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Abstract
Chronic liver diseases such as nonalcoholic fatty liver disease (NAFLD) or viral hepatitis are characterized by persistent inflammation and subsequent liver fibrosis. Liver fibrosis critically determines long-term morbidity (for example, cirrhosis or liver cancer) and mortality in NAFLD and nonalcoholic steatohepatitis (NASH). Inflammation represents the concerted response of various hepatic cell types to hepatocellular death and inflammatory signals, which are related to intrahepatic injury pathways or extrahepatic mediators from the gut-liver axis and the circulation. Single-cell technologies have revealed the heterogeneity of immune cell activation concerning disease states and the spatial organization within the liver, including resident and recruited macrophages, neutrophils as mediators of tissue repair, auto-aggressive features of T cells as well as various innate lymphoid cell and unconventional T cell populations. Inflammatory responses drive the activation of hepatic stellate cells (HSCs), and HSC subsets, in turn, modulate immune mechanisms via chemokines and cytokines or transdifferentiate into matrix-producing myofibroblasts. Current advances in understanding the pathogenesis of inflammation and fibrosis in the liver, mainly focused on NAFLD or NASH owing to the high unmet medical need, have led to the identification of several therapeutic targets. In this Review, we summarize the inflammatory mediators and cells in the diseased liver, fibrogenic pathways and their therapeutic implications.
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Affiliation(s)
- Linda Hammerich
- Department of Hepatology and Gastroenterology, Campus Virchow-Klinikum and Campus Charité Mitte, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Frank Tacke
- Department of Hepatology and Gastroenterology, Campus Virchow-Klinikum and Campus Charité Mitte, Charité - Universitätsmedizin Berlin, Berlin, Germany.
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Wu Y, Cao Y, Xu K, Zhu Y, Qiao Y, Wu Y, Chen J, Li C, Zeng R, Ge G. Dynamically remodeled hepatic extracellular matrix predicts prognosis of early-stage cirrhosis. Cell Death Dis 2021; 12:163. [PMID: 33558482 PMCID: PMC7870969 DOI: 10.1038/s41419-021-03443-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 01/12/2021] [Accepted: 01/15/2021] [Indexed: 12/17/2022]
Abstract
Liver cirrhosis remains major health problem. Despite the progress in diagnosis of asymptomatic early-stage cirrhosis, prognostic biomarkers are needed to identify cirrhotic patients at high risk developing advanced stage disease. Liver cirrhosis is the result of deregulated wound healing and is featured by aberrant extracellular matrix (ECM) remodeling. However, it is not comprehensively understood how ECM is dynamically remodeled in the progressive development of liver cirrhosis. It is yet unknown whether ECM signature is of predictive value in determining prognosis of early-stage liver cirrhosis. In this study, we systematically analyzed proteomics of decellularized hepatic matrix and identified four unique clusters of ECM proteins at tissue damage/inflammation, transitional ECM remodeling or fibrogenesis stage in carbon tetrachloride-induced liver fibrosis. In particular, basement membrane (BM) was heavily deposited at the fibrogenesis stage. BM component minor type IV collagen α5 chain expression was increased in activated hepatic stellate cells. Knockout of minor type IV collagen α5 chain ameliorated liver fibrosis by hampering hepatic stellate cell activation and promoting hepatocyte proliferation. ECM signatures were differentially enriched in the biopsies of good and poor prognosis early-stage liver cirrhosis patients. Clusters of ECM proteins responsible for homeostatic remodeling and tissue fibrogenesis, as well as basement membrane signature were significantly associated with disease progression and patient survival. In particular, a 14-gene signature consisting of basement membrane proteins is potent in predicting disease progression and patient survival. Thus, the ECM signatures are potential prognostic biomarkers to identify cirrhotic patients at high risk developing advanced stage disease.
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Affiliation(s)
- Yuexin Wu
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, 200031, Shanghai, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Yuyan Cao
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, 200031, Shanghai, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Keren Xu
- University of Chinese Academy of Sciences, 100049, Beijing, China
- CAS Key Laboratory of Systems Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, 200031, Shanghai, China
| | - Yue Zhu
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, 200031, Shanghai, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Yuemei Qiao
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, 200031, Shanghai, China
| | - Yanjun Wu
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, 200031, Shanghai, China
| | - Jianfeng Chen
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, 200031, Shanghai, China
- School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, 310024, Hangzhou, China
| | - Chen Li
- CAS Key Laboratory of Systems Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, 200031, Shanghai, China.
- Center for Single-Cell Omics, School of Public Health, Shanghai Jiao Tong University School of Medicine, 200025, Shanghai, China.
| | - Rong Zeng
- CAS Key Laboratory of Systems Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, 200031, Shanghai, China.
- CAS Key Laboratory of Systems Biology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, 310024, Hangzhou, China.
