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Tse LH, Cheung ST, Lee S, Wong YH. Real-Time Determination of Intracellular cAMP Reveals Functional Coupling of G s Protein to the Melatonin MT 1 Receptor. Int J Mol Sci 2024; 25:2919. [PMID: 38474167 DOI: 10.3390/ijms25052919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 02/23/2024] [Accepted: 02/28/2024] [Indexed: 03/14/2024] Open
Abstract
Melatonin is a neuroendocrine hormone that regulates the circadian rhythm and many other physiological processes. Its functions are primarily exerted through two subtypes of human melatonin receptors, termed melatonin type-1 (MT1) and type-2 (MT2) receptors. Both MT1 and MT2 receptors are generally classified as Gi-coupled receptors owing to their well-recognized ability to inhibit cAMP accumulation in cells. However, it remains an enigma as to why melatonin stimulates cAMP production in a number of cell types that express the MT1 receptor. To address if MT1 can dually couple to Gs and Gi proteins, we employed a highly sensitive luminescent biosensor (GloSensorTM) to monitor the real-time changes in the intracellular cAMP level in intact live HEK293 cells that express MT1 and/or MT2. Our results demonstrate that the activation of MT1, but not MT2, leads to a robust enhancement on the forskolin-stimulated cAMP formation. In contrast, the activation of either MT1 or MT2 inhibited cAMP synthesis driven by the activation of the Gs-coupled β2-adrenergic receptor, which is consistent with a typical Gi-mediated response. The co-expression of MT1 with Gs enabled melatonin itself to stimulate cAMP production, indicating a productive coupling between MT1 and Gs. The possible existence of a MT1-Gs complex was supported through molecular modeling as the predicted complex exhibited structural and thermodynamic characteristics that are comparable to that of MT1-Gi. Taken together, our data reveal that MT1, but not MT2, can dually couple to Gs and Gi proteins, thereby enabling the bi-directional regulation of adenylyl cyclase to differentially modulate cAMP levels in cells that express different complements of MT1, MT2, and G proteins.
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Affiliation(s)
- Lap Hang Tse
- Division of Life Science and the Biotechnology Research Institute, Hong Kong University of Science and Technology, Hong Kong, China
| | - Suet Ting Cheung
- Division of Life Science and the Biotechnology Research Institute, Hong Kong University of Science and Technology, Hong Kong, China
| | - Seayoung Lee
- Division of Life Science and the Biotechnology Research Institute, Hong Kong University of Science and Technology, Hong Kong, China
| | - Yung Hou Wong
- Division of Life Science and the Biotechnology Research Institute, Hong Kong University of Science and Technology, Hong Kong, China
- State Key Laboratory of Molecular Neuroscience, Molecular Neuroscience Center, Hong Kong University of Science and Technology, Hong Kong, China
- Hong Kong Center for Neurodegenerative Diseases, 17 Science Park West Avenue, Hong Kong Science Park, Shatin, Hong Kong, China
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2
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Zhang W, Zhao W, Li Q, Zhao D, Qu J, Yuan Z, Cheng Z, Zhu X, Zhuang X, Zhang Z. 3D-printing magnesium-polycaprolactone loaded with melatonin inhibits the development of osteosarcoma by regulating cell-in-cell structures. J Nanobiotechnology 2021; 19:263. [PMID: 34481503 PMCID: PMC8418751 DOI: 10.1186/s12951-021-01012-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 08/24/2021] [Indexed: 12/30/2022] Open
Abstract
Melatonin has been proposed as a potent anticarcinogen presents a short half-life for osteosarcoma (OS). Cell-in-cell (CIC) structures play a role in the development of malignant tumors by changing the tumor cell energy metabolism. This study developed a melatonin-loaded 3D printed magnesium-polycaprolactone (Mg-PCL) scaffold and investigated its effect and molecular mechanism on CIC in OS. Mg-PCL scaffold was prepared by 3D-printing and its characteristic was determined. The effect and molecular mechanism of Mg-PCL scaffold as well as melatonin-loaded Mg-PCL on OS growth and progression were investigated in vivo and in vitro. We found that melatonin receptor 1 (MT1) and CIC expressions were increased in OS tissues and cells. Melatonin treatment inhibit the key CIC pathway, Rho/ROCK, through the cAMP/PKA signaling pathway, interfering with the mitochondrial physiology of OS cells, and thus playing an anti-invasion and anti-metastasis role in OS. The Mg-PCL-MT could significantly inhibit distant organ metastasis of OS in the in vivo model. Our results showed that melatonin-loaded Mg-PCL scaffolds inhibited the proliferation, invasion and metastasis of OS cells through the CIC pathway. The Mg-PCL-MT could be a potential therapeutics for OS.
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Affiliation(s)
- Weilin Zhang
- Department of Orthopedics, The Fourth Affiliated Hospital of China Medical University, Shenyang, 110032, Liaoning, China
| | - Wei Zhao
- Department of Orthopedics, The Fourth Affiliated Hospital of China Medical University, Shenyang, 110032, Liaoning, China
| | - Qin Li
- Translational Medicine Center, The Fourth Affiliated Hospital of China Medical University, Shenyang, Liaoning, China
| | - Duoyi Zhao
- Department of Orthopedics, The Fourth Affiliated Hospital of China Medical University, Shenyang, 110032, Liaoning, China
| | - Junxing Qu
- Department of Orthopedics, The Fourth Affiliated Hospital of China Medical University, Shenyang, 110032, Liaoning, China
| | - Ziyang Yuan
- Department of Orthopedics, The Fourth Affiliated Hospital of China Medical University, Shenyang, 110032, Liaoning, China
| | - Zhihong Cheng
- Department of Orthopedics, The Fourth Affiliated Hospital of China Medical University, Shenyang, 110032, Liaoning, China
| | - Xiaojuan Zhu
- Key Laboratory of Molecular Epigenetics, Ministry of Education and Institute of Cytology and Genetics, Northeast Normal University, Changchun, Jilin, China
| | - Xiuli Zhuang
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry Chinese Academy of Sciences, Changchun, Jilin, China
| | - Zhiyu Zhang
- Department of Orthopedics, The Fourth Affiliated Hospital of China Medical University, Shenyang, 110032, Liaoning, China.
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New insights into antimetastatic signaling pathways of melatonin in skeletomuscular sarcoma of childhood and adolescence. Cancer Metastasis Rev 2020; 39:303-320. [PMID: 32086631 DOI: 10.1007/s10555-020-09845-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Melatonin is an indole produced by the pineal gland at night under normal light or dark conditions, and its levels, which are higher in children than in adults, begin to decrease prior to the onset of puberty and continue to decline thereafter. Apart from circadian regulatory actions, melatonin has significant apoptotic, angiogenic, oncostatic, and antiproliferative effects on various cancer cells. Particularly, the ability of melatonin to inhibit skeletomuscular sarcoma, which most commonly affects children, teenagers, and young adults, is substantial. In the past few decades, the vast majority of references have focused on the concept of epithelial-mesenchymal transition involvement in invasion and migration to allow carcinoma cells to dissociate from each other and to degrade the extracellular matrix. Recently, researchers have applied this idea to sarcoma cells of mesenchymal origin, e.g., osteosarcoma and Ewing sarcoma, with their ability to initiate the invasion-metastasis cascade. Similarly, interest of the effects of melatonin has shifted from carcinomas to sarcomas. Herein, in this state-of-the-art review, we compiled the knowledge related to the molecular mechanism of antimetastatic actions of melatonin on skeletomuscular sarcoma as in childhood and during adolescence. Utilization of melatonin as an adjuvant with chemotherapeutic drugs for synergy and fortification of the antimetastatic effects for the reinforcement of therapeutic actions are considered.
