Metabolic-associated fatty liver disease (MASLD) is not only associated with traditional cardiovascular risk factors such as T2DM and obesity, but it is also an independent risk factor for the development of cardiovascular disease. MASLD has been shown to be independently related to endothelial dysfunction and atherosclerosis. MASLD is characterized by a chronic proinflammatory response that, in turn, may induce a prothrombotic state. Several mechanisms such as endothelial and platelet dysfunction, changes in the coagulation cascade, decreased fibrinolytic activity can contribute to induce the prothrombotic state. Platelets are players and addresses of metabolic dysregulation; obesity and insulin resistance are related to platelet hyperactivation. Furthermore, platelets can exert a direct effect on liver cells, particularly through the release of mediators from granules. Growing data in literature support the use of antiplatelet agent as a treatment for MASLD. The use of antiplatelets drugs seems to have potential clinical implication for the prevention of HCC patients with MASLD, since platelets contribute to fibrosis progression and cancer development. This review aims to summarize the main data on the role of platelets in the pathogenesis of MAFLD and its main complications such as cardiovascular events and the development of liver fibrosis. Furthermore, we will examine the role of antiplatelet therapy not only in the prevention and treatment of cardiovascular events but also as a possible anti-fibrotic and anti-tumor agent.

Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly termed nonalcoholic fatty liver disease (NAFLD), is a widespread global health concern that affects around 25% of the global population. Its influence is expanding, and it is anticipated to overtake alcohol as the leading cause of liver failure and liver-related death worldwide. Unfortunately, there are no approved therapies for MASLD; as such, national and international regulatory health agencies undertook strategies and action plans designed to expedite the development of drugs for treatment of MASLD. A sedentary lifestyle and an unhealthy diet intake are important risk factors. Western countries have a greater estimated prevalence of MASLD partly due to lifestyle habits. Mitochondrial dysfunction is strongly linked to the development of MASLD. Further, it has been speculated that mitophagy, a type of mitochondrial quality control, may be impaired in MASLD. Thyroid hormone (TH) coordinates signals from the nuclear and mitochondrial genomes to control mitochondrial biogenesis and function in hepatocytes. Mitochondria are known TH targets and preclinical and clinical studies suggest that TH, thyroid receptor β (TR-β) analogs, and synthetic analogs specific to liver could be of therapeutic benefit in treating MASLD. In this review, we highlight how mitochondrial dysfunction contributes to development of MASLD, and how understanding the role of TH in improving mitochondrial function paved the way for innovative drug development programs of TH-based therapies targeting MASLD.

Aim: To determine the prevalence of skeletal muscle alterations (SMA) in patients with meta-bolic dysfunction-associated steatotic liver disease (MASLD) and to assess the significance of circulating myokines as potential biomarkers of SMA in patients with MASLD. Material and methods: Measurements of both skeletal muscle strength and skeletal muscle mass parameters, anthropometric and metabolic features as well as serum levels of different myokines were per-formed in a cohort of 62 MASLD patients and then compared according to the stage of liver fi-brosis and hepatosteatosis degree both diagnosed by transitional elastography. Results: No sig-nificant differences were found in skeletal muscle strength and skeletal muscle mass in MASLD patients stratified according to the stage of liver fibrosis. Noteworthy, serum levels of FGF21 were significantly higher in MASLD patients with advanced hepatic fibrosis (F3-F4) than in those with lower stages of hepatic fibrosis (F0-F2) (197.49±198.27 pg/ml vs 95.62±83.67 pg/ml, p=0.049, respectively). MASLD patients with severe hepatosteatosis (S3) had significantly higher serum levels of irisin (1116.87±1161.86 pg/ml) than those with lower grades (S1-S2) (385.21±375.98 pg/ml, p=0.001). Conclusion: SMA were uncommon in our MASLD patients, particularly in those with lower stages of liver fibrosis. An increase in serum FGF21 was detected in patients with a higher stage of fibrosis with possible therapeutic implications in MASLD.