- School of Life Science and Technology, Shanghai Tech University, 201210, Shanghai, China.
| | - Gaoxiang Ge
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, 200031, Shanghai, China.
- School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, 310024, Hangzhou, China.
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McQuitty CE, Williams R, Chokshi S, Urbani L. Immunomodulatory Role of the Extracellular Matrix Within the Liver Disease Microenvironment. Front Immunol 2020; 11:574276. [PMID: 33262757 PMCID: PMC7686550 DOI: 10.3389/fimmu.2020.574276] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 10/14/2020] [Indexed: 12/12/2022] Open
Abstract
Chronic liver disease when accompanied by underlying fibrosis, is characterized by an accumulation of extracellular matrix (ECM) proteins and chronic inflammation. Although traditionally considered as a passive and largely architectural structure, the ECM is now being recognized as a source of potent damage-associated molecular pattern (DAMP)s with immune-active peptides and domains. In parallel, the ECM anchors a range of cytokines, chemokines and growth factors, all of which are capable of modulating immune responses. A growing body of evidence shows that ECM proteins themselves are capable of modulating immunity either directly via ligation with immune cell receptors including integrins and TLRs, or indirectly through release of immunoactive molecules such as cytokines which are stored within the ECM structure. Notably, ECM deposition and remodeling during injury and fibrosis can result in release or formation of ECM-DAMPs within the tissue, which can promote local inflammatory immune response and chemotactic immune cell recruitment and inflammation. It is well described that the ECM and immune response are interlinked and mutually participate in driving fibrosis, although their precise interactions in the context of chronic liver disease are poorly understood. This review aims to describe the known pro-/anti-inflammatory and fibrogenic properties of ECM proteins and DAMPs, with particular reference to the immunomodulatory properties of the ECM in the context of chronic liver disease. Finally, we discuss the importance of developing novel biotechnological platforms based on decellularized ECM-scaffolds, which provide opportunities to directly explore liver ECM-immune cell interactions in greater detail.
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Affiliation(s)
- Claire E. McQuitty
- Institute of Hepatology, Foundation for Liver Research, London, United Kingdom
- Faculty of Life Sciences & Medicine, King’s College London, London, United Kingdom
| | - Roger Williams
- Institute of Hepatology, Foundation for Liver Research, London, United Kingdom
- Faculty of Life Sciences & Medicine, King’s College London, London, United Kingdom
| | - Shilpa Chokshi
- Institute of Hepatology, Foundation for Liver Research, London, United Kingdom
- Faculty of Life Sciences & Medicine, King’s College London, London, United Kingdom
| | - Luca Urbani
- Institute of Hepatology, Foundation for Liver Research, London, United Kingdom
- Faculty of Life Sciences & Medicine, King’s College London, London, United Kingdom
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Meurer SK, Karsdal MA, Weiskirchen R. Advances in the clinical use of collagen as biomarker of liver fibrosis. Expert Rev Mol Diagn 2020; 20:947-969. [PMID: 32865433 DOI: 10.1080/14737159.2020.1814746] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
INTRODUCTION Hepatic fibrosis is the excessive synthesis and deposition of extracellular matrix including collagen in the tissue. Chronic liver insult leads to progressive parenchymal damage, portal hypertension, and cirrhosis. Determination of hepatic collagen by invasive liver biopsy is the gold standard to estimate severity and stage of fibrosis. However, this procedure is associated with pain, carries the risk of infection and bleeding, and is afflicted with a high degree of sampling error. Therefore, there is urgent need for serological collagen-derived markers to assess collagen synthesis/turnover. AREAS COVERED Biochemical properties of collagens, cellular sources of hepatic collagen synthesis, and regulatory aspects in collagen expression. Markers are discussed suitable to estimate hepatic collagen synthesis and/or turnover. Discussed studies were identified through a PubMed search done in May 2020 and the authors' topic knowledge. EXPERT OPINION Hepatic fibrosis is mainly characterized by accumulation of collagen-rich scar tissue. Although traditionally performed liver biopsy is still standard in estimating hepatic fibrosis, there is evidence that noninvasive diagnostic scores and collagen-derived neo-epitopes provide clinical useful information. These noninvasive tests are less expensive than liver biopsy, better tolerated, safer, and more acceptable to patients. Therefore, these tests will lead to dramatic changes in diagnosis.
