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Holme M, Rana S, Barriga HMG, Kauscher U, Brooks NJ, Stevens MM. A Robust Liposomal Platform for Direct Colorimetric Detection of Sphingomyelinase Enzyme and Inhibitors. ACS NANO 2018; 12:8197-8207. [PMID: 30080036 PMCID: PMC6117748 DOI: 10.1021/acsnano.8b03308] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 07/20/2018] [Indexed: 05/23/2023]
Abstract
The enzyme sphingomyelinase (SMase) is an important biomarker for several diseases such as Niemann Pick's, atherosclerosis, multiple sclerosis, and HIV. We present a two-component colorimetric SMase activity assay that is more sensitive and much faster than currently available commercial assays. Herein, SMase-triggered release of cysteine from a sphingomyelin (SM)-based liposome formulation with 60 mol % cholesterol causes gold nanoparticle (AuNP) aggregation, enabling colorimetric detection of SMase activities as low as 0.02 mU/mL, corresponding to 1.4 pM concentration. While the lipid composition offers a stable, nonleaky liposome platform with minimal background signal, high specificity toward SMase avoids cross-reactivity of other similar phospholipases. Notably, use of an SM-based liposome formulation accurately mimics the natural in vivo substrate: the cell membrane. We studied the physical rearrangement process of the lipid membrane during SMase-mediated hydrolysis of SM to ceramide using small- and wide-angle X-ray scattering. A change in lipid phase from a liquid to gel state bilayer with increasing concentration of ceramide accounts for the observed increase in membrane permeability and consequent release of encapsulated cysteine. We further demonstrated the effectiveness of the sensor in colorimetric screening of small-molecule drug candidates, paving the way for the identification of novel SMase inhibitors in minutes. Taken together, the simplicity, speed, sensitivity, and naked-eye readout of this assay offer huge potential in point-of-care diagnostics and high-throughput drug screening.
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Affiliation(s)
- Margaret
N. Holme
- Department
of Materials, Imperial College London, London, SW7 2AZ, U.K.
- Department of Bioengineering and Institute of Biomedical
Engineering, Imperial College London, London, SW7 2AZ, U.K.
- Department
of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Subinoy Rana
- Department
of Materials, Imperial College London, London, SW7 2AZ, U.K.
- Department of Bioengineering and Institute of Biomedical
Engineering, Imperial College London, London, SW7 2AZ, U.K.
- School
of Engineering, Newcastle University, Newcastle upon Tyne, NE1
7RU, U.K.
| | - Hanna M. G. Barriga
- Department
of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Ulrike Kauscher
- Department
of Materials, Imperial College London, London, SW7 2AZ, U.K.
- Department of Bioengineering and Institute of Biomedical
Engineering, Imperial College London, London, SW7 2AZ, U.K.
| | | | - Molly M. Stevens
- Department
of Materials, Imperial College London, London, SW7 2AZ, U.K.
- Department of Bioengineering and Institute of Biomedical
Engineering, Imperial College London, London, SW7 2AZ, U.K.
- Department
of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-171 77 Stockholm, Sweden
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Sun W, He S, Martínez-Romero C, Kouznetsova J, Tawa G, Xu M, Shinn P, Fisher E, Long Y, Motabar O, Yang S, Sanderson PE, Williamson PR, García-Sastre A, Qiu X, Zheng W. Synergistic drug combination effectively blocks Ebola virus infection. Antiviral Res 2017; 137:165-172. [PMID: 27890675 PMCID: PMC5182099 DOI: 10.1016/j.antiviral.2016.11.017] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 11/21/2016] [Accepted: 11/24/2016] [Indexed: 11/24/2022]
Abstract
Although a group of FDA-approved drugs were previously identified with activity against Ebola virus (EBOV), most of them are not clinically useful because their human blood concentrations are not high enough to inhibit EBOV infection. We screened 795 unique three-drug combinations in an EBOV entry assay. Two sets of three-drug combinations, toremifene-mefloquine-posaconazole and toremifene-clarithromycin-posaconazole, were identified that effectively blocked EBOV entry and were further validated for inhibition of live EBOV infection. The individual drug concentrations in the combinations were reduced to clinically relevant levels. We identified mechanisms of action of these drugs: functional inhibitions of Niemann-Pick C1, acid sphingomyelinase, and lysosomal calcium release. Our findings identify the drug combinations with potential to treat EBOV infection.
