Non-invasive methods for iron overload evaluation in dysmetabolic patients.

INTRODUCTION: Although hyperferritinemia may reflect the inflammatory status of patients with non-alcoholic fatty liver disease (NAFLD), approximately 33% of hyperferritinemia cases reflect real hepatic iron overload. AIM: To evaluate a non-invasive method for assessing mild iron overload in patients with NAFLD using 3T magnetic resonance imaging (MRI) relaxometry, serum hepcidin, and the expression of ferritin subunits. METHODS: This cross-sectional study assessed patients with biopsy-proven NAFLD. MRI relaxometry was performed using a 3T scanner in all patients, and the results were compared with iron content determined by liver biopsy. Ferritin, hepcidin, and ferritin subunits were assessed and classified according to ferritin levels and to siderosis identified by liver biopsy. RESULTS: A total of 67 patients with NAFLD were included in the study. MRI revealed mild iron overload in all patients (sensitivity, 73.5%; specificity, 70%). For mild (grade 1) siderosis, the transverse relaxation rate (R2*) threshold was 58.9 s-1 and the mean value was 72.5 s-1 (SD, 33.9), while for grades 2/3 it was 88.2 s-1 (SD, 31.9) (p < 0.001). The hepcidin threshold for siderosis was > 30.2 ng/mL (sensitivity, 87%; specificity, 82%). Ferritin H and ferritin L subunits were expressed similarly in patients with NAFLD, regardless of siderosis. There were no significant differences in laboratory test results between the groups, including glucose parameters and liver function tests. CONCLUSIONS: MRI relaxometry and serum hepcidin accurately assessed mild iron overload in patients with dysmetabolic iron overload syndrome.

Latin American Association for the study of the liver (ALEH) practice guidance for the diagnosis and treatment of non-alcoholic fatty liver disease.

Non-alcoholic fatty liver disease (NAFLD) currently represents an epidemic worldwide. NAFLD is the most frequently diagnosed chronic liver disease, affecting 20-30% of the general population. Furthermore, its prevalence is predicted to increase exponentially in the next decades, concomitantly with the global epidemic of obesity, type 2 diabetes mellitus (T2DM), and sedentary lifestyle. NAFLD is a clinical syndrome that encompasses a wide spectrum of associated diseases and hepatic complications such as hepatocellular carcinoma (HCC). Moreover, this disease is believed to become the main indication for liver transplantation in the near future. Since NAFLD management represents a growing challenge for primary care physicians, the Asociación Latinoamericana para el Estudio del Hígado (ALEH) has decided to organize this Practice Guidance for the Diagnosis and Treatment of Non-Alcoholic Fatty Liver Disease, written by Latin-American specialists in different clinical areas, and destined to general practitioners, internal medicine specialists, endocrinologists, diabetologists, gastroenterologists, and hepatologists. The main purpose of this document is to improve patient care and awareness of NAFLD. The information provided in this guidance may also be useful in assisting stakeholders in the decision-making process related to NAFLD. Since new evidence is constantly emerging on different aspects of the disease, updates to this guideline will be required in future.

Hepatitis C virus eradication improves immediate and delayed episodic memory in patients treated with interferon and ribavirin.