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Affiliation(s)
- Steffen K Meurer
- Institute of Molecular Pathobiochemistry, Experimental Gene Therapy and Clinical Chemistry (IFMPEGKC), RWTH University Hospital Aachen , Aachen, Germany
| | - Morten A Karsdal
- Nordic Bioscience, Fibrosis Biomarkers and Research , Herlev, Denmark
| | - Ralf Weiskirchen
- Institute of Molecular Pathobiochemistry, Experimental Gene Therapy and Clinical Chemistry (IFMPEGKC), RWTH University Hospital Aachen , Aachen, Germany
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Arteel GE, Naba A. The liver matrisome - looking beyond collagens. JHEP Rep 2020; 2:100115. [PMID: 32637906 PMCID: PMC7330160 DOI: 10.1016/j.jhepr.2020.100115] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 03/17/2020] [Accepted: 03/22/2020] [Indexed: 02/07/2023] Open
Abstract
The extracellular matrix (ECM) is a diverse microenvironment that maintains bidirectional communication with surrounding cells to regulate cell and tissue homeostasis. The classical definition of the ECM has more recently been extended to include non-fibrillar proteins that either interact or are structurally affiliated with the ECM, termed the 'matrisome.' In addition to providing the structure and architectural support for cells and tissue, the matrisome serves as a reservoir for growth factors and cytokines, as well as a signaling hub via which cells can communicate with their environment and vice-versa. The matrisome is a master regulator of tissue homeostasis and organ function, which can dynamically and appropriately respond to any stress or injury. Failure to properly regulate these responses can lead to changes in the matrisome that are maladaptive. Hepatic fibrosis is a canonical example of ECM dyshomeostasis, leading to accumulation of predominantly collagenous ECM; indeed, hepatic fibrosis is considered almost synonymous with collagen accumulation. However, the qualitative and quantitative alterations of the hepatic matrisome during fibrosis are much more diverse than simple accumulation of collagens and occur long before fibrosis is histologically detected. A deeper understanding of the hepatic matrisome and its response to injury could yield new mechanistic insights into disease progression and regression, as well as potentially identify new biomarkers for both. In this review, we discuss the role of the ECM in liver diseases and look at new "omic" approaches to study this compartment.
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Key Words
- AUROC, area under the receiver operating characteristic curve
- CCl4, carbon tetrachloride
- ECM
- ECM, extracellular matrix
- Extracellular matrix
- Fibrosis
- HCC, hepatocellular carcinoma
- Liver disease
- MMP, matrix metalloproteinase
- NAFLD, non-alcoholic fatty liver disease
- NPV, negative predictive value
- POSTN, periostin
- PPV, positive predictive values
- Proteomics
- Regeneration
- TGFβ, transforming growth factor beta
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Affiliation(s)
- Gavin E. Arteel
- Division of Gastroenterology, Hepatology and Nutrition, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Pittsburgh Liver Research Center, Pittsburgh, PA, USA
| | - Alexandra Naba
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL, USA
- University of Illinois Cancer Center, Chicago, IL, USA
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Massey VL, Dolin CE, Poole LG, Hudson SV, Siow DL, Brock GN, Merchant ML, Wilkey DW, Arteel GE. The hepatic "matrisome" responds dynamically to injury: Characterization of transitional changes to the extracellular matrix in mice. Hepatology 2017; 65:969-982. [PMID: 28035785 PMCID: PMC5319876 DOI: 10.1002/hep.28918] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Revised: 09/14/2016] [Accepted: 10/16/2016] [Indexed: 12/13/2022]
Abstract
UNLABELLED The extracellular matrix (ECM) consists of diverse components that work bidirectionally with surrounding cells to create a responsive microenvironment. In some contexts (e.g., hepatic fibrosis), changes to the ECM are well recognized and understood. However, it is becoming increasingly accepted that the hepatic ECM proteome (i.e., matrisome) responds dynamically to stress well before fibrosis. The term "transitional tissue remodeling" describes qualitative and quantitative ECM changes in response to injury that do not alter the overall architecture of the organ; these changes in ECM may contribute to early disease initiation and/or progression. The nature and magnitude of these changes to the ECM in liver injury are poorly understood. The goals of this work were to validate analysis of the ECM proteome and compare the impact of 6 weeks of ethanol diet and/or acute lipopolysaccharide (LPS). Liver sections were processed in a series of increasingly rigorous extraction buffers to separate proteins by solubility. Extracted proteins were identified using liquid chromatography/tandem mass spectrometry (LC-MS/MS). Both ethanol and LPS dramatically increased the number of matrisome proteins ∼25%. The enhancement of LPS-induced liver damage by ethanol preexposure was associated with unique protein changes. CONCLUSION An extraction method to enrich the hepatic ECM was characterized. The results demonstrate that the hepatic matrisome responds dynamically to both acute (LPS) and chronic (ethanol) stresses, long before more-dramatic fibrotic changes to the liver occur. The changes to the mastrisome may contribute, at least in part, to the pathological responses to these stresses. It is also interesting that several ECM proteins responded similarly to both stresses, suggesting a common mechanism in both models. Nevertheless, there were responses that were unique to the individual and combined exposures. (Hepatology 2017;65:969-982).
