1.Does Minimally Invasive Lumbar Spine Fusion Reduce Adjacent Segment Degeneration? A Matched-Pair Analysis With 8-Year Follow-up
Reuben Soh Chee CHEONG ; Yeow Boon TAN ; Wai Mun YUE ; Chang Ming GUO ; Seang Beng TAN ; William YEO ; Wongthawat LIAWRUNGRUEANG
Journal of Minimally Invasive Spine Surgery and Technique 2026;11(Suppl 1):S63-S70
Objective:
This study aimed to compare the long-term radiographic incidence of adjacent segment degeneration (ASD) following minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) versus open TLIF (O-TLIF) in a matched cohort, and to identify radiographic parameters associated with the development of kyphosis-type ASD.
Methods:
A retrospective matched-pair analysis was conducted involving 60 patients (30 MIS-TLIF and 30 O-TLIF) who underwent single-level TLIF between 2004 and 2009 and had a minimum follow-up of 8 years. Patients were matched for age (±3 years), sex, body mass index (±2 kg/m²), and operative level. Radiographic ASD was defined as greater than 50% disc-height loss, greater than 3 mm of listhesis, or greater than 10° of kyphotic change at the adjacent segment. Continuous variables were analyzed using independent-sample t-tests or Mann-Whitney U-tests, as appropriate, and categorical variables were analyzed using chi-square or Fisher exact tests, with statistical significance set at p<0.05.
Results:
The mean follow-up duration was 8.9±1.2 years. The MIS-TLIF group had a significantly shorter hospital stay than the O-TLIF group (3.4±1.7 days vs 6.0±2.3 days, p<0.001). Radiographic ASD occurred significantly less frequently in the MIS-TLIF group at 2 years (3.3% vs. 23.3%, p=0.023), but no significant difference was observed at ≥8 years of follow-up (43.3% vs. 50.0%, p=0.605). An increased Cobb angle at the superior adjacent level was significantly associated with kyphosis-type ASD (p=0.017). No demographic characteristics or preoperative magnetic resonance imaging parameters were found to predict ASD occurrence.
Conclusion
MIS-TLIF demonstrated an early radiographic advantage in reducing ASD compared with O-TLIF; however, this advantage diminished over time. Long-term ASD appears to be multifactorial, with sagittal imbalance playing a more prominent role in the progression of kyphosis-type ASD than the surgical approach itself.
2.Mechanism of Polygonum cuspidatum in alleviating silicosis based on network pharmacology, molecular docking, and experimental validation
Anning YANG ; Wenyan YANG ; Rui BAO ; Shengpeng WEN ; Huning ZHANG ; Sirong CHANG ; Wenyue ZHANG ; Xiaoyu LUO ; Yue SUN
China Occupational Medicine 2026;53(1):8-16
Objective To explore the potential mechanism of Polygonum cuspidatum in alleviating silicosis using network pharmacology, molecular docking, and experimental validation. Methods i) The targets of active components of Polygonum cuspidatum and silicosis-related targets were retrieved from multiple databases. The overlapping targets were imported into Venny2.1.0 and STRING platforms. "Polygonum cuspidatum-active components-potential therapeutic targets for silicosis" network was constructed and core targets of Polygonum cuspidatum that can alleviate silicosis were identified using the Cytoscape3.10.2 software. