硫氧还蛋白相互作用蛋白介导胰岛β细胞凋亡及功能障碍研究进展

硫氧还蛋白相互作用蛋白(TXNIP)不仅与细胞的氧化还原状态密切相关,在胰岛β细胞功能障碍和细胞凋亡中也扮演了重要角色。高糖通过招募碳水化合物反应元件结合蛋白(ChREBP)到TXNIP的启动子,ChREBP与组蛋白乙酰转移酶p300相互作用,引起TXNIP的转录,TXNIP介导高糖诱发的氧化应激、内质网应激、NOD样受体3炎症小体激活、凋亡和自噬障碍等。可通过诱导微小RNA-204的表达下调鸟类Maf A蛋白哺乳动物同系物而抑制胰岛素基因转录,抑制胰岛素信号转导途径,进而抑制葡萄糖刺激的胰岛素分泌;TXNIP通过抑制硫氧还蛋白系统影响细胞的生存,同时还是介导细胞线粒体凋亡和内质网应激凋亡途径的枢纽分子。抑制TXNIP可能是一个阻止糖尿病进程的有效靶点。本文就TXNIP在胰岛细胞凋亡和胰岛功能障碍方面的相关研究进行回顾和总结分析。     

Txnip与胰腺β细胞功能障碍和细胞凋亡

硫氧还蛋白相互作用蛋白（thioredoxin-interacting protein,Txnip）可通过与硫氧还蛋白（thioredoxin,Trx）相互作用产生二硫键抑制其还原酶活性,在调节细胞氧化还原平衡中起重要作用。近年来,Txnip因为在葡萄糖和脂肪代谢中的重要调节作用,以及与胰腺β细胞功能障碍和细胞凋亡的密切关系而受到广泛关注,Txnip也被认为是2型糖尿病防治的一个新的明星分子。本文拟就国内外有关Txnip与胰腺β细胞功能障碍和细胞凋亡的相关研究进展做一综述。     

硫氧还蛋白相互作用蛋白与2型糖尿病及胰岛素抵抗的相关性

目的 探讨硫氧还蛋白相互作用蛋白(TXNIP)与2型糖尿病(T2DM)及胰岛素抵抗的关系.方法 采用ELISA法检测T2DM组(A组,54例)及正常对照组(B组,30例)患者血清TXNIP水平,同时检测糖化血红蛋白(HbAlc)、空腹血糖(FPG)、胰岛素(FINS)及血脂.结果 A组血清TXNIP水平显著高于B组(P＜0.05).TXNIP与FPG、HbAlc、胰岛素抵抗指数(HOMA-IR)呈显著正相关(P＜0.01); HbAlc和HOMA-IR是TXNIP的独立影响因素.结论 TXNIP可能参与了T2DM及胰岛素抵抗的病理生理过程.     

硫氧还蛋白的生物学及其与阿尔茨海默病和帕金森病的关系

硫氧还蛋白(thioredoxin，Trx)是一种具有氧化还原活性的小分子蛋白质，具有抗氧化、抗凋亡、调节转录因子活性等功能，在氧化还原调节和细胞信号转导中发挥重要作用。本文对哺乳动物的Trx及其与阿尔茨海默病(AD)和帕金森病(PD)的关系的研究进展进行综述。基于Trx的神经保护活性，增加Trx的表达可望成为AD和PD防治的新靶点。     

靶向硫氧还蛋白系统抗肿瘤药物的研究进展

硫氧还蛋白（Trx）/硫氧还蛋白还原酶（TrxR）在许多人原发性肿瘤中和肿瘤病人的血样中是高表达的.其在促进肿瘤细胞增殖、抑制细胞凋亡、促进肿瘤耐药发生等事件中起到关键的推动作用,通过化疗药物抑制TrxR的活性已成为有效的癌症靶向治疗策略.国内外都开展了硫氧还蛋白系统抑制剂的探索工作,目前国际上进入临床研究的硫氧还蛋白系统的靶向药物只有三种,本文针对临床在研的这三种药物进行总结,以期开发出新型更高效的抗肿瘤新药.     

