ObjectiveTo investigate the mechanism of topical treatment of allergic contact dermatitis （ACD） mice with Portulacae Herba based on the nuclear factor E₂-related factor 2 （Nrf2）/heme oxygenase-1 （HO-1）/nuclear factor-κB （NF-κB） signaling pathway. MethodsA total of 70 6-week-old specific pathogen free （SPF） female Kunming mice were adaptively fed for 1 week and randomly divided into blank group， model group， compound dexamethasone acetate cream group （2.075×10^-2 g·g^-1）， blank matrix cream group， low-dose Portulacae Herba cream group （0.1 g·g^-1）， high-dose Portulacae Herba cream group （0.2 g·g^-1）， and Portulacae Herba + inhibitor group （0.2 g·g^-1 + 30 mg·kg^-1 ML385）， with 10 mice in each group. One day before the experiment， the mice were shaved on the neck and back. Except for the blank group， the mice in the other groups were treated with 2，4-dinitrochlorobenzene （DNCB） to establish an ACD model. After respective administration， the skin lesion of the mice was scored， and the histopathological changes of the skin were stained with hematoxylin-eosin （HE）. Enzyme-linked immunosorbent assay （ELISA） was used to detect the levels of interleukin-6 （IL-6）， interleukin-1β （IL-1β）， reactive oxygen species （ROS）， superoxide dismutase （SOD） activity， and malondialdehyde （MDA） in serum of mice. The expression of Nrf2/HO-1/NF-κB signaling pathway-related proteins in mouse skin tissue was detected by immunohistochemistry （IHC）， Western blot， and real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）. ResultsCompared with the blank group， the mice in the model group had an increased skin lesion score （P<0.01）， severe pathological damage to skin tissue， increased content of IL-1β， IL-6， ROS， and MDA in their serum （P<0.01）， and decreased content of SOD （P<0.01）. In addition， the mRNA and protein expression levels of Nrf2， HO-1， and nuclear factor-κB inhibitor α （IκBα） in skin tissue were up-regulated （P<0.01）， while the protein expression levels of phosphorylated （p）-IκBα and p-NF-κB p65 and the mRNA expression of NF-κB p65 were down-regulated （P<0.01）. Compared with the model group and the blank matrix cream group， the mice treated with Portulacae Herba had a decreased skin lesion score （P<0.01）， reduced pathological damage to skin tissue， decreased content of IL-1β， IL-6， ROS， and MDA in their serum （P<0.01）， and increased content of SOD （P<0.01）. Additionally， the mRNA and protein expression levels of Nrf2， HO-1， and IκBα in skin tissue were down-regulated （P<0.05，P<0.01）， and the protein expression levels of p-IκBα and p-NF-κB p65 and the mRNA expression of NF-κB p65 were up-regulated （P<0.05，P<0.01）. Compared with the Portulacae Herba + inhibitor group， the high-dose Portulacae Herba cream group had a decreased skin lesion score （P<0.01）， alleviated pathological damage to skin tissue， decreased content of IL-1β， IL-6， ROS， and MDA in the serum of mice （P<0.05，P<0.01）， and increased content of SOD （P<0.01）. The protein expression levels of Nrf2， HO-1， and IκBα and the mRNA expression of Nrf2 and HO-1 in skin tissue were up-regulated （P<0.05，P<0.01）， and the protein expression levels of p-IκBα and p-NF-κB p65 and the mRNA expression of NF-κB p65 were down-regulated （P<0.05）. ConclusionPortulacae Herba can improve DNCB-induced ACD skin damage in mice by regulating the Nrf2/HO-1/NF-κB signaling pathway.

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.

