Skeletal muscle as a gene regulatory endocrine organ

Impact of magnetic resonance imaging-derived skeletal muscle index in locoregionally advanced nasopharyngeal carcinoma

PURPOSE

To evaluate the clinical implication of magnetic resonance imaging (MRI)-derived skeletal muscle index (SMI) in locoregionally advanced nasopharyngeal carcinoma (LANPC) patients undergoing induction chemotherapy (IC) followed by concurrent chemoradiotherapy (CCRT) and further to develop a nomogram for predicting survival prognosis.

METHODS

SMI was determined through baseline MRI at the third cervical level. The nomogram was based on a training cohort involving 409 LANPC patients. We validated the prognostic accuracy of this prognostic model in an internal validation cohort (n = 204) and an external independent cohort (n = 272).

RESULTS

SMI was an independent risk factor for OS. A prognostic model comprising age, TNM stage and SMI for individual survival prediction was developed and graphically represented as a nomogram. The model showed favorable discrimination (C-index: 0.686), predictive accuracy [time dependent area under the curve (tAUC) at 5 years: 0.70], and calibration, and was further validated in the internal and external validation datasets. A risk stratification derived from the model stratified these patients into three prognostic subgroups with significantly different survival.

CONCLUSIONS

Low SMI accessed by MRI was significantly associated with poor overall survival in LANPC patients undergoing IC + CCRT. Moreover, we established and validated a novel nomogram involving age, TNM stage and SMI that could provide accurate prognostic stratification among this population.

Effects of MicroRNAs and Long Non-coding RNAs on Beneficial Action of Exercise on Cognition in Degenerative Diseases: A Review

Recent research has exposed a growing body of proof underscoring the importance of microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) in maintaining the physical composition of neurons and influencing cognitive functioning in both standard and atypical circumstances. Extensive research has been conducted on the possible application of miRNAs and lncRNAs as biomarkers for various diseases, with a particular focus on brain disorders, as they possess remarkable durability in cell-free surroundings and can endure repeated freezing and thawing processes. It is intriguing to note that miRNAs and lncRNAs have the ability to function through paracrine mechanisms, thereby playing a role in communication between different organs. Recent research has proposed that the improvement of cognitive abilities through physical exercise in mentally healthy individuals is a valuable method for uncovering potential connections between miRNAs, or microRNAs, and lncRNAs, and human cognitive function. The process of cross-correlating data from disease models and patients with existing data will be crucial in identifying essential miRNAs and lncRNAs, which can potentially act as biomarkers or drug targets in the treatment of cognitive disorders. By combining this method with additional research in animal models, we can determine the function of these molecules and their potential impact on therapy. This article discusses the latest research about the primary miRNAs, lncRNAs, and their exosomes that are affected by physical activity in terms of human cognitive function.

Sarcopenia: A dive into metabolism to promote a multimodal, preventive, and regenerative approach

Sarcopenia, the age-related loss of skeletal muscle mass and function, poses a significant challenge in the field of geriatrics and gerontology, impacting the health and independence of older adults. Understanding and addressing sarcopenia is crucial for optimizing clinical outcomes and enhancing the quality of life along with aging. By synthesizing current research findings and theoretical frameworks, this review elucidates the multifaceted mechanisms underlying sarcopenia, mainly focusing on energy balance and metabolic processes. Furthermore, the manuscript explores the implications of sarcopenia on overall health outcomes, functional decline, and quality of life in older individuals. The study concludes with a perspective on the role of preventive and regenerative medicine in sarcopenia, where the two main lifestyle pillars (exercise and diet) represent key factors.

The effects of myosteatosis on skeletal muscle function in older adults

Myosteatosis, or the infiltration of fatty deposits into skeletal muscle, occurs with advancing age and contributes to the health and functional decline of older adults. Myosteatosis and its inflammatory milieu play a larger role in adipose tissue dysfunction, muscle tissue dysfunction, and increased passive muscle stiffness. Combined with the age-related decline of sex hormones and development of anabolic resistance, myosteatosis also contributes to insulin resistance, impaired muscle mechanics, loss of force production from the muscle, and increased risk of chronic disease. Due to its highly inflammatory secretome and the downstream negative effects on muscle metabolism and mechanics, myosteatosis has become an area of interest for aging researchers and clinicians. Thus far, myosteatosis treatments have had limited success, as many lack the potency to completely rescue the metabolic and physical consequences of myosteatosis. Future research is encouraged for the development of reliable assessment methods for myosteatosis, as well as the continued exploration of pharmacological, nutritional, and exercise-related interventions that may lead to the success in attenuating myosteatosis and its clinical consequences within the aging population.

Binge drinking leads to an oxidative and metabolic imbalance in skeletal muscle during adolescence in rats: endocrine repercussion

Binge drinking (BD) is an especially pro-oxidant model of alcohol consumption, mainly used by adolescents. It has recently been related to the hepatic IR-process. Skeletal muscle is known to be involved in insulin action and modulation through myokine secretion. However, there is no information on muscle metabolism and myokine secretion after BD exposure in adolescents. Two experimental groups of adolescent rats have been used: control and BD-exposed one. Oxidative balance, energy status and lipid, and protein metabolism have been analyzed in muscle, together with myokine serum levels (IL-6, myostatin, LIF, IL-5, fractalkine, FGF21, irisin, BDNF, FSTL1, apelin, FABP3, osteocrin, osteonectin (SPARC), and oncostatin). In muscle, BD affects the antioxidant enzyme balance leading to lipid and protein oxidation. Besides, it also increases the activation of AMPK and thus contributes to decrease SREBP1 and pmTOR and to increase FOXO3a expressions, promoting lipid and protein degradation. These alterations deeply affect the myokine secretion pattern. This is the first study to examine a general myokine response after exposure to BD. BD not only caused a detrimental imbalance in myokines related to muscle turnover, decreased those contributing to increase IR-process, decreased FST-1 and apelin and their cardioprotective function but also reduced the neuroprotective BDNF. Consequently, BD leads to an important metabolic and energetic disequilibrium in skeletal muscle, which contributes to exacerbate a general IR-process.

Study protocol: Identification and validation of integrative biomarkers of physical activity level and health in children and adolescents (INTEGRActiv)

Background

Physical activity (PA) provides health benefits across the lifespan and improves many established cardiovascular risk factors that have a significant impact on overall mortality. However, discrepancies between self-reported and device-based measures of PA make it difficult to obtain consistent results regarding PA and its health effects. Moreover, PA may produce different health effects depending on the type, intensity, duration, and frequency of activities and individual factors such as age, sex, body weight, early life conditions/exposures, etc. Appropriate biomarkers relating the degree of PA level with its effects on health, especially in children and adolescents, are required and missing. The main objective of the INTEGRActiv study is to identify novel useful integrative biomarkers of PA and its effects on the body health in children and adolescents, who represent an important target population to address personalized interventions to improve future metabolic health.

Methods/design

The study is structured in two phases. First, biomarkers of PA and health will be identified at baseline in a core cohort of 180 volunteers, distributed into two age groups: prepubertal (n = 90), and postpubertal adolescents (n = 90). Each group will include three subgroups (n = 30) with subjects of normal weight, overweight, and obesity, respectively. Identification of new biomarkers will be achieved by combining physical measures (PA and cardiorespiratory and muscular fitness, anthropometry) and molecular measures (cardiovascular risk factors, endocrine markers, cytokines and circulating miRNA in plasma, gene expression profile in blood cells, and metabolomics profiling in plasma). In the second phase, an educational intervention and its follow-up will be carried out in a subgroup of these subjects (60 volunteers), as a first validation step of the identified biomarkers.

Discussion

The INTEGRActiv study is expected to provide the definition of PA and health-related biomarkers (PA-health biomarkers) in childhood and adolescence. It will allow us to relate biomarkers to factors such as age, sex, body weight, sleep behavior, dietary factors, and pubertal status and to identify how these factors quantitatively affect the biomarkers' responses. Taken together, the INTEGRActiv study approach is expected to help monitor the efficacy of interventions aimed to improve the quality of life of children/adolescents through physical activity.

Clinical Trial Registration

ClinicalTrials.gov, Identifier NCT05907785.

The Developmental Implications of Muscle-Targeted Magnetic Mitohormesis: A Human Health and Longevity Perspective

Muscle function reflects muscular mitochondrial status, which, in turn, is an adaptive response to physical activity, representing improvements in energy production for de novo biosynthesis or metabolic efficiency. Differences in muscle performance are manifestations of the expression of distinct contractile-protein isoforms and of mitochondrial-energy substrate utilization. Powerful contractures require immediate energy production from carbohydrates outside the mitochondria that exhaust rapidly. Sustained muscle contractions require aerobic energy production from fatty acids by the mitochondria that is slower and produces less force. These two patterns of muscle force generation are broadly classified as glycolytic or oxidative, respectively, and require disparate levels of increased contractile or mitochondrial protein production, respectively, to be effectively executed. Glycolytic muscle, hence, tends towards fibre hypertrophy, whereas oxidative fibres are more disposed towards increased mitochondrial content and efficiency, rather than hypertrophy. Although developmentally predetermined muscle classes exist, a degree of functional plasticity persists across all muscles post-birth that can be modulated by exercise and generally results in an increase in the oxidative character of muscle. Oxidative muscle is most strongly correlated with organismal metabolic balance and longevity because of the propensity of oxidative muscle for fatty-acid oxidation and associated anti-inflammatory ramifications which occur at the expense of glycolytic-muscle development and hypertrophy. This muscle-class size disparity is often at odds with common expectations that muscle mass should scale positively with improved health and longevity. Brief magnetic-field activation of the muscle mitochondrial pool has been shown to recapitulate key aspects of the oxidative-muscle phenotype with similar metabolic hallmarks. This review discusses the common genetic cascades invoked by endurance exercise and magnetic-field therapy and the potential physiological differences with regards to human health and longevity. Future human studies examining the physiological consequences of magnetic-field therapy are warranted.

