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Legros C, Yous S, Boutin JA. Alternative Ligands at Melatonin Receptors. Methods Mol Biol 2022; 2550:151-162. [PMID: 36180688 DOI: 10.1007/978-1-0716-2593-4_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Melatonin (N-acetyl-5-methoxytryptamine) is a neurohormone that possesses a wide range of biological effects. Most of the main recognized effects of this hormone in mammals are due to its interaction with two G protein-coupled receptors, MT1 and MT2. Ligand-binding studies have been based on the use of its radioligand analog, 2[125I]-iodomelatonin, a super agonist discovered in the early 1990s. This compound has been used in most of the binding studies reported in the literature. Nevertheless, more recently other possibilities arose. This chapter is a brief summary of those alternative radioligands and of their benefits one can find in using them.
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Affiliation(s)
- Céline Legros
- Pole d'expertise Biotechnologie, Chimie & Biologie, Institut de Recherches Servier, Croissy-sur-Seine, France
- Eurofins Discovery, Celle l'Evescault, France
| | - Said Yous
- UMR-S 1172-LiNC-Lille Neuroscience & Cognition, Lille, France
| | - Jean A Boutin
- Pole d'expertise Biotechnologie, Chimie & Biologie, Institut de Recherches Servier, Croissy-sur-Seine, France.
- PHARMADEV (Pharmacochimie et biologie pour le développement), Faculté de Pharmacie, Toulouse, France.
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2
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Legros C, Dupuis P, Ferry G, Boutin JA. Measuring Binding at the Putative Melatonin Receptor MT3. Methods Mol Biol 2022; 2550:283-289. [PMID: 36180699 DOI: 10.1007/978-1-0716-2593-4_30] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Melatonin, (N-acetyl-5-methoxytryptamine), is a neurohormone which possesses a wide range of biological effects. The effects mediated by melatonin are in part attributed to the antioxidant properties of the molecule. For a long time, melatonin had been described as a ligand of a putative "receptor" present in mammalian brains named MT3. Several studies were thus carried out with the goal of clarifying the nature of this melatonin "receptor." The experimental setup of the binding measurements is unusual. The present chapter aims at describing this technique. This binding site was confirmed independently by several groups, and it was eventually demonstrated that MT3 was the enzyme quinone reductase 2 (NQO2).
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Affiliation(s)
- Céline Legros
- Eurofins, Discovery, Eurofins Cerep, Celle-Levescault, France
| | - Philippe Dupuis
- Eurofins, Discovery, Eurofins Cerep, Celle-Levescault, France
| | - Gilles Ferry
- Pole d'expertise Biotechnologie, Chimie & Biologie, Institut de Recherches Servier, Croissy-sur-Seine, France
| | - Jean A Boutin
- Pole d'expertise Biotechnologie, Chimie & Biologie, Institut de Recherches Servier, Croissy-sur-Seine, France.
- Pharma-Dev, UMR 152, Université de Toulouse, Toulouse, France.
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3
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Boutin JA, Jockers R. Melatonin controversies, an update. J Pineal Res 2021; 70:e12702. [PMID: 33108677 DOI: 10.1111/jpi.12702] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 10/11/2020] [Accepted: 10/20/2020] [Indexed: 12/13/2022]
Abstract
Melatonin was discovered more than 60 years ago. Since then, several seminal discoveries have allowed us to define its function as a neuroendocrine hormone and its molecular targets in mammals and many other species. However, many fundamental issues have not yet been solved such as the subcellular localization of melatonin synthesis and the full spectrum of its molecular targets. In addition, a considerable number of controversies persist in the field, mainly concerning how many functions melatonin has. Altogether, this illustrates how "immature" the field still is. The intention of this opinion article is to note the controversies and limitations in the field, to initiate a discussion and to make proposals/guidelines to overcome them and move the field forward.
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Affiliation(s)
- Jean A Boutin
- Institut de Recherches Internationales SERVIER, Suresnes Cedex, France
| | - Ralf Jockers
- INSERM, CNRS, Institut Cochin, Université de Paris, Paris, France
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Cecon E, Legros C, Boutin JA, Jockers R. Journal of pineal research guideline for authors: Defining and characterizing melatonin targets. J Pineal Res 2021; 70:e12712. [PMID: 33332653 DOI: 10.1111/jpi.12712] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 12/04/2020] [Accepted: 12/05/2020] [Indexed: 12/15/2022]
Abstract
A multitude of effects has been attributed to melatonin at pmol/L to mmol/L concentrations. More than fifteen targets have been proposed for melatonin but only few of them are well characterized. The current guidelines intend to provide a framework to improve and rationalize the characterization of melatonin targets and effects. They should be considered as mandatory guidelines and minimum requirements for manuscripts submitted to the Journal of Pineal Research.
