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.

AIM To evaluate the quality consistency of Tongmai Granules,Tongmai Tablets,Tongmai Capsules and Tongmai Oral Liquid.METHODS The HPLC fingerprints were established,after which the contents of danshensu,protocatechuic aldehyde,3'-hydroxy puerarin,puerarin,puerarin apioside,daidzin,ferulic acid,salvianolic acid B and salvianolic acid A were determined,and cluster analysis and principal component analysis were adopted in the quality analysis from the perspective of daily intake.RESULTS There were 21 common peaks in the fingerprints for 39 batches of samples with the similarities of 0.765-0.997.Various batches of samples were clustered into 5 categories,2 principal components demonstrated the accumulative variance contribution rate of 83.53％ .The daily intakes of various constituents in different dosage forms exhibited obvious differences,especially for that of salvianolic acid B,which were low in tablets and capsules,and their heterogeneities existed among the same dosage forms.CONCLUSION This simple and accurate method can provide a reference for the quality evaluation of Tongmai preparations from different manufacturers.

Objective To investigate the characteristics of a novel FANCL mutation identified in a patient with premature ovarian insufficiency(POI)and to explore its potential functional impacts in vitro.Methods A novel FANCL heterozygous mutation c.1033G>A(p.Glu345Lys)was screened in a patient with POI using whole exome sequencing(WES),which was found to be inherited from a mother who had undergone early menopause.The authenticity of the mutation was identified by Sanger sequencing and the conserved nature of the mutation site was predicted by software.Overexpressing FANCL mutant and wildtype plasmids were constructed and transiently transfected into HEK293T cell lines,and the effect of the mutation was detected by qPCR,immunofluorescence and Western blot.Results The mutation site of FANCL was located within the Ring domain of FANCL,which was highly conserved across multiple species.The mutant showed no significant change in mRNA expression level,while the protein expression level was significantly down-regulated.In vitro cellular experiments further revealed that the mutation leads to decreased expression levels by reducing protein stability.Conclusion A FANCL c.1033G>A mutation was found and it may cause disease in the POI patient due to decreased protein stability.

Objective To screen and analyze key genes in rabbit corneal alkali burns based on transcriptomics se-quencing technology and bioinformatics techniques.Methods Thirty healthy male New Zealand rabbits were randomly di-vided into 2 groups(n=15 per group):The control group received no intervention,while the alkali burn group underwent corneal alkali burn modeling.Histological evaluation of corneal tissues was performed via hematoxylin-eosin(HE)stai-ning.Transcriptome sequencing was conducted for library construction and sequencing.Differentially expressed genes(DEGs)were identified using DESeq2,followed by Gene Ontology(GO)functional enrichment analysis and Kyoto Ency-clopedia of Genes and Genomes(KEGG)pathway analysis.A protein-protein interaction(PPI)network was constructed to screen hub genes,and RT-PCR was employed to validate mRNA expression levels of key genes.Results HE staining revealed orderly arranged corneal stromal layers and scattered stromal cells in the control group,whereas the alkali burn group exhibited stromal edema,thickened collagen fibers with loose/disorganized alignment,and increased fibroblast and inflammatory cell infiltration.Compared to the control group,1 827 significant DEGs were identified in the alkali burn group,including 1 495 upregulated and 332 downregulated genes.GO analysis showed biological processes such as immune response,plasma membrane,and identical protein binding.KEGG analysis indicated that DEGs were enriched in pathways related to cancer,lipid and atherosclerosis,and neuroactive ligand-receptor interaction.The PPI network screened 11 key genes:neutrophil cytosolic factor 1(NCF1),neutrophil cytosolic factor 2(NCF2),matrix metallopeptidase 2(MMP2),ma-trix metallopeptidase 9(MMP9),interleukin-1α(IL-1α),interleukin-1β(IL-1β),interleukin-6(IL-6),interleukin-8(CXCL8),cluster of differentiation 4(CD4),C-C motif ligand 2(CCL2)and tumor necrosis factor(TNF).RT-PCR valida-tion revealed that the mRNA expression levels of key genes in the corneal tissues of the alkali burn group were significantly higher than those in the control group(all P＜0.05),consistent with the transcriptomic sequencing results.Conclusion Based on the rabbit corneal alkali burn model,this study identified 11 key genes(NCF1,NCF2,MMP2,MMP9,IL-1α,IL-1β,IL-6,CXCL8,CD4,CCL2 and TNF)through transcriptomics and bioinformatics analysis.

