1
|
Díaz LA, Arab JP, Louvet A, Bataller R, Arrese M. The intersection between alcohol-related liver disease and nonalcoholic fatty liver disease. Nat Rev Gastroenterol Hepatol 2023; 20:764-783. [PMID: 37582985 DOI: 10.1038/s41575-023-00822-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/07/2023] [Indexed: 08/17/2023]
Abstract
Nonalcoholic fatty liver disease (NAFLD) and alcohol-related liver disease (ALD) are the leading causes of chronic liver disease worldwide. NAFLD and ALD share pathophysiological, histological and genetic features and both alcohol and metabolic dysfunction coexist as aetiological factors in many patients with hepatic steatosis. A diagnosis of NAFLD requires the exclusion of significant alcohol consumption and other causes of liver disease. However, data suggest that significant alcohol consumption is often under-reported in patients classified as having NAFLD and that alcohol and metabolic factors interact to exacerbate the progression of liver disease. In this Review, we analyse existing data on the interaction between alcohol consumption and metabolic syndrome as well as the overlapping features and differences in the pathogenesis of ALD and NAFLD. We also discuss the clinical implications of the coexistence of alcohol consumption, of any degree, in patients with evidence of metabolic derangement as well as the use of alcohol biomarkers to detect alcohol intake. Finally, we summarize the evolving nomenclature of fatty liver disease and describe a recent proposal to classify patients at the intersection of NAFLD and ALD. We propose that, regardless of the presumed aetiology, patients with fatty liver disease should be evaluated for both metabolic syndrome and alcohol consumption to enable better prognostication and a personalized medicine approach.
Collapse
Affiliation(s)
- Luis Antonio Díaz
- Departamento de Gastroenterología, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Juan Pablo Arab
- Departamento de Gastroenterología, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
- Division of Gastroenterology, Department of Medicine, Schulich School of Medicine, Western University & London Health Sciences Centre, London, Ontario, Canada
- Department of Epidemiology and Biostatistics, Schulich School of Medicine, Western University, London, Ontario, Canada
| | - Alexandre Louvet
- Service des Maladies de l'Appareil Digestif, Hôpital Huriez, Lille Cedex, France
- Université Lille Nord de France, Lille, France
- Unité INSERM INFINITE 1286, Lille, France
| | - Ramón Bataller
- Liver Unit, Hospital Clinic, Institut d'Investigacions Biomediques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Marco Arrese
- Departamento de Gastroenterología, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.
| |
Collapse
|
2
|
Wan N, Shi J, Xu J, Huang J, Gan D, Tang M, Li X, Huang Y, Li P. Gasdermin D: A Potential New Auxiliary Pan-Biomarker for the Detection and Diagnosis of Diseases. Biomolecules 2023; 13:1664. [PMID: 38002346 PMCID: PMC10669528 DOI: 10.3390/biom13111664] [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: 10/08/2023] [Revised: 11/10/2023] [Accepted: 11/14/2023] [Indexed: 11/26/2023] Open
Abstract
Pyroptosis is a form of programmed cell death mediated by gasdermins, particularly gasdermin D (GSDMD), which is widely expressed in tissues throughout the body. GSDMD belongs to the gasdermin family, which is expressed in a variety of cell types including epithelial cells and immune cells. It is involved in the regulation of anti-inflammatory responses, leading to its differential expression in a wide range of diseases. In this review, we provide an overview of the current understanding of the major activation mechanisms and effector pathways of GSDMD. Subsequently, we examine the importance and role of GSDMD in different diseases, highlighting its potential as a pan-biomarker. We specifically focus on the biological characteristics of GSDMD in several diseases and its promising role in diagnosis, early detection, and differential diagnosis. Furthermore, we discuss the application of GSDMD in predicting prognosis and monitoring treatment efficacy in cancer. This review proposes a new strategy to guide therapeutic decision-making and suggests potential directions for further research into GSDMD.
Collapse
Affiliation(s)
- Ningyi Wan
- Department of Clinical Laboratory, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
| | - Jing Shi
- Department of Clinical Laboratory, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Jianguo Xu
- Department of Clinical Laboratory, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
| | - Juan Huang
- Department of Information Center, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
| | - Delu Gan
- Department of Clinical Laboratory, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
| | - Min Tang
- Key Laboratory of Medical Diagnostics Designated by Chinese Ministry of Education, Chongqing Medical University, Chongqing 400016, China
| | - Xiaohan Li
- Department of Clinical Laboratory, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
| | - Ying Huang
- Department of Clinical Laboratory, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
| | - Pu Li
- Department of Clinical Laboratory, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
| |
Collapse
|
3
|
MRG15 aggravates non-alcoholic steatohepatitis progression by regulating the mitochondrial proteolytic degradation of TUFM. J Hepatol 2022; 77:1491-1503. [PMID: 35985547 DOI: 10.1016/j.jhep.2022.07.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 06/29/2022] [Accepted: 07/14/2022] [Indexed: 12/04/2022]
Abstract
BACKGROUND & AIMS How hepatic steatosis progresses to non-alcoholic steatohepatitis (NASH) is complicated and remains unclear. The mortality factor 4-like protein 1 (MORF4L1, also called MRG15) was previously identified as a master nuclear chromatin remodeler in the rhythmic regulation of lipid synthesis gene expression in the liver. Whether it also contributes to the progression from liver steatosis to NASH is unclear. METHODS We adopted 2 different murine NASH models, liver biopsies from patients with NASH, and primary mouse and human hepatocyte cultures for functional examination of MRG15 in NASH progression. Immunoprecipitation-mass spectrometry was applied to identify protein partners of MRG15, and CRISPR targeting was used for gene depletion in liver cells in vivo. RESULTS The MRG15 level is increased in the livers of humans and mice with NASH. The inflammatory cytokines in NASH livers stabilize MRG15 by increasing its acetylation. Considerable amounts of MRG15 associate with the outer mitochondrial membrane, where it interacts with and deacetylates the mitochondrial Tu translation elongation factor (TUFM). Deacetylated TUFM, especially at the K82 and K91 sites, is subjected to accelerated degradation by the mitochondrial ClpXP protease system. Reduced liver TUFM consequently results in impaired mitophagy, increased oxidative stress and activation of the NLRP3 inflammasome pathway. Blocking MRG15 expression protects the liver from NASH progression by increasing the stability of liver TUFM. Liver samples from patients with NASH also display a clear reduction in TUFM level, which correlates with increased MRG15 expression. CONCLUSION Collectively, these findings uncover a mitochondrial MRG15-TUFM regulatory pathway that contributes significantly to progression from simple steatosis to NASH, and which could potentially be targeted to treat NASH. LAY SUMMARY The incidence of non-alcoholic fatty liver disease and its progressive form non-alcoholic steatohepatitis (NASH) is increasing, posing a significant global health challenge. Herein, we have uncovered the importance of the MRG15-TUFM pathway in NASH development. This pathway is active in the mitochondria (energy powerhouse of the cell) and could be targeted for the treatment of NASH.
Collapse
|
4
|
Alcohol-Related Liver Disease: An Overview on Pathophysiology, Diagnosis and Therapeutic Perspectives. Biomedicines 2022; 10:biomedicines10102530. [PMID: 36289791 PMCID: PMC9599689 DOI: 10.3390/biomedicines10102530] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 10/01/2022] [Accepted: 10/08/2022] [Indexed: 11/19/2022] Open
Abstract
Alcohol-related liver disease (ALD) refers to a spectrum of liver manifestations ranging from fatty liver diseases, steatohepatitis, and fibrosis/cirrhosis with chronic inflammation primarily due to excessive alcohol use. Currently, ALD is considered as one of the most prevalent causes of liver disease-associated mortality worldwide. Although the pathogenesis of ALD has been intensively investigated, the present understanding of its biomarkers in the context of early clinical diagnosis is not complete, and novel therapeutic targets that can significantly alleviate advanced forms of ALD are limited. While alcohol abstinence remains the primary therapeutic intervention for managing ALD, there are currently no approved medications for treating ALD. Furthermore, given the similarities and the differences between ALD and non-alcoholic fatty liver disease in terms of disease progression and underlying molecular mechanisms, numerous studies have demonstrated that many therapeutic interventions targeting several signaling pathways, including oxidative stress, inflammatory response, hormonal regulation, and hepatocyte death play a significant role in ALD treatment. Therefore, in this review, we summarized several key molecular targets and their modes of action in ALD progression. We also described the updated therapeutic options for ALD management with a particular emphasis on potentially novel signaling pathways.
