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Gietzen DW, Lindström SH, Sharp JW, Teh PS, Donovan MJ. Indispensable Amino Acid-Deficient Diets Induce Seizures in Ketogenic Diet-Fed Rodents, Demonstrating a Role for Amino Acid Balance in Dietary Treatments for Epilepsy. J Nutr 2018; 148:480-489. [PMID: 29546295 PMCID: PMC6669944 DOI: 10.1093/jn/nxx030] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Revised: 08/21/2017] [Accepted: 10/30/2017] [Indexed: 11/13/2022] Open
Abstract
Background Low protein amounts are used in ketogenic diets (KDs), where an essential (indispensable) amino acid (IAA) can become limiting. Because the chemically sensitive, seizurogenic, anterior piriform cortex (APC) is excited by IAA limitation, an imbalanced KD could exacerbate seizure activity. Objective We questioned whether dietary IAA depletion worsens seizure activity in rodents fed KDs. Methods In a series of 6 trials, male rats or gerbils of both sexes (6-8/group) were given either control diets (CDs) appropriate for each trial, a KD, or a threonine-devoid (ThrDev) diet for ≥7 d, and tested for seizures using various stimuli. Microchip analysis of rat APCs was also used to determine if changes in transcripts for structures relevant to seizurogenesis are affected by a ThrDev diet. Glutamate release was measured in microdialysis samples from APCs during the first meal after 7 d on a CD or a ThrDev diet. Results Adult rats showed increased susceptibility to seizures in both chemical (58%) and electroshock (doubled) testing after 7 d on a ThrDev diet compared with CD (each trial, P ≤ 0.05). Seizure-prone Mongolian gerbils had fewer seizures after receiving a KD, but exacerbated seizures (68%) after 1 meal of KD minus Thr (KD-T compared with CD, P < 0.05). In kindled rats fed KD-T, both counts (19%) and severities (77%) of seizures were significantly elevated (KD-T compared with CD, P < 0.05). Gene transcript changes were consistent with enhanced seizure susceptibility (7-21 net-fold increases, P = 0.045-0.001) and glutamate release into the APC was increased acutely (4-fold at 20 min, 2.6-fold at 60 min, P < 0.05) after 7 d on a ThrDev diet. Conclusion Seizure severity in rats and gerbils was reduced after KDs and exacerbated by ThrDev, both in KD- and CD-fed animals, consistent with the mechanistic studies. We suggest that a complete protein profile in KDs may improve IAA balance in the APC, thereby lowering the risk of seizures.
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102
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Mehrabi S, Sanadgol N, Barati M, Shahbazi A, Vahabzadeh G, Barzroudi M, Seifi M, Gholipourmalekabadi M, Golab F. Evaluation of metformin effects in the chronic phase of spontaneous seizures in pilocarpine model of temporal lobe epilepsy. Metab Brain Dis 2018; 33:107-114. [PMID: 29080083 DOI: 10.1007/s11011-017-0132-z] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Accepted: 10/09/2017] [Indexed: 11/28/2022]
Abstract
Temporal lobe epilepsy (TLE) is a common form of drug-resistant epilepsy that sometimes responds to dietary manipulation such as the 'ketogenic diet'. Here we have investigated the effects of metformin in the rat pilocaroin model of TLE. Male rats were treated with intra peritoneal injection of pilocarpine hydrochloride, in dose of 360 mg/kg to induce status epilepticus (SE). At 45 day after induction of SE, metformin was injected intraperitoneally in dose of 250 mg/kg/day for 5 days. We show that metformin potently reduces the progression of seizures and blocks seizure-induced over-expression of brain-derived neurotropic factor (BDNF) and its receptor, Tropomyosin receptor kinase B (TrkB). We have shown that this reduced expression pattern is mediated by the transcriptional co-repressor CtBP (C-terminal binding protein). Moreover, metformin decreased mechanistic target of rapamycin (mTOR) activation through activation of AMP-activated protein kinase (AMPK) signaling pathway. Our findings have been shown that metformin has anticonvulsant and antiepileptic properties, and suggesting that antiglycolytic compounds such as metformin may represent a new class of drugs for treating epilepsy.
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Affiliation(s)
- Soraya Mehrabi
- Cellular and Molecular Research Center, Iran University of Medical Science, Tehran, Iran
| | - Nima Sanadgol
- Department of Biology, Faculty of Sciences, University of Zabol, Zabol, Iran
- Young Researchers and Elite Club, Zahedan Branch, Islamic Azad University, Zahedan, Iran
| | - Mahmood Barati
- Department of Biotechnology, Faculty of Allied Medicine, Iran University of Medical Science, Tehran, Iran
| | - Ali Shahbazi
- Faculty of Advanced Technologies in Medicine, Department of Neuroscience, Iran University of Medical Sciences, Tehran, Iran
| | - Gelareh Vahabzadeh
- Cellular and Molecular Research Center, Iran University of Medical Science, Tehran, Iran
- Department of Pharmacology, Iran University of Medical Sciences, Tehran, Iran
| | - Mitra Barzroudi
- Department of Anatomy, Iran University of Medical Sciences, Tehran, Iran
| | - Morteza Seifi
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Mazaher Gholipourmalekabadi
- Department of Tissue Engineering & Regenerative Medicine, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Fereshteh Golab
- Cellular and Molecular Research Center, Iran University of Medical Science, Tehran, Iran.
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103
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Hwang JY, Zukin RS. REST, a master transcriptional regulator in neurodegenerative disease. Curr Opin Neurobiol 2018; 48:193-200. [PMID: 29351877 DOI: 10.1016/j.conb.2017.12.008] [Citation(s) in RCA: 136] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 12/04/2017] [Accepted: 12/17/2017] [Indexed: 12/19/2022]
Abstract
The restrictive element-1 silencing transcription factor)/NRSF (neuron-restrictive silencing factor (NRSF) is a transcriptional repressor which acts via epigenetic remodeling to silence target genes. Emerging evidence indicates that REST is a master transcriptional regulator of neuron-specific genes not only in neurogenesis and neuronal differentiation, but also in differentiated neurons during the critical period in postnatal brain development, where it plays a role in fine-tuning of genes involved in synaptic plasticity, and in normal aging, where it promotes neuroprotection by repressing genes involved in oxidative stress and β-amyloid toxicity. This review focuses on recent findings that dysregulation of REST and REST-dependent epigenetic remodeling provide a central mechanism critical to the progressive neurodegeneration associated with neurologic disorders and diseases including global ischemia, stroke, epilepsy, Alzheimer's and Huntington's disease.
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Affiliation(s)
- Jee-Yeon Hwang
- Dominick P. Purpura Department of Neuroscience, Rose F. Kennedy Center, Room 610, Albert Einstein College of Medicine, 1300 Morris Park Avenue, New York, NY 10461, USA
| | - R Suzanne Zukin
- Dominick P. Purpura Department of Neuroscience, Rose F. Kennedy Center, Room 610, Albert Einstein College of Medicine, 1300 Morris Park Avenue, New York, NY 10461, USA.
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104
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Martínez-François JR, Fernández-Agüera MC, Nathwani N, Lahmann C, Burnham VL, Danial NN, Yellen G. BAD and K ATP channels regulate neuron excitability and epileptiform activity. eLife 2018; 7:32721. [PMID: 29368690 PMCID: PMC5785210 DOI: 10.7554/elife.32721] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 01/12/2018] [Indexed: 12/17/2022] Open
Abstract
Brain metabolism can profoundly influence neuronal excitability. Mice with genetic deletion or alteration of Bad (BCL-2 agonist of cell death) exhibit altered brain-cell fuel metabolism, accompanied by resistance to acutely induced epileptic seizures; this seizure protection is mediated by ATP-sensitive potassium (KATP) channels. Here we investigated the effect of BAD manipulation on KATP channel activity and excitability in acute brain slices. We found that BAD’s influence on neuronal KATP channels was cell-autonomous and directly affected dentate granule neuron (DGN) excitability. To investigate the role of neuronal KATP channels in the anticonvulsant effects of BAD, we imaged calcium during picrotoxin-induced epileptiform activity in entorhinal-hippocampal slices. BAD knockout reduced epileptiform activity, and this effect was lost upon knockout or pharmacological inhibition of KATP channels. Targeted BAD knockout in DGNs alone was sufficient for the antiseizure effect in slices, consistent with a ‘dentate gate’ function that is reinforced by increased KATP channel activity.
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Affiliation(s)
| | | | - Nidhi Nathwani
- Department of Neurobiology, Harvard Medical School, Boston, United States
| | - Carolina Lahmann
- Department of Neurobiology, Harvard Medical School, Boston, United States
| | - Veronica L Burnham
- Department of Neurobiology, Harvard Medical School, Boston, United States
| | - Nika N Danial
- Department of Neurobiology, Harvard Medical School, Boston, United States.,Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, United States
| | - Gary Yellen
- Department of Neurobiology, Harvard Medical School, Boston, United States
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105
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Song Z, Zhu T, Zhou X, Barrow P, Yang W, Cui Y, Yang L, Zhao D. REST alleviates neurotoxic prion peptide-induced synaptic abnormalities, neurofibrillary degeneration and neuronal death partially via LRP6-mediated Wnt-β-catenin signaling. Oncotarget 2017; 7:12035-52. [PMID: 26919115 PMCID: PMC4914267 DOI: 10.18632/oncotarget.7640] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2015] [Accepted: 02/14/2016] [Indexed: 02/07/2023] Open
Abstract
Prion diseases are a group of infectious neurodegenerative diseases characterized by multiple neuropathological hallmarks including synaptic damage, spongiform degeneration and neuronal death. The factors and mechanisms that maintain cellular morphological integrity and protect against neurodegeneration in prion diseases are still unclear. Here we report that after stimulation with the neurotoxic PrP106-126 fragment in primary cortical neurons, REST translocates from the cytoplasm to the nucleus and protects neurons from harmful effects of PrP106-126. Overexpression of REST reduces pathological damage and abnormal biochemical alterations of neurons induced by PrP106-126 and maintains neuronal viability by stabilizing the level of pro-survival protein FOXO1 and inhibiting the permeability of the mitochondrial outer membrane, release of cytochrome c from mitochondria to cytoplasm and the activation of Capase3. Conversely, knockdown of REST exacerbates morphological damage and inhibits the expression of FOXO1. Additionally, by overexpression or knockdown of LRP6, we further show that LRP6-mediated Wnt-β-catenin signaling partly regulates the expression of REST. Collectively, we demonstrate for the first time novel neuroprotective function of REST in prion diseases and hypothesise that the LRP6-Wnt-β-catenin/REST signaling plays critical and collaborative roles in neuroprotection. This signaling of neuronal survival regulation could be explored as a viable therapeutic target for prion diseases and associated neurodegenerative diseases.
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Affiliation(s)
- Zhiqi Song
- The State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Ting Zhu
- The State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Xiangmei Zhou
- The State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Paul Barrow
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, Leicestershire, UK
| | - Wei Yang
- The State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Yongyong Cui
- The State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Lifeng Yang
- The State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Deming Zhao
- The State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
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106
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Ghosh S, Castillo E, Frias ES, Swanson RA. Bioenergetic regulation of microglia. Glia 2017; 66:1200-1212. [PMID: 29219210 DOI: 10.1002/glia.23271] [Citation(s) in RCA: 170] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 10/31/2017] [Accepted: 11/09/2017] [Indexed: 02/06/2023]
Abstract
Microglia have diverse actions, ranging from synapse pruning in development to cytotoxic effects in disease. Brain energy metabolism and substrate availability vary under normal and disease states, but how these variations influence microglial function is relatively unknown. Microglia, like most other cell types, express the full complement of gene products required for both glycolytic and oxidative metabolism. Evidence suggests that microglia increase aerobic glycolysis and decrease respiration when activated by various stimuli. Mitochondrial function, glucose availability, and glycolytic rate influence pro-inflammatory gene expression at both transcriptional and post-translational levels. These effects are mediated through CtBP, an NADH-sensitive transcriptional co-repressor; through effects on NLRP3 inflammasome assembly and caspase-1 activation; through formation of advanced glycation end-products; and by less well-defined mechanisms. In addition to these transcriptional effects, microglial glucose metabolism is also required for superoxide production by NADPH oxidase, as glucose is the obligate substrate for regenerating NADPH in the hexose monophosphate shunt. Microglia also metabolize acetoacetate and β-hydroxybutyrate, which are generated during fasting or ketogenic diet, and respond to these ketones as metabolic signals. β-Hydroxybutyrate inhibits histone de-acetylases and activates microglial GRP109A receptors. These actions suppress microglia activation after brain injury and promote neuroprotective microglia phenotypes. As our understanding of microglial activation matures, additional links between energy metabolism and microglial function are likely to be identified.
