Obesity and liver disease: the epidemic of the twenty-first century

Reuniting overnutrition and undernutrition, macronutrients, and micronutrients

Over-nutrition and its late consequences are a dominant theme in medicine today. In addition to the health hazards brought on by over-nutrition, the medical community has recently accumulated a roster of health benefits with obesity, grouped under "obesity paradox." Throughout the world and throughout history until the 20^th century, under-nutrition was a dominant evolutionary force. Under-nutrition brings with it a mix of benefits and detriments that are opposite to and continuous with those of over-nutrition. This continuum yields J-shaped or U-shaped curves relating body mass index to mortality. The overweight have an elevated risk of dying in middle age of degenerative diseases while the underweight are at increased risk of premature death from infectious conditions. Micronutrient deficiencies, major concerns of nutritional science in the 20^th century, are being neglected. This "hidden hunger" is now surprisingly prevalent in all weight groups, even among the overweight. Because micronutrient replacement is safe, inexpensive, and predictably effective, it is now an exceptionally attractive target for therapy across the spectrum of weight and age. Nutrition-related conditions worthy of special attention from caregivers include excess vitamin A, excess vitamin D, and deficiency of magnesium.

Review article: drug-induced liver injury in the context of nonalcoholic fatty liver disease - a physiopathological and clinical integrated view

BACKGROUND

Nonalcoholic fatty disease (NAFLD) is the most common liver disease, since it is strongly associated with obesity and metabolic syndrome pandemics. NAFLD may affect drug disposal and has common pathophysiological mechanisms with drug-induced liver injury (DILI); this may predispose to hepatoxicity induced by certain drugs that share these pathophysiological mechanisms. In addition, drugs may trigger fatty liver and inflammation per se by mimicking NAFLD pathophysiological mechanisms.

AIMS

To provide a comprehensive update on (a) potential mechanisms whereby certain drugs can be more hepatotoxic in NAFLD patients, (b) the steatogenic effects of drugs, and (c) the mechanism involved in drug-induced steatohepatitis (DISH).

METHODS

A language- and date-unrestricted Medline literature search was conducted to identify pertinent basic and clinical studies on the topic.

RESULTS

Drugs can induce macrovesicular steatosis by mimicking NAFLD pathogenic factors, including insulin resistance and imbalance between fat gain and loss. Other forms of hepatic fat accumulation exist, such as microvesicular steatosis and phospholipidosis, and are mostly associated with acute mitochondrial dysfunction and defective lipophagy, respectively. Drug-induced mitochondrial dysfunction is also commonly involved in DISH. Patients with pre-existing NAFLD may be at higher risk of DILI induced by certain drugs, and polypharmacy in obese individuals to treat their comorbidities may be a contributing factor.

CONCLUSIONS

The relationship between DILI and NAFLD may be reciprocal: drugs can cause NAFLD by acting as steatogenic factors, and pre-existing NAFLD could be a predisposing condition for certain drugs to cause DILI. Polypharmacy associated with obesity might potentiate the association between this condition and DILI.

Alcoholic steatohepatitis (ASH) and alcoholic hepatitis (AH): cascade of events, clinical aspects, and pharmacotherapy options

INTRODUCTION

Clinicians caring for patients with alcoholic hepatitis (AH) are often confronted with the question of the best pharmacotherapy to be used.

AREAS COVERED

This article covers metabolic aspects of alcohol as the basis of understanding pharmacotherapy and to facilitate choosing the drug therapeutic options for patients with severe AH.

EXPERT OPINION

Alcoholic steatohepatitis (ASH) and alcoholic hepatitis (AH) as terms are often used interchangeably in scientific literature but a stringent differentiation is recommended for proper clarity. As opposed to ASH, the clinical course of AH is often severe and requires an effective drug treatment strategy, in addition to absolute alcohol abstinence and nutritional support. Drug options include corticosteroids as a first choice and pentoxifylline, an inhibitor of phosphodiesterase, as a second line therapy, especially in patients with contraindications for a corticosteroid therapy such as infections or sepsis. At seven days under corticosteroids, treatment should be terminated in non-responders, and patients must then be evaluated for liver transplantation. Pentoxifylline is not effective as a rescue therapy for these patients. Other treatments such as infliximab, propylthiouracil, N-acetylcysteine, silymarin, colchicine, insulin and glucagon, oxandrolone, testosterone, and polyunsaturated lecithin are not effective in severe AH. For liver transplantation, few patients will be eligible.

Viewpoint: A Contributory Role of Shell Ginger (Alpinia zerumbet (Pers.) B.L. Burtt & R.M. Sm) for Human Longevity in Okinawa, Japan?

