351
|
Nelson JE, Brunt EM, Kowdley KV. Lower serum hepcidin and greater parenchymal iron in nonalcoholic fatty liver disease patients with C282Y HFE mutations. Hepatology 2012; 56:1730-40. [PMID: 22611049 PMCID: PMC3462887 DOI: 10.1002/hep.25856] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Accepted: 05/08/2012] [Indexed: 12/12/2022]
Abstract
UNLABELLED Hepcidin regulation is linked to both iron and inflammatory signals and may influence iron loading in nonalcoholic steatohepatitis (NASH). The aim of this study was to examine the relationships among HFE genotype, serum hepcidin level, hepatic iron deposition, and histology in nonalcoholic fatty liver disease (NAFLD). Single-nucleotide polymorphism genotyping for C282Y (rs1800562) and H63D (rs1799945) HFE mutations was performed in 786 adult subjects in the NASH Clinical Research Network (CRN). Clinical, histologic, and laboratory data were compared using nonparametric statistics and multivariate logistic regression. NAFLD patients with C282Y, but not H63D mutations, had lower median serum hepcidin levels (57 versus 65 ng/mL; P = 0.01) and higher mean hepatocellular (HC) iron grades (0.59 versus 0.28; P < 0.001), compared to wild-type (WT) subjects. Subjects with hepatic iron deposition had higher serum hepcidin levels than subjects without iron for all HFE genotypes (P < 0.0001). Hepcidin levels were highest among patients with mixed HC/reticuloendothelial system cell (RES) iron deposition. H63D mutations were associated with higher steatosis grades and NAFLD activity scores (odds ratio [OR], ≥1.4; 95% confidence interval [CI]: >1.0, ≤2.5; P ≤ 0.041), compared to WT, but not with either HC or RES iron. NAFLD patients with C282Y mutations had less ballooning or NASH (OR, ≤0.62; 95% CI: >0.39, <0.94; P ≤ 0.024), compared to WT subjects. CONCLUSIONS The presence of C282Y mutations in patients with NAFLD is associated with greater HC iron deposition and decreased serum hepcidin levels, and there is a positive relationship between hepatic iron stores and serum hepcidin level across all HFE genotypes. These data suggest that body iron stores are the major determinant of hepcidin regulation in NAFLD, regardless of HFE genotype. A potential role for H63D mutations in NAFLD pathogenesis is possible through iron-independent mechanisms.
Collapse
|
352
|
Hartmann P, Chen WC, Schnabl B. The intestinal microbiome and the leaky gut as therapeutic targets in alcoholic liver disease. Front Physiol 2012; 3:402. [PMID: 23087650 PMCID: PMC3468817 DOI: 10.3389/fphys.2012.00402] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2012] [Accepted: 09/24/2012] [Indexed: 01/18/2023] Open
Abstract
Alcoholic liver disease (ALD) encompasses hepatic steatosis, which may progress to alcoholic hepatitis, fibrosis, and cirrhosis. It remains a leading cause of morbidity and mortality in the US and worldwide. The severity of liver disease correlates with plasma levels of bacterial products in patients, and experimental ALD depends on the level of gut derived bacterial products in rodents. Since intestinal decontamination and deficiency of bacterial product receptors or their downstream signaling molecules protect from alcohol-induced liver disease, bacterial translocation (BT), qualitative, and quantitative changes of the enteric microbiome are considered as being of fundamental importance in the pathogenesis of ALD. Recent enhancements in diagnostic technologies provide a better insight into these shifts. This review highlights vital events in ALD such as BT, the importance of Toll-like receptor (TLR) signaling, intestinal bacterial overgrowth (IBO), and changes in the intestinal microbiome. Furthermore, a treatment trial section of patients reviews possible future options of therapy for ALD modifying the enteric microbiome.
Collapse
|
353
|
Lee Y, Jee HJ, Noh H, Kang GH, Park J, Cho J, Cho JH, Ahn S, Lee C, Kim OH, Oh BC, Kim H. In vivo (1)H-MRS hepatic lipid profiling in nonalcoholic fatty liver disease: an animal study at 9.4 T. Magn Reson Med 2012; 70:620-9. [PMID: 23023916 DOI: 10.1002/mrm.24510] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Revised: 08/30/2012] [Accepted: 08/31/2012] [Indexed: 12/15/2022]
Abstract
The applicability of the in vivo proton magnetic resonance spectroscopy hepatic lipid profiling (MR-HLP) technique in nonalcoholic fatty liver disease was investigated. Using magnetic resonance spectroscopy, the relative fractions of diunsaturated (fdi), monounsaturated (fmono), and saturated (fsat) fatty acids as well as total hepatic lipid content were estimated in the livers of 8 control and 23 CCl4-treated rats at 9.4 T. The mean steatosis, necrosis, inflammation, and fibrosis scores of the treated group were all significantly higher than those of the control group (P < 0.01). There was a strong correlation between the histopathologic parameters and the MR-HLP parameters (r = 0.775, P < 0.01) where both steatosis and fibrosis are positively correlated with fmono and negatively correlated with fdi. Both necrosis and inflammation, however, were not correlated with any of the MR-HLP parameters. Hepatic lipid composition appears to be changed in association with the severity of steatosis and fibrosis in nonalcoholic fatty liver disease, and these changes can be depicted in vivo by using the MR-HLP method at 9.4 T. Thus, while it may not likely be that MR-HLP helps differentiate between steatohepatitis in its early stages and simple steatosis, these findings altogether are in support of potential applicability of in vivo MR-HLP at high field in nonalcoholic fatty liver disease.
