

细胞因子对体外培养大鼠肾小球及肾小球系膜细胞分泌TNF的影响

采用ＥＬＩＳＡ法，观察了正常大鼠肾小球及ＧＭＣ在体外培养期间分泌ＴＮＦ的变化规律及不同细胞因子对其分泌ＴＮＦ的影响。结果表明：体外培养的肾小球与ＧＭＣ具有分泌ＴＮＦ的功能，而且不同的时相ＴＮＦ分泌的量不等。ＩＬ－１对其分泌ＴＮＦ无影响。ＩＬ－６抑制肾小球分泌ＴＮＦ，但促进ＧＭＣ分泌ＴＮＦ。ＥＴ－１能明显促进ＴＮＦ的分泌，而且促进的幅度与其浓度成正比。     

晚期糖基化终产物对人肝癌细胞HepG2增殖的影响

目的探讨糖尿病晚期糖基化终产物(AGEs)对肝癌细胞HepG2增殖的影响及其机制。方法体外培养人肝癌细胞HepG2,以终浓度分别为100、200和400μg/ml的AGEs处理细胞24h,并设正常对照组进行比较。运用细胞计数试剂盒8研究AGEs对HepG2增殖的影响,流式细胞术检测细胞周期的改变,Western blot检测肝癌细胞抗凋亡基因表达。结果 AGEs呈浓度依赖性显著促进HepG2细胞增殖(P<0.05)。与对照组比较,200μg/ml AGEs干预24h后可以减少HepG2细胞G1期百分率,同时增加S期百分率(P<0.05)。AGEs可致细胞抗凋亡基因B细胞淋巴瘤-白血病2(Bcl-2)相关蛋白表达增加。结论 AGEs能促进HepG2细胞的增殖,其机制可能与上调Bcl-2相关蛋白表达,加速细胞G1期向S期转换相关。     

硫辛酸对高糖诱导的肾小球系膜细胞NLRP3炎症小体表达的影响

目的 观察高血糖对培养的人肾小球系膜细胞（HMC）中NLRP3炎症小体表达的影响,并探讨硫辛酸（LA）对上述过程的干预机制,以探寻糖尿病肾病（DN）发病新机制和防治新策略。方法 传代培养人HMC,根据不同的干预因素分为正常对照（NG）组、高糖（HG）组、LA组、HG+LA组。采用CCK-8方法分别检测不同浓度的LA对HMC活性的影响,流式细胞仪检测活性氧（ROS）水平,RT-PCR检测NLRP3炎症小体mRNA的表达,Western-blot检测LA对HMC中NLRP3炎症小体的蛋白表达的影响。结果 CCK-8结果显示,LA的最佳保护浓度为200μmol/l;流式细胞仪检测结果显示,HG组ROS表达水平高于NG组,差异有统计学意义（P<0.05）。RT-PCR及Westernblot检测结果显示,HG组NLRP3炎症小体表达高于NG组,差异有统计学意义（P<0.05）;加入LA后,NLRP3炎症小体的表达均下降,差异有统计学意义（P<0.05）。结论 高糖环境可促进人HMC的增殖,在一定浓度范围内,适当浓度的LA能抑制HMC的增殖;高血糖可通过氧化应激途径增加NLRP...     

鸡矢藤提取物对STZ致糖尿病小鼠肾脏的氧化应激作用和晚期糖基化终产物的影响

目的：研究鸡矢藤提取物（EPS）对链脲佐菌素（STZ）所致糖尿病肾病小鼠的疗效观察。方法：雄性昆明小鼠适应性喂养后尾静脉注射150 mg·kg^-1 STZ,72 h后检测小鼠空腹血糖（FBG）以建立糖尿病模型。糖尿病小鼠随机分为5组：模型对照组,二甲双胍阳性对照组,EPS低、中、高剂量组（2.5,5,10 g·kg^-1）。另设空白对照组。各组小鼠连续灌胃给药4周,空白和模型对照组给予等量生理盐水。末次给药后测定小鼠FBG,收集尿液,检测24 h尿蛋白含量;测定血清中肌酐（Cr）、尿素氮（BUN）和总胆固醇（TC）的含量;检测肾脏组织中丙二醛（MDA）含量,超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-Px）活性以及晚期糖基化终产物（AGE）水平;HE染色法观察肾脏病理学变化。结果：与模型对照组比较,EPS能显著降低糖尿病小鼠的FBG,并明显降低血清生化指标,降低肾脏组织中MDA、AGE含量和增强SOD、GSH-Px活性,改善肾小管空泡变性和肾小球萎缩。结论：鸡矢藤提取物能有效降低糖尿病肾病小鼠血糖,改善肾功能状态,对STZ所致糖尿病小鼠的肾脏保护作用可能与其能降低AGE的积聚、改善组织的氧化应激状态有关。     

