The role of fatty acids in the development and progression of nonalcoholic fatty liver disease

Effects of perfluoroalkyl sulfonic acids on developmental, physiological, and immunological measures in northern leopard frog tadpoles

The chronic toxicity of short chain perfluoroalkyl sulfonic acids (PFSAs), such as perfluorobutanesulfonic acid (PFBS) and perfluorohexanesulfonic acid (PFHxS), are relatively understudied despite the increasing detection of these compounds in the environment. We investigated the chronic toxicity and bioconcentration of PFBS and PFHxS using northern leopard frog (Rana [Lithobates] pipiens) tadpoles. We exposed Gosner stage (GS) 25 tadpoles to either PFBS or PFHxS at nominal concentrations of 0.1, 1, 10, 100, and 1000 μg/L until metamorphosis (GS42). We then assessed tadpole growth, development, stress, and immune metrics, and measured fatty acid (FA) composition and PFSA concentrations in liver and whole-body tissues. Tadpole growth and development measures were relatively unaffected by PFSA exposure. However, tadpoles exposed to 1000 μg/L PFBS or PFHxS had significantly increased hepatosomatic indexes (HSI) relative to controls. Further, tadpoles from the 1000 μg/L PFHxS treatment had altered FA profiles relative to controls, with increased total FAs, saturated FAs, monounsaturated FAs, and omega-6 polyunsaturated FAs. In addition, tadpoles from the 1000 μg/L PFHxS treatment had a higher probability of waterborne corticosterone detection. These results suggest that PFBS and PFHxS influence the hepatic health of tadpoles, and that PFHxS may alter lipid metabolism in tadpoles. We also observed a higher probability of tadpoles being phenotypically female after exposure to an environmentally relevant concentration (0.1 μg/L) of PFHxS, suggesting that PFHxS may exert endocrine disrupting effects on tadpoles during early development. The measured bioconcentration factors (BCFs) for both compounds were ≤10 L kg-1 wet weight, suggesting low bioconcentration potential for PFBS and PFHxS in tadpoles. Many of the significant effects observed in this study occurred at concentrations several orders of magnitude above those measured in the environment; however, our work shows effects of PFSAs exposure on amphibians and provides essential information for ecological risk assessments of these compounds.

FABP1 induces lipogenesis by regulating the processing of SREBP1 in hepatocytes of large yellow croaker (Larimichthys crocea)

Fatty acid-binding protein 1 (FABP1) plays an important role in regulating fatty acid metabolism in liver, which is a potential therapeutic target for diseases such as non-alcoholic fatty liver disease (NAFLD). However, the underlying mechanisms are not well defined. Using complementary experimental models, we discovered FABP1 induction in hepatocytes as a primary mediator of lipogenesis when exposed to fatty acids, especially saturated fatty acids (SFAs). In the feeding trial, palm oil led to excess lipid accumulation in the liver of large yellow croaker (Larimichthys crocea), accompanied by significant induction of FABP1. In cultured cells, palmitic acid (PA), a kind of SFA, triggered the fabp1 expression and increased triglyceride (TG) contents. Knockdown of FABP1 dampened PA-induced TG accumulation through mitigated lipogenesis. The overexpression of FABP1 showed the opposite result. Furthermore, the inactivation of FABP1 led to induction in insulin-induced gene 1 (INSIG1) expression, which attenuated the processing of sterol regulatory element-binding protein 1 (SREBP1) by down-regulating the nuclear-localized SREBP1. These results revealed a previously unrecognized function of FABP1 in response to PA, providing additional evidence for targeting FABP1 in the treatment of NAFLD caused by SFA.

Global perspective on nonalcoholic fatty liver disease and nonalcoholic steatohepatitis - prevalence, clinical impact, economic implications and management strategies

BACKGROUND

The metabolically-based liver disease, nonalcoholic fatty liver disease (NAFLD), is the most common cause of chronic liver disease currently affecting 38% of the world's adult population. NAFLD can be progressive leading to nonalcoholic steatohepatitis (NASH), liver transplantation, liver cancer, liver-related mortality and is associated with decreased quality of life from impaired physical functioning and increased healthcare resource utilisation. However, screening for NAFLD is cost-prohibitive but screening for high risk NAFLD (NAFLD with F2 fibrosis or greater) is imperative.

AIM

To review the global perspective on NAFLD and NASH METHODS: We retrieved articles from PubMed using search terms NAFLD, prevalence, clinical burden, economic burden and management strategies.

RESULTS

NAFLD/NASH shows geographical variation across the globe. Highest prevalence rates are in South America and the Middle East and North Africa; lowest prevalence is in Africa. NAFLD's economic impact is from direct and indirect medical costs and loss in worker productivity. It is projected that, over the next two decades, the total cost of NAFLD and diabetes will exceed $1.5 trillion (USD). Risk stratification algorithms identifying "high risk NAFLD" were made following non-invasive tests for NAFLD identification and fibrosis development. These algorithms should be used in primary care and endocrinology settings so timely and appropriate interventions (lifestyle and cardiometabolic risk factor management) can be initiated.

CONCLUSIONS

To reduce the burgeoning burden of NAFLD/NASH, management should include risk stratification algorithms for accurate identification of patients, linkage to appropriate settings, and initiation of effective treatment regimens.

Ceramide on the road to insulin resistance and immunometabolic disorders in transition dairy cows: driver or passenger?

Dairy cows must undergo profound metabolic and endocrine adaptations during their transition period to meet the nutrient requirements of the developing fetus, parturition, and the onset of lactation. Insulin resistance in extrahepatic tissues is a critical component of homeorhetic adaptations in periparturient dairy cows. However, due to increased energy demands at calving that are not followed by a concomitant increase in dry matter intake, body stores are mobilized, and the risk of metabolic disorders dramatically increases. Sphingolipid ceramides involved in multiple vital biological processes, such as proliferation, differentiation, apoptosis, and inflammation. Three typical pathways generate ceramide, and many factors contribute to its production as part of the cell's stress response. Based on lipidomic profiling, there has generally been an association between increased ceramide content and various disease outcomes in rodents. Emerging evidence shows that ceramides might play crucial roles in the adaptive metabolic alterations accompanying the initiation of lactation in dairy cows. A series of studies also revealed a negative association between circulating ceramides and systemic insulin sensitivity in dairy cows experiencing severe negative energy balance. Whether ceramide acts as a driver or passenger in the metabolic stress of periparturient dairy cows is an unknown but exciting topic. In the present review, we discuss the potential roles of ceramides in various metabolic dysfunctions and the impacts of their perturbations. We also discuss how this novel class of bioactive sphingolipids has drawn interest in extrahepatic tissue insulin resistance and immunometabolic disorders in transition dairy cows. We also discuss the possible use of ceramide as a new biomarker for predicting metabolic diseases in cows and highlight the remaining problems.

Olive Oil's Attenuating Effects on Lipotoxicity

Dietary fatty acids play a role in the pathogenesis of obesity-associated nonalcoholic fatty liver disease. Lipotoxicity in obesity mediates insulin resistance, endothelial dysfunction, atherosclerosis, and gut microbiota dysbiosis. Cardiovascular complications are the main cause of morbidity and mortality in obese, insulin-resistant, and type 2 diabetes mellitus patients.Interventions targeting lipotoxicity are the main issue in preventing its multiple insults. Lifestyle modifications including healthy eating and regular exercise are the primary recommendations. Treatments also include drugs targeting energy intake, energy disposal, lipotoxic liver injury, and the resulting inflammation, fibrogenesis, and cirrhosis.Diet and nutrition have been linked to insulin resistance, an increased risk of developing type 2 diabetes, and impaired postprandial lipid metabolism. Low-fat diets are associated with higher survival. The Mediterranean diet includes an abundance of olive oil. Extra-virgin olive oil is the main source of monounsaturated fatty acids in Mediterranean diets. An olive oil-rich diet decreases triglyceride accumulation in the liver, improves postprandial triglyceride levels, improves glucose and insulin secretions, and upregulates GLUT-2 expression in the liver. The exact molecular mechanisms of olive oil's effects are unknown, but decreasing NF-kB activation, decreasing LDL oxidation, and improving insulin resistance by reducing the production of inflammatory cytokines (TNF-α and IL-6) and upregulating kinases and JNK-mediated phosphorylation of IRS-1 are possible principal mechanisms. Olive oil phenolic compounds also modulate gut microbiota diversity, which also affects lipotoxicity.In this review, we document lipotoxicity in obesity manifestations and the beneficial health effects of the Mediterranean diet derived from monounsaturated fatty acids, mainly from olive oil.

