ObjectiveTo investigate the regulatory effect of overexpressed protein tyrosine phosphatase non-receptor type 2 （Ptpn2） on the inflammatory response of mouse alveolar macrophages （MH-S） induced by SiO₂. MethodsCells with overexpressed Ptpn2 were constructed and induced by SiO₂. The experimental groups were divided into four groups： the negative control group with an empty vector （NC）， the overexpressed Ptpn2 group （P）， the negative control group with an empty vector + SiO₂ induction （NS）， and the overexpressed Ptpn2 + SiO₂ induction group （PS）. Isobaric tags for relative and absolute quantification （iTRAQ） combined with liquid chromatography-tandem mass spectrometry （LC-MS/MS） were used to screen differential proteins， followed by Gene Ontology （GO） and Kyoto Encyclopedia of Genes and Genomes （KEGG） database analyses. Immunofluorescence staining was used to detect the expressions of Tumor necrosis factor （TNF） α， Gasdermin D （GSDMD）， and Transforming growth factor （TGF）-β1. Western blot was used to detect the protein expression levels of PTPN2， Toll-like receptor 4 （TLR4）， tumor necrosis factor-α （TNF-α）， nucleotide-binding oligomerization domain-like receptor protein 3 （NLRP3）， and proteins related to the TGF-β1 signaling pathway in the cells of each group. ResultsiTRAQ results identified 144 differential proteins among the four groups. GO analysis showed that in biological processes （BP）， these differential proteins were mainly enriched in IκB kinase/nuclear factor-κB （NF-κB） signaling， cell activation and signal transduction involved in immune responses， and regulation of receptor signaling pathways by signal transducer and activator of transcription （STAT）， etc. KEGG analysis revealed that the differential proteins were mainly enriched in Toll-like receptor signaling pathway， NF-κB signaling pathway， NOD-like receptor signaling pathway， TGF-β signaling pathway， and TNF signaling pathway. The results of immunofluorescence staining showed that compared with the NC group， the expressions of TNF α， GSDMD， and TGF-β1 in the cells of the NS group increased （P < 0.05）； compared to the NS group， the expression of the aforementioned proteins in the PS group decreased in cellular proteins（P < 0.05）. The results of Western blot showed that compared with the NC group， the protein expression levels of PTPN2， p-NF-κB，MyD88，TLR4，NLRP3，GSDMD，Caspase-1，IL-1β， TGF-βR1， TGF-βR，p-Smad2/3 in the NS group were significantly upregulated （P < 0.05）； compared with the NS group， the expression levels of the aforementioned proteins in the PS group were significantly downregulated （P < 0.05）. ConclusionOverexpression of Ptpn2 can inhibit the protein expressions of TLR4-TNF-α signaling， NLRP3 signaling， and TGF-β1 signaling closely related to inflammatory response in SiO₂-mediated MH-S macrophages.

ObjectiveTo investigate the mechanism by which the Zishen Huoxue prescription （ZSHXP） ameliorates cognitive dysfunction in rats with vascular dementia （VD） induced by the bilateral common carotid artery ligation （2-VO model rats） through regulating the glucose-regulated protein 78 （GRP78）/protein kinase R-like endoplasmic reticulum kinase （PERK）/activating transcription factor 4 （ATF4） signaling pathway. MethodsA VD rat model was established via the 2-VO method. A total of 72 male Sprague-Dawley （SD） rats were randomly divided into six groups： Sham group， Model group， donepezil hydrochloride group （0.45 mg·kg^-1）， and ZSHXP groups at low （8.90 g·kg^-1）， medium （17.80 g·kg^-1）， and high （35.60 g·kg^-1） doses，with 12 rats in each group. The Morris Water Maze test was utilized to assess spatial learning and memory abilities of rats， and the Novel Object Recognition test was used to evaluate cognitive performance. Hematoxylin-eosin （HE） and Nissl staining were applied to observe the histological and morphological changes in hippocampal tissues. Transmission electron microscopy （TEM） was used to observe the morphological changes of endoplasmic reticulum in rat hippocampal neurons. Immunofluorescence staining was adopted to detect the colocalization of neuronal nuclei antigen （NeuN） with GRP78 and βⅢ Tubulin with gasdermin D （GSDMD） in hippocampal neurons. Western blot was used to detect the expression levels of endoplasmic