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Nair PS, Zadeh-Haghighi H, Simon C. Radical pair model for magnetic field effects on NMDA receptor activity. Sci Rep 2024; 14:3628. [PMID: 38351304 PMCID: PMC10864372 DOI: 10.1038/s41598-024-54343-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 02/12/2024] [Indexed: 02/16/2024] Open
Abstract
The N-methyl-D-aspartate receptor is a prominent player in brain development and functioning. Perturbations to its functioning through external stimuli like magnetic fields can potentially affect the brain in numerous ways. Various studies have shown that magnetic fields of varying strengths affect these receptors. We propose that the radical pair mechanism, a quantum mechanical process, could explain some of these field effects. Radicals of the form [Formula: see text], where R is a protein residue that can be Serine or Tyrosine, are considered for this study. The variation in the singlet fractional yield of the radical pairs, as a function of magnetic field strength, is calculated to understand how the magnetic field affects the products of the radical pair reactions. Based on the results, the radical pair mechanism is a likely candidate for explaining the magnetic field effects observed on the receptor activity. The model predicts changes in the behaviour of the system as magnetic field strength is varied and also predicts certain isotope effects. The results further suggest that similar effects on radical pairs could be a plausible explanation for various magnetic field effects within the brain.
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Affiliation(s)
- Parvathy S Nair
- Department of Physics, Indian Institute of Science Education and Research (IISER), Tirupati, Tirupati, Andhra Pradesh, 517507, India.
| | - Hadi Zadeh-Haghighi
- Department of Physics and Astronomy, University of Calgary, Calgary, AB, T2N 1N4, Canada.
- Institute for Quantum Science and Technology, University of Calgary, Calgary, AB, T2N 1N4, Canada.
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 1N4, Canada.
| | - Christoph Simon
- Department of Physics and Astronomy, University of Calgary, Calgary, AB, T2N 1N4, Canada.
- Institute for Quantum Science and Technology, University of Calgary, Calgary, AB, T2N 1N4, Canada.
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 1N4, Canada.
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Hirai T, Wang W, Murono N, Iwasa K, Inoue M. Potential role of Akt in the regulation of fibroblast growth factor 21 by berberine. J Nat Med 2024; 78:169-179. [PMID: 37951850 DOI: 10.1007/s11418-023-01755-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 10/16/2023] [Indexed: 11/14/2023]
Abstract
Fibroblast growth factor 21 (FGF21) is expressed in several organs, including the liver, adipose tissue, and cardiovascular system, and plays an important role in cross-talk with other organs by binding to specific FGF receptors and their co-receptors. FGF21 represents a potential target for the treatment of obesity, type 2 diabetes mellitus, and non-alcoholic steatohepatitis (NASH). The production of FGF21 in skeletal muscle was recently suggested to be beneficial for metabolic health through its autocrine and paracrine effects. However, the regulatory mechanisms of FGF21 in skeletal muscle remain unclear. In the present study, we showed that berberine regulated FGF21 production in C2C12 myotubes in a dose-dependent manner. We also examined the effects of A-674563, a selective Akt1 inhibitor, on the berberine-mediated regulation of FGF21 expression in C2C12 myotubes. Berberine significantly increased the secretion of FGF21 in C2C12 myotubes, while A-674563 attenuated this effect. Moreover, a pre-treatment with A-674563 effectively suppressed berberine-induced increases in Bmal1 expression in C2C12 myotubes, indicating that the up-regulation of Bmal1 after the berberine treatment was dependent on Akt1. Additionally, berberine-induced increases in FGF21 secretion were significantly attenuated in C2C12 cells transfected with Bmal1 siRNA, indicating the contribution of the core clock transcription factor BMAL1 to Akt-regulated FGF21 in response to berberine. Collectively, these results indicate that berberine regulates the expression of FGF21 through the Akt1 pathway in C2C12 myotubes. Moreover, the core clock gene Bmal1 may participate in the control of the myokine FGF21. Berberine stimulated Akt1-dependent FGF21 expression in C2C12 myotubes. The up-regulation of FGF21 through the modulation of PI3K/AKT1/BMAL1 in response to berberine may be involved in the regulation of cellular function (such as Glut1 expression) by acting in an autocrine and/or paracrine manner in skeletal muscle.
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Affiliation(s)
- Takao Hirai
- Laboratory of Medicinal Resources, School of Pharmacy, Aichi Gakuin University, Nagoya, 464-8650, Japan.