BACKGROUND: Chronic hepatitis C virus (HCV) infection is associated with impairment of cognitive function and mood disorders. Our aim was to evaluate the impact of sustained virological response (SVR) on cognitive function and mood disorders. METHOD: A prospective exploratory one arm study was conducted. Adult clinically compensated HVC patients were consecutively recruited before treatment with interferon and ribavirin for 24 to 48 weeks, according to HCV genotype. Clinical, neurocognitive and mood assessments using the PRIME-MD and BDI instruments were performed at baseline, right after half of the expected treatment has been reached and 6 months after the end of antiviral treatment. Exclusion criteria were the use of illicit psychotropic substances, mental confusion, hepatic encephalopathy, hepatocellular carcinoma, severe anemia, untreated hypothyroidism, Addison syndrome and major depression before treatment. RESULTS: Thirty six patients were enrolled and 21 completed HCV treatment (n = 16 with SVR and n = 5 without). Regardless of the viral clearance at the end of treatment, there was a significant improvement in the immediate verbal episodic memory (p = 0.010), delayed verbal episodic memory (p = 0.007), selective attention (p < 0.001) and phonemic fluency (p = 0.043). Patients with SVR displayed significant improvement in immediate (p = 0.045) and delayed verbal episodic memory (p = 0.040) compared to baseline. The baseline frequency of depression was 9.5%, which rose to 52.4% during treatment, and returned to 9.5% 6 months after the end of treatment, without significant difference between patients with and without SVR. Depressive symptoms were observed in 19.1% before treatment, 62% during (p = 0.016) and 28.6% 6 months after the end of treatment (p = 0.719). CONCLUSIONS: Eradication of HCV infection improved cognitive performance but did not affect the frequency of depressive symptoms at least in the short range.

Experimental models of liver fibrosis.

Hepatic fibrosis is a wound healing response to insults and as such affects the entire world population. In industrialized countries, the main causes of liver fibrosis include alcohol abuse, chronic hepatitis virus infection and non-alcoholic steatohepatitis. A central event in liver fibrosis is the activation of hepatic stellate cells, which is triggered by a plethora of signaling pathways. Liver fibrosis can progress into more severe stages, known as cirrhosis, when liver acini are substituted by nodules, and further to hepatocellular carcinoma. Considerable efforts are currently devoted to liver fibrosis research, not only with the goal of further elucidating the molecular mechanisms that drive this disease, but equally in view of establishing effective diagnostic and therapeutic strategies. The present paper provides a state-of-the-art overview of in vivo and in vitro models used in the field of experimental liver fibrosis research.

Plasmatic higher levels of homocysteine in non-alcoholic fatty liver disease (NAFLD).

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease, which includes a spectrum of hepatic pathology such as simple steatosis, steatohepatitis, fibrosis and cirrhosis. The increased serum levels of homocysteine (Hcy) may be associated with hepatic fat accumulation. Genetic mutations in the folate route may only mildly impair Hcy metabolism. The aim of this study was to investigate the relation between liver steatosis with plasma homocysteine level and MTHFR C677T and A1298C polymorphisms in Brazilian patients with NAFLD. METHODS: Thirty-five patients diagnosed with NAFLD by liver biopsy and forty-five healthy controls neither age nor sex matched were genotyped for C677T and A1298C MTHFR polymorphisms using PCR-RFLP and PCR-ASA, respectively, and Hcy was determined by HPLC. All patients were negative for markers of Wilson's, hemochromatosis and autoimmune diseases. Their daily alcohol intake was less than 100 g/week. A set of metabolic and serum lipid markers were also measured at the time of liver biopsies. RESULTS: The plasma Hcy level was higher in NAFLD patients compared to the control group (p = 0.0341). No statistical difference for genotypes 677C/T (p = 0.110) and 1298A/C (p = 0.343) in patients with NAFLD and control subjects was observed. The genotypes distribution was in Hardy-Weinberg equilibrium (677C/T p = 0.694 and 1298 A/C p = 0.188). The group of patients and controls showed a statistically significant difference (p < 0.001) for BMI and HOMA_IR, similarly to HDL cholesterol levels (p < 0,006), AST, ALT, γGT, AP and triglycerides levels (p < 0.001). A negative correlation was observed between levels of vitamin B12 and Hcy concentration (p = 0.005). CONCLUSION: Our results indicate that plasma Hcy was higher in NAFLD than controls. The MTHFR C677T and A1298C polymorphisms did not differ significantly between groups, despite the 677TT homozygous frequency was higher in patients (17.14%) than in controls (677TT = 4.44%) (p > 0.05). The suggested genetic susceptibility to the MTHFR C677T and A1298C should be confirmed in large population based studies.

