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Tsai CY, Lee CL, Wu JCC. Astrocyte-secreted lipocalin-2 elicits bioenergetic failure-induced neuronal death that is causally related to high fatality in a mouse model of hepatic encephalopathy. Neurochem Int 2024; 178:105800. [PMID: 38964718 DOI: 10.1016/j.neuint.2024.105800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 06/24/2024] [Accepted: 07/01/2024] [Indexed: 07/06/2024]
Abstract
Hepatic encephalopathy (HE) is a neurological complication arising from acute liver failure with poor prognosis and high mortality; the underlying cellular mechanisms are still wanting. We previously found that neuronal death caused by mitochondrial dysfunction in rostral ventrolateral medulla (RVLM), which leads to baroreflex dysregulation, is related to high fatality in an animal model of HE. Lipocalin-2 (Lcn2) is a secreted glycoprotein mainly released by astrocytes in the brain. We noted the presence of Lcn2 receptor (Lcn2R) in RVLM neurons and a parallel increase of Lcn2 gene in astrocytes purified from RVLM during experimental HE. Therefore, our guiding hypothesis is that Lcn2 secreted by reactive astrocytes in RVLM may underpin high fatality during HE by eliciting bioenergetic failure-induced neuronal death in this neural substrate. In this study, we first established the role of astrocyte-secreted Lcn2 in a liver toxin model of HE induced by azoxymethane (100 μg/g, ip) in C57BL/6 mice, followed by mechanistic studies in primary astrocyte and neuron cultures prepared from postnatal day 1 mouse pups. In animal study, immunoneutralization of Lcn2 reduced apoptotic cell death in RVLM, reversed defunct baroreflex-mediated vasomotor tone and prolonged survival during experimental HE. In our primary cell culture experiments, Lcn2 produced by cultured astrocytes and released into the astrocyte-conditioned medium significantly reduced cell viability of cultured neurons. Recombinant Lcn2 protein reduced cell viability, mitochondrial ATP (mitoATP) production, and pyruvate dehydrogenase (PDH) activity but enhanced the expression of pyruvate dehydrogenase kinase (PDK) 1, PDK3 and phospho-PDHA1 (inactive PDH) through MAPK/ERK pathway in cultured neurons, with all cellular actions reversed by Lcn2R knockdown. Our results suggest that astrocyte-secreted Lcn2 upregulates PDKs through MAPK/ERK pathway, which leads to reduced PDH activity and mitoATP production; the reinforced neuronal death in RVLM is causally related to baroreflex dysregulation that underlies high fatality associated with HE.
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Affiliation(s)
- Ching-Yi Tsai
- Institute for Translational Research in Biomedicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan.
| | - Chin-Lai Lee
- Institute for Translational Research in Biomedicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan
| | - Jacqueline C C Wu
- Institute for Translational Research in Biomedicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan
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2
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El-Mansoury B, Smimih K, El Khiat A, Draoui A, Aimrane A, Chatoui R, Ferssiwi A, Bitar A, Gamrani H, Jayakumar AR, El Hiba O. Short Working Memory Impairment Associated with Hippocampal Microglia Activation in Chronic Hepatic Encephalopathy. Metabolites 2024; 14:193. [PMID: 38668321 PMCID: PMC11052478 DOI: 10.3390/metabo14040193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Revised: 01/03/2024] [Accepted: 01/06/2024] [Indexed: 04/28/2024] Open
Abstract
Hepatic encephalopathy (HE) is a major neuropsychological condition that occursas a result of impaired liver function. It is frequently observed in patients with advanced liver disease or cirrhosis. Memory impairment is among the symptoms of HE; the pathophysiologic mechanism for this enervating condition remains unclear. However, it is possible that neuroinflammation may be involved, as recent studies have emphasized such phenomena. Therefore, the aim of the present study is to assess short working memory (SWM) and examine the involvement of microglia in a chronic model of HE. The study was carried out with male Wistar rats that were induced by repeated thioacetamide (TAA) administration (100 mg/kg i.p injection for 10 days). SWM function was assessed through Y-maze, T-Maze, and novel object recognition (NOR) tests, together with an immunofluorescence study of microglia activation within the hippocampal areas. Our data showed impaired SWM in TAA-treated rats that was associated with microglial activation in the three hippocampal regions, and which contributed to cognitive impairment.
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Affiliation(s)
- Bilal El-Mansoury
- Laboratory of Anthropogenic, Biotechnology and Health, Nutritional Physiopathologies, Neurosciences and Toxicology Team, Faculty of Sciences, Chouaib Doukkali University, Av. Des Facultés, El Jadida 24000, Morocco; (B.E.-M.); (A.E.K.); (A.A.); (A.F.); (A.B.)
| | - Kamal Smimih
- Laboratory of Genie-Biology, Faculty of Sciences and Techniques, Sultan Moulay Slimane University, Beni Mellal 23000, Morocco; (K.S.); (R.C.)
| | - Abdelaati El Khiat
- Laboratory of Anthropogenic, Biotechnology and Health, Nutritional Physiopathologies, Neurosciences and Toxicology Team, Faculty of Sciences, Chouaib Doukkali University, Av. Des Facultés, El Jadida 24000, Morocco; (B.E.-M.); (A.E.K.); (A.A.); (A.F.); (A.B.)
- Higher Institute of Nursing Professions and Health Techniques, Ministry of Health, Ouarzazate 45000, Morocco
- Laboratory of Clinical and Experimental Neurosciences and Environment, Faculty of Medicine and Pharmacy, Cadi Ayyad University, Marrakech 40000, Morocco
| | - Ahmed Draoui
- Laboratory of Clinical and Experimental Neurosciences and Environment, Faculty of Science Semlalia, Cadi Ayyad University, Marrakech 40000, Morocco; (A.D.); (H.G.)
| | - Abdelmohcine Aimrane
- Laboratory of Anthropogenic, Biotechnology and Health, Nutritional Physiopathologies, Neurosciences and Toxicology Team, Faculty of Sciences, Chouaib Doukkali University, Av. Des Facultés, El Jadida 24000, Morocco; (B.E.-M.); (A.E.K.); (A.A.); (A.F.); (A.B.)
| | - Redouane Chatoui
- Laboratory of Genie-Biology, Faculty of Sciences and Techniques, Sultan Moulay Slimane University, Beni Mellal 23000, Morocco; (K.S.); (R.C.)
| | - Abdesslam Ferssiwi
- Laboratory of Anthropogenic, Biotechnology and Health, Nutritional Physiopathologies, Neurosciences and Toxicology Team, Faculty of Sciences, Chouaib Doukkali University, Av. Des Facultés, El Jadida 24000, Morocco; (B.E.-M.); (A.E.K.); (A.A.); (A.F.); (A.B.)
| | - Abdelali Bitar
- Laboratory of Anthropogenic, Biotechnology and Health, Nutritional Physiopathologies, Neurosciences and Toxicology Team, Faculty of Sciences, Chouaib Doukkali University, Av. Des Facultés, El Jadida 24000, Morocco; (B.E.-M.); (A.E.K.); (A.A.); (A.F.); (A.B.)
| | - Halima Gamrani
- Laboratory of Clinical and Experimental Neurosciences and Environment, Faculty of Science Semlalia, Cadi Ayyad University, Marrakech 40000, Morocco; (A.D.); (H.G.)
| | | | - Omar El Hiba
- Laboratory of Anthropogenic, Biotechnology and Health, Nutritional Physiopathologies, Neurosciences and Toxicology Team, Faculty of Sciences, Chouaib Doukkali University, Av. Des Facultés, El Jadida 24000, Morocco; (B.E.-M.); (A.E.K.); (A.A.); (A.F.); (A.B.)
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3
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Enriched environment ameliorates learning and memory deficits in hepatic encephalopathy mice by restoration of the structure of dendrites and dendritic spines. Brain Res 2023; 1804:148264. [PMID: 36702182 DOI: 10.1016/j.brainres.2023.148264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/17/2022] [Accepted: 01/22/2023] [Indexed: 01/24/2023]
Abstract
Cognitive impairment is one of the most common symptoms of hepatic encephalopathy (HE). However, there is a lack of easily implementable rehabilitation strategies. As an easy-to-implement strategy, numerous studies suggest that enriched environment (EE) can be beneficial for cognitive function. However, the effects of EE on learning and memory, as well as dendritic spines plasticity in HE is still unclear. Accordingly, in the present study, we evaluated the effects of EE on the behavior and dendritic spine morphology in an animal model of HE. Our results showed that HE mice have no movement disorder and anxiety, but they exhibit spatial learning and memory dysfunction. Further analysis revealed that the complexity of the dendrites and the maturity of the dendritic spines are reduced in the hippocampus of HE mice. After 4 weeks of housekeeping in EE, dendritic complexity, and dendritic spine maturity, as well as the spatial learning and memory function of HE mice were restored. In conclusion, exposure to EE can positively influence dendritic spines plasticity in the hippocampus and thereby elicit its beneficial effects on cognitive functions in HE.
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Sepehrinezhad A, Stolze Larsen F, Ashayeri Ahmadabad R, Shahbazi A, Sahab Negah S. The Glymphatic System May Play a Vital Role in the Pathogenesis of Hepatic Encephalopathy: A Narrative Review. Cells 2023; 12:cells12070979. [PMID: 37048052 PMCID: PMC10093707 DOI: 10.3390/cells12070979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 02/20/2023] [Accepted: 03/21/2023] [Indexed: 04/14/2023] Open
Abstract
Hepatic encephalopathy (HE) is a neurological complication of liver disease resulting in cognitive, psychiatric, and motor symptoms. Although hyperammonemia is a key factor in the pathogenesis of HE, several other factors have recently been discovered. Among these, the impairment of a highly organized perivascular network known as the glymphatic pathway seems to be involved in the progression of some neurological complications due to the accumulation of misfolded proteins and waste substances in the brain interstitial fluids (ISF). The glymphatic system plays an important role in the clearance of brain metabolic derivatives and prevents aggregation of neurotoxic agents in the brain ISF. Impairment of it will result in aggravated accumulation of neurotoxic agents in the brain ISF. This could also be the case in patients with liver failure complicated by HE. Indeed, accumulation of some metabolic by-products and agents such as ammonia, glutamine, glutamate, and aromatic amino acids has been reported in the human brain ISF using microdialysis technique is attributed to worsening of HE and correlates with brain edema. Furthermore, it has been reported that the glymphatic system is impaired in the olfactory bulb, prefrontal cortex, and hippocampus in an experimental model of HE. In this review, we discuss different factors that may affect the function of the glymphatic pathways and how these changes may be involved in HE.
