n-3 polyunsaturated fatty acids worsen inflammation and fibrosis in experimental nonalcoholic steatohepatitis

Transcriptome analysis in various cell lines exposed to nitric oxide

Nitric oxide (NO) plays a physiological role in signal transduction and excess or chronic NO has toxic effects as an inflammatory mediator. NO reversibly forms protein S-nitrosylation and exerts toxicological functions related to disease progression. DNA methyltransferases, epigenome-related enzymes, are inhibited in enzymatic activity by S-nitrosylation. Therefore, excess or chronic NO exposure may cause disease by altering gene expression. However, the effects of chronic NO exposure on transcriptome are poorly understood. Here, we performed transcriptome analysis of A549, AGS, HEK293T, and SW48 cells exposed to NO (100 μM) for 48 hr. We showed that the differentially expressed genes were cell-specific. Gene ontology analysis showed that the functional signature of differentially expressed genes related to cell adhesion or migration was upregulated in several cell lines. Gene set enrichment analysis indicated that NO stimulated inflammation-related gene expression in various cell lines. This finding supports previous studies showing that NO is closely involved in inflammatory diseases. Overall, this study elucidates the pathogenesis of NO-associated inflammatory diseases by focusing on changes in gene expression.

Refined mackerel oil increases hepatic lipid accumulation and reduces choline and choline-containing metabolites in the liver tissue in mice fed a Western diet

In this study, we aimed to evaluate the impact of consuming refined mackerel oil (MO) from rest raw material on hepatic fat accumulation, glucose tolerance, and metabolomic changes in the liver from male C57BL/6N mice. The mice were fed either a Western diet (WD) or a chow diet, with 30 g or 60 g MO per kg of diet (3% or 6%) for 13 weeks. Body weight, energy intake, and feed efficiency were monitored throughout the experiment. A glucose tolerance test was conducted after 11 weeks, and metabolomic analyses of the liver were performed at termination. Inclusion of MO in the WD, but not in the chow diet, led to increased liver weight, hepatic lipid accumulation, elevated fasting blood glucose, reduced glucose tolerance, and insulin sensitivity. Hepatic levels of eicosapentaenoic and docosahexaenoic acid increased, but no changes in levels of saturated and monounsaturated fatty acids were observed. The liver metabolomic profile was different between mice fed a WD with or without MO, with a reduction in choline ether lipids, phosphatidylcholines, and sphingomyelins in mice fed MO. This study demonstrates that supplementing the WD, but not the chow diet, with refined MO accelerates accumulation of hepatic fat droplets and negatively affects blood glucose regulation. The detrimental effects of supplementing a WD with MO were accompanied by increased fat digestibility and overall energy intake, and lower levels of choline and choline-containing metabolites in liver tissue.

Dietary linoleic acid and the ratio of unsaturated to saturated fatty acids are inversely associated with significant liver fibrosis risk: A nationwide survey

Since no pharmaceuticals have been proven to effectively reduce liver fibrosis, dietary fatty acids may be beneficial as one of the non-pharmaceutical interventions due to their important roles in liver metabolism. In this cross-sectional study, we analyzed the data from the 2017–2018 cycle of National Health and Nutrition Examination Survey to examine the associations between the proportion and composition of dietary fatty acid intakes with significant liver fibrosis among US population. The dietary fatty acid consumptions were calculated based on two 24-h dietary recalls. Significant liver fibrosis was diagnosed based on liver stiffness measurement value derived from the vibration controlled transient elastography. Multivariate logistic regression analysis and sensitivity analysis were performed to assess the association between dietary fatty acid consumption and significant liver fibrosis risk. Finally, restricted cubic spline analysis was carried out to explore the dose–response between polyunsaturated fatty acids (PUFA) or linoleic acid intakes and the risk of significant liver fibrosis. The results showed that the multivariate adjusted odds ratios (95% confidence intervals) of significant liver fibrosis were 0.34 (0.14–0.84), 0.68 (0.50–0.91), and 0.64 (0.47–0.87) for the highest level of unsaturated to saturated fatty acid ratio, dietary PUFA, and linoleic acid intakes compared to the lowest reference, respectively. The sensitivity analysis and restricted cubic spline analysis produced similar results, reinforcing the inverse association of unsaturated to saturated fatty acid ratio, PUFA, and linoleic acid consumptions with significant liver fibrosis risk. However, other dietary fatty acids did not show the statistically significant association with significant liver fibrosis. In conclusion, dietary linoleic acid may play a key role in the inverse association between the unsaturated to saturated fatty acid ratio and the risk of significant liver fibrosis. Further studies are needed to confirm these findings.

