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Trivedi PJ, Hirschfield GM, Adams DH, Vierling JM. Immunopathogenesis of Primary Biliary Cholangitis, Primary Sclerosing Cholangitis and Autoimmune Hepatitis: Themes and Concepts. Gastroenterology 2024; 166:995-1019. [PMID: 38342195 DOI: 10.1053/j.gastro.2024.01.049] [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: 04/25/2023] [Revised: 01/21/2024] [Accepted: 01/28/2024] [Indexed: 02/13/2024]
Abstract
Autoimmune liver diseases include primary biliary cholangitis, primary sclerosing cholangitis, and autoimmune hepatitis, a family of chronic immune-mediated disorders that target hepatocytes and cholangiocytes. Treatments remain nonspecific, variably effective, and noncurative, and the need for liver transplantation is disproportionate to their rarity. Development of effective therapies requires better knowledge of pathogenic mechanisms, including the roles of genetic risk, and how the environment and gut dysbiosis cause immune cell dysfunction and aberrant bile acid signaling. This review summarizes key etiologic and pathogenic concepts and themes relevant for clinical practice and how such learning can guide the development of new therapies for people living with autoimmune liver diseases.
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Affiliation(s)
- Palak J Trivedi
- National Institute for Health Research Birmingham Biomedical Research Centre, Centre for Liver and Gastrointestinal Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom; Liver Unit, University Hospitals Birmingham, Birmingham, United Kingdom; Institute of Translational Medicine, University of Birmingham, Birmingham, United Kingdom.
| | - Gideon M Hirschfield
- Division of Gastroenterology and Hepatology, Toronto Centre for Liver Disease, University of Toronto, Toronto, Ontario, Canada
| | - David H Adams
- National Institute for Health Research Birmingham Biomedical Research Centre, Centre for Liver and Gastrointestinal Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom; Liver Unit, University Hospitals Birmingham, Birmingham, United Kingdom
| | - John M Vierling
- Section of Gastroenterology and Hepatology, Department of Medicine, Baylor College of Medicine, Houston, Texas; Division of Abdominal Transplantation, Department of Surgery, Baylor College of Medicine, Houston, Texas.
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Tao T, Tang A, Lv L, Yuan J, Wu L, Zhao L, Chen J. Investigating the causal relationship and potential shared diagnostic genes between primary biliary cholangitis and systemic lupus erythematosus using bidirectional Mendelian randomization and transcriptomic analyses. Front Immunol 2024; 15:1270401. [PMID: 38464525 PMCID: PMC10921416 DOI: 10.3389/fimmu.2024.1270401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 02/05/2024] [Indexed: 03/12/2024] Open
Abstract
Background The co-occurrence of primary biliary cholangitis (PBC) and systemic lupus erythematosus (SLE) has been consistently reported in observational studies. Nevertheless, the underlying causal correlation between these two conditions still needs to be established. Methods We performed a bidirectional two-sample Mendelian randomization (MR) study to assess their causal association. Five MR analysis methods were utilized for causal inference, with inverse-variance weighted (IVW) selected as the primary method. The Mendelian Randomization Pleiotropy RESidual Sum and Outlier (MR-PRESSO) and the IVW Radial method were applied to exclude outlying SNPs. To assess the robustness of the MR results, five sensitivity analyses were carried out. Multivariable MR (MVMR) analysis was also employed to evaluate the effect of possible confounders. In addition, we integrated transcriptomic data from PBC and SLE, employing Weighted Gene Co-expression Network Analysis (WGCNA) to explore shared genes between the two diseases. Then, we used Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment methods to perform on the shared genes. The Least Absolute Shrinkage and Selection Operator (LASSO) regression algorithm was utilized to identify potential shared diagnostic genes. Finally, we verified the potential shared diagnostic genes in peripheral blood mononuclear cells (PBMCs)-specific cell populations of SLE patients by single-cell analysis. Results Our MR study provided evidence that PBC had a causal relationship with SLE (IVW, OR: 1.347, 95% CI: 1.276 - 1.422, P < 0.001) after removing outliers (MR-PRESSO, rs35464393, rs3771317; IVW Radial, rs11065987, rs12924729, rs3745516). Conversely, SLE also had a causal association with PBC (IVW, OR: 1.225, 95% CI: 1.141 - 1.315, P < 0.001) after outlier correction (MR-PRESSO, rs11065987, rs3763295, rs7774434; IVW Radial, rs2297067). Sensitivity analyses confirmed the robustness of the MR findings. MVMR analysis indicated that body mass index (BMI), smoking and drinking were not confounding factors. Moreover, bioinformatic analysis identified PARP9, ABCA1, CEACAM1, and DDX60L as promising diagnostic biomarkers for PBC and SLE. These four genes are highly expressed in CD14+ monocytes in PBMCs of SLE patients and potentially associated with innate immune responses and immune activation. Conclusion Our study confirmed the bidirectional causal relationship between PBC and SLE and identified PARP9, ABCA1, CEACAM1, and DDX60L genes as the most potentially shared diagnostic genes between the two diseases, providing insights for the exploration of the underlying mechanisms of these disorders.
