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1.
Polyphenols from green tea prevent antineuritogenic action of Nogo‐A via 67‐kDa laminin receptor and hydrogen peroxide 下载免费PDF全文
Usha Gundimeda Thomas H. McNeill Barsegh A. Barseghian William S. Tzeng David V. Rayudu Enrique Cadenas Rayudu Gopalakrishna 《Journal of neurochemistry》2015,132(1):70-84
Axonal regeneration after injury to the CNS is hampered by myelin‐derived inhibitors, such as Nogo‐A. Natural products, such as green tea, which are neuroprotective and safe for long‐term therapy, would complement ongoing various pharmacological approaches. In this study, using nerve growth factor‐differentiated neuronal‐like Neuroscreen‐1 cells, we show that extremely low concentrations of unfractionated green tea polyphenol mixture (GTPP) and its active ingredient, epigallocatechin‐3‐gallate (EGCG), prevent both the neurite outgrowth‐inhibiting activity and growth cone‐collapsing activity of Nogo‐66 (C‐terminal domain of Nogo‐A). Furthermore, a synergistic interaction was observed among GTPP constituents. This preventive effect was dependent on 67‐kDa laminin receptor (67LR) to which EGCG binds with high affinity. The antioxidants N‐acetylcysteine and cell‐permeable catalase abolished this preventive effect of GTPP and EGCG, suggesting the involvement of sublethal levels of H2O2 in this process. Accordingly, exogenous sublethal concentrations of H2O2, added as a bolus dose (5 μM) or more effectively through a steady‐state generation (1–2 μM), mimicked GTPP in counteracting the action of Nogo‐66. Exogenous H2O2 mediated this action by bypassing the requirement of 67LR. Taken together, these results show for the first time that GTPP and EGCG, acting through 67LR and elevating intracellular sublethal levels of H2O2, inhibit the antineuritogenic action of Nogo‐A.
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Selective method for identification and quantification of Bifidobacterium animalis subspecies lactis BB‐12 (BB‐12) from the gastrointestinal tract of healthy volunteers ingesting a combination probiotic of BB‐12 and Lactobacillus rhamnosus GG 下载免费PDF全文
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Gastón E. Ortiz María C. Ponce-Mora Diego G. Noseda Gabriela Cazabat Celina Saravalli María C. López Guillermo P. Gil Martín Blasco Edgardo O. Albertó 《Journal of industrial microbiology & biotechnology》2017,44(2):197-211
The application of pectinases in industrial olive-oil processes is restricted by its production cost. Consequently, new fungal strains able to produce higher pectinase titers are required. The aim of this work was to study the capability of Aspergillus giganteus NRRL10 to produce pectinolytic enzymes by SSF and evaluate the application of these in olive-oil extraction. A. giganteus was selected among 12 strains on the basis of high pectinolytic activity and stability. A mixture composed by wheat bran, orange, and lemon peels was selected as the best substrate for enzyme production. Statistical analyses of the experimental design indicated that pH, temperature, and CaCl2 are the main factors that affect the production. Subsequently, different aeration flows were tested in a tray reactor; the highest activity was achieved at 20 L min?1 per kilogram of dry substrate (kgds). Finally, the pectinolytic enzymes from A. giganteus improved the oil yield and rheological characteristics without affecting oil chemical properties. 相似文献
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Milagros C. Romay Nam Che Scott N. Becker Delila Pouldar Raffi Hagopian Xinshu Xiao Aldons J. Lusis Judith A. Berliner Mete Civelek 《Journal of lipid research》2015,56(1):38-50
Exposure of endothelial cells (ECs) to agents such as oxidized glycerophospholipids (oxGPs) and cytokines, known to accumulate in atherosclerotic lesions, perturbs the expression of hundreds of genes in ECs involved in inflammatory and other biological processes. We hypothesized that microRNAs (miRNAs) are involved in regulating the inflammatory response in human aortic endothelial cells (HAECs) in response to oxGPs and interleukin 1β (IL-1β). Using next-generation sequencing and RT-quantitative PCR, we characterized the profile of expressed miRNAs in HAECs pre- and postexposure to oxGPs. Using this data, we identified miR-21-3p and miR-27a-5p to be induced 3- to 4-fold in response to oxGP and IL-1β treatment compared with control treatment. Transient overexpression of miR-21-3p and miR-27a-5p resulted in the downregulation of 1,253 genes with 922 genes overlapping between the two miRNAs. Gene Ontology functional enrichment analysis predicted that the two miRNAs were involved in the regulation of nuclear factor κB (NF-κB) signaling. Overexpression of these two miRNAs leads to changes in p65 nuclear translocation. Using 3′ untranslated region luciferase assay, we identified 20 genes within the NF-κB signaling cascade as putative targets of miRs-21-3p and -27a-5p, implicating these two miRNAs as modulators of NF-κB signaling in ECs. 相似文献