reticulum stress （ERS）-related proteins including GRP78， PERK， ATF4， phosphorylated protein kinase R-like endoplasmic reticulum kinase （p-PERK）， C/EBP homologous protein （CHOP）， NOD-like receptor protein 3 （NLRP3）， Caspase-1 and GSDMD. ResultsCompared with the sham operation group， the model group showed a significantly prolonged escape latency （P<0.01）， a significant decrease in the number of platform crossings and the residence time in the target quadrant （P<0.01）， and a markedly reduced recognition index （P<0.01）. Histological observations revealed that the hippocampal neurons in the model group were disorderly arranged with reduced quantity， deformed and shrunken cell bodies， and pyknotic and hyperchromatic nuclei. The number of Nissl bodies decreased significantly. The number of endoplasmic reticula reduced obviously， accompanied by abnormal dilation and swelling， and the loss of normal folding structure. The fluorescence colocalization of NeuN with GRP78 and βⅢ Tubulin with GSDMD in the hippocampus was significantly increased in the model group. The protein expression levels of GRP78， p-PERK/PERK， ATF4， CHOP， NLRP3， GSDMD and Caspase-1 in the model group were significantly elevated （P<0.01）. Compared with the model group， the donepezil hydrochloride group and the ZSHXP medium- and high-dose groups had a significantly shortened escape latency （P<0.01） and an increased number of platform crossings （P<0.05， P<0.01）. The residence time in the target quadrant was increased in the donepezil hydrochloride group and all ZSHXP groups （P<0.05， P<0.01）， with a significantly improved recognition index （P<0.01）. In the donepezil hydrochloride group and all ZSHXP groups， the number of hippocampal neurons increased with a more compact arrangement and reduced nuclear hyperchromasia. The number of Nissl bodies increased with morphological structures tending to be normal. In the ZSHXP high-dose group， the number of endoplasmic reticula increased and the folding structure was restored. The fluorescence colocalization of NeuN with GRP78 and βⅢ Tubulin with GSDMD in the hippocampus was significantly weakened in the treatment groups. In the donepezil hydrochloride group， the protein expressions of GRP78， ATF4 and CHOP were increased （P<0.01）， while the expression of p-PERK/PERK was decreased （P<0.05）. In the ZSHXP low-dose group， the expressions of GRP78， p-PERK/PERK and CHOP were elevated （P<0.05， P<0.01）. The ZSHXP medium- and high-dose groups showed a significant decrease in the protein expressions of p-PERK/PERK， ATF4 and CHOP （P<0.01）， and the high-dose group had a markedly reduced GRP78 protein expression （P<0.01）. In the donepezil hydrochloride group， the Caspase-1 protein expression was increased （P<0.01） and the NLRP3 protein expression was decreased （P<0.01）. In the ZSHXP low-dose group， the GSDMD expression was elevated （P<0.01） while the NLRP3 protein expression was reduced （P<0.01）. After treatment with medium and high doses of ZSHXP， the protein expression levels of NLRP3， GSDMD and Caspase-1 were significantly decreased （P<0.01）. ConclusionThe ameliorative effect of ZSHXP on cognitive function in 2-VO model rats may be associated with its regulation of the GRP78/PERK/ATF4 signaling pathway， which ameliorates ERS and inhibits neuronal pyroptosis.

Diabetic retinopathy(DR)remains the leading cause of vision loss in patients with diabetes. Current anti-vascular endothelial growth factor(VEGF)therapies are limited by inadequate response in some patients and the necessity for repeated intravitreal injections, underscoring the urgent need for novel therapeutic targets. Angiopoietin-like protein 4(ANGPTL4), a multifunctional secreted protein, has emerged as a critical regulator in the pathogenesis and progression of DR, positioning it as a promising interventional target. This review systematically elaborates the biological characteristics of ANGPTL4, with a focus on its expression dynamics, molecular mechanisms, and regulatory networks rolesin the development of DR. Furthermore, the prospects of ANGPTL4-targeted therapeutic strategies are discussed, aiming to offer new insights and directions for understanding DR pathogenesis, advancing multi-target drug development, and improving clinical management.