- Laboratory of Biochemical Pharmacology, Department of Health and Medical Sciences, Ishikawa Prefectural Nursing University, 1-1 Gakuendai, Kahoku, Ishikawa, 929-1210, Japan.
| | - Wei Wang
- Laboratory of Medicinal Resources, School of Pharmacy, Aichi Gakuin University, Nagoya, 464-8650, Japan
| | - Naoko Murono
- Community Health Nursing, Ishikawa Prefectural Nursing University, Kahoku, Ishikawa, 929-1210, Japan
| | - Kazuo Iwasa
- Department of Health and Medical Sciences, Ishikawa Prefectural Nursing University, Kahoku, Ishikawa, 929-1210, Japan
| | - Makoto Inoue
- Laboratory of Medicinal Resources, School of Pharmacy, Aichi Gakuin University, Nagoya, 464-8650, Japan
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Static Magnetic Field Exposure In Vivo Enhances the Generation of New Doublecortin-expressing Cells in the Sub-ventricular Zone and Neocortex of Adult Rats. Neuroscience 2019; 425:217-234. [PMID: 31809729 DOI: 10.1016/j.neuroscience.2019.11.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 11/01/2019] [Accepted: 11/04/2019] [Indexed: 01/28/2023]
Abstract
Static magnetic field (SMF) is gaining interest as a potential technique for modulating CNS neuronal activity. Previous studies have shown a pro-neurogenic effect of short periods of extremely low frequency pulsatile magnetic fields (PMF) in vivo and pro-survival effect of low intensity SMF in cultured neurons in vitro, but little is known about the in vivo effects of low to moderate intensity SMF on brain functions. We investigated the effect of continuously-applied SMF on subventricular zone (SVZ) neurogenesis and immature doublecortin (DCX)-expressing cells in the neocortex of young adult rats and in primary cultures of cortical neurons in vitro. A small (3 mm diameter) magnetic disc was implanted on the skull of rats at bregma, producing an average field strength of 4.3 mT at SVZ and 12.9 mT at inner neocortex. Levels of proliferation of SVZ stem cells were determined by 5-ethynyl-2'-deoxyuridine (EdU) labelling, and early neuronal phenotype development was determined by expression of doublecortin (DCX). To determine the effect of SMF on neurogenesis in vitro, permanent magnets were placed beneath the culture dishes. We found that low intensity SMF exposure enhances cell proliferation in SVZ and new DCX-expressing cells in neocortical regions of young adult rats. In primary cortical neuronal cultures, SMF exposure increased the expression of newly generated cells co-labelled with EdU and DCX or the mature neuronal marker NeuN, while activating a set of pro neuronal bHLH genes. SMF exposure has potential for treatment of neurodegenerative disease and conditions such as CNS trauma and affective disorders in which increased neurogenesis is desirable.
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Rivadulla C, Aguilar J, Coletti M, Aguila J, Prieto S, Cudeiro J. Static magnetic fields reduce epileptiform activity in anesthetized rat and monkey. Sci Rep 2018; 8:15985. [PMID: 30375430 PMCID: PMC6207659 DOI: 10.1038/s41598-018-33808-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 10/05/2018] [Indexed: 02/06/2023] Open
Abstract
Increasing evidence indicates that static magnetic fields (SMF) reduce cortical activity in both human and animal models. The aim of this work was to investigate the effect of SMF on epileptiform cortical activity, a condition related to an abnormal increase in neuronal excitability. The first experimental block included a Pilocarpine rat model of epilepsy, in which a magnetic neodymium nickel-plated cylinder, a magnetic field of 0.5 T, or “sham” were placed over the skull. In the second experimental block, we recorded epileptic-like activity in the visual cortex of a monkey (Macaca mulatta) under control conditions and in the presence of the magnet. Between 15 and 30 minutes after the second dose of Pilocarpine, EEG changes compatible with seizure like events induced by Pilocarpine were clearly observed in the control animals (sham stimulation). Similar effects were visible in the animals exposed to the real magnet after 1–2 hours. In the monkey, SMF over the cortical focus clearly reduced abnormal activity: the intensity threshold for visual induction increased and the severity and duration decreased. These results reinforce the view that static magnets modulate cortical activity and open the door to the future therapeutic use of SMF in epilepsy as a complement to current pharmacological treatments.
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Affiliation(s)
- Casto Rivadulla
- NEUROcom, School of Health Sciences University of A Coruna, and Agrupación estratégica CICA-INIBIC - UdC, A Coruna, Spain.
| | - Juan Aguilar
- Laboratorio de Neurofisiología Experimental, Hospital Nacional de Parapléjicos, Servicio de Salud de Castilla-La Mancha, Toledo, Spain.
