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.

Triple-negative breast cancer (TNBC) represents a distinctive subtype, characterized by the absence of estrogen receptors, progesterone receptors, and human epidermal growth factor receptor 2 (HER2). Due to its high inter-tumor and intra-tumor heterogeneity, TNBC poses significant chanllenges for personalized diagnosis and treatment. The advant of clustered regular interspaced short palindromic repeats (CRISPR) technology has profoundly enhanced our understanding of the structure and function of the TNBC genome, providing a powerful tool for investigating the occurrence and development of diseases. This review focuses on the application of CRISPR/Cas technology in the personalized diagnosis and treatment of TNBC. We begin by discussing the unique attributes of TNBC and the limitations of current diagnostic and treatment approaches: conventional diagnostic methods provide limited insights into TNBC, while traditional chemotherapy drugs are often associated with low efficacy and severe side effects. The CRISPR/Cas system, which activates Cas enzymes through complementary guide RNAs (gRNAs) to selectively degrade specific nucleic acids, has emerged as a robust tool for TNBC research. This technology enables precise gene editing, allowing for a deeper understanding of TNBC heterogeneity by marking and tracking diverse cell clones. Additionally, CRISPR facilitates high-throughput screening to promptly identify genes involved in TNBC growth, metastasis, and drug resistance, thus revealing new therapeutic targets and strategies. In TNBC diagnostics, CRISPR/Cas was applied to develop molecular diagnostic systems based on Cas9, Cas12, and Cas13, each employing distinct detection principles. These systems can sensitively and specifically detect a variety of TNBC biomarkers, including cell-specific DNA/RNA and circulating tumor DNA (ctDNA). In the realm of precision therapy, CRISPR/Cas has been utilized to identify key genes implicated in TNBC progression and treatment resistance. CRISPR-based screening has uncovered potential therapeutic targets, while its gene-editing capabilities have facilitated the development of combination therapies with traditional chemotherapy drugs, enhancing their efficacy. Despite its promise, the clinical translation of CRISPR/Cas technology remains in its early stages. Several clinical trials are underway to assess its safety and efficacy in the treatment of various genetic diseases and cancers. Challenges such as off-target effects, editing efficiency, and delivery methods remain to be addressed. The integration of CRISPR/Cas with other technologies, such as 3D cell culture systems, human induced pluripotent stem cells (hiPSCs), and artificial intelligence (AI), is expected to further advance precision medicine for TNBC. These technological convergences can offer deeper insights into disease mechanisms and facilitate the development of personalized treatment strategies. In conclusion, the CRISPR/Cas system holds immense potential in the precise diagnosis and treatment of TNBC. As the technology progresses and becomes more costs-effective, its clinical relevance will grow, and the translation of CRISPR/Cas system data into clinical applications will pave the way for optimal diagnosis and treatment strategies for TNBC patients. However, technical hurdles and ethical considerations require ongoing research and regulation to ensure safety and efficacy.

A growing body of research points out that gut microbiota plays a key role in tumor immunotherapy. By optimizing the composition of intestinal microbiota, it is possible to effectively improve immunotherapy resistance and enhance its therapeutic effect. This article comprehensively analyzes the mechanism of intestinal microbiota influencing tumor immunotherapy resistance, expounds the current strategies for targeted regulation of intestinal microbiota, such as traditional Chinese medicine and plant components, fecal microbiota transplantation, probiotics, prebiotics and dietary therapy, and explores the potential mechanisms of these strategies to improve patients' resistance to tumor immunotherapy. At the same time, the article also briefly discusses the prospects and challenges of targeting intestinal microbiota to improve tumor immunotherapy resistance, which provides a reference for related research to help the strategy research of reversing tumor immunotherapy resistance.

