401
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Interleukin-1 Family Cytokines in Liver Diseases. Mediators Inflamm 2015; 2015:630265. [PMID: 26549942 PMCID: PMC4624893 DOI: 10.1155/2015/630265] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 09/27/2015] [Indexed: 02/06/2023] Open
Abstract
The gene encoding IL-1 was sequenced more than 30 years ago, and many related cytokines, such as IL-18, IL-33, IL-36, IL-37, IL-38, IL-1 receptor antagonist (IL-1Ra), and IL-36Ra, have since been identified. IL-1 is a potent proinflammatory cytokine and is involved in various inflammatory diseases. Other IL-1 family ligands are critical for the development of diverse diseases, including inflammatory and allergic diseases. Only IL-1Ra possesses the leader peptide required for secretion from cells, and many ligands require posttranslational processing for activation. Some require inflammasome-mediated processing for activation and release, whereas others serve as alarmins and are released following cell membrane rupture, for example, by pyroptosis or necroptosis. Thus, each ligand has the proper molecular process to exert its own biological functions. In this review, we will give a brief introduction to the IL-1 family cytokines and discuss their pivotal roles in the development of various liver diseases in association with immune responses. For example, an excess of IL-33 causes liver fibrosis in mice via activation and expansion of group 2 innate lymphoid cells to produce type 2 cytokines, resulting in cell conversion into pro-fibrotic M2 macrophages. Finally, we will discuss the importance of IL-1 family cytokine-mediated molecular and cellular networks in the development of acute and chronic liver diseases.
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402
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Filgueiras LR, Serezani CH, Jancar S. Leukotriene B4 as a Potential Therapeutic Target for the Treatment of Metabolic Disorders. Front Immunol 2015; 6:515. [PMID: 26500652 PMCID: PMC4597104 DOI: 10.3389/fimmu.2015.00515] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 09/22/2015] [Indexed: 12/31/2022] Open
Affiliation(s)
| | - C Henrique Serezani
- Department of Microbiology and Immunology, Indiana University School of Medicine , Indianapolis, IN , USA
| | - Sonia Jancar
- Department of Microbiology and Immunology, Indiana University School of Medicine , Indianapolis, IN , USA
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403
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Interactions between Myc and Mediators of Inflammation in Chronic Liver Diseases. Mediators Inflamm 2015; 2015:276850. [PMID: 26508814 PMCID: PMC4609837 DOI: 10.1155/2015/276850] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Accepted: 11/26/2014] [Indexed: 02/06/2023] Open
Abstract
Most chronic liver diseases (CLDs) are characterized by inflammatory processes with aberrant expressions of various pro- and anti-inflammatory mediators in the liver. These mediators are the driving force of many inflammatory liver disorders, which often result in fibrosis, cirrhosis, and liver tumorigenesis. c-Myc is involved in many cellular events such as cell growth, proliferation, and differentiation. c-Myc upregulates IL-8, IL-10, TNF-α, and TGF-β, while IL-1, IL-2, IL-4, TNF-α, and TGF-β promote c-Myc expression. Their interactions play a central role in fibrosis, cirrhosis, and liver cancer. Molecular interference of their interactions offers possible therapeutic potential for CLDs. In this review, current knowledge of the molecular interactions between c-Myc and various well known inflammatory mediators is discussed.
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404
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Affiliation(s)
- Irina A. Kirpich
- Division of Gastroenterology, Hepatology, and Nutrition, Department of MedicineUniversity of Louisville School of MedicineLouisvilleKY,Department of Pharmacology and ToxicologyUniversity of Louisville School of MedicineLouisvilleKY
| | - Dipendra Parajuli
- Division of Gastroenterology, Hepatology, and Nutrition, Department of MedicineUniversity of Louisville School of MedicineLouisvilleKY,Robley Rex Veterans Medical CenterLouisvilleKY
| | - Craig J. McClain
- Division of Gastroenterology, Hepatology, and Nutrition, Department of MedicineUniversity of Louisville School of MedicineLouisvilleKY,Department of Pharmacology and ToxicologyUniversity of Louisville School of MedicineLouisvilleKY,Robley Rex Veterans Medical CenterLouisvilleKY
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405
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Komohara Y, Fujiwara Y, Ohnishi K, Shiraishi D, Takeya M. Contribution of Macrophage Polarization to Metabolic Diseases. J Atheroscler Thromb 2015; 23:10-7. [PMID: 26412584 DOI: 10.5551/jat.32359] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Macrophage activation is one of the major immunological events in the pathogenesis of various diseases. Recent studies have disclosed that complicated mechanisms are involved in macrophage activation and polarization, and many published research articles have been based on the M1/M2 polarization concept. It is considered that M1- and M2-like macrophages are associated with T helper (Th)1-type and Th2-type immune responses, respectively, via several immune mediators. In this article, we summarize the correlations between macrophage polarization and metabolic disorders in both humans and mice and discuss the contribution of macrophage polarization to the pathogenic process of metabolic diseases.
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Affiliation(s)
- Yoshihiro Komohara
- Department of Cell Pathology, Graduate School of Medical Sciences, Kumamoto University
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406
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The Crosstalk between Hypoxia and Innate Immunity in the Development of Obesity-Related Nonalcoholic Fatty Liver Disease. BIOMED RESEARCH INTERNATIONAL 2015; 2015:319745. [PMID: 26491664 PMCID: PMC4600870 DOI: 10.1155/2015/319745] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Revised: 08/26/2015] [Accepted: 08/30/2015] [Indexed: 02/07/2023]
Abstract
Nonalcoholic fatty liver disease (NAFLD) has become a major health issue in western countries in parallel with the dramatic increase in the prevalence of obesity and all obesity related conditions, including respiratory diseases as obstructive sleep apnea-hypopnea syndrome (OSAHS). Interestingly, the severity of the liver damage in obesity-related NAFLD has been associated with the concomitant presence of OSAHS. In the presence of obesity, the proinflammatory state in these patients together with intermittent episodes of hypoxia, characteristic of OSAHS pathogenesis, may lead to an enhanced inflammatory response mediated by a positive feedback loop mechanism that implicates HIF-1 and NFκB. Thus, the severity of liver involvement in obese NAFLD patients with a concomitant diagnosis of OSAHS could be explained. In this review, we focus on the molecular mechanisms underlying the hepatic response to chronic intermittent hypoxia and its interaction with innate immunity in obesity-related NAFLD.
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407
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Linden MA, Fletcher JA, Morris EM, Meers GM, Laughlin MH, Booth FW, Sowers JR, Ibdah JA, Thyfault JP, Rector RS. Treating NAFLD in OLETF rats with vigorous-intensity interval exercise training. Med Sci Sports Exerc 2015; 47:556-67. [PMID: 24983336 DOI: 10.1249/mss.0000000000000430] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
BACKGROUND There is increasing use of high-intensity interval-type exercise training in the management of many lifestyle-related diseases. PURPOSE This study aimed to test the hypothesis that vigorous-intensity interval exercise is as effective as traditional moderate-intensity aerobic exercise training for nonalcoholic fatty liver disease (NAFLD) outcomes in obese, Otsuka Long-Evans Tokushima Fatty (OLETF) rats. METHODS OLETF rats (age, 20 wk; n = 8-10 per group) were assigned to sedentary (O-SED), moderate-intensity exercise training (O-MOD EX; 20 m·min(-1), 15% incline, 60 min·d(-1), 5 d·wk(-1) of treadmill running), or vigorous-intensity interval exercise training (O-VIG EX; 40 m·min(-1), 15% incline, 6 × 2.5 min bouts per day, 5 d·wk(-1) of treadmill running) groups for 12 wk. RESULTS Both MOD EX and VIG EX effectively lowered hepatic triglycerides, serum alanine aminotransferase (ALT), perivenular fibrosis, and hepatic collagen 1α1 messenger RNA (mRNA) expression (vs O-SED, P < 0.05). In addition, both interventions increased hepatic mitochondrial markers (citrate synthase activity and fatty acid oxidation) and suppressed markers of de novo lipogenesis (fatty acid synthase, acetyl coenzyme A carboxylase, Elovl fatty acid elongase 6, and steroyl CoA desaturase-1), whereas only MOD EX increased hepatic mitochondrial Beta-hydroxyacyl-CoA dehydrogenase (β-HAD) activity and hepatic triglyceride export marker apoB100 and lowered fatty acid transporter CD36 compared with O-SED. Moreover, whereas total hepatic macrophage population markers (CD68 and F4/80 mRNA) did not differ among groups, MOD EX and VIG EX lowered M1 macrophage polarization markers (CD11c, interleukin-1β, and tumor necrosis factor α mRNA) and MOD EX increased M2 macrophage marker, CD206 mRNA, compared with O-SED. CONCLUSIONS The accumulation of 15 min·d(-1) of VIG EX for 12 wk had similar effectiveness as 60 min·d(-1) of MOD EX in the management of NAFLD in OLETF rats. These findings may have important health outcome implications as we work to design better exercise training programs for patients with NAFLD.
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Affiliation(s)
- Melissa A Linden
- 1Research Service-Harry S. Truman Memorial Veterans Medical Center, Columbia, MO; 2Department of Medicine, Division of Gastroenterology and Hepatology, University of Missouri, Columbia, MO; 3Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO; 4Department of Biomedical Sciences, University of Missouri, Columbia, MO; 5Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO; 6Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO; and 7Department of Medicine, Division of Endocrinology, University of Missouri, Columbia, MO
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408
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Guo S, Yang C, Diao B, Huang X, Jin M, Chen L, Yan W, Ning Q, Zheng L, Wu Y, Chen Y. The NLRP3 Inflammasome and IL-1β Accelerate Immunologically Mediated Pathology in Experimental Viral Fulminant Hepatitis. PLoS Pathog 2015; 11:e1005155. [PMID: 26367131 PMCID: PMC4569300 DOI: 10.1371/journal.ppat.1005155] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 08/18/2015] [Indexed: 02/06/2023] Open
Abstract
Viral fulminant hepatitis (FH) is a severe disease with high mortality resulting from excessive inflammation in the infected liver. Clinical interventions have been inefficient due to the lack of knowledge for inflammatory pathogenesis in the virus-infected liver. We show that wild-type mice infected with murine hepatitis virus strain-3 (MHV-3), a model for viral FH, manifest with severe disease and high mortality in association with a significant elevation in IL-1β expression in the serum and liver. Whereas, the viral infection in IL-1β receptor-I deficient (IL-1R1-/-) or IL-1R antagonist (IL-1Ra) treated mice, show reductions in virus replication, disease progress and mortality. IL-1R1 deficiency appears to debilitate the virus-induced fibrinogen-like protein-2 (FGL2) production in macrophages and CD45+Gr-1high neutrophil infiltration in the liver. The quick release of reactive oxygen species (ROS) by the infected macrophages suggests a plausible viral initiation of NLRP3 inflammasome activation. Further experiments show that mice deficient of p47phox, a nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunit that controls acute ROS production, present with reductions in NLRP3 inflammasome activation and subsequent IL-1β secretion during viral infection, which appears to be responsible for acquiring resilience to viral FH. Moreover, viral infected animals in deficiencies of NLRP3 and Caspase-1, two essential components of the inflammasome complex, also have reduced IL-1β induction along with ameliorated hepatitis. Our results demonstrate that the ROS/NLRP3/IL-1β axis institutes an essential signaling pathway, which is over activated and directly causes the severe liver disease during viral infection, which sheds light on development of efficient treatments for human viral FH and other severe inflammatory diseases. The NLRP3 inflammasome and IL-1β play essential roles in mediating the primary inflammatory responses against pathogen invasions in the host. Hyperactivation of this signaling pathway can lead to life-threatening diseases under certain circumstances. However, it is not clear if NLRP3 inflammasome activation participates in the pathogenesis of viral fulminant hepatitis (FH), a clinical severe syndrome characterized by acute inflammation in the liver along with massive necrosis of hepatocytes and hepatic encephalopathy during viral infection. Using a mouse viral FH model by infection with murine hepatitis virus strain-3 (MHV-3), we observed a significant macrophage induction and the serum and liver massive accumulation of IL-1β. Conversely, interruption of IL-1β signals results in attenuation of the MHV-3-induced hepatitis and mortality. Blocking IL-1β activity reduces the virus-induced expression of fibrinogen-like protein-2 (FGL2) in macrophages, and limits the liver recruitment of CD45+Gr-1high neutrophils upon the virus infection. We further show that proIL-1β is bioprocessed by NLRP3 inflammasome. Deletion of the components in the inflammasome complex, including NLRP3 and Caspase-1, leads to reduction in the virus-induced IL-1β production and lessening of disease progression. Further studies show that macrophages in deficiency of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunit p47phox, a protein that controls acute ROS production, prevents NLRP3 inflammasome activation and IL-1β secretion, suggesting that the virus-induced ROS production can directly initiate NLRP3 inflammasome activation. Therefore, p47phox-/- mice exhibited certain degrees of MHV-3 resistance. Taken together, these results demonstrate that ROS/NLRP3/IL-1β is the key pathway signaling exacerbated inflammatory responses that cause viral FH in mice, suggesting that mediation of this signal cascade may benefit on the disease treatment.
