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While macrophage heterogeneity during metabolic dysfunction-associated steatohepatitis (MASH) has been described, the fate of these macrophages during MASH regression is poorly understood. Comparing macrophage heterogeneity during MASH progression vs regression, we identified specific macrophage subpopulations that are critical for MASH/fibrosis resolution. We elucidated the restorative pathways and gene signatures that define regression-associated macrophages and establish the importance of TREM2+ macrophages during MASH regression. Liver-resident Kupffer cells are lost during MASH and are replaced by four distinct monocyte-derived macrophage subpopulations. Trem2 is expressed in two macrophage subpopulations: i) monocyte-derived macrophages occupying the Kupffer cell niche (MoKC) and ii) lipid-associated macrophages (LAM). In regression livers, no new transcriptionally distinct macrophage subpopulation emerged. However, the relative macrophage composition changed during regression compared to MASH. While MoKC was the major macrophage subpopulation during MASH, they decreased during regression. LAM was the dominant macrophage subtype during MASH regression and maintained Trem2 expression. Both MoKC and LAM were enriched in disease-resolving pathways. Absence of TREM2 restricted the emergence of LAMs and formation of hepatic crown-like structures. TREM2+ macrophages are functionally important not only for restricting MASH-fibrosis progression but also for effective regression of inflammation and fibrosis. TREM2+ macrophages are superior collagen degraders. Lack of TREM2+ macrophages also prevented elimination of hepatic steatosis and inactivation of HSC during regression, indicating their significance in metabolic coordination with other cell types in the liver. TREM2 imparts this protective effect through multifactorial mechanisms, including improved phagocytosis, lipid handling, and collagen degradation.

BACKGROUND: Steatohepatitis is common in persons living with HIV and may be associated with gut microbial translocation (MT). However, few studies have evaluated the gut-liver axis in persons living with HIV. In the Womens Interagency HIV Study, we examined the associations of HIV and circulating biomarkers linked to MT and gut damage using the FibroScan-aspartate aminotransferase (FAST) score, a noninvasive surrogate for steatohepatitis with advanced fibrosis. METHODS: Among 883 women with HIV and 354 without HIV, we used multivariable regression to examine the associations of HIV and serum biomarkers linked to MT and gut damage (kynurenine and tryptophan ratio, intestinal fatty acid-binding protein, soluble CD14, and soluble CD163) with a log-transformed FAST score after adjusting for key covariates. We used a path analysis and mediation models to determine the mediating effect of each biomarker on the association of HIV with FAST. RESULTS: HIV infection was associated with a 49% higher FAST score. MT biomarker levels were higher in women with HIV than women without HIV (P < .001 for each). MT biomarkers mediated 13% to 32% of the association of HIV and FAST score. CONCLUSIONS: Biomarkers linked to MT and gut damage are associated with a higher FAST score and mediate the association of HIV with a higher FAST score. Our findings suggest that MT may be an important mechanism by which HIV increases the risk of steatohepatitis with advanced fibrosis.

Mammalian ferredoxin 1 and 2 (FDX1/2) belong to an evolutionary conserved family of iron-sulfur cluster containing proteins and act as electron shutters between ferredoxin reductase (FDXR) and numerous proteins involved in critical biological pathways. FDX1 is involved in biogenesis of steroids and bile acids, Vitamin A/D metabolism, and lipoylation of tricarboxylic acid (TCA) cycle enzymes. FDX1 has been extensively characterized biochemically but its role in physiology and lipid metabolism has not been explored. In this study, we generated Fdx1-deficient mice and showed that knockout of both alleles of the Fdx1 gene led to embryonic lethality. We also showed that like Fdxr+/-+/-, Fdx1+/-+/- had a shorter life span and were prone to steatohepatitis. However, unlike Fdxr+/-+/-, Fdx1+/-+/- were not prone to spontaneous tumors. Additionally, we showed that FDX1 deficiency led to lipid droplet accumulation possibly via the ABCA1-SREBP1/2 pathway. Specifically, untargeted lipidomic analysis showed that FDX1 deficiency led to alterations in several classes of lipids, including cholesterol, triacylglycerides, acylcarnitines, ceramides, phospholipids and lysophospholipids. Taken together, our data indicate that FDX1 is essential for mammalian embryonic development and lipid homeostasis at both cellular and organismal levels.

Background: Mitochondrial calcium uniporter (MCU) plays pleiotropic roles in cellular physiology and pathology that contributes to a variety of diseases, but the role and potential mechanism of MCU in the pathogenesis of metabolic dysfunction-associated steatohepatitis (MASH) remain poorly understood. Methods and results: Here, hepatic knockdown of MCU in C57BL/6J mice was achieved by tail vein injection of AAV8-mediated the CRISPR/Cas9. Mice were fed a Choline-deficient, L-amino acid-defined high-fat diet (CDAHFD) for 8 weeks to induce MASH and fibrosis. We find that expression of MCU enhanced in MASH livers of humans and mice. MCU knockdown robustly limits lipid droplet accumulation, steatosis, inflammation, and hepatocyte apoptotic death during MASH development both in vivo in mice and in vitro in cellular models. MCU-deficient mice strikingly mitigate MASH-related fibrosis. Moreover, the protective effects of MCU knockdown against MASH progression are accompanied by a reduced level of mitochondrial calcium, limiting hepatic oxidative stress, and attenuating mitochondrial dysfunction. Mechanically, RNA sequencing analysis and protein immunoblotting indicate that knockdown MCU inhibited the Hippo/YAP pathway activation and restored the AMP-activated protein kinase (AMPK) activity during MASH development both in vitro and in vivo. Conclusions: MCU is up-regulated in MASH livers in humans and mice; and hepatic MCU knockdown protects against diet-induced MASH and fibrosis in mice. Thus, targeting MCU may represent a novel therapeutic strategy for MASH and fibrosis. [ABSTRACT FROM AUTHOR]

In recent years, there has been a rapid expansion in our understanding of regulated cell death, leading to the discovery of novel mechanisms that govern diverse cell death pathways. One recently discovered type of cell death is pyroptosis, initially identified in the 1990s as a caspase-1-dependent lytic cell death. However, further investigations have redefined pyroptosis as a regulated cell death that relies on the activation of pore-forming proteins, particularly the gasdermin family. Among the key regulators of pyroptosis is the inflammasome sensor NOD-like receptor 3 (NLRP3), a critical innate immune sensor responsible for regulating the activation of caspase-1 and gasdermin D. A deeper understanding of pyroptosis and its interplay with other forms of regulated cell death is emerging, shedding light on a complex regulatory network controlling pore-forming proteins and cell fate. Cell death processes play a central role in diseases such as metabolic dysfunction-associated steatotic liver disease, metabolic dysfunction-associated steatohepatitis, autoinflammatory disorders, and cancer. Cell death often acts as a starting point in these diseases, making it an appealing target for drug development. Yet, the complete molecular mechanisms are not fully understood, and new discoveries reveal promising novel avenues for therapeutic interventions. In this review, we summarize recent evidence on pathways and proteins controlling pyroptosis and gasdermins. Furthermore, we will address the role of pyroptosis and the gasdermin family in metabolic dysfunction-associated steatotic liver disease and steatohepatitis. Additionally, we highlight new potential therapeutic targets for treating metabolic dysfunction-associated steatohepatitis and other inflammatory-associated diseases. [ABSTRACT FROM AUTHOR]

