Lipidomics in pathogenesis, progression and treatment of nonalcoholic steatohepatitis (NASH): Recent advances

Ultrasound-driven ROS-scavenging nanobubbles for synergistic NASH treatment via FXR activation

Non-alcoholic steatohepatitis (NASH) pathogenesis is primarily driven by lipotoxicity-induced oxidative stress and inflammation, yet effective treatments remain challenging to identify. In this work, a novel therapeutic approach was introduced via a ultrasound (US) -driven, reactive oxygen species (ROS) -scavenging and liver-targeted nanobubbles system, termed Apt-DTP-NBs@RSV@OCA, which co-encapsulated resveratrol (RSV) and obeticholic acid (OCA). This system provides a safe and efficient platform for specifically delivering these agents to the liver in the context of the NASH therapy. The synthesized nanobubbles showed a spherical morphology with an average diameter of 165 ± 6.05 nm, whose encapsulation efficiencies of approximately 93 % for RSV and 90 % for OCA were achieved. These nanobubbles exhibited the enhanced targeting and accumulation within NASH affected cells and the excellent biocompatibility in cytotoxicity experiments. Subsequently, in vitro assessments using HepG2 cells, Apt-DTP-NBs@RSV@OCA improved lipid metabolism and reduced ROS levels. It was also showed in vivo experiments in mice that the hepatic targeting of Apt-DTP-NBs@RSV@OCA increased their effective concentration within the liver. In addition, the hepatic-targeting and ultrasound-driving Apt-DTP-NBs@RSV@OCA nanocarriers enhanced the cellular uptake of RSV and OCA in a NASH cell model and improved ROS-scavenging capabilities. Meanwhile, these nanocarriers modulated lipid metabolism (triglycerides, total cholesterol), inflammatory cytokine metabolism (IL-4, IL-10, IL-15, TNF-α) and oxidative stress levels (SOD, MDA). Furthermore, mechanistic studies revealed that Apt-DTP-NBs@RSV@OCA activated the FXR/SHP signaling pathway, enhanced FoxO1 activity, and alleviated lipid accumulation, inflammation, and oxidative stress. In summary, these findings suggest that Apt-DTP-NBs@RSV@OCA pave a promising way for the treatment of NASH.

Lipidomic profiling reveals the dynamic changes of hepatic lipidome during the fasting-refeeding transition in mice

Liver plays a pivotal role in maintaining energy homeostasis during fasting-refeeding transition. We previously reported that fasting-refeeding induces the dynamic changes of liver size. However, the alterations in hepatic lipid profiles during these dynamic changes remain unclear. Therefore, the present study aimed to clarify the effect of fasting and refeeding on hepatic lipid homeostasis in mice using lipidomics analysis and to identify the specific lipids that vary during the fasting-refeeding transition. In this study, C57BL/6 mice were fasted for 24 h and subsequently refed for 1, 3, 6, 12, and 24 h, respectively. Liver and serum samples were collected at each time point for further analysis. The results demonstrated that fasting obviously decreased the liver size accompanying with hepatic lipid accumulation, which were all returned to normal level after refeeding. Lipidomics analysis revealed that a total of 309 lipids were significantly disturbed, over half of them belonged to triacylglycerol (TG). Consistently, fasting significantly altered the expression of genes associated with fatty acid uptake, TG synthesis and metabolism, which were returned to baseline level after refeeding. In conclusion, these findings demonstrated that fasting induced liver shrinkage and the change of lipid profiling, especially TG accumulation in liver, while these effects can be reversed after refeeding.

Dual-Targeted Nanoparticles Hitchhiking on Lactobacillus rhamnosus Bacterial Ghosts to Alleviate Nonalcoholic Steatohepatitis

Oral nutritional interventions for nonalcoholic steatohepatitis (NASH) have garnered significant interest due to their potential benefits. Astaxanthin (AXT) has the potential to enhance liver function and act as an effective antioxidant for NASH intervention, but its application is limited by its stability and bioavailability. This study aims to develop dual-targeted AXT nanoparticles (AXT@TWG) for precise liver-targeted delivery by ″hitchhiking″ on Lactobacillus rhamnosus bacterial ghosts (LBGs) to effectively intervene in NASH. In vitro experiments demonstrated that AXT@TWG nanoparticles significantly reduced LPS-induced reactive oxygen species production and apoptosis while effectively alleviating lipid accumulation. In vivo experiments demonstrated that LBGs significantly enhanced the intestinal accumulation efficiency of AXT@TWG. Pharmacokinetic evaluations revealed that the efficiency of AXT@TWG@LBGs entering the bloodstream was approximately 2.7 times higher than that of AXT@TWG nanoparticles and their accumulation in the liver was about 1.3 times greater. AXT@TWG@LBGs effectively alleviated NASH by reducing triglycerides, free fatty acids, and malondialdehyde levels by 23.07, 65.32, and 21.42%, respectively, compared to the model group, thereby mitigating lipid accumulation and enhancing antioxidant capacity. Additionally, AXT@TWG@LBGs effectively reduced insulin resistance, lowered inflammatory cytokine levels, and corrected disturbances in lipid metabolism. Therefore, this study provides a potentially effective strategy for the treatment of NASH.