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed using the DAVID database, and molecular docking was conducted with AutoDock software. ii) Human embryonic lung fibroblast MRC-5 cells were divided into three groups. Cells in the control group were cultured in high-glucose Dulbecco's modified Eagle's medium containing 10.00% (V/V)fetal bovine serum. Cells in the silica group were treated with silica suspension at a final concentration of 150 μg·cm² (equivalent to 75 mg/L) for 48 hours. Cells in the silica + β-sitosterol group were first treated with silica suspension for 24 hours, then were cultured in medium containing β-sitosterol at a mass concentration of 50 μg/L for another 24 hours. Immunofluorescence assay and Western blotting were used to detect the effects of β-sitosterol, a core component of Polygonum cuspidatum, on the expression of phosphorylated protein kinase B (p-AKT), B-cell lymphoma-2 (BCL-2), and α-smooth muscle actin (α-SMA) in cells. Results i) A total of ten main active components of Polygonum cuspidatum, 840 targets of the active components, and 231 potential therapeutic targets for silicosis were screened through retrieval. A total of 10 core therapeutic targets were further screened, including tumor protein p53, serine/threonine protein kinase B1 (AKT1), heat shock protein 90-α, interleukin (IL)-6 , tumor necrosis factor, Src tyrosine kinase, estrogen receptor 1, epidermal growth factor receptor, BCL-2, and IL-1β. KEGG enrichment analysis yielded 178 related target pathways, among which, the phosphatidylinositol 3-kinase-protein kinase B (PI3K/AKT) signaling pathway was most relevant to silicosis. Molecular docking results showed that the top five compounds of Polygonum cuspidatum with high degree centrality, including quercetin, luteolin, physovenine, rhein, and β-sitosterol, had strong binding affinities with core targets. Among them, β-sitosterol, a key component of Polygonum cuspidatum, ranked high in binding affinity to all core targets. Molecular docking visualization indicated that β-sitosterol ranked high in binding affinitiy with the core target proteins AKT1 and BCL-2. ii) Both immunofluorescence and Western blotting results showed that, the relative expression of p-AKT, BCL-2, and α-SMA proteins increased in MRC-5 cells of the silica group compared with the control group (all P<0.05), except for p-AKT detected by Western blotting. Compared with the silica group, the relative expression levels of p-AKT, BCL-2, and α-SMA proteins in the silica+β-sitosterol group decreased (all P<0.05). Conclusion β-sitosterol, the core component of Polygonum cuspidatum, may alleviate silicosis fibrosis via the PI3K/AKT signaling pathway.
3.Predictive value of bladder deformation index for upper urinary tract damage in neurogenic bladder patients
Ran CHANG ; Huafang JING ; Yi GAO ; Siyu ZHANG ; Yue WANG ; Juan WU
Chinese Journal of Rehabilitation Theory and Practice 2025;31(2):231-234
ObjectiveTo assess the predictive value of the bladder deformation index (BDI) in determining upper urinary tract (UUT) damage among patients with neurogenic bladder (NB). MethodsClinical data of 132 NB patients admitted to Beijing Bo'ai Hospital from January, 2015 to December, 2018 were retrospectively analyzed. Patients were divided into UUT damage group and normal UUT group according to the presence or absence of hydronephrosis. The demographics, biochemical parameters and video-urodynamics (VUDS) findings were collected, and BDI was calculated. Receiver operating characteristic (ROC) curves were utilized to evaluate the predictive capability. ResultsThere were 54 patients in UUT damage group and 33 in normal UUT group. The course of disease, creatinine level and BDI were siginificantly different between two groups (P < 0.05), while the area under the curve were 0.686, 0.836 and 0.928, respectively. ConclusionCourse of disease, creatinine level and BDI are associated with UUT damage in NB patients, and BDI demonstrates the highest sensitivity and specificity, which may play a role in diagnosis of UUT damage.
