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

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

We designed and synthesized eighteen lycorine derivatives with five different structural types, and evaluated their antiviral activities on a HCoV-OC43-infected H460 cell model. Structure-activity relationships suggested that the introduction of appropriate substituents on the 6N atom of lycorine was beneficial to activity. Compound 6a gave a good activity with the half effective concentration (EC₅₀) and selectivity index (SI) values of 2.36 μmol·L^-1 and 16.52, respectively. Surface plasmon resonance (SPR) result indicated that 6a might target the non-structural protein 12 (NSP12) subunit in RNA-dependent RNA polymerase (RdRp) of SARS-CoV-2 with the dissociation constant (K_D) value of 1.36 μmol·L^-1. Molecular docking indicated that 6a might act on nidovirus RdRp-associated nucleotidyltransferase (NiRAN) catalytic center of NSP12, distinct from the mechanism of nucleoside-like drugs such as remdesivir. This study provides scientific data for the development of lycorine derivatives into a new class of anti-SARS-CoV-2 small molecule inhibitors.

Objective To understand the respiratory protection competency of staff in hospitals.Methods Staff from six hospitals of different levels and characteristics in Beijing were selected,including doctors,nurses,medical technicians,and servicers,to conduct knowledge assessment on respiratory protection competency.According to exposure risks of respiratory infectious diseases,based on actual cases and daily work scenarios,content of respira-tory protection competency assessment was designed from three aspects:identification of respiratory infectious di-seases,transmission routes and corresponding protection requirements,as well as correct selection and use of masks.The assessment included 6,6,and 8 knowledge points respectively,with 20 knowledge points in total,all of which were choice questions.For multiple-choice questions,full marks,partial marks,and no mark were given respective-ly if all options were correct,partial options were correct and without incorrect options,and partial options were correct but with incorrect options.Difficulty and discrimination analyses on question of each knowledge point was conducted based on classical test theory.Results The respiratory protection competency knowledge assessment for 326 staff members at different risk levels in 6 hospitals showed that concerning the 20 knowledge points,more than 60％participants got full marks for 6 points,while the proportion of full marks for other questions was relatively low.Less than 10％participants got full marks for the following 5 knowledge points:types of airborne diseases,types of droplet-borne diseases,conventional measures for the prevention and control of healthcare-associated infec-tion with respiratory infectious diseases,indications for wearing respirators,and indications for wearing medical protective masks.Among the 20 knowledge questions,5,1,and 14 questions were relatively easy,medium,and difficult,respectively;6,1,4,and 9 questions were with discrimination levels of ≥0.4,0.30-0.39,0.20-0.29,and ≤0.19,respectively.Conclusion There is still much room for hospital staff to improve their respiratory protection competency,especially in the recognition of diseases with different transmission routes and the indications for wearing different types of masks.

Objective To study the role of sphingosine-1-phosphate(S1P)signal on the proliferation of breast cancer BT549 cells.Methods Cells were divided into control group and experimental group,experimental group were treated with 0.1,1.0,10.0 μmol·L-1 S1P receptor agonist SEW2871 for 72 h.Control group was cultured with 0.1％fetal bovine serum.Cell proliferation was detected by methyl thiazolyl tetrazolium(MTT)assay.Cell models of overexpressing S1P receptors in BT549 were divided into three groups:blank plasmid group(LUC),wild type S1P receptor overexpression group(WT),S1P receptor phosphorylation site mutation overexpression group(MUT);the proliferation ratio was detected by MTT,the number of cell clones was counted by colony formation experiment.S1P antagonist W146(10 μmol·L-1)and protein kinase(AKT)signaling inhibitor MK2206(90 nmol·L-1)were used to detect the role of S1P signaling in the proliferation of breast cancer cells.The expression of phosphorylate signal transducer and activator of transcription 3(p-STAT3),c-Myc proteins were detected by Western blot.Results The growth ratio of BT549 cells in control group and 0.1,1.0,10.0 μmol·L-1experimental groups were 1.00±0.03,1.13±0.06,1.06±0.10 and 1.07±0.03,0.1 μmol·L-1 SEW2871 promot the cell proliferation(P＜0.05).Compared between WT group,MUT group and LUC group,the growth rate and the number of clonal colonies were increased after overexpression of S1P receptor(all P＜0.05).The growth ratio of BT549 cells after treatment with W146 and MK2206 in the LUC group,WT group and MUT group were 1.25±0.12,1.31±0.03,1.43±0.14 and 0.87±0.15,0.77±0.03,0.88±0.02.Compared between MUT group,WT group and corresponding DMSO group,the differences were statistically significant(all P＜0.01).The number of cell clony formation number after treatment with W146 were 65.65±5.12,141.48±5.63 and 93.64±5.14;compared between MUT,WT group and corresponding DMSO group,the differences were statistically significant(all P＜0.05).The relative protein expression levels of p-STAT3 in LUC group,WT group and MUT group were 0.67±0.04,0.69±0.08 and 0.81±0.06,the relative protein expression levels of proto-oncogene c-Myc were 1.69±0.03,0.70±0.10 and 0.67±0.07,compared between WT group,MUT group and corresponding DMSO group,the difference was statistically significant(P＜0.05).Conclusion S1P signaling can promote proliferation in breast cancer BT549 cells,and the mechanism could be related to AKT and STAT3 signaling pathway.

