High-fat High-cholesterol Diet Research Articles

Validation of a diet-induced Macaca fascicularis model of non-alcoholic steatohepatitis with dietary and pioglitazone interventions.

To develop an obese, insulin-resistant cynomolgus monkey model of non-alcoholic steatohepatitis (NASH) with fibrosis with a high fat/high cholesterol (HFHC) diet (with or without high fructose) and test its responsiveness to caloric restriction or pioglitazone. First, two groups of monkeys (n=24/group) with histologically proven NASH and fibrosis were fed the HFHC diet for 17 weeks. The treatment group was subjected to a 40% caloric restriction (CR) and had their diet switched from the HFHC diet to a chow diet (DSCR). Paired liver biopsies were taken before and 17 weeks after DSCR. Subsets of monkeys (nine/group) had whole liver fat content assessed by MRI. Next, two groups of monkeys with histologically proven NASH and fibrosis were treated with vehicle (n=9) or pioglitazone (n=20) over 24 weeks. The HFHC and DSCR groups lost 0.9% and 11.4% of body weight, respectively. After 17 weeks, non-alcoholic fatty liver disease activity score (NAS) improvement was observed in 66.7% of the DSCR group versus 12.5% of the HFHC group (P< .001). Hepatic fat was reduced to 5.2% in the DSCR group versus 23.0% in the HFHC group (P= .0001). After 24 weeks, NAS improvement was seen in 30% of the pioglitazone group versus 0% of the vehicle group (P= .08). Both weight loss induced by DSCR and treatment with pioglitazone improve the histological features of NASH in a diet-induced cynomolgus monkey model. This model provides a translational preclinical model for testing novel NASH therapies.

FGF21 protects against hepatic lipotoxicity and macrophage activation to attenuate fibrogenesis in nonalcoholic steatohepatitis.

Analogues of the hepatokine fibroblast growth factor 21 (FGF21) are in clinical development for type 2 diabetes and nonalcoholic steatohepatitis (NASH) treatment. Although their glucose-lowering and insulin-sensitizing effects have been largely unraveled, the mechanisms by which they alleviate liver injury have only been scarcely addressed. Here, we aimed to unveil the mechanisms underlying the protective effects of FGF21 on NASH using APOE*3-Leiden.CETP mice, a well-established model for human-like metabolic diseases. Liver-specific FGF21 overexpression was achieved in mice, followed by administration of a high-fat high-cholesterol diet for 23 weeks. FGF21 prevented hepatic lipotoxicity, accompanied by activation of thermogenic tissues and attenuation of adipose tissue inflammation, improvement of hyperglycemia and hypertriglyceridemia, and upregulation of hepatic programs involved in fatty acid oxidation and cholesterol removal. Furthermore, FGF21 inhibited hepatic inflammation, as evidenced by reduced Kupffer cell (KC) activation, diminished monocyte infiltration, and lowered accumulation of monocyte-derived macrophages. Moreover, FGF21 decreased lipid- and scar-associated macrophages, which correlated with less hepatic fibrosis as demonstrated by reduced collagen accumulation. Collectively, hepatic FGF21 overexpression limits hepatic lipotoxicity, inflammation, and fibrogenesis. Mechanistically, FGF21 blocks hepatic lipid influx and accumulation through combined endocrine and autocrine signaling, respectively, which prevents KC activation and lowers the presence of lipid- and scar-associated macrophages to inhibit fibrogenesis.

Apolipoprotein E-depletion accelerates arterial fat deposition in the spontaneously hypertensive rat.

Hypertension and atherosclerosis are often found in one patient causing serious cardiovascular events. An animal model simultaneously expressing hypertension and atherosclerosis would be useful to study such a complex risk status. We therefore attempted to introduce a null mutation of the apolipoprotein E (ApoE) gene into the spontaneously hypertensive rat (SHR) using CRISPR/Cas9 to establish a genetic model for atherosclerosis with hypertension. We successfully established SHRApoE(-/-) having a 13-bps deletion in the 5'-end of ApoE gene. Deletion of ApoE protein was confirmed by Western blotting. Blood pressure of SHRApoE(-/-) was comparable to that of SHR. Feeding the rats with high fat high cholesterol diet (HFD) caused a significant increase in LDL cholesterol as well as in triglyceride in SHRApoE(-/-). After 8 weeks of HFD loading, superficial fat deposition was observed both in the aorta and the mesenteric arteries of SHRApoE(-/-) instead of mature atheromatous lesions found in humans. In addition, a null mutation of peroxiredoxin 2 (Prdx2) was introduced into SHRApoE(-/-) to examine the effect of increased oxidative stress on the development of atherosclerosis. SHR with the double depletion of ApoE and Prdx2 did not show mature atheroma either. Further, salt loading did not promote development of atheroma although it accelerated the development of fat deposition. These results indicated that when compared with ApoE-knockout mice, SHRApoE(-/-) was more resistant to atherosclerosis even though they have severe hypertension.

