The incidence of nonalcoholic steatohepatitis (NASH) is increasing annually, posing a significant threat to human health. NASH is typified by hepatic steatosis, inflammation, and hepatocellular injury, frequently culminating in fibrosis and cirrhosis. Yet, the precise pathogenesis of NASH remains to be fully elucidated. The hepatic sinusoid, which serves as the fundamental structural and functional unit of the liver, is intricately composed of endothelial cells, Kupffer cells, and hepatic stellate cells. Consequently, the homeostasis of the hepatic sinusoidal microenvironment may exert a pivotal influence on the progression and prognosis of NASH. However, the limitations of current NASH animal models have significantly impeded advancements in understanding the disease's pathogenesis and the development of effective therapeutic interventions. In light of these challenges, this review endeavors to delve deeper into the critical role of hepatic sinusoidal microenvironment homeostasis in the pathogenesis of NASH, critically analyze the commonly employed animal models, and comprehensively summarize the most recent and promising developments in drug research and development. It is anticipated that these efforts will collectively expedite the advancement of the field of NASH research and therapeutic innovation.

Sotagliflozin, a dual SGLT1/2 inhibitor, enhances glucagon like peptide-1 (GLP-1) levels and GLP-1 receptor agonists are used to manage non-alcoholic fatty liver disease (NAFLD). Study investigates the effects of sotagliflozin on NAFLD, alone and combined with linagliptin, comparing outcomes in normoglycemic and hyperglycemic animal models.Obese fatty liver disease (FLD) model was induced by high-fat diet (HFD) feeding, while a diabetic non-alcoholic steatohepatitis (NASH) model was developed by administering a single dose of streptozotocin to neonatal mice, followed by HFD feeding post-weaning. At termination of the study, parameters including biochemical markers, inflammatory cytokines, hepatic lipid content, and histopathology were assessed.In NASH mice, sotagliflozin and linagliptin reduced hepatic triglycerides by 60% and 44%, respectively, and cholesterol by 46% and 49%. Their combination further decreased triglycerides by 68.5% and cholesterol by 83.9%. In FLD mice, sotagliflozin and linagliptin reduced triglycerides by 33% and 17%, respectively, and cholesterol by 46% and 21%. Combination treatment offered no benefit, reducing triglycerides by 38% and cholesterol by 27%. Both the treatments improved plasma fibroblast growth factor 21, hepatic interlukin-6, glucose tolerance, steatosis and mitigated fat pad weight, but their combination did not show additional benefit. However, combination treatment demonstrated added benefit in modulating NAFLD activity score, liver enzymes, glycogenated hepatic nuclei, plasma glucose and active GLP-1 levels.Study underscores sotagliflozin's potential to mitigate NAFLD and highlights the benefit of combining it with linagliptin in hyperglycemic NASH model, which showed limited efficacy in normoglycemic FLD mice.

As a resource with a variety of medicinal and edible values, Zanthoxylum bungeanum Maxim has been found to improve high-fat diet-induced metabolic-associated fatty liver disease (MAFLD).

The aim of this study was to predict the main active metabolites in Z. bungeanum Maxim. Based on network analysis, and to explore and validate their potential mechanisms of action through lipidomics and transcriptomic techniques.

MAFLD mouse model and cell model were established to evaluate the effect of active components in Z. bungeanum Maxim. on MAFLD. Serum biochemical indexes, pathological staining observation, lipid group and transcriptome were used to verify the mechanism of action of active components in Z. bungeanum Maxim. on MAFLD.

Quercetin can regulate the liver lipid metabolites of MAFLD mice through the Glycerophospholipid metabolic pathway, thereby improving liver lipid accumulation and liver injury. At the same time, quercetin can also improve MAFLD by reducing oleic acid-induced lipid accumulation in HepG2 cells, and inhibit ferroptosis through the p38 MAPK/ERK signaling pathway, thereby alleviating the progression of MAFLD.

Quercetin isolated from Z. bungeanum Maxim. has ameliorative effects on MAFLD, probably mainly by affecting lipid metabolic pathways and MAPK signaling pathways.

Preventing the progression of liver damage to fibrosis would be beneficial for patients with steatotic liver disease (SLD). Mesenchymal stem cells (MSC) are a promising therapy for SLD and derived extracellular vesicles (EVs) could even improve the treatment's efficacy and safety. However, the mechanisms of MSC-EVs beneficial effects are not well known. It has been suggested that modifying the EVs cargo could improve their beneficial effects. The aims of this study were to assess if MSC-EVs reduce liver damage in a rat model of mild liver damage; to analyze the underlying mechanisms and to assess if silencing TGFβ enhances the beneficial effects of MSC-EVs. CCl4 was injected three times per week during four weeks to induce mild liver damage. EVs from human adipocyte MSC and from TGFβ-depleted MSC (siTGFβ-MSC-EVs) were injected in the tail vein. Steatosis, fibrosis, liver inflammation, macrophage infiltration and liver content of fibrotic markers, DAMPs, cytokines and bile acids were analyzed. Normal MSC-EVs reduce the CCL2 increase in liver, macrophage infiltration and the increases in the fibrosis markers collagen I and α-SMA. Treatment with siTGFβ-MSC-EVs, in addition, reduces liver steatosis, the increase of bile acids (mainly TCA), and DAMP HMGB1 levels, inducing a larger reduction of collagen I in liver of CCl4 rats. Treatment with MSCs-EVs effectively reduces early liver damage. Silencing of TGFβ in MSCs enhances the beneficial effects by additional mechanisms. Early treatment with MSC-EVs, especially after silencing TGFβ, could improve liver damage in SLD patients.

Although significant progress has been made in developing preclinical models for metabolic dysfunction-associated steatotic liver disease (MASLD), few have encapsulated the essential biological and clinical outcome elements reflective of the human condition. We conducted a comprehensive literature review of English-language original research articles published from 1990 to 2023, sourced from PubMed, Embase, and Web of Science, aiming to collate studies that provided a comparative analysis of physiological, metabolic, and hepatic histological characteristics between MASLD models and control groups. The establishment of a robust metabolic dysfunction-associated steatotic liver rodent model hinges on various factors, including animal species and strains, sex, induction agents and methodologies, and the duration of induction. Through this review, we aim to guide researchers in selecting suitable induction methods and animal species for constructing preclinical models aligned with their specific research objectives and laboratory conditions. Future studies should strive to develop simple, reliable, and reproducible models, considering the model's sensitivity to factors such as light-dark cycles, housing conditions, and environmental temperature. Additionally, the potential of diverse in vitro models, including 3D models and liver organ technology, warrants further exploration as valuable tools for unraveling the cellular mechanisms underlying fatty liver disease.

Recently, a significant negative correlation has been found between vitamin D (VD) and metabolic associated fatty liver disease (MAFLD), suggesting a potential beneficial role of VD in preventing of MAFLD, while underscoring the importance of exploring its mechanisms.

