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Putra J, Toor A, Suriawinata AA. The utility of repeat liver biopsy in autoimmune hepatitis: a series of 20 consecutive cases. Pathology 2016; 48:449-53. [PMID: 27306577 DOI: 10.1016/j.pathol.2016.05.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 05/01/2016] [Accepted: 05/04/2016] [Indexed: 02/07/2023]
Abstract
Liver biopsy is recommended to establish the diagnosis and to assess remission in autoimmune hepatitis (AIH) patients. The aim of our study was to assess the utility of repeat biopsy in AIH. Forty liver biopsies from 20 consecutive AIH patients who underwent repeat biopsy were evaluated. We assessed the biopsies for histological findings other than AIH and how often the repeat biopsy led to a change in clinical management. Furthermore, we correlated the changes in the laboratory findings with the histological features. AIH patients in the study were mostly female (80%; average age 58.7 years). The most common indications for repeat biopsy included elevated transaminases (40%) and evaluation prior to treatment alteration (40%). Seventy percent of the patients showed improved aminotransferase levels, which demonstrated no significant correlation with the inflammatory (p = 1.000) or fibrosis progression (p = 0.116). Forty percent of the patients showed pathology other than AIH in the repeat biopsies (3 steatohepatitis; 5 cholangiopathy features). Changes in the management were seen in all patients. Repeat biopsy is important in AIH patients as aminotransferase levels are not always a reliable marker for inflammatory and fibrosis progression. Moreover, liver biopsy is an effective method for diagnosing comorbid liver conditions.
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302
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Jacobs A, Warda A, Verbeek J, Cassiman D, Spincemaille P. An Overview of Mouse Models of Nonalcoholic Steatohepatitis: From Past to Present. ACTA ACUST UNITED AC 2016; 6:185-200. [DOI: 10.1002/cpmo.3] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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303
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Hardy T, Oakley F, Anstee QM, Day CP. Nonalcoholic Fatty Liver Disease: Pathogenesis and Disease Spectrum. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2016; 11:451-96. [DOI: 10.1146/annurev-pathol-012615-044224] [Citation(s) in RCA: 340] [Impact Index Per Article: 42.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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304
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Villela-Nogueira CA, Leite NC, Cardoso CRL, Salles GF. NAFLD and Increased Aortic Stiffness: Parallel or Common Physiopathological Mechanisms? Int J Mol Sci 2016; 17:ijms17040460. [PMID: 27104526 PMCID: PMC4848916 DOI: 10.3390/ijms17040460] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 03/08/2016] [Accepted: 03/21/2016] [Indexed: 12/20/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) has become the leading cause of chronic liver diseases worldwide. Liver inflammation and fibrosis related to NAFLD contribute to disease progression and increasing liver-related mortality and morbidity. Increasing data suggest that NAFLD may be linked to atherosclerotic vascular disease independent of other established cardiovascular risk factors. Central arterial stiffness has been recognized as a measure of cumulative cardiovascular risk marker load, and the measure of carotid-femoral pulse wave velocity (cf-PWV) is regarded as the gold standard assessment of aortic stiffness. It has been shown that increased aortic stiffness predicts cardiovascular morbidity and mortality in several clinical settings, including type 2 diabetes mellitus, a well-known condition associated with advanced stages of NAFLD. Furthermore, recently-published studies reported a strong association between NAFLD and increased arterial stiffness, suggesting a possible link in the pathogenesis of atherosclerosis and NAFLD. We sought to review the published data on the associations between NAFLD and aortic stiffness, in order to better understand the interplay between these two conditions and identify possible common physiopathological mechanisms.
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305
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van der Veen JN, Lingrell S, Gao X, Quiroga AD, Takawale A, Armstrong EA, Yager JY, Kassiri Z, Lehner R, Vance DE, Jacobs RL. Pioglitazone attenuates hepatic inflammation and fibrosis in phosphatidylethanolamine N-methyltransferase-deficient mice. Am J Physiol Gastrointest Liver Physiol 2016; 310:G526-38. [PMID: 26797396 DOI: 10.1152/ajpgi.00243.2015] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 12/21/2015] [Indexed: 01/31/2023]
Abstract
Phosphatidylethanolamine N-methyltransferase (PEMT) is an important enzyme in hepatic phosphatidylcholine (PC) biosynthesis. Pemt(-/-) mice are protected against high-fat diet (HFD)-induced obesity and insulin resistance; however, these mice develop nonalcoholic fatty liver disease (NAFLD). We hypothesized that peroxisomal proliferator-activated receptor-γ (PPARγ) activation by pioglitazone might stimulate adipocyte proliferation, thereby directing lipids from the liver toward white adipose tissue. Pioglitazone might also act directly on PPARγ in the liver to improve NAFLD. Pemt(+/+) and Pemt(-/-) mice were fed a HFD with or without pioglitazone (20 mg·kg(-1)·day(-1)) for 10 wk. Pemt(-/-) mice were protected from HFD-induced obesity but developed NAFLD. Treatment with pioglitazone caused an increase in body weight gain in Pemt(-/-) mice that was mainly due to increased adiposity. Moreover, pioglitazone improved NAFLD in Pemt(-/-) mice, as indicated by a 35% reduction in liver weight and a 57% decrease in plasma alanine transaminase levels. Livers from HFD-fed Pemt(-/-) mice were steatotic, inflamed, and fibrotic. Hepatic steatosis was still evident in pioglitazone-treated Pemt(-/-) mice; however, treatment with pioglitazone reduced hepatic fibrosis, as evidenced by reduced Sirius red staining and lowered mRNA levels of collagen type Iα1 (Col1a1), tissue inhibitor of metalloproteinases 1 (Timp1), α-smooth muscle actin (Acta2), and transforming growth factor-β (Tgf-β). Similarly, oxidative stress and inflammation were reduced in livers from Pemt(-/-) mice upon treatment with pioglitazone. Together, these data show that activation of PPARγ in HFD-fed Pemt(-/-) mice improved liver function, while these mice were still protected against diet-induced obesity and insulin resistance.
