Angiotensin-converting enzyme 2 alleviates liver fibrosis through the renin-angiotensin system

The present letter to the editor is related to the study titled‘Angiotensin-converting enzyme 2 improves liver fibrosis in mice by regulating autophagy of hepatic stellate cells’.Angiotensin-converting enzyme 2 can alleviate liver fibrosis by regulating autophagy of hepatic stellate cells and affecting the renin-angiotensin system.

Research on Oxidative Stress Induced by Tenuazonic Acid from Alternaria augustiovoide and Changes in Antioxidant Enzyme Activities in Leaves of Echinochloa crus-galli

[Objective] The aim of the study was to determine whether phytotoxicity of TeA against Echinochloa crus-galli leaves was correlated with oxidative stress caused by generation of reactive oxygen and the changes of antioxidant enzymes activity.[Method] The changes of malondialdehyde（MDA）content,hydrogen peroxide（H2O2）,and activities of superoxide dismutase（SOD）,glutathione reductase（GR）and catalase（CAT）were studied by leaf segment method in vitro.[Result] After the treatment of 500 μmol/L TeA,the content of MDA and H2O2 increased by 247.86% and 67.00%,respectively,indicating that the accumulation of MDA and H2O2 in E.crus-galli leaves was due to the reactive oxygen burst induced by TeA.TeA induced a significant increase in activities of SOD,GR and CAT.At 500 μmol/L TeA,activities of SOD,GR and CAT increased more than one fold compared with the control.[Conclusion] TeA could not only cause oxidative stress in leaves of E.crus-galli through the induction of reactive oxygen,but also induce the increasing of antioxidant enzyme activity.

Salvianolic acid B modulates the expression of drug-metabolizing enzymes in HepG2 cells

BACKGROUND: Enzymes involved in drug and xenobiotic metabolism have been considered to exist in two groups: phase I and phase II enzymes. Cytochrome P450 isoenzymes (CYPs) are the most important phase I enzymes in the metabolism of xenobiotics. The products of phase I metabolism are then acted upon by phase II enzymes, including glutathione S-transferases (GSTs). Herbs that inhibit CYPs such as CYP3A4 or that induce GSTs may have the potential to protect against chemical carcinogenesis since the mutagenic effects of carcinogens are often mediated through an excess of CYP-generated reactive intermediates. This study was designed to investigate the effects of salvianolic acid B (Sal B), a pure compound extracted from Radix Salviae Miltiorrhizae, a Chinese herb, on cell proliferation and CYP1A2 and CYP3A4 mRNA expression in the presence or absence of rifampicin, a potent inducer of CYPs and GST protein expression in HepG2 cells. METHODS: HepG2 cells were incubated with different concentrations of Sal B. Cell proliferation was determined by SYTOX-Green nucleic acid staining. CYP3A4 and CYP1A2 mRNA expression was assayed by real-time PCR. GST protein expression was analyzed by Western blotting. RESULTS: Low concentrations of Sal B (0-20 μmol/L) had no significant effects on cell proliferation, while higher concentrations (100-250 μmol/L) significantly inhibited proliferation in a concentration-dependent manner. Ten μmol/L Sal B, but not 1 μmol/L, down-regulated CYP3A4 and CYP1A2 mRNA expression after 24 hours of incubation, whereas both 1 and 10 μmol/L Sal B down-regulated CYP3A4mRNA expression after 96 hours of incubation; moreover, 1 and 10 μmol/L Sal B inhibited CYP3A4 mRNA expression induced by rifampicin. Both 1 μmol/L and 10 μmol/L Sal B increased GST expression. CONCLUSION: Sal B inhibits CYP3A4 and CYP1A2 mRNA expression and induces GST expression in HepG2 cells.

