Hepatic Stress Research Articles

Hepatotoxic effects of environmentally relevant concentrations of polystyrene microplastics on senescent Zebrafish (Danio rerio): Patterns of stress response and metabolomic alterations.

The hepatotoxicity of microplastics (MPs) has garnered increasing attention, but their effects on elderly organisms remain inadequately characterized, particularly concerning hepatic stress response patterns in environmental conditions. In this study, a 10-day exposure period of elderly zebrafish to polystyrene microplastics (PS-MPs, 1 µm) was conducted, with exposure concentrations set at 5.6 × 10-7 µg/L, 5.6 × 10-4 µg/L, and 5.6 × 10-1 µg/L. PS-MPs-induced toxicity varied with concentration: superoxide dismutase (SOD), complement 3 (C3), and complement 4 (C4) initially decreased before rising; 8‑hydroxy-2-deoxyguanosine (8-OhdG), interleukin-6 (IL-6), and interleukin-8 (IL-8) increased at high concentrations. Additionally, catalase (CAT) activity and thiobarbituric acid reactive substances (TBARS) contents rose with concentration. The aged zebrafish liver exhibited differentiation driven by responsiveness; low levels cause homeostatic disruption, and high levels induce genotoxicity and immune activation. LC-MS identified twelve crucial metabolites involved in 18 metabolic pathways, including amino acids (L-tyrosine, l-arginine), lipids (phospholipids, 12(S)-leukotriene B4 and triglycerides), and N-acetylneuraminic acid, related to energy, immunity, and neurological health. Overall, elderly zebrafish exhibited clear dose-dependent thresholds and distinct physiological stress responses under varying concentrations of PS-MPs. These findings reveal how PS-MP exposure can affect physiological health and metabolism, offering critical insights into the ecological risks faced by aging organisms.

Effects of fructo-oligosaccharides and Bacillus licheniformis on performance, nutrient digestibility, hematological properties, and organ development in weaned piglets

Context Weaning is a critical period for piglets, often associated with reduced growth performance and increased susceptibility to diseases. Dietary supplements such as fructo-oligosaccharides (FOS) and Bacillus licheniformis (BL) may improve piglet health and performance during this transition. Aims To investigate the effects of dietary FOS and BL supplementation, individually and in combination, on growth performance, health status, nutrient digestibility, hematological parameters, and organ development in weaned piglets. Methods In total, 240 weaned piglets were allocated into the following six treatments: control, 0.2% FOS, 0.4% FOS, BL, 0.2% FOS + BL, and 0.4% FOS + BL. Growth performance, morbidity rates, nutrient digestibility, blood parameters, and organ indices were evaluated over the experimental period. Key results The 0.4% FOS + BL group showed significant improvements in feed conversion ratio, reduced morbidity rates, enhanced nutrient digestibility (crude protein, crude fiber, and phosphorus), increased total protein, albumin, and albumin:globulin ratio, reduced blood urea nitrogen, improved white blood cell and lymphocyte counts, and enhanced spleen and pancreatic organ indices. BL supplementation distinctively influenced liver-enzyme profiles, suggesting metabolic adaptation rather than hepatic stress. Blood urea nitrogen was reduced in BL and 0.4% FOS + BL groups. Conclusions Dietary supplementation with 0.4% FOS and BL synergistically benefited weaned piglets by improving growth performance, enhancing feed efficiency, and reducing morbidity rates. This treatment also enhanced nutrient utilization, positively affected blood parameters, and promotes the development of spleen and pancreatic organs. Implications The combination of 0.4% FOS and BL shows potential as an effective feed-additive strategy to enhance growth and immune responses in weaned piglets, potentially reducing the need for antibiotics and promoting sustainable pig production.

An 8-Week Very Low-Calorie Ketogenic Diet (VLCKD) Alters the Landscape of Obese-Derived Small Extracellular Vesicles (sEVs), Redefining Hepatic Cell Phenotypes.