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Affiliation(s)
- Ali Sepehrinezhad
- Department of Neuroscience, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran 1449614535, Iran
- Neuroscience Research Center, Mashhad University of Medical Sciences, Mashhad 9919191778, Iran
| | - Fin Stolze Larsen
- Department of Gastroenterology and Hepatology, Rigshospitalet, Copenhagen University Hospital, 999017 Copenhagen, Denmark
| | | | - Ali Shahbazi
- Department of Neuroscience, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran 1449614535, Iran
- Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran 1449614535, Iran
| | - Sajad Sahab Negah
- Neuroscience Research Center, Mashhad University of Medical Sciences, Mashhad 9919191778, Iran
- Shefa Neuroscience Research Center, Khatam Alanbia Hospital, Tehran 1449614535, Iran
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5
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Khalil EA, Swelim H, El-Tantawi H, Abdellatif A. Sea urchin (Diadema savignyi) extract as a novel protective agent against cisplatin induced neurotoxicity in rats. BMC Pharmacol Toxicol 2023; 24:11. [PMID: 36823675 PMCID: PMC9948489 DOI: 10.1186/s40360-023-00651-4] [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: 10/29/2022] [Accepted: 02/08/2023] [Indexed: 02/25/2023] Open
Abstract
Neurotoxicity is a severe side effect of platinum compounds used for cancer chemotherapy such as Cisplatin. This neurotoxicity leads to severe cognitive and nervous dysfunction, therefore, limiting the dose of Cisplatin and compromising the treatment protocol.The present study investigates the neuroprotective effect of Sea Urchins which is a marine animal known for its rich bioactive compounds. Male Sprague Dawley rats received Cisplatin (2 mg/kg body weight) for 4 weeks, two times per week, followed by Sea Urchin extracts (50 and 100 mg/kg body weight) twice weekly for 4 weeks.Results show that rats treated with Urchin's extracts showed a significant improvement in the thermal (heat and cold) sensitivity compared to untreated rats. Liver enzymes Alanine Aminotransferase (ALT) and Aspartate Aminotransferase (AST) and Urea levels were also significantly decreased back to normal following treatment with sea urchin extracts. Brain tissue oxidative stress marker Nitric oxide (NO) and lipid peroxidation marker Malondialdehyde (MDA) increased significantly in the cisplatin-treated rats while the reduced glutathione levels (GSH) and catalase activity (CAT) showed a significant decrease. Treatment with sea Urchin extracts reversed these changes.Histological and immunohistochemical examination of the cerebral cortex reveled degenerative changes such as karyopyknosis and shrunken necrotic ghost like neurons in the cisplatin treated groups. There was also strong positive Glial fibrillary acidic protein (GFAP) reactivity and a negative B-cell leukemia/lymphoma 2 protein (Bcl2) reaction in most apparent neurons, indicating strong apoptotic changes. Treatment with Urchin extracts reversed these changes. Quantification of cerebral cortex neurons also revealed the strong effect of the extracts. Cisplatin treated groups showed 3708 cells/ mm3 compared to 8091 cells/mm3 in the normal rats. Extract treatment increased the neuronal numbers to almost normal levels. Quantification of the Immuno-histochemical expression of GFAP showed an increase by 10-folds after cisplatin administration. A remarkable decline from the cisplatin group was seen in the extract treated groups.In Conclusion, Sea Urchins extracts possess a strong neuroprotective activity and could provide a novel therapeutic method to prevent Cisplatin-induced neurotoxicity.
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Affiliation(s)
- Eman A Khalil
- Department of Biology, School of Sciences and Engineering, The American University in Cairo, Cairo, 11835, Egypt
| | - Hamdy Swelim
- Department of Zoology, Faculty of Science, Ain Shams University, Cairo, Egypt
| | - Hala El-Tantawi
- Department of Zoology, Faculty of Science, Ain Shams University, Cairo, Egypt
| | - Ahmed Abdellatif
- Department of Biology, School of Sciences and Engineering, The American University in Cairo, Cairo, 11835, Egypt.
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Simicic D, Cudalbu C, Pierzchala K. Overview of oxidative stress findings in hepatic encephalopathy: From cellular and ammonium-based animal models to human data. Anal Biochem 2022; 654:114795. [PMID: 35753389 DOI: 10.1016/j.ab.2022.114795] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 05/26/2022] [Accepted: 06/15/2022] [Indexed: 11/30/2022]
Abstract
Oxidative stress is a natural phenomenon in the body. Under physiological conditions intracellular reactive oxygen species (ROS) are normal components of signal transduction cascades, and their levels are maintained by a complex antioxidants systems participating in the in-vivo redox homeostasis. Increased oxidative stress is present in several chronic diseases and interferes with phagocytic and nervous cell functions, causing an up-regulation of cytokines and inflammation. Hepatic encephalopathy (HE) occurs in both acute liver failure (ALF) and chronic liver disease. Increased blood and brain ammonium has been considered as an important factor in pathogenesis of HE and has been associated with inflammation, neurotoxicity, and oxidative stress. The relationship between ROS and the pathophysiology of HE is still poorly understood. Therefore, sensing ROS production for a better understanding of the relationship between oxidative stress and functional outcome in HE pathophysiology is critical for determining the disease mechanisms, as well as to improve the management of patients. This review is emphasizing the important role of oxidative stress in HE development and documents the changes occurring as a consequence of oxidative stress augmentation based on cellular and ammonium-based animal models to human data.
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Affiliation(s)
- D Simicic
- CIBM Center for Biomedical Imaging, Switzerland; Animal Imaging and Technology, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland; Laboratory of Functional and Metabolic Imaging, EPFL, Lausanne, Switzerland
| | - C Cudalbu
- CIBM Center for Biomedical Imaging, Switzerland; Animal Imaging and Technology, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - K Pierzchala
- CIBM Center for Biomedical Imaging, Switzerland; Animal Imaging and Technology, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland; Laboratory of Functional and Metabolic Imaging, EPFL, Lausanne, Switzerland.
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7
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El Khiat A, El Hiba O, Tamegart L, Rais H, Fdil N, Sellami S, El Mokhtar MA, Gamrani H. Time dependent alteration of locomotor behavior in rat with acute liver failure induced cerebellar neuroinflammation and neuro-astroglial damage. J Chem Neuroanat 2021; 119:102055. [PMID: 34863855 DOI: 10.1016/j.jchemneu.2021.102055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 11/27/2021] [Accepted: 11/27/2021] [Indexed: 11/26/2022]
Abstract
Hepatic encephalopathy (HE) is a neurophysiological syndrome secondary to acute or chronic liver failure. Studies showed that HE patients exhibit a deficit in motor coordination, which may result from cerebellar functional impairment. The aim of this study is to assess the time-dependent alteration of locomotor behavior and the glial and neuronal alteration in rat with acute HE induced chemically. The study was carried out in male Sprague-Dawley rats with thioacetamide (TAA) induced acute liver failure at different stages 12 h, 24 h and 36 h. Hepatic and renal functions were assessed via various biochemical and histopathological examinations, while the cerebellum and the midbrain were examined using histology and immunohistochemistry for tyrosine hydroxylase (TH), cyclooxygenase-2 (COX-2) and glial fibrillary acidic protein (GFAP). We used as well, the open field test and the Rotarod test for assessing the locomotor activity and coordination. Our data showed a progressive loss of liver function and a progressive alteration in locomotor behavior and motor coordination in acute HE rats. In the cerebellum, we noted an increase in the degeneration of cerebellar Purkinje neurons parallel to increased COX-2 immunoreactivity together with astrocytic morphology and density changes. Likewise, in substantia nigra pars compacta, TH levels were reduced. We showed through the current study, a progressive deterioration in locomotor behavior in acute HE rats, as a result of Purkinje neurons death and a deficient dopaminergic neurotransmission, together with the morpho-functional astroglial modifications involving the oxidative stress and neuroinflammation.
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Affiliation(s)
- Abdelaati El Khiat
- Laboratory of Clinical and Experimental Neurosciences and Environment, faculty of Medicine and Pharmacy, Cadi Ayyad University, 4000 Marrakech, Morocco; Higher Institute of Nursing Professions and Health Techniques, Ouarzazate, Morocco.
| | - Omar El Hiba
- Nutritional Physiopathologies and Toxicology Team, faculty of Sciences, Chouaib Doukkali University, El Jadida, Morocco.
| | - Lahcen Tamegart
- Laboratory of Clinical and Experimental Neurosciences and Environment, faculty of Medicine and Pharmacy, Cadi Ayyad University, 4000 Marrakech, Morocco; Department of Biology, Faculty of Science, Abdelmalek Essaadi University, Tetouan, Morocco
| | - Hanane Rais
- Laboratory of Morphosciences, Faculty of Medicine and Pharmacy, Cadi Ayyad University, Morocco; Mohammed VI University Hospital, Marrakech, Morocco
| | - Naima Fdil
- Metabolics platform, Biochemistry Laboratory, Faculty of Medicine, Cadi Ayyad University, Sidi Abbad, BP 40000 Marrakech, Morocco
| | | | - Mohamed Ait El Mokhtar
- Laboratory of Biochemistry, Environment &Agri-food URAC 36, Department of Biology, Faculty of Sciences and Techniques, Mohmmedia, Hassan II University of Casablanca, Morocco
| | - Halima Gamrani
- Laboratory of Clinical and Experimental Neurosciences and Environment, faculty of Medicine and Pharmacy, Cadi Ayyad University, 4000 Marrakech, Morocco.
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Claeys W, Van Hoecke L, Lefere S, Geerts A, Verhelst X, Van Vlierberghe H, Degroote H, Devisscher L, Vandenbroucke RE, Van Steenkiste C. The neurogliovascular unit in hepatic encephalopathy. JHEP Rep 2021; 3:100352. [PMID: 34611619 PMCID: PMC8476774 DOI: 10.1016/j.jhepr.2021.100352] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 07/14/2021] [Accepted: 07/23/2021] [Indexed: 12/14/2022] Open
Abstract
Hepatic encephalopathy (HE) is a neurological complication of hepatic dysfunction and portosystemic shunting. It is highly prevalent in patients with cirrhosis and is associated with poor outcomes. New insights into the role of peripheral origins in HE have led to the development of innovative treatment strategies like faecal microbiota transplantation. However, this broadening of view has not been applied fully to perturbations in the central nervous system. The old paradigm that HE is the clinical manifestation of ammonia-induced astrocyte dysfunction and its secondary neuronal consequences requires updating. In this review, we will use the holistic concept of the neurogliovascular unit to describe central nervous system disturbances in HE, an approach that has proven instrumental in other neurological disorders. We will describe HE as a global dysfunction of the neurogliovascular unit, where blood flow and nutrient supply to the brain, as well as the function of the blood-brain barrier, are impaired. This leads to an accumulation of neurotoxic substances, chief among them ammonia and inflammatory mediators, causing dysfunction of astrocytes and microglia. Finally, glymphatic dysfunction impairs the clearance of these neurotoxins, further aggravating their effect on the brain. Taking a broader view of central nervous system alterations in liver disease could serve as the basis for further research into the specific brain pathophysiology of HE, as well as the development of therapeutic strategies specifically aimed at counteracting the often irreversible central nervous system damage seen in these patients.
