1
|
Fernández de la Torre M, Fiuza-Luces C, Laine-Menéndez S, Delmiro A, Arenas J, Martín MÁ, Lucia A, Morán M. Pathophysiology of Cerebellar Degeneration in Mitochondrial Disorders: Insights from the Harlequin Mouse. Int J Mol Sci 2023; 24:10973. [PMID: 37446148 DOI: 10.3390/ijms241310973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Revised: 06/22/2023] [Accepted: 06/28/2023] [Indexed: 07/15/2023] Open
Abstract
By means of a proteomic approach, we assessed the pathways involved in cerebellar neurodegeneration in a mouse model (Harlequin, Hq) of mitochondrial disorder. A differential proteomic profile study (iTRAQ) was performed in cerebellum homogenates of male Hq and wild-type (WT) mice 8 weeks after the onset of clear symptoms of ataxia in the Hq mice (aged 5.2 ± 0.2 and 5.3 ± 0.1 months for WT and Hq, respectively), followed by a biochemical validation of the most relevant changes. Additional groups of 2-, 3- and 6-month-old WT and Hq mice were analyzed to assess the disease progression on the proteins altered in the proteomic study. The proteomic analysis showed that beyond the expected deregulation of oxidative phosphorylation, the cerebellum of Hq mice showed a marked astroglial activation together with alterations in Ca2+ homeostasis and neurotransmission, with an up- and downregulation of GABAergic and glutamatergic neurotransmission, respectively, and the downregulation of cerebellar "long-term depression", a synaptic plasticity phenomenon that is a major player in the error-driven learning that occurs in the cerebellar cortex. Our study provides novel insights into the mechanisms associated with cerebellar degeneration in the Hq mouse model, including a complex deregulation of neuroinflammation, oxidative phosphorylation and glutamate, GABA and amino acids' metabolism.
Collapse
Affiliation(s)
- Miguel Fernández de la Torre
- Mitochondrial and Neuromuscular Diseases Laboratory, Instituto de Investigación Sanitaria Hospital '12 de Octubre' ('imas12'), 28041 Madrid, Spain
| | - Carmen Fiuza-Luces
- Mitochondrial and Neuromuscular Diseases Laboratory, Instituto de Investigación Sanitaria Hospital '12 de Octubre' ('imas12'), 28041 Madrid, Spain
| | - Sara Laine-Menéndez
- Mitochondrial and Neuromuscular Diseases Laboratory, Instituto de Investigación Sanitaria Hospital '12 de Octubre' ('imas12'), 28041 Madrid, Spain
| | - Aitor Delmiro
- Mitochondrial and Neuromuscular Diseases Laboratory, Instituto de Investigación Sanitaria Hospital '12 de Octubre' ('imas12'), 28041 Madrid, Spain
- Spanish Network for Biomedical Research in Rare Diseases (CIBERER), U723, 28029 Madrid, Spain
- Servicio de Bioquímica Clínica, Hospital Universitario "12 de Octubre", 28041 Madrid, Spain
| | - Joaquín Arenas
- Mitochondrial and Neuromuscular Diseases Laboratory, Instituto de Investigación Sanitaria Hospital '12 de Octubre' ('imas12'), 28041 Madrid, Spain
- Spanish Network for Biomedical Research in Rare Diseases (CIBERER), U723, 28029 Madrid, Spain
| | - Miguel Ángel Martín
- Mitochondrial and Neuromuscular Diseases Laboratory, Instituto de Investigación Sanitaria Hospital '12 de Octubre' ('imas12'), 28041 Madrid, Spain
- Spanish Network for Biomedical Research in Rare Diseases (CIBERER), U723, 28029 Madrid, Spain
- Servicio de Genética, Hospital Universitario "12 de Octubre", 28041 Madrid, Spain
| | - Alejandro Lucia
- Faculty of Sports Sciences, European University of Madrid, 28670 Madrid, Spain
- Spanish Network for Biomedical Research in Fragility and Healthy Aging (CIBERFES), 28029 Madrid, Spain
| | - María Morán
- Mitochondrial and Neuromuscular Diseases Laboratory, Instituto de Investigación Sanitaria Hospital '12 de Octubre' ('imas12'), 28041 Madrid, Spain
- Spanish Network for Biomedical Research in Rare Diseases (CIBERER), U723, 28029 Madrid, Spain
| |
Collapse
|
2
|
Zarante Bahamón AM, Navarro Marroquin S, Suarez-Obando F, Ramón Gómez JL. Recomendaciones de manejo de la hiperamonemia en neonatos. UNIVERSITAS MÉDICA 2023. [DOI: 10.11144/javeriana.umed63-4.rmhn] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
La hiperamonemia se define como el aumento de las concentraciones de amonio en el plasma, de forma aguda o crónica. Frecuentemente, se presenta en diversos tipos de errores innatos del metabolismo, enfermedades que deben diagnosticarse y manejarse de manera inmediata y adecuada, debido a que el retraso en su manejo genera secuelas neurológicas graves y permanentes, así como desenlaces fatales. El objetivo del artículo es aportar herramientas al clínico para la sospecha, el abordaje diagnóstico y el manejo del recién nacido con hiperamonemia primaria, teniendo en cuenta la correlación entre fisiopatología, etiología, aproximación clínica y de laboratorio, así como recomendaciones de manejo farmacológico y no farmacológico.
Collapse
|
3
|
Tahamtan M, Aghaei I, Shabani M, Nazari A, Pooladvand V, Razavinasab M. Peroxisome proliferator-activated receptor-γ doesn't modify altered electrophysiological properties of the CA1 pyramidal neurons in a rat model of hepatic cirrhosis. Metab Brain Dis 2022; 37:2687-2697. [PMID: 35943675 DOI: 10.1007/s11011-022-01057-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Accepted: 07/22/2022] [Indexed: 10/15/2022]
Abstract
Regarding the low quality of life due to the cognitive complications in the patients with hepatic cirrhosis (HC), the goal of this study was to examine the possible neuroprotective effect of pioglitazone (PIO) on the electrophysiological alterations of hippocampus, a major area of cognition, in the experimental model of bile duct ligation (BDL). We used adult male Wistar rats in the present study to perform BDL or sham surgery. Pioglitazone was administered in BDL rats two weeks after the surgery for the next continuous four weeks. The effects of pioglitazone on BDL-induced electrophysiological alterations of the CA1 pyramidal neurons in the hippocampus were evaluated by whole-cell patch clamp recordings. Our findings demonstrated that chronic administration of PIO could not reverse the electrophysiological changes in the CA1 pyramidal neurons of the hippocampus in BDL rats but could improve the hepatic dysfunction.Together, the results of this study suggest that PIO administration cannot counteract altered intrinsic properties of the hippocampal neurons which has been shown recently as an involved mechanism of the cognitive impairments in hepatic encephalopathy (HE).