Tianjihuang compound alleviates aflatoxin B1-induced hepatic steatosis and fibrosis by targeting PPARα-TGF-β pathway in ducklings

Aflatoxin B1 (AFB1), a potent mycotoxin, poses a significant threat to the poultry industry, particularly affecting the health and growth of ducklings. The present study aimed to investigate the therapeutic effects and mechanisms of the Tianjihuang compound (HRS), a traditional Chinese medicine formulation, on AFB1-induced chronic toxicity in ducklings. Firstly, 30 ingredients, including neochlorogenic acid, kaempferol 3-alpha-D-galactoside, quercetin, hispidulin, caffeic acid, and myricetin, were identified from HRS with UPLC-MS/MS method. Then, over a 25-day experimental period, a total of 100 one-day-old Sichuan Sheldrakes were randomly divided into five groups: control, AFB1 model, and HRS high (4 g/kg), medium (2 g/kg), and low dosage (1 g/kg) groups. Results indicated that HRS effectively mitigated the negative impact on the productivity, reduced the levels of liver index, AST, ALT, and AST/ALT in serum, increased the levels of serum TP content, and obviously alleviated inflammatory cell infiltration, liver fibrosis, and liver steatosis induced by AFB1. Additionally, HRS enhanced the levels of GST, CAT, and T-AOC, and decreased the levels of MDA and AFB1-DNA, thereby alleviating oxidative stress and AFB1-DNA generation caused by AFB1. Transcriptome analysis revealed that HRS may improve liver injury in AFB1-chronically poisoned ducklings by regulating the ECM receptor interaction, fatty acid metabolism, cell adhesion molecules, TGF-β signaling pathway, and PPAR signaling pathway. Further RT-qPCR analysis revealed that HRS might downregulate the expression of ASCL4 gene by promoting the activation of PPARα, thereby inhibiting the activation of the TGF-β signaling pathway and improving liver steatosis and fibrosis caused by AFB1 in ducklings. In conclusion, the HRS exhibits hepatoprotective effects against AFB1-induced chronic toxicity in ducklings by restoring liver function, enhancing antioxidant capacity, and its mechanism of damage resistance may be related to the improvement of liver steatosis and fibrosis in ducklings by inhibiting the PPARα-TGF-β signaling pathway.

LIMA1 O-GlcNAcylation Promotes Hepatic Lipid Deposition through Inducing β-catenin-Regulated FASn Expression in Metabolic Dysfunction-Associated Steatotic Liver Disease

Hepatic lipid deposition is a key factor in progressing metabolic dysfunction-associated steatotic liver disease (MASLD). This study investigates the impact of the LIM domain and actin-binding protein 1 (LIMA1) on hepatic steatotic in MASLD and explore the underlying mechanisms. Increased levels of LIMA1 is observed in both serum and serum sEV of metabolic dysfunction-associated steatohepatitis (MASH) patients compared to healthy controls, with AUROC values of 0.76 and 0.86, respectively. Furthermore, increased LIMA1 O-GlcNAcylation is observed in mouse models of MASLD, and steatotic hepatocytes. Mechanistic studies revealed that steatosis upregulated Host cell factor 1 (HCF1) and O-GlcNAc transferase (OGT) expression, leading to catalyzed O-GlcNAcylation at the T662 site of LIMA1 and subsequent inhibition of its ubiquitin-dependent degradation. O-GlcNAcylation of LIMA1 enhances hepatocyte lipid deposition by activating β-catenin/FASn-associated signaling. Additionally, compared with their AAV8-TBG-LIMA1-WT counterparts, AAV8-TBG-LIMA1ΔT662 injection exhibited decreases in systemic insulin resistance, steatosis severity, inflammation and fibrosis in HFD-fed and CDAHFD-fed LIMA1 HKO (hepatocyte-specific knockout) mice. Moreover, LTH-sEV-mediated delivery of LIMA1 promoted MASLD progression by promoting hepatic stellate cell (HSC) activation. The findings suggest that serum sEV LIMA1 may be a potential noninvasive biomarker and therapeutic target for individuals with MASH.

Transcriptomic analysis reveals the mechanisms underlying the differential effects of caffeine, theophylline, and theobromine in regulating hepatic fat accumulation

Nonalcoholic fatty liver disease (NAFLD) is a common chronic liver disease, characterized by excessive fat accumulation in the liver. Caffeine, theophylline, and theobromine are the primary naturally occurring methylxanthines found in various foods and beverages such as coffee, tea, and chocolate. They exhibit diverse pharmacological effects. Although caffeine can inhibit hepatic fat accumulation in mice, the effects and regulatory mechanisms of theophylline and theobromine remain unclear. In this study, we observed that theophylline significantly reduced body weight and triglyceride levels and attenuated hepatic fat accumulation in mice fed a high-fat diet. Conversely, theobromine did not exhibit these effects. Transcriptomic results showed that caffeine and theophylline significantly activated the TNF signaling pathway in C2C12 myoblasts, induced p38MAPK expression and increased Il1b and Il6 secretion, but did not elevate Tnfa and Mcp1 expression. Notably, theobromine neither activated the TNF pathway nor significantly induced p38MAPK expression and Il1b and Il6 secretion. In conclusion, the differences in the regulating NAFLD activity of caffeine, theophylline, and theobromine-three structurally similar compounds used as food ingredients, may be attributed to their distinct regulation of the TNF signaling pathway.

