Search results for "Gene expression"
showing 10 items of 4085 documents
Comparison of global responses to mild deficiency and excess copper levels in Arabidopsis seedlings
2013
[EN] Copper is an essential micronutrient in higher plants, but it is toxic in excess. The fine adjustments required to fit copper nutritional demands for optimal growth are illustrated by the diverse, severe symptoms resulting from copper deficiency and excess. Here, a differential transcriptomic analysis was done between Arabidopsis thaliana plants suffering from mild copper deficiency and those with a slight copper excess. The effects on the genes encoding cuproproteins or copper homeostasis factors were included in a CuAt database, which was organised to collect additional information and connections to other databases. The categories overrepresented under copper deficiency and copper e…
Biological activities of Schottenol and Spinasterol, two natural phytosterols present in argan oil and in cactus pear seed oil, on murine miroglial B…
2014
International audience; The objective of this study was to evaluate the biological activities of the major phytosterols present in argan oil (AO) and in cactus seed oil (CSO) in BV2 microglial cells. Accordingly, we first determined the sterol composition of AO and CSO, showing the presence of Schottenol and Spinasterol as major sterols in AO. While in CSO, in addition to these two sterols, we found mainly another sterol, the Sitosterol. The chemical synthesis of Schottenol and Spinasterol was performed. Our results showed that these two phytosterols, as well as sterol extracts from AO or CSO, are not toxic to microglial BV2 cells. However, treatments by these phytosterols impact the mitoch…
Polyamines Impair Immunity to Helicobacter pylori by Inhibiting L-Arginine Uptake Required for Nitric Oxide Production
2010
International audience; BACKGROUND & AIMS: Helicobacter pylori-induced immune responses fail to eradicate the bacterium. Nitric oxide (NO) can kill H pylori. However, translation of inducible NO synthase (iNOS) and NO generation by H pylori-stimulated macrophages is inhibited by the polyamine spermine derived from ornithine decarboxylase (ODC), and is dependent on availability of the iNOS substrate L-arginine (L-Arg). We determined if spermine inhibits iNOS-mediated immunity by reducing L-Arg uptake into macrophages. METHODS: Levels of the inducible cationic amino acid transporter (CAT) 2, ODC, and iNOS were measured in macrophages and H pylori gastritis tissues. L-Arg uptake, iNOS expressi…
Oxidative stress response of tumor cells: microarray-based comparison between artemisinins and anthracyclines
2004
The antimalarial artemisinins also reveal profound cytotoxic activity against tumor cells. Artemisinins harbor an endoperoxide bridge whose cleavage results in the generation of reactive oxygen species (ROS) and/or artemisinin carbon-centered free radicals. Established cancer drugs such as anthracyclines also form ROS and free radicals that are responsible for the cardiotoxicity of anthracyclines. In contrast, artemisinins do not reveal cardiotoxicity. In the present investigation, we compared the cytotoxic activities of different artemisinins (artemisinin, artesunate, arteether, artemether, artemisitene, dihydroartemisinylester stereoisomers) in 60 cell lines of the National Cancer Institu…
Enhancement of cytotoxicity of artemisinins toward cancer cells by ferrous iron
2004
Abstract Iron(II) heme-mediated activation of the peroxide bond of artemisinins is thought to generate the radical oxygen species responsible for their antimalarial activity. We analyzed the role of ferrous iron in the cytotoxicity of artemisinins toward tumor cells. Iron(II)–glycine sulfate (Ferrosanol) and transferrin increased the cytotoxicity of free artesunate, artesunate microencapsulated in maltosyl-β-cyclodextrin, and artemisinin toward CCRF-CEM leukemia and U373 astrocytoma cells 1.5- to 10.3-fold compared with that of artemisinins applied without iron. Growth inhibition by artesunate and ferrous iron correlated with induction of apoptosis. Cell cycle perturbations by artesunate an…
Atherogenic properties of enzymatically degraded LDL: selective induction of MCP-1 and cytotoxic effects on human macrophages.