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Key Words
- ABC, ATP-binding cassette
- ACLF, acute-on-chronic liver failure
- AD, acute decompensation
- ALF, acute liver failure
- AOM, azoxymethane
- AQP4, aquaporin 4
- Acute Liver Failure
- Ammonia
- BBB, blood-brain barrier
- BCRP, breast cancer resistance protein
- BDL, bile duct ligation
- Blood-brain barrier
- Brain edema
- CCL, chemokine ligand
- CCR, C-C chemokine receptor
- CE, cerebral oedema
- CLD, chronic liver disease
- CLDN, claudin
- CNS, central nervous system
- CSF, cerebrospinal fluid
- Cirrhosis
- Energy metabolism
- GS, glutamine synthetase
- Glymphatic system
- HE, hepatic encephalopathy
- HO-1, heme oxygenase 1
- IL-, interleukin
- MMP-9, matrix metalloproteinase 9
- MRP, multidrug resistance associated protein
- NGVU
- NGVU, neurogliovascular unit
- NKCC1, Na-K-2Cl cotransporter 1
- Neuroinflammation
- OCLN, occludin
- ONS, oxidative and nitrosative stress
- Oxidative stress
- P-gp, P-glycoprotein
- PCA, portacaval anastomosis
- PSS, portosystemic shunt
- S1PR2, sphingosine-1-phosphate receptor 2
- SUR1, sulfonylurea receptor 1
- Systemic inflammation
- TAA, thioacetamide
- TGFβ, transforming growth factor beta
- TJ, tight junction
- TNF, tumour necrosis factor
- TNFR1, tumour necrosis factor receptor 1
- ZO, zonula occludens
- mPT, mitochondrial pore transition
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Affiliation(s)
- Wouter Claeys
- Hepatology Research Unit, Department of Internal Medicine and Paediatrics, Liver Research Center Ghent, Ghent University, Ghent, Belgium
- Barriers in Inflammation, VIB Center for Inflammation Research, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Lien Van Hoecke
- Barriers in Inflammation, VIB Center for Inflammation Research, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Sander Lefere
- Hepatology Research Unit, Department of Internal Medicine and Paediatrics, Liver Research Center Ghent, Ghent University, Ghent, Belgium
- Gut-Liver Immunopharmacology Unit, Department of Basic and Applied Medical Sciences; Liver Research Center Ghent; Ghent University, Ghent, Belgium
| | - Anja Geerts
- Hepatology Research Unit, Department of Internal Medicine and Paediatrics, Liver Research Center Ghent, Ghent University, Ghent, Belgium
| | - Xavier Verhelst
- Hepatology Research Unit, Department of Internal Medicine and Paediatrics, Liver Research Center Ghent, Ghent University, Ghent, Belgium
| | - Hans Van Vlierberghe
- Hepatology Research Unit, Department of Internal Medicine and Paediatrics, Liver Research Center Ghent, Ghent University, Ghent, Belgium
| | - Helena Degroote
- Hepatology Research Unit, Department of Internal Medicine and Paediatrics, Liver Research Center Ghent, Ghent University, Ghent, Belgium
| | - Lindsey Devisscher
- Gut-Liver Immunopharmacology Unit, Department of Basic and Applied Medical Sciences; Liver Research Center Ghent; Ghent University, Ghent, Belgium
| | - Roosmarijn E. Vandenbroucke
- Barriers in Inflammation, VIB Center for Inflammation Research, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Christophe Van Steenkiste
- Antwerp University, Department of Gastroenterology and Hepatology, Antwerp, Belgium
- Department of Gastroenterology and Hepatology, Maria Middelares Hospital, Ghent, Belgium
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9
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Ochoa-Sanchez R, Tamnanloo F, Rose CF. Hepatic Encephalopathy: From Metabolic to Neurodegenerative. Neurochem Res 2021; 46:2612-2625. [PMID: 34129161 DOI: 10.1007/s11064-021-03372-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Revised: 05/31/2021] [Accepted: 06/03/2021] [Indexed: 12/15/2022]
Abstract
Hepatic encephalopathy (HE) is a neuropsychiatric syndrome of both acute and chronic liver disease. As a metabolic disorder, HE is considered to be reversible and therefore is expected to resolve following the replacement of the diseased liver with a healthy liver. However, persisting neurological complications are observed in up to 47% of transplanted patients. Several retrospective studies have shown that patients with a history of HE, particularly overt-HE, had persistent neurological complications even after liver transplantation (LT). These enduring neurological conditions significantly affect patient's quality of life and continue to add to the economic burden of chronic liver disease on health care systems. This review discusses the journey of the brain through the progression of liver disease, entering the invasive surgical procedure of LT and the conditions associated with the post-transplant period. In particular, it will discuss the vulnerability of the HE brain to peri-operative factors and post-LT conditions which may explain non-resolved neurological impairment following LT. In addition, the review will provide evidence; (i) supporting overt-HE impacts on neurological complications post-LT; (ii) that overt-HE leads to permanent neuronal injury and (iii) the pathophysiological role of ammonia toxicity on astrocyte and neuronal injury/damage. Together, these findings will provide new insights on the underlying mechanisms leading to neurological complications post-LT.
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Affiliation(s)
- Rafael Ochoa-Sanchez
- Hepato-Neuro Laboratory, CRCHUM, Université de Montréal, 900, rue Saint-Denis Pavillon R, R08.422, Montreal, QC, H2X-0A9, Canada
| | - Farzaneh Tamnanloo
- Hepato-Neuro Laboratory, CRCHUM, Université de Montréal, 900, rue Saint-Denis Pavillon R, R08.422, Montreal, QC, H2X-0A9, Canada
| | - Christopher F Rose
- Hepato-Neuro Laboratory, CRCHUM, Université de Montréal, 900, rue Saint-Denis Pavillon R, R08.422, Montreal, QC, H2X-0A9, Canada.
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Hajipour S, Sarkaki A, Dianat M, Rashno M, Khorsandi LS, Farbood Y. The effects of thymoquinone on memory impairment and inflammation in rats with hepatic encephalopathy induced by thioacetamide. Metab Brain Dis 2021; 36:991-1002. [PMID: 33620578 DOI: 10.1007/s11011-021-00688-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 02/08/2021] [Indexed: 12/11/2022]
Abstract
Hepatic encephalopathy (HE) is a prevalent complication of the central nervous system (CNS) that is caused by acute or chronic liver failure. This study was designed to evaluate the effects of thymoquinone (TQ) on thioacetamide (TAA)-induced HE in rats, and determine the consequential behavioral, biochemical, and histological changes. HE was induced in male Wistar rats by intraperitoneal (i.p.) injection of 200 mg/kg TAA once every 48 h for 14 consecutive days. Control groups received the normal saline containing 5 % DMSO. Thymoquinone (5, 10, and 20 mg/kg) was administered for ten consecutive days intraperitoneally (i.p.) after HE induction and it was continued until the end of the tests. Then, the passive avoidance memory, extracellular single unit, BBB permeability, and brain water content were evaluated. Moreover, hippocampal tissues were used for evaluation of oxidative stress index, inflammatory biomarkers, and histological parameters following HE. As result of the treatment, TQ improved passive avoidance memory, increased the average number of simultaneous firing of spikes/bins, improved the integrity of BBB, and decreased brain water content in the animal model of HE. Furthermore, the results indicated that treatment with TQ decreased the levels of inflammatory cytokines (TNF-α and IL-1β) but increased the levels of glutathione (GSH) and anti-inflammatory cytokine (IL-10) of the surviving cells in the hippocampal tissues. This study demonstrates that TQ may have beneficial therapeutic effects on cognitive, oxidative stress, neuroinflammatory, and histological complications of HE in rat.
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Affiliation(s)
- Somayeh Hajipour
- Persian Gulf Physiology Research Center, Medical Basic Sciences Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Alireza Sarkaki
- Persian Gulf Physiology Research Center, Medical Basic Sciences Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
- Department of Physiology, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
- Medicinal Plant Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Mahin Dianat
- Persian Gulf Physiology Research Center, Medical Basic Sciences Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
- Department of Physiology, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Mohammad Rashno
- Department of Immunology, Faculty of Medicine, Cellular & Molecular Research Center, Medical Basic Sciences Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Laaya Sadat Khorsandi
- Department of Anatomical Sciences, Cellular & Molecular Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Yaghoob Farbood
- Persian Gulf Physiology Research Center, Medical Basic Sciences Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
- Department of Physiology, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
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11
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Chen MH, Wang TJ, Chen LJ, Jiang MY, Wang YJ, Tseng GF, Chen JR. The effects of astaxanthin treatment on a rat model of Alzheimer's disease. Brain Res Bull 2021; 172:151-163. [PMID: 33932491 DOI: 10.1016/j.brainresbull.2021.04.020] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 04/03/2021] [Accepted: 04/25/2021] [Indexed: 01/16/2023]
Abstract
Alzheimer's disease (AD), a progressive neurodegenerative disorder characterized by memory loss and dementia, could be a consequence of the abnormalities of cortical milieu, such as oxidative stress, inflammation, and/or accompanied with the aggregation of β-amyloid. The majority of AD patients are sporadic, late-onset AD, which predominantly occurs over 65 years of age. Our results revealed that the ferrous amyloid buthionine (FAB)-infused sporadic AD-like model showed deficits in spatial learning and memory and with apparent loss of choline acetyltransferase (ChAT) expression in medial septal (MS) nucleus. In hippocampal CA1 region, the loss of pyramidal neurons was accompanied with cholinergic fiber loss and neuroinflammatory responses including glial reaction and enhanced expression of inducible nitric oxide synthase (iNOS). Surviving hippocampal CA1 pyramidal neurons showed the reduction of dendritic spines as well. Astaxanthin (ATX), a potent antioxidant, reported to improve the outcome of oxidative-stress-related diseases. The ATX treatment in FAB-infused rats decreased neuroinflammation and restored the ChAT + fibers in hippocampal CA1 region and the ChAT expression in MS nucleus. It also partly recovered the spine loss on hippocampal CA1 pyramidal neurons and ameliorated the behavioral deficits in AD-like rats. From these data, we believed that the ATX can be a potential option for slowing the progression of Alzheimer's disease.
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Affiliation(s)
- Mu-Hsuan Chen
- Ph.D. Program in Tissue Engineering and Regenerative Medicine, National Chung-Hsing University, Taichung, Taiwan
| | - Tsyr-Jiuan Wang
- Department of Nursing, National Taichung University of Science and Technology, Taichung, Taiwan
| | - Li-Jin Chen
- Department of Anatomy, College of Medicine, Tzu-Chi University, Hualien, Taiwan
| | - Ming-Ying Jiang
- Department of Veterinary Medicine, College of Veterinary Medicine, National Chung-Hsing University, Taichung, Taiwan
| | - Yueh-Jan Wang
- Department of Anatomy, College of Medicine, Tzu-Chi University, Hualien, Taiwan
| | - Guo-Fang Tseng
- Department of Anatomy, College of Medicine, Tzu-Chi University, Hualien, Taiwan.
| | - Jeng-Rung Chen
- Ph.D. Program in Tissue Engineering and Regenerative Medicine, National Chung-Hsing University, Taichung, Taiwan; Department of Veterinary Medicine, College of Veterinary Medicine, National Chung-Hsing University, Taichung, Taiwan.