Collapse
Affiliation(s)
- Mahshid Tahamtan
- Department of Neuroscience, School of Advanced Medical Sciences and Technologies, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Iraj Aghaei
- Neuroscience Research Center, Guilan University of Medical Sciences, Rasht, Iran
| | - Mohammad Shabani
- Neuroscience Research Center, Neuropharmacology Institute, Kerman University of Medical Sciences, 76198-13159, Kerman, Iran.
| | - Abbas Nazari
- Department of Biology, Shiraz Branch, Islamic Azad University, Shiraz, Iran
| | - Vahid Pooladvand
- Biochemical Department, Jiroft University of Medical Sciences, Jiroft, Iran
| | - Moazamehosadat Razavinasab
- Neuroscience Research Center, Neuropharmacology Institute, Kerman University of Medical Sciences, 76198-13159, Kerman, Iran.
| |
Collapse
|
4
|
Sancho-Alonso M, Taoro-Gonzalez L, Cabrera-Pastor A, Felipo V, Teruel-Martí V. Hyperammonemia Alters the Function of AMPA and NMDA Receptors in Hippocampus: Extracellular cGMP Reverses Some of These Alterations. Neurochem Res 2022; 47:2016-2031. [PMID: 35386048 DOI: 10.1007/s11064-022-03588-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 03/17/2022] [Accepted: 03/20/2022] [Indexed: 11/25/2022]
Abstract
Chronic hyperammonemia alters membrane expression of AMPA and NMDA receptors subunits in hippocampus leading to impaired memory and learning. Increasing extracellular cGMP normalizes these alterations. However, it has not been studied whether hyperammonemia alters the function of AMPA and NMDA receptors. The aims of this work were: (1) assess if hyperammonemia alters AMPA and NMDA receptors function; (2) analyze if extracellular cGMP reverses these alterations. A multielectrode array device was used to stimulate Schäffer collaterals and record postsynaptic currents in the CA1 region in hippocampal slices from control and hyperammonemic rats and analyze different features of the excitatory postsynaptic potentials. Hyperammonemia reduces the amplitude and delays appearance of AMPA EPSPs, whereas increases amplitude, hyperpolarization, depolarization and desensitization area of the NMDA EPSPs. These alterations in AMPA and NMDA function are accentuated as the stimulation intensity increases. Adding extracellular cGMP reverses the alteration in amplitude in both, AMPA and NMDA EPSPs. In control slices extracellular cGMP decreases the AMPA and NMDA EPSPs amplitude and delays the response of neurons and the return to the resting potential at all stimulation intensities. In conclusion, hyperammonemia decreases the AMPA response, whereas increases the NMDA response and extracellular cGMP reverses these alterations.
Collapse
Affiliation(s)
- María Sancho-Alonso
- Laboratory of Neurobiology, Centro de Investigación Príncipe Felipe, 46012, Valencia, Spain
| | - Lucas Taoro-Gonzalez
- Laboratory of Neurobiology, Centro de Investigación Príncipe Felipe, 46012, Valencia, Spain
| | - Andrea Cabrera-Pastor
- Laboratory of Neurobiology, Centro de Investigación Príncipe Felipe, 46012, Valencia, Spain.,Fundación Investigación Hospital Clínico, Instituto de Investigación Sanitaria (INCLIVA), 46010, Valencia, Spain
| | - Vicente Felipo
- Laboratory of Neurobiology, Centro de Investigación Príncipe Felipe, 46012, Valencia, Spain.
| | - Vicent Teruel-Martí
- Anatomy and Human Embryology Department, Faculty of Medicine, University of Valencia, 46010, Valencia, Spain
| |
Collapse
|
5
|
Cheon SY, Song J. The Association between Hepatic Encephalopathy and Diabetic Encephalopathy: The Brain-Liver Axis. Int J Mol Sci 2021; 22:ijms22010463. [PMID: 33466498 PMCID: PMC7796499 DOI: 10.3390/ijms22010463] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 01/02/2021] [Accepted: 01/03/2021] [Indexed: 12/13/2022] Open
Abstract
Hepatic encephalopathy (HE) is one of the main consequences of liver disease and is observed in severe liver failure and cirrhosis. Recent studies have provided significant evidence that HE shows several neurological symptoms including depressive mood, cognitive dysfunction, impaired circadian rhythm, and attention deficits as well as motor disturbance. Liver disease is also a risk factor for the development of diabetes mellitus. Diabetic encephalopathy (DE) is characterized by cognitive dysfunction and motor impairment. Recent research investigated the relationship between metabolic changes and the pathogenesis of neurological disease, indicating the importance between metabolic organs and the brain. Given that a diverse number of metabolites and changes in the brain contribute to neurologic dysfunction, HE and DE are emerging types of neurologic disease. Here, we review significant evidence of the association between HE and DE, and summarise the common risk factors. This review may provide promising therapeutic information and help to design a future metabolic organ-related study in relation to HE and DE.
Collapse
Affiliation(s)
- So Yeong Cheon
- Department of Biotechnology, College of Biomedical & Health Science, Konkuk University, Chungju 27478, Korea;
| | - Juhyun Song
- Department of Anatomy, Chonnam National University Medical School, Hwasun 58128, Jeollanam-do, Korea
- Correspondence: ; Tel.: +82-61-379-2706; Fax: +82-61-375-5834
| |
Collapse
|
6
|
Rivera-Mancía S, Tristán-López L, Hernández-Díaz K, Rivera-Espinosa L, Ríos C, Montes S. In vitro inhibition of brain phosphate-activated glutaminase by ammonia and manganese. J Trace Elem Med Biol 2020; 62:126625. [PMID: 32717575 DOI: 10.1016/j.jtemb.2020.126625] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 05/07/2020] [Accepted: 06/11/2020] [Indexed: 12/26/2022]
Abstract
INTRODUCTION As a consequence of the loss of liver function in chronic liver disease, increased levels of ammonia, manganese, and glutamine have been observed in the brain of hepatic encephalopathy patients. OBJECTIVE In the present study, we explored phosphate activated glutaminase (PAG) activity in mitochondrial enriched fractions under treatment with ammonia and manganese. METHODS We dissected out the brain cortex, striatum, and cerebellum of male Wistar rats 250-280 g weight; brain sections were pooled to obtain enriched mitochondrial fractions by differential centrifugation. Aliquots equivalent to 200 μg of protein were incubated with semi-log increasing concentrations of ammonia and/or manganese both as chloride salts (from 0 to 10 000 μM) and glutamine (4 mM) for 30 min. Then, the glutamate produced by the reaction was determined by HPLC coupled with fluorescence detection. RESULTS AND DISCUSSION Both manganese and ammonia inhibited PAG in a concentration-dependent manner. Non-linear modeling was used to determine IC50 and IC20 for ammonia (120 μM) and manganese (2 mM). We found that PAG activity under the combination of IC20 of ammonia and manganese was equivalent to the sum of the effects of both substances, being PAG inhibition more pronounced in mitochondrial fractions from cerebellum. The PAG inhibition observed here could potentially explain a pathway for glutamine accumulation, by means of the inhibition of PAG activity as a consequence of increased concentrations of manganese and ammonia in the brain under liver damage conditions.
