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Background: The severity of liver fibrosis is known to be a good indicator for surveillance, and for determining the prognosis and optimal treatment of nonalcoholic fatty liver disease (NAFLD). However, it is virtually impossible to carry out liver biopsies in all NAFLD patients. The purpose of this study was to investigate the clinical usefulness of measuring the platelet count for predicting the severity of liver fibrosis in a large retrospective cohort of Japanese patients with NAFLD., Methods: A total of 1,048 patients with liver-biopsy-confirmed NAFLD seen between 2002 and 2008 were enrolled from nine hepatology centers in Japan. Laboratory evaluations were performed for all patients., Results: A linear decrease of the platelet count with increasing histological severity of hepatic fibrosis was revealed. The area under the receiver operating characteristic curve estimating the diagnostic performance of the platelet count for hepatic fibrosis Stage 3 was 0.774 (optimal cutoff value, 19.2 × 10(4)/μl; sensitivity, 62.7%; specificity, 76.3%), and that for Stage 4 was 0.918 (optimal cutoff value, 15.3 × 10(4)/μl; sensitivity, 80.5%; specificity, 88.8%)., Conclusions: The platelet count may be an ideal biomarker of the severity of fibrosis in NAFLD patients, because it is simple, easy to measure and handle, cost-effective, and accurate for predicting the severity of fibrosis. Furthermore, by using the platelet count cutoff value validated in our multiple large trials, efficient recruitment of NAFLD patients may be facilitated.

Background & Aims: Nonalcoholic steatohepatitis (NASH) can progress to hepatocellular carcinoma (HCC). We aimed to characterize the clinical features of NASH patients with HCC., Methods: In a cross-sectional multicenter study in Japan, we examined 87 patients (median age, 72 years; 62% male) with histologically proven NASH who developed HCC. The clinical data were collected at the time HCC was diagnosed., Results: Obesity (body mass index ≥25 kg/m(2)), diabetes, dyslipidemia, and hypertension were present in 54 (62%), 51 (59%), 24 (28%), and 47 (55%) patients, respectively. In nontumor liver tissues, the degree of fibrosis was stage 1 in 10 patients (11%), stage 2 in 15 (17%), stage 3 in 18 (21%), and stage 4 (ie, liver cirrhosis) in 44 (51%). The prevalence of cirrhosis was significantly lower among male patients (21 of 54, 39%) compared with female patients (23 of 33, 70%) (P = .008)., Conclusions: Most patients with NASH who develop HCC are men; the patients have high rates of obesity, diabetes, and hypertension. Male patients appear to develop HCC at a less advanced stage of liver fibrosis than female patients., (Copyright © 2011 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) have been recognized as a metabolic disorder characterized by fatty accumulation of the liver without alcohol consumption. The progression of the diseases has been considered to link to metabolic syndrome, consisting of obesity, diabetes mellitus(DM), dyslipidemia and hypertension. Glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide(GIP) function as incretin and stimulate glucose-mediated insulin production by pancreatic beta cells. Incretin was also reported to have various kinds of extrapancreatic effects including the regulation of hepatic glucose production, the inhibition of pancreatic exocrine secretion, cardioprotective and cardiotropic effects, the regulation of appetite and satiety, and stimulation of afferent sensory nerves. Therefore, incretins are also expected as therapeutic agents for NFLD and NASH.

Background: The search for effective treatments of non-alcoholic steatohepatitis (NASH), now the most common chronic liver disease in affluent countries, is hindered by a lack of animal models having the range of anthropometric and pathophysiological features as human NASH., Aims: To examine if mice treated with gold thioglucose (GTG) - known to induce lesions in the ventromedial hypothalamus, leading to hyperphagia and obesity - and then fed a high-fat diet (HF) had a comprehensive histological and dysmetabolic phenotype resembling human NASH., Methods: C57BL/6 mice were injected intraperitoneally with GTG and then fed HF for 12 weeks (GTG+HF). The extent of abdominal adiposity was assayed by CT scanning. A glucose tolerance test and an insulin tolerance test were performed to evaluate insulin resistance (IR). Histological, molecular and biochemical analyses were also performed., Results: Gold thioglucose+HF induced dysmetabolism, with hyperphagia, obesity with increased abdominal adiposity, IR and consequent steatohepatitis, with hepatocyte ballooning, Mallory-Denk bodies, perivenular and pericellular fibrosis as seen in adult NASH, paralleled by an increased expression of the profibrogenic factors, transforming growth factor-β1 and TIMP-1. Plasma adiponectin and the expression of adiponectin receptor 1 and receptor 2 were decreased, while PPAR-γ and FAS were increased in the livers of GTG+HF mice. In addition, GTG+HF mice showed glucose intolerance and severe IR., Conclusions: Treatment with GTG and HF diet induce, in mice, a comprehensive model of human NASH, with the full range of dysmetabolic and histological abnormalities., (© 2011 John Wiley & Sons A/S.)

Background: Liver histology is the gold standard for the diagnosis of nonalcoholic steatohepatitis (NASH). Noninvasive, simple, reproducible, and reliable biomarkers are greatly needed to differentiate NASH from nonalcoholic fatty liver disease (NAFLD)., Methods: To construct a scoring system for predicting NASH, 177 Japanese patients with biopsy-proven NAFLD were enrolled. To validate the scoring system, 442 biopsy-proven NAFLD patients from eight hepatology centers in Japan were also enrolled., Results: In the estimation group, 98 (55%) patients had NASH. Serum ferritin [≥200 ng/ml (female) or ≥300 ng/ml (male)], fasting insulin (≥10 μU/ml), and type IV collagen 7S (≥5.0 ng/ml) were selected as independent variables associated with NASH, by multilogistic regression analysis. These three variables were combined in a weighted sum [serum ferritin ≥200 ng/ml (female) or ≥300 ng/ml (male) = 1 point, fasting insulin ≥10 μU/ml = 1 point, and type IV collagen 7S ≥5.0 ng/ml = 2 points] to form an easily calculated composite score for predicting NASH, called the NAFIC score. The area under the receiver operating characteristic (AUROC) curve for predicting NASH was 0.851 in the estimation group and 0.782 in the validation group. The NAFIC AUROC was the greatest among several previously established scoring systems for detecting NASH, but also for predicting severe fibrosis., Conclusions: NAFIC score can predict NASH in Japanese NAFLD patients with sufficient accuracy and simplicity to be considered for clinical use.