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12
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Sun X, Lv Y, Huang L, Gao H, Ren C, Li J, Bie M, Li W, Koike K, So KF, Xiao J. Pro-inflammatory cytokines serve as communicating molecules between the liver and brain for hepatic encephalopathy pathogenesis and Lycium barbarum polysaccharides protection. JOURNAL OF ETHNOPHARMACOLOGY 2020; 248:112357. [PMID: 31693919 DOI: 10.1016/j.jep.2019.112357] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 10/22/2019] [Accepted: 10/24/2019] [Indexed: 06/10/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Gogi berry is a traditional food supplement and medical herbal which has been widely used in Eastern Asian countries. Lycium barbarum polysaccharides (LBP) are the major active components of Gogi berry and have been proved to possess a lot of biological activities. AIM OF THE STUDY We aimed to delineate the protective effect and mechanism of LBP on hepatic encephalopathy (HE). MATERIALS AND METHODS We investigated the protective mechanism of LBP in a thioacetamide (TAA, intraperitoneally injected, 400 mg/kg) induced acute HE mice model. Key phenotypes of clinical HE were phenocopied in the mice model, including high mortality, severe hepatic histology injury, increased hepatic oxidative stress, apoptosis, enhanced circulating levels of pro-inflammatory cytokines and ammonia, suppressed tryptophan hydroxylase activity, and deficits in locomotor activity. RESULTS The pathological alterations were effectively ameliorated by the oral administration with LBP (5 mg/kg, oral gavage, everyday), which were mediated by regulating MAPK pathways in both the liver and brain. Knockout of pro-inflammatory cytokines TNF-α or IL-6 effectively ameliorated impaired mice locomotor activity and MAPK activation in the brain. In an in vitro TNF-α-, IL-6-, or ammonia-induced microglia damaged cell model, cell injuries were evidently protected by the co-administration with LBP (50 μg/ml). CONCLUSION LBP ameliorated the hepatic/brain injuries and impaired locomotor activities in a HE mice model. Pro-inflammatory cytokines may serve as communicating molecules linking the liver and brain for the HE pathogenesis, partly through MAPK regulation.
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Affiliation(s)
- Xiaoming Sun
- Center for Clinical Precision Medication, The First Affiliated Hospital, Guangdong Pharmaceutical University, Guangzhou, 510006, China; Clinical Pharmacy (School of Integrative Pharmacy, Institute of Integrative Pharmaceutical Research), Guangdong Pharmaceutical University, Guangzhou, 510006, China
| | - Yi Lv
- Laboratory of Neuroendocrinology, Fujian Key Laboratory of Developmental and Neurobiology, College of Life Sciences, Fujian Normal University, Fuzhou, 350007, China
| | - Lu Huang
- Guangdong-HongKong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou, 510632, China; Guangdong Key Laboratory of Brain Function and Diseases, Jinan University, Guangzhou, 510632, China
| | - Hao Gao
- College of Pharmacy, Jinan University, Guangzhou, 510632, China
| | - Chaoran Ren
- Guangdong-HongKong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou, 510632, China; Guangdong Key Laboratory of Brain Function and Diseases, Jinan University, Guangzhou, 510632, China
| | - Jingjing Li
- Guangdong-HongKong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou, 510632, China; Guangdong Key Laboratory of Brain Function and Diseases, Jinan University, Guangzhou, 510632, China
| | - Man Bie
- Guangdong-HongKong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou, 510632, China; Guangdong Key Laboratory of Brain Function and Diseases, Jinan University, Guangzhou, 510632, China
| | - Wei Li
- Faculty of Pharmaceutical Sciences, Toho University, Chiba, Japan
| | - Kazuo Koike
- Faculty of Pharmaceutical Sciences, Toho University, Chiba, Japan
| | - Kwok-Fai So
- Laboratory of Neuroendocrinology, Fujian Key Laboratory of Developmental and Neurobiology, College of Life Sciences, Fujian Normal University, Fuzhou, 350007, China; Guangdong-HongKong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou, 510632, China; Guangdong Key Laboratory of Brain Function and Diseases, Jinan University, Guangzhou, 510632, China; Department of Ophthalmology, The University of Hong Kong, Pokfulam, Hong Kong, China.
| | - Jia Xiao
- Laboratory of Neuroendocrinology, Fujian Key Laboratory of Developmental and Neurobiology, College of Life Sciences, Fujian Normal University, Fuzhou, 350007, China; School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong, China; Institute of Clinical Medicine, The First Affiliated Hospital of Jinan University, Guangzhou, 510632, China.
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13
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Lin W, Chen X, Gao YQ, Yang ZT, Yang W, Chen HJ. Hippocampal atrophy and functional connectivity disruption in cirrhotic patients with minimal hepatic encephalopathy. Metab Brain Dis 2019; 34:1519-1529. [PMID: 31363985 DOI: 10.1007/s11011-019-00457-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 07/03/2019] [Indexed: 12/21/2022]
Abstract
The hippocampus is a crucial pathological node for minimal hepatic encephalopathy (MHE) and it is associated with various cognitive impairments. Investigations on alterations involving hippocampal morphology and functional connectivity (FC) in MHE are limited. This study aimed to simultaneously evaluate hippocampal volume and FC alterations and their association with cognitive decline in MHE. Twenty-two cirrhotic patients with MHE, 31 cirrhotic patients without MHE (NHE), and 43 healthy controls underwent high-resolution T1-weighted imaging, resting-state functional magnetic resonance imaging, and cognition assessment based on Psychometric Hepatic Encephalopathy Score (PHES). The structural images were preprocessed using a voxel-based morphometry method, during which hippocampal volume was measured. The hippocampal connectivity network was identified using seed-based correlation analysis. Hippocampal volume and FC strength were compared across the three groups and correlated against the PHES results of the cirrhotic patients. Compared to the controls, MHE patients exhibited a significantly lower bilateral hippocampal volume. A slight decrease in hippocampal volume was obtained from NHE to MHE, but it did not reach statistically significance. In addition, the average FC strength of the bilateral hippocampal connectivity network was significantly lower in the MHE patients. In particular, the MHE patients showed a decrease in FC involving the left hippocampus to bilateral posterior cingulate gyrus and left angular gyrus. The MHE patients also showed FC reduction between the right hippocampus and bilateral medial frontal cortex. A progressive reduction in hippocampal FC from NHE to MHE was also observed. The bilateral hippocampal FC strength (but not hippocampal volume) was positively correlated with the PHES results of the cirrhotic patients. Our assessment of MHE patients revealed decreased hippocampal volume, which suggests regional atrophy, and reduced hippocampal connectivity with regions that are primarily involved in the default-mode network, thereby suggesting a functional disconnection syndrome. These alterations reveal the mechanisms underlying cognitive deterioration with disease progression.
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Affiliation(s)
- Weiwen Lin
- Department of Radiology, Fujian Medical University Union Hospital, Fuzhou, 350001, China
| | - Xuhui Chen
- Department of Radiology, Fujian Medical University Union Hospital, Fuzhou, 350001, China
| | | | - Zhe-Ting Yang
- Department of Radiology, Fujian Medical University Union Hospital, Fuzhou, 350001, China
| | - Weizhu Yang
- Department of Interventional Radiology, Fujian Medical University Union Hospital, Fuzhou, 350001, China.
| | - Hua-Jun Chen
- Department of Radiology, Fujian Medical University Union Hospital, Fuzhou, 350001, China.
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14
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Groiss SJ, Butz M, Baumgarten TJ, Füllenbach ND, Häussinger D, Schnitzler A. GABA-ergic tone hypothesis in hepatic encephalopathy – Revisited. Clin Neurophysiol 2019; 130:911-916. [DOI: 10.1016/j.clinph.2019.03.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Revised: 02/27/2019] [Accepted: 03/22/2019] [Indexed: 12/23/2022]
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15
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Farhoodi R, Lansdell BJ, Kording KP. Quantifying How Staining Methods Bias Measurements of Neuron Morphologies. Front Neuroinform 2019; 13:36. [PMID: 31191283 PMCID: PMC6541099 DOI: 10.3389/fninf.2019.00036] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2018] [Accepted: 04/25/2019] [Indexed: 12/20/2022] Open
Abstract
The process through which neurons are labeled is a key methodological choice in measuring neuron morphology. However, little is known about how this choice may bias measurements. To quantify this bias we compare the extracted morphology of neurons collected from the same rodent species, experimental condition, gender distribution, age distribution, brain region and putative cell type, but obtained with 19 distinct staining methods. We found strong biases on measured features of morphology. These were largest in features related to the coverage of the dendritic tree (e.g., the total dendritic tree length). Understanding measurement biases is crucial for interpreting morphological data.
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Affiliation(s)
- Roozbeh Farhoodi
- Department of Mathematics, Sharif University of Technology, Tehran, Iran
| | | | - Konrad Paul Kording
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, United States.,Department of Neuroscience, University of Pennsylvania, Philadelphia, PA, United States
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16
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Golshani M, Basiri M, Shabani M, Aghaei I, Asadi-Shekaari M. Effects of erythropoietin on bile duct ligation-induced neuro-inflammation in male rats. AIMS Neurosci 2019; 6:43-53. [PMID: 32341967 PMCID: PMC7179341 DOI: 10.3934/neuroscience.2019.2.43] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Accepted: 03/18/2019] [Indexed: 01/11/2023] Open
Abstract
Hepatic encephalopathy (HE) is a brain disorder as a result of liver failure. Previous studies have indicated that erythropoietin (EPO) has neuroprotective effects in different neurological diseases. This study addressed the therapeutic effect of a four-week treatment with EPO on neuronal damages in bile duct-ligated rats. Forty male Wistar rats (250-280 g) were used in the present study. The animals were randomly divided into four groups consisting of 10 animals each, including sham, sham + EPO, bile duct ligation (BDL), and BDL + EPO. EPO was intraperitoneally administered every other day (5,000 U/Kg) in the last four weeks after BDL. Biochemical and histological studies were performed to evaluate neurodegeneration. The results revealed that BDL increases the level of hepatic enzymes and total bilirubin. Furthermore, neurodegeneration was significantly increased in the BDL group compared to sham groups. EPO preserved hepatic enzymes and total bilirubin in the treated group. In addition, EPO significantly decreased the neurodegeneration in BDL + EPO compared to the BDL group. Results of this study showed that EPO has neuroprotective effects in the rat model of HE, possibly due to its anti-inflammatory and anti-oxidant properties. Complementary studies are required to clarify the exact mechanisms.
