含硼小分子固醇调控元件结合蛋白抑制剂的合成及其体外抗肿瘤活性研究

目的设计、合成固醇调控元件结合蛋白(SREBP)抑制剂BF-175的衍生物,并对其稳定性和体外抗肿瘤活性进行研究。方法以水杨醛为起始原料,通过6步反应合成了一系列含硼小分子SREBP抑制剂,通过高效液相色谱法分析其稳定性,并采用RT-PCR实验评价其抗肿瘤活性。结果合成了9个含硼小分子SREBP抑制剂,并通过NMR和MS对其进行表征。其药学稳定性均优于BF-175。RT-PCR检测表明目标化合物可以抑制人子宫内膜腺癌细胞(AN3CA)中SREBP靶基因硬脂酰辅酶A去饱和酶-1(SCD-1)的表达,其中化合物7g的活性高于BF-175。结论含硼小分子SREBP抑制剂具有较好的抗肿瘤活性,为此类药物的作用机制研究奠定了基础。     

基于双荧光素酶报告基因系统的人源SREBP1基因启动子的活性研究

目的 构建固醇调节元件结合蛋白 1（SREBP1）启动子双荧光素酶报告基因表达载体,为研究针对 SREBP1靶点的天然活性抑制剂筛选奠定基础。方法 利用生物信息学软件,对SREBP1基因5′端上游5 000 bp序 列进行启动子预测与分析。应用 Gibson Assembly 方法构建启动子双荧光素酶载体,并将构建成功的 pGL3- SREBP1-pro重组质粒和内参质粒pRL-SV40共转染肝癌HepG2细胞并给予天然抑制剂大黄素,检测SREBP1转录活 性的抑制效果。结果 SREBP1基因5′端上游2 000 bp区域内有启动子特征序列,存在转录因子结合位点;重组质粒 经酶切及测序鉴定证实为阳性克隆,瞬时转染肝癌HepG2细胞后经双荧光素酶报告基因系统检测,所克隆的片段序 列具有启动子活性,该活性可被大黄素所抑制。结论 成功构建了pGL3-SREBP1-pro双荧光素酶报告基因表达载 体,并证实其活性,可为进一步用于针对SREBP1靶点的天然活性抑制剂筛选奠定     

大鼠牙移动中骨钙蛋白和半胱氨酸蛋白酶抑制剂C在牙周组织的表达及其相关性研究

近年来。关于正畸牙移动过程中牙周组织改建的分子生物学机制越来越受到正畸科医生的关注．研究发现骨钙蛋白（OCN）是骨中最丰富的非胶原蛋白质之一,由成骨细胞合成和分泌。是成骨细胞特异性标志。OCN具有骨代谢调节激素作用,参与调节骨转化过程,其mRNA水平的高低与成骨直接相关。半胱氨酸蛋白酶抑制剂C（Cystatinc）有促进骨形成、抑制骨吸收等作用[43,在牙龈炎和牙周炎患者中CystatinC含量很高。本实验旨在研究正畸牙移动过程中OCN和CystatinC表达的时间分布特点．及二者相关性的研究．进一步探讨牙周组织改建过程中的分子生物学机制,从而为临床提供指导。     

几类非甾体抗炎药物的研究进展（一）

白三烯（LT）抑制剂和受体拮抗剂、血小板活化因子（PAF）受体拮抗剂和合成酶抑制剂、磷脂酶A2（PLA2）抑制剂都是非甾体抗炎药，通过 抑制炎症介质活性或拮抗其受体，阻断或减轻炎症过程。应用该类药物对治疗炎症疾病有良好前景。本综述了它们近年来的研究进展。     

大黄酚对Huh-7细胞SREBP表达及脂质代谢的影响

大黄具有泻下、降脂和减肥等作用,但其降脂药效物质及作用机制尚不清楚。本文探讨大黄的主要活性成分大黄酚(chrysophanol)对人肝癌细胞株(human liver carcinoma Huh-7 cells,Huh-7)固醇调节元件结合蛋白(sterol regulatory element-binding proteins,SREBPs)表达及脂质代谢的影响。以双荧光素酶报告基因检测试剂盒检测大黄酚对SREBP的转录抑制作用;总胆固醇(total cholesterol,TC)和甘油三酯(triglyceride,TG)测定试剂盒检测细胞内TC、TG水平;荧光定量RT-PCR法检测SREBP及靶基因m RNA的表达;采用CCK-8试剂盒检测细胞存活率。结果显示,经大黄酚(40μmol·L-1)干预16 h后,使细胞内TC、TG水平显著减少;大黄酚可以抑制SREBP转录,并呈现出一定的浓度依赖性;能显著下调SREBP及靶基因的表达;大黄酚对细胞活力无明显影响。结果提示,大黄酚可能通过下调肝细胞SREBP及靶基因的表达,从而降低细胞内TC、TG的含量,减轻肝细胞脂肪变性,起到改善脂质代谢的作用。     