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Abstract
Nonalcoholic fatty liver disease (NAFLD) has gained importance in recent decades due to drastic changes in diet, especially in Western countries. NAFLD occurs as a spectrum from simple hepatic steatosis, steatohepatitis to cirrhosis, and even hepatocellular carcinoma. Although the molecular mechanisms underlying the development of NAFLD have been intensively investigated, many issues remain to be resolved. Autophagy is a cell survival mechanism for disposing of excess or defective organelles, and has become a hot spot for research. Recent studies have revealed that autophagy is linked to the development of NAFLD and regulation of autophagy has therapeutic potential. Autophagy reduces intracellular lipid droplets by enclosing them and fusing with lysosomes for degradation. Furthermore, autophagy is involved in attenuating inflammation and liver injury. However, autophagy is regarded as a double-edged sword, as it may also affect adipogenesis and adipocyte differentiation. Moreover, it is unclear as to whether autophagy protects the body from injury or causes diseases and even death, and the association between autophagy and NAFLD remains controversial. This review is intended to discuss, comment, and outline the progress made in this field and establish the possible molecular mechanism involved.
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Extracellular Vesicles: A New Frontier in Biomarker Discovery for Non-Alcoholic Fatty Liver Disease. Int J Mol Sci 2016; 17:376. [PMID: 26985892 PMCID: PMC4813235 DOI: 10.3390/ijms17030376] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 03/01/2016] [Accepted: 03/02/2016] [Indexed: 12/14/2022] Open
Abstract
In recent years, the global burden of obesity and diabetes has seen a parallel rise in other metabolic complications, such as non-alcoholic fatty liver disease (NAFLD). This condition, once thought to be a benign accumulation of hepatic fat, is now recognized as a serious and prevalent disorder that is conducive to inflammation and fibrosis. Despite the rising incidence of NAFLD, there is currently no reliable method for its diagnosis or staging besides the highly invasive tissue biopsy. This limitation has resulted in the study of novel circulating markers as potential candidates, one of the most popular being extracellular vesicles (EVs). These submicron membrane-bound structures are secreted from stressed and activated cells, or are formed during apoptosis, and are known to be involved in intercellular communication. The cargo of EVs depends upon the parent cell and has been shown to be changed in disease, as is their abundance in the circulation. The role of EVs in immunity and epigenetic regulation is widely attested, and studies showing a correlation with disease severity have made these structures a favorable target for diagnostic as well as therapeutic purposes. This review will highlight the research that is available on EVs in the context of NAFLD, the current limitations, and projections for their future utility in a clinical setting.
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308
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Hardy T, Oakley F, Anstee QM, Day CP. Nonalcoholic Fatty Liver Disease: Pathogenesis and Disease Spectrum. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2016. [PMID: 26980160 DOI: 10.1146/annrev-pathol-012615-044224] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is the most common cause of liver dysfunction in the Western world and is increasing owing to its close association with obesity and insulin resistance. NAFLD represents a spectrum of liver disease that, in a minority of patients, can lead to progressive nonalcoholic steatohepatitis (NASH), fibrosis, and ultimately hepatocellular carcinoma and liver failure. NAFLD is a complex trait resulting from the interaction between environmental exposure and a susceptible polygenic background and comprising multiple independent modifiers of risk, such as the microbiome. The molecular mechanisms that combine to define the transition to NASH and progressive disease are complex, and consequently, no pharmacological therapy currently exists to treat NASH. A better understanding of the pathogenesis of NAFLD is critical if new treatments are to be discovered.