咯利普兰对H_2O_2致PC12细胞氧化应激损伤的保护作用

目的探讨PDE4抑制剂咯利普兰(rolipram)对H2O2致PC12细胞氧化应激损伤的保护作用及其作用机制。方法以H2O2损伤PC12细胞为氧化应激损伤模型,MTT法检测细胞存活率;碘化丙啶(Propidium iodide,PI)染色流式细胞术检测细胞周期变化;化学比色法测定细胞清除羟自由基(·OH)和超氧阴离子自由基(O2·)的能力;以及培养上清液中的丙二醛(MDA)、谷胱甘肽(GSH)和一氧化氮(NO)含量、超氧化物歧化酶(SOD)活性。Western blot和Real-time RT-PCR检测细胞内硫氧还蛋白(Trx)和诱导型一氧化氮合酶(iNOS)的表达。结果咯利普兰能明显提高H2O2损伤的PC12细胞存活率,恢复细胞增殖;提高细胞清除·OH和O2·的能力;降低MDA和NO含量,提高GSH含量和SOD活性;使Trx蛋白和mRNA表达增加,同时下调iNOS蛋白和mRNA表达。结论咯利普兰对H2O2致PC12细胞损伤具有保护作用,其作用机制可能与提高PC12细胞的抗氧化能力相关。     

血清TXNIP在2型糖尿病视网膜病变患者中的表达及其与氧化应激的关系

目的 探讨血清硫氧还蛋白互作蛋白（TXNIP）在2型糖尿病视网膜病变（DR）患者中的表达及其与氧化应 激的关系。方法 选取DR患者（DR组）82例,根据疾病严重程度将其分为增生性糖尿病视网膜病变（PDR）组（42 例）以及非增生性糖尿病视网膜病变（NPDR）组（40例）。另选取健康志愿者（对照组）50例以及单纯2型糖尿病患者 （糖尿病组）50例。收集所有研究对象的一般资料。采用酶联免疫吸附试验检测血清TXNIP水平,黄嘌呤氧化酶法 检测超氧化物歧化酶（SOD）水平,二硫代二硝基苯甲酸比色法测定还原型谷胱甘肽（GSH）水平,硫代巴比妥法检测 血清丙二醛（MDA）水平。全自动生化分析仪测定糖化血红蛋白（HbA1c）、空腹血糖（FPG）、三酰甘油（TG）和总胆固 醇（TC）。结果 与对照组比较,糖尿病组和DR组TG、TC升高（P＜0.05）,但后2组间差异无统计学意义。对照组、 糖尿病组及 DR 组 HbA1c、FPG、MDA 及 TXNIP 依次增加,而 SOD 和 GSH 依次降低（均 P＜0.05）。与 PDR 组比较, NPDR组MDA和TXNIP降低,而SOD和GSH升高（P＜0.05）;2组HbA1c、FPG、TG及TC差异无统计学意义。较高水 平的 MDA 和 TXNIP 是 DR 患者发生 PDR 的危险因素,而较高水平的 SOD 和 GSH 则是保护因素（P＜0.05）。血清 TXNIP诊断DR的ROC曲线下面积为0.803（95%CI：0.730~0.875）,当截断值取3.01 μg/L时,敏感度、特异度和约登指 数分别为 53.66%、94.00% 和 0.477。结论 TXNIP 在 DR 患者血清中呈异常高表达,是 DR 患者发生 PDR 的危险因 素,且可能通过调节氧化应激反应促进疾病的发生、发展,对临床诊断DR有一定辅助价值。     

黄芩对实验性帕金森模型大鼠的保护作用

目的:研究黄芩对鱼藤酮所致帕金森(PD)模型大鼠的保护作用。方法:Wistar大鼠每日颈、背部皮下注射鱼藤酮葵花油乳化液制备PD大鼠模型;阳性组及不同剂量药物组在每日注射鱼藤酮之前1小时灌胃给药。ELISA法检测大鼠脑硫氧还蛋白(Trx);荧光探针法检测纹状体活性氧(ROS);分光光度法检测纹状体谷胱甘肽(GSH)、黑质丙二醛(MDA)含量。结果:造模后模型组大鼠出现一定程度的行为学变化,模型组Trx含量明显低于空白组、阳性组和低剂量组,药物可以一定程度上抑制氧化应激反应。结论:黄芩可以提高帕金森大鼠脑内Trx的表达,对鱼藤酮所致帕金森模型大鼠具有保护作用,这种作用可能与Trx相关。     

