1
|
Cheyne I, Boryszewski B, Chang W, Mikaszewska-Sokolewicz M. A DNA Polymerase Subunit Gamma (POLG) Mutation Imposing a Difficult Differential Diagnosis of Hepatic Encephalopathy in a Newborn: A Case Report. Cureus 2024; 16:e65239. [PMID: 39184802 PMCID: PMC11342063 DOI: 10.7759/cureus.65239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/24/2024] [Indexed: 08/27/2024] Open
Abstract
Hepatic encephalopathy (HE) is a condition connected with neuropsychiatric alteration during hepatic failure. The differential diagnosis of HE is challenging due to overlapping symptoms with other conditions. Polymerase subunit gamma (POLG) is a mitochondrial gene, and an infant POLG mutation can manifest with severe and progressive hepatic failure and encephalopathy, imposing a difficult differential diagnosis due to similarities to other conditions. The lack of curative treatment leads to a poor prognosis. An 11-month-old boy was admitted to the intensive care unit (ICU) due to altered consciousness and increasing edema due to acute hepatic failure of unknown etiology. After extensive multidisciplinary discussions and a lack of response to treatment for more than three weeks, a mitochondrial disease was suspected, and a genetic test was taken. The patient's condition continued to deteriorate. The patient died on the 25th day of hospitalization in the ICU. After death, a genetic test confirmed a rare POLG mutation NM_002693.3(POLG):c.3104+2T>A (Variation ID: 422378 Accession: VCV000422378.8). We suggest that a screen test for POLG mutations be considered early in the diagnostic process and that clinicians consider mitochondrial genetic mutations, such as POLG mutations, more often. This article is the first to describe a patient with this specific mutation.
Collapse
Affiliation(s)
- Ithamar Cheyne
- Anesthesiology and Critical Care Scientific Circle English Division (ANKONA ED), Medical University of Warsaw, Warsaw, POL
| | - Bartosz Boryszewski
- Anesthesiology and Critical Care Scientific Circle English Division (ANKONA ED), Medical University of Warsaw, Warsaw, POL
| | - Wyven Chang
- Anesthesiology and Critical Care Scientific Circle English Division (ANKONA ED), Medical University of Warsaw, Warsaw, POL
| | | |
Collapse
|
2
|
Llansola M, Arenas YM, Sancho-Alonso M, Mincheva G, Palomares-Rodriguez A, Doverskog M, Izquierdo-Altarejos P, Felipo V. Neuroinflammation alters GABAergic neurotransmission in hyperammonemia and hepatic encephalopathy, leading to motor incoordination. Mechanisms and therapeutic implications. Front Pharmacol 2024; 15:1358323. [PMID: 38560359 PMCID: PMC10978603 DOI: 10.3389/fphar.2024.1358323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 02/29/2024] [Indexed: 04/04/2024] Open
Abstract
Enhanced GABAergic neurotransmission contributes to impairment of motor coordination and gait and of cognitive function in different pathologies, including hyperammonemia and hepatic encephalopathy. Neuroinflammation is a main contributor to enhancement of GABAergic neurotransmission through increased activation of different pathways. For example, enhanced activation of the TNFα-TNFR1-NF-κB-glutaminase-GAT3 pathway and the TNFα-TNFR1-S1PR2-CCL2-BDNF-TrkB pathway in cerebellum of hyperammonemic rats enhances GABAergic neurotransmission. This is mediated by mechanisms affecting GABA synthesizing enzymes GAD67 and GAD65, total and extracellular GABA levels, membrane expression of GABAA receptor subunits, of GABA transporters GAT1 and GAT three and of chloride co-transporters. Reducing neuroinflammation reverses these changes, normalizes GABAergic neurotransmission and restores motor coordination. There is an interplay between GABAergic neurotransmission and neuroinflammation, which modulate each other and altogether modulate motor coordination and cognitive function. In this way, neuroinflammation may be also reduced by reducing GABAergic neurotransmission, which may also improve cognitive and motor function in pathologies associated to neuroinflammation and enhanced GABAergic neurotransmission such as hyperammonemia, hepatic encephalopathy or Parkinson's disease. This provides therapeutic targets that may be modulated to improve cognitive and motor function and other alterations such as fatigue in a wide range of pathologies. As a proof of concept it has been shown that antagonists of GABAA receptors such as bicuculline reduces neuroinflammation and improves cognitive and motor function impairment in rat models of hyperammonemia and hepatic encephalopathy. Antagonists of GABAA receptors are not ideal therapeutic tools because they can induce secondary effects. As a more effective treatment to reduce GABAergic neurotransmission new compounds modulating it by other mechanisms are being developed. Golexanolone reduces GABAergic neurotransmission by reducing the potentiation of GABAA receptor activation by neurosteroids such as allopregnanolone. Golexanolone reduces neuroinflammation and GABAergic neurotransmission in animal models of hyperammonemia, hepatic encephalopathy and cholestasis and this is associated with improvement of fatigue, cognitive impairment and motor incoordination. This type of compounds may be useful therapeutic tools to improve cognitive and motor function in different pathologies associated with neuroinflammation and increased GABAergic neurotransmission.
Collapse
Affiliation(s)
- Marta Llansola
- Laboratory of Neurobiology, Centro de Investigación Príncipe Felipe, Valencia, Spain
| | - Yaiza M. Arenas
- Laboratory of Neurobiology, Centro de Investigación Príncipe Felipe, Valencia, Spain
| | - María Sancho-Alonso
- Laboratory of Neurobiology, Centro de Investigación Príncipe Felipe, Valencia, Spain
| | - Gergana Mincheva
- Laboratory of Neurobiology, Centro de Investigación Príncipe Felipe, Valencia, Spain
| | | | | | | | - Vicente Felipo
- Laboratory of Neurobiology, Centro de Investigación Príncipe Felipe, Valencia, Spain
| |
Collapse
|
3
|
Edwards TM, Puglis HJ, Kent DB, Durán JL, Bradshaw LM, Farag AM. Ammonia and aquatic ecosystems - A review of global sources, biogeochemical cycling, and effects on fish. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 907:167911. [PMID: 37871823 DOI: 10.1016/j.scitotenv.2023.167911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 09/27/2023] [Accepted: 10/16/2023] [Indexed: 10/25/2023]
Abstract
The purpose of this review is to better understand the full life cycle and influence of ammonia from an aquatic biology perspective. While ammonia has toxic properties in water and air, it also plays a central role in the biogeochemical nitrogen (N) cycle and regulates mechanisms of normal and abnormal fish physiology. Additionally, as the second most synthesized chemical on Earth, ammonia contributes economic value to many sectors, particularly fertilizers, energy storage, explosives, refrigerants, and plastics. But, with so many uses, industrial N2-fixation effectively doubles natural reactive N concentrations in the environment. The consequence is global, with excess fixed nitrogen driving degradation of soils, water, and air; intensifying eutrophication, biodiversity loss, and climate change; and creating health risks for humans, wildlife, and fisheries. Thus, the need for ammonia research in aquatic systems is growing. In response, we prepared this review to better understand the complexities and connectedness of environmental ammonia. Even the term "ammonia" has multiple meanings. So, we have clarified the nomenclature, identified units of measurement, and summarized methods to measure ammonia in water. We then discuss ammonia in the context of the N-cycle, review its role in fish physiology and mechanisms of toxicity, and integrate the effects of human N-fixation, which continuously expands ammonia's sources and uses. Ammonia is being developed as a carbon-free energy carrier with potential to increase reactive nitrogen in the environment. With this in mind, we review the global impacts of excess reactive nitrogen and consider the current monitoring and regulatory frameworks for ammonia. The presented synthesis illustrates the complex and interactive dynamics of ammonia as a plant nutrient, energy molecule, feedstock, waste product, contaminant, N-cycle participant, regulator of animal physiology, toxicant, and agent of environmental change. Few molecules are as influential as ammonia in the management and resilience of Earth's resources.
Collapse
Affiliation(s)
- Thea M Edwards
- U.S. Geological Survey, Columbia Environmental Research Center, Columbia, MO 65201, USA.
| | - Holly J Puglis
- U.S. Geological Survey, Columbia Environmental Research Center, Columbia, MO 65201, USA
| | - Douglas B Kent
- U.S. Geological Survey, Earth Systems Processes Division, Menlo Park, CA, USA
| | - Jonathan López Durán
- U.S. Geological Survey, Columbia Environmental Research Center, Columbia, MO 65201, USA
| | - Lillian M Bradshaw
- U.S. Geological Survey, Columbia Environmental Research Center, Columbia, MO 65201, USA
| | - Aïda M Farag
- U.S. Geological Survey, Columbia Environmental Research Center, Jackson Field Research Station, Jackson, WY, USA
| |
Collapse
|
4
|
Guo H, Wang G, Huang W, Li L, Bai Y, Wang H, Gao L. The Mechanism of Hepatic Encephalopathy Induced by Thioacetamide Based on Metabolomics and Proteomics: A Preliminary Study. Int J Mol Sci 2023; 25:284. [PMID: 38203455 PMCID: PMC10779174 DOI: 10.3390/ijms25010284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 12/15/2023] [Accepted: 12/20/2023] [Indexed: 01/12/2024] Open
Abstract
Hepatic encephalopathy (HE) is a central nervous system dysfunction syndrome caused by acute and chronic liver failure or various portal systemic shunt disorders. HE arises from metabolic disorder and excludes other known types of encephalopathy. HE is a major cause of death in people with liver disease. Early diagnosis and timely treatment are key to improving HE prognosis. Herein, we established a model of HE and performed metabolomics to identify 50 significantly differential metabolites between the HE group and control group. The main metabolic pathways associated with these differential metabolites were the purine metabolism, pyrimidine metabolism, aminoacyl tRNA biosynthesis, and glucose metabolism. Through proteomics analysis, we identified 226 significantly differential proteins (52 up-regulated and 174 down-regulated). The main (Kyoto Encyclopedia of Genes and Genomes) enrichment pathways were the Staphylococcus aureus infection, vitamin digestion and absorption, and complement and coagulation cascades. Through the conjoint analysis of proteomics and metabolomics, the differentially present proteins and metabolites were found to be involved in vitamin digestion and absorption, and ferroptosis pathways. In HE, malondialdehyde was significantly elevated, but glutathione was significantly diminished, and the redox balance was destroyed, thus leading to changes in proteins' levels associated with the ferroptosis pathway. In conclusion, this study preliminarily explored the molecular and metabolic mechanisms underlying HE.
Collapse
Affiliation(s)
- Honghui Guo
- Liaoning Province Key Laboratory of Forensic Bio-Evidence Sciences, Shenyang 110122, China; (H.G.); (W.H.)
- China Medical University Center of Forensic Investigation, Shenyang 110122, China
- Department of Forensic Analytical Toxicology, China Medical University, Shenyang 110122, China
| | - Guang Wang
- Department of Laboratory Animal Science, China Medical University, Shenyang 110122, China;
| | - Wei Huang
- Liaoning Province Key Laboratory of Forensic Bio-Evidence Sciences, Shenyang 110122, China; (H.G.); (W.H.)
- China Medical University Center of Forensic Investigation, Shenyang 110122, China
- Department of Forensic Analytical Toxicology, China Medical University, Shenyang 110122, China
| | - Lingrui Li
- Liaoning Province Key Laboratory of Forensic Bio-Evidence Sciences, Shenyang 110122, China; (H.G.); (W.H.)
