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.

AIM To establish a UPLC method for the simultaneous content determination of liquiritin,ammonium glycyrrhizate,naringin,neohesperidin,hesperidin,rosmarinic acid,baicalin,wogonoside,baicalein,wogonin and praeruptorin A in Tongxuan Lifei Pills,and to make chemometric investigation.METHODS The analysis was performed on a 30 ℃ thermostatic SVEA C18 column(2.1 mm×150 mm,2.5 μm),with the mobile phase comprising of acetonitrile-0.1％phosphoric acid flowing at 0.5 mL/min in a gradient elution manner,and the detection wavelength was set at 250 nm.Subsequently,cluster analysis,principal component analysis and partial least square discriminant analysis were performed.RESULTS Eleven constituents showed good linear relationships within their own ranges(R2＞0.990 0),whose average recoveries were 90.00％-98.32％with the RSDs of 0.35％-1.89％.Forty batches of samples were clustered into 3 types.Baicalein,baicalin,liquiritin,wogonin,wogonoside and neohesperidin were taken as quality differential markers.CONCLUSION This simple and reproducible method can provide the basis for quality control and evaluation of Tongxuan Lifei Pills.

Objective:To investigate the differences between high-frequency ultrasound-guided manual detorsion combined with surgery(MD+S)and surgery alone in the treatment of testicular torsion,and to provide some new evidence for the timely diagno-sis and treatment of the disease.Methods:We retrospectively analyzed the clinical data on 134 cases of unilateral testicular torsion within 48 hours treated in our hospital by MD+S or by surgery alone from January 2015 to May 2022.We statistically analyzed the age distribution,and duration and degrees of testicular torsion,followed by comparison between the two groups.Results:In the 134 ca-ses,the median age of onset was 15(13-19)years old,the median onset-to-visit time was 15(8-25)hours,and the median de-gree of torsion was 360°(180°-1080°).Of the total number of patients,21 underwent testicular excision and the other 113 were treated with the testis preserved,with no statistically significant difference in age distribution between the two groups(P＞0.05),and a higher rate of testis resection in those with longer duration and greater angle of torsion(P＜0.05).Totally,33 of the patients were assigned to the MD+S group and 101 to the surgery alone group.According to the actual clinical conditions and excluding those with torsion time longer than 24 hours and torsion angle greater than 720 °,28 of the patients underwent ultrasound-guided MD+S(with 1 case of testis resection,3.6％),and 68 received surgery alone(with 7 cases of testis resection,10.3％).The rate of testis resection was higher in the surgery alone than that in the MD+S group,but with no statistically significant difference between the two groups(P＞0.05),which was considered to be related to the small sample size in this study.Conclusion:The popularization of testicular torsion knowledge can shorten the onset-to-visit time,and reasonable manual detorsion before emergency surgery can reduce the rate of testis resection.

Protein-protein interactions play an extremely important role in the biochemical functions of cells,and in-depth analysis of protein interactions is the key to understanding cellular life activities.In this study,we systematically mined the interacting proteins of Golgi protein 73(GP73)using classical immunoprecipitation combined with mass spectrometry,and sought to further analyze the molecular func-tion of GP73.Hepatocellular carcinoma cell line HepG2 was selected,and a stable cell line overexpress-ing GP73-3Flag was constructed using lentiviral infection technology.A total of 78 high-confidence GP73 interacting proteins were identified by immunoprecipitation coupled with mass spectrometry.Bioinformat-ics analyses suggested that GP73 interacted with nearly 40 cytosolic proteins and participated in the bio-logical processes of RNA transport,splicing,and translation.Further immunofluorescence and cytosolic protein isolation experiments confirmed the cytosolic localization of GP73 in a variety of tumor cells.Based on the 78 interacting proteins,we further screened protein interaction networks related to mRNA splicing and verified the existence of interactions between GP73 and seven proteins,including HNRN-PH3,SMN1,RBM14,andNCBP1,by co-immunoprecipitation experiments.In addition,minigene spli-cing assay results indicated that GP73 inhibited the splicing efficiency of pre-mRNA by cells.This study contributes to the expansion of knowledge regarding the function of GP73 and aids in elucidating its criti-cal role in cell biology and its potential association with diseases.

