Search Results (19)

Fibroblast growth factor 21 (FGF21) and ketone bodies are markers of metabolic dysregulation, independently associated with metabolic-dysfunction-associated steatotic liver disease (MASLD) and mortality. We studied their interaction with MASLD and all-cause mortality in 6025 participants from the Prevention of Renal and Vascular End-stage Disease (PREVEND) cohort. Plasma FGF21 (immunoassay) and ketone body concentrations (nuclear magnetic resonance spectroscopy) were measured at baseline. A Fatty Liver Index ≥60 was used as a proxy of MASLD. Logistic regression assessed associations with MASLD, and Cox models evaluated all-cause mortality over a median follow-up of 10.3 years. FGF21 and ketone bodies were not correlated (r = 0.02, p = 0.06), but FGF21 (OR: 1.93 [1.81–2.05], p < 0.001) and ketone bodies (OR: 1.29 [1.19–2.05], p < 0.001) were independent of each other associated with MASLD, with a positive interaction (p = 0.004). Higher FGF21 (HR: 1.24, 95% CI: 1.16–1.32, p < 0.001) and ketone bodies (HR: 1.46, 95% CI: 1.34–1.59, p < 0.001) were associated with mortality, as well as with a positive interaction (p = 0.038). After adjustment for potential confounders, only ketone bodies remained independently associated, while the association of FGF21 became dependent on ketone body levels (interaction p = 0.005). These biomarkers may serve as integrated metabolic stress markers, improving risk stratification for MASLD and adverse outcomes. Full article

Background: Liver cirrhosis is often accompanied by metabolic dysfunction. Circulating β-hydroxybutyrate (BHB), the most abundant ketone body, is an emerging metabolic biomarker of mitochondrial dysfunction. Methods: In this prospective observational study, we evaluated plasma BHB concentrations in patients with cirrhosis compared to the general population and investigated their association with all-cause mortality in cirrhosis. Plasma BHB, measured by nuclear magnetic resonance spectroscopy, was compared between 125 patients with cirrhosis on the waiting list for liver transplantation (TransplantLines cohort study; NCT03272841) with 125 propensity-score-matched participants from the population-dwelling PREVEND cohort. Associations of BHB with all-cause mortality were established by tertile-based log-rank tests and Cox regression analyses. A generalized additive model was fitted to assess a potential non-linear association between BHB and mortality. Results: Patients with cirrhosis had lower plasma BHB concentrations than matched PREVEND participants (111.5 µmol/L vs. 138.4 µmol/L, p = 0.02). During 133 (interquartile range 42–375) days of follow up, 27 patients died. All-cause mortality was lowest in the middle BHB tertile and highest in the upper BHB tertile (p < 0.001 by log-rank test). A non-linear, J-shaped association between BHB levels and mortality risk was found with a higher risk of death with the highest and lowest BHB levels. In Cox regression analyses, adjusted for age, sex, MELD score, diabetes, and HDL cholesterol, mortality was highest in the highest BHB tertile (T3 vs. T2 HR: 7.6, 95% CI: 2.3–25.6, p < 0.001). Mortality also tended to be higher in the lowest vs. the middle (T1 vs. T2 HR: 3.5, 95% CI: 0.9–11.7, p = 0.06). Sensitivity analyses, excluding diabetic patients and those with metabolic dysfunction-associated steatotic liver disease, confirmed the robustness of these findings. Conclusion: BHB levels exhibit a J-shaped association with the risk of death in patients with liver cirrhosis. The highest circulating BHB levels are independently associated with increased mortality risk, potentially reflecting underlying metabolic dysregulation. Future studies are necessary to validate the utility of BHB as a prognostic target in cirrhosis. Full article