- China Medical University Center of Forensic Investigation, Shenyang 110122, China
- Department of Forensic Analytical Toxicology, China Medical University, Shenyang 110122, China
| | - Yang Bai
- Liaoning Province Key Laboratory of Forensic Bio-Evidence Sciences, Shenyang 110122, China; (H.G.); (W.H.)
- China Medical University Center of Forensic Investigation, Shenyang 110122, China
- Department of Forensic Analytical Toxicology, China Medical University, Shenyang 110122, China
| | - Haifeng Wang
- Liaoning Province Key Laboratory of Forensic Bio-Evidence Sciences, Shenyang 110122, China; (H.G.); (W.H.)
- China Medical University Center of Forensic Investigation, Shenyang 110122, China
- Department of Forensic Analytical Toxicology, China Medical University, Shenyang 110122, China
| | - Lina Gao
- Liaoning Province Key Laboratory of Forensic Bio-Evidence Sciences, Shenyang 110122, China; (H.G.); (W.H.)
- China Medical University Center of Forensic Investigation, Shenyang 110122, China
- Department of Forensic Analytical Toxicology, China Medical University, Shenyang 110122, China
| |
Collapse
|
5
|
Bäckström T, Turkmen S, Das R, Doverskog M, Blackburn TP. The GABA system, a new target for medications against cognitive impairment-Associated with neuroactive steroids. J Intern Med 2023; 294:281-294. [PMID: 37518841 DOI: 10.1111/joim.13705] [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] [Indexed: 08/01/2023]
Abstract
The prevalence of cognitive dysfunction, dementia, and neurodegenerative disorders such as Alzheimer's disease (AD) is increasing in parallel with an aging population. Distinct types of chronic stress are thought to be instrumental in the development of cognitive impairment in central nervous system (CNS) disorders where cognitive impairment is a major unmet medical need. Increased GABAergic tone is a mediator of stress effects but is also a result of other factors in CNS disorders. Positive GABA-A receptor modulating stress and sex steroids (steroid-PAMs) such as allopregnanolone (ALLO) and medroxyprogesterone acetate can provoke impaired cognition. As such, ALLO impairs memory and learning in both animals and humans. In transgenic AD animal studies, continuous exposure to ALLO at physiological levels impairs cognition and increases degenerative AD pathology, whereas intermittent ALLO injections enhance cognition, indicating pleiotropic functions of ALLO. We have shown that GABA-A receptor modulating steroid antagonists (GAMSAs) can block the acute negative cognitive impairment of ALLO on memory in animal studies and in patients with cognitive impairment due to hepatic encephalopathy. Here we describe disorders affected by steroid-PAMs and opportunities to treat these adverse effects of steroid-PAMs with novel GAMSAs.
Collapse
Affiliation(s)
| | - Sahruh Turkmen
- Department of Clinical Sciences, University of Umeå, Umeå, Sweden
| | - Roshni Das
- Department of Clinical Sciences, University of Umeå, Umeå, Sweden
- Umecrine Cognition AB, Solna, Sweden
| | | | | |
Collapse
|
6
|
Kinetic modeling of gamma-aminobutyric acid production by Lactobacillus brevis based on pH-dependent model and rolling correction. Chin J Chem Eng 2022. [DOI: 10.1016/j.cjche.2022.05.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
7
|
S100 Beta Protein as a Marker of Hepatic Encephalopathy: A Breakthrough in Diagnostics or a False Trail? Review of the Literature. POSTEP HIG MED DOSW 2022. [DOI: 10.2478/ahem-2022-0018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
Hepatic encephalopathy is a dysfunction of the central nervous system caused by chronic and acute liver disease. The dysfunction presents a wide spectrum of symptoms—from the undetectable in a standard clinical examination to hepatic coma—and could be caused by both chronic and acute liver diseases. For many years research has been conducted to find a marker that would allow for the accurate, quick, and possibly inexpensive detection of hepatic encephalopathy. Due to the pathogenesis of hepatic encephalopathy, researchers’ attention is focused on markers of damage to the central nervous system. One of the markers of astrocyte damage, known from research in neurology and neurosurgery, is the protein S100B. Published research results so far are inconclusive, but they allow us to look with optimism at the role of S100B as a marker of minimal hepatic encephalopathy (MHE).
Collapse
|
8
|
Bäckström T, Das R, Bixo M. Positive GABA A receptor modulating steroids and their antagonists: Implications for clinical treatments. J Neuroendocrinol 2022; 34:e13013. [PMID: 34337790 DOI: 10.1111/jne.13013] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 07/09/2021] [Accepted: 07/09/2021] [Indexed: 01/02/2023]
Abstract
GABA is the main inhibitory neurotransmitter in the brain and GABAergic transmission has been shown to be of importance for regulation of mood, memory and food intake. The progesterone metabolite allopregnanolone (Allo) is a positive GABAA receptor modulating steroid with potent effects. In humans, disorders such as premenstrual dysphoric disorder (PMDD), hepatic encephalopathy and polycystic ovarian syndrome are associated with elevated Allo levels and increased negative mood, disturbed memory and increased food intake in some individuals. This is surprising because Allo shares many properties with benzodiazepines and is mainly considered to be anxiolytic and anti-depressant. However, it is well established that, in certain individuals, GABAA receptor activating compounds could have paradoxical effects and thus be anxiogenic in low physiological plasma concentrations but anxiolytic at high levels. We have demonstrated that isoallopregnanolone (Isoallo), the 3β-OH sibling of Allo, functions as a GABAA receptor modulating steroid antagonist (GAMSA) but without any effects of its own on GABAA receptors. The antagonistic effect is noted in most GABAA subtypes investigated in vitro to date. In vivo, Isoallo can inhibit Allo-induced anaesthesia in rats, as well as sedation or saccadic eye velocity in humans. Isoallo treatment has been studied in women with PMDD. In a first phase II study, Isoallo (Sepranolone; Asarina Pharma) injections significantly ameliorated negative mood in women with PMDD compared with placebo. Several GAMSAs for oral administration have also been developed. The GAMSA, UC1011, can inhibit Allo induced memory disturbances in rats and an oral GAMSA, GR3027, has been shown to restore learning and motor coordination in rats with hepatic encephalopathy. In humans, vigilance, cognition and pathological electroencephalogram were improved in patients with hepatic encephalopathy on treatment with GR3027. In conclusion GAMSAs are a new possible treatment for disorders and symptoms caused by hyperactivity in the GABAA system.
Collapse
Affiliation(s)
- Torbjörn Bäckström
- Department of Clinical Sciences, Obstetrics and Gynecology, Umeå University, Umea, Sweden
| | - Roshni Das
- Department of Integrative Medical Biology, Umeå University, Umea, Sweden
| | - Marie Bixo
- Department of Clinical Sciences, Obstetrics and Gynecology, Umeå University, Umea, Sweden
| |
Collapse
|
9
|
Neurosteroid Activation of GABA-A Receptors: A Potential Treatment Target for Symptoms in Primary Biliary Cholangitis? Can J Gastroenterol Hepatol 2022; 2022:3618090. [PMID: 36523650 PMCID: PMC9747297 DOI: 10.1155/2022/3618090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 11/07/2022] [Accepted: 11/09/2022] [Indexed: 12/12/2022] Open
Abstract
Background and Aims A third of patients with primary biliary cholangitis (PBC) experience poorly understood cognitive symptoms, with a significant impact on quality of life (QOL), and no effective medical treatment. Allopregnanolone, a neurosteroid, is a positive allosteric modulator of gamma-aminobutyricacid-A (GABA-A) receptors, associated with disordered mood, cognition, and memory. This study explored associations between allopregnanolone and a disease-specific QOL scoring system (PBC-40) in PBC patients. Method Serum allopregnanolone levels were measured in 120 phenotyped PBC patients and 40 age and gender-matched healthy controls. PBC subjects completed the PBC-40 at recruitment. Serum allopregnanolone levels were compared across PBC-40 domains for those with none/mild symptoms versus severe symptoms. Results There were no overall differences in allopregnanolone levels between healthy controls (median = 0.03 ng/ml (IQR = 0.025)) and PBC patients (0.031 (0.42), p = 0.42). Within the PBC cohort, higher allopregnanolone levels were observed in younger patients (r (120) = -0.53, p < 0.001) but not healthy controls (r (39) = -0.21, p = 0.21). Allopregnanolone levels were elevated in the PBC-40 domains, cognition (u = 1034, p = 0.02), emotional (u = 1374, p = 0.004), and itch (u = 795, p = 0.03). Severe cognitive symptoms associated with a younger age: severe (50 (12)) vs. none (60 (13); u = 423 p = 0.001). Conclusion Elevated serum allopregnanolone is associated with severe cognitive, emotional, and itch symptoms in PBC, in keeping with its known action on GABA-A receptors. Existing novel compounds targeting allopregnanolone could offer new therapies in severely symptomatic PBC, satisfying a significant unmet need.
Collapse
|
10
|
Fernández-Torre JL, Kaplan PW. Triphasic Waves: Historical Overview of an Unresolved Mystery. J Clin Neurophysiol 2021; 38:399-409. [PMID: 34155180 DOI: 10.1097/wnp.0000000000000809] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
SUMMARY Triphasic waves are a fascinating and mysterious EEG feature. We now have to accept that, at times, epileptiform discharges may have a blunted "triphasic morphology," and that there may be great difficulty in distinguishing between these often similar forms. The aim of this review was to describe the evolution in our understanding of triphasic waves that has occurred regarding the pathophysiology of triphasic waves, their most frequent causes, and the diagnostic difficulties involved in interpretation and differentiation from nonconvulsive status epilepticus.
Collapse
Affiliation(s)
- José L Fernández-Torre
- Clinical Neurophysiology Department, Marqués de Valdecilla University Hospital, Santander, Cantabria, Spain
- Biomedical Research Institute (IDIVAL), Santander, Cantabria, Spain; and
| | - Peter W Kaplan
- Department of Neurology, Johns Hopkins Bayview Medical Center, Baltimore, Maryland, U.S.A
| |
Collapse
|
11
|
Madsen M, Kimer N, Bendtsen F, Petersen AM. Fecal microbiota transplantation in hepatic encephalopathy: a systematic review. Scand J Gastroenterol 2021; 56:560-569. [PMID: 33840331 DOI: 10.1080/00365521.2021.1899277] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Hepatic encephalopathy (HE) is a reversible neurocognitive dysfunction that ranges in severity from subclinical alterations to coma. Patients with chronic liver disease are predisposed to HE due to metabolic failure and portosystemic shunting of toxins, of which ammonia is believed to be the main toxic chemical. Fecal microbiota transplantation (FMT) may reduce ammonia synthesis by altering the gut microbiota composition to a taxon low in urease, diminish uptake of ammonia by reestablishing the integrity of the intestinal barrier and increase ammonia clearance by improving liver function. In this systematic review, we summarize the insights of the current literature examining FMT as a treatment for HE.PubMed and EMBASE were searched on 08 February 2021 using the MeSH terms 'fecal microbiota transplantation & hepatic encephalopathy' and the abbreviations 'FMT & HE'.Eight studies fulfilled our inclusion criteria, comprising two randomized clinical trials, three case reports and three rodent studies. Thirty-nine patients with HE were treated with FMT. Thirty-nine rodents received FMT in laboratory tests. FMT improved neurocognitive test results in four human studies and two rodent studies. Microbiota originating from donors was found in human recipients one year post-FMT. Readmission of patients was lower after treatment with FMT compared to standard of care.FMT may improve neurocognitive function and reduce serious adverse events in patients with HE, but the studies conducted so far have been small and their long-term follow-up is limited. Large-scale, randomized and controlled trials are needed to validate and help standardize the clinical application of FMT in cases of HE.
