NAD(P)H oxidases were detected in suspension cultured cells of ginseng (Panax ginseng C. A. Meyer). The activities of these enzymes were induced by an elicitor (Cle) extracted from cell walls of Col-letotrichum lagera...NAD(P)H oxidases were detected in suspension cultured cells of ginseng (Panax ginseng C. A. Meyer). The activities of these enzymes were induced by an elicitor (Cle) extracted from cell walls of Col-letotrichum lagerarium. In addition, Cle induced an oxidative burst and enhanced the synthesis of saponin, activity of phenylalanine ammonialyase (PAL) , accumulation of chalcone synthase (CHS) and the transcription of a hydroxyproline-rich glycoprotein gene ( hrgp ) . Pre-treatments with DPI and quinacrine (two inhibitors of mammalian neutrophil plasma membrane NADPH oxidase) for 30 min prior to Cle addition blocked the NAD(P)H oxidase activity induced by Cle. These inhibitors also inhibited the release of H2C2, the synthesis of saponin, PAL activity and CHS accumulation. Our data revealed homology between plasma membrane NAD(P)H oxidases of mammalian neutrophil cells and ginseng suspension cells. They also indicated that deactivated NAD(P)H oxidases catalysed the release of H2O2 and that H2O2 was functioning as a second messenger stimulating PAL activity, saponin synthesis and hrgp transcription. Elevations of Ca2 + and protein phos-phorylation/dephosphorylation were required for this defense process. We propose that NAD(P)H oxidases mediate the processes of Cle-induced defense responses in ginseng suspensions, and postulate the existence of a signalling cascade including extracellular Cle stimulation, activation of plasma membrane NAD(P)H oxidases, release of H2O2, and the intracellular responses of metabolism and gene transcription in ginseng suspension cells.展开更多
In this study an effort has been made to use plant polyphenol oxidases; potato （Solanum tuberosum） and brinjal （Solanum melongena）, for the treatment of various important dyes used in textile and other industries....In this study an effort has been made to use plant polyphenol oxidases; potato （Solanum tuberosum） and brinjal （Solanum melongena）, for the treatment of various important dyes used in textile and other industries. The ammonium sulphate fractionated enzyme preparations were used to treat a number of dyes under various experimental conditions. Majority of the treated dyes were maximally decolorized at pH 3.0. Some of the dyes were quickly decolorized whereas others were marginally decolorized. The initial first hour was sufficient for the maximum decolorization of dyes. The rate of decolorization was quite slow on long treatment of dyes. Enhancement in the dye decolorization was noticed on increasing the concentration of enzymes. The complex mixtures of dyes were treated with both preparations of polyphenol oxidases in the buffers of varying pH values. Potato polyphenol oxidase was significantly more effective in decolorizing the dyes to higher extent as compared to the enzyme obtained from brinjal polyphenol oxidase. Decolorization of dyes and their mixtures, followed by the formation of an insoluble precipitate, which could be easily removed simply by centrifugation.展开更多
Background: Glucose oxidase(GOD), an aerobic dehydrogenase, has been used as an antibiotic substitute in feed.A study was conducted to evaluate the differential effects of 2 different GODs fermented by Aspergillus nig...Background: Glucose oxidase(GOD), an aerobic dehydrogenase, has been used as an antibiotic substitute in feed.A study was conducted to evaluate the differential effects of 2 different GODs fermented by Aspergillus niger or Penicillium amagasakiense on caecal microbiota and to further illuminate the potential roles of changes in the gut microbiota in regulating the growth performance and meat quality of broiler chickens.Results: A total of 420 one-day-old healthy Arbor Acres broilers were randomly assigned to 4 treatments: the control group,the antibiotic growth promoter(AGP) supplementation group, and the GOD-A and GOD-P(GODs produced by A. niger and P. amagasakiense, respectively) groups. As a result, supplementation with GOD produced by P. amagasakiense could significantly improve the average daily weight gain and average daily feed intake of broilers before 21 days of age by significantly increasing the enzymatic activities of jejunal amylase and those of ileal amylase, chymotrypsin, and lipase in21-day-old broilers and could increase the enzymatic activities of duodenal amylase, jejunal amylase and lipase, and ileal chymotrypsin and lipase in 42-day-old broilers. Meanwhile, compared with AGP treatment, supplementation with GOD produced by P. amagasakiense significantly decreased the L value of 21-day-old broilers and the Δp H and L* value of 42-day-old broilers, while supplementation with GOD produced by A. niger significantly increased the p H24 hvalue of 21-day-old and 42-day-old broilers by reducing plasma malondialdehyde content. By using 16 S r RNA sequencing, we found that the beneficial bacteria and microbiota in broilers were not disturbed but were improved by GOD supplementation compared with ADP treatment, including the genera Eubacterium and Christensenel a and the species uncultured_Eubacterium_sp,Clostridium_asparagiforme, and uncultured_Christensenel a_sp, which were positively related to the improved intestinal digestive enzymatic activities, growth performance, and meat quality of broilers.Conclusion: The altered gut microbiota induced by supplementation with glucose oxidase produced by P. amagasakiense mediate better regulatory effects on the meat quality and growth performance of broilers than that induced by supplementation with glucose oxidase produced by A. niger.展开更多
Aims: We focused on DNA methylation of the promoter regions of the Monoamine Oxidase (MAO) A and B genes from postmortem brains of subjects with schizophrenia. Methods: We determined levels of DNA methylation using ge...Aims: We focused on DNA methylation of the promoter regions of the Monoamine Oxidase (MAO) A and B genes from postmortem brains of subjects with schizophrenia. Methods: We determined levels of DNA methylation using genomic DNA samples purified from four brain areas: prefrontal cortex (PFC), hippocampus, occipital cortex and nucleus accumbens (NAc), by a bisulfite sequencing method from seven normal subjects and six subjects with schizophrenia. Results: Although very few methylated CpGs of the MAOA and MAOB genes were detected in male samples, various DNA methylation patterns were present in female samples, and some differences were found in such patterns between normal subjects and subjects with schizophrenia. In the PFC, the average level of methylation of both genes was significantly higher in subjects with schizophrenia than in normal subjects. The content of highly methylated alleles of the MAOA gene in the NAc was significantly associated with schizophrenia, with similar results obtained for the MAOB gene in both the NAc and PFC. Some CpG sites showed higher levels of methylation in schizophrenia than in normal subjects. Conclusions: Levels of methylation were quite high in NAc and PFC in female subjects with schizophrenia compared with those in female normal subjects.展开更多
Age-related Ecto-Nicotinamide Adenine Dinucleotide Oxidase Disulfide Thiol Exchangers 3 (ENOX3) or age-related NADH oxidases (arNOX) are expressed at the cell surface as five members of the TM-9 superfamily, initially...Age-related Ecto-Nicotinamide Adenine Dinucleotide Oxidase Disulfide Thiol Exchangers 3 (ENOX3) or age-related NADH oxidases (arNOX) are expressed at the cell surface as five members of the TM-9 superfamily, initially membrane anchored, all functionally similar, with the N-termini exposed at the cell’s exterior. ECTO-NOXes are cell surface proteins with both time-keeping CoQH2 [NAD(P)H] oxidase and protein disulfidethiol interchange activities. They are designated as ECTO-NOX proteins because of their localization on the outer surface of the plasma membrane and to distinguish them from the phox-NOXes of host defense. A ca. 30 kDa N-terminal fragment is cleaved and accumulates in body fluids (serum, saliva, urine, perspiration). arNOXes appear around age 30 and increase steadily thereafter. Reduced quinones, i.e., reduced coenzyme Q, of the plasma membrane are natural substrates. NAD(P)H is oxidized as an artificial substrate. In one phase of the arNOX cycle electrons are transferred to oxygen to generate superoxide. Substrates for the shed forms of arNOX appear to be proteins of body fluids. Circulating lipoproteins and skin matrix proteins emerge as potentially important health-related targets. Through oxidation of collagen, elastin and other proteins of the skin matrix, arNOXes are major contributors to skin aging through tyrosine and thiol oxidation and subsequent cross linking. The main destructive action of arNOX, however, may be to directly oxidize circulating lipoproteins. arNOX in the blood is structured as an integral component of the LDL particle through site-specific binding. As such, arNOXes are implicated as major risk factors for cardiovascular disease due to specific oxidation of LDLs. The superoxide produced and its conversion to hydrogen peroxide would be one part of the potentially destructive properties by contribution to lipid oxidation. Inhibition of arNOX proteins provides a rational basis for anti-aging interventions and their elimination as a major risk factor of atherogenesis.展开更多
