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Kennedy KAM, Ostrakhovitch EA, Sandiford SDE, Dayarathna T, Xie X, Waese EYL, Chang WY, Feng Q, Skerjanc IS, Stanford WL, Li SSC. Mammalian numb-interacting protein 1/dual oxidase maturation factor 1 directs neuronal fate in stem cells. J Biol Chem 2010; 285:17974-85. [PMID: 20233719 PMCID: PMC2878559 DOI: 10.1074/jbc.m109.084616] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2009] [Revised: 03/08/2010] [Indexed: 01/11/2023] Open
Abstract
In this study, we describe a role for the mammalian Numb-interacting protein 1 (Nip1) in regulation of neuronal differentiation in stem cells. The expression of Nip1 was detected in the developing mouse brain, embryonic stem cells, primary neuronal stem cells, and retinoic acid-treated P19 embryonal carcinoma cells. The highest expression of Nip1 was observed in undifferentiated neuronal stem cells and was associated with Duox1-mediated reactive oxygen species ROS production. Ectopic nip1 expression in P19 embryonal carcinoma cells induced neuronal differentiation, and this phenotype was also linked to elevated ROS production. The neuronal differentiation in nip1-overexpressing P19 cells was achieved in a retinoic acid-independent manner and was corroborated by an increase in the expression of the neuronal basic helix-loop-helix transcription factors and neural-lineage cell markers. Furthermore, depletion of nip1 by short hairpin RNA led to a decrease in the expression of neuronal basic helix-loop-helix transcription factors and ROS. However, inhibition of ROS production in nip1-overexpressing P19 cells restricted but did not extinguish neuronal differentiation. Microarray and mass spectrometry analysis identified intermediate filaments as the principal cytoskeletal elements affected by up-regulation of nip1. We show here the first evidence for a functional interaction between Nip1 and a component of the nuclear lamina, lamin A/C. associated with a neuronal-specific phenotype. Taken together, our data reveal an important role for Nip1 in the guidance of neuronal differentiation through ROS generation and modulation of intermediate filaments and implicate Nip1 as a novel intrinsic regulator of neuronal cell fate.
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Affiliation(s)
- Karen A. M. Kennedy
- From the Department of Biochemistry, Siebens-Drake Medical Research Institute, Schulich School of Medicine and Dentistry and
| | - Elena A. Ostrakhovitch
- From the Department of Biochemistry, Siebens-Drake Medical Research Institute, Schulich School of Medicine and Dentistry and
| | - Shelley D. E. Sandiford
- From the Department of Biochemistry, Siebens-Drake Medical Research Institute, Schulich School of Medicine and Dentistry and
| | - Thamara Dayarathna
- From the Department of Biochemistry, Siebens-Drake Medical Research Institute, Schulich School of Medicine and Dentistry and
| | - Xiaojun Xie
- From the Department of Biochemistry, Siebens-Drake Medical Research Institute, Schulich School of Medicine and Dentistry and
| | - Elaine Y. L. Waese
- the Department of Chemical Engineering and Applied Chemistry and
- the Departments of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Wing Y. Chang
- the Institute of Biomaterials and Biomedical Engineering, University of Toronto, Ontario M5S 3G9, Canada, and
| | - Qingping Feng
- the Department of Physiology and Pharmacology, the University of Western Ontario, London, Ontario N6A 5C1, Canada
| | - Ilona S. Skerjanc
- From the Department of Biochemistry, Siebens-Drake Medical Research Institute, Schulich School of Medicine and Dentistry and
- the Departments of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - William L. Stanford
- the Department of Chemical Engineering and Applied Chemistry and
- the Institute of Biomaterials and Biomedical Engineering, University of Toronto, Ontario M5S 3G9, Canada, and
| | - Shawn S. C. Li
- From the Department of Biochemistry, Siebens-Drake Medical Research Institute, Schulich School of Medicine and Dentistry and
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102
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Ji G, Neugebauer V. Reactive oxygen species are involved in group I mGluR-mediated facilitation of nociceptive processing in amygdala neurons. J Neurophysiol 2010; 104:218-29. [PMID: 20463194 DOI: 10.1152/jn.00223.2010] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Recent biochemical and behavioral data implicate reactive oxygen species (ROS) in peripheral and spinal pain mechanisms. However, pain-related functions of ROS in the brain and mechanisms of pain-related ROS activation remain to be determined. Our previous studies showed that the amygdala plays a key role in emotional-affective pain responses and pain modulation. Hyperactivity of amygdala neurons in an animal pain model depends on group I metabotropic glutamate receptors (subtypes mGluR1 and mGluR5), but their signaling pathway remains to be determined. Here we tested the hypothesis that activation of group I mGluRs increases nociceptive processing in amygdala neurons through a mechanism that involves ROS. Extracellular single-unit recordings were made from neurons in the laterocapsular division of the central nucleus of the amygdala (CeLC) in anesthetized adult male rats. Administration of a group I mGluR agonist (DHPG) into the CeLC by microdialysis increased the responses to innocuous and noxious somatosensory (knee joint compression) and visceral (colorectal distention [CRD]) stimuli. A ROS scavenger (PBN) and a superoxide dismutase mimetic (TEMPOL) reversed the facilitatory effects of DHPG. An mGluR5 antagonist (MPEP) also inhibited the effects of DHPG on the responses to innocuous and noxious somatosensory and visceral stimuli, whereas an mGluR1 antagonist (LY367385) decreased only the responses to visceral stimulation. The results show for the first time that ROS mediate group I mGluR-induced facilitation of nociceptive processing in amygdala neurons. The antagonist data may suggest differential contributions of subtypes mGluR1 and mGluR5 to the processing of somatosensory and visceral nociceptive information in the amygdala.
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Affiliation(s)
- Guangchen Ji
- Department of Neuroscience and Cell Biology, The University of Texas Medical Branch, Galveston, Texas 77555-1069, USA
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103
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Oral phycocyanobilin may diminish the pathogenicity of activated brain microglia in neurodegenerative disorders. Med Hypotheses 2010; 74:601-5. [DOI: 10.1016/j.mehy.2008.09.061] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2008] [Revised: 09/12/2008] [Accepted: 09/27/2008] [Indexed: 01/08/2023]
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104
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Picture representation during REM dreams: a redox molecular hypothesis. Biosystems 2010; 100:79-86. [PMID: 20132862 DOI: 10.1016/j.biosystems.2010.01.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2009] [Revised: 11/20/2009] [Accepted: 01/23/2010] [Indexed: 12/19/2022]
Abstract
A novel molecular hypothesis about visual perception and imagery has recently been proposed (Bókkon, 2009; BioSystems). Namely, external electromagnetic visible photons are converted into electrical signals in the retina and are then conveyed to V1. Next, these retinotopic electrical signals (spike-related electrical signals along classical axonal-dendritic pathways) can be converted into synchronized bioluminescent biophoton signals (inside the neurons) by neurocellular radical reactions (redox processes) in retinotopically organized V1 mitochondrial cytochrome oxidase-rich visual areas. The bioluminescent photonic signals (inside the neurons) generated by neurocellular redox/radical reactions in synchronized V1 neurons make it possible to produce computational biophysical pictures during visual perception and imagery. Our hypothesis is in line with the functional roles of reactive oxygen and nitrogen species in living cells and states that this is not a random process, but rather a strict mechanism used in signaling pathways. Here, we suggest that intrinsic biophysical pictures can also emerge during REM dreams.
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105
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106
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Potter WB, O'Riordan KJ, Barnett D, Osting SMK, Wagoner M, Burger C, Roopra A. Metabolic regulation of neuronal plasticity by the energy sensor AMPK. PLoS One 2010; 5:e8996. [PMID: 20126541 PMCID: PMC2813866 DOI: 10.1371/journal.pone.0008996] [Citation(s) in RCA: 134] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2009] [Accepted: 01/07/2010] [Indexed: 12/15/2022] Open
Abstract
Long Term Potentiation (LTP) is a leading candidate mechanism for learning and memory and is also thought to play a role in the progression of seizures to intractable epilepsy. Maintenance of LTP requires RNA transcription, protein translation and signaling through the mammalian Target of Rapamycin (mTOR) pathway. In peripheral tissue, the energy sensor AMP-activated Protein Kinase (AMPK) negatively regulates the mTOR cascade upon glycolytic inhibition and cellular energy stress. We recently demonstrated that the glycolytic inhibitor 2-deoxy-D-glucose (2DG) alters plasticity to retard epileptogenesis in the kindling model of epilepsy. Reduced kindling progression was associated with increased recruitment of the nuclear metabolic sensor CtBP to NRSF at the BDNF promoter. Given that energy metabolism controls mTOR through AMPK in peripheral tissue and the role of mTOR in LTP in neurons, we asked whether energy metabolism and AMPK control LTP. Using a combination of biochemical approaches and field-recordings in mouse hippocampal slices, we show that the master regulator of energy homeostasis, AMPK couples energy metabolism to LTP expression. Administration of the glycolytic inhibitor 2-deoxy-D-glucose (2DG) or the mitochondrial toxin and anti-Type II Diabetes drug, metformin, or AMP mimetic AICAR results in activation of AMPK, repression of the mTOR pathway and prevents maintenance of Late-Phase LTP (L-LTP). Inhibition of AMPK by either compound-C or the ATP mimetic ara-A rescues the suppression of L-LTP by energy stress. We also show that enhanced LTP via AMPK inhibition requires mTOR signaling. These results directly link energy metabolism to plasticity in the mammalian brain and demonstrate that AMPK is a modulator of LTP. Our work opens up the possibility of using modulators of energy metabolism to control neuronal plasticity in diseases and conditions of aberrant plasticity such as epilepsy.
