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.

Cellulose synthase (CesA), one of the key enzymes in the biosynthesis of cellulose in plants, plays an important role in plant growth and plant resistance. In this study, a total of 21 AsCesA genes from Aquilaria sinensis were systematically identified and the physico-chemical characteristics were analyzed based on genome database and bioinformatical methods. The phylogenetic tree was constructed and the gene location on chromosome, cis-acting elements in the 2 000 basepairs upstream regulatory regions and conservative motifs were analyzed. The AsCesA proteins were mainly located on the plasma membrane. The number of amino acids of the proteins ranged from 390 to 1 261. The isoelectric point distributed from 5.67 to 8.86. All of the 21 AsCesA proteins possessed the transmembrane domains, the number of which was from 6 to 8. The genes were classified into 3 groups according to the phylogenetic relationship. Obvious differences were observed in motif composition in genes from different groups. However, motif2, motif6, motif7 and motif10 were observed in all of AsCesA proteins. Analysis of cis-acting elements indicated that AsCesA genes family has cis-acting elements related to plant hormones, abiotic stresses, and biological processes. Seven AsCesA genes with differential expression were selected according to the calli transcriptome data induced by NaCl at different times and their expression levels under different abiotic stresses were analyzed by quantitative real-time PCR. The results indicated that salt, low temperature, drought, and heavy metal stresses could affect the expression level of AsCesA genes, and the abundance of AsCesA1, AsCesA3 and AsCesA20 showed a significant change, implying their potential important roles to the abiotic stresses. The accumulation pattern of cellulose content under different abiotic stresses was similar to the expression trend of AsCesA genes. Our results provide valuable insights into the role of cellulose synthase in A.sinensis in plant defense.

ObjectiveTo observe the effect of Banxia Xiexintang （BXT） on the proliferation of human gastric cancer HGC-27， MKN-45， and AGS cells and its mechanism. MethodCell counting kit-8 （CCK-8） was used to detect the effects of different concentrations of BXT-containing serum （5%， 10%， and 20%） on the proliferation of HGC-27， MKN-45， and AGS cells. A mitochondrial membrane potential probe （TMRE） was used to detect the expression of mitochondrial membrane potential in cells. A kit was used to detect iron ion （Fe²⁺） content， lipid peroxide （LPO）， and superoxide dismutase （SOD） activity. Western blot was used to detect the protein expression levels of glycogen synthase3β （GSK3β）， phosphorylated GSK3β （p-GSK3β）， nuclear factor E₂ related factor 2 （Nrf2）， and glutathione peroxidase 4 （GPX4）. The real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） was used to detect the mRNA expression of member 11 of the cystine/glutamic acid reverse transporter solute vector family 7 （SLC7A11）， member 2 of the heavy chain solute vector family 3 （SLC3A2）， transferrin receptor 3 （TFRC）， and tumor protein （TP）53. ResultCCK-8 results showed that BXT and capecitabine could significantly reduce the survival rate of three kinds of gastric cancer cells after treatment with drug-containing serum for 24 h （P<0.01）. After 48 h of intervention with drug-containing serum， the survival rate of three kinds of gastric cancer cells was significantly decreased in both the capecitabine group and the BXT group compared with the blank group. The BXT group was dose-dependent， with 20% BXT having the most significant effect （P<0.01）. In terms of biochemical indicators of ferroptosis， compared with the blank group， BXT and capecitabine significantly decreased the expression of mitochondrial membrane potential （P<0.01） and SOD activity （P<0.01） and significantly increased the contents of LPO and Fe²⁺ （P<0.01）， so as to improve the sensitivity of gastric cancer cells to ferroptosis. In terms of the Nrf2/GPX4 pathway， compared with the blank group， the BXT group could reduce the protein expressions of p-GSK3β， Nrf2， and GPX4 （P<0.01） in gastric cancer cells and increase mRNA expressions of SLC7A11 and SLC3A2 （P<0.05）. It could also increase the protein expression of GSK3β （P<0.01） and mRNA expression of TP53 and TFRC （P<0.05， P<0.01） in gastric cancer cells. Inhibition of the Nrf2/GPX4 pathway induces ferroptosis in gastric cancer cells. Compared with the capecitabine group， the 20% BXT group showed a more obvious effect. ConclusionBanxia Xiexintang can induce ferroptosis in gastric cancer cells HGC-27， MKN-45， and AGS by inhibiting the Nrf2/GPX4 pathway.

