Adiponectin: a key playmaker adipocytokine in non-alcoholic fatty liver disease. Clin Exp Med. 2014;14:121-131. [PMID: 23292294 DOI: 10.1007/s10238-012-0227-0]

Possible protective effect of natural flavanone naringenin-reduced graphene oxide nanosheets on nonalcoholic fatty liver disease

Utilizing naringenin as a safe, natural compound for reducing graphene oxide and to determine whether Nar-RGO more effectively mitigates the harmful effects of HFFD-induced NAFLD compared to crude naringenin. Using a straightforward experimental setup, we utilize the bioactive flavonoid naringenin (NAR) as the reducing agent to synthesize naringenin-reduced graphene oxide nanosheets (Nar-RGO). Naringenin loading on graphene oxide was validated using electroscopic methods (SEM and TEM) and zeta potential measurements. Utilization of reduced graphene oxide for naringenin encapsulation resulted in a significant improvement in hepatic steatosis, insulin resistance, oxidative stress, and signs of inflammation in HFFD-induced NAFLD compared to crude naringenin. This study demonstrates that Nar-RGO exhibits significantly greater efficacy compared to free naringenin. Therefore, it can be used as a promising medicine in counteracting high-fat-fructose diet (HFFD)-induced NAFLD.

Sex-Specific Effects of Long-Term Antipsychotic Drug Treatment on Adipocyte Tissue and the Crosstalk to Liver and Brain in Rats

Antipsychotic drug (APD) medication can lead to metabolic dysfunctions and weight gain, which together increase morbidity and mortality. Metabolically active visceral adipose tissue (VAT) in particular plays a crucial role in the etiopathology of these metabolic dysregulations. Here, we studied the effect of 12 weeks of drug medication by daily oral feeding of clozapine and haloperidol on the perirenal fat tissue as part of VAT of male and female Sprague Dawley rats in the context of complex former investigations on brain, liver, and blood. Adipocyte area values were determined, as well as triglycerides, non-esterified fatty acids (NEFAs), glucose, glycogen, lactate, malondialdehyde equivalents, ferric iron and protein levels of Perilipin-A, hormone-sensitive-lipase (HSL), hepcidin, glucose transporter-4 (Glut-4) and insulin receptor-ß (IR-ß). We found increased adipocyte mass in males, with slightly higher adipocyte area values in both males and females under clozapine treatment. Triglycerides, NEFAs, glucose and oxidative stress in the medicated groups were unchanged or slightly decreased. In contrast to controls and haloperidol-medicated rats, perirenal adipocyte mass and serum leptin levels were not correlated under clozapine. Protein expressions of perilipin-A, Glut-4 and HSL were decreased under clozapine treatment. IR-ß expression changed sex-specifically in the clozapine-medicated groups associated with higher hepcidin levels in the perirenal adipose tissue of clozapine-treated females. Taken together, clozapine and haloperidol had a smaller effect than expected on perirenal adipose tissue. The perirenal adipose tissue shows only weak changes in lipid and glucose metabolism. The main changes can be seen in the proteins examined, and probably in their effect on liver metabolism.

The promising roles of medicinal plants and bioactive compounds on hepatic lipid metabolism in the treatment of non-alcoholic fatty liver disease in animal models: molecular targets

Imbalance in hepatic lipid metabolism can lead to an abnormal triglycerides deposition in the hepatocytes which can cause non-alcoholic fatty liver disease (NAFLD). Four main mechanisms responsible for regulating hepatic lipid metabolism are fatty acid uptake, de novo lipogenesis, lipolysis and fatty acid oxidation. Controlling the expression of transcription factors at molecular level plays a crucial role in NAFLD management. This paper reviews various medicinal plants and their bioactive compounds emphasising mechanisms involved in hepatic lipid metabolism, other important NAFLD pathological features, and their promising roles in managing NAFLD through regulating key transcription factors. Although there are many medicinal plants popularly investigated for NAFLD treatment, there is still little information and scientific evidence available and there has been no research on clinical trials scrutinised on this matter. This review also aims to provide molecular information of medicinal plants in NALFD treatment that might have potentials for future scientifically controlled studies.

Macrophage metabolism in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) and its inflammatory and often progressive subtype nonalcoholic steatohepatitis (NASH), have emerged as significant contributors to hepatic morbidity worldwide. The pathophysiology of NAFLD/NASH is multifaceted, variable, and remains incompletely understood. The pivotal role of liver-resident and recruited macrophages in the pathogenesis of NAFLD and NASH is widely acknowledged as a crucial factor in innate immunity. The remarkable plasticity of macrophages enables them to assume diverse activation and polarization states, dictated by their immunometabolism microenvironment and functional requirements. Recent studies in the field of immunometabolism have elucidated that alterations in the metabolic profile of macrophages can profoundly influence their activation state and functionality, thereby influencing various pathological processes. This review primarily focuses on elucidating the polarization and activation states of macrophages, highlighting the correlation between their metabolic characteristics and the transition from pro-inflammatory to anti-inflammatory phenotypes. Additionally, we explore the potential of targeting macrophage metabolism as a promising therapeutic approach for the management of NAFLD/NASH.

Effects of Hydroxycitric Acid Supplementation on Body Composition, Obesity Indices, Appetite, Leptin, and Adiponectin of Women with NAFLD on a Calorie-Restricted Diet

Background

This trial assessed the effects of a calorie-restricted diet (CRD) with hydroxycitric acid (HCA) supplementation on appetite-regulating hormones, obesity indices, body composition, and appetite in women with nonalcoholic fatty liver disease (NAFLD).

Methods

This study was carried out on 44 overweight/obese women with NAFLD. The patients were randomly assigned into two groups, namely, "Intervention group" (receiving individual CRD plus HCA tablets per day) and "Control group" (receiving only CRD) for eight weeks. Obesity indices, body composition, appetite status, and serum levels of leptin and adiponectin were assessed before and after the intervention.

Results

Forty patients completed the trial. At the end of the trial, although significant reductions were found in most of the studied obesity indices in the intervention group, there was only a significant decrease in waist circumference and waist-to-height ratio in the control group. Fat mass and muscle mass significantly decreased in the intervention group (p=0.044 and p=0.024, respectively), and the reduction in visceral fat in the intervention group was significantly greater than that in the control group (-0.49 kg vs -0.37 kg, p=0.024). Intra- and intergroup differences in serum leptin and adiponectin levels and their ratios before and after the trial were not significant. We found a negative and marginally significant correlation between percent of changes in serum adiponectin level and percent of changes in visceral adipose tissue (VAT) (r = -0.429, p=0.067) and BMI (r = -0.440, p=0.059) as well as an inverse relationship between percent of changes in leptin/adiponectin with VAT (r = -0.724, p < 0.001) in the intervention group.

Conclusion

HCA plus weight loss diet could significantly reduce visceral adipose tissue without any significant changes in serum leptin and adiponectin levels.

Deficiency of Adipose Aryl Hydrocarbon Receptor Protects against Diet-Induced Metabolic Dysfunction through Sexually Dimorphic Mechanisms

The molecular mechanisms underlying diet-induced obesity are complex and remain unclear. The activation of the aryl hydrocarbon receptor (AhR), a xenobiotic sensor, by obesogens may contribute to diet-induced obesity through influences on lipid metabolism and insulin resistance acting at various sites, including adipose tissue. Thus, our hypothesis was that conditional AhR depletion, specifically from mature adipose tissue (CadKO), would improve high-fat diet (HFD)-induced metabolic dysfunction. CadKO protects mice from HFD-induced weight gain. CadKO females eat fewer calories, leading to increased energy expenditure (EE) and improved glucose tolerance on HFD. Our exploration of adipose tissue biology suggests that the depletion of AhR from adipocytes provides female mice with an increased capacity for adipogenesis and lipolysis, allowing for the maintenance of a healthy adipocyte phenotype. The HFD-induced leptin rise was reduced in CadKO females, but the hypothalamic leptin receptor (LepR) was increased in the energy regulatory regions of the hypothalamus, suggesting an increased sensitivity to leptin. The estrogen receptor α (ERα) was higher in CadKO female adipose tissue and the hypothalamus. CadKO males displayed a delayed progression of obesity and insulin resistance. In males, CadKO ameliorated proinflammatory adipocytokine secretion (such as TNFα, IL1β, IL6) and displayed reduced inflammatory macrophage infiltration into adipose depots. Overall, CadKO improves weight control and systemic glucose homeostasis under HFD challenge but to a more profound extent in females. CadKO facilitates a lean phenotype in females and mediates healthy adipose-hypothalamic crosstalk. In males, adipose-specific AhR depletion delays the development of obesity and insulin resistance through the maintenance of healthy crosstalk between adipocytes and immune cells.