Background: Dehydroepiandrosterone (DHEA) is an adrenal hormone reported to prevent body weight gain, diabetes mellitus and atherosclerosis. We hypothesized that DHEA is involved in the pathophysiology of non-alcoholic fatty liver disease (NAFLD) often associated with obesity and insulin resistance. In this study, we aimed to examine the clinical significance of serum DHEA sulfate (DHEAS) in patients with NAFLD., Methods: We determined serum DHEAS, serum alanine aminotransferase (ALT), serum lipids, plasma fasting glucose and insulin levels in 158 Japanese men who had neither viral hepatic diseases nor alcohol intake exceeding 20 g/day. NAFLD was diagnosed by the presence of fatty change of the liver by echotomographic examination., Results: Among the study subjects, 69 were diagnosed as having NAFLD. Their serum DHEAS levels were significantly higher than in 89 subjects without NAFLD. Serum DHEAS levels in 19 NAFLD patients with elevated ALT levels (>40 U/L) were significantly higher than in the other 50 NAFLD patients with normal ALT levels (≤40 U/L). Multivariate regression analysis demonstrated that serum ALT was positively correlated with serum DHEAS, serum triglyceride and body mass index., Conclusion: Serum DHEAS levels are increased in patients with NAFLD with elevated ALT levels. Increased serum DHEAS may be a component of the pathophysiology of NAFLD.

Nonalcoholic fatty liver disease (NAFLD) is a metabolic disorder characterized by fatty accumulation in the liver without alcohol consumption. NAFLD ranges from simple steatosis to nonalcoholic steatohepatitis (NASH), which may progress to end-stage liver disease. The prevalence of NAFLD is rising because of an increasing prevalence of obesity and metabolic syndrome. The progression of these diseases is considered to be related to metabolic syndrome, which is characterized by obesity, glucose impairment, dyslipidemia, hypertension, and adipocytokine impairment. In addition, the pathogenesis of NAFLD/NASH is considered to be multifactorial and complex and is influenced by lifestyle habits, nutritional factors, and genetics. In particular, the PNPLA3 gene has been recently recognized as the most important functional gene polymorphism in the progression of NASH. Disruption in hepatic lipid metabolism is closely related to the development of fatty liver. Accumulation of excess triglycerides (TGs) induces hepatic steatosis. However, TG accumulation itself is not harmful to hepatocytes and may instead act as a protective mechanism against free fatty acid (FFA)-induced lipotoxicity. Excess FFAs also contribute to hepatotoxicity in NAFLD/NASH because oxidation of FFAs in hepatic microsomes generates excessive oxidative stress. Oxidative stress is considered one of the most important pathogenic factors in the development of NASH. Mitochondrial abnormalities, which are frequently observed in NASH-affected livers, are associated with impaired electron transport and result in further oxidative stress formation. The aims of this review are to assess the mechanisms of lipid metabolism and hepatic steatosis, the background of the disease, and the potential molecular mechanisms involved.

Obesity has become a pandemic disease causing a variety of lifestyle-related diseases, such as hypertension, dyslipidemia, diabetes mellitus, liver cirrhosis and hepatocellular carcinoma; therefore obesity has become an important health issue all over the world. Obesity was suggested to cause a chronic liver disease called nonalcoholic steatohepatitis (NASH) and to promote the progression of NASH to liver cirrhosis and hepatocellular carcinoma 30 years ago and this was proven 20 years ago. Today, 1% of the Japanese population is suffering from NASH. Twenty percent of NASH patients, 0.2 million patients, are suggested to develop liver cirrhosis latently in the next decade, and are at a serious risk of developing hepatocellular carcinoma. Indeed, diabetes mellitus has become prevalent among the Japanese population and 10% die from chronic liver disease, but few doctors are able to recognize liver cirrhosis and hepatocellular carcinoma in patients with diabetes mellitus. It is a serious health issue to ignore such risk factors that threaten life in Japan. There are many chronic liver diseases with fatty liver, and nonalcoholic fatty liver disease (NAFLD), a chronic liver disease of unknown etiology, affects 14% of the Japanese population today. As NASH is the most progressive form of this disease, it has become a very important health issue to let doctors know how to recognize patients with NAFLD. In this paper, we discuss how to recognize NAFLD, including NASH, in our outpatient clinic.

Angiosarcoma involving the serous membrane may mimic mesothelioma; therefore, the term "pseudomesotheliomatous angiosarcoma" has been suggested for this entity. However, the pathogenesis of pseudomesotheliomatous angiosarcoma remains unclear. Here, we report an autopsy case of splenic angiosarcoma, which systemically metastasized to the serous membrane of both the peritoneum and pleura, closely resembling a mesothelioma. The spindle-shaped tumor cells exhibited marked invasion of the lymphatic vessels and invaded the serous membrane causing thickening of the fibrous tissues like desmoplastic mesothelioma. In the present case, immunohistochemical staining showed that the tumor expressed not only the endothelial cell markers, such as CD31, vascular endothelial growth factor receptor 3, and podoplanin (D2-40), but also matrix metalloproteinase-1 (also known as collagenase-1), which is known to increase the invasiveness of mesothelioma cells. MMP-1 expression was not observed in the other cases of angiosarcoma, examined. This tumor might systemically metastasize to the serous membrane via the lymphatic route and might generate the fibrous stroma aided by the matrix metalloproteinase-1.

The relevance of estrogen functions in lipid metabolism has been suggested in patients with estrogen-signaling deficiencies. Their importance was further implied by studies in estrogen-deficient mice (ArKO mice), which progressively developed hepatic steatosis. As circulating tumor necrosis factor (TNF)-alpha levels are known to positively correlate with disturbances in lipid metabolism, we investigated the impact of the loss of TNF-alpha signaling on carbohydrate and lipid metabolism in ArKO mice. Histological examinations of the livers of mice at 5 months of age revealed that ArKO male mice lacking the TNF-alpha receptor type 1 (TNFR1) gene (ArKO/TNFR1KO) or both the TNFR 1 and 2 genes (ArKO/TNFR1&2KO) developed more severe hepatic steatosis than ArKO or ArKO/TNFR2KO mice. Serum analyses demonstrated a clear increase in cholesterol and insulin levels in the ArKO/TNFR1KO mice compared with the ArKO mice. Glucose- and insulin-tolerance tests further revealed exacerbation of the systemic insulin resistant phenotype in the ArKO/TNFR1KO mice. Hepatic expression of lipogenic genes including fatty-acid synthase and stearoyl-Coenzyme A desaturase 1 were more markedly upregulated in the ArKO/TNFR1KO mice than the ArKO mice. These findings indicate that under estrogen-deficient physiological conditions, hepatic lipid metabolism would benefit from TNF-alpha mediated signaling via TNFR1., (Copyright (c) 2010 Elsevier B.V. All rights reserved.)