Probiotic interventions promote metabolic health in high fat-fed hamsters in association with gut microbiota and endocannabinoidome alterations.

Probiotics represent a promising tool to improve metabolic health, including lipid profiles and cholesterol levels. Modulation of the gut microbiome and the endocannabinoidome - two interrelated systems involved in several metabolic processes influenced by probiotics - has been proposed as a potential mechanism of action. This study establishes the impact of probiotics on metabolic health, gut microbiota composition and endocannabinoidome mediators in an animal model of hypercholesterolaemia. Syrian hamsters were fed either a low-fat low-cholesterol or high-fat high-cholesterol (HFHC) diet to induce hypercholesterolaemia and gavaged for 6 weeks with either Lactobacillus acidophilus CL1285, Lactiplantibacillus plantarum CHOL-200 or a combination of the two. Globally, probiotic interventions ameliorated, at least partially, lipid metabolism in HFHC-fed hamsters. The interventions, especially those including L. acidophilus, modified the gut microbiota composition of the small intestine and caecum in ways suggesting reversal of HFHC-induced dysbiosis. Several associations were observed between changes in gut microbiota composition and endocannabinoidome mediators following probiotic interventions and both systems were also associated with improved metabolic health parameters. For instance, potential connexions between the Eubacteriaceae and Deferribacteraceae families, levels of 2‑palmitoylglycerol, 2‑oleoylglycerol, 2‑linoleoylglycerol or 2‑eicosapentaenoylglycerol and improved lipid profiles were found. Altogether, our results suggest a potential crosstalk between gut microbiota and the endocannabinoidome in driving metabolic benefits associated with probiotics, especially those including L. acidophilus, in an animal model of hypercholesterolaemia.

Pien Tze Huang Protects Against Non-Alcoholic Steatohepatitis by Modulating the Gut Microbiota and Metabolites in Mice

Non-alcoholic steatohepatitis (NASH) is a severe form of non-alcoholic fatty liver disease without effective treatment. The traditional Chinese medicine formulation Pien Tze Huang (PTH) can suppress inflammatory diseases. Here, we evaluate the effects of PTH on the evolution of NASH and its underlying mechanisms. We found that PTH prevented the development of steatohepatitis induced by various dietary models, including a high-fat high-cholesterol (HFHC) diet, choline-deficient high-fat diet (CD-HFD), and methionine- and choline-deficient (MCD) diet, along with significant suppression of liver injury, hepatic triglyceride, and lipid peroxidation. Moreover, ten days of PTH treatment after the onset of NASH significantly ameliorated MCD diet-induced steatosis and liver injury in mice. Through the metagenomic sequencing of stool samples, we found that PTH administration restored the gut microbiota with enrichment of probiotics including Lactobacillus acidophilus (L. acidophilus), Lactobacillus plantarum, Lactococcus lactis, and Bacillus subtilis. The enriched L. acidophilus prevented MCD diet-induced steatohepatitis. In addition, PTH restored the gut barrier function in mice with steatohepatitis, as evidenced by reduced intestinal permeability, decreased serum lipopolysaccharides (LPS) level, and increased epithelial tight-junction protein E-cadherin expression. Our metabolomic analysis via liquid chromatography-mass spectrometry profiling identified the alteration in the metabolism of bile acids in the portal vein of PTH-treated mice. We further confirmed that an intact gut microbiota is necessary for PTH to exhibit anti-steatohepatitis effects. In conclusion, PTH protects against steatohepatitis development by modulating the gut microbiota and metabolites. PTH is a potential promising prophylactic and therapeutic option for patients with NASH.

