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Skwarzynska D, Sun H, Kasprzak I, Sharma S, Williamson J, Kapur J. Glycolytic lactate production supports status epilepticus in experimental animals. Ann Clin Transl Neurol 2023; 10:1873-1884. [PMID: 37632130 PMCID: PMC10578888 DOI: 10.1002/acn3.51881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 07/27/2023] [Accepted: 08/09/2023] [Indexed: 08/27/2023] Open
Abstract
OBJECTIVE Status epilepticus (SE) requires rapid intervention to prevent cerebral injury and mortality. The ketogenic diet, which bypasses glycolysis, is a promising remedy for patients with refractory SE. We tested the role of glycolytic lactate production in sustaining SE. METHODS Extracellular lactate and glucose concentration during a seizure and SE in vivo was measured using lactate and glucose biosensors. A lactate dehydrogenase inhibitor, oxamate, blocked pyruvate to lactate conversion during SE. Video-EEG recordings evaluated seizure duration, severity, and immunohistochemistry was used to determine neuronal loss. Genetically encoded calcium indicator GCaMP7 was used to study the effect of oxamate on CA1 pyramidal neurons in vitro. Spontaneous excitatory postsynaptic currents (sEPSCs) were recorded from CA1 neurons to study oxamate's impact on neurotransmission. RESULTS The extracellular glucose concentration dropped rapidly during seizures, and lactate accumulated in the extracellular space. Inhibition of pyruvate to lactate conversion with oxamate terminated SE in mice. There was less neuronal loss in treated compared to control mice. Oxamate perfusion decreased tonic and phasic neuronal activity of GCaMP7-expressing CA1 pyramidal neurons in vitro. Oxamate application reduced the frequency, but not amplitude of sEPSCs recorded from CA1 neurons, suggesting an effect on the presynaptic glutamatergic neurotransmission. INTERPRETATION A single seizure and SE stimulate lactate production. Diminishing pyruvate to lactate conversion with oxamate terminated SE and reduced associated neuronal death. Oxamate reduced neuronal excitability and excitatory neurotransmission at the presynaptic terminal. Glycolytic lactate production sustains SE and is an attractive therapeutic target.
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Affiliation(s)
- Daria Skwarzynska
- Neuroscience Graduate ProgramUniversity of VirginiaCharlottesvilleVirginia22908USA
| | - Huayu Sun
- Department of NeurologyUniversity of VirginiaCharlottesvilleVirginia22908USA
| | - Izabela Kasprzak
- Department of NeurologyUniversity of VirginiaCharlottesvilleVirginia22908USA
| | - Supriya Sharma
- Department of NeurologyUniversity of VirginiaCharlottesvilleVirginia22908USA
| | - John Williamson
- Department of NeurologyUniversity of VirginiaCharlottesvilleVirginia22908USA
| | - Jaideep Kapur
- Department of NeurologyUniversity of VirginiaCharlottesvilleVirginia22908USA
- UVA Brain InstituteUniversity of VirginiaCharlottesvilleVirginia22908USA
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2
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Grizzanti J, Moritz WR, Pait MC, Stanley M, Kaye SD, Carroll CM, Constantino NJ, Deitelzweig LJ, Snipes JA, Kellar D, Caesar EE, Pettit-Mee RJ, Day SM, Sens JP, Nicol NI, Dhillon J, Remedi MS, Kiraly DD, Karch CM, Nichols CG, Holtzman DM, Macauley SL. KATP channels are necessary for glucose-dependent increases in amyloid-β and Alzheimer's disease-related pathology. JCI Insight 2023; 8:e162454. [PMID: 37129980 PMCID: PMC10386887 DOI: 10.1172/jci.insight.162454] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 04/18/2023] [Indexed: 05/03/2023] Open
Abstract
Elevated blood glucose levels, or hyperglycemia, can increase brain excitability and amyloid-β (Aβ) release, offering a mechanistic link between type 2 diabetes and Alzheimer's disease (AD). Since the cellular mechanisms governing this relationship are poorly understood, we explored whether ATP-sensitive potassium (KATP) channels, which couple changes in energy availability with cellular excitability, play a role in AD pathogenesis. First, we demonstrate that KATP channel subunits Kir6.2/KCNJ11 and SUR1/ABCC8 were expressed on excitatory and inhibitory neurons in the human brain, and cortical expression of KCNJ11 and ABCC8 changed with AD pathology in humans and mice. Next, we explored whether eliminating neuronal KATP channel activity uncoupled the relationship between metabolism, excitability, and Aβ pathology in a potentially novel mouse model of cerebral amyloidosis and neuronal KATP channel ablation (i.e., amyloid precursor protein [APP]/PS1 Kir6.2-/- mouse). Using both acute and chronic paradigms, we demonstrate that Kir6.2-KATP channels are metabolic sensors that regulate hyperglycemia-dependent increases in interstitial fluid levels of Aβ, amyloidogenic processing of APP, and amyloid plaque formation, which may be dependent on lactate release. These studies identify a potentially new role for Kir6.2-KATP channels in AD and suggest that pharmacological manipulation of Kir6.2-KATP channels holds therapeutic promise in reducing Aβ pathology in patients with diabetes or prediabetes.