Background: The pathogenesis of non-alcoholic fatty liver disease (NAFLD) is incompletely understood. Kupffer cells (KCs), phagocytic liver-resident macrophages, provide a protective barrier against egress of endotoxin from the portal to the systemic circulation. It is not known if KC phagocytic function is impaired in NAFLD. Super-paramagnetic iron oxide (SPIO) magnetic resonance imaging is a comparative technology dependent on KC phagocytic function., Objective: To evaluate KC uptake function, in patients and experimental animals with NAFLD, using SPIO., Methods: Abdominal CT and histological examination of liver biopsy specimens were used to estimate the degree of steatosis in patients with NAFLD and controls with chronic hepatitis C. SPIO-MRI was then performed in all patients. Normal rats fed a methionine-choline-deficient diet to induce non-alcoholic steatohepatitis (NASH), the more severe stage of NAFLD, and obese, insulin resistant, Zucker fa/fa rats with steatohepatitis, were also studied with SPIO-MRI and analysed for hepatic uptake of fluorescent microbeads. Immunohistochemical analysis evaluated the numbers of KCs in patients and rat livers., Results: Relative signal enhancement (RSE), inversely proportional to KC function, was higher in patients with NAFLD than in controls and with the degree of steatosis on CT. RSE also positively correlated with the degree of steatosis on histology and was similarly higher in rats with induced severe NAFLD (NASH). On immunohistochemistry, defective phagocytic function was the result of reduced phagocytic uptake and not due to reduced KC numbers in rats or patients with NAFLD., Conclusions: KC uptake function is significantly impaired in patients with NAFLD and experimental animals with NASH, worsens with the degree of steatosis and is not due to a reduction of KC numbers.

Objectives: Non-alcoholic steatohepatitis is associated with the deposition of lipid droplets in the liver, and is characterised histologically by the infiltration of inflammatory cells, hepatocellular degeneration and liver fibrosis. Oxidative stress may play an important role in the onset and deterioration of non-alcoholic steatohepatitis. We previously reported that an Eriobotrya japonica seed extract, extracted in 70% ethanol, exhibited antioxidant actions in vitro and in vivo. In this study, we examined the effect of this extract in a rat model of non-alcoholic steatohepatitis., Methods: The seed extract was given in the drinking water to fats being fed a methionine-choline-deficient diet for 15 weeks., Key Findings: Increases in alanine aminotransferase and aspartate aminotransferase levels were significantly inhibited in rats fed the seed extract compared with the group on the diet alone. Formation of fatty droplets in the liver was also inhibited. Antioxidant enzyme activity in liver tissue was higher than in the diet-only group and lipid peroxidation was reduced compared with rats that also received the extract. Expression of 8-hydroxy-2'-deoxyguanosine and 4-hydroxy-2-nonenal was lower in the rats given the seed extract than in the diet-only group. In the former, liver tissue levels of transforming growth factor-beta and collagen were also decreased., Conclusions: Thus, the E. japonica seed extract inhibited fatty liver, inflammation and fibrosis, suggesting its usefulness in the treatment of non-alcoholic steatohepatitis.

Familial hypobetalipoproteinemia (FHBL) is one of the causes of nonalcoholic steatohepatitis (NASH) and a codominant disorder. Patients heterozygous for FHBL may be asymptomatic, although they demonstrate low plasma levels of low-density lipoprotein (LDL) cholesterol and apolipoprotein B. Here we report a nonobese 54-year-old man with decompensated liver cirrhosis who underwent living donor liver transplantation with his son as the donor. Low albuminemia and refractory ascites persisted after transplantation. A biopsy specimen obtained 11 months after liver transplantation revealed severe steatosis and fibrosis, and recurrent NASH was diagnosed on the basis of pathological findings. Both the patient's and donor's laboratory tests demonstrated low LDL cholesterol and apolipoprotein levels. Because mutations in messenger RNAs of microsomal triglyceride transfer protein and apolipoprotein B genes were excluded neither in the recipient nor in the donor, both were clinically diagnosed as being heterozygous for FHBL. We successfully treated the recipient with heterozygous FHBL-induced recurrent NASH after liver transplantation using our diet and exercise programs.

Fascin-1 is an actin-bundling protein localized at the core actin bundles within microvillar projections and filopodial extensions in migrating cells. It is expressed at a low level in normal epithelial cells, but at a high level in tumor cells, indicating its importance in the invasion and motility of tumor cells. In addition, fascin-1 is expressed in human and murine embryos, occurring at high levels especially in developing nervous tissues. In this study, we have investigated the expression patterns of fascin-1 immunohistochemically during the early stages of rat hepatogenesis. A high expression of fascin-1 was detected in the liver bud and hepatoblasts at embryonic day (ED) 10.5, ED11.5, and ED12.5. Expression fell by ED13.5 and was not detectable at ED14.5. These observations demonstrate that the expression of fascin-1 is correlated with the migration activity of hepatoblasts during the early stages of liver development in rats.

Mutations in the small heterodimer partner gene (NR0B2; alias SHP) are associated with high birth weight and mild obesity in Japanese children. SHP mutations may also be associated with later obesity and insulin resistance syndrome that induces diabetes. To investigate this possibility, the prevalence of SHP mutations in Japanese with and without type 2 diabetes mellitus and the functional properties of the mutant proteins were evaluated. Direct sequencing of two exons and flanking sequences of SHP in 805 diabetic patients and 752 non-diabetic controls identified 15 different mutations in 44 subjects, including 6 novel mutations. Functional analyses of the mutant proteins revealed significantly reduced activity of nine of the mutations. Mutations with reduced activity were found in 19 patients (2.4%) in the diabetic group and in 6 subjects (0.8%) in the control group. The frequency difference between DM and control subjects adjusted for sex and age was statistically significant (P=0.029, odds ratio 2.67, 95% CI 1.05-6.81, 1-beta=0.91). We conclude that SHP mutations associated with mild obesity in childhood increase susceptibility to type 2 diabetes in later life in Japanese., ((c) 2008 Wiley-Liss, Inc.)

