Molecular pathways of nonalcoholic fatty liver disease development and progression

BefA protein alleviates progression of non-alcoholic fatty liver disease by modulating the AMPK signaling pathway through the gut-liver axis

Non-alcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver diseases worldwide, necessitating urgent novel oral treatments. In this study, β-cell expansion factor A (BefA) was evaluated in a murine NAFLD model induced by high-fat diet (HFD). Our results revealed that BefA significantly reduced body weight (36.58 ± 1.55 g vs. 42.30 ± 1.96 g, p < 0.01), fat mass-to-body weight ratio (0.023 ± 0.019 vs. 0.300 ± 0.019, p < 0.05), liver weight (1.90 ± 0.07 g vs. 2.31 ± 0.21 g, p < 0.05), and liver function parameters (ALT, AST, ALP levels reduced, p < 0.05). Notably, BefA reversed the pathological features of NAFLD, decreasing hepatic steatosis score from 3.67 ± 0.47 to 1.67 ± 0.47 (p < 0.01). Mechanistically, BefA activated the AMPK signaling pathway, resulting in the suppression of lipogenic gene transcription (ACC, FASN, SREBP-1c) and the enhancement of fatty acid oxidation (CPT-1, PPAR-α). However, AMPK inhibitor and broad-spectrum antibiotics significantly attenuated the benefits observed with BefA treatment, increasing body weight, fat-to-body weight ratio, and liver weight (p < 0.05). Similar detrimental effects were also observed in liver function indices and histopathological characteristics. These findings underscore the pivotal role of both gut microbiota modulation and AMPK signaling in BefA's therapeutic efficacy, making it a promising multitargeted approach for NAFLD treatment.

Omentin-1 mitigates non-alcoholic fatty liver disease by preserving autophagy through AMPKα/mTOR signaling pathway

Adipose tissue-derived adipokines facilitate inter-organ communication between adipose tissue and other organs. Omentin-1, an adipokine, has been implicated in the regulation of glucose and insulin metabolism. However, limited knowledge exists regarding the regulatory impact of endogenous omentin-1 on hepatic steatosis. C57BL/6J mice were fed with high-fat diet (HFD) for 8 weeks to induce nonalcoholic fatty liver disease (NAFLD), while HepG2 cells were exposed to a 0.1 mM free fatty acid (FFA) mixture for 24 h to induce hepatic steatosis. Both the mice and cells were treated with omentin-1, and the therapeutic effects as well as the underlying molecular mechanisms were investigated. Our data demonstrate that omentin-1 attenuates weight and fat mass gain, preserves glucose homeostasis, normalizes the expression of lipogenesis-related proteins, and alleviates hepatic lipid accumulation in HFD fed mice. Furthermore, omentin-1 normalized AMPKα/mTOR signaling and preserves autophagy in these mice. In vitro, omentin-1 also preserves autophagy and attenuates lipid accumulation by normalizing AMPKα/mTOR signaling in a cell model of FFA treated HepG2 cells. However, inhibition of AMPK with Compound C or AMPKα whole-body knockout reverses the above beneficial effects of omentin-1. The present study demonstrates that omentin-1 exerts a preventive effect on non-alcoholic fatty liver disease (NAFLD) by preserving autophagy through normalizing the AMPKα/mTOR pathway, thereby suggesting its potential as a promising therapeutic agent against NAFLD.

Bioinformatics based exploration of the anti-NAFLD mechanism of Wang's empirical formula via TLR4/NF-κB/COX2 pathway

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) has developed as a leading public wellness challenge as a result of changes in dietary patterns. Unfortunately, there is still a lack of effective pharmacotherapy methods for NAFLD. Wang's empirical formula (WSF) has demonstrated considerable clinical efficacy in treating metabolic disorders for years. Nevertheless, the protective effect of WSF against NAFLD and its underlying mechanism remains poorly understood.

METHODS

The NAFLD model was established using a 17-week high-sucrose and high-fat (HSHF) diet with 32 ICR mice. In assessing the therapeutic efficacy of WSF on NAFLD, we detected changes in body weight, viscera weight, biomarkers of glycolipid metabolism in serum and liver, transaminase levels and histopathology of liver with H&E and Oil Red O staining after oral administration. The chemical components in WSF were extensively identified and gathered utilizing the HPLC-Q-TOF/MS system, database mining from HMDB, MassBank, and TCMSP databases, alongside literature searches from CNKI, Wanfang and VIP databases. The forecast of network pharmacology approach was then utilized to investigate the probable mechanisms by which WSF improves NAFLD based on the performance of prospective target identification and pathway enrichment analysis. Besides, molecular docking was also conducted for the verification of combination activities between active components of WSF and core proteins related to NAFLD. In final, validation experiments of obtained pathways were conducted through ELISA, immunohistochemistry (IHC), and western blot (WB) analysis.

RESULTS

Pharmacodynamic outcomes indicated that WSF intervention effectively mitigated obesity, fat accumulation in organs, lipid metabolism disorders, abnormal transaminase levels and liver pathology injury in NAFLD mice (P < 0.05, 0.01). A total of 72 existent ingredients of WSF were acquired by HPLC-Q-TOF/MS and database, and 254 common targets (11.6% in total targets) of NAFLD and WSF were identified. Network pharmacology revealed that WSF presses NAFLD via modulating TNF, IL6, AKT1, IL1B, PTGS2 (COX2), and other targets, and the probable pathways were primarily inflammatory signaling pathways, as confirmed by molecular docking. Molecular biology experiments further conformed that WSF could decrease levels of inflammatory factors like IL-1β, IL-6 and TNF-α (P < 0.01) and expression of TLR4, NF-κB and COX-2 (P < 0.05, 0.01) in the liver.

CONCLUSION

WSF treatment effectively protects against lipid metabolism disorders and liver inflammation injury in HSHF diet-induced NAFLD mice, and its molecular mechanism might be via suppressing the TLR4/NF-κB/COX-2 inflammatory pathway to reduce the release of inflammatory cytokines in the liver.

Vitamin D supplementation alleviates high fat diet-induced metabolic associated fatty liver disease by inhibiting ferroptosis pathway

PURPOSE

Recently, a significant negative correlation has been found between vitamin D (VD) and metabolic associated fatty liver disease (MAFLD), suggesting a potential beneficial role of VD in preventing of MAFLD, while underscoring the importance of exploring its mechanisms.

METHODS

The experiment comprised two parts: male C57BL/6J mice (6 weeks) were fed a high-fat diet (HFD) and intraperitoneally injected with vitamin D3 (VD3) (1.68 IU/g/week) for 16 weeks. Meanwhile, palmitic acid (PA)-induced HepG2 cells were treated with 1,25(OH)2D3 (10 nM). The general conditions of the mice were evaluated by measuring body weight, liver/body weight, serum biochemical parameters, and inflammation indices. Additionally, injury-associated indices and histopathology were used to assess the severity of liver injury. Furthermore, indicators of ferroptosis, including lipid peroxidation, iron aggregation, and the aberrant expression of related proteins, were determined using Prussian blue staining, ELISA assay, and Western blot.

RESULTS

Long-term VD3 administration significantly reduced body weight gain and the liver/body weight ratio of HFD-induced MAFLD mice, while also improving serum lipid metabolism dysregulation and enhancing insulin sensitivity. The changes in the expressions of liver injury indices and histological manifestations due to VD3 treatment indicated that VD3 may exerts beneficial effects on liver injury through inhibiting inflammatory cell infiltration and vacuolation. Importantly, VD3 supplementation also inhibited ferroptosis by enhancing the body's antioxidant capacity, reducing local iron aggregation, and modulating the expression levels of ferroptosis-related proteins. These findings were further confirmed in a PA-induced HepG2 steatosis cell model, highlighting the pharmacological effects of VD.

CONCLUSIONS

VD shows promise in mitigating HFD -induced liver injury by improving metabolic dysregulation and inhibiting ferroptosis, suggesting therapeutic potential in MAFLD.

Proteomic signatures of ambient air pollution and risk of non-alcoholic fatty liver disease: A prospective cohort study in the UK Biobank

Air pollution has been linked with non-alcoholic fatty liver disease (NAFLD), but the underlying mechanisms characterized by perturbations in the circulating proteome profile are largely unknown. Therefore, we included 51,357 participants from the UK Biobank with 2941 plasma proteins measured in blood samples collected between 2006 and 2010, measurements of annual fine particular matter <2.5 μm in diameter (PM2.5) and nitrogen dioxide (NO2), and follow-up data on NAFLD (743 incident cases occurred over a median follow-up of 13.6 years). Multiple linear regression was used to identify proteins associated with PM2.5 and NO2. Cox proportional hazards models were applied to assess associations of PM2.5 and NO2 and identified proteins with incident NAFLD. Mediation analyses were conducted to explore the mediation role of proteins in the associations between air pollution and incident NAFLD. After adjusting for selected covariates, PM2.5 (hazard ratio [HR] = 2.57, 95%CI:1.27, 5.21, per ln increase) and NO2 (HR = 1.43, 95%CI: 1.10, 1.84, per ln increase) were positively associated with incident NAFLD. We identified 138 proteins associated with PM2.5 (92 positively, 46 inversely, FDR <0.05) and 143 with NO2 (100 positively, 43 inversely). Of the proteins that were significantly associated with both PM2.5 and NO2, 93 (79 positively, 14 inversely) and 79 (69 positively, 10 inversely) were significantly associated with incident NAFLD. Furthermore, 84 PM2.5-associated proteins and 66 NO2-associated proteins significantly mediated the corresponding association between air pollutants and incident NAFLD, with the proportion of mediation effects ranging from 3.2 % to 27.3 % for PM2.5 and 2.6 % to 20.8 % for NO2, respectively. Of note, the majority of significant mediating proteins were enriched in pathways of cytokine-cytokine receptor interaction, viral protein interaction with cytokine and cytokine receptor. Our findings suggested that long-term exposure to PM2.5 and NO2 was associated with an increased risk of NAFLD partially by perturbating circulating proteins involved in pathways of inflammation and immunity responses.