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Affiliation(s)
- John Grizzanti
- Department of Physiology and Pharmacology and
- Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - William R. Moritz
- Department of Neurology, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
| | - Morgan C. Pait
- Department of Physiology and Pharmacology and
- Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Molly Stanley
- Department of Neurology, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
- Department of Biology, College of Arts and Sciences, University of Vermont, Burlington, Vermont, USA
| | - Sarah D. Kaye
- Department of Physiology and Pharmacology and
- Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Caitlin M. Carroll
- Department of Physiology and Pharmacology and
- Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Nicholas J. Constantino
- Department of Physiology and Pharmacology and
- Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Lily J. Deitelzweig
- Department of Physiology and Pharmacology and
- Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - James A. Snipes
- Department of Physiology and Pharmacology and
- Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Derek Kellar
- Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Emily E. Caesar
- Department of Neurology, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
| | | | | | | | - Noelle I. Nicol
- Department of Physiology and Pharmacology and
- Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Jasmeen Dhillon
- Department of Physiology and Pharmacology and
- Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Maria S. Remedi
- Department of Physiology and Pharmacology and
- Department of Medicine, Division of Endocrinology, Metabolism and Lipid Research
| | | | - Celeste M. Karch
- Department of Psychiatry
- Hope Center for Neurological Disorders
- Knight Alzheimer’s Disease Research Center, Department of Neurology; and
| | - Colin G. Nichols
- Center for the Investigation of Membrane Excitability Diseases, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
| | - David M. Holtzman
- Department of Neurology, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
- Hope Center for Neurological Disorders
- Knight Alzheimer’s Disease Research Center, Department of Neurology; and
| | - Shannon L. Macauley
- Department of Physiology and Pharmacology and
- Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
- Alzheimer’s Disease Research Center
- Center on Diabetes, Obesity and Metabolism
- Center for Precision Medicine; and
- Cardiovascular Sciences Center, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
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3
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Brukner AM, Billington S, Benifla M, Nguyen TB, Han H, Bennett O, Gilboa T, Blatch D, Fellig Y, Volkov O, Unadkat JD, Ekstein D, Eyal S. Abundance of P-glycoprotein and Breast Cancer Resistance Protein Measured by Targeted Proteomics in Human Epileptogenic Brain Tissue. Mol Pharm 2021; 18:2263-2273. [PMID: 34008992 PMCID: PMC8488956 DOI: 10.1021/acs.molpharmaceut.1c00083] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
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Our goal was to measure the absolute
differential abundance of
key drug transporters in human epileptogenic brain tissue and to compare
them between patients and at various distances from the epileptogenic
zone within the same patient. Transporter protein abundance was quantified
in brain tissue homogenates from patients who underwent epilepsy surgery,
using targeted proteomics, and correlations with clinical and tissue
characteristics were assessed. Fourteen brain samples (including four
epileptogenic hippocampal samples) were collected from nine patients.
Among the quantifiable drug transporters, the abundance (median, range)
ranked: breast cancer resistance protein (ABCG2/BCRP; 0.55, 0.01–3.26
pmol/g tissue) > P-glycoprotein (ABCB1/MDR1; 0.30,
0.02–1.15 pmol/g tissue) > equilibrative nucleoside transporter
1 (SLC29A1/ENT1; 0.06, 0.001–0.35 pmol/g tissue). The ABCB1/ABCG2
ratio (mean 0.27, range 0.08–0.47) was comparable with literature
values from nonepileptogenic brain tissue (mean 0.5–0.8). Transporter
abundance was lower in the hippocampi than in the less epileptogenic
neocortex of the same patients. ABCG2/BCRP and ABCB1/MDR1 expression
strongly correlated with that of glucose transporter 1 (SLC2A1/GLUT1)
(r = 0.97, p < 0.001; r = 0.90, p < 0.01, respectively). Low
transporter abundance was found in patients with overt vascular pathology,
whereas the highest abundance was seen in a sample with normally appearing
blood vessels. In conclusion, drug transporter abundance highly varies
across patients and between epileptogenic and less epileptogenic brain
tissue of the same patient. The strong correlation in abundance of
ABCB1/MDR1, ABCG2/BCRP, and SLC2A1/GLUT1 suggests variation in the
content of the functional vasculature within the tissue samples. The
epileptogenic tissue can be depleted of key drug transport mechanisms,
warranting consideration when selecting treatments for patients with
drug-resistant epilepsy.
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Affiliation(s)
- Aniv Mann Brukner
- Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Room 613, Ein Kerem, Jerusalem 91120, Israel
| | - Sarah Billington
- Department of Pharmaceutics, School of Pharmacy, University of Washington, Seattle, Washington 98195, United States
| | - Mony Benifla
- Children's Neurosurgery Department, Rambam Academic Hospital, Haifa 31999, Israel
| | - Tot Bui Nguyen
- Department of Pharmaceutics, School of Pharmacy, University of Washington, Seattle, Washington 98195, United States
| | - Hadas Han
- Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Room 613, Ein Kerem, Jerusalem 91120, Israel
| | - Odeya Bennett
- Department of Pediatrics, Shaare Zedek Medical Center, Jerusalem 91031, Israel
| | - Tal Gilboa
- Neuropediatric Unit, Pediatrics Division, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel.,The Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | - Dana Blatch
- Department of Neurology, Agnes Ginges Center for Human Neurogenetics, Hadassah Medical Organization, Jerusalem 91120, Israel
| | - Yakov Fellig
- The Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel.,Department of Pathology, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Olga Volkov
- Nuclear Medicine Institute, Sheba Medical Center, Tel Hashomer 52621, Israel
| | - Jashvant D Unadkat
- Department of Pharmaceutics, School of Pharmacy, University of Washington, Seattle, Washington 98195, United States
| | - Dana Ekstein
- The Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel.,Department of Neurology, Agnes Ginges Center for Human Neurogenetics, Hadassah Medical Organization, Jerusalem 91120, Israel
| | - Sara Eyal
- Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Room 613, Ein Kerem, Jerusalem 91120, Israel
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4
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Bouras T, Gatzonis SS, Georgakoulias N, Karatza M, Siatouni A, Stranjalis G, Boviatsis E, Vasileiou S, Sakas DE. Neuro-inflammatory Sequelae of Minimal Trauma in the Non-traumatized Human Brain: A Microdialysis Study. J Neurotrauma 2021; 38:1137-1150. [PMID: 22098490 DOI: 10.1089/neu.2011.1790] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022] Open
Abstract
Cytokine measurement directly from the brain parenchyma by means of microdialysis has documented the activation of certain procedures in vivo, after brain trauma in humans. However, the intercalation of the micro-catheter insertion with the phenomena triggered by the head trauma renders the assessment of the findings problematic. The present study attempts to elucidate the pure effect of minimal trauma, represented by the insertion of the micro-catheter, on the non-traumatized human brain. Microdialysis catheters were implanted in 12 patients with drug-resistant epilepsy, and subjected to invasive electroencephalography with intracranial electrodes. Samples were collected during the first 5 days of monitoring. The dialysate was analyzed using bead flow cytometry, and the concentrations of interleukin (IL)-1, IL-6, IL-8, IL-10, IL-12, and tumor necrosis factor-α (TNF-α) were measured. The levels of IL-1 and IL-8 were found to be raised until 48 h post-implantation, and thereafter they reached a plateau of presumably baseline values. The temporal profile of the IL-6 variation was different, with the increase being much more prolonged, as its concentration had not returned to baseline levels at the fifth day post-insertion. TNF-α was found to be significantly raised only 2 h after implantation. IL-10 and IL-12 did not have any significant response to micro-trauma. These findings imply that the reaction of the neuro-inflammatory mechanisms of the brain exist even after minimal trauma, and is unexpectedly intense for IL-6. Questions may arise regarding the objectivity of findings attributed by some studies to inflammatory perturbation after head injury.
