Gene Expression In Liver Research Articles

An Integrated Profiling of Liver Metabolome and Transcriptome of Pigs Fed Diets with Different Starch Sources

Diets containing higher-amylose-content starches were proved to have some beneficial effects on monogastric animals, such as promoting the proliferation of intestinal probiotics. However, current research on the effects of diets with different starch sources on animals at the extraintestinal level is still very limited. We hypothesized that diets with different starch sources may affect lipid-related gene expression and metabolism in the liver of pigs. This study aimed to use adult pig models to evaluate the effects of diets with different starch sources (tapioca starch, TS; pea starch, PS) on the liver gene expressions and metabolism. In total, 48 growing pigs were randomly assigned to the TS and PS diets with 8 replicate pens/group and 3 pigs per pen. On day 44 of the experiment, liver samples were collected for metabolome and transcriptome analysis. Metabolome data suggested that different starch sources affected (p < 0.05) the metabolic patterns of liver. Compared with the TS diet, the PS diet increased (p < 0.05) some unsaturated fatty acids and several amino acids or peptide levels in the liver of pigs. Moreover, transcriptome data indicated the PS diets elevated (p < 0.05) fatty acid β-oxidation-related gene expression in the liver of pigs, and reduced (p < 0.05) unsaturated fatty acid metabolism-related gene expression. The results of quantitative real-time PCR confirmed that the PS diet upregulated (p < 0.05) the expression of acyl-CoA dehydrogenase very long chain (ACADVL), carnitine palmitoyl transferase (CPT) 1A, and malonyl-CoA decarboxylase (MLYCD), and downregulated (p < 0.05) the expression level of cytochrome P450 2U1 (CYP2U1) and aldehyde dehydrogenase 1B1 (ALDH1B1) in the liver. In addition, the results of a Mantel test indicated the muscle fatty acids were significantly closely correlated (p < 0.05) with liver gene expressions and metabolites. In summary, these findings suggest that diets containing higher amylose starches improved the lipid degradation and the unsaturated fatty acid levels in pig livers, and thus can generate some potential beneficial effects (such as anti-inflammatory and antioxidant) on pig health.

Maternal under-nutrition during pregnancy alters the molecular response to over-nutrition in multiple organs and tissues in nonhuman primate juvenile offspring.

Previous studies in rodents suggest that mismatch between fetal and postnatal nutrition predisposes individuals to metabolic diseases. We hypothesized that in nonhuman primates (NHP), fetal programming of maternal undernutrition (MUN) persists postnatally with a dietary mismatch altering metabolic molecular systems that precede standard clinical measures. We used unbiased molecular approaches to examine response to a high fat, high-carbohydrate diet plus sugar drink (HFCS) challenge in NHP juvenile offspring of MUN pregnancies compared with controls (CON). Pregnant baboons were fed ad libitum (CON) or 30% calorie reduction from 0.16 gestation through lactation; weaned offspring were fed chow ad libitum. MUN offspring were growth restricted at birth. Liver, omental fat, and skeletal muscle gene expression, and liver glycogen, muscle mitochondria, and fat cell size were quantified. Before challenge, MUN offspring had lower body mass index (BMI) and liver glycogen, and consumed more sugar drink than CON. After HFCS challenge, MUN and CON BMIs were similar. Molecular analyses showed HFCS response differences between CON and MUN for muscle and liver, including hepatic splicing and unfolded protein response. Altered liver signaling pathways and glycogen content between MUN and CON at baseline indicate in utero programming persists in MUN juveniles. MUN catchup growth during consumption of HFCS suggests increased risk of obesity, diabetes, and cardiovascular disease. Greater sugar drink consumption in MUN demonstrates altered appetitive drive due to programming. Differences in blood leptin, liver glycogen, and tissue-specific molecular response to HFCS suggest MUN significantly impacts juvenile offspring ability to manage an energy rich diet.

Association of antipsychotic drugs on type 2 diabetes mellitus risk in patients with schizophrenia: a population-based cohort and in vitro glucose homeostasis-related gene expression study

BackgroundType 2 diabetes mellitus (T2DM) and its related complications are associated with schizophrenia. However, the relationship between antipsychotic medications (APs) and T2DM risk remains unclear. In this population-based, retrospective cohort study across the country, we investigated schizophrenia and the effect of APs on the risk of T2DM, and glucose homeostasis-related gene expression.MethodsWe used information from the Longitudinal Health Insurance Database of Taiwan for individuals newly diagnosed with schizophrenia (N = 4,606) and a disease-free control cohort (N = 4,606). The differences in rates of development of T2DM between the two cohorts were assessed using a Cox proportional hazards regression model. The effects of APs on the expression of glucose homeostasis-related genes in liver and muscle cell lines were assessed using quantitative real-time PCR.ResultsAfter controlling potential associated confounding factors, the risk of T2DM was higher in the case group than that in the control group [adjusted hazard ratio (aHR), 1.80, p < 0.001]. Moreover, the likelihood of T2DM incidence in patients with schizophrenia without AP treatment (aHR, 2.83) was significantly higher than that in non-schizophrenia controls and those treated with APs (aHR ≤ 0.60). In an in vitro model, most APs did not affect the expression of hepatic gluconeogenesis genes but upregulated those beneficial for glucose homeostasis in muscle cells.ConclusionThis study demonstrates the impact of schizophrenia and APs and the risk of developing T2DM in Asian populations. Unmeasured confounding risk factors for T2DM may not have been included in the study. These findings may help psychiatric practitioners identify patients at risk of developing T2DM.