Collapse
|
5
|
Chen Y, Xu YN, Ye CY, Feng WB, Zhou QT, Yang DH, Wang MW. GLP-1 mimetics as a potential therapy for nonalcoholic steatohepatitis. Acta Pharmacol Sin 2022; 43:1156-1166. [PMID: 34934197 PMCID: PMC9061743 DOI: 10.1038/s41401-021-00836-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 11/29/2021] [Indexed: 12/14/2022] Open
Abstract
Nonalcoholic steatohepatitis (NASH), as a severe form of nonalcoholic fatty liver disease (NAFLD), is characterized by liver steatosis, inflammation, hepatocellular injury and different degrees of fibrosis. The pathogenesis of NASH is complex and multifactorial, obesity and type 2 diabetes mellitus (T2DM) have been implicated as major risk factors. Glucagon-like peptide-1 receptor (GLP-1R) is one of the most successful drug targets of T2DM and obesity, and its peptidic ligands have been proposed as potential therapeutic agents for NASH. In this article we provide an overview of the pathophysiology and management of NASH, with a special focus on the pharmacological effects and possible mechanisms of GLP-1 mimetics in treating NAFLD/NASH, including dual and triple agonists at GLP-1R, glucose-dependent insulinotropic polypeptide receptor or glucagon receptor.
Collapse
Affiliation(s)
- Yan Chen
- grid.8547.e0000 0001 0125 2443Department of Pharmacology, School of Basic Medical Sciences, Fudan University, Shanghai, 200032 China
| | - Ying-na Xu
- grid.8547.e0000 0001 0125 2443Department of Pharmacology, School of Basic Medical Sciences, Fudan University, Shanghai, 200032 China
| | - Chen-yu Ye
- grid.8547.e0000 0001 0125 2443Department of Pharmacology, School of Basic Medical Sciences, Fudan University, Shanghai, 200032 China
| | - Wen-bo Feng
- grid.8547.e0000 0001 0125 2443Department of Pharmacology, School of Basic Medical Sciences, Fudan University, Shanghai, 200032 China
| | - Qing-tong Zhou
- grid.8547.e0000 0001 0125 2443Department of Pharmacology, School of Basic Medical Sciences, Fudan University, Shanghai, 200032 China
| | - De-hua Yang
- grid.419093.60000 0004 0619 8396The CAS Key Laboratory of Receptor Research and The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203 China ,Research Center for Deepsea Bioresources, Sanya, 572025 China
| | - Ming-wei Wang
- grid.8547.e0000 0001 0125 2443Department of Pharmacology, School of Basic Medical Sciences, Fudan University, Shanghai, 200032 China ,grid.419093.60000 0004 0619 8396The CAS Key Laboratory of Receptor Research and The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203 China ,Research Center for Deepsea Bioresources, Sanya, 572025 China ,grid.440637.20000 0004 4657 8879School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210 China
| |
Collapse
|
6
|
Griffett K, Hayes ME, Boeckman MP, Burris TP. The role of REV-ERB in NASH. Acta Pharmacol Sin 2022; 43:1133-1140. [PMID: 35217816 PMCID: PMC9061770 DOI: 10.1038/s41401-022-00883-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 01/28/2022] [Indexed: 02/07/2023] Open
Abstract
REV-ERBs are atypical nuclear receptors as they function as ligand-regulated transcriptional repressors. The natural ligand for the REV-ERBs (REV-ERBα and REV-ERBβ) is heme, and heme-binding results in recruitment of transcriptional corepressor proteins such as N-CoR that mediates repression of REV-ERB target genes. These two receptors regulate a large range of physiological processes including several important in the pathophysiology of non-alcoholic steatohepatitis (NASH). These include carbohydrate and lipid metabolism as well as inflammatory pathways. A number of synthetic REV-ERB agonists have been developed as chemical tools and they show efficacy in animal models of NASH. Here, we will review the functions of REV-ERB with regard to their relevance to NASH as well as the potential to target REV-ERB for treatment of this disease.
Collapse
Affiliation(s)
- Kristine Griffett
- Center for Clinical Pharmacology, Washington University in St. Louis and University of Health Sciences & Pharmacy, St. Louis, MO, 63110, USA
| | - Matthew E Hayes
- University of Florida Genetics Institute, Gainesville, FL, 32610, USA
| | - Michael P Boeckman
- Center for Clinical Pharmacology, Washington University in St. Louis and University of Health Sciences & Pharmacy, St. Louis, MO, 63110, USA
| | - Thomas P Burris
- University of Florida Genetics Institute, Gainesville, FL, 32610, USA.
| |
Collapse
|
7
|
Wang Y, Zhang J, Chen J, Wang D, Yu Y, Qiu P, Wang Q, Zhao W, Li Z, Lei T. Ch25h and 25-HC prevent liver steatosis through regulation of cholesterol metabolism and inflammation. Acta Biochim Biophys Sin (Shanghai) 2022; 54:504-513. [PMID: 35462473 PMCID: PMC9828056 DOI: 10.3724/abbs.2022030] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is currently the most prevalent metabolic disorder all over the world, and lipid metabolic disorders and inflammation are closely associated and contribute to the pathogenesis of NAFLD. Cholesterol 25-hydroxylase (Ch25h) and its product, 25-hydroxycholesterol (25-HC), play important roles in cholesterol homeostasis and inflammation, but whether Ch25h and 25-HC are involved in NAFLD remains uncertain. In this study, we use Ch25h knockout mice, hepatic cells and liver biopsies to explore the role of Ch25h and 25-HC in lipid metabolism and accumulation in liver, determine the molecular mechanism of lipid accumulation and inflammation influenced by Ch25h and 25-HC, and assess the regulatory effects of Ch25h and 25-HC on human NAFLD. Our results indicate that mice lacking Ch25h have normal cholesterol homeostasis with normal diet, but under the condition of high fat diet (HFD), the mice show higher total cholesterol and triglyceride in serum, and prone to hepatic steatosis. Ch25h deficiency reduces the cholesterol efflux regulated by liver X receptor α (LXRα), increases the synthesis of cholesterol mediated by sterol-regulatory element binding protein 2 (SREBP-2), and increases the activation of NLRP3 inflammasome, therefore promotes hepatic steatosis. Collectively, our data suggest that Ch25h and 25-HC play important roles in lipid metabolism and inflammation, thereby exerting anti-NAFLD functions.
