Impacts of exercise interventions on different diseases and organ functions in mice

Potential of synergist ablation to study mechanisms of skeletal muscle hypertrophy in rodent disease models

Synergist ablation (SA) is a well-established model of mechanical overload-induced hypertrophy in rodents, commonly used to infer skeletal muscle adaptation to resistance training in humans. Given the critical role of skeletal muscle atrophy in chronic conditions such as neuromuscular, metabolic, and cardiopulmonary disorders, SA represents a promising preclinical tool to study muscle hypertrophy mechanisms in pathological states. However, although extensively characterized in healthy animals, the potential applications of SA in disease models remain largely overlooked. This Mini-Review summarizes existing studies employing SA in rodent disease models, highlighting the diverse hypertrophic responses observed across conditions, including Duchenne muscular dystrophy, obesity, diabetes, cancer cachexia, and chronic kidney disease. Although hypertrophy gains are generally attenuated in diseased animals compared to healthy controls, SA-induced overload provides valuable insights into disease-specific regulatory mechanisms, including alterations in intracellular signaling, fiber type transitions, and disease phenotype. We also discuss the strengths and limitations of SA as a preclinical model for resistance training in disease contexts and propose its broader adoption for mechanistic investigations into skeletal muscle plasticity under pathological conditions.

Physical exercise alone or combined with omega-3 modulates apical periodontitis induced in rats

Apical periodontitis (AP) results from bacterial contamination of the pulp tissue, with its progression highly influenced by the host's immune response. This study aimed to evaluate the impact of moderate physical exercise, alone or combined with omega-3 supplementation, on AP induced in rats. The analysis focused on the immuno-inflammatory profile, bacterial presence in the root canal and apical region, bone loss, and collagen fiber production. Thirty Wistar rats were divided into three groups: Control, Physical Exercise (PE), and Physical Exercise + Omega-3 (PEO). Omega-3 supplementation was administered by gavage for 60 days. The swimming protocol included two stages: acclimatization to the aquatic environment and swimming training. AP was induced on the 30th day, and the rats were euthanized on the 60th day. Upper molars were processed and stained using Hematoxylin and Eosin (H&E), Brown and Brenn (BB), Picrosirius Red (PSR), and immunohistochemistry for IL-17, TNF-α, and tartrate-resistant acid phosphatase (TRAP). Microtomographic analysis was also performed. Scores from the analyses were evaluated using Kruskal-Wallis, Tukey, Shapiro-Wilk, Mann-Whitney, and One-Way ANOVA tests, with a significance level of 5% (p < 0.05). The control group exhibited the highest intensity of inflammatory infiltrate (p < 0.05). PE alone reduced TNF-α immunostaining and limited bacterial spread (p < 0.05). Combined with omega-3 supplementation, PE further reduced IL-17 immunostaining and increased the percentage of birefringent immature collagen fibers (p < 0.05). Microtomographic analysis revealed smaller areas of alveolar bone loss in animals subjected to PE (p < 0.05). The control group showed a significantly higher number of TRAP-positive cells (p < 0.05). In conclusion, PE alone enhanced defense mechanisms by reducing inflammation through TNF-α modulation and controlling bacterial contamination. Combined with omega-3 supplementation, PE further improved inflammatory regulation by modulating IL-17 levels, reducing bone loss, and stimulating collagen production, thereby limiting inflammation and decreasing osteoclastic activity.

Sex-dependent Pathophysiology and Therapeutic Considerations in Right Heart Disease

Right ventricular (RV) adaptation to the increased afterload in the setting of pulmonary hypertension (PH) and other cardiac and pulmonary vascular conditions is a major determinant of survival. Although the RV remains understudied and less well understood than the left ventricle, recent advances have been made in understanding the function and biology of the RV in health and in disease, particularly in PH. RV adaptation in PH exhibits significant sexual dimorphisms in pathophysiology, adaptation, and outcomes. Despite a higher incidence of PH, women consistently demonstrate better RV adaptation and survival rates in the setting of increased RV afterload compared with men. Sexual dimorphisms extend to therapy responsiveness, with women benefiting more from certain pulmonary vasodilators and exhibiting superior RV recovery. In this review we discuss the current literature on sexual dimorphisms in RV structure, function, and molecular pathways in health and disease, as well as in RV-specific clinical manifestations, treatments, and outcomes in PH. Sex steroid-mediated effects as well as emerging studies on sex steroid-independent effects are reviewed. In general, sex steroids such as 17β-estradiol and dehydroepiandrosterone exert RV-protective effects. In contrast, testosterone negatively impacts RV structure and function. Emerging evidence highlights the influence of nonhormonal genetic determinants, such as BMPR1A and DMRT2 loci, which are associated with better RV function in women. A better understanding of the interplay between sex hormones, genetic factors, and RV biology is crucial for advancing and developing RV-directed therapies for patients of either sex.

Sustained therapeutic effects of self-assembled hyaluronic acid nanoparticles loaded with α-Ketoglutarate in various osteoarthritis stages

Osteoarthritis (OA) is a prevalent degenerative disease characterized by irreversible destruction of articular cartilage, for which no current drugs are known to modify its progression. While intra-articular (IA) injections of hyaluronic acid (HA) offer temporary relief, their effectiveness and long-term benefits are debated. Alpha-ketoglutarate (αKG) has potential chondroprotective properties, but its use is limited by a short half-life and poor cartilage-targeting efficiency. Here, we developed self-assembled HA-αKG nanoparticles (NPs) to combine the benefits of both HA and αKG, showing stability, bioavailability, and sustained pH-responsive release in the knee joint. In both early and advanced OA stages in mice, HA, αKG, and HA-αKG NPs could relieve pain, enhance mobility, and reduce cartilage damage, with HA-αKG NPs demonstrating the best efficacy. Mechanistically, αKG not only promotes cartilage matrix synthesis but also inhibits degradation by activating the PERK-ATF4 signaling pathway to reduce endoplasmic reticulum stress (ERS) in chondrocytes. This study highlights the therapeutic potential of HA-αKG NPs for treating various OA stages, with efficient and sustained effects, suggesting rapid clinical adoption and high acceptability among clinicians and patients.

Getting to the Heart of the Matter: Exploring the Intersection of Cardiovascular Disease, Sex and Race and How Exercise, and Gut Microbiota Influence these Relationships

Cardiovascular disease (CVD) is the leading cause of death worldwide, with physical inactivity being a known contributor to the global rates of CVD incidence. CVD incidence, however, is not uniform with recognized sex differences as well and racial and ethnic differences. Furthermore, gut microbiota have been associated with CVD, sex, and race/ethnicity. Researchers have begun to examine the interplay of these complicated yet interrelated topics. This review will present evidence that CVD (risk and development), and gut microbiota are distinct between the sexes and racial/ethnic groups, which appear to be influenced by acculturation, discrimination, stress, and lifestyle factors like exercise. Furthermore, this review will address the beneficial impacts of exercise on the cardiovascular system and will provide recommendations for future research in the field.

Brain-derived neurotrophic factor levels in morphine-addicted rodents under different exercise protocols: a systematic review and meta-analysis

OBJECTIVES

Exercise might restore morphine-induced behavioural and molecular changes, but related evidence is inconsistent. We conducted a systematic review and meta-analysis of animal studies to elucidate the contribution of brain-derived neurotrophic factor (BDNF) to exercise effects on morphine addiction.

METHODS

We searched papers published until May 25, 2024, in databases, manually searched related references, screened eligible studies, and extracted relevant data. The risk of bias was assessed using the SYstematic Review Centre for Laboratory animal Experimentation (SYRCLE)'s risk bias tool. Subsequently, we summarised study characteristics, reported risks of bias, and conducted a meta-analysis. Subgroup and sensitivity analyses were also conducted.

RESULTS

The meta-analysis showed that exercise increased BDNF levels in morphine-addicted male animals, regardless of the exercise type and intensity. Under morphine addiction, voluntary exercise (running wheel) affected BDNF levels in males, whilst forced exercise (treadmill exercise) did not. Furthermore, different exercise intensities did not affect BDNF levels in males. The sensitivity analysis determined that the results were robust.

CONCLUSIONS

Exercise increased BDNF levels in male but not in female animals. BDNF level changes might be related to the type of exercise but not its intensity. Therefore, BDNF might serve as a biomarker for the effects of different exercise types.

Acute exercise promotes WAT browning by remodeling mRNA m6A methylation

AIMS

Regular exercise promotes the beiging and metabolic adaptations of white adipose tissue (WAT) through the cumulative transcriptional responses that occur after each exercise session. However, the effects of a single bout of acute exercise and the role of N6-methyladenosine (m6A) in these adaptations remain unclear. We aim to investigate this further.

MATERIALS AND METHODS

We constructed mouse models for chronic (8 weeks of running) and acute (single 1-hour run) exercise to study the effects on white adipose tissue (WAT) metabolism and beiging through metabolic phenotyping and transcriptome sequencing. Additionally, we explored the impact of acute exercise on WAT m6A modification and target genes, combining m6A regulators with cell models to elucidate the role of m6A in WAT exercise adaptation.

