This paper introduces a real-world cohort research model for community-acquired pneumonia （CAP） based on the Jiangsu Traditional Chinese Medicine （TCM） Dominant Diseases Diagnosis and Treatment Data Platform. Firstly， data cleaning is performed by standardizing diagnosis， symptoms， treatment and imaging， intelligently extracting unstructured information， and cleaning and constructing a standardized database. Secondly， for cohort establishment， CAP patients across the province are screened in accordance with CAP diagnostic criteria to build a high-quality disease-specific cohort. Lastly， in terms of protocol design， the characteristics of TCM research and the CAP disease profile are considered to determine appropriate inclusion and exclusion criteria， estimate sample size， define interventions， outcomes and economic evaluations， providing a reference for real-world TCM research on CAP.

This paper introduces a real-world cohort research model for community-acquired pneumonia （CAP） based on the Jiangsu Traditional Chinese Medicine （TCM） Dominant Diseases Diagnosis and Treatment Data Platform. Firstly， data cleaning is performed by standardizing diagnosis， symptoms， treatment and imaging， intelligently extracting unstructured information， and cleaning and constructing a standardized database. Secondly， for cohort establishment， CAP patients across the province are screened in accordance with CAP diagnostic criteria to build a high-quality disease-specific cohort. Lastly， in terms of protocol design， the characteristics of TCM research and the CAP disease profile are considered to determine appropriate inclusion and exclusion criteria， estimate sample size， define interventions， outcomes and economic evaluations， providing a reference for real-world TCM research on CAP.

Inteins are unique protein insertion sequences capable of self-excision, enabling the covalent ligation of flanking extein peptides via amide bond formation. This process proceeds spontaneously without requiring external enzymes, cofactors, or chemical reagents, granting inteins exceptional biocompatibility and traceless performance in protein engineering applications. Split inteins represent a specialized and versatile subclass whose splicing domains are encoded by two separate gene fragments rather than a single continuous open reading frame. These fragments, known as the N-terminal (IntN) and C-terminal (IntC) split inteins, associate through non-covalent interactions including hydrophobic forces, hydrogen bonds, and van der Waals forces to assemble into an active three-dimensional structure, which then drives efficient extein ligation and enables protein trans-splicing. Protein trans-splicing mediated by split inteins has become a cornerstone for traceless protein ligation owing to its high specificity and irreversibility, fundamentally reshaping strategies for protein modification, assembly, and functional regulation. Compared with traditional chemical ligation methods, split intein systems require no complex chemical derivatization of peptide fragments and can operate efficiently at micromolar concentrations under physiological conditions, thus avoiding structural and functional damage caused by organic reagents. In contrast to enzymatic ligation tools such as sortase, split inteins eliminate the need for additional enzymes or cofactors, simplifying reaction systems, reducing costs, and minimizing non-specific side products. These distinctive advantages render split inteins highly promising for applications in chemical biology, synthetic biology, and biopharmaceutical development. In recent years, deepened mechanistic understanding has established structure-guided rational design as the primary approach to overcoming key limitations of split inteins, including intrinsic aggregation propensity, strict extein sequence dependence, and limited splicing efficiency. Bioinformatic tools have been used to identify aggregation-prone regions in the IntN fragment, and site-directed mutagenesis of hydrophobic residues, relocation of split sites, or removal of misfolding-prone sequences has substantially reduced in vitro aggregation and improved soluble expression and assembly activity. Rational engineering of catalytic residues and adjacent flexible loops has relaxed strict amino acid preferences at extein junctions, enhancing sequence tolerance and reducing the risk of functional impairment in target proteins. Consensus design based on multiple sequence alignments has yielded ultra-fast splicing variants such as Cfa DnaE and Cat-TerL, which exhibit significantly accelerated kinetics and improved tolerance to denaturing conditions. Meanwhile, advances in structural biology have further clarified the conformational dynamics and catalytic mechanisms of splicing, supporting the precise design of high-performance intein modules. On this basis, electrostatic interaction tuning and metagenomic screening have yielded multiple mutually orthogonal split intein pairs, enabling selective multi-fragment protein ligation and providing new routes for the efficient synthesis of large multi-domain functional proteins. With these engineered split inteins offering continuously improved performance and expanded applicability, protein trans-splicing has been widely applied in numerous cutting-edge areas of protein research and biomedicine. In gene delivery, split intein-based systems overcome the packaging limit of adeno-associated viral vectors, enabling the accurate reconstitution of large therapeutic proteins and base editors in target cells, thereby enhancing the efficacy and scope of gene therapy for genetic diseases. In internal protein sequence editing, split inteins mediate precise sequence replacement and modification in flexible regions or loops of target proteins, without the need for complex multi-step ligation and protein refolding involved in traditional protein semisynthesis. In protein-protein interaction studies, intein-mediated splicing covalently captures transient and weak intracellular complexes, enabling sensitive, high-throughput interaction detection and drug screening. In synthetic biology, conditionally controllable splicing systems support the construction of diverse intracellular and cell-surface biological logic gates for the precise regulation of cellular behavior. In mechanistic biochemical research, split inteins enable photocatalytic proximity labeling and site-specific tagging, allowing the preparation of homogeneous protein samples carrying precise post-translational modifications such as ubiquitination and polyglutamylation for chromatin interactome analysis and epigenetic studies. Moreover, covalent trapping strategies using split inteins stabilize transient enzymatic intermediates, providing unprecedented insights into molecular mechanisms such as nucleosome ubiquitination that are difficult to elucidate using conventional methods. This review systematically summarizes key technological advances in split inteins over the past decade, highlighting engineering strategies, mechanistic insights, and the development of orthogonal components. It comprehensively surveys emerging applications at the frontiers of protein research, analyzes current core challenges, and proposes future directions, particularly emphasizing artificial intelligence-driven de novo design and novel splicing pathways to break existing technical bottlenecks. By enabling traceless, efficient, and versatile protein manipulation, split inteins continue to serve as indispensable tools that drive innovation in protein engineering and fundamental life science research.

