High-fat Diet-induced Mouse Model Research Articles

Ileal microbial microbiome and its secondary bile acids modulate susceptibility to nonalcoholic steatohepatitis in dairy goats

BackgroundLiver damage from nonalcoholic steatohepatitis (NASH) presents a significant challenge to the health and productivity of ruminants. However, the regulatory mechanisms behind variations in NASH susceptibility remain unclear. The gut‒liver axis, particularly the enterohepatic circulation of bile acids (BAs), plays a crucial role in regulating the liver diseases. Since the ileum is the primary site for BAs reabsorption and return to the liver, we analysed the ileal metagenome and metabolome, liver and serum metabolome, and liver single-nuclei transcriptome of NASH-resistant and susceptible goats together with a mice validation model to explore how ileal microbial BAs metabolism affects liver metabolism and immunity, uncovering the key mechanisms behind varied NASH pathogenesis in dairy goats.ResultsIn NASH goats, increased total cholesterol (TC), triglyceride (TG), and primary BAs and decreased secondary BAs in the liver and serum promoted hepatic fat accumulation. Increased ileal Escherichia coli, Erysipelotrichaceae bacterium and Streptococcus pneumoniae as well as proinflammatory compounds damaged ileal histological morphology, and increased ileal permeability contributes to liver inflammation. In NASH-tolerance (NASH-T) goats, increased ursodeoxycholic acid (UDCA), isodeoxycholic acid (isoDCA) and isolithocholic acid (isoLCA) in the liver, serum and ileal contents were attributed to ileal secondary BAs-producing bacteria (Clostridium, Bifidobacterium and Lactobacillus) and key microbial genes encoding enzymes. Meanwhile, decreased T-helper 17 (TH17) cells and increased regulatory T (Treg) cells proportion were identified in both liver and ileum of NASH-T goats. To further validate whether these key BAs affected the progression of NASH by regulating the proliferation of TH17 and Treg cells, the oral administration of bacterial UDCA, isoDCA and isoLCA to a high-fat diet-induced NASH mouse model confirmed the amelioration of NASH through the TH17 cell differentiation/IL-17 signalling/PPAR signalling pathway by these bacterial secondary BAs.ConclusionThis study revealed the roles of ileal microbiome and its secondary BAs in resilience and susceptibility to NASH by affecting the hepatic Treg and TH17 cells proportion in dairy goats. Bacterial UDCA, isoDCA and isoLCA were demonstrated to alleviate NASH and could be novel postbiotics to modulate and improve the liver health in ruminants.A8SM95maBgMZc1-WqV_tnDVideo

Blood circulation effect of fermented citrus bioconversion product (FCBP) in EA.hy926 endothelial cells and high-fat diet-fed mouse model.

The escalating global burden of cardiovascular diseases, largely driven by unhealthy lifestyle choices and dietary patterns, has intensified the search for effective and safe interventions. With current treatments often marred by significant side effects, the exploration of natural compounds such as flavonoids presents a compelling alternative. This study investigated the effects of fermented citrus bioconversion product (FCBP), a fermented citrus bioflavonoid, on various markers of cardiovascular health in the context of a high-fat diet. In vivo, a high-fat diet-induced mouse model was used to assess the effects of FCBP on body weight, serum nitric oxide (NO) levels, activated partial thromboplastin time (aPTT), phosphatidylserine (PS) exposure on red blood cells, and the expression of inflammatory markers Intercellular Adhesion Molecule (ICAM)-1 and Vascular Cell Adhesion Molecule (VCAM)-1 in the thoracic aorta. In vitro, EA.hy926 endothelial cells were used to evaluate the compound's effects on cell viability, NO production, endothelial nitric oxide synthase (eNOS) expression, and cell adhesion molecule (CAM) levels to further understand the mechanisms behind the in vivo findings. In vivo, FCBP supplementation led to a dose-dependent reduction in weight gain, a significant decrease in serum NO levels at 10 mg/kg, and reduced ICAM-1 and VCAM-1 expressions in the thoracic aorta, indicating anti-inflammatory properties. PS exposure on red blood cells was also reduced, suggesting decreased procoagulant activity, while aPTT remained unchanged. In vitro, FCBP was non-cytotoxic to endothelial cells, showed a trend toward increased NO production and eNOS expression, and reduced the expression of ICAM-1 and VCAM-1, supporting its potential anti-inflammatory effects. FCBP demonstrates potential as a bioactive compound for managing cardiovascular health by reducing inflammation, mitigating weight gain, and influencing blood circulation-related parameters under high-fat diet conditions. Further studies, including diverse models and human trials, are warranted to elucidate its mechanisms and compare its efficacy with established cardiovascular therapeutics.