Bentonite-humic acid improves soil organic carbon,microbial biomass,enzyme activities and grain quality in a sandy soil cropped to maize(Zea mays L.) in a semi-arid region

A bentonite-humic acid(B-HA) mixture added to degraded soils may improve soil physical and hydraulic properties, due to effects such as improved soil structure and increased water and nutrient retention, but its effect on soil physicochemical and biological properties, and grain quality is largely unknown. The effect of B-HA, added at 30 Mg ha^(-1), was studied at 1,3, 5 and 7 years after its addition to a degraded sandy soil in a semi-arid region of China. The addition of B-HA significantly increased water-filled pore space and soil organic carbon, especially at 3 to 5 years after its soil addition to the soil. Amending the sandy soil with B-HA also increased the content of microbial biomass(MB)-carbon,-nitrogen and-phosphorus, and the activities of urease, invertase, catalase and alkaline phosphatase. The significant effect of maize(Zea mays L.) growth stage on soil MB and enzyme activities accounted for 58 and 84% of their total variation, respectively. In comparison, B-HA accounted for 8% of the total variability for each of the same two variables. B-HA significantly enhanced soil properties and the uptake of N and P by maize in semi-arid areas. The use of B-HA product would be an effective management strategy to reclaim degraded sandy soils and foster sustainable agriculture production in northeast China and regions of the world with similar soils and climate.

Salsola imbricata Forssk.ameliorates acetic acid-induced inflammatory bowel disease by modulating dysregulated antioxidant enzyme system and cytokine signaling pathways in mice

Objective:To explore the protective effect of the crude extract of Salsola imbricata against acetic acid-induced inflammatory bowel disease in mice and its mechanism of action.Methods:Ethanolic crude extract of Salsola imbricata was characterized by HPLC.Salsola imbricata extract at different doses was administered and ulcerative colitis was induced by 200μL,7.5%acetic acid and macroscopic parameters were evaluated to assess the homeostatic condition of intestinal mucosa along with hematological and biochemical assays.The levels of malondialdehyde,glutathione peroxidase 1,superoxide dismutase,and catalase were determined in colon tissues.Proinflammatory cytokines including interleukin(IL)-1β,IL-6,and tumor necrosis factor-α(TNF-α)were quantified by ELISA.The extent of tissue damage was assessed by histological analysis.Results:Phytochemical analysis confirmed the presence of phytochemicals including quercetin,gallic acid,syringic acid,benzoic acid and chlorogenic acid in the crude extract.The crude extract of Salsola imbricata(300 and 500 mg/kg)markedly decreased malondialdehyde and nitric oxide(P<0.01)and increased antioxidant activities of glutathione peroxidase 1(P<0.001)and superoxide dismutase(P<0.001).Moreover,it decreased the levels of IL-1β,IL-6 and TNF-αsignificantly(P<0.001)and reduced the damage to the colon mucosa,promoting tissue healing and regeneration.Conclusions:Salsola imbricata extract restores the colonic epithelial layers by maintaining mucosal homeostasis and cell integrity by modulating antioxidant defense system and inflammatory cytokine signaling in ulcerative colitis mice.

RAPID DETERMINATION OF L-GLUTAMIC ACID WITH AN ENZYME REACTOR OF L-GLUTAMIC DECARBOXYLASE IMMOBILIZED ON ION EXCHANGE RESIN

The preparation and characterization of an immobilized L-glutamic decarboxylase (GDC) were studied. This work is to develop a sensitive method for the determination of L-glutamate using a new biosensor, which consists of an enzyme column reactor of GDC immobilized on a novel ion exchange resin (carboxymethyl-copolymer of allyl dextran and N.N?methylene-bisacrylamide CM-CADB) and ion analyzer coupled with a CO2 electrode. The conditions for the enzyme immobilization were optimized by the parameters: buffer composition and concentration, adsorption equilibration time, amount of enzyme, temperature, ionic strength and pH. The properties of the immobilized enzyme on CM-CADB were studied by investigating the initial rate of the enzyme reaction, the effect of various parameters on the immobilized GDC activity and its stability. An immobilized GDC enzyme column reactor matched with a flow injection system-ion analyzer coupled with CO2 electrode-data collection system made up the original form of the apparatus of biosensor for determining of L-glutamate acid. The limit of detection is 1.0×10-5 M. The linearity response is in the range of 5×10 -2-5×10 -5 M . The equation of linear regression of the calibration curve is y= 43.3x + 181.6 (y is the milli-volt of electrical potential response, x is the logarithm of the concentration of the substrate of L-glutamate acid). The correlation coefficient equals 0.99. The coefficient of variation equals 2.7%.

