Long-term melatonin administration improves glucose homeostasis and insulin resistance state in high-fat-diet fed rats

Emerging evidence support an important role of reactive oxygen species in various forms of insulin resistance. It is identified that melatonin has antioxidant properties and prevents toxic effects of reactive oxygen species. In this study, we sought to assess the involvement of melatonin in the progression of insulin resistance in response to a high-fat diet (HFD) and to investigate the underlying mechanisms. Male rats were fed with a control diet, a high-fat diet, or a high-fat diet supplemented with melatonin (5 mg kg^?1, i.p.) for 10 weeks. Glucose homeostasis, insulin sensitivity, antioxidative potency, and metabolic profiles in the rats were evaluated. Our results showed that a HFD led to increasing body mass, adipose tissue weight, plasma insulin, total cholesterol (TC), triglycerides (TG), free fatty acids (FFA), and decreased HDL-cholesterol (HDL-C) in rats. There was also a significant increase in the level of malondialdehyde (MDA) and decrease in superoxide dismutase (SOD) activity, oxidative stress markers both in the plasma and liver. An enhanced hepatic phosphoenolpyruvate carboxy-kinase (PEPCK) activity and RNA expression were observed. Impaired insulin signaling was evidenced by reducing insulin receptor substrate 2 (IRS2) tyrosine phosphorylation and protein kinase B (PKB) serine phosphorylation in response to insulin. Overactivation of stress-activated protein kinases JNK was also observed in the liver of HFD rats. However, simultaneous administration of melatonin to HFD rats significantly reduced oxidative stress in the system and liver, markedly improved impaired glucose homeostasis, insulin sensitivity, antioxidative potency, metabolic profiles and all the aforesaid adverse changes in HFD rats. Our results demonstrated that anti-oxidative property of melatonin is sufficient to ameliorate the insulin resistance condition, leading to the improvement of glucose homeostasis and the restoration of hepatic insulin signaling in a rat model of HFD-induced insulin resistance.     

Dietary cholesterol exacerbates hepatic steatosis and inflammation in obese LDL receptor-deficient mice

Non-alcoholic fatty liver disease (NAFLD), the hepatic manifestation of the metabolic syndrome, can progress to steatohepatitis (NASH) and advanced liver disease. Mechanisms that underlie this progression remain poorly understood, partly due to lack of good animal models that resemble human NASH. We previously showed that several metabolic syndrome features that develop in LDL receptor-deficient (LDLR-/-) mice fed a diabetogenic diet are worsened by dietary cholesterol. To test whether dietary cholesterol can alter the hepatic phenotype in the metabolic syndrome, we fed LDLR-/- mice a high-fat, high-carbohydrate diabetogenic diet (DD) without or with added cholesterol (DDC). Both groups of mice developed obesity and insulin resistance. Hyperinsulinemia, dyslipidemia, hepatic triglyceride, and alanine aminotransferase (ALT) elevations were greater with DDC. Livers of DD-fed mice showed histological changes resembling NAFLD, including steatosis and modest fibrotic changes; however, DDC-fed animals developed micro- and macrovesicular steatosis, inflammatory cell foci, and fibrosis resembling human NASH. Dietary cholesterol also exacerbated hepatic macrophage infiltration, apoptosis, and oxidative stress. Thus, LDLR-/- mice fed diabetogenic diets may be useful models for studying human NASH. Dietary cholesterol appears to confer a second "hit" that results in a distinct hepatic phenotype characterized by increased inflammation and oxidative stress.     

Searching for genetic factors of fatty liver in SMXA-5 mice by quantitative trait loci analysis under a high-fat diet

Fatty liver is strongly associated with the metabolic syndrome characterized by obesity, insulin resistance, and type 2 diabetes, but the genetic basis and functional mechanisms linking fatty liver with the metabolic syndrome are largely unknown. The SMXA-5 mouse is one of the SMXA recombinant inbred substrains established from SM/J and A/J strains and is a model for polygenic type 2 diabetes, characterized by moderately impaired glucose tolerance, hyperinsulinemia, and mild obesity. SMXA-5 mice also developed fatty liver, and a high-fat diet markedly worsened this trait, although SM/J and A/J mice are resistant to fatty liver development under a high-fat diet. To dissect loci for fatty liver in the A/J regions of the SMXA-5 genome, we attempted quantitative trait loci (QTLs) analysis in (SM/JxSMXA-5)F2 intercross mice fed a high-fat diet. We mapped a major QTL for relative liver weight and liver lipid content near D12Mit270 on chromosome 12 and designated this QTL Fl1sa. The A/J allele at this locus contributes to the increase in these traits. We confirmed the effect of Fl1sa on lipid accumulation in liver using the A/J-Chr12(SM) consomic strain, which showed significantly less accumulation than A/J mice. This suggests that the SM/J and A/J strains, neither of which develops fatty liver, possess loci causing fatty liver and that the coexistence of these loci causes fatty liver in SMXA-5 mice.     