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Affiliation(s)
- Triantafyllos Bouras
- Department of Neurosurgery, Evaggelismos Hospital, University of Athens, Athens, Greece
| | | | | | - Marilena Karatza
- Laboratory of Biochemistry, Evaggelismos Hospital, University of Athens, Athens, Greece
| | - Anna Siatouni
- Department of Neurosurgery, Evaggelismos Hospital, University of Athens, Athens, Greece
| | - George Stranjalis
- Department of Neurosurgery, Evaggelismos Hospital, University of Athens, Athens, Greece
| | - Efstathios Boviatsis
- Department of Neurosurgery, Evaggelismos Hospital, University of Athens, Athens, Greece
| | - Spyridoula Vasileiou
- Laboratory of Biochemistry, Evaggelismos Hospital, University of Athens, Athens, Greece
| | - Damianos E Sakas
- Department of Neurosurgery, Evaggelismos Hospital, University of Athens, Athens, Greece
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5
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Ibhazehiebo K, Rho JM, Kurrasch DM. Metabolism-based drug discovery in zebrafish: An emerging strategy to uncover new anti-seizure therapies. Neuropharmacology 2020; 167:107988. [PMID: 32070912 DOI: 10.1016/j.neuropharm.2020.107988] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 02/01/2020] [Accepted: 02/03/2020] [Indexed: 12/20/2022]
Abstract
As one of the most common neurological disorders, epilepsy can occur throughout the lifespan and from a multiplicity of causes, including genetic mutations, inflammation, neurotrauma, or brain malformations. Although pharmacological agents are the mainstay of treatment for seizure control, an unyielding 30-40% of patients remain refractory to these medications and continue to experience spontaneous recurrent seizures with attendant life-long cognitive, behavioural, and mental health issues, as well as an increased risk for sudden unexpected death. Despite over eight decades of antiseizure drug (ASD) discovery and the approval of dozens of new medications, the percentage of this refractory population remains virtually unchanged, suggesting that drugs with new and unexpected mechanisms of action are needed. In this brief review, we discuss the need for new animal models of epilepsy, with a particular focus on the advantages and disadvantages of zebrafish. We also outline the evidence that epilepsy is characterized by derangements in mitochondrial function and introduce the rationale and promise of bioenergetics as a functional readout assay to uncover novel ASDs. We also consider limitations of a zebrafish metabolism-based drug screening approach. Our goal is to discuss the opportunities and challenges of further development of mitochondrial screening strategies for the development of novel ASDs. This article is part of the special issue entitled 'New Epilepsy Therapies for the 21st Century - From Antiseizure Drugs to Prevention, Modification and Cure of Epilepsy'.
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Affiliation(s)
- Kingsley Ibhazehiebo
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Canada; Alberta Children's Hospital Research Institute, University of Calgary, Canada
| | - Jong M Rho
- Alberta Children's Hospital Research Institute, University of Calgary, Canada; Department of Pediatrics, Cumming School of Medicine, University of Calgary, Canada; Department of Neurosciences and Pediatrics, University of California San Diego, Rady Children's Hospital San Diego, California, USA
| | - Deborah M Kurrasch
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Canada; Alberta Children's Hospital Research Institute, University of Calgary, Canada.
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6
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Oses JP, Müller AP, Strogulski NR, Moreira JD, Böhmer AE, Hansel G, Carteri RB, Busnello JV, Kopczynski A, Rodolphi MS, Souza DO, Portela LV. Sustained elevation of cerebrospinal fluid glucose and lactate after a single seizure does not parallel with mitochondria energy production. Epilepsy Res 2019; 152:35-41. [PMID: 30875635 DOI: 10.1016/j.eplepsyres.2019.03.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 02/18/2019] [Accepted: 03/09/2019] [Indexed: 12/22/2022]
Abstract
Generalized seizures trigger excessive neuronal firing that imposes large demands on the brain glucose/lactate availability and utilization, which synchronization requires an integral mitochondrial oxidative capability. We investigated whether a single convulsive crisis affects brain glucose/lactate availability and mitochondrial energy production. Adult male Wistar rats received a single injection of pentylentetrazol (PTZ, 60 mg/kg, i.p.) or saline. The cerebrospinal fluid (CSF) levels of glucose and lactate, mitochondrial respirometry, [14C]-2-deoxy-D-glucose uptake, glycogen content and cell viability in hippocampus were measured. CSF levels of glucose and lactate (mean ± SD) in control animals were 68.08 ± 11.62 mg/dL and 1.17 ± 0.32 mmol/L, respectively. Tonic-clonic seizures increased glucose levels at 10 min (96.25 ± 13.19) peaking at 60 min (113.03 ± 16.34) returning to control levels at 24 h (50.12 ± 12.81), while lactate increased at 10 min (3.23 ± 1.57) but returned to control levels at 360 min after seizures (1.58 ± 0.21). The hippocampal [14C]-2-deoxy-D-glucose uptake, glycogen content, and cell viability decreased up to 60 min after the seizures onset. Also, an uncoupling between mitochondrial oxygen consumption and ATP synthesis via FoF1-ATP synthase was observed at 10 min, 60 min and 24 h after seizures. In summary, after a convulsive seizure glucose and lactate levels immediately rise within the brain, however, considering the acute impact of this metabolic crisis, mitochondria are not able to increase energy production thereby affecting cell viability.
