Search Results (148)

Background and Objectives: Cancer cachexia is a debilitating metabolic syndrome highly prevalent in colorectal cancer (CRC), characterized by progressive skeletal muscle wasting. The myostatin–FOXO signaling pathway contributes to this process by activating the E3 ubiquitin ligases MuRF-1 and Atrogin-1. Exercise is a promising non-pharmacological strategy, but its effects on this pathway in CRC cachexia remain unclear. This review aimed to synthesize preclinical evidence on the impact of exercise on the myostatin–FOXO axis. Materials and Methods: A comprehensive search was performed in PubMed/MEDLINE, Scopus, Web of Science, and Science Direct from inception through August 2025. Eligible studies included murine CRC models (C26 or Apc^Min/+) exposed to aerobic, resistance, or combined exercise interventions, with outcomes assessing myostatin, FOXO, MuRF-1, or Atrogin-1. Study quality was appraised using the CAMARADES 10-item checklist. Results: eleven studies met the criteria, with quality scores ranging from 6 to 8. Aerobic exercise, particularly voluntary wheel running, most consistently reduced MuRF-1 expression and systemic inflammation, whereas resistance and eccentric training exerted stronger inhibitory effects on FOXO and Atrogin-1. Myostatin was directly measured in two studies, yielding inconsistent results. Resistance and eccentric training promoted anabolic signaling (e.g., mTORC1), whereas aerobic protocols improved oxidative capacity. Variability in exercise type, intensity, and duration contributed to heterogeneity across findings. Conclusions: Exercise attenuates skeletal muscle catabolism in CRC-induced cachexia, mainly through modulation of the myostatin–FOXO pathway and downstream ligases. However, limited direct data on myostatin and methodological heterogeneity underscore the need for standardized protocols and translational studies. This review provides the first focused synthesis of exercise-mediated regulation of this pathway in CRC cachexia. Full article

Disuse-induced muscle atrophy (DMA), commonly resulting from immobilization, is driven by chronic inflammation and oxidative stress, which disrupts the balance between protein synthesis and degradation. Quinic acid (QA), a natural compound with known antioxidant and anti-inflammatory properties, was investigated for its potential to counteract muscle atrophy. Using a DMA-induced immobilization model in male C57BL/6N (8 weeks) mice, we found that oral QA administration significantly restored the weight and cross-sectional area of atrophic muscles and improved muscle function, as measured by grip strength and treadmill performance. QA also reduced the expression of pro-inflammatory cytokines (Tnf, Il6, and Myostatin) and E3 ubiquitin ligases (Trim63 and Fbxo32), while increasing antioxidant enzyme levels and serum IL-15 in DMA. In tumor necrosis factor-α-stimulated L6 myotubes, QA reversed inflammation- and oxidative stress-induced gene changes, suppressed NF-ĸB activation, and downregulated protein degradation pathways mediated by FoxO3α. Furthermore, QA restored the expression of myogenesis-related genes and reactivated PI3K/Akt and mTOR/p70S6K/4EBP1 signaling pathways, enhancing protein synthesis. Collectively, our findings demonstrate that QA mitigates immobilization-induced muscle atrophy by modulating inflammation, oxidative stress, and key anabolic and catabolic signaling pathways. These results suggest that QA is a promising functional compound for preserving skeletal muscle health under conditions of disuse. Full article