Metabolic dysfunction associated with steatotic liver disease (MASLD) is the result of disturbed lipid metabolism. In MASLD, the accumulation of free fatty acids (FFAs) in hepatocytes causes lipotoxicity mediated by oxidative stress. Coffee compounds are known for their beneficial effects in MASLD; however, the mechanisms still need to be further explored. The aim of this study was to elucidate the protective mechanisms of coffee compounds against palmitate-induced lipotoxicity in primary hepatocytes. Methods: Primary hepatocytes were isolated from male Wistar rats and treated with palmitate (1 mmol/L) in combination with caffeine (CF: 1 mmol/L) or chlorogenic acid (CGA: 5 µmol/L). Mitochondrial ROS production, palmitate-induced necrosis, antioxidant response, ER stress markers and lipid droplet (LD) formation were assessed. Monoacylglycerols 2-SG (2-Stearolylglycerol), 2-OG (2-Oleoylglycerol) and SCD-1 (Stearoyl-CoA Desaturase 1) inhibitors were used to modulate LD formation. LD formation in steatotic Zucker rat hepatocytes was also investigated. Results: CF and CGA prevented palmitate-induced cell death and reduced ROS production. CF and CGA induced the antioxidant response, especially HO-1 expression, but had no significant effect on ER stress markers. CF and CGA increased LD formation in palmitate-treated cells. This effect was significantly reduced by 2-SG and SCD-1 inhibitors but enhanced by 2-OG. Lipid droplets were associated with lower palmitate toxicity and reduced ROS production. Conclusions: CF and CGA protect hepatocytes from lipotoxicity via modulation of the antioxidant response and enhance lipid droplet formation via an SCD-1-dependent mechanism. Oxidative stress-related toxicity in hepatocytes can be prevented by enhancing LD formation. Full article

Low-grade chronic inflammation may impact liver disease. We investigated the extent to which circulating GlycA, a glycoprotein biomarker of low-grade inflammation, and high-sensitivity C-reactive protein (hs-CRP) are altered in patients with cirrhosis and liver transplant recipients (LTRs) and examined their associations with all-cause mortality. Plasma GlycA (nuclear magnetic resonance spectroscopy) and hs-CRP (nephelometry) were assessed in 129 patients with cirrhosis on the waiting list for liver transplantation and 367 LTRs (TransplantLines cohort study; NCT03272841) and compared with 4837 participants from the population-based PREVEND cohort. GlycA levels were lower, while hs-CRP levels were higher in patients with cirrhosis compared to PREVEND participants (p < 0.001). Notably, GlycA increased, but hs-CRP decreased after transplantation. In LTRs, both GlycA and hs-CRP levels were higher than in PREVEND participants (p < 0.001). Survival was impaired in patients with cirrhosis and LTRs with the highest GlycA and the highest hs-CRP tertiles. In Cox regression analysis, GlycA remained associated with mortality in cirrhotic patients after adjusting for potential confounders and for hs-CRP (HR per 1-SD increment: 2.34 [95% CI 1.07–5.13]), while the association with hs-CRP after adjusting was lost. In LTRs, both GlycA and hs-CRP were also associated with mortality (adjusted HR: 1.60 [95% CI: 1.2–2.14] and 1.64 [95% CI: 1.08–2.51], respectively) but not independent of each other. GlycA increases while hs-CRP decreases after liver transplantation. Both inflammatory markers may be associated with all-cause mortality in cirrhotic patients and LTRs, while the association for GlycA seems at least as strong as that for hs-CRP. Full article

Circulating citrate may serve as a proxy for mitochondrial dysfunction which plays a role in the progression of end-stage liver disease (ESLD). This study aimed to determine the extent of alterations in circulating citrate in patients with ESLD, and examined its association with all-cause mortality among ESLD patients while on the waiting list for liver transplantation. Plasma citrate levels were measured using nuclear magnetic resonance spectroscopy in 129 ESLD patients (TransplantLines cohort study; NCT03272841) and compared to levels in 4837 participants of the community-dwelling PREVEND cohort. Plasma citrate levels were 40% higher in ESLD patients compared to PREVEND participants (p < 0.001). In a subset of 30 ESLD patients, citrate decreased following liver transplantation (p < 0.001), resulting in levels that were slightly lower than those observed in PREVEND participants. In multivariable analysis, plasma citrate levels were positively associated with Child–Turcotte–Pugh classification and inversely associated with estimated glomerular filtration rate (both p < 0.05). Survival was significantly reduced in ESLD patients in the highest citrate tertile (log-rank p = 0.037). Elevated citrate levels were associated with an increased risk of all-cause mortality in ESLD patients (HR per 1 Ln SD increment: 1.65 [95% CI: 1.03–2.63], p = 0.037). This association was suggested to be particularly present in men (HR: 2.04 [95% CI: 1.08–3.85], p = 0.027). In conclusion, plasma citrate levels are elevated in ESLD patients and decrease following liver transplantation. Moreover, elevated plasma citrate levels may be associated with increased all-cause mortality in ESLD patients, likely more pronounced in men. Full article