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Affiliation(s)
- Jean Pierre Oses
- Programa de Pós-graduação em Ciências Biológicas, Bioquímica, Laboratório de Neurotrauma e Biomarcadores, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Alexandre Pastoris Müller
- Unidade de Ciências da Saúde, Laboratório de Bioquímica e Fisiologia do Exercício Universidade do Extremo Sul Catarinense-UNESC, Av. Universitária, 1105 - Bairro Universitário, CEP 88806-000, Criciúma, Santa Catarina, Brazil
| | - Nathan Ryzewski Strogulski
- Programa de Pós-graduação em Ciências Biológicas, Bioquímica, Laboratório de Neurotrauma e Biomarcadores, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Julia D Moreira
- Programa de Pós-graduação em Ciências Biológicas, Bioquímica, Laboratório de Neurotrauma e Biomarcadores, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Departamento de Nutrição, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - Ana Elisa Böhmer
- Programa de Pós-graduação em Ciências Biológicas, Bioquímica, Laboratório de Neurotrauma e Biomarcadores, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Gisele Hansel
- Programa de Pós-graduação em Ciências Biológicas, Bioquímica, Laboratório de Neurotrauma e Biomarcadores, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Randhall Bruce Carteri
- Programa de Pós-graduação em Ciências Biológicas, Bioquímica, Laboratório de Neurotrauma e Biomarcadores, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - João Vicente Busnello
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, Chicago, IL, USA
| | - Afonso Kopczynski
- Programa de Pós-graduação em Ciências Biológicas, Bioquímica, Laboratório de Neurotrauma e Biomarcadores, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Marcelo Salimen Rodolphi
- Programa de Pós-graduação em Ciências Biológicas, Bioquímica, Laboratório de Neurotrauma e Biomarcadores, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Diogo Onofre Souza
- Programa de Pós-graduação em Ciências Biológicas, Bioquímica, Laboratório de Neurotrauma e Biomarcadores, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Luis Valmor Portela
- Programa de Pós-graduação em Ciências Biológicas, Bioquímica, Laboratório de Neurotrauma e Biomarcadores, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
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7
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McDonald T, Puchowicz M, Borges K. Impairments in Oxidative Glucose Metabolism in Epilepsy and Metabolic Treatments Thereof. Front Cell Neurosci 2018; 12:274. [PMID: 30233320 PMCID: PMC6127311 DOI: 10.3389/fncel.2018.00274] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 08/06/2018] [Indexed: 12/19/2022] Open
Abstract
There is mounting evidence that oxidative glucose metabolism is impaired in epilepsy and recent work has further characterized the metabolic mechanisms involved. In healthy people eating a traditional diet, including carbohydrates, fats and protein, the major energy substrate in brain is glucose. Cytosolic glucose metabolism generates small amounts of energy, but oxidative glucose metabolism in the mitochondria generates most ATP, in addition to biosynthetic precursors in cells. Energy is crucial for the brain to signal "normally," while loss of energy can contribute to seizure generation by destabilizing membrane potentials and signaling in the chronic epileptic brain. Here we summarize the known biochemical mechanisms that contribute to the disturbance in oxidative glucose metabolism in epilepsy, including decreases in glucose transport, reduced activity of particular steps in the oxidative metabolism of glucose such as pyruvate dehydrogenase activity, and increased anaplerotic need. This knowledge justifies the use of alternative brain fuels as sources of energy, such as ketones, TCA cycle intermediates and precursors as well as even medium chain fatty acids and triheptanoin.
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Affiliation(s)
- Tanya McDonald
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia
| | - Michelle Puchowicz
- Department of Nutrition, School of Medicine, Case Western Reserve University, Cleveland, OH, United States
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Karin Borges
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia
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8
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Lourenço CF, Ledo A, Gerhardt GA, Laranjinha J, Barbosa RM. Neurometabolic and electrophysiological changes during cortical spreading depolarization: multimodal approach based on a lactate-glucose dual microbiosensor arrays. Sci Rep 2017; 7:6764. [PMID: 28754993 PMCID: PMC5533760 DOI: 10.1038/s41598-017-07119-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 06/21/2017] [Indexed: 12/24/2022] Open
Abstract
Spreading depolarization (SD) is a slow propagating wave of strong depolarization of neural cells, implicated in several neuropathological conditions. The breakdown of brain homeostasis promotes significant hemodynamic and metabolic alterations, which impacts on neuronal function. In this work we aimed to develop an innovative multimodal approach, encompassing metabolic, electric and hemodynamic measurements, tailored but not limited to study SD. This was based on a novel dual-biosensor based on microelectrode arrays designed to simultaneously monitor lactate and glucose fluctuations and ongoing neuronal activity with high spatial and temporal resolution. In vitro evaluation of dual lactate-glucose microbiosensor revealed an extended linear range, high sensitivity and selectivity, fast response time and low oxygen-, temperature- and pH- dependencies. In anesthetized rats, we measured with the same array a significant drop in glucose concentration matched to a rise in lactate and concurrently with pronounced changes in the spectral profile of LFP-related currents during episodes of mechanically-evoked SD. This occurred along with the stereotypical hemodynamic response of the SD wave. Overall, this multimodal approach successfully demonstrates the capability to monitor metabolic alterations and ongoing electrical activity, thus contributing to a better understanding of the metabolic changes occurring in the brain following SD.
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Affiliation(s)
- Cátia F Lourenço
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.
| | - Ana Ledo
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Greg A Gerhardt
- Center for Microelectrode Technology, University of Kentucky, Lexington, USA
| | - João Laranjinha
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
| | - Rui M Barbosa
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal. .,Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal.