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4
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Ciani E, Fontaine R, Maugars G, Mizrahi N, Mayer I, Levavi-Sivan B, Weltzien FA. Melatonin receptors in Atlantic salmon stimulate cAMP levels in heterologous cell lines and show season-dependent daily variations in pituitary expression levels. J Pineal Res 2019; 67:e12590. [PMID: 31169933 DOI: 10.1111/jpi.12590] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 05/07/2019] [Accepted: 05/26/2019] [Indexed: 01/13/2023]
Abstract
The hormone melatonin connects environmental cues, such as photoperiod and temperature, with a number of physiological and behavioural processes, including seasonal reproduction, through binding to their cognate receptors. This study reports the structural, functional and physiological characterization of five high-affinity melatonin receptors (Mtnr1aaα, Mtnr1aaβ, Mtnr1ab, Mtnr1al, Mtnr1b) in Atlantic salmon. Phylogenetic analysis clustered salmon melatonin receptors into three monophyletic groups, Mtnr1A, Mtnr1Al and Mtnr1B, but no functional representative of the Mtnr1C group. Contrary to previous studies in vertebrates, pharmacological characterization of four receptors in COS-7, CHO and SH-SY5Y cell lines (Mtnr1Aaα, Mtnr1Aaβ, Mtnr1Ab, Mtnr1B) showed induction of intracellular cAMP levels following 2-iodomelatonin or melatonin exposure. No consistent response was measured after N-acetyl-serotonin or serotonin exposure. Melatonin receptor genes were expressed at all levels of the hypothalamo-pituitary-gonad axis, with three genes (mtnr1aaβ, mtnr1ab and mtnr1b) detected in the pituitary. Pituitary receptors displayed daily fluctuations in mRNA levels during spring, prior to the onset of gonadal maturation, but not in autumn, strongly implying a direct involvement of melatonin in seasonal processes regulated by the pituitary. To the best of our knowledge, this is the first report of cAMP induction mediated via melatonin receptors in a teleost species.
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Affiliation(s)
- Elia Ciani
- Department of Basic Sciences and Aquatic Medicine, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | - Romain Fontaine
- Department of Basic Sciences and Aquatic Medicine, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | - Gersende Maugars
- Department of Basic Sciences and Aquatic Medicine, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | - Naama Mizrahi
- Department of Animal Sciences, Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Ian Mayer
- Department of Production Animal Clinical Sciences, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | - Berta Levavi-Sivan
- Department of Animal Sciences, Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Finn-Arne Weltzien
- Department of Basic Sciences and Aquatic Medicine, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
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Cardinali DP. Melatonin: Clinical Perspectives in Neurodegeneration. Front Endocrinol (Lausanne) 2019; 10:480. [PMID: 31379746 PMCID: PMC6646522 DOI: 10.3389/fendo.2019.00480] [Citation(s) in RCA: 106] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 07/03/2019] [Indexed: 12/20/2022] Open
Abstract
Prevention of neurodegenerative diseases is presently a major goal for our Society and melatonin, an unusual phylogenetically conserved molecule present in all aerobic organisms, merits consideration in this respect. Melatonin combines both chronobiotic and cytoprotective properties. As a chronobiotic, melatonin can modify phase and amplitude of biological rhythms. As a cytoprotective molecule, melatonin reverses the low degree inflammatory damage seen in neurodegenerative disorders and aging. Low levels of melatonin in blood characterizes advancing age. In experimental models of Alzheimer's disease (AD) and Parkinson's disease (PD) the neurodegeneration observed is prevented by melatonin. Melatonin also increased removal of toxic proteins by the brain glymphatic system. A limited number of clinical trials endorse melatonin's potentiality in AD and PD, particularly at an early stage of disease. Calculations derived from animal studies indicate cytoprotective melatonin doses in the 40-100 mg/day range. Hence, controlled studies employing melatonin doses in this range are urgently needed. The off-label use of melatonin is discussed.
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Krestinina OV, Baburina YL, Odinokova IV, Azarashvili TS, Akatov VS. Melatonin Modulates Phosphorylation of 2′,3′-Cyclic Nucleotide-3′-Phosphodiesterase in the Presence of Protoporphyrin IX in the Brain Mitochondria of Rats during the Functioning of the Non-Specific Mitochondrial Pore. NEUROCHEM J+ 2018. [DOI: 10.1134/s1819712418010051] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Melatonin promotes triacylglycerol accumulation via MT2 receptor during differentiation in bovine intramuscular preadipocytes. Sci Rep 2017; 7:15080. [PMID: 29118419 PMCID: PMC5678110 DOI: 10.1038/s41598-017-12780-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Accepted: 09/14/2017] [Indexed: 12/22/2022] Open
Abstract
Melatonin (N-acetyl-5-methoxytryptamine) is a derivative of tryptophan which is produced and secreted mainly by the pineal gland and regulates a variety of important central and peripheral actions. To examine the potential effects of melatonin on the proliferation and differentiation of bovine intramuscular preadipocytes (BIPs), BIPs were incubated with different concentrations of melatonin. Melatonin supplementation at 1 mM significantly increased peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer-binding protein (C/EBP) β, and C/EBPα expression and promoted the differentiation of BIPs into adipocytes with large lipid droplets and high cellular triacylglycerol (TAG) levels. Melatonin also significantly enhanced lipolysis and up-regulated the expression of lipolytic genes and proteins, including hormone sensitive lipase (HSL), adipocyte triglyceride lipase (ATGL), and perilipin 1 (PLIN1). Moreover, melatonin reduced intracellular reactive oxygen species (ROS) levels by increasing the expression levels and activities of superoxide dismutase 1 (SOD1) and glutathione peroxidase 4 (GPX4). Finally, the positive effects of melatonin on adipogenesis, lipolysis, and redox status were reversed by treatment with luzindole, anantagonist of nonspecific melatonin receptors 1 (MT1) and 2 (MT2), and 4-phenyl-2-propionamidotetraline (4P-PDOT), a selective MT2 antagonist. These results reveal that melatonin promotes TAG accumulation via MT2 receptor during differentiation in BIPs.