BACKGROUND:Studies have shown that metformin has anti-inflammatory,anti-tumor,anti-aging and vasoprotective effects,and can inhibit the progression of osteoarthritis,but its specific mechanism of action remains unclear. OBJECTIVE:To investigate the mechanism of metformin on cartilage protection in a rat model of osteoarthritis. METHODS:Forty male Sprague-Dawley rats were randomly divided into four groups(n=10 per group):blank,control,sham-operated,and metformin groups.The blank group did not undergo any surgery.In the sham-operated group,the joint cavity was exposed.In the model group and the metformin group,the modified Hulth method was used to establish the osteoarthritis model.At 1 day after modeling,the rats in the metformin group were given 200 mg/kg/d metformin by gavage,and the model,blank,and sham-operated groups were given normal saline by gavage.Administration in each group was given for 4 weeks consecutively.Hematoxylin-eosin staining,toluidine blue staining,and safranin O-fast green staining were used to observe the morphological structure of rat knee joints.Immunohistochemical staining and western blot were used to detect the protein expression of SOX9,type Ⅱ collagen,a disintegrin and metalloproteinase with thrombospondin motifs 5(ADAMTS5),Beclin1,P62,phosphatidylinositol 3-kinase(PI3K),p-PI3K,protein kinase B(AKT),p-AKT,mammalian target of rapamycin(Mtor),and p-Mtor in rat cartilage tissue. RESULTS AND CONCLUSION:The results of hematoxylin-eosin,toluidine blue and safranin O-fast green staining showed smooth cartilage surface of the knee joints and normal histomorphology in the blank group and the sham-operated group,while in the model group,there was irregular cartilage surface of the knee joint and cartilage damage,with a decrease in the number of chondrocytes and the content of proteoglycans in the cartilage matrix.In the metformin group,there was a significant improvement in the damage to the structure of the cartilage in the knee joints of the rats,and the cartilage surface tended to be smooth,with an increase in the number of chondrocytes and the content of proteoglycans in the cartilage matrix.Immunohistochemistry staining and western blot results showed that compared with the control and sham-operated groups,the expression of SOX9,type Ⅱ collagen,and Beclin1 proteins in the cartilage tissue of rats in the model group was significantly decreased(P<0.05).Conversely,the expression of ADAMTS5,P62,as well as p-PI3K,p-AKT,and p-Mtor proteins was significantly increased(P<0.05).Furthermore,compared with the model group,the expression of SOX9,type Ⅱ collagen,and Beclin1 proteins in the cartilage tissue of rats in the metformin group was significantly increased(P<0.05),while the expression of ADAMTS5,P62,as well as p-PI3K,p-AKT,and p-Mtor proteins was significantly decreased(P<0.05).To conclude,Metformin can improve the autophagy activity of chondrocytes and reduce the degradation of cartilage matrix in osteoarthritis rats by inhibiting the activation of PI3K/AKT/Mtor signaling pathway,thus exerting a protective effect on articular cartilage.

This study aimed to explore the molecular mechanism of rubioncolin C(RuC) in inhibiting gastric cancer(GC). AGS and MGC803 cell lines were selected as cellular models. After treating the cells with RuC at different concentrations, the effects of RuC on the proliferation ability of GC cells were assessed using the CCK-8 method, real-time cellular analysis(RTCA), and colony formation assays. Transmission electron microscopy was used to observe subcellular structural changes. Immunofluorescence was applied to detect LC3 fluorescent foci. Acridine orange staining was used to evaluate the state of intracellular lysosomes. Western blot was employed to detect the expression of autophagy-related proteins LC3Ⅱ, P62, and lysosomal cathepsin D(CTSD). The SuperPred online tool was used to predict the target proteins that bound to RuC, and molecular docking analysis was conducted to identify the interaction sites between RuC and CTSD. The drug affinity responsive target stability(DARTS) assay was performed to detect the direct binding interaction between RuC and CTSD. The results showed that RuC significantly inhibited the proliferation and colony formation of GC cells at low concentrations, with 24-hour half-maximal inhibitory concentrations(IC_(50)) of 3.422 and 2.697 μmol·L~(-1) for AGS and MGC803 cells, respectively. After 24 hours of treatment with RuC at concentrations of 1, 2, and 3 μmol·L~(-1), the colony formation rates for AGS cells were 61.0%±1.5%, 28.0%±0.5%, and 18.2%±0.5%, respectively, while the rates for MGC803 cells were 56.0%±0.5%, 23.3%±1.0%, and 11.8%±1.0%, all of which were significantly reduced. Transmission electron microscopy revealed that RuC promoted an increase in autophagosome formation in GC cells. Immunofluorescence detection showed that LC3 fluorescent foci of GC cells increased with the increase in RuC dose. RuC up-regulated the expression of autophagy-related proteins LC3Ⅱ and P62 in GC cells. Acridine orange staining indicated that RuC altered the acidic environment of lysosomes. SuperPred online prediction identified CTSD as a potential target protein of RuC. Western blot analysis revealed that RuC induced the up-regulation of the inactive precursor of CTSD in GC cells. CTSD activity assays indicated that RuC reduced the activity of CTSD. Molecular docking simulations found that RuC bound to the substrate-binding region of CTSD, forming hydrogen bonds with the Tyr205 and Asp231 residues. Microscale thermophoresis and DARTS assays further confirmed that RuC directly bound to CTSD. In summary, RuC inhibits lysosomal activity by targeting and down-regulating the expression of CTSD, thereby inducing autophagosome accumulation in GC cells.