Poplar canker,caused by the fungus Cytospora chrysosperma,results in tremendous losses in poplar plantations in China.Although NADPH oxidases(NOXs)play important roles in the development and pathogenicity of several p...Poplar canker,caused by the fungus Cytospora chrysosperma,results in tremendous losses in poplar plantations in China.Although NADPH oxidases(NOXs)play important roles in the development and pathogenicity of several pathogenic fungi,their roles in C.chrysosperma remain unclear.In this study,we characterized three NOX genes(CcNox1,CcNox2,and CcNoxR)in C.chrysosperma.All three genes were highly upregulated during poplar branch infection,and deletion of any of them severely reduced virulence on poplar branches.Furthermore,deletion of either CcNox1 or CcNoxR resulted in a significant increase in endogenous reactive oxygen species production in hyphae,enhanced influx of Ca^(2+),the disruption of redox homeostasis and compromised mitochondrial integrity.Moreover,biosynthesis and secretion of a known virulence factor oxalic acid was obviously defective and exogenous oxalic acid supplementation rescued the virulence of the mutants.Taken together,our findings reveal that NOXs play important roles in redox homeostasis,mitochondrial integrity and pathogenicity in C.chrysosperma.展开更多
Recent advancements in data technology offer immense opportunities for the discovery and development of new enzymes for the green synthesis of chemicals.Current protein databases predominantly prioritize overall seque...Recent advancements in data technology offer immense opportunities for the discovery and development of new enzymes for the green synthesis of chemicals.Current protein databases predominantly prioritize overall sequence matches.The multi-scale features underpinning catalytic mechanisms and processes,which are scat-tered across various data sources,have not been sufficiently integrated to be effectively utilized in enzyme mining.In this study,we developed a sequence-and taxonomic-feature evaluation driven workflow to discover enzymes that can be expressed in E.coli and catalyze chemical reactions in vitro,using alcohol oxidase(AOX)for demonstration,which catalyzes the conversion of methanol to formaldehyde.A dataset of 21 reported AOXs was used to construct sequence scoring rules based on features,including sequence length,structural motifs,catalytic-related residues,binding residues,and overall structure.These scoring rules were applied to filter the results from HMM-based searches,yielding 357 candidate sequences of eukaryotic origin,which were catego-rized into six classes at 85%sequence similarity.Experimental validation was conducted in two rounds on 31 selected sequences representing all classes.Among these selected sequences,19 were expressed as soluble proteins in E.coli,and 18 of these soluble proteins exhibited AOX activity,as predicted.Notably,the most active recombinant AOX exhibited an activity of 8.65±0.29 U/mg,approaching the highest activity of native eukaryotic enzymes.Compared to the established UniProt-annotation-based workflow,this feature-evaluation-based approach yielded a higher probability of highly active recombinant AOX(from 8.3%to 19.4%),demonstrating the efficiency and potential of this multi-dimensional feature evaluation method in accelerating the discovery of active enzymes.展开更多
Background:A significant proportion of patients still cannot benefit from existing targeted therapies and immunotherapies,making the search for new treatment strategies extremely urgent.In this study,we combined integ...Background:A significant proportion of patients still cannot benefit from existing targeted therapies and immunotherapies,making the search for new treatment strategies extremely urgent.In this study,we combined integrate public data analysis with experimental validation to identify novel prognostic biomarkers and therapeutic targets for lung adenocarcinoma(LUAD).Methods:We analyzed RNA and protein databases to assess the expression levels of cytochrome C oxidase 5B(COX5B)in LUAD.Several computational algorithms were employed to investigate the relationship between COX5B and immune infiltration in LUAD.To further elucidate the role of COX5B in LUAD,we utilized multiple experimental approaches,including quantitative reverse transcription PCR assays,western blot,immunohistochemistry,electron microscopy,flow cytometry,and EdU proliferation assays.Results:We revealed that COX5B was significantly elevated in LUAD and positively correlated with poor prognosis of LUAD patients.Analysis of co-expression network indicated that COX5B may take part in the intracellular adenosine triphosphate(ATP)synthesis through the oxidative phosphorylation pathway.There was a negative correlation between COX5B expression and immune infiltration in LUAD.Furthermore,we validated that COX5B levels were significantly elevated in both LUAD tissues and cell lines.Specifically,immunohistochemistry(IHC)assays revealed a 2.32-fold increase of COX5B in tumor tissues compared to that in adjacent normal tissues(p=0.0044).Additionally,COX5B knockdown disrupted the redox homeostasis,ultimately suppressed the proliferation of LUAD cells.Subsequent investigations demonstrated that berberine effectively targeted COX5B,diminishing its protein expression and consequently inhibiting cell proliferation and tumor growth in LUAD.Conclusions:This study established that upregulated COX5B was positive associated with poor patient prognosis in LUAD,elucidating the mechanisms by which berberine targets COX5B to inhibit tumor growth,thereby providing a novel therapeutic target and strategy for the clinical management of LUAD.展开更多
Copper-radical oxidases(CROs)catalyze the two-electron oxidation of a large number of primary alcohols includ-ing carbohydrates,polyols and benzylic alcohols as well as aldehydes and𝛼-hydroxy-carbonyl compound...Copper-radical oxidases(CROs)catalyze the two-electron oxidation of a large number of primary alcohols includ-ing carbohydrates,polyols and benzylic alcohols as well as aldehydes and𝛼-hydroxy-carbonyl compounds while reducing molecular oxygen to hydrogen peroxide.Initially,CROs like galactose oxidase and glyoxal oxidase were identified only in fungal secretomes.Since the last decade,their representatives have also been identified in some bacteria.CROs are grouped in the AA5 family of“auxiliary activities”in the database of Carbohydrate-Active enzymes.Despite low overall sequence similarity and different substrate specificities,sequence alignments and the solved crystal structures revealed a conserved architecture of the active sites in all CROs,with a mononuclear copper ion coordinated to an axial tyrosine,two histidines,and a cross-linked cysteine-tyrosyl radical cofactor.This unique post-translationally modified protein cofactor has attracted much attention in the past,which resulted in a large number of reports that shed light on key steps of the catalytic cycle and physico-chemical properties of CROs.Thanks to their broad substrate spectrum accompanied by the only need for molecular oxygen for catal-ysis,CROs since recently experience a renaissance and have been applied in various biocatalytic processes.This review provides an overview of the structural features,catalytic mechanism and substrates of CROs,presents an update on the engineering of these enzymes to improve their expression in recombinant hosts and to enhance their activity,and describes their potential fields of biotechnological application.展开更多
Apoplastic ascorbate oxidases(AOs)play a critical role in reactive oxygen species(RoS)-mediated innate host immunity by regulating the apoplast redox state.To date,little is known about how apoplastic effectors of the...Apoplastic ascorbate oxidases(AOs)play a critical role in reactive oxygen species(RoS)-mediated innate host immunity by regulating the apoplast redox state.To date,little is known about how apoplastic effectors of the riceblast fungus Magnaportheoryzaemodulate the apoplast redox state of rice to subvert plant immunity.In this study,we demonstrated that M.oryzae MoAo1 is an Ao that plays a role in virulence by modulating the apoplast redox status of rice cells.We showed that MoAo1 inhibits the activity of rice OsAO3and OsAO4,which also regulate the apoplast redox status and plant immunity.In addition,we found that MoAo1,OsAO3,andOsAO4 allexhibit polymorphic variations whosevaried interactions orchestrate pathogen virulence and rice immunity.Taken together,our results reveal a critical role for extracellular redox enzymes during rice blast infection and shed light on the importance of the apoplast redox state anditsregulation inplant-pathogeninteractions.展开更多