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Affiliation(s)
- Sheng Guo
- Institute of Immunology, PLA, Third Military Medical University, Chongqing, China
| | - Chengying Yang
- Institute of Immunology, PLA, Third Military Medical University, Chongqing, China
| | - Bo Diao
- Institute of Immunology, PLA, Third Military Medical University, Chongqing, China
| | - Xiaoyong Huang
- Institute of Immunology, PLA, Third Military Medical University, Chongqing, China
| | - Meihua Jin
- Department of Pharmacology, Yanbian University, Yanji, Jilin province, China
| | - Lili Chen
- Department of Basic Medicine, Yanbian University, Yanji, Jilin province, China
| | - Weiming Yan
- Department and Institute of Infectious Disease, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Qin Ning
- Department and Institute of Infectious Disease, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Lixin Zheng
- Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Yuzhang Wu
- Institute of Immunology, PLA, Third Military Medical University, Chongqing, China
| | - Yongwen Chen
- Institute of Immunology, PLA, Third Military Medical University, Chongqing, China
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409
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Iyer S, Upadhyay PK, Majumdar SS, Nagarajan P. Animal Models Correlating Immune Cells for the Development of NAFLD/NASH. J Clin Exp Hepatol 2015; 5:239-45. [PMID: 26628841 PMCID: PMC4632099 DOI: 10.1016/j.jceh.2015.06.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 06/08/2015] [Indexed: 02/08/2023] Open
Abstract
This review mainly elaborates on the animal models available for understanding the pathogenesis of the second hit of non-alcoholic fatty liver disease (NAFLD) involving immune system. This is known to be a step forward from simple steatosis caused during the first hit, which leads to the stage of inflammation followed by more serious liver conditions like non-alcoholic steatohepatitis (NASH) and cirrhosis. Immune-deficient animal models serve as an important tool for understanding the role of a specific cell type or a cytokine in the progression of NAFLD. These animal models can be used in combination with the already available animal models of NAFLD, including dietary models, as well as genetically modified mouse models. Advancements in molecular biological techniques enabled researchers to produce several new animal models for the study of NAFLD, including knockin, generalized knockout, and tissue-specific knockout mice. Development of NASH/NAFLD in various animal models having compromised immune system is discussed in this review.
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Key Words
- APPs, acute-phase proteins
- BAFF, B cell activating factor
- Btk, Bruton's tyrosine kinase gene
- DAMPs, damage-associated molecular patterns
- HCC, hepatocellular carcinoma
- IRFs, Interferon regulatory factors
- JNK, c-Jun N-terminal kinase
- MCD, methionine choline-deficient
- NAFLD
- NAFLD, non-alcoholic fatty liver disease
- NASH, non-alcoholic steatohepatitis
- NLRs, Nod-like receptors
- PAMPs, pathogen-associated molecular patterns
- immune cells
- mouse models
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Affiliation(s)
| | | | | | - Perumal Nagarajan
- Address for correspondence: Perumal Nagarajan, National Institute of Immunology, Experimental Animal Facility, JNU Campus, New Delhi 110067, India. Tel.: +91 11 26703709; fax: +91 11 26742125.
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410
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Pizarro M, Solís N, Quintero P, Barrera F, Cabrera D, Santiago PR, Arab JP, Padilla O, Roa JC, Moshage H, Wree A, Inzaugarat E, Feldstein AE, Fardella CE, Baudrand R, Riquelme A, Arrese M. Beneficial effects of mineralocorticoid receptor blockade in experimental non-alcoholic steatohepatitis. Liver Int 2015; 35:2129-38. [PMID: 25646700 PMCID: PMC4522413 DOI: 10.1111/liv.12794] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 01/28/2015] [Indexed: 12/14/2022]
Abstract
BACKGROUND Therapeutic options to treat Non-alcoholic steatohepatitis (NASH) are limited. Mineralocorticoid receptor (MR) activation could play a role in hepatic fibrogenesis and its modulation could be beneficial for NASH. AIM To investigate whether eplerenone, a specific MR antagonist, ameliorates liver damage in experimental NASH. METHODS C57bl6 mice were fed a choline-deficient and amino acid-defined (CDAA) diet for 22 weeks with or without eplerenone supplementation. Serum levels of aminotransferases and aldosterone were measured and hepatic steatosis, inflammation and fibrosis scored histologically. Hepatic triglyceride content (HTC) and hepatic mRNA levels of pro-inflammatory pro-fibrotic, oxidative stress-associated genes and of MR were also assessed. RESULTS CDAA diet effectively induced fibrotic NASH, and increased the hepatic expression of pro-inflammatory, pro-fibrotic and oxidative stress-associated genes. Hepatic MR mRNA levels significantly correlated with the expression of pro-inflammatory and pro-fibrotic genes and were significantly increased in hepatic stellate cells obtained from CDAA-fed animals. Eplerenone administration was associated to a reduction in histological steatosis and attenuation of liver fibrosis development, which was associated to a significant decrease in the expression of collagen-α1, collagen type III, alpha 1 and Matrix metalloproteinase-2. CONCLUSION The expression of MR correlates with inflammation and fibrosis development in experimental NASH. Specific MR blockade with eplerenone has hepatic anti-steatotic and anti-fibrotic effects. These data identify eplerenone as a potential novel therapy for NASH. Considering its safety and FDA-approved status, human studies are warranted.
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Affiliation(s)
- Margarita Pizarro
- Departamento de Gastroenterología, Escuela de Medicina, Pontificia Universidad Catolica de Chile, Santiago, Chile
| | - Nancy Solís
- Departamento de Gastroenterología, Escuela de Medicina, Pontificia Universidad Catolica de Chile, Santiago, Chile
| | - Pablo Quintero
- Departamento de Gastroenterología, Escuela de Medicina, Pontificia Universidad Catolica de Chile, Santiago, Chile
| | - Francisco Barrera
- Departamento de Gastroenterología, Escuela de Medicina, Pontificia Universidad Catolica de Chile, Santiago, Chile
| | - Daniel Cabrera
- Departamento de Gastroenterología, Escuela de Medicina, Pontificia Universidad Catolica de Chile, Santiago, Chile,Departamento de Ciencias Químico-Biológicas, Universidad Bernardo O'Higgins, Santiago, Chile
| | - Pamela Rojasde Santiago
- Departamento de Gastroenterología, Escuela de Medicina, Pontificia Universidad Catolica de Chile, Santiago, Chile
| | - Juan Pablo Arab
- Departamento de Gastroenterología, Escuela de Medicina, Pontificia Universidad Catolica de Chile, Santiago, Chile
| | - Oslando Padilla
- Departamento de Salud Pública, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Juan Carlos Roa
- Departamento de Patología, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Han Moshage
- Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Alexander Wree
- Department of Pediatrics, University of California, San Diego, CA, USA
| | | | | | - Carlos E. Fardella
- Departamento de Endocrinología, Escuela de Medicina, Pontificia Universidad Catolica de Chile, Santiago, Chile
| | - Rene Baudrand
- Departamento de Endocrinología, Escuela de Medicina, Pontificia Universidad Catolica de Chile, Santiago, Chile
| | - Arnoldo Riquelme
- Departamento de Gastroenterología, Escuela de Medicina, Pontificia Universidad Catolica de Chile, Santiago, Chile
| | - Marco Arrese
- Departamento de Gastroenterología, Escuela de Medicina, Pontificia Universidad Catolica de Chile, Santiago, Chile,Corresponding author: Marco Arrese, M.D. Department of Gastroenterology Escuela de Medicina Pontificia Universidad Católica de Chile Marcoleta #367 833-0024 Santiago CHILE Phone/Fax: 56-2-6397780,
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411
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Bettaieb A, Jiang JX, Sasaki Y, Chao TI, Kiss Z, Chen X, Tian J, Katsuyama M, Yabe-Nishimura C, Xi Y, Szyndralewiez C, Schröder K, Shah A, Brandes RP, Haj FG, Török NJ. Hepatocyte Nicotinamide Adenine Dinucleotide Phosphate Reduced Oxidase 4 Regulates Stress Signaling, Fibrosis, and Insulin Sensitivity During Development of Steatohepatitis in Mice. Gastroenterology 2015; 149:468-80.e10. [PMID: 25888330 PMCID: PMC4516583 DOI: 10.1053/j.gastro.2015.04.009] [Citation(s) in RCA: 122] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 03/18/2015] [Accepted: 04/07/2015] [Indexed: 02/08/2023]
Abstract
BACKGROUND & AIMS Reactive oxidative species (ROS) are believed to be involved in the progression of nonalcoholic steatohepatitis (NASH). However, little is known about the sources of ROS in hepatocytes or their role in disease progression. We studied the effects of nicotinamide adenine dinucleotide phosphate reduced oxidase 4 (NOX4) in liver tissues from patients with NASH and mice with steatohepatitis. METHODS Liver biopsy samples were obtained from 5 patients with NASH, as well as 4 patients with simple steatosis and 5 patients without steatosis (controls) from the University of California, Davis Cancer Center Biorepository. Mice with hepatocyte-specific deletion of NOX4 (NOX4(hepKO)) and NOX4(floxp+/+) C57BL/6 mice (controls) were given fast-food diets (supplemented with high-fructose corn syrup) or choline-deficient l-amino acid defined diets to induce steatohepatitis, or control diets, for 20 weeks. A separate group of mice were given the NOX4 inhibitor (GKT137831). Liver tissues were collected and immunoblot analyses were performed determine levels of NOX4, markers of inflammation and fibrosis, double-stranded RNA-activated protein kinase, and phospho-eIF-2α kinase-mediated stress signaling pathways. We performed hyperinsulinemic-euglycemic clamp studies and immunoprecipitation analyses to determine the oxidation and phosphatase activity of PP1C. RESULTS Levels of NOX4 were increased in patients with NASH compared with controls. Hepatocyte-specific deletion of NOX4 reduced oxidative stress, lipid peroxidation, and liver fibrosis in mice with diet-induced steatohepatitis. A small molecule inhibitor of NOX4 reduced liver inflammation and fibrosis and increased insulin sensitivity in mice with diet-induced steatohepatitis. In primary hepatocytes, NOX4 reduced the activity of the phosphatase PP1C, prolonging activation of double-stranded RNA-activated protein kinase and phosphorylation of extracellular signal-regulated kinase-mediated stress signaling. Mice with hepatocyte-specific deletion of NOX4 and mice given GKT137831 had increased insulin sensitivity. CONCLUSIONS NOX4 regulates oxidative stress in the liver and its levels are increased in patients with NASH and mice with diet-induced steatohepatitis. Inhibitors of NOX4 reduce liver inflammation and fibrosis and increase insulin sensitivity, and might be developed for treatment of NASH.
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Affiliation(s)
- Ahmed Bettaieb
- Department of Nutrition, University of California Davis, Davis, California
| | - Joy X Jiang
- Department of Medicine, Gastroenterology and Hepatology, University of California Davis, and VA Medical Center, Sacramento, California
| | - Yu Sasaki
- Department of Medicine, Gastroenterology and Hepatology, University of California Davis, and VA Medical Center, Sacramento, California
| | - Tzu-I Chao
- Department of Medicine, Gastroenterology and Hepatology, University of California Davis, and VA Medical Center, Sacramento, California
| | - Zsofia Kiss
- Department of Medicine, Gastroenterology and Hepatology, University of California Davis, and VA Medical Center, Sacramento, California
| | - Xiangling Chen
- Department of Medicine, Gastroenterology and Hepatology, University of California Davis, and VA Medical Center, Sacramento, California
| | - Jijing Tian
- Department of Medicine, Gastroenterology and Hepatology, University of California Davis, and VA Medical Center, Sacramento, California
| | | | | | - Yannan Xi
- Department of Nutrition, University of California Davis, Davis, California
| | | | | | - Ajay Shah
- King's College London British Heart Foundation Centre, London, UK
| | | | - Fawaz G Haj
- Department of Nutrition, University of California Davis, Davis, California
| | - Natalie J Török
- Department of Medicine, Gastroenterology and Hepatology, University of California Davis, and VA Medical Center, Sacramento, California.
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412
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Chung KW, Lee EK, Kim DH, An HJ, Kim ND, Im DS, Lee J, Yu BP, Chung HY. Age-related sensitivity to endotoxin-induced liver inflammation: Implication of inflammasome/IL-1β for steatohepatitis. Aging Cell 2015; 14:524-33. [PMID: 25847140 PMCID: PMC4531067 DOI: 10.1111/acel.12305] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/14/2014] [Indexed: 12/22/2022] Open
Abstract
Aging is associated with increased vulnerability to inflammatory challenge. However, the effects of altered inflammatory response on the metabolic status of tissues or organs are not well documented. In this study, we present evidence demonstrating that lipopolysaccharide (LPS)-induced upregulation of the inflammasome/IL-1β pathway is accompanied with an increased inflammatory response and abnormal lipid accumulation in livers of aged rats. To monitor the effects of aging on LPS-induced inflammation, we administered LPS (2 mg kg−1) to young (6-month old) and aged (24-month old) rats and found abnormal lipid metabolism in only aged rats with increased lipid accumulation in the liver. This lipid accumulation in the liver was due to the dysregulation of PPARα and SREBP1c. We also observed severe liver inflammation in aged rats as indicated by increased ALT levels in serum and increased Kupffer cells in the liver. Importantly, among many inflammation-associated factors, the aged rat liver showed chronically increased IL-1β production. Increased levels of IL-1β were caused by the upregulation of caspase-1 activity and inflammasome activation. In vitro studies with HepG2 cells demonstrated that treatment with IL-1β significantly induced lipid accumulation in hepatocytes through the regulation of PPARα and SREBP1c. In summary, we demonstrated that LPS-induced liver inflammation and lipid accumulation were associated with a chronically overactive inflammasome/IL-1β pathway in aged rat livers. Based on the present findings, we propose a mechanism of aging-associated progression of steatohepatitis induced by endotoxin, delineating a pathogenic role of the inflammasome/IL-1β pathway involved in lipid accumulation in the liver.