胰岛素对骨骼肌细胞固醇调节原件结合蛋白1c的调节作用

目的：研究胰岛素对骨骼肌细胞固醇调节原件结合蛋白1c（SREBP‐1c）的调节作用。方法将诱导分化完成的大鼠骨骼肌L6肌管细胞分为对照组、胰岛素组、磷酸酰基醇3激酶抑制剂wortmannin＋胰岛素组、单磷酸腺苷依赖的蛋白激酶（AM PK ）抑制剂compound C＋胰岛素组、高脂对照组、高脂＋胰岛素组、高脂＋wortmannin＋胰岛素组和高脂＋compound C＋胰岛素组。Western blot检测SREBP‐1c、苏氨酸蛋白激酶（Akt）‐哺乳动物雷帕霉素靶蛋白（mTOR）、AMPK‐mTOR通路相关蛋白的表达。结果与对照组相比,胰岛素组SREBP‐1c、p‐Akt、p‐AMPK、p‐mTOR蛋白表达升高（P＜0．05）;与胰岛素组相比,wortmannin＋胰岛素组SREBP‐1c表达降低（P＜0．05）;与高脂对照组相比,高脂＋胰岛素组 SREBP‐1c、p‐mTOR 蛋白表达降低,p‐Akt、p‐AMPK 蛋白表达升高（P＜0．05）;与高脂＋胰岛素组相比,高脂＋compound C＋胰岛素组SREBP‐1c表达升高（P＜0．05）。结论骨骼肌细胞生理状态下,胰岛素对SREBP‐1c的上调作用可能主要通过Akt‐mTOR通路;胰岛素抵抗状态下,胰岛素治疗对SREBP‐1c的下调作用可能主要通过AMPK‐mTOR通路。     

PDE的研究与创新药的开发

环核苷酸（cAMP和cGMP）是细胞内重要的第二信使，在各种细胞内调节许多生物活性，包括细胞成长、分化及移行、基因表达、介质分泌、平滑肌收缩、神经递质引起的各种生物反应、神经突触功能、脂质及糖质代谢等。环核苷酸磷酸二酯酶（PDE）是环核昔酸的惟一细胞内分解途径，因而PDE抑制剂通过阻碍环核苷酸的分解，从而调节一系列的生物功能。PDE大家族共包括11个家族（PDE1～11），     

人参皂苷Compound K通过AMPK及SREBP1途径改善非酒精性脂肪肝的机制研究

目的：研究人参皂苷Compound K（CK）对非酒精性脂肪肝的改善作用及其与腺苷酸激活蛋白激酶（AMPK）及固醇调节元件结合蛋白（SREBP1）信号转导通路的关系。方法：采用高脂饲料喂养C57BL/6J雄性小鼠9周,建立非酒精性脂肪肝动物模型;9周后随机分为5组,正常饲料组（RD）,高脂饲料组（HFD）,给药组（HFD+CK 3,9,27 mg·kg^-1）,每天灌胃给药1次,每周测2次体质量,连续11周。实验结束后,分别称量小鼠体质量和肝质量;检测三酰甘油（TG）、胆固醇（cholesterol）、非游离脂肪酸（NEFA）、谷草转氨酶（AST）和谷丙转氨酶（ALT）水平。苏木素-伊红（HE）染色观察肝脏病理变化,Western blot法检测AMPK和乙酰辅酶A羧化酶（ACC）的磷酸化表达,PCR法检测脂肪合成转录因子SREBP1及其靶基因（FAS、SCD1）的基因表达。结果：治疗11周后,与RD组比较, HFD组小鼠肝质量及肝质量与体质量的比值显著增加（P<0.001,P<0.05）,HE染色显示HFD组较RD组肝细胞明显增大且伴有大泡性脂肪变,说明高脂饲料诱导非酒精性脂肪肝模型的建立。与HFD组比较,给药组小鼠体质量、肝质量显著降低（P<0.05）,血脂（TG、CHO、NEFA）和肝功（sAST和sALT）指标也显著降低（P<0.05,P<0.01,P<0.001）;HE染色也说明给药组能够明显改善肝脏病理状态,从而改善肝细胞脂肪变性;Western blot结果显示HFD组较RD组,AMPK和ACC磷酸化均被抑制,给药组较HFD组,AMPK和ACC均被磷酸化,且随药物浓度的增加,磷酸化越明显;PCR法结果显示HFD较RD组,脂肪合成转录因子SREBP1及其靶基因表达显著增强,而在给药组上述基因表达均显著被抑制。结论：CK对非酒精性脂肪肝具有改善作用,其机制之一可能是通过激活AMPK和ACC的磷酸化、抑制脂肪合成转录因子SREBP1及其靶基因的表达来实现的。     

