19 results on '"Cauchon E"'
Search Results
2. Discovery of MK-1439, an orally bioavailable non-nucleoside reverse transcriptase inhibitor potent against a wide range of resistant mutant HIV viruses.
- Author
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Côté B, Burch JD, Asante-Appiah E, Bayly C, Bédard L, Blouin M, Campeau LC, Cauchon E, Chan M, Chefson A, Coulombe N, Cromlish W, Debnath S, Deschênes D, Dupont-Gaudet K, Falgueyret JP, Forget R, Gagné S, Gauvreau D, Girardin M, Guiral S, Langlois E, Li CS, Nguyen N, Papp R, Plamondon S, Roy A, Roy S, Seliniotakis R, St-Onge M, Ouellet S, Tawa P, Truchon JF, Vacca J, Wrona M, Yan Y, and Ducharme Y
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- Animals, Anti-HIV Agents chemical synthesis, Anti-HIV Agents chemistry, Cells, Cultured, Crystallography, X-Ray, Dogs, HIV-1 genetics, Humans, Inhibitory Concentration 50, Molecular Structure, Mutation, Rats, Rats, Sprague-Dawley, Reverse Transcriptase Inhibitors chemistry, Anti-HIV Agents pharmacology, Drug Discovery, Drug Resistance, Viral drug effects, HIV-1 drug effects, Pyridones chemistry, Pyridones pharmacology, Reverse Transcriptase Inhibitors chemical synthesis, Reverse Transcriptase Inhibitors pharmacology, Triazoles chemistry, Triazoles pharmacology
- Abstract
The optimization of a novel series of non-nucleoside reverse transcriptase inhibitors (NNRTI) led to the identification of pyridone 36. In cell cultures, this new NNRTI shows a superior potency profile against a range of wild type and clinically relevant, resistant mutant HIV viruses. The overall favorable preclinical pharmacokinetic profile of 36 led to the prediction of a once daily low dose regimen in human. NNRTI 36, now known as MK-1439, is currently in clinical development for the treatment of HIV infection., (Copyright © 2013 Elsevier Ltd. All rights reserved.)
- Published
- 2014
- Full Text
- View/download PDF
3. In vitro characterization of MK-1439, a novel HIV-1 nonnucleoside reverse transcriptase inhibitor.
- Author
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Lai MT, Feng M, Falgueyret JP, Tawa P, Witmer M, DiStefano D, Li Y, Burch J, Sachs N, Lu M, Cauchon E, Campeau LC, Grobler J, Yan Y, Ducharme Y, Côté B, Asante-Appiah E, Hazuda DJ, and Miller MD
- Subjects
- Anti-HIV Agents administration & dosage, Anti-HIV Agents adverse effects, Drug Synergism, HIV Infections drug therapy, HIV Reverse Transcriptase metabolism, HIV-1 enzymology, Humans, In Vitro Techniques, Macrophages drug effects, Monocytes drug effects, Pyridones adverse effects, Triazoles adverse effects, Virus Replication drug effects, Anti-HIV Agents pharmacology, HIV Reverse Transcriptase antagonists & inhibitors, HIV-1 drug effects, Pyridones pharmacology, Triazoles pharmacology
- Abstract
Nonnucleoside reverse transcriptase inhibitors (NNRTIs) are a mainstay of therapy for treating human immunodeficiency type 1 virus (HIV-1)-infected patients. MK-1439 is a novel NNRTI with a 50% inhibitory concentration (IC50) of 12, 9.7, and 9.7 nM against the wild type (WT) and K103N and Y181C reverse transcriptase (RT) mutants, respectively, in a biochemical assay. Selectivity and cytotoxicity studies confirmed that MK-1439 is a highly specific NNRTI with minimum off-target activities. In the presence of 50% normal human serum (NHS), MK-1439 showed excellent potency in suppressing the replication of WT virus, with a 95% effective concentration (EC95) of 20 nM, as well as K103N, Y181C, and K103N/Y181C mutant viruses with EC95 of 43, 27, and 55 nM, respectively. MK-1439 exhibited similar antiviral activities against 10 different HIV-1 subtype viruses (a total of 93 viruses). In addition, the susceptibility of a broader array of clinical NNRTI-associated mutant viruses (a total of 96 viruses) to MK-1439 and other benchmark NNRTIs was investigated. The results showed that the mutant profile of MK-1439 was superior overall to that of efavirenz (EFV) and comparable to that of etravirine (ETR) and rilpivirine (RPV). Furthermore, E138K, Y181C, and K101E mutant viruses that are associated with ETR and RPV were susceptible to MK-1439 with a fold change (FC) of <3. A two-drug in vitro combination study indicated that MK-1439 acts nonantagonistically in the antiviral activity with each of 18 FDA-licensed drugs for HIV infection. Taken together, these in vitro data suggest that MK-1439 possesses the desired properties for further development as a new antiviral agent.