Effect of Foliar Application of Amino Acid on the Quality and Enzyme Activity of Flowering Chinese Cabbage(Brassica parachinensis Bailey)

A pot experiment was conducted to study the influences of foliar application of glycine,alanine,lysine,and glutamic acid in 200 mg/kg or 500 mg/kg upon the quality and enzyme activity of flowering Chinese cabbage（Brassica parachinensis Bailey）.The results showed that all the application of these four amino acids could increase the yield of flowering Chinese cabbage,significantly raise the content of soluble sugar,and reduce the accumulation of nitrate.The applications of three other amino acids except alanine can increase the content of soluble proteins and decrease the accumulation of oxalic acid.However,the application of amino acid has insignificant influences on the SPAD number of chlorophyll,and causes the decrease of Vitamin C content.Meanwhile,the application of amino acid can improve the activity of nitrate reductase（NR） and glutamate dehydrogenase（GDH） as well.It shows that the application of amino acid is beneficial to improve ammonia metabolism,reduce the accumulation of nitrate and oxalic acid,increase the content of soluble sugar and soluble proteins,and improve the quality of flowering Chinese cabbage.

Effect of Calcium Cation on Thermophilic Acylamino Acid-releasing Enzyme Ape1547 from Aeropyrum pernix K1

The gene of enzyme（Ape1547） was cloned from hyperthermophilic archaeon Aeropyrum pernix K1 and expressed in Escherichia coil.The effect of calcium cation on the properties of Ape1547 was studied.Ape1547 exhibits both peptidase activity and esterase activity.The fluorescence spectrum shows that calcium cation quenches the fluorescence of the enzyme through static quenching mechanism,indicating that calcium cation was bound to the enzyme.Based on the study of calcium cation on CD ellipticity of Ape1547 by circular dichroism,we concluded that the change of enzyme structure induced by calcium cation may be responsible for the change of enzyme activity.Calcium cation has dual effects on Ape1547：it could activate the enzyme activity when its concentration was 0.1 mol/L,and the enzyme had the highest activity;however,when its concentration was higher than 0.2 mol/L,the enzyme activity was inhibited.The results indicate that the activity center of peptidase activity might involve more amino acid residues than that of esterase activity.

Effects of Exogenous Salicylic Acid Derivative on the Resistance to TMV and Activity of Defense Enzymes of Tobacco

[Objective] This study aimed to evaluate the effects of exogenous salicylic acid derivatives on tobacco resistance to TMV and activity of defense enzymes. [Method] The tobboco leaves were treated by exogenous salicylic acid derivatives. Then, the disease occurrence was observed, and the activity of phenylalanin ammo- nia lyase （PAL） and peroxidase （POX） were measured. [Result] Exogenous salicylic acid derivative increased the activities of PAL and POX, while did not influence the resistance to TMV. [Conclusion] The result provides a theoretical basis for the study of plant disease resistance mechanisms.

Novel 18β-glycyrrhetinic acid amide derivatives show dual-acting capabilities for controlling plant bacterial diseases through ROS-mediated antibacterial efficiency and activating plant defense responses

