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.

N-acetyl-p-aminophenol （APAP） is an antipyretic analgesic commonly used in clinical practice， and APAP overdose can cause severe liver injury and even death. In recent years， the incidence rate of APAP-induced liver injury （AILI） tends to increase， and it has become the second most common cause of liver transplantation worldwide. Autophagy is a highly conserved catabolic process that removes unwanted cytosolic proteins and organelles through lysosomal degradation to achieve the metabolic needs of cells themselves and the renewal of organelles. A large number of studies have shown that autophagy plays a key role in the pathophysiology of AILI， involving the mechanisms such as APAP protein conjugates， oxidative stress， JNK activation， mitochondrial dysfunction， inflammatory response and apoptosis. This article elaborates on the biological mechanism of autophagy in AILI， in order to provide a theoretical basis for the treatment of AILI and the development of autophagy regulators.

With the rapid development of sequencing technologies, the detection of alternative polyadenylation (APA) in mammals has become more precise. APA precisely regulates gene expression by altering the length and position of the poly(A) tail, and is involved in various biological processes such as disease occurrence and embryonic development. The research on APA in mammals mainly focuses on the following aspects:(1) identifying APA based on transcriptome data and elucidating their characteristics; (2) investigating the relationship between APA and gene expression regulation to reveal its important role in life regulation;(3) exploring the intrinsic connections between APA and disease occurrence, embryonic development, differentiation, and other life processes to provide new perspectives and methods for disease diagnosis and treatment, as well as uncovering embryonic development regulatory mechanisms. In this review, the classification, mechanisms and functions of APA were elaborated in detail and the methods for APA identifying and APA data resources based on various transcriptome data were systematically summarized. Moreover, we epitomized and provided an outlook on research on APA, emphasizing the role of sequencing technologies in driving studies on APA in mammals. In the future, with the further development of sequencing technology, the regulatory mechanisms of APA in mammals will become clearer.

ObjectiveTo investigate the role of 4-week high-intensity interval training (HIIT) in modulating the metabolic homeostasis of the pyruvate-lactate axis in the hippocampus of rats with chronic unpredictable mild stress (CUMS) to improve their depressive-like behavior. MethodsForty-eight SPF-grade 8-week-old male SD rats were randomly divided into 4 groups: the normal quiet group (C), the CUMS quiet group (M), the normal exercise group (HC), and the CUMS exercise group (HM). The M and HM groups received 8 weeks of CUMS modeling, while the HC and HM groups were exposed to 4 weeks of HIIT starting from the 5th week (3 min (85%-90%) S_max+1 min (50%-55%) S_max, 3-5 cycles, S_max is the maximum movement speed). A lactate analyzer was used to detect the blood lactate concentration in the quiet state of rats in the HC and HM groups at week 4 and in the 0, 2, 4, 8, 12, and 24 h after exercise, as well as in the quiet state of rats in each group at week 8. Behavioral indexes such as sucrose preference rate, number of times of uprightness and number of traversing frames in the absenteeism experiment, and other behavioral indexes were used to assess the depressive-like behavior of the rats at week 4 and week 8. The rats were anesthetized on the next day after the behavioral test in week 8, and hippocampal tissues were taken for assay. LC-MS non-targeted metabolomics, target quantification, ELISA and Western blot were used to detect the changes in metabolite content, lactate and pyruvate concentration, the content of key metabolic enzymes in the pyruvate-lactate axis, and the protein expression levels of monocarboxylate transporters (MCTs). Results4-week HIIT intervention significantly increased the sucrose preference rate, the number of uprights and the number of traversed frames in the absent field experiment in CUMS rats; non-targeted metabolomics assay found that 21 metabolites were significantly changed in group M compared to group C, and 14 and 11 differential metabolites were significantly dialed back in the HC and HM groups, respectively, after the 4-week HIIT intervention; the quantitative results of the targeting showed that, compared to group C, lactate concentration in the hippocampal tissues of M group, compared with group C, lactate concentration in hippocampal tissue was significantly reduced and pyruvate concentration was significantly increased, and 4-week HIIT intervention significantly increased the concentration of lactate and pyruvate in hippocampal tissue of HM group; the trend of changes in blood lactate concentration was consistent with the change in lactate concentration in hippocampal tissue; compared with group C, the LDHB content of group M was significantly increased, the content of PKM2 and PDH, as well as the protein expression level of MCT2 and MCT4 were significantly reduced. The 4-week HIIT intervention upregulated the PKM2 and PDH content as well as the protein expression levels of MCT2 and MCT4 in the HM group. ConclusionThe 4-week HIIT intervention upregulated blood lactate concentration and PKM2 and PDH metabolizing enzymes in hippocampal tissues of CUMS rats, and upregulated the expression of MCT2 and MCT4 transport carrier proteins to promote central lactate uptake and utilization, which regulated metabolic homeostasis of the pyruvate-lactate axis and improved depressive-like behaviors.

