Objective: To investigate whether membrane vesicles (MVs) of Streptococcus mutans （S.mutans） contain autoinducer-2 (AI-2) and to preliminarily explore the effects of these MVs on the growth and biofilm formation of S. mutans. Methods: MVs were isolated from the S. mutans UA159 strain using differential centrifugation. The isolated MVs were characterized by nanoparticle tracking analysis for particle size and concentration and observed by transmission electron microscopy. The presence of AI-2 was identified using the Vibrio harveyi BB170 bioluminescence assay: the BB170 diluent was supplemented with AB medium (control group), MV extract (MVs group), pre-ultrafiltration supernatant (Sup group), or post-ultrafiltration supernatant (Sup-af group). The effects of MVs on growth and biofilm formation were assessed using the S.mutans UA159 strain or a luxS deletion mutant as the control group, compared with experimental groups stimulated with gradient concentrations of MVs (MVs-2.0E+7, MVs-2.0E+8, and MVs-2.0E+9 groups). Growth curves, MTT assay, and colony-forming unit (CFU) counts were used to determine changes in growth capacity. Biofilm formation was evaluated using crystal violet staining, confocal laser scanning microscopy, and the anthrone method for polysaccharide quantification. Results: Enriched S. mutans MVs were successfully obtained, with an average particle size of approximately 94.19 nm and a concentration of 1.87E+11 particles/mL. The bioluminescence assay showed that the luminescence intensity of the Sup group was higher than that of the Sup-af group, and the MVs group exhibited higher intensity than the control group. Assessments via growth curves, MTT assay, and CFU counts indicated no significant differences in the growth capacity of the various S. mutans strains after treatment with different concentrations of MVs. Crystal violet staining quantification and confocal laser scanning microscopy observations revealed that high-concentration MV treatment (2.0E+9 particles/mL group) resulted in lower biofilm mass compared to the control. The anthrone method showed that the production of both water-soluble and water-insoluble polysaccharides was significantly lower in the high-concentration MV group than in the control. Conclusion S. mutans MVs contain the quorum sensing signal molecule AI-2. These MVs do not significantly affect the growth of S. mutans, but they can regulate biofilm formation and exhibit an inhibitory effect at high concentrations.

Objective To analyze the distribution characteristics and trends of occupational exposure types of medical radiation workers in Gansu Province, China, and to provide a basis for administrative departments to formulate and adjust radiation protection policies. Methods According to the radiation health information platform, the data of occupational exposure types of radiation workers in Gansu Province from 2014 to 2023 were obtained. The proportions of occupational exposure types in each physical examination year was statistically analyzed. Results From 2014 to 2023, the number of medical radiation workers accounted for more than 70% of the total number of radiation workers. The proportion of X-ray imaging diagnostic radiation workers in the total number of medical radiation workers gradually decreased but remained the highest, exceeding 68% annually. The proportion of interventional radiology workers in the total number of medical radiation workers increased from 13.8% to 25.5%. The proportions of radiation therapy and nuclear medicine workers in the total number of medical radiation workers increased slowly. The numbers of interventional radiology and radiotherapy workers in tertiary hospitals both accounted for more than 70% of the total number of such workers in the province. The proportion of interventional radiology workers increased and then decreased. The proportion of radiotherapy workers increased significantly from 70.5% to 93.0%. The number of nuclear medicine workers in tertiary hospitals accounted for more than 80% of such workers in the province. Conclusion Radiation protection policies and measures should be adjusted according to the changes in the types of occupational exposure. The focus of these policies and measures should differ depending on the level of healthcare institutions, the type of radiological diagnostic and therapeutic services, and the characteristics of various occupational exposure types .

