Choline-deficient High-fat Diet Research Articles

Rifaximin prophylaxis in MASLD‑hepatocellular carcinoma: Lessons from a negative animal model.

The incidence of hepatocellular carcinoma (HCC) has been rising, particularly among individuals diagnosed with metabolic dysfunction-associated steatotic liver disease. In the present study, the prophylactic effects of rifaximin (RIF) on HCC, inflammatory markers and cardiovascular risk (CVR) were investigated in an animal model. Adult Sprague-Dawley rats were randomly allocated into three groups (n=10, each): Control [standard diet/water plus gavage with vehicle (Veh)], HCC [high-fat choline deficient diet (HFCD)/diethylnitrosamine (DEN) in drinking water/Veh gavage] and RIF [HFCD/DEN/RIF (50 mg/kg/day) gavage] groups. After euthanasia at week 16, biochemical/inflammatory markers and the liver histology were assessed. The results demonstrated that the HCC and RIF animals had a significant increase in fresh liver weight, liver weight/body weight ratio, serum total cholesterol (TC), high-density lipoprotein-cholesterol, triglycerides, hepatic lipid accumulation and hepatic concentration of triglycerides and TC, relative to the controls (P<0.001, for all). Additionally, the HCC and RIF animals had higher plasminogen activator inhibitor, intercellular adhesion molecule-1, E-selectin and CVR scores than the controls (P<0.001, for all). The HCC animals had higher interleukin (IL)-1β (P=0.011), IL-10 (P<0.001), toll-like receptor-2 (P=0.012), lipopolysaccharide-binding protein (P=0.018) and metalloproteinase-2 (P=0.003) levels than the RIF animals. Furthermore, liver steatosis, inflammation and fibrosis, along with increased collagen fiber deposition occurred in the HCC and RIF groups. However, HCC occurred only in 2 RIF rats. In conclusion, although most animals did not develop HCC in the present study, RIF positively affected liver inflammation markers involved in steatohepatitis pathogenesis.

Deciphering the mechanism of Chaihu Shugan San in the treatment of nonalcoholic steatohepatitis using network pharmacology and molecular docking.

In China, there is a long history and rich clinical experience in treating nonalcoholic steatohepatitis (NASH) with traditional Chinese herbal medicines, including Chai Hu Shu Gan San. This study aims to investigate the potential regulatory effects of Chaihu Shugan San (CSS) on liver lipid metabolism and inflammatory damage in mice with experimental nonalcoholic steatohepatitis (NASH) induced by a choline-deficient high-fat diet (CDHFD). Utilizing network pharmacology, we systematically explore the mechanisms of action and therapeutic potential of CSS against NASH. Potential targets in CSS and targets for NASH were identified using online databases. Functional enrichment and protein-protein interaction analyses were conducted to identify hub-targeted genes and elucidate the underlying molecular mechanisms. The affinities of active compounds in CSS with hub-targeted genes were evaluated using molecular docking. Finally, hub-targeted genes were validated through real-time polymerase chain reaction, western blotting, and immunofluorescence in choline-deficient high-fat diet mice, both with and without CSS treatment. CSS reduces serum ALT and AST levels in NASH mice(P < 0.05) and ameliorates ballooning degeneration in the livers of NASH mice, thereby lowering the NAS score(P < 0.05). Including naringenin, high-performance liquid chromatography/mass spectrometrys identified 12 chromatographic peaks. Based on network pharmacology analysis, CSS contains a total of 103 active compounds and 877 target genes. Transferase activity represents a potential mechanism for therapeutic intervention of CSS in NASH. The transcriptional levels and protein expression of the SIRT1 gene in NASH mice are significantly increased by CSS (P < 0.05). Naringenin is probable active compound in CSS and SIRT1 is the hub gene by which CSS is involved in NASH treatment.