| | - Marcos Coletti
- NEUROcom, School of Health Sciences University of A Coruna, and Agrupación estratégica CICA-INIBIC - UdC, A Coruna, Spain
| | - Jordi Aguila
- NEUROcom, School of Health Sciences University of A Coruna, and Agrupación estratégica CICA-INIBIC - UdC, A Coruna, Spain
| | - Sandra Prieto
- NEUROcom, School of Health Sciences University of A Coruna, and Agrupación estratégica CICA-INIBIC - UdC, A Coruna, Spain
| | - Javier Cudeiro
- NEUROcom, School of Health Sciences University of A Coruna, and Agrupación estratégica CICA-INIBIC - UdC, A Coruna, Spain.,Cerebral Stimulation Centre of Galicia, A Coruna, Spain
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Albuquerque WWC, Costa RMPB, Fernandes TDSE, Porto ALF. Evidences of the static magnetic field influence on cellular systems. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2016; 121:16-28. [DOI: 10.1016/j.pbiomolbio.2016.03.003] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 03/10/2016] [Indexed: 01/29/2023]
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Ben Yakir-Blumkin M, Loboda Y, Schächter L, Finberg JPM. Neuroprotective effect of weak static magnetic fields in primary neuronal cultures. Neuroscience 2014; 278:313-26. [PMID: 25171788 DOI: 10.1016/j.neuroscience.2014.08.029] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2013] [Revised: 08/13/2014] [Accepted: 08/19/2014] [Indexed: 12/20/2022]
Abstract
Low intensity static magnetic fields (SMFs) interact with various biological tissues including the CNS, thereby affecting key biological processes such as gene expression, cell proliferation and differentiation, as well as apoptosis. Previous studies describing the effect of SMFs on apoptotic cell death in several non-neuronal cell lines, emphasize the importance of such a potential modulation in the case of neurodegenerative disorders, where apoptosis constitutes a major route via which neurons degenerate and die. In this study, we examine the effect of SMFs on neuronal survival in primary cortical and hippocampal neurons that constitute a suitable experimental system for modeling the neurodegenerative state in vitro. We show that weak SMF exposure interferes with the apoptotic programing in rat primary cortical and hippocampal neurons, thereby providing protection against etoposide-induced apoptosis in a dose- and time-dependent manner. Primary cortical neurons exposed to SMF (50G) for 7days exhibited a 57.1±6.3% decrease in the percentage of cells undergoing apoptosis induced by etoposide (12μM), accompanied by a marked decrease in the expression of the pro-apoptotic markers: cleaved poly ADP ribose polymerase-1, cleaved caspase-3, active caspase-9 and the phospho-histone H2A variant (Ser139) by 41.0±5.0%, 81.2±5.0%, 72.9±6.4%, 42.75±2.9%, respectively, and by a 57.2±1.0% decrease in the extent of mitochondrial membrane potential collapse. Using the L-type voltage-gated Ca(2+) channel inhibitor nifedipine, which is selective to Ca(2+) influx through Cav1.2, we found that the anti-apoptotic effect of SMFs was mediated by Ca(2+) influx through these channels. Our findings demonstrating altered Ca(2+)-influx in response to thapsigargin stimulation in SMF-exposed cortical neurons, along with enhanced inhibition of KCl-induced Ca(2+)-influx through Cav1.2 channels and enhanced expression of Cav1.2 and Cav1.3 channels, allude to the involvement of voltage- and store-operated Ca(2+) channels in various aspects of the protective effect exerted by SMFs. These findings show the potential susceptibility of the CNS to weak SMF exposure and have implications for the design of novel strategies for the treatment and/or prevention of neurodegenerative diseases.
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Affiliation(s)
- M Ben Yakir-Blumkin
- Department of Molecular Pharmacology, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, 31096 Haifa, Israel.
| | - Y Loboda
- Department of Molecular Pharmacology, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, 31096 Haifa, Israel.
| | - L Schächter
- Faculty of Electrical Engineering, Technion - Israel Institute of Technology, 32000 Haifa, Israel.
| | - J P M Finberg
- Department of Molecular Pharmacology, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, 31096 Haifa, Israel.
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Takarada T, Nakamichi N, Kawagoe H, Ogura M, Fukumori R, Nakazato R, Fujikawa K, Kou M, Yoneda Y. Possible neuroprotective property of nicotinic acetylcholine receptors in association with predominant upregulation of glial cell line-derived neurotrophic factor in astrocytes. J Neurosci Res 2012; 90:2074-85. [DOI: 10.1002/jnr.23101] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Revised: 05/16/2012] [Accepted: 05/24/2012] [Indexed: 11/11/2022]
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Nakamura Y, Nakamichi N, Takarada T, Ogita K, Yoneda Y. Transferrin receptor-1 suppresses neurite outgrowth in neuroblastoma Neuro2A cells. Neurochem Int 2011; 60:448-57. [PMID: 22019713 DOI: 10.1016/j.neuint.2011.08.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Revised: 08/24/2011] [Accepted: 08/25/2011] [Indexed: 10/16/2022]
Abstract
Transferrin receptor-1 (TfR1) is a cell membrane-associated glycoprotein responsible for incorporation of the iron bound to transferrin through an endocytotic process from the circulating blood. Iron is believed to play a dual role as an active center of the electron transfer system in mitochondria and as an endogenous cytotoxin through promoted generation of reactive oxygen species in different eukaryotic cells. In this study, we evaluated expression profiles of different genes related to iron mobilization across plasma membranes in neuronal cells. Marked mRNA expression was seen for various iron-related genes such as TfR1 in cultured mouse neocortical neurons, while TfR1 mRNA levels were more than doubled during culture from 3 to 6days. In mouse embryonal carcinoma P19 cells endowed to differentiate into neuronal and astroglial lineages, a transient increase was seen in both mRNA and corresponding protein for TfR1 in association with neuronal marker expression during culture with all-trans retinoic acid (ATRA). In neuronal Neuro2A cells cultured with ATRA, moreover, neurite was elongated together with increased expression of both mRNA and protein for TfR1. Overexpression of TfR1 significantly decreased the length of neurite elongated, however, while significant promotion was invariably seen in the neurite elongation in Neuro2A cells transfected with TfR1 siRNA as well as in Neuro2A cells cultured with an iron chelator. These results suggest that TfR1 would be highly expressed by neurons rather than astroglia to play a negative role in the neurite outgrowth after the incorporation of circulating transferrin in the brain.