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Affiliation(s)
- Soumitra Ghosh
- Department of Neurology, University of California San Francisco, San Francisco, CA.,Department of Neurology, San Francisco Veterans Affairs Medical Center, San Francisco, CA
| | - Erika Castillo
- Department of Neurology, University of California San Francisco, San Francisco, CA.,Department of Neurology, San Francisco Veterans Affairs Medical Center, San Francisco, CA
| | - Elma S Frias
- Department of Neurology, University of California San Francisco, San Francisco, CA.,Department of Neurology, San Francisco Veterans Affairs Medical Center, San Francisco, CA
| | - Raymond A Swanson
- Department of Neurology, University of California San Francisco, San Francisco, CA.,Department of Neurology, San Francisco Veterans Affairs Medical Center, San Francisco, CA
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107
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Bazzigaluppi P, Ebrahim Amini A, Weisspapir I, Stefanovic B, Carlen PL. Hungry Neurons: Metabolic Insights on Seizure Dynamics. Int J Mol Sci 2017; 18:ijms18112269. [PMID: 29143800 PMCID: PMC5713239 DOI: 10.3390/ijms18112269] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 10/24/2017] [Accepted: 10/26/2017] [Indexed: 12/18/2022] Open
Abstract
Epilepsy afflicts up to 1.6% of the population and the mechanisms underlying the appearance of seizures are still not understood. In past years, many efforts have been spent trying to understand the mechanisms underlying the excessive and synchronous firing of neurons. Traditionally, attention was pointed towards synaptic (dys)function and extracellular ionic species (dys)regulation. Recently, novel clinical and preclinical studies explored the role of brain metabolism (i.e., glucose utilization) of seizures pathophysiology revealing (in most cases) reduced metabolism in the inter-ictal period and increased metabolism in the seconds preceding and during the appearance of seizures. In the present review, we summarize the clinical and preclinical observations showing metabolic dysregulation during epileptogenesis, seizure initiation, and termination, and in the inter-ictal period. Recent preclinical studies have shown that 2-Deoxyglucose (2-DG, a glycolysis blocker) is a novel therapeutic approach to reduce seizures. Furthermore, we present initial evidence for the effectiveness of 2-DG in arresting 4-Aminopyridine induced neocortical seizures in vivo in the mouse.
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Affiliation(s)
- Paolo Bazzigaluppi
- Krembil Research Institute, Fundamental Neurobiology, Toronto, ON M5T 2S8, Canada.
- Sunnybrook Research Institute, Medical Biophysics, Toronto, ON M4N 3M5, Canada.
| | - Azin Ebrahim Amini
- Krembil Research Institute, Fundamental Neurobiology, Toronto, ON M5T 2S8, Canada.
- Institute of Biomaterials & Biomedical Engineering (IBBME), University of Toronto, Toronto, ON M5S 3G9, Canada.
| | - Iliya Weisspapir
- Krembil Research Institute, Fundamental Neurobiology, Toronto, ON M5T 2S8, Canada.
| | - Bojana Stefanovic
- Sunnybrook Research Institute, Medical Biophysics, Toronto, ON M4N 3M5, Canada.
| | - Peter L Carlen
- Krembil Research Institute, Fundamental Neurobiology, Toronto, ON M5T 2S8, Canada.
- Department of Medicine & Physiology, and Institute of Biomaterials & Biomedical Engineering (IBBME), University of Toronto, Toronto, ON M5S 1A8, Canada.
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108
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Shehata HM, Murphy AJ, Lee MKS, Gardiner CM, Crowe SM, Sanjabi S, Finlay DK, Palmer CS. Sugar or Fat?-Metabolic Requirements for Immunity to Viral Infections. Front Immunol 2017; 8:1311. [PMID: 29085369 PMCID: PMC5649203 DOI: 10.3389/fimmu.2017.01311] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 09/28/2017] [Indexed: 12/20/2022] Open
Abstract
The realization that an intricate link exists between the metabolic state of immune cells and the nature of the elicited immune responses has brought a dramatic evolution to the field of immunology. We will focus on how metabolic reprogramming through the use of glycolysis and fatty-acid oxidation (sugar or fat) regulates the capacity of immune cells to mount robust and effective immune responses. We will also discuss how fine-tuning sugar and fat metabolism may be exploited as a novel immunotherapeutic strategy to fight viral infections or improve vaccine efficacy.
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Affiliation(s)
- Hesham M Shehata
- Virology and Immunology, Gladstone Institutes, San Francisco, CA, United States
| | - Andrew J Murphy
- Haematopoiesis and Leukocyte Biology, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
| | - Man Kit Sam Lee
- Haematopoiesis and Leukocyte Biology, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
| | - Clair M Gardiner
- School of Biochemistry and Immunology, Trinity College Dublin, Trinity Biomedical Sciences Institute, Dublin, Ireland
| | - Suzanne M Crowe
- Centre for Biomedical Research, Burnet Institute, Melbourne, VIC, Australia.,Department of Infectious Diseases, Monash University, Melbourne, VIC, Australia
| | - Shomyseh Sanjabi
- Virology and Immunology, Gladstone Institutes, San Francisco, CA, United States
| | - David K Finlay
- School of Biochemistry and Immunology, Trinity College Dublin, Trinity Biomedical Sciences Institute, Dublin, Ireland
| | - Clovis Steve Palmer
- Centre for Biomedical Research, Burnet Institute, Melbourne, VIC, Australia.,Department of Infectious Diseases, Monash University, Melbourne, VIC, Australia.,Department of Microbiology and Immunology, University of Melbourne, Melbourne, VIC, Australia
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109
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MacFarlane PM, Vinit S, Mitchell GS. Enhancement of phrenic long-term facilitation following repetitive acute intermittent hypoxia is blocked by the glycolytic inhibitor 2-deoxyglucose. Am J Physiol Regul Integr Comp Physiol 2017; 314:R135-R144. [PMID: 29021191 DOI: 10.1152/ajpregu.00306.2017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Moderate acute intermittent hypoxia (mAIH) elicits a form of respiratory motor plasticity known as phrenic long-term facilitation (pLTF). Preconditioning with modest protocols of chronic intermittent hypoxia enhances pLTF, demonstrating pLTF metaplasticity. Since "low-dose" protocols of repetitive acute intermittent hypoxia (rAIH) show promise as a therapeutic modality to restore respiratory (and nonrespiratory) motor function in clinical disorders with compromised breathing, we tested 1) whether preconditioning with a mild rAIH protocol enhances pLTF and hypoglossal (XII) LTF and 2) whether the enhancement is regulated by glycolytic flux. In anesthetized, paralyzed, and ventilated adult male Lewis rats, mAIH (three 5-min episodes of 10% O2) elicited pLTF (pLTF at 60 min post-mAIH: 49 ± 5% baseline). rAIH preconditioning (ten 5-min episodes of 11% O2/day with 5-min normoxic intervals, 3 times per week, for 4 wk) significantly enhanced pLTF (100 ± 16% baseline). XII LTF was unaffected by rAIH. When glycolytic flux was inhibited by 2-deoxy-d-glucose (2-DG) administered via drinking water (~80 mg·kg-1·day-1), pLTF returned to normal levels (58 ± 8% baseline); 2-DG had no effect on pLTF in normoxia-pretreated rats (59 ± 7% baseline). In ventral cervical (C4/5) spinal homogenates, rAIH increased inducible nitric oxide synthase mRNA vs. normoxic controls, an effect blocked by 2-DG. However, there were no detectable effects of rAIH or 2-DG on several molecules associated with phrenic motor plasticity, including serotonin 2A, serotonin 7, brain-derived neurotrophic factor, tropomyosin receptor kinase B, or VEGF mRNA. We conclude that modest, but prolonged, rAIH elicits pLTF metaplasticity and that a drug known to inhibit glycolytic flux (2-DG) blocks pLTF enhancement.
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Affiliation(s)
- P M MacFarlane
- Department of Comparative Biosciences, University of Wisconsin , Madison, Wisconsin.,Department of Pediatrics, Case Western Reserve University, Rainbow Babies & Children's Hospital , Cleveland, Ohio
| | - S Vinit
- Department of Comparative Biosciences, University of Wisconsin , Madison, Wisconsin.,Université de Versailles Saint-Quentin-en-Yvelines, INSERM U1179 END-ICAP, UFR des Sciences de la Santé-Simone Veil, Montigny-le-Bretonneux, France
| | - G S Mitchell
- Department of Comparative Biosciences, University of Wisconsin , Madison, Wisconsin.,Center for Respiratory Research and Rehabilitation, Department of Physical Therapy and McKnight Brain Institute, University of Florida , Gainesville, Florida
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110
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Bioenergetic state regulates innate inflammatory responses through the transcriptional co-repressor CtBP. Nat Commun 2017; 8:624. [PMID: 28935892 PMCID: PMC5608947 DOI: 10.1038/s41467-017-00707-0] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2014] [Accepted: 07/21/2017] [Indexed: 01/04/2023] Open
Abstract
The innate inflammatory response contributes to secondary injury in brain trauma and other disorders. Metabolic factors such as caloric restriction, ketogenic diet, and hyperglycemia influence the inflammatory response, but how this occurs is unclear. Here, we show that glucose metabolism regulates pro-inflammatory NF-κB transcriptional activity through effects on the cytosolic NADH:NAD+ ratio and the NAD(H) sensitive transcriptional co-repressor CtBP. Reduced glucose availability reduces the NADH:NAD+ ratio, NF-κB transcriptional activity, and pro-inflammatory gene expression in macrophages and microglia. These effects are inhibited by forced elevation of NADH, reduced expression of CtBP, or transfection with an NAD(H) insensitive CtBP, and are replicated by a synthetic peptide that inhibits CtBP dimerization. Changes in the NADH:NAD+ ratio regulate CtBP binding to the acetyltransferase p300, and regulate binding of p300 and the transcription factor NF-κB to pro-inflammatory gene promoters. These findings identify a mechanism by which alterations in cellular glucose metabolism can influence cellular inflammatory responses. Several metabolic factors affect cellular glucose metabolism as well as the innate inflammatory response. Here, the authors show that glucose metabolism regulates pro-inflammatory responses through effects on the cytosolic NADH:NAD+ ratio and the NAD(H)-sensitive transcription co-repressor CtBP.
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111
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Pecoraro-Bisogni F, Lignani G, Contestabile A, Castroflorio E, Pozzi D, Rocchi A, Prestigio C, Orlando M, Valente P, Massacesi M, Benfenati F, Baldelli P. REST-Dependent Presynaptic Homeostasis Induced by Chronic Neuronal Hyperactivity. Mol Neurobiol 2017; 55:4959-4972. [PMID: 28786015 DOI: 10.1007/s12035-017-0698-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 07/26/2017] [Indexed: 10/19/2022]
Abstract
Homeostatic plasticity is a regulatory feedback response in which either synaptic strength or intrinsic excitability can be adjusted up or down to offset sustained changes in neuronal activity. Although a growing number of evidences constantly provide new insights into these two apparently distinct homeostatic processes, a unified molecular model remains unknown. We recently demonstrated that REST is a transcriptional repressor critical for the downscaling of intrinsic excitability in cultured hippocampal neurons subjected to prolonged elevation of electrical activity. Here, we report that, in the same experimental system, REST also participates in synaptic homeostasis by reducing the strength of excitatory synapses by specifically acting at the presynaptic level. Indeed, chronic hyperactivity triggers a REST-dependent decrease of the size of synaptic vesicle pools through the transcriptional and translational repression of specific presynaptic REST target genes. Together with our previous report, the data identify REST as a fundamental molecular player for neuronal homeostasis able to downscale simultaneously both intrinsic excitability and presynaptic efficiency in response to elevated neuronal activity. This experimental evidence adds new insights to the complex activity-dependent transcriptional regulation of the homeostatic plasticity processes mediated by REST.
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Affiliation(s)
- F Pecoraro-Bisogni
- Department of Experimental Medicine, Section of Physiology, University of Genova, Viale Benedetto XV 3, 16132, Genoa, Italy.,Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132, Genoa, Italy
| | - Gabriele Lignani
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132, Genoa, Italy. .,Institute of Neurology, University College of London, WC1N 3BG, London, UK.
| | - A Contestabile
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132, Genoa, Italy
| | - E Castroflorio
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132, Genoa, Italy
| | - D Pozzi
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132, Genoa, Italy.,Pharmacology and Brain Pathology Lab, Humanitas Clinical and Research Center, Humanitas University, Via Manzoni 56, Rozzano, Milan, Italy
| | - A Rocchi
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132, Genoa, Italy
| | - C Prestigio
- Department of Experimental Medicine, Section of Physiology, University of Genova, Viale Benedetto XV 3, 16132, Genoa, Italy.,Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132, Genoa, Italy
| | - M Orlando
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132, Genoa, Italy.,Neurocure NWFZ, Charite Universitaetsmedizin Berlin, Chariteplatz 1, 10117, Berlin, Germany
| | - P Valente
- Department of Experimental Medicine, Section of Physiology, University of Genova, Viale Benedetto XV 3, 16132, Genoa, Italy
| | - M Massacesi
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132, Genoa, Italy.,Laboratory of Neurosciences and Neurogenetics, Department of Head and Neck Diseases, "G. Gaslini" Institute, Via Gerolamo Gaslini 5, 16147, Genoa, Italy
| | - F Benfenati
- Department of Experimental Medicine, Section of Physiology, University of Genova, Viale Benedetto XV 3, 16132, Genoa, Italy.,Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132, Genoa, Italy
| | - Pietro Baldelli
- Department of Experimental Medicine, Section of Physiology, University of Genova, Viale Benedetto XV 3, 16132, Genoa, Italy. .,Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132, Genoa, Italy.