The longevity of the population in the Okinawa Islands of Japan has been ascribed to genetic factors and the traditional Okinawa cuisine, which is low in calories and high in plant content. This diet includes shell ginger (Alpinia zerumbet (Pers.) B.L. Burtt & R.M. Sm) of the ginger family (Zingiberaceae). Due to its local popularity, Alpinia zerumbet has become the subject of a good deal of study at the University of the Ryukyus in Okinawa. Personal local experience and review of the literature now suggest that culinary shell ginger may contribute to longevity among the population in Okinawa. This is supported by its abundant phytochemical content, with antioxidant and anti-obesity properties. The major bioactive phytochemicals are dihydro-5,6-dehydrokawain (DDK; 80-410 mg g^-1 fresh weight), 5,6-dehydrokawain (DK; ≤100 mg g^-1), and essential oils, phenols, phenolic acids, and fatty acids (≤150 mg g^-1 each). Further, Alpinia zerumbet extends the lifespan in animals by 22.6%. In conclusion, culinary shell ginger may significantly contribute to human longevity in Okinawa.

Live cell imaging of cytosolic NADH/NAD+ ratio in hepatocytes and liver slices

Fatty liver disease (FLD), the most common chronic liver disease in the United States, may be caused by alcohol or the metabolic syndrome. Alcohol is oxidized in the cytosol of hepatocytes by alcohol dehydrogenase (ADH), which generates NADH and increases cytosolic NADH/NAD⁺ ratio. The increased ratio may be important for development of FLD, but our ability to examine this question is hindered by methodological limitations. To address this, we used the genetically encoded fluorescent sensor Peredox to obtain dynamic, real-time measurements of cytosolic NADH/NAD⁺ ratio in living hepatocytes. Peredox was expressed in dissociated rat hepatocytes and HepG2 cells by transfection, and in mouse liver slices by tail-vein injection of adeno-associated virus (AAV)-encoded sensor. Under control conditions, hepatocytes and liver slices exhibit a relatively low (oxidized) cytosolic NADH/NAD⁺ ratio as reported by Peredox. The ratio responds rapidly and reversibly to substrates of lactate dehydrogenase (LDH) and sorbitol dehydrogenase (SDH). Ethanol causes a robust dose-dependent increase in cytosolic NADH/NAD⁺ ratio, and this increase is mitigated by the presence of NAD⁺-generating substrates of LDH or SDH. In contrast to hepatocytes and slices, HepG2 cells exhibit a relatively high (reduced) ratio and show minimal responses to substrates of ADH and SDH. In slices, we show that comparable results are obtained with epifluorescence imaging and two-photon fluorescence lifetime imaging (2p-FLIM). Live cell imaging with Peredox is a promising new approach to investigate cytosolic NADH/NAD⁺ ratio in hepatocytes. Imaging in liver slices is particularly attractive because it allows preservation of liver microanatomy and metabolic zonation of hepatocytes. NEW & NOTEWORTHY We describe and validate a new approach for measuring free cytosolic NADH/NAD⁺ ratio in hepatocytes and liver slices: live cell imaging with the fluorescent biosensor Peredox. This approach yields dynamic, real-time measurements of the ratio in living, functioning liver cells, overcoming many limitations of previous methods for measuring this important redox parameter. The feasibility of using Peredox in liver slices is particularly attractive because slices allow preservation of hepatic microanatomy and metabolic zonation of hepatocytes.

Significant disparities in risks of diabetes mellitus and metabolic syndrome among chronic hepatitis C virus patients in the U.S

AIM

Diabetes mellitus (DM) and metabolic syndrome (MetSyn) among chronic hepatitis C virus (HCV) patients increases risks for nonalcoholic fatty liver disease (NAFLD) and more rapid progression to hepatocellular carcinoma (HCC). We aim to evaluate the prevalence of DM and MetSyn among HCV patients, focusing on age-specific and race/ethnicity-specific disparities.

METHODS

We retrospectively evaluated 2003-2012 National Health and Nutrition Examination Survey (NHANES) data for age and race disparities in concurrent DM and MetSyn among HCV patients. Multivariate logistic regression models evaluated for independent predictors of DM and MetSyn among HCV patients.

RESULTS

Overall U.S. prevalence of HCV was 1.29% from 2003 to 2012 and prevalence of DM and MetSyn among HCV patients was 17.5% and 35.0%, respectively. Higher rates of DM (36.9% vs. 3.3%, p<0.001) and MetSyn (50.5% vs. 11.7%, p<0.001) were seen among HCV patients ≥60 compared to <40years. The highest rates of DM and MetSyn were seen among African Americans (AA) (DM: 39.1%, MetSyn: 29.2%) and the lowest in non-Hispanic whites (DM: 9.4%, MetSyn: 33.0%). On multivariate regression, patients ≥60 were significantly more likely to have DM compared to patients <40 years (OR 11.90, 95% CI 2.73-52.60, p=0.001); AA were significantly more likely to have DM compared to non-Hispanic whites (OR 2.82, 95% CI 1.53-5.20, p=0.001).

CONCLUSION

Among chronic HCV patients, the highest risk of DM and MetSyn was seen among older patients, African Americans, and women. These groups are at higher risk of cirrhosis and HCC due to concurrent NAFLD.

Prevalence of obesity in elementary school children and its association with dental caries

Objectives

To investigate the prevalence of obesity among elementary school children and to examine the association between obesity and caries activity in the mixed dentition stage.

