Quinone oxidoreductase 1 is overexpressed in gastric cancer and associated with outcome of adjuvant chemotherapy and survival

BACKGROUND Quinine oxidoreductase 1(NQO1)plays a vital role in protecting normal cells against oxidative damage and electrophilic attack.It is highly expressed in many solid tumors,suggesting a role in cancer development and progression.However,the role of NQO1 in gastric cancer and its effect on cancer development and prognosis have not been fully investigated.AIM To investigate the clinical relevance of NQO1 protein expression in gastric cancer and to explore the potential of NQO1 to serve as a prognostic biomarker and therapeutic target.METHODS In this retrospective study,gastric cancer specimens of 175 patients who were treated between 1995 and 2011 were subjected to immunohistochemistry analyses for NQO1.The correlation of NQO1 expression with gastric cancer prognosis and clinical and pathological parameters was investigated.RESULTS NQO1 protein was overexpressed in 59.43%(104/175)of the analyzed samples.Overexpression of NQO1 was associated with a significantly inferior prognosis.In addition,multivariate analysis suggested that NQO1 overexpression,along with tumor stage and patient age,are prominent prognostic biomarkers for gastric cancer.Moreover,NQO1 overexpression was correlated to a better response to 5-fluorouracil(5-FU)-based adjuvant chemotherapy.CONCLUSION NQO1 overexpression is associated with a significantly poor prognosis and better response to 5-FU in patients with gastric cancer.These findings are relevant for improving therapeutic approaches for gastric cancer patients.

Up-regulation of NAD(P)H quinone oxidoreductase 1 during human liver injury

AIM： To investigate the expression and activity of NAD（P）H quinone oxidoreductase 1 （NQO1） in human liver specimens obtained from patients with liver damage due to acetaminophen （APAP） overdose or primary biliary cirrhosis （PBC）. METHODS： NQOt activity was determined in cytosol from normal, APAP and PBC liver specimens. Western blot and immunohistochemical staining were used to determine patterns of NQO1 expression using a specific antibody against NQO1. RESULTS： NQO1 protein was very low in normal human livers. In both APAP and PBC livers, there was strong induction of NQO1 protein levels on Western blot. Correspondingly, significant up-regulation of enzyme activity （16- and 22-fold, P〈0.05） was also observed in APAP and PBC livers, respectively. Immunohistochemical analysis highlighted injury-specific patterns of NQO1 staining in both APAP and PBC livers. CONCLUSION： These data demonstrate that NQO1 protein and activity are markedly induced in human livers during both APAP overdose and PBC. Up-regulation of this cytoprotective enzyme may represent an adaptive stress response to limit further disease progression by detoxifying reactive species.

Subunit Arrangement of a 2-Ketoisovalerate Ferredoxin Oxidoreductase from Thermococcus profundus Revealed by a Low Resolution X-Ray Analysis

2-ketoisovalerate ferredoxin oxidoreductase (VOR) is a key enzyme in hyperthermophiles catalyzing the coenzyme A-dependent oxidative decarboxylation of aliphatic amino acid-derived 2-keto acids. The enzyme purified under anaerobic conditions from a hyperthermophilic archaeon, Thermococcus profundus, is a hetero-octamer (αβγδ)2 consisting of four different subunits, α = 45 kDa, β = 31 kDa, γ = 22 kDa and δ = 13 kDa, respectively, and it has three [4Fe-4S] clusters per αβγδ-protomer, similar to other ferredoxin oxidoreductases. In the present study, the native enzyme was purified from this strain and crystallized to give rod-like crystals that were suitable for X-ray diffraction experiments. The crystals belonged to space group P41212, with unit-cell parameters a = b = 136.20 ?, c = 221.07 ?. Diffraction images were processed to a resolution of 3.0 ?. The data collected so far indicate the approximate molecular boundaries and a partial main-chain trace of the enzyme.

