The gut microbiota is an indispensable symbiotic entity within the human holobiont, serving as a critical regulator of host lipid metabolism homeostasis. Therefore, it has emerged as a central subject of research in the pathophysiology of metabolic disorders. This microbial consortium orchestrates key aspects of host lipid dynamics-including absorption, metabolism, and storage-through multifaceted mechanisms such as the enzymatic processing of dietary polysaccharides, the facilitation of long-chain fatty acid uptake by intestinal epithelial cells (IECs), and the bidirectional modulation of adipose tissue functionality. Mounting evidence underscores that gut microbiota-derived metabolites not only directly mediate canonical lipid metabolic pathways but also interface with host immune pathways, epigenetic machinery, and circadian regulatory systems, thereby establishing an intricate crosstalk that coordinates systemic metabolic outputs. Perturbations in microbial composition (dysbiosis) drive pathological disruptions to lipid homeostasis, serving as a pathogenic driver for conditions such as obesity, hyperlipidemia, and non-alcoholic fatty liver disease (NAFLD). This review systematically examines the emerging mechanistic insights into the gut microbiota-mediated regulation of intestinal lipid metabolism, while it elucidates its translational implications for understanding metabolic disease pathogenesis and developing targeted therapies.
Humans ; Gastrointestinal Microbiome/physiology* ; Lipid Metabolism ; Animals ; Intestinal Mucosa/metabolism* ; Homeostasis ; Dysbiosis ; Obesity/metabolism* ; Intestines/microbiology* ; Non-alcoholic Fatty Liver Disease/metabolism* ; Metabolic Diseases/metabolism*

Nuclear factor erythroid 2-related factor 2 (Nrf2) is an intracellular transcription factor that helps protect against oxidative stress in different types of cells under pathological conditions. Mitochondria are vital organelles that function in diverse metabolic processes in the body, including redox reactions, lipid metabolism, and cell death. Mitophagy, a specific form of autophagy for damaged mitochondria, plays a critical role in the pathophysiology of liver diseases. In this review, we explain in detail the roles of the Nrf2 signaling pathway and mitophagy, and the relationship between them, in various hepatic diseases (nonalcoholic fatty liver disease, viral hepatitis, alcoholic liver disease, drug-induced liver injury, autoimmune hepatitis, hepatic ischemia‒reperfusion injury, and liver cancer). We also offer some potential insights and treatments relevant to clinical applications.
Humans ; NF-E2-Related Factor 2/metabolism* ; Mitophagy/physiology* ; Kelch-Like ECH-Associated Protein 1/metabolism* ; Signal Transduction ; Liver Diseases/etiology* ; Animals ; Oxidative Stress ; Mitochondria/metabolism* ; Non-alcoholic Fatty Liver Disease ; Liver Neoplasms

OBJECTIVES: To investigate the active ingredients in Hedyotis diffusa-Scutellaria barbata D. Don and the main biological processes and signaling pathways mediating their inhibitory effect on primary hepatocellular carcinoma (HCC). METHODS: The core intersecting genes of HCC and the two drugs were screened from TCMSP, Uniport, Genecards, and String databases using Cytoscape software, and GO and KEGG enrichment analyses of the intersecting genes were conducted. Molecular docking between the active ingredients of the drugs and the core genes was carried out using Pubcham, RCSB and Autoduckto to identify the active ingredients with the highest binding energy, whose inhibitory effect on HepG2 cells was verifies using CCK-8 assay, flow cytometry and Western blotting. RESULTS: TP53 and ESR1 were identified as the core genes of HCC and the two drugs. GO and KEGG analyses showed that the two genes were mainly involved in regulation of apoptotic signaling pathway, cell population proliferation, methane raft, and protein kinase activity, and participated in the signaling pathways of apoptosis, proteoglycans in cancer, PI3K Akt signaling pathway, and hepatitis B. Molecular docking studies showed that the active ingredients of the drugs could be docked with TP53 and ESR1 genes under natural conditions, and ursolic acid had the highest binding energy to ESR1 (-4.98 kcal/mol). The results of CCK-8 assay, flow cytometry and Western blotting all demonstrated significant inhibitory effect of ursolic acid on HepG2 cells. CONCLUSIONS The inhibitory effect of Hedyotis diffusa-scutellariae barbatae on HCC is mediated by multiple active ingredients in the two drugs.
Humans ; Molecular Docking Simulation ; Liver Neoplasms/drug therapy* ; Hep G2 Cells ; Network Pharmacology ; Carcinoma, Hepatocellular/drug therapy* ; Hedyotis/chemistry* ; Signal Transduction/drug effects* ; Cell Proliferation/drug effects* ; Tumor Suppressor Protein p53/metabolism* ; Apoptosis/drug effects* ; Estrogen Receptor alpha/metabolism* ; Drugs, Chinese Herbal/pharmacology*