Trehalose Ameliorates Nonalcoholic Fatty Liver Disease by Regulating IRE1α-TFEB Signaling Pathway

Nonalcoholic fatty liver disease (NAFLD), characterized by hepatic lipid deposition, is one of the most prevalent chronic metabolic disorders globally, and its pharmaceutical treatments are still limited. Excessive lipid accumulation triggers endoplasmic reticulum (ER) stress and autophagy flux dysfunction, which are important mechanisms for NAFLD. Trehalose (Tre), a natural disaccharide, has been identified to reduce hepatic steatosis and glucose intolerance. However, its underlying mechanisms for NAFLD remain unclear. In this study, a high-fat-diet (HFD)-induced mouse NAFLD model and a saturated fatty acid palmitic acid (PA)-stimulated cell model were constructed. The results indicated that Tre supplementation ameliorated hepatocyte lipid deposition in vitro, as well as hepatic steatosis and hyperlipidemia in vivo. Mechanistically, Tre alleviated both autophagy flux dysfunction and endoplasmic reticulum (ER) stress. Under the stimulation of HFD or PA, Tre remarkably increased the expression and nucleic translocation of the lysosomal master protein transcription factor EB (TFEB), while decreasing the accumulation of p62 and also decreasing the ER stress markers (inositol-requiring enzyme 1 (IRE1α), XBP-1, CHOP, and BIP). Similar results were observed in an ER stressor tunicamycin (TM)-induced in vivo and in vitro models. In addition, the transcriptomic analysis of NAFLD patients revealed significant differences in ER stress-related and autophagy-related biomarkers, including TFEB, ATG7, IRE1α, and CHOP. Molecular docking results demonstrated a strong affinity between Tre and both IRE1α and TFEB. Overall, Tre protected hepatocytes from lipotoxicity-related ER stress and autophagy dysfunction, and its regulatory effect on the IRE1α-TFEB signaling pathway may be a critical mechanism. These findings suggest that Tre, as a bioactive substance with significant medicinal potential, holds considerable promise for drug development and clinical application in treating NAFLD.

Vitamin D 1,25-Dihydroxyvitamin D3 reduces lipid accumulation in hepatocytes by inhibiting M1 macrophage polarization

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD), which is a significant liver condition associated with metabolic syndrome, is the leading cause of liver diseases globally and its prevalence is on the rise in most nations. The protective impact of vitamin D on NAFLD and its specific mechanism remains unclear.

AIM

To examine the role of vitamin D in NAFLD and how vitamin D affects the polarization of hepatic macrophages in NAFLD through the vitamin D receptor (VDR)-peroxisome proliferator activated receptor (PPAR)γ pathway.

METHODS

Wild-type C57BL/6 mice were provided with a high-fat diet to trigger NAFLD model and administered 1,25-dihydroxy-vitamin D [1,25(OH)2D3] supplementation. 1,25(OH)2D3 was given to RAW264.7 macrophages that had been treated with lipid, and a co-culture with AML12 hepatocytes was set up. Lipid accumulation, lipid metabolism enzymes, M1/M2 phenotype markers, proinflammatory cytokines and VDR-PPARγ pathway were determined.

RESULTS

Supplementation with 1,25(OH)2D3 relieved hepatic steatosis and decreased the proinflammatory M1 polarization of hepatic macrophages in NAFLD. Administration of 1,25(OH)2D3 suppressed the proinflammatory M1 polarization of macrophages induced by fatty acids, thereby directly relieving lipid accumulation and metabolism in hepatocytes. The VDR-PPARγ pathway had a notable impact on reversing lipid-induced proinflammatory M1 polarization of macrophages regulated by the administration of 1,25(OH)2D3.

CONCLUSION

Supplementation with 1,25(OH)2D3 improved hepatic steatosis and lipid metabolism in NAFLD, linked to its capacity to reverse the proinflammatory M1 polarization of hepatic macrophages, partially by regulating the VDR-PPARγ pathway. The involvement of 1,25(OH)2D3 in inhibiting fatty-acid-induced proinflammatory M1 polarization of macrophages played a direct role in relieving lipid accumulation and metabolism in hepatocytes.

Lipid nanosystems for fatty liver therapy and targeted medication delivery: a comprehensive review

Fatty liver is considered to be the most common chronic liver disease with a high global incidence, which can lead to cirrhosis and liver cancer in severe cases, and there is no specific drug for the treatment of fatty liver in the clinic. The use of lipid nanosystems has the potential to be an effective means of fatty liver treatment. The pathogenesis and intervening factors associated with the development of fatty liver are reviewed, and the advantages and the disadvantages of different lipid nanosystems for the treatment of fatty liver are comprehensively discussed, including liposomes, solid lipid nanoparticles, nanostructured lipid carriers, nanoemulsions, microemulsions, and phospholipid complexes. The composition and characterisation of these lipid nanosystems are highlighted and summarised with a view to improving the efficiency of lipid nanosystems for the treatment of fatty liver. In addition, active targeting and passive targeting strategies used for fatty liver therapy are discussed in detail.

Exploring the effect and mechanism of Hippophae rhamnoides L. triterpenoid acids on improving NAFLD based on network pharmacology and experimental validation in vivo and in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

Sea buckthorn (Hippophae rhamnoides L.) is a traditional Chinese medicinal and possesses a rich medical history in terms of treating gastric disorders, sputum and cough and liver injuries in oriental medicinal system. By reason of the complicated chemical constituents, the material basis and potential pharmacological mechanism of sea buckthorn acting on Non-alcoholic fatty liver disease (NAFLD) has not been clearly elucidated.

AIM OF THE STUDY

To explore the pharmacological efficacy and underlying mechanism of sea buckthorn triterpenoid acid enrichment (STE) in the treatment of NAFLD.

MATERIALS AND METHODS

The approaches of Network pharmacology and experiment validation in vitro and in vivo were applied in this study. Firstly, targets of triterpenoid acid compounds and NAFLD were collected from databases. The crucial targets were screened by the construction of protein-protein interaction (PPI) network. Furthermore, the potential signaling pathways and targets affected by STE was predicted by GO together with KEGG enrichment analysis. Finally, the experiment validation was carried out through high-fat feeding NAFLD mice and lipid accumulation HepG2 cell model. Lipids and liver related biochemical indicators were determined, Oil Red O and H&E staining were employed to observe fat accumulation. In addition, the expression levels of proteins of key target and signal pathway anticipated in network pharmacology were detected to elaborated its action mechanism.

RESULTS

A total of 180 intersecting potential targets for enhancing NAFLD with STE were eventually identified. 6 key targets including AKT1, TNF, IL6, INS, JUN, STAT3 and TP53 were further identified and the AMPK-SREBP1 pathway was enriched. Animal experiment result showed that STE treatment could significantly reduce the levels of TG, TC, LDL-C, ALT and AST, increase the levels of HDL-C in serum, and improve lipid accumulation of epididymal fat and liver. The results of the lipid accumulation cell model indicated that STE and key compound oleanolic acid could diminish intracellular lipid levels of TG, TC, LDL-C and number of lipid droplets. Western blot results showed that the above beneficial effects could be achieved by regulating the expression of p-AMPK/AMPK, SREBP1, FAS, ACC, SCD protein.

CONCLUSION

This study confirmed the effect of STE on improving NAFLD and the potential action mechanism was involved in the regulation of the AMPK-SREBP1 pathway.

Lactobacillus sp. for the Attenuation of Metabolic Dysfunction-Associated Steatotic Liver Disease in Mice

Probiotics are studied for their therapeutic potential in the treatment of several diseases, including metabolic dysfunction-associated steatotic liver disease (MASLD). Part of the significant progress made in understanding the pathogenesis of steatosis has come from identifying the complex interplay between the gut microbiome and liver function. Recently, probiotics have shown beneficial effects for the treatment and prevention of steatosis and MASLD in rodent models and in clinical trials. Numerous studies have demonstrated the promising potential of lactic acid bacteria, especially the genus Lactobacillus. Lactobacillus is a prominent bile acid hydrolase bacterium that is involved in the biotransformation of bile acids. This genus’ modulation of the gut microbiota also contributes to overall gut health; it controls gut microbial overgrowth, shapes the intestinal bile acid pool, and alleviates inflammation. This narrative review offers a comprehensive summary of the potential of Lactobacillus in the gut-liver axis to attenuate steatosis and MASLD. It also highlights the roles of Lactobacillus in hepatic lipid metabolism, insulin resistance, inflammation and fibrosis, and bile acid synthesis in attenuating MASLD.

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.

