Shedding light on non-alcoholic fatty liver disease: Pathogenesis, molecular mechanisms, models, and emerging therapeutics

DNA hypermethylation-induced suppression of ALKBH5 is required for folic acid to alleviate hepatic lipid deposition by enhancing autophagy in an ATG12-dependent manner

Nonalcoholic fatty liver disease (NAFLD) occurs when too much fat builds up in the liver. As a growing worldwide epidemic, NAFLD is strongly linked with multiple metabolic diseases including obesity, insulin resistance, and dyslipidemia. However, very few effective treatments are currently available. Folate, an essential B-group vitamin with important biological functions including DNA and RNA methylation regulation, has been shown to have a protective effect against NAFLD with its underlying mechanism remains largely unclear. Here, we show that administration of folic acid significantly improves glucose tolerance, insulin sensitivity, and dyslipidemia in high-fat diet (HFD) fed mice. Moreover, folic acid treatment significantly inhibits lipid deposition in hepatocytes both in vivo and in vitro. Mechanically, folic acid reduces the expression of m6A demethylase AlkB homolog 5 (ALKHB5) via promoter DNA hypermethylation. Decreased ALKBH5 causes increased m6A modification and increased expression of ATG12 in a demethylase activity-dependent manner, thereby promoting autophagy and preventing hepatic steatosis. Inhibition of ATG12 induced by overexpression of ALKBH5 could impair autophagy and the inhibitory effect of folic acid on lipid accumulation in hepatocytes. Together, these findings provide novel insights into understanding the protective role of folic acid in the treatment of NAFLD and suggest that folic acid may be a potential agent for combating NAFLD.

The role of C-reactive protein to lymphocyte ratio in NAFLD and mortality among NAFLD patients

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is recognized as the predominant chronic liver disorder globally. Inflammation is integral to the onset and progression of NAFLD. The C-reactive protein to lymphocyte ratio (CLR), a novel inflammatory marker, has yet to be explored in the context of NAFLD.

METHOD

This investigation encompassed 4371 individuals from the National Health and Nutrition Examination Survey (NHANES) conducted between 2015-2018. Weighted logistic regression was employed to examine the correlation between CLR and NAFLD. Weighted Cox proportional hazards models were utilized to evaluate the association between CLR and all-cause and Cardiovascular disease (CVD) mortality in patients with NAFLD. Restricted cubic spline (RCS) curves were employed to assess the dose-response relationship. Threshold effect analysis was used to determine the existence of an inflection point.

RESULT

After adjusting for all included covariates in Model 3, a positive correlation between lnCLR and NAFLD was identified (OR = 1.45, 95% CI = 1.16-1.81, P = 0.010). However, no significant association was observed between it and all-cause as well as CVD mortality among patients with NAFLD. The RCS curve illustrated a nonlinear association between CLR and NAFLD (P-nonlinear < 0.0001). Threshold effect analysis determined that the inflection point occurs at CLR = 1.667.

CONCLUSION

CLR exhibited a nonlinear positive association with NAFLD. Higher CLR levels may increase the risk of NAFLD. However, CLR does not affect all-cause and CVD mortality in patients with NAFLD.

Deficiency of β-arrestin2 ameliorates MASLD in mice by promoting the activation of TAK1/AMPK signaling

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a liver manifestation of metabolic syndrome characterized by excessive hepatic lipid accumulation and lipid metabolism disorders. It has become the most common chronic liver disease worldwide. β-arrestin2 is a multifunctional scaffold protein that is among the most important regulatory molecules, and it exerts key roles in regulating various cellular processes, such as immune response, cellular collagen production, and inflammation. In the current study, we aimed to explore the function of β-arrestin2 in the development and progression of MASLD. Firstly, we observed that the expression of β-arrestin2 was upregulated in liver samples from patients with MASLD. Then, the western diet (WD) combined with CCl4 injection-induced MASLD was established in wild-type mice, and showed that liver β-arrestin2 expression was also gradually increased, and positively correlated with the degree of lipid metabolism disorder during MASLD progression. Ulteriorly, β-arrestin2 knockout (Arrb2 KO) mice were utilized to induce the MASLD model and found that β-arrestin2 deficiency significantly ameliorated lipid accumulation and inflammatory response in the liver of MASLD mice. Furthermore, the in vitro depletion and overexpression experiments showed that increased β-arrestin2 aggravated lipid accumulation via inhibiting the activation of the TAK1/AMPK pathway, which may be mediated by competitively binding to TAB1 with TAK1. These findings suggest that β-arrestin2 is essential to regulate intrahepatic lipid metabolism. Here, we provide a novel insight in understanding of the expression and function of β-arrestin2 in MASLD, demonstrating that it may be a potential therapeutic target for MASLD treatment.

