Amelioration of diet-induced nonalcoholic steatohepatitis in rats by Mn-salen complexes via reduction of oxidative stress

Background

Nonalcoholic steatohepatitis (NASH), a progressive stage of nonalcoholic fatty liver disease (NAFLD), is characterized by steatosis (accumulation of triacylglycerols within hepatocytes) along with inflammation and ballooning degeneration. It has been suggested that oxidative stress may play an important role in the progress of NAFLD to NASH. The aim of present study was to determine whether antioxidant supplementations using EUK-8, EUK-134 and vitamin C could improve the biochemical and histological abnormalities associated with diet-induced NASH in rats.

Methods

NASH was induced in male N-Mary rats by feeding a methionine - choline deficient (MCD) diet. The rats were fed either normal chow or MCD diet for 10 weeks. After NASH development, the MCD-fed rats were randomly divided into four groups of six: the NASH group that received MCD diet, the EUK-8 group which was fed MCD diet plus EUK-8, the EUK-134 group which was fed MCD diet plus EUK-134 and the vitamin C group which received MCD diet plus vitamin C. EUK-8, EUK-134 and vitamin C (30 mg/kg body weight/day) were administered by gavage for eight weeks.

Results

Treatment of MCD-fed rats with salens reduced the sera aminotransferases, cholesterol, low density lipoprotein contents, the extent of lipid peroxidation and protein carbonylation whereas the HDL-C cholesterol levels were significantly increased. In addition, EUK-8 and EUK-134 improved steatosis, ballooning degeneration and inflammation in liver of MCD-fed rats.

Conclusion

Antioxidant (EUK-8, EUK-134 and vitamin C) supplementation reduces NASH-induced biochemical and histological abnormalities, pointing out that antioxidant strategy could be beneficial in treatment of NASH.     

Injury-Dependent Retention of Intraportally Administered Mesenchymal Stromal Cells Following Partial Hepatectomy of Steatotic Liver Does Not Lead to Improved Liver Recovery

The aim of this study was to evaluate the effect of bone marrow-derived mesenchymal stromal cell (BM-MSC) administration on liver function following partial hepatectomy (PHx) of methionine/choline-deficient (MCD) diet induced steatotic livers in rodents. Here we identified and validated serum cholinesterase (CHE) and triglyceride (TG) levels as non-invasive markers to longitudinally monitor rat liver function. Using in vivo bioluminescence imaging, retention of BM-MSC in the liver was observed following intraportal administration, but not after intravenous administration. Therefore, BM-MSC were intraportally delivered to investigate the effect on liver recovery and/or regeneration after PHx. However, despite recovery to normal body weight, liver weight and NAS score, both serum CHE and TG levels of non-treated and cell-treated rats with PHx after MCD diet remained significantly lower as compared to those of control rats. Importantly, serum CHE levels, but not TG levels, of cell-treated rats remained significantly lower as compared to those of non-treated rats, thereby warranting that certain caution should be considered for future clinical application of IP BM-MSC administration in order to promote liver regeneration and/or function.     

Metformin Prevents and Reverses Inflammation in a Non-Diabetic Mouse Model of Nonalcoholic Steatohepatitis

Background

Optimal treatment for nonalcoholic steatohepatitis (NASH) has not yet been established, particularly for individuals without diabetes. We examined the effects of metformin, commonly used to treat patients with type 2 diabetes, on liver pathology in a non-diabetic NASH mouse model.

Methodology/Principal Findings

Eight-week-old C57BL/6 mice were fed a methionine- and choline-deficient plus high fat (MCD+HF) diet with or without 0.1% metformin for 8 weeks. Co-administration of metformin significantly decreased fasting plasma glucose levels, but did not affect glucose tolerance or peripheral insulin sensitivity. Metformin ameliorated MCD+HF diet-induced hepatic steatosis, inflammation, and fibrosis. Furthermore, metformin significantly reversed hepatic steatosis and inflammation when administered after the development of experimental NASH.

Conclusions/Significance

These histological changes were accompanied by reduced hepatic triglyceride content, suppressed hepatic stellate cell activation, and the downregulation of genes involved in fatty acid metabolism, inflammation, and fibrogenesis. Metformin prevented and reversed steatosis and inflammation of NASH in an experimental non-diabetic model without affecting peripheral insulin resistance.     

