Physical exercise shapes the mouse brain epigenome

Exercise protects impairments in memory recognition in the iron-deficient male rat model of Restless Legs Syndrome

Restless Legs Syndrome (RLS) is a neurological disorder characterized by an irresistible urge to move the legs and is associated with decreased quality of life and sleep, and may result in cognitive changes. Physical exercise generates cognitive improvements and improves RLS symptoms. Our objective is to analyze recognition memory in the iron-deficient rodent model of RLS, and the effect of exercise. The animals (male Wistar rats) were distributed at 21 days of age into a control group (CTRL) (standard diet) or an ID group (iron-deficient diet). After performance classification (at 77 days of age), the animals were redistributed into CTRL (no exercise), CTRL EX (exercise), ID (no exercise) and ID EX (exercise), totaling 9 animals per group. The exercise groups performed treadmill exercise for four weeks. In the 14th week of the diet, the sleep recording of CTRL and ID animals was carried out to validate the RLS model. The Novel Object Recognition Memory test (NOR) was performed before the start of exercise (8th week of diet) and after the end (14th week) in all groups. The ID group demonstrated worsening sleep parameters and increased paw movements compared to the control group. The ID group demonstrated impairment of recognition memory after 14 weeks of diet compared to the CTRL group, and, the CTRL improved recognition memory in the 14th week compared to the 8th week. No differences were found for the exercise groups. Our findings indicate that the RLS animal model exhibited cognitive alterations associated with recognition memory, and long-term aerobic exercise intervention demonstrated a protective influence against these effects.

Targeting neuronal epigenomes for brain rejuvenation

Aging is associated with a progressive decline of brain function, and the underlying causes and possible interventions to prevent this cognitive decline have been the focus of intense investigation. The maintenance of neuronal function over the lifespan requires proper epigenetic regulation, and accumulating evidence suggests that the deterioration of the neuronal epigenetic landscape contributes to brain dysfunction during aging. Epigenetic aging of neurons may, however, be malleable. Recent reports have shown age-related epigenetic changes in neurons to be reversible and targetable by rejuvenation strategies that can restore brain function during aging. This review discusses the current evidence that identifies neuronal epigenetic aging as a driver of cognitive decline and a promising target of brain rejuvenation strategies, and it highlights potential approaches for the specific manipulation of the aging neuronal epigenome to restore a youthful epigenetic state in the brain.

A Single-Cell Transcriptomic Analysis of the Mouse Hippocampus After Voluntary Exercise

Exercise has been recognized as a beneficial factor for cognitive health, particularly in relation to the hippocampus, a vital brain region responsible for learning and memory. Previous research has demonstrated that exercise-mediated improvement of learning and memory in humans and rodents correlates with increased adult neurogenesis and processes related to enhanced synaptic plasticity. Nevertheless, the underlying molecular mechanisms are not fully understood. With the aim to further elucidate these mechanisms, we provide a comprehensive dataset of the mouse hippocampal transcriptome at the single-cell level after 4 weeks of voluntary wheel-running. Our analysis provides a number of interesting observations. For example, the results suggest that exercise affects adult neurogenesis by accelerating the maturation of a subpopulation of Prdm16-expressing neurons. Moreover, we uncover the existence of an intricate crosstalk among multiple vital signaling pathways such as NF-κB, Wnt/β-catenin, Notch, and retinoic acid (RA) pathways altered upon exercise in a specific cluster of excitatory neurons within the Cornu Ammonis (CA) region of the hippocampus. In conclusion, our study provides an important resource dataset and sheds further light on the molecular changes induced by exercise in the hippocampus. These findings have implications for developing targeted interventions aimed at optimizing cognitive health and preventing age-related cognitive decline.

