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 ...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.展开更多
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 ...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.展开更多
Gamma-aminobutyric acid(GABA)ergic neurons,the most abundant inhibitory neurons in the human brain,have been found to be reduced in many neurological disorders,including Alzheimer's disease and Alzheimer's dis...Gamma-aminobutyric acid(GABA)ergic neurons,the most abundant inhibitory neurons in the human brain,have been found to be reduced in many neurological disorders,including Alzheimer's disease and Alzheimer's disease-related dementia.Our previous study identified the upregulation of microRNA-502-3p(miR-502-3p)and downregulation of GABA type A receptor subunitα-1 in Alzheimer's disease synapses.This study investigated a new molecular relationship between miR-502-3p and GABAergic synapse function.In vitro studies were perfo rmed using the mouse hippocampal neuronal cell line HT22 and miR-502-3p agomiRs and antagomiRs.In silico analysis identified multiple binding sites of miR-502-3p at GABA type A receptor subunitα-1 mRNA.Luciferase assay confirmed that miR-502-3p targets the GABA type A receptor subunitα-1 gene and suppresses the luciferase activity.Furthermore,quantitative reve rse transcription-polymerase chain reaction,miRNA in situ hybridization,immunoblotting,and immunostaining analysis confirmed that overexpression of miR-502-3p reduced the GABA type A receptor subunitα-1 level,while suppression of miR-502-3p increased the level of GABA type A receptor subunitα-1 protein.Notably,as a result of the overexpression of miR-502-3p,cell viability was found to be reduced,and the population of necrotic cells was found to be increased.The whole cell patch-clamp analysis of human-GABA receptor A-α1/β3/γ2L human embryonic kidney(HEK)recombinant cell line also showed that overexpression of miR-502-3p reduced the GABA current and overall GABA function,suggesting a negative correlation between miR-502-3p levels and GABAergic synapse function.Additionally,the levels of proteins associated with Alzheimer s disease were high with miR-502-3p overexpression and reduced with miR-502-3p suppression.The present study provides insight into the molecular mechanism of regulation of GABAergic synapses by miR-502-3p.We propose that micro-RNA,in particular miR-502-3p,could be a potential therapeutic to rget to modulate GABAergic synapse function in neurological disorders,including Alzheimer's disease and Alzheimer's diseaserelated dementia.展开更多
BACKGROUND Gastric cancer(GC)is one of the most common cancer types worldwide,and its prevention and treatment methods have garnered much attention.As the active ingredient of licorice,18β-glycyrrhetinic acid(18β-GR...BACKGROUND Gastric cancer(GC)is one of the most common cancer types worldwide,and its prevention and treatment methods have garnered much attention.As the active ingredient of licorice,18β-glycyrrhetinic acid(18β-GRA)has a variety of pharmacological effects.The aim of this study was to explore the effective target of 18β-GRA in the treatment of GC,in order to provide effective ideas for the clinical prevention and treatment of GC.AIM To investigate the mechanism of 18β-GRA in inhibiting cell proliferation and promoting autophagy flux in GC cells.METHODS Whole transcriptomic analyses were used to analyze and screen differentially expressed microRNAs(miRNAs)in GC cells after 18β-GRA intervention.Lentivirus-transfected GC cells and the Cell Counting Kit-8 were used to detect cell proliferation ability,cell colony formation ability was detected by the clone formation assay,and flow cytometry was used to detect the cell cycle and apoptosis.A nude mouse transplantation tumor model of GC cells was constructed to verify the effect of miR-328-3p overexpression on the tumorigenicity of GC cells.Tumor tissue morphology was observed by hematoxylin and eosin staining,and microtubule-associated protein light chain 3(LC3)expression was detected by immunohistochemistry.TransmiR,STRING,and miRWalk databases were used to predict the relationship between miR-328-3p and signal transducer and activator of transcription 3(STAT3)-related information.Expression of STAT3 mRNA and miR-328-3p was detected by quantitative polymerase chain reaction(qPCR)and the expression levels of STAT3,phosphorylated STAT3(p-STAT3),and LC3 were detected by western blot analysis.The targeted relationship between miR-328-3p and STAT3 was detected using the dual-luciferase reporter gene system.AGS cells were infected with monomeric red fluorescent protein-green fluorescent protein-LC3 adenovirus double label.LC3 was labeled and autophagy flow was observed under a confocal laser microscope.RESULTS The expression of miR-328-3p was significantly upregulated after 18β-GRA intervention in AGS cells(P=4.51E-06).Overexpression of miR-328-3p inhibited GC cell proliferation and colony formation ability,arrested the cell cycle in the G0/G1 phase,promoted cell apoptosis,and inhibited the growth of subcutaneous tumors in BALB/c nude mice(P<0.01).No obvious necrosis was observed in the tumor tissue in the negative control group(no drug intervention or lentivirus transfection)and vector group(the blank vector for lentivirus transfection),and more cells were loose and necrotic in the miR-328-3p group.Bioinformatics tools predicted that miR-328-3p has a targeting relationship with STAT3,and STAT3 was closely related to autophagy markers such as p62.After overexpressing miR-328-3p,the expression level of STAT3 mRNA was significantly decreased(P<0.01)and p-STAT3 was downregulated(P<0.05).The dual-luciferase reporter gene assay showed that the luciferase activity of miR-328-3p and STAT33’untranslated regions of the wild-type reporter vector group was significantly decreased(P<0.001).Overexpressed miR-328-3p combined with bafilomycin A1(Baf A1)was used to detect the expression of LC3 II.Compared with the vector group,the expression level of LC3 II in the overexpressed miR-328-3p group was downregulated(P<0.05),and compared with the Baf A1 group,the expression level of LC3 II in the overexpressed miR-328-3p+Baf A1 group was upregulated(P<0.01).The expression of LC3 II was detected after intervention of 18β-GRA in GC cells,and the results were consistent with the results of miR-328-3p overexpression(P<0.05).Additional studies showed that 18β-GRA promoted autophagy flow by promoting autophagosome synthesis(P<0.001).qPCR showed that the expression of STAT3 mRNA was downregulated after drug intervention(P<0.05).Western blot analysis showed that the expression levels of STAT3 and p-STAT3 were significantly downregulated after drug intervention(P<0.05).CONCLUSION 18β-GRA promotes the synthesis of autophagosomes and inhibits GC cell proliferation by regulating the miR-328-3p/STAT3 signaling pathway.展开更多
