T7 RNA polymerase (T7 RNAP) is one of the simplest known RNA polymerases. Its unique structural features make it a critical model for studying the mechanisms of RNA synthesis. This review systematically examines the static crystal structure of T7 RNAP, beginning with an in-depth examination of its characteristic “thumb”, “palm”, and “finger” domains, which form the classic “right-hand-like” architecture. By detailing these structural elements, this review establishes a foundation for understanding the overall organization of T7 RNAP. This review systematically maps the functional roles of secondary structural elements and their subdomains in transcriptional catalysis, progressively elucidating the fundamental relationships between structure and function. Further, the intrinsic flexibility of T7 RNAP and its applications in research are also discussed. Additionally, the review presents the structural diagrams of the enzyme at different stages of the transcription process, and through these diagrams, it provides a detailed description of the complete transcription process of T7 RNAP. By integrating structural dynamics and kinetics analyses, the review constructs a comprehensive framework that bridges static structure to dynamic processes. Despite its advantages, T7 RNAP has a notable limitation: it generates double-stranded RNA (dsRNA) as a byproduct. The presence of dsRNA not only compromises the purity of mRNA products but also elicits nonspecific immune responses, which pose significant challenges for biotechnological and therapeutic applications. The review provides a detailed exploration of the mechanisms underlying dsRNA formation during T7 RNAP catalysis, reviews current strategies to mitigate this issue, and highlights recent progress in the field. A key focus is the semi-rational design of T7 RNAP mutants engineered to minimize dsRNA generation and enhance catalytic performance. Beyond its role in transcription, T7 RNAP exhibits rapid development and extensive application in fields, including gene editing, biosensing, and mRNA vaccines. This review systematically examines the structure-function relationships of T7 RNAP, elucidates the mechanisms of dsRNA formation, and discusses engineering strategies to optimize its performance. It further explores the engineering optimization and functional expansion of T7 RNAP. Furthermore, this review also addresses the pressing issues that currently need resolution, discusses the major challenges in the practical application of T7 RNAP, and provides an outlook on potential future research directions. In summary, this review provides a comprehensive analysis of T7 RNAP, ranging from its structural architecture to cutting-edge applications. We systematically examine: (1) the characteristic right-hand domains (thumb, palm, fingers) that define its minimalistic structure; (2) the structure-function relationships underlying transcriptional catalysis; and (3) the dynamic transitions during the complete transcription cycle. While highlighting T7 RNAP’s versatility in gene editing, biosensing, and mRNA vaccine production, we critically address its major limitation—dsRNA byproduct formation—and evaluate engineering solutions including semi-rationally designed mutants. By synthesizing current knowledge and identifying key challenges, this work aims to provide novel insights for the development and application of T7 RNAP and to foster further thought and progress in related fields.

Objective To explore the antitumor effects of metformin on ovarian cancer cells in vitro, particularly on tumor cell proliferation, cell cycle, apoptosis, migration, and possible mechanism. Methods Ovarian cancer cell lines (A2780, CAOV3, and SKOV3) were treated with different concentrations of metformin. Their proliferation was explored using the MTT and clone formation assays, cell migration was examined using the scratch and Transwell assays, and cell cycle and apoptosis were examined using flow cytometry. In addition, metformin’s effects on the phosphorylation of AMPK and mTOR and the expression of CXCR4 and Wnt/β-catenin protein was measured by Western blot. Results The survival rates of ovarian cancer cells decreased significantly with increasing metformin concentration and metformin treatment time. The IC₅₀ values of metformin at 48 h for A2780, CAOV3, and SKOV3 cells were 16.36, 36.65, and 43.44 mmol/L, respectively. Compared with the control group, the clone formation ability and cell migration ability of ovarian cancer cells were significantly inhibited by metformin treatment and cell cycle arrested at the G₀/G₁ phase, and the apoptosis rate increased. As metformin concentration increased, the expression of phosphorylated AMPK protein gradually increased, and the expression levels of phosphorylated mTOR, CXCR4, Dvl3, β-catenin, cyclin D1, and CDK1 decreased. Conclusion Metformin exerts an antitumor effect on ovarian cancer cells, which is related to the activation of AMPK to inhibit CXCR4-mediated Wnt/β-catenin signaling pathway.