Aetiology-specific inflammation patterns in patients and rat models of compensated cirrhosis

BackgroundCirrhosis is associated with a proinflammatory environment. AimsTo analyse aetiology-specific inflammation patterns in compensated cirrhosis in animal models and patients. MethodsPortal pressure (PP), fibrosis (collagen proportionate area [CPA]) and hepatic inflammation were measured in cirrhotic rat models (thioacetamide [TAA;n = 12]; choline-deficient high-fat diet [CDHFD;n = 12]; bile duct ligation [BDL;n = 16]). Compensated cirrhotic patients (alcohol-related liver disease [ALD;n = 67]; metabolic dysfunction-associated steatohepatitis [MASH;n = 50]; cholestatic liver disease [primary biliary cholangitis [PBC]/primary sclerosing cholangitis [PSC];n = 22]) undergoing hepatic venous pressure gradient (HVPG) measurement were included. ResultsIn rats, hepatic proinflammatory gene expression was highest in CDHFD and lowest in TAA, despite comparable PP levels. Across all animal models, Tnfa/Il6 correlated positively with CPA, and Mcp1 with elevated PP. Mcp1 was also associated with increased CPA in TAA/CDHFD. Mcp1/Cxcl1 showed a model-independent positive correlation to transaminases. Il1b correlated positively with CPA/PP in BDL and with transaminases in CDHFD. In patients, CRP/IL-6 were lower in MASH compared to ALD or PBC/PSC, regardless of hepatic function. IgA/IgG were highest and complement factors lowest in ALD. More pronounced systemic inflammation was linked to higher HVPG primarily in ALD/MASH. ConclusionProinflammatory pathways are upregulated across all liver disease aetiologies, yet their association with fibrosis and portal hypertension can vary.

Murine HSD17β13 does not control liver steatosis and modestly impacts fibrosis in a sex- and diet-specific manner

Human genetic studies show that loss of function mutations in 17-Beta hydroxysteroid dehydrogenase (HSD17β13) are associated with protection from non-alcoholic steatohepatitis (NASH). As a result, therapies that reduce HSD17β13 are being pursued for the treatment of NASH. However, inconsistent effects on steatosis, inflammation, and fibrosis pathogenesis have been reported in murine Hsd17b13 knockdown or knockout models. To clarify whether murine Hsd17b13 loss regulates liver damage and fibrosis, we characterized Hsd17b13 knockout mice subjected to pro-NASH diets or pro-inflammatory chemical-induced liver injury. There were no effects of Hsd17b13 loss on liver injury, inflammation, fibrosis, or lipids after 28 weeks on the Gubra-Amylin NASH (GAN) diet or 12 weeks on a 45% choline-deficient high-fat diet (CDAHFD). However, AAV-mediated re-expression of murine Hsd17b13 in KO mice increased liver macrophage abundance in both sexes fed the 45% CDAHFD. In contrast, there was a modest reduction in liver fibrosis, but not lipids or inflammation within Hsd17b13 null female, but not male, mice after 12 weeks of a 60% CDAHFD compared to WT littermates. Fibrosis and the abundance of liver macrophages were increased in Hsd17b13 KO females upon adenoviral re-expression of mouse HSD17β13, but this was not reflected in inflammatory markers. Additionally, we found minimal differences in liver injury, lipids, or inflammatory and fibrotic markers 48 h after acute CCl4 exposure. In summary, murine Hsd17b13 loss has modest diet- and sex-specific effects on liver fibrosis which contrasts with human genetic studies. This suggests a disconnect between the biological function of HSD17β13 in mice and humans.