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112
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Clossen BL, Reddy DS. Novel therapeutic approaches for disease-modification of epileptogenesis for curing epilepsy. Biochim Biophys Acta Mol Basis Dis 2017; 1863:1519-1538. [PMID: 28179120 PMCID: PMC5474195 DOI: 10.1016/j.bbadis.2017.02.003] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 01/31/2017] [Accepted: 02/03/2017] [Indexed: 11/16/2022]
Abstract
This article describes the recent advances in epileptogenesis and novel therapeutic approaches for the prevention of epilepsy, with a special emphasis on the pharmacological basis of disease-modification of epileptogenesis for curing epilepsy. Here we assess animal studies and human clinical trials of epilepsy spanning 1982-2016. Epilepsy arises from a number of neuronal factors that trigger epileptogenesis, which is the process by which a brain shifts from a normal physiologic state to an epileptic condition. The events precipitating these changes can be of diverse origin, including traumatic brain injury, cerebrovascular damage, infections, chemical neurotoxicity, and emergency seizure conditions such as status epilepticus. Expectedly, the molecular and system mechanisms responsible for epileptogenesis are not well defined or understood. To date, there is no approved therapy for the prevention of epilepsy. Epigenetic dysregulation, neuroinflammation, and neurodegeneration appear to trigger epileptogenesis. Targeted drugs are being identified that can truly prevent the development of epilepsy in at-risk people. The promising agents include rapamycin, COX-2 inhibitors, TRK inhibitors, epigenetic modulators, JAK-STAT inhibitors, and neurosteroids. Recent evidence suggests that neurosteroids may play a role in modulating epileptogenesis. A number of promising drugs are under investigation for the prevention or modification of epileptogenesis to halt the development of epilepsy. Some drugs in development appear rational for preventing epilepsy because they target the initial trigger or related signaling pathways as the brain becomes progressively more prone to seizures. Additional research into the target validity and clinical investigation is essential to make new frontiers in curing epilepsy.
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Affiliation(s)
- Bryan L Clossen
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, TX 77807, USA
| | - Doodipala Samba Reddy
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, TX 77807, USA.
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113
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Dcona MM, Morris BL, Ellis KC, Grossman SR. CtBP- an emerging oncogene and novel small molecule drug target: Advances in the understanding of its oncogenic action and identification of therapeutic inhibitors. Cancer Biol Ther 2017; 18:379-391. [PMID: 28532298 PMCID: PMC5536941 DOI: 10.1080/15384047.2017.1323586] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
C-terminal Binding Proteins (CtBP) 1 and 2 are oncogenic transcriptional co-regulators overexpressed in many cancer types, with their expression level correlating to worse prognostic outcomes and aggressive tumor features. CtBP negatively regulates the expression of many tumor suppressor genes, while coactivating genes that promote proliferation, epithelial-mesenchymal transition, and cancer stem cell self-renewal activity. In light of this evidence, the development of novel inhibitors that mitigate CtBP function may provide clinically actionable therapeutic tools. This review article focuses on the progress made in understanding CtBP structure, role in tumor progression, and discovery and development of CtBP inhibitors that target CtBP's dehydrogenase activity and other functions, with a focus on the theory and rationale behind the designs of current inhibitors. We provide insight into the future development and use of rational combination therapy that may further augment the efficacy of CtBP inhibitors, specifically addressing metastasis and cancer stem cell populations within tumors.
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Affiliation(s)
- M Michael Dcona
- a Department of Internal Medicine , Virginia Commonwealth University , Richmond , VA , USA
| | - Benjamin L Morris
- b Department of Human and Molecular Genetics , Virginia Commonwealth University , Richmond , VA , USA
| | - Keith C Ellis
- c Department of Medicinal Chemistry , Virginia Commonwealth University , Richmond , VA , USA.,d Institute for Structural Biology , Drug Discovery and Development, Virginia Commonwealth University , Richmond , VA , USA.,e VCU Massey Cancer Center , Virginia Commonwealth University , Richmond , VA , USA
| | - Steven R Grossman
- a Department of Internal Medicine , Virginia Commonwealth University , Richmond , VA , USA.,b Department of Human and Molecular Genetics , Virginia Commonwealth University , Richmond , VA , USA.,d Institute for Structural Biology , Drug Discovery and Development, Virginia Commonwealth University , Richmond , VA , USA.,e VCU Massey Cancer Center , Virginia Commonwealth University , Richmond , VA , USA
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114
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Zilberter Y, Zilberter M. The vicious circle of hypometabolism in neurodegenerative diseases: Ways and mechanisms of metabolic correction. J Neurosci Res 2017; 95:2217-2235. [PMID: 28463438 DOI: 10.1002/jnr.24064] [Citation(s) in RCA: 131] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 03/17/2017] [Accepted: 03/17/2017] [Indexed: 12/13/2022]
Abstract
Hypometabolism, characterized by decreased brain glucose consumption, is a common feature of many neurodegenerative diseases. Initial hypometabolic brain state, created by characteristic risk factors, may predispose the brain to acquired epilepsy and sporadic Alzheimer's and Parkinson's diseases, which are the focus of this review. Analysis of available data suggests that deficient glucose metabolism is likely a primary initiating factor for these diseases, and that resulting neuronal dysfunction further promotes the metabolic imbalance, establishing an effective positive feedback loop and a downward spiral of disease progression. Therefore, metabolic correction leading to the normalization of abnormalities in glucose metabolism may be an efficient tool to treat the neurological disorders by counteracting their primary pathological mechanisms. Published and preliminary experimental results on this approach for treating Alzheimer's disease and epilepsy models support the efficacy of metabolic correction, confirming the highly promising nature of the strategy. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Yuri Zilberter
- Aix-Marseille Université, INSERM UMR1106, Institut de Neurosciences des Systèmes, Marseille, France
| | - Misha Zilberter
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, California, 94158, USA
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115
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Shao LR, Stafstrom CE. Glycolytic inhibition by 2-deoxy-d-glucose abolishes both neuronal and network bursts in an in vitro seizure model. J Neurophysiol 2017; 118:103-113. [PMID: 28404824 DOI: 10.1152/jn.00100.2017] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 03/24/2017] [Accepted: 04/08/2017] [Indexed: 11/22/2022] Open
Abstract
Neuronal activity is energy demanding and coupled to cellular metabolism. In this study, we investigated the effects of glycolytic inhibition with 2-deoxy-d-glucose (2-DG) on basal membrane properties, spontaneous neuronal firing, and epileptiform network bursts in hippocampal slices. The effect of glycolytic inhibition on basal membrane properties was examined in hippocampal CA1 neurons, which are not ordinarily active spontaneously. Intracellular application of 2-DG did not significantly alter the membrane input resistance, action-potential threshold, firing pattern, or input-output relationship of these neurons compared with simultaneously recorded neighboring neurons without intracellular 2-DG. The effect of glycolytic inhibition on neuronal firing was tested in spontaneously active hippocampal neurons (CA3) when synaptic transmission was left intact or blocked with AMPA, NMDA, and GABAA receptor antagonists (DNQX, APV, and bicuculline, respectively). Under both conditions (synaptic activity intact or blocked), bath application of 2-DG (2 mM) blocked spontaneous firing in ~2/3 (67 and 71%, respectively) of CA3 pyramidal neurons. In contrast, neuronal firing of CA3 neurons persisted when 2-DG was applied intracellularly, suggesting that glycolytic inhibition of individual neurons is not sufficient to stop neuronal firing. The effects of 2-DG on epileptiform network bursts in area CA3 were tested in Mg2+-free medium containing 50 µM 4-aminopyridine. Bath application of 2-DG abolished these epileptiform bursts in a dose-dependent and all-or-none manner. Taken together, these data suggest that altered glucose metabolism profoundly affects cellular and network hyperexcitability and that glycolytic inhibition by 2-DG can effectively abrogate epileptiform activity.NEW & NOTEWORTHY Neuronal activity is highly energy demanding and coupled to cellular metabolism. In this study, we demonstrate that glycolytic inhibition with 2-deoxy-d-glucose (2-DG) effectively suppresses spontaneous neuronal firing and epileptiform bursts in hippocampal slices. These data suggest that an altered metabolic state can profoundly affect cellular and network excitability, and that the glycolytic inhibitor 2-DG may hold promise as a novel treatment of drug-resistant epilepsy.
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Affiliation(s)
- Li-Rong Shao
- Division of Pediatric Neurology, Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Carl E Stafstrom
- Division of Pediatric Neurology, Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland
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116
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Patterson KP, Barry JM, Curran MM, Singh-Taylor A, Brennan G, Rismanchi N, Page M, Noam Y, Holmes GL, Baram TZ. Enduring Memory Impairments Provoked by Developmental Febrile Seizures Are Mediated by Functional and Structural Effects of Neuronal Restrictive Silencing Factor. J Neurosci 2017; 37:3799-3812. [PMID: 28275159 PMCID: PMC5394897 DOI: 10.1523/jneurosci.3748-16.2017] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 02/25/2017] [Accepted: 02/28/2017] [Indexed: 12/22/2022] Open
Abstract
In a subset of children experiencing prolonged febrile seizures (FSs), the most common type of childhood seizures, cognitive outcomes are compromised. However, the underlying mechanisms are unknown. Here we identified significant, enduring spatial memory problems in male rats following experimental prolonged FS (febrile status epilepticus; eFSE). Remarkably, these deficits were abolished by transient, post hoc interference with the chromatin binding of the transcriptional repressor neuron restrictive silencing factor (NRSF or REST). This transcriptional regulator is known to contribute to neuronal differentiation during development and to programmed gene expression in mature neurons. The mechanisms of the eFSE-provoked memory problems involved complex disruption of memory-related hippocampal oscillations recorded from CA1, likely resulting in part from impairments of dendritic filtering of cortical inputs as well as abnormal synaptic function. Accordingly, eFSE provoked region-specific dendritic loss in the hippocampus, and aberrant generation of excitatory synapses in dentate gyrus granule cells. Blocking NRSF transiently after eFSE prevented granule cell dysmaturation, restored a functional balance of γ-band network oscillations, and allowed treated eFSE rats to encode and retrieve spatial memories. Together, these studies provide novel insights into developing networks that underlie memory, the mechanisms by which early-life seizures influence them, and the means to abrogate the ensuing cognitive problems.SIGNIFICANCE STATEMENT Whereas seizures have been the central focus of epilepsy research, they are commonly accompanied by cognitive problems, including memory impairments that contribute to poor quality of life. These deficits often arise before the onset of spontaneous seizures, or independent from them, yet the mechanisms involved are unclear. Here, using a rodent model of common developmental seizures that provoke epilepsy in a subset of individuals, we identify serious consequent memory problems. We uncover molecular, cellular, and circuit-level mechanisms that underlie these deficits and successfully abolish them by targeted therapeutic interventions. These findings may be important for understanding and preventing cognitive problems in individuals suffering long febrile seizures.
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Affiliation(s)
| | - Jeremy M Barry
- Department of Neurological Sciences, University of Vermont College of Medicine, Burlington, Vermont 05405
| | | | | | - Gary Brennan
- Departments of Anatomy/Neurobiology
- Pediatrics, and
| | | | - Matias Page
- Department of Neurological Sciences, University of Vermont College of Medicine, Burlington, Vermont 05405
| | | | - Gregory L Holmes
- Department of Neurological Sciences, University of Vermont College of Medicine, Burlington, Vermont 05405
| | - Tallie Z Baram
- Departments of Anatomy/Neurobiology,
- Pediatrics, and
- Neurology, University of California-Irvine, Irvine, California 92697-4475, and
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117
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Kadowaki A, Sada N, Juge N, Wakasa A, Moriyama Y, Inoue T. Neuronal inhibition and seizure suppression by acetoacetate and its analog, 2-phenylbutyrate. Epilepsia 2017; 58:845-857. [PMID: 28294308 DOI: 10.1111/epi.13718] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/08/2017] [Indexed: 12/26/2022]
Abstract
OBJECTIVE The ketogenic diet is clinically used to treat drug-resistant epilepsy. The diet treatment markedly increases ketone bodies (acetoacetate and β-hydroxybutyrate), which work as energy metabolites in the brain. Here, we investigated effects of acetoacetate on voltage-dependent Ca2+ channels (VDCCs) in pyramidal cells of the hippocampus. We further explored an acetoacetate analog that inhibited VDCCs in pyramidal cells, reduced excitatory postsynaptic currents (EPSCs), and suppressed seizures in vivo. METHODS The effects of acetoacetate and its analogs on VDCCs and EPSCs were evaluated using patch-clamp recordings from CA1 pyramidal cells of mouse hippocampal slices. The in vivo effects of these reagents were also evaluated using a chronic seizure model induced by intrahippocampal injection of kainate. RESULTS Acetoacetate inhibited VDCCs in pyramidal cells of hippocampal slices, and reduced EPSCs in slices exhibiting epileptiform activity. More potent EPSC inhibitors were then explored by modifying the chemical structure of acetoacetate, and 2-phenylbutyrate was identified as an acetoacetate analog that inhibited VDCCs and EPSCs more potently. Although acetoacetate is known to inhibit vesicular glutamate transporters (VGLUTs), 2-phenylbutyrate did not inhibit VGLUTs, showing that 2-phenylbutyrate is an acetoacetate analog that preferably inhibits VDCCs. In addition, 2-phenylbutyrate markedly reduced EPSCs in slices exhibiting epileptiform activity, and suppressed hippocampal seizures in vivo in a mouse model of epilepsy. The in vivo antiseizure effects of 2-phenylbutyrate were more potent than those of acetoacetate. Finally, intraperitoneal 2-phenylbutyrate was delivered to the brain, and its brain concentration reached the level enough to reduce EPSCs. SIGNIFICANCE These results demonstrate that 2-phenylbutyrate is an acetoacetate analog that inhibits VDCCs and EPSCs in pyramidal cells, suppresses hippocampal seizures in vivo, and has brain penetration ability. Thus 2-phenylbutyrate provides a useful chemical structure as a lead compound to develop new antiseizure drugs originating from ketone bodies.
