BACKGROUND:Knee osteoarthritis(KOA)is a common chronic inflammatory disease that causes damage to joint cartilage and surrounding tissues.Immune cells play an important role in the immune-inflammatory response in knee osteoarthritis,but the specific mechanisms involved are still not fully understood. OBJECTIVE:To evaluate the potential causal relationship between 731 immune cell phenotypes and the risk of knee osteoarthritis using Mendelian randomization. METHODS:Summary statistics of genome-wide association studies(GWAS)for 731 immune cell phenotypes(from GCST0001391 to GCST0002121)obtained from the GWAS catalog and GWAS data for knee osteoarthritis from the IEUGWAS database(ebi-a-GCST007090)were used.Inverse variance-weighted method,MR-Egger regression,weighted median method,weighted mode method,and simple mode method were employed to investigate the causal relationship between immune cells and knee osteoarthritis.Sensitivity analyses were conducted to assess the reliability of the Mendelian randomization results.Reverse Mendelian randomization analysis was also performed using the same methods. RESULTS AND CONCLUSION:The forward MR analysis indicated significant causal relationships(FDR<0.20)between knee osteoarthritis and four immune cell phenotypes,namely CD27 on CD24+CD27+in B cells(OR=1.026,P=0.000 26,Pfdr=0.18),CD33 on CD33dim HLA DR-in myeloid cells(OR=1.014,P=0.000 50,Pfdr=0.18),and CD45RA+CD28-CD8br%CD8br in Treg cells(OR=1.001,P=0.000 78,Pfdr=0.18),and PDL-1 on monocytes in mononuclear cells(OR=0.952,P=0.000 98,Pfdr=0.18).These immune cell phenotypes showed direct positive or negative causal associations with the risk of knee osteoarthritis.Reverse Mendelian randomization analysis revealed no significant causal relationships(FDR<0.20)between knee osteoarthritis as exposure and any of the 731 immune cell phenotypes.The results of sensitivity analysis show that the P-values of the Cochran's Q test and the MR-Egger regression method for bidirectional Mendelian randomization were both greater than 0.05,indicating that there is no significant heterogeneity and pleiotropy in the causal effect analysis between immune cell phenotypes and knee osteoarthritis.To conclude,there may be four potential causal relationships between immune cell phenotypes,such as CD27 on CD24+CD27+cells,CD33 on CD33dim HLA DR-cells,CD45RA+CD28-CD8br%CD8br cells,and PDL-1 on monocytes,and knee osteoarthritis.These findings provide valuable clues for studying the biological mechanisms of knee osteoarthritis and exploring early prevention and treatment strategies.They also offer new directions for the development of intervention drugs.

BACKGROUND:Solute carrier family 1 member 5(SLC1A5)plays a potential role in a variety of diseases,but the exact mechanism of action is unclear.The construction of stable SLC1A5 overexpression and knockdown cell models can provide a powerful experimental tool for in-depth study of the exact role and mechanism of SLC1A5 in diseases and the discovery of potential therapeutic targets. OBJECTIVE:To construct lentiviral vectors for overexpression and knockdown of mouse SLC1A5 and establish stable transfected RAW264.7 cell lines,so as to provide an experimental foundation for further investigation of the role of SLC1A5 in inflammation. METHODS:Primers were designed and synthesized based on the SLC1A5 gene sequence,and the gene segment was amplified using polymerase chain reaction.Subsequently,the target gene segment was directionally inserted into the GV492 vector plasmid,which had been digested with AgeI/NheI enzymes,to construct recombinant lentiviral plasmids.Positive clones were further selected,and their sequences were confirmed.The pHelper1.0 plasmid vector and pHelper2.0 plasmid vector,along with the target plasmid vector,was co-cultured with 293T cells for transfection,resulting in the production and titration of lentiviral stocks.Furthermore,RAW264.7 cells were cultured in vitro,and the working concentration of puromycin was determined.Lentiviruses were separately co-cultured with RAW264.7 cells,and transfection efficiency was determined by measuring fluorescence intensity.Stable transfected cells were selected using puromycin,and real-time fluorescence quantitative PCR and western blot assay were employed to assess the gene and protein expression levels of SLC1A5 in stably transfected cell lines. RESULTS AND CONCLUSION:(1)Sequencing results indicated a perfect match between the sequencing and target sequences,confirming the successful construction of recombinant lentiviral vectors.(2)The titer for the overexpression SLC1A5 lentivirus was 1×109 TU/mL,while the titer for the knockdown SLC1A5 lentivirus was 3×109 TU/mL.(3)The working concentration of puromycin for RAW264.7 cells was determined to be 3 μg/mL.(4)The optimal conditions for transfecting RAW264.7 cells with overexpression/knockdown expression of SLC1A5 lentivirus involved the use of HiTransG P transfection enhancer with a multiplicity of infection value of 50.(5)A significant upregulation of the gene and protein expression levels of SLC1A5 was detected in cell lines stably overexpressing SLC1A5,while gene and protein expression levels of SLC1A5 were significantly decreased in the knockdown stable cell lines.These findings indicate that lentiviral vectors for mouse SLC1A5 overexpression and knockdown have been successfully constructed and a stably transfected RAW264.7 cell line has been obtained.