普拉克索下调TXNIP表达对氧糖剥夺/再灌注心肌细胞p38/JNK通路的作用研究

目的 探究普拉克索对氧糖剥夺/再灌注(OGD/R)心肌细胞的作用及其可能的作用机制。方法 CCK-8检测细胞活力；试剂盒检测LDH和CK-MB活性、MDA和SOD含量；流式细胞术检测ROS产生和细胞凋亡；Western blot检测硫氧还蛋白相互作用蛋白(TXNIP)、p-p38、p38、p-JNK和JNK蛋白表达；qRT-PCR检测TXNIP mRNA表达。结果 与对照组比较，OGD/R组心肌细胞活力、SOD含量明显降低(P<0.05),而LDH活性、CK-MB活性、ROS产生、MDA含量和细胞凋亡率明显升高(P<0.05),TXNIP、p-p38/p38和p-JNK/JNK蛋白表达明显升高(P<0.05);与OGD/R组比较，Pra-50μmol/L组和Pra-100μmol/L组心肌细胞活力、SOD含量明显升高(P<0.05),而LDH活性、CK-MB活性、ROS产生、MDA含量和细胞凋亡率明显降低(P<0.05),TXNIP、p-p38/p38和p-JNK/JNK蛋白表达明显降低(P<0.05),且普拉克索的作用呈剂量依赖性；与Pra-100...     

番茄红素对肾脏缺血再灌注损伤大鼠的保护作用

目的 探究番茄红素(LP)通过抑制硫氧还蛋白相互作用蛋白/NOD样受体热蛋白结构域相关蛋白3(TXNIP∕NLRP3)信号通路保护大鼠肾脏缺血再灌注损伤(IRI).方法 100只大鼠随机分为对照组(n=25)、模型组(n=25)及低剂量实验组(n=25)、高剂量实验组(n=25).模型组及低/高剂量实验组均采用右侧肾切...     

Autophagy in toxicology: self‐consumption in times of stress and plenty

Autophagy is a critical cellular process orchestrating the lysosomal degradation of cellular components in order to maintain cellular homeostasis and respond to cellular stress. A growing research effort over the last decade has proven autophagy to be essential for constitutive protein and organelle turnover, for embryonic/neonatal survival and for cell survival during conditions of environmental stress. Emphasizing its biological importance, dysfunctional autophagy contributes to a diverse set of human diseases. Cellular stress induced by xenobiotic exposure typifies environmental stress, and can result in the induction of autophagy as a cytoprotective mechanism. An increasing number of xenobiotics are notable for their ability to modulate the induction or the rate of autophagy. The role of autophagy in normal cellular homeostasis, the intricate relationship between cellular stress and the induction of autophagy, and the identification of specific xenobiotics capable of modulating autophagy, point to the importance of the autophagic process in toxicology. This review will summarize the importance of autophagy and its role in cellular response to stress, including examples in which consideration of autophagy has contributed to a more complete understanding of toxicant‐perturbed systems. Copyright © 2012 John Wiley & Sons, Ltd.     

Different responses to surgical stress between extra domain A+ and plasma fibronectins

1. Fibronectins (FN) are believed to have a role in haemorheological perturbation associated with tissue damage. Fibronectins exist in two antigenically related forms, plasma (p) and cellular fibronectin, which has the extra domain sequences A (EDA) or B (EDB). The present study was designed to determine changes in plasma p-FN and EDA + FN under different types of surgical stress. 2. Sixty-two patients were divided into three groups: (i) group A, 33 patients undergoing hepato-pancreato-biliary surgery; (ii) group B, 19 patients undergoing laparoscopic cholecystectomy; and (iii) group C, 10 patients with postoperative complications. Plasma FN and EDA + FN levels were measured in these patients undergoing different types of surgical operation and either with or without liver cirrhosis using an enzyme-linked immunosorbent assay. 3. After surgery, a significant decrease in p-FN levels and a significant increase in EDA + FN levels was observed in all patient group compared with pre-operative levels. The duration of increased EDA + FN levels, but not p-FN levels, in group A patients was significantly longer than in group B patients. Although changes in p-FN levels between patients with and without liver cirrhosis were significantly different, there were no significant differences in the EDA + FN levels between these two patient groups. 4. In conclusions, EDA + FN and p-FN levels were found to exhibit opposite responses to surgical stress. Furthermore, with greater surgical stress, greater increases in EDA + FN levels were seen. The presence of liver cirrhosis had no significant effect on EDA + FN levels during the perioperative period; however, p-FN levels were significantly affected. 5. Thus, it is suggested that plasma EDA + FN levels reflect the magnitude of surgical stress more closely than do p-FN levels.     