4.Clinical Efficacy of Modified Huangqi Chifengtang in Treatment of IgA Nephropathy Patients and Exploration of Dose-effect Relationship of Astragali Radix
Xiujie SHI ; Meiying CHANG ; Yue SHI ; Ziyan ZHANG ; Yifan ZHANG ; Qi ZHANG ; Hangyu DUAN ; Jing LIU ; Mingming ZHAO ; Yuan SI ; Yu ZHANG
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(2):9-16
ObjectiveTo explore the dose-effect relationship and safety of high, medium, and low doses of raw Astragali Radix in the modified Huangqi Chifengtang (MHCD) for treating proteinuria in immunoglobulin A (IgA) nephropathy, and to provide scientific evidence for the clinical use of high-dose Astragali Radix in the treatment of proteinuria in IgA nephropathy. MethodsA total of 120 patients with IgA nephropathy, diagnosed with Qi deficiency and blood stasis combined with wind pathogen and heat toxicity, were randomly divided into a control group and three treatment groups. The control group received telmisartan combined with a Chinese medicine placebo, while the treatment groups were given telmisartan combined with MHCD containing different doses of raw Astragali Radix (60, 30, 15 g). Each group contained 30 patients, and the treatment period was 12 weeks. Changes in 24-hour urinary protein (24 hUTP), traditional Chinese medicine (TCM) syndrome scores, effective rate, and renal function were observed before and after treatment. Safety was assessed by monitoring liver function and blood routine. ResultsAfter 12 weeks of treatment, 24 hUTP significantly decreased in the high, medium, and low-dose groups, as well as the control group (P<0.05, P<0.01). The TCM syndrome scores in the high, medium, and low-dose groups also significantly decreased (P<0.01). Comparisons between groups showed that the 24 hUTP in the high-dose group was significantly lower than in the medium, low-dose, and control groups (P<0.05, P<0.01), and the 24 hUTP in the medium-dose group was significantly lower than in the control group (P<0.05). The TCM syndrome scores in the high and medium-dose groups were significantly lower than in the low-dose and control groups (P<0.05, P<0.01). The total effective rates for proteinuria in the high, medium, low-dose, and control groups were 92.59% (25/27), 85.19% (23/27), 60.71% (17/28), and 57.14% (16/28), respectively. The effective rates in the high and medium-dose groups were significantly higher than in the low-dose and control groups (χ2=13.185, P<0.05, P<0.01). The effective rates for TCM syndrome scores in the high, medium, low-dose, and control groups were 88.89% (24/27), 81.48% (22/27), 71.43% (20/28), and 46.43% (13/28), respectively. The efficacy of TCM syndrome scores in the high and medium-dose groups was significantly higher than in the control group (χ2=14.053, P<0.01). Compared with pre-treatment values, there was no statistically significant difference in eGFR and serum creatinine in the high and medium-dose groups. However, eGFR significantly decreased in the low-dose and control groups after treatment (P<0.05), and serum creatinine levels increased significantly in the control group (P<0.05). No statistically significant differences were observed in urea nitrogen, uric acid, albumin, total cholesterol, triglycerides, liver function, and blood routine before and after treatment in any group. ConclusionThere is a dose-effect relationship in the treatment of IgA nephropathy with high, medium, and low doses of raw Astragali Radix in MHCD. The high-dose group exhibited the best therapeutic effect and good safety profile.
5.Analysis of risk factors for MRI invisible prostate cancer
