Abstract:The two core causes of obesity in modern lifestyle are high-fat diet (HFD) and insufficient physical activity. HFD can lead to disruption of gut microbiota and abnormal lipid metabolism, further exacerbating the process of obesity. The small intestine, as the "first checkpoint" for the digestion and absorption of dietary lipids into the body, plays a pivotal role in lipid metabolism. The small intestine is involved in the digestion, absorption, transport, and synthesis of dietary lipids. The absorption of lipids in the small intestine is a crucial step, as overactive absorption leads to a large amount of lipids entering the bloodstream, which affects the occurrence of obesity. HFD can lead to insulin resistance, disruption of gut microbiota, and inflammatory response in the body, which can further induce lipid absorption and metabolism disorders in the small intestine, thereby promoting the occurrence of chronic metabolic diseases such as obesity. Long term HFD can accelerate pathological structural remodeling and lipid absorption dysfunction of the small intestine: after high-fat diet, the small intestine becomes longer and heavier, with excessive villi elongation and microvilli elongation, thereby increasing the surface area of lipid absorption and causing lipid overload in the small intestine. In addition, overexpression of small intestine uptake transporters, intestinal mucosal damage induced "intestinal leakage", dysbiosis of intestinal microbiota, ultimately leading to abnormal lipid absorption and chronic inflammation, accelerating lipid accumulation and obesity. Exercise, as one of the important means of simple, economical, and effective proactive health interventions, has always been highly regarded for its role in improving lipid metabolism homeostasis. The effect of exercise on small intestine lipid absorption shows a dose-dependent effect. Moderate to low-intensity aerobic exercise can improve the intestinal microenvironment, regulate the structure and lipid absorption function of the small intestine, promote lipid metabolism and health, while vigorous exercise, excessive exercise, and long-term high-intensity training can cause intestinal discomfort, leading to the destruction of intestinal structure and related symptoms, affecting lipid absorption. Long term regular exercise can regulate the diversity of intestinal microbiota, inhibit inflammatory signal transduction such as NF-κB, enhance intestinal mucosal barrier function, and improve intestinal lipid metabolism disorders, further enhancing the process of small intestinal lipid absorption. Exercise also participates in the remodeling process of small intestinal epithelial cells, regulating epithelial structural homeostasis by activating cell proliferation related pathways such as Wnt/β-catenin. Exercise can regulate the expression of lipid transport proteins CD36, FATP, and NPC1L1, and regulate the function of small intestine lipid absorption. However, the research on the effects of long-term exercise on small intestine structure, villus structure, absorption surface area, and lipid absorption related proteins is not systematic enough, the results are inconsistent, and the relevant mechanisms are not clear. In the future, experimental research can be conducted on the dose-response relationship of different intensities and forms of exercise, exploring the mechanisms of exercise improving small intestine lipid absorption and providing theoretical reference for scientific weight loss. It should be noted that the intestine is an organ that is sensitive to exercise response. How to determine the appropriate range, threshold, and form of exercise intensity to ensure beneficial regulation of intestinal lipid metabolism induced by exercise should become an important research direction in the future.

Abstract:Objective Repetitive transcranial magnetic stimulation (rTMS), a non-invasive brain stimulation technique, offers a non-pharmacological therapeutic option for the management of Alzheimer"s disease (AD). Studies have demonstrated that ferroptosis plays a pivotal role in the pathological onset and progression of AD, and the inhibition of neuronal ferroptosis can significantly ameliorate cognitive impairments associated with AD. The imbalance of calcium ion (Ca²⁺) homeostasis is intimately associated with the pathology of AD and serves as a catalyst for the induction of ferroptosis through various pathways. This study is designed to investigate whether rTMS can ameliorate AD by inhibiting neuronal ferroptosis or maintaining calcium homeostasis, ultimately establishing a theoretical and experimental framework for the utilization of rTMS in AD treatment.Methods APP/PS1 AD mice were subjected to both 0.5 Hz low-frequency and 20 Hz high-frequency rTMS treatments, and the efficacy of these treatments was evaluated using novel object recognition and Morris water maze tests. ELISA was employed to quantify the levels of glutathione (GSH), malondialdehyde (MDA), superoxide dismutase (SOD), Fe²⁺ within the hippocampi of mice from each group. HT-22 cells were induced to undergo ferroptosis via Erastin treatment, and subsequent to high- and low-frequency magnetic stimulation, cell viability was assessed using CCK-8 assay, while intracellular calcium ion concentration fluctuations were monitored using Fluo-4 AM.Results The findings revealed that, when compared to normal mice, AD mice displayed a notable decline in cognitive function, accompanied by a substantial increase in ferroptosis levels and intracellular calcium ion concentrations. Both high-frequency and low-frequency applications of rTMS were found to significantly ameliorate cognitive impairments in AD mice, while also effectively mitigating the abnormal augmentation of neuronal ferroptosis and intracellular calcium ion levels.Conclusion The present study underscores that both high-frequency and low-frequency rTMS exhibit efficacy in alleviating cognitive dysfunction in AD mice, potentially through the modulation of ferroptosis and intracellular calcium ion homeostasis.

