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Milewski K, Orzeł-Gajowik K, Zielińska M. Mitochondrial Changes in Rat Brain Endothelial Cells Associated with Hepatic Encephalopathy: Relation to the Blood-Brain Barrier Dysfunction. Neurochem Res 2024; 49:1489-1504. [PMID: 35917006 PMCID: PMC11106209 DOI: 10.1007/s11064-022-03698-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 02/17/2022] [Accepted: 07/14/2022] [Indexed: 12/06/2022]
Abstract
The mechanisms underlying cerebral vascular dysfunction and edema during hepatic encephalopathy (HE) are unclear. Blood-brain barrier (BBB) impairment, resulting from increased vascular permeability, has been reported in acute and chronic HE. Mitochondrial dysfunction is a well-documented result of HE mainly affecting astrocytes, but much less so in the BBB-forming endothelial cells. Here we review literature reports and own experimental data obtained in HE models emphasizing alterations in mitochondrial dynamics and function as a possible contributor to the status of brain endothelial cell mitochondria in HE. Own studies on the expression of the mitochondrial fusion-fission controlling genes rendered HE animal model-dependent effects: increase of mitochondrial fusion controlling genes opa1, mfn1 in cerebral vessels in ammonium acetate-induced hyperammonemia, but a decrease of the two former genes and increase of fis1 in vessels in thioacetamide-induced HE. In endothelial cell line (RBE4) after 24 h ammonia and/or TNFα treatment, conditions mimicking crucial aspects of HE in vivo, we observed altered expression of mitochondrial fission/fusion genes: a decrease of opa1, mfn1, and, increase of the fission related fis1 gene. The effect in vitro was paralleled by the generation of reactive oxygen species, decreased total antioxidant capacity, decreased mitochondrial membrane potential, as well as increased permeability of RBE4 cell monolayer to fluorescein isothiocyanate dextran. Electron microscopy documented enlarged mitochondria in the brain endothelial cells of rats in both in vivo models. Collectively, the here observed alterations of cerebral endothelial mitochondria are indicative of their fission, and decreased potential of endothelial mitochondria are likely to contribute to BBB dysfunction in HE.
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Affiliation(s)
- Krzysztof Milewski
- Department of Neurotoxicology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Pawińskiego St. 5, 02-106, Warsaw, Poland.
| | - Karolina Orzeł-Gajowik
- Department of Neurotoxicology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Pawińskiego St. 5, 02-106, Warsaw, Poland
| | - Magdalena Zielińska
- Department of Neurotoxicology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Pawińskiego St. 5, 02-106, Warsaw, Poland.
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Lopes FF, Lamberty Faverzani J, Hammerschmidt T, Aguilar Delgado C, Ferreira de Oliveira J, Wajner M, Regla Vargas C. Evaluation of oxidative damage to biomolecules and inflammation in patients with urea cycle disorders. Arch Biochem Biophys 2023; 736:109526. [PMID: 36702451 DOI: 10.1016/j.abb.2023.109526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 01/11/2023] [Accepted: 01/22/2023] [Indexed: 01/26/2023]
Abstract
Urea cycle disorders (UCD) are inborn errors of metabolism that occur due to a loss of function in enzymes and transporters involved in the urea cycle, causing an intoxication by hyperammonemia and accumulation of metabolites. Patients can develop hepatic encephalopathy (HE), severe neurological and motor disabilities, and often death. The mechanisms involved in the pathophysiology of UCD are many and complex, but there are strong indications that oxidative stress and inflammation are present, being responsible for at least part of the cellular damage that occurs in these diseases. The aim of this study was to evaluate oxidative and nitrosative damage and inflammation in UCD, to better understand the pathophysiology mechanisms of these diseases. We evaluated the nitrite and nitrate content, thiobarbituric acid-reactive substances (TBARS), carbonyl protein content and a panel of cytokines in plasma sample of 14 patients. The UCD patients group consisted of individuals affected with ornithine transcarbamylase deficiency (n = 8), carbamoyl phosphate synthetase deficiency (n = 2), argininosuccinate synthetase deficiency (n = 2); arginase 1 deficiency (n = 1) and argininosuccinate lyase deficiency (n = 1). Patients mean age at diagnosis was 5.25 ± 9.86 years-old and mean concentrations were compared with healthy individuals of matched age and gender. We found a significant reduction in nitrogen reactive species in patients when compared to controls. TBARS was increased in patients, indicating lipid peroxidation. To evaluate protein oxidative damage in UCD, the carbonyl content was measured, and the results also demonstrated an increase in this biomarker. Finally, we found that UCD patients have enhanced concentrations of cytokines, with pro-inflammatory interleukins IL-6, IL-8, interferon-γ and TNF-α, and anti-inflammatory IL-10 being increased when compared to the control group. In conclusion, our results demonstrate that oxidative stress and inflammation occurs in UCD and probably contribute to the severe brain damage present in patients.
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Affiliation(s)
- Franciele Fátima Lopes
- Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, UFRGS, Brazil; Serviço de Genética Médica, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.
| | - Jéssica Lamberty Faverzani
- Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, UFRGS, Brazil; Serviço de Genética Médica, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | - Tatiane Hammerschmidt
- Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, UFRGS, Brazil; Serviço de Genética Médica, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | - Camila Aguilar Delgado
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Serviço de Genética Médica, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | - Julia Ferreira de Oliveira
- Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, UFRGS, Brazil; Serviço de Genética Médica, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | - Moacir Wajner
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Serviço de Genética Médica, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | - Carmen Regla Vargas
- Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, UFRGS, Brazil; Serviço de Genética Médica, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.
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Huang Y, Mo S, Jin Y, Zheng Z, Wang H, Wu S, Ren Z, Wu J. Ammonia-induced excess ROS causes impairment and apoptosis in porcine IPEC-J2 intestinal epithelial cells. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 243:114006. [PMID: 36037632 DOI: 10.1016/j.ecoenv.2022.114006] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 08/12/2022] [Accepted: 08/19/2022] [Indexed: 06/15/2023]
Abstract
Ammonia is one of the most important toxic metabolites in the intestine of animals. It can cause intestinal damage and associated intestinal diseases through different endogenous or exogenous stimuli. However, the definition of harmful ammonia concentration and the molecular mechanism of ammonia - induced intestinal epithelial injury remain unclear. In this study, we found that the viability of porcine IPEC-J2 intestinal epithelial cells significantly decreased with the increase of NH4Cl dose (20-80 mM). Ammonia (40 mM NH4Cl) increased the expression level of ammonia transporter RHCG and disrupted the intestinal barrier function of IPEC-J2 cells by reducing the expression levels of the tight junction molecules ZO-1 and Claudin-1. Ammonia caused elevated levels of ROS and apoptosis in IPEC-J2 cells. This was manifested by decreased activity of antioxidant enzymes SOD and GPx, decreased mitochondrial membrane potential, and increased cytoplasmic Ca2+ concentration. In addition, the expression levels of apoptosis-related molecules Caspase-9, Caspase-3, Fas, Caspase-8, p53 and Bax were increased, the expression level of anti-apoptotic molecule Bcl-2 was decreased. Moreover, the antioxidant NAC (N-acetyl-L-cysteamine) effectively alleviated ammonia-induced cytotoxicity, reduced ROS level, Ca2+ concentration, and the apoptosis of IPEC-J2 cells. The results suggest that ammonia-induced excess ROS triggered apoptosis through mitochondrial pathway, death receptor pathway and DNA damage. This study can provide reference and theoretical basis for the definition of harmful ammonia concentration in pig intestine and the effect and mechanism of ammonia on pig intestinal health.
