Recent advances in nonalcholic fatty liver disease

Danshao Shugan Granule therapy for non-alcoholic fatty liver disease

BACKGROUND

Danshao Shugan Granules (DSSG), a traditional Chinese medicine (TCM), is given to protect the liver. The objective is to evaluate the mechanisms of the effects of DSSG on non-alcoholic fatty liver disease (NAFLD).

METHODS

260 patients with NAFLD were randomly allocated to positive control drugs rosiglitazone (n = 30) and Silibinin (n = 50) as well as DSSG (n = 130) and combined DSSG/Silibinin (n = 50) groups, from which 90 patients in the DSSG group were further subdivided into 3 groups (n = 30, each) depending on the severity of symptoms. In total 33 Sprague-Dawley rats were assigned to normal (n = 10) or 45% high-fat diet (n = 23) groups, from which 9 rats served as negative controls, 10 as model controls and 10 were treated with DSSG.

RESULTS

DSSG medications had significantly highest effects on B-ultrasonography finding improvements, and reductions of total cholesterol, triglyceride, aspartate transaminase and γ-glutamyl transpeptidase in NAFLD patients. Silibinin application only led to significantly highest alanine transaminase reductions and rosiglitazone medication to significantly highest fasting plasma glucose reductions. In a murine in vivo NAFLD model glucose (GLU), total cholesterol (TC) triacylglycerol (TG) as well as glutamic pyruvic transaminase (GPT), glutamic oxaloacetic transaminase (GOT) and gamma-glutamyl transferase (GGT) serum concentrations were all significantly reduced (P < 0.001) and the expression of nuclear factor-κB (NF‑κB) was significantly decreased in DSSG treated compared to untreated NAFLD animals (P < 0.001). In addition, the DSSG treated rats exhibited increased superoxide dismutase activity and reduced malondialdehyde values.

CONCLUSIONS

DSSG was effective for treating NAFLD patients, which could be attributed to increased activity of superoxide dismutase, a decrease of malondialdehyde as well as reduced NF‑κB activity in a NAFLD rat model.

Effect of bariatric surgery on fatty liver disease in obese patients: A prospective one year follow-up study

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD), often associated with obesity and metabolic syndrome, manifests itself as steatosis, hepatic fibrosis, cirrhosis, or even end-stage liver disease. NAFLD causes inflammation, insulin resistance and cardiovascular complications. The current study aimed to evaluate the beneficial effects of bariatric surgery on biochemical parameters of hepatic functions in obese patients by comparing them before and one-year after the surgery.

METHODS

A total of 72 morbidly obese patients underwent bariatric surgery between 2016 and 2018. The incidence of diabetes mellitus in this group was 29%, median body weight was 124.5 kg (109.0-140.0) and mean body mass index (BMI) was 44.38 ± 6.770 kg/m². The used surgical procedures included gastric bypass, sleeve gastrectomy, laparoscopic gastric plication, and single anastomosis duodeno-ileal bypass-sleeve gastrectomy. Biochemical parameters including ALT/AST ratio (AAR), NAFLD fibrosis score (NFS), hepatic fibrosis index (FIB-4) and Fatty Liver Index (FLI) were evaluated in all patients at the time of surgery and one year after the intervention.

RESULTS

Significant improvement after the intervention was observed in 64 patients. A significant reduction in body weight (P<0.0001), waist circumference (P<0.0001), and body mass index (P<0.0001) were observed. NAFLD liver fibrosis index changed significantly (P<0.0001), suggesting a trend of improvement from advanced fibrosis towards stages 0-2. The FIB-4 fibrosis index indicated significant improvement (P=0.0136). Besides, a significant decline in hepatic steatosis (P<0.0001) was observed after bariatric surgery as compared to the pre-surgery fatty liver conditions.

CONCLUSION

Among the strategies to overcome NAFLD-associated impediments, bariatric surgery can be considered effective in reducing obesity and metabolic co-morbidities.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT04569396).

Nonalcoholic fatty liver disease and type 2 diabetes: where do Diabetologists stand?

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide. The increasing prevalence of NAFLD mirrors that of obesity and type 2 diabetes over the last two decades.

MAIN

In a two-way pathophysiologic relationship, NAFLD increases the risk of developing type 2 diabetes, while the latter promotes the progression of simple fatty liver to a more advanced form called nonalcoholic steatohepatitis (NASH). NASH increases the risk of cirrhosis and hepatocellular carcinoma (HCC), which may require liver transplantation. With the absence of FDA-approved medications for NAFLD treatment, lifestyle intervention remains the only therapy. Lately, extensive research efforts have been aimed at modifying NASH fibrosis and developing noninvasive screening methods.

CONCLUSION

We highlight the pathophysiologic relationships between NAFLD and type 2 diabetes, discuss disease recognition, models of care, and current and emerging therapies for NASH treatment.

Oligosaccharides from Gracilaria lemaneiformis better attenuated high fat diet-induced metabolic syndrome by promoting the Bacteroidales proliferation

Reduction in the degree of polymerization of polysaccharides can improve its bioactivity.

Association Between Index of Nutritional Quality and Nonalcoholic Fatty Liver Disease: The Role of Vitamin D and B Group

BACKGROUND

Numerous studies have revealed that diet has been considered as an important pathogenic factor for nonalcoholic fatty liver disease (NAFLD). The Index of Nutritional Quality (INQ) is a method of quantitative and qualitative evaluation of single foods and diets, which has special significance in recognizing clinical nutritional problems.

MATERIALS AND METHODS

This study included 295 patients with NAFLD and 704 controls. The dietary intake was assessed through a valid and reliable food frequency questionnaire. INQ was calculated from the questionnaire data and was compared between the 2 groups.

RESULTS

The controls had higher INQ of vitamin D, vitamin E, thiamin, riboflavin, niacin, vitamin B12; biotin, pantothenic acid, magnesium and zinc compared to the patients with NAFLD. After controlling for several covariates, positive associations were observed between NAFLD risk and INQs of riboflavin (OR_riboflavin = 0.49, 95% confidence interval [CI]: 0.28-0.78; OR_biotin = 0.35, 95% CI: 0.18-0.76; OR_pantothenic = 0.28, 95% CI: 0.12-0.64; OR_magnesium = 0.28, 95% CI: 0.11-0.75; OR_zinc = 0.15 95% CI: 0.05-0.42).

CONCLUSIONS

Findings of the present study suggest that subjects who follow a more healthy and nutrient-rich diet, especially in terms of vitamins D, B1, B2, B12, B3 and zinc, are at a lower risk of NAFLD compared to those who consume unhealthy and nutrient-poor diet.

Low hair copper concentration is related to a high risk of nonalcoholic fatty liver disease in adults

Copper, an essential micronutrient, is required for lipid metabolism, mitochondrial function, iron metabolism, and antioxidant defense. Copper deficiency has been linked to alterations in lipid metabolism and various metabolic processes of the liver, including nonalcoholic fatty liver disease (NAFLD); however, most of these studies relied on copper measurements in the blood or tissues. In this study, we investigated the association between hair copper concentration and NAFLD in Korean adults, independent of metabolic syndrome status. Clinical and laboratory parameters, including factors of metabolic syndrome, were analyzed in 751 Korean adults divided into quintiles, according to hair copper concentration. Lower hair copper concentration was significantly correlated with higher body mass index, waist circumference, blood pressure, and lower levels of high-density lipoprotein cholesterol. Subjects with NAFLD showed significantly lower hair copper concentrations, and the risk of NAFLD was significantly higher for the lower hair copper quintile groups even after adjusting for metabolic syndrome-related factors. Overall, this study suggests that lower hair copper concentration could be associated with NAFLD, independent of metabolic syndrome factors.

