A concise review of non-alcoholic fatty liver disease. Atherosclerosis. 2015;239:192-202. [PMID: 25617860 DOI: 10.1016/j.atherosclerosis.2015.01.001]

Association of fatty liver index with the risk of incident cardiovascular disease and acute myocardial infarction

BACKGROUND

Fatty liver disease (FLD) has been identified as constituting cardiometabolic risk. However, evidence on the association of fatty liver index (FLI) with cardiovascular disease (CVD) is largely cross-sectional, with limited evidence on the predictability of incident CVD, and specifically, acute myocardial infarction (AMI). Therefore, we aimed to investigate the prospective associations between fatty liver as estimated by FLI and incident CVD, and specifically AMI, in the Kuopio Ischaemic Heart Disease Risk Factor Study cohort.

PATIENTS AND METHODS

Our patients were 1205 middle-aged men free of CVD at baseline. The associations of baseline FLI with incident CVD and incident AMI were analyzed using multivariable-adjusted Cox regression models.

RESULTS

During a median follow-up of 17 years, a total of 690 incident cases of CVD and 269 cases of AMI were recorded through Finnish registries. For incident CVD, for the high (FLI≥60) versus the low (≤30) FLI category, the hazard ratio (HR) was 1.77 [95% confidence interval (CI): 1.46-2.14] in the minimally adjusted model. With increasing adjustment, the association was attenuated progressively. In the most adjusted model, the HR was 1.41 (95% CI: 1.10-1.79). For incident AMI, for the high FLI category, the HR was 1.65 (95% CI: 1.22-2.23) in the minimally adjusted model, but in most comprehensive models when we included metabolic factors, the HR was not significant (HR=1.136, 95% CI: 0.777-1.662).

CONCLUSION

FLI can predict incident CVD. However, the predictability of AMI using FLI is subject to interactions of metabolic factors. Individuals with FLI in the moderate to high category should be evaluated and monitored for subclinical or overt cardiovascular (including coronary) disease.

Role of cAMP and phosphodiesterase signaling in liver health and disease

Liver disease is a significant health problem worldwide with mortality reaching around 2 million deaths a year. Non-alcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD) are the major causes of chronic liver disease. Pathologically, NAFLD and ALD share similar patterns of hepatic disorders ranging from simple steatosis to steatohepatitis, fibrosis and cirrhosis. It is becoming increasingly important to identify new pharmacological targets, given that there is no FDA-approved therapy yet for either NAFLD or ALD. Since the evolution of liver diseases is a multifactorial process, several mechanisms involving parenchymal and non-parenchymal hepatic cells contribute to the initiation and progression of liver pathologies. Moreover, certain protective molecular pathways become repressed during liver injury including signaling pathways such as the cyclic adenosine monophosphate (cAMP) pathway. cAMP, a key second messenger molecule, regulates various cellular functions including lipid metabolism, inflammation, cell differentiation and injury by affecting gene/protein expression and function. This review addresses the current understanding of the role of cAMP metabolism and consequent cAMP signaling pathway(s) in the context of liver health and disease. The cAMP pathway is extremely sophisticated and complex with specific cellular functions dictated by numerous factors such abundance, localization and degradation by phosphodiesterases (PDEs). Furthermore, because of the distinct yet divergent roles of both of its effector molecules, the cAMP pathway is extensively targeted in liver injury to modify its role from physiological to therapeutic, depending on the hepatic condition. This review also examines the behavior of the cAMP-dependent pathway in NAFLD, ALD and in other liver diseases and focuses on PDE inhibition as an excellent therapeutic target in these conditions.

Flavonones from Penthorum chinense Ameliorate Hepatic Steatosis by Activating the SIRT1/AMPK Pathway in HepG2 Cells

Pinocembrin-7-O-β-d-glucoside (PCBG), pinocembrin (PCB), and 5-methoxy-pinocembrin-7-O-β-d-glucoside (MPG) are three flavonones isolated from Penthorum chinense Pursh (P. chinense). The effects of the three flavonones on hepatic steatosis and their molecular mechanisms in HepG2 cells were investigated in this study for the first time. A model of hepatic steatosis in HepG2 cells was induced by free fatty acid (FFA), and co-treated with the three flavonones as mentioned. Intracellular lipid droplets were detected by Oil Red O staining. PCB, PCBG, and MPG suppressed oxidative stress by decreasing malondialdehyde (MDA) levels and increasing superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities. The levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were ameliorated. Moreover, these flavonones enhanced the phosphorylation of AMP-activated protein kinase (AMPK) and the expression of silent mating type information regulation 2 homolog 1 (SIRT1) and peroxisome proliferator-activated receptor α (PPARα), and reduced the expression of sterol regulatory element binding protein-1c (SREBP1c) and the downstream targets fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC), and stearoyl-CoA desaturase 1 (SCD1). Molecular docking was used to predict the interaction and combination patterns between the three flavonones and the enzymes above. The results revealed that the SIRT1/AMPK pathway is involved in the functions of the three flavonones, and the most effective flavonone against hepatic steatosis might be PCBG, followed by MPG and PCB. Therefore, the three flavonones from P. chinense were found to exert preventive effects against hepatic steatosis by regulating the SIRT1/AMPK pathway.

Cognitive assessment of patients with nonalcoholic fatty liver disease

OBJECTIVE

The aim of this study was to investigate cognitive performance for the first time in participants with nonalcoholic fatty liver disease (NAFLD) using the Montreal Cognitive Assessment (MoCA).

PARTICIPANTS AND METHODS

In total, 70 participants with NAFLD and 73 age-matched and sex-matched healthy participants were enrolled in this prospective cross-sectional study. The diagnosis of NAFLD was made on the basis of abdominal ultrasonography findings. Anthropometric indices were calculated, and routine laboratory analyses were carried out for each participant. All participants provided sociodemographic data and completed the Beck Depression Inventory-II. Cognitive functions were evaluated using the Turkish version of the MoCA, with a cut-off score for mild cognitive impairment of less than 21 points.

RESULTS

The MoCA scores were significantly lower in participants with NAFLD than in the healthy group (P<0.05). In addition, more NAFLD participants than healthy participants presented with deficits in the visuospatial (P<0.05) and executive function domains (P<0.05). In the multivariate model, education level [2.79 (1.12-6.96); P<0.05] and area of residence [5.68 (2.24-14.38); P<0.001] were associated independently with cognitive dysfunction in both the NAFLD and the healthy groups. The MoCA scores were correlated negatively with fibrosis 4 scores in NAFLD participants (r=-0.359; P<0.05). However, hepatosteatosis grade and the presence of metabolic syndrome were not correlated with MoCA scores in the NAFLD group (P>0.05).

CONCLUSION

Our results show that NAFLD patients may have early or subtle cognitive dysfunction, including in the visuospatial and executive function domains, as indexed by scores on the MoCA test. Further targeted psychometric testing will be required to confirm the presence of cognitive impairment in this population.

Peroxiredoxin 5 regulates adipogenesis-attenuating oxidative stress in obese mouse models induced by a high-fat diet

Elevated levels of reactive oxygen species (ROS) are a hallmark of obesity. Peroxiredoxin 5 (Prx5), which is a cysteine-dependent peroxidase enzyme, has an intensive ROS scavenging activity because it is located in the cytosol and mitochondria. Therefore, we focused on the role of Prx5 in regulating mitochondrial ROS and adipogenesis. We demonstrated that Prx5 expression was upregulated during adipogenesis and Prx5 overexpression suppressed adipogenesis by regulating cytosolic and mitochondrial ROS generation. Silencing Prx5 promoted preadipocytes to differentiate into adipocytes accumulating lipids by activating adipogenic protein expression. Prx5-deletion mice fed on a high-fat diet (HFD) exhibited significant increase in body weight, enormous fat pads, and adipocyte hypertrophy in comparison to wild type mice. Prx5 deletion also remarkably induced adipogenesis-related gene expression in white adipose tissue. These phenotypic changes in Prx5-deletion mice were accompanied with lipid metabolic disorders, such as excessive lipid accumulation in the liver, severe hepatic steatosis, and high levels of triglyceride in the serum. These results demonstrated that Prx5 deletion increased the susceptibility to HFD-induced obesity and several of its associated metabolic disorders. In conclusion, we suggest that Prx5 inhibits adipogenesis by modulating ROS generation and adipogenic gene expression, implying that Prx5 may serve as a potential strategy to prevent and treat obesity.

