药物筛选技术的最新进展--高内涵筛选

化合物活性筛选是创新药物研究过程的起点和具有决定意义的关键步骤。基于细胞的高内涵药物筛选技术实现了对化合物多靶点多参数的同时检测，代表着创新药物研究技术发展的必然趋势，将在未来的新药研发过程中发挥重要作用。笔者介绍了高内涵筛选技术的概念、系统组成，分析了其优势特点，并简要讨论了其在新药研究尤其是抗肿瘤药物研究中的实际应用。     

Establishment of a novel cell-based assay for screening small molecule antagonists of human interleukin-6 receptor

Aim:

Blockade of interleukin-6 (IL-6) or its receptor (IL-6R) is effective in preventing the progression of autoimmune diseases, such as systemic lupus erythematosus and rheumatoid arthritis. In the present study, we established a novel cell-based assay for identifying small molecule IL-6R antagonists.

Methods:

HEK293A cells were transfected with recombinant plasmids pTaglite-SNAP-IL6R and pABhFc-IL6 to obtain membrane-bound IL-6R and recombinant human IL-6 coupled with human Fc fragment (rhIL-6), respectively. A novel screening assay based on the interaction between IL-6R and rhIL-6 was established, optimized and validated. The stability of the assay was also assessed by calculating the Z′-factor.

Results:

RhIL-6 dose-dependently bound to IL-6R expressed at HEK293A cell surface. The IC₅₀ value of the known antagonist ab47215 was 0.38±0.08 μg/mL, which was consistent with that obtained using the traditional method (0.36±0.14 μg/mL). The value of Z′-factor was 0.68, suggesting that the novel assay was stable for high throughput screening. A total of 474 compounds were screened using the novel screening assay, and 3 compounds exhibited antagonistic activities (IC₅₀=8.73±0.28, 32.32±9.08, 57.83±4.24 μg/mL). Furthermore, the active compounds dose-dependently inhibited IL-6-induced proliferation of 7TD1 cells, and reduced IL-6-induced STAT3 phosphorylation in U937 cells.

Conclusion:

A novel cell-based screening assay for identifying small molecule IL-6R antagonists was established, which simplifies the procedures in traditional cellular ELISA screening and profiling and reduces the costs.     

A rapid screening assay for identifying mycobacteria targeted nanoparticle antibiotics

Antibiotic resistance is a serious problem. Nanotechnology offers enormous potential in medicine, yet there is limited knowledge regarding the toxicity of nanoparticles (NP) for mycobacterial species that cause serious human diseases (e.g. tuberculosis (TB) and leprosy). Mycobacterial diseases are a major global health problem; TB caused by Mycobacterium tuberculosis (Mtb) kills up to 2 million people annually and there are over 200?000 leprosy cases each year caused by Mycobacterium leprae (M. leprae). Few drugs are effective against these mycobacteria and increasing antibiotic resistance exacerbates the problem. As such, alternative therapies are urgently needed but most current assays used to assess the effectiveness of therapeutics against mycobacteria are slow and expensive. This study aimed to develop a rapid, low-cost assay which can be used for screening the antimicrobial properties of compounds against pathogenic mycobacteria and to assess the toxicity of three NP (silver [Ag], copper oxide [Cu(II)O], and zinc oxide [ZnO]) against a green fluorescent protein reporter strain of Mycobacterium avium subspecies paratuberculosis, a slow growing, pathogenic mycobacterial species causing paratuberculosis in ruminants. Fluorescence was used to monitor mycobacterial growth over time, with NP concentrations of 6.25–100?μg/mL tested for up to 7 days, and a method of data analysis was designed to permit comparison between results. Mycobacterial sensitivity to the NP was found to be NP composition specific and toxicity could be ranked in the following order: Ag?>?Cu(II)O?>?ZnO.     