The Ameliorating Effects of n-3 Polyunsaturated Fatty Acids on Liver Steatosis Induced by a High-Fat Methionine Choline-Deficient Diet in Mice

The pathogenesis of non-alcoholic fatty liver disease (NAFLD) is associated with abnormalities of liver lipid metabolism. On the contrary, a diet enriched with n-3 polyunsaturated fatty acids (n-3-PUFAs) has been reported to ameliorate the progression of NAFLD. The aim of our study was to investigate the impact of dietary n-3-PUFA enrichment on the development of NAFLD and liver lipidome. Mice were fed for 6 weeks either a high-fat methionine choline-deficient diet (MCD) or standard chow with or without n-3-PUFAs. Liver histology, serum biochemistry, detailed plasma and liver lipidomic analyses, and genome-wide transcriptome analysis were performed. Mice fed an MCD developed histopathological changes characteristic of NAFLD, and these changes were ameliorated with n-3-PUFAs. Simultaneously, n-3-PUFAs decreased serum triacylglycerol and cholesterol concentrations as well as ALT and AST activities. N-3-PUFAs decreased serum concentrations of saturated and monounsaturated free fatty acids (FAs), while increasing serum concentrations of long-chain PUFAs. Furthermore, in the liver, the MCD significantly increased the hepatic triacylglycerol content, while the administration of n-3-PUFAs eliminated this effect. Administration of n-3-PUFAs led to significant beneficial differences in gene expression within biosynthetic pathways of cholesterol, FAs, and pro-inflammatory cytokines (IL-1 and TNF-α). To conclude, n-3-PUFA supplementation appears to represent a promising nutraceutical approach for the restoration of abnormalities in liver lipid metabolism and the prevention and treatment of NAFLD.

The analysis of fatty acids and their derivatives in the liver of C57BL/6 mice with long-term caloric restrictions

Caloric restriction (CR) is a dietetic intervention based on the reduction of daily calorie intake by 10-30 %. When subjected to CR, the organism adjusts its metabolism to the changing availability of key nutrients. However, fatty acids' content in organisms subjected to long-term CR has not been evaluated. The aim of the research was to analyze the influence of long-term CR on the contents of medium- and long-chain fatty acids, as well as on the contents of fatty acid derivatives in liver. The study was performed on C57BL female (n = 12) and male (n = 12) mice subjected to lifelong 30 % calorie restriction. Fatty acids were analyzed using gas chromatography, while fatty acid derivatives were analyzed with liquid chromatography. The dynamics of change of the lipid profile of the labeled fatty acids observed in the liver tissue confirms that lipolysis actively takes place in this organ when hungry. Moreover, it is highly possible that de novo synthesis of acids takes place, with the aim to ensure energy substrates to the body. Moreover, an increase of concentration was observed for fatty acid derivatives, those with anti-inflammatory properties (resolvin, LTX A4). However, there was no increase in the concentration of pro-inflammatory eicosanoids. The results suggest that it is important to take into consideration the introduction of appropriate supplements when using CR.

The magnitude of undiagnosed diabetes mellitus, prediabetes, and associated factors among adults living in Debre Tabor town, northcentral Ethiopia: A community-based cross-sectional study

Background

Diabetes mellitus (DM) is a worldwide public health problem. The burden of diabetes has been continuously increasing from day to day, especially in developing countries like Ethiopia. Globally, half of all cases of diabetes mellitus are undiagnosed. Diabetes mellitus can be easily handled if it is detected early. There is limited evidence on the magnitude of undiagnosed diabetics and prediabetes at the community level in Ethiopia, particularly in the study area.

Objective

To assess the magnitude of undiagnosed diabetes mellitus, prediabetes, and associated factors among adults living in Debre Tabor town.

Methods

A community-based cross-sectional study was conducted in Debre Tabor town from October to December 2021. A total of 407 participants were selected using a multistage sampling technique. A pretested structural questionnaire was used to collect demographic, behavioral, and clinical data. Anthropometric measurements were taken with standardized and calibrated equipment. A fasting venous blood sample was collected for blood glucose level determination. Logistic regression was used to identify risk factors. A P-value ≤0.05 was considered statistically significant.

Result

The magnitude of undiagnosed diabetes mellitus and prediabetes was found to be 4.5% (95% CI: 2.9-7.4) and 14.5% (95% CI: 11.1-18.1), respectively. Older age (AOR: 6.50, 95% CI: 1.82-23.21), abnormal body mass index (AOR: 6.84, 95% CI: 1.91-24.54), systolic hypertension (AOR: 8.74, 95% CI: 2.53-30.19), and family history of diabetes mellitus (FHDM) (AOR: 12.45, 95% CI: 3.63-42.65) were significantly associated with undiagnosed diabetes mellitus. Using saturated oil (AOR: 1.97, 95% CI: 1.09-3.55), having a high waist circumference (AOR: 2.16, 95% CI: 1.20-3.87), and being hypertensive (AOR: 2.26, 95% CI: 1.04-4.96) were all significantly associated with Prediabetes.

Conclusion

Adults in Debre Tabor town have a high prevalence of undiagnosed diabetes and prediabetes. A variety of modifiable risk factors were also identified. As a result, focusing the prevention strategy on such modifiable risk factors may help to minimize the prevalence of undiagnosed diabetes mellitus and prediabetes as well as future disease complications.

Quantitative chemometric phenotyping of three-dimensional liver organoids by Raman spectral imaging

Confocal Raman spectral imaging (RSI) enables high-content, label-free visualization of a wide range of molecules in biological specimens without sample preparation. However, reliable quantification of the deconvoluted spectra is needed. Here we develop an integrated bioanalytical methodology, qRamanomics, to qualify RSI as a tissue phantom calibrated tool for quantitative spatial chemotyping of major classes of biomolecules. Next, we apply qRamanomics to fixed 3D liver organoids generated from stem-cell-derived or primary hepatocytes to assess specimen variation and maturity. We then demonstrate the utility of qRamanomics for identifying biomolecular response signatures from a panel of liver-altering drugs, probing drug-induced compositional changes in 3D organoids followed by in situ monitoring of drug metabolism and accumulation. Quantitative chemometric phenotyping constitutes an important step in developing quantitative label-free interrogation of 3D biological specimens.

Understanding NAFLD: From Case Identification to Interventions, Outcomes, and Future Perspectives

While non-alcoholic fatty liver disease (NAFLD) is a prevalent and frequent cause of liver-related morbidity and mortality, it is also strongly associated with cardiovascular disease-related morbidity and mortality, likely driven by its associations with insulin resistance and other manifestations of metabolic dysregulation. However, few satisfactory pharmacological treatments are available for NAFLD due in part to its complex pathophysiology, and challenges remain in stratifying individual patient's risk for liver and cardiovascular disease related outcomes. In this review, we describe the development and progression of NAFLD, including its pathophysiology and outcomes. We also describe different tools for identifying patients with NAFLD who are most at risk of liver-related and cardiovascular-related complications, as well as current and emerging treatment options, and future directions for research.

Graduate Student Literature Review: A scoping review on the impact of consumption of dairy products on phosphatidylcholine and lysophosphatidylcholine in circulation and the liver in human studies and animal models

Dairy consumption is inversely related to the risk of developing type 2 diabetes in epidemiological research. One proposed hypothesis is that phospholipid (PL) species associated with dairy consumption mediate this relationship. This scoping review aimed to identify the existing literature in animal and human trials investigating the impact of dairy products, including milk, yogurt, and cheese as well as dairy-derived PL supplementation on PL and its species in the circulation, summarizing the characteristics of these studies and identifying research gaps. A systematic search was conducted across 3 databases (PubMed, Scopus, and Web of Science) in March 2021. Of 2,427 identified references, 15 studies (7 humans and 8 animal studies) met the eligibility criteria and were included in the final narrative synthesis. The evidence base was heterogeneous, involving a variety of clinical and preclinical studies, metabolically healthy or obese/diabetic participants or animal models, and displayed mixed findings. Circulating postprandial concentrations of total PL were elevated acutely but unchanged after longer intervention with dairy products. The PL concentration remained stable even after a high dosage of milk supplemented with dairy-derived PL, which may be related to increased fecal excretion; however, certain phosphatidylcholine (PC) or lysophosphatidylcholine species were increased in circulation by interventions. These include several PC species with 32 to 38 total carbons in addition to the dairy biomarkers C15:0 and C17:0. The results of this scoping review demonstrate a small body of literature indicating that dairy products can influence blood concentrations of PC and lysophosphatidylcholine species in both rodents and humans without alteration of total PL and PC. There is a lack of well-designed trials in humans and animals that explore the potential differences between individual dairy foods on PL species. In addition, trials to understand the bioactive properties of PC and lysophosphatidylcholine species on cardiometabolic risk are needed.