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309
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Liu K, Zhao E, Ilyas G, Lalazar G, Lin Y, Haseeb M, Tanaka KE, Czaja MJ. Impaired macrophage autophagy increases the immune response in obese mice by promoting proinflammatory macrophage polarization. Autophagy 2016; 11:271-84. [PMID: 25650776 DOI: 10.1080/15548627.2015.1009787] [Citation(s) in RCA: 329] [Impact Index Per Article: 41.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Recent evidence that excessive lipid accumulation can decrease cellular levels of autophagy and that autophagy regulates immune responsiveness suggested that impaired macrophage autophagy may promote the increased innate immune activation that underlies obesity. Primary bone marrow-derived macrophages (BMDM) and peritoneal macrophages from high-fat diet (HFD)-fed mice had decreased levels of autophagic flux indicating a generalized impairment of macrophage autophagy in obese mice. To assess the effects of decreased macrophage autophagy on inflammation, mice with a Lyz2-Cre-mediated knockout of Atg5 in macrophages were fed a HFD and treated with low-dose lipopolysaccharide (LPS). Knockout mice developed systemic and hepatic inflammation with HFD feeding and LPS. This effect was liver specific as knockout mice did not have increased adipose tissue inflammation. The mechanism by which the loss of autophagy promoted inflammation was through the regulation of macrophage polarization. BMDM and Kupffer cells from knockout mice exhibited abnormalities in polarization with both increased proinflammatory M1 and decreased anti-inflammatory M2 polarization as determined by measures of genes and proteins. The heightened hepatic inflammatory response in HFD-fed, LPS-treated knockout mice led to liver injury without affecting steatosis. These findings demonstrate that autophagy has a critical regulatory function in macrophage polarization that downregulates inflammation. Defects in macrophage autophagy may underlie inflammatory disease states such as the decrease in macrophage autophagy with obesity that leads to hepatic inflammation and the progression to liver injury.
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Key Words
- ARG1, arginase 1
- BMDM, bone marrow-derived macrophages
- CCL, chemokine (C-C motif) ligand
- CD, chow diet
- CHIL3/CHI3L3, chitinase-like 3
- GAPDH, glyceraldehyde-3-phosphate dehydrogenase
- GFP, green fluorescent protein
- GPT, glutamic pyruvic transaminase, soluble
- HFD, high-fat diet
- IFNG, interferon gamma
- IL, interleukin
- Kupffer cells
- LPS, lipopolysaccharide
- MAP1LC3/LC3B, microtubule-associated protein 1 light chain 3 β
- MAPK, mitogen-activated protein kinase
- MGL2, macrophage galactose N-acetyl-galactosamine specific lectin 2
- NOS2, nitric oxide synthase 2, inducible
- PBS, phosphate-buffered saline
- PTGS2, prostaglandin-endoperoxide synthase 2
- RETNLA, resistin like α;
- STAT, signal transducer and activator of transcription
- TNF, tumor necrosis factor
- TUNEL, terminal deoxynucleotide transferase-mediated deoxyuridine triphosphate nick end-labeling
- WAT, white adipose tissue
- autophagy
- innate immunity
- lipopolysaccharide
- macrophage
- obesity
- polarization
- qRT-PCR, quantitative real-time PCR
- steatohepatitis
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Parikh P, Ingle M, Patel J, Bhate P, Pandey V, Sawant P. An open-label randomized control study to compare the efficacy of vitamin e versus ursodeoxycholic acid in nondiabetic and noncirrhotic Indian NAFLD patients. Saudi J Gastroenterol 2016; 22:192-7. [PMID: 27184636 PMCID: PMC4898087 DOI: 10.4103/1319-3767.182451] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND/AIM The study was carried out to compare the efficacy of Vitamin E versus Ursodeoxycholic acid (UDCA) in nondiabetic nonalcoholic fatty liver disease (NAFLD) patients. PATIENTS AND METHODS We randomized 250 non cirrhotic and non diabetic NAFLD patients diagnosed on ultrasound, with raised alanine aminotransferase (ALT) level. (>40 IU/L), to receive Vitamin E 400 mg twice a day (Group A) or UDCA 300 mg twice a day (Group B) for 52 weeks. Lifestyle modification to achieve at least 5% weight reduction and subsequent weight control and regular exercise was advised to both groups. The primary study endpoint was normalization of ALT. Secondary endpoints were the proportion of patients with reduction in ALT, relative reduction in the NAFLD Fibrosis score (NFS), symptomatic improvement and tolerability. RESULTS One hundred and fifty patients received UDCA as compared to 100 patients receiving Vitamin E. The treatment groups were comparable at entry with regard to age (44.1 vs 42.4 years), gender (67% vs 63% female), risk factors for nonalcoholic steatohepatitis, hypochondriac pain, serum liver biochemistries, and NAFLD Fibrosis score. The primary endpoint was achieved in 21 (14%) and 19 (19%) of patients in Group A and Group B, respectively (P = 0.2). The proportion of patients with reduction in ALT (56% vs 63%, P = 0.2), symptomatic improvement (78% vs 67%, P= 0.058), reduction in the NFS (44% vs 47%, P= 0.69), and tolerability (98% vs 95%, P= 0.2) were similar between Group A and Group B, respectively. CONCLUSION UDCA is an effective and safe alternative to Vitamin E in nondiabetic-noncirrhotic Indian NAFLD patients.