Synergistic Effects of Fructose and Food Preservatives on Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD): From Gut Microbiome Alterations to Hepatic Gene Expression

Background/Objectives: Metabolic dysfunction-associated steatotic liver disease (MASLD) is a growing global health problem closely linked to dietary habits, particularly high fructose consumption. This study investigates the combined effects of fructose and common food preservatives (sodium benzoate, sodium nitrite, and potassium sorbate) on the development and progression of MASLD. Methods: We utilized a human microbiota-associated mouse model, administering 10% fructose with or without preservatives for 11 weeks. Liver histology, hepatic gene expression (microarray analysis), biochemical markers, cytokine profiles, intestinal permeability, and gut microbiome composition (16S rRNA and Internal Transcribed Spacer (ITS) sequencing) were evaluated. Results: Fructose and potassium sorbate synergistically induced liver pathology characterized by increased steatosis, inflammation and fibrosis. These histological changes were associated with elevated liver function markers and altered lipid profiles. The treatments also induced significant changes in both the bacterial and fungal communities and disrupted intestinal barrier function, leading to increased pro-inflammatory responses in the mesenteric lymph nodes. Liver gene expression analysis revealed a wide range of transcriptional changes induced by fructose and modulated by the preservative. Key genes involved in lipid metabolism, oxidative stress, and inflammatory responses were affected. Conclusions: Our findings highlight the complex interactions between dietary components, gut microbiota, and host metabolism in the development of MASLD. The study identifies potential risks associated with the combined consumption of fructose and preservatives, particularly potassium sorbate. Our data reveal new mechanisms that are involved in the development of MASLD and open up a new avenue for the prevention and treatment of MASLD through dietary interventions and the modulation of the microbiome.

Sexual Dimorphism in the Immunometabolic Role of Gpr183 in Mice

Abstract Aim Excessive eating and intake of a Western diet negatively affect the intestinal immune system, resulting in compromised glucose homeostasis and lower gut bacterial diversity. The G protein-coupled receptor GPR183 regulates immune cell migration and intestinal immune response and has been associated with tuberculosis, type 1 diabetes, and inflammatory bowel diseases. We hypothesized that with these implications, GPR183 has an important immunometabolic role and investigated this using a global Gpr183 knock-out mouse model. Material and methods Wild-type (WT) and Gpr183 deficient (Gpr183-/-) mice were fed a high-fat, high-sucrose diet (HFSD) for 15 weeks. We investigated changes in weight, body composition, fecal IgA levels, fecal microbiome, and glucose tolerance before and after the diet. Macrophage infiltration into visceral fat was determined by flow cytometry, and hepatic gene expression was measured. Results and conclusions A sexual dimorphism was discovered, where female Gpr183-/- mice showed adverse metabolic outcomes compared to WT counterparts with inferior glucose tolerance, lower fecal IgA levels, and increased macrophage infiltration in visceral fat. In contrast, male Gpr183-/- mice had significantly lower fasting blood glucose after diet than male WT mice. Liver gene expression showed reduced inflammation and macrophage markers in Gpr183-/- livers, regardless of sex, while the pancreatic islet area did not differ between the groups. No conclusive differences were found after microbiome sequencing. To conclude, Gpr183 maintains metabolic homeostasis in female but not in male mice independent of diet. If confirmed in humans, future therapy targeting GPR183 should consider this sexual dimorphism.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) elicited dose-dependent shifts in the murine urinary metabolome associated with hepatic AHR-mediated differential gene expression.