ObjectiveThe nucleolar protein PES1 (Pescadillo homolog 1) plays critical roles in ribosome biogenesis and cell cycle regulation, yet its involvement in cellular senescence remains poorly understood. This study aimed to comprehensively investigate the functional consequences of PES1 suppression in cellular senescence and elucidate the molecular mechanisms underlying its regulatory role. MethodsInitially, we assessed PES1 expression patterns in two distinct senescence models: replicative senescent mouse embryonic fibroblasts (MEFs) and doxorubicin-induced senescent human hepatocellular carcinoma HepG2 cells. Subsequently, PES1 expression was specifically downregulated using siRNA-mediated knockdown in these cell lines as well as additional relevant cell types. Cellular proliferation and senescence were assessed by EdU incorporation and SA-β-gal staining assays, respectively. The expression of senescence-associated proteins (p53, p21, and Rb) and SASP factors (IL-6, IL-1β, and IL-8) were analyzed by Western blot or qPCR. Furthermore, Northern blot and immunofluorescence were employed to evaluate pre-rRNA processing and nucleolar morphology. ResultsPES1 expression was significantly downregulated in senescent MEFs and HepG2 cells. PES1 knockdown resulted in decreased EdU-positive cells and increased SA‑β‑gal-positive cells, indicating proliferation inhibition and senescence induction. Mechanistically, PES1 suppression activated the p53-p21 pathway without affecting Rb expression, while upregulating IL-6, IL-1β, and IL-8 production. Notably, PES1 depletion impaired pre-rRNA maturation and induced nucleolar stress, as evidenced by aberrant nucleolar morphology. ConclusionOur findings demonstrate that PES1 deficiency triggers nucleolar stress and promotes p53-dependent (but Rb-independent) cellular senescence, highlighting its crucial role in maintaining nucleolar homeostasis and regulating senescence-associated pathways.

The disturbance of the human microbiota influences the occurrence and progression of many diseases. Live therapeutic bacteria, with their genetic manipulability, anaerobic tendencies, and immunomodulatory properties, are emerging as promising therapeutic agents. However, their clinical applications face challenges in maintaining activity and achieving precise spatiotemporal release, particularly in the harsh gastrointestinal environment. This review highlights the innovative bacterial functionalized encapsulation strategies developed through advances in physicochemical and biological techniques. We comprehensively review how bacterial encapsulation strategies can be used to provide physical barriers and enhanced adhesion properties to live microorganisms, while introducing superior material properties to live bacteria. In addition, this review outlines how bacterial surface coating can facilitate targeted delivery and precise spatiotemporal release of live bacteria. Furthermore, it elucidates their potential applications for treating different diseases, along with critical perspectives on challenges in clinical translation. This review comprehensively analyzes the connection between functionalized bacterial encapsulation and innovative biomedical applications, providing a theoretical reference for the development of next-generation bacterial therapies.

Ursodeoxycholic acid (UDCA) is a naturally occurring, low-toxicity, and hydrophilic bile acid (BA) in the human body that is converted by intestinal flora using primary BA. Solute carrier family 7 member 11 (SLC7A11) functions to uptake extracellular cystine in exchange for glutamate, and is highly expressed in a variety of human cancers. Retroperitoneal liposarcoma (RLPS) refers to liposarcoma originating from the retroperitoneal area. Lipidomics analysis revealed that UDCA was one of the most significantly downregulated metabolites in sera of RLPS patients compared with healthy subjects. The augmentation of UDCA concentration (≥25 μg/mL) demonstrated a suppressive effect on the proliferation of liposarcoma cells. [¹⁵N₂]-cystine and [¹³C₅]-glutamine isotope tracing revealed that UDCA impairs cystine uptake and glutathione (GSH) synthesis. Mechanistically, UDCA binds to the cystine transporter SLC7A11 to inhibit cystine uptake and impair GSH de novo synthesis, leading to reactive oxygen species (ROS) accumulation and mitochondrial oxidative damage. Furthermore, UDCA can promote the anti-cancer effects of ferroptosis inducers (Erastin, RSL3), the murine double minute 2 (MDM2) inhibitors (Nutlin 3a, RG7112), cyclin dependent kinase 4 (CDK4) inhibitor (Abemaciclib), and glutaminase inhibitor (CB839). Together, UDCA functions as a cystine exchange factor that binds to SLC7A11 for antitumor activity, and SLC7A11 is not only a new transporter for BA but also a clinically applicable target for UDCA. More importantly, in combination with other antitumor chemotherapy or physiotherapy treatments, UDCA may provide effective and promising treatment strategies for RLPS or other types of tumors in a ROS-dependent manner.