ObjectiveThis study aimed to investigate the effects of 4-week high-intensity interval training (HIIT) on synaptic plasticity in the prefrontal cortex (PFC) of rats exposed to chronic unpredictable mild stress (CUMS), and to explore its potential mechanisms. MethodsA total of 48 male Sprague-Dawley rats were randomly divided into 4 groups: control (C), model (M), control plus HIIT (HC), and model plus HIIT (HM). Rats in groups M and HM underwent 8 weeks of CUMS to establish depression-like behaviors, while groups HC and HM received HIIT intervention beginning from the 5th week for 4 consecutive weeks. The HIIT protocol consisted of repeated intervals of 3 min at high speed (85%-90% maximal training speed, S_max) alternated with one minute at low speed (50%-55% S_max), with 3 to 5 sets per session, conducted 5 d per week. Behavioral assessments and tail-vein blood lactate levels were measured at the end of the 4th and 8th weeks. After the intervention, rat PFC tissues were collected for Golgi staining to analyze synaptic morphology. Enzyme-linked immunosorbent assays (ELISA) were employed to detect brain-derived neurotrophic factor (BDNF), monocarboxylate transporter 1 (MCT1), lactate, and glutamate levels in the PFC, as well as serotonin (5-HT) levels in serum. Additionally, Western blot analysis was conducted to quantify the expression of synaptic plasticity-related proteins, including c-Fos, activity-regulated cytoskeleton-associated protein (Arc), and N-methyl-D-aspartate receptor 1 (NMDAR1). ResultsCompared to the control group (C), the CUMS-exposed rats (group M) exhibited significant reductions in sucrose preference rates, number of grid crossings, frequency of upright postures, and entries into and duration spent in open arms of the elevated plus maze, indicating marked depressive-like behaviors. Additionally, the group M showed significantly reduced dendritic spine density in the PFC, along with elevated levels of c-Fos, Arc, NMDAR1 protein expression, and increased concentrations of lactate and glutamate. Conversely, BDNF and MCT1 contents in the PFC and 5-HT levels in serum were significantly decreased. Following HIIT intervention, rats in the group HM displayed considerable improvement in behavioral indicators compared with the group M, accompanied by significant elevations in PFC MCT1 and lactate concentrations. Furthermore, HIIT notably normalized the expression levels of c-Fos, Arc, NMDAR1, as well as glutamate and BDNF contents in the PFC. Synaptic spine density also exhibited significant recovery. ConclusionFour weeks of HIIT intervention may alleviate depressive-like behaviors in CUMS rats by increasing lactate levels and reducing glutamate concentration in the PFC, thereby downregulating the overexpression of NMDAR, attenuating excitotoxicity, and enhancing synaptic plasticity.

Aim To screen and study the effects of Tao Hong Si Wu decoction(THSWD)-mediated treat-ment on circular RNA(circRNA)expression profiles in rats with middle cerebral artery occlusion(MCAO),and investigate the possible roles and molecular mecha-nisms of THSWD.Methods Next-generation RNA sequencing was conducted to identify circRNA expres-sion profiles in MCAO rats after treatment with THSWD and compared with the MCAO model group and control group.Bioinformatics analysis was performed to predict the potential target microRNAs and mRNAs.Gene On-tology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analyses for the potential target mRNAs were applied to explore the potential roles of differentially expressed circRNAs.RT-qPCR was performed to verify circRNAs with significant differences in expression.Results We identified 87 significantly differentially expressed circRNAs between the MCAO group versus the control group,and 86 sig-nificantly differentially expressed circRNAs between the MCAO group versus the THSWD group.respective-ly.Among them,17 circRNAs induced by the MCAO model were reversed via treatment with THSWD.To demonstrate the roles of mRNAs targeted by DECs,the GO and KEGG databases were used.Further analysis revealed that five circRNAs may play important roles in the development of MCAO.Conclusions The com-prehensive expression profile of circRNAs in rats with middle cerebral artery occlusion after THSWD treat-ment is determined for the first time,suggesting that the therapeutic effect of THSWD on MCAO may be a-chieved by regulating the expression of circRNAs.