Epidemiological evidence suggests an association between dioxin and dioxin-like compound (DLC) exposure and human liver disease. The prototypical DLC, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), has been shown to induce the progression of reversible hepatic steatosis to steatohepatitis with periportal fibrosis and biliary hyperplasia in mice. Although the effects of TCDD toxicity are mediated by aryl hydrocarbon receptor (AHR) activation, the underlying mechanisms of TCDD-induced hepatotoxicity are unresolved. In the present study, male C57BL/6NCrl mice were gavaged every 4 days for 28 days with 0.03 - 30 μg/kg TCDD and evaluated for liver histopathology and gene expression as well as complementary 1-dimensional proton magnetic resonance (1D- 1H NMR) urinary metabolic profiling. Urinary trimethylamine (TMA), trimethylamine N-oxide (TMAO), and 1-methylnicotinamide (1MN) levels were altered by TCDD at doses ≤ 3 μg/kg; other urinary metabolites, like glycolate, urocanate, and 3-hydroxyisovalerate, were only altered at doses that induced moderate to severe steatohepatitis. Bulk liver RNA-seq data suggested altered urinary metabolites correlated with hepatic differential gene expression corresponding to specific metabolic pathways. In addition to evaluating whether altered urinary metabolites were liver-dependent, published single-nuclear RNA-seq (snRNA-seq), AHR ChIP-seq, and AHR knockout gene expression datasets provide further support for hepatic cell-type and AHR-regulated dependency, respectively. Overall, TCDD-induced liver effects were preceded by and occurred with changes in urinary metabolite levels due to AHR-mediated changes in hepatic gene expression.

Changes in Microbial Ecosystems and Serum Metabolomics by Diet Supplementation With Enramycin in Weaning Piglets.

Antibiotics are used in swine production for growth promotion and disease prevention, raising concerns about environmental contamination and antibiotic resistance. In this study, we investigated the effects of enramycin supplementation on piglet growth, gut microbiota and blood metabolites. Enramycin promotes piglet growth and temporarily reduces diarrhoea. Gut microbiota analysis revealed changes in microbial composition, including an increase in the abundance of Limosilactobacillus reuteri. Metabolomic analysis has identified elevated levels of dimethylglycine, a known growth-promoting factor, in the enramycin group. Liver gene expression analysis revealed increased mRNA levels of ALDH and dimethylglycine dehydrogenase, which are enzymes involved in dimethylglycine metabolism. The enramycin-treated group had a higher concentration of acetic acid in caecal contents, and their caecal acetic acid concentrations were positively correlated with the abundance of L. reuteri and the content of serum dimethylglycine, respectively. These findings suggest that the promotion effect of enramycin on piglet growth is related to the gut microbiota, blood metabolites and liver gene expression, which provide insights into antibiotic alternatives for swine production.

The emergence of multidrug-resistant Proteus vulgaris infection in cage reared Pangasianodon hypophthalmus: Molecular characterization and host-pathogen response

The study investigates the causative agent responsible for massive mortality in Pangasianodon hypophthalmus cage farms. The infected pangasius were lethargic, not taking feed, and had exophthalmia, deep ulceration, and hemorrhage on the ventral body surface. Pathogens were isolated from infected pangasius tissue samples, and the strain was preliminarily identified as Proteus vulgaris based on morphology, biochemical tests, 16S rRNA PCR sequencing, and phylogenetic analysis. The microbiological analysis revealed that P. vulgaris was associated with the disease outbreak and mortality of P. hypophthalmus, as confirmed by the biofilm formation, swimming activity, and survival assay results. The isolated P. vulgaris was resistant to several antibiotics, including Doxycycline, Dicloxacillin, Polymyxin B, Chloramphenicol, and Imipenem, exhibiting multiple antibiotic-resistant phenotypes. Furthermore, a host-pathogen model was developed to investigate the in vivo effect of emerging P. vulgaris infection in striped catfish. Results showed that P. vulgaris infection exhibited varying degrees of cellular changes in the kidney, liver, and gill tissues of infected P. hypophthalmus samples. The transcription analysis further highlights that P. vulgaris modulates the antioxidants, immune activation, growth regulator, homeostasis, degradation of invading DNA, and DNA damage-related gene expression in liver, kidney, spleen, skin, and gill tissue samples of infected P. hypophthalmus. The lessons learned from the study could be critical in understanding the P. vulgaris infection patterns and pathobiology necessary to enable risk assessment and develop management measures to control the bacterium's virulence.

Lactic acid bacteria supplementation: A bioprotective approach to mitigating cadmium-induced toxicity and modulating gene expression in murine models

This study aimed to assess the effects of different strains of lactic acid bacteria, namely LeviLactobacillus brevis (AC10), Lacticaseibacillus rhamnosus (AC11), and Pediococcus acidilactici (AC15), on mice exposed to cadmium-induced oxidative stress. The study assessed weight gain, liver enzymes, antioxidant enzymes, immunoglobulin factors, lipid peroxidation, and gene expression in liver and brain of mice. The findings revealed that the AC10 and AC11 strains had a higher ability to absorb Cd as compared to AC15. The in vivo analysis demonstrated that the dietary dual supplementation of AC10 and AC11 resulted in significant (p < 0.05) improvements, including increased body weight and food intake, reduced cadmium tissue deposition, decreased lipid peroxidation, enhanced cellular antioxidant redox potential, suppressed inflammation genes in the liver and brain tissues, and improved morpho-characteristics of the jejunum in mice challenged by cadmium-induced toxicity. The multiple mechanisms of action, including heavy metal sequestration, antioxidant enhancement, and maintenance of intestinal integrity, highlight the potential of these probiotics’ intervention as a viable approach to counteract the deleterious effects of cadmium exposure.

