BACKGROUND:Periprosthetic joint infection is the most common cause of early failure after total knee replacement.The current methods of preventing periprosthetic joint infection by improving the surface of the prosthesis have limitations to varying degrees.OBJECTIVE:To construct a coating material that can stably improve the surface of the implant,prevent the initial floating bacterial infection of periprosthetic infection,and regulate the bone transfer function around the implant.METHODS:(1)Material preparation:YGF polypeptide(which promotes bone formation),LL-37 polypeptide(with antibacterial properties)and YGF+LL-37 composite peptide were prepared by Fmoc solid phase peptide synthesis technology.The titanium-based materials were immersed in the three polypeptide solutions for 2 hours to obtain YGF coating,LL-37 coating and composite peptide coating coated titanium sheets.(2)In vitro experiment:Uncoated titanium sheets and coated titanium sheets were co-cultured with Escherichia coli(or Staphylococcus aureus)and the colonies were counted by plate method.MC3T3 cells were inoculated on the surface of uncoated titanium sheet and coated titanium sheet,respectively.Alizarin red staining was used to observe the calcium salt deposition on the surface of the material.Western blot assay was used to detect the protein expression of RUNX2,osteocalcin,osteopontin,and bone morphogenetic protein 2.(3)Animal experiment:24 SD rats were randomly divided into three groups:the blank group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal;the control group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension;the experimental group(n=8)was implanted with composite peptide coated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension.After 5 weeks of implantation,micro-CT examination,hematoxylin-eosin staining and immunohistochemical staining of femur specimens were performed.RESULTS AND CONCLUSION:(1)In vitro experiment:Compared with uncoated titanium sheet and YGF coated titanium sheet,LL-37 coated and composite peptide coated titanium sheet could significantly inhibit the growth and reproduction of Escherichia coli and Staphylococcus aureus.Compared with uncoated titanium sheets and LL-37-coated titanium sheets,YGF-coated and composite peptide-coated titanium sheets could promote calcium salt deposition in osteoblasts and increase the protein expression of RUNX2,osteocalcin,osteopontin and bone morphogenetic protein 2.(2)Animal experiment:Micro-CT test showed that the control group had less bone mass than the blank group and the experimental group.Hematoxylin-eosin staining showed that there was a large amount of fibrous tissue around the nail channel in the control group,only a small amount of tissue fibrosis around the nail channel in the blank group,and only a small amount of tissue fibrosis around the nail channel in the experimental group.Immunohistochemical staining showed that the protein expression of interleukin 1β and tumor necrosis factor α in the control group was higher than that in the blank group and the experimental group,and the expression of osteocalcin,RUNX2 and osteopontin in the experimental group was higher than that in the blank group and the control group.(3)The results show that the titanium-based material coated with YGF+LL-37 composite peptide coating has good antibacterial ability and can promote bone transfer around the implant.

BACKGROUND:Periprosthetic joint infection is the most common cause of early failure after total knee replacement.The current methods of preventing periprosthetic joint infection by improving the surface of the prosthesis have limitations to varying degrees.OBJECTIVE:To construct a coating material that can stably improve the surface of the implant,prevent the initial floating bacterial infection of periprosthetic infection,and regulate the bone transfer function around the implant.METHODS:(1)Material preparation:YGF polypeptide(which promotes bone formation),LL-37 polypeptide(with antibacterial properties)and YGF+LL-37 composite peptide were prepared by Fmoc solid phase peptide synthesis technology.The titanium-based materials were immersed in the three polypeptide solutions for 2 hours to obtain YGF coating,LL-37 coating and composite peptide coating coated titanium sheets.(2)In vitro experiment:Uncoated titanium sheets and coated titanium sheets were co-cultured with Escherichia coli(or Staphylococcus aureus)and the colonies were counted by plate method.MC3T3 cells were inoculated on the surface of uncoated titanium sheet and coated titanium sheet,respectively.Alizarin red staining was used to observe the calcium salt deposition on the surface of the material.Western blot assay was used to detect the protein expression of RUNX2,osteocalcin,osteopontin,and bone morphogenetic protein 2.