High-fat High-cholesterol Diet Research Articles

Neoagarotetraose Alleviates Atherosclerosis via Modulating Cholesterol and Bile Acid Metabolism in ApoE-/- Mice.

Atherosclerosis is closely associated with metabolic disorders such as cholesterol accumulation, bile acid metabolism, and gut dysbiosis. Neoagarotetraose supplementation has been shown to inhibit obesity and alleviate type 2 diabetes, but its effects on modulating the development of atherosclerosis remain unexplored. Therefore, the present study was conducted to investigate the protective effects and potential mechanisms of neoagarotetraose on high-fat, high-cholesterol diet (HFHCD)-induced atherosclerosis in ApoE-/- mice. The results showed that neoagarotetraose supplementation decreased the atherosclerotic lesion area by 50.1% and the aortic arch lesion size by 80.4% compared to the HFHCD group. Furthermore, neoagarotetraose supplementation led to a significant reduction in hepatic lipid content, particularly non-high-density lipoprotein cholesterol. It also resulted in a substantial increase in total bile acid content in both urine and fecal samples by 3.0-fold and 38.7%, respectively. Moreover, neoagarotetraose supplementation effectively downregulated the intestinal farnesoid X receptor by 35.8% and modulated the expressions of its associated genes in both the liver and intestine. In addition, correlation analysis revealed strong associations between gut microbiota composition and fecal bile acid levels. These findings highlight the role of gut microbiota in neoagarotetraose-mitigating atherosclerosis in HFHCD-fed ApoE-/- mice. This study indicates the potential of neoagarotetraose as a functional dietary supplement for the prevention of atherosclerosis.

Doenjang Ameliorates Diet-Induced Hyperlipidemia and Hepatic Oxidative Damage by Improving Lipid Metabolism, Oxidative Stress, and Inflammation in ICR Mice.

Hyperlipidemia, characterized by elevated cholesterol, lipids, and triglycerides in the bloodstream, is linked to hepatic oxidative damage. Doenjang, a traditional Korean condiment made from fermented soybeans, is known for its health benefits, yet its anti-hyperlipidemic effects remain understudied. Our study aimed to assess the hypolipidemic and hepatic protective effects of Doenjang on male ICR mice fed a high-fat cholesterol diet for 8 weeks. Mice were divided into three groups: the normal diet (ND), the high-fat cholesterol diet (HD), and the Doenjang-supplemented HD diet (DS) group. Doenjang supplementation significantly regulated total cholesterol, triglycerides, LDL cholesterol, and HDL cholesterol levels compared to the HD group. It also downregulated lipogenic genes, including PPARγ, FAS, and ACC, and positively influenced the cholesterol metabolism-related genes HMGCR and LXR. Moreover, Doenjang intake increased serum glutathione levels, activated oxidative stress defense genes (NRF2, SOD, GPx1, and CAT), positively modulated inflammation genes (NF-kB and IL6) in hepatic tissue, and reduced malondialdehyde levels. Our findings highlight the effectiveness of traditional Doenjang in preventing diet-induced hyperlipidemia and protecting against hepatic oxidative damage.

Enavogliflozin, an sglt2 inhibitor, improves nonalcoholic steatohepatitis induced by high-fat high-cholesterol diet

Enavogliflozin, an sglt2 inhibitor, improves nonalcoholic steatohepatitis induced by high-fat high-cholesterol diet

Therapeutic Targeting of PKM2 Ameliorates NASH Fibrosis Progression in A Macrophage-Specific and Liver-Specific Manner