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C. Lawrence Kien Dwight E. Matthews Matthew E. Poynter Janice Y. Bunn Naomi K. Fukagawa Karen I. Crain David B. Ebenstein Emily K. Tarleton Robert D. Stevens Timothy R. Koves Deborah M. Muoio 《Journal of lipid research》2015,56(9):1795-1807
Palmitic acid (PA) is associated with higher blood concentrations of medium-chain acylcarnitines (MCACs), and we hypothesized that PA may inhibit progression of FA β-oxidation. Using a cross-over design, 17 adults were fed high PA (HPA) and low PA/high oleic acid (HOA) diets, each for 3 weeks. The [1-13C]PA and [13-13C]PA tracers were administered with food in random order with each diet, and we assessed PA oxidation (PA OX) and serum AC concentration to determine whether a higher PA intake promoted incomplete PA OX. Dietary PA was completely oxidized during the HOA diet, but only about 40% was oxidized during the HPA diet. The [13-13C]PA/[1-13C]PA ratio of PA OX had an approximate value of 1.0 for either diet, but the ratio of the serum concentrations of MCACs to long-chain ACs (LCACs) was significantly higher during the HPA diet. Thus, direct measurement of PA OX did not confirm that the HPA diet caused incomplete PA OX, despite the modest, but statistically significant, increase in the ratio of MCACs to LCACs in blood. 相似文献
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James M. May Ashwath Jayagopal Zhi-chao Qu William H. Parker 《Biochemical and biophysical research communications》2014
High glucose concentrations due to diabetes increase apoptosis of vascular pericytes, impairing vascular regulation and weakening vessels, especially in brain and retina. We sought to determine whether vitamin C, or ascorbic acid, could prevent such high glucose-induced increases in pericyte apoptosis. Culture of human microvascular brain pericytes at 25 mM compared to 5 mM glucose increased apoptosis measured as the appearance of cleaved caspase 3. Loading the cells with ascorbate during culture decreased apoptosis, both at 5 and 25 mM glucose. High glucose-induced apoptosis was due largely to activation of the receptor for advanced glycation end products (RAGE), since it was prevented by specific RAGE inhibition. Culture of pericytes for 24 h with RAGE agonists also increased apoptosis, which was completely prevented by inclusion of 100 μM ascorbate. Ascorbate also prevented RAGE agonist-induced apoptosis measured as annexin V binding in human retinal pericytes, a cell type with relevance to diabetic retinopathy. RAGE agonists decreased intracellular ascorbate and GSH in brain pericytes. Despite this evidence of increased oxidative stress, ascorbate prevention of RAGE-induced apoptosis was not mimicked by several antioxidants. These results show that ascorbate prevents pericyte apoptosis due RAGE activation. Although RAGE activation decreases intracellular ascorbate and GSH, the prevention of apoptosis by ascorbate may involve effects beyond its function as an antioxidant. 相似文献
10.
Marien J.C. Houtman Sanne M. Korte Yuan Ji Bart Kok Marc A. Vos Anna Stary-Weinzinger Marcel A.G. van der Heyden 《Biochemical and biophysical research communications》2014
Potassium inward rectifier KIR2.1 channels contribute to the stable resting membrane potential in a variety of muscle and neuronal cell-types. Mutations in the KIR2.1 gene KCNJ2 have been associated with human disease, such as cardiac arrhythmias and periodic paralysis. Crystal structure and homology modelling of KIR2.1 channels combined with functional current measurements provided valuable insights in mechanisms underlying channel function. KIR2.1 channels have been cloned and analyzed from all main vertebrate phyla, except reptilians. To address this lacuna, we set out to clone reptilian KIR2.1 channels. Using a degenerated primer set we cloned the KCNJ2 coding regions from muscle tissue of turtle, snake, bear, quail and bream, and compared their deduced amino acid sequences with those of KIR2.1 sequences from 26 different animal species obtained from Genbank. Furthermore, expression constructs were prepared for functional electrophysiological studies of ectopically expressed KIR2.1 ion channels. In general, KCNJ2 gene evolution followed normal phylogenetic patterns, however turtle KIR2.1 ion channel sequence is more homologues to avians than to snake. Alignment of all 31 KIR2.1 sequences showed that all disease causing KIR2.1 mutations, except V93I, V123G and N318S, are fully conserved. Homology models were built to provide structural insights into species specific amino acid substitutions. Snake KIR2.1 channels became expressed at the plasmamembrane and produced typical barium sensitive (IC50 ∼6 μM) inward rectifier currents. 相似文献