A Systems Analysis of Phenotype Heterogeneity in APOE*3Leiden.CETP Mice Induced by Long-Term High-Fat High-Cholesterol Diet Feeding.

Within the human population, considerable variability exists between individuals in their susceptibility to develop obesity and dyslipidemia. In humans, this is thought to be caused by both genetic and environmental variation. APOE*3-Leiden.CETP mice, as part of an inbred mouse model in which mice develop the metabolic syndrome upon being fed a high-fat high-cholesterol diet, show large inter-individual variation in the parameters of the metabolic syndrome, despite a lack of genetic and environmental variation. In the present study, we set out to resolve what mechanisms could underlie this variation. We used measurements of glucose and lipid metabolism from a six-month longitudinal study on the development of the metabolic syndrome. Mice were classified as mice with either high plasma triglyceride (responders) or low plasma triglyceride (non-responders) at the baseline. Subsequently, we fitted the data to a dynamic computational model of whole-body glucose and lipid metabolism (MINGLeD) by making use of a hybrid modelling method called Adaptations in Parameter Trajectories (ADAPT). ADAPT integrates longitudinal data, and predicts how the parameters of the model must change through time in order to comply with the data and model constraints. To explain the phenotypic variation in plasma triglycerides, the ADAPT analysis suggested a decreased cholesterol absorption, higher energy expenditure and increased fecal fatty acid excretion in non-responders. While decreased cholesterol absorption and higher energy expenditure could not be confirmed, the experimental validation demonstrated that the non-responders were indeed characterized by increased fecal fatty acid excretion. Furthermore, the amount of fatty acids excreted strongly correlated with bile acid excretion, in particular deoxycholate. Since bile acids play an important role in the solubilization of lipids in the intestine, these results suggest that variation in bile acid homeostasis may in part drive the phenotypic variation in the APOE*3-Leiden.CETP mice.

Abstract 9575: TOTUM-070 Hypocholesterolemic Effect Linked to Intestinal Cholesterol Absorption Inhibition. An in vivo and in vitro Study

TOTUM-070 (T070) is a patented blend of five plant extracts designed to act in combination to prevent hypercholesterolemia. Previous study in dyslipidemic hamster model fed a High Fat High Cholesterol (HFHC) diet for 12 weeks demonstrated that supplementation with T070 at 3,5% to 5% in the diet (n=16 per group) reduced serum non-HDL cholesterol compared to HFHC group (-38%, p&lt;0,001 and -47%, p&lt;0,001, respectively) as well as serum triglyceride levels (-30%, n.s and -46%, p&lt;0,05, respectively). We aimed to decipher the mechanisms of action of T070 both in vivo and in vitro. First, the chemical characterization of T070 by HPLC-UV/MS analyses led to the identification and quantification of 37 biomolecules such as oleuropein, oleanolic acid or chlorogenic acid. Total RNA sequencing analysis of livers from the HFHC and T070 5% supplemented groups highlighted 511 genes with significant different expression level between groups. Among canonical pathways identified, 19 genes implicated in metabolism were differentially regulated with T070. Several functional tests were performed in hamster fed with T070 5% for 12 weeks in comparison to HFHC group (n=14 per group). Dosage of lipoprotein lipase activity ex vivo did not show any difference between groups. Results from hepatic triglyceride production test detected no effect of T070. However, an oral fat tolerance test showed that post-prandial hypertriglyceridemia was significantly reduced by 40% (p&lt;0,01) in T070 group following olive oil gavage compared to the HFHC hamsters. Finally, in vivo intestinal [4- 14 C]-Cholesterol absorption test demonstrated a 12% reduction (n.s) with T070 5% compared to HFHC group. In vitro investigations were assessed on differentiated human enterocyte Caco2 cells. Incubation with T070 at 1g/l for 1h acutely reduced [1,2- 3 H(N)]-cholesterol uptake by 30% in Caco2 cells (p&lt;0.01). Pharmacological inhibition of cholesterol transporter NPC1L1 abolished the effect of T070 on cholesterol uptake. There was no effect of T070 on NPC1L1 protein expression in Caco2 cells, suggesting T070 blocked directly NPC1L1 activity. Altogether, our results demonstrate that hypocholesterolemic effect of T070 is mediated by inhibition of intestinal cholesterol absorption.

