Search Results (4,861)

Obstructive sleep apnea (OSA), characterized by intermittent hypoxia (IH), is strongly associated with metabolic syndrome and metabolic dysfunction-associated steatotic liver disease (MASLD). IH exacerbates MASLD progression through oxidative stress, inflammation, and lipid accumulation. This study aims to investigate the impact of oxygen normalization on metabolic dysfunction in OSA patients using continuous positive airway pressure (CPAP) therapy, and in mice exposed to IH followed by a reoxygenation period. In the clinical study, 76 participants (44 OSA patients and 32 controls) were analyzed. OSA patients had higher insulin resistance, triglycerides, very low density lipoprotein (VLDL) content, and liver enzyme levels, along with a higher prevalence of liver steatosis. After 18 months of CPAP therapy, OSA patients showed significant improvements in insulin resistance, lipid profiles (total cholesterol and VLDL), liver function markers (AST and albumin), and steatosis risk scores (Fatty Liver Index and OWLiver test). In the experimental study, IH induced hepatic lipid accumulation, oxidative stress, and inflammation, and reoxygenation reversed these deleterious effects in mice. At the molecular level, IH downregulated fatty acid oxidation (FAO)-related genes, thus impairing the FAO process. Reoxygenation maintained elevated levels of lipogenic genes but restored FAO gene expression and activity, suggesting enhanced lipid clearance despite ongoing lipogenesis. Indeed, serum β hydroxybutyrate, a key marker of hepatic FAO in patients, was impaired in OSA patients but normalized after CPAP therapy, supporting improved FAO function. CPAP therapy improves lipid profiles, liver function, and MASLD progression in OSA patients. Experimental findings highlight the therapeutic potential of oxygen normalization in reversing IH-induced liver damage by FAO pathway restoration, indicating a metabolic reprogramming in the liver. Full article

Heme, an essential prosthetic group involved in mitochondrial respiration and transcriptional regulation, is synthesized via the rate-limiting enzyme 5-aminolevulinic acid synthase (ALAS). Utilizing heterozygous mouse models for ALAS1 and ALAS2, our studies have revealed diverse systemic consequences of chronic heme deficiency. ALAS1-heterozygous (ALAS1+/−) mice develop metabolic dysfunction characterized by insulin resistance, glucose intolerance, and abnormal glycogen accumulation, linked mechanistically to reduced AMP-activated protein kinase (AMPK) signaling. These mice also exhibit pronounced mitochondrial dysfunction, impaired autophagy, and accelerated aging phenotypes, including sarcopenia and metabolic decline, highlighting heme’s role as a critical metabolic regulator. Additionally, ALAS2 heterozygosity (ALAS2+/−) leads to impaired erythropoiesis, resulting in anemia and ineffective iron utilization. Importantly, supplementation with the heme precursor 5-aminolevulinic acid (5-ALA) significantly mitigates ALAS1+/− phenotypes, restoring metabolic function, mitochondrial health, autophagy, and immune competence. This review encapsulates key findings from our group’s research together with advances made by multiple research groups over the past decade, collectively establishing heme homeostasis as a central regulator of systemic physiology and highlighting the therapeutic potential of 5-ALA in treating heme-deficient pathologies. Full article

Sepsis-induced myocardial injury is age-related and leads to increased mortality. Considering the importance of mitochondrial dysfunction in cardiac impairment, we aimed to investigate whether aging exacerbates the cardiac mitochondrial metabolic response to inflammation, thus leading to increased cardiac dysfunction in the elderly. Cecal ligation and puncture (CLP) was conducted in young adult (12–18 weeks) and aged (19–21 months) male C57BL/6 mice. Cardiac function was detected 20 h post-CLP. Additionally, cardiomyocytes isolated from young adult and aged male mice were used for assessments of mitochondrial respiratory function +/– TNFα or LPS. Protein levels of oxidative phosphorylation (OXPHOS), NADPH oxidase (NOX)2, NOX4, phosphor-STAT3 and STAT3 were determined in mouse hearts 24 h post-CLP and in cardiomyocytes following inflammatory stimuli. CLP significantly reduced cardiac contractility in both young and aged mice, with a higher incidence and greater severity of cardiac functional depression in the older group. Mitochondrial respiratory capacity was decreased in cardiomyocytes derived from aged mice, with increased susceptible to inflammatory toxic effects compared to those from young adult mice. The age-dependent changes were observed in myocardial OXPHOS complexes and NOX4. Importantly, CLP led to a significant increase in OXPHOS protein levels in the hearts of older mice, suggesting a possible compensatory response to decreased mitochondrial metabolic function and a greater potential for reactive oxygen species (ROS) generation. Our findings highlight that the response of aging-impaired mitochondria to inflammation may underlie the worsened cardiac functional depression in the aged group during sepsis. Full article

