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A Bioassay Using a Pentadecanal Derivative to Measure S1P Lyase Activity. Int J Mol Sci 2021; 22:ijms22031438. [PMID: 33535437 PMCID: PMC7867068 DOI: 10.3390/ijms22031438] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Revised: 01/23/2021] [Accepted: 01/25/2021] [Indexed: 01/02/2023] Open
Abstract
Sphingosine-1-phosphate (S1P) is a unique lipid ligand binding to S1P receptors to transduce various cell survival or proliferation signals via small G proteins. S1P lyase (S1PL) is the specific enzyme that degrades S1P to phosphoethanolamine and (2E)-hexadecenal and therefore regulates S1P levels. S1PL also degrades dihydrosphingosine-1-phosphate (Sa1P), with a higher affinity to produce hexadecanal. Here, we developed a newly designed assay using a C17-Sa1P substrate that degrades into pentadecanal and phosphoethanolamine. For higher sensitivity in pentadecanal analysis, we developed a quantitative protocol as well as a 5,5-dimethyl cyclohexanedione (5,5-dimethyl CHD) derivatization method. The derivatization conditions were optimized for the reaction time, temperature, and concentrations of the 5,5-dimethyl CHD reagent, acetic acid, and ammonium acetate. The S1PL reaction in the cell lysate after spiking 20 µM of C17-Sa1P for 20 min was linear to the total protein concentrations of 50 µg. The S1PL levels (4 pmol/mg/min) were readily detected in this HPLC with fluorescence detection (λex = 366 nm, λem = 455 nm). The S1PL-catalyzed reaction was linear over 30 min and yielded a Km value of 2.68 μM for C17-Sa1P. This new method was validated to measure the S1PL activity of mouse embryonal carcinoma cell lines of the standard cell (F9-0), S1PL knockdown cells (F9-2), and S1PL-overexpressed cells (F9-4). Furthermore, we treated F9-4 cells with different S1PL inhibitors such as FTY720, 4-deoxypyridoxine (DOP), and the deletion of pyridoxal-5-phosphate (P5P), an essential cofactor for S1PL activity, and observed a significant decrease in pentadecanal relative to the untreated cells. In conclusion, we developed a highly sensitive S1PL assay using a C17-Sa1P substrate for pentadecanal quantification for application in the characterization of S1PL activity in vitro.
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Lee SY, Lim JC, Cho EH, Lee SK, Jung SH. Ultrasound-enhanced scintillation proximity assay for rapid diagnostics. Anal Biochem 2019; 570:51-55. [PMID: 30771337 DOI: 10.1016/j.ab.2019.02.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 02/11/2019] [Accepted: 02/12/2019] [Indexed: 11/15/2022]
Abstract
Scintillation proximity assay (SPA) is a type of radioimmunoassay (RIA). We apply ultrasound enhancement to the general SPA. All assay procedures, including the antibody coating and radiolabeled antigen binding are achieved by simply mixing then standing for 5 min in an ultrasound chamber. No additional incubation time is required. To further demonstrate the capability of the UE-SPA, a quantitative measurement of CD55 in various grades of colon tumors was assessed on human tissue slides. The results showed a significant correlation between CD55 expression and tumorigenesis. In conclusion, we confirmed that UE-SPA is a reliable, rapid and alternative to RIA.
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Affiliation(s)
- So-Young Lee
- Radioisotope Research Division, Korea Atomic Energy Research Institute (KAERI), Daejeon, 305-353, Republic of Korea.
| | - Jae-Cheong Lim
- Radioisotope Research Division, Korea Atomic Energy Research Institute (KAERI), Daejeon, 305-353, Republic of Korea
| | - Eun-Ha Cho
- Radioisotope Research Division, Korea Atomic Energy Research Institute (KAERI), Daejeon, 305-353, Republic of Korea
| | - Seung-Kon Lee
- Radioisotope Research Division, Korea Atomic Energy Research Institute (KAERI), Daejeon, 305-353, Republic of Korea
| | - Sung-Hee Jung
- Radioisotope Research Division, Korea Atomic Energy Research Institute (KAERI), Daejeon, 305-353, Republic of Korea
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S1P Lyase Regulation of Thymic Egress and Oncogenic Inflammatory Signaling. Mediators Inflamm 2017; 2017:7685142. [PMID: 29333002 PMCID: PMC5733215 DOI: 10.1155/2017/7685142] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 09/13/2017] [Indexed: 12/17/2022] Open
Abstract
Sphingosine-1-phosphate (S1P) is a potent lipid signaling molecule that regulates pleiotropic biological functions including cell migration, survival, angiogenesis, immune cell trafficking, inflammation, and carcinogenesis. It acts as a ligand for a family of cell surface receptors. S1P concentrations are high in blood and lymph but low in tissues, especially the thymus and lymphoid organs. S1P chemotactic gradients are essential for lymphocyte egress and other aspects of physiological cell trafficking. S1P is irreversibly degraded by S1P lyase (SPL). SPL regulates lymphocyte trafficking, inflammation and other physiological and pathological processes. For example, SPL located in thymic dendritic cells acts as a metabolic gatekeeper that controls the normal egress of mature T lymphocytes from the thymus into the circulation, whereas SPL deficiency in gut epithelial cells promotes colitis and colitis-associated carcinogenesis (CAC). Recently, we identified a complex syndrome comprised of nephrosis, adrenal insufficiency, and immunological defects caused by inherited mutations in human SGPL1, the gene encoding SPL. In the present article, we review current evidence supporting the role of SPL in thymic egress, inflammation, and cancer. Lastly, we summarize recent progress in understanding other SPL functions, its role in inherited disease, and SPL targeting for therapeutic purposes.