Protein-protein interactions play an extremely important role in the biochemical functions of cells,and in-depth analysis of protein interactions is the key to understanding cellular life activities.In this study,we systematically mined the interacting proteins of Golgi protein 73(GP73)using classical immunoprecipitation combined with mass spectrometry,and sought to further analyze the molecular func-tion of GP73.Hepatocellular carcinoma cell line HepG2 was selected,and a stable cell line overexpress-ing GP73-3Flag was constructed using lentiviral infection technology.A total of 78 high-confidence GP73 interacting proteins were identified by immunoprecipitation coupled with mass spectrometry.Bioinformat-ics analyses suggested that GP73 interacted with nearly 40 cytosolic proteins and participated in the bio-logical processes of RNA transport,splicing,and translation.Further immunofluorescence and cytosolic protein isolation experiments confirmed the cytosolic localization of GP73 in a variety of tumor cells.Based on the 78 interacting proteins,we further screened protein interaction networks related to mRNA splicing and verified the existence of interactions between GP73 and seven proteins,including HNRN-PH3,SMN1,RBM14,andNCBP1,by co-immunoprecipitation experiments.In addition,minigene spli-cing assay results indicated that GP73 inhibited the splicing efficiency of pre-mRNA by cells.This study contributes to the expansion of knowledge regarding the function of GP73 and aids in elucidating its criti-cal role in cell biology and its potential association with diseases.

Aim To investigate the effects of the fangchinoline derivative LYY-32 on the biological prop-erties of the BLM642-1290 DNA helicase,in order to lay a foundation for further research on its antitumor activity.Methods Fluorescence polarization assay,malachite green-phosphate and ammonium molybdate colorime-try,and fluorescein-labeled DNA gel electrophoresis experiments were conducted to study the effects of fangchinoline derivative LYY-32 on the DNA binding activity,ATPase activity,and DNA unwinding activity of BLM642-1290 DNA helicase.The effects of LYY-32 on the DNA unwinding activity of DNA helicase in cells were studied using fluorescent techniques and time-lapse microscopy.Ultraviolet spectral scanning was used to investigate the effects of LYY-32 on the confor-mation of the BLM642-1290 DNA helicase.Results At a concentration of 10 μmol·L-1,the inhibition rate of LYY-32 on BLM642-1290 DNA helicase binding to dsDNA was 53.17％.At a concentration of 5 μmol·L-1,the inhibition rate of LYY-32 on BLM642-1290 DNA helicase binding to ssDNA was 88.49％.The inhibition rate of LYY-32 on the ATPase activity of BLM642-1290 DNA he-licase was 89.3％at a concentration of 50 μmol·L-1.When the concentration of LYY-32 exceeded 5μmol·L-1,its inhibition rate on the DNA unwinding activity of BLM642-1290 DNA helicase was 100％.LYY-32 also significantly inhibited the DNA unwinding ac-tivity of DNA helicase in cells.However,LYY-32 had no effect on the conformation of BLM642-1290 DNA heli-case.Conclusion The DNA binding activity,AT-Pase activity,and DNA unwinding activity of BLM642-1290 DNA helicase could be significantly inhibi-ted by the fangchinoline derivative LYY-32.

Objective:To construct and validate a competency-oriented entrustable professional activities (EPAs)-Competency-Milestones system for assessment of laparoscopic skills (ESALS).Methods:A research team composed of 15 members from five medical institutions was established. Taking the Staged Training and Assessment of Laparoscopic Skills program as the basis for EPAs, ESALS was constructed through scoping review and behavioral event interviews and the use of the Kawakita Jiro method. ESALS was applied to evaluate 49 trainees and 10 specialists (including 5 novices and 5 experts) on basic and advanced laparoscopic skills, respectively, in comparison with two other assessment tools—the Training and Assessment of Basic Laparoscopic Techniques (TABLT) and the Global Operative Assessment of Laparoscopic Skills (GOALS). Perform Mann Whitney U test using SPSS 23.0 software, and use Spearman coefficient for correlation analysis.Results:Through reviewing 13 literuature articles and interviewing 10 senior surgeons, the ESALS was developed, comprising 10 EPAs, 8 dimensions of competency characteristics, and 5 entrustable levels. In the basic skills evaluation, the ESALS score was significantly positively correlated with the TABLT score ( R=0.881, P<0.001). In the advanced skills evaluation, significant differences were observed between the novice and expert groups in all the ESALS competency scores (all P<0.05), while no difference was detected in the GOALS score of tissue handling ability. Conclusions:ESALS provides comprehensive evaluation, detailed standards, and precise feedback, with comparable efficacy to conventional tools. Future work should focus on expanding sample size to verify its generalizability and developing an electronic tool to enhance application efficiency.