Collapse
Affiliation(s)
- Mathias Madsen
- Gastro Unit, Medical Division, Hvidovre University Hospital, Copenhagen, Denmark
| | - Nina Kimer
- Gastro Unit, Medical Division, Hvidovre University Hospital, Copenhagen, Denmark.,Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Flemming Bendtsen
- Gastro Unit, Medical Division, Hvidovre University Hospital, Copenhagen, Denmark
| | - Andreas Munk Petersen
- Gastro Unit, Medical Division, Hvidovre University Hospital, Copenhagen, Denmark.,Department of Clinical Microbiology, Hvidovre University Hospital, Copenhagen, Denmark
| |
Collapse
|
12
|
Balzano T, Dadsetan S, Forteza J, Cabrera-Pastor A, Taoro-Gonzalez L, Malaguarnera M, Gil-Perotin S, Cubas-Nuñez L, Casanova B, Castro-Quintas A, Ponce-Mora A, Arenas YM, Leone P, Erceg S, Llansola M, Felipo V. Chronic hyperammonemia induces peripheral inflammation that leads to cognitive impairment in rats: Reversed by anti-TNF-α treatment. J Hepatol 2020; 73:582-592. [PMID: 30654069 DOI: 10.1016/j.jhep.2019.01.008] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 01/03/2019] [Accepted: 01/04/2019] [Indexed: 01/04/2023]
Abstract
BACKGROUND & AIMS Chronic hyperammonemia induces neuroinflammation which mediates cognitive impairment. How hyperammonemia induces neuroinflammation remains unclear. We aimed to assess whether: chronic hyperammonemia induces peripheral inflammation, and whether this then contributes to neuroinflammation, altered neurotransmission and impaired spatial learning - before assessing whether this neuroinflammation and impairment is reversible following hyperammonemia elimination or treatment of peripheral inflammation with anti-TNF-α. METHODS Chronic hyperammonemia was induced by feeding rats an ammonia-containing diet. Peripheral inflammation was analyzed by measuring PGE2, TNF-α, IL-6 and IL-10. We tested whether chronic anti-TNF-α treatment improves peripheral inflammation, neuroinflammation, membrane expression of glutamate receptors in the hippocampus and spatial learning. RESULTS Hyperammonemic rats show a rapid and reversible induction of peripheral inflammation, with increased pro-inflammatory PGE2, TNF-α and IL-6, followed at around 10 days by reduced anti-inflammatory IL-10. Peripheral anti-TNF-α treatment prevents peripheral inflammation induction and the increase in IL-1b and TNF-α and microglia activation in hippocampus of the rats, which remain hyperammonemic. This is associated with prevention of the altered membrane expression of glutamate receptors and of the impairment of spatial memory assessed in the radial and Morris water mazes. CONCLUSIONS This report unveils a new mechanism by which chronic hyperammonemia induces neurological alterations: induction of peripheral inflammation. This suggests that reducing peripheral inflammation by safe procedures would improve cognitive function in patients with minimal hepatic encephalopathy. LAY SUMMARY This article unveils a new mechanism by which chronic hyperammonemia induces cognitive impairment in rats: chronic hyperammonemia per se induces peripheral inflammation, which mediates many of its effects on the brain, including induction of neuroinflammation, which alters neurotransmission, leading to cognitive impairment. It is also shown that reducing peripheral inflammation by treating rats with anti-TNF-α, which does not cross the blood-brain barrier, prevents hyperammonemia-induced neuroinflammation, alterations in neurotransmission and cognitive impairment.
Collapse
Affiliation(s)
- Tiziano Balzano
- Laboratory of Neurobiology, Centro Investigación Príncipe Felipe, Valencia, Spain
| | - Sherry Dadsetan
- Laboratory of Neurobiology, Centro Investigación Príncipe Felipe, Valencia, Spain
| | - Jerónimo Forteza
- Instituto Valenciano de Patología, Unidad Mixta de Patología Molecular, Centro Investigación Príncipe Felipe/Universidad Católica de Valencia Valencia, Spain
| | | | - Lucas Taoro-Gonzalez
- Laboratory of Neurobiology, Centro Investigación Príncipe Felipe, Valencia, Spain
| | - Michele Malaguarnera
- Laboratory of Neurobiology, Centro Investigación Príncipe Felipe, Valencia, Spain
| | - Sara Gil-Perotin
- Multiple Sclerosis and Neuroimmunology Research Group, Fundación para la Investigación La Fe, Valencia, Spain; Neurology Department, Hospital Universitario y Politécnico La Fe, 46026, Valencia, Spain
| | - Laura Cubas-Nuñez
- Multiple Sclerosis and Neuroimmunology Research Group, Fundación para la Investigación La Fe, Valencia, Spain
| | - Bonaventura Casanova
- Multiple Sclerosis and Neuroimmunology Research Group, Fundación para la Investigación La Fe, Valencia, Spain; Neurology Department, Hospital Universitario y Politécnico La Fe, 46026, Valencia, Spain
| | | | - Alejandro Ponce-Mora
- Laboratory of Neurobiology, Centro Investigación Príncipe Felipe, Valencia, Spain
| | - Yaiza M Arenas
- Laboratory of Neurobiology, Centro Investigación Príncipe Felipe, Valencia, Spain
| | - Paola Leone
- Laboratory of Neurobiology, Centro Investigación Príncipe Felipe, Valencia, Spain
| | - Slaven Erceg
- Stem Cells Therapies in Neurodegenerative Diseases Lab, Centro Investigación Príncipe Felipe, Valencia, Spain; National Stem Cell Bank-Valencia Node, Platform for Proteomics, Genotyping and Cell Lines, PRB3, ISCIII, Centro Investigación Príncipe Felipe, Valencia, Spain
| | - Marta Llansola
- Laboratory of Neurobiology, Centro Investigación Príncipe Felipe, Valencia, Spain
| | - Vicente Felipo
- Laboratory of Neurobiology, Centro Investigación Príncipe Felipe, Valencia, Spain.
| |
Collapse
|
13
|
Opoku YK, Liu Z, Afrifa J, Kumi AK, Liu H, Ghartey-Kwansah G, Koranteng H, Jiang X, Ren G, Li D. Fibroblast Growth Factor-21 ameliorates hepatic encephalopathy by activating the STAT3-SOCS3 pathway to inhibit activated hepatic stellate cells. EXCLI JOURNAL 2020; 19:567-581. [PMID: 32483404 PMCID: PMC7257252 DOI: 10.17179/excli2020-1287] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 04/27/2020] [Indexed: 12/12/2022]
Abstract
Neurological dysfunction, one of the consequences of acute liver failure (ALF), and also referred to as hepatic encephalopathy (HE), contributes to mortality posing challenges for clinical management. FGF21 has been implicated in the inhibition of cognitive decline and fibrogenesis. However, the effects of FGF21 on the clinical and molecular presentations of HE has not been elucidated. HE was induced by fulminant hepatic failure using thioacetamide (TAA) in male C57BL/6J mice while controls were injected with saline. For two consecutive weeks, mice were treated intraperitoneally with FGF21 (3 mg/kg) while controls were treated with saline. Cognitive, neurological, and activity function scores were recorded. Serum, liver, and brain samples were taken for analysis of CCL5 and GABA by ELISA, and RT qPCR was used to measure the expressions of fibrotic and pro-inflammatory markers. We report significant improvement in both cognitive and neurological scores by FGF21 treatment after impairment by TAA. GABA and CCL5, key factors in the progression of HE were also significantly reduced in the treatment group. Furthermore, the expression of fibrotic markers such as TGFβ and Col1 were also significantly downregulated after FGF21 treatment. TNFα and IL-6 were significantly reduced in the liver while in the brain, TNFα and IL-1 were downregulated. However, both in the liver and the brain, IL-10 was significantly upregulated. FGF21 inhibits CXCR4/CCL5 activation and upregulates the production of IL-10 in the damaged liver stimulating the production pro-inflammatory cytokines and apoptosis of hepatic stellate cells through the STAT3-SOCS3 pathway terminating the underlying fibrosis in HE.
Collapse
Affiliation(s)
- Yeboah Kwaku Opoku
- Department of Biology Education, Faculty of Science Education, University of Education, Winneba, Ghana.,Bio-pharmaceutical Laboratory, College of Life Sciences, Northeast Agricultural University, Harbin 150030, China
| | - Zhihang Liu
- Bio-pharmaceutical Laboratory, College of Life Sciences, Northeast Agricultural University, Harbin 150030, China
| | - Justice Afrifa
- Department of Medical Laboratory Science, University of Cape Coast, Cape Coast, Ghana.,Scientific Research Center, Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Asare Kwame Kumi
- Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Japan.,Department of Biomedical Sciences, University of Cape Coast, Ghana
| | - Han Liu
- Bio-pharmaceutical Laboratory, College of Life Sciences, Northeast Agricultural University, Harbin 150030, China
| | | | - Harriet Koranteng
- Jiamusi University No. 148, Xuefu Road, Jiamusi, Heilongjiang, China
| | - Xinghao Jiang
- Bio-pharmaceutical Laboratory, College of Life Sciences, Northeast Agricultural University, Harbin 150030, China
| | - Guiping Ren
- Bio-pharmaceutical Laboratory, College of Life Sciences, Northeast Agricultural University, Harbin 150030, China
| | - Deshan Li
- Bio-pharmaceutical Laboratory, College of Life Sciences, Northeast Agricultural University, Harbin 150030, China
| |
Collapse
|
14
|
Abstract
Despite widespread use of lactulose and rifaximin for the treatment of hepatic encephalopathy, this complication of advanced liver disease remains a major burden on the health care system in the United States and continues to predispose to high morbidity and mortality. Several agents have surfaced over recent years with promise to treat hepatic encephalopathy and mitigate the cognitive impairment associated with this disease process. The purpose of this article is to highlight the leading emerging therapies in hepatic encephalopathy as well as their therapeutic targets.
Collapse
|
15
|
GABA-A receptor modulating steroids in acute and chronic stress; relevance for cognition and dementia? Neurobiol Stress 2019; 12:100206. [PMID: 31921942 PMCID: PMC6948369 DOI: 10.1016/j.ynstr.2019.100206] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 11/13/2019] [Accepted: 12/18/2019] [Indexed: 01/10/2023] Open
Abstract
Cognitive dysfunction, dementia and Alzheimer's disease (AD) are increasing as the population worldwide ages. Therapeutics for these conditions is an unmet need. This review focuses on the role of the positive GABA-A receptor modulating steroid allopregnanolone (APα), it's role in underlying mechanisms for impaired cognition and of AD, and to determine options for therapy of AD. On one hand, APα given intermittently promotes neurogenesis, decreases AD-related pathology and improves cognition. On the other, continuous exposure of APα impairs cognition and deteriorates AD pathology. The disparity between these two outcomes led our groups to analyze the mechanisms underlying the difference. We conclude that the effects of APα depend on administration pattern and that chronic slightly increased APα exposure is harmful to cognitive function and worsens AD pathology whereas single administrations with longer intervals improve cognition and decrease AD pathology. These collaborative assessments provide insights for the therapeutic development of APα and APα antagonists for AD and provide a model for cross laboratory collaborations aimed at generating translatable data for human clinical trials.