Background. Very low-calorie ketogenic diets (VLCKD) are an effective weight-loss strategy for obese individuals, reducing risks of liver conditions such as non-alcoholic steatohepatitis and fibrosis. Small extracellular vesicles (sEVs) are implicated in liver fibrosis by influencing hepatic cell phenotypes and contributing to liver damage. This study investigates sEVs derived from serum of 60 obese adults categorized into low fibrosis risk (LR) and intermediate/high fibrosis risk (IHR) groups based on FibroScan elastography (FIB E scores, limit value 8 kPa) and all participants underwent an 8-week VLCKD intervention. Methods. The study examines the impact of these sEVs on fibrosis markers, inflammation, and autophagy in a hepatocyte cell line (HEPA-RG) using bioinformatics, RNA sequencing, lipidomics, RT-PCR, and Western blotting before (T0) and after (T1) VLCKD. Results. sEVs from LR patients post-VLCKD reduced fibrosis related gene expression (e.g., ACTA2) and enhanced proteins associated with regeneration and inflammation (e.g., HDAC6). Conversely, sEVs from IHR patients increased fibrosis and inflammation related gene expression (PIK3CB, AKT1, ACTA2) in hepatocytes, raising concerns about VLCKD suitability for IHR patients. IHR sEVs also decreased expression of HDAC10, HDAC6, HDAC3, MMP19, and MMP2, while increasing modulation of p-AKT, α-SMA, and VIM. Conclusion. These findings underscore the critical role of sEVs in regulating inflammation, remodeling, and hepatic stress responses, particularly in IHR patients, and suggest sEVs could complement instrumental evaluations like FibroScan in fibrosis assessment.

Gentamicin Induced Damage in Nephrotoxicity and Hepatotoxicity in Male Rabbits: The Protective Effect of Cinnamon

One common aminoglycoside antibiotic that is well-known for its ability to treat gram-negative bacterial infections is gentamicin. Its nephrotoxic and hepatotoxic side effects, which are mostly brought about by the production of free radicals that harm kidney and liver cells, frequently restrict its therapeutic application. On the other hand, strong antioxidants found in cinnamon, a popular spice and therapeutic plant, have been demonstrated to have protective properties against oxidative stress. In order to assess the protective role of cinnamon, the current study examines how cinnamon affects gentamicin-induced changes in biochemical markers, liver enzymes in male rabbits. Treatment groups included a control group, a gentamicin-only (GIN) group, a cinnamon-only (CIN) group, and a combined cinnamon-gentamicin (CIN+GIN) group. The results showed that GIN group elevated liver enzymes, specifically aspartate transaminase (AST) and alanine transaminase (ALT), suggesting possible hepatotoxicity. The dose of cinnamon decreased these enzyme levels, while the combination therapy kept the AST levels close to control. Biochemical examination revealed that cinnamon reduced these alterations, particularly in the combination therapy group, while gentamicin increased total protein, urea, and creatinine levels, indicating renal and hepatic stress. The study concludes by highlighting the potential of cinnamon in reducing gentamicin-induced toxicity, specifically through its effects on lipid profiles, liver enzyme activities, body weight, blood profiles, and biochemical markers. This suggests that cinnamon could be used as an adjuvant therapy to reduce the negative effects of gentamicin".

Treating metabolic dysfunction-associated steatohepatitis: The fat-trimming FGF21 approach.

Metabolic dysfunction-associated steatohepatitis (MASH) is a condition characterized by hepatosteatosis, inflammation, and tissue damage, with steatosis as the initial stage, which involves chronic, excess deposition of lipids in hepatic lipid droplets. Despite the growing prevalence and serious risks it poses, including liver decompensation, the need for transplantation, and increased patient mortality, MASH currently faces no approved pharmacotherapy. Several promising treatment candidates have emerged from recent clinical trials, including analogs of FGF21 and agonists of the associated FGFR1-KLB complex. These agents were well-tolerated in trials and have demonstrated significant improvements in both histological and biochemical markers of liver fat content, inflammation, injury, and fibrosis in patients with MASH. Endocrine FGF21 plays a vital role in maintaining homeostasis of lipid, glucose, and energy metabolism. It achieves this through pathways that target lipids or lipid droplets in adipocytes and hepatocytes. Mechanistically, pharmacological FGF21 acts as a potent catabolic factor to promote lipid or lipid droplet lipolysis, fatty acid oxidation, mitochondrial catabolic flux, and heat-dissipating energy expenditure, leading to effective clearance of hepatic and systemic gluco-lipotoxicity and inflammatory stress, thereby preventing obesity, diabetes, and MASH pathologies. In this review, we aim to provide an update on the outcomes of clinical trials for several FGF21 mimetics. We compare these outcomes with preclinical studies and offer a lipid-centric perspective on the mechanisms underlying the clinical benefits of these agents for MASH.