Objective Postdoctoral fellows are a crucial force in hospital scientific research and serve as a"talent pool"for high-level young professionals.Exploring optimized pathways for postdoctoral training in university-affiliated tertiary hospitals under the high-quality development context is of great significance.Methods Taking a tertiary hospital in Guangzhou as the re-search subject,this study analyzed the hospital's postdoctoral management implementation measures,recruitment status,scientif-ic research output,and training outcomes over the past five years(2020-2024).Combined with policy and literature analysis,shortcomings in postdoctoral training were summarized,and a conceptual"Trinity"collaborative training mechanism involving the"hospital-department-postdoctoral fellow"was proposed.Results The retention rate of postdoctoral fellows increased to 42％,the number of provincial/ministerial-level and above research projects grew by 1.5 times,and the number of newly enrolled post-doctoral fellows in 2024 more than doubled compared to 2020.However,challenges remain,including insufficient high-quality candidates,inadequate guidance and cultivation by supervisors,lagging achievement transformation,imperfect assessment sys-tems,and incomplete incentive and support measures.Conclusion Postdoctoral fellows are a vital force in hospital scientific re-search.Constructing an effective collaborative training mechanism is essential.Through innovations in management and training models,departmental and supervisor team building,and diversified incentives and support mechanisms,multi-party collaboration and systematic integration should be pursued.Further exploration of the"Trinity"training mechanism will deepen the alignment of postdoctoral training with clinical needs and disciplinary development,thereby promoting high-quality hospital development.

AIM To establish a UPLC method for the simultaneous content determination of liquiritin,ammonium glycyrrhizate,naringin,neohesperidin,hesperidin,rosmarinic acid,baicalin,wogonoside,baicalein,wogonin and praeruptorin A in Tongxuan Lifei Pills,and to make chemometric investigation.METHODS The analysis was performed on a 30 ℃ thermostatic SVEA C18 column(2.1 mm×150 mm,2.5 μm),with the mobile phase comprising of acetonitrile-0.1％phosphoric acid flowing at 0.5 mL/min in a gradient elution manner,and the detection wavelength was set at 250 nm.Subsequently,cluster analysis,principal component analysis and partial least square discriminant analysis were performed.RESULTS Eleven constituents showed good linear relationships within their own ranges(R2＞0.990 0),whose average recoveries were 90.00％-98.32％with the RSDs of 0.35％-1.89％.Forty batches of samples were clustered into 3 types.Baicalein,baicalin,liquiritin,wogonin,wogonoside and neohesperidin were taken as quality differential markers.CONCLUSION This simple and reproducible method can provide the basis for quality control and evaluation of Tongxuan Lifei Pills.

Aim To identify the underlying target of bullatine A(BA)against rheumatoid arthritis(RA)u-sing limited proteolysis-small molecule mapping(LiP-SMap)drug target proteomics and to provide a scientif-ic basis for clinical application of Aconiti brachypodi Radix in the treatment of RA.Methods LiP-SMap drug target proteomics was employed to perform bioin-formatics analysis for comparing and validating the dif-ferential protein expression after BA intervention.A collagen-induced arthritis(CIA)model was estab-lished in DBA/1 mice using bovine type Ⅱ collagen.The mice were then divided into the CIA model group,methotrexate-positive control group(MTX group),and BA groups(10 mg·kg-1 and 20 mg·kg-1)based on their clinical scores.After drug intervention,the thera-peutic efficacy against RA was assessed by joint index scores and foot thickness measurements.Histopatholog-ical changes in the arthritic joints of CIA mice were e-valuated using hematoxylin and eosin(HE)staining.Enzyme-linked immunosorbent assay(ELISA)was employed to detect inflammatory cytokines interleukin-17(IL-17)and total IgG and IgG3 anti-collagen-spe-cific antibodies levels from the serum of CIA mice.Flow cytometry was used to detect the expression levels of intracellular Th17 cells(IL-17+CD4+T cells)and Th1 cells(IFN-γ+CD4+T cells).Fluorescent quanti-tative PCR was performed to detect the expression of genes related to differential proteins.Results The proteomic analysis identified Serpinb1a as a protein with strong binding affinity to BA,and KEGG enrich-ment analysis indicated IL-17 signaling pathway was a crucial pathway of BA in against RA.BA treatment significantly reduced clinical scores and foot thickness,improved local arthritis symptoms in CIA mice,and al-leviated inflammatory cell infiltration into arthritic joints(P＜0.05).Differential protein validation re-sults showed that BA had strong affinity with Serpinb1a(-5.92 kJ·mol-1)and downregulated the expres-sion of Serpinb1a mRNA.Furthermore,the administra-tion of BA markedly reduced serum IL-17 A levels from CIA mice,inhibited the expression of intracellular IL-17 A and IFN-γ cytokines in splenic CD4+T cells(P＜0.05),and significantly downregulated the transcrip-tional expression of IL-17F(P＜0.05).Conclusion BA exhibits therapeutic effects on collagen-induced arthritis,and its mechanism of action may involve the regulation of Serpinb1a and the IL-17 signaling path-way.