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Zou J, Li J, Wang X, Tang D, Chen R. Neuroimmune modulation in liver pathophysiology. J Neuroinflammation 2024; 21:188. [PMID: 39090741 PMCID: PMC11295927 DOI: 10.1186/s12974-024-03181-w] [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: 12/11/2023] [Accepted: 07/19/2024] [Indexed: 08/04/2024] Open
Abstract
The liver, the largest organ in the human body, plays a multifaceted role in digestion, coagulation, synthesis, metabolism, detoxification, and immune defense. Changes in liver function often coincide with disruptions in both the central and peripheral nervous systems. The intricate interplay between the nervous and immune systems is vital for maintaining tissue balance and combating diseases. Signaling molecules and pathways, including cytokines, inflammatory mediators, neuropeptides, neurotransmitters, chemoreceptors, and neural pathways, facilitate this complex communication. They establish feedback loops among diverse immune cell populations and the central, peripheral, sympathetic, parasympathetic, and enteric nervous systems within the liver. In this concise review, we provide an overview of the structural and compositional aspects of the hepatic neural and immune systems. We further explore the molecular mechanisms and pathways that govern neuroimmune communication, highlighting their significance in liver pathology. Finally, we summarize the current clinical implications of therapeutic approaches targeting neuroimmune interactions and present prospects for future research in this area.
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Affiliation(s)
- Ju Zou
- Hunan Key Laboratory of Viral Hepatitis, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
- Department of Infectious Diseases, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
| | - Jie Li
- Hunan Key Laboratory of Viral Hepatitis, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
- Department of Infectious Diseases, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
| | - Xiaoxu Wang
- Hunan Key Laboratory of Viral Hepatitis, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
- Department of Infectious Diseases, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
| | - Daolin Tang
- Department of Surgery, UT Southwestern Medical Center, Dallas, TX, USA
| | - Ruochan Chen
- Hunan Key Laboratory of Viral Hepatitis, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China.
- Department of Infectious Diseases, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China.
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China.
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Bäckström T, Doverskog M, Blackburn TP, Scharschmidt BF, Felipo V. Allopregnanolone and its antagonist modulate neuroinflammation and neurological impairment. Neurosci Biobehav Rev 2024; 161:105668. [PMID: 38608826 DOI: 10.1016/j.neubiorev.2024.105668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 03/18/2024] [Accepted: 04/07/2024] [Indexed: 04/14/2024]
Abstract
Neuroinflammation accompanies several brain disorders, either as a secondary consequence or as a primary cause and may contribute importantly to disease pathogenesis. Neurosteroids which act as Positive Steroid Allosteric GABA-A receptor Modulators (Steroid-PAM) appear to modulate neuroinflammation and their levels in the brain may vary because of increased or decreased local production or import from the systemic circulation. The increased synthesis of steroid-PAMs is possibly due to increased expression of the mitochondrial cholesterol transporting protein (TSPO) in neuroinflammatory tissue, and reduced production may be due to changes in the enzymatic activity. Microglia and astrocytes play an important role in neuroinflammation, and their production of inflammatory mediators can be both activated and inhibited by steroid-PAMs and GABA. What is surprising is the finding that both allopregnanolone, a steroid-PAM, and golexanolone, a novel GABA-A receptor modulating steroid antagonist (GAMSA), can inhibit microglia and astrocyte activation and normalize their function. This review focuses on the role of steroid-PAMs in neuroinflammation and their importance in new therapeutic approaches to CNS and liver disease.