Mitochondrial Peroxiredoxin III Protects against Non-Alcoholic Fatty Liver Disease Caused by a Methionine-Choline Deficient Diet

Non-alcoholic fatty liver disease (NAFLD) is emerging as the most common chronic liver disease worldwide. In addition, NAFLD may increase the risk of cardiovascular and liver-related diseases, and displays features of metabolic syndrome. In NAFLD, oxidative stress is primarily caused by excessive free fatty acids. The oxidation of fatty acids is usually caused by β-oxidation of mitochondria under normal conditions, resulting in the production of energy. However, when the inflow of fatty acids in NAFLD becomes excessive, the β-oxidation of mitochondria becomes saturated and the oxidation process increases at sites including peroxisomes and microsomes, thereby increasing production of reactive oxygen species (ROS). Thus, hepatic mitochondrial ROS play an important role in the pathogenesis of NAFLD. Eliminating mitochondrial ROS may improve NAFLD, but the underlying mechanism remains unclear. We examined the effect of mitochondrial ROS on NAFLD by focusing on peroxiredoxin (Prx), an antioxidant protein that can remove hydrogen peroxide. The protective effect and pathological phenomenon of mitochondrial peroxiredoxin in methionine-choline deficient diet (MCD)-induced liver injury was assessed in a mouse model of NAFLD. In these mice, mitochondrial peroxiredoxin deficiency significantly increased hepatic steatosis and fibrosis. In addition, ablation of Prx III enhances susceptibility to MCD diet-induced oxidative stress and exacerbates NAFLD progression by promoting inflammation. The binding assay results also showed that Prx III-deficient mice had more severe liver damage than Prx III-abundant mice in MCD diet liver injury models. The present data suggest that mitochondrial peroxiredoxin III could be a therapeutic target for preventing and suppressing diet-induced NAFLD.

Time to transition from a negative nomenclature describing what NAFLD is not, to a novel, pathophysiology-based, umbrella classification of fatty liver disease (FLD)

Non-alcoholic fatty liver disease (NAFLD) is a definition of a prevalent condition that has been given a name describing what the disease is not, mainly due to gaps in the physiopathological understanding of NAFLD when the name was given to it. NAFLD still remains an unmet clinical need to a large extent due to the heterogenicity of the disease and the lack of a more accurate physiology-based classification. In essence, fatty liver disease (FLD) has a multifactorial etiology, including metabolic abnormalities, environmental influences, genetic disorders, and/or their overlap which makes it difficult to diagnose, design appropriate trials for it and treat this disease. Therefore, we propose herein that as our knowledge about this disease continues to grow exponentially, it is time to consider ending this unspecific, negative and broad classification of NAFLD, and turn it into a positive and targeted one describing what the disease is and not what it is not. Thus, we propose the novel FLD "Mantzoros classification". This innovative classification proposes to classify the heterogeneous causes of FLD under one umbrella and eventually lead to a better nomenclature and classification system reflecting pathophysiology. This in turn could lead to both better clinical trials and more personalized care. An additional aim is to generate a dialogue among the experts in this field to eventually reach the right nomenclature for an appropriate disease classification that would facilitate our understanding, approach, diagnosis, and management of this epidemic of FLD. Overall, a novel classification, based on phenotypic manifestations, leading risk factors and probable causes of FLD, could help our understanding and clinically would be accurately defining and differentiating the disease, leading to a more accurate design and execution of clinical trials. This would in turn lead to tangible benefits for all patients suffering from FLD through targeted and more effective personalized treatments.

Crossbred Sows Fed a Western Diet during Pre-Gestation, Gestation, Lactation, and Post-Lactation Periods Develop Signs of Lean Metabolic Syndrome That Are Partially Attenuated by Spirulina Supplementation

Excessive dietary intake of fats and sugars (“Western diet”, WD) is one of the leading causes of obesity. The consumption of the microalga Arthrospira platensis (spirulina, Sp) is increasing due to its presumed health benefits. Both WD and Sp are also consumed by pregnant and breastfeeding women. This study investigated if gestating and lactating domestic pigs are an appropriate model for WD-induced metabolic disturbances similar to those observed in humans and if Sp supplementation may attenuate any of these adverse effects. Pigs were fed a WD high in fat, sugars, and cholesterol or a control diet. Half of the animals per diet group were supplemented with 20 g Sp per day. The WD did not increase body weight or adipose tissue accumulation but led to metabolic impairments such as higher cholesterol concentration in plasma, lower IGF1 plasma levels, and signs of hepatic damage compared to the control group. Spirulina supplementation could not reduce all the metabolic impairments observed in WD-fed animals. These findings indicate limited suitability of gestating and lactating domestic pigs as a model for WD but a certain potential of low-dose Sp supplementation to partially attenuate negative WD effects.

Development of an in vitro insulin resistance dissociated model of hepatic steatosis by co-culture system

The evidence shows that there is an associated relationship between hepatosteatosis and insulin resistance. While some existing genetic induction animal and patient models challenge this relationship, indicating that hepatosteatosis is dissociated from insulin resistance. However, the molecular mechanisms of this dissociation remain poorly understood due to a lack of available, reliable, and simplistic setup models. Currently, we used primary rat hepatocytes (rHPCs), co-cultured with rat hepatic stellate cells (HSC-T6) or human foreskin fibroblast cells (HFF-1) in stimulation with high insulin and glucose, to develop a model of steatosis charactered as dissociated lipid accumulation from insulin resistance. Oil-Red staining significantly showed intracellular lipid accumulated in the developed model. Gene expression of sterol regulatory element-binding protein 1c (SREBP1c) and elongase of very-long-chain fatty acids 6 (ELOVL6), key genes responsible for lipogenesis, were detected and obviously increased in this model. Inversely, the insulin resistance related genes expression included phosphoenolpyruvate carboxykinase 1 (PCK1), pyruvate dehydrogenase lipoamide kinase isozyme 4 (PDK4), and glucose-6-phosphatase (G6pase) were decreased, suggesting a dissociation relationship between steatosis and insulin resistance in the developed model. As well, the drug metabolism of this developed model was investigated and showed up-regulation of cytochrome P450 3A (CYP3A) and down-regulation of cytochrome P450 2E1 (CYP2E1) and cytochrome P450 1A2 (CYP1A2). Taken together, those results demonstrate that the in vitro model of dissociated steatosis from insulin resistance was successfully created by our co-cultured cells in high insulin and glucose medium, which will be a potential model for investigating the mechanism of insulin resistance dissociated steatosis, and discovering a novel drug for its treatment.

Ceramide de novo synthesis in non-alcoholic fatty liver disease: Pathogenic mechanisms and therapeutic perspectives

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease, and its advanced form non-alcoholic steatohepatitis (NASH) may progress to cirrhosis and hepatocellular carcinoma. Ceramides have been shown to exacerbate NAFLD development through enhancing insulin resistance, reactive oxygen species production, liver steatosis, lipotoxicity and hepatocyte apoptosis, and eventually causing hepatic inflammation and fibrosis. Emerging evidence indicates that ceramide production in NAFLD is predominantly attributed to activation of the de novo synthesis pathway of ceramides in hepatocytes. More importantly, pharmacological modulation of ceramide de novo synthesis in preclinical studies seems efficacious for the treatment of NAFLD. In this review, we provide an overview of the pathogenic mechanisms of ceramides in NAFLD, discuss recent advances and challenges in pharmacological interventions targeting ceramide de novo synthesis, and propose some research directions in the field.

Formulation and Characterization of O/W Nanoemulsions of Hemp Seed Oil for Protection from Steatohepatitis: Analysis of Hepatic Free Fatty Acids and Oxidation Markers

Non-alcoholic steatohepatitis (NASH) is a common type of metabolic liver disease which is characterized by fatty changes associated with hepatocyte injury, lobular inflammation, and/or liver fibrosis. Nanoemulsions are kinetically stable colloidal systems characterized by small droplet size. Hemp seed oil is a natural oil derived from Cannabis sativa seeds. The current study was designed to formulate nanoemulsion preparations of hemp seed oil with promising enhanced biological activity against high fat (HF) diet induced NASH in rats. Four nanoemulsion formulas (NEFs) were formulated based on high-pressure homogenization technique and evaluated for droplet size, zeta potential (ZP), polydispersity index (PDI), electrical conductivity, pH, and viscosity, as well as the preparation stability. The best NEF was selected to perform an in vivo rat study; selection was based on the smallest droplet size and highest physical stability. Results showed that NEF#4 showed the best physiochemical characters among the other preparations. Twenty male rats were assigned to four groups as follows: normal, NASH control, NASH + hemp seed oil and NASH + hemp seed oil NEF4. The rats were tested for body weight (BWt) change, insulin resistance (IR) and hepatic pathology. The hemp seed NEF#4 protected against NASH progression in rats and decreased the % of BWt gain compared to the original Hemp seed oil. NEF#4 of Hemp seed oil showed greater protective activity against experimental NASH and IR in rats. Hence, we can consider the nanoemulsion preparations as a useful tool for enhancing the biological action of the hemp seed oil, and further studies are warranted for application of this technique for preparing natural oils aiming at enhancing their activities.

Schisandrin B mitigates hepatic steatosis and promotes fatty acid oxidation by inducing autophagy through AMPK/mTOR signaling pathway

BACKGROUND

Schisandrin B (Sch B), which inhibits hepatic steatosis caused by non-alcoholic fatty liver disease (NAFLD), is one of the most active dibenzocyclooctadienes isolated from Schisandra chinensis (Turcz.) Baill with various pharmacological activities. In this study, the role of Sch B-induced autophagy in lipid-lowering activities of Sch B was examined and the underlying mechanisms were elucidated.

METHODS

Free fatty acid (FFA)-stimulated HepG2 cells and mouse primary hepatocytes (MPHs) and high-fat diet (HFD)-fed mice were used as NAFLD models. The role of Sch B-induced autophagy in lipid-lowering effects of Sch B was assessed using ATG5/TFEB-deficient cells and 3-methyladenine (3-MA)-treated hepatocytes and mice.