Xanthohumol and 8-prenylnaringenin ameliorate diabetic-related metabolic dysfunctions in mice

Type 2 diabetes mellitus (T2DM) is a chronic disease characterized by metabolic disturbances in specific tissues. The present work aimed to analyze the effects of xanthohumol (XN) and 8-prenylnaringenin (8PN), two beer-derived polyphenols, in liver and skeletal muscle lipid and glycolytic metabolism in T2DM mice model. Thirty C57Bl/6 mice were randomly divided into five groups: standard diet (control), high-fat diet (DM), high-fat diet plus ethanol (DM-Ethanol), high-fat diet plus 10 mg/L XN (DM-XN) and high-fat diet plus 10 mg/L 8PN (DM-8PN) during 20 weeks. Fasting blood glucose and insulin tolerance tests were performed 1 week before sacrifice. At the end of the study, blood, liver and skeletal muscle were collected. Both XN and 8PN treatments prevented body weight gain; decreased glycemia, triglyceride, cholesterol and alkaline phosphatase levels; and improved insulin sensitivity. Polyphenols promoted hepatic and skeletal muscle AMP-activated protein kinase (AMPK) activation, diminishing the expression of target lipogenic enzymes (sterol regulatory element binding protein-1c and fatty acid synthase) and acetyl-CoA carboxylase activity. Moreover, both XN and 8PN treatments decreased VEGFR-1/VEGFB pathway, involved in fatty acid uptake, and increased AS160 expression, involved in GLUT4 membrane translocation. Presented data demonstrated that both XN and 8PN treatment resulted in AMPK signaling pathway activation, thus suppressing lipogenesis. Their consumption prevented body weight gain and improved plasma lipid profile, with significant improvement of insulin resistance and glucose tolerance. XN- or 8PN-enriched diet could ameliorate diabetic-associated metabolic disturbances by regulating glucose and lipid pathways.     

High ratio of ω-3/ω-6 polyunsaturated fatty acids targets mTORC1 to prevent high-fat diet-induced metabolic syndrome and mitochondrial dysfunction in mice

Adjusting ω-3/ω-6 polyunsaturated fatty acids (PUFAs) ratio in high-fat diet is one potential mean to improve metabolic syndrome; however, underlying mechanisms remain unclear. Four groups of mice were fed 60% kcal diets with saturated fatty acids, three different ω-3/ω-6 PUFAs ratios (low, middle and high) for 12 weeks, respectively. Body weight, atherosclerosis marker, insulin signal index and level of lipid accumulation in liver were significantly lowered in High group compared with saturated fatty acids group and Low group at week 12. Expressions of p-mTOR and raptor were inhibited by high ω-3 PUFAs. Importantly, ω-3 PUFAs intake up-regulated mitochondrial electron transport chain and tricarboxylic acid cycle pathway through metabolomics analysis in liver. Mitochondrial complexes activities were raised, fumaric acid was reduced and oxidative stress was alleviated in High group. We conclude that consuming long-term high-fat diet with same calories but high ω-3/ω-6 PUFAs ratio relieves metabolic syndrome by regulating mTORC1 pathway to enhance mitochondrial function.     

Toll-like receptor 3 ablation prevented high-fat diet-induced obesity and metabolic disorder

