scholarly journals A Dual-reporter Platform for Screening Tumor-targeted Extracellular Vesicles

2021 ◽  
Author(s):  
Masamitsu Kanada ◽  
Lauren Linenfelser ◽  
Elyssa Cox ◽  
Assaf Gilad
Keyword(s):  
Cellular Uptake ◽  
High Throughput Screening ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Fluorescence Analysis ◽  
Extracellular Vesicle ◽  
Dual Reporter ◽  
Binding Peptides ◽  
Tumor Homing ◽  
Homing Peptide

Extracellular vesicle (EV)-mediated transfer of biomolecules plays an essential role in intercellular communication and may improve targeted drug delivery. In the past decade, various approaches to EV surface modification for targeting specific cells or tissues have been proposed, including genetic engineering of parental cells or postproduction EV engineering. However, due to technical limitations, targeting moieties of engineered EVs have not been thoroughly characterized. Here, we report the bioluminescence resonance energy transfer (BRET) EV reporter, PalmReNL-based dual-reporter platform for characterizing the cellular uptake of tumor homing peptide (THP)-engineered EVs, targeting PDL1, uPAR, or EGFR proteins expressed in MDA-MB-231 breast cancer cells, simultaneously by bioluminescence measurement and fluorescence microscopy. Bioluminescence analysis of cellular EV uptake revealed the highest binding efficiency of uPAR-targeted EVs, whereas PDL1-targeted EVs showed slower cellular uptake. EVs engineered with two known EGFR-binding peptides via lipid nanoprobes did not increase cellular uptake, indicating that designs of EGFR-binding peptide conjugation to the EV surface are critical for functional EV engineering. Fluorescence analysis of cellular EV uptake allowed us to track individual PalmReNL-EVs bearing THPs in recipient cells. These results demonstrate that the PalmReNL-based EV assay platform can be a foundation for high-throughput screening of tumor-targeted EVs.

scholarly journals Repurposing a Histamine Detection Platform for High-Throughput Screening of Histidine Decarboxylase

2018 ◽  
Vol 23 (9) ◽  
pp. 974-981
Author(s):  
Yu-Chi Juang ◽  
Xavier Fradera ◽  
Yongxin Han ◽  
Anthony William Partridge
Keyword(s):  
High Throughput ◽  
High Throughput Screening ◽  
Large Scale ◽  
Histidine Decarboxylase ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Gastric Ulcers ◽  
Statistical Parameters ◽  
Time Resolved ◽  
Neurological Response

Histidine decarboxylase (HDC) is the primary enzyme that catalyzes the conversion of histidine to histamine. HDC contributes to many physiological responses as histamine plays important roles in allergic reaction, neurological response, gastric acid secretion, and cell proliferation and differentiation. Small-molecule modulation of HDC represents a potential therapeutic strategy for a range of histamine-associated diseases, including inflammatory disease, neurological disorders, gastric ulcers, and select cancers. High-throughput screening (HTS) methods for measuring HDC activity are currently limited. Here, we report the development of a time-resolved fluorescence resonance energy transfer (TR-FRET) assay for monitoring HDC activity. The assay is based on competition between HDC-generated histamine and fluorophore-labeled histamine for binding to a Europium cryptate (EuK)-labeled anti-histamine antibody. We demonstrated that the assay is highly sensitive and simple to develop. Assay validation experiments were performed using low-volume 384-well plates and resulted in good statistical parameters. A pilot HTS screen gave a Z′ score > 0.5 and a hit rate of 1.1%, and led to the identification of a validated hit series. Overall, the presented assay should facilitate the discovery of therapeutic HDC inhibitors by acting as a novel tool suitable for large-scale HTS and subsequent interrogation of compound structure–activity relationships.

High-throughput screening of TRPV1 ligands in the light of the Bioluminescence Resonance Energy Transfer technique

2021 ◽  
pp. MOLPHARM-AR-2021-000271
Author(s):  
Yann Chappe ◽  
Pauline Michel ◽  
Alexandre Joushomme ◽  
Solène Barbeau ◽  
Sandra Pierredon ◽  
...  
Keyword(s):  
Energy Transfer ◽  
High Throughput ◽  
High Throughput Screening ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Bioluminescence Resonance Energy Transfer

scholarly journals Assay Concordance between SPA and TR-FRET in High-Throughput Screening

2006 ◽  
Vol 11 (6) ◽  
pp. 606-616 ◽  
Author(s):  
Oliver Von Ahsen ◽  
Anne Schmidt ◽  
Monika Klotz ◽  
Karsten Parczyk
Keyword(s):  
High Throughput ◽  
High Throughput Screening ◽  
Statistical Significance ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Time Resolved ◽  
Detection Technology ◽  
Significant Difference ◽  
Set Up ◽  
Detection Technologies

