Diterpenoid ferruginol is a key intermediate in biosynthesis of active ingredients such as tanshinone and carnosic acid.However, the traditional process of obtaining ferruginol from plants is often cumbersome and inefficient. In recent years, the increasingly developing gene editing technology has been gradually applied to the heterologous production of natural products, but the production of ferruginol in microbe is still very low, which has become an obstacle to the efficient biosynthesis of downstream chemicals, such as tanshinone. In this study, miltiradiene was produced by integrating the shortened diterpene synthase fusion protein,and the key genes in the MVA pathway were overexpressed to improve the yield of miltiradiene. Under the shake flask fermentation condition, the yield of miltiradiene reached about(113. 12±17. 4)mg·L~(-1). Subsequently, this study integrated the ferruginol synthase Sm CYP76AH1 and Sm CPR1 to reconstruct the ferruginol pathway and thereby realized the heterologous synthesis of ferruginol in Saccharomyces cerevisiae. The study selected the best ferruginol synthase(Il CYP76AH46) from different plants and optimized the expression of pathway genes through redox partner engineering to increase the yield of ferruginol. By increasing the copy number of diterpene synthase, CYP450, and CPR, the yield of ferruginol reached(370. 39± 21. 65) mg·L~(-1) in the shake flask, which was increased by 21. 57-fold compared with that when the initial ferruginol strain JMLT05 was used. Finally, 1 083. 51 mg·L~(-1) ferruginol was obtained by fed-batch fermentation, which is the highest yield of ferruginol from biosynthesis so far. This study provides not only research ideas for other metabolic engineering but also a platform for the construction of cell factories for downstream products.
Saccharomyces cerevisiae/genetics* ; Diterpenes/metabolism* ; Metabolic Engineering ; Fermentation ; Abietanes

This paper explores the impacts of accelerated rehabilitation protocols following anterior cruciate ligament reconstruction(ACLR)on bone tunnel enlargement(BTE).While accelerated rehabilitation can shorten the recovery time and improve the knee function,it may increase the risk of BTE.In the early rehabilitation phase after ACLR,excessive early weight-bearing and rapid progression of knee flexion angles should be avoided,along with the proper use of braces.Continuous passive motion is not recommended in the early phase post-ACLR to prevent potential effects on BTE.Further research is needed to investigate the mechanisms of BTE and develop more effective rehabilitation strategies.This will help to select appropriate rehabilitation protocols for patients and balance functional recovery with the risk of BTE,thereby reducing the revision rate and improving postoperative outcomes.
Humans ; Anterior Cruciate Ligament Reconstruction/rehabilitation*

Cytotoxicity, usually represented by cell viability, is a crucial parameter for evaluating drug safety in vitro. Accurate prediction of cell viability/cytotoxicity could accelerate drug development in the early stage. In this study, by integrating cellular transcriptome and cell viability data using four machine learning algorithms (support vector machine (SVM), random forest (RF), extreme gradient boosting (XGBoost), and light gradient boosting machine (LightGBM)) and two ensemble algorithms (voting and stacking), highly accurate prediction models of 50% and 80% cell viability were developed with area under the receiver operating characteristic curve (AUROC) of 0.90 and 0.84, respectively; these models also showed good performance when utilized for diverse cell lines. Concerning the characterization of the employed Feature Genes, the models were interpreted, and the mechanisms of bioactive compounds with a narrow therapeutic index (NTI) can also be analyzed. In summary, the models established in this research exhibit superior capacity to those of previous studies; these models enable accurate high-safety substance screening via cytotoxicity prediction across cell lines. Moreover, for the first time, Cytotoxicity Signature (CTS) genes were identified, which could provide additional clues for further study of mechanisms of action (MOA), especially for NTI compounds.