OBJECTIVES: To investigate the regulatory role of nucleotide-bound oligomerized domain-like receptor containing pyrin-domain protein 6 (NLRP6) in liver lipid metabolism and non-alcoholic fatty liver disease (NAFLD). METHODS: Mouse models with high-fat diet (HFD) feeding for 16 weeks (n=6) or with methionine choline-deficient diet (MCD) feeding for 8 weeks (n=6) were examined for the development of NAFLD using HE and oil red O staining, and hepatic expressions of NLRP6 were detected with RT-qPCR, Western blotting, and immunohistochemical staining. Cultured human hepatocytes (LO2 cells) with adenovirus-mediated NLRP6 overexpression or knock-down were treated with palmitic acid (PA) in the presence or absence of compound C (an AMPK inhibitor), and the changes in cellular lipid metabolism were examined by measuring triglyceride, ATP and β-hydroxybutyrate levels and using oil red staining, RT-qPCR, and Western blotting. RESULTS: HFD and MCD feeding both resulted in the development of NAFLD in mice, which showed significantly decreased NLRP6 expression in the liver. In PA-treated LO2 cells, NLRP6 overexpression significantly decreased cellular TG content and lipid deposition, while NLRP6 knockdown caused the opposite effects. NLRP6 overexpression in PA-treated LO2 cells also increased mRNA and protein expressions of PGC1A and CPT1A, levels of ATP and β-hydroxybutyrate, and the phosphorylation level of AMPK pathway; the oxidative decomposition of lipids induced by Ad-NLRP6 was inhibited by the use of AMPK inhibitors. CONCLUSIONS NLRP6 overexpression promotes lipid oxidation and decomposition through AMPK/CPT1A/PGC1A to alleviate lipid deposition in hepatocytes.
Non-alcoholic Fatty Liver Disease/metabolism* ; Animals ; Hepatocytes/metabolism* ; Lipid Metabolism ; Mice ; Humans ; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha ; AMP-Activated Protein Kinases/metabolism* ; Carnitine O-Palmitoyltransferase/metabolism* ; Diet, High-Fat ; Male ; Mice, Inbred C57BL ; Signal Transduction

OBJECTIVES: To investigate the association of NUF2 expression with tumor prognosis and its regulatory role in tumor microenvironment. METHODS: We analyzed NUF2 expression, its prognostic value, and is immune-related functions across different cancer types using datasets from the Human Protein Atlas (HPA), TCGA, GTEx, CCLE, and TIMER. RT-qPCR, Western blotting, and immunohistochemistry were used to detect NUF2 expression in liver cancer cell lines and tissue and blood samples from patients with liver cancer. GO, KEGG, and GSEA analyses were conducted to explore the molecular mechanisms of NUF2 and its related genes, and a competitive endogenous RNA (ceRNA) network for NUF2 in liver cancer was constructed. RESULTS: NUF2 expression was upregulated in the tumor tissues of 27 cancers and was associated with clinical stages in several cancers. High NUF2 expressions were correlated with poor overall survival, disease-specific survival, progression-free survival, and disease-free survival of cancer patients. NUF2 expression levels were positively correlated with tumor mutational burden, microsatellite instability, infiltrating immune cells, immune cell marker genes and immune checkpoint genes in different cancers. RT-qPCR, Western blotting, and immunohistochemistry confirmed that NUF2 expression was upregulated in liver cancer cell lines and tumor tissues and blood samples of liver cancer patients, and was decreased significantly after operation. GO, KEGG and GSEA analyses indicated that NUF2 was involved in chromosome segregation and cell cycle and was associated with glycine, serine and threonine metabolism. CONCLUSIONS NUF2 expression is upregulated in 27 cancers and is associated with clinical stage and poor prognosis in some malignancies. NUF2 expression is closely correlated with immune cell infiltration in different cancers, suggesting its potential value for predicting immunotherapy response in these cancers.
Humans ; Prognosis ; Immunotherapy ; Tumor Microenvironment ; Liver Neoplasms/metabolism* ; Cell Line, Tumor ; Neoplasms/genetics* ; Gene Expression Regulation, Neoplastic ; Biomarkers, Tumor/genetics*

