Search Results (1,007)

The kallikrein–kinin system and its B1 and B2 receptors are key regulators in metabolic disorders such as obesity, diabetes, and insulin resistance. Obesity, a chronic and multifactorial condition often associated with comorbidities like type 2 diabetes and dyslipidemia, remains poorly understood at the metabolic level. The kinin B2 receptor (B2R) is involved in blood pressure regulation and glucose metabolism, promoting glucose uptake in skeletal muscle via bradykinin. Studies in B2R-KO mice demonstrate that the absence of this receptor predisposes animals to glucose intolerance under a high-fat diet and impairs adaptive thermogenesis, indicating a protective role for B2R in metabolic homeostasis and insulin sensitivity. In contrast, the kinin B1 receptor (B1R) is inducible under pathological conditions and is activated by kinin metabolites. Mouse models lacking B1R exhibit improved metabolic profiles, including protection against high-fat diet-induced obesity and insulin resistance, enhanced energy expenditure, and increased leptin sensitivity. B1R inactivation in adipocytes enhances insulin responsiveness and glucose tolerance, supporting its role in the development of insulin resistance. Moreover, B1R deficiency improves energy metabolism and thermogenic responses to adrenergic and cold stimuli, promoting the activation of brown adipose tissue and the browning of white adipose tissue. Collectively, these findings suggest that B1R and B2R represent promising therapeutic targets for the treatment of metabolic disorders. Full article

Background: Menopause increases the risk of cardiovascular diseases (CVD) accompanied by a decline in muscle function. Myokines, released by skeletal muscle, could play a significant role in cardiovascular health. Objectives and Methods: This study aimed to investigate the changes induced by a 16-week resistance training (RT) program and/or the docosahexaenoic acid (DHA)-rich n-3 PUFA supplementation on myokine and cytokine circulating levels and to study their associations with parameters of body composition, muscle function, and glucose and lipid serum markers in postmenopausal women with overweight/obesity. Results: At baseline, interleukin-6 (IL-6) levels were positively correlated with body fat and with tumor necrosis factor-alpha (TNF-α) levels and negatively associated with meterorin-like (METRNL) levels. Moreover, METRNL was inversely associated with insulin levels and with HOMA-IR. After the intervention, muscle quality improved with either treatment but more notably in response to RT. N-3 supplementation caused significant improvements in cardiometabolic health markers. TNF-α decreased in all experimental groups. Myostatin levels decreased in the RT and in the n-3 groups, and IL-6 increased in the n-3+RT group. Lastly, no interactions between treatments were observed. Conclusions: In postmenopausal women with overweight or obesity, RT could help improve skeletal muscle function, while DHA-rich n-3 supplementation might decrease CVD risk and might potentially improve muscle function. The modulation of myokine levels could be underlying some of the effects of DHA or RT; however, further research is necessary. Full article

Prolactin (PRL) is a hormone primarily associated with lactation, but it plays various roles in both men and women. PRL belongs to the family of peptide hormones, including placental lactogen and growth hormone. Interestingly, PRL is a pleiotropic hormone affecting several physiological and pathological conditions, including fertility. Moreover, several pathophysiological roles have been associated with this hormone, including those of the immune system, autoimmune disorders, asthma, and ageing. Additionally, PRL receptors are ubiquitously expressed in tissues, including the mammary gland, gonads, liver, kidney, adrenal gland, brain, heart, lungs, pituitary gland, uterus, skeletal muscle, skin blood cells, and immune system. Therefore, in the present paper, we cover the potential role that PRL may play in asthma by promoting inflammation and modulating immune responses. The detection of its receptor in lung tissue suggests a direct role in airway smooth muscle contractility through activation of signaling pathways such as JAK2-STAT5, MAPK/ERK1/2, and PI3K/Akt, as well as influencing ionic currents that regulate cell contraction, proliferation, and survival. In this sense, this review aims to explore the potential involvement of PRL in asthma pathophysiology by examining its interactions with intracellular signaling pathways and its possible impact on airway smooth muscle contractility and immune modulation. Full article

