Nonalcoholic fatty liver disease - current status and future directions

Effect of Dietary Intervention, with or without Cointerventions, on Inflammatory Markers in Patients with Nonalcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis

Nonalcoholic fatty liver disease (NAFLD) encompasses a spectrum of disease from simple steatosis to nonalcoholic steatohepatitis, with inflammatory cytokines and adipokines identified as drivers of disease progression. Poor dietary patterns are known to promote an inflammatory milieu, although the effects of specific diets remain largely unknown. This review aimed to gather and summarize new and existing evidence on the effect of dietary intervention on inflammatory markers in patients with NAFLD. The electronic databases MEDLINE, EMBASE, CINAHL, and Cochrane were searched for clinical trials which investigated outcomes of inflammatory cytokines and adipokines. Eligible studies included adults >18 y with NAFLD, which compared a dietary intervention with an alternative diet or control (no intervention) group or were accompanied by supplementation or other lifestyle interventions. Outcomes for inflammatory markers were grouped and pooled for meta-analysis where heterogeneity was allowed. Methodological quality and risk of bias were assessed using the Academy of Nutrition and Dietetics Criteria. Overall, 44 studies with a total of 2579 participants were included. Meta-analyses indicated intervention with an isocaloric diet plus supplement was more effective in reducing C-reactive protein (CRP) [standard mean difference (SMD): 0.44; 95% CI: 0.20, 0.68; P = 0.0003] and tumor necrosis factor-alpha (TNF-α) (SMD: 0.74; 95% CI: 0.02, 1.46; P = 0.03) than an isocaloric diet alone. No significant weighting was shown between a hypocaloric diet with or without supplementation for CRP (SMD: 0.30; 95% CI: -0.84, 1.44; P = 0.60) and TNF-α (SMD: 0.01; 95% CI: -0.43, 0.45; P = 0.97). In conclusion, hypocaloric and energy-restricted diets alone or with supplementation, and isocaloric diets with supplementation were shown to be most effective in improving the inflammatory profile of patients with NAFLD. To better determine the effectiveness of dietary intervention alone on a NAFLD population, further investigations of longer durations, with larger sample sizes are required.

Multi-Channel Metabolomics Analysis Identifies Novel Metabolite Biomarkers for the Early Detection of Fatty Liver Disease in Dairy Cows

Fatty liver disease, a type of metabolic disorder, frequently occurs in dairy cows during the parturition period, causing a high culling rate and, therefore, considerable economic losses in the dairy industry owing to the lack of effective diagnostic methods. Here, metabolite biomarkers were identified and validated for the diagnosis of metabolic disorders. A total of 58 participant cows, including severe fatty liver disease and normal control groups, in the discovery set (liver biopsy tested, n = 18), test set (suspected, n = 20) and verification set (liver biopsy tested, n = 20), were strictly recruited and a sample collected for their feces, urine, and serum. Non-targeted GC-MS-based metabolomics methods were used to characterize the metabolite profiles and to screen in the discovery set. Eventually, ten novel biomarkers involved in bile acid, amino acid, and fatty acid were identified and validated in the test set. Each of them had a higher diagnostic ability than the traditional serum biochemical indicators, with an average area under the receiver operating characteristic curve of 0.830 ± 0.0439 (n = 10) versus 0.377 ± 0.182 (n = 9). Especially, combined biomarker panels via different metabolic pipelines had much better diagnostic sensitivity and specificity than every single biomarker, suggesting their powerful utilization potentiality for the early detection of fatty liver disease. Intriguingly, the serum biomarkers were confirmed perfectly in the verification set. Moreover, common biological pathways were found to be underlying the pathogenesis of fatty liver syndrome in cattle via different metabolic pipelines. These newly-discovered and non-invasive metabolic biomarkers are meaningful in reducing the high culling rate of cows and, therefore, benefit the sustainable development of the dairy industry.

Non-Alcoholic Fatty Liver Disease and Extrahepatic Cancers: A Wolf in Sheep’s Clothing?

Non-alcoholic fatty liver disease (NAFLD) is now considered the main driver and leading cause of chronic liver disease globally. The umbrella term NAFLD describes a range of liver conditions closely related to insulin resistance, metabolic syndrome, diabetes mellitus, obesity, and dyslipidemia. At the same time, several malignancies, including hepatocellular carcinoma and colorectal cancer, are considered to be common causes of death among patients with NAFLD. At first, our review herein aims to investigate the role of NAFLD in developing colorectal neoplasms and adenomatous polyps based on the current literature. We will also explore the connection and the missing links between NAFLD and extrahepatic cancers. Interestingly, any relationship between NAFLD and extrahepatic malignancies could be attributable to several shared metabolic risk factors. Overall, obesity, insulin resistance, metabolic syndrome, and related disorders may increase the risk of developing cancer. Therefore, early diagnosis of NAFLD is essential for preventing the progression of the disease and avoiding its severe complications. In addition, cancer screening and early detection in these patients may improve survival and reduce any delays in treatment.

Proteoglycans in Cancer: Friends or Enemies? A Special Focus on Hepatocellular Carcinoma

Simple Summary

Proteoglycans affect multiple molecular and cellular processes during the progression of solid tumors with a highly desmoplastic stroma, such as HCC. Due to their role in enhancing or limiting the traits of cancer cells underlying their aggressiveness, such as proliferation, angiogenesis, epithelial to mesenchymal transition (EMT), and stemness, these macromolecules could be exploited as molecular targets or therapeutic agents. Proteoglycans, such as biglycan, versican, syndecan-1, glypican-3, and agrin, promote HCC cell proliferation, EMT, and angiogenesis, while endostatin and proteoglycan 4 were shown to impair cancer neovascularization or to enhance the sensitivity of HCC cells to drugs, such as sorafenib and regorafenib. Based on this evidence, interventional strategies involving the use of humanized monoclonal antibodies, T cells engineered with chimeric antigen receptors, or recombinant proteins mimicking potentially curative proteoglycans, are being employed or may be adopted in the near future for the treatment of HCC.

Abstract

Proteoglycans are a class of highly glycosylated proteins expressed in virtually all tissues, which are localized within membranes, but more often in the pericellular space and extracellular matrix (ECM), and are involved in tissue homeostasis and remodeling of the stromal microenvironment during physiological and pathological processes, such as tissue regeneration, angiogenesis, and cancer. In general, proteoglycans can perform signaling activities and influence a range of physical, chemical, and biological tissue properties, including the diffusivity of small electrolytes and nutrients and the bioavailability of growth factors. While the dysregulated expression of some proteoglycans is observed in many cancers, whether they act as supporters or limiters of neoplastic progression is still a matter of controversy, as the tumor promoting or suppressive function of some proteoglycans is context dependent. The participation of multiple proteoglycans in organ regeneration (as demonstrated for the liver in hepatectomy mouse models) and in cancer suggests that these molecules actively influence cell growth and motility, thus contributing to key events that characterize neoplastic progression. In this review, we outline the main roles of proteoglycans in the physiology and pathology of cancers, with a special mention to hepatocellular carcinoma (HCC), highlighting the translational potential of proteoglycans as targets or therapeutic agents for the treatment of this disease.

Mediterranean Diet and Fatty Liver Risk in a Population of Overweight Older Italians: A Propensity Score-Matched Case-Cohort Study

Hepatic steatosis, often known as fatty liver, is the most common hepatic disease in Western countries. The latest guidelines for the treatment of nonalcoholic fatty liver disease emphasize lifestyle measures, such as changing unhealthy eating patterns. Using a propensity score-matching approach, this study investigated the effect of adhering to a Mediterranean diet (MedDiet) on fatty liver risk in an older population (≥65 years) from Southern Italy. We recruited 1.403 subjects (53.6% men, ≥65 years) who completed a food frequency questionnaire (FFQ) and underwent clinical assessment between 2015 and 2018. For the assessment of the liver fat content, we applied the Fatty Liver Index (FLI). To evaluate the treatment effect of the MedDiet, propensity score matching was performed on patients with and without FLI > 60. After propensity score-matching with the MedDiet pattern as treatment, we found a higher consumption of red meat (p = 0.04) and wine (p = 0.04) in subjects with FLI > 60. Based on the FLI, the inverse association shown between adherence to the MedDiet and the risk of hepatic steatosis shows that the MedDiet can help to prevent hepatic steatosis. Consuming less red and processed meat, as well as alcoholic beverages, may be part of these healthy lifestyle recommendations.

Weight Gain and Metabolic Syndrome in Human Immunodeficiency Virus Patients

While human immunodeficiency virus (HIV)-associated wasting has declined with significant advances in antiretroviral therapy (ART), weight gain and metabolic syndrome (MetS) are now becoming a problem for people living with HIV (PLWH) worldwide. The development of a new and more effective ART regimen has increased viral suppression and improved immunologic function recovery, leading to the extension of the lifespan of PLWH. It has recently been reported as one of the significant factors associated with weight gain, obesity, and long-term metabolic consequences in PLWH. This article reviewed the epidemiology of overweight and MetS among PLWH and the known risk factors for weight gain and its major comorbidities, such as dyslipidemia, diabetes mellitus, cardiovascular diseases, neurocognitive disorders, and liver diseases, in PLWH. In addition, reports on the pharmacological and surgical management of overweight and obesity in PLWH has been briefly summarized.