Hepatic Transcriptomics of Broilers with Low and High Feed Conversion in Response to Caloric Restriction.

In broiler chickens, the efficient utilization of macro- and micronutrients is influenced by various metabolic pathways that are closely linked to feed efficiency (FE), a critical metric in poultry industry, with residual feed intake (RFI) as the preferred proxy. Feed restriction is considered an approach to address the underlying molecular mechanisms of feed conversion. We hypothesized that broiler chickens with divergent RFI subjected to quantitative feed restriction differ in their pattern of molecular pathways for efficient nutrient utilization in liver as post-absorptive tissue. Cobb 500FF broiler chickens divergent for RFI (n = 112) were feed-restricted from day 9 until market weight at day 33-37 post-hatch. Based on a previous trial, feed restriction levels were set at 92% (low-RFI birds) and 80% (high-RFI birds) relative to the control groups. Transcriptomic analyses of the liver were conducted. Due to the interaction of the RFI group and feeding regimen, a total of 140 to 507 differentially expressed genes were identified for the respective contrasts, with implications for hepatic metabolism and cellular stress response. Although the broilers did not realize their full growth potential under restrictive feeding (12.4% reduced body weight vs. controls, p = 0.094), the gene expression patterns indicate a lower susceptibility to blood coagulation (KNG1, FGG, and FGB), suggesting that controlled and mild feed restriction could lead to health benefits in less feed-efficient broilers. Moreover, FE traits are shown to be linked to cellular detoxification processes (MGST3 and CYP2AC2) and triacylglycerol syntheses (MOGAT1 and LPIN1). Divergent transcriptional profiles between broiler groups under varied caloric conditions indicate potential for optimizing nutritional management strategies.

Persistent effects of di-n-butyl phthalate on liver transcriptome: Impaired energy and lipid metabolic pathways

The environmental contaminant dibutyl phthalate (DBP) is reported to be hepatotoxic, but the underlying molecular pathways and pathological processes remain unclear. Here we used RNA-sequencing to characterize persistent hepatic transcriptional effects one week after the conclusion of five weeks oral exposure to 10 mg/kg/day or 100 mg/kg/day DBP in adult male mice. The exploratory transcriptome analysis demonstrated five differentially expressed genes (DEGs) in the 10 mg/kg/day group and 13 in the 100 mg/kg/day group. Gene Set Enrichment Analysis (GSEA), which identifies affected biological pathways rather than focusing solely on individual genes, revealed nine significantly enriched Reactome pathways shared by both DBP treatment groups. Additionally, we found 54 upregulated and one downregulated Reactome pathways in the 10 mg/kg/day DBP group, and 29 upregulated and 13 downregulated pathways in the 100 mg/kg/day DBP group. DBP exposure disrupted several key biological processes, including protein translation, protein folding, apoptosis, Hedgehog signaling, degradation of extracellular matrix and alterations in the energy/lipid metabolism. Subsequent liver tissue analysis confirmed that DBP exposure induced tissue disorganization, oxidative stress, lipid accumulation, increased TNF-α, ATP and glucokinase levels, and affected key metabolic proteins, predominantly in a dose-response manner. Overall, the results show that DBP can cause hepatic stress and damage and suggest a potential role for DBP in the development of non-alcoholic fatty liver disease, the most prevalent liver disease worldwide.

The Impact of Silver Nanoparticles Functionalized with Spirulina Protein Extract on Rats.

Background/Objectives: This study investigates the biocompatibility and physiological impacts of silver nanoparticles (AgNPs) functionalized with Spirulina protein extract (SPE) on laboratory rats. The objective was to assess and compare the systemic distribution, organ accumulation, and changes in hematological and biochemical parameters between biofunctionalized and non-functionalized silver nanoparticles. Methods: AgNPs were functionalized with SPE. Adult Wistar rats were administered these nanoparticles to assess their distribution across various organs using ICP-MS analysis. Hematological and biochemical markers were measured to evaluate systemic effects. Results: Functionalized silver nanoparticles demonstrated preferential accumulation in the brain, liver, and testicles, with significant clearance observed post-administration. The persistence of AgNPs SPE in reproductive organs was established. Hematological analysis revealed moderate changes, suggesting mild immune activation. Biochemical tests indicated transient increases in liver enzymes, signaling reversible hepatic stress. Conclusions: The biofunctionalization of AgNPs with Spirulina protein extract modifies the nanoparticles' systemic behavior and organ distribution, enhancing their biocompatibility while inducing minimal physiological stress. These findings support the potential of Spirulina-based coatings to mitigate the toxicity and enhance the therapeutic efficacy of nanomedical agents.