Humans ; Stomach Neoplasms/enzymology* ; Cathepsin D/chemistry* ; Cell Line, Tumor ; Molecular Docking Simulation ; Cell Proliferation/drug effects* ; Autophagosomes/metabolism* ; Autophagy/drug effects*

Based on the interleukin-17(IL-17) signaling pathway, this study explores the effect and mechanism of Bufei Decoction on Klebsiella pneumoniae pneumonia in rats. SD rats were randomly divided into the control group, model group, Bufei Decoction low-dose group(6.68 g·kg~(-1)·d~(-1)), Bufei Decoction high-dose group(13.36 g·kg~(-1)·d~(-1)), and dexamethasone group(1.04 mg·kg~(-1)·d~(-1)), with 10 rats in each group. A pneumonia model was established by tracheal drip injection of K. pneumoniae. After successful model establishment, the improvement in lung tissue damage was observed following drug administration. Core targets and signaling pathways were screened using transcriptomics techniques. Real-time fluorescence quantitative polymerase chain reaction was used to detect the mRNA expression of core targets interleukin-6(IL-6), interleukin-1β(IL-1β), tumor necrosis factor-α(TNF-α), and chemokine CXC ligand 6(CXCL6). Western blot was used to assess key proteins in the IL-17 signaling pathway, including interleukin-17A(IL-17A), nuclear transcription factor-κB activator 1(Act1), tumor necrosis factor receptor-associated factor 6(TRAF6), and downstream phosphorylated p38 mitogen-activated protein kinase(p-p38 MAPK), and phosphorylated nuclear factor-κB p65(p-NF-κB p65). Apoptosis of lung tissue cells was detected by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling(TUNEL). The results showed that, compared with the control group, the model group exhibited significant pathological damage in lung tissue. The mRNA expression of IL-6, IL-1β, TNF-α, and CXCL6, as well as the protein levels of IL-17A, Act1, TRAF6, p-p38 MAPK/p38 MAPK, and p-NF-κB p65/NF-κB p65, were significantly increased, and the number of apoptotic cells was notably higher, indicating successful model establishment. Compared with the model group, both low-and high-dose groups of Bufei Decoction showed reduced pathological damage in lung tissue. The mRNA expression levels of IL-6, IL-1β, TNF-α, and CXCL6, and the protein levels of IL-17A, Act1, TRAF6, p-p38 MAPK/p38 MAPK, and p-NF-κB p65/NF-κB p65, were significantly decreased, with a significant reduction in apoptotic cells in the high-dose group. In conclusion, Bufei Decoction can effectively improve lung tissue damage and reduce inflammation in rats with K. pneumoniae. The mechanism may involve the regulation of the IL-17 signaling pathway and the reduction of apoptosis.