Objective To provide reference for the subsequent clinical application of WBV,based on the impacts of whole body vibration(WBV)with different frequencies on gross motor function and walking function in children with dyskinetic cerebral palsy.Methods 60 children aged 6～12 with dyskinetic cerebral palsy,who had been treated at the department of rehabilitation medicine in the Affiliated Southwest Medical University from October 2021 to November 2022,were selected.They were randomly divided into a control group(n = 20),(25±5)Hz group(n = 20),and(35±5)Hz group(n = 20).All the three groups received conventional rehabilitation,while the(25±5)Hz group received additional WBV with(25±5)Hz and the(35±5)Hz group received WBV with(35±5)Hz.They were treated for eight weeks.The scores on D and E domains of GMFM-88,TUGT,the score on Berg Balance Scale,and footprint analysis were used for assessment of the efficacy after treatment.Results As compared with the baselines,the scores were improved in the three groups after treatment(P＜0.001).BBS(F = 12.502),TUGT(F = 8.211),scores on D and E domains of GMFM-88(F = 12.802 and 8.505),stride length(F = 12.279),1MWT distance(F = 12.619),and step width(F = 13.582)were better in the(35±5)Hz group than in the(25±5)Hz group and the control group(P＜0.05 and P＜0.01);and the efficacy was better in the(25±5)Hz group than in the control group,the difference was statistically significant(P＜0.05 and P＜0.01).Conclusion WBV can improve trunk control,lower limb gross motor function,and walking function in children with involuntary motor type cerebral palsy.(35±5)Hz is better than(25±5)Hz for the efficacy of WBV.

ObjectiveAlthough expression of the TEAD1 protein in preadipocytes has been established, its function remains unclear. In this study, we sought to detect transcripts of TEAD1 in chicken and to examine the effects of this protein on the proliferation, migration, apoptosis, and differentiation of immortalized chicken preadipocyte cell lines (ICP1). MethodsThe full-length sequence of the TEAD1 gene was cloned and the two transcripts were subjected to bioinformatics analysis. The subcellsular localization of TEAD1 transcripts was determined based on indirect immunofluorescence. The effects of TEAD1 transcripts overexpression on the proliferation of ICP1 cells were examined by RT-qPCR, CCK-8, and EdU assays; the effects of TEAD1 transcripts on ICP1 cells migration were examined based on the scratch test; and the effects of TEAD1 transcripts overexpression on ICP1 cells apoptosis were analyzed using apoptosis-Hoechst staining and RT-qPCR. The expression of TEAD1 transcripts in different tissues, cells lines, and ICP1 at different periods of differentiation was analyzed by RT-qPCR. The effects of TEAD1 transcripts overexpression on lipid droplet accumulation and adipogenic-related gene expression in ICP1 cells were analyzed based on Oil Red O and BODIPY staining, RT-qPCR, Western blot, and dual-luciferase reporter gene assays. Finally, the content of triglyceride (TG) was measured in TEAD1 overexpressed ICP1 cells. ResultsThe full-length TEAD1 was cloned and two TEAD1 transcripts were identified. The TEAD1-V1 protein was found to be localized primarily in the cell nucleus, whereas the TEAD1-V2 protein is localized in the cell cytoplasm and nucleus. The overexpression of both TEAD1-V1 and TEAD1-V2 significantly inhibited the proliferation of ICP1 cells. Whereas the overexpression of TEAD1-V1 promoted ICP1 cell migration, the overexpression of TEAD1-V2 had no significant effects on ICP1 migration; the overexpression of both TEAD1-V1 and TEAD1-V2 significantly promoted the apoptosis of ICP1 cells. We found that the different transcripts of TEAD1 have similar expression pattern in different tissues and cells lines. During induced preadipocyte differentiation, the expression of these genes initially declined, although subsequently increased. Overexpression of TEAD1-V1 promoted a significant reduction in lipid droplet formation and inhibited C/EBPα expression during the differentiation of ICP1 cells (P<0.05). However, the overexpression of TEAD1-V2 had no significant effect on lipid droplet accumulation or the expression of adipogenic-related proteins (P>0.05). Overexpression of TEAD1-V1 significantly decreased triglyceride content in ICP1 cells (P<0.05), while overexpression of TEAD1-V2 had no effect on triglyceride content in ICP1 cells (P>0.05). ConclusionIn this study, for the first time, identified two TEAD1 transcripts. Overexpressed transcripts TEAD1-V1 and TEAD1-V2 both inhibited the proliferation of chicken preadipocytes and promoted apoptosis of chicken preadipocytes. TEAD1-V1 inhibited the differentiation of preadipocytes and promoted the migration of preadipocytes, while TEAD1-V2 had no effect on the differentiation and migration of preadipocytes.