AMPK agonist AICAR ameliorates maternal hepatic lipid metabolism disorder, inflammation, and fibrosis caused by PM2.5 exposure during pregnancy

Liver is an important target organ of ambient fine particulate matter (PM2.5). Numerous studies have shown that PM2.5 exposure can cause liver lipid metabolism disorders and other liver damage in mammals. However, the impact of PM2.5 on liver health during pregnancy, a sensitive life stage, remains understudied, and the underlying mechanisms are also unknown. Given the critical role of adenosine 5'-monophosphate activated protein kinase (AMPK) in regulating lipid metabolism and inflammation, we hypothesize that AMPK activation may mitigate maternal hepatic lipid metabolism disorders, reduce inflammation, and attenuate fibrosis induced by PM2.5 exposure during pregnancy. To test this hypothesis, pregnant C57BL/6 mice were randomly assigned to 4 groups: filtered air (FA) + NS (normal saline), PM2.5+NS, FA + AICAR (acadesine, an AMPK activator), and PM2.5+AICAR. PM2.5+NS and PM2.5+AICAR groups were continuously exposed to PM2.5 with a whole-body PM2.5 exposure chamber, while the other two groups were exposed to filtered air in the FA chamber. Simultaneously, the FA + AICAR and PM2.5+AICAR groups received intraperitoneal injections of the AMPK agonist AICAR (200 mg/kg∙bw per day) from gestational day 13 (GD13) to GD17, while mice in the FA + NS and PM2.5+NS groups were administered normal saline injection. We found that gestational PM2.5 exposure induced dyslipidemia in pregnant mice, which was alleviated by AICAR treatment. Histopathological analysis showed that the exposure to PM2.5 during pregnancy induced hepatic lipid deposition and fibrosis in pregnant mice, and biochemical assays revealed that hepatic triglyceride and cholesterol levels were also significantly increased in pregnant mice after exposure to PM2.5, whereas the AICAR treatment ameliorated hepatic lipid deposition and fibrosis induced by the exposure to PM2.5 during pregnancy. Furthermore, PM2.5 exposure during pregnancy disrupted the expression of key genes and proteins associated with hepatic lipid synthesis, cholesterol synthesis, inflammation, and fibrosis, while treatment with AICAR mitigated these effects. These findings demonstrated that AMPK activation ameliorates hepatic lipid metabolism disorders, reduces inflammation, and attenuates fibrosis caused by PM2.5 exposure in mice during pregnancy. AMPK may be a target of action for maternal liver injury induced by PM2.5 exposure during pregnancy.

Pollutants in Microenvironmental Cellular Interactions During Liver Inflammation Cancer Transition and the Application of Multi-Omics Analysis

This study categorizes pollutant-induced inflammation-cancer transition into three stages: non-alcoholic fatty liver disease (NAFLD), liver fibrosis, and hepatocellular carcinoma (HCC). It systematically reveals the temporal heterogeneity of pollutant-induced liver damage. The findings indicate that pollutants not only directly damage hepatocytes but also modulate key cells in the immune microenvironment, such as hepatic stellate cells (HSCs) and Kupffer cells, thereby amplifying inflammatory and fibrotic responses, ultimately accelerating the progression of HCC. Mechanistically, in the early stage (NAFLD), pollutants primarily cause hepatocyte injury through oxidative stress and lipid metabolism dysregulation. During the fibrosis stage, pollutants promote liver fibrosis by inducing extracellular matrix accumulation, while in the HCC stage, they drive tumorigenesis via activation of the Wnt/β-catenin pathway and p53 inactivation. Through multi-omics analyses, this study identifies critical pathogenic molecules and signaling pathways regulated by pollutants, providing new insights into their pathogenic mechanisms, potential biomarkers, and therapeutic targets. These findings offer valuable guidance for the development of diagnostic and therapeutic strategies for liver diseases and the formulation of environmental health risk prevention measures.

Exploring Extracellular Vesicles: A Novel Approach in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) represents an increasing public health concern. The underlying pathophysiological mechanisms of NAFLD remains unclear, and as a result, there is currently no specific therapy for this condition. However, recent studies focus on extracellular vesicles (EVs) as a novelty in their role in cellular communication. An imbalance in the gut microbiota composition may contribute to the progression of NAFLD, making the gut-liver axis a promising target for therapeutic strategies. This review aims to provide a comprehensive overview of EVs in NAFLD. Additionally, exosome-like nanovesicles derived from plants (PELNs) and probiotics-derived extracellular vesicles (postbiotics) have demonstrated the potential to re-establish intestinal equilibrium and modulate gut microbiota, thus offering the potential to alleviate NAFLD via the gut-liver axis. Further research is needed using multiple omics approaches to comprehensively characterize the cargo including protein, metabolites, genetic material packaged, and biological activities of extracellular vesicles derived from diverse microbes and plants.

Integrated lipidomic and transcriptomics to explore the effects of ethyl acetate extract of Herpetospermum pedunculosum on nonalcoholic fatty liver disease in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Herpetospermum pedunculosum (Ser.) C.B. Clarke (HP), a traditional Tibetan medicine used to treat hepatobiliary diseases, was confirmed that lignans-enriched ethyl acetate extract of HP (EAHP) could alleviate the hepatic injury by modern pharmacological evidence. However, the effects and potential mechanisms of EAHP against nonalcoholic fatty liver disease (NAFLD) are still unknown.

AIM OF THE STUDY

To reveal the effects of EAHP on NAFLD and explore the potential mechanisms from the perspective of lipidomics and transcriptomics.

MATERIALS AND METHODS

UPLC‒Q-TOF‒MS analysis was carried out to investigate the chemical components of EAHP. A Choline-deficient, L-amino acid defined, high fat diet (CDAHFD) was used to establish a NAFLD mouse model. The anti-NAFLD effects of various dosages of EAHP were evaluated by biochemical indexes and histological analysis. Hepatic lipidomic and transcriptomic analysis and multiple bioinformatics methods were used to screen biomarkers and signaling pathways. The levels of the corresponding genes were verified by qPCR.