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311
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Mann JP, Semple RK, Armstrong MJ. How Useful Are Monogenic Rodent Models for the Study of Human Non-Alcoholic Fatty Liver Disease? Front Endocrinol (Lausanne) 2016; 7:145. [PMID: 27899914 PMCID: PMC5110950 DOI: 10.3389/fendo.2016.00145] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2016] [Accepted: 11/01/2016] [Indexed: 12/22/2022] Open
Abstract
Improving understanding of the genetic basis of human non-alcoholic fatty liver disease (NAFLD) has the potential to facilitate risk stratification of affected patients, permit personalized treatment, and inform development of new therapeutic strategies. Animal models have been widely used to interrogate the pathophysiology of, and genetic predisposition to, NAFLD. Nevertheless, considerable interspecies differences in intermediary metabolism potentially limit the extent to which results can be extrapolated to humans. For example, human genome-wide association studies have identified polymorphisms in PNPLA3 and TM6SF2 as the two most prevalent determinants of susceptibility to NAFLD and its inflammatory component (NASH), but animal models of these mutations have had only variable success in recapitulating this link. In this review, we critically appraise selected murine monogenic models of NAFLD, NASH, and hepatocellular carcinoma (HCC) with a focus on how closely they mirror human disease.
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312
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Baffy G. MicroRNAs in Nonalcoholic Fatty Liver Disease. J Clin Med 2015; 4:1977-88. [PMID: 26690233 PMCID: PMC4693153 DOI: 10.3390/jcm4121953] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Revised: 11/20/2015] [Accepted: 11/27/2015] [Indexed: 02/07/2023] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) has become the most common liver disorder. Strongly linked to obesity and diabetes, NAFLD has the characteristics of complex diseases with substantial heterogeneity. Accordingly, our ability to predict the risk of advanced NAFLD and provide efficient treatment may improve by a better understanding of the relationship between genotype and phenotype. MicroRNAs (miRNAs) play a major role in the fine-tuning of gene expression and they have recently emerged as novel biomarkers and therapeutic tools in the management of NAFLD. These short non-coding RNA sequences act by partial repression or degradation of targeted mRNAs. Deregulation of miRNAs has been associated with different stages of NAFLD, while their biological role in the pathogenesis remains to be fully understood. Systems biology analyses based on predicted target genes have associated hepatic miRNAs with molecular pathways involved in NAFLD progression such as cholesterol and lipid metabolism, insulin signaling, oxidative stress, inflammation, and pathways of cell survival and proliferation. Moreover, circulating miRNAs have been identified as promising noninvasive biomarkers of NAFLD and linked to disease severity. This rapidly growing field is likely to result in major advances in the pathomechanism, prognostication, and treatment of NAFLD.
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313
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Amarapurkar D, Amarapurkar A. Indications of Liver Biopsy in the Era of Noninvasive Assessment of Liver Fibrosis. J Clin Exp Hepatol 2015; 5:314-9. [PMID: 26900273 PMCID: PMC4723644 DOI: 10.1016/j.jceh.2015.08.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Accepted: 08/24/2015] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Liver biopsy (LB) has been used as diagnostic modality in liver diseases (LD). Over last two decades, there has been remarkable improvement in understanding of natural history, molecular diagnostics of viral hepatitis, genetic of LD, and also limitations of LB. There is current trend in avoiding LB in the management of various LDs. AIM To determine utility of LB in clinical practice. MATERIAL AND METHODS In a prospective study, 2413 patients of LD were followed up, 219 (9%) were acute, and remaining 2194 (90.9%) were chronic LD. Patients were evaluated by biochemical parameters, virological studies, and imaging endoscopy as and when required. LB was performed in 176 (7.2%) patients when no conclusion could be drawn from the noninvasive workup. Patients with platelet count <50,000/cm(2), ascites, and overt bleeding were excluded. Patients with international normalization ratio (INR) more than 1.5 were not excluded. No prophylactic use of fresh frozen plasma and platelet transfusion was done. There was no major complication related to the procedure. Indications for LB were as follows: cryptogenic LD 38 cases, hepatitis B infection 35, suspected autoimmune hepatitis 30, mass lesion in the liver and lymphoma 29, evaluation of portal hypertension 15, elevated liver enzymes 11, hepatitis C infection 9, and drug-induced LD 4, and miscellaneous 5 cases which were primary biliary cholangitis, primary sclerosing cholangitis, cholestatic LD, sarcoidosis, and amyloidosis. RESULTS LB changed the diagnosis in 55 (31.2%). These were cryptogenic LD in 24 cases, portal hypertension 15, elevated liver enzymes 11, and 5 others. In remaining, LB confirmed clinical diagnosis and helped in making management decisions. CONCLUSION LB was required in 7.2% of patients with chronic LD. In 31.2% cases, LB changed the diagnosis. LB was a safe procedure even in presence of low platelet count and abnormal INR.