- Published
- 2014
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- View/download PDF
4. Design and synthesis of potent, isoxazole-containing renin inhibitors.
- Author
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Fournier PA, Arbour M, Cauchon E, Chen A, Chefson A, Ducharme Y, Falgueyret JP, Gagné S, Grimm E, Han Y, Houle R, Lacombe P, Lévesque JF, MacDonald D, Mackay B, McKay D, Percival MD, Ramtohul Y, St-Jacques R, and Toulmond S
- Subjects
- Administration, Oral, Animals, Antihypertensive Agents chemical synthesis, Antihypertensive Agents pharmacology, Catalytic Domain, Enzyme Activation drug effects, Humans, Isoxazoles pharmacology, Molecular Structure, Rats, Structure-Activity Relationship, Antihypertensive Agents chemistry, Drug Design, Isoxazoles chemical synthesis, Isoxazoles chemistry, Renin antagonists & inhibitors
- Abstract
The design and optimization of a novel isoxazole S(1) linker for renin inhibitor is described herein. This effort culminated in the identification of compound 18, an orally bioavailable, sub-nanomolar renin inhibitor even in the presence of human plasma. When compound 18 was found to inhibit CYP3A4 in a time dependent manner, two strategies were pursued that successfully delivered equipotent compounds with minimal TDI potential., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
5. 3,4-Diarylpiperidines as potent renin inhibitors.
- Author
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Lacombe P, Arbour M, Aspiotis R, Cauchon E, Chen A, Dubé D, Falgueyret JP, Fournier PA, Gallant M, Grimm E, Han Y, Juteau H, Liu S, Mellon C, Ramtohul Y, Simard D, St-Jacques R, and Tsui GC
- Subjects
- Animals, Antihypertensive Agents pharmacokinetics, Antihypertensive Agents pharmacology, Biological Availability, Cytochrome P-450 CYP3A metabolism, Cytochrome P-450 CYP3A Inhibitors, Dogs, Ether-A-Go-Go Potassium Channels metabolism, Humans, Piperidines pharmacokinetics, Piperidines pharmacology, Rats, Rats, Sprague-Dawley, Rats, Transgenic, Renin metabolism, Structure-Activity Relationship, Antihypertensive Agents chemistry, Antihypertensive Agents therapeutic use, Hypertension drug therapy, Piperidines chemistry, Piperidines therapeutic use, Renin antagonists & inhibitors
- Abstract
The discovery and SAR of a series of potent renin inhibitors possessing a novel 3,4-diarylpiperidine scaffold are described herein. The resulting compound 38 exhibit low nanomolar plasma renin IC(50), had a clean CYP 3A4 profile and displayed micromolar affinity for the hERG channel. Furthermore, it was found to be efficacious in the double transgenic rat hypertension model and show good to moderate oral bioavailability in two animal species., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
6. Renin inhibitors for the treatment of hypertension: design and optimization of a novel series of spirocyclic piperidines.