A semi-automated neutral red based chemosensitivity assay for drug screening

Summary A semi-automated colorometric chemosensitivity assay was developed. The assay utilizes the vital stain neutral red for the rapid screening of potential anticancer agents using solid tumor cell lines. The cell lines used in this assay and presented in this report are CX-1 colon adenocarcinoma and A549 lung carcinoma. The assay, performed in 96 well tissue culture plates, allows for short drug exposure times (3 hrs.) followed by quantitation of cell number (neutral red absorbance) following four cell doubling times.Cell number directly correlated with absorbance of eluted neutral red at 540 nm. However, optimal amounts of dye and staining times varied between cell lines.IC50 concentrations (for inhibition of cell growth) determined using this assay were in good agreement with results from clonogenic assays using similar drug treatment conditions.The assay technique was determined to be capable of detecting antineoplastic compounds operating by a wide variety of mechanisms.     

以RNA为靶标的药物筛选新技术

新药的开发有赖于新的筛选靶标和筛选模型的建立。传统上抗生素是以必需酶、受体、离子通道等为靶标进行筛选的。近年来,随着人类基因组和微生物基因组工作的进展,以RNA为靶标筛选新型抗生素的工作已越来越受到重视,rRNA、mRNA、病毒基因RNA和核酶等都可以作为药物筛选的靶标[1     

以K562细胞为靶点的抗肿瘤药物筛选模型的建立

目的：建立以白血病细胞系K562为靶点的高通量抗肿瘤药物筛选模型。方法：在96孔细胞培养板上,运用四唑氯化合物（MTS）和电子耦联剂（PMS）连用的方法,对K562细胞增殖情况进行检测。对在化合物影响下K562细胞增殖变化的检测条件进行了优化。结果：采用这一细胞水平的高通量抗肿瘤药物筛选模型,完成了800个小分子有机化合物的筛选,每个化合物的用量是500ng.11个化合物在浓度为5mg/L时可抑制细胞增殖达80％以上,其中9个通过多浓度复筛得到了确认。抑制活性最强的化合物的IC50为170nmol/L,共有7个化合物显示IC50低于10μmol/L。结论：采用K562细胞系进行高通量筛选是快速、经济、有效、实用的发现新型抗肿瘤药物的方法。     

Developments with bead-based screening for novel drug discovery

ABSTRACT

Introduction: Combinatorial chemistry provides a cost-effective method for rapid discovery of drug hits/leads. The one-bead-one-compound (OBOC) library method is in principle ideally suited for this application, because it permits a large number of structurally diverse compounds to be rapidly synthesized and simultaneously screened for binding to a target of interest. However, application of OBOC libraries in drug discovery has encountered significant technical challenges.

Areas covered: This Special Report covers the challenges associated with first-generation OBOC libraries (difficulty in structural identification of non-peptidic hits, screening biases and high false positive rates, and poor scalability). It also covers the many strategies developed over the past two decades to overcome these challenges.

Expert opinion: With most of the technical challenges now overcome and the advent of powerful intracellular delivery technologies, OBOC libraries of metabolically stable and conformationally rigidified molecules (macrocyclic peptides and peptidomimetics, rigidified acyclic oligomers, and D-peptides) can be routinely synthesized and screened to discover initial hits against previously undruggable targets such as intracellular protein-protein interactions. On the other hand, further developments are still needed to expand the utility of the OBOC method to non-peptidic chemical scaffolds.     

In silico screening strategies for novel inhibitors of parasitic diseases

Introduction: Parasitic diseases are a major global problem causing long-term disability and death, with severe medical and psychological consequences around the world. Despite the prevalence of parasitic disease, the treatment options for many of these illnesses are still inadequate and there is a dire need for new antiparasitic drugs. In silico screening techniques, which are powerful strategies for hit generation, are widely being applied in the design of new ligands for parasitic diseases.

Areas covered: This article analyses the application of ligand- and structure-based virtual screening strategies against a variety of parasitic diseases and discusses the benefits of the integration between computational and experimental approaches toward the discovery of new antiparasitic agents. The analysis is illustrated by recent examples, with emphasis on the strategies reported within the past 2 years.

Expert opinion: Virtual screening techniques are powerful tools commonly used in drug discovery against parasitic diseases, which have provided new opportunities for the identification of several novel compound classes with antiparasitic activity.     