Impact of Endoscopic Sleeve Gastroplasty in Non-alcoholic Fatty Liver Disease: a Systematic Review and Meta-analysis.

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of liver disease worldwide. Endoscopic sleeve gastroplasty (ESG) has proven to be feasible, safe, and effective in the management of obesity. We performed the first systematic review and meta-analysis evaluating NAFLD and other metabolic parameters 12 months post-ESG. Four observational studies with a total of 175 patients were included. The results showed a significant (p < 0.05) reduction of 4.85 in hepatic steatosis index (95% CI - 6.02, - 3.67), 0.5 in NAFLD fibrosis score (95% CI - 0.80, - 0.19), 6.32 U/l in ALT (95% CI - 9.52, - 3.11), 17.28% in TWL (95% CI - 18.24, - 16.31), 6.31 kg/m2 in BMI (95% CI - 8.11, - 4.52), 47.97% in EWL (95% CI - 49.10, - 46.84), and 0.51% in HbA1c (95% CI - 0.90, - 0.12). ESG improves liver parameters, provides weight loss, and reduces HbA1c levels in patients suffering from NAFLD.

Effects of intragastric balloon placement in metabolic dysfunction-associated fatty liver disease: A systematic review and meta-analysis.

BACKGROUND: Metabolic dysfunction-associated fatty liver disease corresponds to a clinical entity that affects liver function triggered by the accumulation of fat in the liver and is linked with metabolic dysregulation. AIM: To evaluate the effects of the intragastric balloon (IGB) in patients with metabolic dysfunction-associated fatty liver disease through the assessment of liver enzymes, imaging and several metabolic markers. METHODS: A comprehensive search was done of multiple electronic databases (MEDLINE, EMBASE, LILACS, Cochrane and Google Scholar) and grey literature from their inception until February 2021. Inclusion criteria involved patients with a body mass index > 25 kg/m2 with evidence or previous diagnosis of hepatic steatosis. Outcomes analyzed before and after 6 mo of IGB removal were alanine aminotransferase (IU/L), gamma-glutamyltransferase (IU/L), glycated hemoglobin (%), triglycerides (mg/dL), systolic blood pressure (mmHg), homeostatic model assessment, abdominal circumference (cm), body mass index (kg/m2) and liver volume (cm3). RESULTS: Ten retrospective cohort studies evaluating a total of 508 patients were included. After 6 mo of IGB placement, this significantly reduced alanine aminotransferase [mean difference (MD): 10.2, 95% confidence interval (CI): 8.12-12.3], gamma-glutamyltransferase (MD: 9.41, 95%CI: 6.94-11.88), glycated hemoglobin (MD: 0.17%, 95%CI: 0.03-0.31), triglycerides (MD: 38.58, 95%CI: 26.65-50.51), systolic pressure (MD: 7.27, 95%CI: 4.79-9.76), homeostatic model assessment (MD: 2.23%, 95%CI: 1.41-3.04), abdominal circumference (MD: 12.12, 95%CI: 9.82-14.41) and body mass index (MD: 5.07, 95%CI: 4.21-5.94). CONCLUSION: IGB placement showed significant efficacy in improving alanine aminotransferase and gamma-glutamyltransferase levels in patients with metabolic dysfunction-associated fatty liver disease as well as improving metabolic markers related to disease progression.

Ultrasound elastography in patients with fatty liver disease.

Hepatic steatosis, or fatty liver disease, occurs due to the accumulation of lipids in hepatocytes. When it becomes chronic, lobular inflammation develops and the disease can evolve to hepatic fibrosis, liver cirrhosis, or hepatocellular carcinoma. Early diagnosis is desirable because patients diagnosed in the early stage of the disease respond better to treatment. In the early stages of fatty liver disease, the physical examination is often unremarkable. Fatty liver disease and hepatic fibrosis can be diagnosed and monitored through laboratory tests, imaging, and biopsy. Among the imaging methods, ultrasound stands out as an effective means of diagnosing and following patients with liver disease. Ultrasound used in conjunction with elastography (ultrasound elastography) has recently shown great utility in the follow-up of such patients. Ultrasound elastography studies the degree of deformation (stiffness) of an organ or lesion, so that when there is hardening, fibrosis, or cirrhosis of the liver, those alterations are well demonstrated. In this review article, we discuss the application of the different types of ultrasound elastography for liver studies: transient elastography, point shear wave elastography, and two-dimensional shear wave elastography. Although magnetic resonance elastography may also be used in the analysis of liver fibrosis, it will not be addressed in this article.