Collapse
|
354
|
Weingarten TN, Mantilla CB, Swain JM, Kendrick ML, Oberhansley JM, Burcham RJ, Ribeiro TC, Watt KD, Schroeder DR, Narr BJ, Sprung J. Nonalcoholic steatohepatitis in bariatric patients with a diagnosis of obstructive sleep apnea. Obes Facts 2012; 5:587-96. [PMID: 22986647 PMCID: PMC6902219 DOI: 10.1159/000342677] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Accepted: 02/12/2012] [Indexed: 12/13/2022] Open
Abstract
OBJECTIVE To study a possible association between obstructive sleep apnea (OSA) severity, managed with noninvasive ventilation, and nonalcoholic steatohepatitis (NASH) in bariatric surgical patients. METHODS Medical records of 218 bariatric surgical patients who underwent liver biopsy were reviewed. OSA severity was determined from preoperative polysomnography (apnea-hypopnea index (AHI) ≤ 15 no/mild OSA vs. AHI ≥ 16 moderate/severe OSA). Patients diagnosed with OSA were prescribed noninvasive ventilation. Patients were categorized according to liver histopathology into 3 groups: (i) no liver disease or simple steatosis, (ii) mild NASH (steatosis with necroinflammation and mild fibrosis (stage 0-1)), and iii) advanced NASH (steatosis with necroinflammation and more advanced fibrosis (stage ≥ 2)). RESULTS 125 patients (57%) had no/mild OSA, and 93 (43%) had moderate/severe OSA. There was no difference in serum aminotransferases between patients by OSA severity classification. There was a high prevalence of hepatic histopathological abnormalities: 84% patients had steatosis, 57% had necroinflammation, 34% had fibrotic changes, and 14% had advanced NASH. There was no association between severity of NASH and severity of OSA. CONCLUSIONS There is no association between stage of steatohepatitis and OSA severity among morbidly obese patients managed with noninvasive ventilation.
Collapse
|
355
|
Kowdley KV, Belt P, Wilson LA, Yeh MM, Neuschwander-Tetri BA, Chalasani N, Sanyal AJ, Nelson JE. Serum ferritin is an independent predictor of histologic severity and advanced fibrosis in patients with nonalcoholic fatty liver disease. Hepatology 2012; 55:77-85. [PMID: 21953442 PMCID: PMC3245347 DOI: 10.1002/hep.24706] [Citation(s) in RCA: 358] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Accepted: 09/26/2011] [Indexed: 12/11/2022]
Abstract
UNLABELLED Serum ferritin (SF) levels are commonly elevated in patients with nonalcoholic fatty liver disease (NAFLD) because of systemic inflammation, increased iron stores, or both. The aim of this study was to examine the relationship between elevated SF and NAFLD severity. Demographic, clinical, histologic, laboratory, and anthropometric data were analyzed in 628 adult patients with NAFLD (age, ≥ 18 years) with biopsy-proven NAFLD and an SF measurement within 6 months of their liver biopsy. A threshold SF >1.5 × upper limit of normal (ULN) (i.e., >300 ng/mL in women and >450 ng/mL in men) was significantly associated with male sex, elevated serum alanine aminotransferase, aspartate aminotransferase, iron, transferrin-iron saturation, iron stain grade, and decreased platelets (P < 0.01). Histologic features of NAFLD were more severe among patients with SF >1.5 × ULN, including steatosis, fibrosis, hepatocellular ballooning, and diagnosis of NASH (P < 0.026). On multiple regression analysis, SF >1.5 × ULN was independently associated with advanced hepatic fibrosis (odds ratio [OR], 1.66; 95% confidence interval [CI], 1.05-2.62; P = 0.028) and increased NAFLD Activity Score (NAS) (OR, 1.99; 95% CI, 1.06-3.75; P = 0.033). CONCLUSIONS A SF >1.5 × ULN is associated with hepatic iron deposition, a diagnosis of NASH, and worsened histologic activity and is an independent predictor of advanced hepatic fibrosis among patients with NAFLD. Furthermore, elevated SF is independently associated with higher NAS, even among patients without hepatic iron deposition. We conclude that SF is useful to identify NAFLD patients at risk for NASH and advanced fibrosis.
Collapse
|
356
|
Cano A, Buqué X, Martínez-Uña M, Aurrekoetxea I, Menor A, García-Rodriguez JL, Lu SC, Martínez-Chantar ML, Mato JM, Ochoa B, Aspichueta P. Methionine adenosyltransferase 1A gene deletion disrupts hepatic very low-density lipoprotein assembly in mice. Hepatology 2011; 54:1975-86. [PMID: 21837751 PMCID: PMC3222787 DOI: 10.1002/hep.24607] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
UNLABELLED Very low-density lipoprotein (VLDL) secretion provides a mechanism to export triglycerides (TG) from the liver to peripheral tissues, maintaining lipid homeostasis. In nonalcoholic fatty liver disease (NAFLD), VLDL secretion disturbances are unclear. Methionine adenosyltransferase (MAT) is responsible for S-adenosylmethionine (SAMe) synthesis and MAT I and III are the products of the MAT1A gene. Deficient MAT I and III activities and SAMe content in the liver have been associated with NAFLD, but whether MAT1A is required for normal VLDL assembly remains unknown. We investigated the role of MAT1A on VLDL assembly in two metabolic contexts: in 3-month-old MAT1A-knockout mice (3-KO), with no signs of liver injury, and in 8-month-old MAT1A-knockout mice (8-KO), harboring nonalcoholic steatohepatitis. In 3-KO mouse liver, there is a potent effect of MAT1A deletion on lipid handling, decreasing mobilization of TG stores, TG secretion in VLDL and phosphatidylcholine synthesis via phosphatidylethanolamine N-methyltransferase. MAT1A deletion also increased VLDL-apolipoprotein B secretion, leading to small, lipid-poor VLDL particles. Administration of SAMe to 3-KO mice for 7 days recovered crucial altered processes in VLDL assembly and features of the secreted lipoproteins. The unfolded protein response was activated in 8-KO mouse liver, in which TG accumulated and the phosphatidylcholine-to-phosphatidylethanolamine ratio was reduced in the endoplasmic reticulum, whereas secretion of TG and apolipoprotein B in VLDL was increased and the VLDL physical characteristics resembled that in 3-KO mice. MAT1A deletion also altered plasma lipid homeostasis, with an increase in lipid transport in low-density lipoprotein subclasses and decrease in high-density lipoprotein subclasses. CONCLUSION MAT1A is required for normal VLDL assembly and plasma lipid homeostasis in mice. Impaired VLDL synthesis, mainly due to SAMe deficiency, contributes to NAFLD development in MAT1A-KO mice.
