scholarly journals Imaging-Based High-Throughput Screening Assay To Identify New Molecules with Transmission-Blocking Potential against Plasmodium falciparum Female Gamete Formation

2015 ◽  
Vol 59 (6) ◽  
pp. 3298-3305 ◽  
Author(s):  
Celia Miguel-Blanco ◽  
Joël Lelièvre ◽  
Michael J. Delves ◽  
Ana I. Bardera ◽  
Jesús L. Presa ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Drug Discovery ◽  
High Throughput ◽  
High Throughput Screening ◽  
Female Gamete ◽  
Transmission Blocking ◽  
Content Type ◽  
Female Gametocyte ◽  
Gamete Formation ◽  
Selection Of

ABSTRACTIn response to a call for the global eradication of malaria, drug discovery has recently been extended to identify compounds that prevent the onward transmission of the parasite, which is mediated byPlasmodium falciparumstage V gametocytes. Lately, metabolic activity has been usedin vitroas a surrogate for gametocyte viability; however, as gametocytes remain relatively quiescent at this stage, their ability to undergo onward development (gamete formation) may be a better measure of their functional viability. During gamete formation, female gametocytes undergo profound morphological changes and express translationally repressed mRNA. By assessing female gamete cell surface expression of one such repressed protein, Pfs25, as the readout for female gametocyte functional viability, we developed an imaging-based high-throughput screening (HTS) assay to identify transmission-blocking compounds. This assay, designated theP. falciparumfemale gametocyte activation assay (FGAA), was scaled up to a high-throughput format (Z′ factor, 0.7 ± 0.1) and subsequently validated using a selection of 50 known antimalarials from diverse chemical families. Only a few of these agents showed submicromolar 50% inhibitory concentrations in the assay: thiostrepton, methylene blue, and some endoperoxides. To determine the best conditions for HTS, a robustness test was performed with a selection of the GlaxoSmithKline Tres Cantos Antimalarial Set (TCAMS) and the final screening conditions for this library were determined to be a 2 μM concentration and 48 h of incubation with gametocytes. TheP. falciparumFGAA has been proven to be a robust HTS assay faithful toPlasmodiumtransmission-stage cell biology, and it is an innovative useful tool for antimalarial drug discovery which aims to identify new molecules with transmission-blocking potential.

scholarly journals Recent Advances in In-Vitro Assays for Type 2 Diabetes Mellitus: An Overview

2020 ◽  
Vol 16 (1) ◽  
pp. 13-23
Author(s):  
Nazmina Vhora ◽  
Ujjal Naskar ◽  
Aishwarya Hiray ◽  
Abhijeet S. Kate ◽  
Alok Jain
Keyword(s):  
Type 2 Diabetes ◽  
Drug Discovery ◽  
High Throughput ◽  
High Throughput Screening ◽  
Antidiabetic Activity ◽  
Screening Methods ◽  
Selection Of

BACKGROUND: A higher rate of attenuation of molecules in drug discovery has enabled pharmaceutical companies to enhance the efficiency of their hit identification and lead optimization. Selection and development of appropriate in-vitro and in-vivo strategies may improve this process as primary and secondary screening utilize both strategies. In-vivo approaches are too relentless and expensive for assessing hits. Therefore, it has become indispensable to develop and implement suitable in-vitro screening methods to execute the required activities and meet the respective targets. However, the selection of an appropriate in-vitro assay for specific evaluation of cellular activity is no trivial task. It requires thorough investigation of the various parameters involved. AIM: In this review, we aim to discuss in-vitro assays for type 2 diabetes (T2D), which have been utilized extensively by researchers over the last five years, including target-based, non-target based, low-throughput, and high-throughput screening assays. METHODS: The literature search was conducted using databases including Scifinder, PubMed, ScienceDirect, and Google Scholar to find the significant published articles. DISCUSSION and CONCLUSION: The accuracy and relevance of in-vitro assays have a significant impact on the drug discovery process for T2D, especially in assessing the antidiabetic activity of compounds and identifying the site of effect in high-throughput screening. The report reviews the advantages, limitations, quality parameters, and applications of the probed invitro assays, and compares them with one another to enable the selection of the optimal method for any purpose. The information on these assays will accelerate numerous procedures in the drug development process with consistent quality and accuracy.

scholarly journals Development of a Novel High-Density [3H]Hypoxanthine Scintillation Proximity Assay To Assess Plasmodium falciparum Growth