Sexual Selection on Non-Ornamental Traits Is Underpinned by Evidence of Genetic Constraints on Sex-Biased Expression in Dusky Pipefish.

Species lacking distinct secondary sex characteristics, such as differences in size or morphology, are often thought to experience lower levels of sex-specific selection in comparison to highly sexually dimorphic organisms. However, monomorphism in classic visible traits could be a result of genetic or physiological constraints that prevent the sexes from reaching divergent fitness optima. Additionally, biochemical and molecular work have revealed a variety of less easily observed phenotypes that nonetheless exhibit profound dimorphism. Sex-specific selection could act on these more subtle, less visible, traits. We investigate sex-specific selection in the polygynandrous dusky pipefish (Syngnathus floridae), which lacks distinct secondary sexual characteristics such as size, colour and morphological dimorphism. Using experimental breeding populations, we revealed that although males and females have similar opportunities for sexual selection, only males experience significant sexual selection pressures on body size. We also investigated patterns of sex-biased and sex-specific gene expression in gonads, livers and gills, and tested whether genes with highly divergent expression patterns between the sexes are more likely to be tissue-specific, and therefore relieved of genetic constraints. Sex bias in gene expression was widespread, although the reproductive organs had the most sex-biased and sex-specific genes. Sex-specific selection on gene expression in gills was primarily related to immune response, whereas the liver and gonads had a wide variety of cellular processes, as well as reproductive proteins, showing sex-biased expression. These sex-biased genes showed higher organ-specificity in their expression patterns, suggesting that pleiotropic constraints might have historically impacted the evolution of sex-specific expression patterns. Altogether, we find evidence for ongoing and historical sex-specific selection in the dusky pipefish.

Pro-inflammatory cytokines gene expression in liver and kidneys of rats exposed to a sub-lethal dose of Bitis arietans snake venom.

Bitis arietans (Puff adder) is a poisonous snake and its bite causes pain, edema, blistering, tissue damage and neutrophilia. There are limited studies on inflammatory process involved in Bitis arietans envenomation. We therefore investigated the role of proinflammatory cytokines in Bitis arietans venom (BAV)-induced liver and kidney toxicities in rats. Adult male Sprague Dawley rats were treated with BAV (0.5 mg/kg) and were sacrificed after specific time intervals (2 h, 24 h, 1 week). Blood samples were collected for liver and renal function tests and tissues were collected for histopathology and gene expression analysis of IL-1β, IL-6, and TNF-α in liver and kidneys. There was no significant difference in serum ALT activities among different treatment groups. Serum AST was significantly increased at 24 h following BAV injection. In both organs, injection of BAV resulted in mild inflammatory cell infiltration at 2 h post-dosing which normalized after 1 week. In liver, there was a significant increase in IL-1β expression in BAV-treated rats at 2 and 24 h post-dosing that reduced after one week. Significant increases in IL-6 and TNF-α were observed at 24 h and 1 week after BAV exposure. In kidneys, there were significant increases in IL-1β and TNF-α expression at 24 h that subsided after 1 week. In conclusion, a single sub-lethal dose of BAV caused an acute phase inflammation in liver and kidneys. It is most probable that a higher dose of BAV may result in greater and irreversible damage to these organs.

6827 Pharmacological PPARα Activation In Combination With Ketogenic Nutrition Aggravated Muscle Weakness By Metabolic Failure In Septic Mice