Collapse
Affiliation(s)
- Yaqiong Wang
- Department of PathologySchool of Basic Medical SciencesXi’an Jiaotong University Health Science CenterXi’an710061China,Xi’an Blood CenterXi’an710061China
| | - Jin Zhang
- Cardiovascular Research CenterSchool of Basic Medical SciencesXi’an Jiaotong University Health Science CenterXi’an 710061Chinaand
| | - Jie Chen
- Department of PathologySchool of Basic Medical SciencesXi’an Jiaotong University Health Science CenterXi’an710061China,Department of PathologyShannxi Provincial People’s HospitalXi’an710068China
| | - Dan Wang
- Department of PathologySchool of Basic Medical SciencesXi’an Jiaotong University Health Science CenterXi’an710061China
| | - Yang Yu
- Department of PathologySchool of Basic Medical SciencesXi’an Jiaotong University Health Science CenterXi’an710061China
| | - Pei Qiu
- Department of PathologySchool of Basic Medical SciencesXi’an Jiaotong University Health Science CenterXi’an710061China
| | - Qiqi Wang
- Department of PathologySchool of Basic Medical SciencesXi’an Jiaotong University Health Science CenterXi’an710061China
| | - Wenbao Zhao
- Department of PathologySchool of Basic Medical SciencesXi’an Jiaotong University Health Science CenterXi’an710061China
| | - Zhao Li
- Cardiovascular Research CenterSchool of Basic Medical SciencesXi’an Jiaotong University Health Science CenterXi’an 710061Chinaand
| | - Ting Lei
- Department of PathologySchool of Basic Medical SciencesXi’an Jiaotong University Health Science CenterXi’an710061China,Correspondence author. Tel: +86-29-82655189. E-mail:
| |
Collapse
|
8
|
Sohrabi M, Ajdarkosh H, Gholami A, Amirkalali B, Mansorian MR, Aten S, Sohrabi M, Nasiri-Toosi M, Zamani F, Keyvani H. Association between Melatonin Value and Interleukins1B, -18, and -33 Levels in Patients with Different Stages of Non-Alcoholic Fatty Liver Disease. Middle East J Dig Dis 2022; 14:110-117. [PMID: 36619722 PMCID: PMC9489333 DOI: 10.34172/mejdd.2022.263] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Accepted: 10/20/2021] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND: Interaction between immune modulators and inflammatory factors is considered as one of the main underlying pathologies of non-alcoholic fatty liver disease (NAFLD). Hence we aimed to assess the association between these cytokines and melatonin. METHODS: We enrolled adult patients diagnosed with fatty liver by ultrasonography in a crosssectional study. All of them underwent Fibroscan evaluation. The subjects who met the inclusion and exclusion criteria for NAFLD were involved. A normal group who did not have NAFLD, viral or non-viral hepatitis, and without a history of pancreatobiliary surgery, bariatric surgery, and intake of any medication that influence the liver was also selected. The participants were categorized into the three following groups: 1) fibrosis>9.1 kPa and steatosis>290 dbm, 2) fibrosis: 6-9.0 kPa and steatosis 240-290 dbm, and 3) normal group with fibrosis<6.0 kPa and steatosis<240 dbm. Laboratory assessment and a questionnaire including demographic, anthropometric, laboratories, and clinical data were completed for each of them. RESULTS: Totally 97 subjects were enrolled in the present study. The mean age of the subjects was 42.2±11.3 years. 60% of them (59 patients) were female. Serum levels of melatonin, interleukin (IL)-1B, IL-18, and IL-33 increased according to the advancing of NAFLD state. Based on multiple linear regression model, melatonin was significantly associated with IL-1B (β=2.8, P<0.001,95% CI=1.41-4.19), IL-18 (β=0.018, P=0.0005, 95% CI=0.006-0.03), and IL-33 (β=0.31, P=0.045, 95% CI=0.008-0.62) after adjustment for other variables. CONCLUSION: Melatonin level has a strong association with these cytokines. This linkage probably influences on the development and progression of NAFLD. Therefore it can be hypothesized that the therapeutic approach that affects this process may have a significant impact.
Collapse
Affiliation(s)
- Masoudreza Sohrabi
- Gastrointestinal and Liver Diseases Research Center (GILDRC), Iran University of Medical Sciences, Tehran, Iran
| | - Hossein Ajdarkosh
- Gastrointestinal and Liver Diseases Research Center (GILDRC), Iran University of Medical Sciences, Tehran, Iran
| | - Ali Gholami
- Noncommunicable Diseases Research Center, Neyshabur University of Medical Sciences, Neyshabur, Iran,Department of Epidemiology & Biostatistics, School of Public Health, Neyshabur University of Medical Sciences, Neyshabur, Iran
| | - Bahreh Amirkalali
- Gastrointestinal and Liver Diseases Research Center (GILDRC), Iran University of Medical Sciences, Tehran, Iran
| | - Mohsen Reza Mansorian
- Gastrointestinal and Liver Diseases Research Center (GILDRC), Iran University of Medical Sciences, Tehran, Iran
| | - Sima Aten
- Gastrointestinal and Liver Diseases Research Center (GILDRC), Iran University of Medical Sciences, Tehran, Iran
| | - Melika Sohrabi
- Gastrointestinal and Liver Diseases Research Center (GILDRC), Iran University of Medical Sciences, Tehran, Iran
| | - Mohsen Nasiri-Toosi
- Liver transplantation Research Center. Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Farhad Zamani
- Gastrointestinal and Liver Diseases Research Center (GILDRC), Iran University of Medical Sciences, Tehran, Iran
| | - Hossein Keyvani
- Gastrointestinal and Liver Diseases Research Center (GILDRC), Iran University of Medical Sciences, Tehran, Iran,Corresponding Author: Hossein Keyvani, MD Gastrointestinal and Liver Disease Research Center, Firoozgar Hospital, Iran University of Medical Sciences, Tehran, Iran Telefax:+98 21 82141633
| |
Collapse
|
9
|
Zhou F, Sun X. Cholesterol Metabolism: A Double-Edged Sword in Hepatocellular Carcinoma. Front Cell Dev Biol 2021; 9:762828. [PMID: 34869352 PMCID: PMC8635701 DOI: 10.3389/fcell.2021.762828] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Accepted: 10/27/2021] [Indexed: 02/06/2023] Open
Abstract
Hepatocellular carcinoma (HCC) represents a leading cause of cancer-related deaths globally. The rising incidence of metabolic syndrome and its hepatic manifestation, nonalcoholic fatty liver disease (NAFLD), have emerged as the fastest-growing cause of HCC in recent years. Cholesterol, a major lipid component of the cell membrane and lipoprotein particles, is primarily produced and metabolized by the liver. Numerous studies have revealed an increased cholesterol biosynthesis and uptake, reduced cholesterol exportation and excretion in HCC, which all contribute to lipotoxicity, inflammation, and fibrosis, known HCC risk factors. In contrast, some clinical studies have shown that higher cholesterol is associated with a reduced risk of HCC. These contradictory observations imply that the relationship between cholesterol and HCC is far more complex than initially anticipated. Understanding the role of cholesterol and deciphering the underlying molecular events in HCC development is highly relevant to developing new therapies. Here, we discuss the current understanding of cholesterol metabolism in the pathogenesis of NAFLD-associated HCC, and the underlying mechanisms, including the roles of cholesterol in the disruption of normal function of specific cell types and signaling transduction. We also review the clinical progression in evaluating the association of cholesterol with HCC. The therapeutic effects of lowering cholesterol will also be summarized. We also interpret reasons for the contradictory observations from different preclinical and human studies of the roles of cholesterol in HCC, aiming to provide a critical assessment of the potential of cholesterol as a therapeutic target.
Collapse
Affiliation(s)
- Fangli Zhou
- Department of Endocrinology and Metabolism, West China Hospital, Sichuan University, Chengdu, China
| | - Xiaoli Sun
- Department of Pharmacology, Mays Cancer Center, Transplant Center, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
| |
Collapse
|
10
|
Loomba R, Friedman SL, Shulman GI. Mechanisms and disease consequences of nonalcoholic fatty liver disease. Cell 2021; 184:2537-2564. [PMID: 33989548 DOI: 10.1016/j.cell.2021.04.015] [Citation(s) in RCA: 821] [Impact Index Per Article: 273.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 03/21/2021] [Accepted: 04/09/2021] [Indexed: 02/07/2023]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is the leading chronic liver disease worldwide. Its more advanced subtype, nonalcoholic steatohepatitis (NASH), connotes progressive liver injury that can lead to cirrhosis and hepatocellular carcinoma. Here we provide an in-depth discussion of the underlying pathogenetic mechanisms that lead to progressive liver injury, including the metabolic origins of NAFLD, the effect of NAFLD on hepatic glucose and lipid metabolism, bile acid toxicity, macrophage dysfunction, and hepatic stellate cell activation, and consider the role of genetic, epigenetic, and environmental factors that promote fibrosis progression and risk of hepatocellular carcinoma in NASH.