细胞因子、受体及其抑制剂

细胞因子是一种具有重要生物学活性的细胞调节蛋白。过量的细胞因子会导致全身或局部毒性反应,所以需要通过抑制细胞因子的合成及采用对抗作用机制来限制其活性以严格控制其含量。有两种细胞因子抑制机制：（1）产生与受体结合而不激发生物活性的受体抑制剂：（2）产生可溶性受体,与细胞因子所键合的受体竞争。     

AKR1B10抑制剂的研究进展

Aldo-keto reductase family1,member10（AKR1B10）属醛酮还原酶超家族（AKRs）中AKR1家族的成员之一。醛酮还原酶在不同的生物体中可能参与了不同的生物学过程,包括羰基解毒、渗透调节、激素代谢、脂质合成、糖尿病并发症、肿瘤的形成等。目前,AKR1B10已被证明在肿瘤细胞中特异性表达,而在正常组织细胞中分布较窄。因此,以其为靶点的抗肿瘤药物研究近年来被广泛关注。本文从来源于天然和化学合成2个方向的AKR1B10抑制剂进行分类与总结,并对其化学结构及结构修饰对于抑制活性和选择性的影响进行综述。     

Monacolin K affects lipid metabolism through SIRT1/AMPK pathway in HepG2 cells

Monacolin K is the secondary metabolite isolated from Monascus spp. It is the natural form of lovastatin, which is clinically used to reduce the synthesis of cholesterol by inhibiting 3-hydroxy-3-methylglutaryl coenzyme A reductase. In the present study, monacolin K increased protein expression of SIRT1 and phosphorylation level of AMP-activated protein kinase (AMPK) in HepG2 cells. Through activation of SIRT1/AMPK pathway, monacolin K increased phosphorylation of acetyl CoA carboxylase and caused nuclear translocation of forkhead box O1. The western blotting results showed that monacolin K increased expression of adipose triglyceride lipase but decreased abundances of fatty acid synthase (FAS) and sterol regulatory element-binding protein 1 (SREBP1). Monacolin K also decreased the intracellular accumulation of lipids as demonstrated by Oil Red O staining. In addition, the immunostaining showed that monacolin K prevented the nuclear translocation of SREBP1, indicating the association with down-regulation of FAS. All the demonstrated effects of monacolin K were counteracted by nicotinamide or compound C, the inhibitors of SIRT1 or AMPK. In summary, monacolin K reduces the lipid content through SIRT1/AMPK pathway in HepG2 cells, which promotes catabolism and inhibits anabolism of lipid.     

合成类丝氨酸蛋白酶抑制剂的研究进展

合成类丝氨酸蛋白酶抑制剂是人工合成的非肽类小分子化合物，具有广谱抑制性，无抗原性，相对分子质量小，可以自由进入血管及胰腺组织，能直接作用于胰腺细胞上，抑制胰酶（trypsin）、血纤维蛋白溶酶（plasmin）、血浆激肽释放酶（plasmakellilrein）、凝血酶（throbin）及补体酯酶C1和C1r。目前已获准上市的药物有加贝酯、奈莫司他、卡莫司他和司匹司他，临床主要用于急、慢性胰腺炎和弥散性血管内凝血的治疗。     

Structure-based design of novel Chk1 inhibitors: insights into hydrogen bonding and protein-ligand affinity

We report the discovery, synthesis, and crystallographic binding mode of novel furanopyrimidine and pyrrolopyrimidine inhibitors of the Chk1 kinase, an oncology target. These inhibitors are synthetically tractable and inhibit Chk1 by competing for its ATP site. A chronological account allows an objective comparison of modeled compound docking modes to the subsequently obtained crystal structures. The comparison provides insights regarding the interpretation of modeling results, in relationship to the multiple reasonable docking modes which may be obtained in a kinase-ATP site. The crystal structures were used to guide medicinal chemistry efforts. This led to a thorough characterization of a pair of ligand-protein complexes which differ by a single hydrogen bond. An analysis indicates that this hydrogen bond is expected to contribute a fraction of the 10-fold change in binding affinity, adding a valuable observation to the debate about the energetic role of hydrogen bonding in molecular recognition.     