The experiment comprised two parts: male C57BL/6J mice (6 weeks) were fed a high-fat diet (HFD) and intraperitoneally injected with vitamin D3 (VD3) (1.68 IU/g/week) for 16 weeks. Meanwhile, palmitic acid (PA)-induced HepG2 cells were treated with 1,25(OH)2D3 (10 nM). The general conditions of the mice were evaluated by measuring body weight, liver/body weight, serum biochemical parameters, and inflammation indices. Additionally, injury-associated indices and histopathology were used to assess the severity of liver injury. Furthermore, indicators of ferroptosis, including lipid peroxidation, iron aggregation, and the aberrant expression of related proteins, were determined using Prussian blue staining, ELISA assay, and Western blot.

Long-term VD3 administration significantly reduced body weight gain and the liver/body weight ratio of HFD-induced MAFLD mice, while also improving serum lipid metabolism dysregulation and enhancing insulin sensitivity. The changes in the expressions of liver injury indices and histological manifestations due to VD3 treatment indicated that VD3 may exerts beneficial effects on liver injury through inhibiting inflammatory cell infiltration and vacuolation. Importantly, VD3 supplementation also inhibited ferroptosis by enhancing the body's antioxidant capacity, reducing local iron aggregation, and modulating the expression levels of ferroptosis-related proteins. These findings were further confirmed in a PA-induced HepG2 steatosis cell model, highlighting the pharmacological effects of VD.

VD shows promise in mitigating HFD -induced liver injury by improving metabolic dysregulation and inhibiting ferroptosis, suggesting therapeutic potential in MAFLD.

Non-alcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease in recent years, but the pathogenesis is not fully understood. Therefore, it is important to establish an effective animal model for studying NAFLD.

Adult zebrafish were fed a normal diet or a high-fat diet combined with egg yolk powder for 30 days. Body mass index (BMI) was measured to determine overall obesity. Serum lipids were measured using triglyceride (TG) and total cholesterol (TC) kits. Liver lipid deposition was detected by Oil Red O staining. Liver injury was assessed by measuring glutathione aminotransferase (AST) and glutamic acid aminotransferase (ALT) levels. Reactive oxygen species (ROS) and malondialdehyde (MDA) were used to evaluate oxidative damage. The level of inflammation was assessed by qRT-PCR for pro-inflammatory factors. H&E staining was used for pathological histology. Caspase-3 immunofluorescence measured apoptosis. Physiological disruption was assessed via RNA-seq analysis of genes at the transcriptional level and validated by qRT-PCR.

The high-fat diet led to significant obesity in zebrafish, with elevated BMI, hepatic TC, and TG. Severe lipid deposition in the liver was observed by ORO and H&E staining, accompanied by massive steatosis and ballooning. Serum AST and ALT levels were elevated, and significant liver damage was observed. The antioxidant system in the body was severely imbalanced. Hepatocytes showed massive apoptosis. RNA-seq results indicated that several physiological processes, including endoplasmic reticulum stress, and glucolipid metabolism, were disrupted.

Additional feeding of egg yolk powder to adult zebrafish for 30 consecutive days can mimic the pathology of human nonalcoholic fatty liver disease.

Current lifestyles are leading to a worldwide increase in metabolic liver diseases that favor the development of liver disease. Changes in hepatocytes are caused by altered lipid concentrations, oxidative stress or toxicity by individual lipids. The complexity of the underlying processes and differences of the pathology to proposed rodent models makes the development of an effective targeted therapy difficult. The lipid mobilization that occurs in dairy cows in the postpartum period could be a natural model for the metabolic stress commonly observed in the development of liver diseases. We therefore used gas chromatography and histopathological staining techniques to analyze lipid patterns in diparous and multiparous cows during the peripartum period. The most striking change in lipid composition is the homogenous increase in palmitoleic acid (C16:1n7) content in all cows around the time of calving, with multiparous cows exhibiting consistently higher C16:1n7 levels by the end of the study. Elevated C16:1n7 levels have a potential key role in the development of non-alcoholic steatohepatitis (NASH) and tumorigenesis in the liver. Changes in C16:1n7, therefore, support the idea that lipid mobilization in dairy cows could serve as model for various liver diseases, such as nonalcoholic fatty liver disease (NAFLD) or NASH development.

Nonalcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases worldwide; however, effective intervention strategies for NAFLD are still unavailable. The present study sought to investigate the efficacy of chiglitazar, a pan-PPAR agonist, in protecting against NAFLD in mice and its underlying molecular mechanism. Male C57BL/6 J mice were fed a high-fat diet (HFD) for 8 weeks to generate NAFLD and the HFD was continued for an additional 10 weeks in the absence or presence of 5 mg/kg/d or 10 mg/kg/d chiglitazar by gavage. Chiglitazar significantly improved dyslipidemia and insulin resistance, ameliorated hepatic steatosis and reduced liver inflammation and oxidative stress in NAFLD mice. RNA-seq revealed that chiglitazar alleviated HFD-induced NAFLD in mice through multiple pathways, including fatty acid metabolism regulation, insulin signaling pathway, and AMPK signaling pathway. This study demonstrated the potential therapeutic effect of chiglitazar on NAFLD. Chiglitazar ameliorated NAFLD by modulating multiple pathways.

Non-alcoholic steatohepatitis (NASH) is a severe liver condition characterized by excessive fat deposition, ballooning, and lobular inflammation. This investigation was conducted to estimate the capability of concomitant tamoxifen administration (TAM) with a high fat diet (HFD) to induce a reliable NASH model that mimics human NASH features. Rats were administered TAM (25 mg/kg/day p.o.) and consumed HFD for 5 weeks. A time-course investigation was conducted to determine the optimal time for NASH development. Liver function indices, hepatic lipid profile factors, oxidative stress biomarkers, and inflammatory mediators were estimated. Additionally, macroscopic and microscopic changes were examined. Compared with the time-matched control group receiving vehicle alone, TAM/HFD significantly impaired liver function indices represented as marked elevation in ALT, AST, and ALP serum levels. TAM/HFD significantly increased lipid profile factors including high TG and TC hepatic levels. Additionally, TAM/HFD remarkably raised hepatic levels of TNF-α and IL-17 and significantly decreased IL-10. The combination also increases the oxidative status evidenced by high content of MDA as well as low activity of GPx and SOD. Accordingly, the combination of TAM and HFD for 5 weeks collaboratively promotes NASH development by initiating compromised hepatocyte functionality, elevated lipid levels, oxidative stress, and liver inflammation.

Thyroid-stimulating hormone (TSH) is a pituitary hormone that stimulates the thyroid gland to produce and release thyroid hormones, primarily thyroxine and triiodothyronine. These hormones are key players in body-brain communication, influencing various physiological processes, including the regulation of metabolism (both peripheral and central effects), feedback mechanisms, and lipid metabolism. Recently, the increasing incidence of abnormal lipid metabolism has highlighted the link between thyroid function and lipid metabolism. Evidence suggests that TSH can affect all bodily systems through body-brain communication, playing a crucial role in growth, development, and the regulation of various physiological systems. Lipids serve dual purposes: they are involved in energy storage and metabolism, and they act as vital signaling molecules in numerous cellular activities, maintaining overall human health or contributing to various diseases. This article reviews the role of TSH in regulating lipid metabolism via body-brain crosstalk, focusing on its implications for common lipid metabolism disorders such as obesity, atherosclerosis, nonalcoholic fatty liver disease, neuropsychiatric disorders (including Alzheimer's disease, Parkinson's disease, multiple sclerosis, epilepsy, and depression), and cerebrovascular disorders such as stroke.

The prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH) is increasing, and translational animal models are needed to develop novel treatments for this disease. The physiology and metabolism of pigs have a relatively high resemblance to humans, and the present study aimed to characterize choline-deficient and high-fat diet (CDAHFD)-fed Göttingen Minipigs as a novel animal model of MASLD/MASH. Göttingen Minipigs were fed CDAHFD for up to 5 mo, and the phenotype was investigated by the analysis of plasma parameters and repeated collection of liver biopsies. Furthermore, changes in hepatic gene expression during the experiment were explored by RNA sequencing. For a subset of the minipigs, the diet was changed from CDAHFD back to chow to investigate whether the liver pathology was reversible. Göttingen Minipigs on CDAHFD gained body weight, and plasma levels of cholesterol, AST, ALT, ALP, and GGT were increased. CDAHFD-fed minipigs developed hepatic steatosis, inflammation, and fibrosis, which in 5 of 16 animals progressed to cirrhosis. During an 11-wk chow reversal period, steatosis regressed, while fibrosis persisted. Regarding inflammation, the findings were less clear, depending on the type of readout. MASH Human Proximity Scoring (combined evaluation of transcriptional, phenotypic, and histopathological parameters) showed that CDAHFD-fed Göttingen Minipigs resemble human MASLD/MASH better than most rodent models. In conclusion, CDAHFD-fed minipigs develop a MASH-like phenotype, which, in several aspects, resembles the changes observed in human patients with MASLD/MASH. Furthermore, repeated collection of liver biopsies allows detailed characterization of histopathological changes over time in individual animals.NEW & NOTEWORTHY The physiology and metabolism of pigs have a relatively high resemblance to humans. This study characterizes a new animal model of MASLD/MASH using CDAHFD-fed Göttingen Minipigs. Göttingen Minipigs fed CDAHFD gained weight and developed hepatic steatosis, inflammation, fibrosis, and cirrhosis. After an 11-wk chow-reversal period, hepatic steatosis and some inflammatory parameters reversed. Combined evaluation of phenotypic, transcriptional, and histological parameters revealed the minipig model showed a higher resemblance to human disease than many rodent models.

Nonalcoholic fatty liver disease (NAFLD) is a mainstream halting liver disease with high prevalence in North America, Europe, and other world regions. It is an advanced form of NAFLD caused by the amassing of fat in the liver and can progress to the more severe form known as non-alcoholic steatohepatitis (NASH). Until recently, there was no authorized pharmacotherapy reported for NASH, and to improve the patient's metabolic syndrome, the focus is mainly on lifestyle modification, weight loss, ensuring a healthy diet, and increased physical activity; however, the recent approval of Rezdiffra (Resmetirom) by the US FDA may change this narrative. As per the reported studies, there is an increased articulation of uptake and efflux transporters of the liver, including OATP and MRP, in NASH, leading to changes in the drug's pharmacokinetic properties. This increase leads to alterations in the pharmacokinetic properties of drugs. Furthermore, modifications in Cytochrome P450 (CYP) enzymes can have a significant impact on these properties. Xenobiotics are metabolized primarily in the liver and constitute liver enzymes and transporters. This review aims to delve into the role of metabolism, transport, and potential herb-drug interactions in the context of NASH.

Non-alcoholic fatty liver disease (NAFLD), with a global prevalence of 25%, continues to escalate, creating noteworthy concerns towards the global health burden. NAFLD causes triglycerides and free fatty acids to build up in the liver. The excessive fat build-up causes inflammation and damages the healthy hepatocytes, leading to non-alcoholic steatohepatitis (NASH). Dietary habits, obesity, insulin resistance, type 2 diabetes, and dyslipidemia influence NAFLD progression. The disease burden is complicated due to the paucity of therapeutic interventions. Obeticholic acid is the only approved therapeutic agent for NAFLD. With more scientific enterprise being directed towards the understanding of the underlying mechanisms of NAFLD, novel targets like lipid synthase, farnesoid X receptor signalling, peroxisome proliferator-activated receptors associated with inflammatory signalling, and hepatocellular injury have played a crucial role in the progression of NAFLD to NASH. Phytocompounds have shown promising results in modulating hepatic lipid metabolism and de novo lipogenesis, suggesting their possible role in managing NAFLD. This review discusses the ameliorative role of different classes of phytochemicals with molecular mechanisms in different cell lines and established animal models. These compounds may lead to the development of novel therapeutic strategies for NAFLD progression to NASH. This review also deliberates on phytomolecules undergoing clinical trials for effective management of NAFLD.

Steatotic liver disease (SLD) is generally considered to represent a hepatic manifestation of metabolic syndrome and includes a disease spectrum comprising isolated steatosis, metabolic dysfunction-associated steatohepatitis, liver fibrosis and ultimately cirrhosis. A better understanding of the detailed underlying pathogenic mechanisms of this transition is crucial for the design of new and efficient therapeutic interventions. Thymocyte differentiation antigen (Thy-1, also known as CD90) expression on fibroblasts controls central functions relevant to fibrogenesis, including proliferation, apoptosis, cytokine responsiveness, and myofibroblast differentiation.

The impact of Thy-1 on the development of SLD and progression to fibrosis was investigated in high-fat diet (HFD)-induced SLD wild-type and Thy-1-deficient mice. In addition, the serum soluble Thy-1 (sThy-1) concentration was analysed in patients with metabolic dysfunction-associated SLD stratified according to steatosis, inflammation, or liver fibrosis using noninvasive markers.

We demonstrated that Thy-1 attenuates the development of fatty liver and the expression of profibrogenic genes in the livers of HFD-induced SLD mice. Mechanistically, Thy-1 directly inhibits the profibrotic activation of nonparenchymal liver cells. In addition, Thy-1 prevents palmitic acid-mediated amplification of the inflammatory response of myeloid cells, which might indirectly contribute to the pronounced development of liver fibrosis in Thy-1-deficient mice. Serum analysis of patients with metabolically associated steatotic liver disease syndrome revealed that sThy-1 expression is correlated with liver fibrosis status, as assessed by liver stiffness, the Fib4 score, and the NAFLD fibrosis score.

Our data strongly suggest that Thy-1 may function as a fibrosis-protective factor in mouse and human SLD.