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Shukla M, Govitrapong P, Boontem P, Reiter RJ, Satayavivad J. Mechanisms of Melatonin in Alleviating Alzheimer's Disease. Curr Neuropharmacol 2017; 15:1010-1031. [PMID: 28294066 PMCID: PMC5652010 DOI: 10.2174/1570159x15666170313123454] [Citation(s) in RCA: 113] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 02/10/2017] [Accepted: 03/09/2017] [Indexed: 02/07/2023] Open
Abstract
Alzheimer's disease (AD) is a chronic, progressive and prevalent neurodegenerative disease characterized by the loss of higher cognitive functions and an associated loss of memory. The thus far "incurable" stigma for AD prevails because of variations in the success rates of different treatment protocols in animal and human studies. Among the classical hypotheses explaining AD pathogenesis, the amyloid hypothesis is currently being targeted for drug development. The underlying concept is to prevent the formation of these neurotoxic peptides which play a central role in AD pathology and trigger a multispectral cascade of neurodegenerative processes post-aggregation. This could possibly be achieved by pharmacological inhibition of β- or γ-secretase or stimulating the nonamyloidogenic α-secretase. Melatonin the pineal hormone is a multifunctioning indoleamine. Production of this amphiphilic molecule diminishes with advancing age and this decrease runs parallel with the progression of AD which itself explains the potential benefits of melatonin in line of development and devastating consequences of the disease progression. Our recent studies have revealed a novel mechanism by which melatonin stimulates the nonamyloidogenic processing and inhibits the amyloidogenic processing of β-amyloid precursor protein (βAPP) by stimulating α -secretases and consequently down regulating both β- and γ-secretases at the transcriptional level. In this review, we discuss and evaluate the neuroprotective functions of melatonin in AD pathogenesis, including its role in the classical hypotheses in cellular and animal models and clinical interventions in AD patients, and suggest that with early detection, melatonin treatment is qualified to be an anti-AD therapy.
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Affiliation(s)
- Mayuri Shukla
- Chulabhorn Graduate Institute, Chulabhorn Royal Academy, 54 Kamphaeng Phet 6 Road, Lak Si, Bangkok10210, Thailand
| | - Piyarat Govitrapong
- Chulabhorn Graduate Institute, Chulabhorn Royal Academy, 54 Kamphaeng Phet 6 Road, Lak Si, Bangkok10210, Thailand
- Research Center for Neuroscience, Institute of Molecular Biosciences, Mahidol University, Salaya, Nakornpathom 73170, Thailand
| | - Parichart Boontem
- Chulabhorn Graduate Institute, Chulabhorn Royal Academy, 54 Kamphaeng Phet 6 Road, Lak Si, Bangkok10210, Thailand
| | - Russel J. Reiter
- Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Jutamaad Satayavivad
- Chulabhorn Research Institute and Chulabhorn Graduate Institute, Chulabhorn Royal Academy, Bangkok10210, Thailand
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Deng SL, Chen SR, Wang ZP, Zhang Y, Tang JX, Li J, Wang XX, Cheng JM, Jin C, Li XY, Zhang BL, Yu K, Lian ZX, Liu GS, Liu YX. Melatonin promotes development of haploid germ cells from early developing spermatogenic cells of Suffolk sheep under in vitro condition. J Pineal Res 2016; 60:435-47. [PMID: 26993286 DOI: 10.1111/jpi.12327] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 03/15/2016] [Indexed: 01/03/2023]
Abstract
Promotion of spermatogonial stem cell (SSC) differentiation into functional sperms under in vitro conditions is a great challenge for reproductive physiologists. In this study, we observed that melatonin (10(-7) M) supplementation significantly enhanced the cultured SSCs differentiation into haploid germ cells. This was confirmed by the expression of sperm special protein, acrosin. The rate of SSCs differentiation into sperm with melatonin supplementation was 11.85 ± 0.93% which was twofold higher than that in the control. The level of testosterone, the transcriptions of luteinizing hormone receptor (LHR), and the steroidogenic acute regulatory protein (StAR) were upregulated with melatonin treatment. At the early stage of SSCs culture, melatonin suppressed the level of cAMP, while at the later stage, it promoted cAMP production. The similar pattern was observed in testosterone content. Expressions for marker genes of meiosis anaphase, Dnmt3a, and Bcl-2 were upregulated by melatonin. In contrast, Bax expression was downregulated. Importantly, the in vitro-generated sperms were functional and they were capable to fertilize oocytes. These fertilized oocytes have successfully developed to the blastula stage.
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Affiliation(s)
- Shou-Long Deng
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Su-Ren Chen
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Zhi-Peng Wang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Yan Zhang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Ji-Xin Tang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Jian Li
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Xiu-Xia Wang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Jin-Mei Cheng
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Cheng Jin
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Xiao-Yu Li
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Bao-Lu Zhang
- National key Lab of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, P.R. China
| | - Kun Yu
- National key Lab of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, P.R. China
| | - Zheng-Xing Lian
- Laboratory of Animal Genetics and Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, P.R. China
| | - Guo-Shi Liu
- Laboratory of Animal Genetics and Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, P.R. China
| | - Yi-Xun Liu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
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Stefanova NA, Maksimova KY, Kiseleva E, Rudnitskaya EA, Muraleva NA, Kolosova NG. Melatonin attenuates impairments of structural hippocampal neuroplasticity in OXYS rats during active progression of Alzheimer's disease-like pathology. J Pineal Res 2015; 59:163-77. [PMID: 25988948 DOI: 10.1111/jpi.12248] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 05/08/2015] [Indexed: 12/17/2022]
Abstract
Translational research on Alzheimer's disease (AD) has often focused on reducing the high cerebral levels of amyloid-β (Aβ) as a key characteristic of AD pathogenesis. There is, however, a growing body of evidence that synaptic dysfunction may be crucial for the development of the most common (sporadic) form of AD. The applicability of melatonin (mainly produced by the pineal gland) to the treatment of AD is actively evaluated, but usually, such studies are based on animal models of early-onset AD, which is responsible for only ~5% of AD cases. We have shown previously that in OXYS rats (an established model of sporadic AD), accumulation of toxic forms of Aβ in the brain occurs later than does the development of signs of neurodegenerative changes and synaptic failure. In this regard, recently, we uncovered beneficial neuroprotective effects of melatonin (prophylactic dietary supplementation) in OXYS rats. Our aim here was to evaluate, starting at the age of active progression of AD-like pathology in OXYS rats, the effects of long-term oral administration of melatonin on the structure of synapses and on neuronal and glial cells of the hippocampus. Melatonin significantly increased hippocampal synaptic density and the number of excitatory synapses, decreased the number of inhibitory synapses, and upregulated pre- and postsynaptic proteins (synapsin I and PSD-95, respectively). Furthermore, melatonin improved the ultrastructure of neuronal and glial cells and reduced glial density. Based on our past and present results, the repair of neuroplasticity by melatonin is a promising strategy against AD.