Insulin is a key anabolic hormone traditionally considered to be exclusively produced by pancreatic β-cells. Insulin exerts several systemic effects involved in glucose uptake and metabolism. In the retina, insulin signaling acts as a regulator of photoreceptor- retinal pigment epithelium (RPE) metabolic coupling as well as of neuronal survival via the PI3K/Akt and MAPK/ERK pathways. Impaired insulin signaling contributes to diabetic retinopathy, retinitis pigmentosa, and age-related degeneration by disrupting energy homeostasis and trophic support. However, growing evidence suggests that the retina, particularly RPE, locally synthesizes and secretes insulin. Although the role of local insulin production in the retina remains to be clarified, this discovery introduces a paradigm shift in retinal physiology, suggesting a self-sustaining insulin signaling system that supports glucose uptake, lipid metabolism, and neurovascular integrity. Emerging data indicate that RPE-derived insulin is stimulated by photoreceptor outer segment (POS) phagocytosis and may act through autocrine and paracrine mechanisms to maintain retinal function, even under conditions of systemic insulin deficiency. Understanding this extra-pancreatic insulin source opens new therapeutic perspectives aimed at enhancing local insulin signaling to preserve vision and prevent retinal degeneration. Thus, the objective of this review is to summarize current evidence on RPE-derived insulin and to discuss its potential implications for retinal homeostasis and disease. Full article

Glucocorticoid therapy, using agents like dexamethasone (Dexa), often leads to muscle atrophy by increasing protein degradation via the ubiquitin–proteasome system while suppressing protein synthesis. Stigmasterol, a phytosterol with known bioactivities, has an unexplored role in muscle atrophy. This study investigated stigmasterol’s protective effects against Dexa-induced muscle atrophy and its impact on the FoxO3 and mTORC1 signaling pathways. Differentiated C2C12 myotubes were treated with Dexa (50 µM) ± stigmasterol (10 µM), and the morphology, viability, and protein levels in the FoxO3/MuRF1/MAFbx catabolic and mTOR/p70S6K/4E-BP1 anabolic signaling pathways were assessed. C57BL/6 mice received Dexa (20 mg/kg/day i.p.) ± stigmasterol (3 mg/kg/day oral) for 21 days, and the body/muscle mass, bone mineral density (BMD), fiber cross-sectional area (CSA), and muscle protein expression were measured. Stigmasterol (10 µM) was non-toxic and attenuated Dexa-induced reductions in myotube diameter and fusion in vitro, concurrent with suppressing Dexa-induced upregulation of FoxO3/MuRF1/MAFbx proteins and preventing the Dexa-induced dephosphorylation of mTOR/p70S6K/4E-BP1 proteins. In vivo, stigmasterol mitigated Dexa-induced losses in body weight, muscle mass, BMD, and fiber CSA. This protection was associated with attenuated upregulation of FoxO3 and MAFbx proteins in muscle tissue. Stigmasterol protected against Dexa-induced muscle atrophy in vitro and in vivo via modulation of the FoxO3–MAFbx catabolic pathway. These findings suggest stigmasterol inhibits excessive glucocorticoid-induced muscle protein breakdown. It therefore warrants further investigation as a potential therapeutic agent for glucocorticoid myopathy. Full article

Background: Skeletal muscle is essential not only for structural integrity but also metabolic homeostasis. Muscle atrophy, the loss of muscle mass and function, is closely linked to chronic and metabolic disorders and is driven by chronic inflammation, oxidative stress, impaired myogenesis, and disrupted protein homeostasis. The present study aimed to evaluate the protective effects and underlying mechanisms of Rosa canina extract (RCE), a polyphenol-rich plant known for its antioxidant and anti-inflammatory properties, in vitro and in vivo models of muscle atrophy. Methods: We investigated the effects of RCE in TNF-α-treated L6 myotubes and a mouse model (eight-week-old male C57BL/6N) of immobilization-induced muscle atrophy. Markers of inflammation, oxidative stress, myogenesis, protein turnover, and anabolic signaling were analyzed via RT-PCR, Western blotting and ELISA. Muscle mass, performance, micro-CT imaging, and histological cross-sectional area were assessed in vivo. Results: RCE suppressed pro-inflammatory cytokines, restored antioxidant enzyme expression, and preserved myogenic markers. It inhibited muscle proteolysis by downregulating the genes involved in protein degradation and promoted protein synthesis by via activation of the PI3K/Akt/mTOR pathway. In mice, RCE mitigated muscle mass loss, preserved fiber cross-sectional area, improved strength and endurance, and restored muscle volume. Conclusions: RCE attenuated muscle atrophy by targeting inflammation, oxidative stress, proteolysis, and impaired anabolism. These findings highlight RCE as a promising natural therapeutic for preserving muscle health and metabolic homeostasis. Full article