The Coptidis Rhizoma and Bovis Calculus herb pair possesses clearing heat and detoxifying effects. The aim of this study was to reveal the effects and mechanisms of the herb pair in the treatment of NASH by network pharmacology and experimental verification. A network pharmacology-based approach was employed to predict the putative mechanism of the herb pair against NASH. The high-fat diet (HFD) and methionine/choline deficient (MCD) diet induced NASH models were used to evaluate efficacy and mechanism of the herb pair. Network pharmacological analysis showed that the herb pair modulated NOD-like receptor pathway. In the HFD mice, herb pair reduced body weight, blood sugar, serum ALT, AST, TBA, TC, TG and LDL-C contents, also improved the general morphology and pathological manifestations. Hepatic transcriptomics study showed that herb pair attenuated NASH by regulating NOD-like receptor signaling pathway. Western blotting showed that herb pair reduced the protein expression levels of NLRP3, cleaved Caspase-1 and cleaved IL-1β. In the MCD mice, herb pair also reduced serum ALT, ALT and TBA levels, improved liver pathological manifestations, inhibited the protein expression levels of NLRP3, cleaved Caspase-1 and cleaved IL-1β. Our findings proved that the Coptidis Rhizoma and Bovis Calculus herb pair attenuates NASH through suppression of NLRP3 inflammasome activation. This will demonstrate effective pharmacological evidence for the clinical application of herb pair.

Organic anion transporting polypeptide (OATP) 1B1 and OATP1B3 (collectively, OATP1B) transporters encoded by the solute carrier organic anion transporter (SLCO) genes mediate uptake of multiple pharmaceutical compounds. Nonalcoholic steatohepatitis (NASH), a severe form of nonalcoholic fatty liver disease (NAFLD), decreases OATP1B abundance. This research characterized the pathologic and pharmacokinetics effects of three diet- and one chemical-induced NAFLD model in male and female humanized OATP1B mice, which comprises knock-out of rodent Oatp orthologs and insertion of human SLCO1B1 and SLCO1B3. Histopathology scoring demonstrated elevated steatosis and inflammation scores for all NAFLD-treatment groups. Female mice had minor changes in SLCO1B1 expression in two of the four NAFLD treatment groups, and pitavastatin (PIT) area under the concentration-time curve (AUC) increased in female mice in only one of the diet-induced models. OATP1B3 expression decreased in male and female mice in the chemical-induced NAFLD model, with a coinciding increase in PIT AUC, indicating the chemical-induced model may better replicate changes in OATP1B3 expression and OATP substrate disposition observed in NASH patients. This research also tested a reported multifactorial pharmacokinetic interaction between NAFLD and silymarin, an extract from milk thistle seeds with notable OATP-inhibitory effects. Males showed no change in PIT AUC, whereas female PIT AUC increased 1.55-fold from the diet alone and the 1.88-fold from the combination of diet with silymarin, suggesting that female mice are more sensitive to pharmacokinetic changes than male mice. Overall, the humanized OATP1B model should be used with caution for modeling NAFLD and multifactorial pharmacokinetic interactions. SIGNIFICANCE STATEMENT: Advanced stages of NAFLD cause decreased hepatic OATP1B abundance and increase systemic exposure to OATP substrates in human patients. The humanized OATP1B mouse strain may provide a clinically relevant model to recapitulate these observations and predict pharmacokinetic interactions in NAFLD. This research characterized three diet-induced and one drug-induced NAFLD model in a humanized OATP1B mouse model. Additionally, a multifactorial pharmacokinetic interaction was observed between silymarin and NAFLD.

Little is known about the effects of fructose on colonic function. Here, forty-eight 7-week-old male SD rats were randomly divided into four groups and given 0, 7.5%, 12.75%, and 35% fructose in diet for 8 weeks respectively to investigate the regulatory influence of fructose on colonic barrier function. The exact amount of fructose intake was tracked and recorded. We showed that fructose affects colonic barrier function in a dose-dependent manner. High-fructose at a dose of 1.69±0.23 g/kg/day could damage the physical barrier function of the colon by down-regulating expression of tight junction proteins (ZO-1 and occludin) and mucus layer biomarkers (MUC2 and TFF3). High fructose reduced sIgA and the anti-inflammatory cytokine (IL-10), induced abdominal fat accumulation and pro-inflammatory cytokines (IL-6 and IL-8), leading to colon inflammation and immune barrier dysfunction. In addition, high-fructose altered the biological barrier of the colon by decreasing the abundance of Blautia, Ruminococcus, and Lactobacillius, and increasing the abundance of Allobaculum at the genus level, leading to a reduction in short-chain fatty acids (SCFAs), amino acids, and carbohydrates, etc. Low fructose at a dose of 0.31±0.05 g/kg/day showed no adverse effects on the colonic barrier. The ability of fructose to affect the colonic barrier through physical, immune, and biological pathways provides additional insight into the intestinal disorders caused by high-fructose diets.

Sterol regulatory element-binding protein (SREBP)-1c is involved in cellular lipid homeostasis and cholesterol biosynthesis and is highly increased in nonalcoholic steatohepatitis (NASH). However, the molecular mechanism by which SREBP-1c regulates hepatic stellate cells (HSCs) activation in NASH animal models and patients have not been fully elucidated. In this study, we examined the role of SREBP-1c in NASH and the regulation of LCN2 gene expression. Wild-type and SREBP-1c knockout (1cKO) mice were fed a high-fat/high-sucrose diet, treated with carbon tetrachloride (CCl4), and subjected to lipocalin-2 (LCN2) overexpression. The role of LCN2 in NASH progression was assessed using mouse primary hepatocytes, Kupffer cells, and HSCs. LCN2 expression was examined in samples from normal patients and those with NASH. LCN2 gene expression and secretion increased in CCl4-induced liver fibrosis mice model, and SREBP-1c regulated LCN2 gene transcription. Moreover, treatment with holo-LCN2 stimulated intracellular iron accumulation and fibrosis-related gene expression in mouse primary HSCs, but these effects were not observed in 1cKO HSCs, indicating that SREBP-1c-induced LCN2 expression and secretion could stimulate HSCs activation through iron accumulation. Furthermore, LCN2 expression was strongly correlated with inflammation and fibrosis in patients with NASH. Our findings indicate that SREBP-1c regulates Lcn2 gene expression, contributing to diet-induced NASH. Reduced Lcn2 expression in 1cKO mice protects against NASH development. Therefore, the activation of Lcn2 by SREBP-1c establishes a new connection between iron and lipid metabolism, affecting inflammation and HSCs activation. These findings may lead to new therapeutic strategies for NASH.

Metabolic-associated steatotic liver disease (MASLD) encompasses a wide spectrum of metabolic conditions associated with an excess of fat accumulation in the liver, ranging from simple hepatic steatosis to cirrhosis and hepatocellular carcinoma. Finding appropriate tools to study its development and progression is essential to address essential unmet therapeutic and staging needs. This review discusses advantages and shortcomings of different dietary, chemical and genetic factors that can be used to mimic this disease and its progression in mice from a hepatic and metabolic point of view. Also, this review will highlight some additional factors and considerations that could have a strong impact on the outcomes of our model to end up providing recommendations and a checklist to facilitate the selection of the appropriate MASLD preclinical model based on clinical aims.