Sleep paralysis (SP), an REM parasomnia, can be characterized as one of the symptoms of narcolepsy. The SP phenomenon involves regaining meta-consciousness by the dreamer during REM, when the physiological atonia of skeletal muscles is accompanied by visual and auditory hallucinations that are perceived as vivid and distressing nightmares. Sensory impressions include personification of an unknown presence, strong chest pressure sensation, and intense fear resulting from subjective interaction with the unfolding nightmare. While the mechanism underlying skeletal muscle atonia is known, the physiology of hallucinations remains unclear. Their complex etiology involves interactions among various membrane receptor systems and neurotransmitters, which leads to altered neuronal functionality and disruptions in sensory perception. According to current knowledge, serotonergic activation of 5-hydroxytryptamine-receptor-2A (5-HT2A)-associated pathways plays a critical role in promoting hallucinogenesis during SP. Furthermore, they share similarities with psychedelic-substance-induced ones (i.e., LSD, psilocybin, and 2,5-dimethoxy-4-iodoamphetamine). These compounds also target the 5-HT2A receptor; however, their molecular mechanism varies from serotonin-induced ones. The current review discusses the intracellular signaling pathways responsible for promoting hallucinations in SP, highlighting the critical role of β-arrestin-2. We propose that the β-arrestin-2 signaling pathway does not directly induce hallucinations but creates a state of network susceptibility that facilitates their abrupt emergence in sensory areas. Understanding the molecular basis of serotonergic hallucinations and gaining better insight into 5-HT2A-receptor-dependent pathways may prove crucial in the treatment of multifactorial neuropsychiatric disorders associated with the dysfunctional activity of serotonin receptors. Full article

This study aimed to investigate the effects of augmented reality (AR) treadmill walking training on cognitive function, body composition, physiological responses, and acceptance among older adults. Additionally, it analyzed the relationships between body composition, physiological responses, and the acceptance of AR technology. A randomized controlled trial was conducted, recruiting 60 healthy older adults, who were assigned to either the experimental group (AR treadmill walking training) or the control group (traditional treadmill walking training). The assessments included cognitive function evaluation (stride length, walking speed, and balance test), body composition (BMI, skeletal muscle mass, fat mass, and body fat percentage), and physiological responses (heart rate, calorie expenditure, exercise duration, and distance covered). Furthermore, the AR Acceptance Scale was used to assess perceived ease of use, perceived usefulness, attitudes, and behavioral intentions. The results indicated that AR treadmill walking training had significant positive effects on improving cognitive function, optimizing body composition, and enhancing physiological responses among older adults. Compared with the traditional training group, the experimental group demonstrated better performance in stride length, walking speed, and balance tests, with increased skeletal muscle mass and reduced body fat percentage. Additionally, improvements were observed in heart rate regulation, calorie expenditure, exercise duration, and distance covered, reflecting enhanced exercise tolerance. Moreover, older adults exhibited a high level of acceptance toward AR technology, particularly in terms of attitudes and behavioral intentions, as well as perceived usefulness. This study provides empirical support for the application of AR technology in promoting elderly health and suggests that future research should explore personalized adaptation strategies and long-term effects to further expand the potential value of AR technology in elderly exercise. Full article

Hypoxia represents a critical environmental stressor in aquaculture, significantly disrupting aquatic organisms’ physiological homeostasis and thereby constraining the sustainable development of aquaculture industries. To elucidate the mechanisms underlying hypoxia-induced metabolic regulation in aquatic species, this study employed hybrid yellow catfish (Pelteobagrus vachelli ♀ × Leiocassis longirostris ♂) as a model organism to systematically investigate the multidimensional physiological responses in brain, liver, and muscle tissues under hypoxia (0.7 mg/L) and reoxygenation (7.0 mg/L) conditions. Through qRT-PCR and enzymatic activity analyses, we comprehensively assessed molecular alterations associated with oxygen sensing (HIF-1α gene), respiratory metabolism (PFKL, HK1, PK, CS, and LDHA genes and corresponding enzyme activities), oxidative stress (SOD1, SOD2, GSH-PX, and CAT genes, along with LPO, MDA, PCO, T-SOD, GSH-PX, and CAT levels), apoptosis (Caspase-3, Bax/Bcl-2), inflammatory response (IL-1β, IKKβ), and mitochondrial function (COXIV, PGC-1α, ATP5A1). Key findings demonstrated pronounced HIF-1α activation across all examined tissues. Hepatic tissues exhibited adaptive metabolic reprogramming from aerobic to anaerobic metabolism, whereas cerebral tissues displayed suppressed anaerobic glycolysis during prolonged hypoxia, and muscular tissues manifested concurrent inhibition of both glycolytic and aerobic metabolic pathways. Notably, skeletal muscle exhibited marked oxidative stress accompanied by mitochondrial dysfunction, exacerbated inflammation, and apoptosis activation during hypoxia/reoxygenation cycles. This study delineates tissue-specific adaptive mechanisms to hypoxia in yellow catfish, providing theoretical foundations for both piscine hypoxia physiology research and aquaculture practices. Full article