Objective : To investigate the expression and interaction of activating transcription factor 3(ATF3) and smad family member 4(Smad4) in pterygium. Methods: In this study, two sets of data GSE51995 and GSE2513 in NCBI database were analyzed by bioinformatics methods to screen out the key difference-expressed gene ATF3 in pterygium when normal conjunctiva was used as the control. The differential genes identified by bioinformatics analysis were further detected by reverse transcription quantitative polymerase chain reaction(RT-qPCR). Finally, the literatures were searched and The Gene Transcription Regulation Database(GTRD) was used to predict whether there was a target gene Smad4 that might bind to the target gene. The expression of Smad4 in normal conjunctival and pterygium tissues was verified by RT-qPCR, and the interaction between the target protein ATF3 and Smad4 in the pterygium was investigated through Co-Immunoprecipitation(Co-IP). Results : The results of bioinformatics a- nalysis showed that compared with normal conjunctival tissue , there was significantly different expression of ATF3 gene in pterygium tissue (P < 0. 05) . RT-qPCR confirmed that ATF3 was less expressed in pterygium tissue than normal conjunctival tissue (P < 0. 001) . Genomic data from the GTRD database revealed that Smad4 contains two ATF3 binding motifs , suggesting functional interaction potential . Compared with normal conjunctiva , RT-qPCR re- vealed Smad4 downregulation in pterygium tissues (P < 0. 01) ; Co-IP demonstrated enhanced interaction between Smad4 and ATF3 in pterygium tissues following immunoprecipitation with anti-ATF3 antibodies (P < 0. 05) . Conclusion ATF3 interacts with Smad4 in pterygium , and the low expression of both in pterygium tissues and their in- teraction may be associated with the pathogenesis of pterygium .

Metachromatic leukodystrophy (MLD) is an inherited disease caused by a deficiency of the enzyme arylsulfatase A (ARSA). Lentivirus-modified autologous hematopoietic stem cell gene therapy (HSCGT) has recently been approved for clinical use in pre and early symptomatic children with MLD to increase ARSA activity. Unfortunately, this advanced therapy is not available for most patients with MLD who have progressed to more advanced symptomatic stages at diagnosis. Patients with late-onset juvenile MLD typically present with a slower neurological progression of symptoms and represent a significant burden to the economy and healthcare system, whereas those with early onset infantile MLD die within a few years of symptom onset. We conducted a pilot study to determine the safety and benefit of HSCGT in patients with postsymptomatic juvenile MLD and report preliminary results. The safety profile of HSCGT was favorable in this long-term follow-up over 9 years. The most common adverse events (AEs) within 2 months of HSCGT were related to busulfan conditioning, and all AEs resolved. No HSCGT-related AEs and no evidence of distorted hematopoietic differentiation during long-term follow-up for up to 9.6 years. Importantly, to date, patients have maintained remarkably improved ARSA activity with a stable disease state, including increased Functional Independence Measure (FIM) score and decreased magnetic resonance imaging (MRI) lesion score. This long-term follow-up pilot study suggests that HSCGT is safe and provides clinical benefit to patients with postsymptomatic juvenile MLD.
Humans ; Leukodystrophy, Metachromatic/genetics* ; Pilot Projects ; Genetic Therapy/methods* ; Hematopoietic Stem Cell Transplantation ; Male ; Follow-Up Studies ; Female ; Lentivirus/genetics* ; Child ; Child, Preschool ; Hematopoietic Stem Cells/metabolism* ; Cerebroside-Sulfatase/metabolism* ; Adolescent

Osteoporosis(OP) is a senile bone disease characterized by an imbalance between bone remodeling and bone formation. Targeting pathogenesis of kidney deficiency, spleen deficiency, and blood stasis, Bushen Jianpi Huoxue Decoction has a significant effect on the treatment of OP by tonifying kidney, invigorating spleen, and activating blood circulation. MicroRNA(miRNA) and the anti-apoptotic protein B-cell lymphoma-2-like protein 1(BCL2L1) are closely related to bone cell metabolism. Therefore, in this study, the binding of miR-140-5p to BCL2L1 was detected by dual luciferase assay and polymerase chain reaction(PCR). After silencing or overexpressing miR-140-5p, the apoptosis, autophagy, and osteogenic function of human fetal osteoblast cell line 1.19(HFOB1.19) were observed by flow cytometry and Western blot. Bushen Jianpi Huoxue Decoction-containing serum was prepared by intragastric administration of Bushen Jianpi Huoxue Decoction in rats. Different concentrations of Bushen Jianpi Huoxue Decoction-containing serum were used to treat HFOB1.19 with or without miR-140-5p mimic. The expression of osteogenic proteins in each group was observed, and the role of miR-140-5p/BCL2L1 in apoptosis and autophagy of HFOB1.19 was studied, along with the effect of Bushen Jianpi Huoxue Decoction on these processes. As indicated by the dual luciferase assay, miR-140-5p bound to BCL2L1. Flow cytometry and Western blot showed that miR-140-5p promoted apoptosis and inhibited autophagy in HFOB1.19. After intervention with high, medium, and low doses of Bushen Jianpi Huoxue Decoction-medicated serum, compared with the miR-140-5p NC group, the expression of osteocalcin(OCN), osteopontin(OPN), Runt-related transcription factor 2(RUNX2), and transforming growth factor beta 1(TGF-β1) decreased in the miR-140-5p mimic group, while the expression of bone morphogenetic protein 2(BMP2) showed no significant difference under high-dose intervention. Therefore, miR-140-5p/BCL2L1 can promote apoptosis and inhibit autophagy in HFOB1.19. Bushen Jianpi Huoxue Decoction can affect the osteogenic effect of miR-140-5p through BMP2.
MicroRNAs/metabolism* ; Autophagy/drug effects* ; Apoptosis/drug effects* ; Humans ; Drugs, Chinese Herbal/administration & dosage* ; Animals ; Cell Line ; bcl-X Protein/metabolism* ; Osteoblasts/metabolism* ; Rats ; Osteoporosis/physiopathology* ; Male ; Rats, Sprague-Dawley ; Osteogenesis/drug effects*