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Affiliation(s)
- Veronica L. Massey
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY,University of Louisville Alcohol Research Center, Louisville, KY
| | - Christine E. Dolin
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY,University of Louisville Alcohol Research Center, Louisville, KY
| | - Lauren G. Poole
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY,University of Louisville Alcohol Research Center, Louisville, KY
| | - Shanice V. Hudson
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY,University of Louisville Alcohol Research Center, Louisville, KY
| | - Deanna L. Siow
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY,University of Louisville Alcohol Research Center, Louisville, KY
| | - Guy N. Brock
- Department of Bioinformatics and Biostatistics, University of Louisville Health Sciences Center, Louisville, KY
| | - Michael L. Merchant
- University of Louisville Alcohol Research Center, Louisville, KY,Department of Medicine, University of Louisville Health Sciences Center, Louisville, KY
| | - Daniel W. Wilkey
- University of Louisville Alcohol Research Center, Louisville, KY,Department of Medicine, University of Louisville Health Sciences Center, Louisville, KY
| | - Gavin E. Arteel
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY,University of Louisville Alcohol Research Center, Louisville, KY
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Transitional Remodeling of the Hepatic Extracellular Matrix in Alcohol-Induced Liver Injury. BIOMED RESEARCH INTERNATIONAL 2016; 2016:3162670. [PMID: 27843941 PMCID: PMC5098054 DOI: 10.1155/2016/3162670] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 09/27/2016] [Indexed: 12/19/2022]
Abstract
Alcohol consumption is a common custom worldwide, and the toxic effects of alcohol on several target organs are well understood. The liver is the primary site of alcohol metabolism and is therefore the major target of alcohol toxicity. Alcoholic liver disease is a spectrum of disease states, ranging from simple steatosis (fat accumulation), to inflammation, and eventually to fibrosis and cirrhosis if untreated. The fibrotic stage of ALD is primarily characterized by robust accumulation of extracellular matrix (ECM) proteins (collagens) which ultimately impairs the function of the organ. The role of the ECM in early stages of ALD is poorly understood, but recent research has demonstrated that a number of changes in the hepatic ECM in prefibrotic ALD not only are present, but may also contribute to disease progression. The purpose of this review is to summarize the established and proposed changes to the hepatic extracellular matrix (ECM) that may contribute to earlier stages of ALD development and to discuss potential mechanisms by which these changes may mediate the progression of the disease.
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Aziz-Seible RS, McVicker BL, Kharbanda KK, Casey CA. Cellular fibronectin stimulates hepatocytes to produce factors that promote alcohol-induced liver injury. World J Hepatol 2011; 3:45-55. [PMID: 21423914 PMCID: PMC3060416 DOI: 10.4254/wjh.v3.i2.45] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Revised: 12/29/2010] [Accepted: 11/06/2010] [Indexed: 02/06/2023] Open
Abstract
AIM To examine the consequences of cellular fibronectin (cFn) accumulation during alcohol-induced injury, and investigate whether increased cFn could have an effect on hepatocytes (HCs) by producing factors that could contribute to alcohol-induced liver injury. METHODS HCs were isolated from rats fed a control or ethanol liquid diet for four to six weeks. Exogenous cFn (up to 7.5 μg/mL) was added to cells cultured for 20 h, and viability (lactate dehydrogenase,LDH), apoptosis (caspase activity) and secretion of proinflammatory cytokines (tumor necrosis factor alpha, TNF-α and interleukin 6 IL-6), matrix metalloproteinases (MMPs) and their inhibitors (tissue inhibitors of metalloproteinases, TIMPs) was determined. Degradation of iodinated cFn was determined over a 3 h time period in the preparations. RESULTS cFn degradation is impaired in HCs isolated from ethanol-fed animals, leading to its accumulation in the matrix. Addition of exogenous cFn did not affect viability of HCs from control or ethanol-fed animals, and apoptosis was affected only at the higher concentration. Secretion of MMPs, TIMPs, TNF-α and IL-6, however, was increased by exogenously added cFn, with HCs from ethanol-fed animals showing increased susceptibility compared to the controls. CONCLUSION These results suggest that the elevated amounts of cFn observed in alcoholic liver injury can stimulate hepatocytes to produce factors which promote further tissue damage.