Soluble CD14 Levels Reflect Liver Inflammation in Patients with Nonalcoholic Steatohepatitis

Background & Aims

Liver inflammation is a risk factor for the progression of nonalcoholic fatty liver disease (NAFLD). However, the diagnosis of liver inflammation is very difficult and invasive liver biopsy is still the only method to reliably detect liver inflammation. We previously reported that overexpression of CD14 in Kupffer cells may trigger the progression to nonalcoholic steatohepatitis (NASH) via liver inflammation following hyper-reactivity to low-dose lipopolysaccharide. Therefore, the aim of this study was to investigate the relationship between soluble type of CD14 (sCD14) and histological features in patients with NAFLD.

Methods

Our cohort consisted of 113 patients with liver biopsy-confirmed NAFLD and 21 age-matched healthy controls. Serum sCD14 levels were measured by an enzyme-linked immunosorbent assay.

Results

Serum sCD14 levels were significantly associated with diagnosis of NASH and the area under the receiver operator characteristic curve (AUROC) to distinguish between not NASH and NASH was 0.802. Moreover, serum sCD14 levels were significantly associated with the disease activity based on NAFLD activity score and hepatic CD14 mRNA expression, which is correlated with membrane CD14 (mCD14) expression, in patients with NAFLD. In multiple regression analysis, the serum sCD14 levels were independently associated with liver inflammation. The AUROC to distinguish between mild and severe liver inflammation in patients with NAFLD was 0.752.

Conclusions

We found that serum sCD14 levels increased significantly with increasing liver inflammation grade in patients with NAFLD, reflecting increased hepatic CD14 expression. Serum sCD14 is a promising tool to predict the worsening of liver inflammation, and may offer a potential biomarker for evaluation of therapeutic effects in NAFLD.     

Comprehensive miRNA Expression Analysis in Peripheral Blood Can Diagnose Liver Disease

Background

miRNAs circulating in the blood in a cell-free form have been acknowledged for their potential as readily accessible disease markers. Presently, histological examination is the golden standard for diagnosing and grading liver disease, therefore non-invasive options are desirable. Here, we investigated if miRNA expression profile in exosome rich fractionated serum could be useful for determining the disease parameters in patients with chronic hepatitis C (CHC).

Methodology

Exosome rich fractionated RNA was extracted from the serum of 64 CHC and 24 controls with normal liver (NL). Extracted RNA was subjected to miRNA profiling by microarray and real-time qPCR analysis. The miRNA expression profiles from 4 chronic hepatitis B (CHB) and 12 non alcoholic steatohepatitis (NASH) patients were also established. The resulting miRNA expression was compared to the stage or grade of CHC determined by blood examination and histological inspection.

Principal Findings

miRNAs implicated in chronic liver disease and inflammation showed expression profiles that differed from those in NL and varied among the types and grades of liver diseases. Using the expression patterns of nine miRNAs, we classified CHC and NL with 96.59% accuracy. Additionally, we could link miRNA expression pattern with liver fibrosis stage and grade of liver inflammation in CHC. In particular, the miRNA expression pattern for early fibrotic stage differed greatly from that observed in high inflammation grades.

Conclusions

We demonstrated that miRNA expression pattern in exosome rich fractionated serum shows a high potential as a biomarker for diagnosing the grade and stage of liver diseases.     

Alcohol Consumption,One-Carbon Metabolites,Liver Cancer and Liver Disease Mortality

Background

Excess alcohol consumption adversely affects one-carbon metabolism and increases the risk of liver disease and liver cancer. Conversely, higher folate levels have been inversely associated with liver damage. The current study investigated the effects of alcohol and one-carbon metabolite intake on liver cancer incidence and liver disease mortality within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study.

Methods

Cox proportional hazards modeling was used to calculate hazard ratios and 95% confidence intervals (CIs) in a population of 27,086 Finnish males with 194 incident liver cancers and 213 liver disease deaths. In a nested case-control subset (95 liver cancers, 103 controls), logistic regression was used to calculate odds ratios and 95% CIs for serum one-carbon metabolites in relation to liver cancer risk.

Results

Daily alcohol consumption of more than 20.44 g was associated with an increased risk of both liver cancer incidence (Hazard Ratio (HR) 1.52, 95%CI 1.06–2.18) and liver disease mortality (HR 6.68, 95%CI 4.16–10.71). These risks were unaffected by one-carbon metabolite intake. Similarly, in the case-control study, none of the serum one-carbon metabolites were associated with liver cancer.