- Author
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Chen A, Aspiotis R, Campeau LC, Cauchon E, Chefson A, Ducharme Y, Falgueyret JP, Gagné S, Han Y, Houle R, Laliberté S, Larouche G, Lévesque JF, McKay D, and Percival D
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- Animals, Antihypertensive Agents pharmacokinetics, Antihypertensive Agents therapeutic use, Binding Sites, Catalytic Domain, Computer Simulation, Cytochrome P-450 CYP3A metabolism, Cytochrome P-450 CYP3A Inhibitors, Dogs, Drug Design, Humans, Hypertension drug therapy, Macaca mulatta, Piperidines pharmacokinetics, Piperidines therapeutic use, Protease Inhibitors pharmacokinetics, Protease Inhibitors therapeutic use, Rats, Renin metabolism, Structure-Activity Relationship, Antihypertensive Agents chemistry, Piperidines chemistry, Protease Inhibitors chemistry, Renin antagonists & inhibitors, Spiro Compounds chemistry
- Abstract
The discovery and SAR of a novel series of spirocyclic renin inhibitors are described herein. It was found that by restricting the northern aromatic plate to the bioactive conformation through spirocyclization, increase in renin potency and decrease in hERG affinity could both be realized. When early members of this series were found to be potent time-dependent CYP3A4 inhibitors, two distinct strategies to address this liability were explored and this effort culminated in the identification of compound 31 as an optimized renin inhibitor., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
7. Impact of primer-induced conformational dynamics of HIV-1 reverse transcriptase on polymerase translocation and inhibition.
- Author
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Auger A, Beilhartz GL, Zhu S, Cauchon E, Falgueyret JP, Grobler JA, Ehteshami M, Götte M, and Melnyk RA
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- Allosteric Site, Catalysis, DNA Primers metabolism, DNA, Viral biosynthesis, HIV Reverse Transcriptase metabolism, Indoles metabolism, Nitriles metabolism, Pyridones metabolism, RNA, Viral biosynthesis, Reverse Transcription physiology, DNA Primers chemistry, DNA, Viral chemistry, HIV Reverse Transcriptase antagonists & inhibitors, HIV Reverse Transcriptase chemistry, HIV-1 enzymology, Indoles chemistry, Nitriles chemistry, Pyridones chemistry, RNA, Viral chemistry
- Abstract
The rapid emergence and the prevalence of resistance mutations in HIV-1 reverse transcriptase (RT) underscore the need to identify RT inhibitors with novel binding modes and mechanisms of inhibition. Recently, two structurally distinct inhibitors, phosphonoformic acid (foscarnet) and INDOPY-1 were shown to disrupt the translocational equilibrium of RT during polymerization through trapping of the enzyme in the pre- and the post-translocation states, respectively. Here, we show that foscarnet and INDOPY-1 additionally display a shared novel inhibitory preference with respect to substrate primer identity. In RT-catalyzed reactions using RNA-primed substrates, translocation inhibitors were markedly less potent at blocking DNA polymerization than in equivalent DNA-primed assays; i.e. the inverse pattern observed with marketed non-nucleoside inhibitors that bind the allosteric pocket of RT. This potency profile was shown to correspond with reduced binding on RNA·DNA primer/template substrates versus DNA·DNA substrates. Furthermore, using site-specific footprinting with chimeric RNA·DNA primers, we demonstrate that the negative impact of the RNA primer on translocation inhibitor potency is overcome after 18 deoxyribonucleotide incorporations, where RT transitions primarily into polymerization-competent binding mode. In addition to providing a simple means to identify similarly acting translocation inhibitors, these findings suggest a broader role for the primer-influenced binding mode on RT translocation equilibrium and inhibitor sensitivity.
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- 2011
- Full Text
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8. Renin inhibitors for the treatment of hypertension: design and optimization of a novel series of tertiary alcohol-bearing piperidines.