Objective This study aimed to compare the current Essen rabies post-exposure immunization schedule(0-3-7-14-28)in China and the simple 4-dose schedule(0-3-7-14)newly recommended by the World Health Organization in terms of their safety,efficacy,and protection. Methods Mice were vaccinated according to different immunization schedules,and blood was collected for detection of rabies virus neutralizing antibodies(RVNAs)on days 14,21,28,35,and 120 after the first immunization.Additionally,different groups of mice were injected with lethal doses of the CVS-11 virus on day 0,subjected to different rabies immunization schedules,and assessed for morbidity and death status.In a clinical trial,185 rabies-exposed individuals were selected for post-exposure vaccination according to the Essen schedule,and blood was collected for RVNAs detection on days 28 and 42 after the first immunization. Results A statistically significant difference in RVNAs between mice in the Essen and 0-3-7-14 schedule groups was observed on the 35th day(P<0.05).The groups 0-3-7-14,0-3-7-21,and 0-3-7-28 showed no statistically significant difference(P>0.05)in RVNAs levels at any time point.The post-exposure immune protective test showed that the survival rate of mice in the control group was 20%,whereas that in the immunization groups was 40%.In the clinical trial,the RVNAs positive conversion rates on days 28(14 days after 4 doses)and 42(14 days after 5 doses)were both 100%,and no significant difference in RVNAs levels was observed(P>0.05). Conclusion The simple 4-dose schedule can produce sufficient RVNAs levels,with no significant effect of a delayed fourth vaccine dose(14-28 d)on the immunization potential.

Objective To understand the growth and development status and differences between small for gestational age(SGA)and appropriate for gestational age(AGA)preterm infants during corrected ages 0-24 months,and to provide a basis for early health interventions for preterm infants.Methods A retrospective study was conducted,selecting 824 preterm infants who received regular health care at the Guangzhou Women and Children's Medical Center from July 2019 to July 2022,including 144 SGA and 680 AGA infants.The growth data of SGA and AGA groups at birth and corrected ages 0-24 months were analyzed and compared.Results The SGA group had significantly lower weight and length than the AGA group at corrected ages 0-18 months(P<0.05),while there were no significant differences between the two groups at corrected age 24 months(P>0.05).At corrected age 24 months,85%(34/40)of SGA and 79%(74/94)of AGA preterm infants achieved catch-up growth.Stratified analysis by gestational age showed that there were significant differences in weight and length at corrected ages 0-9 months between the SGA subgroup with gestational age<34 weeks and the AGA subgroups with gestational age<34 weeks and≥34 weeks(P<0.05).In addition,the weight and length of the SGA subgroup with gestational age≥34 weeks showed significant differences compared to the AGA subgroups with gestational age<34 weeks and≥34 weeks at corrected ages 0-18 months and corrected ages 0-12 months,respectively(P<0.05).Catch-up growth for SGA infants with gestational age<34 weeks and≥34 weeks mainly occurred at corrected ages 0-12 months and corrected ages 0-18 months,respectively.Conclusions SGA infants exhibit delayed early-life physical growth compared to AGA infants,but can achieve a higher proportion of catch-up growth by corrected age 24 months than AGA infants.Catch-up growth can be achieved earlier in SGA infants with a gestational age of<34 weeks compared to those with≥34 weeks.