Does naringenin supplementation improve lipid profile, severity of hepatic steatosis and probability of liver fibrosis in overweight/obese patients with NAFLD? A randomised, double-blind, placebo-controlled, clinical trial

BACKGROUND AND OBJECTIVES

Naringenin has been reported to have some promising pharmacological effects on the management of obesity and related metabolic complications including non-alcoholic fatty liver disease (NAFLD). Therefore, the present clinical trial study was done to assess the effects of naringenin supplementation on lipid profile, aminotransferase levels, severity of steatosis, as well as probability of fibrosis in overweight/obese patients with NAFLD.

MATERIALS AND METHODS

This placebo-controlled, parallel randomised, double-blind clinical trial study was conducted on 44 eligible overweight/obese patients with NAFLD (naringenin-treated group (n = 22), control group (n = 22)) referred to the national Iranian oil company (NIOC) Central Hospital, Tehran City, Tehran Province, Iran. Participants were randomly assigned to receive naringenin capsules (100 mg) and identical placebo capsules twice a day, before lunch and dinner, for 4 weeks. The primary outcomes were improvement of liver steatosis and NAFLD fibrosis score (NFS), and secondary outcomes included changes in levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lipid profile.

RESULTS

Naringenin consumption significantly reduced percentages of NAFLD grades (P < .001), as well as, serum levels of triglyceride (TG) (P < .001), total cholesterol (TC) (P = .01), and low-density lipoprotein (LDL) (P = .02) and increased serum level of high-density lipoprotein (HDL) (P = .02) compared with the control group. Even after adjusting for the confounders, the results were significant. However, there were no significant changes in AST, ALT and NFS.

CONCLUSION

Our findings revealed that daily intake of 200 mg of naringenin for 4 weeks had beneficial effects on lipid profile and percentages of NAFLD grades as an indicator for the severity of hepatic steatosis. Although, NFS values and serum levels of aminotransferase enzymes including AST and ALT did not remarkably change.

Taurine Reduces Liver Damage in Non-Alcoholic Fatty Liver Disease Model in Rats by Down-Regulating IL-9 and Tumor Growth Factor TGF-β

The study employed a rat model to examine the effects of taurine (Tau) on prevention and therapy of non-alcoholic fatty liver disease (NAFLD). In model rats maintained on a high-fat diet (HFD), the serum levels of ALT, AST, triglycerides, cholesterol, and LDL were higher than the corresponding levels in normal control and NP groups (p<0.05). In Tau-prevention and Tau-treatment groups, the serum levels of AST and triglycerides were lower than in HFD rats (p<0.05). In HFD rats, diffuse fatty degeneration and infiltration with inflammatory cells was observed in the liver; in the ileal mucosa, the villi were fractured or absent, the epithelium was exfoliated and infiltrated with inflammatory cells. The levels of TGF-β, IL-9, and their mRNA in the liver and ileal mucosa of HFD rats were significantly higher than in normal control and NP groups (p<0.05). In Tau-prevention and Tau-treatment groups, these levels were significantly lower than in HFD rats (p<0.05). Thus, TGF-β and IL-9 can be implicated in NAFLD genesis, while Tau can preventively or therapeutically diminish the damage to the liver and ileal mucosa in rats with this disease by down-regulating the expression of TGF-β and IL-9.

Proteome analysis identified proteins associated with mitochondrial function and inflammation activation crucially regulating the pathogenesis of fatty liver disease

Background

Fatty liver disease prevalently occurs in commercial postpartum dairies, resulting in a worldwide high culling rate because of their subsequent limitations of production and reproduction performance.

Results

Fatty liver-specific proteome and acetylome analysis revealed that energy metabolism suppression closely associated with mitochondrial dysfunction and inflammation activation were shown to be remarkable biological processes underlying the development of fatty liver disease, furthermore, acetylation modification of proteins could be one of the main means to modulate these processes. Twenty pivotal genetic factors/genes that differentially expressing and being acetylation modified in liver were identified and proposed to regulate the pathogenesis of fatty liver dairies. These proteins were confirmed to be differentially expressing in individual liver tissue, eight of which being validated via immunohistochemistry assay.

Conclusions

This study provided a comprehensive proteome and acetylome profile of fatty liver of dairy cows, and revealed potential important biological processes and essential regulators in the pathogenesis of fatty liver disease. Expectantly, understanding the molecular mechanisms of the pathogenesis of fatty liver disease in dairies, as an animal model of non-alcoholic fatty liver disease (NAFLD) in human beings, which is a clinico-pathologically defined process associated with metabolic syndrome, could inspire and facilitate the development of efficacious therapeutic drugs on NAFLD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-021-07950-2.

Efficacy of elafibranor in patients with liver abnormalities especially non-alcoholic steatohepatitis: a systematic review and meta-analysis

BACKGROUND

Dyslipidemia is a very common medical disorder affecting nearly 33.5% of US adults over 20 years of age. It represents the major risk factor for non-alcoholic fatty liver (NAFLD) and cardiovascular diseases, which is the most common cause of death worldwide. Elafibranor is a peroxisome proliferator-activated receptor (PPAR) alpha and delta dual agonist. A novel dual peroxisome proliferator-activated receptor alpha/delta (PPAR-α/δ), elafibranor, the agonist is an emerging therapy with promising hepatoprotective results.

OBJECTIVES

To estimate the efficacy of elafibranor in patients with liver abnormalities especially non-alcoholic steatohepatitis (NASH).

METHODS

We searched the following databases: PubMed, SCOPUS, Web of Science, and Cochrane Library for relevant clinical trials assessing the use of silymarin in patients with NAFLD. Risk of bias assessment was performed using Cochrane's risk of bias tool. We included the following outcomes: alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), HOMA-IR, total cholesterol (TC), triglyceride (TG), HDL-cholesterol (HDL-C), and LDL-cholesterol (LDL-C).

RESULTS

We included four clinical trials. We found that elafibranor significantly reduced the levels of ALT {MD = - 4.60 [- 8.17, - 1.04], (P = 0.01)}, GGT {MD = - 16.57 [- 26.59, - 6.56], (P < 0.01)}, TC {MD = - 0.37 [- 0.66, - 0.08], (P = 0.01)}, TG {MD = - 0.37 [- 0.51, - 0.24], (P < 0.01)}, ALP {(MD = - 14.45 [- 18.99, - 9.91], (P < 0.01)}, and LDL {MD = - 0.20 [- 0.33, - 0.07], (P = 0.003)}. There was no significant difference regarding HOMA-IR {MD = - 0.32 [- 0.88, 0.24], (P = 0.26) and AST (P = 0.53).

CONCLUSION

PPAR-alpha/delta dual agonist, elafibranor, is a promising drug that improves most metabolic parameters in dyslipidemic patients.

Eucaloric diets enriched in palm olein, cocoa butter, and soybean oil did not differentially affect liver fat concentration in healthy participants: a 16-week randomized controlled trial

BACKGROUND

Effects of dietary fat quality on liver fat remain to be elucidated. Inconsistent evidence may be influenced by fatty acid saturation, chain-length, and regio-specificity within triacylglycerol (TAG) molecules.

OBJECTIVES

We aimed to compare eucaloric diets enriched in palm olein (POo), cocoa butter (COB), and soybean oil (SBO) on liver fat concentration in healthy participants. Secondary outcomes included visceral (VAT) and abdominal subcutaneous (aSCAT) adipose tissue, plus other obesity and cardiometabolic health outcomes.

METHODS

Eighty-three healthy participants (20-45 y, BMI 18.5-27.5 kg/m2) commenced and 64 completed a 16-wk randomized parallel intervention, preceded by a 2-wk run-in. Participants consumed identical eucaloric background diets differing in test fats [contributing 20% total energy intake (%E)], providing 33%E total fat with the following ratios for PUFAs/SFAs/MUFAs: POo, 4.2/13.5/15%E; SBO, 14.4/8.8/9.4%E; COB, 2.3/19.5/11%E. Liver fat and abdominal adiposity were measured at weeks 0 and 16 using 1H-magnetic resonance spectroscopy/imaging; all other outcomes were measured at 0, 4, 8, 12, and 16 wk.

RESULTS

Fat quality did not affect liver fat concentration, VAT, aSCAT, obesity indexes, blood pressure, liver enzymes, leptin, or fasting glucose. Body fat mass decreased with SBO and COB compared with POo. SBO decreased serum total cholesterol (TC), LDL cholesterol, and TC:HDL cholesterol relative to POo [estimated marginal mean (95% CI) differences: -0.57 (-0.94, -0.20) mmol/L; -0.37 (-0.68, -0.07) mmol/L; and -0.42 (-0.73, -0.11) mmol/L, respectively]. No diet differences were observed on HDL cholesterol, TAG, apoA1, apoB, apoB:apoA1, or fecal free fatty acids (FFAs), except for lower FFA pentadecanoic acid (15:0) with COB than with SBO and POo.