Moringa oleifera (MO) is a native tree of Asia and is cultivated in some areas of Mexico as part of traditional horticulture. The aim of the present study was to compare the efficacy of MO infusion vs. MO ethanolic extract for the simultaneous treatment of nonalcoholic fatty liver (NAFLD), hyperlipidemia, and hyperglycemia in a murine model fed with a high-fat diet (HFD). BALB/c mice were fed a balanced diet (healthy control) or an HFD for 6 months. With this, the NAFLD model was established before starting a therapeutic intervention with MO for two months. The phytochemical analysis by nuclear magnetic resonance in 1H and 13C experiments showed signals for pyrrole alkaloids and triterpenes as the main constituents of the extract and infusion preparation. A significant reduction of SGPT, SGOT, lipids, urea, and glucose in blood among NAFLD groups treated with MO (infusion or extract) was found, when compared to the NAFLD-placebo group. Steatosis and liver inflammation were found to be decreased in the MO groups, as infusion or ethanolic extract. Infusion produced a better therapeutic effect than the extract in all parameters, except glycemic control, where the extract was better. As an additional finding, it is noteworthy that treatment with MO, particularly through infusion, resulted in improved motor activity. Moreover, a reduction in anxiety-like behavior was observed exclusively with the administration of infusion. These observations provide valuable insights into the potential broader effects of Moringa oleifera beyond the primary aim of the study.

This study examined the preventative effects of esculeogenin A (ESGA), a newly discovered glycan from tomato, on liver damage and hepatic steatosis in high-fat-diet (HFD)-fed male rats. The animals were divided into six groups (each of eight rats): a control group fed a normal diet, control + ESGA (200 mg/kg), HFD, and HFD + ESAG in 3 doses (50, 100, and 200 mg/kg). Feeding and treatments were conducted for 12 weeks. Treatment with ESGA did not affect gains in the body or fat weight nor increases in fasting glucose, insulin, and HOMA-IR or serum levels of free fatty acids (FFAs), tumor-necrosis factor-α, and interleukin-6 (IL-6). On the contrary, it significantly reduced the serum levels of gamma-glutamyl transpeptidase (GGT), aspartate aminotransferase (AST), alanine aminotransferase (ALT), total triglycerides (TGs), cholesterol (CHOL), and low-density lipoprotein cholesterol (LDL-c) in the HFD-fed rats. In addition, it improved the liver structure, attenuating the increase in fat vacuoles; reduced levels of TGs and CHOL, and the mRNA levels of SREBP1 and acetyl CoA carboxylase (ACC); and upregulated the mRNA levels of proliferator-activated receptor α (PPARα) and carnitine palmitoyltransferase I (CPT I) in HFD-fed rats. These effects were concomitant with increases in the mRNA, cytoplasmic, and nuclear levels of nuclear factor erythroid 2-related factor 2 (Nrf2), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), and heme oxygenase-1 (HO); a reduction in the nuclear activity of nuclear factor-kappa beta (NF-κB); and inhibition of the activity of nuclear factor kappa B kinase subunit beta (IKKβ). All of these effects were dose-dependent effects in which a normal liver structure and normal levels of all measured parameters were seen in HFD + ESGA (200 mg/kg)-treated rats. In conclusion, ESGA prevents NAFLD in HFD-fed rats by attenuating hyperlipidemia, hepatic steatosis, oxidative stress, and inflammation by acting locally on Nrf2, NF-κB, SREBP1, and PPARα transcription factors.

Excessive fructose consumption may lead to metabolic syndrome, metabolic dysfunction-associated fatty liver disease (MAFLD) and hypertension. α1-adrenoceptors antagonists are antihypertensive agents that exert mild beneficial effects on the metabolic profile in hypertensive patients. However, they are no longer used as a first-line therapy for hypertension based on Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) outcomes. Later studies have shown that quinazoline-based α1-adrenolytics (prazosin, doxazosin) induce apoptosis; however, this effect was independent of α1-adrenoceptor blockade and was associated with the presence of quinazoline moiety. Recent studies showed that α1-adrenoceptors antagonists may reduce mortality in COVID-19 patients due to anti-inflammatory properties. MH-76 (1-[3-(2,6-dimethylphenoxy)propyl]-4-(2-methoxyphenyl)piperazine hydrochloride)) is a non-quinazoline α1-adrenoceptor antagonist which, in fructose-fed rats, exerted anti-inflammatory, antihypertensive properties and reduced insulin resistance and visceral adiposity. In this study, we aimed to evaluate the effect of fructose consumption and treatment with α1-adrenoceptor antagonists of different classes (MH-76 and prazosin) on liver tissue of fructose-fed rats. Livers were collected from four groups (Control, Fructose, Fructose + MH-76 and Fructose + Prazosin) and subjected to biochemical and histopathological studies. Both α1-adrenolytics reduced macrovesicular steatosis and triglycerides content of liver tissue and improved its antioxidant capacity. Treatment with MH-76, contrary to prazosin, reduced leucocytes infiltration as well as decreased elevated IL-6 and leptin concentrations. Moreover, the MH-76 hepatotoxicity in hepatoma HepG2 cells was less than that of prazosin. The use of α1-adrenolytics with anti-inflammatory properties may be an interesting option for treatment of hypertension with metabolic complications.

Pelargonic acid vanillylamide (PAVA) has been shown to reduce hepatic lipid accumulation in an obese rat model, however the underlying mechanism responsible for regulating lipid metabolism remains unclear. This study investigated the molecular mechanisms invoked by PAVA in regulating lipogenesis, autophagy, and endoplasmic reticulum (ER) stress in obese rats. Male Sprague-Dawley rats were fed on a diet consisting of 65.26% fat (16 weeks) and HepG2 cells were incubated with 200 μM oleic acid (OA) plus 100 μM palmitic acid (PA) for 48 h. These treatments resulted in a steatosis model. PAVA was shown to reduce fat deposition in hepatocytes in HepG2 by reducing lipotoxicity, the triglyceride content, the expression of sterol regulatory element binding protein 1c (SREBP-1c) and fatty acid synthase (FASN). PAVA also significantly reduced the calcium level and the expression of calpain 2 and upregulated the expression of Atg7 in comparison to the HFD group. In addition, PAVA was shown to significantly decrease the expression of autophagy pathway-related proteins including LC3 and p62. Treatment with PAVA (1 mg/day) reduced the expressions of ER stress markers Bip, ATF6 (p50), p-IRE1/IRE1, p-eIF2α/eIF2α, pJNK, CHOP and cleaved CASP12. In conclusion, PAVA ameliorated obesity induced hepatic steatosis by attenuating defective autophagy and ER stress pathways.

The nuclear receptor coactivator 5 (NCOA5) is a putative type 2 diabetes susceptibility gene. NCOA5 haploinsufficiency results in the spontaneous development of nonalcoholic fatty liver disease (NAFLD), insulin resistance, and hepatocellular carcinoma (HCC) in male mice; however, the cell-specific effect of NCOA5 haploinsufficiency in various types of cells, including macrophages, on the development of NAFLD and HCC remains unknown.

Control and myeloid-lineage-specific Ncoa5 deletion (Ncoa5ΔM/+) mice fed a normal diet were examined for the development of NAFLD, nonalcoholic steatohepatitis (NASH), and HCC. Altered genes and signaling pathways in the intrahepatic macrophages of Ncoa5ΔM/+ male mice were analyzed and compared with those of obese human individuals. The role of platelet factor 4 (PF4) in macrophages and the underlying mechanism by which PF4 affects NAFLD/NASH were explored in vitro and in vivo. PF4 expression in HCC patient specimens and prognosis was examined.