Methods

This cross-sectional study was conducted in King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia between September 2014 and June 2015 using a multi-stage stratified sample of 915 elementary school children (482 boys, 433 girls) in Jeddah, Saudi Arabia. Anthropometric measurements, consisting of height, weight, body mass index (BMI), and waist circumference (WC), were obtained. Children were classified as underweight/healthy, overweight, or obese and as non-obese or obese according to their BMI and WC, respectively. Each child’s caries experience was assessed using the decay score in the primary and permanent teeth.

Results

Based on BMI, 18% of children were obese, 18% were overweight, and 64% were underweight/normal. Based on WC, 16% of children were obese, and 84% were non-obese. Girls had a significantly higher prevalence of obesity based on WC measurements (p<0.001), but not BMI. Children enrolled in private schools had a significantly higher prevalence of obesity (p<0.05) than those in public schools. For primary and permanent teeth combined, children with higher BMI and WC had a lower prevalence of caries (p<0.05).

Conclusion

The prevalence of obesity was high among male and female elementary school children. Overall caries activity was inversely proportional to BMI and WC.

Epidemiology of Hepatocellular Carcinoma and Intrahepatic Cholangiocarcinoma

Hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC) are the most frequently occurring types of primary liver cancer and together are among the most common incident cancers worldwide. There are a number of modifiable and nonmodifiable HCC and ICC risk factors that have been reported. A review of the existing literature the epidemiology and risk factors for HCC and ICC was performed. There are a number of major infectious, lifestyle, metabolic, and heritable risk factors for both HCC and ICC. Some of these risk factors are either potentially preventable (eg, alcohol and tobacco use) or are currently treatable (eg hepatitis infection). In most cases, the molecular pathway or mechanism by which these etiologic factors cause primary liver cancer has not been well delineated. However, in nearly all cases, it is believed that a given risk factor causes liver injury and inflammation which results in chronic liver disease. Given the rising prevalence of several common HCC and ICC risk factors in the western world, the best opportunities for improving the care of these patients are either through the prevention of modifiable risk factors that are associated with the development of chronic liver disease or the identification of at risk patients, ensuring they are appropriately screened for the development of primary liver cancer, and initiating treatment early.

Bile acids as global regulators of hepatic nutrient metabolism

Bile acids (BA) are synthesized from cholesterol in the liver. They are essential for promotion of the absorption of lipids, cholesterol, and lipid-soluble vitamins from the intestines. BAs are hormones that regulate nutrient metabolism by activating nuclear receptors (farnesoid X receptor (FXR), pregnane X receptor, vitamin D) and G protein-coupled receptors (e.g., TGR5, sphingosine-1-phosphate receptor 2 (S1PR2)) in the liver and intestines. In the liver, S1PR2 activation by conjugated BAs activates the extracellular signal-regulated kinase 1/2 and AKT signaling pathways, and nuclear sphingosine kinase 2. The latter produces sphingosine-1-phosphate (S1P), an inhibitor of histone deacetylases 1/2, which allows for the differential up-regulation of expression of genes involved in the metabolism of sterols and lipids. We discuss here the emerging concepts of the interactions of BAs, FXR, insulin, S1P signaling and nutrient metabolism.

The prevalence of overweight/obesity in high school adolescents in Jeddah and the association of obesity association with dental caries

BACKGROUND

The prevalence of overweight/obesity in children in Saudi Arabia is among the highest in the world. The prevalence of dental caries is also high in Saudi children. Studies on the relationship between caries and obesity in Saudi adolescents are lacking.

OBJECTIVES

To study the prevalence of overweight/obesity in adolescents, and determine any association between obesity and caries.

DESIGN

An analytical cross-sectional study.

SETTING

Private and public schools in Jeddah.

PATIENTS AND METHODS

The study sample comprised high school children from public and private schools selected by multistage stratified random sampling. Height, weight, waist circumference (WC), and body mass index (BMI) were measured for all children, who were then classified as underweight/normal, overweight, or obese according to their BMI values, and nonobese or obese according to their WC values. The presence of caries was assessed using the Association of State and Territorial Dental Directors criteria.

MAIN OUTCOME MEASURE(S)

The prevalence of overweight/obesity and the association of obesity with the number of decayed permanent teeth.

RESULTS

801 high school children (48% boys, 49% from public schools) with a mean (SD) age of 16.5 (0.9) years. When the BMI classification was used, 24%, 16%, and 60% adolescents were obese, overweight, and underweight/normal, respectively. When the WC classification was used, 19% and 81% were obese and nonobese, respectively. Obesity was more prevalent in boys and in students attending private schools (P < .05). The number of decayed permanent teeth showed a very weak and insignificant correlation with BMI and WC.

CONCLUSION

One in every four adolescents residing in Jeddah was obese, with a high obesity prevalence in boys and in children attending private schools. The prevalence of caries in the permanent dentition was not associated with BMI or WC.

LIMITATIONS

It was difficult to establish temporality in this cross-sectional study. Data on common risk factors were not adjusted for in the analyses.