(3)Animal experiment:24 SD rats were randomly divided into three groups:the blank group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal;the control group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension;the experimental group(n=8)was implanted with composite peptide coated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension.After 5 weeks of implantation,micro-CT examination,hematoxylin-eosin staining and immunohistochemical staining of femur specimens were performed.RESULTS AND CONCLUSION:(1)In vitro experiment:Compared with uncoated titanium sheet and YGF coated titanium sheet,LL-37 coated and composite peptide coated titanium sheet could significantly inhibit the growth and reproduction of Escherichia coli and Staphylococcus aureus.Compared with uncoated titanium sheets and LL-37-coated titanium sheets,YGF-coated and composite peptide-coated titanium sheets could promote calcium salt deposition in osteoblasts and increase the protein expression of RUNX2,osteocalcin,osteopontin and bone morphogenetic protein 2.(2)Animal experiment:Micro-CT test showed that the control group had less bone mass than the blank group and the experimental group.Hematoxylin-eosin staining showed that there was a large amount of fibrous tissue around the nail channel in the control group,only a small amount of tissue fibrosis around the nail channel in the blank group,and only a small amount of tissue fibrosis around the nail channel in the experimental group.Immunohistochemical staining showed that the protein expression of interleukin 1β and tumor necrosis factor α in the control group was higher than that in the blank group and the experimental group,and the expression of osteocalcin,RUNX2 and osteopontin in the experimental group was higher than that in the blank group and the control group.(3)The results show that the titanium-based material coated with YGF+LL-37 composite peptide coating has good antibacterial ability and can promote bone transfer around the implant.

Chronic heart failure （CHF） is a complex clinical syndrome caused by ventricular dysfunction， with mitochondrial energy metabolism disorder being a critical factor in disease progression. Heart-Yang deficiency syndrome， as the core pathogenesis of CHF， persists throughout the disease course. Insufficiency of heart-Yang leads to weakened warming and propelling functions， resulting in the accumulation of phlegm-fluid， blood stasis， and dampness. This eventually causes Qi stagnation with phlegm obstruction and blood stasis with water retention， forming a vicious cycle that exacerbates disease progression. According to the theory of reinforcing Yang， the clinical experience of the traditional Chinese medicine （TCM） master Tang Zuxuan in treating CHF with heart-Yang deficiency syndrome， and achievements from molecular biological studies， this study innovatively proposes an integrated research framework of "TCM syndrome differentiation and staging-mitochondrial metabolism mechanisms-intervention with Yang-reinforcing prescriptions" which is characterized by the integration of traditional Chinese and Western medicine. Heart-Yang deficiency syndrome is classified into mild （Stage Ⅰ-Ⅱ）， severe （Stage Ⅲ）， and critical （Stage Ⅳ） stages. The study elucidates the precise correlations between the pathogenesis of each stage and mitochondrial metabolism disorders from theoretical， pathophysiological， and therapeutic perspectives. The mild stage is characterized by impaired biogenesis and substrate-utilization imbalance， corresponding to heart-Yang deficiency and phlegm-fluid aggregation. Linggui Zhugantang and similar prescriptions can significantly improve the expression of peroxisome proliferator-activated receptor gamma co-activator-1α（PGC-1α）/silent information regulator 2 homolog 1 （SIRT1） and ATPase activity. The severe stage centers on oxidative stress and structural damage， reflecting Yang deficiency with water overflow and phlegm-blood stasis intermingling. At this stage， Zhenwu Tang and Qiangxin Tang can effectively mitigate oxidative stress damage， increase adenosine triphosphate （ATP） content， and repair mitochondrial structure. The critical stage arises from calcium overload and mitochondrial disintegration， leading to the collapse of Yin-Yang equilibrium. At this stage， Yang-restoring and crisis-resolving prescriptions such as Fuling Sini Tang and Qili Qiangxin capsules can inhibit abnormal opening of the mitochondrial permeability transition pore （MPTP）， reduce cardiomyocyte apoptosis rate， and protect mitochondrial function. By summarizing the characteristics of mitochondrial energy metabolism disorders at different stages of CHF， this study explores the application of the theory of reinforcing Yang in treating heart-Yang deficiency syndrome and provides new insights for the clinical diagnosis and treatment of CHF.