PPARβ/δ attenuates hepatic fibrosis by reducing SMAD3 phosphorylation and p300 levels via AMPK in hepatic stellate cells

The role of peroxisome proliferator-activated receptor (PPAR)β/δ in hepatic fibrosis remains a subject of debate. Here, we examined the effects of a PPARβ/δ agonist on the pathogenesis of liver fibrosis and the activation of hepatic stellate cells (HSCs), the main effector cells in liver fibrosis, in response to the pro-fibrotic stimulus transforming growth factor-β (TGF-β). The PPARβ/δ agonist GW501516 completely prevented glucose intolerance and peripheral insulin resistance, blocked the accumulation of collagen in the liver, and attenuated the expression of inflammatory and fibrogenic genes in mice fed a choline-deficient high-fat diet (CD-HFD). The antifibrogenic effect of GW501516 observed in the livers CD-HFD-fed mice could occur through an action on HSCs since primary HSCs isolated from Ppard-/- mice showed increased mRNA levels of the profibrotic gene Col1a1. Moreover, PPARβ/δ activation abrogated TGF-β1-mediated cell migration (an indicator of cell activation) in LX-2 cells (immortalized activated human HSCs). Likewise, GW501516 attenuated the phosphorylation of the main downstream intracellular protein target of TGF-β1, suppressor of mothers against decapentaplegic (SMAD)3, as well as the levels of the SMAD3 co-activator p300 via the activation of AMP-activated protein kinase (AMPK) and the subsequent inhibition of extracellular signal-regulated kinase-1/2 (ERK1/2) in LX-2 cells. Overall, these findings uncover a new mechanism by which the activation of AMPK by a PPARβ/δ agonist reduces TGF-β1-mediated activation of HSCs and fibrosis via the reduction of both SMAD3 phosphorylation and p300 levels.

Role of Inducible Nitric Oxide Synthase (iNOS) in the Pathogenesis and Progression of Metabolic Dysfunction-Associated Steatotic Liver Disease in a Choline-Deficient High-Fat Diet Model

Role of Inducible Nitric Oxide Synthase (iNOS) in the Pathogenesis and Progression of Metabolic Dysfunction-Associated Steatotic Liver Disease in a Choline-Deficient High-Fat Diet Model

GSDME promotes MASLD by regulating pyroptosis, Drp1 citrullination-dependent mitochondrial dynamic, and energy balance in intestine and liver.

Dysregulated metabolism, cell death, and inflammation contribute to the development of metabolic dysfunction-associated steatohepatitis (MASH). Pyroptosis, a recently identified form of programmed cell death, is closely linked to inflammation. However, the precise role of pyroptosis, particularly gasdermin-E (GSDME), in MASH development remains unknown. In this study, we observed GSDME cleavage and GSDME-associated interleukin-1β (IL-1β)/IL-18 induction in liver tissues of MASH patients and MASH mouse models induced by a choline-deficient high-fat diet (CDHFD) or a high-fat/high-cholesterol diet (HFHC). Compared with wild-type mice, global GSDME knockout mice exhibited reduced liver steatosis, steatohepatitis, fibrosis, endoplasmic reticulum stress, lipotoxicity and mitochondrial dysfunction in CDHFD- or HFHC-induced MASH models. Moreover, GSDME knockout resulted in increased energy expenditure, inhibited intestinal nutrient absorption, and reduced body weight. In the mice with GSDME deficiency, reintroduction of GSDME in myeloid cells-rather than hepatocytes-mimicked the MASH pathologies and metabolic dysfunctions, as well as the changes in the formation of neutrophil extracellular traps and hepatic macrophage/monocyte subclusters. These subclusters included shifts in Tim4+ or CD163+ resident Kupffer cells, Ly6Chi pro-inflammatory monocytes, and Ly6CloCCR2loCX3CR1hi patrolling monocytes. Integrated analyses of RNA sequencing and quantitative proteomics revealed a significant GSDME-dependent reduction in citrullination at the arginine-114 (R114) site of dynamin-related protein 1 (Drp1) during MASH. Mutation of Drp1 at R114 reduced its stability, impaired its ability to redistribute to mitochondria and regulate mitophagy, and ultimately promoted its degradation under MASH stress. GSDME deficiency reversed the de-citrullination of Drp1R114, preserved Drp1 stability, and enhanced mitochondrial function. Our study highlights the role of GSDME in promoting MASH through regulating pyroptosis, Drp1 citrullination-dependent mitochondrial function, and energy balance in the intestine and liver, and suggests that GSDME may be a potential therapeutic target for managing MASH.