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Affiliation(s)
- Yihao Huang
- College of Animal Sciences & Technology/College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
| | - Shangkun Mo
- College of Animal Sciences & Technology/College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
| | - Yi Jin
- College of Animal Sciences & Technology/College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
| | - Zhuoning Zheng
- College of Animal Sciences & Technology/College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
| | - Hanyi Wang
- College of Animal Sciences & Technology/College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
| | - Shaojuan Wu
- College of Animal Sciences & Technology/College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
| | - Zhuqing Ren
- College of Animal Sciences & Technology/College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; Hubei Hongshan Laboratory, Wuhan 430070, China.
| | - Jian Wu
- College of Animal Sciences & Technology/College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
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Molecular mechanisms and consequences of mitochondrial permeability transition. Nat Rev Mol Cell Biol 2022; 23:266-285. [PMID: 34880425 DOI: 10.1038/s41580-021-00433-y] [Citation(s) in RCA: 187] [Impact Index Per Article: 93.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/29/2021] [Indexed: 12/29/2022]
Abstract
Mitochondrial permeability transition (mPT) is a phenomenon that abruptly causes the flux of low molecular weight solutes (molecular weight up to 1,500) across the generally impermeable inner mitochondrial membrane. The mPT is mediated by the so-called mitochondrial permeability transition pore (mPTP), a supramolecular entity assembled at the interface of the inner and outer mitochondrial membranes. In contrast to mitochondrial outer membrane permeabilization, which mostly activates apoptosis, mPT can trigger different cellular responses, from the physiological regulation of mitophagy to the activation of apoptosis or necrosis. Although there are several molecular candidates for the mPTP, its molecular nature remains contentious. This lack of molecular data was a significant setback that prevented mechanistic insight into the mPTP, pharmacological targeting and the generation of informative animal models. In recent years, experimental evidence has highlighted mitochondrial F1Fo ATP synthase as a participant in mPTP formation, although a molecular model for its transition to the mPTP is still lacking. Recently, the resolution of the F1Fo ATP synthase structure by cryogenic electron microscopy led to a model for mPTP gating. The elusive molecular nature of the mPTP is now being clarified, marking a turning point for understanding mitochondrial biology and its pathophysiological ramifications. This Review provides an up-to-date reference for the understanding of the mammalian mPTP and its cellular functions. We review current insights into the molecular mechanisms of mPT and validated observations - from studies in vivo or in artificial membranes - on mPTP activity and functions. We end with a discussion of the contribution of the mPTP to human disease. Throughout the Review, we highlight the multiple unanswered questions and, when applicable, we also provide alternative interpretations of the recent discoveries.
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Bayat M, Khalili A, Bayat G, Akbari S, Yousefi Nejad A, Borhani Haghighi A, Haghani M. Effects of platelet-rich plasma on the memory impairment, apoptosis, and hippocampal synaptic plasticity in a rat model of hepatic encephalopathy. Brain Behav 2022; 12:e2447. [PMID: 34855284 PMCID: PMC8785608 DOI: 10.1002/brb3.2447] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 09/22/2021] [Accepted: 10/30/2021] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVES In the present study, we aimed to determine whether intraperitoneal injection of platelet-rich plasma (PRP) could have a neuroprotective effect on learning, memory, and synaptic plasticity impairment as well as hippocampal apoptosis in rats with hepatic encephalopathy induced by bile duct ligated (BDL). METHODS The rats were divided into four groups: the control, sham, BDL+ V (vehicle), and BDL+ PRP. The BDL rats were treated with PRP immediately after the surgery, and the injection was done every 3 days for 30 days. The passive avoidance and Morris water maze tests were used for the evaluation of learning and memory. The long-term potentiation (LTP), basal-synaptic transmission, and paired-pulse ratio, as an index for measurement of neurotransmitter release probability, were evaluated by field-potential recording. After taking a blood sample for assessment of the liver enzymes, the animals were sacrificed and their hippocampus was removed for evaluation of cleaved caspase-3 by Western blot. RESULTS Serological assessment of the liver function showed that BDL severely impaired the liver function. Also, PRP treatment could partially improve the liver dysfunction along with recovery in fear memory and spatial learning memory performance, LTP, basal-synaptic transmission, and neurotransmitter release probability. PRP-treated rats also showed a significant reduction in neuronal apoptosis in the CA1 area. CONCLUSIONS The results of this study suggest that PRP improves cognitive performance and synaptic plasticity in BDL rats via direct neuroprotective property and/or indirectly by improvement of hepatic dysfunction.
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Affiliation(s)
- Mahnaz Bayat
- Clinical Neurology Research Centre, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Azadeh Khalili
- Department of Physiology-Pharmacology-Medical Physic, School of Medicine, Alborz University of Medical Sciences, Karaj, Iran
| | - Gholamreza Bayat
- Department of Physiology-Pharmacology-Medical Physic, School of Medicine, Alborz University of Medical Sciences, Karaj, Iran.,Cardiovascular Research Center, Alborz University of Medical Sciences, Karaj, Iran
| | - Somayeh Akbari
- Department of Physiology, The Medical School, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Amirhossein Yousefi Nejad
- Faculty of Veterinary Medicine, Department of Veterinary Medicine, Islamic Azad University of Kazeroon, Shiraz, Iran
| | | | - Masoud Haghani
- Department of Physiology, The Medical School, Shiraz University of Medical Sciences, Shiraz, Iran.,Histomorphometry and Stereology Research Centre, Shiraz University of Medical Sciences, Shiraz, Iran
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Kim YK, Song J. Therapeutic Applications of Resveratrol in Hepatic Encephalopathy through Its Regulation of the Microbiota, Brain Edema, and Inflammation. J Clin Med 2021; 10:jcm10173819. [PMID: 34501267 PMCID: PMC8432232 DOI: 10.3390/jcm10173819] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 08/22/2021] [Accepted: 08/24/2021] [Indexed: 02/07/2023] Open
Abstract
Hepatic encephalopathy is a common complication in patients with liver cirrhosis and portosystemic shunting. Patients with hepatic encephalopathy present a variety of clinical features, including neuropsychiatric manifestations, cognitive dysfunction, impaired gut barrier function, hyperammonemia, and chronic neuroinflammation. These pathogeneses have been linked to various factors, including ammonia-induced oxidative stress, neuronal cell death, alterations in the gut microbiome, astrocyte swelling, and blood-brain barrier disruptions. Many researchers have focused on identifying novel therapeutics and prebiotics in the hope of improving the treatment of these conditions. Resveratrol is a natural polyphenic compound and is known to exert several pharmacological effects, including antioxidant, anti-inflammatory, and neuroprotective activities. Recent studies suggest that resveratrol contributes to improving the neuropathogenic effects of liver failure. Here, we review the current evidence describing resveratrol's effects in neuropathogenesis and its impact on the gut-liver axis relating to hepatic encephalopathy. We highlight the hypothesis that resveratrol exerts diverse effects in hepatic encephalopathy and suggest that these effects are likely mediated by changes to the gut microbiota, brain edema, and neuroinflammation.
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Affiliation(s)
- Young-Kook Kim
- Department of Biochemistry, Chonnam National University Medical School, Hwasun 58128, Jeollanam-do, 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
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Dominguini D, Dall'igna DM, Nogueira L, Steckert AV, GonÇalves RC, Michels M, Quevedo J, Ritter C, Barichello T, Dal-Pizzol F. Ammonia exposition during gestation induces neonatal oxidative damage in the brain and long-term cognitive alteration in rats. AN ACAD BRAS CIENC 2020; 92:e20190925. [PMID: 33295575 DOI: 10.1590/0001-3765202020190925] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 10/07/2020] [Indexed: 11/22/2022] Open
Abstract
Ammonia is involved in the pathogenesis of neurological conditions associated with hyperammonemia, including hepatic encephalopathy. Few is known about the effects of gestational exposition to ammonia in the developing brain, and the possible long-term consequences of such exposure. We aimed to evaluate the effects of ammonia exposure during the gestation and the possible long-term cognitive alterations on pups. Eight female rats were divided into two groups: (1) control (saline solution); (2) ammonia (ammonium acetate, 2,5mmol/Kg). Each rat received a single subcutaneous injection during all gestational period. The brains from 1-day-old rats were obtained to the determination of thiobarbituric acid reactive species (TBARS), protein carbonyl and nitrite/nitrate levels. Some animals were followed 30 days after delivery and were subjected to the step-down inhibitory avoidance task. It was observed a significant increase in protein carbonyl, but not TBARS or nitrite/nitrate levels, in pups exposed to ammonia. Rats exposed to ammonia presented long-term cognitive impairment. Gestational exposition to ammonia induces protein oxidative damage in the neonatal rat brain, and long-term cognitive impairment.