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Affiliation(s)
- Tian Tao
- Department of Nephrology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Anqi Tang
- Department of Nephrology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Lizeyu Lv
- Department of Nephrology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Jianhua Yuan
- Department of Cardiovascular Medicine, Chengdu Second People’s Hospital, Chengdu, Chengdu, China
| | - Ling Wu
- Department of Nephrology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Liangbin Zhao
- Department of Nephrology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Jun Chen
- Department of Intensive Care Medicine, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
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Lerner A, Benzvi C, Vojdani A. SARS-CoV-2 Gut-Targeted Epitopes: Sequence Similarity and Cross-Reactivity Join Together for Molecular Mimicry. Biomedicines 2023; 11:1937. [PMID: 37509576 PMCID: PMC10376948 DOI: 10.3390/biomedicines11071937] [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: 06/14/2023] [Revised: 07/02/2023] [Accepted: 07/06/2023] [Indexed: 07/30/2023] Open
Abstract
The gastrointestinal tract can be heavily infected by SARS-CoV-2. Being an auto-immunogenic virus, SARS-CoV-2 represents an environmental factor that might play a role in gut-associated autoimmune diseases. However, molecular mimicry between the virus and the intestinal epitopes is under-investigated. The present study aims to elucidate sequence similarity between viral antigens and human enteric sequences, based on known cross-reactivity. SARS-CoV-2 epitopes that cross-react with human gut antigens were explored, and sequence alignment was performed against self-antigens implicated in enteric autoimmune conditions. Experimental SARS-CoV-2 epitopes were aggregated from the Immune Epitope Database (IEDB), while enteric antigens were obtained from the UniProt Knowledgebase. A Pairwise Local Alignment tool, EMBOSS Matcher, was employed for the similarity search. Sequence similarity and targeted cross-reactivity were depicted between 10 pairs of immunoreactive epitopes. Similar pairs were found in four viral proteins and seven enteric antigens related to ulcerative colitis, primary biliary cholangitis, celiac disease, and autoimmune hepatitis. Antibodies made against the viral proteins that were cross-reactive with human gut antigens are involved in several essential cellular functions. The relationship and contribution of those intestinal cross-reactive epitopes to SARS-CoV-2 or its potential contribution to gut auto-immuno-genesis are discussed.
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Affiliation(s)
- Aaron Lerner
- Chaim Sheba Medical Center, The Zabludowicz Research Center for Autoimmune Diseases, Ramat Gan 52621, Israel
- Research Department, Ariel University, Ariel 40700, Israel
| | - Carina Benzvi
- Chaim Sheba Medical Center, The Zabludowicz Research Center for Autoimmune Diseases, Ramat Gan 52621, Israel
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Yang Y, He X, Rojas M, Leung PSC, Gao L. Mechanism-based target therapy in primary biliary cholangitis: opportunities before liver cirrhosis? Front Immunol 2023; 14:1184252. [PMID: 37325634 PMCID: PMC10266968 DOI: 10.3389/fimmu.2023.1184252] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Accepted: 05/16/2023] [Indexed: 06/17/2023] Open
Abstract
Primary biliary cholangitis (PBC) is an immune-mediated liver disease characterized by cholestasis, biliary injuries, liver fibrosis, and chronic non-suppurative cholangitis. The pathogenesis of PBC is multifactorial and involves immune dysregulation, abnormal bile metabolism, and progressive fibrosis, ultimately leading to cirrhosis and liver failure. Ursodeoxycholic acid (UDCA) and obeticholic acid (OCA) are currently used as first- and second-line treatments, respectively. However, many patients do not respond adequately to UDCA, and the long-term effects of these drugs are limited. Recent research has advanced our understanding the mechanisms of pathogenesis in PBC and greatly facilitated development of novel drugs to target mechanistic checkpoints. Animal studies and clinical trials of pipeline drugs have yielded promising results in slowing disease progression. Targeting immune mediated pathogenesis and anti-inflammatory therapies are focused on the early stage, while anti-cholestatic and anti-fibrotic therapies are emphasized in the late stage of disease, which is characterized by fibrosis and cirrhosis development. Nonetheless, it is worth noting that currently, there exists a dearth of therapeutic options that can effectively impede the progression of the disease to its terminal stages. Hence, there is an urgent need for further research aimed at investigating the underlying pathophysiology mechanisms with potential therapeutic effects. This review highlights our current knowledge of the underlying immunological and cellular mechanisms of pathogenesis in PBC. Further, we also address current mechanism-based target therapies for PBC and potential therapeutic strategies to improve the efficacy of existing treatments.
