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Thompson B, Dilly-Penchala S, Amara A, Reynolds H, Khoo S, Else L. Application of novel plasma separation filter cards for quantification of nucleoside/nucleotide reverse transcriptase inhibitor di/triphosphates in dried blood spots using LC-MS. Bioanalysis 2023; 15:739-756. [PMID: 37293769 PMCID: PMC10463213 DOI: 10.4155/bio-2023-0057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 05/24/2023] [Indexed: 06/10/2023] Open
Abstract
Background: A rapid and sensitive LC-MS method has been developed and validated for the quantification of nucleoside di/triphosphates using a novel plasma separation card (HemaSep). Materials & methods: Cards were spotted with whole blood and stored at -80°C. Metabolites were extracted using 70:30 MeOH:20% formic acid, followed by weak anion exchange SPE and eluted using a Biobasic-AX column. Quantification was performed using a triple quadrupole mass spectrometer with a calibration range of 1.25-250 pmol/sample. Results: The recovery of metabolites was high (>93%). Precision and accuracy were acceptable and metabolites remained stable on the card after 29 days (stored at ambient temperature). Conclusion: HemaSep dried blood spots are a useful microsampling tool and offer an alternative to liquid plasma as they maintain stability over time.
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Affiliation(s)
- Beth Thompson
- Department of Pharmacology & Therapeutics, Institute of Integrative, Systems & Molecular Biology, University of Liverpool, L7 8TX, UK
- Bioanalytical Facility, University of Liverpool, William Henry Duncan Building, Liverpool, L7 8TX, UK
| | - Sujan Dilly-Penchala
- Department of Pharmacology & Therapeutics, Institute of Integrative, Systems & Molecular Biology, University of Liverpool, L7 8TX, UK
- Bioanalytical Facility, University of Liverpool, William Henry Duncan Building, Liverpool, L7 8TX, UK
| | - Alieu Amara
- Department of Pharmacology & Therapeutics, Institute of Integrative, Systems & Molecular Biology, University of Liverpool, L7 8TX, UK
- Bioanalytical Facility, University of Liverpool, William Henry Duncan Building, Liverpool, L7 8TX, UK
| | - Helen Reynolds
- Department of Pharmacology & Therapeutics, Institute of Integrative, Systems & Molecular Biology, University of Liverpool, L7 8TX, UK
- Royal Liverpool University Hospital, Liverpool, L7 8XP, UK
| | - Saye Khoo
- Department of Pharmacology & Therapeutics, Institute of Integrative, Systems & Molecular Biology, University of Liverpool, L7 8TX, UK
- Bioanalytical Facility, University of Liverpool, William Henry Duncan Building, Liverpool, L7 8TX, UK
- Royal Liverpool University Hospital, Liverpool, L7 8XP, UK
| | - Laura Else
- Department of Pharmacology & Therapeutics, Institute of Integrative, Systems & Molecular Biology, University of Liverpool, L7 8TX, UK
- Bioanalytical Facility, University of Liverpool, William Henry Duncan Building, Liverpool, L7 8TX, UK
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2
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To EE. Cell and Tissue Specific Metabolism of Nucleoside and Nucleotide Drugs: Case Studies and Implications for Precision Medicine. Drug Metab Dispos 2023; 51:360-368. [PMID: 36446610 DOI: 10.1124/dmd.122.000856] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 10/31/2022] [Accepted: 11/16/2022] [Indexed: 12/05/2022] Open
Abstract
Many clinically used antiviral drugs are nucleoside or nucleotide analog drugs, which have a unique mechanism of action that requires intracellular phosphorylation. This dependence on intracellular activation presents novel challenges for the discovery and development of nucleoside/nucleotide analog drugs. Contrary to many small molecule drug development programs that rely on plasma pharmacokinetics and systemic exposures, the precise mechanisms that result in efficacious intracellular nucleoside triphosphate concentrations must be understood in the process of nucleoside/nucleotide drug development. The importance is highlighted here, using the following as case studies: the herpes treatment acyclovir, the cytomegalovirus therapy ganciclovir, and human immunodeficiency virus (HIV) treatments based on tenofovir, which are also in use for HIV prophylaxis. For each drug, the specificity of metabolism that results in its activation in different cells or tissues is discussed, and the implications explored. Acyclovir's dependence on a viral enzyme for activation provides selective pressure for resistance mutations. Ganciclovir is also dependent on a viral enzyme for activation, and suicide gene therapy capitalizes on that for a novel oncology treatment. The tissue of most relevance for tenofovir activation depends on its use as treatment or as prophylaxis, and the pharmacogenomics and drug-drug interactions in those tissues must be considered. Finally, differential metabolism of different tenofovir prodrugs and its effects on toxicity risk are explored. Taken together, these examples highlight the importance of understanding tissue specific metabolism for optimal use of nucleoside/nucleotide drugs in the clinic. SIGNIFICANCE STATEMENT: Nucleoside and nucleotide analogue drugs are cornerstones in current antiviral therapy and prevention efforts that require intracellular phosphorylation for activity. Understanding their cell and tissue specific metabolism enables their rational, precision use for maximum efficacy.
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Affiliation(s)
- Elaine E To
- Gilead Sciences, Inc., Foster City, California, USA
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3
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Mally A, Jarzina S. Mapping Adverse Outcome Pathways for Kidney Injury as a Basis for the Development of Mechanism-Based Animal-Sparing Approaches to Assessment of Nephrotoxicity. FRONTIERS IN TOXICOLOGY 2022; 4:863643. [PMID: 35785263 PMCID: PMC9242087 DOI: 10.3389/ftox.2022.863643] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 03/11/2022] [Indexed: 02/04/2023] Open
Abstract
In line with recent OECD activities on the use of AOPs in developing Integrated Approaches to Testing and Assessment (IATAs), it is expected that systematic mapping of AOPs leading to systemic toxicity may provide a mechanistic framework for the development and implementation of mechanism-based in vitro endpoints. These may form part of an integrated testing strategy to reduce the need for repeated dose toxicity studies. Focusing on kidney and in particular the proximal tubule epithelium as a key target site of chemical-induced injury, the overall aim of this work is to contribute to building a network of AOPs leading to nephrotoxicity. Current mechanistic understanding of kidney injury initiated by 1) inhibition of mitochondrial DNA polymerase γ (mtDNA Polγ), 2) receptor mediated endocytosis and lysosomal overload, and 3) covalent protein binding, which all present fairly well established, common mechanisms by which certain chemicals or drugs may cause nephrotoxicity, is presented and systematically captured in a formal description of AOPs in line with the OECD AOP development programme and in accordance with the harmonized terminology provided by the Collaborative Adverse Outcome Pathway Wiki. The relative level of confidence in the established AOPs is assessed based on evolved Bradford-Hill weight of evidence considerations of biological plausibility, essentiality and empirical support (temporal and dose-response concordance).
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4
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Dey K, Ghosh M. Investigation of the Structure and Dynamics of Antiviral Drug Adefovir Dipivoxil by Site-Specific Spin-Lattice Relaxation Time Measurements and Chemical Shift Anisotropy Tensor Measurements. ACS OMEGA 2020; 5:29373-29381. [PMID: 33225168 PMCID: PMC7676337 DOI: 10.1021/acsomega.0c04205] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Accepted: 10/26/2020] [Indexed: 06/11/2023]
Abstract
Adefovir is regarded as a potential antiviral agent. However, it cannot be considered as a valuable drug candidate due to its high polarity that limits its permeability across the human intestinal mucosa. When the ribose phosphate group of adefovir is replaced by the isopolar phosphonomethyl ether functionality, it neutralizes the negative charge of the drug. This makes the drug lipid-soluble and potent to diffuse across the cell membrane. The prodrug adefovir dipivoxil is regarded as a potent antiviral drug against hepatitis B virus (HBV), human immunodeficiency virus (HIV), Rauscher murine leukemia virus (R-MuLV), murine cytomegalovirus (MCMV), herpes simplex virus (HSV), simian immunodeficiency virus (SIV), and feline immunodeficiency virus (FIV). The correlation between the structure and the dynamics of adefovir dipivoxil is determined by measuring the principal components of chemical shift anisotropy (CSA) tensor, site-specific spin-lattice relaxation time, and molecular correlation time at crystallographically different carbon nuclei sites. The CSA parameters, spin-lattice relaxation time, and molecular correlation time of phosphorous nucleus of the organophosphate group of adefovir dipivoxil molecule are also determined. The spin-lattice relaxation time of carbon nuclei varies from 1 to 107 s. The range of molecular correlation time also varies from 10-4 to 10-8 s. These remarkable diversities of motional dynamics of the molecules imply that there exist various motional degrees of freedom within this valuable drug and these motional degrees of freedom are independent of each other, which may be the reason for the biological activities exhibited by the drug. The correlation between structure and dynamics of such an important antiviral drug adefovir dipivoxil can be visualized by these types of extensive spectroscopic measurements, which will enlighten the path of inventing advanced medicine in the pharmaceutical industry, and it will also illuminate the understanding of the structure-activity relationships of antiviral drug.
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Affiliation(s)
- Krishna
Kishor Dey
- Department
of Physics, Dr. Harisingh Gour Central University, Sagar, 470003 MP, India
| | - Manasi Ghosh
- Physics
Section, MMV, Banaras Hindu University, Varanasi, 221005 UP, India
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5
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Akinci E, Cha M, Lin L, Yeo G, Hamilton MC, Donahue CJ, Bermudez-Cabrera HC, Zanetti LC, Chen M, Barkal SA, Khowpinitchai B, Chu N, Velimirovic M, Jodhani R, Fife JD, Sovrovic M, Cole PA, Davey RA, Cassa CA, Sherwood RI. Elucidation of remdesivir cytotoxicity pathways through genome-wide CRISPR-Cas9 screening and transcriptomics. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2020:2020.08.27.270819. [PMID: 32869031 PMCID: PMC7457617 DOI: 10.1101/2020.08.27.270819] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The adenosine analogue remdesivir has emerged as a front-line antiviral treatment for SARS-CoV-2, with preliminary evidence that it reduces the duration and severity of illness1.Prior clinical studies have identified adverse events1,2, and remdesivir has been shown to inhibit mitochondrial RNA polymerase in biochemical experiments7, yet little is known about the specific genetic pathways involved in cellular remdesivir metabolism and cytotoxicity. Through genome-wide CRISPR-Cas9 screening and RNA sequencing, we show that remdesivir treatment leads to a repression of mitochondrial respiratory activity, and we identify five genes whose loss significantly reduces remdesivir cytotoxicity. In particular, we show that loss of the mitochondrial nucleoside transporter SLC29A3 mitigates remdesivir toxicity without a commensurate decrease in SARS-CoV-2 antiviral potency and that the mitochondrial adenylate kinase AK2 is a remdesivir kinase required for remdesivir efficacy and toxicity. This work elucidates the cellular mechanisms of remdesivir metabolism and provides a candidate gene target to reduce remdesivir cytotoxicity.
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Affiliation(s)
- Ersin Akinci
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115
- Department of Agricultural Biotechnology, Faculty of Agriculture, Akdeniz University, Antalya, 07070, Turkey
| | - Minsun Cha
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115
| | - Lin Lin
- Hubrecht Institute, 3584 CT Utrecht, the Netherlands
| | - Grace Yeo
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Computational and Systems Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Marisa C Hamilton
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115
| | - Callie J Donahue
- Department of Microbiology, National Emerging Infectious Disease Laboratories, Boston University Medical Campus, Boston, MA 02118, USA
| | - Heysol C Bermudez-Cabrera
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115
| | - Larissa C Zanetti
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115
- Hospital Israelita Albert Einstein, São Paulo, SP 05652-900, Brazil
| | - Maggie Chen
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138
| | - Sammy A Barkal
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115
| | - Benyapa Khowpinitchai
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115
| | - Nam Chu
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115
| | - Minja Velimirovic
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115
- Centre Hospitalier Universitaire de Québec Research Center-Université Laval, Québec, Québec G1V 4G2, Canada
| | - Rikita Jodhani
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115
| | - James D Fife
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115
| | - Miha Sovrovic
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115
| | - Philip A Cole
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115
| | - Robert A Davey
- Department of Microbiology, National Emerging Infectious Disease Laboratories, Boston University Medical Campus, Boston, MA 02118, USA
| | - Christopher A Cassa
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115
| | - Richard I Sherwood
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115
- Hubrecht Institute, 3584 CT Utrecht, the Netherlands
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6
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Discovery of genetic variants of the kinases that activate tenofovir among individuals in the United States, Thailand, and South Africa: HPTN067. PLoS One 2018; 13:e0195764. [PMID: 29641561 PMCID: PMC5895070 DOI: 10.1371/journal.pone.0195764] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 03/28/2018] [Indexed: 01/12/2023] Open
Abstract
Tenofovir (TFV), a nucleotide reverse transcriptase inhibitor, requires two phosphorylation steps to form a competitive inhibitor of HIV reverse transcriptase. Adenylate kinase 2 (AK2) has been previously demonstrated to phosphorylate tenofovir to tenofovir-monophosphate, while creatine kinase, muscle (CKM), pyruvate kinase, muscle (PKM) and pyruvate kinase, liver and red blood cell (PKLR) each have been found to phosphorylate tenofovir-monophosphate to the pharmacologically active tenofovir-diphosphate. In the present study, genomic DNA isolated from dried blood spots collected from 505 participants from Bangkok, Thailand; Cape Town, South Africa; and New York City, USA were examined for variants in AK2, CKM, PKM, and PKLR using next-generation sequencing. The bioinformatics tools SIFT and PolyPhen predicted that 19 of the 505 individuals (3.7% frequency) carried variants in at least one kinase that would result in a decrease or loss of enzymatic activity. To functionally test these predictions, AK2 and AK2 variants were expressed in and purified from E. coli, followed by investigation of their activities towards tenofovir. Interestingly, we found that purified AK2 had the ability to phosphorylate tenofovir-monophosphate to tenofovir-diphosphate in addition to phosphorylating tenofovir to tenofovir-monophosphate. Further, four of the six AK2 variants predicted to result in a loss or decrease of enzyme function exhibited a ≥30% decrease in activity towards tenofovir in our in vitro assays. Of note, an AK2 K28R variant resulted in a 72% and 81% decrease in the formation of tenofovir-monophosphate and tenofovir-diphosphate, respectively. These data suggest that there are naturally occurring genetic variants that could potentially impact TFV activation.