CONCLUSIONS

In healthy adults, when consumed as part of eucaloric typical Australian diets, 3 different dietary fat sources did not differentially affect liver fat concentration and amounts of adipose tissue. Effects on serum lipids were inconsistent across lipid profiles. The findings must be confirmed in metabolically impaired individuals before recommendations can be made.

Serum Micro-RNA-122 Level as a Simple Noninvasive Marker of MAFLD Severity

BACKGROUND

Metabolic-associated fatty liver disease (MAFLD) is a common disease worldwide. Micro-RNA-122 is known to be the most abundant micro-RNA expressed in the liver.

OBJECTIVE

To evaluate the association of micro-RNA-122 and the degree of steatosis and fibrosis in obese patients with MAFLD.

METHODS

The study included 120 obese Egyptian patients with MAFLD, which were diagnosed and classified according to ultra-sonographic liver findings. All patients enrolled in the study were subjected to thorough clinical examination and laboratory investigations (serum micro-RNA-122 levels by PCR, lipid profile, liver biochemistry, and functions). Fibro-scan was used to assess the level of fibrosis.

RESULTS

There was a significant increase in levels of micro-RNA-122 in obese patients with MAFLD compared to controls (p<0.001). Micro-RNA-122 level was lower in patients with mild liver steatosis than patients with moderate or severe steatosis (p<0.001). It was lower in patients with a mild degree of fibrosis than those with mild or moderate fibrosis (p<0.001). Micro-RNA-122 was significantly positively correlated with low-density cholesterol and triglycerides level, and liver enzymes, and negatively correlated to high-density cholesterol (p<0.001).

CONCLUSION

Serum micro-RNA-122 could be a useful predictor of assessing MAFLD severity regarding level of steatosis or fibrosis.

A novel bile acid analog, A17, ameliorated non-alcoholic steatohepatitis in high-fat diet-fed hamsters

Being endocrine signaling molecules that regulate lipid metabolism and affect energy balance, bile acids are potential drug candidates for non-alcoholic steatohepatitis (NASH). Obeticholic acid (OCA) could improve NASH accompanied by significant side effects. Therefore, it is worthwhile to develop safer and more effective bile acid analogs. In this study, a new bile acid analog A17 was synthesized and its potential anti-NASH effects were assessed in vitro and in vivo. The impact of A17 on steatosis was investigated in the rat primary hepatocytes challenged with oleic acid. It was found that A17 alleviated lipid accumulation by reducing fatty acid (FA) uptake and promoting FA oxidation. The reduction of FA uptake came from inhibiting fatty acid translocase (Cd36) expression. The promotion of FA oxidation came from stimulating the phosphorylation of adenosine monophosphate (AMP)-activated protein kinase alpha (AMPKα). In addition, A17 reduced lipopolysaccharide-induced inflammation in Raw264.7 cells by activating Takeda G protein-coupled receptor 5 (TGR5). In in vivo study, male Golden Syrian hamsters were fed with high fat (HF) diet and then treated with 50 mg/kg/d A17 for 6 weeks. A17 lowered the lipid profiles and liver enzyme levels in serum and improved liver pathological conditions with less side effects compared with OCA. Further studies confirmed that the molecular mechanisms of A17 in vivo were similar to those in vitro. In conclusion, a novel bile acid analog A17 was identified to ameliorate NASH in HF-fed hamsters. The potential mechanisms could be contributed to reducing FA uptake, stimulating FA oxidation and relieving inflammation.

Efficacy of Glucagon-Like Peptide-1 Analogs in Nonalcoholic Fatty Liver Disease: A Systematic Review

Background

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease. It is believed to be the hepatic manifestation of the metabolic syndrome. Many treatment approaches have been suggested so far, and several types of studies have been done to find treatment for NAFLD, the most promising of which are those with lifestyle interventions.

Objective

The aim of this systematic review was to evaluate the efficacy and safety of glucagon-like peptide-1 (GLP-1) analogs on the management of NAFLD.

Methods

The PubMed, MEDLINE, and Cochrane Central Library were searched to identify randomized controlled trials, single arm trials, and cohorts that compared GLP-1 analogs with a control treatment or baseline values with respect to efficacy and safety in patients living with NAFLD. The key outcomes were a change in serum transaminase, resolution of disease status measured by imaging or histological techniques, improvement in insulin resistance, and reduction in body weight.

Results

Initial searching retrieved 201 peer-reviewed articles and abstracts. Ten studies met all inclusion criteria. The review included a total of 590 participants with NAFLD. Following administration of GLP-1 analogs, a decrease in serum transaminases, improvement in liver histology and insulin resistance, and a reduction in body weight were observed. Compared with baseline, body weight, alanine aminotransferase, aspartate aminotransferase, and gamma glutamyltransferase were decreased by 5.5%, 59.5%, 52.8%, and 44.8%, respectively, due to GLP-1. Likewise, a reduction of proinflammatory cytokines and fibrosis markers and an enhancement of protective adipokines were observed in some of the studies.

Conclusion

The decrease in a key biochemical marker of liver injury following treatment with GLP-1 analogs, as well as improvements in imaging and histology, suggests that these agents may be effective alternatives for managing NAFLD.

Registration

CRD42018087262.

Expression of Matrix Metalloproteinases and Their Tissue Inhibitors in Peripheral Blood Leukocytes and Plasma of Children with Nonalcoholic Fatty Liver Disease

Gene expression profiles of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) were evaluated in peripheral blood leukocytes of children with nonalcoholic fatty liver disease (NAFLD). Gene expression patterns were correlated with their plasma protein counterparts, systemic parameters of liver injury, and selected markers of inflammation. The MMP-2, MMP-9, MMP-12, MMP-14, TIMP-1, TIMP-2, TGF-β, and IL-6 transcripts levels were tested by the real-time PCR. Plasma concentrations of MMP-9, TIMP-1, MMP-9/TIMP-1 ratio, MMP-2/TIMP-2 ratio, sCD14, leptin, resistin, IL-1 beta, and IL-6 and serum markers of liver injury were estimated by ELISA. The MMP-9, TIMP-2 expression levels, plasma amounts of MMP-9, TIMP-1, and the MMP-9/TIMP-1 ratio were increased in children with NAFLD. Concentrations of AST, ALT, GGT, and leptin were elevated in serum patients with NAFLD, while concentration of other inflammatory or liver injury markers was unchanged. The MMP-2 and MMP-9 levels correlated with serum liver injury parameters (ALT and GGT concentrations, respectively); there were no other correlations between MMP/TIMP gene expression profiles, their plasma counterparts, and serum inflammatory markers. Association of MMP-2 and MMP-9 expression with serum liver injury parameters (ALT, GGT) may suggest leukocyte engagement in the early stages of NAFLD development which possibly precedes subsequent systemic inflammatory responses.

Correlation between the small dense LDL level and nonalcoholic fatty liver disease: Possibility of a new biomarker

Small dense low-density lipoprotein (sdLDL) is a distinct low-density lipoprotein (LDL) cholesterol subclass that has been reported to be associated with metabolic disease. On the other hand, the relationship between the sdLDL level and the nonalcoholic fatty liver disease (NAFLD) severity is unclear. In this study, the sdLDL level was measured in patients with NAFLD to assess its potential as a biomarker for evaluating NAFLD. One hundred and twenty-six patients diagnosed with NAFLD at a single referral hospital from January 2018 to August 2019 were enrolled. The lipoprotein profile was analyzed from a blood test of NAFLD patients, and transient elastography (TE, Fibroscan) was performed to evaluate the degree of NAFLD. Among the 126 patients, 83 patients that could confirm the lipoprotein profile and TE results were finally enrolled in the study. The controlled attenuation parameter (CAP) value obtained from TE did not show any correlation with the total cholesterol, LDL. But, the sdLDL level showed a significant positive correlation with the CAP value (r = 0.237, P = .031), and the sdLDL/LDL ratio also showed a significant positive correlation with the CAP value (r = 0.235, P = .032). The liver stiffness (LS) measured by TE and the sdLDL level were positively correlated in patients with NAFLD (rho = 0.217, P = .049). The sdLDL/LDL ratio also showed a significant positive correlation with the LS value (rho = 0.228, P = .038). In addition, the fatty liver index also showed a significant positive correlation with the sdLDL/LDL ratio (r = 0.448, P = .000). In this study, the sdLDL level measured by a blood test of NAFLD patients showed a positive correlation with the CAP value and LS, which indicate the degree of hepatic steatosis and fibrosis. These results suggest the possibility of the sdLDL level as a new biomarker of NAFLD, but further studies will be needed to support these results.

Protein acetylation in mitochondria plays critical functions in the pathogenesis of fatty liver disease

BACKGROUND

Fatty liver is a high incidence of perinatal disease in dairy cows caused by negative energy balance, which seriously threatens the postpartum health and milk production. It has been reported that lysine acetylation plays an important role in substance and energy metabolism. Predictably, most metabolic processes in the liver, as a vital metabolic organ, are subjected to acetylation. Comparative acetylome study were used to quantify the hepatic tissues from the severe fatty liver group and normal group. Combined with bioinformatics analysis, this study provides new insights for the role of acetylation modification in fatty liver disease of dairy cows.