Collapse
|
16
|
Bajaj JS, O’Leary JG, Tandon P, Wong F, Kamath PS, Biggins SW, Garcia-Tsao G, Lai J, Fallon MB, Thuluvath PJ, Vargas HE, Maliakkal B, Subramanian RM, Thacker LR, Reddy KR. Targets to improve quality of care for patients with hepatic encephalopathy: data from a multi-centre cohort. Aliment Pharmacol Ther 2019; 49:1518-1527. [PMID: 31032966 PMCID: PMC6538445 DOI: 10.1111/apt.15265] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Revised: 02/14/2019] [Accepted: 03/24/2019] [Indexed: 12/12/2022]
Abstract
BACKGROUND Hepatic encephalopathy (HE) can adversely affect outcomes in both in-patients and out-patients with cirrhosis. AIM To define targets for improving quality of care in HE management in the multi-centre North American Consortium for End-Stage Liver Disease (NACSELD) cohort. METHOD NACSELD in-patient cohort was analysed for (a) medication-associated precipitants, (b) aspiration pneumonia development, (c) HE medication changes, and (d) 90-day HE recurrence/readmissions. Comparisons were made between patients on no-therapy, lactulose only, rifaximin only or both. Ninety-day HE-readmission analysis was adjusted for MELD score. RESULTS Two thousand eight hundred and ten patients (1102 no-therapy, 659 lactulose, 154 rifaximin, 859 both) were included. HE on admission, and HE rates during hospitalisation were highest in those on lactulose only or dual therapy compared to no-therapy or rifaximin only (P < 0.001). Medications were the most prevalent precipitants (32%; 21% lactulose over/underuse, 5% benzodiazepines, 4% opioids, 1% rifaximin underuse, 1% hypnotics). Patients with medication-associated precipitants had a better prognosis compared to other precipitants. A total of 23% (n = 217) reached grade 3/4 HE, of which 16% developed HE-related aspiration pneumonia. Two thousand four hundred and twenty patients were discharged alive without liver transplant (790 no-therapy, 639 lactulose, 136 rifaximin, 855 both); 12.5% (n = 99) of no-therapy patients did not receive a discharge HE therapy renewal. Ninety-day HE-related readmissions were seen in 16% of patients (9% no-therapy, 9% rifaximin only, lactulose only 18%, dual 21%, <0.001), which persisted despite MELD adjustment (P = 0.009). CONCLUSION Several targets to improve HE management were identified in a large cohort of hospitalised cirrhotic patients. Interventions to decrease medication-precipitated HE, prevention of aspiration pneumonia, and optimisation of HE medications are warranted.
Collapse
Affiliation(s)
- Jasmohan S Bajaj
- Virginia Commonwealth University and McGuire VA Medical Center, Richmond, VA, USA
| | | | | | | | | | - Scott W Biggins
- University of Washington, Seattle, WA, USA and University of Denver, Colorado, CO, USA
| | | | - Jennifer Lai
- University of California, San Francisco, CA, USA
| | - Michael B Fallon
- University of Arizona, Phoenix, AZ, USA and University of Texas, Houston, TX, USA
| | | | | | - Benedict Maliakkal
- University of Tennessee, Memphis, TN and University of Rochester, Rochester, NY, USA
| | | | - Leroy R Thacker
- Virginia Commonwealth University and McGuire VA Medical Center, Richmond, VA, USA
| | | |
Collapse
|
17
|
Cudalbu C, Taylor-Robinson SD. Brain Edema in Chronic Hepatic Encephalopathy. J Clin Exp Hepatol 2019; 9:362-382. [PMID: 31360029 PMCID: PMC6637228 DOI: 10.1016/j.jceh.2019.02.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 01/15/2019] [Accepted: 02/06/2019] [Indexed: 02/07/2023] Open
Abstract
Brain edema is a common feature associated with hepatic encephalopathy (HE). In patients with acute HE, brain edema has been shown to play a crucial role in the associated neurological deterioration. In chronic HE, advanced magnetic resonance imaging (MRI) techniques have demonstrated that low-grade brain edema appears also to be an important pathological feature. This review explores the different methods used to measure brain edema ex vivo and in vivo in animal models and in humans with chronic HE. In addition, an in-depth description of the main studies performed to date is provided. The role of brain edema in the neurological alterations linked to HE and whether HE and brain edema are the manifestations of the same pathophysiological mechanism or two different cerebral manifestations of brain dysfunction in liver disease are still under debate. In vivo MRI/magnetic resonance spectroscopy studies have allowed insight into the development of brain edema in chronic HE. However, additional in vivo longitudinal and multiparametric/multimodal studies are required (in humans and animal models) to elucidate the relationship between liver function, brain metabolic changes, cellular changes, cell swelling, and neurological manifestations in chronic HE.
Collapse
Key Words
- 1H MRS, proton magnetic resonance spectroscopy
- ADC, apparent diffusion coefficient
- ALF, acute liver failure
- AQP, aquaporins
- BBB, blood-brain barrier
- BDL, bile duct ligation
- CNS, central nervous system
- CSF, cerebrospinal fluid
- Cr, creatine
- DTI, diffusion tensor imaging
- DWI, diffusion-weighted imaging
- FLAIR, fluid-attenuated inversion recovery
- GM, gray matter
- Gln, glutamine
- Glx, sum of glutamine and glutamate
- HE, hepatic encephalopathy
- Ins, inositol
- LPS, lipopolysaccharide
- Lac, lactate
- MD, mean diffusivity
- MRI, magnetic resonance imaging
- MRS, magnetic resonance spectroscopy
- MT, magnetization transfer
- MTR, MT ratio
- NMR, nuclear magnetic resonance
- PCA, portocaval anastomosis
- TE, echo time
- WM, white matter
- brain edema
- chronic hepatic encephalopathy
- in vivo magnetic resonance imaging
- in vivo magnetic resonance spectroscopy
- liver cirrhosis
- mIns, myo-inositol
- tCho, total choline
- tCr, total creatine
Collapse
Affiliation(s)
- Cristina Cudalbu
- Centre d'Imagerie Biomedicale (CIBM), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Simon D. Taylor-Robinson
- Division of Integrative Systems Medicine and Digestive Disease, Department of Surgery and Cancer, St Mary's Hospital Campus, Imperial College London, London, United Kingdom
| |
Collapse
|
18
|
Abstract
Neuropathology of hepatic encephalopathy (HE) in cirrhosis is primarily astroglial in nature characterized by Alzheimer type 2 astrocytosis together with activation of microglia indicative of neuroinflammation. Focal loss of neurons may also occur in the basal ganglia, thalamus and cerebellum. Pathophysiology of HE in cirrhosis is multifactorial, involving brain accumulation of ammonia and manganese, systemic and central inflammation, nutritional/metabolic factors and activation of the GABAergic neurotransmitter system. Neuroimaging and spectroscopic techniques reveal early deactivation of the anterior cingulate cortex in parallel with neuropsychological impairment. T1-weighted MR signal hyperintensities in basal ganglia resulting from manganese lead to a novel entity, 'Parkinsonism in cirrhosis'. Elucidation of the pathophysiological mechanisms has resulted in novel therapeutic approaches to HE aimed at reduction of brain ammonia, reduction of systemic and central inflammation, and reduction of GABAergic tone via the discovery of antagonists of the neurosteroid-modulatory site on the GABA receptor complex.
Collapse
Affiliation(s)
- Roger F Butterworth
- Department of Medicine, University of Montreal, 45143 Cabot Trail, Englishtown, NS, B0C 1H0, Canada.
| |
Collapse
|
19
|
Ning Q. Main Complications of AECHB and Severe Hepatitis B (Liver Failure). ACUTE EXACERBATION OF CHRONIC HEPATITIS B 2019. [PMCID: PMC7498917 DOI: 10.1007/978-94-024-1603-9_2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Qin Ning
- Department of Infectious Disease, Tongji Hospital, Wuhan, China
| |
Collapse
|
20
|
Ochoa-Sanchez R, Rose CF. Pathogenesis of Hepatic Encephalopathy in Chronic Liver Disease. J Clin Exp Hepatol 2018; 8:262-271. [PMID: 30302043 PMCID: PMC6175755 DOI: 10.1016/j.jceh.2018.08.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 08/09/2018] [Indexed: 12/12/2022] Open
Abstract
Hepatic encephalopathy (HE) is a complex neuropsychiatric syndrome that occurs during chronic liver disease (CLD). While ammonia and other precipitating factors in liver disease including inflammation, bile acids, oxidative stress, and lactate play a role in the pathogenesis of HE, the exact mechanism that leads to HE is not fully understood. Notably, accumulating evidence points toward a synergic effect rather than independent actions among precipitating factors that contributes to the development and severity of HE in CLD. Hence, this review is aimed to briefly discuss the single and synergic interplay of pathological factors in the progression and severity of HE.
Collapse
Key Words
- AQP4, Aquaporin 4
- BAs, Bile Acids
- BBB, Blood-Brain Barrier
- BDL, Bile Duct Ligation
- CLD, Chronic Liver Disease
- CSF, Cerebrospinal Fluid
- GABA, Gamma-Aminobutyric Acid
- GAMSAs, GABAA Receptor Modulating Steroid Antagonists
- GFAP, Glial Fibrillary Acid Protein
- GLAST, Glial Glutamate-Aspartate Transporter
- GPR81, G-Protein-Coupled Receptor 81
- GS, Glutamine Synthetase
- HE, Hepatic Encephalopathy
- ICP, Intracranial Pressure
- ILs, Interleukins
- MRI, Magnetic Resonance Imaging
- NF-?B, Nuclear Factor Kappa B
- NMDA, N-Methyl-d-Aspartate Glutamate Receptor
- NO, Nitric Oxide
- PCA, Portacaval Anastomosis
- ROS, Reactive Oxygen Species
- TJ, Tight Junction
- TNF-a, Tumor Necrosis Alpha
- ammonia
- astrocyte swelling
- bile acids
- brain edema
- cGMP, Cyclic Guanosine Monophosphate
- cirrhosis
- hepatic encephalopathy
- inflammation
- lactate
- mGluR, Metabotropic Glutamate Receptor
- neurotransmission
- oxidative stress
Collapse
Affiliation(s)
| | - Christopher F. Rose
- Address for correspondence. Christopher F. Rose Professor, Dept. Medicine, Université de Montréal, CRCHUM, 900 Saint-Denis Street, Montréal, Québec, H2X 0A9, Canada.
| |
Collapse
|
21
|
Abstract
Background Central nervous system complications after transplantation occur in up to 40% of recipients and these complications are associated with increased length of hospital stay and mortality. Catatonia is a neuropsychiatric clinical syndrome which has been described in case reports and in a small case series as occurring in the immediate post-solid organ transplantation (SOT) period, and it has been attributed to calcineurin inhibitor neurotoxicity, psychological vulnerability, and depression. Among transplant recipients, the incidence of catatonia is unknown; it may be under diagnosed in part due to a broad differential diagnosis in the post-transplantation setting, which includes hypoactive delirium, non-convulsive status epilepticus, drug toxicity, conversion disorder, and volitional uncooperativeness. Case Report We present 2 cases of catatonia diagnosed in liver allograft recipients. We also reviewed current literature for cases of catatonia among SOT recipients. We provide provisional evaluation and management strategies of recipients with clinical concern for catatonia. Conclusions Despite difficulties in establishing the diagnosis, catatonia after liver transplantation was rapidly responsive to intravenous lorazepam, indicating that changing immunosuppressants may be avoidable.