Nonalcoholic steatohepatitis (NASH) may soon become the leading cause of end-stage liver disease worldwide with limited treatment options. Liver fibrosis, which is driven by chronic inflammation and hepatic stellate cell (HSC) activation, critically determines morbidity and mortality in patients with NASH. Pyruvate kinase M2 (PKM2) is involved in immune activation and inflammatory liver diseases; however, its role and therapeutic potential in NASH-related fibrosis remain largely unexplored. Bioinformatics screening and analysis of human and murine NASH livers indicated that PKM2 was upregulated in nonparenchymal cells (NPCs), especially macrophages, in the livers of patients with fibrotic NASH. Macrophage-specific PKM2 knockout (PKM2FL/FLLysM-Cre) significantly ameliorated hepatic inflammation and fibrosis severity in three distinct NASH models induced by a methionine- and choline-deficient (MCD) diet, a high-fat high-cholesterol (HFHC) diet, and a western diet plus weekly carbon tetrachloride injection (WD/CCl4). Single-cell transcriptomic analysis indicated that deletion of PKM2 in macrophages reduced profibrotic Ly6Chigh macrophage infiltration. Mechanistically, PKM2-dependent glycolysis promoted NLR family pyrin domain containing 3 (NLRP3) activation in proinflammatory macrophages, which induced HSC activation and fibrogenesis. A pharmacological PKM2 agonist efficiently attenuated the profibrotic crosstalk between macrophages and HSCs in vitro and in vivo. Translationally, ablation of PKM2 in NPCs by cholesterol-conjugated heteroduplex oligonucleotides, representing a novel oligonucleotide drug that preferentially accumulates in the liver, dose-dependently reversed NASH-related fibrosis without causing observable hepatotoxicity. The present study highlights the pivotal role of macrophage PKM2 in advancing NASH fibrogenesis. Thus, therapeutic modulation of PKM2 in a macrophage-specific or liver-specific manner may serve as a novel strategy to combat NASH-related fibrosis.

Neutrophil activation at high-fat high-cholesterol and high-fructose diets induces low-grade inflammation in mice

Nonalcoholic fatty liver disease (NAFLD), which can progress to nonalcoholic steatohepatitis (NASH), is a significant health concern affecting a substantial portion of the population. This study investigates the role of neutrophil extracellular traps (NETs) in liver inflammation induced by high-fat high-cholesterol diet (HFHCD) and high-fructose diet (HFD). The chronic nature of NAFLD involves low-grade inflammation with cytokine elevation. The research aims to visualize neutrophil elastase (NE) activity during HFHCD and HFD representing conditions of low-grade activation and assess neutrophil functional status. The study employs a mouse model subjecting animals to HFHCD, HFD or a standard diet (SD) for six weeks. Various analyses were used including histological evaluations, in vivo imaging of NE activity using a fluorescent probe, fluorescent microscopy, flow cytometry and assessment of neutrophil function through reactive oxygen species (ROS) levels. Mice on HFHCD and HFD display liver damage consistent with NASH, which was validated pathohistologically. NE activity in blood significantly increases after six weeks indicating systemic NETs involvement. In vivo imaging confirms NE activity in multiple organs. Cellular localization reveals NETs persistence even after neutrophil destruction in splenocytes indicating systemic involvement. Neutrophils under HFHCD exhibit a functional phenotype associated with low-grade inflammation, higher basal ROS levels and reduced activation potential. This study establishes the systemic impact of NETs in HFHCD- and HFD-induced liver inflammation, providing insights into the functional state of neutrophils. The findings contribute to understanding the mechanisms underlying chronic liver conditions and may inform future therapeutic strategies. Keywords: high fat diet, in vivo imaging, low-grade inflammation, NASH, neutrophil elastase, neutrophil extracellular traps, neutrophils

A high-dose of ursodeoxycholic acid treatment alleviates liver inflammation by remodeling gut microbiota and bile acid profile in a mouse model of non-alcoholic steatohepatitis

Ursodeoxycholic acid (UDCA) is a hydrophilic bile acid commonly used for treating cholestatic liver disease. However, its efficacy on non-alcoholic steatohepatitis (NASH) was controversial. This study aimed to investigate the impact of a high dosage of UDCA on a mouse model of NASH. Forty 6-week-old mice were fed a high-fat high-cholesterol (HFHC) diet for 12 weeks to establish a mouse model of NASH, and then divided into four groups: two groups transitioned to a normal diet, and the other two groups maintained the HFHC diet. Each group was administered a daily dosage of 300 mg/kg of UDCA or saline for a period of 8 weeks. The 16 s ribosomal RNA genes extracted from mice fecal pellets were sequenced using next-generation sequencing techniques. Serum bile acid profiles were quantified using liquid chromatography electrospray ionization tandem mass spectrometry method. The results showed that UDCA treatment ameliorated liver inflammation, without affecting liver fibrosis. UDCA treatment reduced the relative abundance of the genera Bacteroides, Parabacteroides, and Intestinimonas, whereas increased the relative abundance of the genera norank_f_Muribaculaceae and Parasutterella in the HFHC-maintaining groups. The serum levels of total bile acids and total primary bile acids increased, whereas those of endogenous primary bile acids decreased after UDCA treatment. Correlation analysis showed that primary bile acids were negatively correlated with the genera norank_f_Christensenellaceae and unclassified_f_Ruminococcaceae. In conclusion, a high dosage of UDCA can alleviate liver inflammation, probably by modifying the composition of gut microbiota and serum bile acid profiles in NASH mice.