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Affiliation(s)
- Wyatt B. Potter
- Department of Neurology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Kenneth J. O'Riordan
- Department of Neurology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - David Barnett
- Department of Neurology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Susan M. K. Osting
- Department of Neurology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Matthew Wagoner
- Department of Neurology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Corinna Burger
- Department of Neurology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Avtar Roopra
- Department of Neurology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- * E-mail:
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107
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Kumakura K, Nomura H, Toyoda T, Hashikawa K, Noguchi T, Takeda K, Ichijo H, Tsunoda M, Funatsu T, Ikegami D, Narita M, Suzuki T, Matsuki N. Hyperactivity in novel environment with increased dopamine and impaired novelty preference in apoptosis signal-regulating kinase 1 (ASK1)-deficient mice. Neurosci Res 2009; 66:313-20. [PMID: 20006657 DOI: 10.1016/j.neures.2009.12.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2009] [Revised: 11/29/2009] [Accepted: 12/01/2009] [Indexed: 11/26/2022]
Abstract
Apoptosis signal-regulating kinase 1 (ASK1) is a mitogen-activated protein (MAP) kinase kinase kinase family member, which induces apoptosis in various cells through JNK and p38 MAP kinase cascades. In addition to apoptosis signaling, a number of recent in vitro studies have suggested that ASK1 may play roles in neural function. However, the behavioral significance of ASK1 has remained unclear. Here, we subjected ASK1 (-/-) mice to a battery of behavioral tests and found that they displayed temporary hyperactivity in an open-field test. Activities in the familiar field were normal, indicating that the hyperactivity observed was specific to the novel environment. ASK1 (-/-) mice also exhibited impairment of novelty preference 24h after training and superior performance on the rotarod test. Brain tissue contents of dopamine and 4-dihydroxyphenylacetic acid (DOPAC) were elevated in ASK1 (-/-) mice. Our findings thus demonstrate novel behavioral functions of ASK1, including regulation of locomotor activity, novelty preference, and motor coordination with dopaminergic transmission.
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Affiliation(s)
- Karen Kumakura
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
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108
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Betzen C, White R, Zehendner CM, Pietrowski E, Bender B, Luhmann HJ, Kuhlmann CRW. Oxidative stress upregulates the NMDA receptor on cerebrovascular endothelium. Free Radic Biol Med 2009; 47:1212-20. [PMID: 19660541 DOI: 10.1016/j.freeradbiomed.2009.07.034] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Revised: 07/14/2009] [Accepted: 07/30/2009] [Indexed: 12/01/2022]
Abstract
N-methyl-d-aspartate receptor (NMDA-R)-mediated oxidative stress has been implicated in blood-brain barrier (BBB) disruption in a variety of neuropathological diseases. Although some interactions between both phenomena have been elucidated, possible influences of reactive oxygen species (ROS) on the NMDA-R itself have so far been neglected. The objective of this study was to examine how the cerebroendothelial NMDA-R is affected by exposure to oxidative stress and to assess possible influences on BBB integrity. RT-PCR confirmed several NMDA-R subunits (NR1, NR2B-D) expressed in the bEnd3 cell line (murine cerebrovascular endothelial cells). NR1 protein expression after exposure to ROS was observed via in-cell Western. The functionality of the expressed NMDA-R was determined by measuring DiBAC fluorescence in ROS-preexposed cells upon stimulation with the specific agonist NMDA. Finally, the effects on barrier integrity were evaluated using the ECIS system to detect changes in monolayer impedance upon NMDA-R stimulation after exposure to ROS. The expression of NR1 significantly (p<0.001) increased 72 h after 30 min exposure to superoxide (+33.8+/-7.5%), peroxynitrite (+84.9+/-10.7%), or hydrogen peroxide (+92.8+/-7.6%), resulting in increased cellular response to NMDA-R stimulation and diminished monolayer impedance. We conclude that oxidative stress upregulates NMDA-R on cerebrovascular endothelium and thus heightens susceptibility to glutamate-induced BBB disruption.
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Affiliation(s)
- Christian Betzen
- Institute of Physiology and Pathophysiology, Universitätsmedizin, Johannes Gutenberg-University of Mainz, 55128 Mainz, Germany
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109
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Reactive oxygen species potentiate the P2X2 receptor activity through intracellular Cys430. J Neurosci 2009; 29:12284-91. [PMID: 19793987 DOI: 10.1523/jneurosci.2096-09.2009] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
P2X receptor channels (P2XRs) are allosterically modulated by several compounds, mainly acting at the ectodomain of the receptor. Like copper, mercury, a metal that induces oxidative stress in cells, also stimulates the activity of P2X(2)R and inhibits the activity of P2X(4)R. However, the mercury modulation is not related to the extracellular residues critical for copper modulation. To identify the site(s) for mercury action, we generated two chimeras using the full size P2X(2) subunit, termed P2X(2a), and a splice variant lacking a 69 residue segment in the C terminal, termed P2X(2b), as the donors for intracellular and transmembrane segments and the P2X(4) subunit as the donor for ectodomain segment of chimeras. The potentiating effect of mercury on ATP-induced current was preserved in Xenopus oocytes expressing P2X(4/2a) chimera but was absent in oocytes expressing P2X(4/2b) chimera. Site-directed mutagenesis experiments revealed that the Cys(430) residue mediates effects of mercury on the P2X(2a)R activity. Because mercury could act as an oxidative stress inducer, we also tested whether hydrogen peroxide (H(2)O(2)) and mitochondrial stress inducers myxothiazol and rotenone mimicked mercury effects. These experiments, done in both oocytes and human embryonic kidney HEK293 cells, revealed that these compounds potentiated the ATP-evoked P2X(2a)R and P2X(4/2a)R currents but not P2X(2b)R and P2X(2a)-C430A and P2X(2a)-C430S mutant currents, whereas antioxidants dithiothreitrol and N-acetylcysteine prevented the H(2)O(2) potentiation. Alkylation of Cys(430) residue with methylmethane-thiosulfonate also abolished the mercury and H(2)O(2) potentiation. Altogether, these results are consistent with the hypothesis that the Cys(430) residue is an intracellular P2X(2a)R redox sensor.
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110
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Bókkon I, Vimal RLP. Retinal phosphenes and discrete dark noises in rods: A new biophysical framework. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2009; 96:255-9. [DOI: 10.1016/j.jphotobiol.2009.07.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2009] [Revised: 06/28/2009] [Accepted: 07/02/2009] [Indexed: 10/20/2022]
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111
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Bell JD, Park E, Ai J, Baker AJ. PICK1-mediated GluR2 endocytosis contributes to cellular injury after neuronal trauma. Cell Death Differ 2009; 16:1665-80. [DOI: 10.1038/cdd.2009.106] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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112
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Kim SU, Jin MH, Kim YS, Lee SH, Cho YS, Cho KJ, Lee KS, Kim YI, Kim GW, Kim JM, Lee TH, Lee YH, Shong M, Kim HC, Chang KT, Yu DY, Lee DS. Peroxiredoxin II preserves cognitive function against age-linked hippocampal oxidative damage. Neurobiol Aging 2009; 32:1054-68. [PMID: 19577336 DOI: 10.1016/j.neurobiolaging.2009.05.017] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2008] [Revised: 05/19/2009] [Accepted: 05/27/2009] [Indexed: 01/31/2023]
Abstract
Reactive oxygen species (ROS), routinely produced in biological reactions, contribute to both normal aging and age-related decline in cognitive function. However, little is known regarding the involvement of specific antioxidants in the underlying mechanism(s). Here, we examined if peroxiredoxin II (Prx II) scavenges intracellular ROS that cause age-dependent mitochondrial decay in hippocampal CA1 pyramidal neurons and subsequent impairment of learning and memory. Age-dependent mitochondrial ROS generation and long-term potentiation (LTP) decline were more prominent in hippocampal neurons in Prx II(-/-) than in wild-type mice. Additionally, Prx II(-/-) mice failed to activate synaptic plasticity-related cellular signaling pathways involving CREB, CaMKII, and ERK, or to maintain functional integrity of their mitochondria. Dietary vitamin E alleviated Prx II deficiency-related deficits, including mitochondrial decay and CREB signaling, resulting in restoration of the abrupt cognitive decline in aged Prx II(-/-) mice. These results suggest that Prx II help maintain hippocampal synaptic plasticity against age-related oxidative damage.
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Affiliation(s)
- Sun-Uk Kim
- Aging Science Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 305-806, Republic of Korea
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113
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Bókkon I. Visual perception and imagery: A new molecular hypothesis. Biosystems 2009; 96:178-84. [DOI: 10.1016/j.biosystems.2009.01.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2008] [Revised: 01/25/2009] [Accepted: 01/25/2009] [Indexed: 12/01/2022]
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114
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MacFarlane PM, Wilkerson JER, Lovett-Barr MR, Mitchell GS. Reactive oxygen species and respiratory plasticity following intermittent hypoxia. Respir Physiol Neurobiol 2009; 164:263-71. [PMID: 18692605 DOI: 10.1016/j.resp.2008.07.008] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2008] [Revised: 07/13/2008] [Accepted: 07/15/2008] [Indexed: 11/18/2022]
Abstract
The neural network controlling breathing exhibits plasticity in response to environmental or physiological challenges. For example, while hypoxia initiates rapid and robust increases in respiratory motor output to defend against hypoxemia, it also triggers persistent changes, or plasticity, in chemosensory neurons and integrative pathways that transmit brainstem respiratory activity to respiratory motor neurons. Frequently studied models of hypoxia-induced respiratory plasticity include: (1) carotid chemosensory plasticity and metaplasticity induced by chronic intermittent hypoxia (CIH), and (2) acute intermittent hypoxia (AIH) induced phrenic long-term facilitation (pLTF) in naïve and CIH preconditioned rats. These forms of plasticity share some mechanistic elements, although they differ in anatomical location and the requirement for CIH preconditioning. Both forms of plasticity require serotonin receptor activation and formation of reactive oxygen species (ROS). While the cellular sources and targets of ROS are not well known, recent evidence suggests that ROS modify the balance of protein phosphatase and kinase activities, shifting the balance towards net phosphorylation and favoring cellular reactions that induce and/or maintain plasticity. Here, we review possible sources of ROS, and the impact of ROS on phosphorylation events relevant to respiratory plasticity.
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Affiliation(s)
- P M MacFarlane
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin, 2015 Linden Drive, Madison, WI 53706, USA.