Dietary consumption and serum pattern of bioactive fatty acids in NAFLD patients

INTRODUCTION AND OBJECTIVES

Nonalcoholic fatty liver disease (NAFLD) is the hepatic manifestation of metabolic syndrome. Some dietary fatty acids have showed different bioactive functions in metabolic syndrome. The aim of this study is to determine the dietary consumption patterns and serum percentage of bioactive fatty acids in NAFLD patients.

PATIENTS AND METHODS

Cross-sectional study with NAFLD patients and non-NAFLD patients. Dietary consumption of bioactive fatty acids was assessed by a food frequency questionnaire. NAFLD and liver fibrosis were diagnosed by transient elastography. The identification of serum bioactive fatty acids was achieved by gas chromatography-mass spectrometry (%). Bioactive fatty acids consumption was correlated with NAFLD clinical characteristics with the Spearman correlation analysis.

RESULTS

A total of 299 patients were included, whose mean of age and body mass index were 44.2±9.9 years and 25.9±3.8kg/m², respectively. The consumption of bioactive fatty acids was no different regarding the presence of NAFLD; however, the consumption of stearic and linoleic fatty acids was higher in relation with NAFLD severity (p≤0.05). The consumption of myristic acid was higher in patients with fibrosis (p=0.02). Serum percentage and dietary consumption did not show correlations.

CONCLUSION

Dietary consumption of bioactive fatty acids is different according to NAFLD severity. Individualized diets according to NAFLD severity could be successful in order to prevent liver injury-related outcomes.

Efficacy of Coccinia grandis against monosodium glutamate induced hepato-cardiac anomalies by inhibiting NF-kB and caspase 3 mediated signalling in rat model

Since prehistoric times Coccinia grandis has been used as traditional medicine for various diseases including diabetes, dyslipidemia, metabolic and digestive disorders. Although the rationality of efficacy as natural antioxidants with different bioactive compounds in Coccinia grandis against monosodium glutamate (MSG) induced hepato-cardiac damage remains to be disclosed. Six different solvent extracts of the leaves of Coccinia grandis were chosen to evaluate in vitro antioxidant and free radical (FR)-scavenging activity. Due to high antioxidant content and FR-scavenging property of ethanol extract of Coccinia grandis leaves (EECGL) and presence of different bioactive compounds in EECGL was further tested to evaluate in vivo hepato-protective and cardio-protective efficacy against MSG-induced anomalies. MSG-induced dyslipidemia, increased cell toxicity markers altered functional status and histopathological peculiarities of target organs were blunted by EECGL. Additionally, MSG incited increase level of interleukin (IL)-6, tumour necrosis factor (TNF)-α, IL-1β which activates nuclear factor kappa-B (NF-kB) guided inflammation via down regulation of IL-10; impaired redox-homeostasis subsequently promoted inflammation associated oxidative stress (OS) and increased vascular endothelial growth factor (VEGF) which provoked microvascular proliferation related cellular damage. On the contrary, increased lipid peroxidation and nitric oxide promotes reduced cell viability, deoxyribonucleic acid damage and apoptosis via activation of caspase 3. EECGL significantly reduced MSG-induced inflammation mediated OS and apoptosis via inhibition of pro-inflammatory factors and pro-apoptotic mediators to protect liver and heart. Therefore, it can be suggested that EECGL contributed competent scientific information to validate the demands for its use to treat MSG-induced hepato-cardiac OS mediated inflammation and apoptosis from natural origin.