KEY FINDINGS

Here, we reveal that upregulated m6A modification after acute exercise induces the formation of glycolytic beige fat (g-beige fat) in WAT. Mechanistically, the metabolite β-hydroxybutyrate (BHBA) secreted after acute exercise upregulates m6A modification in WAT. This enhances m6A-dependent translation of the histone acetyltransferase CREBBP, promoting the transcription of key beiging genes by increasing chromatin accessibility. Pharmacologically elevating circulating BHBA mimics the metabolic response induced by acute exercise, upregulating m6A modification and its downstream signals. Additionally, BHBA exhibits long-term effects, improving metabolic homeostasis in obesity by promoting thermogenesis in WAT.

SIGNIFICANCE

Our results reveal the role of metabolites in WAT metabolic adaptation through m6A-mediated chromatin accessibility after acute exercise, providing a novel therapeutic target for regulating WAT metabolism from a nutritional epigenetics perspective.

The mechanisms of exercise improving cardiovascular function by stimulating Piezo1 and TRP ion channels: a systemic review

Mechanosensitive ion channels are widely distributed in the heart, lung, bladder and other tissues, and plays an important role in exercise-induced cardiovascular function promotion. By reviewing the PubMed databases, the results were summarized using the terms "Exercise/Sport", "Piezo1", "Transient receptor potential (TRP)" and "Cardiovascular" as the keywords, 124-related papers screened were sorted and reviewed. The results showed that: (1) Piezo1 and TRP channels play an important role in regulating blood pressure and the development of cardiovascular diseases such as atherosclerosis, myocardial infarction, and cardiac fibrosis; (2) Exercise promotes cardiac health, inhibits the development of pathological heart to heart failure, regulating the changes in the characterization of Piezo1 and TRP channels; (3) Piezo1 activates downstream signaling pathways with very broad pathways, such as AKT/eNOS, NF-κB, p38MAPK and HIPPO-YAP signaling pathways. Piezo1 and Irisin regulate nuclear localization of YAP and are hypothesized to act synergistically to regulate tissue mechanical properties of the cardiovascular system and (4) The cardioprotective effects of exercise through the TRP family are mostly accomplished through Ca2+ and involve many signaling pathways. TRP channels exert their important cardioprotective effects by reducing the TRPC3-Nox2 complex and mediating Irisin-induced Ca2+ influx through TRPV4. It is proposed that exercise stimulates the mechanosensitive cation channel Piezo1 and TRP channels, which exerts cardioprotective effects. The activation of Piezo1 and TRP channels and their downstream targets to exert cardioprotective function by exercise may provide a theoretical basis for the prevention of cardiovascular diseases and the rehabilitation of clinical patients.

Voluntary running exercise promotes maturation differentiation and myelination of oligodendrocytes around Aβ plaques in the medial prefrontal cortex of APP/PS1 mice

BACKGROUND

Previous studies have reported that running exercise could improves myelinization in hippocampus. However, the effects of running exercise on the differentiation and maturation of oligodendrocytes, and myelination surrounding Aβ plaques in the medial prefrontal cortex (mPFC) of the Alzheimer's disease (AD) brain have not been reported.

METHODS

Forty 10-month-old male APP/PS1 AD mice were randomly divided into the AD group and the AD running (AD+RUN) group, while 20 age-matched wild-type littermate mice were included in the WT group. The running group received three-month voluntary running exercise in a running cage, while the AD and WT groups were untreated. After the exercise intervention, all mice were given behavioral tests. The total number of mature oligodendrocytes (CC1+) in the mPFC of mice was precisely quantified using unbiased stereology. Myelin basic protein (MBP) and Aβ plaque, as well as the fluorescence area of MBP surrounding Aβ plaques, and the density and morphology of PDGFα+ cells in the mPFC were analyzed using immunofluorescence.

RESULTS

The levels of working memory, cognitive memory, spatial learning and memory ability were decreased significantly in the AD group compared to the WT group, while these functions were significantly improved in the AD+RUN group compared to the AD group. The Aβ plaques in the mPFC were significantly reduced in the AD+RUN group compared to the AD group. The total number of CC1+ cells and the percentage of MBP fluorescence area surrounding Aβ plaques in the mPFC were significantly lower in the AD group compared to the WT group, but they were significantly higher in the AD+RUN group compared to the AD group. The density and branching complexity of PDGFα+ cells surrounding Aβ plaques in the mPFC were significantly higher in the AD group than in the WT group, while the AD+RUN group showed significantly lower density and branching complexity than the AD group. Changes in MBP expression around Aβ plaques, cell density and cell branching complexity of PDGFα+ cells around Aβ plaques were closely related to the number of Aβ plaques in mPFC, and they were also closely related to behavioral changes in mice.

CONCLUSIONS

Voluntary running exercise could reduce Aβ plaque deposition and promote the maturation and myelination capacity of oligodendrocytes surrounding Aβ plaques in the mPFC of AD mice, thereby improving the learning and memory abilities of APP/PS1 transgenic AD mice.

Voluntary exercise suppresses inflammation and improves insulin resistance in the arcuate nucleus and ventral tegmental area in mice on a high-fat diet

A high-fat diet (HFD) causes inflammation with an increase in microglial activity in the hypothalamic arcuate nucleus (ARC) and ventral tegmental area (VTA), resulting in insulin resistance in both regions. This leads to a deterioration in glucose and energy metabolism. The effect of voluntary exercise on HFD-induced inflammation in the central nervous system (CNS) remains unclear. To clarify the effects of voluntary exercise on the CNS, 8-week-old male C57BL6 mice were fed a chow diet (CHD) or HFD for 4 weeks; each group was further divided into running exercise (EX+) on a wheel and no exercise (EX-) groups. The expression of the inflammatory cytokine, tumor necrosis factor alpha (TNFα), in the ARC and VTA was significantly increased in the HFD/EX- group, with an increase of microglial activity noted, compared to the CHD/EX- group. The expression of TNFα was significantly suppressed, with a decrease of microglial activity, in the HFD/EX+ compared to HFD/EX- group. Insulin resistance in the ARC and VTA was improved with the suppression of TNFα expression. The HFD/EX- group showed significant weight gain and impaired glucose metabolism compared to the CHD/EX- group. The HFD/EX+ group showed an improvement in glucose and energy metabolism compared to the HFD/EX- group. In addition, voluntary wheel running suppressed HFD-induced inflammation in the ARC, with a decrease in microglial activity observed independently of weight changes. Our data suggest that voluntary exercise prevents obesity and improves glucose metabolism by suppressing inflammation in the ARC and VTA under HFD conditions.

Prrx1-driven LINC complex disruption in vivo reduces osteoid deposition but not bone quality after voluntary wheel running

The Linker of Nucleoskeleton and Cytoskeleton (LINC) complex serves to connect the nuclear envelope and the cytoskeleton, influencing cellular processes such as nuclear arrangement, architecture, and mechanotransduction. The role LINC plays in mechanotransduction pathways in bone progenitor cells has been well studied; however, the mechanisms by which LINC complexes govern in vivo bone formation remain less clear. To bridge this knowledge gap, we established a murine model disrupting LINC using transgenic Prx-Cre mice and floxed Tg(CAG-LacZ/EGFP-KASH2) mice. Prx-Cre mice express the Cre recombinase enzyme controlled by the paired-related homeobox gene-1 promoter (Prrx1), a pivotal regulator of skeletal development. Prx-Cre animals have been widely used in the bone field to target bone progenitor cells. Tg(CAG-LacZ/EGFP-KASH2) mice carry a lox-stop-lox flanked LacZ gene allowing for the overexpression of an EGFP-KASH2 fusion protein via cre recombinase mediated deletion of the LacZ cassette. This disrupts endogenous Nesprin-Sun binding in a dominant negative manner disconnecting nesprin from the nuclear envelope. By combining these lines, we generated a Prrx1(+) cell-specific LINC disruption model to study its impact on the developing skeleton and subsequently exercise-induced bone accrual. The findings presented here indicate Prx-driven LINC disruption (PDLD) cells exhibit no change in osteogenic and adipogenic potential compared to controls in vitro nor are there bone quality changes when compared to in sedentary animals at 8 weeks. While PDLD animals displayed increased voluntary running activity andPrrx1(+) cell-specific LINC disruption abolished the exercise-induced increases in osteoid volume and surface after a 6-week exercise intervention, no other changes in bone microarchitecture or mechanical properties were found.

Regular exercise suppresses steatosis-associated liver cancer development by degrading E2F1 and c-Myc via circadian gene upregulation

Regular exercise is believed to suppress cancer progression. However, the precise molecular mechanisms by which exercise prevents cancer development remain unclear. In this study, using a steatosis-associated liver cancer mouse model, we found that regular exercise at a speed of 18 m/min for 20 min daily suppressed liver cancer development. To explore the underlying mechanisms, we examined the gene expression profiles in the livers of the exercise and non-exercise groups. The expressions of circadian genes, such as Per1 and Cry2, were upregulated in the exercise group. As circadian rhythm disruption is known to cause various diseases, including cancer, improving circadian rhythm through exercise could contribute to cancer prevention. We further found that the expression of a series of E2F1 and c-Myc target genes that directly affect the proliferation of cancer cells was downregulated in the exercise group. However, the expression of E2F1 and c-Myc was transcriptionally unchanged but degraded at the post-translational level by exercise. Cry2, which is regulated by the Skp1-Cul1-FBXL3 (SCFFBXL3) ubiquitin ligase complex by binding to FBXL3, can form a complex with E2F1 and c-Myc, which we think is the mechanism to degrade them. Our study revealed a previously unknown mechanism by which exercise prevents cancer development.