Collapse
Affiliation(s)
- Rohit Loomba
- NAFLD Research Center, Division of Gastroenterology, Department of Medicine, University of California at San Diego, La Jolla, CA 92093, USA.
| | - Scott L Friedman
- Division of Liver Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
| | - Gerald I Shulman
- Departments of Internal Medicine and Cellular & Molecular Physiology, Yale Diabetes Research Center, Yale School of Medicine, New Haven, CT 06520, USA.
| |
Collapse
|
11
|
Wang Y, Xu G, Wang Z, Li R, Zhan X, Liu H, Qin Q, Li W, Wang X, Zhang M, Tang J, Bai Z, Xiao X. Psoralidin, a major component of Psoraleae Fructus, induces inflammasome activation and idiosyncratic liver injury. Int Immunopharmacol 2021; 92:107352. [PMID: 33422760 DOI: 10.1016/j.intimp.2020.107352] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 12/24/2020] [Accepted: 12/26/2020] [Indexed: 12/12/2022]
Abstract
Idiosyncratic drug-induced liver injury (IDILI) is a rare but potentially fatal disease that is unpredictable and independent of the dose of the drug. Increasing evidence suggests that the majority of IDILI cases are immune-mediated, and the aberrant activation of inflammasome plays a vital role in progression. Psoraleae Fructus (PF), a tonic Chinese medicine, has been able to cause IDILI, but the precise mechanism of hepatotoxicity remains unclear. In this study, eight bioactive compounds involved in PF-induced inflammasome activation were investigated. The results demonstrated that psoralidin activated the inflammasomes followed by secreting caspase-1 and interleukin 1β (IL-1β) in a dose-dependent manner. Interestingly, MCC950, a potent inhibitor of the NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome, could not entirely suppress the psoralidin-induced inflammasome activation. Moreover, psoralidin significantly induced IL-1β maturation and caspase-1 activation in NLRP3-knockout bone marrow-derived macrophages (BMDMs), suggesting that psoralidin not only activates the NLRP3 inflammasome but also activates other types of inflammasomes. The results also demonstrated that psoralidin activated the inflammasomes by promoting the C-terminal caspase recruitment domain (ASC) oligomerization, and the production of mitochondrial reactive oxygen species (mtROS) is a decisive factor in psoralidin-induced inflammasome activation. Importantly, in vivo data revealed that psoralidin induced hepatic inflammation, increased aminotransferase activity and increased the production of IL-1β and tumor necrosis factor(TNF-α) in a susceptible mouse model of lipopolysaccharide (LPS)-mediated IDILI. In summary, these results confirmed that psoralidin causes IDILI by inducing inflammasome activation. The study suggests that psoralidin is a possible risk factor and is responsible for PF-induced IDILI.
Collapse
Affiliation(s)
- Yan Wang
- School of Pharmacy, Henan University of Chinese Medicine, Zhengzhou 450046, China; China Military Institute of Chinese Materia, The Fifth Medical Centre, Chinese PLA General Hospital, Beijing 100039, China
| | - Guang Xu
- China Military Institute of Chinese Materia, The Fifth Medical Centre, Chinese PLA General Hospital, Beijing 100039, China
| | - Zhilei Wang
- China Military Institute of Chinese Materia, The Fifth Medical Centre, Chinese PLA General Hospital, Beijing 100039, China; School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China
| | - Ruisheng Li
- Research Center for Clinical and Translational Medicine, The Fifth Medical Centre, Chinese PLA General Hospital, Beijing 100500, China
| | - Xiaoyan Zhan
- China Military Institute of Chinese Materia, The Fifth Medical Centre, Chinese PLA General Hospital, Beijing 100039, China; Integrative Medical Center, The Fifth Medical Centre, Chinese PLA General Hospital, Beijing 100039, China
| | - Hongbin Liu
- China Military Institute of Chinese Materia, The Fifth Medical Centre, Chinese PLA General Hospital, Beijing 100039, China; School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China
| | - Qin Qin
- China Military Institute of Chinese Materia, The Fifth Medical Centre, Chinese PLA General Hospital, Beijing 100039, China
| | - Weixia Li
- Department of Pharmacy, The First Affiliated Hospital of Henan University of Chinese Medicine, Zhengzhou 450000, China
| | - Xiaoyan Wang
- Department of Pharmacy, The First Affiliated Hospital of Henan University of Chinese Medicine, Zhengzhou 450000, China
| | - Mingliang Zhang
- Department of Pharmacy, The First Affiliated Hospital of Henan University of Chinese Medicine, Zhengzhou 450000, China
| | - Jinfa Tang
- Department of Pharmacy, The First Affiliated Hospital of Henan University of Chinese Medicine, Zhengzhou 450000, China.
| | - Zhaofang Bai
- China Military Institute of Chinese Materia, The Fifth Medical Centre, Chinese PLA General Hospital, Beijing 100039, China; Integrative Medical Center, The Fifth Medical Centre, Chinese PLA General Hospital, Beijing 100039, China.
| | - Xiaohe Xiao
- China Military Institute of Chinese Materia, The Fifth Medical Centre, Chinese PLA General Hospital, Beijing 100039, China; Integrative Medical Center, The Fifth Medical Centre, Chinese PLA General Hospital, Beijing 100039, China.
| |
Collapse
|
12
|
Li F, Zhao C, Shao T, Liu Y, Gu Z, Jiang M, Li H, Zhang L, Gillevet PM, Puri P, Deng ZB, Chen SY, Barve S, Gobejishvili L, Vatsalya V, McClain CJ, Feng W. Cathelicidin-related antimicrobial peptide alleviates alcoholic liver disease through inhibiting inflammasome activation. J Pathol 2020; 252:371-383. [PMID: 33245573 DOI: 10.1002/path.5531] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Revised: 07/05/2020] [Accepted: 08/06/2020] [Indexed: 02/06/2023]
Abstract
Alcoholic liver disease (ALD) is associated with gut dysbiosis and hepatic inflammasome activation. While it is known that antimicrobial peptides (AMPs) play a critical role in the regulation of bacterial homeostasis in ALD, the functional role of AMPs in the alcohol-induced inflammasome activation is unclear. The aim of this study was to determine the effects of cathelicidin-related antimicrobial peptide (CRAMP) on inflammasome activation in ALD. CRAMP knockout (Camp-/-) and wild-type (WT) mice were subjected to binge-on-chronic alcohol feeding and synthetic CRAMP peptide was administered. Serum/plasma and hepatic tissue samples from human subjects with alcohol use disorder and/or alcoholic hepatitis were analyzed. CRAMP deficiency exacerbated ALD with enhanced inflammasome activation as shown by elevated serum interleukin (IL)-1β levels. Although Camp-/- mice had comparable serum endotoxin levels compared to WT mice after alcohol feeding, hepatic lipopolysaccharide (LPS) binding protein (LBP) and cluster of differentiation (CD) 14 were increased. Serum levels of uric acid (UA), a Signal 2 molecule in inflammasome activation, were positively correlated with serum levels of IL-1β in alcohol use disorder patients with ALD and were increased in Camp-/- mice fed alcohol. In vitro studies showed that CRAMP peptide inhibited LPS binding to macrophages and inflammasome activation stimulated by a combination of LPS and UA. Synthetic CRAMP peptide administration decreased serum UA and IL-1β concentrations and rescued the liver from alcohol-induced damage in both WT and Camp-/- mice. In summary, CRAMP exhibited a protective role against binge-on-chronic alcohol-induced liver damage via regulation of inflammasome activation by decreasing LPS binding and UA production. CRAMP administration may represent a novel strategy for treating ALD. © 2020 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Collapse
Affiliation(s)
- Fengyuan Li
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY, USA.,Department of Medicine, University of Louisville, Louisville, KY, USA
| | - Cuiqing Zhao
- Department of Medicine, University of Louisville, Louisville, KY, USA.,College of Animal Science and Technology, Key Lab of Preventive Veterinary Medicine in Jilin Province, Jilin Agricultural Science and Technology University, Jilin, PR China
| | - Tuo Shao
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY, USA.,Department of Medicine, University of Louisville, Louisville, KY, USA
| | - Yunhuan Liu
- Department of Medicine, University of Louisville, Louisville, KY, USA
| | - Zelin Gu
- Department of Medicine, University of Louisville, Louisville, KY, USA
| | - Mengwei Jiang
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY, USA.,Department of Medicine, University of Louisville, Louisville, KY, USA
| | - Huimin Li
- Department of Medicine, University of Louisville, Louisville, KY, USA.,School of Pharmaceutical Sciences, Jiujiang University, Jiujiang, PR China
| | - Lihua Zhang
- Department of Medicine, University of Louisville, Louisville, KY, USA
| | | | - Puneet Puri
- Section of Gastroenterology, Hepatology and Nutrition, Virginia Commonwealth University, Richmond, VA, USA.,McGuire VA Medical Center, Richmond, VA, USA
| | - Zhong-Bin Deng
- Department of Medicine, University of Louisville, Louisville, KY, USA.,Alcohol Research Center, University of Louisville, Louisville, KY, USA.,Hepatobiology & Toxicology Center, University of Louisville, Louisville, KY, USA