Are inflammatory markers associated with sarcopenia-related traits in older adults with sarcopenia? - A cross-sectional analysis of the ENHANce study

AIMS

To explore the relationship between inflammatory markers and sarcopenia-related traits in sarcopenic older adults.

METHODS

Baseline data of the ongoing Exercise and Nutrition for Healthy AgeiNg (ENHANce) study were used for a secondary, exploratory, cross-sectional analysis. ENHANce is a 5-armed triple blinded randomized controlled trial, in older adults (>65y) with sarcopenia defined according to the revised criteria of the European Working Group of Sarcopenia in Older People (EWGSOP2) aiming to assess the effect of combined anabolic interventions (protein supplement, omega-3 supplement and physical exercise) on physical performance, compared to single/placebo interventions. Inflammatory markers C-reactive protein (hs-CRP), albumin, interleukin-1β (IL-1β), IL-6, IL-8, and tumour necrosis factor-α (TNF-α) were assessed at baseline. Spearman's rho (ρ) correlation coefficients were calculated to associate these inflammatory markers with baseline sarcopenia-defining parameters (handgrip strength, chair stand test, appendicular lean mass [aLM], gait speed, Short Physical Performance Battery), physical activity (step count) and quality of life (SF-36, SarQoL).

RESULTS

We included 40 sarcopenic subjects (15 men/25 women, age 77.1 ± 6.8 years). Contrary to expectations, the pro-inflammatory IL-1β correlated positively with handgrip strength (ρ: 0.376; p = 0.024) and IL-6 with aLM (ρ: 0.334; p = 0.0433). IL-6 inversely correlated with step count (ρ:-0.358; p = 0.048). Subgroup analysis revealed important gender differences. IL-8 inversely correlated with handgrip strength in women (ρ: -0.425; p = 0.034) but not in men. In contrast, pro-inflammatory cytokines CRP (ρ: -0.615; p = 0.019), IL-6 (ρ: -0.604; p = 0.029) and TNF-α (ρ: -0.615; p = 0.025) inversely correlated with the SF-36 physical component score in men but not in women.

CONCLUSION

Although Inflammageing might play a role in sarcopenia-related traits, this exploratory study highlights an important role of gender. Future research should take this into account when elucidating the Inflammageing-sarcopenia interplay.

Association of muscle wasting with mortality risk among adults: A systematic review and meta-analysis of prospective studies

The relationship between muscle wasting and mortality risk in the general population remains unclear. Our study was conducted to examine and quantify the associations between muscle wasting and all-cause and cause-specific mortality risks. PubMed, Web of Science and Cochrane Library were searched until 22 March 2023 for main data sources and references of retrieved relevant articles. Prospective studies investigating the associations of muscle wasting with risks of all-cause and cause-specific mortality in the general population were eligible. A random-effect model was used to calculate the pooled relative risk (RR) and 95% confidence intervals (CIs) for the lowest versus normal categories of muscle mass. Subgroup analyses and meta-regression were performed to investigate the potential sources of heterogeneities among studies. Dose-response analyses were conducted to evaluate the relationship between muscle mass and mortality risk. Forty-nine prospective studies were included in the meta-analysis. A total of 61 055 deaths were ascertained among 878 349 participants during the 2.5- to 32-year follow-up. Muscle wasting was associated with higher mortality risks of all causes (RR = 1.36, 95% CI, 1.28 to 1.44, I²  = 94.9%, 49 studies), cardiovascular disease (CVD) (RR = 1.29, 95% CI, 1.05 to 1.58, I²  = 88.1%, 8 studies), cancer (RR = 1.14, 95% CI, 1.02 to 1.27, I²  = 38.7%, 3 studies) and respiratory disease (RR = 1.36, 95% CI, 1.11 to 1.67, I²  = 62.8%, 3 studies). Subgroup analyses revealed that muscle wasting, regardless of muscle strength, was significantly associated with a higher all-cause mortality risk. Meta-regression showed that risks of muscle wasting-related all-cause mortality (P = 0.06) and CVD mortality (P = 0.09) were lower in studies with longer follow-ups. An approximately inverse linear dose-response relationship was observed between mid-arm muscle circumference and all-cause mortality risk (P < 0.01 for non-linearity). Muscle wasting was associated with higher mortality risks of all causes, CVD, cancer and respiratory disease in the general population. Early detection and treatment for muscle wasting might be crucial for reducing mortality risk and promoting healthy longevity.

Myokine, a key cytokine for physical exercise to alleviate sarcopenic obesity

Skeletal muscle has a robust endocrine function as a powerful organ and can secrete and release cytokines or polypeptides known as myokines. These myokines have significant regulatory effects on signal transduction in skeletal muscle and the metabolism of peripheral tissues and organs and exert biological effects via autocrine, paracrine, or endocrine forms. Obesity and aging cause myokine secretion dysregulation, and hastening sarcopenic obesity (SO) development. Exercise is currently an excellent intervention and prevention method for SO. Meanwhile, exercise impacts many organs and tissues. These organs and tissues will produce various myokines in response to movement and metabolism throughout the body to govern muscle differentiation, growth, and remodeling. According to accumulating data, exercise can increase the release of myokines from diverse tissues into the blood and postpone the SO onset and progression by influencing protein metabolism, inflammation, mitochondrial quality control, and other mechanisms.

An Overview of Inter-Tissue and Inter-Kingdom Communication Mediated by Extracellular Vesicles in the Regulation of Mammalian Metabolism

Obesity and type 2 diabetes are associated with defects of insulin action in different tissues or alterations in β-cell secretory capacity that may be triggered by environmental challenges, inadequate lifestyle choices, or an underlying genetic predisposition. In addition, recent data shows that obesity may also be caused by perturbations of the gut microbiota, which then affect metabolic function and energy homeostasis in the host. Maintenance of metabolic homeostasis in complex organisms such as mammals requires organismal-level communication, including between the different organs and the gut microbiota. Extracellular vesicles (EVs) have been identified in all domains of life and have emerged as crucial players in inter-organ and inter-kingdom crosstalk. Interestingly, EVs found in edible vegetables or in milk have been shown to influence gut microbiota or tissue function in mammals. Moreover, there is a multidirectional crosstalk mediated by EVs derived from gut microbiota and body organs that has implications for host health. Untangling this complex signaling network may help implement novel therapies for the treatment of metabolic disease.

Effects of the exercise-inducible myokine irisin on proliferation and malignant properties of ovarian cancer cells through the HIF-1 α signaling pathway

Exercise has been shown to be associated with reduced risk and improving outcomes of several types of cancers. Irisin -a novel exercise-related myokine- has been proposed to exert beneficial effects in metabolic disorders including cancer. No previous studies have investigated whether irisin may regulate malignant characteristics of ovarian cancer cell lines. In the present study, we aimed to explore the effect of irisin on viability and proliferation of ovarian cancer cells which was examined by MTT assay. Then, we evaluated the migratory and invasive abilities of the cells via transwell assays. Moreover, the percentage of apoptosis induction was determined by flow cytometry. Furthermore, the mRNA expression level of genes related to the aerobic respiration (HIF-1α, c-Myc, LDHA, PDK1 and VEGF) was detected by real-time PCR. Our data revealed that irisin treatment significantly attenuated the proliferation, migration and invasion of ovarian cancer cells. Additionally, irisin induced apoptosis in ovarian cancer cells. We also observed that irisin regulated the expression of genes involved in aerobic respiration of ovarian cancer cells. Our results indicated that irisin may play a crucial role in inhibition of cell growth and malignant characteristics of ovarian cancer. These findings may open up avenues for future studies to identify the further therapeutic use of irisin in ovarian cancer management.