- Author
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Chen A, Cauchon E, Chefson A, Dolman S, Ducharme Y, Dubé D, Falgueyret JP, Fournier PA, Gagné S, Gallant M, Grimm E, Han Y, Houle R, Huang JQ, Hughes G, Jûteau H, Lacombe P, Lauzon S, Lévesque JF, Liu S, Macdonald D, Mackay B, McKay D, Percival MD, St-Jacques R, and Toulmond S
- Subjects
- Alcohols chemistry, Alcohols therapeutic use, Animals, Antihypertensive Agents chemistry, Molecular Structure, Piperidines chemistry, Piperidines therapeutic use, Rats, Renin chemistry, Structure-Activity Relationship, Alcohols chemical synthesis, Antihypertensive Agents chemical synthesis, Antihypertensive Agents therapeutic use, Drug Design, Hypertension drug therapy, Piperidines chemical synthesis, Renin antagonists & inhibitors
- Abstract
The design and optimization of a novel series of renin inhibitor is described herein. Strategically, by committing the necessary resources to the development of synthetic sequences and scaffolds that were most amenable for late stage structural diversification, even as the focus of the SAR campaign moved from one end of the molecule to another, highly potent renin inhibitors could be rapidly identified and profiled., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
9. Renin inhibitors for the treatment of hypertension: design and optimization of a novel series of pyridone-substituted piperidines.
- Author
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Chen A, Campeau LC, Cauchon E, Chefson A, Ducharme Y, Dubé D, Falgueyret JP, Fournier PA, Gagné S, Grimm E, Han Y, Houle R, Huang JQ, Lacombe P, Laliberté S, Lévesque JF, Liu S, MacDonald D, Mackay B, McKay D, Percival MD, Regan C, Regan H, St-Jacques R, and Toulmond S
- Subjects
- Animals, Dogs, Enzyme Inhibitors chemical synthesis, Enzyme Inhibitors chemistry, Enzyme Inhibitors pharmacology, Inhibitory Concentration 50, Models, Molecular, Molecular Structure, Piperidines chemistry, Piperidines therapeutic use, Pyridones chemistry, Pyridones therapeutic use, Rats, Structure-Activity Relationship, Drug Design, Hypertension drug therapy, Piperidines chemical synthesis, Pyridones chemical synthesis, Renin antagonists & inhibitors
- Abstract
An SAR campaign aimed at decreasing the overall lipophilicity of renin inhibitors such as 1 is described herein. It was found that replacement of the northern appendage in 1 with an N-methyl pyridone and subsequent re-optimization of the benzyl amide handle afforded compounds with in vitro and in vivo profiles suitable for further profiling. An unexpected CV toxicity in dogs observed with compound 20 led to the employment of a time and resource sparing rodent model for in vivo screening of key compounds. This culminated in the identification of compound 31 as an optimized renin inhibitor., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
10. A high-throughput continuous assay for screening and characterization of inhibitors of HIV reverse-transcriptase DNA polymerase activity.
- Author
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Cauchon E, Falgueyret JP, Auger A, and Melnyk RA
- Subjects
- Enzyme Activation drug effects, Fluorescence Resonance Energy Transfer, Kinetics, Reverse Transcriptase Inhibitors chemistry, DNA-Directed DNA Polymerase metabolism, Drug Discovery methods, HIV Reverse Transcriptase antagonists & inhibitors, HIV Reverse Transcriptase metabolism, High-Throughput Screening Assays, Nucleic Acid Synthesis Inhibitors, Reverse Transcriptase Inhibitors pharmacology
- Abstract
The authors have devised a continuous fluorescence-based assay to measure HIV reverse transcriptase (RT) polymerase activity for both high-throughput screening (HTS) and mechanistic characterization of inhibitors. The designed substrate is composed of a recessed DNA primer annealed to a DNA template that is labeled at the 5'-terminus with a donor fluorophore (AlexaFluor 488). RT-catalyzed incorporation of an acceptor-labeled deoxyuridine (dUTP-AlexaFluor 555) at the 3'-terminus of the fully extended DNA primer juxtaposes donor and acceptor fluorophores, resulting in robust fluorescence resonance energy transfer that can be monitored kinetically in real time. The assay is sensitive, permitting the use of low enzyme concentrations (<0.5 nM), and can be miniaturized for use in 384-well HTS mode. The authors further show that this assay is capable of evaluating inhibitor mechanism of action by confirming the binding mechanism of a set of nonnucleoside RT inhibitors. Given the versatility and the lack of requirement for costly platforms or radioactivity, this assay may serve to accelerate and streamline the discovery and characterization process for future antiviral agents.