Moyamoya disease (MMD) is primarily associated with genetic variants in RNF213. RNF213 p.R4810K (c.14429G>A, p.Arg4810Lys) is a founder variant predominantly found in East Asian populations and is strongly associated with MMD, a rare cerebrovascular condition characterized by progressive stenosis of intracranial arteries and the development of abnormal collateral networks. Recent evidence suggests that RNF213 variants are also enriched in non-moyamoya intracranial arteriopathies, such as large-artery atherosclerotic stroke and intracranial arterial stenosis/occlusion (ICASO), particularly in east Asian individuals with early-onset or cryptogenic stroke. This expanded phenotypic spectrum, termed RNF213-related vasculopathy (RRV), represents a distinct pathogenic entity that may involve unique pathogenic processes separate from traditional atherosclerosis. In this review, we synthesize current genetic, clinical, radiological, and experimental findings that delineate the unique features of RRV. Patients with RRV typically exhibit a lower burden of traditional vascular risk factors, negative vascular remodeling in the absence of atheromatous plaques, and an increased propensity for disease progression. RNF213 variants may compromise vascular resilience by impairing adaptive responses to hemodynamic stress. Furthermore, emerging cellular and animal model data indicate that RNF213 influences angiogenesis, lipid metabolism, and stress responses, offering mechanistic insights into its role in maintaining vascular integrity. Recognizing RRV as a distinct clinical entity has important implications for diagnosis, risk stratification, and the development of genome-informed therapeutic strategies. Full article

The retina is highly sensitive to oxygen and blood supply, and hypoxia plays a key role in retinal diseases such as diabetic retinopathy (DR) and age-related macular degeneration (AMD). Müller glial cells, which are essential for retinal homeostasis, respond to injury and hypoxia with reactive gliosis, characterized by the upregulation of the glial fibrillary acidic protein (GFAP) and vimentin, cellular hypertrophy, and extracellular matrix changes, which can impair retinal function and repair. The retinal pigment epithelium (RPE) supports photoreceptors, forms part of the blood–retinal barrier, and protects against oxidative stress; its dysfunction contributes to retinal degenerative diseases such as AMD, retinitis pigmentosa (RP), and Stargardt disease (SD). Extracellular vesicles (EVs) play a crucial role in intercellular communication, protein homeostasis, and immune modulation, and have emerged as promising diagnostic and therapeutic tools. Understanding the role of extracellular vesicles’ (EVs’) signaling machinery of glial cells and the retinal pigment epithelium (RPE) is critical for developing effective treatments for retinal degeneration. In this study, we investigated the bidirectional EV-mediated crosstalk between RPE and Müller cells under hypoxic conditions and its impact on cellular metabolism and retinal cell integrity. Our findings demonstrate that RPE-derived extracellular vesicles (RPE EVs) induce time-dependent metabolic reprogramming in Müller cells. Short-term exposure (24 h) promotes pathways supporting neurotransmitter cycling, calcium and mineral absorption, and glutamate metabolism, while prolonged exposure (72 h) shifts Müller cell metabolism toward enhanced mitochondrial function and ATP production. Conversely, Müller cell-derived EVs under hypoxia influenced RPE metabolic pathways, enhancing fatty acid metabolism, intracellular vesicular trafficking, and the biosynthesis of mitochondrial co-factors such as ubiquinone. Proteomic analysis revealed significant modulation of key regulatory proteins. In Müller cells, hypoxic RPE-EV exposure led to reduced expression of Dyskerin Pseudouridine Synthase 1 (DKc1), Eukaryotic Translation Termination Factor 1 (ETF1), and Protein Ser/Thr phosphatases (PPP2R1B), suggesting alterations in RNA processing, translational fidelity, and signaling. RPE cells exposed to hypoxic Müller cell EVs exhibited elevated Ribosome-binding protein 1 (RRBP1), RAC1/2, and Guanine Nucleotide-Binding Protein G(i) Subunit Alpha-1 (GNAI1), supporting enhanced endoplasmic reticulum (ER) function and cytoskeletal remodeling. Functional assays also revealed the compromised barrier integrity of the outer blood–retinal barrier (oBRB) under hypoxic co-culture conditions. These results underscore the adaptive but time-sensitive nature of retinal cell communication via EVs in response to hypoxia. Targeting this crosstalk may offer novel therapeutic strategies to preserve retinal structure and function in ischemic retinopathies. Full article