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Affiliation(s)
- Ki Wung Chung
- Molecular Inflammation Research Center for Aging Intervention (MRCA) College of Pharmacy Pusan National University Busan Korea
| | - Eun Kyeong Lee
- Molecular Inflammation Research Center for Aging Intervention (MRCA) College of Pharmacy Pusan National University Busan Korea
| | - Dae Hyun Kim
- Molecular Inflammation Research Center for Aging Intervention (MRCA) College of Pharmacy Pusan National University Busan Korea
| | - Hye Jin An
- Molecular Inflammation Research Center for Aging Intervention (MRCA) College of Pharmacy Pusan National University Busan Korea
| | - Nam Deuk Kim
- Molecular Inflammation Research Center for Aging Intervention (MRCA) College of Pharmacy Pusan National University Busan Korea
| | - Dong Soon Im
- Molecular Inflammation Research Center for Aging Intervention (MRCA) College of Pharmacy Pusan National University Busan Korea
| | - Jaewon Lee
- Molecular Inflammation Research Center for Aging Intervention (MRCA) College of Pharmacy Pusan National University Busan Korea
| | - Byung Pal Yu
- Department of Physiology The University of Texas Health Science Center at San Antonio San Antonio TX 78229‐3900USA
| | - Hae Young Chung
- Molecular Inflammation Research Center for Aging Intervention (MRCA) College of Pharmacy Pusan National University Busan Korea
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413
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Li X, Huang W, Gu J, Du X, Lei L, Yuan X, Sun G, Wang Z, Li X, Liu G. SREBP-1c overactivates ROS-mediated hepatic NF-κB inflammatory pathway in dairy cows with fatty liver. Cell Signal 2015; 27:2099-109. [PMID: 26189441 DOI: 10.1016/j.cellsig.2015.07.011] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 07/15/2015] [Accepted: 07/15/2015] [Indexed: 01/04/2023]
Abstract
Dairy cows with fatty liver are characterized by hepatic lipid accumulation and a severe inflammatory response. Sterol receptor element binding protein-1c (SREBP-1c) and nuclear factor κB (NF-κB) are components of the main pathways for controlling triglyceride (TG) accumulation and inflammatory levels, respectively. A previous study demonstrated that hepatic inflammatory levels are positively correlated with hepatic TG content. We therefore speculated that SREBP-1c might play an important role in the overactivation of the hepatic NF-κB inflammatory pathway in cows with fatty liver. Compared with healthy cows, cows with fatty liver exhibited severe hepatic injury and high blood concentrations of the inflammatory cytokines TNF-α, IL-6 and IL-1β. Hepatic SREBP-1c-mediated lipid synthesis and the NF-κB inflammatory pathway were both overinduced in cows with fatty liver. In vitro, treatment with non-esterified fatty acids (NEFA) further increased SREBP-1c expression and NF-κB pathway activation, which then promoted TG and inflammatory cytokine synthesis. SREBP-1c overexpression overactivated the NF-κB inflammatory pathway in hepatocytes by increasing ROS content and not through TLR4. Furthermore, SREBP-1c silencing decreased ROS content and further attenuated the activation of the NEFA-induced NF-κB pathway, thereby decreasing TNF-α, IL-6 and IL-1β synthesis. SREBP-1c-overexpressing mice exhibited hepatic steatosis and an overinduced hepatic NF-κB pathway. Taken together, these results indicate that SREBP-1c enhances the NEFA-induced overactivation of the NF-κB inflammatory pathway by increasing ROS in cow hepatocytes, thereby further increasing hepatic inflammatory injury in cows with fatty liver.
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Affiliation(s)
- Xinwei Li
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, 5333 Xi'an Road, Changchun, 130062 Jilin, China
| | - Weikun Huang
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, 5333 Xi'an Road, Changchun, 130062 Jilin, China
| | - Jingmin Gu
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, 5333 Xi'an Road, Changchun, 130062 Jilin, China
| | - Xiliang Du
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, 5333 Xi'an Road, Changchun, 130062 Jilin, China
| | - Lin Lei
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, 5333 Xi'an Road, Changchun, 130062 Jilin, China
| | - Xue Yuan
- College of Animal Science and Technology, Inner Mongolia National University, Tongliao 028042, China
| | - Guoquan Sun
- College of Animal Science and Technology, Inner Mongolia National University, Tongliao 028042, China
| | - Zhe Wang
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, 5333 Xi'an Road, Changchun, 130062 Jilin, China
| | - Xiaobing Li
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, 5333 Xi'an Road, Changchun, 130062 Jilin, China.
| | - Guowen Liu
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, 5333 Xi'an Road, Changchun, 130062 Jilin, China.
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414
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Fjære E, Andersen C, Myrmel LS, Petersen RK, Hansen JB, Tastesen HS, Mandrup-Poulsen T, Brünner N, Kristiansen K, Madsen L, Rømer MU. Tissue Inhibitor Of Matrix Metalloproteinase-1 Is Required for High-Fat Diet-Induced Glucose Intolerance and Hepatic Steatosis in Mice. PLoS One 2015; 10:e0132910. [PMID: 26168159 PMCID: PMC4500465 DOI: 10.1371/journal.pone.0132910] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2013] [Accepted: 06/22/2015] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Plasma levels of tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) are elevated in obesity and obesity-related disorders, such as steatosis, but the metabolic role of TIMP-1 is unclear. Here we investigated how the presence or absence of TIMP-1 affected the development of diet-induced glucose intolerance and hepatic steatosis using the Timp1 null mice. METHODS Timp1 knockout (TKO) and wild type (TWT) mice were fed chow, high-fat diet (HFD) or intermediate fat and sucrose diet (IFSD). We determined body weight, body composition, lipid content of the liver, energy intake, energy expenditure, oral glucose tolerance, as well as insulin tolerance. In addition, the histology of liver and adipose tissues was examined and expression of selected genes involved in lipid metabolism and inflammation in liver and adipose tissues was determined by RT-qPCR. RESULTS TKO mice gained less weight and had lower energy efficiency than TWT mice when fed HFD, but not when fed chow or IFSD. Importantly, TKO mice were protected from development of HFD- as well as IFSD-induced glucose intolerance, hepatic steatosis, and altered expression of genes involved in hepatic lipid metabolism and inflammation. CONCLUSION Collectively, our results indicate that TIMP-1 contributes to the development of diet-induced hepatic steatosis and glucose intolerance and may be a potential therapeutic target.
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Affiliation(s)
- Even Fjære
- Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
- National Institute of Nutrition and Seafood Research, Bergen, Norway
| | - Charlotte Andersen
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Lene Secher Myrmel
- Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
- National Institute of Nutrition and Seafood Research, Bergen, Norway
| | | | - Jakob Bondo Hansen
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, Copenhagen, University of Copenhagen, Denmark
| | - Hanne Sørup Tastesen
- Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Thomas Mandrup-Poulsen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, Copenhagen, University of Copenhagen, Denmark
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Nils Brünner
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Karsten Kristiansen
- Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Lise Madsen
- Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
- National Institute of Nutrition and Seafood Research, Bergen, Norway
- * E-mail: (MUR); (LM)
| | - Maria Unni Rømer
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
- * E-mail: (MUR); (LM)
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415
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Kirpich IA, Marsano LS, McClain CJ. Gut-liver axis, nutrition, and non-alcoholic fatty liver disease. Clin Biochem 2015; 48:923-30. [PMID: 26151226 DOI: 10.1016/j.clinbiochem.2015.06.023] [Citation(s) in RCA: 213] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2015] [Revised: 06/22/2015] [Accepted: 06/27/2015] [Indexed: 02/08/2023]
Abstract
Nonalcoholic fatty liver disease (NAFLD) represents a spectrum of diseases involving hepatic fat accumulation, inflammation with the potential progression to fibrosis and cirrhosis over time. NAFLD is often associated with obesity, insulin resistance, and diabetes. The interactions between the liver and the gut, the so-called "gut-liver axis", play a critical role in NAFLD onset and progression. Compelling evidence links the gut microbiome, intestinal barrier integrity, and NAFLD. The dietary factors may alter the gut microbiota and intestinal barrier function, favoring the occurrence of metabolic endotoxemia and low grade inflammation, thereby contributing to the development of obesity and obesity-associated fatty liver disease. Therapeutic manipulations with prebiotics and probiotics to modulate the gut microbiota and maintain intestinal barrier integrity are potential agents for NAFLD management. This review summarizes the current knowledge regarding the complex interplay between the gut microbiota, intestinal barrier, and dietary factors in NAFLD pathogenesis. The concepts addressed in this review have important clinical implications, although more work needs to be done to understand how dietary factors affect the gut barrier and microbiota, and to comprehend how microbe-derived components may interfere with the host's metabolism contributing to NAFLD development.
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Affiliation(s)
- Irina A Kirpich
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Louisville School of Medicine, 40202, Louisville, KY, USA; Department of Pharmacology and Toxicology, University of Louisville School of Medicine, 40202, Louisville, KY, USA.
| | - Luis S Marsano
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Louisville School of Medicine, 40202, Louisville, KY, USA.
| | - Craig J McClain
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Louisville School of Medicine, 40202, Louisville, KY, USA; Department of Pharmacology and Toxicology, University of Louisville School of Medicine, 40202, Louisville, KY, USA; Robley Rex Veterans Medical Center, 40202, Louisville, KY, USA.
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416
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Roh YS, Zhang B, Loomba R, Seki E. TLR2 and TLR9 contribute to alcohol-mediated liver injury through induction of CXCL1 and neutrophil infiltration. Am J Physiol Gastrointest Liver Physiol 2015; 309:G30-41. [PMID: 25930080 PMCID: PMC4491507 DOI: 10.1152/ajpgi.00031.2015] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 04/24/2015] [Indexed: 01/31/2023]
Abstract
Although previous studies reported the involvement of the TLR4-TRIF pathway in alcohol-induced liver injury, the role of TLR2 and TLR9 signaling in alcohol-mediated neutrophil infiltration and liver injury has not been elucidated. Since alcohol binge drinking is recognized to induce more severe form of alcohol liver disease, we used a chronic-binge ethanol-feeding model as a mouse model for early stage of alcoholic hepatitis. Whereas a chronic-binge ethanol feeding induced alcohol-mediated liver injury in wild-type mice, TLR2- and TLR9-deficient mice showed reduced liver injury. Induction of neutrophil-recruiting chemokines, including Cxcl1, Cxcl2, and Cxcl5, and hepatic neutrophil infiltration were increased in wild-type mice, but not in TLR2- and TLR9-deficient mice. In vivo depletion of Kupffer cells (KCs) by liposomal clodronate reduced liver injury and the expression of Il1b, but not Cxcl1, Cxcl2, and Cxcl5, suggesting that KCs are partly associated with liver injury, but not neutrophil recruitment, in a chronic-binge ethanol-feeding model. Notably, hepatocytes and hepatic stellate cells (HSCs) produce high amounts of CXCL1 in ethanol-treated mice. The treatment with TLR2 and TLR9 ligands synergistically upregulated CXCL1 expression in hepatocytes. Moreover, the inhibitors for CXCR2, a receptor for CXCL1, and MyD88 suppressed neutrophil infiltration and liver injury induced by chronic-binge ethanol treatment. Consistent with the above findings, hepatic CXCL1 expression was highly upregulated in patients with alcoholic hepatitis. In a chronic-binge ethanol-feeding model, the TLR2 and TLR9-dependent MyD88-dependent pathway mediates CXCL1 production in hepatocytes and HSCs; the CXCL1 then promotes neutrophil infiltration into the liver via CXCR2, resulting in the development of alcohol-mediated liver injury.
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Affiliation(s)
- Yoon Seok Roh
- 1Division of Gastroenterology, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California; and ,2Division of Gastroenterology, Department of Medicine, University of California, San Diego, School of Medicine, La Jolla, California
| | - Bi Zhang
- 2Division of Gastroenterology, Department of Medicine, University of California, San Diego, School of Medicine, La Jolla, California
| | - Rohit Loomba
- 2Division of Gastroenterology, Department of Medicine, University of California, San Diego, School of Medicine, La Jolla, California
| | - Ekihiro Seki
- Division of Gastroenterology, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California; and Division of Gastroenterology, Department of Medicine, University of California, San Diego, School of Medicine, La Jolla, California
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417
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Abstract
Inflammation contributes to the pathogenesis of most acute and chronic liver diseases. Inflammasomes are multiprotein complexes that can sense danger signals from damaged cells and pathogens and assemble to mediate caspase-1 activation, which proteolytically activates the cytokines IL-1β and IL-18. In contrast to other inflammatory responses, inflammasome activation uniquely requires two signals to induce inflammation, therefore setting an increased threshold. IL-1β, generated upon caspase-1 activation, provides positive feed-forward stimulation for inflammatory cytokines, thereby amplifying inflammation. Inflammasome activation has been studied in different human and experimental liver diseases and has been identified as a major contributor to hepatocyte damage, immune cell activation and amplification of liver inflammation. In this Review, we discuss the different types of inflammasomes, their activation and biological functions in the context of liver injury and disease progression. Specifically, we focus on the triggers of inflammasome activation in alcoholic steatohepatitis and NASH, chronic HCV infection, ischaemia-reperfusion injury and paracetamol-induced liver injury. The application and translation of these discoveries into therapies promises novel approaches in the treatment of inflammation in liver disease.
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Affiliation(s)
- Gyongyi Szabo
- Department of Medicine, University of Massachusetts Medical School, LRB 215, 364 Plantation Street, Worcester, MA 01605, USA
| | - Jan Petrasek
- Department of Medicine, University of Massachusetts Medical School, LRB 215, 364 Plantation Street, Worcester, MA 01605, USA
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418
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Abdul-Hai A, Abdallah A, Malnick SDH. Influence of gut bacteria on development and progression of non-alcoholic fatty liver disease. World J Hepatol 2015; 7:1679-1684. [PMID: 26140087 PMCID: PMC4483549 DOI: 10.4254/wjh.v7.i12.1679] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 03/20/2015] [Accepted: 04/20/2015] [Indexed: 02/06/2023] Open
Abstract
The intestine of the human contains a dynamic population of microbes that have a symbiotic relationship with the host. In addition, there is an effect of the intestinal microbiota on metabolism and digestion. Non-alcoholic fatty liver disease (NAFLD) is a common cause worldwide of hepatic pathology and is thought to be the hepatic manifestation of the metabolic syndrome. In this review we examine the effect of the human microbiome on the components and pathogenesis of the metabolic syndrome. We are now on the threshold of therapeutic interventions on the human microbiome in order to effect human disease including NAFLD.