Effects of therapeutically approved individual bile acids on the development of metabolic dysfunction-associated steatohepatitis a low bile acid mouse model

Bile acid (BA) signaling dysregulation is an important etiology for the development of metabolic dysfunction-associated steatotic liver disease (MASLD). As diverse signaling molecules synthesized in the liver by pathways initiated with CYP7A1 and CYP27A1, BAs are endogenous modulators of farnesoid x receptor (FXR). FXR activation is crucial in maintaining BA homeostasis, regulating lipid metabolism, and suppressing inflammation. Additionally, BAs interact with membrane receptors and gut microbiota to regulate energy expenditure and intestinal health. Complex modulation of BAs in vivo and the lack of suitable animal models impede our understanding of the functions of individual BAs, especially during MASLD development. Previously, we determined that acute feeding of individual BAs differentially affects lipid, inflammation, and oxidative stress pathways in a low-BA mouse model, Cyp7a1/Cyp27a1 double knockout (DKO) mice. Currently, we investigated to what degree cholic acid (CA), deoxycholic acid (DCA), or ursodeoxycholic acid (UDCA) at physiological concentrations impact MASLD development in DKO mice. The results showed that these 3 BAs varied in the ability to activate hepatic and intestinal FXR, disrupt lipid homeostasis, and modulate inflammation and fibrosis. Additionally, UDCA activated intestinal FXR in these low-BA mice. Significant alterations in lipid uptake and metabolism in DKO mice following CA and DCA feeding indicate differences in cholesterol and lipid handling across genotypes. Overall, the DKO were less susceptible to weight gain, but more susceptible to MASH diet induced inflammation and fibrosis on CA and DCA supplements, whereas WT mice were more vulnerable to CA-induced fibrosis on the control diet.

Integrative analysis of non12-hydroxylated bile acid revealed the suppressed molecular map of alternative pathway in nonalcoholic steatohepatitis mice

Bile acids (BAs) are significantly altered in the liver and serum of patients with nonalcoholic steatohepatitis (NASH). However, the underlying mechanisms of these changes, particularly BA alternative pathways (BAP) responsible for non12-OH BAs, remain unclear. RNA-seq data were initially analyzed to reveal the changes of gene expression in NASH patients. Targeted metabolomics were conducted on plasma from NASH mice induced by high-fat or western diet with CCl4 for 10-24 weeks. Liver tissues were examined using proteomics, RT-qPCR, and western blotting. An integrated approach was then employed to analyze protein interactions and network correlations. Analysis of RNA-seq data revealed the inhibition of CYP7B1 in NASH patients, indicating the dysregulation of BAP. In NASH mouse models, dysregulation of BA circulation was observed by increased plasma total BA (TBA) levels and decreased liver TBA, with liver swelling and histopathological changes. Targeted metabolomics revealed suppressed levels of non12-OH BAs, which inversely correlated with increased liver injury markers. The reduced mRNA and protein expression of Fxr and upregulation of Lxr signaling in livers suggested the suppressed BAP was modulated by Fxr-Lxr signaling. Moreover, BAP interactions predominantly implicated multiple metabolism disruptions, involving 7 hub proteins (Hk1, Acadsb, Pklr, Insr, Ldlr, Cyp27a1, and Cyp7b1), offering promising therapeutic targets for NASH. We presented the metabolic and proteomic map of BAP and its regulatory network in NASH progression. Therapeutic targeting of BAP or its co-regulatory proteins holds promise for NASH treatment and metabolic syndrome management.

Application research and progress of microalgae as a novel protein resource in the future

Economic growth and health awareness spotlight opportunities and challenges in the food industry, particularly with decreasing arable land, climate change, dwindling freshwater resources, and pollution affecting traditional protein sources. Microalgae have emerged as a promising alternative, with higher protein content, better nutritional quality, and greater environmental resilience compared to conventional crops. They offer a protein balance comparable to meat, making them a sustainable protein source with health benefits like antioxidants, cardiovascular support, and anti-inflammatory properties. Improving the protein content of microalgae through optimized cultivation techniques is crucial to fully realize its potential as a novel food source. While there are already microalgae-based food products in the market, challenges remain in utilizing microalgal protein for widespread food production, emphasizing the need for further research. This review article explores the impact of microalgae culture conditions on protein content, the physicochemical and nutritional characteristics of microalgal protein, the health advantages of microalgal proteins and their derivatives, as well as research on separating and purifying microalgal proteins and their derivatives. It also delves into the current opportunities and obstacles of microalgal proteins and their derivatives as food, highlighting the potential for investigating the link between microalgal protein food and human health.

CT Characterization of Lipid Metabolism in Clear Cell Renal Cell Carcinoma: Relationship Between Liver Hounsfield Unit Values and Adipose Differentiation-Related Protein Gene Expression

Radiogenomics is an emerging field that links imaging features with molecular characteristics of diseases. In clear cell renal cell carcinoma (ccRCC), metabolic reprogramming leads to lipid accumulation, influenced by the adipose differentiation-related protein (ADFP). This study aimed to investigate whether hepatic and tumoral Hounsfield Unit (HU) values could serve as noninvasive radiogenomic biomarkers for ADFP expression in ccRCC. We analyzed CT images of 185 ccRCC patients, comparing lipid-associated HU values in the liver and tumor across ADFP expression statuses. Patients with low-grade ccRCC expressing ADFP showed significantly lower minimum HU values in both liver and tumor tissue, indicating greater lipid accumulation. Additionally, ADFP expression correlated negatively with abdominal adipose tissue compartments and positively with minimum tumoral HU values, linking systemic lipid metabolism to tumor biology. These findings suggest that hepatic and tumoral HU measurements may serve as noninvasive markers of lipid accumulation related to ADFP, providing insight into metabolic alterations in ccRCC. While promising, these results require validation in larger, controlled studies due to sample size and variability limitations. This approach could enhance the radiogenomic assessment of ccRCC, supporting noninvasive insights into tumor metabolism and progression.

Polysaccharide of Atractylodes macrocephala Koidz alleviates NAFLD-induced hepatic inflammation in mice by modulating the TLR4/MyD88/NF-κB pathway

Non-alcoholic fatty liver disease (NAFLD) not only could cause abnormal lipid metabolism in the liver, but also could cause liver inflammation. Previous studies have shown that Polysaccharide of Atractylodes macrocephala Koidz (PAMK) could alleviate animal liver inflammatory damage and alleviate NAFLD in mice caused by high-fat diet(HFD), but regulation of liver inflammation caused by NAFLD has rarely been reported. In this study, an animal model of non-alcoholic fatty liver inflammation in the liver of mice was established to explore the protective effect of PAMK on the liver of mice. The results showed that PAMK could alleviate the abnormal increase of body weight and liver weight of mice caused by HFD, alleviate the abnormal liver structure of mice, reduce the level of oxidative stress and cytokine secretion in the liver of mice, and downregulate the mRNA expression of TLR4, MyD88, NF-κB and protein expression of P-IκB, P-NF-κB-P65, TLR4, MyD88, NF-κB in the liver. These results indicate that PAMK could alleviate hepatocyte fatty degeneration and damage, oxidative stress and inflammatory response of the liver caused by NAFLD in mice.

Natural linoleic acid from marine fungus Eutypella sp. F0219 blocks KEAP1/NRF2 interaction and ameliorates MASLD by targeting FABP4

Ectopic lipid accumulation induced lipotoxicity plays a crucial role in exacerbating the development of metabolic dysfunction-associated steatotic liver disease (MASLD), which affects over 30 % of the worldwide population and 85 % of the obese population. The growing demand for effective therapeutic agents highlights the need for high-efficacy lipotoxicity ameliorators and relevant therapeutic targets in the fight against MASLD. This study aimed to discover natural anti-lipotoxic and anti-MASLD candidates and elucidate the underlying mechanism and therapeutic targets. Utilizing palmitic acid (PA)-induced HepG-2 and primary mouse hepatocyte models, we identified linoleic acid (HN-002), a ligand of fatty acid binding protein 4 (FABP4), from the marine fungus Eutypella sp. F0219. HN-002 dose-dependently prevented lipid overload-induced hepatocyte damage and lipid accumulation, inhibited fatty acid esterification, and ameliorated oxidative stress. These beneficial effects were associated with improvements in mitochondrial adaptive oxidation. HN-002 treatment enhanced lipid transport into mitochondria and oxidation, inhibited mitochondrial depolarization, and reduced mitochondrial ROS (mtROS) level in PA-treated hepatocytes. Mechanistically, HN-002 treatment disrupted the interaction between KEAP1 and NRF2, leading to NRF2 deubiquitylation and nuclear translocation, which activated beneficial metabolic regulation. In vivo, HN-002 treatment (20 mg/kg/per 2 days, i. p.) for 25 days effectively reversed hepatic steatosis and liver injury in the fast/refeeding plus high-fat/high-cholesterol diet induced MASLD mice. These therapeutic effects were associated with enhanced mitochondrial adaptive oxidation and activation of NRF2 signaling in the liver. These data suggest that HN-002 would be an interesting candidate for MASLD by improving mitochondrial oxidation via the FABP4/KEAP1/NRF2 axis. The discovery offers new insights into developing novel anti- MASLD agents derived from marine sources.