α-Eleostearic acid and β-eleostearic acid formed vesicles in aqueous medium when an ethanol solution of eleostearic acid was injected rapidly into a vigorously vortexed aqueous phase. Formation of the vesicles was d...α-Eleostearic acid and β-eleostearic acid formed vesicles in aqueous medium when an ethanol solution of eleostearic acid was injected rapidly into a vigorously vortexed aqueous phase. Formation of the vesicles was demonstrated by electron microscopic observation and bromothymol blue encapsulation experiments. Polymerizations of the eleostearic acids in the formed vesicles carried out by UV irradiation produced poly-α-eleostearic acid and poly-β-eleostearic acid vesicles.展开更多
Activated carbons calcined at 400˚C and 600˚C (AC-400 and AC-600), prepared using palm nuts, collected in the town of Franceville in Gabon, were used to study the dynamic adsorption of MnO<sub>4</sub>-<...Activated carbons calcined at 400˚C and 600˚C (AC-400 and AC-600), prepared using palm nuts, collected in the town of Franceville in Gabon, were used to study the dynamic adsorption of MnO<sub>4</sub>-</sup> ions in acidic media on fixed bed column and on the kinetic modeling of experimental data of breakthrough curves of MnO<sub>4</sub>-</sup> ions obtained. Results on the adsorption of MnO<sub>4</sub>-</sup> ions in fixed-bed dynamics obtained on AC-400 and AC-600 adsorbents beds indicated that the AC-400 bed appears to be the most efficient in removing MnO<sub>4</sub>-</sup> ions in acidic media. Indeed, the adsorbed amounts, the adsorbed capacities at saturation and the elimination percentage of MnO<sub>4</sub>-</sup> ions obtained with AC-400 (31.24 mg;52.06 mg·g<sup>-1</sup> and 41.65% respectively) were higher compared to those obtained with AC-600 (9.87 mg;16.45 mg·g<sup>-1</sup> and 17.79% respectively). The breakthrough curves kinetic modeling revealed that the Thomas model and the pseudo-first-order kinetic model were the most suitable models to describe the adsorption of MnO<sub>4</sub>-</sup> ions on adsorbents studied in our experimental conditions. The results of the intraparticle diffusion model showed that intraparticle diffusion was involved in the adsorption mechanism of MnO<sub>4</sub>-</sup> ions on investigated adsorbents and was not the limiting step and the only process controlling MnO<sub>4</sub>-</sup> ions adsorption. In contrast to AC-400, the intraparticle diffusion on AC-600 bed plays an important role in the adsorption mechanism of MnO<sub>4</sub>-</sup> ions.展开更多
Aphids are major insect pests in agriculture and forestry worldwide.Following attacks by natural enemies,many aphids release an alarm pheromone to protect their population.In most aphids,the main component of the aphi...Aphids are major insect pests in agriculture and forestry worldwide.Following attacks by natural enemies,many aphids release an alarm pheromone to protect their population.In most aphids,the main component of the aphid alarm pheromone(AAP)is the sesquiterpene hydrocarbon(E)-β-farnesene(EβF).However,the mechanisms behind its biosynthesis and regulation remain poorly understood.In this study,we used the bird cherry–oat aphid Rhopalosiphum padi,which is an important wheat aphid,to investigate the regulatory mechanisms of EβF biosynthesis.Our results showed that EβF biosynthesis occurs during the mature embryo period and the molting period of the 1st-and 2nd-instar nymphs.Triglycerides provide the prerequisite material for EβF production and release.Based on transcriptome sequencing,RNAi analysis,hormone treatments,and quantitative measurements,we found that the biosynthesis of EβF utilizes acetyl coenzyme A produced from fatty acid degradation,which can be suppressed by juvenile hormone but it is promoted by 20-hydroxyecdysone through the modulation of fatty acid metabolism.This is the first systemic study on the modulation of EβF production in aphids.The results of our study provide insights into the molecular regulatory mechanisms of AAP biosynthesis,as well as valuable information for designing potential aphid control strategies.展开更多
Photoelectrochemical NO_(3)^(-)reduction(PEC NITRR)not only provides a promising solution for promoting the global nitrogen cycle,but also converts NO_(3)^(-)to the important chemicals(NH_(3)).However,it is still a gr...Photoelectrochemical NO_(3)^(-)reduction(PEC NITRR)not only provides a promising solution for promoting the global nitrogen cycle,but also converts NO_(3)^(-)to the important chemicals(NH_(3)).However,it is still a great challenge to prepare catalysts with excellent NO_(3)^(-)adsorption/activation capacity to achieve high NITRR.Herein,we designed a novel Fe^(2+)~Cu^(2+)Fe^(3+)LDH/BiVO_(4)(FCF-LDH/BVO)catalyst with synergistic effect of chemical adsorption and physical enrichment.Fe^(2+)in FCF-LDH/BVO provides the rich Lewis acid sites for the adsorption of NO_(3)^(-),and the appropriate layer spacing of FCF-LDH further promotes the physical enrichment of NO_(3)^(-)in its interior,thus realizing the effective contact between NO_(3)^(-)and active sites(Fe^(2+)).FCF-LDH/BVO showed excellent NH_(3)production performance(FE_(NH_(3))=66.1%,r_(NH_(3))=13.8μg h^(-1)cm^(-2))and selectivity(FE_(NO_(2)^(-))=2.5%,r_(NO_(2)^(-))=4.9μg h^(-1)cm^(-2))in 0.5 mol L^(-1)Na_(2)SO_(4)electrolyte.In addition,FCF-LDH/BVO maintains the desirable PEC stability for six cycle experiments,showing great potential for practical application.The^(14)NO_(3)^(-)and^(15)NO_(3)^(-)isotope test provides strong evidence for further verification of the origin of N in the generated NH_(3).This LDH catalyst has a great potential in PEC removal of NO_(3)^(-)from groundwater.展开更多
The different resistance of cotton (Gossypium hirsutum L.) cultivars to crude toxin of Verticillium dah/iae(VD) was correlated with the activities of chitinase and β-1, 3-glucanase in callus cells. The activities of ...The different resistance of cotton (Gossypium hirsutum L.) cultivars to crude toxin of Verticillium dah/iae(VD) was correlated with the activities of chitinase and β-1, 3-glucanase in callus cells. The activities of chitinase and β-1, 3-glucanase in the callus cells treated with the VD-toxin were increased to the higher level at earlier time point in resistant cultivars than these in the susceptible cultivars. Exogenous salicylic acid (SA) induced the accumulation of chitinase and β -1,3-glucanase, which resulted in the resistance of callus cells to the VD. toxin. Western blot using a polyclonal antibody against β -1,3-glucanase identified 28 kD protein that was induced by VD-toxin, SA, or VD-toxin plus SA.展开更多