Pediatric Neem powder poisoning: a report of two cases and a review of toxicity mechanisms

Neem (Azadirachta indica) is a plant known for its wide array of therapeutic properties, derived from its diverse phytochemical makeup. Despite its medicinal benefits, neem can pose significant toxicity risks, especially in children. This report presents two pediatric cases of neem powder poisoning. The first case involves a two-year-old boy who ingested neem powder with milk, resulting in seizures and fatal cardiac arrest. The second case describes a six-year-old boy who experienced vomiting after consuming neem powder with milk. Prompt medical intervention, including gastric lavage and supportive care, led to his stabilization and discharge. Neem’s toxicity is attributed to compounds like azadirachtin, which disrupt mitochondrial function, leading to symptoms such as seizures, vomiting, and hepatic stress. These cases highlight the importance of recognizing the potential dangers of neem and underscore the need for public health education and regulatory oversight to prevent such adverse outcomes in pediatric populations.

GCN2 drives diurnal patterns in the hepatic integrated stress response and maintains circadian rhythms in whole body metabolism during amino acid insufficiency.

Disruptions in circadian rhythms are associated with an increased risk of developing metabolic diseases. General control nonderepressible 2 (GCN2), a primary sensor of amino acid insufficiency and activator of the integrated stress response (ISR), has emerged as a conserved regulator of the circadian clock in multiple organisms. The objective of this study was to examine diurnal patterns in hepatic ISR activation in the liver and whole body rhythms in metabolism. We hypothesized that GCN2 activation cues hepatic ISR signaling over a natural 24-h feeding-fasting cycle. To address our objective, wild-type (WT) and whole body Gcn2 knockout (GCN2 KO) mice were housed in metabolic cages and provided free access to either a control or leucine-devoid diet (LeuD) for 8 days in total darkness. On the last day, blood and livers were collected at CT3 (CT = circadian time) and CT15. In livers of WT mice, GCN2 phosphorylation followed a diurnal pattern that was guided by intracellular branched-chain amino acid concentrations (r2 = 0.93). Feeding LeuD to WT mice increased hepatic ISR activation at CT15 only. Diurnal oscillations in hepatic ISR signaling, the hepatic transcriptome including lipid metabolic genes, and triglyceride concentrations were substantially reduced or absent in GCN2 KO mice. Furthermore, mice lacking GCN2 were unable to maintain circadian rhythms in whole body energy expenditure, respiratory exchange ratio, and physical activity when fed LeuD. In conclusion, GCN2 activation functions to maintain diurnal ISR activation in the liver and has a vital role in the mechanisms by which nutrient stress affects whole body metabolism.NEW & NOTEWORTHY This work reveals that the eIF2 kinase GCN2 functions to support diurnal patterns in the hepatic integrated stress response during natural feeding and is necessary to maintain circadian rhythms in energy expenditure, respiratory exchange ratio, and physical activity during amino acid stress.

Aged fragmented-polypropylene microplastics induced ageing statues-dependent bioenergetic imbalance and reductive stress: In vivo and liver organoids-based in vitro study

Ageing is a nature process of microplastics that occurrs daily, and human beings are inevitably exposed to aged microplastics. However, a systematic understanding of ageing status and its toxic effect is currently still lacking. In this study, plastic cup lids-originated polypropylene (PP) microplastics were UV-photoaged until the carbonyl index (CI), a canonical indicator for plastic ageing, achieved 0.08, 0.17, 0.22 and 0.28. The adverse hepatic effect of these aged PPs (aPPs) was evaluated in Balb/c mice (75 ng/mL water, about 200 particles/day) and human-originated liver organoids (LOs, 50 particles/mL, ranged from 5.94 to 13.15 ng/mL) at low-dose equivalent to human exposure level. Low-dose of aged PP could induce hepatic reductive stress both in vitro and in vivo, by elevating the NADH/NAD+ratio in a CI-dependent manner, together with hepatoxicity (indicated by increased AST secretion and cytotoxicity), and disrupted the genes encoding the nutrients transporters and NADH subunits accompanied by the restricted ATP supply, declined mitochondrial membrane potential and mitochondrial complexI/IV activities, without significant increase in MDA levels in the liver. These changes in the liver disrupted systematic metabolism, representing a circulatory panel of increases in the lactate, triglyceride, Fgf21 levels, and decreases in the pyruvate level, linked the reductive stress to the declined body weight gain but elevated hepatic NADH contents following aPPs exposure. Additionally, assessing by the LOs, it was found that digestion drastically accelerated the ageing of aPPs and worsen the energy supply upon mitochondria, representing a “scattergun effect” induced by the formation of micro- and nano-plastics mixture toward NADH/NAD+imbalance.