The synergistic effects of cellobiose dehydro-genase (CDH) and manganese-dependent peroxidases (MnP) on the degradation of kraft pulp cellulolytic enzyme lignin (CEL) were investigated. Addition of CDH significantly i...The synergistic effects of cellobiose dehydro-genase (CDH) and manganese-dependent peroxidases (MnP) on the degradation of kraft pulp cellulolytic enzyme lignin (CEL) were investigated. Addition of CDH significantly increased the amount of water-soluble products reduced from CEL by MnP. CDH facilitated the reduction of the contents of methoxyl, carboxyl, phenolic hydroxyl and total hydroxyl groups of CEL by MnP. 1H-NMR analysis showed that addition of CDH also decreased further the amount of protons of CEL degraded by MnP. The results proved for the first time that CDH could promote degradation of lignin by MnP and suggest that CDH could not only promote degradation of cellulose but also is an important part of the lignin biodeg-radation system.展开更多
[Objective] The effects of yttrium nitrate （YNO3） on biomass and antioxi- dant systems of paddy rice （Yttrium （Y）; Oxidative stress; Dismutases （SOD）; Per- oxidases （POD）, Catalases （CAT）, Paddy rice （Trit...[Objective] The effects of yttrium nitrate （YNO3） on biomass and antioxi- dant systems of paddy rice （Yttrium （Y）; Oxidative stress; Dismutases （SOD）; Per- oxidases （POD）, Catalases （CAT）, Paddy rice （Triticum aestivum）） together with the occurrences of Y in soils were investigated to assess its ecotoxicological effects on plant. [Method]Y solutions with various concentrations were sprinkled on soil sam- ples, which were well mixed and then put into culture dishes to culture paddy rice seeds for further evaluation. [Result] The results indicated that 25-100 mg/kg Y treatments significantly increased the biomass （total weight, root weight, shoot weight and leaf weight）, chlorophyll （CHL） content and protein content of paddy rice, whereas 200-800 mg/kg Y treatments had a converse effect. Similarly, biomarker for the antioxidant systems including superoxide dismutases （SOD）, peroxidases （POD） and catalases （CAT） all exhibited similar trends in both shoots and roots of paddy rice. At the same time, the malonaldehyde （MDA） content increased at from 25 to 100 mg/kg and decreased with concentrations of Y from 100 to 800 mg/kg in both shoots and roots of paddy rice. This indicated that Y could stimulate the growth of plant at low concentration, but inhibit the growth at relatively high concen- tration. [Conclusion] The levels of Y were 641＋49, 328_＋16 and 473_＋40 mg/kg in soils collected from mining area, farmland and navel orange orchard respectively. The levels of Y in the investigated area were higher than the benefit level （100 mg/kg）, which could cause low biomass as well as low activity of SOD, POD and CAT in paddy rice. Therefore, a more careful use of Y is necessary in crop management.展开更多
Parkinson's disease is primarily caused by the loss of dopaminergic neurons in the substantia nigra compacta.Ferroptosis,a novel form of regulated cell death characterized by iron accumulation and lipid peroxidati...Parkinson's disease is primarily caused by the loss of dopaminergic neurons in the substantia nigra compacta.Ferroptosis,a novel form of regulated cell death characterized by iron accumulation and lipid peroxidation,plays a vital role in the death of dopaminergic neurons.However,the molecular mechanisms underlying ferroptosis in dopaminergic neurons have not yet been completely elucidated.NADPH oxidase 4 is related to oxidative stress,however,whether it regulates dopaminergic neuronal ferroptosis remains unknown.The aim of this study was to determine whether NADPH oxidase 4 is involved in dopaminergic neuronal ferroptosis,and if so,by what mechanism.We found that the transcriptional regulator activating transcription factor 3 increased NADPH oxidase 4 expression in dopaminergic neurons and astrocytes in an 1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine-induced Parkinson's disease model.NADPH oxidase 4 inhibition improved the behavioral impairments observed in the Parkinson's disease model animals and reduced the death of dopaminergic neurons.Moreover,NADPH oxidase 4 inhibition reduced lipid peroxidation and iron accumulation in the substantia nigra of the Parkinson's disease model animals.Mechanistically,we found that NADPH oxidase 4 interacted with activated protein kinase Cαto prevent ferroptosis of dopaminergic neurons.Furthermore,by lowering the astrocytic lipocalin-2 expression,NADPH oxidase 4 inhibition reduced 1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine-induced neuroinflammation.These findings demonstrate that NADPH oxidase 4 promotes ferroptosis of dopaminergic neurons and neuroinflammation,which contribute to dopaminergic neuron death,suggesting that NADPH oxidase 4 is a possible therapeutic target for Parkinson's disease.展开更多
Nitrogen(N)enrichment has resulted in widespread alteration of grassland ecosystem processes and functions mainly through disturbance in soil enzyme activities.However,we lack a comprehensive understanding of how N de...Nitrogen(N)enrichment has resulted in widespread alteration of grassland ecosystem processes and functions mainly through disturbance in soil enzyme activities.However,we lack a comprehensive understanding of how N deposition affects specific key soil enzymes that mediate plant-soil feedback of grassland.Here,with a meta-analysis on 1446 cases from field observations in China,we show that N deposition differently affects soil enzymes associated with soil biochemical processes.Specifically,N-promoted C,N,and P-acquiring hydrolase activities significantly increased by 8.73%,7.67%,and 8.69%,respectively,related to an increase in microbial-specific enzyme secretion.The increased relative N availability and soil acidification were two potential mechanisms accounting for the changes in soil enzyme activities with N enrichment.The mixed N addition in combination of NH_(4)NO_(3) and urea showed greater stimulation effect on soil enzyme activities.However,the high rate and long-term N addition tended to weaken the positive responses of soil C-,Nand P-acquiring hydrolase activities to N enrichment.Spatially increased mean annual precipitation and temperature primarily promoted the positive effects of N enrichment on N-and P-acquiring hydrolase activities,and the stimulation of C-and N-acquiring hydrolase activities by N enrichment was intensified with the increase in soil depth.Finally,multimodal inference showed that grassland type was the most important regulator of responses of microbial C,N,and P-acquiring hydrolase activities to N enrichment.This meta-analysis provides a comprehensive insight into understanding the key role of N enrichment in shaping soil enzyme activities of grassland ecosystems.展开更多
The current single-atom catalysts(SACs)for medicine still suffer from the limited active site density.Here,we develop a synthetic method capable of increasing both the metal loading and mass-specific activity of SACs ...The current single-atom catalysts(SACs)for medicine still suffer from the limited active site density.Here,we develop a synthetic method capable of increasing both the metal loading and mass-specific activity of SACs by exchanging zinc with iron.The constructed iron SACs(h^(3)-FNC)with a high metal loading of 6.27 wt%and an optimized adjacent Fe distance of~4 A exhibit excellent oxidase-like catalytic performance without significant activity decay after being stored for six months and promising antibacterial effects.Attractively,a“density effect”has been found at a high-enough metal doping amount,at which individual active sites become close enough to interact with each other and alter the electronic structure,resulting in significantly boosted intrinsic activity of single-atomic iron sites in h^(3)-FNCs by 2.3 times compared to low-and medium-loading SACs.Consequently,the overall catalytic activity of h^(3)-FNC is highly improved,with mass activity and metal mass-specific activity that are,respectively,66 and 315 times higher than those of commercial Pt/C.In addition,h^(3)-FNCs demonstrate efficiently enhanced capability in catalyzing oxygen reduction into superoxide anion(O_(2)·^(−))and glutathione(GSH)depletion.Both in vitro and in vivo assays demonstrate the superior antibacterial efficacy of h^(3)-FNCs in promoting wound healing.This work presents an intriguing activity-enhancement effect in catalysts and exhibits impressive therapeutic efficacy in combating bacterial infections.展开更多