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Affiliation(s)
- Atsushi Kadowaki
- Department of Biophysical Chemistry, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Nagisa Sada
- Department of Biophysical Chemistry, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Narinobu Juge
- Advanced Science Research Center, Okayama University, Okayama, Japan.,Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Tokyo, Japan
| | - Ayaka Wakasa
- Department of Biophysical Chemistry, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Yoshinori Moriyama
- Advanced Science Research Center, Okayama University, Okayama, Japan.,Department of Membrane Biochemistry, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Tsuyoshi Inoue
- Department of Biophysical Chemistry, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
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118
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Katsu-Jiménez Y, Alves RMP, Giménez-Cassina A. Food for thought: Impact of metabolism on neuronal excitability. Exp Cell Res 2017; 360:41-46. [PMID: 28263755 DOI: 10.1016/j.yexcr.2017.03.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 02/28/2017] [Accepted: 03/01/2017] [Indexed: 12/11/2022]
Abstract
Neuronal excitability is a highly demanding process that requires high amounts of energy and needs to be exquisitely regulated. For this reason, brain cells display active energy metabolism to support their activity. Independently of their roles as energy substrates, compelling evidence shows that the nature of the fuels that neurons use contribute to fine-tune neuronal excitability. Crosstalk of neurons with glial populations also plays a prominent role in shaping metabolic flow in the brain. In this review, we provide an overview on how different carbon substrates and metabolic pathways impact neurotransmission, and the potential implications for neurological disorders in which neuronal excitability is deregulated, such as epilepsy.
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Affiliation(s)
- Yurika Katsu-Jiménez
- Karolinska Institutet, Department of Medical Biochemistry and Biophysics, Scheeles väg 2, 171 77 Stockholm, Sweden
| | - Renato M P Alves
- Karolinska Institutet, Department of Medical Biochemistry and Biophysics, Scheeles väg 2, 171 77 Stockholm, Sweden
| | - Alfredo Giménez-Cassina
- Karolinska Institutet, Department of Medical Biochemistry and Biophysics, Scheeles väg 2, 171 77 Stockholm, Sweden; Centro de Biología Molecular "Severo Ochoa", Universidad Autónoma de Madrid, Department of Molecular Biology, C/ Nicolás Cabrera 1, 28049 Madrid, Spain.
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119
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Martin D, Grapin-Botton A. The Importance of REST for Development and Function of Beta Cells. Front Cell Dev Biol 2017; 5:12. [PMID: 28286748 PMCID: PMC5323410 DOI: 10.3389/fcell.2017.00012] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 02/07/2017] [Indexed: 01/10/2023] Open
Abstract
Beta cells are defined by the genes they express, many of which are specific to this cell type, and ensure a specific set of functions. Beta cells are also defined by a set of genes they should not express (in order to function properly), and these genes have been called forbidden genes. Among these, the transcriptional repressor RE-1 Silencing Transcription factor (REST) is expressed in most cells of the body, excluding most populations of neurons, as well as pancreatic beta and alpha cells. In the cell types where it is expressed, REST represses the expression of hundreds of genes that are crucial for both neuronal and pancreatic endocrine function, through the recruitment of multiple transcriptional and epigenetic co-regulators. REST targets include genes encoding transcription factors, proteins involved in exocytosis, synaptic transmission or ion channeling, and non-coding RNAs. REST is expressed in the progenitors of both neurons and beta cells during development, but it is down-regulated as the cells differentiate. Although REST mutations and deregulation have yet to be connected to diabetes in humans, REST activation during both development and in adult beta cells leads to diabetes in mice.
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Affiliation(s)
- David Martin
- Service of Cardiology, Centre Hospitalier Universitaire Vaudois (CHUV) Lausanne, Switzerland
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120
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Cheng N, Rho JM, Masino SA. Metabolic Dysfunction Underlying Autism Spectrum Disorder and Potential Treatment Approaches. Front Mol Neurosci 2017; 10:34. [PMID: 28270747 PMCID: PMC5318388 DOI: 10.3389/fnmol.2017.00034] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 01/30/2017] [Indexed: 12/14/2022] Open
Abstract
Autism spectrum disorder (ASD) is characterized by deficits in sociability and communication, and increased repetitive and/or restrictive behaviors. While the etio-pathogenesis of ASD is unknown, clinical manifestations are diverse and many possible genetic and environmental factors have been implicated. As such, it has been a great challenge to identify key neurobiological mechanisms and to develop effective treatments. Current therapies focus on co-morbid conditions (such as epileptic seizures and sleep disturbances) and there is no cure for the core symptoms. Recent studies have increasingly implicated mitochondrial dysfunction in ASD. The fact that mitochondria are an integral part of diverse cellular functions and are susceptible to many insults could explain how a wide range of factors can contribute to a consistent behavioral phenotype in ASD. Meanwhile, the high-fat, low-carbohydrate ketogenic diet (KD), used for nearly a century to treat medically intractable epilepsy, has been shown to enhance mitochondrial function through a multiplicity of mechanisms and affect additional molecular targets that may address symptoms and comorbidities of ASD. Here, we review the evidence for the use of metabolism-based therapies such as the KD in the treatment of ASD as well as emerging co-morbid models of epilepsy and autism. Future research directions aimed at validating such therapeutic approaches and identifying additional and novel mechanistic targets are also discussed.
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Affiliation(s)
- Ning Cheng
- Departments of Pediatrics, University of CalgaryCalgary, AB, Canada
| | - Jong M. Rho
- Departments of Pediatrics, University of CalgaryCalgary, AB, Canada
- Clinical Neurosciences, University of CalgaryCalgary, AB, Canada
- Physiology and Pharmacology, Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of CalgaryCalgary, AB, Canada
| | - Susan A. Masino
- Neuroscience Program, Department of Psychology, Trinity CollegeHartford, CT, USA
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121
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Samokhina E, Popova I, Malkov A, Ivanov AI, Papadia D, Osypov A, Molchanov M, Paskevich S, Fisahn A, Zilberter M, Zilberter Y. Chronic inhibition of brain glycolysis initiates epileptogenesis. J Neurosci Res 2017; 95:2195-2206. [PMID: 28150440 DOI: 10.1002/jnr.24019] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 12/20/2016] [Accepted: 12/21/2016] [Indexed: 12/30/2022]
Abstract
Metabolic abnormalities found in epileptogenic tissue provide considerable evidence of brain hypometabolism, while major risk factors for acquired epilepsy all share brain hypometabolism as one common outcome, suggesting that a breakdown of brain energy homeostasis may actually precede epileptogenesis. However, a causal link between deficient brain energy metabolism and epilepsy initiation has not been yet established. To address this issue we developed an in vivo model of chronic energy hypometabolism by daily intracerebroventricular (i.c.v.) injection of the nonmetabolizable glucose analog 2-deoxy-D-glucose (2-DG) and also investigated acute effects of 2-DG on the cellular level. In hippocampal slices, acute glycolysis inhibition by 2-DG (by about 35%) led to contrasting effects on the network: a downregulation of excitatory synaptic transmission together with a depolarization of neuronal resting potential and a decreased drive of inhibitory transmission. Therefore, the potential acute effect of 2-DG on network excitability depends on the balance between these opposing pre- and postsynaptic changes. In vivo, we found that chronic 2-DG i.c.v. application (estimated transient inhibition of brain glycolysis under 14%) for a period of 4 weeks induced epileptiform activity in initially healthy male rats. Our results suggest that chronic inhibition of brain energy metabolism, characteristics of the well-established risk factors of acquired epilepsy, and specifically a reduction in glucose utilization (typically observed in epileptic patients) can initiate epileptogenesis. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Evgeniya Samokhina
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Russia
| | - Irina Popova
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Russia
- Aix Marseille Université, Inserm, INS UMR_S 1106, 13005, Marseille, France
| | - Anton Malkov
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Russia
- Aix Marseille Université, Inserm, INS UMR_S 1106, 13005, Marseille, France
| | - Anton I Ivanov
- Aix Marseille Université, Inserm, INS UMR_S 1106, 13005, Marseille, France
| | - Daniela Papadia
- Neuronal Oscillations Lab, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Alexander Osypov
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russia
| | - Maxim Molchanov
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Russia
| | - Svetlana Paskevich
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Russia
| | - André Fisahn
- Neuronal Oscillations Lab, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Misha Zilberter
- Neuronal Oscillations Lab, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Yuri Zilberter
- Aix Marseille Université, Inserm, INS UMR_S 1106, 13005, Marseille, France
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122
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Bialer M, Johannessen SI, Levy RH, Perucca E, Tomson T, White HS. Progress report on new antiepileptic drugs: A summary of the Thirteenth Eilat Conference on New Antiepileptic Drugs and Devices (EILAT XIII). Epilepsia 2017; 58:181-221. [PMID: 28111749 DOI: 10.1111/epi.13634] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/07/2016] [Indexed: 01/05/2023]
Abstract
The Thirteenth Eilat Conference on New Antiepileptic Drugs and Devices (EILAT XIII) took place in Madrid, Spain, on June 26-29, 2016, and was attended by >200 delegates from 31 countries. The present Progress Report provides an update on experimental and clinical results for drugs presented at the Conference. Compounds for which summary data are presented include an AED approved in 2016 (brivaracetam), 12 drugs in phase I-III clinical development (adenosine, allopregnanolone, bumetanide, cannabidiol, cannabidivarin, 2-deoxy-d-glucose, everolimus, fenfluramine, huperzine A, minocycline, SAGE-217, and valnoctamide) and 6 compounds or classes of compounds for which only preclinical data are available (bumetanide derivatives, sec-butylpropylacetamide, FV-082, 1OP-2198, NAX 810-2, and SAGE-689). Overall, the results presented at the Conference show that considerable efforts are ongoing into discovery and development of AEDs with potentially improved therapeutic profiles compared with existing agents. Many of the drugs discussed in this report show innovative mechanisms of action and many have shown promising results in patients with pharmacoresistant epilepsies, including previously neglected rare and severe epilepsy syndromes.
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Affiliation(s)
- Meir Bialer
- Faculty of Medicine, School of Pharmacy and David R. Bloom Center for Pharmacy, Institute for Drug Research, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Svein I Johannessen
- The National Center for Epilepsy, Sandvika, Norway.,Department of Pharmacology, Oslo University Hospital, Oslo, Norway
| | - René H Levy
- Department of Pharmaceutics and Neurological Surgery, University of Washington, Seattle, Washington, U.S.A
| | - Emilio Perucca
- Department of Internal Medicine and Therapeutics, University of Pavia, Pavia, Italy.,C. Mondino National Neurological Institute, Pavia, Italy
| | - Torbjörn Tomson
- Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - H Steve White
- Department of Pharmacy, School of Pharmacy, University of Washington, Seattle, Washington, U.S.A
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123
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Brennan GP, Henshall DC. microRNAs in the pathophysiology of epilepsy. Neurosci Lett 2017; 667:47-52. [PMID: 28104433 DOI: 10.1016/j.neulet.2017.01.017] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 01/06/2017] [Accepted: 01/08/2017] [Indexed: 12/12/2022]
Abstract
Temporal lobe epilepsy is a common and often drug-resistant seizure disorder. The underlying pathological processes which give rise to the development of spontaneous seizures include neuroinflammation, cell loss, neurogenesis and dendritic abnormalities and many of these are driven by insult-induced changes in gene expression and gene expression regulation. MicroRNAs are powerful modulators of post-transcriptional gene expression which are dysregulated during epileptogenesis. The advent of locked nucleic acid (LNA) based inhibitory methods and mimic technology has facilitated in vivo functional assessment of these molecules in epilepsy. Here we review recent advances in our understanding of the role of these short non-coding RNAs in the pathophysiology of epilepsy.
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Affiliation(s)
- Gary P Brennan
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland,123 St. Stephens Green, Dublin D02 YN77, Ireland
| | - David C Henshall
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland,123 St. Stephens Green, Dublin D02 YN77, Ireland.