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Affiliation(s)
- Yukary Nakamura
- Laboratory of Molecular Pharmacology, Division of Pharmaceutical Sciences, Kanazawa University Graduate School of Natural Science and Technology, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
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Kambe Y, Nakamichi N, Takarada T, Fukumori R, Nakazato R, Hinoi E, Yoneda Y. A possible pivotal role of mitochondrial free calcium in neurotoxicity mediated by N-methyl-d-aspartate receptors in cultured rat hippocampal neurons. Neurochem Int 2011; 59:10-20. [PMID: 21669242 DOI: 10.1016/j.neuint.2011.03.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Revised: 03/11/2011] [Accepted: 03/23/2011] [Indexed: 01/03/2023]
Abstract
We have previously shown that mitochondrial membrane potential disruption is involved in mechanisms underlying differential vulnerabilities to the excitotoxicity mediated by N-methyl-d-aspartate (NMDA) receptors between primary cultured neurons prepared from rat cortex and hippocampus. To further elucidate the role of mitochondria in the excitotoxicity after activation of NMDA receptors, neurons were loaded with the fluorescent dye calcein diffusible in the cytoplasm and organelles for determination of the activity of mitochondrial permeability transition pore (mPTP) responsible for the leakage of different mitochondrial molecules. The addition of CoCl(2) similarly quenched the intracellular fluorescence except mitochondria in both cultured neurons, while further addition of NMDA led to a leakage of the dye into the cytoplasm in hippocampal neurons only. An mPTP inhibitor prevented the NMDA-induced loss of viability in hippocampal neurons, while an activator of mPTP induced a similarly potent loss of viability in cortical and hippocampal neurons. Although NMDA was more effective in increasing rhodamine-2 fluorescence as a mitochondrial calcium indicator in hippocampal than cortical neurons, a mitochondrial calcium uniporter inhibitor significantly prevented the NMDA-induced loss of viability in hippocampal neurons. Expression of mRNA was significantly higher for the putative uniporter uncoupling protein-2 in hippocampal than cortical neurons. These results suggest that mitochondrial calcium uniporter would be at least in part responsible for the NMDA neurotoxicity through a mechanism relevant to promotion of mPTP orchestration in hippocampal neurons.
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Affiliation(s)
- Yuki Kambe
- Laboratory of Molecular Pharmacology, Division of Pharmaceutical Sciences, Kanazawa University Graduate School of Natural Science and Technology, Kanazawa, Ishikawa 920-1192, Japan
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Li J, Ye L, Cook DR, Wang X, Liu J, Kolson DL, Persidsky Y, Ho WZ. Soybean-derived Bowman-Birk inhibitor inhibits neurotoxicity of LPS-activated macrophages. J Neuroinflammation 2011; 8:15. [PMID: 21324129 PMCID: PMC3046894 DOI: 10.1186/1742-2094-8-15] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2010] [Accepted: 02/15/2011] [Indexed: 12/12/2022] Open
Abstract
Background Lipopolysaccharide (LPS), the major component of the outer membrane of gram-negative bacteria, can activate immune cells including macrophages. Activation of macrophages in the central nervous system (CNS) contributes to neuronal injury. Bowman-Birk inhibitor (BBI), a soybean-derived protease inhibitor, has anti-inflammatory properties. In this study, we examined whether BBI has the ability to inhibit LPS-mediated macrophage activation, reducing the release of pro-inflammatory cytokines and subsequent neurotoxicity in primary cortical neural cultures. Methods Mixed cortical neural cultures from rat were used as target cells for testing neurotoxicity induced by LPS-treated macrophage supernatant. Neuronal survival was measured using a cell-based ELISA method for expression of the neuronal marker MAP-2. Intracellular reactive oxygen species (ROS) production in macrophages was measured via 2', 7'-dichlorofluorescin diacetate (DCFH2DA) oxidation. Cytokine expression was determined by quantitative real-time PCR. Results LPS treatment of macrophages induced expression of proinflammatory cytokines (IL-1β, IL-6 and TNF-α) and of ROS. In contrast, BBI pretreatment (1-100 μg/ml) of macrophages significantly inhibited LPS-mediated induction of these cytokines and ROS. Further, supernatant from BBI-pretreated and LPS-activated macrophage cultures was found to be less cytotoxic to neurons than that from non-BBI-pretreated and LPS-activated macrophage cultures. BBI, when directly added to the neuronal cultures (1-100 μg/ml), had no protective effect on neurons with or without LPS-activated macrophage supernatant treatment. In addition, BBI (100 μg/ml) had no effect on N-methyl-D-aspartic acid (NMDA)-mediated neurotoxicity. Conclusions These findings demonstrate that BBI, through its anti-inflammatory properties, protects neurons from neurotoxicity mediated by activated macrophages.