Natural products have long been a crucial source of,or provided inspiration for new agrochemical discovery.Naturally occurring 18β-glycyrrhetinic acid shows broad-spectrum bioactivities and is a potential skeleton for novel drug discovery.To extend the utility of 18β-glycyrrhetinic acid for agricultural uses,a series of novel 18β-glycyrrhetinic acid amide derivatives were prepared and evaluated for their antibacterial potency.Notably,compound 5k showed good antibacterial activity in vitro against Xanthomonas oryzae pv.oryzae(Xoo,EC50=3.64 mg L–1),and excellent protective activity(54.68%)against Xoo in vivo.Compound 5k induced excessive production and accumulation of reactive oxygen species in the tested pathogens,resulting in damaging the bacterial cell envelope.More interestingly,compound 5k could increase the activities of plant defense enzymes including catalase,superoxide dismutase,peroxidase,and phenylalanine ammonia lyase.Taken together,these enjoyable results suggested that designed compounds derived from 18β-glycyrrhetinic acid showed potential for controlling intractable plant bacterial diseases by disturbing the balance of the phytopathogen’s redox system and activating the plant defense system.

18β-glycyrrhetinic acid inhibits proliferation of gastric cancer cells through regulating the miR-345-5p/TGM2 signaling pathway

BACKGROUND Gastric cancer(GC)is a common gastrointestinal malignancy worldwide.Based on cancer-related mortality,the current prevention and treatment strategies for GC still show poor clinical results.Therefore,it is important to find effective drug treatment targets.AIM To explore the molecular mechanism of 18β-glycyrrhetinic acid(18β-GRA)regulating the miR-345-5p/TGM2 signaling pathway to inhibit the proliferation of GC cells.METHODS CCK-8 assay was used to determine the effect of 18β-GRA on the survival rate of GES-1 cells and AGS and HGC-27 cells.Cell cycle and apoptosis were detected by flow cytometry,cell migration was detected by a wound healing assay,the effect of 18β-GRA on subcutaneous tumor growth in BALB/c nude mice was investigated,and the cell autophagy level was determined by MDC staining.TMT proteomic analysis was used to detect the differentially expressed autophagy-related proteins in GC cells after 18β-GRA intervention,and then the protein-protein interaction was predicted using STRING(https://string-db.org/).MicroRNAs(miRNAs)transcriptome analysis was used to detect the miRNA differential expression profile,and use miRBase(https://www.mirbase/)and TargetScan(https://www.targetscan.org/)to predict the miRNA and complementary binding sites.Quantitative real-time polymerase chain reaction was used to detect the expression level of miRNA in 18β-GRA treated cells,and western blot was used to detect the expression of autophagy related proteins.Finally,the effect of miR-345-5p on GC cells was verified by mir-345-5p overexpression.RESULTS 18β-GRA could inhibit GC cells viability,promote cell apoptosis,block cell cycle,reduce cell wound healing ability,and inhibit the GC cells growth in vivo.MDC staining results showed that 18β-GRA could promote autophagy in GC cells.By TMT proteomic analysis and miRNAs transcriptome analysis,it was concluded that 18β-GRA could down-regulate TGM2 expression and up-regulate miR-345-5p expression in GC cells.Subsequently,we verified that TGM2 is the target of miR-345-5p,and that overexpression of miR-345-5p significantly inhibited the protein expression level of TGM2.Western blot showed that the expression of autophagy-related proteins of TGM2 and p62 was significantly reduced,and LC3II,ULK1 and AMPK expression was significantly increased in GC cells treated with 18β-GRA.Overexpression of miR-345-5p not only inhibited the expression of TGM2,but also inhibited the proliferation of GC cells by promoting cell apoptosis and arresting cell cycle.CONCLUSION 18β-GRA inhibits the proliferation of GC cells and promotes autophagy by regulating the miR-345-5p/TGM2 signaling pathway.