Hepatic stress in acute kidney injury.

Hepatic stress in acute kidney injury.

Reversal of hepatic accumulation of nordeoxycholic acid underlines the beneficial effects of cholestyramine on alcohol-associated liver disease in mice.

Dysregulation of bile acids (BAs) has been reported in alcohol-associated liver disease. However, the causal relationship between BA dyshomeostasis and alcohol-associated liver disease remains unclear. The study aimed to determine whether correcting BA perturbation protects against alcohol-associated liver disease and elucidate the underlying mechanism. BA sequestrant cholestyramine (CTM) was administered to C57BL/6J mice fed alcohol for 8 weeks to assess its protective effect and explore potential BA targets. The causal relationship between identified BA metabolite and cellular damage was examined in hepatocytes, with further manipulation of the detoxifying enzyme cytochrome p450 3A11. The toxicity of the BA metabolite was further validated in mice in an acute study. We found that CTM effectively reversed hepatic BA accumulation, leading to a reversal of alcohol-induced hepatic inflammation, cell death, endoplasmic reticulum stress, and autophagy dysfunction. Specifically, nordeoxycholic acid (NorDCA), a hydrophobic BA metabolite, was identified as predominantly upregulated by alcohol and reduced by CTM. Hepatic cytochrome p450 3A11 expression was in parallel with NorDCA levels, being upregulated by alcohol and reduced by CTM. Moreover, CTM reversed alcohol-induced gut barrier disruption and endotoxin translocation. Mechanistically, NorDCA was implicated in causing endoplasmic reticulum stress, suppressing autophagy flux, and inducing cell injury, and such deleterious effects could be mitigated by cytochrome p450 3A11 overexpression. Acute NorDCA administration in mice significantly induced hepatic inflammation and injury along with disrupting gut barrier integrity, leading to subsequent endotoxemia. Our study demonstrated that CTM treatment effectively reversed alcohol-induced liver injury in mice. The beneficial effects of BA sequestrant involve lowering toxic NorDCA levels. NorDCA not only worsens hepatic endoplasmic reticulum stress and inhibits autophagy but also mediates gut barrier disruption and systemic translocation of pathogen-associated molecular patterns in mice.

Alcohol- and Low-Iron Induced Changes in Antioxidant and Energy Metabolism Associated with Protein Lys Acetylation.

Understanding the role of iron in ethanol-derived hepatic stress could help elucidate the efficacy of dietary or clinical interventions designed to minimize liver damage from chronic alcohol consumption. We hypothesized that normal levels of iron are involved in ethanol-derived liver damage and reduced dietary iron intake would lower the damage caused by ethanol. We used a pair-fed mouse model utilizing basal Lieber-DeCarli liquid diets for 22 weeks to test this hypothesis. In our mouse model, chronic ethanol exposure led to mild hepatic stress possibly characteristic of early-stage alcoholic liver disease, seen as increases in liver-to-body weight ratios. Dietary iron restriction caused a slight decrease in non-heme iron and ferritin (FeRL) expression while it increased transferrin receptor 1 (TfR1) expression without changing ferroportin 1 (FPN1) expression. It also elevated protein lysine acetylation to a more significant level than in ethanol-fed mice under normal dietary iron conditions. Interestingly, iron restriction led to an additional reduction in nicotinamide adenine dinucleotide (NAD+) and NADH levels. Consistent with this observation, the major mitochondrial NAD+-dependent deacetylase, NAD-dependent deacetylase sirtuin-3 (SIRT3), expression was significantly reduced causing increased protein lysine acetylation in ethanol-fed mice at normal and low-iron conditions. In addition, the detection of superoxide dismutase 1 and 2 levels (SOD1 and SOD2) and oxidative phosphorylation (OXPHOS) complex activities allowed us to evaluate the changes in antioxidant and energy metabolism regulated by ethanol consumption at normal and low-iron conditions. We observed that the ethanol-fed mice had mild liver damage associated with reduced energy and antioxidant metabolism. On the other hand, iron restriction may exacerbate certain activities of ethanol further, such as increased protein lysine acetylation and reduced antioxidant metabolism. This metabolic change may prove a barrier to the effectiveness of dietary reduction of iron intake as a preventative measure in chronic alcohol consumption.