RESULTS

36 kinds of compounds were identified by UPLC‒Q-TOF‒MS analysis. Oral treatment with EAHP significantly decrease the liver index and the levels of ALT and AST in the serum. The measurements lipid content and Oil Red O staining results suggested that EAHP ameliorated lipid metabolism disorders by reducing the content of TG and LDL-C, increasing HDL-C in the liver. H&E staining and ELISA revealed that EAHP restored hepatic inflammatory infiltration and decrease the levels of IL-1β, IL-6, TNF-α, and increase IL-10 in the serum. Lipidomic analysis showed that EAHP could regulate CDAHFD-induced lipid metabolic disorder. The different lipid metabolites included TG, phosphatidyl choline (PC), diacylglycerol (DG), phosphatidylethanolamine (PE), phosphatidylinositol (PI), ceramide (Cer). Transcriptomic analysis revealed that Bmp8b, Nbl1, Rgma, Sphk1, Thbs1, and Ugt8a were important regulators, which were associated with TGF-β signaling pathway and sphingolipid metabolism. The expressions of above genes detected by were qPCR consistent with transcriptomic data.

CONCLUSIONS

The ameliorative effects of EAHP on NAFLD are potentially attributable to the regulation of sphingolipid metabolism and TGF-β signaling pathway, etc., which results in abnormal hepatic lipid metabolism and inflammatory response.

Lipidomics reveals the lipid-lowering and hepatoprotective effects of Celosia Semen on high-fat diet-induced NAFLD mice

ETHNOPHARMACOLOGICAL RELEVANCE

Celosia Semen (CS) serves as a traditional Chinese medicine (TCM) for promoting liver health and enhancing vision, with extensive clinical applications. Triterpenoid saponins represent the primary active components of CS, with the highest concentration of Celosin I (CI) detected. The urgent need for effective NAFLD treatments motivated us assess the beneficial effects of total saponins from CS (TSCS) and CI.

AIMS OF THE STUDY

To investigate the therapeutic effects of TSCS and CI on NAFLD and its underlying molecular mechanisms.

MATERIALS AND METHODS

The impact of TSCS and CI on NAFLD was evaluated through in vitro and in vivo methodologies, utilizing high-fat diet (HFD) and palmitic acid/oleic acid modeling on C57BL/6J mice and AML12 cells, respectively. Biochemical analysis, H&E and Oil red O staining were used to characterize the lipid-lowering and hepatoprotective activities of TSCS and CI. Lipidomics discerned the impact of TSCS and CI interventions on liver lipid composition, distribution and alteration in NFALD mice. RT-qPCR and western blotting detected the influence of TSCS and CI on genes linked to de novo lipogenesis, fat calculation uptake, oxidation and esterification. The docking analysis anticipated the interaction of six major triterpenoid saponins within TSCS with SREBP1.

RESULTS

TSCS and CI markedly diminished lipid accumulation induced by high fat both in vivo and in vitro. TSCS and CI also mitigated hepatic steatosis and liver injury induced by HFD through the reduction of TC, TG, FAs, ALT, and AST, even at minimal dose of 25 mg/kg. Lipidomics indicated that TSCS and CI had the potential to modulate the lipid metabolism network, rectify lipid metabolic dysregulation induced by NAFLD, decrease the levels of harmful lipids, and elevate the levels of advantageous lipids. Furthermore, TSCS and CI exhibited a strong affinity to SREBP1, thereby might directly influence the expression of SREBP1 and a cascade of essential enzymes involved in de novo lipogenesis, and finally resulting in a diminished synthesis of novel lipids.

CONCLUSION

TSCS and CI were confirmed firstly as key active components of CS in amending hepatic steatosis and mitigate liver damage in NAFLD, outlining the preliminary mechanism. They warrant further exploration as drug candidates for NAFLD treatment, especially in light of the current shortage of medications and limited therapeutic options.

MAP17 is a Novel NASH Progression Biomarker Associated with Macrophage Infiltration, Immunotherapy Response, and Oxidative Stress

Background

Nonalcoholic steatohepatitis (NASH) has recently garnered increased attention due to immune infiltration. However, the role of membrane-associated protein 17 (MAP17) in NASH remains unclear, which prompted this study to explore its relationship with immune infiltration and its regulatory mechanisms.

Methods

We employed weighted correlation network analysis (WGCNA) to construct a gene co-expression network aimed at identifying key genes associated with NASH progression. Our further analyses included differential expression evaluation, protein-protein interaction (PPI) network analysis, and Venn diagram analysis to discover novel targets. The CIBERSORT algorithm assessed the correlation between MAP17 and immune cell infiltration within the tumor microenvironment (TME), while the TIDE algorithm predicted responses to immunotherapy. Additionally, we conducted gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and gene set enrichment analysis (GSEA) to elucidate the mechanisms by which MAP17 operates. The expression of MAP17 was validated using liver tissues obtained from NASH patients and mice with diet-induced NASH or CCl4-induced liver fibrosis.

Results

Our findings identified MAP17 as a novel target in the progression of NASH. Correlation analyses demonstrated a positive association between MAP17 and M1 macrophage infiltration, as well as a negative association with M2 infiltration. TIDE results positioned MAP17 as a potential biomarker for predicting responses to immune checkpoint blockade. Mechanistic studies revealed that MAP17 induced oxidative stress, which subsequently activated the p53, PI3K-AKT, and Wnt signaling pathways. Validation analyses confirmed that MAP17 levels significantly increased in liver tissues of mice with diet-induced NASH or CCl4-induced liver fibrosis, as well as in NASH patients.