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Key Words
- AIH, autoimmune hepatitis
- APRI, aspartate transaminases to platelet ratio index
- CMV, cytomegalovirus
- EBV, Epstein bar virus
- HCC, hepatocellular carcinoma
- HEV, hepatitis E virus
- INCPH, idiopathic noncirrhotic portal hypertension
- LB, liver biopsy
- LD, liver disease
- NAFLD, nonalcoholic fatty liver disease
- NASH, nonalcoholic steatohepatitis
- NRH, nodular regenerative hyperplasia
- autoimmune hepatitis
- cryptogenic cirrhosis
- noncirrhotic portal hypertension
- steatohepatitis
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314
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Wahlang B, Prough RA, Falkner KC, Hardesty JE, Song M, Clair HB, Clark BJ, States JC, Arteel GE, Cave MC. Polychlorinated Biphenyl-Xenobiotic Nuclear Receptor Interactions Regulate Energy Metabolism, Behavior, and Inflammation in Non-alcoholic- Steatohepatitis. Toxicol Sci 2015; 149:396-410. [PMID: 26612838 DOI: 10.1093/toxsci/kfv250] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Polychlorinated biphenyls (PCBs) are environmental pollutants associated with non-alcoholic-steatohepatitis (NASH), diabetes, and obesity. We previously demonstrated that the PCB mixture, Aroclor 1260, induced steatohepatitis and activated nuclear receptors in a diet-induced obesity mouse model. This study aims to evaluate PCB interactions with the pregnane-xenobiotic receptor (Pxr: Nr1i2) and constitutive androstane receptor (Car: Nr1i3) in NASH. Wild type C57Bl/6 (WT), Pxr(-/-) and Car(-/-) mice were fed the high fat diet (42% milk fat) and exposed to a single dose of Aroclor 1260 (20 mg/kg) in this 12-week study. Metabolic phenotyping and analysis of serum, liver, and adipose was performed. Steatohepatitis was pathologically similar in all Aroclor-exposed groups, while Pxr(-/-) mice displayed higher basal pro-inflammatory cytokine levels. Pxr repressed Car expression as evident by increased basal Car/Cyp2b10 expression in Pxr(-/-) mice. Both Pxr(-/-) and Car(-/-) mice showed decreased basal respiratory exchange rate (RER) consistent with preferential lipid metabolism. Aroclor increased RER and carbohydrate metabolism, associated with increased light cycle activity in both knockouts, and decreased food consumption in the Car(-/-) mice. Aroclor exposure improved insulin sensitivity in WT mice but not glucose tolerance. The Aroclor-exposed, Pxr(-/-) mice displayed increased gluconeogenic gene expression. Lipid-oxidative gene expression was higher in WT and Pxr(-/-) mice although RER was not changed, suggesting PCB-mediated mitochondrial dysfunction. Therefore, Pxr and Car regulated inflammation, behavior, and energy metabolism in PCB-mediated NASH. Future studies should address the 'off-target' effects of PCBs in steatohepatitis.
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315
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Torok NJ. Update on Alcoholic Hepatitis. Biomolecules 2015; 5:2978-86. [PMID: 26540078 PMCID: PMC4693265 DOI: 10.3390/biom5042978] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2015] [Revised: 10/26/2015] [Accepted: 10/29/2015] [Indexed: 12/12/2022] Open
Abstract
Alcoholic liver disease is one of the most prevalent liver diseases worldwide, and a major cause of morbidity and mortality. Alcoholic hepatitis is a severe form of liver injury in patients with alcohol abuse, can present as an acute on chronic liver failure associated with a rapid decline in liver synthetic function, and consequent increase in mortality. Despite therapy, about 30%-50% of patients with severe alcoholic hepatitis eventually die. The pathogenic pathways that lead to the development of alcoholic hepatitis are complex and involve oxidative stress, gut dysbiosis, and dysregulation of the innate and adaptive immune system with injury to the parenchymal cells and activation of hepatic stellate cells. As accepted treatment approaches are currently limited, a better understanding of the pathophysiology would be required to generate new approaches that improve outcomes. This review focuses on recent advances in the diagnosis, pathogenesis of alcoholic hepatitis and novel treatment strategies.
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316
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Geng T, Sutter A, Harland MD, Law BA, Ross JS, Lewin D, Palanisamy A, Russo SB, Chavin KD, Cowart LA. SphK1 mediates hepatic inflammation in a mouse model of NASH induced by high saturated fat feeding and initiates proinflammatory signaling in hepatocytes. J Lipid Res 2015; 56:2359-71. [PMID: 26482537 DOI: 10.1194/jlr.m063511] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Indexed: 11/20/2022] Open
Abstract
Steatohepatitis occurs in up to 20% of patients with fatty liver disease and leads to its primary disease outcomes, including fibrosis, cirrhosis, and increased risk of hepatocellular carcinoma. Mechanisms that mediate this inflammation are of major interest. We previously showed that overload of saturated fatty acids, such as that which occurs with metabolic syndrome, induced sphingosine kinase 1 (SphK1), an enzyme that generates sphingosine-1-phosphate (S1P). While data suggest beneficial roles for S1P in some contexts, we hypothesized that it may promote hepatic inflammation in the context of obesity. Consistent with this, we observed 2-fold elevation of this enzyme in livers from humans with nonalcoholic fatty liver disease and also in mice with high saturated fat feeding, which recapitulated the human disease. Mice exhibited activation of NFκB, elevated cytokine production, and immune cell infiltration. Importantly, SphK1-null mice were protected from these outcomes. Studies in cultured cells demonstrated saturated fatty acid induction of SphK1 message, protein, and activity, and also a requirement of the enzyme for NFκB signaling and increased mRNA encoding TNFα and MCP1. Moreover, saturated fat-induced NFκB signaling and elevation of TNFα and MCP1 mRNA in HepG2 cells was blocked by targeted knockdown of S1P receptor 1, supporting a role for this lipid signaling pathway in inflammation in nonalcoholic fatty liver disease.
