Pathogenesis of non-alcoholic fatty liver disease in children and adolescence: From “two hit theory” to “multiple hit model”

A comparative study on the effect of melatonin and orlistat combination versus orlistat alone on high fat diet-induced hepatic changes in the adult male albino rats (a histological and morphometric study)

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is the extremely usual reason of chronic liver disease, extending from simple hepatic steatosis (HS), nonalcoholic steatohepatitis (NASH) to advanced hepatic fibrosis and cirrhosis. Though orlistat is a Food and Drug Administration (FDA) approved drug for long-duration management of obesity, few cases of severe hepatic insult were declared. Melatonin is an efficient antioxidant; it also regulates metabolic processes that lead to fat accumulation and obesity.

AIM OF THE WORK

The current research aimed to compare the impact of orlistat, melatonin, and their combination on the structural changes of the hepatic tissue of adult male albino rats supplied with high fat diet (HFD).

MATERIAL AND METHODS

Thirty adult male albino rats divided into five groups. Liver specimens were divided into two parts. One-half was processed to obtain paraffin blocks, and the other half was processed to obtain semithin sections. Morphometric study and statistical analysis were done.

RESULTS

Hepatic tissue from the HFD group showed steatosis, ballooning, and inflammation and all these parameters were moderately improved - except for inflammation which worsened with therapy. Combined orlistat and melatonin-treated groups showed marked improvement of all parameters as well as marked improvement in the hepatic fibrosis.Orlistat/Melatonin combination therapy is both safe and effective in comparison to orlistat and melatonin monotherapy.

Can fecal calprotectin be used as a biomarker of non-alcoholic fatty liver disease in obese adolescents?

BACKGROUND

The incidence of non-alcoholic fatty liver disease (NAFLD) is increasing with obesity, and it is believed that the ongoing low-grade inflammation in obesity and alterations in the enterohepatic axis contributing this process. This study aimed to determine the role of fecal calprotectin (FC) as inflammatory biomarker in obesity and NAFLD.

METHODS

Between November 2022-August 2023, 31 obese and 10 healthy adolescents aged between 10 and 18 years enrolled in this prospective controlled study. Body mass index higher than 2 standard deviation is considered as obesity. Obese adolescents were divided into two subgroups: obese adolescents (n = 11) and Obese + NAFLD group (n = 20). NAFLD diagnosis was made with biochemical analysis or ultrasonography. FC levels and laboratory parameters analyzed in study group, while only FC samples taken from control group. Anthropometric and laboratory parameters were compared between groups. This study was registered in ClinicalTrials.gov (NCT06229184).

RESULTS

The median (IQR P25-75) FC levels in the obese + NAFLD, obese and the healthy controls were 136.23 (43.36-332.04), 61.77 (29.70-285.92) and 38.95 (27.59-50.52) µg/g feces, respectively (p = 0.018). Subgroup analyses revealed that the significant difference was between the obese + NAFLD group and the control group (p = 0.02), while no significant differences were observed between the control and obese groups, or between the obese and obese + NAFLD groups. FC positivity rates were 20% (n = 2) in the control group, 54.5% (n = 6) in the obese group, and 75% (n = 15) in the Obese + NAFLD group (p = 0.018).

CONCLUSIONS

FC is significantly higher in obese adolescents compared to healthy peers, but no significant difference was observed between obese and obese + NAFLD groups. Further studies needed on this subject.

TRIAL REGISTRATION

This trial is registered in ClinicalTrials.gov (Trial registration number [ClinicalTrials.gov ID] NCT06229184).

Ganoderma lucidum Spore Powder Alleviates Metabolic-Associated Fatty Liver Disease by Improving Lipid Accumulation and Oxidative Stress via Autophagy

Lipid accumulation and oxidative stress, which could be improved by autophagy, are the "hits" of metabolic-associated fatty liver disease (MAFLD). Ganoderma lucidum spore powder (GLSP) has the effect of improving liver function. However, there are few reports about its effects on and mechanisms impacting MAFLD alleviation. This study investigated the effect of GLSP on hepatic lipid accumulation and oxidative stress and explored the role that autophagy played in this effect. The results showed that GLSP effectively reduced lipid accumulation and activated autophagy in the livers of mice with high-fat-diet-induced disease and palmitic acid-induced hepatocytes. GLSP reduced the lipid accumulation by reducing lipogenesis and promoting lipid oxidation in HepG2 cells. It decreased the production of ROS, increased the activity of SOD and CAT, and improved the mitochondrial membrane potential via the Keap1/Nrf2 pathway. The alleviating effects of GLSP on the lipid accumulation and oxidative stress was reversed by 3-methyladenine (3-MA), an autophagy inhibitor. GLSP activated autophagy via the AMPK pathway in HepG2 cells. In conclusion, GLSP could attenuate MAFLD by the improvement of lipid accumulation and oxidative stress via autophagy. This paper is the first to report the improvement of MAFLD through autophagy promotion. It will shed novel light on the discovery of therapeutic strategies targeting autophagy for MAFLD.