Background: Progression of metabolic dysfunction associated steatotic liver disease (MASLD) to steatohepatitis (MASH) is driven by stress-inducing lipids that promote liver inflammation and fibrosis. MASH can lead to cirrhosis and hepatocellular carcinoma. We showed coordinated defenses regulated by transcription factors, nuclear factor erythroid 2 related factor-1 (Nrf1) and -2 (Nrf2), protect against hepatic lipid stress. Here, we investigated protective effects of hepatocyte Nrf1 and Nrf2 against MASLD-induced liver fibrosis and tumorigenesis. Methods: Using mice fed MASH diet for 24-52 weeks, we examined MASLD in mice with hepatocyte specific Nrf1, Nrf2, or combined deletion, and compared this to control. In a separate study, mice received weekly injections of carbon tetrachloride to induce liver fibrosis. From week 16-24, mice were treated with Nrf2 activating drug bardoxolone, hepatocyte overexpression of human NRF1 (hNRF1), or both, and groups were compared to control. Results: Hepatocyte Nrf2 deficiency had no effect. Hepatocyte Nrf1 and combined deficiency caused MASH but only hepatocyte Nrf1 deficiency in male mice increased tumor number. Bardoxolone reduced liver steatosis, fibrosis, inflammation, and proliferation, and this effect when combined with hNRF1 was greater than bardoxolone alone. Conclusion: Physiologic Nrf1 delays MASLD progression, Nrf2-induction alleviates MASH, and combined enhancement synergistically protects against steatosis.

Myokines are peptides released by the skeletal muscle that exert effects on peripheral tissues, activating metabolic or protective pathways against oxidative stress and inflammation. Many myokines increase their plasma levels after exercise, providing new insights into the role of physical activity in combating sarcopenia and preventing metabolic diseases, such as obesity, diabetes, and metabolic dysfunction associated with steatotic liver disease (MASLD). This review aims to discuss the roles of specific myokines in activating intracellular pathways in the liver to protect against steatosis and lipoperoxidation in MASLD. The progression of liver disease from steatosis to cirrhosis is partially driven by ferroptosis, an iron-dependent form of cell death linked to oxidative stress and lipoperoxidation. Exercise-induced myokines, such as irisin, have been shown to upregulate antioxidant enzymes such as glutathione (GSH) and glutathione peroxidase 4 (GPX4), which are crucial in reducing ferroptosis in hepatic tissues. This review provides a comprehensive perspective on the protective effects of myokines in the liver, particularly against lipid peroxidation and ferroptosis in MASLD, and highlights exercise as a therapeutic strategy to prevent the progression of this liver pathology.

Introduction: Sarcopenia, muscle loss, often coexists with MASLD, a common liver disorder, which is more prevalent in those with sarcopenia. Sarcopenia also increases the risk of liver conditions like steatosis and fibrosis. Studies on sarcopenia in MASLD are common in developed countries, but fewer follow the EWGSOP2 guidelines in Brazil. Aim: to assess sarcopenia prevalence in MASLD patients. Methods: Cross-sectional study conducted at the Gastroen-terology/Hepatology Service of ISCMPA with patients diagnosed with MASLD. The EWGSOP2 criteria were used to evaluate sarcopenia. Categorical data presented as absolute and relative frequency; parametric continuous data ex-pressed as mean±standard deviation; non-parametric continuous data as me-dian and IQR. Gender differences in were analyzed using Fisher's Exact Test or Chi-squared tests, and for continuous variables, T Student tests (parametric) and Mann-Whitney U tests for independent samples (non-parametric). The significance level was set at 5% (p<0.05). Results: The study involved 103 MASLD patients with an average age of 60.39 years, comprising 48 (46.60%) adults and 55 (53.40%) older individuals. Concerning sarcopenia diagnosis, four individuals exhibited decreased muscle strength; two had reduced MME (sarcopenia); and one showed decreased walking speed (severe sarcopenia). Among the participants, 63 (60.6%) were physically active. 35 (62.5%) had mild to moderate steatosis, while 21 (37.5%) had severe steatosis. In terms of EHNA, 13 subjects (24.08%) had moderate to severe EHNA. Regarding fibrosis classi-fication, 68 (72.34%) individuals had undetermined or high probability based on the NAFLD score, with higher prevalence in males (n=23; 88.5%). Fibrosis assessment via liver biopsy revealed 27 (28.72%) in F1 and F2 and 15 (16.96%) in F3 and F4. Stratification of fibrosis into F3 and F4 was more com-mon among men (n=9; 47.4%). Conclusion: Most of the population was physi-cally active. The parameters indicating sarcopenia exceeded the thresholds recommended by EWGSOP2. The prevalence of sarcopenia was low in individuals with MASLD.