Objective To investigate the clinical characteristics and prognosis of pneumococcal meningitis(PM),and drug sensitivity of Streptococcus pneumoniae(SP)isolates in Chinese children.Methods A retrospective analysis was conducted on clinical information,laboratory data,and microbiological data of 160 hospitalized children under 15 years old with PM from January 2019 to December 2020 in 33 tertiary hospitals across the country.Results Among the 160 children with PM,there were 103 males and 57 females.The age ranged from 15 days to 15 years,with 109 cases(68.1% )aged 3 months to under 3 years.SP strains were isolated from 95 cases(59.4% )in cerebrospinal fluid cultures and from 57 cases(35.6% )in blood cultures.The positive rates of SP detection by cerebrospinal fluid metagenomic next-generation sequencing and cerebrospinal fluid SP antigen testing were 40% (35/87)and 27% (21/78),respectively.Fifty-five cases(34.4% )had one or more risk factors for purulent meningitis,113 cases(70.6% )had one or more extra-cranial infectious foci,and 18 cases(11.3% )had underlying diseases.The most common clinical symptoms were fever(147 cases,91.9% ),followed by lethargy(98 cases,61.3% )and vomiting(61 cases,38.1% ).Sixty-nine cases(43.1% )experienced intracranial complications during hospitalization,with subdural effusion and/or empyema being the most common complication[43 cases(26.9% )],followed by hydrocephalus in 24 cases(15.0% ),brain abscess in 23 cases(14.4% ),and cerebral hemorrhage in 8 cases(5.0% ).Subdural effusion and/or empyema and hydrocephalus mainly occurred in children under 1 year old,with rates of 91% (39/43)and 83% (20/24),respectively.SP strains exhibited complete sensitivity to vancomycin(100% ,75/75),linezolid(100% ,56/56),and meropenem(100% ,6/6).High sensitivity rates were also observed for levofloxacin(81% ,22/27),moxifloxacin(82% ,14/17),rifampicin(96% ,25/26),and chloramphenicol(91% ,21/23).However,low sensitivity rates were found for penicillin(16% ,11/68)and clindamycin(6% ,1/17),and SP strains were completely resistant to erythromycin(100% ,31/31).The rates of discharge with cure and improvement were 22.5% (36/160)and 66.2% (106/160),respectively,while 18 cases(11.3% )had adverse outcomes.Conclusions Pediatric PM is more common in children aged 3 months to under 3 years.Intracranial complications are more frequently observed in children under 1 year old.Fever is the most common clinical manifestation of PM,and subdural effusion/emphysema and hydrocephalus are the most frequent complications.Non-culture detection methods for cerebrospinal fluid can improve pathogen detection rates.Adverse outcomes can be noted in more than 10% of PM cases.SP strains are high sensitivity to vancomycin,linezolid,meropenem,levofloxacin,moxifloxacin,rifampicin,and chloramphenicol.[Chinese Journal of Contemporary Pediatrics,2024,26(2):131-138]

Objective To investigate the incidence rate,clinical characteristics,and prognosis of neonatal stroke in Shenzhen,China.Methods Led by Shenzhen Children's Hospital,the Shenzhen Neonatal Data Collaboration Network organized 21 institutions to collect 36 cases of neonatal stroke from January 2020 to December 2022.The incidence,clinical characteristics,treatment,and prognosis of neonatal stroke in Shenzhen were analyzed.Results The incidence rate of neonatal stroke in 21 hospitals from 2020 to 2022 was 1/15 137,1/6 060,and 1/7 704,respectively.Ischemic stroke accounted for 75％(27/36);boys accounted for 64％(23/36).Among the 36 neonates,31(86％)had disease onset within 3 days after birth,and 19(53％)had convulsion as the initial presentation.Cerebral MRI showed that 22 neonates(61％)had left cerebral infarction and 13(36％)had basal ganglia infarction.Magnetic resonance angiography was performed for 12 neonates,among whom 9(75％)had involvement of the middle cerebral artery.Electroencephalography was performed for 29 neonates,with sharp waves in 21 neonates(72％)and seizures in 10 neonates(34％).Symptomatic/supportive treatment varied across different hospitals.Neonatal Behavioral Neurological Assessment was performed for 12 neonates(33％,12/36),with a mean score of(32±4)points.The prognosis of 27 neonates was followed up to around 12 months of age,with 44％(12/27)of the neonates having a good prognosis.Conclusions Ischemic stroke is the main type of neonatal stroke,often with convulsions as the initial presentation,involvement of the middle cerebral artery,sharp waves on electroencephalography,and a relatively low neurodevelopment score.Symptomatic/supportive treatment is the main treatment method,and some neonates tend to have a poor prognosis.

Objective To explore the evidence,urinary biomarkers,and partial mechanisms of hypercoagulability in the pathogenesis of IgA vasculitis(IgAV).Methods Differential expression of proteins in the urine of 10 healthy children and 10 children with IgAV was screened using high-performance liquid chromatography-tandem mass spectrometry,followed by Reactome pathway analysis.Protein-protein interaction(PPI)network analysis was conducted using STRING and Cytoscape software.In the validation cohort,15 healthy children and 25 children with IgAV were included,and the expression levels of differential urinary proteins were verified using enzyme-linked immunosorbent assay.Results A total of 772 differential proteins were identified between the IgAV group and the control group,with 768 upregulated and 4 downregulated.Reactome pathway enrichment results showed that neutrophil degranulation,platelet activation,and hemostasis pathways were involved in the pathogenesis of IgAV.Among the differential proteins,macrophage migration inhibitory factor(MIF)played a significant role in neutrophil degranulation and hemostasis,while thrombin was a key protein in platelet activation and hemostasis pathways.PPI analysis indicated that thrombin directly interacted with several proteins involved in inflammatory responses,and these interactions involved MIF.Validation results showed that compared to healthy children,children with IgAV had significantly higher urine thrombin/creatinine and urine MIF/creatinine levels(P<0.05).Conclusions Thrombin contributes to the pathogenesis of IgAV through interactions with inflammatory factors.Urinary thrombin and MIF can serve as biomarkers reflecting the hypercoagulable and inflammatory states in children with IgAV.