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Affiliation(s)
- Erika Cecon
- Institut Cochin, CNRS, INSERM, Université de Paris, Paris, France
| | - Céline Legros
- Institut de Recherches SERVIER, Croissy-sur-Seine, France
| | - Jean A Boutin
- Institut de Recherches SERVIER, Croissy-sur-Seine, France
| | - Ralf Jockers
- Institut Cochin, CNRS, INSERM, Université de Paris, Paris, France
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5
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Protective effects of melatonin on male fertility preservation and reproductive system. Cryobiology 2020; 95:1-8. [DOI: 10.1016/j.cryobiol.2020.01.018] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 01/25/2020] [Indexed: 12/17/2022]
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Navarro Gil FJ, Huete-Toral F, Crooke A, Dominguez Godinez CO, Carracedo G, Pintor J. Effect of Melatonin and Its Analogs on Tear Secretion. J Pharmacol Exp Ther 2019; 371:186-190. [PMID: 31371479 DOI: 10.1124/jpet.119.259192] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 07/30/2019] [Indexed: 11/22/2022] Open
Abstract
Melatonin has been shown to enhance tear secretion associated with dinucleotide diadenosine tetraphosphate. This study investigated the isolated action of melatonin and its analogs, agomelatine, N-butanoyl-2-(2-methoxy-6H-isoindolo[2,1-a]indol-11-yl) ethanamine (IIK7), and 5-methoxycarbonylamino-N-cetyltryptamine (5-MCA-NAT) (10 µl at 100 µM), on tear secretion when applied topically in the rabbit cornea and its relationship with the melatonin MT1, MT2, and MT3/quinone reductase QR2 receptors. The results showed a significant increase in tear secretion, with a maximal effect at 60 minutes for the agonists (138.9% ± 6.5%, 128.9% ± 6.4%, and 120.0% ± 5.2%, respectively; P < 0.05; 100% control) but not for melatonin (101.6% ± 7.9%; P > 0.05). Agonist action was tested combined with the antagonists DH97 (MT2 selective), prazosin (MT3/QR2 inhibitor), and luzindole (nonselective MT membrane receptor) (10 µl at 100 µM). DH97 reversed the effect of agomelatine, IIK7, and 5-MCA-NAT up to 30.85% ± 7.6%,108% ± 7.2%, and 87.01% ± 7.6%, respectively (P < 0.05; 100% control). Luzindole antagonized agomelatine and 5-MCA-NAT up to 67.35% ± 7.6% and 92.12% ± 8%, respectively (P < 0.05). Prazosin only reversed 5-MCA-NAT action up to 84.2% ± 7.7% (P < 0.05). These results suggest different pathways for the agonists to act through MT membrane receptors. Therefore, agomelatine, IIK7, and 5-MCA-NAT act through MT membrane receptors as secretagogues of tear secretion, and these analogs could be considered excellent therapeutic candidates for dry eye treatment. SIGNIFICANCE STATEMENT: Currently, dry eye with aqueous deficit is treated by adding artificial tears palliatively. This study shows that topical installation of three melatonin analogs (agomelatine, IIK7, and 5-MCA-NAT), but not melatonin, in therapeutic doses in the rabbit cornea significantly increases tear production, acting through different melatonin membrane receptor subtypes. Therefore, this study suggests that melatoninergic compounds could be considered excellent therapeutic candidates for dry eye treatment and ocular surface diseases occurring with a reduction in tear production.
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Affiliation(s)
- Francisco Javier Navarro Gil
- Departamentos de Optometría y Visión (F.J.N.G., C.O.D.G., G.C.) and Bioquímica y Biología Molecular (F.H.-T., A.C., J.P.), Facultad de Óptica y Optometría, Universidad Complutense de Madrid, Madrid, Spain
| | - Fernando Huete-Toral
- Departamentos de Optometría y Visión (F.J.N.G., C.O.D.G., G.C.) and Bioquímica y Biología Molecular (F.H.-T., A.C., J.P.), Facultad de Óptica y Optometría, Universidad Complutense de Madrid, Madrid, Spain
| | - Almudena Crooke
- Departamentos de Optometría y Visión (F.J.N.G., C.O.D.G., G.C.) and Bioquímica y Biología Molecular (F.H.-T., A.C., J.P.), Facultad de Óptica y Optometría, Universidad Complutense de Madrid, Madrid, Spain
| | - Carmen Olalla Dominguez Godinez
- Departamentos de Optometría y Visión (F.J.N.G., C.O.D.G., G.C.) and Bioquímica y Biología Molecular (F.H.-T., A.C., J.P.), Facultad de Óptica y Optometría, Universidad Complutense de Madrid, Madrid, Spain
| | - Gonzalo Carracedo
- Departamentos de Optometría y Visión (F.J.N.G., C.O.D.G., G.C.) and Bioquímica y Biología Molecular (F.H.-T., A.C., J.P.), Facultad de Óptica y Optometría, Universidad Complutense de Madrid, Madrid, Spain
| | - Jesús Pintor
- Departamentos de Optometría y Visión (F.J.N.G., C.O.D.G., G.C.) and Bioquímica y Biología Molecular (F.H.-T., A.C., J.P.), Facultad de Óptica y Optometría, Universidad Complutense de Madrid, Madrid, Spain
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7
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An insight into the scientific background and future perspectives for the potential uses of melatonin. ACTA ACUST UNITED AC 2019. [DOI: 10.1016/j.ejbas.2015.05.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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8
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Boutin JA, Ferry G. Is There Sufficient Evidence that the Melatonin Binding SiteMT3Is Quinone Reductase 2? J Pharmacol Exp Ther 2018; 368:59-65. [DOI: 10.1124/jpet.118.253260] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 10/26/2018] [Indexed: 12/15/2022] Open
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9
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viviD D, Bentley GE. Seasonal Reproduction in Vertebrates: Melatonin Synthesis, Binding, and Functionality Using Tinbergen's Four Questions. Molecules 2018; 23:E652. [PMID: 29534047 PMCID: PMC6017951 DOI: 10.3390/molecules23030652] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 02/11/2018] [Accepted: 02/13/2018] [Indexed: 12/15/2022] Open
Abstract
One of the many functions of melatonin in vertebrates is seasonal reproductive timing. Longer nights in winter correspond to an extended duration of melatonin secretion. The purpose of this review is to discuss melatonin synthesis, receptor subtypes, and function in the context of seasonality across vertebrates. We conclude with Tinbergen's Four Questions to create a comparative framework for future melatonin research in the context of seasonal reproduction.