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115
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Maalouf M, Rho JM. Oxidative impairment of hippocampal long-term potentiation involves activation of protein phosphatase 2A and is prevented by ketone bodies. J Neurosci Res 2009; 86:3322-30. [PMID: 18646208 DOI: 10.1002/jnr.21782] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Previous studies have shown that ketone bodies (KB) exert antioxidant effects in experimental models of neurological disease. In the present study, we explored the effects of the KB acetoacetate (ACA) and beta-hydroxybutyrate (BHB) on impairment of hippocampal long-term potentiation (LTP) in rats by hydrogen peroxide (H(2)O(2)) using electrophysiological, fluorescence imaging, and enzyme assay techniques. We found that: 1) a combination of ACA and BHB (1 mM each) prevented impairment of LTP by H(2)O(2) (200 microM); 2) KB significantly lowered intracellular levels of reactive oxygen species (ROS)--measured with the fluorescent indicator carboxy-H(2)DCFDA (carboxy-2',7'-dichlorodihydrofluorescein diacetate)--in CA1 pyramidal neurons exposed to H(2)O(2); 3) the effect of KB on LTP was replicated by the protein phosphatase 2A (PP2A) inhibitor fostriecin; 4) KB prevented impairment of LTP by the PP2A activator C(6) ceramide; 5) fostriecin did not prevent the increase in ROS levels in CA1 pyramidal neurons exposed to H(2)O(2), and C(6) ceramide did not increase ROS levels; 6) PP2A activity was enhanced by both H(2)O(2) and rotenone (a mitochondrial complex I inhibitor that increases endogenous superoxide production); and 7) KB inhibited PP2A activity in protein extracts from brain tissue treated with either H(2)O(2) or ceramide. We propose that oxidative impairment of hippocampal LTP is associated with PP2A activation, and that KB prevent this impairment in part by inducing PP2A inhibition through an antioxidant mechanism.
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Affiliation(s)
- Marwan Maalouf
- Division of Neurology, Cedars Sinai Medical Center, Los Angeles, California, USA
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116
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Bókkon I, D’Angiulli A. Emergence and transmission of visual awareness through optical coding in the brain: A redox molecular hypothesis on visual mental imagery. ACTA ACUST UNITED AC 2009. [DOI: 10.1016/j.bihy.2009.01.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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117
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Munnamalai V, Suter DM. Reactive oxygen species regulate F-actin dynamics in neuronal growth cones and neurite outgrowth. J Neurochem 2008; 108:644-61. [PMID: 19054285 DOI: 10.1111/j.1471-4159.2008.05787.x] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Reactive oxygen species are well known for their damaging effects due to oxidation of lipids, proteins and DNA that ultimately result in cell death. Accumulating evidence indicates that reactive oxygen species also have important signaling functions in cell proliferation, differentiation, cell motility and apoptosis. Here, we tested the hypothesis whether reactive oxygen species play a physiological role in regulating F-actin structure and dynamics in neuronal growth cones. Lowering cytoplasmic levels of reactive oxygen species with a free radical scavenger, N-tert-butyl-alpha-phenylnitrone, or by inhibiting specific sources of reactive oxygen species, such as NADPH oxidases or lipoxygenases, reduced the F-actin content in the peripheral domain of growth cones. Fluorescent speckle microscopy revealed that these treatments caused actin assembly inhibition, reduced retrograde actin flow and increased contractility of actin structures in the transition zone referred to as arcs, possibly by activating the Rho pathway. Reduced levels of reactive oxygen species ultimately resulted in disassembly of the actin cytoskeleton. When neurons were cultured overnight in conditions of reduced free radicals, growth cone formation and neurite outgrowth were severely impaired. Therefore, we conclude that physiological levels of reactive oxygen species are critical for maintaining a dynamic F-actin cytoskeleton and controlling neurite outgrowth.
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Affiliation(s)
- Vidhya Munnamalai
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907-2054, USA
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118
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Coyoy A, Valencia A, Guemez-Gamboa A, Morán J. Role of NADPH oxidase in the apoptotic death of cultured cerebellar granule neurons. Free Radic Biol Med 2008; 45:1056-64. [PMID: 18675340 DOI: 10.1016/j.freeradbiomed.2008.06.027] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2008] [Revised: 06/11/2008] [Accepted: 06/13/2008] [Indexed: 12/15/2022]
Abstract
Cerebellar granule neurons (CGN) cultured in a medium containing 25 mM KCl and treated with staurosporine (ST) or transferred to a medium with 5 mM KCl (K5) die apoptotically. CGN death is mediated by an increase in reactive oxygen species (ROS) production. When CGN are treated with antioxidants all apoptotic parameters and cell death are markedly diminished, showing a central role for ROS in this process. Recently, it has been suggested that a possible ROS source involved in cell death is a NADPH oxidase. In that regard, we found expression in CGN of the components of NADPH proteins, p40phox, p47phox and p67phox, and p22phox, as well as three homologues of the catalytic subunit of this complex, NOX1, 2, and 4. The inhibition of NADPH oxidase with diphenylene iodonium or 4-(2-aminoethyl)benzenesulfonyl fluoride significantly reduced ROS production, NADPH oxidase activity, all the apoptotic events, and cell death induced by both K5 and ST. We conclude that ROS could be an early signal of apoptotic neuronal death and that NADPH oxidase, including NOX1, 2, and/or 4, could have a central role in apoptotic death induced by different conditions in these neurons.
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Affiliation(s)
- Angélica Coyoy
- Departamento de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, 04510 México, DF, México
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119
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Opposite effects of alpha-lipoic acid on antioxidation and long-term potentiation in control and chronically lead-exposed rats. Naunyn Schmiedebergs Arch Pharmacol 2008; 378:303-10. [PMID: 18504555 DOI: 10.1007/s00210-008-0307-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2008] [Accepted: 04/29/2008] [Indexed: 12/12/2022]
Abstract
Among the developmental changes identified in rats exposed to lead are impairments in long-term potentiation (LTP) in the hippocampus and changes in the levels of reactive oxygen species (ROS) in cells and some soft tissues. alpha-Lipoic acid (LA) has been reported to be highly effective in improving the thiol capacity of the cells and in reducing lead-induced oxidative stress. To explore the effects of LA on LTP in chronically lead-exposed rats and the relationship between ROS and LTP in both control and lead-exposed rats, we have compared LTP and oxidative stress parameters in groups of lead-exposed and control rats with or without LA treatment (10, 25, 50, and 100 mg/kg through intraperitoneal injection). The capacity of LA to decrease hippocampal lead levels in lead-exposed rats was examined. We found that LA had no effects in decreasing the level of lead in the hippocampus, but it did appear to have both antioxidant properties and a reparatory effect on LTP amplitude in rats developmentally exposed to lead for 2 weeks following birth. Interestingly, bell-shaped dose-response curves emerged. In the lower LA dosage groups (10, 25 mg/kg LA), there was an increasing LTP amplitude. The strongest protective effect in terms of the induction and amplitude of LTP in the lead-exposed group with at 25 mg/kg LA; when higher dosages were applied (50, 100 mg/kg LA), the LTP amplitude decreased as compared to the 25 mg/kg LA treatment group. The administration of LA to control animals resulted in a significant impairment of LTP amplitude, with the 100 mg/kg LA treatment having harmful effects on the oxidative parameters. These differential effects of LA on LTP in control and lead-exposed rats may be due to the different redox status of the control and lead-exposed rats.
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120
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Farr SA, Yamada KA, Butterfield DA, Abdul HM, Xu L, Miller NE, Banks WA, Morley JE. Obesity and hypertriglyceridemia produce cognitive impairment. Endocrinology 2008; 149:2628-36. [PMID: 18276751 PMCID: PMC2329289 DOI: 10.1210/en.2007-1722] [Citation(s) in RCA: 273] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Obesity is associated with cognitive impairments. Long-term mechanisms for this association include consequences of hyperglycemia, dyslipidemia, or other factors comprising metabolic syndrome X. We found that hypertriglyceridemia, the main dyslipidemia of metabolic syndrome X, is in part responsible for the leptin resistance seen in obesity. Here we determined whether triglycerides have an immediate and direct effect on cognition. Obese mice showed impaired acquisition in three different cognitive paradigms: the active avoidance T-maze, the Morris water maze, and a food reward lever press. These impairments were not attributable to differences in foot shock sensitivity, swim speed, swimming distance, or voluntary milk consumption. Impaired cognition in obese mice was improved by selectively lowering triglycerides with gemfibrozil. Injection into the brain of the triglyceride triolein, but not of the free fatty acid palmitate, impaired acquisition in normal body weight mice. Triolein or milk (97% of fats are triglycerides), but not skim milk (no triglycerides), impaired maintenance of the N-methyl-d-aspartate component of the hippocampal long-term synaptic potential. Measures of oxidative stress in whole brain were reduced by gemfibrozil. We conclude that triglycerides mediate cognitive impairment as seen in obesity, possibly by impairing maintenance of the N-methyl-d-aspartate component of hippocampal long-term potentiation, and that lowering triglycerides can reverse the cognitive impairment and improve oxidative stress in the brain.
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Affiliation(s)
- Susan A Farr
- Division of Geriatric Medicine, Saint Louis University School of Medicine, St. Louis, Missouri 63104, USA
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121
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Okadaic acid-sensitive protein phosphatases constrain phrenic long-term facilitation after sustained hypoxia. J Neurosci 2008; 28:2949-58. [PMID: 18337426 DOI: 10.1523/jneurosci.5539-07.2008] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Phrenic long-term facilitation (pLTF) is a serotonin-dependent form of pattern-sensitive respiratory plasticity induced by intermittent hypoxia (IH), but not sustained hypoxia (SH). The mechanism(s) underlying pLTF pattern sensitivity are unknown. SH and IH may differentially regulate serine/threonine protein phosphatase activity, thereby inhibiting relevant protein phosphatases uniquely during IH and conferring pattern sensitivity to pLTF. We hypothesized that spinal protein phosphatase inhibition would relieve this braking action of protein phosphatases, thereby revealing pLTF after SH. Anesthetized rats received intrathecal (C4) okadaic acid (25 nm) before SH (25 min, 11% O(2)). Unlike (vehicle) control rats, SH induced a significant pLTF in okadaic acid-treated rats that was indistinguishable from rats exposed to IH (three 5 min episodes, 11% O(2)). IH and SH with okadaic acid may elicit pLTF by similar, serotonin-dependent mechanisms, because intravenous methysergide blocks pLTF in rats receiving IH or okadaic acid plus SH. Okadaic acid did not alter IH-induced pLTF. In summary, pattern sensitivity in pLTF may reflect differential regulation of okadaic acid-sensitive serine/threonine phosphatases; presumably, these phosphatases are less active during/after IH versus SH. The specific okadaic acid-sensitive phosphatase(s) constraining pLTF and their spatiotemporal dynamics during and/or after IH and SH remain to be determined.