Combination of N-acetylcysteine and metformin improves histological steatosis and fibrosis in patients with non-alcoholic steatohepatitis.

AIM: There is no proven medical therapy for the treatment of non-alcoholic steatohepatitis (NASH). Oxidative stress and insulin resistance are the mechanisms that seem to be mostly involved in its pathogenesis. The aim of our study was to evaluate the efficacy of N-acetylcysteine (NAC) in combination with metformin (MTF) in improving the aminotransferases and histological parameters (steatosis, inflammation, hepatocellular ballooning, and fibrosis) after 12 months of treatment. METHODS: Twenty consecutive patients (mean age 53 +/- 2 years [36-68] and body mass index [BMI] 29 [25-35]) with biopsy-proven NASH were enrolled in the study. NAC (1.2 g/day) and MTF (850-1000 mg/day) were given orally for 12 months. All patients underwent evaluation of serum aminotransferases, fasting lipid profile and serum glucose, anthropometric parameters, and nutritional status at 0 and 12 months. A low calorie diet was prescribed for all patients. RESULTS: Serum alanine aminotransferase, high-density lipoprotein, insulin, and glucose concentrations and thehomeostasis model assessment-insulin resistance (HOMA-IR) index were reduced significantly at the end of study (P < 0.05). The BMI declined, but without statistical significance. Aspartate aminotransferase, gamma-glutamyl transferase, alkaline phosphatase, cholesterol, and triglycerides levels were not altered with the treatment. Liver steatosis and fibrosis decreased (P < 0.05), but no improvement was noted in lobular inflammation or hepatocellular ballooning. The NASH activity score was significantly improved after treatment. CONCLUSION: Based on the biochemical and histological evidence in this pilot study, NAC in combination with MTF appears to ameliorate several aspects of NASH, including fibrosis. Further studies of this form of combination therapy are warranted to assess its potential efficacy.

Follow-up of Roux-en-Y gastric bypass patients at 5 or more years postoperatively.

BACKGROUND: Short-term results (24 to 36 months) after Roux-en-Y gastric bypass (RYGBP) have been extensively described. Little is reported on the patients operated > or = 5 years ago. We analyzed the results of weight loss, resolution of co-morbidities and nutritional complications of patients submitted to the silicone ring RYGBP, at least 5 years before. METHODS: 75 morbidly obese patients who underwent silicone ring RYGBP between Oct 1995 and Dec 1999, 18 men and 57 women, were studied. Demographic data, nutritional status and the presence of co-morbidities (type 2 diabetes, hypertension, sleep apnea, dyslipidemia) were accessed. Pre- and postoperative BMI were registered, along with excess weight loss (EWL). Nutritional deficiencies were accessed by laboratory assays. RESULTS: Mean follow-up was 87 months. Initial BMI was 56.7 +/- 10 kg/m2. After 2 years, BMI had dropped to 29.3 +/- 6.8, and by the last interview BMI was 35.5 +/- 10. %EWL after 2 years was 80.2 +/- 17.3%, and at the end was 71.8 +/- 21.6%. After 2 years, only 1 of the 75 patients (1.33%) had not achieved an EWL of at least 50%. At the end, 23 patients (30.6%) could not maintain this EWL. Resolution of diabetes was 76.5%, arterial hypertension 37.3% and sleep apnea 93.5%. Iron, vitamin B12 and vitamin D were the most common nutritional deficiencies. CONCLUSIONS: Long-term follow-up (5 to 9 years) after the RYGBP was associated with satisfactory mantainance of EWL, and resolution or improvement of the main co-morbidities was observed in the majority of the patients.

