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 investigate the effects of Danmu Extract Syrup (DMS) on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice and explore the mechanism. METHODS: Seventy-two male Balb/C mice were randomly divided into 6 groups according to a random number table (n=12), including control (normal saline), LPS (5 mg/kg), LPS+DMS 2.5 mL/kg, LPS+DMS 5 mL/kg, LPS+DMS 10 mL/kg, and LPS+Dexamethasone (DXM, 5 mg/kg) groups. After pretreatment with DMS and DXM, the ALI mice model was induced by LPS, and the bronchoalveolar lavage fluid (BALF) were collected to determine protein concentration, cell counts and inflammatory cytokines. The lung tissues of mice were stained with hematoxylin-eosin, and the wet/dry weight ratio (W/D) of lung tissue was calculated. The levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-6 and IL-1 β in BALF of mice were detected by enzyme linked immunosorbent assay. The expression levels of Claudin-5, vascular endothelial (VE)-cadherin, vascular endothelial growth factor (VEGF), phospho-protein kinase B (p-Akt) and Akt were detected by Western blot analysis. RESULTS: DMS pre-treatment significantly ameliorated lung histopathological changes. Compared with the LPS group, the W/D ratio and protein contents in BALF were obviously reduced after DMS pretreatment (P<0.05 or P<0.01). The number of cells in BALF and myeloperoxidase (MPO) activity decreased significantly after DMS pretreatment (P<0.05 or P<0.01). DMS pre-treatment decreased the levels of TNF-α, IL-6 and IL-1 β (P<0.01). Meanwhile, DMS activated the phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) pathway and reversed the expressions of Claudin-5, VE-cadherin and VEGF (P<0.01). CONCLUSIONS DMS attenuated LPS-induced ALI in mice through repairing endothelial barrier. It might be a potential therapeutic drug for LPS-induced lung injury.
Mice ; Male ; Animals ; Proto-Oncogene Proteins c-akt/metabolism* ; Lipopolysaccharides ; Phosphatidylinositol 3-Kinases/metabolism* ; Interleukin-1beta/metabolism* ; Vascular Endothelial Growth Factor A/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Claudin-5/metabolism* ; Acute Lung Injury/chemically induced* ; Lung/pathology* ; Interleukin-6/metabolism* ; Drugs, Chinese Herbal

ObjectiveHuman Ku70 protein mainly involves the non-homologous end joining (NHEJ) repair of double-stranded DNA breaks (DSB) through its DNA-binding properties, and it is recently reported having an RNA-binding ability. This paper is to explore whether Ku70 has RNA helicase activity and affects miRNA maturation. MethodsRNAs bound to Ku protein were analyzed by RNA immunoprecipitation sequencing (RIP-seq) and bioinfomatic anaylsis. The expression relationship between Ku protein and miRNAs was verified by Western blot (WB) and quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) assays. Binding ability of Ku protein to the RNAs was tested by biolayer interferometry (BLI) assay. RNA helicase activity of Ku protein was identified with EMSA assay. The effect of Ku70 regulated miR-124 on neuronal differentiation was performed by morphology analysis, WB and immunofluorescence assays with or without Zika virus (ZIKV) infection. ResultsWe revealed that the Ku70 protein had RNA helicase activity and affected miRNA maturation. Deficiency of Ku70 led to the up-regulation of a large number of mature miRNAs, especially neuronal specific miRNAs like miR-124. The knockdown of Ku70 promoted neuronal differentiation in human neural progenitor cells (hNPCs) and SH-SY5Y cells by boosting miR-124 maturation. Importantly, ZIKV infection reduced the expression of Ku70 whereas increased expression of miR-124 in hNPCs, and led to morphologically neuronal differentiation. ConclusionOur study revealed a novel function of Ku70 as an RNA helicase and regulating miRNA maturation. The reduced expression of Ku70 with ZIKV infection increased the expression of miR-124 and led to the premature differentiation of embryonic neural progenitor cells, which might be one of the causes of microcephaly.

