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.

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.

Tailored lipid nanoparticles (LNPs)-mediated small interfering RNA (siRNA) nanomedicines show promise in treating liver disease, such as acute liver injury (ALI) and non-alcoholic steatohepatitis (NASH). However, constructing LNPs that address biosafety concerns, ensure efficient delivery, and target specific hepatic subcellular fractions has been challenging. To evade above obstacles, we develop three novel self-degradable "gemini-like" ionizable lipids (SS-MA, SS-DC, SS-MH) by incorporating disulfide bonds and modifying the length of ester bond and tertiary amino head. Our findings reveal that the disulfide-bond-bridged LNPs exhibit reduction-responsive drug release, improving both biosafety and siRNA delivery efficiency. Furthermore, the distance of ester bond and tertiary amino head significantly influences the LNPs' pK _a, thereby affecting endosomal escape, hemolytic efficiency, absorption capacity of ApoE, uptake efficiency of hepatocytes and liver accumulation. We also develop the modified-mannose LNPs (M-LNP) to target liver macrophages specifically. The optimized M-MH_LNP@TNFα exhibits potential in preventing ALI by decreasing tumor necrosis factor α (TNFα) levels in the macrophages, while MH_LNP@DGAT2 could treat NASH by selectively degrading diacylglycerol O-acyltransferase 2 (DGAT2) in the hepatocytes. Our findings provide new insights into developing novel highly effective and low-toxic "gemini-like" ionizable lipids for constructing LNPs, potentially achieving more effective treatment for hepatic diseases.

Gastric cancer remains one of the most prevalent and lethal malignancies of the digestive tract worldwide,underscoring the urgent need for more effective targeted therapeutic strategies.Poly(ADP-ri-bose)polymerase(PARP)inhibitors have demonstrated remarkable efficacy in tumors with homologous recombination repair(HRR)deficiency;however,their clinical application in gastric cancer remains limited.Clinical evidence suggests that patients harboring Helicobacter pylori infection in combination with HRR gene mutations exhibit a significantly elevated risk of developing gastric cancer,thereby supporting the potential benefit of PARP inhibition in this setting.In this study,a kinase inhibitor library was screened in combination with the PARP inhibitor olaparib in gastric cancer cells.And we identify the cy-clin-dependent kinase 8/19(CDK8/19)inhibitor Senexin A as a compound that synergistically enhances the cytotoxic effect of PARP inhibition(P<0.05).Phenotypic validation using CCK-8 and colony for-mation assays demonstrated that the combination treatment significantly suppressed cellular proliferation and clonogenic potential compared to either monotherapy(P<0.0001).Mechanistically,alkaline comet assays revealed a significant increase in DNA damage in the combination treatment group relative to either single-agent group(P<0.0001),suggesting that the synergistic effect results from the exacerbation of DNA damage via impaired DNA repair mechanisms.In addition,treatment with CDK8/19 inhibitors a-lone markedly increased the formation of γH2AX and 53BP1 foci in irradiated gastric cancer cells(P<0.0001),indicating inhibition of DNA damage repair pathways.Transcriptome sequencing further re-vealed that CDK8/19 inhibition impacts critical cellular pathways,including DNA repair,cell cycle reg-ulation,and RNA splicing.Co-immunoprecipitation assays confirmed that inhibition of CDK8/19 kinase activity significantly reduces the phosphorylation level of PARP1,suggesting a potential regulatory inter-action.Immunohistochemical analysis of tumor and adjacent non-tumor tissues from gastric cancer pa-tients demonstrated that CDK8 is significantly overexpressed in tumor tissues,supporting its potential as both a prognostic biomarker and a therapeutic target.Collectively,this study elucidates a mechanistic ba-sis by which CDK8/19 inhibition enhances the sensitivity of gastric cancer cells to PARP inhibitors.These findings provide a strong rationale for the combined use of CDK8/19 and PARP inhibitors as a tar-geted therapeutic strategy and offer promising translational implications for advancing personalized medi-cine in gastric cancer treatment.

This study was aimed at understanding the prevalence and drug resistance status of Salmonella of waterfowl ori-gin in the Guangdong region in the past decade,to guide prevention and control efforts.The drug-sensitive paper slide method was used to conduct drug susceptibility testing on 314 waterfowl-originating Salmonella strains isolated from 238 waterfowl farms in the Guangdong region from 2013 to 2023.The isolated Salmonella strains were most resistant to penicillin,amoxicil-lin,cefradine,and cefazolin in the β-lactam group;sulphadoxine dimethylpyrimidine in the sulphonamide group;and tetracy-cline in the tetracycline group.The resistance rates ranged from 73.57％to 89.49％.The highest sensitivity was observed to amikacin,gentamicin,and kanamycin in the aminoglycoside group,and norfloxacin in the quinolone group,with susceptibility rates all exceeding 50％.The 280 strains of Salmonella showed multi-drug resistance to six classes of antimicrobial drugs and high resistance(as much as 60.83％)to five drug classes.Correlation analysis revealed the highest correlations for florfenicol with gentamicin,and for amoxicillin with penicillin(r=0.650 for both),followed by gentamicin with kanamycin(r=0.620).Salmonella resistance in waterfowl in Guangdong Province was generally severe and showed a complex pattern of drug resist-ance.Detection of waterfowl pathogens should be strengthened to prevent the spread of drug-resistant bacteria and support ra-tional use of antibiotics.This work provides a reference for Salmonella prevention and control in waterfowl farms.