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122
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Bókkon I. Phosphene phenomenon: a new concept. Biosystems 2008; 92:168-74. [PMID: 18358594 DOI: 10.1016/j.biosystems.2008.02.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2007] [Revised: 02/10/2008] [Accepted: 02/12/2008] [Indexed: 02/01/2023]
Abstract
This paper proposes a new biopsychophysical concept of phosphene phenomenon. Namely, visual sensation of phosphenes is due to the intrinsic perception of ultraweak bioluminescent photon emission of cells in the visual system. In other words, phosphenes are bioluminescent biophotons in the visual system induced by various stimuli (mechanical, electrical, magnetic, ionizing radiation, etc.) as well as random bioluminescent biophotons firings of cells in the visual pathway. This biophoton emission can become conscious if induced or spontaneous biophoton emission of cells in the visual system exceeds a distinct threshold. Neuronal biophoton communication can occur by means of non-visual neuronal opsins and natural photosensitive biomolecules. Our interpretation is in direct connection with the functional roles of free radicals and excited biomolecules in living cells.
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Affiliation(s)
- István Bókkon
- PhD School in Pharmacology, Semmelweis University, Láng E. 68, H-1238 Budapest, Hungary.
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123
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Respiratory plasticity following intermittent hypoxia: roles of protein phosphatases and reactive oxygen species. Biochem Soc Trans 2008; 35:1269-72. [PMID: 17956327 DOI: 10.1042/bst0351269] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Plasticity is an important property of the respiratory control system. One of the best-studied models of respiratory plasticity is pLTF (phrenic long-term facilitation). pLTF is a progressive increase in phrenic motor output lasting several hours following acute exposure to intermittent hypoxia. Similar to many other forms of neuroplasticity, pLTF is pattern-sensitive; it is induced by intermittent, but not sustained hypoxia of similar cumulative duration. Our understanding of the cellular/synaptic mechanisms underlying pLTF has increased considerably in recent years. Here, we review accumulating evidence suggesting that the pattern-sensitivity of pLTF arises substantially from differential reactive oxygen species formation and subsequent protein phosphatase inhibition during intermittent compared with sustained hypoxia in or near phrenic motor neurons. A detailed understanding of the cellular/synaptic mechanisms of pLTF may provide the rationale for new pharmacological approaches in the treatment of severe ventilatory control disorders, such as obstructive sleep apnoea and respiratory insufficiency either following spinal cord injury or during neurodegenerative diseases such as amyotrophic lateral sclerosis.
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Kim SU, Hwang CN, Sun HN, Jin MH, Han YH, Lee H, Kim JM, Kim SK, Yu DY, Lee DS, Lee SH. Peroxiredoxin I Is an Indicator of Microglia Activation and Protects against Hydrogen Peroxide-Mediated Microglial Death. Biol Pharm Bull 2008; 31:820-5. [DOI: 10.1248/bpb.31.820] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Sun-Uk Kim
- School of Life Sciences and Biotechnology, Korea University
- Disease Model Research Center, Biological Resource Center, KRIBB
| | | | - Hu-Nan Sun
- Disease Model Research Center, Biological Resource Center, KRIBB
- College of Veterinary Medicine, Chungnam National University
| | - Mei-Hua Jin
- Disease Model Research Center, Biological Resource Center, KRIBB
| | - Ying-Hao Han
- Disease Model Research Center, Biological Resource Center, KRIBB
| | - Hwang Lee
- School of Life Sciences and Biotechnology, Korea University
- National Veterinary Research and Quarantine Service
| | - Jin-Man Kim
- Department of Pathology, College of Medicine, Chungnam National University
| | - Sang-Keun Kim
- College of Veterinary Medicine, Chungnam National University
| | - Dae-Yeul Yu
- Disease Model Research Center, Biological Resource Center, KRIBB
| | - Dong-Seok Lee
- College of Natural Sciences, Kyungpook National University
| | - Sang Ho Lee
- School of Life Sciences and Biotechnology, Korea University
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125
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Song HG, Moon C, Park MH, Moon JI, Moon C. Decrease in Intracellular Glutathione Level Alters Expressions of B-cell CLL/Lymphoma 2 Family Members in the Mouse Retina. ACTA ACUST UNITED AC 2008. [DOI: 10.1248/jhs.54.464] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Hyoung-Gon Song
- Department of Emergency Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine
| | - Cheil Moon
- Department of Oral Anatomy and Neurobiology Kyungpook National University School of Dentistry
| | - Myoung-Hee Park
- Department of Ophthalmology, College of Medicine, The Catholic University of Korea
| | - Jung-Il Moon
- Department of Ophthalmology, College of Medicine, The Catholic University of Korea
| | - Chanil Moon
- Department of Cardiology, Gil Medical Center, Gachon University
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Di Loreto S, Zimmitti V, Sebastiani P, Cervelli C, Falone S, Amicarelli F. Methylglyoxal causes strong weakening of detoxifying capacity and apoptotic cell death in rat hippocampal neurons. Int J Biochem Cell Biol 2007; 40:245-57. [PMID: 17869161 DOI: 10.1016/j.biocel.2007.07.019] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2007] [Revised: 07/24/2007] [Accepted: 07/25/2007] [Indexed: 01/10/2023]
Abstract
The hippocampus is known to play a crucial role in learning and memory. Recent data from literature show that cognitive problems, common to aged or diabetic patients, may be related to accumulation of toxic alpha-oxoaldehydes such as methylglyoxal. Thus, it is possible that methylglyoxal could be, at least in part, responsible for the impairment of cognitive functions, and the knowledge of the mechanisms through which this compound elicits neuronal toxicity could be useful for the development of possible therapeutic strategies. We previously reported a high susceptibility of hippocampal neurons to methylglyoxal, through an oxidation-dependent mechanism. In the present study, we extend our investigation on the molecular mechanisms which underlie methylglyoxal toxicity, focusing on possible effects on expression and activity of glyoxalases, its main detoxifying enzymes, and glutathione peroxidase, as well as on the levels of reduced glutathione. We also investigate methylglyoxal-induced modulation of brain derived neurotrophic factor and proinflammatory cytokines. Our results show that methylglyoxal causes a dramatic depletion of reduced glutathione and a significant inhibition of both glyoxalase and glutathione peroxidase activities. Furthermore, methylglyoxal treatment seems to affect the expression of inflammatory cytokines and survival factors. In conclusion, our findings suggest that methylglyoxal-induced neurotoxicity occurs through the impairment of detoxification pathway and depletion of reduced glutathione. This, in turn, triggers widespread apoptotic cell death, occurring through the convergence of both mitochondrial and Fas-receptor pathways.
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Affiliation(s)
- Silvia Di Loreto
- Institute for Organ Transplantation and Immunocytology (ITOI), CNR, P. le Collemaggio, 67100 L'Aquila, Italy.
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Domico LM, Cooper KR, Bernard LP, Zeevalk GD. Reactive oxygen species generation by the ethylene-bis-dithiocarbamate (EBDC) fungicide mancozeb and its contribution to neuronal toxicity in mesencephalic cells. Neurotoxicology 2007; 28:1079-91. [PMID: 17597214 PMCID: PMC2141682 DOI: 10.1016/j.neuro.2007.04.008] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2006] [Revised: 04/26/2007] [Accepted: 04/26/2007] [Indexed: 12/25/2022]
Abstract
Previous in vitro studies in our laboratory have shown that mancozeb (MZ) and maneb (MB), both widely used EBDC fungicides, are equipotent neurotoxicants that produce cell loss in mesencephalic dopaminergic and GABAergic cells after an acute 24h exposure. Mitochondrial uncoupling and inhibition were associated with fungicide exposure. Inhibition of mitochondrial respiration is known to increase free radical production. Here the mechanism(s) of neuronal damage associated with MZ exposure was further explored by determining the role that reactive oxygen species (ROS) played in toxicity. Damage to mesencephalic dopamine and GABA cell populations were significantly attenuated when carried out in the presence of ascorbate or SOD, indicative of a free radical-mediated contribution to toxicity. ROS generation monitored by hydrogen peroxide (H(2)O(2)) production using Amplex Red increased in a dose-dependent manner in response to MZ. Inhibition of intracellular catalase with aminotriazole had little effect on H(2)O(2) generation, whereas exogenously added catalase significantly reduced H(2)O(2) production, demonstrating a large extracellular contribution to ROS generation. Conversely, cells preloaded with the ROS indicator dye DCF showed significant MZ-induced ROS production, demonstrating an increase in intracellular ROS. Both the organic backbone of MZ as well as its associated Mn ion, but not Zn ion, were responsible and required for H(2)O(2) generation. The functionally diverse NADPH oxidase inhibitors, diphenylene iodonium chloride, apocynin, and 4-(2-aminoethyl)benzene-sulfonyl fluoride hydrochloride significantly attenuated H(2)O(2) production by MZ. In growth medium lacking cells, MZ produced little H(2)O(2), but enhanced H(2)O(2) generation when added with xanthine plus xanthine oxidase whereas, in cultured cells, allopurinol partially attenuated H(2)O(2) production by MZ. Minocycline, an inhibitor of microglial activation, modestly reduced H(2)O(2) formation in mesencephalic cells. In contrast, neuronal-enriched cultures or cultures treated with MAC-1-SAP to kill microglia, did not show an attenuation of ROS production. These findings demonstrate that Mn-containing EBDC fungicides such as MZ and MB can produce robust ROS generation that likely occurs via redox cycling with extracellular and intracellular oxidases. The findings further show that microglia may contribute to but are not required for ROS production by MZ.