Abstract:Objective This study aimed to develop a light-weighted classification network for hepatocellular carcinoma (HCC) and non-HCC malignancies based on the automatic analysis of brightness change in contrast-enhanced ultrasound (CEUS).Methods This retrospective study comprised 131 patients diagnosed with HCC and 30 patients with non-HCC malignancies. We used the YOLOX network to detect the tumor region of interest on B-mode ultrasound and CEUS images. A custom-developed algorithm extracted brightness change curves in the tumor and adjacent liver parenchyma regions from CEUS images. We also developed one-dimensional convolutional neural networks (1D-ResNet, 1D-ConvNeXt and 1D-CNN), and machine-learning methods such as support vector machine, ensemble learning, K-nearest neighbor, and decision tree, to analyze brightness change curves and classify HCC and non-HCC malignancies.Results Area under the receiver operating characteristic curve (AUC) of these machine-learning methods were 0.70, 0.56, 0.63, and 0.72 respectively. Meanwhile, the 1D-ResNet, 1D-ConvNeXt and 1D-CNN demonstrated AUCs of 0.72, 0.82 and 0.84 for HCC and non-HCC classification based on brightness change curves.Conclusion The 1D-CNN model can differentiate between patients with HCC and non-HCC malignancies at an accuracy that surpass those of machine learning and other deep learning methods. This paper provides a user-friendly and cost-efficient computer-aided diagnostic solution to aid radiologists in clinical decision-making of HCC.

Abstract:Objective This study aimed to explore the effects of aerobic exercise on cognitive function in aging mice and to elucidate the underlying molecular mechanisms by which aerobic exercise ameliorates cognitive decline through the regulation of gut microbiota-metabolite network. By providing novel insights into the interplay between exercise, gut microbiota, and cognitive health, this research seeks to offer a robust theoretical foundation for developing anti-aging strategies and personalized exercise interventions targeting aging-related cognitive dysfunction.Methods Using naturally aged C57BL/6 mice as the experimental model, this study employed a multi-omics approach combining 16S rRNA sequencing and wide-targeted metabolomics analysis. A total of 18 mice were divided into 3 groups: young control (YC, 4-month-old), old control (OC, 21-month-old), and old+exercise (OE, 21-month-old with 12 weeks of moderate-intensity treadmill training) groups. Behavioral assessments, including the Morris water maze (MWM) test, were conducted to evaluate cognitive function. Histopathological examinations of brain tissue sections provided morphological evidence of neuronal changes. Fecal samples were collected for gut microbiota and metabolite profiling via 16S rRNA sequencing and ultra-performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry (UPLC-QTOF-MS). Data were analyzed using a combination of statistical and bioinformatics tools to identify differentially abundant microbial taxa and metabolites and to construct interaction networks between them.Results Behavioral tests revealed that 12 weeks of aerobic exercise significantly improved spatial learning and memory capacity of aged mice, as evidenced by reduced escape latency and increased target area exploration and platform crossings in the MWM. Histopathological analysis demonstrated that exercise mitigated aging-related neuronal damage in the hippocampus, enhancing neuronal density and morphology. 16S rRNA sequencing indicated that exercise increased gut microbiota α-diversity and enriched beneficial bacterial genera, including Bifidobacterium, Parabacteroides, and Rikenella. Metabolomics analysis identified 32 differentially regulated metabolites between OC and OE groups, with 94 up-regulated and 30 down-regulated in the OE group when compared with OC group. These metabolites were primarily involved in energy metabolism reprogramming (e.g., L-homocitrulline), antioxidant defense (e.g., L-carnosine), neuroprotection (e.g., lithocholic acid), and DNA repair (e.g., ADP-ribose). Network analysis further revealed strong positive correlations between