Liver transplant recipients (LTRs) have lower long-term survival rates compared with the general population. This underscores the necessity for developing biomarkers to assess post-transplantation mortality. Here we compared plasma trimethylamine-N-oxide (TMAO) levels with those in the general population, investigated its determinants, and interrogated its association with all-cause mortality in stable LTRs. Plasma TMAO was measured in 367 stable LTRs from the TransplantLines cohort (NCT03272841) and in 4837 participants from the population-based PREVEND cohort. TMAO levels were 35% higher in LTRs compared with PREVEND participants (4.3 vs. 3.2 µmol/L, p < 0.001). Specifically, TMAO was elevated in LTRs with metabolic dysfunction-associated steatotic liver disease, alcohol-associated liver disease, and polycystic liver disease as underlying etiology (p < 0.001 for each). Among LTRs, TMAO levels were independently associated with eGFR (std. β = −0.43, p < 0.001) and iron supplementation (std. β = 0.13, p = 0.008), and were associated with mortality (29 deaths during 8.6 years follow-up; log-rank test p = 0.017; hazard ratio of highest vs. lowest tertile 4.14, p = 0.007). In conclusion, plasma TMAO is likely elevated in stable LTRs, with impaired eGFR and iron supplementation as potential contributory factors. Our preliminary findings raise the possibility that plasma TMAO could contribute to increased mortality risk in such patients, but this need to be validated through a series of rigorous and methodical studies. Full article

This comprehensive review focuses on the dynamics of branched-chain amino acids (BCAAs) metabolism and its clinical implications in chronic liver disease, with emphasis on the emerging concept of muscle–liver crosstalk. BCAAs, indispensable for protein synthesis and metabolic pathways, undergo unique tissue-specific processing in skeletal muscle and liver. The liver, responsible for amino acid metabolism, plays a distinctive role in sensing BCAAs catabolism, influencing glucose regulation and contributing to the systemic metabolism of BCAAs. Within the context of chronic liver disease, compromised liver metabolism becomes evident through amino acid abnormalities, particularly in the decrease of the Fischer ratio (BCAAs/aromatic amino acids concentrations in plasma). This reduction becomes important in assessing the severity of liver dysfunction due to its associations with adverse outcomes, including increased mortality and complications related to the liver disease. BCAAs supplementation, as explored in this review, emerges as a promising avenue, displaying positive effects on skeletal muscle mass, strength, and overall nutritional status in cirrhosis management. Understanding this interplay offers insights into therapeutic strategies for chronic liver diseases, exploring the way for precision interventions in clinical practice. Full article

Coumarin derivates have been proposed as a potential treatment for metabolic-dysfunction-associated fatty liver disease (MAFLD). However, the mechanisms underlying their beneficial effects remain unclear. In the present study, we explored the potential of the coumarin derivate esculetin in MAFLD, focusing on hepatocyte lipotoxicity and lipid accumulation. Primary cultures of rat hepatocytes were exposed to palmitic acid (PA) and palmitic acid plus oleic acid (OA/PA) as models of lipotoxicity and lipid accumulation, respectively. Esculetin significantly reduced oxidative stress in PA-treated hepatocytes, as shown by decreased total reactive oxygen species (ROS) and mitochondrial superoxide production and elevated expression of antioxidant genes, including Nrf2 and Gpx1. In addition, esculetin protects against PA-induced necrosis. Esculetin also improved lipid metabolism in primary hepatocytes exposed to nonlipotoxic OA/PA by decreasing the expression of the lipogenesis-related gene Srebp1c and increasing the expression of the fatty acid β-oxidation-related gene Ppar-α. Moreover, esculetin attenuated lipid accumulation in OA/PA-treated hepatocytes. The protective effects of esculetin against lipotoxicity and lipid accumulation were shown to be dependent on the inhibition of JNK and the activation of AMPK, respectively. We conclude that esculetin is a promising compound to target lipotoxicity and lipid accumulation in the treatment of MAFLD. Full article

