糖皮质激素受体α调节剂高通量筛选模型的建立及应用

目的建立不同分子作用机制的糖皮质激素受体α(GRα)调节剂高通量筛选模型,筛选新型糖皮质激素受体调节剂。方法克隆GRα的配体结合域LBD和全长基因,构建哺乳动物细胞表达载体pBIND-GAL4-GRαLBD、pTARGETGRα,分别与已构建的含GAL4响应元件5×UAS的荧光素酶报告质粒p5×UAS-luc和含有4×GRE的报告质粒pGRE-luc共转染HeLa细胞,建立两种不同机制的报告基因细胞筛选方法,通过报告基因的表达检测化合物对GRα受体转录调控功能的调节剂作用;利用实时定量PCR方法进一步验证化合物对糖皮质激素受体靶基因mRNA水平的调控作用。结果经过分别共转染表达质粒和报告质粒,GRα激动剂地塞米松可剂量依赖地诱导5×UAS-luc和4×GRE-luc两个模型的荧光素酶的表达,在5×UAS-luc模型中,最大上调倍数可达(9.0±0.2)倍,EC50值为(0.28±0.07)mmol/L,Z’因子为0.52。在4×GRE-luc模型中,最大上调倍数可达(3.2±0.3)倍,EC50值为(1.81±0.13)mmol/L,Z’因子为0.49。利用模型pBIND-GAL4-GRαLBD/p5×UAS-luc从2000多个微生物和植物来源的天然以及合成化合物中筛选得到1个微生物来源的天然产物黑麦酮酸D,黑麦酮酸D对GRα具有2~3倍的激动活性。进一步的定量PCR的结果说明黑麦酮酸D能有效上调多个GRα调控的靶基因的表达。结论两种报告基因筛选方法灵敏、稳定,可以用于GRα调节剂的高通量筛选。     

巨噬细胞甘露糖受体结合物筛选模型的初步建立

目的建立巨噬细胞甘露糖受体(MMR)结合物筛选模型,用于筛选以甘露糖受体(MR)为靶标的潜在活性物质。方法将小鼠腹腔巨噬细胞分别与不同浓度的D-甘露糖和D-半乳糖共孵,用流式细胞仪和荧光显微镜检测D-甘露糖和D-半乳糖对Mφ结合异硫氰酸荧光素标记的甘露糖化牛血清白蛋白(M-FITC-BSA)的拮抗作用,优化实验条件,建立MMR筛选模型。结果两种检测方法均显示:随D-甘露糖浓度的上升,M-FITC-BSA标记的Mφ检出率逐步下降(P<0.01),而这种现象在D-半乳糖组中未观察到;当D-甘露糖达到0.080mmol.L-1浓度时,便能明显拮抗Mφ结合M-FITC-BSA(P<0.05或P<0.01)。中药多糖的筛选结果显示:在一定浓度下,黄芪、白术、防风、大枣等中药多糖组分能浓度依赖性地拮抗小鼠腹腔Mφ与M-FITC-BSA的结合(P<0.05或P<0.01)。结论MMR模型对MR结合成分的筛选作用稳定而敏感,对快速筛选中药免疫调节成分、研究中药免疫调节机制具有重要意义。     

基于CaCC的P2ry2调节剂细胞筛选模型的建立及应用

目的:构建基于钙激活氯离子通道(CaCC)的高通量P2Y₂嘌呤受体(P2ry2)调节剂细胞筛选模型。方法:采用RT-PCR方法验证Fischer大鼠甲状腺滤泡上皮细胞(FRT细胞)中P2ry2的mRNA表达水平,切胶回收PCR扩增产物并进行序列测序和比对,进一步应用Western blot检测FRT细胞的P2ry2蛋白表达水平。构建钙激活氯离子通道ANO1和对卤族元素敏感的黄色荧光蛋白双突变体YFP-H148Q/I152L真核表达载体,应用脂质体转染、抗生素筛选和有限稀释,获取共表达ANO1和YFP-H148Q/I152L的FRT细胞。采用倒置荧光显微镜观察共表达ANO1和YFP-H148Q/I152L细胞的情况,并应用荧光淬灭动力学实验验证模型的有效性;荧光淬灭动力学实验验证细胞模型是否可筛选P2ry2调节剂,并应用Fura-2/AM荧光探针法检测细胞内游离钙的变化,探究胞内Ca²⁺浓度与P2ry2调节剂的剂量依赖关系;用Z′因子评价本模型的稳定性和可重复性。结果:FRT细胞内源性表达P2ry2;倒置荧光显微镜中观察到ANO1在细胞膜上表达...     