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Affiliation(s)
| | | | | | | | | | - Nataliya G Kolosova
- Institute of Cytology and Genetics, Novosibirsk, Russia
- Novosibirsk State University, Novosibirsk, Russia
- Institute of Mitoengineering, Moscow, Russia
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Hill SM, Belancio VP, Dauchy RT, Xiang S, Brimer S, Mao L, Hauch A, Lundberg PW, Summers W, Yuan L, Frasch T, Blask DE. Melatonin: an inhibitor of breast cancer. Endocr Relat Cancer 2015; 22:R183-204. [PMID: 25876649 PMCID: PMC4457700 DOI: 10.1530/erc-15-0030] [Citation(s) in RCA: 204] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/14/2015] [Indexed: 12/19/2022]
Abstract
The present review discusses recent work on melatonin-mediated circadian regulation, the metabolic and molecular signaling mechanisms that are involved in human breast cancer growth, and the associated consequences of circadian disruption by exposure to light at night (LEN). The anti-cancer actions of the circadian melatonin signal in human breast cancer cell lines and xenografts heavily involve MT1 receptor-mediated mechanisms. In estrogen receptor alpha (ERα)-positive human breast cancer, melatonin suppresses ERα mRNA expression and ERα transcriptional activity via the MT1 receptor. Melatonin also regulates the transactivation of other members of the nuclear receptor superfamily, estrogen-metabolizing enzymes, and the expression of core clock and clock-related genes. Furthermore, melatonin also suppresses tumor aerobic metabolism (the Warburg effect) and, subsequently, cell-signaling pathways critical to cell proliferation, cell survival, metastasis, and drug resistance. Melatonin demonstrates both cytostatic and cytotoxic activity in breast cancer cells that appears to be cell type-specific. Melatonin also possesses anti-invasive/anti-metastatic actions that involve multiple pathways, including inhibition of p38 MAPK and repression of epithelial-mesenchymal transition (EMT). Studies have demonstrated that melatonin promotes genomic stability by inhibiting the expression of LINE-1 retrotransposons. Finally, research in animal and human models has indicated that LEN-induced disruption of the circadian nocturnal melatonin signal promotes the growth, metabolism, and signaling of human breast cancer and drives breast tumors to endocrine and chemotherapeutic resistance. These data provide the strongest understanding and support of the mechanisms that underpin the epidemiologic demonstration of elevated breast cancer risk in night-shift workers and other individuals who are increasingly exposed to LEN.
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Affiliation(s)
- Steven M Hill
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
| | - Victoria P Belancio
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
| | - Robert T Dauchy
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
| | - Shulin Xiang
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
| | - Samantha Brimer
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
| | - Lulu Mao
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
| | - Adam Hauch
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
| | - Peter W Lundberg
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
| | - Whitney Summers
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
| | - Lin Yuan
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
| | - Tripp Frasch
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
| | - David E Blask
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
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12
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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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13
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Chen L, He X, Zhang Y, Chen X, Lai X, Shao J, Shi Y, Zhou N. Melatonin receptor type 1 signals to extracellular signal-regulated kinase 1 and 2 via Gi and Gs dually coupled pathways in HEK-293 cells. Biochemistry 2014; 53:2827-39. [PMID: 24724723 DOI: 10.1021/bi500092e] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The pineal gland hormone melatonin exerts its regulatory roles in a variety of physiological and pathological responses through two G protein-coupled receptors, melatonin receptor type 1 (MT1) and melatonin receptor type 2 (MT2), which have been recognized as promising targets in the treatment of a number of human diseases and disorders. The MT1 receptor was identified nearly 20 years ago; however, the molecular mechanisms by which MT1-mediated signaling affects physiology remain to be further elucidated. In this study, using HEK293 cells stably expressing the human MT1 receptor, melatonin induced a concentration-dependent activation of extracellular signal-regulated kinase 1 and 2 (ERK1/2). The melatonin-mediated phosphorylation of ERK1/2 at later time points (≥5 min) was strongly suppressed by pretreatment with pertussis toxin, but only a slight, if any, inhibition of ERK1/2 activation at early time points (≤2 min) was detected. Further experiments demonstrated that the Gβγ subunit, phosphoinositide 3-kinase, and calcium-insensitive protein kinase C were involved in the MT1-mediated activation of ERK1/2 at later time points (≥5 min). Moreover, results derived from cAMP assays combined with a MT1 mutant indicated that the human MT1 receptor could also couple to Gs protein, stimulating intracellular cAMP formation, and that the MT1-induced activation of ERK1/2 at early time points (≤2 min) was mediated by the Gs/cAMP/PKA cascade. Our findings may provide new insights into the pharmacological effects and physiological functions modulated by the MT1-mediated activation of ERK1/2.
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Affiliation(s)
- Linjie Chen
- Institute of Biochemistry, College of Life Sciences, Zhejiang University , Hangzhou, Zhejiang 310058, China
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14
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Cardinali DP, Vigo DE, Olivar N, Vidal MF, Brusco LI. Melatonin Therapy in Patients with Alzheimer's Disease. Antioxidants (Basel) 2014; 3:245-77. [PMID: 26784870 PMCID: PMC4665493 DOI: 10.3390/antiox3020245] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2014] [Revised: 03/09/2014] [Accepted: 03/17/2014] [Indexed: 12/20/2022] Open
Abstract
Alzheimer's disease (AD) is a major health problem and a growing recognition exists that efforts to prevent it must be undertaken by both governmental and non-governmental organizations. In this context, the pineal product, melatonin, has a promising significance because of its chronobiotic/cytoprotective properties potentially useful for a number of aspects of AD. One of the features of advancing age is the gradual decrease in circulating melatonin levels. A limited number of therapeutic trials have indicated that melatonin has a therapeutic value as a neuroprotective drug in the treatment of AD and minimal cognitive impairment (which may evolve to AD). Both in vitro and in vivo, melatonin prevented the neurodegeneration seen in experimental models of AD. For these effects to occur, doses of melatonin about two orders of magnitude higher than those required to affect sleep and circadian rhythmicity are needed. More recently, attention has been focused on the development of potent melatonin analogs with prolonged effects, which were employed in clinical trials in sleep-disturbed or depressed patients in doses considerably higher than those employed for melatonin. In view that the relative potencies of the analogs are higher than that of the natural compound, clinical trials employing melatonin in the range of 50-100 mg/day are urgently needed to assess its therapeutic validity in neurodegenerative disorders such as AD.
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Affiliation(s)
- Daniel P Cardinali
- Departamento de Docencia e Investigación, Facultad de Ciencias Médicas, Pontificia Universidad Católica Argentina, Buenos Aires 1007, Argentina.
| | - Daniel E Vigo
- Departamento de Docencia e Investigación, Facultad de Ciencias Médicas, Pontificia Universidad Católica Argentina, Buenos Aires 1007, Argentina.
| | - Natividad Olivar
- Centro de Neuropsiquiatría y Neurología de la Conducta, Hospital de Clínicas "José de San Martín", Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires 1121, Argentina.
| | - María F Vidal
- Centro de Neuropsiquiatría y Neurología de la Conducta, Hospital de Clínicas "José de San Martín", Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires 1121, Argentina.
| | - Luis I Brusco
- Centro de Neuropsiquiatría y Neurología de la Conducta, Hospital de Clínicas "José de San Martín", Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires 1121, Argentina.
