Insights into the Epidemiology, Pathogenesis, and Therapeutics of Nonalcoholic Fatty Liver Diseases

Exosomal miRNA combined with anti-inflammatory hyaluronic acid-based 3D bioprinted hepatic patch promotes metabolic reprogramming in NAFLD-mediated fibrosis

Non-alcoholic fatty liver disease (NAFLD) is a complex metabolic disorder, where the underlying molecular mechanisms are mostly not well-understood and therefore, warrants the need for therapeutic interventions targeting several metabolic pathways as a unified response. Of late, promising outcomes have been observed with mesenchymal stem cell-derived exosomes. However, reduced bioavailability due to systemic delivery and the need for repeated fresh isolation hinders their feasibility for clinical applications. In this regard, an 'off-the-shelf' 3D bioprinted hyaluronic acid-based hepatic patch to deliver encapsulated exosomes alone/or with hepatocytes (as dual-therapy) is developed as a holistic approach for ameliorating the disease condition and promoting tissue regeneration. The bioprinted hepatic patch demonstrated sustained and localized release of exosomes (∼82 % in 21 days), and healthy liver tissue-like mechanical properties while being biocompatible and biodegradable. Assessment in NAFLD rat models displayed alleviation of the altered biochemical parameters such as fat deposition, deranged liver functions, disrupted lipid, glucose, and insulin metabolism along with a reduction in localized inflammation, and associated liver fibrosis. The study suggests that a synergistic effect between the miRNA population of released exosomes, cell therapy, and the bioprinted matrix materials is crucial in targeting multiple complex metabolic pathways associated with the severity of the disease.

Differences in Fatty Acid Metabolism between MCDD and HFD Induced Metabolic Dysfunction-associated Fatty Liver Disease Model Mice

BACKGROUND

The global incidence of metabolic dysfunction-associated fatty liver disease (MAFLD) is increasing annually, which has become a major public-health concern. MAFLD is typically associated with obesity, hyperlipemia, or metabolic syndrome. Dietary induction is one of the most common methods for preparing animal models of MAFLD. However, there are phenotypic differences between methionine-choline-deficient diet (MCDD) and high fat diet (HFD) models.

METHODS

To explore the differences in hepatic fatty acid metabolism between MCDD and HFD induced MAFLD, we analyzed serum and liver tissue from the two MAFLD models.

RESULTS

We found that liver fat accumulation and liver function damage were common pathological features in both MAFLD models. Furthermore, in the MCDD model, the expression of hepatic fatty acid transport proteins increased, while the expression of hepatic fatty acid efflux proteins and mRNA decreased, along with a decrease in blood lipid levels. In the HFD model, the expression of hepatic fatty acid uptake proteins, efflux proteins and efflux mRNA increased, along with an increase in blood lipid levels.

CONCLUSION

Impaired fatty acid oxidation and increased hepatic fatty acid uptake play key roles in the pathogenesis of the two MAFLD models. The inverse changes in de novo lipogenesis and fatty acid efflux may represent an important pathological mechanism that leads to the phenotypic differences between the MCDD and HFD models.

Advances in research on metabolic dysfunction-associated steatotic liver disease

The global increase in obesity-related metabolic disorders has led to metabolic dysfunction-associated steatotic liver disease (MASLD) emerging as one of the most prevalent chronic liver disease worldwide. Despite growing concerns, the exact pathogenesis of MASLD remains unclear and no definitive treatments have been made available. Consequently, the need for comprehensive research on MASLD is more critical than ever. Gaining insight into the mechanisms of the disease can lay the groundwork for identifying new therapeutic targets and can facilitate the development of diagnostic tools that enable the early detection and intervention of MASLD. Research has discovered a multifactorial etiology for MASLD, suggesting that potential therapeutic strategies should be considered from a variety of perspectives. This review delves into the pathogenesis of MASLD, current diagnostic approaches, potential therapeutic targets, the status of clinical trials for emerging drugs, and the most promising treatment methods available today. With a focus on therapeutic targets, the aim is to offer fresh insights and guide for future research in the treatment of MASLD.

Bivariate tracking of NIR phototherapeutic probe that illuminates the deterioration process of NAFLD-HCC

Non-alcoholic fatty liver disease (NAFLD) has evolved to become a major cause of hepatocellular carcinoma (HCC). Visualization of NAFLD-HCC deterioration process imaging is essential to understand the underlying pathophysiological processes. However, currently relevant probes with short emission wavelengths, univariate and the inability to achieve theranostics functionality have encountered obstacles in further evaluating the NAFLD-HCC process. Here, we present a carboxylesterase (CE)-activated NIR fluorescent probe (BODJ) which has lipid droplets (LDs)-targeting ability and emits at a wavelength of 858 nm with a fluorescence quantum yield of 19.06%. CE-activated BODJ was used as a visual tool to successfully visualize both NAFLD deterioration processes and HCC in situ based on changes in the average number of LDs and the associated fluorescence intensity fluctuations. Imaging results showed that changes associated with CE and LDs in the modelled cells varied during the transition from nonalcoholic fatty liver to nonalcoholic steatohepatitis and later progression to HCC, highlighting the close association between bivariate and disease. We also demonstrate that BODJ has photodynamic (PDT) and photothermal therapy (PTT) capabilities, allowing image-guided dual phototherapy to damage HCC in situ. This NIR probe, which takes advantage of bivariate to track the deterioration process that illuminates NAFLD-HCC and has dual phototherapy capabilities, provides new ideas for the design of probes related to the diagnosis and treatment of hepatic metabolic diseases.

Hepatocyte HIF-2α aggravates NAFLD by inducing ferroptosis through increasing extracellular iron

Recent research has illuminated the pivotal role of the hypoxia-inducible factor-2α (HIF-2α)/peroxisome proliferator-activated receptor alpha (PPARα) pathway in the progression of nonalcoholic fatty liver disease (NAFLD). Meanwhile, it has been reported that HIF-2α is involved in iron regulation, and that aberrant iron distribution leads to liver lipogenesis. Therefore, we hypothesize that HIF-2α exacerbates fatty liver by affecting iron distribution. To substantiate this hypothesis, we utilized liver-specific HIF-2α knockout mice and the LO2 cell line with overexpressed HIF-2α. HIF-2α overexpression (OE) was induced via lentiviral infection, followed by exposure to free fatty acids (FFAs) and deferoxamine (DFO). In animal experiments, hepatic HIF-2α knockout resulted in lower liver lipid levels, lower liver weight, and higher serum iron levels. Enrichment in autophagy, ferroptosis, and the PI3K-AKT pathway was demonstrated through Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis in the liver of mice. In vitro experiments showed that HIF-2α increased supernatant iron. In the HIF-2α OE group, the addition of FFA led to decreased levels of reduced glutathione (GSH) and glutathione peroxidase 4 (GPX4) protein, along with increased lipid peroxidation (LPO), cellular lipid droplets, and triglyceride content. Impressively, DFO intervention decreased supernatant iron, reversed these changes by increasing GSH and GPX4 levels, and simultaneously reduced LPO levels, cellular lipid droplets, and triglyceride content. In addition, the expression of proteins related to β-oxidation increased, and lipid deposition in hepatocytes improved, which may be associated with the PI3K/AKT pathway. In summary, our findings suggest that HIF-2α-mediated iron flux enhances NAFLD cell susceptibility to ferroptosis, thereby impacting lipid metabolism-related genes and contributing to lipid accumulation.NEW & NOTEWORTHY The experiment demonstrated that HIF-2α increased extracellular iron. In LO2 cells overexpressing HIF-2α, FFAs not only increased cellular lipid and triglyceride levels but also induced key features of ferroptosis, such as reduced GSH and GPX4 levels and increased LPO, despite the absence of cellular iron overload. These effects were reversed by lowering extracellular iron with DFO. Furthermore, DFO treatment increased β-oxidation protein expression and improved lipid deposition in hepatocytes, potentially through the PI3K/AKT pathway.

Betaine alleviates nonalcoholic fatty liver disease (NAFLD) via a manner involving BHMT/FTO/m6A/ PGC1α signaling

Nonalcoholic fatty liver disease (NAFLD) has emerged as a major public health crisis with significant health threats and economic burdens worldwide in the past decades. Betaine, a naturally occurring alkaloid compound present in various dietary sources including spinach and beets, has been shown to ameliorate hepatic lipid metabolism and attenuate (NAFLD), while the underlying mechanism remains elusive. Here, we propose a novel mechanism through which betaine exerts its protective effects against hepatic lipid accumulation and (NAFLD) from an epigenetics perspective. Specifically, we discover that betaine upregulates betaine homocysteine S-methyltransferase (BHMT) expression, leading to increased nicotinamide adenine dinucleotide phosphate (NADPH) production and subsequent upregulation of fat mass and obesity-associated protein (FTO) expression. Increased abundance of FTO targets peroxisome proliferator-activated receptor-gamma coactivator 1-alpha (PGC1α) mRNA and reduces the N6-methyladenosine (m6A) level in the CDS of Ppargc1α transcript, which positively regulates PGC1α expression and subsequently inhibits hepatic lipid accumulation. Overall, our works demonstrate that betaine may be a promising therapeutic strategy for treating (NAFLD) and improving liver function through the regulation of (NADPH) and m6A-mediated pathways.