Connexin32 deficiency is associated with liver injury, inflammation and oxidative stress in experimental non-alcoholic steatohepatitis

Non-alcoholic steatohepatitis is a highly prevalent liver pathology featured by hepatocellular fat deposition and inflammation. Connexin32, which is the major building block of hepatocellular gap junctions, has a protective role in hepatocarcinogenesis and is downregulated in chronic liver diseases. However, the role of connexin32 in non-alcoholic steatohepatitis remains unclear. Connexin32-/- mice and their wild-type littermates were fed a choline-deficient high-fat diet. The manifestation of non-alcoholic steatohepatitis was evaluated based on a battery of clinically relevant read-outs, including histopathological examination, diverse indicators of inflammation and liver damage, in-depth lipid analysis, assessment of oxidative stress, insulin and glucose tolerance, liver regeneration and lipid-related biomarkers. Overall, more pronounced liver damage, inflammation and oxidative stress were observed in connexin32-/- mice compared to wild-type animals. No differences were found in insulin and glucose tolerance measurements and liver regeneration. However, two lipid-related genes, srebf1 and fabp3, were upregulated in Cx32-/- mice in comparison with wild-type animals. These findings suggest that connexin32-based signalling is not directly involved in steatosis as such, but rather in the sequelae of this process, which underlie progression of non-alcoholic steatohepatitis.

Recent advances in understanding the role of adipocytokines during non-alcoholic fatty liver disease pathogenesis and their link with hepatokines

Non-alcoholic fatty liver disease (NAFLD) is currently considered the main cause of chronic liver disease worldwide. Mechanisms leading to the development and progression of this disease are topics of great interest for researchers and clinicians. The current multi-hit hypothesis has thrown the crosstalk between liver and adipose tissue into sharp focus. It is well known that adipose tissue produces circulating factors, known as adipocytokines, which exert several effects on liver cells, promoting the onset of NAFLD and its progression to non-alcoholic steatohepatitis in obese subjects. In a similar way, hepatocytes may also respond to obesogenic stimuli by producing and releasing hepatokines into the circulation. Here, the authors provide an overview of recent advances in our understanding of the role of the most relevant adipocytokines and hepatokines in NAFLD pathogenesis, highlighting their possible molecular and functional interactions.

Hepatocyte TAZ/WWTR1 Promotes Inflammation and Fibrosis in Nonalcoholic Steatohepatitis

Nonalcoholic steatohepatitis (NASH) is a leading cause of liver disease worldwide. However, the molecular basis of how benign steatosis progresses to NASH is incompletely understood, which has limited the identification of therapeutic targets. Here we show that the transcription regulator TAZ (WWTR1) is markedly higher in hepatocytes in human and murine NASH liver than in normal or steatotic liver. Most importantly, silencing of hepatocyte TAZ in murine models of NASH prevented or reversed hepatic inflammation, hepatocyte death, and fibrosis, but not steatosis. Moreover, hepatocyte-targeted expression of TAZ in a model of steatosis promoted NASH features, including fibrosis. In vitro and in vivo mechanistic studies revealed that a key mechanism linking hepatocyte TAZ to NASH fibrosis is TAZ/TEA domain (TEAD)-mediated induction of Indian hedgehog (Ihh), a secretory factor that activates fibrogenic genes in hepatic stellate cells. In summary, TAZ represents a previously unrecognized factor that contributes to the critical process of steatosis-to-NASH progression.

Noninvasive imaging methods to determine severity of nonalcoholic fatty liver disease and nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) is now the most common form of liver disease in developed countries, with an estimated prevalence of 20%-30% and increasing to as high as 90% in diabetics. As the rates of NAFLD continue to rise in parallel with those of the obesity pandemic, it is increasingly important to differentiate those patients with the highest risk of progression to fibrosis and cirrhosis. In fact, those patients with nonalcoholic steatohepatitis (NASH) and fibrosis are at the greatest risk of progression to advanced disease, cirrhosis, and hepatocellular cancer and are more likely to develop liver-related mortality. Thus, it is critically important to distinguish between NASH and non-NASH NAFLD. Whereas liver biopsy remains the gold standard for staging of disease, complications of this procedure and other well-recognized limitations make it impractical for widespread use given the overall NAFLD disease burden. Noninvasive imaging modalities are increasingly being utilized to evaluate and stage NAFLD in patients with such a wide spectrum of disease. In this article, the role of these new and promising noninvasive imaging modalities to assess disease severity in NAFLD are reviewed. (Hepatology 2016;64:2234-2243).

