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Affiliation(s)
- Zita Rádai
- Department of Organic Chemistry and Technology, Budapest University of Technology and Economics, Hungary
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Rufomycin Targets ClpC1 Proteolysis in Mycobacterium tuberculosis and M. abscessus. Antimicrob Agents Chemother 2019; 63:AAC.02204-18. [PMID: 30602512 PMCID: PMC6395927 DOI: 10.1128/aac.02204-18] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 12/14/2018] [Indexed: 11/29/2022] Open
Abstract
ClpC1 is an emerging new target for the treatment of Mycobacterium tuberculosis infections, and several cyclic peptides (ecumicin, cyclomarin A, and lassomycin) are known to act on this target. This study identified another group of peptides, the rufomycins (RUFs), as bactericidal to M. tuberculosis through the inhibition of ClpC1 and subsequent modulation of protein degradation of intracellular proteins. ClpC1 is an emerging new target for the treatment of Mycobacterium tuberculosis infections, and several cyclic peptides (ecumicin, cyclomarin A, and lassomycin) are known to act on this target. This study identified another group of peptides, the rufomycins (RUFs), as bactericidal to M. tuberculosis through the inhibition of ClpC1 and subsequent modulation of protein degradation of intracellular proteins. Rufomycin I (RUFI) was found to be a potent and selective lead compound for both M. tuberculosis (MIC, 0.02 μM) and Mycobacterium abscessus (MIC, 0.4 μM). Spontaneously generated mutants resistant to RUFI involved seven unique single nucleotide polymorphism (SNP) mutations at three distinct codons within the N-terminal domain of clpC1 (V13, H77, and F80). RUFI also significantly decreased the proteolytic capabilities of the ClpC1/P1/P2 complex to degrade casein, while having no significant effect on the ATPase activity of ClpC1. This represents a marked difference from ecumicin, which inhibits ClpC1 proteolysis but stimulates the ATPase activity, thereby providing evidence that although these peptides share ClpC1 as a macromolecular target, their downstream effects are distinct, likely due to differences in binding.
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3
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Rádai Z, Keglevich G. Synthesis and Reactions of α-Hydroxyphosphonates. Molecules 2018; 23:E1493. [PMID: 29925805 PMCID: PMC6099812 DOI: 10.3390/molecules23061493] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 06/11/2018] [Accepted: 06/16/2018] [Indexed: 12/18/2022] Open
Abstract
This review summarizes the main synthetic routes towards α-hydroxyphosphonates that are known as enzyme inhibitors, herbicides and antioxidants, moreover, a number of representatives express antibacterial or antifungal effect. Special attention is devoted to green chemical aspects. α-Hydroxyphosphonates are also versatile intermediates for other valuable derivatives. O-Alkylation and O-acylation are typical reactions to afford α-alkoxy-, or α-acyloxyphosphonates, respectively. The oxidation of hydroxyphosphonates leads to ketophosphonates. The hydroxy function at the α carbon atom of hydroxyphosphonates may be replaced by a halogen atom. α-Aminophosphonates formed in the nucleophilic substitution reaction of α-hydroxyphosphonates with primary or secondary amines are also potentially bioactive compounds. Another typical reaction is the base-catalyzed rearrangement of α-hydroxy-phosphonates to phosphates. Hydrolysis of the ester function of hydroxyphosphonates leads to the corresponding phosphonic acids.
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Affiliation(s)
- Zita Rádai
- Department of Organic Chemistry and Technology, Budapest University of Technology and Economics, 1521 Budapest, Hungary.
| | - György Keglevich
- Department of Organic Chemistry and Technology, Budapest University of Technology and Economics, 1521 Budapest, Hungary.