The gut-liver axis: emerging mechanisms and therapeutic approaches for nonalcoholic fatty liver disease and type 2 diabetes mellitus

Nonalcoholic fatty liver disease (NAFLD), more appropriately known as metabolic (dysfunction) associated fatty liver disease (MAFLD), a prevalent condition in type 2 diabetes mellitus (T2DM) patients, is a complex condition involving hepatic lipid accumulation, inflammation, and liver fibrosis. The gut-liver axis is closely linked to metabolic dysfunction, insulin resistance, inflammation, and oxidative stress that are leading to the cooccurrence of MAFLD and T2DM cardiovascular diseases (CVDs). The purpose of this review is to raise awareness about the role of the gut-liver axis in the progression of MAFLD, T2DM and CVDs with a critical analysis of available treatment options for T2DM and MAFLD and their impact on cardiovascular health. This study analysed over 100 articles on this topic, using online searches and predefined keywords, to understand and summarise published research. Numerous studies have shown a strong correlation between gut dysfunction, particularly the gut microbiota and its metabolites, and the occurrence and progression of MAFLD and type 2 diabetes mellitus (T2DM). Herein, this article also examines the impact of the gut-liver axis on MAFLD, T2DM, and related complications, focusing on the role of gut microbiota dysbiosis in insulin resistance, T2DM and obesity-related cardiovascular complications. The study suggests potential treatment targets for MAFLD linked to T2DM, focusing on cardiovascular outcomes and the molecular mechanism of the gut-liver axis, as gut microbiota dysbiosis contributes to obesity-related metabolic abnormalities.

Interrelationships Among Individual Factors, Family Factors, and Quality of Life in Older Chinese Adults: Cross-Sectional Study Using Structural Equation Modeling

BACKGROUND

China's rapidly aging population necessitates effective strategies for ensuring older adults' quality of life (QOL). While individual factors (IF) and family factors (FF) are known to influence QOL, existing research often examines these factors in isolation or focuses on specific subpopulations, overlooking potential interactions and mediating pathways.

OBJECTIVE

This study aims to examine both direct and indirect pathways connecting IF and FF to older adults' QOL, focusing on the mediating roles of health risks (HR) and health care service demand (HSD).

METHODS

This study uses structural equation modeling (SEM) to analyze cross-sectional data from 8600 older participants in the 2015 China Health and Retirement Longitudinal Study (CHARLS), a nationally representative study using a multistage probability proportional to size sampling method.

RESULTS

Among the 8600 participants, the majority (5586/8502, 65.7%) were aged 60-70 years, with a near-equal distribution of males and females at around 50%. The average PCS score was 76.77, while the MCS score averaged 59.70. Both IF (β=0.165, P<.001) and FF (β=0.189, P<.001) had a direct positive effect on QOL. Furthermore, the indirect effects of IF (β=0.186, P<.001) and FF (β=0.211, P<.001) through HR and HSD were also significant. In the direct model, IF and FF had a greater impact on MCS (β=0.841) than on PCS (β=0.639). However, after including the 2 mediating factors, HR and HSD, the influence of IF and FF on MCS (β=0.739) became consistent with that on PCS (β=0.728). Subgroup analyses revealed that the direct effect of IF on QOL was significant in the 60-70 age group (β=0.151, P<.001) but not in those over 70 years old (β=0.122, P=.074). Comorbidity status significantly influenced the pathway from HR to HSD, with older adults having 2 or more chronic diseases (β=0.363) showing a greater impact compared to those with fewer than 2 chronic diseases (β=0.358).

CONCLUSIONS

Both IF (education, per capita disposable income, and endowment insurance) and FF (satisfaction with a spouse and children) directly impact the QOL in older people. Meanwhile, IF and FF have equal influence on QOL through the mediating role of HR and HSD. Recognizing the interplay among these factors is crucial for targeted interventions to enhance the well-being of older adults in China.

Silymarin targets the FXR protein through microbial metabolite 7-keto-deoxycholic acid to treat MASLD in obese mice

BACKGROUND

Silymarin is recognized for its excellent hepato-protective properties. Recent clinical studies have examined the effects of silymarin on metabolic dysfunction-associated steatotic liver disease (MASLD), highlighting the necessity of further exploration into optimal dosages, active components, and mechanisms of action.

METHODS AND RESULTS

This study assessed the anti-inflammatory activity of the principal constituents of silymarin at the cellular level. The therapeutic effects of varying silymarin doses and components on MASLD in mouse models induced by a high-fat diet (HFD) were also examined. These findings indicate the superior efficacy of 80 mg kg-1 silymarin in mitigating liver steatosis and reducing lipid accumulation compared to 30 mg kg-1 silymarin or a combination of silybin and isosilybin A. The mechanism of silymarin involves regulating gut microbiota homeostasis and influencing the TLR4/NF-κB signalling pathway through LPS. Bile acid-targeted metabolomics analysis revealed that silymarin significantly decreases the HFD-induced increase in 7-keto-deoxycholic acid (7-KDCA). Further investigations suggested that 7-KDCA as an antagonist targeted farnesoid X receptor (FXR) and that both silybin and isosilybin A could directly interact with FXR.

CONCLUSION

These findings elucidate that 80 mg kg-1 of silymarin can exert therapeutic effects on MASLD mice and offer novel insights into the mechanism of silymarin in treating MASLD. Especially, it was found that silymarin could regulate bile acid metabolism, reduce the concentration of 7-KDCA, and thus perform negative feedback regulation on FXR.

CPS1 augments hepatic glucagon response through CaMKII/FOXO1 pathway

Introduction: Elevated glucagon levels are a characteristic feature of type 2 diabetes. This abnormal increase in glucagon can lead to an accelerated rate of gluconeogenesis. Glucagon also stimulates hepatic metabolism of amino acids, particularly promoting the formation of urea. The specific role of carbamoyl phosphate synthetase 1 (CPS1), a rate-limiting enzyme in the urea cycle, in the development versus the persistence of glucagon-induced hyperglycemia has not been previously established. Methods: The study employed both in vivo and in vitro approaches to assess the impact of CPS1 modulation on glucagon response. CPS1 was knockdown or overexpression to evaluate its influence on hepatic gluconeogenesis. In addition, an in-silico strategy was employed to identify a potential CPS1 inhibitor. Results: Knockdown of CPS1 significantly reduced the glucagon response both in vivo and in vitro. Conversely, overexpression of CPS1 resulted in an overactive hepatic gluconeogenic response. Mechanistically, CPS1 induced the release of calcium ions from the endoplasmic reticulum, which in turn triggered the phosphorylation of CaMKII. The activation of CaMKII then facilitated the dephosphorylation and nuclear translocation of FOXO1, culminating in the enhancement of hepatic gluconeogenesis. Furthermore, cynarin, a natural CPS1 inhibitor derived from the artichoke plant, had the capacity to attenuate the hepatic glucagon response in a CPS1-dependent manner. Discussion: CPS1 played a pivotal role in mediating glucagon-induced hepatic gluconeogenesis. The discovery of cynarin as a natural inhibitor of CPS1 suggested its potential as a therapeutic agent for diabetes treatment.

Autophagy in Disease Onset and Progression

Autophagy is a biological phenomenon whereby components of cells can self-degrade using autophagosomes. During this process, cells can clear dysfunctional organelles or unwanted elements. Autophagy can recycle unnecessary biomolecules into new components or sometimes, even destroy the cells themselves. This cellular process was first observed in 1962 by Keith R. Porter et al. Since then, autophagy has been studied for over 60 years, and much has been learned on the topic. Nevertheless, the process is still not fully understood. It has been proven, for example, that autophagy can be a positive force for maintaining good health by removing older or damaged cells. By contrast, autophagy is also involved in the onset and progression of various conditions caused by pathogenic infections. These diseases generally involve several important organs in the human body, including the liver, kidney, heart, and central nervous system. The regulation of the defects of autophagy defects may potentially be used to treat some diseases. This review comprehensively discusses recent research frontiers and topics of interest regarding autophagy-related diseases.

Non-Invasive Detection of Early-Stage Fatty Liver Disease via an On-Skin Impedance Sensor and Attention-Based Deep Learning

Early-stage nonalcoholic fatty liver disease (NAFLD) is a silent condition, with most cases going undiagnosed, potentially progressing to liver cirrhosis and cancer. A non-invasive and cost-effective detection method for early-stage NAFLD detection is a public health priority but challenging. In this study, an adhesive, soft on-skin sensor with low electrode-skin contact impedance for early-stage NAFLD detection is fabricated. A method is developed to synthesize platinum nanoparticles and reduced graphene quantum dots onto the on-skin sensor to reduce electrode-skin contact impedance by increasing double-layer capacitance, thereby enhancing detection accuracy. Furthermore, an attention-based deep learning algorithm is introduced to differentiate impedance signals associated with early-stage NAFLD in high-fat-diet-fed low-density lipoprotein receptor knockout (Ldlr-/-) mice compared to healthy controls. The integration of an adhesive, soft on-skin sensor with low electrode-skin contact impedance and the attention-based deep learning algorithm significantly enhances the detection accuracy for early-stage NAFLD, achieving a rate above 97.5% with an area under the receiver operating characteristic curve (AUC) of 1.0. The findings present a non-invasive approach for early-stage NAFLD detection and display a strategy for improved early detection through on-skin electronics and deep learning.

Acetylated pelargonidin-3-O-glucoside alleviates hepatocyte lipid deposition through activating the AMPK-mediated lysosome-autophagy pathway and redox state

Nonalcoholic fatty liver disease (NAFLD) is a worldwide public health issue, but a widely accepted therapy is still lacking until now. Anthocyanins are natural flavonoid compounds that possess various bioactivities, but their applications are limited due to their low bioavailability and stability. Acylated anthocyanins are reported to show higher stability, whereas their effects on NAFLD are still unclear. Herein, pelargonidin-3-O-(6''-acetyl)-glucoside (Ace Pg3G) was found to dose-dependently reduce intracellular lipid droplets and triglycerides, and improve cellular oxidative stress that accompanied lipid deposition. Besides, Ace Pg3G was proved to activate AMPK phosphorylation, thus stimulating AMPK-mediated lysosome-autophagy pathway to eliminate overloaded lipid. Further study unveiled that Ace Pg3G regulated genes related to lipid metabolism downstream of AMPK to inhibit lipid synthesis and accelerate lipid oxidation. Overall, this study provided the first evidence, to our best knowledge, that Ace Pg3G ameliorated free fatty acid-induced lipid deposition in hepatocytes through regulating AMPK-mediated autophagy pathways and redox state.