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Affiliation(s)
- Razia S Aziz-Seible
- Razia S Aziz-Seible, Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, 985870 Nebraska Medical Center, Omaha, NE 68198-5870, United States
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Aziz-Seible RS, Lee SM, Kharbanda KK, McVicker BL, Casey CA. Ethanol feeding potentiates the pro-inflammatory response of Kupffer cells to cellular fibronectin. Alcohol Clin Exp Res 2011; 35:717-25. [PMID: 21223308 DOI: 10.1111/j.1530-0277.2010.01389.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
BACKGROUND Excessive alcohol consumption leads to the increased extracellular matrix deposition of cellular fibronectin (cFn) in the liver, which is also implicated as an initiating event in the fibrogenic process. We propose that cFn directly stimulates Kupffer cells (KCs), which are involved in the early response to tissue damage, to produce factors that enhance the progression of alcohol-induced liver injury toward inflammation and fibrosis. METHOD KCs were isolated from rats fed a control or ethanol liquid diet for 4 to 6 weeks. The effect of exogenous cFn on KC viability and the secretion of the cytokines, TNF-α and IL-6, as well as of matrix remodeling factors, MMP-2 and TIMP-2, was determined after 20 hours of cell culture. RESULTS For KCs from both control- and ethanol-fed rats, viability remained unaffected by treatment with cFn. TNF-α and IL-6 production were increased in KCs exposed to cFn, with cells treated with 1, 2.5, and 5 μg/ml cFn secreting significantly higher levels of both cytokines compared with untreated cells (p < 0.05). Chronic ethanol administration resulted in a significantly enhanced secretion of IL-6 by KCs regardless of treatment with cFn. When MMP-2 protein and activity levels were measured by western blot analysis and gelatin zymography, respectively, we found that cFn stimulated a dramatic increase in both cells from ethanol- and control-fed rats, with the KCs from ethanol animals being more responsive to cFn at higher concentrations (p < 0.05). Significantly higher levels of TIMP-2, which inhibits both the activation and activity of MMP-2, were secreted by KCs treated with 5 μg/ml cFn. Correspondingly, more pro-MMP-2 than active-MMP-2 was detected. CONCLUSION Altogether, these results show that cFn stimulates KCs to produce factors that may enhance the promotion of tissue damage and that ethanol administration increases these responses.
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Affiliation(s)
- Razia S Aziz-Seible
- The Liver Study Unit, Department of Veterans Affairs Medical Center and the Departments of Internal Medicine and Biochemistry & Molecular Biology, University of Nebraska Medical Center, Omaha, Nebraska 68105, USA
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Aguilar RP, Genta S, Oliveros L, Anzulovich A, Giménez MS, Sánchez SS. Vitamin A deficiency injures liver parenchyma and alters the expression of hepatic extracellular matrix. J Appl Toxicol 2009; 29:214-22. [PMID: 18989869 DOI: 10.1002/jat.1399] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Vitamin A is an essential lipid-soluble nutrient that is crucial for morphogenesis and adult tissue maintenance. The retinoid homeostasis in the liver depends on a regular supply of vitamin A from an adequate dietary intake to preserve the normal organ structure and functions. This study focuses on the effect of vitamin A deficiency on the morphology and extracellular proteins expression of the liver in adult Wistar rats. Animals were fed with a normal (control group) or deficient vitamin A diet for 3 months. At the end of the experimental period, histological examination of the livers under light and electron microscopy revealed that vitamin A deficiency produced a loss of hepatocyte cord disposition with an irregular parenchymal organization. Abundant fat droplets were present in the cytoplasm of the hepatocytes. Elongated myofibroblastic-like cells with an irregular cytoplasmic process and without lipid droplets could be seen at the perisinusoidal space, where an elevated intensity of alpha smooth muscle actin (alpha-SMA) was observed. These results suggest that an activation of hepatic stellate cells (HSCs) occurred. Moreover, immunochemical methods revealed that vitamin A deficiency led to an increased expression of hepatic fibronectin, laminin and collagen type IV. We propose that vitamin A deprivation caused liver injury and that HSCs underwent a process of activation in which they produced alpha-SMA and synthesized extracellular components. These changes may be a factor predisposing to liver fibrosis. In consequence, vitamin A deprivation could affect human and animal health.
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Affiliation(s)
- Rossana Pérez Aguilar
- Departamento de Biología del Desarrollo, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) y Universidad Nacional de Tucumán, 4000 San Miguel de Tucumán, Argentina.
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Abstract
Alcoholic fatty liver is a potentially pathologic condition which can progress to steatohepatitis, fibrosis, and cirrhosis if alcohol consumption is continued. Alcohol exposure may induce fatty liver by increasing NADH/NAD(+) ratio, increasing sterol regulatory element-binding protein-1 (SREBP-1) activity, decreasing peroxisome proliferator-activated receptor-alpha (PPAR-alpha) activity, and increasing complement C3 hepatic levels. Alcohol may increase SREBP-1 activity by decreasing the activities of AMP-activated protein kinase and sirtuin-1. Tumor necrosis factor-alpha (TNF-alpha) produced in response to alcohol exposure may cause fatty liver by up-regulating SREBP-1 activity, whereas betaine and pioglitazone may attenuate fatty liver by down-regulating SREBP-1 activity. PPAR-alpha agonists have potentials to attenuate alcoholic fatty liver. Adiponectin and interleukin-6 may attenuate alcoholic fatty liver by up-regulating PPAR-alpha and insulin signaling pathways while down-regulating SREBP-1 activity and suppressing TNF-alpha production. Recent studies show that paracrine activation of hepatic cannabinoid receptor 1 by hepatic stellate cell-derived endocannabinoids also contributes to the development of alcoholic fatty liver. Furthermore, oxidative modifications and inactivation of the enzymes involved in the mitochondrial and/or peroxisomal beta-oxidation of fatty acids could contribute to fat accumulation in the liver.
