Search results for "REDUCTASE"
showing 10 items of 798 documents
Knockout of thep-Coumarate Decarboxylase Gene fromLactobacillus plantarumReveals the Existence of Two Other Inducible Enzymatic Activities Involved i…
2000
ABSTRACTLactobacillus plantarumNC8 contains apdcgene coding forp-coumaric acid decarboxylase activity (PDC). A food grade mutant, designated LPD1, in which the chromosomalpdcgene was replaced with the deletedpdcgene copy, was obtained by a two-step homologous recombination process using an unstable replicative vector. The LPD1 mutant strain remained able to weakly metabolizep-coumaric and ferulic acids into vinyl derivatives or into substituted phenyl propionic acids. We have shown thatL. plantarumhas a second acid phenol decarboxylase enzyme, better induced with ferulic acid than withp-coumaric acid, which also displays inducible acid phenol reductase activity that is mostly active when gl…
Regulation of the acetaldehyde concentration in culture medium during the fermentation of glucose by Saccharomyces cerevisiae
1970
Die Konzentration an Acetaldehyd im Medium wahrend der anaeroben Vergarung von Glucose durch Saccharomyces cerevisiae weist in der logarithmischen Wachstumsphase die hochsten Werte auf. Die Induktion der Pyruvatdecarboxylase durch Glucose fordert die Akkumulation von Acetaldehyd, der ins Medium diffundiert. Hefestamme, die unterschiedlich viel Acetaldehyd bilden, unterscheiden sich in ihren Pyruvatdecarboxylaseaktivitaten. Diese engen Beziehungen zwischen Pyruvatdecarboxylase und Acetaldehydproduktion deuten auf die Kontrollfunktion der Pyruvatdecarboxylase bei der Acetaldehydakkumulation hin. Hohere Aktivitaten der Alkoholdehydrogenase verringern die Acetaldehydakkumulation, wodurch sich e…
Re-expression of C/EBP alpha induces CYP2B6, CYP2C9 and CYP2D6 genes in HepG2 cells.
1998
Cytochrome P450 (CYP) activity is very low or even absent in human hepatomas, a phenomenon that is accompanied by low levels of some liver transcription factors, notably C/EBP alpha. To investigate a possible link between this transcription factor and hepatic CYP expression, we have stably transfected HepG2 cells with a C/EBP alpha vector containing a Zn-inducible metallothionein promoter. Expression of functional C/EBP alpha up to liver levels concomitantly increased the mRNAs of several members of the CYP2 family (2B6, 2C9 and 2D6), suggesting that this transcription factor may play a relevant role in controlling the hepatic expression of CYP enzymes.
Human HepG2 and rat Fao hepatic-derived cell lines show different responses to ciprofibrate, a peroxisome proliferator: analysis by flow cytometry.
1996
Abstract Peroxisome proliferators, and especially hypolipidemic drugs such as ciprofibrate, are known to be hepatocarcinogens in rodents, but their effect in humans is controversial. In an attempt to investigate the effects of ciprofibrate at a cellular level, the analysis of individual whole cells was performed by flow cytometry on samples from two hepatic-derived cell lines: the rat Fao cell line and the human HepG2 cell line. The increase of light scatter signals in rat Fao cells treated for 3 days with ciprofibrate at 250 μMwas related to modifications of intrinsic cellular parameters, such as size and cytoplasmic granularity. Conversely, no variations appeared in human HepG2-treated ce…
Stimulation of peroxisomal palmitoyl-CoA oxidase activity by ciprofibrate in hepatic cell lines: comparative studies in Fao, MH1C1 and HepG2 cells.
