Search Results (315)

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

Aim: Pacifiers play a critical role in the early stages of craniofacial and palate development during infancy. While they provide comfort and aid in soothing, their use can also have significant impacts on the growth and function of the oral cavity. This study aimed to simulate and predict the behavior of six different types of pacifiers and their functional interaction with the tongue and palate, with the goal of understanding their potential effects on orofacial growth and development. Materials and Methods: Biomechanical analysis using Finite Element Analysis (FEA) mathematical models was employed to evaluate the behavior of six different commercial pacifiers in contact with the palate and tongue. Three-dimensional solid models of the palate and tongue were based on the mathematical framework from a 2007 publication. This allowed for a detailed investigation into how various pacifier designs interact with soft and hard oral tissues, particularly the implications on dental and skeletal development. Results: The findings of this study demonstrate that pacifiers exhibit different interactions with the oral cavity depending on their geometry. Anatomical–functional pacifiers, for instance, tend to exert lateral compressions near the palatine vault, which can influence the hard palate and contribute to changes in craniofacial growth. In contrast, other pacifiers apply compressive forces primarily in the anterior region of the palate, particularly in the premaxilla area. Furthermore, the deformation of the tongue varied significantly across different pacifier types: while some pacifiers caused the tongue to flatten, others allowed it to adapt more favorably by assuming a concave shape. These variations highlight the importance of selecting a pacifier that aligns with the natural development of both soft and hard oral tissues. Conclusions: The results of this study underscore the crucial role of pacifier geometry in shaping both the palate and the tongue. These findings suggest that pacifiers have a significant influence not only on facial bone growth but also on the stimulation of oral functions such as suction and feeding. The geometry of the pacifier affects the soft tissues (tongue and muscles) and hard tissues (palate and jaw) differently, which emphasizes the need for careful selection of pacifiers during infancy. Choosing the right pacifier is essential to avoid potential negative effects on craniofacial development and to ensure that the benefits of proper oral function are maintained. Therefore, healthcare professionals and parents should consider these biomechanical factors when introducing pacifiers to newborns. Full article

Laboratory-based assessment of cardiorespiratory function is a widely applied method in sports science. Most performance evaluations focus on oxygen uptake parameters. Despite the well-established concept of oxygen deficit introduced by Hill in the 1920s, relatively few studies have examined its behavior during submaximal exercise, with limited exploration of deficit dynamics. The present study aimed to analyze the behavior of oxygen deficit in young female handball players (N = 42, age: 15.4 ± 1.3 years) during graded exercise. Oxygen deficit was estimated using the American College of Sports Medicine (ACSM) algorithm, restricted to subanaerobic threshold segments of a quasi-ramp exercise protocol. Cardiorespiratory parameters were measured with the spiroergometry test on treadmills, and body composition was assessed via Dual Energy X-ray Absorptiometry (DEXA). Cluster and principal component analyzes revealed two distinct athlete profiles with statistically significant differences in both morphological and physiological traits. Cluster 2 showed significantly higher relative VO₂ peak (51.43 ± 3.70 vs. 45.70 ± 2.87 mL·kg⁻¹·min⁻¹; p < 0.001; Cohen’s d = 1.76), yet also exhibited a greater oxygen deficit per kilogram (39.03 ± 16.71 vs. 32.56 ± 14.33 mL·kg⁻¹; p = 0.018; d = 0.80). Cluster 1 had higher absolute body mass (69.67 ± 8.13 vs. 59.66 ± 6.81 kg; p < 0.001), skeletal muscle mass (p < 0.001), and fat mass (p < 0.001), indicating that body composition strongly influenced oxygen deficit values. The observed differences in oxygen deficit profiles suggest a strong influence of genetic predispositions, particularly in cardiovascular and muscular oxygen utilization capacity. Age also emerged as a critical factor in determining the potential for adaptation. Oxygen deficit during submaximal exercise appears to be a multifactorial phenomenon shaped by structural and physiological traits. While certain influencing factors can be modified through training, others especially those of genetic origin pose inherent limitations. Early development of cardiorespiratory capacity may offer the most effective strategy for long-term optimization. Full article

Glucose-6-phosphate dehydrogenase (G6PD) deficiency, the most common enzymatic disorder, affects over 500 million people worldwide and is often linked to exercise intolerance due to oxidative stress, but its true impact on physical performance remains unclear. This study aimed to evaluate the physiological and metabolic effects of G6PD deficiency on endurance capacity. Using humanized mice carrying the African G6PD variant [V68M; N126D] (hG6PD_A−), we show that despite reduced pentose phosphate pathway activity, these mice exhibit a 10.8% increase in treadmill critical speed (CS)—suggesting enhanced endurance capacity. Multi-omics profiling across red blood cells, plasma, skeletal muscle, spleen, kidney, and liver reveals metabolic adaptations, including elevated glycolysis, fatty acid oxidation, and increased mitochondrial activity, alongside heightened oxidative phosphorylation in muscle and accelerated red blood cell turnover in the spleen and liver. These findings indicate that systemic metabolic reprogramming may offset antioxidant deficiencies, potentially conferring a performance advantage. Given that G6PD deficiency affects up to 13% of African Americans and is associated with cardiovascular health disparities, our results challenge conventional exercise restrictions and highlight the need for personalized exercise guidelines for affected individuals. 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: 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

