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 study the regulatory effect of the partial sequence within the 3’ untranslated region （3’UTR） of slit guidance ligand 1 （Slit1） （Slit1-3’UTR） on the fibrotic phenotypes of cardiac fibroblasts （CFs） and its potential mechanism. MethodsThe adenovirus vector was used to overexpress the 1526nt sequence of Slit1-3’UTR in ICR neonatal mouse CFs （mCFs）. The expression of fibrosis-related genes in mCFs， such as collagen type 1 alpha1（COL1A1）， collagen type 3 alpha3 （COL3A1） and alpha smooth muscle actin （α-SMA） were detected by Western blot assay. The effect of Slit1-3’UTR 1526nt on the proliferation and migration of mCFs was assessed by EdU staining and Trans-well assays. Angiotensin Ⅱ （Ang Ⅱ） was used to treat mCFs， and the impact of Slit1-3’UTR 1526nt on the fibrotic phenotypes of Ang Ⅱ-induced mCFs was evaluated. After overexpression of Slit1-3’UTR 1526nt， miR-34a-5p mimic was transfected into mCFs， followed by actinomycin D treatment to detect the mRNA stability of Slit1-3’UTR 1526nt， and the levels of miR-34a-5p and its target gene SIRT1（si-SIRT1） in mCFs were determined. The effects of miR-34a-5p and small interfering RNA targeting SIRT1 on the Slit1-3’UTR 1526nt-mediated regulation of fibrotic phenotypes were also determined. ResultsAdenovirus-mediated overexpression of Slit 1-3’UTR 1526nt was achieved in mCFs. Overexpression of Slit 1-3’UTR 1526nt markedly inhibited the expression of the fibrosis-related genes， proliferation and migration of mCFs and fibrotic phenotypes of Ang Ⅱ. The results of actinomycin D assay showed that miR-34a-5p inhibited the stability of Slit1-3’UTR 1526nt in mCFs， while the level of miR-34a-5p was reduced in mCFs with overexpression of Slit1-3’UTR 1526nt. Transfection of miR-34a-5p promoted the fibrotic phenotypes， and reversed the inhibitory effect of Slit1-3’UTR 1526nt on the fibrotic phenotypes of mCFs. Overexpression of Slit1-3’UTR 1526nt significantly increased the level of miR-34a-5p target gene SIRT1 in mCFs. Transfection of miR-34a-5p and si-SIRT1 consistently reversed the inhibitory effects of Slit1-3’UTR 1526nt on the fibrotic phenotypes of mCFs. ConclusionSlit1-3’UTR1526nt inhibits the fibrotic phenotypes of mCFs by binding to miR-34a-5p and increasing the expression of its target gene of SIRT1.

Objective To explore the mediating role of activities of daily living (ADL) in pain and depressive symptoms in the elderly in China. Methods Utilizing the data from 2020 China Health and Retirement Longitudinal Study, 4403 Chinese elderly individuals aged ≥ 60 years old were selected as the research subjects. Depression Scale (CES-D 10) of the Center for Epidemiological Survey and ADL scale were used in the study. The PROCESS4.1 macro was used to test the mediating effect of daily living activities between pain and depressive symptoms, and the Bootstrap method was applied for verification of the mediating variables. Results A total of 2368 cases of depressive symptoms were detected in the elderly in China, with a detection rate of 53.78%. Pain was positively correlated with depressive symptoms (r=0.27, P<0.01), and activities of daily living were negatively correlated with pain and depressive symptoms (r=-0.27, -0.337, P<0.01). The results showed that the total effect value of pain on depressive symptoms was 0.33, the direct effect value was 0.24, and the mediating effect value of daily living activities was 0.09, accounting for 27.27%. Conclusion Pain and activities of daily living are important factors influencing depressive symptoms in the elderly, and activities of daily living play a partial mediating role in the relationship between pain and depressive symptoms in the elderly.