ObjectiveTo investigate the mechanism by which the Zishen Huoxue prescription （ZSHXP） ameliorates cognitive dysfunction in rats with vascular dementia （VD） induced by the bilateral common carotid artery ligation （2-VO model rats） through regulating the glucose-regulated protein 78 （GRP78）/protein kinase R-like endoplasmic reticulum kinase （PERK）/activating transcription factor 4 （ATF4） signaling pathway. MethodsA VD rat model was established via the 2-VO method. A total of 72 male Sprague-Dawley （SD） rats were randomly divided into six groups： Sham group， Model group， donepezil hydrochloride group （0.45 mg·kg^-1）， and ZSHXP groups at low （8.90 g·kg^-1）， medium （17.80 g·kg^-1）， and high （35.60 g·kg^-1） doses，with 12 rats in each group. The Morris Water Maze test was utilized to assess spatial learning and memory abilities of rats， and the Novel Object Recognition test was used to evaluate cognitive performance. Hematoxylin-eosin （HE） and Nissl staining were applied to observe the histological and morphological changes in hippocampal tissues. Transmission electron microscopy （TEM） was used to observe the morphological changes of endoplasmic reticulum in rat hippocampal neurons. Immunofluorescence staining was adopted to detect the colocalization of neuronal nuclei antigen （NeuN） with GRP78 and βⅢ Tubulin with gasdermin D （GSDMD） in hippocampal neurons. Western blot was used to detect the expression levels of endoplasmic reticulum stress （ERS）-related proteins including GRP78， PERK， ATF4， phosphorylated protein kinase R-like endoplasmic reticulum kinase （p-PERK）， C/EBP homologous protein （CHOP）， NOD-like receptor protein 3 （NLRP3）， Caspase-1 and GSDMD. ResultsCompared with the sham operation group， the model group showed a significantly prolonged escape latency （P<0.01）， a significant decrease in the number of platform crossings and the residence time in the target quadrant （P<0.01）， and a markedly reduced recognition index （P<0.01）. Histological observations revealed that the hippocampal neurons in the model group were disorderly arranged with reduced quantity， deformed and shrunken cell bodies， and pyknotic and hyperchromatic nuclei. The number of Nissl bodies decreased significantly. The number of endoplasmic reticula reduced obviously， accompanied by abnormal dilation and swelling， and the loss of normal folding structure. The fluorescence colocalization of NeuN with GRP78 and βⅢ Tubulin with GSDMD in the hippocampus was significantly increased in the model group. The protein expression levels of GRP78， p-PERK/PERK， ATF4， CHOP， NLRP3， GSDMD and Caspase-1 in the model group were significantly elevated （P<0.01）. Compared with the model group， the donepezil hydrochloride group and the ZSHXP medium- and high-dose groups had a significantly shortened escape latency （P<0.01） and an increased number of platform crossings （P<0.05， P<0.01）. The residence time in the target quadrant was increased in the donepezil hydrochloride group and all ZSHXP groups （P<0.05， P<0.01）， with a significantly improved recognition index （P<0.01）. In the donepezil hydrochloride group and all ZSHXP groups， the number of hippocampal neurons increased with a more compact arrangement and reduced nuclear hyperchromasia. The number of Nissl bodies increased with morphological structures tending to be normal. In the ZSHXP high-dose group， the number of endoplasmic reticula increased and the folding structure was restored. The fluorescence colocalization of NeuN with GRP78 and βⅢ Tubulin with GSDMD in the hippocampus was significantly weakened in the treatment groups. In the donepezil hydrochloride group， the protein expressions of GRP78， ATF4 and CHOP were increased （P<0.01）， while the expression of p-PERK/PERK was decreased （P<0.05）. In the ZSHXP low-dose group， the expressions of GRP78， p-PERK/PERK and CHOP were elevated （P<0.05， P<0.01）. The ZSHXP medium- and high-dose groups showed a significant decrease in the protein expressions of p-PERK/PERK， ATF4 and CHOP （P<0.01）， and the high-dose group had a markedly reduced GRP78 protein expression （P<0.01）. In the donepezil hydrochloride group， the Caspase-1 protein expression was increased （P<0.01） and the NLRP3 protein expression was decreased （P<0.01）. In the ZSHXP low-dose group， the GSDMD expression was elevated （P<0.01） while the NLRP3 protein expression was reduced （P<0.01）. After treatment with medium and high doses of ZSHXP， the protein expression levels of NLRP3， GSDMD and Caspase-1 were significantly decreased （P<0.01）. ConclusionThe ameliorative effect of ZSHXP on cognitive function in 2-VO model rats may be associated with its regulation of the GRP78/PERK/ATF4 signaling pathway， which ameliorates ERS and inhibits neuronal pyroptosis.

