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.

Objective To explore the protective mechanism of icariin on neuronal oxidative damage,providing a basic pharmacological basis for the treatment of cognitive impairment.Methods Glutamate was used to induce oxidative stress injury in HT22 cells.HT22 cells were divided into control group(normal cultured cells),model group(glutamate injury model)and experimental-L,-M,-H groups(5,10 and 20 μmol·L-1 icariin pretreatment for modeling,respectively).Cell proliferation was detected by cell counting kit-8(CCK-8)method;cytotoxicity was detected by lactate dehydrogenase(LDH)method;reactive oxygen species(ROS)levels were detected by flow cytometry;superoxide dismutase(SOD)levels were detected by biochemical kits;the expression levels of Kelch-like epichlorohydrin-related protein-1(Keap1),nuclear factor E2-related factor 2(Nrf2)were detected by Western blotting;the corresponding mRNA expression was detected by real-time fluorescence quantification polymerose chain reaction.Results The cell viability of control group,model group and experimental-L,-M,-H groups were(100.00±1.31)％,(66.38±2.44)％,(72.07±4.95)％,(82.41±3.57)％and(87.97±4.98)％;LDH release were(0.48±0.52)％,(18.82±2.09)％,(15.32±1.17)％,(10.37±1.39)％and(6.51±0.87)％;ROS level were(14.23±1.13)％,(41.74±1.60)％,(35.69±1.08)％,(33.28±1.69)％and(30.32±2.03)％;SOD levels were(54.84±1.17),(37.95±1.13),(48.02±1.28),(50.56±1.34)and(52.55±1.04)U·mg-1;Keap1 protein levels were 0.36±0.01,0.52±0.03,0.46±0.04,0.39±0.09 and 0.35±0.12;Nrf2 protein levels were 0.29±0.02,0.13±0.08,0.18±0.03,0.21±0.11 and 0.26±0.04;catalase(CAT)mRNA levels were 1.01±0.08,0.81±0.06,0.90±0.04,1.05±0.15 and 1.33±0.26;SOD mRNA levels were 1.09±0.12,0.83±0.03,0.86±0.08,0.94±0.08 and 1.09±0.16.Among the above indicators,the differences between the model group and the control group were statistically significant(all P＜0.01);the differences between the experimental-M,-H groups and the model group were statistically significant(P＜0.01,P＜0.05).Conclusion Icariin may activate the Keap1/Nrf2/antioxidant response element(ARE)signaling pathway,regulate the expression of related proteins,and reduce the level of ROS to effectively alleviate oxidative stress injury in neuronal cells.

Thrombosis is a key factor that increases the mortality rate of COVID-19 patients and causes long COVID sequelae. Guanxinning Tablet (GXNT), which is composed of Salvia miltiorrhiza and Ligusticum Chuanxiong, has significant antithrombotic activity, but the similarities and differences between its anti-conventional thrombus and microthrombus induced by COVID-19 remain unclear. In this paper, the main active components, potential targets and mechanisms of GXNT in the treatment of thrombus and microthrombus caused by COVID-19 were preliminarily revealed by using anti-platelet experiments in vitro, network pharmacology analysis, molecular docking technology and molecular biology experiments. The results of platelet aggregation and adhesion experiments in vitro showed that GXNT had significant anti-platelet aggregation and adhesion activities in a dose-dependent manner. Using network pharmacology analysis, it was revealed that salvianolic acid B, tanshinone IIA, caffeic acid and ligustrazine in GXNT could resist thrombus and microthrombus caused by COVID-19 through key targets as the high mobility group box 1 protein (HMGB1), tumor necrosis factor (TNF), interleukin 6 (IL6) and AKT serine/threonine kinase 1 (AKT1). HMGB1 signaling pathway is one of its key common mechanisms. Western blot also indicated that GXNT significantly inhibited the expression of HMGB1 protein in platelets. In summary, this paper explores the similarities and differences between the mechanism of GXNT against conventional thrombus and microthrombus caused by COVID-19 and provides drug reference and theoretical basis for clinical prevention and treatment of long COVID sequelae. The animal experiment has been approved by the Experimental Animal Ethics Committee of Tianjin University of Traditional Chinese Medicine (No. TCM-LAEC2023187g1549).