Estrogen receptor alpha (Esr1) is proposed to play a critical role in the regulation of testicular fluid reabsorption at efferent ductules, and disruption of the Esr1 gene (Esr1(-/-)) resulted in marked dilation of the lumens of efferent ductules. This study was aimed to clarify whether disruption of the gene for aromatase (Ar), an enzyme responsible for estrogen biosynthesis, results in morphological and transcriptional alterations at efferent ductules as observed in Esr1(-/-) mice. Histology demonstrated structural preservation of the ducts in aromatase-deficient (Ar(-/-)) mice. Electron microscopic examinations reveal that endocytic apparatus and tubule-cisternal endoplasmic reticulum are present in non-ciliated cells irrespective of the genotypes. However, electron-dense and acid phosphatase-negative granules and apical tubules, which are components thought to be related to membrane recycling of endosomes, are observed only in wild-type (WT) and Ar(-/-) mice. By contrast, the Golgi complex is highly developed in Esr1(-/-) mice when compared with WT and Ar(-/-) mice. RT-PCR analysis reveals no significant differences in the expression levels of a subset of genes involved in ion transportation. Thus, from the structural and transcriptional points of view, the efferent ductules of Ar(-/-) mice are indistinguishable from those of WT mice. Moreover, data from electron microscopic examinations indicate the possible involvement of Esr1 in the regulation of vesicle recycling processes.

Recent studies of the effectiveness of ursodeoxycholic acid (UDCA) therapy in patients with primary biliary cirrhosis (PBC) reported that UDCA therapy did not necessarily stop the progression of liver fibrosis in all patients, even those with early stage PBC. Thus, there is a need for more effective treatments that could prevent asymptomatic PBC from progressing to the icteric stage. Bezafibrate is effective in approximately two-thirds of non-icteric patients who have not shown a complete response to UDCA. Serum bilirubin, aspartate aminotransferase and gamma-guanosine 5'-triphosphate levelswere significantly lower in patients who responded to additional bezafibrate on univariate analysis. The putative mechanism by which bezafibrate acts in cholestasis is by increasing phospholipid output into bile, which forms micelles with the hydrophobic bile acid that reduces its toxicity.

Background: Lipoprotein lipase (LPL) might play a major role in lipid metabolism by hydrolyzing triglyceride-rich lipoproteins. Decreased LPL activity can trigger early inflammatory responses central to atherosclerosis. However, whether repeated apnea-related hypoxemia influences lipid metabolism in patients with obstructive sleep apnea syndrome (OSAS) remain undefined. This investigation determined whether circulating LPL was influenced by repeated apnea-related hypoxemia, and the effect of nasal continuous positive airway pressure (CPAP) therapy on LPL concentrations in OSAS patients., Methods and Results: The participants of the study were 155 men with OSAS and 39 men without OSAS. Circulating LPL concentrations decreased with the severity of OSAS. They correlated negatively with serum triglyceride, and the linear regression lines between LPL concentrations and triglyceride in OSAS patients were shifted downward compared with those in non-OSAS patients, suggesting that any pathophysiological factor might decrease LPL activity in OSAS patients. Some OSAS patients were subjected to CPAP therapy for 3 months. CPAP therapy increased LPL concentrations and decreased C-reactive protein (CRP) concentrations., Conclusions: The present study suggests that repeated apnea-related hypoxemia might affect lipid metabolism and augment inflammatory responses, and CPAP therapy could be effective to decrease inflammatory responses and ameliorate lipid metabolism in patients with OSAS.

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disorder in Western industrialized countries, affecting 20-40% of the general population. Large population-based surveys in China, Japan, and Korea indicate that the prevalence of NAFLD is now 12% to 24% in population subgroups, depending on age, gender, ethnicity, and location (urban versus rural). There is strong evidence that the prevalence of NAFLD has increased recently in parallel with regional trends in obesity, type 2 diabetes, and metabolic syndrome; and that further increases are likely. The relationship between NAFLD, central obesity, diabetes, and metabolic syndrome is clearly evident in retrospective and prospective Asian studies, but the strength of association with these metabolic risk factors is only appreciated when regional definitions of anthropometry are used. Pathological definition of NAFLD, particularly its activity and the extent of liver fibrosis, requires histological examination, but liver biopsy is often not appropriate in this disorder for logistic reasons. An alternative set of operational definitions is proposed here. Clinicians need guidelines as how best to diagnose and manage NAFLD and its associated metabolic disorders in countries with scant healthcare resources. The Asia-Pacific Working Party (APWP) for NAFLD was convened to collate evidence and deliberate these issues. Draft proposals were presented and discussed at Asia-Pacific Digestive Week at Cebu, Philippines, in late November 2006, and are published separately in this issue of the Journal as an Executive Summary. The present document reviews the reasoning and evidence behind the APWP-NAFLD proposals for definition, assessment, and management of NAFLD in the Asia-Pacific region.

Unlabelled: Nonalcoholic steatohepatitis (NASH) is now the most frequent cause of chronic liver impairment in developed countries and is a suggested causative factor in the development of cryptogenic cirrhosis and hepatocellular carcinoma. At present there is no effective and accepted therapy for NASH. The renin-angiotensin system is involved in hepatic fibrosis through activation of hepatic stellate cells, major fibrogenic cells in the liver. Hepatic stellate cells are activated by liver injury to express excessive matrix proteins and profibrogenic cytokines such as transforming growth factor-beta 1. Medicines that inhibit this pathway may be of therapeutic potential in NASH. Using a methionine-choline-deficient rat model of NASH, we studied the potential utility of an angiotensin II type 1 receptor blocker (ARB), olmesartan, on biochemical, histologic, and antioxidant measures of disease activity. ARB significantly attenuated increases in aspartate aminotransferase, activation of hepatic stellate cells, oxidative stress, expression of transforming growth factor-beta 1, expression of collagen genes, and liver fibrosis., Conclusion: Our observations strongly suggest a potential preventive role for ARB in the progression of nonalcoholic steatohepatitis.