RESULTS

Sch B simultaneously active autophagy through AMPK/mTOR pathway and decreased the number of lipid droplets in FFA-treated HepG2 cells and MPHs. Additionally, siATG5/siTFEB transfection or 3-MA treatment mitigated Sch B-induced autophagy and activation of fatty acid oxidation (FAO) and ketogenesis in FFA-treated HepG2 cells and MPHs. Sch B markedly decreased hepatic lipid content and activated the autophagy through AMPK/mTOR pathway in HFD-fed mice. However, the activities of Sch B were suppressed upon 3-MA treatment. Sch B upregulated the expression of key enzymes involved in FAO and ketogenesis, which was mitigated upon 3-MA treatment. Moreover, changes in hepatic lipid components and amino acids may be related to the Sch B-induced autophagy pathway.

CONCLUSION

These results suggested that Sch B inhibited hepatic steatosis and promoted FAO by activation of autophagy through AMPK/mTOR pathway. Our study provides novel insights into the hepatic lipophagic activity of Sch B and its potential application in the management of NAFLD.

Quantitative proteomics analysis based on tandem mass tag labeling coupled with labeling coupled with liquid chromatography-tandem mass spectrometry discovers the effect of silibinin on non-alcoholic fatty liver disease in mice

In recent years, the beneficial effects of silibinin (SIL) on nonalcoholic fatty liver disease (NAFLD) have attracted widespread attention. We tried to study the intervention effect of SIL on NAFLD, and explore the potential mechanisms and targets of SIL on NAFLD improvement. Thirty-three male C57BL6/J mice were divided into three groups, and, respectively, fed a normal diet (ND), a high-fat diet (HFD) or a HFD given SIL treatment (HFD+SIL). Biochemical indexes and histopathological changes of mice in each group were detected. In addition, quantitative proteomics analysis based on tandem mass tag (TMT) labeling coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) and bioinformatics analysis was performed on protein changes in the livers. SIL could reduce the weight of mice, reduce liver lipid deposition, and improve glucose metabolism. Through comparison among the three experimental groups, a total of 30 overlapping proteins were found. These identified proteins were closely linked to liver lipid metabolism and energy homeostasis. Moreover, some drug targets were found, namely perilipin-2, phosphatidate phosphatase LPIN1, farnesyl pyrophosphate synthase, and glutathione S-transferase A1. In conclusions, high-fat diet increases the expressions of proteins implicated in lipid synthesis and transport in the liver, which can result in disorders of liver lipid metabolism. SIL can decrease liver lipid deposition and increase insulin sensitivity by regulating the expressions of these proteins. It not only improves the disorder of lipid metabolism in vivo, but also improves the disorder of glucose metabolism.

Ginsenoside Re Improves Inflammation and Fibrosis in Hepatic Tissue by Upregulating PPARγ Expression and Inhibiting Oxidative Stress in db/db Mice

Ginsenoside Re (Re) is the main component of “Zhenyuan Capsule” (ZYC), which was wildly used in clinic in China for adjunctive treatment of coronary heart disease (CHD) and type II diabetes (T2DM). Nonalcoholic fatty liver disease (NAFLD) is one of the most important complications of T2DM, as well as an important risk factor of CHD. The aim of the present study was to investigate the effects of Re on NAFLD in db/db mice, one of the most recognized gene deficient animal models on T2DM. Sixteen db/db mice and sixteen wild-type mice were divided into four groups and orally administered Re or placebo in equal volume. According to the results, Re showed no obvious effect on blood glucose, lipids, or body weight of db/db mice. Histology pictures of hepatic tissue showed that Re did not improve steatosis, too. However, some evidence suggested that hepatic injury in db/db mice was attenuated by Re administering. Collagen deposition and aminotransferase elevation were significantly downregulated in the DB + Re group compared to those in the DB Group. The mechanisms of the protect effects of Re represented in db/db mice with NAFLD might be inhibiting oxidative stress and the reupregulation of peroxisome proliferator-activated receptor γ (pparγ) expression. The results of this study indicated that ZYC might be able to help T2DM patients with NAFLD to control the progress of NAFLD as an alternation of thiazolidinediones, synthetic agonists of PPARγ, whose side effects and adverse events should not be ignored.

Defining NASH from a Multi-Omics Systems Biology Perspective

Non-alcoholic steatohepatitis (NASH) is a chronic liver disease affecting up to 6.5% of the general population. There is no simple definition of NASH, and the molecular mechanism underlying disease pathogenesis remains elusive. Studies applying single omics technologies have enabled a better understanding of the molecular profiles associated with steatosis and hepatic inflammation—the commonly accepted histologic features for diagnosing NASH, as well as the discovery of novel candidate biomarkers. Multi-omics analysis holds great potential to uncover new insights into disease mechanism through integrating multiple layers of molecular information. Despite the technical and computational challenges associated with such efforts, a few pioneering studies have successfully applied multi-omics technologies to investigate NASH. Here, we review the most recent technological developments in mass spectrometry (MS)-based proteomics, metabolomics, and lipidomics. We summarize multi-omics studies and emerging omics biomarkers in NASH and highlight the biological insights gained through these integrated analyses.

Role of Cholesterol-Associated Steatohepatitis in the Development of NASH

The rising prevalence of nonalcoholic fatty liver disease (NAFLD) and NAFLD-related cirrhosis in the United States and globally highlights the need to better understand the mechanisms causing progression of hepatic steatosis to fibrosing steatohepatitis and cirrhosis in a small proportion of patients with NAFLD. Accumulating evidence suggests that lipotoxicity mediated by hepatic free cholesterol (FC) overload is a mechanistic driver for necroinflammation and fibrosis, characteristic of nonalcoholic steatohepatitis (NASH), in many animal models and also in some patients with NASH. Diet, lifestyle, obesity, key genetic polymorphisms, and hyperinsulinemia secondary to insulin resistance are pivotal drivers leading to aberrant cholesterol signaling, which leads to accumulation of FC within hepatocytes. FC overload in hepatocytes can lead to ER stress, mitochondrial dysfunction, development of toxic oxysterols, and cholesterol crystallization in lipid droplets, which in turn lead to hepatocyte apoptosis, necrosis, or pyroptosis. Activation of Kupffer cells and hepatic stellate cells by hepatocyte signaling and cholesterol loading contributes to this inflammation and leads to hepatic fibrosis. Cholesterol accumulation in hepatocytes can be readily prevented or reversed by statins. Observational studies suggest that use of statins in NASH not only decreases the substantially increased cardiovascular risk, but may ameliorate liver pathology. Conclusion: Hepatic FC loading may result in cholesterol-associated steatohepatitis and play an important role in the development and progression of NASH. Statins appear to provide significant benefit in preventing progression to NASH and NASH-cirrhosis. Randomized controlled trials are needed to demonstrate whether statins or statin/ezetimibe combination can effectively reverse steatohepatitis and liver fibrosis in patients with NASH.

alpha-Tocopherol supplementation reduces inflammation and apoptosis in high cholesterol mediated nonalcoholic steatohepatitis

Inflammation and apoptosis signaling are crucial steps in the progression from nonalcoholic fatty liver disease (NAFLD) to nonalcoholic steatohepatitis (NASH). Alpha-tocopherol, the most active form of vitamin E, is an important modulator of signaling mechanisms, but its involvement to cholesterol-induced NASH pathogenesis remains poorly defined. Herein we have reported a novel effect of α-tocopherol in the transition from hepatic steatosis to NASH. High cholesterol diet alone (without α-tocopherol) in rabbits elevated NASH development as indicated by increased inflammatory response, apoptotic activity and liver fibrosis. Such elevation results from induction of signaling mechanisms since the expressions of IL1β, phospho c-Jun/c-Jun ratio, JNK, caspase 9, CHOP and Bax were increased, and recruitment of macrophage, α-smooth muscle actin (α-SMA) and COL1A1 into the liver tissue were induced. Alpha-tocopherol supplementation inhibited inflammatory response, apoptosis and fibrosis development without affecting lipid accumulation in high cholesterol-induced NASH. Specifically, α-tocopherol lowered the inflammatory level as observed by reduced macrophage infiltration and JNK/c-Jun signaling. Lower inflammatory status co-occurred with the reduction of CHOP and Bax expressions as well as fibrosis-related COL1A1 and α-SMA levels. Taken together, α-tocopherol supplementation inhibits cholesterol-induced NASH development by lowering JNK/c-Jun/inflammation axis in addition to JNK/CHOP/apoptosis signaling, which might contribute to resistance against NAFLD/NASH transition.

Metabolic analysis of early nonalcoholic fatty liver disease in humans using liquid chromatography-mass spectrometry

Background

Nonalcoholic fatty liver disease (NAFLD) is a common metabolic disease that affects 20–30% of individuals worldwide. Liver puncture remains the gold standard for the diagnosis of liver diseases despite limitations regarding invasive nature and sample variability. It is of great clinical significance to find noninvasive biomarkers to detect and predict NAFLD.