极化荧光在高通量药物筛选中的应用

1　前言基于荧光技术的检测分析方法是近年来被应用于药物高通量筛选 (high throughputscreening,HTS)的重要方法之一,荧光检测方法具有灵敏度高、方法简便的优点,目前应用于HTS的荧光技术包括均相时间分辨荧光分析法 (homogeneoustimeresolvedfluorescence,HTRF),荧光共振能量     

A high content screening assay for identifying lysosomotropic compounds

Lysosomes are acidic organelles that are essential for the degradation of old organelles and engulfed microbes. Furthermore, lysosomes play a key role in cell death. Lipophilic or amphiphilic compounds with a basic moiety can become protonated and trapped within lysosomes, causing lysosomal dysfunction. Therefore, high-throughput screens to detect lysosomotropism, the accumulation of compounds in lysosomes, are desirable.Hence, we developed a 96-well format, high content screening assay that measures lysosomotropism and cytotoxicity by quantitative image analysis. Forty drugs, including antidepressants, antipsychotics, antiarrhythmics and anticancer agents, were tested for their effects on lysosomotropism and cytotoxicity in H9c2 cells. The assay correctly identified drugs known to cause lysosomotropism and revealed novel information showing that the anticancer drugs, gefitinib, lapatinib, and dasatinib, caused lysosomotropism. Although structurally and pharmacologically diverse, drugs that were lysosomotropic shared certain physicochemical properties, possessing a ClogP > 2 and a basic pKa between 6.5 and 11. In contrast, drugs which did not lie in this physicochemical property space were not lysosomotropic. The assay is a robust, rapid screen that can be used to identify lysosomotropic, as well as, cytotoxic compounds, and can be positioned within a screening paradigm to understand the role of lysosomotropism as a contributor to drug-induced toxicity.     

以GLP-1受体为靶点的药物筛选细胞模型的建立和应用

建立以GLP-1信号通路为靶点的药物筛选细胞模型,用于筛选GLP-1受体激动剂类的新型抗糖尿病药物。首先构建GLP-1受体信号通路调控的特异应答元件（RIP-CRE）多拷贝序列及报告基因E-GFP的重组载体。将该载体转染胰岛NIT-1细胞株,以检测转染细胞对GLP类似物的反应性和特异性,并通过稳定转染和单克隆培养,获得对GLP-1类似物特异应答的单克隆细胞株。该细胞模型在GLP-1类似物Exendin 4刺激下激活表达报告基因,激活作用可以被GLP-1受体阻断剂Exendin 9-39完全阻断,且激活途径非cAMP-PKA依赖,具有GLP-1受体特异性。构建该细胞模型,可以对肽类或非肽类GLP-1类似物进行高通量筛选。     

改良溴化四唑蓝法在筛选抗癌新药的应用

目的 探讨筛选抗癌新药的良好方法。方法 用溴化四唑蓝改良法对１０株体外培养的各类肿瘤细胞筛选抗癌新药。结果 改良法对筛选中草药野荞根提限物“金Ｅ”获得稳定和重复性好的实验结果。结论ＭＴＴ改良法灵敏度高，特异性强，是筛选有效药物的良好方法。     

全新长春氟宁衍生物体内外药效筛选

目的:对29个全新长春氟宁衍生物进行体内、外药效筛选,以期发现具有开发前景的抗肿瘤化合物.方法:体外筛选采用SRB法,移植入非小细胞肺癌A549裸小鼠模型作为体内药效模型.结果:通过体外IC50结果,结合化学结构,挑选出2个较有优势化合物:SHRll5706和SHR115766,IC50分别为0.05和0.29μmol·L-1.SHR115706能够剂量依赖性的抑制裸鼠移植肿瘤的生长,抗癌疗效与长春氟宁相当;SHR115766亦可抑制肿瘤的生长,但剂量依赖性不明显.SHR115706(80 mg·kg-1),SHR115766(80 mg·kg-1)和长春氟宁(35 mg·kg-1,作为阳性对照)组肿瘤增殖速率分别为47.5%,57.6%和46.5%.SHR115706和SHR115766对裸鼠表现的毒性均明显低于长春氟宁.结论:SHR115706有望成为抗肿瘤新药.     