Background The adverse effects of long working hours, shift rotation, and job stress on the physical and mental health of occupational populations require urgent attention. Objective To investigate and compare the positive rates of WMSDs between different industries, analyze the exposure status of long working hours, shift rotation, and job stress among key occupational groups, and evaluate the impacts of these factors on WMSDs in the manufacturing and service industries. Methods The study subjects were derived from key occupational populations in Yunnan Province, recruited by the Chinese National Occupational Health Literacy Monitoring Survey in 2022. A cross-sectional design was used for this survey. The key occupational populations were recruited from the secondary industry (manufacturing industry, metal mining and beneficiation industry, and non-metal mining and beneficiation industry) by stratified random sampling and from the tertiary industry (medical and healthcare industry, education industry, environmental sanitation industry, transportation industry, and express/takeaway delivery industry) by proportional probability sampling, and 12014 front-line workers were finally included as survey participants. General information, work-related factors (shift rotation, weekly working hours, job stress, etc.) and WMSDs assessment results were obtained through a web-based self-reported questionnaire, and the associations of long working hours, shift rotation, and job stress with WMSDs were analyzed using χ² test and logistic regression. Results The average positive rate of WMSDs among the key occupational groups in Yunnan Province was 77.2%. The positive rate of WMSDs in the secondary industry group was 69.4%, while it was 81.6% in the tertiary industry group, with a statistically significant difference (P<0.001). Among the eight surveyed sectors, the education sector had the highest positive rate of WMSDs (94.2%). The single-site WMSDs mainly involved the neck, shoulders, and low back. In the secondary industry, WMSDs was reported in 1−2 body parts, while in the tertiary industry, WMSDs was mainly reported in multiple (≥5) body parts. Long working hours (OR: 1.119, 1.165, 1.163, respectively), shift rotation (OR: 1.094, 1.199, 1.230, respectively), and job stress (OR: 1.795, 1.854, 2.006, respectively) were risk factors for WMSDs in the neck, shoulder, or low back, and all three were also risk factors for multi-site WMSDs. Moreover, as the number of involved body parts increased, the effects of long working hours and job stress became more pronounced. For 1-2, 3-4, and 5 or more body parts compared to no pain reported, their OR values were 0.971 (95%CI: 0.871, 1.082), 1.133 (95%CI: 1.004, 1.279), and 1.285 (95%CI: 1.155, 1.429) for long working hours, respectively, and the OR values were 1.009 (95%CI: 0.878, 1.160), 1.360 (95%CI: 1.174, 1.575), and 2.797 (95%CI: 2.471, 3.166) for job stress, respectively. Conclusion The positive rate of WMSDs is higher in the tertiary industry than that in the secondary industry among the key occupational groups in Yunnan Province. Long working hours, rotating shift work, and job stress could significantly increase the risk of WMSDs.