Molecular Mechanisms of Fucoxanthin in Alleviating Lipid Deposition in Metabolic Associated Fatty Liver Disease

Metabolic-associated fatty liver disease (MAFLD) is witnessing a global surge; however, it still lacks effective pharmacological interventions. Fucoxanthin, a natural bioactive metabolite derived from marine brown algae, exhibits promising pharmacological functions, particularly in ameliorating metabolic disorders. However, the mechanisms underlying its therapeutic efficacy in addressing MAFLD remain elusive. Our present findings indicated that fucoxanthin significantly alleviated palmitic acid (PA)-induced hepatic lipid deposition in vitro and obesity-induced hepatic steatosis in ob/ob mice. Moreover, at both the protein and transcriptional levels, fucoxanthin effectively increased the expression of PPARα and CPT1 (involved in fatty acid oxidation) and suppressed FASN and SREBP1c (associated with lipogenesis) in both PA-induced HepG2 cells and hepatic tissues in ob/ob mice. This modulation was accompanied by the activation of AMPK. The capacity of fucoxanthin to improve hepatic lipid deposition was significantly attenuated when utilizing the AMPK inhibitor or siRNA-mediated AMPK silencing. Mechanistically, fucoxanthin activates AMPK, subsequently regulating the KEAP1/Nrf2/ARE signaling pathway to exert antioxidative effects and stimulating the PGC1α/NRF1 axis to enhance mitochondrial biogenesis. These collective actions contribute to fucoxanthin's amelioration of hepatic steatosis induced by metabolic perturbations. These findings offer valuable insights into the prospective utilization of fucoxanthin as a therapeutic strategy for managing MAFLD.

Unveiling global research trends and hotspots on mitochondria in NAFLD from 2000 to 2023: A bibliometric analysis

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) has garnered significant attention in the past decade as a prevalent chronic liver condition. Despite a growing body of evidence implicating mitochondria in NAFLD development, comprehensive bibliometric analyses within this research domain are scarce. This study aims to provide a thorough overview of the knowledge framework and key research areas related to mitochondria in the context of NAFLD, utilizing bibliometric techniques.

METHODS

A comprehensive search of publications on mitochondria in NAFLD from 2000 to 2023 was conducted using the Web of Science Core Collection database. VOSviewers, CiteSpace, and the R package "bibliometrix" were employed for a precise assessment of the literature.

RESULTS

Examining 2530 articles from 77 countries, primarily led by the United States and China, revealed a consistent increase in publications on mitochondria's role in NAFLD. Leading research institutions include the University of Coimbra, the University of Missouri, the Chinese Academy of Sciences, Fudan University, and Shanghai Jiao Tong University. Notably, the International Journal of Molecular Sciences emerged as the most popular journal, and Hepatology was the most frequently cited. With contributions from 14,543 authors, Michael Roden published the highest number of papers, and A. J. Samyal was the most frequently cocited author. Key focus areas include investigating mitochondrial mechanisms impacting NAFLD and developing therapeutic strategies targeting mitochondria. Emerging research hotspots are associated with keywords such as "inflammation," "mitochondrial dysfunction," "autophagy," "obesity," and "insulin resistance."

CONCLUSION

This study, the first comprehensive bibliometric analysis, synthesizes research trends and advancements in the role of mitochondria in NAFLD. Insights derived from this analysis illuminate current frontiers and emerging areas of interest, providing a valuable reference for scholars dedicated to mitochondrial studies.

DEAD-Box Helicase 17 exacerbates non-alcoholic steatohepatitis via transcriptional repression of cyp2c29, inducing hepatic lipid metabolism disorder and eliciting the activation of M1 macrophages

OBJECTIVE

Our study was to elucidate the role of RNA helicase DEAD-Box Helicase 17 (DDX17) in NAFLD and to explore its underlying mechanisms.

METHODS

We created hepatocyte-specific Ddx17-deficient mice aim to investigate the impact of Ddx17 on NAFLD induced by a high-fat diet (HFD) as well as methionine and choline-deficient l-amino acid diet (MCD) in adult male mice. RNA-seq and lipidomic analyses were conducted to depict the metabolic landscape, and CUT&Tag combined with chromatin immunoprecipitation (ChIP) and luciferase reporter assays were conducted.

RESULTS

In this work, we observed a notable increase in DDX17 expression in the livers of patients with NASH and in murine models of NASH induced by HFD or MCD. After introducing lentiviruses into hepatocyte L02 for DDX17 knockdown or overexpression, we found that lipid accumulation induced by palmitic acid/oleic acid (PAOA) in L02 cells was noticeably weakened by DDX17 knockdown but augmented by DDX17 overexpression. Furthermore, hepatocyte-specific DDX17 knockout significantly alleviated hepatic steatosis, inflammatory response and fibrosis in mice after the administration of MCD and HFD. Mechanistically, our analysis of RNA-seq and CUT&Tag results combined with ChIP and luciferase reporter assays indicated that DDX17 transcriptionally represses Cyp2c29 gene expression by cooperating with CCCTC binding factor (CTCF) and DEAD-Box Helicase 5 (DDX5). Using absolute quantitative lipidomics analysis, we identified a hepatocyte-specific DDX17 deficiency that decreased lipid accumulation and altered lipid composition in the livers of mice after MCD administration. Based on the RNA-seq analysis, our findings suggest that DDX17 could potentially have an impact on the modulation of lipid metabolism and the activation of M1 macrophages in murine NASH models.

CONCLUSION

These results imply that DDX17 is involved in NASH development by promoting lipid accumulation in hepatocytes, inducing the activation of M1 macrophages, subsequent inflammatory responses and fibrosis through the transcriptional repression of Cyp2c29 in mice. Therefore, DDX17 holds promise as a potential drug target for the treatment of NASH.

Various types of fasting diet and possible benefits in nonalcoholic fatty liver: Mechanism of actions and literature update

Non-alcoholic fatty liver disease (NAFLD) is one of the major causes of chronic liver injury, affecting around one-fourth of the general population across the world. Several important pathophysiological mechanisms underlying NAFLD include oxidative stress, inflammation, liver fibrosis, and apoptosis. Currently, therapeutic approaches are not ideal for managing NAFLD, thus new approaches and treatments are still needed. Over the last two decades, various fasting protocols have been explored to reduce body weight and improve metabolic disorders. In this review, we provide updated literature that supports fasting regimens for subjects with NAFLD and describes underlying mechanisms of action. We suggest that fasting regimens may modulate NAFLD via several mechanisms, including changes in gut microbiota, hepatic arginase, hepatic autophagy, inflammatory responses, liver functional enzymes and hepatic steatosis, fibroblast growth factors signaling, white adipose tissue browning, adipokines, circadian rhythms, lipid profiles, and body composition.

Loss of LBP triggers lipid metabolic disorder through H3K27 acetylation-mediated C/EBPβ- SCD activation in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is associated with mutations in lipopolysaccharide-binding protein ( LBP), but the underlying epigenetic mechanisms remain understudied. Herein, LBP -/- rats with NAFLD were established and used to conduct integrative targeting-active enhancer histone H3 lysine 27 acetylation (H3K27ac) chromatin immunoprecipitation coupled with high-throughput and transcriptomic sequencing analysis to explore the potential epigenetic pathomechanisms of active enhancers of NAFLD exacerbation upon LBP deficiency. Notably, LBP -/- reduced the inflammatory response but markedly aggravated high-fat diet (HFD)-induced NAFLD in rats, with pronounced alterations in the histone acetylome and regulatory transcriptome. In total, 1 128 differential enhancer-target genes significantly enriched in cholesterol and fatty acid metabolism were identified between wild-type (WT) and LBP -/- NAFLD rats. Based on integrative analysis, CCAAT/enhancer-binding protein β (C/EBPβ) was identified as a pivotal transcription factor (TF) and contributor to dysregulated histone acetylome H3K27ac, and the lipid metabolism gene SCD was identified as a downstream effector exacerbating NAFLD. This study not only broadens our understanding of the essential role of LBP in the pathogenesis of NAFLD from an epigenetics perspective but also identifies key TF C/EBPβ and functional gene SCD as potential regulators and therapeutic targets.

Cultivated Enterococcus faecium B6 from children with obesity promotes nonalcoholic fatty liver disease by the bioactive metabolite tyramine

Gut microbiota plays an essential role in nonalcoholic fatty liver disease (NAFLD). However, the contribution of individual bacterial strains and their metabolites to childhood NAFLD pathogenesis remains poorly understood. Herein, the critical bacteria in children with obesity accompanied by NAFLD were identified by microbiome analysis. Bacteria abundant in the NAFLD group were systematically assessed for their lipogenic effects. The underlying mechanisms and microbial-derived metabolites in NAFLD pathogenesis were investigated using multi-omics and LC-MS/MS analysis. The roles of the crucial metabolite in NAFLD were validated in vitro and in vivo as well as in an additional cohort. The results showed that Enterococcus spp. was enriched in children with obesity and NAFLD. The patient-derived Enterococcus faecium B6 (E. faecium B6) significantly contributed to NAFLD symptoms in mice. E. faecium B6 produced a crucial bioactive metabolite, tyramine, which probably activated PPAR-γ, leading to lipid accumulation, inflammation, and fibrosis in the liver. Moreover, these findings were successfully validated in an additional cohort. This pioneering study elucidated the important functions of cultivated E. faecium B6 and its bioactive metabolite (tyramine) in exacerbating NAFLD. These findings advance the comprehensive understanding of NAFLD pathogenesis and provide new insights for the development of microbe/metabolite-based therapeutic strategies.