An update of novel screening methods for GPCR in drug discovery

Introduction: G protein-coupled receptors (GPCRs) are the largest and most versatile group of cytomembrane receptors, comprising of approximately 300 non-sensory and druggable members. Traditional GPCR drug screening is based on radiometric competition binding assays, which are expensive and hazardous to human health. Furthermore, the paradox of high investment and low output, in terms of new drugs, highlights the need for more efficient and effective drug screening methods.

Areas covered: This review summarizes non-radioactive assays assessing the ligand–receptor binding including: the fluorescence polarization assay, the TR-FRET assay and the surface plasmon resonance assay. It also looks at non-radioactive assays that assess receptor activation and signaling including: second messenger-based assays and β-arrestin recruitment-based assays. This review also looks at assays based on cellular phenotypic change.

Expert opinion: GPCR signaling pathways look to be more complicated than previously thought. The existence of receptor allosteric sites and multireceptor downstream effectors restricts the traditional assay methods. The emergence of novel drug screening methods such as those for assessing β-arrestin recruitment and cellular phenotypic change may provide us with improved drug screening efficiency and effect.     

The anti-mitochondrial antifungal assay for the discovery and development of new drugs

Introduction: New targets and drugs are constantly searched for to effectively combat fungal infections and diseases such as cancer. Mitochondria, as the main powerhouses of eukaryotic cells, must be regarded as important targets for the development of new therapies. This has lead to the development of a fungal assay that shows potential in the selection of new antifungal and anticancer drugs as well as the identification of compounds that are toxic to human mitochondria.

Areas covered: In this review the authors discuss the development of a potential method of drug discovery that targets mitochondrial function. The authors cover the application of new nanotechnology as well as fungal systematic research where the link between fungal fruiting structures, cell growth, increased mitochondrial activity and susceptibility to a variety of anti-mitochondrial drugs is assessed.

Expert opinion: This assay shows potential to select anti-mitochondrial drugs as a first screen. This should be followed up by more specific in vitro and in vivo tests to pinpoint the type of anti-mitochondrial activity exerted by these drugs, if any. This is because the possibility exists that compounds regarded as anti-mitochondrial may not inhibit mitochondrial function but other fruiting structure developmental stages and therefore yield false positives. To enhance our knowledge on how these drugs act at the structural level, the authors recommend Nano Scanning Auger Microscopy as the tool of choice.     

HIV-1前体蛋白早成熟化激活剂筛选模型的建立及应用

HIV-1蛋白酶 (PR) 活性的严格调控对于病毒的生存至关重要。在病毒蛋白表达及病毒颗粒装配过 程中, 处于病毒前体蛋白Gag-Pol中的蛋白酶必须以无活性状态存在, 避免前体蛋白Gag-Pol和Gag被提前酶切加工 (前体蛋白早成熟化)。干扰HIV-1蛋白酶活性的调控机制, 特异性的激活前体蛋白中的蛋白酶, 诱导前体蛋白早成熟化, 就可以直接抑制病毒的复制。根据这一设想, 运用生物发光共振能量转移技术, 建立细胞水平的HIV-1前体蛋白早成熟化激活剂筛选模型, 并通过3 000个化合物的试验性筛选对筛选模型进行评价。研究结果表明该筛选方法灵敏可靠, 特异性高, 重复性好 (Z' 因子为0.905)。     

Discovery of novel PDE10 inhibitors by a robust homogeneous screening assay

Aim:

To develop a homogeneous assay for high-throughput screening (HTS) of inhibitors of phosphodiesterase 10 (PDE10).

Methods:

Purified human PDE10 enzyme derived from E coli, [³H]-cAMP and yttrium silicate microbeads were used to develop an HTS assay based on the scintillation proximity assay (SPA) technology. This method was applied to a large-scale screening campaign against a diverse compound library and subsequent confirmation studies. Preliminary structure-activity relationship (SAR) studies were initiated through limited structural modifications of the hits.