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124
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Velíšek L. Taming the rAMPAnt Fire with Fat. Epilepsy Curr 2017; 17:54-56. [PMID: 28331475 PMCID: PMC5340561 DOI: 10.5698/1535-7511-17.1.54] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2024] Open
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125
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Hall AM, Brennan GP, Nguyen TM, Singh-Taylor A, Mun HS, Sargious MJ, Baram TZ. The Role of Sirt1 in Epileptogenesis. eNeuro 2017; 4:ENEURO.0301-16.2017. [PMID: 28197553 PMCID: PMC5301079 DOI: 10.1523/eneuro.0301-16.2017] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 01/21/2017] [Accepted: 01/22/2017] [Indexed: 01/08/2023] Open
Abstract
The mechanisms by which brain insults lead to subsequent epilepsy remain unclear. Insults, including trauma, stroke, tumors, infections, and long seizures [status epilepticus (SE)], create a neuronal state of increased metabolic demand or decreased energy supply. Neurons express molecules that monitor their metabolic state, including sirtuins (Sirts). Sirtuins deacetylate cytoplasmic proteins and nuclear histones, and their epigenetic modulation of the chromatin governs the expression of many genes, influencing neuronal properties. Thus, sirtuins are poised to enduringly modulate neuronal properties following SE, potentially contributing to epileptogenesis, a hypothesis supported by the epilepsy-attenuating effects of blocking a downstream target of Sirt1, Neuron-Restrictive Silencer Factor (NRSF) also know as REST (RE1-Silencing Transcription factor). Here we used an adult male rat model of epileptogenesis provoked by kainic acid-induced SE (KA-SE). We assessed KA-SE-provoked Sirt1 activity, infused a Sirt1 inhibitor (EX-527) after KA-SE, and examined for epileptogenesis using continuous digital video-EEG. Sirt1 activity, measured using chromatin immunoprecipitation for Sirt1 binding at a target gene, increased rapidly after SE. Post hoc infusion of the Sirt1 inhibitor prevented Sirt1-mediated repression of a target gene. Blocking Sirt1 activity transiently after KA-SE did not significantly influence the time- course and all of the parameters of epilepsy development. Specifically, latency to first seizure and seizure number, duration, and severity (using the Racine scale and EEG measures) as well as the frequency and duration of interictal spike series, were all unchanged. KA-SE provoked a robust inflammatory response and modest cell loss, yet neither was altered by blocking Sirt1. In conclusion, blocking Sirt1 activity after KA-SE does not abrogate epilepsy development, suggesting that the mechanisms of such acquired epileptogenesis are independent of Sirt1 function.
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Affiliation(s)
- Alicia M. Hall
- Department of Pediatrics, University of California, Irvine, Irvine, California 92697
| | - Gary P. Brennan
- Department of Pediatrics, University of California, Irvine, Irvine, California 92697
- Department of Anatomy and Neurobiology, University of California, Irvine, Irvine, California 92697
| | - Tiffany M. Nguyen
- Department of Pediatrics, University of California, Irvine, Irvine, California 92697
| | - Akanksha Singh-Taylor
- Department of Pediatrics, University of California, Irvine, Irvine, California 92697
| | - Hyun-Seung Mun
- Department of Pediatrics, University of California, Irvine, Irvine, California 92697
| | - Mary J. Sargious
- Department of Pediatrics, University of California, Irvine, Irvine, California 92697
| | - Tallie Z. Baram
- Department of Pediatrics, University of California, Irvine, Irvine, California 92697
- Department of Anatomy and Neurobiology, University of California, Irvine, Irvine, California 92697
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126
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Rusconi F, Grillo B, Toffolo E, Mattevi A, Battaglioli E. NeuroLSD1: Splicing-Generated Epigenetic Enhancer of Neuroplasticity. Trends Neurosci 2017; 40:28-38. [DOI: 10.1016/j.tins.2016.11.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 11/18/2016] [Indexed: 12/17/2022]
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127
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Kalsbeek MJT, Mulder L, Yi CX. Microglia energy metabolism in metabolic disorder. Mol Cell Endocrinol 2016; 438:27-35. [PMID: 27687525 DOI: 10.1016/j.mce.2016.09.028] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 09/23/2016] [Accepted: 09/26/2016] [Indexed: 12/22/2022]
Abstract
Microglia are the resident macrophages of the CNS, and are in charge of maintaining a healthy microenvironment to ensure neuronal survival. Microglia carry out a non-stop patrol of the CNS, make contact with neurons and look for abnormalities, all of which requires a vast amount of energy. This non-signaling energy demand increases after activation by pathogens, neuronal damage or other kinds of stimulation. Of the three major energy substrates - glucose, fatty acids and glutamine - glucose is crucial for microglia survival and several glucose transporters are expressed to supply sufficient glucose influx. Fatty acids are another source of energy for microglia and have also been shown to strongly influence microglial immune activity. Glutamine, although possibly suitable for use as an energy substrate by microglia, has been shown to have neurotoxic effects when overloaded. Microglial fuel metabolism might be associated with microglial reactivity under different pathophysiological conditions and a microglial fuel switch may thus be the underlying cause of hypothalamic dysregulation, which is associated with obesity.
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Affiliation(s)
- Martin J T Kalsbeek
- Department of Endocrinology and Metabolism, Academic Medical Center (AMC), University of Amsterdam (UvA), Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
| | - Laurie Mulder
- Department of Endocrinology and Metabolism, Academic Medical Center (AMC), University of Amsterdam (UvA), Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - Chun-Xia Yi
- Department of Endocrinology and Metabolism, Academic Medical Center (AMC), University of Amsterdam (UvA), Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
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128
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Ranftler C, Meisslitzer-Ruppitsch C, Neumüller J, Ellinger A, Pavelka M. Golgi apparatus dis- and reorganizations studied with the aid of 2-deoxy-D-glucose and visualized by 3D-electron tomography. Histochem Cell Biol 2016; 147:415-438. [PMID: 27975144 PMCID: PMC5359389 DOI: 10.1007/s00418-016-1515-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/07/2016] [Indexed: 12/31/2022]
Abstract
We studied Golgi apparatus disorganizations and reorganizations in human HepG2 hepatoblastoma cells by using the nonmetabolizable glucose analogue 2-deoxy-d-glucose (2DG) and analyzing the changes in Golgi stack architectures by 3D-electron tomography. Golgi stacks remodel in response to 2DG-treatment and are replaced by tubulo-glomerular Golgi bodies, from which mini-Golgi stacks emerge again after removal of 2DG. The Golgi stack changes correlate with the measured ATP-values. Our findings indicate that the classic Golgi stack architecture is impeded, while cells are under the influence of 2DG at constantly low ATP-levels, but the Golgi apparatus is maintained in forms of the Golgi bodies and Golgi stacks can be rebuilt as soon as 2DG is removed. The 3D-electron microscopic results highlight connecting regions that interlink membrane compartments in all phases of Golgi stack reorganizations and show that the compact Golgi bodies mainly consist of continuous intertwined tubules. Connections and continuities point to possible new transport pathways that could substitute for other modes of traffic. The changing architectures visualized in this work reflect Golgi stack dynamics that may be essential for basic cell physiologic and pathologic processes and help to learn, how cells respond to conditions of stress.
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Affiliation(s)
- Carmen Ranftler
- Center for Anatomy and Cell Biology, Medical University of Vienna, Schwarzspanierstraße 17, 1090, Vienna, Austria
| | | | - Josef Neumüller
- Center for Anatomy and Cell Biology, Medical University of Vienna, Schwarzspanierstraße 17, 1090, Vienna, Austria
| | - Adolf Ellinger
- Center for Anatomy and Cell Biology, Medical University of Vienna, Schwarzspanierstraße 17, 1090, Vienna, Austria
| | - Margit Pavelka
- Center for Anatomy and Cell Biology, Medical University of Vienna, Schwarzspanierstraße 17, 1090, Vienna, Austria.
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129
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Delahaye-Duriez A, Srivastava P, Shkura K, Langley SR, Laaniste L, Moreno-Moral A, Danis B, Mazzuferi M, Foerch P, Gazina EV, Richards K, Petrou S, Kaminski RM, Petretto E, Johnson MR. Rare and common epilepsies converge on a shared gene regulatory network providing opportunities for novel antiepileptic drug discovery. Genome Biol 2016; 17:245. [PMID: 27955713 PMCID: PMC5154105 DOI: 10.1186/s13059-016-1097-7] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 11/02/2016] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND The relationship between monogenic and polygenic forms of epilepsy is poorly understood and the extent to which the genetic and acquired epilepsies share common pathways is unclear. Here, we use an integrated systems-level analysis of brain gene expression data to identify molecular networks disrupted in epilepsy. RESULTS We identified a co-expression network of 320 genes (M30), which is significantly enriched for non-synonymous de novo mutations ascertained from patients with monogenic epilepsy and for common variants associated with polygenic epilepsy. The genes in the M30 network are expressed widely in the human brain under tight developmental control and encode physically interacting proteins involved in synaptic processes. The most highly connected proteins within the M30 network were preferentially disrupted by deleterious de novo mutations for monogenic epilepsy, in line with the centrality-lethality hypothesis. Analysis of M30 expression revealed consistent downregulation in the epileptic brain in heterogeneous forms of epilepsy including human temporal lobe epilepsy, a mouse model of acquired temporal lobe epilepsy, and a mouse model of monogenic Dravet (SCN1A) disease. These results suggest functional disruption of M30 via gene mutation or altered expression as a convergent mechanism regulating susceptibility to epilepsy broadly. Using the large collection of drug-induced gene expression data from Connectivity Map, several drugs were predicted to preferentially restore the downregulation of M30 in epilepsy toward health, most notably valproic acid, whose effect on M30 expression was replicated in neurons. CONCLUSIONS Taken together, our results suggest targeting the expression of M30 as a potential new therapeutic strategy in epilepsy.
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Affiliation(s)
- Andree Delahaye-Duriez
- Division of Brain Sciences, Imperial College Faculty of Medicine, London, UK.
- MRC Clinical Sciences Centre, Imperial College London, London, UK.
- Université Paris 13, Sorbonne Paris Cité, UFR de Santé, Médecine et Biologie Humaine, Paris, France.
- PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France.
| | - Prashant Srivastava
- Division of Brain Sciences, Imperial College Faculty of Medicine, London, UK
| | - Kirill Shkura
- Division of Brain Sciences, Imperial College Faculty of Medicine, London, UK
| | - Sarah R Langley
- Division of Brain Sciences, Imperial College Faculty of Medicine, London, UK
- Duke-NUS Medical School, 8 College Road, 169857, Singapore, Republic of Singapore
| | - Liisi Laaniste
- Division of Brain Sciences, Imperial College Faculty of Medicine, London, UK
| | - Aida Moreno-Moral
- MRC Clinical Sciences Centre, Imperial College London, London, UK
- Duke-NUS Medical School, 8 College Road, 169857, Singapore, Republic of Singapore
| | - Bénédicte Danis
- Neuroscience TA, UCB Pharma, S.A, Allée de la Recherche, 60, 1070, Brussels, Belgium
| | - Manuela Mazzuferi
- Neuroscience TA, UCB Pharma, S.A, Allée de la Recherche, 60, 1070, Brussels, Belgium
| | - Patrik Foerch
- Neuroscience TA, UCB Pharma, S.A, Allée de la Recherche, 60, 1070, Brussels, Belgium
| | - Elena V Gazina
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, 3052, Australia
| | - Kay Richards
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, 3052, Australia
| | - Steven Petrou
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, 3052, Australia
- The Centre for Neural Engineering, The Department of Electrical Engineering, The University of Melbourne, Parkville, Victoria, 3052, Australia
- The Australian Research Council Centre of Excellence for Integrative Brain Function, Parkville, Victoria, 3052, Australia
| | - Rafal M Kaminski
- Neuroscience TA, UCB Pharma, S.A, Allée de la Recherche, 60, 1070, Brussels, Belgium
| | - Enrico Petretto
- MRC Clinical Sciences Centre, Imperial College London, London, UK.
- Duke-NUS Medical School, 8 College Road, 169857, Singapore, Republic of Singapore.
| | - Michael R Johnson
- Division of Brain Sciences, Imperial College Faculty of Medicine, London, UK.
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130
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Tefera TW, Tan KN, McDonald TS, Borges K. Alternative Fuels in Epilepsy and Amyotrophic Lateral Sclerosis. Neurochem Res 2016; 42:1610-1620. [PMID: 27868154 DOI: 10.1007/s11064-016-2106-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 11/08/2016] [Accepted: 11/09/2016] [Indexed: 12/12/2022]
Abstract
This review summarises the recent findings on metabolic treatments for epilepsy and Amyotrophic Lateral Sclerosis (ALS) in honour of Professor Ursula Sonnewald. The metabolic impairments in rodent models of these disorders as well as affected patients are being discussed. In both epilepsy and ALS, there are defects in glucose uptake and reduced tricarboxylic acid (TCA) cycling, at least in part due to reduced amounts of C4 TCA cycle intermediates. In addition there are impairments in glycolysis in ALS. A reduction in glucose uptake can be addressed by providing the brain with alternative fuels, such as ketones or medium-chain triglycerides. As anaplerotic fuels, such as the triglyceride of heptanoate, triheptanoin, refill the TCA cycle C4/C5 intermediate pool that is deficient, they are ideal to boost TCA cycling and thus the oxidative metabolism of all fuels.
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Affiliation(s)
- Tesfaye W Tefera
- Department of Pharmacology, School of Biomedical Sciences, The University of Queensland, Skerman Building 65, St Lucia, QLD, 4072, Australia
| | - Kah Ni Tan
- Department of Pharmacology, School of Biomedical Sciences, The University of Queensland, Skerman Building 65, St Lucia, QLD, 4072, Australia
| | - Tanya S McDonald
- Department of Pharmacology, School of Biomedical Sciences, The University of Queensland, Skerman Building 65, St Lucia, QLD, 4072, Australia
| | - Karin Borges
- Department of Pharmacology, School of Biomedical Sciences, The University of Queensland, Skerman Building 65, St Lucia, QLD, 4072, Australia.