A sedentary lifestyle associated with unregulated diets rich in high-calorie foods have contributed to the great prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) latterly, with up to 60% in high-risk population and 25% in the general population. The absence of specific pharmacological strategies for this syndrome represents one of the major problems in the management of MASLD patients. Lifestyle interventions and adherence to a healthy diet are the main cornerstones of current therapies. The identification of nutraceuticals useful in the treatment of MASLD appears to be one of the most promising strategies for the development of new effective and safe treatments for this disease. The onion, one of the most widely studied foods in the field of nutraceuticals, serves as an inexhaustible reservoir of potent compounds with various beneficial effects. The following preliminary study analyses, mediating in silico studies, the iteration of a library of typical onion compounds with 3-hydroxy-3-methylglutaryl-coenzyme A reductase, Liver receptors X α and β as well as Peroxisome proliferator-activated receptors α and γ. In this study fort the first time promising smart molecules from the onion that could have a beneficial action in MASLD patients were identified.

The peptide hormone kisspeptin attenuates liver steatosis, metabolic dysfunction-associated stea-tohepatitis (MASH) and fibrosis in mouse models, by signaling via the kisspeptin 1 receptor (KISS1R). However, whether kisspeptin impacts fibrogenesis in the human liver is not known. We investigated the impact of a potent kisspeptin analog (KPA) on fibrogenesis using human precision cut liver slices (hPCLS) from fibrotic livers from male patients, in human hepatic stellate cells (HSCs), LX-2 and in primary mouse HSCs. In hPCLS, 48 h and 72 h of KPA (3 nM, 100 nM) treatment decreased collagen secretion, and lowered expression of fibrogenic and inflammatory markers. Immunohistochemical studies revealed that KISS1R is expressed and localized to HSCs in MASH/fibrotic livers. In HSCs, KPA treatment reduced transforming growth factor beta (TGFb)-induced expression of fibrogenic and inflammatory markers, in addition to decreasing TGFb induced collagen secretion, cell migration, proliferation and colony formation. Mechanistically, KISS1R signaling downregulated TGFb signaling by decreasing SMAD2/3 phosphorylation, via activation of protein-phosphatases PP2A, that dehosphorylates SMAD 2/3. This study revealed for the first time that kisspeptin reverses human hepatic fibrogenesis thus identifying it as a new therapeutic target to treat hepatic fibrosis.

Maternal obesity and/or Western diet (WD) is associated with increased risk of metabolic dysfunction-associated steatotic liver disease (MASLD) in offspring, driven, in part, by dysregulation of the early life microbiome. Here, using a mouse model of WD-induced maternal obesity, we demonstrate that exposure to a disordered microbiome from WD-fed dams suppressed circulating levels of endogenous ligands of the aryl hydrocarbon receptor (AHR; indole, indole-3-acetate) and TMAO (a product of AHR-mediated transcription), as well as hepatic expression of Il10 (an AHR target), in offspring at 3 weeks of age. This signature was recapitulated by fecal microbial transfer from WD-fed pregnant dams to chow-fed germ-free (GF) lactating dams following parturition, and was associated with reduced abundance of Lactobacillus in GF offspring. Further, expression of Il10 was downregulated in liver myeloid cells and in LPS-stimulated bone marrow-derived macrophages (BMDM) in adult offspring, suggestive of a hypo-responsive, or tolerant, innate immune response. BMDMs from adult mice lacking AHR in macrophages exhibited a similar tolerogenic response, including diminished expression of Il10. Overall, our study shows that exposure to maternal WD alters microbial metabolites in the offspring that affect AHR signaling, potentially contributing to innate immune hypo-responsiveness and progression of MASLD, and highlights the impact of early life gut dysbiosis on offspring metabolism. Further investigations are warranted to elucidate the complex interplay between maternal diet, gut microbial function, and development of neonatal innate immune tolerance and potential therapeutic interventions targeting these pathways.

