RESUMO
BACKGROUND: Acute myocardial infarction (AMI) is the myocardial avascular necrosis syndrome caused by coronary atherosclerotic plaque rupture, thrombosis or coronary artery occlusion. Therefore, it is of great significance to find new targets for the treatment of myocardial infarction. The purpose of this study was to investigate the effect of microRNA-379 (miR-379) on AMI and its mechanism. METHODS: MiR-379 mimic was used to transfect H9c2 cells and we determined the protective effect of miR-379 on H9c2 by detecting the level of apoptosis. TargetScan software was used to detect miR-379's downstream targets. We constructed siRNA to analyze the effect of miR-379's downstream targets on H9c2 cells. In addition, we used miR-379 agomir to inject the tail vein of AMI rats to verify the effect of miR-379 on rat cardiomyocytes. RESULTS: TargetScan detected that miR-379 and Tumor necrosis factor-α-induced protein 8 (TNFAIP8) may have binding sites and the dual luciferase reporter assay found that miR-379 binds to TNFAIP8 and inhibits its activity. MiR-379 mimic was found to reduce the expression of caspase3 and caspase9 in H9c2 cells and thereby reduce H
Assuntos
Proteínas Reguladoras de Apoptose , MicroRNAs , Infarto do Miocárdio , Animais , Apoptose , Proteínas Reguladoras de Apoptose/metabolismo , MicroRNAs/metabolismo , Infarto do Miocárdio/genética , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , RatosRESUMO
Poly-γ-glutamic acid (γ-PGA) is a natural, biodegradable and water-soluble biopolymer of glutamic acid. This review is focused on nonrecombinant microbial production of γ-PGA via fermentation processes. In view of its commercial importance, the emphasis is on L-glutamic acid independent producers (i.e. microorganisms that do not require feeding with the relatively expensive amino acid L-glutamic acid to produce γ-PGA), but glutamic acid dependent production is discussed for comparison. Strategies for improving production, reducing costs and using renewable feedstocks are discussed.
Assuntos
Ácido Poliglutâmico/análogos & derivados , Bacillus/metabolismo , Biopolímeros/metabolismo , Meios de Cultura , Fermentação , Microbiologia de Alimentos , Ácido Glutâmico/metabolismo , Ácido Poliglutâmico/química , Ácido Poliglutâmico/metabolismoRESUMO
Ubiquitination can significantly affect the endocytosis and degradation of plasma membrane proteins. Here, the ubiquitination of a Saccharomyces cerevisiae urea plasma membrane transporter (Dur3p) was altered. Two potential ubiquitination sites, lysine residues K556 and K571, of Dur3p were predicted and replaced by arginine, and the effects of these mutations on urea utilization and formation under different nitrogen conditions were investigated. Compared with Dur3p, the Dur3pK556R mutant showed a 20.1% decrease in ubiquitination level in yeast nitrogen base medium containing urea and glutamine. It also exhibited a >75.8% decrease in urea formation in yeast extract-peptone-dextrose medium and 41.3 and 55.4% decreases in urea and ethyl carbamate formation (a known carcinogen), respectively, in a model rice wine system. The results presented here show that the mutation of Dur3p ubiquitination sites could significantly affect urea utilization and formation. Modifying the ubiquitination of specific transporters might have promising applications in rationally engineering S. cerevisiae strains to efficiently use specific nitrogen sources.
Assuntos
Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Oryza/microbiologia , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Ureia/metabolismo , Uretana/metabolismo , Vinho/microbiologia , Motivos de Aminoácidos , Fermentação , Glutamina/metabolismo , Proteínas de Membrana Transportadoras/química , Oryza/metabolismo , Oxirredução , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/química , Ubiquitinação , Vinho/análiseRESUMO
Bacillus licheniformis TISTR 1010 was used for glutamic acid-independent production of poly-γ-glutamic acid (γ-PGA). A fed-batch production strategy was developed involving feedings of glucose, citric acid, and ammonium chloride at specified stages of the fermentation. With the dissolved oxygen concentration controlled at ≥50% of air saturation and the pH controlled at ~7.4, the fed-batch operation at 37 °C afforded a peak γ-PGA concentration of 39.9 ± 0.3 g L-1 with a productivity of 0.926 ± 0.006 g L-1 h-1. The observed productivity was nearly threefold greater than previously reported for glutamic acid-independent production using the strain TISTR 1010. The molecular weight of γ-PGA was in the approximate range of 60 to 135 kDa.
Assuntos
Bacillus licheniformis/crescimento & desenvolvimento , Meios de Cultura/química , Ácido Poliglutâmico/biossíntese , Concentração de Íons de HidrogênioRESUMO
In previous work, three evolved Propionibacterium acidipropionici mutants with higher tolerant capacity of propionic acid (PA) were obtained by genome shuffling. Here, we attempted to unravel the acid-tolerant mechanism of P. acidipropionici by comparing the physiological changes between P. acidipropionici and three mutants. The parameters used for comparison included intracellular pH (pHi), NADâº/NADH ratio, Hâº-ATPase activity, and the intracellular amino acids concentrations. It was indicated that the acid tolerance of P. acidipropionici was systematically regulated. Specifically, low pHi promoted the P. acidipropionici to biosynthesize more Hâº-ATPase to pump the protons out of the cells, and as a result, the NADâº/NADH ratio increased due to the decreased protons concentration. The increased arginine, aspartic acid, and glutamic acid concentrations helped to resist the acidic environment by consuming more H⺠and generating more ATP and NH3. Based on what was analyzed above, 20 mM arginine and aspartic acid were added during the shaker culture of P. acidipropionici, and the maximal PA titer reached 14.38 g/L, which was increased by 39.9% compared with the control.
