Search results for "Enhancer"
showing 10 items of 148 documents
Sequential Hepatogenic Transdifferentiation of Adipose Tissue-Derived Stem Cells: Relevance of Different Extracellular Signaling Molecules, Transcrip…
2009
Adipose tissue contains a mesenchymal stein cell (MSC) population Known as adipose-derived stein cells (ASCs) capable of differentiating into different cell types. Our aim was to induce hepatic transdifferentiation of ASCs by sequential exposure to several combinations of cytokines, growth factors, and hormones. The most efficient hepatogenic protocol includes fibroblastic growth factors (FGF) 2 and 4 and epidermal growth factor (EGF) (step 1), hepatocyte growth factor (HGF), FGF2, FGF4, and nicotinamide (Nic) (step 2), and oncostatin M (OSM), dexamethasone (Dex), and insulin-tranferrin-selenium (step 3). This protocol activated transcription factors [GATA6, Hex, CCAAT/enhancer binding prot…
The carbon monoxide-releasing molecule CORM-2 inhibits the inflammatory response induced by cytokines in Caco-2 cells
2007
Background and purpose: Recent evidence indicates that carbon monoxide-releasing molecules (CO-RMs) exhibit potential anti-inflammatory properties. In the present study, we have investigated whether tricarbonyl dichloro ruthenium(II) dimer (CORM-2) can control the inflammatory response induced by cytokines in a human colonic epithelial cell line, Caco-2. Experimental approach: Caco-2 cells were preincubated with CORM-2 for 30 minutes and then stimulated with interleukin (IL)-1β, tumor necrosis factor-α and interferon-γ for different times. Gene expression was analyzed by real-time PCR. Protein expression was investigated by Western blot and ELISA. Transcription factor activation was determi…
321. Sea Urchin sns Chromatin Insulator Prevents Silencing and Positional Effect Variegation of Oncoretroviral Vectors Transgene Expression in Murine…
2006
Silencing and position effect are considered significant obstacles to obtain a consistent level of transgene expression in viral gene therapy. Furthermore recent studies had shown that retroviruses tend to land on active genes with the potential consequence of insertional mutagenesis. The inclusion of elements, such as chromatin insulators, capable to insulate a gene from the surrounding chromatin effects at the integration site should improve both efficacy and safety of gene therapy vectors. We have previously characterized a 265 bp insulator element, termed sns, localized at the 3’ end of the early histone H2A gene of the sea urchin Paracentrotus lividus. This sequence contains three cis-…
MICELLE POLIMERICHE A BASE DI NUOVI DERIVATI ANFIFILICI DELL’INULINA PER LA SOMMINISTRAZIONE OCULARE TOPICA DI CORTICOSTEROIDI NEL TRATTAMENTO DELLE …
2016
Al giorno d’oggi, la via di somministrazione oftalmica costituisce ancora una sfida per i tecnologi farmaceutici. Si tratta, inoltre, probabilmente di uno degli ambiti che più di ogni altro potrebbe beneficiare dello sviluppo di nuovi Drug Delivery Systems basati sull’utilizzo di nanovettori. Infatti, più del 50% delle patologie oculari maggiormente debilitanti (es. degenerazione maculare legata all’età, retinopatia diabetica ed edema maculare diabetico) ha origine a livello del segmento oculare posteriore. Ad oggi, la terapia intravitreale costituisce il gold standard per garantire il raggiungimento del sito target, ovvero la retina. Tuttavia, la necessità di ricorrere a frequenti somminis…
Comparative enhancer effects of Span20 with Tween20 and Azone on the in vitro percutaneous penetration of compounds with different lipophilicities.
2000
Sorbitan monolaurate (Span20) was used in this study to analyze the influence of the polar functional group on the effects that non-ionic surfactants have on skin permeability. Its ethoxylate derivative polysorbate 20 (Tween20) and Azone, both with the same C12 alkyl chain as Span20, were used for comparative purposes. We evaluated the relative potency of the three molecules as enhancers in the permeability of a series of compounds with lipophilicities ranging from log Poct=-0.95 to log Poct=2.33. The influence of the enhancer concentration was also studied. For this purpose the epidermis of Wistar rat was pretreated with ethanolic solutions (1 and 5%, w/v) of each enhancer. Our results ind…
Hepatic farnesyl diphosphate synthase expression is suppressed by polyunsaturated fatty acids
2005
Dietary vegetable oils and fish oils rich in PUFA (polyunsaturated fatty acids) exert hypocholesterolaemic and hypotriglyceridaemic effects in rodents. The plasma cholesterol-lowering properties of PUFA are due partly to a diminution of cholesterol synthesis and of the activity of the rate-limiting enzyme HMG-CoA reductase (3-hydroxy-3-methylglutaryl-CoA reductase). To better understand the mechanisms involved, we examined how tuna fish oil and individual n−3 and n−6 PUFA affect the expression of hepatic FPP synthase (farnesyl diphosphate synthase), a SREBP (sterol regulatory element-binding protein) target enzyme that is subject to negative-feedback regulation by sterols, in co-ordination …
2015
Transporters of the ATP-binding cassette (ABC) family such as MDR1 play a pivotal role in persistence of brain homeostasis by contributing to the strict permeability properties of the blood–brain barrier. This barrier on one hand compromises treatment of central nervous system diseases by restricting access of drugs; on the other hand, an impaired or altered function of barrier building cells has been described in neurological disorders. The latter might contribute to increased vulnerability of the brain under pathological conditions or even enforce pathogenesis. Here, we present a novel approach for a systematic examination of drug impact on Mdr1 gene expression by establishing a dual repo…
Enhancer, chromatin insulator, non-coding RNA and α-histone gene expression during embryogenesis of the sea urchin Paracentrotus lividus.
2009
Core promoters and chromatin insulators (ins) may direct a transcriptional enhancer (enh) to prefer a specific promoter in complex genetic loci. Enh and ins flank the sea urchin Paracentrotus lividus α-histone H2A transcription unit in a tandem repeated cluster containing the five histone genes. In vivo competition assays of enh and ins functions reveal that the H2A enh-bound MBF-1 activator participates also in the expression of the H3 gene and that the sns5 ins buffers the downstream H1 promoter from the H2A enh. These results suggest that both the H2A enh and the sns5 ins may account for the diverse accumulation of the linker vs core nucleosomal histones during early development of the s…
The sea urchin histone H2A enhancer-binding protein MBF-1 is needed for maximal expression also for the H3 gene, while is buffered by the sns5 insula…
2009
Enhancers are DNA elements which increase the transcription of associated gene in a position and distance independent manner relative to the transcription initiation site. Molecular mechanisms must operate to direct enhancers to specific promoters in complex genetic loci. The sea urchin a-histone genes are organized in several hundred tandem repeated units, each containing one copy of the five histone genes in the order 5’-H4-H2B-H3-H2A-H1-3’. Transcription is limited to the early cleavage and reaches its maximum at morula stage. After hatching these genes are repressed and maintained in the silenced state for whole life cycle of the animal. In Paracentrotus lividus, the MBF-1 activator bin…