Ferroptosis, a form of regulated cell death characterized by lipid peroxidation and iron accumulation, has been implicated in the progression of metabolic dysfunction-associated steatohepatitis (MASH) in obesity. This study investigated the role of ferroptosis in the development of hepatic steatosis and MASH in obese mice and assessed the therapeutic potential of ferrostatin-1, a ferroptosis inhibitor. C57BL/6J wild-type mice (n = 8) and ob/ob (n = 16) were maintained on a standard chow diet. Mice were divided into three groups that included C57BL/6 (n = 8), ob/ob (n = 8), and ob/ob + ferrostatin-1 (FER) (n = 8), with the latter group receiving an intraperitoneal injection of 5 μM/kg ferrostatin three times per week for eight weeks. Following treatment, serum and tissue samples were collected for analysis. Significant hepatic steatosis and increased lipogenesis markers were observed in ob/ob mice, and this was normalized in the ob/ob + FER group treated with ferrostatin-1. Elevated oxidative stress was indicated by increased reactive oxygen species (ROS) and Malondialdehyde (MDA) levels in the ob/ob group, while glutathione peroxidase 4 (GPX4) activity was significantly reduced. Ferrostatin-1 treatment decreases MDA levels and restores GPX4 activity. Additionally, ferrostatin mitigates iron overload and promotes macrophage polarization from M1 to M2, thereby reducing liver inflammation and fibrosis. Ferrostatin treatment reversed mitochondrial dysfunction in ob/ob mice Our findings revealed that ferroptosis plays a significant role in the progression of obesity to hepatic steatosis and MASH. Inhibiting ferroptosis using ferrostatin-1 effectively improves liver histology, reduces oxidative stress, normalizes lipogenesis, and modulates macrophage polarization. This study highlights the potential of targeting ferroptosis as a therapeutic strategy for obesity-related liver diseases, warranting further investigation in clinical settings.

Metabolic dysfunction-associated steatotic liver disease (MASLD) encompasses metabolic dysfunction-associated fatty liver (MASL) and metabolic dysfunction-associated steatohepatitis (MASH), with MASH posing a risk of progression to cirrhosis and hepatocellular carcinoma (HCC). The global prevalence of MASLD is estimated at approximately a quarter of the population, with significant healthcare costs and implications for liver transplantation. The pathogenesis of MASLD involves intrahepatic liver cells, extrahepatic components, and immunological aspects, particularly the involvement of macrophages. Hepatic macrophages are a crucial cellular component of the liver and play vital roles in liver function, contributing significantly to tissue homeostasis and swift responses during pathophysiological conditions. Recent advancements in technology have revealed the remarkable heterogeneity and plasticity of hepatic macrophage populations and their activation states in MASLD, challenging traditional classification methods like the M1/M2 paradigm and highlighting the coexistence of harmful and beneficial macrophage phenotypes that are dynamically regulated during MASLD progression. This complexity underscores the importance of considering macrophage heterogeneity in therapeutic targeting strategies, including their distinct ontogeny and functional phenotypes. This review provides an overview of macrophage involvement in MASLD progression, combining traditional paradigms with recent insights from single-cell analysis and spatial dynamics. It also addresses unresolved questions and potential therapeutic targets in this area.