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.

A primary hallmark of pathological cardiac hypertrophy is excess protein synthesis due to enhanced translational activity. However, regulatory mechanisms at the translational level under cardiac stress remain poorly understood. Here we examined the translational regulations in a mouse cardiac hypertrophy model induced by transaortic constriction (TAC) and explored the conservative networks versus the translatome pattern in human dilated cardiomyopathy (DCM). The results showed that the heart weight to body weight ratio was significantly elevated, and the ejection fraction and fractional shortening significantly decreased 8 weeks after TAC. Puromycin incorporation assay showed that TAC significantly increased protein synthesis rate in the left ventricle. RNA-seq revealed 1,632 differentially expressed genes showing functional enrichment in pathways including extracellular matrix remodeling, metabolic processes, and signaling cascades associated with pathological cardiomyocyte growth. When combined with ribosome profiling analysis, we revealed that translation efficiency (TE) of 1,495 genes was enhanced, while the TE of 933 genes was inhibited following TAC. In DCM patients, 1,354 genes were upregulated versus 1,213 genes were downregulated at the translation level. Although the majority of the genes were not shared between mouse and human, we identified 93 genes, including Nos3, Kcnj8, Adcy4, Itpr1, Fasn, Scd1, etc., with highly conserved translational regulations. These genes were remarkably associated with myocardial function, signal transduction, and energy metabolism, particularly related to cGMP-PKG signaling and fatty acid metabolism. Motif analysis revealed enriched regulatory elements in the 5' untranslated regions (5'UTRs) of transcripts with differential TE, which exhibited strong cross-species sequence conservation. Our study revealed novel regulatory mechanisms at the translational level in cardiac hypertrophy and identified conserved translation-sensitive targets with potential applications to treat cardiac hypertrophy and heart failure in the clinic.
Animals ; Humans ; Cardiomegaly/physiopathology* ; Ribosomes/physiology* ; Protein Biosynthesis/physiology* ; Mice ; Cardiomyopathy, Dilated/genetics* ; Ribosome Profiling

Preeclampsia (PE) is a severe gestational disorder characterized by hypertension and proteinuria, with a subset of cases exhibiting an immune-driven phenotype marked by placental overexpression of proinflammatory cytokines and chronic inflammatory damage, profoundly impacting fetal development. To elucidate the pathophysiology of this PE subtype, we established an inflammation-driven PE mouse model via lipopolysaccharide (LPS) intraperitoneal injection, systematically evaluating histopathological changes in maternal heart, liver, lung, kidney, and placenta, and integrating transcriptomic profiling to uncover molecular mechanisms. LPS administration robustly induced maternal hypertension and proteinuria, hallmarks of PE, without significantly altering organ or fetal weights. Histological analyses revealed pronounced inflammatory damage in the maternal lung, kidney, and placenta, with the lung exhibiting the most severe pathology, characterized by inflammatory cell infiltration, alveolar wall thickening, and interstitial edema-challenging the conventional focus on placental and renal primacy in PE. Placental labyrinth and junctional zones displayed extensive structural disruption and necrosis, indicating functional impairment. Transcriptomic analysis identified 27 inflammation-related genes consistently upregulated across tissues, with protein-protein interaction networks pinpointing Il1β, Il6, Ccl5, Ccl2, Cxcl10, Tlr2, and Icam1 as hub genes. Quantitative PCR validation confirmed Tlr2 as a central regulator, evidenced by significant upregulation of Tlr2 in lung, kidney, and placenta of LPS-induced PE mice, while Cxcl10 exhibited placenta-specific upregulation, suggesting a synergistic inflammatory axis in placental pathology. These findings highlight the lung as a critical, yet underappreciated, target in inflammation-driven PE, reframe the multi-organ inflammatory landscape of the disease, and nominate Tlr2 and Cxcl10 as potential diagnostic biomarkers and therapeutic targets, offering new avenues for precision intervention in PE.
Animals ; Female ; Pregnancy ; Mice ; Pre-Eclampsia/genetics* ; Inflammation ; Lipopolysaccharides/adverse effects* ; Disease Models, Animal ; Transcriptome ; Placenta/pathology* ; Phenotype

