BACKGROUND: High-fat diets cause gut dysbiosis and promote triglyceride accumulation, obesity, gut permeability changes, inflammation, and insulin resistance. Both cocoa butter and fish oil are considered to be a part of healthy diets. However, their differential effects on gut microbiome perturbations in mice fed high concentrations of these fats, in the absence of sucrose, remains to be elucidated. The aim of the study was to test whether the sucrose-free cocoa butter-based high-fat diet (C-HFD) feeding in mice leads to gut dysbiosis that associates with a pathologic phenotype marked by hepatic steatosis, low-grade inflammation, perturbed glucose homeostasis, and insulin resistance, compared with control mice fed the fish oil based high-fat diet (F-HFD).
RESULTS: C57BL/6 mice (5-6 mice/group) were fed two types of high fat diets (C-HFD and F-HFD) for 24 weeks. No significant difference was found in the liver weight or total body weight between the two groups. The 16S rRNA sequencing of gut bacterial samples displayed gut dysbiosis in C-HFD group, with differentially-altered microbial diversity or relative abundances. Bacteroidetes, Firmicutes, and Proteobacteria were highly abundant in C-HFD group, while the Verrucomicrobia, Saccharibacteria (TM7), Actinobacteria, and Tenericutes were more abundant in F-HFD group. Other taxa in C-HFD group included the Bacteroides, Odoribacter, Sutterella, Firmicutes bacterium (AF12), Anaeroplasma, Roseburia, and Parabacteroides distasonis. An increased Firmicutes/Bacteroidetes (F/B) ratio in C-HFD group, compared with F-HFD group, indicated the gut dysbiosis. These gut bacterial changes in C-HFD group had predicted associations with fatty liver disease and with lipogenic, inflammatory, glucose metabolic, and insulin signaling pathways. Consistent with its microbiome shift, the C-HFD group showed hepatic inflammation and steatosis, high fasting blood glucose, insulin resistance, increased hepatic de novo lipogenesis (Acetyl CoA carboxylases 1 (Acaca), Fatty acid synthase (Fasn), Stearoyl-CoA desaturase-1 (Scd1), Elongation of long-chain fatty acids family member 6 (Elovl6), Peroxisome proliferator-activated receptor-gamma (Pparg) and cholesterol synthesis (β-(hydroxy β-methylglutaryl-CoA reductase (Hmgcr). Non-significant differences were observed regarding fatty acid uptake (Cluster of differentiation 36 (CD36), Fatty acid binding protein-1 (Fabp1) and efflux (ATP-binding cassette G1 (Abcg1), Microsomal TG transfer protein (Mttp) in C-HFD group, compared with F-HFD group. The C-HFD group also displayed increased gene expression of inflammatory markers including Tumor necrosis factor alpha (Tnfa), C-C motif chemokine ligand 2 (Ccl2), and Interleukin-12 (Il12), as well as a tendency for liver fibrosis.
CONCLUSIONS: These findings suggest that the sucrose-free C-HFD feeding in mice induces gut dysbiosis which associates with liver inflammation, steatosis, glucose intolerance and insulin resistance.

UNASSIGNED: After pancreaticoduodenectomy, 20-40% of patients develop steatotic liver disease (SLD), and steatohepatitis can be a problem. Although patatin-like phospholipase domain-containing 3 protein (PNPLA3) and transmembrane 6 superfamily member 2 (TM6SF2) polymorphisms are involved in SLD and steatohepatitis development, whether this is the case after pancreaticoduodenectomy is unclear.
UNASSIGNED: Forty-three patients with pancreatic cancer who underwent pancreaticoduodenectomy at our hospital between April 1, 2018, and March 31, 2021, were included. We extracted DNA from noncancerous areas of residual specimens after pancreaticoduodenectomy and determined PNPLA3 and TM6SF2 gene polymorphisms using real-time polymerase chain reaction. SLD was defined as a liver with an attenuation value of ≤40 HU or a liver-to-spleen ratio of ≤0.9 on computed tomography. We defined high hepatic fibrosis indexes (HFI) instead of steatohepatitis as a Fibrosis-4 index of ≥2.67 or nonalcoholic fatty liver disease fibrosis score of ≥0.675 in patients with SLD. The cumulative incidence of SLD (P = 0.299) and high HFI (P = 0.987) after pancreaticoduodenectomy were not significantly different between the PNPLA3 homozygous and minor allele groups. The incidences of high HFI at 1 year after pancreaticoduodenectomy were 16.8% and 27.0% in the TM6SF2 major homozygous and minor allele groups, respectively, with a significant difference in the cumulative incidence (P = 0.046).
UNASSIGNED: The TM6SF2 minor allele may contribute to steatohepatitis development after pancreaticoduodenectomy.