药物筛选模型研究进展

药物筛选模型 (ｄｒｕｇｓｃｒｅｅｎｉｎｇｍｏｄｅｌ,ｄｒｕｇｓｃｒｅｅｎ ｉｎｇａｓｓａｙｍｅｔｈｏｄ)是用于证明某种物质具有药理活性(生物活性、治疗作用 )的实验方法 ,这些实验方法是寻找和发现药物的重要条件之一。人们在长期寻找药物的实践过程中 ,建立了大量用于新药筛选的各类模型 ,在新药发现和研究中发挥了积极作用。随着生命科学的发展 ,新的药物筛选模型不断出现 ,这些新的筛选模型不仅促进了药物的发现 ,而且对药物筛选的方法、理论、技术都产生了巨大影响[1] 。本文对近年来药物筛选模型的研究进展作简单综述。1　常用…     

以丙氨酸消旋酶为靶点的高通量抗结核药物筛选模型的建立及应用

目的建立以结核分枝杆菌丙氨酸消旋酶为靶点的新型高通量抗结核药物筛选模型,筛选丙氨酸消旋酶的抑制剂,获得以丙氨酸消旋酶为靶点的新型抗结核药物先导物。方法以结核分枝杆菌H37Rv基因组为模板,pET28a表达质粒为载体,将alr基因克隆至pET28a,构建pET28a::alr重组表达质粒,表达并纯化得到重组结核分枝杆菌丙氨酸消旋酶;通过测定反应产物NADH在340 nm处光密度变化速率,检测酶反应活性,构建并优化该酶抑制剂的高通量筛选模型;应用该模型对化合物库进行筛选;测定活性化合物IC50以及对结核分枝杆菌的MIC。结果成功构建了结核分枝杆菌alr基因的表达载体;得到了纯度较高的重组丙氨酸消旋酶,测得该酶的比活力为13.53 kU/mg;所建立的丙氨酸消旋酶高通量筛选模型稳定性高,符合高通量筛选的要求;通过对70 000个化合物进行筛选,得到了5个活性较高的化合物,其中,IMB-XZ5对结核分枝杆菌的MIC为4~8μg/ml,且对结核分枝杆菌的作用具有较高的特异性。结论建立了稳定性好、灵敏度较高的结核分枝杆菌丙氨酸消旋酶抑制剂高通量筛选模型,应用该模型筛选得到了具有较好抗结核活性的丙氨酸消旋酶抑制剂。     

外周内源性大麻受体激动剂及其受体2亚型参与搔痒调节的研究

目的研究外周内源性大麻受体激动剂及其受体2亚型在搔痒中的作用。方法C57BL/6J雄性小鼠48只分为C48/80组、氯喹组、组胺组3组,每组根据CB2受体拮抗剂MA630的量又分为高剂量组、低剂量组和对照组,MA630（2.5μg、25μg）与致痒剂C48/8010μg/100μl（C48/80组）、氯喹100μg/100μl（氯喹组）、组胺5μmol/100μl（组胺组）共同注射,观察30min内搔痒次数。结果C48/80组与氯喹组注射MA63025μg后明显增加C48/80与氯喹引起的搔痒。结论外周内源性大麻素受体激动剂通过CB2受体发挥抑制搔痒的作用。     

大麻素受体激活调控牙周炎症和骨改建促进牙周组织愈合

背景:大麻素受体通过与配体结合,调控牙周炎的炎症和骨量,促进牙周组织的愈合,在临床上牙周炎的预防和治疗方面具有重要意义。目的:综述大麻素受体与牙周炎的关系,主要为大麻素Ⅰ型(CB1)受体、大麻素Ⅱ型(CB2)受体与炎症和牙槽骨骨改建的关系,以及涉及的常见细胞信号传导通路,为牙周炎预防和治疗及其在临床其他领域的应用提供思路。方法:检索PubMed、万方数据库、CNKI中国期刊全文数据库1985年7月至2022年7月收录的相关文献。英文检索词为“cannabinoids receptor,CB1 receptor and periodontitis,CB2 receptor and periodontitis,CB1 receptors and bone remodeling,CB2 receptors and bone remodeling,CB1 receptors and signaling pathways,CB2 receptors and signaling pathways”,中文检索词为“大麻素受体,CB1受体和牙周炎,CB2受体和牙周炎,CB1受体和骨改建,CB2受体和骨...     