Chlorogenic acid alleviates hypoxic-ischemic brain injury in neonatal mice

Recent studies have shown that chlorogenic acid(CGA),which is present in coffee,has protective effects on the nervous system.However,its role in neonatal hypoxic-ischemic brain injury remains unclear.In this study,we established a newborn mouse model of hypoxic-ischemic brain injury using a modified Rice-Vannucci method and performed intraperitoneal injection of CGA.We found that CGA intervention effectively reduced the volume of cerebral infarct,alleviated cerebral edema,restored brain tissue structure after injury,and promoted axon growth in injured brain tissue.Moreover,CGA pretreatment alleviated oxygen-glucose deprivation damage of primary neurons and promoted neuron survival.In addition,changes in ferroptosis-related proteins caused by hypoxic-ischemic brain injury were partially reversed by CGA.Furthermore,CGA intervention upregulated the expression of the key ferroptosis factor glutathione peroxidase 4 and its upstream glutamate/cystine antiporter related factors SLC7A11 and SLC3A2.In summary,our findings reveal that CGA alleviates hypoxic-ischemic brain injury in neonatal mice by reducing ferroptosis,providing new ideas for the treatment of neonatal hypoxic-ischemic brain injury.

High Temperature at Grain-filling Stage Affects Nitrogen Metabolism Enzyme Activities in Grains and Grain Nutritional Quality in Rice

Rice plants would more frequently suffer from high temperature (HT) stress at the grain-filling stage in future. A japonica rice variety Koshihikari and an indica rice variety IR72 were used to study the effect of high temperature on dynamic changes of glutamine synthetase (GS) activity, glutamate synthase (GOGAT) activity, glutamic oxalo-acetic transminase (GOT) activity, glutamate pyruvate transminase (GPT) activity in grains and grain nutritional quality at the grain-filling stage. Under HT, the activities of GOGAT, GOT, GPT and soluble protein content in grains significantly increased, whereas GS activity significantly decreased at the grain-filling stage. In addition to the increase of protein and amino acids contents, it was suggested that GOGAT, GOT and GPT in grains played important roles in nitrogen metabolism at the grain-filling stage. Since the decrease of GS activity in grains did not influence the accumulations of amino acids and protein, it is implied that GS might not be the key enzyme in regulating glutamine content in grains.

Engineering the Biosynthesis of Caffeic Acid in Saccharomyces cerevisiae with Heterologous Enzyme Combinations

Engineering the biosynthesis of plant-derived natural products in microbes presents several challenges, especially when the expression and activation of the plant cytochrome P450 enzyme is required. By recruiting two enzymes—HpaB and HpaC—from several bacteria, we constructed functional 4- hydroxyphenylacetate 3-hydroxylase (4HPA3H) in Saccharomyces cerevisiae to take on a role similar to that of the plant-derived cytochrome P450 enzyme and produce caffeic acid. Along with a common tyrosine ammonia lyase (TAL), the different combinations of HpaB and HpaC presented varied capabilities in producing the target product, caffeic acid, from the substrate, L-tyrosine. The highest production of caffeic acid was obtained with the enzyme combination of HpaB from Pseudomonas aeruginosa and HpaC from Salmonella enterica, which yielded up to (289.4 ± 4.6) mg-L1 in shake-flask cultivation. The compatibility of heterologous enzymes within a yeast chassis was effectively improved, as the caffeic acid production was increased by 40 times from the initial yield. Six key amino acid residues around the flavin adenine dinucleotide (FAD) binding domain in HpaB from Pseudomonas aeruginosa were differentiate from those other HpaBs, and might play critical roles in affecting enzyme activity. We have thus established an effective approach to construct a highly efficient yeast system to synthesize non-native hydroxylated phenylpropanoids.

Reduction in Activity/Gene Expression of Anthocyanin Degradation Enzymes in Lychee Pericarp is Responsible for the Color Protection of the Fruit by Heat and Acid Treatment