How lipidomics provides new insight into drug discovery

Introduction: Automated lipidomic methods based on mass spectrometry (MS) are now proposed to screen a large variety of candidate drugs available that inhibit de novo lipid synthesis and replace tedious methods based on radiotracer incorporation. A major new interest in inhibitors of de novo lipogenesis is their proapoptotic effect observed in cancerous cells.

Areas covered: In this review, the authors focus on the screening methods of antilipogenic inhibitors targeting the synthesis of malonylCoA (carbonic anhydrase, acetylCoA carboxylase), palmitylCoA (fatty acid synthase condensing and thioesterase subunits) and monounsaturated fatty acids (Δ9-desaturase). The consequences of inhibition depend on how the pathway deviates above the blockade: accelerated mitochondrial fatty acid oxidation following the decreased malonylCoA level, accumulation of ketone bodies and increased cholesterol synthesis following the increased acetylCoA level. Side effects such as anorexia and skin defects may critically decrease therapeutic indices in the long term. The authors emphasize the need for assessment of toxicity in short-term treatments inducing proapoptotic effects observed in aggressive hormone-dependent malignancies.

Expert opinion: The activity of lipogenesis inhibitors can be recognised in lipid profiles established by a combination of MS-based measurements and multivariate analysis processing hundreds of lipid molecular species. Because the method can be automated, it is suitable for screening large chemical libraries, with particular focus on anticancer activities.     

以黄嘌呤氧化酶为靶点的新型非嘌呤类抗痛风及高尿酸血症药物研究进展

黄嘌呤氧化酶（XO）催化黄嘌呤生成尿酸及次黄嘌呤生成黄嘌呤的过程,是抗高尿酸血症或痛风药物研究的关键靶点。黄嘌呤氧化酶抑制剂由于作用机制明确、疗效显著而倍受关注,研发新型XO抑制剂具有广阔的应用前景。XO的结构生物学及分子模拟技术为新一代非嘌呤类XO抑制剂的合理药物设计奠定了基础。本文综述了以黄嘌呤氧化酶为靶标的新型非嘌呤类小分子杂环化合物及天然产物来源的活性分子在抗高尿酸血症或痛风药物研究领域中的进展。     

Inhibition of lipid droplet accumulation in mouse macrophages by stemphone derivatives

From a study on the biological activity of fungal stemphones and their derivatives, five derivatives having an O-alkyl moiety at C-11 of stemphone C were found to inhibit lipid droplet accumulation in macrophages without any cytotoxic effect. Among the derivatives, those having O-isopropyl and O-isobutyl were the most potent inhibitors by blocking the synthesis of both cholesteryl ester (CE) and triacylglycerol (TG), the main constituents of lipid droplets in macrophages.     

α-葡萄糖苷酶抑制剂的研究及应用

概述α-葡萄糖苷酶抑制剂的化学结构特点、作用机制、制备途径与临床应用情况。临床上常用的降糖药阿卡波糖、伏格列波糖、米格列醇为一类微生物来源的α-葡萄糖苷酶抑制剂,其与寡糖结构类似,因此可竞争性地与α-葡萄糖苷酶结合,阻滞寡糖水解成单糖,从而降低餐后血糖峰值。并且某些α-葡萄糖苷酶抑制剂还具有抗HIV活性。     

Bcl-2蛋白天然产物抑制剂的研究进展

研究表明Bcl-2蛋白过度表达会阻止正常的细胞凋亡,是肿瘤产生及发生耐药的重要原因之一.近几年,其抗肿瘤小分子抑制剂的研究逐渐成为热点.研究者发现了一些不同结构类型的抑制剂,其中天然产物占很大比重.文中对已发现的Bcl-2蛋白天然产物抑制剂(包括棉酚、红桔酚、茶多酚、抗菌霉素A3)的结构、生物活性、与蛋白结合模式及结构改造等方面进行了系统的综述,着重介绍了几类经结构改造后活性较好的棉酚衍生物(ApoGossypol,Tw37,TM-1206,BI-33),期望对从天然产物中寻找Bcl-2抑制剂以及合理设计抑制剂提供帮助.     

Antibiotic GE2270 a: a novel inhibitor of bacterial protein synthesis. I. Isolation and characterization

A novel antibiotic, GE2270 A, was isolated from the fermentation broth of a strain of Planobispora rosea. The product was found to inhibit bacterial protein synthesis. Structural characteristics showed similarities between GE2270 A and thiazolyl peptides such as micrococcin which is known to inhibit protein synthesis by acting directly on the ribosome. Despite this similarity GE2270 A showed functional analogy to kirromycin-like antibiotics and pulvomycin, as its molecular target was found to be elongation factor Tu (EF-Tu). GE2270 A is active against Gram-positive microorganism and anaerobes and differs from the other EF-Tu inhibitors in its spectrum of antimicrobial activity.