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Affiliation(s)
- Dax viviD
- Berkeley Department of Integrative Biology, University of California, Berkeley, CA 94720, USA.
| | - George E Bentley
- Berkeley Department of Integrative Biology, University of California, Berkeley, CA 94720, USA.
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10
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Andrés-Guerrero V, Bravo-Osuna I, Pastoriza P, Molina-Martinez IT, Herrero-Vanrell R. Novel technologies for the delivery of ocular therapeutics in glaucoma. J Drug Deliv Sci Technol 2017. [DOI: 10.1016/j.jddst.2017.07.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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11
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Crooke A, Huete-Toral F, Colligris B, Pintor J. The role and therapeutic potential of melatonin in age-related ocular diseases. J Pineal Res 2017; 63. [PMID: 28658514 DOI: 10.1111/jpi.12430] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 06/23/2017] [Indexed: 12/20/2022]
Abstract
The eye is continuously exposed to solar UV radiation and pollutants, making it prone to oxidative attacks. In fact, oxidative damage is a major cause of age-related ocular diseases including cataract, glaucoma, age-related macular degeneration, and diabetic retinopathy. As the nature of lens cells, trabecular meshwork cells, retinal ganglion cells, retinal pigment epithelial cells, and photoreceptors is postmitotic, autophagy plays a critical role in their cellular homeostasis. In age-related ocular diseases, this process is impaired, and thus, oxidative damage becomes irreversible. Other conditions such as low-grade chronic inflammation and angiogenesis also contribute to the development of retinal diseases (glaucoma, age-related macular degeneration and diabetic retinopathy). As melatonin is known to have remarkable qualities such as antioxidant/antinitridergic, mitochondrial protector, autophagy modulator, anti-inflammatory, and anti-angiogenic, it can represent a powerful tool to counteract all these diseases. The present review analyzes the role and therapeutic potential of melatonin in age-related ocular diseases, focusing on nitro-oxidative stress, autophagy, inflammation, and angiogenesis mechanisms.
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Affiliation(s)
- Almudena Crooke
- Department of Biochemistry and Molecular Biology IV, Group Ocupharm, Faculty of Optics and Optometry, Universidad Complutense de Madrid, Madrid, Spain
| | - Fernando Huete-Toral
- Department of Biochemistry and Molecular Biology IV, Group Ocupharm, Faculty of Optics and Optometry, Universidad Complutense de Madrid, Madrid, Spain
| | - Basilio Colligris
- Department of Biochemistry and Molecular Biology IV, Group Ocupharm, Faculty of Optics and Optometry, Universidad Complutense de Madrid, Madrid, Spain
| | - Jesús Pintor
- Department of Biochemistry and Molecular Biology IV, Group Ocupharm, Faculty of Optics and Optometry, Universidad Complutense de Madrid, Madrid, Spain
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12
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Jockers R, Delagrange P, Dubocovich ML, Markus RP, Renault N, Tosini G, Cecon E, Zlotos DP. Update on melatonin receptors: IUPHAR Review 20. Br J Pharmacol 2016; 173:2702-25. [PMID: 27314810 DOI: 10.1111/bph.13536] [Citation(s) in RCA: 272] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 05/15/2016] [Accepted: 05/19/2016] [Indexed: 02/06/2023] Open
Abstract
Melatonin receptors are seven transmembrane-spanning proteins belonging to the GPCR superfamily. In mammals, two melatonin receptor subtypes exist - MT1 and MT2 - encoded by the MTNR1A and MTNR1B genes respectively. The current review provides an update on melatonin receptors by the corresponding subcommittee of the International Union of Basic and Clinical Pharmacology. We will highlight recent developments of melatonin receptor ligands, including radioligands, and give an update on the latest phenotyping results of melatonin receptor knockout mice. The current status and perspectives of the structure of melatonin receptor will be summarized. The physiological importance of melatonin receptor dimers and biologically important and type 2 diabetes-associated genetic variants of melatonin receptors will be discussed. The role of melatonin receptors in physiology and disease will be further exemplified by their functions in the immune system and the CNS. Finally, antioxidant and free radical scavenger properties of melatonin and its relation to melatonin receptors will be critically addressed.