Skeletal muscle is increasingly recognized as a dynamic endocrine organ whose secretome—particularly myokines—serves as a central hub for the coordination of systemic metabolic health, inflammation, and tissue adaptation. This review integrates molecular, cellular, and physiological evidence to elucidate how myokine signaling translates mechanical and metabolic stimuli from exercise into biochemical pathways that regulate glucose homeostasis, lipid oxidation, mitochondrial function, and immune modulation. We detail the duality and context-dependence of cytokine and myokine actions, emphasizing the roles of key mediators such as IL-6, irisin, SPARC, FGF21, and BAIBA in orchestrating cross-talk between muscle, adipose tissue, pancreas, liver, bone, and brain. Distinctions between resistance and endurance training are explored, highlighting how each modality shapes the myokine milieu and downstream metabolic outcomes through differential activation of AMPK, mTOR, and PGC-1α axes. The review further addresses the hormetic role of reactive oxygen species, the importance of satellite cell dynamics, and the interplay between anabolic and catabolic signaling in muscle quality control and longevity. We discuss the clinical implications of these findings for metabolic syndrome, sarcopenia, and age-related disease, and propose that the remarkable plasticity of skeletal muscle and its secretome offers a powerful, multifaceted target for lifestyle interventions and future therapeutic strategies. An original infographic is presented to visually synthesize the complex network of myokine-mediated muscle–organ interactions underpinning exercise-induced metabolic health. Full article

Sleep is a fundamental biological process in athletes, indispensable for tissue regeneration, exercise adaptation, and injury prevention. Disruptions in sleep architecture and duration have been consistently associated with diminished physical performance and adverse health outcomes, impairing muscular strength, power output, and endurance capacity, and concurrently compromising cognitive function. On a physiological level, insufficient sleep disrupts endocrine homeostasis, elevating cortisol levels and reducing anabolic hormones such as testosterone and growth hormone. At the molecular level, sleep loss promotes the upregulation of pro-apoptotic gene expression and exacerbates pro-inflammatory signalling pathways. Optimal sleep duration and quality represent a critical “regenerative window”, essential for enhancing athletic performance and safeguarding physiological resilience. Ensuring adequate sleep among athletes can be effectively achieved through educational, behavioural, and nutritional interventions outlined in this review. Full article

Osteoarthritis (OA) lacks disease-modifying therapies, in part because key features of the joint microenvironment remain underappreciated. One such feature is localized acidosis, characterized by sustained reductions in extracellular pH within the cartilage, meniscus, and the osteochondral interface despite near-neutral bulk synovial fluid. We synthesize current evidence on the origins, sensing, and consequences of joint acidosis in OA. Metabolic drivers include hypoxia-biased glycolysis in avascular cartilage, cytokine-driven reprogramming in the synovium, and limits in proton/lactate extrusion (e.g., monocarboxylate transporters (MCTs)), with additional contributions from fixed-charge matrix chemistry and osteoclast-mediated acidification at the osteochondral junction. Acidic niches shift proteolysis toward cathepsins, suppress anabolic control, and trigger chondrocyte stress responses (calcium overload, autophagy, senescence, apoptosis). In the nociceptive axis, protons engage ASIC3 and sensitize TRPV1, linking acidity to pain. Joint cells detect pH through two complementary sensor classes: proton-sensing GPCRs (GPR4, GPR65/TDAG8, GPR68/OGR1, GPR132/G2A), which couple to G_s, G_q/11, and G_12/13 pathways converging on MAPK, NF-κB, CREB, and RhoA/ROCK; and proton-gated ion channels (ASIC1a/3, TRPV1), which convert acidity into electrical and Ca²⁺ signals. Therapeutic implications include inhibition of acid-enabled proteases (e.g., cathepsin K), pharmacologic modulation of pH-sensing receptors (with emerging interest in GPR68 and GPR4), ASIC/TRPV1-targeted analgesia, metabolic control of lactate generation, and pH-responsive intra-articular delivery systems. We outline research priorities for pH-aware clinical phenotyping and imaging, cell-type-resolved signaling maps, and targeted interventions in ‘acidotic OA’ endotypes. Framing acidosis as an actionable component of OA pathogenesis provides a coherent basis for mechanism-anchored, locality-specific disease modification. Full article