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Affiliation(s)
- Vishnudutt Purohit
- Division of Metabolism and Health Effects, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, 5635 Fishers Lane, Bethesda, MD 20892, USA.
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Dodig M, Ogunwale B, Dasarathy S, Li M, Wang B, McCullough AJ. Differences in regulation of type I collagen synthesis in primary and passaged hepatic stellate cell cultures: the role of alpha5beta1-integrin. Am J Physiol Gastrointest Liver Physiol 2007; 293:G154-64. [PMID: 17510195 DOI: 10.1152/ajpgi.00432.2006] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Hepatic stellate cells (HSC) differ in their phenotype depending on the initiation and progression of their activation. Our hypothesis was that different mechanisms govern type I collagen synthesis depending on stage of HSC activation. We investigated the role of alpha(5)beta(1)-integrin as a regulator of type I collagen gene COL1A1 expression in primary and passaged HSC cultures using transgenic mouse containing type I collagen gene COL1A1 promoter linked to the chloramphenicol acetyltransferase (CAT) reporter gene. The alpha(5)beta(1) protein levels increased during the activation and were highest in day 6 primary cultures but decreased in passaged HSC. CAT activity, reflecting COL1A1 expression, was upregulated by alpha(5)beta(1)-integrin. Inhibition of alpha(5)beta(1)-integrin by echistatin and blocking antibody resulted in reduced transgene activity only in early primary cultures (compared with the control, 53.3 +/- 12% echistatin and 58.8 +/- 7% blocking antibody, respectively, P < 0.05). Treatment of passaged HSC with either echistatin or blocking antibody had no effect. Fibronectin, an alpha(5)beta(1)-integrin ligand, increased transgene activity in primary (210 +/- 33%, P < 0.05) but not in passaged HSC cultures (119 +/- 8%). This alpha(5)beta(1)-integrin effect appears to be at least in part mediated by CCAAT enhancer binding protein-beta (C/EBPbeta), because fibronectin increased and alpha(5)-gene silencing by small interfering RNA decreased C/EBPbeta levels. In addition, C/EBPbeta knockout mice showed reduced type I collagen synthesis compared with wild-type littermates. Therefore alpha(5)beta(1)-integrin is an important regulator of type I collagen production in early primary HSC cultures but appears to have no direct role once the HSC are fully activated.
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Affiliation(s)
- Milan Dodig
- Department of Gastroenterology and Hepatology, Cleveland Clinic and Cleveland Clinic Lerner College of Medicine, 9500 Euclid Avenue, Cleveland, OH 44195, USA.
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Roman J, Ritzenthaler JD, Bechara R, Brown LA, Guidot D. Ethanol stimulates the expression of fibronectin in lung fibroblasts via kinase-dependent signals that activate CREB. Am J Physiol Lung Cell Mol Physiol 2005; 288:L975-87. [PMID: 15653713 DOI: 10.1152/ajplung.00003.2004] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Ethanol renders the lung susceptible to acute lung injury in the setting of insults such as sepsis. The mechanisms mediating this effect are unknown, but activation of tissue remodeling is considered key to this process. We found that chronic ethanol ingestion in rats increased the expression of fibronectin, a matrix glycoprotein implicated in acute lung injury. In cultured NIH/3T3 cells and in primary rat and mouse lung fibroblasts, ethanol induced fibronectin mRNA and protein expression in a dose- and time-dependent fashion. The effect of ethanol was prevented by inhibitors of protein kinase C and mitogen-activated protein kinases and was associated with the phosphorylation and increased DNA binding of the transcription factor cAMP response element binding protein, followed by increased transcription of the fibronectin gene. Fibroblasts were found to express alpha(7) nicotinic acetylcholine receptor (nAChR), and ethanol induction of fibronectin was abolished by alpha-bungarotoxin and methyllcaconitine, inhibitors of alpha(7) nAChRs. However, ethanol was able to induce fibronectin mRNA and protein in primary lung fibroblasts isolated from alpha(7) nAChR knockout mice. The ethanol-induced fibronectin response was dependent on ethanol metabolism since 4-methylpyrazole, an inhibitor of alcohol dehydrogenase, abolished the effect and acetaldehyde induced it. These observations suggest that ethanol or ethanol metabolites stimulate lung fibroblasts to produce fibronectin by inducing specific signals transmitted via nAChRs independent of the alpha(7-)subunit, and this might represent a mechanism by which ethanol renders the lung susceptible to acute lung injury.