The auxin/indole-3-acetic acid (Aux/IAA) gene family is an important regulator for plant growth hormone signaling, involved in plant growth, development, as well as response to environmental stresses. In the present study, we identified SmIAA7 which is potentially associated with Salvia miltiorrhiza leaf development through comparatively analyzed the transcriptome data from different pinnate leaves. SmIAA7 was successfully isolated from S. miltiorrhiza using the specific primers. Then subsequent bioinformatic analysis, prokaryotic expression and purification, subcellular localization, and induction expression analysis under auxin and abiotic stress were performed. The full-length of SmIAA7 contained an ORF of 684 bp encoding a protein of 227 amino acid with a molecular weight of 25.3 kD. Conserved domain analysis showed that SmIAA7 contains the conserved Aux_IAA domain (pfam02309). Sequence analysis and phylogenetic tree analysis results indicated SmIAA7 was phylogenetically close to IAA7 and IAA14 from other plants, suggesting SmIAA7 involved in plant growth and development as well as response to environmental stresses. The prokaryotic expression vector pET28a-SmIAA7 was constructed and SmIAA7 recombinant protein was successfully expressed in E. coli Rosetta (DE3) strain. Subcellular localization experiment demonstrated that SmIAA7 localized in the nucleus of plant cells. Real-time fluorescence quantitative PCR results showed that the expression level of SmIAA7 was upregulated in response to auxin. Drought, low temperature, and salt stress significantly increased the transcript level of SmIAA7 gene. This study lays a foundation for further elucidating the role of SmIAA7 in leaf development, signal transduction, and stress defense in S. miltiorrhiza.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of national bloodstream infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:During the study period，9 035 strains of Gram-negative bacteria were collected from 51 hospitals，of which 7 895（87.4%）were Enterobacteriaceae and 1 140（12.6%）were non-fermenting bacteria. The top 5 bacterial species were Escherichia coli（ n=4 510，49.9%）， Klebsiella pneumoniae（ n=2 340，25.9%）， Pseudomonas aeruginosa（ n=534，5.9%）， Acinetobacter baumannii complex（ n=405，4.5%）and Enterobacter cloacae（ n=327，3.6%）. The ESBLs-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus spp. were 47.1%（2 095/4 452），21.0%（427/2 033）and 41.1%（58/141），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（58/4 510）and 13.1%（307/2 340）；62.1%（36/58）and 9.8%（30/307）of CREC and CRKP were resistant to ceftazidime/avibactam combination，respectively. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 59.5%（241/405），while less than 5% of Acinetobacter baumannii complex was resistant to tigecycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 18.4%（98/534）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of main Gram-negative bacteria resistance among different regions，with statistically significant differences in the prevalence of CRKP and CRPA（ χ2=20.489 and 20.252， P<0.001）. The prevalence of CREC，CRKP，CRPA，CRAB，ESBLs-producing Escherichia coli and Klebsiella pneumoniae were higher in provinicial hospitals than those in municipal hospitals（ χ2=11.953，81.183，10.404，5.915，12.415 and 6.459， P<0.01 or <0.05），while the prevalence of CRPA was higher in economically developed regions（per capita GDP ≥ 92 059 Yuan）than that in economically less-developed regions（per capita GDP <92 059 Yuan）（ χ2=6.240， P=0.012）. Conclusions:The proportion of Gram-negative bacteria in bloodstream infections shows an increasing trend，and Escherichia coli is ranked in the top，while the trend of CRKP decreases continuously with time. Decreasing trends are noted in ESBLs-producing Escherichia coli and Klebsiella pneumoniae. Low prevalence of carbapenem resistance in Escherichia coli and high prevalence in CRAB complex have been observed. The composition ratio and antibacterial spectrum of bloodstream infections in different regions of China are slightly different，and the proportion of main drug resistant bacteria in provincial hospitals is higher than those in municipal hospitals.