Ginsenoside Rg_2(GRg2) is a triterpenoid compound found in Panax notoginseng. This study explored its effects and mechanisms on diabetic retinopathy and angiogenesis. The study employed endothelial cell models induced by glucose or vascular endothelial growth factor(VEGF), the chorioallantoic membrane(CAM) model, the oxygen-induced retinopathy(OIR) mouse model, and the db/db mouse model to evaluate the therapeutic effects of GRg2 on diabetic retinopathy and angiogenesis. Transwell assays and endothelial tube formation experiments were conducted to assess cell migration and tube formation, while vascular area measurements were applied to detect angiogenesis. The impact of GRg2 on the retinal structure and function of db/db mice was evaluated through retinal thickness and electroretinogram(ERG) analyses. The study investigated the mechanisms of GRg2 by analyzing the activation of Yes-associated protein(YAP) and Toll-like receptors(TLRs) pathways. The results indicated that GRg2 significantly reduced cell migration numbers and tube formation lengths in vitro. In the CAM model, GRg2 exhibited a dose-dependent decrease in the vascular area ratio. In the OIR model, GRg2 notably decreased the avascular and neovascular areas, ameliorating retinal structural disarray. In the db/db mouse model, GRg2 increased the total retinal thickness and enhanced the amplitudes of the a-wave, b-wave, and oscillatory potentials(OPs) in the ERG, improving retinal structural disarray. Transcriptomic analysis revealed that the TLR signaling pathway was significantly down-regulated following YAP knockdown, with PCR results consistent with the transcriptome sequencing findings. Concurrently, GRg2 downregulated the expression of Toll-like receptor 4(TLR4), TNF receptor-associated factor 6(TRAF6), and nuclear factor-kappaB(NF-κB) proteins in high-glucose-induced endothelial cells. Collectively, GRg2 inhibits cell migration and tube formation and significantly reduces angiogenesis in CAM and OIR models, improving retinal structure and function in db/db mice, with its pharmacological mechanism likely involving the down-regulation of YAP expression.
Animals ; Ginsenosides/pharmacology* ; Diabetic Retinopathy/physiopathology* ; Mice ; YAP-Signaling Proteins ; Humans ; Male ; Signal Transduction/drug effects* ; Cell Movement/drug effects* ; Adaptor Proteins, Signal Transducing/genetics* ; Mice, Inbred C57BL ; Neovascularization, Pathologic/metabolism* ; Drugs, Chinese Herbal/administration & dosage* ; Panax notoginseng/chemistry* ; Endothelial Cells/metabolism* ; Transcription Factors/genetics* ; Angiogenesis

