Integrative biology of exercise

UPLC-MS and multivariate analysis reveal metabolic pathway adaptations to training in professional football players

Metabolomics provides direct insights into biological processes by analyzing metabolites. While univariate and multivariate analyses, alongside pathway and functional analysis tools like mummichog, are commonly employed, integrating these results to interpret biological significance remains a challenge, limiting the potential of metabolomic analyses. This study introduces innovative methods to analyze metabolic adaptations in professional football players using a unique UPLC-TOF-MS dataset comprising 93 urinary samples collected over a 10-month football season. Urinary metabolomic profiles were linked to training load data obtained through an electronic performance tracking system. Three approaches combining multivariate analysis with pathway-level insights were developed. PLS regression p-values integrated with functional metabolic analysis identified training load-associated pathways overlooked by univariate methods. Cluster cross-validation enhanced these insights by assessing the contribution of each pathway to the predictive performance, ranking pathways driving the PLS model. Backward feature elimination refined metabolic features most strongly linked to training load, improving the practicality of findings for targeted biomarker validation. Univariate analyses highlighted alterations in Phenylalanine and Histidine metabolisms related to total external load. Multivariate methods identified additional pathways, including Tryptophan, Purine, and Tyrosine metabolisms, as top contributors to the association between metabolic profiles and training load. Results demonstrate that combining multivariate techniques with functional analysis expands understanding of athletes' metabolic responses, offering more comprehensive biomarker discovery beyond the scope of univariate approaches. These findings underscore the value of integrating multivariate strategies with pathway insights to enhance the biological interpretation of metabolomic data.

Impact of Acute Antioxidant and Tetrahydrobiopterin (BH4) Administration on Locomotor Muscle Microvascular Function in Patients With Heart Failure

BACKGROUND

Peripheral microvascular dysfunction is a hallmark feature of both heart failure with reduced ejection fraction (HFrEF) and preserved ejection fraction (HFpEF) pathophysiology, due partly to impairments in nitric oxide signaling secondary to tetrahydrobiopterin (BH4) deficiency and oxidative stress.

METHODS

Using a randomized, double-blind, placebo-controlled crossover design, this study examined the impact of enteral BH4 (10 mg/kg), an antioxidant cocktail (AOx), and coadministration of these 2 agents (BH4+AOx) on microvascular function in patients with HFrEF (n=14, 64±10 years) and HFpEF (n=19, 74±9 years). Passive limb movement was utilized to assess locomotor muscle microvascular function, and biomarkers of inflammation and oxidative damage were measured.

RESULTS

Compared with placebo, the peak change in leg blood flow was not statistically different after AOx administration (HFrEF, P=0.60; HFpEF, P=0.61), but improved following BH4 (P=0.033) and BH4+AOx (P=0.019) in both HFrEF (placebo: 234±31; BH4: 357±45; BH4+AOx: 355±49 mL/min) and HFpEF (placebo: 269±33; BH4: 367±47; BH4+AOx: 394±65 mL/min). The total hyperemic response to passive limb movement (leg blood flow area under the curve) was not statistically different across treatments in patients with HFrEF (P=0.29), but increased following BH4 (P=0.016) and BH4+AOx (P=0.040) in the HFpEF group. CRP (C-reactive protein) was lower following BH4 (P=0.007) and BH4+AOx (P=0.007) in HFpEF (placebo: 4268±547; BH4: 2721±391; BH4+AOx: 2779±376 ng/mL), but was not statistically different in HFrEF (P=0.39).

CONCLUSIONS

Together, these results provide new evidence for the efficacy of acute BH4 administration to improve some aspects of locomotor muscle microvascular function in patients with HFrEF and HFpEF, with no apparent benefit of AOx administration, alone or in combination with BH4, in either group. These findings lend further conceptual support for the nitric oxide pathway as a modifiable target in the treatment of heart failure.

Muscle-Derived Small Extracellular Vesicles Mediate Exercise-Induced Cognitive Protection in Chronic Cerebral Hypoperfusion

Physical exercise protects against cognitive impairment caused by chronic cerebral hypoperfusion (CCH). However, the mechanisms through which exercise sends signals from the periphery to the central nervous system remain incompletely understood. This study demonstrated that exercise promotes the secretion of muscle-derived small extracellular vesicles (sEVs), which facilitate interorgan communication between the muscle and the brain. Systematic delivery of muscle-derived sEVs enhances synaptic plasticity and alleviated cognitive impairment in CCH. Notably, miRNA sequencing reveal miR-17/20a-5p as key cargos in sEVs involved in the exercise-induced muscle-brain crosstalk. Muscle-derived sEVs are also identified as the primary source of swimming-induced miR-17/20a-5p in circulating sEVs. Mechanistically, miR-17/20a-5p binds to the DEP-domain containing mTOR-interacting protein (DEPTOR) and activates the mammalian target of rapamycin (mTOR) pathway in the hippocampus. Depletion of miR-17/20a-5p from muscle-derived sEVs impairs the exercise-induced enhancement of synaptic plasticity and cognitive function. Moreover, overexpression of DEPTOR in the hippocampus attenuates the cognitive benefits of exercise. Conversely, hippocampus-specific activation of mTOR reverses these effects, highlighting the crucial role of mTOR in mediating the positive effects of exercise. Collectively, these findings identify miR-17/20a-5p in muscle-derived sEVs as the exercise-induced myokine with potent effects on the brain, emphasizing the therapeutic potential of exercise in managing cognitive impairment.

Development and characterization of an Sf-1-Flp mouse model

The use of genetically engineered tools, including combinations of Cre-LoxP and Flp-FRT systems, enables the interrogation of complex biology. Steroidogenic factor-1 (SF-1) is expressed in the ventromedial hypothalamic nucleus (VMH). Development of genetic tools, such as mice expressing Flp recombinase (Flp) in SF-1 neurons (Sf-1-Flp), will be useful for future studies that unravel the complex physiology regulated by the VMH. Here, we developed and characterized Sf-1-Flp mice and demonstrated their utility. The Flp sequence was inserted into the Sf-1 locus with P2A. This insertion did not affect Sf-1 mRNA expression levels and Sf-1-Flp mice do not have any visible phenotypes. They are fertile and metabolically comparable to wild-type littermate mice. Optogenetic stimulation using adeno-associated virus (AAV) carrying Flp-dependent channelrhodopsin-2 (ChR2) increased blood glucose and skeletal muscle PGC-1α in Sf-1-Flp mice. This was similar to SF-1 neuronal activation using Sf-1-BAC-Cre and AAV carrying Cre-dependent ChR2. Finally, we generated Sf-1-Flp mice that lack β2-adrenergic receptors (Adrb2) only in skeletal muscle with a combination of Cre/LoxP technology (Sf-1-Flp:SKMΔAdrb2). Optogenetic stimulation of SF-1 neurons failed to increase skeletal muscle PGC-1α in Sf-1-Flp:SKMΔAdrb2 mice, suggesting that Adrb2 in skeletal muscle is required for augmented skeletal muscle PGC-1α by SF-1 neuronal activation. Our data demonstrate that Sf-1-Flp mice are useful for interrogating complex physiology.

The effects and post-exercise energy metabolism characteristics of different high-intensity interval training in obese adults

This study aimed to compare the effects of two high-intensity interval training modalities on body composition and muscular fitness in obese young adults and examined the characteristics of energy expenditure (EE) after training. Thirty-six obese young adults (eleven female, age: 22.1 ± 2.3 years, BMI: 25.1 ± 1.2 kg/m2) were to Whole-body high-intensity interval training group (WB-HIIT) (n = 12), jump rope high-intensity interval training group (JR-HIIT) (n = 12), or non-training control group (CG) (n = 12). WB-HIIT and JR-HIIT groups performed an 8-week HIIT protocol. WB-HIIT, according to the program of unarmed resistance training, JR-HIIT use rope-holding continuous jump training, each execution of 4 sets of 4 × 30 s training, interval 30 s, inter-set interval 1min, and the control group maintained their regular habits without additional exercise training. Body composition and muscular strength were assessed before and after 8 weeks. Repeated measures analysis of variance and clinical effect analysis using Cohen's effect size were used, with a significance level of p < 0.05. In comparison with the CG group in both experimental groups, Body Mass and BMI significantly reduced (p < 0.05), and Muscular strength significantly improved (p < 0.05).WB-HIIT versus JR-HIIT: Fat Mass (- 1.5 ± 1.6; p = 0.02 vs - 2.3 ± 1.2; p < 0.01) and % Body Fat (- 1.3 ± 1.7; p = 0.05 vs - 1.9 ± 1.9; p < 0.01) the effect is more pronounced in the JR-HIIT group; Muscle Mass (1.5 ± 0.7; p < 0.01 vs - 0.8 ± 1.1; p = 0.07) the effect is more pronounced in the WB-HIIT group. Estimated daily energy intake (122 ± 459 vs 157 ± 313; p > 0.05). Compared to the CG, body composition was significantly improved in both intervention groups. All three groups had no significant changes in visceral adipose tissue (p > 0.05). Significant differences in Lipid and Carbohydrate oxidation and energy output were observed between the two groups, as well as substantial differences in WB-HIIT and JR-HIIT VO2, ventilation, and energy consumption minute during the 0-5 min post-exercise period (p > 0.05). WB-HIIT and JR-HIIT interventions effectively improve the body composition of young adults with obesity, while WB-HIIT additionally improves muscular fitness. After exercise, WB-HIIT produces higher excess post-exercise oxygen consumption and associated lipid and carbohydrate metabolism than JR-HIIT.