Exercise as a Therapeutic Strategy for Obesity: Central and Peripheral Mechanisms

Obesity is a complex, multifactorial condition involving excessive fat accumulation due to an imbalance between energy intake and expenditure, with its global prevalence steadily rising. This condition significantly increases the risk of chronic diseases, including sarcopenia, type 2 diabetes, and cardiovascular diseases, highlighting the need for effective interventions. Exercise has emerged as a potent non-pharmacological approach to combat obesity, targeting both central and peripheral mechanisms that regulate metabolism, energy expenditure, and neurological functions. In the central nervous system, exercise influences appetite, mood, and cognitive functions by modulating the reward system and regulating appetite-controlling hormones to manage energy intake. Concurrently, exercise promotes thermogenesis in adipose tissue and regulates endocrine path-ways and key metabolic organs, such as skeletal muscle and the liver, to enhance fat oxidation and support energy balance. Despite advances in understanding exercise's role in obesity, the precise interaction between the neurobiological and peripheral metabolic pathways remains underexplored, particularly in public health strategies. A better understanding of these interactions could inform more comprehensive obesity management approaches by addressing both central nervous system influences on behavior and peripheral metabolic regulation. This review synthesizes recent insights into these roles, highlighting potential therapeutic strategies targeting both systems for more effective obesity interventions.

The therapeutic effect and possible mechanisms of alginate oligosaccharide on metabolic syndrome by regulating gut microbiota

Metabolic syndrome (MetS) is a disease condition incorporating the abnormal accumulation of various metabolic components, including overweight or abdominal obesity, insulin resistance and abnormal glucose tolerance, hypertension, atherosclerosis, or dyslipidemia. It has been proved that the gut microbiota and microbial-derived products play an important role in regulating lipid metabolism and thus the onset and development of MetS. Previous studies have demonstrated that oligosaccharides with prebiotic effects, such as chitosan oligosaccharides, can regulate the structure of the microbial community and its derived products to control weight and reduce MetS associated with obesity. Alginate oligosaccharides (AOS), natural products extracted from degraded alginate salts with high solubility and extensive biological activity, have also been found to modulate gut microbiota. This review aims to summarize experimental evidence on the positive effects of AOS on different types of MetS while providing insights into mechanisms through which AOS regulates gut microbiota for preventing and treating MetS.

Physical Activity Decreases Inflammation and Delays the Development of Obesity-Associated Pancreatic Ductal Adenocarcinoma

Obesity is a risk factor for pancreatic ductal adenocarcinoma (PDAC), a deadly disease with limited preventive strategies. Lifestyle interventions to decrease obesity represent a potential approach to prevent obesity-associated PDAC. In this study, we examined whether decreasing obesity through physical activity (PA) and/or dietary changes could decrease inflammation in humans and prevent obesity-associated PDAC in mice. Comparison of circulating inflammatory-associated cytokines in subjects (overweight and obese) before and after a PA intervention revealed PA lowered systemic inflammatory cytokines. Mice with pancreatic-specific inducible KrasG12D expression were exposed to PA and/or dietary interventions during and after obesity-associated cancer initiation. In mice with concurrent diet-induced obesity and KrasG12D expression, the PA intervention led to lower weight gain, suppressed systemic inflammation, delayed tumor progression, and decreased proinflammatory signals in the adipose tissue. However, these benefits were not as evident when obesity preceded pancreatic KrasG12D expression. Combining PA with diet-induced weight loss (DI-WL) delayed obesity-associated PDAC progression in the genetically engineered mouse model, but neither PA alone nor combined with DI-WL or chemotherapy prevented PDAC tumor growth in orthotopic PDAC models regardless of obesity status. PA led to the upregulation of Il15ra in adipose tissue. Adipose-specific overexpression of Il15 slowed PDAC growth but only in nonobese mice. Overall, our study suggests that PA alone or combined with DI-WL can reduce inflammation and delay obesity-associated PDAC development or progression. Lifestyle interventions that prevent or manage obesity or therapies that target weight loss-related molecular pathways could prevent progression of PDAC. Significance: Physical activity reduces inflammation and induces changes to adipose-related signaling to suppress pancreatic cancer, supporting the potential of obesity management strategies to reduce the risk of developing pancreatic cancer. See related commentary by Sogunro and Muzumdar, p. 2935.

The Combination of Exercise and Konjac Glucomannan More Effectively Prevents Antibiotics-Induced Dysbiosis in Mice Compared with Singular Intervention

Our previous studies have demonstrated that konjac glucomannan (KGM) can prevent dysbiosis induced by antibiotics. While exercise may also impact the gut microbiome, there are limited studies reporting its protective effect on antibiotic-induced dysbiosis. Therefore, this study investigated the preventive and regulatory effects of a combination of 6-week exercise and KGM intervention on antibiotic-induced dysbiosis in C57BL/6J mice compared with a single intervention. The results showed that combined exercise and KGM intervention could restore the changes in the relative abundance of Bacteroides (3.73% with CTL versus 14.23% with ATBX versus 4.46% with EK) and Prevotellaceae_Prevotella (0.33% with CTL versus 0.00% with ATBX versus 0.30% with EK) induced by antibiotics (p < 0.05), and minimized the Bray-Curtis distance induced by antibiotics (0.55 with CTL versus 0.81 with ATBX versus 0.80 with EXC versus 0.83 with KGM versus 0.75 with EK). Compared with the combined intervention, exercise intervention also produced a certain level of recovery effects; the relative abundance of Rikenellaceae (1.96% with CTL versus 0.09% with ATBX versus 0.49% with EXC) was restored, while KGM supplementation showed the best preventive effect. In addition, the combination of exercise and KGM significantly enriched microbial purine metabolic pathways (p < 0.05). These findings indicate that combining exercise with KGM could be a promising approach to reducing the side effects of antibiotics on the gut microbiome.

Osterix-driven LINC complex disruption in vivo diminishes osteogenesis at 8 weeks but not at 15 weeks

The Linker of Nucleoskeleton and Cytoskeleton (LINC) complex is a crucial connective component between the nuclear envelope and the cytoskeleton involving various cellular processes including nuclear positioning, nuclear architecture, and mechanotransduction. How LINC complexes regulate bone formation in vivo, however, is not well understood. To start bridging this gap, here we created a LINC disruption murine model using transgenic mice expressing Cre recombinase enzyme under the control of the Osterix (Osx-Cre) which is primarily active in pre-osteoblasts and floxed Tg(CAG-LacZ/EGFP-KASH2) mice. Tg(CAG-LacZ/EGFP-KASH2) mice contain a lox-STOP-lox flanked LacZ gene which is deleted upon cre recombination allowing for the overexpression of an EGFP-KASH2 fusion protein. This overexpressed protein disrupts endogenous Nesprin-Sun binding leading to disruption of LINC complexes. Thus, crossing these two lines results in an  Osx- driven  LINC  disruption (ODLD) specific to pre-osteoblasts. In this study, we investigated how this LINC disruption affects exercise-induced bone accrual. ODLD cells had decreased osteogenic and adipogenic potential in vitro compared to non-disrupted controls and sedentary ODLD mice showed decreased bone quality at 8 weeks. Upon access to a voluntary running wheel, ODLD animals showed increased running time and distance; however, our 6-week exercise intervention did not significantly affect bone microarchitecture and bone mechanical properties.

Physical exercise for brain plasticity promotion an overview of the underlying oscillatory mechanism

The global recognition of the importance of physical exercise (PE) for human health has resulted in increased research on its effects on cortical activity. Neural oscillations, which are prominent features of brain activity, serve as crucial indicators for studying the effects of PE on brain function. Existing studies support the idea that PE modifies various types of neural oscillations. While EEG-related literature in exercise science exists, a comprehensive review of the effects of exercise specifically in healthy populations has not yet been conducted. Given the demonstrated influence of exercise on neural plasticity, particularly cortical oscillatory activity, it is imperative to consolidate research on this phenomenon. Therefore, this review aims to summarize numerous PE studies on neuromodulatory mechanisms in the brain over the past decade, covering (1) effects of resistance and aerobic training on brain health via neural oscillations; (2) how mind-body exercise affects human neural activity and cognitive functioning; (3) age-Related effects of PE on brain health and neurodegenerative disease rehabilitation via neural oscillation mechanisms; and (4) conclusion and future direction. In conclusion, the effect of PE on cortical activity is a multifaceted process, and this review seeks to comprehensively examine and summarize existing studies' understanding of how PE regulates neural activity in the brain, providing a more scientific theoretical foundation for the development of personalized PE programs and further research.

Rehabilitation for spinal muscular atrophy patients in China: a national cross-sectional study

BACKGROUND

The management of Spinal Muscular Atrophy (SMA) requires a multidisciplinary treatment approach, wherein rehabilitation constitutes an integral element. In this study, we examined the effects of rehabilitation among Chinese SMA patients and assessed the real-world efficacy of rehabilitation interventions.

METHODS

We conducted a cross-sectional online survey on SMA patients from June 9, 2023, to June 30, 2023, through the Meier Advocacy & Support Center using data from the Center's database and electronic questionnaires. The rehabilitation situation of the participants over the past 14 months were investigated. Logistic binary regression was used to analyze the relationship between Pediatric Quality of Life Inventory(PedsQL™) scores and rehabilitation.