Therapeutic potential of palmitoleic acid in non-alcoholic fatty liver disease: Targeting ferroptosis and lipid metabolism disorders

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a metabolic syndrome associated with obesity and type 2 diabetes mellitus. Currently, there are no effective drugs to treat NAFLD. Palmitoleic acid (PA) has demonstrated therapeutic potential in managing various metabolic diseases and inflammation. Although ferroptosis is known to play a critical role in the NAFLD development, it remains unclear whether PA can alleviate NAFLD by inhibiting ferroptosis.

METHODS

Thirty C57BL/6 mice were divided into three groups: standard diet, high-fat diet (HFD), and HFD with PA. The experiment lasted 16 weeks.

RESULTS

PA alleviated liver injury, hepatitis, and dyslipidemia in HFD-induced NAFLD mice. It improved insulin resistance, downregulated genes and proteins related to fat synthesis, and upregulated genes and proteins linked to lipolysis and fat oxidation. Mechanistically, bioinformatics enrichment revealed the involvement of ferroptosis in NAFLD. PA mitigated oxidative stress and reduced liver iron content in NAFLD. It downregulated acyl-CoA synthetase long-chain family member 4 (ACSL4) expression while upregulating glutathione peroxidase 4 (GPX4) and solute carrier family 7 member 11 (SLC7A11) expression, thereby inhibiting ferroptosis.

CONCLUSION

PA exerts a protective effect against liver lipotoxicity by inhibiting lipid metabolism-mediated ferroptosis. These findings provide new insights into preventive and therapeutic strategies for the pathological processes of NAFLD.

Protocol for a Longitudinal Cohort Study to Understand Characteristics and Risk Factors Underlying Vibration-Controlled Transient Elastography-Diagnosed Metabolic Dysfunction-Associated Fatty Liver Disease Children

Background

Metabolic-associated steatotic liver disease (MASLD) is a novel term proposed in 2023 to replace non-alcoholic fatty liver disease (NAFLD) with the aim of better reflecting its pathogenesis and clinical manifestations. Vibration-controlled transient elastography (VCTE) is an evidence-based, non-invasive imaging device used to evaluate liver fat deposition and fibrosis. It can effectively detect liver fat infiltration greater than 5%, which is much higher than the previous ultrasound detection rate (it is difficult to detect liver fat deposition below 30%). Nevertheless, the prevalence and characteristics of MASLD children diagnosed based on these updated criteria are currently not well established.

Methods

Currently, a prospective multi-center population-based cohort study is being conducted in Wuxi, China, spanning from 2023 to 2035, involving 5600 children from four primary schools. Throughout the study's baseline and follow-up periods, yearly physical examinations, laboratory tests, VCTE assessments, and bioelectrical impedance analysis are being conducted to measure MASLD-related biomarkers. Additionally, a questionnaire is being administered to inquire about dietary habits. MASLD is being diagnosed based on clinical and laboratory criteria, and the corresponding prevalence is being assessed.

Results

Recruitment began in March 13, 2023. To date, 1475 participants have completed the physical examination and questionnaire survey.

Discussion

Our study investigated the prevalence of MASLD and its influencing factors in Chinese school-age children and adolescents. By collecting and analyzing data from physical examinations and survey questionnaires, it may propose new avenues for guiding the treatment and early-stage prevention of MASLD in children.

Trial Registration

Chinese Clinical Trials Registry (NO. ChiCTR2400080508).