OBJECTIVES: To investigate the molecular mechanism underlying Leber hereditary optic neuropathy (LHON) caused by the m.3472T>C (p.Phe56Leu) mutation. METHODS: From a cohort of 1397 LHON patients, three large pedigrees (WZL122, WZ676, WZ706) carrying the m.3472T>C mutation were identified and selected for this study. Immortalized lymphoblastoid cell lines were established from peripheral blood samples obtained from two affected individuals carrying the homoplasmic m.3472T>C mutation (derived from one Han Chinese LHON pedigree) and two genetically unrelated, matched healthy controls. The MitoTool software was used to analyze the complete mitochondrial DNA sequence to determine the haplogroup background, and the conservation of the mtDNA mutation site was evaluated using the MitoMap database. The secondary structure of the ND1 protein was predicted and analyzed using online prediction software. The three-dimensional structure and molecular interaction changes of wild-type and mutant ND1 proteins were visualized and analyzed using PyMOL. Western blotting was performed to determine the expression levels of key proteins. Cellular ATP levels were measured using a chemiluminescence assay. Mitochondrial membrane potential and intracellular reactive oxygen species (ROS) levels were assessed by flow cytometry. RESULTS: mtDNA haplotype analysis showed that the subjects all belonged to the East Asian mitochondrial haplogroup D4. The m.3472T>C mutation results in the substitution of a highly conserved phenylalanine with leucine (p.Phe56Leu) in the ND1 subunit of mitochondrial complex Ⅰ, which may alter the structure and function of ND1. In lymphoblastoid cell lines carrying the m.3472T>C mutation, manifestations of mutant ND1 instability were observed, including reduced ND1 protein levels, diminished mitochondrial ATP production, decreased mitochondrial membrane potential, and increased mitochondrial ROS production. Concurrently, the expression levels of the antioxidant enzymes catalase and SOD2 were elevated (all P<0.01). These findings collectively suggest impaired complex Ⅰ function. CONCLUSIONS The m.3472T>C mutation contributes to the pathogenesis of LHON by disrupting the structural stability of the ND1 subunit in complex Ⅰ, leading to mitochondrial dysfunction.

Objective To identify the clinical characteristics and prognostic factors of young patients with sporadic rectal cancer liver metastasis(RCLM).Methods The clinical data of young RCLM patients at 45 years or under(n=40,as younger patient group)in Peking University First Hospital from January 2016 to January 2021 were reviewed,meanwhile,elder RCLM patient group were comprised of 82 patients older than 45-year-old in a 1:2 ratio.Proportions of categorical variables were compared between young patients and old patients.The clinicopathologic parameters were analyzed with univariate and multivariate Cox regression models and Kaplan-Meier method for demonstrating survival differences between the maximum diameter of liver metastasis and local therapy.Results One hundred and twenty-two RCLM patients were identified,the 1-,3-and 5-year survival rates of young patient group were 97.5%,47.5%,15.0%,those of elder patient group were 84.1%,26.8%,9.8%,respectively.The differences in BMI(P=0.008),primary tumor with obstruction and bleeding(P=0.006),synchronous rectal cancer liver metastases(P=0.005),the maximum diameter of liver metastasis>3 cm(P=0.019)were statistically significant between the two groups.And univariate and multivariate analyses showed that age(P=0.003),N stage(P=0.007),local therapy for liver metastases(P=0.047)and the maximum diameter of liver metastasis(P=0.030)were independent risk factors for influencing the prognosis of RCLM patients;curative resection or not of primary tumor(P=0.035)and the maximum diameter of liver metastasis(P=0.041)were independent risk factors for influencing the prognosis of young RCLM patients.Kaplan-Maier curve demonstrated survival differences between the maximum diameter of liver metastasis and local therapy for liver metastasis in RCLM patients(log-rank P=0.000).Conclusions Although with later staging of initial tumor station,young RCLM patients may obtain better survival benefit compared with old patients.Higher degree of lymph node metastasis,local therapy for liver metastases and the maximum diameter of liver metastasis>3 cm indicates poor prognosis in RCLM patients,and without curative resection of primary tumor and maximum diameter of liver metastasis are also considered as the independent poor prognostic factors of young RCLM patients.Local therapy for liver metastases appears to play an important role in the treatment strategy of RCLM patients.