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Affiliation(s)
- Ralf Jockers
- Inserm, U1016, Institut Cochin, Paris, France.,CNRS UMR 8104, Paris, France.,University Paris Descartes, Paris, France
| | | | - Margarita L Dubocovich
- Department Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Science, University at Buffalo (SUNY), Buffalo, USA
| | - Regina P Markus
- Institute of Biosciences, University of São Paulo, São Paulo, Brazil
| | | | - Gianluca Tosini
- Neuroscience Institute and Department of Pharmacology and Toxicology, Morehouse School of Medicine, Atlanta, GA, USA
| | - Erika Cecon
- Inserm, U1016, Institut Cochin, Paris, France.,CNRS UMR 8104, Paris, France.,University Paris Descartes, Paris, France
| | - Darius P Zlotos
- Department of Pharmaceutical Chemistry, The German University in Cairo, New Cairo City, Cairo, Egypt
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Martinez-Aguila A, Fonseca B, Perez de Lara MJ, Pintor J. Effect of Melatonin and 5-Methoxycarbonylamino-N-Acetyltryptamine on the Intraocular Pressure of Normal and Glaucomatous Mice. ACTA ACUST UNITED AC 2016; 357:293-9. [DOI: 10.1124/jpet.115.231456] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 03/02/2016] [Indexed: 01/02/2023]
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14
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Huete-Toral F, Crooke A, Martínez-Águila A, Pintor J. Melatonin receptors trigger cAMP production and inhibit chloride movements in nonpigmented ciliary epithelial cells. J Pharmacol Exp Ther 2014; 352:119-28. [PMID: 25344385 DOI: 10.1124/jpet.114.218263] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Melatonin and its analog 5-MCA-NAT (5-methylcarboxyamino-N-acetyl tryptamine) are active compounds reducing intraocular pressure (IOP). This action is mediated through MT2 and the putative MT3 melatonin receptor, producing a transient reduction of IOP that lasts for a few hours and has not yet been characterized. The use of melatonin and its analog are causing a decrease in chloride efflux from rabbit nonpigmented epithelial cells (NPE), possibly explaining the decrease in IOP. Melatonin and 5-MCA-NAT inhibited rabbit NPE chloride release in a concentration-dependent manner, whereas the pD2 values were between 4.5 ± 1.2 and 4.4 ± 1.0, respectively. Melatonin hypotensive action was enhanced by the presence of MT2 antagonists, such as DH97 (N-pentanoyl-2-benzyltryptamine) and 4-P-P-DOT (4-phenyl-2-propionamidotetralin) and by the nonselective melatonin receptor antagonist luzindole. Prazosin (1.5 µM) partially reverses the melatonin action by acting as a selective MT3 antagonist. However, at 15 nM it acts as an α-adrenergic receptor antagonist, enhancing the melatonin effect. Regarding the intracellular pathways triggered by melatonin receptors, neither phospholipase C/protein kinase C pathway nor the canonical reduction of intracellular cAMP was responsible for melatonin or 5-MCA-NAT actions. On the contrary, the application of these substances produced a concentration-dependent increase of cAMP, with pD2 values of 4.6 ± 0.2 and 4.9 ± 0.7 for melatonin and 5-MCA-NAT, respectively. In summary, melatonin reduces the release of chloride concomitantly to cAMP generation. The reduction of Cl(-) secretion accounts for a decrease in the water outflow and therefore a decrease in aqueous humor production. This could be one of the main mechanisms responsible for the reduction of IOP after application of melatonin and 5-MCA-NAT.
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Affiliation(s)
- Fernando Huete-Toral
- Departamento de Bioquímica y Biología Molecular IV, Facultad de Óptica y Optometría, Universidad Complutense de Madrid, Madrid, Spain
| | - Almudena Crooke
- Departamento de Bioquímica y Biología Molecular IV, Facultad de Óptica y Optometría, Universidad Complutense de Madrid, Madrid, Spain
| | - Alejandro Martínez-Águila
- Departamento de Bioquímica y Biología Molecular IV, Facultad de Óptica y Optometría, Universidad Complutense de Madrid, Madrid, Spain
| | - Jesús Pintor
- Departamento de Bioquímica y Biología Molecular IV, Facultad de Óptica y Optometría, Universidad Complutense de Madrid, Madrid, Spain
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Sampaio LDFS, Mesquita FP, de Sousa PRM, Silva JL, Alves CN. The melatonin analog 5-MCA-NAT increases endogenous dopamine levels by binding NRH:quinone reductase enzyme in the developing chick retina. Int J Dev Neurosci 2014; 38:119-26. [PMID: 25218627 DOI: 10.1016/j.ijdevneu.2014.09.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 08/22/2014] [Accepted: 09/02/2014] [Indexed: 12/15/2022] Open
Abstract
NRH:quinone reductase (QR2) is present in the retinas of embryonic and post-hatched (PH) chicks. 5-Methoxycarbonylamino-N-acetyltryptamine (5-MCA-NAT) is a QR2 ligand that increases cAMP levels in developing retinas, but it does not affect cAMP levels in CHO-QR2 cells. The dopamine quinone reductase activity of QR2 retrieves dopamine, which increases cAMP levels in developing retinas. The objective of the present study was to investigate whether 5-MCA-NAT increases endogenous dopamine levels in retinas from chick embryos and post-hatched chicks. Endogenous dopamine was measured by enzyme-linked immunosorbent assay (ELISA). 5-MCA-NAT increased retinal endogenous dopamine levels at all developmental stages studied and in PH chicks (-logEC50=11.62±0.34 M). This effect was inhibited by non-selective antagonists of receptors and melatonin binding sites N-acetyl-2-benzyltryptamine (luzindole, 5 μM), but it was not inhibited by the Mel1b melatonin receptor antagonist 4-phenyl-2-propionamidotetralin (4-P-PDOT, 10 nM). The QR2 cosubstrate, N-methyl-dihydronicotinamide (NMH) (-logEC50=6.74±0.26 M), increased endogenous dopamine levels in controls and in retinas stimulated with 5-MCA-NAT (3 nM). The QR2 inhibitor benzo[e]pyrene inhibited endogenous dopamine levels in both control (-logIC50=7.4±0.28 M) and NMH-stimulated (at 100 nM and 1 μM benzo[e]pyrene concentrations) retinas. Theoretical studies using Molegro Virtual Docking software corroborated these experimental results. We conclude that 5-MCA-NAT increases the level of endogenous dopamine via QR2. We suggest that this enzyme triggers double reduction of the dopamine quinone, recovering dopamine in retinal development.