The risk factors and settings for non-alcoholic fatty liver disease (NAFLD) in Asians are reviewed comprehensively. Based particularly on large community-based studies using ultrasonography, case-control series and prospective longitudinal studies, the prevalence of NAFLD in Asia is between 12% and 24%, depending on age, gender, locality and ethnicity. Further, the prevalence in China and Japan has nearly doubled in the last 10-15 years. A detailed analysis of these data shows that NAFLD risk factors for Asians resemble those in the West for age at presentation, prevalence of type 2 diabetes mellitus (T2DM) and hyperlipidemia. The apparent differences in prevalence of central obesity and overall obesity are related to criteria used to define waist circumference and body mass index (BMI), respectively. The strongest associations are with components of the metabolic syndrome, particularly the combined presence of central obesity and obesity. Non-alcoholic fatty liver disease appears to be associated with long-standing insulin resistance and likely represents the hepatic manifestation of metabolic syndrome. Not surprisingly therefore, Asians with NAFLD are at high risk of developing diabetes and cardiovascular disease. Conversely, metabolic syndrome may precede the diagnosis of NAFLD. The increasing prevalence of obesity, coupled with T2DM, dyslipidemia, hypertension and ultimately metabolic syndrome puts more than half the world's population at risk of developing NAFLD/non-alcoholic steatohepatitis/cirrhosis in the coming decades. Public health initiatives are clearly imperative to halt or reverse the global 'diabesity' pandemic, the underlying basis of NAFLD and metabolic syndrome. In addition, a perspective of NAFLD beyond its hepatic consequences is now warranted; this needs to be considered in relation to management guidelines for affected individuals.

Background/aims: The genetic predisposition on the development of nonalcoholic steatohepatitis (NASH) has been poorly understood. A functional polymorphism Val175Met was reported in phosphatidylethanolamine N-methyltransferase (PEMT) that catalyzes the conversion of phosphatidylethanolamine to phosphatidylcholine. The aim of this study was to investigate whether the carriers of Val175Met variant impaired in PEMT activity are more susceptible to NASH., Methods: Blood samples of 107 patients with biopsy-proven NASH and of 150 healthy volunteers were analyzed by the polymerase chain reaction (PCR) and restriction fragment length polymorphism., Results: Val175Met variant allele of the PEMT gene was significantly more frequent in NASH patients than in healthy volunteers (p<0.001), and carriers of Val175Met variant were significantly more frequent in NASH patients than in healthy volunteers (p<0.01). Among NASH patients, body mass index was significantly lower (p<0.05), and non-obese patients were significantly more frequent (p<0.001) in carriers of Val175Met variant than in homozygotes of wild type PEMT., Conclusions: Val175Met variant of PEMT could be a candidate molecule that determines the susceptibility to NASH, because it is more frequently observed in NASH patients and non-obese persons with Val175Met variant of PEMT are facilitated to develop NASH.

Background: Obesity, hypertension, dyslipidemia, and hyperglycemia are prevalent in obstructive sleep apnea syndrome (OSAS). Metabolic syndrome, however, is defined by visceral fat obesity plus at least two of these factors. However, whether OSAS contributes to the development of metabolic syndrome has not been defined. We investigated whether the components of metabolic syndrome were associated with OSAS in nonobese patients., Methods: We investigated the occurrence of hypertension, dyslipidemia, and hyperglycemia in 42 men with OSAS and 52 men without OSAS matched for age, body mass index (BMI), and visceral fat accumulation., Results: Although serum levels of triglycerides, high-density lipoprotein cholesterol, and diastolic BP did not differ significantly between the two groups, fasting blood glucose (111 +/- 6 mg/dL vs 93 +/- 3 mg/dL) [mean +/- SE] and the percentage of hypertensive patients (45% vs 15%) were significantly higher in the group with OSAS. In addition, a significantly higher percentage of patients with OSAS (19% vs 4%) had at least two of the following: hypertension, hyperglycemia, and dyslipidemia. Logistic regression analysis showed that the apnea-hypopnea index value was the predictor of number of metabolic syndrome parameters such as hypertension, hyperglycemia, and dyslipidemia, while BMI and lowest arterial oxygen saturation during sleep did not., Conclusion: Independent of visceral fat obesity, OSAS was associated with hypertension, dyslipidemia, and hyperglycemia. It is possible that OSAS may predispose even nonobese patients to the development of metabolic syndrome.

Obesity is now prevailing worldwide, coincident with the increase of hepatic steatosis. Metabolic syndrome with obesity and hypertension, hyperlipidemia, and impaired glucose tolerance is one of the most frequent life-threatening diseases and non-alcoholic steatohepatitis is believed to be a hepatic expression of this syndrome. Non-alcoholic steatohepatitis is prevalent and well characterized in Caucasians, but little is known about non-alcoholic steatohepatitis in Asia-Oceania. Obesity will be a serious social problem in Asia-Oceania in the next two decades and we need to prevent the increase of this syndrome. Therefore, it is extremely important to know about non-alcoholic steatohepatitis based on racial differences, because this syndrome is likely to be a multi-factorial syndrome resulting from different combinations of susceptibility genes superimposed on different environmental factors. Because hepatic steatosis is the first step in the development of not only metabolic syndrome but also non-alcoholic steatohepatitis, the genetic background of Japanese NASH patients was investigated and a measure to assess fatty acid beta-oxidation in the liver in vivo was developed.

Metabolic syndrome, that is, obesity, hypertension, hyperlipidemia, and insulin resistance with hyperinsulinemia, is a new disease entity prevailing worldwide, and nonalcoholic steatohepatitis (NASH) is believed to be a hepatic expression of this syndrome. NASH is characterized by zone 3-dominant hepatic steatosis with ballooned hepatocytes and Mallory bodies, zone 3 pericellular and perivenular fibrosis with or without bridging fibrosis, and lobular inflammatory cell infiltration. Indeed, 90% of NASH has been revealed to be complicated by visceral obesity, and two-thirds of NASH patients fulfill the criteria of metabolic syndrome. Therefore, a variety of lifestyle-related diseases such as obesity, hypertension, hyperlipidemia, and diabetes mellitus may share the same background. NASH is most prevalent and well characterized in Caucasians; however, little is known about its occurrence in Asia-Oceania, because obesity has not been frequent in countries in these areas. Obesity is expected to become a serious social problem in Asia-Oceania in the next two decades, so we need to prevent a corresponding increase of NASH. For that purpose, we need to know much about not only NASH but also ourselves. To elucidate the status of NASH in Japan, recent progress in the study of NASH in Japan is reviewed in this article.