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9
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McDonald TS, Borges K. Impaired hippocampal glucose metabolism during and after flurothyl-induced seizures in mice: Reduced phosphorylation coincides with reduced activity of pyruvate dehydrogenase. Epilepsia 2017. [PMID: 28632902 DOI: 10.1111/epi.13796] [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] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To determine changes in glucose metabolism and the enzymes involved in the hippocampus ictally and postictally in the acute mouse flurothyl seizure model. METHODS [U-13 C]-Glucose was injected (i.p.) prior to, or following a 5 min flurothyl-induced seizure. Fifteen minutes later, mice were killed and the total metabolite levels and % 13 C enrichment were analyzed in the hippocampal formation using gas chromatography-mass spectrometry. Activities of key metabolic and antioxidant enzymes and the phosphorylation status of pyruvate dehydrogenase were measured, along with lipid peroxidation. RESULTS During seizures, total lactate levels increased 1.7-fold; however, [M + 3] enrichment of both lactate and alanine were reduced by 30% and 43%, respectively, along with a 28% decrease in phosphofructokinase activity. Postictally the % 13 C enrichments of all measured tricarboxylic acid (TCA) cycle intermediates and the amino acids were reduced by 46-93%. At this time, pyruvate dehydrogenase (PDH) activity was 56% of that measured in controls, and there was a 1.9-fold increase in the phosphorylation of PDH at ser232. Phosphorylation of PDH is known to decrease its activity. SIGNIFICANCE Here, we show that the increase of lactate levels during flurothyl seizures is from a source other than [U-13 C]-glucose, such as glycogen. Surprisingly, although we saw a reduction in phosphofructokinase activity during the seizure, metabolism of [U-13 C]-glucose into the TCA cycle seemed unaffected. Similar to our recent findings in the chronic phase of the pilocarpine model, postictally the metabolism of glucose by glycolysis and the TCA cycle was impaired along with reduced PDH activity. Although this decrease in activity may be a protective mechanism to reduce oxidative stress, which is observed in the flurothyl model, ATP is critical to the recovery of ion and neurotransmitter balance and return to normal brain function. Thus we identified promising novel strategies to enhance energy metabolism and recovery from seizures.
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Affiliation(s)
- Tanya S McDonald
- Department of Pharmacology, School of Biomedical Sciences, The University of Queensland, St. Lucia, Queensland, Australia
| | - Karin Borges
- Department of Pharmacology, School of Biomedical Sciences, The University of Queensland, St. Lucia, Queensland, Australia
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10
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Bogren LK, Olson JM, Carpluk J, Moore JM, Drew KL. Resistance to systemic inflammation and multi organ damage after global ischemia/reperfusion in the arctic ground squirrel. PLoS One 2014; 9:e94225. [PMID: 24728042 PMCID: PMC3984146 DOI: 10.1371/journal.pone.0094225] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Accepted: 03/14/2014] [Indexed: 11/18/2022] Open
Abstract
INTRODUCTION Cardiac arrest (CA) and hemorrhagic shock (HS) are two clinically relevant situations where the body undergoes global ischemia as blood pressure drops below the threshold necessary for adequate organ perfusion. Resistance to ischemia/reperfusion (I/R) injury is a characteristic of hibernating mammals. The present study sought to determine if arctic ground squirrels (AGS) are protected from systemic inflammation and multi organ damage after CA- or HS-induced global I/R and if, for HS, this protection is dependent upon their hibernation season. METHODS For CA, rats and summer euthermic AGS (AGS-EU) were asphyxiated for 8 min, inducing CA. For HS, rats, AGS-EU, and winter interbout arousal AGS (AGS-IBA) were subject to HS by withdrawing blood to a mean arterial pressure of 35 mmHg and maintaining that pressure for 20 min before reperfusion with Ringers. For both I/R models, body temperature (Tb) was kept at 36.5-37.5°C. After reperfusion, animals were monitored for seven days (CA) or 3 hrs (HS) then tissues and blood were collected for histopathology, clinical chemistries, and cytokine level analysis (HS only). For the HS studies, additional groups of rats and AGS were monitored for three days after HS to access survival and physiological impairment. RESULTS Rats had increased serum markers of liver damage one hour after CA while AGS did not. For HS, AGS survived 72 hours after I/R whereas rats did not survive overnight. Additionally, only rats displayed an inflammatory response after HS. AGS maintained a positive base excess, whereas the base excess in rats was negative during and after hemorrhage. CONCLUSIONS Regardless of season, AGS are resistant to organ damage, systemic inflammation, and multi organ damage after systemic I/R and this resistance is not dependent on their ability to become decrease Tb during insult but may stem from an altered acid/base and metabolic response during I/R.
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Affiliation(s)
- Lori K Bogren
- Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America; Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America
| | - Jasmine M Olson
- Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America
| | - Joanna Carpluk
- Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America
| | - Jeanette M Moore
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America
| | - Kelly L Drew
- Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America; Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America
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11
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Singh AK, Jiang Y, Gupta S, Younus M, Ramzan M. Anti-Inflammatory Potency of Nano-Formulated Puerarin and Curcumin in Rats Subjected to the Lipopolysaccharide-Induced Inflammation. J Med Food 2013; 16:899-911. [DOI: 10.1089/jmf.2012.0049] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Affiliation(s)
- Ashok K. Singh
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota
| | - Yin Jiang
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota
| | - Shveta Gupta
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota
| | - Mohamod Younus
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota
| | - Mohamod Ramzan
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota
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12
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Blouin AM, Fried I, Wilson CL, Staba RJ, Behnke EJ, Lam HA, Maidment NT, Karlsson KÆ, Lapierre JL, Siegel JM. Human hypocretin and melanin-concentrating hormone levels are linked to emotion and social interaction. Nat Commun 2013; 4:1547. [PMID: 23462990 PMCID: PMC3595130 DOI: 10.1038/ncomms2461] [Citation(s) in RCA: 169] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2012] [Accepted: 01/09/2013] [Indexed: 12/12/2022] Open
Abstract
The neurochemical changes underlying human emotions and social behaviour are largely unknown. Here we report on the changes in the levels of two hypothalamic neuropeptides, hypocretin-1 and melanin-concentrating hormone, measured in the human amygdala. We show that hypocretin-1 levels are maximal during positive emotion, social interaction and anger, behaviours that induce cataplexy in human narcoleptics. In contrast, melanin-concentrating hormone levels are minimal during social interaction, but are increased after eating. Both peptides are at minimal levels during periods of postoperative pain despite high levels of arousal. Melanin-concentrating hormone levels increase at sleep onset, consistent with a role in sleep induction, whereas hypocretin-1 levels increase at wake onset, consistent with a role in wake induction. Levels of these two peptides in humans are not simply linked to arousal, but rather to specific emotions and state transitions. Other arousal systems may be similarly emotionally specialized.