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7
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Viability of primary osteoblasts after treatment with tenofovir alafenamide: Lack of cytotoxicity at clinically relevant drug concentrations. PLoS One 2017; 12:e0169948. [PMID: 28182625 PMCID: PMC5300148 DOI: 10.1371/journal.pone.0169948] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 12/24/2016] [Indexed: 01/05/2023] Open
Abstract
Tenofovir alafenamide (TAF) is a phosphonoamidate prodrug of the nucleotide HIV reverse transcriptase inhibitor tenofovir (TFV). TAF is approved for the treatment of HIV-1 infection as part of the single-tablet regimen containing elvitegravir, cobicistat, emtricitabine, and TAF. When dosed once-daily, TAF results in approximately 90% lower levels of plasma TFV and a 4-fold increase in intracellular TFV-diphosphate (TFV-DP) in PBMCs compared with the TFV prodrug tenofovir disoproxil fumarate (TDF). Several antiretrovirals, including TDF, have been associated with bone mineral density decreases in patients; the effect of clinically relevant TAF concentrations on primary osteoblast viability was therefore assessed in vitro. Studies in PBMCs determined that a 2-hour TAF exposure at concentrations similar to human plasma Cmax achieved intracellular TFV-DP levels comparable to those observed after the maximum recommended human dose of 25 mg TAF. Comparable intracellular TFV-DP levels were achieved in primary osteoblasts with 2-hour TAF exposure daily for 3 days at concentrations similar to those used for PBMCs (100-400 nM). No change in cell viability was observed in either primary osteoblasts or PBMCs. The mean TAF CC50 in primary osteoblasts after 3 days of daily 2-hour pulses was >500 μM, which is >1033 times higher than the TAF maximum recommended human dose plasma Cmax. In summary, primary osteoblasts were not preferentially loaded by TAF compared with PBMCs, with comparable TFV-DP levels achieved in both cell types. Furthermore, there was no impact on osteoblast cell viability at clinically relevant TAF concentrations.
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8
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Margot NA, Kitrinos KM, Fordyce M, McCallister S, Miller MD, Callebaut C. Rare emergence of drug resistance in HIV-1 treatment-naïve patients after 48 weeks of treatment with elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide. HIV CLINICAL TRIALS 2016; 17:78-87. [PMID: 26892863 DOI: 10.1080/15284336.2016.1142731] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Tenofovir alafenamide (TAF), a novel prodrug of the NtRTI tenofovir (TFV), delivers TFV-diphosphate (TFV-DP) to target cells more efficiently than the current prodrug, tenofovir disoproxil fumarate (TDF), with a 90% reduction in TFV plasma exposure. TAF, within the fixed dose combination of elvitegravir /cobicistat / emtricitabine (FTC)/TAF (E/C/F/TAF), has been evaluated in one Phase 2 and two Phase 3 randomized, double-blinded studies in HIV-infected treatment-naive patients, comparing E/C/F/TAF to E/C/F/TDF. In these studies, the TAF-containing group demonstrated non-inferior efficacy to the TDF-containing comparator group with 91.9% of E/C/F/TAF patients having <50 copies/mL of HIV-1 RNA at week 48. An integrated resistance analysis across these three studies was conducted, including HIV-1 genotypic analysis at screening, and genotypic/phenotypic analysis for patients with HIV-1 RNA>400 copies/mL at virologic failure. Pre-existing primary resistance-associated mutations (RAMs) were observed at screening among the 1903 randomized and treated patients: 7.5% had NRTI-RAMs, 18.2% had NNRTI-RAMs, and 3.4% had primary PI-RAMs. Pre-treatment RAMs did not influence treatment response at Week 48. In the E/C/F/TAF group, resistance development was rare; seven patients (0.7%, 7/978) developed NRTI-RAMs, five of whom (0.5%, 5/978) also developed primary INSTI-RAMs. In the E/C/F/TDF group, resistance development was also rare; seven patients (0.8%, 7/925) developed NRTI-RAMs, four of whom (0.4%, 4/925) also developed primary INSTI-RAMs. An additional analysis by deep sequencing in virologic failures revealed minimal differences compared to population sequencing. Overall, resistance development was rare in E/C/F/TAF-treated patients, and the pattern of emergent mutations was similar to E/C/F/TDF.
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Affiliation(s)
- Nicolas A Margot
- a Gilead Sciences Inc. , 333 Lakeside Drive, Foster City , CA , 94404 , USA
| | - Kathryn M Kitrinos
- a Gilead Sciences Inc. , 333 Lakeside Drive, Foster City , CA , 94404 , USA
| | - Marshall Fordyce
- a Gilead Sciences Inc. , 333 Lakeside Drive, Foster City , CA , 94404 , USA
| | - Scott McCallister
- a Gilead Sciences Inc. , 333 Lakeside Drive, Foster City , CA , 94404 , USA
| | - Michael D Miller
- a Gilead Sciences Inc. , 333 Lakeside Drive, Foster City , CA , 94404 , USA
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9
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Naesens L, Snoeck R, Andrei G, Balzarini J, Neyts J, De Clercq E. HPMPC (cidofovir), PMEA (adefovir) and Related Acyclic Nucleoside Phosphonate Analogues: A Review of their Pharmacology and Clinical Potential in the Treatment of Viral Infections. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/095632029700800101] [Citation(s) in RCA: 184] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The acyclic nucleoside phosphonate (ANP) analogues are broad-spectrum antiviral agents, with potent and selective antiviral activity in vitro and in vivo. The prototype compounds are: ( S)-1-(3-hydroxy-2-phosphonylmethoxypropyl)cytosine (HPMPC, cidofovir), which is active against a wide variety of DNA viruses; 9-(2-phosphonylmethoxyethyl)adenine (PMEA, adefovir), which is active against retro-, herpes- and hepadnaviruses, and ( R)-9-(2-phosphonylmethoxypropyl) adenine (PMPA), which is active against retro- and hepadnaviruses. The antiviral action of the ANP analogues is based on a specific interaction of the active diphosphorylated metabolite with the viral DNA polymerase. The long intracellular half-life of the active metabolite accounts for the optimal efficacy in infrequent dosing schedules. The potential of HPMPC as a broad-spectrum anti-DNA virus agent, as originally observed in vitro and in vivo, has been confirmed in clinical trials. HPMPC has recently been commercially released in the USA for the treatment of cytomegalovirus retinitis in AIDS patients. In addition, topical systemic HPMPC is being (or will be) explored for use against other herpesviruses (i.e. herpes simplex virus, Epstein-Barr virus, or varicella-zoster virus), by adenoviruses, or by human papilloma- or polyomaviruses. Intravenous HPMPC is associated with dose-dependent nephrotoxicity, that should be counteracted by prehydration and concomitant administration of probenecid, and by the application of an infrequent dosing schedule. The oral prodrug of PMEA, bis(pivaloyloxymethyl)-PMEA, is currently being evaluated in patients infected with human immunodeficiency virus (HIV) or hepatitis B virus. Finally, preclinical data on the efficacy of PMPA in animal retrovirus models point to its potential usefulness against HIV infections, when given either prophylactically or therapeutically in the treatment of established HIV infections.
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Affiliation(s)
- L Naesens
- Rega Institute for Medical Research, Katholieke Universiteit Leuven, B-3000 Leuven, Belgium
| | - R Snoeck
- Rega Institute for Medical Research, Katholieke Universiteit Leuven, B-3000 Leuven, Belgium
| | - G Andrei
- Rega Institute for Medical Research, Katholieke Universiteit Leuven, B-3000 Leuven, Belgium
| | - J Balzarini
- Rega Institute for Medical Research, Katholieke Universiteit Leuven, B-3000 Leuven, Belgium
| | - J Neyts
- Rega Institute for Medical Research, Katholieke Universiteit Leuven, B-3000 Leuven, Belgium
| | - E De Clercq
- Rega Institute for Medical Research, Katholieke Universiteit Leuven, B-3000 Leuven, Belgium
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10
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Cihlar T, Chen MS. Incorporation of Selected Nucleoside Phosphonates and Anti-Human Immunodeficiency Virus Nucleotide Analogues into DNA by Human DNA Polymerases α, β and γ. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/095632029700800302] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Incorporation of selected diphosphates of nucleoside phosphonates and triphosphates of currently approved anti-human immunodeficiency virus nucleoside analogues into DNA by human DNA polymerases α, β and γ was studied. All three polymerases were able to incorporate diphosphates of 9-(2-phosphonomethoxyethyl)adenine (PMEApp), 9-(2-phosphonomethoxyethyl)guanine (PMEGpp), ( R)-9-(2-phosphonomethoxypropyl)adenine (PMPApp), ( R)-9-(2-phosphononomethoxypropyl)-2,6-diaminopurine (PMPDAPpp) and ( 2R,5R)-9-[2,5-dihydro-5-(phosphonomethoxy)-2-furanyl]adenine (D4APpp) into primer/template DNA of defined sequence. After incorporation, these nucleoside phosphonates acted as terminators of primer extension. Kinetic constants of their incorporation were determined and compared with those for incorporation of ddATP, ddCTP, (-)-2′-deoxy-3′-thiacytidine triphosphate (3TC-TP), 2′,3′-didehydro-3′-deoxythymidine triphosphate (d4T-TP) and 3′-azido-3′-deoxythymidine triphosphate (AZT-TP). Relative efficiencies of incorporation (percentage of the incorporation efficiency for the corresponding natural deoxynucleoside triphosphate) by DNA polymerase a ranged from 0.05% for 3TC-TP to 51% for PMEGpp. DNA polymerase β catalysed the incorporation with relative efficiencies ranging from 0.014% for AZT-TP to 125% for ddCTP, and efficiencies of incorporation by DNA polymerase γ varied between 0.13% for 3TC-TP and 25% for ddCTP. Generally, the lowest incorporation efficiencies with all three polymerases were found for PMPApp (0.06–1.4%) and PMPDAPpp (0.075–2.2%).
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Affiliation(s)
- T Cihlar
- Gilead Sciences, 346 Lakeside Drive, Foster City, CA 94404, USA
| | - MS Chen
- Gilead Sciences, 346 Lakeside Drive, Foster City, CA 94404, USA
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11
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Callebaut C, Stepan G, Tian Y, Miller MD. In Vitro Virology Profile of Tenofovir Alafenamide, a Novel Oral Prodrug of Tenofovir with Improved Antiviral Activity Compared to That of Tenofovir Disoproxil Fumarate. Antimicrob Agents Chemother 2015; 59:5909-16. [PMID: 26149992 PMCID: PMC4576064 DOI: 10.1128/aac.01152-15] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 06/29/2015] [Indexed: 12/29/2022] Open
Abstract
Tenofovir alafenamide (TAF) is an investigational oral prodrug of the HIV-1 nucleotide reverse transcriptase inhibitor tenofovir (TFV). Tenofovir disoproxil fumarate (TDF) is another TFV prodrug, widely used for the treatment of HIV-1 infection. TAF is converted mostly intracellularly to TFV and, in comparison to TDF, achieves higher tenofovir diphosphate (TFV-DP) levels in peripheral blood mononuclear cells. As a result, TAF has demonstrated potent anti-HIV-1 activity at lower doses than TDF in monotherapy studies. Here, the in vitro virology profile of TAF was evaluated and compared to that of TDF. TAF displayed potent antiviral activity against all HIV-1 groups/subtypes, as well as HIV-2. TAF exhibited minimal changes in the drug concentration needed to inhibit 50% of viral spread (EC50) upon removal of the prodrug, similar to TDF, demonstrating intracellular antiviral persistence. While TAF and TDF exhibited comparable potencies in the absence of serum pretreatment, TAF maintained activity in the presence of human serum, whereas TDF activity was significantly reduced. This result demonstrates TAF's improved plasma stability over TDF, which is driven by the different metabolic pathways of the two prodrugs and is key to TAF's improved in vivo antiviral activity. The activity of TAF is specific for HIV, as TAF lacked activity against a large panel of human viruses, with the exception of herpes simplex virus 2, where weak TAF antiviral activity was observed, as previously observed with TFV. Finally, in vitro combination studies with antiretroviral drugs from different classes showed additive to synergistic interactions with TAF, consistent with ongoing clinical studies with TAF in fixed-dose combinations with multiple other antiretroviral drugs for the treatment of HIV.