The role of systemic inflammation in the pathogenesis of insulin resistance and metabolic syndrome in patients with chronic hepatitis C

The systemic inflammatory response plays a key role in the development of atherosclerosis, insulin resistance (IR) and diabetes mellitus 2-type (diabetes mellitus). IR in patients with chronic hepatitis C (CHC) is considered as a possible factor in the progression of fibrosis, a predictor of the development of DM T2 and a component of the metabolic syndrome. The use of biomarkers of non-specific inflammation can be a valuable tool for assessing the risks of IR and cardiovascular diseases in patients with chronic hepatitis C. Aim of the study. To determine the role of nonspecific inflammation in the formation of IR and metabolic syndrome in patients with chronic hepatitis C. Materials and methods. The study included 205 patients with CHC aged 18 to 69 years. Patients with CHC are randomized into two groups depending on the presence of IR: group 1 - patients with a HOMA index ≥2.77, which corresponded to IR (n=110); group 2 (n=95). The levels of serum iron, C-reactive protein (CRP), serum ferritin and adipose tissue hormones [leptin, resistin, adiponectin and tumor necrosis factor-α (TNF-α)] were additionally investigated. Results. At all stages of development of IR, nonspecific inflammation was detected (according to ferritin, CRP and serum iron), increasing with increasing HOMA index [Homeostasis Model of Assessment - Insulin Resistance (HOMA-IR)] (Matthews D., 1985), metabolic syndrome and its components. In the analysis of indicators in patients with chronic hepatitis C with a body mass index

Significant Association of Aldosterone and Liver Fat Among HIV-Infected Individuals With Metabolic Dysregulation

Objective

Fatty liver disease is increased among individuals with HIV. We sought to explore how aldosterone, a key hormone linked to insulin resistance and inflammation, relates to liver fat in the large population of individuals with HIV and metabolic abnormalities.

Methods

Forty-six individuals with HIV and increased waist circumference and dysglycemia were assessed for liver fat using proton magnetic resonance spectroscopy. Serum aldosterone level was obtained following strictly controlled posture conditions and a standardized sodium diet and was related to liver fat.

Results

Among the entire group [median (interquartile range) liver fat: 5% (3%, 12%) and homeostatic model assessment of insulin resistance: 1.74 (1.21, 2.83)], serum aldosterone significantly correlated with liver fat (r = 0.31; P = 0.049). Liver fat level was significantly higher in those with aldosterone above vs below the median [8% (3%, 20%) vs 4% (2%, 10%); P = 0.02]. In the presence of metabolic syndrome, individuals with aldosterone levels above vs below the median had markedly elevated liver fat values [14% (9%, 23%) vs 5% (3%, 12%); P = 0.005] and increased presence of fatty liver disease (FLD; 92% vs 50%; P = 0.02). Controlling for metabolic syndrome, hepatitis C virus, and alcohol use, aldosterone was a significant and independent predictor of liver fat (β estimate: 0.6038, P = 0.01; overall model r² = 0.41, P = 0.0005) and FLD (OR: 1.38, P = 0.02; overall model r² = 0.28, P = 0.002).

Conclusion

These data highlight a robust association between aldosterone and liver fat among individuals with HIV and metabolic dysregulation. Increased aldosterone may be a risk factor for liver fat accumulation among the population with HIV.

Pathophysiological characteristics of non-alcoholic steatohepatitis-like changes in cholesterol-loaded type 2 diabetic rats

Spontaneously Diabetic Torii (SDT) fatty rats, a new obese diabetic model, reportedly presented with features of non-alcoholic steatohepatitis (NASH) after 32 weeks of age. We tried to accelerate the onset of NASH in SDT fatty rats using dietary cholesterol loading and noticed changes in the blood choline level which is expected to be a NASH biomarker. Body weight and biochemical parameters were measured from 8 to 24 weeks of age. At 16, 20, 24 weeks, pathophysiological analysis of the livers were performed. Hepatic lipids, lipid peroxides, and the expression of mRNA related to triglyceride (TG) synthesis, inflammation, and fibrosis were evaluated at 24 weeks. Hepatic fibrosis was observed in SDT fatty rats fed cholesterol-enriched diets (SDT fatty-Cho) from 16 weeks. Furthermore, hepatic lipids and lipid peroxide were significantly higher in SDT fatty-Cho than SDT fatty rats fed normal diets at 24 weeks. Hepatic mRNA expression related to TG secretion decreased in SDT fatty-Cho, and the mRNA expression related to inflammation and fibrosis increased in SDT fatty-Cho at 24 weeks. Furthermore, SDT fatty-Cho presented with increased plasma choline, similar to human NASH. There were no significant changes in the effects of feeding a cholesterol-enriched diet in Sprague-Dawley rats. SDT fatty-Cho has the potential to become a valuable animal model for NASH associated with type 2 diabetes and obesity.

Deletion of Thioredoxin-interacting protein ameliorates high fat diet-induced non-alcoholic steatohepatitis through modulation of Toll-like receptor 2-NLRP3-inflammasome axis: Histological and immunohistochemical study

Endemic prevalence of obesity is associated with alarming increases in non-alcoholic steatohepatitis (NASH) with limited available therapeutics. Toll-like receptor2 (TLR2) and Nod-like receptor protein 3 (NLRP3) Inflammasome are implicated in hepatic steatosis, inflammation and fibrosis; the histological landmark stages of NASH. TXNIP, a member of α-arrestin family activates NLRP3 in response to various danger stimuli. The aim of current work was to investigate the effect of TXNIP genetic deletion on histological manifestations of high fat diet-induced steatohepatitis and activation of TLR2-NLRP3-inflammasome axis. Wild-type mice (WT) and TXNIP knock out (TKO) littermates were randomized to normal diet (WT-ND and TKO-ND) or high fat diet (HFD, 60% fat) (WT-HFD and TKO-HFD). After 8-weeks, liver samples from all groups were evaluated by histological, immunohistochemical and western blot analysis. HFD resulted in significant induction of micro and macrovesicular hepatic steatosis, that was associated with increased inflammatory immune cell infiltration in WT-HFD compared with WT-ND and TKO-ND controls, but not in TKO-HFD group. In parallel, WT-HFD group showed significant fibrosis and α-SMA expression; a marker of pro-fibrotic stellate-cell activation, in areas surrounding the central vein and portal circulation, versus all other groups. Western blot revealed increased activation of TLR2-NLRP3 inflammasome pathway and downstream IL-1β and TNFα in WT-HFD group, but not in TKO-HFD group. IL-1β expression coincided within the same areas of steatosis, inflammatory cell infiltration, collagen deposition and α-SMA expression in WT-HFD mice, that was significantly reduced in TKO-HFD mice. In conclusion, TXNIP deletion ameliorates the HFD-induced steatosis, inflammatory and fibrotic response via modulation of TLR2-NLRP3 inflammasome axis. Targeting TXNIP-TLR2-NLRP3 pathway may provide potential therapeutic modalities for NASH treatment.

Scutellarin Prevents Nonalcoholic Fatty Liver Disease (NAFLD) and Hyperlipidemia via PI3K/AKT-Dependent Activation of Nuclear Factor (Erythroid-Derived 2)-Like 2 (Nrf2) in Rats

Background

Nonalcoholic fatty liver disease (NAFLD) is a condition characterized by excessive fat accumulation in the form of triglycerides. The incidence of NAFLD and hyperlipidemia, with their associated risks of end-stage liver and cardiovascular diseases, is increasing rapidly. This study aimed to investigate the effects of scutellarin on the experimental NAFLD in high-fat diet fed and chronic stress rats, and its possible mechanism.

Material/Methods

Sprague-Dawley rats were fed with high-fat diet and subjected to chronic stress for 12 weeks, and administered orally with scutellarin for 4 weeks (n=8), and then blood and livers were harvested for analyzing. Enzyme activity assay, immunofluorescence, Western blot, and quantitative RT-PCR were performed to analyze the factors of the oxidant/antioxidant system and pathway.

Results

After the high-fat diet and chronic stress administration for 12 weeks, serum and liver lipid metabolism of treatment groups with the different doses of SCU effectively improved and the degree of oxidative damage reduced. Using Western blot assay and immunofluorescence (IF) staining assay, Nrf2, HO-1, and PI3K, and AKT proteins significantly increased after SCU treatment for 4 weeks (P<0.01). The hepatic mRNA expression of HO-1, NQO1, and Nrf2 in SCU treatment groups was upregulated significantly through quantitative RT-PCR assay (P<0.05). However, compared to the positive control group, no difference was detected in the SCU (100 or 300 mg/kg) groups (P>0.05). These results indicate that SCU protects against NAFLD in rats via attenuation of oxidative stress.

Conclusions

The antioxidant effects of SCU on NAFLD are possibly dependent on PI3K/AKT activation with subsequent Nrf2 nuclear translocation, which increases expression of HO-1 and NQO1. We therefore suggest that breviscapine may be a potentially useful therapeutic strategy for NAFLD and hyperlipidemia.