OBJECTIVE: We aimed to assess the role of FGF21 in metabolic dysfunction-associated steatotic liver disease (MASLD) at a multi-scale level.
METHODS: We used human MASLD pathology samples for FGF21 gene expression analyses (qPCR and RNAseq), serum to measure circulating FGF21 levels and DNA for genotyping the FGF21 rs838133 variant in both estimation and validation cohorts. A hepatocyte-derived cell line was exposed to free fatty acids at different timepoints. Finally, C57BL/6J mice were fed a high-fat and choline-deficient diet (CDA-HFD) for 16 weeks to assess hepatic FGF21 protein expression and FGF21 levels by ELISA.
RESULTS: A significant upregulation in FGF21 mRNA expression was observed in the liver analysed by both qPCR (fold change 5.32 ± 5.25 vs. 0.59 ± 0.66; p = 0.017) and RNA-Seq (3.5 fold; FDR: 0.006; p < 0.0001) in MASLD patients vs. controls. Circulating levels of FGF21 were increased in patients with steatohepatitis vs. bland steatosis (386.6 ± 328.9 vs. 297.9 ± 231.5 pg/mL; p = 0.009). Besides, sex, age, A-allele from FGF21, GG genotype from PNPLA3, ALT, type 2 diabetes mellitus and BMI were independently associated with MASH and significant fibrosis in both estimation and validation cohorts. In vitro exposure of Huh7.5 cells to high concentrations of free fatty acids (FFAs) resulted in overexpression of FGF21 (p < 0.001). Finally, Circulating FGF21 levels and hepatic FGF21 expression were found to be significantly increased (p < 0.001) in animals under CDA-HFD.
CONCLUSIONS: Hepatic and circulating FGF21 expression was increased in MASH patients, in Huh7.5 cells under FFAs and in CDA-HFD animals. The A-allele from the rs838133 variant was also associated with an increased risk of steatohepatitis and significant and advanced fibrosis in MASLD patients.

Metabolic dysfunction-associated steatotic liver disease (MASLD) is characterized by intense deposition of fat globules in the hepatic parenchyma that could potentially progress to liver cirrhosis and hepatocellular carcinoma. Here, we evaluated a rat model to study the molecular pathogenesis of the spectrum of MASLD and to screen therapeutic agents. SHRSP5/Dmcr rats were fed a high-fat and cholesterol (HFC) diet for a period of 12 weeks and evaluated for the development of steatosis (MASLD), steatohepatitis, fibrosis and cirrhosis. A group of animals were sacrificed at the end of the 4th, 6th, 8th and 12th weeks from the beginning of the experiment, along with the control rats that received normal diet. Blood and liver samples were collected for biochemical and histopathological evaluations. Immunohistochemical staining was performed for α-SMA and Collagen Type I. Histopathological examinations demonstrated steatosis at the 4th week, steatohepatitis with progressive fibrosis at the 6th week, advanced fibrosis with bridging at the 8th week and cirrhosis at the 12th week. Biochemical markers and staining for α-SMA and Collagen Type I demonstrated the progression of steatosis to steatohepatitis, hepatic fibrosis and liver cirrhosis in a stepwise manner. Control animals fed a normal diet did not show any biochemical or histopathological alterations. The results of the present study clearly demonstrated that the HFC diet-induced model of steatosis, steatohepatitis, hepatic fibrosis and cirrhosis is a feasible, quick and appropriate animal model to study the molecular pathogenesis of the spectrum of MASLD and to screen potent therapeutic agents.