FGF15 promotes hepatic NPC1L1 degradation in lithogenic diet-fed mice

BackgroundCholesterol gallstone disease (CGD) is accompanied by biliary cholesterol supersaturation. Hepatic Niemann-Pick C1-like 1 (NPC1L1), which is present in humans but not in wild-type (WT) mice, promotes hepatocyte cholesterol uptake and decreases biliary cholesterol supersaturation. In contrast, intestinal NPC1L1 promotes intestinal cholesterol absorption, increasing biliary cholesterol supersaturation. Ezetimibe (EZE) can inhibit both hepatic and intestinal NPC1L1. However, whether hepatic NPC1L1 can affect CGD progress remains unknown.MethodsMice expressing hepatic NPC1L1 (NPC1L1hepatic-OE mice) were generated using Adeno-associated viruses (AAV) gene delivery. The protein level and function of hepatic NPC1L1 were examined under chow diet, high fat-cholesterol diet (HFCD), and lithogenic diet (LD) feeding. Gallstone formation rates were examined with or without EZE treatment. Fibroblast growth factor 15 (FGF15) treatment and inhibition of fibroblast growth factor receptor 4 (FGFR4) were applied to verify the mechanism of hepatic NPC1L1 degradation.ResultsThe HFCD-fed NPC1L1hepatic-OE mice retained the biliary cholesterol desaturation function of hepatic NPC1L1, whereas EZE treatment decreased biliary cholesterol saturation and did not cause CGD. The ubiquitination and degradation of hepatic NPC1L1 were discovered in LD-fed NPC1L1hepatic-OE mice. Treatment of FGF15 during HFCD feeding and inhibition of FGFR4 during LD feeding could affect the protein level and function of hepatic NPC1L1.ConclusionsLD induces the ubiquitination and degradation of hepatic NPC1L1 via the FGF15-FGFR4 pathway. EZE may act as an effective preventative agent for CGD.

Myeloid But Not Endothelial Expression of the CB2 Receptor Promotes Atherogenesis in the Context of Elevated Levels of the Endocannabinoid 2-Arachidonoylglycerol

The endocannabinoid 2-arachidonoylglycerol (2-AG) is an inflammatory mediator and ligand for the cannabinoid receptors CB1 and CB2. We investigated the atherogenic mechanisms set in motion by 2-AG. Therefore, we created two atherosclerotic mouse models with distinct cell-specific knockouts of the CB2 receptor on either myeloid or endothelial cells. These mice were treated with JZL184, resulting in elevated plasma levels of 2-AG. After a high-fat high-cholesterol diet, atherosclerotic plaques were analyzed. The atherogenic effect of 2-AG was abrogated in mice lacking myeloid expression of the CB2 receptor but not in mice lacking endothelial expression of the CB2 receptor. In vitro, treatment of human monocytes with 2-AG led to the increased production of reactive oxygen species (ROS) and IL-1β. In conclusion, 2-AG shows an atherogenic effect in vivo, dependent on the presence of the CB2 receptor on myeloid cells. In addition, our in vitro data revealed 2-AG to promote inflammatory signalling in monocytes.Graphical abstract2-Arachidonoylglycerol shows an atherogenic effect that is abrogated in mice lacking myeloid expression of the CB2 receptor.

Mild dyslipidemia accelerates tumorigenesis through expansion of Ly6Chi monocytes and differentiation to pro-angiogenic myeloid cells

Cancer and cardiovascular disease (CVD) share common risk factors such as dyslipidemia, obesity and inflammation. However, the role of pro-atherogenic environment and its associated low-grade inflammation in tumor progression remains underexplored. Here we show that feeding C57BL/6J mice with a non-obesogenic high fat high cholesterol diet (HFHCD) for two weeks to induce mild dyslipidemia, increases the pool of circulating Ly6Chi monocytes available for initial melanoma development, in an IL-1β-dependent manner. Descendants of circulating myeloid cells, which accumulate in the tumor microenvironment of mice under HFHCD, heighten pro-angiogenic and immunosuppressive activities locally. Limiting myeloid cell accumulation or targeting VEGF-A production by myeloid cells decrease HFHCD-induced tumor growth acceleration. Reverting the HFHCD to a chow diet at the time of tumor implantation protects against tumor growth. Together, these data shed light on cross-disease communication between cardiovascular pathologies and cancer.

