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 clarify the expression and distribution of brain⁃derived neurotrophic factor (BDNF) in the cerebrum of plateau yaks and cattle, and to explore the relationship between BDNF function and the adaptability of altitude hypoxia. Methods Five yaks and five cattles were selected.The content and distribution of BDNF in frontal lobe, temporal lobe, parietal lobe, occipital lobe, cerebrum white matter and hippocampus of yak and cattle were analyzed by Real⁃time PCR, Western blotting and Immunohistochemistry. Results Real⁃time PCR result showed that BDNF mRNA expression in the cerebrum of yaks and cattles was highest in temporal cortex, followed by hippocampus, parietal cortex, occipital cortex and frontal cortex, and lowest in white matter. Western blotting results showed that the content of BDNF protein in the cerebrum of yaks was the highest in temporal cortex,followed by hippocampus. The content of BDNF protein in other tissues was parietal cortex, frontal cortex and cerebrum white matter, and the content of BDNF protein was the lowest in occipital cortex. The content of BDNF protein intlecerebrum of cattles was the highest in the temporal cortex, followed by the hippocampus. The content of BDNF protein in other tissues was parietal cortex, occipital cortex and frontal cortex in descending order, and the protein content in cerebrum white matter was the lowest. Immunohistochemical results showed that the positive expression of BDNF protein in the cerebrum of yaks and cattles was basically similar, mainly distributed in the granulosa cells and glial cells in the frontal cortex, temporal cortex, parietal cortex and occipital cortex, glial cells in cerebrum white matter, pyramidal cell layer and polyform cell layer in the hippocampus. There was the small amount of distribution in Martinotti cells and the molecular layer of hippocampus in the cerebral cortex. Conclusion BDNF mRNA and protein are distributed and expressed in different brain regions of yaks and cattles, but the expression level different, which is speculated to be closely related to the specific functions of different cerebrum regions. The expression level of the cerebrum of yak is higher than that of cattle except occipital cortex, suggesting that it is related to the altitude hypoxic environment. BDNF may play an important role in enhancing hypoxic tolerance and protecting internal environmental homeostasis in the process of animal adaptation to hypoxic environment.

AIM:To investigate the effect of circular RNA MYO9A-006(circMYO9A_006)on hypertrophic phenotype of cardiomyocytes and the underlying mechanism.METHODS:The effect of adenovirus-mediated overexpres-sion of circMYO9A_006 on the expression of hypertrophy-related proteins,including β-myosin heavy chain(β-MHC),skeletal muscle actin alpha 1(ACTA1)and atrial natriuretic peptide(ANP),was evaluated in neonatal mouse ventricular cardiomyocytes(NMVCs).Moreover,a neonatal rat ventricular cardiomyocyte(NRVC)model of phenylephrine(PE)-in-duced hypertrophy was established.The effect of circMYO9A_006 overexpression on NRVC size was ascertained using Phalloidin-iFluor 647 staining method.Dual-luciferase reporter assay was employed to measure the activity of potential in-ternal ribosome entry sites(IRES)in circMYO9A_006.The translation and intracellular location of the circMYO9A_006-translated protein,MYO9A-208aa,were verified using Western blot.To investigate the role of MYO9A-208aa in the ef-fect of circMYO9A_006 on the cardiomyocyte hypertrophic phenotype,we prepared and used the following adenoviruses:the recombinant circMYO9A_006-ORF adenovirus to express MYO9A-208aa,the recombinant circMYO9A_006-ATG-mut adenovirus that does not express MYO9A-208aa,the recombinant circMYO9A_006 adenovirus,and the adenovirus vector control.These were then employed to infect NRVCs.RESULTS:Successful adenovirus-mediated overexpression of circMYO9A_006 was observed in NMVCs.The increased expression of circMYO9A_006 notably reduced the expres-sion of hypertrophy-related proteins in NMVCs(P<0.01).Concurrently,overexpression of circMYO9A_006 substantially reduced the expression of hypertrophy-associated proteins and diminished the size of PE-induced NRVCs(P<0.05).Dual-luciferase reporter assay identified the activity of 2 IRES in circMYO9A_006.Western blot results indicated that circ-MYO9A_006 could produce the MYO9A-208aa protein with an anticipated molecular weight of 28 kD in NRVCs,primari-ly found in the cytoplasm.Elevated expression of both circMYO9A_006 and MYO9A-208aa consistently reduced the ex-pression of hypertrophy-associated proteins(P<0.01),and counteracted the enlarged size of PE-induced NRVCs(P<0.05).However,increased expression of circMYO9A_006-ATG-mut did not counteract the PE-induced hypertrophic phe-notype of NRVCs.CONCLUSION:circMYO9A_006 attenuates the hypertrophic phenotype of cardiomyocytes by synthe-sizing the MYO9A-208aa protein.