The impact of supervised physical exercise on chemokines and cytokines in recovered COVID-19 patients

COVID-19 is an infectious disease caused by the SARS-CoV-2 virus, which induces a high release of pro-inflammatory chemokines and cytokines, leading to severe systemic disorders. Further, evidence has shown that recovered COVID-19 patients still have some symptoms and disorders from COVID-19. Physical exercise can have many health benefits. It is known to be a potent regulator of the immune system, which includes frequency, intensity, duration, and supervised by a professional. Given the confinement and social isolation or hospitalization of COVID-19 patients, the population became sedentary or opted for physical exercise at home, assuming the guarantee of the beneficial effects of physical exercise and reducing exposure to SARS-CoV-2. This study aimed to investigate the effects of a supervised exercise protocol and a home-based unsupervised exercise protocol on chemokine and cytokine serum levels in recovered COVID-19 patients. This study was a prospective, parallel, two-arm clinical trial. Twenty-four patients who had moderate to severe COVID-19 concluded the intervention protocols of this study. Participants were submitted to either supervised exercise protocol at the Clinical Hospital of the Federal University of Pernambuco or home-based unsupervised exercise for 12 weeks. We analyzed serum levels of chemokines (CXCL8/IL-8, CCL5/RANTES, CXCL9/MIG, CCL2/MCP-1, and CXCL10/IP-10) and cytokines (IL-2, IL-4, IL-6, IL-10, IL-17A, TNF-α, and IFN-γ). Before the interventions, no significant differences were observed in the serum levels of chemokines and cytokines between the supervised and home-based unsupervised exercise groups. The CXCL8/IL-8 (p = 0.04), CCL2/MCP-1 (p = 0.03), and IFN-γ (p = 0.004) levels decreased after 12 weeks of supervised exercise. In parallel, an increase in IL-2 (p = 0.02), IL-6 (p = 0.03), IL-4 (p = 0.006), and IL-10 (p = 0.04) was observed after the supervised protocol compared to pre-intervention levels. No significant differences in all the chemokines and cytokines were found after 12 weeks of the home-based unsupervised exercise protocol. Given the results, the present study observed that supervised exercise was able to modulate the immune response in individuals with post-COVID-19, suggesting that supervised exercise can mitigate the inflammatory process associated with COVID-19 and its disorders.

Clinical trial registration

https://ensaiosclinicos.gov.br/rg/RBR-7z3kxjk, identifier U1111-1272-4730.

PHYSICAL HEALTH OF FEMALES FROM THE MOUNTAIN DISTRICTS OF ZAKARPATTIA ACCORDING TO THE METABOLIC LEVEL OF AEROBIC AND ANAEROBIC ENERGY SUPPLY DEPENDING ON THE COMPONENT BODY COMPOSITION

OBJECTIVE

Aim: To determine the aerobic and anaerobic productivity of females from the mountain districts of Zakarpattia region, depending on the component composition of body weight.

PATIENTS AND METHODS

Materials and Methods: A comparative analysis of physical health status of females in the post-pubertal period of ontogenesis, was carried out. Physical health status was assessed by indicators of aerobic and anaerobic productivity depending on the component composition of the body, which was determined by impedance measurement.

RESULTS

Results: Physical health of females from the mountain districts depends on the component composition of the body, namely: an excellent level of aerobic productivity is observed in females who have a insufficient body weight with a normal relative fat content and a high relative content of skeletal muscles, VО2 max rel > 38 ml·min-1·kg-1; as a result, their physical health exceeds the "critical level" according to H.L. Apanasenko and corresponds to "excellent" according to Ya.P. Pyarnat's criteria. Females from the mountain districts with normal body weight, high relative fat and normal relative skeletal muscle have average level of aerobic performance., i.e., VО2 max rel. is within 28-33 ml∙min-1∙kg-1. As a result, their physical health is below the "critical level".

CONCLUSION

Conclusions: "Excellent" and "good" level of aerobic productivity of females from the mountain districts of the Zakarpattia region guarantees "safe health level". Females from mountain districts with a high content of fat component have an "average" level of aerobic performance, which does not provide a "safe health level".

Skeletal Muscle's Role in Prenatal Inter-organ Communication: A Phenogenomic Study with Qualitative Citation Analysis

Gene targeting in mice allows for a complete elimination of skeletal (striated or voluntary) musculature in the body, from the beginning of its development, resulting in our ability to study the consequences of this ablation on other organs. Here I focus on the relationship between the muscle and lung, motor neurons, skeleton, and special senses. Since the inception of my independent laboratory, in 2000, with my team, we published more than 30 papers (and a book chapter), nearly 400 pages of data, on these specific relationships. Here I trace, using Web of Science, nearly 600 citations of this work, to understand its impact. The current report contains a summary of our work and its impact, NCBI's Gene Expression Omnibus accession numbers of all our microarray data, and three clear future directions doable by anyone using our publicly available data. Together, this effort furthers our understanding of inter-organ communication during prenatal development.

Irisin enhances longevity by boosting SIRT1, AMPK, autophagy and telomerase

Ageing is characterised by the accumulation of molecular and cellular damage through time, leading to a decline in physical and mental abilities. Currently, society has experienced a rapid increase in life expectancy, which has led to an increase in age-associated diseases. Therefore, it is crucial to study the process of ageing to guarantee the best conditions in the final stages of life. In recent years, interest has increased in a myokine known as irisin, which is secreted during physical exercise. This polypeptide hormone is produced by various organs, mainly muscle, and once it is released into the blood, it performs a wide variety of functions that are involved in metabolic control and may be relevant during some of the diseases associated with ageing. The aim of this review is to highlight the recent studies of irisin, such as its mechanism of expression, blood release, distribution, tissue target and participation in various cellular metabolic reactions and the relationship with key anti-ageing pathways such as adenosine monophosphate-activated protein kinase, silent information regulator T 1, autophagy and telomerase. In conclusion, irisin is a key player during the ageing process and it could be a novel target molecule for the therapeutic approach to boost longevity pathways. However, more research will be necessary to use this promising hormone for this gain.

Treatment with EV-miRNAs Alleviates Obesity-Associated Metabolic Dysfunction in Mice

Most cells release extracellular vesicles (EVs) that can be detected circulating in blood. We and others have shown that the microRNA contents of these vesicles induce transcriptomic changes in acceptor cells, contributing to the adjustment of metabolic homeostasis in response to environmental demands. Here, we explore the potential for modulating obesity- and exercise-derived EV-microRNAs to treat the metabolic dysfunction associated with obesity in mice. Treatment with EV-miRNAs alleviated glucose intolerance and insulin resistance in obese mice to an extent similar to that of high-intensity interval training, although only exercise improved cardiorespiratory fitness and decreased body weight. Mechanistically, EV-miRNAs decreased fatty acid and cholesterol biosynthesis pathways in the liver, reducing hepatic steatosis and increasing insulin sensitivity, resulting in decreased glycemia and triglyceridemia. Our data suggest that manipulation of EV-miRNAs may be a viable strategy to alleviate metabolic dysfunction in obese and diabetic patients who are unable to exercise, although actual physical activity is needed to improve cardiorespiratory fitness.

An Exercise-Induced Metabolic Shield in Distant Organs Blocks Cancer Progression and Metastatic Dissemination

Exercise prevents cancer incidence and recurrence, yet the underlying mechanism behind this relationship remains mostly unknown. Here we report that exercise induces the metabolic reprogramming of internal organs that increases nutrient demand and protects against metastatic colonization by limiting nutrient availability to the tumor, generating an exercise-induced metabolic shield. Proteomic and ex vivo metabolic capacity analyses of murine internal organs revealed that exercise induces catabolic processes, glucose uptake, mitochondrial activity, and GLUT expression. Proteomic analysis of routinely active human subject plasma demonstrated increased carbohydrate utilization following exercise. Epidemiologic data from a 20-year prospective study of a large human cohort of initially cancer-free participants revealed that exercise prior to cancer initiation had a modest impact on cancer incidence in low metastatic stages but significantly reduced the likelihood of highly metastatic cancer. In three models of melanoma in mice, exercise prior to cancer injection significantly protected against metastases in distant organs. The protective effects of exercise were dependent on mTOR activity, and inhibition of the mTOR pathway with rapamycin treatment ex vivo reversed the exercise-induced metabolic shield. Under limited glucose conditions, active stroma consumed significantly more glucose at the expense of the tumor. Collectively, these data suggest a clash between the metabolic plasticity of cancer and exercise-induced metabolic reprogramming of the stroma, raising an opportunity to block metastasis by challenging the metabolic needs of the tumor.

SIGNIFICANCE

Exercise protects against cancer progression and metastasis by inducing a high nutrient demand in internal organs, indicating that reducing nutrient availability to tumor cells represents a potential strategy to prevent metastasis. See related commentary by Zerhouni and Piskounova, p. 4124.

Chrono-exercise: Time-of-day-dependent physiological responses to exercise

Exercise is an effective strategy to prevent and improve obesity and related metabolic diseases. Exercise increases the metabolic demand in the body. Although many of the metabolic health benefits of exercise depend on skeletal muscle adaptations, exercise exerts many of its metabolic effects through the liver, adipose tissue, and pancreas. Therefore, exercise is the physiological state in which inter-organ signaling is most important. By contrast, circadian rhythms in mammals are associated with the regulation of several physiological and biological functions, including body temperature, sleep-wake cycle, physical activity, hormone secretion, and metabolism, which are controlled by clock genes. Glucose and lipid tolerance reportedly exhibit diurnal variations, being lower in the evening than in the morning. Therefore, the effects of exercise on substrate metabolism at different times of the day may differ. In this review, the importance of exercise timing considerations will be outlined, incorporating a chrono-exercise perspective.

Psoralea corylifolia L. seed extract attenuates dexamethasone-induced muscle atrophy in mice by inhibition of oxidative stress and inflammation

ETHNOPHARMACOLOGICAL RELEVANCE

The seeds of Psoralea corylifolia (PCS), also called "Boh-Gol-Zhee" in Korean, have been used in traditional medicine. PCS is effective for the treatment of vitiligo, cancer, inflammatory diseases, neurodegenerative diseases, kidney diseases, and musculoskeletal diseases.