BACKGROUND Disorders of primary bile acid synthesis may be life-threatening if undiagnosed,or not treated with primary bile acid replacement therapy. To date, there are few reports on the management and follow-up of p...BACKGROUND Disorders of primary bile acid synthesis may be life-threatening if undiagnosed,or not treated with primary bile acid replacement therapy. To date, there are few reports on the management and follow-up of patients with Δ4-3-oxosteroid 5β-reductase(AKR1 D1) deficiency. We hypothesized that a retrospective analysis of the responses to oral bile acid replacement therapy with chenodeoxycholic acid(CDCA) in patients with this bile acid synthesis disorder will increase our understanding of the disease progression and permit evaluation of this treatment regimen as an alternative to the Food and Drug Administration(FDA) approved drug cholic acid, which is currently unavailable in China.AIM To evaluate the therapeutic responses of patients with AKR1 D1 deficiency to oral bile acid therapy, specifically CDCA.METHODS Twelve patients with AKR1 D1 deficiency, confirmed by fast atom bombardment ionization-mass spectrometry analysis of urine and by gene sequencing for mutations in AKR1 D1, were treated with differing doses of CDCA or ursodeoxycholic acid(UDCA). The clinical and biochemical responses to therapy were monitored over a period ranging 0.5-6.4 years. Dose adjustment, to optimize the therapeutic dose, was based on changes in serum biochemistry parameters,notably liver function tests, and suppression of the urinary levels of atypical hepatotoxic 3-oxo-Δ4-bile acids measured by mass spectrometry.RESULTS Physical examination, serum biochemistry parameters, and sonographic findings improved in all 12 patients during bile acid therapy, except one who underwent liver transplantation. Urine bile acid analysis confirmed a significant reduction in atypical hepatotoxic 3-oxo-Δ4 bile acids concomitant with clinical and biochemical improvements in those patients treated with CDCA. UDCA was ineffective in down-regulating endogenous bile acid synthesis as evidenced from the inability to suppress the urinary excretion of atypical 3-oxo-Δ4-bile acids. The dose of CDCA required for optimal clinical and biochemical responses varied from 5.5-10 mg/kg per day among patients based on maximum suppression of the atypical bile acids and improvement in serum biochemistry parameters, and careful titration of the dose was necessary to avoid side effects from CDCA.CONCLUSION The primary bile acid CDCA is effective in treating AKR1 D1 deficiency but the therapeutic dose requires individualized optimization. UDCA is not recommended for long-term management.展开更多
By using acetonitrile as the sole nitrogen source, a microbial strain with high nitrilase activity, named as Alcaligenes sp. ECU0401, was newly isolated from soil, which could enantioselectively transform racemic mand...By using acetonitrile as the sole nitrogen source, a microbial strain with high nitrilase activity, named as Alcaligenes sp. ECU0401, was newly isolated from soil, which could enantioselectively transform racemic mandelonitrile into (R)-(?)-mandelic acid, with an enantiomeric excess of >99.9%.展开更多
A bacterium strain B26 capable of producing(R)-α-hydroxyphenylacetic acid [(R)-HPA](yield,47.5%;enantiomeric excess,99.1%) from phenylglyoxylic acid(PGA) with high optical purity was isolated and identified as Bacill...A bacterium strain B26 capable of producing(R)-α-hydroxyphenylacetic acid [(R)-HPA](yield,47.5%;enantiomeric excess,99.1%) from phenylglyoxylic acid(PGA) with high optical purity was isolated and identified as Bacillus sp.B26 by 16S rDNA(ribosomal DNA) sequencing.Phylogenic analysis showed that the strain was most similar to Bacillus sp.enrichment culture clone SYW5(FJ601635.1) and Bacillus cereus strain FM-4(EU794727.1).Efforts were made to further improve HPA-production and PGA-tolerance by UV irradiation and UV-LiCl cooperative mutagenesis.Among viable mutants,B.sp.UV-38 and B.sp.ULi-11 exhibited better productivities than the wild type.Comparisons of HPA production and time course among wild strain and two mutants showed that B.sp.ULi-11 was more competent than B.sp.UV-38.HPA production was increased by 39.1% with B.sp.ULi-11(yield,65.4%) compared to that with B.sp.B26(yield,47.0%) when cultured in fermentation broth(pH 7.2) at 32℃ with an agitation speed of 180 r·min-1 and PGA final concentration of 15 mmol·L-1 for 25 h.展开更多
Polyunsaturated fatty acids (PUFAs) are essential for normal growth in mammals, especially the ω-3 PUFAs, which play important roles in preventing several life-threatening diseases, such as coronary heart disease a...Polyunsaturated fatty acids (PUFAs) are essential for normal growth in mammals, especially the ω-3 PUFAs, which play important roles in preventing several life-threatening diseases, such as coronary heart disease and diabetes. In this study, we aimed to investigate whether the sFat-1 gene from Caenorhabditis briggsae could be functionally expressed in transgenic pigs, and whether the transgenic could synthesize high quality ω-3 PUFAs endogenously. In this study, a gene construct consisting of CMV promoter and 1.9 kb cDNA of ω-3 fatty acid desaturase gene (sFat-1) from C. briggsae was injected into the male pronucleus of pig embryos by microinjection. The piglets were screened for the transgene by PCR, Southern blot and reverse transcription-PCR analysis. Pigs that give positive results were mated with wild-type pigs to produce the next generation and the transmission of transgene was examined by PCR analysis. Fatty acids compositions of various tissues in the transgenic pigs were then analyzed by gas chromatograph. A total of 878 embryos were transferred into 42 recipients, among which 29 successfully got pregnant and gave birth to a total of 162 piglets, and 8 of them were identified to be transgenic. Fatty acid compositions in the transgenic pigs were altered, and the levels of ω-6:ω-3 ratios were decreased from 14.53 in the control to 2.62 in Fat-1 transgenic pigs. A number of primary sFat-1-transgenic pigs were bred in this study, which lays the foundation for cultivation of new varieties of transgenic pigs.展开更多
R2(4hydroxyphenoxy)propionic acid(RHPPA)is a key intermediate for the synthesis of classic herbicides with high selectivity against grassy weed.The main route for RHPPA biosynthesis is to hydroxylate the substrate R2p...R2(4hydroxyphenoxy)propionic acid(RHPPA)is a key intermediate for the synthesis of classic herbicides with high selectivity against grassy weed.The main route for RHPPA biosynthesis is to hydroxylate the substrate R2phenoxypropionic acid(RPPA)at C4 position with microbes.In order to provide sufficient RPPA for the industrial production of RHPPA,an effective RPPA synthesis method was established and optimized in this work.The synthesis process mainly consisted of two steps:(1)synthesis of S2chloropropionic acid from Lalanine via diazotization and chlorination reactions;and(2)synthesis of RPPA from S2chloropropionic acid and phenol via etherification reaction.The optimal reaction conditions were as follows:HCl:NaNO_(2):KI:LAla=2.0:1.2:0.7:1.0(in molar),125℃reflux for 1.5 h,with KI as catalyst,and KI:S2chloropropionic acid:phenol=0.075:1.2:1.0(in molar).Under these conditions,an improved molar conversion rate(74.9%,calculated in phenol)was achieved.After extraction using anionic exchange resin Amberlite IRA400(CI),RPPA product with a purity of 95.08%was obtained.The purified RPPA was identified and evaluated in the application of the biotransformative production of RHPPA.The results indicated that the synthesized RPPA supported the RHPPA biosynthesis with a comparable yield as that of the standard RPPA.The RPPA synthesis method provided herein exhibited the advantages of low price and easy availability of raw materials,less toxicity of reagents,simple manipulations,and low equipment/instrument requirements.展开更多