Objective

The aims of this study were to identify potential serum markers in individuals with early-stage NAFLD and to advance the mechanistic understanding of this disease using a high-throughput mass spectrometry-based untargeted metabolomics approach.

Methods

One hundred and twelve patients with early-stage NAFLD aged 18–55 were recruited according to the guidelines. The control group included 112 healthy participants. The demographic, anthropometric, clinical and laboratory data of all participants were systematically collected. Serum samples were obtained after an overnight fast. The comprehensive serum metabolomic analysis was performed by ultra-performance liquid chromatography-Orbitrap mass spectrometry. The resultant data was processed by Compound Discover and SIMCA-P software to validate the potential biomarkers. Significantly altered metabolites were evaluated by variable importance in projection value (VIP > 1) and ANOVA (p < 0.01). Pathway analysis was performed using MetaboAnalyst 4.0.

Results

The liver function test of early NAFLD patients showed no statistical differences to control group (p > 0.05). However, obvious differences in blood lipids were observed between subjects with NAFLD and controls (p < 0.001). In total, 55 metabolites showed significant changes in experimental group were identified. The area under curve (AUC) values deduced by receiver operating curve (ROC) analysis indicated that these newly identified biomarkers have high predictability and reliability. Of these, 15 metabolites with AUC greater than 0.9 were of great diagnostic value in early NAFLD patients.

Conclusion

In this study, a total of 15 serum metabolites were found to strongly associate with early NAFLD. These biomarkers may have great clinical significance in the early diagnosis of NAFLD, as well as to follow response to therapeutic interventions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-02820-7.

Ginsenoside Rg3 Attenuates Early Hepatic Injury via Inhibiting PPARγ- and Ang II-Related Inflammation and Fibrosis in Type II Diabetic Mice

Ginsenoside Rg3 (Rg3), a natural product abundantly present in Korean Red Ginseng, is widely known for its anti-tumor activity. In our previous studies, we had further demonstrated that Rg3 has protective effects on the hearts, kidneys, and aortas of animals with hypertension or hypercholesterolemia, and its main mechanisms include down-regulation of angiotensin II (Ang II) levels and activation of peroxisome proliferator-activated receptor gamma (PPARγ) pathway in those tissues. In this study, the protective effects of Rg3 on liver were determined in db/db mice, a most recognized type II diabetes (T2DM) animal model with nonalcoholic fatty liver disease (NAFLD). The results showed that Rg3 did not have obvious effects to the body weight, blood glucose, and lipids of db/db mice. According to the results of histology examination, Rg3 could not improve steatosis in the hepatic tissue, too. But Rg3 did attenuate alanine aminotransferase (ALT)/aspartate aminotransferase (AST) elevation in serum and collagen deposition in hepatic tissue. Immunohistochemistry (IHC) and enzyme-linked immunosorbent assay (ELISA) showed that Rg3 upregulated PPARγ and downregulated Ang II in hepatic tissue in db/db mice, which resulted in reducing activities of transforming growth factor β (TGF-β)/connective tissue growth factor (CTGF) pathway, downregulating the levels of inflammatory cytokines and attenuating collagen accumulation. In conclusion, although it has no obvious effect on steatosis in the hepatic tissue, Rg3 indeed attenuates early hepatic injury from NAFLD via inhibiting PPARγ- and Ang II-related inflammation and fibrosis in T2DM db/db mice. These effects are independent of reducing blood glucose and lipids, and the mechanisms are similar to the protective effects of Rg3 in hypertension and hypercholesterolemia animals in our previous studies.

Impact of apolipoprotein E genetic polymorphisms on liver disease: An essential review

Cirrhosis is an advanced stage of liver disease, compromising liver function with systemic health implications and poor quality of life. Hepatitis C virus (HCV) infection and alcoholic liver disease are the main causes of this pathology. However, since genetic factors may play a large role in the progression and severity of liver disease, and as apolipoprotein E (apoE) has been recognised to be mainly synthesised in the liver, apoE polymorphism studies are important to better understand the causal mechanisms in liver diseases. In this review, we summarise up-to-date studies addressing how apoE polymorphisms influence liver cirrhosis and liver transplantation outcomes and potential protective mechanisms. Although more clinical studies are needed to support these findings, the apoE ɛ4 allele seems to be protective against the progression of liver cirrhosis in the majority of aetiologies and the postoperative serum apoE phenotype of the transplanted subject receptors was converted to that of the donor, indicating that >90% of apoE in plasma is synthesised in the hepatic system.

The protective effects of trelagliptin on high-fat diet-induced nonalcoholic fatty liver disease in mice

Nonalcoholic fatty liver disease (NAFLD) occurs in patients with type 2 diabetes mellitus (T2DM). Trelagliptin is an important member of the Gliptins family, which has been recently licensed for the treatment of T2DM. However, the pharmacological function of trelagliptin in NAFLD has not been previously reported. In this study, we aimed to investigate the roles of trelagliptin in the development of NAFLD in a mouse model. To induce NAFLD disease, C57BL/6 mice were fed a high-fat diet for 10 weeks. Our results indicate that trelagliptin reduced plasma lipid levels in NAFLD mice by reducing triglycerides, total cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol. Treatment with trelagliptin exhibited an improvement in insulin resistance. More important, trelagliptin improved liver function by reducing alanine transaminase, aspartate transaminase, lactate dehydrogenase, and total bile acid. In addition, trelagliptin ameliorated oxidative stress in the liver of NAFLD mice by reducing malondialdehyde and increasing the levels of reduced glutathione and superoxide dismutase activity. Also, the enzyme-linked immunosorbent assay results indicate that trelagliptin-treated mice displayed anti-inflammatory properties by reducing the levels of interleukin 1β (IL-1β), IL-6, and tumor necrosis factor-α. Hematoxylin and eosin and Oil red O staining show that trelagliptin treatment ameliorates liver tissue damage and hepatic lipid deposition. Mechanistically, we found that the administration of trelagliptin reduced the activity of hepatic nuclear factor-κB but increased the activity of AMP-activated protein kinase. These findings suggest that trelagliptin might become a promising therapeutic agent for the treatment of NAFLD.

The GLP-1R agonist liraglutide limits hepatic lipotoxicity and inflammatory response in mice fed a methionine-choline deficient diet

Nonalcoholic fatty liver disease (NAFLD) is the most common hepatic disorder related to type 2 diabetes (T2D). The disease can evolve toward nonalcoholic steatohepatitis (NASH), a state of hepatic inflammation and fibrosis. There is presently no drug that effectively improves and/or prevents NAFLD/NASH/fibrosis. GLP-1 receptor agonists (GLP-1Ra) are effective in treating T2D. As with the endogenous gut incretins, GLP-1Ra potentiate glucose-induced insulin secretion. In addition, GLP-1Ra limit food intake and weight gain, additional beneficial properties in the context of obesity/insulin-resistance. Nevertheless, these pleiotropic effects of GLP-1Ra complicate the elucidation of their direct action on the liver. In the present study, we used the classical methionine-choline deficient (MCD) dietary model to investigate the potential direct hepatic actions of the GLP-1Ra liraglutide. A 4-week infusion of liraglutide (570 µg/kg/day) did not impact body weight, fat accretion or glycemic control in MCD-diet fed mice, confirming the suitability of this model for avoiding confounding factors. Liraglutide treatment did not prevent lipid deposition in the liver of MCD-fed mice but limited the accumulation of C16 and C24-ceramide/sphingomyelin species. In addition, liraglutide treatment alleviated hepatic inflammation (in particular accumulation of M1 pro-inflammatory macrophages) and initiation of fibrosis. Liraglutide also influenced the composition of gut microbiota induced by the MCD-diet. This included recovery of a normal Bacteroides proportion and, among the Erysipelotrichaceae family, a shift between Allobaculum and Turicibacter genera. In conclusion, liraglutide prevents accumulation of C16 and C24-ceramides/sphingomyelins species, inflammation and initiation of fibrosis in MCD-diet-fed mice liver, suggesting beneficial hepatic actions independent of weight loss and global hepatic steatosis.

Calorie-Restricted Mediterranean and Low-Fat Diets Affect Fatty Acid Status in Individuals with Nonalcoholic Fatty Liver Disease

Lifestyle modifications are the main support of nonalcoholic fatty liver disease (NAFLD) therapy. Weight loss is one of the primary goals in NAFLD, but the effects of different calorie-restricted diets remain unclear. Thus, we evaluated the effects of two calorie-restricted diets—the Mediterranean diet (Med diet) and low-fat diet—on liver status, cardiometabolic markers, and fatty acid profiles in patients with NAFLD. Twenty-four overweight/moderately obese men were randomly assigned to consume one of these diets. Lipid levels, glucose, insulin, liver enzymes, steatosis, and fatty acid profiles of serum and erythrocytes phospholipids were assessed. After 3 months, all participants had a significant weight loss (>9%), with improvements in waist circumference, body fat %, index of visceral adiposity (VAI), lipid accumulation product, fatty liver (FLI), and hepatic steatosis (HSI) index (p < 0.001). Both diets significantly lowered triglycerides, total and LDL-cholesterol, liver enzymes, fasting glucose, insulin, and HOMA-IR index. Fatty acid profiles were enhanced after both diets, with a significantly decreased n-6/n-3 ratio. Participants on the Med diet had higher levels of HDL-cholesterol and monounsaturated and n-3 docosahexaenoic acids in serum phospholipids and lower levels of saturated fatty acids, triglycerides, TG/HDL ratio, and FLI when compared to participants on the low-fat diet. Our results indicate that dietary patterns and calorie restriction represent central therapeutic issues in the improvement of obesity-related cardiometabolic alterations that are involved in the mechanism of hepatic steatosis. The Med diet may contribute to disease treatment even more than the low-fat diet since it leads to decreased saturated and increased monounsaturated and n-3 polyunsaturated fatty acid status and improved FLI in NAFLD patients.