Lactylation (Kla), a protein post-translational modification characterized by the covalent conjugation of lactyl groups to lysine residues in proteins, is widely present in living organisms. Since its discovery in 2019, it has attracted much attention for its role in regulating major pathological processes such as tumorigenesis, neurodegenerative diseases, and cardiovascular diseases. By mediating core biological processes such as signal transduction, epigenetic regulation, and metabolic homeostasis, lactylation contributes to disease progression. However, the lactylation donor lactyl-CoA has a low intracellular concentration, and the specific enzyme catalyzing lactylation is not yet clear, which has become an urgent issue in lactate research. A groundbreaking study in 2024 found that alanyl-transfer t-RNA synthetase 1/2 (AARS1/2), members of the aminoacyl-tRNA synthetase (aaRS) family, can act as protein lysine lactate transferases, modifying histones and metabolic enzymes directly with lactate as a substrate, without relying on the classical substrate lactyl-CoA, promoting a new stage in lactate research. Although exercise significantly increases lactate levels in the body and can induce changes in lactylation in multiple tissues and cells, the regulation of lactylation by exercise is not entirely consistent with lactate levels. Research has found that high-intensity exercise can induce upregulation of lactate at 37 lysine sites in 25 proteins of adipose tissue, while leading to downregulation of lactate at 27 lysine sites in 22 proteins. The level of lactate is not the only factor regulating lactylation through exercise. We speculate that the lactate transferase AARS1/2 play an important role in the process of lactylation regulated by exercise, and AARS1/2 should also be regulated by exercise. This review introduces the molecular biology characteristics, subcellular localization, and multifaceted biological functions of AARS, including its canonical roles in alanylation and editing, as well as its newly identified lactate transferase activity. We detail the discovery of AARS1/2 as lactylation catalysts and the specific process of them as lactate transferases catalyzing protein lactylation. Furthermore, we discuss the pathophysiological significance of AARS in tumorigenesis, immune dysregulation, and neuropathy, with a focus on exploring the expression regulation and possible mechanisms of AARS through exercise. The expression of AARS in skeletal muscle regulated by exercise is related to exercise time and muscle fiber type; the skeletal muscle AARS2 upregulated by long-term and high-intensity exercise catalyzes the lactylation of key metabolic enzymes such as pyruvate dehydrogenase E1 alpha subunit (PDHA1) and carnitine palmitoyltransferase 2 (CPT2), reducing exercise capacity and providing exercise protection; physiological hypoxia caused by exercise significantly reduces the ubiquitination degradation of AARS2 by inhibiting its hydroxylation, thereby maintaining high levels of AARS2 protein and exerting lactate transferase function; exercise induced lactate production can promote the translocation of AARS1 cytoplasm to the nucleus, exert lactate transferase function upon nuclear entry, regulate histone lactylation, and participate in gene expression regulation; exercise induced lactate production promotes direct interactions between AARS and star molecules such as p53 and cGAS, and is widely involved in the occurrence and development of tumors and immune diseases. Elucidating the regulatory mechanism of exercise on AARS can provide new ideas for improving metabolic diseases and promote health through exercise.

