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.

ObjectiveThis study aimed to elucidate the mechanistic role of Staphylococcus aureus in the pathogenesis of atopic dermatitis (AD), a chronic inflammatory skin disorder characterized by pruritus and barrier dysfunction. A key focus was screening traditional Chinese medicine (TCM) active components with dual antibacterial and antipruritic efficacy, followed by systematic evaluation of their in vitro antibacterial activity. Additionally, a novel drug delivery system was constructed to enable localized efficient drug delivery, inhibiting S. aureus proliferation and alleviating its induced pruritus, thereby providing new strategies for targeted AD therapy. MethodsMale C57BL/6J mice aged 6-8 weeks (body weight 18-22 g) were used to establish an AD model via repeated oxazolone sensitization. On day 14, microbial samples were collected from the lesional area (1 cm²) using sterile cotton swabs, followed by vortex mixing, serial dilution, and plating on 5% sheep blood agar plates (incubated at 37°C for 24 h). Single colonies with complete transparent β-hemolytic zones were isolated and identified as vancomycin-intermediate S. aureus (VISA) via 16S rRNA sequencing. An S. aureus mono-infection animal model was then established by applying gauze saturated with bacterial suspension (McFarland turbidity 0.1) to the nape and back skin of mice. The pruritic phenotype and inflammatory cell infiltration induced by S. aureus were evaluated using comprehensive approaches including behavioral assays (e.g., scratching frequency recording), hematoxylin-eosin (HE) staining, and toluidine blue staining. The in vitro antibacterial efficacy of the TCM monomer pseudolaric acid B (PAB) and double network hydrogel (DN) was separately assessed by disk diffusion assay, while the minimum inhibitory concentration (MIC) of PAB was determined via broth dilution method. Further validation of the pharmacodynamic characteristics of the composite system (PAB@DN, composed of PAB and DN) was conducted through behavioral assays, HE staining, and dermatitis scoring, with its drug release profile evaluated by mass spectrometry analysis. Based on scratching behavioral analysis and dermatitis scoring, the optimal ratio and concentration of PAB@DN were optimized. ResultsThe S. aureus load in AD lesional tissues was significantly higher than in normal skin ((5.3±0.33)×10⁶ CFU vs. (3.6±0.26)×10⁷ CFU, P<0.001). In the S. aureus mono-infection group, mice exhibited a 6.7-fold increase in scratching frequency compared to the control group. HE staining revealed marked epidermal thickening ((10.4±2.39) μm vs. (85.6±1.95) μm, P<0.000 1), and toluidine blue staining showed a 23-fold increase in mast cell degranulation. Pseudolaric acid B exhibited a significant concentration-dependent inhibitory effect onS. aureus growth, with its in vitro antibacterial effect being 57% that of the antibiotic cefepime (inhibition zone diameter: PAB (1.885±0.036) cm vs. cefepime (3.636±0.005) cm, P<0.000 1) and a minimum inhibitory concentration (MIC) of 1 g/L. The carrier double network hydrogel (DN) itself lacked direct antibacterial activity (no significant difference in inhibition zone diameter compared to the control) but effectively ameliorated the dry symptoms of AD-like lesions. The PAB@DN composite system demonstrated a synergistic effect compared to individual components, resulting in a 50% reduction in scratching behavior, an 86% decrease in dermatitis score, and a 60% reduction in epidermal thickening. It also reduced the S. aureus load in mouse skin by approximately 34%, with the optimal effective formulation being PAB at 1 g/L loaded onto DN. ConclusionS. aureus colonization plays a critical driving role in the onset and progression of AD. Using an S. aureus infection model, this study confirmed that the pseudolaric acidB-hydrogel composite delivery system (PAB@DN) can effectively alleviate S. aureus-induced pruritus and skin damage, providing experimental evidence for microbiota-targeted therapy of AD.