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Affiliation(s)
| | - George Stepan
- High Throughput Biology, Gilead Sciences, Inc., Foster City, California, USA
| | - Yang Tian
- High Throughput Biology, Gilead Sciences, Inc., Foster City, California, USA
| | - Michael D Miller
- Clinical Virology, Gilead Sciences, Inc., Foster City, California, USA
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12
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Lade JM, To EE, Hendrix CW, Bumpus NN. Discovery of Genetic Variants of the Kinases That Activate Tenofovir in a Compartment-specific Manner. EBioMedicine 2015; 2:1145-52. [PMID: 26501112 PMCID: PMC4588390 DOI: 10.1016/j.ebiom.2015.07.008] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 07/01/2015] [Accepted: 07/02/2015] [Indexed: 11/19/2022] Open
Abstract
Tenofovir (TFV) is used in combination with other antiretroviral drugs for human immunodeficiency virus (HIV) treatment and prevention. TFV requires two phosphorylation steps to become pharmacologically active; however, the kinases that activate TFV in cells and tissues susceptible to HIV infection have yet to be identified. Peripheral blood mononuclear cells (PBMC), vaginal, and colorectal tissues were transfected with siRNA targeting nucleotide kinases, incubated with TFV, and TFV-monophosphate (TFV-MP) and TFV-diphosphate (TFV-DP) were measured using mass spectrometry–liquid chromatography. Adenylate kinase 2 (AK2) performed the first TFV phosphorylation step in PBMC, vaginal, and colorectal tissues. Interestingly, both pyruvate kinase isozymes, muscle (PKM) or liver and red blood cell (PKLR), were able to phosphorylate TFV-MP to TFV-DP in PBMC and vaginal tissue, while creatine kinase, muscle (CKM) catalyzed this conversion in colorectal tissue. In addition, next-generation sequencing of the Microbicide Trials Network MTN-001 clinical samples detected 71 previously unreported genetic variants in the genes encoding these kinases. In conclusion, our results demonstrate that TFV is activated in a compartment-specific manner. Further, genetic variants have been identified that could negatively impact TFV activation, thereby compromising TFV efficacy in HIV treatment and prevention. The anti-HIV drug tenofovir is activated in a tissue-specific manner. AK2 phosphorylates tenofovir to tenofovir-monophosphate in PBMC, vagina, and colon. PKM, PKLR phosphorylate tenofovir-monophosphate to diphosphate in PBMC and vagina. CKM phosphorylates tenofovir-monophosphate to diphosphate in colon. Because these enzymes are polymorphic and may be dysfunctional in some individuals, these findings suggest that tenofovir-based HIV PrEP may not be protective for all individuals.
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Key Words
- AK2, adenylate kinase 2
- CKM, creatine kinase, muscle
- GUK1, guanylate kinase 1
- HIV
- HIV pre-exposure prophylaxis
- HIV, human immunodeficiency virus
- MTN-001, Microbicide Trials Network Study MTN-001
- Microbicide Trials Network study MTN-001
- NME1, NME/NM23 nucleoside diphosphate kinase 1
- Nucleotide kinases
- PBMC, peripheral blood mononuclear cells
- PKLR, pyruvate kinase, liver and red blood cell
- PKM, pyruvate kinase, muscle
- PrEP, pre-exposure prophylaxis
- SNV, single-nucleotide variant
- TFV, tenofovir
- TFV-DP, tenofovir-diphosphate
- TFV-MP, tenofovir-monophosphate
- Targeted next-generation sequencing
- Tenofovir activation
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Affiliation(s)
- Julie M Lade
- Department of Pharmacology & Molecular Sciences, Johns Hopkins University School of Medicine, 725 North Wolfe Street, Biophysics 307, Baltimore, MD 21205, USA ; Department of Medicine (Division of Clinical Pharmacology), Johns Hopkins University School of Medicine, 725 North Wolfe Street, Biophysics 307, Baltimore, MD 21205, USA
| | - Elaine E To
- Department of Pharmacology & Molecular Sciences, Johns Hopkins University School of Medicine, 725 North Wolfe Street, Biophysics 307, Baltimore, MD 21205, USA ; Department of Medicine (Division of Clinical Pharmacology), Johns Hopkins University School of Medicine, 725 North Wolfe Street, Biophysics 307, Baltimore, MD 21205, USA
| | - Craig W Hendrix
- Department of Pharmacology & Molecular Sciences, Johns Hopkins University School of Medicine, 600 North Wolfe Street, Blalock 569, Baltimore, MD 21287, USA ; Department of Medicine (Division of Clinical Pharmacology), Johns Hopkins University School of Medicine, 600 North Wolfe Street, Blalock 569, Baltimore, MD 21287, USA
| | - Namandjé N Bumpus
- Department of Pharmacology & Molecular Sciences, Johns Hopkins University School of Medicine, 725 North Wolfe Street, Biophysics 307, Baltimore, MD 21205, USA ; Department of Medicine (Division of Clinical Pharmacology), Johns Hopkins University School of Medicine, 725 North Wolfe Street, Biophysics 307, Baltimore, MD 21205, USA
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13
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Crean D, Bellwon P, Aschauer L, Limonciel A, Moenks K, Hewitt P, Schmidt T, Herrgen K, Dekant W, Lukas A, Bois F, Wilmes A, Jennings P, Leonard MO. Development of an in vitro renal epithelial disease state model for xenobiotic toxicity testing. Toxicol In Vitro 2014; 30:128-37. [PMID: 25536518 DOI: 10.1016/j.tiv.2014.11.015] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 11/25/2014] [Accepted: 11/30/2014] [Indexed: 12/28/2022]
Abstract
There is a growing impetus to develop more accurate, predictive and relevant in vitro models of renal xenobiotic exposure. As part of the EU-FP7, Predict-IV project, a major aim was to develop models that recapitulate not only normal tissue physiology but also aspects of disease conditions that exist as predisposing risk factors for xenobiotic toxicity. Hypoxia, as a common micro-environmental alteration associated with pathophysiology in renal disease, was investigated for its effect on the toxicity profile of a panel of 14 nephrotoxins, using the human proximal tubular epithelial RPTECT/TERT1 cell line. Changes in ATP, glutathione and resazurin reduction, after 14 days of daily repeat exposure, revealed a number of compounds, including adefovir dipivoxil with enhanced toxicity in hypoxia. We observed intracellular accumulation of adefovir in hypoxia and suggest decreases in the efflux transport proteins MRP4, MRP5, NHERF1 and NHERF3 as a possible explanation. MRP5 and NHERF3 were also down-regulated upon treatment with the HIF-1 activator, dimethyloxalylglycine. Interestingly, adefovir dependent gene expression shifted from alterations in cell cycle gene expression to an inflammatory response in hypoxia. The ability to investigate aspects of disease states and their influence on renal toxin handling is a key advantage of in vitro systems developed here. They also allow for detailed investigations into mechanisms of compound toxicity of potential importance for compromised tissue exposure.
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Affiliation(s)
- Daniel Crean
- University College Dublin, School of Medicine and Medical Science, Dublin, Ireland
| | - Patricia Bellwon
- Institut fuer Toxikologie, Universitaet Wuerzburg, Versbacher Str. 9, 97078 Würzburg, Germany
| | - Lydia Aschauer
- Division of Physiology, Department of Physiology and Medical Physics, Innsbruck Medical University, Innsbruck 6020, Austria
| | - Alice Limonciel
- Division of Physiology, Department of Physiology and Medical Physics, Innsbruck Medical University, Innsbruck 6020, Austria
| | - Konrad Moenks
- Emergentec Biodevelopment GmbH, Vienna 1180, Austria
| | - Philip Hewitt
- Merck KGaA, Merck Serono, Nonclinical Safety, Darmstadt 64293, Germany
| | - Tobias Schmidt
- Institut fuer Toxikologie, Universitaet Wuerzburg, Versbacher Str. 9, 97078 Würzburg, Germany
| | - Karin Herrgen
- Institut fuer Toxikologie, Universitaet Wuerzburg, Versbacher Str. 9, 97078 Würzburg, Germany
| | - Wolfgang Dekant
- Institut fuer Toxikologie, Universitaet Wuerzburg, Versbacher Str. 9, 97078 Würzburg, Germany
| | - Arno Lukas
- Emergentec Biodevelopment GmbH, Vienna 1180, Austria
| | - Frederic Bois
- Université de Technologie de Compiègne, Compiègne Cedex 60205, France
| | - Anja Wilmes
- Division of Physiology, Department of Physiology and Medical Physics, Innsbruck Medical University, Innsbruck 6020, Austria
| | - Paul Jennings
- Division of Physiology, Department of Physiology and Medical Physics, Innsbruck Medical University, Innsbruck 6020, Austria
| | - Martin O Leonard
- Centre for Radiation, Chemical and Environmental Hazards, Public Health England, Chilton, Didcot OX11 0RQ, UK.
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14
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Gómez-Coca RB, Sigel A, Operschall BP, Holý A, Sigel H. Solution properties of metal ion complexes formed with the antiviral and cytostatic nucleotide analogue 9-[2-(phosphonomethoxy)ethyl]-2-amino-6-dimethylaminopurine (PME2A6DMAP). CAN J CHEM 2014. [DOI: 10.1139/cjc-2014-0041] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The acidity constants of protonated 9-[2-(phosphonomethoxy)ethyl]-2-amino-6-dimethylaminopurine (H3(PME2A6DMAP)+) are considered, and the stability constants of the M(H;PME2A6DMAP)+ and M(PME2A6DMAP) complexes (M2+ = Mg2+, Ca2+, Sr2+, Ba2+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+, or Cd2+) were measured by potentiometric pH titrations in aqueous solution (25 °C; I = 0.1 mol/L, NaNO3). In the M(H;PME2A6DMAP)+ species, H+ and M2+ (mainly outersphere) are at the phosphonate group; this is relevant for phosphoryl-diester bridges in nucleic acids because, in the present system, there is no indication for a M2+–purine binding. This contrasts, for example, with the complexes formed by 9-[2-(phosphonomethoxy)ethyl]adenine, M(H;PMEA)+, where M2+ is mainly situated at the adenine residue. Application of log [Formula: see text] vs. [Formula: see text] plots for simple phosph(on)ate ligands, R–PO32− (R being a residue that does not affect M2+ binding), proves that all M(PME2A6DMAP) complexes have larger stabilities than what would be expected for a M2+–phosphonate coordination. Comparisons with M(PME–R) complexes, where R is a noncoordinating residue of the (phosphonomethoxy)ethane chain, allow one to conclude that the increased stability is due to the formation of five-membered chelates involving the ether–oxygen of the –CH2–O–CH2–PO32− residue: the percentages of formation of these M(PME2A6DMAP)cl/O chelates, which occur in intramolecular equilibria, vary between 20% (Sr2+, Ba2+) and 50% (Zn2+, Cd2+), up to a maximum of 67% (Cu2+). Any M2+ interaction with N3 or N7 of the purine moiety, as in the parent M(PMEA) complexes, is suppressed by the (C2)NH2 and (C6)N(CH3)2 substituents. This observation, together with the previously determined stacking properties, offers an explanation why PME2A6DMAP2– has remarkable therapeutic effects.
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Affiliation(s)
- Raquel B. Gómez-Coca
- Department of Chemistry, Inorganic Chemistry, University of Basel, Spitalstrasse 51, CH-4056 Basel, Switzerland
- Department of Food Characterization and Analysis, Instituto de la Grasa, Spanish National Research Council (CSIC), Avda. Padre García Tejero 4, E-41012 Seville, Spain
| | - Astrid Sigel
- Department of Chemistry, Inorganic Chemistry, University of Basel, Spitalstrasse 51, CH-4056 Basel, Switzerland
| | - Bert P. Operschall
- Department of Chemistry, Inorganic Chemistry, University of Basel, Spitalstrasse 51, CH-4056 Basel, Switzerland
| | - Antonín Holý
- Institute of Organic Chemistry and Biochemistry, Centre of Novel Antivirals and Antineoplastics, Academy of Sciences, CZ-16610 Prague, Czech Republic
| | - Helmut Sigel
- Department of Chemistry, Inorganic Chemistry, University of Basel, Spitalstrasse 51, CH-4056 Basel, Switzerland
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15
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Chen EQ, Shi Y, Wu DB, Tang H. Liquid oral suspension adefovir dipivoxil (GS-02-526): an update on treatments for hepatitis B infection. Expert Rev Anti Infect Ther 2014; 12:919-28. [PMID: 24927815 DOI: 10.1586/14787210.2014.928588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Though the global epidemiology of hepatitis B virus infection has declined due to effective immunization, chronic hepatitis B (CHB) remains a serious public health problem and there is still a need for more treatment options that are efficient, safe and simple for different kinds of CHB patients. Adefovir dipivoxil (ADV) liquid suspension (GS-02-526), as a new form of oral ADV, not only has competent antiviral efficacy, but is also more convenient for patients with swallowing difficulties or patients with impaired renal function requiring dosage adjustment. The clinical data evaluating the safety, tolerability and antiviral activity of liquid suspension of ADV as well as its tablet are summarized in this article. The availability of liquid oral suspension of ADV would allow more patients to receive timely and reasonable antiviral treatments.