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Affiliation(s)
- Ashley M. Blouin
- Department of Psychiatry and Biobehavioral Sciences, University of California at Los Angeles, Los Angeles, CA 90095
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University, Baltimore, Maryland 21205
| | - Itzhak Fried
- Department of Neurosurgery, University of California at Los Angeles, Los Angeles, CA 90095
- Brain Research Institute, University of California at Los Angeles, Los Angeles, CA 90095
| | - Charles L. Wilson
- Brain Research Institute, University of California at Los Angeles, Los Angeles, CA 90095
- Department of Neurology, University of California at Los Angeles, Los Angeles, CA 90095
| | - Richard J. Staba
- Department of Neurology, University of California at Los Angeles, Los Angeles, CA 90095
| | - Eric J. Behnke
- Department of Neurosurgery, University of California at Los Angeles, Los Angeles, CA 90095
| | - Hoa A. Lam
- Department of Psychiatry and Biobehavioral Sciences, University of California at Los Angeles, Los Angeles, CA 90095
| | - Nigel T. Maidment
- Department of Psychiatry and Biobehavioral Sciences, University of California at Los Angeles, Los Angeles, CA 90095
- Brain Research Institute, University of California at Los Angeles, Los Angeles, CA 90095
| | - Karl Æ. Karlsson
- Department of Psychiatry and Biobehavioral Sciences, University of California at Los Angeles, Los Angeles, CA 90095
- Dept of Biomedical Engineering, School of Science and Engineering, Reykjavik University, Reykjavik, Iceland
| | - Jennifer L. Lapierre
- Department of Psychiatry and Biobehavioral Sciences, University of California at Los Angeles, Los Angeles, CA 90095
| | - Jerome M. Siegel
- Department of Psychiatry and Biobehavioral Sciences, University of California at Los Angeles, Los Angeles, CA 90095
- Brain Research Institute, University of California at Los Angeles, Los Angeles, CA 90095
- Neurobiology Research, Veterans Administration Greater Los Angeles Healthcare System, 16111 Plummer St., North Hills, CA 91343
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Patel M, Liang LP, Hou H, Williams BB, Kmiec M, Swartz HM, Fessel JP, Roberts LJ. Seizure-induced formation of isofurans: novel products of lipid peroxidation whose formation is positively modulated by oxygen tension. J Neurochem 2007; 104:264-70. [PMID: 17953661 DOI: 10.1111/j.1471-4159.2007.04974.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We have previously shown that seizures induce the formation of F(2)-isoprostanes (F(2)-IsoPs), one of the most reliable indices of oxidative stress in vivo. Isofurans (IsoFs) are novel products of lipid peroxidation whose formation is favored by high oxygen tensions. In contrast, high oxygen tensions suppress the formation of F(2)-IsoPs. The present study determined seizure-induced formation of IsoFs and its relationship with cellular oxygen levels (pO2). Status epilepticus (SE) resulted in F(2)-IsoP and IsoF formation, with overlapping but distinct time courses in hippocampal subregions. IsoF, but not F(2)-IsoP formation coincided with mitochondrial oxidative stress. SE resulted in a transient decrease in hippocampal pO2 measured by in vivo electron paramagnetic resonance oximetry suggesting an early phase of seizure-induced hypoxia. Seizure-induced F(2)-IsoP formation coincided with the peak hypoxia phase, whereas IsoF formation coincided with the 'reoxygenation' phase. These results demonstrate seizure-induced increase in IsoF formation and its correlation with changes in hippocampal pO2 and mitochondrial dysfunction.
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Affiliation(s)
- Manisha Patel
- Department of Pharmaceutical Sciences, University of Colorado Health Sciences Center, Denver, Colorado 80262, USA.
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14
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Papandreou D, Pavlou E, Kalimeri E, Mavromichalis I. The ketogenic diet in children with epilepsy. Br J Nutr 2007; 95:5-13. [PMID: 16441911 DOI: 10.1079/bjn20051591] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Children with epilepsy, especially those facing intractable seizures, experience a great impact on the quality of their lives. Effective treatment is essential, and although new anti-epileptic drugs have shown an improved profile of action, still a substantial number of children look for more efficacious ways of treatment that are far away from potential toxicity and ineffectiveness. The ketogenic diet is a dietary therapy for epileptic children based on manipulation of metabolism principles and brain energetics. This regimen aims to produce a controlled ketonaemia through excessive dietary fat intake, little carbohydrates and adequate (for growth) protein. The present paper is a review of previous and current papers regarding the proposed mechanisms of the ketogenic diet’s action, and the efficacy of the regimen on epileptic children. Unfortunately, a few small studies in sample size and duration tried to evaluate the potential risks of this regimen and their results were rather inconclusive. Further research needs to be done in order for the exact mechanism of the ketogenic diet to be clarified which will help to improve the diet’s application, especially for vulnerable epileptic children as far as their growth is concerned.
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Affiliation(s)
- D Papandreou
- Neurology Department, 2nd Pediatric Clinic, Medical School of Aristotelion University of Thessaloniki, Greece.
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15
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Mazzeo AT, Kunene NK, Choi S, Gilman C, Bullock RM. Quantitation of ischemic events after severe traumatic brain injury in humans: a simple scoring system. J Neurosurg Anesthesiol 2006; 18:170-8. [PMID: 16799343 DOI: 10.1097/01.ana.0000210999.18033.f6] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Cerebral ischemia is recognized as one of the most important mechanisms responsible for secondary brain damage following severe traumatic brain injury (TBI), contributing to an increased mortality and a worse neurologic outcome. METHOD A simple 5-item scoring system, taking into account the occurrence of specific potentially brain-damaging events (hypoxemia, hypotension, low cerebral blood flow, herniation, and low cerebral perfusion pressure) has been tested in a large population of severe TBI patients. Aims of this retrospective study were to validate the ability of the proposed ischemic score to predict neurologic outcome and to correlate the ischemic score with the results of microdialysis-based neurochemical monitoring and brain tissue oxygen monitoring. FINDINGS In a population of 172 severe TBI patients, a significant correlation was found between ischemic score and neurologic outcome, both at 3 months (r = -0.32; P < 0.01) and at 6 months (r = -0.31; P < 0.01). Significant correlations were also found with the most important neurochemical analytes. CONCLUSIONS The ischemic score proposed here, may be determined during the acute intensive care unit period, and correlates closely with outcome, which can only be determined 3 to 6 months, after injury. It also shows a correlation with neurochemical analytes.