Metabolic dysfunction-associated fatty liver disease (MAFLD) and viral hepatitis due to chronic hepatitis B virus (HBV) or hepatitis C virus (HCV) infection are common liver diseases worldwide. Excessive alcohol consumption and alcoholic liver disease (ALD) are also emerging health problems. Therefore, in clinical practice, we may encounter subjects with dual etiology of liver diseases such as coexisting MAFLD/HBV, MAFLD/HCV, and MAFLD/ALD. In this review, we summarize the epidemiology, clinical features, and mutual interactions of MAFLD with coexisting HBV, HCV, or ALD. The impact of MAFLD on the progression of liver diseases and treatment outcomes in patients with chronic viral hepatitis and the clinical questions to be addressed regarding dual MAFLD and ALD are also discussed. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Metabolic dysfunction–associated steatotic liver disease (MASLD) has been proposed as a new name for the previous non-alcoholic fatty liver disease (NAFLD). There are some differences between MASLD and NAFLD, e.g., diagnostic criteria. MASLD is a hepatic steatosis without harmful alcohol consumption and is caused by metabolic factors. The prevalence of MASLD varies amongst different populations. The change in lifestyle plays a fundamental role in MASLD management, while there is no registered pharmacotherapy in this indication. Sodium-glucose co-transporter 2 inhibitors (SGLT2i) have been suggested to have a beneficial effect on hepatic steatosis, hence, they have been widely investigated as potential therapeutics in MASLD. In this review, we aimed to thoroughly summarize current evidence from original research about the effects of SGLT2i use on MASLD. Almost all discussed studies advocate using SGLT2i in MASLD because of their beneficial effects. It includes the loss of body weight, which is beneficial per se, and the improvement in hepatic parameters. Most importantly, steatosis reduction has been observed in patients using SGLT2i. We highly recommend further research in this field, which we believe will eventually lead to a new indication for SGLT2i, i.e., MASLD. [ABSTRACT FROM AUTHOR]

Background & aimsMore data are needed regarding the long-term impact of the histological progression of non-alcoholic fatty liver disease (NAFLD) on long-term outcomes, including end-stage liver disease (ESLD) and mortality.MethodsWe included Swedish adults with biopsy-confirmed non-cirrhotic NAFLD and ≥2 liver biopsies >6 months apart (1969-2017; n = 718). NAFLD was categorized at initial biopsy as simple steatosis, non-fibrotic steatohepatitis (NASH), or non-cirrhotic fibrosis. NAFLD progression was defined by histological changes between biopsies (i.e. incident NASH, incident fibrosis, fibrosis progression, cirrhosis). Using Cox regression, we estimated multivariable adjusted hazard ratios (aHRs) and 95% CIs for incident ESLD (i.e. hospitalization for decompensated cirrhosis, hepatocellular carcinoma or liver transplantation) and mortality, according to NAFLD progression vs. stable/regressed disease.ResultsAt initial biopsy, 497 patients (69.2%) had simple steatosis, 90 (12.5%) had non-fibrotic NASH, and 131 (18.2%) had non-cirrhotic fibrosis. Over a median of 3.4 years between biopsies, 30.4% (218/718) experienced NAFLD progression, including 12.5% (62/497) with incident non-fibrotic NASH, 24.0% (141/587) with incident fibrosis, and 5.6% (40/718) with cirrhosis. Compared to stable/regressed disease, NAFLD progression was associated with significantly higher rates of developing incident ESLD (23.8 vs. 11.4/1,000 person-years [PY]; difference = 12.4/1,000 PY; aHR 1.65, 95% CI 1.17-2.32). While the highest ESLD incidence occurred with progression to cirrhosis (difference vs. stable/regressed disease = 56.3/1,000 PY), significant excess risk was also found with earlier transitions, including from simple steatosis to incident fibrosis (difference vs. stable/regressed disease = 18.9/1,000 PY). In contrast, all-cause mortality rates did not appear to differ when NAFLD progression was compared to stable/regressed disease (difference = 4.7/1,000 PY; aHR 0.99, 95% CI 0.78-1.24).ConclusionsIn a nationwide, real-world cohort of patients with paired NAFLD biopsies, histological disease progression contributed to significantly higher rates of developing incident ESLD, but did not appear to impact all-cause mortality.Impact and implicationsCurrently, data are scarce regarding the long-term impact of histological progression or regression of non-alcoholic fatty liver disease (NAFLD) on subsequent risk of adverse clinical outcomes, including the development of end-stage liver disease and mortality. This is particularly important because randomized-controlled trials of NAFLD therapeutics currently focus on short-term histological endpoints as presumed surrogates for those major clinical outcomes. Thus, the results from this study can help inform the optimal design of future NAFLD therapeutic trials, while also providing the necessary evidence base for public health policies focused on preventing the development and progression of NAFLD.

Abstract Background Mitochondrial calcium uniporter (MCU) plays pleiotropic roles in cellular physiology and pathology that contributes to a variety of diseases, but the role and potential mechanism of MCU in the pathogenesis of metabolic dysfunction-associated steatohepatitis (MASH) remain poorly understood. Methods and results Here, hepatic knockdown of MCU in C57BL/6J mice was achieved by tail vein injection of AAV8-mediated the CRISPR/Cas9. Mice were fed a Choline-deficient, L-amino acid-defined high-fat diet (CDAHFD) for 8 weeks to induce MASH and fibrosis. We find that expression of MCU enhanced in MASH livers of humans and mice. MCU knockdown robustly limits lipid droplet accumulation, steatosis, inflammation, and hepatocyte apoptotic death during MASH development both in vivo in mice and in vitro in cellular models. MCU-deficient mice strikingly mitigate MASH-related fibrosis. Moreover, the protective effects of MCU knockdown against MASH progression are accompanied by a reduced level of mitochondrial calcium, limiting hepatic oxidative stress, and attenuating mitochondrial dysfunction. Mechanically, RNA sequencing analysis and protein immunoblotting indicate that knockdown MCU inhibited the Hippo/YAP pathway activation and restored the AMP-activated protein kinase (AMPK) activity during MASH development both in vitro and in vivo. Conclusions MCU is up-regulated in MASH livers in humans and mice; and hepatic MCU knockdown protects against diet-induced MASH and fibrosis in mice. Thus, targeting MCU may represent a novel therapeutic strategy for MASH and fibrosis. Graphical Abstract

Liver diseases cause millions of deaths globally. Current treatments are often limited in effectiveness and availability, driving the search for alternatives. Herbal preparations offer potential hepatoprotective properties. Disrupted gut microbiota is linked to liver disorders. This scoping review aims to explore the effects of herbal preparations on hepatoprotective mechanisms, particularly in the context of non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), and hepatic steatosis, with a focus on gut microbiota modulation. A systematic search was performed using predetermined keywords in four electronic databases (PubMed, Scopus, EMBASE, and Web of Science). A total of 55 studies were included for descriptive analysis, covering study characteristics such as disease model, dietary model, animal model, intervention details, comparators, and study outcomes. The findings of this review suggest that the hepatoprotective effects of herbal preparations are closely related to their interactions with the gut microbiota. The hepatoprotective mechanisms of herbal preparations are shown through their effects on the gut microbiota composition, intestinal barrier, and microbial metabolites, which resulted in decreased serum levels of liver enzymes and lipids, improved liver pathology, inhibition of hepatic fatty acid accumulation, suppression of inflammation and oxidative stress, reduced insulin resistance, and altered bile acid metabolism.