Piceatannol Exerts Anti-Obesity Effects in C57BL/6 Mice through Modulating Adipogenic Proteins and Gut Microbiota

Obesity is a global health concern. Piceatannol (Pic), an analog of resveratrol (Res), has many reported biological activities. In this study, we investigated the anti-obesity effect of Pic in a high-fat diet (HFD)-induced obese animal model. The results showed that Pic significantly reduced mouse body weight in a dose-dependent manner without affecting food intake. Serum total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL) levels, and blood glucose (GLU) were significantly lowered in Pic-treated groups. Pic significantly decreased the weight of liver, spleen, perigonadal and retroperitoneal fat compared with the HFD group. Pic significantly reduced the adipocyte cell size of perigonadal fat and decreased the weight of liver. Pic-treated mice showed higher phosphorylated adenosine 5′-monophosphate-activated protein kinase (pAMPK) and phosphorylated acetyl-CoA carboxylase (pACC) protein levels and decreased protein levels of CCAAT/enhancer-binding protein C/EBPα, peroxisome proliferator-activated receptor PPARγ and fatty acid synthase (FAS), resulting in decreased lipid accumulation in adipocytes and the liver. Pic altered the composition of the gut microbiota by increasing Firmicutes and Lactobacillus and decreasing Bacteroidetes compared with the HFD group. Collectively, these results suggest that Pic may be a candidate for obesity treatment.

Genetic factors that affect nonalcoholic fatty liver disease: A systematic clinical review

AIM: To investigate roles of genetic polymorphisms in non-alcoholic fatty liver disease (NAFLD) onset, severity, and outcome through systematic literature review.

METHODS: The authors conducted both systematic and specific searches of PubMed through December 2015 with special emphasis on more recent data (from 2012 onward) while still drawing from more historical data for background. We identified several specific genetic polymorphisms that have been most researched and, at this time, appear to have the greatest clinical significance on NAFLD and similar hepatic diseases. These were further investigated to assess their specific effects on disease onset and progression and the mechanisms by which these effects occur.

RESULTS: We focus particularly on genetic polymorphisms of the following genes: PNPLA3, particularly the p. I148M variant, TM6SF2, particularly the p. E167K variant, and on variants in FTO, LIPA, IFNλ4, and iron metabolism, specifically focusing on HFE, and HMOX-1. We discuss the effect of these genetic variations and their resultant protein variants on the onset of fatty liver disease and its severity, including the effect on likelihood of progression to cirrhosis and hepatocellular carcinoma. While our principal focus is on NAFLD, we also discuss briefly effects of some of the variants on development and severity of other hepatic diseases, including hepatitis C and alcoholic liver disease. These results are briefly discussed in terms of clinical application and future potential for personalized medicine.

CONCLUSION: Polymorphisms and genetic factors of several genes contribute to NAFLD and its end results. These genes hold keys to future improvements in diagnosis and management.

NLRP3 inflammasome as a target of berberine in experimental murine liver injury: interference with P2X7 signalling

Berberine (BRB) is commonly used in herbal medicine, but its mechanisms of action are poorly understood. In the present study, we tested BRB in steatohepatitis induced by a methionine- and choline-deficient (MCD) diet, in acute acetaminophen intoxication and in cultured murine macrophages. BRB markedly improved parameters of liver injury and necroinflammation induced by the MCD diet, although increased mortality was observed by mechanisms independent of bacterial infections or plasma levels of BRB. The MCD diet induced up-regulation of all components of the NLRP3 (NACHT, LRR and PYD domain-containing protein 3) inflammasome, and increased hepatic levels of mature IL-1β (interleukin 1β). All of these parameters were significantly reduced in mice treated with BRB. In mice administered an acetaminophen overdose, a model dependent on inflammasome activation, BRB reduced mortality and ALT (alanine aminotransferase) elevation, and limited the expression of inflammasome components. In vitro, LPS (lipopolysaccharide)-induced activation of NLRP3 inflammasome in RAW264.7 murine macrophages was markedly decreased by pre-incubation with BRB. BRB significantly limited the activation of the purinergic receptor P2X7, involved in the late phases of inflammasome activation. Upon P2X7 knockdown, the ability of BRB to block LPS-induced secretion of IL-1β was lost. These data indicate that administration of BRB ameliorates inflammation and injury in two unrelated murine models of liver damage. We demonstrate for the first time that BRB interferes with activation of the NLRP3 inflammasome pathway in vivo and in vitro, through a mechanism based on interference with activation of P2X7, a purinergic receptor involved in inflammasome activation.

5-Demethylnobiletin and 5-Acetoxy-6,7,8,3',4'-pentamethoxyflavone Suppress Lipid Accumulation by Activating the LKB1-AMPK Pathway in 3T3-L1 Preadipocytes and High Fat Diet-Fed C57BL/6 Mice

Polymethoxyflavones (PMFs) and hydroxylated polymethoxyflavones (HPMFs), such as nobiletin (Nob) and 5-demethylnobiletin (5-OH-Nob), are unique flavonoids that are found exclusively in citrus peels. Nobiletin has been shown to suppress adipogenesis in vitro, but the antiadipogenic activity of 5-OH-Nob has not been investigated. Both nobiletin and 5-OH-Nob have poor aqueous solubility and low oral bioavailability. We employed chemical modification to produce the acetyl derivative of 5-OH-Nob, that is, 5-acetyloxy-6,7,8,3',4'-pentamethoxyflavone (5-Ac-Nob), to improve its bioavailability and bioactive efficiency. We found that 5-Ac-Nob reduced triacylglycerol (TG) content to a greater extent than 5-OH-Nob in 3T3-L1 preadipocytes. Orally administered 5-Ac-Nob resulted in a significant reduction in body weight, intra-abdominal fat, plasma and liver TG levels, and plasma cholesterol level in high fat diet-induced obese male C57BL/6J mice. The 5-Ac-Nob treatment decreased lipid accumulation by triggering the adenosine 5'-monophosphate-activated protein kinase (AMPK) pathway to alter transcriptional factors or lipogenesis-related enzymes in vivo and in vitro.