Theabrownin as a Potential Prebiotic Compound Regulates Lipid Metabolism via the Gut Microbiota, Microbiota-Derived Metabolites, and Hepatic FoxO/PPAR Signaling Pathways.

The dysregulation of lipid metabolism poses a significant health threat, necessitating immediate dietary intervention. Our previous research unveiled the prebiotic-like properties of theabrownin. This study aimed to further investigate the theabrownin-gut microbiota interactions and their downstream effects on lipid metabolism using integrated physiological, genomic, metabolomic, and transcriptomic approaches. The results demonstrated that theabrownin significantly ameliorated dyslipidemia, hepatic steatosis, and systemic inflammation induced by a high-fat/high-cholesterol diet (HFD). Moreover, theabrownin significantly improved HFD-induced gut microbiota dysbiosis and induced significant alterations in microbiota-derived metabolites. Additionally, the detailed interplay between theabrownin and gut microbiota was revealed. Analysis of hepatic transcriptome indicated that FoxO and PPAR signaling pathways played pivotal roles in response to theabrownin-gut microbiota interactions, primarily through upregulating hepatic Foxo1, Prkaa1, Pck1, Cdkn1a, Bcl6, Klf2, Ppara, and Pparg, while downregulating Ccnb1, Ccnb2, Fabp3, and Plin1. These findings underscored the critical role of gut-liver axis in theabrownin-mediated improvements in lipid metabolism disorders and supported the potential of theabrownin as an effective prebiotic compound for targeted regulation of metabolic diseases.

Voluntary exercise fails to prevent metabolic dysfunction-associated steatotic liver disease progression in male rats fed a high-fat high-cholesterol diet.

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a major public health issue with a worldwide prevalence of 30%-32%. In animal models, voluntary exercise may be an alternative to forced physical activity, avoiding stress, potential injuries, and being logistically simpler. Here, we assessed voluntary exercise (Vex) in Sprague-Dawley rats fed a high-fat, high-cholesterol diet for 18 weeks to induce MASLD. We quantified workload (speed and distance) using exercise wheels and evaluated energy expenditure using calorimetric cages. MASLD progression was assessed using circulating and hepatic biochemical and gene markers of steatosis, inflammation, and fibrosis. The animals ran an average of 301 km during the study period, with the average daily distance peaking at 4937 m/day during Weeks 3-4 before decreasing to 757 m/day by the end of the study. Rats exposed to Vex showed no improvement in any of the MASLD-associated features, such as steatosis, inflammation, or fibrosis. Rats exposed to Vex exhibited a higher total energy expenditure during the night phase (+0.35 kcal/h; p = 0.003) without resulting in any effect on body composition. We conclude that, in our experimental conditions, Vex failed to prevent MASLD progression in male Sprague-Dawley rats exposed to a high-fat high-cholesterol diet for 18 weeks.

Prevention of Hypercholesterolemia with "Liposomes in Microspheres" Composite Carriers: A Promising Approach for Intestinal-Targeted Oral Delivery of Astaxanthin.

Cardiovascular diseases are caused by hypercholesterolemia. Astaxanthin (AST) has been reported to exhibit antioxidant and anti-inflammatory properties. However, its bioavailability is poor because of low solubility and instability. In order to improve the bioavailability of AST, we developed an intestinal-responsive composite carrier termed as "liposomes in micropheres" incorporating N-succinyl-chitosan (NSC)-poly(ethylene glycol) (PEG) liposomes that functionalized by neonatal Fc receptors (FcRn) into hydrogels of sodium alginate (SA) and carboxymethyl chitosan (CMCS). In the AST NSC/HSA-PEG liposomes@SA/CMCS microspheres, the AST's encapsulation efficiency (EE) was 96.26% (w/w) and its loading capacity (LC) was 6.47% (w/w). AST NSC/HSA-PEG liposomes had stability in the gastric conditions and achieved long-term release of AST in intestinal conditions. Then, AST NSC/HSA-PEG liposomes@SA/CMCS bind to intestinal epithelial cell targets by the neonatal Fc receptor. In vitro permeation studies show that there was a 4-fold increase of AST NSC/HSA-PEG liposomes@SA/CMCS in AST permeation across the intestinal epithelium. Subsequent in vivo experiments demonstrated that the composite carrier exhibited a remarkable mucoadhesive capacity, allowing for extended intestinal retention of up to 12 h, and it displayed deep penetration through the mucus layer, efficiently entering the intestinal villi epithelial cells, and enhancing the absorption of AST and its bioavailability in vivo. And oral administration of AST NSC/HSA-PEG liposomes@SA/CMCS could effectively prevent hypercholesterolemia caused by a high-fat, high-cholesterol diet (HFHCD). These advancements highlight the potential of NSC/HSA-PEG liposomes@SA/CMCS composite carriers for targeted and oral uptake of hydrophobic bioactives.