Collapse
Affiliation(s)
- Jason R Tatreau
- Department of Psychiatry, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Sarah L Laughon
- Department of Psychiatry, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Tomasz Kozlowski
- Department of Surgery, Division of Abdominal Transplant, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
| |
Collapse
|
22
|
Bajaj JS, Kassam Z, Fagan A, Gavis EA, Liu E, Cox IJ, Kheradman R, Heuman D, Wang J, Gurry T, Williams R, Sikaroodi M, Fuchs M, Alm E, John B, Thacker LR, Riva A, Smith M, Taylor-Robinson SD, Gillevet PM. Fecal microbiota transplant from a rational stool donor improves hepatic encephalopathy: A randomized clinical trial. Hepatology 2017; 66:1727-1738. [PMID: 28586116 PMCID: PMC6102730 DOI: 10.1002/hep.29306] [Citation(s) in RCA: 391] [Impact Index Per Article: 55.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 05/12/2017] [Accepted: 06/05/2017] [Indexed: 12/11/2022]
Abstract
UNLABELLED Recurrent hepatic encephalopathy (HE) is a leading cause of readmission despite standard of care (SOC) associated with microbial dysbiosis. Fecal microbiota transplantation (FMT) may improve dysbiosis; however, it has not been studied in HE. We aimed to define whether FMT using a rationally derived stool donor is safe in recurrent HE compared to SOC alone. An open-label, randomized clinical trial with a 5-month follow-up in outpatient men with cirrhosis with recurrent HE on SOC was conducted with 1:1 randomization. FMT-randomized patients received 5 days of broad-spectrum antibiotic pretreatment, then a single FMT enema from the same donor with the optimal microbiota deficient in HE. Follow-up occurred on days 5, 6, 12, 35, and 150 postrandomization. The primary outcome was safety of FMT compared to SOC using FMT-related serious adverse events (SAEs). Secondary outcomes were adverse events, cognition, microbiota, and metabolomic changes. Participants in both arms were similar on all baseline criteria and were followed until study end. FMT with antibiotic pretreatment was well tolerated. Eight (80%) SOC participants had a total of 11 SAEs compared to 2 (20%) FMT participants with SAEs (both FMT unrelated; P = 0.02). Five SOC and no FMT participants developed further HE (P = 0.03). Cognition improved in the FMT, but not the SOC, group. Model for End-Stage Liver Disease (MELD) score transiently worsened postantibiotics, but reverted to baseline post-FMT. Postantibiotics, beneficial taxa, and microbial diversity reduction occurred with Proteobacteria expansion. However, FMT increased diversity and beneficial taxa. SOC microbiota and MELD score remained similar throughout. CONCLUSION FMT from a rationally selected donor reduced hospitalizations, improved cognition, and dysbiosis in cirrhosis with recurrent HE. (Hepatology 2017;66:1727-1738).
Collapse
Affiliation(s)
- Jasmohan S. Bajaj
- Virginia Commonwealth University and McGuire VA Medical Center, Richmond, Virginia, USA
| | - Zain Kassam
- OpenBiome, Somerville, Massachusetts, USA,Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Andrew Fagan
- Virginia Commonwealth University and McGuire VA Medical Center, Richmond, Virginia, USA
| | - Edith A. Gavis
- Virginia Commonwealth University and McGuire VA Medical Center, Richmond, Virginia, USA
| | - Eric Liu
- George Mason University, Manassas, Virginia, USA
| | - I. Jane Cox
- Institute of Hepatology London, Foundation for Liver Research, United Kingdom
| | | | - Douglas Heuman
- Virginia Commonwealth University and McGuire VA Medical Center, Richmond, Virginia, USA
| | - Jessica Wang
- George Mason University, Manassas, Virginia, USA
| | - Thomas Gurry
- Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Roger Williams
- Institute of Hepatology London, Foundation for Liver Research, United Kingdom
| | | | - Michael Fuchs
- Virginia Commonwealth University and McGuire VA Medical Center, Richmond, Virginia, USA
| | - Eric Alm
- Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Binu John
- Virginia Commonwealth University and McGuire VA Medical Center, Richmond, Virginia, USA
| | - Leroy R Thacker
- Virginia Commonwealth University and McGuire VA Medical Center, Richmond, Virginia, USA
| | - Antonio Riva
- Institute of Hepatology London, Foundation for Liver Research, United Kingdom
| | - Mark Smith
- OpenBiome, Somerville, Massachusetts, USA
| | | | | |
Collapse
|
23
|
Grønbæk L, Watson H, Vilstrup H, Jepsen P. Benzodiazepines and risk for hepatic encephalopathy in patients with cirrhosis and ascites. United European Gastroenterol J 2017; 6:407-412. [PMID: 29774154 DOI: 10.1177/2050640617727179] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 07/26/2017] [Indexed: 12/31/2022] Open
Abstract
Background There is limited evidence to support the belief that benzodiazepines increase cirrhosis patients' risk of hepatic encephalopathy (HE). Objective We aimed to examine the association between benzodiazepine use and HE development in cirrhosis patients. Methods We used data on 865 cirrhosis patients with ascites from three trials to study the effect of benzodiazepine use on development of first-time HE. For each patient, we classified periods of benzodiazepine use by the number of days since initiation. We used Cox regression to compare the risk of HE in current benzodiazepine users vs. non-users adjusting for confounders. Results Cirrhosis patients were not at increased risk of HE for the first two days of benzodiazepine use, but then faced a five-fold increased risk of HE during days 3 to 10 of benzodiazepine use. The risk of HE was not increased for those who had been using benzodiazepines for more than 28 days. Conclusion Cirrhosis patients who had begun using benzodiazepines between 3 and 10 days previously had a markedly increased risk of developing first-time HE. Cirrhosis patients who had been using benzodiazepines for just one or two days or continued use for more than 28 days did not have such an excess risk.
Collapse
Affiliation(s)
- Lisbet Grønbæk
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark.,Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark
| | | | - Hendrik Vilstrup
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
| | - Peter Jepsen
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark.,Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark
| |
Collapse
|
24
|
Suraweera D, Sundaram V, Saab S. Evaluation and Management of Hepatic Encephalopathy: Current Status and Future Directions. Gut Liver 2017; 10:509-19. [PMID: 27377741 PMCID: PMC4933409 DOI: 10.5009/gnl15419] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 08/31/2015] [Indexed: 12/18/2022] Open
Abstract
Hepatic encephalopathy is a spectrum of neurocognitive manifestations often seen in patients with liver injury or rarely in patients with portosystemic shunting without liver injury. It can be divided into minimal (covert) hepatic encephalopathy and overt hepatic encephalopathy, depending on the severity. Patients with hepatic encephalopathy have compromised clinical outcomes, decreased quality of life, and increased healthcare utilization, often resulting in a heavy financial and personal burden on caregivers. The diagnosis remains largely clinical, with the exclusion of possible other causes for the altered mental status. Current treatment strategies include nonabsorbable disaccharides and antibiotics. This review will focus on the diagnosis, management and clinical impact of hepatic encephalopathy.
Collapse
Affiliation(s)
| | - Vinay Sundaram
- Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Sammy Saab
- Department of Medicine, University of California at Los Angeles, Los Angeles, CA, USA.,Department of Surgery, University of California at Los Angeles, Los Angeles, CA, USA
| |
Collapse
|
25
|
Adlimoghaddam A, Sabbir MG, Albensi BC. Ammonia as a Potential Neurotoxic Factor in Alzheimer's Disease. Front Mol Neurosci 2016; 9:57. [PMID: 27551259 PMCID: PMC4976099 DOI: 10.3389/fnmol.2016.00057] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 07/06/2016] [Indexed: 11/13/2022] Open
Abstract
Ammonia is known to be a potent neurotoxin that causes severe negative effects on the central nervous system. Excessive ammonia levels have been detected in the brain of patients with neurological disorders such as Alzheimer disease (AD). Therefore, ammonia could be a factor contributing to the progression of AD. In this review, we provide an introduction to the toxicity of ammonia and putative ammonia transport proteins. We also hypothesize how ammonia may be linked to AD. Additionally, we discuss the evidence that support the hypothesis that ammonia is a key factor contributing to AD progression. Lastly, we summarize the old and new experimental evidence that focuses on energy metabolism, mitochondrial function, inflammatory responses, excitatory glutamatergic, and GABAergic neurotransmission, and memory in support of our ammonia-related hypotheses of AD.
Collapse
Affiliation(s)
- Aida Adlimoghaddam
- Division of Neurodegenerative Disorders, St. Boniface Hospital Research Winnipeg, MB, Canada
| | - Mohammad G Sabbir
- Division of Neurodegenerative Disorders, St. Boniface Hospital Research Winnipeg, MB, Canada
| | - Benedict C Albensi
- Division of Neurodegenerative Disorders, St. Boniface Hospital ResearchWinnipeg, MB, Canada; Department of Pharmacology & Therapeutics, University of ManitobaWinnipeg, MB, Canada
| |
Collapse
|
26
|
Efficient bioconversion of L-glutamate to γ-aminobutyric acid by Lactobacillus brevis resting cells. J Ind Microbiol Biotechnol 2016; 44:697-704. [PMID: 27155855 DOI: 10.1007/s10295-016-1777-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 04/11/2016] [Indexed: 10/21/2022]
Abstract
This work investigated the efficient bioconversion process of L-glutamate to GABA by Lactobacillus brevis TCCC 13007 resting cells. The optimal bioconversion system was composed of 50 g/L 48 h cultivated wet resting cells, 0.1 mM pyridoxal phosphate in glutamate-containing 0.6 M citrate buffer (pH 4.5) and performed at 45 °C and 180 rpm. By 10 h bioconversion at the ratio of 80 g/L L-glutamic acid to 240 g/L monosodium glutamate, the final titer of GABA reached 201.18 g/L at the molar bioconversion ratio of 99.4 %. This process presents a potential for industrial and commercial applications and also offers a promising feasibility of continuous GABA production coupled with fermentation. Besides, the built kinetics model revealed that the optimum operating conditions were 45 °C and pH 4.5, and the bioconversion kinetics at low ranges of substrate concentration (0 < S < 80 g/L) was assumed to follow the classical Michaelis-Menten equation.
Collapse
|
27
|
Abstract
Hepatic encephalopathy (HE) is a commonly encountered sequela of chronic liver disease and cirrhosis with significant associated morbidity and mortality. Although ammonia is implicated in the pathogenesis of HE, the exact underlying mechanisms still remain poorly understood. Its role in the urea cycle, astrocyte swelling, and glutamine and gamma-amino-n-butyric acid systems suggests that the pathogenesis is multifaceted. Greater understanding in its underlying mechanism may offer more targeted therapeutic options in the future, and thus further research is necessary to fully understand the pathogenesis of HE.
