Search results for "Downregulation and upregulation"
showing 10 items of 459 documents
Moderate exercise is an antioxidant: Upregulation of antioxidant genes by training
2006
Exercise causes oxidative stress only when exhaustive. Strenuous exercise causes oxidation of glutathione, release of cytosolic enzymes, and other signs of cell damage. However, there is increasing evidence that reactive oxygen species (ROS) not only are toxic but also play an important role in cell signaling and in the regulation of gene expression. Xanthine oxidase is involved in the generation of superoxide associated with exhaustive exercise. Allopurinol (an inhibitor of this enzyme) prevents muscle damage after exhaustive exercise, but also modifies cell signaling pathways associated with both moderate and exhaustive exercise in rats and humans. In gastrocnemius muscle from rats, exerc…
PTEN Mediates the Antioxidant Effect of Resveratrol at Nutritionally Relevant Concentrations
2014
Introduction.Antioxidant properties of resveratrol have been intensively studied for the last years, bothin vivoandin vitro. Its bioavailability after an oral dose is very low and therefore it is very important to make sure that plasma concentrations of free resveratrol are sufficient enough to be active as antioxidant.Aims.In the present study, using nutritionally relevant concentrations of resveratrol, we aim to confirm its antioxidant capacity on reducing peroxide levels and look for the molecular pathway involved in this antioxidant effect.Methods.We used mammary gland tumor cells (MCF-7), which were pretreated with different concentrations of resveratrol for 48 h, and/or a PTEN inhibit…
Interfering with Arginine Metabolism As a New Treatment Strategy for Multiple Myeloma
2015
Abstract Introduction Starvation of tumor cells from the amino acid arginine has recently gained particular interest because of the downregulation of the rate-limiting enzyme argininosuccinate synthethase 1 (ASS1) in various cancer entities. ASS1-deficient cells cannot resynthesize arginine from citrulline and are therefore considered arginine auxotrophic. The arginine depleting enzyme arginine deiminase (ADI-PEG20, Polaris Pharmaceuticals) is currently tested in phase I-III clinical trials for different arginine auxotrophic cancers. The natural arginine analogue canavanine can compete with arginine for arginyl-tRNA-binding sites and consequently be incorporated into nascent proteins instea…
Downregulation of a Chitin Deacetylase-Like Protein in Response to Baculovirus Infection and Its Application for Improving Baculovirus Infectivity
2009
ABSTRACT Several expressed sequence tags (ESTs) with homology to chitin deacetylase-like protein (CDA) were selected from a group of Helicoverpa armigera genes whose expression changed after infection with H. armigera single nucleopolyhedrovirus (HearNPV). Some of these ESTs coded for a midgut protein containing a chitin deacetylase domain (CDAD). The expressed protein, HaCDA5a, did not show chitin deacetylase activity, but it showed a strong affinity for binding to chitin. Sequence analysis showed the lack of any chitin binding domain, described for all currently known peritrophic membrane (PM) proteins. HaCDA5a has previously been detected in the H. armigera PM. Such localization, togethe…
Heme oxygenase-1 induction by nitric oxide in RAW 264.7 macrophages is upregulated by a cyclo-oxygenase-2 inhibitor.
2001
Unstimulated RAW 264.7 macrophages express negligible heme oxygenase-1 (HO-1) protein but incubation with the nitric oxide (NO) donor spermine nonoate (SPNO) induced HO-1 and weakly cyclo-oxygenase-2 (COX-2) protein. This effect was potentiated by coincubation with the COX-2 selective inhibitor, SC58125. Cells incubated with SPNO showed a strong increase in HO-1 mRNA levels after 4 h with a significant potentiation in the presence of SC58125, which did not modify HO-1 mRNA stability. The induction of HO-1 by NO and its potentiation by anti-inflammatory agents may play a role in inflammatory and immune responses.
Differential expression of the corticosteroid receptors GR1, GR2 and MR in rainbow trout organs with slow release cortisol implants
2012
The present study describes the transcriptional levels of the corticosteroid receptors (CRs) GR1, GR2 and MR in the different organs of the rainbow trout (Oncorhynchus mykiss) in response to a slow release of cortisol, throughout a 10-day period. We show that after short term (1 day after cortisol implantation), when the plasma levels of cortisol emulate an acute stress, the GR2 and MR expression levels were upregulated in the brain and head kidney tissues. This result reflects the role of these organs as regulators of the stress response. In general, the rest of the organs, especially gills, intestine, liver, muscle and spleen, showed decreased transcriptional levels of GR1, GR2 and MR, al…
Early adaptive response of the retina to a pro-diabetogenic diet: Impairment of cone response and gene expression changes in high-fructose fed rats
2015
The lack of plasticity of neurons to respond to dietary changes, such as high fat and high fructose diets, by modulating gene and protein expression has been associated with functional and behavioral impairments that can have detrimental consequences. The inhibition of high fat-induced rewiring of hypothalamic neurons induced obesity. Feeding rodents with high fructose is a recognized and widely used model to trigger obesity and metabolic syndrome. However the adaptive response of the retina to short term feeding with high fructose is poorly documented. We therefore aimed to characterize both the functional and gene expression changes in the neurosensory retina of Brown Norway rats fed duri…
Peroxisome Proliferator-Activated Receptor Deficiency Increases the Risk of Maternal Abortion and Neonatal Mortality in Murine Pregnancy with or with…
2006
We assessed the implication of peroxisome proliferator-activated receptor (PPAR) alpha deficiency in pregnancy outcome and neonatal survival and in the modulation of T cell differentiation in murine diabetic pregnancy and their offspring. Pregnant wild-type (WT) and PPAR alpha-null mice of C57BL/6J genetic background were rendered diabetic by five low doses of streptozotocin. We observed that, in the absence of diabetes, PPAR alpha deficiency resulted in an increase in abortion rate, i.e. 0% in WT mice vs. 20% in PPAR alpha-null mice [odds ratio (OR) = 14.33; P = 0.013]. Under diabetic conditions, the abortion rate was enhanced, i.e. 8.3% in WT mice vs. 50% in PPAR alpha-null mice (OR = 4.2…
Differentiative pathway activated by 3-aminobenzamide, an inhibitor of PARP, in human osteosarcoma MG-63 cells
2004
AbstractThis study describes the molecular mechanism by which treatment with 3-AB, a potent inhibitor of PARP, allows human osteosarcoma MG-63 cells to restrict growth and enter differentiation. Our findings show that in MG-63 cells, aberrant gene expression keeps Rb protein constitutively inactivated through hyperphosphorylation and this promotes uncontrolled proliferation of the cells. After 3-AB-treatment, the poly(ADP-ribosyl)ation of nuclear proteins markedly decreases and this results in an increase in both the hypophosphorylated active form of Rb and pRb/E2F complexes. These effects are accompanied by G1 arrest, downregulation of gene products required for proliferation (cyclin D1, β…
The down-regulation of miR-125b in chronic lymphocytic leukemias leads to metabolic adaptation of cells to a transformed state
2012
AbstractMiR-125b-1 maps at 11q24, a chromosomal region close to the epicenter of 11q23 deletions in chronic lymphocytic leukemias (CLLs). Our results establish that both aggressive and indolent CLL patients show reduced expression of miR-125b. Overexpression of miR-125b in CLL-derived cell lines resulted in the repression of many transcripts encoding enzymes implicated in cell metabolism. Metabolomics analyses showed that miR-125b overexpression modulated glucose, glutathione, lipid, and glycerolipid metabolism. Changes on the same metabolic pathways also were observed in CLLs. We furthermore analyzed the expression of some of miR-125b–target transcripts that are potentially involved in the…