Abstract 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

Aim. To study the characteristics of the fatty acid (FA) profi le of blood serum and erythrocyte membranes in patients with two forms of fatty liver disease (metabolic + alcoholic): steatosis and steatohepatitis with normal transaminase activity.Materials and methods. We examined 33 men (50.7 ± 9.6 years) with fatty liver disease (metabolic and alcoholic) with fi brosis F ≤ 1 (FibroTest). According to the ActiTest results, patients were divided into groups of steatosis – with minimal (A0–1) activity (n = 17) and steatohepatitis – with moderate/severe (A2–3) necroinfl ammatory activity (n = 16). The FA composition of blood serum and erythrocyte membranes was studied using gas chromatography/mass spectrometry Agilent 7000B (Agilent Technologies, Inc., USA). Methods of unpaired statistics using volcano plot and discriminant analysis based on orthogonal least squares (Orthogonal Partial Least Squares Discriminant Analysis, OPLS-DA), ROC analysis were applied.Results. Volcano plot analysis showed that in patients with fatty liver disease (metabolic and alcoholic) with normal transaminase activity, serum levels of stearic C18:0 (p = 0.016), arachidic C20:0 (p = 0.023), ratio saturated / polyunsaturated fatty acids (PUFA) (p = 0.001) were statistically signifi cantly higher in the steatohepatitis group compared with the steatosis group. The total content in the blood serum of all PUFA (p = 0.003), margaric C17:0 (p = 0.011), the sum of two omega-3 PUFA – eicosapentaenoic acid (C20:5n-3) and docosahexaenoic acid (C22:6n-3) (p = 0.04), the total content of all omega-3 PUFA (p = 0.042) were statistically signifi cantly lower in patients with steatohepatitis. OPLS-DA demonstrated fairly accurate separation of steatohepatitis and steatosis using individual FA and their ratios. When individual FA and their ratios were included in the analysis, a model was obtained with AUC = 0.827 (95% confi dence interval 0.499–1.0), sensitivity 82.2% and specifi city 80.7%.Conclusion. FA in blood serum and erythrocyte membranes appear to be promising biomarkers of steatohepatitis with normal levels of transaminases.

Background. One of the priority areas of modern medicine, which unites the interests of various specialists (therapists, cardiologists, gastroenterologists, endocrinologists), is the study of the pathogenesis and clinical manifestations of nonalcoholic fatty liver disease (NAFLD), which is widespread and of unconditional social significance. The search for adequate experimental models of NAFLD that reflect the severity of liver damage is of paramount importance for studying its etiology and pathogenesis.The aim of the study. To compare biochemical and histological changes in experimental models of NAFLD of varying severity.Materials and methods. Two NAFLD model versions were used: a light one – nonalcoholic steatosis (NAS) and a severe variant – non-alcoholic steatohepatitis (NASH). The following biochemical parameters were measured: enzyme activity of alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), alkaline phosphatase (AP), plasma glucose concentration, total protein (TP), total bilirubin (TBil) and its conjugate fraction (CB), plasma concentrations of homocysteine (HC), total cholesterol (TC), triacylglycerides (TG), catalase (Cat), superoxide dismutase (SOD) and malondialdehyde (MDA).Results. When used in a model of steatohepatitis, liver function was impaired to a significantly greater extent than in the model of steatosis; this difference was manifested in a statistically significant increase in ALT, AST, AP, TC, Tbil, MDA (p < 0.001) and a decrease in Cat, SOD (p < 0.05). This is confirmed by the development of more pronounced symptoms of disorders of pigment and lipid metabolism, cytolytic and cholestatic syndromes, significant activation of lipid peroxidation and depression of the antioxidant system when modeling non-alcoholic steatohepatitis. Various degrees of severity of morphological changes in the experimental groups were revealed.Conclusion. The study showed the priority of determining biochemical markers, including the levels of ALT, AST, OBIL, TG, MDA and SOD to optimize laboratory methods for diagnosing the severity of liver dystrophy.The practical originality of the results lies in the optimization of the methodology for laboratory diagnosis of the severity of the pathological process in NAFLD.

The article presents an analysis of publications on myoinositol in order to clarify the possibilities of prescribing drugs based on it. Myoinositol is one of the endogenous human metabolites that has a significant effect on the functioning of cells and tissues of the whole body. The main function of myoinositol and its derivatives is to participate in intracellular signal transmission and ensure the functioning of such important receptors as insulin receptors, catecholamines, metabotropic receptors of various neurotransmitters, growth factors, etc. (Myoinositol is the basis for the synthesis of an important group of signaling molecules, inositol phosphates, which mediate signal transmission from growth factor receptors and neurotransmitters). Most inositol-dependent proteins with known functions are necessary for the vital functions of the cardiovascular, immune system, and connective tissue structure. Equally important is the role of myoinositol in maintaining the functioning of the central nervous system (including neurotrophic and neuroprotective roles), sugar metabolism (primarily the signaling cascade of insulin) and the functioning of the kidneys and liver. Myoinositol subsidies contribute to the prevention of folate-resistant malformations and neuroprotection of the brain under stress.

Der 2. Teil der Übersichtsarbeit zur Diagnostik und Versorgung von Patienten mit Metabolisch assoziierter Steatohepatitis (MASH) thematisiert die Herausforderungen und Empfehlungen unter Berücksichtigung der aktuellen S2k-Leitlinien. Der diagnostische Algorithmus fokussiert auf ein Screening-Verfahren für die Früherkennung von MASH, wobei Hausärzte zentrale Akteure sind. Bei erhöhten Leberwerten oder auffälligem Fatty Liver Index sind weitere Untersuchungen und ggf. die Zuweisung zu einem Facharzt vorgesehen. Besonders bei Risikogruppen wie Personen mit Typ-2-Diabetes, Adipositas oder metabolischem Syndrom ist eine frühzeitige Identifikation essenziell, um präventiv agieren zu können. Eine umfassende Stoffwechseldiagnostik ist Voraussetzung, um die Progression der Erkrankung zu verhindern. Die Versorgungssituation in der Diagnostik von MASH ist allerdings durch eine Reihe von Limitationen gekennzeichnet, darunter die begrenzte Anwendung des Screening-Algorithmus und die Herausforderungen bei der definitiven Diagnosestellung mittels Leberbiopsie. Die Diskrepanz zwischen der diagnos-tizierten Anzahl von MASH-Fällen und der vermuteten Prävalenz deutet auf eine signifikante Anzahl undiagnostizierter Fälle hin, was letztlich auch therapeutische Defizite nach sich zieht.

Abstract Lifestyle modification is the standard of care for nonalcoholic fatty liver disease (NAFLD) patients. We aimed to investigate the efficacy of a short‐term lifestyle modification program in the disease course of Taiwanese nonalcoholic steatohepatitis (NASH) patients with paired biopsies. All patients received a 6‐month, strict multidisciplinary program of lifestyle modifications led by physicians, dieticians, and nursing staff. The histopathological and clinical features were assessed. The endpoints were normalization of transaminase levels, metabolic parameters, a decrease in the NAFLD activity score (NAS) ≥1, and a decrease in the fibrosis stage ≥1. We also aimed to elucidate the predictors associated with disease progression. A total of 37 patients with biopsy‐proven NASH were enrolled. The normalization of transaminase levels increased from 0% to 13.5%. There were also significantly increased proportions of patients with normal total cholesterol, triglyceride, and hemoglobin A1c levels. Fifteen (40.5%) patients had an increased NAS ≥1, whereas 10 (27.0%) patients had NAS regression. Twelve (32.4%) patients had increased fibrosis ≥1 stage. Only 2 (5.4%) patients experienced fibrosis regression. A high fasting plasma glucose (FPG) level was associated with NAS progression. Older age and higher transaminase and FPG levels were factors associated with fibrosis progression. Seven (18.9%) patients achieved a body weight reduction >3%, and 4 (57.1%) of them experienced NAS regression. No significant effect of weight reduction on the progression of fibrosis was observed. The short‐term lifestyle modification program significantly decreased liver enzymes and metabolic parameters in NASH patients. A more precise or intensive program may be needed for fibrosis improvement.