Background Cognitive behavioral therapy(CBT)is a widely used and empirically supported psychotherapy method.In recent years,the localization of CBT related to culture has received increasing attention from Chinese scholars.However,there is still a lack of systematic research on the localization of CBT using idioms as materials.Objective To explore whether idioms reflect the mutual influence between the two core therapeutic elements of CBT(cognition and emotion)and to use them as CBT treatment tools among college students,so as to provide references for the localization of CBT.Methods Using the Xinhua Idiom Dictionary(second edition)published by the Commercial Press,a three-round manual screening method was used to select idioms that reflected the mutual influence between cognition and emotion in CBT.Based on the selected idioms,a survey questionnaire titled"survey on idiom understanding level"was developed.From August to October,2022,stratified sampling was conducted among college students from different majors and universities,and 815 valid questionnaires were obtained through the Questionnaire Star platform.By analyzing the understanding of each idiom among college students,idioms that could be used as CBT treatment tools were identified.Results In the Xinhua Idiom Dictionary(second edition),there were 13 idioms that reflected the influence of cognition on emotion and 5 idioms that reflected the influence of emotion on cognition.12 idioms could be used as CBT treatment tools,including 8 idioms that reflected the influence of cognition on emotion and 4 idioms that reflected the influence of emotion on cognition.Conclusion There may be idioms that reflect the mutual influence between the two core therapeutic elements of CBT(cognition and emotion)and these idioms can be attempted as a therapeutic tool for CBT among college students.

Objective To construct a 3D printed PLLA/β-tricalcium(PLLA/β-TCP)bone tissue engineering scaffold surface porous structure through simple treatment with NaOH solution,increase the roughness and hydrophilicity of the scaffold,and promote cell adhesion on the scaffold surface.Methods The PLLA/β-TCP mesh scaffold was prepared by 3D printing melt deposition molding technology,and the scaffold was roughed by NaOH etching.The effects of NaOH concentration and time on the scaffold were observed according to the microstructure,energy spectrum,contact angle,mechanics,and cell adhesion of the scaffold.Results The PLLA/β-TCP composite scaffold constructed by melt deposition technology had a pre-set porous structure,and the pores were interconnected.After NaOH etching,a porous structure with both macroscopic and microscopic pores was formed.The increase in any of the NaOH concentration and time parameters would lead to the increase of pore diameter and surface roughness.When the NaOH treatment parameter was 0.1 mol/L(9 h),it could significantly reduce the water contact angle on the surface of the scaffold,and had no significant effect on the compressive strength of the scaffold.In vitro cell testing showed that the surface porous composite scaffold etched with NaOH had more advantages in the adhesion and proliferation of BMSCs.Conclusion Using NaOH to process 3D printing of PLLA/β-TCP bone tissue engineering scaffolds can effectively improve the surface morphology of the scaffold,and optimize its hydrophilicity and cell adhesion.

Objective To solve the problem of insufficient hydrophilicity on the surface of polycaprolactone(PCL)/β-TCP bone tissue engineering scaffolds,NaOH etching method was used to improve the surface microstructure of 3D printed PCL/β-TCP scaffolds,further affecting their hydrophilicity and cell response.Methods PCL/β-TCP mesh scaffolds were prepared using 3D printing melt deposition molding technology,and the surface roughness of the scaffolds was modified by NaOH etching.The effects of two reaction parameters,NaOH concentration and time,on the microstructure,spectral elements,contact angle,compressive strength,and cell adhesion of the scaffolds before and after modification were observed.Results After NaOH etching,the surface microporous structure of the mesh scaffold was successfully prepared.With the increase of either NaOH concentration or time,the surface micropores of the scaffold increased while the contact angle of the material surface decreased.However,the compression strength of the etched scaffold treated with NaOH for 1 mol/L(24 h)or 10 mol/L(6 h)was not statistically significant compared to the untreated group(P＞0.05).The number of cells on the etched scaffold increased,with a larger spreading area of individual cells,making it more advantageous in the adhesion and proliferation of BMSCs.Conclusion The use of NaOH etching to improve the hydrophilicity of 3D printed PCL/β-TCP bone tissue engineering scaffolds is a low-cost and effective strategy which can effectively improve the wettability and cell adhesion of the scaffolds.