ObjectiveTo explore the effects of Kaixuan Jiedu core prescription （KXJD） on sphingolipid metabolism in the mouse model of imiquimod-induced psoriasis-like skin lesions. MethodsThirty-seven male C57BL/6J mice were randomly assigned into five groups： healthy control （n=11）， model （n=11）， methotrexate （MTX， n=5）， low-dose （15.21 g·kg^-1） KXJD （n=5）， and high-dose （30.42 g·kg^-1） KXJD （n=5）. Psoriasis-like skin lesions were induced in mice with 62.5 mg 5% imiquimod cream applied on the back. The KXJD groups and MTX group were treated with 0.2 mL corresponding decoction and MTX， respectively， by gavage daily， while the other groups were given an equal volume of normal saline by the same way. After 5 days of treatment， back skin lesions were collected. Firstly， healthy control and model mice were selected for tandem mass tag （TMT） quantitative proteomics （control vs model=3 vs 3） and targeted lipid metabolomics （control vs model=11 vs 11）. Then， the binding degree between core components and target proteins was predicted via network pharmacology and molecular docking. Finally， an animal experiment was performed to decipher the specific regulation mechanism of KXJD on sphingolipid metabolism. Immunohistochemistry was employed to determine the expression level of sphingosine-1-phosphate （S1P）， and Western blot was employed to determine the expression levels of sphingosine kinase 2 （SPHK2） and monocyte chemotactic protein-1 （MCP-1）. ResultsTMT proteomics and targeted lipid metabolomics suggested that sphingolipid metabolism was active in the psoriatic skin， and key proteases ［serine palmitoyltransferase， long chain base subunit 2 （SPTLC2）， SPHK2， delta（4）-desaturase sphingolipid 1 （Degs1）， and ceramide synthase 4 （CerS4）］ and 8 sphingolipid metabolites （including ceramides， sphingol， sphingomyelin， and glycosphingolipid） expressed abnormally （P<0.05） compared with those in the healthy skin. The molecular docking results indicated that the binding energy between the active components （quercetin， kaempferol， and luteolin） in KXJD and key proteins involved in sphingolipid metabolism was less than-8 kal·mol^-1. Further experimental verification showed elevated expression levels of SPHK2， S1P， and MCP-1 in psoriatic skin compared with healthy skin （P<0.05）， and KXJD down-regulated the expression levels of SPHK2， S1P， and MCP-1 compared with the model group （P<0.05）. ConclusionThis study indicates that there is an imbalance in sphingolipid metabolism in psoriatic skin lesions. KXJD may reduce psoriasis-like lesions in mice by regulating sphingolipid metabolism via the SPHK2/S1P/MCP-1 pathway.