以蛋白激酶A为靶点的抗结核药物高通量筛选模型的建立和应用

目的 建立以蛋白激酶 A 为靶点的抗结核药物高通量筛选模型,应用该模型筛选具有特异性酶活抑制活性的微生物发酵液粗提物样品。 方法 以结核分枝杆菌 H37Rv 基因组 DNA 为模板,扩增目的基因片段 pknA,构建表达载体 pET43.1a-pknA,在大肠杆菌中克隆表达了重组 MTB PknA 蛋白;采用三步级联的反应方法,利用还原型烟酰胺腺嘌呤二核苷酸到氧化型烟酰胺腺嘌呤二核苷酸这一反应最大吸光值波长的变化,建立和优化蛋白激酶 A 抑制剂高通量药物筛选模型。 结果 成功构建了表达载体 pET43.1a-pknA;建立了稳定灵敏,可用于靶向结核分枝杆菌蛋白激酶 A 的抗结核药物高通量筛选模型;利用该模型对4000个微生物发酵液粗提物样品进行筛选,最终得到21个抑制蛋白激酶 A 活性的阳性样品,阳性率0.53%;以耻垢分枝杆菌和海分枝杆菌为检定菌,平板纸片法检测阳性样品的抗分枝杆菌活性,然后对阳性样品的细胞毒性和酶活抑制特异性进行评价后,最终得到8个阳性样品,其中 I10AA-02916、I09AA-02717、I09AB-02729、I08AB-00801这4个阳性样品酶活抑制特异性、抗菌活性均较好,且细胞毒性较低。 结论 建立了高稳定性的以蛋白激酶 A 为靶点的抗结核药物高通量筛选模型,应用该模型所得到的发酵液阳性样品值得进一步研究。     

2型糖尿病药物筛选技术研究进展

2型糖尿病的发病率逐年递增，针对其治疗而进行的寻找新药的药物筛选技术也在不断进步，从整体动物水平上升到细胞、分子水平，由传统的筛选技术发展为快速高效的高通量筛选。本文将对2型糖尿病的药物筛选技术逐一进行概述。     

人大麻素受体启动子真核报告质粒的构建及活性分析

目的:利用双荧光素酶报告基因体系,根据大麻素受体1(cannabinoid receptor 1,cnr1)启动子序列不同部位的转录活性来初步确定其活性区域,为脊髓缺血耐受保护中cnr1高表达的转录调控的研究奠定基础。方法:从NCBI中获取cnr1基因转录起始点5’端向上约1800 bp的核苷酸序列,按照300 bp的距离间隔,设计6个不同长度的截短体PCR引物,以人全血基因组DNA为模板,分别扩增cnr1启动子区域的截短体片段,并克隆入荧光素酶报告基因pGL3-Basic质粒中。将含有不同截短体的重组质粒分别转染Hela、Jurket和A549细胞后行荧光素酶活性检测。根据不同截短体转录活性检测结果,确定cnr1启动子活性区域。结果:成功将cnr1启动子区6个不同长度(1800、1500、1200、900、600和300 bp)的截短体克隆入荧光素酶报告基因pGL3-Basic质粒。在3种细胞系Hela、Jurket和A549的荧光素酶活性检测均显示600 bp的截短体转录活性最强。结论:成功构建了cnr1启动子的报告基因重组质粒,初步证实-600 bp到-200 bp区为cnr1的启动子的活性区域,从而为进一步研究cnr1的转录调控奠定了基础。     

高通量药物筛选在新药研究中的应用

高通量药物筛选技术是 2 0世纪 80年代后期形成的寻找新药的高新技术。经过十余年的实践 ,该技术体系不断发展和完善 ,成为目前寻找新药的重要手段。应用高通量药物筛选技术寻找新药 ,不仅改变了人们对药物筛选的认识 ,同时对药物开发研究的思路也产生了明显的冲击。如何应用高通量药物筛选开发新药 ,已成为目前药物研究中的重要课题之一。本文根据药物发现的基本规律 ,介绍高通量药物筛选的发展过程和基本原理方法 ,探讨高通量药物筛选在新药发现中的作用和应用前景。1　药物研究的基本过程[1 ]用于防治疾病的药物 ,都必须是经过大量研究观…     