Effect of Acetaldehyde on Oxidoreductases in Tissues of Rats at Different Ages

The toxicity of acetaldehyde and age related changes on oxidoreductases in the liver,brain, kidney, and musele of female albino rats (Wistar strain) were studied. The specific activities of lactate [LDH], isocitrate [ICDH (NAD/NADP)], succinate [SDH], malate [MDH], glutamate [GDH] and glucose-6-Phosphate [G-6-PDH] dehydrogenases were signifieantly inereased as a function of age. However, acetaldehyde treatment significantly inhibited oxidoreductases in the tissues of 21, 90 and 180 day old rats. Liver enzymes of young (21 days) rats exhibited greater sensitivity to acetaldehyde toxicity. Similar inhibition of oxidoreductases in brain and kidney of adult (180 days) rats treated with acetaldehyde was observed. LDH and GDH as compared to other enzymes studied showed higher susceptibility to acetaldehyde toxicity. The differential sensitivity of tissues and inhibition of oxidoreductases by acetaldehyde as a function of age could be attributed to hypoxic conditions, energy crisis, and mitochondrial structural changes. The results suggest that acetaldehyde affects oxidation of glucose via HMP shuni pathway, glycolytic pathway and Krebs cycle resulting in the impairment of carbohydrate metabolism

Probes and nano-delivery systems targeting NAD(P)H:quinone oxidoreductase 1:a mini-review

The two-electron cytoplasmic reductase NAD(P)H:quinone oxidoreductase 1 is expressed in many tissues.NAD(P)H:quinone oxidoreductase 1 is well-known for being highly expressed in most cancers.Therefore,it could be a target for cancer therapy.Because it is a quinone reductase,many bioimaging probes based on quinone structures target NAD(P)H:quinone oxidoreductase 1 to diagnose tumours.Its expression is higher in tumours than in normal tissues,and using target drugs such asβ-lapachone to reduce side effects in normal tissues can help.However,the physicochemical properties ofβlapachone limit its application.The problem can be solved by using nanosystems to deliverβ-lapachone.This minireview summarizes quinone-based fluorescent,nearinfrared and two-photon fluorescent probes,as well as nanosystems for delivering the NAD(P)H:quinone oxidoreductase 1-activating drugβ-lapachone.This review provides valuable information for the future development of probes and nano-delivery systems that target NAD(P)H:quinone oxidoreductase 1.

Insights into the catalytic mechanism of a type I sulfide quinone oxidoreductase(SQR)from Acidithiobacillus caldus

Acidithiobacillus caldus,a typical sulfur oxidizer,derives the majority of its energy from sulfur oxidation.And the essential enzyme for sulfide oxidation catalysis is sulfide quinone oxidoreductase(SQR),an ancient flavoprotein.Here,the catalytic mechanism of SQR generated from A.caldus was investigated(SQR^(Ac)).According to phylogenetic study,SQR^(Ac)(ACAty RS11315)is closely related to SQR(BAD99305)of Acidithiobacillus ferrooxidans NASF-1 and is classified as a type I Sqr enzyme.SQR^(Ac)heterologously produced in Escherichia coli exhibits the distinctive absorption peaks(375,450 nm)of the flavoproteins family of proteins in its absorption spectrum.Utilizing site-directed mutagenesis,the function of conserved cysteines in the catalytic pathway was determined.Based on the sulfide quinone redox reactions in vitro of SQR^(Ac)and variations,Cys160 and Cys356 have been identified as enzyme-active residues.Mutation of another cysteine present in all type I SQRs(Cys128)decreased enzyme activity by 56%,indicating that this residue plays an important but non-essential role in enzyme function.In addition,the binding affinities of SQR^(Ac),the visualization of its 3D structure,and the interaction between receptors and ligands were investigated.Finally,a suitable sulfide quinone redox catalytic mechanism for A.caldus was proposed.