Targeting squalene epoxidase restores anti-PD-1 efficacy in metabolic dysfunction-associated steatohepatitis-induced hepatocellular carcinoma

ObjectiveSqualene epoxidase (SQLE) promotes metabolic dysfunction-associated steatohepatitis-associated hepatocellular carcinoma (MASH-HCC), but its role in modulating the tumour immune microenvironment in MASH-HCC remains unclear.DesignWe established hepatocyte-specific Sqle transgenic (tg) and knockout...

Carboxyl Ester Lipase Protects Against Metabolic Dysfunction-Associated Steatohepatitis by Binding to Fatty Acid Synthase

Carboxyl ester lipase (CEL), a pivotal enzyme involved in lipid metabolism, is recurrently mutated in obese mice. Here, we aimed to elucidate the functional significance, molecular mechanism, and therapeutic potential of CEL in metabolic dysfunction-associated steatohepatitis (MASH). Hepatocyte-specific Cel knockout (CelΔHEP) and wildtype (WT) littermates were fed with choline-deficient high-fat diet (CD-HFD) for 16 weeks, or methionine- and choline-deficient diet (MCD) for three weeks to induce MASH. Liquid chromatography–mass spectrometry and co-immunoprecipitation were employed to identify the downstream targets of CEL. CD-HFD/MCD-fed WT mice received intravenous injections of CEL-adeno-associated viral, serotype 8 (AAV8) to induce specific overexpression of CEL in the liver. We observed a decrease in CEL protein levels in MASH induced by CD-HFD or MCD in mice. CelΔHEP mice fed with CD-HFD or MCD exhibited pronounced hepatic steatosis, inflammation, lipid peroxidation, and liver injury compared to WT littermates, accompanied by increased hepatic nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) activation. Consistently, Cel knockdown in mouse primary hepatocytes and AML12 cells aggravated lipid accumulation and inflammation, whereas CEL overexpression exerted the opposite effect. Mechanistically, CEL directly bound to fatty acid synthase (FASN), resulting in reduced FASN SUMOylation, which in turn promoted FASN degradation through the proteasome pathway. Furthermore, inhibition of FASN ameliorated hepatocyte lipid accumulation and inflammation induced by Cel knockdown in vivo and in vitro. Hepatocyte-specific CEL overexpression using AAV8-Cel significantly mitigated steatohepatitis in mice fed with CD-HFD or MCD. CEL protects against steatohepatitis development by directly interacting with FASN and suppressing its expression for de novo lipogenesis. CEL overexpression confers a therapeutic benefit in steatohepatitis.

Extracellular Vesicles and Their Correlation with Inflammatory Factors in an Experimental Model of Steatotic Liver Disease Associated with Metabolic Dysfunction.

Background/Aims: Extracellular vesicles (EVs) are promising as a biomarker of metabolic dysfunction associated steatotic liver disease (MASLD). The objective is to study EVs and their involvement in MASLD concerning the disease's pathogenesis and progression characteristics. Methods: Male adult Sprague Dawley rats were randomly assigned into two experimental models of MASLD: MASLD-16 and MASLD-28, animals received a choline-deficient high-fat diet (CHFD) and Control-16 and Control-28, animals received a standard diet (SD) for 16 and 28 weeks, respectively. Biological samples from these animal models were used, as well as previously registered variables. EVs from hepatic tissue were characterized using confocal microscopy. EVs were isolated through differential ultracentrifugation from serum and characterized using NanoSight. The data from the EVs were correlated with biochemical, molecular, and histopathological parameters. Results: Liver EVs were identified through the flotillin-1 protein. EVs were isolated from the serum of all groups. There was a decrease of EVs concentration in MASLD-28 in comparison with Control-28 (P < 0.001) and a significant increase in EVs concentration in Control-28 compared with Control-16 (P < 0.001). There was a strong correlation between serum EVs concentration with hepatic gene expression of interleukin (Il)6 (r2 = 0.685, P < 0.05), Il1b (r2 = 0.697, P < 0.05) and tumor necrosis factor-alpha (Tnfa; r2 = 0.636, P < 0.05) in MASLD-16. Moreover, there was a strong correlation between serum EVs size and Il10 in MASLD-28 (r2 = 0.762, P < 0.05). Conclusion: The concentration and size of EVs correlated with inflammatory markers, suggesting their involvement in the systemic circulation, cellular communication, and development and progression of MASLD, demonstrating that EVs have the potential to serve as noninvasive biomarkers for MASLD diagnosis and prognosis.