Intestinal epithelial Krüppel-like factor 4 alleviates endotoxemia and atherosclerosis through improving NF-κB/miR-34a-mediated intestinal permeability.

Maintenance of intestinal barrier function contributes to gastrointestinal homeostasis and therefore cardiovascular diseases. A number of studies show that intestinal permeability is affected by excessive inflammatory responses. Krüppel-like factor (KLF) 4 is one of the critical transcriptional factors, which controls multiple immune responses. In this study we investigated the role of KLF4 in regulating intestinal inflammation and permeability during the atherosclerotic process. Atherosclerotic model was established in ApoE-/- mice by feeding a high fat high cholesterol (HFHC) diet. We showed that colon expression levels of KLF4 and tight junction proteins were significantly decreased whereas inflammatory responses increased in atherosclerotic mice. Overexpression of colon epithelial Klf4 decreased atherosclerotic plaque formation and vascular inflammation in atherosclerotic mice, accompanied by remarkable suppression of intestinal NF-κB activation. We found that overexpression of epithelial Klf4 in atherosclerotic mice significantly increased intestinal tight junction expression and ameliorated endotoxemia, whereas replenishment of LPS abolished these benefits. Overexpression of Klf4 reversed LPS-induced permeability and downregulation of ZO-1 and Occludin in Caco-2 cells in vitro. HFHC diet stimulated the expression of epithelial microRNA-34a, whereas silence of epithelial Klf4 abolished the benefits of microRNA-34a sponge, a specific miR-34a inhibitor, on intestinal permeability and atherosclerotic development. A clinical cohort of 24 atherosclerotic patients supported colon KLF4/NF-κB/tight junction protein axis mediated intestine/cardiovascular interaction in patients with atherosclerosis. Taken together, intestinal epithelial KLF4 protects against intestinal inflammation and barrier dysfunction, ameliorating atherosclerotic plaque formation.

Effect of glycyrrhizin and canagliflozin on treatment of non alcoholic fatty liver disease in a rat model.

Objective: To observe the effect of canagliflozin and glycyrrhizin in prevention of non-alcoholic fatty liver disease. Study Design: Randomized Control Trial. Setting: Animal House, Post Graduate Medical Institute, Lahore. Period: March 2018 to August 2019. Material & Methods: It was an experimental study in which twenty-four adult healthy male Sprague- Dawley rats were categorized in four groups. All groups except normal control (A) were fed high fat high cholesterol diet throughout the study period. After 8 weeks group Disease Control (B) was administered distilled water, Glycyrrhizin treatment group (C) was given glycyrrhizin 60 mg/kg, Canagliflozin treatment group (D) was given canagliflozin 10 mg/kg. At the end of study, animals were sacrificed and liver tissue was prepared for histopathological analysis. Data was analyzed by SPSS 25 using Kruskal Wallis ANOVA followed by Mann Whitney U test. P value < 0.05 was considered significant. Results: Both showed significant lower grade of hepatic steatosis when compared to disease control. Canagliflozin treated group had significant decrease in hepatic steatosis, hepatic inflammation and ballooning than glycyrrhizin treated group. Conclusion: Glycyrrhizin halted the progression of fatty liver disease. The prevention of disease by canagliflozin infers their beneficial effect for treatment of non-alcoholic fatty liver disease.

Trim21 deficiency in mice increases HCC carcinogenesis in a NASH context and is associated with immune checkpoint upregulation.

