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Coupling of GABA Metabolism to Mitochondrial Glucose Phosphorylation. Neurochem Res 2021; 47:470-480. [PMID: 34623563 DOI: 10.1007/s11064-021-03463-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 09/15/2021] [Accepted: 10/04/2021] [Indexed: 10/20/2022]
Abstract
Glucose and oxygen (O2) are vital to the brain. Glucose metabolism and mitochondria play a pivotal role in this process, culminating in the increase of reactive O2 species. Hexokinase (HK) is a key enzyme on glucose metabolism and is coupled to the brain mitochondrial redox modulation by recycling ADP for oxidative phosphorylation (OXPHOS). GABA shunt is an alternative pathway to GABA metabolism that increases succinate levels, a Krebs cycle intermediate. Although glucose and GABA metabolisms are intrinsically connected, their interplay coordinating mitochondrial function is poorly understood. Here, we hypothesize that the HK and the GABA shunt interact to control mitochondrial metabolism differently in the cortex and the hypothalamus. The GABA shunt stimulated mitochondrial O2 consumption and H2O2 production higher in hypothalamic synaptosomes (HSy) than cortical synaptosomes (CSy). The GABA shunt increased the HK coupled to OXPHOS activity in both population of synaptosomes, but the rate of activation was higher in HSy than CSy. Significantly, malonate and vigabatrin blocked the effects of the GABA shunt in the HK activity coupled to OXPHOS. It indicates that the glucose phosphorylation is linked to GABA and Krebs cycle reactions. Together, these data shed light on the HK and SDH role on the metabolism of each region fed by GABA turnover, which depends on the neurons' metabolic route.
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Serpa RO, Ferguson L, Larson C, Bailard J, Cooke S, Greco T, Prins ML. Pathophysiology of Pediatric Traumatic Brain Injury. Front Neurol 2021; 12:696510. [PMID: 34335452 PMCID: PMC8319243 DOI: 10.3389/fneur.2021.696510] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 06/21/2021] [Indexed: 11/23/2022] Open
Abstract
The national incidence of traumatic brain injury (TBI) exceeds that of any other disease in the pediatric population. In the United States the Centers for Disease Control and Prevention (CDC) reports 697,347 annual TBIs in children ages 0–19 that result in emergency room visits, hospitalization or deaths. There is a bimodal distribution within the pediatric TBI population, with peaks in both toddlers and adolescents. Preclinical TBI research provides evidence for age differences in acute pathophysiology that likely contribute to long-term outcome differences between age groups. This review will examine the timecourse of acute pathophysiological processes during cerebral maturation, including calcium accumulation, glucose metabolism and cerebral blood flow. Consequences of pediatric TBI are complicated by the ongoing maturational changes allowing for substantial plasticity and windows of vulnerabilities. This review will also examine the timecourse of later outcomes after mild, repeat mild and more severe TBI to establish developmental windows of susceptibility and altered maturational trajectories. Research progress for pediatric TBI is critically important to reveal age-associated mechanisms and to determine knowledge gaps for future studies.