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4
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CD45 in human physiology and clinical medicine. Immunol Lett 2018; 196:22-32. [PMID: 29366662 DOI: 10.1016/j.imlet.2018.01.009] [Citation(s) in RCA: 135] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 01/18/2018] [Accepted: 01/19/2018] [Indexed: 01/20/2023]
Abstract
CD45 is an evolutionary highly conserved receptor protein tyrosine phosphatase exclusively expressed on all nucleated cells of the hematopoietic system. It is characterized by the expression of several isoforms, specific to a certain cell type and the developmental or activation status of the cell. CD45 is one of the key players in the initiation of T cell receptor signaling by controlling the activation of the Src family protein-tyrosine kinases Lck and Fyn. CD45 deficiency results in T- and B-lymphocyte dysfunction in the form of severe combined immune deficiency. It also plays a significant role in autoimmune diseases and cancer as well as in infectious diseases including fungal infections. The knowledge collected on CD45 biology is rather vast, but it remains unclear whether all findings in rodent immune cells also apply to human CD45. This review focuses on human CD45 expression and function and provides an overview on its ligands and role in human pathology.
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Arellano I, Rodríguez-Ramos F, González-Andrade M, Navarrete A, Sharma M, Rosas N, Sharma P. Ferrocenyl, Alkyl, and Aryl-Pyrido[2,3- d]Pyrimidines as Vasorelaxant of Smooth Muscle of Rat Aorta via cAMP Conservation Through Phosphodiesterase Inhibition. J Heterocycl Chem 2016. [DOI: 10.1002/jhet.2380] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Ivonne Arellano
- Instituto de Química; Universidad Nacional Autónoma de México; México Distrito Federal 04510 México
| | - Fernando Rodríguez-Ramos
- Departamento de Ciencias Naturales; DCNI, Universidad Autónoma Metropolitana; Unidad Cuajimalpa México Distrito Federal 05300 México
| | - Martín González-Andrade
- Facultad de Medicina, Departamento de Bioquímica; Universidad Nacional Autónoma de México; México Distrito Federal 04510 México
| | - Andrés Navarrete
- Facultad de Medicina, Departamento de Bioquímica; Universidad Nacional Autónoma de México; México Distrito Federal 04510 México
| | - Manju Sharma
- Ingeniería Bioquímica; Instituto Tecnológico Superior de Atlixco; Atlixco Puebla México
| | - Noé Rosas
- Instituto de Química; Universidad Nacional Autónoma de México; México Distrito Federal 04510 México
| | - Pankaj Sharma
- Instituto de Química; Universidad Nacional Autónoma de México; México Distrito Federal 04510 México
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Abstract
In recent years, chemical biology and chemical genomics have been increasingly applied to the field of microbiology to uncover new potential therapeutics as well as to probe virulence mechanisms in pathogens. The approach offers some clear advantages, as identified compounds (i) can serve as a proof of principle for the applicability of drugs to specific targets; (ii) can serve as conditional effectors to explore the function of their targets in vitro and in vivo; (iii) can be used to modulate gene expression in otherwise genetically intractable organisms; and (iv) can be tailored to a narrow or broad range of bacteria. This review highlights recent examples from the literature to illustrate how the use of small molecules has advanced discovery of novel potential treatments and has been applied to explore biological mechanisms underlying pathogenicity. We also use these examples to discuss practical considerations that are key to establishing a screening or discovery program. Finally, we discuss the advantages and challenges of different approaches and the methods that are emerging to address these challenges.
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Affiliation(s)
- Rebecca Anthouard
- Laboratory of Genetics & Molecular Biology of Intestinal Pathogens, Department of Microbiology & Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Victor J DiRita
- Laboratory of Genetics & Molecular Biology of Intestinal Pathogens, Department of Microbiology & Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
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Perron MD, Chowdhury S, Aubry I, Purisima E, Tremblay ML, Saragovi HU. Allosteric noncompetitive small molecule selective inhibitors of CD45 tyrosine phosphatase suppress T-cell receptor signals and inflammation in vivo. Mol Pharmacol 2014; 85:553-63. [PMID: 24473749 DOI: 10.1124/mol.113.089847] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
CD45 is a receptor-like member of the protein tyrosine phosphatase (PTP) family. We screened in silico for small molecules binding at a predicted allosteric pocket unique to the CD45 intracellular domain, and validated inhibitors by in vitro phosphatase assays. Compound 211 exhibited a CD45 IC50 value of 200 nM and had >100-fold selectivity over six related PTPs. The relevance of the allosteric pocket was verified through site-directed mutagenesis. Compound 211 has a noncompetitive mechanism of action, and it is extremely effective at preventing dephosphorylation of substrate Lck phosphotyrosine (pY)-505 versus preventing dephosphorylation of Lck pY-393. In cultured primary T cells, compound 211 prevents T-cell receptor-mediated activation of Lck, Zap-70, and mitogen-activated protein kinase, and interleukin-2 production. In a delayed-type hypersensitivity reaction in vivo, compound 211 abolished inflammation. This work demonstrates a novel approach to develop effective allosteric inhibitors that can be expanded to target the corresponding allosteric domains of other receptor PTPs.