Identification of pyroptosis-associated gene to predict fibrosis and reveal immune characterization in non-alcoholic fatty liver disease

Despite advances in research, studies on predictive models for Non-Alcoholic Fatty Liver Disease (NAFLD)-related fibrosis remain limited. Identifying new biomarkers to distinguish Non-Alcoholic Steatohepatitis (NASH) from NAFLD would aid in the treatment of NASH. Gene expression and clinical profiles of NAFL and NASH patients were collected from databases. Differentially expressed genes with prognostic value were used to construct predictive model. Validation of fibrosis stage-related pyroptosis-related genes (PRGs) was performed using Sprague-Dawley rats liver fibrosis models induced by CCl4 or PS. Immune cell infiltration assessment demonstrated that stromal score, immune score, and ESTIMATE score were higher in patients with NASH compared to those with NAFL. BAX, BAK1, PYCARD, and NLRP3 were identified as hub genes that exhibit a strong correlation with fibrosis stage. Additionally, the expression of these genes was increased in fibrotic liver tissues induced by CCl4 and PS. The pyroptosis-associated gene signature effectively predicts the degree of liver fibrosis in NASH patients. Our study indicates that BAX, BAK1, PYCARD, and NLRP3 might serve as biomarkers for NASH-associated fibrosis.

BRCA1 regulates glucose and lipid metabolism in diabetes mellitus with metabolic dysfunction-associated steatotic liver disease via the PI3K/Akt signaling pathway

PURPOSE

This study mimics the metabolic environment of metabolic dysfunction-associated steatotic liver disease (MASLD) and diabetic mellitus (DM) to investigate the function of BRCA1 in regulating glucose and lipid metabolism in hepatocytes under high glucose (HG) settings.

METHODS

MASLD and DM-related datasets (GSE89632, GSE95849) were screened for overlapping genes, Protein-Protein Interaction (PPI) network and enrichment analyses were performed. Then, quantitative real-time polymerase chain reaction (qRT-PCR), Western Blotting (WB), and enzymatic colorimetric assays to examine the expression changes of BRCA1 in mouse primary hepatocytes under HG conditions and the impact of the combined PI3K/Akt signaling pathway on key metabolic markers of gluconeogenesis and lipid metabolism.

RESULTS

Our study identified seven key overlapping genes (AURKA, BRCA1, ISG15, NUSAP1, OAS1, RSAD2, TLR7) between MASLD and DM. Experiments found that when BRCA1 was overexpressed in mouse primary hepatocytes, intracellular triglyceride content and lipid metabolism-related biomarkers (such as PEPCK, SREBP-1c, G6Pase, and FAS) were significantly increased in HG circumstances. However, the knockdown of BRCA1 reduced the expression of these indicators. Besides, we also observed that under HG conditions, the expression of proteins linked to the PI3K/Akt signaling pathway was negatively regulated by BRCA1 expression. Moreover, TG content and expression of lipid metabolism markers are also regulated by BRCA1 and PI3K/Akt pathway inhibitor Ly294002.

CONCLUSION

As a key regulator of hepatocyte metabolism under HG conditions, BRCA1 can participate in regulating glucose and lipid metabolism in mouse primary hepatocytes through the PI3K/AKT signaling pathway, which be able to become a possible remedy strategy for DM with MASLD.

Association between oxidative stress and liver fibrosis severity in non-alcoholic fatty liver disease: insights from the pro-oxidant antioxidant balance method in a population from Tehran and Mashhad, Iran

Background

The exact mechanisms of non-alcoholic fatty liver disease (NAFLD), recently redefined as metabolic dysfunction-associated steatotic liver disease (MASLD), remain unclear. However, oxidative stress is recognized as a factor across all stages of NAFLD. The Pro-oxidant Antioxidant Balance (PAB) method is an important clinical tool that provides an assessment of the balance between oxidants and antioxidant. We aimed to explore oxidative stress in NAFLD using the PAB method.

Methods

Individuals with NAFLD were recruited in 2021. Eligible participants underwent detailed assessments, including liver elastography for fibrosis evaluation. Blood samples (5 mL) were collected to measure serum PAB levels. The METAVIR score, derived from FibroScan measurements of liver stiffness, categorized fibrosis severity from F0 (no fibrosis) to F4 (advanced fibrosis or cirrhosis).

Results

The study included 102 participants, with a mean age of 50.12 ± 10.03 years. Significant correlations were observed between FibroScan scores and variables such as age, body mass index (BMI), history of chronic diseases, and family history of NAFLD. PAB levels were notably higher in patients with advanced fibrosis (F2 and F3 groups: 86.32 ± 25.53) compared to those in early stages (F0 and F1 groups: 45.36 ± 21.29). Moreover, FibroScan scores showed a significant positive association with PAB values (odds ratio [OR]: 1.07; 95% confidence interval (CI): 1.04, 1.10), even after adjusting for confounding variables (OR: 1.13; 95% CI: 1.07, 1.18).

Conclusion

Elevated PAB levels were strongly associated with advanced stages of liver fibrosis in NAFLD patients, reflecting increased oxidative stress with disease progression. These results highlight the potential of PAB as a marker for monitoring oxidative stress and disease severity in NAFLD. Nevertheless, further large-scale studies are warranted.