Abstract Disclosure: C. Lauwers: None. M.P. Casaer: None. W. Vankrunkelsven: None. S. Derde: None. I. Derese: None. S. Vander Perre: None. P. Vermeersch: None. G.H. Van Den Berghe: None. L. Langouche: None. Introduction: In septic mice, infusion of ketone bodies (beta-hydroxybutyrate (BHB)) attenuated muscle weakness, a debilitating complication of critical illness. Interestingly, in critically ill children, fasting-induced ketosis also improved outcomes, but in adults ketosis upon fasting was impaired, likely due to suppression of PPARα, a key transcriptional regulator of ketogenesis. In septic mice, pharmacological induction of PPARα by pemafibrate (PF) alone, however, was ineffective in promoting ketosis. Therefore, we here hypothesized that PPARα activation by PF combined with ketogenic nutrition can more effectively induce ketosis and hereby reduce muscle weakness in sepsis. Methods: In a fluid-resuscitated and antibiotic-treated mouse model of prolonged (5 days) sepsis (male C57BL/6J), the impact of PF (1mg/kg/d) combined with 4 types of parenteral nutrition (PN) was studied. Mice were either allocated to PF + total PN (composed of glucose, long-chain triglycerides (LCTs) and amino acids) (TPN, n = 18), PF + TPN with an extra LCT emulsion (TPN + LCTs, n = 18), PF + a pure low dose LCT emulsion (Low LCT, n = 16) or PF + a pure high dose LCT emulsion (High LCT n = 18). Healthy control mice on standard chow served as a reference (HC, n=19). After 5 days of sepsis, ex vivo muscle force (aurora scientific®), plasma BHB and lipids (TG, FFA, LDL- and HDL-cholesterol; commercial assays), and liver gene expression levels were measured. Metabolomics of muscle tissue was assessed by LC-MS and plasma acylcarnitines by LC-MS-MS. Results: Liver PPARα gene expression was higher in all PF-treated mice than in HCs. Compared to HCs, specific muscle force was reduced in all septic mice, but mostly so in both PF + LCT groups (PF + Low LCT: 10.7%, PF + High LCT: 25.0%, PF+TPN + LCTs: 44.6%, PF+TPN: 58.4% of HC: 124.7 mN/mm²; p = 0.0001). PF + TPN + LCTs did not induce ketosis, whereas BHB plasma levels increased 95-fold in the PF + High LCT and 10-fold in the PF + Low LCT group (p &amp;lt; 0.0001 vs. other groups). Glycemia was lower in both PF + LCT groups relative to the other septic mice (PF + Low LCT: 52 mg/dl; PF + High LCT: 80 mg/dl; PF + TPN + LCTs: 108 mg/dl; PF + TPN: 102 mg/dl; p &amp;lt; 0.0001). Compared to the PF + TPN group, plasma lipids and long-chain acylcarnitines were increased in all other septic mice with the highest levels in the PF + High LCT group. Muscular glycolytic intermediates and ATP levels were depleted in both PF + LCT groups in comparison with all other septic mice and HCs. Conclusion: In septic mice, PF-induced PPARα activation combined with TPN, irrespective of the amount of LCTs, was unable to induce ketosis and did not attenuate muscle weakness. By contrast, PF-induced PPARα activation in combination with pure LCTs resulted in ketosis, but aggravated rather than improved muscle weakness, irrespective of the dose. In these groups, metabolic analyses suggested a bioenergetic failure of muscle fibers with an accumulation of plasma lipids. Presentation: 6/1/2024

Inflammatory Gene Expression in Livers Undergoing Ex Situ Normothermic Perfusion Is Attenuated by Leukocyte Removal From the Perfusate.

Ex situ normothermic perfusion (ESNP) is a method to evaluate and potentially recondition organs before transplantation. However, increased expression of inflammatory molecules, including by tissue-resident immune cells, may occur during the perfusion process, potentially negating the beneficial effects of perfusion. We used RNA sequencing to assess gene expression in 31 livers undergoing ESNP, including 23 donated after circulatory death (DCD) and 8 donated after brain death. In 7 DCD livers, a leucocyte filter was added to the circuit during perfusion. Biopsies were available for transcriptomic assessment in all cases at the start of perfusion and at varying time points postperfusion. During ESNP in DCD livers, we observed an increase in proinflammatory, profibrinolytic, and prorepair pathway genes. SERPINE1, encoding plasminogen activator inhibitor-1, was among the genes most significantly upregulated during perfusion in DCD livers, potentially promoting fibrin clot persistence in vasculature. We also found increased expression of monocyte and neutrophil recruiting chemokine and proinflammatory cytokine transcripts during ESNP, but several prorepair molecules, including thymic stromal lymphopoietin, were also upregulated. In both DCD and donation after brain death livers, interferon-gamma response genes were enriched, whereas oxidative phosphorylation genes decreased in organs with high perfusate alanine transaminase, a biomarker associated with adverse clinical outcomes. The inclusion of a leukocyte filter in the perfusion circuit mitigated the induction of inflammation/immune pathway genes during perfusion and was associated with enrichment in oxidative phosphorylation genes. Leukocyte removal during ESNP abrogates transcriptional changes that are associated with unfavorable clinical outcomes, potentially benefiting human livers undergoing ESNP.

Elongation factor 1A1 inhibition elicits changes in lipid droplet size, the bulk transcriptome, and cell type-associated gene expression in MASLD mouse liver.