Assuntos
Propionatos/farmacologia , Propionibacterium/metabolismo , Aminoácidos/metabolismo , Concentração de Íons de Hidrogênio , Mutação , NAD/metabolismo , Propionibacterium/efeitos dos fármacos , Propionibacterium/genética , ATPases Translocadoras de Prótons/metabolismo , Estresse FisiológicoRESUMO
Streptomyces transglutaminase (TGase) has been widely used in food, pharmaceutical and textile industries. Streptomyces TGase is naturally synthesized as zymogen (pro-TGase), which is then processed to produce active enzyme by removing its N-terminal pro-peptide. Although the pro-peptide is essential for TGase folding and secretion, few studies have been reported on improving the properties of TGase by pro-peptide engineering. In this study, we developed a new approach to improve the properties of TGase based on pro-peptide engineering. When the α-helix(37G-42S) in pro-peptide was substituted with three glycines and three alanines respectively, the mutants exhibited higher specific activity and the efficiency of pro-peptide cleavage was enhanced. To further improve the properties of TGase, relevant mutations were constructed by introducing linker peptides in the C-terminus of the pro-peptide. Mutants with GS (GGGGS) and PT (PTPPTTPT) linker peptide exhibited 1.28 fold and 1.5 fold higher specific activity than the wild-type enzyme, respectively. This new method could be used to improve the properties of TGase by pro-peptide modification, which is a promising technology for creating unique TGase with various beneficial properties.
Assuntos
Precursores Enzimáticos/química , Peptídeos/química , Streptomyces/enzimologia , Transglutaminases/química , Transglutaminases/metabolismo , Precursores Enzimáticos/genética , Precursores Enzimáticos/metabolismo , Mutação , Peptídeos/metabolismo , Estrutura Secundária de Proteína , Homologia Estrutural de Proteína , Transglutaminases/genéticaRESUMO
Adenosine tri-phosphate (ATP), the most important energy source for metabolic reactions and pathways, plays a vital role in the growth of industrial strain and the production of target metabolites. In this review, current advances in manipulating ATP in industrial strains, including altering NADH availability, and regulating NADH oxidation pathway, oxygen supply, proton gradient, the electron transfer chain activity and the F(0)F(1)-ATPase activity, are summarized and discussed. By applying these strategies, optimal product concentrations, yields and productivity in industrial biotechnology have been achieved. Furthermore, the mechanisms by which ATP extends the substrate utilization spectra and enhances the ability to challenge harsh environmental stress have been elucidated. Finally, three critical issues related to ATP manipulation have been addressed.
Assuntos
Trifosfato de Adenosina/metabolismo , Biotecnologia/métodos , Bactérias/metabolismoRESUMO
A series of amino acid ester prodrugs of the dual VEGFR-2/FGFR-1 kinase inhibitor 1 (BMS-540215) was prepared in an effort to improve the aqueous solubility and oral bioavailability of the parent compound. These prodrugs were evaluated for their ability to liberate parent drug 1 in in vitro and in vivo systems. The l-alanine prodrug 8 (also known as brivanib alaninate/BMS-582664) was selected as a development candidate and is presently in phase II clinical trials.
Assuntos
Carcinoma/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Pró-Fármacos/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Pirróis/farmacologia , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/antagonistas & inibidores , Triazinas/farmacologia , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Administração Oral , Alanina/análogos & derivados , Animais , Disponibilidade Biológica , Proliferação de Células/efeitos dos fármacos , Ensaios Clínicos Fase II como Assunto , Desenho de Fármacos , Avaliação Pré-Clínica de Medicamentos , Humanos , Intestinos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Camundongos , Microssomos/efeitos dos fármacos , Estrutura Molecular , Pró-Fármacos/síntese química , Pró-Fármacos/química , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Pirróis/síntese química , Pirróis/química , Solubilidade , Estereoisomerismo , Triazinas/síntese química , Triazinas/química , Água/química , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The ethanol-water extract of A. deliciosa root (EEAD) was fractionated into n-hexane (EEAD-He), ethyl acetate (EEAD-Ea), n-butanol (EEAD-Bu) and aqueous (EEAD-Aq) fractions according to their different polarity and solubility. Among the four extracts, it was found that EEAD-Bu was enriched with oleanolic acid (OLA). The antioxidant and hepatoprotective activities of various EEAD fractions and OLA were carefully investigated by the methods of ferric thiocyanate (FTC) and thiobarbituric acid (TBA), as well as the model of CCL4-induced liver toxicity in rats. The results showed that the EEAD-Bu had higher in vitro antioxidant and in vivo hepatoprotective activities than those of the other types of extracts (p< 0.05). When the CCL4-induced rats were treatment with 120 mg/kg EEAD-Bu, the activities of alanine transaminase (ALT) and aspartate transanimase (AST) in rat serum decreased 90 % and 81 %, respectively, as compared with those of the CCL4 control rats. Furthermore, the lipid peroxidation (MDA) decreased 42 % and glutathione (GSH) increased 114 % in the rats liver homogenate, as compared with those of the control. The results also indicated that the hepatoprotective activity of the EEAD-Bu (at the dose of 120 mg/kg) was higher than that of the reference drug silymarin (at the dose of 60 mg/kg), and OLA acted as an important role in dose-dependent protection against CCL4 hepatotoxicity. The findings indicate that the OLA-enriched EEAD-Bu extract had significant and concentration dependent hepatoprotective effect for the carbon tetrachloride induced rat liver injury.