Phosphoproteomics Uncovers Exercise Intensity-Specific Skeletal Muscle Signaling Networks Underlying High-Intensity Interval Training in Healthy Male Participants

BACKGROUND

In response to exercise, protein kinases and signaling networks are engaged to blunt homeostatic threats generated by acute contraction-induced increases in skeletal muscle energy and oxygen demand, as well as serving roles in the adaptive response to chronic exercise training to blunt future disruptions to homeostasis. High-intensity interval training (HIIT) is a time-efficient exercise modality that induces superior or similar health-promoting skeletal muscle and whole-body adaptations compared with prolonged, moderate-intensity continuous training (MICT). However, the skeletal muscle signaling pathways underlying HIIT's exercise intensity-specific adaptive responses are unknown.

OBJECTIVE

We mapped human muscle kinases, substrates, and signaling pathways activated/deactivated by an acute bout of HIIT versus work-matched MICT.

METHODS

In a randomized crossover trial design (Australian New Zealand Clinical Trials Registry number ACTRN12619000819123; prospectively registered 6 June 2019), ten healthy male participants (age 25.4 ± 3.2 years; BMI 23.5 ± 1.6 kg/m2;V ˙ O 2 max 37.9 ± 5.2 ml/kg/min, mean values ± SD) completed a single bout of HIIT and MICT cycling separated by ≥ 10 days and matched for total work (67.9 ± 10.2 kJ) and duration (10 min). Mass spectrometry-based phosphoproteomic analysis of muscle biopsy samples collected before, during (5 min), and immediately following (10 min) each exercise bout, to map acute temporal signaling responses to HIIT and MICT, identified and quantified 14,931 total phosphopeptides, corresponding to 8509 phosphorylation sites.

RESULTS

Bioinformatic analyses uncovered exercise intensity-specific signaling networks, including > 1000 differentially phosphorylated sites (± 1.5-fold change; adjusted P < 0.05; ≥ 3 participants) after 5 min and 10 min HIIT and/or MICT relative to rest. After 5 and 10 min, 92 and 348 sites were differentially phosphorylated by HIIT, respectively, versus MICT. Plasma lactate concentrations throughout HIIT were higher than MICT (P < 0.05), and correlation analyses identified > 3000 phosphosites significantly correlated with lactate (q < 0.05) including top functional phosphosites underlying metabolic regulation.

CONCLUSIONS

Collectively, this first global map of the work-matched HIIT versus MICT signaling networks has revealed rapid exercise intensity-specific regulation of kinases, substrates, and pathways in human skeletal muscle that may contribute to HIIT's skeletal muscle adaptations and health-promoting effects.  Preprint: The preprint version of this work is available on medRxiv, https://doi.org/10:1101/2024.07.11.24310302 .

Synergistic strength: unleashing exercise and polyphenols against breast cancer

Breast cancer remains a major global health challenge, necessitating innovative preventive and therapeutic strategies. Emerging evidence such as clinical trials suggests that the combination of exercise and polyphenol intake exerts synergistic effects in mitigating breast cancer progression by modulating key molecular pathways. Exercise enhances immune function, reduces inflammation, and regulates cellular metabolism, while polyphenols, natural compounds found in various plant-based foods, exhibit antioxidant, anti-inflammatory, and anti-carcinogenic properties. Together, these interventions influence apoptosis, oxidative stress, and ferroptosis which play crucial roles in breast cancer pathophysiology. This review explores the molecular mechanisms underlying the combined impact of exercise and polyphenols on breast cancer prevention and treatment. Understanding the interplay between exercise and polyphenols at the molecular level could pave the way for novel, non-invasive therapeutic strategies. Future research should focus on optimizing exercise regimens and dietary interventions to maximize their anti-cancer benefits. By bridging molecular insights with clinical applications, this review aims to provide a foundation for incorporating lifestyle-based interventions into breast cancer management. Our findings collectively highlight the promising potential of combining curcumin supplementation with exercise as a multifaceted approach to breast cancer treatment. The synergistic effects observed in various studies suggest that integrating lifestyle modifications with dietary interventions may enhance therapeutic efficacy and mitigate cancer progression. Further clinical investigations are warranted to validate these results and explore their applicability in human subjects. The evidence supports a holistic strategy for breast cancer management that could improve patient outcomes and quality of life during treatment.

miR-126: a bridge between cancer and exercise

The microRNA miR-126 supports endothelial cells and blood vessel integrity. Recent research has shown that it also serves as a key link between exercise and cancer. This article delves into how exercise affects the expression of miR-126, impacting cardiovascular well-being and metabolic control. The article also examines the various contributions of miR-126 in cancer, acting as both a suppressor and an enhancer depending on the particular context. Regular aerobic exercises, including HIIT, consistently increase levels of miR-126, leading to enhanced angiogenesis, endothelial repair, and improved vascular function through mechanisms involving VEGF, HIF-1α, and EPC mobilization. Resistance training affects similar pathways, but does not cause a significant change in miR-126 levels.MiR-126 involves in cancer by suppressing tumor growth and controlling key pathways such as PI3K/Akt, ERK/MAPK, and EMT. Lower levels are associated with negative outcomes, later stages of the disease, and increased spread of different types of cancer like glioblastoma, CRC, ovarian, esophageal, gastric, and prostate cancer.The relationship between exercise and cancer suggests a possible therapeutic approach, where the regulation of miR-126 through exercise could help improve vascular function and slow tumor growth. Further studies should focus on understanding the specific molecular pathways through which miR-126 connects these areas, leading to potential interventions that utilize its regulatory network to promote cardiovascular well-being and enhance cancer treatment.

Training Status Influences Regulation of Muscle and PBMC TLR4 Expression and Systemic Cytokine Responses to Vigorous Endurance Exercise

INTRODUCTION

A bout of vigorous endurance exercise transiently activates Toll-like receptor 4 (TLR4) and reduces TLR4 protein expressed on peripheral blood mononuclear cells (PBMCs). Endurance training, on the other hand, reduces TLR4-mediated signaling and minimizes the physiological stress imposed by exercise. Less is known about what occurs in skeletal muscle regarding TLR4 regulation and signaling. Therefore, this study aimed to investigate the regulation of TLR4 expressed in different tissue types (PBMCs and skeletal muscle samples) between endurance-trained and untrained men following vigorous endurance exercise and determine the effect of training status on cytokine responses associated with TLR4 activation.

METHODS

Endurance-trained ( n = 7) and untrained ( n = 5) men cycled for 1 h at their respiratory compensation point, with blood and skeletal muscle samples collected pre- and 3 h post-exercise.

RESULTS

In response to vigorous exercise, untrained men experienced a decrease in inhibitor of κBα (IκBα) protein (suggesting IκB degradation and the activation of TLR4-associated transcription factor NF-κB) and TLR4 protein levels, along with a simultaneous increase in TLR4 mRNA expression in both skeletal muscle and PBMCs. Moreover, this exercise session led to elevated levels of circulating interleukin-6, tumor necrosis factor-α, and interleukin-1β. Collectively, these results suggest a heightened TLR4-mediated signaling pathway in untrained men. However, no changes in these targets were observed in endurance-trained men, possibly indicating a potential mechanism by which regular endurance training blunts systemic inflammation.

CONCLUSIONS

These findings highlight the potential of endurance training to mitigate TLR4-mediated signaling, such as systemic inflammation, and shed light on the effects of exercise on TLR4 expression in PBMCs and skeletal muscle.

Glucose metabolism in the perfused liver did not improve with resistance training in male Swiss mice under caloric restriction

CONTEXT

Energy homeostasis is a primary factor for the survival of mammals. Many tissues and organs, among which is the liver, keep this homeostasis in varied circumstances, including caloric restriction (CR) and physical activity.

OBJECTIVE

This study investigated glucose metabolism using the following groups of eight-week-old male Swiss mice: CS, sedentary and fed freely; RS, sedentary and RT, trained, both under 30% CR (n = 20-23 per group).

RESULTS

Organs and fat depots of groups RS and RT were similar to CS, although body weight was lower. CR did not impair training performance nor affected systemic or hepatic glucose metabolism. Training combined with CR (group RT) improved in vivo glucose tolerance and did not affect liver gluconeogenesis.

CONCLUSIONS

The mice tolerated the prolonged moderate CR without impairment of their well-being, glucose homeostasis, and resistance training performance. But the higher liver gluconeogenic efficiency previously demonstrated using this training protocol in mice was not evidenced under CR.

Ergothioneine controls mitochondrial function and exercise performance via direct activation of MPST

Ergothioneine (EGT) is a diet-derived, atypical amino acid that accumulates to high levels in human tissues. Reduced EGT levels have been linked to age-related disorders, including neurodegenerative and cardiovascular diseases, while EGT supplementation is protective in a broad range of disease and aging models. Despite these promising data, the direct and physiologically relevant molecular target of EGT has remained elusive. Here, we use a systematic approach to identify how mitochondria remodel their metabolome in response to exercise training. From these data, we find that EGT accumulates in muscle mitochondria upon exercise training. Proteome-wide thermal stability studies identify 3-mercaptopyruvate sulfurtransferase (MPST) as a direct molecular target of EGT; EGT binds to and activates MPST, thereby boosting mitochondrial respiration and exercise training performance in mice. Together, these data identify the first physiologically relevant EGT target and establish the EGT-MPST axis as a molecular mechanism for regulating mitochondrial function and exercise performance.