AIM OF THE STUDY

In this study, we validated the beneficial effects of PCS extract on dexamethasone (DEX)-induced muscle atrophy in mice.

MATERIALS AND METHODS

DEX (20 mg/kg/day, 10 days) was intraperitoneally injected into C57BL/6 male mice to induce muscular atrophy. Oral administration of PCS extract (200 or 500 mg/kg/day) was started 2 days before DEX injection and continued for 12 days.

RESULTS

PCS extract inhibited DEX-induced decrease in body and muscle weight, grip strength, and cross-sectional area of the tibialis anterior. PCS extract significantly increased the mRNA and protein expression levels of myosin heavy chain 1, 2A, and 2X in DEX-administered mice. DEX administration significantly increased the levels of muscle atrophy factors atrogin-1, muscle RING-finger protein-1, and myostatin, which were inhibited by the PCS extract. Additionally, PCS extract increased the expression of muscle regeneration factors, such as myoblast determination protein 1, myogenin, and embryonic myosin heavy chain, and muscle synthesis markers, such as protein kinase B and mammalian target of rapamycin signaling molecules. PCS extract also significantly decreased the DEX-induced production of 4-hydroxynonenal, an oxidative stress marker. Furthermore, PCS extract recovered superoxide dismutase 2, glutathione peroxidase, and catalase activities, which were significantly reduced by DEX administration. Moreover, DEX-induced activation of nuclear factor kappa-light-chain-enhancer of activated B cells and expression of cytokines, such as tumor necrosis factor α and monocyte chemoattractant protein-1, significantly decreased after PCS extract administration.

CONCLUSIONS

Here, we demonstrated that PCS extract administration protected against DEX-induced muscle atrophy. This beneficial effect was mediated by suppressing the expression of muscle degradation factors and increasing the expression of muscle regeneration and synthesis factors. This effect was probably due to the inhibition of oxidative stress and inflammation. These results highlight the potential of PCS extract as a protective and therapeutic agent against muscle dysfunction and atrophy.

Causal associations of obesity related anthropometric indicators and body compositions with knee and hip arthritis: A large-scale genetic correlation study

Backgrounds

Epidemiological studies have repeatedly investigated the association between obesity related anthropometric indicators and body compositions and osteoarthritis (OA). However, the results have remained inconsistent. This work aimed to investigate the genetic correlation and causal associations of obesity related anthropometric indicators and body compositions with knee and hip OA.

Methods

Single-nucleotide polymorphisms associated with the exposures were searched from the recent genome-wide association studies (GWAS) to obtain full statistics. Summary-level results of knee and hip OA were from the UK Biobank and arcOGEN. First, linkage disequilibrium score regression (LD score regression) was applied to detect the genetic correlation (rg). We further performed a series of sensitivity analyses as validation of primary mendelian randomization (MR) results and the specific evidence of potential causal effects was defined.

Results

We found that genetic components in OA had significant correlation with obesity related traits, except waist-to-hip ratio. In the univariable MR analysis, with the exception of waist-to-hip ratio, obesity related anthropometric indicators were causally associated with increased risks of knee and hip OA. For obesity related body compositions, higher fat-free mass in arm, leg, and whole body increased the risk of knee OA but only fat-free mass in leg showed a significant association with hip OA. Meanwhile trunk fat mass and trunk fat percentage, were associated with knee but not with hip OA. Higher fat mass, and fat percentage in arm, leg, and whole body increased the risk of both knee and hip OA. After adjusting for BMI, the multivariable MR showed maintained results in knee OA. However, in hip OA, only fat mass and fat-free mass in arm, leg, trunk and whole body were significantly associated with the risk of hip OA.

Conclusion

The present study suggests genetic evidence for certain causal associations of obesity related anthropometric indicators and body compositions with knee and hip OA, which may provide important insights for the prevention and treatment on OA.

Obesity Management in the Primary Prevention of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most frequent primary hepatic malignancy and a leading cause of cancer-related death globally. HCC is associated with an indolent clinical presentation, resulting in frequent advanced stage diagnoses where surgical resection or transplant therapies are not an option and medical therapies are largely ineffective at improving survival. As such, there is a critical need to identify and enhance primary prevention strategies to mitigate HCC-related morbidity and mortality. Obesity is an independent risk factor for the onset and progression of HCC. Furthermore, obesity is a leading cause of nonalcoholic steatohepatitis (NASH), the fasting growing etiological factor of HCC. Herein, we review evolving clinical and mechanistic associations between obesity and hepatocarcinogenesis with an emphasis on the therapeutic efficacy of prevailing lifestyle/behavioral, medical, and surgical treatment strategies for weight reduction and NASH reversal.

Brief exposure to directionally-specific pulsed electromagnetic fields stimulates extracellular vesicle release and is antagonized by streptomycin: A potential regenerative medicine and food industry paradigm

Pulsing electromagnetic fields (PEMFs) have been shown to promote in vitro and in vivo myogeneses via mitohormetic survival adaptations of which secretome activation is a key component. A single 10-min exposure of donor myoblast cultures to 1.5 mT amplitude PEMFs produced a conditioned media (pCM) capable of enhancing the myogenesis of recipient cultures to a similar degree as direct magnetic exposure. Downwardly-directed magnetic fields produced greater secretome responses than upwardly-directed fields in adherent and fluid-suspended myoblasts. The suspension paradigm allowed for the rapid concentrating of secreted factors, particularly of extracellular vesicles. The brief conditioning of basal media from magnetically-stimulated myoblasts was capable of conferring myoblast survival to a greater degree than basal media supplemented with fetal bovine serum (5%). Downward-directed magnetic fields, applied directly to cells or in the form of pCM, upregulated the protein expression of TRPC channels, markers for cell cycle progression and myogenesis. Direct magnetic exposure produced mild oxidative stress, whereas pCM provision did not, providing a survival advantage on recipient cells. Streptomycin, a TRP channel antagonist, precluded the production of a myogenic pCM. We present a methodology employing a brief and non-invasive PEMF-exposure paradigm to effectively stimulate secretome production and release for commercial or clinical exploitation.

Local and systemic transcriptomic responses from acute exercise induced muscle damage of the human knee extensors

Skeletal muscle is adaptable to a direct stimulus of exercise-induced muscle damage (EIMD). Local muscle gene networks and systemic circulatory factors respond to EIMD within days, mediating anti-inflammation and cellular proliferation. Here we show in humans that local EIMD of one muscle group is associated with a systemic response of gene networks that regulate muscle structure and cellular development in non-local homologous muscle not directly altered by EIMD. In the non-dominant knee-extensors of seven males, EIMD was induced through voluntary contractions against an electric motor that lengthened muscles. Neuromuscular assessments, vastus lateralis muscle biopsies and blood draws occurred at two days prior, and one and two days post the EIMD intervention. From the muscle and blood plasma samples, RNA-seq measured transcriptome changes of differential expression using bioinformatic analyses.Relative to the time of the EIMD intervention, local muscle that was mechanically damaged had 475 genes differentially expressed, as compared to 33 genes in the non-local homologous muscle. Gene and network analysis showed that activity of the local muscle was related to structural maintenance, repair, and energetic processes, whereas gene and network activity of the non-local muscle (that was not directly modified by the EIMD) were related to muscle cell development, stress response, and structural maintenance. Altered expression of two novel miRNAs related to the EIMD response supported that systemic factors were active. Together, these results indicate that the expression of genes and gene networks that control muscle contractile structure can be modified in response to non-local EIMD in humans.

Mst1/2 is necessary for satellite cell differentiation to promote muscle regeneration

The diminished ability for muscle to regenerate is associated with aging, diabetes and cancers. Muscle regeneration depends on the activation and differentiation of satellite cells (SCs). Inactivation of Mst1/2 promotes cell proliferation by activating Yap, and that has been reported as a potential therapeutic target for improving many organ regeneration. However, the function of Mst1/2 in SCs fate decision and that effect on muscle regeneration remain unknown. By using inducible conditional knockout Mst1/2 in the SCs of mice and an inhibitor of Mst1/2, we found that inhibition of Mst1/2 in SCs significantly decrease Yap phosphorylation, thus causing Yap to accumulate in the nucleus and impairing SC differentiation; Mst1/2 were slightly elevated by irisin stimulation during SC differentiation; but inhibiting Mst1/2 in SCs significantly impaired irisin-induced muscle regeneration. These results indicate that Mst1/2 is necessary for SC differentiation and inhibiting Mst1/2 as a therapeutic target has potential risks for muscle regeneration.

Intensity Dependent Effects of Interval Resistance Training on Myokines and Cardiovascular Risk Factors in Males With Obesity

OBJECTIVE

To determine the effects of different intensities of interval resistance training (IRT) protocols on the levels of select myokines (decorin, follistatin, myostatin, activin A, transforming growth factor beta-1 [TGF-β1]), and cardiometabolic and anthropometric measures in males with obesity.