Qinlian Hongqu Decoction Modulates FXR/TGR5/GLP-1 Pathway to Improve Insulin Resistance in NAFLD Mice: Bioinformatics and Experimental Study.

Background: Qinglian Hongqu decoction (QLHQD), a traditional Chinese herbal remedy, shows potential in alleviating metabolic issues related to nonalcoholic fatty liver disease (NAFLD). However, its precise mode of action remains uncertain. Objective: This study aims to evaluate the efficacy and mechanisms of QLHQD in treating NAFLD. Methods: This study utilized a NAFLD mouse model to assess the effects of QLHQD on lipid metabolism, including blood lipids and hepatic steatosis, as well as glucose metabolism, including blood glucose levels, OGTT results, and serum insulin. Network pharmacology, bioinformatics, and molecular docking were used to explore how QLHQD may improve NAFLD treatment. Key proteins involved in these mechanisms were validated via WB and immunohistochemistry. Additionally, the expression of downstream pathway targets was examined to further validate the insulin resistance mechanism by which QLHQD improves NAFLD. Results: Animal studies demonstrated that QLHQD alleviated lipid abnormalities, hepatic steatosis, blood glucose levels, the insulin resistance index, and the OGTT results in NAFLD mice (P < 0.05 or 0.01). Network pharmacology and bioinformatics analyses indicated that the effects of QLHQD on NAFLD might involve bile acid secretion pathways. Subsequent validation through Western blotting, immunohistochemistry, and qPCR demonstrated that QLHQD may influence fat metabolism and insulin sensitivity in NAFLD mice via the FXR/TGR5/GLP-1 signaling pathway. Conclusion: QLHQD significantly alleviates glucose and lipid metabolism disorders in a high-fat diet-induced NAFLD mouse model. Its mechanism of action may involve the activation of the FXR/TGR5/GLP-1 signaling pathway in the gut, which reduces lipid accumulation and insulin resistance.

Circ-ADAM9 Knockdown Reduces Insulin Resistance and Placental Injury in Diabetic Mice via MAPK Pathway Inactivation.

Gestational diabetes mellitus (GDM) significantly risks maternal and neonatal health. Circular RNAs (circRNAs) regulate various diseases but their role in GDM is unclear. We investigated the involvement of circ-ADAM9 in GDM. We analyzed circ-ADAM9 expression in GDM-related microarray data (GSE182737) and measured its levels in the blood of GDM patients. In a high-fat diet-induced GDM mouse model, we inhibited circ-ADAM9 expression and tracked blood glucose levels, serum insulin, lipid levels, placental apoptosis, and reactive oxygen species (ROS) levels. Pathological changes in pancreatic tissues and fetal outcomes were also examined. Molecular interactions were explored using bioinformatics tools and validated through luciferase assays, real-time quantitative polymerase chain reaction (RT-qPCR), and Western blotting in high glucose (HG)-induced human trophoblast cells (HTR-8/SVneo). We further investigated the involvement of circ-ADAM9/miR-375/FPR2 axis in HG-induced injury in HTR-8/SVneo cells by assessing cell viability, apoptosis, ROS production, and antioxidant levels. Both GDM patients and GDM-induced mice exhibited a substantial upregulation of circ-ADAM9. Knockdown of circ-ADAM9 lowered blood glucose, alleviated insulin resistance, improved lipid metabolism, decreased placental apoptosis and ROS levels, and reduced pancreatic lesions in GDM mice. Circ-ADAM9 downregulation also improved fetal viability, weight, and crown-rump length. In HG-induced HTR-8/SVneo cells, circ-ADAM9 overexpression and miR-375 downregulation were evident. Overexpression of miR-375 inhibited circ-ADAM9 activity, substantiating their binding interaction. In GDM mice, circ-ADAM9 deficiency restored miR-375 expression. TargetScanHuman predicted and luciferase assays confirmed the miR-375-FPR2 interaction and elevated FPR2 levels in GDM mice were reduced by circ-ADAM9 silencing. In HG-induced HTR-8/SVneo cells, circ-ADAM9 knockdown restored cell viability, suppressed apoptosis and ROS levels, and enhanced antioxidant enzyme levels. These effects were reversed by miR-375 inhibition or FPR2 overexpression, suggesting circ-ADAM9 upregulates FPR2 expression by sponging miR-375 and modulating the MAPK pathway. This study is the first to demonstrate the expression and function of circ-ADAM9 in the progression of GDM. Circ-ADAM9 downregulation ameliorates insulin resistance and placental injury in GDM by modulating the miR-375/FPR2 axis and inactivating the MAPK pathway, which may offer a novel therapeutic target for the treatment of GDM.