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- 2011
- Full Text
- View/download PDF
11. The discovery and synthesis of potent zwitterionic inhibitors of renin.
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Aspiotis R, Chen A, Cauchon E, Dubé D, Falgueyret JP, Gagné S, Gallant M, Grimm EL, Houle R, Juteau H, Lacombe P, Laliberté S, Lévesque JF, MacDonald D, McKay D, Percival MD, Roy P, Soisson SM, and Wu T
- Subjects
- Administration, Oral, Animals, Catalytic Domain, Computer Simulation, Dogs, Drug Evaluation, Preclinical, Humans, Piperidines chemical synthesis, Piperidines chemistry, Piperidines pharmacokinetics, Protease Inhibitors chemistry, Protease Inhibitors pharmacokinetics, Rats, Rats, Sprague-Dawley, Renin metabolism, Structure-Activity Relationship, Protease Inhibitors chemical synthesis, Renin antagonists & inhibitors
- Abstract
The incorporation of a carboxylic acid within in a series of 3-amido-4-aryl substituted piperidines (represented by general structure 32) led to the discovery of potent, zwitterionic, renin inhibitors with improved off-target profiles (CYP3A4 time-dependent inhibition and hERG affinity) relative to analogous non-zwitterionic inhibitors of the past (i.e., 3). Strategies to address the oral absorption of these zwitterions are also discussed within., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
12. Development of a homogeneous immunoassay for the detection of angiotensin I in plasma using AlphaLISA acceptor beads technology.
- Author
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Cauchon E, Liu S, Percival MD, Rowland SE, Xu D, Binkert C, Strickner P, and Falgueyret JP
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- Angiotensin I immunology, Animals, Antibodies immunology, Humans, Male, Mice, Rats, Rats, Sprague-Dawley, Renin metabolism, Angiotensin I blood, Immunoassay methods
- Abstract
Plasma renin activity (PRA) is a well-established biomarker for assessing the efficacy of various antihypertensive agents such as direct renin inhibitors, angiotensin receptor blockers, and angiotensin-converting enzyme inhibitors (ACEIs). PRA measurements are obtained through the detection and quantification of angiotensin I (Ang I) produced by the action of renin on its natural substrate angiotensinogen. The most accepted and reproducible method for PRA measurement uses an antibody capture Ang I methodology that employs specific antibodies that recognize and protect Ang I against angiotensinase activities contained in plasma. The amount of Ang I is then quantified by either radioimmunoassay (RIA) or enzyme immunoassay (EIA). In the current report, we describe the optimization of a novel homogeneous immunoassay based on the AlphaScreen technology for the detection and quantification of antibody-captured Ang I using AlphaLISA acceptor beads in buffer and in the plasma of various species (human, rat, and mouse). Ex vivo measurements of renin activity were performed using 10 microl or less of a reaction mixture, and concentrations as low as 1 nM Ang I were quantified. Titration curves obtained for the quantification of Ang I in buffer and plasma gave similar EC(50) values of 5.6 and 14.4 nM, respectively. Both matrices generated an equivalent dynamic range that varies from approximately 1 to 50 nM. Renin inhibitors have been successfully titrated and IC(50) values obtained correlated well with those obtained using EIA methodology (r(2)=0.80). This assay is sensitive, robust, fast, and less tedious than measurements performed using nonhomogeneous EIA. The AlphaLISA methodology is homogeneous, does not require wash steps prior to the addition of reagents, and does not generate radioactive waste.