The kinetics of asymmetric production of R-(-)-mandelic acid (R-MA) from phenylglyoxylic acid (PGA) catalyzed by Saccharomyces cerevisiae sp. strain FD11b was studied by fed-batch cultures. The concentrations of...The kinetics of asymmetric production of R-(-)-mandelic acid (R-MA) from phenylglyoxylic acid (PGA) catalyzed by Saccharomyces cerevisiae sp. strain FD11b was studied by fed-batch cultures. The concentrations of glucose and PGA were controlled respectively with a dual feeding system. When the electron donor glucose was supplied at the rate of 0.0833mmol·gdw^-1·h^-1, the specific production rate (qp) and the enantiomeric excess of R-MA reached the maximum 0.353mmol·gdw^-1·h^-1 and 97.1%, respectively. The apparent reduction activity of yeast FD 11 b was obviously affected by both substrate PGA and product MA. The qp value reached the maximum 0.36-0.38mmol·gdw^-1·h^-1 when the PGA concentration was controlled between 25 and 35mmol·L^-1. The obvious substrate inhibition of bioconversion was observed at the PGA concentrations higher than 40mmol·L^-1. The accumulation of product MA also caused a severe feed-back inhibition for its production when the product concentration was above 60mmol·L^-1. The kinetic model with the inhibition effect of both substrate and product was simulated by a computer-based least-square arithrnatic. The established kinetic model was in good agreement with the experimental data.展开更多
Estrogen affects the generation and transmission of neuropathic pain,but the specific regulatory mechanism is still unclear.Activation of the N-methyl-D-aspartate acid receptor 1(NMDAR1) plays an important role in t...Estrogen affects the generation and transmission of neuropathic pain,but the specific regulatory mechanism is still unclear.Activation of the N-methyl-D-aspartate acid receptor 1(NMDAR1) plays an important role in the production and maintenance of hyperalgesia and allodynia.The present study was conducted to determine whether a relationship exists between estrogen and NMDAR1 in peripheral nerve pain.A chronic sciatic nerve constriction injury model of chronic neuropathic pain was established in rats.These rats were then subcutaneously injected with 17β-estradiol,the NMDAR1 antagonist D(-)-2-amino-5-phosphonopentanoic acid(AP-5),or both once daily for 15 days.Compared with injured drug na?ve rats,rats with chronic sciatic nerve injury that were administered estradiol showed a lower paw withdrawal mechanical threshold and a shorter paw withdrawal thermal latency,indicating increased sensitivity to mechanical and thermal pain.Estrogen administration was also associated with increased expression of NMDAR1 immunoreactivity(as assessed by immunohistochemistry) and protein(as determined by western blot assay) in spinal dorsal root ganglia.This 17β-estradiol-induced increase in NMDAR1 expression was blocked by co-administration with AP-5,whereas AP-5 alone did not affect NMDAR1 expression.These results suggest that 17β-estradiol administration significantly reduced mechanical and thermal pain thresholds in rats with chronic constriction of the sciatic nerve,and that the mechanism for this increased sensitivity may be related to the upregulation of NMDAR1 expression in dorsal root ganglia.展开更多
We herein report two crystals based on 2-(imidazo[1,2-a]pyridin-2-yl)-2-oxoacetic acid rad- ical and its perchlorate, and investigate the relationship between magnetic properties and crystal stacking structures or s...We herein report two crystals based on 2-(imidazo[1,2-a]pyridin-2-yl)-2-oxoacetic acid rad- ical and its perchlorate, and investigate the relationship between magnetic properties and crystal stacking structures or supramolecular interactions. 2-(imidazo[1,2-a]pyridin-2-yl)- 2-oxoaeetic acid radical in two crystals mainly exist as diamagnetic dimer formed via short atomic contacts or supramolecular interactions (hydrogen bonds, anion-Tr or lone- pair-~r interactions), leading to low magnetic susceptibilities. 2-(imidazo[1,2-a]pyridin-2-yl)- 2-oxoaeetic acid radical crystal exhibits quasi-one-dimensional columnar stacking chain and weak antiferromagnetism. However, its perchlorate crystal possesses one-dimensional double- stranded chain structure assembled through double hydrogen bonds and anion-To interactions, and reveals weak ferromagnetism.展开更多
AIM: To assess the value of long-chain w-3 fatty acids (FAs) supplementation in addition to amino-salicylic-acid (5-ASA) in pediatric patients with Crohn's disease (CD). METHODS: Thirty-eight patients (20 ma...AIM: To assess the value of long-chain w-3 fatty acids (FAs) supplementation in addition to amino-salicylic-acid (5-ASA) in pediatric patients with Crohn's disease (CD). METHODS: Thirty-eight patients (20 males and 18 females, mean age 10.13 years, range 5-16 years) with CD in remission were randomized into two groups and treated for 12 too. Group Ⅰ (18 patients) received 5-ASA (50 mg/kg/d)+w-3 FAs as triglycerides in gastroresistant capsules, 3 g/d (eicosapentanoic acid, EPA, 400 mg/g, docosahexaenoic acid, DHA, 200 mg/g). Group Ⅱ (20 patients) received 5-ASA (50 mg/kg/d)+olive oil placebo capsules. Patients were evaluated for fatty acid incorporation in red blood cell membranes by gas chromatography at baseline 6 and 12 mo after the treatment. RESULTS: The number of patients who relapsed at 1 year was significantly lower in group I than in group Ⅱ (P〈0.001). Patients in group I had a significant increase in the incorporation of EPA and DHA (P〈0.001) and a decrease in the presence of arachidonic acids. CONCLUSION: Enteric-coated w-3 FAs in addition to treatment with 5-ASA are effective in maintaining remission of pediatric CD.展开更多
AIM To determine the effects of ω-3 fatty acids(ω-3FA) on the toll-like receptor 4(TLR4)/nuclear factor κB p56(NF-κBp56) signal pathway in the lungs of rats with severe acute pancreatitis(SAP).METHODS A total of 5...AIM To determine the effects of ω-3 fatty acids(ω-3FA) on the toll-like receptor 4(TLR4)/nuclear factor κB p56(NF-κBp56) signal pathway in the lungs of rats with severe acute pancreatitis(SAP).METHODS A total of 56 Sprague-Dawley rats were randomly divided into 4 groups: control group, SAP-saline group, SAP-soybean oil group and SAP-ω-3FA group. SAP was induced by the retrograde infusion of sodium taurocholate into the pancreatic duct. The expression of TLR4 and NF-κBp56 in the lungs was evaluated by immunohistochemistry and Western blot analysis. The levels of inflammatory cytokines interleukin-6 and tumor necrosis factor-alpha in the lungs were measured by enzyme-linked immunosorbent assay. RESULTS The expression of TLR4 and NF-κBp56 in lungs and of inflammatory cytokines in serum significantly increased in the SAP group compared with the control group(P < 0.05), but was significantly decreased in the ω-3FA group compared with the soybean oil group at 12 and 24 h(P < 0.05).CONCLUSION During the initial stage of SAP, ω-3FA can efficiently lower the inflammatory response and reduce lung injury by triggering the TLR4/NF-κBp56 signal pathway.展开更多
基金Supported by the Ningxia Natural Science Foundation,No.2022AAC03144.