Hepatic stearoyl-CoA desaturase-1 deficiency induces fibrosis and hepatocellular carcinoma-related gene activation under a high carbohydrate low fat diet

Stearoyl-CoA desaturase-1 (SCD1) is a pivotal enzyme in lipogenesis, which catalyzes the synthesis of monounsaturated fatty acids (MUFA) from saturated fatty acids, whose ablation downregulates lipid synthesis, preventing steatosis and obesity. Yet deletion of SCD1 promotes hepatic inflammation and endoplasmic reticulum stress, raising the question of whether hepatic SCD1 deficiency promotes further liver damage, including fibrosis. To delineate whether SCD1 deficiency predisposes the liver to fibrosis, cirrhosis, and hepatocellular carcinoma (HCC), we employed in vivo SCD1 deficient global and liver-specific mouse models fed a high carbohydrate low-fat diet and in vitro established AML12 mouse cells. The absence of liver SCD1 remarkably increased the saturation of liver lipid species, as indicated by lipidomic analysis, and led to hepatic fibrosis. Consistently, SCD1 deficiency promoted hepatic gene expression related to fibrosis, cirrhosis, and HCC. Deletion of SCD1 increased the circulating levels of Osteopontin, known to be increased in fibrosis, and alpha-fetoprotein, often used as an early marker and a prognostic marker for patients with HCC. De novo lipogenesis or dietary supplementation of oleate, an SCD1-generated MUFA, restored the gene expression related to fibrosis, cirrhosis, and HCC. Although SCD1 deficient mice are protected against obesity and fatty liver, our results show that MUFA deprivation results in liver injury, including fibrosis, thus providing novel insights between MUFA insufficiency and pathways leading to fibrosis, cirrhosis, and HCC under lean non-steatotic conditions.

Protective Effects of Hepatocyte Stress Defenders, Nrf1 and Nrf2, against MASLD Progression.

Progression of metabolic dysfunction-associated steatites liver disease (MASLD) to steatohepatitis (MASH) is driven by stress-inducing lipids that promote liver inflammation and fibrosis, and MASH can lead to cirrhosis and hepatocellular carcinoma. Previously, we showed coordinated defenses regulated by transcription factors, nuclear factor erythroid 2-related factor-1 (Nrf1) and -2 (Nrf2), protect against hepatic lipid stress. Here, we investigated protective effects of hepatocyte Nrf1 and Nrf2 against MASH-linked liver fibrosis and tumorigenesis. Male and female mice with flox alleles for genes encoding Nrf1 (Nfe2l1), Nrf2 (Nfe2l2), or both were fed a MASH-inducing diet enriched with high fat, fructose, and cholesterol (HFFC) or a control diet for 24-52 weeks. During this period, hepatocyte Nrf1, Nrf2, or combined deficiency for ~7 days, ~7 weeks, and ~35 weeks was induced by administering mice hepatocyte-targeting adeno-associated virus (AAV) expressing Cre recombinase. The effects on MASH, markers of liver fibrosis and proliferation, and liver tumorigenesis were compared to control mice receiving AAV-expressing green fluorescent protein. Also, to assess the impact of Nrf1 and Nrf2 induction on liver fibrosis, HFFC diet-fed C57bl/6J mice received weekly injections of carbon tetrachloride, and from week 16 to 24, mice were treated with the Nrf2-activating drug bardoxolone, hepatocyte overexpression of human NRF1 (hNRF1), or both, and these groups were compared to control. Compared to the control diet, 24-week feeding with the HFFC diet increased bodyweight as well as liver weight, steatosis, and inflammation. It also increased hepatocyte proliferation and a marker of liver damage, p62. Hepatocyte Nrf1 and combined deficiency increased liver steatosis in control diet-fed but not HFFC diet-fed mice, and increased liver inflammation under both diet conditions. Hepatocyte Nrf1 deficiency also increased hepatocyte proliferation, whereas combined deficiency did not, and this also occurred for p62 level in control diet-fed conditions. In 52-week HFFC diet-fed mice, 35 weeks of hepatocyte Nrf1 deficiency, but not combined deficiency, resulted in more liver tumors in male mice, but not in female mice. In contrast, hepatocyte Nrf2 deficiency had no effect on any of these parameters. However, in the 15-week CCL4-exposed and 24-week HFFC diet-fed mice, Nrf2 induction with bardoxolone reduced liver steatosis, inflammation, fibrosis, and proliferation. Induction of hepatic Nrf1 activity with hNRF1 enhanced the effect of bardoxolone on steatosis and may have stimulated liver progenitor cells. Physiologic Nrf1 delays MASLD progression, Nrf2 induction alleviates MASH, and combined enhancement synergistically protects against steatosis and may facilitate liver repair.