Objective To investigate the prevalence of tick-borne rickettsial infections in selected areas of Liupanshui City, Guizhou Province, 2023, so as to provide insights into the management of tick-borne rickettsioses in the city. Methods Ticks were captured from the body surface of bovines and sheep in Gaoxing Village, Dashan Township, Liupanshui City, Guizhou Province during the period between April and June, 2023, and tick species were identified using morphological and molecular biological techniques. In addition, tick-borne Rickettsia was identified using a nested PCR assay, including spotted fever group rickettsiae (SFGR), Coxiella spp., Anaplasma spp., Ehrlichia spp., and Orientia spp., and positive amplified fragments were sequenced and aligned with known sequences accessed in the GenBank database. Results A total of 200 ticks were collected and all tick species were identified as Rhipicephalus microplus. Nestle PCR assay combined with sequencing identified ticks carrying Candidatus Rickettsia jingxinensis (40.50%), Coxiella burnetii (1.50%), and Coxiella-like endosymbionts (27.00%), and Anaplasma spp., Ehrlichia spp. or Orientsia spp. was not detected. Conclusions R. microplus carried Candidatus R. jingxinensis, C. burnetii, and Coxiella-like endosymbionts in selected areas of Liupanshui City, Guizhou Province. Intensified monitoring of tickborne rickettsial infections is needed in livestock and humans to reduce the damages caused by rickettsioses.

Objective The purpose of this study was to investigate the bacterial communities of biting midges and ticks collected from three sites in the Poyang Lake area,namely,Qunlu Practice Base,Peach Blossom Garden,and Huangtong Animal Husbandry,and whether vectors carry any bacterial pathogens that may cause diseases to humans,to provide scientific basis for prospective pathogen discovery and disease prevention and control. Methods Using a metataxonomics approach in concert with full-length 16S rRNA gene sequencing and operational phylogenetic unit(OPU)analysis,we characterized the species-level microbial community structure of two important vector species,biting midges and ticks,including 33 arthropod samples comprising 3,885 individuals,collected around Poyang Lake. Results A total of 662 OPUs were classified in biting midges,including 195 known species and 373 potentially new species,and 618 OPUs were classified in ticks,including 217 known species and 326 potentially new species.Surprisingly,OPUs with potentially pathogenicity were detected in both arthropod vectors,with 66 known species of biting midges reported to carry potential pathogens,including Asaia lannensis and Rickettsia bellii,compared to 50 in ticks,such as Acinetobacter lwoffii and Staphylococcus sciuri.We found that Proteobacteria was the most dominant group in both midges and ticks.Furthermore,the outcomes demonstrated that the microbiota of midges and ticks tend to be governed by a few highly abundant bacteria.Pantoea sp7 was predominant in biting midges,while Coxiella sp1 was enriched in ticks.Meanwhile,Coxiella spp.,which may be essential for the survival of Haemaphysalis longicornis Neumann,were detected in all tick samples.The identification of dominant species and pathogens of biting midges and ticks in this study serves to broaden our knowledge associated to microbes of arthropod vectors. Conclusion Biting midges and ticks carry large numbers of known and potentially novel bacteria,and carry a wide range of potentially pathogenic bacteria,which may pose a risk of infection to humans and animals.The microbial communities of midges and ticks tend to be dominated by a few highly abundant bacteria.