Conclusions

The current study provided no convincing evidence for a protective association of one-carbon metabolite intake or serum level on the risk of liver cancer or liver disease mortality.     

Micro-RNA profiling in human serum reveals compartment-specific roles of miR-571 and miR-652 in liver cirrhosis

Background and Aims

Micro-RNAs (miRNAs) have recently emerged as crucial modulators of molecular processes involved in chronic liver diseases. The few miRNAs with previously proposed roles in liver cirrhosis were identified in screening approaches on liver parenchyma, mostly in rodent models. Therefore, in the present study we performed a systematic screening approach in order to identify miRNAs with altered levels in the serum of patients with chronic liver disease and liver cirrhosis.

Methods

We performed a systematic, array-based miRNA expression analysis on serum samples from patients with liver cirrhosis. In functional experiments we evaluated the relationship between alterations of miRNA serum levels and their role in distinct cellular compartments involved in hepatic cirrhosis.

Results

The array analysis and the subsequent confirmation by qPCR in a larger patient cohort identified significant alterations in serum levels of miR-513-3p, miR-571 and miR-652, three previously uncharacterized miRNAs, in patients with alcoholic or hepatitis C induced liver cirrhosis. Of these, miR-571 serum levels closely correlated with disease stages, thus revealing potential as a novel biomarker for hepatic cirrhosis. Further analysis revealed that up-regulation of miR-571 in serum reflected a concordant regulation in cirrhotic liver tissue. In isolated primary human liver cells, miR-571 was up-regulated in human hepatocytes and hepatic stellate cells in response to the pro-fibrogenic cytokine TGF-β. In contrast, alterations in serum levels of miR-652 were stage-independent, reflecting a concordant down-regulation of this miRNA in circulating monocytes of patients with liver cirrhosis, which was inducible by proinflammatory stimuli like bacterial lipopolysaccharide.

Conclusion

Alterations of miR571 and miR-652 serum levels in patients with chronic liver disease reflect their putative roles in the mediation of fibrogenic and inflammatory processes in distinct cellular compartments involved in the pathogenesis of liver cirrhosis.     

Inverse Association between Hepatitis B Virus Infection and Fatty Liver Disease: A Large-Scale Study in Populations Seeking for Check-Up

Background

Although many studies have attempted to clarify the association between hepatitis B virus (HBV) infection and fatty liver disease, no prior studies have emphasized the relationship of HBV and fatty liver regarding different demographics of age and body mass index (BMI).

Aim

To investigate the correlation of HBV and fatty liver in the different demographics of age and BMI.

Methods

We enrolled consecutive subjects who had received health check-up services at the Taipei Veterans General Hospital from 2002 to 2009 and ultrasonography was used to diagnose fatty liver according to the practice guidelines of the American Gastroenterological Association.

Results

Among the 33,439 subjects enrolled in this study, fatty liver was diagnosed in 43.9% of the population and 38.9% of patients with chronic HBV infection. Multivariate analysis showed that BMI, age, waist circumference, systolic blood pressure, fasting glucose, cholesterol, alanine aminotransferase (ALT) levels, and platelet counts were positively associated, while hepatitis B surface antigen (HBsAg) positivity was inversely associated with fatty liver, especially for subjects with BMI>22.4 kg/m² and age>50 years. On the contrary, HBV infection was positively correlated with the presence of elevated serum ALT levels in subjects with fatty liver disease regardless of their age and BMI.

Conclusions

Metabolic factors are important determinants for the prevalence of fatty liver. Patients with HBV infection were inversely associated with fatty liver disease than the general population, especially in older and obese patients. Furthermore, metabolic factors and HBV infection were associated with elevated serum ALT levels in fatty liver disease.     

Lactobacillus rhamnosus GG Protects against Non-Alcoholic Fatty Liver Disease in Mice

Objective

Experimental evidence revealed that obesity-associated non-alcoholic fatty liver disease (NAFLD) is linked to changes in intestinal permeability and translocation of bacterial products to the liver. Hitherto, no reliable therapy is available except for weight reduction. Within this study, we examined the possible effect of the probiotic bacterial strain Lactobacillus rhamnosus GG (LGG) as protective agent against experimental NAFLD in a mouse model.

Methods

Experimental NAFLD was induced by a high-fructose diet over eight weeks in C57BL/J6 mice. Fructose was administered via the drinking water containing 30% fructose with or without LGG at a concentration resulting in approximately 5×10⁷ colony forming units/g body weight. Mice were examined for changes in small intestinal microbiota, gut barrier function, lipopolysaccharide (LPS) concentrations in the portal vein, liver inflammation and fat accumulation in the liver.