A guide to pathophysiology, signaling pathways, and preclinical models of liver fibrosis

Liver fibrosis is potentially a reversible form of liver disease that evolved from the early stage of liver scarring as a consequence of chronic liver injuries. Recurrent injuries in the liver without any appropriate medication cause the injuries to get intense and deeper, which gradually leads to the progression of irreversible cirrhosis or carcinoma. Unfortunately, there are no approved treatment strategies for reversing hepatic fibrosis, making it one of the significant risk factors for developing advanced liver disorders and liver disease-associated mortality. Consequently, the interpretation of the fundamental mechanisms, etiology, and pathogenesis is crucial for identifying the potential therapeutic target as well as evaluating novel anti-fibrotic therapy. However, despite innumerable research, the functional mechanism and disease characteristics are still obscure. To accelerate the understanding of underlying disease pathophysiology, molecular pathways and disease progression mechanism, it is crucial to mimic human liver disease through the formation of precise disease models. Although various in vitro and in vivo liver fibrotic models have emerged and developed already, a perfect clinical model replicating human liver diseases is yet to be established, which is one of the major challenges in discovering proper therapeutics. This review paper will shed light on pathophysiology, signaling pathways, preclinical models of liver fibrosis, and their limitations.

Neuregulin1 ameliorates metabolic dysfunction-associated fatty liver disease via the ERK/SIRT1 signaling pathways

BACKGROUND

Neuregulin (NRG) family is involved in energy metabolism, among which NRG1 is a neuregulin proved to play a protective role in MAFLD cells. But the presice echanism has not been fully illustrated. This study aimed to investigate the role of NRG1 via the ERK/SIRT1 signaling in the pathogenesis of MAFLD.

METHODS

C57BL/6 mice were fed with high-fat diet for 8 weeks, and then injected with NRG1 (0.3 mg/kg/d) and PD98059 (0.3 mg/kg/d) via tail vein for 5 weeks. HepG2 cells induced by oleic acid and palmitic acid were treated with 20ng/mL NRG1 and 10µmol/L PD98059. The changes of histopathological, biochemical indexes, inflammatory factors, lipid metabolism, apoptosis and autophagy parameters were measured.

RESULTS

The expressions of NRG1 in MAFLD cell and animal models were significantly lower than that in the control group. After the intervention of ERK inhibitor PD98059, the expression of NRG1 decreased significantly in vivo, but no significant change was observed in vitro. Moreover, NRG1 ameliorated hepatic steatosis, enhanced cell viability, reduced cell apoptosis, and attenuated liver injury both in vitro and in vivo. After NRG1 intervention, the expressions of ERBB2, ERBB3, p-ERK1/2, SIRT1 and p-FOXO1 as well as the LC3II/I ratio in MAFLD cells and liver tissues of MAFLD mice were significantly increased, while the expression of SREBP1c was decreased. The aforementioned therapeutic effect of NRG1 was lost after the intervention of PD98059.

CONCLUSION

NRG1 might play a protective role in the pathogenesis of MAFLD by activating the downstream ERK1/2 through ErbB2-ErbB3, which promotes the expression of SIRT1 and autophagy markers. This study might indicate a new therapeutic strategy for MAFLD.

The obesity-related mutation gene on nonalcoholic fatty liver disease

The prevalence of overweight and obesity is increasing, leading to metabolic-associated fatty liver disease (MAFLD) characterized by excessive accumulation of liver fat and a risk of developing hepatocellular carcinoma (HCC). The driver gene mutations may play the roles of passengers that occur in single 'hotspots' and can promote tumorigenesis from benign to malignant lesions. We investigated the impact of high body weight and BMI on HCC survival using The Cancer Genome Atlas Liver Hepatocellular Carcinoma (TCGA-LIHC) dataset. To explore the effects of obesity-related gene mutations on HCC, we collected driver mutation genes in 34 TCGA patients with BMI ≥ 27 and 23 TCGA patients with BMI < 27. The digital PCR performing the PBMC samples for the variant rate by clinical cohort of 96 NAFLD patients. Our analysis showed that obesity leads to significantly worse survival outcomes in HCC. Using cbioportal, we identified 414 driver mutation genes in patients with obesity and 127 driver mutation genes in non-obese patients. Functional analysis showed that obese-related genes significantly enriched the regulated lipid and insulin pathways in HCC. The insulin secretion pathway in patients with obesity HCC-specific survival identified ABCC8 and PRKCB as significant genes (p < 0.001). It revealed significant differences in gene mutation and gene expression profiles compared to non-obese patients. The digital PCR test ABCC8 variants were detected in PBMC samples and caused a 14.5% variant rate, significantly higher than that of non-obese NAFLD patients. The study findings showed that the gene ABCC8 was a patient with the obesity-related gene in NAFLD, which provides the probability that ABCC8 mutation contributes to the pre-cancer lesion biomarker for HCC.