| | - Shao-Yu Chen
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY, USA.,Alcohol Research Center, University of Louisville, Louisville, KY, USA
| | - Shirish Barve
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY, USA.,Department of Medicine, University of Louisville, Louisville, KY, USA.,Alcohol Research Center, University of Louisville, Louisville, KY, USA.,Hepatobiology & Toxicology Center, University of Louisville, Louisville, KY, USA
| | - Leila Gobejishvili
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY, USA.,Department of Medicine, University of Louisville, Louisville, KY, USA.,Alcohol Research Center, University of Louisville, Louisville, KY, USA.,Hepatobiology & Toxicology Center, University of Louisville, Louisville, KY, USA
| | - Vatsalya Vatsalya
- Department of Medicine, University of Louisville, Louisville, KY, USA.,Alcohol Research Center, University of Louisville, Louisville, KY, USA.,Hepatobiology & Toxicology Center, University of Louisville, Louisville, KY, USA
| | - Craig J McClain
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY, USA.,Department of Medicine, University of Louisville, Louisville, KY, USA.,Alcohol Research Center, University of Louisville, Louisville, KY, USA.,Hepatobiology & Toxicology Center, University of Louisville, Louisville, KY, USA.,Robley Rex VA Medical Center, Louisville, KY, USA
| | - Wenke Feng
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY, USA.,Department of Medicine, University of Louisville, Louisville, KY, USA.,Alcohol Research Center, University of Louisville, Louisville, KY, USA.,Hepatobiology & Toxicology Center, University of Louisville, Louisville, KY, USA
| |
Collapse
|
13
|
Idalsoaga F, Kulkarni AV, Mousa OY, Arrese M, Arab JP. Non-alcoholic Fatty Liver Disease and Alcohol-Related Liver Disease: Two Intertwined Entities. Front Med (Lausanne) 2020; 7:448. [PMID: 32974366 PMCID: PMC7468507 DOI: 10.3389/fmed.2020.00448] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 07/06/2020] [Indexed: 12/12/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide, with a prevalence of 25-30%. Since its first description in 1980, NAFLD has been conceived as a different entity from alcohol-related fatty liver disease (ALD), despite that, both diseases have an overlap in the pathophysiology, share genetic-epigenetic factors, and frequently coexist. Both entities are characterized by a broad spectrum of histological features ranging from isolated steatosis to steatohepatitis and cirrhosis. Distinction between NAFLD and ALD is based on the amount of consumed alcohol, which has been arbitrarily established. In this context, a proposal of positive criteria for NAFLD diagnosis not considering exclusion of alcohol consumption as a prerequisite criterion for diagnosis had emerged, recognizing the possibility of a dual etiology of fatty liver in some individuals. The impact of moderate alcohol use on the severity of NAFLD is ill-defined. Some studies suggest protective effects in moderate doses, but current evidence shows that there is no safe threshold for alcohol consumption for NAFLD. In fact, given the synergistic effect between alcohol consumption, obesity, and metabolic dysfunction, it is likely that alcohol use serves as a significant risk factor for the progression of liver disease in NAFLD and metabolic syndrome. This also affects the incidence of hepatocellular carcinoma. In this review, we summarize the overlapping pathophysiology of NAFLD and ALD, the current data on alcohol consumption in patients with NAFLD, and the effects of metabolic dysfunction and overweight in ALD.
Collapse
Affiliation(s)
- Francisco Idalsoaga
- Departamento de Gastroenterología, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Anand V Kulkarni
- Department of Hepatology, Asian Institute of Gastroenterology, Hyderabad, India
| | - Omar Y Mousa
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN, United States.,Division of Gastroenterology and Hepatology, Mayo Clinic Health System, Mankato, MN, United States
| | - Marco Arrese
- Departamento de Gastroenterología, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Envejecimiento y Regeneración (CARE), Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Juan Pablo Arab
- Departamento de Gastroenterología, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Envejecimiento y Regeneración (CARE), Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| |
Collapse
|
14
|
Baeza-Raja B, Goodyear A, Liu X, Lam K, Yamamoto L, Li Y, Dodson GS, Takeuchi T, Kisseleva T, Brenner DA, Dabbagh K. Pharmacological inhibition of P2RX7 ameliorates liver injury by reducing inflammation and fibrosis. PLoS One 2020; 15:e0234038. [PMID: 32492075 PMCID: PMC7269334 DOI: 10.1371/journal.pone.0234038] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 05/04/2020] [Indexed: 12/13/2022] Open
Abstract
Extracellular adenosine triphosphate (eATP) released by damaged cells, and its purinergic receptors, comprise a crucial signaling network after injury. Purinergic receptor P2X7 (P2RX7), a major driver of NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome activation and IL-1β processing, has been shown to play a role in liver injury in murine diet- and chemically-induced liver injury models. It is unclear, however, whether P2RX7 plays a role in non-alcoholic steatohepatitis (NASH) and which cell type is the main target of P2RX7 pharmacological inhibition. Here, we report that P2RX7 is expressed by infiltrating monocytes and resident Kupffer cells in livers from NASH-affected individuals. Using primary isolated human cells, we demonstrate that P2RX7 expression in CD14+ monocytes and Kupffer cells primarily mediates IL-1β release. In addition, we show that pharmacological inhibition of P2RX7 in monocytes and Kupffer cells, blocks IL-1β release, reducing hepatocyte caspase 3/7 activity, IL-1β-mediated CCL2 and CCL5 chemokine gene expression and secretion, and hepatic stellate cell (HSC) procollagen secretion. Consequently, in a chemically-induced nonhuman primate model of liver fibrosis, treatment with a P2RX7 inhibitor improved histological characteristics of NASH, protecting from liver inflammation and fibrosis. Taken together, these findings underscore the critical role of P2RX7 in the pathogenesis of NASH and implicate P2RX7 as a promising therapeutic target for the management of this disease.
Collapse
Affiliation(s)
- Bernat Baeza-Raja
- Second Genome Inc., South San Francisco, California, United States of America
| | - Andrew Goodyear
- Second Genome Inc., South San Francisco, California, United States of America
| | - Xiao Liu
- Department of Surgery, University of California San Diego, La Jolla, California, United States of America
| | - Kevin Lam
- Department of Surgery, University of California San Diego, La Jolla, California, United States of America
| | - Lynn Yamamoto
- Second Genome Inc., South San Francisco, California, United States of America
| | - Yingwu Li
- Second Genome Inc., South San Francisco, California, United States of America
| | - G. Steven Dodson
- Second Genome Inc., South San Francisco, California, United States of America
| | - Toshi Takeuchi
- Second Genome Inc., South San Francisco, California, United States of America
| | - Tatiana Kisseleva
- Department of Surgery, University of California San Diego, La Jolla, California, United States of America
| | - David A. Brenner
- Department of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Karim Dabbagh
- Second Genome Inc., South San Francisco, California, United States of America
| |
Collapse
|
15
|
Cellular Interplay as a Consequence of Inflammatory Signals Leading to Liver Fibrosis Development. Cells 2020; 9:cells9020461. [PMID: 32085494 PMCID: PMC7072785 DOI: 10.3390/cells9020461] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 02/10/2020] [Accepted: 02/15/2020] [Indexed: 02/06/2023] Open
Abstract
Inflammation has been known to be an important driver of fibrogenesis in the liver and onset of hepatic fibrosis. It starts off as a process meant to protect the liver from further damage, but it can become the main promoter of liver fibrosis. There are many inflammation-related pathways activated during liver fibrosis that lead to hepatic stellate cells (HSCs) activation and collagen-deposition in the liver. Such events are mostly modulated upstream of HSCs and involve signals from hepatocytes and innate immune cells. One particular event is represented by cell death during liver injury that generates multiple inflammatory signals that further trigger sterile inflammation and enhancement of inflammatory response. The assembly of inflammasome that responds to danger-associated molecular patterns (DAMPs) stimulates the release of pro-inflammatory cytokines and at the same time, initiates programmed cell death called pyroptosis. This review focuses on cellular and molecular mechanisms responsible for initiation and progress of inflammation in the liver.