Chronic heart failure （CHF） is a group of complex clinical syndromes caused by abnormal changes in the structure and/or function of the heart due to various reasons， resulting in disorders of ventricular contraction and/or diastole. CHF is a condition where primary diseases such as coronary heart disease， hypertension and pulmonary heart disease recur frequently and persist for a long time， presenting blood stasis in meridians and collaterals， stagnation of water and dampness， and accumulation of Qi in collaterals. Its pathogenesis is complex and may involve myocardial energy metabolism disorders， oxidative stress responses， myocardial cell apoptosis， autophagy， inflammatory responses， etc. According to the theory of restraining hyperactivity to acquire harmony， we believe that under normal circumstances， the adenosine monophosphate-activated protein kinase （AMPK） signaling pathway functions normally， maintaining human physiological activities and energy metabolism. Under pathological conditions， the AMPK signaling pathway is abnormal， causing energy metabolism disorders， inflammatory responses， and myocardial fibrosis. Traditional Chinese medicine （TCM） can regulate the AMPK signaling pathway through multiple mechanisms， targets， and effects， effectively curbing the occurrence and development of CHF. It has gradually become a research hotspot in the prevention and treatment of this disease. Guided by the theory of TCM， our research group， through literature review， summarized the relationship between the AMPK pathway and CHF and reviewed the research progress in the prevention and control of CHF with TCM active ingredients， TCM compound prescriptions， and Chinese patent medicines via regulating the AMPK pathway. The review aims to clarify the mechanism and targets of TCM in the treatment of CHF by regulating the AMPK pathway and guide the clinical treatment and drug development for CHF.

ObjectiveTo explore the mechanism of ventricular remodeling mediated by the p38 mitogen-activated protein kinase （MAPK）/nuclear factor kappa B （NF-κB） signaling pathway in the rat model of chronic heart failure （CHF） with heart-blood stasis syndrome， as well as the intervention effect of Danhong injection. MethodsIn vivo experiment： SPF-grade male SD rats were assigned via the random number table method into 4 groups： Sham operation， model， captopril （8.8 mg·kg^-1）， and Danhong injection （6.0 mL·kg^-1）. The model of CHF with heart-blood stasis syndrome was established by abdominal aortic constriction， and the sham operation group only underwent laparotomy without constriction. All the groups were treated continuously for 15 days. The tongue color of rats was observed. Echocardiography， hemorheology， heart mass index （HMI）， and left ventricular mass index （LVMI） were measured. Hematoxylin-eosin （HE） staining and Masson staining were performed to observe the pathological and fibrotic changes of the myocardial tissue. Enzyme-linked immunosorbent assay （ELISA） was employed to quantify the levels of N-terminal pro-B-type natriuretic peptide （NT-proBNP）， interleukin-6 （IL-6）， angiotensin Ⅱ （AngⅡ）， tumor necrosis factor-α （TNF-α）， and Creactive protein （CRP） in the serum， as well as the levels of matrix metalloproteinase-2 （MMP-2） and matrix metalloproteinase-9 （MMP-9） in the myocardial tissue. Western blot was used to quantify the protein levels of p-p38 MAPK/p38 MAPK and p-NF-κB p65/NF-κB p65 in the myocardial tissue. In vitro experiment： H9C2 cardiomyocytes were treated with 1×10^-6 mol·L^-1 AngⅡ to establish a model of myocardial hypertrophy. H9C2 cardiomyocytes were allocated into normal， model， inhibitor + Danhong injection， Danhong injection （20 mL·L^-1）， and inhibitor （SB203580， 5 μmol·L^-1） groups. CCK-8 assay was used to detect the viability of H9C2 cardiomyocytes. Rhodamine-labeled phalloidin staining was used to reveal the area of cardiomyocytes. Real-time PCR was performed to determine the mRNA levels of atrial natriuretic peptide （ANP） and brain natriuretic peptide （BNP）. Western blot was used to assess the protein levels of p-p38 MAPK/p38 MAPK and p-NF-κB p65/NF-κB p65. ResultsIn vivo experiment： Compared with the sham operation group， the model group showed purplish-dark tongue with decreased R， G， B values of the tongue surface （P<0.01）， increased whole blood viscosity （at low， medium， and high shear rates） （P<0.01）， decreased left ventricular ejection fraction （LVEF） and left ventricular fractional shortening （LVFS） （P<0.01）， increased left ventricular end-diastolic diameter （LVIDd）， left ventricular end-systolic diameter （LVIDs）， and left ventricular posterior wall thickness