Asperuloside activates hepatic NRF2 signaling to stimulate mitochondrial metabolism and restore lipid homeostasis in high fat diet-induced MAFLD

BackgroundNutrient overload predisposes the development of metabolic dysfunction-associated fatty liver disease (MAFLD). However, there are no specific pharmacological therapies for MAFLD. Asperuloside (ASP), an iridoid glycoside extracted from Eucommia ulmoides leaves, can alleviate obesity and MAFLD. However, the underlying mechanism and pharmacological effects of ASP on ameliorating MAFLD remain largely investigated. This study aimed to explore the effects of ASP in ameliorating MAFLD and to unravel its underlying mechanism using a high fat diet-induced MAFLD mice model. MethodsSix-week-old C57BL/6 male mice were fed a high fat diet for 12 weeks to induce MAFLD, followed by daily ASP treatment (50 mg/kg via oral gavage) for 7 weeks. HepG2 cells were used for in vitro studies. Nuclear factor erythroid 2-related factor 2 (Nrf2) inhibitor, ML385, was employed to explore the mechanisms of ASP's action. ResultsASP stimulated lipolysis and inhibited de novo lipogenesis, contributing to alleviating lipid deposition in obese mice livers and HepG2 cells. ASP restored ATP production and reversed the impairments of mitochondrial energetics and biogenesis in obese mice livers and HepG2 cells. ASP attenuated oxidative stress in obese mice livers and HepG2 cells, exhibiting its antioxidant value. Impressively, ASP significantly promotes Nrf2 nuclear translocation and Nrf2/ARE binding, thereby activating Nrf2/ARE pathway in obese mice livers and HepG2 cells, demonstrating its potential as a hepatic Nrf2 activator. Nrf2 inhibition abolishes the protective effects of ASP against lipid deposition, oxidative stress and mitochondrial dysfunction, emphasizing the critical role of ASP-activated hepatic Nrf2 signaling in ameliorating MAFLD. ConclusionsThis study provides the first line of evidence demonstrating the pivotal role of ASP-stimulated Nrf2 activation in alleviating MAFLD, emphasizing its potential as a hepatic Nrf2 activator targeting fatty liver diseases. These findings offer new evidence of ASP-stimulated mitochondrial metabolism and lipolysis in MAFLD, paving the way for the development of ASP as a therapeutic agent and dietary supplement to attenuate MAFLD progression.

Exploration of the potential mechanism of aqueous extract of Artemisia capillaris for the treatment of non-alcoholic fatty liver disease based on network pharmacology and experimental verification.

Non-alcoholic fatty liver disease (NAFLD) is a nutritional and metabolic disease with a high prevalence today. Artemisia capillaris has anti-inflammatory, antioxidant, and other effects. However, the mechanism of A. capillaris in treating NAFLD is still poorly understood. This study explored the mechanism of A. capillaris in the treatment of NAFLD through network pharmacology and molecular docking, and verified the results through in vivo experiments using a high-fat diet-induced mouse model and in vitro experiments using an oleic acid-induced HepG2 cell model. Aqueous extract of A. capillaris (AEAC) can reduce blood lipids, reduce liver lipid accumulation and liver inflammation in NAFLD mice, and improve NAFLD. Network pharmacology analysis revealed that 51 drug ingredients in A. capillaris correspond to 370 targets that act on NAFLD. GEO data mining obtained 93 liver differentially expressed genes related to NAFLD. In the UHPLC-MS detection results, 36 components were characterized and molecular docked with JNK. Verified in vitro and in vivo, the results show that JNK and the phosphorylation levels of IL-6, IL-1β, c-Jun, c-Fos, and CCL2 are key targets and pathways. This study confirmed that AEAC reduces lipid accumulation and inflammation in the liver of NAFLD mice by inhibiting the JNK/AP-1 pathway.

Ebselen improves lipid metabolism by activating PI3K/Akt and inhibiting TLR4/JNK signaling pathway to alleviate nonalcoholic fatty liver

Nonalcoholic fatty liver disease (NAFLD), a metabolic disease associated with obesity and type 2 diabetes. Due to its complex pathogenesis, there are still limitations in the knowledge of the disease. To date, no drug has been approved to treat NAFLD. This study aims to explore the role and mechanism of Ebselen (EbSe) in NAFLD. A high-fat diet-induced mouse model of NAFLD was employed to investigate EbSe function in NAFLD mice by EbSe gavage and to regularly monitor the mouse body weight. HE and oil red O staining were performed, respectively, to detect the pathological damage and lipid accumulation in mouse liver tissues. The biochemical and ELISA kits were employed to measure the levels of ALT, AST, TG, TC, LDL-C, HDL-C and pro-inflammatory cytokines within mouse serum or liver tissue. The expression of key proteins of PPARα, fatty acid β oxidation-related protein, PI3K/Akt and TLR4/JNK signaling pathway was detected by western blot. EbSe significantly downregulated body weight, liver weight and liver lipid accumulation in NAFLD mice and downregulated ALT, AST, TG, TC, LDL-C and increased HDL-C serum levels. EbSe upregulated the expression levels of PPARα and fatty acid β oxidation-associated proteins CPT1α, ACOX1, UCP2 and PGC1α. EbSe promoted Akt and PI3K phosphorylation, and inhibited TLR4 expression and JNK phosphorylation. EbSe can upregulate PPARα to promote fatty acid β-oxidation and improve hepatic lipid metabolism. Meanwhile, EbSe also activated PI3K/Akt and inhibited TLR4/JNK signaling pathway. EbSe is predicted to be an effective therapeutic drug for treating NAFLD.