文摘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.
基金supported by the National Natural Science Foundation of China,No.81971425the Natural Science Foundation of Zhejiang Province,No.LY20H040002(both to XQF).
文摘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.
基金supported by the National Institute on Aging (NIA)National Institutes of Health (NIH)+3 种基金Nos.K99AG065645,R00AG065645R00AG065645-04S1 (to SK)NIH research grants,NINDS,No.R01 NS115834NINDS/NIA,No.R01 NS115834-02S1 (to LG)。
文摘Gamma-aminobutyric acid(GABA)ergic neurons,the most abundant inhibitory neurons in the human brain,have been found to be reduced in many neurological disorders,including Alzheimer's disease and Alzheimer's disease-related dementia.Our previous study identified the upregulation of microRNA-502-3p(miR-502-3p)and downregulation of GABA type A receptor subunitα-1 in Alzheimer's disease synapses.This study investigated a new molecular relationship between miR-502-3p and GABAergic synapse function.In vitro studies were perfo rmed using the mouse hippocampal neuronal cell line HT22 and miR-502-3p agomiRs and antagomiRs.In silico analysis identified multiple binding sites of miR-502-3p at GABA type A receptor subunitα-1 mRNA.Luciferase assay confirmed that miR-502-3p targets the GABA type A receptor subunitα-1 gene and suppresses the luciferase activity.Furthermore,quantitative reve rse transcription-polymerase chain reaction,miRNA in situ hybridization,immunoblotting,and immunostaining analysis confirmed that overexpression of miR-502-3p reduced the GABA type A receptor subunitα-1 level,while suppression of miR-502-3p increased the level of GABA type A receptor subunitα-1 protein.Notably,as a result of the overexpression of miR-502-3p,cell viability was found to be reduced,and the population of necrotic cells was found to be increased.The whole cell patch-clamp analysis of human-GABA receptor A-α1/β3/γ2L human embryonic kidney(HEK)recombinant cell line also showed that overexpression of miR-502-3p reduced the GABA current and overall GABA function,suggesting a negative correlation between miR-502-3p levels and GABAergic synapse function.Additionally,the levels of proteins associated with Alzheimer s disease were high with miR-502-3p overexpression and reduced with miR-502-3p suppression.The present study provides insight into the molecular mechanism of regulation of GABAergic synapses by miR-502-3p.We propose that micro-RNA,in particular miR-502-3p,could be a potential therapeutic to rget to modulate GABAergic synapse function in neurological disorders,including Alzheimer's disease and Alzheimer's diseaserelated dementia.
基金Ningxia Medical University Project,No. XZ2021005Ningxia Natural Science Foundation,Nos. 2022AAC03144 and 2022AAC02039National Natural Science Foundation of China,No. 82260879
文摘BACKGROUND Gastric cancer(GC)is one of the most common cancer types worldwide,and its prevention and treatment methods have garnered much attention.As the active ingredient of licorice,18β-glycyrrhetinic acid(18β-GRA)has a variety of pharmacological effects.The aim of this study was to explore the effective target of 18β-GRA in the treatment of GC,in order to provide effective ideas for the clinical prevention and treatment of GC.AIM To investigate the mechanism of 18β-GRA in inhibiting cell proliferation and promoting autophagy flux in GC cells.METHODS Whole transcriptomic analyses were used to analyze and screen differentially expressed microRNAs(miRNAs)in GC cells after 18β-GRA intervention.Lentivirus-transfected GC cells and the Cell Counting Kit-8 were used to detect cell proliferation ability,cell colony formation ability was detected by the clone formation assay,and flow cytometry was used to detect the cell cycle and apoptosis.A nude mouse transplantation tumor model of GC cells was constructed to verify the effect of miR-328-3p overexpression on the tumorigenicity of GC cells.Tumor tissue morphology was observed by hematoxylin and eosin staining,and microtubule-associated protein light chain 3(LC3)expression was detected by immunohistochemistry.TransmiR,STRING,and miRWalk databases were used to predict the relationship between miR-328-3p and signal transducer and activator of transcription 3(STAT3)-related information.Expression of STAT3 mRNA and miR-328-3p was detected by quantitative polymerase chain reaction(qPCR)and the expression levels of STAT3,phosphorylated STAT3(p-STAT3),and LC3 were detected by western blot analysis.The targeted relationship between miR-328-3p and STAT3 was detected using the dual-luciferase reporter gene system.AGS cells were infected with monomeric red fluorescent protein-green fluorescent protein-LC3 adenovirus double label.LC3 was labeled and autophagy flow was observed under a confocal laser microscope.RESULTS The expression of miR-328-3p was significantly upregulated after 18β-GRA intervention in AGS cells(P=4.51E-06).Overexpression of miR-328-3p inhibited GC cell proliferation and colony formation ability,arrested the cell cycle in the G0/G1 phase,promoted cell apoptosis,and inhibited the growth of subcutaneous tumors in BALB/c nude mice(P<0.01).No obvious necrosis was observed in the tumor tissue in the negative control group(no drug intervention or lentivirus transfection)and vector group(the blank vector for lentivirus transfection),and more cells were loose and necrotic in the miR-328-3p group.Bioinformatics tools predicted that miR-328-3p has a targeting relationship with STAT3,and STAT3 was closely related to autophagy markers such as p62.After overexpressing miR-328-3p,the expression level of STAT3 mRNA was significantly decreased(P<0.01)and p-STAT3 was downregulated(P<0.05).The dual-luciferase reporter gene assay showed that the luciferase activity of miR-328-3p and STAT33’untranslated regions of the wild-type reporter vector group was significantly decreased(P<0.001).Overexpressed miR-328-3p combined with bafilomycin A1(Baf A1)was used to detect the expression of LC3 II.Compared with the vector group,the expression level of LC3 II in the overexpressed miR-328-3p group was downregulated(P<0.05),and compared with the Baf A1 group,the expression level of LC3 II in the overexpressed miR-328-3p+Baf A1 group was upregulated(P<0.01).The expression of LC3 II was detected after intervention of 18β-GRA in GC cells,and the results were consistent with the results of miR-328-3p overexpression(P<0.05).Additional studies showed that 18β-GRA promoted autophagy flow by promoting autophagosome synthesis(P<0.001).qPCR showed that the expression of STAT3 mRNA was downregulated after drug intervention(P<0.05).Western blot analysis showed that the expression levels of STAT3 and p-STAT3 were significantly downregulated after drug intervention(P<0.05).CONCLUSION 18β-GRA promotes the synthesis of autophagosomes and inhibits GC cell proliferation by regulating the miR-328-3p/STAT3 signaling pathway.