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Affiliation(s)
- Yushu Yang
- Department of Rheumatology and Immunology, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, China
| | - XiaoSong He
- Division of Rheumatology, Allergy, and Clinical Immunology, University of California, Davis, Davis, CA, United States
| | - Manuel Rojas
- Division of Rheumatology, Allergy, and Clinical Immunology, University of California, Davis, Davis, CA, United States
- Center for Autoimmune Diseases Research (CREA), School of Medicine and Health Sciences, Universidad del Rosario, Bogota, Colombia
| | - Patrick S. C. Leung
- Division of Rheumatology, Allergy, and Clinical Immunology, University of California, Davis, Davis, CA, United States
| | - Lixia Gao
- Department of Rheumatology and Immunology, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, China
- Division of Rheumatology, Allergy, and Clinical Immunology, University of California, Davis, Davis, CA, United States
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Paillet J, Plantureux C, Lévesque S, Le Naour J, Stoll G, Sauvat A, Caudana P, Tosello Boari J, Bloy N, Lachkar S, Martins I, Opolon P, Checcoli A, Delaune A, Robil N, de la Grange P, Hamroune J, Letourneur F, Autret G, Leung PS, Gershwin ME, Zhu JS, Kurth MJ, Lekbaby B, Augustin J, Kim Y, Gujar S, Coulouarn C, Fouassier L, Zitvogel L, Piaggio E, Housset C, Soussan P, Maiuri MC, Kroemer G, Pol JG. Autoimmunity affecting the biliary tract fuels the immunosurveillance of cholangiocarcinoma. J Exp Med 2021; 218:e20200853. [PMID: 34495298 PMCID: PMC8429038 DOI: 10.1084/jem.20200853] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 06/17/2021] [Accepted: 08/09/2021] [Indexed: 12/12/2022] Open
Abstract
Cholangiocarcinoma (CCA) results from the malignant transformation of cholangiocytes. Primary sclerosing cholangitis (PSC) and primary biliary cholangitis (PBC) are chronic diseases in which cholangiocytes are primarily damaged. Although PSC is an inflammatory condition predisposing to CCA, CCA is almost never found in the autoimmune context of PBC. Here, we hypothesized that PBC might favor CCA immunosurveillance. In preclinical murine models of cholangitis challenged with syngeneic CCA, PBC (but not PSC) reduced the frequency of CCA development and delayed tumor growth kinetics. This PBC-related effect appeared specific to CCA as it was not observed against other cancers, including hepatocellular carcinoma. The protective effect of PBC was relying on type 1 and type 2 T cell responses and, to a lesser extent, on B cells. Single-cell TCR/RNA sequencing revealed the existence of TCR clonotypes shared between the liver and CCA tumor of a PBC host. Altogether, these results evidence a mechanistic overlapping between autoimmunity and cancer immunosurveillance in the biliary tract.
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Affiliation(s)
- Juliette Paillet
- Equipe 11 labellisée par la Ligue Nationale contre le Cancer, Centre de Recherche des Cordeliers, Institut National de la Santé et de la Recherche Médicale U1138, Université de Paris, Sorbonne Université, Paris, France
- Metabolomics and Cell Biology Platforms, Gustave Roussy Cancer Campus, Villejuif, France
- Université Paris-Saclay, Faculté de Médecine, Kremlin-Bicêtre, France
| | - Céleste Plantureux
- Equipe 11 labellisée par la Ligue Nationale contre le Cancer, Centre de Recherche des Cordeliers, Institut National de la Santé et de la Recherche Médicale U1138, Université de Paris, Sorbonne Université, Paris, France
- Metabolomics and Cell Biology Platforms, Gustave Roussy Cancer Campus, Villejuif, France
- Université Paris-Saclay, Faculté de Médecine, Kremlin-Bicêtre, France
| | - Sarah Lévesque
- Equipe 11 labellisée par la Ligue Nationale contre le Cancer, Centre de Recherche des Cordeliers, Institut National de la Santé et de la Recherche Médicale U1138, Université de Paris, Sorbonne Université, Paris, France
- Metabolomics and Cell Biology Platforms, Gustave Roussy Cancer Campus, Villejuif, France
- Université Paris-Saclay, Faculté de Médecine, Kremlin-Bicêtre, France
| | - Julie Le Naour
- Equipe 11 labellisée par la Ligue Nationale contre le Cancer, Centre de Recherche des Cordeliers, Institut National de la Santé et de la Recherche Médicale U1138, Université de Paris, Sorbonne Université, Paris, France
- Metabolomics and Cell Biology Platforms, Gustave Roussy Cancer Campus, Villejuif, France
- Université Paris-Saclay, Faculté de Médecine, Kremlin-Bicêtre, France
| | - Gautier Stoll
- Equipe 11 labellisée par la Ligue Nationale contre le Cancer, Centre de Recherche des Cordeliers, Institut National de la Santé et de la Recherche Médicale U1138, Université de Paris, Sorbonne Université, Paris, France
- Metabolomics and Cell Biology Platforms, Gustave Roussy Cancer Campus, Villejuif, France
| | - Allan Sauvat
- Equipe 11 labellisée par la Ligue Nationale contre le Cancer, Centre de Recherche des Cordeliers, Institut National de la Santé et de la Recherche Médicale U1138, Université de Paris, Sorbonne Université, Paris, France
- Metabolomics and Cell Biology Platforms, Gustave Roussy Cancer Campus, Villejuif, France
| | - Pamela Caudana
- Institut Curie, Paris Sciences et Lettres Research University, Institut National de la Santé et de la Recherche Médicale U932, Paris, France
| | - Jimena Tosello Boari
- Institut Curie, Paris Sciences et Lettres Research University, Institut National de la Santé et de la Recherche Médicale U932, Paris, France