Metabolic dysfunction-associated steatotic liver disease (MASLD) is hallmarked by hepatic steatosis, cell injury, inflammation, and fibrosis. This study elaborates on a multicellular biochip-based liver sinusoid model to mimic MASLD pathomechanisms and investigate the therapeutic effects of drug candidates lanifibranor and resmetirom. Mouse liver primary hepatocytes, hepatic stellate cells, Kupffer cells, and endothelial cells are seeded in a dual-chamber biocompatible liver-on-a-chip (LoC). The LoC is then perfused with circulating immune cells (CICs). Acetaminophen (APAP) and free fatty acids (FFAs) treatment recapitulate acute drug-induced liver injury and MASLD, respectively. As a benchmark for the LoC, multiplex immunofluorescence on livers from APAP-injected and dietary MASLD-induced mice reveals characteristic changes on parenchymal and immune cell populations. APAP exposure induces cell death in the LoC, and increased inflammatory cytokine levels in the circulating perfusate. Under FFA stimulation, lipid accumulation, cellular damage, inflammatory secretome, and fibrogenesis are increased in the LoC, reflecting MASLD. Both injury conditions potentiate CIC migration from the perfusate to the LoC cellular layers. Lanifibranor prevents the onset of inflammation, while resmetirom decreases lipid accumulation in hepatocytes and increases the generation of FFA metabolites in the LoC. This study demonstrates the LoC potential for functional and molecular evaluation of liver disease drug candidates.

Introduction: Current guidelines recommend the use of glucagon-like peptide-1 receptor agonists (GLP-1RAs) in the treatment of metabolic dysfunction-associated steatotic liver disease (MASLD), especially in patients with comorbid diabetes and obesity. This study investigated the effects of GLP-1RAs on hepatic steatosis and fibrosis in patients with MASLD, as measured by changes in vibration-controlled transient elastography (VCTE) and other clinical parameters in a real-world clinical setting. Methods: We conducted a single-center, retrospective analysis of 96 patients with MASLD from a multidisciplinary care clinic who completed VCTE at baseline and follow-up within 6-24 months to compare changes in controlled attenuation parameter (CAP) and liver stiffness measurement (LSM), as well as other metabolic markers, between GLP-1RA users and nonusers using two-sample t-tests and Wilcoxon rank-sum tests. We also assessed whether improvements in hepatic steatosis, defined as a change in CAP >38 dB/m as previously described in the literature, were associated with improvement in fibrosis. Results: GLP-1RA use resulted in significant improvements in weight (-8.1 kg vs. -3.5 kg, P = 0.009), body mass index (BMI) (-2.9 kg/m2 vs. -1.3 kg/m2, P = 0.012), alanine aminotransferase (-15.0 IU/L vs. -4.0 IU/L, P = 0.017), aspartate aminotransferase (-5.0 IU/L vs. -1.0 IU/L, P = 0.021), glycated hemoglobin (HbA1c) (-0.7% vs. 0.1%, P = 0.019), and CAP (-59.9 dB/m vs. -29.1 dB/m, P = 0.016). Responders also had significant improvements in weight (-9.2 kg vs. -1.9 kg, P < 0.001), BMI (-3.3 kg/m2 vs. -0.7 kg/m2, P < 0.001), diastolic blood pressure (-6.1 mmHg vs. -0.7 mmHg, P = 0.028), HbA1c (-0.8% vs. 0.3%, P < 0.001), and LSM (-1.5 kPa vs. 0.1 kPa, P < 0.001). Conclusions: Patients with MASLD treated with GLP-1RAs showed significant improvements in hepatic steatosis and multiple other metabolic parameters, with weight loss as the proposed mechanism for this liver improvement. In addition, change in CAP >38 dB/m was associated with improvements in LSM and other metabolic parameters, suggesting the clinical utility of VCTE in the surveillance of MASLD.