Cellular deconstruction of the human skeletal muscle microenvironment identifies an exercise-induced histaminergic crosstalk

Plasticity of skeletal muscle is induced by transcriptional and translational events in response to exercise, leading to multiple health and performance benefits. The skeletal muscle microenvironment harbors myofibers and mononuclear cells, but the rich cell diversity has been largely ignored in relation to exercise adaptations. Using our workflow of transcriptome profiling of individual myofibers, we observed that their exercise-induced transcriptional response was surprisingly modest compared with the bulk muscle tissue response. Through the integration of single-cell data, we identified a small mast cell population likely responsible for histamine secretion during exercise and for targeting myeloid and vascular cells rather than myofibers. We demonstrated through histamine H1 or H2 receptor blockade in humans that this paracrine histamine signaling cascade drives muscle glycogen resynthesis and coordinates the transcriptional exercise response. Altogether, our cellular deconstruction of the human skeletal muscle microenvironment uncovers a histamine-driven intercellular communication network steering muscle recovery and adaptation to exercise.

Acute treadmill exercise induces mitochondrial unfolded protein response in skeletal muscle of male rats

Mitochondria are often referred to as the energy centers of the cell and are recognized as key players in signal transduction, sensing, and responding to internal and external stimuli. Under stress conditions, the mitochondrial unfolded protein response (UPRmt), a conserved mitochondrial quality control mechanism, is activated to maintain mitochondrial and cellular homeostasis. As a physiological stimulus, exercise-induced mitochondrial perturbations trigger UPRmt, coordinating mitochondria-to-nucleus communication and initiating a transcriptional program to restore mitochondrial function. The aim of this study was to evaluate the UPRmt signaling response to acute exercise in skeletal muscle. Male rats were subjected to acute treadmill exercise at 25 m/min for 60 min on a 0 % grade. Plantaris muscles were collected from both sedentary and exercise groups at various times: immediately (0), and at 1, 3, 6, 12, and 24 h post-exercise. Reactive oxygen species (ROS) production was assessed using hydrogen peroxide assay and dihydroethidium staining. Additionally, the mRNA and protein expression of UPRmt markers were measured using ELISA and real-time PCR. Mitochondrial activity was assessed using succinate dehydrogenase (SDH) and cytochrome c oxidase (COX) staining. Our results demonstrated that acute exercise increased ROS production and upregulated UPRmt markers at both gene and protein levels. Moreover, skeletal muscle exhibited an increase in mitochondrial activity in response to exercise, as indicated by SDH and COX staining. These findings suggest that acute treadmill exercise is sufficient to induce ROS production, activate UPRmt signaling, and enhance mitochondrial activity in skeletal muscle, expanding our understanding of mitochondrial adaptations to exercise.

Association between objectively assessed physical activity and kidney function among female agricultural workers in hot environments in Spain

BACKGROUND

Physical activity in hot environments has been associated with impaired kidney function. We aimed to quantify the association between occupational physical activity and kidney function over one work shift in female agricultural workers exposed to environmental heat.

METHODS

We measured occupational physical activity in female berry pickers in Huelva, Spain, using movement intensity, based on vector magnitude units (VMU), and heart rate (HR). For both, we calculated the mean (VMU_mean; HR_mean), standard deviation (VMU_sd; HR_sd), and 3-min 95th percentile (VMU_p95; HR_p95). Environmental heat in greenhouses was estimated using wet bulb globe temperature (WBGT). Kidney function and injury were quantified using pre- and post-shift differences in serum creatinine (SCr_dif), Cystatin C (Cystatin C_dif) and neutrophil gelatinase associated lipocalin (NGAL_dif), respectively. Acute Kidney Injury (AKI) was defined as an increase in post-shift serum creatinine of ≥0.3 mg/dl, or ≥1.5 times pre-shift levels. Heat strain was estimated using the ISO 7933:2004 index. We used linear and logistic regressions.

RESULTS

Ninety women aged 37.4 ± 5.7 years were exposed to a mean WBGT of 25.2 (±3.6)°C and light intensity physical activity (HR_mean of 94 (±9)bpm). Of those, 26 % experienced heat strain, 68 % were dehydrated, and 7 % presented with AKI at the end of the shift. Higher VMU_sd was associated with higher Scr_dif (β: 0.029 (95 % CI: 0.00; 0.058) and meeting the threshold for AKI (OR: 1.6 (95 % CI: 0.8; 3.2)). We observed higher NGAL_dif with higher VMU_mean (β: 1.944 (95 % CI: 0.139; 3.748)) per 100 VMU_mean increase. The positive association between HR_mean and SCr_dif was stronger among women with heat strain (interaction p = 0.033).

CONCLUSIONS AND RELEVANCE

In female harvest workers, high means and variations in VMU over a single one shift worked under hot conditions were associated with kidney injury, as assessed by urinary biomarkers, though there is limited evidence for any change in kidney function. Precautiously, large changes in physical activity intensity over one work shift should be avoided to protect from renal injury.

Role of exercise on the reduction of cancer development: a mechanistic review from the lncRNA point of view

More research has been done on the correlation between exercise and cancer, which has revealed several ways that physical activity decreases the risk of developing the disease. The developing function of lncRNAs as an important molecular link between exercise and cancer suppression is the main topic of this review. According to recent research, regular physical exercise also alters the expression levels of several lncRNAs, which are generally elevated in cancer. A complex network of interactions that may provide protective effects against carcinogenesis is suggested by the contribution of these lncRNAs in various cellular processes, such as epigenetic alterations, proliferation, and apoptosis regulation. We offer a comprehensive summary of the existing information regarding specific lncRNAs that are influenced by physical activity and could potentially impact cancer-related processes. We also go over the difficulties in interpreting these alterations, taking into account the fact that several lncRNAs have a dual function in promoting and preventing cancer in various physiological settings. To understand the complex impacts of exercise-induced lncRNA regulation in cancer biology, more study is required. The critique strongly highlights the possibility of lncRNAs serving as both indicators and treatment prospects for cancer-preventive strategies.

Flexible Fiber Sensors for Real-Time Monitoring of Redox Signaling Molecules in Exercise-Mimicking Engineered Skeletal Muscle

Real-time monitoring of reactive oxygen and nitrogen species (RONS) in skeletal muscle provides crucial insights into the cause-and-effect relationships between physical activity and health benefits. However, the dynamic production of exercise-induced RONS remains poorly explored, due to the lack of sensing tools that can conform to soft skeletal muscle while monitor RONS release during exercise. Here we introduce dual flexible sensors via twisting carbon nanotubes into helical bundles of fibers and subsequent assembling electrochemical sensing components. These flexible sensors exhibit low bending stiffness, excellent H2O2 and NO sensing abilities, outstanding biocompatibility and compliance with engineered skeletal muscle tissue. This allows real-time and simultaneous monitoring of H2O2 and NO release from engineered skeletal muscle in response to different exercise-mimicking stretches, which reveals that warm-up activities before high-intensity exercise may enhance adaptive responses by down-regulating H2O2 and up-regulating NO production. The proposed sensing strategy demonstrates great versatility in monitoring multiple biomarkers of soft tissue and organs.

The effect of exercise and physical activity on skeletal muscle epigenetics and metabolic adaptations

Physical activity (PA) and exercise elicit adaptations and physiological responses in skeletal muscle, which are advantageous for preserving health and minimizing chronic illnesses. The complicated atmosphere of the exercise response can be attributed to hereditary and environmental variables. The primary cause of these adaptations and physiological responses is the transcriptional reactions that follow exercise, whether endurance- (ET) or resistance- training (RT). As a result, the essential metabolic and regulatory pathways and myogenic genes associated with skeletal muscle alter in response to acute and chronic exercise. Epigenetics is the study of the relationship between genetics and the environment. Exercise evokes signaling pathways that strongly alter myofiber metabolism and skeletal muscle physiological and contractile properties. Epigenetic modifications have recently come to light as essential regulators of exercise adaptations. Research has shown various epigenetic markers linked to PA and exercise. The most critical epigenetic alterations in gene transcription identified are DNA methylation and histone modifications, which are associated with the transcriptional response of skeletal muscle to exercise and facilitate the modification to exercise. Other changes in the epigenetic markers are starting to emerge as essential processes for gene transcription, including acetylation as a new epigenetic modification, mediated changes by methylation, phosphorylation, and micro-RNA (miRNA). This review briefly introduces PA and exercise and associated benefits, provides a summary of epigenetic modifications, and a fundamental review of skeletal muscle physiology. The objectives of this review are 1) to discuss exercise-induced adaptations related to epigenetics and 2) to examine the interaction between exercise metabolism and epigenetics.

High-Modulus Homochiral Torsional Oxide Ceramic Artificial Muscles

Fiber-based artificial muscles are soft actuators used to mimic the movement of human muscles. However, using high modulus oxide ceramics to fabricate artificial muscles with high energy and power is a challenge as they are prone to brittle fracture during torsion. Here, a ceramic metallization strategy is reported that solves the problem of low torsion and low ductility of alumina (Al2O3) ceramics by chemical plating a thin copper layer on alumina filaments. These filaments with a high modulus of ≈180 GPa can be twisted into chiral coiled artificial muscles, exhibiting a unique electric thermal actuation mechanism. This tough and robust alumina artificial muscle can carry objects equivalent to 0.28 million times its weight and provide high actuation stress of up to 483.5 MPa. In addition, it exhibits 18 times higher contraction power and 240 times higher energy density than human muscles, as well as a high energy conversion efficiency of up to 7.59%, which far exceeds most reported actuated carbon and polymer artificial muscles. This work has achieved large-scale manufacturing of high-modulus oxide ceramic muscles for the first time.