Results

LGG increased beneficial bacteria in the distal small intestine. Moreover, LGG reduced duodenal IκB protein levels and restored the duodenal tight junction protein concentration. Portal LPS (P≤0.05) was reduced and tended to attenuate TNF-α, IL-8R and IL-1β mRNA expression in the liver feeding a high-fructose diet supplemented with LGG. Furthermore liver fat accumulation and portal alanine-aminotransferase concentrations (P≤0.05) were attenuated in mice fed the high-fructose diet and LGG.

Conclusions

We show for the first time that LGG protects mice from NAFLD induced by a high-fructose diet. The underlying mechanisms of protection likely involve an increase of beneficial bacteria, restoration of gut barrier function and subsequent attenuation of liver inflammation and steatosis.     

Dietary Supplementation of Blueberry Juice Enhances Hepatic Expression of Metallothionein and Attenuates Liver Fibrosis in Rats

Aim

To investigate the effect of blueberry juice intake on rat liver fibrosis and its influence on hepatic antioxidant defense.

Methods

Rabbiteye blueberry was used to prepare fresh juice to feed rats by daily gastric gavage. Dan-shao-hua-xian capsule (DSHX) was used as a positive control for liver fibrosis protection. Liver fibrosis was induced in male Sprague-Dawley rats by subcutaneous injection of CCl₄ and feeding a high-lipid/low-protein diet for 8 weeks. Hepatic fibrosis was evaluated by Masson staining. The expression of α-smooth muscle actin (α-SMA) and collagen III (Col III) were determined by immunohistochemical techniques. The activities of superoxide dismutase (SOD) and malondialdehyde (MDA) in liver homogenates were determined. Metallothionein (MT) expression was detected by real-time RT-PCR and immunohistochemical techniques.

Results

Blueberry juice consumption significantly attenuates CCl₄-induced rat hepatic fibrosis, which was associated with elevated expression of metallothionein (MT), increased SOD activity, reduced oxidative stress, and decreased levels of α-SMA and Col III in the liver.

Conclusion

Our study suggests that dietary supplementation of blueberry juice can augment antioxidative capability of the liver presumably via stimulating MT expression and SOD activity, which in turn promotes HSC inactivation and thus decreases extracellular matrix collagen accumulation in the liver, and thereby alleviating hepatic fibrosis.     

Amelioration of Liver Injury by Continuously Targeted Intervention against TNFRp55 in Rats with Acute-on-Chronic Liver Failure

Background

Acute-on-chronic liver failure (ACLF) is an acute deterioration of established liver disease. Blocking the TNF (tumor necrosis factor)/TNFR (tumor necrosis factor receptor) 1 pathway may reduce hepatocyte apoptosis/necrosis, and subsequently decrease mortality during development of ACLF. We demonstrated that a long-acting TNF antagonist (soluble TNF receptor: IgG Fc [sTNFR:IgG-Fc]) prevented/reduced development of acute liver failure by blocking the TNF/TNFR1 (TNFRp55) pathway. However, it is still unclear if sTNFR:IgG-Fc can inhibit hepatocyte damage during development of ACLF.

Methodology

Chronic liver disease (liver fibrosis/cirrhosis) was induced in Wistar rats by repeatedly challenging with human serum albumin (HSA), and confirmed by histopathology. ACLF was induced with D-galactosamine (D-GalN)/lipopolysaccharide (LPS) i.p. in the rats with chronic liver disease. Serum and liver were collected for biochemical, pathological and molecular biological examinations.

Principal Findings

Reduced mortality was observed in sTNFR:IgG-Fc treated ACLF rats, consistent with reduced interleukin (IL)-6 levels in serum and liver, as well as reduced hepatic caspase-3 activity, compared to that of mock treated group. Reduced hepatic damage was confirmed with histopathology in the sTNFR:IgG-Fc treated group, which is consistent with reduced Bcl-2 and Bax, at mRNA and protein levels, but increased hepatocyte proliferation (PCNA). This is also supported by the findings that caspase-3 production was up-regulated significantly in ACLF group compared to the mock treated group. Moreover, up-regulated caspase-3 was inhibited following sTNFR:IgG-Fc treatment. Finally, there was up-regulation of hepatic IL-22R in sTNFR:IgG-Fc treated ACLF rats.