Endogenously increased n-3 PUFA levels in fat-1 transgenic mice do not protect from non-alcoholic steatohepatitis

Background

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide, ranging from simple steatosis to non-alcoholic steatohepatitis (NASH) and fibrosis. Possible reasons for the NAFLD epidemic in industrialized countries are the high intake of pro-inflammatory n-6 polyunsaturated fatty acids (n-6 PUFAs) and low consumption of healthy n-3 PUFAs. Due to their anti-inflammatory properties, n-3 PUFAs may have the potential to alleviate chronic liver disease. Herein, we examined the therapeutic effect of increased n-3 PUFA tissue levels in fat-1 transgenic mice on progressive NASH.

Methods

Disease was induced in mice by streptozotocin and high fat diet (STZ/HFD) resulting in NASH. NAFLD in 6 and 8 weeks old wild type and fat-1 transgenic STZ/HFD treated mice was analyzed. Unlike all other mammals, fat-1 transgenic mice ubiquitously express an n-3 fatty acid desaturase, which converts n-6 to n-3 PUFAs, leading to increased n-3 and decreased n-6 PUFA tissue contents.

Results

Liver damage, NAFLD activity score (NAS), hepatic lipid accumulation and inflammation were significantly reduced in fat-1 transgenic STZ/HFD treated mice in the early (6 weeks) but not late (8 weeks) phase of NASH. Simultaneously, mRNA expression of genes involved in fatty acid uptake and storage (Cd36 and Plin3, respectively) was significantly down-regulated in 6 week old but not 8 week old fat-1 transgenic STZ/HFD treated mice.

Conclusions

Endogenously elevated n-3 PUFA levels in fat-1 transgenic mice transiently delay the onset of STZ/HFD induced NASH but failed to efficiently protect from NASH development.

Fatty Acids Consumption: The Role Metabolic Aspects Involved in Obesity and Its Associated Disorders

Obesity and its associated disorders, such as insulin resistance, dyslipidemia, metabolic inflammation, dysbiosis, and non-alcoholic hepatic steatosis, are involved in several molecular and inflammatory mechanisms that alter the metabolism. Food habit changes, such as the quality of fatty acids in the diet, are proposed to treat and prevent these disorders. Some studies demonstrated that saturated fatty acids (SFA) are considered detrimental for treating these disorders. A high fat diet rich in palmitic acid, a SFA, is associated with lower insulin sensitivity and it may also increase atherosclerosis parameters. On the other hand, a high intake of eicosapentaenoic (EPA) and docosahexaenoic (DHA) fatty acids may promote positive effects, especially on triglyceride levels and increased high-density lipoprotein (HDL) levels. Moreover, polyunsaturated fatty acids (PUFAs) and monounsaturated fatty acids (MUFAs) are effective at limiting the hepatic steatosis process through a series of biochemical events, such as reducing the markers of non-alcoholic hepatic steatosis, increasing the gene expression of lipid metabolism, decreasing lipogenic activity, and releasing adiponectin. This current review shows that the consumption of unsaturated fatty acids, MUFA, and PUFA, and especially EPA and DHA, which can be applied as food supplements, may promote effects on glucose and lipid metabolism, as well as on metabolic inflammation, gut microbiota, and hepatic metabolism.

Phytosterol esters attenuate hepatic steatosis in rats with non-alcoholic fatty liver disease rats fed a high-fat diet

Given the adverse effects of drugs used for NAFLD treatment, identifying novel and effective natural compound to prevent NAFLD is urgently needed. In the present study, the effects of phytosterol esters (PSEs) on NAFLD were explored. Adult SD rats were randomized into five groups: normal chow diet (NC), high-fat diet (HF), low-, medium- and high-dose PSE treatment plus high-fat diet groups (PSEL, PSEM, and PSEH). Our results showed that the levels of LDL-C in the PSEL group and hepatic TG, TC, and FFA in the three PSEs groups were significantly decreased. Notably, the uric acid (UA) level was significantly decreased by PSEs intervention. The hepatic inflammatory stress was ameliorated via the inhibition of the cytokines, including TGF-β, IL-6, IL-10 and CRP in the PSEs intervention groups. Further, the oxidative status was improved by PSE treatment through adjusting the enzyme activity (SOD and XOD) and decreasing the MDA level. These beneficial effects of PSE may have been partly due to its regulation on the expression of TGF-β1, TGF-β2, TNF-α, UCP-2, PPAR-α and PPAR-γ in hepatic tissue at both mRNA and protein level. The results of this study suggest that PSEs may be used as therapeutic agents for the prevention and progression of NAFLD and that hyperuricemia is induced by high-fat diet consumption.

