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Nie X, Zhang T, Huang X, Gu C, Zuo W, Fu LJ, Dong Y, Liu H. Novel therapeutic targets: bifidobacterium-mediated urea cycle regulation in colorectal cancer. Cell Biol Toxicol 2024; 40:64. [PMID: 39096436 PMCID: PMC11297826 DOI: 10.1007/s10565-024-09889-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2024] [Accepted: 06/03/2024] [Indexed: 08/05/2024]
Abstract
BACKGROUND AND PURPOSE Colorectal cancer (CRC) is a widespread malignancy with a complex and not entirely elucidated pathogenesis. This study aims to explore the role of Bifidobacterium in the urea cycle (UC) and its influence on the progression of CRC, a topic not extensively studied previously. EXPERIMENTAL APPROACH Utilizing both bioinformatics and experimental methodologies, this research involved analyzing bacterial abundance in CRC patients in comparison to healthy individuals. The study particularly focused on the abundance of BA. Additionally, transcriptomic data analysis and cellular experiments were conducted to investigate the impact of Bifidobacterium on ammonia metabolism and mitochondrial function, specifically examining its regulation of the key UC gene, ALB. KEY RESULTS The analysis revealed a significant decrease in Bifidobacterium abundance in CRC patients. Furthermore, Bifidobacterium was found to suppress ammonia metabolism and induce mitochondrial dysfunction through the regulation of the ALB gene, which is essential in the context of UC. These impacts contributed to the suppression of CRC cell proliferation, a finding corroborated by animal experimental results. CONCLUSIONS AND IMPLICATIONS This study elucidates the molecular mechanism by which Bifidobacterium impacts CRC progression, highlighting its role in regulating key metabolic pathways. These findings provide potential targets for novel therapeutic strategies in CRC treatment, emphasizing the importance of microbiota in cancer progression.
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Affiliation(s)
- Xusheng Nie
- Department of Gastroenterology, Yunyang County People's Hospital, Chongqing, 404599, China
| | - Tingting Zhang
- Department of Pediatrics, Rongchang District People's Hospital, Chongqing, 402460, China
| | - Xiumei Huang
- Department of Digestion, Rongchang District People's Hospital of Chongqing, No.3, North Guangchang Road, Changyuan Street, Rongchang District, Chongqing, 402460, China
| | - Chongqi Gu
- Department of Digestion, Rongchang District People's Hospital of Chongqing, No.3, North Guangchang Road, Changyuan Street, Rongchang District, Chongqing, 402460, China
| | - Wei Zuo
- Department of Herbal Medicine, School of Traditional Chinese Medicine, Chongqing Medical University, Chongqing, 400016, China
- Department of Pharmacology, Academician Workstation, Changsha Medical University, Changsha, 410219, China
| | - Li-Juan Fu
- Department of Herbal Medicine, School of Traditional Chinese Medicine, Chongqing Medical University, Chongqing, 400016, China
- Department of Pharmacology, Academician Workstation, Changsha Medical University, Changsha, 410219, China
| | - Yiping Dong
- Department of Digital Medicine, Department of Bioengineering and Imaging, Army Medical University, Chongqing, 400038, China
| | - Hao Liu
- Department of Digestion, Rongchang District People's Hospital of Chongqing, No.3, North Guangchang Road, Changyuan Street, Rongchang District, Chongqing, 402460, China.
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de Wit K, van Doorn DJ, Mol B, van Vught LA, Nevens F, Beuers U, Ponsioen CY, Teunissen CE, Takkenberg RB. Neurofilament light chain but not glial fibrillary acidic protein is a potential biomarker of overt hepatic encephalopathy in patients with cirrhosis. Ann Hepatol 2024; 29:101496. [PMID: 38460714 DOI: 10.1016/j.aohep.2024.101496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 12/04/2023] [Accepted: 01/04/2024] [Indexed: 03/11/2024]
Abstract
INTRODUCTION AND OBJECTIVES Hepatic encephalopathy (HE) is a frequent complication of cirrhosis and may cause cerebral damage. Neurodegenerative diseases can induce the release of neuroproteins like neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) in body fluids, including blood plasma. We investigated whether NfL and GFAP could serve as potential diagnostic plasma biomarkers for overt HE (oHE). MATERIALS AND METHODS We included 85 patients from three prospective cohorts with different stages of liver disease and HE severity. The following patients were included: 1) 34 patients with primary sclerosing cholangitis (PSC) with compensated disease; 2) 17 patients with advanced liver disease without oHE before elective transjugular intrahepatic portosystemic shunt (TIPS) placement; 3) 17 intensive care unit (ICU) patients with oHE and 17 ICU patients without cirrhosis or oHE. Plasma NfL and GFAP were measured using single molecule assays. RESULTS ICU oHE patients had higher NfL concentrations compared to pre-TIPS patients or ICU controls (p < 0.05, each). Median GFAP concentrations were equal in the ICU oHE and pre-TIPS patients or ICU controls. Plasma NfL and GFAP concentrations correlated with Model for End-Stage Liver Disease (MELD) scores (R = 0.58 and R = 0.40, p < 0.001, each). CONCLUSIONS Plasma NfL deserves further evaluation as potential diagnostic biomarker for oHE and correlates with the MELD score.