Aim To explore the effect of total flavonoid extract(TFE)of Ampelopsis megalophylla on the pro-liferation and apoptosis of human breast cancer cells and its mechanism in autophagy inhibition.Methods For human cervical cancer cell Hela,human lung cancer cell A549,human liver cancer cell SMMC-7721,human breast cancer cell MCF-7,MDA-MB-231 and human normal liver cell L-02,MTT method was used to select sensitive cell lines.The inhibitory effect of TFE combined with autophagy inhibitor 3-methylade-nine(3-MA)on sensitive cell proliferation was detec-ted using MTT assay.The morphological changes of cells were observed using transmission electron micros-copy and Hoechst 33258 single staining method.The changes in cell apoptosis rate were detected using An-nexin V-FITC/PI dual staining method.The expression levels of apoptosis related proteins and pathway pro-teins(death receptor pathway,mitochondrial pathway,endoplasmic reticulum stress pathway)were detected uisng Western blot.The expression of the key protein Cyt-c in mitochondrial pathway was determiend by im-munofluorescence,and the autophagy agonist rapamy-cin was selected for reverse validation.Results TFE could inhibit the proliferation of human breast cancer cells in a concentration-dependent manner,and MCF-7 cells were sensitive cell lines.Compared with the TFE group,the TFE+3-MA group significantly increased the inhibition rate of MCF-7 cells at 24,48,and 72 h(P＜0.01).The number of cells decreased,the gap increased,the number of apoptotic bodies increased,and the apoptosis rate increased(P＜0.01).The ex-pression levels of Bax/Bcl-2(P＜0.01),cleaved-caspase3(P＜0.01),Cyt-c(P＜0.05),FADD,and cleaved-caspase-12 all increased,and the expres-sion of apoptotic protein Cyt-c in nucleus increased.The fluorescence of the TFE+RA group decreased,re-versing the mitochondrial pathway apoptosis induced by TFE.Conclusions TFE can significantly inhibit the proliferation of human breast cancer cells.When inhib-iting autophagy,it may promote the apoptosis of MCF-7 cells through the mitochondrial pathway,and activa-ting autophagy can reverse apoptosis.

Aim To investigate the enhanced efficacy and reduced toxicity of GanoExtra in combination with cyclophosphamide(CTX)on inhibiting lung metastasis and immune function in mice.Methods The CCK-8 method was used to verify the cytotoxic effects of Gano-Extra on MCF-7 and 4T1 tumor cells.In vivo experi-ment,a mouse model of lung metastasis of breast canc-er was established by injecting 4T1 tumor cells into the tail vein,which was divided into four groups including 4T1 model group,CTX group,GanoExtra group and GanoExtra+CTX group.The control group was set.After 21 days,the mice were euthanized under anes-thesia,and the body weight of the mice was recorded.Average lung index and spleen index were calculated.The mouse spleen lymphocyte transformation experi-ment was used to determine the activity of spleen cells.The NK cell activity assay was used to determine the activity of NK cells.Blood cells were determined in mouse blood samples.Flow cytometry was used to de-termine the levels of CD4+and CD8+T cells in blood samples.ELISA was used to measure the levels of TNF-α and IL-6 in serum.HE staining was used to ob-serve the pathological morphological changes in tumors and various tissues;and CFSE staining was used to de-termine the proliferative effect of GanoExtra on CD8+cells.Results In vitro GanoExtra at 50 mg·L-1 sig-nificantly inhibited the activity of MCF-7 and 4T1 tumor cells.In the breast cancer pulmonary metastasis model,compared with the model group,the spleen in-dex and blood WBCs content were significantly re-duced,while the activity of NK cells,spleen cells,and the proportion of RBCs,CD 3+and CD 8+T cells in the blood were significantly increased.At the end of the treatment,compared with the CTX group,the number of lung metastases and lung index of the Gano-Extra+CTX group were significantly reduced,and the levels of HGB,CD8+cells,IL-6,and TNF-α in the blood of mice were significantly increased.GanoExtra at 10 mg·L-1 significantly promoted the proliferation of CD8+T cells in vitro.Conclusions GanoExtra can enhance the inhibitory effect of CTX on tumor metasta-sis,alleviate adverse reactions such as splenomegaly and pulmonary enlargement caused by CTX,and have a health-promoting function of promoting the prolifera-tion of CD8+T cells to enhance the immune efficacy of the body.