Amelioration of non-alcoholic fatty liver disease with NPC1L1-targeted IgY or n-3 polyunsaturated fatty acids in mice

Patients with non-alcoholic fatty liver disease (NAFLD) have an increased risk for progression to hepatocellular carcinoma in addition to comorbidities such as cardiovascular and serious metabolic diseases; however, the current therapeutic options are limited. Based on our previous report that omega-3 polyunsaturated fatty acids (n-3 PUFAs) can significantly ameliorate high fat diet (HFD)-induced NAFLD, we explored the therapeutic efficacy of n-3 PUFAs and N-IgY, which is a chicken egg yolk-derived IgY specific for the Niemann-Pick C1-Like 1 (NPC1L1) cholesterol transporter, on NAFLD in mice. We generated N-IgY and confirmed its efficient cholesterol transport-blocking activity in HepG2 and Caco-2 cells, which was comparable to the effect of ezetimibe (EZM). C57BL/6 wild type and fat-1 transgenic mice, capable of producing n-3 PUFAs, were fed a high fat diet (HFD) alone or supplemented with N-IgY. Endogenously synthesized n-3 PUFAs combined with N-IgY led to significant decreases in hepatic steatosis, fibrosis, and inflammation (p<0.01). The combination of N-IgY and n-3 PUFAs resulted in significant upregulation of genes involved in cholesterol uptake (LDLR), reverse cholesterol transport (ABCG5/ABCG8), and bile acid metabolism (CYP7A1). Moreover, fat-1 transgenic mice treated with N-IgY showed significant downregulation of genes involved in cholesterol-induced hepatic stellate cell activation (Tgfb1, Tlr4, Col1a1, Col1a2, and Timp2). Collectively, these data suggest that n-3 PUFAs and N-IgY, alone or in combination, represent a promising treatment strategy to prevent HFD-induced fatty liver through the activation cholesterol catabolism to bile acids and by decreasing cholesterol-induced fibrosis.

Role of dietary fatty acids in liver injury caused by vinyl chloride metabolites in mice

BACKGROUND

Vinyl chloride (VC) causes toxicant-associated steatohepatitis at high exposure levels. Recent work by this group suggests that underlying liver disease may predispose the liver to VC hepatotoxicity at lower exposure levels. The most common form of underlying liver disease in the developed world is non-alcoholic fatty liver disease (NAFLD). It is well-known that the type of dietary fat can play an important role in the pathogenesis of NAFLD. However, whether the combination of dietary fat and VC/metabolites promotes liver injury has not been studied.

METHODS

Mice were administered chloroethanol (CE - a VC metabolite) or vehicle once, 10weeks after being fed diets rich in saturated fatty acids (HSFA), rich in poly-unsaturated fatty acids (HPUFA), or the respective low-fat control diets (LSFA; LPUFA).

RESULTS

In control mice, chloroethanol caused no detectable liver injury, as determined by plasma transaminases and histologic indices of damage. In HSFA-fed mice, chloroethanol increased HSFA-induced liver damage, steatosis, infiltrating inflammatory cells, hepatic expression of proinflammatory cytokines, and markers of endoplasmic reticulum (ER) stress. Moreover, markers of inflammasome activation were increased, while markers of inflammasome inhibition were downregulated. In mice fed HPUFA all of these effects were significantly attenuated.