Hugan Qingzhi medication ameliorates free fatty acid-induced L02 hepatocyte endoplasmic reticulum stress by regulating the activation of PKC-δ

Background

Previous studies have found that Hugan Qingzhi tablet (HQT) has significant lipid-lowering and antioxidant effects on non-alcoholic fatty liver disease (NAFLD). Moreover, the results of proteomic analysis confirmed that various proteins in endoplasmic reticulum stress (ERS) pathway were activated and recovered by HQT. However, its mechanism remains confused. The purpose of this study was to explore the effects of HQT-medicated serum on hepatic ERS and its relevant mechanisms.

Methods

L02 cells were induced by Free Fatty Acid (FFA) for 24 h to establish a model of hepatic ERS and pretreated with the drug-medicated rat serum for 24 h. Accumulation of intracellular lipid was evaluated using Oil Red O staining and Triglyceride detection kit. The morphological changes of ER were observed by TEM. PKC-δ was silenced by specific siRNA. Western blot and RT-qPCR were applied to detect the expression of markers related to ERS, calcium disorder, steatosis and insulin resistance. The fluorescence of Ca²⁺ influx was recorded using fluorescence spectrophotometer.

Results

HQT-medicated serum significantly decreased the intracellular TG content. Furthermore, it caused significant reduction in the expression of ERS markers and an improvement in ER structure of L02 cells. PKC-δ was activated into phosphorylated PKC-δ in FFA-induced L02 hepatocytes while these changes can be reversed by HQT-medicated serum. Silencing PKC-δ in L02 cells can restore the expression and activity of SERCA2 in ER and down-regulate the expression of IP3R protein to maintain intracellular calcium homeostasis, so as to relieve FFA-induced ERS and its lipid accumulation and insulin resistance.

Conclusions

The results concluded that HQT-medicated serum exerts protective effects against hepatic ERS, steatosis and insulin resistance in FFA-induced L02 hepatocyte. And its potential mechanism might be down-regulating the activation of PKC-δ and stabilization of intracellular calcium.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-020-03164-3.

Effect of the dietary combination of flaxseed and Ricinodendron heudelotii or Punica granatum seed oil on the fatty acid profile of eggs

The health promoting omega-3, -7, and -5 fatty acids, α-linolenic acid (ALA), docosahexaenoic acid (DHA), rumenic acid (RmA), and α-eleostearic acid (α-ESA)/punicic acid (PunA), are not currently combined in frequently consumed food items. We have evaluated the impact of supplementing laying hens' feeds with flaxseeds combined with oil derived from seeds of either Ricinodendron heudelotii, an α-ESA source, or Punica granatum, a PunA source, on the egg fatty acid profile. The supplemented diets increased the egg content in ALA, DHA, RmA, as well as α-ESA or PunA. The combination of dietary lipids did not affect the conversion rate of ALA into DHA. Hens fed on R. heudelotii or P. granatum seed oil both accumulated RmA in egg yolk, indicating an efficient conversion from the α-ESA or PunA precursors through a Δ-13 reductase activity. The accumulation of PunA in eggs was largely higher than that of α-ESA.

High Dietary Intake of Vegetable or Polyunsaturated Fats Is Associated With Reduced Risk of Hepatocellular Carcinoma

BACKGROUND & AIMS

We investigated associations of intake of total fats, specific dietary fats, and fats from different food sources with risk of hepatocellular carcinoma (HCC) using data from the Nurses' Health Study (NHS) and the Health Professionals Follow-up Study (HPFS).

METHODS

We analyzed data from a total of 138,483 women and men who participated in the NHS or HPFS. A validated semi-quantitative food frequency questionnaire was sent to NHS participants in 1980, 1984, 1986, and every 4 years thereafter; dietary information was collected from participants in the HPFS in 1986 and every 4 years thereafter. Multivariable hazard ratios (HRs) and 95% CIs were estimated using Cox proportional hazards regression.

RESULTS

After an average follow-up time of 26.6 years, 160 incident HCC cases were documented. Although there was a non-significant association between total fat intake and HCC, intake of vegetable fats reduced risk of HCC (HR for the highest vs lowest quartile, 0.61; 95% CI, 0.39-0.96; Ptrend = .02), but not animal or dairy fats. Replacing animal or dairy fats with an equivalent amount of vegetable fats was associated with a lower risk of HCC (HR per 1 standard deviation, 0.79; 95% CI, 0.65-0.97). Among fat subtypes, monounsaturated and polyunsaturated fatty acids, including n-3 (HR, 0.63; 95% CI, 0.41-0.96; Ptrend = .14) and n-6 polyunsaturated fatty acids (HR, 0.54; 95% CI, 0.34-0.86; Ptrend = .02), were inversely associated with risk of HCC. Higher ratios of monounsaturated or polyunsaturated fat to saturated fat were inversely associated with HCC risk (all Ptrend ≤ .02). In addition, when replacing saturated fats with monounsaturated or polyunsaturated fats, the HR per 1 standard deviation was 0.77 (95% CI, 0.64-0.92).

CONCLUSIONS

In an analysis of data from 2 large cohort studies, we found higher intake of vegetable fats and polyunsaturated fats to be associated with lower risk of HCC. Replacing animal or dairy fats with vegetable fats, or replacing saturated fats with monounsaturated or polyunsaturated fats, was associated with reduced risk of HCC.

History of Nonalcoholic Fatty Liver Disease

Based on the assumption that characterizing the history of a disease will help in improving practice while offering a clue to research, this article aims at reviewing the history of nonalcoholic fatty liver disease (NAFLD) in adults and children. To this end, we address the history of NAFLD histopathology, which begins in 1980 with Ludwig's seminal studies, although previous studies date back to the 19th century. Moreover, the principal milestones in the definition of genetic NAFLD are summarized. Next, a specific account is given of the evolution, over time, of our understanding of the association of NAFLD with metabolic syndrome, spanning from the outdated concept of "NAFLD as a manifestation of the Metabolic Syndrome", to the more appropriate consideration that NAFLD has, with metabolic syndrome, a mutual and bi-directional relationship. In addition, we also report on the evolution from first intuitions to more recent studies, supporting NAFLD as an independent risk factor for cardiovascular disease. This association probably has deep roots, going back to ancient Middle Eastern cultures, wherein the liver had a significance similar to that which the heart holds in contemporary society. Conversely, the notions that NAFLD is a forerunner of hepatocellular carcinoma and extra-hepatic cancers is definitely more modern. Interestingly, guidelines issued by hepatological societies have lagged behind the identification of NAFLD by decades. A comparative analysis of these documents defines both shared attitudes (e.g., ultrasonography and lifestyle changes as the first approaches) and diverging key points (e.g., the threshold of alcohol consumption, screening methods, optimal non-invasive assessment of liver fibrosis and drug treatment options). Finally, the principal historical steps in the general, cellular and molecular pathogenesis of NAFLD are reviewed. We conclude that an in-depth understanding of the history of the disease permits us to better comprehend the disease itself, as well as to anticipate the lines of development of future NAFLD research.

Lack of FGF21 promotes NASH-HCC transition via hepatocyte-TLR4-IL-17A signaling

Rationale: Hepatocellular carcinoma (HCC) has been increasingly recognized in nonalcoholic steatohepatitis (NASH) patients. Fibroblast growth factor 21 (FGF21) is reported to prevent NASH and delay HCC development. In this study, the effects of FGF21 on NASH progression and NASH-HCC transition and the potential mechanism(s) were investigated. Methods: NASH models and NASH-HCC models were established in FGF21Knockout (KO) mice to evaluate NASH-HCC transition. IL-17A signaling was investigated in the isolated hepatic parenchymal cells, splenocytes, and hepatocyte and HCC cell lines. Results: Lack of FGF21 caused significant up-regulation of the hepatocyte-derived IL-17A via Toll-like receptor 4 (TLR4) and NF-κB signaling. Restoration of FGF21 alleviated the high NAFLD activity score (NAS) and attenuated the TLR4-triggered hepatocyte-IL-17A expression. The HCC nodule number and tumor size were significantly alleviated by treatments of anti-IL-17A antibody. Conclusion: This study revealed a novel anti-inflammatory mechanism of FGF21 via inhibiting the hepatocyte-TLR4-IL-17A signaling in NASH-HCC models. The negative feedback loop on the hepatocyte-TLR4-IL-17A axis could be a potential anti-carcinogenetic mechanism for FGF21 to prevent NASH-HCC transition.