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419
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Csak T, Bala S, Lippai D, Kodys K, Catalano D, Iracheta-Vellve A, Szabo G. MicroRNA-155 Deficiency Attenuates Liver Steatosis and Fibrosis without Reducing Inflammation in a Mouse Model of Steatohepatitis. PLoS One 2015; 10:e0129251. [PMID: 26042593 PMCID: PMC4456142 DOI: 10.1371/journal.pone.0129251] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 05/06/2015] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND & AIM MicroRNAs (miRs) regulate hepatic steatosis, inflammation and fibrosis. Fibrosis is the consequence of chronic tissue damage and inflammation. We hypothesized that deficiency of miR-155, a master regulator of inflammation, attenuates steatohepatitis and fibrosis. METHODS Wild type (WT) and miR-155-deficient (KO) mice were fed methionine-choline-deficient (MCD) or -supplemented (MCS) control diet for 5 weeks. Liver injury, inflammation, steatosis and fibrosis were assessed. RESULTS MCD diet resulted in steatohepatitis and increased miR-155 expression in total liver, hepatocytes and Kupffer cells. Steatosis and expression of genes involved in fatty acid metabolism were attenuated in miR-155 KO mice after MCD feeding. In contrast, miR-155 deficiency failed to attenuate inflammatory cell infiltration, nuclear factor κ beta (NF-κB) activation and enhanced the expression of the pro-inflammatory cytokines tumor necrosis factor alpha (TNFα) and monocyte chemoattractant protein-1 (MCP1) in MCD diet-fed mice. We found a significant attenuation of apoptosis (cleaved caspase-3) and reduction in collagen and α smooth muscle actin (αSMA) levels in miR-155 KO mice compared to WTs on MCD diet. In addition, we found attenuation of platelet derived growth factor (PDGF), a pro-fibrotic cytokine; SMAD family member 3 (Smad3), a protein involved in transforming growth factor-β (TGFβ) signal transduction and vimentin, a mesenchymal marker and indirect indicator of epithelial-to-mesenchymal transition (EMT) in miR-155 KO mice. Nuclear binding of CCAAT enhancer binding protein β (C/EBPβ) a miR-155 target involved in EMT was significantly increased in miR-155 KO compared to WT mice. CONCLUSIONS Our novel data demonstrate that miR-155 deficiency can reduce steatosis and fibrosis without decreasing inflammation in steatohepatitis.
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Affiliation(s)
- Timea Csak
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Shashi Bala
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Dora Lippai
- 2nd Department of Medicine, Semmelweis University, Budapest, Hungary
| | - Karen Kodys
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Donna Catalano
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Arvin Iracheta-Vellve
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Gyongyi Szabo
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
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420
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Joshi-Barve S, Kirpich I, Cave MC, Marsano LS, McClain CJ. Alcoholic, Nonalcoholic, and Toxicant-Associated Steatohepatitis: Mechanistic Similarities and Differences. Cell Mol Gastroenterol Hepatol 2015; 1:356-367. [PMID: 28210688 PMCID: PMC5301292 DOI: 10.1016/j.jcmgh.2015.05.006] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 05/27/2015] [Indexed: 12/12/2022]
Abstract
Hepatic steatosis and steatohepatitis are common histologic findings that can be caused by multiple etiologies. The three most frequent causes for steatosis/steatohepatitis are alcohol (alcoholic steatohepatitis, ASH), obesity/metabolic syndrome (nonalcoholic steatohepatitis, NASH), and environmental toxicants (toxicant-associated steatohepatitis, TASH). Hepatic steatosis is an early occurrence in all three forms of liver disease, and they often share common pathways to disease progression/severity. Disease progression is a result of both direct effects on the liver as well as indirect alterations in other organs/tissues such as intestine, adipose tissue, and the immune system. Although the three liver diseases (ASH, NASH, and TASH) share many common pathogenic mechanisms, they also exhibit distinct differences. Both shared and divergent mechanisms can be potential therapeutic targets. This review provides an overview of selected important mechanistic similarities and differences in ASH, NASH, and TASH.
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Key Words
- ALD, alcoholic liver disease
- ALT, alanine aminotransferase
- ASH, alcoholic steatohepatitis
- AST, aspartate transaminase
- Alcoholic Steatohepatitis
- BMI, body mass index
- CYP2E1, cytochrome P450 isoform 2E1
- ECM, extracellular matrix
- ER, endoplasmic reticulum
- HCC, hepatocellular carcinoma
- HDAC, histone deacetylase
- HSC, hepatic stellate cell
- IL, interleukin
- LA, linoleic acid
- LPS, lipopolysaccharide
- Mechanisms
- NAFLD, nonalcoholic fatty liver disease
- NASH, nonalcoholic steatohepatitis
- NK, natural killer
- NKT, natural killer T
- Nonalcoholic Steatohepatitis
- OXLAM, oxidized linoleic acid metabolite
- PAI-1, plasminogen activator inhibitor-1
- PCB153, 2,2′,4,4′,5,5′-hexachlorobiphenyl
- PPAR, peroxisome proliferator-activated receptor
- RNS, reactive nitrogen species
- SNP, single-nucleotide polymorphism
- TAFLD, toxicant-associated fatty liver disease
- TASH, toxicant-associated steatohepatitis
- TCDD, 2,3,7,8-tetrachlorodibenzo-p-dioxin
- TH, helper T cell
- TLR, Toll-like receptor
- TNF, tumor necrosis factor
- Toxicant-Associated Steatohepatitis
- VA, U.S. Department of Veterans Affairs/Veterans Administration
- miR, microRNA
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Affiliation(s)
- Swati Joshi-Barve
- Division of Gastroenterology, Hepatology and Nutrition, School of Medicine, University of Louisville, Louisville, Kentucky,Department of Medicine, School of Medicine, University of Louisville, Louisville, Kentucky,Department of Pharmacology and Toxicology, School of Medicine, University of Louisville, Louisville, Kentucky
| | - Irina Kirpich
- Division of Gastroenterology, Hepatology and Nutrition, School of Medicine, University of Louisville, Louisville, Kentucky,Department of Medicine, School of Medicine, University of Louisville, Louisville, Kentucky,Department of Pharmacology and Toxicology, School of Medicine, University of Louisville, Louisville, Kentucky
| | - Matthew C. Cave
- Division of Gastroenterology, Hepatology and Nutrition, School of Medicine, University of Louisville, Louisville, Kentucky,Department of Medicine, School of Medicine, University of Louisville, Louisville, Kentucky,Department of Pharmacology and Toxicology, School of Medicine, University of Louisville, Louisville, Kentucky,Robley Rex Veterans Affairs Medical Center, Louisville, Kentucky
| | - Luis S. Marsano
- Division of Gastroenterology, Hepatology and Nutrition, School of Medicine, University of Louisville, Louisville, Kentucky,Department of Medicine, School of Medicine, University of Louisville, Louisville, Kentucky,Robley Rex Veterans Affairs Medical Center, Louisville, Kentucky
| | - Craig J. McClain
- Division of Gastroenterology, Hepatology and Nutrition, School of Medicine, University of Louisville, Louisville, Kentucky,Department of Medicine, School of Medicine, University of Louisville, Louisville, Kentucky,Department of Pharmacology and Toxicology, School of Medicine, University of Louisville, Louisville, Kentucky,Robley Rex Veterans Affairs Medical Center, Louisville, Kentucky,Correspondence Address correspondence to: Craig J. McClain, MD, University of Louisville, 505 South Hancock Street, Louisville, Kentucky 40292. fax: (502) 852-8927.
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421
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Choline and Cystine Deficient Diets in Animal Models with Hepatocellular Injury: Evaluation of Oxidative Stress and Expression of RAGE, TNF-α, and IL-1β. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015; 2015:121925. [PMID: 26137185 PMCID: PMC4468296 DOI: 10.1155/2015/121925] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Revised: 05/15/2015] [Accepted: 05/18/2015] [Indexed: 02/06/2023]
Abstract
This study aims to evaluate the effects of diets deficient in choline and/or cystine on hepatocellular injury in animal models (young male Wistar rats, aged 21 days), by monitoring some of the oxidative stress biomarkers and the expression of RAGE, TNF-α, and IL-1β. The animals were divided into 6 groups (n = 10) and submitted to different diets over 30 days: AIN-93 diet (standard, St), AIN-93 choline deficient (CD) diet and AIN-93 choline and cystine deficient (CCD) diet, in the pellet (pl) and powder (pw) diet forms. Independently of the diet form, AIN-93 diet already led to hepatic steatosis and CD/CCD diets provoked hepatic damage. The increase of lipid peroxidation, represented by the evaluation of thiobarbituric acid reactive species, associated with the decrease of levels of antioxidant enzymes, were the parameters with higher significance toward redox profile in this model of hepatic injury. Regarding inflammation, in relation to TNF-α, higher levels were evidenced in CD(pl), while, for IL-1β, no significant alteration was detected. RAGE expression was practically the same in all groups, with exception of CCD(pw) versus CCD(pl). These results together confirm that AIN-93 causes hepatic steatosis and choline and/or cysteine deficiencies produce important hepatic injury associated with oxidative stress and inflammatory profiles.
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422
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Sharma M, Mitnala S, Vishnubhotla RK, Mukherjee R, Reddy DN, Rao PN. The Riddle of Nonalcoholic Fatty Liver Disease: Progression From Nonalcoholic Fatty Liver to Nonalcoholic Steatohepatitis. J Clin Exp Hepatol 2015; 5:147-58. [PMID: 26155043 PMCID: PMC4491606 DOI: 10.1016/j.jceh.2015.02.002] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 02/09/2015] [Indexed: 02/07/2023] Open
Abstract
Nonalcoholic fatty liver (NAFL) is an emerging global epidemic which progresses to nonalcoholic steatohepatitis (NASH) and cirrhosis in a subset of subjects. Various reviews have focused on the etiology, epidemiology, pathogenesis and treatment of NAFLD. This review highlights specifically the triggers implicated in disease progression from NAFL to NASH. The integrating role of genes, dietary factors, innate immunity, cytokines and gut microbiome have been discussed.
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Key Words
- AGE, Advanced glycation end products
- ALT, Alanine aminotransferase
- AMPK, AMP-activated protein Kinase
- APPL1 and 2, Adaptor protein 1 and 2
- ATP, Adenosine tri-phosphatase
- BMI, Basal Metabolic Index
- CD, Cluster of differentiation
- COL13A1, Collagen, type XIII, alpha 1
- DAMP, Damage assocauted molecular pattern molecules
- EFCAB4B, EF-hand calcium binding domain 4B
- FA, Fatty acid
- FDFT1, Farnesyl-diphosphate farnesyltransferase 1
- FFA, Free fatty acid
- GCKR, Glucokinase regulatory protein
- GLUT 5, Glucose transporter type 5
- GWAS, Genome wide association studies
- HDL, High density lipoprotein
- HMGB1, High-mobility group protein B1
- HOMA-IR, Homoestatic model assessment-insulin resistance
- HSC, Hepatic Stellate Cells
- Hh, Hedgehog
- IL6, Interleukin 6
- IR, Insulin Resistance
- KC, Kupffer Cells
- LPS, Lipopolysacharrides
- LYPLAL1, Lypophospholipase like 1
- MCP, Monocyte chemotactic protein
- NAD, Nicotinamide adenine dinucleotide
- NAFL, Nonalcoholic fatty liver
- NAFLD, Nonalcoholic fatty liver disease
- NASH, Nonalcoholic steatohepatitis
- NCAN, Neurocan gene
- NF-KB, Nuclear Factor Kappa B
- NK, Natural Killer
- NKL, Natural Killer T cells
- NLR, NOD like receptor
- NNMT, Nicotinamide N-methyltransferase gene
- OXLAM, Oxidized linolenic acid metabolite
- PAMP, Pathogen-associated Molecular pattern
- PARVB, Beta Parvin Gene
- PDGF, Platelet-derived growth factor
- PNPLA3
- PNPLA3, Patatin-like phospholipase domain-containing protein 3
- PPAR-α, Peroxisome proliferator activated receptor alpha
- PPP1R3B, Protein phosphatase 1 R3B
- PUFA, Poly unsaturated fatty acid
- PZP, Pregnancy-zone protein
- ROS, Reactive oxygen species
- SAMM, Sorting and assembly machinery component
- SCAP, SREBP cleavage-activating protein
- SFA, Saturated fatty acid
- SNP, Single nucleotide polymorphism
- SOCS3, Suppressor of cytokine signaling 3
- SOD2, Superoxide dismutase 2 gene
- SREBP-1C, Sterol regulatory Element—Binding Protein 1-C gene
- TLR, Toll like receptor
- TNF α, Tumor necrosis factor Alpha
- UCP3, Uncoupling protein 3 gene
- adiponectin
- cytokines
- gut microbiota
- lipotoxicity
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Affiliation(s)
- Mithun Sharma
- Department of Hepatology and Nutrition, Asian Institute of Gastroenterology, Hyderabad, Telangana, India,Address for correspondence: Mithun Sharma, Consultant Hepatologist, Asian Institute of Gastroenterology, 6-3-661, Red Rose Café Lane, Somajigudda, Hyderabad 500082, India. Tel.: +91 8790622655.