Conclusion

MAP17 is a novel biomarker linked to macrophage infiltration and immunotherapy responses in NASH patients. The oxidative stress induced by MAP17 activates the p53, PI3K-AKT, and Wnt pathways, all of which contribute to the progression of NASH.

The plasma lipidome varies with the severity of metabolic dysfunction-associated steatotic liver disease

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD) is closely associated with many aspects of disturbed metabolic health. MASLD encompasses a wide spectrum of liver diseases, ranging from isolated steatosis to metabolic dysfunction-associated steatohepatitis (MASH), up to fibrosis, cirrhosis, and ultimately hepatocellular carcinoma. Limited noninvasive diagnostic tools are currently available to distinguish the various stages of MASLD and as such liver biopsy remains the gold standard for MASLD diagnostics. We aimed to explore whether the plasma lipidome and its variations can serve as a biomarker for MASLD stages.

METHODS

We investigated the plasma lipidome of 7 MASLD-free subjects and 32 individuals with MASLD, of whom 11 had MASH based on biopsy scoring.

RESULTS

Compared with the MASLD-free subjects, individuals with MASLD had higher plasma concentrations of sphingolipids, glycerolipids, and glycerophospholipids. Only plasma concentrations of ceramide-1-phosphate C1P(d45:1) and phosphatidylcholine PC(O-36:3), PC(O-38:3), and PC(36:2) differed significantly between presence of MASH in individuals with MASLD. Of these lipids, the first three have a very low relative plasma abundance, thus only PC(36:2) might serve as a biomarker with higher plasma concentrations in MASLD individuals without MASH compared to those with MASH.

CONCLUSIONS

Plasma lipids hold promise as biomarkers of MASLD stages, whereas plasma PC(36:2) concentrations would be able to distinguish individuals with MASH from those with MASLD without MASH.

Metabolomics at the cutting edge of risk prediction of MASLD

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a major public health threat globally. Management of patients afflicted with MASLD and research in this domain are limited by the lack of robust well-established non-invasive biomarkers for diagnosis, prognostication, and monitoring. The circulating metabolome reflects both the systemic metabo-inflammatory milieu and changes in the liver in affected individuals. In this review we summarize the available literature on changes in the different components of the metabolome in MASLD with a focus on changes that are linked to the presence of underlying steatohepatitis, severity of disease activity, and fibrosis stage. We further summarize the existing literature around biomarker panels that are derived from interrogation of the metabolome. Their relevance to disease biology and utility in practice are also discussed. We further highlight potential direction for future studies particularly to ensure they are fit for purpose and suitable for widespread use.

PDCD4 deficiency in hepatocytes exacerbates nonalcoholic steatohepatitis through enhanced MHC class II transactivator expression

Nonalcoholic steatohepatitis (NASH) is a primary cause of liver cirrhosis and hepatocellular carcinoma, presenting a significant and unmet medical challenge. The necessity to investigate the molecular mechanisms underlying NASH is highlighted by the observed decrease in programmed cell death 4 (PDCD4) expression in NASH patients, suggesting that PDCD4 may play a protective role in maintaining liver health. In this study, we identify PDCD4 as a natural inhibitor of NASH development in mice. The absence of PDCD4 leads to the spontaneous progression of NASH. Notably, PDCD4-deficient hepatocytes display elevated major histocompatibility complex class II (MHCII) expression due to CIITA activation, indicating that PCDC4 prevents the abnormal transformation of hepatocytes into antigen-presenting cells (APCs). Cell co-culture experiments reveal that hepatocytes lacking PDCD4, which resemble APCs, can directly activate CD4+ T cells by presenting multiple peptides, resulting in the release of inflammatory factors. Additionally, both cellular and animal studies show that CIITA promotes lipid accumulation in hepatocytes and exacerbates NASH progression. In summary, our findings reveal a novel role of PDCD4 in regulating CIITA and MHCII expression during NASH development, offering new therapeutic approaches for NASH treatment.

Metabolomics study of dietary Pleurotus eryngii β-type glycosidic polysaccharide on colitis induced by dextran sodium sulfate in mice - Exploration for the potential metabolic indicators in urine and serum

Pleurotus eryngii, an edible mushroom recognized for its potent polysaccharides, demonstrates significant regulatory effects on metabolic processes. β-glucan (WPEP) derived from P. eryngii has been noted for its therapeutic potential, exhibiting notable benefits in alleviating colonic inflammation and restructuring gut microbiota in mice treated with dextran sodium sulfate (DSS). This study focuses on utilizing DSS-induced colitis mice to explore the efficacy and underlying mechanisms of WPEP in ameliorating colitis, employing a metabolomics approach analyzing urine and serum. The findings reveal that WPEP administration effectively regulates metabolic imbalances in DSS mice, impacting purine metabolism, pentose and glucuronic acid interconversion, amino acid metabolism, primary bile acid biosynthesis, citric acid cycle, and lipid metabolism. Furthermore, WPEP demonstrates a capacity to modulate colitis by regulating diverse metabolic pathways, consequently influencing intestinal barrier integrity, motility, inflammation, oxidative stress, and immunity. These insights suggest that WPEP is a promising food component for managing inflammatory bowel diseases.