晚期糖基化终产物的病理意义及其机制

晚期糖基化终产物 (AGEs)是体内蛋白质与糖在无酶条件下发生反应后的产物。大量实验表明 :AGEs与糖尿病、血管性疾病、衰老以及肾脏疾病等多种疾病密切相关。在这些疾病的发展过程中 ,AGEs发挥了重要作用。一方面 ,AGEs直接参与疾病的发生 ,影响细胞和组织功能 ,另外 ,它还通过与特异受体结合 ,来介导一系列病理反应。该文从AGEs的产生过程、作用机制以及病理意义等方面作一综述     

Advanced Glycation End Products and Diabetic Complications

During long standing hyperglycaemic state in diabetes mellitus, glucose forms covalent adducts with the plasma proteins through a non-enzymatic process known as glycation. Protein glycation and formation of advanced glycation end products (AGEs) play an important role in the pathogenesis of diabetic complications like retinopathy, nephropathy, neuropathy, cardiomyopathy along with some other diseases such as rheumatoid arthritis, osteoporosis and aging. Glycation of proteins interferes with their normal functions by disrupting molecular conformation, altering enzymatic activity, and interfering with receptor functioning. AGEs form intra- and extracellular cross linking not only with proteins, but with some other endogenous key molecules including lipids and nucleic acids to contribute in the development of diabetic complications. Recent studies suggest that AGEs interact with plasma membrane localized receptors for AGEs (RAGE) to alter intracellular signaling, gene expression, release of pro-inflammatory molecules and free radicals. The present review discusses the glycation of plasma proteins such as albumin, fibrinogen, globulins and collagen to form different types of AGEs. Furthermore, the role of AGEs in the pathogenesis of diabetic complications including retinopathy, cataract, neuropathy, nephropathy and cardiomyopathy is also discussed.     

二甲双胍联合辛伐他汀对高糖诱导的肾小球系膜细胞增殖的抑制作用

目的:观察二甲双胍联合辛伐他汀对高糖诱导肾小球系膜细胞增殖的抑制作用.方法:采用肾小球系膜细胞体外培养技术,筛选最佳葡萄糖浓度,在此浓度下,诱导肾小球系膜细胞增殖,在不同浓度二甲双胍联合辛伐他汀浓度,通过MTT法检测并观察不同时间,不同浓度下系膜细胞增殖情况.结果:与其他剂量比较,0.6g·L-1葡萄糖在48、72 h对肾小球系膜细胞增殖刺激作用较强,差异有统计学意义(P＜0.01),选0.6 g·L-1葡萄糖为最佳浓度.与高糖组比较,二甲双胍联合辛伐他汀高、中及低剂量组,均在48、72 h抑制肾小球系膜细胞生长(P＜0.05);其中二甲双胍联合辛伐他汀高剂量组的抑制较强,但与二甲双胍联合辛伐他汀中剂量组、低剂量组比较,差异不显著(P＞0.05).结论:二甲双胍联合辛伐他汀具有抑制肾小球系膜细胞增殖作用,联合用药可治疗糖尿病肾病.     