基金Project supported by the National Natural Science Foundation of China and Zhong GuanCun Analytical Center.
文摘α-Eleostearic acid and β-eleostearic acid formed vesicles in aqueous medium when an ethanol solution of eleostearic acid was injected rapidly into a vigorously vortexed aqueous phase. Formation of the vesicles was demonstrated by electron microscopic observation and bromothymol blue encapsulation experiments. Polymerizations of the eleostearic acids in the formed vesicles carried out by UV irradiation produced poly-α-eleostearic acid and poly-β-eleostearic acid vesicles.
文摘Activated carbons calcined at 400˚C and 600˚C (AC-400 and AC-600), prepared using palm nuts, collected in the town of Franceville in Gabon, were used to study the dynamic adsorption of MnO<sub>4</sub>-</sup> ions in acidic media on fixed bed column and on the kinetic modeling of experimental data of breakthrough curves of MnO<sub>4</sub>-</sup> ions obtained. Results on the adsorption of MnO<sub>4</sub>-</sup> ions in fixed-bed dynamics obtained on AC-400 and AC-600 adsorbents beds indicated that the AC-400 bed appears to be the most efficient in removing MnO<sub>4</sub>-</sup> ions in acidic media. Indeed, the adsorbed amounts, the adsorbed capacities at saturation and the elimination percentage of MnO<sub>4</sub>-</sup> ions obtained with AC-400 (31.24 mg;52.06 mg·g<sup>-1</sup> and 41.65% respectively) were higher compared to those obtained with AC-600 (9.87 mg;16.45 mg·g<sup>-1</sup> and 17.79% respectively). The breakthrough curves kinetic modeling revealed that the Thomas model and the pseudo-first-order kinetic model were the most suitable models to describe the adsorption of MnO<sub>4</sub>-</sup> ions on adsorbents studied in our experimental conditions. The results of the intraparticle diffusion model showed that intraparticle diffusion was involved in the adsorption mechanism of MnO<sub>4</sub>-</sup> ions on investigated adsorbents and was not the limiting step and the only process controlling MnO<sub>4</sub>-</sup> ions adsorption. In contrast to AC-400, the intraparticle diffusion on AC-600 bed plays an important role in the adsorption mechanism of MnO<sub>4</sub>-</sup> ions.
基金supported by the National Natural Science Foundation of China(31972267 and 3227253)the Chinese Universities Scientific Fund(2023TC109)。
文摘Aphids are major insect pests in agriculture and forestry worldwide.Following attacks by natural enemies,many aphids release an alarm pheromone to protect their population.In most aphids,the main component of the aphid alarm pheromone(AAP)is the sesquiterpene hydrocarbon(E)-β-farnesene(EβF).However,the mechanisms behind its biosynthesis and regulation remain poorly understood.In this study,we used the bird cherry–oat aphid Rhopalosiphum padi,which is an important wheat aphid,to investigate the regulatory mechanisms of EβF biosynthesis.Our results showed that EβF biosynthesis occurs during the mature embryo period and the molting period of the 1st-and 2nd-instar nymphs.Triglycerides provide the prerequisite material for EβF production and release.Based on transcriptome sequencing,RNAi analysis,hormone treatments,and quantitative measurements,we found that the biosynthesis of EβF utilizes acetyl coenzyme A produced from fatty acid degradation,which can be suppressed by juvenile hormone but it is promoted by 20-hydroxyecdysone through the modulation of fatty acid metabolism.This is the first systemic study on the modulation of EβF production in aphids.The results of our study provide insights into the molecular regulatory mechanisms of AAP biosynthesis,as well as valuable information for designing potential aphid control strategies.
基金National Natural Science Foundation of China(22075112)Jiangsu Province and Education Ministry Co-Sponsored Synergistic Innovation Center of Modern Agricultural Equipment(XTCX2027)Jiangsu Province Innovation Support Program International Science and Technology Cooperation Project(BZ2022045)。
文摘Photoelectrochemical NO_(3)^(-)reduction(PEC NITRR)not only provides a promising solution for promoting the global nitrogen cycle,but also converts NO_(3)^(-)to the important chemicals(NH_(3)).However,it is still a great challenge to prepare catalysts with excellent NO_(3)^(-)adsorption/activation capacity to achieve high NITRR.Herein,we designed a novel Fe^(2+)~Cu^(2+)Fe^(3+)LDH/BiVO_(4)(FCF-LDH/BVO)catalyst with synergistic effect of chemical adsorption and physical enrichment.Fe^(2+)in FCF-LDH/BVO provides the rich Lewis acid sites for the adsorption of NO_(3)^(-),and the appropriate layer spacing of FCF-LDH further promotes the physical enrichment of NO_(3)^(-)in its interior,thus realizing the effective contact between NO_(3)^(-)and active sites(Fe^(2+)).FCF-LDH/BVO showed excellent NH_(3)production performance(FE_(NH_(3))=66.1%,r_(NH_(3))=13.8μg h^(-1)cm^(-2))and selectivity(FE_(NO_(2)^(-))=2.5%,r_(NO_(2)^(-))=4.9μg h^(-1)cm^(-2))in 0.5 mol L^(-1)Na_(2)SO_(4)electrolyte.In addition,FCF-LDH/BVO maintains the desirable PEC stability for six cycle experiments,showing great potential for practical application.The^(14)NO_(3)^(-)and^(15)NO_(3)^(-)isotope test provides strong evidence for further verification of the origin of N in the generated NH_(3).This LDH catalyst has a great potential in PEC removal of NO_(3)^(-)from groundwater.
文摘The different resistance of cotton (Gossypium hirsutum L.) cultivars to crude toxin of Verticillium dah/iae(VD) was correlated with the activities of chitinase and β-1, 3-glucanase in callus cells. The activities of chitinase and β-1, 3-glucanase in the callus cells treated with the VD-toxin were increased to the higher level at earlier time point in resistant cultivars than these in the susceptible cultivars. Exogenous salicylic acid (SA) induced the accumulation of chitinase and β -1,3-glucanase, which resulted in the resistance of callus cells to the VD. toxin. Western blot using a polyclonal antibody against β -1,3-glucanase identified 28 kD protein that was induced by VD-toxin, SA, or VD-toxin plus SA.