The role of skeletal muscle respiratory capacity in exercise performance

The connection between the respiratory capacity of skeletal muscle mitochondria and athletic performance is widely acknowledged in contemporary research. Building on a solid foundation of prior studies, current research has fostered an environment where scientists can effectively demonstrate how a tailored regimen of exercise intensity, duration, and frequency significantly boosts mitochondrial function within skeletal muscles. The range of exercise modalities is broad, spanning from endurance and high-intensity interval training to resistance-based exercises, allowing for an in-depth exploration of effective strategies to enhance mitochondrial respiratory capacity-a key factor in improving exercise performance, in other words offering a better skeletal muscle capacity to cope with exercise demands. By identifying optimal training strategies, individuals can significantly improve their performance, leading to better outcomes in their fitness and athletic endeavours. This review provides the prevailing insights on skeletal muscle mitochondrial respiratory capacity and its role in exercise performance, covering essential instrumental and methodological aspects, findings from animal studies, potential sex differences, a review of existing human studies, and considerations for future research directions.

Oxidative Stress in Brain Function

Oxidative stress (OS) is an important factor in the pathophysiology of numerous neurodegenerative disorders, such as Parkinson's disease, multiple sclerosis, cerebrovascular pathology or Alzheimer's disease. OS also significantly influences progression among the various neurodegenerative disorders. The imbalance between the formation of reactive oxygen species (ROS) and the body's capacity to neutralize these toxic byproducts renders the brain susceptible to oxidative injury. Increased amounts of ROS can result in cellular malfunction, apoptosis and neurodegeneration. They also represent a substantial factor in mitochondrial dysfunction, a defining characteristic of neurodegenerative disorders. Comprehending the fundamental mechanisms of OS and its interactions with mitochondrial function, neuroinflammation and cellular protective pathways becomes essential for formulating targeted therapeutics to maintain brain health and reduce the impacts of neurodegeneration. We address recent highlights on the role of OS in brain function in terms of significance for neuronal health and the progression of neurodegenerative disorders.

Development and Characterization of a Sf-1-Flp Mouse Model

The use of genetically engineered tools, including combinations of Cre-LoxP and Flp-FRT systems, enable the interrogation of complex biology. Steroidogenic factor-1 (SF-1) is expressed in the ventromedial hypothalamic nucleus (VMH). Development of genetic tools, such as mice expressing Flp recombinase (Flp) in SF-1 neurons (Sf-1-Flp), will be useful for future studies that unravel the complex physiology regulated by the VMH. Here, we developed and characterized Sf-1-Flp mice and demonstrated its utility. Flp sequence was inserted into Sf-1 locus with P2A. This insertion did not affect Sf-1 mRNA expression levels and Sf-1-Flp mice do not have any visible phenotypes. They are fertile and metabolically comparable to wild-type littermate mice. Optogenetic stimulation using adeno-associated virus (AAV)-bearing Flp-dependent channelrhodopsin-2 (ChR2) increased blood glucose and skeletal muscle PGC-1α in Sf-1-Flp mice. This was similar to SF-1 neuronal activation using Sf-1-BAC-Cre and AAV-bearing Cre-dependent ChR2. Finally, we generated Sf-1-Flp mice that lack β2-adrenergic receptors (Adrβ2) only in skeletal muscle with a combination of Cre/LoxP technology (Sf-1-Flp::SKMΔAdrβ2). Optogenetic stimulation of SF-1 neurons failed to increase skeletal muscle PGC-1α in Sf-1-Flp::SKMΔAdrβ2 mice, suggesting that Adrβ2 in skeletal muscle is required for augmented skeletal muscle PGC-1α by SF-1 neuronal activation. Our data demonstrate that Sf-1-Flp mice are useful for interrogating complex physiology.

Individual bioenergetic capacity as a potential source of resilience to Alzheimer's disease

Impaired glucose uptake in the brain is an early presymptomatic manifestation of Alzheimer's disease (AD), with symptom-free periods of varying duration that likely reflect individual differences in metabolic resilience. We propose a systemic "bioenergetic capacity", the individual ability to maintain energy homeostasis under pathological conditions. Using fasting serum acylcarnitine profiles from the AD Neuroimaging Initiative as a blood-based readout for this capacity, we identified subgroups with distinct clinical and biomarker presentations of AD. Our data suggests that improving beta-oxidation efficiency can decelerate bioenergetic aging and disease progression. The estimated treatment effects of targeting the bioenergetic capacity were comparable to those of recently approved anti-amyloid therapies, particularly in individuals with specific mitochondrial genotypes linked to succinylcarnitine metabolism. Taken together, our findings provide evidence that therapeutically enhancing bioenergetic health may reduce the risk of symptomatic AD. Furthermore, monitoring the bioenergetic capacity via blood acylcarnitine measurements can be achieved using existing clinical assays.

Update on Exercise in Persons With Muscle Disease

Myopathies are heterogeneous in their etiology, muscle group involvement, clinical manifestation, and progression. Deficits in myopathy may include muscle weakness, atrophy, stiffness, myalgia, and extra-muscular manifestations. Consequently, these deficits could lead to impaired musculoskeletal function, inadequate engagement in daily activities and reduced participation in social activities. Exercise has been viewed as a potentially efficacious intervention to halt the loss of muscle function and to improve secondary symptoms that result from muscle loss, such as pain and fatigue. The purpose of this review is to discuss research findings within the last 10 years that examine effects of exercise interventions in many types of myopathies in humans. In general, most studies were small scale, and they varied with respect to exercise type, intensity, and outcome measures. Despite the different pathologies, various exercise subtypes of aerobic/endurance or strength/resistance training are generally beneficial and may improve muscle strength and functional outcomes. Exercise therapies are generally safe and well tolerated. Exercise prescription should be part of routine neuromuscular care for patients with myopathy, and ideally with input from a multidisciplinary team, with a focus on providing individualized exercise regimens. Further work is needed to define the optimal intensity and type of exercise to result in the best functional outcomes for persons with myopathy, as well as the effects of combining exercise and novel disease modifying therapies.

Exercise, Gut Microbiome, and Gastrointestinal Diseases: Therapeutic Impact and Molecular Mechanisms

The benefits of regular physical activity (PA) on disease prevention and treatment outcomes have been recognized for centuries. However, only recently has interorgan communication triggered by the release of "myokines" from contracting skeletal muscles emerged as a putative mechanism by which exercise confers protection against numerous disease states. Cross-talk between active skeletal muscles and the gut microbiota reveal how regular PA boosts host immunity, facilitates a more diverse gut microbiome and functional metabolome, and plays a positive role in energy homeostasis and metabolic regulation. In contrast, and despite the large interindividual variation in the human gut microbiome, reduced microbial diversity has been implicated in several diseases of the gastrointestinal (GI) tract, systemic immune diseases, and cancers. Although prolonged, intense, weight-bearing exercise conducted in extreme conditions can increase intestinal permeability, compromising gut-barrier function and resulting in both upper and lower GI symptoms, these are transient and benign. Accordingly, the gut microbiome has become an attractive target for modulating many of the positive effects of regular PA on GI health and disease, although the precise dose of exercise required to induce favourable changes in the microbiome and enhance host immunity is currently unknown. Future efforts should concentrate on gaining a deeper understanding of the factors involved in exercise-gut interactions through the generation of functional 'omics readouts (ie, metatranscriptomics, metaproteomics, and metabolomics) that have the potential to identify functional traits of the microbiome that are linked to host health and disease states, and validating these interactions in experimental and preclinical systems. A greater understanding of how PA interacts with the GI tract and the microbiome may enable targeted therapeutic strategies to be developed for individuals and populations at risk for a variety of GI diseases.

Endurance exercise remodels skeletal muscle by suppressing Ythdf1-mediated myostatin expression

Exercise can improve health via skeletal muscle remodeling. Elucidating the underlying mechanism may lead to new therapeutics for aging-related loss of skeletal muscle mass. Here, we show that endurance exercise suppresses expression of YT521-B homology domain family (Ythdf1) in skeletal muscle, which recognizes the N6-methyladenosine (m6A). Ythdf1 deletion phenocopies endurance exercise-induced muscle hypertrophy in mice increases muscle mitochondria content and type I fiber specification. At the molecular level, Ythdf1 recognizes and promotes the translation of m6A-modified Mstn mRNA, which encodes a muscle growth inhibitor, Myostatin. Loss of Ythdf1 leads to hyperactivation of skeletal muscle stem cells (MuSCs), also called satellite cells (SCs), enhancing muscle growth and injury-induced regeneration. Our data reveal Ythdf1 as a key regulator of skeletal muscle homeostasis, provide insights into the mechanism by which endurance exercise promotes skeletal muscle remodeling and highlight potential strategies to prevent aging-related muscle degeneration.