Starvation in horses presents critical welfare, economic, and management challenges with underlying molecular mechanisms of metabolic modification and recovery left poorly defined. Prolonged caloric deprivation induces significant systemic shifts in carbohydrate, protein, and lipid metabolism, reflected in coordinated changes in tissue-specific gene expression. This review synthesizes current knowledge on equine metabolic responses to starvation, emphasizing pathways found through RNA sequencing (RNA-seq) and real-time quantitative polymerase chain reaction (RT-qPCR) studies. Molecular investigations using RNA-seq and RT-qPCR have provided insight into transcriptional reprogramming during starvation and subsequent refeeding. Shifts in gene expression reflect the metabolic transition from carbohydrate dependence to lipid use, suppression of anabolic signaling, and activation of proteolytic pathways. However, interpretation of these data requires caution, as factors such as post-mortem interval, tissue handling, and euthanasia methods particularly the use of sodium barbiturates can influence transcript stability and abundance, potentially confounding results. The literature shows that starvation-induced molecular changes are not uniform across tissues, with skeletal muscle, liver, and adipose tissue showing distinct transcriptional signatures and variable recovery patterns during refeeding. Cross-species comparisons with hibernation, caloric restriction, and cachexia models provide context for understanding these changes, though equine-specific studies remain limited. Identified gaps include the scarcity of longitudinal data, inconsistent tissue sampling protocols, and lack of standardized reference genes for transcriptomic analyses in horses. Addressing these limitations will improve the accuracy of molecular evaluations and enhance our ability to predict recovery trajectories. A more comprehensive understanding of systemic and tissue-specific responses to starvation will inform evidence-based rehabilitation strategies, reduce the risk of refeeding syndrome, and improve survival and welfare outcomes for affected horses. Full article

This study investigated the effects of dietary supplementation with varying levels (CK: 0.0 g/kg; RL: 0.1 g/kg; RM: 1.0 g/kg; RH: 10.0 g/kg) of Rhodotorula mucilaginosa on muscle composition, serum biochemical indicators, antioxidant capacity, lipid metabolism, and the mTOR signaling pathway in red claw crayfish (Cherax quadricarinatus). Results showed that, compared to CK, treatment groups had higher muscle crude protein, fat, leucine, histidine, arginine, and essential amino acids (p < 0.05), and lower saturated fatty acids (p < 0.05). Treatment groups also exhibited increased activities of alkaline phosphatase, acid phosphatase, superoxide dismutase, catalase, glutathione S-transferase, lysozyme, albumin, total protein, and antioxidant capacity (p < 0.05), with reduced activities of aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, and triglycerides (p < 0.05). In the hepatopancreas, treatment groups showed significant downregulation of AMP-activated protein kinase α, β, and γ, and carnitine palmitoyltransferase 1 genes (p < 0.05). Conversely, genes involved in lipid anabolism (peroxisome proliferator-activated receptor γ, acetyl-CoA carboxylase, fatty acid synthase, sterol regulatory element-binding protein, protein kinase B, and mammalian target of rapamycin 1 and 2) were upregulated (p < 0.05). In conclusion, R. mucilaginosa supplementation affects muscle composition, lipid metabolism, and mTOR signaling. The optimal dose is 1.0 g/kg. Full article