Collapse
Affiliation(s)
- Susana Rivera-Mancía
- CONACYT- National Institute of Cardiology "Ignacio Chávez", Juan Badiano 1, Sección XVI, Tlalpan, CDMX, 14080, Mexico
| | - Luis Tristán-López
- Neurochemistry Department, National Institute of Neurology and Neurosurgery "Manuel Velasco Suárez", Insurgentes sur 3877, La Fama, Tlalpan, CDMX, 14269, Mexico
| | - Karen Hernández-Díaz
- Neurochemistry Department, National Institute of Neurology and Neurosurgery "Manuel Velasco Suárez", Insurgentes sur 3877, La Fama, Tlalpan, CDMX, 14269, Mexico
| | - Liliana Rivera-Espinosa
- Pharmacology Department, National Institute of Pediatrics, Iman Avenue 1, Insurgentes Cuicuilco, Coyoacán, CDMX, 04530, Mexico
| | - Camilo Ríos
- Neurochemistry Department, National Institute of Neurology and Neurosurgery "Manuel Velasco Suárez", Insurgentes sur 3877, La Fama, Tlalpan, CDMX, 14269, Mexico
| | - Sergio Montes
- Neurochemistry Department, National Institute of Neurology and Neurosurgery "Manuel Velasco Suárez", Insurgentes sur 3877, La Fama, Tlalpan, CDMX, 14269, Mexico.
| |
Collapse
|
7
|
Higarza SG, Arboleya S, Gueimonde M, Gómez-Lázaro E, Arias JL, Arias N. Neurobehavioral dysfunction in non-alcoholic steatohepatitis is associated with hyperammonemia, gut dysbiosis, and metabolic and functional brain regional deficits. PLoS One 2019; 14:e0223019. [PMID: 31539420 PMCID: PMC6754158 DOI: 10.1371/journal.pone.0223019] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 09/11/2019] [Indexed: 12/11/2022] Open
Abstract
Non-alcoholic steatohepatitis (NASH) is one of the most prevalent diseases worldwide. While it has been suggested to cause nervous impairment, its neurophysiological basis remains unknown. Therefore, the aim of this study is to unravel the effects of NASH, through the interrelationship of liver, gut microbiota, and nervous system, on the brain and human behavior. To this end, 40 Sprague-Dawley rats were divided into a control group that received normal chow and a NASH group that received a high-fat, high-cholesterol diet. Our results show that 14 weeks of the high-fat, high-cholesterol diet induced clinical conditions such as NASH, including steatosis and increased levels of ammonia. Rats in the NASH group also demonstrated evidence of gut dysbiosis and decreased levels of short-chain fatty acids in the gut. This may explain the deficits in cognitive ability observed in the NASH group, including their depressive-like behavior and short-term memory impairment characterized in part by deficits in social recognition and prefrontal cortex-dependent spatial working memory. We also reported the impact of this NASH-like condition on metabolic and functional processes. Brain tissue demonstrated lower levels of metabolic brain activity in the prefrontal cortex, thalamus, hippocampus, amygdala, and mammillary bodies, accompanied by a decrease in dopamine levels in the prefrontal cortex and cerebellum and a decrease in noradrenalin in the striatum. In this article, we emphasize the important role of ammonia and gut-derived bacterial toxins in liver-gut-brain neurodegeneration and discuss the metabolic and functional brain regional deficits and behavioral impairments in NASH.
Collapse
Affiliation(s)
- Sara G. Higarza
- Institute of Neurosciences of the Principality of Asturias (INEUROPA), Asturias, Spain
- Laboratory of Neuroscience, Department of Psychology, University of Oviedo, Oviedo, Asturias, Spain
| | - Silvia Arboleya
- Department of Microbiology and Biochemistry of Dairy Products, Institute of Dairy Products of the Principality of Asturias (IPLA-CSIC), Asturias, Spain
| | - Miguel Gueimonde
- Department of Microbiology and Biochemistry of Dairy Products, Institute of Dairy Products of the Principality of Asturias (IPLA-CSIC), Asturias, Spain
| | - Eneritz Gómez-Lázaro
- Department of Basic Psychological Processes and their Development, Basque Country University, San Sebastián, Basque Country, Spain
| | - Jorge L. Arias
- Institute of Neurosciences of the Principality of Asturias (INEUROPA), Asturias, Spain
- Laboratory of Neuroscience, Department of Psychology, University of Oviedo, Oviedo, Asturias, Spain
| | - Natalia Arias
- Institute of Neurosciences of the Principality of Asturias (INEUROPA), Asturias, Spain
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, England, United Kingdom
| |
Collapse
|
8
|
Cittolin-Santos G, Guazzelli P, Nonose Y, Almeida R, Fontella F, Pasquetti M, Ferreira-Lima F, Lazzaroto G, Berlezi R, Osvaldt A, Calcagnotto M, de Assis A, Souza D. Behavioral, Neurochemical and Brain Oscillation Abnormalities in an Experimental Model of Acute Liver Failure. Neuroscience 2019; 401:117-129. [DOI: 10.1016/j.neuroscience.2018.12.032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Revised: 12/14/2018] [Accepted: 12/18/2018] [Indexed: 01/17/2023]
|
9
|
Cabrera-Pastor A, Arenas YM, Taoro-Gonzalez L, Montoliu C, Felipo V. Chronic hyperammonemia alters extracellular glutamate, glutamine and GABA and membrane expression of their transporters in rat cerebellum. Modulation by extracellular cGMP. Neuropharmacology 2019; 161:107496. [PMID: 30641078 DOI: 10.1016/j.neuropharm.2019.01.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 12/15/2018] [Accepted: 01/10/2019] [Indexed: 12/14/2022]
Abstract
Trafficking of glutamate, glutamine and GABA between astrocytes and neurons is essential to maintain proper neurotransmission. Chronic hyperammonemia alters neurotransmission and cognitive function. The aims of this work were to analyze in cerebellum of rats the effects of chronic hyperammonemia on: a) extracellular glutamate, glutamine and GABA concentrations; b) membrane expression of glutamate, glutamine and GABA transporters; c) how they are modulated by extracellular cGMP. Hyperammonemic rats show increased levels of extracellular glutamate, glutamine, GABA and citrulline in cerebellum in vivo. Hyperammonemic rats show: a) increased membrane expression of the astrocytic glutamine transporter SNAT3 and reduced membrane expression of the neuronal transporter SNAT1; b) reduced membrane expression of the neuronal GABA transporter GAT1 and increased membrane expression of the astrocytic GAT3 transporter; c) reduced membrane expression of the astrocytic glutamate transporters GLAST and GLT-1 and of the neuronal transporter EAAC1. Increasing extracellular cGMP normalizes membrane expression of SNAT3, GAT3, GAT1 and GLAST and extracellular glutamate, glutamine, GABA and citrulline hyperammonemic rats. Extracellular cGMP also modulates membrane expression of most transporters in control rats, reducing membrane expression of SNAT1, GLT-1 and EAAC1 and increasing that of GAT1 and GAT3. Modulation of SNAT3, SNAT1, GLT-1 and EAAC1 by extracellular cGMP would be mediated by inhibition of glycine receptors. These data suggest that, in pathological situations such as hyperammonemia, hepatic encephalopathy or Alzheimer's disease, reduced levels of extracellular cGMP contribute to alterations in membrane expression of glutamine, glutamate and GABA transporters, in the extracellular levels of glutamine, glutamate and GABA and in neurotransmission. This article is part of the issue entitled 'Special Issue on Neurotransmitter Transporters'.