NQO1 Mediates Lenvatinib Resistance by Regulating ROS-induced Apoptosis in Hepatocellular Carcinoma

Objective Hepatocellular carcinoma(HCC)is the third leading cause of cancer-associated death worldwide.As a first-line drug for advanced HCC treatment,lenvatinib faces a significant hurdle due to the development of both intrinsic and acquired resistance among patients,and the underlying mechanism remains largely unknown.The present study aims to identify the pivotal gene responsible for lenvatinib resistance in HCC,explore the potential molecular mechanism,and propose combinatorial therapeutic targets for HCC management.Methods Cell viability and colony formation assays were conducted to evaluate the sensitivity of cells to lenvatinib and dicoumarol.RNA-Seq was used to determine the differences in transcriptome between parental cells and lenvatinib-resistant(LR)cells.The upregulated genes were analyzed by GO and KEGG analyses.Then,qPCR and Western blotting were employed to determine the relative gene expression levels.Afterwards,the intracellular reactive oxygen species(ROS)and apoptosis were detected by flow cytometry.Results PLC-LR and Hep3B-LR were established.There was a total of 116 significantly upregulated genes common to both LR cell lines.The GO and KEGG analyses indicated that these genes were involved in oxidoreductase and dehydrogenase activities,and reactive oxygen species pathways.Notably,NAD(P)H:quinone oxidoreductase 1(NQO1)was highly expressed in LR cells,and was involved in the lenvatinib resistance.The high expression of NQO1 decreased the production of ROS induced by lenvatinib,and subsequently suppressed the apoptosis.The combination of lenvatinib and NQO1 inhibitor,dicoumarol,reversed the resistance of LR cells.Conclusion The high NQO1 expression in HCC cells impedes the lenvatinib-induced apoptosis by regulating the ROS levels,thereby promoting lenvatinib resistance in HCC cells.

Reaction mechanism of azoreductases suggests convergent evolution with quinone oxidoreductases

Azoreductases are involved in the bioremediation by bacteria of azo dyes found in waste water.In the gut flora,they activate azo pro-drugs,which are used for treatment of inflammatory bowel disease,releasing the active component 5-aminosalycilic acid.The bacterium P.aeruginosa has three azoreductase genes,paAzoR1,paAzoR2 and paAzoR3,which as recombinant enzymes have been shown to have different substrate specificities.The mechanism of azoreduction relies upon tautomerisation of the substrate to the hydrazone form.We report here the characterization of the P.aeruginosa azoreductase enzymes,including determining their thermostability,cofactor preference and kinetic constants against a range of their favoured substrates.The expression levels of these enzymes during growth of P.aeruginosa are altered by the presence of azo substrates.It is shown that enzymes that were originally described as azoreductases,are likely to act as NADH quinone oxidoreductases.The low sequence identities observed among NAD(P)H quinone oxidoreductase and azoreductase enzymes suggests convergent evolution.

Compound heterozygous variants in POR gene identified by whole-exome sequencing in a Chinese pedigree with cytochrome P450 oxidoreductase deficiency

Importance:Cytochrome P450 oxidoreductase deficiency (PORD) is a rare disease exhibiting a variety of clinical manifestations.This condition specifically leads to disordered steroidogenesis,which can affect the development of the reproductive system,skeleton,and other parts of the body.The severe form of PORD is difficult to differentiate with Antley-Bixler syndrome (ABS).The genetic characters and clinical evaluation of PORD are still unclear in China.Objective:To perform an exome analysis and identify the pathogenic cause in order to assist clinicians to obtain a proper evaluation on the genetic condition.Methods:The proband underwent detailed physical evaluations.DNA of the proband and his parents was isolated and whole-exome sequencing (WES) was performed.Variants were analyzed and evaluation according to the ACMG guideline.Results:A 1-year-old Chinese boy with midface hypoplasia,choanal stenosis,multiple joint contractures,micropenis and right cryptorchidism was misdiagnosed with Crouzon syndrome.By trio-whole-exome sequencing,we identified an unreported compound heterozygous mutation (c.667C＞T,p.R223* and c.1370G＞A,p.R457H) in POR in the proband.This mutation was inherited from healthy heterozygous parents,supporting the diagnosis of PORD,which was further confirmed by biochemical characteristics.Interpretation:We have identified a pathogenic variant with an unreported compound heterozygous POR mutation,which expands the clinical and genetic spectra of PORD and emphasizes the usefulness of WES for genetic diagnosis.