Activation of nuclear factor erythroid 2-related factor 2(Nrf2)by Kelch-like ECH-associated protein 1(Keap1)alkylation plays a central role in anti-inflammatory therapy.However,activators of Nrf2 through alkylation of Keap1-Kelch domain have not been identified.Deoxynyboquinone(DNQ)is a natural small molecule discovered from marine actinomycetes.The current study was designed to investigate the anti-inflammatory effects and molecular mechanisms of DNQ via alkylation of Keap1.DNQ exhibited signif-icant anti-inflammatory properties both in vitro and in vivo.The pharmacophore responsible for the anti-inflammatory properties of DNQ was determined to be the α,β-unsaturated amides moieties by a chemical reaction between DNQ and N-acetylcysteine.DNQ exerted anti-inflammatory effects through activation of Nrf2/ARE pathway.Keap1 was demonstrated to be the direct target of DNQ and bound with DNQ through conjugate addition reaction involving alkylation.The specific alkylation site of DNQ on Keap1 for Nrf2 activation was elucidated with a synthesized probe in conjunction with liquid chromatography-tandem mass spectrometry.DNQ triggered the ubiquitination and subsequent degra-dation of Keap1 by alkylation of the cysteine residue 489(Cys489)on Keap1-Kelch domain,ultimately enabling the activation of Nrf2.Our findings revealed that DNQ exhibited potent anti-inflammatory capacity through α,β-unsaturated amides moieties active group which specifically activated Nrf2 signal pathway via alkylation/ubiquitination of Keap1-Kelch domain,suggesting the potential values of targeting Cys489 on Keap1-Kelch domain by DNQ-like small molecules in inflammatory therapies.

Based on the views of FAN's Eight Dynamic-Static Sequential Methods,Professor FAN Guan-Jie believes that the obesity has the pathological factor of blood stasis in addition to qi deficiency and phlegm-damp.The compatibility of blood-activating and stasis-removing drugs for the treatment of obesity is accorded to the progression of the disease.In the clinic,Crataegi Fructus associated medicinal cluster of activating blood and removing stasis is usually recommended.The medicinal cluster is with Crataegi Fructus as the chief medicinal,and is compatible with drug pairs of Salviae Miltiorrhizae Radix et Rhizoma-Carthami Flos and Moutan Cortex-Paeoniae Radix Rubra.Crataegi Fructus associated medicinal cluster is able to treat qi and blood simultaneously,mainly aimed at removing blood stasis,supplemented by nourishing blood,promoting qi and blood movement,and invigorating spleen and stomach,which has the features of simultaneous dispersing and astringency,and proper combination of static therapy and dynamic therapy,and is suitable for obese patients with blood stasis obstruction in the vessels.

Objective To investigate the factors influencing prognosis in patients with acute myocardial infarction complicated with cardiogenic shock undergoing primary percutaneous coronary intervention(PPCI).Methods Patients with acute myocardial infarction complicated with cardiogenic shock who underwent PPCI at our hospital between January 2015 and December 2019 were enrolled.Clinical baseline characteristics,coronary angiography and PCI-related parameters,and mechanical support information were collected.The patients were followed up for one year and divided into survival and death groups based on their survival status within one year.Differences in various factors between the two groups were compared.Results A total of 40 patients were enrolled,including 26 in the survival group and 14 in the death group.There were no differences in baseline data,diagnosis,risk factors,and comorbidities between the two groups.The survival group had a lower heart rate and higher blood pressure trend at admission compared to the death group.Myocardial enzymes were significantly lower in the survival group compared to the death group(median CK peak:496.00(198.25,2 830.00)U/L vs.3 040.00(405.75,5 626.53)U/L,P=0.003;median CK-MB peak:52.65(31.75,219.50)U/L vs.306.00(27.25,489.63)U/L,P=0.006).When comparing coronary angiography and PCI-related indicators between the two groups,the survival group had a higher rate of complete revascularization compared to the control group(53.85％vs.21.43％,P=0.048).The survival group had a higher proportion of extracorporeal membrane oxygenation(ECMO)combined with intra-aortic balloon pump(IABP)support compared to the control group[38.46％vs.7.14％,P=0.034].Conclusions Survival in patients with acute myocardial infarction complicated with cardiogenic shock undergoing PPCI is associated with lower level of myocardial enzymes,ECMO combined with IABP support and complete revascularization.