| | - Norma Bloy
- Equipe 11 labellisée par la Ligue Nationale contre le Cancer, Centre de Recherche des Cordeliers, Institut National de la Santé et de la Recherche Médicale U1138, Université de Paris, Sorbonne Université, Paris, France
- Metabolomics and Cell Biology Platforms, Gustave Roussy Cancer Campus, Villejuif, France
- Université Paris-Saclay, Faculté de Médecine, Kremlin-Bicêtre, France
| | - Sylvie Lachkar
- Equipe 11 labellisée par la Ligue Nationale contre le Cancer, Centre de Recherche des Cordeliers, Institut National de la Santé et de la Recherche Médicale U1138, Université de Paris, Sorbonne Université, Paris, France
- Metabolomics and Cell Biology Platforms, Gustave Roussy Cancer Campus, Villejuif, France
| | - Isabelle Martins
- Equipe 11 labellisée par la Ligue Nationale contre le Cancer, Centre de Recherche des Cordeliers, Institut National de la Santé et de la Recherche Médicale U1138, Université de Paris, Sorbonne Université, Paris, France
- Metabolomics and Cell Biology Platforms, Gustave Roussy Cancer Campus, Villejuif, France
| | | | - Andrea Checcoli
- Institut Curie, Paris Sciences et Lettres Research University, Paris, France
- Institut National de la Santé et de la Recherche Médicale U900, Paris, France
| | | | | | | | - Juliette Hamroune
- Institut National de la Santé et de la Recherche Médicale U1016, Institut Cochin, Paris, France
| | - Franck Letourneur
- Institut National de la Santé et de la Recherche Médicale U1016, Institut Cochin, Paris, France
| | - Gwennhael Autret
- Université de Paris, Paris Cardiovascular Research Centre, Institut National de la Santé et de la Recherche Médicale U970, Paris, France
| | - Patrick S.C. Leung
- Division of Rheumatology/Allergy and Clinical Immunology, University of California, Davis School of Medicine, Davis, CA
| | - M. Eric Gershwin
- Division of Rheumatology/Allergy and Clinical Immunology, University of California, Davis School of Medicine, Davis, CA
| | - Jie S. Zhu
- Department of Chemistry, University of California, Davis, Davis, CA
| | - Mark J. Kurth
- Department of Chemistry, University of California, Davis, Davis, CA
| | - Bouchra Lekbaby
- Institut National de la Santé et de la Recherche Médicale U938, Centre de Recherche Saint-Antoine, Sorbonne Université, Paris, France
| | - Jérémy Augustin
- Institut National de la Santé et de la Recherche Médicale U938, Centre de Recherche Saint-Antoine, Sorbonne Université, Assistance Publique-Hôpitaux de Paris, Hôpital Henri-Mondor, Département de Pathologie, Paris, France
| | - Youra Kim
- Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Shashi Gujar
- Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
- Beatrice Hunter Cancer Research Institute, Halifax, Nova Scotia, Canada
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Cédric Coulouarn
- Institut National de la Santé et de la Recherche Médicale, Université de Rennes 1, Chemistry, Oncogenesis Stress Signaling, UMR_S 1242, Centre de Lutte contre le Cancer Eugène Marquis, Rennes, France
| | - Laura Fouassier
- Institut National de la Santé et de la Recherche Médicale U938, Centre de Recherche Saint-Antoine, Sorbonne Université, Paris, France
| | - Laurence Zitvogel
- Institut National de la Santé et de la Recherche Médicale U1015, Université Paris-Saclay, Gustave Roussy Cancer Campus, Villejuif, France
| | - Eliane Piaggio
- Centre d'Investigation Clinique Biothérapie 1428, Institut Curie, Paris, France
| | - Chantal Housset
- Institut National de la Santé et de la Recherche Médicale U938, Centre de Recherche Saint-Antoine, Sorbonne Université, Paris, France
- Assistance Publique-Hôpitaux de Paris, Reference Center for Inflammatory Biliary Diseases and Autoimmune Hepatitis, Department of Hepatology, Saint-Antoine Hospital, Paris, France
| | - Patrick Soussan
- Institut National de la Santé et de la Recherche Médicale U938, Centre de Recherche Saint-Antoine, Sorbonne Université, Paris, France
| | - Maria Chiara Maiuri
- Equipe 11 labellisée par la Ligue Nationale contre le Cancer, Centre de Recherche des Cordeliers, Institut National de la Santé et de la Recherche Médicale U1138, Université de Paris, Sorbonne Université, Paris, France
- Metabolomics and Cell Biology Platforms, Gustave Roussy Cancer Campus, Villejuif, France
| | - Guido Kroemer
- Equipe 11 labellisée par la Ligue Nationale contre le Cancer, Centre de Recherche des Cordeliers, Institut National de la Santé et de la Recherche Médicale U1138, Université de Paris, Sorbonne Université, Paris, France
- Metabolomics and Cell Biology Platforms, Gustave Roussy Cancer Campus, Villejuif, France
- Institut Universitaire de France, Paris, France
- Pôle de Biologie, Hôpital Européen Georges Pompidou, Assistance Publique-Hôpitaux de Paris, Paris, France
- Suzhou Institute for Systems Medicine, Chinese Academy of Medical Sciences, Suzhou, China
- Karolinska Institute, Department of Women's and Children's Health, Karolinska University Hospital, Stockholm, Sweden
| | - Jonathan G. Pol
- Equipe 11 labellisée par la Ligue Nationale contre le Cancer, Centre de Recherche des Cordeliers, Institut National de la Santé et de la Recherche Médicale U1138, Université de Paris, Sorbonne Université, Paris, France
- Metabolomics and Cell Biology Platforms, Gustave Roussy Cancer Campus, Villejuif, France