[Objective]The aim of this study was to understand the role of polyamine oxidative degradation in the process of lettuce seed germination. [Method]After lettuce seed soaking treatments with aminoguanidine （AG,a speci...[Objective]The aim of this study was to understand the role of polyamine oxidative degradation in the process of lettuce seed germination. [Method]After lettuce seed soaking treatments with aminoguanidine （AG,a specific inhibitor of polyamine oxidases）,seed germination rate,activities of polyamine oxidase （PAO） and diamine oxidase （DAO）,change of endogenous polyamine and H2O2 content were determined. [Result]Compared with the control,AG treatment strongly inhibited the seed germination,which also had an extremely significant difference in seed germination rate after incubation for 12 h. During the seed germination,activities of PAO and DAO significantly changed,while their activities firstly increased and then decreased,then DAO and PAO reached peaks at 24 h and 48 h respectively. AG treatment was strongly inhibitory for activities of DAO and PAO,whose activities even disappeared after incubation with AG for 24 h and 36 h. During the seed germination,endogenous Put reduced sharply in the first 24 h,then reduced slowly in 24-60 h,while Spd decreased slowly in the early stage of germination,and then sharply declined after 48 h. However,Spm content was low but slightly increased,and the total polyamine gradually decreased. AG treatment could significantly increase endogenous polyamines,especially Put and Spd contents. During the seed germination,H2O2 content gradually increased,and had a peak from 36 to 48 h,then kept a high level at last. AG treatment could significantly reduce H2O2 content. [Conclusion]During the seed germination,the changes of endogenous polyamine and H2O2 content correspond with the changes of PAO and DAO activities,which indicate that there is an active polyamine metabolism of oxidative degradation during the lettuce seed germination.展开更多
The incomplete degradation of tumour cells by macrophages(Mϕ)is a contributing factor to tumour progression and metastasis,and the degradation function of Mϕis mediated through phagosomes and lysosomes.In our prelimin...The incomplete degradation of tumour cells by macrophages(Mϕ)is a contributing factor to tumour progression and metastasis,and the degradation function of Mϕis mediated through phagosomes and lysosomes.In our preliminary experiments,we found that overactivation of NADPH oxidase 2(NOX2)reduced the ability of Mϕto degrade engulfed tumour cells.Above this,we screened out liquiritin from Glycyrrhiza uralensis Fisch,which can significantly inhibit NOX2 activity and inhibit tumours,to elucidate that suppressing NOX2 can enhance the ability of Mϕto degrade tumour cells.We found that the tumour environment could activate the NOX2 activity in Mϕphagosomes,causing Mϕto produce excessive reactive oxygen species(ROS),thus prohibiting the formation of phagolysosomes before degradation.Conversely,inhibiting NOX2 in Mϕby liquiritin can reduce ROS and promote phagosome-lysosome fusion,therefore improving the enzymatic degradation of tumour cells after phagocytosis,and subsequently promote T cell activity by presenting antigens.We further confirmed that liquiritin down-regulated the expression of the NOX2 specific membrane component protein gp91 phox,blocking its binding to the NOX2 cytoplasmic component proteins p67 phox and p47 phox,thereby inhibiting the activity of NOX2.This study elucidates the specific mechanism by which Mϕcannot degrade tumour cells after phagocytosis,and indicates that liquiritin can promote the ability of Mϕto degrade tumour cells by suppressing NOX2.展开更多
Multiple phytohormones,including gibberellin(GA),abscisic acid(ABA),and indole-3-acetic acid(IAA),regulate seed germination.In this study,a barley aldehyde oxidase 1(HvAO1)gene was identified,which is located near the...Multiple phytohormones,including gibberellin(GA),abscisic acid(ABA),and indole-3-acetic acid(IAA),regulate seed germination.In this study,a barley aldehyde oxidase 1(HvAO1)gene was identified,which is located near the SD2(seed dormancy 2)region at the telomeric end of chromosome 5H.A doubledhaploid population(AC Metcalfe/Baudin)was used to characterize HvAO1 and validated its association with seed germination and malting quality.Aldehyde oxidase is predicted to catalyse the oxidation of various aldehydes,such as indoleacetaldehyde and abscisic aldehyde,into IAA and ABA,which is the final step of IAA/ABA biogenesis.This process influences the final IAA/ABA concentration in the seed,affecting the seed dormancy.Sequence analysis revealed substantial variations in the HvAO1 promoter regions between AC Metcalfe and Baudin.The combining seed germination tests,genetic variation analysis,gene expression,and phytohormone measurements showed that Baudin,which displays strong seed dormancy,has a specific sequence variation in the promoter region of the HvAO1 gene.This variation is associated with a higher expression level of the HvAO1 gene and an increased level of ABA than those in AC Metcalfe,which shows weak dormancy and lacks this sequence variation.In addition to its strong effect on the SD2 gene,HvAO1 shows excellent potential to fine-tune malting quality and seed dormancy,as evidenced by genotyping with HvAO1-specific markers,dormancy phenotypes,and malting quality.Our findings provide a new strategy for introducing favourable HvAO1 alleles to achieve the desired level of seed dormancy and high malting quality in barley.展开更多
Objective:To investigate the effects of a crude extract from Gnetum montanum Markgr.on ethanol-induced hepatotoxicity and metabolic disorders.Methods:Alcoholic liver disorder was induced in mice by administering incre...Objective:To investigate the effects of a crude extract from Gnetum montanum Markgr.on ethanol-induced hepatotoxicity and metabolic disorders.Methods:Alcoholic liver disorder was induced in mice by administering increasing doses of ethanol via oral gavage.Biomarkers of liver injury and oxidative stress were assessed at the end of the study.Liver tissue damage and fat deposition were evaluated using hematoxylin and eosin and oil red O staining,respectively.In addition,key biomarkers were examined in acetaldehyde-treated HepG2 cells.Results:Ethanol consumption induced characteristic pathological changes,including elevated serum markers of liver injury,hepatic lipid accumulation,and oxidative stress in liver tissues.Oral administration of Gnetum montanum extract(175 and 350 mg/kg)decreased serum aspartate aminotransferase,alanine aminotransferase,γ-glutamyl transferase,and bilirubin levels in ethanol-treated mice.The extract also lowered triglyceride levels in serum and liver tissue in a dose-dependent manner.Furthermore,it mitigated malondialdehyde levels,preserved reduced glutathione levels,and enhanced catalase activity and total antioxidant capacity in liver tissue homogenates.Additionally,ethanol-induced hyperuricemia was suppressed by Gnetum montanum extract by inhibiting xanthine oxidase activity.Similar effects were observed in Gnetum montanum extract-treated HepG2 cells.Conclusions:This study demonstrates that Gnetum montanum extract alleviates ethanol-induced hepatic injury by alleviating oxidative stress and inhibiting xanthine oxidase activity.展开更多
Carotenoids are the largest group of natural pigments responsible for the yellow,orange,and red colors in plant kernels,fruits,and leaves(Gupta and Hirschberg,2021).In plants,carotenoids are involved in manybiological...Carotenoids are the largest group of natural pigments responsible for the yellow,orange,and red colors in plant kernels,fruits,and leaves(Gupta and Hirschberg,2021).In plants,carotenoids are involved in manybiological processes,such as acting as accessory light-harvesting pigments in photosynthesis,participating in photoprotection,and serving as precursors for the hormones abscisic acid(ABA)and strigolactones(Ruiz-Sola and Rodriguez-Concepcion,2012).展开更多
文摘NAD(P)H oxidases were detected in suspension cultured cells of ginseng (Panax ginseng C. A. Meyer). The activities of these enzymes were induced by an elicitor (Cle) extracted from cell walls of Col-letotrichum lagerarium. In addition, Cle induced an oxidative burst and enhanced the synthesis of saponin, activity of phenylalanine ammonialyase (PAL) , accumulation of chalcone synthase (CHS) and the transcription of a hydroxyproline-rich glycoprotein gene ( hrgp ) . Pre-treatments with DPI and quinacrine (two inhibitors of mammalian neutrophil plasma membrane NADPH oxidase) for 30 min prior to Cle addition blocked the NAD(P)H oxidase activity induced by Cle. These inhibitors also inhibited the release of H2C2, the synthesis of saponin, PAL activity and CHS accumulation. Our data revealed homology between plasma membrane NAD(P)H oxidases of mammalian neutrophil cells and ginseng suspension cells. They also indicated that deactivated NAD(P)H oxidases catalysed the release of H2O2 and that H2O2 was functioning as a second messenger stimulating PAL activity, saponin synthesis and hrgp transcription. Elevations of Ca2 + and protein phos-phorylation/dephosphorylation were required for this defense process. We propose that NAD(P)H oxidases mediate the processes of Cle-induced defense responses in ginseng suspensions, and postulate the existence of a signalling cascade including extracellular Cle stimulation, activation of plasma membrane NAD(P)H oxidases, release of H2O2, and the intracellular responses of metabolism and gene transcription in ginseng suspension cells.