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Affiliation(s)
- Jesse Roman
- Division of Pulmonary, Allergy, and Critical Care Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA.
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Purohit V, Russo D, Coates PM. Role of fatty liver, dietary fatty acid supplements, and obesity in the progression of alcoholic liver disease: introduction and summary of the symposium. Alcohol 2004; 34:3-8. [PMID: 15670659 DOI: 10.1016/j.alcohol.2004.06.008] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2004] [Accepted: 06/09/2004] [Indexed: 02/07/2023]
Abstract
Alcoholic liver disease is a major cause of illness and death in the United States. In the initial stages of the disease, fat accumulation in hepatocytes leads to the development of fatty liver (steatosis), which is a reversible condition. If alcohol consumption is continued, steatosis may progress to hepatitis and fibrosis, which may lead to liver cirrhosis. Alcoholic fatty liver has long been considered benign; however, increasing evidence supports the idea that it is a pathologic condition. Blunting of the accumulation of fat within the liver during alcohol consumption may block or delay the progression of fatty liver to hepatitis and fibrosis. To achieve this goal, it is important to understand the underlying biochemical and molecular mechanisms by which chronic alcohol consumption leads to fat accumulation in the liver and fatty liver progresses to hepatitis and fibrosis. In addition to alcohol consumption, dietary fatty acids and obesity have been shown to affect the degree of fat accumulation within the liver. Again, it is important to know how these factors modulate the progression of alcoholic liver disease. The National Institute on Alcohol Abuse and Alcoholism and the Office of Dietary Supplements, National Institutes of Health, sponsored a symposium on "Role of Fatty Liver, Dietary Fatty Acid Supplements, and Obesity in the Progression of Alcoholic Liver Disease" in Bethesda, Maryland, USA, October 2003. The following is a summary of the symposium. Alcoholic fatty liver is a pathologic condition that may predispose the liver to further injury (hepatitis and fibrosis) by cytochrome P450 2E1 induction, free radical generation, lipid peroxidation, nuclear factor-kappa B activation, and increased transcription of proinflammatory mediators, including tumor necrosis factor-alpha. Increased acetaldehyde production and lipopolysaccharide-induced Kupffer cell activation may further exacerbate liver injury. Acetaldehyde may promote hepatic fat accumulation by impairing the ability of peroxisome proliferator-activated receptor alpha to bind DNA, and by increasing the synthesis of sterol regulatory binding protein-1. Unsaturated fatty acids (corn oil, fish oil) exacerbate alcoholic liver injury by accentuating oxidative stress, whereas saturated fatty acids are protective. Polyenylphosphatidylcholine may prevent liver injury by down-regulating cytochrome P450 2E1 activity, attenuating oxidative stress, reducing the number of activated hepatic stellate cells, and up-regulating collagenase activity. Nonalcoholic steatohepatitis may develop through several mechanisms, such as oxidative stress, mitochondrial dysfunction and associated impaired fat metabolism, dysregulated cytokine metabolism, insulin resistance, and altered methionine/S-adenosylmethionine/homocysteine metabolism. Obesity (adipose tissue) may contribute to the development of alcoholic liver disease by generating free radicals, increasing tumor necrosis factor-alpha production, inducing insulin resistance, and producing fibrogenic agents, such as angiotensin II, norepinephrine, neuropeptide Y, and leptin. Finally, alcoholic fatty liver transplant failure may be linked to oxidative stress. In vitro treatment of fatty livers with interleukin-6 may render allografts safer for clinical transplantation.
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Affiliation(s)
- Vishnudutt Purohit
- Division of Metabolism and Health Effects, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, 5635 Fishers Lane, Room 2035, Bethesda, MD 20892-9304, USA.
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Guidot DM, Roman J. Chronic ethanol ingestion increases susceptibility to acute lung injury: role of oxidative stress and tissue remodeling. Chest 2002; 122:309S-314S. [PMID: 12475807 DOI: 10.1378/chest.122.6_suppl.309s] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Clinical studies have demonstrated that chronic alcohol abuse is an independent outcome variable in acute lung injury. The Emory Center for the Study of Acute Lung Injury is determining the mechanisms by which ethanol increases susceptibility to acute lung injury. We developed a rat model of chronic ethanol ingestion and demonstrated that ethanol predisposes rats to edematous lung injury elicited by endotoxemia or sepsis. Chronic ethanol ingestion in rats led to decreased levels of glutathione, an important antioxidant in the lung, and this defect was associated with alterations in epithelial cell permeability, decreased alveolar liquid clearance, decreased cell viability, and decreased surfactant production. Chronic ethanol ingestion also led to the activation of lung tissue remodeling as demonstrated by the increased expression of profibrotic growth factors, matrix components, and metalloproteases. In cultured fibroblasts, the induction of the matrix glycoprotein fibronectin by ethanol was mediated via nicotinic acetylcholine receptor-dependent signal transduction. We speculate that these alterations render the host susceptible to acute lung injury by diminishing the protective mechanisms of the lung and promoting exaggerated inflammatory and tissue repair responses elicited against injurious agents.