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Development of a Novel High-Density [3H]Hypoxanthine Scintillation Proximity Assay To Assess Plasmodium falciparum Growth. Antimicrob Agents Chemother 2016; 60:5949-56. [PMID: 27458216 DOI: 10.1128/aac.00433-16] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 07/09/2016] [Indexed: 12/30/2022] Open
Abstract
The 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-cell in vitro potencies of antimalarial hits. The [(3)H]hypoxanthine incorporation assay is considered the "gold standard" assay for measurement of the activity of antimalarial compounds against intraerythrocytic forms of Plasmodium 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 [(3)H]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 the P. falciparum lactate 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 [(3)H]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.
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Scintillation Proximity Assay to Detect the Changes in Cellular Dihydrosphingosine 1-Phosphate Levels. Lipids 2016; 51:1207-1216. [PMID: 27585475 DOI: 10.1007/s11745-016-4187-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 08/15/2016] [Indexed: 10/21/2022]
Abstract
Compounds that modulate the activity of sphingosine 1-phosphate (S1P)-metabolizing enzymes are expected to be potential therapeutic agents for various diseases. Investigation of their potencies requires not only cell-free but also cell-based assays in which intracellular accumulation/depletion of S1P could be monitored. However, conventional methods have limitations to their simplicity, mainly due to the necessity of a separation process that separates S1P from its related substances. Here, we describe a method utilizing a scintillation proximity assay (SPA) for semi-quantifying intracellular [(3)H]-labeled dihydroS1P ([(3)H]dhS1P), which is also a substrate for S1P-metabolizing enzymes. We found that uncoated yttrium silicate SPA beads could selectively bind to and detect [(3)H]dhS1P rather than [(3)H]dihydrosphingosine (the non-phosphorylated form of [(3)H]dhS1P). Based on this, we developed a novel cell-based assay system which does not require any organic solvent extraction or chromatographic separation, and confirmed its practicality by using siRNA targeting S1P lyase (S1PL) and known S1PL inhibitors as models. Our results demonstrated that this assay is useful for rapid and easy evaluation of S1PL inhibitors, and could be potentially applicable for all compounds that modulate the activity of S1P-metabolizing enzymes.
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Sanllehí P, Abad JL, Casas J, Bujons J, Delgado A. Bacterial versus human sphingosine-1-phosphate lyase (S1PL) in the design of potential S1PL inhibitors. Bioorg Med Chem 2016; 24:4381-4389. [DOI: 10.1016/j.bmc.2016.07.033] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 07/13/2016] [Accepted: 07/16/2016] [Indexed: 12/28/2022]
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High-throughput platforms for the screening of new therapeutic targets for neurodegenerative diseases. Drug Discov Today 2016; 21:1355-1366. [PMID: 27178019 DOI: 10.1016/j.drudis.2016.05.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 04/01/2016] [Accepted: 05/04/2016] [Indexed: 12/13/2022]
Abstract
Despite the recent progress in the understanding of neurodegenerative disorders, a lack of solid fundamental knowledge on the etiology of many of the major neurodegenerative diseases has made it difficult to obtain effective therapies to treat these conditions. Scientists have been looking to carry out more-human-relevant studies, with strong statistical power, to overcome the limitations of preclinical animal models that have contributed to the failure of numerous therapeutics in clinical trials. Here, we identify currently existing platforms to mimic central nervous system tissues, healthy and diseased, mainly focusing on cell-based platforms and discussing their strengths and limitations in the context of the high-throughput screening of new therapeutic targets and drugs.