文摘In this study an effort has been made to use plant polyphenol oxidases; potato （Solanum tuberosum） and brinjal （Solanum melongena）, for the treatment of various important dyes used in textile and other industries. The ammonium sulphate fractionated enzyme preparations were used to treat a number of dyes under various experimental conditions. Majority of the treated dyes were maximally decolorized at pH 3.0. Some of the dyes were quickly decolorized whereas others were marginally decolorized. The initial first hour was sufficient for the maximum decolorization of dyes. The rate of decolorization was quite slow on long treatment of dyes. Enhancement in the dye decolorization was noticed on increasing the concentration of enzymes. The complex mixtures of dyes were treated with both preparations of polyphenol oxidases in the buffers of varying pH values. Potato polyphenol oxidase was significantly more effective in decolorizing the dyes to higher extent as compared to the enzyme obtained from brinjal polyphenol oxidase. Decolorization of dyes and their mixtures, followed by the formation of an insoluble precipitate, which could be easily removed simply by centrifugation.
基金supported by the National Natural Science Foundation of China (31972529, 31902184)the National Key Research and Development Projects (2017YFD0500500)the China Postdoctoral Science Foundation(2019M653774)。
文摘Background: Glucose oxidase(GOD), an aerobic dehydrogenase, has been used as an antibiotic substitute in feed.A study was conducted to evaluate the differential effects of 2 different GODs fermented by Aspergillus niger or Penicillium amagasakiense on caecal microbiota and to further illuminate the potential roles of changes in the gut microbiota in regulating the growth performance and meat quality of broiler chickens.Results: A total of 420 one-day-old healthy Arbor Acres broilers were randomly assigned to 4 treatments: the control group,the antibiotic growth promoter(AGP) supplementation group, and the GOD-A and GOD-P(GODs produced by A. niger and P. amagasakiense, respectively) groups. As a result, supplementation with GOD produced by P. amagasakiense could significantly improve the average daily weight gain and average daily feed intake of broilers before 21 days of age by significantly increasing the enzymatic activities of jejunal amylase and those of ileal amylase, chymotrypsin, and lipase in21-day-old broilers and could increase the enzymatic activities of duodenal amylase, jejunal amylase and lipase, and ileal chymotrypsin and lipase in 42-day-old broilers. Meanwhile, compared with AGP treatment, supplementation with GOD produced by P. amagasakiense significantly decreased the L value of 21-day-old broilers and the Δp H and L* value of 42-day-old broilers, while supplementation with GOD produced by A. niger significantly increased the p H24 hvalue of 21-day-old and 42-day-old broilers by reducing plasma malondialdehyde content. By using 16 S r RNA sequencing, we found that the beneficial bacteria and microbiota in broilers were not disturbed but were improved by GOD supplementation compared with ADP treatment, including the genera Eubacterium and Christensenel a and the species uncultured_Eubacterium_sp,Clostridium_asparagiforme, and uncultured_Christensenel a_sp, which were positively related to the improved intestinal digestive enzymatic activities, growth performance, and meat quality of broilers.Conclusion: The altered gut microbiota induced by supplementation with glucose oxidase produced by P. amagasakiense mediate better regulatory effects on the meat quality and growth performance of broilers than that induced by supplementation with glucose oxidase produced by A. niger.
文摘Aims: We focused on DNA methylation of the promoter regions of the Monoamine Oxidase (MAO) A and B genes from postmortem brains of subjects with schizophrenia. Methods: We determined levels of DNA methylation using genomic DNA samples purified from four brain areas: prefrontal cortex (PFC), hippocampus, occipital cortex and nucleus accumbens (NAc), by a bisulfite sequencing method from seven normal subjects and six subjects with schizophrenia. Results: Although very few methylated CpGs of the MAOA and MAOB genes were detected in male samples, various DNA methylation patterns were present in female samples, and some differences were found in such patterns between normal subjects and subjects with schizophrenia. In the PFC, the average level of methylation of both genes was significantly higher in subjects with schizophrenia than in normal subjects. The content of highly methylated alleles of the MAOA gene in the NAc was significantly associated with schizophrenia, with similar results obtained for the MAOB gene in both the NAc and PFC. Some CpG sites showed higher levels of methylation in schizophrenia than in normal subjects. Conclusions: Levels of methylation were quite high in NAc and PFC in female subjects with schizophrenia compared with those in female normal subjects.
文摘Age-related Ecto-Nicotinamide Adenine Dinucleotide Oxidase Disulfide Thiol Exchangers 3 (ENOX3) or age-related NADH oxidases (arNOX) are expressed at the cell surface as five members of the TM-9 superfamily, initially membrane anchored, all functionally similar, with the N-termini exposed at the cell’s exterior. ECTO-NOXes are cell surface proteins with both time-keeping CoQH2 [NAD(P)H] oxidase and protein disulfidethiol interchange activities. They are designated as ECTO-NOX proteins because of their localization on the outer surface of the plasma membrane and to distinguish them from the phox-NOXes of host defense. A ca. 30 kDa N-terminal fragment is cleaved and accumulates in body fluids (serum, saliva, urine, perspiration). arNOXes appear around age 30 and increase steadily thereafter. Reduced quinones, i.e., reduced coenzyme Q, of the plasma membrane are natural substrates. NAD(P)H is oxidized as an artificial substrate. In one phase of the arNOX cycle electrons are transferred to oxygen to generate superoxide. Substrates for the shed forms of arNOX appear to be proteins of body fluids. Circulating lipoproteins and skin matrix proteins emerge as potentially important health-related targets. Through oxidation of collagen, elastin and other proteins of the skin matrix, arNOXes are major contributors to skin aging through tyrosine and thiol oxidation and subsequent cross linking. The main destructive action of arNOX, however, may be to directly oxidize circulating lipoproteins. arNOX in the blood is structured as an integral component of the LDL particle through site-specific binding. As such, arNOXes are implicated as major risk factors for cardiovascular disease due to specific oxidation of LDLs. The superoxide produced and its conversion to hydrogen peroxide would be one part of the potentially destructive properties by contribution to lipid oxidation. Inhibition of arNOX proteins provides a rational basis for anti-aging interventions and their elimination as a major risk factor of atherogenesis.
基金supported by the National Key R&D Program of China(2022YFD1401000).