FXR activation remodels hepatic and intestinal transcriptional landscapes in metabolic dysfunction-associated steatohepatitis

The escalating obesity epidemic and aging population have propelled metabolic dysfunction-associated steatohepatitis (MASH) to the forefront of public health concerns. The activation of FXR shows promise to combat MASH and its detrimental consequences. However, the specific alterations within the MASH-related transcriptional network remain elusive, hindering the development of more precise and effective therapeutic strategies. Through a comprehensive analysis of liver RNA-seq data from human and mouse MASH samples, we identified central perturbations within the MASH-associated transcriptional network, including disrupted cellular metabolism and mitochondrial function, decreased tissue repair capability, and increased inflammation and fibrosis. By employing integrated transcriptome profiling of diverse FXR agonists-treated mice, FXR liver-specific knockout mice, and open-source human datasets, we determined that hepatic FXR activation effectively ameliorated MASH by reversing the dysregulated metabolic and inflammatory networks implicated in MASH pathogenesis. This mitigation encompassed resolving fibrosis and reducing immune infiltration. By understanding the core regulatory network of FXR, which is directly correlated with disease severity and treatment response, we identified approximately one-third of the patients who could potentially benefit from FXR agonist therapy. A similar analysis involving intestinal RNA-seq data from FXR agonists-treated mice and FXR intestine-specific knockout mice revealed that intestinal FXR activation attenuates intestinal inflammation, and has promise in attenuating hepatic inflammation and fibrosis. Collectively, our study uncovers the intricate pathophysiological features of MASH at a transcriptional level and highlights the complex interplay between FXR activation and both MASH progression and regression. These findings contribute to precise drug development, utilization, and efficacy evaluation, ultimately aiming to improve patient outcomes.

MAFLD-related hepatocellular carcinoma: Exploring the potent combination of immunotherapy and molecular targeted therapy

Hepatocellular carcinoma (HCC) is a common cause of cancer-related mortality and morbidity globally, and with the prevalence of metabolic-related diseases, the incidence of metabolic dysfunction-associated fatty liver disease (MAFLD) related hepatocellular carcinoma (MAFLD-HCC) continues to rise with the limited efficacy of conventional treatments, which has created a major challenge for HCC surveillance. Immune checkpoint inhibitors (ICIs) and molecularly targeted drugs offer new hope for advanced MAFLD-HCC, but the evidence for the use of both types of therapy in this type of tumour is still insufficient. Theoretically, the combination of immunotherapy, which awakens the body's anti-tumour immunity, and targeted therapies, which directly block key molecular events driving malignant progression in HCC, is expected to produce synergistic effects. In this review, we will discuss the progress of immunotherapy and molecular targeted therapy in MAFLD-HCC and look forward to the opportunities and challenges of the combination therapy.

Potential Antitumor Mechanism of Propolis Against Skin Squamous Cell Carcinoma A431 Cells Based on Untargeted Metabolomics

Propolis is a sticky substance produced by honeybees (Apis mellifera) through the collection of plant resins, which they mix with secretions from their palate and wax glands. Propolis can inhibit tumor invasion and metastasis, thereby reducing the proliferation of tumor cells and inducing cell apoptosis. Previous research has shown that propolis has an inhibitory effect on skin squamous cell carcinoma A431 cells. Nevertheless, its inhibitory mechanism is unclear because of many significantly different Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways between the ethanol extract of the propolis (EEP) group and the control group of cells. In this study, the main components of EEP and the antitumor mechanism at an IC50 of 29.04 μg/mL EEP were determined via untargeted metabolomics determined using ultra high-performance liquid chromatography tandem mass spectrometry (UHPLC‒MS/MS), respectively. The results revealed 43 polyphenolic components in the EEP and 1052 metabolites, with 160 significantly upregulated and 143 significantly downregulated metabolites between cells treated with EEP and solvent. The KEGG enrichment results revealed that EEP significantly inhibited A431 cell proliferation via the steroid hormone biosynthesis and linoleic acid metabolism pathways. These findings may provide valuable insights for the development of targeted therapies for the treatment of cutaneous squamous cell carcinoma.

The Effects of Warm Acupuncture on the Expression of AMPK in High-Fat Diet-Induced MAFLD Rats

This study investigated the effects of acupuncture and warm acupuncture on the expression and mechanism of the AMP-activated protein kinase (AMPK) signalling pathway associated with lipid accumulation in the liver tissue of rats with metabolic dysfunction-associated fatty liver disease (MAFLD) induced by a high-fat diet. Sprague-Dawley rats were categorised into four groups: control (CON), untreated MAFLD (MAFLD), and two MAFLD groups treated with acupuncture (ACU) and warm acupuncture (WA). The treatment groups underwent 16 application sessions over 8 weeks at the SP9 and BL18 acupoints. We measured the expression levels of AMPK, sterol regulatory element-binding protein1 (SREBP1), acetyl-coenzyme A carboxylase (ACC), peroxisome proliferator-activated receptorα (PPARα), carnitine palmitoyltransferase1 (CPT1), and CPT2. AMPK was activated in both ACU and WA groups. WA downregulated both SREBP1 and ACC expression at the protein level, whereas the acupuncture treatment downregulated SREBP1 expression. Additionally, WA selectively induced the activation of signalling pathways related to AMPK, PPARα, CPT1, and CPT2 at the mRNA level. Histological observations confirmed that fat accumulation was reduced in both the ACU and the WA groups compared to the MAFLD group. The WA treatment-promoted amelioration of HFD-induced MAFLD may be related to the activation of the AMPK/SREBP1/ACC pathway in the liver.

Investigation of the regulatory mechanisms of Guiqi Yimu Powder on dairy cow fatty liver cells using a multi-omics approach

Introduction

Fatty liver disease in dairy cows is a metabolic disorder that significantly affects their health and productivity, imposing a notable economic burden on the global dairy industry. Traditional Chinese medicine (TCM), characterized by its multi-component and multi-target features, has shown unique advantages in the prevention and treatment of various diseases. Guiqi Yimu Powder, a traditional TCM formula, enhances growth, boosts production efficiency, and strengthens immune function in livestock by regulating antioxidant along with anti-inflammatory pathways. However, its specific regulatory mechanisms on fatty liver in dairy cows remain unclear. This study aims to investigate the molecular-level effects and potential regulatory mechanisms of Guiqi Yimu Powder in a Trimethylamine N-oxide (TMAO) induced fatty liver cell model of dairy cows.

Methods

We employed a comprehensive analysis integrating transcriptomics, proteomics, metabolomics, and network pharmacology. An in vitro dairy cow fatty liver cell model was established using TMAO to induce lipid accumulation. Cells were treated with the optimal TMAO concentration identified through preliminary experiments, and further divided into a lipid accumulation group and Guiqi Yimu Powder treatment groups. The treatment groups received varying concentrations of Guiqi Yimu Powder (10, 20, 30, 40, or 50 g/L). High-throughput omics sequencing technologies were utilized to perform a comprehensive analysis of the treated cells. Bioinformatics methods were applied to explore the regulatory effects, aiming to elucidate the specific impacts of Guiqi Yimu Powder on lipid metabolism, liver function, and related signaling pathways, thereby providing scientific evidence for its potential application in the prevention and treatment of fatty liver in dairy cows.

Results

Guiqi Yimu Powder treatment significantly affected 1,536 genes, 152 proteins, and 259 metabolites. KEGG enrichment analysis revealed that the significantly altered molecules are involved in multiple pathways related to the pathology of fatty liver, including metabolic pathways, glutathione metabolism, hepatitis B, and AMPK signaling pathway (p < 0.05). Notably, joint analysis highlighted the regulatory mechanisms of Guiqi Yimu Powder on glutathione cycling, with L-5-Oxoproline identified as an important metabolic compound. These findings indicate its impact on oxidative stress, energy metabolism, and liver function, suggesting potential therapeutic applications for fatty liver in dairy cows.

Discussion

This study elucidated the regulatory mechanisms of Guiqi Yimu Powder on fatty liver cells in dairy cows, providing new scientific evidence for its potential application in the prevention and treatment of fatty liver disease.

A Systematic Review of the Beneficial Effects of Berry Extracts on Non-Alcoholic Fatty Liver Disease in Animal Models

CONTEXT

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in Western countries and is strongly associated with several metabolic disorders. Plant-derived bioactive extracts, such as berry extracts, with high antioxidant capacity have been used for the treatment and prevention of this pathology. Moreover, they promote circular economy and sustainability.

OBJECTIVE

To study the beneficial effects of extracts from different parts of berry plants in animal models of NAFLD.

DATA SOURCES

A systematic research of the MEDLINE (via PubMed), Cochrane, and Scopus databases was conducted to identify relevant studies published after January 2011. In vivo animal studies of NAFLD were included in which berry extracts of different parts of the plant were administered and significantly improved altered biomarkers related to the pathology, such as lipid metabolism and hepatic steatosis, glucose and glycogen metabolism, and antioxidant and anti-inflammatory biomarkers.

DATA EXTRACTION

Of a total of 203 articles identified, 31 studies were included after implementation of the inclusion and exclusion criteria.

DATA ANALYSIS

Most of the studies showed a decrease in steatosis and a stimulation of genes related to β-oxidation and downregulation of lipogenic genes, with administration of berry extracts. Berry extracts also attenuated inflammation and oxidative stress.

CONCLUSIONS

Administration of berry extracts seems to have promising potential in the design of enriched foodstuffs or nutraceuticals for the treatment of NAFLD.