Caveolin-1 ameliorates hepatic injury in non-alcoholic fatty liver disease by inhibiting ferroptosis via the NOX4/ROS/GPX4 pathway

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease globally, with a complex and contentious pathogenesis. Caveolin-1 (CAV1) is an important regulator of liver function and can mitigate liver injury by scavenging reactive oxygen species (ROS). Evidence suggests that NOX4 is a source of ROS production, that oxidative stress and ferroptosis are closely related, and that both are involved in the onset and progression of NAFLD. However, whether CAV1 attenuates liver injury in NAFLD caused by high-fat diet via the NOX4/ROS/GPX4 pathway remains unclear. An in vivo fatty liver model was established by feeding mice with a high-fat diet for 16 weeks. In addition, an in vitro fatty liver model was established by incubating AML-12 cells with free fatty acids for 24 h using an in vitro culture method. In our study, it was observed that a high-fat diet induces mitochondrial damage and worsens oxidative stress in NAFLD. This diet also hinders GPX4 expression, leading to an escalation of ferroptosis and lipid accumulation. To counteract these effects, intraperitoneal administration of CSD peptide in mice attenuated the high-fat diet-induced liver mitochondrial damage and ferroptosis. Likewise, overexpression of CAV1 resulted in an increase in GPX4 expression and a reduction in levels of ROS-mediated iron metamorphosis, thus mitigating the progression of the disease. However, the effects of CAV1 on GPX4-mediated ferroptosis and lipid deposition could be reversed by CAV1 small interfering RNA (SiRNA). Finally, NOX4 inhibitor (GLX351322) treatment increased CAV1 siRNA-mediated GPX4 expression and decreased the level of ROS-mediated ferroptosis. These findings suggest a potential mechanism underlying the protective role of CAV1 against high-fat diet-induced hepatotoxicity in NAFLD, shedding new light on the interplay between CAV1, GPX4, and ferroptosis in liver pathology.

Bile acid disorders and intestinal barrier dysfunction are involved in the development of fatty liver in laying hens

The pathogenesis of fatty liver is highly intricate. The role of the gut-liver axis in the development of fatty liver has gained increasing recognition in recent years. This study was conducted to explore the role of bile acid signaling and gut barrier in the pathogenesis of fatty liver. A total of 100 "Jing Tint 6" laying hens, 56-week-old, were used and fed basal diets until 60 weeks of age. At the end of the experiment, thirty individuals were selected based on the degree of hepatic steatosis. The hens with minimal hepatic steatosis (< 5 %) were chosen as healthy controls, while those with severe steatosis (> 33 %) in the liver were classified as the fatty liver group. Laying hens with fatty liver and healthy controls showed significant differences in body weight, liver index, abdominal fat ratio, feed conversion ratio (FCR), albumin height, Haugh unit, and biochemical indexes. The results of bile acid metabolomics revealed a clear separation in hepatic bile acid profiles between the fatty liver group and healthy controls, and multiple secondary bile acids were decreased in the fatty liver group, indicating disordered bile acid metabolism. Additionally, the mRNA levels of farnesoid X receptor (FXR) and genes related to bile acid transport were significantly decreased in both the liver and terminal ileum of hens with fatty liver. Moreover, the laying hens with fatty liver exhibited significant decreases in ileal crypt depth, the number of goblet cells, and the mRNA expression of tight junction-related proteins, alongside a significant increase in ileal permeability. Collectively, these findings suggest that disordered bile acids, suppressed FXR-mediated signaling, and impaired intestinal barrier function are potential factors promoting the development of fatty liver. These insights indicate that regulating bile acids and enhancing intestinal barrier function may become new preventive and therapeutic strategies for fatty liver in the near future.

Metabolic-associated steatotic liver disease and hepatocellular carcinoma

INTRODUCTION

Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) has been introduced as a superior term to describe steatosis on a background of metabolic dysregulation and is slated to become the leading cause of HCC worldwide, as the incidence of metabolic comorbidities is increasing. As such, MASLD has evolved into an important public health issue, potentially leading to higher rates of liver mortality and end-stage liver disease. To this end, understanding the association between MASLD and HCC may allow for the identification of better interventions and novel therapeutic strategies.

AREAS COVERED

The authors provide a review of current knowledge on HCC development among patients with MASLD, with insights into molecular pathways and current and future therapeutic strategies.

EXPERT OPINION

MASLD has a strong association with the risk of HCC development, as metabolic comorbidities induce dysregulation in molecular pathways, leading to insulin-resistance, oxidative stress, and chronic inflammation, thus causing progression to cirrhosis and eventually to HCC. Therapeutic strategies focused on reducing diabetes-associated complications, as well as the prevalence of obesity and smoking can improve patient outcomes and reduce HCC incidence. Future studies on the molecular background of metabolic alterations may help devise new therapeutic approaches aiming to improve the current management of MASLD-HCC.