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Affiliation(s)
- Moazameh Golshani
- Department of Anatomical Sciences, Afzalipour School of Medicine, Kerman University of Medical Sciences, Kerman, Iran
| | - Mohsen Basiri
- Neuroscience Research Center, Neuropharmacology Institute, Kerman University of Medical Sciences, Kerman, Iran
| | - Mohammad Shabani
- Neuroscience Research Center, Neuropharmacology Institute, Kerman University of Medical Sciences, Kerman, Iran
| | - Iraj Aghaei
- Neuroscience Research Center, Poursina Hospital, Guilan University of Medical Sciences, Rasht, Iran
| | - Majid Asadi-Shekaari
- Neuroscience Research Center, Neuropharmacology Institute, Kerman University of Medical Sciences, Kerman, Iran
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Keller D, Erö C, Markram H. Cell Densities in the Mouse Brain: A Systematic Review. Front Neuroanat 2018; 12:83. [PMID: 30405363 PMCID: PMC6205984 DOI: 10.3389/fnana.2018.00083] [Citation(s) in RCA: 198] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 09/20/2018] [Indexed: 11/29/2022] Open
Abstract
The mouse brain is the most extensively studied brain of all species. We performed an exhaustive review of the literature to establish our current state of knowledge on cell numbers in mouse brain regions, arguably the most fundamental property to measure when attempting to understand a brain. The synthesized information, collected in one place, can be used by both theorists and experimentalists. Although for commonly-studied regions cell densities could be obtained for principal cell types, overall we know very little about how many cells are present in most brain regions and even less about cell-type specific densities. There is also substantial variation in cell density values obtained from different sources. This suggests that we need a new approach to obtain cell density datasets for the mouse brain.
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Affiliation(s)
- Daniel Keller
- Blue Brain Project, École Polytechnique Fédérale de Lausanne, Geneva, Switzerland
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18
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Duncan A, Klassen E, Srivastava A. Statistical shape analysis of simplified neuronal trees. Ann Appl Stat 2018. [DOI: 10.1214/17-aoas1107] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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19
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h-Type Membrane Current Shapes the Local Field Potential from Populations of Pyramidal Neurons. J Neurosci 2018; 38:6011-6024. [PMID: 29875266 DOI: 10.1523/jneurosci.3278-17.2018] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2017] [Revised: 04/17/2018] [Accepted: 05/01/2018] [Indexed: 12/23/2022] Open
Abstract
In cortex, the local field potential (LFP) is thought to mainly stem from correlated synaptic input to populations of geometrically aligned neurons. Computer models of single cortical pyramidal neurons showed that subthreshold voltage-dependent membrane conductances can also shape the LFP signal, in particular the hyperpolarization-activated cation current (Ih; h-type). This ion channel is prominent in various types of pyramidal neurons, typically showing an increasing density gradient along the apical dendrites. Here, we investigate how Ih affects the LFP generated by a model of a population of cortical pyramidal neurons. We find that the LFP from populations of neurons that receive uncorrelated synaptic input can be well predicted by the LFP from single neurons. In this case, when input impinges on the distal dendrites, where most h-type channels are located, a strong resonance in the LFP was measured near the soma, whereas the opposite configuration does not reveal an Ih contribution to the LFP. Introducing correlations in the synaptic inputs to the pyramidal cells strongly amplifies the LFP, while maintaining the differential effects of Ih for distal dendritic versus perisomatic input. Previous theoretical work showed that input correlations do not amplify LFP power when neurons receive synaptic input uniformly across the cell. We find that this crucially depends on the membrane conductance distribution: the asymmetric distribution of Ih results in a strong amplification of the LFP when synaptic inputs to the cell population are correlated. In conclusion, we find that the h-type current is particularly suited to shape the LFP signal in cortical populations.SIGNIFICANCE STATEMENT The local field potential (LFP), the low-frequency part of extracellular potentials recorded in neural tissue, is often used for probing neural circuit activity. While the cortical LFP is thought to mainly reflect synaptic inputs onto pyramidal neurons, little is known about the role of subthreshold active conductances in shaping the LFP. By means of biophysical modeling we obtain a comprehensive, qualitative understanding of how LFPs generated by populations of cortical pyramidal neurons depend on active subthreshold currents, and identify the key importance of the h-type channel. Our results show that LFPs can give information about the active properties of neurons and that preferred frequencies in the LFP can result from those cellular properties instead of, for example, network dynamics.
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Dhanda S, Gupta S, Halder A, Sunkaria A, Sandhir R. Systemic inflammation without gliosis mediates cognitive deficits through impaired BDNF expression in bile duct ligation model of hepatic encephalopathy. Brain Behav Immun 2018. [PMID: 29518527 DOI: 10.1016/j.bbi.2018.03.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Chronic liver disease per se induces neuroinflammation that contributes to cognitive deficits in hepatic encephalopathy (HE). However, the processes by which pro-inflammatory molecules result in cognitive impairment still remains unclear. In the present study, a significant increase in the activity of liver function enzymes viz. alanine transaminase (ALT), aspartate transaminase (AST) and alkaline phosphatase (ALP) was observed along with increase in plasma ammonia levels after four weeks of bile duct ligation (BDL) in rats suggesting hepatocellular damage. A significant increase was observed in mRNA expression of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α) and monocyte chemoattractant protein-1 (MCP-1) in brain regions and liver of BDL rats. Concomitantly, IL-6, TNF-α and MCP-1 protein levels were also increased in brain regions, liver and serum of BDL rats suggesting the involvement of blood-brain-axis in inflammatory response. However, a significant decrease was observed in glial fibrillary acidic protein (GFAP) and ionized calcium-binding adaptor molecule-1 (Iba-1) expression at transcriptional and translation level in brain of BDL rats. Immunohistochemical and flowcytometric analysis revealed reduced number of GFAP-immunopositive astrocytes and Iba1-immunopositive microglia in the brain regions of BDL rats. Further, a significant decline was observed in cognitive functions in BDL rats assessed using Morris water maze and novel object recognition tests. Expression of pro and mature form of brain derived neurotrophic factor (BDNF) and its upstream transcription element showed significant reduction in brain of BDL rats. Taken together, the results of the present study suggest that systemic inflammation and reduced expression of BDNF and its upstream transcription factor plays a key role in cognitive decline in HE.
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Affiliation(s)
- Saurabh Dhanda
- Department of Biochemistry, Basic Medical Sciences Block-II, Sector-25, Panjab University, Chandigarh 160014, India
| | - Smriti Gupta
- Department of Biochemistry, Basic Medical Sciences Block-II, Sector-25, Panjab University, Chandigarh 160014, India
| | - Avishek Halder
- Department of Biochemistry, Basic Medical Sciences Block-II, Sector-25, Panjab University, Chandigarh 160014, India
| | - Aditya Sunkaria
- Department of Biochemistry, Basic Medical Sciences Block-II, Sector-25, Panjab University, Chandigarh 160014, India
| | - Rajat Sandhir
- Department of Biochemistry, Basic Medical Sciences Block-II, Sector-25, Panjab University, Chandigarh 160014, India.
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Jiang X, Xu L, Tang L, Liu F, Chen Z, Zhang J, Chen L, Pang C, Yu X. Role of the indoleamine-2,3-dioxygenase/kynurenine pathway of tryptophan metabolism in behavioral alterations in a hepatic encephalopathy rat model. J Neuroinflammation 2018; 15:3. [PMID: 29301550 PMCID: PMC5753541 DOI: 10.1186/s12974-017-1037-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 12/12/2017] [Indexed: 01/08/2023] Open
Abstract
Background This study aims to explore the role of indoleamine-2,3-dioxygenase (IDO)/kynurenine (KYN) pathway of tryptophan (TRY) metabolism in behavioral alterations observed in hepatic encephalopathy (HE) rats. Methods Expression levels of proinflammatory cytokines were tested by QT-PCR and ELISA, levels of IDOs were tested by QT-PCR and Western blot, and levels of 5-hydroxytryptamine (5-HT), KYN, TRY, 3-hydroxykynurenine (3-HK), and kynurenic acid (KA) in different brain regions were estimated using HPLC. Effects of the IDO direct inhibitor 1-methyl-l-tryptophan (1-MT) on cognitive, anxiety, and depressive-like behavior were evaluated in bile duct ligation (BDL) rats. Results Increased serum TNF-α, IL-1β, and IL-6 levels were shown in rats 7 days after BDL, and these increases were observed earlier than those in the brain, indicating peripheral immune activation may result in central upregulation of proinflammatory cytokines. Moreover, BDL rats showed a progressive decline in memory formation, as well as anxiety and depressive-like behavior. Further study revealed that IDO expression increased after BDL, accompanied by a decrease of 5-HT and an increase of KYN, as well as abnormal expression of 3-HK and KA. The above results affected by BDL surgery were reversed by IDO inhibitor 1-MT treatment. Conclusion Taken together, these findings indicate that (1) behavioral impairment in BDL rats is correlated with proinflammatory cytokines; (2) TRY pathway of KYN metabolism, activated by inflammation, may play an important role in HE development; and (3) 1-MT may serve as a therapeutic agent for HE. Electronic supplementary material The online version of this article (10.1186/s12974-017-1037-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xi Jiang
- Department of Pharmacy, Zhejiang Pharmaceutical College, Ningbo, Zhejiang Province, 315000, China. .,Mingzhou Hospital, Zhejiang University, Hangzhou, Zhejiang Province, 315000, China.
| | - Lexing Xu
- Department of Pharmacy, Zhejiang Pharmaceutical College, Ningbo, Zhejiang Province, 315000, China
| | - Lin Tang
- Department of Pharmacy, Zhejiang Pharmaceutical College, Ningbo, Zhejiang Province, 315000, China
| | - Fuhe Liu
- Department of Pharmacy, Zhejiang Pharmaceutical College, Ningbo, Zhejiang Province, 315000, China
| | - Ziwei Chen
- Department of Pharmacy, Zhejiang Pharmaceutical College, Ningbo, Zhejiang Province, 315000, China
| | - Jiajia Zhang
- Department of Pharmacy, Zhejiang Pharmaceutical College, Ningbo, Zhejiang Province, 315000, China
| | - Lei Chen
- Department of Pharmacy, Zhejiang Pharmaceutical College, Ningbo, Zhejiang Province, 315000, China
| | - Cong Pang
- Department of Neurosurgery, Huai'an First People's Hospital, Nanjing Medical University, Nanjing, Jiangsu Province, 223001, China.
| | - Xuefeng Yu
- Department of Pharmacy, Zhejiang Pharmaceutical College, Ningbo, Zhejiang Province, 315000, China.
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22
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Jeong JH, Kim DK, Lee NS, Jeong YG, Kim HW, Kim JS, Han SY. Neuroprotective Effect of Nortriptyline in Overt Hepatic Encephalopathy Through Attenuation of Mitochondrial Dysfunction. ASN Neuro 2018; 10:1759091418810583. [PMID: 30428281 PMCID: PMC6238202 DOI: 10.1177/1759091418810583] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 09/21/2018] [Accepted: 10/01/2018] [Indexed: 12/12/2022] Open
Abstract
Hyperammonemia associated with overt hepatic encephalopathy (OHE) causes excitotoxic neuronal death through activation of the cytochrome C (CytC)-mediated mitochondria-dependent apoptotic pathway. We tested the therapeutic effect of nortriptyline (NT), a mitochondrial permeability transition pore (mPTP) blocker that can possibly inhibit mitochondrial CytC efflux to the cytosol on in vivo and in vitro OHE models. After ensuring the generation of OHE rats, established by bile duct ligation (BDL), they were intraperitoneally administered either 20 mg/kg NT (i.e., BDL+NT) or another vehicle (i.e., BDL+VEH) for 14 days. Compared with the control, BDL+VEH showed an increment of motor deficits, cell death, synaptic loss, apoptosis, and mitochondria with aberrant morphology in substantia nigra compacta dopaminergic (DA-ergic) neurons. However, the extent was significantly reversed in BDL+NT. Subsequently, we studied the neuroprotective mechanism of NT using PC-12 cells, a DA-ergic cell line, which exposed glutamate used as an excitotoxin. Compared with the control, the cells exposed to 15 mM glutamate (i.e., GLU) showed incremental cell death, apoptosis, and demise in mitochondrial respiration. Importantly, efflux of CytC from mitochondria to cytosol and the dissipation of mitochondrial membrane potential (△Ψm), an indicator of mPTP opening, were prominent in GLU. However, compared with the GLU, the cells cotreated with 10 μM NT (i.e., GLU+NT) showed a significant reduction in the aforementioned phenomenon. Together, we concluded that NT can be used for OHE therapeutics, mitigating the excitotoxic death of substantia nigra compacta DA-ergic neurons via mPTP-associated mitochondrial dysfunction inhibition.