Humans ; Vascular Stiffness ; Coal Mining ; Occupational Diseases/epidemiology* ; Risk Factors ; Coal ; Miners

In this study, fluvoxamine maleate sustained-release pellet system tablets were prepared and were used to evaluate their release behaviors in vitro. Fluvoxamine maleate pellets were prepared using centrifugal-spherization method and coated by fluidized bed as bottom-spray. The multi-unit sustained-release pellets and appropriate excipients for prescription volumes were mixed uniformly and then compressed to tablets. Screening and determining the optimal formulation of drug loaded pellets through L8 (2⁴) Taguchi experiment. Using Minitab software to design a DOE experiment with 2⁴ partial factors, including material temperature, fan speed, atomization pressure, and spray rate to optimize the bottom spray coating process. Taking monostearate glycerol ester with a particle size of 24-40 mesh as the main diluent for tableting to relieve the delamination phenomenon between pellets and excipients during tablet pressing and reduce mechanical damage to the coating film. By examining the powder fluidity indexes such as angle of repose, bulk density, tapped density, and Hausner ratio of mixed particles, it was found that the flowability and compressibility are good and suitable for direct compression. Evaluate the basic properties of the sustained-release tablets, investigate the in vitro release behavior and study the release mechanism. The results of in vitro release test showed that the self-made sustained-release tablets could disintegrate into independent pellet units in phosphate buffer at pH 6.8 and release slowly within 24 h, which conformed to the first-order drug release model. The fluvoxamine maleate sustained-release pellet system tablets meet the requirements of preparation design and has a great commercial prospect.

Objective:To discuss the effect of royal jelly acid(10-HDA)on the proliferation and migration of the human colon cancer SW620 cells based on the network pharmacology,and to clarify its related molecular mechanism.Methods:The active ingredients such as 10-HDA and their corresponding targets were retrieved by using the keyword"royal jelly"from the Traditiomal Chinese Medicine Systems Pharmacology(TMSCP)Database and the Traditiomal Chinese Medicine Integrated Database(TCMID);the small molecule targets were predicted by the Swiss Target Prediction Database.The GeneCards Database and the Online Mendelian Inheritance in Man(OMIM)Database were used to obtain the targets with the keyword"Colon Cancer";the protein-protein interaction(PPI)network was constructed by using the String Database and Cytoscape 3.8.0 Software to screen the core targets;the Gene Ontology(GO)function enrichment analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG)signaling pathway enrichment analysis were analyzed by Metascape Database;the specific ingredient 10-HDA was screened for the in vitro activity experiments.The human colon cancer SW620 cells with good growth status were divided into control group and different doses(1,5,10,15,and 20 mmol·L-1)of 10-HDA groups.The viabilities of the cells in various groups were detected by MTT method and the survival rates of the cells were calculated.The SW620 cells were divided into control group,low dose(5 mmol·L-1)of 10-HDA group,middle dose(10 mmol·L-1)of 10-HDA group,and high dose(15 mmol·L-1)of 10-HDA group;Hoechst33342 staining method was used to observe the morphology of the cells in various groups;cell scratch test was used to detect the scratch healing rates of the cells in various groups;flow cytometry was used to detect the percentages of the cells at different cell cycles in various groups;biochemical method was used to detect the activities of total antioxidant capacity(T-AOC)and superoxide dismutase(SOD)in the cells in various groups;Western blotting method was used to detect the expression levels of B-cell lymphoma 2(Bcl-2),Bcl-2-associated X protein(Bax),cysteine-containing aspartate proteolytic enzyme-3(Caspase-3),cysteine-containing aspartate proteolytic enzyme-9(Caspase-9),glycogen synthase kinase 3β(GSK3β),β-catenin,and cyclin D1 proteins in the cells in various groups.Results:Six active ingredients of royal jelly were screened out by the TCMSP Database,and 28 core targets of 10-HDA in the treatment of colon cancer were obtained.The GO function enrichment analysis mainly included the signaling pathways such as cell proliferation and apoptosis.The KEGG signaling pathway enrichment analysis included the cell cycle,prostate cancer,cell senescence,and p53 signaling pathways;the GSK3β/β-catenin signaling pathway was closely related to the cell cycle.Compared with control group,the viabilities of the cells in 5,10,15,and 20 mmol·L-110-HDA groups were decreased in a dose-dependent manner(P<0.05 or P<0.01),the numbers of apoptotic cells in different doses of 10-HDA groups were significantly increased,and the scratch healing rates of the cells were significantly decreased(P<0.05 or P<0.01);the percentages of the cells at S phase in middle and high doses of 10-HDA groups were significantly increased(P<0.05 or P<0.01),the activities of T-AOC and SOD in the cells in different doses of 10-HDA groups were significantly decreased(P<0.05 or P<0.01).Compared with control group,the expression level of Bcl-2 protein in the cells in low dose of 10-HDA group was significantly decreased(P<0.01),and the expression level of GSK3β protein was significantly increased(P<0.05);compared with control group,the expression levels of Bax,Caspase-3,Caspase-9,and GSK3β proteins in the cells in middle and high doses of 10-HDA groups were significantly increased(P<0.05 or P<0.01),and the expression levels of Bcl-2,β-catenin,and CyclinD1 proteins were significantly decreased(P<0.01).Conclusion:10-HDA can significantly inhibit the proliferation and migration of the colon cancer cells and promote the apoptosis and oxidation levels of the colon cancer cells,and its mechanism may be related to the activation of the GSK3β/β-catenin signaling pathway.

