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.

BACKGROUND: Preclinical studies have indicated that Angong Niuhuang Pills (ANP) reduce cerebral infarct and edema volumes. This study aimed to investigate whether ANP safely reduces cerebral infarct and edema volumes in patients with moderate to severe acute ischemic stroke. METHODS: This randomized, double-blind, placebo-controlled pilot trial included patients with acute ischemic stroke with National Institutes of Health Stroke Scale (NIHSS) scores ranging from 10 to 20 in 17 centers in China between April 2021 and July 2022. Patients were allocated within 36 h after onset via block randomization to receive ANP or placebo (3 g/day for 5 days). The primary outcomes were changes in cerebral infarct and edema volumes after 14 days of treatment. The primary safety outcome was severe adverse events (SAEs) for 90 days. RESULTS: There were 57 and 60 patients finally included in the ANP and placebo groups, respectively for modified intention-to-treat analysis. The median age was 66.0 years, and the median NIHSS score at baseline was 12.0. The changes in cerebral infarct volume at day 14 were 0.3 mL and 0.4 mL in the ANP and placebo groups, respectively (median difference: -7.1 mL; interquartile range [IQR]: -18.3 to 2.3 mL, P = 0.30). The changes in cerebral edema volume of the ANP and placebo groups on day 14 were 11.4 mL and 4.0 mL, respectively ( median difference: 3.0 mL, IQR: -1.3 to 9.9 mL, P = 0.15). The rates of SAE within 90 days were similar in the ANP (3/57, 5%) and placebo (7/60, 12%) groups ( P = 0.36). Changes in serum mercury and arsenic concentrations were comparable. In patients with large artery atherosclerosis, ANP reduced the cerebral infarct volume at 14 days (median difference: -12.3 mL; IQR: -27.7 to -0.3 mL, P = 0.03). CONCLUSIONS: ANP showed a similar safety profile to placebo and non-significant tendency to reduce cerebral infarct volume in patients with moderate-to-severe stroke. Further studies are warranted to assess the efficacy of ANP in reducing cerebral infarcts and improving clinical prognosis. TRAIL REGISTRATION Clinicaltrials.gov , No. NCT04475328.
Aged ; Female ; Humans ; Male ; Middle Aged ; Double-Blind Method ; Drugs, Chinese Herbal/adverse effects* ; Ischemic Stroke/drug therapy* ; Pilot Projects ; Stroke/drug therapy* ; Treatment Outcome

The phase changes and quantity-quality transfer of 17 batches of Ostreae Concha(Ostrea rivularis) during the raw material-calcined decoction pieces-standard decoction process were analyzed. The content of calcium carbonate(CaCO_3), the main component, was determined by chemical titration, and the extract yield and transfer rate were calculated. The CaCO_3 content in the raw material, calcined decoction pieces, and standard decoction was 94.39%-98.80%, 95.03%-99.22%, and 84.58%-90.47%, respectively. The process of raw material to calcined decoction pieces showed the yield range of 96.85% to 98.55% and the CaCO_3 transfer rate range of 96.92% to 99.27%. The process of calcined decoction pieces to standard decoction showed the extract yield range of 2.86% to 5.48% and the CaCO_3 transfer rate range of 2.59% to 5.13%. The results of X-ray fluorescence(XRF) assay showed that the raw material, calcined decoction pieces, and standard decoction mainly contained Ca, Na, Mg, Si, Br, Cl, Al, Fe, Cr, Mn, and K. The chemometric results showed an increase in the relative content of Cr, Fe, and Si from raw material to calcined decoction pieces and an increase in the relative content of Mg, Al, Br, K, Cl, and Na from calcined decoction pieces to standard decoction. X-ray diffraction(XRD) was employed to establish XRD characteristic patterns of the raw material, calcined decoction pieces, and standard decoction. The XRD results showed that the main phase of all three was calcite, and no transformation of crystalline form or generation of new phase was observed. Fourier transform infrared spectroscopy(FTIR) was employed to establish the FTIR characteristic spectra of the raw material, calcined decoction pieces, and standard decoction. The FTIR results showed that the raw material had internal vibrations of O-H, C-H, C=O, C-O, and CO■ groups. Due to the loss of organic matter components after calcination, no information about the vibrations of C-H, C=O, and C-O groups was observed in the spectra of calcined decoction pieces and standard decoction. In summary, this study elucidated the quantity-quality transfer and phase changes in the raw material-calcined decoction pieces-standard decoction process by determining the CaCO_3 content, calculating the extract yield and transfer rate, and comparing the element changes, FTIR characteristic spectra, and XRD characteristic pattern. The results were reasonable and reliable, laying a foundation for the subsequent process research and quality control of the formula granules of calcined Ostreae Concha(O. rivularis Gould), and providing ideas and methods for the quality control of the whole process of raw material-decoction pieces-standard decoction-formula granules of Ostreae Concha and other testacean traditional Chinese medicine.
Drugs, Chinese Herbal/isolation & purification* ; Calcium Carbonate/analysis* ; Quality Control