舒洛地特对高糖环境中大鼠肾小球系膜细胞CD36抗原表达的抑制作用研究

目的：观察舒洛地特对高糖培养基中大鼠肾小球系膜细胞CD36抗原表达的抑制作用,探讨舒洛地特对肾脏的保护作用。方法：培养大鼠肾小球系膜细胞24 h后,将培养的细胞分为对照组（C组,普通培养基,含5.6 mmol·L-1葡萄糖）,甘露醇组（M组,24.2 mmol·L-1甘露醇＋C组）,高糖组（H组,30 mmol·L-1高糖MEM培养基）、舒洛地特干预组（S组,H组＋1.0 LRU·ml-1舒洛地特）。培养24 h后,RT-PCR和Western blotting法检测各组CD36 mRNA及蛋白的表达。结果：对照组和甘露醇组CD36mRNA（0.24±0.07和0.21±0.06）及蛋白（0.26±0.08和0.22±0.07）的表达差异无统计学意义（P〉0.05）,高糖组CD36 mRNA（0.62±0.11和0.24±0.07）及蛋白（0.83±0.23和0.26±0.08）表达显著高于对照组,差异有统计学意义（P〈0.05）,舒洛地特干预组CD36 mRNA（0.36±0.13和0.62±0.11）及蛋白（0.42±0.15和0.83±0.23）表达显著低于高糖组,差异有统计学意义（P〈0.05）。结论：舒洛地特可抑制高糖环境中大鼠肾小球系膜细胞CD36抗原的表达,可能是舒洛地特发挥肾脏保护作用的机制之一。     

Uptake of Nanoparticles by Rat Glomerular Mesangial Cells in Vivo and in Vitro

Glomerular mesangial cells play a major role in the structure of capillary loops, generation of mediators of inflammation, and uptake of macromolecules. We demonstrate here that isobutylcyanoacrylate nanoparticles loaded with actinomycin D (ADNP) concentrate in rat mesangial cells in vitro and in vivo, as compared to the free drug (AD). In normal rats injected with 20 µg of ³H-ADNP or ³H-AD, the uptake ratios ³H-ADNP/³H-AD measured in whole kidneys at 30 and 120 min were 2.2 ± 1.0 and 2.3 ± 0.9, respectively. The same ratios calculated for isolated rat glomeruli and tubules, were 4.1 ± 0.5 and 0.8 ± 0.2 at 30 min, and 2.6 ± 0.5 and 0.6 ± 0.3 at 120 min, respectively. In the glomeruli, the absolute uptake of ³H-ADNP corresponded to 7.5 (30 min) and 1.8 (120 min) % I.D./100 mg of protein. In rats with experimental glomerulonephritis, the uptakes of ³H-ADNP and ³H-AD by the glomeruli were 6.9 and 4.0 times higher than in normal rats, respectively. In vitro experiments demonstrated up to 5 times higher uptake by glomerular mesangial cells than by epithelial cells. Uptake was maximum after 60 min, higher at 37°C than at 4°C, dependent on the presence of fresh serum and inhibited by cytochalasin-B. Drug targeting by nanoparticles is thus possible to renal cells involved in inflammatory processes, especially mesangial cells and macrophages. Nanoparticles could also be useful for lowering drug concentration in tubular cells, to reduce any tubular toxicity. Targetting of the mesangial cells is of particular interest for drugs such as corticosteroids capable of reducing glomerular inflammation in various pathological conditions.     

SYMPOSIUM: Experimental Biology 1995 Role of Mesangial Cell Ion Transport in Glomerular Physiology and Disease: REGULATION OF MESANGIAL CHLORIDE CHANNELS BY INSULIN AND GLUCOSE: ROLE IN DIABETIC NEPHROPATHY

• 1 In response to vasoactive peptides (e.g. angiotensin II (AngII), vasopressin, endothelin-1, platelet-activating factor), glomerular mesangial cell contraction is mediated through activation of a Ca²⁺-dependent Cl^? conductance that, in turn, promotes membrane depolarization and voltage-activated Ca²⁺ entry.
• 2 Using patch clamp technology, our laboratory was the first to characterize a candidate Ca²⁺-dependent, 4pS Cl^? channel that is stimulated by vasoactive peptides in cultured rat mesangial cells. In the absence of extracellular insulin, the activation of Cl^? channels by AngII is abolished. We find that Cl^? channel sensitivity to intracellular Ca²⁺ and the membrane density of AngII receptors is also dependent on the presence of insulin.
• 3 Our studies also show that high extracellular glucose interferes with mesangial cell IP₃ generation and Cl^? channel stimulation. Importantly, we find that the insulin-dependency of Cl^? channels occurs within the range of plasma insulin concentrations observed in normal, obese, hypertensive and diabetic humans (i.e. 1–100μU/mL). Similarly, normal regulation of Cl^? channel activity is also modulated by glucose concentrations commonly observed in the plasma of diabetic humans (5–30 mmol/L).
• 4 There is substantial evidence, both in diabetic humans and animal models, that the provision of insulin and improved glycaemic control corrects or prevents glomerular hyperfiltration. The requirement for normal insulin and glucose levels, for the proper regulation of the 4pS Cl^? channel, provides a mechanism for impaired Ca²⁺ uptake and contraction observed in glomerular mesangial cells in association with insulin deficiency and hyperglocaemia.