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Affiliation(s)
- En-Qiang Chen
- Center of Infectious Diseases, West China Hospital of Sichuan University, No. 37 Guo Xue Xiang, Chengdu 610041, China
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16
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Comparison of the π-stacking properties of purine versus pyrimidine residues. Some generalizations regarding selectivity. J Biol Inorg Chem 2014; 19:691-703. [PMID: 24464134 DOI: 10.1007/s00775-013-1082-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Accepted: 12/18/2013] [Indexed: 10/25/2022]
Abstract
Aromatic-ring stacking is pronounced among the noncovalent interactions occurring in biosystems and therefore some pertinent features regarding nucleobase residues are summarized. Self-stacking decreases in the series adenine > guanine > hypoxanthine > cytosine ~ uracil. This contrasts with the stability of binary (phen)(N) adducts formed by 1,10-phenanthroline (phen) and a nucleobase residue (N), which is largely independent of the type of purine residue involved, including (N1)H-deprotonated guanine. Furthermore, the association constant for (phen)(A)(0/4-) is rather independent of the type and charge of the adenine derivative (A) considered, be it adenosine or one of its nucleotides, including adenosine 5'-triphosphate (ATP(4-)). The same holds for the corresponding adducts of 2,2'-bipyridine (bpy), although owing to the smaller size of the aromatic-ring system of bpy, the (bpy)(A)(0/4-) adducts are less stable; the same applies correspondingly to the adducts formed with pyrimidines. In accord herewith, [M(bpy)](adenosine)(2+) adducts (M(2+) is Co(2+), Ni(2+), or Cu(2+)) show the same stability as the (bpy)(A)(0/4-) ones. The formation of an ionic bridge between -NH3 (+) and -PO3 (2-), as provided by tryptophan [H(Trp)(±)] and adenosine 5'-monophosphate (AMP(2-)), facilitates recognition and stabilizes the indole-purine stack in [H(Trp)](AMP)(2-). Such indole-purine stacks also occur in nature. Similarly, the formation of a metal ion bridge as occurs, e.g., between Cu(2+) coordinated to phen and the phosphonate group of 9-[2-(phosphonomethoxy)ethyl]adenine (PMEA(2-)) dramatically favors the intramolecular stack in Cu(phen)(PMEA). The consequences of such interactions for biosystems are discussed, especially emphasizing that the energies involved in such isomeric equilibria are small, allowing Nature to shift such equilibria easily.
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17
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Effect of tenofovir on nucleotidases and cytokines in HIV-1 target cells. PLoS One 2013; 8:e78814. [PMID: 24205323 PMCID: PMC3808279 DOI: 10.1371/journal.pone.0078814] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Accepted: 09/17/2013] [Indexed: 01/01/2023] Open
Abstract
Tenofovir (TFV) has been widely used for pre-exposure prophylaxis of HIV-1 infection with mixed results. While the use of TFV in uninfected individuals for prevention of HIV-1 acquisition is actively being investigated, the possible consequences of TFV exposure for the HIV-target cells and the mucosal microenvironment are unknown. In the current study, we evaluated the effects of TFV treatment on blood-derived CD4⁺ T cells, monocyte-derived macrophages and dendritic cells (DC). Purified HIV-target cells were treated with different concentrations of TFV (0.001-1.0 mg/ml) for 2 to 24 hr. RNA was isolated and RT-PCR was performed to compare the levels of mRNA expression of nucleotidases and pro-inflammatory cytokine genes (MIP3α, IL-8 and TNFα) in the presence or absence of TFV. We found that TFV increases 5'-ecto-nucleotidase (NT5E) and inhibits mitochondrial nucleotidase (NT5M) gene expression and increases 5' nucleotidase activity in macrophages. We also observed that TFV stimulates the expression and secretion of IL-8 by macrophages, DC, and activated CD4⁺ T cells and increases the expression and secretion of MIP3α by macrophages. In contrast, TFV had no effect on TNFα secretion from macrophages, DC and CD4⁺ T cells. Our results demonstrate that TFV alters innate immune responses in HIV-target cells with potential implications for increased inflammation at mucosal surfaces. As new preventive trials are designed, these findings should provide a foundation for understanding the effects of TFV on HIV-target cells in microbicide trials.
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18
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Dang NT, Sivakumaran H, Harrich D, Coombes AG. An Evaluation of Polycaprolactone Matrices for Vaginal Delivery of the Antiviral, Tenofovir, in Preventing Heterosexual Transmission of HIV. J Pharm Sci 2013; 102:3725-35. [DOI: 10.1002/jps.23684] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Revised: 05/28/2013] [Accepted: 07/09/2013] [Indexed: 12/23/2022]
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19
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Roux L, Priet S, Payrot N, Weck C, Fournier M, Zoulim F, Balzarini J, Canard B, Alvarez K. Ester prodrugs of acyclic nucleoside thiophosphonates compared to phosphonates: synthesis, antiviral activity and decomposition study. Eur J Med Chem 2013; 63:869-81. [PMID: 23603046 DOI: 10.1016/j.ejmech.2013.02.039] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Revised: 01/30/2013] [Accepted: 02/26/2013] [Indexed: 12/25/2022]
Abstract
9-[2-(Thiophosphonomethoxy)ethyl]adenine [S-PMEA, 8] and (R)-9-[2-(Thiophosphonomethoxy)propyl]adenine [S-PMPA, 9] are acyclic nucleoside thiophosphonates we described recently that display the same antiviral spectrum (DNA viruses) as approved and potent phosphonates PMEA and (R)-PMPA. Here, we describe the synthesis, antiviral activities in infected cell cultures and decomposition study of bis(pivaloyloxymethoxy)-S-PMEA [Bis-POM-S-PMEA, 13] and bis(isopropyloxymethylcarbonyl)-S-PMPA [Bis-POC-S-PMPA, 14] as orally bioavailable prodrugs of the S-PMEA 8 and S-PMPA 9, in comparison to the equivalent "non-thio" derivatives [Bis-POM-PMEA, 11] and [Bis-POC-PMPA, 12]. Compounds 11, 12, 13 and 14 were evaluated for their in vitro antiviral activity against HIV-1-, HIV-2-, HBV- and a broad panel of DNA viruses, and found to exhibit moderate to potent antiviral activity. In order to determine the decomposition pathway of the prodrugs 11, 12, 13 and 14 into parent compounds PMEA, PMPA, 8 and 9, kinetic data and decomposition pathways in several media are presented. As expected, bis-POM-S-PMEA 13 and bis-POC-S-PMPA 14 behaved as prodrugs of S-PMEA 8 and S-PMPA 9. However, thiophosphonates 8 and 9 were released very smoothly in cell extracts, in contrast to the release of PMEA and PMPA from "non-thio" prodrugs 11 and 12.
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Affiliation(s)
- Loïc Roux
- Laboratoire d'Architecture et Fonction des Macromolécules Biologiques, UMR CNRS 7257, Equipe Chimie Médicinale et Virologie Structurale, Université Aix-Marseille, Parc scientifique de Luminy, 163 av. de Luminy, 13288 Marseille Cedex 9, France
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20
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Vibrational Spectroscopic Studies of Tenofovir Using Density Functional Theory Method. J CHEM-NY 2013. [DOI: 10.1155/2013/126502] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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21
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Gallier F, Alexandre JAC, El Amri C, Deville-Bonne D, Peyrottes S, Périgaud C. 5′,6′-Nucleoside Phosphonate Analogues Architecture: Synthesis and Comparative Evaluation towards Metabolic Enzymes. ChemMedChem 2011; 6:1094-106. [DOI: 10.1002/cmdc.201100068] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Revised: 04/04/2011] [Indexed: 01/27/2023]
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22
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Schildgen O. Host factors may influence response to antiviral therapy in chronic hepatitis B virus infections. Med Hypotheses 2011; 76:417-20. [DOI: 10.1016/j.mehy.2010.11.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Revised: 11/02/2010] [Accepted: 11/08/2010] [Indexed: 10/18/2022]
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23
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Anderson PL, Kiser JJ, Gardner EM, Rower JE, Meditz A, Grant RM. Pharmacological considerations for tenofovir and emtricitabine to prevent HIV infection. J Antimicrob Chemother 2011; 66:240-50. [PMID: 21118913 PMCID: PMC3019086 DOI: 10.1093/jac/dkq447] [Citation(s) in RCA: 139] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The use of antiretroviral medications in HIV-negative individuals as pre-exposure prophylaxis (PrEP) is a promising approach to prevent HIV infection. Tenofovir disoproxil fumarate (TDF) and emtricitabine exhibit desirable properties for PrEP including: favourable pharmacokinetics that support infrequent dosing; few major drug-drug or drug-food interactions; an excellent clinical safety record; and pre-clinical evidence for efficacy. Several large, randomized, controlled clinical trials are evaluating the safety and efficacy of TDF and emtricitabine for this new indication. A thorough understanding of variability in drug response will help determine future investigations in the field and/or implementation into clinical care. Because tenofovir and emtricitabine are nucleos(t)ide analogues, the HIV prevention and toxicity effects depend on the triphosphate analogue formed intracellularly. This review identifies important cellular pharmacology considerations for tenofovir and emtricitabine, which include drug penetration into relevant tissues and cell types, race/ethnicity/pharmacogenetics, gender, cellular activation state and appropriate episodic or alternative dosing strategies based on pharmacokinetic principles. The current state of knowledge in these areas is summarized and the future utility of intracellular pharmacokinetics/pharmacodynamics for the PrEP field is discussed.
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Affiliation(s)
- Peter L Anderson
- Department of Pharmaceutical Sciences, University of Colorado Denver, Aurora, CO, USA.
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24
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Topalis D, Pradère U, Roy V, Caillat C, Azzouzi A, Broggi J, Snoeck R, Andrei G, Lin J, Eriksson S, Alexandre JAC, El-Amri C, Deville-Bonne D, Meyer P, Balzarini J, Agrofoglio LA. Novel Antiviral C5-Substituted Pyrimidine Acyclic Nucleoside Phosphonates Selected as Human Thymidylate Kinase Substrates. J Med Chem 2010; 54:222-32. [DOI: 10.1021/jm1011462] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Dimitri Topalis
- Groupe d’Enzymologie Moléculaire et Fonctionnelle, UR4-UPMC, Université Pierre et Marie Curie, Sorbonne Universités, case courrier 256, 7, quai St Bernard, 75252 Paris Cedex 05, France
| | - Ugo Pradère
- Institut de Chimie Organique et Analytique, Centre National de Recherche Scientifique Unité Mixte de Recherche 6005, Université d’Orléans, 45067 Orléans, France
| | - Vincent Roy
- Institut de Chimie Organique et Analytique, Centre National de Recherche Scientifique Unité Mixte de Recherche 6005, Université d’Orléans, 45067 Orléans, France
| | - Christophe Caillat
- Laboratoire d’Enzymologie et Biochimie Structurales, Centre National de la Recherche Scientifique UPR 3082, 91198 Gif-sur-Yvette Cedex, France
| | - Ahmed Azzouzi
- Institut de Chimie Organique et Analytique, Centre National de Recherche Scientifique Unité Mixte de Recherche 6005, Université d’Orléans, 45067 Orléans, France
| | - Julie Broggi
- Institut de Chimie Organique et Analytique, Centre National de Recherche Scientifique Unité Mixte de Recherche 6005, Université d’Orléans, 45067 Orléans, France
| | - Robert Snoeck
- REGA Institute for Medical Research, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Graciela Andrei
- REGA Institute for Medical Research, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Jay Lin
- Department of Veterinary Medical Chemistry, Swedish University of Agricultural Sciences, Box 575, Biomedical Center, S-751 24 Uppsala, Sweden
| | - Staffan Eriksson
- Department of Veterinary Medical Chemistry, Swedish University of Agricultural Sciences, Box 575, Biomedical Center, S-751 24 Uppsala, Sweden
| | - Julie A. C. Alexandre
- Groupe d’Enzymologie Moléculaire et Fonctionnelle, UR4-UPMC, Université Pierre et Marie Curie, Sorbonne Universités, case courrier 256, 7, quai St Bernard, 75252 Paris Cedex 05, France
| | - Chahrazade El-Amri
- Groupe d’Enzymologie Moléculaire et Fonctionnelle, UR4-UPMC, Université Pierre et Marie Curie, Sorbonne Universités, case courrier 256, 7, quai St Bernard, 75252 Paris Cedex 05, France
| | - Dominique Deville-Bonne
- Groupe d’Enzymologie Moléculaire et Fonctionnelle, UR4-UPMC, Université Pierre et Marie Curie, Sorbonne Universités, case courrier 256, 7, quai St Bernard, 75252 Paris Cedex 05, France
| | - Philippe Meyer
- Laboratoire d’Enzymologie et Biochimie Structurales, Centre National de la Recherche Scientifique UPR 3082, 91198 Gif-sur-Yvette Cedex, France
| | - Jan Balzarini
- REGA Institute for Medical Research, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Luigi A. Agrofoglio
- Institut de Chimie Organique et Analytique, Centre National de Recherche Scientifique Unité Mixte de Recherche 6005, Université d’Orléans, 45067 Orléans, France
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25
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Deville-Bonne D, El Amri C, Meyer P, Chen Y, Agrofoglio LA, Janin J. Human and viral nucleoside/nucleotide kinases involved in antiviral drug activation: structural and catalytic properties. Antiviral Res 2010; 86:101-20. [PMID: 20417378 DOI: 10.1016/j.antiviral.2010.02.001] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2009] [Revised: 01/31/2010] [Accepted: 02/01/2010] [Indexed: 12/11/2022]
Abstract
Antiviral nucleoside and nucleotide analogs, essential for the treatment of viral infections in the absence of efficient vaccines, are prodrug forms of the active compounds that target the viral DNA polymerase or reverse transcriptase. The activation process requires several successive phosphorylation steps catalyzed by different kinases, which are present in the host cell or encoded by some of the viruses. These activation reactions often are rate-limiting steps and are thus open to improvement. We review here the structural and enzymatic properties of the enzymes that carry out the activation of analogs used in therapy against human immunodeficiency virus and against DNA viruses such as hepatitis B, herpes and poxviruses. Four major classes of drugs are considered: thymidine analogs, non-natural L-nucleosides, acyclic nucleoside analogs and acyclic nucleoside phosphonate analogs. Their efficiency as drugs depends both on the low specificity of the viral polymerase that allows their incorporation into DNA, but also on the ability of human/viral kinases to provide the activated triphosphate active forms at a high concentration at the right place. Two distinct modes of action are considered, depending on the origin of the kinase (human or viral). If the human kinases are house-keeping enzymes that belong to the metabolic salvage pathway, herpes and poxviruses encode for related enzymes. The structures, substrate specificities and catalytic properties of each of these kinases are discussed in relation to drug activation.