Collapse
Affiliation(s)
- Andrea Cabrera-Pastor
- Laboratory of Neurobiology, Centro de Investigación Principe Felipe, Valencia, Spain; Fundacion Investigacion Hospital Clinico Valencia, Instituto de Investigacion Sanitaria INCLIVA, Valencia, Spain
| | - Yaiza M Arenas
- Laboratory of Neurobiology, Centro de Investigación Principe Felipe, Valencia, Spain
| | - Lucas Taoro-Gonzalez
- Laboratory of Neurobiology, Centro de Investigación Principe Felipe, Valencia, Spain
| | - Carmina Montoliu
- Fundacion Investigacion Hospital Clinico Valencia, Instituto de Investigacion Sanitaria INCLIVA, Valencia, Spain
| | - Vicente Felipo
- Laboratory of Neurobiology, Centro de Investigación Principe Felipe, Valencia, Spain.
| |
Collapse
|
10
|
Extracellular cGMP Reverses Altered Membrane Expression of AMPA Receptors in Hippocampus of Hyperammonemic Rats: Underlying Mechanisms. Mol Neurobiol 2018; 56:4428-4439. [PMID: 30328550 DOI: 10.1007/s12035-018-1387-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 10/09/2018] [Indexed: 01/06/2023]
Abstract
Chronic hyperammonemia impairs spatial memory by altering membrane expression of GluA1 and GluA2 subunits of AMPA receptors in hippocampus. Intracerebral administration of extracellular cGMP to hyperammonemic rats restores spatial memory and membrane expression of AMPA receptors. The underlying molecular mechanisms remain unknown and cannot be analyzed in vivo. The aims of the present work were to (1) assess whether extracellular cGMP reverses the alterations in membrane expression of GluA1 and GluA2 in hippocampus of hyperammonemic rats ex vivo and (2) identify the underlying mechanisms. To reach these aims, we used freshly isolated hippocampal slices from control and hyperammonemic rats and treated them ex vivo with extracellular cGMP. Extracellular cGMP normalizes membrane expression of GluA2 restoring its phosphorylation in Ser880 because it restores PKCζ activation by Thr560 auto-phosphorylation, which is a consequence of normalization by extracellular cGMP of phosphorylation and activity of p38 which was increased in hyperammonemic rats. Normalization of p38 is a consequence of normalization of membrane expression of the GluN2B subunit of NMDA receptor, mediated by a reduction in its phosphorylation in Tyr1472 due to reduction of Src activation, which was over-activated in hyperammonemic rats. Extracellular cGMP also restores membrane expression of GluA1 increasing its phosphorylation at Ser831 because it restores CaMKII membrane association and phosphorylation in Thr286. All these effects of extracellular cGMP are due to a reduction of hippocampal IL-1β levels in hyperammonemic rats, which reduces IL-1 receptor-mediated Src over-activation. Reduction in IL-1β levels is due to the reduction of microglia activation in hippocampus of hyperammonemic rats.
Collapse
|
11
|
Bona L, van Staaveren N, Pokharel BB, van Krimpen M, Harlander-Matauschek A. The Effect of Low Protein Energy-Rich Diets on Plasma Hepatic Markers, Hepatic Damage, and Discrimination Reversal Learning in Young Female Chicks. Front Vet Sci 2018; 5:107. [PMID: 30177972 PMCID: PMC6110198 DOI: 10.3389/fvets.2018.00107] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 05/01/2018] [Indexed: 01/09/2023] Open
Abstract
Consumption of low protein energy-rich (LPER) diets increases susceptibility to metabolic disease in mammals, such as hepatic damage, and can have an adverse effect on cognition. However, the effects of these diets on both physical and mental welfare have not been investigated in domestic meat chickens. Female chicks received a low protein energy-rich or a standard control diet from 21 to 51 days of age. The effects of these dietary manipulations on plasma hepatic markers for liver damage, liver necropsy, and learning a visual discrimination reversal task were assessed. Birds given access to LPER diets weighed less than chicks that had access to the control diets. All chicks had post-mortem signs of hepatic hemorrhage/increased liver color scores and aspartate aminotransferase (AST) levels above 230 U/L indicative of hepatic damage in birds. The LPER diet had no impact on the performance of female chicks when learning to distinguish colors in a reversal visual discrimination task. The present study suggests that liver damage does not become worse when feeding LPER or impact visual reversal learning in female meat-type chickens. However, the high incidence of liver cell damage/liver hemorrhage, and “abnormal” AST activities are of concern in female broiler chicks across both diets, and suggests that the health of modern meat-type genotypes needs to be improved.
Collapse
Affiliation(s)
- Laura Bona
- Department of Animal Biosciences, University of Guelph, Guelph, ON, Canada
| | | | | | | | | |
Collapse
|
12
|
Williams TA, Bonham LA, Bernier NJ. High environmental ammonia exposure has developmental-stage specific and long-term consequences on the cortisol stress response in zebrafish. Gen Comp Endocrinol 2017; 254:97-106. [PMID: 28958860 DOI: 10.1016/j.ygcen.2017.09.024] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 09/22/2017] [Accepted: 09/24/2017] [Indexed: 12/15/2022]
Abstract
The capacity for early life environmental stressors to induce programming effects on the endocrine stress response in fish is largely unknown. In this study we determined the effects of high environmental ammonia (HEA) exposure on the stress response in larval zebrafish, assessed the tolerance of embryonic and larval stages to HEA, and evaluated whether early life HEA exposure has long-term consequences on the cortisol response to a novel stressor. Exposure to 500-2000μM NH4Cl for 16h did not affect the gene expression of corticotropin-releasing factor (CRF) system components in 1day post-fertilization (dpf) embryos, but differentially increased crfa, crfb and CRF binding protein (crfbp) expression and stimulated both dose- and time-dependent increases in the whole body cortisol of 5dpf larvae. Pre-acclimation to HEA at 1dpf did not affect the cortisol response to a subsequent NH4Cl exposure at 5dpf. In contrast, pre-acclimation to HEA at 5dpf caused a small but significant reduction in the cortisol response to a second NH4Cl exposure at 10dpf. While continuous exposure to 500-2000μM NH4Cl between 0 and 5dpf had a modest effect on mean survival time, exposure to 400-1000μM NH4Cl between 10 and 14dpf decreased mean survival time in a dose-dependent manner. Moreover, pre-acclimation to HEA at 5dpf significantly decreased the risk of mortality to continuous NH4Cl exposure between 10 and 14dpf. Finally, while HEA at 1dpf did not affect the cortisol stress response to a novel vortex stressor at 5dpf, the same HEA treatment at 5dpf abolished vortex stressor-induced increases in whole body cortisol at 10 and 60dpf. Together these results show that the impact of HEA on the cortisol stress response during development is life-stage specific and closely linked to ammonia tolerance. Further, we demonstrate that HEA exposure at the larval stage can have persistent effects on the capacity to respond to stressors in later life.