Inflammation in insulin-sensitive tissues (e.g., liver, visceral adipose tissue [VAT]) plays a major role in obesity and insulin resistance. Recruitment of innate immune cells drives the dysregulation of glucose and lipid metabolism. We aimed to seek the role of Toll like receptor 3 (TLR3), a pattern recognition receptor involved in innate immunity, obesity and the metabolic disorder. TLR3 expression in liver and VAT from diet induced obese mice and in VAT from overweight women was examined. Body weight, glucose homeostasis and insulin sensitivity were evaluated in TLR3 wild-type and knockout (KO) mice on a chow diet (CD) or high-fat diet for 15 weeks. At euthanasia, blood was collected, and plasma biochemical parameters and adipokines were determined with commercial kits. Flow cytometry was used to measure macrophage infiltration and activation in VAT. Standard western blot, immunohistochemistry and quantative PCR were used to assess molecules in pathways about lipid and glucose metabolism, insulin and inflammation in tissues of liver and VAT. Utilizing human and animal samples, we found that expression of TLR3 was upregulated in the liver and VAT in obese mice as well as VAT in overweight women. TLR3-deficiency protected against high-fat diet induced obesity, glucose intolerance, insulin resistance and lipid accumulation. Lipolysis was enhanced in VAT and hepatic lipogenesis was inhibited in TLR3 KO animals. Macrophages infiltration into adipose tissue was attenuated in TLR3 KO mice, accompanied with inhibition of NF-κB-dependent AMPK/Akt signaling pathway. These findings demonstrated that TLR3 ablation prevented obesity and metabolic disorders, thereby providing new mechanistic links between inflammation and obesity and associated metabolic abnormalities in lipid/glucose metabolism.     

Interleukin-38 alleviates hepatic steatosis through AMPK/autophagy-mediated suppression of endoplasmic reticulum stress in obesity models

Interleukin-38 (IL-38), recently recognized as a cytokine with anti-inflammatory properties that mitigate type 2 diabetes, has been associated with indicators of insulin resistance and nonalcoholic fatty liver disease (NAFLD). This study investigated the impact of IL-38 on hepatic lipid metabolism and endoplasmic reticulum (ER) stress. We assessed protein expression levels using Western blot analysis, while monodansylcadaverine staining was employed to detect autophagosomes in hepatocytes. Oil red O staining was utilized to examine lipid deposition. The study revealed elevated serum IL-38 levels in high-fat diet (HFD)-fed mice and IL-38 secretion from mouse keratinocytes. IL-38 treatment attenuated lipogenic lipid accumulation and ER stress markers in hepatocytes exposed to palmitate. Furthermore, IL-38 treatment increased AMP-activated protein kinase (AMPK) phosphorylation and autophagy. The effects of IL-38 on lipogenic lipid deposition and ER stress were nullified in cultured hepatocytes by suppressing AMPK through small interfering (si) RNA or 3-methyladenine (3MA). In animal studies, IL-38 administration mitigated hepatic steatosis by suppressing the expression of lipogenic proteins and ER stress markers while reversing AMPK phosphorylation and autophagy markers in the livers of HFD-fed mice. Additionally, AMPK siRNA, but not 3MA, mitigated IL-38-enhanced fatty acid oxidation in hepatocytes. In summary, IL-38 alleviates hepatic steatosis through AMPK/autophagy signaling-dependent attenuation of ER stress and enhancement of fatty acid oxidation via the AMPK pathway, suggesting a therapeutic strategy for treating NAFLD.     

Oxidative stress induced by high-glucose diet in liver of C57BL/6J mice and its underlying mechanism

High glycemic index diet can induce multiple diseases. Many research indicated that oxidative stress played important role in many pathological conditions. However, the impact of gene expression and dietary habit on oxidation process are still less clear. We used high-glucose diet to feed C57BL/6J mice for 4 weeks, measured the redox status, physiological and biochemical changes related to diabetes and consequence of metabolic syndrome (nonalcoholic fatty liver, cardiovascular disease), and detected the expressions of 14,446 genes in liver of C57BL/6J mice with DNA microarray. The results showed high-glucose diet induced elevated fatty acid accumulation in liver, insulin resistance index and higher weight in C57BL/6J mice, which indicated high-glucose diet caused to the initiation and development of diabetes and consequence of metabolic syndrome. The results also showed high-glucose diet induced oxidative stress in liver of C57BL/6J mice, which might the cause of initiation and development of diabetes and consequence of metabolic syndrome. Microarray analysis found expressions of genes related to thiol redox, fatty acid oxidation in peroxisome and cytochrome P450 were significantly changed, indicating system in which non-enzyme antioxidant capacity was impaired and sources from which reactive oxygen species (ROS) generated, which revealed the molecular mechanism of oxidative stress induced by high-glucose diet. We validated our microarray findings by conducting real-time RT–PCR assays on selected genes.     