Objective To investigate the efficacies of proximal femoral nail anti-rotation(PFNA)internal fixation in traction bed supine position and non-traction bed lateral position in the treatment of elderly unstable femoral intertrochanteric fractures.Methods The clinical data of patients with unstable femoral intertrochanteric fractures treated with PFNA internal fixation in our hospital were retrospec-tively analyzed,41 patients received treatment in traction bed supine position were included in the supine position group,and 55 patients treated received treatment in non-traction bed lateral position were included in the lateral position group.The perioperative related indicators,surgical reduction,hip Harris score,and incidence of complications in the two groups were analyzed.Results The operation time and incision length of patients in the lateral position group were shorter than those in the supine position group,and the intraoperative blood loss and fluoroscopy times were less than those in the supine position group,with statistically significant differences(P<0.05).There was no significant difference in the anesthesia mode,blood transfusion or hospital stay of patients between the two groups(P>0.05).There was no significant difference in the incidence of postoperative complications of patients between the two groups(P>0.05).There was no significant difference in neck-shaft angle,tip-apex distance or hip Harris score of patients between the two groups(P>0.05).Conclusion PFNA internal fixation in traction bed supine position and non-traction bed lateral position have the same effect in the treatment of elderly unstable femoral intertrochanteric fractures,while the non-traction bed lateral position for treatment has more advantages in shortening operation time,decreasing intraoperative blood loss,and reducing radiation exposure.

Objective To analyze the influence of midazolam and propofol on sedation effect and blood gas indicators in elderly patients undergoing mechanical ventilation after cardiopulmonary bypass(CPB)cardiac surgery.Methods The elderly patients with mechanical ventilation after CPB cardiac surgery were grouped according to cohort method,including midazolam group(group M),propofol group(group P)and midazolam-propofol combined administration group(group M-P).Group M was treated with midazolam(intravenous injection of 0.05-0.10 mg kg-1 midazolam for sedation induction,and then continuously intravenous injection of 0.05-0.15 mg·kg-1·h-1 midazolam by micropump),and group P was treated with propofol(intravenous injection of 0.5 mg·kg-1 propofol for sedation induction,and then continuously intravenous injection of 0.5-2.0 mg·kg-1·h-1 propofol by micropump),and group M-P was given combined administration of midazolam and propofol(intravenous injection of 0.02-0.05 mg·kg-1 midazolam and 0.2-0.5 mg·kg-1 propofol for sedation induction and then continuously intravenous pump of 0.05-0.1 mg·kg-1 midazolam and 0.5-0.8 mg·kg·h-1 propofol).The sedation effect,blood gas indicators,hemodynamic indicators,extubation time,intensive care unit(ICU)stay time and treatment cost were compared among the three groups,and the adverse drug reactions during sedation therapy were recorded.Results There were 43 cases in group M,44 cases in group P,39 cases in group M-P.The drug onset times in groups M,P and M-P were(77.94±12.05),(18.18±5.20)and(21.25±9.36)s;the times to achieve satisfactory sedation effect were(42.57±11.41),(22.63±8.17)and(23.98±10.25)min;the recovery times after withdrawal were(59.30±14.86),(19.83±5.44)and(22.16±6.29)min;the extubation times were(1.61±0.20),(1.45±0.22)and(1.37±0.15)d;the ICU stay times were(2.17±0.29),(1.91±0.36)and(1.84±0.25)d;the treatment costs were(186.59±60.83),(922.97±164.34)and(375.03±71.16)thousand yuan;and the total incidence rates of adverse drug reactions were 34.88％,4.55％and 7.69％respectively,all with significant difference(all P＜0.05).There were no statistically significant differences in mean arterial pressure(MAP),heart rate(HR),oxygen saturation(SpO2),partial pressure of oxygen(PaO2),partial pressure of carbon dioxide(PaCO2)at T0,T1,T2,T3 and T4 among the three groups(all P＞0.05).Conclusion Combined administration of midazolam and propofol in elderly patients underwent mechanical ventilation after CPB cardiac surgery has a significant sedation effect,and it is conducive to reducing the dosages of sedative drugs,and it has small impact on blood gas indicators and hemodynamic indicators of patients.Compared with midazolam alone,it is more beneficial to shortening the extubation time and ICU stay and reducing the total incidence rate of adverse drug reactions,and compared with propofol alone,it is more beneficial to reducing treatment cost,and is a more ideal sedation administration model.