Collapse
Affiliation(s)
- Parth J Parekh
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Tulane University, New Orleans, LA, USA
| | - Luis A Balart
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Tulane University, New Orleans, LA, USA.
| |
Collapse
|
28
|
Macías-Rodríguez RU, Duarte-Rojo A, Cantú-Brito C, Sauerbruch T, Ruiz-Margáin A, Trebicka J, Green-Gómez M, Díaz Ramírez JB, Sierra Beltrán M, Uribe-Esquivel M, Torre A. Cerebral haemodynamics in cirrhotic patients with hepatic encephalopathy. Liver Int 2015; 35:344-52. [PMID: 24690075 DOI: 10.1111/liv.12557] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Accepted: 03/27/2014] [Indexed: 02/13/2023]
Abstract
BACKGROUND & AIMS Factors other than elevated levels of ammonia may be implicated in hepatic encephalopathy (HE) pathophysiology, including abnormal cerebral haemodynamics. Transcranial Doppler ultrasonography (TCD) evaluates cerebrovascular structural integrity and reactivity, through pulsatility index (PI) and breath-holding index (BHI) respectively. The aim of this study was to evaluate cerebral haemodynamics by TCD in patients with compensated and decompensated cirrhosis, and patients with and without HE. METHODS We studied 90 subjects by TCD measuring PI and BHI in the middle cerebral artery: 30 with cirrhosis and no HE, 30 with cirrhosis and low-grade HE and 30 healthy subjects. Critical flicker frequency, psychometric hepatic encephalopathy score and West-Haven criteria were performed to assess MHE and HE respectively. RESULTS Pulsatility index increased in decompensated cirrhotics (Child ≥ 7) when compared with compensated cirrhotics and healthy subjects [median (IQR) 1.07 (0.95-1.21) vs 0.90 (0.83-1.05) vs 0.87 (0.78-0.96); P < 0.001]. A reverse relationship was observed for BHI among the three groups [0.82 (0.45-1.11) vs 1.20 (0.82-1.52) vs 1.28 (1.06-1.68); P < 0.001]. Similar findings were observed in decompensation [model for end-stage liver disease (MELD) score ≥14]. Patients with HE showed higher PI and lower BHI [1.05 (1.00-1.16) and 0.89 (0.59-1.15)], when compared with patients without HE [0.96 (0.83-1.13) and 1.00 (0.60-1.53)] or controls [0.87 (0.78-0.96) and 1.28 (1.06-1.68)] (P < 0.001 for PI, and P = 0.007 for BHI). In multivariate regression models, only PI predicted HE, but it was outperformed by MELD-sodium and tumour necrosis factor-alpha. CONCLUSIONS These results indicate that cerebral haemodynamics are altered in patients with cirrhosis, in relation to severity of disease and HE. Findings on impaired PI and BHI suggest that structural vascular damage and loss of vascular autoregulation are implicated in the pathophysiology of HE.
Collapse
Affiliation(s)
- Ricardo U Macías-Rodríguez
- Liver Clinic, Department of Gastroenterology, Instituto Nacional de Ciencias Médicas y Nutrición "Salvador Zubirán", México D.F, Tlalpan, México
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Abstract
Human adults produce around 1000 mmol of ammonia daily. Some is reutilized in biosynthesis. The remainder is waste and neurotoxic. Eventually most is excreted in urine as urea, together with ammonia used as a buffer. In extrahepatic tissues, ammonia is incorporated into nontoxic glutamine and released into blood. Large amounts are metabolized by the kidneys and small intestine. In the intestine, this yields ammonia, which is sequestered in portal blood and transported to the liver for ureagenesis, and citrulline, which is converted to arginine by the kidneys. The amazing developments in NMR imaging and spectroscopy and molecular biology have confirmed concepts derived from early studies in animals and cell cultures. The processes involved are exquisitely tuned. When they are faulty, ammonia accumulates. Severe acute hyperammonemia causes a rapidly progressive, often fatal, encephalopathy with brain edema. Chronic milder hyperammonemia causes a neuropsychiatric illness. Survivors of severe neonatal hyperammonemia have structural brain damage. Proposed explanations for brain edema are an increase in astrocyte osmolality, generally attributed to glutamine accumulation, and cytotoxic oxidative/nitrosative damage. However, ammonia neurotoxicity is multifactorial, with disturbances also in neurotransmitters, energy production, anaplerosis, cerebral blood flow, potassium, and sodium. Around 90% of hyperammonemic patients have liver disease. Inherited defects are rare. They are being recognized increasingly in adults. Deficiencies of urea cycle enzymes, citrin, and pyruvate carboxylase demonstrate the roles of isolated pathways in ammonia metabolism. Phenylbutyrate is used routinely to treat inherited urea cycle disorders, and its use for hepatic encephalopathy is under investigation.
Collapse
Affiliation(s)
- Valerie Walker
- Department of Clinical Biochemistry, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.
| |
Collapse
|
30
|
Gluud LL, Dam G, Borre M, Les I, Cordoba J, Marchesini G, Aagaard NK, Vilstrup H. Lactulose, rifaximin or branched chain amino acids for hepatic encephalopathy: what is the evidence? Metab Brain Dis 2013; 28:221-5. [PMID: 23275147 DOI: 10.1007/s11011-012-9372-0] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Accepted: 12/17/2012] [Indexed: 12/12/2022]
Abstract
Hepatic encephalopathy (HE) is a serious complication of acute and chronic liver disease associated with severe morbidity and mortality. We performed updated random effects meta-analyses to evaluate the evidence for non-absorbable disaccharides (lactulose and lactitol), rifaximin and branched chain amino acids (BCAA). A meta-analysis of randomized trials showed that, compared with placebo or no intervention, non-absorbable disaccharides have beneficial effects on HE manifestations and prevention of HE episodes. The addition of rifaximin to non-absorbable disaccharides versus rifaximin alone was more beneficial than non-absorbable disaccharides used alone on both outcome measures. Likewise, a meta-analysis of randomised controlled trials found that oral BCAA supplements have beneficial effects on manifestations of HE compared with control supplements. The effect was found in a variety of clinical settings. No convincing effects of intravenous BCAA for episodic HE were identified. In conclusion, evidence-based treatment recommendations for patients with HE should include non-absorbable disaccharides combined with rifaximin or BCAA. Additional evidence is needed to evaluate the effect of combining all three interventions.
Collapse
Affiliation(s)
- Lise Lotte Gluud
- Department of Medicine, Copenhagen University Hospital Gentofte, Hellerup, Denmark.
| | | | | | | | | | | | | | | |
Collapse
|
31
|
Sergeeva OA. GABAergic transmission in hepatic encephalopathy. Arch Biochem Biophys 2013; 536:122-30. [PMID: 23624382 DOI: 10.1016/j.abb.2013.04.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Revised: 04/08/2013] [Accepted: 04/09/2013] [Indexed: 01/05/2023]
Abstract
Hepatic encephalopathy (HE)(1) is a neuropsychiatric disorder caused by chronic or acute liver failure. Nearly thirty years ago a hypothesis was formulated explaining the neuropathology of HE by increased GABAergic tone. Recent progress in the GABAA-receptor (GABAAR) molecular pharmacology and biochemistry as well as the physiology of GABAergic transmission provided better understanding of GABA's role in health and disease. A detailed analysis of neuronal populations and their GABAergic afferents affected in HE is still missing. The slow progress in understanding the pathology of GABAergic transmission in HE is due to the high complexity of brain circuitries controlled by multiple types of GABAergic interneurons and the large variety of GABAAR, which are differently affected by pathological conditions and not yet fully identified. The mechanisms of action of the GABAAR agonist taurine, allosteric positive modulators (inhibitory neurosteroids, anaesthetics, benzodiazepines and histamine) and inhibitors of the GABAAR (excitatory neurosteroids, Ro15-4513) are discussed with respect to HE pathophysiology. Perspectives for GABAergic drugs in the symptomatic treatment of HE are suggested.
Collapse
Affiliation(s)
- Olga A Sergeeva
- Department of Neurophysiology, Medical Faculty, Heinrich-Heine-University, D-40225 Düsseldorf, Germany.
| |
Collapse
|
32
|
Cichoż-Lach H, Michalak A. Current pathogenetic aspects of hepatic encephalopathy and noncirrhotic hyperammonemic encephalopathy. World J Gastroenterol 2013; 19:26-34. [PMID: 23326159 PMCID: PMC3545226 DOI: 10.3748/wjg.v19.i1.26] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Revised: 07/25/2012] [Accepted: 07/28/2012] [Indexed: 02/06/2023] Open
Abstract
Hepatic encephalopathy is a medical phenomenon that is described as a neuropsychiatric manifestation of chronic or acute liver disease that is characterized by psychomotor, intellectual and cognitive abnormalities with emotional/affective and behavioral disturbances. This article focuses on the underlying mechanisms of the condition and the differences between hepatic encephalopathy and noncirrhotic hyperammonemic encephalopathy. Hepatic encephalopathy is a serious condition that can cause neurological death with brain edema and intracranial hypertension. It is assumed that approximately 60%-80% of patients with liver cirrhosis develop hepatic encephalopathy. This review explores the complex mechanisms that lead to hepatic encephalopathy. However, noncirrhotic hyperammonemic encephalopathy is not associated with hepatic diseases and has a completely different etiology. Noncirrhotic hyperammonemic encephalopathy is a severe occurrence that is connected with multiple pathogeneses.
Collapse
|
33
|
Zhang Y, Song L, Gao Q, Yu SM, Li L, Gao NF. The two-step biotransformation of monosodium glutamate to GABA by Lactobacillus brevis growing and resting cells. Appl Microbiol Biotechnol 2012; 94:1619-27. [DOI: 10.1007/s00253-012-3868-8] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2011] [Revised: 12/21/2011] [Accepted: 12/24/2011] [Indexed: 11/30/2022]
|
34
|
Malaguarnera M, Vacante M, Giordano M, Pennisi G, Bella R, Rampello L, Malaguarnera M, Li Volti G, Galvano F. Oral acetyl-L-carnitine therapy reduces fatigue in overt hepatic encephalopathy: a randomized, double-blind, placebo-controlled study. Am J Clin Nutr 2011; 93:799-808. [PMID: 21310833 DOI: 10.3945/ajcn.110.007393] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND Fatigue is frequently reported in hepatic encephalopathy (HE) and may be related to hyperammonemia. Acetyl-L-carnitine (ALC) offers neuroprotective benefits and improves mitochondrial energetics and function. OBJECTIVE This study evaluated the effect of exogenous ALC on physical and mental fatigue, fatigue severity, and physical activity in patients with mild and moderate hepatoencephalopathy (HE1 and HE2, respectively). DESIGN A total of 121 patients with overt HE were recruited to the study and were subdivided into 2 groups according to their initial HE grade [HE1 (n = 61) or HE2 (n = 60)]. Thirty-one patients with HE1 and 30 with HE2 received 2 g ALC, and 30 patients with HE1 and 30 patients with HE2 received placebo twice a day for 90 d. All patients underwent clinical and laboratory assessments and automated electroencephalogram analysis. RESULTS At the end of the study period, the ALC-treated patients in the HE1 group showed significantly better improvement than did the placebo group in mental fatigue score (-1.7 compared with -0.3; P < 0.05), the fatigue severity scale (-6.4 compared with 2.3; P < 0.001), 7-d Physical Activity Recall questionnaire score (17.1 compared with -2.5; P < 0.001), and Short Physical Performance Battery (2.1 compared with 0.2; P < 0.001); the HE2 group showed significantly better improvement in the fatigue severity scale (-8.1 compared with -5.1; P < 0.001) and 6-min walk test (19.9 compared with 2.3; P < 0.05). Significant decreases in NH(4)(+) were observed in both groups (P < 0.001). CONCLUSION Patients with HE treated with ALC showed a decrease in the severity of both mental and physical fatigue and an increase in physical activity. This trial was registered at clinicaltrials.gov as NCT01223742.