Objective:To study influence of Connect-Introduce-Communicate-Ask-Respond-Exit(CICARE)communication mode on patients with acute heart failure(AHF).Methods:A total of 156 AHF patients treated in our hospital were randomly and equally divided into routine nursing group and CICARE group(received CICARE communication mode based on routine nursing group).Both groups were intervened for one month.General clinical data,hospitalization indexes,scores of Hamilton rating scale for depression(HAMD),Hamilton rating scale for anxiety(HAMA),general self-efficacy scale(GSES)and quality of life scale(QOL-35)before and after inter-vention and incidence of complications were compared between two groups.Results:Compared with routine nursing group,there were significant reductions in first aid time[(42.06±9.77)s vs.(20.27±3.77)s],visit time[(95.67±23.18)min vs.(50.07±11.21)min],admission time[(3.22±0.36)min vs.(2.60±0.67)min]and hospital stay[(22.33±4.82)d vs.(14.13±2.42)d];and scores of HAMD[(14.02±1.42)scores vs.(6.04± 1.57)scores]and HAMA[(13.24±2.07)scores vs.(7.16±2.17)scores]after intervention,and significant rise in scores of GSES[(14.25±3.14)scores vs.(32.03±6.06)scores]and QOL-35[(70.67±5.75)scores vs.(86.93±5.51)scores]in CICARE group after intervention(P=0.001 all).Incidence rate of complications in CICARE group was significantly lower than that of CICARE group(5.13％vs.20.51％,P=0.004).Conclusion:CICARE communication mode can significantly alleviate adverse emotions and improve self-efficacy in patients with acute heart failure.