Objective To observe the therapeutic effect and mechanism of acupuncture at Zusanli-Zhongwan combined matching points on rats with exercise-induced stress gastric ulcer.Methods Forty male SD rats were randomly divided into blank group,model group,acupuncture group and Omeprazole group,with 10 rats in each group.Except for the blank group,the rats in the other groups were used to construct the model of exercise stress gastric ulcer by daily exhaustive swimming.After successful modeling,the acupuncture group was intervened by acupuncture at Zusanli(ST36)and Zhongwan(RN12),once a day,10 minutes each time.Rats in the Omeprazole group were given Omeprazole Enteric-Coated Tablets distilled water suspension by gavage two hours before daily swimming.After continuous 7-day intervention,the overall state and behavior of rats were observed,the gastric mucosal injury index was calculated by Guth method,the pathological morphology of gastric mucosa was observed by hematoxylin-eosin(HE)staining,the contents of superoxide dismutase(SOD),glutathione peroxidase(GSH-PX)and malondialdehyde(MDA)in serum were correspondingly determined by WST-1 method,colorimetry and TBA method,respectively,enzyme-linked immunosorbent assay(ELISA)was used to detect the contents of gastrin(GAS),somatostatin(SS),tumor necrosis factor-α(TNF-α),interleukin-1 β(IL-1β),interleukin-6(IL-6)and interleukin-10(IL-10)in serum,the expression levels of epidermal growth factor receptor(EGFR),matrix metalloproteinase 3(MMP3),nuclear factor erythroid-related factor 2(NRF2),heme oxygenase 1(HO-1)and mitochondrial SOD2,TNF-α,IL-1β,IL-6 and IL-10 mRNA in gastric mucosa were detected by real-time fluorescence quantitative polymerase chain reaction(qPCR).Results Compared with the blank group,the body mass of rats in the model group was increased slowly,the activity distance and activity in the open field test were decreased,the gastric mucosal ulcer index was increased significantly,the gastric mucosal function indexes involving GAS level was increased and SS level was decreased in serum,the mRNA expression level of EGFR in gastric mucosa was decreased and the mRNA expression level of MMP3 in gastric mucosa was increased.The serum levels of antioxidant substances SOD and GSH-PX were decreased significantly,and the serum level of oxidation product MDA was increased significantly.The mRNA expression levels of antioxidant genes NRF2,HO-1 and SOD2 in gastric mucosa were significantly decreased.The serum contents and the gastric mucosa mRNA levels of inflammatory factors TNF-α,IL-1α,IL-6 were significantly increased,while the serum content and the gastric mucosa mRNA level of IL-10 were significantly decreased.The differences were statistically significant(P＜0.05 or P＜0.01 or P＜0.001).HE staining showed obvious gastric mucosal injury.Compared with the model group,the above indexes in the acupuncture group and the Omeprazole group were significantly improved(P＜0.05 or P＜0.01 or P＜0.001).HE staining showed that the gastric mucosal injury was significantly reduced.Conclusion Acupuncture at Zusanli-Zhongwan combined matching points can reduce the local oxidative stress and inflammatory response in rats with exercise-induced stress gastric ulcer,reduce gastric mucosal injury,improve the emotional state of rats,and maintain the overall vitality of rats.

Aim To explore the mechanism of modified Wuzi Yanzong pill to reduce testicular toxicity of Tripterygium wilfordii by means of network pharmacolo-gy.Methods The effective chemical composition and target of modified Wuzi Yanzong Pill to reduce testicu-lar toxicity of Tripterygium wilfordii were analyzed by using multiple databases to understand the mechanism of action.Results The first five compounds of modi-fied Wuzi Yanzong pill are quercetin,sucrose,kaempferol,galactose and ellagic acid,respectively.The first five targets were TP53,SRC,EP300,MAPK3,STAT3;KEGG pathway enrichment analysis mainly concentrated in cancer pathway,lipid and atherosclero-sis,hepatitis B,apoptosis,diabetes complications AGE-RAGE signaling pathway,PI3K-Akt signaling pathway and other signaling pathways.Conclusions The ac-tive components of modified Wuzi Yanzong pill can re-duce the testicular toxicity of Tripterygium wilfordii mainly by interfering with TP53,SRC,EP300,MAPK3,STAT3 and other targets,regulating apoptosis,PI3K-Akt signaling pathway,diabetes complications AGE-RAGE signaling pathway,lipid metabolism and other pathways.