文摘Poplar canker,caused by the fungus Cytospora chrysosperma,results in tremendous losses in poplar plantations in China.Although NADPH oxidases(NOXs)play important roles in the development and pathogenicity of several pathogenic fungi,their roles in C.chrysosperma remain unclear.In this study,we characterized three NOX genes(CcNox1,CcNox2,and CcNoxR)in C.chrysosperma.All three genes were highly upregulated during poplar branch infection,and deletion of any of them severely reduced virulence on poplar branches.Furthermore,deletion of either CcNox1 or CcNoxR resulted in a significant increase in endogenous reactive oxygen species production in hyphae,enhanced influx of Ca^(2+),the disruption of redox homeostasis and compromised mitochondrial integrity.Moreover,biosynthesis and secretion of a known virulence factor oxalic acid was obviously defective and exogenous oxalic acid supplementation rescued the virulence of the mutants.Taken together,our findings reveal that NOXs play important roles in redox homeostasis,mitochondrial integrity and pathogenicity in C.chrysosperma.
基金supported by National Key Research and Development Program of China(no.2022YFC2105900).
文摘Recent advancements in data technology offer immense opportunities for the discovery and development of new enzymes for the green synthesis of chemicals.Current protein databases predominantly prioritize overall sequence matches.The multi-scale features underpinning catalytic mechanisms and processes,which are scat-tered across various data sources,have not been sufficiently integrated to be effectively utilized in enzyme mining.In this study,we developed a sequence-and taxonomic-feature evaluation driven workflow to discover enzymes that can be expressed in E.coli and catalyze chemical reactions in vitro,using alcohol oxidase(AOX)for demonstration,which catalyzes the conversion of methanol to formaldehyde.A dataset of 21 reported AOXs was used to construct sequence scoring rules based on features,including sequence length,structural motifs,catalytic-related residues,binding residues,and overall structure.These scoring rules were applied to filter the results from HMM-based searches,yielding 357 candidate sequences of eukaryotic origin,which were catego-rized into six classes at 85%sequence similarity.Experimental validation was conducted in two rounds on 31 selected sequences representing all classes.Among these selected sequences,19 were expressed as soluble proteins in E.coli,and 18 of these soluble proteins exhibited AOX activity,as predicted.Notably,the most active recombinant AOX exhibited an activity of 8.65±0.29 U/mg,approaching the highest activity of native eukaryotic enzymes.Compared to the established UniProt-annotation-based workflow,this feature-evaluation-based approach yielded a higher probability of highly active recombinant AOX(from 8.3%to 19.4%),demonstrating the efficiency and potential of this multi-dimensional feature evaluation method in accelerating the discovery of active enzymes.
基金supported by grants from the Guangxi Natural Science Foundation(2024GXNSFAA010150)the Guangdong Basic and Applied Basic Research Foundation(2022A1515111167).
文摘Background:A significant proportion of patients still cannot benefit from existing targeted therapies and immunotherapies,making the search for new treatment strategies extremely urgent.In this study,we combined integrate public data analysis with experimental validation to identify novel prognostic biomarkers and therapeutic targets for lung adenocarcinoma(LUAD).Methods:We analyzed RNA and protein databases to assess the expression levels of cytochrome C oxidase 5B(COX5B)in LUAD.Several computational algorithms were employed to investigate the relationship between COX5B and immune infiltration in LUAD.To further elucidate the role of COX5B in LUAD,we utilized multiple experimental approaches,including quantitative reverse transcription PCR assays,western blot,immunohistochemistry,electron microscopy,flow cytometry,and EdU proliferation assays.Results:We revealed that COX5B was significantly elevated in LUAD and positively correlated with poor prognosis of LUAD patients.Analysis of co-expression network indicated that COX5B may take part in the intracellular adenosine triphosphate(ATP)synthesis through the oxidative phosphorylation pathway.There was a negative correlation between COX5B expression and immune infiltration in LUAD.Furthermore,we validated that COX5B levels were significantly elevated in both LUAD tissues and cell lines.Specifically,immunohistochemistry(IHC)assays revealed a 2.32-fold increase of COX5B in tumor tissues compared to that in adjacent normal tissues(p=0.0044).Additionally,COX5B knockdown disrupted the redox homeostasis,ultimately suppressed the proliferation of LUAD cells.Subsequent investigations demonstrated that berberine effectively targeted COX5B,diminishing its protein expression and consequently inhibiting cell proliferation and tumor growth in LUAD.Conclusions:This study established that upregulated COX5B was positive associated with poor patient prognosis in LUAD,elucidating the mechanisms by which berberine targets COX5B to inhibit tumor growth,thereby providing a novel therapeutic target and strategy for the clinical management of LUAD.
基金This work was supported by the Ministry of Innovation,Science and Research the state of North Rhine-Westphalia,Germany within the framework of the NRW-Strategieprojekt BioSC(No.313/323-400-00213)together with the“European Regional Development Fund(EFRE)”,Project“Clus-ter Industrial Biotechnology(CLIB)Kompetenzzentrum Biotechnologie(CKB)”(34.EFRE-0300095/1703FI04)Financial support by the Scien-tific and Technological Research Council of Turkey(TUBITAK)2219-International Research Fellowship Programme for Saadet Alpdagtas is gratefully acknowledged.
文摘Copper-radical oxidases(CROs)catalyze the two-electron oxidation of a large number of primary alcohols includ-ing carbohydrates,polyols and benzylic alcohols as well as aldehydes and𝛼-hydroxy-carbonyl compounds while reducing molecular oxygen to hydrogen peroxide.Initially,CROs like galactose oxidase and glyoxal oxidase were identified only in fungal secretomes.Since the last decade,their representatives have also been identified in some bacteria.CROs are grouped in the AA5 family of“auxiliary activities”in the database of Carbohydrate-Active enzymes.Despite low overall sequence similarity and different substrate specificities,sequence alignments and the solved crystal structures revealed a conserved architecture of the active sites in all CROs,with a mononuclear copper ion coordinated to an axial tyrosine,two histidines,and a cross-linked cysteine-tyrosyl radical cofactor.This unique post-translationally modified protein cofactor has attracted much attention in the past,which resulted in a large number of reports that shed light on key steps of the catalytic cycle and physico-chemical properties of CROs.Thanks to their broad substrate spectrum accompanied by the only need for molecular oxygen for catal-ysis,CROs since recently experience a renaissance and have been applied in various biocatalytic processes.This review provides an overview of the structural features,catalytic mechanism and substrates of CROs,presents an update on the engineering of these enzymes to improve their expression in recombinant hosts and to enhance their activity,and describes their potential fields of biotechnological application.
基金This research was supported by the China National Funds for Innovative Research Groups(31721004)the key program of the Natural Science Foundation of China(NSFC)(32030091)+3 种基金the NSFC Youth Program(31901832)Youth Program for Natural Science Foundation of Jiangsu Province(BK2019054)the program of NSFC-DFG(31861133017)the NSFC program(32172377)。
文摘Apoplastic ascorbate oxidases(AOs)play a critical role in reactive oxygen species(RoS)-mediated innate host immunity by regulating the apoplast redox state.To date,little is known about how apoplastic effectors of the riceblast fungus Magnaportheoryzaemodulate the apoplast redox state of rice to subvert plant immunity.In this study,we demonstrated that M.oryzae MoAo1 is an Ao that plays a role in virulence by modulating the apoplast redox status of rice cells.We showed that MoAo1 inhibits the activity of rice OsAO3and OsAO4,which also regulate the apoplast redox status and plant immunity.In addition,we found that MoAo1,OsAO3,andOsAO4 allexhibit polymorphic variations whosevaried interactions orchestrate pathogen virulence and rice immunity.Taken together,our results reveal a critical role for extracellular redox enzymes during rice blast infection and shed light on the importance of the apoplast redox state anditsregulation inplant-pathogeninteractions.
基金This work was supported by the National Natural Science Foundation of China (Grant Nos. 20077015 and 29906005) by the Special Foundation of the Ministry of Education of China (Grant No. 200023).