OBJECTIVE: To explore the effect of nano-hydroxyapatite/collagen composite (nHAC) on bone graft fusion after anterior cervical discectomy and fusion (ACDF) in patients with cervical spondylosis and low bone mass. METHODS: A retrospective analysis was conducted on 47 patients with low bone mass who underwent ACDF from 2017 to 2021. They were divided into the nHAC group and the allogeneic bone group according to different bone graft materials. The nHAC group included 26 cases, with 8 males and 18 females;aged 50 to 78 years old with an average of (62.81±7.79) years old;the CT value of C₂-C₇ vertebrae was (264.16±36.33) HU. The allogeneic bone group included 21 cases, with 9 males and 12 females;aged 54 to 75 years old with an average of (65.95±6.58) years old;the CT value of C₂-C₇ vertebrae was (272.39±40.44) HU. The visual analogue scale (VAS), neck disability index (NDI), and Japanese Orthopaedic Association (JOA) spinal cord function score were compared before surgery, 1 week after surgery, and at the last follow-up to evaluate the clinical efficacy. Imaging assessment included C₂-C₇ Cobb angle, surgical segment height, intervertebral fusion, and whether the cage subsidence occurred at 1 week after surgery and the last follow-up. RESULTS: The follow-up duration ranged from 26 to 39 months with an average of (33.27±3.34) months in the nHAC group and 26 to 41 months with an average of (31.86±3.57) months in the allogeneic bone group. At 1 week after surgery and the last follow-up, the VAS, NDI scores, and JOA scores in both groups were significantly improved compared with those before surgery, with statistically significant differences (P<0.05). At 1 week after surgery, the C₂-C₇ Cobb angles in the nHAC group and the allogeneic bone group were (14.26±10.32)° and (14.28±8.20)° respectively, which were significantly different from those before surgery (P<0.05). At the last follow-up, the C₂-C₇ Cobb angles in both groups were smaller than those at 1 week after surgery, with statistically significant differences (P<0.05). At 1 week after surgery, the height of the surgical segment in the nHAC group was (31.65±2.55) mm, and that in the allogeneic bone group was (33.63±3.26) mm, which were significantly different from those before surgery (P<0.05). At the last follow-up, the height of the surgical segment in both groups decreased compared with that at 1 week after surgery, with statistically significant differences (P<0.05). At the last follow-up, 39 surgical segments were fused and 6 cages subsided in the nHAC group;40 surgical segments were fused and 7 cages subsided in the allogeneic bone group;there was no statistically significant difference between the two groups (P>0.05). Compared with the CT value of vertebrae without cage subsidence, the CT value of vertebrae with cage subsidence in both groups was significantly lower, with a statistically significant difference (P<0.05). CONCLUSION The application of nHAC in ACDF for patients with low bone mass can achieve effective fusion of the surgical segment. There is no significant difference in improving clinical efficacy, intervertebral fusion, and cage subsidence compared with the allogeneic bone group. With the extension of follow-up time, the C₂-C₇ Cobb angle decreases, the height of the surgical segment is lost, and the cage subsides in both the nHAC group and the allogeneic bone group, which may be related to low bone mass. Low bone mass may be one of the risk factors for cervical spine sequence changes, surgical segment height loss, and cage subsidence after ACDF.
Humans ; Male ; Female ; Middle Aged ; Spondylosis/physiopathology* ; Spinal Fusion/methods* ; Cervical Vertebrae/surgery* ; Aged ; Diskectomy ; Durapatite ; Retrospective Studies ; Collagen/chemistry*

Objective To explore the safety and feasibility of intravenous dexmedetomidine(Dex)combined with targeted infusion of remifentanil in endoscopic retrograde cholangiopancreatography(ERCP)anesthesia in older adult patients.Methods From January to August 2021,98 older adult patients(≥65 years old)undergoing ERCP were randomly divided into TRP and TRD groups.The TRP group was anesthetized with target-controlled infusion of propofol and remifentanil and the TRD group was treated with Dex combined with target-controlled infusion of remifentanil.mean arterial pressure(MAP),heart rate(HR),electrocardiogram(ECG),respiratory rate(RR),pulse oxygen saturation(SpO2),bispectral index(BIS)before anesthesia induction(T0),immediately after induction of anesthesia(T1),endoscopic introduction(T2),duodenal papilla intubation(T3),endoscopy withdrawal(T4)and postoperative awakening(T5)were observed.Arterial blood gas analysis at different time points(T0,every 15 min after anesthesia induction and T5),PaO2,and PaCO2,were recorded at the above mentioned time points;and the remifentanil concentration in target-controlled infusion,operation time,recovery time(from infusion of remifentanil to consciousness recovery),anesthesia recovery time(from consciousness recovery to leaving the operating room),intraoperative body movement,Aldrete scores out of the room,Visual Analogue Scale(VAS)at 60 min after surgery,occurrence of post-operative adverse reactions,as well as the satisfaction of anesthesiologists,endoscopists,and patients were recorded.Results Compared with the TRP group,MAP at T1 and T3,SpO2 and RR at T1,T2,T3,and T4,and BIS at T2,T3,T4,and T5 increased,whereas HR at T1,T2,T3,and T4 decreased;the number of mandibular rests,incidence of hypoxemia,Aldrete score,and satisfaction increased,whereas the VAS score at 60 min after surgery decreased in the TRD group(P<0.05).There were no statistically significant differences in postoperative adverse reactions,PaO2 and PaCO2,target-controlled infusion remifentanil concentration,operation time,recovery time,and anesthesia recovery time between the two groups.Conclusion Compared with the target-controlled infusion of propofol-remifentanil,intravenous infusion of Dex combined with target-controlled infusion of remifentanil can reduce the incidence of hypoxemia in older adult patients during ERCP surgery,and the anesthesia regimen can meet the anesthesia needs of ERCP surgery,which is safe and feasible.