The rationale for targeting TGF-β in chronic liver diseases

BACKGROUND

Transforming growth factor (TGF)-β is a pluripotent cytokine that displays several tissue-specific biological activities. In the liver, TGF-β is considered a fundamental molecule, controlling organ size and growth by limiting hepatocyte proliferation. It is involved in fibrogenesis and, therefore, in worsening liver damage, as well as in triggering the development of hepatocellular carcinoma (HCC). TGF-β is known to act as an oncosuppressor and also as a tumour promoter in HCC, but its role is still unclear.

DESIGN

In this review, we discuss the potential role of TGF-β in regulating the tumoural progression of HCC, and therefore the rationale for targeting this molecule in patients with HCC.

RESULTS

A considerable amount of experimental preclinical evidence suggests that TGF-β is a promising druggable target in patients with HCC. To support this hypothesis, a phase II clinical trial is currently ongoing using a TGF-β pathway inhibitor, and results will soon be available.

CONCLUSIONS

The identification of new TGF-β related biomarkers will help to select those patients most likely to benefit from therapy aimed at inhibiting the TGF-β pathway. New formulations that may provide a more controlled and sustained delivery of the drug will improve the therapeutic success of such treatments.

Outcomes of abdominal surgery in patients with liver cirrhosis

Patients suffering from liver cirrhosis (LC) frequently require non-hepatic abdominal surgery, even before liver transplantation. LC is an important risk factor itself for surgery, due to the higher than average associated morbidity and mortality. This high surgical risk occurs because of the pathophysiology of liver disease itself and to the presence of contributing factors, such as coagulopathy, poor nutritional status, adaptive immune dysfunction, cirrhotic cardiomyopathy, and renal and pulmonary dysfunction, which all lead to poor outcomes. Careful evaluation of these factors and the degree of liver disease can help to reduce the development of complications both during and after abdominal surgery. In the emergency setting, with the presence of decompensated LC, alcoholic hepatitis, severe/advanced LC, and significant extrahepatic organ dysfunction conservative management is preferred. A multidisciplinary, individualized, and specialized approach can improve outcomes; preoperative optimization after risk stratification and careful management are mandatory before surgery. Laparoscopic techniques can also improve outcomes. We review the impact of LC on surgical outcome in non-hepatic abdominal surgeries required in this cirrhotic population before, during, and after surgery.

Effect of blueberry on expression of Bcl-2 and Bax in non-alcoholic fatty liver disease in mice

AIM: To investigate the effect of blueberry on non-alcoholic fatty liver disease in mice and the underlying mechanism.

METHODS: Forty healthy SD mice were randomly divided into a normal control group, a blueberry group, a curcumin group and a model group. The normal control group was given a normal diet, and the other groups were all given a high fat diet. The blueberry group was intragastrically given blueberry juice [15 mL/(kg•d)], the curcumin group was given curcumin solution [200 mg/(kg•d)], and the other groups were given physiological saline daily. At the end of 12 wk, all mice were sacrificed. Liver cell injury and fat deposition were assessed by HE staining and oil red O staining, respectively. The levels of alanine transaminase (ALT), aspartate transaminase (AST), triglyeride (TG) and total cholesterol (TC) in serum were detected with an automatic biochemical analyzer. Hepatic TG, TC, malondialdehyde (MDA), glutathione (GSH) and superoxide dismutase (SOD) were quantified by ELISA. The expression of Bcl-2 and Bax in liver tissue was detected by immunohistochemistry, Western blot and RT-PCR.

RESULTS: Compared to the model group, the blueberry and curcumin groups showed significantly decreased lipid accumulation, serum levels of ALT, AST, TG and TC (P < 0.01), and hepatic levels of TG and MDA (P < 0.01), and increased GSH contents and SOD activity (P < 0.01). Compared to the model group, the blueberry and curcumin groups also showed significantly increased Bcl-2 mRNA and protein expression (P < 0.01), significantly decreased Bax mRNA and protein expression (P < 0.01), and significantly increased Bcl-2/Bax ratio (P < 0.01).

CONCLUSION: Blueberry has a protective effect on non-alcoholic fatty liver disease in mice, and the mechanism may be associated with up-regulating the Bcl-2 expression, down-regulating Bax expression, correcting balance disorders, and enhancing the body's antioxidant ability to inhibit liver cell apoptosis.