Mechanism of epigallocatechin gallate in treating non-alcoholic fatty liver disease: Insights from network pharmacology and experimental validation

To explore the therapeutic effects along with the molecular mechanisms of epigallocatechin gallate (EGCG) in non-alcoholic fatty liver disease (NAFLD) treatment using network pharmacology as well as animal experiments. Firstly, the Traditional Chinese Medicine (TCM) Systems Pharmacology Database was searched to identify the potential targets of EGCG. The DisGeNET Database was used to screen the potential targets of NAFLD. The GeneCards Database was searched to identify related genes involved in pyroptosis. Subsequently, the intersecting genes of EGCG targeting pyroptosis to regulate NAFLD were obtained using a Venn diagram. Simultaneously, the aforementioned intersecting genes were used to construct a drug-disease target protein-protein interaction (PPI) network. The DAVID database was adopted for Gene Ontology (GO) as well as Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. The main pathway-target network was determined. Next, the potential mechanism of EGCG targeting pyroptosis to regulate NAFLD was investigated and validated through in vivo experiments. 626 potential targets of EGCG, 447 target genes of NAFLD, and 568 potential targets of pyroptosis were identified. The number of common targets between EGCG, NAFLD, and pyroptosis was 266. GO biological process items and 92 KEGG pathways were determined based on the analysis results. Animal experiments demonstrated that EGCG could ameliorate body weight, glucolipid metabolism, steatosis, and liver injury, enhance insulin sensitivity, and improve glucose tolerance in NAFLD mice through the classical pathway of pyroptosis. EGCG could effectively treat NAFLD through multiple targets and pathways. It was concluded that EGCG ameliorates hepatocyte steatosis, pyroptosis, dyslipidemia, and inflammation in NAFLD mice fed a high-fat diet (HFD), and the protective mechanism could be associated with the NLRP3-Caspase-1-GSDMD classical pyroptosis pathway.

Ultra-Processed Food Consumption and Cardiometabolic Risk Factors in Children Living in Northeastern Brazil

OBJECTIVE

To analyze the association between ultra-processed food (UPF) consumption and cardiometabolic, biochemical, and inflammatory risk factors in children in a metropolis in Northeast Brazil.

METHODS

A cross-sectional study using baseline data from a community-based controlled trial was carried out with 151 children from public schools in João Pessoa, Paraíba, Brazil aged 7 to 10 years. Dietary consumption was assessed using 24 h food recall, and UPF consumption was estimated using the NOVA classification system. Anthropometry (BMI for age), blood pressure, biochemical parameters (ALT, AST, GGT, cholesterol, LDL-c, HDL-c, triglycerides, fasting glucose, HbA1c, HOMA-IR, creatinine, urea, hs-CRP), and cytokines (IL-2, IL-4, IL-6, IL-10, IL-17a, IFN-γ, and TNF-α) were also assessed.

RESULTS

Children in the third tertile (highest UPF consumption) had higher serum concentrations of LDL-c (p-value = 0.04) and ALT (p-value = 0.01), with a trend towards higher AST (p-value = 0.06). Total energy (p-value = 0.01), trans fatty acid (p-value = 0.02), and sodium (p-value = 0.04) intakes were higher in the highest tertile, whereas protein (p-value < 0.01) and fiber (p-value < 0.01) intakes were lower. Concentrations of IL-17A (p-value = 0.01) and IL-10 (p-value = 0.04) were significantly higher in the second tertile. Multiple linear regression showed that UPF consumption was significantly associated with increased LDL-c, ALT, and AST concentrations.

CONCLUSIONS

High intake of UPFs was associated with dyslipidemia, elevated liver enzymes, and inflammatory changes in children. Dietary interventions are needed to reduce UPF consumption and prevent cardiometabolic and liver disease in childhood.

Application and mechanism of Chinese herb medicine in the treatment of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a chronic liver condition closely associated with metabolic syndrome, with its incidence rate continuously rising globally. Recent studies have shown that the development of NAFLD is associated with insulin resistance, lipid metabolism disorder, oxidative stress and endoplasmic reticulum stress. Therapeutic strategies for NAFLD include lifestyle modifications, pharmacological treatments, and emerging biological therapies; however, there is currently no specific drug to treat NAFLD. However Chinese herb medicine (CHM) has shown potential in the treatment of NAFLD due to its unique therapeutic concepts and methods for centuries in China. This review aims to summarize the pathogenesis of NAFLD and some CHMs that have been shown to have therapeutic effects on NAFLD, thus enriching the scientific connotation of TCM theories and facilitating the exploration of TCM in the treatment of NAFLD.