Heat and acid treatments were reported to be a promising substitute for SO2 fumigation in color protection of postharvest lychee （Litchi chinensis） fruits, but the mechanism was not clear. In the present study, hot water （70℃） dipping followed by immersion in 2% HC1 （heat-acid） substantially protected the red color of the fruit during storage at 25℃ and inhibited anthocyanin degradation while hot water dipping alone （heat） led to rapidly browning and about 90% loss in anthocyanin content. The pH values in the pericarp of the heat-acid treated fruit dropped to 3.2, while the values maintained around 5.0 in the heat-treated and control fruit. No significantly different pH values were detected among the arils of heat-acid, heat treated and control fruit. Heat-acid treatment dramatically reduced the activities of anthocyanin degradation enzyme （ADE）, peroxidase （POD） and polyphenol oxidase in the pericarp. A marked reduction in LcPOD gene expression was also detected in heat-acid treated fruit, in contrast, induction was found in heat treated fruit. The pericarp of heat-acid treated fruit exhibited significantly lower respiration rate but faster water loss than that of the untreated or heat treated fruit. Taken together, heat treatment triggered quick browning and anthocyanin loss in lychee fruit, while heat-acid treatment protected the fruit color by a great reduction in the activities/gene expression of anthocyanin degradation enzymes and acidification of lychee pericarp.

Effects of Cinnamon Acid on Respiratory Rate and Its Related Enzymes Activity in Roots of Seedlings of Malus hupehensis Rehd.

This paper studied the effects of cinnamon acid treatments on the respiratory rate and related enzymes activity in the seedling roots of Malus hupehensis Rehd.It would provide information for understanding the mechanisms of inhibition damage caused by continuous cultivation of apple tree.20 mL of solution containing different concentrations of cinnamon acid was added into container with the tested seedlings.After treatment,the samples were taken periodically and the respiratory rates were measured by OXY-LAB oxygen electrodes under 25°C stable temperature and then the activities of related enzymes were measured.The rates of total respiration and other 2 pathways [tricarboxylic acid cycle （TCA） and pentose phosphate pathway （PPP）] appeared initially an increasing treads and late （on the 3rd d） began to decline.However,they again appeared an increase trend at the end period,on the contrast,the respiratory rate of embden-meyer- hot-parnas （EMP） pathway appeared a stead decline tread but it had a recover on the last day.The respiratory rate of total and 3 pathways were decreased under 125 mg kg-1 （soil）.The dynamic trends of the enzymes activities of pyrophosphate-dependent phosphofructokinase （PFK）,glucose-6-phosphate dehydrogenase （G-6-PDH） and malate dehydrogenase （MDH） showed similarly.In conclusion,treatments of certain concentration of cinnamon acid would inhibit the respiratory rate and related enzymes activity of roots of M.hupehensis Rehd.And the inhibition degrees were positively related with concentration of cinnamon acid treatments.

Higher Dietary Arachidonic Acid Levels Improved the Growth Performance, Gonad Development, Nutritional Value, and Antioxidant Enzyme Activities of Adult Sea Urchin(Strongylocentrotus intermedius)

The gonads of sea urchins(Strongylocentrotus intermedius) are characterized by high levels of arachidonic acid(ARA, 20:4 n-6) and eicosapentaenoic acid(EPA, 20:5 n-3). However, to our knowledge, little information is available regarding the physiological response of adult sea urchins to dietary ARA. In the present study, four dietary feeds were formulated with graded ARA(0, 0.5%, 1%, and 2% dry diet). Each diet was randomly allocated to three cages during a 56-day feeding experiment. The results showed that the sea urchin weight gain rate(WGR) and the gonadosomatic index(GI) significantly increased as ARA was equal to or above 1.0% of dry diet(P < 0.05). The activities of superoxide dismutase(SOD), catalase(CAT), and total anti-oxidative capacity(T-AOC) were the highest in the coelomic fluid of sea urchins that were fed diets with 1% ARA. The total essential amino acid(TEAA) and its ratio to total non-essential amino acid(TNEAA) showed a similar tendency to WGR and GI as dietary ARA increased, and the highest TEAA and TEAA/TNEAA were observed in the gonads of sea urchins that were fed diets with 1% ARA. Levels of ARA and ARA/EPA of the gonads increased while n-3/n-6 polyunsaturated fatty acid(PUFA) decreased with the increase of dietary ARA(P < 0.05). EPA in the gonads of experimental animals fed with formulated feeds showed no significant differences(P> 0.05), but was significantly lower than those fed with kelp(P < 0.05). These results suggested that relatively higher levels of ARA(1% dry diet) significantly promoted growth, gonad development, activities of antioxidant enzymes, as well as nutritional values(TEAA, TEAA/TNEAA, and PUFA) of adult S. intermedius.

