Foodborne toxin Aflatoxin B_(1)induced glomerular podocyte inflammation through proteolysis of RelA,downregulation of miR-9 and CXCR4/TXNIP/NLRP3 pathway

Aflatoxin B_(1)(AFB_(1))is a naturally-occurring mycotoxin and recognized as the most toxic foodborne toxin,particularly causing damages to kidney.Glomerular podocytes are terminally differentiated epithelial cells.AFB_(1)induces podocyte inflammation,proteinuria and renal dysfunction.Studying the mechanism of AFB_(1)-induced podocyte inflammation and murine kidney dysfunction,we detected that AFB_(1)increased ubiquitindependent degradation of the transcription factor RelA through enhanced interaction of RelA with E3 ubiquitin ligase tripartite motif containing 7(TRIM7)in mouse podocyte clone-5(MPC-5)and mouse glomeruli.Reduction of RelA resulted in decreasing microRNA-9(miR-9)and activating the chemokine receptor 4(CXCR4),thioredoxin interacting protein(TXNIP),and NOD-like receptor pyrin domain-containing 3(NLRP3)signaling axis(CXCR4/TXNIP/NLRP3 pathway),leading to podocyte inflammation.We also determined that downregulation of miR-9 led to CXCR4 expression and the downstream TXNIP/NLRP3 pathway activation.Overexpression of miR-9 or deletion of CXCR4 suppressed AFB_(1)-induced CXCR4/TXNIP/NLRP3 pathway,resulting in alleviating podocyte inflammation and kidney dysfunction.Our findings indicated that ubiquitin-dependent proteolysis of RelA,downregulation of miR-9,and activation of CXCR4/TXNIP/NLRP3 pathway played an essential role in AFB_(1)-induced glomerular podocyte inflammation.Our study revealed a novel mechanism,via RelA,for the control of AFB_(1)’s nephrotoxicity,leading to an effective protection of food safety and public health.

Analysis on Antibacterial, Detumescent and Antioxidant Activity of Huoshan Large-leaf Yellow Tea

[Objectives] To provide experimental basis for the effective development and utilization of Huoshan large-leaf yellow tea resources and the screening of safe and effective active ingredients of large-leaf yellow tea. [Methods] The active substances of Huoshan large-leaf yellow tea were extracted by hot-water extraction, and the freeze-dried powder of Huoshan large-leaf yellow tea was obtained by freeze drying. The antibacterial activity of the extract was preliminarily confirmed using the Oxford cup method, and its antimicrobial spectrum was analyzed using 14 strains. A xylene-induced mouse auricle swelling test was carried out to detect the swelling inhibition rate of the extract and analyze its in-vitro detumescent activity. Then, the antioxidant activity of the extract was identified through a DPPH free radical scavenging capacity test and a ferric reducing antioxidant power assay. [Results] The extract had significant inhibitory effects on various bacteria. The extract could effectively inhibit the growth of Escherichia coli, Staphylococcus aureus, Enterococcus hirae, Acinetobacter baumannii, Klebsiella pneumonia, Pseudomonas aeruginosa, Bacillus subtilis , and other strains. The diameter of the inhibition zone increased with the increase of sample concentration. The extract had a significant inhibitory effect on auricle swelling induced by xylene in mice. When the concentration of the drug reached 1.0 mg/mL, its inhibition rate on mouse auricle swelling reached 55.2% ( P <0.01), slightly lower than the swelling inhibition rate of the aspirin group (66.52%, P <0.01). The results of the antioxidant test showed that large-leaf yellow tea extract also had strong activity. Within the concentration range of 0.1-1.0 mg/mL, its DPPH radical scavenging rate increased with the increase of sample concentration. Within the concentration range of 0.1-1.0 mg/mL, its DPPH radical scavenging rate increased with the increase of sample concentration. When the concentration reached 1.0 mg/mL, the scavenging rate reached 69.75%. The Fe 3+ -reduction capacity of the extract also increased with the increase of sample concentration within the concentration range of 0.1-2.5 mg/mL. When the concentration was 2.5 mg/mL, the reducing power of the extract reached 1.43±0.04. However, its DPPH free radical scavenging rate and reducing power were slightly lower than the capacity of V C at the same concentration. [Conclusions] The extract of Huoshan large-leaf yellow tea obtained by hot-water extraction had strong activity in many aspects, including inhibiting the growth of various microbes, subsiding swelling in vitro and resisting oxidation. These experimental results provide certain guiding significance for the basic research of Huoshan large-leaf yellow tea extract, as well as experimental data support for the subsequent development of functional foods and drugs of Huoshan large-leaf yellow tea.