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: Sarcopenia is a syndrome associated with aging, characterized by a progressive decline in skeletal muscle mass and function. Its onset compromises the health and longevity of older adults by increasing susceptibility to falls, fractures, and various comorbid conditions, thereby diminishing quality of life and capacity for independent living. Accumulating evidence indicates that moderate-intensity aerobic exercise is an effective strategy for promoting overall health in older adults and exerts a beneficial effect that mitigates age-related sarcopenia. However, the underlying molecular mechanisms through which exercise confers these protective effects remain incompletely understood. Methods: In this study, we established a naturally aging mouse model to investigate the effects of a 16-week treadmill-based aerobic exercise regimen on skeletal muscle physiology. Results: Results showed that aerobic exercise mitigated age-related declines in muscle mass and function, enhanced markers associated with protein synthesis, reduced oxidative stress, and modulated the expression of genes and proteins implicated in mitochondrial quality control. Notably, a single session of aerobic exercise acutely elevated circulating levels of β-hydroxybutyrate (β-HB) and upregulated the expression of BDH1, HCAR2, and PPARG in the skeletal muscle, suggesting a possible role of β-HB–related signaling in exercise-induced muscle adaptations. However, although these findings support the beneficial effects of aerobic exercise on skeletal muscle aging, further investigation is warranted to elucidate the causal relationships and to characterize the chronic signaling mechanisms involved. Conclusions: This study offers preliminary insights into how aerobic exercise may modulate mitochondrial quality control and β-HB–associated signaling pathways during aging. 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

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

Background: Physical activity induces a range of physiological and molecular adaptations, particularly affecting skeletal muscle and the cardiovascular system, regulating both tissue architecture and metabolic pathways. Emerging evidence suggests that PIWI-interacting RNAs (piRNAs) may serve as potential biomarkers for these adaptations. Here, we analyzed piRNA patterns in the context of exercise. Methods: This study selected eight participants of the iReAct study (DRKS00017446) for piRNA analysis. Baseline assessments included demographic profiling and fitness evaluation, particularly maximal oxygen uptake (V̇O2max) assessment. In addition, blood samples were collected pre- and (for six of the eight participants) post- standard reference training sessions. Subsequently, subjects underwent 6-week training protocols, employing standardized high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) regimens. Next, RNA sequencing was conducted to identify differentially expressed piRNAs, and correlation analyses were performed between piRNA expression patterns and training-associated changes in V̇O2max. Finally, to identify piRNAs potentially of interest in the context of exercise, different screening procedures were applied. Results: There were unique and specific changes in individual piRNA expression levels in response to exercise. In addition, we could define correlations of piRNA expression patterns, namely of piR-32886, piR-33151, piR-12547, and piR-33074, with changes in V̇O2max. These correlations did not reach significance in the small sample size of this pilot study, but might be verified in larger, confirming studies. Conclusions: This hypothesis-generating study identifies characteristic piRNA patterns in the context of exercise. Their significance as biomarkers is yet to be determined. Full article

Flight loss has independently evolved across nearly all winged insect orders. Comparing the thoracic structures of flightless insects with those of their flight-capable relatives can reveal key characteristics linked with flight. Although flight loss has been widely studied in beetles, exploration of this phenomenon has been limited to taxonomic and geographic distribution studies in the species-rich family Chrysomelidae, with little analysis of thoracic anatomical structures. This study employs a suite of morphological techniques to examine the thoracic structures of two flightless beetle species Chrysolina: sulcicollis and Chrysolina virgata, originating from desert and temperate regions, respectively. A comparison between the two flightless species reveals that C. sulcicollis has fewer tergo-pleural muscles involved in elytral movement likely to save water, but more muscles that contribute to stabilizing larger body structures. Meanwhile, differences are also observed in the elytral base, the anterior corner of the mesal suture, and the setae on the meso-inner region of the epipleuron. Compared to other flight-capable chrysomelid beetles, apart from the absence of flight-related muscles, the two flightless beetles exhibit similar thoracic skeletal structures. The absence of lateral cervical sclerites, along with the presence of muscles Idvm4, 5 and Itpm5, could enhance head mobility as a compensatory adaptation doe the loss of flight capability. Additionally, the greater number of tergo-pleural muscles in the mesothorax of C. virgata could suggest that its elytra serve a specialized function. Compared to other flightless beetles, aside from the similarly reduced flight muscles, these two species have relatively intact thoracic skeletons. Further data on habitat, functional compensation and other related factors are needed to compare their evolutionary processes with those of other flightless beetles. Full article

Background/Objectives: Sweet taste receptor TAS1R2 is expressed in skeletal muscle, yet its role in muscle metabolism remains poorly understood. Methods: Here, we leverage the BXD recombinant inbred mouse panel and Tas1r2 whole-body knockout (bKO) models to investigate the transcriptional impact of Tas1r2 deficiency on skeletal muscle function. Results: A gene network analysis revealed significant overlap in transcriptomic signatures between BXD strains with low Tas1r2 expression (BXD L_Tas1r2) and bKO muscle, particularly in pathways regulating oxidative phosphorylation, cytoplasmic ribosome function, and proteostasis. Notably, Tas1r2 expression negatively correlated with genes involved in fatty acid metabolism, suggesting its role in lipid utilization. Under high-fat diet (HFD) conditions, BXD_HFD L_Tas1r2 mice exhibited further enrichment in pathways linked to proteasome degradation, oxidative stress, and interleukin signaling, amplifying the transcriptomic convergence with bKO models. Key transcription factors (Mlxipl, Nfic, Rxrb) exhibited altered regulatory patterns under dietary stress, indicating that TAS1R2 influences metabolic adaptability through transcriptional reprogramming. Conclusions: Given that human TAS1R2 variants rarely result in complete loss of function (LOF), the BXD panel provides an effective dose-dependent model to bridge the gap between knockout phenotypes and human SNP carriers. Our findings establish TAS1R2 as a metabolic regulator in skeletal muscle and highlight the utility of genetically diverse mouse populations in dissecting gene-diet interactions relevant to human metabolic diseases. Full article