Animals ; Interleukin-17/metabolism* ; Drugs, Chinese Herbal/administration & dosage* ; Rats, Sprague-Dawley ; Signal Transduction/drug effects* ; Rats ; Male ; Klebsiella pneumoniae/physiology* ; Klebsiella Infections/immunology* ; Humans ; Lung/drug effects*

OBJECTIVE To study the effects and mechanism of Portulaca oleracea cream on skin pruritus and barrier function in allergic contact dermatitis （ACD） mice. METHODS Low-concentration and high-concentration P. oleracea creams were prepared， with the P. oleracea extract solution （1 g/mL， calculated by crude drug） concentrations of 10% and 20%. Sixty BALB/c mice were randomly allocated into blank group， model group， Mometasone furoate cream group （positive control）， blank matrix cream group， P. oleracea low-concentration and high-concentration cream groups. Except for blank group， ACD model was induced in each group using 2，4-dinitrochlorobenzene solution. The blank group and model groups received normal saline， while the remaining groups were treated with their respective creams， once a day， at a dose of approximately 0.5 g per application， continuously for 14 days. At 24 h post-final administration， skin lesions of mice were observed and scored； pathological changes of skin tissue were observed； serum levels of immunoglobulin E（IgE） and tumor necrosis factor-α （TNF-α） were quantified. mRNA expression of MAS-related G protein-coupled receptors （including MrgprA3， MrgprC11， and MrgprD） in dorsal root ganglion （DRG） was assessed； while protein expressions of skin barrier function-related proteins Claudin-1 and Occludin in skin tissues were determined. RESULTS Compared with blank group， mice in the model group exhibited severe skin damage， characterized by loss of epidermal architecture， hyperkeratosis of the skin tissue， and the infiltration of a large number of inflammatory cells. The skin injury scores， as well as the serum levels of IgE and TNF-α， and the mRNA expression levels of MrgprA3， MrgprC11， and MrgprD in DRG， were all significantly elevated compared to the blank group （P＜0.05 or P＜0.01）； in contrast， the protein expression levels of Claudin-1 and Occludin in the skin tissue were markedly reduced （P＜0.05）. Compared with model group， mice in P. oleracea low-concentration and high- concentration cream groups demonstrated significant alleviation of skin damage， as evidenced by reduced epidermal hyperplasia， mitigated spongiosis in the dermis， and decreased infiltration of inflammatory cells； these quantitative indicators were almost significantly reversed （P＜0.05 or P＜0.01）. No significant differences were observed in the aforementioned skin injuries， pathological alterations， or quantitative indicators between the blank matrix cream group and the model group. CONCLUSIONS P. oleracea may ameliorate skin lesions and restore skin barrier function of ACD mice， the mechanism of which may be associated with downregulating mRNA expressions of MrgprA3， MrgprC11 and MrgprD in DRG， and up-regulating the protein expressions of Claudin-1 and Occludin in skin tissue.

Background Personal protection is crucial for reducing the risk of zoonotic pathogen infection among livestock workers. Investigating the current status of its implementation and associated influencing factors can provide empirical evidence for developing more effective intervention measures. Objective To investigate the current status of personal protection implementation among livestock workers in Xinjiang, China and its influencing factors, providing a reference for formulating targeted intervention measures. Methods This study was conducted in Bayingolin Mongol Autonomous Prefecture, Kashgar region, and the First and Eighth Divisions of Xinjiang Production and Construction Corps. We selected large-scale cattle and sheep farms, cooperatives, individual livestock households, livestock trading markets, slaughterhouses, and retail markets. Using cluster sampling, we recruited all livestock workers (1074 participants) at sampled sites. During the period from April to July 2024, we conducted face-to-face surveys with a self-designed questionnaire among livestock workers, collecting general demographic information, occupational exposure history, and information related to the use of personal protective equipment, resulting in 939 valid questionnaires. EpiData 3.1 was used for data entry and SPSS 26.0 for statistical analysis. We employed logistic regression to compare the implementation of personal protection among workers by selected categories. Results Among the study subjects, there were 300 workers from large-scale farms (31.95%) and 583 self-employed livestock farmers (62.09%). The sample included 600 males (63.90%) and 339 females (36.10%). The majority of the study subjects was farmers, breeders, or aged 18-60 years (87.75%), auxiliary workers (87.97%) and had an education level of junior high school or below (81.36%). The proportion of workers who consistently and correctly implemented all five personal protective measures (washing hands after work, wearing gloves, wearing masks, wearing dedicated work clothes, and using rubber boots) was 