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Affiliation(s)
- Dominique Deville-Bonne
- Enzymologie Moléculaire et Fonctionnelle, UR4 Université Pierre et Marie Curie, 7 quai St Bernard, 75252 Paris Cedex 05, France.
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Importance of serum concentration of adefovir for Lamivudine-adefovir combination therapy in patients with lamivudine-resistant chronic hepatitis B. Antimicrob Agents Chemother 2010; 54:3205-11. [PMID: 20498322 DOI: 10.1128/aac.01372-09] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Lamivudine (LMV)-adefovir pivoxil (ADV) combination therapy suppresses the replication of LMV-resistant hepatitis B virus (HBV), although its efficacy in suppressing HBV varies among patients. This study analyzed the clinical, virological, and pharmaceutical factors that influence the effect of the combination therapy. Patients negative for hepatitis B virus e antigen (HBeAg) and with low HBV DNA titers immediately prior to the combination therapy effectively cleared serum HBV DNA (P=0.0348 and P=0.0310, respectively). The maximum concentration of ADV in serum (ADV Cmax) was higher in patients who showed HBV DNA clearance (P=0.0392), and the cumulative clearance rates of HBV DNA were significantly higher in patients with ADV Cmax equal to or greater than 24 ng/ml (P=0.0284). HBeAg negativity and lower HBV DNA at the start of the combination therapy and higher ADV Cmax were found to be independent factors for serum HBV DNA clearance. Serum creatinine increased significantly during the combination therapy, and the ADV Cmax was higher in patients with low creatinine clearance rates. In conclusion, higher serum concentrations of ADV are associated with a good response to therapy based on clearance of HBV DNA in serum. However, care should be taken to prevent worsening of renal function due to high ADV serum concentrations.
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Koch K, Chen Y, Feng JY, Borroto-Esoda K, Deville-Bonne D, Gallois-Montbrun S, Janin J, Moréra S. Nucleoside diphosphate kinase and the activation of antiviral phosphonate analogs of nucleotides: binding mode and phosphorylation of tenofovir derivatives. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2010; 28:776-92. [PMID: 20183617 DOI: 10.1080/15257770903155899] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Tenofovir is an acyclic phosphonate analog of deoxyadenylate used in AIDS and hepatitis B therapy. We find that tenofovir diphosphate, its active form, can be produced by human nucleoside diphosphate kinase (NDPK), but with low efficiency, and that creatine kinase is significantly more active. The 1.65 A x-ray structure of NDPK in complex with tenofovir mono- and diphosphate shows that the analogs bind at the same site as natural nucleotides, but in a different conformation, and make only a subset of the Van der Waals and polar interactions made by natural substrates, consistent with their comparatively low affinity for the enzyme.
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Affiliation(s)
- Kerstin Koch
- Yeast Structural Genomics, IBBMC UMR 8619 CNRS, Universite Paris-Sud, Orsay, France
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Abacavir and tenofovir disoproxil fumarate co-administration results in a nonadditive antiviral effect in HIV-1-infected patients. AIDS 2010; 24:707-16. [PMID: 20087154 DOI: 10.1097/qad.0b013e32833676eb] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
OBJECTIVES To evaluate a potential pharmacodynamic/pharmacokinetic interaction between abacavir (ABC) and tenofovir disoproxil fumarate (TDF). DESIGN AND METHODS This randomized trial compared 7 days of ABC or TDF monotherapy, separated by a 35-day washout, with 7 days of ABC + TDF dual-therapy in treatment-naive, HIV-1-infected patients. During each 7-day course, the slope of the phase I viral decay was estimated and steady-state intracellular concentrations of carbovir triphosphate (CBV-TP), deoxyguanosine triphosphate (dGTP), tenofovir diphosphate (TFV-DP) and deoxyadenosine triphosphate (dATP) were determined. RESULTS Twenty-one participants were randomized to initial monotherapy with ABC (n = 11) or TDF (n = 10). The addition of TDF did not increase the slope of viral decay compared to ABC alone (-0.15 log10 per day vs. -0.16 log10 per day, respectively). No decrease in CBV-TP or TFV-DP between monotherapy and dual-therapy was observed. However, intracellular dATP concentrations increased between monotherapy and dual-therapy [median dATP (fmol/10 cells) 3293 vs. 4638; P = 0.08], although this difference was significant only among patients randomized to TDF [median dATP (fmol/10 cells) 3238 vs. 4534; P = 0.047]. A lower TFV-DP-to-dATP ratio was associated with reduced viral decay during dual-therapy (rho = -0.529; P = 0.045). CONCLUSION In this study, the viral decay during ABC and TDF dual-therapy was similar to that during ABC therapy alone, suggesting a nonadditive antiviral effect. This negative pharmacodynamic interaction was not explained by changes in CBV-TP or TFV-DP concentrations. Rather, modest increases in endogenous dATP pools were associated with reduced antiviral potency of TDF during co-administration with ABC.
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Mehellou Y, Balzarini J, McGuigan C. Aryloxy phosphoramidate triesters: a technology for delivering monophosphorylated nucleosides and sugars into cells. ChemMedChem 2010; 4:1779-91. [PMID: 19760699 DOI: 10.1002/cmdc.200900289] [Citation(s) in RCA: 173] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Prodrug technologies aimed at delivering nucleoside monophosphates into cells (protides) have proved to be effective in improving the therapeutic potential of antiviral and anticancer nucleosides. In these cases, the nucleoside monophosphates are delivered into the cell, where they may then be further converted (phosphorylated) to their active species. Herein, we describe one of these technologies developed in our laboratories, known as the phosphoramidate protide method. In this approach, the charges of the phosphate group are fully masked to provide efficient passive cell-membrane penetration. Upon entering the cell, the masking groups are enzymatically cleaved to release the phosphorylated biomolecule. The application of this technology to various therapeutic nucleosides has resulted in improved antiviral and anticancer activities, and in some cases it has transformed inactive nucleosides to active ones. Additionally, the phosphoramidate technology has also been applied to numerous antiviral nucleoside phosphonates, and has resulted in at least three phosphoramidate-based nucleotides progressing to clinical investigations. Furthermore, the phosphoramidate technology has been recently applied to sugars (mainly glucosamine) in order to improve their therapeutic potential. The development of the phosphoramidate technology, mechanism of action and the application of the technology to various monophosphorylated nucleosides and sugars will be reviewed.
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Breton F, Delépée R, Agrofoglio LA. Molecular imprinting of AMP by an ionic-noncovalent dual approach. J Sep Sci 2009; 32:3285-91. [PMID: 19739141 DOI: 10.1002/jssc.200900226] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In order to mimic recognition properties of adenylate kinase, molecularly imprinted polymers (MIPs) were prepared for adenosine 5'-monophosphate (AMP), a substrate of the enzyme. Different functional monomers interacting with the phosphate moiety were tested, and the MIP giving the best specific binding of AMP was composed with one equivalent of 2-(dimethylamino)ethyl methacrylate and ten equivalents of acrylamide compared to AMP. Packed into solid phase cartridge, this polymer showed similar characteristics than the enzyme, since it was specific for AMP toward other nucleotides.
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Affiliation(s)
- Florent Breton
- Institut de Chimie Organique et Analytique, UMR 6005, Université d'Orléans, Orléans, France
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Lu P, Liu J, Wang Y, Chen X, Yang Y, Ji R. Design, synthesis and evaluation of novel oxazaphosphorine prodrugs of 9-(2-phosphonomethoxyethyl)adenine (PMEA, adefovir) as potent HBV inhibitors. Bioorg Med Chem Lett 2009; 19:6918-21. [PMID: 19889538 DOI: 10.1016/j.bmcl.2009.10.072] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2009] [Revised: 10/14/2009] [Accepted: 10/16/2009] [Indexed: 10/20/2022]
Abstract
A series of novel oxazaphosphorine prodrugs of 9-(2-phosphonomethoxyethyl)adenine (PMEA, adefovir) were synthesized and their anti-hepatitis B virus (HBV) activity was evaluated in HepG2 2.2.15 cells, with adefovir dipivoxil as a reference drug. In the cell assays, compounds 7b and 7d exhibited anti-HBV activity comparable to that of adefovir dipivoxil, while compound 7c, with an IC(50) value of 0.12 microM, was found to be three times more potent than the reference compound. In vitro stability studies showed that (S(P),S)-7c, the diastereomer of compound 7c, was stable in human blood plasma but underwent rapid metabolism to release the parent drug PMEA in liver microsomes. The possible metabolic pathway of (S(P),S)-7c in human liver microsomes was described. These findings suggest that compound (S(P),S)-7c is a promising anti-HBV drug candidate for further development.
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Affiliation(s)
- Peng Lu
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institute for Biological Sciences, Chinese Academy of Science, Shanghai 201203, China
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Karla PK, Quinn TL, Herndon BL, Thomas P, Pal D, Mitra A. Expression of multidrug resistance associated protein 5 (MRP5) on cornea and its role in drug efflux. J Ocul Pharmacol Ther 2009; 25:121-32. [PMID: 19323627 DOI: 10.1089/jop.2008.0084] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
PURPOSE The purpose of this manuscript is to investigate the presence of nucleoside/nucleotide efflux transporter in cornea and to evaluate the role in ocular drug efflux. METHODS RT-PCR, immunoprecipitation followed by Western blot analysis and immunostaining were employed to establish molecular presence of multidrug resistance associated protein 5 (MRP5) on cornea. Corneal efflux by MRP5 was studied with bis(POM)-PMEA and acyclovir using rabbit and human corneal epithelial cells along with MRP5 over expressing cells (MDCKII-MRP5). Ex vivo studies using excised rabbit cornea and in vivo ocular microdialysis in male New Zealand white rabbits were used to further evaluate the role of MRP5 in conferring ocular drug resistance. RESULTS RT-PCR confirms the expression of MRP5 in both rabbit and human corneal epithelial cells along with MDCKII-MRP5 cells. Immunoprecipitation followed by Western blot analysis using a rat (M511-54) monoclonal antibody that reacts with human epitope confirms the expression of MRP5 protein in human corneal epithelial cells and MDCKII-MRP5 cells. Immunostaining performed on human cornea indicates the localization of this efflux pump on both epithelium and endothelium. Efflux studies reveal that depletion of ATP decreased PMEA efflux significantly. MRP5 inhibitors also diminished PMEA and acyclovir efflux. However, depletion of glutathione did not alter efflux. MDR1 and MRP2 did not contribute to PMEA efflux. However, MRP2 is involved in acyclovir efflux while MDR1 do not participate in this process. TLC/autoradiography suggested the conversion of bis(POM)-PMEA to PMEA in rabbit and human corneal epithelial cells. Two well known antiglaucoma drugs, bimatoprost and latanoprost were rapidly effluxed by MRP5. Ex vivo study on intact rabbit corneas demonstrated accumulation of PMEA in cornea in the presence of ATP-depleting medium. In vivo ocular pharmacokinetics also revealed a significant increase in maximum aqueous humor concentration (C(max)) and area under the aqueous humor time curve (AUC) of acyclovir in the presence of MK-571, a specific MRP inhibitor. CONCLUSIONS Taken together immunolocalization on human cornea, in vitro efflux in human, rabbit corneal and MRP5 over expressing cells, ex vivo and in vivo studies in intact rabbit cornea suggest that MRP5 on cornea can significantly lower the permeability of antiviral and glaucoma drugs. These findings may be valuable in developing formulation strategies to optimize ocular bioavailability of topically administered ocular agents.
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Affiliation(s)
- Pradeep K Karla
- University of Missouri at Kansas City, Pharmaceutical Sciences, Kansas City, Missouri 64112, USA
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Fernández-Botello A, Holý A, Moreno V, Operschall BP, Sigel H. Intramolecular π–π stacking interactions in aqueous solution in mixed-ligand copper(II) complexes formed by heteroaromatic amines and the nucleotide analogue 9-[2-(phosphonomethoxy)ethyl]-2-aminopurine (PME2AP), an isomer of the antivirally active 9-[2-(phosphonomethoxy)ethyl]adenine (PMEA). Inorganica Chim Acta 2009. [DOI: 10.1016/j.ica.2008.02.035] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Topalis D, Alvarez K, Barral K, Munier-Lehmann H, Schneider B, Véron M, Guerreiro C, Mulard L, El-Amri C, Canard B, Deville-Bonne D. Acyclic phosphonate nucleotides and human adenylate kinases: impact of a borano group on alpha-P position. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2008; 27:319-31. [PMID: 18404568 DOI: 10.1080/15257770801941952] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Adenylate kinases are involved in the activation of antiviral drugs such as the acyclic phosphonates analogs PMEA and (R)PMPA. We examine the in vitro phosphorylation of PMEA and PMPA bearing a borano- or a H- group on the phosphorus atom. The alpha-borano or alpha-H on PMEA and PMPA were detrimental to the activity of recombinant human AMP kinases 1 and 2. Docking PMEA to the active site of AMP kinase 1 indicated that the borano group may prevent two conserved critical Arg interactions with the alpha-phosphate, resulting in substrate bad positioning.