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Affiliation(s)
- Rebecka O Serpa
- Department of Neurosurgery, Brain Injury Research Center, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States.,Steve Tisch BrainSPORT Program, University of California, Los Angeles, Los Angeles, CA, United States
| | - Lindsay Ferguson
- Department of Neurosurgery, Brain Injury Research Center, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States.,Steve Tisch BrainSPORT Program, University of California, Los Angeles, Los Angeles, CA, United States
| | - Cooper Larson
- Department of Neurosurgery, Brain Injury Research Center, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States.,Steve Tisch BrainSPORT Program, University of California, Los Angeles, Los Angeles, CA, United States
| | - Julie Bailard
- Department of Neurosurgery, Brain Injury Research Center, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States.,Steve Tisch BrainSPORT Program, University of California, Los Angeles, Los Angeles, CA, United States
| | - Samantha Cooke
- Department of Neurosurgery, Brain Injury Research Center, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States.,Steve Tisch BrainSPORT Program, University of California, Los Angeles, Los Angeles, CA, United States
| | - Tiffany Greco
- Department of Neurosurgery, Brain Injury Research Center, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States.,Steve Tisch BrainSPORT Program, University of California, Los Angeles, Los Angeles, CA, United States
| | - Mayumi L Prins
- Department of Neurosurgery, Brain Injury Research Center, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States.,Steve Tisch BrainSPORT Program, University of California, Los Angeles, Los Angeles, CA, United States
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Kloss O, Eskin NM, Suh M. Thiamin deficiency on fetal brain development with and without prenatal alcohol exposure. Biochem Cell Biol 2018; 96:169-177. [DOI: 10.1139/bcb-2017-0082] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Adequate thiamin levels are crucial for optimal health through maintenance of homeostasis and viability of metabolic enzymes, which require thiamine as a co-factor. Thiamin deficiency occurs during pregnancy when the dietary intake is inadequate or excessive alcohol is consumed. Thiamin deficiency leads to brain dysfunction because thiamin is involved in the synthesis of myelin and neurotransmitters (e.g., acetylcholine, γ-aminobutyric acid, glutamate), and its deficiency increases oxidative stress by decreasing the production of reducing agents. Thiamin deficiency also leads to neural membrane dysfunction, because thiamin is a structural component of mitochondrial and synaptosomal membranes. Similarly, in-utero exposure to alcohol leads to fetal brain dysfunction, resulting in negative effects such as fetal alcohol spectrum disorder (FASD). Thiamin deficiency and prenatal exposure to alcohol could act synergistically to produce negative effects on fetal development; however, this area of research is currently under-studied. This minireview summarizes the evidence for the potential role of thiamin deficiency in fetal brain development, with or without prenatal exposure to alcohol. Such evidence may influence the development of new nutritional strategies for preventing or mitigating the symptoms of FASD.
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Affiliation(s)
- Olena Kloss
- Department of Human Nutritional Sciences, St. Boniface Hospital Research Centre, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
- Department of Human Nutritional Sciences, St. Boniface Hospital Research Centre, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - N.A. Michael Eskin
- Department of Human Nutritional Sciences, St. Boniface Hospital Research Centre, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
- Department of Human Nutritional Sciences, St. Boniface Hospital Research Centre, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Miyoung Suh
- Department of Human Nutritional Sciences, St. Boniface Hospital Research Centre, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
- Department of Human Nutritional Sciences, St. Boniface Hospital Research Centre, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
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McKenna MC, Scafidi S, Robertson CL. Metabolic Alterations in Developing Brain After Injury: Knowns and Unknowns. Neurochem Res 2015; 40:2527-43. [PMID: 26148530 PMCID: PMC4961252 DOI: 10.1007/s11064-015-1600-7] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Revised: 04/10/2015] [Accepted: 05/02/2015] [Indexed: 12/21/2022]
Abstract
Brain development is a highly orchestrated complex process. The developing brain utilizes many substrates including glucose, ketone bodies, lactate, fatty acids and amino acids for energy, cell division and the biosynthesis of nucleotides, proteins and lipids. Metabolism is crucial to provide energy for all cellular processes required for brain development and function including ATP formation, synaptogenesis, synthesis, release and uptake of neurotransmitters, maintaining ionic gradients and redox status, and myelination. The rapidly growing population of infants and children with neurodevelopmental and cognitive impairments and life-long disability resulting from developmental brain injury is a significant public health concern. Brain injury in infants and children can have devastating effects because the injury is superimposed on the high metabolic demands of the developing brain. Acute injury in the pediatric brain can derail, halt or lead to dysregulation of the complex and highly regulated normal developmental processes. This paper provides a brief review of metabolism in developing brain and alterations found clinically and in animal models of developmental brain injury. The metabolic changes observed in three major categories of injury that can result in life-long cognitive and neurological disabilities, including neonatal hypoxia-ischemia, pediatric traumatic brain injury, and brain injury secondary to prematurity are reviewed.
