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Moreira-Rodrigues M, Graça AL, Ferreira M, Afonso J, Serrão P, Morato M, Ferreirinha F, Correia-de-Sá P, Ebert SN, Moura D. Attenuated aortic vasodilation and sympathetic prejunctional facilitation in epinephrine-deficient mice: selective impairment of β2-adrenoceptor responses. J Pharmacol Exp Ther 2014; 351:243-9. [PMID: 25161169 DOI: 10.1124/jpet.114.217281] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
It has been suggested that there is a link between epinephrine synthesis and the development of β2-adrenoceptor-mediated effects, but it remains to be determined whether this development is triggered by epinephrine. The aim of this study was to characterize β-adrenoceptor-mediated relaxation and facilitation of norepinephrine release in the aorta of phenylethanolamine-N-methyltransferase-knockout (Pnmt-KO) mice. Catecholamines were quantified by reverse-phase high-performance liquid chromatography-electrochemical detection. Aortic rings were mounted in a myograph to determine concentration-response curves to selective β1- or β2-adrenoceptor agonists in the absence or presence of selective β1- or β2-adrenoceptor antagonists. Aortic rings were also preincubated with [(3)H]norepinephrine to measure tritium overflow elicited by electrical stimulation in the presence of increasing concentrations of nonselective β- or selective β2-adrenoceptor agonists. β2-Adrenoceptor protein density was evaluated by Western blotting and β2-adrenoceptor localization by immunohistochemistry. Epinephrine is absent in Pnmt-KO mice. The potency and the maximal effect of the β2-adrenoceptor agonist terbutaline were lower in Pnmt-KO than in wild-type (WT) mice. The selective β2-adrenoceptor antagonist ICI 118,551 [(±)-erythro-(S*,S*)-1-[2,3-(dihydro-7-methyl-1H-inden-4-yl)oxy]-3-[(1-methylethyl)amino]-2-butanol hydrochloride] antagonized the relaxation caused by terbutaline in WT but not in Pnmt-KO mice. Isoproterenol and terbutaline induced concentration-dependent increases in tritium overflow in WT mice only. β2-Adrenoceptor protein density was decreased in membrane aorta homogenates of Pnmt-KO mice, and this finding was supported by immunofluorescence confocal microscopy. In conclusion, epinephrine is crucial for β2-adrenoceptor-mediated vasodilation and facilitation of norepinephrine release. In the absence of epinephrine, β2-adrenoceptor protein density was decreased in aorta cell membranes, thus potentially hindering its functional activity.
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Affiliation(s)
- Mónica Moreira-Rodrigues
- Laboratory of General Physiology (M.M.-R.) and Laboratory of Pharmacology and Neurobiology (F.F., P.C.), Unit for Multidisciplinary Investigation in Biomedicine, Institute of Biomedical Sciences Abel Salazar, University of Porto; Department of Pharmacology and Therapeutics, Faculty of Medicine, University of Porto (A.L.G., M.F., J.A., P.S., D.M.); Neuropharmacology, Institute of Molecular and Cellular Biology, University of Porto (M.M., D.M.); Center for Drug Discovery and Innovative Medicines, University of Porto (M.M.-R., A.L.G., M.F., J.A., P.S., M.M., F.F., P.C., D.M.); Laboratory of Pharmacology, Department of Drug Sciences, Faculty of Pharmacy, University of Porto and Rede de Química e Tecnologia (REQUIMTE), Porto, Portugal (M.M.); and Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida (S.N.E.).