促甲状腺素释放激素对应激小鼠免疫功能的影响

促甲状腺素释放激素对应激小鼠免疫功能的影响吴敏毓，汤斌，曲卫敏（皖南医学院微生物学教研室，芜湖２４１００１）促甲状腺素释放激素（ＴＲＨ）是丘脑下部分泌的三肽激素，能刺激垂体释放促甲状腺素（ＴＳＨ），进而促使甲状腺合成与分泌三碘甲状腺原氨酸（Ｔ３）和甲...     

Surface charge-specific cytotoxicity and cellular uptake of tri-block copolymer nanoparticles

Abstract

A series of monodisperse (45 ± 5 nm) fluorescent nanoparticles from tri-block copolymers (polymeric nanoparticles (PNPs)) bearing different surface charges were synthesised and investigated for cytotoxicity in NR8383 and Caco-2 cells. The positive PNPs were more cytotoxic and induced a higher intracellular reactive oxygen species production than the neutral and negative ones. The cytotoxicity of positive PNPs with quaternary ammonium groups decreased with increasing steric bulk. The intracellular uptake and cellular interactions of these different PNPs were also tested in NR8383 cells by confocal laser scanning microscopy, which revealed higher uptake for positive than for negative PNPs. Also positive PNPs were found to interact much more with cell membranes, whereas the negative PNPs were internalised mainly by lysosomal endocytosis. Uptake of positive PNPs decreased with increasing steric bulk around the positive charge. A surface charge-specific interaction of clathrin for positive PNPs and caveolin receptors for negative PNPs was observed. These findings confirm that surface charge is important for the cytotoxicity of these PNPs, while they additionally point to considerable additional effects of the steric shielding around positive charges on PNP cytotoxicity.     

右美托咪定对肺癌根治术患者围术期氧化应激反应及细胞免疫功能的影响

目的：观察右美托咪定对胸腔镜肺癌根治术患者围术期氧化应激反应及免疫功能的影响。方法：全麻单肺通气行胸腔镜肺癌根治术患者100例;随机分为右美托咪定组（A组）和对照组（B组）,每组50例。A组麻醉诱导前20 min静注右美托咪定负荷量1 μg·kg^-1,15 min输完,随后给予维持量0.5 μg ·kg^-1 ·h^-1,手术结束前20 min时停药;B组相同方法输注等量生理盐水;在T₀（麻醉诱导前30 min）、T₁（完成手术时）、T₂（手术后12 h）、T₃（手术后24 h）时采集静脉血,检测丙二醛（MDA）浓度和超氧化物歧化酶（SOD）的水平,并分别测定CD₃⁺、CD₄⁺、CD₈⁺的表达水平和NK细胞的含量,计算CD₄⁺/CD₈⁺比值。结果：与T₀相比,T₁-T₃时间点两组血清SOD活性降低,MDA浓度升高（P<0.05）;CD₃⁺、CD₄⁺含量以及CD₄⁺/CD₈⁺比值、NK细胞水平均降低（P<0.05）。2组比较,T₁-T₃时间点A组血清SOD活性升高、MDA浓度降低得更明显（P<0.05）。B组CD₃⁺、CD₄⁺含量以及CD₄⁺/CD₈⁺比值、NK细胞水平降低得更显著（P<0.05）。结论：右美托咪定能够有效抑制围手术期诱发的应激反应,减轻胸腔镜肺癌根治术后患者的免疫抑制。     