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Affiliation(s)
- Diogo Dominguini
- Programa de Pós-Graduação em Ciências da Saúde, Universidade do Extremo Sul Catarinense/UNESC, Laboratório de Fisiopatologia Experimental, Av. Universitária, 1105, Universitário, 88806-000 Criciúma, SC, Brazil
| | - DhÉbora M Dall'igna
- Programa de Pós-Graduação em Ciências da Saúde, Universidade do Extremo Sul Catarinense/UNESC, Laboratório de Fisiopatologia Experimental, Av. Universitária, 1105, Universitário, 88806-000 Criciúma, SC, Brazil
| | - Lauro Nogueira
- Programa de Pós-Graduação em Ciências da Saúde, Universidade do Extremo Sul Catarinense/UNESC, Laboratório de Fisiopatologia Experimental, Av. Universitária, 1105, Universitário, 88806-000 Criciúma, SC, Brazil
| | - Amanda V Steckert
- Programa de Pós-Graduação em Ciências da Saúde, Universidade do Extremo Sul Catarinense/UNESC, Laboratório de Fisiopatologia Experimental, Av. Universitária, 1105, Universitário, 88806-000 Criciúma, SC, Brazil
| | - Renata C GonÇalves
- Programa de Pós-Graduação em Ciências da Saúde, Universidade do Extremo Sul Catarinense/UNESC, Laboratório de Fisiopatologia Experimental, Av. Universitária, 1105, Universitário, 88806-000 Criciúma, SC, Brazil
| | - Monique Michels
- Programa de Pós-Graduação em Ciências da Saúde, Universidade do Extremo Sul Catarinense/UNESC, Laboratório de Fisiopatologia Experimental, Av. Universitária, 1105, Universitário, 88806-000 Criciúma, SC, Brazil
| | - JoÃo Quevedo
- Translational Psychiatry Program, Department of Psychiatry and Behavioral Sciences, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX, 77054, USA
- Center of Excellence on Mood Disorders, Department of Psychiatry and Behavioral Sciences, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX, 77054, USA
- Neuroscience Graduate Program, The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX, 77054, USA
| | - Cristiane Ritter
- Programa de Pós-Graduação em Ciências da Saúde, Universidade do Extremo Sul Catarinense/UNESC, Laboratório de Fisiopatologia Experimental, Av. Universitária, 1105, Universitário, 88806-000 Criciúma, SC, Brazil
| | - Tatiana Barichello
- Programa de Pós-Graduação em Ciências da Saúde, Universidade do Extremo Sul Catarinense/UNESC, Laboratório de Fisiopatologia Experimental, Av. Universitária, 1105, Universitário, 88806-000 Criciúma, SC, Brazil
- Translational Psychiatry Program, Department of Psychiatry and Behavioral Sciences, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX, 77054, USA
- Center of Excellence on Mood Disorders, Department of Psychiatry and Behavioral Sciences, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX, 77054, USA
- Neuroscience Graduate Program, The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX, 77054, USA
| | - Felipe Dal-Pizzol
- Programa de Pós-Graduação em Ciências da Saúde, Universidade do Extremo Sul Catarinense/UNESC, Laboratório de Fisiopatologia Experimental, Av. Universitária, 1105, Universitário, 88806-000 Criciúma, SC, Brazil
- Programa de Pós-Graduação em Ciências Médicas, Universidade Federal de Santa Catarina/UFSC, Centro de Excelência em Neurociências Aplicadas de Santa Catarina/ NENASC, Rua Eng. Agronômico Andrei Cristian Ferreira, s/n, Trindade, 88040-900 Florianópolis, SC, Brazil
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Muke I, Sprenger A, Bobylev I, Wiemer V, Barham M, Neiss WF, Lehmann HC. Ultrastructural characterization of mitochondrial damage in experimental autoimmune neuritis. J Neuroimmunol 2020; 343:577218. [PMID: 32251941 DOI: 10.1016/j.jneuroim.2020.577218] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 03/16/2020] [Accepted: 03/18/2020] [Indexed: 12/11/2022]
Abstract
Data are sparse about mitochondrial damage in GBS and in its most frequently employed animal model, experimental autoimmune neuritis (EAN). We here characterized changes in mitochondrial content and morphology at different time points during EAN by use of ultrastructural imaging and immunofluorescent labelling. Histological examination revealed that demyelinated axons and their adjacent Schwann cells showed reduced mitochondrial content and remaining mitochondria appeared swollen with greater diameter in Schwann cells and unmyelinated axons. Our findings indicate that in EAN, particularly mitochondria in Schwann cells are damaged. Further studies are warranted to address whether these changes are amenable to novel, mitoprotective treatments.
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Affiliation(s)
- Ines Muke
- Department of Neurology, Faculty of Medicine and University Hospital Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Germany
| | - Alina Sprenger
- Department of Neurology, Faculty of Medicine and University Hospital Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Germany
| | - Ilja Bobylev
- Department of Neurology, Faculty of Medicine and University Hospital Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Germany
| | - Valerie Wiemer
- Department of Neurology, Faculty of Medicine and University Hospital Cologne, Germany
| | - Mohammed Barham
- Department of Anatomy I, Faculty of Medicine, University of Cologne, Germany
| | | | - Helmar Christoph Lehmann
- Department of Neurology, Faculty of Medicine and University Hospital Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Germany.
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Liotta EM, Kimberly WT. Cerebral edema and liver disease: Classic perspectives and contemporary hypotheses on mechanism. Neurosci Lett 2020; 721:134818. [PMID: 32035166 DOI: 10.1016/j.neulet.2020.134818] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 02/01/2020] [Accepted: 02/03/2020] [Indexed: 02/07/2023]
Abstract
Liver disease is a growing public health concern. Hepatic encephalopathy, the syndrome of brain dysfunction secondary to liver disease, is a frequent complication of both acute and chronic liver disease and cerebral edema (CE) is a key feature. While altered ammonia metabolism is a key contributor to hepatic encephalopathy and CE in liver disease, there is a growing appreciation that additional mechanisms contribute to CE. In this review we will begin by presenting three classic perspectives that form a foundation for a discussion of CE in liver disease: 1) CE is unique to acute liver failure, 2) CE in liver disease is only cytotoxic, and 3) CE in liver disease is primarily an osmotically mediated consequence of ammonia and glutamine metabolism. We will present each classic perspective along with more recent observations that call in to question that classic perspective. After highlighting these areas of debate, we will explore the leading contemporary mechanisms hypothesized to contribute to CE during liver disease.
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Affiliation(s)
- Eric M Liotta
- Northwestern University-Feinberg School of Medicine, Department of Neurology, United States; Northwestern University-Feinberg School of Medicine, Department of Surgery, Division of Organ Transplantation, United States; Northwestern University Transplant Outcomes Research Collaboration, United States.
