ObjectiveProtein-protein interactions (PPIs) are fundamental to the execution of biological functions within living cells. However, traditional biochemical methods, such as co-immunoprecipitation (Co-IP), often fail to capture transient, weak, or membrane-associated interactions due to the stringent detergent requirements for cell lysis. Proximity labeling (PL) has emerged in recent years as a transformative technology for mapping the proteomes of specific subcellular compartments and identifying dynamic interactomes in situ. Golgi protein 73 (GP73, also known as GOLPH2), a resident type II Golgi transmembrane protein, is a well-recognized clinical biomarker for liver diseases, including hepatocellular carcinoma (HCC). Despite its clinical significance, the comprehensive physiological and pathological functions of GP73 remain partially understood. This study aims to establish an APEX2-mediated proximity labeling system specifically targeting GP73 to map its interactome in a living cellular environment, thereby providing new insights into its molecular roles and regulatory mechanisms. MethodsTo achieve spatial specificity, we first constructed a stable cell line expressing a fusion protein consisting of GP73 and the engineered soybean peroxidase APEX2. The localization of the GP73-APEX2 fusion protein was validated to ensure it correctly targeted the Golgi apparatus. The proximity labeling reaction was initiated by incubating the cells with biotin-phenol (BP) for 30 min, followed by a brief (1 min) treatment with1 mmol/L hydrogen peroxide (H₂O₂). This catalytic reaction converts BP into highly reactive, short-lived biotin-phenoxyl radicals that covalently attach to endogenous proteins within a small labeling radius of the GP73-APEX2 enzyme. Subsequently, the cells were quenched, and biotinylated proteins were enriched using high-affinity streptavidin-coated magnetic beads. The captured “neighbor” proteins were subjected to on-bead digestion and analyzed via liquid chromatography-tandem mass spectrometry (LC-MS/MS) for high-throughput identification. Rigorous bioinformatics analysis, including Gene Ontology (GO) enrichment, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, and protein-protein interaction network mapping, was performed to interpret the biological significance of the identified candidates. ResultsOur results demonstrate the successful establishment of a robust and sensitive APEX2-based proximity labeling system for GP73. We identified a total of 95 high-confidence interacting proteins that were significantly enriched in the GP73 proximity proteome compared to control groups. Bioinformatics analysis revealed that these interactors were predominantly associated with biological processes such as vesicular transport, protein localization, and, most notably, molecular functions related to “ribosome binding” and “translation regulation”. This suggested an unexpected role for the Golgi-resident GP73 in the cellular translation machinery. To validate these findings, we performed targeted biochemical assays which confirmed a direct interaction between GP73 and the subunits of the eukaryotic translation initiation factor 3 (eIF3) complex, specifically EIF3G and EIF3I. Furthermore, functional validation using the surface sensing of translation (SUnSET) assay—a non-radioactive method to monitor protein synthesis—revealed that the overexpression of GP73 significantly promoted global protein translation levels in the cell, whereas its depletion or inhibition resulted in reduced translation efficiency. ConclusionThis study successfully utilized APEX2-mediated proximity labeling to provide the first systematic map of GP73 interactome in living cells. Our findings uncover a novel, unconventional function of GP73 as a regulator of cellular protein translation, likely mediated through its interaction with the eIF3 complex. This discovery significantly broadens our understanding of the biological roles of GP73 beyond its traditional function in the Golgi apparatus and suggests that it may act as a bridge between Golgi-related trafficking and the protein synthesis machinery. Furthermore, the technical framework established in this study provides a valuable template for investigating other complex organelle-associated protein networks and resolving transient macromolecular interactions in various physiological and pathological contexts.

Establishing a one-stop diagnosis and treatment mode centered on patients and linked by diseases is of great significance for optimizing the medical process and improving the medical experience. In March 2024, a tertiary hospital integrated pediatric outpatient and emergency resources, established a pediatric diagnosis and treatment island through reasonable department settings, strengthened talent team construction, optimized diagnosis and treatment processes, and established supporting guarantee mechanisms. It was officially put into use in June of the same year, providing one-stop diagnosis and treatment services for children and achieving the goal of " not leaving the island for minor illnesses and not leaving the hospital for major illnesses". Before the operation of island (January May 2024), the complaint rate and waiting time for pediatric outpatient and emergency department were 39 cases per 100 000 patients and 15 to 30 minutes, respectively; After operation (June August 2024), the complaint rate and waiting time decreased to 17 cases per 100 000 people and 10 to 20 minutes respectively; The average monthly comprehensive income of outpatient and emergency departments increased by 33%. The pediatric diagnosis and treatment island mode could assist in the sustainable high-quality development of pediatrics in hospital, and provide references for optimizing outpatient and emergency department management in other tertiary public hospitals. In the future, we should further enrich the service content of the island and strengthen information technology construction.

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.