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Affiliation(s)
| | | | | | | | - Vicente Felipo
- Laboratory of Neurobiology, Centro de Investigación Príncipe Felipe, Valencia, Spain
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Younossi ZM, Kremer AE, Swain MG, Jones D, Bowlus C, Trauner M, Henry L, Gerber L. Assessment of fatigue and its impact in chronic liver disease. J Hepatol 2024:S0168-8278(24)00276-9. [PMID: 38670320 DOI: 10.1016/j.jhep.2024.04.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 03/19/2024] [Accepted: 04/12/2024] [Indexed: 04/28/2024]
Abstract
Patient-reported outcomes (PROs), such as health-related quality of life (HRQL), are important outcome measures for patients with chronic liver diseases (CLDs). Presence of cirrhosis and advanced liver disease have been associated with worsened HRQL and fatigue. On the other hand, some patients with earlier stages of CLD also experience fatigue, causing PRO impairment. Treatment for some CLDs may improve HRQL and, sometimes, levels of fatigue. We aimed to provide an in-depth expert review of concepts related to fatigue and HRQL in patients with primary biliary cholangitis, hepatitis C virus and MASLD (metabolic dysfunction-associated steatotic liver disease). A panel of experts in fatigue and CLD reviewed and discussed the literature and collaborated to provide this expert review of fatigue in CLD. Herein, we review and report on the complexity of fatigue, highlighting that it is comprised of peripheral (neuromuscular failure, often in conjunction with submaximal cardiorespiratory function) and central (central nervous system dysfunction) causes. Fatigue and HRQL are measured using validated self-report instruments. Additionally, fatigue can be measured through objective tests (e.g. grip strength). Fatigue has deleterious effects on HRQL and one's ability to be physically active and socially engaged but does not always correlate with CLD severity. Treatments for hepatitis C virus and MASLD can improve levels of fatigue and HRQL, but current treatments for primary biliary cholangitis do not seem to affect levels of fatigue. We conclude that obtaining PRO data, including on HRQL and fatigue, is essential for determining the comprehensive burden of CLD and its potential treatments.
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Affiliation(s)
- Zobair M Younossi
- Beatty Liver and Obesity Research Program, Inova Health System, Falls Church, VA, USA; The Global Liver Council, Washington DC, USA.
| | - Andreas E Kremer
- Department of Gastroenterology and Hepatology, University Hospital Zürich, University of Zürich, Zürich, Switzerland
| | - Mark G Swain
- Professor of Medicine, Cal Wenzel Family Foundation Chair in Hepatology, University of Calgary Liver Unit, Calgary, Canada
| | - David Jones
- Professor of Liver Immunology, Newcastle University, Newcastle upon Tyne, UK
| | - Christopher Bowlus
- Lena Valente Professor and Chief, Division of Gastroenterology and Hepatology, University of California Davis, United States
| | - Michael Trauner
- Div. of Gastroenterology & Hepatology, Dept. of Internal Medicine III, MedUni Wien, Medical University of Vienna, Austria
| | - Linda Henry
- Beatty Liver and Obesity Research Program, Inova Health System, Falls Church, VA, USA; The Global Liver Council, Washington DC, USA; Center for Outcomes Research in Liver Diseases, Washington DC, USA
| | - Lynn Gerber
- Beatty Liver and Obesity Research Program, Inova Health System, Falls Church, VA, USA; The Global Liver Council, Washington DC, USA
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Bager P, Bossen L, Gantzel R, Grønbæk H. High-dose oral thiamine versus placebo for chronic fatigue in patients with primary biliary cholangitis: A crossover randomized clinical trial. PLoS One 2024; 19:e0301354. [PMID: 38551983 PMCID: PMC10980237 DOI: 10.1371/journal.pone.0301354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 03/10/2024] [Indexed: 04/01/2024] Open
Abstract
BACKGROUND & AIMS Fatigue has high negative impact on many patients with primary biliary cholangitis (PBC) and treatment options are limited. Recently we showed favorable effects of four weeks of high-dose thiamine treatment on fatigue in patients with inflammatory bowel disease. We aimed to investigate the effect and safety of high-dose (600-1800 mg daily) oral thiamine treatment on chronic fatigue in patients with PBC. METHODS Randomized, double-blinded, placebo-controlled crossover trial including patients with severe PBC-related fatigue. Participants were allocated 1:1 to either group 1) 4 weeks of high-dose thiamine, 4 weeks of washout, and 4 weeks of placebo; or group 2) 4 weeks of placebo, washout, and high-dose thiamine, respectively. Fatigue severity was quantified using the fatigue subscale of the PBC-40 questionnaire. The primary outcome was a fatigue reduction of ≥ 5 points after 4 weeks of high-dose thiamine treatment. RESULTS We enrolled 36 patients; 34 completed the study. The overall mean reduction in fatigue was 5.0 points (95% CI: 2.5 to 7.5; p < 0.001) for the combined group 1 and group 2. Crossover analysis showed a mean increase in fatigue of 0.3 points (95% CI: -4.2 to 3.8) after high-dose thiamine treatment compared to a 1.4 points (95% CI: 6.2 to -3.4) mean reduction after placebo (p = 0.55). Only mild and transient adverse events were recorded. CONCLUSION Four weeks of high-dose oral thiamine treatment in patients with PBC was well tolerated and safe. However, high-dose thiamine was not superior to placebo in reducing PBC-related fatigue. TRIAL REGISTRATION The trial was registered in the ClinicalTrials.gov (NCT04893993) and EudraCT (2020-004935-26).