Amelioration of Insulin Resistance by Whey Protein in a High-Fat Diet-Induced Pediatric Obesity Male Mouse Model.

This study examined whey protein's impact on insulin resistance in a high-fat diet-induced pediatric obesity mouse model. Pregnant mice were fed high-fat diets, and male pups continued this diet until 8 weeks old, then were split into high-fat, whey, and casein diet groups. At 12 weeks old, their body weight, fasting blood glucose (FBG), blood insulin level (IRI), homeostatic model assessment for insulin resistance (HOMA-IR), liver lipid metabolism gene expression, and liver metabolites were compared. The whey group showed significantly lower body weight than the casein group at 12 weeks old (p = 0.034). FBG was lower in the whey group compared to the high-fat diet group (p < 0.01) and casein group (p = 0.058); IRI and HOMA-IR were reduced in the whey group compared to the casein group (p = 0.02, p < 0.01, p < 0.01, respectively). The levels of peroxisome proliferator-activated receptor α and hormone-sensitive lipase were upregulated in the whey group compared to the casein group (p < 0.01, p = 0.03). Metabolomic analysis revealed that the levels of taurine and glycine, both known for their anti-inflammatory and antioxidant properties, were upregulated in the whey group in the liver tissue (p < 0.01, p < 0.01). The intake of whey protein was found to improve insulin resistance in a high-fat diet-induced pediatric obesity mouse model.

MicroRNA-721 regulates gluconeogenesis via KDM2A-mediated epigenetic modulation in diet-induced insulin resistance in C57BL/6J mice

BackgroundAberrant gluconeogenesis is considered among primary drivers of hyperglycemia under insulin resistant conditions, with multiple studies pointing towards epigenetic dysregulation. Here we examine the role of miR-721 and effect of epigenetic modulator laccaic acid on the regulation of gluconeogenesis under high fat diet induced insulin resistance.ResultsReanalysis of miRNA profiling data of high-fat diet-induced insulin-resistant mice model, GEO dataset (GSE94799) revealed a significant upregulation of miR-721, which was further validated in invivo insulin resistance in mice and invitro insulin resistance in Hepa 1–6 cells. Interestingly, miR-721 mimic increased glucose production in Hepa 1–6 cells via activation of FOXO1 regulated gluconeogenic program. Concomitantly, inhibition of miR-721 reduced glucose production in palmitate induced insulin resistant Hepa 1–6 cells by blunting the FOXO1 induced gluconeogenesis. Intriguingly, at epigenetic level, enrichment of the transcriptional activation mark H3K36me2 got decreased around the FOXO1 promoter. Additionally, identifying targets of miR-721 using miRDB.org showed H3K36me2 demethylase KDM2A as a potential target. Notably, miR-721 inhibitor enhanced KDM2A expression which correlated with H3K36me2 enrichment around FOXO1 promoter and the downstream activation of the gluconeogenic pathway. Furthermore, inhibition of miR-721 in high-fat diet-induced insulin-resistant mice resulted in restoration of KDM2A levels, concomitantly reducing FOXO1, PCK1, and G6PC expression, attenuating gluconeogenesis, hyperglycemia, and improving glucose tolerance. Interestingly, the epigenetic modulator laccaic acid also reduced the hepatic miR-721 expression and improved KDM2A expression, supporting our earlier report that laccaic acid attenuates insulin resistance by reducing gluconeogenesis.ConclusionOur study unveils the role of miR-721 in regulating gluconeogenesis through KDM2A and FOXO1 under insulin resistance, pointing towards significant clinical and therapeutic implications for metabolic disorders. Moreover, the promising impact of laccaic acid highlights its potential as a valuable intervention in managing insulin resistance-associated metabolic diseases.Graphical

The prostaglandin E2 EP3 receptor has disparate effects on islet insulin secretion and content in β-cells in a high-fat diet-induced mouse model of obesity.