| | - Shasikala Mitnala
- Research Labs, Institute of Basic Sciences and Translational Research, Asian Healthcare Foundation, Asian Institute of Gastroenterology, Hyderabad, Telangana, India
| | - Ravi K. Vishnubhotla
- Department of Genetics, Asian Healthcare Foundation, Asian Institute of Gastroenterology, Hyderabad, Telangana, India
| | - Rathin Mukherjee
- Department of Molecular Biology, Asian Healthcare Foundation, Asian Institute of Gastroenterology, Hyderabad, Telangana, India
| | - Duvvur N. Reddy
- Department of Gastroenterology, Asian Healthcare Foundation, Asian Institute of Gastroenterology, Hyderabad, Telangana, India
| | - Padaki N. Rao
- Department of Hepatology and Nutrition, Asian Healthcare Foundation, Asian Institute of Gastroenterology, Hyderabad, Telangana, India
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423
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Alvarado-Vásquez N. Circulating cell-free mitochondrial DNA as the probable inducer of early endothelial dysfunction in the prediabetic patient. Exp Gerontol 2015; 69:70-8. [PMID: 26026597 DOI: 10.1016/j.exger.2015.05.010] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 05/09/2015] [Accepted: 05/25/2015] [Indexed: 12/16/2022]
Abstract
Recent evidence has shown that 346million people in the world have diabetes mellitus (DM); this number will increase to 439million by 2030. In addition, current data indicate an increase in DM cases in the population between 40 and 59years of age. Diabetes is associated with the development of micro- and macro-vascular complications, derived from chronic hyperglycemia on the endothelium. Some reports demonstrate that people in a prediabetic state have a major risk of developing early endothelial dysfunction (ED). Today, it is accepted that individuals considered as prediabetic patients are in a pro-inflammatory state associated with endothelial and mitochondrial dysfunction. It is important to mention that impaired mitochondrial functionality has been linked to endothelial apoptosis and release of mitochondrial DNA (mtDNA) in patients with sepsis, cardiac disease, or atherosclerosis. This free mtDNA could promote ED, as well as other side effects on the vascular system through the activation of the toll-like receptor 9 (TLR9). TLR9 is expressed in different cell types (e.g., T or B lymphocytes, mastocytes, and epithelial and endothelial cells). It is localized intracellularly and recognizes non-methylated dinucleotides of viral, bacterial, and mitochondrial DNA. Recently, it has been reported that TLR9 is associated with the pathogenesis of lupus erythematosus, rheumatoid arthritis, and autoimmune diabetes. In this work, it is hypothesized that the increase in the levels of circulating mtDNA is the trigger of early ED in the prediabetic patient, and later on in the older patient with diabetes, through activation of the TLR9 present in the endothelium.
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Affiliation(s)
- Noé Alvarado-Vásquez
- Department of Biochemistry, National Institute of Respiratory Diseases "Ismael Cosío Villegas", Calz. de Tlalpan 4502, Col. Sección XVI, 14080 Mexico, D.F., Mexico, Mexico.
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424
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Zhang RN, Pan Q, Zhang Z, Cao HX, Shen F, Fan JG. Saturated Fatty Acid inhibits viral replication in chronic hepatitis B virus infection with nonalcoholic Fatty liver disease by toll-like receptor 4-mediated innate immune response. HEPATITIS MONTHLY 2015; 15:e27909. [PMID: 26045709 PMCID: PMC4451278 DOI: 10.5812/hepatmon.15(5)2015.27909] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 04/09/2015] [Accepted: 04/17/2015] [Indexed: 02/06/2023]
Abstract
BACKGROUND Chronic Hepatitis B (CHB) infection is common in patients with Non-Alcoholic Fatty Liver Disease (NAFLD). The replication level of Hepatitis B Virus (HBV) was inversely correlated with hepatic steatosis. Toll-Like Receptor (TLR) 4-mediated innate immunity plays a pivotal role in the occurrence of NAFLD and controls HBV replication. OBJECTIVES This study aimed to investigate whether the TLR4-mediated innate immunity stimulates the pathogenesis of CHB in patients with NAFLD and to determine whether TLR4 plays a role in inhibiting HBV replication. MATERIALS AND METHODS The HBV transgenic mice were randomized into the HBV and HBV/NAFLD groups. HepG2.2.15 cells were treated with different concentrations (0 - 200 μM) of Stearic Acid (SA) to induce steatosis. The total RNA of the liver tissue was extracted for Real-Time Polymerase Chain Reaction (RT-PCR) detection, and immunohistochemistry or western blot was conducted for further validation. The Enzyme-Linked Immunosorbent Assay (ELISA) analysis was applied to evaluate the production of Interleukin 6 (IL-6), Tumor necrosis factor α (TNF-α) and Interferon β (IFN-β). Moreover, viral dynamics were analyzed using HBV DNA and HBV-related antigens (HBsAg and HBeAg). RESULTS Non-alcoholic fatty liver disease was induced in HBV-transgenic mice fed with High Fat Diet (HFD) for 8 - 24 weeks. Oil red-O staining positive droplets and the content of Triglyceride (TG) were increased in HepG2.2.15 cells treated with SA. TLR4, Myeloid differentiation factor 88 (MyD88), IL-6 and TNF-α expression levels were significantly higher in the HBV/NAFLD group and the steatotic HepG2.2.15 cells than those in their respective controls. Compared to the HBV group, significant reductions in serum levels of HBsAg, HBeAg, and HBV DNA titers occurred in the HBV/NAFLD group at 24 weeks, but the IFN-β level was remarkably increased. Similar data were also obtained from the steatoric HepG2.2.15 cells. CONCLUSIONS Saturated Fatty Acids (SFAs) served as a potential ligand for TLR4 and activated TLR4 signaling pathway, which might be involved in the pathogenesis. Thus, SFAs can accelerate the mechanism of inhibiting HBV replication in CHB with NAFLD.
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Affiliation(s)
- Rui-Nan Zhang
- Shanghai Key Laboratory of Children’s Digestion and Nutrition, Department of Gastroenterology, XinHua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qin Pan
- Shanghai Key Laboratory of Children’s Digestion and Nutrition, Department of Gastroenterology, XinHua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zheng Zhang
- Shanghai Key Laboratory of Children’s Digestion and Nutrition, Department of Gastroenterology, XinHua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hai-Xia Cao
- Shanghai Key Laboratory of Children’s Digestion and Nutrition, Department of Gastroenterology, XinHua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Feng Shen
- Shanghai Key Laboratory of Children’s Digestion and Nutrition, Department of Gastroenterology, XinHua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jian-Gao Fan
- Shanghai Key Laboratory of Children’s Digestion and Nutrition, Department of Gastroenterology, XinHua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Corresponding Author: Jian-Gao Fan, Shanghai Key Laboratory of Children’s Digestion and Nutrition, Department of Gastroenterology, XinHua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. Tel/Fax: +86-2125077340, E-mail:
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425
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Jeftic I, Jovicic N, Pantic J, Arsenijevic N, Lukic ML, Pejnovic N. Galectin-3 Ablation Enhances Liver Steatosis, but Attenuates Inflammation and IL-33-Dependent Fibrosis in Obesogenic Mouse Model of Nonalcoholic Steatohepatitis. Mol Med 2015; 21:453-65. [PMID: 26018806 DOI: 10.2119/molmed.2014.00178] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Accepted: 05/21/2015] [Indexed: 12/14/2022] Open
Abstract
The importance of Galectin-3 (Gal-3) in obesity-associated liver pathology is incompletely defined. To dissect the role of Gal-3 in fibrotic nonalcoholic steatohepatitis (NASH), Gal-3-deficient (LGALS3(-/-)) and wild-type (LGALS3(+/+)) C57Bl/6 mice were placed on an obesogenic high fat diet (HFD, 60% kcal fat) or standard chow diet for 12 and 24 wks. Compared to WT mice, HFD-fed LGALS3(-/-) mice developed, in addition to increased visceral adiposity and diabetes, marked liver steatosis, which was accompanied with higher expression of hepatic PPAR-γ, Cd36, Abca-1 and FAS. However, as opposed to LGALS3(-/-) mice, hepatocellular damage, inflammation and fibrosis were more extensive in WT mice which had an elevated number of mature myeloid dendritic cells, proinflammatory CD11b(+)Ly6C(hi) monocytes/macrophages in liver, peripheral blood and bone marrow, and increased hepatic CCL2, F4/80, CD11c, TLR4, CD14, NLRP3 inflammasome, IL-1β and NADPH-oxidase enzymes mRNA expression. Thus, obesity-driven greater steatosis was uncoupled with attenuated fibrotic NASH in Gal-3-deficient mice. HFD-fed WT mice had a higher number of hepatocytes that strongly expressed IL-33 and hepatic CD11b(+)IL-13(+) cells, increased levels of IL-33 and IL-13 and up-regulated IL-33, ST2 and IL-13 mRNA in liver compared with LGALS3(-/-) mice. IL-33 failed to induce ST2 upregulation and IL-13 production by LGALS3(-/-) peritoneal macrophages in vitro. Administration of IL-33 in vivo enhanced liver fibrosis in HFD-fed mice in both genotypes, albeit to a significantly lower extent in LGALS3(-/-) mice, which was associated with less numerous hepatic IL-13-expressing CD11b(+) cells. The present study provides evidence of a novel role for Gal-3 in regulating IL-33-dependent liver fibrosis.
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Affiliation(s)
- Ilija Jeftic
- Center for Molecular Medicine and Stem Cell Research, Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia.,Institute of Pathophysiology, Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia
| | - Nemanja Jovicic
- Center for Molecular Medicine and Stem Cell Research, Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia.,Institute of Histology, Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia
| | - Jelena Pantic
- Center for Molecular Medicine and Stem Cell Research, Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia
| | - Nebojsa Arsenijevic
- Center for Molecular Medicine and Stem Cell Research, Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia
| | - Miodrag L Lukic
- Center for Molecular Medicine and Stem Cell Research, Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia
| | - Nada Pejnovic
- Center for Molecular Medicine and Stem Cell Research, Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia.,Institute of Pathophysiology, Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia
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426
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How Inflammation Impinges on NAFLD: A Role for Kupffer Cells. BIOMED RESEARCH INTERNATIONAL 2015; 2015:984578. [PMID: 26090470 PMCID: PMC4450298 DOI: 10.1155/2015/984578] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 03/05/2015] [Indexed: 02/06/2023]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is rapidly becoming the most prevalent cause of liver disease worldwide and afflicts adults and children as currently associated with obesity and insulin resistance. Even though lately some advances have been made to elucidate the mechanism and causes of the disease much remains unknown about NAFLD. The aim of this paper is to discuss the present knowledge regarding the pathogenesis of the disease aiming at the initial steps of NAFLD development, when inflammation impinges on fat liver deposition. At this stage, the Kupffer cells attain a prominent role. This knowledge becomes subsequently relevant for the development of future diagnostic, prevention, and therapeutic options for the management of NAFLD.
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427
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Petrasek J, Iracheta-Vellve A, Saha B, Satishchandran A, Kodys K, Fitzgerald KA, Kurt-Jones EA, Szabo G. Metabolic danger signals, uric acid and ATP, mediate inflammatory cross-talk between hepatocytes and immune cells in alcoholic liver disease. J Leukoc Biol 2015; 98:249-56. [PMID: 25934928 DOI: 10.1189/jlb.3ab1214-590r] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 04/14/2015] [Indexed: 12/12/2022] Open
Abstract
Inflammation defines the progression of ALD from reversible to advanced stages. Translocation of bacterial LPS to the liver from the gut is necessary for alcohol-induced liver inflammation. However, it is not known whether endogenous, metabolic danger signals are required for inflammation in ALD. Uric acid and ATP, 2 major proinflammatory danger signals, were evaluated in the serum of human volunteers exposed to a single dose of ethanol or in supernatants of primary human hepatocytes exposed to ethanol. In vitro studies were used to evaluate the role of uric acid and ATP in inflammatory cross-talk between hepatocytes and immune cells. The significance of signaling downstream of uric acid and ATP in the liver was evaluated in NLRP3-deficient mice fed a Lieber-DeCarli ethanol diet. Exposure of healthy human volunteers to a single dose of ethanol resulted in increased serum levels of uric acid and ATP. In vitro, we identified hepatocytes as a significant source of these endogenous inflammatory signals. Uric acid and ATP mediated a paracrine inflammatory cross-talk between damaged hepatocytes and immune cells and significantly increased the expression of LPS-inducible cytokines, IL-1β and TNF-α, by immune cells. Deficiency of NLRP3, a ligand-sensing component of the inflammasome recognizing uric acid and ATP, prevented the development of alcohol-induced liver inflammation in mice and significantly ameliorated liver damage and steatosis. Endogenous metabolic danger signals, uric acid, and ATP are involved in inflammatory cross-talk between hepatocytes and immune cells and play a crucial role in alcohol-induced liver inflammation.
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Affiliation(s)
- Jan Petrasek
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Arvin Iracheta-Vellve
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Banishree Saha
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Abhishek Satishchandran
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Karen Kodys
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Katherine A Fitzgerald
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Evelyn A Kurt-Jones
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Gyongyi Szabo
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
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428
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Abstract
The leaky gut hypothesis links translocating microbial products with the onset and progression of liver disease, and for a long time was considered one of its major contributors. However, a more detailed picture of the intestinal microbiota contributing to liver disease started to evolve. The gut is colonized by trillions of microbes that aid in digestion, modulate immune response, and generate a variety of products that result from microbial metabolic activities. These products together with host-bacteria interactions influence both normal physiology and disease susceptibility. A disruption of the symbiosis between microbiota and host is known as dysbiosis and can have profound effects on health. Qualitative changes such as increased proportions of harmful bacteria and reduced levels of beneficial bacteria, and also quantitative changes in the total amount of bacteria (overgrowth) have been associated with liver disease. Understanding the link between the pathophysiology of liver diseases and compositional and functional changes of the microbiota will help in the design of innovative therapies. In this review, we focus on factors resulting in dysbiosis, and discuss how dysbiosis can disrupt intestinal homeostasis and contribute to liver disease.