Drug-induced steatohepatitis is considered more serious than drug-induced hepatic steatosis, so that differentiating between the two is crucial in drug development. In addition, early detection of drug-induced steatohepatitis is considered important since recovery is possible with drug withdrawal. However, no method has been established to differentiate between the two. In the development of drug-induced steatohepatitis, reactive oxygen species (ROS) is excessively generated in the liver. It has been reported that ROS can be monitored with electron spin resonance (ESR) and dynamic nuclear polarization-magnetic resonance imaging (DNP-MRI) by using nitroxyl radicals, which are known to participate in various in vivo redox reactions. The decay/reduction rate, which is an index for monitoring nitroxyl radicals, has been reported to be increased in tissues with excessive ROS levels other than liver, but decreased in methionine choline deficient (MCD) diet-induced steatohepatitis with excess ROS. Therefore, looking to differentiate between drug-induced hepatic steatosis and steatohepatitis, we examined whether the reduction rate decreases in steatohepatitis other than the MCD-diet induced disease and whether the decrease could be detected by MRI. We used STAM™ mice in which hepatic steatosis and steatohepatitis developed sequentially under diabetic conditions. 3-carbamoyl-PROXYL (CmP), one of the nitroxyl radicals, was injected intravenously during the MRI procedure and the reduction rate was calculated. The reduction rate was significantly higher in early steatohepatitis than in hepatic steatosis and the control. Excess ROS in early steatohepatitis was detected by an immunohistochemical marker for ROS. Therefore, it was indicated that the increase or decrease in the reduction rate in steatohepatitis differs depending on the model, and early steatohepatitis could be noninvasively differentiated from hepatic steatosis using CmP in MRI. Since the change in direction of the reduction rate in steatohepatitis in clinical studies could be predicted by confirming the reduction rate in preclinical studies, the present method, which can be used consistently in clinical and preclinical studies, warrants consideration as a candidate monitoring method for differentiating between early drug-induced steatohepatitis and hepatic steatosis in drug development.

Background and Aim Methods Results Conclusion We aimed to investigate the effect of metabolic dysfunction‐associated steatotic liver disease (MASLD) on three‐dose BNT162b2 immunogenicity to the omicron variant.Adult recipients of three doses of BNT162b2 were prospectively recruited between May and December 2021. The serology of the neutralizing antibody by live virus microneutralization (vMN) to the omicron variant was measured at baseline, day 180, and day 360 after the first dose. The primary outcome was seroconversion (vMN titer ≥ 10) at day 360. Exposure of interest was MASLD, defined as hepatic steatosis (controlled attenuation parameter ≥ 248 dB/m on transient elastography) plus at least one of five cardiometabolic risk factors. Subjects with prior COVID‐19 were excluded. A multivariable logistic regression model was used to derive the adjusted odds ratio of seroconversion with MASLD by adjusting for age, sex, antibiotic use, and proton pump inhibitor use.One hundred forty‐eight BNT162b2 recipients (male: 48 [32.4%]; median age: 51.0 years [interquartile range, IQR: 44.5–57.3]) were recruited. The median time from the first dose to the third dose was 8.5 months (IQR: 7.9–8.9). MASLD subjects had a lower seroconversion rate than non‐MASLD ones (89.6% vs 99.0%; P = 0.007). MASLD was the only independent risk factor for seroconversion (adjusted odds ratio: 0.051, 95% confidence interval: 0.002–0.440). Subgroup analysis of immunogenicity at 4 months after the third dose shows significantly lower vMN titer (13.06 [IQR: 7.69–22.20] vs 33.49 [IQR: 24.05–46.53]; P = 0.004) and seroconversion rate (76.9% vs 97.4%; P = 0.016) in MASLD than non‐MASLD subjects, but not within 4 months from the third dose (vMN titer: 46.87 [IQR: 33.12–66.02] vs 41.86 [IQR: 34.47–50.91], P = 0.240; seroconversion rate: 94.3% vs 100%, P = 0.131).Metabolic dysfunction‐associated steatotic liver disease was a risk factor for poorer immunogenicity to the omicron variant, with a more pronounced waning effect compared among three‐dose BNT162b2 recipients. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effects of the typical Mediterranean diet (TMD), low-carbohydrate Mediterranean diet (LCMD), and low-fat Mediterranean diet (LFMD) on biochemical findings, fatty liver index (FLI), anthropometric measurements, and body composition in individuals with obesity with non-alcoholic fatty liver disease (NAFLD) and insulin resistance. This study included 63 participants with obesity with insulin resistance diagnosed with NAFLD by ultrasonography to investigate the effects of an 8-week energy-restricted TMD, LCMD, and LFMD on biochemical findings, FLI, fibrosis-4 index (FIB-4), anthropometric measurements, and body composition. Patients were randomized into three groups and were interviewed face-to-face every week. According to the food consumption records (baseline end), the difference in the amount of sucrose and total fat consumed in the TMD group; the difference in energy intake from sucrose, monounsaturated fatty acids, and oleic acid in the LCMD group; and the difference in energy intake from fiber, sucrose, monounsaturated and polyunsaturated fatty acids, and cholesterol in the LFMD group showed significant correlations with liver enzymes and FLI (p < 0.05). In conclusion, although it has a different macronutrient composition, the Mediterranean diet may positively affect biochemical parameters and FLI in individuals with NAFLD, albeit in different ways. [ABSTRACT FROM AUTHOR]

Constitutive androstane receptor (CAR, Nr1i3), a liver nuclear receptor and xenobiotic sensor, induces drug, steroid, and lipid metabolizing enzymes, stimulates liver hypertrophy and hyperplasia, and ultimately, hepatocellular carcinogenesis. The mechanisms linking early CAR responses to later disease development are poorly understood. Here we show that exposure of CD-1 mice to TCPOBOP (1,4-bis[2-(3,5-dichloropyridyloxy)]benzene), a halogenated xenochemical and selective CAR agonist ligand, induces pericentral steatosis marked by hepatic accumulation of cholesterol and neutral lipid, and elevated circulating alanine aminotransferase, indicating hepatocyte damage. TCPOBOP-induced steatosis was weaker in the pericentral region but stronger in the periportal region in females compared with males. Early (1 day) TCPOBOP transcriptional responses were enriched for CAR-bound primary response genes, and for lipogenesis and xenobiotic metabolism and oxidative stress protection pathways; late (2 weeks) TCPOBOP responses included many CAR binding-independent secondary response genes, with enrichment for macrophage activation, immune response, and cytokine and reactive oxygen species production. Late upstream regulators specific to TCPOBOP-exposed male liver were linked to proinflammatory responses and hepatocellular carcinoma progression. TCPOBOP administered weekly to male mice using a high corn oil vehicle induced carbohydrate-responsive transcription factor (MLXIPL)-regulated target genes, dysregulated mitochondrial respiratory and translation regulatory pathways, and induced more advanced liver pathology. Overall, TCPOBOP exposure recapitulates histological and gene expression changes characteristic of emerging steatotic liver disease, including secondary gene responses in liver nonparenchymal cells indicative of transition to a more advanced disease state. Upstream regulators of both the early and late TCPOBOP response genes include novel biomarkers for foreign chemical-induced metabolic dysfunction-associated steatotic liver disease. [ABSTRACT FROM AUTHOR]

