Objective To analyze the changing trends of the burden of non-alcoholic fatty liver disease(NAFLD)in China from 1990 to 2021 and provide a basis for formulating prevention and treatment strategies.Methods The standardized incidence rate,prevalence,mortality,and disability-adjusted life year(DALY)rate of NAFLD in China from 1990 to 2021 were extracted from the Global Burden of Disease Study 2021.The average annual percentage change of rate data was calculated by Joinpoint 4.2 and the age,period,and birth cohort effects of the prevalence and DALY rate were analyzed by the age-period-cohort model.Results Compared to 1990,the incidence rate and prevalence of NAFLD have been on the rise,while the mortality and DALY rate have been declining.The age effect curves of prevalence and DALY rate showed an upward trend followed by a downward trend for both males and females.With the period from 1992 to 1996 as the reference group,the period effect curve of prevalence showed a downward trend followed by an upward trend,being the lowest in the period from 2002 to 2006(RR=0.93).The period effect curve of DALY rate showed a downward trend from 1992 to 2011 and then tended to flatten out.With the period from 1972 to 1981 as the reference group,the birth cohort effect curve of prevalence showed a steady upward trend in the general population and both male and female populations.The birth cohort effect curve of DALY rate showed an overall upward trend followed by a downward trend,with the peak occurring in the birth cohort group between 1922 and 1931.The DALY rate of NAFLD caused by smoking and high fasting blood glucose has shown a downward trend since 2014,and fasting blood glucose gradually became the dominant factor as age increased.Conclusions From 1990 to 2021,NAFLD in China has shown a rising prevalence but a significantly declining DALY rate.This suggests that current prevention and control strategies are effective,and further efforts should be made to raise residents' health awareness in controlling the occurrence and development of NAFLD.
Humans ; Non-alcoholic Fatty Liver Disease/epidemiology* ; China/epidemiology* ; Prevalence ; Female ; Male ; Incidence ; Disability-Adjusted Life Years ; Middle Aged ; Adult

Inflammaging is a process of cellular dysfunction associated with chronic inflammation, which plays a significant role in the onset and progression of liver diseases. Research on its mechanisms has become a hotspot. In viral hepatitis, inflammaging primarily involve oxidative stress, cell apoptosis and necrosis, as well as gut microbiota dysbiosis. In non-alcoholic fatty liver disease, inflammaging is more complex, involving insulin resistance, fat deposition, lipid metabolism disorders, gut microbiota dysbiosis, and abnormalities in NAD⁺ metabolism. In liver tumors, inflammaging is characterized by weakening of tumor suppressive mechanisms, remodeling of the liver microenvironment, metabolic reprogramming, and enhanced immune evasion. Therapeutic strategies targeting inflammaging have been developing recently, and antioxidant therapy, metabolic disorder improvement, and immunotherapy are emerging as important interventions for liver diseases. This review focuses on the mechanisms of inflammaging in liver diseases, aiming to provide novel insights for the prevention and treatment of liver diseases.
Humans ; Liver Diseases/pathology* ; Inflammation ; Oxidative Stress ; Non-alcoholic Fatty Liver Disease ; Liver Neoplasms ; Gastrointestinal Microbiome