OBJECTIVE: To investigate the association of various polycyclic aromatic hydrocarbon (PAH) metabolites with diverse subtypes of cardiovascular disease (CVD) risk. METHODS: A novel predicting risk of cardiovascular disease EVENTs PREVENT equation was used to estimate the 10-year diverse subtypes of CVD risk, and their associations with PAH metabolites were analyzed using multiple logistic regression models, the weighted quantile sum (WQS) model, the quantile g-computation (qgcomp) model, and a stratified analysis of subgroups. RESULTS: For this study, six thousand seven hundred and forty-five participants were selected, and significant positive associations were observed between PAHs, naphthalene (NAP), and fluorene (FLU), and the risks of total CVD, atherosclerotic cardiovascular disease (ASCVD), and heart failure (HF). NAP and FLU were the primary contributors to the effects of PAH mixtures, and their associations with total CVD, ASCVD, and HF risk were significant in younger participants (30 ≤ age < 50 years); however, the associations of phenanthrene (PHEN) with ASCVD, HF, coronary heart disease (CHD), and stroke were dominant in aging participants (age ≥ 50 years). Notably, pyrene (PYR) was negatively associated with the risk of ASCVD, HF, CHD, and stroke. Similarly, negative associations of PYR with the four CVD subtypes were noticeable in aging participants. CONCLUSION Different PAHs metabolites had different impacts on each CVD subtype among different age groups. Notably, the protective effects of PYR on ASCVD, HF, CHD, and stroke were noticeable in aging individuals.
Humans ; Cardiovascular Diseases/chemically induced* ; Middle Aged ; Polycyclic Aromatic Hydrocarbons/metabolism* ; Male ; Female ; Adult ; Aged ; Risk Factors ; China/epidemiology*

Soil cadmium (Cd) pollution is one of the major environmental problems globally. Ophiopogon japonicus, a multifunctional plant extensively used in traditional Chinese medicine, has demonstrated potential in environmental remediation. This study investigated the Cd accumulation pattern of O. japonicus under cadmium stress and identified the heavy metal ATPase (HMA) family members in this plant. Our results demonstrated that O. japonicus exhibited a Cd enrichment factor (EF) of 2.75, demonstrating strong potential for soil Cd pollution remediation. Nine heavy metal ATPase (HMA) members of P1B-ATPases were successfully identified from the transcriptome data of O. japonicus, with OjHMA1-OjHMA6 classified as the Zn/Co/Cd/Pb-ATPases and OjHMA7-OjHMA9 as the Cu/Ag-ATPases. The expression levels of OjHMA1, OjHMA2, OjHMA3, and OjHMA7 were significantly up-regulated under Cd stress, highlighting their crucial roles in cadmium ion absorption and transport. The topological analysis revealed that these proteins possessed characteristic transmembrane (TM) segments of the family, along with functional A, P, and N domains involved in regulating ion absorption and release. Metal ion-binding sites (M4, M5, and M6) existed on the TM segments. Based on the number of transmembrane domains and the residues at metal ion-binding sites, the plant HMA family members were categorized into three subgroups: P1B-1 ATPases, P1B-2 ATPases, and P1B-4 ATPases. Specifically, the P1B-1 ATPase subgroup included the motifs TM4(CPC), TM5(YN[X]₄P), and TM6(M[XX]SS); the P1B-2 ATPase subgroup featured the motifs TM4(CPC), TM5(K), and TM6(DKTGT); the P1B-4 ATPase subgroup contained the motifs TM4(SPC) and TM6(HE[X]GT), all of which were critical for protein functions. Molecular docking results revealed the importance of conserved sequences such as CPC/SPC, DKTGT, and HE[X]GT in metal ion coordination and stabilization. These findings provide potential molecular targets for enhancing Cd uptake and tolerance of O. japonicus by genetic engineering and lay a theoretical foundation for developing new cultivars with high Cd accumulation capacity.
Cadmium/metabolism* ; Adenosine Triphosphatases/metabolism* ; Ophiopogon/drug effects* ; Soil Pollutants/toxicity* ; Plant Proteins/metabolism* ; Stress, Physiological ; Multigene Family ; Gene Expression Regulation, Plant

Echinocandin B (ECB) is a key precursor of the antifungal drug anidulafungin. It is a secondary metabolite of Aspergillus nidulans, and its titer in fermentation is significantly affected by the ECB synthesis pathway and cell morphology. In this study, the key genes related to the transcription activation, hydroxylation, and cell morphology during ECB biosynthesis were investigated to increase the fermentation titer of ECB and to change the cell morphology of Aspergillus nidulans to reduce the viscosity of the fermentation broth. The results indicated that after overexpression of ecdB and ecdK, the ECB titer increased by 25.8% and 23.7%, respectively, compared with that of the wild-type strain, reaching (2 030.5±99.2) mg/L and (1 996.4±151.4) mg/L. However, the deletion of fksA associated with cell wall synthesis resulted in damage to the cell wall, affecting strain growth and product synthesis. The engineered strain overexpressing ecdB was fermented in a 50-L bioreactor, in which the ECB titer reached 2 234.5 mg/L. The findings laid a research foundation for the subsequent metabolic engineering of this strain.
Fermentation ; Aspergillus nidulans/genetics* ; Echinocandins/genetics* ; Bioreactors/microbiology* ; Fungal Proteins/biosynthesis* ; Metabolic Engineering