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Affiliation(s)
- Mary C McKenna
- Department of Pediatrics and Program in Neuroscience, University of Maryland School of Medicine, 655 W. Baltimore St., Room 13-019, Baltimore, MD, 21201, USA.
| | - Susanna Scafidi
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Courtney L Robertson
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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5
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McKenna MC, Scafidi S, Robertson CL. Metabolic Alterations in Developing Brain After Injury: Knowns and Unknowns. Neurochem Res 2015. [PMID: 26148530 DOI: 10.1007/s11064‐015‐1600‐7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Brain development is a highly orchestrated complex process. The developing brain utilizes many substrates including glucose, ketone bodies, lactate, fatty acids and amino acids for energy, cell division and the biosynthesis of nucleotides, proteins and lipids. Metabolism is crucial to provide energy for all cellular processes required for brain development and function including ATP formation, synaptogenesis, synthesis, release and uptake of neurotransmitters, maintaining ionic gradients and redox status, and myelination. The rapidly growing population of infants and children with neurodevelopmental and cognitive impairments and life-long disability resulting from developmental brain injury is a significant public health concern. Brain injury in infants and children can have devastating effects because the injury is superimposed on the high metabolic demands of the developing brain. Acute injury in the pediatric brain can derail, halt or lead to dysregulation of the complex and highly regulated normal developmental processes. This paper provides a brief review of metabolism in developing brain and alterations found clinically and in animal models of developmental brain injury. The metabolic changes observed in three major categories of injury that can result in life-long cognitive and neurological disabilities, including neonatal hypoxia-ischemia, pediatric traumatic brain injury, and brain injury secondary to prematurity are reviewed.
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Affiliation(s)
- Mary C McKenna
- Department of Pediatrics and Program in Neuroscience, University of Maryland School of Medicine, 655 W. Baltimore St., Room 13-019, Baltimore, MD, 21201, USA.
| | - Susanna Scafidi
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Courtney L Robertson
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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6
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Acetyl-CoA the key factor for survival or death of cholinergic neurons in course of neurodegenerative diseases. Neurochem Res 2013; 38:1523-42. [PMID: 23677775 PMCID: PMC3691476 DOI: 10.1007/s11064-013-1060-x] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2013] [Revised: 04/19/2013] [Accepted: 04/22/2013] [Indexed: 12/24/2022]
Abstract
Glucose-derived pyruvate is a principal source of acetyl-CoA in all brain cells, through pyruvate dehydogenase complex (PDHC) reaction. Cholinergic neurons like neurons of other transmitter systems and glial cells, utilize acetyl-CoA for energy production in mitochondria and diverse synthetic pathways in their extramitochondrial compartments. However, cholinergic neurons require additional amounts of acetyl-CoA for acetylcholine synthesis in their cytoplasmic compartment to maintain their transmitter functions. Characteristic feature of several neurodegenerating diseases including Alzheimer’s disease and thiamine diphosphate deficiency encephalopathy is the decrease of PDHC activity correlating with cholinergic deficits and losses of cognitive functions. Such conditions generate acetyl-CoA deficits that are deeper in cholinergic neurons than in noncholinergic neuronal and glial cells, due to its additional consumption in the transmitter synthesis. Therefore, any neuropathologic conditions are likely to be more harmful for the cholinergic neurons than for noncholinergic ones. For this reason attempts preserving proper supply of acetyl-CoA in the diseased brain, should attenuate high susceptibility of cholinergic neurons to diverse neurodegenerative conditions. This review describes how common neurodegenerative signals could induce deficts in cholinergic neurotransmission through suppression of acetyl-CoA metabolism in the cholinergic neurons.
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Nilsen LH, Shi Q, Gibson GE, Sonnewald U. Brain [U-13 C]glucose metabolism in mice with decreased α-ketoglutarate dehydrogenase complex activity. J Neurosci Res 2011; 89:1997-2007. [PMID: 21374701 DOI: 10.1002/jnr.22606] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2010] [Revised: 12/16/2010] [Accepted: 01/09/2011] [Indexed: 01/24/2023]
Abstract
The activity of the α-ketoglutarate dehydrogenase complex (KGDHC), a mitochondrial enzyme complex that mediates the oxidative decarboxylation of α-ketoglutarate in the TCA cycle, is reduced in Alzheimer's disease. We investigated the metabolic effects of a partial KGDHC activity reduction on brain glucose metabolism using mice with disrupted expression of dihydrolipoyl succinyltransferase (DLST; gene encoding the E2k subunit of KGDHC). Brain tissue extracts from cortex and cerebellum of 6-week-old heterozygote DLST knockout mice (DLST+/-) and corresponding wild-type mice injected with [U-(13) C]glucose and decapitated 15 min later were analyzed. An increase in the concentration of glucose in cortex suggested a decrease in the cortical utilization of glucose in DLST+/- mice. Furthermore, the concentration and (13) C labelling of aspartate in cortex were reduced in DLST+/- mice. This decline was likely caused by a decrease in the pool of oxaloacetate. In contrast to results from cell culture studies, no indications of altered glycolysis or GABA shunt activity were found. Glucose metabolism in the cerebellum was unaffected by the decrease in KGDHC activity. Among metabolites not related to glucose metabolism, the concentration of taurine was decreased in the cortex, and that of tyrosine was increased in the cerebellum. These results imply that diminished KGDHC activity has the potential to induce the reduction in glucose utilization that is seen in several neurodegenerative diseases.