Pathophysiological analysis of the progression of hepatic lesions in STAM mice

Nonalcoholic steatohepatitis (NASH) is a current health issue since the disease often leads to hepatocellular carcinoma; however, the pathogenesis of the disease has still not been fully elucidated. In this study, we investigated the pathophysiological changes observed in hepatic lesions in STAM mice, a novel NASH model. STAM mice, high fat-diet (HFD) fed mice, and streptozotocin (STZ) treated mice were prepared, and changes over time, such as biological parameters, mRNA expression, and histopathological findings, were evaluated once animal reached 5, 7, and 10 weeks of age. STZ mice presented with hyperglycemia and an increase in oxidative stress in immunohistochemical analyses of Hexanoyl-lysine: HEL from 5 weeks, with fibrosis in the liver also being observed from 5 weeks. HFD mice presented with hyperinsulinemia from 7 weeks and the slight hepatosteatosis was observed at 5 weeks, with changes significantly increasing until 10 weeks. STAM mice at 10 weeks showed significant hepatic changes, including hepatosteatosis, hypertrophic hepatocytes, and fibrosis, indicating pathological changes associated with NASH. These results suggested that the increase in oxidative stress with hyperglycemia triggered hepatic lesions in STAM mice, and insulin resistance promoted lesion formation with hepatic lipid accumulation. STAM mice may be a useful model for elucidating the pathogenesis of NASH with diabetes.

Shugan Xiaozhi Decoction Attenuates Nonalcoholic Steatohepatitis by Enhancing PPAR and L-FABP Expressions in High-Fat-Fed Rats

This study aimed to investigate the effects of Shugan Xiaozhi decoction (SX) on nonalcoholic steatohepatitis (NASH) induced by high-fat diet in rats. The rats were randomly divided into 6 groups, namely, control, model, fenofibrate, and three different dosage of SX (10, 20, and 40 g/kg/day, p.o.). After establishing the NASH model, at 8 weeks of the experiment, treatments were administrated intragastrically to the fenofibrate and SX groups. All rats were killed after 4 weeks of treatment. Compared with the model group, alanine aminotransferase (ALT), aspartate aminotransferase (AST), free fatty acid (FFA), total cholesterol (TC), triacylglycerol (TG), and low-density lipoprotein cholesterol (LDL) serum in the serum were significantly reduced in all SX treatment groups in a dose-dependent manner. Evidence showed that SX could protect the liver by upregulating the gene and protein expressions of peroxisome proliferator-activated receptor alpha (PPARα) and liver fatty acid binding protein (L-FABP) in a dose-dependent manner. Chemical constituents of SX were further analyzed by ultraperformance liquid chromatography coupled with electrospray ionization mass spectrometry (UPLC-ESI-MS) and 30 chemicals in the ethanolic extract were tentatively identified. To conclude, our results clearly indicated that SX could protect liver functions and relieve hepatic steatosis and inflammation.

Impact of Recipient and Donor Obesity Match on the Outcomes of Liver Transplantation: All Matches Are Not Perfect

There is a paucity of literature examining recipient-donor obesity matching on liver transplantation outcomes. The United Network for Organ Sharing database was queried for first-time recipients of liver transplant whose age was ≥18 between January 2003 and September 2013. Outcomes including patient and graft survival at 30 days, 1 year, and 5 years and overall, liver retransplantation, and length of stay were compared between nonobese recipients receiving a graft from nonobese donors and obese recipient-obese donor, obese recipient-nonobese donor, and nonobese recipient-obese donor pairs. 51,556 LT recipients were identified, including 34,217 (66%) nonobese and 17,339 (34%) obese recipients. The proportions of patients receiving an allograft from an obese donor were 24% and 29%, respectively, among nonobese and obese recipients. Graft loss (HR: 1.27; 95% CI: 1.09–1.46; p = 0.002) and mortality (HR: 1.38; 95% CI: 1.16–1.65; p < 0.001) at 30 days were increased in the obese recipient-obese donor pair. However, 1-year graft (HR: 0.83; 95% CI: 0.74–0.93; p = 0.002) and patient (HR: 0.84; 95% CI: 0.74–0.95; p = 0.007) survival and overall patient (HR: 0.93; 95% CI: 0.86–1.00; p = 0.042) survival were favorable. There is evidence of recipient and donor obesity disadvantage early, but survival curves demonstrate improved long-term outcomes. It is important to consider obesity in the donor-recipient match.

Combination with Red ginseng and Polygoni Multiflori ameliorates highfructose diet induced metabolic syndrome

BACKGROUND

Metabolic syndrome such as dyslipidemia, hypertension, obesity, impaired glucose tolerance and fatty liver, can be caused by modification of diet by means of overconsumption of high fructose diet. This study was designed to investigate whether combination with Red ginseng and Polygoni Multiflori Radix (RGPM), widely used traditional herbal medicine, ameliorates on highfructose (HF) diet-induced metabolic syndrome.

METHODS

SD rats were fed the 60% HF diet with/without rosiglitazone, and RGPM 100, 300 mg/kg/day, respectively. All groups received regular diet or HF diet, respectively, for 8 weeks. The last three groups treatment of rosiglitazone and RPGM orally for a period of 6 weeks.

RESULTS

Chronic treatment with RGPM significantly decreased body weight, fat weight and adipocyte size. RGPM significantly prevented the development of the metabolic disturbances such as hypertension, hyperlipidemia and impaired glucose tolerance. RGPM also led to increase in high density lipoprotein level in the HF group. RGPM suppressed high-fructose diet induced vascular inflammation marker expression such as adhesion molecules and ET-1 in aorta as well as increasing of C-reactive protein (CRP) levels in plasma. Similarly, RGPM attenuated hepatic lipid accumulation by inhibition of monocyte chemoattractant protein-1 (MCP-1) expression.

CONCLUSION

An administration of RGPM may be a beneficial therapy for the treatment of metabolic syndrome through the improvement of hypertension, obesity, hyperlipidemia, vascular inflammation and insulin resistance.

Effect of Clematis polysaccharide on serum IL-17 and TNF-α levels and hepatic pathological changes in rats with non-alcoholic steatohepatitis

AIM: To investigate the effect of Clematis polysaccharide on serum levels of interleukin-17 (IL-17) and tumor necrosis factor alpha (TNF-α) and hepatic pathological changes in rats with non-alcoholic steatohepatitis (NASH), and to analyze the correlation between serum levels of IL-17 and TNF-α.

METHODS: A rat model of NASH was established by feeding SD rats a high-fat diet. The levels of fasting IL-17 and TNF-α were tested, and the liver fatty degeneration grade and liver inflammation grade were assessed for NASH model rats, NASH rats treated with Clematis polysaccharide, NASH rats treated with polyene phosphatidylcholine, and normal rats. The differences in fasting IL-17 and TNF-α levels and hepatic pathological changes among all groups were compared, and the correlation between serum levels of IL-17 and TNF-α was analyzed.

RESULTS: Compared with the model group, NASH rats treated with Clematis polysaccharide had milder liver fatty degeneration and liver inflammation (P < 0.05 for both) and lower serum levels of IL-17 and TNF-α (P < 0.01 for both). Compared with the polyene phosphatidylcholine group, NASH rats treated with Clematis polysaccharide had a similar liver fatty degeneration grade and liver inflammation grade, and similar serum IL-17 and TNF-α levels (P > 0.05 for all).

CONCLUSION: Clematis polysaccharide is effective in NASH rats, its therapeutic effect is equivalent to that of polyene phosphatidylcholine, and the underlying mechanism may be associated with reducing serum IL-17 and TNF-α levels, and improving hepatic pathological change.

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 mL/kg Sal B (1 mg/mL) 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 CytC and caspase-3 was determined by immunohistochemistry. The mRNA 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. CytC (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 mRNA expression of NF-κB increased (0.81 ± 0.02 vs 0.91 ± 0.03, P < 0.05), whereas the mRNA 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. CytC (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 mRNA expression of NF-κB also decreased (0.91 ± 0.03 vs 0.74 ± 0.02, P < 0.01), whereas the mRNA 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.

Female spontaneously diabetic Torii fatty rats develop nonalcoholic steatohepatitis-like hepatic lesions

AIM: To investigate the histological features of the liver in spontaneously diabetic Torii (SDT) fatty rats compared with age-matched Sprague-Dawley (SD) rats.