Selenoproteins, as the active form of selenium, play an important role in various physiological and pathological processes, such as anti-oxidation, anti-tumor, immune response, metabolic regulation, reproduction and aging. Although the expression level of selenoproteins in adipose tissue is significantly influenced by dietary selenium intake, it is closely related to the homeostasis of adipose tissue. In this review, we summarized the role of selenoproteins in the physiological function of adipose tissue and the pathogenesis of obesity in recent years, in order to provide a rationale for developing potential therapeutic agents for the treatment of obesity and related metabolic diseases.
Selenoproteins/metabolism* ; Adipose Tissue/physiology* ; Obesity/metabolism* ; Humans ; Animals ; Selenium

Aim To investigate the protective effects and potential mechanisms of Radix Angelica sinensis and Radix Hedysari ultrafiltrate(RAS-RH)on X-ray-induced cellular damage in Raw264.7 macrophages.Methods An integrated approach combining network pharmacology,molecular docking,and bioinformatics a-nalysis was employed to predict therapeutic targets and signaling pathways of RAS-RH in coronary heart dis-ease(CHD).Subsequent in vitro validation was per-formed using an X-ray(6 Gy)-induced macrophage in-jury model with four experimental groups:control,radi-ation-only model,and three RAS-RH-treated groups at varying concentrations.Cell viability was assessed by CCK-8 assay,apoptosis by flow cytometry with Annexin V-FITC/PI staining,mitochondrial membrane potential by JC-1 fluorescence,and inflammatory cytokine levels(IL-1 β,IL-6,IL-18,TNF-α)by ELISA.Molecular mechanisms were investigated through Western blot and qRT-PCR analyses of TLR4/NLRP3/Caspase-1 sig-naling pathway components and Bcl-2 family proteins.Results Network pharmacology revealed RAS-RH's multi-target action on apoptosis and inflammation-relat-ed pathways,particularly NF-κB and Bcl-2 signaling.Molecular docking identified strong binding affinities between RAS-RH components and TLR4/NLRP3 pro-teins.In vitro studies demonstrated that RAS-RH treat-ment significantly improved cell viability(P＜0.01),reduced apoptosis(P＜0.01),restored mitochondrial membrane potential(P＜0.05),and attenuated radia-tion-induced ultrastructural damage including mem-brane disruption and cytoplasmic vacuolization.ELISA showed marked suppression of pro-inflammatory cyto-kines(P＜0.01).Transmission electron microscopy(TEM)analysis revealed that RSA-RH ameliorated pyroptosis-associated ultrastructural alterations,inclu-ding plasma membrane disruption and cytoplasmic vac-uolization.Protein and gene expression analyses con-firmed downregulation of TLR4/NLRP3/Caspase-1 pathway and modulation of Bcl-2/Bax ratio.Conclu-sion RAS-RH exerts radioprotective effects through dual regulation of pyroptosis and apoptosis pathways,suggesting its potential as an adjuvant therapy for radia-tion-induced cardiovascular complications in CHD pa-tients.

Postoperative infection of internal fixation of closed fractures the lower limbs in adults represents a devastating complication, characterized by diagnostic challenges, prolonged treatment duration and high disability rates. Current management of these infections faces multiple challenges, such as difficulties in early accurate diagnosis, and various controversies about the treatment plan, leading to poor overall diagnosis and treatment results. To address these issues, based on evidence-based medicine and principles with emphasis on scientific rigor, clinical applicability and innovation, the Trauma Branch of the Chinese Medical Association, Orthopedic Branch of the Chinese Medical Doctor Association, Orthopedics Branch of the Chinese Medical Association, and Trauma Orthopedics and Polytrauma Group of the Resuscitation and Emergency Committee of the Chinese Medical Doctor Association have collaboratively organized a panel of relevant experts to develop the Guideline for diagnosis and treatment of infection after internal fixation of closed lower limb fractures in adults ( version 2025). The guideline proposed 10 recommendations, aiming to provide a foundation for standardized diagnosis and treatment of postoperative infection in adults with closed lower limb fractures.