Expression and Purification of Human Coagulation Factor X in Mammalian CHO-DG44 Cells

[Objectives]This study was conducted to obtain a Chinese hamster ovary cell line that stably expresses recombinant human coagulation factor X(rhFX),and to induce efficient expression of the target gene with different concentrations of methotrexate(MTX).[Methods]PCR was performed to obtain the rhFX gene,and a recombinant expression plasmid pOptiVEC-rhFX was constructed and subjected to double restriction endonuclease digestion and sequencing identification.CHO-DG44(DHFR-)cells were transfected by the liposome method,and the target protein was purified by affinity chromatography and detected by SDS-PAGE electrophoresis and Western blot.A cell line with efficient and stable expression of the target gene was obtained by increasing the concentration of MTX to select positive clones.[Results]PCR yielded a 1509 bp rhFX sequence,and the results of double digestion and sequencing showed that the constructed pOptiVEC-rhFX plasmid was correct.After transfection of cells,MTX significantly increased protein expression.When MTX reached 1.0μmol/L,the expression efficiency of the target protein was(9±0.27)μg/ml.The purity of the target protein purified by affinity chromatography was 93%,which could be used for subsequent experiments.The expression efficiency of rhFX in eukaryotic mammalian cells was improved by increasing MTX concentration,and an affinity chromatography purification process for the target protein was preliminarily established.[Conclusions]The results of this study provide data support for the expression and purification of rhFX,and will lay a solid foundation for the development of drugs related to rhFX.

Biocatalytic enhancement of laccase immobilized on ZnFe_(2)O_(4) nanoparticles and its application for degradation of textile dyes

Efficient and convenient treatment of industrial dyeing wastewater is of great significance to guarantee human and animal health.This work presented the enhanced catalytic activity at pH 3.0 of laccase immobilized on amino-functionalized ZnFe_(2)O_(4) nanoparticles(ZnFe_(2)O_(4)-laccase)and its application for the degradation of textile dyes.Due to the existence of a large number of oxygen vacancies on the surface of the ZnFe_(2)O_(4) nanoparticles,negative ions accumulated on the magnetic carriers,which resulted in a harsh optimal pH value of the ZnFe_(2)O_(4)-laccase.Laccase activity assays revealed that the ZnFe_(2)O_(4)-laccase possessed superior pH and thermal stabilities,excellent reusability,and noticeable organic solvent tolerance.Meanwhile,the ZnFe_(2)O_(4) laccase presented efficient and sustainable degradation of high concentrations of textile dyes.The initial decoloration efficiencies of malachite green(MG),brilliant green(BG),azophloxine,crystal violet(CV),reactive blue 19(RB19),and procion red MX-5B were approximately 99.1%,95.0%,93.3%,87.4%,86.1%,and 85.3%,respectively.After 10 consecutive reuses,the degradation rates of the textile dyes still maintained about 98.2%,92.5%,83.2%,81.5%,79.8%and 65.9%,respectively.The excellent dye degradation properties indicate that the ZnFe_(2)O_(4)-laccase has a technical application in high concentrations of dyestuff treatment.

The potential toxic side effects of flavonoids

Flavonoids are a class of phytochemical molecules abundant in many plants,fruits,vegetables,and leaves.Flavonoids possess a series of significant biological activities,including anticancer,antioxidant,antiviral,and antiinflammatory properties.They become an important source of dietary supplements and natural health products.Though many studies confirmed the safety of flavonoids,the potential toxicity of flavonoids is still a remarkable field of research to be explored.The enthusiasm for flavonoids expressed by the public has sometimes overlooked their toxicity and also consumed the flavonoids exceeding the body requirements.The current review focused on the potential toxicity of flavonoids to make the public consume flavonoids with caution.This review summarizes the current toxicity which has been reported in vivo and in vitro experiments.The toxicity involves carcinogenicity and mutation,liver and kidney toxicity,and the influence on the thyroid and reproductive function and intestinal flora disorders.The mechanism of toxicity is fully complicated,and current evidence indicates that natural flavonoid glycosides act on different targets with different doses in vivo and in vitro experiments.Though most kinds of flavonoids are considered safe,flavonoids proposed as food supplements need to be assessed their tolerable upper intake level as there have been reports of toxic flavonoids.