Signaling through prostaglandin E2 EP3 receptor (EP3) actively contributes to the β-cell dysfunction of type 2 diabetes (T2D). In T2D models, full-body EP3 knockout mice have a significantly worse metabolic phenotype than wild-type controls due to hyperphagia and severe insulin resistance resulting from loss of EP3 in extra-pancreatic tissues, masking any potential beneficial effects of EP3 loss in the β cell. We hypothesized β-cell-specific EP3 knockout (EP3 βKO) mice would be protected from high-fat diet (HFD)-induced glucose intolerance, phenocopying mice lacking the EP3 effector, Gαz, which is much more limited in its tissue distribution. When fed a HFD for 16 wk, though, EP3 βKO mice were partially, but not fully, protected from glucose intolerance. In addition, exendin-4, an analog of the incretin hormone, glucagon-like peptide 1, more strongly potentiated glucose-stimulated insulin secretion in islets from both control diet- and HFD-fed EP3 βKO mice as compared with wild-type controls, with no effect of β-cell-specific EP3 loss on islet insulin content or markers of replication and survival. However, after 26 wk of diet feeding, islets from both control diet- and HFD-fed EP3 βKO mice secreted significantly less insulin as a percent of content in response to stimulatory glucose, with or without exendin-4, with elevated total insulin content unrelated to markers of β-cell replication and survival, revealing severe β-cell dysfunction. Our results suggest that EP3 serves a critical role in temporally regulating β-cell function along the progression to T2D and that there exist Gαz-independent mechanisms behind its effects.NEW & NOTEWORTHY The EP3 receptor is a strong inhibitor of β-cell function and replication, suggesting it as a potential therapeutic target for the disease. Yet, EP3 has protective roles in extrapancreatic tissues. To address this, we designed β-cell-specific EP3 knockout mice and subjected them to high-fat diet feeding to induce glucose intolerance. The negative metabolic phenotype of full-body knockout mice was ablated, and EP3 loss improved glucose tolerance, with converse effects on islet insulin secretion and content.

Machine learning deciphers the significance of mitochondrial regulators on the diagnosis and subtype classification in non-alcoholic fatty liver disease

BackgroundNon-alcoholic fatty liver disease (NAFLD) is a highly prevalent liver disease worldwide and lack of research on the diagnostic utility of mitochondrial regulators in NAFLD. Mitochondrial dysfunction plays a pivotal role in the development and progression of NAFLD, especially oxidative stress and acidity β-oxidative overload. Thus, we aimed to identify and validate a panel of mitochondrial gene expression biomarkers for detection of NAFLD. MethodsWe selected the GSE89632 dataset and identified key mitochondrial regulators by intersecting DEGs, WGCNA modules, and MRGs. Classification of NAFLD subtypes based on these key mitochondrial regulatory factors was performed, and the pattern of immune system infiltration in different NAFLD subtypes were also investigated. RF, LASSO, and SVM-RFE were employed to identify possible diagnostic biomarkers from key mitochondrial regulatory factors and the predictive power was demonstrated through ROC curves. Finally, we validated these potential diagnostic biomarkers in human peripheral blood samples and a high-fat diet-induced NAFLD mouse model. ResultsWe identified 25 key regulators of mitochondria and two NAFLD subtypes with different immune infiltration patterns. Four potential diagnostic biomarkers (BCL2L11, NAGS, HDHD3, and RMND1) were screened by three machine learning methods thereby establishing the diagnostic model, which showed favorable predictive power and achieved significant clinical benefit at certain threshold probabilities. Then, through internal and external validation, we identified and confirmed that BCL2L11 was significantly downregulated in NAFLD, while the other three were significantly upregulated. ConclusionThe four MRGs, namely BCL2L11, NAGS, HDHD3, and RMND1, are novel potential biomarkers for diagnosing NAFLD. A diagnostic model constructed using the four MRGs may aid early diagnosis of NAFLD in clinics.

Anti-obesity potentiality of Lactiplantibacillus plantarum E2_MCCKT isolated from a fermented beverage, haria: a high fat diet-induced obese mice model study.