文摘The synergistic effects of cellobiose dehydro-genase (CDH) and manganese-dependent peroxidases (MnP) on the degradation of kraft pulp cellulolytic enzyme lignin (CEL) were investigated. Addition of CDH significantly increased the amount of water-soluble products reduced from CEL by MnP. CDH facilitated the reduction of the contents of methoxyl, carboxyl, phenolic hydroxyl and total hydroxyl groups of CEL by MnP. 1H-NMR analysis showed that addition of CDH also decreased further the amount of protons of CEL degraded by MnP. The results proved for the first time that CDH could promote degradation of lignin by MnP and suggest that CDH could not only promote degradation of cellulose but also is an important part of the lignin biodeg-radation system.
基金Supported by the National Natural Science Foundation of China(21067003,51364015)the National High-Tech Research and Development Program of China(2012BAC11B07)the Jiangxi Natural Science Foundation(20114BAB203024)~~
文摘[Objective] The effects of yttrium nitrate （YNO3） on biomass and antioxi- dant systems of paddy rice （Yttrium （Y）; Oxidative stress; Dismutases （SOD）; Per- oxidases （POD）, Catalases （CAT）, Paddy rice （Triticum aestivum）） together with the occurrences of Y in soils were investigated to assess its ecotoxicological effects on plant. [Method]Y solutions with various concentrations were sprinkled on soil sam- ples, which were well mixed and then put into culture dishes to culture paddy rice seeds for further evaluation. [Result] The results indicated that 25-100 mg/kg Y treatments significantly increased the biomass （total weight, root weight, shoot weight and leaf weight）, chlorophyll （CHL） content and protein content of paddy rice, whereas 200-800 mg/kg Y treatments had a converse effect. Similarly, biomarker for the antioxidant systems including superoxide dismutases （SOD）, peroxidases （POD） and catalases （CAT） all exhibited similar trends in both shoots and roots of paddy rice. At the same time, the malonaldehyde （MDA） content increased at from 25 to 100 mg/kg and decreased with concentrations of Y from 100 to 800 mg/kg in both shoots and roots of paddy rice. This indicated that Y could stimulate the growth of plant at low concentration, but inhibit the growth at relatively high concen- tration. [Conclusion] The levels of Y were 641＋49, 328_＋16 and 473_＋40 mg/kg in soils collected from mining area, farmland and navel orange orchard respectively. The levels of Y in the investigated area were higher than the benefit level （100 mg/kg）, which could cause low biomass as well as low activity of SOD, POD and CAT in paddy rice. Therefore, a more careful use of Y is necessary in crop management.
基金supported by the National Natural Science Foundation of China,Nos.82271444(to JP),82271268(to BZ),and 82001346(to YL)the National Key Research and Development Program of China,No.2022YFE0210100(to BZ)。
文摘Parkinson's disease is primarily caused by the loss of dopaminergic neurons in the substantia nigra compacta.Ferroptosis,a novel form of regulated cell death characterized by iron accumulation and lipid peroxidation,plays a vital role in the death of dopaminergic neurons.However,the molecular mechanisms underlying ferroptosis in dopaminergic neurons have not yet been completely elucidated.NADPH oxidase 4 is related to oxidative stress,however,whether it regulates dopaminergic neuronal ferroptosis remains unknown.The aim of this study was to determine whether NADPH oxidase 4 is involved in dopaminergic neuronal ferroptosis,and if so,by what mechanism.We found that the transcriptional regulator activating transcription factor 3 increased NADPH oxidase 4 expression in dopaminergic neurons and astrocytes in an 1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine-induced Parkinson's disease model.NADPH oxidase 4 inhibition improved the behavioral impairments observed in the Parkinson's disease model animals and reduced the death of dopaminergic neurons.Moreover,NADPH oxidase 4 inhibition reduced lipid peroxidation and iron accumulation in the substantia nigra of the Parkinson's disease model animals.Mechanistically,we found that NADPH oxidase 4 interacted with activated protein kinase Cαto prevent ferroptosis of dopaminergic neurons.Furthermore,by lowering the astrocytic lipocalin-2 expression,NADPH oxidase 4 inhibition reduced 1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine-induced neuroinflammation.These findings demonstrate that NADPH oxidase 4 promotes ferroptosis of dopaminergic neurons and neuroinflammation,which contribute to dopaminergic neuron death,suggesting that NADPH oxidase 4 is a possible therapeutic target for Parkinson's disease.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA28110300)National Natural Science Foundation of China(No.U23A2004)+3 种基金Natural Science Foundation of Jilin Province,China(No.YDZJ202201ZYTS522)Science and Technology Cooperation Program between Jilin Province and Chinese Academy of Sciences(No.2023SYHZ0053)Innovation Team Program of Northeast Institute of Geography and Agroecology,Chinese Academy of Sciences(No.2023CXTD02)the European Commission under Marie Sk?odowska-Curie(No.101034371)。
文摘Nitrogen(N)enrichment has resulted in widespread alteration of grassland ecosystem processes and functions mainly through disturbance in soil enzyme activities.However,we lack a comprehensive understanding of how N deposition affects specific key soil enzymes that mediate plant-soil feedback of grassland.Here,with a meta-analysis on 1446 cases from field observations in China,we show that N deposition differently affects soil enzymes associated with soil biochemical processes.Specifically,N-promoted C,N,and P-acquiring hydrolase activities significantly increased by 8.73%,7.67%,and 8.69%,respectively,related to an increase in microbial-specific enzyme secretion.The increased relative N availability and soil acidification were two potential mechanisms accounting for the changes in soil enzyme activities with N enrichment.The mixed N addition in combination of NH_(4)NO_(3) and urea showed greater stimulation effect on soil enzyme activities.However,the high rate and long-term N addition tended to weaken the positive responses of soil C-,Nand P-acquiring hydrolase activities to N enrichment.Spatially increased mean annual precipitation and temperature primarily promoted the positive effects of N enrichment on N-and P-acquiring hydrolase activities,and the stimulation of C-and N-acquiring hydrolase activities by N enrichment was intensified with the increase in soil depth.Finally,multimodal inference showed that grassland type was the most important regulator of responses of microbial C,N,and P-acquiring hydrolase activities to N enrichment.This meta-analysis provides a comprehensive insight into understanding the key role of N enrichment in shaping soil enzyme activities of grassland ecosystems.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFB3804500)the National Natural Science Foundation of China(Grant No.52202352,22335006)+4 种基金the Shanghai Municipal Health Commission(Grant No.20224Y0010)the CAMS Innovation Fund for Medical Sciences(Grant No.2021-I2M-5-012)the Basic Research Program of Shanghai Municipal Government(Grant No.21JC1406000)the Fundamental Research Funds for the Central Universities(Grant No.22120230237,2023-3-YB-11,22120220618)the Basic Research Program of Shanghai Municipal Government(23DX1900200).
文摘The current single-atom catalysts(SACs)for medicine still suffer from the limited active site density.Here,we develop a synthetic method capable of increasing both the metal loading and mass-specific activity of SACs by exchanging zinc with iron.The constructed iron SACs(h^(3)-FNC)with a high metal loading of 6.27 wt%and an optimized adjacent Fe distance of~4 A exhibit excellent oxidase-like catalytic performance without significant activity decay after being stored for six months and promising antibacterial effects.Attractively,a“density effect”has been found at a high-enough metal doping amount,at which individual active sites become close enough to interact with each other and alter the electronic structure,resulting in significantly boosted intrinsic activity of single-atomic iron sites in h^(3)-FNCs by 2.3 times compared to low-and medium-loading SACs.Consequently,the overall catalytic activity of h^(3)-FNC is highly improved,with mass activity and metal mass-specific activity that are,respectively,66 and 315 times higher than those of commercial Pt/C.In addition,h^(3)-FNCs demonstrate efficiently enhanced capability in catalyzing oxygen reduction into superoxide anion(O_(2)·^(−))and glutathione(GSH)depletion.Both in vitro and in vivo assays demonstrate the superior antibacterial efficacy of h^(3)-FNCs in promoting wound healing.This work presents an intriguing activity-enhancement effect in catalysts and exhibits impressive therapeutic efficacy in combating bacterial infections.