Analysis of Nonpolar Components from Ginseng of Different Ages

Nonpolar components from ginseng of different ages were extracted and analysed using a GC-MS technique to determine their chemical compositions. In total, 23 ingredients, mostly aliphatic compounds, were identified. The compounds extracted included 10,12-octadecadiynoic acid (12.81% - 36.43%), falcarinol (4.95% - 36.79%), n-hexadecanoic acid (0.60% - 9.70%), 9,12-octadecadienoic acid, ethyl ester (0.33% - 5.63%), 5,7-dodecadiyn-1,12-diol (0.97% - 3.85%), (Z)-9-octadecenamide (2.66% - 5.38%) and (Z,Z)-9,12-octadecadienoic acid (0.46% - 5.27%). The two major diyne compositions, falcarinol (8) and 10,12-octadecadiynoic acid (12), were the predominant components (over 50%) of the nonpolar extract of older ginseng. Moreover, the 10,12-octadecadiynoic acid obviously accumulated as the ginseng grew. Sitosterol, a universal metabolite in higher plants, makes up 55.80% of the content of 6-year-old ginseng, but markedly decreases in older ginseng. There was not much difference between the extracts of 8, 10, 12 and 16-year ginsengs, but the extracts of 6-year-old ginseng were distinctive.

Effect of Acid Treatment on the Saccharification of Wheat Bran Cellulose

[Objective] The aim was to improve the saccharification of wheat bran cellulose. [Method] Taking the wheat bran as raw materials, and using orthogonal method, the effects of acid concentration, temperature, times and substrate concentration on the saccharification were investigated. [Result] The influence of temperature on the acid treatment of the saccharification of wheat bran cellulose was significant. Influences of acid concentration on the hydrolysis were distinct. Influences of time and substrate concentration were insignificant. The optimal pretreatment conditions were 1.5% of sulfuric acid concentration and 0.067 g/ml of substrate concentration at 100 ℃ in three hours. Under this condition, the sugar concentration was 38.137 mg/ml, and the hydrolysis rate reached 51.485%. [Conclusion] The study improved the saccharification of wheat bran cellulose, which provided theoretical basis for the application of wheat bran industrial process.

Tandem 3'UTR Patterns and Gene Expression Profiles of Marc-145 Cells During PRRSV Infection

Porcine reproductive and respiratory syndrome virus(PRRSV) causes substantial economic losses to the global pig industry. Alternative polyadenylation(APA) is a mechanism that diversifies gene expression, which is important for tumorigenesis, development, and cell differentiation. However, it is unclear whether APA plays a role in the course of PRRSV infection. To address this issue, in this study we carried out a whole-genome transcriptome analysis of PRRSVinfected Marc-145 African green monkey kidney cells and identified 185 APA switching genes and 393 differentially expressed genes(DEGs). Most of these genes were involved in cellular process, metabolism, and biological regulation, and there was some overlap between the two gene sets. DEGs were found to be more directly involved in the antiviral response than APA genes. These findings provide insight into the dynamics of host gene regulation during PRRSV infection and a basis for elucidating the pathogenesis of PRRSV.