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Affiliation(s)
- Lucia de Fatima Sobral Sampaio
- Lab. de Bioquímica do Desenvolvimento do Sistema Nervoso, Instituto de Ciências Biológicas, Universidade Federal do Pará, Rua Augusto Corrêa No. 1, CEP: 66075-110 Belém, PA, Brazil.
| | - Felipe Pantoja Mesquita
- Lab. de Bioquímica do Desenvolvimento do Sistema Nervoso, Instituto de Ciências Biológicas, Universidade Federal do Pará, Rua Augusto Corrêa No. 1, CEP: 66075-110 Belém, PA, Brazil
| | - Paulo Robson Monteiro de Sousa
- Lab. de Planejamento e Desenvolvimento de Fármacos, Instituto de Ciências Exatas e Naturais, Universidade Federal do Pará, Rua Augusto Corrêa No. 1, CEP: 66075-110 Belém, PA, Brazil
| | - Jerônimo Lameira Silva
- Lab. de Planejamento e Desenvolvimento de Fármacos, Instituto de Ciências Exatas e Naturais, Universidade Federal do Pará, Rua Augusto Corrêa No. 1, CEP: 66075-110 Belém, PA, Brazil
| | - Claudio Nahum Alves
- Lab. de Planejamento e Desenvolvimento de Fármacos, Instituto de Ciências Exatas e Naturais, Universidade Federal do Pará, Rua Augusto Corrêa No. 1, CEP: 66075-110 Belém, PA, Brazil
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16
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Crooke A, Guzman-Aranguez A, Mediero A, Alarma-Estrany P, Carracedo G, Pelaez T, Peral A, Pintor J. Effect of melatonin and analogues on corneal wound healing: involvement of Mt2 melatonin receptor. Curr Eye Res 2014; 40:56-65. [PMID: 24892818 DOI: 10.3109/02713683.2014.914540] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
PURPOSE We have investigated the effect of melatonin and its analogues on rabbit corneal epithelial wound healing. METHODS New Zealand rabbits were anaesthetised and wounds were made by placing Whatman paper discs soaked in n-heptanol on the cornea. Melatonin and analogues (all 10 nmol) were instilled. Wound diameter was measured every 2 hours by means of fluorescein application with a Topcon SL-8Z slit lamp. Melatonin antagonists (all 10 nmol) were applied 2 hours before the application of the n-heptanol-soaked disc and then every 6 hours together with melatonin. To confirm the presence of MT2 receptors in corneal epithelial cells immunohistochemistry, Western blot and RT-PCR assays in native tissue and in rabbit corneal epithelial cells were performed. The tear components were extracted then processed by HPLC to quantify melatonin in tears. RESULTS Migration assays revealed that melatonin and particularly the treatment with the MT2 agonist IIK7, accelerated the rate of healing (p < 0.001). The application of the non-selective melatonin receptor antagonist luzindole and the MT2 antagonist DH97 (but not prazosin), prevented the effect of melatonin on wound healing (both p < 0.001). Immunohistochemistry, Western blot and RT-PCR assays showed the presence of MT2 melatonin receptor in corneal epithelial cells. In addition, we have identified melatonin in tears and determined its daily variations. CONCLUSIONS These data suggest that MT2 receptors are implicated in the effect of melatonin on corneal wound healing regulating migration rate. This suggests the potential use of melatonin and its analogues to enhance epithelial wound healing in ocular surface disease.
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Affiliation(s)
- Almudena Crooke
- Departamento de Bioquímica y Biología Molecular IV, Facultad de Óptica y Optometría, Universidad Complutense de Madrid , Madrid , Spain , and
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17
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Cruz MHC, Leal CLV, da Cruz JF, Tan DX, Reiter RJ. Role of melatonin on production and preservation of gametes and embryos: a brief review. Anim Reprod Sci 2014; 145:150-60. [PMID: 24559971 DOI: 10.1016/j.anireprosci.2014.01.011] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 01/15/2014] [Accepted: 01/20/2014] [Indexed: 12/16/2022]
Abstract
The aim of this brief review is to clarify the role of melatonin in the production and preservation of mammalian gametes and embryos. Melatonin is an indoleamine synthesized from tryptophan in the pineal gland and other organs that operates as a hypothalamic-pituitary-gonadal axis modulator and regulates the waxing and waning of seasonal reproductive competence in photoperiodic mammals. A major function of the melatonin rhythm is to transmit information about the length of the daily photoperiod to the circadian and circannual systems in order to provide time-of-day and time-of-year information, respectively, to the organism. Melatonin is also a powerful antioxidant and anti-apoptotic agent, which is due to its direct scavenging of toxic oxygen derivatives and its ability to reduce the formation of reactive species. Mammalian gametes and embryos are highly vulnerable to oxidative stress due to the presence of high lipid levels; during artificial breeding procedures, these structures are exposed to dramatic changes in the microenvironment, which have a direct bearing on their function and viability. Free radicals influence the balance between oxidation-reduction reactions, disturb the transbilayer-phospholipid asymmetry of the plasma membrane and enhance lipid peroxidation. Melatonin, due to its amphiphilic nature, is undoubtedly useful in tissues by protecting them from free radical-mediated oxidative damage and cellular death. The supplementation of melatonin to semen extender or culture medium significantly improves sperm viability, oocyte competence and blastocyst development in vitro.