Myeloid-lineage-specific Ncoa5 deletion sufficiently causes spontaneous NASH and HCC development in male mice fed a normal diet. PF4 overexpression in Ncoa5ΔM/+ intrahepatic macrophages is identified as a potent mediator to trigger lipid accumulation in hepatocytes by inducing lipogenesis-promoting gene expression. The transcriptome of intrahepatic macrophages from Ncoa5ΔM/+ male mice resembles that of obese human individuals. High PF4 expression correlated with poor prognosis of HCC patients and increased infiltrations of M2 macrophages, regulatory T cells, and myeloid-derived suppressor cells in HCCs.

Our findings reveal a novel mechanism for the onset of NAFLD/NASH and HCC initiated by NCOA5-deficient macrophages, suggesting the NCOA5-PF4 axis in macrophages as a potential target for developing preventive and therapeutic interventions against NAFLD/NASH and HCC.

Metabolic dysfunction-associated steatotic liver disease (MASLD), previously known as Non-Alcoholic Fatty Liver Disease, is a widespread liver condition characterized by excessive fat buildup in hepatocytes without significant alcohol consumption. Manipulation of the gut microbiome has been considered to prevent and improve the occurrence and progression of MASLD, particularly through the gut-liver axis. This study aimed to investigate the correlation between the gut microbiome and liver function and determine whether the gut microbiome can ameliorate MASLD. We comparatively analyzed the gut microbiome composition between mice fed normal chow and those fed a high-fat diet and observed that the abundance of Kineothrix alysoides decreased in the high-fat group. Further analysis showed that treatment with K. alysoides in the high-fat diet group led to decreased weight loss, and MASLD attenuation. Importantly, K. alysoides treatment attenuated MASLD in mice fed a high-fat, high-fructose diet (HFHF), which can cause advanced liver damage. Furthermore, administration of K. alysoides altered the gut microbial composition in the HFHF diet group and improved MASLD. Overall, these findings demonstrate the potential of K. alysoides in restoring gut health and facilitating lipid metabolism to prevent and treat MASLD.

The current study aimed to study the therapeutic effects of lupeol as a nutritional triterpene on non-alcoholic fatty liver disease (NAFLD) and polycystic ovarian syndrome (PCOS) disorders in separate and concurrent models.

This study was performed in three sets and each set contained 4 groups of female mice (n = 6), including control, NAFLD or PCOS and/or NAFLD/PCOS, lupeol, and metformin (MET). The treatment groups following the induction of disorders were treated with lupeol (40 mg/kg, orally) or MET (500 mg/kg, orally) for 28 days. The insulin resistance index and hormonal assessments were conducted on the collected serum samples. Moreover, oxidative stress biomarkers were measured in the liver and ovaries. Histopathological studies and ultimately any changes in the expression of androgen receptors, toll-like receptor (TLR)-2 and TLR-4 were analyzed.

Results revealed that lupeol reduced significantly the insulin resistance index in NAFLD and NAFLD/PCOS-positive animals. Lupeol attenuated remarkably the PCOS and PCOS/NAFLD-elevated concentration of testosterone. lupeol recovered the metabolic disorders-induced oxidative stress and restored the disorders-depleted glutathione. The NAFLD/PCOS-induced hepatic damages such as microvesicular or macrovesicular steatosis and atretic follicles number in the ovary were attenuated in the lupeol-treated mice. Serum level of TNF-α was reduced and the expression of androgen receptors, TLR-4 and TLR-2 were downregulated in the lupeol-treated NAFLD/PCOS-positive animals.

The results suggest that lupeol could be a novel nutraceutical for the treatment of metabolic disorders. Lupeol's anti-metabolic disorders effects attribute to its anti-dyslipidemia, antioxidant, and anti-inflammatory properties.

Recent research has shown that the adhesion G protein-coupled receptor F1 (Adgrf1; also known as GPR110; PGR19; KPG_012; hGPCR36) is an oncogene. The evidence is mainly based on high expression of Adgrf1 in numerous cancer types, and knockdown Adgrf1 can reduce the cell migration, invasion, and proliferation. Adgrf1 is, however, mostly expressed in the liver of healthy individuals. The function of Adgrf1 in liver has not been revealed. Interestingly, expression level of hepatic Adgrf1 is dramatically decreased in obese subjects. Here, the research examined whether Adgrf1 has a role in liver metabolism.

We used recombinant adeno-associated virus-mediated gene delivery system, and antisense oligonucleotide was used to manipulate the hepatic Adgrf1 expression level in diet-induced obese mice to investigate the role of Adgrf1 in hepatic steatosis. The clinical relevance was examined using transcriptome profiling and archived biopsy specimens of liver tissues from non-alcoholic fatty liver disease (NAFLD) patients with different degree of fatty liver.

The expression of Adgrf1 in the liver was directly correlated to fat content in the livers of both obese mice and NAFLD patients. Stearoyl-coA desaturase 1 (Scd1), a crucial enzyme in hepatic de novo lipogenesis, was identified as a downstream target of Adgrf1 by RNA-sequencing analysis. Treatment with the liver-specific Scd1 inhibitor MK8245 and specific shRNAs against Scd1 in primary hepatocytes improved the hepatic steatosis of Adgrf1-overexpressing mice and lipid profile of hepatocytes, respectively.

These results indicate Adgrf1 regulates hepatic lipid metabolism through controlling the expression of Scd1. Downregulation of Adgrf1 expression can potentially serve as a protective mechanism to stop the overaccumulation of fat in the liver in obese subjects. Overall, the above findings not only reveal a new mechanism regulating the progression of NAFLD, but also proposed a novel therapeutic approach to combat NAFLD by targeting Adgrf1.

This work was supported by the National Natural Science Foundation of China (81870586), Area of Excellence (AoE/M-707/18), and General Research Fund (15101520) to CMW, and the National Natural Science Foundation of China (82270941, 81974117) to SJ.

Long-term ligand activation of PPARα in mice causes hepatocarcinogenesis through a mechanism that requires functional PPARα. However, hepatocarcinogenesis is diminished in both Ppara-null and PPARA-humanized mice, yet both lines develop age-related liver cancer independently of treatment with a PPARα agonist. Since PPARα is a master regulator of liver lipid metabolism in the liver, lipidomic analyses were carried out in wild-type, Ppara-null, and PPARA-humanized mice treated with and without the potent agonist GW7647. The levels of hepatic linoleic acid in Ppara-null and PPARA-humanized mice were markedly higher compared to wild-type controls, along with overall fatty liver. The number of liver CD4+ T cells was also lower in Ppara-null and PPARA-humanized mice and was negatively correlated with the elevated linoleic acid. Moreover, more senescent hepatocytes and lower serum TNFα and IFNγ levels were observed in Ppara-null and PPARA-humanized mice with age. These studies suggest a new role for PPARα in age-associated hepatocarcinogenesis due to altered lipid metabolism in Ppara-null and PPARA-humanized mice and the accumulation of linoleic acid as part of an overall fatty liver that is associated with loss of CD4+ T cells in the liver in both transgenic models. Since fatty liver is a known causal risk factor for liver cancer, Ppara-null and PPARA-humanized mice are valuable models for examining the mechanisms of PPARα and age-dependent hepatocarcinogenesis.

