Regression of hepatic fibrosis after pharmacological therapy for nonalcoholic steatohepatitis

The global incidence of nonalcoholic fatty liver disease(NAFLD)is escalating considerably.NAFLD covers a range of liver conditions from simple steatosis to the more severe form known as nonalcoholic steatohepatitis,which involves chronic liver inflammation and the transformation of hepatic stellate cells into myofibroblasts that generate excess extracellular matrix,leading to fibrosis.Hepatocyte ballooning is a key catalyst for fibrosis progression,potentially advancing to cirrhosis and its decompensated state.Fibrosis is a critical prognostic factor for outcomes in patients with NAFLD;therefore,those with substantial fibrosis require timely intervention.Although liver biopsy is the most reliable method for fibrosis detection,it is associated with certain risks and limitations,particularly in routine screening.Consequently,various noninvasive diagnostic techniques have been introduced.This review examines the increasing prevalence of NAFLD,evaluates the noninvasive diagnostic techniques for fibrosis,and assesses their efficacy in staging the disease.In addition,it critically appraises current and emerging antifibrotic therapies,focusing on their mechanisms,efficacy,and potential in reversing fibrosis.This review underscores the urgent need for effective therapeutic strategies,given the dire consequences of advanced fibrosis.

Dynamic alterations in the gut microbiota and metabolome during the development of methionine-choline-deficient diet-induced nonalcoholic steatohepatitis

AIM To investigate changes in gut microbiota and metabolism during nonalcoholic steatohepatitis(NASH) development in mice fed a methionine-choline-deficient(MCD) diet. METHODS Twenty-four male C57 BL/6 J mice were equally divided into four groups and fed a methionine-choline-sufficient diet for 2 wk(Control 2 w group,n = 6) or 4 wk(Control 4 w group,n = 6) or the MCD diet for 2 wk(MCD 2 w group,n = 6) or 4 wk(MCD 4 w group,n = 6). Liver injury,fibrosis,and intestinal barrier function were evaluated after 2 and 4 wk of feeding. The fecal microbiome and metabolome were studied using 16 s r RNA deep sequencing and gas chromatography-mass spectrometry. RESULTS The mice fed the MCD diet presented with simple hepatic steatosis and slight intestinal barrier deterioration after 2 wk. After 4 wk of feeding with the MCD diet,however,the mice developed prominent NASH with liver fibrosis,and the intestinal barrier was more impaired. Compared with the control diet,the MCD diet induced gradual gut microbiota dysbiosis,as evidenced by a marked decrease in the abundance of Alistipes and the(Eubacterium) coprostanoligenes group(P < 0.001 and P < 0.05,respectively) and a significant increase in Ruminococcaceae UCG 014 abundance(P < 0.05) after 2 wk. At 4 wk,the MCD diet significantly reduced the promising probiotic Bifidobacterium levels and markedly promoted Bacteroides abundance(P < 0.05,and P < 0.01,respectively). The fecal metabolomic profile was also substantially altered by the MCD diet: At 2 wk,arachidic acid,hexadecane,palmitic acid,and tetracosane were selected as potential biomarkers that were significantly different in the corresponding control group,and at 4 wk,cholic acid,cholesterol,arachidic acid,tetracosane,and stearic acid were selected. CONCLUSION The MCD diet induced persistent alterations in the gut microbiota and metabolome.

Effects of salvianolic acid B on liver mitochondria of rats with nonalcoholic steatohepatitis