In recent years, the development of host-acting antibacterial compounds has gradually become a hotspot in the field of anti-infection. Through research on the interaction mechanism between hosts and pathogenic bacteria, it has been found that the immune system is one of the key targets of host-acting antibacterial compounds. There is a communication system called the quorum sensing system in microorganisms, which mainly adjusts the structure of multi-microbial community and coordinates the group behavior. When the quorum sensing molecules secreted by microorganisms reach a threshold concentration, the quorum sensing system is activated and the overall gene expression of the microorganism is changed. In addition to regulating the density of microorganisms, quorum sensing molecules can also act as a link between pathogenic microorganisms and hosts, entering the host immune system and playing a role in affecting the morphological structure of immune cells, secreting cytokines, and inducing apoptosis, leading to host immune injury and causing host immune dysfunction.The key mechanism of 3-oxo-C12-HSL and other acyl-homoserine lactone (AHL) molecules in the innate immune system has been extensively studied. The lipid solubility allows AHLs to pass through the plasma membrane of host immune cells easily and induce dissolution of lipid domains. Then, it acts through signaling pathways such as p38MAPK and JAK-STAT, further influencing the immune cell’s defense response to bacteria and potentially leading to cell apoptosis. Additionally, the human lactonase paraoxonase 2, which can degrade3-oxo-C12-HSL, has been found in macrophage. It acts as an immune regulator that promotes macrophage phagocytosis of pathogens and is hypothesized to have the ability to reduce bacterial resistance. The mechanism of quorum sensing molecules in the adaptive immune system is less studied, the current results suggest that 3-oxo-C12-HSL is closely related to the mitochondrial pathway in host immune cells. For example, 3-oxo-C12-HSL induces apoptosis of Jurkat cells by inhibiting the expression of three mitochondrial electron transport chain proteins; it can also trigger mitochondrial dysfunction and induce mast cell apoptosis through Ca²⁺ signaling.Among the quorum sensing molecules, the AHLs have the greatest impact on plant immune system. The different effects on plant resistance depends on the chain lengths of acyl groups in bacterial-produced AHLs. Short-chain AHLs (C4-HSL and C8-HSL) induce plant resistance to pathogenic bacteria mainly through the auxin pathway and jasmonic acid pathway. Long-chain AHL (3-oxo-C14-HSL) is commonly used in hosts against fungal pathogens by inducing stomata defense responses, and the reaction process is related to salicylic acid. Diffusible signal factor molecules also interfere with the stomatal immunity caused by pathogens. It may act through the formin nanoclustering-mediated actin assembly and MPK3 pathway to inhibit the innate immunity of Arabidopsis. In summary, AHLs induced different plant pathways and affects the plant-bacteria interactions to trigger plant immunity. As a quorum sensing molecule of fungi, farnesol has similar effects on host immunity as AHLs, such as stimulating cytokine secretion and activating an inflammatory response. It also plays a unique role on dendritic cell differentiation and maturation. In addition, studies have found that farnesol has a protective effect on autoimmune encephalomyelitis, which may be related to its effect on the composition of intestinal microorganisms of the host.Therefore, targeting the host immune system and quorum sensing molecules to develop antibacterial compounds can effectively inhibit the invasion of pathogens and subserve the host to resist the influence of pathogenic bacteria. This article will review the mechanism of host immune responses triggered by important quorum sensing molecules, aiming to explore the targets of host-acting antibacterial compounds and provide new directions for the prevention or treatment of causative infectious sources and the development of related drugs.

Objective This study aimed to evaluate whether the onset of the plateau phase of slow hepatitis B surface antigen decline in patients with chronic hepatitis B treated with intermittent interferon therapy is related to the frequency of dendritic cell subsets and expression of the costimulatory molecules CD40,CD80,CD83,and CD86. Method This was a cross-sectional study in which patients were divided into a natural history group(namely NH group),a long-term oral nucleoside analogs treatment group(namely NA group),and a plateau-arriving group(namely P group).The percentage of plasmacytoid dendritic cell and myeloid dendritic cell subsets in peripheral blood lymphocytes and monocytes and the mean fluorescence intensity of their surface costimulatory molecules were detected using a flow cytometer. Results In total,143 patients were enrolled(NH group,n = 49;NA group,n = 47;P group,n = 47).The results demonstrated that CD141/CD1c double negative myeloid dendritic cell(DNmDC)/lymphocytes and monocytes(%)in P group(0.041[0.024,0.069])was significantly lower than that in NH group(0.270[0.135,0.407])and NA group(0.273[0.150,0.443]),and CD86 mean fluorescence intensity of DNmDCs in P group(1832.0[1484.0,2793.0])was significantly lower than that in NH group(4316.0[2958.0,5169.0])and NA group(3299.0[2534.0,4371.0]),Adjusted P all<0.001. Conclusion Reduced DNmDCs and impaired maturation may be associated with the onset of the plateau phase during intermittent interferon therapy in patients with chronic hepatitis B.

Objective To explore characteristics of clinical parameters and cytokines in patients with drug-induced liver injury(DILI)caused by different drugs and their correlation with clinical indicators. Method The study was conducted on patients who were up to Review of Uncertainties in Confidence Assessment for Medical Tests(RUCAM)scoring criteria and clinically diagnosed with DILI.Based on Chinese herbal medicine,cardiovascular drugs,non-steroidal anti-inflammatory drugs(NSAIDs),anti-infective drugs,and other drugs,patients were divided into five groups.Cytokines were measured by Luminex technology.Baseline characteristics of clinical biochemical indicators and cytokines in DILI patients and their correlation were analyzed. Results 73 patients were enrolled.Age among five groups was statistically different(P=0.032).Alanine aminotransferase(ALT)(P=0.033)and aspartate aminotransferase(AST)(P=0.007)in NSAIDs group were higher than those in chinese herbal medicine group.Interleukin-6(IL-6)and tumor necrosis factor alpha(TNF-α)in patients with Chinese herbal medicine(IL-6:P<0.001;TNF-α:P<0.001)and cardiovascular medicine(IL-6:P=0.020;TNF-α:P=0.001)were lower than those in NSAIDs group.There was a positive correlation between ALT(r=0.697,P=0.025),AST(r=0.721,P=0.019),and IL-6 in NSAIDs group. Conclusion Older age may be more prone to DILI.Patients with NSAIDs have more severe liver damage in early stages of DILI,TNF-α and IL-6 may partake the inflammatory process of DILI.