Non-alcoholic fatty liver disease (NAFLD) is currently plaguing the population at pandemic proportions and is expected to become more prevalent over the next decade. Recent epidemiological studies have demonstrated a correlation between the manifestation of NAFLD and ambient air pollution levels, which is exacerbated by other risk factors, such as diabetes, dyslipidemia, obesity, and hypertension. Exposure to airborne particulate matter has also been associated with inflammation, hepatic lipid accumulation, oxidative stress, fibrosis, and hepatocyte injury. While prolonged consumption of a high-fat (HF) diet is associated with NAFLD, little is known regarding the effects of inhaled traffic-generated air pollution, a ubiquitous environmental pollutant, on the pathogenesis of NAFLD. Therefore, we investigated the hypothesis that exposure to a mixture of gasoline and diesel engine emissions (MVE), coupled with the concurrent consumption of a HF diet, promotes the development of a NAFLD phenotype within the liver. Three-month-old male C57Bl/6 mice were placed on either a low-fat or HF diet and exposed via whole-body inhalation to either filtered (FA) air or MVE (30 µg PM/m3 gasoline engine emissions + 70 µg PM/m3 diesel engine emissions) 6 hr/day for 30 days. Histology revealed mild microvesicular steatosis and hepatocyte hypertrophy in response to MVE exposure alone, compared to FA controls, yielding a classification of "borderline NASH" under the criteria of the modified NAFLD active score (NAS) system. As anticipated, animals on a HF diet exhibited moderate steatosis; however, we also observed inflammatory infiltrates, hepatocyte hypertrophy, and increased lipid accumulation, with the combined effect of HF diet and MVE exposure. Our results indicate that inhalation exposure to traffic-generated air pollution initiates hepatocyte injury and further exacerbates lipid accumulation and hepatocyte injury induced by the consumption of a HF diet, thereby contributing to the progression of NAFLD-related pathologies.

Fatty liver diseases, including alcohol-associated liver disease (ALD) and nonalcoholic fatty liver disease nonalcoholic fatty liver disease (NAFLD), affect a large number of people worldwide and become one of the major causes of end-stage liver disease, such as liver cirrhosis and hepatocellular carcinoma (HCC). Unfortunately, there are currently no approved pharmacological treatments for ALD or NAFLD. This situation highlights the urgent need to explore new intervention targets and discover effective therapeutics for ALD and NAFLD. The lack of properly validated preclinical disease models is a major obstacle to the development of clinical therapies. ALD and NAFLD models have been in the development for decades, but there are still no models that recapitulate the full spectrum of ALD and NAFLD. Throughout this review, we summarize the current in vitro and in vivo models used for research on fatty liver diseases and discuss the advantages and limitations of these models.

The leading cause of death in patients with nonalcoholic fatty liver disease (NAFLD) is cardiovascular disease (CVD). However, the mechanisms are unknown. Mice deficient in hepatocyte proliferator-activated receptor-α (PPARα) (PparaHepKO) exhibit hepatic steatosis on a regular chow diet, making them prone to manifesting NAFLD. We hypothesized that the PparaHepKO mice might be predisposed to poorer cardiovascular phenotypes due to increased liver fat content. Therefore, we used PparaHepKO and littermate control mice fed a regular chow diet to avoid complications with a high-fat diet, such as insulin resistance and increased adiposity. After 30 wk on a standard diet, male PparaHepKO mice exhibited elevated hepatic fat content compared with littermates as measured by Echo MRI (11.95 ± 1.4 vs. 3.74 ± 1.4%, P < 0.05), hepatic triglycerides (1.4 ± 0.10 vs. 0.3 ± 0.01 mM, P < 0.05), and Oil Red O staining, despite body weight, fasting blood glucose, and insulin levels being the same as controls. The PparaHepKO mice also displayed elevated mean arterial blood pressure (121 ± 4 vs. 108 ± 2 mmHg, P < 0.05), impaired diastolic function, cardiac remodeling, and enhanced vascular stiffness. To determine mechanisms controlling the increase in stiffness in the aorta, we used state-of-the-art PamGene technology to measure kinase activity in this tissue. Our data suggest that the loss of hepatic PPARα induces alterations in the aortas that reduce the kinase activity of tropomyosin receptor kinases and p70S6K kinase, which might contribute to the pathogenesis of NAFLD-induced CVD. These data indicate that hepatic PPARα protects the cardiovascular system through some as-of-yet undefined mechanism.

The prevalence of nonalcoholic fatty liver disease (NAFLD) is much higher in patients with type II diabetes (T2D). Inflammasomes are multimolecular complexes reported to involve inflammatory conditions. The nuclear factor (erythroid-derived 2)-like factor 2/antioxidant responsive element (Nrf2/ARE) pathway is an important regulator of antioxidant status in cells. Antidiabetic drug glibenclamide (GLB) is reported as  NACHT, leucine-rich repeat, and pyrin domain domains-containing protein 3 (NLRP3) inflammasome inhibitor, whereas anti-multiple sclerosis drug dimethyl fumarate (DMF) is reported as an Nrf2/ARE pathway activator. Both GLB and DMF possess anti-inflammatory and antioxidant properties, therefore, the hypothesis was made to look into the alone as well as the combination potential of GLB, DMF, and GLB + DMF, against NAFLD in diabetic rats. This study was aimed to investigate (1) the involvement of NLRP3 inflammasome and Nrf2/ARE signaling in diabetes-associated NAFLD (2) the effect of GLB, DMF, GLB + DMF, and metformin (MET) interventions on NLRP3 inflammasome and Nrf2/ARE signaling in diabetes-associated NAFLD. The rats were injected with streptozotocin (STZ) 35 mg/kg and fed a high-fat diet (HFD) for 17 consecutive weeks to induce diabetic NAFLD. The oral treatment of GLB 0.5 mg/kg/day, DMF 25 mg/kg/day, their combination and MET 200 mg/kg/day, were provided from the 6th to the 17th week. Treatment with GLB, DMF, GLB + DMF, and MET significantly alleviated HFD + STZ-induced plasma glucose, triglycerides, cholesterol, %HbA1c, hepatic steatosis, NLRP3, apoptosis-associated speck-like protein containing a caspase activation and recruitment domain, CARD, caspase-1, interleukin-1β (IL-1β), nuclear factor-κB (NF-κB), Nrf2, superoxide dismutase 1, catalase, IGF 1, heme oxygenase 1, receptor for the advanced glycation end product (RAGE), and collagen-1 in diabetic rats. Further, a mechanistic molecular study employing other specific NLRP3 inhibitors and Nrf2 activators will significantly contribute to the development of novel therapy for fatty liver diseases.