The Selective SGLT2 Inhibitor Ipragliflozin Has a Therapeutic Effect on Nonalcoholic Steatohepatitis in Mice

Background & Aims

In recent years, nonalcoholic steatohepatitis (NASH) has become a considerable healthcare burden worldwide. Pathogenesis of NASH is associated with type 2 diabetes mellitus (T2DM) and insulin resistance. However, a specific drug to treat NASH is lacking. We investigated the effect of the selective sodium glucose cotransporter 2 inhibitor (SGLT2I) ipragliflozin on NASH in mice.

Methods

We used the Amylin liver NASH model (AMLN), which is a diet-induced model of NASH that results in obesity and T2DM. AMLN mice were fed an AMLN diet for 20 weeks. SGLT2I mice were fed an AMLN diet for 12 weeks and an AMLN diet with 40 mg ipragliflozin/kg for 8 weeks.

Results

AMLN mice showed steatosis, inflammation, and fibrosis in the liver as well as obesity and insulin resistance, features that are recognized in human NASH. Ipragliflozin improved insulin resistance and liver injury. Ipragliflozin decreased serum levels of free fatty acids, hepatic lipid content, the number of apoptotic cells, and areas of fibrosis; it also increased lipid outflow from the liver.

Conclusions

Ipragliflozin improved the pathogenesis of NASH by reducing insulin resistance and lipotoxicity in NASH-model mice. Our results suggest that ipragliflozin has a therapeutic effect on NASH with T2DM.

Factors affecting awareness of non-alcoholic fatty liver disease among the general public and health care providers

Because of the indolent asymptomatic nature of non-alcoholic fatty liver disease (NAFLD), it is often neglected. However, more and more evidence has suggested that NAFLD is not a benign disease and it can progress to liver cirrhosis and hepatocellular carcinoma. Patients with NAFLD have higher mortality, mainly due to liver and cardiovascular diseases, compared with the overall population. Earlier recognition of NAFLD can slow its progression, prevent complications and reduce cardiovascular-related outcomes. However, current estimates of NAFLD awareness indicate that the level of awareness of NAFLD among both the general public and health care providers remains unacceptably low. Understanding the awareness of NAFLD and identifying the related factors could help guide the implementation of awareness efforts and result in more optimized disease prevention and management.

Nonalcoholic Fatty Liver Disease Review: Diagnosis, Treatment, and Outcomes

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of abnormal serum aminotransferase levels in both developed and developing countries. Patients with nonalcoholic steatohepatitis (NASH), a subset of NAFLD, are at risk for progressive liver disease and in need of effective treatment options. A practical approach may be pursued by identifying patients with NAFLD with the highest likelihood for histologic evidence of NASH. Despite decades of clinical trials, no single treatment can be recommended to all patients with NASH. Importantly, there is no evidence that pioglitazone or vitamin E improves fibrosis. Bariatric surgeries may improve hepatic histology in morbidly obese patients with NASH, although randomized clinical trials are lacking. Currently, NASH is the second leading etiology of liver disease among adults awaiting liver transplantation in the United States. The primary and secondary prevention of NAFLD may require aggressive strategies for managing obesity, diabetes, and metabolic syndrome.

The promise of metabolic phenotyping in gastroenterology and hepatology

Disease risk and treatment response are determined, at the individual level, by a complex history of genetic and environmental interactions, including those with our endogenous microbiomes. Personalized health care requires a deep understanding of patient biology that can now be measured using a range of '-omics' technologies. Patient stratification involves the identification of genetic and/or phenotypic disease subclasses that require different therapeutic strategies. Stratified medicine approaches to disease diagnosis, prognosis and therapeutic response monitoring herald a new dimension in patient care. Here, we explore the potential value of metabolic profiling as applied to unmet clinical needs in gastroenterology and hepatology. We describe potential applications in a number of diseases, with emphasis on large-scale population studies as well as metabolic profiling on the individual level, using spectrometric and imaging technologies that will leverage the discovery of mechanistic information and deliver novel health care solutions to improve clinical pathway management.

Non-alcoholic steatohepatitis-related liver cirrhosis is increasing in China: a ten-year retrospective study

OBJECTIVE

Little is known about metabolic factors in cirrhotic patients in China. Therefore, we aimed to quantify the prevalence of both metabolic factors and non-alcoholic steatohepatitis-related liver cirrhosis in China.

METHODS

The medical records of 1,582 patients diagnosed with liver cirrhosis from June 2003 to July 2013 at Daping Hospital (Chongqing, China) were retrospectively reviewed through a computer-generated search.

RESULTS

Serum hepatitis B virus surface antigen was present in 1,083 (68.5%) patients, and hepatitis B was found to be the only etiological factor in 938 (59.3%) of all patients. Obesity, diabetes mellitus, and arterial hypertension were observed in 229 (14.5%), 159 (10.1%), and 129 (8.2%) patients, respectively. From 2012-2013, the proportion of non-alcoholic steatohepatitis-related liver cirrhosis increased to 3.2%, whereas the average proportion of non-alcoholic steatohepatitis-related liver cirrhosis in the previous ten years was 1.9%. The incidence of hepatocellular carcinoma was much higher in males than in females (6.3% vs. 3.7%, respectively, p=0.036). Obesity and diabetes mellitus did not significantly increase the incidence of hepatocellular carcinoma in the whole cirrhotic group. The presence of hepatitis B virus was the only risk factor for hepatocellular carcinoma in cirrhotic patients (p<0.001).