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Affiliation(s)
- Michael D Perron
- Lady Davis Institute-Jewish General Hospital (M.P., S.C., H.U.S.), Departments of Pharmacology and Therapeutics (M.P., H.U.S.), Biochemistry (I.A., E.P., M.L.T.), and Oncology (H.U.S.), Goodman Cancer Research Center (M.L.T.), and Segal Cancer Center, McGill University, Montreal, Quebec, Canada (H.U.S.); and Biotechnology Research Institute, National Research Council Canada, Montreal, Quebec, Canada (E.P.)
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Synthesis, docking study and relaxant effect of 2-alkyl and 2-naphthylchromones on rat aorta and guinea-pig trachea through phosphodiesterase inhibition. Bioorg Chem 2013; 50:17-25. [PMID: 23933402 DOI: 10.1016/j.bioorg.2013.07.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Revised: 05/29/2013] [Accepted: 07/12/2013] [Indexed: 11/23/2022]
Abstract
Chromone (4), which form the base structure of various flavonoids isolated as natural products, is capable of relaxing smooth muscle. This is relevant to the treatment of high blood pressure, asthma and chronic obstructive pulmonary disease. The former disorder involves the contraction of vascular smooth muscle (VSM), and the latter two bronchoconstriction of airway smooth muscle (ASM). One of the principal mechanisms by which flavonoids relax muscle tissue is the inhibition of phosphodiesterases (PDEs), present in both VSM and ASM. Therefore, a study was designed to analyze the structure-activity relationship of chromone derivatives in vaso- and bronchorelaxation through the inhibition of PDE. Docking studies showed that these chromones bind at the catalytic site of PDEs. Consequently, we synthesized analogs of chromones substituted at position C-2 with alkyl and naphthyl groups. These compounds were synthesized from 2-hydroxyacetophenone and acyl chlorides in the presence of DBU and pyridine, modifying the methodology reported for the synthesis of 3-acylchromones by changing the reaction temperature from 80 to 30°C and using methylene chloride as solvent, yielding the corresponding phenolic esters 10a-10h. These compounds were cyclized with an equivalent of DBU, pyridine as solvent, and heated at reflux temperature, yielding the chromones 11a-11h. Evaluation of the vasorelaxant effect of 4, 11a-11h on rat aorta demonstrated that potency decreases with branched alkyl groups. Whereas the EC50 of compound 11d (substituted by an n-hexyl group) was 8.64±0.39 μM, that of 11f (substituted by an isobutyl group) was 14.58±0.64 μM. Contrarily, the effectiveness of the compound is directly proportional to the length of the alkyl chain, as evidenced by the increase in maximal effect of compound 11c versus 11d (66% versus 100%) and 11e versus 11f (60% versus 96%). With an aromatic group like naphthyl as the C-2 substituent, the effectiveness was only 43%. All compounds tested on guinea pig trachea showed less than 55% effectiveness. Compounds 4, 11a-11h were evaluated as PDE inhibitors in vitro, with 11d showing the greatest effect (73%), corroborating the importance of a long alkyl chain, which inhibits the decomposition of cGMP. Docking studies showed that the compound 11d was selective for the inhibition of PDE-5.