Background and Objectives: Urothelial bladder carcinoma includes a spectrum of malignant lesions with heterogeneous molecular, biological, and clinical features and a variable risk of progression from non-muscle-invasive bladder cancer (NMIBC) to muscle-invasive disease (MIBC) and ultimately to metastatic urothelial carcinoma (mUC). Sarcopenia, a condition secondary to a catabolic state, is characterized by progressive loss of skeletal muscle mass and function and is highly prevalent across all stages of bladder cancer. This review aims to synthesize current evidence regarding the clinical impact of sarcopenia and its dynamic changes throughout the disease course. Materials and Methods: A narrative literature review was conducted using PubMed, Scopus, and Cochrane databases, incorporating the most relevant published sources. Search terms included “bladder carcinoma”, “sarcopenia”, “body composition”, “NMIBC”, and “MIBC”. Case reports and congress abstracts were excluded. Results: In NMIBC treated with intravesical Bacillus Calmette–Guérin (BCG), sarcopenia has been shown to have a negative predictive value in some studies. Among patients receiving neoadjuvant chemotherapy (NAC) for MIBC, sarcopenia has been associated with increased toxicity, dose reductions, and treatment delays. In the context of radical surgery, sarcopenia correlates with increased postoperative mortality and a higher rate of severe complications. In mUC, low muscle mass is a negative prognostic factor regardless of treatment type and is associated with chemotherapy-related hematologic toxicity, although it does not appear to predict immune-related adverse events (irAEs). Conclusions: Sarcopenia is a highly prevalent and clinically relevant phenotype of urothelial bladder cancer patients, impacting prognosis, treatment response, and chemotherapy toxicity. Incorporating sarcopenia with other relevant components of body composition (BC) and systemic inflammatory markers may facilitate the development of more robust risk scores. Current evidence is primarily limited by the retrospective design of most studies. Future prospective research is needed to clarify the prognostic role of sarcopenia and support its integration into routine clinical decision-making. Full article

Background: Aerobic exercise induces a range of complex molecular adaptations in skeletal muscle. However, a complete understanding of the specific transcriptional changes following exercise warrants further research. Methods: This study aimed to identify gene expression patterns following acute aerobic exercise by analyzing Gene Expression Omnibus (GEO) datasets. We performed a comparative analysis of transcriptional profiles of related genes in two independent studies, focusing on both established and novel genes involved in muscle physiology. Results: Our analysis revealed ten consistently upregulated and eight downregulated genes across both datasets. The upregulated genes were predominantly associated with mitochondrial function and cellular respiration, including MDH1, ATP5MC1, ATP5IB, and ATP5F1A. Conversely, downregulated genes such as YTHDC1, CDK5RAP2, and PALS2 were implicated in vascular structure and cellular organization. Importantly, our findings also revealed novel exercise-responsive genes not previously characterized in this context. Among these, MRPL41 and VEGF were significantly upregulated and are associated with p53-mediated apoptotic signaling and fatty acid metabolism, respectively. Novel downregulated genes included LIMCH1, CMYA5, and FOXJ3, which are putatively involved in cytoskeletal dynamics and muscle fiber type specification. Conclusions: These findings enhance our understanding of the transcriptional landscape of skeletal muscle following acute aerobic exercise and identify novel molecular targets for further investigation in the fields of exercise physiology and metabolic health. Full article