Rifaximin on epigenetics and autophagy in animal model of hepatocellular carcinoma secondary to metabolic-dysfunction associated steatotic liver disease.

Prevalence of hepatocellular carcinoma (HCC) is increasing, especially in patients with metabolic dysfunction-associated steatotic liver disease (MASLD). To investigate rifaximin (RIF) effects on epigenetic/autophagy markers in animals. Adult Sprague-Dawley rats were randomly assigned (n = 8, each) and treated from 5-16 wk: Control [standard diet, water plus gavage with vehicle (Veh)], HCC [high-fat choline deficient diet (HFCD), diethylnitrosamine (DEN) in drinking water and Veh gavage], and RIF [HFCD, DEN and RIF (50 mg/kg/d) gavage]. Gene expression of epigenetic/autophagy markers and circulating miRNAs were obtained. All HCC and RIF animals developed metabolic-dysfunction associated steatohepatitis fibrosis, and cirrhosis, but three RIF-group did not develop HCC. Comparing animals who developed HCC with those who did not, miR-122, miR-34a, tubulin alpha-1c (Tuba-1c), metalloproteinases-2 (Mmp2), and metalloproteinases-9 (Mmp9) were significantly higher in the HCC-group. The opposite occurred with Becn1, coactivator associated arginine methyltransferase-1 (Carm1), enhancer of zeste homolog-2 (Ezh2), autophagy-related factor LC3A/B (Map1 Lc3b), and p62/sequestosome-1 (p62/SQSTM1)-protein. Comparing with controls, Map1 Lc3b, Becn1 and Ezh2 were lower in HCC and RIF-groups (P < 0.05). Carm1 was lower in HCC compared to RIF (P < 0.05). Hepatic expression of Mmp9 was higher in HCC in relation to the control; the opposite was observed for p62/Sqstm1 (P < 0.05). Expression of p62/SQSTM1 protein was lower in the RIF-group compared to the control (P = 0.024). There was no difference among groups for Tuba-1c, Aldolase-B, alpha-fetoprotein, and Mmp2 (P > 0.05). miR-122 was higher in HCC, and miR-34a in RIF compared to controls (P < 0.05). miR-26b was lower in HCC compared to RIF, and the inverse was observed for miR-224 (P < 0.05). There was no difference among groups regarding miR-33a, miR-143, miR-155, miR-375 and miR-21 (P > 0.05). RIF might have a possible beneficial effect on preventing/delaying liver carcinogenesis through epigenetic modulation in a rat model of MASLD-HCC.

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.

Time-restricted feeding has a limited effect on hepatic lipid accumulation, inflammation and fibrosis in a choline-deficient high-fat diet-induced murine NASH model.

Nonalcoholic steatohepatitis (NASH) occurs worldwide and is characterized by lipid accumulation in hepatocytes, hepatic inflammation, fibrosis, and an increased risk of cirrhosis. Although a major proportion of NASH patients exhibit obesity and insulin resistance, 20% lack a high body mass and are categorized as "non-obese NASH". Time-restricted feeding (TRF), limiting daily food intake within certain hours, improves obesity, lipid metabolism, and liver inflammation. Here, we determined whether TRF affects NASH pathology induced by a choline-deficient high-fat diet (CDAHFD), which does not involve obesity. TRF ameliorated the increase in epididymal white adipose tissue and plasma alanine transaminase and aspartate transaminase levels after 8 weeks of a CDAHFD. Although gene expression of TNF alpha in the liver was suppressed by TRF, it did not exhibit a suppressive effect on hepatic lipid accumulation, gene expression of cytokines and macrophage markers (Mcp1, IL1b, F4/80), or fibrosis, as evaluated by Sirius red staining and western blot analysis of alpha-smooth muscle actin. A CDAHFD-induced increase in gene expression related to fibrogenesis (Collagen 1a1 and TGFβ) was neither suppressed by TRF nor that of alpha-smooth muscle actin but was increased by TRF. Our results indicated that TRF has a limited suppressive effect on CDAHFD-induced NASH pathology.