Objective: To evaluate the comprehensive intervention effect of lunch for primary and secondary school students in Minhang District, so as to provide a theoretical and practical basis for lunch intervention in school. Methods: From October to December 2023, a convenience sampling method was used to select 1 937 students from one primary and secondary school in Minhang District.A comprehensive intervention measure focusing on "reducing oil and salt" for lunch recipe optimization and nutrition education was carried out, and a questionnaire survey was conducted to evaluate the intervention effect three months later. Chi square test and Wilcoxon rank test were used to compare the data before and after the intervention. Results: After intervention, the use of cooking oil and salt, the supply of protein and fat in primary and secondary school lunches were reduced, and had no obvious impact on energy and other major nutrients. After intervention, compared to before intervention, the proportion of primary school students who felt that lunch was greasy decreased (8.9%, 6.2%, χ 2=4.35), and the proportion of primary and secondary school students who felt that lunch were delicious decreased significantly (33.2%, 23.2%; 63.9%, 53.5%, χ 2=26.39, 17.52) ( P < 0.05 ). Secondary school students also felt reduced variety of food ingredients (46.9%, 38.3%, χ 2=16.05, P <0.05). In addition, after intervention, the total surplus rate of primary school students meals decreased (7.4%, 4.4%, χ 2=5.73), mainly reflected in the decrease of the surplus rate of staple foods (7.1%, 2.4%, χ 2=17.39), while the surplus rate of vegetable dishes increased ( 16.0 %, 21.2%, χ 2=6.01) ( P <0.05). Although there was no significant change in the total surplus rate of meals for secondary school students, the surplus rate of staple foods decreased (12.9%, 5.4%, χ 2=33.52), while the surplus rates of meat and vegetable dishes increased (11.2%, 26.9%; 17.5%, 33.2%, χ 2=74.26, 61.88) ( P <0.05). After intervention, there was no statistically significant difference in the overweight and obesity rates of primary school students ( χ 2=0.11,0.43) and secondary school students ( χ 2=0.01,0.00) compared to before intervention( P >0.05). After intervention, the lung capacity of primary school students [1 564 (1 269,1 890) mL] and sitting forward flexion [11.3 (7.6, 15.2) cm] increased compared to before intervention [1 522 (1 259, 1 819 ) mL, 10.5 (6.3, 13.5) cm] ( Z =2.20, 4.68, P <0.01), but there was no statistically significant difference in lung capacity and sitting forward flexion of secondary school students before and after intervention ( Z =-0.46, -0.08, P >0.05). Conclusion The comprehensive intervention of school lunch has promoted a significant decrease in the use of oil and salt in lunch and improved the quality of recipes, and has a positive impact on the situation of leftover lunch and the health of students to a certain extent.

Purpose To provide technical support for the use of echo-planar imaging(EPI)in the diagnosis of brain diseases,the image quality and diagnostic effect of single-shot echo-planar imaging(ssEPI)diffusion-weighted imaging(DWI)and multi-shot echo-planar imaging(msEPI)DWI sequences in the detection of brain diseases at 5.0T MR are analyzed.Materials and Methods A retrospective analysis was conducted on 42 patients with intracranial diseases who underwent T2-FLAIR,ssEPI DWI and msEPI DWI scans on a 5.0T MR system in the First Affiliated Hospital of USTC from August to September 2023.Two radiologists independently assessed image quality,measured distortion displacement,and compared signal-to-noise ratio,lesion-to-normal tissue contrast,contrast-to-noise ratio and apparent diffusion coefficient.Results msEPI sequence demonstrated significantly superior subjective scores,including geometric distortion,susceptibility artifacts,edge sharpness and overall image quality compared with those of ssEPI sequence(Z=5.728,4.197,5.766,5.777,all P<0.001).Quantitative analysis revealed substantial reduction in distortion displacement in msEPI sequence,including frontal lobe[(5.91±1.41)mm vs.(15.63±2.21)mm,t=34.050,P<0.001],anterior temporal lobe[(4.17±0.78)mm vs.(7.18±1.87)mm,t=12.263,P<0.001],posterior temporal lobe[(4.76±1.36)mm vs.(8.38±2.01)mm,t=21.336,P<0.001],cerebral diameter[(4.37±1.65)mm vs.(12.74±2.84)mm,t=23.255,P<0.001]and brainstem diameter[(0.80±0.63)mm vs.(1.98±1.63)mm,t=7.092,P<0.001],compared with ssEPI sequence.However,no statistically significant differences were observed in signal-to-noise ratio or contrast-to-noise ratio between the two sequences(P=0.848,0.638).Notably,msEPI sequences exhibited significantly enhanced lesion-normal tissue contrast compared with ssEPI sequences[221(131,311)vs.150(90,240),Z=3.89,P<0.001].Conclusion At 5.0T MRI,msEPI demonstrated superior image quality and diagnostic performance for craniocerebral diseases compared to ssEPI DWI sequences.