Metastasis is the main risk factor for poor prognosis of laryngeal squamous cell carcinoma (LSCC) .Chemokines are closely related to metastasis in the tumor microenvironment.CXCL8 is a cyto-kine-like secreted protein that plays key roles in the malignant development of a variety of tumors,but has not been elucidated in LSCC.In this paper,we elucidated the role of CXCL8 in LSCC cells and found miRNAs that targeted CXCL8,which may become new targets for the diagnosis and treatment of LSCC.Firstly,the GEPIA showed that CXCL8 was highly expressed in head and neck cancer (P<0.05).The real-time fluorescence quantification (qRT-PCR) found that CXCL8 was highly expressed in LSCC cells.The enzyme-linked immunoassay also found that CXCL8 was highly secreted in the superna-tant of LSCC cells (P<0.001) .Then,the CCK8 assay confirmed that knockdown of CXCL8 significant-ly inhibited the proliferation of FD-LSC-1 and AMC-HN8 cells (the average inhibition rate was 34.0％and 19.5％,respectively);The EdU assay also confirmed that knockdown of CXCL8 significantly inhibi-ted the proliferation of LSCC cells (P<0.05) .The transwell assay confirmed that knockdown of CXCL8 also significantly inhibited the migration and invasion of FD-LSC-1 cell (average inhibition rate was 40.0％,38.5％,respectively);Knockdown of CXCL8 also significantly inhibited the migration and inva-sion of AMC-HN8 cell (average inhibition rate was 37.5％,53.5％,respectively ) .The analysis of bioinformatics predicted that CXCL8 may be a target of miR-513b-5p.The dual luciferase reporter assay confirmed that miR-513b-5p could bind to the CXCL8-3'UTR.QRT-PCR assay also confirmed that over-expression of miR-513b-5p could decrease the 60％ of the CXCL8 expression (P<0.01) .Cell function rescue assays found that overexpressed of CXCL8 could effectively reversed proliferation,migration and invasion of LSCC cells weakened by miR-513b-5p (P<0.05) .In summary,miR-513b-5p inhibited the proliferation,migration and invasion of LSCC cells by targeting CXCL8.

Purpose: This study explored the association of the elasticity modulus and shear wave velocity (SWV) of the tibialis anterior muscle, as measured by two-dimensional shear wave elastography (2D-SWE), with the intracompartmental pressure (ICP) determined using the Whitesides method in a New Zealand rabbit model of acute compartment syndrome (ACS). Additionally, it evaluated the viability of 2D-SWE as a noninvasive, quantitative tool for the early detection of ACS. Methods: An ACS model was established through direct external compression by applying pressure bandaging to the lower legs of 15 New Zealand rabbits using neonatal blood pressure cuffs. Another five animals represented a non-modeled control group. To measure the elasticity modulus and SWV of the tibialis anterior muscles, 2D-SWE was employed. Blood oxygen saturation, serum creatine kinase (CK), and myoglobin levels were monitored. Subsequently, the anterior tibial compartment was dissected, and the tibialis anterior was removed for hematoxylin and eosin staining to assess muscle injury. Results: The elasticity modulus and SWV of the tibialis anterior muscle increased with compression duration, as did serum CK and myoglobin levels. ICP was strongly positively correlated with these parameters, particularly mean velocity (r=0.942, P<0.001) and CK (r=0.942, P<0.001). Blood oxygen saturation was negatively correlated with ICP (r=-0.887, P<0.001). Histological analysis indicated progressive muscle cell swelling over time, with damage transitioning from reversible to irreversible and culminating in necrosis. Conclusion In a rabbit ACS model, ICP was strongly positively correlated with muscle elasticity modulus/SWV. Consequently, 2D-SWE may represent a novel tool for assessing early-phase ACS.