Circulatory bone morphogenetic protein (BMP) 8B is a non-invasive predictive biomarker for the diagnosis of non-alcoholic steatohepatitis (NASH).

Nonalcoholic fatty liver disease (NAFLD) is a complex disease which is characterized by the deposition of fats in the hepatocytes. Further, it progresses to nonalcoholic steatohepatitis (NASH), fibrosis, and hepatocellular carcinoma. The increasing prevalence of NAFLD urges to find the non-invasive predictive biomarkers. In this study, we sought to determine increased BMP8B levels as predictors for the progression of NAFLD. In the present cross-sectional study, circulatory BMP8B levels were measured in healthy controls (n = 56), NAFL patients (n = 72) and NASH patients (n = 77) by using an ELISA kit. Human hepatic BMP8B mRNA expression was measured in the liver tissue of control and NASH patients. In addition, BMP8B expression was confirmed by immunohistochemistry analysis. Furthermore, hepatic BMP8B mRNA expression was measured in wild type (WT) mice, WT mice fed with choline deficient high fat diet (WT+CDHF), iNOS (inducible nitric oxide synthase) knockout (iNOS-/-) mice, iNOS-/- fed with CDHF diet (iNOS-/-+CDHF). Increased circulatory BMP8B levels and BMP8B mRNA expression in hepatic tissue were significantly higher in NASH patients as compared with the control subjects. BMP8B expression was increased parallel to the fibrosis score in the hepatic tissues of NASH patients. It was observed that increased BMP8B levels have shown a significant positive correlation between aspartate aminotransferase (r = 0.31, p = 0.005), alanine aminotransferase (r = 0.23, p = 0.045), APRI (r = 0.30, p = 0.009), and Fib-4 score (r = 0.25, p = 0.036) in NASH patients. BMP8B has maintained a significant association with NASH and shown high sensitivity (92.91%) and specificity (92.73%) in NASH patients. Furthermore, increased BMP8B mRNA expression levels were observed in iNOS-/-+CDHF mice. Our study findings confirmed that BMP8B increases with the severity of the disease and BMP8B shows potential as a non-invasive predictive biomarker to identify NAFLD progression. However, future studies should investigate circulatory BMP8B levels in a large number of patients and also its impact on liver during NAFLD progression.

Comparative profiling of gut microbiota and metabolome in diet-induced obese and insulin-resistant C57BL/6J mice

Diet-based models are commonly used to investigate obesity and related disorders. We conducted a comparative profiling of three obesogenic diets HFD, high fat diet; HFHF, high fat high fructose diet; and HFCD, high fat choline deficient diet to assess their impact on the gut microbiome and metabolome. After 20 weeks, we analyzed the gut microbiota and metabolomes of liver, plasma, cecal, and fecal samples. Fecal and plasma bile acids (BAs) and fecal short-chain fatty acids (SCFAs) were also examined. Significant changes were observed in fecal and cecal metabolites, with increased Firmicutes and decreased Bacteroidetes in the HFD, HFHF, and HFCD-fed mice compared to chow and LFD (low fat diet)-fed mice. Most BAs were reduced in plasma and fecal samples of obese groups, except taurocholic acid, which increased in HFCD mice's plasma. SCFAs like acetate and butyrate significantly decreased in obesogenic diet groups, while propionic acid specifically decreased in the HFCD group. Pathway analysis revealed significant alterations in amino acid, carbohydrate metabolism, and nucleic acid biosynthesis pathways in obese mice. Surprisingly, even LFD-fed mice showed distinct changes in microbiome and metabolite profiles compared to the chow group. This study provides insights into gut microbiome dysbiosis and metabolite alterations induced by obesogenic and LFD diets in various tissues. These findings aid in selecting suitable diet models to study the role of the gut microbiome and metabolites in obesity and associated disorders, with potential implications for understanding similar pathologies in humans.

