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 aimed to explore the effects of Duzhong Decoction(DZD)-containing serum on the proliferation and osteoblast differentiation of MC3T3-E1 cells through L-type voltage-gated calcium channels(L-VGCCs). L-VGCCs inhibitors, nifedipine and verapamil, were used to block L-VGCCs in osteoblasts. MC3T3-E1 cells were divided into a control group, a low-dose DZD-containing serum(L-DZD) group, a medium-dose DZD-containing serum(M-DZD) group, a high-dose DZD-containing serum(H-DZD) group, a nifedipine group, a H-DZD + nifedipine group, verapamil group, and a H-DZD + verapamil group. The CCK-8 method was used for cell proliferation analysis, alkaline phosphatase(ALP) assay kits for intracellular ALP activity measurement, Western blot for protein expression level in cells, real-time fluorescence quantitative PCR technology for intracellular mRNA expression level determination, fluorescence spectrophotometer for free Ca~(2+) concentration determination in osteoblasts, and alizarin red staining(ARS) for mineralized nodule formation in osteoblasts. The experimental results show that compared to the control group, DZD groups can promote MC3T3-E1 cell proliferation, ALP activity, and mineralized nodule formation, increase intracellular Ca~(2+) concentrations, and upregulate the protein expression of bone morphogenetic protein 2(BMP2), collagen Ⅰ(COL1), α2 subunit protein of L-VGCCs(L-VGCCα2), and the mRNA expression of Runt-related transcription factor 2(RUNX2), and BMP2. After blocking L-VGCCs with nifedipine and verapamil, the intervention effects of DZD-containing serum were inhibited to varying degrees. Both nifedipine and verapamil could inhibit ALP activity, reduce mineralized nodule areas, and downregulate the expression of bone formation-related proteins. Moreover, the effects of DZD-containing serum on increasing MC3T3-E1 cell proliferation, osteoblast differentiation, and Ca~(2+) concentrations, upregulating the mRNA expression of osteoprotegerin(OPG) and protein expression of phosphorylated protein kinase B(p-Akt) and phosphorylated forkhead box protein O1(p-FOXO1), and upregulating phosphatase and tensin homolog(PTEN) expression were reversed by nifedipine. The results indicate that DZD-containing serum can increase the Ca~(2+) concentration in MC3T3-E1 cells to promote bone formation, which may be mediated by L-VGCCs and the PTEN/Akt/FoxO1 signaling pathway, providing a new perspective on the mechanism of DZD in treating osteoporosis.
Animals ; Osteoblasts/metabolism* ; Cell Proliferation/drug effects* ; Cell Differentiation/drug effects* ; Mice ; Drugs, Chinese Herbal/pharmacology* ; Calcium Channels, L-Type/genetics* ; Alkaline Phosphatase/genetics* ; Serum/chemistry* ; Cell Line ; Osteogenesis/drug effects* ; Bone Morphogenetic Protein 2/genetics*

Aim To investigate the effect of thioredox-in-interacting protein(TXNIP)on non-alcoholic fatty liver disease(NAFLD).Methods Littermate male wild(WT)mice and TXNIP gene whole-body knock-out(KO)mice were randomly divided into two groups:(1)normal diet(ND)group,and(2)The high-fat group,which was fed a high-fat diet(HFD)containing 60％fat for 12 weeks.Serum lipid-related indexes,liver injury indicators and hepatic fat content were detected using commercial kits.The protein lev-els of TXNIP,SLC25A1,SLC13A5,ACLY,CPT1a and PPARα were detected by Western blot.The gene ex-pressions of SLC25A1,SLC13A5 and ACLY were de-tected by RT-PCR.Results High fat diet increased TXNIP protein expression in the liver tissue.Compared with WT-HFD mice,the biochemical indexes in the se-rum and the liver of KO-HFD mice were improved.There was no significant difference in mRNA and pro-tein levels of SLC25A1 between the four groups of mice.For SLC13A5 and ACLY,the mRNA and protein levels of WT-HFD mice were up-regulated compared with WT mice,and these alterations were significantly restored in KO-HFD mice.Besides,compared with WT mice,the protein expressions of the fatty acid oxidation-related protein PPARα and CPT1a proteins in WT-HFD mice decreased,while the protein expressions of PPARα and CPT1 a in KO-HFD mice were significantly enhanced.Conclusion TXNIP gene knockout can improve hepatic steatosis and delay the progression of NAFLD by inhibiting the carbon flux of fatty acid syn-thesis and promoting fatty acid oxidation.