Medical phantoms are essential to imaging calibration, clinician training, and the validation of therapeutic procedures. However, most ultrasound phantoms prioritize acoustic realism while neglecting the viscoelastic and anisotropic properties of fibrous soft tissues. This gap limits their effectiveness in modeling realistic biomechanical behavior, especially in wave-based diagnostics and therapeutic ultrasound. Current materials like gelatine and agarose fall short in reproducing the complex interplay between the solid and fluid components found in biological tissues. To address this, we developed a soft, anisotropic composite whose dynamic mechanical properties resemble fibrous biological tissues such as skin and skeletal muscle. This material enables wave propagation and vibration studies in controllably anisotropic media, which are rare and highly valuable. We demonstrate the tunability of damping and stiffness aligned with fiber orientation, providing a versatile platform for modeling soft-tissue dynamics and validating biomechanical simulations. The phantoms achieved Young’s moduli of 7.16–11.04 MPa for skin and 0.494–1.743 MPa for muscles, shear wave speeds of 1.51–5.93 m/s, longitudinal wave speeds of 1086–1127 m/s, and sound absorption coefficients of 0.13–0.76 dB/cm/MHz, with storage, loss, and complex moduli reaching 1.035–6.652 kPa, 0.1831–0.8546 kPa, and 2.138–10.82 kPa. These values reveal anisotropic response patterns analogous to native tissues. This novel natural fibrous composite system affords sustainable, low-cost ultrasound phantoms that support both mechanical fidelity and acoustic realism. Our approach offers a route to next-gen tissue-mimicking phantoms for elastography, wave propagation studies, and dynamic calibration across diverse clinical and research applications. Full article

Previous research has demonstrated sex-specific differences in muscle cells regarding sex hormone release and steroidogenic enzyme expression after testosterone exposure. The present study aims to elucidate sex-related differences in intracellular processes involved in myogenesis and regeneration. Neonatal 46XX and 46XY human primary skeletal muscle cells were treated with increasing doses of testosterone (0.5, 2, 5, 10, 32, and 100 nM) for 24 h. The molecular pathways involved in muscle metabolism and growth, as well as the release of myokines involved in satellite cell activation, were analyzed using western blot, real-time PCR, and a Luminex assay. The unpaired Student’s t-test and one-way ANOVA for repeated measures were used to determine significant variations within and between groups. An increase in the expression and release of MYF6, IGF-I, IGF-II, and CXCL1, as well as a decrease in GM-CSF, IL-9, and IL-12, was observed in 46XX cells. Conversely, testosterone up-regulated GM-CSF and CXCL1 in 46XY cells but did not affect the release of the other myokines. Preferential activation of the MAPK pathway was observed in 46XX cells, while the PI3K/AKT pathway was preferentially activated in 46XY cells. In conclusion, our findings demonstrate differential responses to androgen exposure in 46XX and 46XY cells, resulting in the activation of muscle cell growth and energy metabolic pathways in a sex-specific manner. Full article

The ergogenic effects of music have been well described across various modes of exercise with widespread use across competitive athletes and recreational exercisers alike. Underlying the acute beneficial effects of music during exercise are profound physiological and psychological changes which involve an array of different organ systems, including but not limited to cardiovascular, endocrine, skeletal muscle, and nervous systems. While the use of music to enhance physical performance and improve associated mechanisms has been largely optimized in healthy individuals, the investigations of the translation to individuals with neurological conditions are still ongoing. Recently, it has been established that the personalization of music interventions greatly influences performance-enhancing benefits and aids in physical performance optimization in healthy individuals. Self-selected music (SSM) has been documented to impart ergogenic advantages over pre-determined or non-preferred music, including improved cardiorespiratory endurance, power development, and velocity of movement which are characterized by adaptative physiological and psychological changes. Evidence of the benefits of SSM has progressed to the degree to which the overlap of possible benefits between healthy and clinical populations is becoming more apparent. This aim of this theoretical review is to discuss how personalized music influences psychophysiological determinants of exercise ability in healthy individuals and consider how these findings may be applicable to neurological conditions to enhance exercise capacity. The current knowledge on the role of SSM in augmenting physiological and psychological responses to exercise in healthy individuals is presented along with how these mechanisms might be leveraged to overcome exercise limitations in neurological conditions. Overall, SSM appears to have theoretical support to be a promising therapeutic approach to improving exercise ability in neurological conditions through similar ergogenic mechanisms documented in healthy individuals, but further investigation is warranted. Full article