RESULT

A total of 186 questionnaires were finally analyzed. Only 29 patients did not rehabilitated in the past 14 months. A significant correlation between age and type of rehabilitation, as well as between age and duration of rehabilitation. Patients receiving no rehabilitation or solely home-based rehabilitation exhibited a higher median age of 8.4 compared to those undergoing standard rehabilitation or a combination of standard and home-based rehabilitation, with a median age of 4.9 (z-score = -4.49, p-value < 0.001). In addition, long-term rehabilitation (OR = 0.314, 95%CI = 0.106-0.927, p = 0.04) were negatively correlated with lower PedsQL™ Neuromuscular Module scores, and PedsQL scores in the long-term rehabilitation group were higher than those in the short-term and no-rehabilitation groups (54.2 ± 15.1 vs. 45.9 ± 14.4 and 42.3 ± 14.3, p = 0.01), with the most significant difference observed in the physical function section (59.0 ± 15.8 vs. 46.8 ± 15.2 and 45.6 ± 15.9, p < 0.01). Mobility and exercise (OR = 0.26, 95%CI = 0.08-0.81, p = 0.02), as well as assistive technology (OR = 0.28, 95%CI = 0.10-0.82, p = 0.02), were independently associated with a lower score in a negative direction.

CONCLUSION

The study found that long-term rehabilitation was linked to higher PedsQL scores in SMA patients, highlighting the need for standardized rehabilitation programs to enhance function and quality of life.

Aerobic exercise-induced HIF-1α upregulation in heart failure: exploring potential impacts on MCT1 and MPC1 regulation

BACKGROUND

The terminal stage of ischemic heart disease develops into heart failure (HF), which is characterized by hypoxia and metabolic disturbances in cardiomyocytes. The hypoxic failing heart triggers hypoxia-inducible factor-1α (HIF-1α) actions in the cells sensitized to hypoxia and induces metabolic adaptation by accumulating HIF-1α. Furthermore, soluble monocarboxylic acid transporter protein 1 (MCT1) and mitochondrial pyruvate carrier 1 (MPC1), as key nodes of metabolic adaptation, affect metabolic homeostasis in the failing rat heart. Aerobic exercise training has been reported to retard the progression of HF due to enhancing HIF-1α levels as well as MCT1 expressions, whereas the effects of exercise on MCT1 and MPC1 in HF (hypoxia) remain elusive. This research aimed to investigate the action of exercise associated with MCT1 and MPC1 on HF under hypoxia.

METHODS

The experimental rat models are composed of four study groups: sham stented (SHAM), HF sedentary (HF), HF short-term exercise trained (HF-E1), HF long-term exercise trained (HF-E2). HF was initiated via left anterior descending coronary artery ligation, the effects of exercise on the progression of HF were analyzed by ventricular ultrasound (ejection fraction, fractional shortening) and histological staining. The regulatory effects of HIF-1α on cell growth, MCT1 and MPC1 protein expression in hypoxic H9c2 cells were evaluated by HIF-1α activatort/inhibitor treatment and plasmid transfection.

RESULTS

Our results indicate the presence of severe pathological remodelling (as evidenced by deep myocardial fibrosis, increased infarct size and abnormal hypertrophy of the myocardium, etc.) and reduced cardiac function in the failing hearts of rats in the HF group compared to the SHAM group. Treadmill exercise training ameliorated myocardial infarction (MI)-induced cardiac pathological remodelling and enhanced cardiac function in HF exercise group rats, and significantly increased the expression of HIF-1α (p < 0.05), MCT1 (p < 0.01) and MPC1 (p < 0.05) proteins compared to HF group rats. Moreover, pharmacological inhibition of HIF-1α in hypoxic H9c2 cells dramatically downregulated MCT1 and MPC1 protein expression. This phenomenon is consistent with knockdown of HIF-1α at the gene level.

CONCLUSION

The findings propose that long-term aerobic exercise training, as a non- pharmacological treatment, is efficient enough to debilitate the disease process, improve the pathological phenotype, and reinstate cardiac function in HF rats. This benefit is most likely due to activation of myocardial HIF-1α and upregulation of MCT1 and MPC1.

Long-Term High-Fat Diet Limits the Protective Effect of Spontaneous Physical Activity on Mammary Carcinogenesis

Breast cancer is influenced by factors such as diet, a sedentary lifestyle, obesity, and postmenopausal status, which are all linked to prolonged hormonal and inflammatory exposure. Physical activity offers protection against breast cancer by modulating hormones, immune responses, and oxidative defenses. This study aimed to assess how a prolonged high-fat diet (HFD) affects the effectiveness of physical activity in preventing and managing mammary tumorigenesis. Ovariectomised C57BL/6 mice were provided with an enriched environment to induce spontaneous physical activity while being fed HFD. After 44 days (short-term, ST HFD) or 88 days (long-term, LT HFD), syngenic EO771 cells were implanted into mammary glands, and tumour growth was monitored until sacrifice. Despite similar physical activity and food intake, the LT HFD group exhibited higher visceral adipose tissue mass and reduced skeletal muscle mass. In the tumour microenvironment, the LT HFD group showed decreased NK cells and TCD8+ cells, with a trend toward increased T regulatory cells, leading to a collapse of the T8/Treg ratio. Additionally, the LT HFD group displayed decreased tumour triglyceride content and altered enzyme activities indicative of oxidative stress. Prolonged exposure to HFD was associated with tumour growth despite elevated physical activity, promoting a tolerogenic tumour microenvironment. Future studies should explore inter-organ exchanges between tumour and tissues.

The Influence of Exercise on Cancer Risk, the Tumor Microenvironment and the Treatment of Cancer

There are several modifiable factors that can be targeted to prevent and manage the occurrence and progression of cancer, and maintaining adequate exercise is a crucial one. Regular physical exercise has been shown to be a beneficial strategy in preventing cancer, potentially amplifying the effectiveness of established cancer therapies, alleviating certain cancer-related symptoms, and possibly mitigating side effects resulting from treatment. Nevertheless, the exact mechanisms by which exercise affects tumors, especially its impact on the tumor microenvironment (TME), remain uncertain. This review aims to present an overview of the beneficial effects of exercise in the context of cancer management, followed by a summary of the exercise parameters, especially exercise intensity, that need to be considered when prescribing exercise for cancer patients. Finally, we discuss the influence of exercise on the TME, including its effects on crucial immune cells (e.g., T cells, macrophages, neutrophils, natural killer cells, myeloid-derived suppressor cells, B cells), intratumor angiogenesis, and cancer metabolism. This comprehensive review provides up-to-date scientific evidence on the effects of exercise training on cancer and offers guidance to clinicians for the development of safe and feasible exercise training programs for cancer patients in clinical practice.

Prrx1-driven LINC complex disruption in vivo reduces osteoid deposition but not bone quality after voluntary wheel running

The Linker of Nucleoskeleton and Cytoskeleton (LINC) complex serves to connect the nuclear envelope and the cytoskeleton, influencing cellular processes such as nuclear arrangement, architecture, and mechanotransduction. The role LINC plays in mechanotransduction pathways in bone progenitor cells has been well studied; however, the mechanisms by which LINC complexes govern in vivo bone formation remain less clear. To bridge this knowledge gap, we established a murine model disrupting LINC using transgenic Prx-Cre mice and floxed Tg(CAG-LacZ/EGFP-KASH2) mice. Prx-Cre mice express the Cre recombinase enzyme controlled by the paired-related homeobox gene-1 promoter (Prrx1), a pivotal regulator of skeletal development. Prx-Cre animals have been widely used in the bone field to target bone progenitor cells. Tg(CAG-LacZ/EGFP-KASH2) mice carry a lox-stop-lox flanked LacZ gene allowing for the overexpression of an EGFP-KASH2 fusion protein via cre recombinase mediated deletion of the LacZ cassette. This disrupts endogenous Nesprin-Sun binding in a dominant negative manner disconnecting nesprin from the nuclear envelope. By combining these lines, we generated a Prrx1(+) cell-specific LINC disruption model to study its impact on the developing skeleton and subsequently exercise-induced bone accrual. The findings presented here indicate Prx-driven LINC disruption (PDLD) cells exhibit no change in osteogenic and adipogenic potential compared to controls in vitro nor are there bone quality changes when compared to in sedentary animals at 8 weeks. While PDLD animals displayed increased voluntary running activity andPrrx1(+) cell-specific LINC disruption abolished the exercise-induced increases in osteoid volume and surface after a 6-week exercise intervention, no other changes in bone microarchitecture or mechanical properties were found.

Treadmill training impacts the skeletal muscle molecular clock after ischemia stroke in rats

Objective

Stroke is frequently associated with muscle mass loss. Treadmill training is considered the most effective treatment for sarcopenia. Circadian rhythms are closely related to exercise and have been extensively studied. The skeletal muscle has its molecular clock genes. Exercise may regulate skeletal muscle clock genes. This study evaluated the effects of early treadmill training on the skeletal muscle molecular clock machinery in rats with stroke and determined the relationship of these changes with exercise-induced improvements in skeletal muscle health.

Materials and methods

Overall, 168 Sprague-Dawley rats were included in this study. We established an ischemic stroke rat model of sarcopenia. Finally, 144 rats were randomly allocated to four groups (36 per group): normal, sham, middle cerebral artery occlusion, and training. Neurological scores, rotating rod test, body weight, muscle circumference, wet weight, and hematoxylin-eosin staining were assessed. Twenty-four rats were used for transcriptome sequencing. Gene and protein expressions of skeletal muscles, such as brain muscle arnt-like 1, period 1, and period 2, were measured by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assays.