ObjectiveTo investigate the effects of Xijiao Dihuangtang （XJDHT） on mice with sepsis and cellular models of sepsis and explore its molecular mechanism in alleviating sepsis-induced inflammatory responses via regulating pyruvate kinase M2 （PKM2）-mediated one-carbon metabolism pathway. MethodsForty C57BL/6N mice were randomly divided into four groups： normal group， model group， low-dose XJDHT group （7.7 g·kg^-1）， and high-dose XJDHT group （15.4 g·kg^-1）. After one week of continuous gavage， sepsis was induced using cecal ligation and puncture （CLP） in groups except the normal group. 24 h after the surgery， mortality rates in all groups were recorded， and serum cytokines were measured by enzyme linked immunosorbent assay （ELISA）. Lung histopathology was examined by hematoxylin-eosin （HE） staining. During the in vitro experiment， the human monocytic leukemia cell line （THP-1） was exposed to various concentrations of XJDHT and treated with lipopolysaccharide （LPS） at a final concentration of 2 mg·L^-1 for 24 h. Cell apoptosis was detected using terminal deoxynucleotidyl transferase dUTP nick end labeling （TUNEL） assay. Protein levels of tumor necrosis factor-α （TNF-α）， interleukin-1β （IL-1β）， B-cell lymphoma 2 （Bcl-2）， and Bcl-2-associated X protein （Bax） were measured by Western blot. Transcriptome sequencing was performed to analyze differentially expressed genes in all groups and conduct gene ontology （GO） enrichment. Key genes in the one-carbon metabolism pathway， including pyruvate kinase M2 （PKM2）， 5-methyltetrahydrofolate-homocysteine methyltransferase （MTR）， and phosphoglycerate dehydrogenase （PHGDH）， were verified by Western blot. A PKM2 inhibition model was established using shikonin for further protein expression analysis. ResultsAnimal experiments showed that compared with the normal group， the model group exhibited significantly elevated body temperature and lung pathology （P<0.01） and increased serum TNF-α and IL-1β levels （P<0.01）. High-dose XJDHT reduced body temperature and lung tissue damage （P<0.01） and significantly decreased serum TNF-α and IL-1β levels （P<0.01）. Low-dose XJDHT treatment showed no significant temperature change （P<0.01） but reduced serum TNF-α and IL-1β levels （P<0.01）. Transcriptome sequencing and Western blot revealed significant differences in the expression of TNF-α， IL-1β， and one-carbon metabolism genes （PKM2， MTR， and PHGDH） （P<0.01）. Cell experiments demonstrated that compared to the normal group， the model group showed elevated protein expressions of TNF-α and IL-1β in THP-1 cells （P<0.01）， decreased Bcl-2/Bax ratio， and increased apoptosis （P<0.01）. Transcriptome sequencing and Western blot revealed significant differences in the expression of TNF-α， IL-1β， and one-carbon metabolism genes （PKM2， MTR， and PHGDH） （P<0.01）. Compared to the model group， high-dose XJDHT significantly increased Bax/Bcl-2 ratio and PHGDH protein expression （P<0.01） and effectively reduced cell apoptosis （P<0.01） while down-regulating protein expressions of TNF-α， IL-1β， PKM2， and MTR （P<0.01）. Low-dose XJDHT moderately increased Bax/Bcl-2 ratio and PHGDH protein expression （P<0.05）， reduced apoptosis （P<0.05）， and decreased IL-1β and MTR protein levels （P<0.05， P<0.01）， but there were no significant changes in TNF-α and PKM2 expression. After PKM2 inhibition by shikonin in THP-1 cells， the expression of protein related to one-carbon metabolism was detected. Compared with the blank group， the LPS-induced model group showed significantly upregulated PKM2 and MTR protein expression （P<0.01） and downregulated PHGDH expression （P<0.01）. Compared with the model group， shikonin treatment significantly reduced PKM2 expression （P<0.05）， increased PHGDH expression （P<0.01）， and decreased MTR expression （P<0.05）. ConclusionXJDHT can inhibit the release of inflammatory factors in sepsis， and its mechanism is related to the intervention of the PKM2-regulated one-carbon metabolism pathway in macrophages.