The integration of science and education is not only an important strategy for promoting social progress and technological development,but also a modern form of higher education aiming at cultivating innovative talents.Conducting scientific research training for undergraduate medical students is one of the important ways to cultivate their innovative abilities and comprehensive qualities.Our team proposed a"teaching,science,and ideology trinity"teaching model to comprehensively cultivate students' scientific research comprehensive abilities under the value orientation of ideological and political education by or-ganically integrating molecular biology experimental teaching with the scientific research training of under-graduate medical students.In this teaching activity,taking the experiment of gene polymorphism as an example,our team selected students with research potential from the whole grade and divided them into 4 project groups that were instructed by 4 teachers.The students were trained in the whole process of scien-tific research,including topic selection,project writing,experimental designing,application for research ethics,and project summary.Our team has always adhered to student-contentedness of educational con-cepts to stimulate students' intrinsic motivation throughout the teaching process.Students are the design-ers and implementers of the project,and teachers are only guides and promoters of learning.After this training,students not only became familiar with the writing and implementation of scientific research pro-jects,but also improved their literature reading,experimental designing,experimental skills,and prob-lem-solving abilities.More importantly,this teaching activity also cultivated students' awareness of re-search ethics and academic moral standards.

Objective To specifically extract and analyze nascent proteins synthesized by bone marrow mesenchymal stem cells(BMSCs)after transplantation into ischemic hearts using a technique employing mutant methionyl-tRNA synthetase(MetRSL247G)for nascent protein labeling,in order to explore the potential mechanisms of action in BMSCs post-transplantation.Methods Point mutation at position 274 of the MetRS gene in BMSCs was induced via lentiviral infection to enable azidonorleucine(ANL)-mediated labeling of nascent proteins in BMSCs.The labeling efficiency was verified by means of fluorescent non-canonical amino-acid tagging(FUNCAT).Thirty healthy female C57BL/6J mice(8-10 weeks old)were divided into control and experimental groups,with 15 mice in each group.The acute myocardial infarction model was constructed by ligating the left anterior descending coronary artery in experimental group,while control mice underwent only thoracotomy without coronary ligation.After modeling,both groups received intramyocardial injections of MetRSL247G-modified BMSCs(MetRSL247G-BMSCs)at 3 different sites in the peri-infarct ischemic region.Mice were intraperitoneally injected with ANL every 6 hours for 4 times on postoperative days 0,2,and 6(n=5 for each time point)respectively,euthanized 24 h after the last injection,and cardiac tissues were isolated.The newly synthesized and labeled proteins produced by BMSCs after transplantation into the myocardium of experimental and control groups were collected,using an enrichment technique for ANL-tagged proteins and liquid chromatography-tandem mass spectrometry(LC-MS)analysis.Gene ontology(GO)analysis,Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis,protein-protein interaction(PPI)analysis,and heatmap visualization analysis were performed to identify differentially expressed proteins at the 3 time points and screen key pathways and genes.Results Under fluorescence microscopy,the MetRSL247G lentivirus-infected BMSCs were observed to be labelled with mCherry signals,confirming the successful construction of the MetRSL247G-BMSCs cell line.Green fluorescent signals were detected only in nascent proteins in culture medium containing both MetRSL247G-BMSCs and ANL,validating the sensitivity and specificity of the labeling method.GO analysis revealed that differentially expressed proteins were primarily involved in basic cellular biological processes such as extracellular exosome formation,extracellular matrix organization,and focal adhesion.KEGG and PPI analyses indicated that the differential proteins were mainly involved in complement and coagulation cascade pathway,actin cytoskeleton regulation pathway,and apoptosis pathway.Heatmap analysis showed significantly upregulated expression of anti-apoptosis and cell adhesion-related factors in experimental group on day 1(P＜0.05),upregulated anti-apoptotic factors,pro-apoptotic factors,and cell adhesion-related factors on day 3(P＜0.05),and upregulated anti-apoptotic factors,cell differentiation-related factors,and cell adhesion-related factors on day 7(P＜0.05)compared with control group.Expression of apoptosis-inducing factor 1 was significantly downregulated on days 1 and 7(P＜0.05).On day 3,most differentially expressed proteins,including anti-apoptosis factors(Protein S100-A11,Clusterin,Gelsolin),pro-apoptosis factor(Cathepsin B),cell differentiation-related factor(Transgelin-2),and cell adhesion-related factors(Cofilin-1,Periostin,Fibronectin)were significantly upregulated(P＜0.05).Conclusions The MetRSL247G mutation enables BMSCs to incorporate ANL and synthesize labeled proteins,confirming the feasibility of this nascent protein labeling technique.Nascent proteins of BMSCs in ischemic myocardium primarily contribute to extracellular exosome secretion and extracellular matrix organization.BMSCs may adapt to and respond to ischemic and hypoxic environments by influencing complement and coagulation cascades,activating inflammatory factors,regulating actin cytoskeleton structure,and modulating apoptosis,thereby maintaining the survival of BMSCs.