Integrating analysis of mRNA expression profiles indicates Sgk1 as a key mediator in muscle-brain crosstalk during resistance exercise

Abundant evidence has shown the protective effect of aerobic exercise on central neuronal system, however, research about resistance exercise remains limited. To evaluate the effect and potential molecular mechanisms of resistance exercise in improving cognition and mental health, three-month-old male C57BL/6J mice underwent resistance training for five weeks. Body parameters, cognitive performance and synaptic plasticity were then assessed. In both groups, total RNA from the frontal cortex, hippocampus and gastrocnemius was isolated and sequenced, GO term and KEGG analysis were performed to identify molecular mechanisms. The results from RNA sequencing were then verified by RT-PCR. Our data found that mice in training group showed reduced anxiety-like behavior and better spatial memory. Accordingly, resistance exercise specifically increased the number of thin spines without affecting the number of other kind of spines. mRNA sequence analysis showed that resistance exercise induced differential expression of hundreds of genes in the above three tissues. KEGG analysis indicated the FoxO signaling pathway the most significant changed pathway throughout the brain and muscle. GO terms analysis showed that Sgk1 was enriched in the three key cognition related BP, including long-term memory, learning or memory and memory, and the expression level of Sgk1 was positive related with cognitive performance in the water maze. In conclusion, resistance exercise improved the mental health, cognition and synaptic plasticity of mice. Integrating analysis of mRNA expression profiles in frontal cortex, hippocampus and muscle reveals Sgk1 as the key mediator in brain-muscle crosstalk.

Molecular adaptations in response to exercise training are associated with tissue-specific transcriptomic and epigenomic signatures

Regular exercise has many physical and brain health benefits, yet the molecular mechanisms mediating exercise effects across tissues remain poorly understood. Here we analyzed 400 high-quality DNA methylation, ATAC-seq, and RNA-seq datasets from eight tissues from control and endurance exercise-trained (EET) rats. Integration of baseline datasets mapped the gene location dependence of epigenetic control features and identified differing regulatory landscapes in each tissue. The transcriptional responses to 8 weeks of EET showed little overlap across tissues and predominantly comprised tissue-type enriched genes. We identified sex differences in the transcriptomic and epigenomic changes induced by EET. However, the sex-biased gene responses were linked to shared signaling pathways. We found that many G protein-coupled receptor-encoding genes are regulated by EET, suggesting a role for these receptors in mediating the molecular adaptations to training across tissues. Our findings provide new insights into the mechanisms underlying EET-induced health benefits across organs.

Modulation of the Cardiovascular Effects of Polycyclic Aromatic Hydrocarbons: Physical Exercise as a Protective Strategy

Exposure to polycyclic aromatic hydrocarbons (PAHs) present in air pollution increases cardiovascular risk. On the contrary, physical exercise is a widely used therapeutic approach to mitigate cardiovascular risk, but its efficacy in an environment of air pollution, particularly with PAHs, remains unclear. This study investigates the effects of exercise on inflammation, endothelial dysfunction, and REDOX imbalance due to PAH exposure using a mouse model. Twenty male BALB/c mice were subjected to a mixture of PAHs (phenanthrene, fluoranthene, pyrene) in conjunction with aerobic exercise. The investigation evaluated serum levels of inflammatory cytokines, gene expression linked to inflammatory markers, endothelial dysfunction, and REDOX imbalance in aortic tissues. Furthermore, the study evaluated the expression of the ICAM-1 and VCAM-1 proteins. Exercise led to notable changes in serum inflammatory cytokines, as well as the modulation of genes associated with endothelial dysfunction and REDOX imbalance in aortic tissue. In turn, exercise produced a modulation in the protein expression of ICAM-1 and VCAM-1. The findings implicate the potential of exercise to counter PAH-induced damage, as demonstrated by changes in markers. In conclusion, exercise could mitigate the adverse effects related to exposure to PAHs present in air pollution, as evidenced by changes in inflammatory markers, endothelial dysfunction, and REDOX imbalance.

Which Factors Influence Healthy Aging? A Lesson from the Longevity Village of Bama in China

A growing aging population is associated with increasing incidences of aging-related diseases and socioeconomic burdens. Hence, research into healthy longevity and aging is urgently needed. Longevity is an important phenomenon in healthy aging. The present review summarizes the characteristics of longevity in the elderly population in Bama, China, where the proportion of centenarians is 5.7-fold greater than the international standard. We examined the impact of genetic and environmental factors on longevity from multiple perspectives. We proposed that the phenomenon of longevity in this region is of high value for future investigations in healthy aging and aging-related disease and may provide guidance for fostering the establishment and maintenance of a healthy aging society.