RESULTS

We identified 1841 differential acetylation sites on 665 proteins. Among of them, 1072 sites on 393 proteins were quantified. Functional enrichment analysis shows that higher acetylated proteins are significantly enriched in energy metabolic pathways, while lower acetylated proteins are significantly enriched in pathways related to immune response, such as drug metabolism and cancer. Among significantly acetylated proteins, many mitochondrial proteins were identified to be interacting with multiple proteins and involving in lipid metabolism. Furthermore, this study identified potential important proteins, such as HADHA, ACAT1, and EHHADH, which may be important regulatory factors through modification of acetylation in the development of fatty liver disease in dairy cows and possible therapeutic targets for NAFLD in human beings.

CONCLUSION

This study provided a comprehensive acetylome profile of fatty liver of dairy cows, and revealed important biological pathways associated with protein acetylation occurred in mitochondria, which were involved in the regulation of the pathogenesis of fatty liver disease. Furthermore, potential important proteins, such as HADHA, ACAT1, EHHADH, were predicted to be essential regulators during the pathogenesis of fatty liver disease. The work would contribute to the understanding the pathogenesis of NAFLD, and inspire in the development of new therapeutic strategies for NAFLD.

Similar prevalence of hepatic steatosis among patients with chronic hepatitis C with and without HIV coinfection

Hepatic steatosis (HS) is frequently observed in HIV-infected patients. It is not known whether HIV infection is an independent risk factor for HS development. We aimed to analyze whether HIV coinfection was associated with a higher frequency of HS in patients with chronic hepatitis C. This was a retrospective cross-sectional study. 574 subjects with chronic hepatitis C virus (HCV) infection were included, 246 (43%) of them coinfected with HIV. All of them underwent transient elastography with controlled attenuation parameter (CAP) measurement. HS was defined as CAP ≥ 248 dB/m. 147 individuals (45%) showed HS in the HCV-monoinfected group and 100 (40.7%) in the HIV/HCV-coinfected group (p = 0.318). HS was associated with body mass index (BMI) [<25 Kg/m² vs. ≥25 Kg/m², 67 (23.5%) vs. 171 (62.9%); p = 0.001], with plasma HDL-cholesterol [<50 mg/dL vs. ≥50 mg/dL, 122 (48.6%) vs. 95 (37.5%), p = 0.012], with plasma triglycerides [<150 mg/dL vs. ≥150 mg/dL, 168 (40.2%) vs. 65 (52.4%); p = 0.016] and with plasma total cholesterol [<200 mg/dL vs. ≥200 mg/dL, 181 (41%) vs. 53 (52.5%); p = 0.035]. In the multivariate analysis, HS was associated with BMI [adjusted OR (AOR) = 1.264 (1.194–1.339); p = 0.001], age [AOR = 1.029 (1.001–1.058); p = 0.047] and HCV genotype 3 infection [AOR = 1.901 (1.081–2.594); p = 0.026]. HIV coinfection was not associated with HS [AOR = 1.166 (0.719–1.892); p = 0.534]. In conclusion, HIV coinfection is not related with an increased frequency of HS in HCV-infected patients.

Identification of Crucial Genetic Factors, Such as PPARγ, that Regulate the Pathogenesis of Fatty Liver Disease in Dairy Cows Is Imperative for the Sustainable Development of Dairy Industry

Frequently occurring fatty liver disease in dairy cows during the perinatal period, a typical type of non-alcoholic fatty liver disease (NAFLD), results in worldwide high culling rates of dairy cows (averagely about 25%) after calving. This has been developing into a critical industrial problem throughout the world, because the metabolic disease severely affects the welfare and economic value of dairy cows. Findings about the molecular mechanisms how the fatty liver disease develops would help scientists to discover novel therapeutic targets for NAFLD. Studies have shown that PPARγ participates or regulates the fat deposition in liver by affecting the biological processes of hepatic lipid metabolism, insulin resistance, gluconeogenesis, oxidative stress, endoplasmic reticulum stress and inflammation, which all contribute to fatty liver. This review mainly focuses on crucial regulatory mechanisms of PPARγ regulating lipid deposition in the liver via direct and/or indirect pathways, suggesting that PPARγ might be a potential critical therapeutic target for fatty liver disease, however, it would be of our significant interest to reveal the pathology and pathogenesis of NAFLD by using dairy cows with fatty liver as an animal model. This review will provide a molecular mechanism basis for understanding the pathogenesis of NAFLD.

Effectiveness of phosphatidylcholine as adjunctive therapy in improving liver function tests in patients with non-alcoholic fatty liver disease and metabolic comorbidities: real-life observational study from Russia

Objective

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of abnormal results of liver function tests. Earlier research showed that polyenylphosphatidylcholine (PPC) has hepatoprotective effects and thus can be used for the treatment of NAFLD and the prevention of its progression. Accordingly, the aim of this observational study was to evaluate if PPC administered as adjunctive therapy in routine clinical practice can effectively improve liver function tests of NAFLD in Russian patients with associated metabolic comorbidities.

Design

A total of 2843 adult patients with newly diagnosed NAFLD, who had a least one of four comorbidities, namely, overweight/obesity, hypertension, type 2 diabetes mellitus, and hypercholesterolaemia, and who were prescribed 1.8 g/day of PPC as an adjunctive treatment to standard care, were enrolled during 2015-2016. Laboratory data were collected at baseline and 12 and 24 weeks of the study, and included liver function tests (aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT)), fasting plasma glucose, and lipid profile.

Results

Overall, 2263 patients (79.6%) had at least two metabolic comorbidities associated with NAFLD, and overweight/obesity was the most common comorbidity reported in 2298 (80.8%) patients. At 24 weeks, there was a significant decrease in liver enzyme levels (all p<0.001 compared with baseline). Across the four comorbidity subgroups, there was a mean drop of ALT levels ranging from 19.7 to 22.0 U/L, AST from 16.9 to 18.4 U/L, and GGT from 17.2 to 18.7 U/L. Similar findings were reported in subgroups with either one, two, three, or four comorbidities, with a significant decrease in liver enzyme levels ranging from 18.4 to 22.4 U/L for ALT, 14.8 to 18.7 U/L for AST, and 15.5 to 19.5 U/L for GGT.

Conclusions

Adjuvant treatment with PPC resulted in consistent improvements in liver enzymes in patients with newly diagnosed NAFLD and associated metabolic comorbidities.

Trial registration number

NCT00063622.

Decreased PEDF Promotes Hepatic Fatty Acid Uptake and Lipid Droplet Formation in the Pathogenesis of NAFLD

Non-alcoholic fatty liver disease (NAFLD), the leading cause of chronic liver diseases worldwide, ranges from simple steatosis to steatohepatitis, with the risk for progressive fibrosis or even cirrhosis. While simple steatosis is a relatively benign condition, the buildup of toxic lipid metabolites can induce chronic inflammation, ultimately triggering disease progression. Pigment epithelium-derived factor (PEDF) is a secreted, multifunctional glycoprotein with lipid metabolic activities. PEDF promotes lipolysis through binding to adipose triglyceride lipase (ATGL), a key enzyme for triglyceride breakdown. In the current study, we aimed to delineate how changes in PEDF expression affect hepatic lipid accumulation. Our data revealed that hepatic PEDF was downregulated in a mouse NAFLD model. We further showed that decreased PEDF levels in hepatocytes in vitro resulted in elevated fatty acid uptake and lipid droplet formation, with concomitant upregulation of fatty acid transport proteins CD36 and fatty acid binding protein 1 (FABP1). RNA sequencing analysis of PEDF knocked down hepatocytes revealed an alteration in gene expression profile toward lipid accumulation. Additionally, decreased PEDF promotes mobilization of fatty acids, an observation distinct from blocking ATGL activity. Taken together, our data suggest that hepatic PEDF downregulation causes molecular changes that favor triglyceride accumulation, which may further lead to NAFLD progression.

Improvement Effects of Trehangelin A on High-Fat Diet Causing Metabolic Clinical Conditions

The purpose of this study is to determine whether or not trehangelin A (THG-A) is effective in treating the metabolic clinical condition caused by a high-fat diet. The body weight, epididymal adipose volume, alanine transaminase (ALT), total-cholesterol (T-CHO), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C) and glucose concentrations in serum increased in mice fed a high-fat diet compared to mice fed a control diet. On the other hand, adiponectin level in serum of mice fed a high-fat diet decreased compared to that of control mice. When mice fed a high-fat diet were intraperitoneally administered THG-A of 20 mg/kg three times per week, the levels of TG and glucose in serum were significantly reduced compared to those fed high-fat without THG-A. Interestingly, the levels of high-density lipoprotein cholesterol (HDL-C) in serum were increased by THG-A administration in both mice fed a control diet and those fed high-fat diet. The decreased level of adiponectin by a high-fat diet was also recovered by THG-A treatment. The liver expression of mRNA from pro-inflammatory cytokines, including interleukin (IL)-6 and tumor necrosis factor (TNF)-α, were significantly increased in mice fed a high-fat diet compared to those fed a control diet. However, the increased IL-6 levels in mice fed a high-fat diet were significantly suppressed by THG-A treatment. Furthermore, the increased expression of TNF-α mRNA or COL1A2 mRNA by a high-fat diets tended to be decreased in mice treated with THG-A. These results show that THG-A treatment attenuates the progression of metabolic clinical conditions, suggesting its potential efficacy against obesity-related metabolic disorders.