This study aims to explore the pharmacodynamic material basis of Jinbei Oral Liquid(JBOL) against idiopathic pulmonary fibrosis(IPF) based on serum pharmacochemistry and network pharmacology. The ultra-high performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry(UHPLC-Q-TOF-MS/MS) technology was employed to analyze and identify the components absorbed into rat blood after oral administration of JBOL. Combined with network pharmacology, the study explored the pharmacodynamic material basis and potential mechanism of JBOL against IPF through protein-protein interaction(PPI) network construction, "component-target-pathway" analysis, Gene Ontology(GO) functional enrichment, and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment analysis. First, a total of 114 compounds were rapidly identified in JBOL extract according to the exact relative molecular mass, fragment ions, and other information of the compounds with the use of reference substances and a self-built compound database. Second, on this basis, 70 prototype components in blood were recognized by comparing blank serum with drug-containing serum samples, including 28 flavonoids, 25 organic acids, 4 saponins, 4 alkaloids, and 9 others. Finally, using these components absorbed into blood as candidates, the study obtained 212 potential targets of JBOL against IPF. The anti-IPF mechanism might involve the action of active ingredients such as glycyrrhetinic acid, cryptotanshinone, salvianolic acid B, and forsythoside A on core targets like AKT1, TNF, and ALB and thereby the regulation of multiple signaling pathways including PI3K/AKT, HIF-1, and TNF. In conclusion, JBOL exerts the anti-IPF effect through multiple components, targets, and pathways. The results would provide a reference for further study on pharmacodynamic material basis and pharmacological mechanism of JBOL.
Drugs, Chinese Herbal/pharmacokinetics* ; Animals ; Tandem Mass Spectrometry ; Network Pharmacology ; Rats ; Chromatography, High Pressure Liquid ; Rats, Sprague-Dawley ; Male ; Idiopathic Pulmonary Fibrosis/metabolism* ; Humans ; Administration, Oral ; Protein Interaction Maps/drug effects* ; Signal Transduction/drug effects*

Gastric cancer remains one of the most prevalent and lethal malignancies of the digestive tract worldwide,underscoring the urgent need for more effective targeted therapeutic strategies.Poly(ADP-ri-bose)polymerase(PARP)inhibitors have demonstrated remarkable efficacy in tumors with homologous recombination repair(HRR)deficiency;however,their clinical application in gastric cancer remains limited.Clinical evidence suggests that patients harboring Helicobacter pylori infection in combination with HRR gene mutations exhibit a significantly elevated risk of developing gastric cancer,thereby supporting the potential benefit of PARP inhibition in this setting.In this study,a kinase inhibitor library was screened in combination with the PARP inhibitor olaparib in gastric cancer cells.And we identify the cy-clin-dependent kinase 8/19(CDK8/19)inhibitor Senexin A as a compound that synergistically enhances the cytotoxic effect of PARP inhibition(P<0.05).Phenotypic validation using CCK-8 and colony for-mation assays demonstrated that the combination treatment significantly suppressed cellular proliferation and clonogenic potential compared to either monotherapy(P<0.0001).Mechanistically,alkaline comet assays revealed a significant increase in DNA damage in the combination treatment group relative to either single-agent group(P<0.0001),suggesting that the synergistic effect results from the exacerbation of DNA damage via impaired DNA repair mechanisms.In addition,treatment with CDK8/19 inhibitors a-lone markedly increased the formation of γH2AX and 53BP1 foci in irradiated gastric cancer cells(P<0.0001),indicating inhibition of DNA damage repair pathways.Transcriptome sequencing further re-vealed that CDK8/19 inhibition impacts critical cellular pathways,including DNA repair,cell cycle reg-ulation,and RNA splicing.Co-immunoprecipitation assays confirmed that inhibition of CDK8/19 kinase activity significantly reduces the phosphorylation level of PARP1,suggesting a potential regulatory inter-action.Immunohistochemical analysis of tumor and adjacent non-tumor tissues from gastric cancer pa-tients demonstrated that CDK8 is significantly overexpressed in tumor tissues,supporting its potential as both a prognostic biomarker and a therapeutic target.Collectively,this study elucidates a mechanistic ba-sis by which CDK8/19 inhibition enhances the sensitivity of gastric cancer cells to PARP inhibitors.These findings provide a strong rationale for the combined use of CDK8/19 and PARP inhibitors as a tar-geted therapeutic strategy and offer promising translational implications for advancing personalized medi-cine in gastric cancer treatment.