Improved cardiometabolic risk factors in Japanese patients with type 2 diabetes treated with ipragliflozin: a pooled analysis of six randomized, placebo-controlled trials

To examine differential improvements among cardiovascular risk factors in response to treatment with ipragliflozin in Japanese type 2 diabetes mellitus (T2DM) patients, we conducted a pooled analysis of six randomized, double-blind trials of Japanese T2DM patients who received ipragliflozin 50 mg/day or placebo and had patient-level data for cardiometabolic risk parameters. Risk factors included glycated hemoglobin (HbA1c), body weight, homeostatic model assessment for insulin resistance and beta-cell function (HOMA-R and HOMA-beta, respectively), systolic blood pressure, fasting serum insulin concentrations, and the concentration of uric acid, lipids, and liver enzymes from baseline to end of treatment (EOT; 12-24 weeks). The primary endpoint of each trial was the change in HbA1c from baseline to EOT. Changes in risk factors from baseline to EOT were compared between ipragliflozin-treated and placebo groups, and between two subgroups (high- and low-risk groups for each parameter). All parameters, except low-density lipoprotein cholesterol (LDL-C) and non high-density lipoprotein cholesterol (non HDL-C), improved significantly in the ipragliflozin group. Subgroup analysis revealed a significantly greater improvement in the high-risk group versus low-risk group in HbA1c, HOMA-R, HOMA-beta, aspartate transaminase, alanine transaminase, and gamma-glutamyltransferase, but not in any of the lipid parameters or blood pressure. Liver function improvement in the ipragliflozin group was significantly correlated with changes in body weight, HbA1c, HOMA-beta, and HOMA-R. This analysis demonstrated that, in Japanese T2DM patients, ipragliflozin 50 mg/day was associated with improvements in cardiometabolic risk factors, except for LDL-C and non HDL-C.

Editor's Highlight: PCB126 Exposure Increases Risk for Peripheral Vascular Diseases in a Liver Injury Mouse Model

The liver is vital for xenobiotic and endobiotic metabolism. Previously, we demonstrated that a compromised liver worsened toxicity associated with exposure to polychlorinated biphenyls (PCBs), through disruption of energy homeostasis. However, the role of a compromised liver in defining dioxin-like PCB126 toxicity on the peripheral vasculature and associated inflammatory diseases is yet to be studied. This study investigated the effects of PCB126 on vascular inflammation linked to hepatic dysfunction utilizing a liver injury mouse model. Male C57Bl/6 mice were fed either an amino acid control diet (CD) or a methionine-choline deficient (MCD) diet in this 14-week study. Mice were exposed to PCB126 (0.5 mg/kg) and analyzed for inflammatory, calorimetric and metabolic parameters. MCD diet-fed mice demonstrated steatosis, indicative of a compromised liver. Mice fed the MCD-diet and subsequently exposed to PCB126 manifested lower body fat mass, increased liver to body weight ratio and alterations in hepatic gene expression related to lipid and carbohydrate metabolism, implicating metabolic disturbances. PCB126-induced steatosis irrespective of the diet type, but only the MCD + PCB126 group exhibited steatohepatitis and fibrosis. Furthermore, PCB126 exposure in MCD-fed mice led to increased plasma inflammatory markers such as Icam-1, plasminogen activator inhibitor-1 and proatherogenic trimethylamine-N-oxide, suggesting inflammation of the peripheral vasculature that is characteristic of atherosclerosis. Taken together, our data provide new evidence of a link between a compromised liver, PCB-mediated hepatic inflammation and vascular inflammatory markers, suggesting that environmental pollutants can promote crosstalk between different organ systems, leading to inflammatory disease pathologies.

Adipose tissue macrophages induce hepatic neutrophil recruitment and macrophage accumulation in mice

OBJECTIVE

Obesity is a risk factor for non-alcoholic steatohepatitis (NASH). This risk has been attributed to visceral adipose tissue (vAT) expansion associated with increased proinflammatory mediators. Accumulation of CD11c⁺ proinflammatory adipose tissue macrophages (ATM) is an important driver of vAT inflammation. We investigated the role of ATMs in hepatic inflammation during NASH development.

DESIGN

vAT isolated from lean, obese or ATM-depleted (using clodronate liposomes) obese mice was transplanted to lean ldlr^-/- acceptor mice. Systemic and hepatic inflammation was assessed either after 2 weeks on standard chow or after 8 weeks on high cholesterol diet (HCD) to induce NASH.

RESULTS

Transplanting donor vAT from obese mice increased HCD-induced hepatic macrophage content compared with lean-transplanted mice, worsening liver damage. ATM depletion prior to vAT transplantation reduced this increased hepatic macrophage accumulation. On chow, vAT transplantation induced a more pronounced increase in circulating and hepatic neutrophil numbers in obese-transplanted than lean-transplanted mice, while ATM depletion prior to vAT transplantation reversed this effect. Microarray analysis of fluorescence-activated cell sorting of CD11c⁺ and CD11c^- macrophages isolated from donor adipose tissue showed that obesity resulted in enhanced expression of neutrophil chemotaxis genes specifically in CD11c⁺ ATMs. Involvement of the neutrophil chemotaxis proteins, CXCL14 and CXCL16, was confirmed by culturing vAT. In humans, CD11c expression in vAT of obese individuals correlated with vAT expression of neutrophil chemotactic genes and with hepatic expression of neutrophil and macrophage marker genes.

CONCLUSION

ATMs from obese vAT induce hepatic macrophage accumulation during NASH development, possibly by enhancing neutrophil recruitment.

Quantitative MRI evaluation of whole abdomen adipose tissue volumes in healthy volunteers-validation of technique and implications for clinical studies

OBJECTIVE

To explore "whole abdomen" MRI methods for quantifying adipose tissue volumes and to establish associations with body mass index (BMI) and measurement reproducibility-relative to existing "partial abdomen" methods.

METHODS

15 healthy volunteers were scanned on a 3T MRI scanner using a double-echo three-point-Dixon gradient echo sequence. Whole abdomen volumes were acquired via three separate scans ("supine 1", "supine 2" and "prone"). Segmentation was applied to derive (i) "whole abdomen" visceral (VAT) and subcutaneous adipose tissue (SCAT) volumes, and (ii) "partial abdomen" volumes at the lumbar spine (L3 to L5). Root-mean-square coefficients of variation (RMS CoV) were calculated to quantify the variability of each measurement.

RESULTS

"Whole abdomen" measurements were found to correlate better with BMI (r2max = 0.74) than "partial abdomen" volumes (r2max = 0.66). Total adipose tissue (TAT) measurements correlated better with BMI (r2max = 0.74) than SCAT (r2max = 0.43) or VAT (r2max = 0.33) for both methods. Scan-to-scan RMS CoV's for "whole abdomen" VAT and SCAT measurements were 4.16 and 3.61% compared to 6.31 and 5.07% for "partial abdomen" measurements.

CONCLUSION

"Whole abdomen" measures of abdominal adiposity are better correlated with BMI and demonstrate better scan-to-scan reproducibility than "partial abdomen" measures. It is recommended that "whole abdomen" measures be used in longitudinal MRI radiology investigations, where small volume changes may occur. Advances in knowledge: Whole abdomen adipose tissue volumes can be measured and quantified using commercial MRI sequences and post-processing software. These methods are better correlated with BMI and are more reproducible than partial abdomen measures.