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Affiliation(s)
- Koos de Wit
- Department of Gastroenterology and Hepatology, Amsterdam UMC, University of Amsterdam, Amsterdam Gastroenterology Endocrinology and Metabolism, Amsterdam, The Netherlands
| | - Diederick J van Doorn
- Department of Gastroenterology and Hepatology, Amsterdam UMC, University of Amsterdam, Amsterdam Gastroenterology Endocrinology and Metabolism, Amsterdam, The Netherlands
| | - Bregje Mol
- Department of Gastroenterology and Hepatology, Amsterdam UMC, University of Amsterdam, Amsterdam Gastroenterology Endocrinology and Metabolism, Amsterdam, The Netherlands
| | - Lonneke A van Vught
- Department of Intensive Care, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands; Center of Experimental and Molecular Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Frederik Nevens
- Department of Gastroenterology and Hepatology, University Hospitals KU Leuven, Leuven, Belgium
| | - Ulrich Beuers
- Department of Gastroenterology and Hepatology, Amsterdam UMC, University of Amsterdam, Amsterdam Gastroenterology Endocrinology and Metabolism, Amsterdam, The Netherlands
| | - Cyriel Y Ponsioen
- Department of Gastroenterology and Hepatology, Amsterdam UMC, University of Amsterdam, Amsterdam Gastroenterology Endocrinology and Metabolism, Amsterdam, The Netherlands
| | - Charlotte E Teunissen
- Neurochemistry Laboratory, Department of Clinical Chemistry, Amsterdam Neuroscience, Neurodegeneration, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - R Bart Takkenberg
- Department of Gastroenterology and Hepatology, Amsterdam UMC, University of Amsterdam, Amsterdam Gastroenterology Endocrinology and Metabolism, Amsterdam, The Netherlands.
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3
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Pierzchala K, Hadjihambi A, Mosso J, Jalan R, Rose CF, Cudalbu C. Lessons on brain edema in HE: from cellular to animal models and clinical studies. Metab Brain Dis 2024; 39:403-437. [PMID: 37606786 PMCID: PMC10957693 DOI: 10.1007/s11011-023-01269-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 07/24/2023] [Indexed: 08/23/2023]
Abstract
Brain edema is considered as a common feature associated with hepatic encephalopathy (HE). However, its central role as cause or consequence of HE and its implication in the development of the neurological alterations linked to HE are still under debate. It is now well accepted that type A and type C HE are biologically and clinically different, leading to different manifestations of brain edema. As a result, the findings on brain edema/swelling in type C HE are variable and sometimes controversial. In the light of the changing natural history of liver disease, better description of the clinical trajectory of cirrhosis and understanding of molecular mechanisms of HE, and the role of brain edema as a central component in the pathogenesis of HE is revisited in the current review. Furthermore, this review highlights the main techniques to measure brain edema and their advantages/disadvantages together with an in-depth description of the main ex-vivo/in-vivo findings using cell cultures, animal models and humans with HE. These findings are instrumental in elucidating the role of brain edema in HE and also in designing new multimodal studies by performing in-vivo combined with ex-vivo experiments for a better characterization of brain edema longitudinally and of its role in HE, especially in type C HE where water content changes are small.
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Affiliation(s)
- Katarzyna Pierzchala
- CIBM Center for Biomedical Imaging, Lausanne, Switzerland.
