Induction of type III-deiodinase activity in astroglial cells by retinoids
| Autor: | Michel Pierre, Françoise Courtin, Stanislav Pavelka, Ana-Maria Lennon, Claire Gagelin, Ali Esfandiari, Jean-Michel Gavaret |
|---|---|
| Rok vydání: | 1994 |
| Předmět: |
medicine.medical_specialty
Thyroid Hormones Deiodinase Retinoic acid Fluorescent Antibody Technique Nerve Tissue Proteins Fibroblast growth factor Iodide Peroxidase Rats Sprague-Dawley 03 medical and health sciences Cellular and Molecular Neuroscience chemistry.chemical_compound Retinoids 0302 clinical medicine Internal medicine Glial Fibrillary Acidic Protein medicine Cyclic AMP Animals Cells Cultured 030304 developmental biology 0303 health sciences biology Retinol Brain Immunohistochemistry Rats Chemically defined medium Endocrinology medicine.anatomical_structure Neurology chemistry Astrocytes Enzyme Induction biology.protein Neuroglia Fibroblast Growth Factor 1 Tetradecanoylphorbol Acetate 030217 neurology & neurosurgery Astrocyte Hormone |
| Zdroj: | Glia. 11(3) |
| ISSN: | 0894-1491 |
| Popis: | Thyroid hormones and retinoic acid (RA) are important modulators of growth, development, and differentiation. Type III deiodinase (D-III), which catalyzes thyroid hormones degradation in the brain and in cultured astroglial cells, is induced in astroglial cells by multiple pathways, including cAMP, 12.0-tetradecanoylphorbol-13-acetate (TPA), fibroblast growth factors, and thyroid hormones themselves. In the present study, the effects of retinoids on D-III activity were examined in astroglial cells cultures in a chemically defined medium devoid of hormones and growth factors. Incubation of astroglial cells with 5 μM all-trans-RA caused up to 200-fold increase in D-III activity, which reached a plateau after 48 h. The retinoid-induced increase in D-III activity was concentration dependent (0.5 μM all-trans-RA and 9-cis-RA producing half-maximal effect). Retinol was effective at physiological concentrations (1 and μM). The 48 h effects of 5 μM all-trans-RA and 10 nM thyroid hormones on D-III activity were at least additive. Addition of 2 nM acidic fibroblast growth factor or 1 mM 8-bromo-cAMP for the last 8 h of a 48 h incubation with 5 μM all-trans-RA did not alter the induction by all-trans-RA, whereas 0.1 μM TPA in the same conditions produced an additive effect with all-trans-RA. All-trans-RA (5 μM) had little or no effect on type II deiodinase, the enzyme which catalyzes the activation of thyroxine to 3,5,3′-triiodothyronine. The potent action of retinoids on the enzyme responsible for thyroid hormones degradation in the brain may protect the brain from the effects of 3,5,3′-triiodothyronine in regions influenced by retinoids. © 1994 Wiley-Liss, Inc. |
| Databáze: | OpenAIRE |
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