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Affiliation(s)
- Ji Heun Jeong
- Department of Anatomy, College of Medicine, Konyang University, Daejeon, South Korea
| | - Do Kyung Kim
- Department of Anatomy, College of Medicine, Konyang University, Daejeon, South Korea
| | - Nam-Seob Lee
- Department of Anatomy, College of Medicine, Konyang University, Daejeon, South Korea
| | - Young-Gil Jeong
- Department of Anatomy, College of Medicine, Konyang University, Daejeon, South Korea
| | - Ho Won Kim
- Myunggok Medical Research Institute, College of Medicine, Konyang University, Daejeon, South Korea
| | - Jong-Seok Kim
- Myunggok Medical Research Institute, College of Medicine, Konyang University, Daejeon, South Korea
| | - Seung-Yun Han
- Department of Anatomy, College of Medicine, Konyang University, Daejeon, South Korea
- Myunggok Medical Research Institute, College of Medicine, Konyang University, Daejeon, South Korea
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Tóth K, Hofer KT, Kandrács Á, Entz L, Bagó A, Erőss L, Jordán Z, Nagy G, Sólyom A, Fabó D, Ulbert I, Wittner L. Hyperexcitability of the network contributes to synchronization processes in the human epileptic neocortex. J Physiol 2017; 596:317-342. [PMID: 29178354 DOI: 10.1113/jp275413] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 11/15/2017] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Hyperexcitability and hypersynchrony of neuronal networks are thought to be linked to the generation of epileptic activity in both humans and animal models. Here we show that human epileptic postoperative neocortical tissue is able to generate two different types of synchronies in vitro. Epileptiform bursts occurred only in slices derived from epileptic patients and were hypersynchronous events characterized by high levels of excitability. Spontaneous population activity emerged in both epileptic and non-epileptic tissue, with a significantly lower degree of excitability and synchrony, and could not be linked to epilepsy. These results help us to understand better the role of excitatory and inhibitory neuronal circuits in the generation of population events, and to define the subtle border between physiological and pathological synchronies. ABSTRACT Interictal activity is a hallmark of epilepsy diagnostics and is linked to neuronal hypersynchrony. Little is known about perturbations in human epileptic neocortical microcircuits, and their role in generating pathological synchronies. To explore hyperexcitability of the human epileptic network, and its contribution to convulsive activity, we investigated an in vitro model of synchronous burst activity spontaneously occurring in postoperative tissue slices derived from patients with or without preoperative clinical and electrographic manifestations of epileptic activity. Human neocortical slices generated two types of synchronies. Interictal-like discharges (classified as epileptiform events) emerged only in epileptic samples, and were hypersynchronous bursts characterized by considerably elevated levels of excitation. Synchronous population activity was initiated in both epileptic and non-epileptic tissue, with a significantly lower degree of excitability and synchrony, and could not be linked to epilepsy. However, in pharmacoresistant epileptic tissue, a higher percentage of slices exhibited population activity, with higher local field potential gradient amplitudes. More intracellularly recorded neurons received depolarizing synaptic potentials, discharging more reliably during the events. Light and electron microscopic examinations showed slightly lower neuron densities and higher densities of excitatory synapses in the human epileptic neocortex. Our data suggest that human neocortical microcircuits retain their functionality and plasticity in vitro, and can generate two significantly different synchronies. We propose that population bursts might not be pathological events while interictal-like discharges may reflect the epileptogenicity of the human cortex. Our results show that hyperexcitability characterizes the human epileptic neocortical network, and that it is closely related to the emergence of synchronies.
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Affiliation(s)
- Kinga Tóth
- Institute of Cognitive Neuroscience and Psychology, Research Center for Natural Sciences, Hungarian Academy of Sciences, 1117, Budapest, Hungary.,Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083, Budapest, Hungary
| | - Katharina T Hofer
- Institute of Cognitive Neuroscience and Psychology, Research Center for Natural Sciences, Hungarian Academy of Sciences, 1117, Budapest, Hungary.,Department of Information Technology, Pázmány Péter Catholic University, 1083, Budapest, Hungary
| | - Ágnes Kandrács
- Institute of Cognitive Neuroscience and Psychology, Research Center for Natural Sciences, Hungarian Academy of Sciences, 1117, Budapest, Hungary.,Department of Information Technology, Pázmány Péter Catholic University, 1083, Budapest, Hungary
| | - László Entz
- National Institute of Clinical Neuroscience, 1145, Budapest, Hungary
| | - Attila Bagó
- National Institute of Clinical Neuroscience, 1145, Budapest, Hungary
| | - Loránd Erőss
- National Institute of Clinical Neuroscience, 1145, Budapest, Hungary
| | - Zsófia Jordán
- National Institute of Clinical Neuroscience, 1145, Budapest, Hungary
| | - Gábor Nagy
- National Institute of Clinical Neuroscience, 1145, Budapest, Hungary
| | - András Sólyom
- National Institute of Clinical Neuroscience, 1145, Budapest, Hungary
| | - Dániel Fabó
- National Institute of Clinical Neuroscience, 1145, Budapest, Hungary
| | - István Ulbert
- Institute of Cognitive Neuroscience and Psychology, Research Center for Natural Sciences, Hungarian Academy of Sciences, 1117, Budapest, Hungary.,Department of Information Technology, Pázmány Péter Catholic University, 1083, Budapest, Hungary.,National Institute of Clinical Neuroscience, 1145, Budapest, Hungary
| | - Lucia Wittner
- Institute of Cognitive Neuroscience and Psychology, Research Center for Natural Sciences, Hungarian Academy of Sciences, 1117, Budapest, Hungary.,Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083, Budapest, Hungary.,National Institute of Clinical Neuroscience, 1145, Budapest, Hungary
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24
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Mendes NF, Mariotti FFN, de Andrade JS, de Barros Viana M, Céspedes IC, Nagaoka MR, Le Sueur-Maluf L. Lactulose decreases neuronal activation and attenuates motor behavioral deficits in hyperammonemic rats. Metab Brain Dis 2017; 32:2073-2083. [PMID: 28875419 DOI: 10.1007/s11011-017-0098-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 08/16/2017] [Indexed: 12/14/2022]
Abstract
Lactulose is a nonabsorbable disaccharide commonly used in clinical practice to treat hepatic encephalopathy. However, its effects on neuropsychiatric disorders and motor behavior have not been fully elucidated. Male Wistar rats were bile-duct ligated, and 3 weeks after surgery, treated with lactulose administrated by gavage (1.43 or 3.57 g/kg), once a day for seven days. Plasma levels of ammonia, aspartate aminotransferase, total bilirubin, and creatinine were quantified and histopathological analysis of the livers was performed. Locomotor activity measurements were performed in an open field. The expression of water channel aquaporin-4 was investigated and the analysis of Fos protein immunoreactivity was used to evaluate the pattern of neural activation in brain areas related to motor behavior. Bile-duct ligated rats showed hyperammonemia, loss of liver integrity and function, impaired locomotor activity, reduced aquaporin-4 protein expression, and neuronal hyperactivity. Lactulose treatment was able to reduce ammonia plasma levels, despite not having an effect on biochemical parameters of liver function, such as aspartate aminotransferase activity and total bilirubin levels, or on the cirrhotic hepatic architecture. Lactulose was also able to reduce the locomotor activity impairments and to mitigate or reverse most changes in neuronal activation. Lactulose had no effect on reduced aquaporin-4 protein expression. Our findings confirm the effectiveness of lactulose in reducing hyperammonemia and neuronal hyperactivity in brain areas related to motor behavior, reinforcing the importance of its clinical use in the treatment of the symptoms of cirrhosis-associated encephalopathy.
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Affiliation(s)
- Natália Ferreira Mendes
- Departmento de Biociências, Universidade Federal de São Paulo, UNIFESP, 133/136 - Vila Mathias, Santos/SP, 11015-020, Brazil
- Laboratório de Sinalização Celular, Universidade Estadual de Campinas, UNICAMP, Campinas/SP, 13083-864, Brazil
| | - Flora França Nogueira Mariotti
- Departmento de Biociências, Universidade Federal de São Paulo, UNIFESP, 133/136 - Vila Mathias, Santos/SP, 11015-020, Brazil
| | - José Simões de Andrade
- Departmento de Biociências, Universidade Federal de São Paulo, UNIFESP, 133/136 - Vila Mathias, Santos/SP, 11015-020, Brazil
| | - Milena de Barros Viana
- Departmento de Biociências, Universidade Federal de São Paulo, UNIFESP, 133/136 - Vila Mathias, Santos/SP, 11015-020, Brazil
| | - Isabel Cristina Céspedes
- Departmento de Biociências, Universidade Federal de São Paulo, UNIFESP, 133/136 - Vila Mathias, Santos/SP, 11015-020, Brazil
- Departamento de Morfologia e Genética, Universidade Federal de São Paulo, UNIFESP, 11015-020, São Paulo/SP, 04023-900, Brazil
| | - Márcia Regina Nagaoka
- Departmento de Biociências, Universidade Federal de São Paulo, UNIFESP, 133/136 - Vila Mathias, Santos/SP, 11015-020, Brazil
| | - Luciana Le Sueur-Maluf
- Departmento de Biociências, Universidade Federal de São Paulo, UNIFESP, 133/136 - Vila Mathias, Santos/SP, 11015-020, Brazil.