New Insights on Using Oral Semaglutide versus Dapagliflozin in Patients with Type 2 Diabetes and Metabolic Dysfunction-Associated Steatotic Liver Disease.

Increases in both the prevalence and severity of metabolic dysfunction-associated steatotic liver disease (MASLD) and obesity are closely related. Type 2 diabetes (T2DM) has been associated with metabolic dysfunction-associated steatohepatitis (MASH)-related cirrhosis and hepatocellular carcinoma. Semaglutide is a glucagon-like peptide-1 (GLP-1) receptor agonist approved for the treatment of T2DM and has an important role in weight loss. Also, it may represent a new therapeutic option for the treatment of MASH in obese diabetic patients. The main outcomes were changes from baseline in liver steatosis and fibrosis at week 24. A total of one hundred eighty-seven patients with T2DM were eligible for this prospective study; ninety-five subjects were treated with oral semaglutide, and ninety-two patients were treated with dapagliflozin as an add-on to metformin. All the subjects were evaluated using Vibration Controlled Transient Elastography (VCTE) from June to December 2022. From our cohort, 54% of the patients were females, with a mean age of 59.92 ± 11.89 years and a mean body mass index (BMI) of 29.53 ± 5.33 kg/m2. Following a six-month medication period, we observed a substantial reduction in anthropometric measurements, including the BMI, waist circumference (WC), and waist-to-hip ratio (WtHr), in both groups. Regarding HbA1c, a notable decrease was observed in the semaglutide group (p < 0.001) when compared to the dapagliflozin group (p = 0.011). In addition, the liver stiffness measurement (LSM) according to VCTE improved significantly in the semaglutide group participants from 8.07 ± 2.90 kPa at baseline to 6.51 ± 3.09 kPa after medication (p < 0.001). The superior metabolic effects of semaglutide, correlated to dapagliflozin, may contribute to a more efficient decrease in hepatic stress and injury, leading to a substantial enhancement of liver function in T2DM patients. Further investigations conducted over an ideal timeframe are necessary to confirm the evidence presented in this study.

Liver matrin-3 protects mice against hepatic steatosis and stress response via constitutive androstane receptor

ObjectiveThe prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) continues to rise with the increasing obesity epidemic. Rezdiffra as an activator of a thyroid hormone receptor-beta is the only Food and Drug Administration approved therapy. As such, there is a critical need to improve our understanding of gene expression regulation and signaling transduction in MASLD to develop new therapies. Matrin-3 is a DNA- and RNA-binding protein involved in the pathogenesis of human diseases. Here we examined its previously uncharacterized role in limiting hepatic steatosis and stress response via the constitutive androstane receptor (CAR). MethodsMatrin-3 floxed and liver-specific knockout mice were fed either a chow diet or 60 kcal% high-fat diet (HFD) for up to 16 weeks. The mice were euthanized for different analysis including liver histology, lipid levels, and gene expression. Bulk RNA-seq, bulk ATAC-seq, and single-nucleus Multiome were used to examine changes of transcriptome and chromatin accessibility in the liver. Integrative bioinformatics analysis of our data and publicly available datasets and different biochemical assays were performed to identify underlying the molecular mechanisms mediating matrin-3's effects. Liver-tropic adeno-associated virus was used to restore the expression of CAR for lipid, acute phase genes, and histological analysis. ResultsMatrin-3 expression is induced in the steatotic livers of mice. Liver-specific matrin-3 deletion exacerbated HFD-induced steatosis, acute phase response, and inflammation in the liver of female mice. The transcriptome and chromatin accessibility were re-programmed in the liver of these mice with signatures indicating that CAR signaling is dysregulated. Mechanistically, matrin-3 interacts with CAR mRNA, and matrin-3 deficiency promotes CAR mRNA degradation. Consequently, matrin-3 deletion impaired CAR signaling by reducing CAR expression. Matrin-3 levels positively correlate with CAR expression in human livers. Ces2a and Il1r1 were identified as new target genes of CAR. Interestingly, we found that CAR discords with the expression of its target genes including Cyp2b10 and Ces2a in response to HFD, indicating CAR signaling is dysregulated by HFD despite increased CAR expression. Dysregulated CAR signaling upon matrin-3 deficiency reduced Ces2a and de-repressed Il1r1 expression. CAR restoration partially abrogated the dysregulated gene expression, exacerbated hepatic steatosis, acute phase response, and inflammation in liver-specific matrin-3 knockout mice fed a HFD. ConclusionsOur findings demonstrate that matrin-3 is a key upstream regulator maintaining CAR signaling upon metabolic stress, and the matrin-3-CAR axis limits hepatic steatosis and stress response signaling that may give insights for therapeutic intervention.