specific bacteria and metabolites, such as Parabacteroides with ADP-ribose and Bifidobacterium with lithocholic acid, suggesting potential neuroprotective pathways mediated by the gut microbiota-metabolite axis.Conclusion This study provides comprehensive evidence that aerobic exercise elicits cognitive benefits in aging mice by modulating the gut microbiota-metabolite network. These findings highlight three key mechanisms: (1) the proliferation of beneficial gut bacteria enhances metabolic reprogramming to boost DNA repair pathways; (2) elevated neuroinflammation-inhibiting factors reduce neurodegenerative changes; and (3) enhanced antioxidant defenses maintain neuronal homeostasis. These results underscore the critical role of the "microbiota-metabolite-brain" axis in mediating the cognitive benefits of aerobic exercise. This study not only advances our understanding of the gut-brain axis in aging but also offers a scientific basis for developing personalized exercise and probiotic-based interventions targeting aging-related cognitive decline. Future research should further validate these mechanisms in non-human primates and human clinical trials to establish the translational potential of exercise-induced gut microbiota-metabolite modulation for combating neurodegenerative diseases.

Abstract:Objective This study aimed to investigate the effects of 4-week high-intensity interval training (HIIT) on synaptic plasticity in the prefrontal cortex (PFC) of rats exposed to chronic unpredictable mild stress (CUMS), and to explore its potential mechanisms.Methods A total of 48 male Sprague-Dawley rats were randomly divided into 4 groups: control (C), model (M), control plus HIIT (HC), and model plus HIIT (HM). Rats in groups M and HM underwent 8 weeks of CUMS to establish depression-like behaviors, while groups HC and HM received HIIT intervention beginning from the 5th week for 4 consecutive weeks. The HIIT protocol consisted of repeated intervals of 3 min at high speed (85%–90% maximal training speed, S_max) alternated with one minute at low speed (50%–55% S_max), with 3 to 5 sets per session, conducted 5 d per week. Behavioral assessments and tail-vein blood lactate levels were measured at the end of the 4th and 8th weeks. After the intervention, rat PFC tissues were collected for Golgi staining to analyze synaptic morphology. Enzyme-linked immunosorbent assays (ELISA) were employed to detect brain-derived neurotrophic factor (BDNF), monocarboxylate transporter 1 (MCT1), lactate, and glutamate levels in the PFC, as well as serotonin (5-HT) levels in serum. Additionally, Western blot analysis was conducted to quantify the expression of synaptic plasticity-related proteins, including c-Fos, activity-regulated cytoskeleton-associated protein (Arc), and N-methyl-D-aspartate receptor 1 (NMDAR1).Results Compared to the control group (C), the CUMS-exposed rats (group M) exhibited significant reductions in sucrose preference rates, number of grid crossings, frequency of upright postures, and entries into and duration spent in open arms of the elevated plus maze, indicating marked depressive-like behaviors. Additionally, the group M showed significantly reduced dendritic spine density in the PFC, along with elevated levels of c-Fos, Arc, NMDAR1 protein expression, and increased concentrations of lactate and glutamate. Conversely, BDNF and MCT1 contents in the PFC and 5-HT levels in serum were significantly decreased. Following HIIT intervention, rats in the group HM displayed considerable improvement in behavioral indicators compared with the group M, accompanied by significant elevations in PFC MCT1 and lactate concentrations. Furthermore, HIIT notably normalized the expression levels of c-Fos, Arc, NMDAR1, as well as glutamate and BDNF contents in the PFC. Synaptic spine density also exhibited significant recovery.Conclusion 4 weeks of HIIT intervention may alleviate depressive-like behaviors in CUMS rats by increasing lactate levels and reducing glutamate concentration in the prefrontal cortex (PFC), thereby downregulating the overexpression of NMDAR, attenuating excitotoxicity, and enhancing synaptic plasticity.