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Synthesis and evaluation of novel 2-pyridone derivatives as inhibitors of phosphodiesterase3 (PDE3): A target for heart failure and platelet aggregation. Bioorg Med Chem Lett 2012; 22:6010-5. [PMID: 22897945 DOI: 10.1016/j.bmcl.2012.05.019] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Revised: 04/16/2012] [Accepted: 05/02/2012] [Indexed: 01/24/2023]
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He R, Zeng LF, He Y, Zhang S, Zhang ZY. Small molecule tools for functional interrogation of protein tyrosine phosphatases. FEBS J 2012; 280:731-50. [PMID: 22816879 DOI: 10.1111/j.1742-4658.2012.08718.x] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The importance of protein tyrosine phosphatases (PTPs) in the regulation of cellular signalling is well established. Malfunction of PTP activity is also known to be associated with cancer, metabolic syndromes and autoimmune disorders, as well as neurodegenerative and infectious diseases. However, a detailed understanding of the roles played by the PTPs in normal physiology and in pathogenic conditions has been hampered by the absence of PTP-specific small molecule agents. In addition, the therapeutic benefits of modulating this target class are underexplored as a result of a lack of suitable chemical probes. Potent and specific PTP inhibitors could significantly facilitate functional analysis of the PTPs in complex cellular signal transduction pathways and may constitute valuable therapeutics in the treatment of several human diseases. We highlight the current challenges to and opportunities for developing PTP-specific small molecule agents. We also review available selective small molecule inhibitors developed for a number of PTPs, including PTP1B, TC-PTP, SHP2, lymphoid-specific tyrosine phosphatase, haematopoietic protein tyrosine phosphatase, CD45, PTPβ, PTPγ, PTPRO, Vaccinia H1-related phosphatase, mitogen-activated protein kinase phosphatase-1, mitogen-activated protein kinase phosphatase-3, Cdc25, YopH, mPTPA and mPTPB.
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Affiliation(s)
- Rongjun He
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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Weng SS, Lin GY, Li HC, Yang KC, Yang TM, Liu HC, Sie SH. Nafion®-supported oxovanadium-catalyzed hydrophosphonylation of aldehydes under solventless conditions. Appl Organomet Chem 2012. [DOI: 10.1002/aoc.2879] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Shiue-Shien Weng
- Department of Chemistry; ROC Military Academy; Fengshan District Kaohsiung City 83059 Taiwan
| | - Guan-Ying Lin
- Department of Chemistry; ROC Military Academy; Fengshan District Kaohsiung City 83059 Taiwan
| | - Hsin-Chun Li
- Department of Chemistry; ROC Military Academy; Fengshan District Kaohsiung City 83059 Taiwan
| | - Kuo-Chen Yang
- Department of Chemistry; ROC Military Academy; Fengshan District Kaohsiung City 83059 Taiwan
| | - Teng-Mao Yang
- Department of Chemistry; ROC Military Academy; Fengshan District Kaohsiung City 83059 Taiwan
| | - Hui-Chi Liu
- Department of Chemistry; ROC Military Academy; Fengshan District Kaohsiung City 83059 Taiwan
| | - Syuan-Hua Sie
- Department of Chemistry; ROC Military Academy; Fengshan District Kaohsiung City 83059 Taiwan
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Stanford SM, Krishnamurthy D, Falk MD, Messina R, Debnath B, Li S, Liu T, Kazemi R, Dahl R, He Y, Yu X, Chan AC, Zhang ZY, Barrios AM, Woods VL, Neamati N, Bottini N. Discovery of a novel series of inhibitors of lymphoid tyrosine phosphatase with activity in human T cells. J Med Chem 2011; 54:1640-54. [PMID: 21341673 PMCID: PMC3086468 DOI: 10.1021/jm101202j] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The lymphoid tyrosine phosphatase LYP, encoded by the PTPN22 gene, is a critical regulator of signaling in T cells and recently emerged as a candidate target for therapy of autoimmune diseases. Here, by library screening, we identified a series of noncompetitive inhibitors of LYP that showed activity in primary T cells. Kinetic analysis confirmed that binding of the compounds to the phosphatase is nonmutually exclusive with respect to a known bidentate competitive inhibitor. The mechanism of action of the lead inhibitor compound 4e was studied by a combination of hydrogen/deuterium-exchange mass spectrometry and molecular modeling. The results suggest that the inhibitor interacts critically with a hydrophobic patch located outside the active site of the phosphatase. Targeting of secondary allosteric sites is viewed as a promising yet unexplored approach to develop pharmacological inhibitors of protein tyrosine phosphatases. Our novel scaffold could be a starting point to attempt development of "nonactive site" anti-LYP pharmacological agents.