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Key Words
- dysbiosis
- leaky gut
- alcoholic liver disease
- nash
- nafld
- cirrhosis
- microbiome
- pamps
- ald, alcoholic liver disease
- amp, antimicrobial peptides and proteins
- fiaf, fasting-induced adipocyte factor
- hfd, high-fat diet
- ibd, inflammatory bowel disease
- il, interleukin
- lcfa, long-chain fatty acid
- lps, lipopolysaccharide
- nafld, nonalcoholic fatty liver disease
- nash, nonalcoholic steatohepatitis
- nlrp, nucleotide-binding domain and leucine rich repeat-containing protein
- nod2, nucleotide-binding oligomerization domain 2
- pamps, pathogen-associated molecular patterns
- reg3, regenerating islet-derived 3
- tlr, toll-like receptor
- tnf, tumor necrosis factor
- tnfr, tumor necrosis factor receptor
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Affiliation(s)
| | - Bernd Schnabl
- Department of Medicine, University of California San Diego, La Jolla, and Department of Medicine, VA San Diego Healthcare System, San Diego, California
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429
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Eckert C, Klein N, Kornek M, Lukacs-Kornek V. The complex myeloid network of the liver with diverse functional capacity at steady state and in inflammation. Front Immunol 2015; 6:179. [PMID: 25941527 PMCID: PMC4403526 DOI: 10.3389/fimmu.2015.00179] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 03/30/2015] [Indexed: 12/23/2022] Open
Abstract
In recent years, it has been an explosion of information regarding the role of various myeloid cells in liver pathology. Macrophages and dendritic cell (DC) play crucial roles in multiple chronic liver diseases such as fibrosis and non-alcoholic fatty liver disease (NAFLD). The complexity of myeloid cell populations and the missing exclusive marker combination make the interpretation of the data often extremely difficult. The current review aims to summarize the multiple roles of macrophages and DCs in chronic liver diseases, especially pointing out how these cells influence liver immune and parenchymal cells thereby altering liver function and pathology. Moreover, the review outlines the currently known marker combinations for the identification of these cell populations for the study of their role in liver immunology.
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Affiliation(s)
- Christoph Eckert
- Department of Medicine II, Saarland University Medical Center , Homburg , Germany
| | - Niklas Klein
- Department of Medicine II, Saarland University Medical Center , Homburg , Germany
| | - Miroslaw Kornek
- Department of Medicine II, Saarland University Medical Center , Homburg , Germany
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430
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Haneklaus M, O'Neill LAJ. NLRP3 at the interface of metabolism and inflammation. Immunol Rev 2015; 265:53-62. [DOI: 10.1111/imr.12285] [Citation(s) in RCA: 195] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Moritz Haneklaus
- School of Biochemistry & Immunology; Trinity Biomedical Sciences Institute; Trinity College Dublin; Dublin 2 Ireland
| | - Luke A. J. O'Neill
- School of Biochemistry & Immunology; Trinity Biomedical Sciences Institute; Trinity College Dublin; Dublin 2 Ireland
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431
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Hoque R, Mehal WZ. Inflammasomes in pancreatic physiology and disease. Am J Physiol Gastrointest Liver Physiol 2015; 308:G643-51. [PMID: 25700081 PMCID: PMC4398840 DOI: 10.1152/ajpgi.00388.2014] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 02/10/2015] [Indexed: 01/31/2023]
Abstract
In this review we summarize the role of inflammasomes in pancreatic physiology and disease with a focus on acute pancreatitis where much recent progress has been made. New findings have identified inducers of and cell specificity of inflammasome component expression in the pancreas, the contribution of inflammasome-regulated effectors to pancreatitis, and metabolic regulation of inflammasome activation, which are strong determinants of injury in pancreatitis. New areas of pancreatic biology will be highlighted in the context of our evolving understanding of gut microbiome- and injury-induced inflammasome priming, pyroptosis, and innate immune-mediated regulation of cell metabolism.
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Affiliation(s)
- Rafaz Hoque
- 1Section of Digestive Diseases, Yale University School of Medicine, New Haven, Connecticut; and
| | - Wajahat Z. Mehal
- 1Section of Digestive Diseases, Yale University School of Medicine, New Haven, Connecticut; and ,2Section of Digestive Diseases, Department of Veterans Affairs Connecticut Healthcare, West Haven, Connecticut
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432
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Seki E, Schwabe RF. Hepatic inflammation and fibrosis: functional links and key pathways. Hepatology 2015; 61:1066-79. [PMID: 25066777 PMCID: PMC4306641 DOI: 10.1002/hep.27332] [Citation(s) in RCA: 667] [Impact Index Per Article: 74.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 07/16/2014] [Indexed: 02/06/2023]
Abstract
Inflammation is one of the most characteristic features of chronic liver disease of viral, alcoholic, fatty, and autoimmune origin. Inflammation is typically present in all disease stages and associated with the development of fibrosis, cirrhosis, and hepatocellular carcinoma. In the past decade, numerous studies have contributed to improved understanding of the links between hepatic inflammation and fibrosis. Here, we review mechanisms that link inflammation with the development of liver fibrosis, focusing on the role of inflammatory mediators in hepatic stellate cell (HSC) activation and HSC survival during fibrogenesis and fibrosis regression. We will summarize the contributions of different inflammatory cells, including hepatic macrophages, T and B lymphocytes, natural killer cells and platelets, as well as key effectors, such as cytokines, chemokines, and damage-associated molecular patterns. Furthermore, we will discuss the relevance of inflammatory signaling pathways for clinical liver disease and for the development of antifibrogenic strategies.
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Affiliation(s)
- Ekihiro Seki
- Department of Medicine, University of California, San Diego, School
of Medicine, La Jolla, CA 92093, USA,Surgery, University of California, San Diego, School of Medicine, La
Jolla, CA 92093, USA
| | - Robert F. Schwabe
- Department of Medicine, Columbia University, College of Physicians
and Surgeons, New York, NY 10032, USA,Institute of Human Nutrition, Columbia University, College of
Physicians and Surgeons, New York, NY 10032, USA
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433
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Luther J, Garber JJ, Khalili H, Dave M, Bale SS, Jindal R, Motola DL, Luther S, Bohr S, Jeoung SW, Deshpande V, Singh G, Turner JR, Yarmush ML, Chung RT, Patel SJ. Hepatic Injury in Nonalcoholic Steatohepatitis Contributes to Altered Intestinal Permeability. Cell Mol Gastroenterol Hepatol 2015; 1:222-232. [PMID: 26405687 PMCID: PMC4578658 DOI: 10.1016/j.jcmgh.2015.01.001] [Citation(s) in RCA: 178] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 01/09/2015] [Indexed: 02/08/2023]
Abstract
BACKGROUND & AIMS Emerging data suggest that changes in intestinal permeability and increased gut microbial translocation contribute to the inflammatory pathway involved in nonalcoholic steatohepatitis (NASH) development. Numerous studies have investigated the association between increased intestinal permeability and NASH. Our meta-analysis of this association investigates the underlying mechanism. METHODS A meta-analysis was performed to compare the rates of increased intestinal permeability in patients with NASH and healthy controls. To further address the underlying mechanism of action, we studied changes in intestinal permeability in a diet-induced (methionine-and-choline-deficient; MCD) murine model of NASH. In vitro studies were also performed to investigate the effect of MCD culture medium at the cellular level on hepatocytes, Kupffer cells, and intestinal epithelial cells. RESULTS Nonalcoholic fatty liver disease (NAFLD) patients, and in particular those with NASH, are more likely to have increased intestinal permeability compared with healthy controls. We correlate this clinical observation with in vivo data showing mice fed an MCD diet develop intestinal permeability changes after an initial phase of liver injury and tumor necrosis factor-α (TNFα) induction. In vitro studies reveal that MCD medium induces hepatic injury and TNFα production yet has no direct effect on intestinal epithelial cells. Although these data suggest a role for hepatic TNFα in altering intestinal permeability, we found that mice genetically resistant to TNFα-myosin light chain kinase (MLCK)-induced intestinal permeability changes fed an MCD diet still develop increased permeability and liver injury. CONCLUSIONS Our clinical and experimental results strengthen the association between intestinal permeability increases and NASH and also suggest that an early phase of hepatic injury and inflammation contributes to altered intestinal permeability in a fashion independent of TNFα and MLCK.
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Affiliation(s)
- Jay Luther
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - John J. Garber
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Hamed Khalili
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Maneesh Dave
- Division of Gastroenterology, Department of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Shyam Sundhar Bale
- Center for Engineering in Medicine, Department of Surgery, Massachusetts General Hospital, and the Shriners Burns Hospital, Boston, Massachusetts
| | - Rohit Jindal
- Center for Engineering in Medicine, Department of Surgery, Massachusetts General Hospital, and the Shriners Burns Hospital, Boston, Massachusetts
| | - Daniel L. Motola
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Sanjana Luther
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Stefan Bohr
- Center for Engineering in Medicine, Department of Surgery, Massachusetts General Hospital, and the Shriners Burns Hospital, Boston, Massachusetts
| | - Soung Won Jeoung
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Vikram Deshpande
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Gurminder Singh
- Department of Pathology, University of Chicago, Chicago, Illinois
| | | | - Martin L. Yarmush
- Center for Engineering in Medicine, Department of Surgery, Massachusetts General Hospital, and the Shriners Burns Hospital, Boston, Massachusetts
| | - Raymond T. Chung
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Suraj J. Patel
- Center for Engineering in Medicine, Department of Surgery, Massachusetts General Hospital, and the Shriners Burns Hospital, Boston, Massachusetts
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434
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Kim JY, Lee DY, Lee YJ, Park KJ, Kim KH, Kim JW, Kim WH. Chronic alcohol consumption potentiates the development of diabetes through pancreatic β-cell dysfunction. World J Biol Chem 2015; 6:1-15. [PMID: 25717351 PMCID: PMC4317634 DOI: 10.4331/wjbc.v6.i1.1] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2014] [Revised: 10/29/2014] [Accepted: 12/10/2014] [Indexed: 02/05/2023] Open
Abstract
Chronic ethanol consumption is well established as a major risk factor for type-2 diabetes (T2D), which is evidenced by impaired glucose metabolism and insulin resistance. However, the relationships between alcohol consumption and the development of T2D remain controversial. In particular, the direct effects of ethanol consumption on proliferation of pancreatic β-cell and the exact mechanisms associated with ethanol-mediated β-cell dysfunction and apoptosis remain elusive. Although alcoholism and alcohol consumption are prevalent and represent crucial public health problems worldwide, many people believe that low-to-moderate ethanol consumption may protect against T2D and cardiovascular diseases. However, the J- or U-shaped curves obtained from cross-sectional and large prospective studies have not fully explained the relationship between alcohol consumption and T2D. This review provides evidence for the harmful effects of chronic ethanol consumption on the progressive development of T2D, particularly with respect to pancreatic β-cell mass and function in association with insulin synthesis and secretion. This review also discusses a conceptual framework for how ethanol-produced peroxynitrite contributes to pancreatic β-cell dysfunction and metabolic syndrome.
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435
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Ramadori P, Kroy D, Streetz KL. Immunoregulation by lipids during the development of non-alcoholic steatohepatitis. Hepatobiliary Surg Nutr 2015; 4:11-23. [PMID: 25713801 DOI: 10.3978/j.issn.2304-3881.2015.01.02] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 12/19/2014] [Indexed: 12/24/2022]
Abstract
Non-alcoholic fatty liver disease (NAFLD) represents the most common liver disorder in western countries and it is commonly associated with obesity and progression of the metabolic syndrome. Comprehending a wide spectrum of pathologic features, it is currently well recognized that a key point for the integrity of hepatocyte functionality in NAFLD is the progression from simple steatosis to non-alcoholic steatohepatitis (NASH). Indeed, activation of the innate immune system in response to hepatic metabolic stresses represents a central process that determines the evolution and the reversibility of liver damage. Despite of the burden of studies published in recent years, it is still intriguingly unclear how accumulation of lipids in hepatocytes triggers the activation of the inflammatory response leading to the recruitment of infiltrating cells of extra-hepatic origins. In this review we offer a general view on recent advances pointing out how different classes of lipids are able to specifically affect hepatocytes functionality and survival, thus differently influencing the organization of the hepatic immune response. On the other hand, we gathered recent studies intending to illustrate the basic mechanisms through which several non-parenchymal hepatic and extra-hepatic cell populations get activated in response to lipids. Finally, we indicate latter findings proposing how the immune system majorly contributes to the progression of NASH.