Spotlight on liver macrophages for halting injury and progression in non-alcoholic fatty liver disease

INTRODUCTION

Non-alcoholic fatty liver disease (NAFLD) is considered the hepatic manifestation of the metabolic syndrome and is rapidly emerging as the leading cause of liver-related morbidity and mortality. Macrophages play an essential role in the development and progression of NAFLD.

AREAS COVERED

In this review, we provide an update on recent studies of drugs, which directly or indirectly affect macrophages in NAFLD, and discuss the implication of macrophage biomarkers to monitor the disease stage and progression/regression.

EXPERT OPINION

There is an unmet need for better understanding of disease pathogenesis from hepatic fat accumulation to disease progression with inflammation and fibrosis. We expect that future research will uncover additional objects/pathways as treatment targets. We speculate that this will involve better characterization of the gut microbiome, damage-associated molecular patterns (DAMPS) or molecules and pathways involved in development of DAMPS, and advanced molecular biology studies including single-cell sequencing of macrophage subpopulations. In addition, we speculate that studies focusing on pharmaceuticals that improve insulin resistance, diminish the metabolic syndrome and reduce fibrosis will prevail.

Inflammatory Cytokines, Adipocytokines, and Th17/Treg Balance in Patients with Nonalcoholic Fatty Liver Disease following Administration of Dahuang Zhechong Pills

Objectives. The occurrence and development of nonalcoholic fatty liver disease (NAFLD) is related to lipid peroxidation, imbalance of inflammatory response factors, and immune function disorder. This study was conducted with the purpose of investigating the expression levels of inflammatory cytokines and adipocytokines and Th17/Treg balance in NAFLD patients treated with Dahuang Zhechong pills (DHZCPs). Methods. The study recruited 100 NAFLD patients who were then arranged into the test group and control group. Patients in the test group were treated with DHZCPs, while patients in the control group were untreated. Peripheral TH17 and Treg cells were detected by flow cytometry, and peripheral IL-17, IL-10, hs-CRP, and TNF-α expression levels were determined by enzyme-linked immunosorbent assay (ELISA) methods. The concentrations of ghrelin, leptin, and adiponectin were quantitatively examined. Results. The levels of TC, TG, ALT, and AST were declined but the level of HDL-C was increased in NAFLD patients treated with DHZCPs compared with untreated patients ( $P<0.05$ ). The ratio of Th17/Treg in NAFLD patients treated with DHZCPs was (1.52 ± 0.21), which was significantly lower than (2.39 ± 0.45) of untreated patients ( $P<0.05$ ). The levels of IL-17, hs-CRP, and TNF-α were lower, but the level of IL-10 was higher in NAFLD patients treated with DHZCPs than that in untreated patients ( $P<0.05$ ). The expression levels of ghrelin and adiponectin in NAFLD patients treated with DHZCPs were evidently higher than those in untreated patients ( $P<0.01$ ), and the expression level of leptin in NAFLD patients treated with DHZCPs was evidently lower than that in untreated patients ( $P<0.01$ ). Conclusions. Administration of DHZCPs regulates the immune function of NAFLD patients by keeping Th17/Treg balance and affecting the levels of inflammatory cytokines and adipocytokines.

Hepatoprotective Effect of Bee Bread in Metabolic Dysfunction-Associated Fatty Liver Disease (MAFLD) Rats: Impact on Oxidative Stress and Inflammation

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a pathological accumulation of hepatic lipid closely linked with many metabolic disorders, oxidative stress and inflammation. We aimed to evaluate the hepatoprotective effect of bee bread on oxidative stress and inflammatory parameters in MAFLD rats. Twenty-eight male Sprague-Dawley rats were assigned into four groups (n = 7/group): normal control (NC), high-fat diet (HFD), bee bread (HFD + Bb, HFD + 0.5 g/kg/day bee bread) and orlistat (HFD + Or, HFD + 10 mg/kg/day orlistat) groups. After 12 weeks, the HFD group demonstrated significantly higher body weight gain, serum levels of lipids (TG, TC, LDL), liver enzymes (AST, ALT, ALP) and adiponectin, liver lipids (TG, TC) and insulin resistance (HOMA-IR). Furthermore, the HFD group showed significantly decreased antioxidant enzyme activities (GPx, GST, GR, SOD, CAT) and GSH level, and increased liver oxidative stress (TBARS, NO), translocation of Nrf2 to the nucleus, Keap1 expression and inflammation (TNF-α, NF-κβ, MCP-1) together with histopathological alterations (steatosis, hepatocyte hypertrophy, inflammatory cell infiltration, collagen deposition), which indicated the presence of non-alcoholic steatohepatitis (NASH) and fibrosis. Bee bread significantly attenuated all these changes exerted by HFD feeding. In conclusion, our results suggest that bee bread might have antioxidant, anti-inflammatory, anti-steatotic and anti-fibrotic effects that are beneficial in protecting liver progression towards NASH and fibrosis.

Protective and Therapeutic Effects of Orlistat on Metabolic Syndrome and Oxidative Stress in High-Fat Diet-Induced Metabolic Dysfunction-Associated Fatty Liver Disease (MAFLD) in Rats: Role on Nrf2 Activation

Metabolic dysfunction-associated fatty liver disease (MAFLD) is an excessive buildup of liver lipids closely associated with various kinds of undesirable metabolic effects and oxidative stress. We aimed to investigate the protective and therapeutic effects of orlistat on metabolic syndrome and oxidative stress parameters in high-fat diet (HFD) induced-MAFLD rats. Twenty-four male Sprague-Dawley rats were randomly divided into four groups (n = 6/group), i.e., Normal control (N), HFD, HFD + orlistat (HFD + O) (10 mg/kg/day administered concomitantly for 12 weeks as a protective model), and obese+orlistat (OB + O) (10 mg/kg/day administered 6 weeks after induction of obesity as a therapeutic model) groups. After 12 weeks, the HFD group had significantly increased Lee obesity index, serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, total cholesterol, triglyceride, low-density lipoprotein levels, liver total cholesterol and triglyceride levels, insulin resistance and non-alcoholic steatohepatitis (NASH) together with decreased serum high-density lipoprotein level. Additionally, the HFD group also showed increased Nrf2 translocation to the nucleus with high Keap1 expression and increased liver oxidative stress parameters. Orlistat significantly improved all these alterations in HFD rats. We demonstrated that orlistat might have protective and therapeutic effects against HFD-induced MAFLD rats by its activation on Nrf2 signaling pathway, which subsequently improved metabolic syndrome and oxidative stress parameters.

Adipocytokines as Risk Factors for Development of Nonalcoholic Fatty Liver Disease in Children

BACKGROUND

Noninvasive diagnostics of nonalcoholic fatty liver disease (NAFLD), the most common cause of liver dysfunction in children, are based on imaging, biochemical tests and their compilation. The study aimed to evaluate the serological biomarkers of steatosis, inflammation and liver fibrosis to assess the risk of NAFLD in children.

METHODS

A total of 73 children were included in the prospective study; 50 of them were diagnosed with NAFLD based on ultrasound, and 23 formed a control group. Basic anthropometric parameters were measured, blood samples were taken for laboratory tests and evaluated proteins were assessed by enzyme-linked immunosorbent assay-adiponectin, tumour necrosis factor alpha, fibroblast growth factor 21, liver fatty acid-binding protein (L-FABP) and interleukin 6.