Arabidopsis tic62 trol Mutant Lacking Thylakoid- Bound Ferredoxin-NADP＋ Oxidoreductase Shows Distinct Metabolic Phenotype

Ferredoxin-NADP＋ oxidoreductase （FNR）, functioning in the last step of the photosynthetic electron transfer chain, exists both as a soluble protein in the chloroplast stroma and tightly attached to chloroplast membranes. Surface plasmon resonance assays showed that the two FNR isoforms, LFNR1 and LFNR2, are bound to the thylakoid membrane via the C-terminal domains of Tic62 and TROL proteins in a pH-dependent manner. The tic62 trol double mutants contained a reduced level of FNR, exclusively found in the soluble stroma. Although the mutant plants showed no visual phenotype or defects in the function of photosystems under any conditions studied, a low ratio of NADPH/NADP~ was detected. Since the CO2 fixation capacity did not differ between the tic62 trol plants and wild-type, it seems that the plants are able to funnel reducing power to most crucial reactions to ensure survival and fitness of the plants. However, the activity of malate dehydrogenase was down-regulated in the mutant plants. Apparently, the plastid metabolism is able to cope with substantial changes in directing the electrons from the light reactions to stromal metabolism and thus only few differences are visible in steady-state metabolite pool sizes of the tic62 trol plants.

cDNA cloning, functional expression and cellular localization of rat liver mitochondrial electron-transfer flavoprotein-ubiquinone oxidoreductase protein

A membrane-bound protein was purified from rat liver mitochondria.After being di-gested with V8 protease,two peptides containing identical 14 amino acid residue sequences were obtained.Using the 14 amino acid peptide derived DNA sequence as gene specific primer,the cDNA of correspondent gene 5′-terminal and 3′-terminal were obtained by RACE technique.The full-length cDNA that encoded a protein of 616 amino acids was thus cloned,which included the above mentioned peptide sequence.The full length cDNA was highly homologous to that of human ETF-QO,indicating that it may be the cDNA of rat ETF-QO.ETF-QO is an iron sulfur protein located in mitochondria inner membrane containing two kinds of redox center:FAD and[4Fe-4S]center.After comparing the sequence from the cDNA of the 616 amino acids protein with that of the mature protein of rat liver mitochondria,it was found that the N terminal 32 amino acid residues did not exist in the mature protein,indicating that the cDNA was that of ETF-QOp.When the cDNA was expressed in Saccharomyces cerevisiae with inducible vectors,the protein product was enriched in mitochondrial fraction and exhibited electron transfer activity(NBT re-ductase activity)of ETF-QO.Results demonstrated that the 32 amino acid peptide was a mito-chondrial targeting peptide,and both FAD and iron-sulfur cluster were inserted properly into the expressed ETF-QO.ETF-QO had a high level expression in rat heart,liver and kidney.The fu-sion protein of GFP-ETF-QO co-localized with mitochondria in COS-7 cells.

Analysis of the mechanism of aldo-keto reductase dependent cis-platin resistance in HepG2 cells based on transcriptomic and NADH metabolic state

Background:Aldo-keto oxidoreductase(AKR)inhibitors could reverse the resistance of several cancer cells to cis-platin,but their role in resistance remains unclear.Methods:We verified the difference of AKR1Cs expression by Western blot,RNA sequencing and qRT-PCR.The differences of AKR1Cs expression were analyzed and inferred.Use Assay of NADH and NAD^(+)content to verify the inference.The Docking experience was used to verify the affinity between MPA,MCFLA,MLS and AKR1C3.Results:Our RNA-seq results showed de novo NAD biosynthesis-related genes and NAD(P)H-dependent oxidoreductases were significantly upregulated in cis-platin-resistant HepG2 hepatic cancer cells(HepG2-RC cells)compared with HepG2 cells.At least 63 NAD(P)H-dependent reductase/oxidases were upregulated in HepG2-RC cells at least twofold.Knockdown of AKR1Cs could increase cis-platin sensitivity in HepG2-RC cells about two-fold.Interestingly,the AKR1C inhibitor meclofenamic acid could increase the cis-platin sensitivity of HepG2-RC cells about eight-fold,indicating that the knockdown of AKR1Cs only partially reversed the resistance.Meanwhile,the amount of total NAD and the ratio of NADH/NAD^(+)were increased in HepG2-RC cells compared with HepG2 cells.The ratio of NADH/NAD^(+)in HepG2-RC cells was almost seven-fold higher than in HepG2 or HL-7702 cells.Increased NADH expression could be explained as a directly operating antioxidant to scavenge cis-platin-induced radicals.Conclusion:We report here that NADH,which is produced by NAD(P)Hdependent oxidoreductases,plays a key role in the AKR-associated cis-platin resistance of HepG2 hepatic cancer cells.