Female C57BL/6 mice exhibit protection against nonalcoholic fatty liver disease and diabesity accompanied by differential regulation of hepatic lipocalin prostaglandin D2 synthase

Nonalcoholic fatty liver disease (NAFLD) and its development into nonalcoholic steatohepatitis (NASH) are challenging health concerns globally. Clinically, the prevalence and severity of NAFLD/NASH are higher in men than in premenopausal women. NAFLD is strongly correlated with obesity, both of which are tied to high-fat/fructose-rich western diets. Therefore, we aimed to investigate sexual dimorphism in NAFLD pathogenesis in male and female C57BL/6 mice fed different diets. Male and female C57BL/67 mice were divided into four groups and kept on a chow (C), chow plus high fructose (CF), high fat (HF), and high fat plus high fructose (HFF) diet for 22 weeks. Liver tissues were collected at the end of the study and processed for NAFLD/NASH-related histology (H&E and trichrome staining), protein expression (SREBP1, SCAP, FABP4, α-SMA, TGF-β and L-PGDS), and biochemical parameters measurement. Our results displayed that female mice exhibited protection against NAFLD and diabesity on HF and HFF diets compared to male mice fed similar diets. Additionally, female mice showed protection from fibrosis compared to male mice. Both male and female mice fed HF and HFF diet groups displayed the cytosol-to-nuclear translocation of Lipocalin Prostaglandin D2 Synthase (L-PGDS). Cytoplasmic levels of L-PGDS were absent in females compared to low levels in males, revealing a possible sex-specific mechanism tied to fructose and fat metabolism. Collectively, female mice showed protection against NAFLD and diabesity relative to male mice, accompanied by differential regulation of hepatic lipocalin prostaglandin D2 synthase.

From adiposity to steatosis: metabolic dysfunction-associated steatotic liver disease, a hepatic expression of metabolic syndrome - current insights and future directions

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a growing health concern and the risk of its development is connected with the increasing prevalence of metabolic syndrome (MetS) which occurs as a result of some complex obesity-induced metabolic changes. It is a common chronic liver disease characterized by excessive fat accumulation in the liver, the tendency to progress to more severe forms, and a corresponding increase in morbidity and mortality. Thus, effectively addressing the rising burden of the disease requires a thorough understanding of its complex interrelationship with obesity and MetS.

MAIN BODY

MASLD results from complex interactions involving obesity, insulin resistance, and dyslipidaemia, leading to hepatic lipid accumulation, and is influenced by several genetic and environmental factors such as diet and gut microbiota dysbiosis. It has extensive metabolic and non-metabolic implications, including links to MetS components like hyperglycaemia, hypertension, and dyslipidaemia, and progresses to significant liver damage and other extra-hepatic risks like cardiovascular disease and certain cancers. Diagnosis often relies on imaging and histology, with non-invasive methods preferred over liver biopsies. Emerging biomarkers and OMIC technologies offer improved diagnostic capabilities but face practical challenges. Advancements in artificial intelligence (AI), lifestyle interventions, and pharmacological treatments show promise, with future efforts focusing on precision medicine and novel diagnostic tools to improve patient outcome.

CONCLUSION

Understanding the pathogenic mechanisms underlying the development of MASLD within the context of metabolic syndrome (MetS) is essential for identifying potential therapeutic targets. Advancements in non-invasive diagnostic tools and novel pharmacological treatments, hold promise for improving the management of MASLD. Future research should focus on precision medicine and innovative therapies to effectively address the disease and its consequences.

Protective effects of sulfated polysaccharides from Enteromorpha intestinalis on oxidative stress, liver iron overload and Ferroptosis in Zebra fish exposed to ethanol

The study investigates the protective effects of sulfated polysaccharides extracted from Enteromorpha intestinalis (EIP) against oxidative stress, liver iron overload, and ferroptosis in zebrafish exposed to ethanol, a model for alcohol-related liver disease (ALD). The extracted polysaccharides were characterized for sulfate and sugar content, molecular weight, and functional groups. Adult male zebrafish were divided into three groups: control, ethanol-exposed (EE) (0.2 % ethanol (v/v) in the water), and ethanol-exposed with EIP supplementation (1 % EIP incorporated into the basal diet) (EE+EIP) for 30 days. The study measured liver oxidative stress indexes, serum enzymological indexes, liver and serum lipid profiles, liver iron ion content, and expression of ferroptosis-related genes. Histological analysis was conducted to assess lipid accumulation and iron deposition in liver tissues. The findings indicate that EIP supplementation significantly mitigates ethanol-induced liver damage. Specifically, EIP reduced malondialdehyde levels, increased antioxidant enzyme and non-enzymatic antioxidant activity, and decreased iron ion accumulation and the area of iron granules in the liver tissue. Additionally, EIP treatment lowered lipids levels and aminotransferase enzyme activity in the serum. In the ALD model, EIP inhibited ethanol-induced ferroptosis by modulating the expression of key genes: it decreased the expression of transferrin (tf), transferrin receptor (tfr), ferroportin (fpn), and ferritin heavy chain (fth), while increasing the expression of glutathione peroxidase 4 (gpx4) and solute carrier family 7 member 11 (slc7a11). EIP has protective effects against ethanol-induced liver injury in zebrafish, offering a foundation for further research into its hepatoprotective action and potential application in preventing and treating ALD.