The incidence of non-alcoholic fatty liver disease (NAFLD) is a continuously growing health problem worldwide, along with obesity. Therefore, both novel methods to efficiently study the manifestation of NAFLD and to analyze drug efficacy in pre-clinical models are needed. In the present study, we developed a deep neural network -based model to quantify micro- and macrovesicular steatosis in the liver on hematoxylin-eosin stained whole slide images (WSIs), using the cloud-based platform, Aiforia Create (Aiforia Technologies, Helsinki, Finland). The training data included a total of 101 WSIs from dietary interventions of wild-type mice and from two genetically modified (GM) mouse models with steatosis. The algorithm was trained for the following: to detect liver parenchyma, to exclude the blood vessels and any artefacts generated during tissue processing and image acquisition, to recognize and differentiate the areas of micro- and macrovesicular steatosis, and to quantify the recognized tissue area. The results of the image analysis replicated well the evaluation by expert pathologists, and correlated well with the liver fat content measured by EcoMRI ex vivo, and the correlation with total liver triglycerides were notable. In conclusion, the developed deep learning-based model is a novel tool for studying liver steatosis in mouse models on paraffin sections, and thus, can facilitate reliable quantification of the amount of steatosis in large preclinical study cohorts.

This study investigated the possible hepatoprotective effects of memantine, compared to pioglitazone, in rat steatohepatitis, emphasizing its role in modulating hepatic autophagy.

Metabolic syndrome (MetS) was provoked in adult male Wistar rats by a high fructose/fat/salt regimen for eight weeks. Then, rats were administered either memantine or pioglitazone daily for 10 weeks (both at 20 mg/kg, orally). An oral glucose tolerance test (OGTT) was done at the end of the study, and serum liver enzymes, lipids, and fasting blood glucose were measured. Also, hepatic contents of inflammatory, oxidative, and autophagy markers were quantified. Additionally, histopathological examinations of general hepatic structure and glycogen content were performed.

Compared to the MetS rats, memantine normalized fasting serum insulin, Homeostatic Model Assessment (HOMA-IR), serum lipids, and liver enzymes (ALT and AST). Memantine also markedly reduced hepatic inflammatory markers; NF-κB and TNF-α. In addition, hepatic NRF2 and GSH were augmented, while hepatic MDA was reduced by memantine. Interestingly, livers of the memantine group showed elevated Beclin1 and LC3 and reduced p62 contents compared to the MetS group indicating that memantine preserved hepatic autophagy. Histopathological examination revealed that memantine ameliorated hepatic steatosis and inflammation. Pioglitazone also mitigated most of the steatohepatitis-related changes, however, memantine was more effective in most of the studied parameters.

The hepatoprotective effect of memantine against steatohepatitis is mediated, at least partly, through conserving hepatic autophagy along with anti-inflammatory, antioxidant, and anti-fibrotic effects.

Nonalcoholic fatty liver disease (NAFLD) is relatively associated with comorbidities in obesity and metabolic inflammation. Low-grade inflammation following the high-fat diet (HFD)-induced NAFLD can promote the development of nonalcoholic steatohepatitis (NASH) through particularly liver-resident immune cell recruitment and hepatic nuclear factor kappa B (NF-κB) pathway. Therefore, inflammatory intervention may contribute to NASH reduction. Pelargonic acid vanillylamide (PAVA) or nonivamide is one of the pungent capsaicinoids of Capsicum species and has been found in chili peppers. Our previous study demonstrated that PAVA improved hepatic function, decreased oxidative stress and reduced apoptotic cell death but the insight role of PAVA on NAFLD is still unclear. Thus, this study aimed to investigate the underlying anti-inflammatory mechanism of PAVA in an NAFLD-rat model. Male Sprague Dawley rats were fed with normal diet or HFD for 16 weeks. Then high-fat rats were given vehicle or PAVA (1 mg/kg/day) for another 4 weeks. We found that PAVA alleviated hepatic inflammation associated with the reducing toll-like receptor 4/NF-κB pathway, showing significantly lower recruitment of cluster of differentiation 44. PAVA also maintained activity of insulin signaling pathway, and attenuated NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome formation. NAFLD progresses to NASH through transforming growth factor (TGF-β1), and also recovery to simple stage followed by PAVA suppresses pro-inflammatory cytokines such as tumor necrosis factor-α, interleukin-1β, interleukin-6, and Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) pathway. Therefore, our findings suggest that PAVA provides a novel therapeutic approach for NAFLD and slows the progression to NASH.

Ubiquitination and deubiquitination are reversible processes that modify the characteristics of target proteins, including stability, intracellular localization, and enzymatic activity. Ubiquitin-specific proteases (USPs) constitute the largest deubiquitinating enzyme family. To date, accumulating evidence indicates that several USPs positively and negatively affect metabolic diseases. USP22 in pancreatic β-cells, USP2 in adipose tissue macrophages, USP9X, 20, and 33 in myocytes, USP4, 7, 10, and 18 in hepatocytes, and USP2 in hypothalamus improve hyperglycemia, whereas USP19 in adipocytes, USP21 in myocytes, and USP2, 14, and 20 in hepatocytes promote hyperglycemia. In contrast, USP1, 5, 9X, 14, 15, 22, 36, and 48 modulate the progression of diabetic nephropathy, neuropathy, and/or retinopathy. USP4, 10, and 18 in hepatocytes ameliorates non-alcoholic fatty liver disease (NAFLD), while hepatic USP2, 11, 14, 19, and 20 exacerbate it. The roles of USP7 and 22 in hepatic disorders are controversial. USP9X, 14, 17, and 20 in vascular cells are postulated to be determinants of atherosclerosis. Moreover, mutations in the Usp8 and Usp48 loci in pituitary tumors cause Cushing syndrome. This review summarizes the current knowledge about the modulatory roles of USPs in energy metabolic disorders.

Little is known about the impact of morphological disorders in distinct zones on metabolic zonation. It was described recently that periportal fibrosis did affect the expression of CYP proteins, a set of pericentrally located drug-metabolizing enzymes. Here, we investigated whether periportal steatosis might have a similar effect. Periportal steatosis was induced in C57BL6/J mice by feeding a high-fat diet with low methionine/choline content for either two or four weeks. Steatosis severity was quantified using image analysis. Triglycerides and CYP activity were quantified in photometric or fluorometric assay. The distribution of CYP3A4, CYP1A2, CYP2D6, and CYP2E1 was visualized by immunohistochemistry. Pharmacokinetic parameters of test drugs were determined after injecting a drug cocktail (caffeine, codeine, and midazolam). The dietary model resulted in moderate to severe mixed steatosis confined to periportal and midzonal areas. Periportal steatosis did not affect the zonal distribution of CYP expression but the activity of selected CYPs was associated with steatosis severity. Caffeine elimination was accelerated by microvesicular steatosis, whereas midazolam elimination was delayed in macrovesicular steatosis. In summary, periportal steatosis affected parameters of pericentrally located drug metabolism. This observation calls for further investigations of the highly complex interrelationship between steatosis and drug metabolism and underlying signaling mechanisms.