BACKGROUND: Genetic testing can be used to evaluate disease risk. We evaluated if the use of three Single Nucleotide Polymorphisms (SNPs), alone or combined into a genetic risk score (GRS), can aid identify significant fibrosis in subjects with metabolic dysfunction-associated steatotic liver disease (MASLD).
METHODS: We assessed three known risk variants: PNPLA3 rs738409, TM6SF2 rs58542926, and HSD17B13 rs72613567. The study included 414 adult individuals invited from the Danish population, who were defined as at-risk of MASLD due to elevated ALT and body mass index (BMI) >25 kg/m2. Participants were assessed clinically and by the Fibrosis-4 (FIB-4) index and Fibroscan.
RESULTS: In total, 17 participants (4.1 %) had alcohol-related liver disease, 79 (19.1 %) had no evidence of liver disease, and four (1.0 %) were diagnosed with other liver diseases, including malignant disease. The remaining 314 participants (75.8 %) were diagnosed with MASLD. Of the 27 who underwent a liver biopsy for suspected fibrosis, 15 had significant fibrosis (≥F2) and 12 had no/mild fibrosis (F0/F1). The GRS was not associated with significant fibrosis (p = 0.09) but PNPLA3 was with an odds ratio of 6.75 (95 % CI 1.29 - 50.7; p = 0.039) risk allele CG/GG versus CC. The diagnostic accuracy of PNPLA3 combined with an increased Fib-4 (>1.3) was excellent for detecting significant fibrosis with a sensitivity of 1.00 (95 % CI 0.72-1.00), but the specificity was no better than for FIB-4 alone.
CONCLUSIONS: This study found no evidence to support the use of GRS for diagnosing significant fibrosis in MASLD. However, the combination of PNPLA3 and Fib-4 increased sensitivity considerably. In addition, ALT remains a useful tool for screening diagnosing other liver diseases than MASLD.

Liver fibrosis is a pathological condition characterized by the abnormal proliferation of liver tissue, subsequently able to progress to cirrhosis or possibly hepatocellular carcinoma. The development of artificial intelligence and deep learning have begun to play a significant role in fibrosis detection. This study aimed to develop SMART AI-PATHO, a fully automated assessment method combining quantification of histopathological architectural features, to analyze steatosis and fibrosis in nonalcoholic fatty liver disease (NAFLD) core biopsies and employ Metavir fibrosis staging as standard references and fat assessment grading measurement for comparison with the pathologist interpretations. There were 146 participants enrolled in our study. The correlation of Metavir scoring system interpretation between pathologists and SMART AI-PATHO was significantly correlated (Agreement = 68%, Kappa = 0.59, p-value <0.001), which subgroup analysis of significant fibrosis (Metavir score F2-F4) and nonsignificant fibrosis (Metavir score F0-F1) demonstrated substantial correlated results (agreement = 80%, kappa = 0.61, p-value <0.001), corresponding with the correlation of advanced fibrosis (Metavir score F3-F4) and nonadvanced fibrosis groups (Metavir score F0-F2), (agreement = 89%, kappa = 0.74, p-value <0.001). SMART AI-PATHO, the first pivotal artificially intelligent diagnostic tool for the color-based NAFLD hepatic tissue staging in Thailand, demonstrated satisfactory performance as a pathologist to provide liver fibrosis scoring and steatosis grading. In the future, developing AI algorithms and reliable testing on a larger scale may increase accuracy and contribute to telemedicine consultations for general pathologists in clinical practice.