Decreased circulating branched chain amino acids (BCAA) represent a prominent change in amino acid profiles in patients with end-stage liver disease (ESLD). These alterations are considered to contribute to sarcopenia and hepatic encephalopathy and may relate to poor prognosis. Here, we cross-sectionally analyzed the association between plasma BCAA levels and the severity of ESLD and muscle function in participants of the liver transplant subgroup of TransplantLines, enrolled between January 2017 and January 2020. Plasma BCAA levels were measured by nuclear magnetic resonance spectroscopy. Physical performance was analyzed with a hand grip strength test, 4 m walking test, sit-to-stand test, timed up and go test, standing balance test and clinical frailty scale. We included 92 patients (65% men). The Child Pugh Turcotte classification was significantly higher in the lowest sex-stratified BCAA tertile compared to the highest tertile (p = 0.015). The times for the sit-to-stand (r = −0.352, p < 0.05) and timed up and go tests (r = −0.472, p < 0.01) were inversely correlated with total BCAA levels. In conclusion, lower circulating BCAA are associated with the severity of liver disease and impaired muscle function. This suggests that BCAA may represent a useful prognostic marker in the staging of liver disease severity. Full article

A molecular characterization of the main phytochemicals and antioxidant activity of Opuntia robusta (OR) fruit extract was carried out, as well as an evaluation of its hepatoprotective effect against diclofenac (DF)-induced acute liver injury was evaluated. Phenols, flavonoids and betalains were quantified, and antioxidant characterization was performed by means of the ABTS^•+, DPPH and FRAP assays. UPLC-QTOF-MS/MS was used to identify the main biocompounds present in OR fruit extract was carried out via. In the in vivo model, groups of rats were treated prophylactically with the OR fruit extract, betanin and N-acteylcysteine followed by a single dose of DF. Biochemical markers of oxidative stress (MDA and GSH) and relative gene expression of the inducible antioxidant response (Nrf2, Sod2, Hmox1, Nqo1 and Gclc), cell death (Casp3) and DNA repair (Gadd45a) were analyzed. Western blot analysis was performed to measure protein levels of Nrf2 and immunohistochemical analysis was used to assess caspase-3 activity in the experimental groups. In our study, the OR fruit extract showed strong antioxidant and cytoprotective capacity due to the presence of bioactive compounds, such as betalain and phenols. We conclude that OR fruit extract or selected components can be used clinically to support patients with acute liver injury. Full article

Liver fibrosis is a chronic disease associated with oxidative stress that has a great impact on the population mortality. Due to their antioxidant capacity, we evaluated the protective effect of Opuntia robusta fruit (Or) on liver fibrosis. A nutraceutical characterization of Or was performed and a model of fibrosis was induced with thioacetamide (TAA) in Wistar rats. Aminotransferases, reduced glutathione (GSH) and histopathology were evaluated. Or contained 436.5 ± 57 mg of Betacyanins equivalents/L., 793 mg of catechin equivalents (CAE)/100 g for flavonoids, 1118 mg of gallic acid equivalents (GAE)/100 g for total phenols, 141.14 mg/100 g for vitamin C and 429.9 μg/100 g for vitamin E. The antioxidant capacity of Or was: 2.27 mmol of Trolox^® equivalents (TE)/L (DPPH), 62.2 ± 5.0 μmol TE/g (ABTS^•+), 80.2 ± 11.7 μmol TE/g (FRAP), 247.9 ± 15.6 µmol TE/g (AAPH) and 15.0% of H₂O₂ elimination. An increase (p < 0.05) of aminotransferases and a decrease (p < 0.05) of hepatic GSH was observed in the TAA group compared to the control and the concomitant groups. Histopathology showed changes in the normal architecture of the liver treated with TAA compared to the concomitant treatments. Or contains bioactive components with antioxidant capacity, which can reduce fibrotic liver damage. Full article

Non-alcoholic fatty liver disease is characterized by disturbed lipid metabolism and increased oxidative stress. These conditions lead to the activation of different cellular response mechanisms, including senescence. Cellular senescence constitutes an important response to injury in the liver. Recent findings show that chronic oxidative stress can induce senescence, and this might be a driving mechanism for NAFLD progression, aggravating the disturbance of lipid metabolism, organelle dysfunction, pro-inflammatory response and hepatocellular damage. In this context, the modulation of cellular senescence can be beneficial to ameliorate oxidative stress-related damage during NAFLD progression. This review focuses on the role of oxidative stress and senescence in the mechanisms leading to NAFLD and discusses the possibilities to modulate senescence as a therapeutic strategy in the treatment of NAFLD. Full article