Supplementation of Bouea macrophylla Fruit Juice Prevent Oxidative Stress in Rats Fed with High-Fat High-Cholesterol Diet through Attenuation of Lipid Peroxidation

Fruits are rich in fiber and antioxidant compounds that can prevent and treat health disorders related to oxidative stress caused by high-fat high-cholesterol diet (HFHCD). Bouea macrophylla is a tropical fruit plant with edible juicy fruits. In this study, we conducted experiments to prove the effectiveness of B. macrophylla fruit juice (BMFJ) as an antioxidant agent in rats fed with HFHCD. Male Sprague Dawley rats were fed with HFHCD for 100 days and simultaneously orally supplemented with BMFJ. Atorvastatin was used as a positive control. At the end of the experiment, the blood and hepar were collected and assayed for malondialdehyde (MDA). The in vitro antioxidant activity of BMFJ was also evaluated using the DPPH method. Total phenols and flavonoids contents were determined using Folin Ciocalteu and AlCl3 methods, respectively. Results of the experiments showed that total phenols and flavonoids in BMFJ were 570 mg GAE/g and 31.89 mg QE/g, respectively, and the IC50 of radical scavenging activity was 564.271 ppm. The in vivo antioxidant evaluation showed that supplementation of BMFJ significantly prevents the increase of MDA levels, both in serum and liver of rats fed with HFHCD. These findings clearly indicate that supplementation of B. macrophylla fruit juice significantly prevents oxidative stress in rats fed with high-fat high-cholesterol diets through attenuation of lipid peroxidation.

Dietary 7-ketocholesterol exacerbates myocardial ischemia–reperfusion injury in mice through monocyte/macrophage-mediated inflammation

Emerging evidence suggests that 7-ketocholesterol (7-KC), one of the most abundant dietary oxysterols, causes inflammation and cardiovascular diseases. Here we show the deteriorating effects of dietary 7-KC on myocardial ischemia–reperfusion (IR) injury and detailed the molecular mechanisms. A high-fat high-cholesterol diet containing 7-KC (7KWD) for 3 weeks increased the plasma 7-KC level compared with high-fat high-cholesterol diet in mice. In wild-type mice but not in CCR2−/− mice, dietary 7-KC increased the myocardial infarct size after IR. Flow cytometry revealed that the ratio of Ly-6Chigh inflammatory monocytes to total monocytes was increased in the 7KWD group. Unbiased RNA sequencing using murine primary macrophages revealed that 7-KC regulated the expression of transcripts related to inflammation and cholesterol biosynthesis. We further validated that in vitro, 7-KC induced endoplasmic reticulum stress, mitochondrial reactive oxygen species production, and nuclear factor-kappa B activation, which are associated with increased mRNA levels of proinflammatory cytokines. Administration of N-acetyl-l-cysteine or siRNA-mediated knockdown of PKR-like endoplasmic reticulum kinase or endoplasmic reticulum oxidase 1α suppressed the levels of 7-KC-induced inflammation. Dietary 7-KC exacerbates myocardial IR injury through monocyte/macrophage-mediated inflammation. Endoplasmic reticulum stress and oxidative stress are involved in the 7-KC-induced proinflammatory response in macrophages.

Copper fabric improves the metabolic profile of obese mice: Potential role of the gut microbiota.

Copper and copper alloys have antimicrobial activity through the rapid contact killing of viruses, bacteria and yeasts on their surface. Dysregulation of host microbiota can contribute to the pathogenesis of inflammatory diseases such as obesity, diabetes and cardiovascular disease. Anecdotal evidence noted improved overall well-being in individuals sleeping on copper-containing fabric bedding. We hypothesized that the beneficial effect of copper-infused fabric bedding on cardiometabolic health is linked to changes in gut microbiota composition. This study utilized a mouse model of diet-induced obesity to assess the beneficial effects of copper-infused fabric bedding on metabolic health. Body composition, inflammatory markers, metabolic and cardiovascular status and changes in the faecal microbiota composition were evaluated for up to 2 months in mice fed with a normal chow diet or high fat high cholesterol diet in the presence of bedding made with and without copper-infused fabric. Results showed that mice subjected to diet-induced obesity and housed in cages with copper-infused fabric liner displayed less body weight gain than mice in cages with control fabric. Mice housed with copper-infused fabric also displayed improved glucose tolerance and reduced inflammation biomarker lipocalin-2. We also observed a beneficial shift in gut bacterial composition of obese mice housed with copper fabric bedding. Taken in conjunction, our study provides direct animal-based evidence supporting the beneficial effects of copper fabric on metabolic health.