The fatty acid profile of adipose tissue as a predictor of the ponderal and inflammatory response in adult women six years after bariatric surgery

Background

Adipose tissue is involved in several metabolic changes. This study investigated the association between the fatty acid (FA) composition of subcutaneous (SAT) and visceral (VAT) adipose tissue pre-surgery and the postsurgical response regarding the evolution of weight and concentrations of tumour necrosis factor alpha (TNF) and interleukin 6 (IL-6) in adult women who underwent Roux-en-Y gastric bypass (RYGB, n = 14) or sleeve gastrectomy (SG, n = 19) at one (T1), three (T3) and six (T6) years after surgery.

Methods

Blood samples were collected to obtain plasma for the measurement of IL-6 and TNF. Anthropometric measurements were performed, collecting samples of VAT and SAT during surgery to assess the FA profiles.

Results

Weight loss had a positive correlation with the percentage of VAT-C17:0 (T1, T3) and SAT-C18:2 (T1, T3, T6), and it had a negative correlation with SAT-C22:0 (T1, T3) and VAT-C22:0 (T3). Regarding the inflammatory response, SAT-C14:0 (T6), VAT-C14:0 (T6), SAT-C14:1 (baseline), SAT-C15:0 (T6), SAT-C16:1 (T6), VAT-C16:1 (baseline), SAT-C17:1 (T6), VAT-C17:1 (baseline), VAT-C18:1 (T6), and VAT-C20:1 (T6) exhibited positive correlations with the concentration of IL-6, which were different from the correlations of IL-6 concentrations with SAT-C18:2, VAT-C18:2 (T6), and VAT-C18:3 (T6). The FA SAT-C18:0 (T1) was negatively correlated with TNF concentrations.

Conclusions

Saturated FAs were predominantly proinflammatory, primarily in the late postoperative period. Alternately, the polyunsaturated FAs exhibited anti-inflammatory potential and predicted weight loss. Thus, the FA profile of the adipose tissue of obese adult women may be a predictor of the ponderal and inflammatory response 6 years after bariatric surgery.

Trial registration

This study was approved by the ethics committee of Federal University of Viçosa; Registration n. 17287913.2.0000.5153; Date: 07/05/2013.

Curcuma longa and Trigonella foenum graecum-enriched nutrient mixture from germinated Macrotyloma uniflorum and Vigna radiate ameliorate nonalcoholic fatty liver diseases in rats

The prevalence of nonalcoholic fatty liver is increasing due to modern lifestyle. Germinated and dehulled Macrotyloma uniflorum and Vigna radiate were shown to have enhanced nutrients. Curcuma longa and Trigonella foenum graecum were proven hepatoprotective.The supplementation of the nutrient herbal mixture to the MCD diet-induced steatosis shows reduced hepatic fat accumulation and lipid profile, and liver injury markers in serum also reserved in normal. Increased serum albumin in the treatment group indicates that the liver function is enhanced than that of steatosis. The supplementation of the herbal mixture has preserved the hepatic antioxidant. Zymographic analysis of matrix metalloproteinase, western blot determination of α-SMA, and histological evolution (H&E, Sirius red) depicted reduced fibrosis and reveled management of hepatic stellate cells in quiescent form. The present study concludes that the herbal mixture has reduced hepatocyte fat accumulation in steatotic animals, and curtailed the oxidative stress, further it prevents the progression of steatohepatitis. PRACTICAL APPLICATIONS: Fatty liver diseases can be treated by modulating the diet composition such as consuming food rich in the nutrient herbal mixture. In this study, the nutrient mixture was made with dynamic food processing techniques such as germination, dehulling, and milling to augment the nutritional contents. Besides, Macrotyloma uniflorum, Vigna radiate, Curcuma longa, and Trigonella foenum graecum were used to improve the medicinal value and antioxidant. This formulation could target the various stages of NAFLD. This study revealed that the nutrient herbal mixture reduces the steatosis of the liver and curtailed the progression of steatohepatitis from hepatic steatosis. Since the edible foodstuff was used to make the nutrient mixture, it has excellent clinical application.

Bariatric Surgery in Cirrhotic Patients: Is It Safe?

Introduction

Ten percent of cirrhotic patients are known to have a high risk of postoperative complications. Ninety percent of bariatric patients suffer from non-alcoholic fatty liver disease (NAFLD), and 50% of them may develop non-alcoholic steatohepatitis (NASH) which can progress to cirrhosis. The aim of this study was to assess whether the presence of cirrhosis at the time of bariatric surgery is associated with an increased rate and severity of short- and long-term cirrhotic complications.

Methods

A cohort of 110 bariatric patients, between May 2003 and February 2018, who had undergone liver biopsy at the time of bariatric surgery were reassessed for histological outcome and divided into two groups based on the presence (C, n = 26) or absence (NC, n = 84) of cirrhosis. The NC group consisted of NASH (n = 49), NAFLD (n = 24) and non-NAFLD (n = 11) liver histology. Medical notes were retrospectively assessed for patient characteristics, development of 30-day postoperative complications, severity of complications (Clavien-Dindo (CD) classification) and length of stay. The C group was further assessed for long-term cirrhosis-related outcomes.

Results

The C group was older (52 years vs 43 years) and had lower BMI (46 kg/m2 vs 52 kg/m2) and weight (126 kg vs 145 kg) compared to the NC group (p < 0.05). The C group had significantly higher overall complication rate (10/26 vs 14/84, p < 0.05) and severity of complications (CD class ≥ III, 12% vs 7%, p < 0.05) when compared to the NC group. The length of stay was similar between the two groups (5 days vs 4 days). The C group had significant improvement in model end-stage liver disease scores (7 vs 6, p < 0.01) with median follow-up of 4.5 years (range 2–11 years). There were no long-term cirrhosis-related complications or mortality in our studied cohort (0/26).

Conclusion

Bariatric surgery in cirrhotic patients has a higher risk of immediate postoperative complications. Long-term cirrhosis-related complications or mortality was not increased in this small cohort. Preoperative identification of liver cirrhosis may be useful for risk stratification, optimisation and informed consent. Bariatric surgery in well-compensated cirrhotic patients may be used as an aid to improve long-term outcome.

Serial Plasma Phospholipid Fatty Acids in the De Novo Lipogenesis Pathway and Total Mortality, Cause-Specific Mortality, and Cardiovascular Diseases in the Cardiovascular Health Study

Background Synthesized fatty acids (FAs) from de novo lipogenesis may affect cardiometabolic health, but longitudinal associations between serially measured de novo lipogenesis-related fatty acid biomarkers and mortality or cardiovascular disease (CVD) are not well established. Methods and Results We investigated longitudinal associations between de novo lipogenesis-related fatty acids with all-cause mortality, cause-specific mortality, and incident CVD among 3869 older US adults, mean (SD) age 75 (5) years and free of prevalent CVD at baseline. Levels of plasma phospholipid palmitic (16:0), palmitoleic (16:1n-7), stearic (18:0), oleic acid (18:1n-9), and other risk factors were serially measured at baseline, 6 years, and 13 years. All-cause mortality, cause-specific mortality, and incident fatal and nonfatal CVD were centrally adjudicated. Risk was assessed in multivariable-adjusted Cox models with time-varying FAs and covariates. During 13 years, median follow-up (maximum 22.4 years), participants experienced 3227 deaths (1131 CVD, 2096 non-CVD) and 1753 incident CVD events. After multivariable adjustment, higher cumulative levels of 16:0, 16:1n-7, and 18:1n-9 were associated with higher all-cause mortality, with extreme-quintile hazard ratios (95% CIs) of 1.35 (1.17-1.56), 1.40 (1.21-1.62), and 1.56 (1.35-1.80), respectively, whereas higher levels of 18:0 were associated with lower mortality (hazard ratio=0.76; 95% CI=0.66-0.88). Associations were generally similar for CVD mortality versus non-CVD mortality, as well as total incident CVD. Changes in levels of 16:0 were positively, and 18:0 inversely, associated with all-cause mortality (hazard ratio=1.23, 95% CI=1.08-1.41; and hazard ratio=0.78, 95% CI=0.68-0.90). Conclusions Higher long-term levels of 16:0, 16:1n-7, and 18:1n-9 and changes in 16:0 were positively, whereas long-term levels and changes in 18:0 were inversely, associated with all-cause mortality in older adults.