- Published
- 2009
- Full Text
- View/download PDF
13. [Breathing school, my asthma and me].
- Author
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Laufer N, Cauchon E, and Laoudi Y
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- Adaptation, Psychological, Asthma psychology, Attitude to Health, Child, Child, Preschool, Humans, Nursing Education Research, Nursing Evaluation Research, Organizational Objectives, Paris, Program Evaluation, Psychology, Child, Self Care methods, Self Care psychology, Asthma prevention & control, Patient Education as Topic organization & administration, Pediatric Nursing organization & administration
- Published
- 2006
14. [Diagnosis and treatment of asthma in children].
- Author
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Laoudi Y, Laufer N, Cauchon E, Lefèvre F, Berthelot V, Just J, and Grimfeld A
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- Anti-Asthmatic Agents therapeutic use, Asthma epidemiology, Child, Child Welfare, France epidemiology, Humans, Patient Education as Topic, Pediatric Nursing organization & administration, Prevalence, Primary Prevention, Public Health, Respiratory Function Tests, Asthma diagnosis, Asthma therapy
- Published
- 2006
15. [When breathing school crosses frontiers].
- Author
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Laufer N, Cauchon E, and Boukabous L
- Subjects
- Algeria, Child, Humans, Paris, Romania, Spain, Asthma prevention & control, International Educational Exchange, Patient Education as Topic organization & administration, Pediatric Nursing organization & administration
- Published
- 2006
16. Identification of an indole series of prostaglandin D2 receptor antagonists.
- Author
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Sturino CF, Lachance N, Boyd M, Berthelette C, Labelle M, Li L, Roy B, Scheigetz J, Tsou N, Brideau C, Cauchon E, Carriere MC, Denis D, Greig G, Kargman S, Lamontagne S, Mathieu MC, Sawyer N, Slipetz D, O'Neill G, Wang Z, Zamboni R, Metters KM, and Young RN
- Subjects
- Indoles chemical synthesis, Molecular Structure, Receptors, Immunologic metabolism, Receptors, Prostaglandin metabolism, Safrole analogs & derivatives, Safrole chemistry, Structure-Activity Relationship, Indoles chemistry, Indoles pharmacology, Receptors, Immunologic antagonists & inhibitors, Receptors, Prostaglandin antagonists & inhibitors
- Abstract
A novel indole series of PGD2 receptor (DP receptor) antagonists is presented. Optimization of this series led to the identification of potent and selective DP receptor antagonists. In particular, antagonists 35 and 36 were identified with Ki values of 2.6 and 1.8 nM, respectively. These two antagonists are also potent in a DP functional assay where they inhibit the PGD2 induced cAMP production in platelet rich plasma with IC50 values of 7.9 and 8.6 nM, respectively. The structure-activity relationships of this indole series of DP receptor antagonists will also be discussed.
- Published
- 2006
- Full Text
- View/download PDF
17. An automated multistep high-throughput screening assay for the identification of lead inhibitors of the inducible enzyme mPGES-1.
- Author
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Massé F, Guiral S, Fortin LJ, Cauchon E, Ethier D, Guay J, and Brideau C
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- Animals, Automation, Cattle, Chemistry, Pharmaceutical methods, Drug Design, Drug Evaluation, Preclinical, Humans, Immunoenzyme Techniques, Prostaglandin-E Synthases, Serum Albumin metabolism, Time Factors, Drug Industry methods, Intramolecular Oxidoreductases antagonists & inhibitors
- Abstract
Prostaglandin E2 synthase (mPGES-1), the enzyme which catalyzes the synthesis of PGE2, is induced during the inflammatory response. For this reason, mPGES-1 could be a potential therapeutic target. A high-throughput screening assay was developed to identify potential inhibitors of mPGES-1. The assay consisted of a 30-s mPGES-1 enzymatic reaction followed by the detection of PGE2 by enzyme immunoassay (EIA). The enzymatic reaction was performed in a batch mode because the instability of the substrate (10 min) limited the number of plates assayed within a working day. The detection of the product by EIA was performed on 3 instruments requiring 14 different steps for complete automation. The authors describe here the optimization and implementation of a 2-part assay on a Thermo CRS robotic system. More than 315,000 compounds were tested, and a hit rate of 0.84% was obtained for this assay. Although the entire assay required multiple steps, the assay was successfully miniaturized and automated for a high-throughput screening campaign.