Untargeted Metabolomics and Proteomics-Based Research of the Long-Term Exercise on Human Body

Regular long-term exercise can benefit the body and reduce the risk of several diseases, such as cardiovascular disease, diabetes, and obesity. However, the proteomic and metabolomic changes, as well as the physiological responses associated with long-term exercise, remain incompletely understood. To investigate the effects of long-term exercise on the human body, 14 subjects with long-term exercise habits and 10 subjects without exercise habits were selected for this study. Morning urine samples were collected and analyzed for untargeted metabolomics and proteomics using liquid chromatography-mass spectrometry. A total of 404 differential metabolites and 394 differential proteins were screened in this research, and the analysis results indicated that long-term exercise may affect energy metabolism, amino acid synthesis and metabolism, nucleotide metabolism, steroid hormone biosynthesis, and the inflammatory response. These findings offer a more comprehensive understanding of the molecular effects of long-term exercise on the human body and provide a basis for future research exploring the underlying mechanisms.

Differential Regulation of miRNA and Protein Profiles in Human Plasma-Derived Extracellular Vesicles via Continuous Aerobic and High-Intensity Interval Training

Both continuous aerobic training (CAT) and high-intensity interval training (HIIT) are recommended to promote health and prevent diseases. Exercise-induced circulating extracellular vesicles (EX-EVs) have been suggested to play essential roles in mediating organ crosstalk, but corresponding molecular mechanisms remain unclear. To assess and compare the systemic effects of CAT and HIIT, five healthy male volunteers were assigned to HIIT and CAT, with a 7-day interval between sessions. Plasma EVs were collected at rest or immediately after each training section, prior to proteomics and miRNA profile analysis. We found that the differentially expressed (DE) miRNAs in EX-EVs were largely involved in the regulation of transcriptional factors, while most of the DE proteins in EX-EVs were identified as non-secreted proteins. Both CAT and HIIT play common roles in neuronal signal transduction, autophagy, and cell fate regulation. Specifically, CAT showed distinct roles in cognitive function and substrate metabolism, while HIIT was more associated with organ growth, cardiac muscle function, and insulin signaling pathways. Interestingly, the miR-379 cluster within EX-EVs was specifically regulated by HIIT, involving several biological functions, including neuroactive ligand-receptor interaction. Furthermore, EX-EVs likely originate from various tissues, including metabolic tissues, the immune system, and the nervous system. Our study provides molecular insights into the effects of CAT and HIIT, shedding light on the roles of EX-EVs in mediating organ crosstalk and health promotion.

Causal association of physical activity with lymphoma risk: a Mendelian randomization analysis

Controversial relationship of physical activity with lower lymphoma risk has been reported in observational studies. The purpose of this study was to explore the causal correlation of physical activity with lymphoma risk using two-sample Mendelian randomization (MR). Genetic variants associated with physical activity (moderate-to-vigorous physical activity (MVPA), average acceleration physical activity, number of days/week of moderate physical activity 10+ min, and number of days/week of vigorous physical activity 10+ min) and lymphoma [overall lymphoma, Hodgkin lymphoma, mature T/NK-cell lymphomas, diffuse large B-cell lymphoma (DLBCL), and follicular lymphoma] were obtained from published genome-wide association studies (GWAS) and the FinnGen database and used as instrumental variables. Primary results were based on inverse variance-weighted (IVW) analysis and were described as odds ratio (OR) and 95% confidence interval (CI). Higher levels of genetically predicted MVPA (OR = 0.079, 95% CI: 0.021-0.300, P = 0.0002) and number of days/week of vigorous physical activity 10+ min (OR = 0.237, 95% CI: 0.098-0.573, P = 0.0014) were negatively associated with Hodgkin lymphoma risk. There was a weak negative association between high levels of genetically predicted MVPA (OR = 0.114, 95% CI: 0.015-0.856, P = 0.0348) and average acceleration physical activity (OR = 0.830, 95% CI: 0.705-0.976, P = 0.0243) and risk of DLBCL. No causal relationship was observed between physical activity and the risk of overall lymphoma, mature T/NK-cell lymphomas, and follicular lymphoma (P > 0.05). This study supported the causal relationship between higher physical activity levels and lower risks of Hodgkin lymphoma and DLBCL.

Cannabidiol reshapes the gut microbiome to promote endurance exercise in mice

Cannabidiol (CBD), a nonpsychoactive compound from Cannabis, has various bioactive functions in humans and animals. Evidence suggests that CBD promotes muscle injury recovery in athletes, but whether and how CBD improves endurance performance remains unclear. Here we investigated the effects of CBD treatment on exercise performance in mice and assessed whether this effect involves the gut microbiome. CBD administration significantly increased treadmill running performance in mice, accompanied by an increase in oxidative myofiber composition. CBD also increased mitochondrial biogenesis and the expression of associated genes such as PGC-1α, phosphorylated CREB and AMPK in muscle tissue. Interestingly, CBD altered the composition of the gut microbiome, and antibiotic treatment reduced the muscle endurance-enhancing effects of CBD and mitochondrial biogenesis. We isolated Bifidobacterium animalis, a microbe increased by CBD administration, and named it KBP-1. Treatment with B. animalis KBP-1 in mice resulted in improved running performance. Whole-genome analysis revealed that B. animalis KBP-1 presented high expression of genes involved in branched-chain amino acid biosynthesis, expression of branched-chain amino acid release pumps and metabolism of lactic acid. In summary, our study identified CBD and B. animalis KBP-1 as potential endurance exercise-promoting agents.

Atherosclerosis and the Bidirectional Relationship Between Cancer and Cardiovascular Disease: From Bench to Bedside, Part 2 Management

The first part of this review highlighted the evolving landscape of atherosclerosis, noting emerging cardiometabolic risk factors, the growing impact of exposomes, and social determinants of health. The prominent role of atherosclerosis in the bidirectional relationship between cardiovascular disease and cancer was also discussed. In this second part, we examine the complex interplay between multimorbid cardio-oncologic patients, cardiometabolic risk factors, and the harmful environments that lend a "syndemic" nature to these chronic diseases. We summarize management strategies targeting disordered cardiometabolic factors to mitigate cardiovascular disease and explore molecular mechanisms enabling more tailored therapies. Importantly, we emphasize the early interception of atherosclerosis through multifactorial interventions that detect subclinical signs (via biomarkers and imaging) to treat modifiable risk factors and prevent clinical events. A concerted preventive effort-referred to by some as a "preventome"-is essential to reduce the burden of atherosclerosis-driven chronic diseases, shifting from mere chronic disease management to the proactive promotion of "chronic health".

Cellular Feimin enhances exercise performance by suppressing muscle thermogenesis

Exercise can rapidly increase core body temperature, and research has indicated that elevated internal body temperature can independently contribute to fatigue during physical activity. However, the precise mechanisms responsible for regulating thermogenesis in muscles during exercise have remained unclear. Here, we demonstrate that cellular Feimin (cFeimin) enhances exercise performance by inhibiting muscle thermogenesis during physical activity. Mechanistically, we found that AMP-activated protein kinase (AMPK) phosphorylates cFeimin and facilitates its translocation into the cell nucleus during exercise. Within the nucleus, cFeimin binds to the forkhead transcription factor FOXC2, leading to the suppressed expression of sarcolipin (Sln), which is a key regulator of muscle thermogenesis. In addition, our results further reveal that short-term AMPK agonist treatments can enhance exercise performance through the activation of the AMPK-cFeimin signalling pathway. In summary, these results underscore the crucial role of cFeimin in enhancing exercise performance by modulating SLN-mediated thermogenesis.

History and perspectives on interval training in sport, health, and disease

Exercise can be conducted as low-intensity continuous training (LICT) or a variety of higher intensity work/rest formats, collectively called interval training. Interval training was developed for athletes in the early 20th century. It was systemized in Sweden as Fartlek, and in Germany as die interval Method, in the 1930s. Most contemporary forms of interval training evolved from these progenitors. In essence, interval training allows a large volume of high-intensity or race specific training to be performed while controlling the development of fatigue. Adding interval training to LICT done by athletes adds about 2%-4% to performance achievable with LICT, which represents a competitively meaningful difference in performance (e.g., 4:25 vs. 4:00 over 1 mile). More recently, interval training has been applied to health- fitness participants and even to patients with health conditions. Studies indicate that a comparatively low volume of interval training can produce substantial improvement in physiologic capacity, in as little as 20% of training time versus LICT. There are data indicating that interval training can be reasonably pleasant, have good adherence, and is safe, even in patients. Although interval training was originally designed for athletics, the fundamental patterns of work versus recovery are remarkably similar in healthy adults and patients. Although the total volume of training and both absolute and relative intensity and magnitude of homeostatic disturbance are larger in athletes, the overall pattern of effort is the same in fitness participants and patients. Interval training can thus be characterized as an important step in the evolution of exercise training.

Responses to Exercise with Low Carbohydrate Availability on Muscle Glycogen and Cell Signaling: A Systematic Review and Meta-analysis

BACKGROUND

The growing interest in how exercise and carbohydrate (CHO) restriction may modify molecular responses that promote endurance adaptations has led to many interesting controversies.

OBJECTIVE

We conducted a systematic review and a meta-analysis regarding the effect of low-carbohydrate availability (LOW) pre-, during, or post-exercise, on the mRNA content of commonly measured genes involved in mitochondrial biogenesis (PGC-1α, TFAM mRNA) and metabolism (PDK4, UCP3 and GLUT4 mRNA), and on muscle glycogen levels, compared with a high-CHO (CON) condition.