Objective To systematically evaluate the clinical efficacy and safety of therapy of tonifying kidney and promoting blood circulation(shortened as Bushen Huoxue method)combined with cyclosporine plus androgen for the treatment of aplastic anemia(AA).Methods Randomized controlled trials(RCTs)of Bushen Huoxue method combined with cyclosporine plus androgen(trial group)versus cyclosporine plus androgen alone(control group)for the treatment of AA were retrieved from the major domestic and oversea databases,and then high-quality RCTs that met the inclusion criteria were screened.RevMan 5.3 software was used for meta-analysis.Results A total of 6 RCTs involving 365 patients were included.The results of meta-analysis showed that the total effective rate of AA in the trial group was significantly superior to that of the control group[OR=4.43,95%CI(2.50,7.84);P＜0.000 01].The trial group was superior to the control group on improving the peripheral blood indicators such as hemoglobin(HGB)level[MD=14.85,95%CI(10.66,19.05);P＜0.000 01],white blood cell(WBC)level[MD=0.61,95%CI(0.21,1.01);P=0.003],platelet(PLT)level[MD=16.51,95%CI(9.28,23.75);P＜0.000 01],and did not increase the incidence of adverse reactions such as hirsutism[OR=0.24,95%CI(0.10,0.61);P=0.003],acne[OR=0.30,95%CI(0.13,0.66);P=0.003],and abnormal liver function[OR=0.28,95%CI(0.09,0.83);P=0.02].Conclusion Bushen Huoxue method combined with cyclosporine plus androgen for the treatment of AA is superior to the use of cyclosporine plus androgen alone on enhancing clinical efficacy and improving the peripheral blood indicators,and has certain advantages in reducing the incidence of adverse reactions.

Objective To investigate the effect of MALAT1 expressions on cell proliferation and apoptosis in astrocytes by regulating mitogen-activated protein kinase(MAPK)/extracellular signal-regulated kinase(ERK1,2)pathway.Methods The MALAT1 gene was knocked down and over-expressed in C8-D1A cells by lentiviral and plasmid vectors,respectively.The expressions of MALAT1,cell proliferation-related markers(Ki67,MCM2,PCNA)and apoptosis-related proteins(Caspase-3,Bax,Bcl-2)were detected by quantitative real-time polymerase chain reaction(qPCR).CCK-8 assay and flow cytometry were used for cell proliferation and apoptosis in C8-D1A cells.Immunofluorescence was adopted to detect the protein expressions of Caspase-3 and Ki67.Western blotting was used to detect the protein expressions of Caspase-3,Bax,Bcl-2,ERK1/2,p-ERK1/2,p38MAPK and p-p38MAPK.Results Compared with the control group,over-expressed MALAT1 inhibited cell proliferation and induced cell apoptosis in C8-D1A cells while the knockdown of MALAT1 significantly enhanced cell proliferation and anti-apoptotic ability in C8-D1A cells.The proportion of C8-D1A cells in G0/G1-phase and G2/M-phase was higher than in the control group as evidenced by flow cytometry,but was lower in S-phase.Meanwhile,data showed that Caspase-3 was increased while p-ERK1/2 was decreased in terms of protein levels.The mRNA expressions of Ki67 and PCNA were decreased.After knockdown of MALAT1,the proportion of C8-D1A cells in S-phase was higher,but was lower in G2/M-phase.The protein expressions of Caspase-3 and Bax decreased while those of p-ERK1/2 and p-p38MAPK increased.The mRNA expressions of Ki67,MCM2 and PCNA were increased.The differences were all statistically significant(P＜0.05).Conclusion MALAT1 promotes astrocyte apoptosis and inhibits proliferation by regulating the MAPK/ERK1,2 signaling pathway.