Mortality disparities: A comparison with the Haudenosaunee in New York State

Identifying health status and disparities for Indigenous populations is the first logical step toward better health. We compare the mortality profile of the American Indian and Alaska Native (AI/AN) population with that of non-Hispanic whites in the Haudenosaunee Nations in New York State, the Indian Health Service (IHS) East region (Nashville Area) and the United States. Data from the linkage of IHS registration records with decedents from the National Death Index (1990-2009) were used to identify AI/AN deaths misclassified as non-AI/AN. Analyses were limited to persons of non-Hispanic origin. We analyzed trends for 1990-2009 and compared AI/AN and white persons in the Haudenosaunee Nations in New York State, IHS East region and the United States. All-cause death rates over the past two decades for Haudenosaunee men declined at a greater percentage per year than for AI/AN men in the East region and United States. This decrease was not observed for Haudenosaunee women with all-cause death rates appearing to be stable over the past two decades. Haudenosaunee all-cause death rates were 16% greater than that for whites in the Haudenosaunee Nations. The most prominent disparities between Haudenosaunee and whites are concentrated in the 25-44 year age group (Risk Ratio=1.85). Chronic liver disease, diabetes, unintentional injury, and kidney disease death rates were higher in Haudenosaunee than in whites in the Haudenosaunee Nations. The Haudenosaunee cancer death rate (180.8 per 100,000) was higher than that reported for AI/AN in the East (161.5 per 100,000).Haudenosaunee experienced higher rates for the majority of the leading causes of death than East AI/AN. These results highlight the importance of Haudenosaunee-specific data to target prevention efforts to address health disparities and inequalities in health.

The Role of the Gut Microbiome in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease, with prevalence increasing in parallel with the rising incidence in obesity. Believed to be a "multiple-hit" disease, several factors contribute to NAFLD initiation and progression. Of these, the gut microbiome is gaining interest as a significant factor in NAFLD prevalence. In this paper, we provide an in-depth review of the progression of NAFLD, discussing the mechanistic modes of hepatocyte injury and the potential role for manipulation of the gut microbiome as a therapeutic strategy in the prevention and treatment of NAFLD.

Restricted feeding for 9h in the active period partially abrogates the detrimental metabolic effects of a Western diet with liquid sugar consumption in mice

BACKGROUND

Obesity is a major public health concern that can result from diets high in fat and sugar, including sugar sweetened beverages. A proposed treatment for dietary-induced obesity is time-restricted feeding (TRF), which restricts consumption of food to specific times of the 24-hour cycle. Although TRF shows great promise to prevent obesity and the development of chronic disease, the effects of TRF to reverse metabolic changes and the development of NAFLD in animal models of a Western diet with sugary water consumption is not known.

OBJECTIVE

The objective of the current study was to evaluate the role of TRF in the treatment of obesity and NAFLD through examination of changes in metabolic and histopathologic parameters.

METHODS

To better understand the role of TRF in the treatment of obesity and NAFLD, we investigated the metabolic phenotype and NAFLD parameters in a mouse model of NAFLD in which obesity and liver steatosis are induced by a Western Diet (WD): a high-fat diet of lard, milkfat and Crisco with sugary drinking water. Mice were subjected to a short-term (4-weeks) and long-term (10-weeks) TRF in which food was restricted to 9h at night.

RESULTS

Prior to TRF treatment, the WD mice had increased body mass, and exhibited less activity, and higher average daytime energy expenditure (EE) than chow fed mice. Approximately 4- and 10-weeks following TFR treatment, WD-TRF had moderate but not statistically significant weight loss compared to WD-ad libitum (WD-AL) mice. There was a modest but significant reduction in the inguinal adipose tissue weight in both WD-TRF groups compared to the WD-AL groups; however, there was no difference in epididymal and retroperitoneal adipose tissue mass or adipocyte size distribution. In contrast, the diet-induced increase in normalized liver tissue weight, hepatic triglyceride, and NAFLD score was partially abrogated in the 4-week WD-TRF mice, while systemic insulin resistance was partially abrogated and glucose intolerance was completely abrogated in the 10-week WD-TRF mice. Importantly, WD-induced metabolic dysfunction (substrate utilization, energy expenditure, and activity) was partially abrogated by 4- and 10-week TRF.

CONCLUSIONS

Our results support the hypothesis that TRF aids in reducing the detrimental metabolic effects of consuming a WD with sugary drinking water but does not ameliorate obesity.

Mice lacking have reduced signs of metabolic syndrome and non-alcoholic fatty liver disease

Metabolic syndrome (MetS) is a term used to characterize individuals having at least three of the following diseases: obesity, dyslipidemia, hyperglycemia, insulin resistance, hypertension, and nonalcoholic fatty liver disease (NAFLD). It is widespread, and the number of individuals with MetS is increasing. However, the events leading to the manifestation of MetS are not well-understood. Here, we show that loss of murine ARV1 (mARV1) results in resistance to acquiring diseases associated with MetS. Arv1^-/- animals fed a high-fat diet were resistant to diet-induced obesity, had lower blood cholesterol and triglyceride levels, and retained glucose tolerance and insulin sensitivity. Livers showed no gross morphological changes, contained lower levels of cholesterol, triglycerides, and fatty acids, and showed fewer signs of NAFLD. Knockout animals had elevated levels of liver farnesol X receptor (FXR) protein and its target, small heterodimer protein (SHP). They also had decreased levels of CYP7α1, CYP8β1, and mature SREBP1 protein, evidence suggesting that liver FXR signaling was activated. Strengthening this hypothesis was the fact that peroxisome proliferator-activating receptor α (PPARα) protein was elevated, along with its target, fibroblast growth factor 21 (FGF21). Arv1^-/- animals excreted more fecal cholesterol, free fatty acids, and bile acids. Their small intestines had 1) changes in bile acid composition, 2) an increase in the level of the intestinal FXR antagonist, tauromuricholic acid, and 3) showed signs of attenuated FXR signaling. Overall, we believe that ARV1 function is deleterious when consuming a high-fat diet. We further hypothesize that ARV1 is critical for initiating events required for the progression of diseases associated with MetS and NAFLD.

Disruptions in gut microbial-host co-metabolism and the development of metabolic disorders

The microbial-mammalian metabolic axis has become recognized as an important component governing the overall homeostatic balance of the mammalian host. Disruption of the state of homeostasis among the gut microbiota has been shown to be causally linked to the development of host metabolic diseases including obesity, cardiovascular, diabetes, and fatty liver disease. This disruption is often referred to as gut dysbiosis. Gut dysbiosis leads to altered metabolic products derived from the microbiota and these in turn, typically shift the homeostatic metabolic balance of the host towards a low-grade chronic inflammation, a hallmark of metabolic syndrome. The primary objective of this review is to examine and discuss some very current research that has been done to study the effect of bacterial metabolites on host metabolism, sometimes referred to as microbiota-host co-metabolism. The metabolic conditions reviewed here include obesity, a known risk factor for all of the other metabolic conditions, as well as, cardiovascular disease, diabetes and nonalcoholic fatty liver disease. Only by further understanding the cause and result of gut dysbiosis will an adequate solution be found for metabolic disease, a viewpoint shared by many.

Consensus document. Management of non-alcoholic fatty liver disease (NAFLD). Clinical practice guideline

Non-alcoholic fatty liver disease (NAFLD) is the main cause of liver diseases in Spain and the incidence is raising due to the outbreak of type 2 diabetes and obesity. This CPG suggests recommendation about diagnosis, mainly non-invasive biomarkers, and clinical management of this entity. Life-style modifications to achieve weight loss is the main target in the management of NAFLD. Low caloric Mediterranean diet and 200 minutes/week of aerobic exercise are encouraged. In non-responders patients with morbid obesity, bariatric surgery or metabolic endoscopy could be indicated. Pharmacological therapy is indicated in patients with NASH and fibrosis and non-responders to weight loss measures. NAFLD could influence liver transplantation, as a growing indication, the impact of steatosis in the graft viability, de novo NAFLD rate after OLT and a raised cardiovascular risk that modify the management of this entity. The current CPG was the result of the First Spanish NAFLD meeting in Seville.