AIM: To investigate the effects of salvianolic acid B(Sal B) on the morphological characteristics and functions of liver mitochondria of rats with nonalcoholic steatohepatitis(NASH).METHODS: A total of 60 male Sprague-Dawley rats were randomly divided into three groups:(1) a normal group fed a normal diet;(2) an NASH model group; and(3) a Sal B-treated group fed a high-fat diet. Two rats from each group were executed at the end of the 12 th week to detect pathological changes. The rats in the Sal B-treated group were gavaged with 20 m L/kg Sal B(1 mg/m L) daily. The model group received an equal volume of distilled water as a control. At the end of the 24 th weekend, the remaining rats were executed. Serum biochemical parameters and liver histological characteristics were observed. Malondialdehyde(MDA) and superoxide dismutase(SOD) in the liver were determined. Protein expression of Cyt C and caspase-3 was determined by immunohistochemistry. The m RNA transcripts of mitofusin-2(Mfn2) and NF-κB in the liver tissue were detected by real-time PCR. Mitochondrial membrane potential was detected using a fluorescence spectrophotometer. Mitochondrial respiratory function was detected using a Clark oxygen electrode.RESULTS: The model group showed significantly higher ALT, AST, TG, TC and MDA but significantly lower SOD than the normal group. In the model group,the histological characteristics of inflammation and steatosis were also evident; mitochondrial swelling and crest were shortened or even disappeared. Cyt C(18.46 ± 1.21 vs 60.01 ± 3.43, P < 0.01) and caspase-3 protein expression(30.26 ± 2.56 vs 83.31 ± 5.12, P < 0.01) increased significantly. The m RNA expression of NF-κB increased(0.81 ± 0.02 vs 0.91 ± 0.03, P < 0.05), whereas the m RNA expression of Mfn2 decreased(1.65 ± 0.31 vs 0.83 ± 0.16, P < 0.05). Mitochondrial membrane potential also decreased and breathing of rats was weakened. Steatosis and inflammation degrees in the treatment group were significantly alleviated compared with those of the model group. In the treatment group, mitochondrial swelling was alleviated. Cyt C(60.01 ± 3.43 vs 30.52 ± 2.01, P < 0.01) and caspase-3 protein expression(83.31 ± 5.12 vs 40.15 ± 3.26, P < 0.01) significantly decreased. The m RNA expression of NF-κB also decreased(0.91 ± 0.03 vs 0.74 ± 0.02, P < 0.01), whereas the m RNA expression of Mfn2 increased(0.83 ± 0.16 vs 1.35 ± 0.23, P < 0.01). Mitochondrial membrane potential increased and respiratory function was enhanced. CONCLUSION: Sal B can treat NASH by protecting the morphological characteristics and functions of liver mitochondria, regulating lipid metabolism, controlling oxidative stress and lipid peroxidation and inhibiting apoptosis.

Shear wave velocity is a useful marker for managing nonalcoholic steatohepatitis

AIM:To investigate whether a noninvasive measurement of tissue strain has a potential usefulness for management of nonalcoholic steatohepatitis(NASH).METHODS:In total 26 patients,23 NASHs and 3 normal controls were enrolled in this study.NASH was staged based on Brunt criterion.At a region of interest(ROI),a shear wave was evoked by implementing an acoustic radiation force impulse(ARFI),and the propagation velocity was quantif ied.RESULTS:Shear wave velocity(SWV) could be reproducibly quantified at all ROIs in all subjects except for 4 NASH cases,in which a reliable SWV value was not calculated at several ROIs.An average SWV of 1.34 ± 0.26 m/s in fibrous stage 0-1 was significantly slower than 2.20 ± 0.74 m/s and 2.90 ± 1.01 m/s in stages 3 and 4,respectively,but was not significantly different from 1.79 ± 0.78 m/s in stage 2.When a cutoff value was set at 1.47 m/s,receiver operating characteristic analysis showed significance to dissociate stages 3 and 4 from stage 0-1(P=0.0092) with sensitivity,specificity and area under curve of 100%,75% and 94.2%,respectively.In addition,the correlation between SWV and hyaluronic acid was significant(P<0.0001),while a tendency toward negative correlation was observed with serum albumin(P=0.053).CONCLUSION:The clinical implementation of ARFI provides noninvasive repeated evaluations of liver stiffness at an arbitrary position,which has the potential to shed new light on NASH management.