Obesity, type 2 diabetes mellitus (T2DM) and steatohepatitis associated with metabolic dysfunction (MASLD) are on the rise and pose serious health challenges worldwide. In recent years, researchers have gained a better understanding of the important role of the gut microbiota in the development and progression of these diseases. Intestinal dysbiosis can contribute to the occurrence of increased intestinal permeability, inflammation and reduced numbers of commensal bacteria. In obesity, these changes contribute to chronic low-grade inflammation and deregulated metabolism. In MASLD, gut microbiota dysbiosis can promote liver fibrosis and impair bile acid metabolism, while in T2DM, they are associated with impaired glycemic control and insulin resistance. Regular physical activity has a positive effect on the composition of the gut microbiota, increasing its diversity, modulating its metabolic functions, strengthening the intestinal barrier and reducing inflammation. These findings suggest that exercise and microbiota-targeted interventions may play an important role in the prevention and treatment of metabolic diseases. Full article

Circadian rhythms are intrinsic 24 h cycles that regulate metabolic processes across multiple tissues, with skeletal muscle emerging as a central node in this temporal network. Muscle clocks govern gene expression, fuel utilisation, mitochondrial function, and insulin sensitivity, thereby maintaining systemic energy homeostasis. However, circadian misalignment, whether due to behavioural disruption, nutrient excess, or metabolic disease, impairs these rhythms and contributes to insulin resistance, and the development of obesity, and type 2 diabetes mellitus. Notably, the muscle clock remains responsive to non-photic cues, particularly exercise, which can reset and amplify circadian rhythms even in metabolically impaired states. This work synthesises multi-level evidence from rodent models, human trials, and in vitro studies to elucidate the role of skeletal muscle clocks in circadian metabolic health. It explores how exercise entrains the muscle clock via molecular pathways involving AMPK, SIRT1, and PGC-1α, and highlights the time-of-day dependency of these effects. Emerging data demonstrate that optimally timed exercise enhances glucose uptake, mitochondrial biogenesis, and circadian gene expression more effectively than time-agnostic training, especially in individuals with metabolic dysfunction. Finally, findings are integrated from multi-omic approaches that have uncovered dynamic, time-dependent molecular signatures that underpin circadian regulation and its disruption in obesity. These technologies are uncovering biomarkers and signalling nodes that may inform personalised, temporally targeted interventions. By combining mechanistic insights with translational implications, this review positions skeletal muscle clocks as both regulators and therapeutic targets in metabolic disease. It offers a conceptual framework for chrono-exercise strategies and highlights the promise of multi-omics in developing precision chrono-medicine approaches aimed at restoring circadian alignment and improving metabolic health outcomes. Full article