METHODS: Female SDT Lepr^fa (SDT fatty) rats and age-matched SD rats were fed ad libitum. Body weight and biochemical parameters, such as serum glucose, triglyceride (TG), total cholesterol (TC), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels as well as fatty acid and TG accumulation in the liver were evaluated at 8 wk of age in the non-fasting state and at 8-wk intervals from 8 to 40 wk of age. Histopathological examinations of the liver were performed using hematoxylin and eosin and Sirius Red staining as well as double staining for ED-1 and toluidine blue. The expression of genes involved in TG synthesis, inflammation, and fibrosis was examined in the liver.

RESULTS: SDT fatty rats showed significantly increased body weight compared with SD rats. Serum glucose, TG, and TC levels were significantly higher in SDT fatty rats compared with SD rats. The serum AST and ALT levels in SDT fatty rats were significantly elevated at 8 wk of age compared with the levels in SD rats. Hepatic TG content was marked in SDT fatty rats from 8 to 32 wk of age. Histopathologically, severe hepatosteatosis accompanied by inflammation was observed at 8 wk of age, and fibrosis started to occur at 32 wk of age. Furthermore, Sirius Red and ED-1 staining were increased in the liver at 32 wk of age. Hepatic gene expression related to TG synthesis, inflammation and fibrosis tended to increase in SDT fatty rats compared with SD rats, and the gene expression related to TG secretion was decreased in SDT fatty rats compared with SD rats.

CONCLUSION: Female SDT fatty rats have the potential to become an important animal model of nonalcoholic steatohepatitis with type 2 diabetes and obesity.

Microcystin-LR altered mRNA and protein expression of endoplasmic reticulum stress signaling molecules related to hepatic lipid metabolism abnormalities in mice

To explore the effects of microcystin-LR (MC-LR), a hepatotoxin, on the incidence of liver lipid metabolism abnormality, and the potential molecular mechanisms of action, healthy male Balb/c mice were intraperitoneally injected with MC-LR at doses of 0, 5, 10, and 20 μg/kg/d for 14 days. Hepatic histopathology and serum lipid parameters of mice were determined, and the changes of mRNA and protein expression of endoplasmic reticulum (ER) stress signaling molecules related to the lipid metabolism abnormalities in the livers of mice were investigated by quantitative real-time polymerase chain reaction (qPCR) and Western blotting, respectively. The results indicated that 5-20 μg/kg/d MC-LR altered serum lipid parameters and caused hepatic steatosis. MC-LR treatment at 10 or 20 μg/kg/d changed mRNA and protein expression of ER stress signaling molecules, including upregulation of mRNA and protein expression of activating transcription factor 6 (ATF6), pancreatic ER eukaryotic translation initiation factor 2α (eIF-2α) kinase (PERK), and eIF-2α. MC-LR exposure at 10 or 20 μg/kg/d also altered mRNA and protein expression of downstream factors and genes of ER stress signaling pathways, including the downregulation of sterol regulatory element binding protein 1c (SREBP-1c) and fatty acid synthase (FASn), and upregulation of acetyl-coenzyme A carboxylase α (ACACA) and glycogen synthase kinase 3β (Gsk-3β). Our results reveal that ER stress plays a significant role in hepatic lipid metabolism abnormalities in mice exposed to MC-LR.

Combined Serum Biomarkers in Non-Invasive Diagnosis of Non-Alcoholic Steatohepatitis

BACKGROUND

Non-alcoholic steatoheaptitis (NASH), the critical stage of non-alcoholic fatty liver disease (NAFLD), is of chronic progression and can develop cirrhosis even hepatocellular carcinoma (HCC). However, non-invasive biomarkers for NASH diagnosis remain poorly applied in clinical practice. Our study aims at testing the accuracy of the combination of cytokeratin-18 M30 fragment (CK-18-M30), fibroblast growth factor 21 (FGF-21), interleukin 1 receptor antagonist (IL-1Ra), pigment epithelium-derived factor (PEDF) and osteoprotegerin (OPG) in diagnosing NAFLD and NASH.

METHODS

179 patients with biopsy-proven NAFLD were enrolled as training group, 91 age- and gender-matched healthy subjects were recruited at the same time as controls. 63 other NAFLD patients were separately collected as validation group. 45 alcoholic fatty liver disease (AFLD) patients, 50 hepatitis B virus (HBV) patients, 52 hepatitis C virus (HCV) patients were also included. Serum biomarker levels were measured by enzyme-linked immunosorbent assay.

RESULTS

Serum levels of CK-18-M30, FGF-21, IL-1Ra and PEDF increased, while OPG decreased in a stepwise fashion in controls, non-NASH NAFLD patients and NASH patients (P < 0.01). The area under receiver-operating characteristics curve to diagnose NASH was 0.86 for CK-18-M30, 0.89 for FGF-21, 0.89 for IL-1Ra, 0.89 for PEDF and 0.89 for OPG. CK-18-M30 had 70% negative predictive value (NPV) and 79% positive predictive value (PPV) to diagnose NASH. A 5-step approach measuring CK-18-M30 followed by FGF21, IL-1Ra, PEDF and OPG gradually improved the NPV to 76% and PPV to 85%, which reached 80% and 76% respectively in the validation cohort.

CONCLUSION

Compared to single biomarker, stepwise combination of CK-18-M30, FGF-21, IL-1Ra, PEDF and OPG can further improve the accuracy in diagnosing NASH.

Prenatal nicotine exposure-induced intrauterine programming alteration increases the susceptibility of high-fat diet-induced non-alcoholic simple fatty liver in female adult offspring rats

“Two intrauterine programming”, involved in the intrauterine origin of high-fat diet-induced NAFL in female offspring rats, induced by prenatal nicotine exposure.

Liver injury attenuation by curcumin in a rat NASH model: an Nrf2 activation-mediated effect?

AIM

Nuclear factor-erythroid 2-related factor-2 (Nrf2) acts as a defense system in the development of nonalcoholic steatohepatitis (NASH). Curcumin is a phenolic compound with lipid regulatory, anti-oxidative, anti-inflammatory and anti-tumorigenic properties that is beneficial in defending against NASH and was recently proved to be an Nrf2 activator. The aim of this study was to evaluate whether Nrf2 activation could be involved in NASH mitigation by curcumin.

METHODS

Hepatic, metabolic, and inflammatory parameters, along with hepatic Nrf2 protein expression were explored in adult Sprague-Dawley rats developing high-fat-diet-induced NASH and submitted to curcumin gavage for 6 weeks.

RESULTS

Curcumin administration led to lower degrees of hepatic steatosis and inflammation; lower levels of serum aminotransferases, lipids, and homeostasis model assessment of insulin resistance; and lower serum and hepatic contents of tumor necrosis factor-α (TNF-α), interleukin-6, and malondialdehyde. In contrast, higher hepatic contents of glutathione, heme oxygenase-1 and superoxide dismutase were observed in rats with curcumin. Moreover, Nrf2 expression in liver cell nuclei was significantly higher in rats with curcumin.

CONCLUSIONS

Curcumin can prevent and ameliorate NASH via lipid reduction, improve insulin resistance, improve anti-inflammatory, and have antioxidant effects, possibly related to its activation of Nrf2.

Uric acid induces fat accumulation via generation of endoplasmic reticulum stress and SREBP-1c activation in hepatocytes

Non-alcoholic fatty liver disease (NAFLD) is currently one of the most common types of chronic liver injury. Elevated serum uric acid is a strong predictor of the development of fatty liver as well as metabolic syndrome. Here we demonstrate that uric acid induces triglyceride accumulation by SREBP-1c activation via induction of endoplasmic reticulum (ER) stress in hepatocytes. Uric acid-induced ER stress resulted in an increase of glucose-regulated protein (GRP78/94), splicing of the X-box-binding protein-1 (XBP-1), the phosphorylation of protein kinase RNA-like ER kinase (PERK), and eukaryotic translation initiation factor-2α (eIF-2α) in cultured hepatocytes. Uric acid promoted hepatic lipogenesis through overexpression of the lipogenic enzyme, acetyl-CoA carboxylase 1 (ACC1), fatty acid synthase (FAS), and stearoyl-CoA desaturase 1 (SCD1) via activation of SREBP-1c, which was blocked by probenecid, an organic anion transport blocker in HepG2 cells and primary hepatocytes. A blocker of ER stress, tauroursodeoxycholic acid (TUDCA), and an inhibitor of SREBP-1c, metformin, blocked hepatic fat accumulation, suggesting that uric acid promoted fat synthesis in hepatocytes via ER stress-induced activation of SREBP-1c. Uric acid-induced activation of NADPH oxidase preceded ER stress, which further induced mitochondrial ROS production in hepatocytes. These studies provide new insights into the mechanisms by which uric acid stimulates fat accumulation in the liver.