METHODS

Forty-four obese males (age: 27.5 ± 9.4 yr.; height: 165.4 ± 2.8 cm; weight: 97.9 ± 2.6 kg and BMI: 35.7 ± 4.3 kg/m²) were randomly assigned to one of four groups (n=11 per group): low-intensity interval resistance training (LIIRT), moderate-intensity interval resistance training (MIIRT), high-intensity interval resistance training (HIIRT) or control (C). The LIIRT group performed 10 exercises in 3 sets of 40% (20 repetitions), the MIIRT group performed 10 exercises in three sets of 60% (13 repetitions), and the HIIRT group performed 10 exercises in three sets of 80% (10 repetitions) of one maximum repetition (1RM), which were followed with active rest of 20% of 1RM and 15 repetitions. The resistance training groups exercised ~70 min per session, 3 days per week, for 12 weeks. Measurements were taken at baseline and after 12 weeks of exercise training.

RESULTS

Baseline levels of myokines, cardiovascular risk factors, anthropometry, body composition, and cardio-respiratory fitness were not different between the four groups (p>0.05). The group x time interactions for decorin, activin A, follistatin, myostatin, and TGF-β1, total cholesterol (TC), triglyceride (TG), high-density cholesterol (HDL), low-density cholesterol (LDL), anthropometry, body composition, and cardio-respiratory fitness were statistically significant (p<0.05). There were increases in post-test values for decorin, follistatin, HDL (p<0.05) and decreases in TC, TG, TGF-β1, LDL, and myostatin levels in the LIIRT, MIIRT, and HIIRT groups compared to pretest values (p<0.05). Changes in fat mass, VO_2peak, HDL, TG, glucose, activin A, decorin were not significant in LIIRT compared to the control group, while changes in activin A, follistatin, and TFG-β1 levels were greater in HIIRT and MIIRT groups compared to the LIIRT group (p<0.05).

CONCLUSION

The LIIRT, MIIRT, and HIIRT protocols all produced beneficial changes in decorin, activin A, follistatin, myostatin, and TGF-β1 levels, and cardiometabolic risk factors, with greater effects from the MIIRT and HIIRT protocols compared to LIIRT.

Physical Activity, Obesity and Weight Loss Maintenance

Regular physical activity has an impact on all human organ systems and mediates multiple beneficial effects on overall health. Physical activity alone is a poor strategy for weight loss; however, physical activity is of crucial importance for weight loss maintenance. The role of exercise in maintaining a stable body weight is not clear but might be related to better appetite regulation and food preference. In relation to exercise, muscle secretes myokines and other factors that can influence the metabolism in other organs, not least fat and brain tissues. Thereby, physical activity reduces the risk of obesity-associated diseases, such as type 2 diabetes and cardiovascular diseases, independently of weight loss and BMI. Therefore, physical activity should always be included in weight loss strategies and as a tool to maintain a healthy weight, despite its modest effect on energy expenditure and overall body weight.

Population Genetic Polymorphism of Skeletal Muscle Strength Related Genes in Five Ethnic Minorities in North China

Musculoskeletal performance is a complex trait influenced by environmental and genetic factors, and it has different manifestations in different populations. Heilongjiang province, located in northern China, is a multi-ethnic region with human cultures dating back to the Paleolithic Age. The Daur, Hezhen, Ewenki, Mongolian and Manchu ethnic groups in Heilongjiang province may have strong physical fitness to a certain extent. Based on the genetic characteristics of significant correlation between some important genes and skeletal muscle function, this study selected 23 SNPs of skeletal muscle strength-related genes and analyzed the distribution of these loci and genetic diversity in the five ethnic groups. Use Haploview (version 4.1) software to calculate the chi-square and the Hardy-Weinberg equilibrium to assess the difference between the two ethnic groups. Use R (version 4.0.2) software to perform principal component analysis of different ethnic groups. Use MEGA (version 7.0) software to construct the phylogenetic tree of different ethnic groups. Use POPGENE (version 1.32) software to calculate the heterozygosity and the F_ST values of 23 SNPs. Use Arlequin (version 3.5.2.2) software to analyze molecular variance (AMOVA) among 31 populations. The results showed that there was haplotype diversity of VDR, angiotensin-converting enzyme, ACTN3, EPO and IGF1 genes in the five ethnic groups, and there were genetic differences in the distribution of these genes in the five ethnic groups. Among them, the average gene heterozygosity (AVE_HET) of the 23 SNPs in the five populations was 0.398. The F_ST values of the 23 SNPs among the five ethnic groups varied from 0.0011 to 0.0137. According to the principal component analysis, the genetic distance of Daur, Mongolian and Ewenki is relatively close. According to the phylogenetic tree, the five ethnic groups are clustered together with the Asian population. These data will enrich existing genetic information of ethnic minorities.

Association of metabolic traits with occurrence of nonalcoholic fatty liver disease-related hepatocellular carcinoma: A systematic review and meta-analysis of longitudinal cohort studies

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) has become one of the leading etiologies of hepatocellular carcinoma (HCC), but risk factors for NAFLD-related HCC occurrence have not been defined. NAFLD is often complicated by metabolic abnormalities, and there is a bidirectional association of metabolic abnormalities with NAFLD progression. This study aimed to systematically evaluate the relationship between metabolic traits and HCC occurrence in patients with NAFLD.

METHOD

This study reviewed eight eligible studies that included 297,956 participants, to determine the relationship between metabolic traits and the occurrence of HCC in patients with NAFLD.

RESULTS

Presence of diabetes mellitus (DM) was associated with increased risk of HCC (HR: 2.65, 95%CI: 2.02 ~ 3.49, P_{heterogeneity} = 0.589, I² = 0.0%). Stratified analysis revealed that this risk was higher in NAFLD patients with advanced fibrosis/cirrhosis (HR: 4.55, 95%CI: 2.34 ~ 8.87, P_{heterogeneity} = 0.870, I² = 0.0%). Nonetheless even in patients without cirrhosis, DM remained a high risk factor for HCC incidence (HR: 1.80, 95%CI: 1.05 ~ 3.06, P_{heterogeneity} = 0.291, I² = 10.4%). Overweight/obesity had a slight correlation with increased risk of HCC occurrence in NAFLD patients (HR: 1.31, 95%CI: 1.00 ~ 1.71, P_{heterogeneity} = 0.888, I² = 0.0%), while presence of hypertension and dyslipidemia had no correlation.

CONCLUSION

DM and overweight/obesity are high risk factors for NAFLD-related HCC. In particular, DM increases 4-fold the risk of HCC incidence in NAFLD patients with advanced fibrosis/cirrhosis. There is a need to strengthen surveillance for HCC in NAFLD patients with DM, especially in those with advanced fibrosis/cirrhosis.

Systemically Administered Homing Peptide Targets Dystrophic Lesions and Delivers Transforming Growth Factor-β (TGFβ) Inhibitor to Attenuate Murine Muscular Dystrophy Pathology

Muscular dystrophy is a progressively worsening and lethal disease, where accumulation of functionality-impairing fibrosis plays a key pathogenic role. Transforming growth factor-β1 (TGFβ1) is a central signaling molecule in the development of fibrosis in muscular dystrophic humans and mice. Inhibition of TGFβ1 has proven beneficial in mouse models of muscular dystrophy, but the global strategies of TGFβ1 inhibition produce significant detrimental side effects. Here, we investigated whether murine muscular dystrophy lesion-specific inhibition of TGFβ1 signaling by the targeted delivery of therapeutic decorin (a natural TGFβ inhibitor) by a vascular homing peptide CAR (CARSKNKDC) would reduce skeletal muscle fibrosis and pathology and increase functional characteristics of skeletal muscle. We demonstrate that CAR peptide homes to dystrophic lesions with specificity in two muscular dystrophy models. Recombinant fusion protein consisting of CAR peptide and decorin homes selectively to sites of skeletal muscle damage in mdxDBA2/J and gamma-sarcoglycan deficient DBA2/J mice. This targeted delivery reduced TGFβ1 signaling as demonstrated by reduced nuclear pSMAD staining. Three weeks of targeted decorin treatment decreased both membrane permeability and fibrosis and improved skeletal muscle function in comparison to control treatments in the mdxD2 mice. These results show that selective delivery of decorin to the sites of skeletal muscle damage attenuates the progression of murine muscular dystrophy.

Prognostic Impact of Sarcopenia in Patients With Biliary Tract Cancer Undergoing Chemotherapy

AIM

Sarcopenia affects the treatment of various cancer types but its impact on chemotherapy efficacy and prognosis in biliary tract cancer remains unclear. Thus, we evaluated whether sarcopenia independently affects the outcome of chemotherapy for biliary tract cancer.

PATIENTS AND METHODS

Data of 50 patients who underwent chemotherapy for biliary tract cancer at two affiliated centres were retrospectively analysed. The association of clinical factors, including sarcopenia, with overall survival and time to treatment failure was analysed.

RESULTS

Sarcopenia was an independent factor negatively influencing overall survival and time to treatment failure in univariate and multivariate analyses (median overall survival, sarcopenic vs. non-sarcopenic patients: 10.6 vs. 16.6 months; hazard ratio=2.19, p=0.018; time to treatment failure: 5.3 vs. 13.1 months, hazard ratio=2.50, p=0.019).

CONCLUSION

Sarcopenia may affect the efficacy of chemotherapy and prognosis in biliary tract cancer. Thus, improving sarcopenia may improve the prognosis of patients with biliary tract cancer undergoing chemotherapy.