Conclusions

sTNFR:IgG-Fc improved survival rate during development of ACLF via ameliorating liver injury with a potential therapeutic value.     

Near-Term Anti-CD25 Monoclonal Antibody Administration Protects Murine Liver from Ischemia-Reperfusion Injury Due to Reduced Numbers of CD4+ T Cells

Background

CD4⁺ T cell is acknowledged as a key factor in the initiation phase of liver ischemia reperfusion injury. The purpose of current study is to demonstrate the effect of antecedent near-term anti-CD25 monoclonal antibody treatment on IR-induced liver injury by modulation of CD4⁺ T cells.

Methods

70% liver warm IR was induced in male C57BL/6 mice after anti-CD25 mAb or non-specific IgG administration. Liver function, histological damage, in vitro Proliferation, FACS, cytokine production, and immunofluorescence were assessed to evaluate the impact of antecedent near-term PC61 treatment on IR-induced liver injury.

Results

After 70% liver ischemia, mice preconditioned with PC61 displayed significantly preserved liver function as characterized by less histological damage and reduced serum enzymes level. Mechanistic studies revealed that the protection effect of anti-CD25 mAb was associated with ameliorated intrahepatic inflammatory milieu and reduced CD4⁺ T lymphocytes as manifested by the decrease of proinflammatory cytokine production (less expression of TNF-α, IFN-γ, IL-2, and IL-6) and the lower CD4/CD8 proportion.

Conclusions

Our results provide first line of evidence indicating that near-term treatment with anti-CD25 monoclonal antibody might provide protection for livers against IR-induced injury by reducing CD4⁺ T cells, but not influencing functional Treg population. Therefore, our results demonstrate a potential function of anti-CD25 monoclonal antibody which was neglected in the past, and may be helpful in various clinical conditions, particularly in liver and kidney transplantations.     

The Predictive Value of Golgi Protein 73 in Differentiating Benign from Malignant Liver Tumors

Introduction

In the work up of primary solid liver lesions it is essential to differentiate correctly between benign and malignant tumors, such as hepatocellular adenoma (HCA) and hepatocellular carcinoma (HCC) respectively. A promising new marker to detect HCC is Golgi Protein 73 (GP73). Studies comparing patients with HCC and cirrhosis with normal controls suggested that GP73 is specific for patients with HCC; however, patients with other liver tumors were not included. We therefore studied the predictive value of GP73 in differentiating between solid benign and malignant liver tumors.

Materials and Methods

This study included 264 patients: 88 patients with HCC, 88 with hepatocellular adenoma (HCA), and 88 with focal nodal hyperplasia (FNH). A blood sample was collected from each patient to measure GP73 levels using a quantitative ELISA assay and differences in outcome between subgroups were compared. The receiver operating characteristic (ROC) curve, sensitivity and specificity of GP73 were calculated and compared to alpha-fetoprotein (AFP) levels.

Results

When comparing malignant and benign liver tumors the area under ROC was 0.701 and 0.912 for GP73 and AFP respectively. Test characteristics revealed a sensitivity of 60% for GP73 and 65% for AFP; in addition the specificity was 77% for GP73 and 96% for AFP.

Conclusion

Although the literature suggests that GP73 is a valuable serum marker in patients with HCC, the serum concentration may also be increased in patients with solid benign liver tumors. Therefore, a GP73 assay is less suitable for discriminating between primary malignant and benign tumors of the liver.     

The Roles of Albumin Levels in Head and Neck Cancer Patients with Liver Cirrhosis Undergoing Tumor Ablation and Microsurgical Free Tissue Transfer

Objective

To evaluate the changes of serum albumin levels during the peri-operative period, and correlate these changes to surgical outcomes, postoperative morbidity and mortality in head and neck cancer patients with cirrhosis.

Methods

57 patients with liver cirrhosis out of 3,022 patients who underwent immediate free flap reconstruction after surgical ablation of head and neck cancer performed over a 9-year period were included in the study. Two sets of groups were arranged based on the preoperative albumin (>3.5 g/dL vs. ≤ 3.5 g/dL) and POD1 albumin (>2.7 g/dL vs. ≤ 2.7 g/dL) levels and were compared with respect to patient-related variables, surgical outcomes, medical and surgical complications, and mortalities.