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Affiliation(s)
- Anna Teresa Mazzeo
- Department of Neurosurgery, Medical College of Virginia, Virginia Commonwealth University, Richmond, 23219, USA.
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16
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Hillered L, Vespa PM, Hovda DA. Translational neurochemical research in acute human brain injury: the current status and potential future for cerebral microdialysis. J Neurotrauma 2005; 22:3-41. [PMID: 15665601 DOI: 10.1089/neu.2005.22.3] [Citation(s) in RCA: 223] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Microdialysis (MD) was introduced as an intracerebral sampling method for clinical neurosurgery by Hillered et al. and Meyerson et al. in 1990. Since then MD has been embraced as a research tool to measure the neurochemistry of acute human brain injury and epilepsy. In general investigators have focused their attention to relative chemical changes during neurointensive care, operative procedures, and epileptic seizure activity. This initial excitement surrounding this technology has subsided over the years due to concerns about the amount of tissue sampled and the complicated issues related to quantification. The interpretation of mild to moderate MD fluctuations in general remains an issue relating to dynamic changes of the architecture and size of the interstitial space, blood-brain barrier (BBB) function, and analytical imprecision, calling for additional validation studies and new methods to control for in vivo recovery variations. Consequently, the use of this methodology to influence clinical decisions regarding the care of patients has been restricted to a few institutions. Clinical studies have provided ample evidence that intracerebral MD monitoring is useful for the detection of overt adverse neurochemical conditions involving hypoxia/ischemia and seizure activity in subarachnoid hemorrhage (SAH), traumatic brain injury (TBI), thromboembolic stroke, and epilepsy. There is some data strongly suggesting that MD changes precede the onset of secondary neurological deterioration following SAH, hemispheric stroke, and surges of increased ICP in fulminant hepatic failure. These promising investigations have relied on MD-markers for disturbed glucose metabolism (glucose, lactate, and pyruvate) and amino acids. Others have focused on trying to capture other important neurochemical events, such as excitotoxicity, cell membrane degradation, reactive oxygen species (ROS) and nitric oxide (NO) formation, cellular edema, and BBB dysfunction. However, these other applications need additional validation. Although these cerebral events and their corresponding changes in neurochemistry are important, other promising MD applications, as yet less explored, comprise local neurochemical provocations, drug penetration to the human brain, MD as a tool in clinical drug trials, and for studying the proteomics of acute human brain injury. Nevertheless, MD has provided new important insights into the neurochemistry of acute human brain injury. It remains one of very few methods for neurochemical measurements in the interstitial compartment of the human brain and will continue to be a valuable translational research tool for the future. Therefore, this technology has the potential of becoming an established part of multimodality neuro-ICU monitoring, contributing unique information about the acute brain injury process. However, in order to reach this stage, several issues related to quantification and bedside presentation of MD data, implantation strategies, and quality assurance need to be resolved. The future success of MD as a diagnostic tool in clinical neurosurgery depends heavily on the choice of biomarkers, their sensitivity, specificity, and predictive value for secondary neurochemical events, and the availability of practical bedside methods for chemical analysis of the individual markers. The purpose of this review was to summarize the results of clinical studies using cerebral MD in neurosurgical patients and to discuss the current status of MD as a potential method for use in clinical decision-making. The approach was to focus on adverse neurochemical conditions in the injured human brain and the MD biomarkers used to study those events. Methodological issues that appeared critical for the future success of MD as a routine intracerebral sampling method were addressed.
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Affiliation(s)
- Lars Hillered
- Division of Neurosurgery, Department of Surgery, The David Geffen UCLA School of Medicine, Los Angeles, California, USA.
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17
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Patel M. Mitochondrial dysfunction and oxidative stress: cause and consequence of epileptic seizures. Free Radic Biol Med 2004; 37:1951-62. [PMID: 15544915 DOI: 10.1016/j.freeradbiomed.2004.08.021] [Citation(s) in RCA: 253] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2004] [Revised: 08/27/2004] [Accepted: 08/27/2004] [Indexed: 11/27/2022]
Abstract
Mitochondrial dysfunction has been implicated as a contributing factor in diverse acute and chronic neurological disorders. However, its role in the epilepsies has only recently emerged. Animal studies show that epileptic seizures result in free radical production and oxidative damage to cellular proteins, lipids, and DNA. Mitochondria contribute to the majority of seizure-induced free radical production. Seizure-induced mitochondrial superoxide production, consequent inactivation of susceptible iron-sulfur enzymes, e.g., aconitase, and resultant iron-mediated toxicity may mediate seizure-induced neuronal death. Epileptic seizures are a common feature of mitochondrial dysfunction associated with mitochondrial encephalopathies. Recent work suggests that chronic mitochondrial oxidative stress and resultant dysfunction can render the brain more susceptible to epileptic seizures. This review focuses on the emerging role of oxidative stress and mitochondrial dysfunction both as a consequence and as a cause of epileptic seizures.
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Affiliation(s)
- Manisha Patel
- Department of Pharmaceutical Sciences, University of Colorado Health Sciences Center, 4200 East Ninth Avenue, Denver, CO 80262, USA.