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Affiliation(s)
- Stephanie M. Stanford
- Institute for Genetic Medicine, University of Southern California, Los Angeles, California 90033, United States
- Division of Cell Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California 92037, United States
| | - Divya Krishnamurthy
- Institute for Genetic Medicine, University of Southern California, Los Angeles, California 90033, United States
- Department of Medicinal Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
| | - Matthew D. Falk
- Division of Cell Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California 92037, United States
| | - Rossella Messina
- Division of Cell Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California 92037, United States
| | - Bikash Debnath
- Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, California 90033, United States
| | - Sheng Li
- Department of Medicine, University of California San Diego, La Jolla, California 92093, United States
| | - Tong Liu
- Department of Medicine, University of California San Diego, La Jolla, California 92093, United States
| | - Roza Kazemi
- Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, California 90033, United States
| | - Russell Dahl
- CPCCG, Sanford-Burnham Medical Research Institute, La Jolla, California 92037, United States
| | - Yantao He
- Department of Biochemistry and Molecular Biology, Indiana University, Indianapolis, Indiana 46202, United States
| | - Xiao Yu
- Department of Biochemistry and Molecular Biology, Indiana University, Indianapolis, Indiana 46202, United States
| | - Andrew C. Chan
- Department of Immunology, Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - Zhong-Yin Zhang
- Department of Biochemistry and Molecular Biology, Indiana University, Indianapolis, Indiana 46202, United States
| | - Amy M. Barrios
- Department of Medicinal Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
| | - Virgil L. Woods
- Department of Medicine, University of California San Diego, La Jolla, California 92093, United States
| | - Nouri Neamati
- Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, California 90033, United States
| | - Nunzio Bottini
- Institute for Genetic Medicine, University of Southern California, Los Angeles, California 90033, United States
- Division of Cell Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California 92037, United States
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Milrinone enhances relaxation to prostacyclin and iloprost in pulmonary arteries isolated from lambs with persistent pulmonary hypertension of the newborn. Pediatr Crit Care Med 2009; 10:106-12. [PMID: 19057444 PMCID: PMC2741129 DOI: 10.1097/pcc.0b013e3181936aee] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
UNLABELLED Prostacyclin is a pulmonary vasodilator and is produced by prostacyclin synthase and stimulates adenylate cyclase (AC) via the prostacyclin receptor (IP) to produce cAMP. Forskolin is a direct stimulant of AC. Phosphodiesterase 3 hydrolyzes cAMP and is inhibited by milrinone. OBJECTIVE To characterize the prostacyclin-AC-cAMP pathway in the ovine ductal ligation model of persistent pulmonary hypertension of the newborn (PPHN). SETTING University-based laboratory animal facility. SUBJECTS Lambs delivered to time-dated pregnant ewes. INTERVENTIONS Fifth generation pulmonary arteries (PA) and lung parenchyma were isolated from control fetal lambs (n = 8) and fetal lambs with PPHN induced by antenatal ductal ligation (n = 9). We studied relaxation responses to various agonists (milrinone, forskolin, prostacyclin, and iloprost, a prostacyclin analog) that increase cAMP in PA after half-maximal constriction with norepinephrine and pretreatment with propranolol +/- indomethacin. Lung protein levels of prostacyclin synthase, IP, AC2, and phosphodiesterase 3A were analyzed by Western blot and cAMP by enzyme-linked immunoassay. MAIN RESULTS Milrinone relaxed control and PPHN PA and pretreatment with indomethacin significantly impaired this response. Relaxation to milrinone, prostacyclin, and iloprost were significantly impaired in PA from PPHN lambs. Pretreatment with milrinone markedly enhanced relaxation to prostacyclin and iloprost in PPHN PA, similar to relaxation in control PA. Relaxation to forskolin was similar in control and PPHN PAs indicating normal AC activity. Protein levels of prostacyclin synthase and IP were decreased in PPHN lungs compared with control, but AC2, cAMP, and phosphodiesterase 3A remained unchanged. CONCLUSIONS Prostacyclin and iloprost are dilators of PAs from PPHN lambs and their effect is enhanced by milrinone. This combination therapy may be an effective strategy in the management of patients with PPHN.