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Affiliation(s)
- Maria Helena Coelho Cruz
- Department of Cellular and Structural Biology, UT Health Science Center at San Antonio, San Antonio, TX 78229, USA; Department of Veterinary Medicine, Faculty of Animal Science and Food Engineering, USP, 13635-900 Pirassununga SP, Brazil.
| | - Claudia Lima Verde Leal
- Department of Veterinary Medicine, Faculty of Animal Science and Food Engineering, USP, 13635-900 Pirassununga SP, Brazil
| | - Jurandir Ferreira da Cruz
- Department of Plant Science and Animal Science, Southwest Bahia State University, UESB, 45083-900 Vitória da Conquista BA, Brazil
| | - Dun-Xian Tan
- Department of Cellular and Structural Biology, UT Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Russel J Reiter
- Department of Cellular and Structural Biology, UT Health Science Center at San Antonio, San Antonio, TX 78229, USA
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A Drug Mystery of Heterocycles: Various Molecules for One Target or One Compound for Multiple Targets? Chem Heterocycl Compd (N Y) 2013. [DOI: 10.1007/s10593-013-1229-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Crooke A, Huete-Toral F, Martínez-Águila A, Martín-Gil A, Pintor J. Melatonin and its analog 5-methoxycarbonylamino-N-acetyltryptamine potentiate adrenergic receptor-mediated ocular hypotensive effects in rabbits: significance for combination therapy in glaucoma. J Pharmacol Exp Ther 2013; 346:138-45. [PMID: 23591996 DOI: 10.1124/jpet.112.202036] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Melatonin is currently considered a promising drug for glaucoma treatment because of its ocular hypotensive and neuroprotective effects. We have investigated the effect of melatonin and its analog 5-methoxycarbonylamino-N-acetyltryptamine, 5-MCA-NAT, on β₂/α(2A)-adrenergic receptor mRNA as well as protein expression in cultured rabbit nonpigmented ciliary epithelial cells. Quantitative polymerase chain reaction and immunocytochemical assays revealed a significant β₂-adrenergic receptor downregulation as well as α(2A)-adrenergic receptor up-regulation of treated cells (P < 0.001, maximal significant effect). In addition, we have studied the effect of these drugs upon the ocular hypotensive action of a nonselective β-adrenergic receptor (timolol) and a selective α₂-adrenergic receptor agonist (brimonidine) in normotensive rabbits. Intraocular pressure (IOP) experiments showed that the administration of timolol in rabbits pretreated with melatonin or 5-MCA-NAT evoked an additional IOP reduction of 14.02% ± 5.8% or 16.75% ± 5.48% (P < 0.01) in comparison with rabbits treated with timolol alone for 24 hours. Concerning brimonidine hypotensive action, an additional IOP reduction of 29.26% ± 5.21% or 39.07% ± 5.81% (P < 0.001) was observed in rabbits pretreated with melatonin or 5-MCA-NAT when compared with animals treated with brimonidine alone for 24 hours. Additionally, a sustained potentiating effect of a single dose of 5-MCA-NAT was seen in rabbits treated with brimonidine once daily for up 4 days (extra IOP decrease of 15.57% ± 5.15%, P < 0.05, compared with brimonidine alone). These data confirm the indirect action of melatoninergic compounds on adrenergic receptors and their remarkable effect upon the ocular hypotensive action mainly of α₂-adrenergic receptor agonists but also of β-adrenergic antagonists.