Extracellular vesicles from periodontal pathogens regulate hepatic steatosis via Toll-like receptor 2 and plasminogen activator inhibitor-1

Plasminogen activator inhibitor-1 (PAI-1) is associated with nonalcoholic fatty liver disease (NAFLD) by lipid accumulation in the liver. In this study, we showed that extracellular vesicles (EVs) from the periodontal pathogens Filifactor alocis and Porphyromonas gingivalis induced steatosis by inducing PAI-1 in the liver and serum of mice fed a low-fat diet. PAI-1 induction was not observed in TLR2-/- mice. When tested using HEK-Blue hTLR2 cells, human TLR2 reporter cells, the TLR2-activating ability of serum from NAFLD patients (n = 100) was significantly higher than that of serum from healthy subjects (n = 100). Correlation analysis confirmed that PAI-1 levels were positively correlated with the TLR2-activating ability of serum from NAFLD patients and healthy subjects. Amphiphilic molecules in EVs were involved in PAI-1 induction. Our data demonstrate that the TLR2/PAI-1 axis is important for hepatic steatosis by EVs of periodontal pathogens.

Mechanism of Action and Related Natural Regulators of Nrf2 in Nonalcoholic Fatty Liver Disease

With the acceleration of people's pace of life, non-alcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease in the world, which greatly threatens people's health and safety. Therefore, there is still an urgent need for higher-quality research and treatment in this area. Nuclear factor Red-2-related factor 2 (Nrf2), as a key transcription factor in the regulation of oxidative stress, plays an important role in inducing the body's antioxidant response. Although there are no approved drugs targeting Nrf2 to treat NAFLD so far, it is still of great significance to target Nrf2 to alleviate NAFLD. In recent years, studies have reported that many natural products treat NAFLD by acting on Nrf2 or Nrf2 pathways. This article reviews the role of Nrf2 in the pathogenesis of NAFLD and summarizes the currently reported natural products targeting Nrf2 or Nrf2 pathway for the treatment of NAFLD, which provides new ideas for the development of new NAFLD-related drugs.

A bibliometric analysis and visualization of nonalcoholic fatty liver disease from 2012 to 2021

As a common chronic liver disease, nonalcoholic fatty liver disease (NAFLD) has attracted increasing attention in the past decade. Nevertheless, there are few bibliometric analyses that systematically study this field as a whole. This paper explores the latest research progress and future research trends of NAFLD through the method of bibliometric analysis. The articles related to NAFLD, published from 2012 to 2021 in the Web of Science Core Collections, were searched on February 21, 2022, using relevant keywords. Two different scientometrics software tools were used to conduct the knowledge maps of NAFLD research field. A total of 7975 articles on NAFLD research were included. From 2012 to 2021, the publications related to NAFLD increased by year. China ranked on the top of the list with 2043 publications, and the University of California System emerged as the premier institution in this field. PLOs One, Journal of Hepatology and Scientific Reports became the prolific journals in this research field. Co-cited reference analysis revealed the landmark literature in this research field. In terms of potential hotspots, the burst keywords analysis revealed that liver fibrosis stage, sarcopenia, and autophagy will become the focus of future NAFLD research. The annual output of the global publications in the field of NAFLD research showed a strong upward trend. Research in the field of NAFLD in China and America is more mature than in other countries. Classic literature lays the foundation for research, and multi-field studies provide the new development directions. And besides, fibrosis stage, sarcopenia and autophagy research are the hot spots and frontiers of this field.

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

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

Comparisons of Insulin Resistance- and Steatosis-Based Scores in Monitoring Metabolic Associated Fatty Liver Disease Treatment Response

BACKGROUND

Quantitative measurements of liver fat contents (LFCs) by magnetic resonance imaging derived-proton density fat fraction (MRI-PDFF) are accurate but limited by availability, convenience, and expense in the surveillance of metabolic associated fatty liver (MAFLD). Insulin resistance (IR) and steatosis-associated serum indices are useful in screening for MAFLD, but their value in monitoring MAFLD with or without chronic hepatitis B virus (CHB) infection remains unclear and we aimed to evaluate these scores in predicting changes in LFC.

METHODS

We conducted a prospective study between January 2015 and December 2021 with 620 consecutive participants with MAFLD (212 participants with CHB) who received a 24-week lifestyle intervention. The homeostasis model assessment of IR (HOMA-IR), HOMA2 index, glucose-insulin ratio, quantitative insulin sensitivity check index, fasting insulin resistance index, fatty liver index (FLI), hepatic steatosis index (HSI), liver fat score (LFS), visceral adiposity index, and triglycerides * glucose were calculated.

RESULTS

When using endpoints such as LFS improvements of ≥5% or 10% or escalations of ≥5%, LFS had the highest area under the curve (AUC) values at all endpoints for MAFLD alone (0.756, 95% CI: 0.707-0.805; 0.761, 95% CI: 0.705-0.818; 0.807, 95% CI: 0.713-0.901, all p < 0.05, respectively). With CHB, the FLI (AUC = 0.750) and HIS (AUC = 0.770) exhibited the highest AUCs between the former two outcomes, respectively, but no score could predict LFC escalation of ≥5%.

CONCLUSION

Among IR and steatosis scores, changes in LFC through lifestyle interventions can be captured with LFS possessing moderate precision but not in those with CHB.

Comparison of the diagnostic performance of twelve noninvasive scores of metabolic dysfunction-associated fatty liver disease

BACKGROUND

The absence of distinct symptoms in the majority of individuals with metabolic dysfunction-associated fatty liver disease (MAFLD) poses challenges in identifying those at high risk, so we need simple, efficient and cost-effective noninvasive scores to aid healthcare professionals in patient identification. While most noninvasive scores were developed for the diagnosis of nonalcoholic fatty liver disease (NAFLD), consequently, the objective of this study was to systematically assess the diagnostic ability of 12 noninvasive scores (METS-IR/TyG/TyG-WC/TyG-BMI/TyG-WtHR/VAI/HSI/FLI/ZJU/FSI/K-NAFLD) for MAFLD.

METHODS

The study recruited eligible participants from two sources: the National Health and Nutrition Examination Survey (NHANES) 2017-2020.3 cycle and the database of the West China Hospital Health Management Center. The performance of the model was assessed using various metrics, including area under the receiver operating characteristic curve (AUC), net reclassification index (NRI), integrated discrimination improvement (IDI), decision curve analysis (DCA), and subgroup analysis.

RESULTS

A total of 7398 participants from the NHANES cohort and 4880 patients from the Western China cohort were included. TyG-WC had the best predictive power for MAFLD risk in the NHANES cohort (AUC 0.863, 95% CI 0.855-0.871), while TyG-BMI had the best predictive ability in the Western China cohort (AUC 0.903, 95% CI 0.895-0.911), outperforming other models, and in terms of IDI, NRI, DCA, and subgroup analysis combined, TyG-WC remained superior in the NAHANES cohort and TyG-BMI in the Western China cohort.

CONCLUSIONS

TyG-BMI demonstrated satisfactory diagnostic efficacy in identifying individuals at a heightened risk of MAFLD in Western China. Conversely, TyG-WC exhibited the best diagnostic performance for MAFLD risk recognition in the United States population. These findings suggest the necessity of selecting the most suitable predictive models based on regional and ethnic variations.

Waist-to-height ratio associated cardiometabolic risk phenotype in children with overweight/obesity

BACKGROUND

Childhood overweight/obesity has been associated with an elevated risk of insulin resistance and cardiometabolic disorders. Waist-to-height ratio (WHtR) may be a simple screening tool to quickly identify children at elevated risk for cardiometabolic disorders. The primary objective of the present study was to create sex-specific tertile cut points of WHtR and assess its association with Insulin resistance and elevated liver enzyme concentrations in children, factors using cross-sectional data from the randomized, controlled Family Weight Management Study.

METHODS

Baseline data from 360 children (7-12 years, mean Body Mass Index (BMI) ≥ 85th percentile for age and sex) were used to calculate WHtR tertiles by sex, male: ≤ 0.55 (T1), > 0.55- ≤ 0.59 (T2), > 0.59 (T3); female: ≤ 0.56 (T1), > 0.56- ≤ 0.6 (T2), > 0.6 (T3). The Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) was used to categorize participants as insulin-resistant (HOMA-IR ≥ 2.6) and insulin-sensitive (HOMA-IR < 2.6). Liver enzymes aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were categorized as normal vs. elevated (AST of < 36.0 µkat/L or ≥ 36.0 µkat/L; ALT of < 30.0 µkat/L or ≥ 30.0 µkat/L; ALT > 26 µkat/L males, > 22 µkat/L females). We examined differences in baseline cardiometabolic risk factors by WHtR tertiles and sex-specific multivariable logistic regression models to predict HOMA-IR and elevation of liver enzymes.

RESULTS

Study participants had a mean WHtR of 0.59 ([SD: 0.06]). Irrespective of sex, children in WHtR T3 had higher BMIz scores, blood pressure, triglycerides, 2-h glucose, fasting 2-h insulin, and lower high-density lipoprotein cholesterol (HDL-C) concentrations than those in T2 and T1. After adjusting for covariates, the odds of elevated HOMA-IR (> 2.6) were over five-fold higher among males in T3 versus T1 [OR, 95%CI: 5.83, 2.34-14.52] and T2 [OR, 95%CI: 4.81, 1.94-11.92] and females in T3 [OR, 95%CI: 5.06, 2.10-12.20] versus T1. The odds of elevated ALT values (≥ 30) were 2.9 [95%CI: 1.01-8.41] fold higher among females in T3 compared to T1.

CONCLUSION

In public health settings, WHtR may be a practical screening tool in pediatric populations to identify children at risk of metabolic syndrome.

Neferine ameliorates nonalcoholic steatohepatitis through regulating AMPK pathway

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD), peculiarly nonalcoholic steatohepatitis (NASH), has become the main cause of liver transplantation and liver-related death. However, the US Food and Drug Administration has not approved a specific medication for treating NASH. Neferine (NEF), a natural bisbenzylisoquinoline alkaloid separated from the traditional Chinese medicine Nelumbinis plumula, has a variety of pharmacological properties, especially on metabolic diseases. Nevertheless, the anti-NASH effect and mechanisms of NEF remain unclear.