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Karvinen J, Laitala V, Mäkinen ML, Mulari O, Tamminen J, Hermonen J, Hurskainen P, Hemmilä I. Fluorescence Quenching-Based Assays for Hydrolyzing Enzymes. Application of Time-Resolved Fluorometry in Assays for Caspase, Helicase, and Phosphatase. Anal Chem 2004; 76:1429-36. [PMID: 14987100 DOI: 10.1021/ac030234b] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We have developed assay technologies to measure hydrolyzing enzymes based on homogeneous time-resolved fluorescence quenching (TruPoint). High sensitivity was obtained using fluorescent europium chelates as labels, internally quenched by suitable quenchers and released upon enzymatic reaction. This approach allows robust and sensitive monitoring of low enzyme activities. The assay technology and the choice of donor-acceptor pairs were evaluated in three different enzymatic assays, a protease related to apoptosis, helicase involved in DNA unwinding, and phosphatase having an important role in cellular signaling cascades. All the assays produced an increasing signal, were sensitive, and had a good dynamic range. There were significant differences in optimized quenchers for each of the assays depending on the size, flexibility, and rigidity of the substrates. Also, clear differences in the energy-transfer reactions, their requirements for spectral overlapping, ionic interactions, and energy-transfer distances were found. Each of the enzymatic assays was briefly tested in a high-throughput screening environment by analyzing signal dynamics and statistical relevance as Z' factors.
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Affiliation(s)
- Jarkko Karvinen
- PerkinElmer Life and Analytical Sciences, Wallac Oy, P.O. Box 10, FIN-20101 Turku, Finland.
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Abstract
Regulation of tyrosine phosphorylation is a critical control point for integration of environmental signals into cellular responses. This regulation is mediated by the reciprocal actions of protein tyrosine kinases and phosphatases. CD45, the first and prototypic receptor-like protein tyrosine phosphatase, is expressed on all nucleated hematopoietic cells and plays a central role in this process. Studies of CD45 mutant cell lines, CD45-deficient mice, and CD45-deficient humans initially demonstrated the essential role of CD45 in antigen receptor signal transduction and lymphocyte development. It is now known that CD45 also modulates signals emanating from integrin and cytokine receptors. Recent work has focused on regulation of CD45 expression and alternative splicing, isoform-specific differences in signal transduction, and regulation of phosphatase activity. From these studies, a model is emerging in which CD45 affects cellular responses by controlling the relative threshold of sensitivity to external stimuli. Perturbation of this function may contribute to autoimmunity, immunodeficiency, and malignancy. Moreover, recent advances suggest that modulation of CD45 function can have therapeutic benefit in many disease states.