Exploration of the potential mechanism of aqueous extract of Artemisia capillaris for the treatment of non-alcoholic fatty liver disease based on network pharmacology and experimental verification

OBJECTIVES

Non-alcoholic fatty liver disease (NAFLD) is a nutritional and metabolic disease with a high prevalence today. Artemisia capillaris has anti-inflammatory, antioxidant, and other effects. However, the mechanism of A. capillaris in treating NAFLD is still poorly understood.

METHODS

This study explored the mechanism of A. capillaris in the treatment of NAFLD through network pharmacology and molecular docking, and verified the results through in vivo experiments using a high-fat diet-induced mouse model and in vitro experiments using an oleic acid-induced HepG2 cell model.

KEY FINDINGS

Aqueous extract of A. capillaris (AEAC) can reduce blood lipids, reduce liver lipid accumulation and liver inflammation in NAFLD mice, and improve NAFLD. Network pharmacology analysis revealed that 51 drug ingredients in A. capillaris correspond to 370 targets that act on NAFLD. GEO data mining obtained 93 liver differentially expressed genes related to NAFLD. In the UHPLC-MS detection results, 36 components were characterized and molecular docked with JNK. Verified in vitro and in vivo, the results show that JNK and the phosphorylation levels of IL-6, IL-1β, c-Jun, c-Fos, and CCL2 are key targets and pathways.

CONCLUSIONS

This study confirmed that AEAC reduces lipid accumulation and inflammation in the liver of NAFLD mice by inhibiting the JNK/AP-1 pathway.

Hepatic-specific Pgc-1α ablation drives fibrosis in a MASH model

BACKGROUND & AIMS

Metabolic dysfunction-associated steatohepatitis (MASH) is a growing cause of chronic liver disease, characterized by fat accumulation, inflammation and fibrosis, which development depends on mitochondrial dysfunction and oxidative stress. Highly expressed in the liver during fasting, peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) regulates mitochondrial and oxidative metabolism. Given the relevant role of mitochondrial function in MASH, we investigated the relationship between PGC-1α and steatohepatitis.

METHODS

We measured the hepatic expression of Pgc-1α in both MASH patients and wild-type mice fed a western diet (WD) inducing steatosis and fibrosis. We then generated a pure C57BL6/J strain loss of function mouse model in which Pgc-1α is selectively deleted in the liver and we fed these mice with a WD supplemented with sugar water that accurately mimics human MASH.

RESULTS

We observed that the hepatic expression of Pgc-1α is strongly reduced in MASH, in both humans and mice. Moreover, the hepatic ablation of Pgc-1α promotes a considerable reduction of the hepatic mitochondrial respiratory capacity, setting up a bioenergetic harmful environment for liver diseases. Indeed, the lack of Pgc-1α decreases mitochondrial function and increases inflammation, fibrosis and oxidative stress in the scenario of MASH. Intriguingly, this profibrotic phenotype is not linked with obesity, insulin resistance and lipid disbalance.

CONCLUSIONS

In a MASH model the hepatic ablation of Pgc-1α drives fibrosis independently from lipid and glucose metabolism. These results add a novel mechanistic piece to the puzzle of the specific and crucial role of mitochondrial function in MASH development.

Metabolic consequences of interesterified palm oil and PCB-126 co-exposure in C57BL/6 mice

Metabolic dysfunction-associated steatotic liver disease (MASLD) is defined as morphofunctional changes in the liver. Studies have shown that Westernized eating patterns and environmental pollutants can directly induce the development of MASLD. This study evaluates the effect of co-exposure to interesterified palm oil (IPO) and 3,3',4,4',5-pentachlorobiphenyl (PCB-126) on the progression of MASLD in an animal model. C57BL/6 mice were fed IPO and co-exposed to PCB-126 for ten weeks. The co-exposure led to an imbalance in carbohydrate metabolism, increased systemic inflammation markers, and morphofunctional changes in the liver. These liver changes included the presence of inflammatory cells, fibrosis, alterations in aspartate transaminase (AST) and alanine transaminase (ALT) enzymes, and imbalance in gene expression related to fatty acid β-oxidation, de novo lipogenesis, mitochondrial dynamics, and endoplasmic reticulum stress. Separate exposures to IPO and PCB-126 affected metabolism and MASLD progression. Nutritional and lifestyle factors may potentiate the onset and severity of MASLD.

Emerging role of natural lipophagy modulators in metabolic dysfunction-associated steatotic liver disease

Metabolic dysfunction-associated steatotic liver disease (MASLD), previously known as non-alcoholic fatty liver disease (NAFLD), is a seriously increasing liver disorder affecting nearly 32% of adults globally. Hepatic triglycerides (TG) accumulation is the hallmark of MASLD, which results from dysregulated lipid and fatty acid uptake, increased de novo lipogenesis (DNL), and decreased lipid removal. More recently, selective autophagy of lipid droplets (LDs), termed lipophagy, has emerged to be closely associated with disrupted hepatic lipid homeostasis. Recent studies have indicated that a series of natural products have shown promise as an alternative approach in attenuating MASLD via regulating lipophagy in vivo and in vitro. Therefore, lipophagy could be a new approach for natural products to be used to improve MASLD. This article aims to provide a comprehensive overview on the interrelationship between dysregulated lipid metabolism, lipophagy, and MASLD pathogenesis. In addition, the role of some natural products as lipophagy modulators and their impact on MASLD will be discussed.

Novel eicosanoid signature in plasma provides diagnostic for metabolic dysfunction-associated steatotic liver disease

There is a clinical need for a simple test implementable at the primary point of care to identify individuals with metabolic dysfunction-associated steatotic liver disease (MASLD) in the population. Blood plasma samples from adult patients with varying phenotypes of MASLD were used to identify a minimal set of lipid analytes reflective of underlying histologically confirmed MASLD. Samples were obtained from the NIDDK Nonalcoholic Steatohepatitis Clinical Research Network (NASH CRN) NAFLD Database prospective cohort study (MASLD group; N = 301). Samples of control subjects were obtained from cohort studies at the University of California San Diego (control group; N = 48). Plasma samples were utilized for targeted quantitation of circulating eicosanoids, related bioactive metabolites, and polyunsaturated fatty acids by ultra-high performance liquid chromatography-mass spectrometry (UPLC-MS) lipidomics analysis. Bioinformatic approaches were used to discover a panel of bioactive lipids that can be used as a diagnostic tool to identify MASLD. The final panel of fifteen lipid metabolites consists of 12 eicosanoid metabolites and 3 free fatty acids that were identified to be predictive for MASLD by multivariate area under the receiver operating characteristics curve (AUROC) analysis. The panel was highly predictive for MASLD with an AUROC of 0.999 (95% CI = 0.986-1.0) with only one control misclassified. A validation study confirmed the resulting MASLD LIPIDOMICS SCORE, which may require a larger-scale prospective study to optimize. This predictive model should guide the development of a non-invasive "point-of-care" test to identify MASLD patients requiring further evaluation for the presence of metabolic dysfunction-associated steatohepatitis.

tBHQ mitigates fatty liver ischemia-reperfusion injury by activating Nrf2 to attenuate hepatocyte mitochondrial damage and macrophage STING activation

BACKGROUND

Liver ischemia-reperfusion (IR) injury is an inevitable pathophysiological process in various liver surgeries. Previous studies have found that IR injury is exacerbated in fatty liver due to significant hepatocellular damage and macrophage inflammatory activation, though the underlying mechanisms are not fully understood. In this study, we aim to explore the role and mechanism of Nrf2 (Nuclear factor erythroid 2-related factor 2) signaling in regulating hepatocellular damage and macrophage immune response in fatty liver IR injury.

METHODS

The study used high-fat diet-induced fatty liver mice to establish an IR model, alongside an in vitro co-culture system of primary hepatocytes and macrophages. This approach was used to examine mitochondrial dysfunction, oxidative stress, mitochondrial DNA (mtDNA) release, and activation of macrophage STING (Stimulator of interferon genes) signaling. We also conducted recovery verification using H-151 (a STING inhibitor) and tBHQ (an Nrf2 activator).

RESULTS

Compared to the control group, mice on a high-fat diet demonstrated more severe liver IR injury, as evidenced by increased histological damage, elevated liver enzyme levels, and heightened inflammatory markers. The HFD group showed significant oxidative stress and mitochondrial dysfunction and damage post-IR, as indicated by elevated levels of ROS and lipid peroxidation markers, and decreased antioxidant enzyme activity. Elevated mtDNA release from hepatocytes post-IR activated macrophage STING signaling, worsening inflammation and liver damage. However, STING signaling inhibition with H-151 in vivo or employing STING knockout macrophages significantly reduced these injuries. In-depth mechanism studies have found that the transfer of Nrf2 protein into the nucleus of liver cells after IR in fatty liver is reduced. Pre-treatment with tBHQ ameliorated liver oxidative stress, mitochondrial damage and suppressed the macrophage STING signaling activation.

CONCLUSIONS

Our study reveals a novel mechanism where the interaction between hepatocellular damage and macrophage inflammation intensifies liver IR injury in fatty liver. Enhancing Nrf2 activation to protect mitochondrial from oxidative stress damage and inhibiting macrophage STING signaling activation emerge as promising strategies for clinical intervention in fatty liver IR injury.