METHODS

MEDLINE, Scopus, and Web of Science databases were searched following the PRISMA 2020 guidelines (with an end date of November 2023). In total, 19 randomized-controlled studies were considered for inclusion. We evaluated the methodological quality of all studies using the Cochrane Risk of Bias tool for randomized clinical studies. A meta-analysis was performed using a random effects model to calculate the standardized mean difference (SMD), estimated by Hedges' g, and 95% confidence intervals (CIs).

RESULTS

The LOW condition was associated with an increased mRNA content of several genes during the early recovery period post-exercise, such as PDK4 (SMD 1.61; 95% CI 0.80-2.42), GLUT4 (SMD 1.38; 95% CI 0.46-2.30), and UCP3 (SMD 2.05; 95% CI 0.40-3.69). However, overall, there was no significant effect on the mRNA content of PGC-1α or TFAM. Finally, CHO restriction and exercise significantly reduced muscle glycogen levels (SMD 3.69; 95% CI 2.82-5.09). A meta-analysis of subgroups from studies with a difference in muscle glycogen concentration of > 200 mmol kg dw-1 between the LOW and CON conditions showed an increase in exercise-induced PGC-1α mRNA (SMD 2.08; 95% CI 0.64-3.52; p = 0.005; I2 = 75%) and a greater effect in PDK4 and GLUT4 mRNA.

CONCLUSION

The meta-analysis results show that CHO restriction was associated with an increase in the exercise-induced mRNA content of PDK4, UCP3, and GLUT4, but not the exercise-induced mRNA content of PGC-1ɑ and TFAM. However, when there were substantial differences in glycogen depletion between CON and LOW CHO conditions (> 200 mmol kg dw-1), there was a greater effect of CHO restriction on the exercise-induced mRNA content of metabolic genes, and an increase in exercise-induced PGC-1α mRNA.

Age-related changes of skeletal muscle metabolic response to contraction are also sex-dependent

Mitochondria adapt to increased energy demands during muscle contraction by acutely altering metabolite fluxes and substrate oxidation. With age, an impaired mitochondrial metabolic response may contribute to reduced exercise tolerance and decreased skeletal muscle mass, specific force, increased overall fatty depositions in the skeletal muscle, frailty and depressed energy maintenance. We hypothesized that elevated energy stress in mitochondria with age alters the capacity of mitochondria to utilize different substrates following muscle contraction. To test this hypothesis, we used in vivo electrical stimulation to simulate high-intensity intervals (HII) or low intensity steady-state (LISS) exercise in young (5-7 months) and aged (27-29 months) male and female mice to characterize effects of age and sex on mitochondrial substrate utilization in skeletal muscle following contraction. Mitochondrial respiration using glutamate decreased in aged males following HII and glutamate oxidation was inhibited following HII in both the contracted and non-stimulated muscle of aged female muscle. Analyses of the muscle metabolome of female mice indicated that changes in metabolic pathways induced by HII and LISS contractions in young muscle are absent in aged muscle. To test improved mitochondrial function on substrate utilization following HII, we treated aged females with elamipretide (ELAM), a mitochondrially-targeted peptide shown to improve mitochondrial bioenergetics and restore redox status in aged muscle. ELAM removed inhibition of glutamate oxidation and showed increased metabolic pathway changes following HII, suggesting rescuing redox status and improving bioenergetic function in mitochondria from aged muscle increases glutamate utilization and enhances the metabolic response to muscle contraction in aged muscle. KEY POINTS: Acute local contraction of gastrocnemius can systemically alter mitochondrial respiration in non-stimulated muscle. Age-related changes in mitochondrial respiration using glutamate or palmitoyl carnitine following contraction are sex-dependent. Respiration using glutamate after high-intensity contraction is inhibited in aged female muscle. Metabolite level and pathway changes following muscle contraction decrease with age in female mice. Treatment with the mitochondrially-targeted peptide elamipretide can partially rescue metabolite response to muscle contraction.

The Therapeutic Potential of Physical Exercise in Cancer: The Role of Chemokines

The global increase in cancer cases and mortality has been associated with inflammatory processes, in which chemokines play crucial roles. These molecules, a subfamily of cytokines, are essential for the migration, adhesion, interaction, and positioning of immune cells throughout the body. Chemokines primarily originate in response to pathogenic stimuli and inflammatory cytokines. They are expressed by lymphocytes in the bloodstream and are divided into four classes (CC, CXC, XC, and CX3C), playing multifaceted roles in the tumor environment (TME). In the TME, chemokines regulate immune behavior by recruiting cells such as tumor-associated macrophages (TAMs) and myeloid-derived suppressor cells (MDSCs), which promote tumor survival. Additionally, they directly influence tumor behavior, promoting pathological angiogenesis, invasion, and metastasis. On the other hand, chemokines can also induce antitumor responses by mobilizing CD8+ T cells and natural killer (NK) cells to the tumor, reducing pro-inflammatory chemokines and enhancing essential antitumor responses. Given the complex interaction between chemokines, the immune system, angiogenic factors, and metastasis, it becomes evident how important it is to target these pathways in therapeutic interventions to counteract cancer progression. In this context, physical exercise emerges as a promising strategy due to its role modulating the expression of anti-inflammatory chemokines and enhancing the antitumor response. Aerobic and resistance exercises have been associated with a beneficial inflammatory profile in cancer, increased infiltration of CD8+ T cells in the TME, and improvement of intratumoral vasculature. This creates an environment less favorable to tumor growth and supports the circulation of antitumor immune cells and chemokines. Therefore, understanding the impact of exercise on the expression of chemokines can provide valuable insights for therapeutic interventions in cancer treatment and prevention.

Exercise, exerkines and exercise mimetic drugs: Molecular mechanisms and therapeutics

Chronic diseases linked with sedentary lifestyles and poor dietary habits are increasingly common in modern society. Exercise is widely acknowledged to have a plethora of health benefits, including its role in primary prevention of various chronic conditions like type 2 diabetes mellitus, obesity, cardiovascular disease, and several musculoskeletal as well as degenerative disorders. Regular physical activity induces numerous physiological adaptations that contribute to these positive effects, primarily observed in skeletal muscle but also impacting other tissues. There is a growing interest among researchers in developing pharmaceutical interventions that mimic the beneficial effects of exercise for therapeutic applications. Exercise mimetic medications have the potential to be helpful aids in enhancing functional outcomes for patients with metabolic dysfunction, neuromuscular and musculoskeletal disorders. Some of the potential targets for exercise mimetics include pathways involved in metabolism, mitochondrial function, inflammation, and tissue regeneration. The present review aims to provide an exhaustive overview of the current understanding of exercise physiology, the role of exerkines and biomolecular pathways, and the potential applications of exercise mimetic drugs for the treatment of several diseases.

The Impact of the Interactive Floor Device and Aerobic Training on Executive Functions in Children

BACKGROUND/OBJECTIVES

Considering the importance of physical activity on the development of cognitive functions in children, the aim of this study was to assess the effects of a ten-week training program using the Interactive Floor device (© Funtronic), i.e., a kinesthetic educational game, and aerobic activity training on executive functions in 9-year-old children. Given current knowledge of the advantages of gamification and on-task switching, stronger improvement was expected for the Interactive Floor device than aerobic exercise activities.

METHODS

Sixty-four children (29 boys/35 girls) were randomly assigned to the Interactive Floor (n = 22), Aerobic Training (n = 22), or Control groups (n = 20). The participants had their cognitive abilities assessed twice (pre- and post-intervention) using computer tests from the Vienna Test System (VTS) and subtests from the Wechsler Intelligence Scale for Children® Fifth Edition (WISC®-V). From VTS, the Stroop Test was used to measure inhibition and attentional control, while the Corsi Block test assessed visuospatial short-term working memory. To assess auditory working memory, the Digit Span subtest from the WISC®-V was applied. Additionally, fluid intelligence was estimated using Raven's Progressive Matrices.

RESULTS

Repeated-measures mixed ANOVA and post hoc tests with Bonferroni correction for multiple comparisons showed that all intervention program groups improved in terms of intelligence and non-verbal abstract reasoning. The second significant finding in this study was that especially children from the Interactive Floor group developed their executive functions, i.e., inhibition and attentional control as well as their spatial short-term memory capacity.

CONCLUSIONS

The results suggest that a combination of both physical exercise and cognitive games in the Interactive Floor group resulted in greater improvement in cognitive abilities in children than aerobic exercise or physical education lessons. It seems that a multidisciplinary approach combining physical and cognitive stimulation effectively promotes child development. Future programs aiming to improve cognitive skills in children should consider incorporating interactive and engaging activities that stimulate both the body and the mind.

Exercise training-induced speeding of V ˙ O 2 kinetics is not intensity domain-specific or correlated with indices of exercise performance

PURPOSE

This study examined the effect of 3 and 6 weeks of intensity domain-based exercise training onV ˙ O 2 kinetics changes and their relationship with indices of performance.

METHODS

Eighty-four young healthy participants (42 M, 42 F) were randomly assigned to six groups (14 participants each, age and sex-matched) consisting of: continuous cycling in the (1) moderate (MOD)-, (2) lower heavy (HVY1)-, and (3) upper heavy-intensity (HVY2)- domain; interval cycling in the (4) severe-intensity domain (i.e., high-intensity interval training (HIIT), or (5) extreme-intensity domain (i.e., sprint-interval training (SIT)); or (6) control (CON). Training participants completed two three-week phases of three supervised sessions per week, with physiological evaluations performed at PRE, MID and POST intervention. All training protocols, except SIT, were work-matched.