Pathogenesis and research progress of nonalcoholic fatty liver disease/nonalcoholic steatohepatitis

In this editorial, we comment on the article by Mei et al. Nonalcoholic steatohepatitis (NASH) is a severe inflammatory subtype of nonalcoholic fatty liver disease (NAFLD) with pathological features including steatosis, hepatocellular damage, and varying degrees of fibrosis. With the epidemic of metabolic diseases and obesity, the prevalence of NAFLD in China has increased, and it is now similar to that in developed countries; thus, NAFLD has become a major chronic liver disease in China. Human epidemiological data suggest that estrogen has a protective effect on NASH in premenopausal women and that sex hormones influence the development of liver disease. This review focuses on the pathogenesis, treatment, and relationship between NASH and other diseases as well as on the relationship between NASH and sex hormone metabolism, with the aim of providing new strategies for the treatment of NASH.

Pathogenesis and research progress of nonalcoholic fatty liver disease/nonalcoholic steatohepatitis

In this editorial, we comment on the article by Mei et al. Nonalcoholic steatohepatitis (NASH) is a severe inflammatory subtype of nonalcoholic fatty liver disease (NAFLD) with pathological features including steatosis, hepatocellular damage, and varying degrees of fibrosis. With the epidemic of metabolic diseases and obesity, the prevalence of NAFLD in China has increased, and it is now similar to that in developed countries; thus, NAFLD has become a major chronic liver disease in China. Human epidemiological data suggest that estrogen has a protective effect on NASH in premenopausal women and that sex hormones influence the development of liver disease. This review focuses on the pathogenesis, treatment, and relationship between NASH and other diseases as well as on the relationship between NASH and sex hormone metabolism, with the aim of providing new strategies for the treatment of NASH.

The association between the non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio and non-alcoholic fatty liver disease in US adults: a cross-sectional study

The ratio of non-high-density lipoprotein cholesterol (non-HDL-C) to HDL-C (NHHR) is a novel lipid parameter used to assess the risk of cardiovascular disease. Previous studies have demonstrated an association between the NHHR and risk of non-alcoholic fatty liver disease (NAFLD). Owing to the lack of research exploring this relationship in specific populations, this study aimed to determine the potential link between the NHHR and risk of NAFLD among American adults in the United States. Data were retrieved from the National Health and Nutrition Examination Survey (NHANES) spanning 2017-2020. After excluding individuals with other liver diseases, alcohol abuse, and missing lipid data, a total of 6809 eligible adults were included for analysis. The NHHR was calculated as the ratio of (non-HDL-C) to HDL-C, while NAFLD was identified by liver steatosis detected by transient elastography. Multivariable weighted logistic regression models and restricted cubic spline (RCS) models were employed to investigate the relationship between the NHHR and risk of NAFLD. Subgroup and sensitivity analyses were also conducted to test the robustness of the results. As the NHHR increased, the prevalence of NAFLD rose progressively (5.88% vs. 8.75% vs. 12.24% vs. 15.77%, p < 0.001). In the overall population, after adjusting for confounding factors, each unit increase in the NHHR was associated with a 25% increase in NAFLD risk (OR = 1.25, 95% CI: 1.03-1.53, p = 0.0372). When the NHHR was analyzed as a categorical variable (quartiles), participants in the highest quartile had a significantly higher risk of NAFLD than those in the lowest quartile (OR = 2.6, 95% CI: 1.75-3.85, p = 0.009). RCS analysis further indicated a nonlinear dose-response relationship between the NHHR and risk of NAFLD (p non-linearity < 0.0001). This association remained significant in both subgroup and sensitivity analyses. This study confirmed that the NHHR, particularly at higher levels, was an independent risk factor for NAFLD. As a comprehensive lipid indicator, the NHHR had the potential to predict NAFLD risk. These findings provided new insights for the prevention and clinical management of NAFLD.

Tanshinone IIA Inhibits the Endoplasmic Reticulum Stress-Induced Unfolded Protein Response by Activating the PPARα/FGF21 Axis to Ameliorate Nonalcoholic Steatohepatitis

Nonalcoholic steatohepatitis (NASH) is a critical stage in the progression of nonalcoholic fatty liver disease (NAFLD). Tanshinone IIA (TIIA) is a tanshinone extracted from Salvia miltiorrhiza; due to its powerful anti-inflammatory and antioxidant biological activities, it is commonly used for treating cardiovascular and hepatic diseases. A NASH model was established by feeding mice a methionine and choline-deficient (MCD) diet. Liver surface microblood flow scanning, biochemical examination, histopathological examination, cytokine analysis through ELISA, lipidomic analysis, transcriptomic analysis, and Western blot analysis were used to evaluate the therapeutic effect and mechanism of TIIA on NASH. The results showed that TIIA effectively reduced lipid accumulation, fibrosis, and inflammation and alleviated endoplasmic reticulum (ER) stress. Lipidomic analysis revealed that TIIA normalized liver phospholipid metabolism in NASH mice. A KEGG analysis of the transcriptome revealed that TIIA exerted its effect by regulating the PPAR signalling pathway, protein processing in the ER, and the NOD-like receptor signalling pathway. These results suggest that TIIA alleviates NASH by activating the PPARα/FGF21 axis to negatively regulate the ER stress-induced unfolded protein response (UPR).