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Affiliation(s)
- Palle Bager
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Lars Bossen
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
| | - Rasmus Gantzel
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
| | - Henning Grønbæk
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
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Zapata M, Pagan-Torres H, Mayo MJ. Systemic Complications of Primary Biliary Cholangitis. Clin Liver Dis 2024; 28:115-128. [PMID: 37945153 DOI: 10.1016/j.cld.2023.07.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
Abstract
Chronic cholestasis is the hallmark clinical feature of primary biliary cholangitis. In addition to progressive liver damage, chronic cholestasis can lead to serious complications, many of which occur outside the liver. Bile acids are ligands for nuclear hormone receptors, and alterations in their concentration disrupt normal functioning of numerous different cell types. This article discusses the clinical presentation, pathophysiology, and management of pruritus (itching), fatigue, osteoporosis, hyperlipidemia, fat-soluble vitamin deficiencies, malignancies, cardiac dysfunction, bacterial cholangitis, cholemic (bile cast) nephropathy, and Sicca syndrome.
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Affiliation(s)
- Mariana Zapata
- University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-8887, USA
| | - Hendrick Pagan-Torres
- University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-8887, USA
| | - Marlyn J Mayo
- University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-8887, USA.
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Faisal A. Understanding fatigue and pruritus in primary biliary cholangitis. Clin Liver Dis (Hoboken) 2024; 23:e0216. [PMID: 38831766 PMCID: PMC11146472 DOI: 10.1097/cld.0000000000000216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Accepted: 04/08/2024] [Indexed: 06/05/2024] Open
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Tanaka A. New Therapies on the Horizon for Primary Biliary Cholangitis. Drugs 2024; 84:1-15. [PMID: 38082142 DOI: 10.1007/s40265-023-01979-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/09/2023] [Indexed: 01/17/2024]
Abstract
Primary biliary cholangitis (PBC) is a chronic cholestatic liver disease that can progress to cirrhosis and hepatic failure if left untreated. Ursodeoxycholic acid (UDCA) was introduced as a first-line drug for PBC around 1990; it remarkably improved patient outcomes, leading to the nomenclature change of PBC in 2015, from primary biliary "cirrhosis" to primary biliary "cholangitis." Nevertheless, 20-30% of patients exhibit an incomplete response to UDCA, resulting in significantly worse outcomes compared to those with a complete response. Therefore, improving the long-term outcomes of patients with an incomplete response to UDCA has been recognized as an unmet need. In addition, patients with PBC often suffer from a variety of debilitating symptoms, such as pruritus, fatigue and sicca syndrome, which significantly impair their health-related quality of life. Thus, appropriate management of these symptoms is currently regarded as another unmet need for PBC treatment. In this review, several compounds and drugs under clinical trials that can potentially solve these unmet needs are comprehensively discussed, and future directions of treatment policy of PBC are proposed for significantly improving long-term outcome as well as health-related quality of life of patients.
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Affiliation(s)
- Atsushi Tanaka
- Department of Medicine, Teikyo University School of Medicine, 2-11-1, Kaga, Itabashi-ku, Tokyo, 173-8605, Japan.
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