Collapse
Affiliation(s)
- Tegan A Williams
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Luke A Bonham
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Nicholas J Bernier
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada.
| |
Collapse
|
13
|
Cabrera-Pastor A, Taoro-González L, López-Merino E, Celma F, Llansola M, Felipo V. Chronic hyperammonemia alters in opposite ways membrane expression of GluA1 and GluA2 AMPA receptor subunits in cerebellum. Molecular mechanisms involved. Biochim Biophys Acta Mol Basis Dis 2017; 1864:286-295. [PMID: 29107806 DOI: 10.1016/j.bbadis.2017.10.031] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2017] [Revised: 10/14/2017] [Accepted: 10/26/2017] [Indexed: 02/07/2023]
Abstract
Hyperammonemia contributes to altered neurotransmission and cognition in patients with hepatic encephalopathy. Hyperammonemia in rats affects differently high- and low-affinity AMPA receptors (AMPARs) in cerebellum. We hypothesized that hyperammonemia would alter differently membrane expression of AMPARs GluA1 and GluA2 subunits by altering its phosphorylation. This work aims were: 1) assess if hyperammonemia alters GluA1 and GluA2 subunits membrane expression in cerebellum and 2) analyze the underlying mechanisms. Hyperammonemia reduces membrane expression of GluA2 and enhances membrane expression of GluA1 in vivo. We show that changes in GluA2 and GluA1 membrane expression in hyperammonemia would be due to enhanced NMDA receptors activation which reduces cGMP levels and phosphodiesterase 2 (PDE2) activity, resulting in increased cAMP levels. This leads to increased protein kinase A (PKA) activity which activates phospholipase C (PLC) and protein kinase C (PKC) thus increasing phosphorylation of GluA2 in Ser880, which reduces GluA2 membrane expression, and phosphorylation of GluA1 in Ser831, which increases GluA1 membrane expression. Blocking NMDA receptors or inhibiting PKA, PLC or PKC normalizes GluA2 and GluA1 phosphorylation and membrane expression in hyperammonemic rats. Altered GluA2 and GluA1 membrane expression would alter signal transduction which may contribute to cognitive and motor alterations in hyperammonemia and hepatic encephalopathy.
Collapse
Affiliation(s)
- Andrea Cabrera-Pastor
- Laboratory of Neurobiology, Centro de Investigacion Príncipe Felipe, 46012, Valencia, Spain
| | - Lucas Taoro-González
- Laboratory of Neurobiology, Centro de Investigacion Príncipe Felipe, 46012, Valencia, Spain
| | - Esperanza López-Merino
- Laboratory of Neurobiology, Centro de Investigacion Príncipe Felipe, 46012, Valencia, Spain
| | - Ferran Celma
- Laboratory of Neurobiology, Centro de Investigacion Príncipe Felipe, 46012, Valencia, Spain
| | - Marta Llansola
- Laboratory of Neurobiology, Centro de Investigacion Príncipe Felipe, 46012, Valencia, Spain
| | - Vicente Felipo
- Laboratory of Neurobiology, Centro de Investigacion Príncipe Felipe, 46012, Valencia, Spain.
| |
Collapse
|
14
|
Tahamtan M, Aghaei I, Pooladvand V, Sheibani V, Khaksari M, Shabani M. Characterization of the CA1 pyramidal neurons in rat model of hepatic cirrhosis: insights into their electrophysiological properties. Metab Brain Dis 2017; 32:881-889. [PMID: 28265840 DOI: 10.1007/s11011-017-9966-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 01/31/2017] [Indexed: 12/23/2022]
Abstract
Although the key contributors of altering neurological function in hepatic encephalopathy are relatively well known, the electrophysiological mechanism of CA1 damage, a key vulnerable area during hyperammonemia, have not yet been defined. Therefore, here we focus on the electrophysiological mechanisms of cognitive impairments following bile duct ligation (BDL). We performed patch-clamp recordings from the CA1 pyramidal neurons in hippocampus of male Wistar rats, which underwent sham or BDL surgery. A striking electrophysiological change of hippocampal neurons in experimental model of BDL was observed in the present study. Spontaneous firing frequency and rate of action potential (AP) rebound was decreased and afterhyperpolarization amplitude (AHP) was increased significantly in hippocampal cells of BDL animals compared to sham group. Together, the results suggest that altered intrinsic properties of the hippocampal neurons may contribute to the cognitive abnormalities during hepatic encephalopathy (HE), highlighting the electrophysiological mechanisms for providing new treatments against HE.
Collapse
Affiliation(s)
- Mahshid Tahamtan
- Neuroscience Research Center, Neuropharmacology Institute, Kerman University of Medical Sciences, Kerman, 76198-13159, Iran
| | - Iraj Aghaei
- Social Determinants of Health Research Center, Guilan University of Medical Sciences, Rasht, Iran
| | - Vahid Pooladvand
- Biochemical Department, Jiroft University of Medical Sciences, Kerman, Iran
| | - Vahid Sheibani
- Neuroscience Research Center, Neuropharmacology Institute, Kerman University of Medical Sciences, Kerman, 76198-13159, Iran
| | - Mohammad Khaksari
- Endocrinology and Metabolism Research Center, Institute of Basic and Clinical Physiology Sciences, Kerman University of Medical Sciences, Kerman, Iran
| | - Mohammad Shabani
- Neuroscience Research Center, Neuropharmacology Institute, Kerman University of Medical Sciences, Kerman, 76198-13159, Iran.
| |
Collapse
|
15
|
Glutamine triggers long-lasting increase in striatal network activity in vitro. Exp Neurol 2017; 290:41-52. [DOI: 10.1016/j.expneurol.2017.01.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 12/05/2016] [Accepted: 01/04/2017] [Indexed: 01/04/2023]
|
16
|
Aghaei I, Saeedi Saravi SS, Ghotbi Ravandi S, Nozari M, Roudbari A, Dalili A, Shabani M, Dehpour AR. Evaluation of prepulse inhibition and memory impairments at early stage of cirrhosis may be considered as a diagnostic index for minimal hepatic encephalopathy. Physiol Behav 2017; 173:87-94. [PMID: 28119160 DOI: 10.1016/j.physbeh.2017.01.033] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Revised: 10/22/2016] [Accepted: 01/19/2017] [Indexed: 12/12/2022]
Abstract
Minimal hepatic encephalopathy (MHE), which represents the early stage of this condition, is not clinically apparent and is prevalent in up to 80% of patients. The poor outcomes of MHE encouraged us to identify more simple methods for early diagnosis of MHE. To this purpose, we evaluated the contemporary manifestations of motor, cognitive and sensorimotor gaiting deficits following bile duct-ligation (BDL). Male Wistar rats were undergone BDL to induce cirrhosis and locomotor, spatial learning and memory and sensorimotor gating were assessed 2, 3, and 4weeks after the operation by rotarod, Morris water-maze and prepulse inhibition (PPI) tests. PPI was examined 6weeks after BDL until appearance of hepatic encephalopathy. Results showed that although PPI was significantly enhanced in the 6-week BDL animals, locomotor activity reduced in 4-week BDL rats compared to the BDL rats after a 2-week period. The total distance travelled and swimming time to reach the platform increased in the 4-week BDL rats and, in contrast, the percentage of time spent and space travelled in correct quadrant decreased. Moreover, memory index decreased in the 3-week BDL group compared to sham-operated group. It was observed an increase in global PPI in 3- and 4-week BDL animals in comparison with either 2-week BDL or sham-operated rats. Consequently, it is indicated that BDL animals manifest spatial learning and memory deficits and PPI disruption in early stage of HE and evaluation of these factors can be considered as indices for simple and early diagnosis of MHE.