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Affiliation(s)
- Jieliang Li
- Department of Pathology & Laboratory Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania, USA
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Nakamichi N, Fukumori R, Takarada T, Kambe Y, Yamamoto T, Matsushima N, Moriguchi N, Yoneda Y. Preferential inhibition by antidiarrheic 2-methoxy-4-methylphenol of Ca(2+) influx across acquired N-methyl-D-aspartate receptor channels composed of NR1/NR2B subunit assembly. J Neurosci Res 2010; 88:2483-93. [PMID: 20623618 DOI: 10.1002/jnr.22399] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In our previous studies, particular phenolic ingredients, such as 2-methoxy-4-methylphenol (2M4MP), of the antidiarrheic drug wood creosote significantly prevented cell death by both hydrogen peroxide and glutamate in cultured rat hippocampal neurons. In this study, we further evaluated the pharmacological properties of 2M4MP on Ca(2+) influx across native and acquired N-methyl-D-aspartate (NMDA) receptor (NMDAR) channels. The addition of 2M4MP significantly prevented the loss of cellular viability and the increase in intracellular free Ca(2+) levels as determined by Fluo-3 in cultured rat hippocampal neurons briefly exposed to NMDA. Brief exposure to NMDA also led to a marked increase in mitochondrial free Ca(2+) levels determined by Rhod-2, in addition to intracellular free Ca(2+) levels, in HEK293 cells expressing either NR1/NR2A or NR1/NR2B subunit channels. The further addition of the general NMDAR channel blocker dizocilpine similarly inhibited the increase of intracellular Ca(2+) levels by NMDA in both types of acquired NMDAR channels, whereas the NR2B subunit selective antagonist ifenprodil drastically inhibited the increase by NMDA in HEK293 cells expressing NR1/NR2B, but not NR1/NR2A, subunits. Similarly, 2M4MP significantly and selectively inhibited the NMDA-induced influx of Ca(2+) across acquired NR1/NR2B channels in a concentration-dependent manner. Moreover, prior daily oral administration of 2M4MP significantly reduced the infarct volume in the ipsilateral cerebral hemisphere in rats with middle cerebral artery occlusion 1 day after reperfusion. These results suggest that 2M4MP may protect neurons from excitotoxicity through preferential inhibition of Ca(2+) influx across NMDAR channels composed of NR1/NR2B subunits.
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Affiliation(s)
- Noritaka Nakamichi
- Laboratory of Molecular Pharmacology, Division of Pharmaceutical Sciences, Kanazawa University Graduate School of Natural Science and Technology, Kanazawa, Ishikawa, Japan
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Fukumori R, Nakamichi N, Takarada T, Kambe Y, Matsushima N, Moriguchi N, Yoneda Y. Inhibition by 2-Methoxy-4-ethylphenol of Ca2+ Influx Through Acquired and Native N-Methyl-D-aspartate–Receptor Channels. J Pharmacol Sci 2010; 112:273-81. [DOI: 10.1254/jphs.09294fp] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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Nakamichi N, Ishioka Y, Hirai T, Ozawa S, Tachibana M, Nakamura N, Takarada T, Yoneda Y. Possible promotion of neuronal differentiation in fetal rat brain neural progenitor cells after sustained exposure to static magnetism. J Neurosci Res 2009; 87:2406-17. [PMID: 19382241 DOI: 10.1002/jnr.22087] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We have previously shown significant potentiation of Ca(2+) influx mediated by N-methyl-D-aspartate receptors, along with decreased microtubules-associated protein-2 (MAP2) expression, in hippocampal neurons cultured under static magnetism without cell death. In this study, we investigated the effects of static magnetism on the functionality of neural progenitor cells endowed to proliferate for self-replication and differentiate into neuronal, astroglial, and oligodendroglial lineages. Neural progenitor cells were isolated from embryonic rat neocortex and hippocampus, followed by culture under static magnetism at 100 mT and subsequent determination of the number of cells immunoreactive for a marker protein of particular progeny lineages. Static magnetism not only significantly decreased proliferation of neural progenitor cells without affecting cell viability, but also promoted differentiation into cells immunoreactive for MAP2 with a concomitant decrease in that for an astroglial marker, irrespective of the presence of differentiation inducers. In neural progenitors cultured under static magnetism, a significant increase was seen in mRNA expression of several activator-type proneural genes, such as Mash1, Math1, and Math3, together with decreased mRNA expression of the repressor type Hes5. These results suggest that sustained static magnetism could suppress proliferation for self-renewal and facilitate differentiation into neurons through promoted expression of activator-type proneural genes by progenitor cells in fetal rat brain.
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Affiliation(s)
- Noritaka Nakamichi
- Laboratory of Molecular Pharmacology, Division of Pharmaceutical Sciences, University Graduate School of Natural Science and Technology, Kanazawa, Japan
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Abstract
There is increasing interest in using permanent magnets for therapeutic purposes encouraged by basic science publications and clinical reports. Magnetotherapy provides a non invasive, safe, and easy method to directly treat the site of injury, the source of pain and inflammation, and other types of disease. The physiological bases for the use of magnetic fields for tissue repair as well as physical principles of dosimetry and application of various magnetic fields are subjects of this review. Analysis of the magnetic and electromagnetic stimulation is followed by a discussion of the advantage of magnetic field stimulation compared with electric current and electric field stimulation.