Objective This study reports on the obligatory parasitism of water mites Arrenurus sp. on Anopheles messeae at the Manzhouli Port, Inner Mongolia, China. Methods Duing July 2024, a survey on the mosquito diversity was conducted at the Manzhouli Port. Captured mosquitoes and their ectoparasites were identified to species level. Results A total of 1840 adult mosquitoes were collected, representing species from three genera: Culex(Cx. modestus, Cx. pipiens pallens), Aedes(Ae. dorsalis, Ae. flavidorsalis, Ae. flavescens), and Anopheles (An. messeae). Among all the mosqutioes specimens,3 out of 150 captured An. messeae were found to carry ectoparasitic mites, with number of 2,4,27 mites separately. Morphological and molecular identification reached the same result as water mites(Hydrachnidiae, Hydracrina). COI gene sequence showed 94% similarity with the closest species Arrenurus truncatellus. Conlusions Literature review suggests water mites are host-specific parasitism of mosquito species and herein with the first record of Arrenurus sp. parasiting on An. Messeae in the most high-latitude region globally.

Objective To explore the facilitators and barriers of palliative care volunteering,and to provide references for further advancement of palliative care volunteering.Methods Purposeful sampling was used to select 12 volunteers from a palliative care ward in Hangzhou,Zhejiang Province,between April and September 2024.Semi-structured interviews were conducted,and directed content analysis was applied to organize and analyze the data,followed by theme analysis.Results Facilitators and barriers for volunteers' participation in palliative care volunteering were extracted.The 5 sub-themes of facilitators include motivating factors and perceived benefits,support and collaboration among volunteers,professional training and healthcare recognition,increased social awareness and public acceptance,and government support and institutional safeguards.The 5 sub-themes of barriers include limitations in individual capacity,challenges in collaboration with patients,families and healthcare workers,inadequate management and service mechanisms,uneven development of palliative care and insufficient public attention to psychological problems,and inadequate relevant laws and incentives.Conclusion There are more factors affecting the development of palliative care volunteering,and healthcare professionals should adopt targeted strategies to promote the active participation of volunteers in order to promote the sustainable development of palliative care volunteering.

Due to the poor ionization efficiency and the weak mass spectrometry(MS)intensity of weakly polar substances,direct analysis using the traditional electrospray ionization mass spectrometry(ESI-MS)is a big challenge.In this study,a novel rapid on-site detection method of four prohibited sex hormones in cosmetics was proposed using online derivatization strategy coupled with a miniature mass spectrometer.The target substances in the samples were extracted by a custom-made polyaniline/multi-walled carbon nanotube solid-phase microextraction(SPME)probe.The stirring speed was 200 r/min,the extraction temperature was 40℃,and the extraction time was 2 min.A pulled dual-channel θ borosilicate glass capillary emitter was used as the nano-ESI ion source.The SPME probe was inserted into the channel containing methanol in theθborosilicate glass capillary.When the spray voltage was applied,the four sex hormones were desorbed and formed spray microdroplets,which then collided with the hydroxylamine microdroplets generated from the other channel.The microdroplets of reaction product entered into the miniature mass spectrometer for direct analysis.The limits of detection(LOD)and limits of quantification(LOQ)for the four sex hormones were 10-20 ng/mL and 20-50 ng/mL,respectively.The recoveries were from 84.6%to 107.8%with the relative standard deviations(RSD)from 4.1%to 11.6%.Compared to detection without derivatization,the MS signals of the four target substances were increased by 3 to 15 times.This method was simple,rapid,highly efficient and sensitive,and suitable for on-site rapid analysis of weakly polar sex hormones in cosmetics.