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10
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Zielonka M, Probst J, Carl M, Hoffmann GF, Kölker S, Okun JG. Bioenergetic dysfunction in a zebrafish model of acute hyperammonemic decompensation. Exp Neurol 2019; 314:91-99. [PMID: 30653968 DOI: 10.1016/j.expneurol.2019.01.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 12/18/2018] [Accepted: 01/12/2019] [Indexed: 12/30/2022]
Abstract
Acute hyperammonemic encephalopathy is a life-threatening manifestation of individuals with urea cycle disorders, which is associated with high mortality rates and severe neurological sequelae in survivors. Cerebral bioenergetic failure has been proposed as one of the key mechanisms underlying hyperammonemia-induced brain damage, but data supporting this hypothesis remain inconclusive and partially contradictory. Using a previously established zebrafish model of acute hyperammonemic decompensation, we unraveled that acute hyperammonemia leads to a transamination-dependent withdrawal of 2-oxoglutarate (alpha-ketoglutarate) from the tricarboxylic acid (TCA) cycle with consecutive TCA cycle dysfunction, ultimately causing impaired oxidative phosphorylation with ATP shortage, decreased ATP/ADP-ratio and elevated lactate concentrations. Thus, our study supports and extends the hypothesis that cerebral bioenergetic dysfunction is an important pathophysiological hallmark of hyperammonemia-induced neurotoxicity.
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Affiliation(s)
- Matthias Zielonka
- Center for Child and Adolescent Medicine, Division for Pediatric Neurology and Metabolic Medicine, University Hospital Heidelberg, Heidelberg, Germany; Heidelberg Research Center for Molecular Medicine (HRCMM), Heidelberg, Germany.
| | - Joris Probst
- Center for Child and Adolescent Medicine, Division for Pediatric Neurology and Metabolic Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Matthias Carl
- Center for Integrative Biology (CIBIO), Laboratory of Translational Neurogenetics, University of Trento, Trento, Italy
| | - Georg Friedrich Hoffmann
- Center for Child and Adolescent Medicine, Division for Pediatric Neurology and Metabolic Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Stefan Kölker
- Center for Child and Adolescent Medicine, Division for Pediatric Neurology and Metabolic Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Jürgen Günther Okun
- Center for Child and Adolescent Medicine, Division for Pediatric Neurology and Metabolic Medicine, University Hospital Heidelberg, Heidelberg, Germany
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Bai Y, Wang Y, Yang Y. Hepatic encephalopathy changes mitochondrial dynamics and autophagy in the substantia nigra. Metab Brain Dis 2018; 33:1669-1678. [PMID: 29998403 DOI: 10.1007/s11011-018-0275-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 06/19/2018] [Indexed: 12/24/2022]
Abstract
Hepatic encephalopathy (HE) has been reported in more than 40% of patients with cirrhosis in clinical practice. HE changes mitochondrial dysfunction. Mitochondrial dynamics and autophagy are important for maintaining and removing damaged mitochondria. We used molecular biology and morphology methods to evaluate changes in mitochondrial dynamics and autophagy of the substantia nigra (SN) and prefrontal cortex (PFC) in HE. In this study, we observed that HE increased mitochondrial dynamics and autophagy in the SN, which was not seen in the PFC. HE stimulated dynamin-related protein 1 (DRP1) transformation from the cytosolic to the mitochondria within SN cells, which increased mitochondrial fission and the number of mitochondria. The fusion protein L-OPA1 (long isoforms of OPA1) was increased in the SN of HE mice. HE also increased the levels of autophagy proteins PINK1/PARKIN and P62/LC3-B in the SN, which can selectively remove damaged mitochondria and cell, respectively. Additionally, we used electron microscopy to directly observe changes in mitochondrial morphology in the SN of HE mice and found the number of mitochondria was increased. However, there were no significant changes in the fission, fusion or autophagy proteins in PFC-purified mitochondrial proteins in HE mice. The number of mitochondria also did not show alterations in the PFC of HE mice compared with that in a sham group. These results illustrate that mitochondria can protect themselves by changing the dynamics and autophagy in the SN of HE mice. Changes in the mitochondrial dynamics and autophagy related to HE can help repair damaged mitochondria and provide a further understanding of the mechanisms of hepatic encephalopathy.
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Affiliation(s)
- Yunhu Bai
- Department of Hepatobiliary Surgery, Xi-Jing Hospital, Fourth Military Medical University, Xi'an, 710032, China
| | - Yayun Wang
- Department of Anatomy and K.K. Leung Brain Research Centre, Fourth Military Medical University, Xi'an, 710032, China
| | - Yanling Yang
- Department of Hepatobiliary Surgery, Xi-Jing Hospital, Fourth Military Medical University, Xi'an, 710032, China.
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12
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Zielonka M, Breuer M, Okun JG, Carl M, Hoffmann GF, Kölker S. Pharmacologic rescue of hyperammonemia-induced toxicity in zebrafish by inhibition of ornithine aminotransferase. PLoS One 2018; 13:e0203707. [PMID: 30199544 PMCID: PMC6130883 DOI: 10.1371/journal.pone.0203707] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 08/24/2018] [Indexed: 12/30/2022] Open
Abstract
Hyperammonemia is the common biochemical hallmark of urea cycle disorders, activating neurotoxic pathways. If untreated, affected individuals have a high risk of irreversible brain damage and mortality. Here we show that acute hyperammonemia strongly enhances transamination-dependent formation of osmolytic glutamine and excitatory glutamate, thereby inducing neurotoxicity and death in ammoniotelic zebrafish larvae via synergistically acting overactivation of NMDA receptors and bioenergetic impairment induced by depletion of 2-oxoglutarate. Intriguingly, specific and irreversible inhibition of ornithine aminotransferase (OAT) by 5-fluoromethylornithine rescues zebrafish from lethal concentrations of ammonium acetate and corrects hyperammonemia-induced biochemical alterations. Thus, OAT inhibition is a promising and effective therapeutic approach for preventing neurotoxicity and mortality in acute hyperammonemia.
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Affiliation(s)
- Matthias Zielonka
- University Hospital Heidelberg, Center for Child and Adolescent Medicine, Division for Pediatric Neurology and Metabolic Medicine, Heidelberg, Germany
- Heidelberg Research Center for Molecular Medicine (HRCMM), Heidelberg, Germany
- * E-mail:
| | - Maximilian Breuer
- University Hospital Heidelberg, Center for Child and Adolescent Medicine, Division for Pediatric Neurology and Metabolic Medicine, Heidelberg, Germany
| | - Jürgen Günther Okun
- University Hospital Heidelberg, Center for Child and Adolescent Medicine, Division for Pediatric Neurology and Metabolic Medicine, Heidelberg, Germany
| | - Matthias Carl
- Heidelberg University, Medical Faculty Mannheim, Department of Cell and Molecular Biology, Mannheim, Germany
- University of Trento, Center for Integrative Biology (CIBIO), Laboratory of Translational Neurogenetics, Trento, Italy
| | - Georg Friedrich Hoffmann
- University Hospital Heidelberg, Center for Child and Adolescent Medicine, Division for Pediatric Neurology and Metabolic Medicine, Heidelberg, Germany
| | - Stefan Kölker
- University Hospital Heidelberg, Center for Child and Adolescent Medicine, Division for Pediatric Neurology and Metabolic Medicine, Heidelberg, Germany
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13
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Bobermin LD, Souza DO, Gonçalves CA, Quincozes-Santos A. Resveratrol prevents ammonia-induced mitochondrial dysfunction and cellular redox imbalance in C6 astroglial cells. Nutr Neurosci 2017; 21:276-285. [PMID: 28165879 DOI: 10.1080/1028415x.2017.1284375] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
BACKGROUND Resveratrol is a polyphenolic compound that presents several protective effects in the central nervous system, including gliotoxicity associated to hyperammonemia, a key element for the development of hepatic encephalopathy. In this condition, mitochondrial dysfunction leads to a reactive oxygen species (ROS) overproduction, which, in turn, exacerbates mitochondrial failure and causes cellular damage. OBJECTIVE This study sought to determine whether prevention of mitochondrial dysfunction and the maintenance of cellular redox status by resveratrol contribute to its protective action toward ammonia toxicity. METHODS C6 astrocyte cell line was pre-incubated in the presence or absence of resveratrol (100 μM) for 1 hour. After pre-incubation, resveratrol was maintained and 5 mM ammonia was added for 24 hours, followed by the evaluation of ROS production, mitochondrial functionality, antioxidant enzymatic and non-enzymatic defenses, energy metabolic parameters, and genotoxicity. RESULTS We showed that resveratrol prevented the increase in ROS production, the decrease of mitochondrial membrane potential (ΔΨm), and bioenergetics deficit caused by ammonia in C6 astroglial cells. In addition, resveratrol avoided the ammonia-induced upregulation of NOX activity and impairment in enzymatic and non-enzymatic antioxidant defenses. Ammonia also induced DNA damage that was prevented by resveratrol, indicating its genoprotective effect. CONCLUSIONS In summary, our study demonstrates that resveratrol prevents ammonia-induced cytotoxicity, as well as supports the role of resveratrol on mitochondrial/cellular redox functionality.