Guided by the concept of quality by design(QbD), this study optimizes the calcination and quenching process of calcined Magnetitum and establishes the XRD characteristic spectra of calcined Magnetitum, providing a scientific basis for the formulation of quality standards. Based on the processing methods and quality requirements of Magnetitum in the Chinese Pharmacopoeia, the critical process parameters(CPPs) identified were calcination temperature, calcination time, particle size, laying thickness, and the number of vinegar quenching cycles. The critical quality attributes(CQAs) included Fe mass fraction, Fe~(2+) dissolution, and surface color. The weight coefficients were determined by combining Analytic Hierarchy Process(AHP) and the criteria importance though intercrieria correlation(CRITIC) method, and the calcination process was optimized using orthogonal experimentation. Surface color was selected as a CQA, and based on the principle of color value, the surface color of calcined Magnetitum was objectively quantified. The vinegar quenching process was then optimized to determine the best processing conditions. X-ray diffraction(XRD) was used to establish the characteristic spectra of calcined Magnetitum, and methods such as similarity evaluation, cluster analysis, and orthogonal partial least squares-discriminant analysis(OPLS-DA) were used to evaluate the quality of the spectra. The optimized calcined Magnetitum preparation process was found to be calcination at 750 ℃ for 1 h, with a laying thickness of 4 cm, a particle size of 0.4-0.8 cm, and one vinegar quenching cycle(Magnetitum-vinegar ratio 10∶3), which was stable and feasible. The XRD characteristic spectra analysis method, featuring 9 common peaks as fingerprint information, was established. The average correlation coefficient ranged from 0.839 5-0.988 1, and the average angle cosine ranged from 0.914 4 to 0.995 6, indicating good similarity. Cluster analysis results showed that Magnetitum and calcined Magnetitum could be grouped together, with similar compositions. OPLS-DA discriminant analysis identified three key characteristic peaks, with Fe_2O_3 being the distinguishing component between the two. The final optimized processing method is stable and feasible, and the XRD characteristic spectra of calcined Magnetitum was initially established, providing a reference for subsequent quality control and the formulation of quality standards for calcined Magnetitum.
X-Ray Diffraction/methods* ; Drugs, Chinese Herbal/chemistry* ; Quality Control ; Particle Size

Protein tyrosine phosphatase nonreceptor type 2 (PTPN2) is a promising target for sensitizing solid tumors to immune checkpoint blockades. However, the highly polar active sites of PTPN2 hinder drug discovery efforts. Leveraging small interfering RNA (siRNA) technology, we developed a novel glutathione-responsive nano-platform HPssPT (HA/PEIss@siPtpn2) to silence PTPN2 and enhance immunotherapy efficacy in hepatocellular carcinoma (HCC). HPssPT showed potent transfection and favorable safety profiles. PTPN2 deficiency induced by HPssPT amplified the interferon γ signaling in HCC cells by increasing the phosphorylation of Janus-activated kinase 1 and signal transducer and activator of transcription 1, resulting in enhanced antigen presentation and T cell activation. The nano-platform was also able to promote the M1-like polarization of macrophages in vitro. The unique tropism of HPssPT towards tumor-associated macrophages, facilitated by hyaluronic acid coating and CD44 receptor targeting, allowed for simultaneous reprogramming of both tumor cells and tumor-associated macrophages, thereby synergistically reshaping tumor microenvironment to an immunostimulatory state. In HCC, colorectal cancer, and melanoma animal models, HPssPT monotherapy provoked robust antitumor immunity, thereby sensitizing tumors to PD-1 blockade, which provided new inspiration for siRNA-based drug discovery and tumor immunotherapy.