- Animal Imaging and Technology, EPFL, Lausanne, Switzerland.
| | - Anna Hadjihambi
- The Roger Williams Institute of Hepatology London, Foundation for Liver Research, London, SE5 9NT, UK
- Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Jessie Mosso
- CIBM Center for Biomedical Imaging, Lausanne, Switzerland
- Animal Imaging and Technology, EPFL, Lausanne, Switzerland
- Laboratory for Functional and Metabolic Imaging (LIFMET), EPFL, Lausanne, Switzerland
| | - Rajiv Jalan
- Liver Failure Group, Institute for Liver and Digestive Health, University College London, Royal Free Campus, London, UK
- European Foundation for the Study of Chronic Liver Failure (EF Clif), Barcelona, Spain
| | - Christopher F Rose
- Hépato-Neuro Laboratory, Centre de Recherche du Centre Hospitalier de l', Université de Montréal (CRCHUM), Montreal, QC, H2X 0A9, Canada
- Department of Medicine, Faculty of Medicine, Université de Montréal, QC, Montreal, H3T 1J4, Canada
| | - Cristina Cudalbu
- CIBM Center for Biomedical Imaging, Lausanne, Switzerland.
- Animal Imaging and Technology, EPFL, Lausanne, Switzerland.
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4
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Kang YJ, Diep YN, Tran M, Tran VTA, Ambrin G, Ngo H, Cho H. Three-dimensional human neural culture on a chip recapitulating neuroinflammation and neurodegeneration. Nat Protoc 2023; 18:2838-2867. [PMID: 37542184 DOI: 10.1038/s41596-023-00861-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 05/30/2023] [Indexed: 08/06/2023]
Abstract
Neuroinflammation has either beneficial or detrimental effects, depending on risk factors and neuron-glia interactions in neurological disorders. However, studying neuroinflammation has been challenging due to the complexity of cell-cell interactions and lack of physio-pathologically relevant neuroinflammatory models. Here, we describe our three-dimensional microfluidic multicellular human neural culture model, referred to as a 'brain-on-a-chip' (BoC). This elucidates neuron-glia interactions in a controlled manner and recapitulates pathological signatures of the major neurological disorders: dementia, brain tumor and brain edema. This platform includes a chemotaxis module offering a week-long, stable chemo-gradient compared with the few hours in other chemotaxis models. Additionally, compared with conventional brain models cultured with mixed phenotypes of microglia, our BoC can separate the disease-associated microglia out of heterogeneous population and allow selective neuro-glial engagement in three dimensions. This provides benefits of interpreting the neuro-glia interactions while revealing that the prominent activation of innate immune cells is the risk factor leading to synaptic impairment and neuronal loss, validated in our BoC models of disorders. This protocol describes how to fabricate and implement our human BoC, manipulate in real time and perform end-point analyses. It takes 2 d to set up the device and cell preparations, 1-9 weeks to develop brain models under disease conditions and 2-3 d to carry out analyses. This protocol requires at least 1 month training for researchers with basic molecular biology techniques. Taken together, our human BoCs serve as reliable and valuable platforms to investigate pathological mechanisms involving neuroinflammation and to assess therapeutic strategies modulating neuroinflammation in neurological disorders.
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Affiliation(s)
- You Jung Kang
- Institute of Quantum Biophysics, Sungkyunkwan University, Suwon, Republic of Korea
- Department of Biophysics, Sungkyunkwan University, Suwon, Republic of Korea
| | - Yen N Diep
- Institute of Quantum Biophysics, Sungkyunkwan University, Suwon, Republic of Korea
- Department of Biophysics, Sungkyunkwan University, Suwon, Republic of Korea
- Department of Intelligent Precision Healthcare Convergence, Sungkyunkwan University, Suwon, Republic of Korea
| | - Minh Tran
- Institute of Quantum Biophysics, Sungkyunkwan University, Suwon, Republic of Korea
- Department of Biophysics, Sungkyunkwan University, Suwon, Republic of Korea
- Department of Intelligent Precision Healthcare Convergence, Sungkyunkwan University, Suwon, Republic of Korea
| | - Van Thi Ai Tran
- Institute of Quantum Biophysics, Sungkyunkwan University, Suwon, Republic of Korea
- Department of Biophysics, Sungkyunkwan University, Suwon, Republic of Korea
| | - Ghuncha Ambrin
- Department of Psychiatry, School of Medicine, University of California San Diego, San Diego, CA, USA
| | - Huyen Ngo
- Institute of Quantum Biophysics, Sungkyunkwan University, Suwon, Republic of Korea
- Department of Biophysics, Sungkyunkwan University, Suwon, Republic of Korea
- Department of Intelligent Precision Healthcare Convergence, Sungkyunkwan University, Suwon, Republic of Korea
| | - Hansang Cho
- Institute of Quantum Biophysics, Sungkyunkwan University, Suwon, Republic of Korea.