RESULTS

There was a significant time effect for the time constant ( τ V ˙ O 2 ) between PRE (31.6 ± 10.4 s) and MID (22.6 ± 6.9 s) (p < 0.05) and PRE and POST (21.8 ± 6.3 s) (p < 0.05), but no difference between MID and POST (p > 0.05) and no group or interaction effects (p > 0.05). There were no PRE to POST differences for CON (p < 0.05) in any variables. Despite significant increases in maximalV ˙ O 2 (V ˙ O 2max ), estimated lactate threshold (θLT), maximal metabolic steady state (MMSS), and peak power output (PPO) for the intervention groups (p < 0.05), there were no significant correlations from PRE to MID or MID to POST between Δ τ V ˙ O 2 and Δ V ˙ O 2max (r = - 0.221, r = 0.119), ΔPPO (r = - 0.112, r = - 0.017), ΔθLT (r = 0.083, r = 0.142) and ΔMMSS (r = - 0.213, r = 0.049)(p > 0.05).

CONCLUSION

This study demonstrated that (i) the rapid speeding ofV ˙ O 2 kinetics was not intensity-dependent; and (ii) changes in indices of performance were not significantly correlated with Δ τ V ˙ O 2 .

Exercise alleviates hematopoietic stem cell injury following radiation via the carnosine/Slc15a2-p53 axis

Ionizing radiation (IR) can cause severe dysfunction of hematopoietic stem cells (HSCs), leading to acute or prolonged myelosuppression. In recent years, physical exercise has been recognized as a healthy lifestyle as it can fight a variety of diseases. However, whether it provides protection against IR is not fully understood. In this study, we revealed that long-term moderate exercise mitigated IR-induced hematopoietic injury by generating carnosine from skeletal muscles. We found that exercised mice displayed reduced loss of HSC number and function after IR, accompanied by alleviated bone marrow damage. Interestingly, these effects were largely abrogated by specific deletion of carnosine synthase Carns1 in skeletal muscles. In contrast, carnosine treatment protected HSCs against IR-induced injury. Mechanistically, we demonstrated that exercise-generated carnosine was specifically transported to HSCs via Slc15a2 and then inhibited p53 transcriptional activity by directly interacting with its core DNA-binding domain, which led to downregulation of the p53 target genes p21 and Puma, thus promoting the proliferation and survival and inhibiting the senescence of irradiated HSCs. More importantly, a similar role of the carnosine/Slc15a2-p53 axis was observed in human cord blood-derived HSCs. Collectively, our data reveal that moderate exercise or carnosine supplementation may be potential antiradiation strategies.

Quantification of nutrient fluxes during acute exercise in mice

Despite the known metabolic benefits of exercise, an integrated metabolic understanding of exercise is lacking. Here, we use in vivo steady-state isotope-labeled infusions to quantify fuel flux and oxidation during exercise in fasted, fed, and exhausted female mice, revealing several novel findings. Exercise strongly promoted glucose fluxes from liver glycogen, lactate, and glycerol, distinct from humans. Several organs spared glucose, a process that broke down in exhausted mice despite concomitant hypoglycemia. Proteolysis increased markedly, also divergent from humans. Fatty acid oxidation dominated during fasted exercise. Ketone production and oxidation rose rapidly, seemingly driven by a hepatic bottleneck caused by gluconeogenesis-induced cataplerotic stress. Altered fuel consumption was observed in organs not directly involved in muscle contraction, including the pancreas and brown fat. Several futile cycles surprisingly persisted during exercise, despite their energy cost. In sum, we provide a comprehensive, integrated, holistic, and quantitative accounting of metabolism during exercise in an intact organism.

Muscle-brain crosstalk mediated by exercise-induced myokines - insights from experimental studies

Over the past couple of decades, it has become apparent that skeletal muscles might be engaged in endocrine signaling, mostly as a result of exercise or physical activity in general. The importance of this phenomenon is currently studied in terms of the impact that exercise- or physical activity -induced signaling factors have, in the interaction of the "muscle-brain crosstalk." So far, skeletal muscle-derived myokines were demonstrated to intercede in the connection between muscles and a plethora of various organs such as adipose tissue, liver, or pancreas. However, the exact mechanism of muscle-brain communication is yet to be determined. It is speculated that, in particular, brain-derived neurotrophic factor (BDNF), irisin, cathepsin B (CTSB), interleukin 6 (IL-6), and insulin-like growth factor-1 (IGF-1) partake in this crosstalk by promoting neuronal proliferation and synaptic plasticity, also resulting in improved cognition and ameliorated behavioral alterations. Researchers suggest that myokines might act directly on the brain parenchyma via crossing the blood-brain barrier (BBB). The following article reviews the information available regarding rodent studies on main myokines determined to cross the BBB, specifically addressing the association between exercise-induced myokine release and central nervous system (CNS) impairments. Although the hypothesis of skeletal muscles being critical sources of myokines seems promising, it should not be forgotten that the origin of these factors might vary, depending on the cell types engaged in their synthesis. Limited amount of research providing information on alterations in myokines expression in various organs at the same time, results in taking them only as circumstantial evidence on the way to determine the actual involvement of skeletal muscles in the overall state of homeostasis. The following article reviews the information available regarding rodent studies on main myokines determined to cross the BBB, specifically addressing the association between exercise-induced myokine release and CNS impairments.

Vgll2 as an integrative regulator of mitochondrial function and contractility specific to skeletal muscle

During skeletal muscle adaptation to physiological or pathophysiological signals, contractile apparatus and mitochondrial function are coordinated to alter muscle fiber type. Although recent studies have identified various factors involved in modifying contractile proteins and mitochondrial function, the molecular mechanisms coordinating contractile and metabolic functions during muscle fiber transition are not fully understood. Using a gene-deficient mouse approach, our previous studies uncovered that vestigial-like family member 2 (Vgll2), a skeletal muscle-specific transcription cofactor activated by exercise, is essential for fast-to-slow adaptation of skeletal muscle. The current study provides evidence that Vgll2 plays a role in increasing muscle mitochondrial mass and oxidative capacity. Transgenic Vgll2 overexpression in mice altered muscle fiber composition toward the slow type and enhanced exercise endurance, which contradicted the outcomes observed with Vgll2 deficiency. Vgll2 expression was positively correlated with the expression of genes related to mitochondrial function in skeletal muscle, mitochondrial DNA content, and protein abundance of oxidative phosphorylation complexes. Additionally, Vgll2 overexpression significantly increased the maximal respiration of isolated muscle fibers and enhanced the suppressive effects of endurance training on weight gain. Notably, no additional alteration in expression of myosin heavy chain genes was observed after exercise, suggesting that Vgll2 plays a direct role in regulating mitochondrial function, independent of its effect on contractile components. The observed increase in exercise endurance and metabolic efficiency may be attributed to the acute upregulation of genes promoting fatty acid utilization as a direct consequence of Vgll2 activation facilitated by endurance exercise. Thus, the current study establishes that Vgll2 is an integrative regulator of mitochondrial function and contractility in skeletal muscle.

Effect of an endothelial regulatory module on plasma proteomics in exercising horses

Elite performing exercise requires an intricate modulation of the blood pressure to support the working muscles with oxygen. We have previously identified a genomic regulatory module that associates with differences in blood pressures of importance for elite performance in racehorses. This study aimed to determine the effect of the regulatory module on the protein repertoire. We sampled plasma from 12 Coldblooded trotters divided into two endothelial regulatory module haplotype groups, a sub-elite performing haplotype (SPH) and an elite performing haplotype (EPH), each at rest and exercise. The haplotype groups and their interaction were interrogated in two analyses, i) individual paired ratio analysis for identifying differentially abundant proteins of exercise (DAPE) and interaction (DAPI) between haplotype and exercise, and ii) unpaired ratio analysis for identifying differentially abundant protein of haplotype (DAPH). The proteomics analyses revealed a widespread change in plasma protein content during exercise, with a decreased tendency in protein abundance that is mainly related to lung function, tissue fluids, metabolism, calcium ion pathway and cellular energy metabolism. Furthermore, we provide the first investigation of the proteome variation due to the interaction between exercise and related blood pressure haplotypes, which this difference was related to a faster switch to the lipoprotein and lipid metabolism during exercise for EPH. The molecular signatures identified in the present study contribute to an improved understanding of exercise-related blood pressure regulation.

Impact of Physical Activity on Cellular Metabolism Across Both Neurodegenerative and General Neurological Conditions: A Narrative Review

BACKGROUND

Regular physical activity plays a crucial role in modulating cellular metabolism and mitigating the progression of neurodegenerative diseases such as Alzheimer's, Parkinson's, and Multiple Sclerosis.

OBJECTIVE

The objective of this review is to evaluate the molecular mechanisms by which exercise influences cellular metabolism, with a focus on its potential as a therapeutic intervention for neurological disorders.

METHODS

A comprehensive literature review was conducted using peer-reviewed scientific articles, with a focus on the period between 2015 and 2024, to analyze the effects of exercise on mitochondrial function, oxidative stress, and metabolic health.

RESULTS

The findings indicate that exercise promotes mitochondrial biogenesis, enhances oxidative phosphorylation, and reduces reactive oxygen species, contributing to improved energy production and cellular resilience. These metabolic adaptations are associated with delayed disease progression and reduced symptoms in patients with neurodegenerative conditions. Additionally, integrating exercise with nutritional strategies may further enhance therapeutic outcomes by addressing metabolic disturbances comprehensively.