Muscle-Derived Cytokines Reduce Growth, Viability and Migratory Activity of Pancreatic Cancer Cells

Simple Summary

Pancreatic cancer (PC) is a highly fatal malignancy. A major reason for the poor prognosis of patients with PC is the insensitivity to most oncological treatment approaches. It is known that regular exercise reduces the cancer risk. We have already shown that serum from advanced prostate and colon cancer patients after exercise reduces growth and viability of cancer cells. The aim of this study was to identify exercise-induced cytokines in serum from patients with advanced-stage PC that regulate cancer cell proliferation and apoptosis. Our data suggest that a mild resistance exercise training in advanced PC patients induces the release of CXCL1, IL10 and CCL4 from contracting skeletal muscle. We demonstrate that these myokines inhibit growth and migration of PC cells, and induce PC cell death. With this report we provide new knowledge on the cancer-protective function of exercise in PC. Our data strongly support sport therapies for cancer patients.

Abstract

The evidence that regular physical exercise reduces the risk of developing cancer is well described. However, the interaction between physical exercise and cancer is not fully clarified yet. Several myokines released by skeletal muscle appear to have a direct anti-tumour function. There are few data on myokine secretion after exercise in patients with advanced tumours. Pancreatic cancer (PC) is a very aggressive and usually fatal cancer. To investigate the effects of exercise in PC, the blood of advanced-stage PC patients was analysed after 12 weeks of resistance training using whole-body electromyostimulation. After the 12-week training period, the patient serum inhibited the proliferation and the motility of PC cells and enhanced PC cell apoptosis. The impact of exercise training was also investigated in an exercise-mimicking in vitro model using electric pulse stimulation of human myotubes and revealed similar anti-tumour effects on PC cells, clearly indicating direct cancer-protective properties of activated skeletal muscle. Protein and gene expression analyses in plasma from exercise-trained patients and in myotube cultures after in vitro exercise showed that interleukin 10 (IL10), C-X-C motif ligand 1 (CXCL1) and C-C motif chemokine ligand 4 (CCL4) are myokines released from activated skeletal muscle. In accordance with the effects of serum from exercise-trained patients, the supplementation with recombinant IL10, CXCL1 and CCL4 impaired growth and migration of PC cells. Treatment of PC cells with these myokines upregulated caspase 3/7 expression and the cleavage of poly(ADP-ribose) polymerase, leading to enhanced PC cell death. The identification of myokines with anti-tumour properties in advanced-stage PC patients after exercise opens a new perspective in supportive therapy with sports and exercise for cancer patients.

The Prognostic Value of Low Muscle Mass in Pancreatic Cancer Patients: A Systematic Review and Meta-Analysis

Low muscle mass is associated with reduced survival in patients with different cancer types. The interest in preoperative sarcopenia and pancreatic cancer has risen in the last decade as muscle mass loss seems to be associated with poorer survival, higher postoperative morbidity, and mortality. The aim of the present study was to review the literature to compare the impact of low muscle mass on the outcomes of patients undergoing surgery for pancreatic adenocarcinoma. An extensive literature review was conducted according to the 2009 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and 10 articles were analyzed in detail and included in the meta-analysis. Data were retrieved on 2811 patients undergoing surgery for pancreatic cancer. Meta-analysis identified that patients with low muscle mass demonstrated a significantly reduced OS when compared to patients without alterations of the muscle mass (ROM 0.86; 95% CI: 0.81-0.91, p < 0.001), resulting in a 14% loss for the former. Meta-analysis failed to identify an increase in the postoperative complications and length of stay of patients with low muscle mass. Our analysis confirms the role of low muscle mass in influencing oncologic outcomes in pancreatic cancer. Its role on surgical outcomes remains to be established.

Dose-response effects of physical activity on all-cause mortality and major cardiorenal outcomes in chronic kidney disease

AIMS

Physical activity has a protective effect against mortality and cardiovascular events in chronic kidney disease (CKD) patients. Nonetheless, how different levels of physical activity affect the health benefits in CKD remains unclear. This study aimed to investigate the dose-response effects of physical activity on mortality and major cardiorenal events in CKD.

METHODS AND RESULTS

We evaluated a longitudinal cohort of 4508 Taiwanese CKD patients between 2004 and 2017. Physical activity was assessed by the NHANES questionnaire and quantified in metabolic equivalent-hours per week (MET-hour/week). Patients were categorized into highly active (≥7.5 MET-h/week), low-active (0.1 to <7.5 MET-h/week), or inactive (0 MET-h/week) groups. Cox regression and restricted cubic spline models were utilized to explore the association between physical activity and the risks of study outcomes, including all-cause mortality, end-stage renal disease (ESRD), and major adverse cardiovascular events (MACE, a composite of cardiovascular death, myocardial infarction, ischaemic stroke, and hospitalized heart failure). During a median follow-up of 686 days, 739 death, 1059 ESRD, and 521 MACE events occurred. Highly active group had the lowest chance of all study outcomes, followed by low-active and inactive groups (P < 0.001). Multivariable Cox regression showed that only highly active group was independently associated with lower risks for all-cause mortality [hazard ratio (HR) 0.62; 95% confidence interval (CI) 0.53-0.74], ESRD (HR 0.83, 95% CI 0.72-0.96), and MACE (HR 0.63, 95% CI 0.51-0.76) compared to the inactive group. The risks of MACE did not further decrease once physical activity surpassed 15 MET-h/week, indicating a U-shaped association. The results were consistent in the subgroup and sensitivity analyses.

CONCLUSION

Physical activity of 7.5 to <15 MET-h/week is associated with lower risks of adverse cardiorenal outcomes and should be integrated into the care of CKD.

Body Protein Sparing in Hibernators: A Source for Biomedical Innovation

Proteins are not only the major structural components of living cells but also ensure essential physiological functions within the organism. Any change in protein abundance and/or structure is at risk for the proper body functioning and/or survival of organisms. Death following starvation is attributed to a loss of about half of total body proteins, and body protein loss induced by muscle disuse is responsible for major metabolic disorders in immobilized patients, and sedentary or elderly people. Basic knowledge of the molecular and cellular mechanisms that control proteostasis is continuously growing. Yet, finding and developing efficient treatments to limit body/muscle protein loss in humans remain a medical challenge, physical exercise and nutritional programs managing to only partially compensate for it. This is notably a major challenge for the treatment of obesity, where therapies should promote fat loss while preserving body proteins. In this context, hibernating species preserve their lean body mass, including muscles, despite total physical inactivity and low energy consumption during torpor, a state of drastic reduction in metabolic rate associated with a more or less pronounced hypothermia. The present review introduces metabolic, physiological, and behavioral adaptations, e.g., energetics, body temperature, and nutrition, of the torpor or hibernation phenotype from small to large mammals. Hibernating strategies could be linked to allometry aspects, the need for periodic rewarming from torpor, and/or the ability of animals to fast for more or less time, thus determining the capacity of individuals to save proteins. Both fat- and food-storing hibernators rely mostly on their body fat reserves during the torpid state, while minimizing body protein utilization. A number of them may also replenish lost proteins during arousals by consuming food. The review takes stock of the physiological, molecular, and cellular mechanisms that promote body protein and muscle sparing during the inactive state of hibernation. Finally, the review outlines how the detailed understanding of these mechanisms at play in various hibernators is expected to provide innovative solutions to fight human muscle atrophy, to better help the management of obese patients, or to improve the ex vivo preservation of organs.

FNDC5 polymorphism influences the association between sarcopenia and liver fibrosis in adults with biopsy-proven non-alcoholic fatty liver disease

The FNDC5 gene encodes the fibronectin type III domain-containing protein 5 that is a membrane protein mainly expressed in skeletal muscle, and the FNDC5 rs3480 polymorphism may be associated with liver disease severity in non-alcoholic fatty liver disease (NAFLD). We investigated the influence of the FNDC5 rs3480 polymorphism on the relationship between sarcopenia and the histological severity of NAFLD. A total of 370 adult individuals with biopsy-proven NAFLD were studied. The association between the key exposure sarcopenia and the outcome liver histological severity was investigated by binary logistic regression. Stratified analyses were undertaken to examine the impact of FNDC5 rs3480 polymorphism on the association between sarcopenia and the severity of NAFLD histology. Patients with sarcopenia had more severe histological grades of steatosis and a higher prevalence of significant fibrosis and definite non-alcoholic steatohepatitis than those without sarcopenia. There was a significant association between sarcopenia and significant fibrosis (adjusted OR 2·79, 95 % CI 1·31, 5·95, P = 0·008), independent of established risk factors and potential confounders. Among patients with sarcopenia, significant fibrosis occurred more frequently in the rs3480 AA genotype carriers than in those carrying the FNDC5 rs3480 G genotype (43·8 v. 17·2 %, P = 0·031). In the association between sarcopenia and liver fibrosis, there was a significant interaction between the FNDC5 genotype and sarcopenia status (P value for interaction = 0·006). Sarcopenia is independently associated with significant liver fibrosis, and the FNDC5 rs3480 G variant influences the association between sarcopenia and liver fibrosis in patients with biopsy-proven NAFLD.