Background: Nonalcoholic fatty liver disease (NAFLD) constitutes an independent risk factor for the development of coronary heart disease. Low-grade inflammation has been shown to play an important role in the development of atherosclerosis and NAFLD. Free fatty acid receptor 4 (FFAR4/GPR120), which is involved in damping inflammatory reactions, may represent a promising target for the treatment of inflammatory diseases. Our objective was to evaluate the effect of TUG-891, the synthetic agonist of FFAR4/GPR120, on fatty liver in vivo. Methods: The effect of TUG-891 on fatty liver was investigated in apoE−/− mice fed a high-fat diet (HFD), using microscopic, biochemical, molecular, and proteomic methods. Results: Treatment with TUG-891 inhibited the progression of liver steatosis in apoE−/− mice, as evidenced by histological analysis, and reduced the accumulation of TG in the liver. This action was associated with a decrease in plasma AST levels. TUG-891 decreased the expression of liver genes and proteins involved in de novo lipogenesis (Srebp-1c, Fasn and Scd1) and decreased the expression of genes related to oxidation and uptake (Acox1, Ehhadh, Cd36, Fabp1). Furthermore, TUG-891 modified the levels of selected factors related to glucose metabolism (decreased Glut2, Pdk4 and Pklr, and increased G6pdx). Conclusion: Pharmacological stimulation of FFAR4 may represent a promising lead in the search for drugs that inhibit NAFLD. [ABSTRACT FROM AUTHOR]

Introduction: Metabolic dysfunction-associated steatotic liver disease (MASLD) and type 2 diabetes mellitus (DM) are the most prevalent metabolic disorders globally. The numbers affected in both disorders are also rapidly increasing with alarming trends in children and young adults. Areas covered: Insulin resistance (IR) and the subsequent metabolic dysregulation are the fundamental pathogenesis pathways of the prevalent metabolic disorders. The interaction and impacts are bidirectional between MASLD and DM in terms of disease mechanisms, disease course, risks, and prognosis. There's a pressing issue for highlighting the links between MASLD and DM for both care specialists and primary care providers. The review collected the scientific evidence addressing the mutual interactions between the two disorders. The strategies for surveillance, risk stratification, and management are discussed in a practical manner. It also provides individualized viewpoints of patient care in hepatology and diabetology. Expert opinion: Both MASLD and DM shared similar disease mechanisms, and affected the disease development and progression in a bidirectional manner. The high prevalence and the cross-link between the two disorders raise clinical issues from awareness, screening, risk stratification, optimal referral, to appropriate management for primary care providers. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: The role of insulin resistance in hepatic fibrosis in Metabolic dysfunction‐Associated SteatoHepatitis (MASH) remains unclear. Carcinoembryonic Antigen‐related Cell Adhesion Molecule1 protein (CEACAM1) promotes insulin clearance to maintain insulin sensitivity and repress de novo lipogenesis, as bolstered by the development of insulin resistance and steatohepatitis in AlbuminCre + Cc1fl/fl mice with liver‐specific mouse gene encoding CEACAM1 protein (Ceacam1) deletion. We herein investigated whether these mice also developed hepatic fibrosis and whether hepatic CEACAM1 is reduced in patients with MASH at different fibrosis stages. Methods: AlbuminCre + Cc1fl/fl mice were fed a regular or a high‐fat diet before their insulin metabolism and action were assessed during IPGTT, and their livers excised for histochemical, immunohistochemical and Western blot analysis. Sirius red staining was used to assess fibrosis, and media transfer was employed to examine whether mutant hepatocytes activated hepatic stellate cells (HSCs). Hepatic CEACAM1 protein levels in patients with varying disease stages were assessed by ELISA. Results: Hepatocytic deletion of Ceacam1 caused hyperinsulinemia‐driven insulin resistance emanating from reduced hepatic insulin clearance. AlbuminCre + Cc1fl/fl livers showed inflammation, fibrosis and hepatic injury, with more advanced bridging and chicken‐wire hepatic fibrosis under high‐fat conditions. Media transferred from hepatocytes isolated from mutant mice activated control HSCs, likely owing to their elevated endothelin1 content. Interestingly, hepatic CEACAM1 levels were lower in the livers of patients with MASH and declined gradually with advanced fibrosis stage. Conclusions: Hepatic CEACAM1 levels declined with progression of MASH in humans. The phenotype of AlbuminCre + Cc1fl/fl mice assigned a key role to CEACAM1 loss from hepatocytes in hepatic fibrosis independently of other liver cells. [ABSTRACT FROM AUTHOR]

Steatotic liver disease (SLD) is a worldwide public health problem, causing considerable morbidity and mortality. Patients with SLD are at increased risk for major adverse cardiovascular (CV) events, type 2 diabetes mellitus and chronic kidney disease. Conversely, patients with cardiometabolic conditions have a high prevalence of SLD. In addition to epidemiological evidence linking many of these conditions, there is evidence of shared pathophysiological processes. In December 2022, a unique multi‐stakeholder, multi‐specialty meeting, called MOSAIC (Metabolic multi Organ Science Accelerating Innovation in Clinical Trials) was convened to foster collaboration across metabolic, hepatology, nephrology and CV disorders. One of the goals of the meeting was to consider approaches to drug development that would speed regulatory approval of treatments for multiple disorders by combining liver and cardiorenal endpoints within a single study. Non‐invasive tests, including biomarkers and imaging, are needed in hepatic and cardiorenal trials. They can be used as trial endpoints, to enrich trial populations, to diagnose and risk stratify patients and to assess treatment efficacy and safety. Although they are used in proof of concept and phase 2 trials, they are often not acceptable for regulatory approval of therapies. The challenge is defining the optimal combination of biomarkers, imaging and morbidity/mortality outcomes and ensuring that they are included in future trials while minimizing the burden on patients, trialists and trial sponsors. This paper provides an overview of some of the wide array of CV, liver and kidney measurements that were discussed at the MOSAIC meeting. [ABSTRACT FROM AUTHOR]

The prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD), a leading cause of chronic liver disease, has increased worldwide along with the epidemics of obesity and related dysmetabolic conditions characterized by impaired glucose metabolism and insulin signaling, such as type 2 diabetes mellitus (T2D). MASLD can be defined as an excessive accumulation of lipid droplets in hepatocytes that occurs when the hepatic lipid metabolism is totally surpassed. This metabolic lipid inflexibility constitutes a central node in the pathogenesis of MASLD and is frequently linked to the overproduction of lipotoxic species, increased cellular stress, and mitochondrial dysfunction. A compelling body of evidence suggests that the accumulation of lipid species derived from sphingolipid metabolism, such as ceramides, contributes significantly to the structural and functional tissue damage observed in more severe grades of MASLD by triggering inflammatory and fibrogenic mechanisms. In this context, MASLD can further progress to metabolic dysfunction-associated steatohepatitis (MASH), which represents the advanced form of MASLD, and hepatic fibrosis. In this review, we discuss the role of sphingolipid species as drivers of MASH and the mechanisms involved in the disease. In addition, given the absence of approved therapies and the limited options for treating MASH, we discuss the feasibility of therapeutic strategies to protect against MASH and other severe manifestations by modulating sphingolipid metabolism. [ABSTRACT FROM AUTHOR]

Introduction: The therapeutic landscape of Metabolic dysfunction-Associated Steatotic Liver Disease (MASLD) is rapidly evolving with the FDA approval of resmetirom, the first authorized molecule to treat metabolic dysfunction-associated steatohepatitis. Clinical trials are investigating other promising molecules. However, this focus on pharmacotherapy may overshadow lifestyle interventions, which remain the cornerstone of MASLD management. A significant percentage of patients with MASLD struggle with an underlying eating disorder, often a precursor to obesity. The obesity pandemic, exacerbated by the increasing prevalence of binge eating, underscores the need for a psychological approach to address their common roots. Areas covered: We reviewed the current evidence on behavioral interventions for MASLD. Interventions such as self-monitoring, goal setting, and frequent counseling, have proven effective in achieving at least 5% weight loss. Cognitive behavioral therapy is the first-line treatment for eating disorders and has shown efficacy in treating binge eating and obesity. Further research is needed to establish the optimal behavioral therapy for MASLD, focusing on enhancing compliance and achieving sustained weight loss through diet and physical exercise. Expert opinion: The treatment of MASLD should not rely solely on pharmacotherapy targeting a single-organ manifestation. Instead, we must consider behavioral interventions, emphasizing the pivotal role of a holistic approach to this multifaceted disorder. [ABSTRACT FROM AUTHOR]