Spatial Systems Lipidomics Reveals Nonalcoholic Fatty Liver Disease Heterogeneity

Hepatocellular lipid accumulation characterizes nonalcoholic fatty liver disease (NAFLD). However, the types of lipids associated with disease progression are debated, as is the impact of their localization. Traditional lipidomics analysis using liver homogenates or plasma dilutes and averages lipid concentrations, and does not provide spatial information about lipid distribution. We aimed to characterize the distribution of specific lipid species related to NAFLD severity by performing label-free molecular analysis by mass spectrometry imaging (MSI). Fresh frozen liver biopsies from obese subjects undergoing bariatric surgery (n = 23) with various degrees of NAFLD were cryosectioned and analyzed by matrix-assisted laser desorption/ionization (MALDI)-MSI. Molecular identification was verified by tandem MS. Tissue sections were histopathologically stained, annotated according to the Kleiner classification, and coregistered with the MSI data set. Lipid pathway analysis was performed and linked to local proteome networks. Spatially resolved lipid profiles showed pronounced differences between nonsteatotic and steatotic tissues. Lipid identification and network analyses revealed phosphatidylinositols and arachidonic acid metabolism in nonsteatotic regions, whereas low–density lipoprotein (LDL) and very low–density lipoprotein (VLDL) metabolism was associated with steatotic tissue. Supervised and unsupervised discriminant analysis using lipid based classifiers outperformed simulated analysis of liver tissue homogenates in predicting steatosis severity. We conclude that lipid composition of steatotic and nonsteatotic tissue is highly distinct, implying that spatial context is important for understanding the mechanisms of lipid accumulation in NAFLD. MSI combined with principal component–linear discriminant analysis linking lipid and protein pathways represents a novel tool enabling detailed, comprehensive studies of the heterogeneity of NAFLD.

The Science of Obesity Management: An Endocrine Society Scientific Statement

The prevalence of obesity, measured by body mass index, has risen to unacceptable levels in both men and women in the United States and worldwide with resultant hazardous health implications. Genetic, environmental, and behavioral factors influence the development of obesity, and both the general public and health professionals stigmatize those who suffer from the disease. Obesity is associated with and contributes to a shortened life span, type 2 diabetes mellitus, cardiovascular disease, some cancers, kidney disease, obstructive sleep apnea, gout, osteoarthritis, and hepatobiliary disease, among others. Weight loss reduces all of these diseases in a dose-related manner-the more weight lost, the better the outcome. The phenotype of "medically healthy obesity" appears to be a transient state that progresses over time to an unhealthy phenotype, especially in children and adolescents. Weight loss is best achieved by reducing energy intake and increasing energy expenditure. Programs that are effective for weight loss include peer-reviewed and approved lifestyle modification programs, diets, commercial weight-loss programs, exercise programs, medications, and surgery. Over-the-counter herbal preparations that some patients use to treat obesity have limited, if any, data documenting their efficacy or safety, and there are few regulatory requirements. Weight regain is expected in all patients, especially when treatment is discontinued. When making treatment decisions, clinicians should consider body fat distribution and individual health risks in addition to body mass index.

The Eeffect of Metformin Combined with Calcium-Vitamin D3 Against Diet-Induced Nonalcoholic Fatty Liver Disease

Purpose: Metformin is one of the most popular drugs tested against nonalcoholic fatty liver disease (NAFLD). The present study aimed to investigate whether calcium-vitamin D₃ cosupplementation will intensify the effect of metformin on the prevention of high-fat, high-fructose (HFFr) diet-induced hepatic steatosis.

Methods: Male wistar rats (210±16 g) were assigned into the following seven groups: a Control group to receive a standard chow and six HFFr-fed groups to receive diets containing either normal (0.5% calcium and 1000 IU/kg vitamin D₃) or high amount of calcium and vitamin D₃ (2.4% calcium and 10000 IU/kg vitamin D₃) (CaD), in combination with gastric gavage administration of either saline or 25 or 200 mg/kg body weight/day metformin. After 60 days, rats were assessed with respect to their anthropometric, metabolic and hepatic parameters, as well as their hepatic AMP-activated protein kinase (AMPK) phosphorylation.

Results: Metformin and CaD, either alone or in combination, caused a significant reduction in HFFr diet-induced high serum aspartate aminotransferase (AST), hepatic steatosis and lipid accumulation without effect on insulin resistance and AMPK phosphorylation. In addition, slightly (and non-significantly) better effects of the combination in ameliorating steatosis and hepatic cholesterol content were observed.

Conclusion: Taken together, our results suggest that metformin and CaD could protect against the onset of HFFr diet-induced NAFLD in an insulin and AMPK-independent manner, without any marked additional benefits of their combination.

Genetic variants in COL13A1, ADIPOQ and SAMM50, in addition to the PNPLA3 gene, confer susceptibility to elevated transaminase levels in an admixed Mexican population

Non-alcoholic fatty liver disease (NAFLD) is the accumulation of extra fat in liver cells not caused by alcohol. Elevated transaminase levels are common indicators of liver disease, including NAFLD. Previously, we demonstrated that PNPLA3 (rs738409), LYPLAL1 (rs12137855), PPP1R3B (rs4240624), and GCKR (rs780094) are associated with elevated transaminase levels in overweight/obese Mexican adults. We investigated the association between 288 SNPs identified in genome-wide association studies and risk of elevated transaminase levels in an admixed Mexican-Mestizo sample of 178 cases of NAFLD and 454 healthy controls. The rs2896019, rs12483959, and rs3810622 SNPs in PNPLA3 and rs1227756 in COL13A1 were associated with elevated alanine aminotransferase (ALT, ≥40IU/L). A polygenic risk score (PRS) based on six SNPs in the ADIPOQ, COL13A1, PNPLA3, and SAMM50 genes was also associated with elevated ALT. Individuals carrying 9-12 risk alleles had 65.8% and 48.5% higher ALT and aspartate aminotransferase (AST) levels, respectively, than those with 1-4 risk alleles. The PRS showed the greatest risk of elevated ALT levels, with a higher level of significance than the individual variants. Our findings suggest a significant association between variants in COL13A1, ADIPOQ, SAMM50, and PNPLA3, and risk of NAFLD/elevated transaminase levels in Mexican adults with an admixed ancestry. This is the first study to examine high-density single nucleotide screening for genetic variations in a Mexican-Mestizo population. The extent of the effect of these variations on the development and progression of NAFLD in Latino populations requires further analysis.

Role of Inflammasomes in the Development of Gastrointestinal Diseases

Many diseases of the gastrointestinal tract have been attributed to chronic inflammation, and a few have identified the role of inflammasomes in their pathogenesis. Inflammasomes are a group of protein complexes comprising of several intracellular proteins that link the sensing of microbial products and metabolic stress to the proteolytic activation of the proinflammatory cytokines. Recent studies have implicated activation of several families of NOD-like receptors (NLRs) which are major components of inflammasomes in the development and exacerbation of many diseases of human systems. In this chapter, we discuss the role of inflammasomes in some of the most prevalent diseases of the gastrointestinal tract and highlight potential targets for treatment.

Impact of Severe Obesity on Cardiovascular Risk Factors in Youth

OBJECTIVE

To compare cardiovascular risk factor clustering (CVRFC) in severely obese youth with those with lower degrees of obesity.

STUDY DESIGN

We divided a childhood obesity clinic derived cohort into the degrees of obesity (class I, II, and III) and added a "class IV" category corresponding to >160% of the 95th centile of body mass index (BMI) for age and sex. In a cross-sectional analysis, we investigated the presence of CVRFC in 2244 participants; in 621 who were followed longitudinally, we investigated the determinants of endpoint CVRFC.

RESULTS

Class IV obesity was associated with increased risk for CVRFC compared with overweight (OR = 17.26, P < .001) at a similar magnitude to class III obesity (OR = 17.26, P < .001). Male children were at greater risk for presence of CVRFC (OR = 1.57, P = .03) compared with female children. Adiponectin (OR = 0.90, P < .001) and leptin levels (OR = 0.98, P = .008) were protective, independent of degree of obesity. Baseline class IV obesity was associated with increased risk compared with overweight of having CVRFC at follow-up (OR = 5.76, P = .001), to a similar extent as class III obesity (OR = 5.36, P = .001). Changes in the degree of obesity were significant predictors of CVRFC on follow-up (OR = 1.04, P < .01 per percent BMI change).

CONCLUSIONS

The metabolic risk associated with obesity in childhood is conferred prior to reaching class IV obesity. An individualized risk stratification approach in children with severe obesity should be based on presence of complications rather than simple BMI cutoffs.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01967849.