CONCLUSIONS

Although hepatitis B virus remains the main etiology of liver cirrhosis in China, steatohepatitis-related liver cirrhosis is increasing in frequency. Hepatitis B virus was the sole significant risk factor for hepatocellular carcinoma in the whole cirrhotic group in the present study, in contrast to obesity and diabetes mellitus, for which only a trend of increased hepatocellular carcinoma was found.

The Potential Role of Iron and Copper in Pediatric Obesity and Nonalcoholic Fatty Liver Disease

Obesity is a rapidly growing health problem and is paralleled by a multitude of comorbidities, including nonalcoholic fatty liver disease (NAFLD). NAFLD has become the most common chronic liver disease in both adults and children. The current understanding of NAFLD is still fragmentary. While simple steatosis is characterized by the interplay between excessive free fatty acid accumulation and hepatic insulin resistance, the progression to NASH has been related to oxidative stress and a proinflammatory state with dysbalanced adipokine, cytokine levels, and endotoxin-mediated immune response. In addition, oxidative stress has been suggested to play a central role for the sequelae leading to NASH. Trace elements are critical in regulatory, immunologic, and antioxidant functions resulting in protection against inflammation and peroxidation and consequently against the known comorbidities of obesity. Disruptions of the metal detoxification processes located in the liver are plausibly related to NAFLD development via oxidative stress. Perturbations of iron and copper (Cu) homeostasis have been shown to contribute to the pathogenesis of NAFLD. This review presents current data from pediatric studies. In addition, data from adult studies are summarized where clinical relevance may be extrapolated to pediatric obesity and NAFLD.

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.

Ipragliflozin, an SGLT2 inhibitor, exhibits a prophylactic effect on hepatic steatosis and fibrosis induced by choline-deficient l-amino acid-defined diet in rats

Ipragliflozin is a selective sodium glucose cotransporter 2 (SGLT2) inhibitor that increases urinary glucose excretion by inhibiting renal glucose reabsorption and thereby causes a subsequent antihyperglycemic effect. As nonalcoholic fatty liver disease (NAFLD), including nonalcoholic steatohepatitis (NASH), is closely linked to metabolic diseases such as obesity and diabetes, we investigated the effect of ipragliflozin on NAFLD in rats fed a choline-deficient l-amino acid-defined (CDAA) diet. Five weeks after starting the CDAA diet, rats exhibited hepatic triglyceride (TG) accumulation, fibrosis, and mild inflammation. Repeated oral administration of ipragliflozin (3mg/g, once daily for 5 weeks) prevented both hepatic TG accumulation (188 vs.290 mg/g tissue vehicle-treated group; P<0.001) and large lipid droplet formation. Further, ipragliflozin exerted a prophylactic effect on liver fibrosis, as indicated by a marked decrease in hydroxyproline content and fibrosis score. Pioglitazone, which is known to be effective on hepatic fibrosis in CDAA diet-fed rats as well as NASH patients with type 2 diabetes mellitus (T2DM), also exerted a mild prophylactic effect on fibrosis, but not on hepatic TG accumulation or inflammation. In conclusion, ipragliflozin prevented hepatic TG accumulation and fibrosis in CDAA-diet rats. These findings suggest the therapeutic potential of ipragliflozin for patients with NAFLD.

The Effect of Chlorella vulgaris Supplementation on Liver En-zymes, Serum Glucose and Lipid Profile in Patients with Non-Alcoholic Fatty Liver Disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is becoming a public health problem worldwide and using microalgae is a new approach on its treatment. The aim of this study was to investigate the effect of Chlorella vulgaris supplementation on liver enzymes, serum glucose and lipid profile in patients with NAFLD.

METHODS

This double-blind randomized placebo-controlled clinical trial was conducted on 60 NAFLD patients from specialized clinics of Tabriz University of Medical Sciences from December 2011 to July 2012. The subjects were randomly allocated into 2 groups: 1) "intervention" (n=30) received 400 mg/day vitamin E plus four 300 mg tablets of Chlorella vulgaris and, 2) "placebo" (n=30) received 400 mg/day vitamin E and four placebo tablets per day for 8 weeks. Weight, liver enzymes and metabolic factors were assessed in fasting serum and dietary data was collected at baseline and end of the study.

RESULTS

Weight, liver enzymes, fasting blood sugar (FBS) and lipid profile decreased significantly in both groups (P<0.05). The differences in weight, ALP and FBS between the two groups were statistically significant (P=0.01, P=0.04 and P=0.02, respectively).

CONCLUSION

C. vulgaris seems to improve FBS and lipid profile and therefore could be considered as an effective complementary treatment in NAFLD.