Isoflavones which mainly distributed in leguminous plants have plenty of health benefits.Isoflavone synthase(IFS)is a membrane-associated cytochrome P450 enzyme(CYP450)which carries out the unique aryl-ring migration and hydroxylation.So far,few crystal structures of plant P450s have been obtained.We determined the crystal structure of IFS from Medicago truncatula at 1.9 ? by MAD method using a selenomethionine substituted crystal and conducted molecular docking and mutagenesis study.The structure of IFS complexed with imidazole exhibits the helix Ⅰa-loop-helix Ⅰβ motif which cor-responds to helix Ⅰ of other P450s.Compared with structures of common P450s,IFS/imidazole structure contains an extra domain,i.e.,the γ-domain.The structure reveals a homodimer in which the γ-domain of one molecule interacts with the β-domain of another.The plane of heme group makes an angle of ap-proximately 40° with the helix Ⅰa-loop-helix Ⅰβ motif.Molecular docking combined with mutagenesis study suggested that Trp-128 and Asp-300 might play important roles in substrate binding and recogni-tion.Phe-301,Ser-303 and Gly-305 from the helix Ⅰa-loop-helix Ⅰβ motif may play important roles in the aryl-ring migration.These novel structural features reveal insights into the unique reaction mechanism of IFS and provide a basis for engineering IFS in leguminous crops for health purpose.

In recent years,the intensification of dairy farming has significantly improved production efficiency but has also led to a rise in the incidence of metabolic diseases.Conditions such as keto-sis,fatty liver,and hypocalcemia pose serious threats to dairy cattle health and productivity.These diseases not only profoundly affect individual physiological function but also impose considerable economic pressures and challenges on farm management.As research advances,exosomes have e-merged as a novel intercellular signaling molecule,showing unique potential in regulating dairy cattle's nutritional metabolism.Studies suggest that exosomes hold promise as biomarkers for dis-ease and can even serve as carriers for disease detection and prevention.Acting as a crucial mediator of intercellular communication,exosomes play an important role in modulating the metabolic processes of dairy cattle.This review aims to systematically explore the role of exosomes in bovine nutritional metabolism and to provide new perspectives and theoretical support for their potential as tools for diagnosing,treating,and preventing metabolic diseases in dairy cattle,thus advancing research and practice in this field.

Objective To measure and analyze anatomic parameters of resected distal femurs and proximal tibias in Kaschin-Beck disease(KBD)and osteoarthritic(OA)knees which fit for total knee arthroplasty(TKA),so as to provide basis for designing suitable knee prosthesis for KBD patients.Methods A total of 154 knees(75 KBD and 79 OA)fitting for TKA underwent three-dimensional reconstruction;resection of distal femurs and proximal tibias was simulated during TKA.We measured the distal femoral mediolateral(fML),lateral anteroposterior(fLAP),medial anteroposterior(fMAP),medial condylar width(fMCW),lateral condylar width(fLCW)and fML/fLAP aspect ratio,proximal tibial mediolateral(tML),middle anteroposterior(tAP),medial anteroposterior(tMAP),lateral anteroposterior(tLAP)dimension,and tML/tAP aspect ratio to compare the morphometric differences between KBD and OA knees.Results The measured anatomic parameters of resected distal femurs and proximal tibias in both male and female patients of KBD group were smaller than those of OA knees(P＜0.01).We also found that KBD group had larger distal femur fML/fLAP and proximal tibia tML/tAP aspect ratios than those of OA knees(P＜0.01).This indicated that under a given AP dimension,KBD knees need an oval-shaped prosthesis with a wider ML length and more spherical-shaped prosthesis with relatively narrow ML dimensions in OA knees.Conclusion The anatomy of distal femurs and proximal tibias shows significant differences in size and shape between KBD and OA knees,which provides theoretical basis for designing proper knee prosthesis for KBD patients.

Objective The aim of this study is to analyze the expression level of cell-free DNA(cf-DNA),a biomarker of neutrophil extracellular traps(NETs),in children with Mycoplasma pneumoniae pneumonia(MPP),and to explore the predictive efficacy of cf-DNA(as a marker of NETs)for the severity of MPP in these children.Methods A total of 115 children with MPP were prospectively selected as the MPP group.Based on the disease severity,the MPP group was categorized into the mild group(n=75)and the severe group(n=40).During the same period,50 healthy children undergoing physical examinations were selected as the control group.The levels of serum cf-DNA in the MPP group and the control group,as well as the levels of C-reactive protein(CRP),D-dimer,lactate dehydrogenase(LDH),interleukin-6(IL-6),interferon-γ(IFN-γ),and tumor necrosis factor-α(TNF-α)in the MPP group were detected.The differences in the levels of serum cf-DNA and related inflammatory factors among the groups were compared,and the role of serum cf-DNA in evaluating the severity of MPP was analyzed.Results The level of serum cf-DNA in children of the MPP group was notably higher than that in the control group,with a more significant elevation observed in the severe group(P<0.05).The levels of CRP,D-dimer,LDH,IL-6,IFN-γ,and TNF-α were all higher in the severe group than in the mild group(P<0.05).Multivariate logistic regression analysis showed that the increased levels of serum cf-DNA,CRP,and IL-6 were closely related to the severity of MPP(P<0.05).The results of receiver operating characteristic(ROC)curve analysis showed that the area under the curve(AUC)of the combination of serum cf-DNA,CRP,and IL-6 for predicting severe MPP was 0.981,which was higher than that of each index alone(P<0.05).Conclusions Serum cf-DNA(as a marker of NETs)is closely related to the severity of MPP in children.The combined detection of cf-DNA,CRP,and IL-6 is more beneficial for assessing the severity of MPP in children.