The Influence of Gut Microbial Metabolism on the Development and Progression of Non-alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is defined as the presence of excess fat in the liver parenchyma in the absence of excess alcohol consumption and overt inflammation. It has also been described as the hepatic manifestation of metabolic syndrome (Than NN, Newsome PN, Atherosclerosis. 239:192-202, 2015). The incidence of NAFLD has been reported to be 43-60% in diabetics, ~90% in patients with hyperlipidemia and 91% in morbidly obese patients (Than NN, Newsome PN, Atherosclerosis. 239:192-202, 2015, Machado M, Marques-Vidal P, Cortez-Pinto H, J Hepatol, 45:600-606, 2006, Vernon G, Baranova A, Younossi ZM, Aliment Pharmacol Ther, 34:274-285, 2011). The risk factors that have been associated with the development of NAFLD include male gender, increasing age, obesity, insulin resistance, diabetes and hyperlipidemia (Attar BM, Van Thiel DH, Sci World J, 2013:481893, 2013, Gaggini M, Morelli M, Buzzigoli E, DeFronzo RA, Bugianesi E, Gastaldelli A, Forum Nutr, 5:1544-1460, 2013). All of these risk factors have been linked to alterations of the gut microbiota, ie., gut dysbiosis (He X, Ji G, Jia W, Li H, Int J Mol Sci, 17:300, 2016). However, it must be pointed out that the prevalence of NAFLD in normal weight individuals without metabolic risk factors is ~16% (Than NN, Newsome PN, Atherosclerosis. 239:192-202, 2015). This fact has led some investigators to hypothesize that the gut microbiota can impact lipid metabolism in the liver independently of obesity-related metabolic factors (Marchesi JR, Adams DH, Fava F, Hermes GD, Hirschfield GM, Hold g, et al., Gut, 65:330 339, 2016) (Le Roy T, Llopis M, Lepage P, Bruneau A, Rabot S, Bevilacqua C, et al., Gut, 62:1787-1794, 2013). In this chapter, we will explore the effect of the gut microbiota on hepatic lipid metabolism and how this affects the development of NAFLD.

Developmental Origins of Nonalcoholic Fatty Liver Disease (NAFLD)

Nonalcoholic fatty liver disease (NAFLD) is a hepatic manifestation of metabolic syndrome. Its prevalence is currently increasing not only in developed obese countries but also in developing countries. Recent findings from human cohorts and animal studies suggest that a nutritional imbalance in the early critical period is causatively associated with the incidence of NAFLD in later life. Based on the current theory of the developmental origins of health and disease (DOHaD), undernourishment and overnourishment in utero are both hypothesized to prime the predisposition for hepatic fat storage. Current knowledge on the developmental origins of NAFLD is introduced in this chapter.

MTP genetic variants associated with non-alcoholic fatty liver in metabolic syndrome patients

This study was performed for investigation the relationship between variants of MTP gene polymorphism and the development of NAFLD in patients with and without MS. The study was included 174 NAFLD patients (106 with MS and 68 without MS), and 141 healthy control subjects. The 493 G/T polymorphism of MTP gene was evaluated by PCR-RFLP method. The frequency of MTP TT genotype and T allele were significantly higher in NAFLD patients when compared to healthy controls. Moreover, a significant association in MTP gene polymorphism was observed in NAFLD patients with MS compared to NAFLD patients without MS and controls. Our study suggested that MTP 493 G/T gene polymorphism may act as susceptibility biomarker for NAFLD and MS.

Cytokeratin-18 and enhanced liver fibrosis scores in type 1 and type 2 diabetes and effects of two different insulins

Data on cytokeratin-18 (K-18) and enhanced liver fibrosis (ELF) score in insulin-treated diabetes patients with non-alcoholic fatty liver disease (NAFLD) are limited. This study analyzed phase III data comparing basal insulin peglispro (BIL) and insulin glargine in type 1 (T1D), and type 2 diabetes (T2D) (insulin-naïve and insulin-treated). Alanine aminotransferase (ALT), K-18, ELF scores and liver fat content (LFC), measured by MRI, were obtained longitudinally. Baseline K-18 (U/L) was higher in T2D (range: 207‒247) than T1D (range: 148‒183), correlated with ALT in all populations (r (range) 0.264‒0.637, p<0.05), but with LFC only in T2D (r (range) 0.474‒0.586, p<0.05). K-18 increased significantly from baseline in BIL-treated, but not glargine-treated patients. Change from baseline (CFB) K-18 was significantly correlated with CFB in ALT in BIL-treated T2D populations. Baseline ELF scores were higher in T2D (range: 9.12‒9.20) than T1D (range: 8.24‒8.36), correlated with ALT in T1D only (0.209, p<0.05), and not correlated with LFC in any population. ELF scores increased significantly from baseline in BIL-treated but not glargine-treated patients. There were no correlations between CFB in LFC and ELF score at week 52 in any treatment group/population. In all BIL-treated populations, CFB in ALT and CFB in ELF score at week 52 were positively correlated. These data characterize associations of K-18 and ELF score with ALT and LFC in insulin-treated patients with T1D and T2D. Hepatopreferential insulins may be associated with increased K-18 and ELF scores but mechanisms and clinical significance are unknown. ClinicalTrials.gov identifiers are NCT01481779, NCT01435616, NCT01454284 and NCT01582451.

Cell culture models of fatty acid overload: Problems and solutions

High plasma levels of fatty acids occur in a variety of metabolic diseases. Cellular effects of fatty acid overload resulting in negative cellular responses (lipotoxicity) are often studied in vitro, in an attempt to understand mechanisms involved in these diseases. Fatty acids are poorly soluble, and thus usually studied when complexed to albumins such as bovine serum albumin (BSA). The conjugation of fatty acids to albumin requires care pertaining to preparation of the solutions, effective free fatty acid concentrations, use of different fatty acid species, types of BSA, appropriate controls and ensuring cellular fatty acid uptake. This review discusses lipotoxicity models, the potential problems encountered when using these cellular models, as well as practical solutions for difficulties encountered.

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.

AMPK activation caused by reduced liver lactate metabolism protects against hepatic steatosis in MCT1 haploinsufficient mice

Objective

Hepatic steatosis is the first step leading to non-alcoholic fatty liver disease, which represents a major complication of obesity. Here, we show that MCT1 haploinsufficient mice resist to hepatic steatosis development when fed a high fat diet. They exhibit a reduced hepatic capacity to metabolize monocarboxylates such as lactate compared to wildtype mice.

Methods

To understand how this resistance to steatosis develops, we used HFD fed wildtype mice with hepatic steatosis and MCT1 haploinsufficient mice to study hepatic metabolism.

Results

AMPK is constitutively activated in the liver of MCT1 haploinsufficient mice, leading to an inactivation of SREBP1. Therefore, expression of key transcription factors for lipid metabolism, such as PPARα and γ, CHREB, or SREBP1 itself, as well as several enzymes including FAS and CPT1, was not upregulated in these mice when fed a high fat diet. It is proposed that reduced hepatic lactate metabolism is responsible for the protection against hepatic steatosis in MCT1 haploinsufficient mice via a constitutive activation of AMPK and repression of several major elements involved in hepatic lipid metabolism.

Conclusion

Our results support a role of increased lactate uptake in hepatocytes during HFD that, in turn, induce a metabolic shift stimulating SREBP1 activity and lipid accumulation.

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Lactate uptake causes a shift in LDH isoform expression during HFD.

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LDH isoform shift favors a decrease in AMPK activity.

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Lactate uptake reduction in MCT1+/− mice blocks LDH isoform shift and leads to AMPK activation.

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SREBP activation is prevented in MCT1+/− mice due to AMPK activation.

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Decreased expression of SREBP targets involved in lipid metabolism protects against NAFLD.

The Role of Metabolic Surgery in Non-alcoholic Steatohepatitis Improvement

PURPOSE OF REVIEW

Non-alcoholic fatty liver disease (NAFLD) is frequently associated with obesity and overweight. It has a broad spectrum of clinical and histological presentations, such as steatosis, inflammation (known as non-alcoholic steatohepatitis or NASH), fibrosis, and cirrhosis. There is increasing evidence that marked weight loss following bariatric surgery is associated with NASH resolution; however, little is known about the mechanisms that may lead to this beneficial condition and if it is due to weight loss alone. In this review, the authors present the latest data regarding NASH resolution following metabolic surgery and try to answer the following questions: is NASH resolution due to weight loss alone or is it related to weight-independent effects similarly to T2D? In such case, can NASH be considered as a sole criterion for metabolic surgery?