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15
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Melatonin modulates the expression of BCL-xl and improve the development of vitrified embryos obtained by IVF in mice. J Assist Reprod Genet 2014; 31:453-61. [PMID: 24419931 DOI: 10.1007/s10815-014-0172-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 01/02/2014] [Indexed: 12/15/2022] Open
Abstract
PURPOSE Antioxidant and anti-apoptotic effects of melatonin on development of in vitro fertilization (IVF)/vitrified two-cell mouse embryos were evaluated in this study. METHODS The IVF two-cell embryos were vitrified by cryotop, and were cultured in KSOM medium in different concentrations of melatonin (10(-6), 10(-9), 10(-12) M) and without melatonin. The blastocyst cell number, apoptotic cells and glutathione (GSH) level were evaluated by differential, TUNEL and cell tracker blue staining, respectively. The expression of Bax and Bcl-xl genes was evaluated by qPCR. The expression of melatonin receptors (Mtnr1a and Mtnr1b) in mouse 2-cell embryos and blastocysts was evaluated by RT-PCR. RESULTS Melatonin increased the rate of cleavage and blastulation at 10(-12) M concentration (p < 0.05). The number of trophectoderm and inner cell mass showed a significant increase (p < 0.05) in 10(-9) M melatonin. The 10(-9) M and 10(-12) M melatonin treatments significantly reduced (p < 0.05) the apoptotic index. The significant increase in the expression of Bcl-xl observed at 10(-9) M concentration however, reduced expression of Bax was not statistically significant. The levels of GSH in 10(-9) and 10(-12) M groups were significantly improved relative to the control group (p < 0.05). The Mtnr1a was expressed in 2-cell embryos and blastocysts in all groups, but the expression of Mntr1b was not detected. CONCLUSION Melatonin may have a special role against oxidative stress in protection of IVF/vitrified embryos.
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Lin L, Huang QX, Yang SS, Chu J, Wang JZ, Tian Q. Melatonin in Alzheimer's disease. Int J Mol Sci 2013; 14:14575-93. [PMID: 23857055 PMCID: PMC3742260 DOI: 10.3390/ijms140714575] [Citation(s) in RCA: 138] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Revised: 06/21/2013] [Accepted: 07/05/2013] [Indexed: 11/18/2022] Open
Abstract
Alzheimer’s disease (AD), an age-related neurodegenerative disorder with progressive cognition deficit, is characterized by extracellular senile plaques (SP) of aggregated β-amyloid (Aβ) and intracellular neurofibrillary tangles, mainly containing the hyperphosphorylated microtubule-associated protein tau. Multiple factors contribute to the etiology of AD in terms of initiation and progression. Melatonin is an endogenously produced hormone in the brain and decreases during aging and in patients with AD. Data from clinical trials indicate that melatonin supplementation improves sleep, ameliorates sundowning and slows down the progression of cognitive impairment in AD patients. Melatonin efficiently protects neuronal cells from Aβ-mediated toxicity via antioxidant and anti-amyloid properties. It not only inhibits Aβ generation, but also arrests the formation of amyloid fibrils by a structure-dependent interaction with Aβ. Our studies have demonstrated that melatonin efficiently attenuates Alzheimer-like tau hyperphosphorylation. Although the exact mechanism is still not fully understood, a direct regulatory influence of melatonin on the activities of protein kinases and protein phosphatases is proposed. Additionally, melatonin also plays a role in protecting the cholinergic system and in anti-inflammation. The aim of this review is to stimulate interest in melatonin as a potentially useful agent in the prevention and treatment of AD.
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Affiliation(s)
- Li Lin
- Key Laboratory of Neurological Disease of National Education Ministry and Hubei Province, Department of Pathology and Pathophysiology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; E-Mail:
- Department of Pathology and Pathophysiology, College of Medical Science, Jishou University, 120 People Road, Jishou 436100, China; E-Mails: (L.L.); (S.-S.Y.)
| | - Qiong-Xia Huang
- Department of TCM Rationale, College of Basic Medicine, Hubei University of Chinese Medicine, 1 West Road Huangjia Lake, Wuhan 430065, China; E-Mail:
| | - Shu-Sheng Yang
- Department of Pathology and Pathophysiology, College of Medical Science, Jishou University, 120 People Road, Jishou 436100, China; E-Mails: (L.L.); (S.-S.Y.)
| | - Jiang Chu
- Key Laboratory of Neurological Disease of National Education Ministry and Hubei Province, Department of Pathology and Pathophysiology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; E-Mail:
| | - Jian-Zhi Wang
- Key Laboratory of Neurological Disease of National Education Ministry and Hubei Province, Department of Pathology and Pathophysiology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; E-Mail:
- Authors to whom correspondence should be addressed; E-Mails: (J.-Z.W.); (Q.T.); Tel./Fax: +86-27-8369-3883 (J.-Z.W.); Tel.: +86-27-8369-2625 (Q.T.)
| | - Qing Tian
- Key Laboratory of Neurological Disease of National Education Ministry and Hubei Province, Department of Pathology and Pathophysiology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; E-Mail:
- Authors to whom correspondence should be addressed; E-Mails: (J.-Z.W.); (Q.T.); Tel./Fax: +86-27-8369-3883 (J.-Z.W.); Tel.: +86-27-8369-2625 (Q.T.)
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17
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De Berardis D, Marini S, Fornaro M, Srinivasan V, Iasevoli F, Tomasetti C, Valchera A, Perna G, Quera-Salva MA, Martinotti G, di Giannantonio M. The melatonergic system in mood and anxiety disorders and the role of agomelatine: implications for clinical practice. Int J Mol Sci 2013; 14:12458-83. [PMID: 23765220 PMCID: PMC3709794 DOI: 10.3390/ijms140612458] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2013] [Revised: 05/22/2013] [Accepted: 05/22/2013] [Indexed: 02/07/2023] Open
Abstract
Melatonin exerts its actions through membrane MT1/MT2 melatonin receptors, which belong to the super family of G-protein-coupled receptors consisting of the typical seven transmembrane domains. MT1 and MT2 receptors are expressed in various tissues of the body either as single ones or together. A growing literature suggests that the melatonergic system may be involved in the pathophysiology of mood and anxiety disorders. In fact, some core symptoms of depression show disturbance of the circadian rhythm in their clinical expression, such as diurnal mood and other symptomatic variation, or are closely linked to circadian system functioning, such as sleep-wake cycle alterations. In addition, alterations have been described in the circadian rhythms of several biological markers in depressed patients. Therefore, there is interest in developing antidepressants that have a chronobiotic effect (i.e., treatment of circadian rhythm disorders). As melatonin produces chronobiotic effects, efforts have been aimed at developing agomelatine, an antidepressant with melatonin agonist activity. The present paper reviews the role of the melatonergic system in the pathophysiology of mood and anxiety disorders and the clinical characteristics of agomelatine. Implications of agomelatine in "real world" clinical practice will be also discussed.