Use of noninvasive markers to predict advanced fibrosis/cirrhosis in severe obesity.

BACKGROUND: Nonalcoholic steatohepatitis is observed in 25%-55% of patients with severe obesity and in 2%-12% with bridging fibrosis or cirrhosis. There is currently no noninvasive test for the diagnosis of severe liver fibrosis before bariatric surgery. OBJECTIVES: To determine the best noninvasive test for predicting advanced liver disease in patients with severe obesity. SETTING: University tertiary care hospital, Brazil. METHODS: A cross-sectional retrospective study was conducted with 699 patients with severe obesity undergoing bariatric surgery: 568 without a biopsy (nonbiopsy cohort) and 131 patients who had undergone an intraoperative liver biopsy. The tissues were subjected to histologic diagnosis (Brunt criteria) and classified as advanced fibrosis (stages 3 and 4) or no significant fibrosis (absence of nonalcoholic steatohepatitis and stages 1 or 2). The following predictive indices of cirrhosis were calculated in all patients: aspartate aminotransferase/alanine aminotransferase ratio (AAR), age-platelet (AP) index, aminotransferase-to-platelet ratio index (APRI), cirrhosis discriminant score (CDS), and hepatitis C antiviral long-term treatment against cirrhosis (HALT-C). The cutoff values, sensitivity, specificity, and areas under the receiver operating characteristic curves (AUROCs) were calculated for patients with biopsies. RESULTS: The AUROC of the AAR, AP, APRI, CDS, and HALT-C model for predicting advanced fibrosis or cirrhosis were, respectively, .522, .88, .99, .905, and .921. The calculated cutoff values, sensitivity, and specificity, respectively, were as follows: AAR: .94, .7, .45; AP 5, .7, .93; APRI .44, 1.0, .97; CDS 6, .7, .97; and HALT-C: .76, 1.0, .77. CONCLUSION: APRI index was the best predictor of advanced liver disease in patients with severe obesity.

Strategies, models and biomarkers in experimental non-alcoholic fatty liver disease research.

Non-alcoholic fatty liver disease encompasses a spectrum of liver diseases, including simple steatosis, steatohepatitis, liver fibrosis and cirrhosis and hepatocellular carcinoma. Non-alcoholic fatty liver disease is currently the most dominant chronic liver disease in Western countries due to the fact that hepatic steatosis is associated with insulin resistance, type 2 diabetes mellitus, obesity, metabolic syndrome and drug-induced injury. A variety of chemicals, mainly drugs, and diets is known to cause hepatic steatosis in humans and rodents. Experimental non-alcoholic fatty liver disease models rely on the application of a diet or the administration of drugs to laboratory animals or the exposure of hepatic cell lines to these drugs. More recently, genetically modified rodents or zebrafish have been introduced as non-alcoholic fatty liver disease models. Considerable interest now lies in the discovery and development of novel non-invasive biomarkers of non-alcoholic fatty liver disease, with specific focus on hepatic steatosis. Experimental diagnostic biomarkers of non-alcoholic fatty liver disease, such as (epi)genetic parameters and '-omics'-based read-outs are still in their infancy, but show great promise. In this paper, the array of tools and models for the study of liver steatosis is discussed. Furthermore, the current state-of-art regarding experimental biomarkers such as epigenetic, genetic, transcriptomic, proteomic and metabonomic biomarkers will be reviewed.

Pro-atherosclerotic markers and cardiovascular risk factors one year after liver transplantation.