Eukaryotic elongation factor 1A1 (EEF1A1), originally identified for its role in protein synthesis, has additional functions in diverse cellular processes. Of note, we previously discovered a role for EEF1A1 in hepatocyte lipotoxicity. We also demonstrated that a 2-wk intervention with the EEF1A1 inhibitor didemnin B (DB) (50 µg/kg) decreased liver steatosis in a mouse model of obesity and metabolic dysfunction-associated steatotic liver disease (MASLD) [129S6/SvEvTac mice fed Western diet (42% fat) for 26 wk]. Here, we further characterized the hepatic changes occurring in these mice by assessing lipid droplet (LD) size, bulk differential expression, and cell type-associated alterations in gene expression. Consistent with the previously demonstrated decrease in hepatic steatosis, we observed decreased median LD size in response to DB. Bulk RNA sequencing (RNA-Seq) followed by gene set enrichment analysis revealed alterations in pathways related to energy metabolism and proteostasis in DB-treated mouse livers. Deconvolution of bulk data identified decreased cell type association scores for cholangiocytes, mononuclear phagocytes, and mesenchymal cells in response to DB. Overrepresentation analyses of bulk data using cell type marker gene sets further identified hepatocytes and cholangiocytes as the primary contributors to bulk differential expression in response to DB. Thus, we show that chemical inhibition of EEF1A1 decreases hepatic LD size and decreases gene expression signatures associated with several liver cell types implicated in MASLD progression. Furthermore, changes in hepatic gene expression were primarily attributable to hepatocytes and cholangiocytes. This work demonstrates that EEF1A1 inhibition may be a viable strategy to target aspects of liver biology implicated in MASLD progression.NEW & NOTEWORTHY Chemical inhibition of EEF1A1 decreases hepatic lipid droplet size and decreases gene expression signatures associated with liver cell types that contribute to MASLD progression. Furthermore, changes in hepatic gene expression are primarily attributable to hepatocytes and cholangiocytes. This work highlights the therapeutic potential of targeting EEF1A1 in the setting of MASLD, and the utility of RNA-Seq deconvolution to reveal valuable information about tissue cell type composition and cell type-associated gene expression from bulk RNA-Seq data.

Metabolic dysfunction-associated steatohepatitis reduces interferon and macrophage liver gene signatures in patients with chronic hepatitis B

Background & AimsChronic HBV patients with concomitant metabolic dysfunction-associated steatohepatitis (MASH) have been shown to develop more advanced fibrosis faster with more severe liver disease as compared to patients with chronic HBV alone. However, our understanding of the underlying mechanisms is limited. Here we study how MASH co-morbidity impact immune activity in the liver of patients with chronic HBV infection. MethodsBulk RNA sequencing was performed on liver biopsies from patients with only MASH (n=10), only HBeAg-negative chronic HBV (ENEG; n=11), combined MASH/ENEG (n=9) and healthy controls (n=9). Biopsies with no or minimal fibrosis (≤F2) were selected to avoid confounding effects of fibrosis. We compared whole transcriptome data from patients with MASH/ENEG to those with ENEG alone to determine the impact of MASH co-morbidity on chronic hepatitis B. ResultsThere is a high degree of overlap of liver gene expression profiles in patients with only ENEG versus those with only MASH compared to healthy controls, suggesting a largely shared mechanism of liver dysfunction and immune activity for these distinct conditions. In patients with ENEG, MASH co-morbidity significantly reduced interferon pathway activity (NES=2.03, p.adj=0.0251), the expression of ISGs (e.g., IFIT2, IFI27, IFITM1, IFI6), and macrophage gene signatures (e.g., MARCO, CD163, CD5L, CD63), when compared to patients with ENEG alone. ConclusionsTranscriptomic profiling of the liver suggests that MASH negatively impacts ISGs expression in the liver of patients with ENEG, which may affect antiviral immune pathways, viral replication and inflammatory responses resulting in an increased risk of advanced fibrosis in patients with chronic hepatitis B. Our study provides valuable insights for guiding future research aimed at developing effective, tailored strategies for managing patients with both conditions. Impact and implicationsIn recent decades, obesity and associated health issues have reached epidemic levels, with steatotic liver disease affecting up to 30% of adults in developed countries, and this trend is also observed among chronic hepatitis B patients. Given the high and rising prevalence of steatotic liver disease and its frequent co-occurrence in chronic hepatitis B patients, it is essential to understand how conditions such as metabolic dysfunction-associated steatohepatitis (MASH) impact immune responses in the liver. This study provides unique insights into the impact of MASH on HBV antiviral immune activity in the liver of patients with chronic hepatitis B. The rising number of patients with both conditions affects treatment outcomes and highlights the urgent need for novel, tailored therapeutic strategies. Our study holds significant relevance for guiding future research on developing treatment strategies for patients with both MASH and chronic hepatitis B.