Existing studies have underscored the pivotal role of N-acetyltransferase 10 (NAT10) in various cancers. However, the outcomes of protein-protein interactions between NAT10 and its protein partners in head and neck squamous cell carcinoma (HNSCC) remain unexplored. In this study, we identified a significant upregulation of RNA-binding protein with serine-rich domain 1 (RNPS1) in HNSCC, where RNPS1 inhibits the ubiquitination degradation of NAT10 by E3 ubiquitin ligase, zinc finger SWIM domain-containing protein 6 (ZSWIM6), through direct protein interaction, thereby promoting high NAT10 expression in HNSCC. This upregulated NAT10 stability mediates the enhancement of specific tRNA ac⁴C modifications, subsequently boosting the translation process of genes involved in pathways such as IL-6 signaling, IL-8 signaling, and PTEN signaling that play roles in regulating HNSCC malignant progression, ultimately influencing the survival and prognosis of HNSCC patients. Additionally, we pioneered the development of TRMC-seq, leading to the discovery of novel tRNA-ac⁴C modification sites, thereby providing a potent sequencing tool for tRNA-ac⁴C research. Our findings expand the repertoire of tRNA ac⁴C modifications and identify a role of tRNA ac⁴C in the regulation of mRNA translation in HNSCC.
Humans ; DNA-Binding Proteins ; Head and Neck Neoplasms/genetics* ; N-Terminal Acetyltransferases ; RNA, Transfer ; Serine ; Signal Transduction ; Squamous Cell Carcinoma of Head and Neck

Background: Twenty-four-hour urinary free cortisol (UFC) measurement is the initial diagnostic test for Cushing’s syndrome (CS). We compared UFC determination by both direct and extraction immunoassays using Abbott Architect, Siemens Atellica Solution, and Beckman DxI800 with liquid chromatography-tandem mass spectrometry (LC-MS/MS). In addition, we evaluated the value of 24-hr UFC measured by six methods for diagnosing CS. Methods: Residual 24-hr urine samples of 94 CS and 246 non-CS patients were collected.A laboratory-developed LC-MS/MS method was used as reference. UFC was measured by direct assays (D) using Abbott, Siemens, and Beckman platforms and by extraction assays (E) using Siemens and Beckman platforms. Method was compared using Passing–Bablok regression and Bland–Altman plot analyses. Cut-off values for the six assays and corresponding sensitivities and specificities were calculated by ROC analysis. Results: Abbott-D, Beckman-E, Siemens-E, and Siemens-D showed strong correlations with LC-MS/MS (Spearman coefficient r = 0.965, 0.922, 0.922, and 0.897, respectively), while Beckman-D showed weaker correlation (r = 0.755). All immunoassays showed proportionally positive bias. The areas under the curve were 0.975 for Abbott-D, 0.972 for LCMS/MS, 0.966 for Siemens-E, 0.948 for Siemens-D, 0.955 for Beckman-E, and 0.877 for Beckman-D. The cut-off values varied significantly (154.8–1,321.5 nmol/24 hrs). Assay sensitivity and specificity ranged from 76.1% to 93.2% and from 93.0% to 97.1%, respectively. Conclusions Commercially available immunoassays for measuring UFC show different levels of analytical consistency compared to LC-MS/MS. Abbott-D, Siemens-E, and Beckman-E have high diagnostic accuracy for CS.