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Affiliation(s)
- Wei Sun
- National Center for Advancing Translational Sciences, National Institutes of Health, 9800 Medical Center Drive, Bethesda MD 20892, USA
| | - Shihua He
- Special Pathogens Program, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba R3E 3R2, Canada
- Department of Medical Microbiology, University of Manitoba, Winnipeg, Manitoba R3E 0J9, Canada
| | - Carles Martínez-Romero
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Jennifer Kouznetsova
- National Center for Advancing Translational Sciences, National Institutes of Health, 9800 Medical Center Drive, Bethesda MD 20892, USA
| | - Gregory Tawa
- National Center for Advancing Translational Sciences, National Institutes of Health, 9800 Medical Center Drive, Bethesda MD 20892, USA
| | - Miao Xu
- National Center for Advancing Translational Sciences, National Institutes of Health, 9800 Medical Center Drive, Bethesda MD 20892, USA
| | - Paul Shinn
- National Center for Advancing Translational Sciences, National Institutes of Health, 9800 Medical Center Drive, Bethesda MD 20892, USA
| | - Ethan Fisher
- National Center for Advancing Translational Sciences, National Institutes of Health, 9800 Medical Center Drive, Bethesda MD 20892, USA
| | - Yan Long
- National Center for Advancing Translational Sciences, National Institutes of Health, 9800 Medical Center Drive, Bethesda MD 20892, USA
| | - Omid Motabar
- National Center for Advancing Translational Sciences, National Institutes of Health, 9800 Medical Center Drive, Bethesda MD 20892, USA
| | - Shu Yang
- National Center for Advancing Translational Sciences, National Institutes of Health, 9800 Medical Center Drive, Bethesda MD 20892, USA
| | - Philip E. Sanderson
- National Center for Advancing Translational Sciences, National Institutes of Health, 9800 Medical Center Drive, Bethesda MD 20892, USA
| | - Peter R. Williamson
- Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Adolfo García-Sastre
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Department of Medicine, Division of Infectious Diseases, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Xiangguo Qiu
- Special Pathogens Program, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba R3E 3R2, Canada
- Department of Medical Microbiology, University of Manitoba, Winnipeg, Manitoba R3E 0J9, Canada
| | - Wei Zheng
- National Center for Advancing Translational Sciences, National Institutes of Health, 9800 Medical Center Drive, Bethesda MD 20892, USA
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3
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Mashhadi Akbar Boojar M, Hassanipour M, Ejtemaei Mehr S, Mashhadi Akbar Boojar M, Dehpour AR. New Aspects of Silibinin Stereoisomers and their 3-O-galloyl Derivatives on Cytotoxicity and Ceramide Metabolism in Hep G 2 hepatocarcinoma Cell Line. IRANIAN JOURNAL OF PHARMACEUTICAL RESEARCH : IJPR 2016; 15:421-433. [PMID: 27980577 PMCID: PMC5149029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Ceramide as a second messenger is a key regulator in apoptosis and cytotoxicity. Ceramide-metabolizing enzymes are ideal target in cancer chemo-preventive studies. Neutral sphingomyelinase (NSMase), acid ceramidase (ACDase) and glucosyl ceramide synthase (GCS) are the main enzymes in ceramide metabolism. Silymarin flavonolignans are potent apoptosis inducers and silibinin is the most active component of silymarin. This study evaluated the effects of silybin A, silybin B and their 3-O-gallyl derivatives (SGA and SGB) at different concentrations (0-200 micro molar) on ceramide metabolism enzymes in Hep G2 hepatocarcinoma cell line. Cell viability, caspase-3 and 9 activities, total cell ceramide and the activities of ACDase, NSMase and GCS were evaluated. Under silibinin derivatives treatments, cell viability decreased and the activities of caspase-3 and 9 increased in a dose dependent manner among which SGB was the most effective one (P<0.05). Total cell ceramide and the activity of NSMase, the enzyme which elevates ceramide level, increased by silibinin derivatives. Furthermore, the activities of removing ceramide enzymes (ACDase and GCS) decreased efficiently. The galloyl esterification increased the activity of silibinin isomers. Consequently, this study reveals new sibilinin effects on ceramide metabolism and potential strategies to enhance the antineoplastic properties of this compound.