Dietary Supplementation with Hazelnut Oil Reduces Serum Hyperlipidemia and Ameliorates the Progression of Nonalcoholic Fatty Liver Disease in Hamsters Fed a High-Cholesterol Diet

Objective: Hazelnut oil (HO) is rich in monounsaturated fatty acids and polyunsaturated fatty acids. This study intended to analyze the effects of hazelnut oil supplementation on the serum lipid profile and nonalcoholic fatty liver disease in hamsters fed a high-cholesterol (HC) diet. Methods: Hamsters were fed a basic diet (control group) and an HC diet (HC group) for 16 weeks (n = 10 in each group). Hamsters were fed an HC diet for four weeks to induce hyperlipidemia and were then fed an HC diet enriched with 5% (low-dose HC + HO group; n = 10) and 10% HO (high-dose HC + HO group; n = 10) for 12 weeks. Serum lipid levels, hepatic changes (including steatosis, inflammation, and fibrosis), and hepatic prooxidant-antioxidant status (malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione S-transferase (GST)) were evaluated after the treatment period. Results: Hamsters in the control group showed normal serum lipid profiles, normal liver function, and moderate glycogen storage without hepatic steatosis. Hamsters in the HC group showed severe hyperlipidemia, severe hepatic steatosis, and moderate steatohepatitis (mononuclear cell and neutrophil infiltration, oval cell hyperplasia, and fibrosis). Compared to the HC group, both the low-dose and the high-dose HC + HO groups showed a significant reduction of hyperlipidemia (serum triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and very-low-density lipoprotein cholesterol (VLDL-C levels)) and improved liver function (serum glutamic-oxaloacetic transaminase (SGOT) and serum glutamic pyruvic transaminase (SGPT)). Additionally, compared to the HC group, intrahepatic triglyceride accumulation (IHTC) was significantly higher in the HC + HO group, while the incidence of steatohepatitis was significantly lower. The intake of the HC diet was associated with a higher level of lipid peroxidation (malondialdehyde, MDA) and a lower concentration of hepatic antioxidant enzymes (SOD, GPx, and GST), and all these factors were partially improved in the low-dose and high-dose HC + HO groups. Conclusions: Our findings indicate that the intake of HO reduced serum hyperlipidemia and oxidative stress and ameliorated the progression of nonalcoholic fatty liver disease in hamsters fed a high-cholesterol diet.

Ameliorative effect of docosahexaenoic acid on hepatocyte apoptosis and inflammation induced by oleic acid in grass carp, Ctenopharyngodon idella

Our previous study has shown that overload of lipid accumulation results in cell apoptosis and inflammation in grass carp (Ctenopharyngodon idella). In this study, we investigated the potential protective effects of docosahexaenoic acid (DHA) on inhibiting oleic acid (OA)-induced apoptosis and inflammation in grass carp hepatocytes. Firstly, the hepatocyte of grass carp were treated with OA (800 μM) and different concentration (0, 50, 100 and 200 μM) of DHA for 24 h, the apoptotic ratio, gene expression levels of apoptosis such as caspase 3, caspase 8, and caspase 9, protein levels of Caspase3, and mRNA levels of inflammation genes such as nf-kb, tnf-α, and il-8 were detected. Furthermore, the mRNA levels of lipogenesis genes srebp1c, fas, acc, and scd and a key enzyme of lipolysis Atgl were also detected. These results showed that the cell apoptosis and the inflammation increased by OA were significantly attenuated by DHA (P < 0.05). Furthermore, DHA could significantly decrease fatty acid synthesis gene expression levels which were induced by OA (P < 0.05). However, the hepatocytes exposed with DHA had no significant influence on the expression of Atgl. Taken together, the study indicated that DHA protects the hepatocytes against apoptosis and inflammation induced by OA might via inhibiting fatty acid synthesis, instead of promoting lipolysis. These results call for further studies to assess the effectiveness of DHA.

Liver tumorigenesis is promoted by a high saturated fat diet specifically in male mice and is associated with hepatic expression of the proto-oncogene Agap2 and enrichment of the intestinal microbiome with Coprococcus

Liver cancer results in a high degree of mortality, especially among men. As fatty liver disease is a risk factor for development of hepatocellular carcinoma, we investigated the role of dietary fat type in tumor promotion by high-fat diets in mice after initiation with the chemical carcinogen diethyl nitrosamine. Tumor incidence and multiplicity were significantly greater in males than those in females. In males, fat type had complex effects on tumorigenesis. Preneoplastic foci were most prevalent in mice fed a polyunsaturated fat diet enriched in docosahexaenoic acid, whereas carcinomas and large visible liver tumors were significantly greater in mice fed a saturated fat diet made with cocoa butter relative to mice fed mono- or polyunsaturated fats. Different mechanisms thus seemed involved in early and late tumor promotion. The hepatic transcriptome and gut microbiome were assessed for traits associated with tumorigenesis. Hepatic expression of more than 20% of all genes was affected by sex, whereas fat type affected fewer genes. In males, the saturated fat diet induced expression of the proto-oncogene Agap2 and affected the expression of several cytochrome P450 genes, and genes involved in lipid, bile acid and fatty acid metabolism. The gut microbiome had a higher level of genus Akkermansia and a lower level of Firmicutes in females than in males. Males fed saturated fat had an altered microbiome, including an enrichment of the genus Coprococcus. In conclusion, sex and the dietary fat type affect the gut microbiome, the hepatic transcriptome and ultimately hepatic tumor growth.

Regulatory Non-coding RNAs Network in Non-alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) spectrum comprises simple steatosis and non-alcoholic steatohepatitis (NASH) that can lead to fibrosis and cirrhosis. The patients usually have no history of excessive alcohol consumption and other etiologies that can cause fatty liver. Understanding of the pathophysiology of NAFLD has revealed that non-coding RNAs (ncRNAs) play significant roles in modulating the disease susceptibility, pathogenesis and progression. Currently, the ncRNAs are grouped according to their sizes and their regulatory or housekeeping functions. Each of these ncRNAs has a wide range of involvement in the regulation of the genes and biological pathways. Here, we briefly review the current literature the regulatory ncRNAs in NAFLD pathogenesis and progression, mainly the microRNAs, long non-coding RNAs and circular RNAs. We also discuss the co-regulatory functions and interactions between these ncRNAs in modulating the disease pathogenesis. Elucidation of ncRNAs in NAFLD may facilitate the identification of early diagnostic biomarkers and development of therapeutic strategies for NAFLD.

Paradoxical Roles of Oxidative Stress Response in the Digestive System before and after Carcinogenesis

Oxidative stress is recognized as a cancer-initiating stress response in the digestive system. It is produced through mitochondrial respiration and induces DNA damage, resulting in cancer cell transformation. However, recent findings indicate that oxidative stress is also a necessary anticancer response for destroying cancer cells. The oxidative stress response has also been reported to be an important step in increasing the anticancer response of newly developed molecular targeted agents. Oxidative stress might therefore be a cancer-initiating response that should be downregulated in the precancerous stage in patients at risk of cancer but an anticancer cell response that should not be downregulated in the postcancerous stage when cancer cells are still present. Many commercial antioxidant agents are marketed as “cancer-eliminating agents” or as products to improve one’s health, so cancer patients often take these antioxidant agents. However, care should be taken to avoid harming the anticancerous oxidative stress response. In this review, we will highlight the paradoxical effects of oxidative stress and antioxidant agents in the digestive system before and after carcinogenesis.

Sleeve gastrectomy attenuates high fat diet-induced non-alcoholic fatty liver disease

Background

A high-fat diet (HFD) is known to lead to obesity, and contributes to the progression of non-alcoholic fatty liver disease. The objective of this study was to evaluate the effects of sleeve gastrectomy (SG) on the progression of HFD-induced hepatic steatosis.

Methods

Fifteen 4-week-old, male Wistar rats were randomly assigned into three groups: NC, HFD + SHAM and HFD + SG. Their body weight, glucose-lipid metabolism, inflammation indices, hepatic steatosis and fibroblast growth factor 21 (FGF21) levels were measured.

Results

Postoperatively, body weights in the HFD + SHAM and HFD + SG group rats decreased during the first week. Thereafter, HFD + SG rats regained their body weight. Differences in insulin, homeostasis model assessment of insulin resistance, triglyceride, free fatty acid, tumor necrosis factor-α and monocyte chemotactic protein-1 levels were statistically significant across the three groups (all P < 0.05). Interestingly, FGF21 levels in the HFD + SG group were markedly lower than in the HFD + SHAM group (P = 0.015), however, there were no differences in the NC group. Hematoxylin and eosin staining demonstrated that more vacuoles were present in the HFD + SHAM liver when compared to the HFD + SG liver. Oil-red O staining showed less red dots in the HFD + SG liver.

Conclusions

Despite eating, surgical re-routing of the gut may prevent weight accumulation, regulate glucose-lipid metabolism and insulin sensitivity, control a chronic inflammatory state, change the secretion pattern of FGF21 and alleviate the severity of fatty liver.

NLRP3 Inflammasome and IL-33: Novel Players in Sterile Liver Inflammation

In sterile liver inflammation, danger signals are released in response to tissue injury to alert the immune system; e.g., by activation of the NLRP3 inflammasome. Recently, IL-33 has been identified as a novel type of danger signal or “alarmin”, which is released from damaged and necrotic cells. IL-33 is a pleiotropic cytokine that targets a broad range of immune cells and exhibits pro- and anti-inflammatory properties dependent on the disease. This review summarizes the immunomodulatory roles of the NLRP3 inflammasome and IL-33 in sterile liver inflammation and highlights potential therapeutic strategies targeting these pathways in liver disease.