RESULTS

Statistically significant differences between the levels of two proteins were found: the adiponectin level was lower in the NAFLD group (12.24 ± 7.01 vs 16.88 ± 9.21 μg/mL, P = 0.024), and L-FABP levels were higher (21.48 ± 20.61 vs 11.74 ± 8.39 ng/mL, P = 0.031). In the group of children with body mass index (BMI)-for-age >1 standard deviation (SD), adiponectin concentration was also significantly lower (12.18 ± 6.43 μg/mL) than in the group with BMI ≤1 SD (17.29 ± 9.42 μg/mL, P = 0.015). The odds ratios and 95% confidence interval for the relation between adiponectin and NAFLD and obesity were 0.868 (0.767-0.982) and 0.838 (0.719-0.977), respectively.

CONCLUSION

Adiponectin may be useful in evaluating the risk of NAFLD and obesity in children.

Hepatic Fat in Participants With and Without Incident Diabetes in the Diabetes Prevention Program Outcome Study

CONTEXT

There is little information about fatty liver in prediabetes as it transitions to early diabetes.

OBJECTIVE

This study is aimed at evaluating the prevalence and determinants of fatty liver in the Diabetes Prevention Program (DPP).

METHODS

We measured liver fat as liver attenuation (LA) in Hounsfield units (HU) in 1876 participants at ~14 years following randomization into the DPP, which tested the effects of lifestyle or metformin interventions versus standard care to prevent diabetes. LA was compared among intervention groups and in those with versus without diabetes, and associations with baseline and follow-up measurements of anthropometric and metabolic covariates were assessed.

RESULTS

There were no differences in liver fat between treatment groups at 14 years of follow-up. Participants with diabetes had lower LA (mean ± SD: 46 ± 16 vs 51 ± 14 HU; P < 0.001) and a greater prevalence of fatty liver (LA < 40 HU) (34% vs 17%; P < 0.001). Severity of metabolic abnormalities at the time of LA evaluation was associated with lower LA categories in a graded manner and more strongly in those with diabetes. Averaged annual fasting insulin (an index of insulin resistance [OR, 95% CI 1.76, 1.41-2.20]) waist circumference (1.63, 1.17-2.26), and triglyceride (1.42, 1.13-1.78), but not glucose, were independently associated with LA < 40 HU prevalence.

CONCLUSION

Fatty liver is common in the early phases of diabetes development. The association of LA with insulin resistance, waist circumference, and triglyceride levels emphasizes the importance of these markers for hepatic steatosis in this population and that assessment of hepatic fat in early diabetes development is warranted.

Sex Differences in Nonalcoholic Fatty Liver Disease: Estrogen Influence on the Liver-Adipose Tissue Crosstalk

Significance: Nonalcoholic fatty liver disease (NAFLD) is a hepatic and systemic disorder with a complex multifactorial pathogenesis. Owing to the rising incidence of obesity and diabetes mellitus, the prevalence of NAFLD and its impact on global health care are expected to increase in the future. Differences in NAFLD exist between males and females, and among females depending on their reproductive status. Clinical and preclinical data show that females in the fertile age are more protected against NAFLD, and studies in postmenopausal women and ovariectomized animal models support a protective role for estrogens. Recent Advances: An efficient crosstalk between the liver and adipose tissue is necessary to regulate lipid and glucose metabolism, protecting the liver from steatosis and insulin resistance contributing to NALFD. New advances in the knowledge of sexual dimorphism in liver and adipose tissue are providing interesting clues about the sex differences in NAFLD pathogenesis that could inspire new therapeutic strategies. Critical Issues: Sex hormones influence key master regulators of lipid metabolism and oxidative stress in liver and adipose tissue. All these sex-biased metabolic adjustments shape the crosstalk between liver and adipose tissue, contributing to the higher protection of females to NAFLD. Future Directions: The development of novel drugs based on the protective action of estrogens, but without its feminizing or undesired side effects, might provide new therapeutic strategies for the management of NAFLD. Antioxid. Redox Signal. 35, 753-774.

The evolving obesity challenge: targeting the vagus nerve and the inflammatory reflex in the response

Obesity and the metabolic syndrome (MetS), which have reached pandemic proportions significantly increase the risk for type 2 diabetes, cardiovascular disease, and other serious conditions. Recent data with COVID-19 patients indicate that obesity also is a significant risk factor for this novel viral disease and poor outcome of associated critical illness. These findings considerably change the view of obesity as a driver of serious, but slowly-progressing chronic diseases, and emphasize the urgency to explore new therapeutic approaches. Inflammation is a recognized driver of metabolic derangements in obesity and MetS, and a core feature of COVID-19 pathobiology. Recent advances in our understanding of inflammatory regulation have highlighted the role of the nervous system and the vagus nerve-based inflammatory reflex. Current bioelectronic and pharmacological therapeutic explorations centered on the inflammatory reflex offer new approaches for conditions characterized by immune and metabolic dysregulation and for ameliorating the escalating burden of obesity, MetS, and COVID-19.

Efficacy and Safety of GLP-1 Receptor Agonists in Patients With Type 2 Diabetes Mellitus and Non-Alcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis

The prevalence of non-alcoholic fatty liver disease (NAFLD) in patients with type 2 diabetes mellitus (T2DM) is increasing and there is an urgent need for new treatment strategy to prevent progression of hepatic steatosis and fibrosis. We have performed a systematic review and meta-analysis of randomized controlled trials (RCTs) to evaluate the efficacy and safety of glucagon-like peptide-1 receptor agonists (GLP-1RAs) in the treatment of hepatic steatosis and fibrosis in patients with T2DM and NAFLD. The PubMed, Web of Science, Scopus, Embase and Cochrane Central Register of Controlled Trials databases were searched for articles that met the eligibility criteria to explore the efficacy and safety of GLP-1RAs in patients with T2DM and NAFLD. We assessed pooled data using a random/fixed-effects model according to the I² and p-values. Eight trials that included a total of 468 participants were eligible for inclusion in the review. For primary outcomes, administration of GLP-1RAs significantly decreased the content of intrahepatic adipose (IHA)[p=0.007, weight mean difference (WMD) -3.01, 95% confidence interval (CI) -4.75, -1.28], subcutaneous adipose tissue (SAT) (p<0.00001,WMD -28.53,95%CI -68.09,-26.31), and visceral adipose tissue (VAT) (p<0.0001,WMD -29.05,95%CI -42.90,-15.9). For secondary outcomes, GLP-1RAs produced a significant decrease in levels of alanine aminotransferase(ALT)(p=0.02, WMD -3.82, 95%CI -7.04, -0.60), aspartate aminotransferase (AST) (p=0.03, WMD -2.4, 95%CI -4.55,-0.25, I² = 49%), body weight (p<0.00001,WMD -3.48,95%CI -4.58,-2.37), body mass index (p<0.00001,WMD -1.07,95%CI -1.35,-0.78), circumference waist (p=0.0002,WMD -3.87, 95%CI -5.88, -1.86) fasting blood glucose (p=0.02, WMD -0.35, 95%CI -0.06, -0.05), HbA_1c (p<0.00001,WMD -0.39,95%CI -0.56,-0.22), HoMA-IR(p=0.005, WMD-1.51, 95%CI-0.87,-0.16), total cholesterol (p=0.0008, WMD -0.31, 95%CI -0.48, 0.13) and triglycerides (p=0.0008, WMD -0.27, 95%CI -0.43,-0.11) in comparison with the control regimens. The main adverse events associated with GLP-1RAs included mild-to-moderate gastrointestinal discomfort and nonsense hypoglycemia that resolved within a few weeks. GLP-1RAs were an effective treatment that improved intrahepatic visceral and subcutaneous adipose tissue, inflammatory markers, the anthropometric profiles and some metabolic indices in patients with T2DM and NAFLD, GLP-1RAs could be considered for use in these if there are no contraindications. Further studies are needed to understand the direct and indirect effects of GLP-1RAs on NAFLD and the potential mechanism via which they prevent its progression. Systematic Review Registration: PROSPERO, identifier CRD42021265806.