Aim To investigate the effect of thioredox-in-interacting protein(TXNIP)on non-alcoholic fatty liver disease(NAFLD).Methods Littermate male wild(WT)mice and TXNIP gene whole-body knock-out(KO)mice were randomly divided into two groups:(1)normal diet(ND)group,and(2)The high-fat group,which was fed a high-fat diet(HFD)containing 60％fat for 12 weeks.Serum lipid-related indexes,liver injury indicators and hepatic fat content were detected using commercial kits.The protein lev-els of TXNIP,SLC25A1,SLC13A5,ACLY,CPT1a and PPARα were detected by Western blot.The gene ex-pressions of SLC25A1,SLC13A5 and ACLY were de-tected by RT-PCR.Results High fat diet increased TXNIP protein expression in the liver tissue.Compared with WT-HFD mice,the biochemical indexes in the se-rum and the liver of KO-HFD mice were improved.There was no significant difference in mRNA and pro-tein levels of SLC25A1 between the four groups of mice.For SLC13A5 and ACLY,the mRNA and protein levels of WT-HFD mice were up-regulated compared with WT mice,and these alterations were significantly restored in KO-HFD mice.Besides,compared with WT mice,the protein expressions of the fatty acid oxidation-related protein PPARα and CPT1a proteins in WT-HFD mice decreased,while the protein expressions of PPARα and CPT1 a in KO-HFD mice were significantly enhanced.Conclusion TXNIP gene knockout can improve hepatic steatosis and delay the progression of NAFLD by inhibiting the carbon flux of fatty acid syn-thesis and promoting fatty acid oxidation.

Isoflavones which mainly distributed in leguminous plants have plenty of health benefits.Isoflavone synthase(IFS)is a membrane-associated cytochrome P450 enzyme(CYP450)which carries out the unique aryl-ring migration and hydroxylation.So far,few crystal structures of plant P450s have been obtained.We determined the crystal structure of IFS from Medicago truncatula at 1.9 ? by MAD method using a selenomethionine substituted crystal and conducted molecular docking and mutagenesis study.The structure of IFS complexed with imidazole exhibits the helix Ⅰa-loop-helix Ⅰβ motif which cor-responds to helix Ⅰ of other P450s.Compared with structures of common P450s,IFS/imidazole structure contains an extra domain,i.e.,the γ-domain.The structure reveals a homodimer in which the γ-domain of one molecule interacts with the β-domain of another.The plane of heme group makes an angle of ap-proximately 40° with the helix Ⅰa-loop-helix Ⅰβ motif.Molecular docking combined with mutagenesis study suggested that Trp-128 and Asp-300 might play important roles in substrate binding and recogni-tion.Phe-301,Ser-303 and Gly-305 from the helix Ⅰa-loop-helix Ⅰβ motif may play important roles in the aryl-ring migration.These novel structural features reveal insights into the unique reaction mechanism of IFS and provide a basis for engineering IFS in leguminous crops for health purpose.

Objective:To investigate the effects of Japan tallow(JT)on liver injury and gut microbiota regulation in type 2 diabetes mellitus(T2DM)mice,thereby providing a theoretical basis for developing therapeutic edible oils for diabetes treatment.Methods:T2DM animal model was established through a combined approach of nutritional intervention and chemical induction.Experimental animals were first fed a high-fat diet(HFD)for 6 weeks,followed by intraperitoneal injection of freshly prepared streptozotocin(STZ).After successful model establishment,the mice were divided into five groups(n=6 per group):control group without any intervention;T2DM group;HFD reversion to standard chow group;metformin group;and JT intervention group,which received respective treatments for 4 weeks.At the endpoint,fresh fecal samples were collected from all groups,and the gut microbiota composition was analyzed using 16s rDNA high-throughput sequencing.Liver histopathological changes were examined using histological methods.Results:Compared with the normal control(ND),T2DM mice showed significantly increased fasting blood glucose(FBG)levels,with evident hepatocyte lipid accumulation,steatosis,inflammatory cell infiltration,and widespread vacuolar and fatty degeneration.After Japan tallow(JT)intervention,FBG levels decreased significantly,liver color approximated normal appearance,and pathological morphology improved noticeably.16s rDNA sequencing analysis demonstrated that JT treatment could effectively regulate the intestinal microbiota structure in T2DM mice.Increased microbial α-diversity indices(Chao1,observed_species,Faith_pd,Simpson);At the phylum level,increased Verrucomicrobia abundance while decreased Proteobacteria were detected;At the family level,elevated Bifidobacteriaceae and reduced Porphyromonadaceae were seen;At the genus level,Bifidobacterium was promoted and Akkermansia proliferat while Escherichia and Klebsiella were downregulated.Conclusions:Japan tallow exhibits significant effects in alleviating liver tissue damage and regulating intestinal microbiota disorders in T2DM mice,our study indicated new theoretical basis for the research and development of potential strategy for diabetes.