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Affiliation(s)
- Linn Hege Nilsen
- Department of Neuroscience, Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
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8
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Matsumoto Y, Ishida T, Takeda T, Koga T, Fujii M, Ishii Y, Fujimura Y, Miura D, Wariishi H, Yamada H. Maternal exposure to dioxin reduces hypothalamic but not pituitary metabolome in fetal rats: a possible mechanism for a fetus-specific reduction in steroidogenesis. J Toxicol Sci 2010; 35:365-73. [PMID: 20519845 DOI: 10.2131/jts.35.365] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) reduces the synthesis of pituitary gonadotropins in a fetal age-specific manner. The pituitary synthesis of gonadotropins is regulated by the hypothalamus and, thus, needs the differentiation and development of the hypothalamus requiring a number of factors including energy supply and neurotransmitters. To investigate the mechanism whereby TCDD reduces fetal gonadotropins, we carried out a comparative study on the metabolomes of the hypothalamus and pituitary using fetal and mature Wistar rats. Male fetuses at gestational day (GD)20 were removed from dams treated orally with TCDD (1 microg/kg) at GD15, and the metabolome profiles were analyzed by gas chromatography-mass spectrometry (GC-MS). The principal component analysis of GC-MS data revealed that TCDD caused a change in the profile of fetal metabolome more markedly in the hypothalamus than in the pituitary. In sharp contrast, TCDD did not cause any marked alteration in hypothalamic as well as pituitary metabolomes in male rats born of untreated dams and treated with TCDD at postnatal day 49. It was also demonstrated that a number of fetal hypothalamic components, including glutamine and gamma-aminobutyric acid, are reduced by TCDD. These results demonstrate a possibility that TCDD may reduce the metabolic activity of the hypothalamus in a fetus-specific fashion, resulting in the reduced synthesis of gonadotropins.
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Affiliation(s)
- Yuki Matsumoto
- Graduate School of Pharmaceutical Sciences, Kyushu University, Maidashi, Higashi-ku, Fukuoka, Japan.
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Yang L, Shi Q, Ho DJ, Starkov AA, Wille EJ, Xu H, Chen HL, Zhang S, Stack CM, Calingasan NY, Gibson GE, Beal MF. Mice deficient in dihydrolipoyl succinyl transferase show increased vulnerability to mitochondrial toxins. Neurobiol Dis 2009; 36:320-30. [PMID: 19660549 DOI: 10.1016/j.nbd.2009.07.023] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2009] [Revised: 07/08/2009] [Accepted: 07/28/2009] [Indexed: 11/24/2022] Open
Abstract
The activity of a key mitochondrial tricarboxylic acid cycle enzyme, alpha-ketoglutarate dehydrogenase complex (KGDHC), declines in many neurodegenerative diseases. KGDHC consists of three subunits. The dihydrolipoyl succinyl transferase (DLST) component is unique to KGDHC. DLST(+/-) mice showed reduced mRNA and protein levels and decreased brain mitochondrial KGDHC activity. Neurotoxic effects of mitochondrial toxins were exacerbated in DLST(+/-) mice. MPTP produced a significantly greater reduction of striatal dopamine and tyrosine hydroxylase-positive neurons in the substantia nigra pars compacta of DLST(+/-) mice. DLST deficiency enhanced the severity of lipid peroxidation in the substantia nigra after MPTP treatment. Striatal lesions induced by either malonate or 3-nitropropionic acid (3-NP) were significantly larger in DLST(+/-) mice than in wildtype controls. DLST deficiency enhanced the 3-NP inhibition of mitochondria enzymes, and 3-NP induced protein and DNA oxidations. These observations support the hypothesis that reductions in KGDHC may impair the adaptability of the brain and contribute to the pathogenesis of neurodegenerative diseases.