Functional dyspepsia (FD), characterized by persistent or recurrent dyspeptic symptoms without identifiable organic, systemic or metabolic causes, is an increasingly recognized global health issue. The objective of this guideline is to equip clinicians and nursing professionals with evidence-based strategies for the management and treatment of adult patients with FD using traditional Chinese medicine (TCM). The Guideline Development Group consulted existing TCM consensus documents on FD and convened a panel of 35 clinicians to generate initial clinical queries. To address these queries, a systematic literature search was conducted across PubMed, EMBASE, the Cochrane Library, China National Knowledge Infrastructure (CNKI), VIP Database, China Biology Medicine (SinoMed) Database, Wanfang Database, Traditional Medicine Research Data Expanded (TMRDE), and the Traditional Chinese Medical Literature Analysis and Retrieval System (TCMLARS). The evidence from the literature was critically appraised using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. The strength of the recommendations was ascertained through a consensus-building process involving TCM and allopathic medicine experts, methodologists, pharmacologists, nursing specialists, and health economists, leveraging their collective expertise and empirical knowledge. The guideline comprises a total of 43 evidence-informed recommendations that span a range of clinical aspects, including the pathogenesis according to TCM, diagnostic approaches, therapeutic interventions, efficacy assessments, and prognostic considerations. Please cite this article as: Zhang SS, Zhao LQ, Hou XH, Bian ZX, Zheng JH, Tian HH, Yang GH, Hong WS, He YY, Liu L, Shen H, Li YP, Xie S, Shu J, Zeng BF, Li JX, Liu Z, Xiao ZH, Xiao JD, Zheng PY, Huang SG, Chen SL, Fei GJ. International clinical practice guideline on the use of traditional Chinese medicine for functional dyspepsia (2025). J Integr Med. 2025; 23(5):502-518.
Dyspepsia/drug therapy* ; Humans ; Medicine, Chinese Traditional/methods* ; Practice Guidelines as Topic ; Drugs, Chinese Herbal/therapeutic use*

OBJECTIVE: Huachansu injection (HCSI), a promising anti-cancer Chinese medicine injection, has been reported to have the potential for reducing the toxicity of chemotherapy and improving the quality of life for colorectal cancer (CRC) patients. The objective of this study is to explore the synergistic and detoxifying effects of HCSI when used in combination with irinotecan (CPT-11). METHODS: To investigate the effect of HCSI on anti-CRC efficacy and intestinal toxicity of CPT-11, we measured changes in the biological behavior of LoVo cells in vitro, and anti-tumor effects in LoVo cell xenograft nude mice models in vivo. Meanwhile, the effect of HCSI on intestinal toxicity and the uridine diphosphate-glucuronosyltransferase 1A1 (UGT1A1) expression was investigated in the CPT-11-induced colitis mouse model. Subsequently, we measured the effect of HCSI and its 13 constituent bufadienolides on the expression of UGT1A1 and organic anion transporting polypeptides 1B3 (OATP1B3) in HepG2 cells. RESULTS: The combination index (CI) results showed that the combination of HCSI and CPT-11 exhibited a synergistic effect (CI < 1), which significantly suppressing the LoVo cell migration, enhancing G2/M and S phase arrest, and inhibiting tumor growth in vivo. Additionally, the damage to intestinal tissues was attenuated by HCSI in CPT-11-induced colitis model, while the increased expression of UGT1A1 in HepG2 cells and in mouse was observed. CONCLUSION The co-therapy with HCSI alleviated the intestinal toxicity induced by CPT-11 and exerted an enhanced anti-CRC effect. The detoxifying mechanism may be related to the increased expression of UGT1A1 and OATP1B3 by HCSI and its bufadienolides components. The findings of this study may serve as a theoretical insights and strategies to improve CRC patient outcomes. Please cite this article as: Jiang B, Meng ZY, Hu YJ, Chen JJ, Zong L, Xu LY, Zhang XQ, Zhang JX, Han YL. Huachansu injection enhances anti-colorectal cancer efficacy of irinotecan and alleviates its induced intestinal toxicity through upregulating UGT1A1-OATP1B3 expression in vitro and in vivo. J Integr Med. 2025; 23(5):576-590.
Irinotecan/therapeutic use* ; Animals ; Glucuronosyltransferase/genetics* ; Humans ; Colorectal Neoplasms/metabolism* ; Drugs, Chinese Herbal/therapeutic use* ; Mice, Nude ; Mice ; Up-Regulation/drug effects* ; Male ; Xenograft Model Antitumor Assays ; Mice, Inbred BALB C ; Hep G2 Cells ; Cell Line, Tumor ; Intestines/drug effects* ; Amphibian Venoms