at end-diastole （LVPWd） （P<0.01）， raised LVMI and HMI （P<0.01）， and elevated levels of NT-proBNP， TNF-α， IL-6， and CRP in the serum and MMP-2 and MMP-9 in the myocardial tissue （P<0.01）. The HE and Masson staining of the myocardial tissue showed compensatory myocardial hypertrophy， fibrosis， and massive inflammatory cell infiltration in the model group. Additionally， the model group presented up-regulated protein levels of p-p38 MAPK/p38 MAPK and p-NF-κB p65/NF-κB p65 in the myocardial tissue （P<0.01）. Compared with the model group， each administration group showed increased R， G， B values of the tongue surface （P<0.05， P<0.01）， decreased whole blood viscosity （at low， medium， and high shear rates） （P<0.05， P<0.01）， increased LVEF and LVFS （P<0.01）， decreased LVIDd， LVIDs， and LVPWd （P<0.05， P<0.01）， declined LVMI and HMI （P<0.05， P<0.01）， and lowered levels of NT-proBNP， TNF-α， IL-6， and CRP in the serum and MMP-2 and MMP-9 in the myocardial tissue （P<0.01）. HE and Masson staining showed alleviated compensatory myocardial hypertrophy， reduced fibrosis， and decreased expression of p-p38 MAPK/p38 MAPK and p-NF-κB p65/NF-κB p65 in the myocardial tissue （P<0.01）. In vitro experiment： When the concentration of Danhong injection reached 20 mL·L^-1， the survival rate of H9C2 cardiomyocytes was the highest （P<0.01）. Compared with the normal group， the model group showed up-regulated mRNA levels of ANP and BNP （P<0.01）， increased relative cell surface area （P<0.01）， and raised protein levels of p-p38 MAPK/p38 MAPK and p-NF-κB p65/NF-κB p65 （P<0.01）. Compared with the model group， each administration group showed down-regulated mRNA levels of ANP and BNP （P<0.01）， reduced relative cell surface area （P<0.05， P<0.01）， and down-regulated protein levels of p-p38 MAPK/p38 MAPK and p-NF-κB p65/NF-κB p65 （P<0.05， P<0.01）. ConclusionDanhong injection can regulate ventricular remodeling through the p38 MAPK/NF-κB pathway， thereby exerting a protective effect on the rat model of CHF with heart-blood stasis syndrome.

Chronic heart failure （CHF） refers to a clinical syndrome in which the function or structure of the heart is changed due to damage to the original myocardium， resulting in reduced pumping and/or filling functions of the heart. In recent years， the mechanisms， pathways， and targets of traditional Chinese medicine （TCM） in the treatment of CHF have been continuously confirmed， and the application of TCM theories in guiding the syndrome differentiation and precise treatment of CHF is currently a research hotspot. On the basis of the syndrome differentiation and treatment in TCM， Professor LI Candong innovatively proposed the thinking of five differentiation： Disease differentiation， syndrome differentiation， pathogenesis differentiation， symptom differentiation， and individual differentiation. This article explores the clinical diagnosis and treatment of CHF from this thinking， emphasizing comprehensive syndrome differentiation， objective analysis， dynamic assessment， and individualized treatment. In terms of diagnosis， the first is to identify the disease name， cause， location， severity， and type of CHF， determine the type and its evolution， and clarify the process of transmission and transformation between deficiency and excess. Secondly， it is necessary to distinguish the authenticity， severity， primary and secondary， urgency and complexity of CHF syndromes， providing scientific guidance for syndrome differentiation and treatment. Thirdly， according to the symptoms and the principles of deficiency and excess， the physician should identify the core pathogenesis of CHF from the perspectives of Qi， blood， Yin， Yang， deficiency， stasis， phlegm， water， and toxins. Fourthly， from the macro， meso and micro levels， the physician should carefully distinguish the presence or absence， severity， authenticity， and completeness of the symptoms to guide the diagnosis and treatment process of CHF. Finally， personalized medication for CHF should be promoted based on the patient's gender， age， constitution， and living habits. In terms of treatment， based on the thinking of five differentiation， we propose that the treatment of CHF should integrate the disease and syndrome， clarify the pathogenesis， and apply precise treatment. The treatment should be people-oriented， staged， and typed， and the medication should be adjusted according to symptoms. This diagnostic and therapeutic approach is based on the holistic concept and syndrome differentiation and treatment， and combines the three causes for appropriate treatment， providing new ideas and insights for the diagnosis and treatment of CHF.