Glucagon-like peptide-1 analogue prevents nonalcoholic steatohepatitis in non-obese mice

AIM: To investigate whether a glucagon-like peptide-1(GLP-1) analogue inhibits nonalcoholic steatohepatitis(NASH), which is being increasingly recognized in Asia, in non-obese mice. METHODS: A methionine-choline-deficient diet(MCD) along with exendin-4(20 μg/kg per day, ip), a GLP-1 analogue, or saline was administered to male db/db mice(non-obese NASH model). Four or eight weeks after commencement of the diet, the mice were sacrificed and their livers were excised. The excised livers were examined by histochemistry for evidence of hepatic steatosis and inflammation. Hepatic triglyceride(TG) and free fatty acid(FFA) content was measured, and the expression of hepatic fat metabolism- and inflammation-related genes was evaluated. Oxidative stress-related parameters and macrophage recruitment were also examined using immunohistochemistry.RESULTS: Four weeks of MCD feeding induced hepatic steatosis and inflammation and increased the hepatic TG and FFA content. The expression of fattyacid transport protein 4(FATP4), a hepatic FFA influxrelated gene; macrophage recruitment; and the level of malondialdehyde(MDA), an oxidative stress marker, were significantly augmented by a 4-wk MCD. The levels of hepatic sterol regulatory element-binding protein-1c(SREBP-1c) m RNA(lipogenesis-related gene) and acyl-coenzyme A oxidase 1(ACOX1) m RNA(β-oxidation-related gene) had decreased at 4 wk and further decreased at 8 wk. However, the level of microsomal triglyceride transfer protein m RNA(a lipid excretion-related gene) remained unchanged. The administration of exendin-4 significantly attenuated the MCD-induced increase in hepatic steatosis, hepatic TG and FFA content, and FATP4 expression as well as the MCD-induced augmentation of hepatic inflammation, macrophage recruitment, and MDA levels. Additionally, it further decreased the hepatic SREBP-1c level and alleviated the MCD-mediated inhibition of the ACOX1 m RNA level. CONCLUSION: These results suggest that GLP-1 inhibits hepatic steatosis and inflammation through the inhibition of hepatic FFA influx and oxidative stress in a non-obese NASH model.

Nonalcoholic steatohepatitis-associated hepatocellular carcinoma:Our case series and literature review

Recently,nonalcoholic steatohepatitis(NASH) has been considered to be another cause of liver cirrhosis and hepatocellular carcinoma(HCC).The natural history and prognosis of NASH are controversial.Accordingly,we assessed the clinicopathological features of NASH-associated HCC in our experience and reviewed the literature of NASH-associated HCC.We experienced 11 patients with NASH-associated HCC(6 male,5 female;mean age 73.8 ± 4.9 years) who received curative treatments.Most(91%) patients had been diagnosed with obesity,diabetes,hypertension,or dyslipidemia.Seven patients(64%) also had a non-cirrhotic liver.The recurrence-free survival rates at 1,3 and 5 years were 72%,60%,and 60%.We also summarized and reviewed 94 cases of NASH-associated HCC which were reported in the literature(64 male;mean age 66 years).The majority of patients(68%) were obese,66% of patients had diabetes,and 24% had dyslipidemia.Furthermore,26% of the HCCs arose from the non-cirrhotic liver.In conclusion,patients with non-cirrhotic NASH may be a high-risk group for HCC,and regular surveillance for HCC is necessary in non-cirrhotic NASH patients as well as cirrhotic patients.

Animal models of nonalcoholic fatty liver disease/nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease(NAFLD) is a condition in which excess fat accumulates in the liver of a patient without a history of alcohol abuse.Nonalcoholic steatohepatitis(NASH),a severe form of NAFLD,can progress to liver cirrhosis and hepatocellular carcinoma.NAFLD is regarded as a hepatic manifestation of metabolic syndrome and incidence has been increasing worldwide in line with the increased prevalence of obesity,type 2 diabetes,and hyperlipemia.Animal models of NAFLD/NASH give crucial information,not only in elucidating pathogenesis of NAFLD/NASH but also in examining therapeutic effects of various agents.An ideal model of NAFLD/NASH should correctly reflect both hepatic histopathology and pathophysiology of human NAFLD/NASH.Animal models of NAFLD/NASH are divided into genetic,dietary,and combination models.In this paper,we review commonly used animal models of NAFLD/NASH referring to their advantages and disadvantages.