4-Hydroxycinnamic acid attenuates neuronal cell death by inducing expression of plasma membrane redox enzymes and improving mitochondrial functions

Many approaches to neurodegenerative diseases that focus on amyloid-βclearance and gene therapy have not been successful.Some therapeutic applications focus on enhancing neuronal cell survival during the pathogenesis of neurodegenerative diseases,including mitochondrial dysfunction.Plasma membrane(PM)redox enzymes are crucial in maintaining cellular physiology and redox homeostasis in response to mitochondrial dysfunction.Neurohormetic phytochemicals are known to induce the expression of detoxifying enzymes under stress conditions.In this study,mechanisms of neuroprotective effects of 4-hydroxycinnamic acid(HCA)were examined by analyzing cell survival,levels of abnormal proteins,and mitochondrial functions in two different neuronal cells.HCA protected two neuronal cells exhibited high expression of PM redox enzymes and the consequent increase in the NAD^(+)/NADH ratio.Cells cultured with HCA showed delayed apoptosis and decreased oxidative/nitrative damage accompanied by decreased ROS production in the mitochondria.HCA increased the mitochondrial complexes I and II activities and ATP production.Also,HCA increased mitochondrial fusion and decreased mitochondrial fission.Overall,HCA maintains redox homeostasis and energy metabolism under oxidative/metabolic stress conditions.These findings suggest that HCA could be a promising therapeutic approach for neurodegenerative diseases.

Roles of MT-ND1 in Cancer

The energy shift toward glycolysis is one of the hallmarks of cancer.Complex I is a vital enzyme complex necessary for oxidative phosphorylation.The mitochondrially encoded NADH:ubiquinone oxidoreductase core subunit 1(MT-ND1)is the largest subunit coded by mitochondria of complex I.The present study summarizes the structure and biological function of MT-ND1.From databases and literature,the expressions and mutations of MT-ND1 in a variety of cancers have been reviewed.MT-ND1 may be a biomarker for cancer diagnosis and prognosis.It is also a potential target for cancer therapy.

Effect of miR-27b-3p and Nrf2 in human retinal pigment epithelial cell induced by high-glucose

AIM:To determine whether the microRNA-27b-3p(miR-27b-3p)/NF-E2-related factor 2(Nrf2)pathway plays a role in human retinal pigment epithelial(hRPE)cell response to high glucose,how miR-27b-3p and Nrf2 expression are regulated,and whether this pathway could be specifically targeted.METHODS:hRPE cells were cultured in normal glucose or high glucose for 1,3,or 6d before measuring cellular proliferation rates using cell counting kit-8 and reactive oxygen species(ROS)levels using a dihydroethidium kit.miR-27b-3p,Nrf2,NAD(P)H quinone oxidoreductase 1(NQO1)and heme oxygenase-1(HO-1)mRNA and protein levels were analyzed using reverse transcription quantitative polymerase chain reaction(RT-qPCR)and immunocytofluorescence(ICF),respectively.Western blot analyses were performed to determine nuclear and total Nrf2 protein levels.Nrf2,NQO1,and HO-1 expression levels by RT-qPCR,ICF,or Western blot were further tested after miR-27b-3p overexpression or inhibitor lentiviral transfection.Finally,the expression level of those target genes was analyzed after treating hRPE cells with pyridoxamine.RESULTS:Persistent exposure to high glucose gradually suppressed hRPE Nrf2,NQO1,and HO-1 mRNA and protein levels and increased miR-27b-3p mRNA levels.High glucose also promoted ROS release and inhibited cellular proliferation.Nrf2,NQO1,and HO-1 mRNA levels decreased after miR-27b-3p overexpression and,conversely,both mRNA and protein levels increased after expressing a miR-27b-3p inhibitor.After treating hRPE cells exposed to high glucose with pyridoxamine,ROS levels tended to decreased,proliferation rate increased,Nrf2,NQO1,and HO-1 mRNA and protein levels were upregulated,and miR-27b-3p mRNA levels were suppressed.CONCLUSION:Nrf2 is a downstream target of miR-27b-3p.Furthermore,the miR-27b-3p inhibitor pyridoxamine can alleviate high glucose injury by regulating the miR-27b-3p/Nrf2 axis.