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Affiliation(s)
- Lisa M. Domico
- Joint Graduate Program in Toxicology, Rutgers The State University of New Jersey and University of Medicine and Dentistry of New Jersey, Piscataway, NJ, USA
| | - Keith R. Cooper
- Joint Graduate Program in Toxicology, Rutgers The State University of New Jersey and University of Medicine and Dentistry of New Jersey, Piscataway, NJ, USA
| | - Laura P. Bernard
- Department of Neurology, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, Piscataway, NJ, USA
| | - Gail D. Zeevalk
- Department of Neurology, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, Piscataway, NJ, USA
- *Corresponding author and reprint requests to Gail D. Zeevalk, Ph.D. Dept. of Neurology UMDNJ Robert Wood Johnson Medical School 675 Hoes Lane, Piscataway, New Jersey 08854, phone: 732 235 3494, fax: 732 235 5295,
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Liu D, Chan SL, de Souza-Pinto NC, Slevin JR, Wersto RP, Zhan M, Mustafa K, de Cabo R, Mattson MP. Mitochondrial UCP4 mediates an adaptive shift in energy metabolism and increases the resistance of neurons to metabolic and oxidative stress. Neuromolecular Med 2007; 8:389-414. [PMID: 16775390 DOI: 10.1385/nmm:8:3:389] [Citation(s) in RCA: 138] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2005] [Revised: 02/21/2006] [Accepted: 02/23/2006] [Indexed: 11/11/2022]
Abstract
The high-metabolic demand of neurons and their reliance on glucose as an energy source places them at risk for dysfunction and death under conditions of metabolic and oxidative stress. Uncoupling proteins (UCPs) are mitochondrial inner membrane proteins implicated in the regulation of mitochondrial membrane potential (Deltapsim) and cellular energy metabolism. The authors cloned UCP4 cDNA from mouse and rat brain, and demonstrate that UCP4 mRNA is expressed abundantly in brain and at particularly high levels in populations of neurons believed to have high-energy requirements. Neural cells with increased levels of UCP4 exhibit decreased Deltapsim, reduced reactive oxygen species (ROS) production and decreased mitochondrial calcium accumulation. UCP4 expressing cells also exhibited changes of oxygen-consumption rate, GDP sensitivity, and response of Deltapsim to oligomycin that were consistent with mitochondrial uncoupling. UCP4 modulates neuronal energy metabolism by increasing glucose uptake and shifting the mode of ATP production from mitochondrial respiration to glycolysis, thereby maintaining cellular ATP levels. The UCP4-mediated shift in energy metabolism reduces ROS production and increases the resistance of neurons to oxidative and mitochondrial stress. Knockdown of UCP4 expression by RNA interference in primary hippocampal neurons results in mitochondrial calcium overload and cell death. UCP4-mRNA expression is increased in neurons exposed to cold temperatures and in brain cells of rats maintained on caloric restriction, suggesting a role for UCP4 in the previously reported antiageing and neuroprotective effects of caloric restriction. By shifting energy metabolism to reduce ROS production and cellular reliance on mitochondrial respiration, UCP4 can protect neurons against oxidative stress and calcium overload.
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Affiliation(s)
- Dong Liu
- Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, MD, USA
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129
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Roh YJ, Moon C, Kim SY, Park MH, Bae YC, Chun MH, Moon JI. Glutathione depletion induces differential apoptosis in cells of mouse retina, in vivo. Neurosci Lett 2007; 417:266-70. [PMID: 17400377 DOI: 10.1016/j.neulet.2007.02.088] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2006] [Revised: 02/14/2007] [Accepted: 02/15/2007] [Indexed: 10/23/2022]
Abstract
Oxidative stress affects numerous intracellular macromolecules, and may result in cell death unless precisely regulated. Unregulated oxidative stress can be controlled by various cellular defense mechanisms such as glutathione (GSH) which can critically counteract the damaging effects of oxidative stress in mammalian cells. We determined the effects of unregulated oxidative stress induced by GSH depletion on cells in mouse retina. Mice were intraperitoneally injected with buthionine sulphoximine (BSO) at 1.5 g/kg. After 0, 1, 4, and 7 days of BSO administration, retinas were excised and sections were subjected to GSH assay and terminal uridine deoxynucleotidyl nick end labeling (TUNEL) analysis. After 4 days of BSO administration, the number of TUNEL positive cells was significantly increased. However, after 7 days, TUNEL positive cells returned to the basal level. The retinal region most affected by the BSO treatment appeared to be the outer nuclear layer where the photoreceptor cells reside. Different from cells in other regions, retinal cells in the inner nuclear layer increased in their apoptosis even after the first day of BSO injection, and the increase was further potentiated after 4 days. Taken together, our studies suggested that GSH depletion may cause unregulated oxidative stress to the cells in the retina and indeed increased cell death in the retina. The cells in the inner nuclear layer seemed to be affected earlier than the cells in other layers of the retina. The GSH level in the retina may be a crucial therapeutic target in preventing blindness.
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Affiliation(s)
- Young-Jung Roh
- Department of Ophthalmology, College of Medicine, The Catholic University of Korea, 62 Yeouido-Dong, Yeoungdeungpo-Ku, Seoul, 150-713, Seoul, Republic of Korea
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Bedard K, Krause KH. The NOX family of ROS-generating NADPH oxidases: physiology and pathophysiology. Physiol Rev 2007; 87:245-313. [PMID: 17237347 DOI: 10.1152/physrev.00044.2005] [Citation(s) in RCA: 4889] [Impact Index Per Article: 287.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
For a long time, superoxide generation by an NADPH oxidase was considered as an oddity only found in professional phagocytes. Over the last years, six homologs of the cytochrome subunit of the phagocyte NADPH oxidase were found: NOX1, NOX3, NOX4, NOX5, DUOX1, and DUOX2. Together with the phagocyte NADPH oxidase itself (NOX2/gp91(phox)), the homologs are now referred to as the NOX family of NADPH oxidases. These enzymes share the capacity to transport electrons across the plasma membrane and to generate superoxide and other downstream reactive oxygen species (ROS). Activation mechanisms and tissue distribution of the different members of the family are markedly different. The physiological functions of NOX family enzymes include host defense, posttranlational processing of proteins, cellular signaling, regulation of gene expression, and cell differentiation. NOX enzymes also contribute to a wide range of pathological processes. NOX deficiency may lead to immunosuppresion, lack of otoconogenesis, or hypothyroidism. Increased NOX activity also contributes to a large number or pathologies, in particular cardiovascular diseases and neurodegeneration. This review summarizes the current state of knowledge of the functions of NOX enzymes in physiology and pathology.
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Affiliation(s)
- Karen Bedard
- Biology of Ageing Laboratories, University of Geneva, Geneva, Switzerland
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131
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Avshalumov MV, Bao L, Patel JC, Rice ME. H2O2 signaling in the nigrostriatal dopamine pathway via ATP-sensitive potassium channels: issues and answers. Antioxid Redox Signal 2007; 9:219-31. [PMID: 17115944 DOI: 10.1089/ars.2007.9.219] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The role of reactive oxygen species (ROS) as signaling agents is increasingly appreciated. Studies of ROS functions in the central nervous system, however, are only in their infancy. Using fast-scan cyclic voltammetry and fluorescence imaging in brain slices, the authors discovered that hydrogen peroxide (H2O2) is an endogenous regulator of dopamine release in the dorsal striatum. Given the key role of dopamine in motor, reward, and cognitive pathways, regulation by H2O2 has implications for normal dopamine function, as well as for dysfunction of dopamine transmission. In this review, data are summarized to show that H2O2 is a diffusible messenger in the striatum, generated downstream from glutamate receptor activation, and an intracellular signal in dopamine neurons of the substantia nigra, generated during normal pacemaker activity. The mechanism by which H2O2 inhibits dopamine release and dopamine cell activity is activation of ATP-sensitive K+ (KATP) channels. Characteristics of the neuronal and glial antioxidant networks required to permit H2O2 signaling, yet prevent oxidative damage, are also considered. Lastly, estimates of physiological H2O2 levels are discussed, and strengths and limitations of currently available methods for H2O2 detection, including fluorescence imaging using dichlorofluorescein (DCF) and the next generation of fluorescent probes, are considered.
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Affiliation(s)
- Marat V Avshalumov
- Department of Neurosurgery and Department of Physiology and Neuroscience, New York University School of Medicine, New York 10016, USA
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132
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Abstract
Increasing evidence suggests that reactive oxygen species (ROS), such as superoxide and hydrogen peroxide, act as necessary signaling molecules in processes underlying cognition. Moreover, ROS have been shown to be necessary in molecular process underlying signal transduction, synaptic plasticity, and memory formation. Research from several laboratories suggests that NADPH oxidase is an important source of superoxide in the brain. Evidence is presented here to show that ROS are in fact important signaling molecules involved in synaptic plasticity and memory formation. Moreover, evidence that the NADPH oxidase complex is a key regulator of ROS generation in synaptic plasticity and memory formation is discussed. Understanding redox signaling in the brain, including the sources and molecular targets of ROS, are important for a full understanding of the signaling pathways that underlie synaptic plasticity and memory. Knowledge of ROS function in the brain also is critical for understanding aging and neurodegenerative diseases of the brain given that several of these disorders, including Alzheimer's disease and Parkinson disease, may be exacerbated by the unregulated generation of ROS.
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Affiliation(s)
- Kenneth T Kishida
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, USA
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Abstract
Superoxide dismutases (SODs) are the major antioxidant enzymes that inactivate superoxide and thereby control oxidative stress as well as redox signaling. Transgenic mice overexpressing different isozymes of SOD have been used to study the effect of SOD overexpression on hippocampal synaptic plasticity and hippocampus-dependent learning and memory. Studies with transgenic and wild-type animals of different ages show that the function of SOD overexpression changes across the life span of an animal, and comparisons between animals that overexpress different SOD isozymes suggest that the functional value of overexpression as well as the mechanisms through which the respective functional values are effected vary depending on isozyme. The work discussed in this review has important implications for the use of antioxidant treatments and for our understanding of the role of superoxide in physiological and pathological processes.
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Affiliation(s)
- Daoying Hu
- Department of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, Texas, USA
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Hu D, Cao P, Thiels E, Chu CT, Wu GY, Oury TD, Klann E. Hippocampal long-term potentiation, memory, and longevity in mice that overexpress mitochondrial superoxide dismutase. Neurobiol Learn Mem 2006; 87:372-84. [PMID: 17129739 PMCID: PMC1847321 DOI: 10.1016/j.nlm.2006.10.003] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2006] [Revised: 10/04/2006] [Accepted: 10/16/2006] [Indexed: 12/14/2022]
Abstract
Superoxide has been shown to be critically involved in several pathological manifestations of aging animals. In contrast, superoxide also can act as a signaling molecule to modulate signal transduction cascades required for hippocampal synaptic plasticity. Mitochondrial superoxide dismutase (SOD-2 or Mn-SOD) is a key antioxidant enzyme that scavenges superoxide. Thus, SOD-2 may not only prevent aging-related oxidative stress, but may also regulate redox signaling in young animals. We used transgenic mice overexpressing SOD-2 to study the role of mitochondrial superoxide in aging, synaptic plasticity, and memory-associated behavior. We found that overexpression of SOD-2 had no obvious effect on synaptic plasticity and memory formation in young mice, and could not rescue the age-related impairments in either synaptic plasticity or memory in old mice. However, SOD-2 overexpression did decrease mitochondrial superoxide in hippocampal neurons, and extended the lifespan of the mice. These findings increase our knowledge of the role of mitochondrial superoxide in physiological and pathological processes in the brain.