Additive effect of metabolic dysfunction-associated fatty liver disease on left ventricular function and global strain in type 2 diabetes mellitus patients: a 3.0 T cardiac magnetic resonance feature tracking study

BACKGROUND

Type 2 diabetes mellitus (T2DM) and metabolic-associated fatty liver disease (MAFLD) are both metabolic disorders that negatively impact the cardiovascular system. This study comprehensively analyzed the additive effect of MAFLD on left ventricular function and global strain in T2DM patients by cardiac magnetic resonance (CMR).

METHODS

Data of 261 T2DM patients, including 109 with and 152 without MAFLD, as well as 73 matched normal controls from our medical center between June 2015 and March 2022 were retrospectively analyzed. CMR-derived parameters, including LV function and global strain parameters, were compared among different groups. Univariate and multivariate linear regression analyses were conducted to investigate the impact of various factors on LV function and global strain.

RESULTS

Our investigation revealed a progressive deterioration in LV functional parameters across three groups: control subjects, T2DM patients without MAFLD, and T2DM patients with MAFLD. Statistically significant increases in left ventricular end-diastolic volume index (LVEDVI), left ventricular end-systolic volume index (LVESVI), left ventricular mass index (LVMI) were observed, along with decreases in left ventricular ejection fraction (LVEF) and left ventricular global function index (LVGFI). Among these three groups, significant reductions were also noted in the absolute values of LV global radial, circumferential, and longitudinal peak strains (GRPS, GCPS, and GLPS), as well as in peak systolic (PSSR) and peak diastolic strain rates (PDSR). MAFLD was identified as an independent predictor of LVEF, LVMI, LVGFI, GRPS, GCPS, and GLPS in multivariate linear analysis. Besides, the incidence of late gadolinium enhancement was higher in MAFLD patients than in non-MAFLD patients (50/109 [45.9%] vs. 42/152 [27.6%], p = 0.003). Furthermore, escalating MAFLD severity was associated with a numerical deterioration in both LV function parameters and global strain values.

CONCLUSIONS

This study thoroughly compared CMR parameters in T2DM patients with and without MAFLD, uncovering MAFLD's adverse impact on LV function and deformation in T2DM patients. These findings highlight the critical need for early detection and comprehensive management of cardiac function in T2DM patients with MAFLD.

Interleukin-mediated therapies in liver diseases and comorbidity effects

Cytokines like interleukins (ILs) play important roles in inflammation and innate immune. Yang and Zhang carried out an interesting study related to ILs and hepatic diseases. They described the role of ILs in the pathogenesis and resolution of hepatic disorders. The authors summarized alcohol-related liver disease and virus-induced hepatitis, as far as clinical studies a fortiori carried out on IL-mediated treatments pertaining to these dysfunctions. This editorial contributes to the review by Yang and Zhang titled, "Interleukins in liver disease treatment", and focuses on therapies mediated by ILs in comorbid liver diseases. The documentary search was conducted on recent pertinent literature, primarily using the Google Scholar and PubMed databases.

Bile acid metabolism and signaling in health and disease: molecular mechanisms and therapeutic targets

Bile acids, once considered mere dietary surfactants, now emerge as critical modulators of macronutrient (lipid, carbohydrate, protein) metabolism and the systemic pro-inflammatory/anti-inflammatory balance. Bile acid metabolism and signaling pathways play a crucial role in protecting against, or if aberrant, inducing cardiometabolic, inflammatory, and neoplastic conditions, strongly influencing health and disease. No curative treatment exists for any bile acid influenced disease, while the most promising and well-developed bile acid therapeutic was recently rejected by the FDA. Here, we provide a bottom-up approach on bile acids, mechanistically explaining their biochemistry, physiology, and pharmacology at canonical and non-canonical receptors. Using this mechanistic model of bile acids, we explain how abnormal bile acid physiology drives disease pathogenesis, emphasizing how ceramide synthesis may serve as a unifying pathogenic feature for cardiometabolic diseases. We provide an in-depth summary on pre-existing bile acid receptor modulators, explain their shortcomings, and propose solutions for how they may be remedied. Lastly, we rationalize novel targets for further translational drug discovery and provide future perspectives. Rather than dismissing bile acid therapeutics due to recent setbacks, we believe that there is immense clinical potential and a high likelihood for the future success of bile acid therapeutics.

