12 research outputs found
Osmoadaptation cellulaire cérébrale en situation d'hypertonicité systémique chez le rat (expession des gènes osmoprotecteurs et de leur facteur de transcription transactivateur)
No full textLes observations cliniques suggèrent que les cellules du cerveau possèdent une capacité d'osmoadaptation. Dans un modèle animal d'hypertonicité systémique, nous avons étudié, au niveau du cerveau par immunocytochimie et hybridation in situ, l'expression cellulaire des gènes osmoprotecteurs aldose réductase (AR) et transporteur du myo-inositol (SMIT) et celle de leur facteur de transcription transactivateur (TonEBP). L'expression osmo-induite de TonEBP est restreinte aux neurones, celle de AR et de SMIT à certaines sous-populations respectivement neuronales et non-neuronales. Cette divergence d'expression cellulaire suggère l'implication d'autres gènes. Par biopuce, nous avons identifié quatre gènes précoces codant des facteurs de transcription et un transporteur des acides aminés neutres dont l'expression est osmo-induite dans le tissu cérébral et qui sont potentiellement impliqués dans l'osmoadaptation celluaire cérébraleClinical observations suggest that brain cells possess osmoadaptation ability. Using an animal model of systemic hypertonicity, we have studied by immunocytochemistry and in situ hybridization cellular expression of osmoprotective genes, aldose reductase (AR) and myo-inositol transporter (SMIT) and their transactivator transcription factor (TonEBP). TonEBP is expressed and tonicity-induced in neurons only. Tonicity-induced expression of AR and SMIT is restricted to respectively some neuronal and non-neuronal cell subsets. These large discrepancies in cellular expression suggest the involvement of other genes. Using microarray analysis, we have identified four immediate early genes encoding transcription factors and one neutral aminoacid transporter whose tissular expression is tonicity-induced in brain and which might be involved in brain cellular osmoadaptationLYON1-BU.Sciences (692662101) / SudocSudocFranceF
Gene Expression of Taurine Transporter and Taurine Biosynthetic Enzymes in Hyperosmotic States
No full textLack of Glucocorticoids Enhances the Early Activation of the Medullary Catecholaminergic Cell Groups Triggered by Restraint Stress
No full textPhylogenesis of Brain Glutamic Acid Decarboxylase from Vertebrates: Immunochemical Studies
No full textTaurine Biosynthesis in Rat Brain In Vivo: Lack of Relationship with Cysteine Sulfinate Decarboxylase Glutamate Decarboxylase‐Associated Activity (GAD/CSDII)
No full textCysteine Sulfinate Decarboxylase in Brain: Identification, Characterization and Immunocytochemical Location in Astrocytes
No full textCysteine Sulfinate Decarboxylase (CSD): Molecular Cloning, Sequence and Genomic Expression in Brain
No full textRegional Expression and Histological Localization of Cysteine Sulfinate Decarboxylase mRNA in the Rat Kidney<sup>1</sup>
No full text Cysteine sulfinate decarboxylase (CSD) is the rate-limiting biosynthetic enzyme of the pathway that forms taurine, a putative osmolyte in the kidney, which was previously localized in various segments of the nephron. Although CSD is known to be expressed in whole kidney extracts, no information on CSD mRNA regional expression and histological localization is yet available. Western blotting and Northern blotting were performed in four dissected regions of the kidney using an antiserum against recombinant CSD and a [32P]-dCTP-labeled CSD cDNA probe, respectively. In situ hybridization was carried out using a [35S]-CTP-labeled CSD RNA probe. A single protein (53 kD) and a single mRNA (2.5 kb) were detected, both of which appeared to be most enriched in the outer stripe of the outer medulla. In situ hybridization of CSD mRNA showed strong labeling of the thick tubules in the outer stripe of the outer medulla and in cortical medullary rays that corresponded to the proximal straight tubules. The significance of this restricted expression of CSD is discussed in relationship to the data previously reported on the location of taurine and the location of the taurine transporter along the nephron. </jats:p
Gene expression profiling in brain following acute systemic hypertonicity: novel genes possibly involved in osmoadaptation
No full textGene expression profiling in brain following acute systemic hypertonicity: novel genes possibly involved in osmoadaptation
No full textIn brain osmoprotective genes known to be involved in cellular osmoadaptation to hypertonicity, as well as the related transcription factor tonicity-responsive enhancer binding protein (TonEBP) are only expressed in some cell subsets. In the search for other genes possibly involved in osmoadaptation of brain cells we have analyzed, through microarray, the transcriptional profile of forebrain from rats subjected to 45 min, 90 min, and 6 h systemic hypertonicity. Microarray data were validated by quantitative real-time PCR. Around 23 000 genes gave a reliable hybridization signal. The number of genes showing a higher expression increased from around 15 (45 min) up to nearly 200 (6 h). Among about 30 immediate early genes (IEGs) encoding transcription factors, only Atf3, Verge, and Klf4 showed a rapid increased expression. TonEBP-mRNA tissue level and TonEBP-mRNA labeling in neurons remained unchanged whereas TonEBP labeling was rapidly increased in neurons. Sodium-dependent neutral amino acid transporter-2 (SNAT2) encoded by gene Slc38a2 showed a delayed increased expression. The rapid tonicity-induced activation of Atf3, Verge, and Klf4 may regulate genes involved in osmoadaptation. Nfat5 encoding TonEBP is not an IEG and the early tonicity-induced expression of TonEBP in neurons may result from translational activation. Increased expression of sodium-dependent neutral amino-acid transporter 2 may lead to the cellular accumulation of amino acids for adaptation to hypertonicity.close91