CONCLUSIONS

Chloroethanol promotes inflammatory liver injury caused by dietary fatty acids. This effect is far more exacerbated with saturated fat, versus poly-unsaturated fat; and strongly correlates with a robust activation of the NLRP3 inflammasome in the saturated fed animals only. Taken together these data support the hypothesis that environmental toxicant exposure can exacerbate the severity of NAFLD/NASH.

Effectiveness of Omega-3 Polyunsaturated Fatty Acids in Non-Alcoholic Fatty Liver Disease: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a clinical syndrome with the main characteristic of diffuse liver cells with fatty changes. The clinical evolution of NAFLD includes simple non-alcoholic fatty liver, non-alcoholic steatohepatitis (NASH), liver fibrosis and cirrhosis, and even hepatocellular carcinoma.

METHODS AND FINDINGS

We conducted this review to identify the effectiveness of omega-3 polyunsaturated fatty acids (ω-3 PUFA) in NAFLD. We searched PubMed, Cochrane Library and Embase. All randomized controlled trials (RCTs) of ω-3 PUFA treatment for NAFLD were considered. Two reviewers assessed the quality of each study and collected data independently. Disagreements were resolved by discussion among the reviewers and any of the other authors of the paper. We performed a meta-analysis and reported summary estimates of outcomes as inverse variance (IV), fixed or random, with 95% confidence intervals (CIs). We included seven RCTs involving 442 patients (227 for the experimental group and 215 for the control group). All the patients were divided into two groups: one treated with ω-3 PUFA and the other was the control group (generally placebo). The demographics of the ω-3 PUFA and control groups were comparable. Beneficial changes in alanine aminotransferase (ALT) (IV 95% CI: -7.61 [-12.83 to -2.39], p = 0.004), total cholesterol (TC) (IV 95% CI: -13.41 [-21.44 to -5.38], p = 0.001), triglyceride (TG) (IV 95% CI: -43.96 [-51.21 to -36.71], p<0.00001) and high-density lipoprotein cholesterol (HDL-C) (IV 95% CI: 6.97 [2.05 to 11.90], p = 0.006) favored ω-3 PUFA treatment. Omega-3 PUFA tended towards a beneficial effect on aspartate aminotransferase (AST) (IV 95% CI: -6.89 [-17.71 to 3.92], p = 0.21), γ-glutamyl transferase (GGT) (IV 95% CI: -8.28 [-18.38 to 1.83], p = 0.11) and low-density lipoprotein cholesterol (LDL-C) (IV 95% CI: -7.13 [-14.26 to 0.0], p = 0.05).

CONCLUSIONS

Supplementation with ω-3 PUFA is a practical and effective treatment for NAFLD to decrease ALT, TC and increase HDL-C, especially to decrease TG. Omega-3 PUFA also has a tendency toward a beneficial effect on AST, GGT and LDL-C. More high-quality, large RCTs are needed to validate our findings.

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

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

Molecular Pathogenesis of NASH

Nonalcoholic steatohepatitis (NASH) is the main cause of chronic liver disease in the Western world and a major health problem, owing to its close association with obesity, diabetes, and the metabolic syndrome. NASH progression results from numerous events originating within the liver, as well as from signals derived from the adipose tissue and the gastrointestinal tract. In a fraction of NASH patients, disease may progress, eventually leading to advanced fibrosis, cirrhosis and hepatocellular carcinoma. Understanding the mechanisms leading to NASH and its evolution to cirrhosis is critical to identifying effective approaches for the treatment of this condition. In this review, we focus on some of the most recent data reported on the pathogenesis of NASH and its fibrogenic progression, highlighting potential targets for treatment or identification of biomarkers of disease progression.

Role of bioactive fatty acids in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is characterized by fat deposition in hepatocytes, and a strong association with nutritional factors. Dietary fatty acids are classified according to their biochemical properties, which confer their bioactive roles. Monounsaturated fatty acids have a dual role in various human and murine models. In contrast, polyunsaturated fatty acids exhibit antiobesity, anti steatosic and anti-inflammatory effects. The combination of these forms of fatty acids—according to dietary type, daily intake and the proportion of n-6 to n-3 fats—can compromise hepatic lipid metabolism. A chemosensory rather than a nutritional role makes bioactive fatty acids possible biomarkers for NAFLD. Bioactive fatty acids provide health benefits through modification of fatty acid composition and modulating the activity of liver cells during liver fibrosis. More and better evidence is necessary to elucidate the role of bioactive fatty acids in nutritional and clinical treatment strategies for patients with NAFLD.