Collapse
|
16
|
Møhlenberg M, Terczynska-Dyla E, Thomsen KL, George J, Eslam M, Grønbæk H, Hartmann R. The role of IFN in the development of NAFLD and NASH. Cytokine 2019; 124:154519. [DOI: 10.1016/j.cyto.2018.08.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 08/10/2018] [Accepted: 08/11/2018] [Indexed: 02/07/2023]
|
17
|
Sanchez-Alavez M, Nguyen W, Mori S, Wills DN, Otero D, Aguirre CA, Singh M, Ehlers CL, Conti B. Time Course of Blood and Brain Cytokine/Chemokine Levels Following Adolescent Alcohol Exposure and Withdrawal in Rats. Alcohol Clin Exp Res 2019; 43:2547-2558. [PMID: 31589333 PMCID: PMC6904424 DOI: 10.1111/acer.14209] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 10/01/2019] [Indexed: 12/28/2022]
Abstract
BACKGROUND Adolescence is a critical period for neural development, and alcohol exposure during adolescence can lead to an elevated risk for health consequences as well as alcohol use disorders. Clinical and experimental data suggest that chronic alcohol exposure may produce immunomodulatory effects that can lead to the activation of pro-inflammatory cytokine pathways as well as microglial markers. The present study evaluated, in brain and blood, the effects of adolescent alcohol exposure and withdrawal on microglia and on the most representative pro- and anti-inflammatory cytokines and major chemokines that can contribute to the establishing of a neuroinflammatory environment. METHODS Wistar rats (males, n = 96) were exposed to ethanol (EtOH) vapors, or air control, for 5 weeks over adolescence (PD22-PD58). Brains and blood samples were collected at 3 time points: (i) after 35 days of vapor/air exposure (PD58); (ii) after 1 day of withdrawal (PD59), and (iii) 28 days after withdrawal (PD86). The ionized calcium-binding adapter molecule 1 (Iba-1) was used to index microglial activation, and cytokine/chemokine responses were analyzed using magnetic bead panels. RESULTS After 35 days of adolescent vapor exposure, a significant increase in Iba-1 immunoreactivity was seen in amygdala, frontal cortex, hippocampus, and substantia nigra. However, Iba-1 density returned to control levels at both 1 day and 28 days of withdrawal except in the hippocampus where Iba-1 density was significantly lower than controls. In serum, adolescent EtOH exposure induced a reduction in IL-13 and an increase in fractalkine at day 35. After 1 day of withdrawal, IL-18 was reduced, and IP-10 was elevated, whereas both IP-10 and IL-10 were elevated at 28 days following withdrawal. In the frontal cortex, adolescent EtOH exposure induced an increase in IL-1β at day 35, and 28 days of withdrawal, and IL-10 was increased after 28 days of withdrawal. CONCLUSION These data demonstrate that EtOH exposure during adolescence produces significant microglial activation; however, inflammatory markers seen in the blood appear to differ from those observed in the brain.
Collapse
Affiliation(s)
| | - William Nguyen
- Department of Neuroscience, The Scripps Research Institute, La Jolla, California
| | - Simone Mori
- Department of Neuroscience, The Scripps Research Institute, La Jolla, California
| | - Derek N Wills
- Department of Neuroscience, The Scripps Research Institute, La Jolla, California
| | - Dennis Otero
- Infectious and Inflammatory Disease Center and National Cancer Institute (NCI)-Designated Cancer Center, Sanford Burnham Prebys Medical Discovery Research Institute, La Jolla, California
| | - Carlos A Aguirre
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California
| | - Mona Singh
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California
| | - Cindy L Ehlers
- Department of Neuroscience, The Scripps Research Institute, La Jolla, California
| | - Bruno Conti
- Department of Neuroscience, The Scripps Research Institute, La Jolla, California
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California
- Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, California
| |
Collapse
|
18
|
Sanchez-Alavez M, Nguyen W, Mori S, Wills DN, Otero D, Ehlers CL, Conti B. Time course of microglia activation and brain and blood cytokine/chemokine levels following chronic ethanol exposure and protracted withdrawal in rats. Alcohol 2019; 76:37-45. [PMID: 30554034 DOI: 10.1016/j.alcohol.2018.07.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 05/30/2018] [Accepted: 07/11/2018] [Indexed: 12/12/2022]
Abstract
Alcohol produces complex effects on the immune system. Moderate alcohol use (1-2 drinks per day) has been shown to produce anti-inflammatory responses in human blood monocytes, whereas, the post mortem brains of severe alcoholics show increased immune gene expression and activated microglial markers. The present study was conducted to evaluate the time course of alcohol effects during exposure and after withdrawal, and to determine the relationship between microglial and cytokine responses in brain and blood. Forty-eight adult, male Wistar rats were exposed to chronic ethanol vapors, or air control, for 5 weeks. Following ethanol/air exposure blood and brains were collected at three time points: 1) while intoxicated, following 35 days of air/vapor exposure; 2) following 24 h of withdrawal from exposure, and 3) 28 days after withdrawal. One hemisphere of the brain was flash-frozen for cytokine analysis, and the other was fixed for immunohistochemical analysis. The ionized calcium-binding adapter molecule 1 (Iba-1) was used to evaluate microglia activation at the three time points, and rat cytokine/chemokine Magnetic Bead Panels (Millipore) were used to analyze frontal cortex tissue lysate and serum. Ethanol induced a significant increase in Iba-1 that peaked at day 35, remained significant after 1 day of withdrawal, and was elevated at day 28 in frontal cortex, amygdala, and substantia nigra. Ethanol exposure was associated with a transient reduction of the serum level of the major pro- and anti-inflammatory cytokines and chemokines and a transient increase of effectors of sterile inflammation. Little or no changes in these molecules were seen in the frontal cortex except for HMG1 and fractalkine that were reduced and elevated, respectively, at day 28 following withdrawal. These data show that ethanol exposure produces robust microglial activation; however, measures of inflammation in the blood differ from those in the brain over a protracted time course.
Collapse
Affiliation(s)
- Manuel Sanchez-Alavez
- Department of Neuroscience, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, United States
| | - William Nguyen
- Department of Neuroscience, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, United States
| | - Simone Mori
- Department of Neuroscience, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, United States
| | - Derek N Wills
- Department of Neuroscience, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, United States
| | - Dennis Otero
- Infectious and Inflammatory Disease Center and National Cancer Institute (NCI)-Designated Cancer Center, Sanford Burnham Prebys Medical Discovery Research Institute, La Jolla, CA 92037, United States
| | - Cindy L Ehlers
- Department of Neuroscience, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, United States.
| | - Bruno Conti
- Department of Neuroscience, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, United States; Department of Molecular Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, United States; Dorris Neuroscience Center, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, United States
| |
Collapse
|
19
|
Ioannou GN, Landis CS, Jin GY, Haigh WG, Farrell GC, Kuver R, Lee SP, Savard C. Cholesterol Crystals in Hepatocyte Lipid Droplets Are Strongly Associated With Human Nonalcoholic Steatohepatitis. Hepatol Commun 2019; 3:776-791. [PMID: 31168512 PMCID: PMC6545865 DOI: 10.1002/hep4.1348] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 03/04/2019] [Indexed: 12/19/2022] Open
Abstract
It is unclear what drives the development of fibrosing nonalcoholic steatohepatitis (NASH). We aimed to determine whether cholesterol crystallization within hepatocyte lipid droplets (LDs) distinguishes patients with fibrosing NASH from patients with isolated hepatic steatosis and to study pathways leading to cholesterol accumulation in hepatocyte LDs. Patients with fibrosing NASH (n = 16) were compared to patients with isolated steatosis (n = 14). Almost all patients with fibrosing NASH had free cholesterol staining by filipin (16/16) and cholesterol crystals (15/16) in hepatocyte LDs, mostly in association with the LD membrane, compared to only 3/14 with cholesterol crystals and 3/14 with faint filipin staining in patients with isolated steatosis (P < 0.05). We were unable to identify significant differences in the expression of genes in liver tissue related to cholesterol homeostasis or LD proteins between patients with fibrosing NASH and isolated steatosis. Human hepatoma cell line (HepG2) cells were supplemented with low-density lipoprotein (LDL)-cholesterol and oleic acid to develop large LDs, similar to those observed in patients with NASH. Fluorescent markers were used to track the uptake and intracellular trafficking of LDL-cholesterol. LDL-cholesterol was taken up by HepG2 cells and transported through the endosomal-lysosomal compartment directly to LDs, suggesting direct contact sites between late endosomes and LDs. Exposure of HepG2 cells to LDL-cholesterol resulted in a high concentration of cholesterol and cholesterol crystallization in LDs. Conclusion: Excess cholesterol is stored in the liver primarily within hepatocyte LDs where it can crystallize. Our findings are best explained by direct transport of cholesterol from late endosomes/lysosomes to LDs in hepatocytes. We found a strong association between the presence of LD cholesterol crystals and the development of fibrosing NASH in humans, suggesting a causal relationship.