35.14% (330/939). The implementation rates for these five protective measures were 93.61% (879/939), 58.68% (551/939), 57.93% (544/939), 46.01% (432/939), and 42.81% (402/939), respectively. There were statistically significant differences in the implementation rates of differen personal protective measures among the workers by occupation and education level (P<0.05). Among them, workers with lower education levels had lower implementation rates for various protective measures. The results of logistic regression indicated that, compared to male workers, female workers (OR=2.26, 95%CI: 1.68, 3.04) showed a higher rate of non-standard implementation of personal protection. Using the age group of 18 to less than 36 years as a reference, those aged 36 to less than 60 years (OR=1.82, 95%CI: 1.33, 2.50) and 60 years or older (OR=4.45, 95%CI: 2.56, 7.73) reported higher rates of non-standard implementation of personal protection. Compared to those with an education level of primary school or below, those with a junior high school education (OR=0.64, 95%CI: 0.47, 0.88) and a high school education or above (OR=0.13, 95%CI: 0.19, 0.29) showed lower rates of non-standard implementation of personal protection. Compared to farmers, veterinarians (OR=0.03, 95%CI: 0.02, 0.07) reported the lowest rate of non-standard implementation of personal protection, followed by auxiliary workers (OR=0.08, 95%CI: 0.05, 0.12), breeders (OR=0.10, 95%CI: 0.07, 0.15), and other occupational groups (OR=0.28, 95%CI: 0.15, 0.52). Using large-scale farms as a reference, self-employed farmers (OR=13.5, 95%CI: 9.65, 18.88) reported a higher rate of non-standard implementation of personal protection, followed by workers from other workplaces (OR=3.63, 95%CI: 2.01, 6.54). Conclusion The implementation of personal protective measures among livestock workers in Xinjiang is generally satisfactory. However, significant disparities in the execution of these measures exist among different types of workers, indicating the need to enhance occupational health promotion to reduce the risk of zoonotic pathogen infection among the workers.

Background Animal farming may affect the structure and diversity of gut microbiota of farm workers, but it needs more studies to provide solid evidence. Objective To analyze the diversity characteristics of gut microbiota in dairy farm workers, dairy cows, and the control population (non-animal contact occupational group), and to assess the impact of dairy farming on the gut microbiota of workers. Methods The 16S rRNA full-length amplicon sequencing technology was used to sequence 60 fecal samples from dairy farm workers, 89 from dairy cows, and 50 from the general population. The gut microbiota structure characteristics, including operational taxonomic units (OTUs), alpha diversity, beta diversity, and the composition of species at the phylum, family, and genus levels were analyzed. The differences in gut microbiota among the three groups of samples were compared to explore the impact of occupational exposure on the gut microbiota structure of dairy farm workers. Results A total of 50478 OTUs were identified in the gut microbiota of farm workers, dairy cows, and the general population, with 23613, 42723, and 16592 OTUs, respectively. The number of shared OTUs between the dairy cows and the general population was 12674 (27.17%), between the general population and the farm workers was 10099 (33.54%), and between the dairy cows and the farm workers was 17690 (36.36%). Compared with the general population, the farm workers and dairy cows showed more shared gut microbiota (P<0.01). The abundance of Firmicutes in the gut of the farm workers was higher than that of the general population (P<0.01), while Actinobacteriota and Proteobacteria were the opposite (P<0.01). The alpha diversity of gut microbiota in the farm workers was different from that of the general population. The ACE index of the farm workers was slightly lower than that of the general population and much lower than that of dairy cows (P<0.05), while their Shannon index was higher than that of the general population but lower than that of dairy cows (P<0.01). The linear discriminant analysis effect size (LefSe) showed that the abundances of Lachnospiraceae and Ruminococcaceae in the gut microbiota of the farm workers were significantly higher than those of the general population, while Streptococcaceae, Lactobacillaceae, Bifidobacteriaceae, Enterobacteriaceae, and Erysipelatoclostridiaceae were lower than those of the general population. Conclusion The dairy farm workers shares a certain proportion of common bacterial communities with dairy cows. Dairy farming operations can affect the structure and diversity of the gut microbiota of workers by increasing the abundances of Lachnospiraceae and Ruminococcaceae, while decreasing the abundances of Streptococcaceae, Lactobacillaceae, Bifidobacteriaceae, Enterobacteriaceae, and Erysipelatoclostridiaceae. The study results provide reference data for further exploring the cross-host transmission of pathogens related to occupational exposure in dairy farming.