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Giuseppe MD, Oliveri M, Morici M, Rossi G, Spadola F. Hepatic Encephalopathy in a Red-Tailed Boa ( Boa Constrictor Imperator ). J Exot Pet Med 2017. [DOI: 10.1053/j.jepm.2017.01.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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26
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Chen LJ, Wang YJ, Chen JR, Tseng GF. Hydrocephalus compacted cortex and hippocampus and altered their output neurons in association with spatial learning and memory deficits in rats. Brain Pathol 2016; 27:419-436. [PMID: 27411167 DOI: 10.1111/bpa.12414] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 07/04/2016] [Indexed: 12/29/2022] Open
Abstract
Hydrocephalus is a common neurological disorder in children characterized by abnormal dilation of cerebral ventricles as a result of the impairment of cerebrospinal fluid flow or absorption. Clinical presentation of hydrocephalus varies with chronicity and often shows cognitive dysfunction. Here we used a kaolin-induction method in rats and studied the effects of hydrocephalus on cerebral cortex and hippocampus, the two regions highly related to cognition. Hydrocephalus impaired rats' performance in Morris water maze task. Serial three-dimensional reconstruction from sections of the whole brain freshly froze in situ with skull shows that the volumes of both structures were reduced. Morphologically, pyramidal neurons of the somatosensory cortex and hippocampus appear to be distorted. Intracellular dye injection and subsequent three-dimensional reconstruction and analyses revealed that the dendritic arbors of layer III and V cortical pyramid neurons were reduced. The total dendritic length of CA1, but not CA3, pyramidal neurons was also reduced. Dendritic spine densities on both cortical and hippocampal pyramidal neurons were decreased, consistent with our concomitant findings that the expressions of both synaptophysin and postsynaptic density protein 95 were reduced. These cortical and hippocampal changes suggest reductions of excitatory connectivity, which could underlie the learning and memory deficits in hydrocephalus.
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Affiliation(s)
- Li-Jin Chen
- Department of Anatomy, College of Medicine, Tzu-Chi University, Hualien City, Taiwan
| | - Yueh-Jan Wang
- Department of Anatomy, College of Medicine, Tzu-Chi University, Hualien City, Taiwan
| | - Jeng-Rung Chen
- Department of Veterinary Medicine, College of Veterinary Medicine, National Chung-Hsing University, Taichung, Taiwan
| | - Guo-Fang Tseng
- Department of Anatomy, College of Medicine, Tzu-Chi University, Hualien City, Taiwan
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27
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Golaszewski S, Langthaler PB, Schwenker K, Florea C, Christova M, Brigo F, Trinka E, Nardone R. Abnormal cortical synaptic plasticity in minimal hepatic encephalopathy. Brain Res Bull 2016; 125:200-4. [DOI: 10.1016/j.brainresbull.2016.07.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 07/23/2016] [Accepted: 07/25/2016] [Indexed: 12/13/2022]
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28
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Kong X, Luo S, Wu JR, Wu S, De Cecco CN, Schoepf UJ, Spandorfer AJ, Wang CY, Tian Y, Chen HJ, Lu GM, Yang GF, Zhang LJ. (18)F-DPA-714 PET Imaging for Detecting Neuroinflammation in Rats with Chronic Hepatic Encephalopathy. Am J Cancer Res 2016; 6:1220-31. [PMID: 27279913 PMCID: PMC4893647 DOI: 10.7150/thno.15362] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 04/19/2016] [Indexed: 12/11/2022] Open
Abstract
Neuroinflammation is considered to be the pathogenesis of hepatic encephalopathy (HE), and imaging neuroinflammation is implicated in HE management. 11C-PK11195, a typical translocator protein (TSPO) radiotracer, is used for imaging neuroinflammation. However, it has inherent limitations, such as short half-life and limited availability. The purpose of this study was to demonstrate the efficiency of new generation TSPO radiotracer, 18F-DPA-714, in detecting and monitoring neuroinflammation of chronic HE. This study was divided into two parts. The first part compared 18F-DPA-714 and 11C-PK11195 radiotracers in ten HE induced rats [bile duct ligation (BDL) and fed hyperammonemic diet (HD)] and 6 control rats. The animal subjects underwent dynamic positron emission tomography (PET) during 2-day intervals. The 11C-PK11195 PET study showed no differences in whole brain average percent injected dose per gram (%ID/g) values at all time points (all P>0.05), while the 18F-DPA-714 PET study showed higher whole brain average %ID/g values in HE rats compared to control group rats at 900 s to 3300 s after injecting radiotracer (all P<0.05). The second part of the study evaluated the effectiveness of ibuprofen (IBU) treatment to chronic HE. Forty rats were classified into six groups, including Sham+normal saline (NS), Sham+IBU, BDL+NS, BDL+HD+NS, BDL+IBU, and BDL+HD+IBU groups. 18F-DPA-714 PET was used to image neuroinflammation. Whole and regional brain average %ID/g values, neurological features, inflammatory factors and activated microglia showed better in the IBU groups than in the NS groups (all P<0.05) and no difference was seen in the Sham groups compared to IBU groups (all P>0.05). In conclusion, this study demonstrated that 18F-DPA-714 is an ideal TPSO radiotracer for imaging neuroinflammation and monitoring anti-neuroinflammation treatment efficacy of chronic HE.
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29
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Hernandez-Rabaza V, Cabrera-Pastor A, Taoro-Gonzalez L, Gonzalez-Usano A, Agusti A, Balzano T, Llansola M, Felipo V. Neuroinflammation increases GABAergic tone and impairs cognitive and motor function in hyperammonemia by increasing GAT-3 membrane expression. Reversal by sulforaphane by promoting M2 polarization of microglia. J Neuroinflammation 2016; 13:83. [PMID: 27090509 PMCID: PMC4835883 DOI: 10.1186/s12974-016-0549-z] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2015] [Accepted: 04/11/2016] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Hyperammonemia induces neuroinflammation and increases GABAergic tone in the cerebellum which contributes to cognitive and motor impairment in hepatic encephalopathy (HE). The link between neuroinflammation and GABAergic tone remains unknown. New treatments reducing neuroinflammation and GABAergic tone could improve neurological impairment. The aims were, in hyperammonemic rats, to assess whether: (a) Enhancing endogenous anti-inflammatory mechanisms by sulforaphane treatment reduces neuroinflammation and restores learning and motor coordination. (b) Reduction of neuroinflammation by sulforaphane normalizes extracellular GABA and glutamate-NO-cGMP pathway and identify underlying mechanisms. (c) Identify steps by which hyperammonemia-induced microglial activation impairs cognitive and motor function and how sulforaphane restores them. METHODS We analyzed in control and hyperammonemic rats, treated or not with sulforaphane, (a) learning in the Y maze; (b) motor coordination in the beam walking; (c) glutamate-NO-cGMP pathway and extracellular GABA by microdialysis; (d) microglial activation, by analyzing by immunohistochemistry or Western blot markers of pro-inflammatory (M1) (IL-1b, Iba-1) and anti-inflammatory (M2) microglia (Iba1, IL-4, IL-10, Arg1, YM-1); and (e) membrane expression of the GABA transporter GAT-3. RESULTS Hyperammonemia induces activation of astrocytes and microglia in the cerebellum as assessed by immunohistochemistry. Hyperammonemia-induced neuroinflammation is associated with increased membrane expression of the GABA transporter GAT-3, mainly in activated astrocytes. This is also associated with increased extracellular GABA in the cerebellum and with motor in-coordination and impaired learning ability in the Y maze. Sulforaphane promotes polarization of microglia from the M1 to the M2 phenotype, reducing IL-1b and increasing IL-4, IL-10, Arg1, and YM-1 in the cerebellum. This is associated with astrocytes deactivation and normalization of GAT-3 membrane expression, extracellular GABA, glutamate-nitric oxide-cGMP pathway, and learning and motor coordination. CONCLUSIONS Neuroinflammation increases GABAergic tone in the cerebellum by increasing GAT-3 membrane expression. This impairs motor coordination and learning in the Y maze. Sulforaphane could be a new therapeutic approach to improve cognitive and motor function in hyperammonemia, hepatic encephalopathy, and other pathologies associated with neuroinflammation by promoting microglia differentiation from M1 to M2.
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Affiliation(s)
- Vicente Hernandez-Rabaza
- Laboratorio de Neurobiología, Centro Investigación Príncipe Felipe , Eduardo Primo Yúfera, 3, Valencia, 46012 Spain
| | - Andrea Cabrera-Pastor
- Laboratorio de Neurobiología, Centro Investigación Príncipe Felipe , Eduardo Primo Yúfera, 3, Valencia, 46012 Spain
| | - Lucas Taoro-Gonzalez
- Laboratorio de Neurobiología, Centro Investigación Príncipe Felipe , Eduardo Primo Yúfera, 3, Valencia, 46012 Spain
| | - Alba Gonzalez-Usano
- Laboratorio de Neurobiología, Centro Investigación Príncipe Felipe , Eduardo Primo Yúfera, 3, Valencia, 46012 Spain
| | - Ana Agusti
- Laboratorio de Neurobiología, Centro Investigación Príncipe Felipe , Eduardo Primo Yúfera, 3, Valencia, 46012 Spain
| | - Tiziano Balzano
- Laboratorio de Neurobiología, Centro Investigación Príncipe Felipe , Eduardo Primo Yúfera, 3, Valencia, 46012 Spain
| | - Marta Llansola
- Laboratorio de Neurobiología, Centro Investigación Príncipe Felipe , Eduardo Primo Yúfera, 3, Valencia, 46012 Spain
| | - Vicente Felipo
- Laboratorio de Neurobiología, Centro Investigación Príncipe Felipe , Eduardo Primo Yúfera, 3, Valencia, 46012 Spain
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Yadav SK, Gupta RK, Saraswat VA, Rangan M, Thomas MA, Rutella S, Danese S, Wang E, Marincola FM, Haris M. Reduced cortical thickness in patients with acute-on-chronic liver failure due to non-alcoholic etiology. J Transl Med 2015; 13:322. [PMID: 26444271 PMCID: PMC4596551 DOI: 10.1186/s12967-015-0679-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 09/24/2015] [Indexed: 12/30/2022] Open
Abstract
Background Acute-on-chronic liver failure (ACLF) is a form of liver disease with high short-term mortality. ACLF offers considerable potential to affect the cortical areas by significant tissue injury due to loss of neurons
and other supporting cells. We measured changes in cortical thickness and metabolites profile in ACLF patients following treatment, and compared it with those of age matched healthy volunteers. Methods For the cortical thickness analysis we performed whole brain high resolution T1-weighted magnetic resonance imaging (MRI) on 15 ACLF and 10 healthy volunteers at 3T clinical MR scanner. Proton MR Spectroscopy (1H MRS) was also performed to measure level of altered metabolites. Out of 15 ACLF patients 10 survived and underwent follow-up study after clinical recovery at 3 weeks. FreeSurfer program was used to quantify cortical thickness and LC- Model software was used to quantify absolute metabolites concentrations. Neuropsychological (NP) test was performed to assess the cognitive performance in follow-up ACLF patients compared to controls. Results Significantly reduced cortical thicknesses in multiple brain sites, and significantly decreased N-acetyl aspartate (NAA), myo-inositol (mI) and significantly increased glutamate/glutamine (glx) metabolites were observed in ACLF compared to those of controls at baseline study. Follow-up patients showed significant recovery in cortical thickness and Glx level, while NAA and mI were partially recovered compared to baseline study. When compared to controls, follow-up patients still showed reduced cortical thickness and altered metabolites level. Follow-up patients had abnormal neuropsychological (NP) scores compared to controls. Conclusions Neuronal loss as suggested by the reduced NAA, decreased cellular density due to increased cerebral hyperammonemia as supported by the increased glx level, and increased proinflammatory cytokines and free radicals may account for the reduced cortical thickness in ACLF patients. Presence of reduced cortical thickness, altered metabolites and abnormal NP test scores in post recovery subjects as compared to those of controls is associated with incomplete clinical recovery. The current imaging protocol can be easily implemented in clinical settings to evaluate and monitor brain tissue changes in patients with ACLF during the course of treatment.