Delivery of muscle-derived exosomal miRNAs induced by HIIT improves insulin sensitivity through down-regulation of hepatic FoxO1 in mice

Implementation of regular physical activity helps in the maintenance of a healthy metabolic profile both in humans and mice through molecular mechanisms not yet completely defined. Here, we show that high-intensity interval training (HIIT) modifies the microRNA (miRNA) profile of circulating exosomes in mice, including significant increases in miR-133a and miR-133b Importantly, treatment of sedentary mice with exosomes isolated from the plasma of trained mice improves glucose tolerance, insulin sensitivity, and decreases plasma levels of triglycerides. Moreover, exosomes isolated from the muscle of trained mice display similar changes in miRNA content, and their administration to sedentary mice reproduces the improvement of glucose tolerance. Exosomal miRNAs up-regulated by HIIT target insulin-regulated transcription factor forkhead box O1 (FoxO1) and, accordingly, expression of FoxO1 is decreased in the liver of trained and exosome-treated mice. Treatment with exosomes transfected with a miR-133b mimic or with a specific siRNA targeting FoxO1 recapitulates the metabolic effects observed in trained mice. Overall, our data suggest that circulating exosomes released by the muscle carry a specific miRNA signature that is modified by exercise and induce expression changes in the liver that impact whole-body metabolic profile.

Multi-Cellular Functions of MG53 in Muscle Calcium Signaling and Regeneration

Since its identification in 2009, multiple studies have indicated the importance of MG53 in muscle physiology. The protein is produced in striated muscles but has physiologic implications reaching beyond the confines of striated muscles. Roles in muscle regeneration, calcium homeostasis, excitation-contraction coupling, myogenesis, and the mitochondria highlight the protein’s wide-reaching impact. Numerous therapeutic applications could potentially emerge from these physiologic roles. This review summarizes the current literature regarding the role of MG53 in the skeletal muscle. Therapeutic applications are discussed.

Impact of diets rich in olive oil, palm oil or lard on myokine expression in rats

It has recently emerged that myokines may be an important skeletal muscle adaptive response to obesogenic diets in sedentary subjects (who do not exercise). This study aimed to assess the influence of various high fat (HF) diets rich in either crude palm oil (cPO), refined palm oil (rPO), olive oil (OO) or lard on the modulation of myokine gene expression in the gastrocnemius. Five groups of 8 rats were each fed HF or control diet for 12 weeks. Systemic parameters concerning glucose, insulin, inflammation, cholesterol, triglycerides (TG) and transaminases were assessed by routine methods or ELISA. Akt and ACC phosphorylation were analyzed by WB in the soleus. Mitochondrial density, inflammation, and the gene expression of 17 myokines and the apelin receptor (Apj) were assessed by qPCR in the gastrocnemius. We found that HF diet-fed rats were insulin resistant and Akt phosphorylation decreased in the soleus muscle, but without any change in Glut4 gene expression. Systemic (IL-6) and muscle inflammation (NFκB and IκB) were not affected by the HF diets as well as TBARS, and ASAT level was enhanced with OO diet. Soleus pACC phosphorylation and gastrocnemius mitochondrial density were not significantly altered. The gene expression of some myokines was respectively increased (myostatin and Il-15) and decreased (Fndc5 and apelin) with the HF diets, whatever the type of fat used. The gene expression of two myokines with anti-inflammatory properties, Il-10 and myonectin, was dependent on the type of fat used and was most increased respectively with cPO or both rPO and OO diets. In conclusion, high-fat diets can differentially modulate the expression of some myokines, either in a dependent manner or independently of their composition.

Irisin and Autophagy: First Update

Aging and sedentary life style are considered independent risk factors for many disorders. Under these conditions, accumulation of dysfunctional and damaged cellular proteins and organelles occurs, resulting in a cellular degeneration and cell death. Autophagy is a conserved recycling pathway responsible for the degradation, then turnover of cellular proteins and organelles. This process is a part of the molecular underpinnings by which exercise promotes healthy aging and mitigate age-related pathologies. Irisin is a myokine released during physical activity and acts as a link between muscles and other tissues and organs. Its main beneficial function is the change of subcutaneous and visceral adipose tissue into brown adipose tissue, with a consequential increase in thermogenesis. Irisin modulates metabolic processes, acting on glucose homeostasis, reduces systemic inflammation, maintains the balance between resorption and bone formation, and regulates the functioning of the nervous system. Recently, some of its pleiotropic and favorable properties have been attributed to autophagy induction, posing irisin as an important regulator of autophagy by exercise. This review article proposes to bring together for the first time the "state of the art" knowledge regarding the effects of irisin and autophagy. Furthermore, treatments on relation between exercise/myokines and autophagy have been also achieved.

Helicobacter pylori Related Diseases and Osteoporotic Fractures (Narrative Review)

Osteoporosis (OP) and osteoporotic fractures (OFs) are common multifactorial and heterogenic disorders of increasing incidence. Helicobacter pylori (H.p.) colonizes the stomach approximately in half of the world's population, causes gastroduodenal diseases and is prevalent in numerous extra-digestive diseases known to be associated with OP/OF. The studies regarding relationship between H.p. infection (HPI) and OP/OFs are inconsistent. The current review summarizes the relevant literature on the potential role of HPI in OP, falls and OFs and highlights the reasons for controversies in the publications. In the first section, after a brief overview of HPI biological features, we analyze the studies evaluating the association of HPI and bone status. The second part includes data on the prevalence of OP/OFs in HPI-induced gastroduodenal diseases (peptic ulcer, chronic/atrophic gastritis and cancer) and the effects of acid-suppressive drugs. In the next section, we discuss the possible contribution of HPI-associated extra-digestive diseases and medications to OP/OF, focusing on conditions affecting both bone homeostasis and predisposing to falls. In the last section, we describe clinical implications of accumulated data on HPI as a co-factor of OP/OF and present a feasible five-step algorithm for OP/OF risk assessment and management in regard to HPI, emphasizing the importance of an integrative (but differentiated) holistic approach. Increased awareness about the consequences of HPI linked to OP/OF can aid early detection and management. Further research on the HPI-OP/OF relationship is needed to close current knowledge gaps and improve clinical management of both OP/OF and HPI-related disorders.

Lpl-C310R mutation is associated with impaired glucose tolerance and endoplasmic reticulum stress in skeletal muscle

Primary Hypertriglyceridemia refers to a loss-of-function genetic defect which prevents the triglyceride (TG) in chylomicrons (CM) from lipolysis, leading to the accumulation of TG. The mutation of lipoprotein lipase (LPL) gene has been recognized as the main cause of primary hypertriglyceridemia. Recently, a new LPL gene mutation p.C310R(c. T928C) was identified in a family with hypertriglyceridemia. The proband was manifested by severe hypertriglyceridemia and diabetes. Skeletal muscle is the major LPL-synthesizing tissue and insulin response target tissue. However, little is known about the effects of LPL gene mutation on skeletal muscle. This study is intended to observe the effects of LPL-C310R mutation on glycolipid metabolism and skeletal muscle. We found that a significantly decreased LPL plasma concentration, activity and the expression levels in skeletal muscle were observed in Lpl^C310R/+ mice comparing to wild type mice. Those mutant mice also exhibited increased fasting plasma TG, free fat acids (FFA) and insulin, as well as FFA in muscle, and decreased glucose tolerance. Enhanced expression of BIP and elevated phosphorylation of IRE1α were observed in skeletal muscle, suggesting increased endoplasmic reticulum stress (ERS). Consistent with this, increased phosphorylation of JNK was also observed. Meanwhile, remarkably enhanced phosphorylation of IRS-1 (Ser307) and decreased phosphorylation of AKT were observed in skeletal muscle of mutant mice, suggesting impaired insulin signaling. Significant lipid deposition and morphological changes in endoplasmic reticulum and mitochondria were observed in the skeletal muscle of mutant mice but not in wild type control. Results demonstrate Lpl C310R mutation caused impaired glucose tolerance, ER stress and impaired insulin signaling in skeletal muscle.

Muscle-Organ Crosstalk: The Emerging Roles of Myokines

Physical activity decreases the risk of a network of diseases, and exercise may be prescribed as medicine for lifestyle-related disorders such as type 2 diabetes, dementia, cardiovascular diseases, and cancer. During the past couple of decades, it has been apparent that skeletal muscle works as an endocrine organ, which can produce and secrete hundreds of myokines that exert their effects in either autocrine, paracrine, or endocrine manners. Recent advances show that skeletal muscle produces myokines in response to exercise, which allow for crosstalk between the muscle and other organs, including brain, adipose tissue, bone, liver, gut, pancreas, vascular bed, and skin, as well as communication within the muscle itself. Although only few myokines have been allocated to a specific function in humans, it has been identified that the biological roles of myokines include effects on, for example, cognition, lipid and glucose metabolism, browning of white fat, bone formation, endothelial cell function, hypertrophy, skin structure, and tumor growth. This suggests that myokines may be useful biomarkers for monitoring exercise prescription for people with, for example, cancer, diabetes, or neurodegenerative diseases.