Results

Neurological function scores and rotating rod test results improved after treadmill training. Nine differentially expressed genes were identified by comparing the sham group with the hemiplegic side of the model group. Seventeen differentially expressed genes were identified between the hemiplegic and non-hemiplegic sides. BMAL1, PER1, and PER2 mRNA levels increased on both sides after treadmill training. BMAL1 expression increased, and PER1 expression decreased on both sides, whereas PER2 expression decreased on the hemiplegic side but increased on the non-hemiplegic side.

Conclusion

Treadmill training can mitigate muscle loss and regulate skeletal muscle clock gene expression following ischemic stroke. Exercise affects the hemiplegic side and has a positive regulatory effect on the non-hemiplegic side.

The paradigm change from reactive medical services to 3PM in ischemic stroke: a holistic approach utilising tear fluid multi-omics, mitochondria as a vital biosensor and AI-based multi-professional data interpretation

Worldwide stroke is the second leading cause of death and the third leading cause of death and disability combined. The estimated global economic burden by stroke is over US$891 billion per year. Within three decades (1990-2019), the incidence increased by 70%, deaths by 43%, prevalence by 102%, and DALYs by 143%. Of over 100 million people affected by stroke, about 76% are ischemic stroke (IS) patients recorded worldwide. Contextually, ischemic stroke moves into particular focus of multi-professional groups including researchers, healthcare industry, economists, and policy-makers. Risk factors of ischemic stroke demonstrate sufficient space for cost-effective prevention interventions in primary (suboptimal health) and secondary (clinically manifested collateral disorders contributing to stroke risks) care. These risks are interrelated. For example, sedentary lifestyle and toxic environment both cause mitochondrial stress, systemic low-grade inflammation and accelerated ageing; inflammageing is a low-grade inflammation associated with accelerated ageing and poor stroke outcomes. Stress overload, decreased mitochondrial bioenergetics and hypomagnesaemia are associated with systemic vasospasm and ischemic lesions in heart and brain of all age groups including teenagers. Imbalanced dietary patterns poor in folate but rich in red and processed meat, refined grains, and sugary beverages are associated with hyperhomocysteinaemia, systemic inflammation, small vessel disease, and increased IS risks. Ongoing 3PM research towards vulnerable groups in the population promoted by the European Association for Predictive, Preventive and Personalised Medicine (EPMA) demonstrates promising results for the holistic patient-friendly non-invasive approach utilising tear fluid-based health risk assessment, mitochondria as a vital biosensor and AI-based multi-professional data interpretation as reported here by the EPMA expert group. Collected data demonstrate that IS-relevant risks and corresponding molecular pathways are interrelated. For examples, there is an evident overlap between molecular patterns involved in IS and diabetic retinopathy as an early indicator of IS risk in diabetic patients. Just to exemplify some of them such as the 5-aminolevulinic acid/pathway, which are also characteristic for an altered mitophagy patterns, insomnia, stress regulation and modulation of microbiota-gut-brain crosstalk. Further, ceramides are considered mediators of oxidative stress and inflammation in cardiometabolic disease, negatively affecting mitochondrial respiratory chain function and fission/fusion activity, altered sleep-wake behaviour, vascular stiffness and remodelling. Xanthine/pathway regulation is involved in mitochondrial homeostasis and stress-driven anxiety-like behaviour as well as molecular mechanisms of arterial stiffness. In order to assess individual health risks, an application of machine learning (AI tool) is essential for an accurate data interpretation performed by the multiparametric analysis. Aspects presented in the paper include the needs of young populations and elderly, personalised risk assessment in primary and secondary care, cost-efficacy, application of innovative technologies and screening programmes, advanced education measures for professionals and general population-all are essential pillars for the paradigm change from reactive medical services to 3PM in the overall IS management promoted by the EPMA.

Sex-Specific Effect of CARM1 in Skeletal Muscle Adaptations to Exercise

PURPOSE

The purpose of this study was to determine how the intersection of coactivator-associated arginine methyltransferase 1 (CARM1) and biological sex affects skeletal muscle adaptations to chronic physical activity.

METHODS

Twelve-week-old female (F) and male (M) wild-type (WT) and CARM1 skeletal muscle-specific knockout (mKO) mice were randomly assigned to sedentary (SED) or voluntary wheel running (VWR) experimental groups. For 8 wk, the animals in the VWR cohort had volitional access to running wheels. Subsequently, we performed whole-body functional tests, and 48 h later muscles were harvested for molecular analysis. Western blotting, enzyme activity assays, as well as confocal and transmission electron microscopy were used to examine skeletal muscle biology.

RESULTS

Our data reveal a sex-dependent reduction in VWR volume caused by muscle-specific ablation of CARM1, as F CARM1 mKO mice performed less chronic, volitional exercise than their WT counterparts. Regardless of VWR output, exercise-induced adaptations in physiological function were similar between experimental groups. A broad panel of protein arginine methyltransferase (PRMT) biology measurements, including markers of arginine methyltransferase expression and activity, were unaffected by VWR, except for CARM1 and PRMT7 protein levels, which decreased and increased with VWR, respectively. Changes in myofiber morphology and mitochondrial protein content showed similar trends among animals. However, a closer examination of transmission electron microscopy images revealed contrasting responses to VWR in CARM1 mKO mice compared with WT littermates, particularly in mitochondrial size and fractional area.

CONCLUSIONS

The present findings demonstrate that CARM1 mKO reduces daily running volume in F mice, as well as exercise-evoked skeletal muscle mitochondrial plasticity, which indicates that this enzyme plays an essential role in sex-dependent differences in exercise performance and mitochondrial health.

Exercise-induced β-hydroxybutyrate promotes Treg cell differentiation to ameliorate colitis in mice

Increasing attention is being paid to the mechanistic investigation of exercise-associated chronic inflammatory disease improvement. Ulcerative colitis (UC) is one type of chronic inflammatory bowel disease with increasing incidence and prevalence worldwide. It is known that regular moderate aerobic exercise (RMAE) reduces the incidence or risk of UC, and attenuates disease progression in UC patients. However, the mechanisms of this RMAE's benefit are still under investigation. Here, we revealed that β-hydroxybutyrate (β-HB), a metabolite upon prolonged aerobic exercise, could contribute to RMAE preconditioning in retarding dextran sulfate sodium (DSS)-induced mouse colitis. When blocking β-HB production, RMAE preconditioning-induced colitis amelioration was compromised, whereas supplementation of β-HB significantly rescued impaired β-HB production-associated defects. Meanwhile, we found that RMAE preconditioning significantly caused decreased colonic Th17/Treg ratio, which is considered to be important for colitis mitigation; and the downregulated Th17/Treg ratio was associated with β-HB. We further demonstrated that β-HB can directly promote the differentiation of Treg cell rather than inhibit Th17 cell generation. Furthermore, β-HB increased forkhead box protein P3 (Foxp3) expression, the core transcriptional factor for Treg cell, by enhancing histone H3 acetylation in the promoter and conserved noncoding sequences of the Foxp3 locus. In addition, fatty acid oxidation, the key metabolic pathway required for Treg cell differentiation, was enhanced by β-HB treatment. Lastly, administration of β-HB without exercise significantly boosted colonic Treg cell and alleviated colitis in mice. Together, we unveiled a previously unappreciated role for exercise metabolite β-HB in the promotion of Treg cell generation and RMAE preconditioning-associated colitis attenuation.

Swimming behavior indicates stress and adaptations to exercise

Introduction: Behaviors of swimming rodents are not uniform, exhibiting large variations, which may underlie the individual differences in swimming exercise-induced benefits. The study aimed to monitor individualized swimming behavior and evaluate its biological significance. Methods: A swimming tank which can monitor individualized rodent swimming behavior during exercise was established. A total of 45 mice were subjected to swimming training for 1 month (1 h per day) and the swimming behaviors of each mouse were recorded. Results: The swimming behaviors of mice displayed considerable variations in aspects of distance, velocity, and area preference. For example, nearly one-third of mice preferred to swim in central area and most of the mice exhibited an even area distribution. Long-term exercise training improved cardiac systolic function and decreased blood pressure in mice, but hardly changed swimming behaviors. Analyses of the relationship between swimming behavior and cardiovascular adaptations to exercise training revealed that swimming behavior indicated the biological effects of swimming training. Specifically, mice which preferred swimming at the central zone or were trainable in behavior during 1-month training exhibited better outcomes in cardiac function and blood pressure post long-term exercise. Mechanistically, a centralized swimming behavior indicated a smaller stress during exercise, as evidenced by a milder activation of hypothalamic-pituitary-adrenal axis. Discussion: These results suggest that swimming behavior during training indicates individualized adaptations to long-term exercise, and highlight a biological significance of swimming behavior monitoring in animal studies.