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Freer A, Williams F, Durman S, Hayden J, Trivedi PJ, Armstrong MJ. Home-based exercise in patients with refractory fatigue associated with primary biliary cholangitis: a protocol for the EXerCise Intervention in cholesTatic LivEr Disease (EXCITED) feasibility trial. BMJ Open Gastroenterol 2021; 8:bmjgast-2020-000579. [PMID: 33707216 PMCID: PMC7957137 DOI: 10.1136/bmjgast-2020-000579] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 01/19/2021] [Accepted: 01/24/2021] [Indexed: 12/26/2022] Open
Abstract
INTRODUCTION Fatigue is the most commonly reported symptom of the liver disease primary biliary cholangitis (PBC). It affects 40%-80% of patients, has no effective treatment and is associated with heightened mortality risk. The pathogenesis is unknown, but muscle bioenergetic abnormalities have been proposed to contribute. Directly observed exercise has been shown to attenuate symptoms in small groups; however, due to the rare nature of the disease, home-based interventions need to be evaluated for feasibility, safety and efficacy. METHODS AND ANALYSIS This is a phase 1/pilot, single-arm, open-label clinical trial evaluating a novel home-based exercise programme in patients with PBC with severe fatigue. Forty patients with moderate-severe fatigue (PBC40 fatigue domain score >33; other causes of fatigue excluded) will be selected using a convenience sampling method. A 12-week home-based exercise programme, consisting of individualised resistance, aerobic exercises and telephone health calls (first 6 weeks only), will be delivered. Measures of fatigue (PBC40 fatigue domain; fatigue impact scale), quality of life, sleep (Epworth Sleep Score), physical activity, anxiety and depression, aerobic exercise capacity (incremental shuttle walk test; Duke Activity Status Index) and functional capacity (short physical performance battery) will be assessed at baseline and at 6 and 12 weeks following the intervention. ETHICS AND DISSEMINATION The protocol is approved by the National Research Ethics Service Committee London (IRAS 253115). Recruitment commenced in April 2019 and ended in March 2020. Participant follow-up is due to finish by December 2020. Findings will be disseminated through peer-reviewed publication, conference presentation and social media. TRIAL REGISTRATION NUMBER NCT04265235.
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Affiliation(s)
- Alice Freer
- NIHR Birmingham BRC and Centre for Liver and Gastrointestinal Research, University of Birmingham, Birmingham, UK.,Liver Unit, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Felicity Williams
- NIHR Birmingham BRC and Centre for Liver and Gastrointestinal Research, University of Birmingham, Birmingham, UK.,Institute of Immunology and Ageing, University of Birmingham, Birmingham, UK
| | - Simon Durman
- Department of Physiotherapy, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Jennifer Hayden
- Liver Unit, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Palak J Trivedi
- NIHR Birmingham BRC and Centre for Liver and Gastrointestinal Research, University of Birmingham, Birmingham, UK .,Liver Unit, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK.,Centre for Liver and Gastrointestinal Research, University of Birmingham, Birmingham, UK
| | - Matthew J Armstrong
- Liver Unit, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
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Abstract
PURPOSE OF REVIEW Primary biliary cholangitis (PBC) is characterized by autoimmune damage of intrahepatic bile ducts associated with a loss of tolerance to mitochondrial antigens. PBC etiopathogenesis is intriguing because of different perplexing features, namely: a) although mitochondria are present in all cell types and tissues, the damage is mainly restricted to biliary epithelial cells (BECs); b) despite being an autoimmune disorder, it does not respond to immunosuppressive drugs but rather to ursodeoxycholic acid, a bile salt that induces HCO3- rich choleresis; c) the overwhelming female preponderance of the disease remains unexplained. Here we present an etiopathogenic view of PBC which sheds light on these puzzling facts of the disease. RECENT FINDINGS PBC develops in patients with genetic predisposition to autoimmunity in whom epigenetic mechanisms silence the Cl-/HCO3- exchanger AE2 in both cholangiocytes and lymphoid cells. Defective AE2 function can produce BECs damage as a result of decreased biliary HCO3- secretion with disruption of the protective alkaline umbrella that normally prevents the penetration of toxic apolar bile salts into cholangiocytes. AE2 dysfunction also causes increased intracellular pH (pHi) in cholangiocytes, leading to the activation of soluble adenylyl cyclase, which sensitizes BECs to bile salt-induced apoptosis. Recently, mitophagy was found to be inhibited by cytosolic alkalization and stimulated by acidification. Accordingly, we propose that AE2 deficiency may disturb mitophagy in BECs, thus, promoting the accumulation of defective mitochondria, oxidative stress and presentation of mitochondrial antigens to the immune cells. As women possess a more acidic endolysosomal milieu than men, mitophagy might be more affected in women in an AE2-defective background. Apart from affecting BECs function, AE2 downregulation in lymphocytes may also contribute to alter immunoregulation facilitating autoreactive T-cell responses. SUMMARY PBC can be considered as a disorder of Cl-/HCO3- exchange in individuals with genetic predisposition to autoimmunity.