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Affiliation(s)
- Domenico De Berardis
- National Health Service, Department of Mental Health, Psychiatric Service of Diagnosis and Treatment, Hospital “G. Mazzini”, ASL 4 Teramo, Italy; E-Mail:
- Department of Neuroscience and Imaging, Chair of Psychiatry, University “G. D’Annunzio”, Chieti 66013, Italy; E-Mails: (G.M.); (M. G.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +39-0861429708; Fax: +39-0861429706
| | - Stefano Marini
- National Health Service, Department of Mental Health, Psychiatric Service of Diagnosis and Treatment, Hospital “G. Mazzini”, ASL 4 Teramo, Italy; E-Mail:
- Department of Neuroscience and Imaging, Chair of Psychiatry, University “G. D’Annunzio”, Chieti 66013, Italy; E-Mails: (G.M.); (M. G.)
| | - Michele Fornaro
- Department of “Scienze della Formazione”, University of Catania, Catania 95121, Italy; E-Mail:
| | - Venkataramanujam Srinivasan
- Sri Sathya Sai Medical Educational and Research Foundation, Medical Sciences Research Study Center, Prasanthi Nilayam, 40-Kovai Thirunagar Coimbatore, Tamilnadu 641014, India; E-Mail:
| | - Felice Iasevoli
- Laboratory of Molecular Psychiatry and Psychopharmacotherapeutics, Section of Psychiatry, Department of Neuroscience, University School of Medicine “Federico II”, Naples 80131, Italy; E-Mails: (F.I.); (C.T.)
| | - Carmine Tomasetti
- Laboratory of Molecular Psychiatry and Psychopharmacotherapeutics, Section of Psychiatry, Department of Neuroscience, University School of Medicine “Federico II”, Naples 80131, Italy; E-Mails: (F.I.); (C.T.)
| | - Alessandro Valchera
- Hermanas Hospitalarias, FoRiPsi, Villa S. Giuseppe Hospital, Ascoli Piceno 63100, Italy; E-Mail:
| | - Giampaolo Perna
- Hermanas Hospitalarias, FoRiPsi, Department of Clinical Neurosciences, Villa San Benedetto Menni, Albese con Cassano, Como 22032, Italy; E-Mail:
- Department of Psychiatry and Behavioral Sciences, Leonard Miller School of Medicine, University of Miami, 33124 Miami, USA
- Department of Psychiatry and Neuropsychology, University of Maastricht, 6200 MD Maastricht, The Netherlands
| | - Maria-Antonia Quera-Salva
- AP-HP Sleep Unit, Department of Physiology, Raymond Poincaré Hospital, Garches 92380, France; E-Mail:
| | - Giovanni Martinotti
- Department of Neuroscience and Imaging, Chair of Psychiatry, University “G. D’Annunzio”, Chieti 66013, Italy; E-Mails: (G.M.); (M. G.)
| | - Massimo di Giannantonio
- Department of Neuroscience and Imaging, Chair of Psychiatry, University “G. D’Annunzio”, Chieti 66013, Italy; E-Mails: (G.M.); (M. G.)
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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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Mao L, Cheng Q, Guardiola-Lemaître B, Schuster-Klein C, Dong C, Lai L, Hill SM. In vitro and in vivo antitumor activity of melatonin receptor agonists. J Pineal Res 2010; 49:210-21. [PMID: 20609073 DOI: 10.1111/j.1600-079x.2010.00781.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Melatonin has been shown to inhibit the proliferation of estrogen receptor α (ERα)-positive human breast cancer cells in vitro and suppress the growth of carcinogen-induced mammary tumors in rats. Melatonin's antiproliferative effect is mediated, at least in part, through the MT1 melatonin receptor and mechanisms involving modulation of the estrogen-signaling pathway. To develop melatonin analogs with greater therapeutic effects, we have examined the in vitro and in vivo antimitotic activity of two MT1/MT2 melatonin receptor agonists, S23219-1 and S23478-1. In our studies, both agonists are quite effective at suppressing the growth of MCF-7 human breast cancer cells. At a concentration of 10⁻⁶ m, S23219-1 and S23478-1 inhibited the growth of MCF-7 cells by 60% and 73%, respectively. However, S23478-1 is more effective than melatonin and S23219-1 at repressing the expression and transactivation of the ERα, and modulating the expression of pancreatic spasmolytic polypeptide (pS2), an estrogen-regulated gene. The melatonin agonist S23478-1 exhibited enhanced antitumor potency in the subsequent studies in our animal model. At a dosage of 25 mg/kg/day, S23478-1 is more efficacious than melatonin at inducing regression of the established N-nitroso-N-methyl-urea-induced rat mammary tumors. This dose of S23478-1 (25 mg/kg/day) generated a significant (P < 0.05) overall regression response of 52%. Furthermore, at this dosage, S23478-1 is more effective than melatonin at suppressing the estrogen-signaling pathway and promoting tumor cell apoptosis, significantly increasing the expression of the pro-apoptotic protein Bax, while decreasing the expression of ERα and the anti-apoptotic protein Bcl-2.
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Affiliation(s)
- Lulu Mao
- Department of Structural & Cellular Biology, Tulane University Health Sciences Center, 1430 Tulane Avenue, New Orleans, LA 70112, USA
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20
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Sampaio LDFS. An unexpected effect of 5-MCA-NAT in chick retinal development. Int J Dev Neurosci 2009; 27:511-5. [PMID: 19596433 DOI: 10.1016/j.ijdevneu.2009.07.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2009] [Revised: 06/22/2009] [Accepted: 07/01/2009] [Indexed: 10/20/2022] Open
Abstract
Luzindole is an unselective antagonist of the melatonin receptors and melatonin's other binding sites, although some exceptions have been observed in chick retinal neurodevelopment, where this unselective antagonist does not block melatonin's inhibitory effect on the adenylate cyclase enzyme, probably due to the presence of some other melatonin receptor(s) or binding site(s). The present study investigated the modulation of cyclic adenosine 3'-5'-monophosphate (cAMP) levels via MT3 melatonin-binding sites, located within the QR2 (dihydronicotinamide riboside: quinone oxidoreductase 2) enzyme, by observing the response to luzindole. Embryonic and post-hatch retinas, incubated with a selective agonist for the MT3 melatonin-binding site 5-methoxycarbonylamino-N-acetyltryptamine (5-MCA-NAT, 10 or 100 nM), had an increase in cAMP accumulation relative to control retinas. Luzindole (5microM) inhibited the 5-MCA-NAT stimulatory effect at all ages tested. The agonist 5-MCA-NAT enhanced the melatonin inhibitory effect on cAMP levels stimulated by forskolin (5microM), but not the stimulatory forskolin effect. The results suggest that MT3 melatonin-binding sites are present in embryonic and post-hatch chick retinas and that luzindole more selectively blocks the 5-MCA-NAT effect on cAMP accumulation than it blocks the melatonin inhibitory effect via G protein-coupled receptors in chick retinal neurodevelopment.