Qinlian Hongqu Decoction Modulates FXR/TGR5/GLP-1 Pathway to Improve Insulin Resistance in NAFLD Mice: Bioinformatics and Experimental Study

Background: Qinglian Hongqu decoction (QLHQD), a traditional Chinese herbal remedy, shows potential in alleviating metabolic issues related to nonalcoholic fatty liver disease (NAFLD). However, its precise mode of action remains uncertain. Objective: This study aims to evaluate the efficacy and mechanisms of QLHQD in treating NAFLD. Methods: This study utilized a NAFLD mouse model to assess the effects of QLHQD on lipid metabolism, including blood lipids and hepatic steatosis, as well as glucose metabolism, including blood glucose levels, OGTT results, and serum insulin. Network pharmacology, bioinformatics, and molecular docking were used to explore how QLHQD may improve NAFLD treatment. Key proteins involved in these mechanisms were validated via WB and immunohistochemistry. Additionally, the expression of downstream pathway targets was examined to further validate the insulin resistance mechanism by which QLHQD improves NAFLD. Results: Animal studies demonstrated that QLHQD alleviated lipid abnormalities, hepatic steatosis, blood glucose levels, the insulin resistance index, and the OGTT results in NAFLD mice (P < 0.05 or 0.01). Network pharmacology and bioinformatics analyses indicated that the effects of QLHQD on NAFLD might involve bile acid secretion pathways. Subsequent validation through Western blotting, immunohistochemistry, and qPCR demonstrated that QLHQD may influence fat metabolism and insulin sensitivity in NAFLD mice via the FXR/TGR5/GLP-1 signaling pathway. Conclusion: QLHQD significantly alleviates glucose and lipid metabolism disorders in a high-fat diet-induced NAFLD mouse model. Its mechanism of action may involve the activation of the FXR/TGR5/GLP-1 signaling pathway in the gut, which reduces lipid accumulation and insulin resistance.

IL6 Derived from Macrophages under Intermittent Hypoxia Exacerbates NAFLD by Promoting Ferroptosis via MARCH3-Led Ubiquitylation of GPX4

Obstructive sleep apnea (OSA) is a common sleep disorder characterized by intermittent hypoxia (IH) and is associated with the occurrence and development of nonalcoholic fatty liver disease (NAFLD). However, the specific mechanism by which OSA induces NAFLD remains unclear. Therefore, effective interventions are lacking. This study aims to investigate the role and mechanism of ferroptosis in OSA-related NAFLD using clinical data analyses, cell-based molecular experiments, and animal experiments. Indicators of liver function, lipid accumulation, and ferroptosis are also examined. RNA-seq, qPCR, western blotting, gene intervention, and E3 ligase prediction using UbiBrowser and co-IP are used to explore the potential underlying mechanisms. The results show that ferroptosis increases in the liver tissues of patients with OSA. Chronic IH promotes NAFLD progression in mice and is alleviated by a ferroptosis inhibitor Fer-1. The increased secretion of IL6 by macrophages can promote the expression of MARCH3 in hepatocytes under intermittent conditions, and subsequently promote the ubiquitination and degradation of GPX4 to regulate ferroptosis and lipid accumulation in hepatocytes. Hence, targeted inhibition of MARCH3 may alleviate IH-induced ferroptosis and lipid accumulation in liver tissues and inhibit the progression of NAFLD.

Enhancing the functionality of mesenchymal stem cells: An attractive treatment strategy for metabolic dysfunction-associated steatotic liver disease?

The intrinsic heterogeneity of metabolic dysfunction-associated fatty liver disease (MASLD) and the intricate pathogenesis have impeded the advancement and clinical implementation of therapeutic interventions, underscoring the critical demand for novel treatments. A recent publication by Li et al proposes mesenchymal stem cells as promising effectors for the treatment of MASLD. This editorial is a continuum of the article published by Jiang et al which focuses on the significance of strategies to enhance the functionality of mesenchymal stem cells to improve efficacy in curing MASLD, including physical pretreatment, drug or chemical pretreatment, pretreatment with bioactive substances, and genetic engineering.