Objective To investigate the effects of palmatine on migration,invasion and epithelial mesenchymal transformation(EMT)in human oral cancer KB cells.Methods KB cells were divided into control group and palmatine-L,-M,-H groups,cultured with 0,4,8 and 16 μmol·L-1 palmatine.After incubation for 48 h,scratch assay was used to detect migration;Traswell assay was used to detect invasion;matrix metalloproteinase 2(MMP-2),MMP-9 and fibronectin(FN)contents were detected by enzyme-linked immunosorbent assay;the expression of Vimentin,N-cadherin and E-cadherin mRNA were detected by real-time quantitative polymerase chain reaction;the expression of Vimentin,N-cadherin,E-cadherin,Wnt3 and β-catenin protein were detected by Western blot.Results Cell mobility in control group and palmatine-L,-M,-H groups were(69.27±8.62)％,(52.94±4.49)％,(45.22±5.05)％and(37.63±4.88)％;the number of transmembrane cells were 197.33±20.26,125.33±12.01,97.00±9.17 and 62.67±7.51;the content of MMP-2 were(2.93±0.21),(1.49±0.13),(1.16±0.15)and(0.95±0.09)ng·mL-1;the content of MMP-9 were(3.51±0.36),(2.37±0.23),(2.06±0.35)and(1.72±0.16)ng·mL-1;the content of FN were(41.28±4.02),(24.03±3.17),(20.67±2.63)and(13.82±2.19)ng·mL-1;the above indexes in palmatine-L,-M,-H groups were compared with the control group,and the differences were statistically significant(P＜0.05,P＜0.01).The mRNA and protein expressions of Vimentin,N-cadherin and E-cadherin,and the expressions of Wnt3 and β-catenin protein in palmatine-L,-M,-H groups were statistically significant compared with those in control group(P＜0.05,P＜0.01).Conclusion Palmatine can inhibit the migration,invasion and EMT of human oral cancer KB cells,and its mechanism is related to the regulation of Wnt/β-catenin signaling pathway.

Objective To analyze the epidemiological characteristics and epidemic situation of children with Kashin-Beck disease (KBD) in China,and provide the basis for formulating prevention and control measures. Methods Fixed-point monitoring,moving-point monitoring,and full coverage of monitoring were promoted successively from 1990 to 2023. Some children (7-12 years old) underwent clinical and right-hand X-ray examinations every year. According to the KBD diagnosis criteria,clinical and X-ray assessments were used to confirm the diagnosis. Results In 1990,the national KBD detectable rate was 21.01％. X-ray detection decreased to below 10％ in 2003 and below 5％ in 2007. Between 2010 and 2018,the prevalence of KBD in children was less than 0.4％,which fluctuated at a low level,and has decreased to 0％ since 2019. Spatial epidemiological analysis indicated a spatial clustering of adult patients prevalence rate in the KBD areas. Conclusion The evaluation results of the elimination of KBD in China over the last 5 years showed that all villages in the monitored areas have reached the elimination standard. While the adult KBD patients still need for policy consideration and care.