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Schafer PH, Gandhi AK, Loveland MA, Chen RS, Man HW, Schnetkamp PPM, Wolbring G, Govinda S, Corral LG, Payvandi F, Muller GW, Stirling DI. Enhancement of cytokine production and AP-1 transcriptional activity in T cells by thalidomide-related immunomodulatory drugs. J Pharmacol Exp Ther 2003; 305:1222-32. [PMID: 12649301 DOI: 10.1124/jpet.102.048496] [Citation(s) in RCA: 149] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
CC-4047 (Actimid) and CC-5013 (Revimid) belong to a class of thalidomide analogs collectively known as the immunomodulatory drugs (IMiDs), which are currently being assessed in the treatment of patients with multiple myeloma and other cancers. IMiDs potently enhance T cell and natural killer cell responses and inhibit tumor necrosis factor-alpha, interleukin (IL)-1 beta, and IL-12 production from LPS-stimulated peripheral blood mononuclear cells. However, the molecular mechanism of action for these compounds is unknown. Herein, we report on the ability of the IMiDs to up-regulate production of IL-2 from activated human CD4+ and CD8+ peripheral blood T cells, production of IL-2 and IFN-gamma from T helper (Th)1-type cells, and production of IL-5 and IL-10 from Th2-type cells. Elevation of IL-2 production from Jurkat T cells was observed as early as 6 h poststimulation and correlated with an increase in IL-2 promoter activity that was dependent upon the proximal but not the distal AP-1 binding site. The IMiDs enhanced AP-1-driven transcriptional activity 2- to 4-fold after 6 h of T cell stimulation, and their relative potencies for AP-1 activation correlated with their potencies for increased IL-2 production in Jurkat T cells and in CD4+ or CD8+ human peripheral blood T cells. The most potent of these IMiDs, CC-4047, had no effect on nuclear factor of activated T cells transcriptional activity, calcium signaling, or phosphorylation of extracellular signal-regulated kinase 1/2, c-Jun NH2-terminal kinase 1/2, p38 mitogen-activated protein kinase, or c-Jun/Jun D in Jurkat T cells. These data suggest that IMiDs increase T cell cytokine production by potentiating AP-1 transcriptional activity.
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Affiliation(s)
- Peter H Schafer
- Celgene Corporation, 7 Powder Horn Dr., Warren, NJ 07059, USA.
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Huang P, Ramphal J, Wei J, Liang C, Jallal B, McMahon G, Tang C. Structure-based design and discovery of novel inhibitors of protein tyrosine phosphatases. Bioorg Med Chem 2003; 11:1835-49. [PMID: 12659770 DOI: 10.1016/s0968-0896(03)00039-7] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Protein tyrosine phosphatases (PTPs) are important in the regulation of signal transduction processes. Certain enzymes of this class are considered as potential therapeutic targets in the treatment of a variety of diseases such as diabetes, inflammation, and cancer. However, many PTP inhibitors identified to date are peptide-based and contain a highly charged phosphate-mimicking component. These compounds usually lack membrane permeability and this limits their utility in the inhibition of intracellular phosphatases. In the present study, we have used structure-based design and modeling techniques to explore catalytic-site directed, reversible inhibitors of PTPs. Employing a non-charged phosphate mimic and non-peptidyl structural components, we have successfully designed and synthesized a novel series of trifluoromethyl sulfonyl and trifluoromethyl sulfonamido compounds as PTP inhibitors. This is the first time that an uncharged phosphate mimic is reported in the literature for general, reversible, and substrate-competitive inhibition of PTPs. It is an important discovery because the finding may provide a paradigm for the development of phosphatase inhibitors that enter cells and modify signal transduction.
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Affiliation(s)
- Ping Huang
- SUGEN, Inc., 230 East Grand Ave., South San Francisco, CA 94080, USA.
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Li Z, Yeo SL, Pallen CJ, Ganesan A. Solid-phase synthesis of potential protein tyrosine phosphatase inhibitors via the Ugi four-component condensation. Bioorg Med Chem Lett 1998; 8:2443-6. [PMID: 9873558 DOI: 10.1016/s0960-894x(98)00408-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A library of 108 alpha,alpha-difluoromethylenephosphonic acids was prepared by Ugi four-component condensation using Rink-NH2 resin, 4-[(diethoxyphosphinyl) difluoromethyl]benzoic acid, and a set of 18 aldehydes and 6 isonitriles. Following resin cleavage, the diethylphosphonate esters were hydrolyzed with trimethylsilyl bromide to yield the free acids which were assayed for inhibition of PTP alpha, PTP beta and PTP epsilon.
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Affiliation(s)
- Z Li
- Institute of Molecular and Cell Biology, National University of Singapore
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