Steatohepatitis is pathologically characterized by zone 3-dominant hepatic steatosis with ballooned hepatocytes and Mallory bodies, zone 3 pericellular and perivenular fibrosis with or without bridging fibrosis, and lobular inflammatory cell infiltration. Alcoholic hepatitis is a prototype of this syndrome, but a variety of diseases such as obesity, diabetes mellitus, Wilson disease and hepatitis C could reveal very similar pathological changes in some occasions. Therefore, well defined diseases need to be excluded in the process of differential diagnosis of steatohepatitis. Pathways possibly involved in the development of drug-induced steatohepatitis were categorized into four and outlines of the possible mechanisms involved in the development of this syndrome were proposed in this article.

Visceral obesity and insulin resistance are typical clinical features of nonalcoholic steatohepatitis (NASH) characterized by zone 3-dominant hepatic steatosis with ballooned hepatocytes and Mallory bodies, zone 3 pericellular and perivenular fibrosis with or without bridging fibrosis, and lobular inflammatory cell infiltration. Indeed, 90% of NASH revealed to be complicated with visceral obesity, and two thirds of NASH patients fulfill the criteria of metabolic syndrome. Therefore, NASH could be regarded as the hepatic manifestation of metabolic syndrome, and a variety of life-style related diseases such as obesity, hypertension, hyperlipidemia and diabetes mellitus could be used for detecting

We observed postnecrotic tissue remodeling to examine vascularization in adult rat livers. Livers, bone marrow, and peripheral blood from rats at 24 h to 14 days after an injection of dimethylnitrosamine (DMN) were examined by light microscopic, immunohistochemical, and ultrastructural methods. Numerous ED-1 (a marker for rat monocytes/macrophages)-positive round mononuclear cells infiltrated in the necrotic areas at 36 h after DMN treatment. On day 5, when necrotic tissues were removed, some of the cells were transformed from round to spindle in shape. On day 7, these cells were contacted with residual reticulin fibers and became positive for SE-1, a marker of hepatic sinusoidal endothelial cells and Tie-1, an endothelial cell-specific surface receptor, associated with frequent occurrence of ED-1/SE-1 and ED-1/Tie-1 double-positive spindle cells. Ultrastructurally, the spindle cells simultaneously showed phagocytosis and endothelial cell-like morphology. With time necrotic areas diminished, and on day 14, the necrotic tissues were almost replaced by regenerated liver tissues and thin bundles of central-to-central bridging fibrosis. Bone marrow from 12 h to day 2 showed an increase of BrdU-positive mononuclear cells. Some of them were positive for ED-1. The BrdU-labeled and ED-1-positive cells appeared as early as 12 h after DMN injection and reached a peak in number at 36 h. They were similar in structure to ED-1-positive cells in necrotic liver tissues. These findings suggest that round mononuclear ED-1-positive cells proliferate first in bone marrow after DMN treatment, reach necrotic areas of the liver through the circulation, and differentiate to sinusoidal endothelial cells. Namely, hepatic sinusoids in DMN-induced necrotic areas may partly be reorganized possibly by vasculogenesis.

Tamoxifen is an anti-estrogenic agent for the treatment of breast cancer, while exhibiting estrogenic activity in such tissues as the uterus. This study aimed to test whether these opposite properties of tamoxifen in the uterus can be evaluated separately in vivo. We employed two transgenic murine models named, respectively, the ERE-EGFP Ar+/+ mouse and ERE-EGFP Ar-/- mouse. Both types of mice possess an enhanced green fluorescent protein (EGFP) gene regulated by four copies of estrogen response elements (EREs), while the latter lacks a functional aromatase gene, which encodes an enzyme catalyzing conversion of androgens to estrogens. Tamoxifen clearly exhibited estrogenic activity in the uteri of ERE-EGFP Ar-/- mice, as it caused uterine wet weight gain and E2-target gene induction, as 17beta-estradiol (E2) did. However, tamoxifen did not enhance the EGFP expression in ERE-EGFP Ar-/- mice, although E2 induced it significantly. In ERE-EGFP Ar+/+ mice, tamoxifen suppressed the EGFP expression in a time- and dose-dependent manner. Thus, the present study demonstrated that estrogenic and anti-estrogenic activities of tamoxifen can be evaluated by using ERE-EGFP Ar-/- and ERE-EGFP Ar+/+ mice, respectively. Furthermore, these animal models are useful to select and evaluate estrogenic and anti-estrogenic activities of chemical compounds.

Recent progress of studies in NASH displays multi-disciplinary characters of the pathogeneses. Despite these advances, the strategic use of imaging modalities such as CT, US, and MRI, remains a relatively low priority in clinical situations, because these can only visualize the presence of fatty infiltration to the hepatic parenchyma, impossible to figure out the dynamic function of NASH liver. Morphological alteration such as CT value, MR signal intensity and echo-grade do not distinguish NASH from simple fatty liver. In this presentation, from a radiologic viewpoint, we show the feasibility of in vivo fatty acid imaging with (123)I-beta-methyl-p-iodophenyl-pentadecanoic acid (BMIPP). BMIPP is an (123)I labeled fatty acid analog for imaging damaged myocardium, using conventional nuclear imaging equipment. Under normal conditions, the energy source for myocardial utilization is dependent on the beta-oxidation of fatty acids. For energy production in ischemic myocardium, the drastic switch from reduced beta-oxidation of fatty acids to glucose metabolism is well known. BMIPP can detect the area of reduced fatty acids metabolism on myocardial imaging and the data can be converted into semiquantitative analysis. Therefore, we speculate that the use of BMIPP to in vivo hepatic imaging in NASH could highlight a lot of matters of NASH. Details of this presentation include: (1) Hepatic imaging with BMIPP; (2) Clearance of BMIPP from NASH liver; (3) semiquantitative analysis of hepatic BMIPP clearance and clinical features of NASH; (4) Profiles of NASH categorized by BMIPP imaging and (5) Preliminary data of BMIPP clearance in patients with Tamoxifen-induced NASH. The core of our stance in this presentation is searching for valuable advice on clinical use of BMIPP in patients with NASH from specialists in the field of HEPATOLOGY.