Collapse
Affiliation(s)
- Michele Malaguarnera
- Department of Biological Chemistry, Medical Chemistry, and Molecular Biology, University of Catania, Italy.
| | | | | | | | | | | | | | | | | |
Collapse
|
35
|
McPhail MJW, Bajaj JS, Thomas HC, Taylor-Robinson SD. Pathogenesis and diagnosis of hepatic encephalopathy. Expert Rev Gastroenterol Hepatol 2010; 4:365-78. [PMID: 20528123 DOI: 10.1586/egh.10.32] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Hepatic encephalopathy (HE) is a common and potentially devastating neuropsychiatric complication of acute liver failure and cirrhosis. Even in its mildest form, minimal HE (MHE), the syndrome significantly impacts daily living and heralds progression to overt HE. There is maturity in the scientific understanding of the cellular processes that lead to functional and structural abnormalities in astrocytes. Hyperammonemia and subsequent cell swelling is a key pathophysiological abnormality, but this aspect alone is insufficient to fully explain the complex neurotransmitter abnormalities that may be observable using sophisticated imaging techniques. Inflammatory cytokines, reactive oxygen species activation and the role of neurosteroids on neurotransmitter binding sites are emerging pathological lines of inquiry that have yielded important new information on the processes underlying HE and offer promise of future therapeutic targets. Overt HE remains a clinical diagnosis and the neurophysiological and imaging modalities used in research studies have not transferred successfully to the clinical situation. MHE is best characterized by psychometric evaluation, but these tests can be lengthy to perform and require specific expertise to interpret. Simpler computer-based tests are now available and perhaps offer an opportunity to screen, diagnose and monitor MHE in a clinical scenario, although large-scale studies comparing the different techniques have not been undertaken. There is a discrepancy between the depth of understanding of the pathophysiology of HE and the translation of this understanding to a simple, easily understood diagnostic and longitudinal marker of disease. This is a present area of focus for the management of HE.
Collapse
Affiliation(s)
- Mark J W McPhail
- Hepatology Section, Department of Medicine, 10th Floor QEQM Wing, St Mary's Hospital Campus, Imperial College London, South Wharf Street, London W2 1NY, UK
| | | | | | | |
Collapse
|
36
|
Zhang Y, Gao NF, Feng Y, Song L, Gao Q. Biotransformation of Sodium L-Glutamate to gamma-Aminobutyric Acid by L. Brevis TCCC13007 with Two Glutamate Decarboxylase Genes. ACTA ACUST UNITED AC 2010. [DOI: 10.1109/icbbe.2010.5518023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
37
|
Considerations on the impact of hepatic encephalopathy treatments in the pretransplant setting. Transplantation 2010; 89:771-8. [PMID: 20110852 DOI: 10.1097/tp.0b013e3181d2fe66] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Hepatic encephalopathy (HE) is a common complication of acute and chronic liver disease associated with exposure of brain tissue to excessive levels of ammonia produced by intestinal bacteria. Clinical manifestations range from subtle neurologic abnormalities to coma. Because development of HE can reduce survival probability, guidelines for evaluating patients for liver transplantation suggest that patients who develop HE should be considered for transplantation. Various patient factors before transplantation, including the presence of HE and reduced nutritional status, may increase the risk of poor outcomes after transplantation. Therefore, effective management of HE before transplantation, while minimizing the potential impact of negative predictive factors, may improve transplantation outcomes. The most common HE treatments are directed toward reducing systemic ammonia levels, thereby reducing brain exposure to this neurotoxin. The administration of nonabsorbable disaccharides is considered as a first-line therapy for HE, and the antibiotics neomycin and metronidazole are frequently administered, despite a lack of clinical data supporting their efficacy. These agents are associated with adverse events that may reduce nutritional status in patients awaiting transplantation and could contribute to poor posttransplantation outcomes. The nonsystemic antibiotic rifaximin has demonstrated efficacy for the treatment of HE and has a favorable safety profile. Given these data, nonsystemic antibiotics may also provide a safe and effective option for treating HE in the pretransplant setting. This article reviews treatments for HE and the potential impact these treatments may have on pretransplantation status of patients awaiting liver transplantation and on posttransplantation outcomes.
Collapse
|
38
|
Acharya SK, Bhatia V, Sreenivas V, Khanal S, Panda SK. Efficacy of L-ornithine L-aspartate in acute liver failure: a double-blind, randomized, placebo-controlled study. Gastroenterology 2009; 136:2159-68. [PMID: 19505424 DOI: 10.1053/j.gastro.2009.02.050] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2008] [Revised: 01/09/2009] [Accepted: 02/10/2009] [Indexed: 12/20/2022]
Abstract
BACKGROUND & AIMS In acute liver failure (ALF), high blood ammonia levels have been documented that correlate with mortality and complications. L-ornithine L-aspartate (LOLA) reduces ammonia levels by increasing hepatic ammonia disposal and its peripheral metabolism. Present study evaluated efficacy and ammonia lowering effect of LOLA in ALF. METHODS This study was placebo-controlled and blinded. We randomized 201 patients with ALF between January 2005 and October 2007 to either placebo or LOLA infusions (30 g daily) for 3 days. Arterial ammonia was measured at baseline and daily for 6 days. The primary end point was improvement in survival. The study followed CONSORT guidelines and was registered at the ClinicalTrials.gov (Identifier: NCT00470314). RESULTS There was no reduction in mortality with LOLA treatment (mortality: 33.3% in placebo and 42.4% in LOLA; relative risk of death 1.27; 95% CI: 0.88-1.85; P = .204). By multivariate analysis, ammonia levels were an independent predictor of survival. There was significant decrease in ammonia levels in both groups with time (P < .001), but the levels of ammonia between the randomized groups at any time point, either during the 72 hours of LOLA infusion or during the follow-up were similar (P = .492). There was no difference between the 2 groups in the improvement in encephalopathy grade (P = .418), consciousness recovery time (P = .347), survival time (P = .612), or complications like seizures (P = .058) and renal failure (P = .615). The fetal outcome was also similar (P = .172). No adverse drug effect was noted. CONCLUSIONS LOLA infusion did not lower the ammonia or improved survival in ALF.
Collapse
Affiliation(s)
- Subrat Kumar Acharya
- Department of Gastroenterology, All India Institute of Medical Sciences (AIIMS), New Delhi, India.
| | | | | | | | | |
Collapse
|
39
|
Abstract
Metabolic encephalopathy is an acute disturbance in cellular metabolism in the brain evoked by conditions of hypoxia, hypoglycaemia, oxidative stress and/or inflammation. It usually develops acutely or subacutely and is reversible if the systemic disorder is treated. If left untreated, however, metabolic encephalopathy may result in secondary structural damage to the brain. Most encephalopathies are present with neuropsychiatric symptoms, one in particular being depression. However, mood disorders are often co-morbid with cardiovascular, liver, kidney and endocrine disorders, while increasing evidence concurs that depression involves inflammatory and neurodegenerative processes. This would suggest that metabolic disturbances resembling encephalopathy may underscore the basic neuropathology of depression at a far deeper level than currently realized. Viewing depression as a form of encephalopathy, and exploiting knowledge gleaned from our understanding of the neurochemistry and treatment of metabolic encephalopathy, may assist in our understanding of the neurobiology of depression, but also in realizing new ideas in the pharmacotherapy of mood disorders.
Collapse
Affiliation(s)
- Brian H Harvey
- Unit for Drug Research and Development, Division of Pharmacology, School of Pharmacy, North-West University, Potchefstroom, South Africa.
| |
Collapse
|
40
|
Affiliation(s)
- Emily Ferenczi
- Department of Acute Medicine, Hammersmith Hospital, London, UK.
| | | | | |
Collapse
|
41
|
Sörös P, Böttcher J, Weissenborn K, Selberg O, Müller MJ. Malnutrition and hypermetabolism are not risk factors for the presence of hepatic encephalopathy: a cross-sectional study. J Gastroenterol Hepatol 2008; 23:606-10. [PMID: 18005013 DOI: 10.1111/j.1440-1746.2007.05222.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND AND AIM Hepatic encephalopathy is a frequent complication of cirrhosis. The present retrospective investigation was conducted to characterize metabolic alterations in cirrhotic patients with and without hepatic encephalopathy. We tested the hypothesis that reduced nutritional status or the degree of tissue catabolism are associated with the presence of hepatic encephalopathy. METHODS We investigated 223 patients with histologically confirmed nonalcoholic cirrhosis without hepatic encephalopathy and with hepatic encephalopathy (grades 1-3). To assess liver function, nutritional status, and energy metabolism, a variety of biochemical and clinical tests were performed including anthropometric measurements, bioelectrical impedance analysis, and indirect calorimetry. RESULTS Nutritional status and tissue catabolism were not significantly different between patients with and without hepatic encephalopathy. CONCLUSIONS Our data do not support the hypothesis that malnutrition or tissue catabolism are independent risk factors for the presence of hepatic encephalopathy in patients with nonalcoholic cirrhosis.
Collapse
Affiliation(s)
- Peter Sörös
- Department of Imaging Research, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
| | | | | | | | | |
Collapse
|
42
|
Schliess F, Görg B, Häussinger D. Pathogenetic interplay between osmotic and oxidative stress: the hepatic encephalopathy paradigm. Biol Chem 2006; 387:1363-70. [PMID: 17081108 DOI: 10.1515/bc.2006.171] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Hepatic encephalopathy (HE) defines a primary gliopathy associated with acute and chronic liver disease. Astrocyte swelling triggered by ammonia in synergism with different precipitating factors, including hyponatremia, tumor necrosis factor (TNF)-alpha, glutamate and ligands of the peripheral benzodiazepine receptor (PBR), is an early pathogenetic event in HE. On the other hand, reactive nitrogen and oxygen species (RNOS) including nitric oxide are considered to play a major role in HE. There is growing evidence that osmotic and oxidative stresses are closely interrelated. Astrocyte swelling produces RNOS and vice versa. Based on recent investigations, this review proposes a working model that integrates the pathogenetic action of osmotic and oxidative stresses in HE. Under participation of the N-methyl-D-aspartate (NMDA) receptor, Ca(2+), the PBR and organic osmolyte depletion, astrocyte swelling and RNOS production may constitute an autoamplificatory signaling loop that integrates at least some of the signals released by HE-precipitating factors.
Collapse
Affiliation(s)
- Freimut Schliess
- Clinic for Gastroenterology, Hepatology and Infectiology, Heinrich Heine University, D-40225 Düsseldorf, Germany.
| | | | | |
Collapse
|
43
|
Clementi V, Tonon C, Lodi R, Malucelli E, Barbiroli B, Iotti S. Assessment of glutamate and glutamine contribution to in vivo N-acetylaspartate quantification in human brain by (1)H-magnetic resonance spectroscopy. Magn Reson Med 2006; 54:1333-9. [PMID: 16265633 DOI: 10.1002/mrm.20703] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
N-Acetylaspartate (NAA) is one of the most important metabolites detectable by brain (1)H-MRS being considered an index of neuronal integrity. At the low magnetic field used in most clinical settings beta,gamma-glutamate/glutamine (Glx) resonances are very close and partially overlap the methyl-NAA resonance interfering with NAA quantification especially at low TE and in the presence of increased Glx signals. NAA overestimation due to Glx on a set of model solutions containing NAA, glutamate, and glutamine in variable amounts was evaluated and the result tested in vivo in six healthy controls and five age- and sex-matched patients with hepatic encephalopathy (HE), the latter having an increased Glx content. A method to assess in vivo the NAA overestimation caused by Glx is proposed. A perfect match was obtained between the assessment of Glx contamination on the NAA of healthy controls and that obtained on the model solutions. However, a substantial difference in NAA overestimation was found between controls and HE patients that cannot be explained by our model. An interpretative hypothesis is provided.