ObjectiveTo explore the effects of Kaixuan Jiedu core prescription （KXJD） on sphingolipid metabolism in the mouse model of imiquimod-induced psoriasis-like skin lesions. MethodsThirty-seven male C57BL/6J mice were randomly assigned into five groups： healthy control （n=11）， model （n=11）， methotrexate （MTX， n=5）， low-dose （15.21 g·kg^-1） KXJD （n=5）， and high-dose （30.42 g·kg^-1） KXJD （n=5）. Psoriasis-like skin lesions were induced in mice with 62.5 mg 5% imiquimod cream applied on the back. The KXJD groups and MTX group were treated with 0.2 mL corresponding decoction and MTX， respectively， by gavage daily， while the other groups were given an equal volume of normal saline by the same way. After 5 days of treatment， back skin lesions were collected. Firstly， healthy control and model mice were selected for tandem mass tag （TMT） quantitative proteomics （control vs model=3 vs 3） and targeted lipid metabolomics （control vs model=11 vs 11）. Then， the binding degree between core components and target proteins was predicted via network pharmacology and molecular docking. Finally， an animal experiment was performed to decipher the specific regulation mechanism of KXJD on sphingolipid metabolism. Immunohistochemistry was employed to determine the expression level of sphingosine-1-phosphate （S1P）， and Western blot was employed to determine the expression levels of sphingosine kinase 2 （SPHK2） and monocyte chemotactic protein-1 （MCP-1）. ResultsTMT proteomics and targeted lipid metabolomics suggested that sphingolipid metabolism was active in the psoriatic skin， and key proteases ［serine palmitoyltransferase， long chain base subunit 2 （SPTLC2）， SPHK2， delta（4）-desaturase sphingolipid 1 （Degs1）， and ceramide synthase 4 （CerS4）］ and 8 sphingolipid metabolites （including ceramides， sphingol， sphingomyelin， and glycosphingolipid） expressed abnormally （P<0.05） compared with those in the healthy skin. The molecular docking results indicated that the binding energy between the active components （quercetin， kaempferol， and luteolin） in KXJD and key proteins involved in sphingolipid metabolism was less than-8 kal·mol^-1. Further experimental verification showed elevated expression levels of SPHK2， S1P， and MCP-1 in psoriatic skin compared with healthy skin （P<0.05）， and KXJD down-regulated the expression levels of SPHK2， S1P， and MCP-1 compared with the model group （P<0.05）. ConclusionThis study indicates that there is an imbalance in sphingolipid metabolism in psoriatic skin lesions. KXJD may reduce psoriasis-like lesions in mice by regulating sphingolipid metabolism via the SPHK2/S1P/MCP-1 pathway.

Loss of protein homeostasis is a hallmark of cellular senescence, and ribosome pausing plays a crucial role in the collapse of proteostasis. However, our understanding of ribosome pausing in senescent cells remains limited. In this study, we utilized ribosome profiling and G-quadruplex RNA immunoprecipitation sequencing techniques to explore the impact of RNA G-quadruplex (rG4) on the translation efficiency in senescent cells. Our results revealed a reduction in the translation efficiency of rG4-rich genes in senescent cells and demonstrated that rG4 structures within coding sequence can impede translation both in vivo and in vitro. Moreover, we observed a significant increase in the abundance of rG4 structures in senescent cells, and the stabilization of the rG4 structures further exacerbated cellular senescence. Mechanistically, the RNA helicase DHX9 functions as a key regulator of rG4 abundance, and its reduced expression in senescent cells contributing to increased ribosome pausing. Additionally, we also observed an increased abundance of rG4, an imbalance in protein homeostasis, and reduced DHX9 expression in aged mice. In summary, our findings reveal a novel biological role for rG4 and DHX9 in the regulation of translation and proteostasis, which may have implications for delaying cellular senescence and the aging process.
G-Quadruplexes ; Cellular Senescence ; Ribosomes/genetics* ; Humans ; Animals ; Mice ; DEAD-box RNA Helicases/genetics* ; Protein Biosynthesis ; RNA/chemistry* ; Neoplasm Proteins

Objective:To investigate the effects of blocking MAPK signaling pathway on biological characteristics of residual cancer cells after radiofrequency ablation of hepatocellular carcinoma (HCC).Methods:HepG2 cell line was selected and residual liver cancer cells (HepG2-H cells) after radiofrequency ablation were prepared by stimulating radiofrequency ablation in vitro. The morphology of the 2 cells was observed after 48 h culture. The gene expression difference of HepG2 and HepG2-H cells was detected by using RNA sequencing, and the differential genes were analyzed by using Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis. HepG2-H cells were treated with different concentrations (10, 20, 30 μmol /L) of MAPK signaling pathway specific blocker U0126, and cells without adding U0126 were treated as the control group. The proliferative ability of the cells in each group was detected by using methyl thiazolyl tetrazolium (MTT) method. The migration ability of cells in each group was detected by using cell scratch test. The invasion ability of cells in each group was detected by using cell invasion assay.Results:After 48 h culture of HepG2-H cells and HepG2 cells, adherent cells with epithelioid growth were closely arranged at the bottom of the petri dish. The confluence of HepG2-H cells reached about 80%, and the confluence of HepG2 cells reached about 70%. A total of 16 255 genes were determined in RNA sequencing. Compared with HepG2 cells, 85 up-regulated genes and 312 down-regulated genes were detected in HepG2-H cells. KEGG pathway enrichment analysis showed that MAPK signaling pathway was most significantly affected by differential genes. The absorbance values of the control group and HepG2-H cells treated with 10, 20 and 30 μmol /L U0126 for 72 h were 1.12±0.08, 0.69±0.08, 0.51±0.06 and 0.45±0.08, respectively, and the difference was statistically significant ( F = 5.12, P = 0.013). The migration areas of HepG2-H cells for 24 h were (6 054±269) μm 2, (5 640±285) μm 2, (5 082±238) μm 2, (4 822±246) μm 2, respectively, and the difference was statistically significant ( F = 3.37, P = 0.043). The number of invasive cells for 24 h was 227±17, 164±19, 138±18, 129±19, respectively, and the difference was statistically significant ( F = 4.04, P = 0.032). Conclusions:Blocking MAPK signaling pathway can inhibit the proliferation, migration and invasion ability of residual cancer cells after radiofrequency ablation of HCC.