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Affiliation(s)
- Daoying Hu
- Department of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX 77030
| | - Peng Cao
- Department of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX 77030
| | - Edda Thiels
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261
- Center for the Neural Basis of Cognition, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261
| | - Charleen T. Chu
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261
| | - Gang-yi Wu
- Department of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX 77030
| | - Tim D. Oury
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261
| | - Eric Klann
- Department of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX 77030
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030
- * Correspondence should be sent to: Eric Klann, Ph.D., Department of Molecular Physiology & Biophysics, Baylor College of Medicine, One Baylor Plaza BCM 335, Houston, TX 77030, Phone: (713) 798-5630, Fax: (713) 798-3475, E-mail:
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Foster KA, Galeffi F, Gerich FJ, Turner DA, Müller M. Optical and pharmacological tools to investigate the role of mitochondria during oxidative stress and neurodegeneration. Prog Neurobiol 2006; 79:136-71. [PMID: 16920246 PMCID: PMC1994087 DOI: 10.1016/j.pneurobio.2006.07.001] [Citation(s) in RCA: 140] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2006] [Revised: 07/10/2006] [Accepted: 07/11/2006] [Indexed: 02/06/2023]
Abstract
Mitochondria are critical for cellular adenosine triphosphate (ATP) production; however, recent studies suggest that these organelles fulfill a much broader range of tasks. For example, they are involved in the regulation of cytosolic Ca(2+) levels, intracellular pH and apoptosis, and are the major source of reactive oxygen species (ROS). Various reactive molecules that originate from mitochondria, such as ROS, are critical in pathological events, such as ischemia, as well as in physiological events such as long-term potentiation, neuronal-vascular coupling and neuronal-glial interactions. Due to their key roles in the regulation of several cellular functions, the dysfunction of mitochondria may be critical in various brain disorders. There has been increasing interest in the development of tools that modulate mitochondrial function, and the refinement of techniques that allow for real time monitoring of mitochondria, particularly within their intact cellular environment. Innovative imaging techniques are especially powerful since they allow for mitochondrial visualization at high resolution, tracking of mitochondrial structures and optical real time monitoring of parameters of mitochondrial function. The techniques discussed include classic imaging techniques, such as rhodamine-123, the highly advanced semi-conductor nanoparticles (quantum dots), and wide field microscopy as well as high-resolution multiphoton imaging. We have highlighted the use of these techniques to study mitochondrial function in brain tissue and have included studies from our laboratories in which these techniques have been successfully applied.
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Affiliation(s)
- Kelley A. Foster
- Research and Surgery Services Durham Veterans Affairs Medical Center; Neurosurgery and Neurobiology, Duke University Medical Center, Box 3807, Durham, NC 27710, USA
| | - Francesca Galeffi
- Research and Surgery Services Durham Veterans Affairs Medical Center; Neurosurgery and Neurobiology, Duke University Medical Center, Box 3807, Durham, NC 27710, USA
| | - Florian J. Gerich
- Zentrum für Physiologie und Pathophysiologie, Abteilung Neuro- und Sinnesphysiologie, Georg-August-Universität Göttingen, Humboldtallee 23, D-37073 Göttingen, Germany
| | - Dennis A. Turner
- Research and Surgery Services Durham Veterans Affairs Medical Center; Neurosurgery and Neurobiology, Duke University Medical Center, Box 3807, Durham, NC 27710, USA
| | - Michael Müller
- DFG Center Molecular Physiology of the Brain, Georg-August-Universität Göttingen, Humboldtallee 23, D-37073 Göttingen, Germany
- Zentrum für Physiologie und Pathophysiologie, Abteilung Neuro- und Sinnesphysiologie, Georg-August-Universität Göttingen, Humboldtallee 23, D-37073 Göttingen, Germany
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136
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Tsatmali M, Walcott EC, Makarenkova H, Crossin KL. Reactive oxygen species modulate the differentiation of neurons in clonal cortical cultures. Mol Cell Neurosci 2006; 33:345-57. [PMID: 17000118 PMCID: PMC1797198 DOI: 10.1016/j.mcn.2006.08.005] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2006] [Revised: 08/08/2006] [Accepted: 08/17/2006] [Indexed: 10/24/2022] Open
Abstract
Reactive oxygen species (ROS) are important regulators of intracellular signaling. We examined the expression of ROS during rat brain development and explored their role in differentiation using cortical cultures. High levels of ROS were found in newborn neurons. Neurons produced ROS, not connected with cell death, throughout embryogenesis and postnatal stages. By P20, ROS-producing cells were found only in neurogenic regions. Cells with low levels of ROS, isolated from E15 brains by FACS, differentiated into neurons, oligodendrocytes, and astrocytes in clonal cultures. Neurons produced high ROS early in culture and later differentiated into two types: large pyramidal-like neurons that fired no or only a single action potential and smaller neurons that expressed nuclear calretinin and fired repeated action potentials. Antioxidant treatment did not alter neuron number but increased the ratio of small to large neurons. These findings suggest that modulation of ROS levels influences multiple aspects of neuronal differentiation.
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Affiliation(s)
- Marina Tsatmali
- Department of Neurobiology, SBR-14, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Elisabeth C. Walcott
- The Neurosciences Institute, 10640 John Jay Hopkins Drive, San Diego, CA 92121, USA
| | - Helen Makarenkova
- The Neurosciences Institute, 10640 John Jay Hopkins Drive, San Diego, CA 92121, USA
| | - Kathryn L. Crossin
- Department of Neurobiology, SBR-14, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
- *Corresponding Author: Fax: 858 784 2646., E-mail address: (K.L. Crossin)
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137
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Kishida KT, Hoeffer CA, Hu D, Pao M, Holland SM, Klann E. Synaptic plasticity deficits and mild memory impairments in mouse models of chronic granulomatous disease. Mol Cell Biol 2006; 26:5908-20. [PMID: 16847341 PMCID: PMC1592752 DOI: 10.1128/mcb.00269-06] [Citation(s) in RCA: 124] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Reactive oxygen species (ROS) are required in a number of critical cellular signaling events, including those underlying hippocampal synaptic plasticity and hippocampus-dependent memory; however, the source of ROS is unknown. We previously have shown that NADPH oxidase is required for N-methyl-D-aspartate (NMDA) receptor-dependent signal transduction in the hippocampus, suggesting that NADPH oxidase may be required for NMDA receptor-dependent long-term potentiation (LTP) and hippocampus-dependent memory. Herein we present the first evidence that NADPH oxidase is involved in hippocampal synaptic plasticity and memory. We have found that pharmacological inhibitors of NADPH oxidase block LTP. Moreover, mice that lack the NADPH oxidase proteins gp91(phox) and p47(phox), both of which are mouse models of human chronic granulomatous disease (CGD), also lack LTP. We also found that the gp91(phox) and p47(phox) mutant mice have mild impairments in hippocampus-dependent memory. The gp91(phox) mutant mice exhibited a spatial memory deficit in the Morris water maze, and the p47(phox) mutant mice exhibited impaired context-dependent fear memory. Taken together, our results are consistent with NADPH oxidase being required for hippocampal synaptic plasticity and memory and are consistent with reports of cognitive dysfunction in patients with CGD.
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Affiliation(s)
- Kenneth T Kishida
- Department of Neuroscience, Baylor College of Medicine, One Baylor Plaza BCM 335, Houston, TX 77030, USA
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138
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Pizzi M, Spano P. Distinct roles of diverse nuclear factor-kappaB complexes in neuropathological mechanisms. Eur J Pharmacol 2006; 545:22-8. [PMID: 16854410 DOI: 10.1016/j.ejphar.2006.06.027] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2005] [Revised: 03/22/2006] [Accepted: 06/13/2006] [Indexed: 12/18/2022]
Abstract
The nuclear transcription factors kappaB (NF-kappaB) function as key regulators of physiological processes in the central nervous system. Aberrant regulation of NF-kappaB can underlie neurological disorders associated with neurodegeneration. A large number of studies have reported a dual role of NF-kappaB in regulating neuron survival in pathological conditions. A recent progress in understanding the mechanisms responsible for opposite effects elicited by NF-kappaB in brain dysfunctions arises from the identification of diverse NF-kappaB complexes specifically involved in the mechanism of neuronal cell death or cell survival. We here discuss the latest findings and consider the therapeutic potential of targeting distinct NF-kappaB complexes for the treatment of neurodegenerative disorders and memory dysfunctions.
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Affiliation(s)
- Marina Pizzi
- Division of Pharmacology and Experimental Therapeutics, Department of Biomedical Sciences and Biotechnologies, School of Medicine, University of Brescia, I 25123, Italy.
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139
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Hu D, Serrano F, Oury TD, Klann E. Aging-dependent alterations in synaptic plasticity and memory in mice that overexpress extracellular superoxide dismutase. J Neurosci 2006; 26:3933-41. [PMID: 16611809 PMCID: PMC6673899 DOI: 10.1523/jneurosci.5566-05.2006] [Citation(s) in RCA: 140] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Oxidative damage caused by reactive oxygen species (ROS) has been proposed to be critically involved in several pathological manifestations of aging, including cognitive dysfunction. ROS, including superoxide, are generally considered as neurotoxic molecules whose effects can be alleviated by antioxidant enzymes. However, ROS also are known to be necessary components of the signal transduction cascades underlying normal synaptic plasticity. Therefore, we reasoned that the role that ROS and antioxidant enzymes play in modulating neuronal processes varies over the lifespan of an animal. We examined hippocampal long-term potentiation (LTP) and memory-related behavioral performance in transgenic mice overexpressing extracellular superoxide dismutase (EC-SOD) and their wild-type littermates at different ages. We found that aged EC-SOD transgenic mice exhibited enhanced hippocampal LTP, better cerebellum-dependent motor learning, and better hippocampus-dependent spatial learning compared with their wild-type littermates. We also found that EC-SOD overexpression impaired contextual learning, but the impairment was decreased in the aged transgenic mice. At the molecular level, aged EC-SOD transgenic mice had lower superoxide levels, a decrease in protein carbonyl levels, and a decrease in p38 and extracellular signal-regulated kinase 2 phosphorylation compared with aged wild-type mice. Our findings suggest that elevated levels of superoxide contribute to aging-related impairments in hippocampal LTP and memory, and that these impairments can be alleviated by overexpression of EC-SOD. We conclude that there is an age-dependent alteration in the role of superoxide in modulating synaptic plasticity and learning and memory.