2016 ◽  
Vol 60 (10) ◽  
pp. 5949-5956 ◽  
Author(s):  
Cristina de Cózar ◽  
Iván Caballero ◽  
Gonzalo Colmenarejo ◽  
Laura M. Sanz ◽  
Emilio Álvarez-Ruiz ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
High Throughput ◽  
High Throughput Screening ◽  
Cell Activity ◽  
High Density ◽  
Whole Cell ◽  
Content Type ◽  
Scintillation Proximity Assay ◽  
Incorporation Assay ◽  
Incorporation Method

ABSTRACTThe discovery and development of new antimalarial drugs are becoming imperative because of the spread of resistance to current clinical treatments. The lack of robustly validated antimalarial targets and the difficulties with the building in of whole-cell activity in screening hits are hampering target-based approaches. However, phenotypic screens of structurally diverse molecule libraries are offering new opportunities for the identification of novel antimalarials. Several methodologies can be used to determine the whole-cellin vitropotencies of antimalarial hits. The [3H]hypoxanthine incorporation assay is considered the “gold standard” assay for measurement of the activity of antimalarial compounds against intraerythrocytic forms ofPlasmodium falciparum. However, the method has important limitations, as the assay is not amenable for high-throughput screening since it remains associated with the 96-well plate format. We have overcome this drawback by adapting the [3H]hypoxanthine incorporation method to a 384-well high-density format by coupling a homogeneous scintillation proximity assay (SPA) and thus eliminating the limiting filtration step. This SPA has been validated using a diverse set of 1,000 molecules, including both a representative set from the Tres Cantos Antimalarial Set (TCAMS) of compounds and molecules inactive against whole cells. The results were compared with those from theP. falciparumlactate dehydrogenase whole-cell assay, another method that is well established as a surrogate for parasite growth and is amenable for high-throughput screening. The results obtained demonstrate that the SPA-based [3H]hypoxanthine incorporation assay is a suitable design that is adaptable to high-throughput antimalarial drug screening and that maintains the features, robustness, and reliability of the standard filtration hypoxanthine incorporation method.

scholarly journals Identification of Novel Trypanosoma cruzi Proteasome Inhibitors Using a Luminescence-Based High-Throughput Screening Assay

2019 ◽  
Vol 63 (9) ◽  
Author(s):  
Filip Zmuda ◽  
Lalitha Sastry ◽  
Sharon M. Shepherd ◽  
Deuan Jones ◽  
Alison Scott ◽  
...  
Keyword(s):  
Drug Discovery ◽  
Trypanosoma Cruzi ◽  
High Throughput ◽  
High Throughput Screening ◽  
Chemical Space ◽  
Protozoan Parasite ◽  
Current Treatment ◽  
Screening Assay ◽  
Content Type ◽  
High Throughput Screening Assay

ABSTRACT Chagas’ disease, caused by the protozoan parasite Trypanosoma cruzi, is a potentially life-threatening condition that has become a global issue. Current treatment is limited to two medicines that require prolonged dosing and are associated with multiple side effects, which often lead to treatment discontinuation and failure. One way to address these shortcomings is through target-based drug discovery on validated T. cruzi protein targets. One such target is the proteasome, which plays a crucial role in protein degradation and turnover through chymotrypsin-, trypsin-, and caspase-like catalytic activities. In order to initiate a proteasome drug discovery program, we isolated proteasomes from T. cruzi epimastigotes and characterized their activity using a commercially available glow-like luminescence-based assay. We developed a high-throughput biochemical assay for the chymotrypsin-like activity of the T. cruzi proteasome, which was found to be sensitive, specific, and robust but prone to luminescence technology interference. To mitigate this, we also developed a counterscreen assay that identifies potential interferers at the levels of both the luciferase enzyme reporter and the mechanism responsible for a glow-like response. Interestingly, we also found that the peptide substrate for chymotrypsin-like proteasome activity was not specific and was likely partially turned over by other catalytic sites of the protein. Finally, we utilized these biochemical tools to screen 18,098 compounds, exploring diverse drug-like chemical space, which allowed us to identify 39 hits that were active in the primary screening assay and inactive in the counterscreen assay.