Objective:To investigate the impact of QiliQiangXin Capsules on ventricular remodeling and cardiac contraction and relaxation function in aging rats with heart failure following myocardial infarction.Methods:From August 2022 to August 2023, a total of 30 old rats were randomly assigned to three groups: sham-operated group, model group, and treatment group, with 10 rats in each group selected through a digital lottery method.The model and treatment groups were created by ligating the anterior descending branch of the left coronary artery.The rats in the treatment group received daily administration of Astragalosa hebecarpa Drabanemerosa Strong Heart Capsule(1.0 g/kg)via gavage after 4 weeks.After the 4-week drug administration period, echocardiography was performed to measure various parameters including left ventricular end-diastolic internal diameter(LVIDd), left ventricular end-systolic internal diameter(LVIDs), left ventricular ejection fraction(LVEF), left ventricular anterior wall myocardial thickness(LVAWd), mitral valve early diastolic peak flow velocity(E peak), and early diastolic velocity of mitral annulus(e peak)detected by tissue Doppler(TDI). The E/e value was calculated based on these measurements.Additionally, serum levels of B-type brain natriuretic peptide(BNP), matrix metalloproteinase 2(MMP-2), matrix metalloproteinase 9(MMP-9), and tumor necrosis factor(TNF-α)were measured using enzyme-linked immunosorbent assay(ELISA). Hematoxylin-eosin(HE)staining was employed to observe the morphological changes in myocardial tissue.Results:Compared to rats in the model group, rats in the treatment group exhibited lower left ventricular internal dimension at end-diastole(LVIDd)(9.1±0.6 mm vs.11.4±0.8 mm, P<0.01), lower left ventricular internal dimension at end-systole(LVIDs)(5.9±0.8 mm vs.8.7±0.9 mm, P<0.01), lower E/e ratio(13.4±2.0 vs.16.3±2.8, P<0.05), higher left ventricular ejection fraction(LVEF)(68.8±7.1% vs.52.0±8.4%, P<0.01), and elevated left ventricular anterior wall thickness at end-diastole(LVAWd)(1.5±0.2 mm vs.1.2±0.3 mm, P<0.05). In addition, compared to rats in the model group, the treatment group showed a decrease in brain natriuretic peptide(BNP)(0.26±0.04 μg/L vs.0.34±0.05 μg/L, P<0.01), decreased matrix metalloproteinase-2(MMP-2)(3697.0±857.7 μg/L vs.4719.5±703.5 μg/L, P<0.01), decreased matrix metalloproteinase-9(MMP-9)(87.3±13.8 μg/L vs.116.5±9.6 μg/L, P<0.01), decreased tumor necrosis factor-alpha(TNF-α)(165.3±36.9 μg/L vs.269.8±35.0 μg/L, P<0.01), and lower TNF-α levels(165.3±36.9 μg/L vs.269.8±35.0 μg/L, P<0.01). Histological examination using hematoxylin and eosin(HE)staining revealed that the treatment group had less severe cardiac myocyte arrangement disorder and inflammatory reaction compared to the model group. Conclusions:Qiliqiangxin Capsules were found to effectively delay ventricular remodeling and improve myocardial contraction and relaxation function in aging rats with heart failure after acute myocardial infarction.

This study using maltodextrin as raw material, 1%-5% polyvinylpyrrolidone K30 as template agent, 1%-5% ammonium bicarbonate as pore-forming agent, curcumin and ibuprofen as model drugs. Porous maltodextrin was prepared by template and pore-forming agent methods, respectively. The structure and drug delivery behavior of porous maltodextrin prepared by different technologies were comprehensively characterized. The results showed that the porous maltodextrin prepared by pore-forming agent method had larger specific surface area (6.449 4 m²·g^-1) and pore size (32.804 2 nm), which was significantly better than that by template agent method (3.670 2 m²·g^-1, 15.278 5 nm). The adsorption kinetics between porous maltodextrin prepared by pore-forming agent method and curcumin were suitable for quasi-first order adsorption kinetic model, and that between porous maltodextrin and ibuprofen were suitable for quasi-second order adsorption kinetic model. While the adsorption kinetics between porous maltodextrin prepared by template agent method and two model drugs were both suitable for the quasi-first order adsorption kinetic model. In addition, the dissolution behavior analysis showed that the porous maltodextrin prepared by the two technologies can significantly improve the dissolution behavior of insoluble drugs, and the drug release was both carried out by diffusion mechanism, which suitable for the Peppas kinetic release model, but the porous maltodextrin prepared by template agent method had a faster release rate. The change of nozzle diameter had no significant effect on the adsorption process and drug release behavior of porous maltodextrin. In conclusion, the porous maltodextrins prepared by two different technologies were both beneficial to the delivery of insoluble drugs, and the template agent method was the best for delivery of insoluble drugs. This study can provide theoretical basis for the preparation of porous particles, promote the application of porous particles in insoluble drugs, and improve the bioavailability of insoluble drugs.