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Affiliation(s)
- D Topalis
- Laboratoire d'Enzymologie, Université Paris, Paris, France
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35
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Abstract
Nucleoside analogues revolutionized the treatment of chronic HBV infection and have become the most important therapeutic option within the last decade. Currently, the nucleoside analogues lamivudine, telbivudine and entecavir, and the nucleotide analogue adefovir dipivoxil, are licensed. Tenofovir disoproxil fumarate (TDF) is another acyclic nucleotide analogue that has been successfully used in the treatment of HIV-infected patients, but has demonstrated significant antiviral activity in wild-type and lamivudine-resistant HBV infections. The use of TDF 300 mg/day leads to marked suppression of HBV replication below the detection limit in different patients groups with HBV mono- or HIV/HBV co-infection in most instances, and a remarkably high rate of hepatitis B e antigen loss and even hepatitis B surface antigen loss was found in small, uncontrolled studies. Belonging to the substance class of acyclic nucleotide analogues, TDF is not cross-resistant to nucleoside analogue resistance-associated mutations. In equal dosages, TDF has comparable antiviral potency as compared with its congender adefovir dipivoxil, but in clinical studies exhibits higher antiviral efficacy and generates a higher genetic barrier against the development of genotypic HBV resistance due to its approximately 24-fold higher dosage. Owing to the numerous newly developed compounds and as a consequence of the emerging problem of drug resistance, treatment concepts for chronic hepatitis B will certainly be modified in the future. Because of its quite favorable antiviral and safety properties, TDF will likely be highly regarded in the management of HBV infections in the future.
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Affiliation(s)
- Florian van Bömmel
- Medizinische Klinik m. S. Hepatologie und Gastroenterologie Charité, Campus Virchow-Klinikum Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Thomas Berg
- Medizinische Klinik mit Schwerpunkt Hepatologie und Gastroenterologie, Charité - Campus Virchow-Klinikum, Universitätsmedizin Berlin, Augustenburger Platz 1, D-13353 Berlin, Germany
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Birkus G, Kutty N, He GX, Mulato A, Lee W, McDermott M, Cihlar T. Activation of 9-[(R)-2-[[(S)-[[(S)-1-(Isopropoxycarbonyl)ethyl]amino] phenoxyphosphinyl]-methoxy]propyl]adenine (GS-7340) and other tenofovir phosphonoamidate prodrugs by human proteases. Mol Pharmacol 2008; 74:92-100. [PMID: 18430788 DOI: 10.1124/mol.108.045526] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
9-[(R)-2-[[(S)-[[(S)-1-(Isopropoxycarbonyl)ethyl]amino] phenoxyphosphinyl]-methoxy]propyl]adenine (GS-7340) is an isopropylalaninyl phenyl ester prodrug of the nucleotide HIV reverse transcriptase inhibitor tenofovir (TFV; 9-[(2-phosphonomethoxy)propyl]adenine) exhibiting potent anti-HIV activity and enhanced ability to deliver parent TFV into peripheral blood mononuclear cells (PBMCs) and other lymphatic tissues in vivo. The present study focuses on the intracellular metabolism of GS-7340 and its activation by a variety of cellular hydrolytic enzymes. Incubation of human PBMCs in the presence of GS-7340 indicates that the prodrug is hydrolyzed slightly faster to an intermediate TFV-alanine conjugate (TFV-Ala) in quiescent PBMCs compared with activated cells (0.21 versus 0.16 pmol/min/10(6) cells). In contrast, the conversion of TFV-Ala to TFV and subsequent phosphorylation to TFV-diphosphate occur more rapidly in activated PBMCs. The activity of GS-7340 hydrolase producing TFV-Ala in PBMCs is primarily localized in lysosomes and is sensitive to inhibitors of serine hydrolases. Cathepsin A, a lysosomal serine protease has recently been identified as the primary enzyme activating GS-7340 in human PBMCs. Results from the present study indicate that in addition to cathepsin A, a variety of serine and cysteine proteases cleave GS-7340 and other phosphonoamidate prodrugs of TFV. The substrate preferences displayed by these enzymes toward TFV amidate prodrugs are nearly identical to their preferences displayed against oligopeptide substrates, indicating that GS-7340 and other phosphonoamidate derivatives of TFV should be considered peptidomimetic prodrugs of TFV.
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Affiliation(s)
- Gabriel Birkus
- Gilead Sciences, Inc., 362 Lakeside Drive, Foster City, CA 94404, USA.
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Breton F, Delépée R, Jégourel D, Deville-Bonne D, Agrofoglio LA. Selective adenosine-5'-monophosphate uptake by water-compatible molecularly imprinted polymer. Anal Chim Acta 2008; 616:222-9. [PMID: 18482607 DOI: 10.1016/j.aca.2008.04.025] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2008] [Revised: 04/07/2008] [Accepted: 04/10/2008] [Indexed: 11/18/2022]
Abstract
Molecularly imprinted polymers (MIPs) were prepared for adenosine-5'-monophosphate (AMP), a substrate of AMP-activated protein kinase. The template molecule was formed by the vinylphenylboronate diester of adenosine on which 5'-free hydroxide was protected by tert-butyldimethylsilyl group in order to mimic the steric hindrance of the phosphate moiety of AMP. Molecular imprinting was performed by complexing acrylamide and the template in a highly cross-linked polymer. MIPs were tested in batch experiments with aqueous samples of nucleotides and a number of parameters were investigated. The use of tetrabutylammonium hydroxide (TBAH) was necessary to obtain a rebinding of nucleotides on MIP. The adsorption of AMP was optimal in 5 mM ammonium acetate buffer solution pH 9.5 for 30 min, with 30 mM of TBAH. The imprinted polymer was selective for AMP towards others nucleotides or deoxi analogues.
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Affiliation(s)
- Florent Breton
- Institut de Chimie Organique et Analytique, UMR CNRS 6005, Université d'Orléans, BP 6759 45067 Orléans, France
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Topalis D, Kumamoto H, Alexandre JAC, Dugué L, Pochet S, Berteina-Raboin S, Agrofoglio LA, Deville-Bonne D. Looking for new pyrimidine acyclic nucleotide analogues designed for phosphorylation by human UMP-CMP kinase. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2008; 26:1369-73. [PMID: 18066785 DOI: 10.1080/15257770701533982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Human UMP-CMP kinase is involved in the phosphorylation of nucleic acid precursors and also in the activation of antiviral analogues including cidofovir, an acyclic phosphonate compound that mimicks dCMP and shows a broad antiviral spectrum. The binding of ligands to the enzyme was here investigated using a fluorescent probe and a competitive titration assay. At the acceptor site, the enzyme was found to accommodate any base, purine and pyrimidine, including thymidine. A method for screening analogues based on their affinity for the UMP binding site was developed. The affinities of uracil vinylphosphonate derivatives modified in the 5 position were found similar to (d)UMP and (d)CMP and improved when compared to cidofovir.
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Affiliation(s)
- Dimitri Topalis
- Laboratoire d'Enzymologie Moléculaire et Fonctionnelle, CNRS-Université Paris 6, 4 place Jussieu, F-75005 Paris, France
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Intracellular metabolism of the nucleotide prodrug GS-9131, a potent anti-human immunodeficiency virus agent. Antimicrob Agents Chemother 2007; 52:648-54. [PMID: 18056281 DOI: 10.1128/aac.01209-07] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
GS-9131 is a phosphonoamidate prodrug of the novel ribose-modified phosphonate nucleotide analog GS-9148 that demonstrates potent anti-human immunodeficiency virus type 1 (HIV-1) activity and an excellent resistance profile in vitro. Prodrug moieties were optimized for the efficient delivery of GS-9148 and its active diphosphate (DP) metabolite to lymphoid cells following oral administration. To understand the intracellular pharmacology of GS-9131, incubations were performed with various types of lymphoid cells in vitro. The intracellular accumulation and antiviral activity levels of GS-9148 were limited by its lack of cellular permeation, and GS-9131 increased the delivery of GS-9148-DP by 76- to 290-fold relative to that of GS-9148. GS-9131 activation was saturable at high extracellular concentrations, potentially due to a high-affinity promoiety cleavage step. Once inside the cells, GS-9148 was efficiently phosphorylated, forming similar amounts of anabolites in primary lymphoid cells. The levels of GS-9148-DP formed in peripheral blood mononuclear cells infected with HIV-1 were similar to that in uninfected PBMCs, and approximately equivalent intracellular concentrations of GS-9148-DP and tenofovir (TVF)-DP were required to inhibit viral replication by 90%. Once it was formed, GS-9148-DP was efficiently retained in activated CD4(+) cells, with a half-life of 19 h. In addition, GS-9131 showed a low potential for drug interactions with other adenine nucleoside/nucleotide reverse transcriptase inhibitors, based on the lack of competition for anabolism between suprapharmacologic concentrations of GS-9148 and TVF and the lack of activity of GS-9131 metabolites against purine nucleoside phosphorylase, an enzyme involved in the clearance of 2',3'-dideoxyinosine. Together, these observations elucidate the cellular pharmacology of GS-9131 and illustrate its efficient loading of lymphoid cells, resulting in a prolonged intracellular exposure to the active metabolite GS-9148-DP.
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Abstract
The HIV/AIDS pandemic has existed for >25 years. Extensive work globally has provided avenues to combat viral infection, but the disease continues to rage on in the human population and infected approximately 4 million people in 2006 alone. In this review, we provide a brief history of HIV/AIDS, followed by analysis of one therapeutic target of HIV-1: its reverse transcriptase (RT). We discuss the biochemical characterization of RT in order to place emphasis on possible avenues of inhibition, which now includes both nucleoside and non-nucleoside modalities. Therapies against RT remain a cornerstone of anti-HIV treatment, but the virus eventually resists inhibition through the selection of drug-resistant RT mutations. Current inhibitors and associated resistance are discussed, with the hopes that new therapeutics can be developed against RT.
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Affiliation(s)
- Aravind Basavapathruni
- Yale University School of Medicine, Department of Pharmacology, New Haven, CT 06520-8066, USA
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Topalis D, Kumamoto H, Amaya Velasco MF, Dugué L, Haouz A, Alexandre JAC, Gallois-Montbrun S, Alzari PM, Pochet S, Agrofoglio LA, Deville-Bonne D. Nucleotide binding to human UMP-CMP kinase using fluorescent derivatives -- a screening based on affinity for the UMP-CMP binding site. FEBS J 2007; 274:3704-3714. [PMID: 17608725 DOI: 10.1111/j.1742-4658.2007.05902.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Methylanthraniloyl derivatives of ATP and CDP were used in vitro as fluorescent probes for the donor-binding and acceptor-binding sites of human UMP-CMP kinase, a nucleoside salvage pathway kinase. Like all NMP kinases, UMP-CMP kinase binds the phosphodonor, usually ATP, and the NMP at different binding sites. The reaction results from an in-line phosphotransfer from the donor to the acceptor. The probe for the donor site was displaced by the bisubstrate analogs of the Ap5X series (where X = U, dT, A, G), indicating the broad specificity of the acceptor site. Both CMP and dCMP were competitors for the acceptor site probe. To find antimetabolites for antivirus and anticancer therapies, we have developed a method of screening acyclic phosphonate analogs that is based on the affinity of the acceptor-binding site of the human UMP-CMP kinase. Several uracil vinylphosphonate derivatives had affinities for human UMP-CMP kinase similar to those of dUMP and dCMP and better than that of cidofovir, an acyclic nucleoside phosphonate with a broad spectrum of antiviral activities. The uracil derivatives were inhibitors rather than substrates of human UMP-CMP kinase. Also, the 5-halogen-substituted analogs inhibited the human TMP kinase less efficiently. The broad specificity of the enzyme acceptor-binding site is in agreement with a large substrate-binding pocket, as shown by the 2.1 A crystal structure.