Limitations of liver biopsy and non-invasive diagnostic tests for the diagnosis of nonalcoholic fatty liver disease/nonalcoholic steatohepatitis

It is estimated that 30% of the adult population in Japan is affected by nonalcoholic fatty liver disease (NAFLD). Fatty changes of the liver are generally diagnosed using imaging methods such as abdominal ultrasonography (US) and computed tomography (CT), but the sensitivity of these imaging techniques is low in cases of mild steatosis. Alanine aminotransferase levels may be normal in some of these patients, warranting the necessity to establish a set of parameters useful for detecting NAFLD, and the more severe form of the disease, nonalcoholic steatohepatitis (NASH). Although liver biopsy is currently the gold standard for diagnosing progressive NASH, it has many drawbacks, such as sampling error, cost, and risk of complications. Furthermore, it is not realistic to perform liver biopsies on all NAFLD patients. Diagnosis of NASH using various biomarkers, scoring systems and imaging methods, such as elastography, has recently been attempted. The NAFIC score, calculated from the levels of ferritin, fasting insulin, and type IV collagen 7S, is useful for the diagnosis of NASH, while the NAFLD fibrosis score and the FIB-4 index are useful for excluding NASH in cases of advanced fibrosis. This article reviews the limitations and merits of liver biopsy and noninvasive diagnostic tests in the diagnosis of NAFLD/NASH.

Nonalcoholic steatohepatitis severity is defined by a failure in compensatory antioxidant capacity in the setting of mitochondrial dysfunction

AIM To comprehensively evaluate mitochondrial(dys) function in preclinical models of nonalcoholic steatohepatitis(NASH).METHODS We utilized two readily available mouse models of nonalcoholic fatty liver disease(NAFLD) with or without progressive fibrosis: Lep^(ob)/Lep^(ob)(ob/ob) and FATZO mice on high trans-fat, high fructose and high cholesterol(AMLN) diet. Presence of NASH was assessed using immunohistochemical and pathological techniques, and gene expression profiling. Morphological features of mitochondria were assessed via transmission electron microscopy and immunofluorescence, and function was assessed by measuring oxidative capacity in primary hepatocytes, and respiratory control and proton leak in isolated mitochondria. Oxidative stress was measured by assessing activity and/or expression levels of Nrf1, Sod1, Sod2, catalase and 8-OHdG. RESULTS When challenged with AMLN diet for 12 wk, ob/ob and FATZO mice developed steatohepatitis in the presence of obesity and hyperinsulinemia. NASH development was associated with hepatic mitochondrial abnormalities, similar to those previously observed in humans, including mitochondrial accumulation and increased proton leak. AMLN diet also resulted in increased numbers of fragmented mitochondria in both strains of mice. Despite similar mitochondrial phenotypes, we found that ob/ob mice developed more advanced hepatic fibrosis. Activity of superoxide dismutase(SOD) was increased in ob/ob AMLN mice, whereas FATZO mice displayed increased catalase activity, irrespective of diet. Furthermore, 8-OHd G, a marker of oxidative DNA damage, was significantly increased in ob/ob AMLN mice compared to FATZO AMLN mice. Therefore, antioxidant capacity reflected as the ratio of catalase:SOD activity was similar between FATZO and C57 BL6 J control mice, but significantly perturbed in ob/ob mice. CONCLUSION Oxidative stress, and/or the capacity to compensate for increased oxidative stress, in the setting of mitochondrial dysfunction, is a key factor for development of hepatic injury and fibrosis in these mouse models.