Effects of 12-weeks resistance training and vitamin E supplementation on aminotransferases, CTRP-2, and CTRP-9 levels in males with nonalcoholic fatty liver disease: a double-blind, randomized trial

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) involves excessive liver fat accumulation and is closely linked to oxidative stress, which contributes to liver inflammation and damage. This study aimed to evaluate how interventions such as resistance training (RT) and vitamin E supplementation (VES) can modulate markers of NAFLD and key proteins regulating glucose and lipid metabolism, such as C1Q/TNF-related proteins (CTRPs).

METHODS

Forty participants with NAFLD (mean age: 32.4 ± 8.2 years) were randomly assigned to one of four groups for 12 weeks: placebo (PLB), VES, PLB + RT, and VES + RT. VES was administered at 800 IU/day in a double-blind manner. The RT regimen included eight exercises at 60-80% of one-repetition maximum (1RM), with three sets of 8-12 repetitions, performed three times per week. Pre- and post-intervention assessments included body composition, aspartate aminotransferase (AST), alanine aminotransferase (ALT), lipid profile, glycemic control, CTRP-2, CTRP-9, and 1RM evaluations.

RESULTS

Following the interventions, there was a significant improvement in body composition, lipid profile, glycemic control, and 1RM indices in the exercise groups compared to non-exercise groups (p < 0.05). AST and ALT levels decreased in all groups (p < 0.05) compared to the PLB group. There was also a significant difference between the VES + RT group and both the VES and PLB + RT groups (p < 0.05). CTRP-2 and CTRP-9 levels decreased in the exercise groups compared to non-exercise groups (p < 0.05), and their changes showed a marked correlation with body composition, lipid profile, and glycemic control indices (p < 0.05).

CONCLUSIONS

This study highlights the benefits of RT on various health parameters among NAFLD patients. While adding VES to RT resulted in greater decreases in aminotransferases, it did not provide further improvements in other variables. Additionally, enhancements in body composition, lipid profile, and glycemic control indices were possibly associated with decreased levels of CTRPs.

TRIAL REGISTRATION

Registered retrospectively in the Iranian Registry of Clinical Trials (IRCT20220601055056N1) on December 21, 2023. Access at https://irct.behdasht.gov.ir/trial/69231 .

Haloacetamides disinfection by-products, a potential risk factor for nonalcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a metabolic disorder characterized by abnormal lipid deposition, with oxidative stress being a risk factor in its onset and progression. Haloacetamides (HAcAms), as unregulated disinfection by-products in drinking water, may alter the incidence and severity of NAFLD through the production of oxidative stress. We explored whether HAcAms at 1, 10, and 100-fold concentrations in Shanghai drinking water perturbed lipid metabolism in normal human liver LO-2 cells. CRISPR/Cas9 was used to construct a LO-2 line with stable NRF2 knock-down (NRF2-KD) to investigate the mechanism underlying abnormal lipid accumulation and hepatocyte damage caused by mixed exposure to HAcAms. At 100-fold real-world concentration, HAcAms caused lipid deposition and increased triglyceride accumulation in LO-2 cells, consistent with altered de novo lipogenesis. Differences in responses to HAcAms in normal and NRF2-KD LO-2 cells indicated that HAcAms caused hepatocyte lipid deposition and triglyceride accumulation by activation of the NRF2/PPARγ pathway and aggravated liver cell toxicity by inducing ferroptosis. These results indicate that HAcAms are important risk factors for NAFLD. Further observations and verifications of the effect of HAcAms on NAFLD in the population are warranted in the future.

Association between urinary polycyclic aromatic hydrocarbons and risk of metabolic associated fatty liver disease

OBJECTIVE

To investigate the effect of urinary PAHs on MAFLD.

METHODS

The study included 3,136 adults from the National Health and Nutrition Examination Survey (NHANES) conducted between 2009 and 2016. Among them, 1,056 participants were diagnosed with MAFLD and were designated as the case group. The analysis of the relationship between monohydroxy metabolites of seven PAHs in urine and MAFLD was carried out using logistic regression and Bayesian kernel regression (BKMR) models.

RESULTS

In single-pollutant models, the concentration of 2-hydroxynaphthalene (2-OHNAP) was positively correlated with MAFLD (OR = 1.47, 95% CI 1.18, 1.84), whereas 3-hydroxyfluorene (3-OHFLU) and 1-hydroxypyrene (1-OHPYR) demonstrated a negative correlation with MAFLD (OR = 0.59, 95% CI 0.48 0.73; OR = 0.70, 95% CI 0.55, 0.89). Conversely, in multi-pollutant models, 2-OHNAP, 2-hydroxyfluorene (2-OHFLU), 2-hydroxyphenanthrene, and 3-hydroxyphenanthrene (2&3-OHPHE) displayed positive correlations with MAFLD (OR = 6.17, 95% CI 3.15, 12.07; OR = 2.59, 95% CI 1.37, 4.89). However, 3-OHFLU and 1-OHPYR continued to exhibit negative correlations with MAFLD (OR = 0.09, 95% CI 0.05, 0.15; OR = 0.62, 95% CI 0.43, 0.88). Notably, the BKMR analysis mixtures approach did not indicate a significant joint effect of multiple PAHs on MAFLD, but identified interactions between 3-OHFLU and 2-OHFLU, 1-OHPYR and 2-OHFLU, and 1-OHPYR and 3-OHFLU.

CONCLUSION

No significant association was found between mixed PAHs exposure and the risk of MAFLD. However, interactions were observed between 3-OHFLU and 2-OHFLU. Both 2-OHFLU and 2&3-OHPHE exposure are significant risk factors for MAFLD, whereas 3-OHFLU is a key protective factor for the disease.

Spatial lipidomics reveals zone-specific hepatic lipid alteration and remodeling in metabolic dysfunction-associated steatohepatitis

Alteration in lipid metabolism plays a pivotal role in developing metabolic dysfunction-associated steatohepatitis (MASH). However, our understanding of alteration in lipid metabolism across liver zonation in MASH remains limited. Within this study, we investigated MASH-associated zone-specific lipid metabolism in a diet and chemical-induced MASH mouse model. Spatial lipidomics using mass spectrometry imaging in a MASH mouse model revealed 130 lipids from various classes altered across liver zonation and exhibited zone-specific lipid signatures in MASH. Triacylglycerols, diacylglycerols, sphingolipids and ceramides showed distinct zone-specific changes and re-distribution from pericentral to periportal localization in MASH. Saturated and monounsaturated fatty acids (FA) were the primary FA composition of increased lipids in MASH, while polyunsaturated FAs were the major FA composition of decreased lipids. We observed elevated fibrosis in the periportal region, which could be the result of observed metabolic alteration across zonation. Our study provides valuable insights into zone-specific hepatic lipid metabolism and demonstrates the significance of spatial lipidomics in understanding liver lipid metabolism. Identifying unique lipid distribution patterns may offer valuable insights into the pathophysiology of MASH and facilitate the discovery of diagnostic markers associated with liver zonation.

Roflumilast ameliorates GAN diet-induced non-alcoholic fatty liver disease by reducing hepatic steatosis and fibrosis in ob/ob mice

Non-alcoholic fatty liver disease (NAFLD) is a highly prevalent progressive liver disease. Currently, there is only one drug for NAFLD treatment, and the options are limited. Phosphodiesterase-4 (PDE-4) inhibitors have potential in treating NAFLD. Therefore, this study aims to investigate the effect of roflumilast on NAFLD. Here, we fed ob/ob mice to induce the NAFLD model by GAN diet. Roflumilast (1 mg/kg) was administered orally once daily. Semaglutide (20 nmol/kg), used as a positive control, was injected subcutaneously once daily. Our findings showed that roflumilast has beneficial effects on NAFLD. Roflumilast prevented body weight gain and improved lipid metabolism in ob/ob-GAN NAFLD mice. In addition, roflumilast decreased hepatic steatosis by down-regulating the expression of hepatic fatty acid synthesis genes (SREBP1c, FASN, and CD36) and improving oxidative stress. Roflumilast not only reduced liver injury by decreasing serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, but also ameliorated hepatic inflammation by reducing the gene expression of proinflammatory cytokines (TNF-α, IL-1β, and IL-6). Roflumilast lessened liver fibrosis by inhibiting the expression of fibrosis mRNA (TGFβ1, α-SMA, COL1a1, and TIMP-1). Collectively, roflumilast could ameliorate NAFLD, especially in reducing hepatic steatosis and fibrosis. Our findings suggested a PDE-4 inhibitor roflumilast could be a potential drug for NAFLD.

Far-infrared radiation alleviates steatohepatitis and fibrosis in metabolic dysfunction-associated fatty liver disease

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a disease that causes an abnormal accumulation of fat in the liver, triggering inflammation and fibrosis, the mechanism of which is not fully understood and for which there is a lack of specific drug therapy. Far-infrared radiation (FIR) has demonstrated evident therapeutic efficacy across various diseases, and novel nanomaterial graphene patches can emit it through electric heating. This study aimed to investigate the potential protective effects of FIR against MAFLD. Mice were fed with a MCD diet to mimic MAFLD progression, and histopathology analysis, biochemical analysis, RT-qPCR, and Western blotting analysis were performed to assess the effect of FIR on MAFLD in vivo. The effect of FIR treatment on MAFLD in vitro was investigated by biochemical analysis and gene expression profiling of hepatocytes. Mice subjected to the MCD diet and treated with FIR exhibited reduced hepatic lipid deposition, inflammation, fibrosis and liver damage. The therapeutic effect exerted by FIR in mice may be caused by the enhancement of AMPK phosphorylation and inhibition of the TGFβ1-SMAD2/3 pathway. Besides, FIR intervention alleviated MAFLD in hepatocytes in vitro and the results were verified by gene expression profiling. Our results revealed a promising potential of FIR as a novel therapeutic approach for MAFLD.