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Affiliation(s)
- Lichuan Yang
- Department of Neurology and Neuroscience, Weill Cornell Medical College, New York, NY 10065, USA
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Dukhande VV, Isaac AO, Chatterji T, Lai JCK. Reduced glutathione regenerating enzymes undergo developmental decline and sexual dimorphism in the rat cerebral cortex. Brain Res 2009; 1286:19-24. [PMID: 19450567 DOI: 10.1016/j.brainres.2009.05.029] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2009] [Revised: 04/30/2009] [Accepted: 05/07/2009] [Indexed: 02/08/2023]
Abstract
Oxidative stress during development may predispose humans to neurodegenerative disorders in old age. Moreover, numerous ailments of brain disproportionately affect one of the genders. We therefore hypothesized that, activities of enzymes regenerating and utilizing glutathione (GSH) show sexual dimorphism and developmental differences in rat brain. To test this hypothesis, we collected cortex tissue from male and female Sprague-Dawley rats at post-natal day (PN) 5, PN 10, PN 20, PN 30, and PN 60. We measured tissue levels of NADP-linked isocitrate dehydrogenase (NADP-ICDH), glucose-6-phosphate dehydrogenase (G6PDH), and, glutathione reductase (GR) by UV spectrophotometry and determined glutathione peroxidase (GPx) expression therein by western blotting. Our results showed that sexual maturation had an impact on activities of enzymes that regenerate and utilize GSH and rat female cortex had more anti-oxidant capacity. Moreover, age-related decline in the activities of these key enzymes were observed. Reduced glutathione and NADPH protects the brain from oxidative stress. Thus, our results may have implications for neurodegenerative disorders like Parkinson's disease and developmental disorders of brain like autism in which oxidative stress plays a key role.
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Affiliation(s)
- Vikas V Dukhande
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, Idaho State University, Pocatello, ID 83209-8334, USA
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Sauer SW. Biochemistry and bioenergetics of glutaryl-CoA dehydrogenase deficiency. J Inherit Metab Dis 2007; 30:673-80. [PMID: 17879145 DOI: 10.1007/s10545-007-0678-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2007] [Revised: 05/25/2007] [Accepted: 05/31/2007] [Indexed: 11/26/2022]
Abstract
Glutaryl-CoA dehydrogenase (GCDH) is a central enzyme in the catabolic pathway of L-tryptophan, L-lysine, and L-hydroxylysine which catalyses the oxidative decarboxylation of glutaryl-CoA to crotonyl-CoA and CO2. Glutaryl-CoA dehydrogenase deficiency (GDD) is an autosomal recessive disease characterized by the accumulation of glutaric and 3-hydroxyglutaric acids in tissues and body fluids. Untreated patients commonly present with severe striatal degeneration during encephalopathic crises. Previous studies have highlighted primary excitotoxicity as a trigger of striatal degeneration. The aim of this PhD study was to investigate in detail tissue-specific bioenergetic and biochemical parameters of GDD in vitro, post mortem, and in Gcdh-/- mice. The major bioenergetic finding was uncompetitive inhibition of alpha-ketoglutarate dehydrogenase complex by glutaryl-CoA. It is suggested that a synergism of primary and secondary excitotoxic effects in concert with age-related physiological changes in the developing brain underlie acute and chronic neurodegenerative changes in GDD patients. The major biochemical findings were highly elevated cerebral concentrations of glutaric and 3-hydroxyglutaric acid despite low permeability of the blood-brain barrier for these dicarboxylic acids. It can be postulated that glutaric and 3-hydroxyglutaric acids are synthesized de novo and subsequently trapped in the brain. In this light, neurological disease in GDD is not 'transported' to the brain in analogy with phenylketonuria or hepatic encephalopathy as suggested previously but is more likely to be induced by the intrinsic biochemical properties of the cerebral tissue and the blood-brain barrier.
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Affiliation(s)
- S W Sauer
- Department of General Pediatrics, Division of Inborn Metabolic Diseases, University Children's Hospital, Im Neuenheimer Feld 150, D-69120, Heidelberg, Germany.