RECENT FINDINGS

Most data evaluating NAFLD and bariatric and metabolic surgery are derived from cohort studies. Available data are extremely variable, but in general show a dramatic regression of steatosis, inflammatory changes, and in some cases even fibrosis that is probably linked to major weight loss following surgery. There are no randomized controlled trials evaluating the effects of metabolic surgery over NASH vs. lifestyle modifications. To consider NASH a sole indication for metabolic surgery regardless of BMI, such studies are desperately needed and should be the primary focus of future research in metabolic surgery.

The sedentary (r)evolution: Have we lost our metabolic flexibility?

During the course of evolution, up until the agricultural revolution, environmental fluctuations forced the human species to develop a flexible metabolism in order to adapt its energy needs to various climate, seasonal and vegetation conditions. Metabolic flexibility safeguarded human survival independent of food availability. In modern times, humans switched their primal lifestyle towards a constant availability of energy-dense, yet often nutrient-deficient, foods, persistent psycho-emotional stressors and a lack of exercise. As a result, humans progressively gain metabolic disorders, such as the metabolic syndrome, type 2 diabetes, non-alcoholic fatty liver disease, certain types of cancer, cardiovascular disease and Alzheimer´s disease, wherever the sedentary lifestyle spreads in the world. For more than 2.5 million years, our capability to store fat for times of food shortage was an outstanding survival advantage. Nowadays, the same survival strategy in a completely altered surrounding is responsible for a constant accumulation of body fat. In this article, we argue that the metabolic disease epidemic is largely based on a deficit in metabolic flexibility. We hypothesize that the modern energetic inflexibility, typically displayed by symptoms of neuroglycopenia, can be reversed by re-cultivating suppressed metabolic programs, which became obsolete in an affluent environment, particularly the ability to easily switch to ketone body and fat oxidation. In a simplified model, the basic metabolic programs of humans' primal hunter-gatherer lifestyle are opposed to the current sedentary lifestyle. Those metabolic programs, which are chronically neglected in modern surroundings, are identified and conclusions for the prevention of chronic metabolic diseases are drawn.

The sedentary (r)evolution: Have we lost our metabolic flexibility?

During the course of evolution, up until the agricultural revolution, environmental fluctuations forced the human species to develop a flexible metabolism in order to adapt its energy needs to various climate, seasonal and vegetation conditions. Metabolic flexibility safeguarded human survival independent of food availability. In modern times, humans switched their primal lifestyle towards a constant availability of energy-dense, yet often nutrient-deficient, foods, persistent psycho-emotional stressors and a lack of exercise. As a result, humans progressively gain metabolic disorders, such as the metabolic syndrome, type 2 diabetes, non-alcoholic fatty liver disease, certain types of cancer, cardiovascular disease and Alzheimer´s disease, wherever the sedentary lifestyle spreads in the world. For more than 2.5 million years, our capability to store fat for times of food shortage was an outstanding survival advantage. Nowadays, the same survival strategy in a completely altered surrounding is responsible for a constant accumulation of body fat. In this article, we argue that the metabolic disease epidemic is largely based on a deficit in metabolic flexibility. We hypothesize that the modern energetic inflexibility, typically displayed by symptoms of neuroglycopenia, can be reversed by re-cultivating suppressed metabolic programs, which became obsolete in an affluent environment, particularly the ability to easily switch to ketone body and fat oxidation. In a simplified model, the basic metabolic programs of humans’ primal hunter-gatherer lifestyle are opposed to the current sedentary lifestyle. Those metabolic programs, which are chronically neglected in modern surroundings, are identified and conclusions for the prevention of chronic metabolic diseases are drawn.

Residential Proximity to Major Roadways, Fine Particulate Matter, and Hepatic Steatosis: The Framingham Heart Study

We examined associations between ambient air pollution and hepatic steatosis among 2,513 participants from the Framingham (Massachusetts) Offspring Study and Third Generation Cohort who underwent a computed tomography scan (2002-2005), after excluding men who reported >21 drinks/week and women who reported >14 drinks/week. We calculated each participant's residential-based distance to a major roadway and used a spatiotemporal model to estimate the annual mean concentrations of fine particulate matter. Liver attenuation was measured by computed tomography, and liver-to-phantom ratio (LPR) was calculated. Lower values of LPR represent more liver fat. We estimated differences in continuous LPR using linear regression models and prevalence ratios for presence of hepatic steatosis (LPR ≤ 0.33) using generalized linear models, adjusting for demographics, individual and area-level measures of socioeconomic position, and clinical and lifestyle factors. Participants who lived 58 m (25th percentile) from major roadways had lower LPR (β = -0.003, 95% confidence interval: -0.006, -0.001) and higher prevalence of hepatic steatosis (prevalence ratio = 1.16, 95% confidence interval: 1.05, 1.28) than those who lived 416 m (75th percentile) away. The 2003 annual average fine particulate matter concentration was not associated with liver-fat measurements. Our findings suggest that living closer to major roadways was associated with more liver fat.

TM5441, a plasminogen activator inhibitor-1 inhibitor, protects against high fat diet-induced non-alcoholic fatty liver disease

Recent evidences showed that elevation of plasminogen activator inhibitor 1 (PAI-1) was responsible in mediating obesity-induced non-alcoholic fatty liver disease (NAFLD) and metabolic disorders. Here, we investigated the effect of TM5441, an oral PAI-1 inhibitor that lacks of bleeding risk, on high-fat diet (HFD)-induced NAFLD. HFD-fed C57BL/6J mice was daily treated with 20 mg/kg TM5441. To examine the preventive effect, 10-week-treatment was started along with initiation of HFD; alternatively, 4-week-treatment was started in mice with glucose intolerance in the interventional strategy. In vivo study showed that early and delayed treatment decreased hepatic steatosis. Particularly, early treatment prevented the progression of hepatic inflammation and fibrosis in HFD mice. Interestingly, both strategies abrogated hepatic insulin resistance and mitochondrial dysfunction, presented by enhanced p-Akt and p-GSK3β, reduced p-JNK signaling, along with p-AMPK and PGC-1α activation. Consistently, TM5441 treatment in the presence of either PAI-1 exposure or TNF-α stimulated-PAI-1 activity showed a restoration of mitochondrial biogenesis related genes expression on HepG2 cells. Thus, improvement of insulin sensitivity and mitochondrial function was imperative to partially explain the therapeutic effects of TM5441, a novel agent targeting HFD-induced NAFLD.

Is there a J-shaped relationship between the fatty liver index and risk of microalbuminuria in the general population?

BACKGROUND

We investigated whether the fatty liver index (FLI), as a clinical indicator of hepatic fat accumulation based on body mass index, gamma-glutamyl-transferase, triglycerides, and waist circumference, has an association with microalbuminuria.

METHODS

We analyzed anthropometric and biochemical data from a nation-wide, population-based, cross-sectional study. A total of 1605 participants included were healthy native Korean 40years or older and divided into quintiles according to their log-FLI and sex. Microalbuminuria was defined as urine albumin/creatinine ratio (UACR) between 30 and 300mg/g.

RESULTS

Participants in higher quintiles of log-FLI were more obese and hypertensive and had greater glycemic exposure, poorer lipid profiles, and greater increases in log-UACR compared with lower quintiles. Linear regression analysis demonstrated that log-FLI was associated with systolic and diastolic blood pressure, body mass index, waist circumference, fasting plasma glucose, glycated hemoglobin, and log-UACR. In logistic regression adjusted for age, sex, body mass index, waist circumference, and fasting plasma glucose, the OR of microalbuminuria was elevated in quintile 1 (adjusted OR=2.161, 95% CI=0.453-10.31) and quintile 5 (adjusted OR=6.387, 95% CI=1.317-51.58), when compared to quintile 2.