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317
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Abstract
The burden of hepatocellular carcinoma (HCC), the most common form of liver cancer, is steadily growing because obesity, type 2 diabetes, and nonalcoholic fatty liver disease (NAFLD) are replacing viral- and alcohol-related liver disease as major pathogenic promoters. The most worrisome aspects of these new risk factors are their large spread in the general population and their link with HCC arising in noncirrhotic livers. HCC may be the presenting feature of an asymptomatic nonalcoholic steatohepatitis (NASH), the progressive form of NAFLD. The HCC risk connected to metabolic factors has been underestimated so far, and a poorer surveillance has prevented an adequate treatment. Systemic and hepatic molecular mechanisms involved in obesity- and NAFLD-induced hepatocarcinogenesis as well as potential early markers of HCC are being extensively investigated. This review summarizes current evidence linking obesity, NAFLD and liver cancer, discusses its clinical impact and describes the main mechanisms underlying this complex relationship.
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318
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Chaix A, Zarrinpar A. The effects of time-restricted feeding on lipid metabolism and adiposity. Adipocyte 2015; 4:319-24. [PMID: 26451290 DOI: 10.1080/21623945.2015.1025184] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Revised: 02/25/2015] [Accepted: 02/25/2015] [Indexed: 01/06/2023] Open
Abstract
Maintaining natural feeding rhythms with time-restricted feeding (TRF), without altering nutritional intake, prevents and reverses diet-induced obesity (DIO) and its associated metabolic disorders in mice. TRF has a direct effect on animal adiposity, causes an alteration of adipokine signaling, and diminishes white adipose tissue inflammation. Many genes involved in lipid metabolism are normally circadian, but their expression is perturbed with DIO; TRF restores their cyclical expression. One mechanism through which TRF could affect host metabolism is by altering the gut microbiome. Changes in the gut microbiome are coupled with an altered stool bile acid profile. Hence, TRF could affect lipid metabolism by altering bile acid signaling. TRF introduces many new possibilities in treating obesity and its associated metabolic disorders. However, further studies are needed to show whether these physiological findings in mice translate to humans.
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319
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Bril F, Ortiz-Lopez C, Lomonaco R, Orsak B, Freckleton M, Chintapalli K, Hardies J, Lai S, Solano F, Tio F, Cusi K. Clinical value of liver ultrasound for the diagnosis of nonalcoholic fatty liver disease in overweight and obese patients. Liver Int 2015; 35:2139-46. [PMID: 25847730 DOI: 10.1111/liv.12840] [Citation(s) in RCA: 150] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2015] [Accepted: 03/23/2015] [Indexed: 12/13/2022]
Abstract
BACKGROUND & AIMS Liver ultrasound (US) is usually used in the clinical setting for the diagnosis and follow-up of patients with nonalcoholic fatty liver disease (NAFLD). However, no large study has carefully assessed its performance using a semiquantitative ultrasonographic scoring system in overweight/obese patients, in comparison to magnetic resonance spectroscopy ((1) H-MRS) and histology. METHODS We recruited 146 patients and performed: a liver US using a 5-parameter scoring system, a liver (1) H-MRS to quantify liver fat content, and a liver biopsy to assess histology. All measurements were repeated in a subgroup of patients (n = 62) after 18 months of follow-up. RESULTS The performance of liver US (parenchymal echo alone) was rather modest, and significantly worse than (1) H-MRS (AUROC: 0.82 [0.69-0.94] vs. 0.96 [0.90-1.00]; P = 0.04). However, the AUROC improved when different echographic parameters were taken into account (AUROC: 0.89 [0.83-0.96], P = 0.15 against (1) H-MRS). Optimum sensitivity for liver US was achieved at a liver fat content ≥12.5%, suggesting that below this threshold, liver US is less sensitive. Liver (1) H-MRS showed a high accuracy for the diagnosis of NAFLD, and correlated strongly with histological steatosis (r = 0.73, P < 0.0001). None of the imaging tests was adequate enough to predict changes over time in histology. CONCLUSIONS Despite its widespread use, liver US has several important limitations that healthcare providers should recognize, particularly because of its low sensitivity. Using a combination of echographic parameters, liver US showed a significant improvement in its diagnostic performance, but still was of limited value for monitoring treatment over time.