Network pharmacological analysis on the mechanism of Linggui Zhugan decoction for nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD), represents a chronic progressive disease that imposes a significant burden on patients and the healthcare system. Linggui Zhugan decoction (LGZGD) plays a substantial role in treating NAFLD, but its exact molecular mechanism is unknown. Using network pharmacology, this study aimed to investigate the mechanism of action of LGZGD in treating NAFLD. Active ingredients and targets were identified through the integration of data from the TCMSP, GEO, GeneCards, and OMIM databases. Cytoscape 3.9.1 software, in conjunction with the STRING platform, was employed to construct network diagrams and screen core targets. The enrichment analysis of gene ontology and the Kyoto Encyclopedia of Genes and Genomes pathways were conducted by using the R. Molecular docking of the active ingredients and core targets was performed with AutoDock Vina software. We obtained 93 and 112 active ingredients and potential targets using the bioinformatic analysis of LGZGD in treating NAFLD. The primary ingredients of LGZGD included quercetin, kaempferol, and naringenin. The core targets were identified AKT1, MYC, HSP90AA1, HIF1A, ESR1, TP53, and STAT3. Gene ontology function enrichment analysis revealed associations with responses to nutrient and oxygen levels, nuclear receptor activity, and ligand-activated transcription factor activity. Kyoto Encyclopedia of Genes and Genomes signaling pathway analysis implicated the involvement of the PI3K-Akt, IL-17, TNF, Th17 cell differentiation, HIF-1, and TLR signaling pathways. Molecular docking studies indicated strong binding affinities between active ingredients and targets. LGZGD intervenes in NAFLD through a multi-ingredient, multi-target, and multi-pathway approach. Treatment with LGZGD can improve insulin resistance, oxidative stress, inflammation, and lipid metabolism associated with NAFLD.

NAFLD Fibrosis Progression and Type 2 Diabetes: The Hepatic-Metabolic Interplay

The bidirectional relationship between type 2 diabetes and (non-alcoholic fatty liver disease) NAFLD is indicated by the higher prevalence and worse disease course of one condition in the presence of the other, but also by apparent beneficial effects observed in one, when the other is improved. This is partly explained by their belonging to a multisystemic disease that includes components of the metabolic syndrome and shared pathogenetic mechanisms. Throughout the progression of NAFLD to more advanced stages, complex systemic and local metabolic derangements are involved. During fibrogenesis, a significant metabolic reprogramming occurs in the hepatic stellate cells, hepatocytes, and immune cells, engaging carbohydrate and lipid pathways to support the high-energy-requiring processes. The natural history of NAFLD evolves in a variable and dynamic manner, probably due to the interaction of a variable number of modifiable (diet, physical exercise, microbiota composition, etc.) and non-modifiable (genetics, age, ethnicity, etc.) risk factors that may intervene concomitantly, or subsequently/intermittently in time. This may influence the risk (and rate) of fibrosis progression/regression. The recognition and control of the factors that determine a rapid progression of fibrosis (or its regression) are critical, as the fibrosis stages are associated with the risk of liver-related and all-cause mortality.

Pharmacological therapy of metabolic dysfunction-associated steatotic liver disease-driven hepatocellular carcinoma

In light of a global rise in the number of patients with type 2 diabetes mellitus (T2DM) and obesity, non-alcoholic fatty liver disease (NAFLD), now known as metabolic dysfunction-associated fatty liver disease (MAFLD) or metabolic dysfunction-associated steatotic liver disease (MASLD), has become the leading cause of hepatocellular carcinoma (HCC), with the annual occurrence of MASLD-driven HCC expected to increase by 45%-130% by 2030. Although MASLD has become a serious major public health threat globally, the exact molecular mechanisms mediating MASLD-driven HCC remain an open problem, necessitating future investigation. Meanwhile, emerging studies are focusing on the utility of bioactive compounds to halt the progression of MASLD to MASLD-driven HCC. In this review, we first briefly review the recent progress of the possible mechanisms of pathogenesis and progression for MASLD-driven HCC. We then discuss the application of bioactive compounds to mitigate MASLD-driven HCC through different modulatory mechanisms encompassing anti-inflammatory, lipid metabolic, and gut microbial pathways, providing valuable information for future treatment and prevention of MASLD-driven HCC. Nonetheless, clinical research exploring the effectiveness of herbal medicines in the treatment of MASLD-driven HCC is still warranted.

Decreased FXR Agonism in the Bile Acid Pool Is Associated with Impaired FXR Signaling in a Pig Model of Pediatric NAFLD

The objective of this study was to investigate whether the impairment of farnesoid X receptor (FXR)-fibroblast growth factor 19 (FGF19) signaling in juvenile pigs with non-alcoholic fatty liver disease (NAFLD) is associated with changes in the composition of the enterohepatic bile acid pool. Eighteen 15-day-old Iberian pigs, pair-housed in pens, were allocated to receive either a control (CON) or high-fructose, high-fat (HFF) diet. Animals were euthanized in week 10, and liver, blood, and distal ileum (DI) samples were collected. HFF-fed pigs developed NAFLD and had decreased FGF19 expression in the DI and lower FGF19 levels in the blood. Compared with the CON, the HFF diet increased the total cholic acid (CA) and the CA to chenodeoxycholic acid (CDCA) ratio in the liver, DI, and blood. CA and CDCA levels in the DI were negatively and positively correlated with ileal FGF19 expression, respectively, and blood levels of FGF19 decreased with an increasing ileal CA to CDCA ratio. Compared with the CON, the HFF diet increased the gene expression of hepatic 12-alpha-hydrolase, which catalyzes the synthesis of CA in the liver. Since CA species are weaker FXR ligands than CDCA, our results suggest that impairment of FXR-FGF19 signaling in NAFLD pigs is associated with a decrease in FXR agonism in the bile acid pool.