LDT409 (pan-PPAR partial agonist) mitigates metabolic dysfunction-associated steatotic liver disease in high-fructose-fed mice

AimThis study sought to evaluate the effects of LDT409, a pan-PPAR partial agonist obtained from the main industrial waste from cashew nut processing, on hepatic remodeling, highlighting energy metabolism and endoplasmic reticulum (ER) stress in high-fructose-fed mice. MethodsMale C57BL/6 mice received a control diet (C) or a high-fructose diet (HFRU) for ten weeks. Then, a five-week treatment started: C, C-LDT409, HFRU, and HFRU-LDT409. The LDT409 (40 mg/kg of body weight) was mixed with the diets. ResultsThe HFRU diet caused insulin resistance and endoplasmic reticulum (ER) stress. High Pparg and decreased Ppara expression increased steatosis and pro-fibrogenic gene expression in livers of HFRU-fed mice. Suppressed lipogenic factors, orchestrated by PPAR-gamma, and mitigated ER stress concomitant with the increase in beta-oxidation driven by PPAR-alpha mediated the LDT409 beneficial effects. ConclusionsLDT409 may represent a potential low-cost approach to treat metabolic dysfunction-associated steatotic liver disease, which does not currently have a specific treatment.

Astaxanthin attenuates glucose-induced liver injury in largemouth bass: role of p38MAPK and PI3K/Akt signaling pathways

BackgroundAstaxanthin (ASX) has been documented to exert beneficial influence on various processes in fish. Largemouth bass (Micropterus salmoides) serves as a common model for studying glucose-induced liver disease, making it imperative to investigate the regulatory mechanisms underlying its liver health.MethodsLargemouth bass were fed with a control diet (CON), a high carbohydrate diet (HC), or a HC diet supplemented astaxanthin (HCA) for 8-weeks, followed by the glucose tolerance test (GTT). Primary hepatocytes were treated with low glucose and high glucose combined with different concentrations of astaxanthin for 48 h. The histopathology, enzymology, transcriptomics, molecular biology and cell biology were combined to investigate the mechanism of liver injury.ResultsThis study provides evidence for the protective effects of ASX against growth performance reduction and hepatic liver injure in largemouth bass fed HC diet. In GTT, HCA diet exhibited an improvement in glucose tolerance following glucose loading. Although HCA diet did not restore the expression of insulin resistance-related genes in livers at different time during the GTT, the addition of ASX in the long-term HC diet did improve the insulin resistance pathway by regulating the PTP1B/PI3K/Akt signaling pathway. Hepatic transcriptome analyses showed that ASX plays an essential role in the modulation of glucose homeostasis in response to treated with HC diet. In in vitro study, ASX treatment resulted in an exaltation in cell viability and a reduction in the rate of cell apoptosis and reactive oxygen species (ROS). Additionally, astaxanthin was observed to improve apoptosis induced by high-glucose via p38MAPK/bcl-2/caspase-3 signaling pathway.ConclusionsAstaxanthin exhibited a protective effect against apoptosis by regulating p38MAPK/bcl-2/caspase-3 pathway, and ameliorated insulin resistance by activating the PTP1B/PI3K/Akt pathway. This study elucidated the mechanism of astaxanthin in the liver injury of largemouth bass from a new perspective and provided a new target for the treatment of insulin resistance.Graphical

PSVII-13 Influence of early maternal gestational body weight gain on liver gene expression across generations in offspring

Abstract Maternal nutrition in the periconceptional period influences gene regulation in the fetal liver across generations, affecting long-term metabolism. This study aimed to examine the effects of the rate of body weight (BW) gain of the dam (F0) during early gestation on the differential gene expression of the liver of first (F1) and second-generation (F2) offspring. Crossbred Angus heifers (F0) were assigned into two groups based on their targeted rate of BW gain during the first 84 d of gestation: low gain (LG; 0.28 kg/d; n = 8) or moderate gain (MG; 0.79 kg/d; n = 8). Following this period, all heifers (F0) were kept on a forage-based diet until the F1 offspring were weaned at 8 mo. The F1 heifers underwent estrus synchronization and were artificially inseminated at 15 mo of age. Liver samples were obtained from the F1 heifers at birth and later when harvested at 84 d of gestation, along with liver samples from their F2 fetuses, for a comprehensive multigenerational RNA-Seq analysis. Differentially expressed genes (DEGs) were identified using the DESeq2 R-package, focusing on significant genes determined by a P-value ≤ 0.05 and a log2 fold change |0.5|. Metabolic pathways and biological processes were analyzed using the WebGestalt tool to understand the implications of the observed gene expression changes. At birth, F1 heifers from MG dams exhibited 281 DEGs, comprising 152 downregulated and 129 upregulated genes compared with the offspring of LG dams. These genes were over-represented in lipid metabolism, cellular homeostasis, and signaling pathways, such as MAPK and chemokine signaling. At harvest, 159 DEGs were identified in F1 heifers, with 67 genes downregulated and 92 genes upregulated in the MG group. These genes were related to cellular morphogenesis and biogenesis processes, with a notable downregulation of metabolic pathways. For the F2 fetuses, 192 DEGs were identified, where 71 genes were downregulated, and 121 genes were upregulated. These genes were involved in biological functions such as peptide secretion to cell proliferation and signaling pathways, including PI3K-Akt and Hippo signaling. The analysis of DEGs shared between F1 heifers and F2 fetuses highlighted the influence of the moderate BW weight gain of the F0 dams. At birth and harvest, F1 heifers shared three genes (NAV2, FAM131C, SH3D21). F1 heifers at birth and F2 fetuses shared five genes (CD3E, H1-12, SLC7A11, PIP4P2, ENSBTAG00000051730). From the harvest at d 84 in F1 heifers and F2 fetuses, five genes were shared (DCDC2, RIN1, ENSBTAG00000008911, ENSBTAG00000040518, ENSBTAG00000048049). No DEGs were shared across all comparisons. These findings emphasize the multigenerational impact of early gestational BW gain of the dam on liver gene expression, influencing metabolic pathways and signaling across generations.