Background: Exercise-induced fatigue arises primarily from energy substrate depletion and the accumulation of metabolites such as lactate and ammonia, which impair performance and delay recovery. Emerging evidence implicates gut microbiota modulation—particularly via probiotics—as a means to optimize host energy metabolism and accelerate clearance of fatigue-associated by-products. Objective: This study aimed to determine whether live or heat-inactivated Lacticaseibacillus paracasei NB23 can enhance exercise endurance and attenuate fatigue biomarkers in a murine model. Methods: Forty male Institute of Cancer Research (ICR) mice were randomized into four groups (n = 10 each) receiving daily gavage for six weeks with vehicle, heat-killed NB23 (3 × 10¹⁰ cells/mouse/day), low-dose live NB23 (1 × 10¹⁰ CFU/mouse/day), or high-dose live NB23 (3 × 10¹⁰ CFU/mouse/day). Forelimb grip strength and weight-loaded swim-to-exhaustion tests assessed performance. Blood was collected post-exercise to measure serum lactate, ammonia, blood urea nitrogen (BUN), and creatine kinase (CK). Liver and muscle glycogen content was also quantified, and safety was confirmed by clinical-chemistry panels and histological examination. Results: NB23 treatment produced dose-dependent improvements in grip strength (p < 0.01) and swim endurance (p < 0.001). All NB23 groups exhibited significant reductions in post-exercise lactate (p < 0.0001), ammonia (p < 0.001), BUN (p < 0.001), and CK (p < 0.0001). Hepatic and muscle glycogen stores rose by 41–59% and 65–142%, respectively (p < 0.001). No changes in food or water intake, serum clinical-chemistry parameters, or tissue histology were observed. Conclusions: Our findings suggest that both live and heat-treated L. paracasei NB23 may contribute to improved endurance performance, increased energy reserves, and faster clearance of fatigue-related metabolites in our experimental model. However, these results should be interpreted cautiously given the exploratory nature and limitations of our study. Full article

Introduction: Vitamin D deficiency, a reversible cause of osteoporosis, is increasingly prevalent, showing varying degrees of severity that are notably pronounced among the growing population of multimorbid elderly patients. Given that the aging pancreas undergoes senescent processes leading to impaired function—which negatively impacts enteral vitamin D absorption and, consequently, elderly bone metabolism—a specific diagnostic and treatment approach is crucial. Our study aimed to determine the prevalence of vitamin D deficiency and exocrine pancreatic insufficiency (EPI) in orthogeriatric patients. We also evaluated differences in vitamin D deficiency severity between patients with normal and impaired pancreatic function. Furthermore, a short-term monitoring of vitamin D level increases after 12 days of substitution therapy in both groups aimed to inform osteoanabolic therapy for specific high-fracture-risk patients, assessing the influence of pancreatic function on substitution efficacy. Methods: We conducted a retrospective, monocentric cohort study, evaluating data from all patients hospitalized with manifest osteoporosis in an orthogeriatric department during a six-month spring/summer period. Demographic data, relevant comorbidities, the type of fracture, the amount of faecal elastase 1 (CALEX^® Cap Bühlmann), and the serum levels of 25-hydroxyvitamin D (25(OH)D) were assessed. Results: We found a high prevalence (70.6%) of vitamin D deficiency (25(OH)D < 30 µg/L) among all orthogeriatric patients. Of these, 16% met the criteria for mild to severe EPI. The group with normal exocrine pancreatic function showed a higher average vitamin D value, and their increase in vitamin D levels following short-term substitution was up to 100% greater compared to the group with impaired pancreatic function. Notably, 69% of women and 20% of men met the therapeutic threshold for specific osteoanabolic osteoporosis therapy, even without a T-score. Conclusions: Our findings reveal a very high prevalence of vitamin D deficiency and a high prevalence of EPI in orthogeriatric patients. Those with impaired exocrine pancreatic function exhibit lower baseline vitamin D levels and a diminished capacity for vitamin D absorption during short-term monitoring. These results have significant clinical implications for osteoporotic therapy, given that a substantial proportion of patients, particularly women, meet the criteria for specific osteoanabolic treatment. Full article

Glioblastoma (GBM) is a highly aggressive brain tumor marked by invasive growth and therapy resistance. Tumor cells adapt to hostile conditions, such as hypoxia and nutrient deprivation, by activating survival mechanisms including autophagy and metabolic reprogramming. Among GBM-associated changes, hypersialylation, particularly, the aberrant expression of polysialic acid (PSA), has been linked to increased plasticity, motility, and immune evasion. PSA, a long α2,8-linked sialic acid polymer typically attached to the NCAM, is abundant in the embryonic brain and re-expressed in cancers, correlating with poor prognosis. Here, we investigated how PSA expression was regulated in GBM cells under nutrient-limiting conditions. Serum starvation induced a marked increase in PSA-NCAM, driven by upregulation of the polysialyltransferase ST8SiaIV and an autophagy-dependent recycling of sialic acids from degraded glycoproteins. Inhibition of autophagy or sialidases impaired PSA induction, and PSA regulation appeared dependent on p53 function. Immunohistochemical analysis of GBM tissues revealed co-localization of PSA and LC3, particularly around necrotic regions. In conclusion, we identified a novel mechanism by which GBM cells sustain PSA-NCAM expression via autophagy-mediated sialic acid recycling under nutrient stress. This pathway may enhance cell migration, immune escape, and stem-like properties, offering a potential therapeutic target in GBM. Full article