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Robertson CL, Soane L, Siegel ZT, Fiskum G. The potential role of mitochondria in pediatric traumatic brain injury. Dev Neurosci 2006; 28:432-46. [PMID: 16943666 DOI: 10.1159/000094169] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2006] [Accepted: 04/03/2006] [Indexed: 01/08/2023] Open
Abstract
Mitochondria play a central role in cerebral energy metabolism, intracellular calcium homeostasis and reactive oxygen species generation and detoxification. Following traumatic brain injury (TBI), the degree of mitochondrial injury or dysfunction can be an important determinant of cell survival or death. Literature would suggest that brain mitochondria from the developing brain are very different from those from mature animals. Therefore, aspects of developmental differences in the mitochondrial response to TBI can make the immature brain more vulnerable to traumatic injury. This review will focus on four main areas of secondary injury after pediatric TBI, including excitotoxicity, oxidative stress, alterations in energy metabolism and cell death pathways. Specifically, we will describe what is known about developmental differences in mitochondrial function in these areas, in both the normal, physiologic state and the pathologic state after pediatric TBI. The ability to identify and target aspects of mitochondrial dysfunction could lead to novel neuroprotective therapies for infants and children after severe TBI.
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Affiliation(s)
- Courtney L Robertson
- Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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Sadakata T, Furuichi T. Identification and mRNA expression of Ogdh, QP-C, and two predicted genes in the postnatal mouse brain. Neurosci Lett 2006; 405:217-22. [PMID: 16901643 DOI: 10.1016/j.neulet.2006.07.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2006] [Revised: 06/23/2006] [Accepted: 07/03/2006] [Indexed: 11/26/2022]
Abstract
By fluorescent differential display, we identified six transcripts (CAPS2/Cadps2, Cdh22, b1402, c1502, d1401, and d1501) that showed the differential expression patterns during the postnatal development of the mouse cerebellum. We further analyzed the latter four transcripts whose cellular localizations in developing mouse brains have not been studied. In the postnatal cerebellum, clones c1502 and d1501 were transiently up-regulated; clone b1402 was up-regulated; and clone d1401 remained relatively constant. Sequence analysis revealed that d1401 and c1502 were derivatives of Ogdh (oxoglutarate dehydrogenase) and QP-C (ubiquinol-cytochrome c reductase complex ubiquinone-binding protein), respectively. Moreover, b1402 and d1501 were identified as transcripts of a predicted gene (4933409K07Rik) and a novel EST, respectively. b1402 and d1501 were abundantly present in the cerebellum, whereas c1502/QP-C and d1401/Ogdh were widely distributed in various mouse tissues. In the postnatal mouse brain, moderately high mRNA levels of b1402 were restricted to the olfactory bulb, striatum, cerebral cortex (layers II-III and VI), hippocampus (dentate granule cells), and cerebellum (granule cells). c1502/QP-C mRNA was localized at high levels in the olfactory bulb, cerebral cortex, hippocampus, thalamus (anterodorsal nucleus, parafacicularis nucleus), tegmentum (red nucleus), cerebellum (Purkinje and granule cells), and pons (pontine nucleus, reticulotegmental nucleus, trapezoid body, vestibular nucleus). High mRNA levels of d1401/Ogdh were observed in the olfactory bulb, hippocampus, cerebellum, and pons, whereas those of d1501 were detected in the granule cells of the olfactory bulb, dentate gyrus, and cerebellum.