Hexane insoluble fraction from purple rice extract improves steatohepatitis and fibrosis via inhibition of NF-κB and JNK signaling

Nonalcoholic fatty liver disease (NAFLD) is fatty liver mainly related to metabolic syndrome. NAFLD with inflammation and hepatocellular damage is defined as nonalcoholic steatohepatitis (NASH), which can progress to cirrhosis and hepatocellular carcinoma. We have previously reported that a hexane insoluble fraction from an anthocyanin-rich purple rice ethanolic extract (PRE-HIF) can suppress prostate carcinogenesis. However, the extract's effect on NASH has not yet been established. In the present study, we investigated the chemopreventive effect of a PRE-HIF on NASH and liver fibrosis using a connexin 32 (Cx32) dominant negative transgenic (Cx32ΔTg) rat NASH model. Seven-week-old male Cx32ΔTg rats were fed a control diet, a high-fat diet (HFD), or an HFD with 1% PRE-HIF and intraperitoneal administration of dimethylnitrosamine for 17 weeks. Histological findings of NASH such as fat deposition, lobular inflammation, hepatocyte ballooning injury, and bridging fibrosis were observed in the HFD group but not in the control group, and all histological parameters were significantly improved by PRE-HIF treatment. Corresponding to the histological changes, increased expression of inflammatory cytokine mRNAs (TNF-α, IL-6, IL-18, IFN-γ, IL-1β, TGF-β1, TIMP1, TIMP2, COL1A1), along with and activation of nuclear factor-κB (NF-κB) and c-Jun N-terminal kinase (JNK) signaling were observed in the HFD group, which was significantly decreased by PRE-HIF. The number and area of hepatic precancerous glutathione S-transferase placental form-positive foci tended to be decreased by PRE-HIF. These results indicate that intake of purple rice as a dietary supplement may reduce steatohepatitis, liver injury, and fibrosis in NASH by inactivation of NF-κB or JNK.

Evaluating Bempedoic Acid for Non-alcoholic Fatty Liver Disease: A Review of Preclinical and Clinical Research

Non-alcoholic fatty liver disease (NAFLD) is the most prevalent liver disorder globally, characterized by fat accumulation in liver cells, which can progress to inflammation, fibrosis, and cirrhosis. The disease predominantly affects individuals with obesity and high body mass index (BMI). It is a globally prevalent condition, with variations in incidence across different regions. The pathophysiology of NAFLD involves insulin resistance, metabolic disturbances, and genetic and gut microbial factors. Current treatments primarily focus on lifestyle modifications and a limited range of pharmacological options. Bempedoic acid (BA), a novel cholesterol-lowering agent, targets adenosine triphosphate (ATP)-citrate lyase to reduce low-density lipoprotein (LDL) cholesterol and has shown potential in managing NAFLD by decreasing liver fat accumulation and improving lipid profiles. BA's unique mechanism offers a promising add-on therapy, particularly for the patient's intolerant to statins. Despite its potential, comprehensive clinical and preclinical studies are needed to further elucidate its efficacy and safety compared to other NAFLD treatments. Future research should focus on comparing BA with existing and emerging therapies to optimize its role in NAFLD management and enhance patient outcomes.

Mechanism of PANoptosis in metabolic dysfunction-associated steatotic liver disease

In recent years, the incidence of metabolic dysfunction-associated steatotic liver disease (MASLD) has been steadily rising, emerging as a major chronic liver disease of global concern. The course of MASLD is varied, spanning from MASLD to metabolic dysfunction associated steatohepatitis (MASH). MASH is an important contributor to cirrhosis, which may subsequently lead to hepatocellular carcinoma. It has been found that PANoptosis, an emerging inflammatory programmed cell death (PCD), is involved in the pathogenesis of MASLD and facilitates the development of NASH, eventually resulting in inflammatory fibrosis and hepatocyte death. This paper reviews the latest research progress on PANoptosis and MASLD to understand the mechanism of MASLD and provide new directions for future treatment and drug development.

Curative role of natural PPARγ agonist in non-alcoholic fatty liver disease (NAFLD)

NAFLD is a condition that develops when the liver accumulates excess fat without alcohol consumption. This chronic liver ailment progresses along with insulin resistant and is typically not diagnosed until the patients have cirrhosis. Nuclear hormone receptor superfamily PPARs are essential for metabolism of fatty acids and glucose. In liver, lipid metabolism is regulated by nuclear receptors and PPARα, and PPARβ/δ encourages fatty acid β-oxidation. PPAR-γ, an energy-balanced receptor is a crucial regulator in NAFLD. The partial activation of PPAR-γ could lead to increased level of adiponectin and insulin sensitivity, thus improved NAFLD. Because of less side effects, natural compounds are emerged as potential therapeutic agents for NAFLD by PPARγ agonists. Although the results from preclinical studies are promising, further research is needed to determine the potential dosing and efficacy of mentioned compounds in human subjects. In this review, we summarize the effect of natural PPARγ agonist in the NAFLD.

Role of Nonalcoholic Fatty Liver Disease in Periodontitis: A Bidirectional Relationship

Nonalcoholic fatty liver disease (NAFLD) and periodontitis share common risk factors such as obesity, insulin resistance (IR), and dyslipidemia, which contribute to systemic inflammation. It has been suggested that a bidirectional relationship exists between NAFLD and periodontitis, indicating that one condition may exacerbate the other. NAFLD is characterized by excessive fat deposition in the liver and is associated with low-grade chronic inflammation. There are several risk factors for the development of NAFLD, including gender, geriatric community, race, ethnicity, poor sleep quality and sleep deprivation, physical activity, nutritional status, dysbiosis gut microbiota, increased oxidative stress, overweight, obesity, higher body mass index (BMI), IR, type 2 diabetes mellitus (T2DM), metabolic syndrome (MetS), dyslipidemia (hypercholesterolemia), and sarcopenia (decreased skeletal muscle mass). This systemic inflammation can contribute to the progression of periodontitis by impairing immune responses and exacerbating the inflammatory processes in the periodontal tissues. Furthermore, individuals with NAFLD often exhibit altered lipid metabolism, which may affect oral microbiota composition, leading to dysbiosis and increased susceptibility to periodontal disease. Conversely, periodontitis has been linked to the progression of NAFLD through mechanisms involving systemic inflammation and oxidative stress. Chronic periodontal inflammation can release pro-inflammatory cytokines and bacterial toxins into the bloodstream, contributing to liver inflammation and exacerbating hepatic steatosis. Moreover, periodontitis-induced oxidative stress may promote hepatic lipid accumulation and IR, further aggravating NAFLD. The interplay between NAFLD and periodontitis underscores the importance of comprehensive management strategies targeting both conditions. Lifestyle modifications such as regular exercise, a healthy diet, and proper oral hygiene practices are crucial for preventing and managing these interconnected diseases. Additionally, interdisciplinary collaboration between hepatologists and periodontists is essential for optimizing patient care and improving outcomes in individuals with NAFLD and periodontitis.

Exploration of the Key Genes Involved in Non-alcoholic Fatty Liver Disease and Possible MicroRNA Therapeutic Targets

Background

MicroRNAs (miRNAs) are promising therapeutic agents for non-alcoholic fatty liver disease (NAFLD). This study aimed to identify key genes/proteins involved in NAFLD pathogenesis and progression and to evaluate miRNAs influencing their expression.

Methods

Gene expression profiles from datasets GSE151158, GSE163211, GSE135251, GSE167523, GSE46300, and online databases were analyzed to identify significant NAFLD-related genes. Then, protein-protein interaction networks and module analysis identified hub genes/proteins, which were validated using real-time PCR in oleic acid-treated HepG2 cells. Functional enrichment analysis evaluated signaling pathways and biological processes. Gene-miRNA interaction networks identified miRNAs targeting critical NAFLD genes.

Results

The most critical overexpressed hub genes/proteins included: TNF, VEGFA, TLR4, CYP2E1, ACE, SCD, FASN, SREBF2, and TGFB1 based on PPI network analysis, of which TNF, TLR4, SCD, FASN, SREBF2, and TGFB1 were up-regulated in oleic acid-treated HepG2 cells. Functional enrichment analysis for biological processes highlighted programmed necrotic cell death, lipid metabolic process response to reactive oxygen species, and inflammation. In the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, the highest adjusted P-value signaling pathways encompassed AGE-RAGE in diabetic complications, TNF, and HIF-1 signaling pathways. In gene-miRNA network analysis, miR-16 and miR-124 were highlighted as the miRNAs exerting the most influence on important NAFLD-related genes.

Conclusion

In silico analyses identified NAFLD therapeutic targets and miRNA candidates to guide further experimental investigation.