Probiotic culture supernatant improves metabolic function through FGF21-adiponectin pathway in mice

High-fat/high-fructose diet plus intermittent hypoxia exposure (HFDIH) causes metabolic disorders such as insulin resistance, obesity, nonalcoholic fatty liver disease (NAFLD) and type 2 diabetes. The purpose of this study is to examine the effects and understand the mechanism of action of Lactobacillus rhamnosus GG culture supernatant (LGGs) on HFDIH-induced metabolic dysfunction. Mice were fed high-fat:high-fructose diet for 15 weeks. After 3 weeks of feeding, the mice were exposed to chronic intermittent hypoxia for the next 12 weeks (HFDIH), and LGGs was supplemented over the entire experiment. HFDIH exposure significantly led to metabolic disorders. LGGs treatment showed significant improvements in indices of metabolic disorders including fat mass, energy expenditure, glucose intolerance, insulin resistance, increased hepatic steatosis and liver injury. HFDIH mice markedly increased adipose inflammation and adipocyte size, and reduced circulating adiponectin, which was restored by LGGs treatment. LGGs treatment increased hepatic FGF21 mRNA expression and circulating FGF21 protein levels, which were associated with increased hepatic PPARα expression and fecal butyrate concentration. In addition, HFDIH-induced hepatic fat accumulation and apoptosis were significantly reduced by LGGs supplementation. In summary, LGGs treatment increased energy expenditure and insulin sensitivity and prevented metabolic abnormalities in HFDIH mice, and this is associated with the FGF21-adiponectin signaling pathway. LGGs may be a potential prevention/treatment strategy in subjects with the metabolic syndrome.     

Inhibition of ADRP prevents diet-induced insulin resistance

Diets with high fat content induce steatosis, insulin resistance, and type 2 diabetes. The lipid droplet protein adipose differentiation-related protein (ADRP) mediates hepatic steatosis, but whether this affects insulin action in the liver or peripheral organs in diet-induced obesity is uncertain. We fed C57BL/6J mice a high-fat diet and simultaneously treated them with an antisense oligonucleotide (ASO) against ADRP for 4 wk. Glucose homeostasis was assessed with clamp and tracer techniques. ADRP ASO decreased the levels of triglycerides and diacylglycerol in the liver, but fatty acids, long-chain fatty acyl CoAs, ceramides, and cholesterol were unchanged. Insulin action in the liver was enhanced after ADRP ASO treatment, whereas muscle and adipose tissue were not affected. ADRP ASO increased the phosphorylation of insulin receptor substrate (IRS)1, IRS2, and Akt, and decreased gluconeogenic enzymes and PKCepsilon, consistent with its insulin-sensitizing action. These results demonstrate an important role for ADRP in the pathogenesis of diet-induced insulin resistance.     

Elevated TCA cycle function in the pathology of diet-induced hepatic insulin resistance and fatty liver

The manner in which insulin resistance impinges on hepatic mitochondrial function is complex. Although liver insulin resistance is associated with respiratory dysfunction, the effect on fat oxidation remains controversial, and biosynthetic pathways that traverse mitochondria are actually increased. The tricarboxylic acid (TCA) cycle is the site of terminal fat oxidation, chief source of electrons for respiration, and a metabolic progenitor of gluconeogenesis. Therefore, we tested whether insulin resistance promotes hepatic TCA cycle flux in mice progressing to insulin resistance and fatty liver on a high-fat diet (HFD) for 32 weeks using standard biomolecular and in vivo (2)H/(13)C tracer methods. Relative mitochondrial content increased, but respiratory efficiency declined by 32 weeks of HFD. Fasting ketogenesis became unresponsive to feeding or insulin clamp, indicating blunted but constitutively active mitochondrial β-oxidation. Impaired insulin signaling was marked by elevated in vivo gluconeogenesis and anaplerotic and oxidative TCA cycle flux. The induction of TCA cycle function corresponded to the development of mitochondrial respiratory dysfunction, hepatic oxidative stress, and inflammation. Thus, the hepatic TCA cycle appears to enable mitochondrial dysfunction during insulin resistance by increasing electron deposition into an inefficient respiratory chain prone to reactive oxygen species production and by providing mitochondria-derived substrate for elevated gluconeogenesis.     