Objective To investigate the incidence rate,clinical characteristics,and prognosis of neonatal stroke in Shenzhen,China.Methods Led by Shenzhen Children's Hospital,the Shenzhen Neonatal Data Collaboration Network organized 21 institutions to collect 36 cases of neonatal stroke from January 2020 to December 2022.The incidence,clinical characteristics,treatment,and prognosis of neonatal stroke in Shenzhen were analyzed.Results The incidence rate of neonatal stroke in 21 hospitals from 2020 to 2022 was 1/15 137,1/6 060,and 1/7 704,respectively.Ischemic stroke accounted for 75％(27/36);boys accounted for 64％(23/36).Among the 36 neonates,31(86％)had disease onset within 3 days after birth,and 19(53％)had convulsion as the initial presentation.Cerebral MRI showed that 22 neonates(61％)had left cerebral infarction and 13(36％)had basal ganglia infarction.Magnetic resonance angiography was performed for 12 neonates,among whom 9(75％)had involvement of the middle cerebral artery.Electroencephalography was performed for 29 neonates,with sharp waves in 21 neonates(72％)and seizures in 10 neonates(34％).Symptomatic/supportive treatment varied across different hospitals.Neonatal Behavioral Neurological Assessment was performed for 12 neonates(33％,12/36),with a mean score of(32±4)points.The prognosis of 27 neonates was followed up to around 12 months of age,with 44％(12/27)of the neonates having a good prognosis.Conclusions Ischemic stroke is the main type of neonatal stroke,often with convulsions as the initial presentation,involvement of the middle cerebral artery,sharp waves on electroencephalography,and a relatively low neurodevelopment score.Symptomatic/supportive treatment is the main treatment method,and some neonates tend to have a poor prognosis.

Objective To summarize the distribution characteristics of healthcare-associated infection(HAI)after esophageal cancer surgery,analyze the relevant risk factors for HAI,provide reference for reducing HAI after esophageal cancer surgery,and improve patients'life quality.Methods Clinical data of patients with esophageal cancer who underwent surgery in a hospital from January to December 2022 were analyzed retrospectively.Postope-rative HAI sites and distribution were summarized.Chi-square test,univariate analysis and multivariate analysis were adopted to conduct correlation analysis on the basic characteristics,surgery-related influencing factors,antimi-crobial use,risk factors and the occurrence of HAI in patients during hospitalization period.Results A total of 404 patients underwent esophageal cancer surgery were included in the analysis,among which 102 cases had 118 epi-sodes of HAI,leading to an incidence and a case incidence of HAI of 25.25％and 29.21％respectively.The major infection sites were lower respiratory tract(n=57,48.31％),pleural cavity(n=31,26.27％),and organ space(n=16,13.56％).Multivariate logistic regression analysis showed that age ≥60 years(OR=2.115,95％CI:1.150-3.890),length of hospital stay ≥25 days(OR=8.388,95％CI:4.491-15.667)and duration of postope-rative antimicrobial use ≥10 days(OR=2.885,95％CI:1.506-5.527)were independent risk factors for the oc-currence of postoperative HAI(all P＜0.05).Conclusion The major HAI in patients after esophageal cancer sur-gery is lower respiratory tract infection,and is caused by multiple factors.Patients aged ≥60 years,with a length of hospital stay ≥25 days,and duration of postoperative antimicrobial use ≥10 days are more likely to develop postope-rative HAI.In order to improve the life quality of patients underwent esophageal cancer surgery,it is rec-ommended to further strengthen perioperative management,optimize the nursing quality for patients during hospi-talization,and use antimicrobial agents rationally to reduce the occurrence of HAI.