AIM: To investigate pro-atherosclerotic markers (endothelial dysfunction and inflammation) in patients one year after liver transplantation. METHODS: Forty-four consecutive liver transplant (LT) outpatients who were admitted between August 2009 and July 2010, were followed-up by for 1 year, exhibited no evidences of infection or rejection, all of them underwent tacrolimus-based immunosuppressive regimens were consecutively enrolled. Inflammatory cytokines (TNFα, IFNγ, IL-8, and IL-10), endothelial biomarkers (sVCAM-1, sICAM-1, MPO, adiponectin, PAI-1, SAP, SAA, E-selectin, and MMP-9), high sensitive C-reactive protein, and Framingham risk score (FRS) were assessed. The anthropometric data, aminotransferases, metabolic syndrome features, glucose and lipid profiles, and insulin resistance data were also collected. The LT recipients were compared to 22 biopsy-proven non-alcoholic steatohepatitis (NASH) patients and 20 healthy controls (non-obese, non-diabetics, and non-dyslipidemic). RESULTS: The LT recipients had significantly younger ages and lower body mass indices, aminotransferases, fasting glucose and insulin levels, glucose homeostasis model and metabolic syndrome features than the NASH patients. Classic cardiovascular risk markers, such as Hs-CRP and FRS [2.0 (1.0-8.75)], were lower in the LT patients compared to those observed in the NASH patients (P = 0.009). In contrast, the LT recipients and NASH patients had similar inflammatory and endothelial serum markers compared to the controls (pg/mL): lower IL-10 levels (32.3 and 32.3 vs 62.5, respectively, P = 0.019) and higher IFNγ (626.1 and 411.9 vs 67.9, respectively, P < 0.001), E-selectin (48.5 and 90.03 vs 35.7, respectively, P < 0.001), sVCAM-1 (1820.6 and 1692.4 vs 1167.2, respectively, P < 0.001), and sICAM-1 (230.3 and 259.7 vs 152.9, respectively, P = 0.015) levels. CONCLUSION: Non-obese LT recipients have similar pro-atherosclerotic serum profiles after a short 1-year follow-up period compared to NASH patients, suggesting a high risk of atherosclerosis in this population.

A role for mammalian target of rapamycin (mTOR) pathway in non alcoholic steatohepatitis related-cirrhosis.

UNLABELLED: Non-alcoholic fatty liver disease (NAFLD) encompasses the whole spectrum of steatosis, non-alcoholic steatohepatitis (NASH), and NASH-related cirrhosis (NASH/Cir). Although molecular advances have been made in this field, the pathogenesis of NAFLD is not completely understood. The gene expression profiling associated to NASH/Cir was assessed, in an attempt to better characterize the pathways involved in its etiopathogenesis. METHODS: In the first step, we used cDNA microarray to evaluate the gene expression profiles in normal liver (n=3) and NASH/Cir samples (n=3) by GeneSifter analysis to identify differentially expressed genes and biological pathways. Second, tissue microarray was used to determine immunohistochemical expression of phosphorylated mTOR and 4E-BP1 in 11 normal liver samples, 10 NASH/Cir samples and in 37 samples of cirrhosis of other etiologies to further explore the involvement of the mTOR pathway evidenced by the gene expression analysis. RESULTS: 138 and 106 genes were, respectively, up and down regulated in NASH/Cir in comparison to normal liver. Among the 9 pathways identified as significantly modulated in NASH/Cir, the participation of the mTOR pathway was confirmed, since expression of cytoplasmic and membrane phospho-mTOR were higher in NASH/Cir in comparison to cirrhosis of other etiologies and to normal liver. CONCLUSIONS: Recent findings have suggested a role for the cellular "nutrient sensor" mTOR in NAFLD and the present study corroborates the participation of this pathway in NASH/Cir. Phospho-mTOR evaluation might be of clinical utility as a potential marker for identification of NASH/Cir in cases mistakenly considered as cryptogenic cirrhosis owing to paucity of clinical data.

Yo jyo hen shi ko, a novel Chinese herbal, prevents nonalcoholic steatohepatitis in ob/ob mice fed a high fat or methionine-choline-deficient diet.