Collapse
|
357
|
Abstract
OBJECTIVE A review of the peri-operative risk associated with hepatic resection in patients with metabolic syndrome (MetS) and identification of measures for the improvement of cardiometabolic disturbances and liver-related mortality. BACKGROUND MetS and its hepatic manifestation non-alcoholic fatty liver disease (NAFLD) are associated with an increased operative mortality in spite of a significant improvement in peri-operative outcome after hepatic resection. METHODS A review of the English literature on MetS, liver resection and steatosis was performed from 1980 to 2011 using the MEDLINE and PubMed databases. RESULTS MetS is a predictor of NAFLD and patients with multiple metabolic risk factors may harbour non-alcoholic steatohepatitis (NASH) predictive of operative and cardiovascular mortality. Pre-operative diagnosis of unsuspected NASH with the selective use of a liver biopsy can modify the operative strategy by limiting the extent of hepatic resection, avoiding or altering the pre-operative chemotherapy regimen and the utilization of portal vein embolization. Thiazolidinediones are therapeutic for MetS and NASH and Vitamin E for active NASH; however, their utility in improving the peri-operative outcome after hepatic resection is unknown. A short-term regimen for weight loss improves post-operative patient and liver-related outcomes in patients with >30% steatosis. Cardiovascular disease associated with MetS or NAFLD should be managed aggressively. Peri-operative measures to minimize thrombotic events and acute renal injury secondary to the pro-inflammatory, prothrombotic state of MetS may further improve the outcome. CONCLUSION Potential candidates for hepatic resection should be screened for MetS as the pre-operative identification of NASH, short-term treatment of significant steatosis, cardiovascular risk assessment and optimization of each component of MetS may improve the peri-operative outcome in this high-risk subset of patients.
Collapse
|
358
|
Kamari Y, Shaish A, Vax E, Shemesh S, Kandel-Kfir M, Arbel Y, Olteanu S, Barshack I, Dotan S, Voronov E, Dinarello CA, Apte RN, Harats D. Lack of interleukin-1α or interleukin-1β inhibits transformation of steatosis to steatohepatitis and liver fibrosis in hypercholesterolemic mice. J Hepatol 2011; 55:1086-94. [PMID: 21354232 PMCID: PMC3210940 DOI: 10.1016/j.jhep.2011.01.048] [Citation(s) in RCA: 222] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2010] [Revised: 01/10/2011] [Accepted: 01/31/2011] [Indexed: 12/13/2022]
Abstract
BACKGROUND & AIMS The identification of the cellular and molecular pathways that mediate the development of non-alcoholic steatohepatitis is of crucial importance. Cytokines produced by liver-resident and infiltrating inflammatory cells, play a pivotal role in liver inflammation. The role of the proinflammatory cytokines IL-1α and IL-1β in steatohepatitis remains elusive. METHODS We employed IL-1α and IL-1β-deficient mice and transplanted marrow cells to study the role of liver-resident and bone marrow-derived IL-1 in steatosis and its progression to steatohepatitis. RESULTS Atherogenic diet-induced steatohepatitis in wild-type mice was associated with 16 and 4.6 fold-elevations in mRNA levels of hepatic IL-1α and IL-1β, respectively. In mice deficient in either IL-1α or IL-1β the transformation of steatosis to steatohepatitis and liver fibrosis was markedly reduced. This protective effect in IL-1α-deficient mice was noted despite increased liver cholesterol levels. Deficiency of IL-1α markedly reduced plasma serum amyloid A and steady-state levels of mRNA coding for inflammatory genes (P-selectin, CXCL1, IL-6, and TNFα) as well as pro-fibrotic genes (MMP-9 and Collagen) and particularly a 50% decrease in TGFβ levels (p = 0.004). IL-1α mRNA levels were two-folds lower in IL-1β-deficient mice, and IL-1β transcripts were three-folds lower in IL-1α-deficient compared to wild-type mice. Hepatic cell derived IL-1α rather than from recruited bone marrow-derived cells was required for steatohepatitis development. CONCLUSIONS These data demonstrate the critical role of IL-1α and IL-1β in the transformation of steatosis to steatohepatitis and liver fibrosis in hypercholesterolemic mice. Therefore, the potential of neutralizing IL-1α and/or IL-1β to inhibit the development of steatohepatitis should be explored.
Collapse
|
359
|
Abstract
Bariatric surgical procedures have become important therapeutic options for treatment of morbid obesity in both adults and adolescents co-morbidities of obesity such as glucose intolerance, type 2 diabetes (T2DM), metabolic syndrome, steatohepatitis, hyperlipidemia and cardiovascular disease. These co-morbidities of obesity have significant impacts on the overall quality of life of the individual and our society at large. Roux-en-Y gastric bypass (RYGB) and the relatively newer procedures of gastric banding (GB) and vertical sleeve gastrectomy (VSG) have proven to be efficacious in achieving rapid weight loss and reversing the comorbidities of obesity. Unfortunately, bariatric procedures are not without risks including micronutrient deficiency, failure to maintain lost weight, and mortality. Further, the resolution of T2DM has long been understood to precede weight loss, and this finding provides important clues about the physiologic underpinnings of the observation. In order to design more effective, safe, and widely available therapeutics for obesity, important and highly relevant questions need to be addressed regarding mechanisms behind the weight-loss-independent benefits of bariatric surgical procedures. This review will provide an overview of the molecular changes occurring across all biological systems after bariatric surgery including the changes in hepatic, adipocyte and gut derived signals after surgery. We will also discuss existing literature regarding the weight-loss-independent metabolic benefits including improvement in insulin sensitivity and central nervous system integration of these signals.