1993
The response of two rat cell lines, Fao and MH1C1, and one human cell line, HepG2, to the peroxisome proliferator ciprofibrate, was studied. Using a fluorometric assay for palmitoyl-CoA oxidase, the dose- and time-dependent increase of this enzymatic activity was determined. From the lowest concentration (100 microM) stimulation is evident in the two rat cell lines. In the Fao line, the activity was stimulated reaching a seven-fold increase over the control level at 250 microM after 72 h of treatment. In the MH1C1 line, the maximum stimulation, four- to five-fold, was obtained at 250 and 500 microM after 72 h. In the HepG2 cell line, activity increased two-fold at 250 microM after 72 h reac…
Carotid Atherosclerosis Evolution When Targeting a Low-Density Lipoprotein Cholesterol Concentration70 mg/dL After an Ischemic Stroke of Atherosclero…
2020
Background: The TST trial (Treat Stroke to Target) showed the benefit of targeting a low-density lipoprotein cholesterol (LDL-C) concentration of <70 mg/dL in terms of reducing the risk of major cardiovascular events in 2860 patients with ischemic stroke with atherosclerotic stenosis of cerebral vasculature. The impact on carotid atherosclerosis evolution is not known. Methods: TST-PLUS (Treat Stroke to Target–Plaque Ultrasound Study) included 201 patients assigned to an LDL-C concentration of <70 mg/dL and 212 patients assigned to a target of 100±10 mg/dL. To achieve these goals, investigators used the statin and dosage of their choice and added ezetimibe as needed. Ultrasonographer…
A Versatile and Convenient Method for the Functionalization of Porphyrins
2001
International audience; The condensation of 3-(chloromethyl)benzoyl chloride with different atropisomers of meso-(tetra-o-aminophenyl)porphyrin (TAPP), followed by the reaction of a series of nucleophilic reagents leads, among others, to precursors of biomimetic models of heme proteins such as cytochrome c oxidase (CcO). This synthesis can also be applied as an efficient two-step reaction to obtain highly functionalized porphyrin derivatives potentially useful for cation binding.
Genotoxicity of 1,4-benzoquinone and 1,4-naphthoquinone in relation to effects on glutathione and NAD(P)H levels in V79 cells.
1989
1,4-Benzoquinone is cytotoxic in V79 Chinese hamster cells and induces gene mutations and micronuclei. The cell-damaging effects of quinones are usually attributed to thiol depletion, oxidation of NAD(P)H, and redox-cycling involving the formation of semiquinone radicals and reactive oxygen species. To elucidate the role of these mechanisms in the genotoxicity of 1,4-benzoquinone, we measured various genotoxic effects, cytotoxicity, and the levels of glutathione, NADPH, NADH, and their oxidized forms all in the same experiment. 1,4-Naphthoquinone, which does not induce gene mutations in V79 cells, was investigated for comparative reasons. The quinones had a similar effect on the levels of c…
Oligodendrocyte Precursor Cells Synthesize Neuromodulatory Factors
2015
NG2 protein-expressing oligodendrocyte progenitor cells (OPC) are a persisting and major glial cell population in the adult mammalian brain. Direct synaptic innervation of OPC by neurons throughout the brain together with their ability to sense neuronal network activity raises the question of additional physiological roles of OPC, supplementary to generating myelinating oligodendrocytes. In this study we investigated whether OPC express neuromodulatory factors, typically synthesized by other CNS cell types. Our results show that OPC express two well-characterized neuromodulatory proteins: Prostaglandin D2 synthase (PTGDS) and neuronal Pentraxin 2 (Nptx2/Narp). Expression levels of the enzym…
High expression of QSOX1 reduces tumorogenesis, and is associated with a better outcome for breast cancer patients.
2012
International audience; ABSTRACT: INTRODUCTION: The gene quiescin/sulfhydryl oxidase 1, QSOX1, encodes an enzyme directed to the secretory pathway and excreted into the extracellular space. QSOX1 participates in the folding and stability of proteins and thus could regulate the biological activity of its substrates in the secretory pathway and/or outside the cell. The involvement of QSOX1 in oncogenesis has been studied primarily in terms of its differential expression in systemic studies. QSOX1 is overexpressed in prostate cancers and in pancreatic adenocarcinoma. In contrast, QSOX1 gene expression is repressed in endothelial tumors. In the present study, we investigated the role of QSOX1 i…