基金Supported by the National Natural Science Foundation of China,No.81570468 and No.81741056Jinshan Science and Technology Commission,No.2014-3-07
文摘BACKGROUND Disorders of primary bile acid synthesis may be life-threatening if undiagnosed,or not treated with primary bile acid replacement therapy. To date, there are few reports on the management and follow-up of patients with Δ4-3-oxosteroid 5β-reductase(AKR1 D1) deficiency. We hypothesized that a retrospective analysis of the responses to oral bile acid replacement therapy with chenodeoxycholic acid(CDCA) in patients with this bile acid synthesis disorder will increase our understanding of the disease progression and permit evaluation of this treatment regimen as an alternative to the Food and Drug Administration(FDA) approved drug cholic acid, which is currently unavailable in China.AIM To evaluate the therapeutic responses of patients with AKR1 D1 deficiency to oral bile acid therapy, specifically CDCA.METHODS Twelve patients with AKR1 D1 deficiency, confirmed by fast atom bombardment ionization-mass spectrometry analysis of urine and by gene sequencing for mutations in AKR1 D1, were treated with differing doses of CDCA or ursodeoxycholic acid(UDCA). The clinical and biochemical responses to therapy were monitored over a period ranging 0.5-6.4 years. Dose adjustment, to optimize the therapeutic dose, was based on changes in serum biochemistry parameters,notably liver function tests, and suppression of the urinary levels of atypical hepatotoxic 3-oxo-Δ4-bile acids measured by mass spectrometry.RESULTS Physical examination, serum biochemistry parameters, and sonographic findings improved in all 12 patients during bile acid therapy, except one who underwent liver transplantation. Urine bile acid analysis confirmed a significant reduction in atypical hepatotoxic 3-oxo-Δ4 bile acids concomitant with clinical and biochemical improvements in those patients treated with CDCA. UDCA was ineffective in down-regulating endogenous bile acid synthesis as evidenced from the inability to suppress the urinary excretion of atypical 3-oxo-Δ4-bile acids. The dose of CDCA required for optimal clinical and biochemical responses varied from 5.5-10 mg/kg per day among patients based on maximum suppression of the atypical bile acids and improvement in serum biochemistry parameters, and careful titration of the dose was necessary to avoid side effects from CDCA.CONCLUSION The primary bile acid CDCA is effective in treating AKR1 D1 deficiency but the therapeutic dose requires individualized optimization. UDCA is not recommended for long-term management.
文摘By using acetonitrile as the sole nitrogen source, a microbial strain with high nitrilase activity, named as Alcaligenes sp. ECU0401, was newly isolated from soil, which could enantioselectively transform racemic mandelonitrile into (R)-(?)-mandelic acid, with an enantiomeric excess of >99.9%.
基金Supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China (20103514110002)the Science and Technology Key Project of Fujian Province (2009N0046)
文摘A bacterium strain B26 capable of producing(R)-α-hydroxyphenylacetic acid [(R)-HPA](yield,47.5%;enantiomeric excess,99.1%) from phenylglyoxylic acid(PGA) with high optical purity was isolated and identified as Bacillus sp.B26 by 16S rDNA(ribosomal DNA) sequencing.Phylogenic analysis showed that the strain was most similar to Bacillus sp.enrichment culture clone SYW5(FJ601635.1) and Bacillus cereus strain FM-4(EU794727.1).Efforts were made to further improve HPA-production and PGA-tolerance by UV irradiation and UV-LiCl cooperative mutagenesis.Among viable mutants,B.sp.UV-38 and B.sp.ULi-11 exhibited better productivities than the wild type.Comparisons of HPA production and time course among wild strain and two mutants showed that B.sp.ULi-11 was more competent than B.sp.UV-38.HPA production was increased by 39.1% with B.sp.ULi-11(yield,65.4%) compared to that with B.sp.B26(yield,47.0%) when cultured in fermentation broth(pH 7.2) at 32℃ with an agitation speed of 180 r·min-1 and PGA final concentration of 15 mmol·L-1 for 25 h.
基金supported by the National Transgenic Breeding Project, China (2008ZX08010-004)the National Natural Science Foundation of China (30830080)+1 种基金the National Basic Research Program of China (G2006CB102105, 2009CB941604)the National High Technology Research and Development Program of China (20060110Z1039, 2008AA10Z143)
文摘Polyunsaturated fatty acids (PUFAs) are essential for normal growth in mammals, especially the ω-3 PUFAs, which play important roles in preventing several life-threatening diseases, such as coronary heart disease and diabetes. In this study, we aimed to investigate whether the sFat-1 gene from Caenorhabditis briggsae could be functionally expressed in transgenic pigs, and whether the transgenic could synthesize high quality ω-3 PUFAs endogenously. In this study, a gene construct consisting of CMV promoter and 1.9 kb cDNA of ω-3 fatty acid desaturase gene (sFat-1) from C. briggsae was injected into the male pronucleus of pig embryos by microinjection. The piglets were screened for the transgene by PCR, Southern blot and reverse transcription-PCR analysis. Pigs that give positive results were mated with wild-type pigs to produce the next generation and the transmission of transgene was examined by PCR analysis. Fatty acids compositions of various tissues in the transgenic pigs were then analyzed by gas chromatograph. A total of 878 embryos were transferred into 42 recipients, among which 29 successfully got pregnant and gave birth to a total of 162 piglets, and 8 of them were identified to be transgenic. Fatty acid compositions in the transgenic pigs were altered, and the levels of ω-6:ω-3 ratios were decreased from 14.53 in the control to 2.62 in Fat-1 transgenic pigs. A number of primary sFat-1-transgenic pigs were bred in this study, which lays the foundation for cultivation of new varieties of transgenic pigs.
文摘R2(4hydroxyphenoxy)propionic acid(RHPPA)is a key intermediate for the synthesis of classic herbicides with high selectivity against grassy weed.The main route for RHPPA biosynthesis is to hydroxylate the substrate R2phenoxypropionic acid(RPPA)at C4 position with microbes.In order to provide sufficient RPPA for the industrial production of RHPPA,an effective RPPA synthesis method was established and optimized in this work.The synthesis process mainly consisted of two steps:(1)synthesis of S2chloropropionic acid from Lalanine via diazotization and chlorination reactions;and(2)synthesis of RPPA from S2chloropropionic acid and phenol via etherification reaction.The optimal reaction conditions were as follows:HCl:NaNO_(2):KI:LAla=2.0:1.2:0.7:1.0(in molar),125℃reflux for 1.5 h,with KI as catalyst,and KI:S2chloropropionic acid:phenol=0.075:1.2:1.0(in molar).Under these conditions,an improved molar conversion rate(74.9%,calculated in phenol)was achieved.After extraction using anionic exchange resin Amberlite IRA400(CI),RPPA product with a purity of 95.08%was obtained.The purified RPPA was identified and evaluated in the application of the biotransformative production of RHPPA.The results indicated that the synthesized RPPA supported the RHPPA biosynthesis with a comparable yield as that of the standard RPPA.The RPPA synthesis method provided herein exhibited the advantages of low price and easy availability of raw materials,less toxicity of reagents,simple manipulations,and low equipment/instrument requirements.