Fatty acid elongase-5 (Elovl5) regulates hepatic triglyceride catabolism in obese C57BL/6J mice

Nonalcoholic fatty liver disease is a major public health concern in the obese and type 2 diabetic populations. The high-fat lard diet induces obesity and fatty liver in C57BL/6J mice and suppresses expression of the PPAR-target gene, FA elongase 5 (Elovl5). Elovl5 plays a key role in MUFA and PUFA synthesis. Increasing hepatic Elovl5 activity in obese mice lowered hepatic TGs and endoplasmic reticulum stress markers (X-box binding protein 1 and cAMP-dependent transcription factor 6α) and increased TG catabolism and fatty acyl carnitines. Increased hepatic Elovl5 activity did not increase hepatic capacity for β-oxidation. Elovl5 effects on hepatic TG catabolism were linked to increased protein levels of adipocyte TG lipase (ATGL) and comparative gene identification 58 (CGI58). Elevated hepatic Elovl5 activity also induced the expression of some (pyruvate dehydrogenase kinase 4 and fibroblast growth factor 21), but not other cytochrome P450 4A10 (CYP4A10), PPAR-target genes. FA products of Elovl5 activity increased ATGL, but not CGI58, mRNA through PPARβ-dependent mechanisms in human HepG2 cells. Treatment of mouse AML12 hepatocytes with the PPARβ agonist (GW0742) decreased (14)C-18:2,n-6 in TGs but did not affect β-oxidation. These studies establish that Elovl5 activity regulates hepatic levels of FAs controlling PPARβ activity, ATGL expression, and TG catabolism, but not FA oxidation.

Eplerenone ameliorates the phenotypes of metabolic syndrome with NASH in liver-specific SREBP-1c Tg mice fed high-fat and high-fructose diet

Because the renin-angiotensin-aldosterone system has been implicated in the development of insulin resistance and promotion of fibrosis in some tissues, such as the vasculature, we examined the effect of eplerenone, a selective mineralocorticoid receptor (MR) antagonist, on nonalcoholic steatohepatitis (NASH) and metabolic phenotypes in a mouse model reflecting metabolic syndrome in humans. We adopted liver-specific transgenic (Tg) mice overexpressing the active form of sterol response element binding protein-1c (SREBP-1c) fed a high-fat and fructose diet (HFFD) as the animal model in the present study. When wild-type (WT) C57BL/6 and liver-specific SREBP-1c Tg mice grew while being fed HFFD for 12 wk, body weight and epididymal fat weight increased in both groups with an elevation in blood pressure and dyslipidemia. Glucose intolerance and insulin resistance were also observed. Adipose tissue hypertrophy and macrophage infiltration with crown-like structure formation were also noted in mice fed HFFD. Interestingly, the changes noted in both genotypes fed HFFD were significantly ameliorated with eplerenone. HFFD-fed Tg mice exhibited the histological features of NASH in the liver, including macrovesicular steatosis and fibrosis, whereas HFFD-fed WT mice had hepatic steatosis without apparent fibrotic changes. Eplerenone effectively ameliorated these histological abnormalities. Moreover, the direct suppressive effects of eplerenone on lipopolysaccharide-induced TNFα production in the presence and absence of aldosterone were observed in primary-cultured Kupffer cells and bone marrow-derived macrophages. These results indicated that eplerenone prevented the development of NASH and metabolic abnormalities in mice by inhibiting inflammatory responses in both Kupffer cells and macrophages.

Prenatal ethanol exposure programs an increased susceptibility of non-alcoholic fatty liver disease in female adult offspring rats

Prenatal ethanol exposure (PEE) induces dyslipidemia and hyperglycemia in fetus and adult offspring. However, whether PEE increases the susceptibility to non-alcoholic fatty liver disease (NAFLD) in offspring and its underlying mechanism remain unknown. This study aimed to demonstrate an increased susceptibility to high-fat diet (HFD)-induced NAFLD and its intrauterine programming mechanisms in female rat offspring with PEE. Rat model of intrauterine growth retardation (IUGR) was established by PEE, the female fetus and adult offspring that fed normal diet (ND) or HFD were sacrificed. The results showed that, in PEE+ND group, serum corticosterone (CORT) slightly decreased and insulin-like growth factor-1 (IGF-1) and glucose increased with partial catch-up growth; In PEE+HFD group, serum CORT decreased, while serum IGF-1, glucose and triglyceride (TG) increased, with notable catch-up growth, higher metabolic status and NAFLD formation. Enhanced liver expression of the IGF-1 pathway, gluconeogenesis, and lipid synthesis as well as reduced expression of lipid output were accompanied in PEE+HFD group. In PEE fetus, serum CORT increased while IGF-1 decreased, with low body weight, hyperglycemia, and hepatocyte ultrastructural changes. Hepatic IGF-1 expression as well as lipid output was down-regulated, while lipid synthesis significantly increased. Based on these findings, we propose a "two-programming" hypothesis for an increased susceptibility to HFD-induced NAFLD in female offspring of PEE. That is, the intrauterine programming of liver glucose and lipid metabolic function is "the first programming", and postnatal adaptive catch-up growth triggered by intrauterine programming of GC-IGF1 axis acts as "the second programming".

Circulating microRNA 122 in the methionine and choline-deficient mouse model of non-alcoholic steatohepatitis

Non-alcoholic steatohepatitis (NASH) is a progressive form of non-alcoholic fatty liver disease (NAFLD) and is a major cause of liver cirrhosis and hepatic failure. The methionine choline-deficient diet (MCD) is a frequently used hepatotoxicity animal model of NASH that induces hepatic transaminase (ALT, AST) elevations and hepatobiliary histological changes similar to those observed in human NASH. Liver-specific microRNA-122 (miR-122) has been shown as a key regulator of cholesterol and fatty acid metabolism in adult liver, and has recently been proposed as a sensitive and specific circulating biomarker of hepatic injury. The purpose of this study was to assess miR-122 serum levels in mice receiving an MCD diet for 0, 3, 7, 14, 28 and 56 days and compare the performance vs. routine clinical chemistry when benchmarked against the histopathological liver findings. MiR-122 levels were quantified in serum using RT-qPCR. Both miR-122 and ALT/AST levels were significantly elevated in serum at all timepoints. MiR-122 levels increased on average by 40-fold after 3 days of initiating the MCD diet, whereas ALT and AST changes were 4.8- and 3.3-fold, respectively. In general, miR-122 levels remained elevated across all time points, whereas the ALT/AST increases were less robust but correlated with the progressive severity of NASH as assessed by histopathology. In conclusion, serum levels of miR-122 can potentially be used as a sensitive biomarker for the early detection of hepatotoxicity and can aid in monitoring the extent of NAFLD-associated liver injury in mouse efficacy models.

The absence of obstructive sleep apnea may protect against non-alcoholic fatty liver in patients undergoing bariatric surgery

Background

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of liver disease worldwide and its progressive form, steatohepatitis, will be the leading indication for liver transplant by 2020. While risk factors for steatohepatitis have been identified, little work has been performed to identify factors protective against NAFLD development.

Aim

This study sought to identify factors predictive of normal liver histology in a bariatric cohort.

Methods

Patients undergoing weight loss surgery with liver biopsies at the time of surgery were included. Patients with other causes of chronic liver disease were excluded.

Results

One hundred fifty-nine patients were included. Forty-nine patients had normal liver histology and 110 patients had NAFLD. Several previously identified factors associated with normal liver histology were found. Black race was the strongest predictor of the absence of NAFLD with an odds ratio (OR) of 6.8, 95% confidence interval (CI) 2.4–18.9. Low HOMA-IR was also associated with normal histology (OR 1.4, 95% CI 1.03–1.9). In contrast, low HDL was associated with a decreased chance of normal histology (OR 0.38, 95% CI 0.05–0.83). Interestingly, a novel protective factor, the absence of obstructive sleep apnea (OSA) was strongly associated with normal histology (OR 5.6, 95% CI 2.0–16.1). In multivariate regression controlling for BMI, black race, absence of OSA, low HOMA-IR and low ALT independently predicted normal liver histology with an area under the ROC curve of 0.85.

Conclusions

Our study confirmed several factors associated with normal liver histology, including black race and identified a novel factor, absence of OSA. Further evaluation of these factors will allow for improved understanding of the pathogenesis of NAFLD.