Abnormal metabolic processes involved in the pathogenesis of non-alcoholic fatty liver disease (Review)

Non-alcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases and can lead to liver cirrhosis or liver cancer in severe cases. In recent years, the incidence of NAFLD has increased substantially. The trend has continued to increase and has become a key point of concern for health systems. NAFLD is often associated with metabolic abnormalities caused by increased visceral obesity, including insulin resistance, diabetes mellitus, hypertension, dyslipidemia, atherosclerosis and systemic microinflammation. Therefore, the pathophysiological mechanisms of NAFLD must be clarified to develop new drug treatment strategies. Recently, researchers have conducted numerous studies on the pathogenesis of NAFLD and have identified various important regulatory factors and potential molecular mechanisms, providing new targets and a theoretical basis for the treatment of NAFLD. However, the pathogenesis of NAFLD is extremely complex and involves the interrelationship and influence of multiple organs and systems. Therefore, the condition must be explored further. In the present review, the abnormal metabolic process, including glucose, lipid, amino acid, bile acid and iron metabolism are reviewed. It was concluded that NAFLD is associated with an imbalanced metabolic network that involves glucose, lipids, amino acids, bile acids and iron, and lipid metabolism is the core metabolic process. The current study aimed to provide evidence and hypotheses for research and clinical treatment of NAFLD.

Data on Adiponectin from 2010 to 2020: Therapeutic Target and Prognostic Factor for Liver Diseases?

The review describes the role of adiponectin in liver diseases in the presence and absence of surgery reported in the literature in the last ten years. The most updated therapeutic strategies based on the regulation of adiponectin including pharmacological and surgical interventions and adiponectin knockout rodents, as well as some of the scientific controversies in this field, are described. Whether adiponectin could be a potential therapeutic target for the treatment of liver diseases and patients submitted to hepatic resection or liver transplantation are discussed. Furthermore, preclinical and clinical data on the mechanism of action of adiponectin in different liver diseases (nonalcoholic fatty disease, alcoholic liver disease, nonalcoholic steatohepatitis, liver cirrhosis and hepatocellular carcinoma) in the absence or presence of surgery are evaluated in order to establish potential targets that might be useful for the treatment of liver disease as well as in the practice of liver surgery associated with the hepatic resections of tumors and liver transplantation.

LncPRYP4-3 serves as a novel diagnostic biomarker for dissecting subtypes of metabolic associated fatty liver disease by targeting RPS4Y2

Longitudinal studies have improved current diagnostics and management of metabolic associated fatty liver disease (MAFLD) patients by liver biopsy and therapeutic intervention, yet the deficiency of biomarker spectrum for dissecting subtypes largely hinders the symptomatic treatment. We originally enriched serum from peripheral blood of 618 healthy donors (HD) and 580 MAFLD (400 NAFL, 180 NASH) patients according to multiple clinicopathological indicators. Microarray profiling and qRT-PCR were conducted to identify lncRNAs as candidate biomarkers of MAFLD. Then, we analyzed the matching score of the indicated lncRNA with CAP or MAFLD-associated pathological parameters as well. Additionally, we took advantage of interaction network together with gene expression profiling analysis to further explore the underlying target genes of the identified lncRNA. Herein, we found CAP in nearly all of the NAFL (399/400) and NASH (179/180) patients was higher than that in the HDs (611/618). The differentially expressed lncRNAs were involved in multiple metabolic or immunologic processes by regulating MAFLD-associated pathways. Of them, serum lncPRYP4-3 was identified as a novel candidate biomarker of MAFLD, which was further confirmed by correlation analysis with clinical indicators. Thereafter, we deduced PRS4Y2 was a candidate target of lncPRYP4-3 and mediated the dysfunction in NAFL and NASH patients. Serum lncPRYP4-3 served as a novel biomarker of MAFLD and helped distinguish the subtypes and benefit precise intervention therapy. Our findings also provided overwhelming new evidence for the alteration in biological processes and gene ontology in MAFLD patients.

Macrophages in the pathophysiology of NAFLD: The role of sex differences

Nonalcoholic fatty liver disease (NAFLD) is a multifactorial pathological condition, which recognizes a certain sexual dimorphism. Experimental and clinical studies provided evidence for a critical role of macrophages in NAFLD development and progression. Especially, liver-resident macrophages (also known as Kupffer cells) are likely the common final pathway of several pro-steatosic signals. A huge amount of danger-associated molecular patterns recognized by Kupffer cells is provided within the liver by lipid and glucose toxicity. Other pro-inflammatory signals come from surrounding tissues into the portal vein, directly to the liver: they come from dysfunctional adipocytes, adipose tissue macrophages and gut dysbiosis. These complex crosstalks are differently represented across sexes, as sexual hormones control many of these processes. Sexual dimorphism then modulates metabolic and inflammatory cascades driving the liver from a simple steatosis to NAFLD and beyond. Here, metabolic and inflammatory mechanisms underlying NALFD pathophysiology will be updated. A special attention will be paid to describe sex-related differences that could provide insights for patient stratification and more tailored therapeutic approaches.

NAFLD and autoimmune hepatitis: Do not judge a book by its cover

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease (almost 25% of the general population). Autoimmune hepatitis (AIH) is a relatively rare liver disease of unknown aetiology characterized by female predominance and large heterogeneity regarding epidemiology, clinical manifestations, genetics, serology and liver pathology. The potential NAFLD/AIH coincidence or an AIH diagnosis alone instead of NAFLD represent a challenge for clinicians, both in making a correct and timely diagnosis but also in the management of these diseases. The diagnosis of both diseases can be challenging as: (a) reliable laboratory tests to confidently diagnose or exclude NAFLD or AIH are missing; (b) physicians and pathologists are much more familiar with a very common disease like NAFLD so, they do not consider an alternative or additional diagnosis; (c) most NAFLD studies do not investigate the patients for all autoantibodies involved in AIH diagnosis, apply the diagnostic scoring systems for AIH or address the possibility of AIH features on liver histology and (d) the recent European and American practice guidelines for NAFLD do not mention clearly the importance of IgG determination and liver autoimmune serology according to the AIH guidelines. Patients with NAFLD/AIH coincidence have significantly more frequently hypertension, diabetes, obesity, older age, lower transaminases, bilirubin and simplified score for AIH diagnosis but no female predominance compared to AIH patients only. The true outcome of NAFLD/AIH patients is practically unknown while their management is quite problematic because official clinical practice guidelines for this condition are missing.

NAFLD and Atherosclerosis: Two Sides of the Same Dysmetabolic Coin?

The prevalence of non-alcoholic fatty liver disease (NAFLD) is strongly increasing and may put patients at increased risk for atherosclerotic cardiovascular disease (asCVD). Both disease phenotypes often co-occur, in the case of obesity, insulin resistance, diabetes mellitus type 2, and the metabolic syndrome. We explore the pathogenesis of NAFLD, the epidemiology of asCVD in NAFLD patients, shared drivers of both phenotypes, and factors caused by NAFLD that contribute to asCVD. Genetic studies support that NAFLD may drive asCVD through mixed hyperlipidemia. Next, we discuss the prospects of lifestyle improvement and pharmacological treatment of NAFLD for asCVD risk reduction. Finally, we point out that earlier identification of patients with NAFLD should be pursued by increasing awareness of the association of these two phenotypes and collaboration between the involved physicians.

First demonstration of protective effects of purified mushroom polysaccharide-peptides against fatty liver injury and the mechanisms involved

Fatty liver (FLD) disease is a consequence of metabolic syndrome, which is a health problem worldwide with a phenomenal rise in prevalence. In this study, two hepatoprotective polysaccharide-peptides were extracted from the mushroom Auricularia polytricha followed by chromatographic fractionation of the extract on the ion exchanger DEAE-cellulose and gel filtration on Sephadex-200 to yield two purified fractions: APPI and APPII. The monosaccharide compositions, FT-IR, N-terminal sequences, internal peptide sequences and molecular weights of the two fractions were determined. Furthermore, their hepatoprotective effect on human hepatoma HepG2 cells in vitro and in an animal model of fatty liver disease was evidenced by the findings that APPI and APPII diminished lipid deposit in cells, blood and the liver, increased cellular antioxidant activity and viability, and protected the liver against injury. The mechanistic study revealed that APPI and APPII activated the adiponectin pathway, up-regulated expression of genes controlling free fatty acid (FFA) oxidation, such as AMPK, CPTl, ACOX1 and PPARα genes, enhanced lipid metabolism, preserved hepatic function, promoted the antioxidant defense system and reduced lipid peroxidation. Hence the bioactive compounds of A. polytricha could serve as therapeutic agents in the food and pharmaceutical industries.