Collapse
|
360
|
Qu A, Taylor M, Xue X, Matsubara T, Metzger D, Chambon P, Gonzalez FJ, Shah YM. Hypoxia-inducible transcription factor 2α promotes steatohepatitis through augmenting lipid accumulation, inflammation, and fibrosis. Hepatology 2011; 54:472-83. [PMID: 21538443 PMCID: PMC3145012 DOI: 10.1002/hep.24400] [Citation(s) in RCA: 143] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Accepted: 04/17/2011] [Indexed: 12/11/2022]
Abstract
UNLABELLED Oxygen dynamics in the liver is a central signaling mediator controlling hepatic homeostasis, and dysregulation of cellular oxygen is associated with liver injury. Moreover, the transcription factor relaying changes in cellular oxygen levels, hypoxia-inducible factor (HIF), is critical in liver metabolism, and sustained increase in HIF signaling can lead to spontaneous steatosis, inflammation, and liver tumorigenesis. However, the direct responses and genetic networks regulated by HIFs in the liver are unclear. To help define the HIF signal-transduction pathway, an animal model of HIF overexpression was generated and characterized. In this model, overexpression was achieved by Von Hippel-Lindau (Vhl) disruption in a liver-specific temporal fashion. Acute disruption of Vhl induced hepatic lipid accumulation in an HIF-2α-dependent manner. In addition, HIF-2α activation rapidly increased liver inflammation and fibrosis, demonstrating that steatosis and inflammation are primary responses of the liver to hypoxia. To identify downstream effectors, a global microarray expression analysis was performed using livers lacking Vhl for 24 hours and 2 weeks, revealing a time-dependent effect of HIF on gene expression. Increase in genes involved in fatty acid synthesis were followed by an increase in fatty acid uptake-associated genes, and an inhibition of fatty acid β-oxidation. A rapid increase in proinflammatory cytokines and fibrogenic gene expression was also observed. In vivo chromatin immunoprecipitation assays revealed novel direct targets of HIF signaling that may contribute to hypoxia-mediated steatosis and inflammation. CONCLUSION These data suggest that HIF-2α is a critical mediator in the progression from clinically manageable steatosis to more severe steatohepatitis and liver cancer, and may be a potential therapeutic target.
Collapse
|
361
|
DeLeve LD, Jaeschke H, Kalra VK, Asahina K, Brenner DA, Tsukamoto H. 15th International Symposium on Cells of the Hepatic Sinusoid, 2010. Liver Int 2011; 31:762-72. [PMID: 21645207 PMCID: PMC4388239 DOI: 10.1111/j.1478-3231.2011.02527.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
This is a meeting report of the presentations given at the 15th International Symposium on Cells of the Hepatic Sinusoid, held in 2010. The areas covered include the contributions of the various liver cell populations to liver disease, molecular and cellular targets involved in steatohepatitis, hepatic fibrosis and cancer and regenerative medicine. In addition to a review of the science presented at the meeting, this report provides references to recent literature on the topics covered at the meeting.
Collapse
|
362
|
Abstract
The unfolded protein response (UPR) is an evolutionarily conserved cell signaling pathway that is activated to regulate protein synthesis and restore homeostatic equilibrium when the cell is stressed from increased client protein load or the accumulation of unfolded or malfolded proteins. Once activated, this signaling pathway can either result in the recovery of homeostasis or can activate a cascade of events that ultimately result in cell death. The UPR/endoplasmic reticulum (ER) stress response spectrum and its interplay with other cellular organelles play an important role in the pathogenesis of disease in secretory cells rich in ER, such as hepatocytes. Over the past 2 decades, the contribution of ER stress to various forms of liver diseases has been examined. Robust support for a contributing, as opposed to a secondary role, for ER stress response is seen in the nonalcoholic steatohepatitis, alcoholic liver disease, ischemia/reperfusion injury, and cholestatic models of liver disease. The exact direction of the cause and effect relationship between modes of cell injury and ER stress remains elusive. It is apparent that a complex interplay exists between ER stress response, conditions that promote it, and those that result from it. A vicious cycle in which ER stress promotes inflammation, cell injury, and steatosis and in which steatogenesis, inflammation, and cell injury aggravate ER stress seems to be at play. It is perhaps the nature of such a vicious cycle that is the key pathophysiologic concept. Therapeutic approaches aimed at interrupting the cycle may dampen the stress response and the ensuing injury.