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Affiliation(s)
- Pierluigi Ramadori
- Department of Internal Medicine III, RWTH University Hospital, Aachen 52074, Germany
| | - Daniela Kroy
- Department of Internal Medicine III, RWTH University Hospital, Aachen 52074, Germany
| | - Konrad L Streetz
- Department of Internal Medicine III, RWTH University Hospital, Aachen 52074, Germany
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Shimozono R, Nishimura K, Akiyama H, Funamoto S, Izawa A, Sai T, Kunita K, Kainoh M, Suzuki T, Kawada N. Interferon-β Mediates Signaling Pathways Uniquely Regulated in Hepatic Stellate Cells and Attenuates the Progression of Hepatic Fibrosis in a Dietary Mouse Model. J Interferon Cytokine Res 2015; 35:464-73. [PMID: 25715168 DOI: 10.1089/jir.2014.0096] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The results of clinical and experimental studies suggest that type I interferons (IFNs) may have direct antifibrotic activity in addition to their antiviral properties. However, the mechanisms are still unclear; in particular, little is known about the antifibrotic activity of IFN-β and how its activity is distinct from that of IFN-α. Using DNA microarrays, we demonstrated that gene expression in TWNT-4 cells, an activated human hepatic stellate cell line, was remarkably altered by IFN-β more than by IFN-α. Integrated pathway enrichment analyses revealed that a variety of IFN-β-mediated signaling pathways are uniquely regulated in TWNT-4 cells, including those related to cell cycle and Toll-like receptor 4 (TLR4) signaling. To investigate the antifibrotic activity of IFN-β and the involvement of TLR4 signaling in vivo, we used mice fed a choline-deficient l-amino acid-defined diet as a model of nonalcoholic steatohepatitis-related hepatic fibrosis. In this model, the administration of IFN-β significantly attenuated augmentation of the area of liver fibrosis, with accompanying transcriptional downregulation of the TLR4 adaptor molecule MyD88. Our results provide important clues for understanding the mechanisms of the preferential antifibrotic activity of IFN-β and suggest that IFN-β itself, as well as being a modulator of its unique signaling pathway, may be a potential treatment for patients with hepatic fibrosis in a pathogenesis-independent manner.
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Affiliation(s)
- Rieko Shimozono
- 1 Pharmaceutical Research Laboratory, Toray Industries, Inc. , Kamakura, Kanagawa, Japan
| | - Kazumi Nishimura
- 1 Pharmaceutical Research Laboratory, Toray Industries, Inc. , Kamakura, Kanagawa, Japan
| | - Hideo Akiyama
- 2 New Projects Development Division, Toray Industries, Inc. , Kamakura, Kanagawa, Japan
| | - Saeko Funamoto
- 3 Department of Bio Research, Kamakura Techno-Science, Inc. , Kamakura, Kanagawa, Japan
| | - Akiko Izawa
- 1 Pharmaceutical Research Laboratory, Toray Industries, Inc. , Kamakura, Kanagawa, Japan
| | - Takafumi Sai
- 1 Pharmaceutical Research Laboratory, Toray Industries, Inc. , Kamakura, Kanagawa, Japan
| | - Kana Kunita
- 1 Pharmaceutical Research Laboratory, Toray Industries, Inc. , Kamakura, Kanagawa, Japan
| | - Mie Kainoh
- 1 Pharmaceutical Research Laboratory, Toray Industries, Inc. , Kamakura, Kanagawa, Japan
| | - Tomohiko Suzuki
- 1 Pharmaceutical Research Laboratory, Toray Industries, Inc. , Kamakura, Kanagawa, Japan
| | - Norifumi Kawada
- 4 Department of Hepatology, Graduate School of Medicine, Osaka City University , Abeno, Osaka, Japan
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437
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Li D, Wang X, Lan X, Li Y, Liu L, Yi J, Li J, Sun Q, Wang Y, Li H, Zhong N, Holmdahl R, Lu S. Down-regulation of miR-144 elicits proinflammatory cytokine production by targeting toll-like receptor 2 in nonalcoholic steatohepatitis of high-fat-diet-induced metabolic syndrome E3 rats. Mol Cell Endocrinol 2015; 402:1-12. [PMID: 25534427 DOI: 10.1016/j.mce.2014.12.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2014] [Revised: 12/06/2014] [Accepted: 12/09/2014] [Indexed: 02/06/2023]
Abstract
OBJECTIVE To analyze regulatory microRNA(s) leading to increased TLR2 expression in livers of high-fat-diet induced metabolic syndrome (HFD-MetS) in rats with non-alcoholic steatohepatitis (NASH). METHODS TLRs, inflammatory cytokines, candidate miRNAs targeting key TLR and its cellular localization were determined in liver. The miR-144 targeting TLR2 and regulating TLR2 signaling were further determined by dual luciferase reporter assay and miR-144 mimics or inhibitor. RESULTS Expression of miR-144 was negatively correlated with TLR2 expression in Kupffer cells. The miR-144 bound to 3'UTR of rat TLR2 mRNA. In addition, compared to control group, TLR2, TNF-α, IFN-γ and activation of NF-κB decreased after miR-144 mimic challenge in NR8383 cells and BMM from E3 rats, which could be compensated by Pam3CSK4; while opposite effects on their expressions were observed after miR-144 inhibitor administration, augmented by Pam3CSK4. CONCLUSION Decreased miR-144 could enhance TNF-α and IFN-γ production by targeting TLR2 in vitro, and might contribute to TLR2 up-regulation and the progression of NASH in HFD-MetS E3 rats. This might offer a novel and potential target for NASH therapy.
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Affiliation(s)
- Dongmin Li
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, China; Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education of China, Beijing, China
| | - Xuan Wang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, China; Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education of China, Beijing, China
| | - Xi Lan
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, China; Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education of China, Beijing, China
| | - Yue Li
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, China; Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education of China, Beijing, China
| | - Li Liu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, China; Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education of China, Beijing, China
| | - Jing Yi
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, China; Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education of China, Beijing, China
| | - Jing Li
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, China; Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education of China, Beijing, China
| | - Qingzhu Sun
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, China; Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education of China, Beijing, China
| | - Yili Wang
- Research Institute of Cancer, Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China
| | - Hongmin Li
- School of Life Sciences, Northwest University, Xi'an, Shaanxi 710061, China
| | - Nannan Zhong
- Xi'an Health School, Xi'an, Shaanxi 710054, China
| | - Rikard Holmdahl
- Division of Medical Inflammation Research, Department of Biochemistry and Biophysics, Karolinska Institute, SE-17177 Stockholm, Sweden
| | - Shemin Lu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, China; Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education of China, Beijing, China.
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438
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Eliades M, Spyrou E. Vitamin D: A new player in non-alcoholic fatty liver disease? World J Gastroenterol 2015; 21:1718-1727. [PMID: 25684936 PMCID: PMC4323447 DOI: 10.3748/wjg.v21.i6.1718] [Citation(s) in RCA: 105] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Revised: 10/25/2014] [Accepted: 12/08/2014] [Indexed: 02/06/2023] Open
Abstract
Vitamin D through its active form 1a-25-dihydroxyvtamin D [1,25(OH)2D] is a secosteroid hormone that plays a key role in mineral metabolism. Recent years have witnessed a significant scientific interest on vitamin D and expanded its actions to include immune modulation, cell differentiation and proliferation and inflammation regulation. As our understanding of the many functions of vitamin D has grown, the presence of vitamin D deficiency has become one of the most prevalent micronutrient deficiencies worldwide. Concomitantly, non-alcoholic fatty liver disease (NAFLD) has become the most common form of chronic liver disease in western countries. NAFLD and vitamin D deficiency often coexist and epidemiologic evidence has shown that both of these conditions share several cardiometabolic risk factors. In this article we provide an overview of the epidemiology and pathophysiology linking NAFLD and vitamin D deficiency, as well as the available evidence on the clinical utility of vitamin D supplementation in NAFLD.
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439
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Scheja L, Kluwe J. Arginine and NASH--do macrophages deliver the first hit? J Hepatol 2015; 62:260-1. [PMID: 25450197 DOI: 10.1016/j.jhep.2014.11.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Revised: 11/02/2014] [Accepted: 11/04/2014] [Indexed: 02/06/2023]
Affiliation(s)
- Ludger Scheja
- Department of Biochemistry and Molecular Cell Biology, Hamburg University Medical Center, Hamburg, Germany
| | - Johannes Kluwe
- Department of Gastroenterology and Hepatology, Hamburg University Medical Center, Hamburg, Germany.
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440
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Dey A, Allen J, Hankey-Giblin PA. Ontogeny and polarization of macrophages in inflammation: blood monocytes versus tissue macrophages. Front Immunol 2015; 5:683. [PMID: 25657646 PMCID: PMC4303141 DOI: 10.3389/fimmu.2014.00683] [Citation(s) in RCA: 122] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Accepted: 12/17/2014] [Indexed: 12/23/2022] Open
Abstract
The explosion of new information in recent years on the origin of macrophages in the steady-state and in the context of inflammation has opened up numerous new avenues of investigation and possibilities for therapeutic intervention. In contrast to the classical model of macrophage development, it is clear that tissue-resident macrophages can develop from yolk sac-derived erythro-myeloid progenitors, fetal liver progenitors, and bone marrow-derived monocytes. Under both homeostatic conditions and in response to pathophysiological insult, the contribution of these distinct sources of macrophages varies significantly between tissues. Furthermore, while all of these populations of macrophages appear to be capable of adopting the polarized M1/M2 phenotypes, their respective contribution to inflammation, resolution of inflammation, and tissue repair remains poorly understood and is likely to be tissue- and disease-dependent. A better understanding of the ontology and polarization capacity of macrophages in homeostasis and disease will be essential for the development of novel therapies that target the inherent plasticity of macrophages in the treatment of acute and chronic inflammatory disease.
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Affiliation(s)
- Adwitia Dey
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University , University Park, PA , USA ; Graduate Program in Physiology, The Pennsylvania State University , University Park, PA , USA
| | - Joselyn Allen
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University , University Park, PA , USA ; Graduate Program in Immunology and Infectious Disease, The Pennsylvania State University , University Park, PA , USA
| | - Pamela A Hankey-Giblin
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University , University Park, PA , USA ; Graduate Program in Physiology, The Pennsylvania State University , University Park, PA , USA ; Graduate Program in Immunology and Infectious Disease, The Pennsylvania State University , University Park, PA , USA
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441
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Tse E, Helbig KJ, Van der Hoek K, McCartney EM, Van der Hoek M, George J, Beard MR. Fatty Acids Induce a Pro-Inflammatory Gene Expression Profile in Huh-7 Cells That Attenuates the Anti-HCV Action of Interferon. J Interferon Cytokine Res 2015; 35:392-400. [PMID: 25588104 DOI: 10.1089/jir.2014.0165] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The pathogenesis of nonalcoholic steatohepatitis is primarily an immune-driven disease and a known factor associated with treatment failure of chronic hepatitis C with interferon (IFN) and ribavirin. We studied the hepatocyte response in a model of steatosis at the transcriptome level and the antiviral action of IFN against hepatitis C virus (HCV) in this setting. In this study, we have shown that lipid loading (oleic acid and palmitic acid, OA:PA) of Huh-7 cells leads to increased expression of classical interferon-stimulated genes (ISGs) and NF-κβ-dependent pro-inflammatory genes. A selective blocker of Toll-like receptor (TLR)2 signaling suppressed NF-κβ promoter activity by OA:PA, suggesting that free fatty acids (FFAs) act as a TLR2 pathogen-associated molecular pattern. Furthermore, in the presence of OA:PA, IFN stimulation and HCV infection (Jc1) increased ISG expression. Somewhat counterintuitive to the increase in ISGs, the anti-HCV activity of IFN was attenuated in the presence of OA:PA. Interestingly, the combination of OA:PA, HCV, and IFN-α stimulation resulted in a significant increase in CXCL8 protein production, a cytokine known to have anti-IFN modulating activity. Thus, in an in vitro model of steatosis, the FFAs OA and PA drive an NF-κβ-dependent inflammatory and ISG gene expression profile via TLR2 activation. Furthermore, FFA synergistically increases IFN-driven gene expression that may account for HCV treatment failure in vivo.
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Affiliation(s)
- Edmund Tse
- 1 School of Molecular and Biomedical Science, The University of Adelaide , Adelaide, South Australia, Australia
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442
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Hematopoietic IKBKE limits the chronicity of inflammasome priming and metaflammation. Proc Natl Acad Sci U S A 2015; 112:506-11. [PMID: 25540417 PMCID: PMC4299251 DOI: 10.1073/pnas.1414536112] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Obesity increases the risk of developing life-threatening metabolic diseases including cardiovascular disease, fatty liver disease, diabetes, and cancer. Efforts to curb the global obesity epidemic and its impact have proven unsuccessful in part by a limited understanding of these chronic progressive diseases. It is clear that low-grade chronic inflammation, or metaflammation, underlies the pathogenesis of obesity-associated type 2 diabetes and atherosclerosis. However, the mechanisms that maintain chronicity and prevent inflammatory resolution are poorly understood. Here, we show that inhibitor of κB kinase epsilon (IKBKE) is a novel regulator that limits chronic inflammation during metabolic disease and atherosclerosis. The pathogenic relevance of IKBKE was indicated by the colocalization with macrophages in human and murine tissues and in atherosclerotic plaques. Genetic ablation of IKBKE resulted in enhanced and prolonged priming of the NLRP3 inflammasome in cultured macrophages, in hypertrophic adipose tissue, and in livers of hypercholesterolemic mice. This altered profile associated with enhanced acute phase response, deregulated cholesterol metabolism, and steatoheptatitis. Restoring IKBKE only in hematopoietic cells was sufficient to reverse elevated inflammasome priming and these metabolic features. In advanced atherosclerotic plaques, loss of IKBKE and hematopoietic cell restoration altered plaque composition. These studies reveal a new role for hematopoietic IKBKE: to limit inflammasome priming and metaflammation.
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443
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Bieghs V, Trautwein C. Innate immune signaling and gut-liver interactions in non-alcoholic fatty liver disease. Hepatobiliary Surg Nutr 2015; 3:377-85. [PMID: 25568861 DOI: 10.3978/j.issn.2304-3881.2014.12.04] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Accepted: 12/05/2014] [Indexed: 12/11/2022]
Abstract
Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of the metabolic syndrome and covers a disease spectrum ranging from steatosis to inflammation, fibrosis, cirrhosis and hepatocellular carcinoma (HCC). The innate immune response in the liver plays an important role during NAFLD progression. In addition, changes in the intestinal microbial balance and bacterial translocation can further affect disease progression. Immune cells in the liver recognize cell damage or pathogen invasion with intracellular or surface-expressed pattern recognition receptors (PRRs), subsequently initiating signaling cascades that trigger the release of factors promoting the inflammatory response during NAFLD progression. Therefore, mechanisms by which cells of the immune system are activated and recruited into the liver and how these cells cause injury and stress are important for understanding the inflammatory response during NAFLD.