Exploring the Regulatory Effect of Tegillarca granosa Polysaccharide on High-Fat Diet-Induced Non-Alcoholic Fatty Liver Disease in Mice Based on Intestinal Flora

To explore the potential mechanism of action of Tegillarca granosa polysaccharide (TGP) in treating nonalcoholic fatty liver disease (NAFLD), the study conducts in vivo experiments using male C57BL/6 mice fed a high-fat diet while administering TGP for 16 weeks. The study measures body weight, liver weight, serum biochemical markers, pathological histology, liver lipid accumulation, oxidative stress and inflammation-related factors, lipid synthesis and metabolism-related gene and protein expression, and the composition and abundance of intestinal flora. Additionally, short-chain fatty acid (SCFAs) content and the correlation between intestinal flora and environmental factors are measured. The results show that TGP effectively reduces excessive hepatic lipid accumulation, dyslipidemia, abnormal liver function, and steatosis in the mice with NAFLD. Moreover, TGP effectively regulates intestinal flora disorder, increases the diversity of intestinal flora, and affects the relative abundance of specific bacteria while also increasing the content of SCFAs. These findings provide a basis for exploring the regulatory effect of T. granosa polysaccharide on NAFLD based on intestinal flora and highlight its potential as a natural liver nutraceutical.

Association between obesity phenotypes and non-alcoholic fatty liver: a large population- based study

BACKGROUND

The aim of this study was to examine the association between different metabolic obesity phenotypes and the non-alcoholic fatty liver disease (NAFLD).

METHODS

This cross-sectional analysis utilized data from the baseline phase of the Ravansar non-communicable diseases (RaNCD) cohort study, which involved 8,360 adults. Participants with a Fatty Liver Index (FLI) score of ≥ 60 was classified as having NAFLD. The FLI score was calculated using liver non-invasive markers and anthropometric measurements. Participants were categorized into four phenotypes based on the presence or absence of metabolic syndrome and obesity. Logistic regression analysis was used to evaluate the association of NAFLD and obesity phenotypes.

RESULTS

According to the FLI index, the prevalence of NAFLD was 39.56%. Participants with FLI scores of ≥ 60 had higher energy intake compared to those in the FLI < 60 group (P = 0.033). In subjects with metabolically unhealthy phenotypes, the level of physical activity was lower compared to those with metabolically healthy phenotypes. The risk of NAFLD in males with the metabolically healthy-obese phenotype increased by 8.92 times (95% CI: 2.20, 15.30), those with the metabolically unhealthy-non-obese phenotype increased by 7.23 times (95% CI: 5.82, 8.99), and those with the metabolically unhealthy-obese phenotype increased by 32.97 times (95% CI: 15.70, 69.22) compared to the metabolically healthy-non-obese phenotype. Similarly, these results were observed in females.

CONCLUSION

This study demonstrated that the risk of NAFLD is higher in individuals with metabolically healthy/obese, metabolically unhealthy/non-obese, and metabolically unhealthy/obese phenotypes compared to those with non-obese/metabolically healthy phenotypes.

Binary Bacillus subtilis protects the intestinal mucosa barrier and alleviates nonalcoholic steatohepatitis

BACKGROUND

Nonalcoholic steatohepatitis (NASH) is characterized by liver steatosis, inflammation, and even fibrosis. NASH is likely to develop into cirrhosis and liver cancer, the major causes of liver related deaths. We aimed to study the effect of probiotics on NASH via the gut-liver axis.

METHODS

Thirty male Sprague-Dawley rats were divided into three groups. A control group of 10 rats was fed on a standard chow for 16 weeks. Twenty rats fed on a high-fat diet for 8 weeks were separated to two groups: a model group (10 rats) fed on vehicle for 8 weeks and a treatment group (10 rats) supplemented with binary Bacillus subtilis for 8 weeks. Hepatic expression of IL-6 and TNF-ɑ and ileum expression of IL-17 and occludin were measured.

RESULTS

The high-fat diet caused inflammation of the liver and ileum in rats. Binary Bacillus subtilis treatment reduces liver inflammation through the intestinal liver axis. Increased levels of IL-6 and TNF-α were detected in rats fed a high-fat diet, which were reduced to lower levels after treatment with binary Bacillus subtilis. In rats on the high-fat diet, elevated IL-17 levels and decreased occludin levels were observed. Treatment with Bacillus subtilis reduced IL-17 levels and restored the expression of occludin.

CONCLUSION

Binary Bacillus subtilis has a beneficial effect on liver inflammation and intestinal damage.

Gut symbionts alleviate MASH through a secondary bile acid biosynthetic pathway

The gut microbiota has been found to play an important role in the progression of metabolic dysfunction-associated steatohepatitis (MASH), but the mechanisms have not been established. Here, by developing a click-chemistry-based enrichment strategy, we identified several microbial-derived bile acids, including the previously uncharacterized 3-succinylated cholic acid (3-sucCA), which is negatively correlated with liver damage in patients with liver-tissue-biopsy-proven metabolic dysfunction-associated fatty liver disease (MAFLD). By screening human bacterial isolates, we identified Bacteroides uniformis strains as effective producers of 3-sucCA both in vitro and in vivo. By activity-based protein purification and identification, we identified an enzyme annotated as β-lactamase in B. uniformis responsible for 3-sucCA biosynthesis. Furthermore, we found that 3-sucCA is a lumen-restricted metabolite and alleviates MASH by promoting the growth of Akkermansia muciniphila. Together, our data offer new insights into the gut microbiota-liver axis that may be leveraged to augment the management of MASH.

Hepatic steatosis modeling and MRI signal simulations for comparison of single- and dual-R2* models and estimation of fat fraction at 1.5T and 3T

BACKGROUND AND OBJECTIVE

Magnetic resonance imaging (MRI) has emerged as a noninvasive clinical tool for assessment of hepatic steatosis. Multi-spectral fat-water MRI models, incorporating single or dual transverse relaxation decay rate(s) (R2*) have been proposed for accurate fat fraction (FF) estimation. However, it is still unclear whether single- or dual-R2* model accurately mimics in vivo signal decay for precise FF estimation and the impact of signal-to-noise ratio (SNR) on each model performance. Hence, this study aims to construct virtual steatosis models and synthesize MRI signals with different SNRs to systematically evaluate the accuracy of single- and dual-R2* models for FF and R2* estimations at 1.5T and 3.0T.

METHODS

Realistic hepatic steatosis models encompassing clinical FF range (0-60 %) were created using morphological features of fat droplets (FDs) extracted from human liver biopsy samples. MRI signals were synthesized using Monte Carlo simulations for noise-free (SNRideal) and varying SNR conditions (5-100). Fat-water phantoms were scanned with different SNRs to validate simulation results. Fat water toolbox was used to calculate R2* and FF for both single- and dual-R2* models. The model accuracies in R2* and FF estimates were analyzed using linear regression, bias plot and heatmap analysis.

RESULTS

The virtual steatosis model closely mimicked in vivo fat morphology and Monte Carlo simulation produced realistic MRI signals. For SNRideal and moderate-high SNRs, water R2* (R2*W) by dual-R2* and common R2* (R2*com) by single-R2* model showed an excellent agreement with slope close to unity (0.95-1.01) and R2 > 0.98 at both 1.5T and 3.0T. In simulations, the R2*com-FF and R2*W-FF relationships exhibited slopes similar to in vivo calibrations, confirming the accuracy of our virtual models. For SNRideal, fat R2* (R2*F) was similar to R2*W and dual-R2* model showed slightly higher accuracy in FF estimation. However, in the presence of noise, dual-R2* produced higher FF bias with decreasing SNR, while leading to only marginal improvement for high SNRs and in regions dominated by fat and water. In contrast, single-R2* model was robust and produced accurate FF estimations in simulations and phantom scans with clinical SNRs.

CONCLUSION

Our study demonstrates the feasibility of creating virtual steatosis models and generating MRI signals that mimic in vivo morphology and signal behavior. The single-R2* model consistently produced lower FF bias for clinical SNRs across entire FF range compared to dual-R2* model, hence signifying that single-R2* model is optimal for assessing hepatic steatosis.

Autophagy and the unfolded protein response shape the non-alcoholic fatty liver landscape: decoding the labyrinth

The incidence of nonalcoholic fatty liver disease (NAFLD) is on the rise, mirroring a global surge in diabetes and metabolic syndrome, as its major leading causes. NAFLD represents a spectrum of liver disorders, ranging from nonalcoholic fatty liver (NAFL) to nonalcoholic steatohepatitis (NASH), which can potentially progress to cirrhosis and hepatocellular carcinoma (HCC). Mechanistically, we know the unfolded protein response (UPR) as a protective cellular mechanism, being triggered under circumstances of endoplasmic reticulum (ER) stress. The hepatic UPR is turned on in a broad spectrum of liver diseases, including NAFLD. Recent data also defines molecular mechanisms that may underlie the existing correlation between UPR activation and NAFLD. More interestingly, subsequent studies have demonstrated an additional mechanism, i.e. autophagy, to be involved in hepatic steatosis, and thus NAFLD pathogenesis, principally by regulating the insulin sensitivity, hepatocellular injury, innate immunity, fibrosis, and carcinogenesis. All these findings suggest possible mechanistic roles for autophagy in the progression of NAFLD and its complications. Both UPR and autophagy are dynamic and interconnected fluxes that act as protective responses to minimize the harmful effects of hepatic lipid accumulation, as well as the ER stress during NAFLD. The functions of UPR and autophagy in the liver, together with findings of decreased hepatic autophagy in correlation with conditions that predispose to NAFLD, such as obesity and aging, suggest that autophagy and UPR, alone or combined, may be novel therapeutic targets against the disease. In this review, we discuss the current evidence on the interplay between autophagy and the UPR in connection to the NAFLD pathogenesis.