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Affiliation(s)
- Santosh K Yadav
- Research Branch, Sidra Medical and Research Center, P.O. Box 26999, Doha, Qatar.
| | - Rakesh K Gupta
- Department of Radiology, Fortis Memorial Research Institute, Gurgaon, Haryana, India.
| | - Vivek A Saraswat
- Department of Gastroenterology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India.
| | - Murali Rangan
- Department of Gastroenterology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India.
| | - Michael A Thomas
- Department of Radiological Sciences, David Geffen School of Medicine at University of California at Los Angeles, Los Angeles, California, USA.
| | - Sergio Rutella
- Research Branch, Sidra Medical and Research Center, P.O. Box 26999, Doha, Qatar.
| | - Silvio Danese
- Department of Gastroenterology, IRCCS Humanitas Research Hospital, Milan, Italy.
| | - Ena Wang
- Research Branch, Sidra Medical and Research Center, P.O. Box 26999, Doha, Qatar.
| | | | - Mohammad Haris
- Research Branch, Sidra Medical and Research Center, P.O. Box 26999, Doha, Qatar.
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Bobermin LD, Wartchow KM, Flores MP, Leite MC, Quincozes-Santos A, Gonçalves CA. Ammonia-induced oxidative damage in neurons is prevented by resveratrol and lipoic acid with participation of heme oxygenase 1. Neurotoxicology 2015; 49:28-35. [PMID: 26003724 DOI: 10.1016/j.neuro.2015.05.005] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Revised: 05/14/2015] [Accepted: 05/15/2015] [Indexed: 12/29/2022]
Abstract
Ammonia is a metabolite that, at high concentrations, is implicated in neurological disorders, such as hepatic encephalopathy (HE), which is associated with acute or chronic liver failure. Astrocytes are considered the primary target of ammonia toxicity in the central nervous system (CNS) because glutamine synthetase (GS), responsible for ammonia metabolism in CNS, is an astrocytic enzyme. Thus, neuronal dysfunction has been associated as secondary to astrocytic impairment. However, we demonstrated that ammonia can induce direct effects on neuronal cells. The cell viability was decreased by ammonia in SH-SY5Y cells and cerebellar granule neurons. In addition, ammonia induced increased reactive oxygen species (ROS) production and decreased GSH intracellular content, the main antioxidant in CNS. As ammonia neurotoxicity is strongly associated with oxidative stress, we also investigated the potential neuroprotective roles of the antioxidants, resveratrol (RSV) and lipoic acid (LA), against ammonia toxicity in cerebellar granule neurons. RSV and LA were able to prevent the oxidative damage induced by ammonia, maintaining the levels of ROS production and GSH close to basal values. Both antioxidants also decreased ROS production and increased GSH content under basal conditions (in the absence of ammonia). Moreover, we showed that heme oxygenase 1 (HO1), a protein associated with protection against stress conditions, is involved in the beneficial effects of RSV and LA in cerebellar granule neurons. Thus, this study reinforces the neuroprotective effects of RSV and LA. Although more studies in vivo are required, RSV and LA could represent interesting therapeutic strategies for the management of HE.
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Affiliation(s)
- Larissa Daniele Bobermin
- Department of Biochemistry, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil.
| | - Krista Minéia Wartchow
- Department of Biochemistry, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Marianne Pires Flores
- Department of Biochemistry, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Marina Concli Leite
- Department of Biochemistry, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - André Quincozes-Santos
- Department of Biochemistry, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Carlos-Alberto Gonçalves
- Department of Biochemistry, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil
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Jayakumar AR, Rama Rao KV, Norenberg MD. Neuroinflammation in hepatic encephalopathy: mechanistic aspects. J Clin Exp Hepatol 2015; 5:S21-8. [PMID: 26041953 PMCID: PMC4442850 DOI: 10.1016/j.jceh.2014.07.006] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 07/08/2014] [Indexed: 12/12/2022] Open
Abstract
Hepatic encephalopathy (HE) is a major neurological complication of severe liver disease that presents in acute and chronic forms. While elevated brain ammonia level is known to be a major etiological factor in this disorder, recent studies have shown a significant role of neuroinflammation in the pathogenesis of both acute and chronic HE. This review summarizes the involvement of ammonia in the activation of microglia, as well as the means by which ammonia triggers inflammatory responses in these cells. Additionally, the role of ammonia in stimulating inflammatory events in brain endothelial cells (ECs), likely through the activation of the toll-like receptor-4 and the associated production of cytokines, as well as the stimulation of various inflammatory factors in ECs and in astrocytes, are discussed. This review also summarizes the inflammatory mechanisms by which activation of ECs and microglia impact on astrocytes leading to their dysfunction, ultimately contributing to astrocyte swelling/brain edema in acute HE. The role of microglial activation and its contribution to the progression of neurobehavioral abnormalities in chronic HE are also briefly presented. We posit that a better understanding of the inflammatory events associated with acute and chronic HE will uncover novel therapeutic targets useful in the treatment of patients afflicted with HE.
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Key Words
- AHE, acute hepatic encephalopathy
- ALF, acute liver failure
- BBB, blood–brain barrier
- BDL, bile duct ligation
- COX2, cyclooxygenase-2
- ECs, endothelial cells
- FHF, fulminant hepatic failure
- HE, hepatic encephalopathy
- HO, hemoxygenase
- IL, interleukin
- LPS, lipopolysaccharide
- MAPK, mitogen-activated protein kinases
- NF-κB, nuclear factor-kappaB
- NOX, NADPH oxidase
- ONS, oxidative/nitrative stress
- PLA2, phospholipase-A2
- RONS, reactive oxygen and nitrogen species
- TLR, Toll-like receptor
- TNF-α, tumor necrosis factor-alpha
- Tg, transgenic
- WT, wild type
- ammonia
- cNOS, constitutive nitric oxide synthase
- hepatic encephalopathy
- iNOS, inducible nitric oxide synthase
- neuroinflammation
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Affiliation(s)
| | | | - Michael D. Norenberg
- Laboratory of Neuropathology, Veterans Affairs Medical Center, Miami, FL, USA,Department of Pathology, University of Miami School of Medicine, Miami, FL, USA,Biochemistry & Molecular Biology, University of Miami School of Medicine, Miami, FL, USA,Address for correspondence: Michael D. Norenberg, Department of Pathology (D-33), PO Box 016960, University of Miami School of Medicine, Miami, FL 33101. Tel.: +1 305 575 7000x4018.
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33
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Dhanda S, Sandhir R. Role of dopaminergic and serotonergic neurotransmitters in behavioral alterations observed in rodent model of hepatic encephalopathy. Behav Brain Res 2015; 286:222-35. [PMID: 25639545 DOI: 10.1016/j.bbr.2015.01.042] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 01/17/2015] [Accepted: 01/22/2015] [Indexed: 02/06/2023]
Abstract
The present study was designed to evaluate the role of biogenic amines in behavioral alterations observed in rat model of hepatic encephalopathy (HE) following bile duct ligation (BDL). Male Wistar rats subjected to BDL developed biliary fibrosis after four weeks which was supported by altered liver function tests, increased ammonia levels and histological staining (Sirius red). Animals were assessed for their behavioral performance in terms of cognitive, anxiety and motor functions. The levels of dopamine (DA), serotonin (5-HT), epinephrine and norepinephrine (NE) were estimated in different regions of brain viz. cortex, hippocampus, striatum and cerebellum using HPLC along with activity of monoamine oxidase (MAO). Cognitive assessment of BDL rats revealed a progressive decline in learning, memory formation, retrieval, exploration of novel environment and spontaneous locomotor activity along with decrease in 5-HT and NE levels. This was accompanied by an increase in MAO activity. Motor functions of BDL rats were also altered which were evident from decrease in the time spent on the rotating rod and higher foot faults assessed using narrow beam walk task. A global decrease was observed in the DA content along with an increase in MAO activity. Histopathological studies using hematoxylin-eosin (H&E) and cresyl violet exhibited marked neuronal degeneration, wherein neurons appeared more pyknotic, condensed and damaged. The results reveal that dopaminergic and serotonergic pathways are disturbed in chronic liver failure post-BDL which may be responsible for behavioral impairments observed in HE.
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Affiliation(s)
- Saurabh Dhanda
- Department of Biochemistry, Basic Medical Science Block, Panjab University, Chandigarh 160014, India
| | - Rajat Sandhir
- Department of Biochemistry, Basic Medical Science Block, Panjab University, Chandigarh 160014, India.
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Görg B, Karababa A, Shafigullina A, Bidmon HJ, Häussinger D. Ammonia-induced senescence in cultured rat astrocytes and in human cerebral cortex in hepatic encephalopathy. Glia 2014; 63:37-50. [PMID: 25092802 DOI: 10.1002/glia.22731] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 07/15/2014] [Indexed: 12/13/2022]
Abstract
Hepatic encephalopathy (HE) is a frequent complication of liver cirrhosis and is due to a low-grade cerebral edema associated with oxidative/nitrosative stress. Recent reports suggest that cognitive impairment in cirrhotic patients may not resolve completely after an attack of manifest HE. As astrocyte dysfunction is central to the pathogenesis of HE and astrocytes are critically involved in synaptic plasticity, we tested for sustained impairment of astrocyte function by analyzing expression levels of senescence biomarkers in ammonia-treated cultured rat astrocytes and in postmortem brain samples from cirrhotic patients with or without HE. NH4 Cl time- and dose-dependently inhibited proliferation of cultured astrocytes by up to 45% (5 mmol/L, 72 h) and strongly increased senescence-associated β-galactosidase activity. Inhibition of astrocyte proliferation by ammonia was mediated by a l-methionine sulfoximine-, oxidative stress-, and p38(MAPK) -dependent activation of p53 associated with enhanced transcription of cell cycle inhibitory genes GADD45α and p21. Mitochondria and the nucleus were identified as sources of oxygen radical formation after prolonged NH4 Cl exposure. Concurrently, NH4 Cl (5 mmol/L) treatment inhibited both epidermal growth factor- and brain-derived neurotrophic factor (BDNF)-induced proliferation as well as BDNF-mediated astrocyte morphology changes through downregulation of the respective growth factor receptors epidermal growth factor receptor and truncated tyrosine receptor kinase B. Increased mRNA expression levels of senescence-associated genes were also found in post mortem brain samples from patients with liver cirrhosis with HE, but not in those without HE. The data suggest that ammonia toxicity and HE are associated with premature astrocyte senescence, which may impair neurotransmission and contribute to persistence of cognitive disturbances after resolution of episodes of overt HE.
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Affiliation(s)
- Boris Görg
- Clinic for Gastroenterologogy, Hepatology and Infectious Diseases, Heinrich Heine University, Düsseldorf, Germany
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