The global pandemic of metabolic diseases has increased the incidence of hepatocellular carcinoma (HCC) in the context of non-alcoholic steatohepatitis (NASH). The downregulation of the E3 ubiquitin ligase TRIM21 has been linked to poor prognosis in different cancers including HCC. In order to investigate the role of TRIM21 in liver cancer progression on NASH, Trim21+/+ and Trim21-/- male mice were injected with streptozotocin at the neonatal stage. The hypoinsulinemic mice were then fed with a high-fat high-cholesterol diet (HFHCD) for 4, 8 or 12 weeks. All mice developed NASH which systematically resulted in HCC progression. Interestingly, compared to the Trim21+/+ control mice, liver damage was worsened in Trim21-/- mice, with more HCC nodules found after 12 weeks on HFHCD. Immune population analysis in the spleen and liver revealed a higher proportion of CD4+PD-1+ and CD8+PD-1+ T cells in Trim21-/- mice. The liver and HCC tumors of Trim21-/- mice also exhibited an increase in the number of PD-L1+ and CD68+ PD-L1+ cells. Thus, TRIM21 limits the emergence of HCC nodules in mice with NASH by potentially restricting the expression of PD-1 in lymphocytes and PD-L1 in tumors.

Hepatic regulator of G protein signaling 14 ameliorates NAFLD through activating cAMP-AMPK signaling by targeting Giα1/3

ObjectiveNonalcoholic fatty liver disease (NAFLD) is an emerging public health threat as the most common chronic liver disease worldwide. However, there remains no effective medication to improve NAFLD. G protein-coupled receptors (GPCRs) are the most frequently investigated drug targets family. The Regulator of G protein signaling 14 (RGS14), as an essential negative modulator of GPCR signaling, plays important regulatory roles in liver damage and inflammatory responses. However, the role of RGS14 in NAFLD remains largely unclear. Methods and resultsIn this study, we found that RGS14 was decreased in hepatocytes in NAFLD individuals in a public database. We employed genetic engineering technique to explore the function of RGS14 in NAFLD. We demonstrated that RGS14 overexpression ameliorated lipid accumulation, inflammatory response and liver fibrosis in hepatocytes in vivo and in vitro. Whereas, hepatocyte specific Rgs14-knockout (Rgs14-HKO) exacerbated high fat high cholesterol diet (HFHC) induced NASH. Further molecular experiments demonstrated that RGS14 depended on GDI activity to attenuate HFHC-feeding NASH. More importantly, RGS14 interacted with Guanine nucleotide-binding protein (Gi) alpha 1 and 3 (Giα1/3, gene named GNAI1/3), promoting the generation of cAMP and then activating the subsequent AMPK pathways. GNAI1/3 knockdown abolished the protective role of RGS14, indicating that RGS14 binding to Giα1/3 was required for prevention against hepatic steatosis. ConclusionsRGS14 plays a protective role in the progression of NAFLD. RGS14-Giα1/3 interaction accelerated the production of cAMP and then activated cAMP-AMPK signaling. Targeting RGS14 or modulating the RGS14-Giα1/3 interaction may be a potential strategy for the treatment of NAFLD in the future.

Lactobacillus acidophilus suppresses non-alcoholic fatty liver disease-associated hepatocellular carcinoma through producing valeric acid

Gut probiotic depletion is associated with non-alcoholic fatty liver disease-associated hepatocellular carcinoma (NAFLD-HCC). Here, we investigated the prophylactic potential of Lactobacillus acidophilus against NAFLD-HCC. NAFLD-HCC conventional and germ-free mice were established by diethylnitrosamine (DEN) injection with feeding of high-fat high-cholesterol (HFHC) or choline-deficient high-fat (CDHF) diet. Orthotopic NAFLD-HCC allografts were established by intrahepatic injection of murine HCC cells with HFHC feeding. Metabolomic profiling was performed using liquid chromatography-mass spectrometry. Biological functions of L.acidophilus conditional medium (L.a CM) and metabolites were determined in NAFLD-HCC human cells and mouse organoids. L.acidophilus supplementation suppressed NAFLD-HCC formation in HFHC-fed DEN-treated mice. This was confirmed in orthotopic allografts and germ-free tumourigenesis mice. L.a CM inhibited the growth of NAFLD-HCC human cells and mouse organoids. The protective function of L.acidophilus was attributed to its non-protein small molecules. By metabolomic profiling, valeric acid was the top enriched metabolite in L.a CM and its upregulation was verified in liver and portal vein of L.acidophilus-treated mice. The protective function of valeric acid was demonstrated in NAFLD-HCC human cells and mouse organoids. Valeric acid significantly suppressed NAFLD-HCC formation in HFHC-fed DEN-treated mice, accompanied by improved intestinal barrier integrity. This was confirmed in another NAFLD-HCC mouse model induced by CDHF diet and DEN. Mechanistically, valeric acid bound to hepatocytic surface receptor GPR41/43 to inhibit Rho-GTPase pathway, thereby ablating NAFLD-HCC. L.acidophilus exhibits anti-tumourigenic effect in mice by secreting valeric acid. Probiotic supplementation is a potential prophylactic of NAFLD-HCC. Shown in Acknowledgments.