The role of ferroptosis in steatohepatitis development is largely unknown. We investigated (1) whether hepatocyte ferroptosis occurs in a gene-modified steatohepatitis model without modifying dietary components, (2) whether ferroptosis occurs at an early stage of steatohepatitis, and (3) whether apomorphine, recently reported as a ferroptosis inhibitor, can ameliorate steatohepatitis. Hepatocyte-specific PTEN KO mice were used. Huh 7 and primary cultured hepatocytes isolated from the mice were used in this study. The number of dead cells increased in 10-week-old PTEN KO mice. This cell death was suppressed by the administration of ferroptosis inhibitor ferrostatin-1 for 2 weeks. Apomorphine also ameliorated the severity of steatohepatitis. Treatment with ferroptosis inhibitors, including apomorphine, decreases the level of lipid peroxidase. Apomorphine suppressed cell death induced by RSL-3 (a ferroptosis inducer), which was not suppressed by apoptosis or necroptosis inhibitors. Apomorphine showed a radical trapping capacity with much more potent activity than ferrostatin-1 and Trolox, a soluble form of vitamin E. In addition, apomorphine activated nrf2 and its downstream genes, including HO-1 and xCT. In conclusion, ferroptosis occurs in steatohepatitis from an early stage in PTEN KO mice. In addition, apomorphine ameliorates the severity of steatohepatitis by inhibiting ferroptosis. [ABSTRACT FROM AUTHOR]

Context Metabolic dysfunction–associated steatotic liver disease (MASLD) is characterized by the intracellular lipid accumulation in hepatocytes. Excess caloric intake and high-fat diets are considered to significantly contribute to MASLD development. Objective To evaluate the hepatic and serum fatty acid (FA) composition in patients with different stages of MASLD, and their relationship with FA dietary intake and MASLD-related risk factors. Methods This was a case–control study in patients with obesity undergoing bariatric surgery at a university hospital between January 2020 and December 2021. Participants were distributed in 3 groups: no MASLD (n = 26), steatotic liver disease (n = 33), and metabolic dysfunction–associated steatohepatitis (n = 32). Hepatic and serum FA levels were determined by gas chromatography-mass spectrometry. Nutritional status was evaluated using validated food frequency questionnaires. The hepatic expression of genes involved in FA metabolism was analyzed by reverse transcription quantitative polymerase chain reaction. Results The hepatic, but not serum, FA profiles were significantly altered in patients with MASLD compared with those without MASLD. No differences were observed in FA intake between the groups. Levels of C16:0, C18:1, and the C18:1/C18:0 ratio were higher, while C18:0 levels and C18:0/C16:0 ratio were lower in patients with MASLD, being significantly different between the 3 groups. Hepatic FA levels and ratios correlated with histopathological diagnosis and other MASLD-related parameters. The expression of genes involved in the FA metabolism was upregulated in patients with MASLD. Conclusion Alterations in hepatic FA levels in MASLD patients were due to enhancement of de novo lipogenesis in the liver. [ABSTRACT FROM AUTHOR]

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. Conclusion: 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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Ectopic/accessory liver tissue is a rare developmental anomaly thought to be due to abnormal development of the liver during embryogenesis. Most patients with ectopic liver tissue are asymptomatic, and the condition is usually discovered incidentally during intraabdominal surgery or autopsy. In rare symptomatic cases, patients' presentations can range from mild liver function test abnormalities to severe abdominal pain or discomfort secondary to torsion and ischemia. Here, we report 2 patients with ectopic liver tissue identified incidentally during cholecystectomy: one with histologic manifestations of sickle cell congestion and the other with steatohepatitis. A possible relationship between ectopic liver tissue and gallbladder and biliary diseases, such as cholecystitis, has been proposed. To the best of our knowledge, ectopic liver tissue with sickle cell congestion has not been reported previously. [ABSTRACT FROM AUTHOR]

Aim: 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. Methods and Results: 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). Conclusion: The TM6SF2 minor allele may contribute to steatohepatitis development after pancreaticoduodenectomy. [ABSTRACT FROM AUTHOR]

Lifestyle modification is the standard of care for nonalcoholic fatty liver disease (NAFLD) patients. We aimed to investigate the efficacy of a short‐term lifestyle modification program in the disease course of Taiwanese nonalcoholic steatohepatitis (NASH) patients with paired biopsies. All patients received a 6‐month, strict multidisciplinary program of lifestyle modifications led by physicians, dieticians, and nursing staff. The histopathological and clinical features were assessed. The endpoints were normalization of transaminase levels, metabolic parameters, a decrease in the NAFLD activity score (NAS) ≥1, and a decrease in the fibrosis stage ≥1. We also aimed to elucidate the predictors associated with disease progression. A total of 37 patients with biopsy‐proven NASH were enrolled. The normalization of transaminase levels increased from 0% to 13.5%. There were also significantly increased proportions of patients with normal total cholesterol, triglyceride, and hemoglobin A1c levels. Fifteen (40.5%) patients had an increased NAS ≥1, whereas 10 (27.0%) patients had NAS regression. Twelve (32.4%) patients had increased fibrosis ≥1 stage. Only 2 (5.4%) patients experienced fibrosis regression. A high fasting plasma glucose (FPG) level was associated with NAS progression. Older age and higher transaminase and FPG levels were factors associated with fibrosis progression. Seven (18.9%) patients achieved a body weight reduction >3%, and 4 (57.1%) of them experienced NAS regression. No significant effect of weight reduction on the progression of fibrosis was observed. The short‐term lifestyle modification program significantly decreased liver enzymes and metabolic parameters in NASH patients. A more precise or intensive program may be needed for fibrosis improvement. [ABSTRACT FROM AUTHOR]

Background and Objectives: It is well known that lipid abnormalities exist in the context of non-alcoholic fatty liver disease (NAFLD). The association between lipoprotein(a) [Lp(a)] levels and NAFLD is poorly understood. The main objective of the present study was to assess the association between Lp(a) levels and NAFLD. Methods: This systematic review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (PROSPERO CRD42023392526). A literature search was performed to detect studies that evaluated the association between Lp(a) levels, NAFLD and steatohepatitis (NASH). Results: Ten observational studies, including 40,045 patients, were identified and considered eligible for this systematic review. There were 9266 subjects in the NAFLD groups and 30,779 individuals in the respective control groups. Five studies evaluated patients with NAFLD (hepatic steatosis was associated with lower Lp(a) levels in four studies, while the remaining showed opposite results). Two studies evaluating NASH patients showed that Lp(a) levels were not different compared to controls. However, the increment of Lp(a) levels was correlated with liver fibrosis in one of them. In addition, one study analyzed simultaneously patients with NAFLD and NASH, showing a neutral result in NAFLD patients and a positive relationship in NASH patients. Two studies that included patients with the new definition of metabolic-associated fatty liver disease (MAFLD) also showed neutral results. Conclusion: Although there could be an association between Lp(a) levels and hepatic steatosis, the results of the studies published to date are contradictory and not definitive. [ABSTRACT FROM AUTHOR]