BACKGROUND: Many factors are associated with the development and progression of liver fat and fibrosis; however, genetics and the gut microbiota are representative factors. Moreover, recent studies have indicated a link between host genes and the gut microbiota. This study investigated the effect of patatin-like phospholipase domain-containing 3 (PNPLA3) rs738409 (C > G), which has been reported to be most involved in the onset and progression of fatty liver, on liver fat and fibrosis in a cohort study related to gut microbiota in a non-fatty liver population. METHODS: This cohort study included 214 participants from the health check-up project in 2018 and 2022 who had non-fatty liver with controlled attenuation parameter (CAP) values <248 dB/m by FibroScan and were non-drinkers. Changes in CAP values and liver stiffness measurement (LSM), liver-related items, and gut microbiota from 2018 to 2022 were investigated separately for PNPLA3 rs738409 CC, CG, and GG genotypes. RESULTS: Baseline values showed no difference among the PNPLA3 rs738409 genotypes for any of the measurement items. From 2018 to 2022, the PNPLA3 rs738409 CG and GG genotype groups showed a significant increase in CAP and body mass index; no significant change was observed in the CC genotype group. LSM increased in all genotypes, but the rate of increase was highest in the GG genotype, followed by the CG and CC genotypes. Fasting blood glucose levels increased in all genotypes; however, HOMA-IR (Homeostasis Model Assessment of Insulin Resistance) increased significantly only in the GG genotype. HDL (high-density lipoprotein) and LDL (low-density lipoprotein) cholesterol levels significantly increased in all genotypes, whereas triglycerides did not show any significant changes in any genotype. As for the gut microbiota, the relative abundance of Feacalibacterium in the PNPLA3 rs738409 GG genotype decreased by 2% over 4 years, more than 2-fold compared to CC and GG genotypes. Blautia increased significantly in the CC group. CONCLUSION The results suggest that PNPLA3 G-allele carriers of non-fatty liver develop liver fat and fibrosis due to not only obesity and insulin resistance but also the deterioration of gut microbiota, which may require a relatively long course of time, even years.
Humans ; Gastrointestinal Microbiome ; Male ; Female ; Membrane Proteins/metabolism* ; Lipase/genetics* ; Middle Aged ; Liver Cirrhosis/epidemiology* ; Cohort Studies ; Genotype ; Adult ; Non-alcoholic Fatty Liver Disease/microbiology* ; Polymorphism, Single Nucleotide ; Acyltransferases ; Phospholipases A2, Calcium-Independent

BACKGROUND: Mitochondria, which harbor their own genome (mtDNA), have attracted attention due to the potential of mtDNA copy number (mtDNA-CN) as an indicator of mitochondrial dysfunction. Although mtDNA-CN has been proposed as a simple and accessible biomarker for metabolic disorders such as metabolic dysfunction-associated steatotic liver disease, the underlying mechanisms and the causal relationship remain insufficiently elucidated. In this investigation, we combined longitudinal epidemiological data, animal studies, and in vitro assays to elucidate the potential causal relationship between reduced mtDNA-CN and the development of steatotic liver disease (SLD). METHODS: We conducted a longitudinal study using data from a health examination cohort initiated in 1981 in Yakumo, Hokkaido, Japan. Data from examinations performed in 2015 and 2022 were analyzed, focusing on 76 subjects without SLD at baseline (2015) to assess the association between baseline mtDNA-CN and subsequent risk of SLD development. In addition, 28-day-old SD rats were fed ad libitum on a 45% high-fat diet and dissected at 2 and 8 weeks of age. Blood and liver mtDNA-CN were measured and compared at each feeding period. Additionally, in vitro experiments were performed using HepG2 cells treated with mitochondrial function inhibitors to induce mtDNA-CN depletion and to examine its impact on intracellular lipid accumulation. RESULTS: Epidemiological analysis showed that the subjects with low mtDNA-CN had a significantly higher odds ratio for developing SLD compared to high (odds ratio [95% confidence interval]: 4.93 [1.08-22.50]). Analysis of the animal model showed that 8 weeks of high-fat diet led to the development of fatty liver and a significant decrease in mtDNA-CN. A further 2 weeks of high-fat diet consumption resulted in a significant decrease in hepatic mtDNA-CN, despite the absence of fatty liver development, and a similar trend was observed for blood. Complementary in vitro experiments revealed that pharmacologically induced mitochondrial dysfunction led to a significant reduction in mtDNA-CN and was associated with increases in intracellular lipid accumulation in HepG2 cells. CONCLUSIONS Our findings suggest that reduced mtDNA-CN may contribute causally to SLD development and could serve as a convenient, noninvasive biomarker for early detection and risk assessment.
Animals ; DNA, Mitochondrial/genetics* ; Humans ; Male ; DNA Copy Number Variations ; Female ; Fatty Liver/blood* ; Rats ; Middle Aged ; Longitudinal Studies ; Rats, Sprague-Dawley ; Adult ; Japan/epidemiology* ; Aged ; Biomarkers/blood* ; Hep G2 Cells ; Diet, High-Fat/adverse effects*