OBJECTIVES: To investigate the clinical significance of SLC1A5 overexpression in pan-cancer and its mechanism for promoting hepatocellular carcinoma (HCC) progression. METHODS: We analyzed the correlation of SLC1A5 expression with clinical stage, lymph node metastasis and prognosis in pan-cancer using TCGA and ICGC datasets and explored its association with immune cell infiltration using EPIC, CIBERSORT, and TIMER algorithms. In HCC cell lines, the effects of lentivirus-mediated SLC1A5 overexpression or RNA interference on cell proliferation were examined using CCK-8 assay, and the growth of HCC cell xenografts overexpressing SLC1A5 was observed in nude mice. The effects of SLC1A5 overexpression or silencing in HCC cells on macrophage polarization were evaluated in a cell co-culture system. RESULTS: SLC1A5 was mainly localized on cell membrane and was highly expressed in most cancers in association with clinical stage, lymph node metastasis and poor prognosis. SLC1A5 expression was positively correlated with immunity score in 13 cancer types, especially in low-grade glioma (LGG), LIHC and thyroid cancer. SLC1A5 was positively correlated with macrophage infiltration level in LGG and LIHC but negatively correlated with macrophage infiltration in 5 cancers including lung squamous carcinoma, pancreatic carcinoma, and gastric carcinoma. Patients with SLC1A5 overexpression and high level of M2 macrophage infiltration had the worst survival outcomes. SLC1A5 was correlated with immunosuppression-related genes, cytokines, and cytokine receptors, which was the most obvious in LGG and LIHC. SLC1A5 was highly expressed in different HCC cell lines, and its overexpression promoted HCC cell proliferation both in vitro and in nude mice. In the cell co-culture experiment, SLC1A5 was positively correlated with the molecular markers of M2 polarization of macrophages, and its overexpression strongly promoted M2 polarization of the macrophages and inhibited T cell secretion of IFN-γ. CONCLUSIONS SLC1A5 expression level is correlated with clinical stage, lymph node metastasis, prognosis, and immune cell infiltration in most cancers, and its overexpression promotes HCC progression by inhibiting T-cell function via promoting M2 polarization of macrophages.
Humans ; Carcinoma, Hepatocellular/metabolism* ; Liver Neoplasms/metabolism* ; Animals ; Macrophages/cytology* ; Disease Progression ; Cell Line, Tumor ; Mice ; Amino Acid Transport System ASC/genetics* ; Cell Proliferation ; Lymphatic Metastasis ; Mice, Nude ; Prognosis ; Minor Histocompatibility Antigens