Purpose: This study explored the association of the elasticity modulus and shear wave velocity (SWV) of the tibialis anterior muscle, as measured by two-dimensional shear wave elastography (2D-SWE), with the intracompartmental pressure (ICP) determined using the Whitesides method in a New Zealand rabbit model of acute compartment syndrome (ACS). Additionally, it evaluated the viability of 2D-SWE as a noninvasive, quantitative tool for the early detection of ACS. Methods: An ACS model was established through direct external compression by applying pressure bandaging to the lower legs of 15 New Zealand rabbits using neonatal blood pressure cuffs. Another five animals represented a non-modeled control group. To measure the elasticity modulus and SWV of the tibialis anterior muscles, 2D-SWE was employed. Blood oxygen saturation, serum creatine kinase (CK), and myoglobin levels were monitored. Subsequently, the anterior tibial compartment was dissected, and the tibialis anterior was removed for hematoxylin and eosin staining to assess muscle injury. Results: The elasticity modulus and SWV of the tibialis anterior muscle increased with compression duration, as did serum CK and myoglobin levels. ICP was strongly positively correlated with these parameters, particularly mean velocity (r=0.942, P<0.001) and CK (r=0.942, P<0.001). Blood oxygen saturation was negatively correlated with ICP (r=-0.887, P<0.001). Histological analysis indicated progressive muscle cell swelling over time, with damage transitioning from reversible to irreversible and culminating in necrosis. Conclusion In a rabbit ACS model, ICP was strongly positively correlated with muscle elasticity modulus/SWV. Consequently, 2D-SWE may represent a novel tool for assessing early-phase ACS.

Purpose: This study explored the association of the elasticity modulus and shear wave velocity (SWV) of the tibialis anterior muscle, as measured by two-dimensional shear wave elastography (2D-SWE), with the intracompartmental pressure (ICP) determined using the Whitesides method in a New Zealand rabbit model of acute compartment syndrome (ACS). Additionally, it evaluated the viability of 2D-SWE as a noninvasive, quantitative tool for the early detection of ACS. Methods: An ACS model was established through direct external compression by applying pressure bandaging to the lower legs of 15 New Zealand rabbits using neonatal blood pressure cuffs. Another five animals represented a non-modeled control group. To measure the elasticity modulus and SWV of the tibialis anterior muscles, 2D-SWE was employed. Blood oxygen saturation, serum creatine kinase (CK), and myoglobin levels were monitored. Subsequently, the anterior tibial compartment was dissected, and the tibialis anterior was removed for hematoxylin and eosin staining to assess muscle injury. Results: The elasticity modulus and SWV of the tibialis anterior muscle increased with compression duration, as did serum CK and myoglobin levels. ICP was strongly positively correlated with these parameters, particularly mean velocity (r=0.942, P<0.001) and CK (r=0.942, P<0.001). Blood oxygen saturation was negatively correlated with ICP (r=-0.887, P<0.001). Histological analysis indicated progressive muscle cell swelling over time, with damage transitioning from reversible to irreversible and culminating in necrosis. Conclusion In a rabbit ACS model, ICP was strongly positively correlated with muscle elasticity modulus/SWV. Consequently, 2D-SWE may represent a novel tool for assessing early-phase ACS.