In recent years,the intensification of dairy farming has significantly improved production efficiency but has also led to a rise in the incidence of metabolic diseases.Conditions such as keto-sis,fatty liver,and hypocalcemia pose serious threats to dairy cattle health and productivity.These diseases not only profoundly affect individual physiological function but also impose considerable economic pressures and challenges on farm management.As research advances,exosomes have e-merged as a novel intercellular signaling molecule,showing unique potential in regulating dairy cattle's nutritional metabolism.Studies suggest that exosomes hold promise as biomarkers for dis-ease and can even serve as carriers for disease detection and prevention.Acting as a crucial mediator of intercellular communication,exosomes play an important role in modulating the metabolic processes of dairy cattle.This review aims to systematically explore the role of exosomes in bovine nutritional metabolism and to provide new perspectives and theoretical support for their potential as tools for diagnosing,treating,and preventing metabolic diseases in dairy cattle,thus advancing research and practice in this field.

Background/Aims: Treatment indications for patients with chronic hepatitis B (CHB) remain contentious, particularly for patients with mild alanine aminotransferase (ALT) elevation. We aimed to evaluate treatment effects in this patient population. Methods: This rollover study extended a placebo-controlled trial that enrolled non-cirrhotic patients with CHB and ALT levels below two times the upper limit of normal. Following 3 years of randomized intervention with either tenofovir disoproxil fumarate (TDF) or placebo, participants were rolled over to open-label TDF for 3 years. Liver biopsies were performed before and after the treatment to evaluate histopathological changes. Virological, biochemical, and serological outcomes were also assessed (NCT02463019). Results: Of 146 enrolled patients (median age 47 years, 80.8% male), 123 completed the study with paired biopsies. Overall, the Ishak fibrosis score decreased in 74 (60.2%), remained unchanged in 32 (26.0%), and increased in 17 (13.8%) patients (p<0.0001). The Knodell necroinflammation score decreased in 58 (47.2%), remained unchanged in 29 (23.6%), and increased in 36 (29.3%) patients (p=0.0038). The proportion of patients with an Ishak score ≥ 3 significantly decreased from 26.8% (n=33) to 9.8% (n=12) (p=0.0002). Histological improvements were more pronounced in patients switching from placebo. Virological and biochemical outcomes also improved in placebo switchers and remained stable in patients who continued TDF. However, serum HBsAg levels did not change and no patient cleared HBsAg. Conclusions In CHB patients with minimally raised ALT, favorable histopathological, biochemical, and virological outcomes were observed following 3-year TDF treatment, for both treatment-naïve patients and those already on therapy.

Background/Aims: Treatment indications for patients with chronic hepatitis B (CHB) remain contentious, particularly for patients with mild alanine aminotransferase (ALT) elevation. We aimed to evaluate treatment effects in this patient population. Methods: This rollover study extended a placebo-controlled trial that enrolled non-cirrhotic patients with CHB and ALT levels below two times the upper limit of normal. Following 3 years of randomized intervention with either tenofovir disoproxil fumarate (TDF) or placebo, participants were rolled over to open-label TDF for 3 years. Liver biopsies were performed before and after the treatment to evaluate histopathological changes. Virological, biochemical, and serological outcomes were also assessed (NCT02463019). Results: Of 146 enrolled patients (median age 47 years, 80.8% male), 123 completed the study with paired biopsies. Overall, the Ishak fibrosis score decreased in 74 (60.2%), remained unchanged in 32 (26.0%), and increased in 17 (13.8%) patients (p<0.0001). The Knodell necroinflammation score decreased in 58 (47.2%), remained unchanged in 29 (23.6%), and increased in 36 (29.3%) patients (p=0.0038). The proportion of patients with an Ishak score ≥ 3 significantly decreased from 26.8% (n=33) to 9.8% (n=12) (p=0.0002). Histological improvements were more pronounced in patients switching from placebo. Virological and biochemical outcomes also improved in placebo switchers and remained stable in patients who continued TDF. However, serum HBsAg levels did not change and no patient cleared HBsAg. Conclusions In CHB patients with minimally raised ALT, favorable histopathological, biochemical, and virological outcomes were observed following 3-year TDF treatment, for both treatment-naïve patients and those already on therapy.