Immunoassays are widely used in medicine, food, environment and other fields due to having the advantages of simpleness, rapidness and accuracy. Combining immunoassays with nanomaterials can improve the performance of immunoassays. Compared with traditional nanomaterials, upconversion nanoparticles (UCNPs) have excellent optical properties such as good photostability, long luminescence lifetime and narrow and tunable emission bands, which can significantly reduce background noise and improve analytical sensitivity when combined with immunoassay. This paper briefly introduces the luminescence mechanism of UCNPs, summarizes the synthesis and surface modification methods of UCNPs. And then 5 UCNPs-based immunoassay techniques, namely, fluorescence resonance energy transfer, inner filter effect, magnetic separation technique, upconversion-linked immunosorbent assay and upconversion immunochromatography, are discussed in detail. These sensing protocols of UCNPs-based immunoassays have been successfully utilized to detect various targets, including small molecules, macromolecules, and pathogens, all of which closely related to food safety, human health, and environmental pollution. Finally, the challenges and prospects of this technique are summarized and prospected. Although the UCNPs immunoassays based on antibodies and antigens have made great progress, most of the research is still in the stage of laboratory, and there is a long way to go to realize its social applications. There is a series of challenges need to be overcome. (1) Designing excellent water soluble and dispersive upconversion nanomaterials is needed. Hydrophilic ligands are bound to smaller upconversion nanoparticles and removing hydrophobic surface ligands are the most widely used methods to improve solubility and dispersity. (2) Multi-detection technology platforms and multi-mode simultaneous detection platforms have great potential, which will improve the efficiency of point of care detection. (3) The researchers also need to focus on some important problems. For examples, the upconversion luminescence efficiency of UCNPs is difficult to maintain, the synthesis method is complex, and the surface modification degree and functionalization are difficult to control.

Objective To study the effect of ligustilide regulating stimulator of interferon genes(STING)/Tank-binding kinase 1(TBK1)/nuclear factor-κB(NF-κB)signaling on lung tissue damage in mouse model of lipopolysaccharide(LPS)-induced acute lung injury.Methods Mice were divided into control group,model group(LPS lung injury mouse model),experimental-L group(LPS lung injury mouse model,20 mg·kg-1 ligustilide treatment),experimental-M group(LPS lung injury mouse model,60 mg·kg-1 ligustilide treatment),experimental-H group(LPS lung injury mouse model,100 mg·kg-1 ligustilide treatment),DMXAA group(LPS lung injury mouse model,100 mg·kg-1 ligustilide,STING signal agonist DMXAA treatment),Western blot was used to detect the STING,p-TBK1,TBK1,p-p65,p65 protein expression,bicinchoninic acid(BCA)method was used to detect total protein in bronchoalveolar lavage fluid,Swiss Giemsa staining was used to count the number of inflammatory cells in bronchoalveolar lavage fluid,the content of tumor necrosis factor-alpha(TNF-α)was detected by enzyme-linked immunosorbent assay(ELISA),and the content of malondialdehyde(MDA)in lung tissue was detected by thiobarbituric acid method.Results The relative expression levels of STING protein in the control,model,experimental-L,experimental-M,experimental-H groups,and DMXAA group were 0.13±0.03,0.46±0.02,0.36±0.04,0.27±0.02,0.20±0.03 and 0.38±0.04,p-TBK1/TBK1 protein ratios were 0.15±0.02,0.56±0.02,0.43±0.01,0.31±0.01,0.20±0.02 and 0.30±0.02,p-p65/p65 protein ratios were 0.24±0.01,0.66±0.03,0.41±0.02,0.32±0.04,0.22±0.02 and 0.42±0.03,the total protein contents in bronchoalveolar lavage fluid were(173.79±15.44),(304.21±19.29),(243.59±17.60),(212.51±18.24),(187.11±11.59)and(241.69±30.12)μg·mL-1;the number of macrophages were(0.11±0.02)×108,(0.94±0.09)×108,(0.72±0.08)×108,(0.57±0.04)×108,(0.41±0.04)×108 and(0.71±0.08)×108 cell·mL-1.The difference of the above indicators between model group and control group were all statistically significant(all P＜0.05);the difference between experimental-L,experimental-M,experimental-H groups and model group were all statistically significant(all P＜0.05);there were statistically significant difference between DMXAA group and experimental-H group(all P＜0.05).Conclusion Ligustolide inhibits STING/TBK1/NF-κB signaling to alleviate lung tissue damage in a mouse model of LPS-induced acute lung injury.