Background: Dietary advice for Paralympic athletes (PAs) with a spinal cord injury (PAs-SCI) requires particular attention and has been widely studied. However, currently, no particular attention has been addressed to nutritional guidelines for athletes with an amputation (PAs-AMP). This study aimed at filling up this gap, at least partially, and compared veteran PAs-SCI with PAs-AMP. Methods: A sample of 25 male PAs (12 with SCI and 13 with AMP), recruited during two training camps, was submitted to the following questionnaires: allergy questionnaire for athletes (AQUA), Nordic Musculoskeletal Questionnaire (NMQ), Starvation Symptom Inventory (SSI), neurogenic bowel dysfunction (NBD), orthorexia (ORTO-15/ORTO-7), alcohol use disorders identification test (AUDIT), and Mediterranean diet adherence (MDS). The PAs were also submitted to the following measurements: dietary Oxygen Radical Absorbance Capacity (ORAC) and intakes, body composition, handgrip strength (HGS), basal energy expenditure (BEE), peak oxygen uptake (VO_2peak), peak power, peak heart rate (HR), post-exercise ketosis, and antioxidant response after a cardiopulmonary exercise test (CPET) to voluntary fatigue. Results: Compared to PAs-AMP, PAs-SCI had higher NBD and lower VO_2peak (p < 0.05), peak power, peak HR, peak lactate, phase angle (PhA) of the dominant leg (p < 0.05), and ORTO15 (p < 0.05). The latter was related to NBD (r = −0.453), MDS (r = −0.638), and ORAC (r = −0.529), whereas ORTO7 correlated with PhA of the dominant leg (r = 0.485). Significant differences between PAs-AMP and PAs-SCI were not found in the antioxidant response, glucose, and ketone levels after CPET, nor in dietary intake, AUDIT, AQUA, NMQ, SSI, BEE, HGS, and FM%. Conclusions: The present study showed that PAs-SCI and PAs-AMP display similar characteristics in relation to lifestyle, energy intake, basal energy expenditure, and metabolic response to CPET. Based on both the similarities with PAs-SCI and the consequences of the limb deficiency impairment, PAs-AMP and PAs-SCI require personalized nutritional advice. Full article

The relationship between metabolic dysfunction and mental health disorders is complex and has received increasing attention. This review integrates current research to explore how stress-related growth differentiation factor 15 (GDF15) signaling, ceramides derived from gut microbiota, and mitochondrial dysfunction in the brain interact to influence both metabolic and psychiatric conditions. Evidence suggests that these pathways converge to regulate brain energy homeostasis through feedback mechanisms involving the autonomic nervous system and the hypothalamic–pituitary–adrenal axis. GDF15 emerges as a key stress-responsive biomarker that links peripheral metabolism with brainstem GDNF family receptor alpha-like (GFRAL)-mediated anxiety circuits. Meanwhile, ceramides impair hippocampal mitochondrial function via membrane incorporation and disruption of the respiratory chain. These disruptions may contribute to sustained pathological states such as depression, anxiety, and cognitive dysfunction. Although direct mechanistic data are limited, integrating these pathways provides a conceptual framework for understanding metabolic–psychiatric comorbidities. Furthermore, differences in age, sex, and genetics may influence these systems, highlighting the need for personalized interventions. Targeting mitochondrial function, GDF15-GFRAL signaling, and gut microbiota composition may offer new therapeutic strategies. This integrative perspective helps conceptualize how metabolic and psychiatric mechanisms interact for understanding the pathophysiology of metabolic and psychiatric comorbidities and highlights therapeutic targets for precision medicine. Full article