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Affiliation(s)
- Veerle Bieghs
- Department of Internal Medicine III, University Hospital, RWTH-Aachen, Germany
| | - Christian Trautwein
- Department of Internal Medicine III, University Hospital, RWTH-Aachen, Germany
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444
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Weiskirchen R, Tacke F. Cellular and molecular functions of hepatic stellate cells in inflammatory responses and liver immunology. Hepatobiliary Surg Nutr 2015; 3:344-63. [PMID: 25568859 DOI: 10.3978/j.issn.2304-3881.2014.11.03] [Citation(s) in RCA: 105] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Accepted: 10/17/2014] [Indexed: 12/11/2022]
Abstract
The liver is a central immunological organ. Liver resident macrophages, Kupffer cells (KC), but also sinusoidal endothelial cells, dendritic cells (DC) and other immune cells are involved in balancing immunity and tolerance against pathogens, commensals or food antigens. Hepatic stellate cells (HSCs) have been primarily characterized as the main effector cells in liver fibrosis, due to their capacity to transdifferentiate into collagen-producing myofibroblasts (MFB). More recent studies elucidated the fundamental role of HSC in liver immunology. HSC are not only the major storage site for dietary vitamin A (Vit A) (retinol, retinoic acid), which is essential for proper function of the immune system. This pericyte further represents a versatile source of many soluble immunological active factors including cytokines [e.g., interleukin 17 (IL-17)] and chemokines [C-C motif chemokine (ligand) 2 (CCL2)], may act as an antigen presenting cell (APC), and has autophagy activity. Additionally, it responds to many immunological triggers via toll-like receptors (TLR) (e.g., TLR4, TLR9) and transduces signals through pathways and mediators traditionally found in immune cells, including the Hedgehog (Hh) pathway or inflammasome activation. Overall, HSC promote rather immune-suppressive responses in homeostasis, like induction of regulatory T cells (Treg), T cell apoptosis (via B7-H1, PDL-1) or inhibition of cytotoxic CD8 T cells. In conditions of liver injury, HSC are important sensors of altered tissue integrity and initiators of innate immune cell activation. Vice versa, several immune cell subtypes interact directly or via soluble mediators with HSC. Such interactions include the mutual activation of HSC (towards MFB) and macrophages or pro-apoptotic signals from natural killer (NK), natural killer T (NKT) and gamma-delta T cells (γδ T-cells) on activated HSC. Current directions of research investigate the immune-modulating functions of HSC in the environment of liver tumors, cellular heterogeneity or interactions promoting HSC deactivation during resolution of liver fibrosis. Understanding the role of HSC as central regulators of liver immunology may lead to novel therapeutic strategies for chronic liver diseases.
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Affiliation(s)
- Ralf Weiskirchen
- 1 Institute of Molecular Pathobiochemistry, Experimental Gene Therapy and Clinical Chemistry, 2 Department of Internal Medicine III, RWTH University Hospital Aachen, Aachen, Germany
| | - Frank Tacke
- 1 Institute of Molecular Pathobiochemistry, Experimental Gene Therapy and Clinical Chemistry, 2 Department of Internal Medicine III, RWTH University Hospital Aachen, Aachen, Germany
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445
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Brandl K, Schnabl B. Is intestinal inflammation linking dysbiosis to gut barrier dysfunction during liver disease? Expert Rev Gastroenterol Hepatol 2015; 9:1069-76. [PMID: 26088524 PMCID: PMC4828034 DOI: 10.1586/17474124.2015.1057122] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Changes in the intestinal microbiota composition contribute to the pathogenesis of many disorders including gastrointestinal and liver diseases. Recent studies have broadened our understanding of the "gut-liver" axis. Dietary changes, other environmental and genetic factors can lead to alterations in the microbiota. Dysbiosis can further disrupt the integrity of the intestinal barrier leading to pathological bacterial translocation and the initiation of an inflammatory response in the liver. In this article, the authors dissect the different steps involved in disease pathogenesis to further refine approaches for the medical management of liver diseases. The authors will specifically discuss the role of dysbiosis in inducing intestinal inflammation and increasing intestinal permeability.
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Affiliation(s)
- Katharina Brandl
- Skaggs School of Pharmacy, University of California San Diego, 9500 Gilman Drive La Jolla, California 92093-0675, 858-822-6853,
| | - Bernd Schnabl
- Department of Medicine, VA San Diego Healthcare System, San Diego, CA,Department of Medicine, 9500 Gilman Drive, La Jolla, CA 92093-0063, University of California San Diego, 858-534-9484,
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446
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Abstract
Many lines of research have established a relationship between the gut microbiome and patients with liver disease. For example, patients with cirrhosis have increased bacteremia, increased blood levels of lipopolysaccharide, and increased intestinal permeability. Patients with cirrhosis have bacterial overgrowth in the small intestine. Selective intestinal decontamination with antibiotics is beneficial for patients with decompensated cirrhosis. In experimental models of chronic liver injury with fibrosis, several toll-like receptors (TLR) are required to make mice sensitive to liver fibrosis. The presumed ligand for the TLRs are bacterial products derived from the gut microbiome, and TLR knockout mice are resistant to liver inflammation and fibrosis. We and others have characterized the association between preclinical models of liver disease in mice with the microbial diversity in their gut microbiome. In each model, including intragastric alcohol, bile duct ligation, chronic carbon tetrachloride (CCl4), administration, and genetic obesity, there is a significant change in the gut microbiome from normal control mice. However, there is not a single clear bacterial strain or pattern that distinguish mice with liver injury from controlled mice. So how can the gut microbiota affect liver disease? We can identify at least 6 changes that would result in liver injury, inflammation, and/or fibrosis. These include: (1) changes in caloric yield of diet; (2) regulation of gut permeability to release bacterial products; (3) modulation of choline metabolism; (4) production of endogenous ethanol; (5) regulation of bile acid metabolism; and (6) regulation in lipid metabolism.
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447
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Hauff P, Gottwald U, Ocker M. Early to Phase II drugs currently under investigation for the treatment of liver fibrosis. Expert Opin Investig Drugs 2014; 24:309-27. [PMID: 25547844 DOI: 10.1517/13543784.2015.997874] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
INTRODUCTION Chronic liver diseases represent a high unmet medical need and are characterized by persistent inflammation, parenchymal damage and fibrotic remodeling, leading eventually to cirrhosis and hepatic failure. Besides the persisting high prevalence of chronic viral hepatitis B and C, the dramatic increase in nonalcoholic steatohepatitis is now considered to be a major pathophysiologic driver for fibrosis development and subsequently cirrhosis. Increasing evidence suggests that also liver cirrhosis can regress when treated adequately. AREAS COVERED Herein, the authors review the underlying pathophysiologic mechanisms leading to fibrotic remodeling in the liver. They also highlight the options for novel treatment strategies by using molecular targeted agents. EXPERT OPINION New in vitro and preclinical animal models, and the careful selection of patients with high disease dynamics for clinical studies, provide a sound basis for the clinical development of antifibrotic agents in humans. Surrogate parameters of liver function, inflammation, tissue remodeling and damage, as well as noninvasive imaging techniques, can be applied in clinical trials to provide fast readouts and novel and reliable endpoints for trial design, and provide an attractive regulatory environment for this emerging disease area.
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448
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Stojsavljević S, Gomerčić Palčić M, Virović Jukić L, Smirčić Duvnjak L, Duvnjak M. Adipokines and proinflammatory cytokines, the key mediators in the pathogenesis of nonalcoholic fatty liver disease. World J Gastroenterol 2014; 20:18070-18091. [PMID: 25561778 PMCID: PMC4277948 DOI: 10.3748/wjg.v20.i48.18070] [Citation(s) in RCA: 233] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Revised: 10/22/2014] [Accepted: 11/19/2014] [Indexed: 02/06/2023] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) is a condition in which excess fat accumulates in the liver of a patient with no history of alcohol abuse or other causes for secondary hepatic steatosis. The pathogenesis of NAFLD and nonalcoholic steatohepatitis (NASH) has not been fully elucidated. The “two-hit“ hypothesis is probably a too simplified model to elaborate complex pathogenetic events occurring in patients with NASH. It should be better regarded as a multiple step process, with accumulation of liver fat being the first step, followed by the development of necroinflammation and fibrosis. Adipose tissue, which has emerged as an endocrine organ with a key role in energy homeostasis, is responsive to both central and peripheral metabolic signals and is itself capable of secreting a number of proteins. These adipocyte-specific or enriched proteins, termed adipokines, have been shown to have a variety of local, peripheral, and central effects. In the current review, we explore the role of adipocytokines and proinflammatory cytokines in the pathogenesis of NAFLD. We particularly focus on adiponectin, leptin and ghrelin, with a brief mention of resistin, visfatin and retinol-binding protein 4 among adipokines, and tumor necrosis factor-α, interleukin (IL)-6, IL-1, and briefly IL-18 among proinflammatory cytokines. We update their role in NAFLD, as elucidated in experimental models and clinical practice.
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449
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Celardo I, Martins LM, Gandhi S. Unravelling mitochondrial pathways to Parkinson's disease. Br J Pharmacol 2014; 171:1943-57. [PMID: 24117181 PMCID: PMC3976614 DOI: 10.1111/bph.12433] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 09/09/2013] [Accepted: 09/17/2013] [Indexed: 02/06/2023] Open
Abstract
Mitochondria are essential for cellular function due to their role in ATP production, calcium homeostasis and apoptotic signalling. Neurons are heavily reliant on mitochondrial integrity for their complex signalling, plasticity and excitability properties, and to ensure cell survival over decades. The maintenance of a pool of healthy mitochondria that can meet the bioenergetic demands of a neuron, is therefore of critical importance; this is achieved by maintaining a careful balance between mitochondrial biogenesis, mitochondrial trafficking, mitochondrial dynamics and mitophagy. The molecular mechanisms that underlie these processes are gradually being elucidated. It is widely recognized that mitochondrial dysfunction occurs in many neurodegenerative diseases, including Parkinson's disease. Mitochondrial dysfunction in the form of reduced bioenergetic capacity, increased oxidative stress and reduced resistance to stress, is observed in several Parkinson's disease models. However, identification of the recessive genes implicated in Parkinson's disease has revealed a common pathway involving mitochondrial dynamics, transport, turnover and mitophagy. This body of work has led to the hypothesis that the homeostatic mechanisms that ensure a healthy mitochondrial pool are key to neuronal function and integrity. In this paradigm, impaired mitochondrial dynamics and clearance result in the accumulation of damaged and dysfunctional mitochondria, which may directly induce neuronal dysfunction and death. In this review, we consider the mechanisms by which mitochondrial dysfunction may lead to neurodegeneration. In particular, we focus on the mechanisms that underlie mitochondrial homeostasis, and discuss their importance in neuronal integrity and neurodegeneration in Parkinson's disease.
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450
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Zhang B, Roh YS, Liang S, Liu C, Naiki M, Masuda K, Seki E. Neurotropin suppresses inflammatory cytokine expression and cell death through suppression of NF-κB and JNK in hepatocytes. PLoS One 2014; 9:e114071. [PMID: 25470242 PMCID: PMC4254918 DOI: 10.1371/journal.pone.0114071] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 11/03/2014] [Indexed: 02/06/2023] Open
Abstract
Inflammatory response and cell death in hepatocytes are hallmarks of chronic liver disease, and, therefore, can be effective therapeutic targets. Neurotropin® (NTP) is a drug widely used in Japan and China to treat chronic pain. Although NTP has been demonstrated to suppress chronic pain through the descending pain inhibitory system, the action mechanism of NTP remains elusive. We hypothesize that NTP functions to suppress inflammatory pathways, thereby attenuating disease progression. In the present study, we investigated whether NTP suppresses inflammatory signaling and cell death pathways induced by interleukin-1β (IL-1β) and tumor necrosis factor-α (TNFα) in hepatocytes. NTP suppressed nuclear factor-κB (NF-κB) activation induced by IL-1β and TNFα assessed by using hepatocytes isolated from NF-κB-green fluorescent protein (GFP) reporter mice and an NF-κB-luciferase reporter system. The expression of NF-κB target genes, Il6, Nos2, Cxcl1, ccl5 and Cxcl2 induced by IL-1β and TNFα was suppressed after NTP treatment. We also found that NTP suppressed the JNK phosphorylation induced by IL-1β and TNFα. Because JNK activation contributes to hepatocyte death, we determined that NTP treatment suppressed hepatocyte death induced by IL-1β and TNFα in combination with actinomycin D. Taken together, our data demonstrate that NTP attenuates IL-1β and TNFα-mediated inflammatory cytokine expression and cell death in hepatocytes through the suppression of NF-κB and JNK. The results from the present study suggest that NTP may become a preventive or therapeutic strategy for alcoholic and non-alcoholic fatty liver disease in which NF-κB and JNK are thought to take part.
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Affiliation(s)
- Bi Zhang
- Department of Medicine, School of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Yoon Seok Roh
- Department of Medicine, School of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Shuang Liang
- Department of Medicine, School of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Cheng Liu
- Department of Medicine, School of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Mitsuru Naiki
- Department of Pharmacological Research, Institute of Bio-Active Science, Nippon Zoki Pharmaceutical Company Ltd., Kato, Hyogo, Japan
| | - Koichi Masuda
- Department of Orthopaedic Surgery, School of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Ekihiro Seki
- Department of Medicine, School of Medicine, University of California San Diego, La Jolla, California, United States of America
- Department of Surgery, School of Medicine, University of California San Diego, La Jolla, California, United States of America
- * E-mail:
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