Depletion of Igfbp7 alleviates zebrafish NAFLD progression through inhibiting hepatic ferroptosis

AIMS

The global increased expression of Insulin-like growth factor binding protein 7 (IGFBP7) has been detected in non-alcoholic fatty liver disease (NAFLD) patients, however, its roles in NAFLD and the mechanism remain largely unclear. The goal of this study is to investigate the effect and mechanism of Igfbp7 using a zebrafish NAFLD model.

MAIN METHODS

The igfbp7-/- null zebrafish mutant and the Igfbp7 liver overexpressed (LOE) transgenic zebrafish based on Gal4/UAS system were generated by CRISPR/Cas9 and Tol2 transgenic technique, respectively. The zebrafish NAFLD models in wildtypes, igfbp7-/- mutants and Igfbp7 LOE fishes have been established by high-fat diet feeding. The Igfbp7 dynamic expression and its effects on NAFLD progression have been detected and analyzed in both human NAFLD patients and zebrafish models. And the potential mechanism has been investigated through transcriptome analysis and subsequent detection and verification.

KEY FINDINGS

High Igfbp7 levels in NASH and fibrosis stages have been detected in liver tissues of both human NAFLD patients and zebrafish models. Depletion of Igfbp7 significantly alleviated liver steatosis, inflammation, and fibrosis, whereas liver specific Igfbp7 overexpression dramatically exacerbated liver fibrosis in zebrafish NAFLD model. The hepatic iron deposition, lipid peroxidation products, and ferroptosis-related index were also significantly reduced at the NASH stage in the absence of Igfbp7. Igfbp7 promotes NAFLD progression through regulating ferroptosis, and Ncoa4-mediated ferritinophagy may be the pathway of Igfbp7-regulated ferroptosis.

SIGNIFICANCE

Igfbp7 is confirmed as an important regulator in NAFLD progression. Depleting Igfbp7 effectively alleviates zebrafish NAFLD progression by inhibiting hepatic ferroptosis, suggesting a novel potential target for NAFLD treatment.

Giant mitochondria in human liver disease

This thematic review aims to provide an overview of the current state of knowledge about the occurrence of giant mitochondria or megamitochondria in liver parenchymal cells. Their presence and accumulation are considered to be a major pathological hallmark of the health and fate of liver parenchymal cells that leads to overall tissue deterioration and eventually results in organ failure. The first description on giant mitochondria dates back to the 1960s, coinciding with the availability of the first generation of electron microscopes in clinical diagnostic laboratories. Detailed accounts on their ultrastructure have mostly been described in patients suffering from alcoholic liver disease, chronic hepatitis, hepatocellular carcinoma and non-alcoholic fatty liver disease. Interestingly, from this extensive literature survey, it became apparent that giant mitochondria or megamitochondria present themselves with or without highly organised crystal-like intramitochondrial inclusions. The origin, formation and potential role of giant mitochondria remain to-date largely unanswered. Likewise, the biochemical composition of the well-organised crystal-like inclusions and their possible impact on mitochondrial function is unclear. Herein, concepts about the possible mechanism of their formation and three-dimensional architecture will be approached. We will furthermore discuss their importance in diagnostics, including future research outlooks and potential therapeutic interventions to cure liver disease where giant mitochondria are implemented.

Mechanism for FXR to regulate bile acid and glycolipid metabolism to improve NAFLD

Nonalcoholic fatty liver disease (NAFLD) is the main cause of chronic liver disease, with liver metabolic disorders as major pathological changes, manifested as abnormal lipid accumulation, liver cell oxidative stress, etc., but its etiology is still unclear. The farnesol X receptor (FXR) is a major bile acid receptor in the "gut-liver axis", via which FXR regulates metabolism and affects the pathophysiological status of various substances through different pathways, thus contributing to the occurrence and development of NAFLD. Therefore, FXR has become a potential therapeutic target for NAFLD. This article reviews the relationship between FXR regulation of bile acid, glucose, and lipid metabolism through the "gut-liver axis" and the occurrence and development of NAFLD, to provide new insights and clues for further research about FXR-based pharmaceutical treatments.