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Affiliation(s)
- Tetsushi Sadakata
- Laboratory for Molecular Neurogenesis, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
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N/A. N/A. Shijie Huaren Xiaohua Zazhi 2005; 13:2667-2671. [DOI: 10.11569/wcjd.v13.i22.2667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/26/2023] Open
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Sauer SW, Okun JG, Schwab MA, Crnic LR, Hoffmann GF, Goodman SI, Koeller DM, Kölker S. Bioenergetics in glutaryl-coenzyme A dehydrogenase deficiency: a role for glutaryl-coenzyme A. J Biol Chem 2005; 280:21830-6. [PMID: 15840571 DOI: 10.1074/jbc.m502845200] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Inherited deficiency of glutaryl-CoA dehydrogenase results in an accumulation of glutaryl-CoA, glutaric, and 3-hydroxyglutaric acids. If untreated, most patients suffer an acute encephalopathic crisis and, subsequently, acute striatal damage being precipitated by febrile infectious diseases during a vulnerable period of brain development (age 3 and 36 months). It has been suggested before that some of these organic acids may induce excitotoxic cell damage, however, the relevance of bioenergetic impairment is not yet understood. The major aim of our study was to investigate respiratory chain, tricarboxylic acid cycle, and fatty acid oxidation in this disease using purified single enzymes and tissue homogenates from Gcdh-deficient and wild-type mice. In purified enzymes, glutaryl-CoA but not glutaric or 3-hydroxyglutaric induced an uncompetitive inhibition of alpha-ketoglutarate dehydrogenase complex activity. Notably, reduced activity of alpha-ketoglutarate dehydrogenase activity has recently been demonstrated in other neurodegenerative diseases, such as Alzheimer, Parkinson, and Huntington diseases. In contrast to alpha-ketoglutarate dehydrogenase complex, no direct inhibition of glutaryl-CoA, glutaric acid, and 3-hydroxyglutaric acid was found in other enzymes tested. In Gcdh-deficient mice, respiratory chain and tricarboxylic acid activities remained widely unaffected, virtually excluding regulatory changes in these enzymes. However, hepatic activity of very long-chain acyl-CoA dehydrogenase was decreased and concentrations of long-chain acylcarnitines increased in the bile of these mice, which suggested disturbed oxidation of long-chain fatty acids. In conclusion, our results demonstrate that bioenergetic impairment may play an important role in the pathomechanisms underlying neurodegenerative changes in glutaryl-CoA dehydrogenase deficiency.
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Affiliation(s)
- Sven W Sauer
- Department of General Pediatrics, Division of Inborn Metabolic Diseases, University Children's Hospital of Heidelberg, Im Neuenheimer Feld 150, D-69120 Heidelberg, Germany
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Farahani R, Pina-Benabou MH, Kyrozis A, Siddiq A, Barradas PC, Chiu FC, Cavalcante LA, Lai JCK, Stanton PK, Rozental R. Alterations in metabolism and gap junction expression may determine the role of astrocytes as ?good samaritans? or executioners. Glia 2005; 50:351-361. [PMID: 15846800 DOI: 10.1002/glia.20213] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Our knowledge of astroglia and their physiological and pathophysiological role(s) in the central nervous system (CNS) has grown during the past decade, revealing a complex picture. It is becoming increasingly clear that glia play a significant role in the homeostasis and function of the CNS and that neurons should no longer be considered the only cell type that responds, both rapidly and slowly, to electrochemical activity. We discuss recent advances in the field with an emphasis on the impact of hypoxia and ischemia on astrocytic metabolism and the functional relationship between glucose metabolism and gap junctions in astrocytes. We also address the controversy over whether astrocytic gap junctions mediate protection or killing of neurons during or after hypoxic or ischemic insults.
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Affiliation(s)
- Reza Farahani
- Department of Pediatrics, Albert Einstein College of Medicine, Bronx, New York
| | - Mara H Pina-Benabou
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, New York
| | - Andreas Kyrozis
- Department of Neurology, Albert Einstein College of Medicine, Bronx, New York
| | - Ayesha Siddiq
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, New York
| | - Penha C Barradas
- Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Fung-Chow Chiu
- Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, Georgia
| | - Leny A Cavalcante
- Instituto de Biofisica C. Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - James C K Lai
- Department of Pharmaceutical Sciences, College of Pharmacy, Idaho State University, Pocatello, Idaho
| | - Patric K Stanton
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, New York
- Department of Neurology, New York Medical College, Valhalla, New York
| | - Renato Rozental
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, New York
