Search results for "Gene expression"
showing 10 items of 4085 documents
Phosphorylation of peroxisome proliferator-activated receptor α in rat Fao cells and stimulation by ciprofibrate
1999
The basic mechanism(s) by which peroxisome proliferators activate peroxisome proliferator-activated receptors (PPARs) is (are) not yet fully understood. Given the diversity of peroxisome proliferators, several hypotheses of activation have been proposed. Among them is the notion that peroxisome proliferators could activate PPARs by changing their phosphorylation status. In fact, it is well known that several members of the nuclear hormone receptor superfamily are regulated by phosphorylation. In this report, we show that the rat Fao hepatic-derived cell line, known to respond to peroxisome proliferators, exhibited a high content of PPARalpha. Alkaline phosphatase treatment of Fao cell lysat…
The analysis of modified peroxisome proliferator responsive elements of the peroxisomal bifunctional enzyme in transfected HepG2 cells reveals two re…
1995
AbstractPeroxisome proliferators (PPs) are non-genotoxic carcinogens in rodents. They can induce the expression of numerous genes via the heterodimerization of two members of the steroid hormone receptor superfamily, called the peroxisome proliferator-activated receptor (PPAR) and the 9-cis retinoic acid receptor (RXR). Many of the PP responsive genes possess a peroxisome proliferator response element (PPRE) formed by two TGACCT-related motifs. The bifunctional enzyme (HD) PPRE contains 3 such motifs, creating DR1 and DR2 sequences. PPAR and RXR regulate transcription via the DR1 element while DR2 modulates the expression of the gene via auxiliary factors in HepG2 cells.
Functional characterization of a peroxisome proliferator response-element located in the intron 3 of rat peroxisomal thiolase B gene.
2003
Expression of the rat peroxisomal 3-ketoacyl-CoA thiolase gene B is induced by peroxisome proliferators. Although a sequence element like a peroxisome proliferator-activated receptor (PPAR)-binding site is located in the promoter region of this gene, we previously found that this element is competent for the activation by hepatocyte nuclear factor-4, but not functional with PPARalpha. We describe here a new peroxisome proliferator-response element located in the intron 3 (+1422/+1434) that binds in vitro the PPARalpha/retinoid X receptor alpha heterodimer and confers the induction by PPARalpha in transfection assays. We propose a model of regulation of the rat thiolase B gene involving thos…
Controlled uptake of PFOA in adult specimens of Paracentrotus lividus and evaluation of gene expression in their gonads and embryos
2023
AbstractPerfluorooctanoic acid (PFOA) has been largely used in the manufacturing industry but a few years ago it turned out to be a dangerous pollutant which is now of concern for terrestrial and aquatic environments. Here, we investigated the bioaccumulation of PFOA in the sea urchin Paracentrotus lividus after exposure to different concentrations of the pollutant for 28 days. We observed rapid uptake of PFOA in the coelomic fluid collected weekly during the exposure period and high bioaccumulation in gonads at the end of the experiment. Interestingly, animals were also able to fast depurate when relocated to a clean environment. In addition, to assess the effect of PFOA on sea urchins’ ph…
Expression of membrane C1q in human monocyte-derived macrophages is developmentally regulated and enhanced by interferon-γ
2001
The present study investigated when during "in vitro" maturation macrophages (MPhi) express membrane C1q (mC1q), and whether cell activation affects expression and function of mC1q. Although C1q mRNA was repeatedly detected in freshly isolated monocytes using reverse transcriptase-polymerase chain reaction, C1q protein was observed only in developing MPhi from day 1 to 4 on using immunodetection and flow cytometry. However, the quantity of mC1q and other MPhi membrane proteins differed strikingly in cells from different donors. We report here for the first time that CD14(+) and CD14(-) mC1q-bearing MPhi can develop, and that interferon-gamma increases mC1q display at the cell surface, and m…
Synergy assessment of fixed combinations of Herba Andrographidis and Radix Eleutherococci extracts by transcriptome-wide microarray profiling
2015
Abstract Background Generally accepted, but insufficiently proved, the concept of synergy is based on an assumption that combining of two biologically active substances is justified because the combination is more active and less harmful than the ingredients. Hypothesis Analysis of RNA microarray of isolated neuroglia cells and the comparison the number of genes deregulated by plant extracts and their fixed herbal formulation might be a useful tool/method for assessment of synergistic and antagonistic interactions of herbal extracts in human organism. Aim The primary aim of this study was to extend a new method of assessment of synergistic and antagonistic interactions of herbal extracts in…
Effects of malvidin, cyanidin and delphinidin on human adipose mesenchymal stem cell differentiation into adipocytes, chondrocytes and osteocytes.
2019
Abstract Background Anthocyanidins are plant phytochemicals found at high concentrations in berries, vegetables and flowers. Anthocyanidins have been extensively investigated due to their antioxidative, antidiabetic and anti-inflammatory effects. Few studies show that anthocyanidins decrease obesity and improve bone density. However, the effects of anthocyanidins on tissue regeneration have not been sufficiently clarified. Human mesenchymal stem cells (MSCs) are multipotent adult stem cells responsible for the regeneration of fat, bone and cartilage. Although MSCs are often used for screening of biologically active compounds, so far, the effect of anthocyanidins on MSC differentiation has n…
Network Pharmacology of Red Ginseng (Part I): Effects of Ginsenoside Rg5 at Physiological and Sub-Physiological Concentrations
2021
Numerous in vitro studies on isolated cells have been conducted to uncover the molecular mechanisms of action of Panax ginseng Meyer root extracts and purified ginsenosides. However, the concentrations of ginsenosides and the extracts used in these studies were much higher than those detected in pharmacokinetic studies in humans and animals orally administered with ginseng preparations at therapeutic doses. Our study aimed to assess: (a) the effects of ginsenoside Rg5, the major “rare” ginsenoside of Red Ginseng, on gene expression in the murine neuronal cell line HT22 in a wide range of concentrations, from 10−4 to 10−18 M, and (b) the effects of differentially expressed genes on cellular …
Mechanism of action of Rhodiola, salidroside, tyrosol and triandrin in isolated neuroglial cells: An interactive pathway analysis of the downstream e…
2014
Abstract Aim The aim of this study was to identify the targets (genes, interactive signaling pathways, and molecular networks) of Rhodiola rosea extract in isolated neuroglia cells and to predict the effects of Rhodiola extract on cellular functions and diseases. In addition, the potential mechanism of action of Rhodiola rosea extract was elucidated, and the “active principle” among the three isolated constituents (salidroside, triandrin, and tyrosol) was identified. Methods Gene expression profiling was performed using the T98G human neuroglia cell line after treatment with the Rhodiola rosea SHR-5 extract and several of its individual constituents (salidroside, triandrin and tyrosol). An …
Long-term expression of the human alpha1-antitrypsin gene in mice employing anionic and cationic liposome vector.
1997
The complete process of gene therapy involves three important steps: targeting, delivery, and gene expression. Since each step can be related to the pharmacological concept of affinity, bioavailability, and intrinsic capacity, this commentary examines, from this perspective, the efficiency of anionic and cationic liposomes as vectors for the in vivo gene transfer of the human alpha1-antitrypsin gene. Small liposomes represent the first generation of liposomes destined for the liver parenchymal cell. Although the final efficiency of gene transfer is low, we found that small liposomes are a kind of high-affinity hepatocyte-destined vector because the dose range for mediating the response is t…