Background & aimsHepatocellular carcinoma (HCC), a leading cause of cancer-related death, is associated with viral hepatitis, non-alcoholic steatohepatitis (NASH), and alcohol-related steatohepatitis, all of which trigger endoplasmic reticulum (ER) stress, hepatocyte death, inflammation, and compensatory proliferation. Using ER stress-prone MUP-uPA mice, we established that ER stress and hypernutrition cooperate to cause NASH and HCC, but the contribution of individual stress effectors, such as activating transcription factor 4 (ATF4), to HCC and their underlying mechanisms of action remained unknown.MethodsHepatocyte-specific ATF4-deficient MUP-uPA mice (MUP-uPA/Atf4Δhep) and control MUP-uPA/Atf4F/F mice were fed a high-fat diet to induce NASH-related HCC, and Atf4F/F and Atf4Δhep mice were injected with diethylnitrosamine to model carcinogen-induced HCC. Histological, biochemical, and RNA-sequencing analyses were performed to identify and define the role of ATF4-induced solute carrier family 7a member 11 (SLC7A11) expression in hepatocarcinogenesis. Reconstitution of SLC7A11 in ATF4-deficient primary hepatocytes and mouse livers was used to study its effects on ferroptosis and HCC development.ResultsHepatocyte ATF4 ablation inhibited hepatic steatosis, but increased susceptibility to ferroptosis, resulting in accelerated HCC development. Although ATF4 activates numerous genes, ferroptosis susceptibility and hepatocarcinogenesis were reversed by ectopic expression of a single ATF4 target, Slc7a11, coding for a subunit of the cystine/glutamate antiporter xCT, which is needed for glutathione synthesis. A ferroptosis inhibitor also reduced liver damage and inflammation. ATF4 and SLC7A11 amounts were positively correlated in human HCC and livers of patients with NASH.ConclusionsDespite ATF4 being upregulated in established HCC, it serves an important protective function in normal hepatocytes. By maintaining glutathione production, ATF4 inhibits ferroptosis-dependent inflammatory cell death, which is known to promote compensatory proliferation and hepatocarcinogenesis. Ferroptosis inhibitors or ATF4 activators may also blunt HCC onset.Impact and implicationsLiver cancer or hepatocellular carcinoma (HCC) is associated with multiple aetiologies. Most HCC aetiologies cause hepatocyte stress and death, as well as subsequent inflammation, and compensatory proliferation, thereby accelerating HCCdevelopment. The contribution of individual stress effectors to HCC and their underlying mechanisms of action were heretofore unknown. This study shows that the stress-responsive transcription factor ATF4 blunts liver damage and cancer development by suppressing iron-dependent cell death (ferroptosis). Although ATF4 ablation prevents hepatic steatosis, it also increases susceptibility to ferroptosis, due to decreased expression of the cystine/glutamate antiporter SLC7A11, whose expression in human HCC and NASH correlates with ATF4. These findings reinforce the notion that benign steatosis may be protective and does not increase cancer risk unless accompanied by stress-induced liver damage. These results have important implications for prevention of liver damage and cancer.

Aim: A clinical decision support (CDS) tool for metabolic dysfunction-associated steatohepatitis (MASH) was developed to align health systems with clinical guidelines detailed in the MASH Clinical Care Pathway and improve patients’ proactive self-management of their disease. The tool includes a provider-facing web-based application and a mobile application (app) for patients. This protocol outlines a pilot study that will systematically evaluate the implementation of the tool in real-world clinical practice settings. Materials & methods: This implementation research study will use a simultaneous mixed-methods design and is guided by the Consolidated Framework for Implementation Research. The CDS tool for MASH will be piloted for ≥3 months at multiple US-based sites with eligible gastroenterologists and hepatologists (n = 5–10 per site) and their patients (n = 50–100 per site) with MASH or suspected MASH. Each pilot site may choose one or all focus areas within the tool (i.e., risk stratification, screening and referral, or patient care management), based on on-site capabilities. Prior to and at the end of the pilot period, providers and patients will complete quantitative surveys and partake in semi-structured interviews. Outcomes will include understanding the feasibility of implementing the tool in real-world clinical settings, its effectiveness in increasing patient screenings and risk stratification for MASH, its ability to improve provider and patient knowledge of MASH, barriers to adoption of the tool and the tool’s capacity to enhance patient engagement and satisfactionwith their care. Conclusion: Findings will inform the scalable implementation of the tool to ensure patients at risk for MASH are identified early, referred to specialty care when necessary and managed appropriately. Successful integration of the patient app can contribute to better health outcomes for patients by facilitating their active participation in the management of their condition.

Background & aimsType 2 diabetes (T2D) is a growing problem in children. Children with NAFLD are at potentially high risk for developing T2D; however, the incidence of T2D in this population is unknown. This study aimed to determine the incidence of T2D in children with NAFLD and identify associated risk factors.MethodsChildren with NAFLD enrolled in the Nonalcoholic Steatohepatitis Clinical Research Network were followed longitudinally. Incidence of T2D was determined by using clinical history and fasting laboratory values. Cumulative incidence curves were developed for time to T2D. A Cox regression multivariable model was constructed using best subsets Akaike's Information Criteria selection.ResultsThis study included 892 children with NAFLD and with a mean age of 12.8 years (2.7) followed for 3.8 years (2.3) with a total 3234 person-years at risk. The incidence rate of T2D was 3000 new cases per 100,000 person-years at risk. At baseline, 63 children had T2D, and during follow-up, an additional 97 children developed incident T2D, resulting in a period prevalence of 16.8%. Incident T2D was significantly higher in females versus males (hazard ratio [HR], 1.8 [1.0-2.8]), associated with BMI z-score (HR, 1.8 [1.0-3.0]), and more severe liver histology including steatosis grade (HR, 1.3 [1.0-1.7]), and fibrosis stage (HR, 1.3 [1.0-1.5]).ConclusionsChildren with NAFLD are at high risk for existing and incident T2D. In addition to known risk factors for T2D (female and BMI z-score), severity of liver histology at the time of NAFLD diagnosis was independently associated with T2D development. Targeted strategies to prevent T2D in children with NAFLD are needed.

Background & aimsDespite recent progress, non-invasive tests for the diagnostic assessment and monitoring of non-alcoholic fatty liver disease (NAFLD) remain an unmet need. Herein, we aimed to identify diagnostic signatures of the key histological features of NAFLD.MethodsUsing modified-aptamer proteomics, we assayed 5,220 proteins in each of 2,852 single serum samples from 636 individuals with histologically confirmed NAFLD. We developed and validated dichotomized protein-phenotype models to identify clinically relevant severities of steatosis (grade 0 vs. 1-3), hepatocellular ballooning (0 vs. 1 or 2), lobular inflammation (0-1 vs. 2-3) and fibrosis (stages 0-1 vs. 2-4).ResultsThe AUCs of the four protein models, based on 37 analytes (18 not previously linked to NAFLD), for the diagnosis of their respective components (at a clinically relevant severity) in training/paired validation sets were: fibrosis (AUC 0.92/0.85); steatosis (AUC 0.95/0.79), inflammation (AUC 0.83/0.72), and ballooning (AUC 0.87/0.83). An additional outcome, at-risk NASH, defined as steatohepatitis with NAFLD activity score ≥4 (with a score of at least 1 for each of its components) and fibrosis stage ≥2, was predicted by multiplying the outputs of each individual component model (AUC 0.93/0.85). We further evaluated their ability to detect change in histology following treatment with placebo, pioglitazone, vitamin E or obeticholic acid. Component model scores significantly improved in the active therapies vs. placebo, and differential effects of vitamin E, pioglitazone, and obeticholic acid were identified.ConclusionsSerum protein scanning identified signatures corresponding to the key components of liver biopsy in NAFLD. The models developed were sufficiently sensitive to characterize the longitudinal change for three different drug interventions. These data support continued validation of these proteomic models to enable a "liquid biopsy"-based assessment of NAFLD.Clinical trial numberNot applicable.Impact and implicationsAn aptamer-based protein scan of serum proteins was performed to identify diagnostic signatures of the key histological features of non-alcoholic fatty liver disease (NAFLD), for which no approved non-invasive diagnostic tools are currently available. We also identified specific protein signatures related to the presence and severity of NAFLD and its histological components that were also sensitive to change over time. These are fundamental initial steps in establishing a serum proteome-based diagnostic signature of NASH and provide the rationale for using these signatures to test treatment response and to identify several novel targets for evaluation in the pathogenesis of NAFLD.