Collapse
|
363
|
Macfarlane DP, Zou X, Andrew R, Morton NM, Livingstone DEW, Aucott RL, Nyirenda MJ, Iredale JP, Walker BR. Metabolic pathways promoting intrahepatic fatty acid accumulation in methionine and choline deficiency: implications for the pathogenesis of steatohepatitis. Am J Physiol Endocrinol Metab 2011; 300:E402-9. [PMID: 21119028 PMCID: PMC3043621 DOI: 10.1152/ajpendo.00331.2010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The pathological mechanisms that distinguish simple steatosis from steatohepatitis (or NASH, with consequent risk of cirrhosis and hepatocellular cancer) remain incompletely defined. Whereas both a methionine- and choline-deficient diet (MCDD) and a choline-deficient diet (CDD) lead to hepatic triglyceride accumulation, MCDD alone is associated with hepatic insulin resistance and inflammation (steatohepatitis). We used metabolic tracer techniques, including stable isotope ([¹³C₄]palmitate) dilution and mass isotopomer distribution analysis (MIDA) of [¹³C₂]acetate, to define differences in intrahepatic fatty acid metabolism that could explain the contrasting effect of MCDD and CDD on NASH in C57Bl6 mice. Compared with control-supplemented (CS) diet, liver triglyceride pool sizes were similarly elevated in CDD and MCDD groups (24.37 ± 2.4, 45.94 ± 3.9, and 43.30 ± 3.5 μmol/liver for CS, CDD, and MCDD, respectively), but intrahepatic neutrophil infiltration and plasma alanine aminotransferase (31 ± 3, 48 ± 4, 231 ± 79 U/l, P < 0.05) were elevated only in MCDD mice. However, despite loss of peripheral fat in MCDD mice, neither the rate of appearance of palmitate (27.2 ± 3.5, 26.3 ± 2.3, and 28.3 ± 3.5 μmol·kg⁻¹·min⁻¹) nor the contribution of circulating fatty acids to the liver triglyceride pool differed between groups. Unlike CDD, MCDD had a defect in hepatic triglyceride export that was confirmed using intravenous tyloxapol (142 ± 21, 122 ± 15, and 80 ± 7 mg·kg⁻¹·h⁻¹, P < 0.05). Moreover, hepatic de novo lipogenesis was significantly elevated in the MCDD group only (1.4 ± 0.3, 2.3 ± 0.4, and 3.4 ± 0.4 μmol/day, P < 0.01). These findings suggest that important alterations in hepatic fatty acid metabolism may promote the development of steatohepatitis. Similar mechanisms may predispose to hepatocyte damage in human NASH.
Collapse
|
364
|
Nelson JE, Wilson L, Brunt EM, Yeh MM, Kleiner DE, Unalp-Arida A, Kowdley KV. Relationship between the pattern of hepatic iron deposition and histological severity in nonalcoholic fatty liver disease. Hepatology 2011; 53:448-57. [PMID: 21274866 PMCID: PMC3058264 DOI: 10.1002/hep.24038] [Citation(s) in RCA: 229] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2010] [Accepted: 09/10/2010] [Indexed: 12/14/2022]
Abstract
UNLABELLED Previous studies examining the relationship between hepatic iron deposition and histological severity in nonalcoholic fatty liver disease (NAFLD) have been inconclusive. The goal of this study was to examine the relationship between hepatic iron deposition and liver histology in 849 patients enrolled in the Nonalcoholic Steatohepatitis Clinical Research Network. Hepatic iron staining was performed in a central laboratory, and the stains were scored for grade and cellular and parenchymal localization by a central pathology committee; the relationship between the grade and pattern of iron deposition and the clinical, laboratory, and histological variables was examined with univariate and multivariate analyses. Stainable hepatic iron was present in 293 of 849 patients (34.5%) in one of three histological patterns: a hepatocellular (HC) pattern [63/849 (7.4%)], a reticuloendothelial system (RES) cell pattern [91/849 (10.7%)], or a mixed RES/HC pattern [139/849 (16.4%)]. Patients with the RES iron-staining pattern were more likely to have advanced fibrosis compared to those with those with HC iron (P = 0.01). Patients with RES iron were also more likely to have advanced histological features such as fibrosis (P = 0.049), portal inflammation (P = 0.002), HC ballooning (P = 0.006), and definite nonalcoholic steatohepatitis (P = 0.007) compared to those with patients with HC or mixed iron patterns. The presence of RES iron (odds ratio = 1.60, 95% confidence interval = 1.10-2.33, P = 0.015) was independently associated with advanced hepatic fibrosis on multiple regression analysis after adjustments for age, gender, diabetes status, and body mass index. CONCLUSION The presence and pattern of hepatic iron deposition are associated with distinct histological features in patients with NAFLD and may have implications for pathophysiology and therapy.
Collapse
|
365
|
Abstract
In nonalcoholic fatty liver disease (NAFLD), depletion of hepatic antioxidants may contribute to the progression of steatosis to nonalcoholic steatohepatitis (NASH) by increasing oxidative stress that produces lipid peroxidation, inflammation, and fibrosis. We investigated whether depletion of glutathione (GSH) increases NASH-associated hepatic pathology in mice fed a diet deficient in methionine and choline (MCD diet). Wild-type (wt) mice and genetically GSH-deficient mice lacking the modifier subunit of glutamate cysteine ligase (Gclm null mice), the rate-limiting enzyme for de novo synthesis of GSH, were fed the MCD diet, a methionine/choline-sufficient diet, or standard chow for 21 days. We assessed NASH-associated hepatic pathology, including steatosis, fibrosis, inflammation, and hepatocyte ballooning, and used the NAFLD Scoring System to evaluate the extent of changes. We measured triglyceride levels, determined the level of lipid peroxidation products, and measured by qPCR the expression of mRNAs for several proteins associated with lipid metabolism, oxidative stress, and fibrosis. MCD-fed GSH-deficient Gclm null mice were to a large extent protected from MCD diet-induced excessive fat accumulation, hepatocyte injury, inflammation, and fibrosis. Compared with wt animals, MCD-fed Gclm null mice had much lower levels of F₂-isoprostanes, lower expression of acyl-CoA oxidase, carnitine palmitoyltransferase 1a, uncoupling protein-2, stearoyl-coenzyme A desaturase-1, transforming growth factor-β, and plasminogen activator inhibitor-1 mRNAs, and higher activity of catalase, indicative of low oxidative stress, inhibition of triglyceride synthesis, and lower expression of profibrotic proteins. Global gene analysis of hepatic RNA showed that compared with wt mice, the livers of Gclm null mice have a high capacity to metabolize endogenous and exogenous compounds, have lower levels of lipogenic proteins, and increased antioxidant activity. Thus, metabolic adaptations resulting from severe GSH deficiency seem to protect against the development of steatohepatitis.