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Affiliation(s)
- Jesús Prieto
- Center for Applied Medical Research (Centro de Investigación Médica Aplicada, CIMA), University of Navarra, Pamplona
| | - Jesus M. Banales
- Department of Liver and Gastrointestinal Diseases, Biodonostia Health Research Institute – Donostia University Hospital – University of the Basque Country (UPV/EHU), San Sebastian
- National Institute for the Study of Liver and Gastrointestinal Diseases (CIBERehd, ‘Instituto de Salud Carlos III’)
- IKERBASQUE, Basque Foundation for Science, Bilbao
| | - Juan F. Medina
- Unit of Medical Training, School of Medicine, University of Navarra, Pamplona, Spain
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Arenas F, Hervías I, Sáez E, Melero S, Prieto J, Parés A, Medina JF. Promoter hypermethylation of the AE2/SLC4A2 gene in PBC. JHEP Rep 2019; 1:145-153. [PMID: 32039364 PMCID: PMC7001545 DOI: 10.1016/j.jhepr.2019.05.006] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 05/13/2019] [Accepted: 05/16/2019] [Indexed: 12/12/2022] Open
Abstract
Background & Aims Patients with primary biliary cholangitis (PBC) exhibit reduced AE2/SLC4A2 gene expression in the liver and peripheral blood mononuclear cells (PBMCs). AE2 encodes a Cl–/HCO3– exchanger involved in biliary bicarbonate secretion and intracellular pH regulation. Reduced AE2 expression in PBC may be pathogenic, as Ae2-knockout mice reproduce characteristic PBC features. Herein, we aimed to identify CpG-methylation abnormalities in AE2 promoter regions that might contribute to the reduced gene transcription in PBC livers and PBMCs. Methods CpG-cytosine methylation rates were interrogated at 1-base pair resolution in upstream and alternate AE2 promoter regions through pyrosequencing of bisulphite-modified genomic DNA from liver specimens and PBMCs. AE2a and alternative AE2b1 and AE2b2 mRNA levels were measured by real-time PCR. Human lymphoblastoid-T2 cells were treated with 5-aza-2´-deoxycytidine for demethylation assays. Results AE2 promoters were found to be hypermethylated in PBC livers compared to normal and diseased liver specimens. Receiver operating characteristic (ROC) curve analysis showed that minimal CpG-hypermethylation clusters of 3 AE2a-CpG sites and 4 alternate-AE2b2-CpG sites specifically differentiated PBC from normal and diseased controls, with mean methylation rates inversely correlating with respective transcript levels. Additionally, in PBMCs a minimal cluster of 3 hypermethylated AE2a-CpG sites distinguished PBC from controls, and mean methylation rates correlated negatively with AE2a mRNA levels in these immune cells. Alternate AE2b2/AE2b1 promoters in PBMCs were constitutively hypermethylated, in line with absent alternative mRNA expression in diseased and healthy PBMCs. Demethylation assays treating lymphoblastoid-T2 cells with 5-aza-2´-deoxycytidine triggered AE2b2/AE2b1 expression and upregulated AE2a-promoter expression. Conclusions Disease-specific hypermethylation of AE2 promoter regions and subsequent downregulation of AE2-gene expression in the liver and PBMCs of patients with PBC might be critically involved in the pathogenesis of this complex disease. Lay summary Primary biliary cholangitis (PBC) is a chronic immune-associated cholestatic liver disease with unclear complex/multifactorial etiopathogenesis affecting mostly middle-aged women. Patients with PBC exhibit reduced expression of the AE2/SLC4A2 gene. Herein, we found that AE2 promoter regions are hypermethylated in the liver and peripheral blood mononuclear cells of patients with PBC. This increased methylation is associated with downregulated AE2-gene expression, which might contribute to the pathogenesis of PBC. Therefore, novel epigenetic targets may improve treatment in patients with PBC who respond poorly to current pharmacological therapies. Patients with PBC have higher AE2 CpG methylation in upstream AE2a and/or AE2b2/AE2b1 promoter regions in liver and PBMCs. Combined methylation rates of 2 minimal CpG-clusters in the liver and 1 minimal CpG-cluster in PBMCs specifically distinguished PBC from normal and diseased controls. Methylation rates of AE2 promoter regions inversely correlated with levels of respective AE2 mRNAs in liver and PBMCs. Alternate AE2b2/AE2b1 promoter regions were found to be densely methylated in both normal and diseased PBMC samples.
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Affiliation(s)
- Fabián Arenas
- Division of Gene Therapy and Hepatology, CIMA, School of Medicine and Clinic University of Navarra, and Ciberehd, Pamplona
| | - Isabel Hervías
- Division of Gene Therapy and Hepatology, CIMA, School of Medicine and Clinic University of Navarra, and Ciberehd, Pamplona
| | - Elena Sáez
- Division of Gene Therapy and Hepatology, CIMA, School of Medicine and Clinic University of Navarra, and Ciberehd, Pamplona
| | - Saida Melero
- Division of Gene Therapy and Hepatology, CIMA, School of Medicine and Clinic University of Navarra, and Ciberehd, Pamplona
| | - Jesús Prieto
- Division of Gene Therapy and Hepatology, CIMA, School of Medicine and Clinic University of Navarra, and Ciberehd, Pamplona
| | - Albert Parés
- Liver Unit, Hospital Clinic, IDIBAPS, University of Barcelona, and Ciberehd, Barcelona, Spain
| | - Juan F. Medina
- Division of Gene Therapy and Hepatology, CIMA, School of Medicine and Clinic University of Navarra, and Ciberehd, Pamplona
- Corresponding author. Address: Division of Gene Therapy and Hepatology, Center for Applied Medical Research (CIMA) University of Navarra School of Medicine, Pamplona, Spain.