In September 2023, the European Association for the Study of the Liver (EASL) updated the disease nomenclature for non-alcoholic (metabolically associated) fatty liver disease. The goals of the revision were to increase awareness among health care professionals, civil society and patients about the disease, its course, treatment and outcomes; combating stigma; focusing on the initial etiological factor, including the main (cardiometabolic) risk of disease progression; improved diagnosis based on disease biomarkers; positive impact on the potency to search for new drugs; the ability to provide personalized medical care. The terms “non-alcoholic” and “fatty” were considered stigmatizing, and therefore, it was proposed to use the term steatotic liver disease (SLD) as the name of this nosology. The terms non-alcoholic fatty liver disease (NAFLD) or metabolic associated fatty liver disease (MAFLD) have been replaced by the term metabolic dysfunction-associated steatotic liver disease (MASLD). In the case of being combined with an alcohol factor, a diagnosis in which metabolic dysfunction is combined with alcoholic liver disease is referred to as MetALD. The fundamental principle in the diagnosis of MASLD is the presence of at least one of the cardiometabolic risk factors. Alcohol consumption interacts with cardiometabolic risk factors and increases the risk of SLD decompensation. The term nonalcoholic steatohepatitis (NASH), according to the new nomenclature, has been replaced by the term metabolic dysfunction-associated steatohepatitis (MASH). The adoption of the new nomenclature should help to increase awareness about the disease, its course and outcomes, as well as improve the quality of diagnosis and treatment.

Background. Despite active research, drug treatment options for metabolic associated fatty liver disease (MAFLD) are limited, and there are no currently approved drugs for patients with MAFLD. Treatment of patients at risk of developing non-alcoholic steatohepatitis and progressive liver fibrosis (LF) is of particular relevance, since they determine the clinical outcomes of the disease. Aim. To evaluate the clinical efficacy of complex polypeptide drug (CPD), human placenta hydrolyzate, containing low molecular weight regulatory peptides, amino acids, vitamins, macro- and microelements in patients with MAFLD at the LF stage. Materials and methods. A single-center, placebo-controlled pilot study. Patients with MAFLD at LF stage 1≤F≤3 according to METAVIR were included (n=10, of which 8 were women, median age was 55 years old). Patients were randomized into 2 groups: 5 people received CPD therapy for 12 weeks (intravenous infusion of 6 ml 2 times a week); another 5 people initially received placebo x 2 times a week (12 weeks), with transfer to the open phase for CPD therapy in the same regimen. The dynamics laboratory and instrumental data was assessed, as well as determine the presence of fibrosis by non-invasive tests – measurement of liver stiffness by transient elastography and use of serum biomarker (SM) by FibroTest and detection of steatosis with controlled attenuation parameter for transient elastography and SM by SteatoTest. The quality of life of patients was assessed using questionnaire SF-36 and well-being via Visual Analogue Scale. Statistical processing of the material was carried out using the methods of nonparametric analysis, using the Statistica 13.3 software. Results. Patients in the CPD group compared with the baseline data and with the placebo group showed a statistically significant improvement: 1) transaminases (ALT, AST), lipid profile indicators (cholesterol), ferritin; 2) indicators of LF, based on a decrease in liver stiffness by transient elastography and SM of Fibrotest, as well as the degree of steatosis based on controlled attenuation parameter and SM of Steatotest; 3) in well-being and quality of life (according to testing: SF-36 physical, mental well-being and general condition of the VAS). CPD was well tolerated, no side effects were noted. Conclusion. In patients with MAFLD during CPD therapy, a decrease in the level of liver enzymes was noted, as well as in LF and liver steatosis according to noninvasive methods. Randomized controlled trials are required to confirm these findings.

Analogues of the hepatokine fibroblast growth factor 21 (FGF21) are in clinical development for type 2 diabetes and nonalcoholic steatohepatitis (NASH) treatment. Although their glucose-lowering and insulin-sensitizing effects have been largely unraveled, the mechanisms by which they alleviate liver injury have only been scarcely addressed. Here, we aimed to unveil the mechanisms underlying the protective effects of FGF21 on NASH using APOE*3-Leiden.CETP mice, a well-established model for human-like metabolic diseases. Liver-specific FGF21 overexpression was achieved in mice, followed by administration of a high-fat high-cholesterol diet for 23 weeks. FGF21 prevented hepatic lipotoxicity, accompanied by activation of thermogenic tissues and attenuation of adipose tissue inflammation, improvement of hyperglycemia and hypertriglyceridemia, and upregulation of hepatic programs involved in fatty acid oxidation and cholesterol removal. Furthermore, FGF21 inhibited hepatic inflammation, as evidenced by reduced Kupffer cell (KC) activation, diminished monocyte infiltration, and lowered accumulation of monocyte-derived macrophages. Moreover, FGF21 decreased lipid- and scar-associated macrophages, which correlated with less hepatic fibrosis as demonstrated by reduced collagen accumulation. Collectively, hepatic FGF21 overexpression limits hepatic lipotoxicity, inflammation, and fibrogenesis. Mechanistically, FGF21 blocks hepatic lipid influx and accumulation through combined endocrine and autocrine signaling, respectively, which prevents KC activation and lowers the presence of lipid- and scar-associated macrophages to inhibit fibrogenesis.

In recent years, there has been a rapid expansion in our understanding of regulated cell death, leading to the discovery of novel mechanisms that govern diverse cell death pathways. One recently discovered type of cell death is pyroptosis, initially identified in the 1990s as a caspase-1-dependent lytic cell death. However, further investigations have redefined pyroptosis as a regulated cell death that relies on the activation of pore-forming proteins, particularly the gasdermin family. Among the key regulators of pyroptosis is the inflammasome sensor NOD-like receptor 3 (NLRP3), a critical innate immune sensor responsible for regulating the activation of caspase-1 and gasdermin D. A deeper understanding of pyroptosis and its interplay with other forms of regulated cell death is emerging, shedding light on a complex regulatory network controlling pore-forming proteins and cell fate. Cell death processes play a central role in diseases such as metabolic dysfunction-associated steatotic liver disease, metabolic dysfunction-associated steatohepatitis, autoinflammatory disorders, and cancer. Cell death often acts as a starting point in these diseases, making it an appealing target for drug development. Yet, the complete molecular mechanisms are not fully understood, and new discoveries reveal promising novel avenues for therapeutic interventions. In this review, we summarize recent evidence on pathways and proteins controlling pyroptosis and gasdermins. Furthermore, we will address the role of pyroptosis and the gasdermin family in metabolic dysfunction-associated steatotic liver disease and steatohepatitis. Additionally, we highlight new potential therapeutic targets for treating metabolic dysfunction-associated steatohepatitis and other inflammatory-associated diseases.

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]