Objective To investigate the function of Frizzled 2(FZD2)in mouse tongue squamous cell carcinoma and its effect on cytotoxic T lymphocyte-associated antigen 4(CTLA4)monoclonal antibody.Methods Cell experiment:SCCVII mouse tongue squamous cell carcinomq cells were divided into blank control group(transfected LV-kdCon)and experimental group(transfected LV-kdFZD2).Cell proliferation ability was detected by cell counting kit-8(CCK-8);migration ability was detected by Transwell cell assay;and angiogenesis ability was verified by human umbilical vein endothelial cells.Animal experiments:Female C3H/He mice were constructed with tumor bearing mice model.Mice were divided into control group[injected with phosphate buffer solution(PBS)],kdFZD group(inoculated with experimental cells and injected with an equal amount of PBS),αCTLA4 group(inoculated with blank control cells subcutaneously and injected with CTLA4 monoclonal antibody)and kdFZD+αCTLA group(inoculated with experimental cells subcutaneously and injected with CTLA4 monoclonal antibody).The mRNA expression of tumor tissue was detected by quantitative polymerase chain reaction(qPCR),and the tumor volume and mass were measured.Results The relative expression levels of FZD2 mRNA in the control group and the experimental group were 1.01±0.18 and 0.52±0.18;the cell migration numbers were 466.70±44.10 and 160.00±26.46;the number of branch nodes of human umbilical vein endothelial cells were 108.70±6.35 and 84.33±10.02;the total capillary length were(20 235±2 229)and(16 549±338)μm,respectively,with statistical significance(P＜0.05,P＜0.01).The tumor volumes of control group,kdFZD group,αCTLA4 group and kdFZD+αCTLA group were(449.50±114.80),(131.10±13.49),(83.62±26.47)and(2.45±0.91)mm3;the tumor weights were(0.78±0.11),(0.22±0.06),(0.13±0.02)and(0.03±0.01)g,respectively,and the differences were statistically significant(P＜0.001,P＜0.000 1).Conclusion FZD2 can be used as a potential therapeutic target for tongue squamous cell carcinoma and is expected to be a key molecule in the optimization of adjuvant immunotherapy for tongue squamous cell carcinoma.

Objective The purpose of this study was to investigate the bacterial communities of biting midges and ticks collected from three sites in the Poyang Lake area,namely,Qunlu Practice Base,Peach Blossom Garden,and Huangtong Animal Husbandry,and whether vectors carry any bacterial pathogens that may cause diseases to humans,to provide scientific basis for prospective pathogen discovery and disease prevention and control. Methods Using a metataxonomics approach in concert with full-length 16S rRNA gene sequencing and operational phylogenetic unit(OPU)analysis,we characterized the species-level microbial community structure of two important vector species,biting midges and ticks,including 33 arthropod samples comprising 3,885 individuals,collected around Poyang Lake. Results A total of 662 OPUs were classified in biting midges,including 195 known species and 373 potentially new species,and 618 OPUs were classified in ticks,including 217 known species and 326 potentially new species.Surprisingly,OPUs with potentially pathogenicity were detected in both arthropod vectors,with 66 known species of biting midges reported to carry potential pathogens,including Asaia lannensis and Rickettsia bellii,compared to 50 in ticks,such as Acinetobacter lwoffii and Staphylococcus sciuri.We found that Proteobacteria was the most dominant group in both midges and ticks.Furthermore,the outcomes demonstrated that the microbiota of midges and ticks tend to be governed by a few highly abundant bacteria.Pantoea sp7 was predominant in biting midges,while Coxiella sp1 was enriched in ticks.Meanwhile,Coxiella spp.,which may be essential for the survival of Haemaphysalis longicornis Neumann,were detected in all tick samples.The identification of dominant species and pathogens of biting midges and ticks in this study serves to broaden our knowledge associated to microbes of arthropod vectors. Conclusion Biting midges and ticks carry large numbers of known and potentially novel bacteria,and carry a wide range of potentially pathogenic bacteria,which may pose a risk of infection to humans and animals.The microbial communities of midges and ticks tend to be dominated by a few highly abundant bacteria.