ObjectiveThis study leverages structural data from antigen-antibody complexes of the influenza A virus neuraminidase (NA) protein to investigate the spatial recognition relationship between the antigenic epitopes and antibody paratopes. MethodsStructural data on NA protein antigen-antibody complexes were comprehensively collected from the SAbDab database, and processed to obtain the amino acid sequences and spatial distribution information on antigenic epitopes and corresponding antibody paratopes. Statistical analysis was conducted on the antibody sequences, frequency of use of genes, amino acid preferences, and the lengths of complementarity determining regions (CDR). Epitope hotspots for antibody binding were analyzed, and the spatial structural similarity of antibody paratopes was calculated and subjected to clustering, which allowed for a comprehensively exploration of the spatial recognition relationship between antigenic epitopes and antibodies. The specificity of antibodies targeting different antigenic epitope clusters was further validated through bio-layer interferometry (BLI) experiments. ResultsThe collected data revealed that the antigen-antibody complex structure data of influenza A virus NA protein in SAbDab database were mainly from H3N2, H7N9 and H1N1 subtypes. The hotspot regions of antigen epitopes were primarily located around the catalytic active site. The antibodies used for structural analysis were primarily derived from human and murine sources. Among murine antibodies, the most frequently used V-J gene combination was IGHV1-12*01/IGHJ2*01, while for human antibodies, the most common combination was IGHV1-69*01/IGHJ6*01. There were significant differences in the lengths and usage preferences of heavy chain CDR amino acids between antibodies that bind within the catalytic active site and those that bind to regions outside the catalytic active site. The results revealed that structurally similar antibodies could recognize the same epitopes, indicating a specific spatial recognition between antibody and antigen epitopes. Structural overlap in the binding regions was observed for antibodies with similar paratope structures, and the competitive binding of these antibodies to the epitope was confirmed through BLI experiments. ConclusionThe antigen epitopes of NA protein mainly ditributed around the catalytic active site and its surrounding loops. Spatial complementarity and electrostatic interactions play crucial roles in the recognition and binding of antibodies to antigenic epitopes in the catalytic region. There existed a spatial recognition relationship between antigens and antibodies that was independent of the uniqueness of antibody sequences, which means that antibodies with different sequences could potentially form similar local spatial structures and recognize the same epitopes.

ObjectiveTo investigate the influence of histone deacetylase 3 (HDAC3) on the occurrence, development of psoriasis-like inflammation in mice, and the relative immune mechanisms. MethodsHealthy C57BL/6 mice aged 6-8 weeks were selected and randomly divided into 3 groups: control group (Control), psoriasis model group (IMQ), and HDAC3 inhibitor RGFP966-treated psoriasis model group (IMQ+RGFP966). One day prior to the experiment, the back hair of the mice was shaved. After a one-day stabilization period, the mice in Control group was treated with an equal amount of vaseline, while the mice in IMQ group was treated with imiquimod (62.5 mg/d) applied topically on the back to establish a psoriasis-like inflammation model. The mice in IMQ+RGFP966 group received intervention with a high dose of the HDAC3-selective inhibitor RGFP966 (30 mg/kg) based on the psoriasis-like model. All groups were treated continuously for 5 d, during which psoriasis-like inflammation symptoms (scaling, erythema, skin thickness), body weight, and mental status were observed and recorded, with photographs taken for documentation. After euthanasia, hematoxylin-eosin (HE) staining was used to assess the effect of RGFP966 on the skin