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Pizarro M, Solís N, Quintero P, Barrera F, Cabrera D, Santiago PR, Arab JP, Padilla O, Roa JC, Moshage H, Wree A, Inzaugarat E, Feldstein AE, Fardella CE, Baudrand R, Riquelme A, Arrese M. Beneficial effects of mineralocorticoid receptor blockade in experimental non-alcoholic steatohepatitis. Liver Int 2015; 35:2129-38. [PMID: 25646700 PMCID: PMC4522413 DOI: 10.1111/liv.12794] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 01/28/2015] [Indexed: 12/14/2022]
Abstract
BACKGROUND Therapeutic options to treat Non-alcoholic steatohepatitis (NASH) are limited. Mineralocorticoid receptor (MR) activation could play a role in hepatic fibrogenesis and its modulation could be beneficial for NASH. AIM To investigate whether eplerenone, a specific MR antagonist, ameliorates liver damage in experimental NASH. METHODS C57bl6 mice were fed a choline-deficient and amino acid-defined (CDAA) diet for 22 weeks with or without eplerenone supplementation. Serum levels of aminotransferases and aldosterone were measured and hepatic steatosis, inflammation and fibrosis scored histologically. Hepatic triglyceride content (HTC) and hepatic mRNA levels of pro-inflammatory pro-fibrotic, oxidative stress-associated genes and of MR were also assessed. RESULTS CDAA diet effectively induced fibrotic NASH, and increased the hepatic expression of pro-inflammatory, pro-fibrotic and oxidative stress-associated genes. Hepatic MR mRNA levels significantly correlated with the expression of pro-inflammatory and pro-fibrotic genes and were significantly increased in hepatic stellate cells obtained from CDAA-fed animals. Eplerenone administration was associated to a reduction in histological steatosis and attenuation of liver fibrosis development, which was associated to a significant decrease in the expression of collagen-α1, collagen type III, alpha 1 and Matrix metalloproteinase-2. CONCLUSION The expression of MR correlates with inflammation and fibrosis development in experimental NASH. Specific MR blockade with eplerenone has hepatic anti-steatotic and anti-fibrotic effects. These data identify eplerenone as a potential novel therapy for NASH. Considering its safety and FDA-approved status, human studies are warranted.
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Rusu E, Enache G, Jinga M, Dragut R, Nan R, Popescu H, Parpala C, Homentcovschi C, Nitescu M, Stoian M, Costache A, Posea M, Rusu F, Jinga V, Mischianu D, Radulian G. Medical nutrition therapy in non-alcoholic fatty liver disease--a review of literature. J Med Life 2015; 8:258-62. [PMID: 26351523 PMCID: PMC4556902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 04/29/2015] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND AIM Non-alcoholic fatty liver disease (NAFLD) is the most common cause of liver disease worldwide, with a prevalence of 20%-40% in Western populations. The purpose of this article is to review data related to lifestyle changes in patients with NAFLD. METHOD We searched a public domain database (PubMed) with the following categories: disease (NAFLD, fatty liver, and non-alcoholic steatohepatitis [NASH]) and intervention (lifestyle intervention, diet, nutrition) with each possible combination through 25 September 2014, for relevant articles. Review of articles was restricted to those published in English. We selected the studies involving adult patients only. CONCLUSION There is no consensus as to what diet or lifestyle approach is the best for NAFLD patients. However, patients with NAFLD may benefit from a moderate- to low-carbohydrate (40%-45% of total calories) diet, coupled with increased dietary MUFA and n-3 PUFAs, reduced SFAs. More CRT are needed to clarify the specific effects of different diets and dietary components on the health of NAFLD patients. ABBREVIATIONS NAFL = Non-alcoholic fatty liver, NAFLD = non-alcoholic fatty liver disease, NASH = non-alcoholic steatohepatitis, HCC = hepatocarcinoma, BEE = basal energy expenditure, CRT = A small clinical randomized trial showed that short-term carbohydrate restriction is more efficacious in reducing intrahepatic triglyceride, IHT = intrahepatic triglyceride, VLCD = Very low calorie diets, AST = aspartate aminotransferases, SFAs = saturated fatty acids.
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Tomeno W, Kawashima K, Yoneda M, Saito S, Ogawa Y, Honda Y, Kessoku T, Imajo K, Mawatari H, Fujita K, Saito S, Hirayasu Y, Nakajima A. Non-alcoholic fatty liver disease comorbid with major depressive disorder: The pathological features and poor therapeutic efficacy. J Gastroenterol Hepatol 2015; 30:1009-14. [PMID: 25619308 DOI: 10.1111/jgh.12897] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/24/2014] [Indexed: 12/12/2022]
Abstract
BACKGROUND AND AIM Major depressive disorder (MDD) is an important public health problem, and it is often comorbid with many chronic diseases. The purpose of this study was to identify the clinical features of non-alcoholic fatty liver disease (NAFLD) patients comorbid with MDD and to investigate the influence of MDD on the effect of treatment in patients with NAFLD. METHODS A total of 258 patients with biopsy-proven NAFLD were included. MDD was diagnosed according to the criteria of the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, text revision. The patients were followed up for 48 weeks under standard care for NAFLD, which consisted mainly of lifestyle modification. RESULTS There were 32 patients comorbid with MDD. They were characterized by more severe histological steatosis and higher NAFLD activity score, and also significantly higher levels of serum aminotransferase, γ-glutamyl transpeptidase and ferritin, than age-and-sex-matched NAFLD patients without MDD. Moreover, NAFLD patients with MDD showed poor response to the standard care for NAFLD, in body weight loss and in other parameters. Particularly, NAFLD patients with unstable MDD (not in full/partial remission) showed severe resistance to the treatment. CONCLUSION This is the first study to demonstrate the clinical features and response to therapy of NAFLD patients comorbid with MDD. The comorbid state of MDD was associated with more severe histological liver steatosis and worse treatment outcomes in patients with NAFLD. Further investigations are required to develop new lifestyle modification programs that enable NAFLD patients with MDD to achieve the treatment goal.