1998
Abstract —The mechanisms underlying the selective accumulation of macrophages in early atherosclerotic lesions are poorly understood but are likely to be related to specific properties of altered low density lipoprotein (LDL) deposited in the subendothelium. Enzymatic, nonoxidative degradation of LDL converts the lipoprotein to a potentially atherogenic moiety, enzymatically altered LDL (E-LDL), which activates complement and is rapidly taken up by human macrophages via a scavenger receptor–dependent pathway. Immunohistological evidence indicates that E-LDL is present in an extracellular location in the early lesion. We report that E-LDL causes massive release of monocyte chemotactic prote…
The anti-inflammatory fungal compound (S)-curvularin reduces proinflammatory gene expression in an in vivo model of rheumatoid arthritis.
2012
In previous studies, we identified the fungal macrocyclic lactone (S)-curvularin (SC) as an anti-inflammatory agent using a screening system detecting inhibitors of the Janus kinase/signal transducer and activator of transcription pathway. The objective of the present study was to investigate whether SC is able to decrease proinflammatory gene expression in an in vivo model of a chronic inflammatory disease. Therefore, the effects of SC and dexamethasone were compared in the model of collagen-induced arthritis (CIA) in mice. Total genomic microarray analyses were performed to identify SC target genes. In addition, in human C28/I2 chondrocytes and MonoMac6 monocytes, the effect of SC on proi…
JAK3/STAT5/6 Pathway Alterations Are Associated with Immune Deviation in CD8+ T Cells in Renal Cell Carcinoma Patients
2010
To investigate the molecular mechanisms underlying altered T cell response in renal cell carcinoma (RCC) patients, we compared autologous and allogeneic CD8(+) T cell responses against RCC line from RCC patients and their HLA-matched donors, using mixed lymphocyte/tumor cell cultures (MLTCs). In addition, we analyzed the expression of molecules associated with cell cycle regulation. Autologous MLTC responder CD8(+) T cells showed cytotoxic activity against RCC cell lines; however the analysis of the distribution of CD8(+) T-cell subsets revealed that allogenic counterparts mediate superior antitumor efficacy. In RCC patients, a decreased proliferative response to tumor, associated with defe…
The Peroxisomal 3-keto-acyl-CoA thiolase B Gene Expression Is under the Dual Control of PPARα and HNF4α in the Liver
2011
PPARα and HNF4α are nuclear receptors that control gene transcription by direct binding to specific nucleotide sequences. Using transgenic mice deficient for either PPARα or HNF4α, we show that the expression of the peroxisomal3-keto-acyl-CoA thiolase B(Thb) is under the dependence of these two transcription factors. Transactivation and gel shift experiments identified a novel PPAR response element within intron 3 of theThbgene, by which PPARα but not HNF4α transactivates. Intriguingly, we found that HNF4α enhanced PPARα/RXRα transactivation from TB PPRE3 in a DNA-binding independent manner. Coimmunoprecipitation assays supported the hypothesis that HNF4α was physically interacting with RXR…
Heat Stress Induces Extended Plateau of Hsp70 Accumulation - A Possible Cytoprotection Mechanism in Hepatic Cells
2015
The relevance of heat preconditioning resides in its ability to protect cells from different kinds of injury by induction of heat shock proteins, a process in which the intensity of heat stress (HS) and duration of subsequent recovery are vital. This study evaluates the effects of moderate HS (45 min/43°C) and the time-dependent changes during recovery period of HSP70, Bcl-2 and p53 gene and protein expression in HepG2 cells. We also evaluated the effects of 0.4 mM aspirin (ASA) as a potential pharmacological co-inducer of HSP, both alone and in a combination with HS (ASA + HS). HS alone and ASA + HS caused a major up-regulation of HSP70 mRNA in the first 2 h, while HSP70 protein increased …