CONCLUSIONS

There appears to be a J-shaped association between FLI and UACR in healthy general population.

Efficacy of nanocurcumin supplementation on insulin resistance, lipids, inflammatory factors and nesfatin among obese patients with non-alcoholic fatty liver disease (NAFLD): a trial protocol

OBJECTIVES

Different studies have been conducted on the role of curcumin in health since having multiple properties, including antioxidant and anti-inflammatory effects. Due to the lack of studies regarding curcumin effects on obese patients with non-alcoholic fatty liver disease (NAFLD), our protocol was designed to assess nanocurcumin impacts on blood sugar, lipids, inflammatory indices, insulin resistance and liver function, especially by nesfatin.

SETTING

This trial will be conducted in the Oil Company central hospital of Tehran, Iran with a primary level of care.

PARTICIPANTS

84 obese patients with NAFLD diagnosed using ultrasonography will be employed according to the eligibility criteria‎.

INTERVENTIONS

The patients will be randomly divided into two equal groups (nanocurcumin and placebo, two 40 mg capsules per day with meals for 3 months, follow-up monthly). Also, lifestyle changes (low-calorie diet and physical activity) will be advised.

MEASURES OF THE PRIMARY AND SECONDARY OUTCOMES

A general questionnaire, 24 hours food recall (at the beginning, middle and end) and short-form International Physical Activity Questionnaire will be completed. Blood pressure, anthropometrics, serum sugar indices (fasting blood sugar and insulin, insulin resistance and sensitivity and glycosylated haemoglobin), lipids (triglyceride, total cholesterol and low-density and high-density lipoprotein-cholesterol, inflammatory profiles (interleukin-6, high-sensitivity C-reactive protein, and tumour necrosis factor-alpha), liver function (alanine and aspartate transaminase) and nesfatin will be measured at the beginning and end of the study.

CONCLUSION

This trial would be the first experiment to determine nanocurcumin efficacy on certain blood factors among obese patients with NAFLD. Nevertheless, studying the potential consequences of curcumin in various diseases, especially NAFLD, is required for clinical use.

TRIAL REGISTRATION NUMBER

IRCT2016071915536N3; pre-results.

Apolipoprotein O expression in mouse liver enhances hepatic lipid accumulation by impairing mitochondrial function

Apolipoprotein O (ApoO) was recently observed in the cellular mitochondrial inner membrane, which plays a role in mitochondrial function and is associated with myocardiopathy. Empirical information on the physiological functions of apoO is therefore limited. In this study, we aimed to elucidate the effect of apoO on hepatic fatty acid metabolism. An adenoviral vector expressing hApoO was constructed and introduced into chow diet and high-fat diet induced mice and the L02 human hepatoma cell line. High levels of hApoO mRNA and protein were detected in the liver, and the expression of lipid metabolism genes was significantly altered compared with negative controls. The liver function indices (serum ALT and AST) were clearly elevated, and the ultrastructure of cellular mitochondria was distinctly altered in the liver after apoO overexpression. Further, mitochondrial membrane potential decreased with hApoO treatment in L02 cells. These results establish a link between apoO and lipid accumulation and could suggest a new pathway for regulating non-alcoholic fatty liver disease progression.

Non-alcoholic fatty liver disease: An update with special focus on the role of gut microbiota

Non-alcoholic fatty liver disease (NAFLD) is a significant global health burden in children, adolescents and adults with substantial rise in prevalence over the last decades. Accumulating data from manifold studies support the idea of NAFLD as a hepatic manifestation of metabolic syndrome, being rather a systemic metabolic disease than a liver confined pathology. Emerging data support that the gut microbiome represents a significant environmental factor contributing to NAFLD development and progression. Apart from other regimens, probiotics may have a positive role in the management of NAFLD through a plethora of possible mechanisms. The current review focuses on the NAFLD multifactorial pathogenesis, including mainly the role of intestinal microbiome and all relevant issues are raised. Furthermore, the clinical manifestations and appropriate diagnostic approach of the disease are discussed, with all possible therapeutic measures that can be taken, also including the potential beneficial effect of probiotics.

MiR-130a-3p attenuates activation and induces apoptosis of hepatic stellate cells in nonalcoholic fibrosing steatohepatitis by directly targeting TGFBR1 and TGFBR2

Nonalcoholic fibrosing steatohepatitis is a uniform process that occurs throughout nonalcoholic fatty liver disease (NAFLD). MicroRNAs (miRNAs) have been shown to be involved in the biological processes, but the role and molecular mechanism of miRNAs in NAFLD are not entirely clear. In this study, we observed a significant reduction in the expression of miR-130a-3p in livers of a mouse model with fibrosis induced by a methionine–choline-deficient diet, of NAFLD patients, and in activated hepatic stellate cells (HSCs). A dual-luciferase activity assay confirmed that transforming growth factor-beta receptors (TGFBRs) 1 and 2 were both the target genes of miR-130a-3p. The hepatic expression of TGFBR1 and TGFBR2 was significantly increased. Moreover, the overexpression of miR-130a-3p in HSCs inhibited HSC activation and proliferation, concomitant with the decreased expression of TGFBR1, TGFBR2, Smad2, Smad3, matrix metalloproteinase-2 (MMP-2), MMP-9, type I collagen (Col-1), and Col-4. In addition, the overexpression of miR-130a-3p promoted HSC apoptosis by inducing the expression of caspase-dependent apoptosis genes. Transfection with si-TGFBR1 and si-TGFBR2 revealed effects on HSC function that were consistent with those of miR-130a-3p. TGFBR1 and TGFBR2 rescued the miR-130a-3p-mediated reductions in the mRNA and protein expression levels of Smad2, Smad3, Col-1, and Col-4. In conclusion, our findings suggest that miR-130a-3p might play a critical role in negatively regulating HSC activation and proliferation in the progression of nonalcoholic fibrosing steatohepatitis by directly targeting TGFBR1 and TGFBR2 via the TGF-β/SMAD signaling pathway.

Opportunities and challenges in the wider adoption of liver and interconnected microphysiological systems

Liver disease represents a growing global health burden. The development of in vitro liver models which allow the study of disease and the prediction of metabolism and drug-induced liver injury in humans remains a challenge. The maintenance of functional primary hepatocytes cultures, the parenchymal cell of the liver, has historically been difficult with dedifferentiation and the consequent loss of hepatic function limiting utility. The desire for longer term functional liver cultures sparked the development of numerous systems, including collagen sandwiches, spheroids, micropatterned co-cultures and liver microphysiological systems. This review will focus on liver microphysiological systems, often referred to as liver-on-a-chip, and broaden to include platforms with interconnected microphysiological systems or multi-organ-chips. The interconnection of microphysiological systems presents the opportunity to explore system level effects, investigate organ cross talk, and address questions which were previously the preserve of animal experimentation. As a field, microphysiological systems have reached a level of maturity suitable for commercialization and consequent evaluation by a wider community of users, in academia and the pharmaceutical industry. Here scientific, operational, and organizational considerations relevant to the wider adoption of microphysiological systems will be discussed. Applications in which microphysiological systems might offer unique scientific insights or enable studies currently feasible only with animal models are described, and challenges which might be addressed to enable wider adoption of the technologies are highlighted. A path forward which envisions the development of microphysiological systems in partnerships between academia, vendors and industry, is proposed. Impact statement Microphysiological systems are in vitro models of human tissues and organs. These systems have advanced rapidly in recent years and are now being commercialized. To achieve wide adoption in the biological and pharmaceutical research communities, microphysiological systems must provide unique insights which translate to humans. This will be achieved by identifying key applications and making microphysiological systems intuitive to use.

Liver fat: a relevant target for dietary intervention? Summary of a Unilever workshop

Currently it is estimated that about 1 billion people globally have non-alcoholic fatty liver disease (NAFLD), a condition in which liver fat exceeds 5 % of liver weight in the absence of significant alcohol intake. Due to the central role of the liver in metabolism, the prevalence of NAFLD is increasing in parallel with the prevalence of obesity, insulin resistance and other risk factors of metabolic diseases. However, the contribution of liver fat to the risk of type 2 diabetes mellitus and CVD, relative to other ectopic fat depots and to other risk markers, is unclear. Various studies have suggested that the accumulation of liver fat can be reduced or prevented via dietary changes. However, the amount of liver fat reduction that would be physiologically relevant, and the timeframes and dose-effect relationships for achieving this through different diet-based approaches, are unclear. Also, it is still uncertain whether the changes in liver fat per se or the associated metabolic changes are relevant. Furthermore, the methods available to measure liver fat, or even individual fatty acids, differ in sensitivity and reliability. The present report summarises key messages of presentations from different experts and related discussions from a workshop intended to capture current views and research gaps relating to the points above.