黄芪甲苷对阿德福韦酯致肾损伤的保护作用和机制研究

目的：本实验旨在研究黄芪甲苷（astragaloside IV,As）对阿德福韦酯（adefovir dipivoxil,Adv）致肾损伤的保护作用,探究其可能的作用机制。方法：将50只SD雄性大鼠按数字表法随机分为正常组（normal）,Adv肾损伤组（30 mg·kg^-1·d^-1）,As低、中、高剂量干预组（10,20,30 mg·kg^-1·d^-1）。通过测定血浆生化指标比较各组肾功能差异;Masson染色评价各组肾小管上皮细胞病理学改变;利用UHPLC-MS代谢组学方法检测各组大鼠血浆内源性代谢物的变化,筛选出差异代谢物。结果：与正常组相比,Adv组肌酐值显著升高,肾损伤严重。而As可显著降低肌酐值和改善肾小管上皮细胞病理学形态,有效干预Adv致肾损伤。Adv组大鼠血浆共发现28个差异代谢物,As可显著逆转16个代谢物的变化。主要涉及与能量代谢相关的苯丙氨酸、酪氨酸和色氨酸代谢通路、泛醌和其他萜烯-醌代谢通路,与氧化应激相关的谷胱甘肽代谢通路。结论：本研究提示As保护Adv致肾损伤的机制与改善细胞供能,减少氧化应激对细胞的损害密切相关。本研究为阿德福韦酯治疗慢性乙型肝炎（CHB）时利用黄芪作为减毒增效的治疗策略提供了基础依据。     

Cellular interactions of therapeutically delivered nanoparticles

Introduction: Nanoparticles (NPs) are used extensively in drug delivery. They are administered through various routes in the host, and their uptake by the cellular environment has been observed in several pathways. After uptake, NPs interact with cells to different extents, depending on their size, shape, surface properties, ligands tagged to the surface and tumor architecture. Complete understanding of such cellular uptake mechanisms and interactions of NPs is important for their effective use in drug delivery.

Areas covered: This article describes the various cellular pathways for NP uptake, and the factors affecting NP uptake and interactions with cells. Understanding these two important aspects will help in the future design of NPs for effective and targeted drug delivery.

Expert opinion: Surface charge and ligands tagged on the surface of NPs play a critical role in their uptake and interaction with cells; so surface modifications of NPs can offer increased drug delivery effectiveness, for example, the coupling of ligands on the surface of NPs can increase cellular binding, and NPs in biological fluids can be coated with proteins and as such can exert biological effects. All of the factors affecting NP uptake need to be investigated thoroughly before interpreting any NP–cellular interactions.     

Models of hepatotoxicity and the underlying cellular,biochemical and immunological mechanism(s): A critical discussion

Liver is a primary organ involved in biotransformation of food and drugs. Hepatic diseases are a major worldwide problem. Hepatic disorders are mainly caused by toxic chemicals (alcohol), xenobiotics (carbon tetrachloride, chlorinated hydrocarbons and gases CO₂ and O₂) anticancer (azathioprine, doxorubicin, cisplatin), immunosuppressant (cyclosporine), analgesic anti-inflammatory (paracetamol, thioacetamide), anti-tubercular (isoniazid, rifampicin) drugs, biologicals (Bacillus-Calmette–Guerin vaccine), radiations (gamma radiations), heavy metals (cadmium, arsenic), mycotoxin (aflatoxin), galactosamine, lipopolysaccharides, etc. Various risk factors for hepatic injury include concomitant hepatic diseases, age, gender, alcoholism, nutrition and genetic polymorphisms of cytochrome P₄₅₀ enzymes have also been emphasized.The present review enumerates various in vivo animal models and in vitro methods of hepatic injury using diverse toxicants, their probable metabolic pathways, and numerous biochemical changes viz. serum biomarkers enzymes, liver function, oxidative stress associated events like free radicals formation, lipid peroxidation, enzyme antioxidants and participation of cytokines (tumour necrosis factor-α, transforming growth factor-β, tumour necrosis factor-related apoptosis inducing ligand), and other biomolecules (Fas and C-jun N-terminal kinase) are also discussed. The underlying cellular, molecular, immunological, and biochemical mechanism(s) of action responsible for liver damage (toxicity) are also been discussed. This review should be immensely useful for researchers especially for phytochemists, pharmacologists and toxicologists working on hepatotoxicity, hepatotoxic chemicals and drugs, hepatoprotective agents and drug research organizations involved especially in phytopharmaceuticals and other natural products.