ObjectiveTo explore the effect of Yishen Tongluo prescription on sperm DNA fragmentation index （DFI） and sperm mitochondrial membrane potential （MMP） in patients with asymptomatic idiopathic asthenospermia infertility. MethodsA total of 128 patients with asymptomatic idiopathic asthenospermia were randomly assigned to an experimental group （64 cases） and a control group （64 cases）. The experimental group received Yishen Tongluo prescription， while the control group was treated with Wuzi Yanzongwan combined with L-carnitine oral solution. One treatment course lasted 12 weeks. Spouse pregnancy rate， sperm progressive motility （PR）， total sperm motility （PR+NP）， sperm function （sperm tail hypotonic swelling rate， sperm acrosin activity）， sperm DFI， and sperm MMP were compared between the two groups before and after treatment. Adverse reactions were observed and recorded during the study， and clinical efficacy and safety were systematically evaluated. ResultsA total of 121 patients completed the study， including 61 in the experimental group and 60 in the control group. The spouse pregnancy rate in the experimental group was 14.75% （9/61）， higher than that in the control group at 6.67% （4/60）， though the difference was not statistically significant. Clinical efficacy in the experimental group was superior to that in the control group （P<0.05）. Compared with the results before treatment， sperm PR， PR + NP， sperm tail hypotonic swelling rate， sperm acrosin activity， sperm DFI， and sperm MMP were significantly improved in both groups after treatment （P<0.05）， with greater improvements in the experimental group （P<0.05）. However， there was no significant change in sperm concentration in either group after treatment. During the study， no abnormal safety indicators or significant adverse reactions occurred in either group. ConclusionThe kidney-tonifying and collateral-dredging method shows good clinical efficacy in the treatment of asymptomatic idiopathic asthenospermia infertility. Yishen Tongluo prescription can improve sperm motility， increase spouse pregnancy rate， enhance sperm function， and demonstrates good safety. Its mechanism may be related to reducing sperm DFI and increasing sperm MMP.

ObjectiveTo investigate the influenza virus infection status of influenza-like illness (ILI) at a sentinel hospital in Baoshan District of Shanghai, to explore the seasonal patterns of influenza, so as to provide a scientific basis for influenza prevention and control in Baoshan District of Shanghai. MethodsSurveillance data and pathogenic testing results of ILI from the monitoring year of 2015 to 2023 were collected from the sentinel hospital to describe the seasonal epidemic characteristics of influenza in this district. ResultsThe proportion of ILI visits to sentinel hospital in Baoshan District of Shanghai showed an upward trend from 2015 to 2023 (Z=2.598, P=0.09). The positive rate of influenza virus in ILI was 20.43% (1 761/8 621), of which 14.17% were positive for influenza A virus, including 8.43% for influenza A/H3N2 and 5.74% for influenza A/H1N1. The positive rate of influenza B virus was 6.25%, of which the positive detection rate of influenza B/Victoria virus was 5.35%, while that of influenza B/Yamagata virus was 0.90%. Influenza B/Yamagata virus was not detected in 2019‒2023. The highest positivity rate was observed in the 5‒<15 years age group (25.57%). The positive rate of ILI was lower in males (19.90%) than that in females (20.90%). There were three patterns of influenza epidemic in the district: with year-round circulation in 2016‒2017 and 2021‒2022; with bimodal peaks in 2015‒2016, 2017‒2018 and 2022‒2023; and with one peak in 2018‒2019 and 2019‒2020. The positive rate of influenza virus exhibited seasonal variations, with influenza A virus predominated in summer and autumn. However, influenza B virus showed an increase in spring and winter. ConclusionThe influenza epidemic in Baoshan District, Shanghai exhibits diverse patterns with heterogeneous epidemiological characteristics across different age groups and seasons. Notably, children and adolescents aged 5‒<15 years constitute the key target population for influenza prevention and control. Enhanced surveillance and targeted control measures against influenza A/H3N2 lineage viruses are particularly warranted during summer and autumn seasons.