Oxidative stress is a key contributor to the onset and progression of diverse pathological conditions, including metabolic dysfunction-associated steatotic liver disease (MASLD), neurodegeneration, cardiovascular disorders, and cancer. Conventional antioxidant therapies, such as small-molecule scavengers or systemic enzyme administration, are limited by poor stability, inefficient delivery, and off-target effects. Extracellular vesicles (EVs), particularly exosomes, are increasingly recognized as natural carriers of antioxidant enzymes (AOEs), including catalase, superoxide dismutases, glutathione peroxidases, peroxiredoxins, and thioredoxin. These vesicles not only protect enzymes from degradation but also enable targeted delivery to recipient cells, where they can actively modulate redox homeostasis. In this review, we summarize current evidence for AOEs as bona fide EV cargo, outline mechanisms that govern their selective packaging and transfer, and highlight their roles in intercellular communication under physiological and pathological conditions. We also discuss emerging therapeutic applications of both natural and engineered EVs for redox modulation, along with the challenges of quantifying enzymatic activity, ensuring reproducibility, and scaling clinical translation. By integrating insights from cell biology, redox signaling, and translational research, we propose that EV-mediated AOE delivery represents a promising next-generation strategy for combating oxidative stress-related diseases.

Extracorporeal membrane oxygenation (ECMO) is a life-saving intervention for patients with circulatory and/or pulmonary failure; however, the rate of complications remains high. ECMO induces systemic inflammation, which may activate and damage the endothelium, thereby causing edema and organ dysfunction. Advancing our understanding in this area is crucial for improving patient outcomes during ECMO. The goal of this review is to summarize the current evidence of the effects of ECMO on endothelial activation and damage in both animals and patients. PubMed and Embase databases were systematically searched for both clinical and animal studies including ECMO support. The outcome parameters were markers of endothelial activation and damage or (in)direct measurements of endothelial permeability, fluid leakage and edema. In total, 26 studies (patient n = 16, animal n = 10) fulfilled all eligibility criteria, and used VA-ECMO (n = 13) or VV-ECMO (n = 6), or remained undefined (n = 7). The most frequently studied endothelial activation markers were adhesion molecules (ICAM-1) and selectins (E- and P-selectin). The levels of endothelial activation markers were comparable to or higher than in healthy controls. Compared to pre-ECMO or non-ECMO, the majority of studies showed stable or decreased levels. Angiopoietin-2, von Willebrand Factor and extracellular vesicles were the most widely studied circulating markers of endothelial damage. More than half of the included studies showed increased levels when compared to normal ranges, and pre-ECMO or non-ECMO values. In healthy animals, ECMO itself leads to vascular leakage and edema. The effect of ECMO support in critically ill animals showed contradicting results. ECMO support (further) induces endothelial damage, but endothelial activation does not, in the critically ill. Further research is necessary to conclude on the effect of the underlying comorbidity and type of ECMO support applied on endothelial dysfunction.

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.

Liver diseases represent a major global health challenge, yet current treatment options remain insufficient, highlighting the need for new therapeutic strategies. Recent research underscores the crucial role of the gut microbiota and their metabolites in liver disease progression. Emerging evidence suggests that bacterial extracellular vesicles (BEVs), membrane‐bound vesicles secreted by bacteria, play a critical role in hepatic inflammation, fibrosis, metabolic dysregulation, and tumor development, while commensal and probiotic‐derived BEVs exhibit protective effects against these pathologies. This review provides a comprehensive overview of BEVs and their diverse roles in liver disease progression and treatment. Additionally, we discuss the current challenges in BEV research and propose future directions to improve our understanding of their effects on liver health and their potential therapeutic applications.

Metabolic dysfunction-associated steatotic liver disease (MASLD) is increasing in both prevalence and severity, highlighting the need for non-invasive biomarkers to assess disease activity. Extracellular vesicles (EVs), which carry molecular cargo from their cells of origin, hold promise as accessible biomarkers. We performed proteomic profiling of plasma-derived EVs from 70 patients with MASLD to identify protein signatures associated with key histological features (steatosis, metabolic dysfunction-associated steatohepatitis (MASH), and fibrosis). These proteins were subsequently correlated with magnetic resonance (MR)-based liver imaging. Plasma EV protein profile differed between mild (S1) and advanced steatosis (S3). H4C1, OIT3, and ANPEP were elevated in S3, while CCDC25 and KLHL41 were decreased (|log₂ fold change| > 1, p < 0.05). KLHL41 had a weak-to-moderate correlation with proton density fat fraction (PDFF) (R = −0.34, p = 0.016). GP1BA was upregulated in MASH (log₂ fold change = 1.13, p = 0.03) but showed weak correlation with cT1, an imaging parameter for steatohepatitis (R = 0.22, p = 0.173). In fibrosis, complement component 7 (C7) was elevated in advanced (≥F3) vs. mild fibrosis (<F2) (log₂ fold change = 0.95, adjusted p = 0.002) and correlated with MR elastography-derived liver stiffness (R = 0.38, p = 0.004). The AUC of C7 for differentiating <F2 vs. ≥F2 and <F3 vs. ≥F3 was 0.80 (95% CI: 0.69–0.91) and 0.83 (95% CI: 0.72–0.93), respectively. In conclusion, plasma EVs contain distinct protein signatures associated with steatosis, steatohepatitis, and fibrosis in MASLD. These preliminary findings support the potential utility of plasma EVs as non-invasive biomarkers and provide insights into disease pathophysiology. However, further validation in larger, independent cohorts is necessary to confirm these associations and establish their clinical relevance.

Background and Aims: Branched‐chain amino acids ( BCAA ) have gained increasing recognition for their role in liver disease. This study investigated plasma BCAA alterations in patients with cirrhosis and liver transplant recipients ( LTRs ) and examined their associations with all‐cause mortality and new‐onset type 2 diabetes in LTRs . Methods: Plasma BCAA concentrations were measured using nuclear magnetic resonance spectroscopy in 129 patients with cirrhosis and 367 LTRs from the TransplantLines cohort study ( NCT03272841 ), and compared with 4834 participants from the population‐based PREVEND cohort. Kaplan–Meier survival analysis and Cox regression analysis were performed. Results: Total BCAA levels were significantly lower in patients with cirrhosis and LTRs than in PREVEND participants ( p < .001). While total BCAA levels increased post‐transplant, they remained lower than those in PREVEND ( p < .001). The highest total BCAA tertile was associated with better survival versus the lowest BCAA tertile in patients with cirrhosis (log‐rank p = .002). In Cox regression analysis adjusted for relevant co‐variates, higher total BCAA levels were also associated with reduced mortality in patients with cirrhosis ( HR .19 [95% CI : .04–.86], p = .031). In LTRs , the highest total BCAA tertile conferred a higher probability of new‐onset diabetes (log‐rank p = .004) but was not linked to mortality (log‐rank p = .65). After adjusting for age, sex, and immunosuppressant use, the highest tertile of total BCAA levels remained independently associated with new‐onset diabetes in LTRs ( HR 1.42 [95% CI : 1.10–1.82], p = .006). Conclusions: Total BCAA levels increase after liver transplantation. In patients with cirrhosis, higher total BCAA levels are associated with reduced all‐cause mortality. Although this association is not evident in LTRs , higher total BCAA levels are strongly linked to an increased risk of new‐onset type 2 diabetes, warranting further investigation.