Oral administration of tamoxifen, an endocrine therapy for breast cancer, often induces hepatic steatosis (THS, tamoxifen-induced hepatic steatosis) as a complication, which can progress to non-alcoholic steatohepatitis (NASH). The development of this complication is strongly associated with three clinical risk factors; specifically, insulin resistance, central obesity, and hypertriglyceridemia, however a genetic predisposition to THS has yet to be investigated. The aim of this study is to determine whether genetic polymorphism of the P450c17alpha enzyme coded for by the CYP17 gene, responsible for regulating serum estrogen, has an association with THS. After obtaining informed consent from 180 eligible breast cancer patients treated with tamoxifen, DNA was collected and analyzed by restriction fragment length polymorphism assay and classified into alleles defined as A1 and A2. The absence or presence and extent of THS was evaluated by calculating the liver/spleen (L/S) ratio based on Hounsfield units with a CT scanner. Administration of tamoxifen led to THS (L/S ratio <0.9) in 57 (31.7%) of 180 patients while the remaining 123 (68.3%) patients did not develop THS. A significant difference in the distribution of CYP17 genotypes was observed between patients who developed THS and those who did not (P=0.021). A significantly higher frequency of the A2 allele was seen in the THS group (odds ratio, 1.90; 95% confidence interval, 1.21-2.99). Our study provides the first evidence that CYP17 polymorphism participates in the development of THS, and sheds light on the genetic causes of this side effect and genetic differences between tamoxifen-treated individuals.

Aromatase is an enzyme responsible for the conversion of androgen to estrogen. We genetically engineered an aromatase-deficient mouse (Ar(-/-) mouse) to express an enhanced green fluorescent protein (EGFP) gene in the uterus, ovary, adrenal and pituitary glands in a 17beta-estradiol (E2)-inducible manner. In this study, we analyzed estrogenic activities of diethylstilbestrol, genistein, daidzein and E2 in the Ar(-/-) tissues by using the EGFP expression as an indicator. These analyses manifest differential responses of the tissues to the compounds and also allow to determine the relative estrogenic potency of the compounds to that of E2 in vivo. Furthermore, analyses of the EGFP expression in ERalpha-deficient mice suggested that the expression is ERalpha-dependent in the uterus and pituitary gland. In conclusion, the Ar(-/-) mouse carrying the E2-inducible EGFP gene is a valuable tool for quantitative analyses of natural and synthetic estrogenic compounds in vivo.

Background: Obesity, hypertriglyceridemia, and diabetes have been reported as frequent complications observed in patients with nonalcoholic steatohepatitis (NASH) in Western countries. The aim of this study was to investigate the genetic predisposition on NASH pathogenesis in the Japanese population., Methods: Genotypes of two previously described functional polymorphisms-beta3-adrenergic receptor 190 T/A polymorphism, which results in Trp64Arg (W64R) amino acid replacement, and interleukin-1beta-511 T/C polymorphism in the promoter sequence-were determined in 63 Japanese NASH patients and 100 healthy volunteers using polymerase chain reaction and restriction fragment length polymorphism., Results: beta3-adrenergic receptor R allele frequency and the R/- (W/R and R/R) genotype frequency were significantly higher in NASH patients than those in control subjects. Interleukin-1beta-511 T allele frequency and the T/T genotype frequency were significantly higher in NASH patients than those in control subjects. Obesity, hypertriglyceridemia, and hyperinsulinemia were associated with NASH patients with the R/- genotype, whereas an increase in fasting plasma glucose level and a decrease in insulinogenic index were associated with NASH patients with the W/W genotype., Conclusion: This study confirmed the contribution of obesity, glucose intolerance, and hypertriglyceridemia to NASH development in the Japanese population. In addition to these factors, genetic predispositions to obesity and inflammation in the Japanese population were shown to contribute much to the development of NASH.

Background/aims: The pathogenesis of non-alcoholic steatohepatitis (NASH) is poorly understood. The aim of this study was to examine genetic influences on NASH pathogenesis., Methods: Blood samples from 63 patients with biopsy-proven NASH and 150 healthy controls were analyzed by the polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). Two functional polymorphisms were studied: the -493 G/T polymorphism in the promoter of microsomal triglyceride transfer protein (MTP) and the 1183 T/C polymorphism in the mitochondrial targeting sequence of manganese superoxide dismutase (MnSOD)., Results: NASH patients had a much higher incidence of the MTP gene G allele (P=0.001) and of the G/G genotype (P=0.002) compared to the controls. Fat occupied more area in liver lobules and the stage of NASH was advanced in patients with the G/G-genotype than in patients with G/T-genotype (P=0.04). NASH patients also had a higher incidence of the MnSOD T/T genotype (P=0.016)., Conclusions: The G allele in the MTP promoter leads to decreased MTP transcription, less export of triglyceride from hepatocytes, and greater intracellular triglyceride accumulation. The T allele in MnSOD mitochondrial targeting sequence leads to less transport of MnSOD to the mitochondria. Therefore, functional polymorphisms in MTP and MnSOD may be involved in determining susceptibility of NASH.

Aromatase is an enzyme that converts androgen to estrogen in the gonads and also at extragonadal sites, including the brain. In this study we developed a transgenic mouse that carries an enhanced green fluorescent protein (EGFP) gene inducible by estrogen through an estrogen response element to facilitate detection of estrogen actions in vivo. The expression of EGFP in aromatase-deficient (Ar(-/-)) female mice was significantly suppressed at the pituitary gland, ovary, uterus, and gonadal fat pad and was induced by dietary 17beta-estradiol to wild-type (Ar(+/+)) levels or higher. These results demonstrate that the expression of the EGFP gene is tissue selective and estrogen dependent in vivo. Employing this transgenic mouse, we examined whether estrogen synthesis in the extragonadal sites is necessary for reproduction in female mice. When ovaries of Ar(-/-) mice were replaced with Ar(+/+) ovaries, a significant induction of EGFP expression in the pituitary gland and uterus was observed. Histological examinations showed the presence of antral follicles in the replaced ovaries, indicating that the transplants are functional in Ar(-/-) mice. After crossing with males, three of 10 Ar(-/-)females with Ar(+/+) ovaries became pregnant and fed their pups. Collectively, these observations indicate that estrogen synthesis in the ovary is sufficient for supporting female reproduction, and that infertility of Ar(-/-) females is primarily due to a defect in estrogen synthesis in the ovary.