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Affiliation(s)
- Lucia de Fatima Sobral Sampaio
- Laboratório de Bioquímica do Desenvolvimento do Sistema Nervoso, Instituto de Ciências Biológicas, Universidade Federal do Pará, Rua Augusto Corrêa, 1, CEP: 66075-110 Belém, PA, Brazil.
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21
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Melatonin and breast cancer: cellular mechanisms, clinical studies and future perspectives. Expert Rev Mol Med 2009; 11:e5. [PMID: 19193248 DOI: 10.1017/s1462399409000982] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Recent studies have suggested that the pineal hormone melatonin may protect against breast cancer, and the mechanisms underlying its actions are becoming clearer. Melatonin works through receptors and distinct second messenger pathways to reduce cellular proliferation and to induce cellular differentiation. In addition, independently of receptors melatonin can modulate oestrogen-dependent pathways and reduce free-radical formation, thus preventing mutation and cellular toxicity. The fact that melatonin works through a myriad of signalling cascades that are protective to cells makes this hormone a good candidate for use in the clinic for the prevention and/or treatment of cancer. This review summarises cellular mechanisms governing the action of melatonin and then considers the potential use of melatonin in breast cancer prevention and treatment, with an emphasis on improving clinical outcomes.
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Bondi CD, McKeon RM, Bennett JM, Ignatius PF, Brydon L, Jockers R, Melan MA, Witt-Enderby PA. MT1 melatonin receptor internalization underlies melatonin-induced morphologic changes in Chinese hamster ovary cells and these processes are dependent on Gi proteins, MEK 1/2 and microtubule modulation. J Pineal Res 2008; 44:288-98. [PMID: 18339124 DOI: 10.1111/j.1600-079x.2007.00525.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Melatonin induces cellular differentiation in numerous cell types. Data show that multiple mechanisms are involved in these processes that are cell-type specific and may be receptor dependent or independent. The focus of this study was to specifically assess the role of human MT1 melatonin receptors in cellular differentiation using an MT1-Chinese hamster ovary (CHO) model; one that reproducibly produces measurable morphologic changes in response to melatonin. Using multiple approaches, we show that melatonin induces MT1-CHO cells to hyperelongate through a MEK 1/2, and ERK 1/2-dependent mechanism that is dependent upon MT1 receptor internalization, Gi protein activation, and clathrin-mediated endocytosis. Using immunoprecipitation analysis, we show that MT1 receptors form complexes with Gi(alpha) 2,3, Gq(alpha), beta-arrestin-2, MEK 1/2, and ERK 1/2 in the presence of melatonin. We also show that MEK and ERK activity that is induced by melatonin is dependent on Gi protein activation, clathrin-mediated endocytosis and is modulated by microtubules. We conclude from these studies that melatonin-induced internalization of human MT1 melatonin receptors in CHO cells is responsible for activating both MEK 1/2 and ERK 1/2 to drive these morphologic changes. These events, as mediated by melatonin, require Gi protein activation and endocytosis mediated through clathrin, to form MT1 receptor complexes with beta-arrestin-2/MEK 1/2 and ERK 1/2. The MT1-CHO model is invaluable to mapping out signaling cascades as mediated through MT1 receptors especially because it separates out MEK/ERK 1/2 activation by MT1 receptors from that of receptor tyrosine kinases.
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Affiliation(s)
- C Dominic Bondi
- Division of Pharmaceutical Sciences, School of Pharmacy, Duquesne University, Pittsburgh, PA 15282, USA
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Sampaio LDFS. Melatonin inhibitory effect on cAMP accumulation in the chick retina development. Int J Dev Neurosci 2008; 26:277-82. [PMID: 18343081 DOI: 10.1016/j.ijdevneu.2008.02.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2007] [Revised: 01/31/2008] [Accepted: 02/01/2008] [Indexed: 10/22/2022] Open
Abstract
During vertebrate neurodevelopment, neuritogenesis and synaptogenesis are modulated by intracellular cAMP rises. Melatonin, which is implicated in neuronal differentiation, mainly inhibits this pathway. Here, an investigation about the profile of this effect during the vertebrate neurodevelopment is reported. In the embryonic chick retinas at days 8, 12, 14, 16 and at 2 days post-hatched (E8, E12, E14, E16 and PH), those control embryonic retinas incubated only with the phosphodiesterase inhibitor at days corresponding to commencement of neuronal differentiation (E8, E12) and PH, presented cAMP levels inhibited by melatonin. While the cAMP accumulation stimulated by forskolin was inhibited in the embryonic retinas at all testing days. Neither the unselective antagonist N-acetyl-2-benziltryptamine (luzindole) nor the selective Mel(1b) antagonist 4-phenyl-2-propionamidotetralin (4-P-PDOT) blocked the melatonin concentration-dependent inhibitory effect on cAMP accumulation in the retinas initiating differentiation (E7-E9), suggesting a tight binding between melatonin and their receptors. However, 4-P-PDOT competitively reverted the melatonin effect on cAMP stimulated by forskolin during synaptogenesis stages. Together, the melatonin effect on cAMP levels in chick retina, which is mainly through melatonin receptors, is depending on the developmental period observed, probably taking part in the mechanisms surrounding the melatonin action on neuronal differentiation.
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Affiliation(s)
- Lucia de Fatima Sobral Sampaio
- Laboratório de Bioquímica do Desenvolvimento do Sistema Nervoso, Instituto de Ciências Biológicas, Universidade Federal do Pará, 1 Belém, PA, Brazil.
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Aust S, Brucker B, Graf J, Klimpfinger M, Thalhammer T. Melatonin modulates acid/base transport in human pancreatic carcinoma cells. Cell Physiol Biochem 2006; 18:91-102. [PMID: 16914894 DOI: 10.1159/000095173] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Melatonin was found to improve pancreatic organ function in diseased animals. To study whether pancreatic bicarbonate secretion is stimulated by melatonin, investigations were done in two human ductal pancreatic adenocarcinoma cell lines MIA PaCa-2 (MIA) and PANC-1 (PANC). Using the fluorescence pH-sensor BCECF-AM, we monitored melatonin effects on basal intracellular pH (pH(i)), and on pH(i) recovery after intracellular alkalinization produced by the removal of extracellular HCO(3) (-)/CO(2). Exposure to 1 microM melatonin for 24 hrs and presence of the indoleamine during the experiment increases the basal pH(i). Moreover, pHi recovery and HCO(3) (-) secretion are facilitated after the alkaline load. These findings are in line with the observed increase in mRNA expression of the Na(+)/HCO(3) (-)-cotransporter SLC4A4b for the uptake and the Cl(-)/HCO(3) (-)-exchanger SLC26A6 for the secretion of HCO(3) (-). The reduction in Na(+)/H(+)- exchanger SLC9A1 mRNA would favor pH(i) recovery after alkalinization, but it does not explain the initial increase in pHi. This controversial effect and the requirement for continuous presence of melatonin throughout the experiment suggest that nontranscriptional signalling may contribute to the effects of melatonin on acid/base movements. In summary, we show a stimulatory effect of melatonin on bicarbonate secretion in the pancreatic cancer cell lines which may help to prevent duodenal damage.