Collapse
Affiliation(s)
- Valeria Clementi
- Biochimica Clinica, Dipartimento di Medicina Clinica e Biotecnologia Applicata "D Campanacci," Università di Bologna, Bologna, Italy
| | | | | | | | | | | |
Collapse
|
44
|
Goulet F, Napa ID, Solomon L, Morin O, Islam N. Modulated expression of a nuclear-associated glycoprotein during normal rat liver development and in various hepatoma cells. Prog Neuropsychopharmacol Biol Psychiatry 2006; 30:159-65. [PMID: 16233943 DOI: 10.1016/j.pnpbp.2005.08.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/26/2005] [Indexed: 10/25/2022]
Abstract
Liver plays a major role in systemic detoxification and drug metabolism. NF-164, a protein of 164 kDa predominantly localized in hepatocyte nuclei, was found to be present in increasing amounts during liver maturation. In addition, fetal rat hepatocytes had ten times, and neonatal five times less of this protein than adult hepatocytes. It was also detected in an albumin producing hepatoma cell line, but not in three other lines that have lost several differentiated functions. These data suggest that NF-164 expression is development-dependent and that it may be a marker for both normal and malignant hepatocyte differentiation. NF-164 seems to be liver-specific, since it was not detected in rat brain, spleen, kidney, lung and bovine thymus. It was purified from adult rat hepatocyte nuclei. Its estimated pI is 6.8. Its total amino acid composition and partial amino acid sequence is also being reported. Despite major differences between their respective contents in amino acids, partial sequences showed homologies with carbamyl phosphate synthetase I (CPSI). These observations may suggest that NF-164 also shares some functional features with this enzyme.
Collapse
Affiliation(s)
- Francine Goulet
- Laboratory of Tissue Engineering, Hôpital de l'Enfant-Jésus, 1401 18e rue, Québec, QC, Canada.
| | | | | | | | | |
Collapse
|
45
|
Li XQ, Dong L, Liu ZH, Luo JY. Expression of gamma-aminobutyric acid A receptor subunits α 1, β 1, γ 2 mRNA in rats with hepatic encephalopathy. World J Gastroenterol 2005; 11:3319-22. [PMID: 15929193 PMCID: PMC4316074 DOI: 10.3748/wjg.v11.i21.3319] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the mRNA expression of gamma-aminobutyric acid A (GABAA) receptor subunits α1, β1, γ2 in different parts of the brain of rats with hepatic encephalopathy.
METHODS: Twelve adult male Sprague-Dawley rats were randomly divided into two groups: (1) hepatic encephalopathy model group (n = 6), which was induced by intraperitoneal injection of thioacetamide (TAA, 350 mg/kg) for three consecutive days; (2) control group (n = 6), in which the rats were treated with same dose of normal saline solution. After the freeze slice of cerebrum was made, in situ hybridization was used to detect the mRNA of GABAA receptor subunits α1, β1, and γ2 in rat cerebral cortex, basal nuclei, substantia nigra and hippocampi. Image data were collected and analyzed quantitatively by QWin550CW model image signal gather and analysis system.
RESULTS: In rats with hepatic encephalopathy, mRNA expression levels of GABAA receptor subunits α1, β1 increased significantly in basal nuclei, substantia nigra pars compacta, substantia nigra pars reticularis and hippocampi (144.7±15.67/184.14±4.41, 60.61±33.66/113.07±32.44, 87.71± 21.25/128.40±18.85, 122.34±5.56/161.60±4.56, 123.29±5.21/140.65±4.15, 123.40±4.42/140.09±4.52, 124.76±4.18/140.09±4.12, 141.62±15.09/182.80 ±5.20, 69.13±30.74/134.21±43.76, 87.87±25.16/151.01±19.49, 122.14±6.30 /162.33±3.92, 122.81±5.09/137.19±7.12, 123.00±4.63/138.11±5.92, 125.75 ±2.43/138.81±6.10, P<0.01), but did not change in the cerebral cortex compared to the control group. Similar changes were found in the mRNA expression levels of GABAA receptor subunit γ2, which increased significantly in basal nuclei, substantia nigra pars compacta, substantia nigra pars reticularis (136.81±26.41/167.97±16.23, 51.00±36.14/113.18±36.52, 86.35±20.30/ 126.90±19.74, P<0.01), CA1 of hippocampal (162.15±9.05/178.62±6.45, P<0.05), and no changes were found in the cerebral cortex and CA2, CA3, CA4 of hippocampi.
CONCLUSION: In rats with hepatic encephalopathy, mRNA expression levels of GABAA receptor subunits α1, β1, γ2 increase significantly in basal nuclei, substantia nigra and hippocampi, suggesting that the changes of mRNA expression levels in GABAA receptor subunits may contribute to the pathogenesis of hepatic encephalopathy.
Collapse
Affiliation(s)
- Xiao-Qing Li
- Department of Gastroenterology, Second Hospital of Xi'an Jiaotong University, Xi'an 710004, Shaanxi Province, China.
| | | | | | | |
Collapse
|
46
|
Bélanger M, Desjardins P, Chatauret N, Rose C, Butterworth RF. Mild hypothermia prevents brain edema and attenuates up-regulation of the astrocytic benzodiazepine receptor in experimental acute liver failure. J Hepatol 2005; 42:694-9. [PMID: 15826719 DOI: 10.1016/j.jhep.2004.12.029] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2004] [Revised: 11/26/2004] [Accepted: 12/01/2004] [Indexed: 12/04/2022]
Abstract
BACKGROUND/AIMS Mild hypothermia has proven useful in the clinical management of patients with acute liver failure. Acute liver failure in experimental animals results in alterations in the expression of genes coding for astrocytic proteins including the "peripheral-type" (astrocytic) benzodiazepine receptor (PTBR), a mitochondrial complex associated with neurosteroid synthesis. To gain further insight into the mechanisms whereby hypothermia attenuates the neurological complications of acute liver failure, we investigated PTBR expression in the brains of hepatic devascularized rats under normothermic (37 degrees C) and hypothermic (35 degrees C) conditions. METHODS PTBR mRNA was measured using semi-quantitative RT-PCR in cerebral cortical extracts and densities of PTBR sites were measured by quantitative receptor autoradiagraphy. Brain pregnenolone content was measured by radioimmunoassay. RESULTS At coma stages of encephalopathy, animals with acute liver failure manifested a significant increase of PTBR mRNA levels. Brain pregnenolone content and [(3)H]PK 11195 binding site densities were concomitantly increased. Mild hypothermia prevented brain edema and significantly attenuated the increased receptor expression and pregnenolone content. CONCLUSIONS These findings suggest that an attenuation of PTBR up-regulation resulting in the prevention of increased brain neurosteroid content represents one of the mechanisms by which mild hypothermia exerts its protective effects in ALF.
Collapse
Affiliation(s)
- Mireille Bélanger
- Neuroscience Research Unit, C.H.U.M. (Hôpital Saint-Luc), 1058 St-Denis, Montreal, Que., Canada
| | | | | | | | | |
Collapse
|
47
|
Erceg S, Monfort P, Hernández-Viadel M, Rodrigo R, Montoliu C, Felipo V. Oral administration of sildenafil restores learning ability in rats with hyperammonemia and with portacaval shunts. Hepatology 2005; 41:299-306. [PMID: 15660436 DOI: 10.1002/hep.20565] [Citation(s) in RCA: 130] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
Abstract
Patients with liver disease with overt or minimal hepatic encephalopathy show impaired intellectual capacity. The underlying molecular mechanism remains unknown. Rats with portacaval anastomosis or with hyperammonemia without liver failure also show impaired learning ability and impaired function of the glutamate-nitric oxide-cyclic guanine monophosphate (glutamate-NO-cGMP) pathway in brain. We hypothesized that pharmacological manipulation of the pathway in order to increase cGMP content could restore learning ability. We show by in vivo brain microdialysis that chronic oral administration of sildenafil, an inhibitor of the phosphodiesterase that degrades cGMP, normalizes the function of the glutamate-NO-cGMP pathway and extracellular cGMP in brain in vivo in rats with portacaval anastomosis or with hyperammonemia. Moreover, sildenafil restored the ability of rats with hyperammonemia or with portacaval shunts to learn a conditional discrimination task. In conclusion, impairment of learning ability in rats with chronic liver failure or with hyperammonemia is the result of impairment of the glutamate-NO-cGMP pathway. Moreover, chronic treatment with sildenafil normalizes the function of the pathway and restores learning ability in rats with portacaval shunts or with hyperammonemia. Pharmacological manipulation of the pathway may be useful for the clinical treatment of patients with overt or minimal hepatic encephalopathy.
Collapse
Affiliation(s)
- Slaven Erceg
- Laboratory of Neurobiology, Fundación Valenciana de Investigaciones Biomédicas, Valencia, Spain
| | | | | | | | | | | |
Collapse
|
48
|
Ahboucha S, Butterworth RF. Pathophysiology of hepatic encephalopathy: a new look at GABA from the molecular standpoint. Metab Brain Dis 2004; 19:331-43. [PMID: 15554425 DOI: 10.1023/b:mebr.0000043979.58915.41] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Hepatic encephalopathy (HE) is a neuropsychiatric disorder associated with either acute or chronic liver failure. More than two decades ago, the role of altered GABAergic neurotransmission was proposed following evidence of "increased GABAergic tone" in HE. Increased GABAergic tone was based on several observations: (i) Similarity of visual evoked response potential patterns between rabbits with galactosamine-induced fulminant hepatic failure and animals treated with various allosteric agonists of the GABA receptor complex (GRC). (ii) Spontaneous activities of isolated Purkinje neurons from rabbits with galactosamine-induced fulminant hepatic failure are more depressed by GRC modulator compounds compared to normal animals. (iii) Flumazenil, a high selective benzodiazepine antagonist at the GRC, ameliorates behavioral symptoms and EEG activity in some HE patients. Pathophysiological mechanisms put forward to explain increased GABAergic tone in HE include (1) increase in brain GABA content due to increased brain GABA uptake through altered permeability of the blood brain barrier, (2) alteration of the integrity of constituents of the GRC, and (3) increase of endogenous GRC modulators such as benzodiazepines (and more recently neurosteroids) with potent agonist properties at the GRC. Studies performed subsequently excluded alterations of either GABA content or GRC integrity in favor of increased brain concentrations of endogenous agonists. While the role of endogenous benzodiazepines remains controversial, the presence of neurosteroids with GABA agonist properties affords a plausible explanation for increased GABAergic tone in HE.
Collapse
Affiliation(s)
- Samir Ahboucha
- Neuroscience Research Unit, CHUM (Hopital Saint-Luc), Montreal, Quebec, Canada
| | | |
Collapse
|