Objective: To explore the characteristics of the diversity and composition of oral microbial flora with age, and to provide a reference for understanding the succession of oral microecology at different ages. Methods: Oral rinse 16S rRNA (V4 region) sequencing data from 9 021 participants 14-69 years of age in the 2009-2012 National Health and Nutrition Examination Survey (NHANES) were analyzed. Alpha diversity (Observed OTUs, Faith’s PD, Shannon Index), beta diversity (Bray-Curtis and UniFrac), and genus-level composition were examined using weighted generalized linear models (GLMs), including quadratic terms for age and adjusting for key covariates (gender, race/ethnicity, BMI, smoking status, and periodontitis severity). Results: Alpha diversity demonstrated a clear inverted U-shaped trajectory across age, peaking at 25-30 years old and declining thereafter. This trend remained consistent across sex, race, smoking, and periodontal health strata. Beta diversity analyses revealed a modest but steady age-related shift in community structure. Genus-level analyses revealed that Rothia, Prevotella_6, and Lactobacillus increased steadily with age, while Haemophilus, Porphyromonas, and Corynebacterium declined significantly. Notably, potential periodontopathogens, such as Fusobacterium and Treponema_2, peaked in early adulthood before declining with age. Conclusion Age is an important driver of oral microbial succession, and the oral microbiome exhibits dynamic changes across different life stages. Future longitudinal and multi-omic studies are warranted to elucidate the mechanisms underlying these age-related trajectories.

ObjectiveTo investigate the incidence and influencing factors of posttraumatic stress disorder （PTSD） three months after a traffic accident， and to explore the role of social support and coping strategies. MethodsA total of 117 individuals exposed to trauma following road traffic accidents were recruited. General demographic and clinical information was collected within one week， and the hamilton anxiety rating scale （HAMA）， the hamilton depression rating scale-24 （HAMD-24）， the social support rating scale （SSRS）， and the simplified coping style questionnaire （SCSQ） were administered. A 3-month follow-up was subsequently conducted， during which PTSD symptoms were assessed using the post-traumatic stress disorder checklist for DSM-5 （PCL-5）. Participants were divided into a PTSD group and a non-PTSD group according to whether PTSD occurred. Between-group comparisons were performed using the Mann-Whitney U non-parametric test or the χ² test， as appropriate. Spearman correlation analysis was used to examine the associations between general characteristics and PCL-5 scores. Binary Logistic regression was applied to identify factors influencing PTSD， and receiver operating characteristic （ROC） curve analysis was conducted to evaluate the diagnostic value of the SCSQ and SSRS. ResultsDuring the 3-month follow-up of the 117 trauma-exposed individuals， 17 cases developed PTSD， with a higher proportion of females （70.59%）. Between-group comparisons showed that， compared with the PTSD group， the non-PTSD group had higher scores for positive coping， objective support， and subjective support （P<0.05）， and lower scores for negative coping， HAMA， HAMD， and PCL-5 （P<0.05）. Correlation analysis indicated that female gender， negative coping， and higher HAMA and HAMD scores were associated with greater PTSD severity. Logistic regression analysis demonstrated that educational level （OR=1.715， 95% CI： 1.020-2.883， P=0.042） and negative coping （OR=1.590， 95% CI： 1.003-2.522， P=0.048） were risk factors for PTSD， whereas objective support （OR=0.646， 95% CI： 0.451-0.925， P=0.017） was a protective factor. The ROC analysis showed that the total SCSQ score and its negative and positive coping dimensions， the total SSRS score and its subjective and objective support dimensions， as well as their combined use， all demonstrated good discriminative ability in distinguishing between the PTSD and non-PTSD groups. ConclusionThe results suggest that individuals who are female， with higher HAMA and HAMD scores after a motor vehicle accident， and those with lower social support and negative coping strategies， should be given particular attention. Early interventions for these individuals may reduce the incidence of PTSD.