Biofilm formation is one of the key reasons that bacterial infections are difficult to treat.So it is of great significance to develop effective strategies to resist bacterial biofilms.Although antibiotics are important clinical tools for the treatment of bacterial infections,their therapeutic efficacy is often unsatisfactory when targeting bacterial biofilm-associated diseases.In this study,exopolysaccharides(EPS)from Escherichia coli(E.coli)were extracted and purified.It was demonstrated that the obtained E.coli EPS had the ability to inhibit methicillin-resistant Staphylococcus aureus(MRSA)biofilm formation and disperse a mature biofilm.To improve the anti-biofilm effect of vancomycin(VAN),E.coli EPS was used in combination with VAN.The combination increased the inhibition rate of MRSA biofilm and increased the dispersion rate of mature biofilm from 10%to 80%.When combined with E.coli EPS,the number of bacterial colonies within the MRSA biofilm remarkably decreased by 88%,resulting in a significant improvement over the use of VAN alone at an equivalent concentration.Meanwhile,E.coli EPS could down-regulate the expression of MRSA biofilm-related genes.E.coli EPS showed good anti-biofilm effect,and E.coli EPS/VAN combination could provided a potential strategy for treatment of MRSA biofilm infections.

Objective:To investigate the relationship between oxygen consumption (VO 2), carbon dioxide production (VCO 2), and Oxygen Consumption/lactate (VO 2/Lac) with risk of death in patients with severe ARDS. Methods:A retrospective cohort study method was used, and the study subjects were hospitalized for >5 days adult patients with severe ARDS in the central intensive care unit of Henan Provincial People's Hospital from 1 March 2020 to 30 June 2023. The following patients were excluded: IC test was not completed on the 4th day of ICU admission, IC test results were unreliable, mechanical ventilation duration had exceeded 48 h at the time of ICU transfer or admission, palliative care patients and pregnant and parturient women. Using indirect calorimetry to determine VO 2 and VCO 2 values on the 4th day of admission, reviewing medical records to obtain general condition, disease information, blood gas analysis (including lactate value), diagnostic and therapeutic measures, and following up deaths by telephone and time of death. The primary outcome measure was death at 90 days, and the secondary outcome measure was death at 28 days, length of stay in ICU, total length of stay, and total hospitalization cost. Cox regression analysis and linear regression analysis were used to investigate the relationship between VO 2, VCO 2, VO 2/Lac and primary and secondary outcome indexes. Results:A total of 216 patients were enrolled, 78 patients (36.1%) died and 138 patients (63.9%) survived at 90 days. After correction for confounders, the results of multifactorial Cox regression analysis suggested that compared with the Q4 group, HR (95% CI) for 90-day risk of death in the VO 2 Q1 and Q2 groups was 3.21 (1.38, 7.49) and 3.24 (1.42, 7.38), and HR (95% CI) for 90-day risk of death in the VCO 2 Q1, Q2 and Q3 groups was 5.88 (2.33, 14.84), 4.26 (1. 60, 11.34) and 3.54 (1.34, 9.35), respectively, and the HR (95% CI) for 90-day risk of death in the VO 2/Lac Q1, Q2 and Q3 groups were 8.72 (3.01, 25.25), 8.43 (2.91, 24.47) and 4.04 (1.34, 12.17) respectively. P-trends were all <0.05, indicating that VO 2, VCO 2 and VO 2/Lac were linearly and negatively associated with the risk of 90-day mortality. In addition, VO 2, VCO 2, and VO 2/Lac were negatively associated with 28-day risk of death and higher VO 2/Lac was negatively associated with length of ICU stay. Conclusions:VO 2, VCO 2 and VO 2/Lac were negatively associated with 90-day mortality risk and 28-day mortality risk in patients with severe ARDS and may be independent risk factors predicting mortality risk of such patients.