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Affiliation(s)
- Larissa Daniele Bobermin
- a Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Diogo Onofre Souza
- a Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Carlos-Alberto Gonçalves
- a Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - André Quincozes-Santos
- a Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
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14
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Milewski K, Oria M. What we know: the inflammatory basis of hepatic encephalopathy. Metab Brain Dis 2016; 31:1239-1247. [PMID: 26497651 DOI: 10.1007/s11011-015-9740-7] [Citation(s) in RCA: 4] [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: 06/16/2015] [Accepted: 09/24/2015] [Indexed: 02/07/2023]
Abstract
Central Nervous System (CNS) degeneration appearing in patients with cirrhosis is responsible for cognitive and persistent motor impairments that lead to an important impact on life quality. Brain injury affects certain areas of the CNS that might affect two types of cells: neurons and astrocytes. The process leading to brain injury could be induced by portosystemic shunting accompanied by hyperammonemia and by the activation of peripheral inflammation, manifested as episodic encephalopathy. Hyperammonemia combined with a decrease on the BCA/AAA ratio induces alterations of energetic metabolism and the formation of free radicals in the CNS. This process would be stimulated by the activation of peripheral inflammatory mediators that could act on receptors of the blood brain barrier such as TLR4, activating inflammatory responses in the CNS. As a result, a persistent activation of microglia and an irreversible neuronal and astrocytic injury would be induced. A new knowledge of the mechanisms leading to brain injury in cirrhosis would develop protective strategies to correct changes of nitrogen metabolism and inflammation.
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Affiliation(s)
- K Milewski
- Department of Neurotoxicology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Pawińskiego 5 Str, 02-106, Warsaw, Poland
| | - M Oria
- Translational Research in Fetal Surgery for Congenital Malformations, Center for Fetal, Cellular and Molecular Therapy, Division of Pediatric General and Thoracic Surgery, Cincinnati Children's Hospital Medical Center (CCHMC), 3333 Burnet Avenue, MLC 11020, S 8.400 AT, Cincinnati, OH, 45229-3039, USA.
- Liver Failure Group, UCL Institute for Liver and Digestive Health, Royal Free Hospital, University College London, London, UK.
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15
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Karababa A, Groos-Sahr K, Albrecht U, Keitel V, Shafigullina A, Görg B, Häussinger D. Ammonia Attenuates LPS-Induced Upregulation of Pro-Inflammatory Cytokine mRNA in Co-Cultured Astrocytes and Microglia. Neurochem Res 2016; 42:737-749. [PMID: 27655254 DOI: 10.1007/s11064-016-2060-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 09/03/2016] [Accepted: 09/08/2016] [Indexed: 12/19/2022]
Abstract
Hepatic encephalopathy (HE) is associated with cerebral microglia activation. Ammonia, a major toxin of HE, activates microglia in vitro but does not trigger pro-inflammatory cytokine synthesis. In the present study we analysed effects of ammonia on lipopolysaccharide (LPS)-induced upregulation of microglia activation and cytokine mRNA as well as on cytokine secretion in mono-cultured microglia and co-cultured astrocytes and microglia. In mono-cultured microglia LPS (100 ng/ml, 18 h) strongly elevated mRNA levels of the microglia activation marker CD14 and the pro-inflammatory cytokines IL-1α/β, IL-6 and TNF-α. NH4Cl (5 mmol/l) had no effect on LPS-induced upregulation of CD14, IL-1α/β and IL-6 mRNA but enhanced LPS-induced upregulation of TNF-α mRNA in mono-cultured microglia. In co-cultured astrocytes and microglia, however, LPS-induced upregulation of IL-1α/β, TNF-α, IL-6, CD14 but not of IL-10, IL-12A/B or TGFβ1-3 mRNA was attenuated by NH4Cl. LPS-induced upregulation of IL-1α/β, IL-6 and TNF-α was also diminished by the TGR5-ligands allopregnanolone and taurolithocholic acid in mono-cultured microglia. NH4Cl also attenuated LPS-induced release of MCP-1, IL-6 and IL-10 in mono-cultured microglia. mRNA level of surrogate marker for microglia activation (CD14) and for the anti-inflammatory M2-type microglia (CD163, CXCL1, CXCL2) were also elevated in post mortem brain tissue taken from the fusiforme gyrus of patients with liver cirrhosis and HE. The findings suggest that ammonia attenuates LPS-induced microglia reactivity in an astrocyte-dependent way. One may speculate that these anti-inflammatory effects of ammonia may be triggered by neurosteroids derived from astrocytes and may account for absence of microglia reactivity in cerebral cortex of cirrhotic patients with HE.
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Affiliation(s)
- Ayse Karababa
- Clinic for Gastroenterology, Hepatology and Infectious Diseases, Heinrich-Heine-University, Moorenstrasse 5, D-40225, Düsseldorf, Germany
| | - Katerina Groos-Sahr
- Clinic for Gastroenterology, Hepatology and Infectious Diseases, Heinrich-Heine-University, Moorenstrasse 5, D-40225, Düsseldorf, Germany
| | - Ute Albrecht
- Clinic for Gastroenterology, Hepatology and Infectious Diseases, Heinrich-Heine-University, Moorenstrasse 5, D-40225, Düsseldorf, Germany
| | - Verena Keitel
- Clinic for Gastroenterology, Hepatology and Infectious Diseases, Heinrich-Heine-University, Moorenstrasse 5, D-40225, Düsseldorf, Germany
| | - Aygul Shafigullina
- Clinic for Gastroenterology, Hepatology and Infectious Diseases, Heinrich-Heine-University, Moorenstrasse 5, D-40225, Düsseldorf, Germany
| | - Boris Görg
- Clinic for Gastroenterology, Hepatology and Infectious Diseases, Heinrich-Heine-University, Moorenstrasse 5, D-40225, Düsseldorf, Germany
| | - Dieter Häussinger
- Clinic for Gastroenterology, Hepatology and Infectious Diseases, Heinrich-Heine-University, Moorenstrasse 5, D-40225, Düsseldorf, Germany.
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16
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Neurotoxicity of Ammonia. Neurochem Res 2016; 42:713-720. [PMID: 27465396 DOI: 10.1007/s11064-016-2014-x] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 07/15/2016] [Accepted: 07/21/2016] [Indexed: 12/25/2022]
Abstract
Abnormal liver function has dramatic effects on brain functions. Hyperammonemia interferes profoundly with brain metabolism, astrocyte volume regulation, and in particular mitochondrial functions. Gene expression in the brain and excitatory and inhibitory neurotransmission circuits are also affected. Experiments with a number of pertinent animal models have revealed several potential mechanisms which could underlie the pathological phenomena occurring in hepatic encephalopathy.