Background/Objectives: To investigate associations between Follistatin (FST) gene polymorphisms (SNPs) and baseline musculoskeletal traits, and their interactions with 16-week exercise interventions. Methods: A cohort of 470 untrained Northern Han Chinese adults (208 males, 262 females), sourced from the “Research on Key Technologies for an Exercise and Fitness Expert Guidance System” project, was analyzed. These participants were previously randomly assigned to one of four exercise groups (Hill, Running, Cycling, Combined) or a non-exercising Control group, and completed their respective 16-week protocols. Body composition, bone mineral content (BMC), bone mineral density (BMD), and serum follistatin levels were all assessed pre- and post-intervention. Dual-energy X-ray absorptiometry (DXA) was utilized for the body composition, BMC, and BMD measurements. FST SNPs (rs3797296, rs3797297) were genotyped using matrix assisted laser desorption/ionization time-of-flight mass spectrometer (MALDI-TOF MS) or microarrays. To elucidate the biological mechanisms, we performed in silico functional analyses for rs3797296 and rs3797297. Results: Baseline: In females only, the rs3797297 T allele was associated with higher muscle mass (β = 1.159, 95% confidence interval (CI): 0.202–2.116, P_{_adj} = 0.034) and BMC (β = 0.127, 95% CI: 0.039–0.215, P_{_adj} = 0.009), with the BMC effect significantly mediated by muscle mass. Exercise Response: Interventions improved body composition, particularly in females. Gene-Exercise Interaction: A significant interaction occurred exclusively in women undertaking hill climbing: the rs3797296 G allele was associated with attenuated muscle mass gains (β = −1.126 kg, 95% CI: −1.767 to −0.485, P_{_adj} = 0.034). Baseline follistatin correlated with body composition (stronger in males) and increased post-exercise (primarily in males, Hill/Running groups) but did not mediate SNP effects on exercise adaptation. Functional annotation revealed that rs3797297 is a likely causal variant, acting as a skeletal muscle eQTL for the mitochondrial gene NDUFS4, suggesting a mechanism involving muscle bioenergetics. Conclusions: Findings indicate that FST polymorphisms associate with musculoskeletal traits in Northern Han Chinese. Mechanistic insights from functional annotation reveal potential pathways for these associations, highlighting the potential utility of these genetic markers for optimizing training program design. Full article

This study evaluates the effects of dietary lipid levels on growth performance, hematological health, and muscle composition of juvenile Arapaima gigas. We tested five isonitrogenous diets (451.7 g kg⁻¹ of crude protein) with increasing lipid levels (6%, 10%, 14%, 18%, and 22%). A total of 600 juvenile A. gigas (80.0 ± 10.5 g; 21.8 ± 1.0 cm) were distributed into 20 tanks (500 L; n = 4; 30 fish per tank) in an indoor open system. The fish were fed to apparent satiety four times daily for 60 days. As dietary lipid levels increased, all growth parameters and lipid content in both the whole body and muscle declined. The diet containing 6% lipids resulted in the maximum final weight, weight gain, feed intake, and the lowest feed conversion rate. However, a maximum lipid level of up to 10.26%, with a gross energy-to-protein ratio of 10.15 kcal g⁻¹ in the diet, as determined through polynomial regression analysis, can be used for juvenile A. gigas without significantly affecting weight gain. Diets with high lipid content (18% and 22% lipids) resulted in the lowest survival rates, highest feed conversion rates, lowest condition factor, visible skeletal protrusions, scale depigmentation, and impaired blood biochemistry. The content of eicosapentaenoic acid, docosahexaenoic acid, n-3, and the n-3:n-6 ratio increased in the muscle lipid fraction (mg g⁻¹ of total lipids) in response to higher dietary lipid levels; however, this does not represent an overall improvement in the meat quality, since the total lipid content in the muscle (g of lipid per 100 g of muscle) was reduced due to impaired growth in fish fed high-lipid diets. Notably, the experimental diets also differed in fatty acid composition, which may have influenced some of the physiological and compositional responses observed. Diets with 6% lipids are recommended to provide optimal growth performance, and a maximum dietary lipid level of up to 10.26% is advised to ensure successful A. gigas farming without impairing weight gain. Full article