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Concepcion AR, Salas JT, Sáez E, Sarvide S, Ferrer A, Portu A, Uriarte I, Hervás-Stubbs S, Oude Elferink RPJ, Prieto J, Medina JF. CD8+ T cells undergo activation and programmed death-1 repression in the liver of aged Ae2a,b-/- mice favoring autoimmune cholangitis. Oncotarget 2016; 6:28588-606. [PMID: 26396175 PMCID: PMC4745679 DOI: 10.18632/oncotarget.5665] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 08/31/2015] [Indexed: 12/15/2022] Open
Abstract
UNLABELLED Primary biliary cirrhosis (PBC) is a chronic cholestatic disease of unknown etiopathogenesis showing progressive autoimmune-mediated cholangitis. In PBC patients, the liver and lymphocytes exhibit diminished expression of AE2/SLC4A2, a Cl-/HCO3- anion exchanger involved in biliary bicarbonate secretion and intracellular pH regulation. Decreased AE2 expression may be pathogenic as Ae2a,b(-/-) mice reproduce hepatobiliary and immunological features resembling PBC. To understand the role of AE2 deficiency for autoimmunity predisposition we focused on the phenotypic changes of T cells that occur over the life-span of Ae2a,b(-/-) mice. At early ages (1-9 months), knockout mice had reduced numbers of intrahepatic T cells, which exhibited increased activation, programmed-cell-death (PD)-1 expression, and apoptosis. Moreover, young knockouts had upregulated PD-1 ligand (PD-L1) on bile-duct cells, and administration of neutralizing anti-PD-L1 antibodies prevented their intrahepatic T-cell deletion. Older (≥ 10 months) knockouts, however, showed intrahepatic accumulation of cytotoxic CD8(+) T cells with downregulated PD-1 and diminished apoptosis. In-vitro DNA demethylation with 5-aza-2'-deoxycytidine partially reverted PD-1 downregulation of intrahepatic CD8(+) T cells from aged knockouts. CONCLUSION Early in life, AE2 deficiency results in intrahepatic T-cell activation and PD-1/PD-L1 mediated deletion. With aging, intrahepatic CD8+ T cells epigenetically suppress PD-1, and their consequential expansion and further activation favor autoimmune cholangitis.
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Affiliation(s)
- Axel R Concepcion
- Center for Applied Medical Research (CIMA), School of Medicine and Clinic University of Navarra, and CIBERehd, Pamplona, Spain
| | - January T Salas
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Elena Sáez
- Center for Applied Medical Research (CIMA), School of Medicine and Clinic University of Navarra, and CIBERehd, Pamplona, Spain
| | - Sarai Sarvide
- Center for Applied Medical Research (CIMA), School of Medicine and Clinic University of Navarra, and CIBERehd, Pamplona, Spain
| | - Alex Ferrer
- Department of Immunology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Ainhoa Portu
- Center for Applied Medical Research (CIMA), School of Medicine and Clinic University of Navarra, and CIBERehd, Pamplona, Spain
| | - Iker Uriarte
- Center for Applied Medical Research (CIMA), School of Medicine and Clinic University of Navarra, and CIBERehd, Pamplona, Spain
| | - Sandra Hervás-Stubbs
- Center for Applied Medical Research (CIMA), School of Medicine and Clinic University of Navarra, and CIBERehd, Pamplona, Spain
| | - Ronald P J Oude Elferink
- Tytgat Institute for Liver and Intestinal Research, Academic Medical Center, Amsterdam, The Netherlands
| | - Jesús Prieto
- Center for Applied Medical Research (CIMA), School of Medicine and Clinic University of Navarra, and CIBERehd, Pamplona, Spain
| | - Juan F Medina
- Center for Applied Medical Research (CIMA), School of Medicine and Clinic University of Navarra, and CIBERehd, Pamplona, Spain
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Abstract
The immune-mediated hepatobiliary diseases, primary biliary cirrhosis and primary sclerosing cholangitis are relatively rare, albeit and account for a significant amount of liver transplant activity and liver-related mortality globally. Precise disease mechanisms are yet to be described although a contributory role of genetic predisposition is firmly established. In addition to links with the major histocompatibility complex, a number of associations outside this region harbor additional loci which underscore the fundamental role of breaks in immune tolerance and mucosal immunogenicity in the pathogenesis of autoimmune biliary disease. We provide an overview of these key discoveries before discussing putative avenues of therapeutic exploitation based on existing findings.
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Mechanisms of tissue injury in autoimmune liver diseases. Semin Immunopathol 2014; 36:553-68. [PMID: 25082647 DOI: 10.1007/s00281-014-0439-3] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Accepted: 06/24/2014] [Indexed: 02/06/2023]
Abstract
Autoimmune diseases affecting the liver are mainly represented by autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC). The characteristic morphologic patterns of injury are a chronic hepatitis pattern of damage in AIH, destruction of small intrahepatic bile ducts in PBC and periductal fibrosis and inflammation involving larger bile ducts in PSC. The factors responsible for initiation and perpetuation of the injury in all the three autoimmune liver diseases are not understood completely but are likely to be environmental triggers on the background of genetic variation in immune regulation. In this review, we summarise the current understanding of the mechanisms underlying the breakdown of self-tolerance in autoimmune liver diseases.