Results:

The IC₅₀ value of the control compound (papaverine) assessed with the SPA approach was comparable and consistent with that reported in the literature. Signal to background (S/B) ratio and Z'' factor of the assay system were evaluated to be 5.24 and 0.71, respectively. In an HTS campaign of 71 360 synthetic and natural compounds, 67 hits displayed reproducible PDE10 inhibition, of which, 8 were chosen as the scaffold for structural modifications and subsequent SAR analysis.

Conclusion:

The homogeneous PDE10 SPA assay is an efficient and robust tool to screen potential PDE10 inhibitors. Preliminary SAR studies suggest that potent PDE10 inhibitors could be identified and developed through this strategy.     

Performance characteristics of an ELISA screening assay for urinary synthetic cannabinoids

Synthetic cannabinoids are marketed as legal alternatives to cannabis, as routine urine cannabinoid immunoassays do not detect synthetic cannabinoids. Laboratories are challenged to identify these new designer drugs that are widely available and represent a major public health and safety problem. Immunoassay testing offers rapid separation of presumptive positive and negative specimens, prior to more costly and time‐consuming chromatographic confirmation. The Neogen SPICE ELISA kit targets JWH‐018 N‐pentanoic acid as a marker for urinary synthetic cannabinoids. Assay performance was evaluated by analyzing 2469 authentic urine samples with the Neogen immunoassay and liquid chromatography‐tandem mass spectrometry (LC‐MS/MS). Two immunoassay cut‐off concentrations, 5 and 10 µg/L, classified samples as presumptive positive or negative, followed by qualitative LC‐MS/MS confirmation for 29 synthetic cannabinoids markers with limits of detection of 0.5–10 µg/L to determine the assay's sensitivity, specificity and efficacy. Challenges at ±25% of each cut‐off also were investigated to determine performance around the cut‐off and intra‐ and inter‐plate imprecision. The immunoassay was linear from 1 to 250 µg/L (r² = 0.992) with intra‐ and inter‐plate imprecision of ≤5.3% and <9%, respectively. Sensitivity, specificity, and efficiency results with the 5 µg/L cut‐off were 79.9%, 99.7%, and 97.4% and with the 10 µg/L cut‐off 69.3%, 99.8%, and 96.3%, respectively. Cross‐reactivity was shown for 18 of 73 synthetic cannabinoids markers evaluated. Good sensitivity, specificity, and efficiency, lack of sample preparation requirements, and rapid semi‐automation documented that the Neogen SPICE ELISA kit is a viable method for screening synthetic cannabinoids in urine targeting JWH‐018 N‐pentanoic acid. Copyright © 2014 John Wiley & Sons, Ltd.     

一种用微孔板筛选alpha-葡萄糖苷酶抑制剂的方法

目的：建立敏感的微孔板方法检测alpha-葡萄糖苷酶抑制活性，以进行抑制剂体外高通量筛选。方法：调整酶和底物适当配比，通过标准曲线、波长扫描、动力学分析以及最佳反应条件的研究，用阿卡波糖验证所建方法。结果：确定反应步骤，96孔板，160μl体系含2．5mmol·L~(-1)PNPG和0．2U·ml~(-1)alpha-葡萄糖苷酶，37℃，pH7．0反应15min，400 nm检测，此法正确、可靠。结论：本文所述用小体积样品筛选得到大量抑制剂的方法，利于从天然产物中开发改善餐后血糖的糖尿病及其并发症治疗药物。     

酶抑制剂类抗糖尿病药物的分子水平筛选方法研究进展

酶抑制剂类抗糖尿病药物是目前药物研究的热点,而药物筛选技术是制约此类抗糖尿病新药研发速度的关键步骤。主要从分子水平总结近年来报道的与糖尿病相关的酶抑制剂类候选药物的筛选方法,包括传统方法和前沿方法,着重介绍极具潜力的毛细管电泳法、质谱法、生物传感法和微通道筛选方法等。