Melatonin attenuates high fat diet-induced fatty liver disease in rats

AIM: To investigate melatonin’s preventive action in oxidative stress in a rat model with high fat diet-induced non-alcoholic fatty liver disease (NAFLD).

METHODS: NAFLD was induced by high fat diet (HFD) in adult, male, Wistar rats, weighing 180-230 g. After acclimatization for one week, they were randomly assigned to 6 experimental groups that comprised animals on regular diet plus 5 or 10 mg/kg melatonin, for 4 or 8 wk; animals on HFD, with or without 5 or 10 mg/kg melatonin, for 4 or 8 wk; and animals on HFD for 8 or 12 wk, with melatonin 10 mg/kg for the last 4 wk. Liver damage was assessed biochemically by the serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and histologically. Lipid peroxidation and oxidative stress were assessed by malondialdehyde and glutathione levels in liver tissue. Lipidemic indices and portal vein pressure were also measured.

RESULTS: Compared to rats not receiving melatonin, rats on 5 or 10 mg/kg of melatonin had lower mean liver weight (-5.0 g and -4.9 g) (P < 0.001) and lower liver weight to body weight ratio (-1.0%) (P < 0.001), for the two doses, respectively. All rats fed HFD without melatonin developed severe, grade III, steatosis. Rats on HFD with concurrent use of melatonin showed significantly less steatosis, with grade III steatosis observed in 1 of 29 (3.4%) rats on 10 mg/kg melatonin and in 3 of 27 (11.1%) rats on 5 mg/kg melatonin. Melatonin was ineffective in reversing established steatosis. Melatonin also had no effect on any of the common lipidemic serum markers, the levels of which did not differ significantly among the rats on HFD, irrespective of the use or not of melatonin. Liver cell necrosis was significantly less in rats on HFD receiving melatonin than in those not on melatonin, with the AST levels declining by a mean of 170 U/L (P = 0.01) and 224 U/L (P = 0.001), and the ALT levels declining by a mean of 62.9 U/L (P = 0.01) and 93.4 U/L (P < 0.001), for the 5 and 10 mg/kg melatonin dose, respectively. Melatonin mitigated liver damage due to peroxidation and oxidative stress in liver tissue as indicated by a significant decline in MDA production by 12.7 (P < 0.001) and 12.2 (P < 0.001) μmol/L /mg protein /mg tissue, and a significant increase in glutathione by 20.1 (P = 0.004) and 29.2 (P < 0.001) μmol/L /mg protein /mg tissue, for the 5 and 10 mg/kg melatonin dose, respectively.

CONCLUSION: Melatonin can attenuate oxidative stress, lessen liver damage, and improve liver histology in rats with high fat diet-induced NAFLD, when given concurrently with the diet.

Nordihydroguaiaretic acid improves metabolic dysregulation and aberrant hepatic lipid metabolism in mice by both PPARα-dependent and -independent pathways

Creosote bush-derived nordihydroguaiaretic acid (NDGA), a lipoxygenase inhibitor, possesses antioxidant properties and functions as a potent antihyperlipidemic agent in rodent models. Here, we examined the effect of chronic NDGA treatment of ob/ob mice on plasma dyslipidemia, hepatic steatosis, and changes in hepatic gene expression. Feeding ob/ob mice a chow diet supplemented with either low (0.83 g/kg diet) or high-dose (2.5 g/kg diet) NDGA for 16 wk significantly improved plasma triglyceride (TG), inflammatory chemokine levels, hyperinsulinemia, insulin sensitivity, and glucose intolerance. NDGA treatment caused a marked reduction in liver weight and TG content, while enhancing rates of fatty acid oxidation. Microarray analysis of hepatic gene expression demonstrated that NDGA treatment altered genes for lipid metabolism, with genes involved in fatty acid catabolism most significantly increased. NDGA upregulated the mRNA and nuclear protein levels of peroxisome proliferator-activated receptor α (PPARα), and the activated (phosphorylated) form of AMP-activated kinase. NDGA increased PPARα promoter activity in AML12 hepatocytes and also prevented the fatty acid suppression of PPARα expression. In contrast, PPARα siRNA abrogated the stimulatory effect of NDGA on fatty acid catabolism. Likewise, no stimulatory effect of NDGA on hepatic fatty acid oxidation was observed in the livers of PPARα-deficient mice, but the ability of NDGA to reverse fatty liver conditions was unaffected. In conclusion, the beneficial actions of NDGA on dyslipidemia and hepatic steatosis in ob/ob mice are exerted primarily through enhanced fatty acid oxidation via PPARα-dependent pathways. However, PPARα-independent pathways also contribute to NDGA's action to ameliorate hepatic steatosis.

Effect of bariatric surgery on liver fibrosis

BACKGROUND

Although bariatric surgery has been shown to improve hepatic steatosis in morbidly obese patients, the effect of weight loss on hepatic fibrosis has not been determined. Since the prognosis of patients with nonalcoholic fatty liver disease is closely related to the development of hepatic fibrosis, it is important to determine the hepatic histology of these patients after weight loss. We therefore evaluated the prevalence of hepatic fibrosis in morbidly obese patients undergoing bariatric surgery and assessed the correlation of histologic changes with weight loss.

METHODS

We retrospectively evaluated 78 morbidly obese patients who underwent gastric bypass. Liver biopsies were taken during surgery and after weight loss, and the correlations between histologic findings and hepatic fibrosis were determined.

RESULTS

Of the 78 patients, 35 (44.8%) had fibrosis at first biopsy, and 24 (30.8%) had hepatic fibrosis after weight loss, including 19 of the 35 patients (54.3%) with fibrosis at first biopsy and 5 of the 43 (11.6%) without hepatic fibrosis at first biopsy (P = 0.027).

CONCLUSIONS

Weight loss in morbidly obese patients was associated with a reduction in the prevalence of hepatic fibrosis.

Effects of supplementation with essential amino acids on intrahepatic lipid concentrations during fructose overfeeding in humans

BACKGROUND

A high dietary protein intake has been shown to blunt the deposition of intrahepatic lipids in high-fat- and high-carbohydrate-fed rodents and humans.

OBJECTIVE

The aim of this study was to evaluate the effect of essential amino acid supplementation on the increase in hepatic fat content induced by a high-fructose diet in healthy subjects.

DESIGN

Nine healthy male volunteers were studied on 3 occasions in a randomized, crossover design after 6 d of dietary intervention. Dietary conditions consisted of a weight-maintenance balanced diet (control) or the same balanced diet supplemented with 3 g fructose · kg(-1) · d(-1) and 6.77 g of a mixture of 5 essential amino acids 3 times/d (leucine, isoleucine, valine, lysine, and threonine) (HFrAA) or with 3 g fructose · kg(-1) · d(-1) and a maltodextrin placebo 3 times/d (HFr); there was a washout period of 4 to 10 wk between each condition. For each condition, the intrahepatocellular lipid (IHCL) concentration, VLDL-triglyceride concentration, and VLDL-[(13)C]palmitate production were measured after oral loading with [(13)C]fructose.

RESULTS

HFr increased the IHCL content (1.27 ± 0.31 compared with 2.74 ± 0.55 vol %; P < 0.05) and VLDL-triglyceride (0.55 ± 0.06 compared with 1.40 ± 0.15 mmol/L; P < 0.05). HFr also enhanced VLDL-[(13)C]palmitate production. HFrAA significantly decreased IHCL compared with HFr (to 2.30 ± 0.43 vol%; P < 0.05) but did not change VLDL-triglyceride concentrations or VLDL-[(13)C]palmitate production.

CONCLUSIONS

Supplementation with essential amino acids blunts the fructose-induced increase in IHCL but not hypertriglyceridemia. This is not because of inhibition of VLDL-[(13)C]palmitate production. This trial was registered at www.clinicaltrials.gov as NCT01119989.

The pathogenesis of non-alcoholic fatty liver disease is closely related to the metabolic syndrome components

Non-alcoholic fatty liver disease (NAFLD) is closely associated with all features ofthe metabolic syndrome (MS). This strongly supports the notion that NAFLD may bethe hepatic manifestation of the MS. NAFLD is currently the most common cause ofabnormal liver function tests and affects approximatively 15-25% of the generalpopulation. NAFLD covers a spectrum of liver disease, from steatosis to nonalcoholicsteatohepatitis (NASH) and cirrhosis. Insulin resistance (IR) has centraletiologic roles in the development of MS and NAFLD, usually related to obesity. MSis frequently associated with chronic inflammation, having as principal mediatorsthe adipocytokines and free fatty acids (FFA), but also CRP, TNF-a and IL-6.Chronic inflammation results in more IR and lipolysis of adipose tissue triglyceridestores, in enhanced hepatic glucose and VLDL production. The steatotic liver isthought to be vulnerable to secondary injuries including adipocytokines,mitochondrial dysfunctions, oxidative stress which lead to hepatocellularinflammation and fibrosis.