Collapse
Affiliation(s)
- George N Ioannou
- Division of Gastroenterology, Department of Medicine Veterans Affairs Puget Sound Health Care System Seattle WA.,Division of Gastroenterology, Department of Medicine University of Washington Seattle WA.,Research and Development Veterans Affairs Puget Sound Health Care System Seattle WA
| | - Charles S Landis
- Division of Gastroenterology, Department of Medicine University of Washington Seattle WA
| | - Ga-Young Jin
- Research and Development Veterans Affairs Puget Sound Health Care System Seattle WA
| | - W Geoffrey Haigh
- Research and Development Veterans Affairs Puget Sound Health Care System Seattle WA
| | - Geoffrey C Farrell
- Liver Research Group Australian National University Medical School at the Canberra Hospital Garran Australia
| | - Rahul Kuver
- Division of Gastroenterology, Department of Medicine University of Washington Seattle WA
| | - Sum P Lee
- Division of Gastroenterology, Department of Medicine University of Washington Seattle WA
| | - Christopher Savard
- Division of Gastroenterology, Department of Medicine Veterans Affairs Puget Sound Health Care System Seattle WA.,Division of Gastroenterology, Department of Medicine University of Washington Seattle WA.,Research and Development Veterans Affairs Puget Sound Health Care System Seattle WA
| |
Collapse
|
20
|
The role of hepatic macrophages in nonalcoholic fatty liver disease and nonalcoholic steatohepatitis. Lab Anim Res 2018; 34:133-139. [PMID: 30671098 PMCID: PMC6333604 DOI: 10.5625/lar.2018.34.4.133] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 09/28/2018] [Accepted: 10/01/2018] [Indexed: 12/18/2022] Open
Abstract
Nonalcoholic steatohepatitis (NASH) is becoming common chronic liver disease because of the increasing global prevalence of obesity and consequently Nonalcoholic fatty liver disease (NAFLD). However, the mechanism for progression of NAFLD to NASH and then cirrhosis is not completely understood, yet. The triggering of these hepatic diseases is thought from hepatocyte injury caused by over-accumulated lipid toxicity. Injured hepatocytes release damage-associated molecular patterns (DAMPs), which can stimulate the Kupffer cells (KCs), liver-resident macrophages, to release pro-inflammatory cytokines and chemokines, and recruit monocyte-derived macrophages (MDMs). The increased activation of KCs and recruitment of MDMs accelerate the progression of NAFLD to NASH and cirrhosis. Therefore, characterization for activation of hepatic macrophages, both KCs and MDMs, is a baseline to figure out the progression of hepatic diseases. The purpose of this review is to discuss the current understanding of mechanisms of NAFLD and NASH, mainly focusing on characterization and function of hepatic macrophages and suggests the regulators of hepatic macrophages as the therapeutic target in hepatic diseases.
Collapse
|
21
|
Adak M, Das D, Niyogi S, Nagalakshmi C, Ray D, Chakrabarti P. Inflammasome activation in Kupffer cells confers a protective response in nonalcoholic steatohepatitis through pigment epithelium-derived factor expression. FASEB J 2018; 32:fj201800190. [PMID: 29897812 DOI: 10.1096/fj.201800190] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
Hepatocellular death or ballooning distinguishes the transition of simple steatosis to irreversible nonalcoholic steatohepatitis (NASH). However, the molecular mechanism of hepatocellular apoptosis in NASH is largely unclear, and discovery of endogenous mediators that could prevent or inhibit cell death is thereby critical in intercepting NASH progression. Here, we identified pigment epithelium-derived factor (PEDF), a secreted, moonlighting hepatokine as 1 hepatoprotective agent in mice with diet-induced NASH. Hepatic PEDF expression is induced by IL-1β, which is derived from inflammasome activation in liver-resident Kupffer cells, an effect that is negatively regulated by TNF-α and predominantly secreted by monocyte-derived, recruited, hepatic macrophages. Mechanistically, reciprocal and opposing roles for IL-1β and TNF-α in PEDF expression are mediated by differential activation of NF-κB. Although augmented TNF-α production leads to temporal reduction of PEDF expression in NASH, PEDF conversely abrogates TNF-α-mediated hepatocyte death by modulating the extrinsic apoptosis pathway. Thus, our study highlights PEDF as a functionally important hepatokine in NASH progression by linking inflammasome activation and hepatocellular death.-Adak, M., Das, D., Niyogi, S., Nagalakshmi, C., Ray, D., Chakrabarti, P. Inflammasome activation in Kupffer cells confers a protective response in nonalcoholic steatohepatitis through pigment epithelium-derived factor expression.
Collapse
Affiliation(s)
- Moumita Adak
- Division of Cell Biology and Physiology, Council of Scientific and Industrial Research (CSIR), Indian Institute of Chemical Biology, Kolkata, India
| | - Debajyoti Das
- Division of Cell Biology and Physiology, Council of Scientific and Industrial Research (CSIR), Indian Institute of Chemical Biology, Kolkata, India
| | - Sougata Niyogi
- Division of Cell Biology and Physiology, Council of Scientific and Industrial Research (CSIR), Indian Institute of Chemical Biology, Kolkata, India
| | - Challa Nagalakshmi
- National Institute of Pharmaceutical Education and Research, Kolkata, India
| | - Dipika Ray
- Division of Cell Biology and Physiology, Council of Scientific and Industrial Research (CSIR), Indian Institute of Chemical Biology, Kolkata, India
| | - Partha Chakrabarti
- Division of Cell Biology and Physiology, Council of Scientific and Industrial Research (CSIR), Indian Institute of Chemical Biology, Kolkata, India
| |
Collapse
|
22
|
Marra F, Svegliati-Baroni G. Lipotoxicity and the gut-liver axis in NASH pathogenesis. J Hepatol 2018; 68:280-295. [PMID: 29154964 DOI: 10.1016/j.jhep.2017.11.014] [Citation(s) in RCA: 518] [Impact Index Per Article: 86.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2017] [Revised: 11/05/2017] [Accepted: 11/09/2017] [Indexed: 12/12/2022]
Abstract
The pathogenesis of non-alcoholic fatty liver disease, particularly the mechanisms whereby a minority of patients develop a more severe phenotype characterised by hepatocellular damage, inflammation, and fibrosis is still incompletely understood. Herein, we discuss two pivotal aspects of the pathogenesis of NASH. We first analyse the initial mechanisms responsible for hepatocellular damage and inflammation, which derive from the toxic effects of excess lipids. Accumulating data indicate that the total amount of triglycerides stored in hepatocytes is not the major determinant of lipotoxicity, and that specific lipid classes act as damaging agents on liver cells. In particular, the role of free fatty acids such as palmitic acid, cholesterol, lysophosphatidylcholine and ceramides has recently emerged. These lipotoxic agents affect the cell behaviour via multiple mechanisms, including activation of signalling cascades and death receptors, endoplasmic reticulum stress, modification of mitochondrial function, and oxidative stress. In the second part of this review, the cellular and molecular players involved in the cross-talk between the gut and the liver are considered. These include modifications to the microbiota, which provide signals through the intestine and bacterial products, as well as hormones produced in the bowel that affect metabolism at different levels including the liver. Finally, the activation of nuclear receptors by bile acids is analysed.
Collapse
Affiliation(s)
- Fabio Marra
- Dipartimento di Medicina Sperimentale e Clinica and Centro di Ricerca Denothe, Università di Firenze, Italy.
| | - Gianluca Svegliati-Baroni
- Dipartimento Scienze Cliniche e Molecolari, Università Politecnica delle Marche, Ancona, Italy; Centro Interdipartimentale Obesità, Università Politecnica delle Marche, Ancona, Italy
| |
Collapse
|
23
|
Greuter T, Malhi H, Gores GJ, Shah VH. Therapeutic opportunities for alcoholic steatohepatitis and nonalcoholic steatohepatitis: exploiting similarities and differences in pathogenesis. JCI Insight 2017; 2:95354. [PMID: 28878132 DOI: 10.1172/jci.insight.95354] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Alcoholic steatohepatitis (ASH) and nonalcoholic steatohepatitis (NASH) are among the most frequent causes of chronic liver disease in the United States. Although the two entities are triggered by different etiologies - chronic alcohol consumption (ASH) and obesity-associated lipotoxicity (NASH) - they share overlapping histological and clinical features owing to common pathogenic mechanisms. These pathogenic processes include altered hepatocyte lipid metabolism, organelle dysfunction (i.e., ER stress), hepatocyte apoptosis, innate immune system activation, and hepatic stellate cell activation. Nonetheless, there are several disease-specific molecular signaling pathways, such as differential pathway activation downstream of TLR4 (MyD88-dependence in NASH versus MyD88-independence in ASH), inflammasome activation and IL-1β signaling in ASH, insulin resistance and lipotoxicity in NASH, and dysregulation of different microRNAs, which clearly highlight that ASH and NASH are two distinct biological entities. Both pathogenic similarities and differences have therapeutic implications. In this Review, we discuss these pathogenic mechanisms and their therapeutic implications for each disease, focusing on both shared and distinct targets.