Objective To investigate the distribution and antimicrobial resistance profiles of the common pathogens isolated from urine from 2015 to 2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods The bacterial strains were isolated from urine and identified routinely in 51 hospitals across China in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Antimicrobial susceptibility was determined by Kirby-Bauer method,automatic microbiological analysis system and E-test according to the unified protocol.Results A total of 261 893 nonduplicate strains were isolated from urine specimen from 2015 to 2021,of which gram-positive bacteria accounted for 23.8％(62 219/261 893),and gram-negative bacteria 76.2％(199 674/261 893).The most common species were E.coli(46.7％),E.faecium(10.4％),K.pneumoniae(9.8％),E.faecalis(8.7％),P.mirabilis(3.5％),P.aeruginosa(3.4％),SS.agalactiae(2.6％),and E.cloacae(2.1％).The strains were more frequently isolated from inpatients versus outpatients and emergency patients,from females versus males,and from adults versus children.The prevalence of ESBLs-producing strains in E.coli,K.pneumoniae and P.mirabilis was 53.2％,52.8％and 37.0％,respectively.The prevalence of carbapenem-resistant strains in E.coli,K.pneumoniae,P.aeruginosa and A.baumannii was 1.7％,18.5％,16.4％,and 40.3％,respectively.Lower than 10％of the E.faecalis isolates were resistant to ampicillin,nitrofurantoin,linezolid,vancomycin,teicoplanin and fosfomycin.More than 90％of the E.faecium isolates were ressitant to ampicillin,levofloxacin and erythromycin.The percentage of strains resistant to vancomycin,linezolid or teicoplanin was＜2％.The E.coli,K.pneumoniae,P.aeruginosa and A.baumannii strains isolated from ICU inpatients showed significantly higher resistance rates than the corresponding strains isolated from outpatients and non-ICU inpatients.Conclusions E.coli,Enterococcus and K.pneumoniae are the most common pathogens in urinary tract infection.The bacterial species and antimicrobial resistance of urinary isolates vary with different populations.More attention should be paid to antimicrobial resistance surveillance and reduce the irrational use of antimicrobial agents.

Objective To understand the distribution and changing resistance profiles of clinical isolates of Enterococcus in hospitals across China from 2015 to 2021.Methods Antimicrobial susceptibility testing was conducted for the clinical isolates of Enterococcus according to the unified protocol of CHINET program by automated systems,Kirby-Bauer method,or E-test strip.The results were interpreted according to the Clinical & Laboratory Standards Institute(CLSI)breakpoints in 2021.WHONET 5.6 software was used for statistical analysis.Results A total of 124 565 strains of Enterococcus were isolated during the 7-year period,mainly including Enterococcus faecalis(50.7％)and Enterococcus faecalis(41.5％).The strains were mainly isolated from urinary tract specimens(46.9％±2.6％),and primarily from the patients in the department of internal medicine,surgery and ICU.E.faecium and E.faecalis strains showed low level resistance rate to vancomycin,teicoplanin and linezolid(≤3.6％).The prevalence of vancomycin-resistant E.faecalis and E.faecium was 0.1％and 1.3％,respectively.The prevalence of linezolid-resistant E.faecalis increased from 0.7％in 2015 to 3.4％in 2021,while the prevalence of linezolid-resistant E.faecium was 0.3％.Conclusions The clinical isolates of Enterococcus were still highly susceptible to vancomycin,teicoplanin,and linezolid,evidenced by a low resistance rate.However,the prevalence of linezolid-resistant E.faecalis was increasing during the 7-year period.It is necessary to strengthen antimicrobial resistance surveillance to effectively identify the emergence of antibiotic-resistant bacteria and curb the spread of resistant pathogens.