PURPOSE

This study aimed to investigate the amelioration of NEF on NASH and the potential mechanisms.

STUDY DESIGN

HepG2 cells, hepatic stellate cells (HSCs) and high-fat diet (HFD)+carbon tetrachloride (CCl₄) induced C57BL/6 mice were used to observe the effect of NEF against NASH and investigate the engaged mechanism.

METHODS

HSCs and HepG2 cells stimulated by oleic acid (OA) were treated with NEF. C57BL/6 mice were fed with HFD+CCl₄ to induce NASH mouse model and treated with or without NEF (5 mg/kg or 10 mg/kg, once daily, i.p) for 4 weeks.

RESULTS

NEF significantly attenuated the accumulation of lipid droplets, intracellular triglyceride (TG) levels and hepatocytes apoptosis in OA-exposed HepG2 cells. NEF not only enhanced the AMPK and ACC phosphorylation in OA-stimulated HepG2 cells, but also reduced inflammatory response and fibrosis in lipopolysaccharide (LPS)-stimulated HepG2 and in LX-2, respectively. In HFD+CCl₄-induced NASH mice, pathological staining confirmed NEF treatment mitigated hepatic lipid deposition, inflammatory cell infiltration as well as hepatic fibrosis. Furthermore, the liver weight, serum and hepatic TG and total cholesterol (TC) and aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were decreased compared with the model group. HFD+CCl₄ also induced the upregulation of specific proteins and genes associated to inflammation (ILs, TNF-α, NLRP3, ASC, CCL2 and CXCL10) and hepatic fibrosis (collagens, α-SMA, TGF-β and TIPM1), which were also suppressed by NEF treatment.

CONCLUSION

Our results demonstrated that NEF played a protective role in hepatic steatosis via the regulation of AMPK pathways, which may serve as an attractive candidate for a potential novel strategy on prevention and treatment of NASH.

The Transition of Cardiovascular Disease Risks from NAFLD to MAFLD

The increased burden of nonalcoholic fatty liver disease (NAFLD) parallels the increased incidence of overweight and metabolic syndrome worldwide. Because of the close relationship between metabolic disorders and fatty liver disease, a new term, metabolic-related fatty liver disease (MAFLD), was proposed by a group of experts to more precisely describe fatty liver disease resulting from metabolic disorders. According to the definitions, MAFLD and NAFLD populations have considerable discrepancies, but overlap does exist. This new definition has a nonnegligible impact on clinical practices, including diagnoses, interventions, and the risk of comorbidities. Emerging evidence has suggested that patients with MAFLD have more metabolic comorbidities and an increased risk of all-cause mortality, particularly cardiovascular mortality than patients with NAFLD. In this review, we systemically summarized and compared the risk and underlying mechanisms of cardiovascular disease (CVD) in patients with NAFLD or MAFLD.

Inhibition of phospholipase D1 ameliorates hepatocyte steatosis and non-alcoholic fatty liver disease

Background & Aims

Phospholipase D1 (PLD1), a phosphatidylcholine-hydrolysing enzyme, is involved in cellular lipid metabolism. However, its involvement in hepatocyte lipid metabolism and consequently non-alcoholic fatty liver disease (NAFLD) has not been explicitly explored.

Methods

NAFLD was induced in hepatocyte-specific Pld1 knockout (Pld1(H)-KO) and littermate Pld1 ^flox/flox (Pld1-Flox) control mice feeding a high-fat diet (HFD) for 20 wk. Changes of the lipid composition in the liver were compared. Alpha mouse liver 12 (AML12) cells and mouse primary hepatocytes were incubated with oleic acid or sodium palmitate in vitro to explore the role of PLD1 in the development of hepatic steatosis. Hepatic PLD1 expression was evaluated in liver biopsy samples in patients with NAFLD.

Results

PLD1 expression levels were increased in the hepatocytes of patients with NAFLD and HFD-fed mice. Compared with Pld1-Flox mice, Pld1(H)-KO mice exhibited decreased plasma glucose and lipid levels as well as lipid accumulation in liver tissues after HFD feeding. Transcriptomic analysis showed that hepatocyte-specific deficiency of PLD1 decreased Cd36 expression in steatosis liver tissues, which was confirmed at the protein and gene levels. In vitro, specific inhibition of PLD1 with VU0155069 or VU0359595 decreased CD36 expression and lipid accumulation in oleic acid- or sodium palmitate-treated AML12 cells or primary hepatocytes. Inhibition of hepatocyte PLD1 significantly altered lipid composition, especially phosphatidic acid and lysophosphatidic acid levels in liver tissues with hepatic steatosis. Furthermore, phosphatidic acid, the downstream product of PLD1, increased the expression levels of CD36 in AML12 cells, which was reversed by a PPARγ antagonist.

Conclusions

Hepatocyte-specific Pld1 deficiency ameliorates lipid accumulation and NAFLD development by inhibiting the PPARγ/CD36 pathway. PLD1 may be a new target for the treatment of NAFLD.

Impact and implications

The involvement of PLD1 in hepatocyte lipid metabolism and NAFLD has not been explicitly explored. In this study, we found that the inhibition of hepatocyte PLD1 exerted potent protective effects against HFD-induced NAFLD, which were attributable to a reduction in PPARγ/CD36 pathway-mediated lipid accumulation in hepatocytes. Targeting hepatocyte PLD1 may be a new target for the treatment of NAFLD.

Lysosomal-associated protein transmembrane 5 ameliorates non-alcoholic steatohepatitis by promoting the degradation of CDC42 in mice

Non-alcoholic steatohepatitis (NASH) has received great attention due to its high incidence. Here, we show that lysosomal-associated protein transmembrane 5 (LAPTM5) is associated with NASH progression through extensive bioinformatical analysis. The protein level of LAPTM5 bears a negative correlation with NAS score. Moreover, LAPTM5 degradation is mediated through its ubiquitination modification by the E3 ubquitin ligase NEDD4L. Discovered by experiments conducted on male mice, hepatocyte-specific depletion of Laptm5 exacerbates mouse NASH symptoms. In contrast, Laptm5 overexpression in hepatocytes exerts diametrically opposite effects. Mechanistically, LAPTM5 interacts with CDC42 and promotes its degradation through a lysosome-dependent manner under the stimulation of palmitic acid, thus inhibiting activation of the mitogen-activated protein kinase signaling pathway. Finally, adenovirus-mediated hepatic Laptm5 overexpression ameliorates aforementioned symptoms in NASH models.

Oligochitosan-based nanovesicles for nonalcoholic fatty liver disease treatment via the FXR/miR-34a/SIRT1 regulatory loop

Non-alcoholic fatty liver disease (NAFLD) is currently a common chronic liver disease worldwide. By now, however, there isn't any FDA-approved specific drug for NAFLD treatment. It has been noticed that farnesoid X receptor (FXR), miR-34a and Sirtuin1 (SIRT1) is related to the occurrence and development of NAFLD. A oligochitosan-derivated nanovesicle (UBC) with esterase responsive degradability was designed to co-encapsulate FXR agonist (obeticholic acid, OCA) and miR-34a antagomir (anta-miR-34a) into the hydrophobic membrane and the center aqueous lumen of nanovesicles, respectively, by dialysis method. The action of UBC/OCA/anta-miR-34a loop on the regulation of lipid deposition via nanovesicles was evaluated on high-fat HepG2 cells and HFD-induced mice. The obtained dual drug-loaded nanovesicles UBC/OCA/anta-miR-34a could enhance the cellular uptake and intracellular release of OCA and anta-miR-34a, leading to the reduced lipid deposition in high-fat HepG2 cells. In NAFLD mice models, UBC/OCA/anta-miR-34a achieved the best curative effect on the recovery of body weight and hepatic function. Meanwhile, in vitro and vivo experiments validated that UBC/OCA/anta-miR-34a effectively activated the expression level of SIRT1 by enhancing the FXR/miR-34a/SIRT1 regulatory loop. This study provides a promising strategy for constructing oligochitosan-derivated nanovesicles to co-deliver OCA and anta-miR-34a for NAFLD treatment. STATEMENT OF SIGNIFICANCE: This study proposed a strategy to construct oligochitosan-derivated nanovesicles to co-deliver obeticholic acid and miR-34a antagomir for NAFLD treatment. Based on the FXR/miR-34a/SIRT1 action loop, this nanovesicle effectively exerted a synergetic effect of OCA and anta-miR-34a to significantly regulate lipid deposition and recover liver function in NAFLD mice.

Transcriptome Sequencing Reveals Autophagy Networks in Rat Livers during the Development of NAFLD and Identifies Autophagy Hub Genes

(1) Autophagy is an important biological process in cells and is closely associated with the development and progression of non-alcoholic fatty liver disease (NAFLD). Therefore, this study aims to investigate the biological function of the autophagy hub genes, which could be used as a potential therapeutic target and diagnostic markers for NAFLD. (2) Male C57BL/6J mice were sacrificed after 16 and 38 weeks of a high-fat diet, serum biochemical indexes were detected, and liver lobules were collected for pathological observation and transcriptome sequencing. The R software was used to identify differentially expressed autophagy genes (DEGs) from the transcriptome sequencing data of mice fed with a normal diet for 38 weeks (ND38) and a high-fat diet for 38 weeks (HFD38). Gene ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed on the DEGs, a protein-protein interaction (PPI) network of the DEGs was established using the STRING data website, and the results were visualized through Cytoscape. (3) After 16 weeks and 38 weeks of a high-fat diet, there was a significant increase in body weight, serum total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C) and triglycerides (TG) in mice, along with lipid accumulation in the liver, which was more severe at 38 weeks than at 16 weeks. The transcriptome data showed significant changes in the expression profile of autophagy genes in the livers of NAFLD mice following a long-term high-fat diet. Among the 31 differentially expressed autophagy-related genes, 13 were upregulated and 18 were downregulated. GO and KEGG pathway analysis revealed that these DEGs were primarily involved in autophagy, cholesterol transport, triglyceride metabolism, apoptosis, the FoxO signaling pathway, the p53 signaling pathway and the IL-17 signaling pathway. Four hub genes were identified by the PPI network analysis, of which Irs2, Pnpla2 and Plin2 were significantly downregulated, while Srebf2 was significantly upregulated by the 38-week high-fat diet. (4) The hub genes Irs2, Pnpla2, Srebf2 and Plin2 may serve as key therapeutic targets and early diagnostic markers in the progression of NAFLD.