- Department of Biophysics, Sungkyunkwan University, Suwon, Republic of Korea.
- Department of Intelligent Precision Healthcare Convergence, Sungkyunkwan University, Suwon, Republic of Korea.
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5
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Dunn E, Steinert JR, Stone A, Sahota V, Williams RSB, Snowden S, Augustin H. Medium-Chain Fatty Acids Rescue Motor Function and Neuromuscular Junction Degeneration in a Drosophila Model of Amyotrophic Lateral Sclerosis. Cells 2023; 12:2163. [PMID: 37681895 PMCID: PMC10486503 DOI: 10.3390/cells12172163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 08/21/2023] [Accepted: 08/22/2023] [Indexed: 09/09/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is an adult-onset neurodegenerative disease characterised by progressive degeneration of the motor neurones. An expanded GGGGCC (G4C2) hexanucleotide repeat in C9orf72 is the most common genetic cause of ALS and frontotemporal dementia (FTD); therefore, the resulting disease is known as C9ALS/FTD. Here, we employ a Drosophila melanogaster model of C9ALS/FTD (C9 model) to investigate a role for specific medium-chain fatty acids (MCFAs) in reversing pathogenic outcomes. Drosophila larvae overexpressing the ALS-associated dipeptide repeats (DPRs) in the nervous system exhibit reduced motor function and neuromuscular junction (NMJ) defects. We show that two MCFAs, nonanoic acid (NA) and 4-methyloctanoic acid (4-MOA), can ameliorate impaired motor function in C9 larvae and improve NMJ degeneration, although their mechanisms of action are not identical. NA modified postsynaptic glutamate receptor density, whereas 4-MOA restored defects in the presynaptic vesicular release. We also demonstrate the effects of NA and 4-MOA on metabolism in C9 larvae and implicate various metabolic pathways as dysregulated in our ALS model. Our findings pave the way to identifying novel therapeutic targets and potential treatments for ALS.
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Affiliation(s)
- Ella Dunn
- Centre for Biomedical Sciences, Department of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 OEX, UK; (E.D.); (R.S.B.W.)
| | - Joern R. Steinert
- Faculty of Medicine & Health Sciences, Queen’s Medical Centre, Nottingham NG7 2UH, UK; (J.R.S.); (A.S.)
| | - Aelfwin Stone
- Faculty of Medicine & Health Sciences, Queen’s Medical Centre, Nottingham NG7 2UH, UK; (J.R.S.); (A.S.)
| | - Virender Sahota
- Centre for Biomedical Sciences, Department of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 OEX, UK; (E.D.); (R.S.B.W.)
| | - Robin S. B. Williams
- Centre for Biomedical Sciences, Department of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 OEX, UK; (E.D.); (R.S.B.W.)
| | - Stuart Snowden
- Centre for Biomedical Sciences, Department of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 OEX, UK; (E.D.); (R.S.B.W.)
| | - Hrvoje Augustin
- Centre for Biomedical Sciences, Department of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 OEX, UK; (E.D.); (R.S.B.W.)
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6
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Claeys W, Van Hoecke L, Lernout H, De Nolf C, Van Imschoot G, Van Wonterghem E, Verhaege D, Castelein J, Geerts A, Van Steenkiste C, Vandenbroucke RE. Experimental hepatic encephalopathy causes early but sustained glial transcriptional changes. J Neuroinflammation 2023; 20:130. [PMID: 37248507 DOI: 10.1186/s12974-023-02814-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2023] [Accepted: 05/21/2023] [Indexed: 05/31/2023] Open
Abstract
Hepatic encephalopathy (HE) is a common complication of liver cirrhosis, associated with high morbidity and mortality, for which no brain-targeted therapies exist at present. The interplay between hyperammonemia and inflammation is thought to drive HE development. As such, astrocytes, the most important ammonia-metabolizing cells in the brain, and microglia, the main immunomodulatory cells in the brain, have been heavily implicated in HE development. As insight into cellular perturbations driving brain pathology remains largely elusive, we aimed to investigate cell-type specific transcriptomic changes in the HE brain. In the recently established mouse bile duct ligation (BDL) model of HE, we performed RNA-Seq of sorted astrocytes and microglia at 14 and 28 days after induction. This revealed a marked transcriptional response in both cell types which was most pronounced in microglia. In both cell types, pathways related to inflammation and hypoxia, mechanisms commonly implicated in HE, were enriched. Additionally, astrocytes exhibited increased corticoid receptor and oxidative stress signaling, whereas microglial transcriptome changes were linked to immune cell attraction. Accordingly, both monocytes and neutrophils accumulated in the BDL mouse brain. Time-dependent changes were limited in both cell types, suggesting early establishment of a pathological phenotype. While HE is often considered a unique form of encephalopathy, astrocytic and microglial transcriptomes showed significant overlap with previously established gene expression signatures in other neuroinflammatory diseases like septic encephalopathy and stroke, suggesting common pathophysiological mechanisms. Our dataset identifies key molecular mechanisms involved in preclinical HE and provides a valuable resource for development of novel glial-directed therapeutic strategies.