Isoflavones which mainly distributed in leguminous plants have plenty of health benefits.Isoflavone synthase(IFS)is a membrane-associated cytochrome P450 enzyme(CYP450)which carries out the unique aryl-ring migration and hydroxylation.So far,few crystal structures of plant P450s have been obtained.We determined the crystal structure of IFS from Medicago truncatula at 1.9 ? by MAD method using a selenomethionine substituted crystal and conducted molecular docking and mutagenesis study.The structure of IFS complexed with imidazole exhibits the helix Ⅰa-loop-helix Ⅰβ motif which cor-responds to helix Ⅰ of other P450s.Compared with structures of common P450s,IFS/imidazole structure contains an extra domain,i.e.,the γ-domain.The structure reveals a homodimer in which the γ-domain of one molecule interacts with the β-domain of another.The plane of heme group makes an angle of ap-proximately 40° with the helix Ⅰa-loop-helix Ⅰβ motif.Molecular docking combined with mutagenesis study suggested that Trp-128 and Asp-300 might play important roles in substrate binding and recogni-tion.Phe-301,Ser-303 and Gly-305 from the helix Ⅰa-loop-helix Ⅰβ motif may play important roles in the aryl-ring migration.These novel structural features reveal insights into the unique reaction mechanism of IFS and provide a basis for engineering IFS in leguminous crops for health purpose.

Objective:To investigate the effects of Japan tallow(JT)on liver injury and gut microbiota regulation in type 2 diabetes mellitus(T2DM)mice,thereby providing a theoretical basis for developing therapeutic edible oils for diabetes treatment.Methods:T2DM animal model was established through a combined approach of nutritional intervention and chemical induction.Experimental animals were first fed a high-fat diet(HFD)for 6 weeks,followed by intraperitoneal injection of freshly prepared streptozotocin(STZ).After successful model establishment,the mice were divided into five groups(n=6 per group):control group without any intervention;T2DM group;HFD reversion to standard chow group;metformin group;and JT intervention group,which received respective treatments for 4 weeks.At the endpoint,fresh fecal samples were collected from all groups,and the gut microbiota composition was analyzed using 16s rDNA high-throughput sequencing.Liver histopathological changes were examined using histological methods.Results:Compared with the normal control(ND),T2DM mice showed significantly increased fasting blood glucose(FBG)levels,with evident hepatocyte lipid accumulation,steatosis,inflammatory cell infiltration,and widespread vacuolar and fatty degeneration.After Japan tallow(JT)intervention,FBG levels decreased significantly,liver color approximated normal appearance,and pathological morphology improved noticeably.16s rDNA sequencing analysis demonstrated that JT treatment could effectively regulate the intestinal microbiota structure in T2DM mice.Increased microbial α-diversity indices(Chao1,observed_species,Faith_pd,Simpson);At the phylum level,increased Verrucomicrobia abundance while decreased Proteobacteria were detected;At the family level,elevated Bifidobacteriaceae and reduced Porphyromonadaceae were seen;At the genus level,Bifidobacterium was promoted and Akkermansia proliferat while Escherichia and Klebsiella were downregulated.Conclusions:Japan tallow exhibits significant effects in alleviating liver tissue damage and regulating intestinal microbiota disorders in T2DM mice,our study indicated new theoretical basis for the research and development of potential strategy for diabetes.

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 explore the best preparation process and performance characterization of microcapsules containing ethanol extract from galangal.Methods With gum arabic(GA)-chitosan(CS)as capsule wall material,microcapsules were prepared by complex coacervation method.With drug loading and encapsulation efficiency as indexes,the optimal preparation technology of microcapsules was screened by orthogonal design method.The content of ethanol extract of galangal in microcapsules was determined by high performance liquid chromatography(HPLC).The prepared microcapsules were characterized by infrared spectrometer and scanning electron microscope.Results The optimum preparation conditions of microcapsules containing galangal ethanol extract were as follows:wall material ratio(GA/CS)6∶1,core to wall ratio 1∶1,coagulation time 45 minutes,curing agent dosage 3 mL.Under these conditions,the drug loading and encapsulation efficiency of microcapsules containing galangal ethanol extract were 27.17%and 80.07%,respectively,and the sustained release performance of microcapsules of galangal ethanol extract was superior to that of galangal ethanol extract.Conclusion The preparation of microcapsules containing galangal ethanol extract by complex coacervation method has good encapsulation,and the method is simple,stable and reliable,and has high feasibility.