Yushi HOU ; Mingyu CHANG ; Ruiyu YUE ; Jian SONG ; Xuanhao LI ; Jingcheng LYU ; Yichen ZHU ; Boyu YANG
International Journal of Surgery 2025;52(2):98-108
Objective:To investigate the risk factors for detecting clinically significant prostate cancer (CSPCa) in patients with Prostate Imaging Reporting and Data System (PI-RADS) score≤3 on multi-parameter magnetic resonance imaging (mpMRI).Methods:Retrospective analysis was performed on the case data of 335 patients with suspected prostate cancer and PI-RADS score ≤3 who were admitted to Beijing Friendship Hospital, Capital Medical University from January 2013 to October 2022. All patients underwent 24-needle prostate biopsy. Clinical data such as age, body mass index, past medical history, serological laboratory indicators, and mpMRI imaging data were collected. The patients were grouped according to whether the puncture pathology was CSPCa or not, and the differences in clinical data between the two groups were analyzed by t-test, rank sum test and Chi-test. Multivariate Logistic regression analysis was further used to determine independent risk factors for MRI invisible prostate cancer, and receiver operating characteristics (ROC) curves were drawn. At the same time, further subgroup analysis was conducted based on whether prostate-specific antigen (PSA) was positive before puncture and PI-RADS score, respectively, and the same statistical method was used to further determine the influence of different serological indicators and PI-RADS score on the analysis results of risk factors. Results:Among all patients, 81 were CSPCa patients and 254 were non-CSPCa patients. Multivariate Logistic regression analysis showed that prostate-specific antigen density (PSAD) and PI-RADS score of 3 were independent risk factors for MRI invisible prostate cancer. At the same time, compared with suspected lesions located only in the transitional zone, the incidence of CSPCa in patients with suspected lesions located in the peripheral zone would increase, and the incidence of CSPCa would further increase when suspected lesions were found in both the transitional zone and the peripheral zone. In PSA-negative patients, only suspected lesion location was an independent risk factor for MRI invisible prostate cancer, while in PSA-positive patients, prostate volume, PSAD, and PI-RADS scores were independent risk factors. In subgroup analysis with different PI-RADS scores, suspicious lesions in both the transitional zone and peripheral zone indicate a higher likelihood of CSPCa. For patients with PI-RADS scores of 1 to 2, suspicious lesions in the peripheral zone alone may also indicated CSPCa, while for patients with PI-RADS scores of 3, the lower free prostate-specific antigen/total prostate-specific anti-principle was more accurate in predicting CSPCa.Conclusions:For patients who are clinically suspected of prostate cancer but whose PI-RADS score is less than or equal to 3 points indicated by mpMRI, it is necessary to further focus on the results of different serological indicators according to whether their PSA is positive and PI-RADS score respectively to judge whether patients should receive systemic prostate puncture, instead of using PSA level as a single indication for puncture. At the same time, clinicians should also pay full attention to the location of suspected lesions, when they are located in the peripheral zone, or there are suspected lesions in both the peripheral zone and the transitional zone, the possibility of CSPCa should be fully considered.