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131
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Zhao Y, Yang Y. Real-time and high-throughput analysis of mitochondrial metabolic states in living cells using genetically encoded NAD +/NADH sensors. Free Radic Biol Med 2016; 100:43-52. [PMID: 27261194 DOI: 10.1016/j.freeradbiomed.2016.05.027] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 04/21/2016] [Accepted: 05/30/2016] [Indexed: 11/25/2022]
Abstract
Mitochondria are central organelles that regulate cellular bioenergetics, biosynthesis, and signaling processes. NADH, a key player in cell metabolism, is often considered as a marker of mitochondrial function. However, traditional methods for NADH measurements are either destructive or unable to distinguish between NADH and NADPH. In contrast to traditional methods, genetically encoded NADH sensors can be used for the real-time tracking and quantitative measurement of subcellular NADH levels in living cells. Therefore, these sensors provide innovative tools and address the limitations of current techniques. We herein summarize the properties of different types of recently developed NADH biosensors, discuss their advantages and disadvantages, and focus on the high-throughput analysis of mitochondrial function by using highly responsive NAD+/NADH sensors.
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Affiliation(s)
- Yuzheng Zhao
- Synthetic Biology and Biotechnology Laboratory, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China; Optogenetics & Synthetic Biology Interdisciplinary Research Center, CAS Center for Excellence in Brain Science, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China; Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China.
| | - Yi Yang
- Synthetic Biology and Biotechnology Laboratory, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China; Optogenetics & Synthetic Biology Interdisciplinary Research Center, CAS Center for Excellence in Brain Science, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China; Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China.
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132
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Forte N, Medrihan L, Cappetti B, Baldelli P, Benfenati F. 2-Deoxy-d-glucose enhances tonic inhibition through the neurosteroid-mediated activation of extrasynaptic GABA A receptors. Epilepsia 2016; 57:1987-2000. [PMID: 27735054 DOI: 10.1111/epi.13578] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/05/2016] [Indexed: 12/11/2022]
Abstract
OBJECTIVE The inhibition of glycolysis exerts potent antiseizure effects, as demonstrated by the efficacy of ketogenic and low-glucose/nonketogenic diets in the treatment of drug-resistant epilepsy. ATP-sensitive potassium (KATP ) channels have been initially identified as the main determinant of the reduction of neuronal hyperexcitability. However, a plethora of other mechanisms have been proposed. Herein, we report the ability of 2-deoxy-d-glucose (2-DG), a glucose analog that inhibits glycolytic enzymes, of potentiating γ-aminobutyric acid (GABA)ergic tonic inhibition via neurosteroid-mediated activation of extrasynaptic GABAA receptors. METHODS Acute effects of 2-DG on the ATP-sensitive potassium currents, GABAergic tonic inhibition, firing activity, and interictal events were assessed in hippocampal slices by whole-cell patch-clamp and local field potential recordings of dentate gyrus granule cells. RESULTS Acute application of 2-DG activates two distinct outward conductances: a KATP channel-mediated current and a bicuculline-sensitive tonic current. The effect of 2-DG on such GABAergic tonic currents was fully prevented by either finasteride or PK11195, which are specific inhibitors of the neurosteroidogenesis pathway acting via different mechanisms. Moreover, the oxidized form of vitamin C, dehydroascorbic acid, known for its ability to induce neurosteroidogenesis, also activated a bicuculline-sensitive tonic current in a manner indistinguishable from that of 2-DG. Finally, we found that the enhancement of KATP current by 2-DG primarily regulates intrinsic firing rate of granule cells, whereas the increase of the GABAergic tonic current plays a key role in reducing the frequency of interictal events evoked by treatment of hippocampal slices with the convulsive agent 4-aminopyridine. SIGNIFICANCE We demonstrated, for the first time, that 2-DG potentiates the extrasynaptic tonic GABAergic current through activation of neurosteroidogenesis. Such tonic inhibition represents the main conductance responsible for the antiseizure action of this glycolytic inhibitor.
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Affiliation(s)
- Nicola Forte
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova, Italy.,Department of Experimental Medicine, University of Genova, Genova, Italy
| | - Lucian Medrihan
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova, Italy
| | - Beatrice Cappetti
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova, Italy
| | - Pietro Baldelli
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova, Italy.,Department of Experimental Medicine, University of Genova, Genova, Italy
| | - Fabio Benfenati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova, Italy.,Department of Experimental Medicine, University of Genova, Genova, Italy
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133
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Abstract
Redox homeostasis is crucial for proper cellular functions, including receptor tyrosine kinase signaling, protein folding, and xenobiotic detoxification. Under basal conditions, there is a balance between oxidants and antioxidants. This balance facilitates the ability of oxidants, such as reactive oxygen species, to play critical regulatory functions through a direct modification of a small number of amino acids (e.g. cysteine) on signaling proteins. These signaling functions leverage tight spatial, amplitude, and temporal control of oxidant concentrations. However, when oxidants overwhelm the antioxidant capacity, they lead to a harmful condition of oxidative stress. Oxidative stress has long been held to be one of the key players in disease progression for Huntington's disease (HD). In this review, we will critically review this evidence, drawing some intermediate conclusions, and ultimately provide a framework for thinking about the role of oxidative stress in the pathophysiology of HD.
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Affiliation(s)
- Amit Kumar
- Burke Medical Research Institute, White Plains, NY, USA
- Brain and Mind Research Institute, Weill Medical College of Cornell University, New York, NY, USA
- Department of Neurology, Weill Medical College of Cornell University, New York, NY, USA
| | - Rajiv R. Ratan
- Burke Medical Research Institute, White Plains, NY, USA
- Brain and Mind Research Institute, Weill Medical College of Cornell University, New York, NY, USA
- Department of Neurology, Weill Medical College of Cornell University, New York, NY, USA
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134
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Control of seizures by ketogenic diet-induced modulation of metabolic pathways. Amino Acids 2016; 49:1-20. [PMID: 27683025 DOI: 10.1007/s00726-016-2336-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 09/16/2016] [Indexed: 12/22/2022]
Abstract
Epilepsy is too complex to be considered as a disease; it is more of a syndrome, characterized by seizures, which can be caused by a diverse array of afflictions. As such, drug interventions that target a single biological pathway will only help the specific individuals where that drug's mechanism of action is relevant to their disorder. Most likely, this will not alleviate all forms of epilepsy nor the potential biological pathways causing the seizures, such as glucose/amino acid transport, mitochondrial dysfunction, or neuronal myelination. Considering our current inability to test every individual effectively for the true causes of their epilepsy and the alarming number of misdiagnoses observed, we propose the use of the ketogenic diet (KD) as an effective and efficient preliminary/long-term treatment. The KD mimics fasting by altering substrate metabolism from carbohydrates to fatty acids and ketone bodies (KBs). Here, we underscore the need to understand the underlying cellular mechanisms governing the KD's modulation of various forms of epilepsy and how a diverse array of metabolites including soluble fibers, specific fatty acids, and functional amino acids (e.g., leucine, D-serine, glycine, arginine metabolites, and N-acetyl-cysteine) may potentially enhance the KD's ability to treat and reverse, not mask, these neurological disorders that lead to epilepsy.
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135
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The Risk Versus Reward of Targeting Epileptogenic Signaling Pathways via miRNA Replacement Therapy. Epilepsy Curr 2016; 16:263-5. [PMID: 27582670 DOI: 10.5698/1535-7511-16.4.263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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136
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Lu M, Zhu XH, Chen W. In vivo (31) P MRS assessment of intracellular NAD metabolites and NAD(+) /NADH redox state in human brain at 4 T. NMR IN BIOMEDICINE 2016; 29:1010-7. [PMID: 27257783 PMCID: PMC4909585 DOI: 10.1002/nbm.3559] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 03/21/2016] [Accepted: 04/12/2016] [Indexed: 05/16/2023]
Abstract
NAD(+) and NADH play key roles in cellular respiration. Intracellular redox state defined by the NAD(+) /NADH ratio (RX) reflects the cellular metabolic and physiopathological status. By taking advantage of high/ultrahigh magnetic field strengths, we have recently established a novel in vivo (31) P MRS-based NAD assay for noninvasive and quantitative measurements of intracellular NAD concentrations and redox state in animal and human brains at 16.4 T, 9.4 T and 7 T. To explore its potential for clinical application, in this study we investigated the feasibility of assessing the NAD metabolism and redox state in human brain at a lower field of 4 T by incorporating the (1) H-decoupling technique with the in vivo (31) P NAD assay. The use of (1) H decoupling significantly narrowed the linewidths of NAD and α-ATP resonances, resulting in higher sensitivity and better spectral resolution as compared with the (1) H-coupled (31) P spectrum. These improvements made it possible to reliably quantify cerebral NAD concentrations and RX, consistent with previously reported results obtained from similar age human subjects at 7 T. In summary, this work demonstrates the capability and utility of the (1) H-decoupled (31) P MRS-based NAD assay at lower field strength; thus, it opens new opportunities for studying intracellular NAD metabolism and redox state in human brain at clinical settings. This conclusion is supported by the simulation results, indicating that similar performance and reliability as observed at 4T can be achieved at 3 T with the same signal-to-noise ratio. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
| | - Xiao-Hong Zhu
- Correspondence to: Xiao-Hong Zhu, Ph.D., Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, 2012 6 Street S.E., Minneapolis, Minnesota 55455, USA,
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137
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Zhao Y, Wang A, Zou Y, Su N, Loscalzo J, Yang Y. In vivo monitoring of cellular energy metabolism using SoNar, a highly responsive sensor for NAD(+)/NADH redox state. Nat Protoc 2016; 11:1345-59. [PMID: 27362337 DOI: 10.1038/nprot.2016.074] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
NADH and its oxidized form NAD(+) have a central role in energy metabolism, and their concentrations are often considered to be among the most important readouts of metabolic state. Here, we present a detailed protocol to image and monitor NAD(+)/NADH redox state in living cells and in vivo using a highly responsive, genetically encoded fluorescent sensor known as SoNar (sensor of NAD(H) redox). The chimeric SoNar protein was initially developed by inserting circularly permuted yellow fluorescent protein (cpYFP) into the NADH-binding domain of Rex protein from Thermus aquaticus (T-Rex). It functions by binding to either NAD(+) or NADH, thus inducing protein conformational changes that affect its fluorescent properties. We first describe steps for how to establish SoNar-expressing cells, and then discuss how to use the system to quantify the intracellular redox state. This approach is sensitive, accurate, simple and able to report subtle perturbations of various pathways of energy metabolism in real time. We also detail the application of SoNar to high-throughput chemical screening of candidate compounds targeting cell metabolism in a microplate-reader-based assay, along with in vivo fluorescence imaging of tumor xenografts expressing SoNar in mice. Typically, the approximate time frame for fluorescence imaging of SoNar is 30 min for living cells and 60 min for living mice. For high-throughput chemical screening in a 384-well-plate assay, the whole procedure generally takes no longer than 60 min to assess the effects of 380 compounds on cell metabolism.
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Affiliation(s)
- Yuzheng Zhao
- Synthetic Biology and Biotechnology Laboratory, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, Shanghai, China.,Optogenetics &Molecular Imaging Interdisciplinary Research Center, CAS Center for Excellence in Brain Science, East China University of Science and Technology, Shanghai, China.,Collaborative Innovation Center of Genetics and Development, East China University of Science and Technology, Shanghai, China.,Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, Shanghai, China
| | - Aoxue Wang
- Synthetic Biology and Biotechnology Laboratory, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, Shanghai, China.,Optogenetics &Molecular Imaging Interdisciplinary Research Center, CAS Center for Excellence in Brain Science, East China University of Science and Technology, Shanghai, China.,Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, Shanghai, China
| | - Yejun Zou
- Synthetic Biology and Biotechnology Laboratory, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, Shanghai, China.,Optogenetics &Molecular Imaging Interdisciplinary Research Center, CAS Center for Excellence in Brain Science, East China University of Science and Technology, Shanghai, China.,Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, Shanghai, China
| | - Ni Su
- Synthetic Biology and Biotechnology Laboratory, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, Shanghai, China.,Optogenetics &Molecular Imaging Interdisciplinary Research Center, CAS Center for Excellence in Brain Science, East China University of Science and Technology, Shanghai, China.,Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, Shanghai, China
| | - Joseph Loscalzo
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Yi Yang
- Synthetic Biology and Biotechnology Laboratory, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, Shanghai, China.,Optogenetics &Molecular Imaging Interdisciplinary Research Center, CAS Center for Excellence in Brain Science, East China University of Science and Technology, Shanghai, China.,Collaborative Innovation Center of Genetics and Development, East China University of Science and Technology, Shanghai, China.,Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, Shanghai, China
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138
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Boone CHT, Grove RA, Adamcova D, Braga CP, Adamec J. Revealing oxidative damage to enzymes of carbohydrate metabolism in yeast: An integration of 2D DIGE, quantitative proteomics, and bioinformatics. Proteomics 2016; 16:1889-903. [PMID: 27193513 DOI: 10.1002/pmic.201500546] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 04/19/2016] [Accepted: 05/16/2016] [Indexed: 12/17/2022]
Abstract
Clinical usage of lidocaine, a pro-oxidant has been linked with severe, mostly neurological complications. The mechanism(s) causing these complications is independent of the blockade of voltage-gated sodium channels. The budding yeast Saccharomyces cerevisiae lacks voltage-gated sodium channels, thus provides an ideal system to investigate lidocaine-induced protein and pathway alterations. Whole-proteome alterations leading to these complications have not been identified. To address this, S. cerevisiae was grown to stationary phase and exposed to an LC50 dose of lidocaine. The differential proteomes of lidocaine treatment and control were resolved 6 h post exposure using 2D DIGE. Amine reactive dyes and carbonyl reactive dyes were used to assess protein abundance and protein oxidation, respectively. Quantitative analysis of these dyes (⩾ 1.5-fold alteration, p ⩽ 0.05) revealed a total of 33 proteoforms identified by MS differing in abundance and/or oxidation upon lidocaine exposure. Network analysis showed enrichment of apoptotic proteins and cell wall maintenance proteins, while the abundance of proteins central to carbohydrate metabolism, such as triosephosphate isomerase and glyceraldehyde-3-phosphate dehydrogenase, and redox proteins superoxide dismutase and peroxiredoxin were significantly decreased. Enzymes of carbohydrate metabolism, such as phosphoglycerate kinase and enolase, the TCA cycle enzyme aconitase, and multiple ATP synthase subunits were found to be oxidatively modified. Also, the activity of aconitase was found to be decreased. Overall, these data suggest that toxic doses of lidocaine induce significant disruption of glycolytic pathways, energy production, and redox balance, potentially leading to cell malfunction and death.