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Park SH, Choi SH, Lee J, Kang S, Shin YC, Kim HJ, Kim HJ, Shin SK, Lee MS, Shin KH. Effects of repeated citalopram treatments on chronic mild stress-induced growth associated protein-43 mRNA expression in rat hippocampus. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2008; 12:117-23. [PMID: 20157404 DOI: 10.4196/kjpp.2008.12.3.117] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Although growth associated protein-43 (GAP-43) is known to play a significant role in the regulation of axonal growth and the formation of new neuronal connections in the hippocampus, there is only a few studies on the effects of acute stress on GAP-43 mRNA expression in the hippocampus. Moreover, the effects of repeated citalopram treatment on chronic mild stress (CMS)-induced changes in GAP-43 mRNA expression in the hippocampus have not been explored before. To explore this question, male rats were exposed to acute immobilization stress or CMS. Also, citalopram was given prior to stress everyday during CMS procedures. Acute immobilization stress significantly increased GAP-43 mRNA expression in all subfields of the hippocampus, while CMS significantly decreased GAP-43 mRNA expression in the dentate granule cell layer (GCL). Repeated citalopram treatment decreased GAP-43 mRNA expression in the GCL compared with unstressed controls, but this decrease was not further potentiated by CMS exposure. Similar decreases in GAP-43 mRNA expression were observed in CA1, CA3 and CA4 areas of the hippocampus only after repeated citalopram treatment in CMS-exposed rats. This result indicates that GAP-43 mRNA expression in the hippocampus may differently respond to acute and chronic stress, and that repeated citalopram treatment does not change CMS-induced decreases in GAP-43 mRNA expression in the GCL.
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Affiliation(s)
- Sang-Ha Park
- Department of Pharmacology, Korea University College of Medicine, Seoul 136-701, Korea
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Xu J, Zhang QG, Li C, Zhang GY. Subtoxic N-methyl-D-aspartate delayed neuronal death in ischemic brain injury through TrkB receptor- and calmodulin-mediated PI-3K/Akt pathway activation. Hippocampus 2007; 17:525-37. [PMID: 17492691 DOI: 10.1002/hipo.20289] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Previous studies have shown that subtoxic NMDA moderated the neuronal survival in vitro and vivo. We performed this experiment to clarify the precise mechanism underlie subtoxic NMDA delayed neuronal death in ischemic brain injury. We found that pretreatment of NMDA (100 mg/kg) increased the number of the surviving CA1 pyramidal cells of hippocampus at 5 days of reperfusion. This dose of NMDA could also enhance Akt activation after ischemia/reperfusion (I/R). Here, we examined the possible mechanism that NMDA induced Akt activation. On the one hand, we found NMDA receptor-mediated Akt activation was associated with increased expression of BDNF (brain-derived neurotrophic factor) and activation of its high-affinity receptor TrkB after I/R in the hippocampus CA1 region, which could be held down by TrkB receptor antagonist K252a. On the other hand, we found that NMDA enhanced the binding of Ca2+-dependent calmodulin (CaM) to p85 (the regulation subunit of PI-3K), which led to the activation of Akt. W-13, an active CaM inhibitor, prevented the combination of CaM and p85 and subsequent Akt activation. Furthermore, NMDA receptor-mediated Akt activation was reversed by combined treatment with LY294002, the specific blockade of PI-3K. Taken together, our results suggested that subtoxic NMDA exerts the neuroprotective effect via activation of prosurvival PI-3K/Akt pathway against ischemic brain injury, and BDNF-TrkB signaling and Ca2+-dependent CaM cascade might contribute to NMDA induced activation of PI-3K/Akt pathway.
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Affiliation(s)
- Jing Xu
- Research Center for Biochemistry and Molecular Biology, The Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical College, Jiangsu, People's Republic of China
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17
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Matsushima N, Nakamichi N, Kambe Y, Takano K, Moriguchi N, Yoneda Y. Cytoprotective properties of phenolic antidiarrheic ingredients in cultured astrocytes and neurons of rat brains. Eur J Pharmacol 2007; 567:59-66. [PMID: 17475240 DOI: 10.1016/j.ejphar.2007.03.034] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2006] [Revised: 03/06/2007] [Accepted: 03/08/2007] [Indexed: 10/23/2022]
Abstract
We have previously shown that particular phenolic antidiarrheic ingredients, including 2-methoxy-4-methylphenol (2M4MP) and 2-methoxy-4-ethyphenol (2M4EP), but not 2-methoxyphenol (2MP), significantly inhibit cellular maturation and differentiation of the bone-resorbing osteoclasts with concomitant protection of the bone-forming osteoblasts against oxidative stress by hydrogen peroxide (H(2)O(2)). In the present study, we evaluated the pharmacological actions of these three major phenolic antidiarrheic ingredients on the cellular viability in cultured astrocytes and neurons of the rat brain in vitro. Both 2M4MP and 2M4EP induced more efficient prevention of cell death induced by the brief exposure to 0.1 mM H(2)O(2) for 2 h than 2MP upon simultaneous exposure in cultured rat cortical astrocytes. Similarly, both 2M4MP and 2M4EP were more effective than 2MP in significantly protecting the cytotoxicity by brief exposure to 0.1 mM H(2)O(2) for 6 h in cultured rat hippocampal neurons, with concomitant suppression of the generation of intracellular reactive oxygen species in neurons exposed to H(2)O(2). Moreover, the three ingredients not only significantly prevented cell death in hippocampal neurons exposed to 0.1 mM glutamate for 1 h when determined 48 h after the brief exposure, but also inhibited the generation of intracellular reactive oxygen species and the elevation of intracellular Ca(2+) ions in neurons exposed to glutamate. These results suggest that particular phenolic antidiarrheic ingredients may prevent cell death through a mechanism related to diminution of the neurotoxicity of glutamate in neurons, in addition to eliciting cytoprotection against oxidative stress in astrocytes and neurons, in the rat brain.