Histopathology of nonalcoholic fatty liver disease/nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease(NAFLD), a hepatic manifestation of metabolic syndrome, is the most common chronic liver disease, and the prevalence is rapidly increasing worldwide. Nonalcoholic steatohepatitis(NASH), the severe form of NAFLD, can progress to liver cirrhosis and hepatocellular carcinoma(HCC). Although noninvasive clinical scores and image-based diagnosis for NAFLD have improved, histopathological evaluation of biopsy specimens remains the gold standard for diagnosing NAFLD/NASH. Steatosis, lobular inflammation, and hepatocellular ballooning are all necessary components for the diagnosis of NASH; fibrosis is also typically observed. Other histopathological abnormalities commonly observed in NASH include hepatocellular glycogenated nuclei, lipogranulomas, and acidophil bodies. The characteristics of pediatric NAFLD/NASH differ from adult NAFLD/NASH. Specifically, steatosis and portal inflammation are more severe in pediatric NAFLD, while intralobular inflammation and perisinusoidal fibrosis are milder. Although interobserver agreement for evaluating the extent of steatosis and fibrosis is high, agreement is low for intralobular and portal inflammation. A recently reported histological variant of HCC, steatohepatitic HCC(SH-HCC), showsfeatures that resemble non-neoplastic steatohepatitis,and is thought to be strongly associated with underlying NASH.In this report,we review the histopathological features of NAFLD/NASH.

Nonalcoholic steatohepatitis in nonalcoholic fatty liver disease patients of Bangladesh

AIM: To explore the prevalence and risk factors for nonalcoholic steatohepatitis (NASH) in nonalcoholic fatty liver disease (NAFLD) patients. METHODS: We have included 493 patients with sonographic evidence of a fatty change, and 177 of these individuals were evaluated and confirmed after liver biopsy. The exclusion criteria consisted of significant alcohol abuse (【 20 g daily), evidence of hepatitis B and C, evidence of drug-induced fatty liver disease and other specific liver diseases such as hemochromatosis, Wilson’s disease or autoimmune liver disease. The patients were assessed for metabolic syndrome, and biochemical, anthropometric and histopathological evaluations were carried out. The degree of disease activity in the NAFLD patients was evaluated using the NAFLD Activity Score. The data were analyzed by SPSS, version 16.0. RESULTS: Females predominated among the study participants (250, 57.0%), and the mean age was 40.8 ± 10.2 years. The numbers of overweight, obeseⅠ and obese Ⅱ patients were 58 (13.2%), 237 (53.9%) and 93 (21.2%), respectively. However, there were 422 (96.2%) centrally obese patients. NASH was absent in 10 (5.6%) cases, borderline in 92 (52.6%) cases and present in 75 (42.4%) cases. The presence of diabetes could significantly (P = 0.001) differentiate NASH from simple steatosis. The following parameters did not influence the development of NASH: age, sex, basal metabolic index, waist circumference, serum high-density lipoprotein, triglyceride, insulin resistance index, hypertension and metabolic syndrome. The serum gammaglutamyl transpeptidase (GGT) level was significantly higher (P = 0.05, 51.7 ± 32.8 and 40.4 ± 22.6 U/L) in the NASH patients, with a sensitivity of 45% and a specificity of only 68%. The serum alanine aminotransferase and aspartate aminotransferase levels were not able to predict NASH. CONCLUSION: Females were the predominant sufferers of NAFLD in Bangladesh. The prevalence of NASH was high. Diabetes was found to be the main culprit in developing NASH. GGT was the only biochemical marker of NASH. We recommend liver biopsy in NAFLD patients who have diabetes and elevated GGT.

A rabbit model of pediatric nonalcoholic steatohepatitis: The role of adiponectin