Organokines in disease

Studies have linked obesity, metabolic syndrome, type 2 diabetes, cardiovascular disease (CVD), nonalcoholic fatty liver disease (NAFLD) and dementia. Their relationship to the incidence and progression of these disease states suggests an interconnected pathogenesis involving chronic low-grade inflammation and oxidative stress. Metabolic syndrome represents comorbidities of central obesity, insulin resistance, dyslipidemia, hypertension and hyperglycemia associated with increased risk of type 2 diabetes, NAFLD, atherosclerotic CVD and neurodegenerative disease. As the socioeconomic burden for these diseases has grown signficantly with an increasing elderly population, new and alternative pharmacologic solutions for these cardiometabolic diseases are required. Adipose tissue, skeletal muscle and liver are central endocrine organs that regulate inflammation, energy and metabolic homeostasis, and the neuroendocrine axis through synthesis and secretion of adipokines, myokines, and hepatokines, respectively. These organokines affect each other and communicate through various endocrine, paracrine and autocrine pathways. The ultimate goal of this review is to provide a comprehensive understanding of organ crosstalk. This will include the roles of novel organokines in normal physiologic regulation and their pathophysiological effect in obesity, metabolic syndrome, type 2 diabetes, CVD, NAFLD and neurodegenerative disorders.

Comparative study of overweight and obese patients with nonalcoholic fatty liver disease

BACKGROUND AND AIMS

non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disorder in the western world. Although NAFLD prevalence is higher in patients with a BMI > 25 kg /m2, it is unclear if there are differences between overweight and obese patients. The associated biochemical, dietary and genetic parameters were compared between overweight and obese patients with NAFLD.

METHODS

patients with biopsy-proven NAFLD (n = 203) were enrolled in a cross-sectional study. The MEDAS questionnaire was used to assess adherence to the Mediterranean diet. Biochemical, anthropometrical parameters and the I148M variant (rs738409) of the PNPLA3 gene and rs180069 of the TNF-α gene were evaluated.

RESULTS

overweight patients had higher serum adiponectin levels (22.5 ± 21.9 vs 11.2 ± 18.1 ng/ml; p < 0.05) and lower resistin (3.3 ± 1.7 vs 8.1 ± 8 ng/ml; p < 0.001) and leptin concentrations (22.9 ± 21.9 vs 55.8 ± 45 ng/ml; p < 0.001) than obese patients. Non-alcoholic steatohepatitis (NASH) was more frequent in the obese group (59.3% vs 41.3%; p = 0.02). The multivariate analysis showed adherence to the Mediterranean diet to be an independent protective factor for NASH and liver fibrosis in overweight patients (OR 0.7, 95% CI 0.5-0.8).

CONCLUSIONS

NASH was more prevalent in obese patients than in overweight subjects. HOMA-IR and adherence to the Mediterranean diet provided protection against fibrosis in overweight patients. Adherence to the Mediterranean diet was the only independent factor associated with NASH in these patients.

The role of macrophages in nonalcoholic fatty liver disease and nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) and its inflammatory and often progressive subtype nonalcoholic steatohepatitis (NASH) are becoming the leading cause of liver-related morbidity and mortality worldwide, and a primary indication for liver transplantation. The pathophysiology of NASH is multifactorial and not yet completely understood; however, innate immunity is a major contributing factor in which liver-resident macrophages (Kupffer cells) and recruited macrophages play a central part in disease progression. In this Review, we assess the evidence for macrophage involvement in the development of steatosis, inflammation and fibrosis in NASH. In this process, not only the polarization of liver macrophages towards a pro-inflammatory phenotype is important, but adipose tissue macrophages, especially in the visceral compartment, also contribute to disease severity and insulin resistance. Macrophage activation is mediated by factors such as endotoxins and translocated bacteria owing to increased intestinal permeability, factors released from damaged or lipoapoptotic hepatocytes, as well as alterations in gut microbiota and defined nutritional components, including certain free fatty acids, cholesterol and their metabolites. Reflecting the important role of macrophages in NASH, we also review studies investigating drugs that target macrophage recruitment to the liver, macrophage polarization and their inflammatory effects as potential treatment options for patients with NASH.

BuShenKangShuai Tablet Alleviates Hepatic Steatosis via Improving Liver Adiponectin Resistance in ApoE-/- Mice

BuShenKangShuai tablet (BSKS) is a Chinese herbal compound, which has been used to treat nonalcoholic fatty liver disease and cardiovascular diseases in clinic for over four decades. This study intends to explore whether BSKS administration can alleviates hepatic steatosis via improving liver adiponectin resistance in ApoE^−/− mice. ApoE^−/− mice were fed with western-type diet for 6 weeks and then were administrated with BSKS or atorvastatin for 6 weeks by gavage, and then blood and liver were collected for analysis. The results showed that BSKS attenuated hepatic steatosis, decreased blood lipids, and increased the serum level of adiponectin. We also found that adiponectin resistance in the liver was improved by BSKS, while the expression of TLR4 and NF-κB p65 was inhibited, followed by the suppression of proinflammatory mediators of TNF-α. Our data provided evidence that BSKS was able to alleviate hepatic steatosis in vivo. The underlying mechanism of BSKS was focused on improving liver adiponectin resistance, thereby regulating dyslipidemia and inhibiting inflammatory signaling pathway.

Interplay between early-life malnutrition, epigenetic modulation of the immune function and liver diseases

Early-life nutrition plays a critical role in fetal growth and development. Food intake absence and excess are the two main types of energy malnutrition that predispose to the appearance of diseases in adulthood, according to the hypothesis of 'developmental origins of health and disease'. Epidemiological data have shown an association between early-life malnutrition and the metabolic syndrome in later life. Evidence has also demonstrated that nutrition during this period of life can affect the development of the immune system through epigenetic mechanisms. Thus, epigenetics has an essential role in the complex interplay between environmental factors and genetics. Altogether, this leads to the inflammatory response that is commonly seen in non-alcoholic fatty liver disease (NAFLD), the hepatic manifestation of the metabolic syndrome. In conjunction, DNA methylation, covalent modification of histones and the expression of non-coding RNA are the epigenetic phenomena that affect inflammatory processes in the context of NAFLD. Here, we highlight current understanding of the mechanisms underlying developmental programming of NAFLD linked to epigenetic modulation of the immune system and environmental factors, such as malnutrition.

Decreased serum neuregulin 4 levels associated with non-alcoholic fatty liver disease in children with obesity

Neuregulin 4 (Nrg4), a newly identified adipokine secreted by brown adipose tissue, is hypothesised to play a crucial role in metabolism. The present study aimed to evaluate the association between serum Nrg4 levels and non-alcoholic fatty liver disease (NAFLD) in children with obesity in China. A total of 123 children with obesity were included in this study. Anthropometric and biochemical parameters were measured in all subjects. NAFLD was diagnosed using ultrasonography. The serum levels of Nrg4, leptin and adiponectin were measured by enzyme-linked immunosorbent assay. NAFLD was identified in 58 children with obesity (47.2%). Serum Nrg4 levels were significantly lower in the NAFLD group (2.24 [1.20, 3.22] ng/mL) than in the control group (5.50 [2.45, 10.85] ng/mL) (p < 0.001). Serum Nrg4 levels were negatively correlated with most of the anthropometric and biochemical parameters (p < 0.05) but were positively correlated with high-density lipoprotein cholesterol (p < 0.05). In multiple stepwise regression analyses, serum Nrg4 levels were independently related with WHtR (β = -2.009, p = 0.048) and homeostasis model assessment of insulin resistance (β = -0.524, p = 0.005). Furthermore, a multivariable logistic regression analysis of NAFLD prediction by Nrg4 revealed an odds ratio of 0.129 (95% confidence interval: 0.028-0.587, p < 0.01). The receiver operating characteristic curve analysis of the diagnostic value of using serum Nrg4 levels to differentiate NAFLD in children with obesity showed that the area under the curve was 0.723; the cutoff for serum Nrg4 levels to have diagnostic value for predicting NAFLD in children with obesity was 3.39 ng/mL. Elevated Nrg4 is associated with a decreased risk of NAFLD in children with obesity.