Advances in exercise-induced vascular adaptation: mechanisms, models, and methods

Insufficient physical activity poses a significant risk factor for cardiovascular diseases. Exercise plays a crucial role in influencing the vascular system and is essential for maintaining vascular health. Hemodynamic stimuli generated by exercise, such as shear stress and circumferential stress, directly impact vascular structure and function, resulting in adaptive changes. In clinical settings, incorporating appropriate exercise interventions has become a powerful supplementary approach for treating and rehabilitating various cardiovascular conditions. However, existing models for studying exercise-induced vascular adaptation primarily rely on in vivo animal and in vitro cellular models, each with its inherent limitations. In contrast, human research faces challenges in conducting mechanistic analyses due to ethics issues. Therefore, it is imperative to develop highly biomimetic in vitro/ex vivo vascular models that can replicate exercise stimuli in human systems. Utilizing various vascular assessment techniques is also crucial to comprehensively evaluate the effects of exercise on the vasculature and uncover the molecular mechanisms that promote vascular health. This article reviews the hemodynamic mechanisms that underlie exercise-induced vascular adaptation. It explores the advancements in current vascular models and measurement techniques, while addressing their future development and challenges. The overarching goal is to unravel the molecular mechanisms that drive the positive effects of exercise on the cardiovascular system. By providing a scientific rationale and offering novel perspectives, the aim is to contribute to the formulation of precise cardiovascular rehabilitation exercise prescriptions.

Glucose restriction enhances oxidative fiber formation: A multi-omic signal network involving AMPK and CaMK2

Skeletal muscle is a highly plastic organ that adapts to different metabolic states or functional demands. This study explored the impact of permanent glucose restriction (GR) on skeletal muscle composition and metabolism. Using Glut4m mice with defective glucose transporter 4, we conducted multi-omics analyses at different ages and after low-intensity treadmill training. The oxidative fibers were significantly increased in Glut4m muscles. Mechanistically, GR activated AMPK pathway, promoting mitochondrial function and beneficial myokine expression, and facilitated slow fiber formation via CaMK2 pathway. Phosphorylation-activated Perm1 may synergize AMPK and CaMK2 signaling. Besides, MAPK and CDK kinases were also implicated in skeletal muscle protein phosphorylation during GR response. This study provides a comprehensive signaling network demonstrating how GR influences muscle fiber types and metabolic patterns. These insights offer valuable data for understanding oxidative fiber formation mechanisms and identifying clinical targets for metabolic diseases.

Reducing sugar intake through chronic swimming training: Exploring palatability changes and central vasopressin mechanisms

Excessive sugar intake has been associated with the onset of several non-communicable chronic diseases seen in humans. Physical activity could affect sweet taste perception which may affect sugar intake. Therefore, it was investigated the chronic effects of swimming training on sucrose intake/preference, reactivity to sucrose taste, self-care in neurobehavioral stress, and the possible involvement of the vasopressin type V1 receptor in sucrose solution intake. Male Wistar rats, of from different cohorts were used, subjected to a sedentary lifestyle (SED) or swimming training (TR - 1 h/day, 5×/week, for 8 weeks, with no added load). Weekly intake was verified in SED and TR rats after access to a sucrose solution 1×/week, 2 h/day, for eight weeks. Chronic effects of swimming and/or a sedentary lifestyle were carried out three days after the end of the physical exercise protocol. Swimming training reduced the intake of sucrose solution from the third week onwards in the two-bottle test measured once a week for 8 weeks. After the ending of the swimming protocol, sucrose intake was also reduced as per its preference. This reduced intake is probably correlated with the carbohydrate aspect of sucrose since saccharin intake was not affected. In addition, chronic swimming training was shown to reduce ingestive responses, increase neutral responses, without interfering with aversive, in the sucrose solution taste reactivity test. In addition, these results are not related to a depressive-like behavior, nor to neurobehavioral stress. Furthermore, treatment with vasopressin V1 receptor antagonist abolished the reduced sucrose intake in trained rats. The results suggest that swimming performed chronically is capable of reducing intake and preference for sucrose by decreasing the palatability of sucrose without causing depressive-type behavior or stress. In addition, the results also suggest that central V1 vasopressin receptors are part of the mechanisms activated to reduce sucrose intake in trained rats.

Treadmill Exercise Suppresses Histological Progression of Disuse Atrophy in Articular Cartilage in Rat Knee Joints during Hindlimb Suspension

OBJECTIVE

The purpose of this study was to determine the preventive effects of treadmill exercise or physiological loading on disuse atrophy in the rat knee joint cartilage and bone during hindlimb suspension.

DESIGN

Twenty male rats were divided into 4 experimental groups, including the control, hindlimb suspension, physiological loading, and treadmill walking groups. Histological changes in the articular cartilage and bone of the tibia were histomorphometrically and immunohistochemically evaluated 4 weeks after the intervention.

RESULTS

Compared with the control group, the hindlimb suspension group showed thinning of cartilage thickness, decreased matrix staining, and decreased proportion of noncalcified layers. Cartilage thinning, decreased matrix staining, and decreased noncalcified layers were suppressed in the treadmill walking group. The physiological loading group exhibited no significant suppression of cartilage thinning or decreased noncalcified layers, but the decreased matrix staining was significantly suppressed. No significant prevention of bone mass loss or changes in subchondral bone thickness were detected after physiological loading or treadmill walking.

CONCLUSION

Disuse atrophy of the articular cartilage caused by unloading conditions could be prevented by treadmill walking in rat knee joints.

Physiological and Morphometric Differences in Resident Moderate-Altitude vs. Sea-Level Mice

INTRODUCTION: High-altitude [>2400 m (7874 ft)] acclimatization has been well studied with physiological adaptations like reductions in body weight and exercise capacity. However, despite the significance of moderate altitude [MA, 1524-2438 m (5000-8000 ft)], acclimatization at this elevation is not well described. We aimed to investigate differences in mice reared at MA compared to sea level (SL). We hypothesized that MA mice would be smaller and leaner and voluntarily run less than SL mice.METHODS: C57BL/6 mice reared for at least three generations in Laramie, WY [2194 m (7198 ft), MA], were compared to C57BL/6J mice from Bar Harbor, ME [20 m (66 ft), SL]. We quantified body composition and exercise outputs as well as cardiopulmonary morphometrics. Subsets of MA and SL mice were analyzed to determine differences in neuronal activation after exercise.RESULTS: When body weight was normalized to tibia length, SL animals weighed 1.30 g ⋅ mm-1 while MA mice weighed 1.13 g · mm-1. Total fat % and trunk fat % were higher in MA mice with values of 41% and 39%, respectively, compared to SL mice with values of 28% and 26%, respectively. However, no differences were noted in leg fat %. MA animals had higher heart mass (119 mg) and lower lung mass (160 mg) compared to SL mice heart mass (100 mg) and lung mass (177 mg). MA mice engaged in about 40% less voluntary wheel-running activity than SL animals.DISCUSSION: Physiological differences are apparent between MA and SL mice, prompting a need to further understand larger scale implications of residence at moderate altitude.O'Connor AE, Hatzenbiler DM, Flom LT, Bobadilla A-C, Bruns DR, Schmitt EE. Physiological and morphometric differences in resident moderate-altitude vs. sea-level mice. Aerosp Med Hum Perform. 2023; 94(12):887-893.

Critical Velocity, Maximal Lactate Steady State, and Muscle MCT1 and MCT4 after Exhaustive Running in Mice

Although the critical velocity (CV) protocol has been used to determine the aerobic capacity in rodents, there is a lack of studies that compare CV with maximal lactate steady state intensity (iMLSS) in mice. As a consequence, their physiological and molecular responses after exercise until exhaustion at CV intensity remain unclear. Thus, we aimed to compare and correlate CV with iMLSS in running mice, following different mathematical models for CV estimation. We also evaluated their physiological responses and muscle MCT1 and MCT4 after running until exhaustion at CV. Thirty C57BL/6J mice were divided into two groups (exercised-E and control-C). Group E was submitted to a CV protocol (4 days), using linear (lin1 and lin2) and hyperbolic (hyp) mathematical models to determine the distance, velocity, and time to exhaustion (tlim) of each predictive CV trial, followed by an MLSS protocol. After a running effort until exhaustion at CV intensity, the mice were immediately euthanized, while group C was euthanized at rest. No differences were observed between iMLSS (21.1 ± 1.1 m.min-1) and CV estimated by lin1 (21.0 ± 0.9 m.min-1, p = 0.415), lin2 (21.3 ± 0.9 m.min-1, p = 0.209), and hyp (20.6 ± 0.9 m.min-1, p = 0.914). According to the results, CV was significantly correlated with iMLSS. After running until exhaustion at CV (tlim = 28.4 ± 8,29 min), group E showed lower concentrations of hepatic and gluteal glycogen than group C, but no difference in the content of MCT1 (p = 0.933) and MCT4 (p = 0.123) in soleus muscle. Significant correlations were not found between MCT1 and MCT4 and tlim at CV intensity. Our results reinforce that CV is a valid and non-invasive protocol to estimate the maximal aerobic capacity in mice and that the content of MCT1 and MCT4 was not decisive in determining the tlim at CV, at least when measured immediately after the running effort.

Advancing Alzheimer's Therapeutics: Exploring the Impact of Physical Exercise in Animal Models and Patients

Alzheimer's disease (AD) is the main neurodegenerative disorder characterized by several pathophysiological features, including the misfolding of the tau protein and the amyloid beta (Aβ) peptide, neuroinflammation, oxidative stress, synaptic dysfunction, metabolic alterations, and cognitive impairment. These mechanisms collectively contribute to neurodegeneration, necessitating the exploration of therapeutic approaches with multiple targets. Physical exercise has emerged as a promising non-pharmacological intervention for AD, with demonstrated effects on promoting neurogenesis, activating neurotrophic factors, reducing Aβ aggregates, minimizing the formation of neurofibrillary tangles (NFTs), dampening inflammatory processes, mitigating oxidative stress, and improving the functionality of the neurovascular unit (NVU). Overall, the neuroprotective effects of exercise are not singular, but are multi-targets. Numerous studies have investigated physical exercise's potential in both AD patients and animal models, employing various exercise protocols to elucidate the underlying neurobiological mechanisms and effects. The objective of this review is to analyze the neurological therapeutic effects of these exercise protocols in animal models and compare them with studies conducted in AD patients. By translating findings from different approaches, this review aims to identify opportune, specific, and personalized therapeutic windows, thus advancing research on the use of physical exercise with AD patients.