ObjectiveThe exacerbating trend of global population aging poses profound socioeconomic and public health challenges, making the comprehensive elucidation of biological aging mechanisms and the discovery of effective anti-aging interventions an urgent priority in the life sciences. Based on our previous serum metabolomics findings that dimethylglycine, an intermediate metabolite of amino acid metabolism naturally present in the human body, was significantly enriched in the serum of longevity families, this study aimed to systematically investigate the anti-aging effects of dimethylglycine both in living organisms and in controlled laboratory environments, and to preliminarily elucidate its underlying molecular mechanisms. While existing literature indicates that dimethylglycine possesses antioxidant and immunomodulatory properties, its direct anti-aging efficacy and the specific molecular pathways through which it operates remain largely unexplored. MethodsTo comprehensively evaluate the anti-aging properties of dimethylglycine, we utilized replicative senescent human embryonic lung fibroblasts, specifically the WI-38 cell line, as an experimental model in a controlled laboratory environment. Cell viability and safety were thoroughly assessed using Cell Counting Kit-8 and lactate dehydrogenase release assays across various concentrations of dimethylglycine. The impact of dimethylglycine on cellular senescence phenotypes, oxidative stress, and proliferative capacity was evaluated via senescence-associated beta-galactosidase staining, reactive oxygen species fluorescence detection, and 5-ethynyl-2'-deoxyuridine incorporation assays. Furthermore, the molecular alterations of senescence-associated secretory phenotype factors and core senescence signaling pathways were quantified using quantitative reverse transcription polymerase chain reaction for the messenger RNA levels of interleukin-6, interleukin-8, p21, and matrix metalloproteinase-1, and enzyme-linked immunosorbent assay for the measurement of p16 and p21 protein expression levels. For the living organism model, the wild-type nematode Caenorhabditis elegans was used to evaluate systemic physiological effects. We conducted a comprehensive lifespan analysis at 20°C, heat stress resistance survival assays at 35℃, senescence-associated beta-galactosidase staining, lipofuscin accumulation tracking, intracellular reactive oxygen species measurement, and Oil Red O staining to ascertain systemic lipid accumulation. Additionally, network pharmacology bioinformatics tools, including PharmMapper and STRING databases, and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis were utilized to predict target pathways, alongside highly detailed molecular docking simulations utilizing SwissDock and Protein-Ligand Interaction Profiler to examine interactions with the cytochrome P450 family 2 subfamily C member 9 protein. ResultsThe experimental outcomes robustly demonstrate the potent anti-aging capabilities of dimethylglycine. At the cellular level, toxicity analyses firmly confirmed that dimethylglycine is highly safe; continuous treatment with 50 mol/L and 70 mol/L of dimethylglycine for 5 d did not induce any cellular membrane damage or cytotoxicity, but rather actively promoted cellular proliferation. Utilizing the optimal standardized concentration of 50 mol/L, dimethylglycine treatment significantly ameliorated senescent phenotypic markers in human embryonic lung fibroblasts, which was evidenced by a drastic and highly significant reduction in the senescence-associated beta-galactosidase positive cell percentage (P<0.000 1) and intracellular reactive oxygen species levels (P<0.000 1), alongside a marked increase in the 5-ethynyl-2'-deoxyuridine-positive proliferation rate (P=0.003 5). On a molecular expression scale, dimethylglycine significantly downregulated the messenger RNA expression of multiple core senescence-associated secretory phenotype inflammatory factors, including interleukin-6, interleukin-8, p21, and matrix metalloproteinase-1. Concurrently, it effectively suppressed the protein expression of critical cell cycle arrest markers, diminishing p16 protein levels by 57.3% (P=0.000 4) and p21 protein levels by 27.2% (P=0.000 7). In the nematode Caenorhabditis elegans animal model, dimethylglycine significantly