- Published
- 2005
- Full Text
- View/download PDF
18. Molecular pharmacology of the human prostaglandin D2 receptor, CRTH2.
- Author
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Sawyer N, Cauchon E, Chateauneuf A, Cruz RP, Nicholson DW, Metters KM, O'Neill GP, and Gervais FG
- Subjects
- Binding, Competitive drug effects, Binding, Competitive physiology, Cell Line, Gene Expression Regulation drug effects, Gene Expression Regulation physiology, HL-60 Cells, Humans, RNA, Messenger biosynthesis, RNA, Messenger metabolism, Receptors, Immunologic agonists, Receptors, Immunologic biosynthesis, Receptors, Prostaglandin agonists, Receptors, Prostaglandin biosynthesis, Receptors, Prostaglandin physiology, Recombinant Proteins metabolism, Recombinant Proteins pharmacology, Transfection, Receptors, Immunologic metabolism, Receptors, Prostaglandin metabolism
- Abstract
1. The recombinant human prostaglandin D(2) (PGD(2)) receptor, hCRTH2, has been expressed in HEK293(EBNA) and characterized with respect to radioligand binding and signal transduction properties. High and low affinity binding sites for PGD(2) were identified in the CRTH2 receptor population by saturation analysis with respective equilibrium dissociation constants (K(D)) of 2.5 and 109 nM. This revealed that the affinity of PGD(2) for CRTH2 is eight times less than its affinity for the DP receptor. 2. Equilibrium competition binding assays revealed that of the compounds tested, only PGD(2) and several related metabolites bound with high affinity to CRTH2 (K(i) values ranging from 2.4 to 34.0 nM) with the following rank order of potency: PGD(2)>13,14-dihydro-15-keto PGD(2)>15-deoxy-Delta(12,14)-PGJ(2)>PGJ(2)>Delta(12)-PGJ(2)>15(S)-15 methyl-PGD(2). This is in sharp contrast with the rank order of potency obtained at DP : PGD(2)>PGJ(2)>Delta(12)-PGJ(2)>15-deoxy-Delta(12,14)-PGJ(2) >>>13,14-dihydro-15-keto-PGD(2). 3. Functional studies demonstrated that PGD(2) activation of recombinant CRTH2 results in decrease of intracellular cAMP in a pertussis toxin-sensitive manner. Therefore, we showed that CRTH2 can functionally couple to the G-protein G(alphai/o). PGD(2) and related metabolites were tested and their rank order of potency followed the results of the membrane binding assay. 4. By Northern blot analysis, we showed that, besides haemopoietic cells, CRTH2 is expressed in many other tissues such as brain, heart, thymus, spleen and various tissues of the digestive system. In addition, in situ hybridization studies revealed that CRTH2 mRNA is expressed in human eosinophils. Finally, radioligand binding studies demonstrated that two eosinophilic cell lines, butyric acid-differentiated HL-60 and AML 14.3D10, also endogenously express CRTH2.
- Published
- 2002
- Full Text
- View/download PDF
19. [A breathing school for asthmatic children].
- Author
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Caron O, Cauchon E, and Laufer N
- Subjects
- Asthma etiology, Child, Humans, Patient Care Team, Referral and Consultation, Asthma nursing, Breathing Exercises, Parents education, Patient Education as Topic
- Published
- 2000
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