Association of tissue inhibitor of metalloproteinase 2 with non-alcoholic fatty liver disease in metabolic syndrome

The aim of this case-control study was to assess TIMP2 level in subjects with or without metabolic syndrome (MetS) and to associate levels with non-alcoholic fatty liver changes (NAFLD). Thirty-three MetS subjects and 55 controls were recruited. Anthropometric data, lipid and glucose profile, TIMP2 and liver ultrasound was performed. High TIMP2 was seen in MetS group (145.28 ± 23.11 pg/ml) versus controls (19.06 ± 1.19 pg/ml; p < .001). Serum cholesterol, triglyceride, LDL-c and glucose levels were significantly higher in MetS subjects (p < .05). MetS individuals (72.72%) showed positive fatty liver changes versus 14.5% controls. Elevated TIMP2 positively correlated with waist circumference, body fat, blood glucose and NAFLD. Furthermore, every unit rise in waist circumference and TIMP2 and a unit decrease in HDL were associated with higher odds of developing NAFLD (p < .05). There may be concurrent relationship between TIMP2 and NAFLD in MetS that requires further evaluation to improve risk assessment and early diagnosis of MetS.

Arid1a regulates insulin sensitivity and lipid metabolism

Background

Although significant progress has been made in understanding the mechanisms of steatosis and insulin resistance, the physiological functions of the epigenetic regulators in these processes remain largely elusive.

Methods

Hepatocyte-specific Arid1a knockout mice were administrated with high-fat diet (HFD) for 12 weeks, then insulin sensitivity was assessed by glucose tolerance test (GTT) and insulin tolerance test (ITT). The metabolism-related indicators were determined by employing a variety of biological methods, including histology, real-time PCR, enzyme-linked immunosorbent assay (ELISA), Western blotting assay, Chromatin immunoprecipitation (ChIP), RNA-seq and assay for Transposase-Accessible Chromatin with high-throughput sequencing (ATAC-seq).

Findings

Hepatocyte-specific Arid1a deletion significantly increases susceptibility to develop hepatic steatosis, insulin resistance and inflammation in mice fed a HFD. In vitro, Arid1a deletion in isolated hepatocytes directly leads to free fatty acid-induced lipid accumulation and insulin resistance. Mechanically, Arid1a deficiency impairs fatty acid oxidation by downregulating PPARα and altering the epigenetic landscape of some metabolism genes.

Interpretation

These findings reveal that targeting Arid1a might be a promising therapeutic strategy for liver steatosis and insulin resistance.

Fund

This work was supported by National Natural Science Foundation of China (81672772 and 81472621), China National Science and Technology Major Project for Prevention and Treatment of Infectious Diseases (No.2017ZX 10203207) and National Program on Key Research Project of China (grant no. 2016YFC0902701).

Steatosis Rates by Liver Biopsy and Transient Elastography With Controlled Attenuation Parameter in Clinical Experience of Hepatitis C Virus (HCV) and Human Immunodeficiency Virus/HCV Coinfection in a Large US Hepatitis Clinic

Background

Steatosis contributes to liver fibrosis in hepatitis C virus (HCV) and human immunodeficiency virus (HIV)/HCV coinfection. Liver biopsy (LB) is the reference standard for grading steatosis and staging fibrosis, yet recent advances in noninvasive modalities have largely supplanted LB, which may limit recognition of steatosis. We evaluated steatosis rates by LB and transient elastography (TE) with controlled attenuation parameter (CAP) among HCV-infected and HIV/HCV-coinfected patients in a US clinic.

Methods

Patients with chronic HCV infection during pretreatment evaluation by LB (n = 421; December 2001 through May 2014) and TE with CAP (n = 1157; May 2016 through May 2017) were included. Fibrosis and steatosis rates by LB and TE with CAP were stratified by HCV versus HIV/HCV coinfection status.

Results

Steatosis was not reported in 26.1% of LBs. Moderate to severe steatosis (grade ≥S2) was detected more often with CAP than with LB (in 24.0% vs 11.4% of patients, respectively). Median CAP values were higher in patients with HCV monoinfection than in those with coinfection (230 vs 215.5 dB/m, respectively; P < .001). With TE, the rate of advanced fibrosis (values F3–F4) was higher in HCV monoinfection than in coinfection (25.9% vs 14.8%, respectively; P <.001). With both LB and TE, advanced fibrosis (F3–F4) was significantly associated with moderate to severe steatosis (S2–S3) in HCV monoinfection compared with HIV/HCV coinfection (33.3% vs 4.4%, respectively for LB [P = 0.003] and 36.0% vs 29.0% for TE [P = 0.008]).

Conclusions

In patients with chronic HCV undergoing liver fibrosis staging, steatosis was detected more often with CAP than LB, with median CAP values higher in HCV monoinfection than HIV/HCV coinfection. Steatosis severity may be increasing in the modern HCV treatment era.

PPARδ attenuates hepatic steatosis through autophagy-mediated fatty acid oxidation

Peroxisome proliferator-activated receptor δ (PPARδ) belongs to the nuclear receptor family and is involved in metabolic diseases. Although PPARδ is known to attenuate hepatic lipid deposition, its mechanism remains unclear. Here, we show that PPARδ is a potent stimulator of hepatic autophagic flux. The expression levels of PPARδ and autophagy-related proteins were decreased in liver tissues from obese and ageing mice. Pharmacological and adenovirus-mediated increases in PPARδ expression and activity were achieved in obese transgenic db/db and high fat diet-fed mice. Using genetic, pharmacological and metabolic approaches, we demonstrate that PPARδ reduces intrahepatic lipid content and stimulates β-oxidation in liver and hepatic cells by an autophagy-lysosomal pathway involving AMPK/mTOR signalling. These results provide novel insight into the lipolytic actions of PPARδ through autophagy in the liver and highlight its potential beneficial effects in NAFLD.

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.

Statin Therapy Does Not Reduce Liver Fat Scores in Patients Receiving Antiretroviral Therapy for HIV Infection

BACKGROUND & AIMS

Therapies are needed to limit progression of fatty liver diseases in patients with human immunodeficiency virus (HIV) infection. We analyzed data from a prospective study of the effects of rosuvastatin (a statin) on hepatic steatosis in HIV-positive adults.

METHODS

We performed a secondary analysis of data from a double-blind trial of adult patients with HIV infection (78% male; 68% African American; mean age, 46 y; body mass index, 29 kg/m²; HIV1 RNA < 1000 copies/mL; low-density lipoprotein cholesterol, <130 mg/dL) receiving antiretroviral therapy. The patients were randomly assigned to groups given 10 mg daily rosuvastatin (n = 72) or placebo (n = 75). Demographic and clinical data were collected, and blood samples were analyzed. Changes in liver fat score (LFS, a composite score calculated from metabolic and liver function parameters) and markers of systemic inflammation and immune activation were assessed through 96 weeks of drug or placebo administration. We performed multivariable linear and logistic regressions to study relationships among variables.

RESULTS

The placebo and rosuvastatin groups each had significant increases in LFS, compared with baseline, at 96 weeks (P = .01 and P < .01; P = .49 for difference increase between groups). Baseline LFS was independently associated with blood level of C-X-C motif chemokine ligand 10 (P = .04) and the soluble CD163 molecule (P = .01). After we adjusted for baseline characteristics, an increase in LFS over time was significantly associated with the blood level of C-X-C motif chemokine ligand 10 (P = .04), insulin resistance (P < .01), and viral load (P = .02), but not rosuvastatin use (P = .06).

CONCLUSIONS

In a secondary analysis of data from a trial of patients receiving treatment for HIV infection, hepatic steatosis increased over time, regardless of statin treatment, and was independently associated with markers of immune activation. Patients who received rosuvastatin appeared to have a nonsignificant increase in hepatic steatosis over 96 weeks. Despite their ability to reduce the risk of cardiovascular disease, statins do not appear to reduce hepatic steatosis. Clinicaltrials.gov no: NCT01218802.

Serum biomarkers of fibrosis and extracellular matrix remodeling in patients with nonalcoholic fatty liver disease: association with liver histology

BACKGROUND

We sought to explore the interplay of multiple serum biomarkers of fibrosis and extracellular matrix remodeling with the results of liver histology in patients with nonalcoholic fatty liver disease (NAFLD).

PATIENTS AND METHODS

Venous blood samples were collected from 80 patients with biopsy-proven NAFLD and 59 age-matched and sex-matched healthy controls. Serum levels of transforming growth factor (TGF)-β1, TGF-β2, matrix metalloproteinases (MMP)-1, MMP-2, MMP-7, MMP-9, MMP-10, tissue inhibitors of metalloproteinase (TIMP)-1, and TIMP-2 were determined by using the Luminex MagPix technology on a MAGPIX analyzer.