6.Prognostic value of mitochondrial MT-ND family genes in cancer based on a pan-cancer analysis
Hai-jia ZHANG ; Si CHEN ; Cheng CHANG ; Kai-yue GAO ; Li-jie WANG
Journal of Regional Anatomy and Operative Surgery 2025;34(5):395-400
Objective To explore the abnormal expression of the MT-ND family in pan-cancers and its prognostic value.Methods Transcriptome expression and clinical data of 33 cancers were downloaded from the TCGA database,thereby analyzing the expression differences of the MT-ND family in tissuesof different types of cancers and normal tissues.The prognostic role of the MT-ND family in pan-cancers was explored by univariate Cox regression analysis and Kaplan-Meier survival analysis.Results The expression of the MT-ND family was upregulated in the kidney chromophobe,acute myeloid leukemia and thymoma,and downregulated in the remaining tumors.The expression of the MT-ND family was associated with the overall survival rate of different types of cancers.In addition,the MT-ND family were significantly correlated with the immune invasion subtypes,and were correlated with stromal cell invasion and tumor cell stemness to varying degrees.The expression of MT-ND4 was downregulated in brain lower grade glioma,which was a protective factor for prognosis;while the expression of MT-ND4 in thymoma was upregulated,which was a risk factor for prognosis.Conclusion Pan-cancer analysis has confirmed that the MT-ND family can predict the tumor prognosis,which provides new ideas and strategies for the precision treatment and prognostic management of cancer.
7.Salvianolic acid C alleviates cuproptosis and inflammatory injury in cardiomyocytes after myocardial infarction via activating Nrf2/HO-1 signaling pathway
Jinjin CHANG ; Yanfeng YUE ; Zhuo ZHAO
Chinese Journal of Pharmacology and Toxicology 2025;39(5):332-342
OBJECTIVE To investigate the regulatory effects of salvianolic acid C(SAC)on the level of cuproptosis and inflammatory injury in cardiomyocytes after myocardial infarction(MI).METHODS①C57BL/6 mice were divided into a sham group,an MI model group,and SAC(5,10 and 20 mg·kg-1)groups,with 10 mice in each group.Mice in the SAC groups were pretreated with oral gavage of SAC for 1 week,while those in the sham and model groups received an equal volume of saline.One week later,an MI model was established in the model and SAC groups by ligating the left anterior descending coronary artery,while the sham group underwent thoracotomy without ligation.MI size was assessed using triphenyltetrazolium chloride(TTC)staining.Cardiomyocyte apoptosis was evaluated by TUNEL staining.The ultrastructure of cardiomyocyte mitochondria was observed under a transmission electron microscope.② Mouse cardiomyocytes HL-1 were divided into a control group,an oxygen-glucose deprivation(OGD)model group,OGD+SAC 1,5 and 10 μmol·L-1 groups,and a OGD+SAC(5 μmol·L-1)+nuclear factor erythroid 2-related factor 2(Nrf2)inhibitor ML385(2 μmol·L-1)group.Cells in the OGD+SAC groups were pretreated with SAC for 24 h while those in the OGD+SAC+ML385 group were pretreated with both SAC 5 μmol·L-1 and ML385 2 μmol·L-1 for 24 h.Except for the control group,an OGD model was established in HL-1 cells.ELISA was used to detect the levels of tumor necrosis factor-α(TNF-α),interleukin-6(IL-6)and IL-1β in mouse serum and HL-1 cell culture supernatants.The Cu+detection kit was used to measure Cu+levels in myocardial tissue and HL-1 cells.Cell viability was assessed using the CCK-8 kit.Apoptosis rates of HL-1 cells were detected by flow cytometry.Reactive oxygen species(ROS)levels in HL-1 cells were measured using a ROS detection kit.Western blotting analysis was performed to detect the expression levels of Nrf2,heme oxygenase-1(HO-1),and cupro-ptosis markers,ferredoxin 1(FDX1)and solute carrier family 31 member 1(SLC31A1)in myocardial tissue and HL-1 cells.RESLUTS ① Compared with the sham group,the MI model group exhibited increased myocardial infarction size,elevated cardiomyocyte apoptosis rates,mitochondrial swelling,vacuolation,and cristae rupture in cardiomyocytes,increased serum levels of TNF-α,IL-6,and IL-1β,elevated Cu+levels and expressions of FDX1 and SLC31A1 in myocardial tissue,and decreased expressions of Nrf2 and HO-1(P<0.01).Compared with the model group,the SAC 5,10 and 20 mg·kg-1 groups showed reduced MI size,decreased cardiomyocyte apoptosis rates,alleviated mitochondrial swelling,vacuola-tion,and cristae rupture,lower serum levels of TNF-α,IL-6 and IL-1β,decreased Cu+levels and expres-sions of FDX1 and SLC31A1 in myocardial tissue,and increased expressions of Nrf2 and HO-1(P<0.05,P<0.01).② Compared with the cell control group,the OGD model group demonstrated signifi-cantly decreased HL-1 cell viability,increased cell apoptosis rates,Cu+and ROS levels,expressions of FDX1 and SLC31A1,elevated levels of TNF-α,IL-6 and IL-1β in cell culture supernatants,and decreased expressions of Nrf2 and HO-1(P<0.01).Compared with the OGD model group,the SAC 1,5 and 10 μmol·L-1 groups showed increased HL-1 cell viability,decreased cell apoptosis rates,Cu+and ROS levels,expressions of FDX1 and SLC31A1,reduced levels of TNF-α,IL-6 and IL-1β in cell culture supernatants,and increased expressions of Nrf2 and HO-1(P<0.05,P<0.01).Compared with the SAC 5 μmol·L-1 group,the SAC 5 μmol·L-1+ML385 2 μmol·L-1 group exhibited decreased cell viability,increased cell apoptosis rates,Cu+and ROS levels,expressions of FDX1 and SLC31A1,elevated levels of TNF-α,IL-6,and IL-1β in cell culture supernatants,and decreased expressions of Nrf2 and HO-1(P<0.01).CONSLUSION SAC can activate the Nrf2/HO-1 signaling pathway,alleviate cuproptosis in cardiomyocytes after MI,and reduces inflammatory damage.