Upscaling and Automation of Electrophysiology: Toward High Throughput Screening in Ion Channel Drug Discovery

2003 ◽  
Vol 9 (1) ◽  
pp. 49-58
Author(s):  
Margit Asmild ◽  
Nicholas Oswald ◽  
Karen M. Krzywkowski ◽  
Søren Friis ◽  
Rasmus B. Jacobsen ◽  
...  
Keyword(s):  
Drug Discovery ◽  
Ion Channel ◽  
High Throughput ◽  
High Throughput Screening

High-Throughput Affinity Selection Mass Spectrometry Using SAMDI-MS to Identify Small-Molecule Binders of the Human Rhinovirus 3C Protease

2021 ◽  
pp. 247255522110232
Author(s):  
Michael D. Scholle ◽  
Doug McLaughlin ◽  
Zachary A. Gurard-Levin
Keyword(s):  
Mass Spectrometry ◽  
Drug Discovery ◽  
High Throughput ◽  
High Throughput Screening ◽  
Human Rhinovirus ◽  
Binding Potential ◽  
Affinity Selection ◽  
Response Curves ◽  
Desorption Ionization ◽  
Self Assembled

Affinity selection mass spectrometry (ASMS) has emerged as a powerful high-throughput screening tool used in drug discovery to identify novel ligands against therapeutic targets. This report describes the first high-throughput screen using a novel self-assembled monolayer desorption ionization (SAMDI)–ASMS methodology to reveal ligands for the human rhinovirus 3C (HRV3C) protease. The approach combines self-assembled monolayers of alkanethiolates on gold with matrix-assisted laser desorption ionization time-of-flight (MALDI TOF) mass spectrometry (MS), a technique termed SAMDI-ASMS. The primary screen of more than 100,000 compounds in pools of 8 compounds per well was completed in less than 8 h, and informs on the binding potential and selectivity of each compound. Initial hits were confirmed in follow-up SAMDI-ASMS experiments in single-concentration and dose–response curves. The ligands identified by SAMDI-ASMS were further validated using differential scanning fluorimetry (DSF) and in functional protease assays against HRV3C and the related SARS-CoV-2 3CLpro enzyme. SAMDI-ASMS offers key benefits for drug discovery over traditional ASMS approaches, including the high-throughput workflow and readout, minimizing compound misbehavior by using smaller compound pools, and up to a 50-fold reduction in reagent consumption. The flexibility of this novel technology opens avenues for high-throughput ASMS assays of any target, thereby accelerating drug discovery for diverse diseases.

scholarly journals Development of a Robust High-Throughput Screening Platform for Inhibitors of the Striatal-Enriched Tyrosine Phosphatase (STEP)

2021 ◽  
Vol 22 (9) ◽  
pp. 4417
Author(s):  
Lester J Lambert ◽  
Stefan Grotegut ◽  
Maria Celeridad ◽  
Palak Gosalia ◽  
Laurent JS De Backer ◽  
...  
Keyword(s):  
Drug Discovery ◽  
High Throughput ◽  
Tyrosine Kinases ◽  
High Throughput Screening ◽  
Kinase Inhibitors ◽  
Tyrosine Phosphatase ◽  
Protein Tyrosine Phosphatases ◽  
Synaptic Function ◽  
Label Free ◽  
Protein Tyrosine

Many human diseases are the result of abnormal expression or activation of protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs). Not surprisingly, more than 30 tyrosine kinase inhibitors (TKIs) are currently in clinical use and provide unique treatment options for many patients. PTPs on the other hand have long been regarded as “undruggable” and only recently have gained increased attention in drug discovery. Striatal-enriched tyrosine phosphatase (STEP) is a neuron-specific PTP that is overactive in Alzheimer’s disease (AD) and other neurodegenerative and neuropsychiatric disorders, including Parkinson’s disease, schizophrenia, and fragile X syndrome. An emergent model suggests that the increase in STEP activity interferes with synaptic function and contributes to the characteristic cognitive and behavioral deficits present in these diseases. Prior efforts to generate STEP inhibitors with properties that warrant clinical development have largely failed. To identify novel STEP inhibitor scaffolds, we developed a biophysical, label-free high-throughput screening (HTS) platform based on the protein thermal shift (PTS) technology. In contrast to conventional HTS using STEP enzymatic assays, we found the PTS platform highly robust and capable of identifying true hits with confirmed STEP inhibitory activity and selectivity. This new platform promises to greatly advance STEP drug discovery and should be applicable to other PTP targets.

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