Cholesterol-lowering Effect of Protein Hydrolysates from Lemongrass (Cymbopogon citratus Stapf.)

Lemongrass (Cymbopogon citratus Stapf.) has been used in the Philippines for cooking and as an herb to treat a variety of ailments including hypertension and related cardiovascular diseases (CVDs). This study determined the potential of peptides obtained from the hydrolysis of lemongrass proteins to lower cholesterol in vitro and in an animal model. Proteins were extracted and digested in vitro simulating gastrointestinal conditions. Protein hydrolysates were collected and fractionated using RP-SPE column, and assayed for HMG-CoA reductase inhibitory activity against pravastatin as a control drug. Tannin-free protein extract (TFPE) and total protein hydrolysates (TPC) were administered to Sprague-Dawley rats maintained on a high-fat high-cholesterol diet for two weeks. TFPE yield was 0.03%. Simulated gastrointestinal digestion of the TFPE resulted in 74% yield of protein hydrolysates. Three fractions were obtained from RP-SPE elution of the protein hydrolysates, each with potent HMG-CoA inhibitory activity. The F3 fraction had the highest inhibition of HMG-CoA reductase (IC50 = 0.76 ppm, comparable to pravastatin (IC50 = 0.25 ppm). The inhibitory activity of the fractions was further confirmed through significant serum cholesterol reduction (p < 0.05) in Sprague-Dawley rats. Thus, protein hydrolysates from lemongrass have potential cholesterol-lowering effects in vitro through HMG-CoA reductase inhibition and in vivo through significant reduction of cholesterol levels in an animal model. Protein hydrolysates from lemongrass dietary proteins may serve as promising functional foods for the prevention of CVD risk.

Sestrin2 maintains hepatic immune homeostasis and redox balance partially via inhibiting RIPK3-mediated necroptosis in metabolic dysfunction-associated steatohepatitis

Background & aimsNecroptosis, a novel type of programmed cell death, is intricately associated with inflammatory response. Currently, most studies focus on the activation of necroptosis, while the mechanisms underlying the negative regulation of necroptosis remain poorly understood. MethodsThe effects of sestrin2 (SESN2) overexpression or knockdown on the regulation of necroptosis were assessed in the TNFα/Smac-mimetic/Z-VAD-FMK (T/S/Z)-induced necroptosis model and palmitic acid (PA)-induced lipotoxicity model. Western-blot, co-Immunoprecipitation, Glutathione S-transferase pull-down, and confocal assays were employed to explore the regulatory mechanisms including protein–protein interactions and post-translational modification. Furthermore, we used GSK'872, a specific inhibitor of receptor-interacting serine/threonine-protein kinase (RIPK) 3, to evaluate the relationship between SESN2-related alterations and RIPK3-mediated necroptosis in T/S/Z-induced necroptosis model, PA-induced lipotoxicity model, and high-fat high-cholesterol diet (HFHCD)-induced non-alcoholic steatohepatitis model. ResultsOur findings revealed that SESN2 was upregulated under conditions that induce necroptosis and functioned as a negative regulator of necroptosis. High levels of SESN2 could equipped hepatocytes with the ability to defend against necroptotic inflammation and oxidative stress. Mechanistically, SESN2 interacted with RIPK3 and tuned down necroptosis by inhibiting the phosphorylation of RIPK3, promoting the ubiquitination of RIPK3, and preventing the formation of the RIPK1/RIPK3 necrosome. The depletion of SESN2 resulted in excessive necroptosis, accompanied by increased fat accumulation, inflammation, and oxidative stress in the experimental steatohepatitis model. Blocking necroptosis by GSK’872 reduced the liberation of pro-inflammatory cytokines and reactive oxygen species generation, but not hepatocyte fat deposition, in both PA-treated SESN2 knockout cells and HFHCD-fed SESN2 knockout mice, suggesting that the activation of RIPK3-mediated necroptosis may partially account for the hyperinflammation and excessive oxidative stress induced by SESN2 deficiency. ConclusionOur results suggested that SESN2 inhibited RIPK3-mediated necroptosis; this regulation is an important for the immune homeostasis and the redox balance in the liver.