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17
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Mladenović D, Petronijević N, Stojković T, Velimirović M, Jevtić G, Hrnčić D, Radosavljević T, Rašić-Marković A, Maksić N, Djuric D, Stanojlović O. Finasteride Has Regionally Different Effects on Brain Oxidative Stress and Acetylcholinesterase Activity in Acute Thioacetamide-Induced Hepatic Encephalopathy in Rats. PLoS One 2015; 10:e0134434. [PMID: 26241899 PMCID: PMC4524603 DOI: 10.1371/journal.pone.0134434] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 07/10/2015] [Indexed: 02/05/2023] Open
Abstract
Finasteride (FIN) inhibits neurosteroid synthesis and potentially improves the course of hepatic encephalopathy (HE). This study aimed to investigate the effects of FIN on brain oxidative stress and acetylcholinesterase (AchE) activity in acute thioacetamide-induced HE in rats. Male Wistar rats were divided into groups: 1. control; 2. thioacetamide-treated group (TAA; 900 mg/kg); 3. finasteride-treated group (FIN; 150 mg/kg); 4. group treated with FIN and TAA (FIN+TAA). Daily doses of FIN (50 mg/kg) and TAA (300 mg/kg) were administered intraperitoneally during three days and in FIN+TAA group FIN was administered 2h before every dose of TAA. FIN pretreatment prevented TAA-induced rise in malondialdehyde level in the cortex due to restoration of catalase activity and increased expression of superoxide dismutase 1 (SOD1) and induced an increase in malondialdehyde level in the thalamus due to reduction of glutathione peroxidase (GPx) and glutathione reductase (GR) activity. Although FIN pretreatment did not affect malondialdehyde level in hippocampus and caudate nucleus, hippocampal SOD1 expression was higher (p<0.05) and GR activity lower in FIN+TAA vs. TAA group (p<0.05). GPx activity was lower in caudate nucleus in FIN+TAA vs. TAA group (p<0.01). FIN pretreatment prevented TAA-induced rise in AchE activity in the thalamus and caudate nucleus and AchE activity correlates inversely in the thalamus (p<0.05) and positively in caudate nucleus (p<0.01) with malondialdehyde level. FIN has regionally selective effects on oxidative stress and AchE activity in the brain in acute TAA-induced HE in rats. The prooxidant role of FIN in the thalamus may be causally linked with inhibition of AchE.
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Affiliation(s)
- Dušan Mladenović
- Institute of Pathophysiology "Ljubodrag Buba Mihailovic", Faculty of Medicine, University of Belgrade, Dr Subotica 9, Belgrade, Serbia
| | - Nataša Petronijević
- Institute of Medical and Clinical Biochemistry, Faculty of Medicine, University of Belgrade, Pasterova 2, Belgrade, Serbia
| | - Tihomir Stojković
- Institute of Medical and Clinical Biochemistry, Faculty of Medicine, University of Belgrade, Pasterova 2, Belgrade, Serbia
| | - Milica Velimirović
- Institute of Medical and Clinical Biochemistry, Faculty of Medicine, University of Belgrade, Pasterova 2, Belgrade, Serbia
| | - Gordana Jevtić
- Institute of Medical and Clinical Biochemistry, Faculty of Medicine, University of Belgrade, Pasterova 2, Belgrade, Serbia
| | - Dragan Hrnčić
- Institute of Medical Physiology "Richard Burian", Faculty of Medicine, University of Belgrade, Višegradska 26/II, Belgrade, Serbia
| | - Tatjana Radosavljević
- Institute of Pathophysiology "Ljubodrag Buba Mihailovic", Faculty of Medicine, University of Belgrade, Dr Subotica 9, Belgrade, Serbia
| | - Aleksandra Rašić-Marković
- Institute of Medical Physiology "Richard Burian", Faculty of Medicine, University of Belgrade, Višegradska 26/II, Belgrade, Serbia
| | - Nebojša Maksić
- Centre for Medical Biochemistry, Clinical Centre of Serbia, Pasterova 2, Belgrade, Serbia
| | - Dragan Djuric
- Institute of Medical Physiology "Richard Burian", Faculty of Medicine, University of Belgrade, Višegradska 26/II, Belgrade, Serbia
| | - Olivera Stanojlović
- Institute of Medical Physiology "Richard Burian", Faculty of Medicine, University of Belgrade, Višegradska 26/II, Belgrade, Serbia
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18
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Rama Rao KV, Jayakumar AR, Norenberg MD. Brain edema in acute liver failure: mechanisms and concepts. Metab Brain Dis 2014; 29:927-36. [PMID: 24567229 DOI: 10.1007/s11011-014-9502-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Accepted: 02/05/2014] [Indexed: 12/18/2022]
Abstract
Brain edema and associated increase in intracranial pressure continue to be lethal complications of acute liver failure (ALF). Abundant evidence suggests that the edema in ALF is largely cytotoxic brought about by swelling of astrocytes. Elevated blood and brain ammonia levels have been strongly implicated in the development of the brain edema. Additionally, inflammation and sepsis have been shown to contribute to the astrocyte swelling/brain edema in the setting of ALF. We posit that ammonia initiates a number of signaling events, including oxidative/nitrative stress (ONS), the mitochondrial permeability transition (mPT), activation of the transcription factor (NF-κB) and signaling kinases, all of which have been shown to contribute to the mechanism of astrocyte swelling. All of these factors also impact ion-transporters, including Na(+), K(+), Cl(-) cotransporter and the sulfonylurea receptor 1, as well as the water channel protein aquaporin-4 resulting in a perturbation of cellular ion and water homeostasis, ultimately resulting in astrocyte swelling/brain edema. All of these events are also potentiated by inflammation. This article reviews contemporary knowledge regarding mechanisms of astrocyte swelling/brain edema formation which hopefully will facilitate the identification of therapeutic targets capable of mitigating the brain edema associated with ALF.
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Affiliation(s)
- Kakulavarapu V Rama Rao
- Department of Pathology, University of Miami Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA,
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19
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Faleiros BE, Miranda AS, Campos AC, Gomides LF, Kangussu LM, Guatimosim C, Camargos ERS, Menezes GB, Rachid MA, Teixeira AL. Up-regulation of brain cytokines and chemokines mediates neurotoxicity in early acute liver failure by a mechanism independent of microglial activation. Brain Res 2014; 1578:49-59. [PMID: 25017944 DOI: 10.1016/j.brainres.2014.07.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Revised: 06/07/2014] [Accepted: 07/01/2014] [Indexed: 12/12/2022]
Abstract
The neurological involvement in acute liver failure (ALF) is characterized by arousal impairment with progression to coma. There is a growing body of evidence that neuroinflammatory mechanisms play a role in this process, including production of inflammatory cytokines and microglial activation. However, it is still uncertain whether brain-derived cytokines and glial cells are crucial to the pathophysiology of ALF at the early stage, before coma development. Here, we investigated the influence of cytokines and microglia in ALF-induced encephalopathy in mice as soon as neurological symptoms were identifiable. Behavior was assessed at 12, 24, 36 and 48 h post-injection of thioacetamide, a hepatotoxic drug, through locomotor activity by an open field test. Brain concentration of cytokines (TNF-α and IL-1β) and chemokines (CXCL1, CCL2, CCL3 and CCL5) were assessed by ELISA. Microglial activation in brain sections was investigated through immunohistochemistry, and cellular ultrastructural changes were observed by transmission electron microscopy. We found that ALF-induced animals presented a significant decrease in locomotor activity at 24 h, which was accompanied by an increase in IL-1β, CXCL1, CCL2, CCL3 and CCL5 in the brain. TNF-α level was significantly increased only at 36 h. Despite marked morphological changes in astrocytes and brain endothelial cells, no microglial activation was observed. These findings suggest an involvement of brain-derived chemokines and IL-1β in early pathophysiology of ALF by a mechanism independent of microglial activation.