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18
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Mantis JG, Centeno NA, Todorova MT, McGowan R, Seyfried TN. Management of multifactorial idiopathic epilepsy in EL mice with caloric restriction and the ketogenic diet: role of glucose and ketone bodies. Nutr Metab (Lond) 2004; 1:11. [PMID: 15507133 PMCID: PMC529249 DOI: 10.1186/1743-7075-1-11] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2004] [Accepted: 10/19/2004] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND: The high fat, low carbohydrate ketogenic diet (KD) was developed as an alternative to fasting for seizure management. While the mechanisms by which fasting and the KD inhibit seizures remain speculative, alterations in brain energy metabolism are likely involved. We previously showed that caloric restriction (CR) inhibits seizure susceptibility by reducing blood glucose in the epileptic EL mouse, a natural model for human multifactorial idiopathic epilepsy. In this study, we compared the antiepileptic and anticonvulsant efficacy of the KD with that of CR in adult EL mice with active epilepsy. EL mice that experienced at least 15 recurrent complex partial seizures were fed either a standard diet unrestricted (SD-UR) or restricted (SD-R), and either a KD unrestricted (KD-UR) or restricted (KD-R). All mice were fasted for 14 hrs prior to diet initiation. A new experimental design was used where each mouse in the diet-restricted groups served as its own control to achieve a 20-23% body weight reduction. Seizure susceptibility, body weights, and the levels of plasma glucose and beta-hydroxybutyrate were measured once/week over a nine-week treatment period. RESULTS: Body weights and blood glucose levels remained high over the testing period in the SD-UR and the KD-UR groups, but were significantly (p < 0.001) reduced in the SD-R and KD-R groups. Plasma beta-hydroxybutyrate levels were significantly (p < 0.001) increased in the SD-R and KD-R groups compared to their respective UR groups. Seizure susceptibility remained high in both UR-fed groups throughout the study, but was significantly reduced after three weeks in both R-fed groups. CONCLUSIONS: The results indicate that seizure susceptibility in EL mice is dependent on plasma glucose levels and that seizure control is more associated with the amount than with the origin of dietary calories. Also, CR underlies the antiepileptic and anticonvulsant action of the KD in EL mice. A transition from glucose to ketone bodies for energy is predicted to manage EL epileptic seizures through multiple integrated changes of inhibitory and excitatory neural systems.
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Affiliation(s)
- John G Mantis
- Biology Department, Boston College, Chestnut Hill, MA, USA
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Tolias CM, Reinert M, Seiler R, Gilman C, Scharf A, Bullock MR. Normobaric hyperoxia--induced improvement in cerebral metabolism and reduction in intracranial pressure in patients with severe head injury: a prospective historical cohort-matched study. J Neurosurg 2004; 101:435-44. [PMID: 15352601 DOI: 10.3171/jns.2004.101.3.0435] [Citation(s) in RCA: 193] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
OBJECT The effect of normobaric hyperoxia (fraction of inspired O2 [FIO2] concentration 100%) in the treatment of patients with traumatic brain injury (TBI) remains controversial. The aim of this study was to investigate the effects of normobaric hyperoxia on five cerebral metabolic indices, which have putative prognostic significance following TBI in humans. METHODS At two independent neurointensive care units, the authors performed a prospective study of 52 patients with severe TBI who were treated for 24 hours with 100% FIO2, starting within 6 hours of admission. Data for these patients were compared with data for a cohort of 112 patients who were treated in the past; patients in the historical control group matched the patients in our study according to their Glasgow Coma Scale scores after resuscitation and their intracranial pressure within the first 8 hours after admission. Patients were monitored with the aid of intracerebral microdialysis and tissue O2 probes. Normobaric hyperoxia treatment resulted in a significant improvement in biochemical markers in the brain compared with the baseline measures for patients treated in our study (patients acting as their own controls) and also compared with findings from the historical control group. In the dialysate the glucose levels increased (369.02 +/- 20.1 micromol/L in the control group and 466.9 +/- 20.39 micromol/L in the 100% O2 group, p = 0.001), whereas the glutamate and lactate levels significantly decreased (p < 0.005). There were also reductions in the lactate/glucose and lactate/pyruvate ratios. Intracranial pressure in the treatment group was reduced significantly both during and after hyperoxia treatment compared with the control groups (15.03 +/- 0.8 mm Hg in the control group and 12.13 +/- 0.75 mm Hg in the 100% O2 group, p < 0.005) with no changes in cerebral perfusion pressure. Outcomes of the patients in the treatment group improved. CONCLUSIONS The results of the study support the hypothesis that normobaric hyperoxia in patients with severe TBI improves the indices of brain oxidative metabolism. Based on these data further mechanistic studies and a prospective randomized controlled trial are warranted.
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Affiliation(s)
- Christos M Tolias
- Harold F. Young Neurosurgical Center, Medical College of Virginia, Virginia Commonwealth University, Richmond, Virginia 23298, USA
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Greene AE, Todorova MT, Seyfried TN. Perspectives on the metabolic management of epilepsy through dietary reduction of glucose and elevation of ketone bodies. J Neurochem 2003; 86:529-37. [PMID: 12859666 DOI: 10.1046/j.1471-4159.2003.01862.x] [Citation(s) in RCA: 123] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Brain cells are metabolically flexible because they can derive energy from both glucose and ketone bodies (acetoacetate and beta-hydroxybutyrate). Metabolic control theory applies principles of bioenergetics and genome flexibility to the management of complex phenotypic traits. Epilepsy is a complex brain disorder involving excessive, synchronous, abnormal electrical firing patterns of neurons. We propose that many epilepsies with varied etiologies may ultimately involve disruptions of brain energy homeostasis and are potentially manageable through principles of metabolic control theory. This control involves moderate shifts in the availability of brain energy metabolites (glucose and ketone bodies) that alter energy metabolism through glycolysis and the tricarboxylic acid cycle, respectively. These shifts produce adjustments in gene-linked metabolic networks that manage or control the seizure disorder despite the continued presence of the inherited or acquired factors responsible for the epilepsy. This hypothesis is supported by information on the management of seizures with diets including fasting, the ketogenic diet and caloric restriction. A better understanding of the compensatory genetic and neurochemical networks of brain energy metabolism may produce novel antiepileptic therapies that are more effective and biologically friendly than those currently available.
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Affiliation(s)
- Amanda E Greene
- Boston College Biology Department, Chestnut Hill, Massachusetts, USA
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