| | - Ana L Graça
- Laboratory of General Physiology (M.M.-R.) and Laboratory of Pharmacology and Neurobiology (F.F., P.C.), Unit for Multidisciplinary Investigation in Biomedicine, Institute of Biomedical Sciences Abel Salazar, University of Porto; Department of Pharmacology and Therapeutics, Faculty of Medicine, University of Porto (A.L.G., M.F., J.A., P.S., D.M.); Neuropharmacology, Institute of Molecular and Cellular Biology, University of Porto (M.M., D.M.); Center for Drug Discovery and Innovative Medicines, University of Porto (M.M.-R., A.L.G., M.F., J.A., P.S., M.M., F.F., P.C., D.M.); Laboratory of Pharmacology, Department of Drug Sciences, Faculty of Pharmacy, University of Porto and Rede de Química e Tecnologia (REQUIMTE), Porto, Portugal (M.M.); and Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida (S.N.E.)
| | - Marlene Ferreira
- Laboratory of General Physiology (M.M.-R.) and Laboratory of Pharmacology and Neurobiology (F.F., P.C.), Unit for Multidisciplinary Investigation in Biomedicine, Institute of Biomedical Sciences Abel Salazar, University of Porto; Department of Pharmacology and Therapeutics, Faculty of Medicine, University of Porto (A.L.G., M.F., J.A., P.S., D.M.); Neuropharmacology, Institute of Molecular and Cellular Biology, University of Porto (M.M., D.M.); Center for Drug Discovery and Innovative Medicines, University of Porto (M.M.-R., A.L.G., M.F., J.A., P.S., M.M., F.F., P.C., D.M.); Laboratory of Pharmacology, Department of Drug Sciences, Faculty of Pharmacy, University of Porto and Rede de Química e Tecnologia (REQUIMTE), Porto, Portugal (M.M.); and Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida (S.N.E.).
| | - Joana Afonso
- Laboratory of General Physiology (M.M.-R.) and Laboratory of Pharmacology and Neurobiology (F.F., P.C.), Unit for Multidisciplinary Investigation in Biomedicine, Institute of Biomedical Sciences Abel Salazar, University of Porto; Department of Pharmacology and Therapeutics, Faculty of Medicine, University of Porto (A.L.G., M.F., J.A., P.S., D.M.); Neuropharmacology, Institute of Molecular and Cellular Biology, University of Porto (M.M., D.M.); Center for Drug Discovery and Innovative Medicines, University of Porto (M.M.-R., A.L.G., M.F., J.A., P.S., M.M., F.F., P.C., D.M.); Laboratory of Pharmacology, Department of Drug Sciences, Faculty of Pharmacy, University of Porto and Rede de Química e Tecnologia (REQUIMTE), Porto, Portugal (M.M.); and Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida (S.N.E.)
| | - Paula Serrão
- Laboratory of General Physiology (M.M.-R.) and Laboratory of Pharmacology and Neurobiology (F.F., P.C.), Unit for Multidisciplinary Investigation in Biomedicine, Institute of Biomedical Sciences Abel Salazar, University of Porto; Department of Pharmacology and Therapeutics, Faculty of Medicine, University of Porto (A.L.G., M.F., J.A., P.S., D.M.); Neuropharmacology, Institute of Molecular and Cellular Biology, University of Porto (M.M., D.M.); Center for Drug Discovery and Innovative Medicines, University of Porto (M.M.-R., A.L.G., M.F., J.A., P.S., M.M., F.F., P.C., D.M.); Laboratory of Pharmacology, Department of Drug Sciences, Faculty of Pharmacy, University of Porto and Rede de Química e Tecnologia (REQUIMTE), Porto, Portugal (M.M.); and Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida (S.N.E.)
| | - Manuela Morato
- Laboratory of General Physiology (M.M.-R.) and Laboratory of Pharmacology and Neurobiology (F.F., P.C.), Unit for Multidisciplinary Investigation in Biomedicine, Institute of Biomedical Sciences Abel Salazar, University of Porto; Department of Pharmacology and Therapeutics, Faculty of Medicine, University of Porto (A.L.G., M.F., J.A., P.S., D.M.); Neuropharmacology, Institute of Molecular and Cellular Biology, University of Porto (M.M., D.M.); Center for Drug Discovery and Innovative Medicines, University of Porto (M.M.-R., A.L.G., M.F., J.A., P.S., M.M., F.F., P.C., D.M.); Laboratory of Pharmacology, Department of Drug Sciences, Faculty of Pharmacy, University of Porto and Rede de Química e Tecnologia (REQUIMTE), Porto, Portugal (M.M.); and Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida (S.N.E.)