The continuous emergence of SARS-CoV-2 variants as well as other potential future coronavirus has challenged the effectiveness of current COVID-19 vaccines. Therefore, there remains a need for alternative antivirals that target processes less susceptible to mutations, such as the formation of six-helix bundle (6-HB) during the viral fusion step of host cell entry. In this study, a novel high-throughput screening (HTS) assay employing a yeast-two-hybrid (Y2H) system was established to identify inhibitors of HR1/HR2 interaction. The compound IMB-9C, which achieved single-digit micromolar inhibition of SARS-CoV-2 and its Omicron variants with low cytotoxicity, was selected. IMB-9C effectively blocks the HR1/HR2 interaction in vitro and inhibits SARS-CoV-2-S-mediated cell-cell fusion. It binds to both HR1 and HR2 through non-covalent interaction and influences the secondary structure of HR1/HR2 complex. In addition, virtual docking and site-mutagenesis results suggest that amino acid residues A930, I931, K933, T941, and L945 are critical for IMB-9C binding to HR1. Collectively, in this study, we have developed a novel screening method for HR1/HR2 interaction inhibitors and identified IMB-9C as a potential antiviral small molecule against COVID-19 and its variants.

Objective:To prepare the chitin/hyaluronic acid/collagen hydrogel loaded with mouse adipose-derived stem cells and to explore its effects on wound healing of full-thickness skin defects in rats.Methods:The research was an experimental research. Chitin nanofibers were prepared by acid hydrolysis and alkaline extraction method, and then mixed with hyaluronic acid and collagen to prepare chitin/hyaluronic acid/collagen hydrogels (hereinafter referred to as hydrogels). Besides, the hydrogels loaded with mouse adipose-derived stem cells were prepared. Thirty male 12-week-old guinea pigs were divided into negative control group, positive control group, and hydrogel group according to the random number table, with 10 guinea pigs in each group. Ethanol, 4-aminobenzoic acid ethyl ester, or the aforementioned prepared hydrogels without cells were topically applied on both sides of back of guinea pigs respectively for induced contact and stimulated contact, and skin edema and erythema formation were observed at 24 and 48 h after stimulated contact. Adipose-derived stem cells from mice were divided into normal control group cultured routinely and hydrogel group cultured with the aforementioned prepared hydrogels without cells. After 3 d of culture, protein expressions of platelet-derived growth factor-D (PDGF-D), insulin-like growth factor-Ⅰ (IGF-Ⅰ), and transforming growth factor β 1 (TGF-β 1) were detected by Western blotting ( n=3). Eight male 8-week-old Sprague-Dawley rats were taken and a circular full-thickness skin defect wound was created on each side of the back. The wounds were divided into blank control group without any treatment and hydrogel group with the aforementioned prepared hydrogels loaded with adipose-derived stem cells applied. Wound healing was observed at 0 (immediately), 2, 4, 8, and 10 d after injury, and the wound healing rate was calculated at 2, 4, 8, and 10 d after injury. Wound tissue samples at 10 d after injury were collected, the new tissue formation was observed by hematoxylin-eosin staining; the concentrations of interleukin-1α (IL-1α), IL-6, IL-4, and IL-10 were detected by enzyme-linked immunosorbent assay method; the expressions of CD16 and CD206 positive cells were observed by immunohistochemical staining and the percentages of positive cells were calculated. The sample numbers in animal experiment were all 8. Results:At 24 h after stimulated contact, no skin edema was observed in the three groups of guinea pigs, and only mild skin erythema was observed in 7 guinea pigs in positive control group. At 48 h after stimulated contact, skin erythema was observed in 8 guinea pigs and skin edema was observed in 4 guinea pigs in positive control group, while no obvious skin erythema or edema was observed in guinea pigs in the other two groups. After 3 d of culture, the protein expression levels of PDGF-D, IGF-I, and TGF-β 1 in adipose-derived stem cells in hydrogel group were significantly higher than those in normal control group (with t values of 12.91, 11.83, and 7.92, respectively, P<0.05). From 0 to 10 d after injury, the wound areas in both groups gradually decreased, and the wounds in hydrogel group were almost completely healed at 10 d after injury. At 4, 8, and 10 d after injury, the wound healing rates in hydrogel group were (38±4)%, (54±5)%, and (69±6)%, respectively, which were significantly higher than (21±6)%, (29±7)%, and (31±7)% in blank control group (with t values of 3.82, 3.97, and 4.05, respectively, Pvalues all <0.05). At 10 d after injury, compared with those in blank control group, the epidermis in wound in hydrogel group was more intact, and there were increases in hair follicles, blood vessels, and other skin appendages. At 10 d after injury, the concentrations of IL-1α and IL-6 in wound tissue in hydrogel group were significantly lower than those in blank control group (with tvalues of 8.21 and 7.99, respectively, P<0.05), while the concentrations of IL-4 and IL-10 were significantly higher than those in blank control group (with tvalues of 6.57 and 9.03, respectively, P<0.05). The percentage of CD16 positive cells in wound tissue in hydrogel group was significantly lower than that in blank control group ( t=8.02, P<0.05), while the percentage of CD206 positive cells was significantly higher than that in blank control group ( t=7.21, P<0.05). Conclusions:The hydrogel loaded with mouse adipose-derived stem cells is non-allergenic, can promote the secretion of growth factors in adipose-derived stem cells, promote the polarization of macrophages to M2 phenotype in wound tissue in rats with full-thickness skin defects, and alleviate inflammatory reaction, thereby promoting wound healing.