OBJECTIVE: The results of limited studies on the relationship between environmental pollution and dementia have been contradictory. We analyzed the combined effects of PM _2.5 and smoking on the prevalence of dementia and cognitive impairment in an elderly community-dwelling Chinese population. METHODS: We assessed 24,117 individuals along with the annual average PM _2.5 concentrations from 2012 to 2016. Dementia was confirmed in the baseline survey at a qualified clinical facility, and newly suspected dementia was assessed in 2017, after excluding cases of suspected dementia in 2015. National census data were used to weight the sample data to reflect the entire population in China, with multiple logistic regression performed to analyze the combined effects of PM _2.5 and smoking frequency on dementia and cognitive impairment. RESULTS: Individuals exposed to the highest PM _2.5 concentration and smoked daily were at higher risk of dementia than those in the lowest PM _2.5 concentration group ( OR, 1.603; 95% CI [1.626-1.635], P < 0.0001) and in the nonsmoking group ( OR, 1.248; 95% CI [1.244-1.252]; P < 0.0001). Moderate PM _2.5 exposure and occasional smoking together increased the short-term risk of cognitive impairment. High-level PM _2.5 exposure and smoking were associated with an increased risk of dementia, so more efforts are needed to reduce this risk through environmental protection and antismoking campaigns. CONCLUSION High-level PM _2.5 exposure and smoking were associated with an increased risk of dementia. Lowering the ambient PM _2.5, and smoking cessation are recommended to promote health.
Humans ; Dementia/etiology* ; Male ; Aged ; Female ; Cognitive Dysfunction/etiology* ; China/epidemiology* ; Particulate Matter/analysis* ; Smoking/epidemiology* ; Air Pollutants/analysis* ; Aged, 80 and over ; Environmental Exposure/adverse effects* ; Prevalence ; Middle Aged

OBJECTIVE: Cigarette smoking exacerbates the progression of pulmonary tuberculosis (TB). The role of tertiary lymphoid structures (TLS) in chronic lung diseases has gained attention; however, it remains unclear whether smoking-exacerbated lung damage in TB is associated with TLS. This study aimed to analyze the characteristics of pulmonary TLS in smokers with TB and to explore the possible role of TLS in smoking-related lung injury in TB. METHODS: Lung tissues from 36 male patients (18 smokers and 18 non-smokers) who underwent surgical resection for pulmonary TB were included in this study. Pathological and immunohistological analyses were conducted to evaluate the quantity of TLS, and chest computed tomography (CT) was used to assess the severity of lung lesions. The correlation between the TLS quantity and TB lesion severity scores was analyzed. The immune cells and chemokines involved in TLS formation were also evaluated and compared between smokers and non-smokers. RESULTS: Smoker patients with TB had significantly higher TLS than non-smokers ( P < 0.001). The TLS quantity in both the lung parenchyma and peribronchial regions correlated with TB lesion severity on chest CT (parenchyma: r = 0.5767; peribronchial: r = 0.7373; both P < 0.001). Immunohistochemical analysis showed increased B cells, T cells, and C-X-C motif chemokine ligand 13 (CXCL13) expression in smoker patients with TB ( P < 0.001). CONCLUSION Smoker TB patients exhibited increased pulmonary TLS, which was associated with exacerbated lung lesions on chest CT, suggesting that cigarette smoking may exacerbate lung damage by promoting TLS formation.
Humans ; Male ; Tuberculosis, Pulmonary/immunology* ; Middle Aged ; Tertiary Lymphoid Structures/pathology* ; Adult ; Lung/pathology* ; Smoking/adverse effects* ; Smokers ; Aged ; Tomography, X-Ray Computed

Objective To explore the facilitators and barriers of palliative care volunteering,and to provide references for further advancement of palliative care volunteering.Methods Purposeful sampling was used to select 12 volunteers from a palliative care ward in Hangzhou,Zhejiang Province,between April and September 2024.Semi-structured interviews were conducted,and directed content analysis was applied to organize and analyze the data,followed by theme analysis.Results Facilitators and barriers for volunteers' participation in palliative care volunteering were extracted.The 5 sub-themes of facilitators include motivating factors and perceived benefits,support and collaboration among volunteers,professional training and healthcare recognition,increased social awareness and public acceptance,and government support and institutional safeguards.The 5 sub-themes of barriers include limitations in individual capacity,challenges in collaboration with patients,families and healthcare workers,inadequate management and service mechanisms,uneven development of palliative care and insufficient public attention to psychological problems,and inadequate relevant laws and incentives.Conclusion There are more factors affecting the development of palliative care volunteering,and healthcare professionals should adopt targeted strategies to promote the active participation of volunteers in order to promote the sustainable development of palliative care volunteering.