Hepatic transcript signatures predict atherosclerotic lesion burden prior to a 2-year high cholesterol, high fat diet challenge.

The purpose of this study was to identify molecular mechanisms by which the liver influences total lesion burden in a nonhuman primate model (NHP) of cardiovascular disease with acute and chronic feeding of a high cholesterol, high fat (HCHF) diet. Baboons (47 females, 64 males) were fed a HCHF diet for 2 years (y); liver biopsies were collected at baseline, 7 weeks (w) and 2y, and lesions were quantified in aortic arch, descending aorta, and common iliac at 2y. Unbiased weighted gene co-expression network analysis (WGCNA) revealed several modules of hepatic genes correlated with lesions at different time points of dietary challenge. Pathway and network analyses were performed to study the roles of hepatic module genes. More significant pathways were observed in males than females. In males, we found modules enriched for genes in oxidative phosphorylation at baseline, opioid signaling at 7w, and EIF2 signaling and HNF1A and HNF4A networks at baseline and 2y. One module enriched for fatty acid β oxidation pathway genes was found in males and females at 2y. To our knowledge, this is the first study of a large NHP cohort to identify hepatic genes that correlate with lesion burden. Correlations of baseline and 7w module genes with lesions at 2y were observed in males but not in females. Pathway analyses of baseline and 7w module genes indicate EIF2 signaling, oxidative phosphorylation, and μ-opioid signaling are possible mechanisms that predict lesion formation induced by HCHF diet consumption in males. Our findings of coordinated hepatic transcriptional response in male baboons but not female baboons indicate underlying molecular mechanisms differ between female and male primate atherosclerosis.

High-fat diet activates splenic NOD1 and enhances neutrophil recruitment and neutrophil extracellular traps release in the spleen of ApoE-deficient mice

In the course of atherogenesis, the spleen plays an important role in the regulation of extramedullary hematopoiesis, and in the control of circulating immune cells, which contributes to plaque progression. Here, we have investigated the role of splenic nucleotide-binding oligomerization domain 1 (NOD1) in the recruitment of circulating immune cells, as well as the involvement of this immune organ in extramedullary hematopoiesis in mice fed on a high-fat high-cholesterol diet (HFD). Under HFD conditions, the absence of NOD1 enhances the mobilization of immune cells, mainly neutrophils, from the bone marrow to the blood. To determine the effect of NOD1-dependent mobilization of immune cells under pro-atherogenic conditions, Apoe−/− and Apoe−/−Nod1−/− mice fed on HFD for 4 weeks were used. Splenic NOD1 from Apoe−/− mice was activated after feeding HFD as inferred by the phosphorylation of the NOD1 downstream targets RIPK2 and TAK1. Moreover, this activation was accompanied by the release of neutrophil extracellular traps (NETs), as determined by the increase in the expression of peptidyl arginine deiminase 4, and the identification of citrullinated histone H3 in this organ. This formation of NETs was significantly reduced in Apoe−/−Nod1−/− mice. Indeed, the presence of Ly6G+ cells and the lipidic content in the spleen of mice deficient in Apoe and Nod1 was reduced when compared to the Apoe−/− counterparts, which suggests that the mobilization and activation of circulating immune cells are altered in the absence of NOD1. Furthermore, confirming previous studies, Apoe−/−Nod1−/− mice showed a reduced atherogenic disease, and diminished recruitment of neutrophils in the spleen, compared to Apoe−/− mice. However, splenic artery ligation reduced the atherogenic burden in Apoe−/− mice an effect that, unexpectedly was lost in Apoe−/−Nod1−/− mice. Together, these results suggest that neutrophil accumulation and activity in the spleen are driven in part by NOD1 activation in mice fed on HFD, contributing in this way to regulating atherogenic progression.