Collapse
|
366
|
Kassel KM, Guo GL, Tawfik O, Luyendyk JP. Monocyte chemoattractant protein-1 deficiency does not affect steatosis or inflammation in livers of mice fed a methionine-choline-deficient diet. J Transl Med 2010; 90:1794-804. [PMID: 20697377 PMCID: PMC3082203 DOI: 10.1038/labinvest.2010.143] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Monocyte chemoattractant protein-1 (MCP-1, Ccl2) expression is increased in livers of patients with nonalcoholic steatohepatitis and in murine models of steatohepatitis. Several studies in rodents indicate that MCP-1 contributes to liver steatosis induced by feeding a high-fat diet. However, the extent of MCP-1 involvement in the widely utilized methionine-choline-deficient (MCD) diet model of steatohepatitis has not been determined. We tested the hypothesis that MCP-1 contributes to steatohepatitis in mice fed the MCD diet. MCP-1-deficient mice on a C57Bl/6J background and age-matched C57Bl/6J mice were fed either MCD diet or control diet for 4 weeks. MCP-1 deficiency did not affect steatohepatitis, as indicated by liver histopathology, nor did it affect serum alanine aminotransferase activity, hepatic triglyceride levels, hepatic inflammatory gene induction, or macrophage accumulation in mice fed the MCD diet. MCP-1 deficiency reduced the expression of the profibrogenic genes, pro-collagen 1a1, connective tissue growth factor, and transforming growth factor-β, in mice fed the MCD diet. MCP-1 deficiency significantly reduced collagen deposition and α-smooth muscle actin protein levels in the livers of mice fed the MCD diet. The results indicate that MCP-1 does not contribute to liver steatosis or inflammation in the MCD diet model of steatohepatitis. Rather, the data suggest that MCP-1 contributes to fibrosis in mice fed the MCD diet, independent of effects on steatosis and inflammation.
Collapse
|
367
|
Oral N-acetylcysteine rescues lethality of hepatocyte-specific Gclc-knockout mice, providing a model for hepatic cirrhosis. J Hepatol 2010; 53:1085-94. [PMID: 20810184 PMCID: PMC2970663 DOI: 10.1016/j.jhep.2010.05.028] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2009] [Revised: 05/11/2010] [Accepted: 05/25/2010] [Indexed: 01/28/2023]
Abstract
BACKGROUND & AIMS Certain liver diseases have been associated with depletion of glutathione (GSH), the major antioxidant in the liver. A recent report about Gclc(h/h) mice with a hepatocyte-specific ablation of Gclc (the gene encoding the catalytic subunit of the rate-limiting enzyme in GSH synthesis) has shown an essential role of GSH in hepatic function. Gclc(h/h) mice develop severe steatosis and die of liver failure within one month, due to ~95% depletion of hepatic GSH; mitochondria are the major affected organelles, displaying abnormal ultrastructure and impaired functioning. METHODS Gclc(h/h) mice were fed with L-N-acetylcysteine (NAC; 10 g/L) in drinking water, starting at postnatal day 18. RESULTS Gclc(h/h) mice were rescued by use of NAC supplementation, and survived until adulthood. NAC replenished the mitochondrial GSH pool and attenuated mitochondrial damage, with accompanying diminished hepatic steatosis; however, abnormal liver biochemical tests, hepatocyte death, and hepatic oxidative stress persisted in the rescued mice. At 50 days of age, the liver from rescued Gclc(h/h) mice started to display characteristics of fibrosis and at age 120 days, macronodular cirrhosis was observed. Immunohistostaining for liver-specific markers as well as the expression profile of hepatic cytokines indicated that the repopulation of hepatocytes in the cirrhotic nodules involved the expansion of oval cells. CONCLUSIONS Replenishment of mitochondrial GSH and restoration of mitochondrial function by NAC prevents mortality caused by the loss of hepatocyte GSH de novo synthesis, allowing steatosis to progress to a chronic stage. Thus, with NAC supplementation, Gclc(h/h) mice provide a model for the development of liver fibrosis and cirrhosis.
Collapse
|
368
|
Soon RK, Yan JS, Grenert JP, Maher JJ. Stress signaling in the methionine-choline-deficient model of murine fatty liver disease. Gastroenterology 2010; 139:1730-9, 1739.e1. [PMID: 20682321 PMCID: PMC2967598 DOI: 10.1053/j.gastro.2010.07.046] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2010] [Revised: 06/25/2010] [Accepted: 07/22/2010] [Indexed: 12/12/2022]
Abstract
BACKGROUND & AIMS Stress signaling, both within and outside the endoplasmic reticulum, has been linked to metabolic dysregulation and hepatic steatosis. Methionine-choline-deficient (MCD) diets cause severe fatty liver disease and have the potential to cause many types of cellular stress. The purpose of this study was to characterize hepatic stress in MCD-fed mice and explore the relationship between MCD-mediated stress and liver injury. METHODS Stress signaling was examined in mice fed MCD formulas for 4-21 days. Signaling also was evaluated in mice fed MCD formulas supplemented with clofibrate, which inhibits hepatic triglyceride accumulation. The role of the pro-apoptotic stress protein C/EBP homologous protein (CHOP) in MCD-mediated liver injury was assessed by comparing the responses of wild-type and CHOP-deficient mice to an MCD diet. RESULTS MCD feeding caused steatohepatitis coincident with the activation of cJun N-terminal kinase and caspase-12. In contrast, MCD feeding did not activate inositol-requiring protein-1 and actually suppressed the expression of X-box protein-1s. MCD feeding caused weak stimulation of double-stranded RNA-activated protein kinase-like endoplasmic reticulum-resident kinase, but robust activation of general control nonderepressible-2, followed by the phosphorylation of eukaryotic initiating factor-2α and induction of CHOP. Clofibrate eliminated MCD-mediated hepatic steatosis but did not inhibit diet-induced stress. CHOP deficiency did not alleviate, and in fact worsened, MCD-mediated liver disease. CONCLUSIONS MCD feeding causes an integrated stress response in the liver rather than a classic unfolded protein response. This stress response does not by itself lead to liver injury. CHOP, despite its identity as a mediator of stress-related cell death, does not play a central role in the pathogenesis of MCD-mediated liver disease.