Celiac disease (CeD) is a chronic autoimmune disorder characterized by an intolerance to storage proteins of many grains. CeD is frequently associated with liver damage and steatosis. Bile acid (BA) signaling has been identified as an important mediator in gut–liver interaction and the pathogenesis of non-alcoholic fatty liver disease (NAFLD). Here, we aimed to analyze BA signaling and liver injury in CeD patients. Therefore, we analyzed data of 20 CeD patients on a gluten-free diet compared to 20 healthy controls (HC). We furthermore analyzed transaminase levels, markers of cell death, BA, and fatty acid metabolism. Hepatic steatosis was determined via transient elastography, by MRI and non-invasive scores. In CeD, we observed an increase of the apoptosis marker M30 and more hepatic steatosis as compared to HC. Fibroblast growth factor 19 (FGF19) was repressed in CeD, while low levels were associated with steatosis, especially in patients with high levels of anti-tissue transglutaminase antibodies (anti-tTG). When comparing anti-tTG-positive CeD patients to individuals without detectable anti-tTG levels, hepatic steatosis was accentuated. CeD patients with significant sonographic steatosis (defined by CAP ≥ 283 db/m) were exclusively anti-tTG-positive. In summary, our results suggest that even in CeD patients in clinical remission under gluten-free diet, alterations in gut–liver axis, especially BA signaling, might contribute to steatotic liver injury and should be further addressed in future studies and clinical practice. Full article

Oxidative stress (OxS) is considered a major factor in the pathophysiology of inflammatory chronic liver diseases, including non-alcoholic liver disease (NAFLD). Chronic impairment of lipid metabolism is closely related to alterations of the oxidant/antioxidant balance, which affect metabolism-related organelles, leading to cellular lipotoxicity, lipid peroxidation, chronic endoplasmic reticulum (ER) stress, and mitochondrial dysfunction. Increased OxS also triggers hepatocytes stress pathways, leading to inflammation and fibrogenesis, contributing to the progression of non-alcoholic steatohepatitis (NASH). The antioxidant response, regulated by the Nrf2/ARE pathway, is a key component in this process and counteracts oxidative stress-induced damage, contributing to the restoration of normal lipid metabolism. Therefore, modulation of the antioxidant response emerges as an interesting target to prevent NAFLD development and progression. This review highlights the link between disturbed lipid metabolism and oxidative stress in the context of NAFLD. In addition, emerging potential therapies based on antioxidant effects and their likely molecular targets are discussed. Full article

Upon liver injury, hepatic stellate cells (HSCs) transdifferentiate to migratory, proliferative and extracellular matrix-producing myofibroblasts (e.g., activated HSCs; aHSCs) causing liver fibrosis. HSC activation is associated with increased glycolysis and glutaminolysis. Here, we compared the contribution of glycolysis, glutaminolysis and mitochondrial oxidative phosphorylation (OXPHOS) in rat and human HSC activation. Basal levels of glycolysis (extracellular acidification rate ~3-fold higher) and particularly mitochondrial respiration (oxygen consumption rate ~5-fold higher) were significantly increased in rat aHSCs, when compared to quiescent rat HSC. This was accompanied by extensive mitochondrial fusion in rat and human aHSCs, which occurred without increasing mitochondrial DNA content and electron transport chain (ETC) components. Inhibition of glycolysis (by 2-deoxy-D-glucose) and glutaminolysis (by CB-839) did not inhibit rat aHSC proliferation, but did reduce Acta2 (encoding α-SMA) expression slightly. In contrast, inhibiting mitochondrial OXPHOS (by rotenone) significantly suppressed rat aHSC proliferation, as well as Col1a1 and Acta2 expression. Other than that observed for rat aHSCs, human aHSC proliferation and expression of fibrosis markers were significantly suppressed by inhibiting either glycolysis, glutaminolysis or mitochondrial OXPHOS (by metformin). Activation of HSCs is marked by simultaneous induction of glycolysis and mitochondrial metabolism, extending the possibilities to suppress hepatic fibrogenesis by interfering with HSC metabolism. Full article