Chronic low-grade inflammation is a hallmark of both metabolic and neurodegenerative diseases. In recent years, several studies have highlighted the pivotal role of systemic metabolic dysfunction, particularly insulin resistance, in shaping neuroinflammatory processes and contributing to impaired cognitive performance. Among metabolic disorders, type 2 diabetes mellitus has emerged as a major risk factor for the development of age-related neurodegenerative conditions, suggesting a complex and bidirectional crosstalk between peripheral metabolic imbalance and central nervous system function. This review aims to explore the cellular and molecular mechanisms underlying the interaction between metabolic dysregulation and brain inflammation. By integrating current findings from endocrinology, immunology, and neuroscience, this work provides a comprehensive overview of how chronic metabolic inflammation may contribute to the onset and progression of neurodegenerative conditions. This interdisciplinary approach could offer novel insights into potential therapeutic strategies targeting both metabolic and neuroinflammatory pathways. Full article

Early weaning of piglets elicits weaning stress, which in turn induces oxidative stress and consequently impairs growth and development. Hydrogen-rich water (HRW), characterized by selective antioxidant properties, mitigates oxidative stress damage and serves as an ideal intervention. This study aimed to evaluate the effects of HRW on weaned piglets, specifically investigating its impact on growth performance, diarrhea incidence, antioxidant function, intestinal morphology, gut microbiota, and hepatic metabolites. The results demonstrate that HRW significantly increased the average daily feed intake and significantly reduced the diarrhea rate in weaned piglets. Analysis of serum oxidative stress indicators revealed that HRW significantly elevated the activities of total antioxidant capacity and total superoxide dismutase while significantly decreasing malondialdehyde concentration. Assessment of intestinal morphology showed that HRW significantly increased the villus height to crypt depth ratio in the duodenum, jejunum, and ileum. Microbial analysis indicated that HRW significantly increased the abundance of Prevotella in the colon. Furthermore, HRW increased the abundance of beneficial bacteria, such as Akkermansia, in the jejunum and cecum, while concurrently reducing the abundance of harmful bacteria like Escherichia. Hepatic metabolite profiling revealed that HRW significantly altered the metabolite composition in the liver of weaned piglets. Differentially abundant metabolites were enriched in oxidative stress-related KEGG pathways, including ABC transporters; pyruvate metabolism; autophagy; FoxO signaling pathway; glutathione metabolism; ferroptosis; and AMPK signaling pathways. In conclusion, HRW alleviates diarrhea and promotes growth in weaned piglets by enhancing antioxidant capacity. These findings provide a scientific foundation for the application of HRW in swine production and serve as a reference for further exploration into the mechanisms underlying HRW’s effects on animal health and productivity. Full article

Tacrolimus (TAC)-induced chronic nephrotoxicity (TAC nephrotoxicity) remains a major contributor to late allograft dysfunction in kidney transplant recipients. Although detailed mechanisms remain incompletely understood, our previous metabolomic studies revealed disruptions in carnitine-related and redox pathways, suggesting impaired mitochondrial β-oxidation of fatty acids. To further characterize metabolic alterations associated with this condition, we conducted an untargeted lipidomic analysis of renal tissues using a murine model of TAC nephrotoxicity. TAC (1 mg/kg/day) or saline was subcutaneously administered to male ICR mice for 28 days, and kidney tissues were harvested for comprehensive lipidomic profiling. Lipidomic analysis was performed with liquid chromatography–tandem mass spectrometry (p < 0.05, n = 5/group). Triacylglycerols (TGs) were the predominant lipid class identified. TAC-treated mice exhibited reduced levels of unsaturated TG species with low carbon numbers, whereas TGs with higher carbon numbers and various degrees of unsaturation were increased. All detected TGs containing docosahexaenoic acid (DHA) showed an increasing trend in TAC-treated kidneys. Although accumulation of polyunsaturated TGs has been previously observed in chronic kidney disease, the preferential increase in DHA-containing TGs appears to be a unique feature of TAC-induced nephrotoxicity. These results suggest that DHA-enriched TGs may serve as a metabolic signature of TAC nephrotoxicity and offer new insights into its pathophysiology. Full article