Objective:To assess the applicability of fully automatic pipeline automated testing for internal quality control (automated quality control).Methods:Stability, assay efficiency and implementation costs of 18 biochemical tests, 5 immunoturbidimetric tests and 11 chemical illuminescent tests in the Department of Laboratory Medicine of Peking Union Hospital from January 2019 to July 2022 were evaluated using automated quality control implementation methods. The detailed method is as follows: quality control materials for biochemical, immunoturbidimetric and chemiluminescent tests were stored in the refrigerator in the pipeline which was controlled by the intermediate software, and were automatically retrieved and tested as pre-set followed by documenting and storing. The quality control setup for the biochemical tests included refreshing quality control materials daily and weekly,both of which were paralleled for 3 months. The on-line storage stability of quality control materials in the pipeline was evaluated by comparing the coefficients of variation ( CV) of the quality control results between the two patterns. Effect of automated quality control application was evaluated using 6 indicators, including the results′ variation of automatically performed and manually performed quality controls, the out-of-controlled rate, the consumption of quality control materials, the change of staff workload, the impact on the testing time of the first sample, and the failure rate of automated quality control. Results:(1) Storage stability of quality control materials in the pipeline: under the pattern of weekly refresh of the biochemical quality control materials, except for total carbon dioxide (TCO 2) (the CVs of low and high level quality control were respectively 20.24% and 21.82%) and sodium (the CV of low level quality control was 1.51%) that were greater than the allowable variation set by the laboratory, the CVs of the rest tests meet the lab requirements on the allowable variations. (2) The results′ variation of quality control in automatically performed and manually performed control patterns: in the patterns of daily refresh of biochemical quality control materials and weekly refresh of immunoturbidimetric and chemiluminescent quality control materials, the CVs of both low and high levels of quality control were lower in the automatically performed control pattern than that in manually performed pattern for 8 chemiluminescent items of dehydroepiandrosterone sulfate, estradiol, follicle stimulating hormone, luteinizing hormone, serum ferritin, serum folic acid, vitamin B12 and testosterone, 3 immunologic items of complement 3, C reactive protein and immunoglobulin G, and 10 biochemical items of alkaline phosphatase, glucose, calcium, chloride, potassium, lactate dehydrogenase, sodium, urea, low density lipoprotein cholesterol, and adenosine deaminase. The out-of-control rates of biochemistry, immunoturbidimetric and chemiluminescence tests in both quality control patterns conformed with the clinical routine work requirements. (3) Comparison of quality control materials′ consumption: compared with manually performed quality control, weekly consumption of automatically performed chemiluminescent quality control materials decreased 37.5% (from 8 ml to 5 ml); weekly consumption of automatically performed immunoturbidimetric quality control materials decreased 33.3% (from 3 ml to 2 ml). (4)Comparison of staff workload and first sample testing time: compared with manually performed quality control, automatical quality control reduced manual work by about 156 steps per week, and the daily initial testing time was earlier by 15 min on average. The failure rate was 54.5% (37/64) during the early-stage application of the automated quality control which dropped to 10.2% (13/128) in the late-stage. Conclusion:The results of automated quality control detected in the pipeline system meet the quality indicators′ requirements of the laboratory, and the application of automated quality control can improve the quality control, save costs, reduce workload, and improve work efficiency.

Clinical application of mass spectrometry technology has attracted the attention of clinical laboratory experts due to its high sensitivity, high specificity, and capacities of simultaneous detection of multiple compounds. In recent years, mass spectrometry technology has made significant achievements in the fields of identification of pathogenic microorganism, detection of trace elements and heavy metals, small molecule hormones, vitamins, amino acids, peptides and proteins, as well as therapeutic drug monitoring (TDM) and poisoning drugs screening. In order to further clarify the opportunities and challenges brought by this complex mass spectrometry technology in the field of clinical laboratory, the Chinese Journal of Laboratory Medicine invited experts and scholars of laboratory medicine to share their experience and opinions on related items focusing on the positioning of mass spectrometry technology in the clinical laboratory, the development and improvement of the clinical laboratory by mass spectrometry technology, the challenges of interpreting mass spectrometry test results, the challenges of operating and managing clinical mass spectrometry laboratories, and ways of improving the application of clinical mass spectrometry laboratories with this technology. Agreement was achieved in that the introduction of mass spectrometry technology into the clinical laboratory could bring new directions and opportunities for clinical testing and research, and also is associated with a series of challenges such as the difficulty of sample pretreatment, the high cost and complexity of mass spectrometry technology, the complexity of data processing and interpretation, the lack of standards and norms, and the issue of determining the price of mass spectrometry examinations.

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) technology has the characteristics of high specificity and high throughput, making it rapidly applied and developed in the field of clinical testing. Its application in the monitoring of therapeutic drugs can effectively improve the quantitative accuracy and sensitivity, and formulate a personalized and optimal dosing plan for patients. However, this technology still faces some challenges, and automation, quality control, and quantitative traceability will be the future development direction.