Collapse
|
369
|
Caldwell S, Ikura Y, Dias D, Isomoto K, Yabu A, Moskaluk C, Pramoonjago P, Simmons W, Scruggs H, Rosenbaum N, Wilkinson T, Toms P, Argo CK, Al-Osaimi AMS, Redick JA. Hepatocellular ballooning in NASH. J Hepatol 2010; 53:719-23. [PMID: 20624660 PMCID: PMC2930100 DOI: 10.1016/j.jhep.2010.04.031] [Citation(s) in RCA: 155] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Revised: 03/25/2010] [Accepted: 04/15/2010] [Indexed: 12/12/2022]
Abstract
BACKGROUND & AIMS Hepatocellular ballooning is a key finding in nonalcoholic steatohepatitis (NASH). It is conventionally defined by hemotoxylin and eosin (H&E) staining showing enlarged cells with rarefied cytoplasm and recently by changes in the cytoskeleton. Fat droplets are emerging as important organelles in cell metabolism. To address a possible relation between fat droplets and ballooning, we studied fat staining, H&E, and keratin 18 staining in human NASH. METHODS Sequential staining and high resolution imaging were used to study freshly prepared cryo-sections from 10 patients with histologically confirmed steatohepatitis using oil red O for fat droplet identification, H&E to identify ballooning, and anti-K18 to confirm cytoskeletal changes. High resolution images were captured at each stage using the Aperio Scanscope. To provide ultrastructural correlation, glutaraldehyde-fixed specimens were studied using transmission electron microscopy (TEM) with serial sectioning for localization of ballooned cells by light microscopy and TEM in identical specimens. RESULTS Serial staining consistently demonstrated that hepatocellular ballooning is associated with fat droplet accumulation evident by oil red O positivity and depletion of cytoplasmic keratin 18 with K-18 positive Mallory-Denk bodies (MDB). TEM confirmed the association between osmium stained fat droplets, MDB formation, and cellular enlargement and suggested droplet-associated dilation of the endoplasmic reticulum. CONCLUSIONS These results indicate a relationship between cellular ballooning, fat droplet accumulation, and cytoskeletal injury in NASH. We speculate that injury to multiple, organelles including fat droplets and endoplasmic reticulum, contribute to this characteristic finding.
Collapse
|
370
|
Kirovski G, Gäbele E, Dorn C, Moleda L, Niessen C, Weiss TS, Wobser H, Schacherer D, Buechler C, Wasmuth HE, Hellerbrand C. Hepatic steatosis causes induction of the chemokine RANTES in the absence of significant hepatic inflammation. ZEITSCHRIFT FUR GASTROENTEROLOGIE 2010. [PMID: 20830238 DOI: 10.1055/s-0029-1246351] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) encompasses a spectrum ranging from simple steatosis to cirrhosis. Hepatocellular lipid accumulation is a hallmark of both nonalcoholic steatosis and steatohepatitis (NASH). The latter develops upon pro-inflammatory cell infiltration and is widely considered as the first relevant pathophysiological step in NAFLD-progression. The chemokine CCL5/RANTES plays an important role in the progression of hepatic inflammation and fibrosis. We here aimed to investigate its expression in NAFLD. Incubation of primary human hepatocytes with palmitic acid induced a dose-dependent lipid accumulation, and corresponding dose-dependent RANTES induction in vitro. Furthermore, we observed significantly elevated hepatic RANTES expression in a dietary model of NAFLD, in which mice were fed a high-fat diet for 12 weeks. This diet induced significant hepatic steatosis but only minimal inflammation. In contrast to the liver, RANTES expression was not induced in visceral adipose tissue of the group fed with high-fat diet. Finally, RANTES serum levels were elevated in patients with ultrasound-diagnosed NAFLD. In conclusion, our data indicate hepatocytes as cellular source of elevated hepatic as well as circulating RANTES levels in response to hepatic steatosis. Noteworthy, upregulation of RANTES in response to lipid accumulation occurs in the absence of relevant inflammation, which further indicates that hepatic steatosis per se has pathophysiological relevance and should not be considered as benign.
Collapse
|
371
|
Inoue M, Tazuma S, Kanno K, Hyogo H, Igarashi K, Chayama K. Bach1 gene ablation reduces steatohepatitis in mouse MCD diet model. J Clin Biochem Nutr 2010; 48:161-6. [PMID: 21373270 PMCID: PMC3045690 DOI: 10.3164/jcbn.09-122gfr] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2009] [Accepted: 02/11/2010] [Indexed: 12/22/2022] Open
Abstract
Bach1 is a transcriptional repressor of heme oxygenase-1 (HO-1, a.k.a. HSP-32), which is an inducible enzyme and has anti-oxidation/anti-inflammatory properties shown in various models of organ injuries. Since oxidative stress plays a pivotal role in the pathogenesis of nonalcoholic steatohepatitis (NASH), HO-1 induction would be expected to prevent the development of NASH. In this study, we investigated the influence of Bach1 ablation in mice on the progression of NASH in methionine-choline deficient (MCD) diet model. Bach1 ablation resulted in significant induction of HO-1 mRNA and its activity in the liver. When fed MCD diet, Bach1(-/-) mice exhibited negligible hepatic steatosis compared to pronounced steatohepatitis in wild type mice with 6-fold increase in hepatic triglyceride content. Whereas feeding of MCD diet decreased mRNA expressions of peroxisome proliferator-activated receptor (PPAR) α and microsomal triglyceride transfer protein (MTP) in wild type mice, there were no change in Bach1(-/-) mice. In addition, hepatic concentration of malondialdehyde (MDA), a biomarker for oxidative stress as well as plasma alanine aminotransferase (ALT) was significantly lower in Bach1(-/-) mice. These findings suggest that Bach1 ablation exerts hepatoprotective effect against steatohepatitis presumably via HO-1 induction and may be a potential therapeutic target.