The pathogenesis of cardiovascular diseases (CVD) is complex, and dynamic imbalances in protein acylation modification are significantly associated with the development of CVD. In recent years, most studies on exercise-regulated protein acylation modifications to improve cardiovascular function have focused on acetylation and lactylation. Protein acylation modifications are usually affected by exercise intensity. High-intensity exercise directly affects oxidative stress and cellular energy supply, such as changes in ATP and NAD⁺ levels; moderate-intensity exercise is often accompanied by improvements in aerobic metabolism, such as fatty acid β-oxidation and TCA cycle, which modulate mitochondrial biogenesis. The above processes may affect the acylation status of relevant regulatory enzymes and functional proteins, thereby altering their function and activity and triggering signaling cascades to adapt to exercise’s metabolic demands and stresses. Exercise regulates the levels of acylation modifications of H3K9, H3K14, H3K18, and H3K23, which are involved in regulating the transcriptional expression of genes involved in oxidative stress, glycolysis, inflammation, and hypertrophic response by altering chromatin structure and function. Exercise can regulate the acylation modification of non-histone-specific sites in the cardiovascular system involved in mitochondrial function, glycolipid metabolism, fibrosis, protein synthesis, and other biological processes, and participates in the regulation of protein activity and function by altering the stability, localization, and interaction of proteins, and ultimately works together to achieve the improvement of cardiovascular phenotypes and biological functions. Exercise affects acyl donor concentration, acyltransferase, and deacetylase expression and activity by influencing acyl donor concentration, acyltransferase, and deacetylase. Exercise regulates the abundance of acyl donors such as acetyl coenzyme A, propionyl coenzyme A, butyryl coenzyme A, succinyl coenzyme A, and lactoyl coenzyme A by promoting glucose and lipid metabolism and improving intestinal bacterial flora, which in turn affects protein acylation modification, accelerates oxidative decarboxylation of pyruvic acid in the body, and activates the energy-sensing molecule, adenosine monophosphate-activated protein kinase (AMPK), to improve cardiovascular function. Exercise may affect protein acylation modifications in the cardiovascular system by regulating the activity and expression of adenoviral E1A binding protein of 300 kDa (p300)/cyclic adenosine monophosphate response element-binding protein (CBP), general control nonderepressible 5-related N-acetyltransferases (GNAT), and alanyl-transfer t-RNA synthetase (AARS), which in turn improves cardiovascular function. The relationship between exercise and cardiovascular deacetylases has attracted much attention, with SIRT1 and SIRT3 of the silence information regulator (SIRT) family of proteins being the most studied. Exercise may exert transient or long-term stable cardiovascular protective benefits by promoting the enzymatic activity and expression of SIRT1, SIRT3, and HDAC2, inhibiting the enzymatic activity and expression of HDAC4, and mediating the deacylation of metabolic regulation-related enzymes, cytokines, and molecules of signaling pathways. This review introduces the role of protein acylation modification on CVD and the effect of exercise-mediated protein acylation modification on CVD. Based on the existing studies, it analyzes the possible mechanisms of exercise-regulated protein acylation modification to improve CVD from the perspectives of acylation modification donors, acyltransferases, and deacetylases. Deciphering the regulation of cardiovascular protein acylation and modification by exercise and exploring the essential clues to improve cardiovascular disease can enrich the theoretical basis for exercise to promote cardiovascular health. However, it is also significant for developing new cardiovascular disease prevention and treatment targets.

This paper aimed to systematically evaluate the effects of hypoxic training at different fraction of inspired oxygen (FiO₂) on body composition, glucose metabolism, and lipid metabolism in obese individuals, and to determine the optimal oxygen concentration range to provide scientific evidence for personalized and precise hypoxic exercise prescriptions. A systematic search was conducted in the Cochrane Library, PubMed, Web of Science, Embase, and CNKI databases for randomized controlled trials and pre-post intervention studies published up to March 31, 2025, involving hypoxic training interventions in obese populations. Meta-analysis was performed using RevMan 5.4 software to assess the effects of different fraction of inspired oxygen (FiO₂≤14% vs. FiO₂>14%) on BMI, body fat percentage, waist circumference, fasting blood glucose, insulin, HOMA-IR, triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C), with subgroup analyses based on oxygen concentration. A total of 22 studies involving 292 participants were included. Meta-analysis showed that hypoxic training significantly reduced BMI (mean difference (MD)=-2.29,95%CI: -3.42 to -1.17, P<0.000 1), body fat percentage (MD=-2.32, 95%CI: -3.16 to -1.47, P<0.001), waist circumference (MD=-3.79, 95%CI: -6.73 to -0.85, P=0.01), fasting blood glucose (MD=-3.58, 95%CI: -6.23 to -0.93, P=0.008), insulin (MD=-1.60, 95%CI: -2.98 to -0.22, P=0.02), TG (MD=-0.18, 95%CI: -0.25 to -0.12, P<0.001), and LDL-C (MD=-0.25, 95%CI: -0.39 to -0.11, P=0.000 3). Greater improvements were observed under moderate hypoxic conditions with FiO₂>14%. Changes in HOMA-IR (MD=-0.74, 95%CI: -1.52 to 0.04,P=0.06) and HDL-C (MD=-0.09, 95%CI: -0.21 to 0.02, P=0.11) were not statistically significant. Hypoxic training can significantly improve body composition, glucose metabolism, and lipid metabolism indicators in obese individuals, with greater benefits observed under moderate hypoxia (FiO>14%). As a key parameter in hypoxic exercise interventions, the precise setting of oxygen concentration is crucial for optimizing intervention outcomes.