The Chlorophyll Biosynthesis in Lotus Embryo Is Light-dependent

Angiosperms need light to synthesize chlorophyll, but lotus (Nelumbo nucifera Gaertn.) embryo was suspected to have the ability to form chlorophyll in the dark because lotus embryo can turn into green under the coverage of four layers of integuments (cotyledon, seed coat, pericarp, lotus pod) which were thought impossible for light to pass through. The authors excluded this possibility based on two experimental results: First, enclosing the young lotus pod with aluminium foil, the growth of louts embryo continued, but the chlorophyll formation was seriously inhibited. A lot of protochlorophyllide, chlorophyll precursor, were accumulated, most of which were combined with LPOR (light dependent protochlorophyllide oxidoreductase). Second, DPOR (dark or light-independent protochlorophyllide oxidoreductase) was the enzyme necessary for chlorophyll synthesis in the dark. The genes encoding DPOR were conservative in many species, but no homologues could be found in lotus genome. Taken together, authers' results clearly demonstrated that lotus embryo synthesizes chlorophyll only through the light-dependent pathway.

Key genes expression of reductive tricarboxylic acid cycle from deep-sea hydrothermal chemolithoautotrophic Caminibacter profundus in response to salinity, pH and O_2

CO2 fixation pathway of Caminibacter profundus, a chemolithoautotrophic e-Proteobacteria from deep-sea hydrothermal vent, was determined and characterized by genetic and enzymatic analyses. Gene expression of key enzymes for CO2 fixation in response to salinity, pH and O2 in Medium 829 were also investigated. The results demonstrate that C. profundus contained aclB, porA and oorA, the genes encoding key enzymes of reductive tricarboxylic acid （rTCA） cycle. However, genes fragments of cbbL and cbbMencoding key enzyme of Calvin cycle were not recovered. Key enzymatic activities of ATP citrate lyase （ACL）, pyruvate： ferredoxin oxidoreductase （POR） and 2-oxoglutarate： ferredoxin oxidoreductase （OOR） were also present in C. profun- dus. The combination of genetic and enzymatic analyses confirm that C. profundus adopted rTCA cycle for carbon assimilation. The results of aclB and oorA relative expressions of C. profundus demonstrate that the ranges of environmental factors for high genes expression were sea salt 3.0%-5.0% （optimum 3.0%）, pH 5.0-6.5（optimum pH 6.5）, anaerobic to microaerobic conditions （optimum 1.0% 02）. Gene expression pat- terns under different conditions show similar patterns with bacterial growth, revealing that key rTCA cycle genes provided molecular basis for bacterial growth and propagation. Our results suggest that C. profun- dus could regulate key genes of rTCA cycle for carbon assimilation and energy metabolism in response to environmental fluctuations in hydrothermal vent.