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Affiliation(s)
- Dimitri Topalis
- Laboratoire d'Enzymologie Moléculaire et Fonctionnelle, FRE 2852 CNRS-Paris 6, Institut Jacques Monod, Paris, France Institut de Chimie Organique et Analytique, UMR CNRS 6005, FR 2708, Université d'Orléans, UFR Sciences, Orléans, France Unité de Biochimie Structurale, URA CNRS 2185, Institut Pasteur, Paris, France Unité de Chimie Organique, URA CNRS 2128, Institut Pasteur, Paris, France Plate-Forme 6- Cristallogénèse et Diffraction des Rayons X, Institut Pasteur, Paris, France Unité de Régulation Enzymatique des Activités Cellulaires, CNRS URA 2185, Institut Pasteur, Paris, France
| | - Hiroki Kumamoto
- Laboratoire d'Enzymologie Moléculaire et Fonctionnelle, FRE 2852 CNRS-Paris 6, Institut Jacques Monod, Paris, France Institut de Chimie Organique et Analytique, UMR CNRS 6005, FR 2708, Université d'Orléans, UFR Sciences, Orléans, France Unité de Biochimie Structurale, URA CNRS 2185, Institut Pasteur, Paris, France Unité de Chimie Organique, URA CNRS 2128, Institut Pasteur, Paris, France Plate-Forme 6- Cristallogénèse et Diffraction des Rayons X, Institut Pasteur, Paris, France Unité de Régulation Enzymatique des Activités Cellulaires, CNRS URA 2185, Institut Pasteur, Paris, France
| | - Maria-Fernanda Amaya Velasco
- Laboratoire d'Enzymologie Moléculaire et Fonctionnelle, FRE 2852 CNRS-Paris 6, Institut Jacques Monod, Paris, France Institut de Chimie Organique et Analytique, UMR CNRS 6005, FR 2708, Université d'Orléans, UFR Sciences, Orléans, France Unité de Biochimie Structurale, URA CNRS 2185, Institut Pasteur, Paris, France Unité de Chimie Organique, URA CNRS 2128, Institut Pasteur, Paris, France Plate-Forme 6- Cristallogénèse et Diffraction des Rayons X, Institut Pasteur, Paris, France Unité de Régulation Enzymatique des Activités Cellulaires, CNRS URA 2185, Institut Pasteur, Paris, France
| | - Laurence Dugué
- Laboratoire d'Enzymologie Moléculaire et Fonctionnelle, FRE 2852 CNRS-Paris 6, Institut Jacques Monod, Paris, France Institut de Chimie Organique et Analytique, UMR CNRS 6005, FR 2708, Université d'Orléans, UFR Sciences, Orléans, France Unité de Biochimie Structurale, URA CNRS 2185, Institut Pasteur, Paris, France Unité de Chimie Organique, URA CNRS 2128, Institut Pasteur, Paris, France Plate-Forme 6- Cristallogénèse et Diffraction des Rayons X, Institut Pasteur, Paris, France Unité de Régulation Enzymatique des Activités Cellulaires, CNRS URA 2185, Institut Pasteur, Paris, France
| | - Ahmed Haouz
- Laboratoire d'Enzymologie Moléculaire et Fonctionnelle, FRE 2852 CNRS-Paris 6, Institut Jacques Monod, Paris, France Institut de Chimie Organique et Analytique, UMR CNRS 6005, FR 2708, Université d'Orléans, UFR Sciences, Orléans, France Unité de Biochimie Structurale, URA CNRS 2185, Institut Pasteur, Paris, France Unité de Chimie Organique, URA CNRS 2128, Institut Pasteur, Paris, France Plate-Forme 6- Cristallogénèse et Diffraction des Rayons X, Institut Pasteur, Paris, France Unité de Régulation Enzymatique des Activités Cellulaires, CNRS URA 2185, Institut Pasteur, Paris, France
| | - Julie Anne C Alexandre
- Laboratoire d'Enzymologie Moléculaire et Fonctionnelle, FRE 2852 CNRS-Paris 6, Institut Jacques Monod, Paris, France Institut de Chimie Organique et Analytique, UMR CNRS 6005, FR 2708, Université d'Orléans, UFR Sciences, Orléans, France Unité de Biochimie Structurale, URA CNRS 2185, Institut Pasteur, Paris, France Unité de Chimie Organique, URA CNRS 2128, Institut Pasteur, Paris, France Plate-Forme 6- Cristallogénèse et Diffraction des Rayons X, Institut Pasteur, Paris, France Unité de Régulation Enzymatique des Activités Cellulaires, CNRS URA 2185, Institut Pasteur, Paris, France
| | - Sarah Gallois-Montbrun
- Laboratoire d'Enzymologie Moléculaire et Fonctionnelle, FRE 2852 CNRS-Paris 6, Institut Jacques Monod, Paris, France Institut de Chimie Organique et Analytique, UMR CNRS 6005, FR 2708, Université d'Orléans, UFR Sciences, Orléans, France Unité de Biochimie Structurale, URA CNRS 2185, Institut Pasteur, Paris, France Unité de Chimie Organique, URA CNRS 2128, Institut Pasteur, Paris, France Plate-Forme 6- Cristallogénèse et Diffraction des Rayons X, Institut Pasteur, Paris, France Unité de Régulation Enzymatique des Activités Cellulaires, CNRS URA 2185, Institut Pasteur, Paris, France
| | - Pedro Maria Alzari
- Laboratoire d'Enzymologie Moléculaire et Fonctionnelle, FRE 2852 CNRS-Paris 6, Institut Jacques Monod, Paris, France Institut de Chimie Organique et Analytique, UMR CNRS 6005, FR 2708, Université d'Orléans, UFR Sciences, Orléans, France Unité de Biochimie Structurale, URA CNRS 2185, Institut Pasteur, Paris, France Unité de Chimie Organique, URA CNRS 2128, Institut Pasteur, Paris, France Plate-Forme 6- Cristallogénèse et Diffraction des Rayons X, Institut Pasteur, Paris, France Unité de Régulation Enzymatique des Activités Cellulaires, CNRS URA 2185, Institut Pasteur, Paris, France
| | - Sylvie Pochet
- Laboratoire d'Enzymologie Moléculaire et Fonctionnelle, FRE 2852 CNRS-Paris 6, Institut Jacques Monod, Paris, France Institut de Chimie Organique et Analytique, UMR CNRS 6005, FR 2708, Université d'Orléans, UFR Sciences, Orléans, France Unité de Biochimie Structurale, URA CNRS 2185, Institut Pasteur, Paris, France Unité de Chimie Organique, URA CNRS 2128, Institut Pasteur, Paris, France Plate-Forme 6- Cristallogénèse et Diffraction des Rayons X, Institut Pasteur, Paris, France Unité de Régulation Enzymatique des Activités Cellulaires, CNRS URA 2185, Institut Pasteur, Paris, France
| | - Luigi André Agrofoglio
- Laboratoire d'Enzymologie Moléculaire et Fonctionnelle, FRE 2852 CNRS-Paris 6, Institut Jacques Monod, Paris, France Institut de Chimie Organique et Analytique, UMR CNRS 6005, FR 2708, Université d'Orléans, UFR Sciences, Orléans, France Unité de Biochimie Structurale, URA CNRS 2185, Institut Pasteur, Paris, France Unité de Chimie Organique, URA CNRS 2128, Institut Pasteur, Paris, France Plate-Forme 6- Cristallogénèse et Diffraction des Rayons X, Institut Pasteur, Paris, France Unité de Régulation Enzymatique des Activités Cellulaires, CNRS URA 2185, Institut Pasteur, Paris, France
| | - Dominique Deville-Bonne
- Laboratoire d'Enzymologie Moléculaire et Fonctionnelle, FRE 2852 CNRS-Paris 6, Institut Jacques Monod, Paris, France Institut de Chimie Organique et Analytique, UMR CNRS 6005, FR 2708, Université d'Orléans, UFR Sciences, Orléans, France Unité de Biochimie Structurale, URA CNRS 2185, Institut Pasteur, Paris, France Unité de Chimie Organique, URA CNRS 2128, Institut Pasteur, Paris, France Plate-Forme 6- Cristallogénèse et Diffraction des Rayons X, Institut Pasteur, Paris, France Unité de Régulation Enzymatique des Activités Cellulaires, CNRS URA 2185, Institut Pasteur, Paris, France
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Marchand B, White KL, Ly JK, Margot NA, Wang R, McDermott M, Miller MD, Götte M. Effects of the translocation status of human immunodeficiency virus type 1 reverse transcriptase on the efficiency of excision of tenofovir. Antimicrob Agents Chemother 2007; 51:2911-9. [PMID: 17517852 PMCID: PMC1932533 DOI: 10.1128/aac.00314-07] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The ATP-dependent phosphorolytic excision of nucleoside analogue reverse transcriptase inhibitors can diminish their inhibitory effects on human immunodeficiency virus replication. Previous studies have shown that excision can occur only when the reverse transcriptase complex exists in its pretranslocational state. Binding of the next complementary nucleotide causes the formation of a stable dead-end complex in the posttranslocational state, which blocks the excision reaction. To provide mechanistic insight into the excision of the acyclic phosphonate nucleotide analog tenofovir, we compared the efficiencies of the reaction in response to changes in the translocation status of the enzyme. We found that rates of excision of tenofovir with wild-type reverse transcriptase can be as high as those seen with 3'-azido-3'-deoxythymidine monophosphate (AZT-MP). Thymidine-associated mutations, which confer >100-fold and 3-fold decreased susceptibility to AZT and tenofovir, respectively, caused substantial increases in the efficiency of excision of both inhibitors. However, in contrast to the case for AZT-MP, the removal of tenofovir was highly sensitive to dead-end complex formation. Site-specific footprinting experiments revealed that complexes with AZT-terminated primers exist predominantly pretranslocation. In contrast, complexes with tenofovir-terminated primers are seen in both configurations. Low concentrations of the next nucleotide are sufficient to trap the complex posttranslocation despite the flexible, acyclic character of the compound. Thus, the relatively high rate of excision of tenofovir is partially neutralized by the facile switch to the posttranslocational state and by dead-end complex formation, which provides a degree of protection from excision in the cellular environment.
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Affiliation(s)
- Bruno Marchand
- Department of Microbiology & Immunology, McGill University, Lyman Duff Medical Building, Montreal, QC, Canada
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43
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Birkus G, Wang R, Liu X, Kutty N, MacArthur H, Cihlar T, Gibbs C, Swaminathan S, Lee W, McDermott M. Cathepsin A is the major hydrolase catalyzing the intracellular hydrolysis of the antiretroviral nucleotide phosphonoamidate prodrugs GS-7340 and GS-9131. Antimicrob Agents Chemother 2006; 51:543-50. [PMID: 17145787 PMCID: PMC1797775 DOI: 10.1128/aac.00968-06] [Citation(s) in RCA: 137] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
GS-7340 and GS-9131 {9-[(R)-2-[[(S)-[[(S)-1-(isopropoxycarbonyl)ethyl]amino]phenoxyphosphinyl]methoxy]-propyl]adenine and 9-(R)-4'-(R)-[[[(S)-1-[(ethoxycarbonyl)ethyl]amino]phenoxyphosphinyl]methoxy]-2'-fluoro-1'-furanyladenine, respectively} are novel alkylalaninyl phenyl ester prodrugs of tenofovir {9-R-[(2-phosphonomethoxy)propyl]adenine} (TFV) and a cyclic nucleotide analog, GS-9148 (phosphonomethoxy-2'-fluoro-2', 3'-dideoxydidehydroadenosine), respectively. Both prodrugs exhibit potent antiretroviral activity against both wild-type and drug-resistant human immunodeficiency virus type 1 strains and excellent in vivo pharmacokinetic properties. In this study, the main enzymatic activity responsible for the initial step in the intracellular activation of GS-7340 and GS-9131 was isolated from human peripheral blood mononuclear cells and identified as lysosomal carboxypeptidase A (cathepsin A [CatA]; EC 3.4.16.5). Biochemical properties of the purified hydrolase (native complex and catalytic subunit molecular masses of 100 and 29 kDa, respectively; isoelectric point [pI] of 5.5) matched those of CatA. Recombinant CatA and the isolated prodrug hydrolase displayed identical susceptibilities to inhibitors and identical substrate preferences towards a panel of tenofovir phosphonoamidate prodrugs. Incubation of both enzymes with 14C-labeled GS-7340 or [3H]difluorophosphonate resulted in the covalent labeling of identical 29-kDa catalytic subunits. Finally, following a 4-h incubation with GS-7340 and GS-9131, the intracellular concentrations of prodrug metabolites detected in CatA-negative fibroblasts were approximately 7.5- and 3-fold lower, respectively, than those detected in normal control fibroblasts. Collectively, these data demonstrate the key role of CatA in the intracellular activation of nucleotide phosphonoamidate prodrugs and open new possibilities for further improvement of this important class of antiviral prodrugs.
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Affiliation(s)
- Gabriel Birkus
- Gilead Sciences, Inc., 333 Lakeside Drive, Foster City, CA 94404, USA.
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44
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Imaoka T, Kusuhara H, Adachi M, Schuetz JD, Takeuchi K, Sugiyama Y. Functional involvement of multidrug resistance-associated protein 4 (MRP4/ABCC4) in the renal elimination of the antiviral drugs adefovir and tenofovir. Mol Pharmacol 2006; 71:619-27. [PMID: 17110501 DOI: 10.1124/mol.106.028233] [Citation(s) in RCA: 198] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Acyclic nucleotide phosphonates (adefovir, cidofovir, and tenofovir) are eliminated predominantly into the urine, and renal failure is their dose-limiting toxicity, particularly for adefovir and cidofovir. In this study, we examined the involvement of multidrug resistance-associated protein (MRP)4 (ABCC4) in their luminal efflux in the kidney. ATP-dependent uptake of adefovir and tenofovir but not cidofovir was observed only in the membrane vesicles expressing MRP4. The ATP-dependent uptake of adefovir and tenofovir by MRP4 was not saturated at 1 mM. The ATP-dependent uptake of adefovir by membrane vesicles expressing MRP4 was osmotic-sensitive. No ATP-dependent uptake of either agent was observed in the membrane vesicles expressing human MRP2 or breast cancer resistance protein. These nucleotide analogs were given to mice by constant intravenous infusion, and the plasma, urine, and tissue concentrations were determined. The kidney accumulation of adefovir and tenofovir was significantly greater in Mrp4 knockout mice (130 versus 66 and 191 versus 87 pmol/g tissue, respectively); thus, the renal luminal efflux clearance was estimated to be 37 and 46%, respectively, of the control. There was no difference in the fraction of mono- and diphosphorylated forms of adefovir in the kidney between wild-type and Mrp4 knockout mice. In mice, cidofovir was also eliminated via the urine by tubular secretion as well as glomerular filtration. There was no change in the kinetic parameters of cidofovir in Mrp4 knockout mice. Our results suggest that MRP4 is involved in the luminal efflux of both adefovir and tenofovir, but it makes only a limited contribution to the urinary excretion of cidofovir.