AIM： To create a rabbit model of pediatric nonalcoholic steatohepatitis （NASH） and to evaluate the role of adiponectin in the process. METHODS： Thirty-two specific pathogen-free male New Zealand rabbits were divided randomly into three groups： （1） the normal control group （n = 10） was fed with standard diet for 12 wk; （2） the model group A （n = 11）; and （3） model group B （n = 11） were fed with a highfat diet （standard diet ＋ 10% lard ＋ 2% cholesterol） for 8 and 12 wk, respectively. Hepatic histological changes were observed and biochemical parameters as well as serum levels of adiponectin, interleukin （IL）-6, IL-10 and tumor necrosis factor （TNF）-α were measured. RESULTS： Typical histological hepatic lesions of NASH were observed in both model groups described as liver steatosis, liver inflammatory infiltration, cytologic ballooning, perisinusoidal fibrosis and overall fibrosis. Compared with the normal control group, there were significant increases in model groups A and B in weight gain （1097.2 ± 72.3, 1360.5± 107.6 vs 928.0 ±58.1, P 〈 0.05, P 〈 0.01）, liver weight （93.81±6.64, 104.6±4.42 vs 54.4±1.71, P 〈 0.01）, Lg （ALT） （1.9±0.29, 1.84± 0.28 vs 1.60±0.17, P 〈 0.01）, and Lg （TG） （1.03 ±0.24, 1.16 ±0.33 vs 0.00 ±0.16, P 〈 0.01）. Weight gain was much more in model group B than in model group A （1360.5± 107.6 vs 1097.2 ±72.3, P 〈 0.05）. But, there was no significant difference between the two groups concerning the other indexes. Pro-inflammatory cytokines （IL-6 and TNF-α） increased in model group B compared with that of control and model group A （IL-6：1.86±0.21 vs 1.41 ±0.33, 1.38± 0.42, P 〈 0.01; TNF-α： 1.18±0.07 vs 0.66 ±0.08, 0.86 ±0.43, P 〈 0.01, P 〈 0.05）, whereas serum adiponectin and IL-10 decreased in model groups compared with that in the control （adiponectin： A： 21.87±4.84 and B： 21.48 ±4.60 vs 27.36 ±7.29, P 〈 0.05. IL-10： A： 1.72± 0.38 and B： 1.83 ±0.39 vs 2.26±0.24, P 〈 0.01）. Lg （TC） and the degree of liver fatty infiltration was an independent determinant of serum adiponectin level analyzed by stepwise multiple regressions, resulting in 29.4% of variances. CONCLUSION： This rabbit model produces the key features of pediatric NASH and may provide a realistic model for future studies. Adiponectin level partially reflects the severity of liver steatosis, but not the degree of liver inflammation.

Nonalcoholic steatohepatitis in Asian Indians is neither associated with iron overload nor with HFE gene mutations

AIM: The pathogenesis of occurrence of liver inflammation and fibrosis in patients with nonalcoholic steatohepatitis (NASH) is not completely understood. Other than insulin resistance, iron abnormalities have been thought to be one of the triggering factors. Therefore, our aim was to study the role of iron abnormalities and HFE gene mutations in patients with NASH. METHODS: Thirty-one patients of NASH diagnosed on the basis of clinical examination biochemistry, ultrasonography and liver biopsy (n = 14) were included in the study. Serum iron parameters (n = 23) (iron, ferritin, total iron-binding capacity and transferrin saturation), Perls' iron staining on liver biopsies (n = 14) and HFE gene mutations (C282Y and H63D) (n = 16) were studied in these patients. The association between iron staining, necroinflammatory activity and fibrosis stage on liver biopsies was also determined. RESULTS: Elevated serum iron, ferritin and transferrin saturation above 55% were observed in 4.3% of patients. On histology, 71% of the patients had negative iron staining, 21.4% had 1+ staining, 7.2% had 2+ staining and none had 3+ or 4+ staining. There was no association between the degree of iron staining and necroinflammatory activity (P=0.55) and fibrosis stage (P= 0.09) on histology. None of the patients had C282Y HFE gene mutation and four patients (25%) were found to be heterozygotes for H63D gene mutation. CONCLUSION: Our study does not favor iron overload and HFE gene mutations as major factors in the pathogenesis of NASH in Asian Indians.

Cisapride decreasing orocecal transit time in patients with nonalcoholic steatohepatitis

BACKGROUND : Altered small-intestine motility, lengthening of orocecal transit time (OCTT), and small-intestinal bacterial overgrowth (SIBO) have been detected in patients with nonalcoholic steatohepatitis (NASH). These changes might be related to the progressive course and poor prognosis of the disease. This study was undertaken to investigate the effect of 4-week treatment with cisapride on OCTT. METHODS: Ten NASH patients without diabetes were included. Ten healthy individuals served as controls. OCTT was measured by lactulose breath test (LBT). Anti- endotoxin core antibodies (EndoCAb) IgG were also examined. The effect of cisapride (10 mg TID during 4 weeks) on LBT and serum EndoCAb IgG levels in NASH patients was investigated. RESULTS: The NASH patients had more significantly prolonged OCTT (95±17 min) than the controls (59±18 min, P=0.00032). Cisapride administration decreased OCTT (from 95±17 min to 83±19 min, P=0.037), basal breathed H2 (from 9.87±1.60 ppm to 8.61±1.63 ppm, P=0.046) and EndoCAb IgG titers (from 5.24±0.68 GMU/ ml to 4.20±0.72 GMU/ml, P=0.013) in NASH patients. CONCLUSIONS: The present data suggest the existence of deranged intestinal motility and endotoxemia in NASH patients. Cisapride administration during 4 weeks possibly restore intestinal motility and ameliorate endotoxemia in NASH patients.