Cancer-associated cachexia is a multifaceted wasting syndrome characterized by progressive loss of skeletal muscle mass, systemic inflammation, and metabolic dysfunction and is particularly prevalent in gastrointestinal cancers. Physical activity has emerged as a promising non-pharmacological intervention capable of attenuating key drivers of cachexia. Exercise modulates inflammatory signaling (e.g., IL-6/STAT3 and TNF-α/NF-κB), enhances anabolic pathways (e.g., IGF-1/Akt/mTOR), and preserves lean body mass and functional capacity. Exercise-induced signaling molecules, known as exerkines, are key mediators of these benefits, which are released during physical activity and act in an autocrine, paracrine, and endocrine manner. However, many of these molecules also exhibit context-dependent effects. While they exert protective, anti-inflammatory, or anabolic actions when transiently elevated after exercise, the same molecules may contribute to cachexia pathogenesis when chronically secreted by tumors or in systemic disease states. The biological effects of a given factor depend on its origin, timing, concentration, and physiological milieu. This review presents recent evidence from clinical and experimental studies to elucidate how physical activity and exerkines may be harnessed to mitigate cancer cachexia, with particular emphasis on gastrointestinal malignancies and their unique metabolic challenges. Full article

Background/Objectives: The Fanconi anemia (FA) pathway is essential for the repair of DNA interstrand crosslinks and maintenance of genomic stability. Germline loss of FA pathway function in the inherited Fanconi anemia syndrome leads to increased DNA damage and a range of clinical phenotypes, including a heightened risk of head and neck squamous cell carcinoma (HNSCC). Non-synonymous FA gene mutations are also observed in up to 20% of sporadic HNSCCs. The mechanistic target of rapamycin (mTOR) is known to stimulate cell growth, anabolic metabolism including protein synthesis, and survival following genotoxic stress. Methods/Results: Here, we demonstrate that FA− deficient (FA−) HNSCC cells exhibit elevated intracellular amino acid levels, increased total protein content, and an increase in protein synthesis indicative of enhanced translation. These changes are accompanied by hyperactivation of the mTOR effectors translation initiation factor 4E Binding Protein 1 (4E-BP1) and ribosomal protein S6. Treatment with the mTOR inhibitor rapamycin reduced the phosphorylation of these targets and blocked translation specifically in FA− cells but not in their isogenic FA− proficient (FA+) counterparts. Rapamycin-mediated mTOR inhibition sensitized FA− but not FA+ cells to rapamycin under nutrient stress, supporting a therapeutic metabolism-based vulnerability in FA− cancer cells. Conclusions: These findings uncover a novel role for the FA pathway in suppressing mTOR signaling and identify mTOR inhibition as a potential strategy for targeting FA− HNSCCs. Full article

Yam (Dioscorea opposita) tuber development is a complex process regulated by various phytohormones, with gibberellin (GA) playing a crucial role. However, the underlying mechanisms and interaction of GA with other phytohormone pathways on yam tuber development remain incompletely understood. This study investigated the regulatory role of GA and its crosstalk with other phytohormones during yam tuber growth through phenotypic, cytological, physiological, and transcriptomic as well as targeted phytohormone metabolomics analyses. The results reveal that exogenous GA promoted tuber enlargement increases vascular bundle and the number and diameter of sieve tubes, and alters the expression of GA anabolism genes and GA signal transduction pathways. Integrated transcriptome and targeted metabolomics analyses revealed coordinated changes in GA and ethylene (ETH) biosynthesis and signaling pathways during tuber development, particularly DELLA-GAI2 acting as a negative regulator of GA signaling. Overexpression of DoDELLA-GAI2 in transgenic tobacco significantly reduced GA level, starch, cytokinin (CTK), and ETH content, as well as aerenchyma tissue growth and parenchyma cell size. Exogenous GA and ethephon treatments increased GA, starch, CTK, and ETH content, and downregulated DoDELLA-GAI2 gene expression. The yeast two-hybrid and bimolecular fluorescence complementation (BiFC) assays confirmed a direct interaction between DoDELLA-GAI2 and DoMTCPB, an upstream gene-encoding key enzyme in ETH biosynthesis. DoDELLA-GAI2 acts as a negative regulator of ETH synthesis by interacting with DoMTCPB. GA-induced degradation of DoDELLA-GAI2 relieves this inhibition, promoting ETH production and contributing to tuber growth. Taken together, our findings reveal a novel mechanism based on DoDELLA-GAI2 integrating the GA and ETH signaling processes to regulate tuber development in D. opposita, offering a potential target for improving yam crop productivity. Full article