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Affiliation(s)
- Tomoki Imaoka
- Department of Molecular Pharmacokinetics, Graduate School of Pharmaceutical Sciences, the University of Tokyo, Japan, and Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN, USA
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Vela JE, Olson LY, Huang A, Fridland A, Ray AS. Simultaneous quantitation of the nucleotide analog adefovir, its phosphorylated anabolites and 2'-deoxyadenosine triphosphate by ion-pairing LC/MS/MS. J Chromatogr B Analyt Technol Biomed Life Sci 2006; 848:335-43. [PMID: 17101307 DOI: 10.1016/j.jchromb.2006.10.063] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2006] [Revised: 09/21/2006] [Accepted: 10/28/2006] [Indexed: 11/24/2022]
Abstract
The nucleotide analog adefovir is an important therapy for hepatitis B viral infection. The study of nucleoside/tide pharmacology has been hampered by difficulties encountered when trying to develop LC/MS/MS methods for these polar analytes. In an attempt to identify a more convenient, selective and sensitive alternative to the analysis of the metabolism of radiolabeled parent nucleotide traditionally used for in vitro cell culture studies, an LC/MS/MS method was developed for the quantitative detection of adefovir and its phosphorylated metabolites in cellular samples. Ion-pairing reversed phase LC using tetrabutylammonium (TBA) and ammonium phosphate had the best compromise between chromatographic separation and positive mode MS/MS detection. Using microbore reverse phase columns and a low flow acetonitrile gradient it was possible to quantitate adefovir, its metabolites and 2'-deoxyadenosine triphosphate. A cross-validation showed comparable levels of adefovir and its metabolites were determined using either LC/MS/MS or radioactivity detection. However, initial methods were conducted at high pH and utilized an acetonitrile step gradient causing unacceptable column life and unpredictable equilibration. Further method optimization lowered the concentration of TBA and phosphate, decreased pH and applied a linear gradient of acetonitrile. This work resulted in a method that was found to have sensitivity, accuracy and precision sufficient to be a useful tool in the study of the intracellular pharmacology of adefovir in vitro and may be more broadly applicable.
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46
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Lee WA, Martin JC. Perspectives on the development of acyclic nucleotide analogs as antiviral drugs. Antiviral Res 2006; 71:254-9. [PMID: 16837073 DOI: 10.1016/j.antiviral.2006.05.020] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2006] [Revised: 05/31/2006] [Accepted: 05/31/2006] [Indexed: 10/24/2022]
Abstract
The development of Viread (tenofovir disoproxil) for HIV and Hepsera (adefovir dipivoxil) for HBV presented many unique challenges. Unlike nucleosides and most conventional drugs, the parent acyclic nucleotide analogs are charged at physiologic pH and not suitable for oral administration which is highly desired in chronic therapies. Physicochemical properties, cellular permeation, renal toxicity, and bioavailability all had to be addressed during the development of these compounds. As a class, the acyclic nucleotides have long intracellular half-lives, allowing once-daily dosing, which provided the initial rationale for treatment of chronic viral diseases such as HIV and HBV. Prodrugs originally designed to deliver the parent acyclic nucleotide analog to the systemic circulation, also function to increase the tissue distribution and intracellular concentrations of the acyclic nucleotide diphosphate inside cells.
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Affiliation(s)
- William A Lee
- Gilead Sciences, Inc., 333 Lakeside Drive, Foster City, CA 94404, USA.
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van der Meulen K, Garré B, Croubels S, Nauwynck H. In vitro comparison of antiviral drugs against feline herpesvirus 1. BMC Vet Res 2006; 2:13. [PMID: 16640781 PMCID: PMC1475582 DOI: 10.1186/1746-6148-2-13] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2005] [Accepted: 04/26/2006] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Feline herpesvirus 1 (FHV-1) is a common cause of respiratory and ocular disease in cats. Especially in young kittens that have not yet reached the age of vaccination, but already lost maternal immunity, severe disease may occur. Therefore, there is a need for an effective antiviral treatment. In the present study, the efficacy of six antiviral drugs, i.e. acyclovir, ganciclovir, cidofovir, foscarnet, adefovir and 9-(2-phosphonylmethoxyethyl)-2, 6-diaminopurine (PMEDAP), against FHV-1 was compared in Crandell-Rees feline kidney (CRFK) cells using reduction in plaque number and plaque size as parameters. RESULTS The capacity to reduce the number of plaques was most pronounced for ganciclovir, PMEDAP and cidofovir. IC50 (NUMBER) values were 3.2 microg/ml (12.5 microM), 4.8 microg/ml (14.3 microM) and 6 microg/ml (21.5 microM), respectively. Adefovir and foscarnet were intermediately efficient with an IC50 (NUMBER) of 20 microg/ml (73.2 microM) and 27 microg/ml (140.6 microM), respectively. Acyclovir was least efficient (IC50 (NUMBER) of 56 microg/ml or 248.7 microM). All antiviral drugs were able to significantly reduce plaque size when compared with the untreated control. As observed for the reduction in plaque number, ganciclovir, PMEDAP and cidofovir were most potent in reducing plaque size. IC50 (SIZE) values were 0.4 microg/ml (1.7 microM), 0.9 microg/ml (2.7 microM) and 0.2 microg/ml (0.7 microM), respectively. Adefovir and foscarnet were intermediately potent, with an IC50 (SIZE) of 4 microg/ml (14.6 microM) and 7 microg/ml (36.4 microM), respectively. Acyclovir was least potent (IC50 (SIZE) of 15 microg/ml or 66.6 microM). The results demonstrate that the IC50 (SIZE) values were notably lower than the IC50 (NUMBER) values. The most remarkable effect was observed for cidofovir and ganciclovir. None of the products were toxic for CRFK cells at antiviral concentrations. CONCLUSION In conclusion, measuring reduction in plaque number and plaque size are two valuable and complementary means of assessing the efficacy of an antiviral drug. By using these parameters for six selected antiviral drugs, we found that ganciclovir, PMEDAP, and cidofovir are the most potent inhibitors of FHV-1 replication in CRFK cells. Therefore, they may be valuable candidates for the treatment of FHV-1 infection in cats.
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Affiliation(s)
| | - B Garré
- Laboratory of Virology
- Department of Pharmacology, Pharmacy and Toxicology, Faculty of Veterinary Medicine, Salisburylaan 133, Ghent University, 9820 Merelbeke, Belgium
| | - S Croubels
- Department of Pharmacology, Pharmacy and Toxicology, Faculty of Veterinary Medicine, Salisburylaan 133, Ghent University, 9820 Merelbeke, Belgium
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Mayer KH, Maslankowski LA, Gai F, El-Sadr WM, Justman J, Kwiecien A, Mâsse B, Eshleman SH, Hendrix C, Morrow K, Rooney JF, Soto-Torres L. Safety and tolerability of tenofovir vaginal gel in abstinent and sexually active HIV-infected and uninfected women. AIDS 2006; 20:543-51. [PMID: 16470118 DOI: 10.1097/01.aids.0000210608.70762.c3] [Citation(s) in RCA: 146] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To establish the highest practical dose and frequency (HPDF) of 0.3% or 1% tenofovir vaginal gel applied once or twice daily by sexually abstinent HIV-uninfected women, and to evaluate the safety, tolerability and systemic pharmacokinetics of the HPDF in abstinent and sexually active HIV-negative and HIV-infected women. METHODS Eighty-four women, enrolled in sequential cohorts, used the study product for 14 consecutive intermenstrual days. Safety laboratory assessments and pelvic examinations were carried out during five study visits, with colposcopy at enrollment and on day 14. Samples for pharmacokinetics were collected before and after the initial tenofovir gel use and at day 13. RESULTS The 1% tenofovir gel used twice daily was as well tolerated as other regimens used by the 48 HIV-negative sexually abstinent women, establishing the HPDF. Although 92% of the women reported at least one adverse event, the majority were mild (87%) and involved the genitourinary tract (70%). One possibly product-related severe adverse event involving lower abdominal cramping was reported by a sexually abstinent woman who used 0.3% gel twice daily. Serum tenofovir levels were low but detectable in 14 of the 25 women. No new HIV RNA resistance mutations were detected after 2 weeks of tenofovir gel in the 24 HIV-infected participants. No significant systemic toxicity was detected. CONCLUSION A 2-week course of 1% tenofovir vaginal gel used twice daily was well tolerated in sexually abstinent and sexually active HIV-negative and HIV-positive women. Systemic tenofovir absorption occurred. Expanded safety and effectiveness testing is warranted.
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Affiliation(s)
- Kenneth H Mayer
- Miriam Hospital/Brown University, Providence, Rhode Island 02906, USA.
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Fernández-Botello A, Griesser R, Holý A, Moreno V, Sigel H. Acid-base and metal-ion-binding properties of 9-[2-(2-phosphonoethoxy)ethyl]adenine (PEEA), a relative of the antiviral nucleotide analogue 9-[2-(phosphonomethoxy)ethyl]adenine (PMEA). An exercise on the quantification of isomeric complex equilibria in solution. Inorg Chem 2005; 44:5104-17. [PMID: 15998039 DOI: 10.1021/ic050341j] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The acidity constants of 3-fold protonated 9-[2-(2-phosphonoethoxy)ethyl]adenine, H3(PEEA)+, and of 2-fold protonated (2-phosphonoethoxy)ethane, H2(PEE), and the stability constants of the M(H;PEEA)+, M(PEEA), and M(PEE) complexes with M2+ = Mg2+, Ca2+, Sr2+, Ba2+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+, or Cd2+ have been determined (potentiometric pH titrations; aqueous solution; 25 degrees C; I = 0.1 M, NaNO3). It is concluded that in the M(H;PEEA)+ species, the proton is at the phosphonate group and the metal ion at the adenine residue. The application of previously determined straight-line plots of log K(M(R-PO3))M versus pK(H(R-PO3))H for simple phosph(on)ate ligands, R-PO3(2-), where R represents a residue that does not affect metal-ion binding, proves that the M(PEEA) complexes of Co2+, Ni2+, Cu2+, Zn2+, and Cd2+ as well as the M(PEE) complexes of Co2+, Cu2+, and Zn2+ have larger stabilities than is expected for a sole phosphonate coordination of M2+. For the M2+ complexes without an enhanced stability (e.g., Mg2+ or Mn2+), it is concluded that M2+ binds in a monodentate fashion to the phosphonate group of the two ligands. Combination of all of the results allows the following conclusions: (i) The increased stability of the Co(PEE), Cu(PEE), Zn(PEE), and Co(PEEA) complexes is due to the formation of six-membered chelates involving the ether-oxygen atom of the aliphatic residue (-CH2-O-CH2CH2-PO3(2-)) of the ligands with formation degrees of about 15-30%. (ii) Cd(PEEA) forms a macrochelate with N7 of the adenine residue (formation degree about 30%); Ni(PEEA) has similar properties. (iii) With Zn(PEEA), both mentioned types of chelates are observed, that is, Zn(PEEA)(cl/O) and Zn(PEEA)(cl/N7), with formation degrees of about 13 and 41%, respectively; the remaining 46% is due to the "open" isomer Zn(PEEA)(op) in which the metal ion binds only to the PO3(2-) group. (iv) Most remarkable is Cu(PEEA) because a fourth isomer, Cu(PEEA)(cl/O/N3), is formed that contains a six-membered ring involving the ether oxygen next to the phosphonate group and also a seven-membered ring involving N3 of the adenine residue with a very significant formation degree of about 50%. Hence, PEEA(2-) is a truly ambivalent ligand, its properties being strongly dependent on the kind of metal ion involved. Comparisons with M2+ complexes formed by the dianions of 9-[2-(phosphonomethoxy)ethyl]adenine (PMEA) and related ligands reveal that five-membered chelates involving an ether-oxygen atom are considerably more stable than the corresponding six-membered ones. This observation offers an explanation of why PMEA is a nucleotide analogue with excellent antiviral properties and PEEA is not.
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Affiliation(s)
- Alfonso Fernández-Botello
- Department of Chemistry, Inorganic Chemistry, University of Basel, Spitalstrasse 51, CH-4056 Basel, Switzerland
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50
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Sigel H, Griesser R. Nucleoside 5'-triphosphates: self-association, acid-base, and metal ion-binding properties in solution. Chem Soc Rev 2005; 34:875-900. [PMID: 16172677 DOI: 10.1039/b505986k] [Citation(s) in RCA: 179] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Adenosine 5'-triphosphate (ATP(4-)) and related nucleoside 5'-triphosphates (NTP(4-)) serve as substrates in the form of metal ion complexes in enzymic reactions taking part thus in central metabolic processes. With this in mind, the coordination chemistry of NTPs is critically reviewed and the conditions are defined for studies aiming to describe the properties of monomeric complexes because at higher concentrations (>1 mM) self-stacking may take place. The metal ion (M(2+)) complexes of purine-NTPs are more stable than those of pyrimidine-NTPs; this stability enhancement is attributed, in accord with NMR studies, to macrochelate formation of the phosphate-coordinated M(2+) with N7 of the purine residue and the formation degrees of the resulting isomeric complexes are listed. Furthermore, the formation of mixed-ligand complexes (including also those with buffer molecules), the effect of a reduced solvent polarity on complex stability and structure (giving rise to selectivity), the use of nucleotide analogues as antiviral agents, and the effect of metal ions on group transfer reactions are summarized.
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Affiliation(s)
- Helmut Sigel
- Department of Chemistry, Inorganic Chemistry, University of Basel, Spitalstrasse 51, CH-4056 Basel, Switzerland.
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