Resveratrol and fenofibrate ameliorate fructose-induced nonalcoholic steatohepatitis by modulation of genes expression

AIM: To evaluate the effect of resveratrol, alone and in combination with fenofibrate, on fructose-induced metabolic genes abnormalities in rats.METHODS: Giving a fructose-enriched diet (FED) to rats for 12 wk was used as a model for inducing hepatic dyslipidemia and insulin resistance. Adult male albino rats (150-200 g) were divided into a control group and a FED group which was subdivided into 4 groups, a control FED, fenofibrate (FENO) (100 mg/kg), resveratrol (RES) (70 mg/kg) and combined treatment (FENO + RES) (half the doses). All treatments were given orally from the 9th week till the end of experimental period. Body weight, oral glucose tolerance test (OGTT), liver index, glucose, insulin, insulin resistance (HOMA), serum and liver triglycerides (TGs), oxidative stress (liver MDA, GSH and SOD), serum AST, ALT, AST/ALT ratio and tumor necrosis factor-α (TNF-α) were measured. Additionally, hepatic gene expression of suppressor of cytokine signaling-3 (SOCS-3), sterol regulatory element binding protein-1c (SREBP-1c), fatty acid synthase (FAS), malonyl CoA decarboxylase (MCD), transforming growth factor-β1 (TGF-β1) and adipose tissue genes expression of leptin and adiponectin were investigated. Liver sections were taken for histopathological examination and steatosis area were determined.RESULTS: Rats fed FED showed damaged liver, impairment of glucose tolerance, insulin resistance, oxidative stress and dyslipidemia. As for gene expression, there was a change in favor of dyslipidemia and nonalcoholic steatohepatitis (NASH) development. All treatment regimens showed some benefit in reversing the described deviations. Fructose caused deterioration in hepatic gene expression of SOCS-3, SREBP-1c, FAS, MDA and TGF-β1 and in adipose tissue gene expression of leptin and adiponectin. Fructose showed also an increase in body weight, insulin resistance (OGTT, HOMA), serum and liver TGs, hepatic MDA, serum AST, AST/ALT ratio and TNF-α compared to control. All treatments improved SOCS-3, FAS, MCD, TGF-β1 and leptin genes expression while only RES and FENO + RES groups showed an improvement in SREBP-1c expression. Adiponectin gene expression was improved only by RES. A decrease in body weight, HOMA, liver TGs, AST/ALT ratio and TNF-α were observed in all treatment groups. Liver index was increased in FENO and FENO + RES groups. Serum TGs was improved only by FENO treatment. Liver MDA was improved by RES and FENO + RES treatments. FENO + RES group showed an increase in liver GSH content.CONCLUSION: When resveratrol was given with half the dose of fenofibrate it improved NASH-related fructose-induced disturbances in gene expression similar to a full dose of fenofibrate.

Th17 involvement in nonalcoholic fatty liver disease progression to non-alcoholic steatohepatitis