8.Studies on the Design and Activity of Anticancer Peptides Based on the Weak Acidic Microenvironment of Tumors
Yue-Qi NIE ; Miao JIANG ; Hui-Yan WU ; Chang-Hao DING ; Wei REN ; Jun-Yi CHANG ; Ke CHEN ; Shao-Long DU ; Peng ZHANG ; Zhong-Hua LIU
Chinese Journal of Biochemistry and Molecular Biology 2025;41(10):1380-1391
Lung cancer poses a serious threat to global public health security.Chemotherapy,as the main strategy for cancer treatment,faces challenges such as high toxicity and drug resistance.Anticancer peptides have the potential of being developed into new anticancer drugs due to their advantages of broad-spectrum anticancer activity,rapid action,and difficulty in generating drug resistance,but they also face shortcomings such as weak activity and strong toxic side effects.The weakly acidic microenvironment of tumors(pH 6.5-6.8)provides a good idea for the design of anticancer peptides of high-efficiency and low-toxicity.Previously,we designed the acid-sensitive antibacterial peptide pHly-1 using the wolf spider(Lycosa singoriensis)toxin Lycosin-Ⅰ as a template.In this study,we found that pHly-1 also had acid-sensitive anticancer activity.Further alanine scanning analysis of pHly-1 was carried out,and we ob-tained a mutant pHTP-2 with better acid sensitivity,whose IC50(half maximal inhibitory concentration)against A549 cells was 15.68 μmol/L at pH 6.6 and was greater than 100 μmol/L at pH 7.4.At pH 6.6,pHTP-2 could act on various lung cancer cell lines and induce the death of A549 cells by rapid ly-sis;at pH 7.4,500 μmol/L pHTP-2 had weak toxicity to red blood cells(the hemolysis rate was ap-proximately 38%)and primary myocardial cells(the inhibition rate was 49.7%,with P<0.05).Analy-sis of its charge,particle size,morphology,and secondary structure showed that at pH 6.6,the histidine in the sequence of pHTP-2 was protonated,increasing the positive charge(P<0.01),decreasing the hy-drated particle size(P<0.05)and forming an α-helical structure to induce membrane lysis of A549 cells.At pH 7.4,it was deprotonated,the positive charge decreases,a β-sheet structure was formed and self-aggregation occurred,limiting its effect on the A549 cell membrane and showing weak activity.In summary,pHTP-2 could respond to the weakly acidic microenvironment of tumors to exert selective cyto-toxic activity,effectively overcoming the shortcomings of anticancer peptides such as low efficiency and high toxicity.Our findings suggest that it is a high-quality lead molecule for anticancer drugs.
9.Role and mechanism of allopurinol in restoring abnormal metabolism of kynurenine to alleviate ulcerative colitis in mice
Yue-lan CHEN ; Wei-bo DONG ; He-peng XU ; Shang-xue YAN ; Wei WEI ; Yan CHANG
Chinese Pharmacological Bulletin 2025;41(5):830-836
Aim To investigate the role and mecha-nism of allopurinol(ALLO)in restoring the abnormal metabolism of kynurenine(Kyn)mediated by trypto-phan-2,3-dioxygenase 2(TDO2)to ameliorate ulcera-tive colitis(UC)in mice,and to provide experimental basis for the treatment of UC by ALLO.Methods A dextran sodium sulfate(DSS)-induced mouse UC mod-el was established,and the mice were randomly divided into the control group,the model group,the ALLO low,medium and high-dose groups(10,20,and 40 mg·kg-1),and the positive-significant salazosulfapyridine(SASP)(200 mg·kg-1)group.The body mass and disease activity index(DAI)scores of mice were re-corded;HE staining was performed to observe the de-gree of pathological damage in colon tissue;Western blot was performed to detect TDO2 protein expression in colon tissue;flow cytometry was performed to detect changes in the proportion of macrophages in spleen and mesenteric lymph nodes;ELISA was employed to de-tect the levels of TNF-α,IL-1β and IL-6 pro-inflamma-tory cytokines in the supernatant of colon tissue homog-enate;high performance liquid chromatography(HPLC)was used to detect the levels of tryptophan(Trp)and Kyn in the supernatant of colon tissue ho-mogenate.Results Compared with the model group,ALLO administration significantly ameliorated colonic histopathological injury in UC mice,decreased the pro-portion of macrophages in spleen and mesenteric lymph nodes,down-regulated the levels of TNF-α,IL-1 β,and IL-6 pro-inflammatory factors in serum of homogenate of colonic tissues,and inhibited the activity(Kyn/Trp ratio)and expression of TDO2 in colonic tissues.Con-clusion ALLO improves disease manifestations in mice with ulcerative colitis,which may be related to its restoration of abnormal Kyn metabolism.
10.Structural and Spatial Analysis of The Recognition Relationship Between Influenza A Virus Neuraminidase Antigenic Epitopes and Antibodies
Zheng ZHU ; Zheng-Shan CHEN ; Guan-Ying ZHANG ; Ting FANG ; Pu FAN ; Lei BI ; Yue CUI ; Ze-Ya LI ; Chun-Yi SU ; Xiang-Yang CHI ; Chang-Ming YU
Progress in Biochemistry and Biophysics 2025;52(4):957-969
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.

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