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Affiliation(s)
- Wouter Claeys
- Hepatology Research Unit, Department of Internal Medicine and Paediatrics, Ghent University, 9000, Ghent, Belgium
- Liver Research Center Ghent, Ghent University Hospital, Ghent University, 9000, Ghent, Belgium
- Barriers in Inflammation, VIB Center for Inflammation Research, VIB, Technologiepark-Zwijnaarde 71, 9052, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, 9000, Ghent, Belgium
| | - Lien Van Hoecke
- Barriers in Inflammation, VIB Center for Inflammation Research, VIB, Technologiepark-Zwijnaarde 71, 9052, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, 9000, Ghent, Belgium
| | - Hannah Lernout
- Barriers in Inflammation, VIB Center for Inflammation Research, VIB, Technologiepark-Zwijnaarde 71, 9052, Ghent, Belgium
- IBD Research Unit, Department of Internal Medicine and Paediatrics, Ghent University, 9000, Ghent, Belgium
| | - Clint De Nolf
- Barriers in Inflammation, VIB Center for Inflammation Research, VIB, Technologiepark-Zwijnaarde 71, 9052, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, 9000, Ghent, Belgium
- Department of Internal Medicine and Paediatrics, Ghent University, 9000, Ghent, Belgium
| | - Griet Van Imschoot
- Barriers in Inflammation, VIB Center for Inflammation Research, VIB, Technologiepark-Zwijnaarde 71, 9052, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, 9000, Ghent, Belgium
| | - Elien Van Wonterghem
- Barriers in Inflammation, VIB Center for Inflammation Research, VIB, Technologiepark-Zwijnaarde 71, 9052, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, 9000, Ghent, Belgium
| | - Daan Verhaege
- Barriers in Inflammation, VIB Center for Inflammation Research, VIB, Technologiepark-Zwijnaarde 71, 9052, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, 9000, Ghent, Belgium
| | - Jonas Castelein
- Barriers in Inflammation, VIB Center for Inflammation Research, VIB, Technologiepark-Zwijnaarde 71, 9052, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, 9000, Ghent, Belgium
| | - Anja Geerts
- Hepatology Research Unit, Department of Internal Medicine and Paediatrics, Ghent University, 9000, Ghent, Belgium
- Liver Research Center Ghent, Ghent University Hospital, Ghent University, 9000, Ghent, Belgium
- Department of Gastroenterology and Hepatology, Ghent University Hospital, Ghent, Belgium
| | - Christophe Van Steenkiste
- Department of Gastroenterology and Hepatology, Antwerp University, Antwerp, Belgium
- Department of Gastroenterology and Hepatology, Maria Middelares Hospital, Ghent, Belgium
| | - Roosmarijn E Vandenbroucke
- Barriers in Inflammation, VIB Center for Inflammation Research, VIB, Technologiepark-Zwijnaarde 71, 9052, Ghent, Belgium.
- Department of Biomedical Molecular Biology, Ghent University, 9000, Ghent, Belgium.
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7
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HPRT1 Deficiency Induces Alteration of Mitochondrial Energy Metabolism in the Brain. Mol Neurobiol 2023; 60:3147-3157. [PMID: 36802322 PMCID: PMC10122629 DOI: 10.1007/s12035-023-03266-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 02/12/2023] [Indexed: 02/23/2023]
Abstract
Alterations in function of hypoxanthine guanine phosphoribosyl transferase (HPRT), one of the major enzymes involved in purine nucleotide exchange, lead to overproduction of uric acid and produce various symptoms of Lesch-Nyhan syndrome (LNS). One of the hallmarks of LNS is maximal expression of HPRT in the central nervous system with the highest activity of this enzyme in the midbrain and basal ganglia. However, the nature of neurological symptoms has yet to be clarified in details. Here, we studied whether HPRT1 deficiency changes mitochondrial energy metabolism and redox balance in murine neurons from the cortex and midbrain. We found that HPRT1 deficiency inhibits complex I-dependent mitochondrial respiration resulting in increased levels of mitochondrial NADH, reduction of the mitochondrial membrane potential, and increased rate of reactive oxygen species (ROS) production in mitochondria and cytosol. However, increased ROS production did not induce oxidative stress and did not decrease the level of endogenous antioxidant glutathione (GSH). Thus, disruption of mitochondrial energy metabolism but not oxidative stress could play a role of potential trigger of brain pathology in LNS.