Obesity is a growing epidemic worldwide. Several pharmacologic drugs are being used to treat obesity but these medicines exhibit side effects. To find out the alternatives of these drugs, we aimed to assess the probiotic properties and anti-obesity potentiality of a lactic acid bacterium E2_MCCKT, isolated from a traditional fermented rice beverage, haria. Based on the 16S rRNA sequencing, the bacterium was identified as Lactiplantibacillus plantarum E2_MCCKT. The bacterium exhibited in vitro probiotic activity in terms of high survivability in an acidic environment and 2% bile salt, moderate auto-aggregation, and hydrophobicity. Later, E2_MCCKT was applied to obese mice to prove its anti-obesity potentiality. Adult male mice (15.39 ± 0.19g) were randomly divided into three groups (n = 5) according to the type of diet: normal diet (ND), high-fat diet (HFD), and HFD supplemented with E2_MCCKT (HFT). After four weeks of bacterial treatment on the obese mice, a significant reduction of body weight, triglyceride, and cholesterol levels, whereas, improvements in serum glucose levels were observed. The bacterial therapy led to mRNA up-regulation of lipolytic transcription factors such as peroxisome proliferator-activated receptor-α which may increase the expression of fatty acid oxidation-related genes such as acyl-CoA oxidase and carnitine palmitoyl-transferase-1. Concomitantly, both adipocytogenesis and fatty acid synthesis were arrested as reflected by the down-regulation of sterol-regulatory element-binding protein-1c, acetyl-CoA carboxylase, and fatty acid synthase genes. In protein expression study, E2_MCCKT significantly increased IL-10 expression while decreasing pro-inflammatory cytokine (IL-1Ra and TNF-α) expression. In conclusion, the probiotic Lp. plantarum E2_MCCKT might have significant anti-obesity effects on mice.

Conjugated Linoleic Acid Ameliorates High Fat-Induced Insulin Resistance via Regulating Gut Microbiota-Host Metabolic and Immunomodulatory Interactions.

Interaction between gut microbiota, host immunity and metabolism has been suggested to crucially affect the development of insulin resistance (IR). This study aims to investigate how gut microbiota, inflammatory responses and metabolism in individuals with IR are affected by the supplementation of conjugated linoleic acid (CLA) and how this subsequently affects the pathophysiology of IR by using a high-fat diet-induced IR mouse model. Serum biochemical indices showed that 400 mg/kg body weight of CLA effectively attenuated hyperglycemia, hyperlipidemia, glucose intolerance and IR, while also promoting antioxidant capacities. Histomorphology, gene and protein expression analysis revealed that CLA reduced fat deposition and inflammation, and enhanced fatty acid oxidation, insulin signaling and glucose transport in adipose tissue or liver. Hepatic transcriptome analysis confirmed that CLA inhibited inflammatory signaling pathways and promoted insulin, PI3K-Akt and AMPK signaling pathways, as well as linoleic acid, arachidonic acid, arginine and proline metabolism. Gut microbiome analysis further revealed that these effects were highly associated with the enriched bacteria that showed positive correlation with the production of short-chain fatty acids (SCFAs), as well as the improved SCFAs production simultaneously. This study highlights the therapeutic actions of CLA on ameliorating IR via regulating microbiota-host metabolic and immunomodulatory interactions, which have important implications for IR control.

Lipidomic Analysis of Liver and Adipose Tissue in a High-Fat Diet-Induced Non-Alcoholic Fatty Liver Disease Mice Model Reveals Alterations in Lipid Metabolism by Weight Loss and Aerobic Exercise.

Detailed investigation of the lipidome remodeling upon normal weight conditions, obesity, or weight loss, as well as the influence of physical activity, can help to understand the mechanisms underlying dyslipidemia in metabolic conditions correlated to the emergence and progression of non-alcoholic fatty liver disease (NAFLD). C57BL/6 male mice were fed a normal diet (ND) or a high-fat diet (HFD) for 20 weeks. Subgroups within the high-fat diet (HFD) group underwent different interventions: some engaged in exercise (HFDex), others were subjected to weight loss (WL) by changing from the HFD to ND, and some underwent a combination of weight loss and exercise (WLex) during the final 8 weeks of the 20-week feeding period. To support our understanding, not only tissue-specific lipid remodeling mechanisms but also the cross-talk between different tissues and their impact on the systemic regulation of lipid metabolism are essential. Exercise and weight loss-induced specific adaptations in the liver and visceral adipose tissue lipidomes of mice were explored by the UPLC-TOF-MS/MS untargeted lipidomics methodology. Lipidomic signatures of ND and HFD-fed mice undergoing weight loss were compared with animals with and without physical exercise. Several lipid classes were identified as contributing factors in the discrimination of the groups by multivariate analysis models, such as glycerolipids, glycerophospholipids, sphingolipids, and fatty acids, with respect to liver samples, whereas triglycerides were the only lipid class identified in visceral adipose tissue. Lipids found to be dysregulated in HFD animals are related to well-established pathways involved in the biosynthesis of PC, PE, and TG metabolism. These show a reversing trend back to basic levels of ND when animals change to a normal diet after 12 weeks, whereas the impact of exercise, though in some cases it slightly enhances the reversing trend, is not clear.