Geometrical Structures and Activities of Free Radical Scavenging Studies of Baicalein and Scutellarein

In order to study the free radical scavenging capacity and molecular structures of baicalein and scutellarein,the structure-activity relationship of these two molecules was analyzed.The geometric structures of the compounds were optimized by DMol3 code based on density functional theory.The theoretical parameters of the atomic charge distribution,the distribution of molecular frontier orbital,the energy difference and Fukui functions were calculated.Meantime,superoxide anion free radical and 1,1-diphenyl-2-picrylhydrazyl radical(DPPH)methods were used to determine the scavenging capacity of the compounds.The results showed that the scavenging rate of DPPH radicals and superoxide anion radicals increased with the increase of sample concentration,and had a dose-effect relationship.The radical-scavenging activities in the order of baicalein>scutellarein>BHT were showed.The p-π conjugation of the hydroxyl oxygen atom influenced the certain ability to repelling electrons in the molecular structures of baicalein and scutellarein based on the data of the atomic charge distribution,the distribution of molecular frontier orbital,the energy difference and Fukui functions.Hydroxyl groups were more susceptible to attack and exhibit free radical scavenging activity.The oxygen atom in the phenolic hydroxyl group of the molecule structure of the samples may be the reaction active sites where the electrophilic reaction occurred.These results offer useful theoretical bases for the research and application of antioxidant activities of substances containing such molecular structures.

Underpotential Deposition Preparation of Pt-loading AuNPs/Reduced Graphene Oxide and Its Catalytic Detection of Catechol

Ultralow Pt-loading Au nanoparticles have been fabricated on the surface of reduced graphene oxide （RGO） by using underpotential deposition （UPD） monolayer redox replacement process. The Pt/Au/RGO modified electrode exhibits an excellent electrocatalytic activity toward catechol and hydroquinone. Under the optimized condition, the separation of peak-to-peak between hydroquinone and catechol is 197 mV, which is wide enough to distinguish the isomers of benzenediol. Catechol is detected by the Pt/Au/RGO/GCE with a low detection limit in the presence of hydroquinone.

RIN enhances plant disease resistance via root exudate-mediated assembly of diseasesuppressive rhizosphere microbiota

The RIPENING-INHIBITOR(RIN)transcriptional factor is a key regulator governing fruit ripening.While RIN also affects other physiological processes,its potential roles in triggering interactions with the rhizosphere microbiome and plant health are unknown.Here we show that RIN affects microbiome-mediated disease resistance via root exudation,leading to recruitment of microbiota that suppress the soil-borne,phytopathogenic Ralstonia solanacearum bacterium.Compared with the wild-type(WT)plant,RIN mutants had different root exudate profiles,which were associated with distinct changes in microbiome composition and diversity.Specifically,the relative abundances of antibiosis-associated genes and pathogensuppressing Actinobacteria(Streptomyces)were clearly lower in the rhizosphere of rin mutants.The composition,diversity,and suppressiveness of rin plant microbiomes could be restored by the application of 3-hydroxyflavone and riboflavin,which were exuded in much lower concentrations by the rin mutant.Interestingly,RIN-mediated effects on root exudates,Actinobacteria,and disease suppression were evident from the seedling stage,indicating that RIN plays a dual role in the early assembly of diseasesuppressive microbiota and late fruit development.Collectively,our work suggests that,while plant disease resistance is a complex trait driven by interactions between the plant,rhizosphere microbiome,and the pathogen,it can be indirectly manipulated using"prebiotic"compounds that promote the recruitment of disease-suppressive microbiota.

Genetic diversity of Listeria monocytogenes isolates from farm products in Shanghai,China

Farm products are considered important vehicles for the transmission of Listeria monocytogenes(L.monocytogenes).The typing of L.monocytogenes from farm products contributes to the surveillance and source tracing of the pathogen.In this study,77 L.monocytogenes strains from seven farm product categories in Shanghai were analyzed by serological typing,multilocus sequence typing(MLST),pulsed-field gel electrophoresis(PFGE),and whole-genome nucleotide polymorphism(wgSNP).The results showed that the 77 isolates were classified into four serovars(1/2a,1/2c,1/2b,and 4b),and of these,1/2a(n=47)was the most prevalent.Seventeen sequence types(STs)were generated by MLST with two novel STs(ST1402 and ST1403),and 20 of 77 L.monocytogenes isolates had high genetic identity with previously documented outbreak isolates according to the minimum spanning tree from the MLST results.Moreover,34 PFGE patterns(PF1-PF34)were differentiated,and based on a similarity value higher than 80%by the unweighted pair group method dendrogram,the discriminatory index was relatively low(equal to 0.775).Furthermore,14 isolates were chosen and further analyzed by wgsNP based on the previous typing results,which demonstrated that wgSNP and MLST yielded mostly consistent typing results but higher resolution than PFGE.In conclusion,77 L.monocytogenes isolates from farm products collected in nine districts in Shanghai were highly genetically diverse,and 20 of these isolates had high relatedness with previously documented outbreak strains worldwide.The results indicate a possible cross-contamination risk of L.monocytogenes and a potential public health concern resulting from farm products during the supply chain in Shanghai,China.