Thrombospondin 4 (THBS4; TSP4), a crucial component of the extracellular matrix (ECM), serves as an important regulator of tissue homeostasis and various pathophysiological processes. As a member of the evolutionarily conserved thrombospondin family, THBS4 is a multidomain adhesive glycoprotein characterized by six distinct structural domains that mediate its diverse biological functions. Through dynamic interactions with various ECM components, THBS4 plays pivotal roles in cell adhesion, proliferation, inflammation regulation, and tissue remodeling, establishing it as a key modulator of microenvironmental organization. The transcription and translation of THBS4 gene, as well as the activity of the THBS4 protein, are tightly regulated by multiple signaling pathways and extracellular cues. Positive regulators of THBS4 include transforming growth factor-β (TGF-β), interferon-γ (IFNγ), granulocyte-macrophage colony-stimulating factor (GM-CSF), bone morphogenetic proteins (BMP12/13), and other regulatory factors (such as B4GALNT1, ITGA2/ITGB1, PDGFRβ, etc.), which upregulate THBS4 at the mRNA and/or protein level. Conversely, oxidized low-density lipoprotein (OXLDL) acts as a potent negative regulator of THBS4. This intricate regulatory network ensures precise spatial and temporal control of THBS4 expression in response to diverse physiological and pathological stimuli. Functionally, THBS4 acts as a critical signaling hub, influencing multiple downstream pathways essential for cellular behavior and tissue homeostasis. The best-characterized pathways include: (1) the PI3K/AKT/mTOR axis, which THBS4 modulates through both direct and indirect interactions with integrins and growth factor receptors; (2) Wnt/β-catenin signaling, where THBS4 functions as either an activator or inhibitor depending on the cellular context; (3) the suppression of DBET/TRIM69, contributing to its diverse regulatory roles. These signaling connections position THBS4 as a master regulator of cellular responses to microenvironmental changes. Substantial evidence links aberrant THBS4 expression to a range of pathological conditions, including neoplastic diseases, cardiovascular disorders, fibrotic conditions, neurodegenerative diseases, musculoskeletal disorders, and atopic dermatitis. In cancer biology, THBS4 exhibits context-dependent roles, functioning either as a tumor suppressor or promoter depending on the tumor type and microenvironment. In the cardiovascular system, THBS4 contributes to both adaptive remodeling and maladaptive fibrotic responses. Its involvement in fibrotic diseases arises from its ability to regulate ECM deposition and turnover. The diagnostic and therapeutic potential of THBS4 is particularly promising in oncology and cardiovascular medicine. As a biomarker, THBS4 expression patterns correlate significantly with disease progression and patient outcomes. Therapeutically, targeting THBS4-mediated pathways offers novel opportunities for precision medicine approaches, including anti-fibrotic therapies, modulation of the tumor microenvironment, and enhancement of tissue repair. This comprehensive review systematically explores three key aspects of THBS4 research(1) the fundamental biological functions of THBS4 in ECM organization; (2) its mechanistic involvement in various disease pathologies; (3) its emerging potential as both a diagnostic biomarker and therapeutic target. By integrating recent insights from molecular studies, animal models, and clinical investigations, this review provides a framework for understanding the multifaceted roles of THBS4 in health and disease. The synthesis of current knowledge highlights critical research gaps and future directions for exploring THBS4-targeted interventions across multiple disease contexts. Given its unique position at the intersection of ECM biology and cellular signaling, THBS4 represents a promising frontier for the development of novel diagnostic tools and therapeutic strategies in precision medicine.