Objective To observe the clinical effect of Zidi Mixture(with the actions of inducing astringency and arresting bleeding,clearing heat and cooling blood)combined with proton pump inhibitors(PPIs)in the treatment of peptic ulcer bleeding(PUB).Methods A retrospective analysis was conducted in 281 PUB patients hospitalized in the emergency department of the First Affiliated Hospital of Guangzhou University of Chinese Medicine from December 2019 to May 2023.According to the treatment options,the patients were divided into a control group(143 cases)and an observation group(138 cases).The patients in the control group were treated with PPIs together with routine basic treatment,and the patients in the observation group were treated with Zidi Mixture orally on the basis of treatment for the control group.The course of treatment lasted for 3 days.The changes of Glasgow-Blaschford Score(GBS),and the levels of hemoglobin(HGB),platelet count(PLT),blood urea nitrogen(BUN),serum creatinine(Cr),aspartate aminotransferase(AST)and alanine aminotransferase(ALT)were observed before and after treatment in the two groups.Moreover,the average hospitalization time and clinical efficacy of the two groups were compared.Results(1)After 3 days of treatment,the total effective rate of the observation group was 97.10%(134/138)and that of the control group was 91.61%(131/143),and the intergroup comparison(tested by chi-square test)showed that the efficacy of the observation group was superior to that of the control group,with a statistically significant difference(P＜0.05).(2)After treatment,the GBS scores in the two groups were decreased as compared with those before treatment(P＜0.05),and the decrease of GBS scores in the observation group was superior to that in the control group,the difference being statistically significant(P＜0.05).(3)The average hospitalization time in the observation group was(5.81±1.02)days,which was shorter than that in the control group[(6.13±1.12)days],and the difference was statistically significant(P＜0.05).(4)After treatment,the peripheral HGB and PLT levels in the two groups were higher than those before treatment(P＜0.05),and the BUN level was lower than that before treatment(P＜0.05),and the effects on increasing peripheral blood HGB and PLT levels and on decreasing BUN level in the observation group were significantly superior to those in the control group,the differences being statistically significant(P＜0.05).(5)In the course of treatment,the peripheral AST,ALT,Cr levels of the two groups were not elevated,and the differences were insignificant(P＞0.05).Conclusion Zidi Mixture combined with PPIs is effective in the treatment of PUB,which helps to improve relevant indicators of blood routine test and biochemical indexes and shorten hospitalization time,and its efficacy is stronger than that of PPIs alone.

Pulmonary fibrosis， chronic obstructive pulmonary disease， acute lung injury， asthma， and infectious pneumonia are common pulmonary inflammatory diseases worldwide. There is evidence that mitochondria produce a large amount of reactive oxygen species （ROS） when stimulated by inflammation， leading to oxidative stress that affects the onset and progression of pulmonary inflammatory diseases. With in-depth research， traditional Chinese medicine （TCM） has made significant progress in the treatment of pulmonary inflammatory diseases. An increasing amount of evidence indicates that single TCM and their active components， as well as TCM compound formulas， can improve mitochondrial oxidative stress status through multi-target and multi-pathway mechanisms， thereby effectively treating pulmonary inflammatory diseases. Currently， there is a lack of systematic review and summary of TCM research in this field both domestically and internationally. Therefore， this article aims to summarize and conclude the mechanisms by which TCM regulates mitochondrial oxidative stress to intervene in pulmonary inflammatory diseases， providing a scientific basis for its clinical application and offering new ideas and references for in-depth research on the prevention and treatment of pulmonary inflammatory diseases with TCM.