Objective:To evaluate the effect of neoadjuvant chemotherapy combined with immunotherapy on the perioperative renal function in patients undergoing radical resection for esophageal cancer.Methods:This was a retrospective cohort study. Clinical data from patients undergoing neoadjuvant chemotherapy combined with immunotherapy for esophageal cancer in Tianjin Medical University Cancer Institute & Hospital and Tianjin University Chest Hospital from January 2020 to April 2022 were retrospectively collected. According to the preoperative treatment regimen, the patients were divided into neoadjuvant chemotherapy group (group nCT) and neoadjuvant chemotherapy combined with immunotherapy group (group nCT+ IT). nCT group underwent neoadjuvant chemotherapy, which included a platinum-based regimen combined with fluorouracil or taxanes. In nCIT+ IT group, programmed cell death protein 1 inhibitors were used for immunotherapy based on neoadjuvant chemotherapy. All the patients underwent 2-3 cycles of therapy, with each cycle lasting 21 days. Surgery was performed 4-6 weeks after the completion of the last therapy. The concentrations of serum creatinine, uric acid and blood urea nitrogen were detected before therapy, at 72 h before surgery and at 72 h after surgery. The acute kidney injury (AKI) diagnosed by the Kidney Disease: Improving Global Outcomes criteria at 72 h before surgery and 72 h after surgery were recorded. The pathological complete response rates, recurrence rate and disease-free survival time after surgery were collected.Results:Compared with group nCT, the serum urea concentration was significantly increased after treatment, the serum uric acid concentrations were increased at 72 h before surgery and 72 h after surgery, the pathological complete response rate was increased, the recurrence rate was decreased, the disease-free survival time was prolonged ( P<0.05), and no statistically significant changes were found in the incidence of AKI at 72 h before surgery and 72 h after surgery in group nCT+ IT ( P>0.05). Conclusions:Although neoadjuvant chemotherapy combined with immunotherapy can raise the pathological complete response rate and disease-free survival rate, it has a certain effect on renal function. Perioperative renal function testing should be strengthened to prevent the occurrence of AKI in the patients undergoing radical resection for esophageal cancer.

Aim To evaluate the effect of hyperoside/chitosan-nanoparticles(Hyp-NPs)on bone marrow mesenchymal stem cells(BMSCs)in vitro cell experi-ments and the underlying mechanism,and to conduct in vivo animal experiments to investigate the synergistic effect of Hyp-NPs and BMSCs on repairing endometrial damage in rats.Methods BMSCs were identified by flow cytometry.Hyp-NPs were prepared by ion crosslinking method,characterized and evaluated by laser particle size analyzer and transmission electron microscopy.The effects of different concentrations of Hyp-NPs on the migration of BMSCs were evaluated by scratch assay and immunofluorescence.NRF2 lentivir-us vector was constructed to explore the mechanism of Hyp-NPs on BMSCs.In animal experiments,Hyp-NPs loaded with BMSCs were co-transplanted into the uter-ine cavity of a rat model of endometrial injury.HE,Masson,IHC,TUNEL,and ELISA experiments were used to systematically evaluate the repair effect and pregnancy function of the composite formulation on rat endometrial injury from multiple aspects and angles,including general pathology,fibrosis,receptivity,cell proliferation,angiogenesis,stem cell recruitment,and inflammation of the endometrium.Results BMSCs were successfully isolated and cultured.Hyp-NPs with high stability and small particle size were successfully prepared.Scratch experiments indicated that Hyp-NPs could promote the migration of BMSCs.By successfully constructing a lentiviral NRF2 vector and oxidative damage model for BMSCs,immunofluorescence experi-ments showed that Hyp-NPs could regulate the biologi-cal axis of BMSCs by activating NRF2.Animal experi-ments showed that the synergistic administration of Hyp-NPs and BMSCs could increase endometrial thick-ness and glandular quantity,promote stem cell homing through anti-fibrotic,anti-apoptotic,and anti-inflam-matory effects,and restore pregnancy function in rats with endometrial injury.Conclusion The synergistic administration of Hyp-NPs and BMSCs could repair en-dometrial injury.