Immature carob pods extract and its fractions prevent lipid metabolism disorders and lipoprotein-rich plasma oxidation in mice: A phytochemical and pharmacological study

Ethnopharmacological relevance: In Morocco carob fruits are used traditionally to treat hypercholesterolemia, diabetes and related diseases. Aims: This study was designed to evaluate the hypolipidemic activity of Ceratonia siliqua green pods extract and its fractions in Triton WR-1339 and high fat/cholesterol diet (HFCD) induced hyperlipidemia mice, as well as their ability to prevent lipoproteins oxidation in vitro. Materials and methods: High performance liquid chromatography (HPLC) analysis was used to determine the phenolic composition of the immature carob pods extract (HWCE). Antioxidant activities were evaluated using the DPPH radical scavenging test as well as MDA measurement in oxidized lipoprotein rich plasma. Plasma lipids, glucose and biliary total cholesterol, as well as lipids level in liver and feces, were analyzed. The acute oral toxicity was performed in mice single dosed with the HWCE at 2000 and 5000 mg/kg body weight. Results: HPLC analysis shows that gallic acid is the main phenolic compound in the HWCE. The acute oral toxicity assessment revealed that the HWCE is not toxic (LD50 is greater than 5000 mg/kg body weight). In the acute hypolipidemic study, mice treated with the HWCE and its fractions exhibited a significant (P < 0.001) reduction in plasma total cholesterol (TC), triglycerides (TG) and low density lipoprotein-cholesterol (LDL-C) levels. Importantly, immature carob aqueous extract was more effective in lowering mice hypercholesterolemia than its fractions. Indeed, mice fed the HFCD for 12 weeks showed a significant raise in plasma TC, TG and LDL-C, as well as in hepatic and fecal TC and TG levels. The HWCE at 100 and 200 mg/kg body weight significantly (P < 0.001) reversed the plasmatic levels of these lipid parameters, increased plasma HDL-C level, reduced hepatic lipids accumulation, but increased cholesterol level in the bile and fecal lipids excretion. The HWCE decreased also the atherogenic index, the LDL-C/HDL-C ratio and plasma glucose level after 12 weeks’ experiment. On the other hand, the HWCE was more effective in preventing mice lipoprotein-rich plasma oxidation than its fractions, with a concentration-dependent manner. Conclusion: C. siliqua green fruits extract could be effective in preventing atherosclerosis and related cardiovascular complications through the inhibition of lipoprotein oxidation and cholesterol clearance.

Depleting LCAT Aggravates Atherosclerosis in LDLR-deficient Hamster with Reduced LDL-Cholesterol Level

IntroductionLecithin cholesterol acyltransferase (LCAT) plays a crucial role in acyl-esterifying cholesterol in plasma, which is essential for reverse cholesterol transport (RCT). Previous studies indicated that its activity on both α and β lipoproteins interpret its effects on lipoproteins for many controversial investigations of atherosclerosis. ObjectivesTo better understand the relationship between LCAT, diet-induced dyslipidemia and atherosclerosis, we developed a double knockout (LCAT−/−&LDLR−/−, DKO) hamster model to evaluate the specific role of LCAT independent of LDL clearance effects. MethodsPlasma triglyceride (TG), total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C), and free cholesterol (FC) levels were measured using biochemical reagent kits. FPLC was performed to analyze the components of lipoproteins. Apolipoprotein content was assessed using western blotting (WB). The hamsters were fed a high cholesterol/high fat diet (HCHFD) to induce atherosclerosis. Oil Red O staining was employed to detect plaque formation. Peritoneal macrophages were studied to investigate the effects of LCAT on cholesterol uptake and efflux. ResultsOn HCHFD, DKO hamsters exhibited significantly elevated levels of TG and FC, while HDL-C was nearly undetectable without affecting TC levels, as compared to low-density lipoprotein receptor (LDLR)-deficient (LDLR−/−, LKO) hamsters. Lipoprotein profiling revealed a marked increase in plasma chylomicron/very low-density lipoprotein (CM/VLDL) fractions, along with an unexpected reduction in LDL fraction in DKO hamsters. Furthermore, DKO hamsters displayed aggravated atherosclerotic lesions in the aorta, aortic root, and coronary artery relative to LKO hamsters, attributed to a pro-atherogenic lipoprotein profile and impaired cholesterol efflux in macrophages. ConclusionsOur study demonstrates the beneficial role of LCAT in inhibiting atherosclerotic development and highlights the distinctive lipid metabolism characteristics in hamsters with familial hypercholesterolemia.