P53 deficiency affects cholesterol esterification to exacerbate hepatocarcinogenesis.

Cholesterol ester (CE) biosynthesis and homeostasis play critical roles in many cancers, including HCC, but their exact mechanistic contributions to HCC disease development require further study. Here, we report on a proposed role of tumor suppressor P53 in its repressing ubiquitin-specific peptidase 19 (USP19) and sterol O-acyltransferase (SOAT) 1, which maintains CE homeostasis. USP19 enhances cholesterol esterification and contributes to hepatocarcinogenesis (HCG) by deubiquitinating and stabilizing SOAT1. Loss of either SOAT1 or USP19 dramatically attenuates cholesterol esterification and HCG in P53-deficient mice fed with either a normal chow diet or a high-cholesterol, high-fat diet (HCHFD). SOAT1 inhibitor avasimibe has more inhibitory effect on HCC progression in HCHFD-maintained P53-deficient mice when compared to the inhibitors of de novo cholesterol synthesis. Consistent with our findings in the mouse model, the P53-USP19-SOAT1 signaling axis is also dysregulated in human HCCs. Collectively, our findings demonstrate that SOAT1 participates in HCG by increasing cholesterol esterification, thus indicating that SOAT1 is a potential biomarker and therapeutic target in P53-deficient HCC.

476-P: Role of TGR5 Signalling in Hepatic Lipid and Lipoprotein Metabolism in Normal and Insulin-Resistant States

Fasting dyslipidemia is characterized by a lipid profile with elevated triglycerides, increased small dense LDL and low HDL-cholesterol, and is a commonly comorbid with insulin resistance. Bile acid (BA) signalling has been suggested to improve hepatic insulin sensitivity and lipid accumulation through activation of the Takeda G protein-coupled receptor 5 (TGR5) . As the role of TGR5 in regulating hepatic lipid and lipoprotein metabolism has not been explored, the present study was performed to characterize the role of bile acid signaling via TGR5 in hepatic lipid and lipoprotein metabolism. We have recently developed novel Tgr5-/- and GLP1R-/- hamster models. Tgr5+/+ and Tgr5-/ - hamsters were fed a high fat, high fructose, and low cholesterol (FFLC) diet for 6 weeks. Glucose tolerance, insulin tolerance, and fasting plasma lipids were examined at baseline, and following 6-weeks on diet. Loss of TGR5 signalling appeared to be initially protective against diet induced hypertriglyceridemia, however this effect was lost with prolonged feeding. Following 6 weeks of diet, Tgr5-/ - hamsters were less glucose tolerant, with similar insulin sensitivity. Fasting plasma deoxycholic acid (DCA) and taurocholic acid (TCA) compositions differed under chow fed conditions, with additional changes in postprandial DCA, TCA and cholic acid (CA) . Finally, chow fed Tgr5+/+ and Tgr5-/ - hamsters received intraduodenal injections (IDI) of DCA or TCA. Both DCA and TCA administration were associated with reduced VLDL-triglyceride secretion in Tgr5+/+ hamsters, an effect that was blunted in Tgr5-/ -hamsters. The lipid lowering effects of DCA were similarly blunted in GLP1R-/- hamsters, suggesting this effect is dependent on GLP-1R signalling. The present research will set a framework to expand our knowledge of the role of BA signaling through TGR5 in hepatic lipogenesis. Disclosure D.C.L.Alvares: None. S.S.Hoffman: None. K.Adeli: None.

THC and CBD affect metabolic syndrome parameters including microbiome in mice fed high fat-cholesterol diet