Chromium attenuates high-fat diet-induced nonalcoholic fatty liver disease in KK/HlJ mice

Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disease associated with insulin resistance, oxidative stress, and inflammation. Evidence indicates that chromium has a role in the regulation of glucose and lipid metabolism and may improve insulin sensitivity. In this study, we report that chromium supplementation has a beneficial effect against NAFLD. We found that KK/HlJ mice developed obesity and progressed to NAFLD after feeding with high-fat diet for 8 weeks. High-fat-fed KK/HlJ mice showed hepatocyte injury and hepatic triglyceride accumulation, which was accompanied by insulin resistance, oxidative stress, and inflammation. Chromium supplementation prevented progression of NAFLD and the beneficial effects were accompanied by reduction of hepatic triglyceride accumulation, elevation of hepatic lipid catabolic enzyme, improvement of glucose and lipid metabolism, suppression of inflammation as well as resolution of oxidative stress, probably through enhancement of insulin signaling. Our findings suggest that chromium could serve as a hepatoprotective agent against NAFLD.     

Metabolic consequences of ENPP1 overexpression in adipose tissue

Ectonucleotide pyrophosphate phosphodiesterase (ENPP1) has been shown to negatively modulate insulin receptor and to induce cellular insulin resistance when overexpressed in various cell types. Systemic insulin resistance has also been observed when ENPP1 is overexpressed in multiple tissues of transgenic models and attributed largely to tissue insulin resistance induced in skeletal muscle and liver. Another key tissue in regulating glucose and lipid metabolism is adipose tissue (AT). Interestingly, obese patients with insulin resistance have been reported to have increased AT ENPP1 expression. However, the specific effects of ENPP1 in AT have not been studied. To better understand the specific role of AT ENPP1 on systemic metabolism, we have created a transgenic mouse model (C57/Bl6 background) with targeted overexpression of human ENPP1 in adipocytes, using aP2 promoter in the transgene construct (AdiposeENPP1-TG). Using either regular chow or pair-feeding protocol with 60% fat diet, we compared body fat content and distribution and insulin signaling in adipose, muscle, and liver tissues of AdiposeENPP1-TG and wild-type (WT) siblings. We also compared response to intraperitoneal glucose tolerance test (IPGTT) and insulin tolerance test (ITT). Our results show no changes in Adipose ENPP1-TG mice fed a regular chow diet. After high-fat diet with pair-feeding protocol, AdiposeENPP1-TG and WT mice had similar weights. However, AdiposeENPP1-TG mice developed fatty liver in association with changes in AT characterized by smaller adipocyte size and decreased phosphorylation of insulin receptor Tyr(1361) and Akt Ser(473). These changes in AT function and fat distribution were associated with systemic abnormalities of lipid and glucose metabolism, including increased plasma concentrations of fatty acid, triglyceride, plasma glucose, and insulin during IPGTT and decreased glucose suppression during ITT. Thus, our results show that, in the presence of a high-fat diet, ENPP1 overexpression in adipocytes induces fatty liver, hyperlipidemia, and dysglycemia, thus recapitulating key manifestations of the metabolic syndrome.     

Protection against the Metabolic Syndrome by Guar Gum-Derived Short-Chain Fatty Acids Depends on Peroxisome Proliferator-Activated Receptor γ and Glucagon-Like Peptide-1

The dietary fiber guar gum has beneficial effects on obesity, hyperglycemia and hypercholesterolemia in both humans and rodents. The major products of colonic fermentation of dietary fiber, the short-chain fatty acids (SCFAs), have been suggested to play an important role. Recently, we showed that SCFAs protect against the metabolic syndrome via a signaling cascade that involves peroxisome proliferator-activated receptor (PPAR) γ repression and AMP-activated protein kinase (AMPK) activation. In this study we investigated the molecular mechanism via which the dietary fiber guar gum protects against the metabolic syndrome. C57Bl/6J mice were fed a high-fat diet supplemented with 0% or 10% of the fiber guar gum for 12 weeks and effects on lipid and glucose metabolism were studied. We demonstrate that, like SCFAs, also guar gum protects against high-fat diet-induced metabolic abnormalities by PPARγ repression, subsequently increasing mitochondrial uncoupling protein 2 expression and AMP/ATP ratio, leading to the activation of AMPK and culminating in enhanced oxidative metabolism in both liver and adipose tissue. Moreover, guar gum markedly increased peripheral glucose clearance, possibly mediated by the SCFA-induced colonic hormone glucagon-like peptide-1. Overall, this study provides novel molecular insights into the beneficial effects of guar gum on the metabolic syndrome and strengthens the potential role of guar gum as a dietary-fiber intervention.     