Ursodeoxycholic acid improves insulin sensitivity and hepatic steatosis by inducing the excretion of hepatic lipids in high-fat diet-fed KK-Ay mice

Type 2 diabetes mellitus is frequently accompanied by fatty liver/nonalcoholic fatty liver disease. Hence, accumulation of lipids in the liver is considered to be one of the risk factors for insulin resistance and metabolic syndrome. Ursodeoxycholic acid (UDCA) is widely used for the treatment of liver dysfunction. We investigated the therapeutic effects of UDCA on type 2 diabetes mellitus exacerbating hepatic steatosis and the underlying mechanisms of its action using KK-A(y) mice fed a high-fat diet. KK-A(y) mice were prefed a high-fat diet; and 50, 150, and 450 mg/kg of UDCA was orally administered for 2 or 3 weeks. Administration of UDCA decreased fasting hyperglycemia and hyperinsulinemia. Hyperinsulinemic-euglycemic clamp analyses showed that UDCA improved hepatic (but not peripheral) insulin resistance. Hepatic triglyceride and cholesterol contents were significantly reduced by treatment with UDCA, although the genes involved in the synthesis of fatty acids and cholesterol, including fatty acid synthase and 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase, were upregulated. Fecal levels of bile acids, neutral sterols, fatty acids, and phospholipids were significantly increased by UDCA treatment. The gene expression levels and protein phosphorylation levels of endoplasmic reticulum stress markers were not changed by UDCA treatment. These results indicate that UDCA ameliorates hyperglycemia and hyperinsulinemia by improving hepatic insulin resistance and steatosis in high-fat diet-fed KK-A(y) mice. Reduction of hepatic lipids might be due to their excretion in feces, followed by enhanced utilization of glucose for the synthesis of fatty acids and cholesterol. Ursodeoxycholic acid should be effective for the treatment of type 2 diabetes mellitus accompanying hepatic steatosis.

Therapeutic potential of green tea in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a constellation of progressive liver disorders that are closely related to obesity, diabetes, and insulin resistance and may afflict over 70 million Americans. NAFLD may occur as relatively benign, nonprogressive liver steatosis, but in many individuals it may progress in severity to nonalcoholic steatohepatitis, fibrosis, cirrhosis, and liver failure or hepatocellular carcinoma. No validated treatments currently exist for NAFLD except for weight loss, which has a poor long-term success rate. Thus, dietary strategies that prevent the development of liver steatosis or its progression to nonalcoholic steatohepatitis are critically needed. Green tea is rich in polyphenolic catechins that have hypolipidemic, thermogenic, antioxidant, and anti-inflammatory activities that may mitigate the occurrence and progression of NAFLD. This review presents the experimental evidence demonstrating the hepatoprotective properties of green tea and its catechins and the proposed mechanisms by which these targeted dietary agents protect against NAFLD.

Non-alcoholic fatty liver disease: is iron relevant?

Non-alcoholic fatty liver disease (NAFLD) is a common and ubiquitous disorder (Bedogni et al. in Hepatology 42:44-52, 2005; Bellentani et al. in Ann Intern Med 132:112-117, 2000) which in a proportion of subjects leads to non-alcoholic steatohepatitis (NASH), advanced liver disease and hepatocellular carcinoma. Although the factors responsible for progression of disease are still uncertain, there is evidence that insulin resistance (IR) is a key operative mechanism (Angulo et al. in Hepatology 30:1356-1362, 1999) and that two stages are involved. The first is the accumulation of triglycerides in hepatocytes followed by a "second hit" which promotes cellular oxidative stress. Several factors may be responsible for the induction of oxidative stress but hepatic iron has been implicated in various studies. The topic is controversial, however, with early studies showing an association between hepatic iron (with or without hemochromatosis gene mutations) and the progression to hepatic fibrosis. Subsequent studies, however, could not confirm an association between the presence of hepatic iron and any of the histological determinants of NAFLD or NASH. Recent studies have reactivated interest in this subject firstly, with the demonstration that hepatic iron loading increases liver cholesterol synthesis with increased lipid deposition in the liver increasing the cellular lipid burden and secondly, a large clinical study has concluded that hepatocellular iron deposition is associated with an increased risk of hepatic fibrosis, thus, strongly supporting the original observation made over a decade ago. An improvement in insulin sensitivity has been demonstrated following phlebotomy therapy but a suitably powered controlled clinical trial is required before this treatment can be implemented.

Galantamine alleviates inflammation and other obesity-associated complications in high-fat diet-fed mice

Obesity, a serious and growing health threat, is associated with low-grade inflammation that plays a role in mediating its adverse consequences. Previously, we have discovered a role for neural cholinergic signaling in controlling inflammation, and demonstrated that the cholinergic agent galantamine suppresses excessive proinflammatory cytokine release. The main objective of this study was to examine the efficacy of galantamine, a clinically-approved drug, in alleviating obesity-related inflammation and associated complications. After 8 wks on a high-fat diet, C57BL/6J mice were treated with either galantamine (4 mg/kg, intraperitoneally [i.p.]) or saline for 4 wks in parallel with mice on a low-fat diet and treated with saline. Galantamine treatment of obese mice significantly reduced body weight, food intake, abdominal adiposity, plasma cytokine and adipokine levels, and significantly improved blood glucose, insulin resistance and hepatic steatosis. In addition, galantamine alleviated impaired insulin sensitivity and glucose intolerance significantly. These results indicate a previously unrecognized potential of galantamine in alleviating obesity, inflammation and other obesity-related complications in mice. These findings are of interest for studying the efficacy of this clinically-approved drug in the context of human obesity and metabolic syndrome.

Chronic hepatitis and cirrhosis on MR imaging

This article focuses on the current role of magnetic resonance imaging in the detection and characterization of chronic hepatitis and cirrhosis. In particular, the characteristic MR imaging features of morphologic changes and focal manifestations of chronic liver disease are highlighted.

The etiology of hepatocellular carcinoma and consequences for treatment

Most patients with hepatocellular carcinoma (HCC) have liver cirrhosis, which develops following long periods of chronic liver disease. Cirrhosis is characterized by a decrease in hepatocyte proliferation, indicating an exhaustion of the regenerative capacity of the liver, and results in an increase in fibrous tissue and a destruction of liver cells, which may ultimately lead to the development of cancerous nodules. Half of all cases of HCC are associated with hepatitis B virus infection, with a further 25% associated with hepatitis C virus. Other risk factors for developing HCC include alcoholic liver disease, nonalcoholic steatohepatitis, intake of aflatoxin-contaminated food, diabetes, and obesity. There are multiple factors involved in the etiology of HCC, all of which have a direct impact on patient characteristics and disease course, and although a causative agent can often be identified, HCC remains an extremely complex condition associated with a poor prognosis. Additionally, the geographic variation in etiology means that information from different countries is needed in order to optimize surveillance methods and develop effective chemoprevention strategies. Unfortunately, there are still many gaps in our current understanding, and further research efforts are needed to fully elucidate the diverse mechanisms involved in the pathogenesis of HCC and offer optimal prevention strategies for those at risk.

Mitochondria as potential targets in antidiabetic therapy

A growing body of evidence suggests that mitochondrial abnormalities are involved in diabetes and associated complications. This chapter gives an overview about the effects of diabetes in mitochondrial function of several tissues including the pancreas, skeletal and cardiac muscle, liver, and brain. The realization that mitochondria are at the intersection of cells' life and death has made them a promising target for drug discovery and therapeutic interventions. Here, we also discuss literature that examined the potential protective effect of insulin, insulin-sensitizing drugs, and mitochondrial-targeted antioxidants.

A new composite model including metabolic syndrome, alanine aminotransferase and cytokeratin-18 for the diagnosis of non-alcoholic steatohepatitis in morbidly obese patients

BACKGROUND

Non-invasive approaches are useful to differentiate simple steatosis from non-alcoholic steatohepatitis (NASH) in obese and morbidly obese patients.