Utility of ultrasonography in a mouse model of non-alcoholic steatohepatitis induced by a choline-deficient, high-fat diet and dextran sulfate sodium

BackgroundNonalcoholic steatohepatitis (NASH) is a chronic progressive liver disease that can progress to cirrhosis and hepatocellular carcinoma. The prevalence of NASH is increasing year by year. However, the etiology and progression of NASH, along with the processes leading to carcinogenesis, remain poorly understood. A range of animal models are used in research, but investigators have been unable to establish a model that results in tumorigenesis from a stable disease state. The present study aimed to create a stable, low-mortality model of NASH using abdominal ultrasonography (US) to assess NASH stage and diagnose liver tumors. MethodsThirty-four 19-week-old male C57BL/6J mice were fed a choline-deficient, high-fat (CDHF) diet. Twenty animals were given seven courses of 0.8 % dextran sulfate sodium (DSS) for 7 days followed by 10 days of MilliQ water (CDHF+DSS group). The remaining 14 animals drank only MilliQ water (CDHF group). All animals were weighed weekly and US was performed on Days 35 and 120. After necropsy, samples were taken for biochemical analysis and histopathological evaluation. ResultsThe CDHF+DSS group had significantly lower body weight on Days 35 and 120, and significantly higher liver/body weight (%) on Day 35 compared to the CDHF group. US on Days 35 and 120 revealed significantly shorter long intestine and higher colonic histological score in the CDHF+DSS group compared to the CDHF group. IL-1β and IL-6 levels in the large intestinal tissue were significantly higher in the CDHF+DSS group. ConclusionsA stable, low-mortality model of NASH was created with a CDHF diet and intermittent 0.8 % DSS. Abdominal US can assess the degree of fatty degeneration and evaluate liver tumorigenesis without necropsy. This assessment procedure will reduce the number of mice killed unnecessarily during experiments, thereby contributing to animal welfare.

Lactobacillus plantarum ameliorates NASH-related inflammation by upregulating l-arginine production

Lactobacillus is a probiotic with therapeutic potential for several diseases, including liver disease. However, the therapeutic effect of L. plantarum against nonalcoholic steatohepatitis (NASH) and its underlying mechanisms remain unelucidated. Therefore, we delineated the L. plantarum-mediated NASH regulation in a mouse model to understand its therapeutic effect. We used a choline-deficient high-fat diet (CD-HFD)-induced murine model that recapitulated the critical features of human metabolic syndrome and investigated the effect of L. plantarum on NASH pathogenesis using transcriptomic, metagenomic, and immunohistochemistry analyses. Validation experiments were performed using liver organoids and a murine model fed a methionine-choline-deficient (MCD) diet. L. plantarum treatment in mice significantly decreased liver inflammation and improved metabolic phenotypes, such as insulin tolerance and the hepatic lipid content, compared with those in the vehicle group. RNA-sequencing analysis revealed that L. plantarum treatment significantly downregulated inflammation-related pathways. Shotgun metagenomic analysis revealed that L-arginine biosynthesis-related microbial genes were significantly upregulated in the L. plantarum group. We also confirmed the elevated arginine levels in the serum of the L. plantarum group. We further used liver organoids and mice fed an MCD diet to demonstrate that L-arginine alone was sufficient to alleviate liver inflammation. Our data revealed a novel and counterintuitive therapeutic effect of L. plantarum on alleviating NASH-related liver inflammation by increasing circulating L-arginine.