OBJECTIVE: To investigate the therapeutic potential of pseudolaric acid B (PAB) on non-alcoholic fatty liver disease (NAFLD) and its underlying molecular mechanism in vitro and in vivo. METHODS: Eight-week-old male C57BL/6J mice (n=32) were fed either a normal chow diet (NCD) or a high-fat diet (HFD) for 8 weeks. The HFD mice were divided into 3 groups according to a simple random method, including HFD, PAB low-dose [10 mg/(kg·d), PAB-L], and PAB high-dose [20 mg/(kg·d), PAB-H] groups. After 8 weeks of treatment, glucose metabolism and insulin resistance were assessed by oral glucose tolerance test (OGTT) and insulin tolerance test (ITT). Biochemical assays were used to measure the serum and cellular levels of total cholesterol (TC), triglycerides (TG), aspartate aminotransferase (AST), alanine aminotransferase (ALT), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C). White adipose tissue (WAT), brown adipose tissue (BAT) and liver tissue were subjected to hematoxylin and eosin (H&E) staining or Oil Red O staining to observe the alterations in adipose tissue and liver injury. PharmMapper and DisGeNet were used to predict the NAFLD-related PAB targets. Peroxisome proliferator-activated receptor alpha (PPARα) pathway involvement was suggested by Kyoto Encyclopedia of Genes and Genomes (KEGG) and search tool Retrieval of Interacting Genes (STRING) analyses. Luciferase reporter assay, cellular thermal shift assay (CETSA), and drug affinity responsive target stability assay (DARTS) were conducted to confirm direct binding of PAB with PPARα. Molecular dynamics simulations were applied to further validate target engagement. RT-qPCR and Western blot were performed to assess the downstream genes and proteins expression, and validated by PPARα inhibitor MK886. RESULTS: PAB significantly reduced serum TC, TG, LDL-C, AST, and ALT levels, and increased HDL-C level in HFD mice (P<0.01). Target prediction analysis indicated a significant correlation between PAB and PPARα pathway. PAB direct target binding with PPARα was confirmed through luciferase reporter assay, CETSA, and DARTS (P<0.05 or P<0.01). The target engagement between PAB and PPARα protein was further confirmed by molecular dynamics simulations and the top 3 amino acid residues, LEU321, MET355, and PHE273 showed the most significant changes in mutational energy. Subsequently, PAB upregulated the genes expressions involved in lipid metabolism and mitochondrial biogenesis downstream of PPARα (P<0.05 or P<0.01). Significantly, the PPARα inhibitor MK886 effectively reversed the lipid-lowering and PPARα activation properties of PAB (P<0.05 or P<0.01). CONCLUSION PAB mitigates lipid accumulation, ameliorates liver damage, and improves mitochondrial biogenesis by binding with PPARα, thus presenting a potential candidate for pharmaceutical development in the treatment of NAFLD.
Animals ; PPAR alpha/metabolism* ; Non-alcoholic Fatty Liver Disease/pathology* ; Male ; Mice, Inbred C57BL ; Lipid Metabolism/drug effects* ; Diterpenes/therapeutic use* ; Organelle Biogenesis ; Diet, High-Fat ; Humans ; Mice ; Liver/metabolism* ; Insulin Resistance ; Mitochondria/metabolism* ; Molecular Docking Simulation

In recent years, gut microbiota has been increasingly recognized as a key player in ethanol metabolism and the development of related diseases. On one hand, ethanol intake directly affects the gut, leading to significant alterations in microbial diversity and composition. On the other hand, gut microbiota influences ethanol-induced damage to various organs, especially the liver, through multiple metabolic byproducts (such as short-chain fatty acids like butyrate, propionate, and acetate), modulation of immune responses, alteration of intestinal barrier function, and regulation of ethanol-metabolizing enzymes. Given the close association between gut microbiota and ethanol metabolism, the gut microbiome presents a promising therapeutic target for alcohol-related liver diseases. This review summarizes recent advances in understanding how gut microbiota affects ethanol metabolism, aiming to elucidate its role in the onset and progression of ethanol-related diseases and to provide a theoretical basis and novel targets for microbiota-based interventions.
Gastrointestinal Microbiome/physiology* ; Ethanol/metabolism* ; Humans ; Fatty Acids, Volatile/metabolism* ; Liver Diseases, Alcoholic/metabolism* ; Animals ; Alcohol Drinking/metabolism*