Abstract:Exercise fatigue is a complex physiological and psychological phenomenon that includes peripheral fatigue in the muscles and central fatigue in the brain. Peripheral fatigue refers to the loss of force caused at the distal end of the neuromuscular junction, whereas central fatigue involves decreased motor output from the primary motor cortex, which is associated with modulations at anatomical sites proximal to nerves that innervate skeletal muscle. The central regulatory failure reflects a progressive decline in the central nervous system"s capacity to recruit motor units during sustained physical activity. Emerging evidence highlights the critical involvement of central neurochemical regulation in fatigue development, particularly through neurotransmitter-mediated modulation. Alterations in neurotransmitter release and receptor activity could influence excitatory and inhibitory signal pathways, thus modulating the perception of fatigue and exercise performance. Increased serotonin (5-HT) could increase perception of effort and lethargy, reduce motor drive to continue exercising, and contribute to exercise fatigue. Decreased dopamine (DA) and noradrenaline (NE) neurotransmission can negatively impact arousal, mood, motivation, and reward mechanisms and impair exercise performance. Furthermore, the serotonergic and dopaminergic systems interact with each other; a low 5-HT/DA ratio enhances motor motivation and improves performance, and a high 5-HT/DA ratio heightens fatigue perception and leads to decreased performance. The expression and activity of neurotransmitter receptors would be changed during prolonged exercise to fatigue, affecting the transmission of nerve signals. Prolonged high-intensity exercise causes excess 5-HT to overflow from the synaptic cleft to the axonal initial segment and activates the 5-HT1A receptor, thereby inhibiting the action potential of motor neurons and affecting the recruitment of motor units. During exercise to fatigue, the DA secretion is decreased, which blocks the binding of DA to D1 receptor in the caudate putamen and inhibits the activation of the direct pathway of the basal ganglia to suppress movement, meanwhile the binding of DA to D2 receptor is restrained in the caudate putamen, which activates the indirect pathway of the basal ganglia to influence motivation. Furthermore, other neurotransmitters and their receptors, such as adenosine (ADO), glutamic acid (Glu), and γ-aminobutyric acid (GABA) also play important roles in regulating neurotransmitter balance and fatigue. The occurrence of central fatigue is not the result of the action of a single neurotransmitter system, but a comprehensive manifestation of the interaction between multiple neurotransmitters. This review explores the important role of neurotransmitters and their receptors in central motor fatigue, reveals the dynamic changes of different neurotransmitters such as 5-HT, DA, NE, and ADO during exercise, and summarizes the mechanisms by which these neurotransmitters and their receptors regulate fatigue perception and exercise performance through complex interactions. Besides, this study presents pharmacological evidence that drugs such as agonists, antagonists, and reuptake inhibitors could affect exercise performance by regulating the metabolic changes of neurotransmitters. Recently, emerging interventions such as dietary bioactive components intake and transcranial electrical stimulation may provide new ideas and strategies for the prevention and alleviation of exercise fatigue by regulating neurotransmitter levels and receptor activity. Overall, this work offers new theoretical insights into the understanding of exercise central fatigue, and future research should further investigate the relationship between neurotransmitters and their receptors and exercise fatigue.