Collapse
|
372
|
Allman M, Gaskin L, Rivera CA. CCl4-induced hepatic injury in mice fed a Western diet is associated with blunted healing. J Gastroenterol Hepatol 2010; 25:635-43. [PMID: 20370733 PMCID: PMC2953717 DOI: 10.1111/j.1440-1746.2009.06112.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND AND AIMS Feeding a Western diet (WD) enriched in saturated fat protects against chronic alcoholic hepatitis. However, saturated fat induces lipotoxicity in cultured hepatocytes. The purpose of the present study was to elucidate the influence of WD on acute hepatic injury and healing. METHODS Male C57BL/6 mice were fed a purified control diet (CD) or WD enriched in palmitate and cholesterol. After 3 weeks, carbon tetrachloride (CCl(4)) was administered (0.1 microL/g, intraperitoneally). Hepatic inflammation and proliferation were assessed by immunostaining for neutrophils and intracellular adhesion molecule-1, and Ki67, respectively. Cytokine expression was analyzed by real-time polymerase chain reaction. Protein levels of peroxisome proliferator-activated receptor-gamma (PPAR-gamma) were assessed by western blotting. RESULTS Feeding a WD resulted in markedly greater histological evidence of necrosis and enhanced alanine aminotransferase activity (188 +/- 6.2 U/L) compared to CD-fed mice (99.1 +/- 6.3 U/L) by day 2 post-CCl(4). In contrast, WD blunted leukocyte accumulation in necrotic areas and the expression of cytokines (tumor necrosis factor-alpha and interleukin-6) involved in tissue regeneration. Diminished repair was further indexed by lower collagen-alphaI and Ki67 expression in the mice fed a WD. Finally, feeding a WD, as well as the treatment of cultured hepatocytes with palmitic acid, upregulated the expression of PPAR-gamma, which has been previously shown to prevent hepatic repair following CCl(4) exposure. CONCLUSIONS These findings suggest that impaired healing in WD-fed mice blunted recovery from acute injury and underscored the complex relationship between diet and hepatic injury.
Collapse
|
373
|
Alkhouri N, Dixon LJ, Feldstein AE. Lipotoxicity in nonalcoholic fatty liver disease: not all lipids are created equal. Expert Rev Gastroenterol Hepatol 2009; 3:445-51. [PMID: 19673631 PMCID: PMC2775708 DOI: 10.1586/egh.09.32] [Citation(s) in RCA: 282] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is currently the most common form of chronic liver disease affecting both adults and children in the USA and many other parts of the world. NAFLD encompasses a wide spectrum of conditions associated with the overaccumulation of lipids in the liver, ranging from steatosis to nonalcoholic steatohepatitis, to cirrhosis and its feared complications of portal hypertension, liver failure and hepatocellular carcinoma. In this article, we will focus on the growing evidence linking changes in hepatic lipid metabolism and accumulation of specific lipid types in the liver with hepatocellular damage, inflammation and apoptosis, resulting in disease progression to the more serious forms of this condition.
Collapse
|
374
|
de la Monte SM, Longato L, Tong M, DeNucci S, Wands JR. The liver-brain axis of alcohol-mediated neurodegeneration: role of toxic lipids. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2009; 6:2055-75. [PMID: 19742171 PMCID: PMC2738898 DOI: 10.3390/ijerph6072055] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2009] [Accepted: 07/16/2009] [Indexed: 12/12/2022]
Abstract
Alcohol abuse causes progressive toxicity and degeneration in liver and brain due to insulin resistance, which exacerbates oxidative stress and pro-inflammatory cytokine activation. Alcohol-induced steatohepatitis promotes synthesis and accumulation of ceramides and other toxic lipids that cause insulin resistance. Ceramides can readily cross the blood-brain barrier, and ceramide exposure causes neurodegeneration with insulin resistance and oxidative stress, similar to the effects of alcohol. Therefore, in addition to its direct neurotoxic effects, alcohol misuse establishes a liver-brain axis of neurodegeneration mediated by toxic lipid trafficking across the blood-brain barrier, leading to progressive white matter degeneration and cognitive impairment.
Collapse
|
375
|
Syn WK, Teaberry V, Choi SS, Diehl AM. Similarities and differences in the pathogenesis of alcoholic and nonalcoholic steatohepatitis. Semin Liver Dis 2009; 29:200-10. [PMID: 19387919 PMCID: PMC3644873 DOI: 10.1055/s-0029-1214375] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Subpopulations of individuals with alcohol-induced fatty livers and nonalcoholic steatosis develop steatohepatitis. Steatohepatitis is defined histologically: increased numbers of injured and dying hepatocytes distinguish this condition from simple steatosis. The increased hepatocyte death is generally accompanied by hepatic accumulation of inflammatory cells and sometimes increases in myofibroblastic cells, leading to hepatic fibrosis and eventually, cirrhosis. The purpose of this review is to summarize similarities and differences in the pathogenesis of steatohepatitis in alcoholic fatty liver disease and nonalcoholic fatty liver disease.
Collapse
|