Excessive lipid deposition affects hepatic homeostasis and contributes to the development of insulin resistance as a crucial factor for the deterioration of simple steatosis to steatohepatitis. So, it is essential to search for an effective agent for a new therapy for hepatic steatosis development before it progresses to the more advanced stages. Our study aimed to evaluate the potential protective effect of α-lipoic acid (α-LA) administration on the intrahepatic metabolism of sphingolipid and insulin signaling transduction in rats with metabolic dysfunction-associated steatotic liver disease (MASLD). The experiment was conducted on male Wistar rats subjected to a standard diet or a high-fat diet (HFD) and an intragastrically α-LA administration for eight weeks. High-performance liquid chromatography (HPLC) was used to determine sphingolipid content. Immunoblotting was used to measure the expression of selected proteins from sphingolipid and insulin signaling pathways. Multiplex assay kit was used to assess the level of the phosphorylated form of proteins from PI3K/Akt/mTOR transduction. The results revealed that α-LA decreased sphinganine, dihydroceramide, and sphingosine levels and increased ceramide level. We also observed an increased the concentration of phosphorylated forms of sphingosine and sphinganine. Changes in the expression of proteins from sphingolipid metabolism were consistent with changes in sphingolipid pools. Treatment with α-LA activated the PI3K/Akt/mTOR pathway, which enhanced the hepatic phosphorylation of Akt and mTOR. Based on these data, we concluded that α-lipoic acid may alleviate glucose intolerance and may have a protective influence on the sphingolipid metabolism under HFD; thus, this antioxidant appears to protect from MASLD development and steatosis deterioration.

Drug induced fatty liver disease (DIFLD) is a form of drug-induced liver injury (DILI), which can also be included in the more general metabolic dysfunction-associated steatotic liver disease (MASLD), which specifically refers to the accumulation of fat in the liver unrelated to alcohol intake. A bi-directional relationship between DILI and MASLD is likely to exist: while certain drugs can cause MASLD by acting as pro-steatogenic factors, MASLD may make hepatocytes more vulnerable to drugs. Having a pre-existing MASLD significantly heightens the likelihood of experiencing DILI from certain medications. Thus, the prevalence of steatosis within DILI may be biased by pre-existing MASLD, and it can be concluded that the genuine true incidence of DIFLD in the general population remains unknown. In certain individuals, drug-induced steatosis is often accompanied by concomitant injury mechanisms such as oxidative stress, cell death, and inflammation, which leads to the development of drug-induced steatohepatitis (DISH). DISH is much more severe from the clinical point of view, has worse prognosis and outcome, and resembles MASH (metabolic-associated steatohepatitis), as it is associated with inflammation and sometimes with fibrosis. A literature review of clinical case reports allowed us to examine and evaluate the clinical features of DIFLD and their association with specific drugs, enabling us to propose a classification of DIFLD drugs based on clinical outcomes and pathological severity: Group 1, drugs with low intrinsic toxicity (e.g., ibuprofen, naproxen, acetaminophen, irinotecan, methotrexate, and tamoxifen), but expected to promote/aggravate steatosis in patients with pre-existing MASLD; Group 2, drugs associated with steatosis and only occasionally with steatohepatitis (e.g., amiodarone, valproic acid, and tetracycline); and Group 3, drugs with a great tendency to transit to steatohepatitis and further to fibrosis. Different mechanisms may be in play when identifying drug mode of action: (1) inhibition of mitochondrial fatty acid β-oxidation; (2) inhibition of fatty acid transport across mitochondrial membranes; (3) increased de novo lipid synthesis; (4) reduction in lipid export by the inhibition of microsomal triglyceride transfer protein; (5) induction of mitochondrial permeability transition pore opening; (6) dissipation of the mitochondrial transmembrane potential; (7) impairment of the mitochondrial respiratory chain/oxidative phosphorylation; (8) mitochondrial DNA damage, degradation and depletion; and (9) nuclear receptors (NRs)/transcriptomic alterations. Currently, the majority of, if not all, adverse outcome pathways (AOPs) for steatosis in AOP-Wiki highlight the interaction with NRs or transcription factors as the key molecular initiating event (MIE). This perspective suggests that chemical-induced steatosis typically results from the interplay between a chemical and a NR or transcription factors, implying that this interaction represents the primary and pivotal MIE. However, upon conducting this exhaustive literature review, it became evident that the current AOPs tend to overly emphasize this interaction as the sole MIE. Some studies indeed support the involvement of NRs in steatosis, but others demonstrate that such NR interactions alone do not necessarily lead to steatosis. This view, ignoring other mitochondrial-related injury mechanisms, falls short in encapsulating the intricate biological mechanisms involved in chemically induced liver steatosis, necessitating their consideration as part of the AOP\'s map road as well.