Effects of Phenolic Acids on Growth and Activities of Membrane Protective Enzymes of Cucumber Seedlings

Two phenolic acids P-hydroxy benzoic acid and cinnamic acid were designated as four concentrations (0, 50 μmol/L, 100 μmol/L, 150 μmol/L) to investigate the effects of phenoic acids on the growth and the activities of membrane protective enzymes of cucumber seedlings. The results showed that both phenolic acids inhibited the seedlings growth. The inhibitory effects were increased with the concentration of phenolic acids increasing and the time of treatment prolonging. Seedlings treated with A150 (P-hydroxy benzoic acid, 150 μmol/L), B50 (cinnamic acid, 50 μmol/L), B100 (cinnamic acid, 100 μmol/L), B150 (cinnamic acid, 150 μmol/L) showed significantly shorter in plant height , smaller in leaf area. and lighter in fresh weight. The inhibitory effect of cinnamic acid was comparatively stronger than that of P-hydroxy benzoic acid. For protective enzymes system, compared to control , the POD activity increased at all concentrations of P-hydroxy benzoic acid during the treatment but increased at first then decreased before increased again at last at all concentrations of cinnamic acid .In the case of CAT, its activity increased at first, then decreased, and increased again at lower concentrations of phenolic acids. However, at higher concentrations the activities decreased at first, then increased a little, decreased continuously at last. In addition, the treatments of phenolic acids led to an increase then a decreaseof SOD activity and an increase of MDA content in the seedlings. All above indicated the accumulating of free radicalsand destruction of protective enzymes at higher concentrations of phenolic acids.

Elevated pancreatic enzymes, IgM, soluble interleukin-2 receptor in anti-GADab(+) type 1 diabetes

Type 1 diabetes can be classified into immune-mediated diabetes (type 1A) and idiopathic diabetes, which lacks immunological evidence for beta cell autoimmunity (type 1B). Type 1A diabetes is characterized by the presence of the anti-glutamic acid decarboxylase antibody (anti-GADab). Fulminant type 1 diabetes is classified as type 1B diabetes, and characterized by the absence of anti-GADab, flu-like symptoms, and elevated serum exocrine pancreatic enzymes. We report a type 1 diabetic patient who showed flu-like symptoms, elevated serum exocrine pancreatic enzymes, and an extremely high-titer of anti-GADab, manifesting the characteristics of both type 1A and fulminant type 1 diabetes.

In vitro cleavage of hepatitis B virus C mRNA by 10-23 DNA enzyme

BACKGROUND: 10-23 DNA enzyme is one kind of de-oxyribozymes for RNA cleavage. The inhibition effects of 10-23 DNA enzyme on the expression of the HBV C gene in HepG2. 2. 15 cells were demonstrated previously. The aim of this study was to further explore the cleavage activities of 10-23 DNA enzyme targeting at HBV C gene mRNA in vitro. METHODS: 10-23 DNA enzyme named Drz-HBV-C-9 specific to HBV C gene ORF A1816UG was designed and synthesized. HBV C gene mRNA was obtained by the in vitro transcription method. Cleavage activities of Drz-HBV-C-9 were observed in vitro. Values of kinetic parameters including Km,Kcat and Kcat/Km were calculated accordingly. RESULTS: Under the certain cleavage conditions, Drz-HBV-C-9 could efficiently cleave target mRNA at specific sites in vitro. Cleavage products of 109nt plus 191nt were obtained. The kinetic parameters, Km,Kcat and Kcat/ Km for Drz-HBV-C-9, were 1.4 ×10-9 mol, 1.6 min-1 and 1.1 × 109 mol-1 · min-1, respectively. CONCLUSIONS: 10-23 DNA enzyme targeting at HBV C gene mRNA possesses specific cleavage activities in vitro. This would be a potent antiviral strategy with respect to HBV gene therapy.