Adiponectin homolog novel osmotin protects obesity/diabetes-induced NAFLD by upregulating AdipoRs/PPARα signaling in ob/ob and db/db transgenic mouse models

BACKGROUND

In metabolic disorders, adiponectin and adiponectin receptors (AdipoR1/R2) signaling has a key role in improving nonalcoholic fatty liver disease (NAFLD) in obesity-associated diabetes.

OBJECTIVE

To the best of our knowledge, here, we reported for the first time the underlying mechanistic therapeutic efficacy of the novel osmotin, a homolog of mammalian adiponectin, against NAFLD in leptin-deficient ob/ob and db/db mice.

METHODS

The ob/ob and db/db mice were treated with osmotin at a dose of 5 μg/g three times a week for two weeks. To co-relate the in vivo results we used the human liver carcinoma HepG2 cells, subjected to knockdown with small siRNAs of AdipoR1/R2 and PPARα genes and treated with osmotin and palmitic acid (P.A.). MTT assay, Western blotting, immunohistofluorescence assays, and plasma biochemical analyses were applied.

RESULTS

Osmotin stimulated AdipoR1/R2 and its downstream APPL1/PPAR-α/AMPK/SIRT1 pathways in ob/ob and db/db mice, and HepG2 cells exposed to P.A. Mechanistically, we confirmed that knockdown of AdipoR1/R2 and PPARα by their respective siRNAs abolished the osmotin activity in HepG2 cells exposed to P.A. Overall, the in vivo and in vitro results suggested that osmotin protected against NAFLD through activation of AdipoR1/R2 and its downstream APPL1/PPAR-α/AMPK/SIRT1 pathways as shown by the reduced body weight, blood glucose level and glycated hemoglobin, improved glucose tolerance, attenuated insulin resistance and hepatic glucogenesis, regulated serum lipid parameters, and increased fatty acid oxidation and mitochondrial functions.

CONCLUSION

Our findings strongly suggest that novel osmotin might be a potential novel therapeutic tool against obesity/diabetes-induced NAFLD and other metabolic disorders.

Blood-based novel biomarkers for nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease has become a social health challenge of global concern. The term nonalcoholic steatohepatitis (NASH) is a more severe condition than simple steatosis and distinguishing NASH from nonalcoholic fatty liver disease is particularly important. Liver biopsy remains a gold standard in diagnosing NASH. Meanwhile, radiological techniques such as ultrasonography and MRI are also applied widely. However, the invasive and expensive examination is not suitable for screening, and there is a great need for reliable and appropriate biomarkers to screen patients for NASH. Based on the current studies of blood-based novel biomarkers, we attempt to summarize the latest findings on biomarkers for NASH, including blood biomarkers encompassing proteins, lipids and miRNAs; the correlation between extracellular vesicles and NASH; and treatment strategies for NASH.

Exercise restores muscle stem cell mobilization, regenerative capacity and muscle metabolic alterations via adiponectin/AdipoR1 activation in SAMP10 mice

BACKGROUND

Exercise train (ET) stimulates muscle response in pathological conditions, including aging. The molecular mechanisms by which exercise improves impaired adiponectin/adiponectin receptor 1 (AdipoR1)-related muscle actions associated with aging are poorly understood. Here we observed that in a senescence-accelerated mouse prone 10 (SAMP10) model, long-term ET modulated muscle-regenerative actions.

METHODS

25-week-old male SAMP10 mice were randomly assigned to the control and the ET (45 min/time, 3/week) groups for 4 months. Mice that were maintained in a sedentary condition served controls.

RESULTS

ET ameliorated aging-related muscle changes in microstructure, mitochondria, and performance. The amounts of proteins or mRNAs for p-AMPKα, p-Akt, p-ERK1/2, p-mTOR, Bcl-XL, p-FoxO3, peroxisome proliferators-activated receptor-γ coactivator, adiponectin receptor1 (adpoR1), and cytochrome c oxidase-IV, and the numbers of CD34⁺ /integrin-α₇⁺ muscle stem cells (MuSCs) and proliferating cells in the muscles and bone-marrow were enhanced by ET, whereas the levels of p-GSK-3α and gp91phox proteins and apoptotic cells were reduced by ET. The ET also resulted in increased levels of plasma adiponectin and the numbers of bone-marrow (BM)-derived circulating CD34⁺ /integrin-α₇⁺ MuSCs and their functions. Integrin-α₇⁺ MuSCs of exercised mice had improved changes of those beneficial molecules. These ET-mediated aged muscle benefits were diminished by adiponectin and AdipoR1 blocking as well as AMPK inhibition. Finally, recombinant mouse adiponectin enhanced AMPK and mTOR phosphorylations in BM-derived integrin-α₇⁺ cells.

CONCLUSIONS

These findings suggest that ET can improve aging-related impairments of BM-derived MuSC regenerative capacity and muscle metabolic alterations via an AMPK-dependent mechanism that is mediated by an adiponectin/AdipoR1 axis in SAMP10 mice.

The Effects of Metabolic Surgery on Fatty Liver Disease and Nonalcoholic Steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) is an under-recognized but increasingly important manifestation of the metabolic syndrome. Bariatric surgery, both through direct weight loss and more indirect effects on insulin resistance and improvements in inflammatory proteins, can have a profound effect on NAFLD, resulting in improvement or resolution of even high-grade liver disease.

The role of ADIPOQ methylation in curcumin-administrated experimental nonalcoholic fatty liver disease

OBJECTIVE

To investigate the role of adiponectin precursor (ADIPOQ) DNA methylation in the pathogenesis of nonalcoholic fatty liver disease (NAFLD) and the effect of curcumin on the development of NAFLD using rat models.

METHODS

Male Sprague-Dawley rats were divided into the control, NAFLD and curcumin-treated groups. The genetic and epigenetic features of each rat were measured and recorded. Real-time polymerase chain reaction (PCR), Western blot and bisulfite sequencing PCR (BSP) were used to quantify the ADIPOQ mRNA and protein expressions, and DNA methylation status, respectively.

RESULTS

Serum levels of alanine aminotransferase (ALT), triglyceride (TG), total cholesterol (TC) and fasting blood glucose in the NAFLD group were significantly increased compared with the control group. The genetic and epigenetic features were reversed after curcumin treatment. The ADIPOQ mRNA and protein expressions in the livers of the NAFLD rats was lower compared with the control and the curcumin-treated groups. ADIPOQ methylation rate in the NAFLD group was significantly higher than in the control group, which was declined slightly following curcumin treatment. A negative correlation was found between the degrees of DNA methylation and ADIPOQ mRNA expression. ALT, TC, TG and homeostatic model assessment insulin resistance index had a positive correlation with ADIPOQ DNA methylation, showing that curcumin might affect the gene expression involved in lipid and glucose metabolism by influencing ADIPOQ DNA methylation modifications, which contributed to alleviation of NAFLD.

CONCLUSION

Altering the DNA methylation of ADIPOQ is one of the mechanisms by which curcumin executes its hepatoprotective function in NAFLD.

The Correlation Between Serum Adipokines and Liver Cell Damage in Non-Alcoholic Fatty Liver Disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a common cause of chronic hepatitis, which can lead to cirrhosis and hepatocellular carcinoma.

OBJECTIVES

The aim of the study was to evaluate the correlation between serum adipocytokines and the histologic findings of the liver in patients with non-alcoholic fatty liver disease (NAFLD).

PATIENTS AND METHODS

This case-control study was performed on those with persistent elevated liver enzymes and with evidence of fatty liver in ultrasonography. After exclusion of patients with other etiologies causing abnormal liver function tests, the resulting patients underwent liver biopsies. NAFLD was diagnosed based on liver histology according to the Brunt scoring system.