In our previous study, we demonstrated that the radioresistance of the human osteosarcoma cell line HS-Os-1, was considered to arise, at least in part, from the low level of ROS formation following irradiation, which in turn may have resulted from the strong scavenging ability of the cells for free radicals, including hydroxyl radicals. Following the study, we found that addition of 1 or 10 mM hydrogen peroxide induced ROS formation, oxidative DNA damage, dysfunction of the mitochondrial membrane potential, and early apoptotic changes in the human osteosarcoma cell line HS-Os-1. We therefore speculated that combined use of irradiation and hydrogen peroxide might exert an additive effect for apoptotic-resistant tumors such as the human osteosarcoma cell line HS-Os-1, in terms of preservation of the radiation-induced hydroxyl radical production supported by the intracellular ROS formation that is induced by exogenous hydrogen peroxide addition. Therefore, in this study, we examined the effect of various doses of irradiation on the existence of 0.1 mM hydrogen peroxide in the culture medium. We found that irradiation with 10 or 20 Gy, under the condition of the presence of 0.1 mM hydrogen peroxide, induced ROS formation, oxidative DNA damage, dysfunction of the mitochondrial membrane potential, and early apoptotic changes in the human osteosarcoma cell line HS-Os-1, though ROS formation and oxidative DNA damage were scarcely seen in response to irradiation of up to 30 Gy, as was shown in our previous study. We therefore concluded that the combined modality of irradiation and such a low concentration of hydrogen peroxide (0.1 mM) is potentially applicable in clinical radiotherapy for many kinds of apoptotic-resistant neoplasms in terms of achieving both local control and improving survival benefit of patients.

One-third of the breast cancer patients who underwent tamoxifen intake showed less than 0.9 of their liver/spleen CT (computed tomography) ratio on their annual CT study, and were diagnosed as having fatty liver (hepatic steatosis). Among them, patients who showed a lower liver/spleen CT ratio of less than 0.5 were recommended to undergo needle biopsy of the liver in order to obtain histopathological confirmation of non-alcoholic steatohepatitis (NASH), with 15 patients undergoing needle biopsy of the liver. As a result, 14 out of the 15 patients were diagnosed as having NASH, and these patients were additionally administered bezafibrate in order to prevent possible progressive changes of NASH into liver cirrhosis. In this study, we show the changes of follow-up CT findings of 6 patients with histopathologically-proven NASH who continued to undergo bezafibrate intake after the diagnosis of NASH. Two patients showed almost complete improvement as indicated by the liver/spleen CT ratio several months after completion of a tamoxifen intake of 5 years, and another 3 showed partial improvement on their liver/spleen CT ratio by bezafibrate intake in spite of continuing tamoxifen intake. Another patient with diabetes mellitus (type II) showed a continually decreasing liver/spleen CT ratio during adjuvant tamoxifen in spite of bezafibrate intake. Therefore, we concluded that the progression of NASH could be prevented by bezafibrate without any interruption of adjuvant tamoxifen treatment. For patients with diabetes mellitus, critical follow-up using CT study and laboratory tests is considered essential.

In liver injuries, the quiescent hepatic stellate cells (HSCs) promptly change to activated HSCs, which are easily identified by the intense immunoreactivity for alpha-smooth muscle actin. However, reproducible markers for quiescent HSCs in formalin-fixed, paraffin-embedded liver tissue sections have not yet been reported. We immunohistochemically examined the expression of vinculin, one major protein of dense plaques, on cultured LI90 cells and on HSCs in normal and diseased human and rat livers. In cultured LI90 cells, vinculin appeared as small linear patches. Although vinculin was consistently negative in the routine liver tissue sections, an antigen retrieval technique using microwave oven heating yielded excellent effects. Using this technique, the formalin-fixed, paraffin-embedded human and rat normal liver tissue sections showed the vinculin immunoreactivity along the sinusoidal wall. Immunoelectron microscopic observation of hepatic parenchyma demonstrated that the vinculin was exclusively expressed in quiescent HSCs. In fetal rat livers, vinculin-positive quiescent HSCs gradually increased in number with gestation. In diseased livers the activated HSCs showed more intense immunoreaction for vinculin. These results indicate that, using microwave pretreatment, vinculin is expressed in quiescent and activated HSCs in routinely processed liver tissue sections. It could allow us to evaluate the development and distribution of quiescent HSCs and to examine the relationship between quiescent and activated HSCs.

The unique inborn hypertriglyceridemia seen in FLS (fatty liver Shionogi) mice was relieved by the administration of purified apolipoprotein (apo) C-II. Lipoprotein lipase (LPL) and its cofactor, apoC-II, play a pivotal role in VLDL metabolism. Therefore, we investigated the genetic background involved in this hypertriglyceridemia. Plasma levels of TG and total cholesterol as well as LPL activity were measured in male FLS mice and C57/BL6J mice. Agarose gel electrophoresis and fast protein liquid chromatography were used to analyze the lipoprotein profile. A cross experiment was done to determine the genetic background of hypertriglyceridemia observed in FLS mice. cDNA sequences of apoC-II and apoC-III of FLS mice were determined. Prealpha-lipoprotein was the predominant lipoprotein class in FLS mouse plasma. LPL activity remained in the range observed in C57/BL6J mice, and purified apoC-II transiently relieved FLS mice from hypertriglyceridemia. Prealpha-lipoproteinemia was inherited in an autosomal recessive manner. ApoC-III appeared to be a causal factor for this unique hypertriglyceridemia. Microsatellite analysis, however, revealed that the responsible chromosome was not 7; rather, apoC-III mapped onto chromosome 9. Therefore, we suggest apoC-III as a candidate causative factor for the hypertriglyceridemia observed in FLS mice because an excessive amount of apoC-III attenuates LPL activity in vivo and in vitro.

The fatty liver Shionogi (FLS) mouse is an inbred strain that develops spontaneous fatty liver (hepatic steatosis) chronically without obesity. Here, we reported that the mice develop spontaneous hepatocellular tumors with high incidences. The mice with age of over 1 year frequently developed whitish protuberant nodules in the livers, which were histologically diagnosed as hepatocellular adenoma and/or carcinoma (HCC). An incidence of HCC was 12/30 (40%) in males at 15-16 months of age, while in females that was 0/36 at 13-16 months and 4/42 (9.5%) at 20-24 months. Furthermore, histological examinations showed that after 2-4 months of age mononuclear cell infiltration and clusters of foamy cells appear in the fatty liver with elevated serum alanine aminotransferase, suggesting presence of inflammatory responses and liver injury. These observations show that the FLS mice develop hepatocellular tumors following steatohepatitis. The mouse might be a good animal model for investigating liver tumor and non-alcoholic steatohepatitis.