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Rudwill F, Bergouignan A, Gastebois C, Gauquelin-Koch G, Lefai E, Blanc S, Simon C. Effect of enforced physical inactivity induced by 60-day of bed rest on hepatic markers of NAFLD in healthy normal-weight women. Liver Int 2015; 35:1700-6. [PMID: 25413107 DOI: 10.1111/liv.12743] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 11/17/2014] [Indexed: 12/21/2022]
Abstract
BACKGROUND & AIMS Physical inactivity leads to a cluster of metabolic disorders that have been associated with non-alcoholic fatty liver diseases. We tested whether physical inactivity increases hepatic biomarkers of NAFLDs. METHODS Sixteen normal-weight healthy women (body mass index = 21.2 ± 0.5 kg/m(2) ) were studied under controlled energy balance conditions during a previous 60-day bed rest with (n = 8) or without (n = 8) a combined aerobic/resistive exercise protocol. Stored samples were retrospectively used to measure plasma hepatic markers, i.e. steatosis-related alanine and aspartate transaminases, cytokeratin 18 and angiopoietin-like 3, at baseline, after 30 and 60 days of bed rest. Fasting insulin and triglycerides were measured at baseline and after 30 days of bed rest. Two indexes were calculated, one combining alanine and aspartate transaminase and cytokeratin 18 and another cytokeratin 18, homeostasis model assessment of insulin resistance and aspartate aminotransferase. RESULTS Sixty days of bed rest increased all hepatic markers (P < 0.05 for all) and the two indexes (P < 0.01 for both). Exercise significantly reduced the elevation in aspartate transaminase, cytokeratin 18 and both indexes (P < 0.02 for all) but not the increase in alanine transaminase and angiopoietin-like 3. Changes between baseline and 30 days of bed rest in triglycerides were positively associated with changes in aspartate transaminase (R(2) = 0.28, P = 0.04) suggesting a role of hypertriglyceridaemia in the alteration of liver metabolism under inactive conditions. CONCLUSION Physical inactivity increases, independent of fat mass, hepatic markers of steatosis and steatohepatitis. Regular exercise can limit these physical inactivity-induced metabolic alterations. Future studies need to elucidate the underlying mechanisms.
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Bhatt HB, Smith RJ. Fatty liver disease in diabetes mellitus. Hepatobiliary Surg Nutr 2015; 4:101-8. [PMID: 26005676 DOI: 10.3978/j.issn.2304-3881.2015.01.03] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 12/09/2014] [Indexed: 12/20/2022]
Abstract
Non-alcoholic fatty liver disease (NAFLD) is highly prevalent in type 2 diabetes mellitus (T2DM), likely reflecting the frequent occurrence of obesity and insulin resistance in T2DM. NAFLD also can occur in type 1 DM (T1DM), but must be distinguished from the more common glycogen hepatopathy as a cause of hepatomegaly and liver function abnormalities in T1DM. Weight reduction achieved by diet and exercise is effective in preventing and treating NAFLD in obese diabetic subjects. Bariatric surgery also has been shown to reverse NAFLD in T2DM, and recently approved weight loss medications should be evaluated for their impact on the development and progression of NAFLD. There is limited evidence suggesting that specific drugs used for blood glucose control in T2DM [thiazolidinediones (TZDs), glucagon-like peptide-1 (GLP-1) analogs, and dipeptidyl peptidase-4 (DPP-4) inhibitors] and also statins may have a role in preventing or treating NAFLD in patients with diabetes.
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Carr RM, Correnti J. Insulin resistance in clinical and experimental alcoholic liver disease. Ann N Y Acad Sci 2015; 1353:1-20. [PMID: 25998863 DOI: 10.1111/nyas.12787] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Alcoholic liver disease (ALD) is the number one cause of liver failure worldwide; its management costs billions of healthcare dollars annually. Since the advent of the obesity epidemic, insulin resistance (IR) and diabetes have become common clinical findings in patients with ALD; and the development of IR predicts the progression from simple steatosis to cirrhosis in ALD patients. Both clinical and experimental data implicate the impairment of several mediators of insulin signaling in ALD, and experimental data suggest that insulin-sensitizing therapies improve liver histology. This review explores the contribution of impaired insulin signaling in ALD and summarizes the current understanding of the synergistic relationship between alcohol and nutrient excess in promoting hepatic inflammation and disease.
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