ObjectiveAs the central hub of the classical visual pathway, the primary visual cortex not only encodes and processes visual information but also establishes dense neural circuit connections with higher-order cognitive brain regions. Numerous studies have shown that 40 Hz flicker stimulation can induce γ oscillations in the brain and significantly improve learning and cognitive impairments in patients with neurodegenerative diseases. Moreover, flickering light phenomena naturally occur in daily environments. Given that the primary visual cortex serves as the brain’s first cortical hub for receiving visual input, it is essential to comprehensively understand how non-invasive light flicker stimulation modulates its information processing mechanisms. This study systematically investigates the effects of non-invasive light flicker stimulation at different frequencies on the functional properties of neurons in the primary visual cortex of adult mice, aiming to uncover how such stimulation modulates this region and, consequently, affects overall brain function. MethodsThree groups of adult mice (approximately 12 weeks old) were exposed to light flicker stimulation at frequencies of 20 Hz, 40 Hz, and 60 Hz, respectively, for a duration of two months. A control group was exposed to the same light intensity without flickering. Following the stimulation period, in vivo multi-channel electrophysiological recordings were conducted. During these recordings, anesthetized mice were presented with various types of moving sinusoidal light gratings to assess the effects of different flicker frequencies on the functional properties of neurons in the primary visual cortex. ResultsThe experimental results demonstrate that two months of light flicker stimulation at 20 Hz, 40 Hz, and 60 Hz enhances the orientation tuning capabilities of neurons in the primary visual cortex. Specifically, 40 Hz and 60 Hz stimulation improved contrast sensitivity, whereas 20 Hz had no significant effect. Further analysis revealed that all three frequencies reduced neuronal response variability (as measured by the Fano factor), increased the signal-to-noise ratio, and decreased noise correlation (r_sc) between neurons. ConclusionNon-invasive light flicker stimulation enhances orientation tuning (e.g., orientation bias index) and contrast sensitivity (e.g., contrast threshold and C₅₀) in neurons of the primary visual cortex. This enhancement is likely due to improved information processing efficiency, characterized by reduced neuronal variability and increased signal-to-noise ratio. These findings suggest that the primary visual cortex can achieve precise and efficient information encoding in complex lighting environments by selectively adapting to different flicker frequencies and optimizing receptive field properties. This study provides new experimental evidence on how various types of light flicker influence visual perception and offers insights into the mechanisms through which specific frequencies enhance brain function.

Objective: To explore the relationship of physical activity (PA) and sedentary behavior (SB) with cardiorespiratory fitness (CRF) among middle schoold students in Tibet, so as to provide empirical references for improving the cardiorespiratory fitness and health levels of adolescents in Tibet. Methods: From August to December 2020, 1 225 junior and senior high school students were selected from 2 middle schools in Lhasa, Tibet Autonomous Region, using the stratified cluster random sampling method. Triaxial accelerometers were used to evaluate PA and SB behaviors, and the 20 meter shuttle run was employed to assess CRF among the middle school students. Isochronous substitution modeling was used to analyze the associations of SB, low intensity physical activity (LPA), and moderate vigorous physical activity (MVPA) with CRF, and the saturation threshold effect in the dose response relationship between MVPA and CRF was analyzed through restricted cubic spline and two stage linear regression. Results: After adjusting for covariates such as gender, body mass index and sleep quality score, isotemporal substitution analysis showed that among junior high school students aged 13-15, replacing 30 minutes of SB ( B =1.73) or LPA ( B =2.38) with MVPA were positively associated with CRF (both P <0.05). Among senior high school students aged 16-18, replacing SB ( B =0.99) or LPA ( B =1.38) with MVPA were also positively associated with CRF (both P <0.05). Restricted cubic spline and two piecewise linear regression analyses indicated that only middle school girls aged 13-18 exhibited a saturation threshold effect between MVPA and CRF (logarithmic likelihood ratio test=0.03), with the optimal CRF improvement observed at 60 minutes of MVPA per day ( B=0.13, P ＜ 0.01). Conclusions Reducing SB and LPA while increasing MVPA can improve CRF in Tibetan middle school students. To maximize CRF improvement, middle school girls should engage in at least 60 minutes of MVPA daily.