RESULTS

We documented significant differences in the levels of TGF-β1, TGF-β2, MMP-2, MMP-7, MMP-9, TIMP-1, and TIMP-2 between NAFLD patients and controls. However, none of these biomarkers was able to distinguish between nonalcoholic steatohepatitis and nonalcoholic fatty liver. TIMP-1 levels were significantly higher in patients with significant fibrosis (fibrosis stage ≥2; 2624±1261 pg/ml) than in those without (fibrosis stage 0-1; 2096±906 pg/ml; P=0.03). Moreover, serum levels of TIMP-1 were identified as the only independent predictor of histological fibrosis (β=0.298, t=2.7, P=0.007).

CONCLUSION

Our study provides insights into the association of multiple serum biomarkers of fibrosis and extracellular matrix remodeling with NAFLD histology. Notably, serum levels of TIMP-1 were identified as a clinically useful marker for distinguishing NAFLD patients with and without significant fibrosis.

The relationship between vitamin C status, the gut-liver axis, and metabolic syndrome

Metabolic syndrome (MetS) is a constellation of cardiometabolic risk factors, which together predict increased risk of more serious chronic diseases. We propose that one consequence of dietary overnutrition is increased abundance of Gram-negative bacteria in the gut that cause increased inflammation, impaired gut function, and endotoxemia that further dysregulate the already compromised antioxidant vitamin status in MetS. This discussion is timely because "healthy" individuals are no longer the societal norm and specialized dietary requirements are needed for the growing prevalence of MetS. Further, these lines of evidence provide the foundational basis for investigation that poor vitamin C status promotes endotoxemia, leading to metabolic dysfunction that impairs vitamin E trafficking through a mechanism involving the gut-liver axis. This report will establish a critical need for translational research aimed at validating therapeutic approaches to manage endotoxemia-an early, but inflammation-inducing phenomenon, which not only occurs in MetS, but is also prognostic of more advanced metabolic disorders including type 2 diabetes mellitus, as well as the increasing severity of nonalcoholic fatty liver diseases.

Pharmacological Applications of Bile Acids and Their Derivatives in the Treatment of Metabolic Syndrome

Apart from well-known functions of bile acids in digestion and solubilization of lipophilic nutrients and drugs in the small intestine, the emerging evidence from the past two decades identified the role of bile acids as signaling, endocrine molecules that regulate the glucose, lipid, and energy metabolism through complex and intertwined pathways that are largely mediated by activation of nuclear receptor farnesoid X receptor (FXR) and cell surface G protein-coupled receptor 1, TGR5 (also known as GPBAR1). Interactions of bile acids with the gut microbiota that result in the altered composition of circulating and intestinal bile acids pool, gut microbiota composition and modified signaling pathways, are further extending the complexity of biological functions of these steroid derivatives. Thus, bile acids signaling pathways have become attractive targets for the treatment of various metabolic diseases and metabolic syndrome opening the new potential avenue in their treatment. In addition, there is a significant effort to unveil some specific properties of bile acids relevant to their intrinsic potency and selectivity for particular receptors and to design novel modulators of these receptors with improved pharmacokinetic and pharmacodynamic profiles. This resulted in synthesis of few semi-synthetic bile acids derivatives such as 6α-ethyl-chenodeoxycholic acid (obeticholic acid, OCA), norursodeoxycholic acid (norUDCA), and 12-monoketocholic acid (12-MKC) that are proven to have positive effect in metabolic and hepato-biliary disorders. This review presents an overview of the current knowledge related to bile acids implications in glucose, lipid and energy metabolism, as well as a potential application of bile acids in metabolic syndrome treatment with future perspectives.

The suppressive effect of the three-herb extract mixture on vascular and liver inflammation in atherogenic diet with high fructose-fed mice

CONTEXT

Cynanchum wilfordii (Maximowicz) Hemsley (Apocynaceae), Arctium lappa L. var. rubescens Frivald (Asteraceae) and Dioscorea opposite Thunb (Dioscoreaceae) root extracts have been widely used as an alternative for intervening obesity.

OBJECTIVES

The synergistic effect of three-herb mixture of C. wilfordii, A. lappa and D. opposita was determined on aortic and liver inflammatory responses.

MATERIALS AND METHODS

CWE, ALE and DOE were prepared from the root of C. wilfordii, A. lappa and D. opposite by 70% ethanol extraction, respectively. CADE was prepared using a powder mixture of 2 CWE:1 ALE:1 DOE. C57BL/6 mice were fed an atherogenic diet combined with 10% fructose (ATHFR) in the presence of 200 mg/kg/day CWE, ALE, DOE or CADE for 8 weeks (each group, n = 6). Biochemical profiles, protein expression of vascular cell adhesion molecule-1 (VCAM-1) on the aorta and liver were determined.

RESULTS

CADE could significantly suppress the protein expression of VCAM-1 in both the aorta and liver (80% reduction) compared to ATHFR-fed mice. Impairment of liver function was significantly ameliorated by CADE supplement, as determined by GOT (60% reduction) and GPT (51% reduction) levels.

CONCLUSIONS

CADE should be considered when developing medications to suppress the vascular and liver inflammatory responses for individuals who are either non-responsive or resistant to lipid-lowering drugs.

The Role of Long Non-Coding RNAs (lncRNAs) in the Development and Progression of Fibrosis Associated with Nonalcoholic Fatty Liver Disease (NAFLD)

Nonalcoholic fatty liver disease (NAFLD) encompasses a spectrum of conditions ranging from hepatic steatosis to inflammation (nonalcoholic steatohepatitis or NASH) with or without fibrosis, in the absence of significant alcohol consumption. The presence of fibrosis in NASH patients is associated with greater liver-related morbidity and mortality; however, the molecular mechanisms underlying the development of fibrosis and cirrhosis in NAFLD patients remain poorly understood. Long non-coding RNAs (lncRNAs) are emerging as key contributors to biological processes that are underpinning the initiation and progression of NAFLD fibrosis. This review summarizes the experimental findings that have been obtained to date in animal models of liver fibrosis and NAFLD patients with fibrosis. We also discuss the potential applicability of circulating lncRNAs to serve as biomarkers for the diagnosis and prognosis of NAFLD fibrosis. A better understanding of the role played by lncRNAs in NAFLD fibrosis is critical for the identification of novel therapeutic targets for drug development and improved, noninvasive methods for disease diagnosis.

Fatty liver mediated by peroxisome proliferator-activated receptor-α DNA methylation can be reversed by a methylation inhibitor and curcumin

OBJECTIVE

Our studies in vitro and in vivo aimed to investigate the influence of DNA methylation of peroxisome proliferator activated receptor-α (PPAR-α) gene in non-alcoholic fatty liver disease (NAFLD) pathogenesis and to observe whether the DNA methylation inhibitor 5-Aza-2'-deoxycytidine (5-Aza-CdR) and the herbal medicine curcumin might reverse the effect both in vivo and in vitro.

METHODS

Steatotic hepatocyte model of cell lines and NAFLD rat models were established following protocols documented in previous studies. Subsequently, the models received 5-Aza-CdR and curcumin treatment. Morphological, histological and laboratory variables in each group were determined by routine methods, including PPAR-α mRNA expression by polymerase chain reaction (PCR), PPAR-α protein expression by Western blot and DNA methylation by pyrosequencing.

RESULTS

The steatotic hepatocyte model and NAFLD rat model were completely established. The expressions of PPAR-α mRNA and protein were significantly lower in the steatotic hepatocyte and NAFLD rat model groups than in the controls (P < 0.05). The mean DNA methylation levels of the PPAR-α gene were significantly higher in the two steatotic model groups than in the controls, especially at several CpG sites (P < 0.05). 5-Aza-CdR and curcumin treatment significantly reversed the DNA methylation levels, increased PPAR-α mRNA and protein expression, and improved lipid accumulation in the two steatotic models (P < 0.05).

CONCLUSIONS

DNA methylation at the PPAR-α gene is involved in the pathogenesis of NAFLD and is possibly reversible by 5-Aza-CdR and curcumin. Curcumin may be a promising candidate for NAFLD therapy.

Changes in Liver Steatosis After Switching From Efavirenz to Raltegravir Among Human Immunodeficiency Virus-Infected Patients With Nonalcoholic Fatty Liver Disease

Background

Antiretroviral drugs with a lower potential to induce hepatic steatosis in human immunodeficiency virus (HIV) infection need to be identified. We compared the effect of switching efavirenz (EFV) to raltegravir (RAL) on hepatic steatosis among HIV-infected patients with nonalcoholic fatty liver disease (NAFLD) receiving EFV plus 2 nucleoside analogues.

Methods

HIV-infected patients on EFV plus tenofovir/emtricitabine or abacavir/lamivudine with NAFLD were randomized 1:1 to switch from EFV to RAL (400 mg twice daily), maintaining nucleoside analogues unchanged, or to continue with EFV plus 2 nucleoside analogues. At baseline, eligible patients should show controlled attenuation parameter (CAP) values ≥238 dB/m. Changes in hepatic steatosis at 48 weeks of follow-up over baseline levels were measured by CAP.