Bioinformatics Analysis and Experimental Verification of Exercise for Aging Mice in Different Brain Regions Based on Transcriptome Sequencing

PURPOSE

Physical exercise mitigates the effects of aging and cognitive decline. However, the precise neurobiological mechanisms underlying this phenomenon remain unclear. The primary aim of this study was to investigate the protective effect of exercise on age-related memory deficits in the prefrontal cortex (PFC) and hippocampus using bioinformatic analysis and biochemical verification.

METHODS

Young and aging mice were subjected to natural feeding or treadmill exercise (12 m/min, 8 weeks). Cognitive function was accessed using the Barnes maze and novel object recognition. Bioinformatic analysis was performed to identify co-expressed genes in different groups and brain regions. The selected genes and pathways were validated using RT-qPCR.

RESULTS

Regular exercise significantly ameliorated age-related cognitive deficits. Four up-regulated targets (Ifi27l2a, Irf7, Oas1b, Ifit1) and one down-regulation (Septin2) were reversed by exercise, demonstrating the underlying mechanisms of cognitive functions induced by aging with exercise in the hippocampus and PFC. The Gene Ontology terms and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses indicated that the NOD-like receptor signaling pathway was inhibited in the neuroinflammation effects of exercise in aging mice in both brain regions.

CONCLUSION

Exercise enhances age-related learning and memory deficits. This beneficial effect may be attributed to the changes in five up/down-regulated genes and the NOD-like receptor signaling pathway in both the hippocampus and PFC. These findings establish the modulation of neuroinflammation as a pivotal molecular mechanism supporting exercise intervention in the brain aging process.

Metabolic crosstalk between skeletal muscle cells and liver through IRF4-FSTL1 in nonalcoholic steatohepatitis

Inter-organ crosstalk has gained increasing attention in recent times; however, the underlying mechanisms remain unclear. In this study, we elucidate an endocrine pathway that is regulated by skeletal muscle interferon regulatory factor (IRF) 4, which manipulates liver pathology. Skeletal muscle specific IRF4 knockout (F4MKO) mice exhibited ameliorated hepatic steatosis, inflammation, and fibrosis, without changes in body weight, when put on a nonalcoholic steatohepatitis (NASH) diet. Proteomics analysis results suggested that follistatin-like protein 1 (FSTL1) may constitute a link between muscles and the liver. Dual luciferase assays showed that IRF4 can transcriptionally regulate FSTL1. Further, inducing FSTL1 expression in the muscles of F4MKO mice is sufficient to restore liver pathology. In addition, co-culture experiments confirmed that FSTL1 plays a distinct role in various liver cell types via different receptors. Finally, we observed that the serum FSTL1 level is positively correlated with NASH progression in humans. These data indicate a signaling pathway involving IRF4-FSTL1-DIP2A/CD14, that links skeletal muscle cells to the liver in the pathogenesis of NASH.

The role of the oxytocin system in the resilience of patients with breast cancer

Breast cancer is a grave traumatic experience that can profoundly compromise patients' psychological resilience, impacting their overall quality of life. The oxytocin system represents one of the essential neurobiological bases of psychological resilience and plays a critical role in regulating resilience in response to social or traumatic events during adulthood. Oxytocin, through its direct interaction with peripheral or central oxytocin receptors, has been found to have a significant impact on regulating social behavior. However, the precise mechanism by which the activation of peripheral oxytocin receptors leads to improved social is still not completely comprehended and requires additional research. Its activation can modulate psychological resilience by influencing estrogen and its receptors, the hypothalamic-pituitary-adrenal axis, thyroid function, 5-hydroxytryptamine metabolism levels, and arginine pressure release in breast cancer patients. Various interventions, including psychotherapy and behavioral measures, have been employed to improve the psychological resilience of breast cancer patients. The potential effectiveness of such interventions may be underpinned by their ability to modulate oxytocin release levels. This review provides an overview of the oxytocin system and resilience in breast cancer patients and identifies possible future research directions and interventions.

Osterix-driven LINC complex disruption in vivo diminishes bone microarchitecture in 8-week male mice but not after 6-week voluntary wheel running

The Linker of Nucleoskeleton and Cytoskeleton (LINC) complex is a crucial connective component between the nuclear envelope and the cytoskeleton involving various cellular processes including nuclear positioning, nuclear architecture, and mechanotransduction. How LINC complexes regulate bone formation in vivo, however, is not well understood. To start bridging this gap, here we created a LINC disruption murine model using transgenic mice expressing Cre recombinase enzyme under the control of the Osterix (Osx-Cre) which is primarily active in pre-osteoblasts and floxed Tg(CAG-LacZ/EGFP-KASH2) mice. Tg(CAG-LacZ/EGFP-KASH2) mice contain a lox-STOP-lox flanked LacZ gene which is deleted upon cre recombination allowing for the overexpression of an EGFP-KASH2 fusion protein. This overexpressed protein disrupts endogenous Nesprin-Sun binding leading to disruption of LINC complexes. Thus, crossing these two lines results in a Osx-driven LINC disruption (ODLD) specific to pre-osteoblasts. In this study, we investigated how this LINC disruption affects exercise induced bone accrual. ODLD cells had decreased osteogenic and adipogenic potential in vitro compared to non-disrupted controls and sedentary ODLD mice showed decreased bone quality at 8-weeks. Upon access to a voluntary running wheel ODLD animals showed increased running time and distance; however, our 6-week exercise intervention did not significantly affect bone microarchitecture and bone mechanical properties.

Adolescent nonpharmacological interventions for early-life stress and their mechanisms

Those with a negative experience of psychosocial stress during the early stage of life not only have a high susceptibility of the psychiatric disorder in all phases of their life span, but they also demonstrate more severe symptoms and poorer response to treatment compared to those without a history of early-life stress. The interventions targeted to early-life stress may improve the effectiveness of treating and preventing psychiatric disorders. Brain regions associated with mood and cognition develop rapidly and own heightened plasticity during adolescence. So, manipulating nonpharmacological interventions in fewer side effects and higher acceptance during adolescence, which is a probable window of opportunity, may ameliorate or even reverse the constantly deteriorating impact of early-life stress. The present article reviews animal and people studies about adolescent nonpharmacological interventions for early-life stress. We aim to discuss whether those adolescent nonpharmacological interventions can promote individuals' psychological health who expose to early-life stress.

Insights into the function of HDAC3 and NCoR1/NCoR2 co-repressor complex in metabolic diseases

Histone deacetylase 3 (HDAC3) and nuclear receptor co-repressor (NCoR1/2) are epigenetic regulators that play a key role in gene expression and metabolism. HDAC3 is a class I histone deacetylase that functions as a transcriptional co-repressor, modulating gene expression by removing acetyl groups from histones and non-histone proteins. NCoR1, on the other hand, is a transcriptional co-repressor that interacts with nuclear hormone receptors, including peroxisome proliferator-activated receptor gamma (PPARγ) and liver X receptor (LXR), to regulate metabolic gene expression. Recent research has revealed a functional link between HDAC3 and NCoR1 in the regulation of metabolic gene expression. Genetic deletion of HDAC3 in mouse models has been shown to improve glucose intolerance and insulin sensitivity in the liver, skeletal muscle, and adipose tissue. Similarly, genetic deletion of NCoR1 has improved insulin resistance and reduced adiposity in mouse models. Dysregulation of this interaction has been associated with the development of cardio-metabolic diseases such as cardiovascular diseases, obesity and type 2 diabetes, suggesting that targeting this pathway may hold promise for the development of novel therapeutic interventions. In this review, we summarize the current understanding of individual functions of HDAC3 and NCoR1/2 and the co-repressor complex formation (HDAC3/NCoR1/2) in different metabolic tissues. Further studies are needed to thoroughly understand the mechanisms through which HDAC3, and NCoR1/2 govern metabolic processes and the implications for treating metabolic diseases.

Sulforaphane Inhibits Exhaustive Exercise-Induced Liver Injury and Transcriptome-Based Mechanism Analysis

Exhaustive exercise (EE) induces liver injury and has recently gained much attention. Sulforaphane (SFN) can protect the liver from inflammation and oxidative stress. However, the effects of SFN on EE-induced liver injury and its underlying mechanisms are still unclear. C57BL/6J mice swimming to exhaustion for seven days were used to simulate the liver injury caused by EE. Different doses of SFN (10, 30, 90 mg/kg body weight) were gavage-fed one week before and during the exercise. SFN intervention significantly reduced the EE-induced lactate dehydrogenase (LDH), creatine kinase (CK), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) in the serum, as well as attenuating liver tissue morphological abnormality, oxidative stress injury, and inflammation. Liver transcriptomic analysis showed that the differentially expressed genes altered by SFN intervention in the exercise model were mainly enriched in glucose and lipid metabolism pathways. The most altered gene by SFN intervention screened by RNA-seq and validated by qRT-PCR is Ppp1r3g, a gene involved in regulating hepatic glycogenesis, which may play a vital role in the protective effects of SFN in EE-induced liver damage. SFN can protect the liver from EE-induced damage, and glucose and lipid metabolism may be involved in the mechanism of the protective effects.