Effects of (20 R)-Panaxadiol on NAFLD using non‑targeted metabolomics in stool

Non-alcoholic fatty liver disease (NAFLD) is a clinical syndrome characterized by hepatocyte steatosis and adipose accumulation with the main lesion in the hepatic lobule, but without a history of excessive alcohol consumption. NAFLD ranges from nonalcoholic fatty liver (NAFL) to nonalcoholic steatohepatitis (NASH), and may further accumulate fibrosis leading to cirrhosis. Many studies have found that ginseng can treat NAFLD. (20 R)-Panaxadiol (PD) is a panax ginseng diol type compound, has been proved that can treat the obesity. This study wants to investigate the effect of PD on non-alcoholic liver disease. We used 20 ob/ob mice and 10 C57BL/6 J mice. C57BL/6 J mice as CONTROL group, ob/ob mice were divided into model group and PD group. In PD group, ob/ob mice were treated with PD for eight weeks(10 mg/kg, the CON and OB group was given the same amount of sodium carboxymethyl cellulose), detected the weight, food intake and serum index, observed the HE staining of liver and intestine, performed the 16 S rRNA and untargeted metabolomics analysis used mice feces, and verify the results by detect the expression of TNF-α, MDA and SOD. In vivo results, PD can improve abnormal glucose and lipid metabolism and liver function. In 16 S rRNA result, we found beneficial bacteria Muribaculaceae and Lactobacillus increased; in untargeted metabolomics analysis, inflammatory metabolites prostaglandin (PG) and lipopolysaccharide (LPS) decreased, antioxidant metabolites FAD and lipoic acid increased. Then, we proceeded the association analysis of gut microbiota and metabolites, the result showed gut microbiota have strongly associated with anti-inflammatory and antioxidant metabolites. In addition, PD improves intestinal wall integrity. Meanwhile, the expression of TNF-α、MDA and SOD were detected, it was verified that PD has the effect of antioxidant and anti-inflammation. Our study showed that PD, as an active ingredient of ginseng, can play an anti-inflammatory and antioxidant role by improving intestinal metabolites, thereby preventing and treating non-alcoholic fatty liver disease to a certain extent.

SIRT1 Activator E1231 Alleviates Nonalcoholic Fatty Liver Disease by Regulating Lipid Metabolism

Nonalcoholic fatty liver disease (NAFLD) is one of the most common liver diseases. Silencing information regulator 1 (SIRT1) was demonstrated to modulate cholesterol and lipid metabolism in NAFLD. Here, a novel SIRT1 activator, E1231, was studied for its potential improvement effects on NAFLD. C57BL/6J mice were fed a high-fat and high-cholesterol diet (HFHC) for 40 weeks to create a NAFLD mouse model, and E1231 was administered by oral gavage (50 mg/kg body weight, once/day) for 4 weeks. Liver-related plasma biochemistry parameter tests, Oil Red O staining, and hematoxylin-eosin staining results showed that E1231 treatment ameliorated plasma dyslipidemia, plasma marker levels of liver damage (alanine aminotransferase (ALT) and aspartate aminotransferase (AST)), liver total cholesterol (TC) and triglycerides (TG) contents, and obviously decreased hepatic steatosis score and NAFLD Activity Score (NAS) in the NAFLD mouse model. Western blot results showed that E1231 treatment significantly regulated lipid-metabolism-related protein expression. In particular, E1231 treatment increased SIRT1, PGC-1α, and p-AMPKα protein expression but decreased ACC and SCD-1 protein expression. Additionally, in vitro studies demonstrated that E1231 inhibited lipid accumulation and improved mitochondrial function in free-fatty-acid-challenged hepatocytes, and required SIRT1 activation. In conclusion, this study illustrated that the SIRT1 activator E1231 alleviated HFHC-induced NAFLD development and improved liver injury by regulating the SIRT1-AMPKα pathway, and might be a promising candidate compound for NAFLD treatment.

Type 2 diabetes complications are associated with liver fibrosis independent of hemoglobin A1c

INTRODUCTION AND OBJECTIVES

The association between type 2 diabetes, non-alcoholic fatty liver disease, and liver fibrosis is well established, but it is unknown whether complications of type 2 diabetes influence fibrosis levels. We defined the complications of type 2 diabetes by the presence of diabetic nephropathy, retinopathy, or neuropathy and aimed to evaluate their association with the degree of liver fibrosis measured by the fibrosis-4 (FIB-4) index.

MATERIALS AND METHODS

This is a cross-sectional study evaluating the association of type 2 diabetes complications with liver fibrosis. A total of 2389 participants were evaluated from a primary care practice. FIB-4 was evaluated as a continuous and categorical measure using linear and ordinal logistic regression.

RESULTS

Patients with complications were older, had higher hemoglobin A1c, and a higher median FIB-4 score (1.34 vs. 1.12, P<0.001). On adjusted analysis, type 2 diabetes complications were associated with higher fibrosis by continuous FIB-4 score (Beta-coefficient: 0.23, 95% confidence interval [CI]: 0.004-1.65) and demonstrated increased odds of fibrosis by categorical FIB-4 score (odds ratio [OR]: 4.48, 95% CI: 1.7-11.8, P=0.003), independent of hemoglobin A1c level.

CONCLUSIONS

The presence of type 2 diabetes complications is associated with the degree of liver fibrosis, independent of hemoglobin A1c level.