Association between the dual use of electronic and conventional cigarettes and NAFLD status in Korean men

INTRODUCTION

This study investigated the association between smoking types, including dual use (usage of both combustible cigarettes and e-cigarettes), and non-alcoholic fatty liver disease (NAFLD) status in Korean men.

METHODS

Data from the 7th and 8th Korea National Health and Nutrition Examination Survey (KNHANES) 2016-2020 were used. The presence of NAFLD was defined by the respective cut-off values for the Hepatic Steatosis Index (HSI), NAFLD Ridge Score (NRS), and Korea National Health and Nutrition Examination Survey NAFLD score (KNS). Multivariate logistic regression analyses were used to determine the associations between smoking types and NAFLD as determined by HSI, NRS, and KNS.

RESULTS

After adjustment for confounders, an independent association was observed between dual use and NAFLD (HSI: AOR=1.47; 95% CI: 1.08-1.99, p=0.014; NRS: AOR=2.21; 95% CI: 1.70-2.86, p=0.000; KNS: AOR=1.35; 95% CI: 1.01-1.81, p=0.045). Cigarette only smokers also had significantly higher odds of NAFLD compared to never smokers for all of the NAFLD indices (HSI: AOR=1.22; 95% CI: 1.05-1.42, p=0.008; NRS: AOR=2.13; 95% CI: 1.87-2.42, p=0.000; KNS: AOR=1.33; 95% CI: 1.14-1.55, p=0.000). In subgroup analyses, no significant interaction effects were found for age, BMI, alcohol consumption, income, physical activity, and the diagnosis of T2DM. Moreover, cigarette only smokers and dual users differed significantly in terms of log-transformed urine cotinine and pack-years. The relationship between smoking type and pack-years was attenuated after stratification by age.

CONCLUSIONS

This study shows that the dual use of e-cigarettes and combustible cigarettes is associated with NAFLD. Age differences may explain why dual users, with a greater proportion of young people, appear to have fewer pack-years than cigarette only smokers. Further research should be conducted to investigate the adverse effects of dual use on hepatic steatosis.

Recent updates on targeting the molecular mediators of NAFLD

Nonalcoholic fatty liver disease (NAFLD) is rapidly becoming the most common disease worldwide in an era of rapid economic growth. NAFLD is a multifactorial disease, involving multiple genetic, metabolic, and environmental factors, and is closely associated with metabolic syndrome, obesity, and cardiovascular disease. NAFLD can be classified into nonalcoholic fatty liver disease (NAFL) and nonalcoholic steatohepatitis (NASH), which can both progress to cirrhosis and even hepatocellular carcinoma (HCC). Due to the enormous burden of NAFLD and its complications, no FDA-approved drugs for the treatment of NAFLD are on the market, and therapeutic targets and drug therapies are being actively investigated. In view of the various pathological mechanisms of NAFLD, numbers of preclinical studies and clinical trials have made rapid progress. This review mainly summarizes the most recently characterized mechanisms and therapeutic targets in each mechanism of NAFLD, focusing on the mechanism and application potential.

Changes in Lipidomics, Metabolomics, and the Gut Microbiota in CDAA-Induced NAFLD Mice after Polyene Phosphatidylcholine Treatment

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in most parts of the world. Although there is no first-line drug approved for the treatment of NAFLD, polyene phosphatidylcholine (PPC) is used by clinicians to treat NAFLD patients. This study aimed to evaluate the efficacy of PPC on a mice model of NAFLD, and to study the PPC's mechanism of action. The mice were fed a choline-deficient, L-amino acid-defined (CDAA) diet to induce NAFLD and were subsequently treated with PPC. The treatment effects were evaluated by the liver index, histopathological examination, and routine blood chemistry analyses. Lipidomics and metabolomics analyses of 54 samples were carried out using ultraperformance liquid chromatography (UPLC) coupled to a mass spectrometer to select for changes in metabolites associated with CDAA diet-induced NAFLD and the effects of PPC treatment. The intestinal flora of mice were extracted for gene sequencing to find differences before and after the induction of NAFLD and PPC treatment. PPC significantly improved the CDAA diet-induced NAFLD condition in mice. A total of 19 metabolites including 5 polar metabolites and 14 lipids showed marked changes. In addition, significant differences in the abundance of Lactobacillus were associated with NAFLD. We inferred that the protective therapeutic effect of PPC on the liver was related to the supplement of phosphatidylcholine, lysophosphatidylcholine, and sphingomyelin (PC, LPC, and SM, resectively) and acylcarnitine metabolism. This study developed a methodology for exploring the pathogenesis of NAFLD and can be extended to other therapeutic agents for treating NAFLD.

Effects of treatment of non-alcoholic fatty liver disease on heart failure with preserved ejection fraction

In the past few decades, non-alcoholic fatty liver disease (NAFLD) and heart failure with preserved ejection fraction (HFpEF) have become the most common chronic liver disease and the main form of heart failure (HF), respectively. NAFLD is closely associated with HFpEF by sharing common risk factors and/or by boosting systemic inflammation, releasing other secretory factors, and having an expansion of epicardial adipose tissue (EAT). Therefore, the treatments of NAFLD may also affect the development and prognosis of HFpEF. However, no specific drugs for NAFLD have been approved by the Food and Drug Administration (FDA) and some non-specific treatments for NAFLD are applied in the clinic. Currently, the treatments of NAFLD can be divided into non-pharmacological and pharmacological treatments. Non-pharmacological treatments mainly include dietary intervention, weight loss by exercise, caloric restriction, and bariatric surgery. Pharmacological treatments mainly include administering statins, thiazolidinediones, glucagon-like peptide-1 receptor agonists, sodium-glucose cotransporter 2 inhibitors, and metformin. This review will mainly focus on analyzing how these treatments may affect the development and prognosis of HFpEF.

Association Between Hypertension and New-Onset Non-Alcoholic Fatty Liver Disease in Chinese Non-Obese People: A Longitudinal Cohort Study

BACKGROUND

Quantification of the relationship between hypertension and non-alcoholic fatty liver disease (NAFLD) risk is limited and controversial. This study aimed to investigate the relationship between hypertension and NAFLD in non-obese Chinese and to use different methods to demonstrate that hypertension is an independent risk factor for NAFLD.

METHODS

On 16,153 nonobese individuals, a retrospective cohort study was conducted in China to examine the impact of hypertension on incident NAFLD. We compared five methods: multivariable Cox proportional-hazards regression, propensity score-matched (PSM) analysis, propensity score adjustment method (considering the propensity score as a covariate in a multivariable Cox proportional-hazard regression), and two propensity score-based weighted methods-The first one estimated the hypertension effect in the overall study population-inverse probability of treatment weights (IPTW), the other in the hypertensive population-standardized mortality ratio (SMR) weights. We also used a genetic matching (GenMatch) algorithm to match the participants for sensitive analysis.

RESULTS

Between 2010 and 2014, 16,153 participants met our inclusion criteria, including 2427 (15.03%) with hypertension. A total of 2321 (14.37%) participants developed NAFLD during the median follow-up of 2.98 years. The crude hazard ratio (HR) between hypertension and incident NAFLD was 2.05 (95% confidence interval (CI): 1.87, 2.25). The adjusted HR depended on the different methods, ranging from 1.09 (95% CI: 0.77, 1.23) for the PSM method to 2.24 (95% CI: 2.05, 2.44) for the SMR weighted analysis. Hypertensive participants with high propensity scores had a higher risk of developing NAFLD in the future. Excluding participants with propensity scores <8% yielded comparable hazard ratios with a narrower range, from 1.04 to 1.80. After adjusting for the confounding variables, the relationship also existed in the GenMatch cohort as a sensitivity analysis (HR=1.06, 95% CI 1.01-1.13).

CONCLUSION

Hypertension is a significant cause of NAFLD in Chinese adults in non-obese Chinese adults, with the hazard ratio ranging from 1.09 to 2.24.

Gender differences in the ideal cutoffs of visceral fat area for predicting MAFLD in China

BACKGROUND

Since the discovery of metabolic-associated fatty liver disease (MAFLD) in 2020, no report on the connection between the visceral fat area (VFA) and MAFLD has been published in China, and the ideal cutoffs of VFA for predicting MAFLD has not been determined so far. Thus, the purpose of this research was to clarify the relationship between VFA and MAFLD and the ideal cutoffs of VFA to predict MAFLD in the Chinese population.

METHODS

Five thousand three hundred forty subjects were included in this research, with 30% randomly selected for the validation set (n = 1602) and 70% for the Training set (n = 3738). The association between VFA and MAFLD was determined by multiple logistic regression. ROC curves were used to evaluate the prediction effect of VFA on MAFLD.