extended the mean lifespan from 20.402 d to an impressive 23.066 d (P<0.000 1) and notably enhanced overall survival rates under severe heat stress environmental conditions (P=0.017). Furthermore, systemic dimethylglycine intervention significantly mitigated age-related physiological decline by decreasing bodily lipofuscin accumulation (P<0.000 1), significantly reducing senescence-associated beta-galactosidase activity, lowering systemic reactive oxygen species fluorescence (P=0.008), and effectively alleviating overall fat accumulation (P<0.000 1). Mechanistically, extensive network pharmacology and Kyoto Encyclopedia of Genes and Genomes analyses strongly revealed that the potential targets of dimethylglycine are significantly enriched in fundamental drug metabolism and oxidative stress response pathways. Precision molecular docking simulations conclusively demonstrated that dimethylglycine forms highly stable structural interactions with the cytochrome P450 family 2 subfamily C member 9 protein, specifically highlighting the definitive formation of 5 stable hydrogen bonds involving serine 365, leucine 366, and serine 429 residues, as well as two critical salt bridge formations with arginine 97 and histidine 368 residues. It is additionally predicted to interact favorably with glutathione S-transferase family proteins. ConclusionDimethylglycine exhibits a profoundly significant and multifaceted anti-aging activity at both the cellular and entire living animal levels. By powerfully alleviating oxidative stress, heavily suppressing the core p16 and p21-dependent cellular senescence signaling pathways, and substantially mitigating the detrimental senescence-associated secretory phenotype, dimethylglycine effectively delays fundamental cellular senescence processes and drastically extends whole-organism lifespan. The biological mechanisms driving these robust protective effects are highly likely closely associated with its direct stable interactions with crucial metabolic and detoxifying enzyme systems, such as cytochrome P450 family 2 subfamily C member 9 and glutathione S-transferase family proteins, thereby systemically improving metabolic dysregulation and restoring critical redox homeostasis. This comprehensive study provides highly solid experimental evidence supporting dimethylglycine as a highly potent and safe potential anti-aging intervention agent, while simultaneously offering a clear molecular mechanistic explanation for the previously documented high abundance of dimethylglycine observed within exceptionally long-lived human populations.

ObjectiveTo investigate the role of interleukin （IL）-17A in acute inhalational pneumonia induced by the highly drug-resistant and hypervirulent Staphylococcus aureus strain USA300-R in mice. MethodsAn acute inhalational pneumonia model was established in mice using an aerosolized pulmonary delivery technique. RNA sequencing （RNA-seq） and enzyme-linked immunosorbent assay （ELISA） were employed to examine the expression dynamics of Il17a mRNA and IL-17A protein， respectively， in the lungs of infected mice. Il17a knockout （Il17a^-/-） mice were generated using CRISPR/Cas9 gene editing technology. The survival rate， body weight， bacterial load in lung tissue， and histopathological changes were compared between Il17a^-/- and wild-type （WT） mice following inhalational infection with USA300-R. Results12 hours after USA300-R infection， compared to pre-infection， the expression level of Il17a mRNA in lung tissue and the level of IL-17A protein in bronchoalveolar lavage fluid （BALF） increased by approximately 50-fold （P<0.01） and 6-fold （P<0.001）， respectively. Compared to WT mice， Il17a^-/- mice exhibited approximately 10-fold higher bacterial loads in lung tissue at both 12 and 24 hours post-infection （P<0.001， P<0.05）. However， they showed significantly attenuated lung histopathological injury， reduced alveolar wall thickening， markedly decreased neutrophil infiltration， and an approximately 50% improvement in survival rate （P<0.05）. ConclusionIn acute Staphylococcus aureus USA300-R inhalational pneumonia， IL-17A contributes to bacterial clearance by recruiting neutrophils； however， excessive neutrophil infiltration exacerbates pulmonary inflammation and injury， reduces survival rates， and represents a potential therapeutic target.