Results

Overall, 39 patients were included, and 19 of them were randomized to switch to RAL. At week 48, median CAP for the RAL group was 250 (Q1-Q3, 221-277) dB/m and 286 (Q1-Q3, 269-314) dB/m for the EFV group (P = .035). The median decrease in CAP values was -20 (Q1-Q3, -67 to 15) dB/m for the RAL arm and 30 (Q1-Q3, -17 to 49) dB/m for the EFV group (P = .011). CAP values <238 dB/m at week 48 were observed in 9 (47%) patients on RAL and 3 (15%) individuals on EFV (P = .029).

Conclusions

After 48 weeks, HIV-infected individuals switching EFV to RAL showed decreases in the degree of hepatic steatosis, as measured by CAP, compared with those continuing with EFV. In addition, the proportion of patients without significant hepatic steatosis after 48 weeks was greater for those who switched to RAL.

Clinical Trials Registration

NCT01900015.

Scutellarin ameliorates nonalcoholic fatty liver disease through the PPARγ/PGC-1α-Nrf2 pathway

Nonalcoholic fatty liver disease (NAFLD) is characterised by excessive accumulation of hepatic lipids and oxidative injury of hepatocytes. Scutellarin is a flavonoid glycoside having antioxidative stress activity. Our current study aims to investigate the molecular mechanism of scutellarin ameliorating NAFLD. Scutellarin treatment was applied to male C57BL/6 mice maintained on a high-fat diet (HFD) and HepG2 cells challenged with oleic acid. The antioxidation biochemical indicators and lipid levels in the liver and cells were detected by kits. Liver pathology was observed by light microscope, Oil Red O staining, and transmission electron microscope (TEM). In addition, quantitative real-time polymerase chain reactions (qRT-PCR) and western blot assays were employed to detect the mRNA and protein levels of various antioxidative-related genes in the presence or absence of peroxisome proliferator-activated receptor gamma (PPARγ); inhibitor GW9662. Our results showed that scutellarin could significantly reduce blood lipid levels and enhance antioxidative capacities in both the models. In addition, scutellarin treatment conspicuously activated PPARγ, peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α), nuclear factor erythroid-2-related factor (Nrf2), haem oxygenase-1 (HO-1), glutathione S-transferase (GST), and NAD(P)H quinone dehydrogenase one (NQO1), while it significantly inhibited nuclear factor kappa B (NF-κB), Kelch-like ECH-associated protein 1 (Keap1) at both the mRNA and protein levels. However, after interfered by GW9662, scutellarin effect was significantly decreased. The experimental data demonstrated that scutellarin showed strong hypolipidaemic, antioxidative, and liver protective activity which could be attributed to its regulating activity in the PPARγ/PGC-1α-Nrf2 signaling pathway.

Non-alcoholic fatty liver disease phenotypes in patients with inflammatory bowel disease

Non-alcoholic fatty liver disease (NAFLD) can be detected in up to 33.6% of inflammatory bowel disease (IBD) patients, often in absence of metabolic risk factors. Nevertheless, most of previous studies on such issue were conducted within the IBD population only. The primary aim of this study was to compare clinical and metabolic features of NAFLD in patients with and without IBD (w/o IBD) and to identify specific NAFLD phenotypes within the IBD population. Among 223 NAFLD patients, 78 patients with IBD were younger compared to 145 without (w/o) IBD, were less likely to have altered liver enzymes, had lower mean body weight, smaller waist circumference and lower body mass index (BMI); at the same time, MetS was more prevalent among patients w/o IBD (56.6 vs. 23.1%, p < 0.001). Within IBD population, patients with severe IBD showed more often severe steatosis (S3) at ultrasound (US) (32.1 vs. 16.6%, p = 0.01), compared to mild-to-moderate disease. Independent risk factors for S3 US steatosis in IBD patients at the multivariate logistic regression analysis were: more than 1 IBD relapse per year during disease history (OR 17.3, 95% CI 3.6-84), surgery for IBD (OR 15.1, 95% CI 3.1-73.7) and more extensive intestinal involvement (OR 19.4, 95% CI 3.4-110.9); the ongoing anti-Tumor Necrosis Factor alpha (antiTNFα) therapy was the only independent factor which protect toward the presence of altered liver enzymes (OR 0.15, 95% CI 0-0.8, p = 0.02). In conclusion, NAFLD in IBD patients is different from that in patients w/o IBD, who seem to develop different NAFLD phenotypes according to intestinal disease clinical course. More severe IBD seem to predict the presence of more severe steatosis. Therapy with antiTNFα antibodies could prevent alteration of liver enzymes in such population.

Burden of Chronic Viral Hepatitis and Liver Cirrhosis in Brazil - the Brazilian Global Burden of Disease Study

INTRODUCTION AND AIM

Data on epidemiology of liver diseases in Brazil is scarce. This study aimed to estimate the burden of chronic viral hepatitis and liver cirrhosis in the country.

MATERIALS AND METHODS

The indicator used was disability-adjusted life year (DALY), a sum of years of life lost due to premature mortality (YLL) and years lived with disability (YLD). Liver cirrhosis was analyzed in etiologic categories and cirrhosis of viral origin was considered part of the burden of chronic hepatitis.

RESULTS

There were 57,380 DALYs (30.3 per 100,000 inhabitants) attributable to chronic hepatitis B and cirrhosis due to hepatitis B, with 41,262 DALYs in men. Most burden was caused by YLL (47,015 or 24.8/100,000) rather than YLD (10,365 or 5.5/100,000). Chronic hepatitis C and cirrhosis due to hepatitis C were responsible for 207,747 DALYs (109.6/100,000), of which 137,922 were YLL (72.7/100,000) and 69,825 (36.8/100,000) were YLD, with a higher proportion of DALYs in men (73.9%). Cirrhosis due to alcohol or other causes had a total of 536,169 DALYs (1,4% of total DALYs in Brazil), with 418,272 YLL (341,140 in men) and 117,897 YLD (97,965 in men). Highest DALYs' rates occurred at ages 60-69 in chronic hepatitis and at ages 45-59 in cirrhosis due to alcohol or other causes.

CONCLUSION

Chronic viral hepatitis and liver cirrhosis are responsible for a significant burden in Brazil, affecting mainly men and individuals still in their productive years. Most burden is related to non-viral causes of cirrhosis, with a major contribution of alcohol.

Dual role of protein tyrosine phosphatase 1B in the progression and reversion of non-alcoholic steatohepatitis

Objectives

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in Western countries. Protein tyrosine phosphatase 1B (PTP1B), a negative modulator of insulin and cytokine signaling, is a therapeutic target for type 2 diabetes and obesity. We investigated the impact of PTP1B deficiency during NAFLD, particularly in non-alcoholic steatohepatitis (NASH).

Methods

NASH features were evaluated in livers from wild-type (PTP1BWT) and PTP1B-deficient (PTP1BKO) mice fed methionine/choline-deficient diet (MCD) for 8 weeks. A recovery model was established by replacing MCD to chow diet (CHD) for 2–7 days. Non-parenchymal liver cells (NPCs) were analyzed by flow cytometry. Oval cells markers were measured in human and mouse livers with NASH, and in oval cells from PTP1BWT and PTP1BKO mice.

Results

PTP1BWT mice fed MCD for 8 weeks exhibited NASH, NPCs infiltration, and elevated Fgf21, Il6 and Il1b mRNAs. These parameters decreased after switching to CHD. PTP1B deficiency accelerated MCD-induced NASH. Conversely, after switching to CHD, PTP1BKO mice rapidly reverted NASH compared to PTP1BWT mice in parallel to the normalization of serum triglycerides (TG) levels. Among NPCs, a drop in cytotoxic natural killer T (NKT) subpopulation was detected in PTP1BKO livers during recovery, and in these conditions M2 macrophage markers were up-regulated. Oval cells markers (EpCAM and cytokeratin 19) significantly increased during NASH only in PTP1B-deficient livers. HGF-mediated signaling and proliferative capacity were enhanced in PTP1BKO oval cells. In NASH patients, oval cells markers were also elevated.

Conclusions

PTP1B elicits a dual role in NASH progression and reversion. Additionally, our results support a new role for PTP1B in oval cell proliferation during NAFLD.

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PTP1B deficiency accelerates MCD-induced NASH.

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The liver inflammatory responses during NASH are enhanced in PTP1B-deficient mice.

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PTP1B deficiency accelerates the reversion of NASH in a recovery dietary model.

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In a DCC model PTP1BKO livers increased oval cells markers and proliferative capacity.

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PTP1B deficiency enhances HGF-mediated signaling and proliferation of oval cells.

Comprehensive Study of Multiple Stages Progressing to Nonalcoholic Steatohepatitis with Subsequent Fibrosis in SD Rats

Because of the absence of the time course of histological nonalcoholic fatty hepatitis with subsequent fibrotic progression, the effective approaches available for controlling the onset and progression of non-alcoholic steatohepatitis (NASH) remain limited. Therefore, we detected the serum and liver tissue related lipid metabolism disorder, liver pathology and relative molecular makers alteration dynamically in a high fat-sucrose diet during different time points. High fat-sucrose diet significantly increased the serum lipid level on day 10. The excess lipid accumulation in liver was referred to as simple steatosis after the feeding of a high fat-sucrose diet for 20 days. The high fat-sucrose diet induced a hepatic inflammation response on day 30. Similarly, hepatic fibrosis was also initiated on day 30 and gradually formed from the 30th to the 50th day. Oxidative stress may be related with the process from NASH to liver fibrosis. Insulin resistance was involved in the progression from hepatic steatosis to NASH with hepatic fibrosis from the 20th to the 50th day. In conclusion, we established a high fat-sucrose diet induced nonalcoholic fatty hepatitis with liver fibrosis rat model, which presented the time course of histological nonalcoholic steatohepatitis and the initiation and progression change of characteristic molecular makers in the process from steatosis to hepatic fibrosis.