Ginseng seed oil ameliorates hepatic lipid accumulation in vitro and in vivo

Background

Despite the large number of studies on ginseng, pharmacological activities of ginseng seed oil (GSO) have not been established. GSO is rich in unsaturated fatty acids, mostly oleic and linoleic acids. Unsaturated fatty acids are known to exert a therapeutic effect in nonalcoholic fatty liver disease (NAFLD). In this study, we investigated the protective effect and underlying mechanisms of GSO against NAFLD using in vitro and in vivo models.

Methods

In vitro lipid accumulation was induced by free fatty acid mixture in HepG2 cells and by 3 wk of high fat diet (HFD)-feeding in Sprague-Dawley rats prior to hepatocyte isolation. The effects of GSO against diet-induced hepatic steatosis were further examined in C57BL/6J mice fed a HFD for 12 wk.

Results

Oil Red O staining and intracellular triglyceride levels showed marked accumulation of lipid droplets in both HepG2 cells and rat hepatocytes, and these were attenuated by GSO treatment. In HFD-fed mice, GSO improved HFD-induced dyslipidemia and hepatic insulin resistance. Increased hepatic lipid contents were observed in HFD-fed mice and it was lowered in GSO (500 mg/kg)-treated mice by 26.4% which was evident in histological analysis. Pathway analysis of hepatic global gene expression indicated that GSO increased the expression of genes associated with β-oxidation (Ppara, Ppargc1a, Sirt1, and Cpt1a) and decreased the expression of lipogenic genes (Srebf1 and Mlxipl), and these were confirmed with reverse transcription and quantitative polymerase-chain reaction.

Conclusion

These findings suggest that GSO has a beneficial effect on NAFLD through the suppression of lipogenesis and stimulation of fatty acid degradation pathway.

Free-breathing liver fat quantification using a multiecho 3D stack-of-radial technique

PURPOSE

The diagnostic gold standard for nonalcoholic fatty liver disease is an invasive biopsy. Noninvasive Cartesian MRI fat quantification remains limited to a breath-hold (BH). In this work, a novel free-breathing 3D stack-of-radial (FB radial) liver fat quantification technique is developed and evaluated in a preliminary study.

METHODS

Phantoms and healthy subjects (n = 11) were imaged at 3 Tesla. The proton-density fat fraction (PDFF) determined using FB radial (with and without scan acceleration) was compared to BH single-voxel MR spectroscopy (SVS) and BH 3D Cartesian MRI using linear regression (correlation coefficient ρ and concordance coefficient ρ_c ) and Bland-Altman analysis.

RESULTS

In phantoms, PDFF showed significant correlation (ρ > 0.998, ρ_c  > 0.995) and absolute mean differences < 2.2% between FB radial and BH SVS, as well as significant correlation (ρ > 0.999, ρ_c  > 0.998) and absolute mean differences < 0.6% between FB radial and BH Cartesian. In the liver and abdomen, PDFF showed significant correlation (ρ > 0.986, ρ_c  > 0.985) and absolute mean differences < 1% between FB radial and BH SVS, as well as significant correlation (ρ > 0.996, ρ_c  > 0.995) and absolute mean differences < 0.9% between FB radial and BH Cartesian.

CONCLUSION

Accurate 3D liver fat quantification can be performed in 1 to 2 min using a novel FB radial technique. Magn Reson Med 79:370-382, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

Nonalcoholic Fatty Liver Disease and Insulin Resistance: New Insights and Potential New Treatments

Nonalcoholic fatty liver disease (NAFLD) is one of the most common chronic liver disorders worldwide. It is associated with clinical states such as obesity, insulin resistance, and type 2 diabetes, and covers a wide range of liver changes, ranging from simple steatosis to non-alcoholic steatohepatitis (NASH), liver cirrhosis, and hepatocellular carcinoma. Metabolic disorders, such as lipid accumulation, insulin resistance, and inflammation, have been implicated in the pathogenesis of NAFLD, but the underlying mechanisms, including those that drive disease progression, are not fully understood. Both innate and recruited immune cells mediate the development of insulin resistance and NASH. Therefore, modifying the polarization of resident and recruited macrophage/Kupffer cells is expected to lead to new therapeutic strategies in NAFLD. Oxidative stress is also pivotal for the progression of NASH, which has generated interest in carotenoids as potent micronutrient antioxidants in the treatment of NAFLD. In addition to their antioxidative function, carotenoids regulate macrophage/Kupffer cell polarization and thereby prevent NASH progression. In this review, we summarize the molecular mechanisms involved in the pathogenesis of NAFLD, including macrophage/Kupffer cell polarization, and disturbed hepatic function in NAFLD. We also discuss dietary antioxidants, such as β-cryptoxanthin and astaxanthin, that may be effective in the prevention or treatment of NAFLD.

Probiotics may delay the progression of nonalcoholic fatty liver disease by restoring the gut microbiota structure and improving intestinal endotoxemia

Gut-derived bacterial lipopolysaccharide (LPS) and subsequent hepatic toll-like receptor 4 (TLR4) activation have been recognized to be involved in the onset of diet-induced nonalcoholic fatty liver disease (NAFLD), but little is known about the variation of LPS and TLR4 during the progression of NAFLD. Probiotics were able to inhibit proliferation of harmful bacteria and improve gastrointestinal barrier function. However, it's unclear whether LPS/TLR4 is involved in the protection effect of probiotics on NAFLD. In this study, we described characteristic of gut microbiota structure in the progression of NAFLD, and we also analyzed the relationship between gut microbiota and LPS/TLR4 in this process. Furthermore, we applied probiotics intervention to investigate the effect of probiotics on gut flora structure, intestinal integrity, serum LPS, liver TLR4 and liver pathology. Our results showed that serum LPS and liver TLR4 were highly increased during progression of NAFLD, with gut flora diversity and gut mircobiological colonization resistance (B/E) declining. Furthermore, probiotics could improve gut microbiota structure and liver pathology. Probiotics could also downregulate serum LPS and liver TLR4. Our results suggested that both gut flora alteration and endotoxemia may be involved in the progression of NAFLD. Probiotics may delay the progression of NAFLD via LPS/TLR4 signaling.

Altered hepatic lipid metabolism in mice lacking both the melanocortin type 4 receptor and low density lipoprotein receptor

Obesity is often associated with dyslipidemia and hepatosteatosis. A number of animal models of non-alcoholic fatty liver disease (NAFLD) are established but they significantly differ in the molecular and biochemical changes depending on the genetic modification and diet used. Mice deficient for melanocortin type 4 receptor (Mc4r^mut) develop hyperphagia, obesity, and subsequently NAFLD already under regular chow and resemble more closely the energy supply-driven obesity found in humans. This animal model was used to assess the molecular and biochemical consequences of hyperphagia-induced obesity on hepatic lipid metabolism. We analyzed transcriptome changes in Mc4r^mut mice by RNA sequencing and used high resolution ¹H magic angle spinning NMR spectroscopy and MALDI-TOF mass spectrometry to assess changes in the lipid composition. On the transcriptomic level we found significant changes in components of the triacylglycerol metabolism, unsaturated fatty acids biosynthesis, peroxisome proliferator-activated receptor signaling pathways, and lipid transport and storage compared to the wild-type. These findings were supported by increases in triacylglycerol, monounsaturated fatty acid, and arachidonic acid levels. The transcriptome signatures significantly differ from those of other NAFLD mouse models supporting the concept of hepatic subphenotypes depending on the genetic background and diet. Comparative analyses of our data with previous studies allowed for the identification of common changes and genotype-specific components and pathways involved in obesity-associated NAFLD.