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Affiliation(s)
- Nobuyuki Matsushima
- Laboratory of Molecular Pharmacology, Division of Pharmaceutical Sciences, Kanazawa University Graduate School of Natural Science and Technology, Kanazawa, Ishikawa 920-1192, Japan
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Goto Y, Taniura H, Yamada K, Hirai T, Sanada N, Nakamichi N, Yoneda Y. The magnetism responsive gene Ntan1 in mouse brain. Neurochem Int 2006; 49:334-41. [PMID: 16600435 DOI: 10.1016/j.neuint.2006.02.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2005] [Revised: 02/20/2006] [Accepted: 02/27/2006] [Indexed: 11/30/2022]
Abstract
We have previously identified Ntan1 as a magnetism response gene by differential display screening in cultured rat hippocampal neurons. Ntan1 mRNA was ubiquitously expressed in all the mouse tissues examined but relatively abundant in brain, retina and testis. Ntan1 mRNA expression was detectable in the embryonic 12-day mouse brain and gradually increased with ageing. In situ hybridization analysis showed high localization of Ntan1 mRNA in pyramidal cell layer of CA region and granular cell layer of dentate gyrus in the hippocampus, and Purkinje and granular cell layers in the cerebellum, respectively. Ntan1 mRNA expression was significantly increased about two-fold 12 h after brief exposure for 15 min to magnetism at 100 mT with a gradual decrease thereafter in cultured mouse hippocampal neurons. When embryonic 12-day-old or newborn mice were successively exposed to magnetic fields at 100 mT for 2 h, four times per day until the postnatal seventh day, Ntan1 mRNA was significantly increased about 1.5-2-fold in the hippocampus in vivo. The mice exposed to magnetic fields under the same condition showed significantly decreased locomotor activity. These results suggest that magnetic exposure affects higher order neural functions through modulation of genes expression.
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Affiliation(s)
- Yasuaki Goto
- Laboratory of Molecular Pharmacology, Division of Pharmaceutical Sciences, Kanazawa University, Graduate School of Natural Science and Technology, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
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19
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Hirai T, Taniura H, Goto Y, Ogura M, Sng JCG, Yoneda Y. Stimulation of ubiquitin?proteasome pathway through the expression of amidohydrolase for N-terminal asparagine (Ntan1) in cultured rat hippocampal neurons exposed to static magnetism. J Neurochem 2006; 96:1519-30. [PMID: 16539681 DOI: 10.1111/j.1471-4159.2006.03655.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In order to elucidate mechanisms underlying modulation by static magnetism of the cellular functionality and/or integrity in the brain, we screened genes responsive to brief magnetism in cultured rat hippocampal neurons using differential display analysis. We have for the first time cloned and identified Ntan1 (amidohydrolase for N-terminal asparagine) as a magnetism responsive gene in rat brain. Ntan1 is an essential component of a protein degradation signal, which is a destabilizing N-terminal residue of a protein, in the N-end rule. In situ hybridization histochemistry revealed abundant expression of Ntan1 mRNA in hippocampal neurons in vivo. Northern blot analysis showed that Ntan1 mRNA was increased about three-fold after 3 h in response to brief magnetism. Brief magnetism also increased the transcriptional activity of Ntan1 promoter by luciferase reporter assay. Brief magnetism induced degradation of microtubule-associated protein 2 (MAP2) without affecting cell morphology and viability, which was prevented by a selective inhibitor of 26S proteasome in hippocampal neurons. Overexpression of Ntan1 using recombinant Ntan1 adenovirus vector resulted in a marked decrease in the MAP2 protein expression in hippocampal neurons. Our results suggest that brief magnetism leads to the induction of Ntan1 responsible for MAP2 protein degradation through ubiquitin-proteasome pathway in rat hippocampal neurons.