Collapse
Affiliation(s)
- Thomas Greuter
- Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland.,Gastroenterology Research Unit, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA
| | - Harmeet Malhi
- Gastroenterology Research Unit, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA
| | - Gregory J Gores
- Gastroenterology Research Unit, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA
| | - Vijay H Shah
- Gastroenterology Research Unit, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA
| |
Collapse
|
24
|
Iracheta-Vellve A, Petrasek J, Gyogyosi B, Bala S, Csak T, Kodys K, Szabo G. Interleukin-1 inhibition facilitates recovery from liver injury and promotes regeneration of hepatocytes in alcoholic hepatitis in mice. Liver Int 2017; 37:968-973. [PMID: 28345165 PMCID: PMC5479767 DOI: 10.1111/liv.13430] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 03/13/2017] [Indexed: 12/13/2022]
Abstract
BACKGROUND & AIMS Inflammation and impaired hepatocyte regeneration contribute to liver failure in alcoholic hepatitis (AH). Interleukin (IL)-1 is a key inflammatory cytokine in the pathobiology of AH. The role of IL-1 in liver regeneration in the recovery phase of alcohol-induced liver injury is unknown. METHODS In this study, we tested IL-1 receptor antagonist to block IL-1 signalling in a mouse model of acute-on-chronic liver injury on liver inflammation and hepatocyte regeneration in AH. RESULTS We observed that inhibition of IL-1 signalling decreased liver inflammation and neutrophil infiltration, and resulted in enhanced regeneration of hepatocytes and increased rate of recovery from liver injury in AH. CONCLUSION Our novel findings suggest that IL-1 drives sustained liver inflammation and impaired hepatocyte regeneration even after cessation of ethanol exposure.
Collapse
Affiliation(s)
- Arvin Iracheta-Vellve
- Department of Medicine, University of Massachusetts Medical School, Department of Medicine, LRB 215, 364 Plantation Street, Worcester, MA 01605, USA
| | - Jan Petrasek
- Department of Medicine, University of Massachusetts Medical School, Department of Medicine, LRB 215, 364 Plantation Street, Worcester, MA 01605, USA,Department of Medicine, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390
| | - Benedek Gyogyosi
- Department of Medicine, University of Massachusetts Medical School, Department of Medicine, LRB 215, 364 Plantation Street, Worcester, MA 01605, USA
| | - Shashi Bala
- Department of Medicine, University of Massachusetts Medical School, Department of Medicine, LRB 215, 364 Plantation Street, Worcester, MA 01605, USA
| | - Timea Csak
- Department of Medicine, University of Massachusetts Medical School, Department of Medicine, LRB 215, 364 Plantation Street, Worcester, MA 01605, USA
| | - Karen Kodys
- Department of Medicine, University of Massachusetts Medical School, Department of Medicine, LRB 215, 364 Plantation Street, Worcester, MA 01605, USA
| | - Gyongyi Szabo
- Department of Medicine, University of Massachusetts Medical School, Department of Medicine, LRB 215, 364 Plantation Street, Worcester, MA 01605, USA,Corresponding Author Information: Gyongyi Szabo, MD, PhD, Department of Medicine, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA, 01605, USA, Tel: 1-508-856-5276, Fax: 1-528-856-5033,
| |
Collapse
|
25
|
Andrographolide Ameliorates Inflammation and Fibrogenesis and Attenuates Inflammasome Activation in Experimental Non-Alcoholic Steatohepatitis. Sci Rep 2017; 7:3491. [PMID: 28615649 PMCID: PMC5471224 DOI: 10.1038/s41598-017-03675-z] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 05/04/2017] [Indexed: 12/13/2022] Open
Abstract
Therapy for nonalcoholic steatohepatitis (NASH) is limited. Andrographolide (ANDRO), a botanical compound, has a potent anti-inflammatory activity due to its ability to inhibit NF-κB. ANDRO has been also shown to inhibit the NLRP3 inflammasome, a relevant pathway in NASH. Our aim was to evaluate the effects of ANDRO in NASH and its influence on inflammasome activation in this setting. Thus, mice were fed a choline-deficient-amino-acid–defined (CDAA) diet with/without concomitant ANDRO administration (1 mg/kg, 3-times/week). Also, we assessed serum levels of alanine-aminotransferase (ALT), liver histology, hepatic triglyceride content (HTC) and hepatic expression of pro-inflammatory, pro-fibrotic and inflammasome genes. Inflammasome activation was also evaluated in fat-laden HepG2 cells. Our results showed that ANDRO administration decreased HTC and attenuated hepatic inflammation and fibrosis in CDAA-fed mice. ANDRO treatment determined a strong reduction in hepatic macrophage infiltration and reduced hepatic mRNA levels of both pro-inflammatory and pro-fibrotic genes. In addition, mice treated with ANDRO showed reduced expression of inflammasome genes. Finally, ANDRO inhibited LPS-induced interleukin-1β expression through NF-κB inhibition in fat-laden HepG2 cells and inflammasome disassembly. In conclusion, ANDRO administration reduces inflammation and fibrosis in experimental NASH. Inflammasome modulation by a NF-κB-dependent mechanism may be involved in the therapeutic effects of ANDRO.
Collapse
|
26
|
Abstract
PURPOSE OF REVIEW About 15-25% of patients with simple steatosis of non-alcoholic fatty liver disease progresses to non-alcoholic steatohepatitis (NASH), and the underlying mechanism for this progression has not been elucidated. NASH ultimately could progress to cirrhosis, an irreversible condition. RECENT FINDINGS Farnesoid X receptor (FXR) has been studied for its role in modulating inflammation, and the expression of FXR is down-regulated during NASH development. FXR deficiency has shown to progress and exacerbate NASH development, and FXR activation has been protective against liver inflammation associated with NASH. The expression of factors in both the adaptive and innate immune response in the liver are regulated in a FXR-dependent and -independent manner. SUMMARY Therefore, understanding key signaling pathways of liver inflammation in NASH is important to determine essential components that predispose, progress, or exacerbate NASH. FXR has been identified as a therapeutic target for NASH to prevent liver inflammation.
Collapse
|
27
|
Ioannou GN. The Role of Cholesterol in the Pathogenesis of NASH. Trends Endocrinol Metab 2016; 27:84-95. [PMID: 26703097 DOI: 10.1016/j.tem.2015.11.008] [Citation(s) in RCA: 325] [Impact Index Per Article: 40.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Revised: 11/12/2015] [Accepted: 11/16/2015] [Indexed: 01/01/2023]
Abstract
Lipotoxicity drives the development of progressive hepatic inflammation and fibrosis in a subgroup of patients with nonalcoholic fatty liver disease (NAFLD), causing nonalcoholic steatohepatitis (NASH) and even progression to cirrhosis and hepatocellular carcinoma (HCC). While the underlying molecular mechanisms responsible for the development of inflammation and fibrosis that characterize progressive NASH remain unclear, emerging evidence now suggests that hepatic free cholesterol (FC) is a major lipotoxic molecule critical in the development of experimental and human NASH. In this review, we examine the effects of excess FC in hepatocytes, Kupffer cells (KCs), and hepatic stellate cells (HSCs), and the subcellular mechanisms by which excess FC can induce cellular toxicity or proinflammatory and profibrotic effects in these cells.
Collapse
Affiliation(s)
- George N Ioannou
- Research and Development, Veterans Affairs Puget Sound Health Care System, Seattle, WA, USA; Division of Gastroenterology, Department of Medicine, Veterans Affairs Puget Sound Health Care System, Seattle, WA, USA; University of Washington, Seattle, WA, USA.
| |
Collapse
|