Elite soccer places significant neuromuscular and metabolic stress on athletes, leading to elevated production of reactive oxygen and nitrogen species (RONS), particularly in skeletal muscle, where intense contractile activity and increased oxygen flux drive oxidative processes. These reactive species play a dual role in skeletal muscle, supporting adaptive signaling at controlled levels while causing oxidative damage when poorly regulated. This paper presents an integrated synthesis of current knowledge on redox biology in elite soccer players, focusing on the origins and regulation of RONS, the functions of enzymatic and non-enzymatic antioxidant systems, and how both RONS and antioxidant responses influence muscle performance, fatigue, recovery, and long-term physiological adaptation. Drawing on studies conducted between 2000 and 2025, the discussion underscores the seasonal fluctuations in oxidative stress, individual variability in redox responses, and the potential adverse effects of unsystematic antioxidant supplementation. The analysis also emphasizes the value of using biomarker-guided, periodized antioxidant interventions tailored to training demands. Future directions include longitudinal tracking and the use of AI-assisted monitoring to enable personalized strategies for maintaining redox balance and optimizing performance in elite sport. Full article

Background: Under oxidative stress conditions, the increased levels of reactive oxygen species (ROS) within cells disrupt the intracellular homeostasis. Tartary buckwheat peptides exert their effects by scavenging oxidative free radicals, such as superoxide anion and hydrogen peroxide, thereby reducing oxidative damage within cells. Meanwhile, these peptides safeguard mitochondria by maintaining the mitochondrial membrane potential, decreasing the production of mitochondrial oxygen free radicals, and regulating mitochondrial biogenesis and autophagy to preserve mitochondrial homeostasis. Through these mechanisms, Tartary buckwheat peptides restore the intracellular redox balance, sustain cellular energy metabolism and biosynthesis, and ensure normal cellular physiological functions, which is of great significance for cell survival and adaptation under oxidative stress conditions. Objectives: In this experiment, a classical cellular oxidative stress model was established. Indicators related to antioxidant capacity and mitochondrial membrane potential changes, as well as pathways associated with oxidative stress, were selected for detection. The aim was to elucidate the effects of Tartary buckwheat oligopeptides on the metabolism of cells in response to oxidative stress. Methods: In this study, we established an oxidative damage model of mouse skeletal muscle myoblast (SOL8) cells using hydrogen peroxide (H₂O₂), investigated the pre-protective effects of Tartary buckwheat oligopeptides on H₂O₂-induced oxidative stress damage in SOL8 cells at the cellular level, and explored the possible mechanisms. The CCK-8 method is a colorimetric assay based on WST-8-[2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, monosodiumsalt], which is used to detect cell proliferation and cytotoxicity. Results: The value of CCK-8 showed that, when the cells were exposed to 0.01 mmol/L H₂O₂ for 1 h and 10 mg/mL Tartary buckwheat oligopeptides intervention for 48 h, these were the optimal conditions. Compared with the H₂O₂ group, the intervention group (KB/H₂O₂ group) showed that the production of ROS was significantly reduced (p < 0.001), the malondialdehyde (MDA) content was significantly decreased (p < 0.05), and the activity of catalase (CAT) was significantly increased (p < 0.01); the mitochondrial membrane potential in the KB/H₂O₂ group tended to return to the level of the control group, and they all showed dose-dependent effects. Compared with the H₂O₂ group, the mRNA expression of KEAP1 in the KB/H₂O₂ group decreased, while the mRNA expression of NRF2α, HO-1, nrf1, PGC-1, P62, and PINK increased. Conclusions: Therefore, Tartary buckwheat oligopeptides have a significant pre-protective effect on H₂O₂-induced SOL8 cells, possibly by enhancing the activity of superoxide dismutase, reducing ROS attack, balancing mitochondrial membrane potential, and maintaining intracellular homeostasis. Full article