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140
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Zhang Y, Yu Y, Zhang F, Zhong MK, Shi Z, Gao XY, Wang W, Zhu GQ. NAD(P)H oxidase in paraventricular nucleus contributes to the effect of angiotensin II on cardiac sympathetic afferent reflex. Brain Res 2006; 1082:132-41. [PMID: 16519880 DOI: 10.1016/j.brainres.2006.01.113] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2005] [Revised: 01/26/2006] [Accepted: 01/28/2006] [Indexed: 11/15/2022]
Abstract
We previously reported that reactive oxygen species (ROS) in paraventricular nucleus (PVN) modulated cardiac sympathetic afferent reflex (CSAR) and mediated the effect of angiotensin II (Ang II) in the PVN on the CSAR. In the present study, we investigated whether the NAD(P)H oxidase in the PVN was a key source of ROS which modulated the CSAR and contributed to the effect of Ang II on the CSAR. In anesthetized rats with sinoaortic denervation and vagotomy, renal sympathetic nerve activity (RSNA) and arterial pressure were recorded. The CSAR was evaluated by the RSNA response to epicardial application of bradykinin (BK). The NAD(P)H oxidase activity in the PVN was measured with lucigenin-enhanced chemiluminescent method. Microinjection of the NAD(P)H oxidase inhibitor, either apocynin (1.0 nmol) or phenylarsine oxide (PAO, 1.0 nmol), into the PVN significantly inhibited the CSAR. Microinjection of Ang II (0.3 nmol) into the PVN significantly augmented the CSAR. The effects of Ang II were not only abolished by pretreatment with either apocynin or PAO in the PVN but also partially inhibited by xanthine oxidase inhibitor allopurinol. Either epicardial application of BK or microinjection of Ang II into the PVN significantly increased NAD(P)H oxidase activity in the PVN. The effect of Ang II on NAD(P)H oxidase activity was abolished by pretreatment with AT(1) receptor antagonist losartan in the PVN. These findings suggested that NAD(P)H oxidase in the PVN was a major source of the ROS in modulating the CSAR, and the NAD(P)H oxidase contributes to the effect of Ang II on the CSAR.
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Affiliation(s)
- Ying Zhang
- Department of Physiology, Nanjing Medical University, Nanjing 210029, China
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141
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Gericke GS. Reactive oxygen species and related haem pathway components as possible epigenetic modifiers in neurobehavioural pathology. Med Hypotheses 2006; 66:92-9. [PMID: 16183208 DOI: 10.1016/j.mehy.2005.07.031] [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: 06/28/2005] [Accepted: 07/04/2005] [Indexed: 11/20/2022]
Abstract
The neuroendocrine response to stress utilizes several bio-communicative pathways which also play a role in neurodevelopmental plasticity. The mechanism of action of steroidal compounds includes DNA alteration by reactive oxygen species (ROS) arising through redox cycling of reactive hormone derivatives. ROS and reactive nitrogen species play a significant role in signaling networks affecting gene transcriptional regulation during normal as well as stress-induced responses. ROS-associated synaptic and regulatory region plasticity may have been important for normal brain evolution, but probably simultaneously lowered the threshold for inducing neuropathology. A shift from 'plasticity' to 'instability' is likely to be associated with the emergence of complex effects depending on the timing, duration and intensity of the ROS insult, and is suggested to include heritable epigenetic chromatin/regulatory region remodeling differentially influencing expression levels of significant neuropsychiatric genes and their variant alleles. Neurobehavioural disorder clinical manifestations have been linked with ROS effects. The concepts discussed here relate to ROS-associated instability of DNA regulatory region sequences and a proposal that it may play an important modifying role in brain and neuro-behaviourally related gene expression. Genes encoding key steps in mitochondrial, haem, iron and bilirubin ROS metabolic pathways have been used as examples to illustrate how ROS-modified regulatory networks could possibly alter the context within which (even ostensibly unrelated) neuropsychiatric gene candidates may sometimes be recruited. Furthermore, reactions of certain radicals release sufficient energy to generate UV-photons. DNA conformational changes accompanied by changes in photon emission suggest that functional neuroimaging findings probably reflect interaction on the level of ROS/biophoton/genome regulatory region domains rather than the signatures of individual neurobehavioural disorder candidate genes.
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Affiliation(s)
- G S Gericke
- Genetics Division, Ampath National Pathology Laboratories, P.O. Box 2040, Brooklyn Square, 0075 Pretoria, Gauteng, South Africa.
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142
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Hwang IK, Hua L, Yoo KY, Kim DW, Kang TC, Choi SY, Won MH, Kim DH. Antioxidant-like protein 1 is altered in non-pyramidal cells and expressed in astrocytes in the gerbil hippocampal CA1 region after transient forebrain ischemia. Brain Res 2005; 1062:111-9. [PMID: 16256080 DOI: 10.1016/j.brainres.2005.09.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2005] [Revised: 09/15/2005] [Accepted: 09/25/2005] [Indexed: 11/26/2022]
Abstract
In the present study, we observed chronological changes of antioxidant-like protein 1 (AOP-1) in the gerbil hippocampal CA1 region after 5 min of transient forebrain ischemia using immunohistochemistry and western blot. AOP-1 was significantly altered in the CA1 region after transient ischemia. In the sham-operated group, AOP-1 immunoreactivity was detected in pyramidal and non-pyramidal cells of the CA1 region. At 30 min after ischemic insult, AOP-1 immunoreactivity and protein level was decreased in the CA1 region. At 12 h after ischemic insult, AOP-1 immunoreactivity and protein level was highest in this region. At this time, after ischemia, AOP-1 immunoreactivity in non-pyramidal cells was high compared to the sham-operated group. Based on double immunofluorescence study, AOP-1-immunoreactive neurons were identified as GABAergic, which were stained with GAD or parvalbumin. Thereafter, AOP-1 immunoreactivity and protein levels were decreased time-dependently. From 4 days after ischemic insult, AOP 1 immunoreactivity was generally expressed in astrocytes. Five days after ischemic insult, AOP-1 immunoreactivity and protein level was increased again to 1.4 folds compared to that of the sham-operated group. In brief, AOP-1 immunoreactivity was increased in GABAergic non-pyramidal cells in the hippocampal CA1 region at early time after ischemic insult and was expressed in astrocytes at late time after ischemia. This result suggests that AOP-1 may be important role in homeostasis of GABAergic neurons because these neurons are resistant to ischemic damage.
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Affiliation(s)
- In Koo Hwang
- Department of Anatomy, College of Medicine, Hallym University, Chunchon 200-702, South Korea
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143
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Ross CM. Folate, mitochondria, ROS, and the aging brain. Am J Med 2005; 118:1174; author reply 1174-5. [PMID: 16194653 DOI: 10.1016/j.amjmed.2005.03.033] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2005] [Accepted: 03/01/2005] [Indexed: 10/25/2022]
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144
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Viggiano A, Monda M, Viggiano A, Viggiano D, Viggiano E, Chiefari M, Aurilio C, De Luca B. Trigeminal pain transmission requires reactive oxygen species production. Brain Res 2005; 1050:72-8. [PMID: 15979588 DOI: 10.1016/j.brainres.2005.05.021] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2005] [Revised: 05/10/2005] [Accepted: 05/10/2005] [Indexed: 10/25/2022]
Abstract
Three experiments were conducted in order to investigate the possible involvement of the reactive oxygen species in the nociception within the subnucleus caudalis of the spinal trigeminal nucleus (Vc). In the first experiment the extracellular level of hydrogen peroxide was evaluated by microdialysis in the Vc of two groups of six rats before and after a formalin (group 1) or saline solution (group 2) injection into the upper lip. In the second experiment the formalin test was conducted in three groups of 6 rats after a microinjection of 2-methoxyestradiol (2-ME, a superoxide-dismutase inhibitor; group 1) or N-acetylcysteine (NAC, an oxygen intermediate scavenger; group 2) or saline solution (group 3) into the Vc. In the third experiment an histochemical assay for superoxide dismutase activity was performed on two groups of 4 rats each 2 h after a formalin (group 1) or saline solution (group 2) injection into the upper lip. The results showed that (1) the level of hydrogen peroxide increases into the Vc during facial pain (134% of baseline); (2) the inhibition of superoxide dismutase or the removal of oxygen intermediate within the Vc decreases the sensibility to facial pain stimuli; and (3) persistent facial pain stimuli decrease the superoxide activity into the Vc (90% of counter-lateral). These data indicate that reactive oxygen species are produced in the Vc during persistent facial pain and are necessary for the transmission of pain.
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Affiliation(s)
- Andrea Viggiano
- Department of Experimental Medicine-Section Human Physiology, Second University of Naples, Via Costantinopoli, 16, Naples 80138, Italy
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145
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Hongpaisan J, Winters CA, Andrews SB. Strong calcium entry activates mitochondrial superoxide generation, upregulating kinase signaling in hippocampal neurons. J Neurosci 2005; 24:10878-87. [PMID: 15574738 PMCID: PMC6730216 DOI: 10.1523/jneurosci.3278-04.2004] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Large increases in cytosolic free Ca2+ ([Ca2+]i) activate several kinases that are important for neuronal plasticity, including Ca2+/calmodulin-dependent kinase II (CaMKII), protein kinase A (PKA), and protein kinase C (PKC). Because it is also known, mainly in non-neuronal systems, that superoxide radicals (O2-) activate these (and other) kinases and because O2- generation by mitochondria is in part [Ca2+]i dependent, we examined in hippocampal neurons the relationship between Ca2+ entry, O2- production, and kinase activity. We found that, after large stimulus-induced [Ca2+]i increases, O2- selectively produced by mitochondria near plasmalemmal sites of Ca2+ entry acts as a modulator to upregulate the two kinases, namely, CaMKII and PKA, whose activities are directly or indirectly phosphorylation dependent. The common mechanism involves O2- inhibition of inactivating protein phosphatases. Conversely, because small [Ca2+]i increases do not promote mitochondrial respiration and O2- generation, weak stimuli favor enhanced phosphatase activity, which therefore leads to suppressed kinase activity. Enhanced O2- production also promoted PKC activity but by a phosphatase-independent pathway. These results suggest that Ca2+-dependent upregulation of mitochondrial O2- production may be a general mechanism for linking Ca2+ entry to enhanced kinase activity and therefore to synaptic plasticity. This mechanism also represents yet another way that mitochondria, acting as calcium sensors, can play a role in neuronal signal transduction.