Liver Characterization of a Cohort of Alpha-1 Antitrypsin Deficiency Patients with and without Lung Disease.

Alpha-1 antitrypsin deficiency (AATD) is a genetic disorder characterized by the misfolding and accumulation of the mutant variant of alpha-1 antitrypsin (AAT) within hepatocytes, which limits its access to the circulation and exposes the lungs to protease-mediated tissue damage. This results in progressive liver disease secondary to AAT polymerization and accumulation, and chronic obstructive pulmonary disease (COPD) due to deficient levels of AAT within the lungs. Our goal was to characterize the unique effects of COPD secondary to AATD on liver disease and gene expression. A subcohort of AATD individuals with COPD (n = 33) and AATD individuals without COPD (n = 14) were evaluated in this study from our previously reported cross-sectional cohort. We used immunohistochemistry to assess the AATD liver phenotype, and RNA sequencing to explore liver transcriptomics. We observed a distinct transcriptomic profile in liver tissues from AATD individuals with COPD compared to those without. A total of 339 genes were differentially expressed. Canonical pathways related to fibrosis, extracellular matrix remodeling, collagen deposition, hepatocellular damage, and inflammation were significantly upregulated in the livers of AATD individuals with COPD. Histopathological analysis also revealed higher levels of fibrosis and hepatocellular damage in these individuals. Our data supports a relationship between the development of COPD and liver disease in AATD and introduces genes and pathways that may play a role in AATD liver disease when COPD is present. We believe addressing lung impairment and airway inflammation may be an approach to managing AATD-related liver disease.

PSVII-19 Effects of silage particle size on beef quality and muscle lipogenesis of finishing Nellore heifers

Abstract The objective of this study was to evaluate the effect of corn silage particle size on beef quality and expression of gluconeogenic and lipogenic genes in feedlot-finished Nellore heifers. Nellore heifers (n = 94), with an initial body weight (BW) of 249.71 ± 34.62, were allotted into 32 pens (three animals per pen) in a completely randomized design, with 2 treatments and 16 repetitions. The treatments were corn silage with a particle size of 13 mm (short) or 24 mm (long). The feeding period lasted 101 d, with the first 15 d for diet adaptation. After slaughter, samples of the longissimus thoracis muscle (LT) from the left side of the half carcass and liver were taken for beef quality and gene expression analyses. The chemical composition of the beef was analyzed using near infrared according to the AOAC method 2007-04, using the FoodScanTM equipment (AOAC method: 2007-04; FOSS, Hillerod, Denmark). RT-qPCR analyses of each gene investigated were carried out using cDNA from 16 biological replicates per treatment (1 heifer chosen randomly in each pen), with each biological replicate subjected to 2 technical replicates. Relative gene expression analyses were calculated using the delta delta ct method and the reference genes used were ACTB and GAPDH. The normality of all experimental data was checked using the Shapiro-Wilk test in SAS software. When the data did not present a normal distribution, transformation was performed using PROC RANK. The model included particle size as a fixed effect and pen as a random effect. There was no treatment effect on collagen, moisture, and mineral content (P &amp;gt; 0.10), but muscles from heifers fed short particle sizes tended to have greater protein content (23.3 versus 22.9; P = 0.098), while muscles from heifers fed with long particles had greater intramuscular fat content (2.62 versus 3.28; P = 0.05). For liver gene expression, heifers fed short particle sizes tended to have greater expression of the PC gene (1.00 versus 0.82; P = 0.06), while PEPCK2 had higher expression in heifers fed long particles (1.00 versus 1.18; P = 0.04). In addition, the long particle size of corn silage affected the expression of PPARA (P = 0.001), and there was no effect of diets (P &amp;gt; 0.05) on PPARG and SREBF1 expressions (Table 1). Expression of LPL, FABP4, SCD1, CPT2 (P &amp;lt; 0.001), and ACACA (P = 0.017) genes increased in the muscle of heifers fed long particle size. Therefore, it is concluded that the use of corn silage with long particle size in feedlot diets has the potential to increase the expression of genes involved in lipogenesis and then increase intramuscular fat in Nellore heifers.