OBJECTIVES: To observe the evolution of intrahepatic macrophage polarization in mice with liver fibrosis induced by iron overload. METHODS: Thirty-two C57BL/6 mice (6-8 weeks) were randomized into control group (n=8) and liver fibrosis model group (n=24) induced by aidly intraperitoneal injection of iron dextran. At the 3rd, 5th, and 7th weeks of modeling, 8 mice in the model group were sacrificed for observing liver fibrosis using Masson, Sirius Red and immunohistochemical staining and detecting serum levels of ALT, AST and the levels of serum iron, ferritin, liver total Fe and ferrous Fe. iNOS⁺/F4/80⁺ cells and CD206⁺/F4/80⁺ cells were detected by double immunofluorescence assay to observe the proportion and distribution of M1 and M2 macrophages. The hepatic expressions of Arg-1, iNOS, IL-6, IL-10, and TNF‑α proteins were detected using Western blotting or ELISA, and the expression of CD206 mRNA was detected using RT-PCR. RESULTS: The mice in the model group showed gradual increase of fibrous tissue hyperplasia in the portal area over time, structural destruction of the hepatic lobules and formation of pseudolobules. With the passage of time during modeling, the rat models showed significantly increased hepatic expressions of α-SMA and COL-1, elevated serum levels of ALT, AST, Fe, ferritin, and increased liver total Fe and ferrous Fe levels. The expressions of M1 polarization markers IL-6, TNF‑α, and iNOS all increased with time and reached their peak levels at the 3rd week; The expressions of M2 polarization markers (IL-10 and Arg-1 proteins and CD206 mRNA) significantly increased in the 3rd week and but decreased in the 5th and 7th weeks. CONCLUSIONS Iron overload promotes M1 polarization of macrophages in mice. Liver fibrosis in the early stage promotes M2 polarization of macrophages but negatively regulate M2 polarization at later stages.
Animals ; Mice ; Mice, Inbred C57BL ; Iron Overload/pathology* ; Macrophages/metabolism* ; Male ; Liver Cirrhosis/etiology* ; Nitric Oxide Synthase Type II/metabolism* ; Interleukin-10/metabolism* ; Liver/pathology* ; Interleukin-6/metabolism* ; Mannose Receptor ; Tumor Necrosis Factor-alpha/metabolism* ; Mannose-Binding Lectins/metabolism* ; Arginase

OBJECTIVES: To study the therapeutic mechanism of Tuihuang Mixture against cholestasis. METHODS: Forty-eight Wistar rats were randomized equally into blank group, model group, ursodeoxycholic acid group and Tuihuang Mixture group. Except for those in the blank group, all the rats were given α‑naphthylisothiocyanate (ANIT) to establish rat models of cholestasis, followed by treatments with indicated drugs or distilled water. Serum levels of ALT, AST, ALP, γ-GT, TBA and TBIL of the rats were determined, and hepatic expressions IL-1β, IL-18, FXR, NLRP3, ASC, Caspase-1 and GSDMD were detected using q-PCR, ELISA or Western blotting. Histopathological changes of the liver tissues were observed using HE staining. RESULTS: The rat models of cholestasis had significantly increased serum levels of ALT, AST, ALP, γ-GT, TBA and TBIL with increased mRNA and protein expressions of IL-1β and IL-18, decreased protein and mRNA expressions of FXR, and increased protein expressions of NLRP3 and Caspase-1 and mRNA expressions of NLRP3, ASC, Caspase-1 and GSDMD in the liver tissue, showing also irregular arrangement of liver cells, proliferation of bile duct epithelial cells and inflammatory cells infiltration. Treatment of the rat models with Tuihuang Mixture significantly decreased serum levels of ALT, AST, ALP, γ-GT, TBA and TBIL, lowered IL-1β and IL-18 and increased FXR protein and mRNA expressions, and reduced NLRP3, ASC, Caspase-1 and GSDMD proteins and NLRP3, ASC and Caspase-1 mRNA expressions in the liver tissue. Tuihuang Mixture also significantly alleviated hepatocyte injury, bile duct epithelial cell proliferation and inflammatory cell infiltration in the liver of the rat models. CONCLUSIONS Tuihuang Mixture can effectively improve cholestasis in rats possibly by inhibiting NLRP3 inflammatosome-mediated pyroptosis via regulating FXR.
Animals ; NLR Family, Pyrin Domain-Containing 3 Protein ; Rats ; Receptors, Cytoplasmic and Nuclear/metabolism* ; Cholestasis/drug therapy* ; Rats, Wistar ; Inflammasomes/metabolism* ; 1-Naphthylisothiocyanate ; Drugs, Chinese Herbal/therapeutic use* ; Male ; Interleukin-18/metabolism* ; Caspase 1/metabolism* ; Interleukin-1beta/metabolism* ; Liver/metabolism*