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Affiliation(s)
- Jarin Hongpaisan
- Laboratory of Neurobiology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892-4062, USA
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146
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Tejada-Simon MV, Serrano F, Villasana LE, Kanterewicz BI, Wu GY, Quinn MT, Klann E. Synaptic localization of a functional NADPH oxidase in the mouse hippocampus. Mol Cell Neurosci 2005; 29:97-106. [PMID: 15866050 PMCID: PMC2013304 DOI: 10.1016/j.mcn.2005.01.007] [Citation(s) in RCA: 168] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2004] [Revised: 12/09/2004] [Accepted: 01/04/2005] [Indexed: 01/04/2023] Open
Abstract
Superoxide has been shown to be critical for hippocampal long-term potentiation (LTP) and hippocampus-dependent memory function. A possible source for the generation of superoxide during these processes is NADPH oxidase. The active oxidase consists of two membrane proteins, gp91phox and p22phox, and four cytosolic proteins, p40phox, p47phox, p67phox, and Rac. Upon stimulation, the cytosolic proteins translocate to the membrane to form a complex with the membrane components, which results in production of superoxide. Here, we determined the presence, localization, and functionality of a NADPH oxidase in mouse hippocampus by examining the NADPH oxidase proteins as well as the production of superoxide. All of the NADPH oxidase proteins were present in hippocampal homogenates and enriched in synaptoneurosome preparations. Immunocytochemical analysis of cultured hippocampal neurons indicated that all NADPH oxidase proteins were localized in neuronal cell bodies as well as dendrites. Furthermore, double labeling analysis using antibodies to p67phox and the presynaptic marker synaptophysin suggest a close association of the NADPH oxidase subunits with synaptic sites. Finally, stimulation of hippocampal slices with phorbol esters triggered translocation of the cytoplasmic NADPH oxidase proteins to the membrane and an increase in superoxide production that was blocked by inhibitors of NADPH oxidase. Taken together, our data suggest that NADPH oxidase is present in mouse hippocampus and might be the source of superoxide production required for LTP and memory function.
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Affiliation(s)
- Maria V. Tejada-Simon
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Faridis Serrano
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Laura E. Villasana
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Beatriz I. Kanterewicz
- Department of Neuroscience and the Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Gang-Yi Wu
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Mark T. Quinn
- Department of Veterinary Molecular Biology, Montana State University, Bozeman, MT 59717-3610, USA
| | - Eric Klann
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
- * Corresponding author. Department of Molecular Physiology and Biophysics, One Baylor Plaza BCM 335, Houston, TX 77030, USA. Fax: +1 713 798 3475. E-mail address: (E. Klann)
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147
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Tsatmali M, Walcott EC, Crossin KL. Newborn neurons acquire high levels of reactive oxygen species and increased mitochondrial proteins upon differentiation from progenitors. Brain Res 2005; 1040:137-50. [PMID: 15804435 DOI: 10.1016/j.brainres.2005.01.087] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2004] [Revised: 01/21/2005] [Accepted: 01/24/2005] [Indexed: 01/19/2023]
Abstract
A population of embryonic rat cortical cells cultured in the presence of FGF2 and having neuronal morphology expressed higher levels of reactive oxygen species (ROS) than did progenitor cells, astrocytes, and several cell lines of neuronal and non-neuronal origin. ROS were assessed using 5-(and-6)-chlormethyl-2',7'-dichlorodihydrofluorescein diacetate, acetyl ester (CM-H2DCF-DA), and high levels persisted in the presence of antioxidants or lowered levels of ambient oxygen. Greater than 95% of high ROS-producing cells, isolated by fluorescence-activated cell sorting, expressed the neuronal marker beta III tubulin. These cells did not incorporate BrdU or express nestin, unlike low ROS-producing cells, 99% of which exhibited both of these characteristics. Upon growth factor removal, low ROS-expressing cells differentiated into neurons and astrocytes and these neurons expressed high levels of ROS, indicating that ROS accumulation accompanies the differentiation of progenitors into neurons. ROS levels were decreased by added superoxide dismutase and catalase, suggesting that both superoxide and hydrogen peroxide contribute to the ROS signal. High ROS-expressing cells also contained higher levels of several mitochondrial respiratory chain components. Although ROS have been associated with conditions that lead to cell death, our results and recent studies on the role of ROS as regulators of signal pathways are consistent with the possibility that ROS play a role in the development of the neuronal phenotype. Moreover, the differential production of ROS provides a useful method to isolate from mixed populations cells that are highly enriched for either progenitor cells or neurons.
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Affiliation(s)
- Marina Tsatmali
- Department of Neurobiology, SBR-14, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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148
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Gao L, Wang W, Li YL, Schultz HD, Liu D, Cornish KG, Zucker IH. Sympathoexcitation by central ANG II: roles for AT1 receptor upregulation and NAD(P)H oxidase in RVLM. Am J Physiol Heart Circ Physiol 2005; 288:H2271-9. [PMID: 15637113 DOI: 10.1152/ajpheart.00949.2004] [Citation(s) in RCA: 168] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Chronic heart failure is often associated with sympathoexcitation and blunted arterial baroreflex function. These phenomena have been causally linked to elevated central ANG II mechanisms. Recent studies have shown that NAD(P)H oxidase-derived reactive oxygen species (ROS) are important mediators of ANG II signaling and therefore might play an essential role in these interactions. The aims of this study were to determine whether central subchronic infusion of ANG II in normal animals has effects on O2- production and expression of NAD(P)H oxidase subunits as well as ANG II type 1 (AT1) receptors in the rostral ventrolateral medulla (RVLM). Twenty-four male New Zealand White rabbits were divided into four groups and separately received a subchronic intracerebroventricular infusion of saline alone, ANG II alone, ANG II with losartan, and losartan alone for 1 wk. On day 7 of intracerebroventricular infusion, mean arterial pressure (MAP), heart rate (HR), and renal sympathetic nerve activity (RSNA) values were recorded, and arterial baroreflex sensitivity was evaluated while animals were in the conscious state. We found that ANG II significantly increased baseline RSNA (161.9%; P < 0.05), mRNA and protein expression of AT1 receptors (mRNA, 66.7%; P < 0.05; protein, 85.1%; P < 0.05), NAD(P)H oxidase subunits (mRNA, 120.0-200.0%; P < 0.05; protein, 90.9-197.0%; P < 0.05), and O2- production (83.2%; P < 0.05) in the RVLM. In addition, impaired baroreflex control of HR (Gain(max) reduced by 48.2%; P < 0.05) and RSNA (Gain(max) reduced by 53.6%; P < 0.05) by ANG II was completely abolished by losartan. Losartan significantly decreased baseline RSNA (-49.5%; P < 0.05) and increased baroreflex control of HR (Gain(max) increased by 64.8%; P < 0.05) and RSNA (Gain(max) increased by 67.9%; P < 0.05), but had no significant effects on mRNA and protein expression of AT1 receptor and NAD(P)H oxidase subunits and O2- production in the RVLM. These data suggest that in normal rabbits, NAD(P)H oxidase-derived ROS play an important role in the modulation of sympathetic activity and arterial baroreflex function by subchronic central treatment of exogenous ANG II via AT1 receptors.
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Affiliation(s)
- Lie Gao
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, Nebraska 68198-5850, USA
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149
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Heusler P, Boehmer G. The superoxide anion is involved in the induction of long-term potentiation in the rat somatosensory cortex in vitro. Brain Res 2005; 1024:104-12. [PMID: 15451371 DOI: 10.1016/j.brainres.2004.07.047] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/28/2004] [Indexed: 11/23/2022]
Abstract
The involvement of the superoxide anion (O2-) in the induction of neocortical long-term potentiation (LTP) was examined in rat brain slices containing the primary somatosensory cortex. Field potentials evoked by stimulation in cortical layer IV were recorded from layer II/III. In control experiments, tetanic high-frequency stimulation (HFS) resulted in essentially input-specific, NMDA receptor-dependent LTP (20.2+/-3.0% increase in field potential amplitude). When the availability of intracellular O2- was reduced by application of the cell membrane-permeable O2- scavengers MnTBAP or CP-H (spin trap), HFS-induced LTP was attenuated to 12.0+/-1.7% and 8.7+/-3.1% increase, respectively. In contrast, HFS-induced LTP was not significantly affected by the cell membrane-impermeable O2- scavenger superoxide dismutase (SOD). Induction of the generation of O2- by the cell membrane-permeable redox-cycling quinone DMNQ resulted in a HFS-independent slow-onset LTP (21.8+/-6.0%) in three of eight brain slices. Together, these results suggest the contribution of O2- to the induction of LTP in the primary somatosensory cortex by an action on intracellular induction mechanisms.
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Affiliation(s)
- Peter Heusler
- Institute of Physiology and Pathophysiology, Johannes Gutenberg University, Duesbergweg 6, D-55099 Mainz, Germany
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Higo T, Hattori M, Nakamura T, Natsume T, Michikawa T, Mikoshiba K. Subtype-Specific and ER Lumenal Environment-Dependent Regulation of Inositol 1,4,5-Trisphosphate Receptor Type 1 by ERp44. Cell 2005; 120:85-98. [PMID: 15652484 DOI: 10.1016/j.cell.2004.11.048] [Citation(s) in RCA: 301] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2004] [Revised: 08/24/2004] [Accepted: 11/18/2004] [Indexed: 11/24/2022]
Abstract
Inositol 1,4,5-trisphosphate receptors (IP(3)Rs) are intracellular channel proteins that mediate Ca(2+) release from the endoplasmic reticulum (ER) and are involved in many biological processes and diseases. IP(3)Rs are differentially regulated by a variety of cytosolic proteins, but their regulation by ER lumenal protein(s) remains largely unexplored. In this study, we found that ERp44, an ER lumenal protein of the thioredoxin family, directly interacts with the third lumenal loop of IP(3)R type 1 (IP(3)R1) and that the interaction is dependent on pH, Ca(2+) concentration, and redox state: the presence of free cysteine residues in the loop is required. Ca(2+)-imaging experiments and single-channel recording of IP(3)R1 activity with a planar lipid bilayer system demonstrated that IP(3)R1 is directly inhibited by ERp44. Thus, ERp44 senses the environment in the ER lumen and modulates IP(3)R1 activity accordingly, which should in turn contribute to regulating both intralumenal conditions and the complex patterns of cytosolic Ca(2+) concentrations.
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Affiliation(s)
- Takayasu Higo
- Department of Molecular Neurobiology, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
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