Three evaluation methods were recommended for the key properties of the intravascular catheter lubricating coating such as stability,lubricity and integrity,including insoluble particle test method,friction test procedure and appearance detection method.Fifteen batches of microcatheters produced by different manufacturers were selected for testing to clarify the three methods in test principle,step,result,characteristic.References were provided for the design,production,evaluation and regulation of intravascular catheters with lubricant coatings.[Chinese Medical Equipment Journal,2025,46(1):66-72]

Objective To summarize the changing prevalence of carbapenem resistance in Enterobacterales based on the data of CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021 for improving antimicrobial treatment in clinical practice.Methods Antimicrobial susceptibility testing was performed using a commercial automated susceptibility testing system according to the unified CHINET protocol.The results were interpreted according to the breakpoints of the Clinical & Laboratory Standards Institute(CLSI)M100 31st ed in 2021.Results Over the seven-year period(2015-2021),the overall prevalence of carbapenem-resistant Enterobacterales(CRE)was 9.43％(62 342/661 235).The prevalence of CRE strains in Klebsiella pneumoniae,Citrobacter freundii,and Enterobacter cloacae was 22.38％,9.73％,and 8.47％,respectively.The prevalence of CRE strains in Escherichia coli was 1.99％.A few CRE strains were also identified in Salmonella and Shigella.The CRE strains were mainly isolated from respiratory specimens(44.23±2.80)％,followed by blood(20.88±3.40)％and urine(18.40±3.45)％.Intensive care units(ICUs)were the major source of the CRE strains(27.43±5.20)％.CRE strains were resistant to all the β-lactam antibiotics tested and most non-β-lactam antimicrobial agents.The CRE strains were relatively susceptible to tigecycline and polymyxins with low resistance rates.Conclusions The prevalence of CRE strains was increasing from 2015 to 2021.CRE strains were highly resistant to most of the antibacterial drugs used in clinical practice.Clinicians should prescribe antimicrobial agents rationally.Hospitals should strengthen antibiotic stewardship in key clinical settings such as ICUs,and take effective infection control measures to curb CRE outbreak and epidemic in hospitals.

Objective To characterize the changing species distribution and antibiotic resistance profiles of respiratory isolates in hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Methods Commercial automated antimicrobial susceptibility testing systems and disk diffusion method were used to test the susceptibility of respiratory bacterial isolates to antimicrobial agents following the standardized technical protocol established by the CHINET program.Results A total of 589 746 respiratory isolates were collected from 2015 to 2021.Overall,82.6％of the isolates were Gram-negative bacteria and 17.4％were Gram-positive bacteria.The bacterial isolates from outpatients and inpatients accounted for(6.0±0.9)％and(94.0±0.1)％,respectively.The top microorganisms were Klebsiella spp.,Acinetobacter spp.,Pseudomonas aeruginosa,Staphylococcus aureus,Haemophilus spp.,Stenotrophomonas maltophilia,Escherichia coli,and Streptococcus pneumoniae.Each microorganism was isolated from significantly more males than from females(P＜0.05).The overall prevalence of methicillin-resistant S.aureus(MRSA)was 39.9％.The prevalence of penicillin-resistant S.pneumoniae was 1.4％.The prevalence of extended-spectrum β-lactamase(ESBL)-producing E.coli and K.pneumoniae was 67.8％and 41.3％,respectively.The overall prevalence of carbapenem-resistant E.coli,K.pneumoniae,Enterobacter cloacae,Pseudomonas aeruginosa,and Acinetobacter baumannii was 3.7％,20.8％,9.4％,29.8％,and 73.3％,respectively.The prevalence of β-lactamase was 96.1％in Moraxella catarrhalis and 60.0％in Haemophilus influenzae.The H.influenzae isolates from children(＜18 years)showed significantly higher resistance rates to β-lactam antibiotics than the isolates from adults(P＜0.05).Conclusions Gram-negative bacteria are still predominant in respiratory isolates associated with serious antibiotic resistance.Antimicrobial resistance surveillance should be strengthened in clinical practice to support accurate etiological diagnosis and appropriate antimicrobial therapy based on antimicrobial susceptibility testing results.