OBJECTIVE: To analyze the clinical and genetic features of a child with Primary ciliary dyskinesia (PCD) due to compound heterozygous variants of the CCDC39 gene and a 22q11.21 deletion, and to explore the potential role of the two types of variants in the formation of complex phenotypes. METHODS: A child presented at the Shanxi Children's Hospital in March 2025 due to multiple congenital anomalies was selected as the study subject. Peripheral blood samples were taken from the child and her parents and subjected to whole-exome sequencing (WES). Candidate variants were verified by Sanger sequencing. Effect of splicing variant was predicted using SpliceAI, and pathogenicity was assessed based on the ACMG guidelines. Copy number variation (CNV) analysis was also performed. This study has been approved by the Medical Ethics Committee of the Hospital (Ethics No.: IRB-WZ-2025-019). RESULTS: The patient has exhibited multiple features including severe pneumonia, bronchiectasis, localized pulmonary emphysema, scoliosis, tetralogy of Fallot, and atrial septal defect. Genetic testing revealed that she has harbored compound heterozygous variants of the CCDC39 gene, namely c.1167+1G>A and c.1009A>T, which were inherited from her father and mother, respectively, with the latter being a novel likely pathogenic variant. In addition, a heterozygous deletion of approximately 708 kb at 22q11.21 was detected. CONCLUSION The coexistence of CCDC39 gene variants and a 22q11.21 deletion may underlay the development of complex clinical phenotypes in this child.
Humans ; Female ; Chromosomes, Human, Pair 22/genetics* ; Chromosome Deletion ; DNA Copy Number Variations/genetics* ; Child ; Ciliary Motility Disorders/genetics* ; Exome Sequencing

Objective To investigate the bidirectional causal relationship between circulating amino acid levels and the risk of myasthenia gravis(MG)using Mendelian randomization(MR).Methods A two-sample Mendelian randomization a-nalysis was conducted using publicly available genome-wide association study(GWAS)genetic data,with validation from GWAS data from different sources to assess the robustness of the results.Five models were used for the two-sample bidirectional MR anal-ysis,and odds ratios(OR)were calculated to evaluate the causal relationship between the levels of nine circulating amino acids and MG risk.Sensitivity analyses,heterogeneity tests,and pleiotropy tests were performed to assess the robustness of the results.The causal effect estimated by the inverse variance weighted(IVW)method was the primary result,and the IVW-estimated causal effects were further validated using data from different GWAS sources to assess robustness.Results Genetically predicted high-er circulating glutamine levels were significantly associated with a lower risk of MG[OR(95％CI)=0.696(0.524,0.926),P=0.012 7,IVW model].Validation analyses using GWAS data from various sources also demonstrated a significant negative associa-tion between genetically predicted higher circulating glutamine levels and MG risk[OR(95％CI)=0.321(0.178,0.581),P=1.67x10-1,IVW model].Moreover,genetically predicted higher MG risk was associated with lower levels of circulating glutamine and alanine(β=-0.178±0.009,P=0.049;β=-0.013±0.007,P=0.048,IVW model,respectively).Conclusion Genetic evidence reveals a potential bidirectional causal relationship between circulating amino acid levels and MG risk.Further studies are required to elucidate the mechanisms underlying this relationship.

Objective:To analyze the clinical and genetic features of a child with Primary ciliary dyskinesia (PCD) due to compound heterozygous variants of the CCDC39 gene and a 22q11.21 deletion, and to explore the potential role of the two types of variants in the formation of complex phenotypes. Methods:A child presented at the Shanxi Children′s Hospital in March 2025. due to multiple congenital anomalies was selected as the study subject. Peripheral blood samples were taken from the child and her parents and subjected to whole-exome sequencing (WES). Candidate variants were verified by Sanger sequencing. Effect of splicing variant was predicted using SpliceAI, and pathogenicity was assessed based on the ACMG guidelines. Copy number variation (CNV) analysis was also performed. This study has been approved by the Medical Ethics Committee of the Hospital (Ethics No.: IRB-WZ-2025-019).Results:The patient has exhibited multiple features including severe pneumonia, bronchiectasis, localized pulmonary emphysema, scoliosis, tetralogy of Fallot, and atrial septal defect. Genetic testing revealed that she has harbored compound heterozygous variants of the CCDC39 gene, namely c. 1167+ 1G>A and c. 1009A>T, which were inherited from her father and mother, respectively, with the latter being a novel likely pathogenic variant. In addition, a heterozygous deletion of approximately 708 kb at 22q11.21 was detected. Conclusion:The coexistence of CCDC39 gene variants and a 22q11.21 deletion may underlay the development of complex clinical phenotypes in this child.