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Affiliation(s)
- Takao Hirai
- Laboratory of Molecular Pharmacology, Division of Pharmaceutical Sciences, Kanazawa University Graduate School of Natural Science and Technology, Kanazawa, Ishikawa, Japan
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Okano H, Ohkubo C. Effects of neck exposure to 5.5 mT static magnetic field on pharmacologically modulated blood pressure in conscious rabbits. Bioelectromagnetics 2005; 26:469-80. [PMID: 16108042 DOI: 10.1002/bem.20115] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Static magnetic fields (SMF) in the millitesla (mT) range have been reported to modulate microcirculatory hemodynamics and/or blood pressure (BP) under pharmacologically modified state in mammals. This study was designed to investigate the acute effects of local application of a SMF to neck or pelvic region under pharmacologically modulated BP; norepinephrine (NE)-induced hypertension as well as an L-type voltage-gated Ca(2+) channel blocker, nicardipine (NIC)-induced hypotension in conscious rabbits. Magnetic flux densities were up to 5.5 mT and the spatial magnetic gradient peaked in neck (carotid sinus baroreceptor) region at the level of approximately 0.06 mT/mm. The duration of exposure was 30 min (including 10 min of pretreatment) and the effects on BP were investigated up to 100 min postexposure. Baroreflex sensitivity (BRS) was estimated from invasive recordings of systolic BP and pulse interval. Neck exposure to 5.5 mT significantly attenuated the pharmacologically induced vasoconstriction or vasodilation, and subsequently suppressed the increase or decrease in BP compared with sham exposure. In contrast, pelvic exposure to 5.5 mT did not significantly antagonized NE-elevated BP or NIC-reduced BP. The neck exposure to 5.5 mT has a biphasic and restorative effect on vascular tone and BP acting to normalize the tone and BP. The neck exposure to 5.5 mT caused a significant increase in BRS in NE-elevated BP compared with sham exposure. The buffering effects of the SMF on increased hemodynamic variability under NE-induced high vascular tone and NIC-induced low vascular tone might be, in part, dependent on baroreflex pathways, which could modulate NE-mediated response in conjunction with Ca(2+) dynamics.
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Affiliation(s)
- Hideyuki Okano
- Department of Environmental Health, National Institute of Public Health, Saitama, Japan.
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Okano H, Ohkubo C. Exposure to a moderate intensity static magnetic field enhances the hypotensive effect of a calcium channel blocker in spontaneously hypertensive rats. Bioelectromagnetics 2005; 26:611-23. [PMID: 16189831 DOI: 10.1002/bem.20144] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We investigated the combined effects of a moderate intensity static magnetic field (SMF) and an L-type voltage-gated Ca(2+) channel blocker, nicardipine in stroke-resistant spontaneously hypertensive rats during the development of hypertension. Five-week-old male rats were exposed to SMF intensity up to 180 mT (B(max)) with a peak spatial gradient of 133 mT/mm for 14 weeks. Four experimental groups of 14 animals each were examined: (1) sham exposure with intraperitoneal (ip) saline injection (control); (2) SMF exposure with ip saline injection (SMF); (3) sham exposure with ip nicardipine injection (NIC); (4) SMF exposure with ip nicardipine injection (SMF + NIC). A disc-shaped permanent magnet or a dummy magnet was implanted in the vicinity adjacent to the left carotid sinus baroreceptor region in the neck of each rat. Nicardipine (2 mg/kg ip) was administered three times a week for 14 weeks, and then 15 min after each injection, arterial blood pressure (BP), heart rate (HR), baroreflex sensitivity (BRS), skin blood flow (SBF), skin blood velocity (SBV), plasma nitric oxide (NO) metabolites (NO(x) = NO(2) (-) + NO(3) (-)), plasma catecholamine levels and behavioral parameters of a functional observational battery were monitored. The action of nicardipine significantly decreased BP, and increased HR, SBF, SBV, plasma epinephrine and norepinephrine in the NIC group compared with the control respective age-matched group without changing plasma NO(x) levels. Neck exposure to SMF alone for 5-8 weeks significantly suppressed or retarded the development of hypertension together with increased BRS in SMF group. Furthermore, the exposure to SMF for 1-8 weeks significantly promoted the nicardipine-induced BP decrease in the SMF + NIC group compared with the respective NIC group. Moreover, the SMF induced a significant increase in plasma NO(x) in the nicardipine-induced hypotension. There were no significant differences in any of the physiological or behavioral parameters measured between the SMF + NIC and the NIC groups, nor between the SMF and the control groups. These results suggest that the SMF may enhance nicardipine-induced hypotension by more effectively antagonizing the Ca(2+) influx through the Ca(2+) channels compared with the NIC treatment alone. Furthermore, the enhanced antihypertensive effects of the SMF on the nicardipine-treated group appear to be partially related to the increased NO(x). Theoretical considerations suggest that the applied SMF (B(max) 40 mT, 0 Hz) can be converted into a changing magnetic field (B(max) 30-40 mT, 5.7-6.5 Hz or 7.5-8.3 Hz) in the baroreceptor region by means of the carotid artery pulsation. Therefore, we propose that the moderate intensity changing magnetic field, i.e., the magnetic field modulated by the pulse rate, may influence the activity of baroreceptor and baroreflex function.
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Affiliation(s)
- Hideyuki Okano
- Department of Environmental Health, National Institute of Public Health, Saitama, Japan.
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