Elafibranor upregulates the EMT-inducer S100A4 via PPARβ/δ

Elafibranor is a dual peroxisome proliferator-activated receptor (PPAR)α and β/δ agonist that has reached a phase III clinical trial for the treatment of metabolic dysfunction-associated steatotic liver disease (MASLD). Here, we examined the effects of elafibranor in mice fed a choline-deficient high-fat diet (CD-HFD), a model of metabolic dysfunction-associated steatohepatitis (MASH) that presents obesity and insulin resistance. Our findings revealed that elafibranor treatment ameliorated steatosis, inflammation, and fibrogenesis in the livers of CD-HFD-fed mice. Unexpectedly, elafibranor also increased the levels of the epithelial-mesenchymal transition (EMT)-promoting protein S100A4 via PPARβ/δ activation. The increase in S100A4 protein levels caused by elafibranor was accompanied by changes in the levels of markers associated with the EMT program. The S100A4 induction caused by elafibranor was confirmed in the BRL-3A rat liver cells and a mouse primary hepatocyte culture. Furthermore, elafibranor reduced the levels of ASB2, a protein that promotes S100A4 degradation, while ASB2 overexpression prevented the stimulating effect of elafibranor on S100A4. Collectively, these findings reveal an unexpected hepatic effect of elafibranor on increasing S100A4 and promoting the EMT program.

Lack of thyroid hormone receptor beta is not detrimental for non-alcoholic steatohepatitis progression

Agonists for thyroid hormone receptor β (TRβ) show promise in preclinical studies and clinical trials to improve non-alcoholic fatty liver disease. A recent study on human livers, however, revealed reduced TRβ expression in non-alcoholic steatohepatitis (NASH), indicating a developing thyroid hormone resistance, which could constitute a major obstacle for those agonists. Using a rapid NASH paradigm combining choline-deficient high-fat diet and thermoneutrality, we confirm that TRβ declines during disease progression in mice similar to humans. Contrary to expectations, mice lacking TRβ showed less liver fibrosis, and NASH marker genes were not elevated. Conversely, increasing TRβ expression in wild-type NASH mice using liver-targeted gene therapy did not improve histology, gene expression, or metabolic parameters, indicating that TRβ receptor levels are of minor relevance for NASH development and progression in our model, and suggest that liver-rather than isoform-specificity might be more relevant for NASH treatment with thyroid hormone receptor agonists.

Protective Effects of Gnetin C from Melinjo Seed Extract against High-Fat Diet-Induced Hepatic Steatosis and Liver Fibrosis in NAFLD Mice Model.

Nonalcoholic fatty liver disease (NAFLD), the most common form of chronic liver disease, can progress to hepatic steatosis, inflammation, and advanced fibrosis, increasing the risk of cirrhosis. Resveratrol, a natural polyphenol with antioxidant and anti-inflammatory properties, is beneficial in treating multiple metabolic diseases. Gnetin C, a resveratrol derivative obtained from Melinjo seed extract (MSE), shares similar health-promoting properties. We investigated the role of gnetin C in preventing NAFLD in a mouse model and compared it with resveratrol. Male C57BL/6J mice were fed a control diet (10% calories from fat), a high-fat choline-deficient (HFCD) diet (46% calories from fat) and HFCD diet supplemented with gnetin C (150 mg/kg BW·day-1) or resveratrol (150 mg/kg BW·day-1) for 12 weeks. Gnetin C supplementation reduced body and liver weight, and improved blood glucose levels and insulin sensitivity. Both gnetin C- and resveratrol reduced hepatic steatosis, with gnetin C also decreasing liver lipid content. Gnetin C and resveratrol ameliorated HFCD diet-induced hepatic fibrosis. The mRNA expression results, and western blot analyses showed that gnetin C and, to some extent, resveratrol downregulated fibrosis markers in the TGF-β1 signaling pathway, indicating a possible safeguarding mechanism against NAFLD. These results suggest that gnetin C supplementation may protect against lipid deposition and hepatic fibrosis.