RESULTS

Waist circumferences and levels of blood glucose (after fasting), insulin, triglycerides, alanine aminotransferases (ALT), and aspartate aminotransferases (AST) were higher in patients with NAFLD than in those in the control group. ALT, AST, and gamma glutamine transferase (GGT) levels were lower in patients with liver steatosis of a grade of less than 33% than those with higher degrees of steatosis. Serum low-density lipoprotein (LDL), cholesterol, and hepcidin levels were significantly higher in those with lobular inflammation of grade 0 - 1 than in those with inflammation of grade 2 - 3 (Brunt score). Meanwhile, AST was significantly lower in those with lobular inflammation of grade 1 than in those with grade 2-3. Hepcidin and resistin levels were significantly higher in patients with moderate to severe fibrosis than in those with mild fibrosis.

CONCLUSIONS

It seems that surrogate liver function tests and adipocytokine levels were correlated with the histologic findings of the liver.

Metabolic phenotype and adipose and liver features in a high-fat Western diet-induced mouse model of obesity-linked NAFLD

nonalcoholic fatty liver disease (NAFLD), an obesity and insulin resistance associated clinical condition - ranges from simple steatosis to nonalcoholic steatohepatitis. To model the human condition, a high-fat Western diet that includes liquid sugar consumption has been used in mice. Even though liver pathophysiology has been well characterized in the model, little is known about the metabolic phenotype (e.g., energy expenditure, activity, or food intake). Furthermore, whether the consumption of liquid sugar exacerbates the development of glucose intolerance, insulin resistance, and adipose tissue dysfunction in the model is currently in question. In our study, a high-fat Western diet (HFWD) with liquid sugar [fructose and sucrose (F/S)] induced acute hyperphagia above that observed in HFWD-fed mice, yet without changes in energy expenditure. Liquid sugar (F/S) exacerbated HFWD-induced glucose intolerance and insulin resistance and impaired the storage capacity of epididymal white adipose tissue (eWAT). Hepatic TG, plasma alanine aminotransferase, and normalized liver weight were significantly increased only in HFWD+F/S-fed mice. HFWD+F/S also resulted in increased hepatic fibrosis and elevated collagen 1a2, collagen 3a1, and TGFβ gene expression. Furthermore, HWFD+F/S-fed mice developed more profound eWAT inflammation characterized by adipocyte hypertrophy, macrophage infiltration, a dramatic increase in crown-like structures, and upregulated proinflammatory gene expression. An early hypoxia response in the eWAT led to reduced vascularization and increased fibrosis gene expression in the HFWD+F/S-fed mice. Our results demonstrate that sugary water consumption induces acute hyperphagia, limits adipose tissue expansion, and exacerbates glucose intolerance and insulin resistance, which are associated with NAFLD progression.

Glycosyltransferases and non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the most common form of chronic liver disease and its incidence is increasing worldwide. However, the underlying mechanisms leading to the development of NAFLD are still not fully understood. Glycosyltransferases (GTs) are a diverse class of enzymes involved in catalyzing the transfer of one or multiple sugar residues to a wide range of acceptor molecules. GTs mediate a wide range of functions from structure and storage to signaling, and play a key role in many fundamental biological processes. Therefore, it is anticipated that GTs have a role in the pathogenesis of NAFLD. In this article, we present an overview of the basic information on NAFLD, particularly GTs and glycosylation modification of certain molecules and their association with NAFLD pathogenesis. In addition, the effects and mechanisms of some GTs in the development of NAFLD are summarized.

Characteristics of resistin in rheumatoid arthritis angiogenesis

Adipokines have been reported to be involved in the regulation of various physiological processes, including the immune response. Rheumatoid arthritis (RA) is an example of a systemic immune disease that causes chronic inflammation of the synovium and bone destruction in the joint. Recent therapeutic strategies based on the understanding of the role of cytokines and cellular mechanisms in RA have improved our understanding of angiogenesis. On the other hand, endogenous endothelial progenitor cells, which are a population isolated from peripheral blood monocytes have recently been identified as a homing target for pro-angiogeneic factor and vessel formation. In this review, we summarize the effects of common adipokines, such as adiponectin, leptin and resistin in RA pathogenesis and discuss other potential mechanisms of relevance for the therapeutic treatment of RA.

Prediction of Nonalcoholic Fatty Liver Disease Via a Novel Panel of Serum Adipokines

Considering limitations of liver biopsy for diagnosis of nonalcoholic liver disease (NAFLD), biomarkers' panels were proposed. The aims of this study were to establish models based on serum adipokines for discriminating NAFLD from healthy individuals and nonalcoholic steatohepatitis (NASH) from simple steatosis.This case-control study was conducted in patients with persistent elevated serum aminotransferase levels and fatty liver on ultrasound. Individuals with evidence of alcohol consumption, hepatotoxic medication, viral hepatitis, and known liver disease were excluded. Liver biopsy was performed in the remaining patients to distinguish NAFLD/NASH. Histologic findings were interpreted using "nonalcoholic fatty liver activity score." Control group consisted of healthy volunteers with normal physical examination, liver function tests, and liver ultrasound. Binary logistic regression analysis was applied to ascertain the effects of independent variables on the likelihood that participants have NAFLD/NASH.Decreased serum adiponectin and elevated serum visfatin, IL-6, TNF-a were associated with an increased likelihood of exhibiting NAFLD. NAFLD discriminant score was developed as the following: [(-0.298 × adiponectin) + (0.022 × TNF-a) + (1.021 × Log visfatin) + (0.709 × Log IL-6) + 1.154]. In NAFLD discriminant score, 86.4% of original grouped cases were correctly classified. Discriminant score threshold value of (-0.29) yielded a sensitivity and specificity of 91% and 83% respectively, for discriminating NAFLD from healthy controls. Decreased serum adiponectin and elevated serum visfatin, IL-8, TNF-a were correlated with an increased probability of NASH. NASH discriminant score was proposed as the following: [(-0.091 × adiponectin) + (0.044 × TNF-a) + (1.017 × Log visfatin) + (0.028 × Log IL-8) - 1.787] In NASH model, 84% of original cases were correctly classified. Discriminant score threshold value of (-0.22) yielded a sensitivity and specificity of 90% and 66% respectively, for separating NASH from simple steatosis.New discriminant scores were introduced for differentiating NAFLD/NASH patients with a high accuracy. If verified by future studies, application of suggested models for screening of NAFLD/NASH seems reasonable.

Adiponectin Induces Oncostatin M Expression in Osteoblasts through the PI3K/Akt Signaling Pathway

Rheumatoid arthritis (RA), a common autoimmune disorder, is associated with a chronic inflammatory response and unbalanced bone metabolism within the articular microenvironment. Adiponectin, an adipokine secreted by adipocytes, is involved in multiple functions, including lipid metabolism and pro-inflammatory activity. However, the mechanism of adiponectin performance within arthritic inflammation remains unclear. In this study, we observed the effect of adiponectin on the expression of oncostatin M (OSM), a pro-inflammatory cytokine, in human osteoblastic cells. Pretreatment of cells with inhibitors of phosphatidylinositol 3-kinase (PI3K), Akt, and nuclear factor (NF)-κB reduced the adiponectin-induced OSM expression in osteoblasts. Stimulation of the cells with adiponectin increased phosphorylation of PI3K, Akt, and p65. Adiponectin treatment of osteoblasts increased OSM-luciferase activity and p65 binding to NF-κB on the OSM promoter. Our results indicate that adiponectin increased OSM expression via the PI3K, Akt, and NF-κB signaling pathways in osteoblastic cells, suggesting that adiponectin is a novel target for arthritis treatment.

The association of circulating levels of complement-C1q TNF-related protein 5 (CTRP5) with nonalcoholic fatty liver disease and type 2 diabetes: a case-control study

BACKGROUND

It is well-established that nonalcoholic fatty liver disease (NAFLD) is associated with type 2 diabetes mellitus (T2DM). Complement-C1q TNF-related protein 5 (CTRP5) is a novel adipokine involved in the regulation of lipid and glucose metabolism. We aimed to assess plasma levels of CTRP5 in patients with NAFLD (n = 22), T2DM (n = 22) and NAFLD with T2DM (NAFLD + T2DM) (n = 22) in comparison with healthy subjects (n = 21) and also to study the association between CTRP5 levels and NAFLD and diabetes-related parameters.