Objective:To investigate the anatomical characteristics of the atlantoaxial joint associated with nonuniform settlement of the C 2 lateral mass (C 2LM-NUS) and its correlation with atlantoaxial osteoarthritis. Methods:A retrospective analysis was conducted on clinical and imaging data of 522 hospitalized patients (288 males, 234 females; mean age 60.8±11.2 years; range 18-83 years) who underwent CT scans of the head/neck or cervical spine at the Second Affiliated Hospital of Army Medical University between January 1, 2022 and December 31, 2022. Multiplanar reconstruction of CT data was performed to measure the settlement of the C 2 lateral mass (C 2LMS). Patients with a difference in bilateral C 2LMS (d-C 2LMS) >1.4 mm were classified into the C 2LM-NUS group (137 cases; 71 males, 66 females; mean age 63.3±11.6 years), while the normal group included 385 patients (217 males, 168 females; mean age 59.9±11.0 years). Imaging parameters of the atlantoaxial joint were measured, including the C 1, 2 coronal inclination angle (C 1, 2 CI), atlanto-dental interval (ADI), lateral atlanto-dental interval (LADI), coronal deviation angle of the odontoid (Od-CDA), and C 1, 2 relative rotation angle (C 1, 2 RRA). Osteoarthritis prevalence was recorded. A normal C 0-C 3 finite element (FE) model was constructed using CT data from a 48-year-old female in the normal group. A C 2LM-NUS FE model was developed based on anatomical differences between the C 2LM-NUS and normal groups, and stress distribution on the C 2 lateral mass articular surface was analyzed under flexion-extension, lateral bending, and axial rotation torques. Results:The C 2LM-NUS group exhibited asymmetric atlantoaxial joint morphology, with bilateral differences in C 1, 2CI and LADI of 8.5°(5.8°, 11.3°) and 0.8(0.1, 1.4) mm, respectively, significantly greater than those in the normal group [1.7°(0.8°, 2.7°) and 0.2(0.1, 0.5) mm, P<0.05]. Od-CDA and C 1, 2RRA were 3.9°(2.0°, 5.4°) and 7.2°(5.0°, 10.0°) in the C 2LM-NUS group, exceeding the normal group's values [0°(0°, 1.0°) and 0°(0°, 5.5°), P<0.05]. The prevalence of C 2LM-NUS was 37.8% in the atlantoaxial osteoarthritis group, significantly higher than in the non-osteoarthritis group (22.8%, P<0.05). Significant differences were observed in age (68.3±9.4 vs. 58.6±10.8 years), sex distribution (50/69 vs. 238/165), and C 1, 2RRA [5.6°(0°, 8.2°) vs. 3.8°(0°, 6.2°)] between the osteoarthritis and non-osteoarthritis groups ( P<0.05). After adjusting for age, sex, and C 1, 2RRA, binary logistic regression identified C 2LM-NUS as an independent risk factor for atlantoaxial osteoarthritis [ OR=2.024, 95% CI (1.300, 3.150), P<0.001]. FE analysis demonstrated a reduced C 1, 2 range of motion in the C 2LM-NUS model, with elevated stress concentrations on the settled side lateral mass during simulated flexion-extension, lateral bending, and rotation. Conclusions:The study indicated that C 2LM-NUS is associated with asymmetric anatomical changes in the atlantoaxial joint, increasing the risk of osteoarthritis. Stress concentration on the C 2 lateral mass articular surface, caused by C 2LM-NUS, is a biomechanical contributor to this heightened risk.

Enhancer of zeste homolog 2(EZH2)is a histone methyltransferase It mediates trimethylation of lysine 27 on histone H3,thereby facilitating the epigenetic silencing of downstream genes.In conjunc-tion with SUZ12,EED,and other components,it constitutes the polycomb repressive complex 2(PRC2)complex.While EZH2 is intricately involved in cellular proliferation and cardiac development,the chan-ges in its expression during cardiac terminal differentiation remain elusive.In this study,we employed differential gene expression analysis of embryonic and adult myocardial cells using the GEO database,and found that EZH2 is highly expressed in embryonic myocardium,but is present at very low levels in adult myocardium(P＜0.0001).Conversely,the expression changes of PRC2 members SUZ12 and EED are not as pronounced.Online analysis through the Tabula Muris database indicates that under physiological conditions,various cell subpopulations in the adult mouse heart exhibit negligible expression of EZH2.Immunohistochemical staining of mouse cardiac tissues shows that EZH2 is highly expressed in embryonic and neonatal myocardium but declines progressively from the first day after birth(P＜0.0001),becoming almost undetectable by the third day.Western blotting further confirms the rapid disappearance of EZH2 expression post-birth(P＜0.05),with EZH1 compensating for the downregulation of EZH2 to maintain H3K27me3 modification levels.Additionally,using the P19 teratocarcinoma stem cell model for cardio-myocyte differentiation,it is observed that EZH2 is significantly upregulated during the transition from cardiac progenitor cells to spontaneously beating cardiomyocytes,correlating with the expression of the cardiomyocyte transcription factor Gata4(P＜0.01).Targeted degradation of EZH2 using the small mole-cule drug MS1943 significantly inhibits the proliferation of induced cardiomyocytes,as evidenced by 5-e-thynyl-2'-deoxyuridine(EdU)incorporation assays(P＜0.01),and RT-qPCR reveals a marked in-crease in the expression of the proliferation inhibitor CDKN1A(P＜0.01).In summary,the high expres-sion of EZH2 in embryonic myocardial cells is associated with enhanced cell proliferation.The rapid loss of EZH2 expression postnatally correlates with the loss of proliferative capacity in cardiomyocytes,mark-ing it as a key indicator of cardiac terminal differentiation.