Objective:To explore the research hotspots and effective promotion paths of post market surveillance and supervise of medical consumables with non-active medical devices.Methods:Data mining methods were used to collect related journal literatures and documents from the websites of China regulatory institutions and the China National Knowledge Infrastructure(CNKI),order sub item data of medical device adverse event reports,extract the MeSH element words of literatures and documents,perform bibliometric analysis and visual display.Results:The number of medical devices adverse event reports in China has been increasing year by year,reaching 694 866 in 2022,in the four statistical years from 2019 to 2022,the number of reports on non-active medical devices and IVD reagents also showed a parallel increasing trend,accounting for about 65.00% of the total number of adverse event reports on medical devices in the year.The bibliometric analysis of journal literature shows that research in this field has received varying degrees of participation from regulatory institutions,universities,medical institutions,and enterprises.Regulatory institutions have contributed 46 articles,accounting for 56.79% of the total number of articles,followed by 28 articles from universities.The co-occurrence analysis shows that hot topic is focused in 5 clusters:quality management,risk management,international experiences discussion and adverse event surveillance and re-evaluation and real-world research.China regulatory institutions attach great importance to post market surveillance and supervise,and have issued more than 20 relevant documents since 2006,focusing on specific topics and gradually deepening around safety and effectiveness.Conclusion:The post market surveillance and supervise of medical devices,especially medical consumables based on non-active medical devices,need to be promoted synchronously in three dimensions:regulatory institutions,medical institutions,and enterprises.Universities,research institutes,and industry organizations should work in coordinating to strengthen the collection,identification,and active surveillance of risk signals based on adverse event surveillance,safety evaluation based on risk management,and conducting real-world research,research and develop risk control and corrective and preventive measures.

Objective:To assess a value of dual energy index(DEI)and effective atomic number(Zeff)of dual-energy computed tomography(DECT)combined with slope of energy spectrum curve in identifying the component of urinary tract stones.Methods:The clinical and DECT imaging data of 111 patients with urinary tract stones who admitted to Nantong Haimen People's Hospital from October 2019 to October 2022 were selected,and the diameters of the urinary tract stones of all patients were<5 mm.The components of outside body stones of all patients were analyzed by infrared spectrum.The accuracy,sensitivity and specificity of the DEI,Zeff,slope of energy spectrum curve and the combination of the them were respectively calculated in identifying the components of urinary tract stones.Results:In 111 patients,the patients with calcium oxalate stones were 75(67.57%),and ones with hydroxyapatite were 15 cases(13.51%),and ones with uric acid stones were 21 cases(18.92%),and there were no other type of stone included cysteine.The differences of CT values(F=487.691,P<0.001),DEI values(F=395.553,P<0.001),Zeff values(F=818.689,P<0.001)and the slopes of energy spectrum curves(H=19.615,P<0.001)were statistically significant among the three types of stones.The overall accuracies of DEI,Zeff and slope of energy spectrum curve were 87.39%(97/111),84.68%%(94/111)and 81.98%(91/111)in identifying the components of urinary tract stone.The range of diagnostic accuracies of DEI,Zeff and the slope of energy spectrum curve was between 80%and 100%for calcium oxalate stones,hydroxyapatite and uric acid stones.The overall accuracy of DEI,Zeff combined with slope of energy spectrum curve was 94.59%(105/111)in identifying the components of urinary tract stones.The diagnostic accuracies of DEI,Zeff combined with slope of energy spectrum curve were respectively 94.59%,94.59 and 100%for calcium oxalate stones,hydroxyapatite and uric acid stones.Conclusion:Compared with the single indicator of DECT,the DEI and Zeff combined with the slope of the energy spectrum curve showed better diagnostic accuracy in identifying the components urinary track stones.