CONCLUSIONS

This review concludes that personalized exercise protocols should be developed to optimize metabolic benefits for patients with neurological diseases, while future research should focus on biomarker development for individualized treatment approaches. These findings highlight the importance of non-pharmacological interventions in managing neurodegenerative diseases.

The repeated bout effect evokes the training-induced skeletal muscle cellular memory

Physical exercise is well-established as beneficial for health. With the 20th-century epidemiological transition, promoting healthy habits like exercise has become crucial for preventing chronic diseases. Stress can yield adaptive long-term benefits, potentially transmitted trans-generationally. Physical training exposes individuals to metabolic, thermal, mechanical, and oxidative stressors, activating cell signaling pathways that regulate gene expression and adaptive responses, thereby enhancing stress tolerance - a phenomenon known as hormesis. Muscle memory is the capacity of skeletal muscle to respond differently to environmental stimuli in an adaptive (positive) or maladaptive (negative) manner if the stimuli have been encountered previously. The Repeated Bout Effect encompasses our skeletal muscle capacity to activate an intrinsic protective mechanism that reacts to eccentric exercise-induced damage by activating an adaptive response that resists subsequent damage stimuli. Deciphering the molecular mechanism of this phenomenon would allow the incorporation of muscle memory in training programs for professional athletes, active individuals looking for the health benefits of exercise training, and patients with "exercise intolerance." Moreover, enhancing the adaptive response of muscle memory could promote healing in individuals who traditionally do not recover after immobilization. The improvement could be part of an exercise program but could also be targeted pharmacologically. This review explores Repeated Bout Effect mechanisms: neural adaptations, tendon and muscle fiber property changes, extracellular matrix remodeling, and improved inflammatory responses.

Quantifying the Enhancement of Sarcopenic Skeletal Muscle Preservation Through a Hybrid Exercise Program: Randomized Controlled Trial

Background

Sarcopenia is characterized by the loss of skeletal muscle mass and muscle function with increasing age. The skeletal muscle mass of older people who endure sarcopenia may be improved via the practice of strength training and tai chi. However, it remains unclear if the hybridization of strength exercise training and traditional Chinese exercise will have a better effect.

Objective

We designed a strength training and tai chi exercise hybrid program to improve sarcopenia in older people. Moreover, explainable artificial intelligence was used to predict postintervention sarcopenic status and quantify the feature contribution.

Methods

To assess the influence of sarcopenia in the older people group, 93 participated as experimental participants in a 24-week randomized controlled trial and were randomized into 3 intervention groups, namely the tai chi exercise and strength training hybrid group (TCSG; n=33), the strength training group (STG; n=30), and the control group (n=30). Abdominal computed tomography was used to evaluate the skeletal muscle mass at the third lumbar (L3) vertebra. Analysis of demographic characteristics of participants at baseline used 1-way ANOVA and χ2 tests, and repeated-measures ANOVA was used to analyze experimental data. In addition, 10 machine-learning classification models were used to calculate if these participants could reverse the degree of sarcopenia after the intervention.

Results

A significant interaction effect was found in skeletal muscle density at the L3 vertebra, skeletal muscle area at the L3 vertebra (L3 SMA), grip strength, muscle fat infiltration, and relative skeletal muscle mass index (all P values were <.05). Grip strength, relative skeletal muscle mass index, and L3 SMA were significantly improved after the intervention for participants in the TCSG and STG (all P values were <.05). After post hoc tests, we found that participants in the TCSG experienced a better effect on L3 SMA than those in the STG and participants in the control group. The LightGBM classification model had the greatest performance in accuracy (88.4%), recall score (74%), and F1-score (76.1%).

Conclusions

The skeletal muscle area of older adults with sarcopenia may be improved by a hybrid exercise program composed of strength training and tai chi. In addition, we identified that the LightGBM classification model had the best performance to predict the reversion of sarcopenia.

Physical Activity and All-Cause Mortality by Age in 4 Multinational Megacohorts

Importance

Physical activity (PA) guidelines recommend the same amount of PA through adulthood to live longer.

Objective

To explore whether there is an age-dependent association between PA and all-cause mortality and to investigate the age-dependent associations between other modifiable health factors (high educational level, not smoking, not regularly consuming alcohol, healthy body weight, and living without hypertension and diabetes) and mortality.

Design, Setting, and Participants

This cohort study used a pooled analysis of 4 population-based prospective cohorts (National Health Interview Survey, 1997-2018; UK Biobank, 2006-2010; China Kadoorie Biobank, 2004-2008; and Mei Jau, 1997-2016). Data were analyzed from June 2022 to September 2024.

Exposures

Self-reported leisure-time PA.

Main Outcomes and Measures

The primary outcome was deaths identified through follow-up linkage to national death registries. Analyses were performed for the total sample and by age groups (20-29, 30-39, 40-49, 50-59, 60-69, 70-79, and ≥80 years). Cox proportional hazards regression models with stratification by study were used to calculate mortality hazard ratios and their 95% CIs for the pooled dataset and by age group.

Results

A heterogeneous sample of 2 011 186 individuals (mean [SD] age, 49.1 [14.3] years; age range, 20-97 years; 1 105 581 women [55.0%]) were included. After a median (IQR) follow-up of 11.5 (9.3-13.5) years, 177 436 deaths occurred. The association between PA and mortality in the total sample showed a nonlinear dose-response pattern, but age modified this association (P for interaction <.001); PA was consistently associated with a lower risk of mortality across all age groups, but the reduction in risk was greater in older vs younger age groups, especially at high levels of PA. The hazard ratio for mortality associated with meeting the recommended PA in the total sample was 0.78 (95% CI, 0.77-0.79). This inverse association between meeting PA recommendations and mortality was somewhat greater as age increased (P for interaction <.001). Age also modified the associations of the other modifiable health factors with mortality (all P for interaction <.001), but the magnitude of associations was greater in younger vs older age groups.

Conclusions and Relevance

In this pooled analysis of cohort studies, the association between PA and mortality risk remained consistent across the adult lifespan, which contrasts with other modifiable health factors, for which associations with mortality risk diminished with age. Given these findings, the promotion of regular PA is essential at all stages of adult life.

Interleukin 15: A new intermediary in the effects of exercise and training on skeletal muscle and bone function

Interleukin-15 (IL-15), a pro-inflammatory cytokine, is produced mainly by skeletal muscle cells, macrophages and epithelial cells. Recent research has demonstrated that IL-15 is closely related to the functions of bone and skeletal muscle in the locomotor system. There is growing evidence that exercise, an important means to regulate the immune and locomotor systems, influences IL-15 content in various tissues, thereby indirectly affecting the function of bones and muscles. Furthermore, the form, intensity, and duration of exercise determine the degree of change in IL-15 and downstream effects. This paper reviews the structure, synthesis and secretion of IL-15, the role of IL-15 in regulating the metabolism of bone tissue cells and myofibers through binding to the IL-15 receptor-α (IL-15Rα), and the response of IL-15 to different types of exercise. This review provides a reference for further analyses of the role and mechanism of action of IL-15 in the regulation of metabolism during exercise.

Mechanism of metabolic memory: progression in diabetic nephropathy—a descriptive review

Diabetes mellitus and its complications exploit significantly impact global human well-being and economic burden. Previous studies and clinical trials have provided insights into the concept of metabolic memory, which sustains even after hyperglycemia has been resolved, causing diabetic complications completely. The term “metabolic memory” refers to the body’s abnormal metabolism, which can have long-term effects and influence both health and disease conditions. It involves various molecular processes causing cellular shifts, tissue and organ dysfunctions, disease progression, and effects on offspring. The conceptual framework of metabolic memory is defined and strengthened, offering a comprehensive understanding of the underlying causes of diabetic nephropathy (DN) and providing a potential new approach for diagnosing and treating the disease. In this review, we elucidated the importance, characteristics, cellular and molecular importance, and therapeutic intervention to eradicate metabolic memory in DN once hyperglycemia has been eliminated. The regulation of metabolic memory is assisted based on an epigenetic mechanism. Therefore, this report traces the significant factors involved in regulating epigenetic modifications such as DNA methylation, histone modification, and chromatin remodeling. This mechanism significantly triggers epigenetic regulation, leading to glucose stress, oxidative stress induction, and apoptosis, causing DN. It occurs beyond various signaling cascades, resulting in alterations in transcription factors and receptor molecules, which enhance the metabolic memory in the post-sustenance of hyperglycemia. This condition can be modulated based on therapeutic interventions involving lifestyle modification and the inclusion of natural substances like bioactive compounds, polyphenols, and terpenoids in the diet, followed by medications acting as epigenetic modifiers.

The Variability of the Salivary Antimicrobial Peptide Profile: Impact of Lifestyle

Saliva is crucial in maintaining oral health; its composition reflects the body's physiological and diseased state. Among salivary components, antimicrobial peptides (AMPs) stand out for their broad antimicrobial activities and role in modulating the oral microbiota and innate immune response. Local and systemic diseases can affect the levels of AMPs in saliva, making them attractive biomarkers. However, the large variability in their concentrations hampers their use in diagnostics. Knowledge of the various factors influencing the profile of salivary AMPs is essential for their use as biomarkers. Here, we examine how lifestyle factors such as physical activity, dietary supplementation, tobacco smoking, and psychological stress impact salivary AMP levels. By understanding these sources of variability, we can take a step forward in using AMPs for diagnostics and prognostics and develop new tailored and preventative approaches.