High-throughput screening (HTS) of large chemical libraries has become the main source of new lead compounds for drug development. Several specialized detection technologies have been developed to facilitate the cost- and time-efficient screening of millions of compounds. However, concerns have been raised, claiming that different HTS technologies may produce different hits, thus limiting trust in the reliability of HTS data. This study was aimed to investigate the reliability of the authors most frequently used assay techniques: scintillation proximity assay (SPA) and homogeneous time-resolved fluorescence resonance energy transfer (TR-FRET). To investigate the data concordance between these 2 detection technologies, the authors screened a large subset of the Schering compound library consisting of 300,000 compounds for inhibitors of a nonreceptor tyrosine kinase. They chose to set up this study in realistic HTS scale to ensure statistical significance of the results. The findings clearly demonstrate that the choice of detection technology has no significant impact on hit finding, provided that assays are biochemically equivalent. Data concordance is up to 90%. The little differences in hit findings are caused by threshold setting but not by systematic differences between the technologies. The most significant difference between the compared techniques is that in the SPA format, more false-positive primary hits were obtained.

scholarly journals A High-Throughput Fluorescence Resonance Energy Transfer-Based Assay for DNA Ligase

2011 ◽  
Vol 16 (5) ◽  
pp. 486-493 ◽  
Author(s):  
Adam B. Shapiro ◽  
Ann E. Eakin ◽  
Grant K. Walkup ◽  
Olga Rivin
Keyword(s):  
Energy Transfer ◽  
Fluorescence Resonance Energy Transfer ◽  
High Throughput ◽  
High Throughput Screening ◽  
Pathogenic Bacteria ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Dna Ligase ◽  
Phosphodiester Bond ◽  
Fluorescence Resonance

DNA ligase is the enzyme that catalyzes the formation of the backbone phosphodiester bond between the 5′-PO4 and 3′-OH of adjacent DNA nucleotides at single-stranded nicks. These nicks occur between Okazaki fragments during replication of the lagging strand of the DNA as well as during DNA repair and recombination. As essential enzymes for DNA replication, the NAD+-dependent DNA ligases of pathogenic bacteria are potential targets for the development of antibacterial drugs. For the purposes of drug discovery, a high-throughput assay for DNA ligase activity is invaluable. This article describes a straightforward, fluorescence resonance energy transfer–based DNA ligase assay that is well suited for high-throughput screening for DNA ligase inhibitors as well as for use in enzyme kinetics studies. Its use is demonstrated for measurement of the steady-state kinetic constants of Haemophilus influenzae NAD+-dependent DNA ligase and for measurement of the potency of an inhibitor of this enzyme.

scholarly journals Alteration of RNA Splicing by Small-Molecule Inhibitors of the Interaction between NHP2L1 and U4

2017 ◽  
Vol 23 (2) ◽  
pp. 164-173 ◽  
Author(s):  
Barthelemy Diouf ◽  
Wenwei Lin ◽  
Asli Goktug ◽  
Christy R. R. Grace ◽  
Michael Brett Waddell ◽  
...  
Keyword(s):  
Small Molecules ◽  
Rna Splicing ◽  
High Throughput Screening ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Therapeutic Strategies ◽  
Biological Processes ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
U4 Rna

Splicing is an important eukaryotic mechanism for expanding the transcriptome and proteome, influencing a number of biological processes. Understanding its regulation and identifying small molecules that modulate this process remain a challenge. We developed an assay based on time-resolved fluorescence resonance energy transfer (TR-FRET) to detect the interaction between the protein NHP2L1 and U4 RNA, which are two key components of the spliceosome. We used this assay to identify small molecules that interfere with this interaction in a high-throughput screening (HTS) campaign. Topotecan and other camptothecin derivatives were among the top hits. We confirmed that topotecan disrupts the interaction between NHP2L1 and U4 by binding to U4 and inhibits RNA splicing. Our data reveal new functions of known drugs that could facilitate the development of therapeutic strategies to modify splicing and alter gene function.

scholarly journals Thermally Denatured BSA, a Surrogate Additive to Replace BSA in Buffers for High-Throughput Screening

2010 ◽  
Vol 15 (10) ◽  
pp. 1281-1286 ◽  
Author(s):  
Imanol Peña ◽  
Juan Manuel Domínguez
Keyword(s):  
High Throughput ◽  
High Throughput Screening ◽  
Negative Impact ◽  
Specific Binding ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Masking Effect ◽  
Binding Properties ◽  
Time Resolved ◽  
Beneficial Effects

The use of thermally denatured bovine serum albumin (tdBSA) as an additive in high-throughput screening (HTS) buffers has been studied with the aim of finding a surrogate to native albumin devoid of its inconveniences, in particular its compound masking effect. The presence of aggregates in the thermally denatured material did not have any negative impact on common readout technologies used in HTS such as fluorescence intensity (FLINT), fluorescence polarization, time-resolved fluorescence resonance energy transfer (TR-FRET) and luminescence. tdBSA rendered the same beneficial effects as native albumin in several assays or even improved its performance due to the lack of specific binding properties. Although tdBSA still binds compounds nonspecifically as any other protein does, it mitigates the compound masking effect observed with native albumin and can be postulated as a convenient surrogate to BSA for HTS purposes.

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