Effects of blueberry on hepatic fibrosis and transcription factor Nrf2 in rats

AIM:To investigate the effects of blueberry on hepatic fibrosis and NF-E2-related factor 2(Nrf2) transcription factor in rats.METHODS:Forty-five male Sprague-Dawley rats were randomly divided into control group(A);CCl4-induced hepatic fibrosis group(B);blueberry prevention group(C);Dan-shao-hua-xian capsule(DSHX) prevention group(D);and blueberry + DSHX prevention group(E).Liver fibrosis was induced in rats by subcutaneous injection of CCl4 and a high-lipid/low-protein diet for 8 wk(except the control group).The level of hyaluronic acid(HA) and alanine aminotransferase(ALT) in serum was examined.The activity of superoxide dismutase(SOD),glutathione-S-transferase(GST) and malondialdehyde(MDA) in liver homogenates was determined.The degree of hepatic fibrosis was evaluated by hematoxylin and eosin and Masson staining.Expression of Nrf2 and NADPH quinone oxidoreductase 1(Nqo1) was detected by real-time reversed transcribed-polymerase chain reaction,immunohistochemical techniques,and western blotting.RESULTS:Compared with group B,liver indices,levels of serum HA and ALT of groups C,D and E were reduced(liver indices:0.038 ± 0.008,0.036 ± 0.007,0.036 ± 0.005 vs 0.054 ± 0.009,P<0.05;HA:502.33 ± 110.57 ng/mL,524.25 ± 255.42 ng/mL,499.25 ± 198.10 ng/mL vs 828.50 ± 237.83 ng/mL,P<0.05;ALT:149.44 ± 16.51 U/L,136.88 ± 10.07 U/L,127.38 ± 11.03 U/L vs 203.25 ± 31.62 U/L,P<0.05),and SOD level was significantly higher,but MDA level was lower,in liver homogenates(SOD:1.36 ± 0.09 U/mg,1.42 ± 0.13 U/mg,1.50 ± 0.15 U/mg vs 1.08 ± 0.19 U/mg,P<0.05;MDA:0.294 ± 0.026 nmol/mg,0.285 ± 0.025 nmol/mg,0.284 ± 0.028 nmol/mg vs 0.335 ± 0.056 nmol/mg,P<0.05).Meanwhile,the stage of hepatic fibrosis was significantly weakened(P<0.05).Compared with group A,the activity of GST liver homogenates and expression levels of Nrf2 and Nqo1 in group B were elevated(P<0.05).The expression level of Nrf2 and Nqo1 in groups C,D,and E were increased as compared with group B,but the difference was not significant.CONCLUSION:Blueberry has preventive and protective effects on CCl4-induced hepatic fibrosis by reducing hepatocyte injury and lipid peroxidation.However,these effects may not be related to the activation of Nrf2 during long-term of CCl4.

Identification of Conserved Cotton MicroRNAs and Their Targets

No study has been performed on identifying microRNAs(miRNAs) and their targets in cotton although cotton is one of the most important fiber and economic crops around the world.In this study,

Implications of step-chilling on meat color investigated using proteome analysis of the sarcoplasmic protein fraction of beef longissimus lumborum muscle

In order to improve beef color and color stability, step-chilling （SC） was applied on excised bovine Iongissimus lumborum muscle, with chilling starting at 0-4℃ for 5 h, then holding the temperature at 12-18℃ for 6 h, followed by 0-4℃ again until 24 h post-mortem, pH and temperature were measured during rigor on SC loins as well as those subjected to routine chilling （RC, 0-4℃, till 24 h post-mortem）. Color L＊, a＊, b＊ values, metmyoglobin （MetMb） content, MetMb reducing ability （MRA） and NADH content were determined on samples aged for 1, 7, and 14 d. Sarcoplasmic proteome analysis was only conducted on d 1 samples. The results showed muscles subjected to SC maintained a temperature at around 15℃ for 5 to 10 h post-mortem, and exhibited a slow temperature decline, but rapid pH decline. Beef steaks treated with SC had higher L＊, a＊, b＊ and chroma values than those of RC samples at 1 and 7 d chilled storage （0-4℃）, while showing no significant difference for a＊, b＊ and chroma values at d 14. The SC samples also exhibited a lower relative content of surface MetMb, higher MRA and NADH content, compared with RC beef steaks during storage, indicating the SC-treated beef showed an improved color stability. Eleven differential protein spots/nine proteins were identified by two-dimensional gel electrophoresis and mass spectrometry, and those proteins were mainly involved in redox, chaperone binding, metabolic and peroxidase activity. Oxidoreductases play a role in decreasing the oxidation-induced myoglobin oxidation and benefiting the production of NADH, and finally improving the colour of beef. Of these, pyruvate dehydrogenase E1 component subunit beta showed a positive correlation with color L＊, a＊, b＊ values and accounted for more than 60% of the variation in color values; this protein can be considered as a potential beef color biomarker. The present study provided valuable information for studies on the molecular mechanism of color improvement from step-chilling, as well as for identifying markers associated with beef color.