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Affiliation(s)
- Sylvia Aust
- Department of Pathophysiology, Center for Physiology and Pathophysiology, Vienna General Hospital, Vienna, Austria
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Valero N, Espina LM, Mosquera J. Melatonin Decreases Nitric oxide Production, Inducible Nitric oxide Synthase Expression and Lipid Peroxidation Induced by Venezuelan Encephalitis Equine Virus in Neuroblastoma Cell Cultures. Neurochem Res 2006; 31:925-32. [PMID: 16804753 DOI: 10.1007/s11064-006-9098-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/05/2006] [Indexed: 11/26/2022]
Abstract
Increased expression of inducible nitric oxide synthase has been shown in murine Venezuelan equine encephalitis (VEE) virus infection. In this experimental model, melatonin (MTL) treatment has shown to be beneficial. The aim of this study was to determine the effect of VEE virus on the nitric oxide (NO) production and lipid peroxidation in neuroblastoma cell cultures, and to investigate the role of MTL during cell-virus interaction. Neuroblastoma cells were co-cultured with VEE virus and treated with MTL at doses ranging from 0 to 1.8 mM, for 6, 12, 24 and 48 h. NO and lipid peroxidation were measured in culture supernatants and in the cellular content by nitrite concentration and thiobarbituric acid assay, respectively. Expression of inducible nitric oxide synthase (iNOS) was determined by indirect immunofluorescence. Increased production of NO and lipid peroxidation products were found in supernatants and cellular contents of VEE virus treated cultures. Both NO and lipid peroxidation were decreased by MTL treatment in a time dependent manner. Increased iNOS expression was observed in VEE virus infected cultures that was reduced by MTL treatment. These results could be related to the beneficial role of MTL in the VEE experimental disease and address the possible therapeutic potential of the hormone in human VEE virus infection.
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Affiliation(s)
- Nereida Valero
- Seccion de Virologia, Instituto de Investigaciones Clinicas Dr. Americo Negrette, Facultad de Medicina, Universidad del Zulia, Apartado Postal 23, Maracaibo, Estado Zulia, 4001-A, Venezuela.
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Abstract
Alzheimer disease (AD), an age-related neurodegenerative disorder with progressive loss of memory and deterioration of comprehensive cognition, is characterized by extracellular senile plaques of aggregated beta-amyloid (Abeta), and intracellular neurofibrillary tangles that contain hyperphosphorylated tau protein. Recent studies showed that melatonin, an indoleamine secreted by the pineal gland, may play an important role in aging and AD as an antioxidant and neuroprotector. Melatonin decreases during aging and patients with AD have a more profound reduction in this hormone. Data from clinical trials indicate that melatonin supplementation improves sleep, ameliorates sundowning, and slows down the progression of cognitive impairment in Alzheimer patients. Melatonin efficiently protects neuronal cells from Abeta-mediated toxicity via antioxidant and anti-amyloid properties: it not only inhibits Abeta generation, but also arrests the formation of amyloid fibrils by a structure-dependent interaction with Abeta. Our recent studies have demonstrated that melatonin efficiently attenuates Alzheimer-like tau hyperphosphorylation. Although the exact mechanism is still not fully understood, a direct regulatory influence of melatonin on the activities of protein kinases and protein phosphatases is proposed. Additionally, melatonin also plays a role in protecting cholinergic neurons and in anti-inflammation. Here, the neuroprotective effects of melatonin and the underlying mechanisms by which it exerts its effects are reviewed. The capacity of melatonin to prevent or ameliorate tau and Abeta pathology further enhances its potential in the prevention or treatment of AD.
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Affiliation(s)
- Jian-zhi Wang
- Pathophysiology Department, Key Laboratory of Neurological Diseases of Hubei Province, Tongji Medical School, Huazhong University of Science and Technology, Wuhan, China.
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de Almeida-Paula LD, Costa-Lotufo LV, Silva Ferreira Z, Monteiro AEG, Isoldi MC, Godinho RO, Markus RP. Melatonin modulates rat myotube-acetylcholine receptors by inhibiting calmodulin. Eur J Pharmacol 2005; 525:24-31. [PMID: 16297382 DOI: 10.1016/j.ejphar.2005.09.056] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2005] [Revised: 09/12/2005] [Accepted: 09/21/2005] [Indexed: 11/17/2022]
Abstract
Melatonin, the pineal gland hormone, modulates alpha-bungarotoxin sensitive nicotinic acetylcholine receptors in sympathetic nerve terminals, cerebellum and chick retina imposing a diurnal variation in functional responses [Markus, R.P., Zago, W.M., Carneiro, R.C., 1996. Melatonin modulation of presynaptic nicotinic acetylcholine receptors in the rat vas deferens. J. Pharmacol. Exp. Ther. 279, 18-22; Markus, R.P., Santos, J.M., Zago, W., Reno, L.A., 2003. Melatonin nocturnal surge modulates nicotinic receptors and nicotine-induced [3HI] glutamate release in rat cerebellum slices. J. Pharmacol. Exp. Ther. 305, 525-530; Sampaio, L.F.S., Hamassaki-Britto, D.E., Markus, R.P., 2005. Influence of melatonin on the development of functional nicotinic acetylcholine receptors in cultured chick retinal cells. Braz. J. Med. Biol. Res. 38, 603-613]. Here we show that in rat myotubes forskolin and melatonin reduced the number of nicotinic acetylcholine receptors expressed in plasma membrane. In addition, these cells expressed melatonin MT1 receptors, which are known to be coupled to G(i)-protein. However, the pharmacological profile of melatonin analogs regarding the reduction in cyclic AMP accumulation and number of nicotinic acetylcholine receptors did not point to a mechanism mediated by activation of G(i)-protein coupled receptors. On the other hand, calmidazolium, a classical inhibitor of calmodulin, reduced in a similar manner both effects. Considering that one isoform of adenylyl cyclase present in rat myotubes is regulated by Ca2+/calmodulin, we propose that melatonin modulates the number of nicotinic acetylcholine receptors via reduction in cyclic AMP accumulation.
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MESH Headings
- Animals
- Calmodulin/antagonists & inhibitors
- Cells, Cultured
- Cyclic AMP/metabolism
- Cyclic GMP/metabolism
- Gene Expression Regulation/drug effects
- Melatonin/pharmacology
- Muscle Fibers, Skeletal/drug effects
- Muscle Fibers, Skeletal/metabolism
- RNA, Messenger/metabolism
- Rats
- Receptor, Melatonin, MT1/genetics
- Receptor, Melatonin, MT1/metabolism
- Receptor, Melatonin, MT2/genetics
- Receptor, Melatonin, MT2/metabolism
- Receptors, Nicotinic/drug effects
- Receptors, Nicotinic/metabolism
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