| | - Fátima Ferreirinha
- Laboratory of General Physiology (M.M.-R.) and Laboratory of Pharmacology and Neurobiology (F.F., P.C.), Unit for Multidisciplinary Investigation in Biomedicine, Institute of Biomedical Sciences Abel Salazar, University of Porto; Department of Pharmacology and Therapeutics, Faculty of Medicine, University of Porto (A.L.G., M.F., J.A., P.S., D.M.); Neuropharmacology, Institute of Molecular and Cellular Biology, University of Porto (M.M., D.M.); Center for Drug Discovery and Innovative Medicines, University of Porto (M.M.-R., A.L.G., M.F., J.A., P.S., M.M., F.F., P.C., D.M.); Laboratory of Pharmacology, Department of Drug Sciences, Faculty of Pharmacy, University of Porto and Rede de Química e Tecnologia (REQUIMTE), Porto, Portugal (M.M.); and Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida (S.N.E.)
| | - Paulo Correia-de-Sá
- Laboratory of General Physiology (M.M.-R.) and Laboratory of Pharmacology and Neurobiology (F.F., P.C.), Unit for Multidisciplinary Investigation in Biomedicine, Institute of Biomedical Sciences Abel Salazar, University of Porto; Department of Pharmacology and Therapeutics, Faculty of Medicine, University of Porto (A.L.G., M.F., J.A., P.S., D.M.); Neuropharmacology, Institute of Molecular and Cellular Biology, University of Porto (M.M., D.M.); Center for Drug Discovery and Innovative Medicines, University of Porto (M.M.-R., A.L.G., M.F., J.A., P.S., M.M., F.F., P.C., D.M.); Laboratory of Pharmacology, Department of Drug Sciences, Faculty of Pharmacy, University of Porto and Rede de Química e Tecnologia (REQUIMTE), Porto, Portugal (M.M.); and Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida (S.N.E.)
| | - Steven N Ebert
- Laboratory of General Physiology (M.M.-R.) and Laboratory of Pharmacology and Neurobiology (F.F., P.C.), Unit for Multidisciplinary Investigation in Biomedicine, Institute of Biomedical Sciences Abel Salazar, University of Porto; Department of Pharmacology and Therapeutics, Faculty of Medicine, University of Porto (A.L.G., M.F., J.A., P.S., D.M.); Neuropharmacology, Institute of Molecular and Cellular Biology, University of Porto (M.M., D.M.); Center for Drug Discovery and Innovative Medicines, University of Porto (M.M.-R., A.L.G., M.F., J.A., P.S., M.M., F.F., P.C., D.M.); Laboratory of Pharmacology, Department of Drug Sciences, Faculty of Pharmacy, University of Porto and Rede de Química e Tecnologia (REQUIMTE), Porto, Portugal (M.M.); and Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida (S.N.E.)
| | - Daniel Moura
- Laboratory of General Physiology (M.M.-R.) and Laboratory of Pharmacology and Neurobiology (F.F., P.C.), Unit for Multidisciplinary Investigation in Biomedicine, Institute of Biomedical Sciences Abel Salazar, University of Porto; Department of Pharmacology and Therapeutics, Faculty of Medicine, University of Porto (A.L.G., M.F., J.A., P.S., D.M.); Neuropharmacology, Institute of Molecular and Cellular Biology, University of Porto (M.M., D.M.); Center for Drug Discovery and Innovative Medicines, University of Porto (M.M.-R., A.L.G., M.F., J.A., P.S., M.M., F.F., P.C., D.M.); Laboratory of Pharmacology, Department of Drug Sciences, Faculty of Pharmacy, University of Porto and Rede de Química e Tecnologia (REQUIMTE), Porto, Portugal (M.M.); and Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida (S.N.E.)