AIM

To develop a new scoring system to diagnose definitive NASH.

METHODS

Preoperative clinical and biological data including serum caspase 3-generated cytokeratin-18 fragments (CK18) and surgical liver biopsies were obtained from 464 morbidly obese patients who had undergone bariatric surgery. The cohort was divided into two groups: training group (n = 310) and validation group (n = 154). Definitive NASH was defined according to Kleiner's classification with a Non-alcoholic fatty liver disease Activity Score (NAS) ≥5.

RESULTS

  Alanine aminotransferase (ALT), CK18 fragments and the presence of metabolic syndrome were independent predictors for discriminating patients with NAS ≥5 in the training group. These three parameters were used to carry out a scoring system for the prediction of NAS ≥5. Whereas serum CK18 fragment alone had an area under the receiver operating characteristic (AUROC) curve = 0.74, AUROC curves of the scoring system were 0.88 and 0.83 in the training group and the validation group, respectively.

CONCLUSION

A simple and non-invasive composite model (the Nice Model) including metabolic syndrome, ALT and CK18 fragments is able to predict accurately a non-alcoholic fatty liver disease activity score ≥5 in morbidly obese subjects.

Leukocytosis, thrombosis and early mortality in cancer patients initiating chemotherapy

BACKGROUND

Leukocytosis has been associated with thrombosis and mortality in cancer patients. We explored the association of leukocytosis with venous thromboembolism (VTE) and early mortality in cancer patients initiating chemotherapy.

METHODS

Data from a prospective, multicenter observational study of treatment-related complications in 4,405 ambulatory cancer patients initiating chemotherapy was used for this analysis. The association of leukocytosis, VTE and mortality during the course of chemotherapy was evaluated in univariate and multivariate analysis.

RESULTS

Ninety-three patients (2.1%) developed VTE and 134 (3%) died over a median follow up of 75 days (range 0-384). Of 4391 patients with available baseline white blood cell (WBC) count, 561 (12.8%) had elevated pretreatment leukocyte counts, defined as WBC > 11 x 10(9) cells/L. VTE occurred in 25 of 561 patients (4.5%) with baseline leukocytosis compared to 68 of 3830 (1.8%) with WBC <or= 11 x 10(9) cells/L (P < 0.0001). Baseline leukocytosis was associated with VTE by multivariate analysis as well (HR 2.1, 95% confidence interval 1.3-3.4, p = 0.003). Forty one patients (7.3%) with leukocytosis died compared to 92 (2.4%) with WBC <or= 11 x 10(9) cells/L (P < 0.0001). Baseline leukocytosis was associated with early mortality by multivariate analysis as well (HR 2.2, 95% confidence interval 1.5-3.3, p < 0.0001). Mortality was greatest in patients with both leukocytosis and VTE. In multivariate analysis several factors were predictive of leukocytosis.

CONCLUSIONS

Elevated WBC, particularly neutrophils, is strongly associated with increased risk of VTE and mortality in cancer patients receiving systemic chemotherapy. Further studies are needed to elicit the mechanisms involved.

Changes in hepatic gene expression upon oral administration of taurine-conjugated ursodeoxycholic acid in ob/ob mice

Nonalcoholic fatty liver disease (NAFLD) is highly prevalent and associated with considerable morbidities. Unfortunately, there is no currently available drug established to treat NAFLD. It was recently reported that intraperitoneal administration of taurine-conjugated ursodeoxycholic acid (TUDCA) improved hepatic steatosis in ob/ob mice. We hereby examined the effect of oral TUDCA treatment on hepatic steatosis and associated changes in hepatic gene expression in ob/ob mice. We administered TUDCA to ob/ob mice at a dose of 500 mg/kg twice a day by gastric gavage for 3 weeks. Body weight, glucose homeostasis, endoplasmic reticulum (ER) stress, and hepatic gene expression were examined in comparison with control ob/ob mice and normal littermate C57BL/6J mice. Compared to the control ob/ob mice, TUDCA treated ob/ob mice revealed markedly reduced liver fat stained by oil red O (44.2±5.8% vs. 21.1±10.4%, P<0.05), whereas there was no difference in body weight, oral glucose tolerance, insulin sensitivity, and ER stress. Microarray analysis of hepatic gene expression demonstrated that oral TUDCA treatment mainly decreased the expression of genes involved in de novo lipogenesis among the components of lipid homeostasis. At pathway levels, oral TUDCA altered the genes regulating amino acid, carbohydrate, and drug metabolism in addition to lipid metabolism. In summary, oral TUDCA treatment decreased hepatic steatosis in ob/ob mice by cooperative regulation of multiple metabolic pathways, particularly by reducing the expression of genes known to regulate de novo lipogenesis.

Non-alcoholic steatosis/steatohepatitis – 2010

A nem alkoholos eredetű zsírmáj és a steatohepatitis a kóros májműködés leggyakoribb oka. A szerzők áttekintik a kórkép fő kóroki tényezőit, kialakulásának lehetséges hátterét, klinikumát, valamint a kórisme felállításának nehézségeit. Nagy az igény olyan, nem invazív biomarkerek (TNF-α adiponektin, lipidperoxidáció termékei, citokeratin-18, hialuronsav), pontrendszerek (Fibrotest, APRI), vizsgálatok (Fibroscan) kidolgozására, amelyek a betegség előrehaladását, a gyulladást és a fibrosist jelzik. Mind ez idáig megfelelően hatékony kezelés nem ismert. A terápia részben a kiváltó tényezők eliminálását (testsúlycsökkentés), az anyagcserezavar (diabetes mellitus, hyperlipidaemia) kezelését célozza meg, részben a májvédelmet (antioxidánsok) helyezi előtérbe. Orv. Hetil., 2010, 47, 1940–1945.

A role for low hepatic copper concentrations in nonalcoholic Fatty liver disease

OBJECTIVES

Copper has a role in antioxidant defense, lipid peroxidation, and mitochondrial function, and copper deficiency has been linked to atherogenic dyslipidemia. We aimed to investigate the potential role of copper availability in the pathogenesis of nonalcoholic fatty liver disease (NAFLD).

METHODS

Patients with NAFLD (n=124) were compared to patients with chronic hepatitis C (n=50), hemochromatosis (n=35), alcoholic liver disease (n=13), autoimmune hepatitis (n=11), and control subjects (n=27). We determined liver and serum copper concentrations with correlation to clinical, histological, and biochemical parameters in humans. The effect of dietary copper restriction on liver histology and intermediary metabolism in rats was investigated.

RESULTS

Hepatic copper concentrations in patients with NAFLD were lower than in control subjects (17.9+/-8.4 vs. 31.4+/-8.2 microg/g; P<0.001) and in patients with other liver diseases (P<0.05 for all liver diseases). In patients with NAFLD, lower liver copper was correlated with more pronounced hepatic steatosis (R=-0.248; P=0.010), fasting glucose (R=-0.245; P=0.008), and components of the metabolic syndrome (MetS; R=0.363; P<0.001). Patients with nonalcoholic steatohepatitis (NASH; n=31) had lower hepatic copper concentrations than those with simple steatosis (n=93; P=0.038). Restriction of dietary copper in rats induced hepatic steatosis and insulin resistance (IR).

CONCLUSIONS

Reduced hepatic copper concentrations are found in human NAFLD and are associated with more pronounced hepatic steatosis, NASH, and components of the MetS. The development of hepatic steatosis and IR in response to dietary copper restriction in rats suggests that copper availability may be involved in the development of NAFLD.

The role of adipose tissue and lipotoxicity in the pathogenesis of type 2 diabetes

The widespread epidemics of obesity and type 2 diabetes mellitus (T2DM) suggest that both conditions are closely linked. An increasing body of evidence has shifted our view of adipose tissue from a passive energy depot to a dynamic "endocrine organ" that tightly regulates nutritional balance by means of a complex crosstalk of adipocytes with their microenvironment. Dysfunctional adipose tissue, particularly as observed in obesity, is characterized by adipocyte hypertrophy, macrophage infiltration, impaired insulin signaling, and insulin resistance. The result is the release of a host of inflammatory adipokines and excessive amounts of free fatty acids that promote ectopic fat deposition and lipotoxicity in muscle, liver, and pancreatic beta cells. This review focuses on recent work on how glucose homeostasis is profoundly altered by distressed adipose tissue. A better understanding of this relationship offers the best chance for early intervention strategies aimed at preventing the burden of T2DM.