BACKGROUND: Oxidative stress plays a role in the pathogenesis of nonalcoholic steatohepatitis (NASH). Yo jyo hen shi ko (YHK) is a complex compound purported to reduce reactive oxygen species (ROS) by blocking the propagation of radical-induced reactions. The aim of this study was to evaluate the role of the effect of YHK in experimental NASH. METHODS: NASH was induced in male ob/ob mice by a high-fat (HF) diet or methionine/choline-deficient (MCD) diet for 4 weeks. YHK-treated animals received YHK solution orally (20 mg/kg/day) in both experimental diets (n=6; each group) while control animals received only vehicle. RESULTS: The MCD and HF groups developed moderate diffuse macrosteatosis, hepatocellular ballooning, and a diffuse inflammatory infiltrate. With the addition of YHK, there was a marked reduction in macrosteatosis in both groups. This was associated with decreased lipoperoxide and reduced glutathione-GSH concentrations as well as reduced serum aminotransferases and improved histological markers of inflammation. These changes were also associated with weight loss in the MCD+YHK group and diminished weight gain in the HF+YHK group. CONCLUSION: YHK therapy blunts the development of macrosteatosis in these models of NASH and significantly reduces markers of oxidative stress. YHK also diminishes weight gain in this obesity prone model. Our findings warrant further study on the mechanisms involved with these effects.

Nonalcoholic steatohepatitis (NASH) in ob/ob mice treated with yo jyo hen shi ko (YHK): effects on peroxisome proliferator-activated receptors (PPARs) and microsomal triglyceride transfer protein (MTP).

YHK has antioxidant properties, has a hypoglycemic effect, and may reduce plasma lipid levels. In this study, we examined the hepatic expression of PPAR-alpha and -gamma and MTP in ob/ob mice receiving or not receiving YHK. Ob/ob mice were assigned to receive oral YHK (20 mg/kg/day) fed solution (methionine/choline-deficient [MCD] diet+YHK group) or vehicle (MCD group) by gavage for 4 weeks. Liver fragments were collected for histologic examination and mRNA isolation. PPAR-alpha and -gamma and MTP gene expression was examined by RT-qPCR. YHK treatment was associated with NASH prevention, weight loss, and reduction of visceral fat and of serum concentrations of aminotransferases in comparison to the MCD group. YHK promoted an increment in PPAR-alpha and MTP and a decrement in PPAR-gamma mRNA contents. These findings suggest that modulation of PPAR-alpha and -gamma and MTP RNA expression may be implicated in the protective effect of YHK in experimental NASH, limiting hepatocyte lipid accumulation.

Hepatic gene expression profile associated with non-alcoholic steatohepatitis protection by S-nitroso-N-acetylcysteine in ob/ob mice.

BACKGROUND/AIMS: To understand the molecular mechanisms underlying non-alcoholic steatohepatitis (NASH) prevention by S-nitroso-N-acetylcysteine (SNAC), an NO donor that inhibits lipid peroxidation, we examined hepatic differentially expressed genes between ob/ob mice receiving or not SNAC treatment concomitantly with a methionine-choline deficient (MCD) diet. METHODS: Ob/ob mice were assigned to receive oral SNAC fed solution (MCD+SNAC group) or vehicle (MCD group) by gavage. After four weeks, histopathological analysis and microarray hybridizations were conducted in liver tissues from groups. GeneSifter system was used to identify differentially expressed genes and pathways according to Gene Ontology. RESULTS: NASH was absent in the MCD+SNAC group and no significant changes in food intake or body weight were observed in comparison to MCD group. After SNAC treatment, several genes belonging to oxidative phosphorylation, fatty acid biosynthesis, fatty acid metabolism and glutathione metabolism pathways were down-regulated in comparison to the MCD group. CONCLUSIONS: SNAC treatment promotes down regulation of several genes from fatty acid (FA) metabolism related pathways, possibly through abrogation of the cytotoxic effects of reactive oxygen species and lipid peroxides with consequent prevention of mitochondrial overload. Further studies are required to investigate the clinical implications of these findings, in attempt to develop novel therapeutic strategies for NAFLD treatment.