Comparative analysis of anti-obesity effects of green, fermented, and γ-aminobutyric acid teas in a high-fat diet-induced mouse model

Obesity, a prevalent disease associated with numerous chronic conditions, including hyperlipidemia, hyperglycemia, diabetes, and metabolic syndrome, remains a major global health challenge. This study investigated the potential of green tea (GT), fermented tea (FT), and γ-aminobutyric acid (GABA) tea (GBT), which are rich in phytonutrients and polyphenols, for the management of obesity. Using a high-fat diet-induced obese mouse model (C57BL/6N), we explored the effect of these teas on various obesity-related parameters. The mice were categorized into five groups: normal diet with water, high-fat diet with water, and high-fat diet supplemented with GT, FT, or GBT. Over 13 weeks, we monitored body weight, perirenal and liver fat, adipocyte lipid accumulation, and key metabolic indicators, such as serum cholesterol, leptin, insulin, and fasting blood glucose. These teas contain beneficial phytochemicals such as GABA, theanine, and caffeine, and have demonstrated an enhanced antioxidant capacity, which increases the scavenging of free radicals and may reduce oxidative stress. The animal study indicated a decrease in feeding efficiency and significant reductions in body weight liver fat, epididymal fat, and perirenal fat, as well as in adipocyte lipid accumulation. Additionally, notable improvements were observed in metabolic health indicators, including reductions in serum cholesterol, leptin, insulin, and fasting blood glucose levels. Our findings revealed that GT, FT, or GBT significantly counteracted the negative effects of a high-fat diet, suggesting their potential in combating obesity and related metabolic disorders.

Abstract 574: Adipocyte-derived FABP4 promotes non-alcoholic fatty liver disease (NAFLD)-induced hepatocellular carcinoma by driving ITGB1-mediated β-catenin activation

Abstract Nonalcoholic fatty liver disease (NAFLD)-induced hepatocellular carcinoma (HCC) is an emerging malignancy in the developed countries. However, the mechanisms contributing to its formation remain largely unknown. Given the role of cancer stem cells (CSCs) in tumor initiation and therapeutic resistance, we hypothesize that adipocytes, one of the key cellular factors within the tumor microenvironment of NAFLD-induced HCC, may play a critical role in HCC development and drug resistance by regulating liver CSCs. Using a co-culture system in which differentiated adipocytes were grown with HCC cells, we found that adipocytes enhanced the self-renewal ability of HCC cells through indirect paracrine secretion. HCC cells pre-incubated with conditioned medium from adipocytes showed enhanced liver CSC properties including self-renewal, tumorgenicity, invasiveness and chemo-resistance to doxorubicin and sorafenib. Secretome profiles showed that FABP4 was preferentially secreted by adipocytes and its level was further augmented when co-cultured with HCC cells. Concurrently, recombinant FABP4 enhanced CSC properties of HCC cells. Drastic delay in the onset of tumor development in FABP4−/- mice upon DEN-injected and high fat diet-induced mouse models of NAFLD-HCC. Mass spectrometry analysis revealed ITGB1 as a direct binding partner of FABP4 for the first time. This data, together with the observation of significant downregulation of the Wnt/β-catenin pathway in tumors of FABP4−/− mice, revealed the role of adipocyte-derived FABP4 promotes liver CSC function by activating the PI3K/Akt/β-catenin signaling pathway via ITGB1. Overexpression of ITGB1 led to poorer survival of HCC patients with NAFLD as a risk factor. The development of a monoclonal neutralizing antibody against FABP4 successfully blocked FABP4-driven CSC functions, implicating the targetability of FABP4 for the treatment of NAFLD-induced HCC. Citation Format: Carmen Oi Ning Leung, Shilpa Gurung, Katherine Po Sin Chung, Sze Man Chan, Terence Kin Wah Lee. Adipocyte-derived FABP4 promotes non-alcoholic fatty liver disease (NAFLD)-induced hepatocellular carcinoma by driving ITGB1-mediated β-catenin activation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 574.

Platycodi Radix Extract Prevents Hepatic Steatosis by Enhancing Bile Acid Synthesis in a High-Fat Diet-Induced Fatty Liver Mouse Model.

We aimed to identify the mechanism underlying the preventive effects of non-alcoholic fatty liver disease (NAFLD) through Platycodi Radix consumption using liver proteomic and bioinformatic analysis. C57BL/6J mice were categorized into three groups: those receiving a standard chow diet (NCD), those on a high-fat diet (HFD), and those on an HFD supplemented with 5% Platycodi Radix extract (PRE). After a 12-week period, PRE-fed mice exhibited a noteworthy prevention of hepatic steatosis. Protein identification and quantification in liver samples were conducted using LC-MS/MS. The identified proteins were analyzed through Ingenuity Pathway Analysis software, revealing a decrease in proteins associated with FXR/RXR activation and a concurrent increase in cholesterol biosynthesis proteins in the PRE-treated mouse liver. Subsequent network analysis predicted enhanced bile acid synthesis from these proteins. Indeed, the quantity of bile acids, which was reduced in HFD conditions, increased in the PRE group, accompanied by an elevation in the expression of synthesis-related proteins. Our findings suggest that the beneficial effects of PRE in preventing hepatic steatosis may be mediated, at least in part, through the modulation of FXR/RXR activation, cholesterol biosynthesis, and bile acid synthesis pathways.