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Concepcion AR, Salas JT, Sarvide S, Sáez E, Ferrer A, López M, Portu A, Banales JM, Hervás-Stubbs S, Oude Elferink RPJ, Prieto J, Medina JF. Anion exchanger 2 is critical for CD8(+) T cells to maintain pHi homeostasis and modulate immune responses. Eur J Immunol 2014; 44:1341-51. [PMID: 24515893 DOI: 10.1002/eji.201344218] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2013] [Revised: 12/24/2013] [Accepted: 02/04/2014] [Indexed: 01/11/2023]
Abstract
Mitogenic stimulation of lymphocytes involves alkalinization of intracellular pH (pHi ). Subsequent pHi regulation may involve HCO3 (-) extrusion through Cl(-) /HCO3 (-) exchangers and/or Na(+) -HCO3 (-) co-transporters with acid-loading capability. Abnormalities in these mechanisms could result in immune dysfunctions, as suggested by the CD8(+) T-cell expansion encountered in mice lacking Ae2 (a widely expressed acid loader with electroneutral and Na(+) -independent Cl(-) /HCO3 (-) anion-exchange activity). Here we report that CD8(+) T cells but not CD4(+) T cells or other lymphocyte populations, are crucially dependent on Ae2 for pHi regulation. While total lymphocytes (including isolated CD4(+) T cells) exhibit Ae1 expression and Na(+) -HCO3 (-) co-transport with acidifying potential, CD8(+) T cells lack these acid-loading mechanisms. In Ae2-KO mice, CD4(+) but not CD8(+) T cells upregulate these potential Ae2 surrogates. As a consequence, Ae2-KO CD8(+) T cells exhibit alkalinized pHi , and dramatically increase their pHi upon CD3 stimulation. Moreover, stimulated Ae2-deficient CD8(+) T cells show enhanced intracellular production of IL-2 and membrane expression of its receptor IL-2Rα, together with increased cell proliferation and activation. These findings demonstrate that CD8(+) T cells are critically dependent on Ae2 for pHi homeostasis and tuning of cell proliferation and activation. Ae2 thus constitutes a novel target to modulate CD8(+) T-cell responses.
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Affiliation(s)
- Axel R Concepcion
- Center for Applied Medical Research (CIMA), Clinic and School of Medicine University of Navarra, Pamplona, Spain; CIBERehd, the "Carlos III" Institute of Health, Madrid, Spain
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Trivedi PJ, Adams DH. Mucosal immunity in liver autoimmunity: A comprehensive review. J Autoimmun 2013; 46:97-111. [DOI: 10.1016/j.jaut.2013.06.013] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Accepted: 06/19/2013] [Indexed: 12/14/2022]
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14
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Trivedi PJ, Hirschfield GM. Treatment of autoimmune liver disease: current and future therapeutic options. Ther Adv Chronic Dis 2013; 4:119-41. [PMID: 23634279 DOI: 10.1177/2040622313478646] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Autoimmune liver disease spans three predominant processes, from the interface hepatitis of autoimmune hepatitis to the lymphocytic cholangitis of primary biliary cirrhosis, and finally the obstructive fibrosing sclerotic cholangiopathy of primary sclerosing cholangitis. Although all autoimmune in origin, they differ in their epidemiology, presentation and response to immunosuppressive therapy and bile acid based treatments. With an ongoing better appreciation of disease aetiology and pathogenesis, treatment is set ultimately to become more rational. We provide an overview of current and future therapies for patients with autoimmune liver disease, with an emphasis placed on some of the evidence that drives current practice.
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Affiliation(s)
- Palak J Trivedi
- Centre for Liver Research and NIHR Biomedical Research Unit, University of Birmingham, Birmingham, UK
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15
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Abstract
Primary biliary cirrhosis (PBC) is a chronic inflammatory autoimmune disease that mainly targets the cholangiocytes of the interlobular bile ducts in the liver. It is a rare disease with prevalence of less than one in 2000. Its prevalence in developing countries is increasing presumably because of growth in recognition and knowledge of the disease. PBC is thought to result from a combination of multiple genetic factors and superimposed environmental triggers. The contribution of the genetic predisposition is evidenced by familial clustering. Several risk factors, including exposure to infectious agents and chemical xenobiotics, have been suggested. Common symptoms of the disease are fatigue and pruritus, but most patients are asymptomatic at first presentation. The prognosis of PBC has improved because of early diagnosis and use of ursodeoxycholic acid, the only established medical treatment for this disorder. When administered at adequate doses of 13–15 mg/kg/day, up to two out of three patients with PBC may have a normal life expectancy without additional therapeutic measures. However, some patients do not respond adequately to ursodeoxycholic acid and might need alternative therapeutic approaches.
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Affiliation(s)
- Nadya Al-Harthy
- Gastroenterology and Hepatology, Royal Hospital, Muscat, Oman
| | - Teru Kumagi
- Gastroenterology and Metabology, Ehime University Graduate School of Medicine, Ehime, Japan
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