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Affiliation(s)
- Mahdi Mashhadi Akbar Boojar
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran.
| | - Mahsa Hassanipour
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran.
- Department of Physiology and Pharmacology, School of Medicine, Rafsanjan University of Medical Sciences, Kerman, Iran.
| | - Shahram Ejtemaei Mehr
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran.
| | | | - Ahmad Reza Dehpour
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran.
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Class B, Thorne N, Aguisanda F, Southall N, McKew JC, Zheng W. High-throughput viability assay using an autonomously bioluminescent cell line with a bacterial Lux reporter. ACTA ACUST UNITED AC 2014; 20:164-74. [PMID: 25447977 DOI: 10.1177/2211068214560608] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Cell viability assays are extensively used to determine cell health, evaluate growth conditions, and assess compound cytotoxicity. Most existing assays are endpoint assays, in which data are collected at one time point after termination of the experiment. The time point at which toxicity of a compound is evident, however, depends on the mechanism of that compound. An ideal cell viability assay allows the determination of compound toxicity kinetically without having to terminate the assay prematurely. We optimized and validated a reagent-addition-free cell viability assay using an autoluminescent HEK293 cell line that stably expresses bacterial luciferase and all substrates necessary for bioluminescence. This cell viability assay can be used for real-time, long-term measurement of compound cytotoxicity in live cells with a signal-to-basal ratio of 20- to 200-fold and Z-factors of ~0.6 after 24-, 48- 72-, or 96-h incubation with compound. We also found that the potencies of nine cytotoxic compounds correlated well with those measured by four other commonly used cell viability assays. The results demonstrated that this kinetic cell viability assay using the HEK293(lux) autoluminescent cell line is useful for high-throughput evaluation of compound cytotoxicity.
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Affiliation(s)
- Bradley Class
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, USA
| | - Natasha Thorne
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, USA
| | - Francis Aguisanda
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, USA
| | - Noel Southall
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, USA
| | - John C McKew
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, USA
| | - Wei Zheng
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, USA
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Dehdashti SJ, Abbott J, Nguyen DT, McKew JC, Williamson PR, Zheng W. A high-throughput screening assay for assessing the viability of Cryptococcus neoformans under nutrient starvation conditions. Anal Bioanal Chem 2013; 405:6823-9. [PMID: 23812880 DOI: 10.1007/s00216-013-7134-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 05/22/2013] [Accepted: 06/10/2013] [Indexed: 01/13/2023]
Abstract
Cryptococcus neoformans causes an estimated 600,000 AIDS-related deaths annually that occur primarily in resource-limited countries. Fluconazole and amphotericin B are currently available for the treatment of cryptococcal-related infections. However, fluconazole has limited clinical efficacy and amphotericin B requires intravenous infusion and is associated with high renal toxicity. Therefore, there is an unmet need for a new orally administrable anti-cryptococcal drug. We have developed a high-throughput screening assay for the measurement of C. neoformans viability in 1,536-well plate format. The signal-to-basal ratio of the ATP content assay was 21.9 fold with a coefficient of variation and Z' factor of 7.1% and 0.76, respectively. A pilot screen of 1,280 known compounds against the wild-type C. neoformans (strain H99) led to the identification of four active compounds including niclosamide, malonoben, 6-bromoindirubin-3'-oxime, and 5-[(4-ethylphenyl)methylene]-2-thioxo-4-thiazolidinone. These compounds were further tested against nine clinical isolates of C. neoformans, and their fungicidal activities were confirmed. The results demonstrate that this miniaturized C. neoformans assay is advantageous for the high-throughput screening of large compound collections to identify lead compounds for new anti-cryptococcal drug development.
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Affiliation(s)
- Seameen J Dehdashti
- National Center for Advancing Translational Sciences, National Institute of Health, 9800 Medical Center Drive, MSC: 3370, Bethesda, MD 20892-3370, USA
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