Active Gains in brain Using Exercise During Aging (AGUEDA): protocol for a randomized controlled trial

Alzheimer's disease is currently the leading cause of dementia and one of the most expensive, lethal and severe diseases worldwide. Age-related decline in executive function is widespread and plays a key role in subsequent dementia risk. Physical exercise has been proposed as one of the leading non-pharmaceutical approaches to improve executive function and ameliorate cognitive decline. This single-site, two-arm, single-blinded, randomized controlled trial (RCT) will include 90 cognitively normal older adults, aged 65-80 years old. Participants will be randomized to a 24-week resistance exercise program (3 sessions/week, 60 min/session, n = 45), or a wait-list control group (n = 45) which will be asked to maintain their usual lifestyle. All study outcomes will be assessed at baseline and at 24-weeks after the exercise program, with a subset of selected outcomes assessed at 12-weeks. The primary outcome will be indicated by the change in an executive function composite score assessed with a comprehensive neuropsychological battery and the National Institutes of Health Toolbox Cognition Battery. Secondary outcomes will include changes in brain structure and function and amyloid deposition, other cognitive outcomes, and changes in molecular biomarkers assessed in blood, saliva, and fecal samples, physical function, muscular strength, body composition, mental health, and psychosocial parameters. We expect that the resistance exercise program will have positive effects on executive function and related brain structure and function, and will help to understand the molecular, structural, functional, and psychosocial mechanisms involved.

Early-life exercise primes the murine neural epigenome to facilitate gene expression and hippocampal memory consolidation

Aerobic exercise is well known to promote neuroplasticity and hippocampal memory. In the developing brain, early-life exercise (ELE) can lead to persistent improvements in hippocampal function, yet molecular mechanisms underlying this phenomenon have not been fully explored. In this study, transgenic mice harboring the "NuTRAP" (Nuclear tagging and Translating Ribosome Affinity Purification) cassette in Emx1 expressing neurons ("Emx1-NuTRAP" mice) undergo ELE during adolescence. We then simultaneously isolate and sequence translating mRNA and nuclear chromatin from single hippocampal homogenates containing Emx1-expressing neurons. This approach allowed us to couple translatomic with epigenomic sequencing data to evaluate the influence of histone modifications H4K8ac and H3K27me3 on translating mRNA after ELE. A subset of ELE mice underwent a hippocampal learning task to determine the gene expression and epigenetic underpinnings of ELE's contribution to improved hippocampal memory performance. From this experiment, we discover gene expression - histone modification relationships that may play a critical role in facilitated memory after ELE. Our data reveal candidate gene-histone modification interactions and implicate gene regulatory pathways involved in ELE's impact on hippocampal memory.

Exercise sustains the hallmarks of health

Exercise has long been known for its active role in improving physical fitness and sustaining health. Regular moderate-intensity exercise improves all aspects of human health and is widely accepted as a preventative and therapeutic strategy for various diseases. It is well-documented that exercise maintains and restores homeostasis at the organismal, tissue, cellular, and molecular levels to stimulate positive physiological adaptations that consequently protect against various pathological conditions. Here we mainly summarize how moderate-intensity exercise affects the major hallmarks of health, including the integrity of barriers, containment of local perturbations, recycling and turnover, integration of circuitries, rhythmic oscillations, homeostatic resilience, hormetic regulation, as well as repair and regeneration. Furthermore, we summarize the current understanding of the mechanisms responsible for beneficial adaptations in response to exercise. This review aimed at providing a comprehensive summary of the vital biological mechanisms through which moderate-intensity exercise maintains health and opens a window for its application in other health interventions. We hope that continuing investigation in this field will further increase our understanding of the processes involved in the positive role of moderate-intensity exercise and thus get us closer to the identification of new therapeutics that improve quality of life.

The Relationship Between Physical Activity and Mobile Phone Addiction Among Adolescents and Young Adults: Systematic Review and Meta-analysis of Observational Studies

BACKGROUND

Previous studies have reported a potential negative correlation between physical activity (PA) and mobile phone addiction (MPA) among adolescents and young adults. To date, the strength of this correlation has not been well characterized.