基金Supported by Doctorate Fund of Suzhou University (13120740)~~
文摘[Objective]The aim of this study was to understand the role of polyamine oxidative degradation in the process of lettuce seed germination. [Method]After lettuce seed soaking treatments with aminoguanidine （AG,a specific inhibitor of polyamine oxidases）,seed germination rate,activities of polyamine oxidase （PAO） and diamine oxidase （DAO）,change of endogenous polyamine and H2O2 content were determined. [Result]Compared with the control,AG treatment strongly inhibited the seed germination,which also had an extremely significant difference in seed germination rate after incubation for 12 h. During the seed germination,activities of PAO and DAO significantly changed,while their activities firstly increased and then decreased,then DAO and PAO reached peaks at 24 h and 48 h respectively. AG treatment was strongly inhibitory for activities of DAO and PAO,whose activities even disappeared after incubation with AG for 24 h and 36 h. During the seed germination,endogenous Put reduced sharply in the first 24 h,then reduced slowly in 24-60 h,while Spd decreased slowly in the early stage of germination,and then sharply declined after 48 h. However,Spm content was low but slightly increased,and the total polyamine gradually decreased. AG treatment could significantly increase endogenous polyamines,especially Put and Spd contents. During the seed germination,H2O2 content gradually increased,and had a peak from 36 to 48 h,then kept a high level at last. AG treatment could significantly reduce H2O2 content. [Conclusion]During the seed germination,the changes of endogenous polyamine and H2O2 content correspond with the changes of PAO and DAO activities,which indicate that there is an active polyamine metabolism of oxidative degradation during the lettuce seed germination.
基金supported by National Natural Science Foundation of China(Grant No.:82074092)Natural Science Foundation of Guangdong Province,China(Grant No.:2023A1515011141)+1 种基金Research projects in Key Fields of Universities in Guangdong Province,China(Grant No.:2023ZDZX2020)Guangzhou Municipal Bureau of Science and Technology,China(Grant No.:202201011631).
文摘The incomplete degradation of tumour cells by macrophages(Mϕ)is a contributing factor to tumour progression and metastasis,and the degradation function of Mϕis mediated through phagosomes and lysosomes.In our preliminary experiments,we found that overactivation of NADPH oxidase 2(NOX2)reduced the ability of Mϕto degrade engulfed tumour cells.Above this,we screened out liquiritin from Glycyrrhiza uralensis Fisch,which can significantly inhibit NOX2 activity and inhibit tumours,to elucidate that suppressing NOX2 can enhance the ability of Mϕto degrade tumour cells.We found that the tumour environment could activate the NOX2 activity in Mϕphagosomes,causing Mϕto produce excessive reactive oxygen species(ROS),thus prohibiting the formation of phagolysosomes before degradation.Conversely,inhibiting NOX2 in Mϕby liquiritin can reduce ROS and promote phagosome-lysosome fusion,therefore improving the enzymatic degradation of tumour cells after phagocytosis,and subsequently promote T cell activity by presenting antigens.We further confirmed that liquiritin down-regulated the expression of the NOX2 specific membrane component protein gp91 phox,blocking its binding to the NOX2 cytoplasmic component proteins p67 phox and p47 phox,thereby inhibiting the activity of NOX2.This study elucidates the specific mechanism by which Mϕcannot degrade tumour cells after phagocytosis,and indicates that liquiritin can promote the ability of Mϕto degrade tumour cells by suppressing NOX2.
基金supported by the Engineering Research Center of Ecology and Agricultural Use of Wetland,Ministry of Education(KFT202302)the National Natural Science Foundation of China(32372052).
文摘Multiple phytohormones,including gibberellin(GA),abscisic acid(ABA),and indole-3-acetic acid(IAA),regulate seed germination.In this study,a barley aldehyde oxidase 1(HvAO1)gene was identified,which is located near the SD2(seed dormancy 2)region at the telomeric end of chromosome 5H.A doubledhaploid population(AC Metcalfe/Baudin)was used to characterize HvAO1 and validated its association with seed germination and malting quality.Aldehyde oxidase is predicted to catalyse the oxidation of various aldehydes,such as indoleacetaldehyde and abscisic aldehyde,into IAA and ABA,which is the final step of IAA/ABA biogenesis.This process influences the final IAA/ABA concentration in the seed,affecting the seed dormancy.Sequence analysis revealed substantial variations in the HvAO1 promoter regions between AC Metcalfe and Baudin.The combining seed germination tests,genetic variation analysis,gene expression,and phytohormone measurements showed that Baudin,which displays strong seed dormancy,has a specific sequence variation in the promoter region of the HvAO1 gene.This variation is associated with a higher expression level of the HvAO1 gene and an increased level of ABA than those in AC Metcalfe,which shows weak dormancy and lacks this sequence variation.In addition to its strong effect on the SD2 gene,HvAO1 shows excellent potential to fine-tune malting quality and seed dormancy,as evidenced by genotyping with HvAO1-specific markers,dormancy phenotypes,and malting quality.Our findings provide a new strategy for introducing favourable HvAO1 alleles to achieve the desired level of seed dormancy and high malting quality in barley.
基金funded by Vietnam National Foundation for Science and Technology Development under grant number 108.05-2023.23.
文摘Objective:To investigate the effects of a crude extract from Gnetum montanum Markgr.on ethanol-induced hepatotoxicity and metabolic disorders.Methods:Alcoholic liver disorder was induced in mice by administering increasing doses of ethanol via oral gavage.Biomarkers of liver injury and oxidative stress were assessed at the end of the study.Liver tissue damage and fat deposition were evaluated using hematoxylin and eosin and oil red O staining,respectively.In addition,key biomarkers were examined in acetaldehyde-treated HepG2 cells.Results:Ethanol consumption induced characteristic pathological changes,including elevated serum markers of liver injury,hepatic lipid accumulation,and oxidative stress in liver tissues.Oral administration of Gnetum montanum extract(175 and 350 mg/kg)decreased serum aspartate aminotransferase,alanine aminotransferase,γ-glutamyl transferase,and bilirubin levels in ethanol-treated mice.The extract also lowered triglyceride levels in serum and liver tissue in a dose-dependent manner.Furthermore,it mitigated malondialdehyde levels,preserved reduced glutathione levels,and enhanced catalase activity and total antioxidant capacity in liver tissue homogenates.Additionally,ethanol-induced hyperuricemia was suppressed by Gnetum montanum extract by inhibiting xanthine oxidase activity.Similar effects were observed in Gnetum montanum extract-treated HepG2 cells.Conclusions:This study demonstrates that Gnetum montanum extract alleviates ethanol-induced hepatic injury by alleviating oxidative stress and inhibiting xanthine oxidase activity.
基金supported by the National Key Research and Development Program of China(2022YFD1200704-3)Crop Varietal Improvement and Insect Pests Control by Nuclear Radiation,the Sichuan Province Science and Technology Program(2022NSFSC0018,2021YFYZ0011,2020YJ0249,MZGC20230108)the Biological Breeding Program of State Key of Sichuan Agricultural University(SKL-ZY202234).
文摘Carotenoids are the largest group of natural pigments responsible for the yellow,orange,and red colors in plant kernels,fruits,and leaves(Gupta and Hirschberg,2021).In plants,carotenoids are involved in manybiological processes,such as acting as accessory light-harvesting pigments in photosynthesis,participating in photoprotection,and serving as precursors for the hormones abscisic acid(ABA)and strigolactones(Ruiz-Sola and Rodriguez-Concepcion,2012).