Mesozeaxanthin protects the liver and reduces cardio-metabolic risk factors in an insulin resistant rodent model

Background: Mesozeaxanthin (MZ) is a macular carotenoid which has been reported to have a number of pharmacological properties, including the antioxidant, and anticarcinogenic property, and has been stated to decrease the hepatocyte lipid content.

Objective: In this study, we investigated the effect of MZ on cardio-metabolic health risk (CMHR) and its probable mechanisms of action in rats fed a high-fat diet (HFD).

Design: Rats were randomly divided into four groups consisting of (i) Control, (ii) MZ, (iii) HFD, and (iv) HFD+MZ.

Results: MZ treatment increased the antioxidant enzyme activities and helped improve the liver function. The treatment alleviated CMHR and decreased the level of nuclear factor kappa B (NF-κB p65) and tumor necrosis factor-alpha (TNF-α). The levels of hepatic peroxisome proliferator-activated receptor gamma (PPAR-γ), phosphorylated insulin receptor substrate 1 (p-IRS-1), β,β-carotene 9’,10’-oxygenase 2 (BCO2) and nuclear factor erythroid 2-related factor 2 (Nrf2), which decrease in HFD rats, were found to be significantly higher in MZ supplemented animals.

Conclusion: MZ has antioxidant and anti-inflammatory properties and can is reported in this study toprotect against fatty liver and cardio-metabolic syndrome, possibly through regulation of PPAR-γ, IRS-1, Nrf2 and NF-κB proteins, in an insulin-resistant rodent model.

Hepatic anti-inflammatory effect of hexane extracts of Dioscorea batatas Decne: Possible suppression of toll-like receptor 4-mediated signaling

The hepatic anti-inflammatory potential of hexane extracts of Dioscorea batatas Decne edible part (EDH-1e) and bark (EDH-2b) were investigated in Western-type diet-fed apolipoprotein E null [ApoE (-/-)] mice and HepG2 cells. EDH-1e and EDH-2b suppressed the increased levels of tumor necrosis factor alpha (TNF-α), interleukin (IL)-6, transforming growth factor beta 1 (TGF-β1), vascular cell adhesion protein 1 (VCAM-1), and monocyte chemoattractant protein-1 (MCP-1), and reduced infiltration of monocytes into liver tissue. The protein levels of Toll-like receptor 4 (TLR4) were also downregulated by EDH-1e and EDH-2b treatment as were the levels of activator protein 1 (AP-1), c-fos, and c-jun in the livers from Western-type diet-fed ApoE (-/-) mice and in lipopolysaccharide-stimulated HepG2 cells. Taken together, EDH-1e and EDH-2b attenuated hepatic inflammation and fibrosis via suppression of the TLR4-AP1-mediated signaling pathway.

Hepatic Natural Killer T-cell and CD8+ T-cell Signatures in Mice with Nonalcoholic Steatohepatitis

Hepatic inflammation is a key pathological feature of Nonalcoholic Steatohepatitis (NASH). Natural Killer T-cells (NKT) and CD8+ T-cells are known to play an important role in obesity related adipose tissue inflammation. We hypothesized that these same inflammatory phenotypes would be present in progressive NASH. We used a previously established high fat high carbohydrate (HFHC) murine obesogenic diet model of progressive NASH to investigate the role of NKT cells and CD8+ T-cells in C57Bl6/J mice. Further, to better understand the impact of these cell populations; CD1d-deficient and CD8+ T-cell depleted mice were subjected to HFHC diet for 16 weeks. C57Bl6/J mice fed HFHC diet had increased body weight, liver triglyceride content, serum alanine aminotransferase (ALT) levels and increased NKT cells and CD8+ T-cells infiltration in the liver. In addition human liver sections from patients with NASH showed increased CD8+ T-cells. In comparison, CD1d-deficient and CD8-T cell depleted mice fed HFHC had lower hepatic triglyceride content, lower ALT levels, as well reduced α-smooth muscle actin (αSMA), collagen type 1 alpha 1 (Col1a1), collagen type 1 alpha 2 (Col1a2) mRNA expression, lower activated resident macrophages and infiltrating macrophages and improved NAFLD activity scores. Further, while CD1d-deficient mice were protected against weight gain on the HFHC diet, CD8 T-cell depleted mice gained weight on the HFHC diet.

Conclusion

We found that NASH has an immunological signature that includes hepatic infiltrating NKT and CD8+ T-Cells. Depletion of these cells resulted in reduced NASH progression and thus presents novel therapeutic avenues for the treatment of NASH.

Treatment of Obesity: Weight Loss and Bariatric Surgery

This review focuses on the mechanisms underlying, and indications for, bariatric surgery in the reduction of cardiovascular disease (CVD), as well as other expected benefits of this intervention. The fundamental basis for bariatric surgery for the purpose of accomplishing weight loss is the determination that severe obesity is a disease associated with multiple adverse effects on health, which can be reversed or improved by successful weight loss in patients who have been unable to sustain weight loss by nonsurgical means. An explanation of possible indications for weight loss surgery as well as specific bariatric surgical procedures is presented, along with review of the safety literature of such procedures. Procedures that are less invasive or those that involve less gastrointestinal rearrangement accomplish considerably less weight loss but have substantially lower perioperative and longer-term risk. The ultimate benefit of weight reduction relates to the reduction of the comorbidities, quality of life, and all-cause mortality. With weight loss being the underlying justification for bariatric surgery in ameliorating CVD risk, current evidence-based research is discussed concerning body fat distribution, dyslipidemia, hypertension, diabetes mellitus, inflammation, obstructive sleep apnea, and others. The rationale for bariatric surgery reducing CVD events is discussed and juxtaposed with impacts on all-cause mortalities. Given the improvement of established obesity-related CVD risk factors after weight loss, it is reasonable to expect a reduction of CVD events and related mortality after weight loss in populations with obesity. The quality of the current evidence is reviewed, and future research opportunities and summaries are stated.

Effect of hepatic steatosis on the progression of chronic hepatitis B: A prospective cohort and in vitro study

Aim

To characterize the effect of hepatic steatosis (HS) on the progression of chronic hepatitis B.

Methods

A total of 162 chronic hepatitis B (CHB) patients confirmed by liver biopsy were involved in this study. All subjects were prospectively followed-up for 5 years in real-life clinical practice. Fibrosis stage was determined using aspartate aminotransferase-to-platelet ratio index (APRI). The end-point was cirrhosis, liver cancer or death. The effects of steatosis on the biological behavior of hepatocellular carcinoma cells were investigated using oleic acid-induced lipid accumulation in HepG₂, HLE, PLC, and SMMC-7721 cells.

Results

Mean age, body mass index, and serum cholesterol were significantly higher in CHB patients with HS than those without HS at baseline (p< 0.05). The APRI was lower in patients without HS at baseline (p<0.05). Compared to patients with HS, APRI of patients without HS decreased significantly during the follow-up period (p<0.05). The 5-year cumulative incidence of cirrhosis were 4.17% and 5.19% in patients without and with HS, respectively (p>0.05). The multivariate analysis showed that older (RR 1.07, 95% CI 0.996-1.149, p = 0.065) and S3 stage of liver fibrosis (RR 3.50, 95% CI 0.812–15.117, p=0.093) were risk factors for the progression to cirrhosis. In vitro, cell steatosis promoted proliferation and migration of HCC cells and conferred cell cycle at S phase.

Conclusion

The older and S3 stage of fibrosis may be risk factors for progression to cirrhosis in CHB patients with HS. HS may aggravate liver disease, promoting HCC progression.

Deficiency of CKIP-1 aggravates high-fat diet-induced fatty liver in mice

Casein kinase 2 interacting protein-1(CKIP-1) is widely expressed in a variety of tissues and cells, and plays an important role in various critical cellular and physiological processes including cell growth, apoptosis, differentiation, cytoskeleton and bone formation. Here, we found: (1) CKIP-1 deficient mice exhibited increased body weight, liver weight, number and size of lipid droplets, and TG content comparing with WT mice after being exposed to high fat diet (HFD); (2) the levels of serum insulin, liver glycogen, phosphorylated C-Jun-N-terminal kinase-1 (pJNK1) and phosphorylated insulin receptor substrate -1(pIRS1) in CKIP-1^-/- mice were higher than those of WT mice; (3) CKIP-1 interacted with JNK1 in vitro. Our results indicate that CKIP-1 deficiency in mice aggravates HFD-induced fatty liver by upregulating JNK1 phosphorylation and further upregulating IRS-1 phosphorylation and RI.