The nonalcoholic fatty liver disease(NAFLD) is the hepatic manifestation of the metabolic syndrome. NAFLD encompasses a wide histological spectrum ranging from benign simple steatosis to non-alcoholic steatohepatitis(NASH). Sustained inflammation in the liver is critical in this process. Hepatic macrophages, including liver resident macropaghes(Kupffer cells), monocytes infiltrating the injured liver, as well as specific lymphocytes subsets play a pivotal role in the initiation and perpetuation of the inflammatory response, with a major deleterious impact on the progression of fatty liver to fibrosis. During the last years, Th17 cells have been involved in the development of inflammation not only in liver but also in other organs, such as adipose tissue or lung. Differentiation of a na?ve T cell into a Th17 cell leads to pro-inflammatory cytokine and chemokine production with subsequent myeloid cell recruitment to the inflamed tissue. Th17 response can be mitigated by T regulatory cells that secrete anti-inflammatory cytokines. Both T cell subsets need TGF-β for their differentiation and a characteristic plasticity in their phenotype may render them new therapeutic targets. In this review, we discuss the role of the Th17 pathway in NAFLD progression to NASH and to liver fibrosis analyzing different animal models of liver injury and human studies.

Betaine and nonalcoholic steatohepatitis: Back to the future?

Nonalcoholic steatohepatitis (NASH) is an important indication for liver transplantation in many Western countries. Obesity and insulin resistance are the two most common risk factors for NASH, which can lead to recurrent NASH after liver transplantation. There is currently no approved therapy for NASH, and treatment is directed at risk factor modification and lifestyle changes. Betaine has been used for NASH, with mixed results, and may show promise in conjunction with other agents in clinical trials.

Decreased phagocytic activity of Kupffer cells in a rat nonalcoholic steatohepatitis model

AIM: To investigate Kupffer cell dynamics and phagocytic activity,using a rat nonalcoholic steatohepatitis (NASH) model. METHODS: Male F344 rats were fed either a control diet or a choline-deficient L-amino acid-defined (CDAA) diet,followed by contrast enhanced ultrasonography (CEUS) using Levovist. The uptake of latex beads by the Kupffer cells was determined by fluorescent microscopy. The status of the Kupffer cells was compared between the two groups,using the immunohistochemical staining technique. RESULTS: After 4 or more wk of the CDAA diet,CEUS examination revealed a decrease in the signal intensity,20 min after intravenous Levovist. Fluorescent microscopic examination showed that the uptake of latex beads by the Kupffer cells was reduced at week 1 and 2 in the study group,compared with the controls,with no further reduction after 3 wk. Immunohistochemical staining revealed no significant difference in the Kupffer cell counts between the control group and the CDAA group. CONCLUSION: CEUS examination using Levovist demonstrated reduced contrast effect and phagocytic activity in the liver parenchymal phase,although the Kupffer cell numbers were unchanged,indicating reduced phagocytic function of the Kupffer cells in the rat NASH model. We believe that CEUS examination using Levovist is a useful screening modality,which can detect NASH in fatty liver patients.

Proteomic analysis of liver mitochondria from rats with nonalcoholic steatohepatitis

AIM: To explore mitochondrial dysfunction in nonalcoholic steatohepatitis (NASH) by analyzing the proteome of liver mitochondria from a NASH model.

Mitochondrial DNA from hepatocytes as a ligand for TLR9: Drivers of nonalcoholic steatohepatitis?

Nonalcoholic fatty liver disease(NAFLD) is the most common liver disease worldwide, affecting approximately one third of the Western world. It consists of a wide spectrum of liver disorders, ranging from fatty liver to nonalcoholic steatohepatitis(NASH), which consists of steatosis, ballooning injury and inflammation. Despite an alarming growth in the statistics surrounding NAFLD, there are as yet no effective therapies for its treatment. Innate immune signaling has been thought to play a significant role in initiating and augmenting hepatic inflammation, contributing to the transition from nonalcoholic fatty liver to NASH. An immune response is triggered by countless signals called damage-associated molecular patterns(DAMPs) elicited by lipid-laden and damaged hepatocytes, which are recognized by pattern recognition receptors(PRRs) on hepatic immune cells to initiate inflammatory signaling. In this editorial, in addition to summarizing innate immune signaling in NAFLD and discussing potential therapies that target innate immune pathways, we have described a recent study that demonstrated that mitochondrial DNA serves as a DAMP activating a hepatic PRR, TLR9, in mice and in the plasma of NASH patients. In addition to identifying a new ligand for TLR9 during NASH progression, the study shows that blocking TLR9 reverses NASH, paving the way for the development of future NASH therapy.