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Affiliation(s)
- David M Guidot
- Department of Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, Atlanta Veterans Affairs Medical Center, Emory University School of Medicine, Atlanta, GA, USA
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Kishore R, Hill JR, McMullen MR, Frenkel J, Nagy LE. ERK1/2 and Egr-1 contribute to increased TNF-alpha production in rat Kupffer cells after chronic ethanol feeding. Am J Physiol Gastrointest Liver Physiol 2002; 282:G6-15. [PMID: 11751152 DOI: 10.1152/ajpgi.00328.2001] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Activation of Kupffer cells by lipopolysaccharide (LPS) is a critical step in the pathogenesis of alcoholic liver disease. Kupffer cells isolated from rats fed ethanol in their diet for 4 wk accumulated 4.3-fold more tumor necrosis factor (TNF)-alpha in response to LPS compared with pair-fed rats. In contrast, LPS-stimulated interleukin (IL)-1 accumulation was 50% lower after ethanol feeding. LPS-stimulated TNF-alpha mRNA accumulation was twofold higher after ethanol feeding, whereas IL-1beta mRNA accumulation was blunted. To understand the mechanisms for this differential response, we investigated the effects of ethanol on LPS-dependent signal transduction. Chronic ethanol feeding increased LPS-stimulated extracellular receptor-activated kinases 1/2 (ERK1/2) activation. Activation of ERK1/2 was required for maximal increases in TNF-alpha and IL-1beta mRNA and was associated with increased binding of early growth response-1 (Egr-1) to the TNF-alpha promoter after ethanol feeding. In contrast, ethanol feeding completely abrogated activation of nuclear factor-kappaB DNA-binding activity by LPS and had no effect on AP-1 binding. Together, these data suggest that enhanced activation of ERK1/2 and Egr-1 contributes to increased TNF-alpha production after chronic ethanol feeding.
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Affiliation(s)
- Raj Kishore
- Department of Nutrition, Case Western Reserve University, Cleveland, Ohio 44106-4906, USA
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Ng VL, Sabla GE, Melin-Aldana H, Kelley-Loughnane N, Degen JL, Bezerra JA. Plasminogen deficiency results in poor clearance of non-fibrin matrix and persistent activation of hepatic stellate cells after an acute injury. J Hepatol 2001; 35:781-9. [PMID: 11738106 DOI: 10.1016/s0168-8278(01)00212-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
BACKGROUND/AIMS Plasminogen directs matrix proteolysis during liver repair. Based on the role of hepatic stellate cells (HSCs) on matrix production, we investigated whether plasminogen-driven matrix proteolysis modulates the phenotype of HSCs. METHODS Carbon tetrachloride was injected intraperitoneally into mice deficient in plasminogen, fibrinogen, or both, and to normal littermates, followed by determination of the phenotype of HSCs, matrix deposition, and apoptosis. RESULTS Activation of HSCs was restricted to the zone of injury and increased >ten-fold above baseline regardless of the plasminogen status 2 days after toxin. Thereafter, the number of activated HSCs decreased to baseline levels between 7 and 14 days in normal mice, but remained elevated in plasminogen-deficient livers approximately ten-fold above non-targeted littermates. Despite the zonal increase in activated HSCs, the total number of desmin-stained HSCs was similar along the lobule in both genotypes. No appreciable difference in apoptosis of perisinusoidal cells was found between genotypes; however, fibrillary material was present in the subsinusoidal space of Plg(0) livers. This fibrillary material was not fibrin, as demonstrated by similar findings in Plg(0)/Fib(0) mice, which accumulated fibronectin in injured areas. CONCLUSIONS Proteolytic clearance of non-fibrin matrix components by plasminogen must occur for HSCs to restore the quiescent phenotype during liver repair.
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Affiliation(s)
- V L Ng
- Divisions of Gastroenterology, Hepatology, and Nutrition, Children's Hospital Research Foundation and Department of Pediatrics, University of Cincinnati, Cincinnati, OH 45229-3039, USA
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Schaffert CS, Sorrell MF, Tuma DJ. Expression and Cytoskeletal Association of Integrin Subunits Is Selectively Increased in Rat Perivenous Hepatocytes After Chronic Ethanol Administration. Alcohol Clin Exp Res 2001. [DOI: 10.1111/j.1530-0277.2001.tb02186.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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