tissue structure of the mice, and skin thickness was measured. The mRNA and protein expression levels of HDAC3 in skin tissues were detected using reverse transcription real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot (WB), respectively. Flow cytometry was employed to analyze neutrophils in peripheral blood and lymph nodes, CD4⁺ T lymphocytes, CD8⁺ T lymphocytes in peripheral blood, and IL-17A secretion by peripheral blood CD4⁺ T lymphocytes. Additionally, spleen CD4⁺ T lymphocyte expression of HDAC3, CCR6, CCR8, and IL-17A secretion levels were analyzed. Immunohistochemistry was used to detect the localization and expression levels of HDAC3, IL-17A, and IL-10 in skin tissues. ResultsCompared with the Control group, the IMQ group exhibited significant psoriasis-like inflammation, characterized by erythema, scaling, and skin wrinkling. Compared with the IMQ group, RGFP966 exacerbated psoriasis-like inflammatory symptoms, leading to increased hyperkeratosis. The psoriasis area and severity index (PASI) skin symptom scores were higher in the IMQ group than those in the Control group, and the scores were further elevated in the IMQ+RGFP966 group compared to the IMQ group. Skin thickness measurements showed a trend of IMQ+RGFP966>IMQ>Control. The numbers of neutrophils in the blood and lymph nodes increased sequentially in the Control, IMQ, and IMQ+RGFP966 groups, with a similar trend observed for CD4⁺ and CD8⁺ T lymphocytes in the blood. In skin tissues, compared with the Control group, the mRNA and protein levels of HDAC3 decreased in the IMQ group, but RGFP966 did not further reduce these expressions. HDAC3 was primarily located in the nucleus. Compared with the Control group, the nuclear HDAC3 content decreased in the skin tissues of the IMQ group, and RGFP966 further reduced nuclear HDAC3. Compared with the Control and IMQ groups, RGFP966 treatment decreased HDAC3 expression in splenic CD4⁺ and CD8⁺ T cells. RGFP966 treatment increased the expression of CCR6 and CCR8 in splenic CD4⁺ T cells and enhanced IL-17A secretion by peripheral blood and splenic CD4⁺ T lymphocytes. Additionally, compared with the IMQ group, RGFP966 reduced IL-10 protein levels and upregulated IL-17A expression in skin tissues. ConclusionRGFP966 exacerbates psoriatic-like inflammatory responses by inhibiting HDAC3, increasing the secretion of the cytokine IL-17A, and upregulating the expression of chemokines CCR8 and CCR6.

Objective: To investigate the association between bedtime screen use and sleep health among fourth and fifthgrade primary school students, so as to provide evidence to support interventions for improving sleep quality. Methods: From April to June 2024, a survey was conducted among 4 232 fourth and fifthgrade students from nine primary schools in a district of Beijing. A selfdesigned questionnaire assessed bedtime screen use behavior and sleep health indicators. Generalized linear models and Logistic regression were used to analyze the associations. Results: Among the surveyed students, 28.3% reported bedtime screen use. Mean sleep duration every day was (9.31±0.90) hours on school days and (10.08±1.36) hours on weekends. Compared to nonusers, students with bedtime screen use exhibited every day: later bedtimes on school days (10.18 min delay, 95%CI=6.88-13.47) and weekends (22.09 min delay, 95%CI=17.33-26.85) (P<0.05); later weekend wake times (7.97 min delay, 95%CI=1.78-14.16, P<0.05); reduced sleep duration on school days (-9.82 min, 95%CI=-13.62 to -6.03) and weekends (-14.12 min, 95%CI=-20.24 to -8.00) (P<0.05); greater weekend-school day bedtime discrepancy (β=1.15, 95%CI=1.08-1.23, P<0.01). Additionally, they had lower odds of falling asleep within 20 minutes (OR=0.62, 95%CI=0.54-0.72), daytime alertness (OR=0.66, 95%CI=0.56-0.77), and subjective sleep satisfaction (OR=0.57, 95%CI=0.49-0.66)(P<0.01). Conclusions Bedtime screen use is associated with adverse effects on multiple dimensions of sleep health in primary school students. Reducing screen exposure before bed may help improve their sleep quality.