基金Supported by the Natural Science Foundation of Fujian Province (No.E0310019) and Key Project of Science and Technology of Fujian Province (No.2003H023).
文摘The kinetics of asymmetric production of R-(-)-mandelic acid (R-MA) from phenylglyoxylic acid (PGA) catalyzed by Saccharomyces cerevisiae sp. strain FD11b was studied by fed-batch cultures. The concentrations of glucose and PGA were controlled respectively with a dual feeding system. When the electron donor glucose was supplied at the rate of 0.0833mmol·gdw^-1·h^-1, the specific production rate (qp) and the enantiomeric excess of R-MA reached the maximum 0.353mmol·gdw^-1·h^-1 and 97.1%, respectively. The apparent reduction activity of yeast FD 11 b was obviously affected by both substrate PGA and product MA. The qp value reached the maximum 0.36-0.38mmol·gdw^-1·h^-1 when the PGA concentration was controlled between 25 and 35mmol·L^-1. The obvious substrate inhibition of bioconversion was observed at the PGA concentrations higher than 40mmol·L^-1. The accumulation of product MA also caused a severe feed-back inhibition for its production when the product concentration was above 60mmol·L^-1. The kinetic model with the inhibition effect of both substrate and product was simulated by a computer-based least-square arithrnatic. The established kinetic model was in good agreement with the experimental data.
基金supported by the Youth Shihezi University Applied Basic Research Project of China,No.2015ZRKYQ-LH19
文摘Estrogen affects the generation and transmission of neuropathic pain,but the specific regulatory mechanism is still unclear.Activation of the N-methyl-D-aspartate acid receptor 1(NMDAR1) plays an important role in the production and maintenance of hyperalgesia and allodynia.The present study was conducted to determine whether a relationship exists between estrogen and NMDAR1 in peripheral nerve pain.A chronic sciatic nerve constriction injury model of chronic neuropathic pain was established in rats.These rats were then subcutaneously injected with 17β-estradiol,the NMDAR1 antagonist D(-)-2-amino-5-phosphonopentanoic acid(AP-5),or both once daily for 15 days.Compared with injured drug na?ve rats,rats with chronic sciatic nerve injury that were administered estradiol showed a lower paw withdrawal mechanical threshold and a shorter paw withdrawal thermal latency,indicating increased sensitivity to mechanical and thermal pain.Estrogen administration was also associated with increased expression of NMDAR1 immunoreactivity(as assessed by immunohistochemistry) and protein(as determined by western blot assay) in spinal dorsal root ganglia.This 17β-estradiol-induced increase in NMDAR1 expression was blocked by co-administration with AP-5,whereas AP-5 alone did not affect NMDAR1 expression.These results suggest that 17β-estradiol administration significantly reduced mechanical and thermal pain thresholds in rats with chronic constriction of the sciatic nerve,and that the mechanism for this increased sensitivity may be related to the upregulation of NMDAR1 expression in dorsal root ganglia.
基金This work was supported by the National Natural Science Foundation of China (No.21172210).
文摘We herein report two crystals based on 2-(imidazo[1,2-a]pyridin-2-yl)-2-oxoacetic acid rad- ical and its perchlorate, and investigate the relationship between magnetic properties and crystal stacking structures or supramolecular interactions. 2-(imidazo[1,2-a]pyridin-2-yl)- 2-oxoaeetic acid radical in two crystals mainly exist as diamagnetic dimer formed via short atomic contacts or supramolecular interactions (hydrogen bonds, anion-Tr or lone- pair-~r interactions), leading to low magnetic susceptibilities. 2-(imidazo[1,2-a]pyridin-2-yl)- 2-oxoaeetic acid radical crystal exhibits quasi-one-dimensional columnar stacking chain and weak antiferromagnetism. However, its perchlorate crystal possesses one-dimensional double- stranded chain structure assembled through double hydrogen bonds and anion-To interactions, and reveals weak ferromagnetism.
文摘AIM: To assess the value of long-chain w-3 fatty acids (FAs) supplementation in addition to amino-salicylic-acid (5-ASA) in pediatric patients with Crohn's disease (CD). METHODS: Thirty-eight patients (20 males and 18 females, mean age 10.13 years, range 5-16 years) with CD in remission were randomized into two groups and treated for 12 too. Group Ⅰ (18 patients) received 5-ASA (50 mg/kg/d)+w-3 FAs as triglycerides in gastroresistant capsules, 3 g/d (eicosapentanoic acid, EPA, 400 mg/g, docosahexaenoic acid, DHA, 200 mg/g). Group Ⅱ (20 patients) received 5-ASA (50 mg/kg/d)+olive oil placebo capsules. Patients were evaluated for fatty acid incorporation in red blood cell membranes by gas chromatography at baseline 6 and 12 mo after the treatment. RESULTS: The number of patients who relapsed at 1 year was significantly lower in group I than in group Ⅱ (P〈0.001). Patients in group I had a significant increase in the incorporation of EPA and DHA (P〈0.001) and a decrease in the presence of arachidonic acids. CONCLUSION: Enteric-coated w-3 FAs in addition to treatment with 5-ASA are effective in maintaining remission of pediatric CD.
基金Supported by Jinling Hospital Research Fund,No.2013064
文摘AIM To determine the effects of ω-3 fatty acids(ω-3FA) on the toll-like receptor 4(TLR4)/nuclear factor κB p56(NF-κBp56) signal pathway in the lungs of rats with severe acute pancreatitis(SAP).METHODS A total of 56 Sprague-Dawley rats were randomly divided into 4 groups: control group, SAP-saline group, SAP-soybean oil group and SAP-ω-3FA group. SAP was induced by the retrograde infusion of sodium taurocholate into the pancreatic duct. The expression of TLR4 and NF-κBp56 in the lungs was evaluated by immunohistochemistry and Western blot analysis. The levels of inflammatory cytokines interleukin-6 and tumor necrosis factor-alpha in the lungs were measured by enzyme-linked immunosorbent assay. RESULTS The expression of TLR4 and NF-κBp56 in lungs and of inflammatory cytokines in serum significantly increased in the SAP group compared with the control group(P < 0.05), but was significantly decreased in the ω-3FA group compared with the soybean oil group at 12 and 24 h(P < 0.05).CONCLUSION During the initial stage of SAP, ω-3FA can efficiently lower the inflammatory response and reduce lung injury by triggering the TLR4/NF-κBp56 signal pathway.