Self-assembled ternary hybrid nanodrugs for overcoming tumor resistance and metastasis

Traditional chemotherapy exhibits a certain therapeutic effect toward malignant cancer,but easily induce tumor multidrug resistance(MDR),thereby resulting in the progress of tumor recurrence or metastasis.In this work,we deigned ternary hybrid nanodrugs(PEI/DOX@CXB-NPs)to simultaneously combat against tumor MDR and metastasis.In vitro results demonstrate this hybrid nanodrugs could efficiently increase cellular uptake at pH 6.8 by the charge reversal,break lysosomal sequestration by the proton sponge effect and trigger drugs release by intracellular GSH,eventually leading to higher drugs accumulation and cell-killing in drug-sensitive/resistant cells.In vivo evaluation revealed that this nanodrugs could significantly inhibit MDR tumor growth and simultaneously prevent A549 tumor liver/lung metastasis owing to the specifically drugs accumulation.Mechanism studies further verified that hybrid nanodrugs were capable of down-regulating the expression of MDR or metastasis-associated proteins,lead to the enhanced anti-MDR and anti-metastasis effect.As a result,the multiple combination strategy provided an option for effective cancer treatment,which could be potentially extended to other therapeutic agents or further use in clinical test.

Serum albumin complexed with ellagic acid from pomegranate peel and its metabolite urolithin B

As one of fruit waste by-products,the pomegranate peel is rich in bioactive compounds such as ellagic acid.Ellagic acid and its main gut microbial metabolite urolithin B have been reported to exhibit numerous biological activities and widely used as dietary supplements in the past decades.Interaction of these two compounds to serum albumin(SA)might affect their metabolism,efficacy,and body distribution.The interaction of ellagic acid and urolithin B with SA was investigated and BSA interference on the anti-cancer activity of these two compounds was also evaluated.Results of spectra experiments showed that ellagic acid and urolithin B could form complexes with bovine serum albumin(BSA)and urolithin B has a higher binding force and number of binding sites than ellagic acid when forming a complex with BSA.The results of molecular docking and molecular dynamics simulations suggested that ellagic acid and urolithin B tended to bind in site I rather than site II.The MTT assay results indicated that the IC_(50) value of ellagic acid decreased from 123.58μM to 55.91μM,while the IC_(50) value of urolithin B decreased from 83.67μM to 47.40μM.Ellagic acid and urolithin B can form complexes with serum albumin and the anti-cancer activity of ellagic acid and urolithin B was enhanced when combined with BSA.

小蓬草入侵地和原产地种群的遗传多样性和种群结构

外来入侵植物对全球生物多样性造成了危害。小蓬草(Erigeron canadensis L.)是危害最为严重的外来农业杂草之一,代表了洲际入侵的典型例子。本研究利用10个多态性SSR位点,分别对采自中国江苏和浙江省的入侵地和采自美国阿拉巴马州的原产地各5个种群、共计312个植株的基因型进行了遗传多样性和遗传结构分析。结果表明,江苏省和浙江省的入侵种群显示出与阿拉巴马州原产地种群相似的遗传多样性,表明入侵期间没有严重的遗传瓶颈。利用STRUCTURE对种群结构的分析结果显示,种群之间分化较低,在原产地和入侵范围内均只仅检测到两个基因群。在入侵种群中观察到的遗传多样性较高,表明在入侵初期可能存在多次引入或引入了遗传背景不同的繁殖体。上述研究为阐明小蓬草这一全球有害杂草在中国东部的入侵动态提供了新的证据。在防除实践中,应注意防范小蓬草入侵种群和本地种群之间的种子基因流传播,阻止除草剂抗性植株的引入和扩散。