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Bobenchik AM, Choi JY, Mishra A, Rujan IN, Hao B, Voelker DR, Hoch JC, Mamoun CB. Identification of inhibitors of Plasmodium falciparum phosphoethanolamine methyltransferase using an enzyme-coupled transmethylation assay. BMC BIOCHEMISTRY 2010; 11:4. [PMID: 20085640 PMCID: PMC2824672 DOI: 10.1186/1471-2091-11-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2009] [Accepted: 01/19/2010] [Indexed: 01/20/2023]
Abstract
BACKGROUND The phosphoethanolamine methyltransferase, PfPMT, of the human malaria parasite Plasmodium falciparum, a member of a newly identified family of phosphoethanolamine methyltransferases (PMT) found solely in some protozoa, nematodes, frogs, and plants, is involved in the synthesis of the major membrane phospholipid, phosphatidylcholine. PMT enzymes catalyze a three-step S-adenosylmethionine-dependent methylation of the nitrogen atom of phosphoethanolamine to form phosphocholine. In P. falciparum, this activity is a limiting step in the pathway of synthesis of phosphatidylcholine from serine and plays an important role in the development, replication and survival of the parasite within human red blood cells. RESULTS We have employed an enzyme-coupled methylation assay to screen for potential inhibitors of PfPMT. In addition to hexadecyltrimethylammonium, previously known to inhibit PfPMT, two compounds dodecyltrimethylammonium and amodiaquine were also found to inhibit PfPMT activity in vitro. Interestingly, PfPMT activity was not inhibited by the amodiaquine analog, chloroquine, or other aminoquinolines, amino alcohols, or histamine methyltransferase inhibitors. Using yeast as a surrogate system we found that unlike wild-type cells, yeast mutants that rely on PfPMT for survival were sensitive to amodiaquine, and their phosphatidylcholine biosynthesis was inhibited by this compound. Furthermore NMR titration studies to characterize the interaction between amoidaquine and PfPMT demonstrated a specific and concentration dependent binding of the compound to the enzyme. CONCLUSION The identification of amodiaquine as an inhibitor of PfPMT in vitro and in yeast, and the biophysical evidence for the specific interaction of the compound with the enzyme will set the stage for the development of analogs of this drug that specifically inhibit this enzyme and possibly other PMTs.
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Affiliation(s)
- April M Bobenchik
- Department of Internal Medicine, Section of Infectious Diseases, Yale School of Medicine, 333 Cedar St., New Haven, 06052, USA
- Department of Genetics and Developmental Biology, University of Connecticut Health Center, 263 Farmington Ave., Farmington, 06030, USA
| | - Jae-Yeon Choi
- The Program in Cell Biology, Department of Medicine, National Jewish Medical and Research Center, 1400 Jackson St, Denver, 80206, USA
| | - Arunima Mishra
- Department of Genetics and Developmental Biology, University of Connecticut Health Center, 263 Farmington Ave., Farmington, 06030, USA
| | - Iulian N Rujan
- Department of Molecular, Microbial, and Structural Biology University of Connecticut Health Center, 263 Farmington Ave., Farmington, 06030, USA
| | - Bing Hao
- Department of Molecular, Microbial, and Structural Biology University of Connecticut Health Center, 263 Farmington Ave., Farmington, 06030, USA
| | - Dennis R Voelker
- The Program in Cell Biology, Department of Medicine, National Jewish Medical and Research Center, 1400 Jackson St, Denver, 80206, USA
| | - Jeffrey C Hoch
- Department of Molecular, Microbial, and Structural Biology University of Connecticut Health Center, 263 Farmington Ave., Farmington, 06030, USA
| | - Choukri Ben Mamoun
- Department of Internal Medicine, Section of Infectious Diseases, Yale School of Medicine, 333 Cedar St., New Haven, 06052, USA
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