Collapse
Affiliation(s)
- Iraj Aghaei
- Social Determinants of Health Research Center, Guilan University of Medical Sciences, Rasht, Iran; Neuroscience Research Center, Neuropharmacology Institute, Kerman University of Medical Sciences, Kerman, Iran
| | - Seyed Soheil Saeedi Saravi
- Department of Toxicology-Pharmacology, Faculty of Pharmacy, Guilan University of Medical Sciences, Rasht, Iran; Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran; Experimental Medicine Research Center, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Samaneh Ghotbi Ravandi
- Neuroscience Research Center, Neuropharmacology Institute, Kerman University of Medical Sciences, Kerman, Iran
| | - Masoumeh Nozari
- Department of Physiology, Afzalipour School of Medicine, Kerman University of Medical Sciences, Kerman, Iran
| | - Ali Roudbari
- Neuroscience Research Center, Department of Neurology, Poursina Hospital, School of Medicine, Guilan University of Medical sciences, Rasht, Iran
| | - Afshin Dalili
- Razi Hospital, Guilan University of Medical Sciences, Rasht, Iran
| | - Mohammad Shabani
- Neuroscience Research Center, Neuropharmacology Institute, Kerman University of Medical Sciences, Kerman, Iran.
| | - Ahmad Reza Dehpour
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran; Experimental Medicine Research Center, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
| |
Collapse
|
17
|
Acute Hyperammonemia Induces NMDA-Mediated Hypophosphorylation of Intermediate Filaments Through PP1 and PP2B in Cerebral Cortex of Young Rats. Neurotox Res 2016; 30:138-49. [PMID: 26936604 DOI: 10.1007/s12640-016-9607-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 01/20/2016] [Accepted: 02/10/2016] [Indexed: 11/27/2022]
Abstract
In the present work, we studied the effects of toxic ammonia levels on the cytoskeleton of neural cells, with emphasis in the homeostasis of the phosphorylating system associated with the intermediate filaments (IFs). We used in vivo and in vitro models of acute hyperammonemia in 10- and 21-day-old rats. In the in vivo model, animals were intraperitoneally injected with ammonium acetate (7 mmol/Kg), and the phosphorylation level of the cytoskeletal proteins was analyzed in the cerebral cortex and hippocampus 30 and 60 min after injection. The injected ammonia altered the IF phosphorylation of astrocytes (GFAP and vimentin) and neurons (neurofilament subunits of low, middle, and high molecular weight, respectively: NFL, NFM, and NFH) from cerebral cortex of 21-day-old rats. This was a transitory effect observed 30 min after injection, recovering 30 min afterward. Phosphorylation was not altered in the cerebral cortex of 10-day-old pups. The homeostasis of hippocampal IFs was preserved at the studied ages and times. In the in vitro model, cortical slices of 10- and 21-day-old rats were incubated with 0.5, 1, or 5 mM NH4Cl, and the phosphorylation level of the IF proteins was analyzed after 30 min. The IF phosphorylation was not altered in cortical slices of 10-day-old rats; however, in cortical slices of 21-day-old pups, 5 mM NH4Cl induced hypophosphorylation of GFAP and vimentin, preserving neurofilament phosphorylation levels. Hypophosphorylation was mediated by the protein phosphatases 1 (PP1) and 2B (PP2B), and this event was associated with Ca(2+) influx via N-methyl-D-aspartate (NMDA) glutamate receptors. The aim of this study is to show that acute ammonia toxicity targets the phosphorylating system of IFs in the cerebral cortex of rats in a developmentally regulated manner, and NMDA-mediated Ca(2+) signaling plays a central role in this mechanism. We propose that the disruption of cytoskeletal homeostasis could be an endpoint of the acute hyperammonemia in the developing brain. We believe that these results contribute for better understanding the molecular basis of the ammonia toxicity in brain.
Collapse
|
18
|
Aghaei I, Hajali V, Dehpour A, Haghani M, Sheibani V, Shabani M. Alterations in the intrinsic electrophysiological properties of Purkinje neurons in a rat model of hepatic encephalopathy: Relative preventing effect of PPARγ agonist. Brain Res Bull 2016; 121:16-25. [DOI: 10.1016/j.brainresbull.2015.12.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 12/08/2015] [Accepted: 12/10/2015] [Indexed: 12/17/2022]
|
19
|
Ahmadi S, Poureidi M, Rostamzadeh J. Hepatic encephalopathy induces site-specific changes in gene expression of GluN1 subunit of NMDA receptor in rat brain. Metab Brain Dis 2015; 30:1035-41. [PMID: 25896221 DOI: 10.1007/s11011-015-9669-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Accepted: 04/01/2015] [Indexed: 01/08/2023]
Abstract
We investigate changes in gene expression of GluN1 subunit of N-Methyl-D-Aspartate (NMDA) receptor in the prefrontal cortex (PFC), hippocampus and striatum in a rat model of hepatic encephalopathy (HE). We used male Wistar rats in which HE was induced after a common bile duct ligation (BDL). The animals were divided into three sets, and each set included three groups of control, sham operated and BDL. In the first set of animals, blood samples collected for biochemical analysis on day 21 of BDL. In the second set, changes in nociception threshold was assessed on day 21 of BDL using a hotplate test. In the third set, whole brain extracted, and the PFC, the hippocampus and the striatum in each rat were immediately dissected. We used a semi-quantitative RT-PCR method for evaluating the GluN1 gene expression. The biochemical analyses showed that plasma levels of ammonia and bilirubin in BDL rats were significantly increased compared to the sham control group on day 21 of BDL (P < 0.01). Nociception threshold was also increased in rats with BDL compared to sham group (P < 0.001). The results revealed that the GluN1 gene expression at mRNA levels in BDL group was decreased by 19 % in the PFC (P < 0.05) but increased by 82 % in the hippocampus (P < 0.01) compared to the sham control group; however, no significant change was observed in the striatum. It can be concluded that HE affects the GluN1 gene expression in rat brain with a site-specific pattern, and the PFC and hippocampus are more sensitive areas than striatum.