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Affiliation(s)
- Bruno E Faleiros
- Interdisciplinary Laboratory of Medical Investigation, School of Medicine, Universidade Federal de Minas Gerais, Avenida Alfredo Balena 190, Santa Efigênia, Belo Horizonte, MG 30130-100, Brazil.
| | - Aline S Miranda
- Interdisciplinary Laboratory of Medical Investigation, School of Medicine, Universidade Federal de Minas Gerais, Avenida Alfredo Balena 190, Santa Efigênia, Belo Horizonte, MG 30130-100, Brazil
| | - Alline C Campos
- Interdisciplinary Laboratory of Medical Investigation, School of Medicine, Universidade Federal de Minas Gerais, Avenida Alfredo Balena 190, Santa Efigênia, Belo Horizonte, MG 30130-100, Brazil
| | - Lindisley F Gomides
- Department of Morphology, Institute of Biological Sciences, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Avenida Antônio Carlos 6627, Pampulha, Belo Horizonte, MG 31270-901, Brazil
| | - Lucas M Kangussu
- Department of Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Avenida Antônio Carlos 6627, Pampulha, Belo Horizonte, MG 31270-901, Brazil
| | - Cristina Guatimosim
- Department of Morphology, Institute of Biological Sciences, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Avenida Antônio Carlos 6627, Pampulha, Belo Horizonte, MG 31270-901, Brazil
| | - Elizabeth R S Camargos
- Department of Morphology, Institute of Biological Sciences, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Avenida Antônio Carlos 6627, Pampulha, Belo Horizonte, MG 31270-901, Brazil
| | - Gustavo B Menezes
- Department of Morphology, Institute of Biological Sciences, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Avenida Antônio Carlos 6627, Pampulha, Belo Horizonte, MG 31270-901, Brazil
| | - Milene A Rachid
- Department of Pathology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Avenida Antônio Carlos 6627, Pampulha, Belo Horizonte, MG 31270-901, Brazil
| | - Antônio L Teixeira
- Interdisciplinary Laboratory of Medical Investigation, School of Medicine, Universidade Federal de Minas Gerais, Avenida Alfredo Balena 190, Santa Efigênia, Belo Horizonte, MG 30130-100, Brazil.
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20
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Kilpatrick S, Gow AG, Foale RD, Tappin SW, Carruthers H, Reed N, Yool DA, Woods S, Marques AI, Jalan R, Mellanby RJ. Plasma cytokine concentrations in dogs with a congenital portosystemic shunt. Vet J 2014; 200:197-9. [PMID: 24518641 DOI: 10.1016/j.tvjl.2014.01.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Revised: 01/09/2014] [Accepted: 01/11/2014] [Indexed: 12/12/2022]
Abstract
Congenital portosystemic shunts (cPSS) are a well-recognised vascular anomaly in dogs. Recent studies have shown an association between inflammation and hepatic encephalopathy (HE), which is a common clinical syndrome in dogs with a cPSS. Pro-inflammatory cytokines such as interleukin (IL)-6 and tumour necrosis factor (TNF)-α are frequently increased in the plasma of human patients with liver disease and have been implicated in the development of HE. In the current study, plasma concentrations of IL-2, IL-6, IL-8 and TNF-α were measured using a multiplex electrochemiluminescence immunoassay in 36 dogs with a cPSS and compared to 25 healthy dogs. There were no significant differences in plasma IL-2, IL-8 and TNF-α concentrations between the two groups; however, plasma concentrations of IL-6 were significantly higher in dogs with a cPSS compared to healthy dogs (P=0.02).
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Affiliation(s)
- Scott Kilpatrick
- Royal (Dick) School of Veterinary Studies, Division of Veterinary Clinical Sciences, Hospital for Small Animals, The University of Edinburgh, Midlothian EH25 9RG, United Kingdom
| | - Adam G Gow
- Royal (Dick) School of Veterinary Studies, Division of Veterinary Clinical Sciences, Hospital for Small Animals, The University of Edinburgh, Midlothian EH25 9RG, United Kingdom; Roslin Institute, Royal (Dick) School of Veterinary Studies, The University of Edinburgh, Midlothian EH25 9RG, United Kingdom
| | - Rob D Foale
- Dick White Referrals, Station Farm, London Road, Six Mile Bottom, Cambridgeshire CB8 0UH, United Kingdom
| | - Simon W Tappin
- Dick White Referrals, Station Farm, London Road, Six Mile Bottom, Cambridgeshire CB8 0UH, United Kingdom
| | | | - Nicola Reed
- Royal (Dick) School of Veterinary Studies, Division of Veterinary Clinical Sciences, Hospital for Small Animals, The University of Edinburgh, Midlothian EH25 9RG, United Kingdom
| | - Donald A Yool
- Royal (Dick) School of Veterinary Studies, Division of Veterinary Clinical Sciences, Hospital for Small Animals, The University of Edinburgh, Midlothian EH25 9RG, United Kingdom
| | - Samantha Woods
- Royal (Dick) School of Veterinary Studies, Division of Veterinary Clinical Sciences, Hospital for Small Animals, The University of Edinburgh, Midlothian EH25 9RG, United Kingdom
| | - Ana I Marques
- Royal (Dick) School of Veterinary Studies, Division of Veterinary Clinical Sciences, Hospital for Small Animals, The University of Edinburgh, Midlothian EH25 9RG, United Kingdom
| | - Rajiv Jalan
- UCL Institute of Hepatology, Royal Free Hospital, Upper Third Floor, UCL Medical School, Pond Street, London NW3 2QG, United Kingdom
| | - Richard J Mellanby
- Royal (Dick) School of Veterinary Studies, Division of Veterinary Clinical Sciences, Hospital for Small Animals, The University of Edinburgh, Midlothian EH25 9RG, United Kingdom; Roslin Institute, Royal (Dick) School of Veterinary Studies, The University of Edinburgh, Midlothian EH25 9RG, United Kingdom.
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21
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Beardsley PM, Hauser KF. Glial modulators as potential treatments of psychostimulant abuse. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2014; 69:1-69. [PMID: 24484974 DOI: 10.1016/b978-0-12-420118-7.00001-9] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Glia (including astrocytes, microglia, and oligodendrocytes), which constitute the majority of cells in the brain, have many of the same receptors as neurons, secrete neurotransmitters and neurotrophic and neuroinflammatory factors, control clearance of neurotransmitters from synaptic clefts, and are intimately involved in synaptic plasticity. Despite their prevalence and spectrum of functions, appreciation of their potential general importance has been elusive since their identification in the mid-1800s, and only relatively recently have they been gaining their due respect. This development of appreciation has been nurtured by the growing awareness that drugs of abuse, including the psychostimulants, affect glial activity, and glial activity, in turn, has been found to modulate the effects of the psychostimulants. This developing awareness has begun to illuminate novel pharmacotherapeutic targets for treating psychostimulant abuse, for which targeting more conventional neuronal targets has not yet resulted in a single, approved medication. In this chapter, we discuss the molecular pharmacology, physiology, and functional relationships that the glia have especially in the light in which they present themselves as targets for pharmacotherapeutics intended to treat psychostimulant abuse disorders. We then review a cross section of preclinical studies that have manipulated glial processes whose behavioral effects have been supportive of considering the glia as drug targets for psychostimulant-abuse medications. We then close with comments regarding the current clinical evaluation of relevant compounds for treating psychostimulant abuse, as well as the likelihood of future prospects.