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Affiliation(s)
- Cory H T Boone
- Redox Biology Center, Department of Biochemistry, University of Nebraska - Lincoln, Lincoln, NE, USA
| | - Ryan A Grove
- Redox Biology Center, Department of Biochemistry, University of Nebraska - Lincoln, Lincoln, NE, USA
| | - Dana Adamcova
- Redox Biology Center, Department of Biochemistry, University of Nebraska - Lincoln, Lincoln, NE, USA
| | - Camila P Braga
- Redox Biology Center, Department of Biochemistry, University of Nebraska - Lincoln, Lincoln, NE, USA.,Department of Chemistry and Biochemistry, Institute of Bioscience, São Paulo State University, Botucatu, SP, Brazil
| | - Jiri Adamec
- Redox Biology Center, Department of Biochemistry, University of Nebraska - Lincoln, Lincoln, NE, USA
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139
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Hsieh J, Zhao X. Genetics and Epigenetics in Adult Neurogenesis. Cold Spring Harb Perspect Biol 2016; 8:cshperspect.a018911. [PMID: 27143699 DOI: 10.1101/cshperspect.a018911] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The cellular basis of adult neurogenesis is neural stem cells residing in restricted areas of the adult brain. These cells self-renew and are multipotent. The maintenance of "stemness" and commitment to differentiation are tightly controlled by intricate molecular networks. Epigenetic mechanisms, including chromatin remodeling, DNA methylation, and noncoding RNAs (ncRNAs), have profound regulatory roles in mammalian gene expression. Significant advances have been made regarding the dynamic roles of epigenetic modulation and function. It has become evident that epigenetic regulators are key players in neural-stem-cell self-renewal, fate specification, and final maturation of new neurons, therefore, adult neurogenesis. Altered epigenetic regulation can result in a number of neurological and neurodevelopmental disorders. Here, we review recent discoveries that advance our knowledge in epigenetic regulation of mammalian neural stem cells and neurogenesis. Insights from studies of epigenetic gene regulation in neurogenesis may lead to new therapies for the treatment of neurodevelopmental disorders.
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Affiliation(s)
- Jenny Hsieh
- Department of Molecular Biology and Hamon Center for Regenerative Science and Medicine, UT Southwestern Medical Center, Dallas, Texas 75390
| | - Xinyu Zhao
- Department of Neuroscience and Waisman Center, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53705
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140
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Rogawski MA, Löscher W, Rho JM. Mechanisms of Action of Antiseizure Drugs and the Ketogenic Diet. Cold Spring Harb Perspect Med 2016; 6:a022780. [PMID: 26801895 PMCID: PMC4852797 DOI: 10.1101/cshperspect.a022780] [Citation(s) in RCA: 173] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Antiseizure drugs (ASDs), also termed antiepileptic drugs, are the main form of symptomatic treatment for people with epilepsy, but not all patients become free of seizures. The ketogenic diet is one treatment option for drug-resistant patients. Both types of therapy exert their clinical effects through interactions with one or more of a diverse set of molecular targets in the brain. ASDs act by modulation of voltage-gated ion channels, including sodium, calcium, and potassium channels; by enhancement of γ-aminobutyric acid (GABA)-mediated inhibition through effects on GABAA receptors, the GABA transporter 1 (GAT1) GABA uptake transporter, or GABA transaminase; through interactions with elements of the synaptic release machinery, including synaptic vesicle 2A (SV2A) and α2δ; or by blockade of ionotropic glutamate receptors, including α-amino-3-hydroxy-5-methyl-4-isoxazole-propionate (AMPA) receptors. The ketogenic diet leads to increases in circulating ketones, which may contribute to the efficacy in treating pharmacoresistant seizures. Production in the brain of inhibitory mediators, such as adenosine, or ion channel modulators, such as polyunsaturated fatty acids, may also play a role. Metabolic effects, including diversion from glycolysis, are a further postulated mechanism. For some ASDs and the ketogenic diet, effects on multiple targets may contribute to activity. Better understanding of the ketogenic diet will inform the development of improved drug therapies to treat refractory seizures.
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Affiliation(s)
- Michael A Rogawski
- Department of Neurology, University of California, Davis, Sacramento, California 95817
| | - Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany
| | - Jong M Rho
- Department of Pediatrics, University of Calgary, Calgary, Alberta, Canada Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada Department of Physiology and Pharmacology, University of Calgary, Alberta, Canada
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141
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Terse PS, Joshi PS, Bordelon NR, Brys AM, Patton KM, Arndt TP, Sutula TP. 2-Deoxy-d-Glucose (2-DG)-Induced Cardiac Toxicity in Rat: NT-proBNP and BNP as Potential Early Cardiac Safety Biomarkers. Int J Toxicol 2016; 35:284-93. [PMID: 26838190 PMCID: PMC4864115 DOI: 10.1177/1091581815624397] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
2-Deoxy-d-glucose (2-DG) is being developed as a potential anticonvulsant and disease-modifying agent for patients with epilepsy; however, during preclinical development, cardiac toxicity has been encountered in rats. This study was performed to determine whether cardiac troponin (cTnI and cTnT), atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), N-terminal pro-brain natriuretic peptide (NT-proBNP), and/or creatine kinase (CK) could be useful as indicators of 2-DG cardiac toxicity. In addition, this study also investigated the association of cardiac histopathological changes with these biomarkers. F344 rats (4/sex/group/sacrifice point) were gavaged with either vehicle or 2-DG (50, 125, or 375 mg/kg twice daily; total daily dose of 100, 250, or 750 mg/kg/d) for 7, 14, 21, or 45 days followed by a 15-day recovery. Dose-dependent increases in NT-proBNP and BNP plasma concentrations were observed. Following recovery period, the NT-proBNP and BNP concentrations returned to baseline levels. There were no remarkable increases in CK, ANP, cTnI, or cTnT concentrations. There were no gross cardiac lesions observed at the necropsy. Microscopic findings of vacuolar degeneration and hypertrophy of the endothelial cells of the endocardium were present in the heart at doses of 250 and 750 mg/kg/d. Microscopic findings, in general, were associated with increases in NT-proBNP levels. Cardiac toxicity appeared to be reversible. In conclusion, NT-proBNP and BNP are potential early biomarkers for 2-DG-induced cardiac toxicity that can be useful to monitor 2-DG therapy in clinical trials.
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Affiliation(s)
- P S Terse
- National Center for Advancing Translational Sciences, Bethesda, MD, USA
| | - P S Joshi
- National Center for Advancing Translational Sciences, Bethesda, MD, USA
| | - N R Bordelon
- Battelle Memorial Institute, Columbus, OH, USA Covance, Greenfield, IN, USA
| | - A M Brys
- Battelle Memorial Institute, Columbus, OH, USA
| | - K M Patton
- Battelle Memorial Institute, Columbus, OH, USA
| | - T P Arndt
- Battelle Memorial Institute, Columbus, OH, USA Covance, Madison, WI, USA
| | - T P Sutula
- University of Wisconsin, Madison, WI, USA
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142
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Scichilone JM, Yarraguntla K, Charalambides A, Harney JP, Butler D. Environmental Enrichment Mitigates Detrimental Cognitive Effects of Ketogenic Diet in Weanling Rats. J Mol Neurosci 2016; 60:1-9. [DOI: 10.1007/s12031-016-0753-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 04/08/2016] [Indexed: 01/30/2023]
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143
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Ivanova D, Dirks A, Fejtova A. Bassoon and piccolo regulate ubiquitination and link presynaptic molecular dynamics with activity-regulated gene expression. J Physiol 2016; 594:5441-8. [PMID: 26915533 DOI: 10.1113/jp271826] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 01/29/2016] [Indexed: 12/26/2022] Open
Abstract
Release of neurotransmitter is executed by complex multiprotein machinery, which is assembled around the presynaptic cytomatrix at the active zone. One well-established function of this proteinaceous scaffold is the spatial organization of synaptic vesicle cluster, the protein complexes that execute membrane fusion and compensatory endocytosis, and the transmembrane molecules important for alignment of pre- and postsynaptic structures. The presynaptic cytomatrix proteins function also in processes other than the formation of a static frame for assembly of the release apparatus and synaptic vesicle cycling. They actively contribute to the regulation of multiple steps in this process and are themselves an important subject of regulation during neuronal plasticity. We are only beginning to understand the mechanisms and signalling pathways controlling these regulations. They are mainly dependent on posttranslational modifications, including phosphorylation and small-molecules conjugation, such as ubiquitination. Ubiquitination of presynaptic proteins might lead to their degradation by proteasomes, but evidence is growing that this modification also affects their function independently of their degradation. Signalling from presynapse to nucleus, which works on a much slower time scale and more globally, emerged as an important mechanism for persistent usage-dependent and homeostatic neuronal plasticity. Recently, two new functions for the largest presynaptic scaffolding proteins bassoon and piccolo emerged. They were implied (1) in the regulation of specific protein ubiquitination and proteasome-mediated proteolysis that potentially contributes to short-term plasticity at the presynapse and (2) in the coupling of activity-induced molecular rearrangements at the presynapse with reprogramming of expression of neuronal activity-regulated genes.
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Affiliation(s)
- Daniela Ivanova
- RG Presynaptic Plasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Anika Dirks
- Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Anna Fejtova
- RG Presynaptic Plasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany. .,Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany.
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144
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Boison D. The Biochemistry and Epigenetics of Epilepsy: Focus on Adenosine and Glycine. Front Mol Neurosci 2016; 9:26. [PMID: 27147960 PMCID: PMC4829603 DOI: 10.3389/fnmol.2016.00026] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 03/31/2016] [Indexed: 12/14/2022] Open
Abstract
Epilepsy, one of the most prevalent neurological conditions, presents as a complex disorder of network homeostasis characterized by spontaneous non-provoked seizures and associated comorbidities. Currently used antiepileptic drugs have been designed to suppress neuronal hyperexcitability and thereby to suppress epileptic seizures. However, the current armamentarium of antiepileptic drugs is not effective in over 30% of patients, does not affect the comorbidities of epilepsy, and does not prevent the development and progression of epilepsy (epileptogenesis). Prevention of epilepsy and its progression remains the Holy Grail for epilepsy research and therapy development, requiring novel conceptual advances to find a solution to this urgent medical need. The methylation hypothesis of epileptogenesis suggests that changes in DNA methylation are implicated in the progression of the disease. In particular, global DNA hypermethylation appears to be associated with chronic epilepsy. Clinical as well as experimental evidence demonstrates that epilepsy and its progression can be prevented by biochemical manipulations and those that target previously unrecognized epigenetic functions contributing to epilepsy development and maintenance of the epileptic state. This mini-review will discuss, epigenetic mechanisms implicated in epileptogenesis and biochemical interactions between adenosine and glycine as a conceptual advance to understand the contribution of maladaptive changes in biochemistry as a major contributing factor to the development of epilepsy. New findings based on biochemical manipulation of the DNA methylome suggest that: (i) epigenetic mechanisms play a functional role in epileptogenesis; and (ii) therapeutic reconstruction of the epigenome is an effective antiepileptogenic therapy.