Biological Functions and Potential Therapeutic Significance of O-GlcNAcylation in Hepatic Cellular Stress and Liver Diseases.

O-linked-β-D-N-acetylglucosamine (O-GlcNAc) glycosylation (O-GlcNAcylation), which is dynamically regulated by O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), is a post-translational modification involved in multiple cellular processes. O-GlcNAcylation of proteins can regulate their biological functions via crosstalk with other post-translational modifications, such as phosphorylation, ubiquitination, acetylation, and methylation. Liver diseases are a major cause of death worldwide; yet, key pathological features of the disease, such as inflammation, fibrosis, steatosis, and tumorigenesis, are not fully understood. The dysregulation of O-GlcNAcylation has been shown to be involved in some severe hepatic cellular stress, viral hepatitis, liver fibrosis, nonalcoholic fatty acid liver disease (NAFLD), malignant progression, and drug resistance of hepatocellular carcinoma (HCC) through multiple molecular signaling pathways. Here, we summarize the emerging link between O-GlcNAcylation and hepatic pathological processes and provide information about the development of therapeutic strategies for liver diseases.

Triclosan administration to humanized UDP-glucuronosyltransferase 1 neonatal mice induces UGT1A1 through a dependence on PPARα and ATF4

Triclosan (TCS) is an antimicrobial toxicant found in a myriad of consumer products and has been detected in human tissues, including breastmilk. We have evaluated the impact of lactational TCS on UDP-glucuronosyltransferase 1A1 (UGT1A1) expression and bilirubin metabolism in humanized UGT1 (hUGT1) neonatal mice. In hUGT1 mice, expression of the hepatic UGT1A1 gene is developmentally delayed resulting in elevated total serum bilirubin (TSB) levels. We found that newborn hUGT1 mice breastfed or orally treated with TCS presented lower TSB levels along with induction of hepatic UGT1A1. Lactational and oral treatment by gavage with TCS leads to the activation of hepatic nuclear receptors constitutive androstane receptor (CAR), peroxisome proliferator-activated receptor alpha (PPARα), and stress sensor, activating transcription factor 4 (ATF4). When CAR-deficient hUGT1 mice (hUGT1/Car-/-) were treated with TCS, TSB levels were reduced with a robust induction of hepatic UGT1A1, leaving us to conclude that CAR is not tied to UGT1A1 induction. Alternatively, when PPARα-deficient hUGT1 mice (hUGT1/Pparα-/-) were treated with TCS, hepatic UGT1A1 was not induced. Additionally, we had previously demonstrated that TCS is a potent inducer of ATF4, a transcriptional factor linked to the integrated stress response. When ATF4 was deleted in liver of hUGT1 mice (hUGT1/Atf4ΔHep) and these mice treated with TCS, we observed superinduction of hepatic UGT1A1. Oxidative stress genes in livers of hUGT1/Atf4ΔHep treated with TCS were increased, suggesting that ATF4 protects liver from excessive oxidative stress. The increase oxidative stress may be associated with superinduction of UGT1A1. The expression of ATF4 in neonatal hUGT1 hepatic tissue may play a role in the developmental repression of UGT1A1.