Collapse
Affiliation(s)
- Shamseddin Ahmadi
- Department of Biological Science and Biotechnology, Faculty of Science, University of Kurdistan, P.O. Box 416, Sanandaj, Iran,
| | | | | |
Collapse
|
20
|
Ott P, Vilstrup H. Cerebral effects of ammonia in liver disease: current hypotheses. Metab Brain Dis 2014; 29:901-11. [PMID: 24488230 DOI: 10.1007/s11011-014-9494-7] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2013] [Accepted: 01/21/2014] [Indexed: 12/15/2022]
Abstract
Hyperammonemia is necessary for development of the cerebral complications to liver disease including hepatic encephalopathy and cerebral edema but the mechanisms are unclear. Ammonia is taken up by the brain in proportion to its arterial concentration. The flux into the brain is most likely by both diffusion of NH3 and mediated transport of NH4 (+) . Astrocytic detoxification of ammonia involves formation of glutamine at concentrations high enough to produce cellular edema, but compensatory mechanisms reduce this effect. Glutamine can be taken up by astrocytic mitochondria and initiate the mitochondrial permeability transition but the clinical relevance is uncertain. Elevated astrocytic glutamine interferes with neurotransmission. Thus, animal studies show enhanced glutamatergic neurotransmission via the NMDA receptor which may be related to the acute cerebral complications to liver failure, while impairment of the NMDA activated glutamate-NO-cGMP pathway could relate to the behavioural changes seen in hepatic encephalopathy. Elevated glutamine also increases GABA-ergic tone, an effect which is aggravated by mitochondrial production of neurosteroids; this may relate to decreased neurotransmission and precipitation of encephalopathy by GABA targeting drugs. Hyperammonemia may compromise cerebral energy metabolism as elevated cerebral lactate is generally reported. Hypoxia is unlikely since cerebral oxygen:glucose utilisation and lactate:pyruvate ratio are both normal in clinical studies. Ammonia inhibits α-ketoglutaratedehydrogenase in isolated mitochondria, but the clinical relevance is dubious due to the observed normal cerebral oxygen:glucose utilization. Recent studies suggest that ammonia stimulates glycolysis in excess of TCA cycle activity, a hypothesis that may warrant further testing, in being in accordance with the limited clinical observations.
Collapse
Affiliation(s)
- Peter Ott
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, 8000C, Aarhus, Denmark,
| | | |
Collapse
|
21
|
Dienel GA, Cruz NF. Reduced clearance of proteins labeled with diisopropylfluorophosphate in portacaval-shunted rats. Metab Brain Dis 2014; 29:1041-52. [PMID: 24154686 PMCID: PMC4000281 DOI: 10.1007/s11011-013-9442-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Accepted: 10/16/2013] [Indexed: 10/26/2022]
Abstract
Portacaval shunting is a model for hepatic encephalopathy that causes chronic hyperammonemia, disruption of metabolic, signaling, and neurotransmitter systems, and progressive morphological changes. Exposure of cultured cells to ammonia raises intralysosomal pH and inhibits proteolysis, and the present study tested the hypothesis that proteolytic capacity is diminished in portacaval-shunted rats. Proteins were labeled in vivo with tracer doses of diisopropylfluorophosphate (DFP) and clearance of label was assayed. This approach labeled proteins independent of protein synthesis, which is reported to be altered in shunted rats, and avoided complications arising from re-utilization of labeled amino acids that causes underestimation of degradation rate. Characterization of DFP labeling showed that protein labeling was fast, about 50% of the label was released during a 24 h interval, labeling by DFP metabolites was negligible, inhibition of brain acetylcholinesterase was not detectable, and labeling by [(3)H]- and [(14)C]DFP was equivalent. To assay degradative capacity, proteins were first labeled with [(3)H]DFP, followed by labeling with [(14)C]DFP that was given 24 or 72 h later. The (3)H/(14)C ratio in each animal was used as a relative measure of removal of (3)H-labeled proteins. (3)H/(14)C ratios were generally significantly higher in portacaval-shunted rats than in controls, consistent with reduced proteolytic capacity. Assays of amino acid incorporation into brain protein generally replicated literature reports, supporting the conclusion that protein synthesis unlikely to be markedly inhibited and amino acid recycling influences calculated protein synthesis rates in shunted rats. Therapeutic strategies to reduce ammonia level would help normalize lysosomal functions and protein and lipid turnover.
Collapse
Affiliation(s)
- Gerald A Dienel
- Department of Neurology, University of Arkansas for Medical Sciences, Slot 500, 4301 W. Markham St., Shorey Bldg., Room 715, Little Rock, AR, 72205, USA,
| | | |
Collapse
|
22
|
Jayakumar AR, Tong XY, Curtis KM, Ruiz-Cordero R, Shamaladevi N, Abuzamel M, Johnstone J, Gaidosh G, Rama Rao KV, Norenberg MD. Decreased astrocytic thrombospondin-1 secretion after chronic ammonia treatment reduces the level of synaptic proteins: in vitro and in vivo studies. J Neurochem 2014; 131:333-47. [PMID: 25040426 PMCID: PMC4364553 DOI: 10.1111/jnc.12810] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2014] [Revised: 06/16/2014] [Accepted: 06/22/2014] [Indexed: 12/23/2022]
Abstract
Chronic hepatic encephalopathy (CHE) is a major complication in patients with severe liver disease. Elevated blood and brain ammonia levels have been implicated in its pathogenesis, and astrocytes are the principal neural cells involved in this disorder. Since defective synthesis and release of astrocytic factors have been shown to impair synaptic integrity in other neurological conditions, we examined whether thrombospondin-1 (TSP-1), an astrocytic factor involved in the maintenance of synaptic integrity, is also altered in CHE. Cultured astrocytes were exposed to ammonia (NH₄Cl, 0.5-2.5 mM) for 1-10 days, and TSP-1 content was measured in cell extracts and culture media. Astrocytes exposed to ammonia exhibited a reduction in intra- and extracellular TSP-1 levels. Exposure of cultured neurons to conditioned media from ammonia-treated astrocytes showed a decrease in synaptophysin, PSD95, and synaptotagmin levels. Conditioned media from TSP-1 over-expressing astrocytes that were treated with ammonia, when added to cultured neurons, reversed the decline in synaptic proteins. Recombinant TSP-1 similarly reversed the decrease in synaptic proteins. Metformin, an agent known to increase TSP-1 synthesis in other cell types, also reversed the ammonia-induced TSP-1 reduction. Likewise, we found a significant decline in TSP-1 level in cortical astrocytes, as well as a reduction in synaptophysin content in vivo in a rat model of CHE. These findings suggest that TSP-1 may represent an important therapeutic target for CHE. Defective release of astrocytic factors may impair synaptic integrity in chronic hepatic encephalopathy. We found a reduction in the release of the astrocytic matricellular proteins thrombospondin-1 (TSP-1) in ammonia-treated astrocytes; such reduction was associated with a decrease in synaptic proteins caused by conditioned media from ammonia-treated astrocytes. Exposure of neurons to CM from ammonia-treated astrocytes, in which TSP-1 is over-expressed, reversed (by approx 75%) the reduction in synaptic proteins. NF-kB = nuclear factor kappa B; PSD95 = post-synaptic density protein 95; ONS = oxidative/nitrative stress.