Lipid Nanoparticle-Mediated Delivery of CRISPR-Cas9 Against Rubicon Ameliorates NAFLD by Modulating CD36 Along with Glycerophospholipid Metabolism

Non-alcoholic fatty liver disease (NAFLD) is a prominent cause of various chronic metabolic hepatic diseases with limited therapeutics. Rubicon, an essential regulator in lysosomal degradation, is reported to exacerbate hepatic steatosis in NAFLD mice and patients, indicating its probability of being a therapeutic target for NAFLD treatment. In this study, the therapeutic potential of Rubicon blockage is investigated. Lipid nanoparticles carrying Rubicon-specific CRISPR-Cas9 components exhibited liver accumulation, cell internalization, and Rubicon knockdown. A single administration of the nanoparticles results in attenuated lipid deposition and hepatic steatosis, with lower circulating lipid levels and decreased adipocyte size in NAFLD mice. Furthermore, the increase of phosphatidylcholine and phosphatidylethanolamine levels can be observed in the NAFLD mice livers after Rubicon silencing, along with regulatory effects on metabolism-related genes such as CD36, Gpcpd1, Chka, and Lpin2. The results indicate that knockdown of Rubicon improves glycerophospholipid metabolism and thereby ameliorates the NAFLD progression, which provides a potential strategy for NAFLD therapy via the restoration of Rubicon.

Examining the Pathogenesis of MAFLD and the Medicinal Properties of Natural Products from a Metabolic Perspective

Metabolic-associated fatty liver disease (MAFLD), characterized primarily by hepatic steatosis, has become the most prevalent liver disease worldwide, affecting approximately two-fifths of the global population. The pathogenesis of MAFLD is extremely complex, and to date, there are no approved therapeutic drugs for clinical use. Considerable evidence indicates that various metabolic disorders play a pivotal role in the progression of MAFLD, including lipids, carbohydrates, amino acids, and micronutrients. In recent years, the medicinal properties of natural products have attracted widespread attention, and numerous studies have reported their efficacy in ameliorating metabolic disorders and subsequently alleviating MAFLD. This review aims to summarize the metabolic-associated pathological mechanisms of MAFLD, as well as the natural products that regulate metabolic pathways to alleviate MAFLD.

Indoleamine 2,3-dioxygenase 1-mediated iron metabolism in macrophages contributes to lipid deposition in nonalcoholic steatohepatitis

BACKGROUND

Non-alcoholic steatohepatitis (NASH) is a rapidly progressing chronic liver disease of global significance. However, the underlying mechanisms responsible for NASH remain unknown. Indoleamine 2,3-dioxygenase 1 (IDO1) has been recognized as essential factor in immune response and metabolic regulation. Here we aimed to investigate the functions and mechanisms of the IDO1 in macrophages on hepatic lipid deposition and iron metabolism in NASH.

METHODS

The effect of IDO1 in NASH was evaluated by WT and IDO1-/- mice model fed with methionine/choline-deficient (MCD) diet in vivo. Macrophages scavenger clodronate liposomes (CL) and overexpressing of IDO1 in macrophages by virus were employed as well. Lipid deposition was assessed through pathological examination and lipid droplet staining, while iron levels were measured using an iron assay kit and western blotting. Primary hepatocytes and bone marrow-derived macrophages were treated with oleic acid/palmitic acid (OA/PA) to assess IDO1 expression via Oil Red O staining and immunofluorescence staining in vitro.

RESULTS

Pathological images demonstrated that the increase of IDO1 exacerbated lipid accumulation in the livers of mice with MCD diet, while reduction of iron accumulation was observed in the liver and the serum of MCD-fed mice. Scavenging of macrophages effectively mitigated both lipid and iron accumulation. In addition, the deficiency of IDO1 in macrophages significantly mitigated lipid accumulation and iron overload in hepatic parenchymal cells. Finally, lentivirus-mediated overexpression of IDO1 in liver macrophages exacerbated hepatic steatosis and iron deposition in NASH.

CONCLUSIONS

Our results demonstrated that effective inhibition of IDO1 expression in macrophages in NASH alleviated hepatic parenchymal cell lipid accumulation and iron deposition, which provided new insights for the future treatment of NASH.

The role of novel adipokines and adipose-derived extracellular vesicles (ADEVs): Connections and interactions in liver diseases

Adipose tissues (AT) are an important endocrine organ that secretes various functional adipokines, peptides, non-coding RNAs, and acts on AT themselves or other distant tissues or organs through autocrine, paracrine, or endocrine manners. An accumulating body of evidence has suggested that many adipokines play an important role in liver metabolism. Besides the traditional adipokines such as adiponectin and leptin, many novel adipokines have recently been identified to have regulatory effects on the liver. Additionally, AT can produce extracellular vesicles (EVs) that act on peripheral tissues. However, under pathological conditions, such as obesity and diabetes, dysregulation of adipokines is associated with functional changes in AT, which may cause liver diseases. In this review, we focus on the newly discovered adipokines and EVs secreted by AT and highlight their actions on the liver under the context of obesity, nonalcoholic fatty liver diseases (NAFLD), and some other liver diseases. Clarifying the action of adipokines and adipose tissue-derived EVs on the liver would help to identify novel therapeutic targets or biomarkers for metabolic diseases.