RESULTS

Multiple logistic regression analysis revealed that the VFA ORs (95% CIs) were 1.25 (1.20, 1.29) for women and 1.15 (1.12, 1.17) for men. Meanwhile, the VFA quartile OR (95% CI) were 3.07 (1.64, 5.75), 7.22 (3.97, 13.14), 18.91 (10.30, 34.71) for women and 3.07 (1.64, 5.75), 7.22 (3.97, 13.14),18.91 (10.30, 34.71) for men in the Q2, Q3, and Q4 groups compared with Q1. The ROC curve showed the VFA, WC, WHR, and WHtR to predict MAFLD, the AUC value of VFA was the highest and the prediction effect was the best. The ideal cutoffs of VFA to predict MAFLD was 115.55 cm² for women and 178.35 cm² for men, and the AUC was 0.788 and 0.795, respectively. Finally, the AUC was 0.773 for women and 0.800 for men in the validation set.

CONCLUSION

VFA was an independent predictive factor for MAFLD, and the ideal cutoff of VFA to predict MAFLD was 115.55 cm² in women and 178.35 cm² in men.

Salidroside in the Treatment of NAFLD/NASH

Non-alcoholic fatty liver disease (NAFLD) is the commonest reason for chronic liver diseases in the world and is commonly related to the hepatic manifestation of the metabolic syndrome. Non-alcoholic steatohepatitis (NASH) is a deteriorating form of NAFLD, which can eventually develop into fibrosis, cirrhosis, and liver cancer. The reason for NAFLD/NASH development is complicated, such as liver lipid metabolism, oxidative stress, inflammatory response, apoptosis and autophagy, liver fibrosis and gut microbiota. Apart from bariatric surgery and lifestyle changes, officially approved drug therapy for NAFLD/NASH treatment is lacking. Salidroside (SDS) is a phenolic compound extensively distributed in the tubers of Rhodiola plants, which possesses many significant biological activities. This review summarized the related targets regulated by SDS in treating NAFLD/NASH. It is indicated that SDS could improve the status of NAFLD/NASH by ameliorating abnormal lipid metabolism, inhibiting oxidative stress, regulating apoptosis and autophagy, reducing inflammatory response, alleviating fibrosis and regulating gut microbiota. In conclusion, although the multiple bioactivities of SDS have been confirmed, the clinical data are inadequate and need to become the focus of attention in the later study.

A multi-omic landscape of steatosis-to-NASH progression

Nonalcoholic steatohepatitis (NASH) has emerged as a major cause of liver failure and hepatocellular carcinoma. Investigation into the molecular mechanisms that underlie steatosis-to-NASH progression is key to understanding the development of NASH pathophysiology. Here, we present comprehensive multi-omic profiles of preclinical animal models to identify genes, non-coding RNAs, proteins, and plasma metabolites involved in this progression. In particular, by transcriptomics analysis, we identified Growth Differentiation Factor 3 (GDF3) as a candidate noninvasive biomarker in NASH. Plasma GDF3 levels are associated with hepatic pathological features in patients with NASH, and differences in these levels provide a high diagnostic accuracy of NASH diagnosis (AUROC = 0.90; 95% confidence interval: 0.85-0.95) with a good sensitivity (90.7%) and specificity (86.4%). In addition, by developing integrated proteomic-metabolomic datasets and performing a subsequent pharmacological intervention in a mouse model of NASH, we show that ferroptosis may be a potential target to treat NASH. Moreover, by using competing endogenous RNAs network analysis, we found that several miRNAs, including miR-582-5p and miR-292a-3p, and lncRNAs, including XLOC-085738 and XLOC-041531, are associated with steatosis-to-NASH progression. Collectively, our data provide a valuable resource into the molecular characterization of NASH progression, leading to the novel insight that GDF3 may be a potential noninvasive diagnostic biomarker for NASH while further showing that ferroptosis is a therapeutic target for the disease.

Mechanisms of Cynarine for treatment of non-alcoholic fatty liver disease based on the integration of network pharmacology, molecular docking and cell experiment

BACKGROUND

Nonalcoholic Fatty Liver Disease (NAFLD) is a chronic Liver Disease prevalent all over the world. It has become more and more common in Japan, China and most western developed countries. The global prevalence rate is 25.24%, and the trend is increasing year by year. Related studies have shown that Cynarine has certain liver protection, lipid lowering and immune intervention effects. So, this study to systematically predict and analyze the mechanism of Cynarine in the treatment of non-alcoholic fatty liver disease (NAFLD) based on the integration of network pharmacology, molecular docking, and cell experiment.

METHODS

We performed Heatmap and Venn diagram analyses to identify genes and targets in Cynarine treat NAFLD. The network of Cynarine-therapeutic targets and the protein-protein interaction network (PPI) was constructed. We used gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses to visualize associated functional pathways. The Sybyl tool was used to dock the Cynarine with key therapeutic targets molecularly. Finally, cell experiments were applied to validate the role of Cynarine in the treatment of NAFLD.

RESULTS

The Cynarine could act on 48 targets of NAFLD, and the role of CASP3, TP53, MMP9, ELANE, NOTCH1 were more important. The PPI network showed that immune and inflammation-related targets played a pivotal role. The KEGG analysis found that the PI3K-Akt signaling pathway, cell cycle and MAPK signaling pathway may be the main pathways for Cynarine to prevent and treat NAFLD. Molecular docking studies confirmed that Cynarine has good binding activity with therapeutic targets. Cynarine reduced the fat deposition ability of NAFLD model cells, and effectively reduced the levels of ALT and AST released by liver cells due to excessive lipid accumulation. We also found that Cynarine inhibited the expression of AKT1 and MAPK1.

CONCLUSIONS

This study revealed that Cynarine could significantly reduce the fat deposition ability of NAFLD model cells, which may be closely related to the effective regulation of AKT1 and MAPK1 expression by Cynarine.

Comprehensive Review of Cardiovascular Disease Risk in Nonalcoholic Fatty Liver Disease

Nonalcoholic Fatty Liver Disease (NAFLD) is a growing global phenomenon, and its damaging effects in terms of cardiovascular disease (CVD) risk are becoming more apparent. NAFLD is estimated to affect around one quarter of the world population and is often comorbid with other metabolic disorders including diabetes mellitus, hypertension, coronary artery disease, and metabolic syndrome. In this review, we examine the current evidence describing the many ways that NAFLD itself increases CVD risk. We also discuss the emerging and complex biochemical relationship between NAFLD and its common comorbid conditions, and how they coalesce to increase CVD risk. With NAFLD's rising prevalence and deleterious effects on the cardiovascular system, a complete understanding of the disease must be undertaken, as well as effective strategies to prevent and treat its common comorbid conditions.

The new antioxidant 1-benzoyl-6-hydroxy-2,2,4-trimethyl-1,2-dihydroquinoline has a protective effect against carbon tetrachloride-induced hepatic injury in rats

Liver diseases with the central pathogenetic mechanism of oxidative stress are one of the main causes of mortality worldwide. Therefore, dihydroquinoline derivatives, which are precursors of hepatoprotectors and have antioxidant activity, are of interest. We have previously found that some compounds in this class have the ability to normalize redox homeostasis under experimental conditions. Here, we initially analyzed the hepatoprotective potential of the dihydroquinoline derivative 1-benzoyl-6-hydroxy-2,2,4-trimethyl-1,2-dihydroquinoline (BHDQ) for carbon tetrachloride (CCl ₄)-induced liver injury in rats. Results suggested that BHDQ normalized the alanine aminotransferase, aspartate aminotransferase, and gamma-glutamyl transpeptidase in serum. We also observed an improvement in liver tissue morphology related to BHDQ. Animals with CCl ₄-induced liver injuries treated with BHDQ had less oxidative stress compared to animals with CCl ₄-induced liver injury. BHDQ promoted activation changes in superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, and glutathione transferase on control values in animals with CCl ₄-induced liver injury. BHDQ also activated gene transcription in Sod1 and Gpx1 via nuclear factor erythroid 2-related factor 2 and forkhead box protein O1 factors. Therefore, the compound of concern has a hepatoprotective effect by inhibiting the development of necrotic processes in the liver tissue, through antioxidation.

Modulation of endoplasmic reticulum stress via sulforaphane-mediated AMPK upregulation against nonalcoholic fatty liver disease in rats

Nonalcoholic fatty liver disease (NAFLD) is a major health concern. Endoplasmic reticulum (ER) stress, inflammation, and metabolic dysfunctions may be targeted to prevent the progress of nonalcoholic fatty liver disease. Sulforaphane (SFN), a sulfur-containing compound that is abundant in broccoli florets, seeds, and sprouts, has been reported to have beneficial effects on attenuating metabolic diseases. In light of this, the present study was designed to elucidate the mechanisms by which SFN ameliorated ER stress, inflammation, lipid metabolism, and insulin resistance - induced by a high-fat diet and ionizing radiation (IR) in rats. In our study, the rats were randomly divided into five groups: control, HFD, HFD + SFN, HFD + IR, and HFD + IR + SFN groups. After the last administration of SFN, liver and blood samples were taken. As a result, the lipid profile, liver enzymes, glucose, insulin, IL-1β, adipokines (leptin and resistin), and PI3K/AKT protein levels, as well as the mRNA gene expression of ER stress markers (IRE-1, sXBP-1, PERK, ATF4, and CHOP), fatty acid synthase (FAS), peroxisome proliferator-activated receptor-α (PPAR-α). Interestingly, SFN treatment modulated the levels of proinflammatory cytokine including IL-1β, metabolic indices (lipid profile, glucose, insulin, and adipokines), and ER stress markers in HFD and HFD + IR groups. SFN also increases the expression of PPAR-α and AMPK genes in the livers of HFD and HFD + IR groups. Meanwhile, the gene expression of FAS and CHOP was significantly attenuated in the SFN-treated groups. Our results clearly show that SFN inhibits liver toxicity induced by HFD and IR by ameliorating the ER stress events in the liver tissue through the upregulation of AMPK and PPAR-α accompanied by downregulation of FAS and CHOP gene expression.