Abstract:Age-related sarcopenia is a progressive, systemic skeletal muscle disorder associated with aging. It is primarily characterized by a significant decline in muscle mass, strength, and physical function, rather than being an inevitable consequence of normal aging. Despite ongoing research, there is still no globally unified consensus among physicians regarding the diagnostic criteria and clinical indicators of this condition. Nonetheless, regardless of the diagnostic standards applied, the prevalence of age-related sarcopenia remains alarmingly high. With the global population aging at an accelerating rate, its incidence is expected to rise further, posing a significant public health challenge. Age-related sarcopenia not only markedly increases the risk of physical disability but also profoundly affects patients’ quality of life, independence, and overall survival. As such, the development of effective prevention and treatment strategies to mitigate its dual burden on both societal and individual health has become an urgent and critical priority. Skeletal muscle regeneration, a vital physiological process for maintaining muscle health, is significantly impaired in age-related sarcopenia and is considered one of its primary underlying causes. Skeletal muscle satellite cells (MSCs), also known as muscle stem cells, play a pivotal role in generating new muscle fibers and maintaining muscle mass and function. A decline in both the number and functionality of MSCs is closely linked to the onset and progression of sarcopenia. This dysfunction is driven by alterations in intrinsic MSC mechanisms—such as Notch, Wnt/β-Catenin, and mTOR signaling pathways—as well as changes in transcription factors and epigenetic modifications. Additionally, the MSC microenvironment, including both the direct niche formed by skeletal muscle fibers and their secreted cytokines, and the indirect niche composed of extracellular matrix proteins and various cell types, undergoes age-related changes. Mitochondrial dysfunction and chronic inflammation further contribute to MSC impairment, ultimately leading to the development of sarcopenia. Currently, there are no approved pharmacological treatments for age-related sarcopenia. Nutritional intervention and exercise remain the cornerstone of therapeutic strategies. Adequate protein intake, coupled with sufficient energy provision, is fundamental to both the prevention and treatment of this condition. Adjuvant therapies, such as dietary supplements and caloric restriction, offer additional therapeutic potential. Exercise promotes muscle regeneration and ameliorates sarcopenia by acting on MSCs through various mechanisms, including mechanical stress, myokine secretion, distant cytokine signaling, immune modulation, and epigenetic regulation. When combined with a structured exercise regimen, adequate protein intake has been shown to be particularly effective in preventing age-related sarcopenia. However, traditional interventions may be inadequate for patients with limited mobility, poor overall health, or advanced sarcopenia. Emerging therapeutic strategies—such as miRNA mimics or inhibitors, gut microbiota transplantation, and stem cell therapy—present promising new directions for MSC-based interventions. This review comprehensively examines recent advances in MSC-mediated muscle regeneration in age-related sarcopenia and systematically discusses therapeutic strategies targeting MSC regulation to enhance muscle mass and strength. The goal is to provide a theoretical foundation and identify future research directions for the prevention and treatment of this increasingly prevalent condition.

Abstract:Modified electro-convulsive therapy (MECT) is one of the most potent treatments for major depressive disorder (MDD). However, it remains a second-line option due to significant side effects, such as transient memory loss. The relationship between therapeutic efficacy and cognitive impairment warrants further investigation to develop improved treatment regimens. In this review, we examine recent evidence from magnetic resonance imaging (MRI) studies aiming to identify structural and functional brain changes specifically associated with both the antidepressant effects and the amnesic outcomes of MECT. MECT induces widespread alterations across multiple brain systems. Increases in gray matter volume (GMV) have been observed in the prefrontal, temporal, and parietal cortices, as well as in subcortical regions such as the hippocampus (HP), amygdala, and striatum. Strengthening of myelination has also been reported along the dorsolateral prefrontal-limbic pathways. Functional changes include increased spontaneous neural activity in prefrontal areas, reorganization of intrinsic connectivity within the default mode network (DMN), and altered functional connectivity (FC) among the DMN, salience network (SN), and central executive network (CEN). Correlational studies have identified structural and functional alterations linked to antidepressant efficacy, including right hippocampal volume enlargement, prefrontal cortical thickening, reduced iron deposition in the striatum, decreased FC within certain DMN nodes, and enhanced effective connectivity from the dorsolateral prefrontal cortex (DLPFC) to the right angular gyrus. In contrast, the amnesic effects have been associated with increased volumes in the left hippocampus and bilateral dentate gyrus; enhanced FC in the left angular gyrus and left posterior cingulate cortex (PCC); increased FC between the right ventral anterior insula and DLPFC; and reduced FC in the left thalamus and bilateral precuneus. Changes in the hippocampus appear to correlate with both antidepressant efficacy and memory impairment. Clinical studies have found no significant correlation between the severity of memory impairment and the reduction in depressive symptoms, suggesting that the therapeutic and adverse effects may arise from distinct regional or subregional mechanisms. Supporting this hypothesis, recent findings show that increased right hippocampal volume is significantly associated with reduced depression scores, whereas increased volume in the left dentate gyrus correlates with declines in delayed recall performance. Additionally, enhanced connectivity between the anterior hippocampus and middle occipital gyrus (MOG) has been linked to mood improvement, while decreased FC between the mid-hippocampus and angular gyrus has been associated with impairments in memory integration. In conclusion, current evidence suggests that the antidepressant and memory-impairing effects of MECT may localize to distinct hippocampal subregions. These effects likely result from differential modulation of local neural activity and functional connectivity, leading to divergent behavioral outcomes. Given that both effects may originate in deep and spatially constrained structures such as the hippocampus, small-sample studies and conventional methodologies may fail to differentiate them effectively. Future research should employ large-scale, longitudinal designs utilizing high-field MRI and multimodal neuroimaging to characterize MECT-induced structure-function coupling in the hippocampus and its integration at the network level. Additionally, multiscale analyses spanning molecular, circuit, and network dimensions would be beneficial.