高通量药物筛选生物活性分析技术研究进展

在过去的十年中 ,生命科学的迅速发展 ,尤其是分子生物学的发展 ,越来越多的潜在药物作用靶点被人们认识。化学合成技术的进步如组合化学的出现为发现新药提供了更多的化合物[1] ,这些进步为大规模的药物筛选创造了物质基础。为了能够应用多种药物作用靶点对大量化合物进行高速、高效、低成本、微量化的筛选 ,最大限度地发现药物 ,高通量筛选 (Ｈｉｇｈｔｈｒｏｕｇｈｐｕｔｓｃｒｅｅｎ ,ＨＴＳ)技术也快速发展起来 ,产生了许多新的实验分析方法 ,药物筛选的规模和速度也由 2 0世纪 90年代中期每天筛选几千个化合物提高到每天可筛选数万甚…     

CB2 cannabinoid receptor agonist, JWH-015, triggers apoptosis in immune cells: potential role for CB2-selective ligands as immunosuppressive agents

Cannabinoids are known to interact with CB1 and CB2 receptors expressed in the nervous and immune system, respectively, and mediate a wide range of effects, including anti-inflammatory properties. However, cannabinoids that bind CB1 are also psychoactive thereby limiting their clinical use. In this study, we investigated the immunosuppressive properties of JWH-015, a synthetic CB2-selective agonist. We found that JWH-015 triggered apoptosis in thymocytes in vitro and inhibited the proliferative response of T and B cells to mitogens through induction of apoptosis. JWH-015 induced cross-talk between extrinsic and intrinsic pathways of apoptosis involving caspase-8, caspase-9, and caspase-3 as well as loss of mitochondrial membrane potential. Finally, administration of JWH-015 in vivo caused thymic atrophy, apoptosis, and decreased peripheral T cell response to mitogens. Together, this study suggests that CB2-selective agonists, devoid of psychotropic effect, may serve as novel anti-inflammatory/immunosuppressive agents.     

Post-training CB1 cannabinoid receptor agonist activation disrupts long-term consolidation of spatial memories in the hippocampus

Cannabinoids have long been associated with mnemonic deficits. However, existing evidence has generally focused on the effect of cannabinoids when they are delivered prior to task-training, and such findings are confounded by possible drug effects on sensory, motor, and/or motivational systems that support the acquisition and the expression of learning. The present study investigated the effects of the CB1-receptor agonist WIN 55,212-2 (WIN) on memory consolidation in the Morris water maze. In experiment 1, systemic injections of either WIN or DMSO vehicle were given daily following each training day (post-training), and rats were probe-tested 1 week or 4 weeks later. Rats injected with 1 mg/kg and 3 mg/kg of WIN spent significantly less time in the target quadrant compared with controls 4 weeks later, while no difference was observed at 1-week retention. In experiment 2, intrahippocampal injections of WIN were administered to the dorsal hippocampus following each training day and rats were again probe-tested 1 week or 4 weeks later. Rats bilaterally infused with WIN at 2.5 microg and 5 microg (per side) during training spent significantly less time in the target quadrant than vehicle controls on probe trial 4 weeks later, while no difference was seen at 1-week retention. Taken together, our results showed that post-training activation of CB1 receptors in the hippocampus disrupts long-term memory consolidation but has no effect on acquisition and short-term retention. Plausible pharmacological interactions between cannabinoids and other neurotransmitter systems and associated plasticity mechanisms are discussed.     

High throughput screening: a rapid way to recombinant allergens

Complex allergenic sources such as moulds, foods and mites contain large panels of IgE-binding molecules which need to be cloned, produced and characterized in order to mimic the entire allergenicity of whole extracts reconstituted by mixing single standardized recombinant allergens. Phage display of cDNA libraries allows selective enrichment of allergen-expressing clones using IgE from allergic patients. For the characterization of all different clones present in enriched cDNA libraries in a fast and cost-effective way, however, high-throughput screening technology is required. We have used a high-throughput, quantitative technology for fast identification of all different clones present in selectively enriched phage surface-displayed cDNA libraries in order to characterize whole allergenic repertoires from complex allergenic sources. The strategy, based on a combination of phage display and high-density arrays, allowed fast discovery of panels of related structures from different allergenic sources. They cover secreted, cytoplasmic and structural proteins with or without enzymatic activity and offer a rational explanation for the IgE-mediated cross-reactivity frequently encountered in clinical practice.     