Molecular mechanisms in MASLD/MASH-related HCC

Liver cancer is the third leading cause of cancer-related deaths and ranks as the sixth most prevalent cancer type globally. NAFLD or metabolic dysfunction-associated steatotic liver disease, and its more severe manifestation, NASH or metabolic dysfunction-associated steatohepatitis (MASH), pose a significant global health concern, affecting approximately 20%-25% of the population. The increased prevalence of metabolic dysfunction-associated steatotic liver disease and MASH is parallel to the increasing rates of obesity-associated metabolic diseases, including type 2 diabetes, insulin resistance, and fatty liver diseases. MASH can progress to MASH-related HCC (MASH-HCC) in about 2% of cases each year, influenced by various factors such as genetic mutations, carcinogen exposure, immune microenvironment, and microbiome. MASH-HCC exhibits distinct molecular and immune characteristics compared to other causes of HCC and affects both men and women equally. The management of early to intermediate-stage MASH-HCC typically involves surgery and locoregional therapies, while advanced HCC is treated with systemic therapies, including anti-angiogenic therapies and immune checkpoint inhibitors. In this comprehensive review, we consolidate previous research findings while also providing the most current insights into the intricate molecular processes underlying MASH-HCC development. We delve into MASH-HCC-associated genetic variations and somatic mutations, disease progression and research models, multiomics analysis, immunological and microenvironmental impacts, and discuss targeted/combined therapies to overcome immune evasion and the biomarkers to recognize treatment responders. By furthering our comprehension of the molecular mechanisms underlying MASH-HCC, our goal is to catalyze the advancement of more potent treatment strategies, ultimately leading to enhanced patient outcomes.

Molecular Mechanisms of Curcumin in the Pathogenesis of Metabolic Dysfunction Associated Steatotic Liver Disease

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a multifactorial condition characterized by insulin resistance, oxidative stress, chronic low-grade inflammation, and sometimes fibrosis. To date, no effective pharmacological therapy has been approved for the treatment of metabolic-associated steatohepatitis (MASH), the progressive form of MASLD. Recently, numerous in vitro and in vivo studies have described the efficacy of nutraceutical compounds in the diet has been tested. Among them, curcumin is the most widely used polyphenol in the diet showing potent anti-inflammatory and antifibrotic activities. This review aims to summarize the most important basic studies (in vitro and animal models studies), describing the molecular mechanisms by which curcumin acts in the context of MASLD, providing the rationale for its effective translational use in humans.

Integration of Transcriptomics and Lipidomics Profiling to Reveal the Therapeutic Mechanism Underlying Ramulus mori (Sangzhi) Alkaloids for the Treatment of Liver Lipid Metabolic Disturbance in High-Fat-Diet/Streptozotocin-Induced Diabetic Mice

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disorder, with a global prevalence of 25%. Currently, there remains no approved therapy. Ramulus mori (Sangzhi) alkaloids (SZ-As), a novel natural medicine, have achieved comprehensive benefits in the treatment of type 2 diabetes; however, few studies have focused on its role in ameliorating hepatic lipid metabolic disturbance. Herein, the therapeutic effect and mechanism of SZ-As on a high-fat diet (HFD) combined with streptozotocin (STZ)-induced NAFLD mice were investigated via incorporating transcriptomics and lipidomics. SZ-As reduced body weight and hepatic lipid levels, restored pathological alternation and converted the blood biochemistry perturbations. SZ-A treatment also remarkedly inhibited lipogenesis and enhanced lipolysis, fatty acid oxidation and thermogenesis. Transcriptomics analysis confirmed that SZ-As mainly altered fatty acid oxidative metabolism and the TNF signaling pathway. SZ-As were further demonstrated to downregulate inflammatory factors and effectively ameliorate hepatic inflammation. Lipidomics analysis also suggested that SZ-As affected differential lipids including triglyceride (TG) and phosphatidylcholine (PC) expression, and the main metabolic pathways included glycerophospholipid, sphingomyelins and choline metabolism. Collectively, combined with transcriptomics and metabolomics data, it is suggested that SZ-As exert their therapeutic effect on NAFLD possibly through regulating lipid metabolism pathways (glycerophospholipid metabolism and choline metabolism) and increasing levels of PC and lysophosphatidylcholine (LPC) metabolites. This study provides the basis for more widespread clinical applications of SZ-As.

Bioinformatics analysis to reveal the potential comorbidity mechanism in psoriasis and nonalcoholic steatohepatitis

PURPOSE

An increasing amount of evidence suggests that psoriasis and nonalcoholic steatohepatitis (NASH) may occur simultaneously, whereas the underlying mechanisms remain unclear. Our research aims to explore the potential comorbidity mechanism in psoriasis and nonalcoholic steatohepatitis.

MATERIALS AND METHODS

The expression profiles of psoriasis (GSE30999, GSE13355) and NASH (GSE24807, GSE17470) were downloaded from GEO datasets. Next, common differently expressed genes (DEGs) of psoriasis and NASH were investigated. Then, GO and KEGG enrichment, protein interaction network (PPI) construction, and hub gene identification for DEGs were performed. Finally, immune cells expression, target genes predicted by common miRNAs, and transcription factors interaction analysis for hub genes were carried out.

RESULTS

Twenty DEGs were identified in totally. GO analysis revealed response to the virus was the most enriched term, and hepatitis C and coronavirus disease-COVID-19 infection-associated pathways were mainly enriched in KEGG. A total of eight hub genes were collected, including IFIT1, IFIT3, OAS1, HPGDS, IFI27, IFI44, CXCL10, IRF9, and 11 TFs were predicted. Then, neutrophils and monocytes were identified as immune cells that express the most hub genes. Moreover, five common miRNAs for psoriasis and NASH and one common miRNAs (hsa-miR-1305)-mRNAs (CHL1, MBNL2) network were presented.

CONCLUSION

CHL1 and MBNL2 may participate in the process of psoriasis and NASH via regulating hsa-miR-1305, and together with eight hub genes may be potential therapeutic targets for future treatment for the co-occurrence of these two diseases. This comprehensive bioinformatic analysis provides new insights on molecular pathogenesis and identification of potential therapeutic targets for the co-occurrence of them.