- Department of Obstetrics and Anesthesiology, New York Medical College, Valhalla, New York
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Kannurpatti SS, Sanganahalli BG, Mishra S, Joshi PG, Joshi NB. Glutamate-induced differential mitochondrial response in young and adult rats. Neurochem Int 2004; 44:361-9. [PMID: 14643754 DOI: 10.1016/s0197-0186(03)00164-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Excitatory amino acid glutamate is involved in neurotransmission in the nervous system but it becomes a potent neurotoxin under variety of conditions. However, the molecular mechanism of excitotoxicity is not known completely. We have studied the influence of glutamate on intracellular calcium and mitochondrial functions in cortical slices from young and adult rats. The slices from both the age groups exhibited comparable intracellular calcium changes upon glutamate stimulation. Glutamate treatment caused a decrease in adenosine 5'-diphosphate/adenosine 5'-triphosphate (ADP/ATP) and an increase in nicotinamide adenine dinucleotide/nicotinamide adenine dinucleotide reduced form (NAD/NADH) ratio in both the age groups but the magnitude and the nature of temporal change was different. Glutamate-induced decrease in ATP/ADP and increase in NAD/NADH ratio was significantly higher in slices from the adult as compared to the young rats. The slices from young rats elicited slightly higher mitochondrial depolarization than adult rats. However, the formation of reactive oxygen species (ROS) and lactate dehydrogenase (LDH) release were significantly higher in adult rats as compared to young rats. Glutamate-induced mitochondrial depolarization, ROS formation and LDH release were highly dependent on the presence of Ca(2+) in the extracellular medium. The treatment of slices with mitochondrial inhibitors rotenone and oligomycin inhibited ROS formation and LDH release substantially. Our results suggest that the glutamate-induced increase in intracellular calcium is not the only factor responsible for neuronal cell death but the mitochondrial functions could be crucial in excitotoxicity.
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Affiliation(s)
- S S Kannurpatti
- Department of Biophysics, National Institute of Mental Health and Neuro Sciences, Bangalore 560 029, India
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Lai JCK, White BK, Buerstatte CR, Haddad GG, Novotny EJ, Behar KL. Chronic hypoxia in development selectively alters the activities of key enzymes of glucose oxidative metabolism in brain regions. Neurochem Res 2003; 28:933-40. [PMID: 12718448 DOI: 10.1023/a:1023235712524] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The immature brain is more resistant to hypoxia/ischemia than the mature brain. Although chronic hypoxia can induce adaptive-changes on the developing brain, the mechanisms underlying such adaptive changes are poorly understood. To further elucidate some of the adaptive changes during postnatal hypoxia, we determined the activities of four enzymes of glucose oxidative metabolism in eight brain regions of hypoxic and normoxic rats. Litters of Sprague-Dawley rats were put into the hypoxic chamber (oxygen level maintained at 9.5%) with their dams starting on day 3 postnatal (P3). Age-matched normoxic rats were use as control animals. In P10 hypoxic rats, lactate dehydrogenase (LDH) activity in cerebral cortex, striatum, olfactory bulb, hippocampus, hypothalamus, pons and medulla, and cerebellum was significantly increased (by 100%-370%) compared to those in P10 normoxic rats. In P10 hypoxic rats, hexokinase (HK) activity in hypothalamus, hippocampus, olfactory bulb, midbrain, and cerebral cortex was significantly decreased (by 15%-30%). Neither alpha-ketoglutarate dehydrogenase complex (KGDHC, which is believed to have an important role in the regulation of the tricarboxylic acid [TCA] cycle flux) nor citrate synthase (CS) activity was significantly decreased in the eight regions of P10 hypoxic rats compared to those in P10 normoxic rats. In P30 hypoxic rats, LDH activity was only increased in striatum (by 19%), whereas HK activity was only significantly decreased (by 30%) in this region. However, KGDHC activity was significantly decreased in olfactory bulb, hippocampus, hypothalamus, cerebral cortex, and cerebellum (by 20%-40%) in P30 hypoxic rats compared to those in P30 normoxic rats. Similarly, CS activity was decreased, but only in olfactory bulb, hypothalamus, and midbrain (by 9%-21%) in P30 hypoxic rats. Our results suggest that at least some of the mechanisms underlying the hypoxia-induced changes in activities of glycolytic enzymes implicate the upregulation of HIF-1. Moreover, our observation that chronic postnatal hypoxia induces differential effects on brain glycolytic and TCA cycle enzymes may have pathophysiological implications (e.g., decreased in energy metabolism) in childhood diseases (e.g., sudden infant death syndrome) in which hypoxia plays a role.
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Affiliation(s)
- James C K Lai
- Department of Pharmaceutical Sciences, College of Pharmacy, Idaho State University, Pocatello, Idaho 83209-8334, USA.
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