Rosae multiflorae fructus regulates the lipogenesis in high-fat diet-induced NAFLD mice model.

Exercise helps modify the lipid profile in the body, partly through its impact on sterol regulatory element binding protein-1 (SREBP-1) and peroxisome proliferator-activated receptor-γ (PPAR-γ). Individual differences in response to exercise and genetic variations may influence the response to PA. Therefore, this study explored Rosae multiflorae fructus (RMF) as a supplement candidate that improves exercise capacity and controls non-alcoholic fatty liver disease (NAFLD) by suppressing lipogenesis and controlling lipid peroxidation. RMF is a natural herbal medicine used in Dongui Bogam. RMF has antioxidant, anti-inflammatory, and anti-allergic effects. However, the effects of RMF on NAFLD have not yet been investigated. In this study, we examined the effects of RMF in a mouse model of high-fat diet-induced NAFLD. Mouse livers were isolated and analyzed using H&amp;E staining and immunohistochemistry. RMF downregulated lipid peroxidation markers, such as CYP2E1, in the livers of mice with high-fat diet-induced NAFLD. Additionally, the RMF significantly reduced the lipid accumulation-related protein expression of CD36, SREBP-1, and PPAR-γ. RMF exerts anti-lipid peroxidation and anti-lipogenic effects in a high-fat diet-induced NAFLD mouse model.

Artemether Attenuates Gut Barrier Dysfunction and Intestinal Flora Imbalance in High-Fat and High-Fructose Diet-Fed Mice

Intestinal inflammation is a key determinant of intestinal and systemic health, and when our intestines are damaged, there is disruption of the intestinal barrier, which in turn induces a systemic inflammatory response. However, the etiology and pathogenesis of inflammatory diseases of the intestine are still not fully understood. Artemether (ART), one of the artemisinin derivatives, has been widely used to treat malaria. Nevertheless, the effect of ART on intestinal inflammation remains unclear. The present study intended to elucidate the potential mechanism of ART in diet-induced intestinal injury. A high-fat and high-fructose (HFHF) diet-induced mouse model of intestinal injury was constructed, and the mice were treated with ART to examine their role in intestinal injury. RT-qPCR, Western blotting, immunohistochemical staining, and 16S rRNA gene sequencing were used to investigate the anti-intestinal inflammation effect and mechanism of ART. The results indicated that ART intervention may significantly ameliorate the intestinal flora imbalance caused by the HFHF diet and alleviate intestinal barrier function disorders and inflammatory responses by raising the expression of tight junction proteins ZO-1 and occludin and decreasing the expression of pro-inflammatory factors TNF-α and IL-1β. Moreover, ART intervention restrained HFHF-induced activation of the TLR4/NF-κB p65 pathway in colon tissue, which may be concerned with the potential protective effect of ART on intestinal inflammation. ART might provide new insights into further explaining the mechanism of action of other metabolic diseases caused by intestinal disorders.

Thrombospondin1 antagonist peptide treatment attenuates obesity-associated chronic inflammation and metabolic disorders in a diet-induced obese mouse model

Thrombospondin1 (TSP1) is a multifunctional matricellular protein. Previously, we demonstrated that TSP1 plays a pivotal role in obesity-related inflammation and insulin resistance (IR) by modulating macrophage accumulation and activation in adipose tissue. Moreover, in our in vitro studies, a CD36-derived peptide, functioning as a TSP1 antagonist, effectively inhibited TSP1-induced proinflammatory macrophage activation. However, whether this CD36 peptide can inhibit obesity-induced inflammation and IR in vivo is unknown and determined in this study in a high fat diet-induced obese mouse model (DIO). CD36 peptide or control peptide was intraperitoneally administered into the established obese mice triweekly for 6 weeks. We found that CD36 peptide treatment didn’t affect obesity or weight gain but significantly reduced proinflammatory cytokine production systemically and in visceral fat tissue. Adipose tissue exhibited fewer crown-like structures and reduced macrophage infiltration. CD36 peptide treatment also attenuated the proinflammatory phenotype of bone marrow derived macrophages from obese mice. Furthermore, CD36 peptide treatment improved glucose tolerance and insulin sensitivity, and mitigated obesity-related fatty liver disease and kidney damage. Collectively, this study suggests that the CD36 peptide, as a TSP1 antagonist, shows promise as a novel therapeutic approach for managing obesity-related metabolic disorders.