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8
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Morrison MA, Artru F, Trovato FM, Triantafyllou E, McPhail MJ. Potential therapies for acute-on-chronic liver failure. Liver Int 2023. [PMID: 36800487 DOI: 10.1111/liv.15545] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 01/16/2023] [Accepted: 02/15/2023] [Indexed: 02/19/2023]
Abstract
Acute-on-chronic liver failure (ACLF) is a syndrome that develops in approximately 30% of patients hospitalised with cirrhosis and is characterised by an acute decompensation of liver function associated with extra-hepatic organ failures and a high short-term mortality. At present, no specific therapies are available for ACLF, and current management is limited to treatment of the precipitating event and organ support. Given the high prevalence and high mortality of this severe liver disease, there is an urgent need for targeted treatments. There is increasing evidence of the important role played by systemic inflammation and immune dysfunction in the pathophysiology of ACLF and a better understanding of these immune processes is resulting in new therapeutic targets. The aim of this review is to present an overview of ongoing studies of potentially promising therapies and how they could be utilised in the management of ACLF.
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Affiliation(s)
- Maura A Morrison
- Institute of Liver Studies, King's College Hospital, London, UK
- Department of Inflammation Biology, School of Immunology and Microbial Sciences, King's College London, London, UK
| | - Florent Artru
- Institute of Liver Studies, King's College Hospital, London, UK
- Department of Inflammation Biology, School of Immunology and Microbial Sciences, King's College London, London, UK
| | - Francesca M Trovato
- Institute of Liver Studies, King's College Hospital, London, UK
- Department of Inflammation Biology, School of Immunology and Microbial Sciences, King's College London, London, UK
| | - Evangelos Triantafyllou
- Section of Hepatology and Gastroenterology, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Mark J McPhail
- Institute of Liver Studies, King's College Hospital, London, UK
- Department of Inflammation Biology, School of Immunology and Microbial Sciences, King's College London, London, UK
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9
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Mikkelsen ACD, Thomsen KL, Mookerjee RP, Hadjihambi A. The role of brain inflammation and abnormal brain oxygen homeostasis in the development of hepatic encephalopathy. Metab Brain Dis 2022; 38:1707-1716. [PMID: 36326976 DOI: 10.1007/s11011-022-01105-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 10/10/2022] [Indexed: 11/06/2022]
Abstract
Hepatic encephalopathy (HE) is a frequent complication of chronic liver disease (CLD) and has a complex pathogenesis. Several preclinical and clinical studies have reported the presence of both peripheral and brain inflammation in CLD and their potential impact in the development of HE. Altered brain vascular density and tone, as well as compromised cerebral and systemic blood flow contributing to the development of brain hypoxia, have also been reported in animal models of HE, while a decrease in cerebral metabolic rate of oxygen and cerebral blood flow has consistently been observed in patients with HE. Whilst significant strides in our understanding have been made over the years, evaluating all these mechanistic elements in vivo and showing causal association with development of HE, have been limited through the practical constraints of experimentation. Nonetheless, improvements in non-invasive assessments of different neurophysiological parameters, coupled with techniques to assess changes in inflammatory and metabolic pathways, will help provide more granular insights on these mechanisms. In this special issue we discuss some of the emerging evidence supporting the hypothesis that brain inflammation and abnormal oxygen homeostasis occur interdependently during CLD and comprise important contributors to the development of HE. This review aims at furnishing evidence for further research in brain inflammation and oxygen homeostasis as additional therapeutic targets and potentially diagnostic markers for HE.
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Affiliation(s)
| | - Karen Louise Thomsen
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
- UCL Institute of Liver and Digestive Health, University College London, London, UK
| | - Rajeshwar Prosad Mookerjee
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
- UCL Institute of Liver and Digestive Health, University College London, London, UK
| | - Anna Hadjihambi
- The Roger Williams Institute of Hepatology London, Foundation for Liver Research, London, SE5 9NT, UK.
- Faculty of Life Sciences and Medicine, King's College London, London, UK.
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