Osteoarthritis (OA) remains a leading cause of disability worldwide, with no disease-modifying therapies currently available for treatment. The infrapatellar fat pad (IFP) harbors mesenchymal stem/stromal cells (MSC) with potent immunomodulatory and regenerative properties, making them a promising candidate for OA treatment. A growing body of evidence suggests that the therapeutic effects of MSC are largely mediated by their extracellular vesicles (EVs), which carry bioactive cargo that modulates inflammation and tissue repair. However, optimizing MSC-derived EVs as a cell-free therapeutic approach requires an in-depth understanding of how culture conditions and inflammatory/hormonal priming influence their functional properties. In this study, IFP-MSC were expanded in regulatory-compliant human platelet lysate (HPL) and xeno-/serum-free (XFSF) media and primed with an inflammatory/fibrotic cocktail (TIC) with oxytocin (OXT) to assess the impact on their immunophenotypic profile and EV cargo. The immunophenotype confirmed that TIC+OXT-primed MSC retained key immunomodulatory surface markers, while EV characterization verified the successful isolation of CD63+/CD9+ vesicles. Pathway enrichment analysis of both HPL- and XFSF- TIC+OXT EVs cargo identified key miRNAs associated with immune regulation, tissue repair, and anabolic signaling. Functional assays revealed that TIC+OXT EVs promoted M2-like anti-inflammatory macrophage polarization and exhibited chondroprotective properties in chondrocytes/synoviocytes inflammatory osteoarthritic assay. These findings highlight the therapeutic potential of TIC+OXT-primed IFP-MSC-derived EVs as immunomodulatory and chondroprotective agents, offering a promising strategy for OA treatment through a clinically viable, cell-free approach. Full article

Melatonin (MT) is an elicitor that stimulates phenolic compounds biosynthesis and accumulation in fruits and vegetables. However, its role in regulating phenolic compounds and the phenylpropane metabolism during pepper ripening is unclear. To investigate how exogenous MT regulates phenolic compounds biosynthesis during pepper ripening, pepper plant surfaces were sprayed with different MT concentrations (0 and 100 µmol·L⁻¹) 10 days after anthesis. MT treatment improved pepper fruits quality. In particular, total phenolics and flavonoids compounds levels were elevated, indicating that MT affected phenolic compounds metabolism. Furthermore, metabolomics identified 15 substances exhibiting high fold-change values after MT treatment, including chlorogenic acid, gallic acid, ferulic acid, caffeic acid, cynarin, p-coumaric acid, cinnamic acid, gentianic acid, benzoic acid, sinapic acid, p-hydroxybenzoic acid, protocatechuic acid, rutin, quercetin, and kaempferol. Shikimate dehydrogenase, phenylalanine ammonia-lyase, cinnamate-4-hydroxylase, 4-coumarate-Coa ligase, chalcone synthase, and chalcone isomerase activities were also evaluated. MT upregulated the expression of genes involved in phenolic compounds synthesis during pepper ripening and that of corresponding genes involved in the endogenous MT anabolic pathway, promoting endogenous. The polyphenolics and carbohydrates are indicators of the botanical and geographical origin of Serbian autochthonous clones of red spice MT synthesis throughout pepper ripening. In summary, exogenous MT accelerates phenolic compounds synthesis in pepper fruits by activating phenylpropane metabolism and modulating endogenous hormone signaling networks. This is expected to offer a revolutionary strategy to reinforce pepper plants resistance and quality. Full article