Non-alcoholic fatty liver disease (NAFLD), including non-alcoholic fatty liver (NAFL), non-alcoholic steatohepatitis (NASH), and advanced fibrosis, is a leading cause of chronic liver disease worldwide, progressing to cirrhosis and ultimately hepatocellular carcinoma (HCC). Excessive accumulation of fatty acids in the liver triggers multiple forms of hepatocyte death and exacerbates NAFLD progression, with pyroptosis and apoptosis considered key events. Recent studies show that cysteine aspartic acid specific protease-3 (caspase-3) is a central regulator of both pyroptosis and apoptosis in NAFLD. Activated caspase-3 not only directly induces apoptosis but also cleaves the N-terminal domain of gasdermin E (GSDME), disrupts cell membranes, releases inflammatory factors, and thereby mediates pyroptosis. Inhibiting caspase-3 expression in NAFLD can alleviate hepatocyte injury (such as ballooning degeneration), dampen pro-inflammatory signaling, and reduce apoptosis. Caspase-3 acts as a key node coordinating pyroptosis and apoptosis and may serve as a novel therapeutic target for the prevention and treatment of NAFLD.
Non-alcoholic Fatty Liver Disease/metabolism* ; Humans ; Pyroptosis/physiology* ; Apoptosis/physiology* ; Caspase 3/physiology* ; Animals ; Gasdermins

OBJECTIVES: Non-alcoholic fatty liver disease (NAFLD) and hypertension are common metabolic disorders, both closely associated with insulin resistance (IR), suggesting potential shared pathological mechanisms. This study aims to investigate the mediating role of IR in the relationship between hypertension and NAFLD, and to evaluate the applicability and modeling value of various IR surrogate indices in predicting NAFLD risk. METHODS: A total of 280 976 individuals who underwent health examinations at the Health Management Center of the Third Xiangya Hospital of Central South University between August 2017 and December 2021 were included. NAFLD was diagnosed based on abdominal ultrasound findings, and hypertension was defined according to the criteria of the Chinese Guidelines for the Management of Hypertension. Demographic information, anthropometric indices, and biochemical parameters were collected, and multiple IR surrogate indices were constructed, including the triglyceride-glucose index (TyG) and its derivatives, as well as the metabolic score for insulin resistance (METS-IR). Group comparisons were performed between hypertensive and non-hypertensive participants, as well as between NAFLD and non-NAFLD participants. Pearson correlation analysis was applied to assess the associations of metabolic parameters and IR indices with NAFLD. Furthermore, mediation models were constructed to explore the mediating role of IR in the "hypertension-NAFLD" relationship. Finally, parametric models and machine learning algorithms were compared to evaluate their predictive performance and value in assessing NAFLD risk in this population. RESULTS: The prevalence of NAFLD was significantly higher in hypertensive individuals than in non-hypertensive participants (63.61% vs 33.79%, P<0.001), accompanied by elevated IR levels and adverse metabolic features. Correlation analysis and variable importance rankings across multiple models consistently identified TyG-waist circumference (TyG-WC) and METS-IR as the IR indices most strongly associated with NAFLD. In mediation analysis, the TyG-WC pathway explained 32.03% of the total effect, and the METS-IR pathway explained 17.02%. Interaction analysis showed that hypertension status may attenuate the mediating effect of IR (all interaction estimates were negative). In prediction model comparisons, the simplified model incorporating sex, age, WC, TyG-WC, and METS-IR demonstrated good performance in the test set. Logistic regression and its regularized form (LASSO regression) achieved an accuracy of 0.83, receiver operating characteristic (ROC)-area under the curve (AUC) of 0.91, and a Brier score of 0.12, comparable to ensemble models (random forest and XGBoost), with consistently stable performance across different algorithms. CONCLUSIONS IR plays a significant mediating role in the association between hypertension and NAFLD, with TyG-WC identified as a key indicator showing strong mechanistic relevance and predictive value. Risk prediction models based on IR surrogate indices demonstrate advantages in simplicity and interpretability, providing empirical support for the early screening and individualized prevention of NAFLD in the general population.
Humans ; Non-alcoholic Fatty Liver Disease/complications* ; Insulin Resistance ; Hypertension/epidemiology* ; Male ; Female ; Middle Aged ; Risk Factors ; Adult ; Machine Learning ; Triglycerides/blood*

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