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Dinges J, Harris CM, Wallace GA, Argiriadi MA, Queeney KL, Perron DC, Dominguez E, Kebede T, Desino KE, Patel H, Vasudevan A. Hit-to-lead evaluation of a novel class of sphingosine 1-phosphate lyase inhibitors. Bioorg Med Chem Lett 2016; 26:2297-302. [DOI: 10.1016/j.bmcl.2016.03.043] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 03/11/2016] [Accepted: 03/12/2016] [Indexed: 01/21/2023]
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Kashem MA, Kennedy CA, Fogarty KE, Dimock JR, Zhang Y, Sanville-Ross ML, Skow DJ, Brunette SR, Swantek JL, Hummel HS, Swindle J, Nelson RM. A High-Throughput Genetic Complementation Assay in Yeast Cells Identified Selective Inhibitors of Sphingosine Kinase 1 Not Found Using a Cell-Free Enzyme Assay. Assay Drug Dev Technol 2016; 14:39-49. [DOI: 10.1089/adt.2015.671] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Affiliation(s)
- Mohammed A. Kashem
- Small Molecule Discovery Research, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, Connecticut
| | - Charles A. Kennedy
- Small Molecule Discovery Research, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, Connecticut
| | - Kylie E. Fogarty
- Small Molecule Discovery Research, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, Connecticut
| | - Janice R. Dimock
- Immunology and Respiratory Research, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, Connecticut
| | - Yunlong Zhang
- Small Molecule Discovery Research, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, Connecticut
| | - Mary L. Sanville-Ross
- Small Molecule Discovery Research, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, Connecticut
| | - Donna J. Skow
- Small Molecule Discovery Research, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, Connecticut
| | - Steven R. Brunette
- Small Molecule Discovery Research, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, Connecticut
| | - Jennifer L. Swantek
- Immunology and Respiratory Research, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, Connecticut
| | | | | | - Richard M. Nelson
- Small Molecule Discovery Research, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, Connecticut
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Klumpp M. Non-stoichiometric inhibition in integrated lead finding - a literature review. Expert Opin Drug Discov 2015; 11:149-62. [PMID: 26653534 DOI: 10.1517/17460441.2016.1128892] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
INTRODUCTION Non-stoichiometric inhibition summarizes different mechanisms by which low-molecular weight compounds can reproducibly inhibit high-throughput screening (HTS) and other lead finding assays without binding to a structurally defined site on their molecular target. This disqualifies such molecules from optimization by medicinal chemistry, and therefore their rapid elimination from screening hit lists is essential for productive and effective drug discovery. AREAS COVERED This review covers recent literature that either investigates the various mechanisms behind non-stoichiometric inhibition or suggests assays and readouts to identify them. In addition, combination of the various methods to distill promising molecules out of raw primary hit lists step-by-step is considered. Emerging technologies to demonstrate target engagement in cells are also discussed. EXPERT OPINION Over the last few years, awareness of non-stoichiometric inhibitors within screening libraries and HTS hit lists has considerably increased, not only in the pharmaceutical industry but also in the academic drug discovery community. This has resulted in a variety of methods to detect and handle such compounds. These range from in silico approaches to flag suspicious compounds, and counterassays to measure non-stoichiometric inhibition, to biophysical methods that positively demonstrate stoichiometric binding. In addition, novel technologies to verify target engagement within cells are becoming available. While still a time- and resource-consuming nuisance, non-stoichiometric inhibitors therefore do not fundamentally jeopardize the discovery of low molecular weight lead and drug candidates. Rather, they should be viewed as a manageable issue that with appropriate expertise can be overcome through integration of the above-mentioned approaches.
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Affiliation(s)
- Martin Klumpp
- a Novartis Institute of Biomedical Research Basel, Novartis Pharma AG , Basel , Switzerland
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Suh JH, Eltanawy A, Rangan A, Saba JD. A facile stable-isotope dilution method for determination of sphingosine phosphate lyase activity. Chem Phys Lipids 2015; 194:101-9. [PMID: 26408264 DOI: 10.1016/j.chemphyslip.2015.09.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 09/17/2015] [Accepted: 09/21/2015] [Indexed: 01/02/2023]
Abstract
A new technique for quantifying sphingosine phosphate lyase activity in biological samples is described. In this procedure, 2-hydrazinoquinoline is used to convert (2E)-hexadecenal into the corresponding hydrazone derivative to improve ionization efficiency and selectivity of detection. Combined utilization of liquid chromatographic separation and multiple reaction monitoring-mass spectrometry allows for simultaneous quantification of the substrate S1P and product (2E)-hexadecenal. Incorporation of (2E)- d5-hexadecenal as an internal standard improves detection accuracy and precision. A simple one-step derivatization procedure eliminates the need for further extractions. Limits of quantification for (2E)-hexadecenal and sphingosine-1-phosphate are 100 and 50fmol, respectively. The assay displays a wide dynamic detection range useful for detection of low basal sphingosine phosphate lyase activity in wild type cells, SPL-overexpressing cell lines, and wild type mouse tissues. Compared to current methods, the capacity for simultaneous detection of sphingosine-1-phosphate and (2E)-hexadecenal greatly improves the accuracy of results and shows excellent sensitivity and specificity for sphingosine phosphate lyase activity detection.
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Affiliation(s)
- Jung H Suh
- Children's Hospital Oakland Research Institute, UCSF Benioff Children's Hospital Oakland, 5700 Martin Luther King Jr. Way, Oakland, CA 94609, United States
| | - Abeer Eltanawy
- Children's Hospital Oakland Research Institute, UCSF Benioff Children's Hospital Oakland, 5700 Martin Luther King Jr. Way, Oakland, CA 94609, United States
| | - Apoorva Rangan
- Children's Hospital Oakland Research Institute, UCSF Benioff Children's Hospital Oakland, 5700 Martin Luther King Jr. Way, Oakland, CA 94609, United States
| | - Julie D Saba
- Children's Hospital Oakland Research Institute, UCSF Benioff Children's Hospital Oakland, 5700 Martin Luther King Jr. Way, Oakland, CA 94609, United States.
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