CB2受体激动剂JWH133对百草枯中毒致急性肺损伤大鼠的保护作用

 目的:研究大麻素CB2受体激动剂JWH133对百草枯中毒致急性肺损伤大鼠的保护作用。方法: 72只SD雄性大鼠随机平均分成4组。百草枯中毒组：按照20 mg/kg剂量腹腔注射;低剂量JWH133预处理组：在给予百草枯腹腔注射前1 h腹腔注射5 mg/kg JWH133;高剂量JWH133预处理组：在给予百草枯腹腔注射前1 h腹腔注射20 mg/kg JWH133;正常对照组：1 mL生理盐水腹腔注射。在注射百草枯后8 h、1 d和3 d时,收集动脉血、肺泡灌洗液和肺组织标本。采用血气分析仪测定动脉血氧分压（PaO2）,采用ELISA方法检测支气管肺泡灌洗液中IL-1β和TNF-α含量,行组织切片HE染色进行肺损伤评分,利用Western blotting方法检测肺组织中NF-κB和AP-1 蛋白表达水平。结果: 与正常对照组相比,百草枯中毒组大鼠的动脉血PaO2明显下降,肺组织结构破坏,肺泡间质水肿,肺损伤指数增加,支气管肺泡灌洗液中炎性细胞因子IL-1β和TNF-α含量明显增加。JWH133预处理,尤其是高剂量JWH133可以减轻肺组织损伤程度,降低支气管肺泡灌洗液中IL-1β和TNF-α含量,减少肺组织中NF-κB和AP-1 蛋白的表达。结论: 应用CB2受体激动剂JWH133可以抑制百草枯中毒大鼠肺组织中NF-κB和AP-1 蛋白的表达,减少炎性细胞因子IL-1β和TNF-α的分泌,减轻百草枯中毒导致的急性肺损伤。     

Antinociceptive effect of intrathecal cannabinoid receptor agonist WIN 55,212-2 in a rat bone tumor pain model

Bone tumor pain is a poorly controlled pain comprising background and severe pain on moving or weight-bearing postures that decreases the quality of life for cancer patients; thus, more effective analgesics are clearly needed. This study evaluated the efficacy of a cannabinoid (CB) receptor agonist (WIN 55,212-2) on bone tumor pain in the spinal cords of rats, and clarified the roles of the CB1 and CB2 receptors in WIN 55,212-2-induced antinociception at the spinal level. Bone tumor pain was induced by injecting MRMT-1 tumor cells (1×10(5)) into the right tibias of female Sprague-Dawley rats under sevoflurane anesthesia. Bone tumor development was monitored radiologically. Under sevoflurane anesthesia, a polyethylene catheter was inserted into the intrathecal space for drug administration. To assess pain, the withdrawal threshold was measured by applying a von Frey filament to the tumor cell inoculation site. The effect of intrathecal WIN 55,212-2 was investigated. Next, the WIN 55,212-2-mediated antinociception was reversed using CB1 (AM 251) and CB2 (AM 630) receptor antagonists. The intratibial injection of MRMT-1 tumor cells produced radiologically confirmed bone tumors. The paw withdrawal threshold decreased significantly (mechanical allodynia) with tumor development; however, intrathecal WIN 55,212-2 dose-dependently increased the withdrawal threshold. The antinociceptive effect of WIN 55,212-2 was reversed by both CB1 and CB2 receptor antagonists. Intrathecal WIN 55,212-2 reduced bone tumor-related pain behavior mediated via spinal CB1 and CB2 receptors. Therefore, spinal CB receptor agonists may be novel analgesics in the treatment of bone tumor pain.     

An induced thymic epithelial cell-based high throughput screen for thymus extracellular matrix mimetics

Thymic epithelial cells (TECs) are key effectors of the thymic stroma and are critically required for T-cell development. TECs comprise a diverse set of related but functionally distinct cell types that are scarce and difficult to isolate and handle. This has precluded TEC-based screening assays. We previously described induced thymic epithelial cells (iTECs), an artificial cell type produced in vitro by direct reprogramming, raising the possibility that iTECs might provide the basis for functional screens related to TEC biology. Here, we present an iTEC-based three-stage medium/high-throughput in vitro assay for synthetic polymer mimics of thymic extracellular matrix (ECM). Using this assay, we identified, from a complex library, four polymers that bind iTEC as well as or better than gelatin but do not bind mesenchymal cells. We show that these four polymers also bind and maintain native mouse fetal TECs and native human fetal TECs. Finally, we show that the selected polymers do not interfere with iTEC function or T-cell development. Collectively, our data establish that iTECs can be used to screen for TEC-relevant compounds in at least some medium/high-throughput assays and identify synthetic polymer ECM mimics that can replace gelatin or ECM components in TEC culture protocols.