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Affiliation(s)
- Almudena Crooke
- Departamento de Bioquímica, Facultad de Óptica y Optometría, Universidad Complutense de Madrid, Madrid, Spain
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Huang H, Wang Z, Weng SJ, Sun XH, Yang XL. Neuromodulatory role of melatonin in retinal information processing. Prog Retin Eye Res 2013; 32:64-87. [PMID: 22986412 DOI: 10.1016/j.preteyeres.2012.07.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Revised: 07/24/2012] [Accepted: 07/25/2012] [Indexed: 12/15/2022]
Affiliation(s)
- Hai Huang
- Institute of Neurobiology, Institutes of Brain Science, Fudan University, Shanghai, PR China
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Crooke A, Huete-Toral F, Martínez-Águila A, Colligris B, Pintor J. Ocular disorders and the utility of animal models in the discovery of melatoninergic drugs with therapeutic potential. Expert Opin Drug Discov 2012; 7:989-1001. [PMID: 22860991 DOI: 10.1517/17460441.2012.714769] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
INTRODUCTION The pineal indole-derived hormone melatonin is a modulator of circadian and seasonal rhythms with an important role in ocular health and disease. This could be due to specific melatonin receptors that have been identified in structures such as cornea, lens, ciliary body, retina, choroid and sclera. In addition, a local synthesis of melatonin occurs in several of these ocular tissues. AREAS COVERED The authors review existing literature on the most common animal models where ocular melatonin actions have been tested. The therapeutic potential of melatonin in diabetic keratopathy and retinopathy, keratitis, cataracts, glaucoma, uveitis, age-related macular degeneration and retinitis pigmentosa is discussed. Furthermore, the authors comment on the usefulness of different animal models for the development of melatoninergic drugs with therapeutic potential. EXPERT OPINION The use of animals for the study of ocular diseases and the potentiality of melatonin and its analogs, as future therapeutic drugs, should be performed on the basis of a rationale study. It is important to note that melatonin receptors seem to be widespread all over the eye. This strongly suggests that, in order to modify the physiology and biochemistry of malfunctioning ocular tissue, the melatonin receptors which are present in that tissue must be first identified. Second there is the need to confirm that those receptors targeted perform the desirable responses, and as a third measure, to use selective agonists (or antagonists) instead of melatonin. However, although some animals mimic ocular pathologies relatively well, and these can be used in melatonin studies, there is still a long way to go till some of the results obtained in animal models could be used for human therapy.
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Affiliation(s)
- Almudena Crooke
- Departamento de Bioquímica y Biología Molecular IV, E.U. Óptica, Universidad Complutense de Madrid, C/Arcos de Jalón 118, Madrid, Spain
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Slominski RM, Reiter RJ, Schlabritz-Loutsevitch N, Ostrom RS, Slominski AT. Melatonin membrane receptors in peripheral tissues: distribution and functions. Mol Cell Endocrinol 2012; 351:152-66. [PMID: 22245784 PMCID: PMC3288509 DOI: 10.1016/j.mce.2012.01.004] [Citation(s) in RCA: 468] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Accepted: 01/01/2012] [Indexed: 12/15/2022]
Abstract
Many of melatonin's actions are mediated through interaction with the G-protein coupled membrane bound melatonin receptors type 1 and type 2 (MT1 and MT2, respectively) or, indirectly with nuclear orphan receptors from the RORα/RZR family. Melatonin also binds to the quinone reductase II enzyme, previously defined the MT3 receptor. Melatonin receptors are widely distributed in the body; herein we summarize their expression and actions in non-neural tissues. Several controversies still exist regarding, for example, whether melatonin binds the RORα/RZR family. Studies of the peripheral distribution of melatonin receptors are important since they are attractive targets for immunomodulation, regulation of endocrine, reproductive and cardiovascular functions, modulation of skin pigmentation, hair growth, cancerogenesis, and aging. Melatonin receptor agonists and antagonists have an exciting future since they could define multiple mechanisms by which melatonin modulates the complexity of such a wide variety of physiological and pathological processes.
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Affiliation(s)
- Radomir M. Slominski
- Department of Pharmacology, University of Tennessee Health Science Center, Memphis, TN 38163, United States
- Department of Pathology and Laboratory Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, United States
| | - Russel J. Reiter
- Department of Cellular & Structural Biology, UT Health Science Center, San Antonio, TX 78229-3900, United States
| | - Natalia Schlabritz-Loutsevitch
- Department of Obstetrics and Gynecology, University of Tennessee Health Science Center, Memphis, TN 38163, United States
| | - Rennolds S. Ostrom
- Department of Pharmacology, University of Tennessee Health Science Center, Memphis, TN 38163, United States
| | - Andrzej T. Slominski
- Department of Pathology and Laboratory Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, United States
- Division of Dermatology, Department of Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, United States
- Corresponding author at: Department of Pathology and Laboratory Medicine, University of Tennessee Health Science Center, 930 Madison Avenue, Suite 5000, Memphis, TN 38163, United States. Tel.: +1 901 448 3741. (A.T. Slominski)
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Crooke A, Huete-Toral F, Martínez-Águila A, Martín-Gil A, Pintor J. Involvement of carbonic anhydrases in the ocular hypotensive effect of melatonin analogue 5-MCA-NAT. J Pineal Res 2012; 52:265-70. [PMID: 22107075 DOI: 10.1111/j.1600-079x.2011.00938.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We have previously demonstrated that melatonin and its analogue, 5-methoxycarbonylamino-N-acetyltryptamine (5-MCA-NAT), reduce intraocular pressure (IOP) in New Zealand rabbits. More recently, we have shown that 5-MCA-NAT can also regulate ciliary adrenoceptor gene expression. Like adrenoceptors, carbonic anhydrase (CA) enzymes are involved in aqueous humour secretion by the ocular ciliary epithelium. Moreover, CA enzymes have been reported to be regulated by melatonin. Hence, the aim of this study was to investigate whether the hypotensive effect of 5-MCA-NAT is also because of a regulation of CA genes and enzymes. Time course of 5-MCA-NAT effect on rabbit IOP was followed for 7 hr every day for up to 144 hr (6 days). 5-MCA-NAT reduced IOP, maximally by 51.30 ± 2.41% (at 3 hr), and the hypotensive effect was maintained for up to 96 hr with a single application. IOP studies with 5-MCA-NAT plus Trusopt(®) and immunohistochemical analysis confirmed that CA are molecular targets of 5-MCA-NAT. In addition, real-time quantitative PCR (qPCR) and immunocytochemical assays were performed to determine changes in CA2 (CAII) and CA12 (CAXII) expression in cultured rabbit nonpigmented ciliary epithelial cells (NPE) treated with 5-MCA-NAT. NPE cells showed a prominent decrease in both CA, at the mRNA and protein levels. These data confirm that the long-term hypotensive effect of 5-MCA-NAT is also due, to a down-regulation of CA2 (CAII) and CA12 (CAXII) expression.