Exercise and metabolic health: beyond skeletal muscle

Regular exercise is a formidable regulator of insulin sensitivity and overall systemic metabolism through both acute events driven by each exercise bout and through chronic adaptations. As a result, regular exercise significantly reduces the risks for chronic metabolic disease states, including type 2 diabetes and non-alcoholic fatty liver disease. Many of the metabolic health benefits of exercise depend on skeletal muscle adaptations; however, there is plenty of evidence that exercise exerts many of its metabolic benefit through the liver, adipose tissue, vasculature and pancreas. This review will highlight how exercise reduces metabolic disease risk by activating metabolic changes in non-skeletal-muscle tissues. We provide an overview of exercise-induced adaptations within each tissue and discuss emerging work on the exercise-induced integration of inter-tissue communication by a variety of signalling molecules, hormones and cytokines collectively named 'exerkines'. Overall, the evidence clearly indicates that exercise is a robust modulator of metabolism and a powerful protective agent against metabolic disease, and this is likely to be because it robustly improves metabolic function in multiple organs. Graphical abstract.

DNA Methylation Reorganization of Skeletal Muscle-Specific Genes in Response to Gestational Obesity

The goals were to investigate in umbilical cord tissue if gestational obesity: (1) was associated with changes in DNA methylation of skeletal muscle-specific genes; (2) could modulate the co-methylation interactions among these genes. Additionally, we assessed the associations between DNA methylation levels and infant's variables at birth and at age 6. DNA methylation was measured in sixteen pregnant women [8-gestational obesity group; 8-control group] in umbilical cord using the Infinium Methylation EPIC Bead Chip microarray. Differentially methylated CpGs were identified with Beta Regression Models [false discovery rate (FDR) < 0.05 and an Odds Ratio > 1.5 or < 0.67]. DNA methylation interactions between CpGs of skeletal muscle-specific genes were studied using data from Pearson correlation matrices. In order to quantify the interactions within each network, the number of links was computed. This identification analysis reported 38 differential methylated CpGs within skeletal muscle-specific genes (comprising 4 categories: contractibility, structure, myokines, and myogenesis). Compared to control group, gestational obesity (1) promotes hypermethylation in highly methylated genes and hypomethylation in low methylated genes; (2) CpGs in regions close to transcription sites and with high CpG density are hypomethylated while regions distant to transcriptions sites and with low CpG density are hypermethylated; (3) diminishes the number of total interactions in the co-methylation network. Interestingly, the associations between infant's fasting glucose at age 6 and MYL6, MYH11, TNNT3, TPM2, CXCL2, and NCAM1 were still relevant after correcting for multiple testing. In conclusion, our study showed a complex interaction between gestational obesity and the epigenetic status of muscle-specific genes in umbilical cord tissue. Additionally, gestational obesity may alter the functional co-methylation connectivity of CpG within skeletal muscle-specific genes interactions, our results revealing an extensive reorganization of methylation in response to maternal overweight. Finally, changes in methylation levels of skeletal muscle specific genes may have persistent effects on the offspring of mothers with gestational obesity.

Physical activity and advanced cancer: evidence of exercise-sensitive genes regulating prostate cancer cell proliferation and apoptosis

KEY POINTS

Physical activity is known to protect against cancer. The resistance exercise method whole-body electromyostimulation (WB-EMS) has a significant anti-cancer effect. WB-EMS-conditioned serum from advanced prostate cancer patients decreased human prostate carcinoma cell growth and viability in vitro. Multiplex analysis revealed that genes associated with human prostate cancer cell proliferation and apoptosis are sensitive for exercise. Feasible exercise should be part of multimodal anti-cancer therapies, also for physically weakened patients.

ABSTRACT

Regular physical activity is known to protect against cancer development. In cancer survivors, exercise reduces the risk of cancer recurrence and mortality. However, the link between exercise and decreased cancer risk and improved survival is still not well understood. Serum from exercising healthy individuals inhibits proliferation and activates apoptosis in various cancer cells, suggesting that mechanisms regulating cancer cell growth are affected by exercise. For the first time, we analysed serum from advanced-stage cancer patients with prostate (exercise group n = 8; control group n = 10) or colorectal (exercise n = 6; control n = 6) cancer, after a 12-week whole-body electromyostimulation training (20 min/session, 2×/week; frequency 85 Hz; pulse width 350 µs; 6 s stimulation, 4 s rest), a tolerable, yet effective, resistance exercise for physically weakened patients. We report that serum from these advanced cancer patients inhibits proliferation and enhances apoptosis of human prostate and colon cancer cells in vitro using cell growth and death assays (5-bromo-2'-deoxyuridine incorporation, cell counting, DNA fragmentation). Exercise-mimicking electric pulse stimulation of human primary myotubes showed that electric pulse stimulation-conditioned myotube medium also impairs human cancer cell viability. Gene expression analysis using a multiplex array of cancer-associated genes and subsequent quantitative RT-PCR revealed the presence of exercise-sensitive genes in human prostate cancer cells that potentially participate in the exercise-mediated regulation of malignant cell growth and apoptosis. Our data document the strong efficiency of the anti-oncogenic effects of physical activity and will further support the application of regular therapeutic exercise during cancer disease.

Signaling Pathways That Control Muscle Mass

The loss of skeletal muscle mass under a wide range of acute and chronic maladies is associated with poor prognosis, reduced quality of life, and increased mortality. Decades of research indicate the importance of skeletal muscle for whole body metabolism, glucose homeostasis, as well as overall health and wellbeing. This tissue’s remarkable ability to rapidly and effectively adapt to changing environmental cues is a double-edged sword. Physiological adaptations that are beneficial throughout life become maladaptive during atrophic conditions. The atrophic program can be activated by mechanical, oxidative, and energetic distress, and is influenced by the availability of nutrients, growth factors, and cytokines. Largely governed by a transcription-dependent mechanism, this program impinges on multiple protein networks including various organelles as well as biosynthetic and quality control systems. Although modulating muscle function to prevent and treat disease is an enticing concept that has intrigued research teams for decades, a lack of thorough understanding of the molecular mechanisms and signaling pathways that control muscle mass, in addition to poor transferability of findings from rodents to humans, has obstructed efforts to develop effective treatments. Here, we review the progress made in unraveling the molecular mechanisms responsible for the regulation of muscle mass, as this continues to be an intensive area of research.

Diurnal Regulation of Peripheral Glucose Metabolism: Potential Effects of Exercise Timing

Diurnal oscillations in energy metabolism are linked to the activity of biological clocks and contribute to whole-body glucose homeostasis. Postprandially, skeletal muscle takes up approximately 80% of circulatory glucose and hence is a key organ in maintenance of glucose homeostasis. Dysregulation of molecular clock components in skeletal muscle disrupts whole-body glucose homeostasis. Next to light-dark cycles, nonphotic cues such as nutrient intake and physical activity are also potent cues to (re)set (dys)regulated clocks. Physical exercise is one of the most potent ways to improve myocellular insulin sensitivity. Given the role of the biological clock in glucose homeostasis and the power of exercise to improve insulin sensitivity, one can hypothesize that there might be an optimal time for exercise to maximally improve insulin sensitivity and glucose homeostasis. In this review, we aim to summarize the available information related to the interaction of diurnal rhythm, glucose homeostasis, and physical exercise as a nonphotic cue to correct dysregulation of human glucose metabolism.

Role of interleukin-15 in cardiovascular diseases

Interleukin (IL)‐15 is a recently identified cytokine, which belongs to the interleukin‐2(IL‐2) family, and plays an important role in innate and adaptive immunoreaction. Given the fact that the structure of IL‐15 is partially similar to IL‐2, they share some common biological effects, including immunoregulation. IL‐2 was proven to protect cardiac function in mouse myocardial infarction models. Cardiovascular diseases (CVDs) dominate the cause of mortality worldwide. Besides atherosclerosis, inflammation is also widely involved in the pathogenesis of many CVDs including hypertension, heart failure (HF) and aneurysm. IL‐15, as a pro‐inflammatory cytokine, is up‐regulated in some cardiovascular diseases, such as myocardial infarction and atherosclerosis. The current understanding of IL‐15, including its signal pathway and cellular function, was described. Furthermore, IL‐15 has a protective effect in myocardial infarction and myocarditis by decreasing cardiomyocyte death and improving heart function. The inhibited effect of IL‐15 in ductus arteriosus (DA) should be focused on. IL‐15 promoted atherogenesis. IL‐15 may be a good target in treatment of cardiovascular diabetology. Finally, future research direction of IL‐15 deserves attention. Since IL‐15 plays several roles in CVDs, understanding the role of the IL‐15/IL‐15R system may provide a scientific basis for the development of new approaches that use IL‐15 for the treatment of CVDs.

The kynurenine connection: how exercise shifts muscle tryptophan metabolism and affects energy homeostasis, the immune system, and the brain

Tryptophan catabolism through the kynurenine pathway generates a variety of bioactive metabolites. Physical exercise can modulate kynurenine pathway metabolism in skeletal muscle and thus change the concentrations of select compounds in peripheral tissues and in the central nervous system. Here we review recent advances in our understanding of how exercise alters tryptophan-kynurenine metabolism in muscle and its subsequent local and distal effects. We propose that the effects of kynurenine pathway metabolites on skeletal muscle, adipose tissue, immune system, and the brain suggest that some of these compounds could qualify as exercise-induced myokines. Indeed, some of the more recently discovered biological activities for kynurenines include many of the best-known benefits of exercise: improved energy homeostasis, promotion of an anti-inflammatory environment, and neuroprotection. Finally, by considering the tissue expression of the different membrane and cytosolic receptors for kynurenines, we discuss known and potential biological activities for these tryptophan metabolites.