Collapse
Affiliation(s)
- Arumugam R Jayakumar
- Laboratory of Neuropathology, Veterans Affairs Medical Center, Miami, Florida, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Torres-Vega MA, Vargas-Jerónimo RY, Montiel-Martínez AG, Muñoz-Fuentes RM, Zamorano-Carrillo A, Pastor AR, Palomares LA. Delivery of glutamine synthetase gene by baculovirus vectors: a proof of concept for the treatment of acute hyperammonemia. Gene Ther 2014; 22:58-64. [DOI: 10.1038/gt.2014.89] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Revised: 07/26/2014] [Accepted: 09/02/2014] [Indexed: 12/27/2022]
|
24
|
Díaz-Herrero MM, del Campo JA, Carbonero-Aguilar P, Vega-Pérez JM, Iglesias-Guerra F, Periñán I, Miñano FJ, Bautista J, Romero-Gómez M. THDP17 decreases ammonia production through glutaminase inhibition. A new drug for hepatic encephalopathy therapy. PLoS One 2014; 9:e109787. [PMID: 25329718 PMCID: PMC4201470 DOI: 10.1371/journal.pone.0109787] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 09/03/2014] [Indexed: 11/29/2022] Open
Abstract
Ammonia production is implicated in the pathogenesis of hepatic encephalopathy (HE), being intestinal glutaminase activity the main source for ammonia. Management of ammonia formation can be effective in HE treatment by lowering intestinal ammonia production. The use of glutaminase inhibitors represents one way to achieve this goal. In this work, we have performed a search for specific inhibitors that could decrease glutaminase activity by screening two different groups of compounds: i) a group integrated by a diverse, highly pure small molecule compounds derived from thiourea ranging from 200 to 800 Daltons; and ii) a group integrated by commonly use compounds in the treatment of HE. Results shown that THDP-17 (10 µM), a thiourea derivate product, could inhibit the intestinal glutaminase activity (57.4±6.7%). Inhibitory effect was tissue dependent, ranging from 40±5.5% to 80±7.8% in an uncompetitive manner, showing Vmax and Km values of 384.62 µmol min−1, 13.62 mM with THDP-17 10 µM, respectively. This compound also decreased the glutaminase activity in Caco-2 cell cultures, showing a reduction of ammonia and glutamate production, compared to control cultures. Therefore, the THDP-17 compound could be a good candidate for HE management, by lowering ammonia production.
Collapse
Affiliation(s)
- M. Mar Díaz-Herrero
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, Sevilla, Spain
| | - José A. del Campo
- Unidad de Gestión Clínica de Enfermedades Digestivas & Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Hospital Universitario de Valme, Sevilla, Spain
| | - Pilar Carbonero-Aguilar
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, Sevilla, Spain
| | - José M. Vega-Pérez
- Departamento de Química Orgánica y Química Farmacéutica, Facultad de Farmacia, Universidad de Sevilla, Sevilla, Spain
| | - Fernando Iglesias-Guerra
- Departamento de Química Orgánica y Química Farmacéutica, Facultad de Farmacia, Universidad de Sevilla, Sevilla, Spain
| | - Ignacio Periñán
- Departamento de Química Orgánica y Química Farmacéutica, Facultad de Farmacia, Universidad de Sevilla, Sevilla, Spain
| | - Francisco J. Miñano
- Unidad de Farmacología Experimental y Clínica (UFEC), Hospital Universitario de Valme, Universidad de Sevilla, Sevilla, Spain
| | - Juan Bautista
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, Sevilla, Spain
- * E-mail: (JDB); (MRG)
| | - Manuel Romero-Gómez
- Unidad de Gestión Clínica de Enfermedades Digestivas & Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Hospital Universitario de Valme, Sevilla, Spain
- * E-mail: (JDB); (MRG)
| |
Collapse
|
25
|
Paniz LG, Calcagnotto ME, Pandolfo P, Machado DG, Santos GF, Hansel G, Almeida RF, Bruch RS, Brum LM, Torres FV, de Assis AM, Rico EP, Souza DO. Neuroprotective effects of guanosine administration on behavioral, brain activity, neurochemical and redox parameters in a rat model of chronic hepatic encephalopathy. Metab Brain Dis 2014; 29:645-54. [PMID: 24788896 DOI: 10.1007/s11011-014-9548-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2014] [Accepted: 04/14/2014] [Indexed: 10/25/2022]
Abstract
It is well known that glutamatergic excitotoxicity and oxidative stress are implicated in the pathogenesis of hepatic encephalopathy (HE). The nucleoside guanosine exerts neuroprotective effects through the antagonism against glutamate neurotoxicity and antioxidant properties. In this study, we evaluated the neuroprotective effect of guanosine in an animal model of chronic HE. Rats underwent bile duct ligation (BDL) and 2 weeks later they were treated with i.p. injection of guanosine 7.5 mg/kg once a day for 1-week. We evaluated the effects of guanosine in HE studying several aspects: a) animal behavior using open field and Y-maze tasks; b) brain rhythm changes in electroencephalogram (EEG) recordings; c) purines and glutamate levels in the cerebral spinal fluid (CSF); and d) oxidative stress parameters in the brain. BDL rats presented increased levels of glutamate, purines and metabolites in the CSF, as well as increased oxidative damage. Guanosine was able not only to prevent these effects but also to attenuate the behavioral and EEG impairment induced by BDL. Our study shows the neuroprotective effects of systemic administration of guanosine in a rat model of HE and highlights the involvement of purinergic system in the physiopathology of this disease.
Collapse
Affiliation(s)
- L G Paniz
- Programa de Pós-graduação em Bioquímica, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul-UFRGS, Rua Ramiro Barcelos 2600 Anexo, 90035-003, Porto Alegre, RS, Brazil,
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Gualix J, Gómez-Villafuertes R, Pintor J, Llansola M, Felipo V, Miras-Portugal MT. Presence of diadenosine polyphosphates in microdialysis samples from rat cerebellum in vivo: effect of mild hyperammonemia on their receptors. Purinergic Signal 2013; 10:349-56. [PMID: 23943472 PMCID: PMC4040178 DOI: 10.1007/s11302-013-9382-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Accepted: 07/30/2013] [Indexed: 12/26/2022] Open
Abstract
Diadenosine triphosphate (Ap(3)A), diadenosine tetraphosphate (Ap(4)A), and diadenosine pentaphosphate (Ap(5)A) have been identified in microdialysis samples from the cerebellum of conscious freely moving rats, under basal conditions, by means of a high-performance liquid chromatography method. The occurrence of Ap(3)A in the cerebellar microdyalisates is noteworthy, as the presence of this compound in the interstitial medium in neural tissues has not been previously described. The concentrations measured for the diadenosine polyphosphates in the cerebellar dialysate were (in nanomolar) 10.5 ± 2.9, 5.4 ± 1.2, and 5.8 ± 1.3 for Ap(3)A, Ap(4)A, and Ap(5)A, respectively. These concentrations are in the range that allows the activation of the presynaptic dinucleotide receptor in nerve terminals. However, a possible interaction of these dinucleotides with other purinergic receptors cannot be ruled out, as rat cerebellum expresses a variety of P2X or P2Y receptors susceptible to be activated by diadenosine polyphosphates, such as the P2X1-4, P2Y(1), P2Y(2), P2Y(4), and P2Y(12) receptors, as demonstrated by quantitative real-time PCR. Also, the ecto-nucleotide pyrophosphatases/phosphodiesterases NPP1 and NPP3, able to hydrolyze the diadenosine polyphosphates and terminate their extracellular actions, are expressed in the rat cerebellum. All these evidences contribute to reinforce the role of diadenosine polyphosphates as signaling molecules in the central nervous system. Finally, we have analyzed the possible differences in the concentration of diadenosine polyphosphates in the cerebellar extracellular medium and changes in the expression levels of their receptors and hydrolyzing enzymes in an animal model of moderate hyperammonemia.
Collapse
Affiliation(s)
- Javier Gualix
- Departamento de Bioquímica, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, Spain,
| | | | | | | | | | | |
Collapse
|