OBJECTIVES: To investigate the inhibitory effect of Zheng GanDecoction (ZGF) on tumor progression in a rat model of diethylnitrosamine (DEN)-induced hepatocellular carcinoma (HCC) and explore the possible mechanism. METHODS: Seventy SD rats were subjected to regular intraperitoneal injections of DEN (50 mg/kg) for 12 weeks to induce HCC tumorigenesis, with another 10 rats receiving saline injections as the normal control. After successful modeling, the rats were randomized into 5 groups (n=10) for daily treatment with distilled water ( model group), Huaier Granules (4 g/kg; positive control group), or ZGF at low, medium, and high doses (2, 4, and 8 g/kg, respectively) via gavage for 17 weeks. Body weight changes of the rats were monitored, and after completion of the treatments, the rats were euthanized for measurement of liver, spleen and thymus indices and morphological and histopathological examinations of the liver tissues using HE staining. The expressions of YAP, p-YAP, MST1, LATS1 and p-LATS1 in the liver tissues were detected using immunohistochemistry and Western blotting. RESULTS: Compared with the normal control rats, the rat models with DEN-induced HCC exhibited much poorer general condition with a significantly reduced survival rate, increased body weight and liver and spleen indices, and a lowered thymus index. ZGF treatment obviously reduced liver and spleen indices, increased the thymus index, and improved pathologies of the liver tissues of the rat models. Immunohistochemistry and Western blotting showed a dose-dependent reduction of YAP expression and an increment of p-YAP expression in ZGF-treated rats, which also exhibited significantly upregulated hepatic expressions of MST1, LATS1 and p-LATS1. CONCLUSIONS ZGF inhibits DEN-induced HCC in rats by activating the Hippo/YAP pathway via upregulating MST1 and LATS1 expression, which promotes YAP phosphorylation and degradation to suppress proliferation and induce apoptosis of the tumor cells.
Animals ; Drugs, Chinese Herbal/pharmacology* ; Diethylnitrosamine ; Rats, Sprague-Dawley ; Rats ; Signal Transduction/drug effects* ; Protein Serine-Threonine Kinases/metabolism* ; Carcinoma, Hepatocellular/drug therapy* ; YAP-Signaling Proteins ; Liver Neoplasms/drug therapy* ; Hippo Signaling Pathway ; Male ; Liver Neoplasms, Experimental/metabolism* ; Transcription Factors/metabolism* ; Adaptor Proteins, Signal Transducing/metabolism*

OBJECTIVES: To investigate the protective effect of catalpol against triptolide-induced liver injury and explore its mechanism to test the Fuzheng Zhidu theory for detoxification. METHODS: C57BL/6J mice were randomized into blank control group, catalpol group, triptolide group and triptolide+catalpol group. After 13 days of treatment with the agents by gavage, the mice were examined for liver tissue pathology, liver function, hepatocyte subcellular structure, lipid peroxidation, ferrous ion deposition and expressions of ferroptosis-related proteins in the liver. In a liver cell line HL7702, the effect of catalpol or the ferroptosis inhibitor Fer-1 on triptolide-induced cytotoxicity was tested by examining cell functions, Fe²⁺ concentration, lipid peroxidation, ROS level and the ferroptosis-related proteins. RESULTS: In C57BL/6J mice, catalpol significantly alleviated triptolide-induced hepatic injury, lowered the levels of ALT, AST and LDH, and reversed the elevation of Fe²⁺ concentration and MDA level and the reduction of GP_X level. In HL7702 cells, inhibition of ferroptosis by Fer-1 significantly reversed triptolide-induced elevation of ALT, AST and LDH levels. Western blotting and qRT-PCR demonstrated that catalpol reversed abnormalities in expressions of SLC7A11, FTH1 and GPX4 at both the mRNA and protein levels in triptolide-treated HL7702 cells. CONCLUSIONS The combined use of catalpol can reduce the hepatotoxicity of triptolide in mice by inhibiting excessive hepatocyte ferroptosis through the SLC7A11/GPX4 pathway.
Animals ; Phenanthrenes/toxicity* ; Ferroptosis/drug effects* ; Diterpenes/toxicity* ; Epoxy Compounds/toxicity* ; Mice, Inbred C57BL ; Hepatocytes/metabolism* ; Mice ; Phospholipid Hydroperoxide Glutathione Peroxidase ; Iridoid Glucosides/pharmacology* ; Liver/metabolism* ; Chemical and Drug Induced Liver Injury/prevention & control* ; Male ; Amino Acid Transport System y+/metabolism*