Objective: This study explored the regulatory effects of QiShen Yiqi Dropping Pills (QSYQ) on chronic heart failure (CHF) in rats and their related mechanisms based on the gut microbiota and reactive oxygen species (ROS)/thioredoxin interacting protein (TXNIP)/NOD-like receptor protein 3 (NLRP3) signaling pathway. Methods: Sixty-five SPF-grade male SD rats were used to establish a CHF model through subcutaneous multiple injections of isoproterenol (ISO) combined with exhaustion and food control methods. The modeled rats were randomly divided into model, captopril (5.30 mg/kg), and QSYQ low-, medium-, and high-dose groups (0.08, 0.16, and 0.32 g/kg, respectively), with 11 rats per group, plus a blank group of seven rats. The medication groups were given corresponding drugs by gavage, whereas the blank and model groups were administered an equivalent volume of purified water continuously for four weeks. Rat heart function was assessed via transthoracic echocardiography, and myocardial tissue pathology changes were observed through hematoxylin and eosin staining. Serum levels of brain natriuretic peptide (BNP), lipopolysaccharide (LPS), interleukin-18 (IL-18), and interleukin-1β (IL-1β) were measured using an enzyme-linked immunosorbent assay. Automated biochemical analyzers were used to determine creatine kinase (CK), lactate dehydrogenase (LDH), and MB isoenzyme of creatine kinase (CK-MB) content. Myocardial ROS levels were examined using flow cytometry; myocardial TXNIP and NLRP3 expression were detected using immunohistochemistry. Real-time qPCR and Western blotting were used to examine myocardial mRNA and protein expression of TXNIP, NLRP3, apoptosis-related spot-like protein (ASC), caspase-1, and IL-1β, as well as myocardial thioredoxin (Trx) and colonic tight junction proteins (zonula occludens-1, ZO-1), occludin, and claudin-5. Differences in the gut microbiota of the blank, model, and QSYQ high-dose groups were determined using high-throughput 16S rDNA sequencing. Results: Compared to the blank group, the model group exhibited significantly reduced left ventricular ejection fraction (LVEF) and left ventricular fraction shortening (LVFS) (P<0.01); increased serum BNP, LPS, IL-18, and IL-1β (P<0.01) levels; increased CK, LDH, and CK-MB (P<0.01) contents; visible myocardial tissue fibrous edema, wavy appearance, cytoplasmic loosening, round vacuolar degeneration, local tissue fibrous dissolution replaced by proliferative connective tissue, accompanied by inflammatory cell infiltration; significantly increased myocardial ROS levels (P<0.01); and significantly increased myocardial TXNIP and NLRP3 expression (P<0.01). TXNIP, NLRP3, ASC, caspase-1, and IL-1β mRNA and protein expression were significantly increased (P<0.05, P<0.01, respectively), whereas Trx, ZO-1, occludin, and claudin-5 expression was significantly decreased (P<0.01). Compared to the model group, the QSYQ high-dose group showed the most significant changes (P<0.05, P<0.01), with significant increases in LVEF and LVFS (P<0.01); significant decreases in serum BNP, LPS, IL-18, and IL-1β levels (P<0.01); significant reductions in CK, LDH, and CK-MB content (P<0.01); improved myocardial tissue damage; significantly decreased myocardial ROS levels (P<0.01); and significantly reduced myocardial TXNIP and NLRP3 expression (P<0.01). TXNIP, NLRP3, ASC, caspase-1, and IL-1β mRNA and protein expression were significantly decreased (P<0.05, P<0.01), whereas Trx, ZO-1, occludin, and claudin-5 expression was significantly increased (P<0.01). 16S rDNA sequencing results confirmed that the gut microbiota of rats changed after modeling and drug intervention, with significant differences in both α- and β-diversity. Compared to the blank group, at the family level, the abundance of Oscillospiraceae decreased (P<0.05), whereas the abundance of Lactobacillaceae increased. At the species level, the abundance of Segatella copri and Treponema succinifaciens increased, whereas the abundance of Kineothrix alysoides (P<0.05), Ruminococcus callidus, and Prevotellamassilia timonensis decreased. Compared to the model group, at the family level, the abundance of Oscillospiraceae increased (P<0.05) in the QSYQ high-dose group, whereas the abundance of Lactobacillaceae decreased. At the species level, the abundance of Segatella copri and Treponema succinifaciens decreased, whereas the abundance of Kineothrix alysoides increased (P<0.05). Conclusion QSYQ can regulate the relative abundance of symbiotic bacteria Kineothrix alysoides in the intestines, reduce serum LPS levels, inhibit the ROS/TXNIP/NLRP3 signaling pathway, and improve inflammatory responses, thereby exerting therapeutic effects on CHF.

To investigate the prevalence and associated factors of fall risk among Chinese older adults, and to examine the roles of urban-rural differences, regional disparities, physical health status, and psychosocial factors in falls among this population, thereby providing evidence for tailored fall prevention strategies.

Based on the data from the 5^th National Physical Fitness Surveillance in China, this study aimed to explore the relationship between abnormal body weight and physical fitness levels in older adults.