METHODS

All subjects underwent anthropometric assessment, biochemical evaluation and liver stiffness (LS) measurement. Insulin resistance (IR) was determined by the homeostasis model assessment (HOMA). Plasma CTRP5 levels were measured by enzyme-linked immunosorbent assay.

RESULTS

We found significantly lower plasma levels of CTRP5 in patients with NAFLD + T2DM, NAFLD and T2DM (122.52 ± 1.92, 124.7 ± 1.82 and 118.31 ± 1.99 ng/ml, respectively) in comparison with controls (164.96 ± 2.95 ng/ml). In the whole study population, there was a significant negative correlations between CTRP5 and body mass index (r = -0.337; p = 0.002), fasting blood glucose (FBG) (r = -0.488; p < 0.001), triglyceride (TG) (r = -0.245; p = 0.031), HOMA-IR (r = -0.492; p < 0.001), insulin(r = -0.338; p = 0.002), LS (r = -0.544; p < 0.001), alanine aminotransferase (ALT) (r = -0.251; p = 0.027), waist-to-hip ratio (WHR) (r = -0.352; p = 0.002) and waist circumference (WC) (r = -0.357; p = 0.001). After adjustment for BMI, decrease in circulating levels of CTRP5 remained as a significant risk factor for NAFLD, T2DM and NAFLD + T2DM. The receiver operating characteristic (ROC) curves of circulating CTRP5 in predicting NAFLD and T2DM demonstrated an area under the curve (AUC) of 0.763 in T2DM, and 0.659 in NAFLD + T2DM.

CONCLUSIONS

It appears that the decreased levels of CTRP5 contribute to the increased risk of T2DM and NAFLD.

Oily fish, coffee and walnuts: Dietary treatment for nonalcoholic fatty liver disease

Rates of non-alcoholic fatty liver disease (NAFLD) are increasing worldwide in tandem with the metabolic syndrome, with the progressive form of disease, non-alcoholic steatohepatitis (NASH) likely to become the most common cause of end stage liver disease in the not too distant future. Lifestyle modification and weight loss remain the main focus of management in NAFLD and NASH, however, there has been growing interest in the benefit of specific foods and dietary components on disease progression, with some foods showing protective properties. This article provides an overview of the foods that show the most promise and their potential benefits in NAFLD/NASH, specifically; oily fish/ fish oil, coffee, nuts, tea, red wine, avocado and olive oil. Furthermore, it summarises results from animal and human trials and highlights potential areas for future research.

The Riddle of Nonalcoholic Fatty Liver Disease: Progression From Nonalcoholic Fatty Liver to Nonalcoholic Steatohepatitis

Nonalcoholic fatty liver (NAFL) is an emerging global epidemic which progresses to nonalcoholic steatohepatitis (NASH) and cirrhosis in a subset of subjects. Various reviews have focused on the etiology, epidemiology, pathogenesis and treatment of NAFLD. This review highlights specifically the triggers implicated in disease progression from NAFL to NASH. The integrating role of genes, dietary factors, innate immunity, cytokines and gut microbiome have been discussed.

Lactobacillus rhamnosus LA68 and Lactobacillus plantarum WCFS1 differently influence metabolic and immunological parameters in high fat diet-induced hypercholesterolemia and hepatic steatosis

TwoLactobacillusstrains were evaluated for their effects on high fat diet induced pathology in mice.

Adiponectin polymorphisms and non-alcoholic fatty liver disease risk: a meta-analysis

BACKGROUND AND AIM

The adiponectin polymorphism has been implicated in susceptibility to non-alcoholic fatty liver disease (NAFLD), but the results remain inconclusive. The aim of this meta-analysis is to investigate the association between adiponectin polymorphisms and NAFLD risk.

METHODS

All eligible case-control studies published up to September 2013 were identified by searching PubMed, Web of Science, and CNKI. Effect sizes of odds ratio (OR) and 95% confidence interval (95% CI) were calculated by using a fixed- or random-effect model.

RESULTS

A total of 10 case-control studies were included; of those, there were nine studies (1223 cases and 1580 controls) for +45T>G polymorphism, seven studies (876 cases and 989 controls) for +276G>T polymorphism, and three studies (299 cases and 383 controls) for -11337C>G polymorphism. Overall, a significantly increased risk was found for +45T>G and -11377C>G polymorphism (+45T>G: OR = 1.45, 95% CI: 1.06-2.00 for recessive model, OR = 1.48, 95% CI: 1.07-2.06 for GG vs TT; -11377C>G: OR = 1.52, 95% CI: 1.10-2.09 for dominant model, OR = 3.88, 95% CI: 1.29-11.68 for GG vs CC), while for +276G>T polymorphism, we found a significantly decreased risk between them (OR = 0.65, 95% CI: 0.45-0.94 for recessive model, OR = 0.58, 95% CI: 0.40-0.84 for TT vs GG). In subgroup analysis by ethnicity, significant association was detected among Asians for +276G>T polymorphism, but not for +45T>G polymorphism. Besides, none of the three adiponectin polymorphisms was associated with the serum adiponectin levels.

CONCLUSION

This meta-analysis suggests that adiponectin +45T>G and -11377C>G polymorphisms might be a risk factor for NAFLD, while +276G>T polymorphism may be a protective factor for NAFLD among Asians.

Role of innate immune response in non-alcoholic Fatty liver disease: metabolic complications and therapeutic tools

Non-alcoholic fatty liver disease (NAFLD) is currently the most common liver disease worldwide, both in adults and children. It is characterized by an aberrant lipid storage in hepatocytes, named hepatic steatosis. Simple steatosis remains a benign process in most affected patients, while some of them develop superimposed necroinflammatory activity with a non-specific inflammatory infiltrate and a progression to non-alcoholic steatohepatitis with or without fibrosis. Deep similarity and interconnections between innate immune cells and those of liver parenchyma have been highlighted and showed to play a key role in the development of chronic liver disease. The liver can be considered as an “immune organ” because it hosts non-lymphoid cells, such as macrophage Kupffer cells, stellate and dendritic cells, and lymphoid cells. Many of these cells are components of the classic innate immune system, enabling the liver to play a major role in response to pathogens. Although the liver provides a “tolerogenic” environment, aberrant activation of innate immune signaling may trigger “harmful” inflammation that contributes to tissue injury, fibrosis, and carcinogenesis. Pathogen recognition receptors, such as toll-like receptors and nucleotide oligomerization domain-like receptors, are responsible for the recognition of immunogenic signals, and represent the major conduit for sensing hepatic and non-hepatic noxious stimuli. A pivotal role in liver inflammation is also played by cytokines, which can initiate or have a part in immune response, triggering hepatic intracellular signaling pathways. The sum of inflammatory signals and deranged substrate handling induce most of the metabolic alteration traits: insulin resistance, obesity, diabetes, hyperlipidemia, and their compounded combined effects. In this review, we discuss the relevant role of innate immune cell activation in relation to NAFLD, the metabolic complications associated to this pathology, and the possible pharmacological tools.

Adiponectin as a routine clinical biomarker

Adiponectin is a protein synthesized and secreted predominantly by adipocytes into the peripheral blood. However, circulating adiponectin level is inversely related with body weight, especially visceral fat accumulation. The mechanism of this paradoxical relation remains obscure. Low circulating adiponectin concentrations (hypoadiponectinemia; <4 μg/mL) are associated with a variety of diseases, including dysmetabolism (type 2 diabetes, insulin resistance, hypertension, dyslipidemia, metabolic syndrome, hyperuricemia), atherosclerosis (coronary artery disease, stroke, peripheral artery disease), sleep apnea, non-alcoholic fatty liver disease, gastritis and gastro-esophageal reflux disease, inflammatory bowel diseases, pancreatitis, osteoporosis, and cancer (endometrial cancer, postmenopausal breast cancer, leukemia, colon cancer, gastric cancer, prostate cancer). On the other hand, hyperadiponectinemia is associated with cardiac, renal and pulmonary diseases. This review article focuses on the significance of adiponectin as a clinical biomarker of obesity-related diseases. Routine measurement of adiponectin in patients with lifestyle-related diseases is highly recommended.