Myeloid PTP1B deficiency protects against atherosclerosis by improving cholesterol homeostasis through an AMPK-dependent mechanism

ObjectiveAtherosclerosis is a chronic inflammatory process induced by the influx and entrapment of excess lipoproteins into the intima media of arteries. Previously, our lab demonstrated that systemic PTP1B inhibition protects against atherosclerosis in preclinical LDLR−/− models. Similarly, it was shown that myeloid-specific PTP1B ablation decreases plaque formation and ameliorates dyslipidaemia in the ApoE−/− model of atherosclerosis. We hypothesized that the relevant improvements in dyslipidaemia following modification of PTP1B activation may either result from changes in hepatic cholesterol biosynthesis and/or increased uptake and degradation by liver-resident macrophages. We examined this in animal models and patients with coronary artery disease.MethodsIn this study, we determined the cholesterol-lowering effect of myeloid-PTP1B deletion in mice fed a high-fat high-cholesterol diet and examined effects on total cholesterol levels and lipoprotein profiles. We also determined the effects of PTP1B inhibition to oxLDL-C challenge on foam cell formation and cholesterol efflux in human monocytes/macrophages.ResultsWe present evidence that myeloid-PTP1B deficiency significantly increases the affinity of Kupffer cells for ApoB containing lipoproteins, in an IL10-dependent manner. We also demonstrate that PTP1B inhibitor, MSI-1436, treatment decreased foam cell formation in Thp1-derived macrophages and increased macrophage cholesterol efflux to HDL in an AMPK-dependent manner. We present evidence of three novel and distinct mechanisms regulated by PTP1B: an increase in cholesterol efflux from foam cells, decreased uptake of lipoproteins into intra-lesion macrophages in vitro and a decrease of circulating LDL-C and VLDL-C in vivo.ConclusionsOverall, these results suggest that myeloid-PTP1B inhibition has atheroprotective effects through improved cholesterol handling in atherosclerotic lesions, as well as increased reverse cholesterol transport.Trial registration Research registry, researchregistry 3235. Registered 07 November 2017, https://www.researchregistry.com/browse-the-registry#home/registrationdetails/5a01d0fce7e1904e93e0aac5/.

Edible Bird’s Nest Effectively Attenuates Atherosclerosis through Modulation of Cholesterol Metabolism via Activation of PPARγ/LXRα Signaling Pathway In Vivo

Atherosclerosis is the underlying cause of the majority of cardiovascular diseases (CVDs) due to high-cholesterol deposition in the aorta, resulting in hardening and narrowing of blood vessels and subsequently leading to an obstructed blood flow. There are few previous publications showing the preventive effects of edible bird’s nest (EBN) on CVD, but the study on cholesterol homeostasis related to atherosclerosis is limited. In this study, we have determined the mechanisms by which EBN modulates cholesterol metabolism by identifying genes and biomarkers. Male New Zealand white rabbits were fed either a high-fat high-cholesterol (HFC) diet or a HFC diet supplemented with EBN (500 mg/kg b.w/day) for 12 weeks. For comparison purposes, a group of rabbits receiving a HFC diet was supplemented with simvastatin (10 mg/kg b.w/day) as a standard drug treatment for hypercholesterolemia. EBN supplementation significantly improved lipid and coagulation profiles, reduced hepatosteatosis, and stabilized atherosclerotic plaque formation in hypercholesterolemic rabbits. Cholesterol accumulation in liver and aorta tissues, as well as hepatic HMGCR levels, was reduced in the hypercholesterolemic rabbits supplemented with EBN. Gene expression analysis showed that EBN induced many genes related to cholesterol uptake (LDLR, LOX-1, and CD36), cholesterol efflux (ABCA1, LCAT, and CYP7A1), and cholesterol-sensing signaling (LXRα and PPARγ). In conclusion, our studies suggest that EBN supplementation could be an effective food product for the treatment or prevention of atherosclerosis by regulating cholesterol metabolism.