Role of hepatic lipid species in the progression of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) has become the most common liver disease due to the global pandemic of metabolic diseases. Dysregulation of hepatic lipid metabolism plays a central role in the initiation and progression of NAFLD. With the advancement of lipidomics, an increasing number of lipid species and underlying mechanisms associating hepatic lipid components have been revealed. Therefore, the focus of this review is to highlight the links between hepatic lipid species and their mechanisms mediating the pathogenesis of NAFLD. We first summarized the interplay between NAFLD and hepatic lipid disturbances. Next, we focused on reviewing the role of saturated fatty acids, cholesterol, oxidized phospholipids, and their respective intermediates in the pathogenesis of NAFLD. The mechanisms by which monounsaturated fatty acids and other pro-resolving mediators exert protective effects are also addressed. Finally, we further discussed the implication of different analysis approaches in lipidomics. Evolving insights into the pathophysiology of NAFLD will provide the opportunity for drug development.

Pathogenesis and Therapeutic Strategies Related to Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD), one of the most common types of chronic liver disease, is strongly correlated with obesity, insulin resistance, metabolic syndrome, and genetic components. The pathological progression of NAFLD, consisting of non-alcoholic fatty liver (NAFL), non-alcoholic steatohepatitis (NASH), and liver cirrhosis, is characterized by a broad spectrum of clinical phenotypes. Although patients with mild NAFL are considered to show no obvious clinical symptoms, patients with long-term NAFL may culminate in NASH and further liver fibrosis. Even though various drugs are able to improve NAFLD, there are no FDA-approved medications that directly treat NAFLD. In this paper, the pathogenesis of NAFLD, the potential therapeutic targets, and their underlying mechanisms of action were reviewed.

TyG index is positively associated with risk of CHD and coronary atherosclerosis severity among NAFLD patients

Background

Insulin resistance (IR), endothelial dysfunction, inflammation, glucose and lipid metabolism disorders, and thrombosis are believed involved in coronary heart disease (CHD) and non-alcoholic fatty liver disease (NAFLD). Triglyceride-glucose (TyG) index, a new IR indicator, is correlated with NAFLD occurrence and severity, but its relationship with CHD risk remains unclear. This study investigated the correlation between TyG index and CHD risk among NAFLD patients.

Methods

This cross-sectional study included 424 patients with NAFLD and chest pain in the Department of Cardiology, The Second Hospital of Shanxi Medical University, from January 2021 to December 2021. The TyG index was calculated and coronary angiography performed. All individuals were divided into NAFLD + CHD and NAFLD groups and then by TyG index level. The t-test, Mann–Whitney U-test, or one-way analysis of variance compared differences in continuous variables, while the chi-square test or Fisher’s exact test compared differences in categorical variables. Logistic regression analysis determined the independent protective or hazardous factors of NAFLD with CHD. The receiver operating characteristic curve evaluated the ability of different TyG index rule-in thresholds to predict CHD. The relationship between Gensini score and TyG index was evaluated using linear correlation and multiple linear regression.

Results

CHD was detected in 255 of 424 patients. Compared to NAFLD group, multivariate logistic regression showed that TyG index was a risk factor for CHD among NAFLD patients after adjustment for age, sex, hypertension, and diabetes mellitus with the highest odds ratio (OR, 2.519; 95% CI, 1.559–4.069; P < 0.001). TG, low-density lipoprotein cholesterol, FBG and TYG–body mass index were also risk factors for CHD among NAFLD patients. High-density lipoprotein cholesterol level was a protective factor for CHD events in patients with NAFLD. In an in-depth analysis, multivariate logistic regression analysis showed that each 1-unit increase in TyG index was associated with a 2.06-fold increased risk of CHD (OR, 2.06; 95% CI, 1.16–3.65; P = 0.013). The multifactor linear regression analysis showed each 0.1-unit increase in TyG in the NAFLD-CHD group was associated with a 2.44 increase in Gensini score (β = 2.44; 95% CI, 0.97–3.91; P = 0.002).

Conclusions

The TyG index was positively correlated with CHD risk in NAFLD patients and reflected coronary atherosclerosis severity.

Exploring and Verifying the Mechanism and Targets of Shenqi Pill in the Treatment of Nonalcoholic Steatohepatitis via Network Pharmacology and Experiments

Shenqi pill (SQP), a famous traditional Chinese medicine (TCM) herbal formula derived from Jinguiyaolue (Synopsis of Prescriptions of the Golden Chamber), has long been used to treat kidney yang deficiency syndrome. According to the TCM treatment principle that the liver and kidney are homologies, the clinical use of SQP in the treatment of nonalcoholic steatohepatitis (NASH) has achieved a good effect. However, the active targeted genes and underlying mechanism remain unclear. In this study, we aimed to explore the treatment mechanism of SQP in NASH rats, which may further contribute to the in-depth exploration of SQP in clinical applications. Network pharmacology analysis was used to screen the target genes of SQP for NASH treatment based on public databases. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, and protein–protein interaction (PPI) analysis were used to search for crucial target genes and mechanisms. UPLC–MS/MS was used to verify the active compounds of the SQP screened. The hepatic pathology and biochemical indicators of rats were used to judge the modeling results and the curative effect of SQP. Western blotting and qRT–PCR were used to verify the expression of crucial target genes at the protein and RNA levels, respectively. Network pharmacology analysis and bioinformatics analysis showed that PTGS2, JUN, MYC, and CDKN1A might be crucial target genes in the primary mechanism of SQP in treating NASH and improving the inflammatory response. The UPLC–MS/MS results confirmed that the hub active compound, quercetin, screened out through the TCMSP database, is indeed present in SQP. Hepatic injury and lipid metabolism indicators of NASH rats were significantly improved after SQP treatment. The results of WB and qRT–PCR showed that the expression of PTGS2, JUN, MYC, and CDKN1A was higher in NASH rats than in normal rats and decreased after SQP treatment. The expression of inflammatory cytokines (IL-1β, IL-6, TNF-α) was reduced after SQP treatment, which confirmed that SQP could improve hepatic inflammation in rats. These results suggested that SQP could ameliorate NASH in rats, and that quercetin may be the critical active compound that exerts the therapeutic effect.

Extrahepatic organs in the development of non-alcoholic fatty liver disease in liver transplant patients

BACKGROUND AND OBJECTIVE

Non-alcoholic fatty liver disease (NAFLD) is highly prevalent in patients who undergo liver transplantation (LT). Whereas there is huge data on NAFLD, little is known about NAFLD in LT. In this review, we aim to explore extrahepatic organs and their potential mechanisms in the development of NAFLD in LT patients and discuss current limitations in preclinical and clinical scenarios with suggestions for future study.

METHODS

The following keywords, such as NAFLD, NASH, liver transplant, therapy, pathogenesis and biomarkers, were set for literature retrieval. The articles which were published articles in English till 25th June 2020 in PubMed database were included, and there is no limit for the study design type.

KEY CONTENT AND FINDINGS

Following LT, there are significant shifts in the microbiota and farnesoid X receptor may be a potential therapeutic target for NAFLD in LT settings. The roles of probiotics and diet on NALFD remain inconclusive in LT background. Nevertheless, the adipokines and cytokines disorder and local insulin resistance of adipose tissue may contribute to NAFLD process. Bariatric surgeries are promising in controlling de novo and recurrent NAFLD with significant reduction in abdominal adipose tissue, despite the optimal timing is inconclusive in LT cases. Furthermore, circumstantial evidence indicates that miRNA-33a may function as a mediator bridging sarcopenia and NAFLD of post-LT. β-Hydroxy-β-Methyl-Butyrate treatment could improve muscle status in graft recipients and shows protective potential for NAFLD in LT settings.

CONCLUSIONS

Gut, adipose tissue and muscle are intricately intertwined in promoting NAFLD in LT cases. Further animal studies are needed to deepen our understanding of mechanisms in multi-organ crosstalk. High quality clinical trials are warrant for making guidelines and developing management strategies on NAFLD after LT.

HtrA2/Omi mitigates NAFLD in high-fat-fed mice by ameliorating mitochondrial dysfunction and restoring autophagic flux

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver metabolic syndrome which affects millions of people worldwide. Recently, improving mitochondrial function and autophagic ability have been proposed as a means to prevent NAFLD. It has been previously described that high-temperature requirement protein A2 (HtrA2/Omi) favors mitochondrial homeostasis and autophagy in hepatocytes. Thus, we explored the effects of HtrA2/Omi on regulating mitochondrial function and autophagy during NAFLD development. High-fat diet (HFD)-induced NAFLD in mice and free fatty acids (FFAs)-induced hepatocytes steatosis in vitro were established. Adeno-associated viruses (AAV) in vivo and plasmid in vitro were used to restore HtrA2/Omi expression. In this study, we reported that HtrA2/Omi expression considerably decreased in liver tissues from the HFD-induced NAFLD model and in L02 cells with FFA-treated. However, restoring HtrA2/Omi ameliorated hepatic steatosis, confirming by improved serum lipid profiles, glucose homeostasis, insulin resistance, histopathological lipid accumulation, and the gene expression related to lipid metabolism. Moreover, HtrA2/Omi also attenuated HFD-mediated mitochondrial dysfunction and autophagic blockage. TEM analysis revealed that liver mitochondrial structure and autophagosome formation were improved in hepatic HtrA2/Omi administration mice compared to HFD mice. And hepatic HtrA2/Omi overexpression enhanced mitochondrial fatty acid β-oxidation gene expression, elevated LC3II protein levels, induced LC3 puncta, and decreased SQSTM1/p62 protein levels. Furthermore, hepatic HtrA2/Omi increased respiratory exchange ratio and heat production in mice. Finally, HtrA2/Omi overexpression by plasmid significantly diminished lipid accumulation, mitochondrial dysfunction, and autophagic inhibition in FFA-treated L02 hepatocytes. Taken together, we demonstrated that HtrA2/Omi was a potential candidate for the treatment of NAFLD via improving mitochondrial functions, as well as restoring autophagic flux.