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Affiliation(s)
- Almudena Crooke
- Departamento de Bioquímica, E.U. Óptica, Universidad Complutense de Madrid, Madrid, Spain
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Regulation of ocular adrenoceptor genes expression by 5-MCA-NAT: implications for glaucoma treatment. Pharmacogenet Genomics 2011; 21:587-9. [PMID: 21705965 DOI: 10.1097/fpc.0b013e32834910d1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We have demonstrated that 5-methoxycarbonylamino-N-acetyltryptamine (5-MCA-NAT), reduces intraocular pressure (IOP) in rabbits. In addition, we have reported a link between hypotensive effect of 5-MCA-NAT and sympathetic nervous system. Moreover, it is known that aqueous humour production is controlled by the activation of adrenoceptors (ADRs) present in the ocular ciliary epithelium. Thus, the aim of this study is to investigate if the hypotensive effect of 5-MCA-NAT is due to a regulation of ciliary ADR genes expression. To confirm this we followed the effect of 5-MCA-NAT on rabbit IOP for 144 consecutive hours. A sustained IOP reduction for up to 72 h (P<0.01) was seen. In addition, changes in ADRB2 and ADRA2A mRNA were measured in cultured rabbit nonpigmented ciliary epithelial cells. After 5-MCA-NAT treatment, a significant downregulation of ADRB2 and upregulation of ADRA2A was observed. These results provide the regulation of ADRs mRNA by 5-MCA-NAT.
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Alcantara-Contreras S, Baba K, Tosini G. Removal of melatonin receptor type 1 increases intraocular pressure and retinal ganglion cells death in the mouse. Neurosci Lett 2011; 494:61-4. [PMID: 21362461 DOI: 10.1016/j.neulet.2011.02.056] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2010] [Revised: 01/19/2011] [Accepted: 02/22/2011] [Indexed: 11/18/2022]
Abstract
Previous studies have demonstrated that melatonin is effective in lowering intraocular pressure and that it may also protect ganglion cells. We have recently reported that, in mice lacking the melatonin receptors type 1, 25-30% ganglion cells die out by 18months of age, suggesting that these receptors might be important for ganglion cells survival. In this study we show that the loss of ganglion cells is specific for melatonin receptors type 1 knock-out since mice lacking the melatonin receptors type 2 did not show any significant change in the number ganglion cells during aging. Furthermore, we report that melatonin receptors type 1 knock-out mice have higher intraocular pressure during the nocturnal hours than control or melatonin receptors type 2 knock-out mice at 3 and 12months of age. Finally, our data indicate that administration of exogenous melatonin in wild-type, but not in melatonin receptors type 1 knock-out, can significantly reduce intraocular pressure. Our studies indicate that the decreased viability of ganglion cells observed in melatonin receptors type 1 knock-out mice may be a consequence of the increases in the nocturnal intraocular pressure thus suggesting that intraocular pressure levels at night and melatonin signaling should be considered as risk factor in the pathogenesis of glaucoma.
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Affiliation(s)
- Susana Alcantara-Contreras
- Circadian Rhythms and Sleep Disorders Program, Neuroscience Institute and Department of Pharmacology & Toxicology, Morehouse School of Medicine, 720 Westview Dr. SW, Atlanta, GA 30130, United States
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Ferry G, Hecht S, Berger S, Moulharat N, Coge F, Guillaumet G, Leclerc V, Yous S, Delagrange P, Boutin JA. Old and new inhibitors of quinone reductase 2. Chem Biol Interact 2010; 186:103-9. [PMID: 20399199 DOI: 10.1016/j.cbi.2010.04.006] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2010] [Revised: 04/02/2010] [Accepted: 04/07/2010] [Indexed: 10/19/2022]
Abstract
Quinone reductase 2 is a cytosolic enzyme which catalyses the reduction of quinones, such as menadione and coenzymes Q. Despite a relatively close sequence-based resemblance to NAD(P)H:quinone oxidoreductase 1 (QR1), it has many different features. QR2 is the third melatonin binding site (MT3). It is inhibited in the micromolar range by melatonin, and does not accept conventional phosphorylated nicotinamides as hydride donors. QR2 has a powerful capacity to activate quinones leading to unexpected toxicity situations. In the present paper, we report the characterization of three QR2 modulators: melatonin, resveratrol and S29434. The latter compound inhibits QR2 activity with an IC(50) in the low nanomolar range. The potency of the modulators ranged as follows, from the least to the most potent: melatonin<resveratrol<S29434. These molecular tools might permit to explore and better understand the relationship existing between QR2 catalytic activity and the various pathological situations in which QR2 has a key role.
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Affiliation(s)
- Gilles Ferry
- Pharmacologie Moléculaire et Cellulaire, Institut de Recherches Servier, 125, Chemin de Ronde, 78290 Croissy sur Seine, France
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