BackgroundNonalcoholic fatty liver disease (NAFLD) is associated with metabolic syndrome, which often includes obesity, diabetes, and dyslipidemia. Several studies in mice and humans have implicated the involvement of the gut microbiome in NAFLD. While cannabis and its phytocannabinoids may potentially be beneficial for treating metabolic disorders such as NAFLD, their effects on liver diseases and gut microbiota profile have yet to be addressed. In this study, we evaluated the therapeutic effects of the two major cannabinoids, delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), on NAFLD progression.MethodsNAFLD was induced by feeding mice a high fat-cholesterol diet (HFCD) for 6 weeks. During this period, the individual cannabinoids, THC or CBD, were added to the experimental diets at a concentration of 2.5 or 2.39 mg/kg. Profile of lipids, liver enzymes, glucose tolerance, and gene expression related to carbohydrate lipids metabolism and liver inflammation was analyzed. The effect of THC or CBD on microbiota composition in the gut was evaluated.ResultsWhile not alleviating hepatic steatosis, THC or CBD treatment influenced a number of parameters in the HFCD mouse model. CBD increased food intake, improved glucose tolerance, reduced some of the inflammatory response including TNFa and iNOS, and partially mitigated the microbiome dysbiosis observed in the HFCD fed mice. THC produced a much weaker response, only slightly reducing inflammatory-related gene expression and microbiome dysbiosis.ConclusionsThe results of this study indicate the potential therapeutic effects of individual phytocannabinoids are different from the effects of the cannabis plant possessing a mixture of compounds. While CBD may help ameliorate symptoms of NAFLD, THC alone may not be as effective. This disparity can putatively be explained based on changes in the gut microbiota.

Poloxamer 407 Induces Hypertriglyceridemia but Decreases Atherosclerosis in Ldlr-/- Mice.

Background: Hypertriglyceridemia (HTG) increases the risk for atherosclerotic cardiovascular disease, but underlying mechanisms are incompletely understood. Circulating monocytes play an important role in atherogenesis by infiltrating arterial walls, where they differentiate into macrophages. We tested the hypothesis that HTG is mechanistically linked to atherogenesis by altering the monocyte phenotype and infiltration into atherosclerotic lesions in a model of diet-induced atherogenesis in Ldlr−/− mice. Methods: HTG was induced in male Ldlr−/− mice, fed a Western, high-fat high-cholesterol diet, by daily injection of poloxamer 407 (P407), a lipoprotein lipase inhibitor, for seven weeks. Atherosclerosis, monocyte phenotypes, and monocyte migration into atherosclerotic lesions were determined by well-validated methods. Results: Compared with the saline control, P407 injection in Ldlr−/− mice rapidly induced profound and persistent HTG, modestly elevated plasma cholesterol levels, and increased levels of triglyceride and cholesterol carried in very-low-density lipoprotein and low-density lipoprotein. Unexpectedly, mice receiving P407 versus saline control showed less atherosclerosis. Following induction of HTG by P407, CD36+ (also CD11c+), but not CD36− (CD11c−), monocytes showed early increases in lipid accumulation, but the number of CD36+ (not CD36−) monocytes was dramatically decreased afterwards in the circulation until the end of the test. Concurrently, CD36+ (CD11c+) monocyte migration into atherosclerotic lesions was also reduced in mice receiving P407 versus controls. Conclusions: P407 induced severe HTG, but reduced atherosclerosis, in Ldlr−/− mice, possibly because of profound reductions of circulating CD36+ (CD11c+) monocytes, leading to decreased monocyte migration into atherosclerotic lesions.

Pueraria lobata starch regulates gut microbiota and alleviates high-fat high-cholesterol diet induced non-alcoholic fatty liver disease in mice

The dried roots of Pueraria lobata (Willd.) Ohwi as an edible medicinal herb are enriched with starch. However, the structure, physiology, and biological bioactivity of P. lobata starch (PLS) has not yet been fully investigated. This study showed that PLS consisted of mixed population of granules with polyhedral or spherical surface. The apparent content of resistant starch was 23.14%, and the molecular weight was 1.93 × 107 Da. PLS showed a branching degree and an average polymerization rate of 2.06% and 20.74%, respectively, with fairly high proportion of B1 short chains. The solubility and swelling power of PLS were 38.51% and 28.10 g/g, respectively, showing high hot stability of the viscosity. In vitro fermentation of PLS resulted in specifically altered composition of gut microbiota and increased production of SCFAs, showing a potential prebiotic effect. Moreover, PLS remarkably alleviated inflammation, hepatic steatosis and dyslipidemia in mice with high-fat high-cholesterol diet induced non-alcoholic fatty liver disease (NAFLD). The protective effect of PLS was associated with amelioration of NAFLD-associated gut dysbiosis through specifically increasing the abundance of Lactobacillus, Bifidobacterium and Turicibacter, and decreasing Desulfovibrio. The results would support the use of PLS as a functional prebiotic for protecting against NAFLD.