Objective:To investigate the anatomical characteristics of the atlantoaxial joint associated with nonuniform settlement of the C 2 lateral mass (C 2LM-NUS) and its correlation with atlantoaxial osteoarthritis. Methods:A retrospective analysis was conducted on clinical and imaging data of 522 hospitalized patients (288 males, 234 females; mean age 60.8±11.2 years; range 18-83 years) who underwent CT scans of the head/neck or cervical spine at the Second Affiliated Hospital of Army Medical University between January 1, 2022 and December 31, 2022. Multiplanar reconstruction of CT data was performed to measure the settlement of the C 2 lateral mass (C 2LMS). Patients with a difference in bilateral C 2LMS (d-C 2LMS) >1.4 mm were classified into the C 2LM-NUS group (137 cases; 71 males, 66 females; mean age 63.3±11.6 years), while the normal group included 385 patients (217 males, 168 females; mean age 59.9±11.0 years). Imaging parameters of the atlantoaxial joint were measured, including the C 1, 2 coronal inclination angle (C 1, 2 CI), atlanto-dental interval (ADI), lateral atlanto-dental interval (LADI), coronal deviation angle of the odontoid (Od-CDA), and C 1, 2 relative rotation angle (C 1, 2 RRA). Osteoarthritis prevalence was recorded. A normal C 0-C 3 finite element (FE) model was constructed using CT data from a 48-year-old female in the normal group. A C 2LM-NUS FE model was developed based on anatomical differences between the C 2LM-NUS and normal groups, and stress distribution on the C 2 lateral mass articular surface was analyzed under flexion-extension, lateral bending, and axial rotation torques. Results:The C 2LM-NUS group exhibited asymmetric atlantoaxial joint morphology, with bilateral differences in C 1, 2CI and LADI of 8.5°(5.8°, 11.3°) and 0.8(0.1, 1.4) mm, respectively, significantly greater than those in the normal group [1.7°(0.8°, 2.7°) and 0.2(0.1, 0.5) mm, P<0.05]. Od-CDA and C 1, 2RRA were 3.9°(2.0°, 5.4°) and 7.2°(5.0°, 10.0°) in the C 2LM-NUS group, exceeding the normal group's values [0°(0°, 1.0°) and 0°(0°, 5.5°), P<0.05]. The prevalence of C 2LM-NUS was 37.8% in the atlantoaxial osteoarthritis group, significantly higher than in the non-osteoarthritis group (22.8%, P<0.05). Significant differences were observed in age (68.3±9.4 vs. 58.6±10.8 years), sex distribution (50/69 vs. 238/165), and C 1, 2RRA [5.6°(0°, 8.2°) vs. 3.8°(0°, 6.2°)] between the osteoarthritis and non-osteoarthritis groups ( P<0.05). After adjusting for age, sex, and C 1, 2RRA, binary logistic regression identified C 2LM-NUS as an independent risk factor for atlantoaxial osteoarthritis [ OR=2.024, 95% CI (1.300, 3.150), P<0.001]. FE analysis demonstrated a reduced C 1, 2 range of motion in the C 2LM-NUS model, with elevated stress concentrations on the settled side lateral mass during simulated flexion-extension, lateral bending, and rotation. Conclusions:The study indicated that C 2LM-NUS is associated with asymmetric anatomical changes in the atlantoaxial joint, increasing the risk of osteoarthritis. Stress concentration on the C 2 lateral mass articular surface, caused by C 2LM-NUS, is a biomechanical contributor to this heightened risk.