Results

All patients had significant decreases in albumin levels postoperatively. Hypoalbuminemia, both preoperative and postoperative, was associated with the model for end-stage liver disease (MELD) score, the amount of blood loss, the duration of ICU stay and hospital stay, and postoperative medical and surgical complications. In particular, preoperative hypoalbuminemia (serum albumin ≤ 3.5 g/dL) was associated strongly with medical complications and mortality, while postoperative hypoalbuminemia (serum albumin ≤ 2.7 g/dL) with surgical complications.

Conclusion

Our study demonstrated the prognostic values of albumin levels in head and neck cancer patient with liver cirrhosis. The perioperative albumin levels can be utilized for risk stratification to potentially improve surgical and postoperative management of these challenging patients.     

Total and high molecular weight adiponectin and hepatocellular carcinoma with HCV infection

Background

Adiponectin is shown to be inversely associated with development and progression of various cancers. We evaluated whether adiponectin level was associated with the prevalence and histological grade of hepatocellular carcinoma (HCC), and liver fibrosis in patients with hepatitis C virus (HCV) infection.

Methods

A case-control study was conducted on 97 HCC patients (cases) and 97 patients (controls) matched for sex, Child-Pugh grade and platelet count in patients with HCV infection. The serum total and high molecular weight (HMW) adiponectin levels were measured by enzyme-linked immunosorbent assays and examined in their association with the prevalence of HCC. In addition, the relationship between these adiponectin levels and body mass index (BMI), progression of liver fibrosis, and histological grade of HCC was also evaluated. Liver fibrosis was assessed using the aspartate aminotransferase to platelet ratio index (APRI).

Results

There were no significant differences in the serum total and HMW adiponectin levels between cases and controls. Moreover, there were no inverse associations between serum total and HMW adiponectin levels and BMI in both cases and controls. On the other hand, serum total and HMW adiponectin levels are positively correlated with APRI in both cases (r = 0.491, P<0.001 and r = 0.485, P<0.001, respectively) and controls (r = 0.482, P<0.001 and r = 0.476, P<0.001, respectively). Interestingly, lower serum total (OR 11.76, 95% CI: 2.97–46.66 [P<0.001]) and HMW (OR 10.24, CI: 2.80–37.40 [P<0.001] adiponectin levels were independent risk factors of worse histological grade of HCC.

Conclusions

Our results suggested that serum total and HMW adiponectin levels were predictors of liver fibrosis, but not prevalence of HCC in patients with HCV infection. Moreover, low these adiponectin levels were significantly associated with worse histological grades.     

MicroRNA-155 Deficiency Attenuates Liver Steatosis and Fibrosis without Reducing Inflammation in a Mouse Model of Steatohepatitis

Background & Aim

MicroRNAs (miRs) regulate hepatic steatosis, inflammation and fibrosis. Fibrosis is the consequence of chronic tissue damage and inflammation. We hypothesized that deficiency of miR-155, a master regulator of inflammation, attenuates steatohepatitis and fibrosis.

Methods

Wild type (WT) and miR-155-deficient (KO) mice were fed methionine-choline-deficient (MCD) or -supplemented (MCS) control diet for 5 weeks. Liver injury, inflammation, steatosis and fibrosis were assessed.

Results

MCD diet resulted in steatohepatitis and increased miR-155 expression in total liver, hepatocytes and Kupffer cells. Steatosis and expression of genes involved in fatty acid metabolism were attenuated in miR-155 KO mice after MCD feeding. In contrast, miR-155 deficiency failed to attenuate inflammatory cell infiltration, nuclear factor κ beta (NF-κB) activation and enhanced the expression of the pro-inflammatory cytokines tumor necrosis factor alpha (TNFα) and monocyte chemoattractant protein-1 (MCP1) in MCD diet-fed mice. We found a significant attenuation of apoptosis (cleaved caspase-3) and reduction in collagen and α smooth muscle actin (αSMA) levels in miR-155 KO mice compared to WTs on MCD diet. In addition, we found attenuation of platelet derived growth factor (PDGF), a pro-fibrotic cytokine; SMAD family member 3 (Smad3), a protein involved in transforming growth factor-β (TGFβ) signal transduction and vimentin, a mesenchymal marker and indirect indicator of epithelial-to-mesenchymal transition (EMT) in miR-155 KO mice. Nuclear binding of CCAAT enhancer binding protein β (C/EBPβ) a miR-155 target involved in EMT was significantly increased in miR-155 KO compared to WT mice.

Conclusions

Our novel data demonstrate that miR-155 deficiency can reduce steatosis and fibrosis without decreasing inflammation in steatohepatitis.