利拉鲁肽联合维生素D对高脂诱导非酒精性脂肪肝小鼠的影响及机制

目的: 探讨利拉鲁肽联合维生素D对高脂诱导非酒精性脂肪肝(NAFLD)小鼠的影响及其潜在机制。方法: C57BL/6小鼠随机平均分为对照组、NAFLD模型组、利拉鲁肽组、维生素D组和利拉鲁肽联合维生素D组,每组10只。对照组普通饲料连续喂养12 周; 模型组高脂饲料连续喂养12周; 利拉鲁肽组、维生素D组和联合组均高脂饲料连续喂养12周, 从第9周起上述3组小鼠分别腹腔注射0.6 mg/(kg·d)利拉鲁肽、灌胃250 mg/(kg·d)维生素D和腹腔注射0.6 mg/(kg·d)利拉鲁肽及灌胃250 mg/(kg·d)维生素D。喂养至12周后,收集各组小鼠血液和肝组织进行生化及病理检测;并采用免疫印迹方法检测各组小鼠肝组织AMP活化蛋白激酶(AMPK)磷酸化水平。结果: 与模型组相比,利拉鲁肽或维生素D单独或联合治疗均可改善NAFLD小鼠肝脏脂质积累(甘油三酯: 6.0±0.7 vs 3.8±0.3, 3.9±0.3和2.1±0.2,P均＜0.05;胆固醇:1.4±0.5 vs 0.9±0.2, 0.8±0.2和0.5±0.1,P均＜0.05)和脂肪变性(NAFLD活动评分:2.4±0.3 vs 1.0±0.2, 0.9±0.1和0.6±0.1,P均＜0.05);此外与利拉鲁肽或维生素D组相比,利拉鲁肽联合维生素D治疗效果更明显,而且可能与调节胰岛素抵抗和AMPK磷酸化相关。结论: 结果表明,维生素D可增强利拉鲁肽对高脂诱导NAFLD的治疗效果,其机制可能与调节胰岛素抵抗和AMPK磷酸化有关。     

Liver-specific FGFR4 knockdown in mice on an HFD increases bile acid synthesis and improves hepatic steatosis

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease with increased risk in patients with metabolic syndrome. There are no FDA-approved treatments, but FXR agonists have shown promising results in clinical studies for NAFLD management. In addition to FXR, fibroblast growth factor receptor FGFR4 is a key mediator of hepatic bile acid synthesis. Using N-acetylgalactosamine–conjugated siRNA, we knocked down FGFR4 specifically in the liver of mice on chow or high-fat diet and in mouse primary hepatocytes to determine the role of FGFR4 in metabolic processes and hepatic steatosis. Liver-specific FGFR4 silencing increased bile acid production and lowered serum cholesterol. Additionally, we found that high-fat diet–induced liver steatosis and insulin resistance improved following FGFR4 knockdown. These improvements were associated with activation of the FXR-FGF15 axis in intestinal cells, but not in hepatocytes. We conclude that targeting FGFR4 in the liver to activate the intestinal FXR-FGF15 axis may be a promising strategy for the treatment of NAFLD and metabolic dysfunction.     

Blocking Nuclear Factor-Kappa B Protects against Diet-Induced Hepatic Steatosis and Insulin Resistance in Mice

Inflammation critically contributes to the development of various metabolic diseases. However, the effects of inhibiting inflammatory signaling on hepatic steatosis and insulin resistance, as well as the underlying mechanisms remain obscure. In the current study, male C57BL/6J mice were fed a chow diet or high-fat diet (HFD) for 8 weeks. HFD-fed mice were respectively treated with p65 siRNA, non-silence control siRNA or vehicle every 4^th day for the last 4 weeks. Vehicle-treated (HF) and non-silence siRNA-treated (HFNS) mice displayed overt inflammation, hepatic steatosis and insulin resistance compared with chow-diet-fed (NC) mice. Upon treatment with NF-κB p65 siRNA, HFD-fed (HFPS) mice were protected from hepatic steatosis and insulin resistance. Furthermore, Atg7 and Beclin1 expressions and p-AMPK were increased while p-mTOR was decreased in livers of HFPS mice in relative to HF and HFNS mice. These results suggest a crosslink between NF-κB signaling pathway and liver AMPK/mTOR/autophagy axis in the context of hepatic steatosis and insulin resistance.