A convolutional neural network to characterize mouse hindlimb foot strikes during voluntary wheel running

Voluntary wheel running (VWR) is widely used to study how exercise impacts a variety of physiologies and pathologies in rodents. The primary activity readout of VWR is aggregated wheel turns over a given time interval (most often, days). Given the typical running frequency of mice (∼4 Hz) and the intermittency of voluntary running, aggregate wheel turn counts, therefore, provide minimal insight into the heterogeneity of voluntary activity. To overcome this limitation, we developed a six-layer convolutional neural network (CNN) to determine the hindlimb foot strike frequency of mice exposed to VWR. Aged female C57BL/6 mice (22 months, n = 6) were first exposed to wireless angled running wheels for 2 h/d, 5 days/wk for 3 weeks with all VWR activities recorded at 30 frames/s. To validate the CNN, we manually classified foot strikes within 4800 1-s videos (800 randomly chosen for each mouse) and converted those values to frequency. Upon iterative optimization of model architecture and training on a subset of classified videos (4400), the CNN model achieved an overall training set accuracy of 94%. Once trained, the CNN was validated on the remaining 400 videos (accuracy: 81%). We then applied transfer learning to the CNN to predict the foot strike frequency of young adult female C57BL6 mice (4 months, n = 6) whose activity and gait differed from old mice during VWR (accuracy: 68%). In summary, we have developed a novel quantitative tool that non-invasively characterizes VWR activity at a much greater resolution than was previously accessible. This enhanced resolution holds potential to overcome a primary barrier to relating intermittent and heterogeneous VWR activity to induced physiological responses.

Conserved multi-tissue transcriptomic adaptations to exercise training in humans and mice

Physical activity is associated with beneficial adaptations in human and rodent metabolism. We studied over 50 complex traits before and after exercise intervention in middle-aged men and a panel of 100 diverse strains of female mice. Candidate gene analyses in three brain regions, muscle, liver, heart, and adipose tissue of mice indicate genetic drivers of clinically relevant traits, including volitional exercise volume, muscle metabolism, adiposity, and hepatic lipids. Although ∼33% of genes differentially expressed in skeletal muscle following the exercise intervention are similar in mice and humans independent of BMI, responsiveness of adipose tissue to exercise-stimulated weight loss appears controlled by species and underlying genotype. We leveraged genetic diversity to generate prediction models of metabolic trait responsiveness to volitional activity offering a framework for advancing personalized exercise prescription. The human and mouse data are publicly available via a user-friendly Web-based application to enhance data mining and hypothesis development.

The effects of voluntary running exercise on the astrocytes of the medial prefrontal cortex in APP/PS1 mice

Pathological changes in the medial prefrontal cortex (mPFC) and astrocytes are closely associated with Alzheimer's disease (AD). Voluntary running has been found to effectively delay AD. However, the effects of voluntary running on mPFC astrocytes in AD are unclear. A total of 40 10-month-old male amyloid precursor protein/presenilin 1 (APP/PS1) mice and 40 wild-type (WT) mice were randomly divided into control and running groups, and the running groups underwent voluntary running for 3 months. Mouse cognition was assessed by the novel object recognition (NOR), Morris water maze (MWM), and Y maze tests. The effects of voluntary running on mPFC astrocytes were investigated using immunohistochemistry, immunofluorescence, western blotting, and stereology. APP/PS1 mice performed significantly worse than WT mice in the NOR, MWM, and Y maze tests, and voluntary running improved the performance of APP/PS1 mice in these tests. The total number of mPFC astrocytes was increased, cell bodies were enlarged, and protrusion number and length were increased in AD mice compared with WT mice, but there was no difference in component 3 (C3) levels in the mPFC (total mPFC level); however, C3 and S100B levels in astrocytes were increased in AD mice. Voluntary running reduced the total number of astrocytes and S100B levels in astrocytes and increased the density of PSD95⁺ puncta in direct contact with astrocyte protrusions in the APP/PS1 mouse mPFC. Three months of voluntary running inhibited astrocyte hyperplasia and S100B expression in astrocytes, increased the density of synapses in contact with astrocytes, and improved cognitive function in APP/PS1 mice.

Swimming training and herbal nanoformulations as natural remedies to improve sensory-motor impairment in rat midbrain tumor models: system biology, behavioral test, and experimental validation

Motor impairment worsens health-related quality of life in patients with primary and metastatic midbrain tumors. Here, 56-male-Wistar rats were divided into eight groups: Normal group, Midbrain Tomur Model group, Model + Exe group, Model + Lipo, Model + Extract, Model + Lipo-Extract, Model + Extract-Exe, Model + Lipo-Extract + Exe. According to the aim, mid-brain tumor models were conducted by injections of the C6 glioma cell line (5 × 105 cell suspension) and stereotaxic techniques in the substantia nigra area. Furthermore, consumption of nanoformulation of herbals extract (100 mg/kg/day), crude extract (100 mg/kg/day), and swimming training (30 min, 3 days/week) as interventional protocols were performed for 6 weeks. In addition, we evaluated the effect of polyherbal nanoliposomes containing four plant extracts and swimming training on the GABArα1/TRKB/DRD2/DRD1a/TH network in the substantia nigra of the midbrain tumor rat model. Data emphasized that DRD2 might be a druggable protein with the network's highest significance cut-point effect that could modulate sensory-motor impairment. Furthermore, we found Quercetin, Ginsenosides, Curcumin, and Rutin, as bioactive compounds present in Ginseng, Matthiola incana, Turmeric, and Green-Tea extracts, could bind over the DRD2 protein with approved binding affinity scores. Based on our data, swimming training, and nanoliposome-enriched combined supplements could consider effective complementary medicine for motor impairment recovery induced by the midbrain tumor in the substantia nigra area. Hence, regular swimming training and natural medicines rich in polyphenolic bioactive components and antioxidative effects could modify and improve the dopamine receptors' function.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-023-03574-3.

Effect of voluntary wheel running on autophagy status in lung tissue of high-fat diet-fed rats

Here, we aimed to explore the therapeutic effect of voluntary wheel running (VWR) in high-fat diet-fed rats on pulmonary tissue injury via the modulation of autophagic response. Thirty-two rats were allocated into four groups; normal diet (Control); VWR; high-fat-diet (HFD), and HFD + VWR. After three months, pathological effect of HFD on pulmonary tissue was investigated. The levels of tumour necrosis factor (TNF)-α were detected in the bronchoalveolar lavage fluid (BALF). We monitored the expression of interleukin (IL)-6 and autophagy-related genes in lung tissues. H&E staining showed pathological changes in HFD group coincided with the increase of TNF-α levels in the bronchoalveolar fluid compared to the normal rats. Our results showed the up-regulation of IL-6, becline-1, LC3 and P62 in the HFD group compared to the Control group. VWR inhibited HFD-induced changes and could decrease HFD-induced changes via the regulation of autophagy status.

Long-term voluntary exercise inhibited AGE/RAGE and microglial activation and reduced the loss of dendritic spines in the hippocampi of APP/PS1 transgenic mice

Alzheimer's disease (AD) is closely related to hippocampal synapse loss, which can be alleviated by running exercise. However, further studies are needed to determine whether running exercise reduces synapse loss in the hippocampus in an AD model by regulating microglia. Ten-month-old male wild-type mice and APP/PS1 mice were randomly divided into control and running groups. All mice in the running groups were subjected to voluntary running exercise for four months. After the behavioral tests, immunohistochemistry, stereological methods, immunofluorescence staining, 3D reconstruction, western blotting and RNA-Seq were performed. Running exercise improved the spatial learning and memory abilities of APP/PS1 mice and increased the total number of dendritic spines, the levels of the PSD-95 and Synapsin Ia/b proteins, the colocalization of PSD-95 and neuronal dendrites (MAP-2) and the number of PSD-95-contacting astrocytes (GFAP) in the hippocampi of APP/PS1 mice. Moreover, running exercise reduced the relative expression of CD68 and Iba-1, the number of Iba-1⁺ microglia and the colocalization of PSD-95 and Iba-1⁺ microglia in the hippocampi of APP/PS1 mice. The RNA-Seq results showed that some differentially expressed genes (DEGs) related to the complement system (Cd59b, Serping1, Cfh, A2m, and Trem2) were upregulated in the hippocampi of APP/PS1 mice, while running exercise downregulated the C3 gene. At the protein level, running exercise also reduced the expression of advanced glycation end products (AGEs), receptor for advanced glycation end products (RAGE), C1q and C3 in the hippocampus and AGEs and RAGE in hippocampal microglia in APP/PS1 mice. Furthermore, the Col6a3, Scn5a, Cxcl5, Tdg and Clec4n genes were upregulated in the hippocampi of APP/PS1 mice but downregulated after running, and these genes were associated with the C3 and RAGE genes according to protein-protein interaction (PPI) analysis. These findings indicate that long-term voluntary exercise might protect hippocampal synapses and affect the function and activation of microglia, the AGE/RAGE signaling pathway in microglia and the C1q/C3 complement system in the hippocampus in APP/PS1 mice, and these effects may be related to the Col6a3, Scn5a, Cxcl5, Tdg and Clec4n genes. The current results provide an important basis for identifying targets for the prevention and treatment of AD.