Abstract:Objective This paper proposes a novel real-time bedside pulmonary ventilation monitoring method for the diagnosis of chronic obstructive pulmonary disease (COPD), based on electrical impedance tomography (EIT). Four indicators—Center of Ventilation (CoV), Global Inhomogeneity Index (GI), Regional Ventilation Delay Inhomogeneity (RVDI), and the ratio of forced expiratory volume in one second to forced vital capacity (FEV1/FVC)—are calculated to enable the spatiotemporal assessment of COPD.Methods A simulation of the respiratory cycles of COPD patients was first conducted, revealing significant differences in certain indicators compared to healthy individuals. The effectiveness of these indicators was then validated through experiments. A total of 93 subjects underwent multiple pulmonary function tests (PFTs) alongside simultaneous EIT measurements. Ventilation heterogeneity under different breathing patterns—including forced exhalation, forced inhalation, and quiet tidal breathing—was compared. EIT images and related indicators were analyzed to distinguish healthy individuals across different age groups from COPD patients.Results Simulation results demonstrated significant differences in CoV, GI, FEV1/FVC, and RVDI between COPD patients and healthy individuals. Experimental findings indicated that, in terms of spatial heterogeneity, the GI values of COPD patients were significantly higher than those of the other two groups, while no significant differences were observed among healthy individuals. Regarding temporal heterogeneity, COPD patients exhibited significantly higher RVDI values than the other groups during both quiet breathing and forced inhalation. Moreover, during forced exhalation, the distribution of FEV1/FVC values further highlighted the temporal delay heterogeneity of regional lung function in COPD patients, distinguishing them from healthy individuals of various ages.Conclusion EIT technology effectively reveals the spatiotemporal heterogeneity of regional lung function, which holds great promise for the diagnosis and management of COPD.

Abstract:Objective This study investigates the regulatory role of pescadillo ribosomal biogenesis factor 1 (PES1) in cellular senescence and elucidates its underlying molecular mechanisms.Methods Using replicative senescence models of mouse embryonic fibroblasts (MEFs) and doxorubicin-induced senescence in human hepatocellular carcinoma HepG2 cells, we first quantified PES1 expression dynamics through immunoblotting. Subsequently, siRNA-mediated PES1 knockdown in HepG2 or other cells was employed to assess senescence phenotypes via β-galactosidase staining and immunodetection of senescence-associated markers. Mechanistic exploration involved Northern blot for pre-rRNA processing analysis and fluorescence microscopy for nucleolar morphology observation.Results PES1 expression was significantly downregulated in both replicatively senescent MEFs and doxorubicin-induced senescent HepG2 cells. siRNA-mediated PES1 depletion triggered premature senescence characterized by increased SA-β-gal positivity and upregulated p53/p21 signaling, while Rb pathway components remained unaltered. Notably, PES1 deficiency impaired 28S rRNA biogenesis and induced nucleolar fragmentation, indicative of nucleolar stress.Conclusion Inhibition of PES1 expression can induce nucleolar stress and activate p53-dependent rather than Rb-dependent senescence signals within cells.