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Affiliation(s)
| | - Kurt F Hauser
- Virginia Commonwealth University, Richmond, Virginia, USA
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22
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Luo M, Li L, Yang EN, Dai CY, Liang SR, Cao WK. Correlation between interleukin-6 and ammonia in patients with overt hepatic encephalopathy due to cirrhosis. Clin Res Hepatol Gastroenterol 2013; 37:384-90. [PMID: 23084463 DOI: 10.1016/j.clinre.2012.08.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2012] [Revised: 07/12/2012] [Accepted: 08/08/2012] [Indexed: 02/07/2023]
Abstract
OBJECTIVE Previous studies have shown that elevated serum levels of interleukin-6 (IL-6) correlate with the severity of overt hepatic encephalopathy (OHE) in cirrhotic patients. However, the correlation between serum IL-6 levels and plasma ammonia levels in these patients remains unclear. Therefore, the present study investigated this correlation between both variables in cirrhotic patients with OHE. METHODS Fifty-five cirrhotic patients with various grades of OHE, 29 cirrhotic patients without OHE, and 30 healthy controls were recruited. Concentrations of plasma ammonia and serum IL-6 were simultaneously measured. RESULTS In cirrhotic patients with OHE, the severity of OHE, represented by the West Haven criteria, correlated with serum IL-6 levels (r=0.43, P<0.05) and plasma ammonia levels (r=0.59, P<0.05). IL-6 and ammonia were found to be significant independent predictors of OHE severity (P<0.05 for both variables). Furthermore, the severity of liver cirrhosis, determined by Child-Pugh scores, correlated with serum IL-6 levels (r=0.45, P<0.05) and plasma ammonia levels (r=0.68, P<0.05) in these patients. Moreover, there was a significant positive correlation between serum IL-6 levels and plasma ammonia levels (r=0.58, P<0.05) in cirrhotic patients with OHE, but not in patients without OHE (r=0.42, P>0.05) or healthy controls (r=0.27, P>0.05). The correlation between IL-6 and ammonia was independent of infectious precipitating factors. CONCLUSIONS The results of the present study suggest that IL-6 might be involved in the mechanism by which ammonia contributes to the pathogenesis of OHE. There is also evidence of a potential synergistic interaction between proinflammatory cytokines and ammonia in the pathogenesis of OHE.
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Affiliation(s)
- Ming Luo
- Graduate School, Tianjin Medical University, No. 81 mailbox, 22, Qixiangtai Road, Heping District, 300070 Tianjin, China.
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Braissant O, McLin VA, Cudalbu C. Ammonia toxicity to the brain. J Inherit Metab Dis 2013; 36:595-612. [PMID: 23109059 DOI: 10.1007/s10545-012-9546-2] [Citation(s) in RCA: 181] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Revised: 09/19/2012] [Accepted: 09/25/2012] [Indexed: 12/21/2022]
Abstract
Hyperammonemia can be caused by various acquired or inherited disorders such as urea cycle defects. The brain is much more susceptible to the deleterious effects of ammonium in childhood than in adulthood. Hyperammonemia provokes irreversible damage to the developing central nervous system: cortical atrophy, ventricular enlargement and demyelination lead to cognitive impairment, seizures and cerebral palsy. The mechanisms leading to these severe brain lesions are still not well understood, but recent studies show that ammonium exposure alters several amino acid pathways and neurotransmitter systems, cerebral energy metabolism, nitric oxide synthesis, oxidative stress and signal transduction pathways. All in all, at the cellular level, these are associated with alterations in neuronal differentiation and patterns of cell death. Recent advances in imaging techniques are increasing our understanding of these processes through detailed in vivo longitudinal analysis of neurobiochemical changes associated with hyperammonemia. Further, several potential neuroprotective strategies have been put forward recently, including the use of NMDA receptor antagonists, nitric oxide inhibitors, creatine, acetyl-L-carnitine, CNTF or inhibitors of MAPKs and glutamine synthetase. Magnetic resonance imaging and spectroscopy will ultimately be a powerful tool to measure the effects of these neuroprotective approaches.
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Affiliation(s)
- Olivier Braissant
- Service of Biomedicine, Lausanne University Hospital, Avenue Pierre-Decker 2, CI 02/33, CH-1011 Lausanne, Switzerland.
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24
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Pathogenesis of hepatic encephalopathy. Gastroenterol Res Pract 2012; 2012:642108. [PMID: 23316223 PMCID: PMC3534214 DOI: 10.1155/2012/642108] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2012] [Revised: 11/16/2012] [Accepted: 11/16/2012] [Indexed: 02/06/2023] Open
Abstract
Hepatic encephalopathy can be a serious complication of acute liver failure and chronic liver diseases, predominantly liver cirrhosis. Hyperammonemia plays the most important role in the pathogenesis of hepatic encephalopathy. The brain-blood barrier disturbances, changes in neurotransmission, neuroinflammation, oxidative stress, GABA-ergic or benzodiazepine pathway abnormalities, manganese neurotoxicity, brain energetic disturbances, and brain blood flow abnormalities are considered to be involved in the development of hepatic encephalopathy. The influence of small intestine bacterial overgrowth (SIBO) on the induction of minimal hepatic encephalopathy is recently emphasized. The aim of this paper is to present the current views on the pathogenesis of hepatic encephalopathy.
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Luo M, Li L, Yang EN, Cao WK. Relationship between interleukin-6 and ammonia in patients with minimal hepatic encephalopathy due to liver cirrhosis. Hepatol Res 2012; 42:1202-10. [PMID: 22646055 DOI: 10.1111/j.1872-034x.2012.01047.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
AIM Previous studies have shown significantly elevated levels of interleukin (IL)-6 in cirrhotic patients with minimal hepatic encephalopathy (MHE), but the relationship between circulating levels of IL-6 and ammonia is unclear. The aim of this study is to investigate the relationship between both variables in cirrhotic patients with MHE. METHODS Psychometric tests including number connection test part A (NCT-A) and digit symbol test (DST) were performed to diagnose MHE in 85 cirrhotic patients. Simultaneously, circulating levels of IL-6 and ammonia were measured. RESULTS Thirty-two (37.6%) cirrhotic patients were diagnosed with MHE. IL-6 and ammonia were the independent predictors of the presence of MHE (P < 0.05 for both variables). Circulating levels of IL-6 and ammonia correlated with the severity of MHE represented by results of NCT-A (r = 0.56, P < 0.05 and r = 0.39, P < 0.05, respectively) and DST (r = -0.48, P < 0.05 and r = -0.47, P < 0.05, respectively). Moreover, there was a significant correlation between circulating levels of IL-6 and those of ammonia in patients with MHE (r = 0.61, P < 0.05), and a positive additive interaction was found between IL-6 and ammonia on the presence of MHE, with a significant synergy index of 1.51 (95% confidence interval = 1.12-3.46). CONCLUSION The present study demonstrates a significant correlation and a positive additive interaction between IL-6 and ammonia in cirrhotic patients with MHE, suggesting that IL-6 may have a potential synergistic relationship with ammonia in the induction of MHE.
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Affiliation(s)
- Ming Luo
- Graduate School, Tianjin Medical University Graduate School, Tianjin University of Traditional Chinese Medicine Tianjin Liver Disease Institute, Tianjin Infectious Disease Hospital, Tianjin, China
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da Silva MH, da Rosa EJF, de Carvalho NR, Dobrachinski F, da Rocha JBT, Mauriz JL, González-Gallego J, Soares FAA. Acute Brain Damage Induced by Acetaminophen in Mice: Effect of Diphenyl Diselenide on Oxidative Stress and Mitochondrial Dysfunction. Neurotox Res 2011; 21:334-44. [DOI: 10.1007/s12640-011-9288-1] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2011] [Revised: 10/21/2011] [Accepted: 10/31/2011] [Indexed: 12/13/2022]
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Rama Rao KV, Norenberg MD. Brain energy metabolism and mitochondrial dysfunction in acute and chronic hepatic encephalopathy. Neurochem Int 2011; 60:697-706. [PMID: 21989389 DOI: 10.1016/j.neuint.2011.09.007] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2011] [Revised: 09/16/2011] [Accepted: 09/20/2011] [Indexed: 12/22/2022]
Abstract
One proposed mechanism for acute and chronic hepatic encephalopathy (HE) is a disturbance in cerebral energy metabolism. It also reviews the current status of this mechanism in both acute and chronic HE, as well as in other hyperammonemic disorders. It also reviews abnormalities in glycolysis, lactate metabolism, citric acid cycle, and oxidative phosphorylation as well as associated energy impairment. Additionally, the role of mitochondrial permeability transition (mPT), a recently established factor in the pathogenesis of HE and hyperammonemia, is emphasized. Energy failure appears to be an important pathogenetic component of both acute and chronic HE and a potential target for therapy.
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Affiliation(s)
- Kakulavarapu V Rama Rao
- Department of Pathology, University of Miami Miller School of Medicine, Miami, FL 33125, United States
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