MERTK rs4374383 polymorphism affects the severity of fibrosis in non-alcoholic fatty liver disease

BACKGROUND & AIM

Homozygosity for a common non-coding rs4374383 G>A polymorphism in MERTK (myeloid-epithelial-reproductive tyrosine kinase) has been associated with the protection against fibrosis progression in chronic hepatitis C. The main study objective was to assess whether MERTK AA genotype influences liver fibrosis, and secondarily MERTK expression in patients with non-alcoholic fatty liver disease (NAFLD). We also investigated whether MERTK is expressed in human hepatic stellate cells (HSC) and in murine models of fibrogenesis.

METHODS

We considered 533 consecutive patients who underwent liver biopsy for suspected non-alcoholic steatohepatitis (NASH) without severe obesity from two Italian cohorts. As controls, we evaluated 158 patients with normal liver enzymes and without metabolic disturbances. MERTK rs4374383 genotype was assessed by 5'-nuclease assays. MERTK expression was analysed in mouse models of fibrosis, and the effect of the MERTK ligand GAS6 were investigated in human HSC.

RESULTS

Clinically significant fibrosis (stage F2-F4) was observed in 19% of patients with MERTK AA compared to 30% in those with MERTK GG/GA (OR 0.43, CI 0.21-0.88, p=0.02; adjusted for centre, and genetic, clinical-metabolic and histological variables). The protective rs4374383 AA genotype was associated with lower MERTK hepatic expression. MERTK was overexpressed in the liver of NAFLD patients with F2-F4 fibrosis and in in vivo models of fibrogenesis. Furthermore, exposure of cultured human HSC to the MERTK ligand GAS6, increased cell migration and induced procollagen expression. These effects were counteracted by inhibition of MERTK activity, which also resulted in apoptotic death of HSC.

CONCLUSIONS

The rs4374383 AA genotype, associated with lower intrahepatic expression of MERTK, is protective against F2-F4 fibrosis in patients with NAFLD. The mechanism may involve modulation of HSC activation.

Regulation of Inflammation by IL-17A and IL-17F Modulates Non-Alcoholic Fatty Liver Disease Pathogenesis

Non-alcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease worldwide. While it is well-accepted that inflammation is central to NAFLD pathogenesis, the immune pathway(s) orchestrating disease progression are poorly defined. Notably, IL-17RA signaling, via IL-17A, plays an important role in obesity-driven NAFLD pathogenesis. However, the role of the IL-17F, another IL-17RA ligand, in NAFLD pathogenesis has not been examined. Further, the cell types expressing IL-17RA and producing IL-17RA ligands in the pathogenesis of NAFLD have not been defined. Here, IL-17RA-/-, IL-17A-/-, IL-17F-/- and wild-type (WT) mice were fed either standard chow diet or methionine and choline deficient diet (MCDD)--a diet known to induce steatosis and hepatic inflammation through beta-oxidation dysfunction--and hepatic inflammation and NAFLD progression were subsequently quantified. MCDD feeding augmented hepatic IL-17RA expression and significantly increased hepatic infiltration of macrophages and IL-17A and IL-17F producing CD4+ and CD8+ T cells in WT mice. In contrast, IL-17RA-/-, IL-17A-/-, and IL-17F-/- mice, despite increased steatosis, exhibited significant protection from hepatocellular damage compared to WT controls. Protection from hepatocellular damage correlated with decreased levels of hepatic T-cell and macrophage infiltration and decreased expression of inflammatory mediators associated with NAFLD. In sum, our results indicate that the IL-17 axis also plays a role in a MCDD-induced model of NAFLD pathogenesis. Further, we show for the first time that IL-17F, and not only IL-17A, plays an important role in NAFLD driven inflammation.