     

羟苯磺酸钙对糖尿病大鼠肾脏表达E-选择素的影响

目的探讨羟苯磺酸钙对肾小球E-选择素(E-selectin)表达的影响和对糖尿病肾病大鼠的保护作用。方法22只大鼠行左肾切除术后,取6只作为正常对照组,另外16只单次腹腔注射1%链脲佐菌素制备糖尿病大鼠模型。其中12只大鼠造模成功,并将其随机分成糖尿病对照组和羟苯磺酸钙治疗组各6只,羟苯磺酸钙治疗组灌胃给予羟苯磺酸钙100mg.kg-1.d-1,正常对照组和糖尿病对照组每天灌胃给予相同体积的纯化水。用免疫组化和Westernblot法检测12周后E-selectin表达的改变。结果与正常对照组比较,糖尿病对照组和羟苯磺酸钙治疗组E-selectin表达增加(P<0.01);而羟苯磺酸钙治疗组E-selectin表达显著低于糖尿病对照组(P<0.01)。结论羟苯磺酸钙可抑制糖尿病大鼠E-selectin的表达,延缓糖尿病肾病的发生、发展。     

Extract of Cassiae Semen and its major compound inhibit S100b-induced TGF-β1 and fibronectin expression in mouse glomerular mesangial cells

Non-enzymatic glycation reactions between reducing sugar and free reactive amino groups of protein lead to the formation of advanced glycation end products, which increase under conditions of aging or diabetes. A previous study showed that extracts of Cassiae Semen (CS), the seed of Cassia tora, had inhibitory activity on advanced glycation end products formation in vitro. To examine the pharmacological effects of a butanol-soluble extract of CS under conditions of diabetic nephropathy, we evaluated the expression of transforming growth factor-β1 (TGF-β1) and fibronectin, key mediators of diabetic nephropathy, in mouse glomerular mesangial cells cultured in the presence of S100b (a specific ligand for receptor of advanced glycation end products). CS inhibited S100b-induced TGF-β1 and fibronectin expression in mouse mesangial cells by suppressing activation of Smad2/3, extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK), and oxidative stress. Moreover, CS suppressed nuclear factor-kappa B (NF-κB) activation in S100b-stimulated mouse mesangial cells. To identify the active compounds of CS, three major compounds, rubrofusarin-6-O-β-d-gentiobioside (CS-A), toralactone-9-O-β-d-gentiobioside (CS-B), and cassiaside (CS-C), were tested in cells. Of these compounds, CS-A significantly decreased the expression of TGF-β1 and fibronectin and NF-κB DNA binding activity. These findings suggest that CS, especially CS-A, has potential as a preventive agent for advanced glycation end products-related diabetic complications.     

Therapeutic potential of resveratrol in diabetic complications: In vitro and in vivo studies

BackgroundVarious mechanisms with a complex integrating paradigm have been implicated in diabetic complications. The present study was aimed to evaluate the aldose reductase (AR) and advanced glycation end products (AGEs) inhibitory activity of resveratrol (RSV) and its potential in the treatment of diabetic complications such as cataract and nephropathy.MethodsRSV was studied for its inhibitory activity against rat lens AR (RLAR) and rat kidney AR (RKAR) in vitro along with its ability to inhibit formation of AGEs. Anticataract activity of RSV was demonstrated using sugar induced lens opacity model in isolated cattle lens. Furthermore the involvement of RSV in streptozotocin-induced diabetic nephropathy was investigated by assessing the key markers of kidney function along with the formation of AGEs. The potent AR inhibitor, fidarestat was as a standard.ResultsRSV exhibited inhibitory activity against RLAR and RKAR with IC₅₀ values of 4.99 μg/ml (21.9 μM) and 5.49 μg/ml (24.5 μM), respectively. It also showed a significant inhibition of AGEs formation in vitro. In sugar-induced lens opacity model, RSV displayed a significant protective effect preventing opacification and formation of polyols in cattle lens. RSV significantly improved glycaemic status and renal function in diabetic rats with a significant decrease in the formation of AGEs in the kidneys.ConclusionsThe results obtained in this study underline the potential of RSV as a possible therapeutic agent against long-term diabetic complications.