OBJECTIVE

This review and meta-analysis aimed to synthesize available empirical studies to examine the correlations between PA and MPA among adolescents and young adults. We also explored several potential moderators, including time of data collection, country or region, and type of population, associated with the relationship between PA and MPA.

METHODS

Four electronic databases (PubMed, Scopus, PsycINFO, and Web of Science) were searched from database inception to March 2022 to identify relevant studies. The pooled Pearson correlation coefficients and their corresponding 95% CIs for the relationship between PA and MPA were calculated using the inverse variance method. The methodological quality of the included cross-sectional studies was determined based on the Joanna Briggs Institute appraisal checklist. The study conformed to the PRISMA (Preferred Reporting Items for Systematic Review and Meta-analyses) guidelines.

RESULTS

In total, 892 relevant articles were identified, of which 22 were selected based on the inclusion and exclusion criteria. The final meta-analysis included 17 of the 22 studies. Results of random effects modeling revealed a moderate correlation between PA and MPA among adolescents and young adults (summary r=-0.243, P<.001). Sensitivity and publication bias analyses further demonstrated the robustness of our results. All the included studies were scored as high quality with a low risk of bias. Subgroup analysis further indicated that none of the hypothesized moderators (time of data collection, country or region, and type of population) significantly affected the relationship between PA and MPA, as confirmed by the mixed effects analysis. In addition, in the data collection subgroups, medium effect sizes were obtained for data collected before COVID-19 (r=-0.333, P<.001) and data collected during COVID-19 (r=-0.207, P<.001). In subgroup analyses for country or region, the correlation coefficient for China and other developing regions showed a similarly moderate effect size (r=-0.201, P<.001 and r= -0.217, P<.001, respectively). However, the effect sizes for developed regions were not significant (r=-0.446, P=.39). In a subgroup analysis based on the type of population, we found that the effect size for young adults was moderate (r=-0.250, P<.001). However, that of adolescents was not significant (r=-0.129, P=.24).

CONCLUSIONS

Our results demonstrate a moderately negative relationship between PA and MPA among young adults. The strength of this relationship was not influenced by the time of data collection, country or region, or type of population.

Chronic exercise remodels the lysine acetylome in the mouse hippocampus

Physical exercise benefits hippocampal function through various molecular mechanisms. Protein acetylation, a conserved and widespread post-translational modification, is involved in the synaptic plasticity and memory. However, whether exercise can change global acetylation and the role of acetylated proteins in the hippocampus have remained largely unknown. Herein, using healthy adult mice running for 6 weeks as exercise model and sedentary mice as control, we analyzed the hippocampal lysine acetylome and proteome by Liquid chromatography-tandem mass spectrometry. As a result, we profiled the lysine acetylation landscape for the hippocampus and identified 3,876 acetyl sites and 1,764 acetylated proteins. A total of 272 acetyl sites on 252 proteins were differentially regulated by chronic exercise, among which 18.58% acetylated proteins were annotated in mitochondria. These proteins were dominantly deacetylated and mainly associated with carbon-related metabolism, the Hippo signaling pathway, ribosomes, and protein processing. Meanwhile, 21 proteins were significantly expressed and enriched in the pathway of complement and coagulation cascades. Our findings provide a new avenue for understanding the molecular mechanisms underlying the benefits of exercise for hippocampal function and can contribute to the promotion of public health.

Making sense of the ageing methylome

Over time, the human DNA methylation landscape accrues substantial damage, which has been associated with a broad range of age-related diseases, including cardiovascular disease and cancer. Various age-related DNA methylation changes have been described, including at the level of individual CpGs, such as differential and variable methylation, and at the level of the whole methylome, including entropy and correlation networks. Here, we review these changes in the ageing methylome as well as the statistical tools that can be used to quantify them. We detail the evidence linking DNA methylation to ageing phenotypes and the longevity strategies aimed at altering both DNA methylation patterns and machinery to extend healthspan and lifespan. Lastly, we discuss theories on the mechanistic causes of epigenetic ageing.