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Affiliation(s)
- Detlev Boison
- Robert Stone Dow Neurobiology Laboratories, Legacy Research Institute Portland, OR, USA
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145
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Dallérac G, Rouach N. Astrocytes as new targets to improve cognitive functions. Prog Neurobiol 2016; 144:48-67. [PMID: 26969413 DOI: 10.1016/j.pneurobio.2016.01.003] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Revised: 01/07/2016] [Accepted: 01/24/2016] [Indexed: 01/09/2023]
Abstract
Astrocytes are now viewed as key elements of brain wiring as well as neuronal communication. Indeed, they not only bridge the gap between metabolic supplies by blood vessels and neurons, but also allow fine control of neurotransmission by providing appropriate signaling molecules and insulation through a tight enwrapping of synapses. Recognition that astroglia is essential to neuronal communication is nevertheless fairly recent and the large body of evidence dissecting such role has focused on the synaptic level by identifying neuro- and gliotransmitters uptaken and released at synaptic or extrasynaptic sites. Yet, more integrated research deciphering the impact of astroglial functions on neuronal network activity have led to the reasonable assumption that the role of astrocytes in supervising synaptic activity translates in influencing neuronal processing and cognitive functions. Several investigations using recent genetic tools now support this notion by showing that inactivating or boosting astroglial function directly affects cognitive abilities. Accordingly, brain diseases resulting in impaired cognitive functions have seen their physiopathological mechanisms revisited in light of this primary protagonist of brain processing. We here provide a review of the current knowledge on the role of astrocytes in cognition and in several brain diseases including neurodegenerative disorders, psychiatric illnesses, as well as other conditions such as epilepsy. Potential astroglial therapeutic targets are also discussed.
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Affiliation(s)
- Glenn Dallérac
- Neuroglial Interactions in Cerebral Physiopathology, Center for Interdisciplinary Research in Biology, Collège de France, Centre National de la Recherche Scientifique UMR 7241, Institut National de la Santé et de la Recherche Médicale U1050, Labex Memolife, PSL Research University, Paris, France.
| | - Nathalie Rouach
- Neuroglial Interactions in Cerebral Physiopathology, Center for Interdisciplinary Research in Biology, Collège de France, Centre National de la Recherche Scientifique UMR 7241, Institut National de la Santé et de la Recherche Médicale U1050, Labex Memolife, PSL Research University, Paris, France.
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146
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Warburton A, Miyajima F, Shazadi K, Crossley J, Johnson MR, Marson AG, Baker GA, Quinn JP, Sills GJ. NRSF and BDNF polymorphisms as biomarkers of cognitive dysfunction in adults with newly diagnosed epilepsy. Epilepsy Behav 2016; 54:117-27. [PMID: 26708060 PMCID: PMC4732989 DOI: 10.1016/j.yebeh.2015.11.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Revised: 11/09/2015] [Accepted: 11/14/2015] [Indexed: 12/31/2022]
Abstract
Cognitive dysfunction is a common comorbidity in people with epilepsy, but its causes remain unclear. It may be related to the etiology of the disorder, the consequences of seizures, or the effects of antiepileptic drug treatment. Genetics may also play a contributory role. We investigated the influence of variants in the genes encoding neuron-restrictive silencer factor (NRSF) and brain-derived neurotrophic factor (BDNF), proteins previously associated with cognition and epilepsy, on cognitive function in people with newly diagnosed epilepsy. A total of 82 patients who had previously undergone detailed neuropsychological assessment were genotyped for single nucleotide polymorphisms (SNPs) across the NRSF and BDNF genes. Putatively functional SNPs were included in a genetic association analysis with specific cognitive domains, including memory, psychomotor speed, and information processing. Cross-sectional and longitudinal designs were used to explore genetic influences on baseline cognition at diagnosis and change from baseline over the first year since diagnosis, respectively. We found a statistically significant association between genotypic variation and memory function at both baseline (NRSF: rs1105434, rs2227902 and BDNF: rs1491850, rs2030324, rs11030094) and in our longitudinal analysis (NRSF: rs2227902 and BDNF: rs12273363). Psychomotor speed was also associated with genotype (NRSF rs3796529) in the longitudinal assessment. In line with our previous work on general cognitive function in the healthy aging population, we observed an additive interaction between risk alleles for the NRSF rs2227902 (G) and BDNF rs6265 (A) polymorphisms which was again consistent with a significantly greater decline in delayed recall over the first year since diagnosis. These findings support a role for the NRSF-BDNF pathway in the modulation of cognitive function in patients with newly diagnosed epilepsy.
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Affiliation(s)
- Alix Warburton
- Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool L69 3GL, UK
| | - Fabio Miyajima
- Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool L69 3GL, UK
| | - Kanvel Shazadi
- Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool L69 3GL, UK
| | - Joanne Crossley
- Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool L69 3GL, UK
| | | | - Anthony G Marson
- Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool L69 3GL, UK
| | - Gus A Baker
- Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool L69 3GL, UK
| | - John P Quinn
- Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool L69 3GL, UK
| | - Graeme J Sills
- Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool L69 3GL, UK.
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147
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Thakore-Shah K, Koleilat T, Jan M, John A, Pyle AD. REST/NRSF Knockdown Alters Survival, Lineage Differentiation and Signaling in Human Embryonic Stem Cells. PLoS One 2015; 10:e0145280. [PMID: 26690059 PMCID: PMC4699193 DOI: 10.1371/journal.pone.0145280] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 12/02/2015] [Indexed: 12/19/2022] Open
Abstract
REST (RE1 silencing transcription factor), also known as NRSF (neuron-restrictive silencer factor), is a well-known transcriptional repressor of neural genes in non-neural tissues and stem cells. Dysregulation of REST activity is thought to play a role in diverse diseases including epilepsy, cancer, Down’s syndrome and Huntington’s disease. The role of REST/NRSF in control of human embryonic stem cell (hESC) fate has never been examined. To evaluate the role of REST in hESCs we developed an inducible REST knockdown system and examined both growth and differentiation over short and long term culture. Interestingly, we have found that altering REST levels in multiple hESC lines does not result in loss of self-renewal but instead leads to increased survival. During differentiation, REST knockdown resulted in increased MAPK/ERK and WNT signaling and increased expression of mesendoderm differentiation markers. Therefore we have uncovered a new role for REST in regulation of growth and early differentiation decisions in human embryonic stem cells.
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Affiliation(s)
- Kaushali Thakore-Shah
- Molecular Biology Institute, University of California Los Angeles, Los Angeles, CA, 90095, United States of America
| | - Tasneem Koleilat
- California State University, Northridge, CA, 91325, United States of America
| | - Majib Jan
- California State University, Northridge, CA, 91325, United States of America
| | - Alan John
- Department of Microbiology, Immunology, and Molecular Genetics, University of California Los Angeles, Los Angeles, CA, 90095, United States of America
| | - April D. Pyle
- Molecular Biology Institute, University of California Los Angeles, Los Angeles, CA, 90095, United States of America
- Department of Microbiology, Immunology, and Molecular Genetics, University of California Los Angeles, Los Angeles, CA, 90095, United States of America
- Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, Jonsson Comprehensive Cancer Center, University of California Los Angeles, Los Angeles, CA, 90095, United States of America
- * E-mail:
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148
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Schiffer D, Caldera V, Mellai M, Conforti P, Cattaneo E, Zuccato C. Repressor element-1 silencing transcription factor (REST) is present in human control and Huntington's disease neurones. Neuropathol Appl Neurobiol 2015; 40:899-910. [PMID: 24634989 DOI: 10.1111/nan.12137] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 03/12/2014] [Indexed: 01/25/2023]
Abstract
AIMS The repressor element-1 silencing transcription factor/neurone-restrictive silencer factor (REST/NRSF) is a master regulator of neuronal gene expression. REST/NRSF functions by recruiting other cofactors to genomic loci that contain the repressor element 1/neurone restrictive silencer element (RE1/NRSE) binding motif. In brain, demonstration of REST protein presence in neurones has remained controversial. However, RE1/NRSE containing neuronal genes are actively modulated and REST dysregulation is implicated in Huntington's disease (HD). We aimed to investigate REST distribution in autopsy brain from control and HD patients. METHODS Brain tissues from six controls and six HD cases (Vonsattel grade 3 and 4) were investigated using immunohistochemical analysis. RESULTS REST was present in neurones and glial cells of the cortex, caudate nucleus, hippocampus and cerebellum. REST labelling was mainly cytoplasmic in neurones while preferential nuclear staining of REST was found in glial cells. We also found that REST and huntingtin (HTT) colocalize in human neurones. Low levels of cytoplasmic REST were detected in neurones of the HD cortex and caudate but no direct relationship between decreased neuronal REST expression and disease grade was observed. CONCLUSIONS These data support the notion of REST presence in human brain neurones and glial cells and indicate the importance of developing compounds able to restore REST-regulated transcription of neuronal genes in HD.
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Affiliation(s)
- Davide Schiffer
- Neuro-Bio-Oncology Research Center, Policlinico di Monza Foundation, Vercelli; Consorzio per le Neuroscienze, University of Pavia, Pavia
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149
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Meyer K, Albaugh B, Schoenike B, Roopra A. Type 1 Insulin-Like Growth Factor Receptor/Insulin Receptor Substrate 1 Signaling Confers Pathogenic Activity on Breast Tumor Cells Lacking REST. Mol Cell Biol 2015; 35:2991-3004. [PMID: 26100015 PMCID: PMC4525306 DOI: 10.1128/mcb.01149-14] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 10/16/2014] [Accepted: 06/14/2015] [Indexed: 11/20/2022] Open
Abstract
Loss of repressor element 1 silencing transcription factor (REST) occurs in 20% of breast cancers and correlates with a poor patient prognosis. However, the molecular basis for enhanced malignancy in tumors lacking REST (RESTless) is only partially understood. We used multiplatform array data from the Cancer Genome Atlas to identify consistent changes in key signaling pathways. Of the proteins screened in the reverse-phase protein array, we found that insulin receptor substrate 1 (IRS1) is the most highly upregulated protein in RESTless breast tumors. Analysis of breast tumor cell lines showed that REST directly represses IRS1, and cells lacking REST have increased levels of IRS1 mRNA and protein. We find that the upregulation of IRS1 function is both necessary and sufficient for enhanced signaling and growth in breast cancer cells lacking REST. IRS1 overexpression is sufficient to phenocopy the enhanced activation of the signaling hubs AKT and mitogen-activated protein kinase (MAPK) of MCF7 cells lacking REST. Loss of REST renders MCF7 and MDA-MB-231 breast tumor cells dependent on IRS1 activity for colony formation in soft agar. Inhibition of the type 1 insulin-like growth factor receptor (IGF1R) reduces the enhanced signaling, growth, and migration in breast tumor cells that occur upon REST loss. We show that loss of REST induces a pathogenic program that works through the IGF1R/IRS1 pathway.
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Affiliation(s)
- Kassondra Meyer
- Molecular and Cellular Pharmacology Graduate Program, University of Wisconsin-Madison, Madison, Wisconsin, USA Department of Neuroscience, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Brittany Albaugh
- Department of Neuroscience, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Barry Schoenike
- Department of Neuroscience, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Avtar Roopra
- Department of Neuroscience, University of Wisconsin-Madison, Madison, Wisconsin, USA
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150
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Lusardi TA, Akula KK, Coffman SQ, Ruskin DN, Masino SA, Boison D. Ketogenic diet prevents epileptogenesis and disease progression in adult mice and rats. Neuropharmacology 2015; 99:500-9. [PMID: 26256422 DOI: 10.1016/j.neuropharm.2015.08.007] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 07/08/2015] [Accepted: 08/03/2015] [Indexed: 12/16/2022]
Abstract
Epilepsy is a highly prevalent seizure disorder which tends to progress in severity and become refractory to treatment. Yet no therapy is proven to halt disease progression or to prevent the development of epilepsy. Because a high fat low carbohydrate ketogenic diet (KD) augments adenosine signaling in the brain and because adenosine not only suppresses seizures but also affects epileptogenesis, we hypothesized that a ketogenic diet might prevent epileptogenesis through similar mechanisms. Here, we tested this hypothesis in two independent rodent models of epileptogenesis. Using a pentylenetetrazole kindling paradigm in mice, we first show that a KD, but not a conventional antiepileptic drug (valproic acid), suppressed kindling-epileptogenesis. Importantly, after treatment reversal, increased seizure thresholds were maintained in those animals kindled in the presence of a KD, but not in those kindled in the presence of valproic acid. Next, we tested whether a KD can halt disease progression in a clinically relevant model of progressive epilepsy. Epileptic rats that developed spontaneous recurrent seizures after a pilocarpine-induced status epilepticus were treated with a KD or control diet (CD). Whereas seizures progressed in severity and frequency in the CD-fed animals, KD-fed animals showed a prolonged reduction of seizures, which persisted after diet reversal. KD-treatment was associated with increased adenosine and decreased DNA methylation, the latter being maintained after diet discontinuation. Our findings demonstrate that a KD prevented disease progression in two mechanistically different models of epilepsy, and suggest an epigenetic mechanism underlying the therapeutic effects.
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Affiliation(s)
- Theresa A Lusardi
- RS Dow Neurobiology Laboratories, Legacy Research Institute, Portland, OR 97232, USA
| | - Kiran K Akula
- RS Dow Neurobiology Laboratories, Legacy Research Institute, Portland, OR 97232, USA
| | - Shayla Q Coffman
- RS Dow Neurobiology Laboratories, Legacy Research Institute, Portland, OR 97232, USA
| | - David N Ruskin
- Department of Psychology and Neuroscience Program, Trinity College, Hartford, CT 06106, USA
| | - Susan A Masino
- Department of Psychology and Neuroscience Program, Trinity College, Hartford, CT 06106, USA
| | - Detlev Boison
- RS Dow Neurobiology Laboratories, Legacy Research Institute, Portland, OR 97232, USA.
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